Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 2020-2023
  • 2000-2004
  • 1965-1969  (2,730)
  • 1950-1954
  • 1940-1944  (271)
  • 1920-1924  (480)
  • 1840-1849  (540)
  • 1830-1839
  • 1968  (1,339)
  • 1967  (1,391)
  • 1942  (271)
  • 1923  (248)
  • 1921  (232)
  • 1846  (540)
  • Organic Chemistry  (2,471)
  • Physics  (925)
  • Chemical Engineering  (569)
  • Cat  (23)
  • Insulin  (20)
  • Calcium  (14)
Source
Material
Years
  • 2020-2023
  • 2000-2004
  • 1965-1969  (2,730)
  • 1950-1954
  • 1940-1944  (271)
    • +
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Calcium binding by a lipid extract ofBacterionema matruchotii (1968)
    Springer
    Calcified tissue international 2 (1968), S. 296-298 
    Details
    ISSN: 1432-0827
    Keywords: Calcium ; Lipid ; Bacteria ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé On a fait ce travail pour determiner si le facteur responsable pour la liaison de calcium par un calcifableBacterionema matruchotii est dans la fraction lipide de la cellule. Des cellules congelees et sechees ont ete extraites par le chloroform-methanol. La fraction de chloroform-methanol, les cellules extraites et les cellules non traitees ont ete examinees pour la liaison de calcium. La fraction du chloroform-methanol et les cellules non traitees avaient la liaison de calcium. Les cellules extraites n'en avaient pas.
    Abstract: Zusammenfassung Diese Arbeit wurde durchgeführt um festzustellen, ob sich der Faktor für die Calcium-bindung, durch das calcifizierendeBacterionema matruchotii, in der Lipoidfraktion befindet. Die lyophiilisierten Zellen wurden mit Chloroform-Methanol extrahiert. Die Chloroform-Methanol-Fraktion, die extrahierten Zellen, sowie die nicht behandelten Zellen wurden auf eine Calciumbindung hin untersucht. Die Chloroform-Methanol-Fraktion und die nicht behandelten Zellen demonstrierten eine Calciumbindung. Die extrahierten Zellen hingegen nicht.
    Notes: Abstract This work was done to determine whether the factor responsible for calcium binding by a calcifiableBacterionema matruchotii is in the lipid fraction of the cell. Freeze-dried cells were extracted with chloroform-methanol. The chloroform-methanol fraction, the extracted cells and untreated cells were examined for calcium binding. The chloroform-methanol fraction and the untreated cells bound calcium. The extracted cells did not.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02279217
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Über die Glia marginalis und oberflächliche Nervenzellen im Hirnstamm der Katze (1968)
    Springer
    Anatomy and embryology 127 (1968), S. 221-231 
    Details
    ISSN: 1432-0568
    Keywords: Marginal glia ; Superficial nerve cells ; Brain stem ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Paraffinschnitten durch perfusionsfixierte Gehirne von erwachsenen Katzen werden in der Glia marginalis des Hirnstamms unterschiedlich gebaute Bezirke beschrieben. Es wird gezeigt, daß über dem Nucleus paragigantocellularis und über dem Ncl. “z” swischen den Fasern der Glia marginalis Nervenzellen liegen. Über dem erstgenannten Kern stellen diese Zellen möglicherweise das morphologische Substrat der chemosensiblen Felder dar, die durch die physiologischen Untersuchungen von Loeschcke, Mitchell u.a. bekannt geworden sind.
    Notes: Summary In the marginal glia covering the brain stem of the cat, regional differences are described in paraffin sections of brains which had been fixed by perfusion of Bouin's fluid. It is shown that between the glia fibres covering the nucleus paragigantocellularis and the nucleus “z” there are nerve cells. It is suggested that in the region of the nucleus paragiganto-cellularis these cells are the morphological substrate of a chemosensible zone described in physiological experiments by Loeschcke, Mitchell and others.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00526130
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Über die postnatale Zunahme des Capillarvolumens im Corpus callosum der Katze (1968)
    Springer
    Anatomy and embryology 127 (1968), S. 138-144 
    Details
    ISSN: 1432-0568
    Keywords: Capillary density ; Postnatal development ; Corpus callosum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Paraffinschnitten durch das Corpus callosum perfusionsfixierter Gehirne von 19 Katzen im Alter von einem Tag bis zu 2 1/2 Jahren wurde das Capillarvolumen bestimmt. Es beträgt bei der neugeborenen Katze 0,81 Vol.-%. In der 2. Lebenswoche beginnt eine Zunahme, die in der 5. Woche ein Maximum von 2,92 Vol.-% erreicht. Im Verlauf der 6. Woche setzt eine zunächst rasche, von der 7. Woche an aber nur noch langsam verlaufende Abnahme ein, bis bei einem Lebensalter von etwa 1 Jahr ein für das erwachsene Tier charakteristischer Wert um 1,5 Vol.-% erreicht wird. Die Abnahme des Capillarvolumens hängt mit der Markscheidenbildung und der dadurch bedingten Zunahme des Fasermaterials zusammen.
    Notes: Summary Postnatal changes of capillary density have been determined in paraffin sections through the corpus callosum of 19 cats. At birth the capillary density amounts to 0.81 vol.-%. In the 2nd week of postnatal life it begins to increase and reaches a maximum of 2.92 vol.-% in the 5th week. From the 6th week onwards there is an initially steep and later on less pronounced decrease until at an age of about 1 year a value of about 1.5 vol.-% is reached, which is maintained in adult life. — The decrease in the percentage of capillary volume seen after the 5th week is caused by the rapid increase in fibrous material due to myelination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00521979
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Influence of insulin on cyclic 3′,5′-AMP phosphodiesterase activity in liver, skeletal muscle, adipose tissue, and kidney (1968)
    Springer
    Diabetologia 4 (1968), S. 322-329 
    Details
    ISSN: 1432-0428
    Keywords: Insulin ; 3′,5′-AMP phosphodiesterase ; glycogen metabolism ; lipolysis ; insulin secretion ; antilipolytic action of insulin ; glycogen synthesis and insulin ; cyclic adenosine 3′,5′-monophosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'influence de l'insuline sur le métabolisme du glycogène hépatique et sur la lipolyse semble s'exercer par l'intermédiaire d'une diminution de la concentration de 3,′5′-AMP intracellulaire. Onamontré une diminution de la formation de 3′5′-AMP dans le tissu adipeux incubé avec de l'insuline. L'influence de l'insuline sur la dégradation du 3,′5′-AMP est étudiée. — L'activité de la 3,′5′-AMP-phos-phodiestérase (PDE) est diminuée dans le foie, le tissu adipeux et, de façon non-significative, dans le muscle strié des rats qui manquent d'insuline, c-à-d les rats rendus diabétiques par l'alloxane ou les rats privés de nourriture. L'injection intraveineuse d'une faible dose d'insuline (0.5 U/kg) ou la stimulation de la sécrétion d'insuline endogène par une injection de glucose provoquent une augmentation rapide de l'activité de la phosphodiestérase dans ces tissus. 15 min après l'injection d'insuline, l'activité de la phosphodiesterase du foie est augmentée. L'effet maximum est atteint après 30–45 min. L'activité de la phosphodiestérase rénale n'est pas diminuée dans le diabète alloxanique, l'injection d'insuline s'est avérée inefficace.In vitro, l'insuline cristalline a un effet activant sur la phosphodiestérase purifiée du coeur de boeuf. La concentration d'insuline requise pour doubler l'activité de l'enzyme est de l'ordre de 2 · 10−5 M. Le traitement avec actinomycin D empêche la stimulation par l'insuline de la PDE dans le foie. Ceci peut indiquer que l'action de l'insuline sur l'activité de la phosphodiestérase est essentiellement basée sur une synthèse accrue de l'enzyme. A cause de l'influence de la sécrétion d'insuline sur la concentration en 3,′5′-AMP du foie et du tissu adipeux, le métabolisme du glycogène et la lipolyse peuvent s'adapter rapidement à la prise de nourriture.
    Abstract: Zusammenfassung An der Steigerung der Glykogensynthese der Leber und der Verminderung der Lipolyse durch Insulin ist eine Abnahme der 3′,5′-AMP-Konzentration wesentlich beteiligt. Die 3′,5′-AMP-Bildung ist in Fettgewebe, das mit Insulin inkubiert wird, vermindert. Insulin beeinflußt jedoch auch den 3′,5′-AMP-Abbau. -Die 3′,5′-AMP-Phosphodiesterase (PDE)-Aktivität des Fettgewebes, der Leber und, in geringerem Grade, der Skeletmuskulatur ist im Insulinmangel vermindert, d.h. bei alloxandiabetischen oder hungernden Ratten. I.v. Injektion von 0,5 E/kg Insulin oder eine erhöhte Abgabe von Insulin aus dem Pankreas nach Glucoseinjektion führen in diesen Geweben zu einem raschen Anstieg der PDE-Aktivität. Dieser ist in der Leber schon 15 min nach Insulingabe nachweisbar und erreicht nach 30–45 min sein Maximum. In der Niere ist kein Einfluß von Insulin auf die PDE-Aktivität nachweisbar. — Aus Rinderherz isolierte PDE wirdin vitro durch Insulin aktiviert, jedoch werden2 · 10−5 M zur Verdopplung der Aktivität benötigt. Actinomycin D verhindert die Steigerung der Leber-PDE-Aktivität nach Insulininjektion. So kann die Wirkung des Hormons im wesentlichen auf eine gesteigerte PDE-Synthese zurückgeführt werden. — Durch diesen Einfluß der Insulininkretion auf die 3′,5′-AMP-Konzentration in Leber und Fettgewebe können Glykogenstoffwechsel und Lipolyse rasch an die Nahrungsaufnahme angepaßt werden.
    Notes: Summary Influence of insulin on liver glycogen metabolism and on lipolysis appears to be mediated by a decreased intracellular 3′,5′-AMP concentration. Reduced formation of 3′,5′-AMP had been shown in adipose tissue incubated with insulin. The influence of insulin on 3′,5′-AMP degradation has been investigated. — 3′,5′-AMP phosphodiesterase (PDE) activity was reduced in liver, adipose tissue and, insignificantly, in skeletal muscle of insulin deficient, i.e. alloxan diabetic or starved rats. I.V. injection of a low dose of insulin (0.5 U/kg) or stimulation of endogenous insulin secretion by injection of glucose led to a rapid increase of PDE activity in these tissues. 15 min after insulin injection liver PDE activity was increased. The maximal effect occurred after 30–45 min. Renal PDE activity was not decreased in alloxan diabetes, insulin injection has been found ineffective. —In vitro, there was an activating effect of crystalline insulin on PDE purified from beef heart. Insulin concentration required for duplication of enzyme activity was of the order of 2 · 10−5 M. Treatment with actinomycin D nearly prevented stimulation of liver PDE by insulin. This may indicate that the action of insulin on PDE activity is essentially based on an increased enzyme synthesis. — Owing to the influence of insulin secretion on liver and adipose tissue 3′,5′-AMP concentration, glycogen metabolism and lipolysis can be quickly adapted to food intake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01211766
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Human growth hormone as a regulator of blood glucose concentration and as a diabetogenic substance (1968)
    Springer
    Diabetologia 4 (1968), S. 1-9 
    Details
    ISSN: 1432-0428
    Keywords: Human growth hormone ; Growth hormone ; Insulin ; Diabetes mellitus ; Experimental diabetes ; Acromegaly ; Pathogenesis of diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Il a été démontré récemment que l'hormone de croissance humaine (HGH) joue un rôle prééminent dans la régulation normale de la glycémie. De plus, il est bien connu que l'hormone de croissance peut créer un état semblable au diabète chez l'animal. Chez l'homme, l'injection de HGH ou l'hypersécrétion de l'hormone endogène dans l'acromégalie est suivie d'intolérance au glucose seulement dans 25% des cas. — Dans ce travail nous présentons des données qui mettent l'action dite diabétogène de HGH dans un contexte plus nuancé. Nous suggérons que HGH, bien que diminuant l'utilisation du glucose par les tissus périphériques, n'est pas une substance primairement diabétogène, car l'effet insulinotrope de l'hormone cause une hyperinsulinémie compensatrice, qui à son tour normalise la tolérance au glucose. HGH est diabétogène exclusivement chez les sujets prédiabétiques dont le pancréas est incapable de répondre à l'effet insulinotrope de l'hormone. Chez ces sujets, la diabétogénicité de HGH n'étant pas surmontée par une hyperinsulinémie compensatrice, la tolérance au glucose sera anormale. Ainsi, HGH peut être considérée comme unfacteur additif pour la pathogénèse du diabète sucré, la condition essentielle et primaire étant un état préexistant de prédiabète.
    Abstract: Zusammenfassung Wie kürzlich gezeigt wurde, spielt das menschliche Wachstumshormon (HGH) eine wichtige Rolle bei der Kontrolle der Blutzucker-Homöostase. Ferner ist schon lange bekannt, daß die Verabreichung von Wachstumshormon an Tiere zu einem diabetesähnlichen Zustand führen kann. Beim Menschen löst die Gabe der Substanz oder die Überproduktion des endogenen Hormons bei der Akromegalie nur in etwa 25 % der Fälle eine Glucosetoleranzstörung aus. — In dieser Arbeit werden Resultate beschrieben, die ein detaillierteres Bild der sogenannten diabetogenen Wirkung des HGH vermitteln. Wir möchten annehmen, daß das HGH, obwohl es den peripheren Glucoseverbraueh herabsetzt, kein primär diabetogener Faktor ist, da es über eine Insulin-mehrausschüttung zu einem Hyperinsulinismus führt, der eine normale Glucosetoleranz bewirkt. HGH zeigt Scine diabetogene Wirkung nur bei Prädiabetikern, deren Pankreas den stimulierenden Effekt des Hormons auf die Insulinausschüttung nicht beantworten kann. Bei diesen Personen kann eine Störung der Glucosetoleranz dadurch entstehen, daß die diabetogene Wirkung des HGH nicht durch einen kompensatorischen Hyperinsulinismus ausgeglichen wird. HGH kann daher als ein Zusatzfaktor bei der Diabetesentstehung angesehen werden, deren Hauptvorbedingung jedoch eine schon vorher bestehende prädiabetische Stoffwechselsituation darstellt.
    Notes: Summary Human growth hormone (HGH) has recently been shown to play a prominent role in the control of blood glucose homeostasis. Furthermore, it has long been known that administration of growth hormone in animals can induce a diabetes-like state. In human subjects, exogenous administration of HGH or hypersecretion of the endogenous hormone in acromegaly is accompanied by glucose intolerance in only about 25 per cent of the cases. — In this paper, data are presented which give a more diversified picture of the so-called diabetogenic action of HGH. It is suggested that HGH, although decreasing the peripheral utilization of glucose, is not a primary diabetogenic factor, since its insulinogenic action causes a compensatory hyperinsulinism, with normal glucose tolerance as the result. HGH is diabetogenic only in prediabetic subjects whose pancreas is unable to respond to the insulinogenic effect of the hormone. In such subjects, the diabetogenic action of HGH not being counterbalanced by a compensatory hyperinsulinism, glucose intolerance may result. Thus, HGH may be regarded as anadditional factor for the development of diabetes, the major prerequisite being a preëxisting prediabetic state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01241026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The case for an “abnormal” insulin in diabetes mellitus (1968)
    Springer
    Diabetologia 4 (1968), S. 111-117 
    Details
    ISSN: 1432-0428
    Keywords: Insulin ; diabetes ; insulinase ; rat diaphragm ; glycogen synthesis ; RNA turnover ; cell culture ; anti-insulin serum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Peu de progrès conduisant à la compréhension du diabète en termes moléculaires ont été réalisés. La possibilité qu'il existe une modification dans la structure de l'insuline des diabétiques, aussi bien circulante que pancréatique, s'appuie sur trois arguments expérimentaux obtenus au laboratoire des auteurs. — La purification immunochimique de l'insuline circulante de diabétiques jeunes non traités par l'insuline a d'abord conduit à la constatation que cette insuline est relativement résistante à l'action réductrice et protéolytique d'une préparation d'insulinase musculaire. De plus, l'insuline pancréatique, isolée à partir de cinq pancréas diabétiques, s'est avérée d'activité biologique diminuée quant à son pouvoir d'augmenter la synthèse du glycogènein vivo et à sa capacité d'accélérer le “turnover” du R.N.A. en culture tissulaire. — La nature de cette „insuline anormale” et son rôle possible dans la physiopathologie du diabète sont examinés à la lumière de la nécessité de donner une définition spécifique de la modification moléculaire précise.
    Abstract: Zusammenfassung Unsere Kenntnisse über den Diabetes in molekularbiologischer Sicht haben kaum Fortschritte gemacht. Die Möglichkeit, daß das zirkulierende und das Pankreas-Insulin des Diabetikers strukturelle Unterschiede aufweisen, wird durch die Ergebnisse von drei verschiedenen Untersuchungsreihen gestützt, die im Laboratorium der Verfasser durchgeführt wurden. — Immunologisch gereinigtes zirkulierendes Insulin von Diabetikern, die noch kein Insulin erhalten hatten, erwies sich als recht widerstandsfähig gegenüber dem Abbau durch ein Insulinase-Rohextrakt aus Muskelgewebe. Aus den Bauchspeicheldrüsen von 5 Diabetikern gewonnenes Insulin zeigte sowohl in seiner Fähigkeit, die Glycogen-Synthesein vivo, als auch den Ribonucleinsäuren-Umsatz in der Gewebskultur zu stimulieren, eine herabgesetzte biologische Aktivität. — Bei der Diskussion der Natur dieses „abnormen” Insulins und seiner hypothetischen Rolle in der Physiopathologie des Diabetes ergibt sich besonders deutlich, wie dringend erforderlich eine genauere Klärung des in diesem Falle vorliegenden molekularen Umbaus ist.
    Notes: Summary Understanding of diabetes in molecular terms has advanced very little. The possibility that a structural difference exists in the circulating and pancreatic insulin moiety of diabetics is supported by three lines of evidence obtained in the authors' laboratory. — Immunologically purified circulating insulin from diabetic subjects untreated with insulin was noted to be relatively resistant to degradation by a crude muscle insulinase preparation. The pancreatic insulin of five diabetic pancreases was found to have a decreased biological activity in its ability to enhance glycogen synthesisin vivo and in its capacity to stimulate RNA turnover in tissue culture. — The nature of this “abnormal insulin” and its hypothetical role in the physiopathology of diabetes are discussed in the light of the need for a specific definition of the precise molecular change.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01219430
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The biosynthesis of insulin and ‘proinsulin’ in fœtal bovine pancreas (1968)
    Springer
    Diabetologia 4 (1968), S. 68-70 
    Details
    ISSN: 1432-0428
    Keywords: Insulin ; proinsulin ; biosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Après incubation de tranches de pancréas d'embryon de veau, la leucine-H3 est incorporée dans une fraction protéique qui semble avoir les propriétés d'une “proinsuline”. Cette fraction protéique est de taille supérieure à l'insuline, possède l'immunoréactivité propre à l'insuline, et après traitement limité par la trypsine elle est transformée en un peptide semblable à l'insuline.
    Abstract: Zusammenfassung Die Inkubierung von Dünnschnitten des fötalen Rinder-Pankreas in Gegenwart vom H3- Leucin ergab einen Einbau dieser Amminosäure in eine Eiweißfraktion, die die Eigenschaften eines, Pro-Insulins' aufwies. Das Molekulargewicht dieser Eiweißfraktion war größer als dasjenige des Insulins; sie besaß die Immunreaktivität des Insulins und konnte durch teilweisen Abbau mit Trypsin in ein insulinähnliches Peptid umgewandelt werden.
    Notes: Summary Incubation of fœtal bovine pancreas slices resulted in the incorporation of3H-leucine into a protein fraction which appeared to have the properties of a ‘proinsulin’. This protein fraction was larger in size than insulin, possessed the immunoreactivity of insulin and was converted by limited trypsin treatment to a peptide similar to insulin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01241035
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Insulin in bile: Studies on the effect of bile acids on the radioimmunoassay of insulin (1968)
    Springer
    Diabetologia 4 (1968), S. 281-285 
    Details
    ISSN: 1432-0428
    Keywords: Insulin ; radioimmunoassay ; bile ; bile acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'effet des acides biliaires sur le dosage radioimmunologique de l'insuline a été examiné et les résultats ont montré que les acides biliaires en concentrations physiologiques nuisent à la liaison de l'insuline avec le sérum anti-insulinique. La courbe de dilution de l'insuline immunoréaetive dans la bile de la vésicule biliaire porcine n'était pas parallèle à celle de l'insuline porcine standard. Après extraction de la bile porcine par du sérum antiinsulinique et après dosage de l'extrait, des taux d'insuline plus bas ont été trouvés. Les résultats suggèrent qu'une partie seulement de «l'insuline immunoreactive» de la bile de la vésicule biliaire représente de l'insuline véritable.
    Abstract: Zusammenfassung Die Wirkung von Gallensäuren auf die radio-immunologische Insulinbestimmung wurde untersucht. Aus den Resultaten geht hervor, daß Gallensäuren in physiologischen Konzentrationen zu einer Störung der Insulinbindung an Anti-Insulinserum führen. Die Verdünnungskurve von immunoreaktivem Insulin im Gallensaft aus Schweinegallenblasen verlief nicht parallel zur Standard-Eichkurve von Schweineinsulin. Nach Extraktion der Schweinegalle mit Anti-Insulinserum fanden sich im Extrakt niedrigere Insulinkonzentrationen. Die Ergebnisse deuten darauf hin, daß nur ein Teil des „immunoreaktiven Insulins” in der Blasengalle echtes Insulin ist.
    Notes: Summary The effect of bile acids on the radioimmunoassay of insulin has been investigated, and the results show that bile acids in physiological concentrations interfere with the binding of insulin by anti-insulin serum. The dilution curve of immunoreactive insulin in pig gall-bladder bile was not parallel to that of standard pig insulin. After extraction of pig bile with anti-insulin serum and assay of the extract, lower insulin levels were found. The results suggest that only a part of the “immunoreactive insulin” in gall-bladder bile is genuine insulin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01309902
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Vergleichende Untersuchungen über die Reaktionsweise des jugendlichen und des erwachsenen Gehirnes nach intracerebraler Injektion von Aluminiumhydroxyd (1968)
    Springer
    Acta neuropathologica 11 (1968), S. 311-329 
    Details
    ISSN: 1432-0533
    Keywords: Alumina Cream ; Intracerebral Injection ; Pathology of Growing Brain ; Myelination ; Demyelination ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zum Studium der Reaktion des jugendlichen und erwachsenen Gehirnes auf einen chronischen Reiz wurden bei Katzen verschiedenen Lebensalters intracerebrale Injektionen von Aluminiumhydroxyd vorgenommen. Die Tiere wurden nach Überlebenszeiten von 7 Tagen, 40 Tagen und 3 Monaten durch Perfusion mit Bouinscher Lösung getötet. Die histologische Untersuchung der Gehirne ergab eine Reihe von Unterschieden, je nachdem ob die Injektion vor oder nach der Markscheidenbildung erfolgt war. Besonders auffällig war der Befund, daß in der noch unmyelinisierten weißen Substanz jugendlicher Tiere kein Hirnödem und keine Gliose auftritt. Obgleich durch fluorescenzmikroskopische Untersuchungen gezeigt werden konnte, daß das Aluminium von der Injektionsstelle aus weit in das umgebende Hirngewebe eindringt und dort über lange Zeit festgehalten wird, werden bei den jungen Tieren die Markscheiden später bis in die unmittelbare Umgebung des Herdes normal angelegt. Bei erwachsenen Tieren kam es dagegen in der Nachbarschaft des Herdes stets zu einem starkem Ödem der weißen Substanz, zum Zerfall der Markscheiden und zu einer ausgebreiteten Gliose. Weitere Unterschiede in der Reaktionsweise des Gehirnes jugendlicher und erwachsener Tiere, die den Cortex und insbesondere die marginale Gliafaserschicht betreffen, werden im einzelnen beschrieben und diskutiert.
    Notes: Summary In order to compare the reaction to chronic irritation of young and adult brain intracerebral injections of alumina cream were made in cats of various ages. The animals were killed by perfusion with Bouin's fluid after a survival time of 7 days, 40 days, and 3 months. Histological investigation revealed gross differences in the reaction according to whether the intracerebral injections had been made before or after myelination. Particularly striking was the finding that in the non-myelinated white matter of young animals there was no edema and no subsequent gliosis. Although alumina, as evidenced by fluorescence microscopy after staining with Morin, spreads into the tissue surrounding the focus, subsequent myelination appeared to be normal even in regions close to the site of injection. In contrast, injection into the brains of adult animals was followed by edema, widespread demyelination and gliosis of the white matter near the site of injection. Further differences between young and adult animals were found in the reaction of the grey matter and particularly of the marginal glia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00686728
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Inhibition of local calcergy by topical application of calciphylactic challengers (1968)
    Springer
    Calcified tissue international 2 (1968), S. 67-76 
    Details
    ISSN: 1432-0827
    Keywords: Calcergy ; Calciphylaxis ; Calcium ; Metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Chez le rat, des expériences ont montré que, sauf de rares exceptions, les calcifications produites au site d'injection d'acétate de plomb, de chlorure de cérium, chlorure de calcium ou de permanganate de potassium sont complètement prévenues ou fortement inhibées par l'application locale simultanée de provocateurs calciphylactiques, mais non par des agents non provocateurs. Malgré quelques exceptions (attribuées à des interrelations chimiques spécifiques entre certaines des substances utilisées), cette curieuse corrélation entre l'efficacité calciphylactique provocatrice et le pouvoir anticalcergique est, d'après le test χ2, hautement significative (P〈0,001).
    Abstract: Zusammenfassung Nach subcutaner Injektion von Bleiacetat, Ceriumchlorid, Calciumchlorid oder Kaliumpermanganat tritt an der Injektionsstelle eine starke Verkalkung auf. Bis auf sehr wenige Ausnahmen kann diese durch gleichzeitige lokale Anwendung von calciphylaktischen Provokatoren verhütet oder weitgehend unterdrückt werden. In dieser Beziehung sind nicht provolatorisch wirkende Stoffe inaktiv. Trotz der wenigen Ausnahmen (die wahrscheinlich auf spezifische, chemische Wechselwirkungen zwischen manchen der untersuchten Substanzen beruhen) ist dieser merkwürdige Zusammenhang zwischen calciphylaktisch provozierender und anticalcergischer Aktivität, nach dem χ2-Test berechnet, statistisch hochsignifikant (P〈0,001).
    Notes: Abstract Experiments on rats indicate that, with very few exceptions, the calcification which occurs at subcutaneous sites of treatment with lead acetate, cerium chloride, calcium chloride or potassium permanganate is completely blocked or severely inhibited by simultaneous topical application of calciphylactic challengers but not of non-challengers. Despite the few exceptions (which are thought to depend upon specific chemical interactions between some of the compounds tested) this singular correlation between calciphylactic challenging and anticalcergic potency, is highly significant by the Chi-square-test (P〈0.001).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02279195
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Calcium binding by chondroitin sulfate (1968)
    Springer
    Calcified tissue international 2 (1968), S. 253-261 
    Details
    ISSN: 1432-0827
    Keywords: Calcium ; Ion ; Binding ; Chondroitin ; Cartilage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La liaison du calcium par le sulfate de chondroitin C a été étudiée en utilisant des méthodes biologiques et physicochimiques pour la détermination quantitative du calcium ionique. Les valeurs moyennes pour logK j, le logarithme de la constante de formation non corrigée d'un complexe calcium-sulfate de chondroitin C, sont 1,64 par la technique de cœur de grenouille, 1,55 par la méthode de murexide, 1,39 par l'ultrafiltration et 1,04 par l'électrode sélective du calcium. L'ordre de grandeur de ces valeurs suggèrent que le sulfate de chondroitin C a une capacité de liaison pour calcium relativement élevée, mais les valeurs calculées pour un paramètre d'échangeK p indiquent que le calcium a une affinité faible pour le polysaccharide.
    Abstract: Zusammenfassung Die Bindung von Calcium mit Chondroitinsulfat C wurde untersucht mittels biologischer und physikalisch-chemischer Methoden für die quantitative Bestimmung des ionischen Calciums. Im Durchschnitt ergab logK j, der Logarithmus der unkorrigierten Formationskonstante für einen Calciumchondroitinsulfatkomplex, 1,64 mit der Technik des Froschherzens, 1,55 mit der Murexidmethode, 1,39 mittels Ultrafiltration und 1,04 mit den Calciumselektiven Elektroden. Die Größe dieser Werte zeigt, daß Chondroitinsulfat eine relativ hohe Bindungskapazität für Calcium hat, die berechneten Werte für einen AustauschparameterK p jedoch, daß Calcium eine kleine Affinität für Polysaccharide hat.
    Notes: Abstract The binding of calcium by chondroitin sulfate C was studied by employing biological and physicochemical methods for the quantitative determination of ionic calcium. Mean values for logK j, the logarithm of the uncorrected formation constant for a calcium-chondroitin sulfate complex, were 1.64 with the frog heart technique, 1.55 with the murexide method, 1.39 with ultrafiltration and 1.04 with the calcium selective electrode. The magnitude of these values suggests that chondroitin sulfate has a relatively high binding capacity for calcium, but calculated values for an exchange parameterK p indicate that calcium has a low affinity for the polysaccharide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02279213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Calcium transport by the intestine: A model and comment on vitamin D action (1968)
    Springer
    Calcified tissue international 2 (1968), S. 301-313 
    Details
    ISSN: 1432-0827
    Keywords: Calcium ; Absorption ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02279219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Effect of disuse osteoporosis on bone composition: the fate of bone matrix (1968)
    Springer
    Calcified tissue international 2 (1968), S. 20-29 
    Details
    ISSN: 1432-0827
    Keywords: Bone Atrophy ; Bone Resorption ; Calcium ; Collagen ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Atrophie osseuse d'immobilisation était induite par section de la plexus brachial et/ou désarticulation de la coude. Après 9 bis 12 semaines de désuétude huméri intactes furent examinés par rayons X et leur qualités physiques déterminés. Les humérientiers furent isolés, dégraissés, desséchés au poids constant, et leur teneur en cendre d'os et collagène déterminés. Huit des 10 huméri immobilisés monstrérent radiodensité diminué. La jambe inusitée monstra perte parallèle en poids sec et poids sans gras (−23.2%), en collagène (−25.3%), et en cendre d'os (−26.1%) en comparaison de la jambe normale. Les données monstrèrent que la portion plus grande du tissu osseux perdu en atrophie osseuse d'immobilisation est remplacée par de l'eau, du gras, et des autres matériels organiques inconnus plutôt que par tissu fibreux, et que collagène est perdu en proportion du minéral. La perte proportionellement plus grande du collagène et de la cendre d'os que du poids sec et poids san gras semble dû à une augmentation du matériel organique, non-collagéne, non-lipide, kprobablement protéine.
    Abstract: Zusammenfassung Immobilisations-Knochenatrophie wurde in 10 erwachsenen Hunden herbeigeführt durch Brachialplexusschnitt und/oder Ellenbogenexartikulation. Nach 9–12 Wochen der Immobilisation wurden die intakten Humeri unter Röntgenstrahlen untersucht und ihre physischen Eigenschaften bestimmt. Derintakte Humerus wurde isoliert, entfettet, zu konstantem Gewicht getrocknet und der Knochenaschengehalt und Kollagengehalt bestimmt. Acht der 10 experimentellen (immobilisierten) Humeri demonstrierte Beweis von verringerter Röntgendichte. Die immobilisierte Extremität zeigte ähnlichen Verlust in trockenem, fettfreiem Gewicht (−23,2%) in Kollagen (−25.3%) und Knochenasche (−26,1%) im Vergleich zur normalen Extremität. Die Date deuten an, daß der Hauptanteil des Verlustes des Knochengewebes (bei Immobilisations-Knochenatrophie) von Wasser, Fett und anderen unidentifizierten organischen Substanzen ersetzt wird, als von Faserngewebe und daß Kollagen und Knochenasche im gleichen Verhältnis verloren gehen. Der größere, proportionale Verlust an Kollagen und Knochenasche, eher als der Verlust an fettfreiem Gewicht, scheint in der Zunahme an nicht kollagener, nicht lipoider, organischer Substanz, vermutlich Protein, zu liegen.
    Notes: Abstract Disuse bone atrophy was induced in 10 adult dogs by means of brachial plexus section and/or elbow disarticulation. After 9 to 12 weeks of disuse intact humeri were examined by X-ray, and their physical properties determined. Thewhole humeri were isolated, defatted, dried to constant weight, and their mineral and collagen content determined. Eight out of 10 experimental (non-used) humeri demonstrated evidence of decreased radiodensity. The non-used limb demonstrated parallel loss in dry, fat-free weight (−23.2%), in collagen (−25.3%), and in mineral (−26.1%), as compared to the normal limb. The data indicated that the major portion of the lost bone tissue in disuse osteoporosis is replaced by water, fat, and other unidentified organic materials rather than fibrous tissue, and that collagen is lost in equal proportion to mineral. The proportionatelly greater loss of collagen and mineral than of dry, fat-free weight appears to be due to an increase of non-collagenous, non-lipid organic material, presumably protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02279190
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    The separation and identification of fractions of nonmyelinated axons from the cerebellum of the cat (1968)
    Springer
    Experimental brain research 5 (1968), S. 326-340 
    Details
    ISSN: 1432-1106
    Keywords: Subcellular fractionation ; Parallel fiber axons ; Cerebellum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fractionation of the cat cerebellum has revealed that the parallel fibers of the cerebellar cortex break into two types of fragments which can be recognized in thin sections and in suspensions of negatively stained material. Fragmented material correlates well with electron micrographs of parallel fibers in situ. Parallel fiber axons and their bulbous presynaptic expansions sediment mainly into two subfractions. One unique layer consists of the intersynaptic tubular pieces of parallel fiber axons. Another layer is enriched in the synaptic portions which make contact with Purkinje spines. The possible contaminants of these fractions are discussed. These fractions may permit analysis of the chemical organization of conducting vis à vis synaptic membranes from a known anatomical source. This material was presented as a preliminary report at the Sixth Annual Meeting of the American Society for Cell Biology, November 1966, and is contained in J. Cell. Biol. 31, 52A, 1966.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235907
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Tactile discrimination study of the dorsal column-medial lemniscal system and spino-cervico-thalamic tract in cat (1968)
    Springer
    Experimental brain research 6 (1968), S. 234-246 
    Details
    ISSN: 1432-1106
    Keywords: Tactile discrimination ; Dorsal column-medial lemniscus ; Spino-cervico-thalamic tract ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of two spinal sensory pathways, the dorsal column (DC) pathway and the spino-cervico-thalamic tract (SCTT), involved in tactile discrimination was studied. Pour lesion groups of cats (DC lesion, SCTT lesion, combined DC and SCTT lesion, and sham-operated) were tested to discriminate various degrees of roughness. Animals with either the SCTT or the combined lesions performed at around 50–60% level under all the conditions tested. On the other hand, those with the DC lesion and sham-operations generally attained 80–100% level of performance. A difference between the DC group and sham-operated group was found in their rate of learning and ability for finer discrimination. These results are interpreted as an indication that a duplicity in transmission of tactile sensation exists, the DC pathway being more specific than the SCTT.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    EEG frequency content related to regional blood flow of cerebral cortex in cat (1968)
    Springer
    Experimental brain research 5 (1968), S. 55-60 
    Details
    ISSN: 1432-1106
    Keywords: EEG frequency ; Regional cortical blood flow ; Isotope measurements ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The EEG frequency content in cats, anaesthetized by Nembutal and artificially ventilated, was altered by means of injections of either additional Nembutal or of Metrazol. The EEG in cerveau isolé preparations was also changed in the same way. The regional cortical blood flow was determined by means of the 85Krypton technique. A high correlation was found between the frequency content of the EEG, measured by means of manual frequency analysis, and the regional cortical blood flow. The cortical blood flow increased when the mean frequency increased, and vice versa. A similar correlation was found when the EEG mean frequency was changed by means of sensory stimulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239905
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Elimination by hypoxia of cerebral blood flow autoregulation and EEG relationship (1968)
    Springer
    Experimental brain research 5 (1968), S. 61-71 
    Details
    ISSN: 1432-1106
    Keywords: EEG frequency ; Regional cortical blood flow ; Isotope measurements ; Effects of hypoxia ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The relationship between cortical blood flow and the frequency content of the EEG was studied in a circumscribed area of the exposed cerebral cortex in cats under nitrous oxide-oxygen anaesthesia. Autoregulation of the cortical blood flow was also tested during step-changes of the arterial blood pressure. Observations were made before and after an episode of severe hypoxia. 2. An episode of systemic hypoxia disrupted the normal high correlation between cortical blood flow and EEG frequency content. In the post-hypoxic period cortical flows of up to about three times normal values were recorded together with brain swelling and a slow wave EEG. The hyperemia and swelling subsided during 1–2 h after the hypoxic episode, and were accompanied by partial or complete recovery of the EEG. In the post-hypoxic period a defective autoregulation of the cortical blood flow to changes in the systemic blood pressure was demonstrated. 3. The cerebral post-hypoxic state with hyperaemia, brain swelling, EEG depression, and loss of autoregulation of blood flow, is probably caused by an accumulation of anaerobic metabolites which lead to cerebral tissue acidosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239906
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    The corticothalamic projection from the gyrus proreus and the medial wall of the rostral hemisphere in the cat an experimental study with silver impregnation methods (1968)
    Springer
    Experimental brain research 5 (1968), S. 129-152 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex ; Thalamus ; Cat ; Nauta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The corticothalamic projections from the gyrus proreus and the medial wall of the rostral hemisphere have been studied in the cat with the silver method of Nauta. The gyrus proreus projects upon the following nuclei (for abbreviations, see list on page 133), ipsilateral R, VA, VM, VL, MD, Pc, CL, CM, Pf, VPM, VPMpc. VPI and to the contralateral principal nucleus of the trigeminal nerve. The medial wall of the rostral hemisphere projects bilaterally upon R, VA, VM, VL, MD, Pc, CL, CM, Pf, VPM, VPMpc, VPI, VPL, the dorsal column nuclei and the principal nucleus of the trigeminal nerve. The ipsilateral thalamic projection is more abundant than the contralateral. The latter appears to increase in amount as the lesion is placed successively more ventrally on the medial wall of the rostral hemisphere. Some degenerating fibers cross in the corpus callosum and descend in the contralateral internal capsule but the majority cross in the dorsal part of the anterior commissure and reach the medial aspect of the anterior limb of the contralateral internal capsule. A somatotopical organization of the medial wall of the rostral hemisphere has been demonstrated. The rostrocaudal part projects upon the ipsilateral VPL lateralis (VPLl) and nucleus cuneatus and the contralateral nucleus gracilis and VPL medialis (VPLm). The caudal part of this cortical area sends fibers bilaterally to VPM, VPMpc, and the principal nucleus of the trigeminal nerve. The intermediate part, which also includes agranular cortex on the medial wall, projects upon ispsilateral VPLm and nucleus gracilis and upon contralateral VPLl and nucleus cuneatus. — The fibers to the ventro-basal complex, dorsal column nuclei and the principal nucleus of the trigeminal nerve are rather thick. The corticofugal fibers to the other thalamic nuclei are quite thin. — The findings are discussed in light of relevant anatomical and physiological observations in the literature and special emphasis has been laid on reported observations on the “supplementary motor” area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238702
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    The corticothalamic projection from the second somatosensory cortical area in the cat an experimental study with silver impregnation methods (1968)
    Springer
    Experimental brain research 5 (1968), S. 153-172 
    Details
    ISSN: 1432-1106
    Keywords: SII ; Thalamus ; Cat ; Somatotopical localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The corticothalamic projection from the anterior ectosylvian gyrus in the cat has been studied with the silver impregnation method of Nauta. The second somatosensory cortical area (SII) projects upon the ipsilateral nucleus ventralis posterolateralis (VPL), nucleus ventralis posteromedialis (VPM), the posterior thalamic region (PO) and to a slight extent upon the reticular nucleus of the thalamus (R), the centrum medianum (CM), the parvocellular part of VPM (VPMpc) and the nucleus ventralis posterior inferior (VPI). A somatotopical arrangement in the projection upon the ventro-basal (VB) complex has been demonstrated and a topical arrangement in the corticothalamic fibers from SII to PO is also evident. The transitional area between SII and the second auditory cortex sends fibers mainly to the entire magnocellular part of the medial geniculate body (MGmc) and to a lesser degree to the principal division of this nucleus (MGp). The corticofugal fibers from SII follow various and rather complicated circuitous routes before they end in the different thalamic nuclei. The experimental findings are discussed in the light of recent anatomical and physiological observations. It is shown that zones B and C of SII which have been shown by Carreras and Andersson (1963) to possess a large number of place and modality specific neurons project upon the VB-complex. On the other hand, zone A which contains a majority of place and modality unspecific neurons sends its fibers exclusively to PO. Finally the problem of thalamocortical projections to SII is briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238703
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    The corticopontine projection in the cat I. Demonstration of a somatotopically organized projection from the primary sensorimotor cortex (1968)
    Springer
    Experimental brain research 5 (1968), S. 210-234 
    Details
    ISSN: 1432-1106
    Keywords: Sensorimotor cortex ; Pontine nuclei ; Somatotopical localization ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Small lesions (in some cases bilateral) were made in the cerebral primary sensorimotor region in altogether 21 adult cats and the ensuing degeneration in the pontine nuclei was studied with the silver impregnation methods of Nauta and Glees. Using thermocoagulation it was possible to obtain lesions restricted entirely to particular cortical regions (for example the “hindlimb region” in the posterior sigmoid gyrus). The main results are as follows: 1. All parts of the primary sensorimotor region send fibres to the pontine nuclei. The projections from the posterior part of the posterior sigmoid gyrus and the posterior part of the coronal gyrus are relatively scanty. 2. The cortical “motor” area (the anterior sigmoid gyrus and the anterior part of the coronal gyrus) and the “sensory” area (the posterior sigmoid gyrus and the posterior part of the coronal gyrus) do not project to identical pontine regions, although both projections are organized in principally the same way. 3. The “motor” and “sensory” areas both project in a somatotopical manner onto two longitudinally oriented sharply delimited columns. In both projections one column is located medial and one lateral to the longitudinal fibre bundles of the corticospinal and corticobulbar tracts. Within the medial columns the “hindlimb” is represented ventrally with “face” most dorsally, within the lateral columns the “hindlimb” is located most caudally, with “forelimb” and “face” successively more rostrally. 4. The present results are in agreement with physiological observations on the cerebrocerebellar relations, but show that the pontine projection from the primary sensorimotor cortex is organized in a more complex manner than hitherto assumed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238665
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Die aktivität von Einzelfasern des nervus opticus bei verschiedenen temperaturen (1968)
    Springer
    Experimental brain research 4 (1968), S. 321-329 
    Details
    ISSN: 1432-1106
    Keywords: Temperature ; Interval histograms ; Optic nerve ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In 13 Katzen wurde die Aktivität von 128 Einzelfasern des N. opticus bei Temperaturen zwischen 27 und 39° C abgeleitet und direkt einer Intervallanalyse zugeführt. Die Durchschnittsfrequenz sank mit abnehmender Temperatur von 56/sec bei 39–37° C auf 21/sec unter 29° C. Bei Temperaturen über 35° C wurden nur unimodale oder zweigipfelige Verteilungen mit gehäuften Mehrfachentladungen gefunden. Unter 35° C traten multimodale Intervallhistogramme und Übergangstypen auf, bei denen einer Verteilung mehrere Gipfel aufgesetzt erschienen. Unter 29° C wurden nur mehrgipfelige Verteilungen beobachtet. In der phasischen Reaktion der Neurone wurden mit der Temperaturabnahme Latenzen länger und Hemmungen stärker. Unter 30° C konnte der Reaktionstyp des Neurons oft nicht mehr erkannt werden. Das vermehrte Auftreten multimodaler Verteilungen bei niedrigen Temperaturen ließe sich durch Verminderung von Interaktionen in der Retina erklären. Die Anregung zu dieser Untersuchung wurde von Herrn Professor Dr. Hans Bornschein gegeben.
    Notes: Summary The activity of 128 single fibers of the optic nerve was recorded in 13 cats at temperatures between 27 and 39° C. Nonsequential interval histograms were computed on line. Decreasing temperature diminished the mean frequency of the fiber activity from 56/sec at 37–39° C to 21/sec below 29° C. Above 35° C the histograms were unimodal or bimodal, the first peak caused by repetitive discharges. Below 35° C multimodal histograms appeared; in some distributions several peaks were superimposed. At temperatures below 29° C only multimodal distributions were obtained. The phasic response of the neurons to light showed an increase of latency and of inhibition according to the decrease of temperature. Often the type of the response of the neuron could not be recognized below 30° C. During hypothermia interactions in the retina may be reduced and this may explain why multimodal distributions occur more frequently.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235699
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Messung des Calcium-Einflusses auf die Strom-Spannungsbeziehung der erregbaren Membran am Ranvier-Knoten (1968)
    Springer
    Pflügers Archiv 300 (1968), S. 23-34 
    Details
    ISSN: 1432-2013
    Keywords: Electro-Physiology ; Ranvier-Node ; Stationary Current-Voltage Relation ; Calcium ; Elektrophysiologie ; Ranvierscher Schnürring ; Stationäre Strom-Spannungscharakteristik ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Erhöht man die extracelluläre Calcium-Konzentration, so verschieben sich die Stromextrema der Strom-Spannungsbeziehung des Ranvier-Knotens nach Depolarisationsrichtung. Mit Hilfe einer Gleichung zur Darstellung der Kennlinien läßt sich diese Wirkung durch Änderung eines einzigen Parameters V Tγ beschreiben. Dieser gibt die Spannungslage des Abfalles einer Stufenfunktion wieder, die im Rahmen der Ionentheorie der Kaliumleitfähigkeitsvariablen n ∞ 4 (V) entspricht. Durch Erhöhung von [Ca··] a wird V Tγ nach Depolarisationsrichtung verschoben. Darüber hinaus konnte eine deutliche Abhängigkeit dieses Parameters von [K·] a festgestellt werden. Der Calcium-Einfluß auf das Membranpotential konnte als Konsequenz der Vt r −-Verschiebung interpretiert werden.
    Notes: Summary An increase of the extracellular calcium-concentration shifts the extreme current values of the current-voltage-relation of a Ranvier-node towards depolarization. This influence can be described by the change of one single parameter V Tγ of an equation representing the current-voltage-characteristic. V Tγ referres to the potential at which the s-shaped step-function of resistance change assumes the arithmetical mean of its limiting values. The step-function compares to the variable of potassium conductance n ∞ 4 (V). An increase of [Ca··] a shifts V Tγ towards depolarizing potentials. V Tγ is also found to depend on [K·] a . The influence of calcium on membrane potential is interpreted as a consequence of the observed shift of V Tγ .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00380845
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Elektrophysiologische Untersuchung von peripheren, corticalen und thalamischen Verbindungen zu Neuronen der bulbären Trigeminuskerne der Katze (1968)
    Springer
    Pflügers Archiv 299 (1968), S. 261-284 
    Details
    ISSN: 1432-2013
    Keywords: Cat ; Electrophysiology ; Single Units ; Bulbar Trigeminal Nuclei ; Katze ; Elektrophysiologie ; Einzelneurone ; Bulbäre Trigeminuskerne
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Funktionelle Eigenschaften der excitatorischen Verbindungen von Cortex, Thalamus und Peripherie zu 438 Neuronen der bulbären Trigeminuskerne wurden untersucht. Es konnten Beziehungen zwischen den Latenzzeiten der Antworten auf ipsilaterale, periphere Einzelreize, contralaterale thalamische Einzel- und Serienreize (N. ventralis posteromedialis) und contralaterale corticale Einzel- und Serienreize (somatosensorisches Projektionsgebiet S I, S II) nachgewiesen werden. 2. Für die Gesamtheit der Neurone wurde mit zunehmender Latenzzeit der Entladung auf periphere Reize eine Zunahme der prozentualen Ansprechbarkeit und der Latenzzeit der Antwort auf zentrale Reize beobachtet. 3. Die Neurone, deren periphere, thalamische und corticale Antworten Reizfrequenzen von 50 Hz und mehr folgten, hatten im Mittel kürzere periphere Latenzzeiten als Neurone, die Reizfrequenzen von 50 Hz nicht folgten. 4. Bulbäre Neurone, die mit thalamischen Reizen antidrom erregt wurden (lemniscale Neurone), unterschieden sich im Mittel von den übrigen Neuronen durch kürzere Latenzzeiten für periphere und zentrale Reize. 5. Es wurden lemniscale Neurone beobachtet, die mit corticalen Reizen monosynaptisch erregt werden konnten. 6. Neurone mit kleinen peripheren rezeptiven Feldern hatten im Mittel kürzere Latenzzeiten auf periphere Reize als Neurone mit großen rezeptiven Feldern. 7. Die periphere Reizantwort von Neuronen konnte durch vorausgehende thalamische und corticale Reize gehemmt werden. Im Mittel wurde die Hemmung bei Neuronen mit Latenzzeiten auf periphere Reize häufiger beobachtet. 8. Mögliche Bahnen, die an der Übertragung thalamo-bulbärer Effekte beteiligt sind, wurden diskutiert und schematisch dargestellt. Die Ergebnisse wurden mit statistischen Methoden geprüft.
    Notes: Summary 1. Functional properties of excitatory connections from cortex, thalamus and periphery to a total of 438 trigeminal bulbar neurons of the cat have been investigated extracellularly. For the sample considered, correlations between latency of response to ipsilateral electrical single stimuli, contralateral electrical thalamic single and serial stimuli (N. ventralis posteromedialis) and also contralateral electrical cortical single and serial stimuli (somatosensory areas S I, S II) were established. 2. With increasing peripheral latency of response, the percentage of neurons responding to central stimulation increased as well. 3. Neurons following thalamic, cortical or peripheral stimulation frequencies of 50 cps or more showed in the average shorter latencies of response compared with neurons that could not be driven with 50 cps stimulation. 4. Bulbar neurons antidromically invaded by stimulation of the thalamus showed shorter latencies to peripheral, thalamic and cortical stimuli compared with other neurons. 5. Lemniscal neurons that could be activated monosynaptically by cortical stimulation have been observed. 6. Neurons with a small peripheral receptive field had in the average a shorter latency to peripheral stimuli than neurons with a large receptive field. 7. Responses to peripheral stimuli could be inhibited by preceding thalamic and cortical stimuli. 8. Possible pathways that are involved in transmission of thalamo-bulbar effects have been discussed and schematically represented. 9. All results have been examined by means of statistical methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00362589
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Influence of microelectrophoretically applied acetylcholine on the responsiveness of hippocampal and lateral geniculate neurones (1968)
    Springer
    Pflügers Archiv 303 (1968), S. 173-180 
    Details
    ISSN: 1432-2013
    Keywords: Hippocampus ; Corpus geniculatum laterale ; Katze ; Mikroelektrophorese ; Acetylcholin ; Hippocampus ; Lateral Geniculate Body ; Cat ; Microelectrophoresis ; Acetylcholine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary 1. Hippocampal and lateral geniculate neurones in anaesthetized cats (Chloralose-Urethane) were examined with multibarrelled microelectrodes, testing their responsiveness to microelectrophoretic application of acetylcholine and photic stimulation. 2. In the ventral hippocampus and in the lateral geniculate body 60% of all neurones responded to acetylcholine. 3. Hippocampal neurones were activated with relatively short delay, often less than 1 sec. By contrast, lateral geniculate neurones responded with a latency period of 2–12 sec. The recovery time after acetylcholine-microelectrophoresis was found to be 10–20 sec in both regions. 4. The response of hippocampal and lateral geniculate neurones to photic stimulation was enhanced by local application of acetylcholine; even during phenobarbital depression the photic responses were restored by acetylcholinemicroelectrophoresis.
    Notes: Zusammenfassung 1. Neurone im Gebiet des Hippocampus und des Corpus geniculatum laterale der mit Chloralose-Urethan narkotisierten Katze wurden mit mehrkanüligen Mikroelektroden auf ihre Ansprechbarkeit auf mikroelektrophoretisch appliziertes Acetylcholin und auf optische Reizung untersucht. 2. Im ventralen Hippocampus und im Corpus geniculatum laterale wurden 60% aller untersuchten Neurone durch Acetylcholin aktiviert. 3. Die Neurone des Hippocampus wurden nach relative kurzer Latenz, oft weniger als 1 sec, aktiviert. Neurone des Corpus geniculatum laterale dagegen zeigten eine Latenz von 2–12 sec. Die Zeit nach der Mikroelektrophorese bis zur Wiedererreichung der normalen Aktivität betrug 10–20 sec für beide Gebiete. 4. Die Acetylcholin-Mikroelektrophorese verstärkte die Reizantwort der Neurone des Hippocampus und des Corpus geniculatum laterale auf visuelle Reizung. Die nach Phenobarbital abgeschwächte Antwort auf visuelle Reizung wurde durch Acetylcholin-Mikroelektrophorese wieder verstärkt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00592634
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Beziehungen zwischen Aktivität corticaler Neurone und EEG-Wellen im motorischen Cortex der Katze bei Hypoglykämie (1968)
    Springer
    European archives of psychiatry and clinical neuroscience 211 (1968), S. 43-62 
    Details
    ISSN: 1433-8491
    Keywords: Neuronal activity ; EEG-cortex ; Hypoglycemia ; Cat ; Neuronale Aktivität ; EEG-Cortex ; Hypoglykämie ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. An Katzen wurden EEG-Veränderungen durch Hypoglykämie hervorgerufen und mit den Aktivitätsveränderungen corticaler Neurone verglichen, wie sie sich bei intracellulären und „quasi-intracellulären“ Ableitungen darstellen. Es zeigte sich, daß pathologische EEG-Veränderungen erst bei niedrigen Blutzuckerwerten (zwischen 30 und 25 mg-%) auftreten und daß es erst bei Werten unter 10–15 mg-% zur elektrischen Stille kommt. 2. Während des flachen, desynchronisierten EEG des wachen Hirns vor Hypoglykämie lassen sich keine Beziehungen zwischen den kleinen EEG- und statistisch verteilten Zellpotentialen nachweisen. — Während der regelmäßigen 8–10/sec- Spindelgruppen, die bei tiefer Hypoglykämie häufig zu beobachten sind, findet sich eine enge Korrelation zwischen den einzelnen Oberflächen-negativen Spindelwellen und Zelldepolarisationen, die meist unterschwellig sind. 3. Bei den langsamen Wellen der δ-Frequenz finden sich ähnliche, aber weniger enge Korrelationen für die flachen, „monomorphen“ δ-Wellen. Andere Formen von langsamen Potentialkomplexen des Cortiocogramms, die im Tintenschreiber als „polymorphe“ δ-Wellen imponieren können, zeigen etwas andere, aber für den einzelnen Wellenkomplex jeweils konstante Beziehungen zur Zellaktivität. 4. Die steilen Wellen wurden unterteilt in primär positive und in primär negative bi- (oder auch tri-)phasische Potentiale. Die primäre Phase der primär-positiven steilen Potentiale ist im Durchschnitt kürzer (unter 20–40 msec) als die negative Phase der primär-negativen Phase (über 100 msec). Die meist überschwellige Zelldepolarisation, die in der Regel zu einer kurzen Gruppenentladung führt, fällt mit der primären Phase, also entweder der positiven oder der negativen zusammen. Die Phasenkoppelung, d. h. die „Synchronisation“ mit dem EEG-Potential, ist jedoch im Fall der primär-positiven Phase enger und die Dauer der Depolarisation kürzer als im Fall der primär-negativen steilen Potentiale. Diese Befunde werden als Hinweis auf eine stärkere Synchronisation der Aktivität der corticalen Nervenzellpopulation im Fall der primär-positiven steilen Potentiale gewertet. 5. Die verschieden engen Phasenkoppelungen und die je nach Steilheit der Wellen wechselnden Phasenbeziehungen zwischen Zellaktivierung und oberflächennegativen resp. -positiven Potentialen werden an Hand eines einfachen Modells der Elektrogenese von EEG-Potentialen erklärt, das den Synchronisationsgrad cortico-petaler und cortico-fugaler Faseraktivität sowie die Summation postsynaptischer Potentiale corticaler Neurone berücksichtigt.
    Notes: Summary 1. The EEG, recorded monopolarly from the pial surface, was investigated during insuline induced hypoglycemia in acute cats and compared with the activity of cortical cells recorded with intra or “quasi-intracellular” electrodes. 2. Pathological changes of the EEG were observed only when the blood glucose fell below 25–30 mg-%. Electrical silence was observed at blood glucose levels below 15–10 mg-%. 3. The essentially flat, “desynchronized” EEG of the awake animal before hypoglycemia did not show any relation between the small, irregular fast EEG- potentials and the statistically distributed cellular potentials. —During the regular 8–10/sec spindles (Fig. 3) a close correlation was found between the single surface- negative spindle waves and the mostly subthreshold compound cellular EPSP's. 4. Slow waves of δ-frequency showed similar but less close correlations, if the waves were of regular appearance comparable to “monomorphic” δ-waves (Fig.4A). Other forms of slow complex potentials (Fig.4B and C), which correspond to “polymorphic” δ-waves in an EEG-record (e.g. Fig.4C and Fig.2d) may show different relations between cellular and EEG-activity which were, however, consistent for each type of complex wave. 5. Sharp waves were divided into primary positive and primary negative bi- (or tri-)phasic potentials. The primary positive phase was always shorter (below 20–40 msec) than the primary negative phase (above 100 msec). The mostly suprathreshold cellular depolarization, which may lead to a short burst of discharge, coincided with the primary, i.e. either the primary positive or the primary negative phase (Fig. 7 shows records from the same cell and different EEG-phenomena). The phase coupling, i.e. the “synchronization” with the EEG-potential, is closer in the primary positive than the primary negative waves, and the duration of the cellular depolarization is also shorter in the former case (compare Fig.7B I–III with 7B IV). This can be interpreted as stronger synchronization of cellular activity during the short primary positive waves. 6. A causal relation between cortical neuronal activity and EEG-potentials is assumed. Differences in the closeness of phase coupling and the changing phase relation between cellular and EEG-activity according to the form and steepness of cortical EEG-potentials are explained by a simple model of electrogenesis of EEG-potentials, which takes in account the degree of synchronization of corticopetal and cortico-fugal fibre activity as well as the summation of postsynaptic potentials of cortical neurones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341671
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Schlaf-EEG und Epilepsie bei Katzen mit chronischen epileptogenen Hirnläsionen (1968)
    Springer
    European archives of psychiatry and clinical neuroscience 211 (1968), S. 155-169 
    Details
    ISSN: 1433-8491
    Keywords: Sleep EEG ; Experimental Epilepsy ; Cat ; Schlaf-EEG ; Experimentelle Epilepsie ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Frage der Wacho- der Schlaf-Aktivierung der fokalen Epilepsien wird bei 20 epileptischen Katzen im chronischen Experiment untersucht (Kopeloff-Methode). Die Narben wurden im Nucleus amygdaloideus (Pars basolateralis), Hippocampus dorsalis, Formatio reticularis mesencephali, Isocortex gesetzt. Bei einer Untersuchungsdauer der einzelnen Tiere zwischen 3 und 60 Tagen, wurden insgesamt 442 Std in Polygraphie (EEG, EMG, Augenbewegungen) abgeleitet. Die Tiere zeigten innerhalb der ersten 7 Tage Krampfpotentiale im EEG und die meisten ab der 2. Woche Krampfanfälle. Bei Katzen mit subcorticalen Narben war keine Veränderung der Dauer, der Verteilung und der Organisation der einzelnen Schlafstadien nachweisbar. Die im Ruhe-EEG vorhandenen Paroxysmen wurden während des langsamen Schlafes nicht aktiviert und fokalisiert. Im paradoxen Schlaf waren die Krampfpotentiale völlig desaktiviert, es traten einzelne Spindeln auf. Die Tiere mit Narben im Isocortex zeigten im langsamen Schlaf seltene Paroxysmen. Während der häufigeren kurzen Phasen des paradoxen Schlafes war eine Fokalisierung der Spitzen im Bereich der Läsion nachweisbar, jedoch, keine Aktivierung. Bei allen Tieren war die ausgeprägteste Aktivierung der Krampfbereitschft stets in dem von uns als „Wach mit motorischer Inaktivität“ bezeichnete Phase zu bemerken. Daher wird angenommen, daß dieser Zustand bei der Katze mit dem Einschlafstadium des Menschen vergleichbar ist.
    Notes: Summary The activation of focal epileptic activities during wakefulness, slow and REM sleep was studied in chronic experiments in 20 epileptic cats (Kopeloff's method). The lesions were produced in the nucleus amygdaloideus (pars basolateralis), hippocampus dorsalis, formatio reticularis mesencephali and in the isocortex. Each animal was observed from between 3 to 60 days and a total of 442 hours of polygraphy (E.E.G., E.M.G, Eye movements) were recorded. Within the first 7 days all animals showed E.E.G paroxysms and most of them showed seizures from the beginning of the second week. In those cats with subcortical lesions there was no change detected in the duration, distribution and organisation of the different sleep phases. The paroxysmal E.E.G activity seen in the wakeful animal were not activated or focalised during slow-wave sleep; in REM sleep the paroxysms disappeared completely, only a few spindles were seen. Animals with lesions in the isocortex rarely showed paroxysms during the slow wave sleep. However, during REM sleep a clear focalisation was seen, although there was no additional activation in the area of the lesion. In all animals the most significant of the paroxysms was seen during a state which we should like to describe as; “Awake without any motor activity”. It is assumed that this state corresponds to the state of falling asleep in man.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00344411
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Einfluß von Insulin auf das Membranpotential bei alimentärem Kaliummangel (1968)
    Springer
    Pflügers Archiv 301 (1968), S. 254-258 
    Details
    ISSN: 1432-2013
    Keywords: Insulin ; Potassium Deficiency ; Membrane Potential ; Rat Diaphragm ; Insulin ; Kaliummangel ; Membranpotential ; Rattenzwerchfell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 102 Zellen des Zwerchfells von insgesamt 7 Ratten mit alimentärem Kaliummangel fanden wir unter dem Einfluß von Insulin (0,1 I.E./ml) eine Depolarisation um 11,2 mV, nämlich von −94,6 (s=±6,4) mV bei insgesamt 100 Zellen auf −83,4 (s=±6,8)mV (p 〈 0,001). Die Kaliumkonzentration in der Inkubationslösung betrug 4,7 (s=±0,29) mval/l. — Ferner steigt die bei kaliumverarmten Tieren erniedrigte intracelluläre Kaliumkonzentration unter Insulineinfluß von 107 (s=±12) mval/lH2O IZR auf 130 (s=±19,8) mval/lH2O IZR an (p〈0,05). Die Befunde sprechen dafür, daß Insulin bei kaliumverarmten Tieren einen Netto-Kaliumeinstrom bewirkt, der eine Abnahme des Membranpotentials zur Folge hat.
    Notes: Summary In 102 single muscle cells of 7 rats with alimentary potassium depletion we found under influence of insulin (0.1 I.U./ml) a depolarisation of 11.2 mV, i.e. from −94.6 (s=±6.4)mV (100 cells) to −83.4 (s=±6.8)mV (p〈0.001). The potassium concentration in the incubation medium was 4.7 (s=±0.29) mequ/l. — In addition we measured under influence of insulin (0.1 I.U./ml) an intracellular potassium concentration of 130 mval/lH2O IZR, which is probably higher than in potassium deficient animals without insulin (p〈0.05). These findings suggest that insulin produces a netto potassium influx in potassium deficient animals, which could explain the depolarisation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00363772
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    The inhibition of the sarcoplasmic calcium pump by prenylamine, reserpine, chlorpromazine and imipramine (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 260 (1968), S. 444-455 
    Details
    ISSN: 1432-1912
    Keywords: Chlorpromazin ; Calcium ; Zellmembran ; Muskelproteine ; Chlorpromazine ; Calcium ; Cell Membrane ; Muscle Proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary 1. The calcium induced increase in ATPase and the rate of calcium uptake of the vesicular fragments of sarcoplasmic reticulum isolated from rabbit skeletal muscle are reduced by reserpine, prenylamine, chlorpromazine and imipramine. 3×10−5M reserpine, prenylamine, chlorpromazine and ∼3×10−4M imipramine are required to produce 50% inhibition of both activities. 2. In the presence of the drugs the rate of calcium exchange at the cessation of calcium uptake is reduced to the same extent as the initial rate of calcium uptake. 3. Neither the calcium storing capacity nor the ability to concentrate calcium are impaired by the drugs. 4. The drugs do not affect the calcium dependent phosphate exchange between ATP and ADP and the calcium dependent formation of phosphoprotein.
    Notes: Zusammenfassung 1. Reserpin, Prenylamin, Chlorpromazin und Imipramin hemmen sowohl die Geschwindigkeit der Calcium-Aufnahme als auch die der Calcium-induzierten Extra-ATP-Spaltung an isolierten Vesikelmembranen des sarkoplasmatischen Reticulums von quergestreifter Muskulatur des Kaninchens. Die für eine 50%ige Hemmung erforderlichen Konzentrationen betragen beim Reserpin, Prenylamin und Chlorpromazin 3×10−5M, beim Impiramin ∼3×10−4M. 2. Calcium-Efflux und -Influx werden durch die Pharmaka in gleichem Ausmaß gehemmt. 3. Das Konzentrationsvermögen der Vesikel für Calcium wird deshalb durch die Hemmstoffe nicht beeinflußt. 4. Der erste Reaktionsschritt des aktiven Calciumtransports der Vesikel — die Übertragung des Phosphates des ATP auf das Vesikelprotein — wird durch die Pharmaka nicht beeinflußt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00537359
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Vermehrte Bildung von Bilirubinglucuronid in der Leber während der Insulin-und Sulfonylharnstoff-Hypoglykämie (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 260 (1968), S. 254-268 
    Details
    ISSN: 1432-1912
    Keywords: Bilirubin ; Glucuronates ; Insulin ; Liver ; Tolbutamide ; Bilirubin ; Glucuronidsynthese ; Insulin ; Leber ; Tolbutamid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Lebergewebe von Ratten, die mit Tolbutamid, mit anderen blutzuckerwirksamen Sulfonylharnstoffderivaten oder mit Insulin behandelt worden waren, bildet bei Inkubation in vitro mehr Bilirubinglucuronid als das Gewebe unbehandelter Kontrolltiere. Dieser Effekt wurde 2 Std nach der intraperitonealen Injektion der blutzuckersenkenden Stoffe nachgewiesen, er tritt dosisabhängig auf und ist mit der blutzuckersenkenden Wirkung gut korreliert. Ein dem Tolbutamid chemisch verwandtes, jedoch blutzuckerunwirksames Methylsulfonylharnstoffderivat hatte diese Wirkung nicht. Die Steigerung der Glucuronidsynthese ist dadurch bedingt, daß in der Leberzelle während einer Insulin- oder Sulfonylharnstoffhypoglykämie vermehrt aktivierte Glucuronsäure (UDPGA) für die Konjugation bereitgestellt wird. Die Aktivität des für die Konjugationsreaktion verantwortlichen Enzyms, der UDP-Glucuronyltransferase, war unter unseren Versuchsbedingungen nicht verändert. Es fanden sich keine Anhaltspunkte dafür, daß in der Insulin- oder Sulfonylharnstoffhypoglykämie die Bildung von UDPGA aus UDPG beschleunigt erfolgt. Die Aktivität der UDPG-Dehydrogenase war nicht verändert, auch Faktoren, die eine Bildung von UDPGA begünstigen könnten, wie ein erhöhter NAD+/NADH-Quotient und eine gesteigerte ATP-Konzentration im Gewebe, waren nach Tolbutamid nicht nachzuweisen.
    Notes: Summary Liver tissue of rats pretreated with tolbutamide, with other hypoglycaemic sulfonylurea compounds, or with insulin formed more bilirubinglucuronide when incubated in vitro than the tissue of untreated controls. The effect was present two hours after the blood sugar lowering agents had been injected intraperitoneally. It was dose-dependent and well correlated to the hypoglycaemic response. A methylated sulfonylurea compound, which is chemically closely related to tolbutamide but devoid of blood sugar lowering activity failed to show this effect. Glucuronide formation in hypoglycaemia induced by insulin or tolbutamide is increased as more activated glucuronic acid (UDPGA) is made available to the conjugation reaction. There was no change in the activity of the enzyme responsible for glucuronide synthesis, the UDP-glucuronyl-transferase, in our experiments. There was no indication that the formation of UDPGA from UDPG was accelerated by insulin or sulfonylureas. There was no change in the activity of the hepatic UDPG-dehydrogenase. Factors which could favour the formation of UDPGA such as an increased NAD+/NADH ratio or an elevated ATP concentration in the tissue were not present following tolbutamide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00538037
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    The relation between the chemical structure of local anesthetics and inhibition of calcium-evoked secretion from the adrenal medulla (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 260 (1968), S. 298-308 
    Details
    ISSN: 1432-1912
    Keywords: Anesthetics, Local ; Adrenal Medulla ; Calcium ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Local anesthetics (LA's) were examined for their ability to inhibit medullary catecholamine release from perfused cat adrenal glands in response to calcium (0.5 mM) in the presence of 56 mM KCl. LA's which are esters of p-aminobenzoic acid (including benzocaine), or which possess either an amide group (dibucaine), an amidine group (phenacaine), or an amino alkyl ether linkage (diphenhydramine) all produced a graded inhibition of the action of calcium, which was reversed by excess calcium (3 mM). Benzocaine, which does not possess an alkyl amino nitrogen, was five times more potent than procaine in depressing calciumevoked secretion; benoxinate, as well as tetracaine, which differ from procaine and its dimethyl analogue by possessing substituent groups on the aromatic ring were over thirty times more potent than procaine and dimethyl-procaine. Increasing the pH of the perfusion medium from 7.0–8.3 produced no marked alteration in the ability of procaine, tetracaine, and benzocaine to inhibit the stimulant actions of calcium. It is concluded that the aromatic ring of the LA molecule is more important than the alkyl nitrogen in determining the activity of a given agent in blocking the action of calcium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00537635
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Der Einfluß der Kontraktionsfrequenz auf das Aktionspotential des Meerschweinchen-Papillarmuskels (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 260 (1968), S. 342-365 
    Details
    ISSN: 1432-1912
    Keywords: Myocardium ; Frequency of Contraction ; Action Potential ; Calcium ; Excitation-Contraction Coupling ; Myokard ; Kontraktionsfrequenz ; Aktionspotential ; Calcium ; Elektromechanische Kopplung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of stimulation frequency on the course of the transmembrane action potential (AP) and on the isometric tension of isolated guinea pig papillary muscles has been investigated. Special attention has been paid to the question whether the observed changes can be due to a frequency dependent increase of the extracellular concentration of Ca2+ and K+. The following results have been obtained: 1. The amplitude of the AP decreases at a stimulation frequency above 2/sec due to a diminished membrane-resting-potential (MRP) and a decrease in overshoot. 2. The duration of the AP is influenced biphasically by increasing the stimulation frequency at relatively low external calcium concentrations (1.2 and 2.4 mM). When the frequency of stimulation is increased, starting at 0.125/sec, the AP duration is prolonged at first and then shortened. At frequencies below 0.125/sec (down to 0.004/sec) the AP duration again increases. The prolongation of the AP in the medium frequency range (between 0.125 and 0.5/sec) is minimal at a higher calcium concentration (4.8 mM). The marked shortening of the AP duration caused by an increase in stimulation frequency above 1/sec corresponds to the frequency dependent increase in isometric tension of the papillary muscle. 3. The AP duration is shortened by 70 msec when the stimulation frequency is raised from 1/sec to 5/sec. After switching back to the lower frequency (1/sec) the disappearance of the frequency effect on the duration of the AP starts with a lower and continues with a higher speed than that on the force of contraction, the original values of both parameters being reached at the same time. 4. The extent of the frequency induced change of the AP duration is almost equal at 30%, 60% and 90% repolarisation. Consequently, the duration of the “plateau” (at 30% repolarisation) is shortened relatively more than the AP duration at 90% repolarisation. 5. The AP duration at 90% repolarisation is influenced by Ca2+ and Na+ antagonistically according to the relation [Ca2+]/[Na+]2 in the frequency range between 0.125/sec and 4.0/sec. In contrast, the extent of the shortening of the “relative duration of the plateau” depends on the external sodium concentration ([Na+] e ). The lesser shortening of the “relative duration of the plateau” at a decreased [Na+] e (70 mM instead of 140 mM) corresponds to a decreased positive inotropic frequency effect. 6. The MRP is decreased by 8 mV when the stimulation frequency is increased from 1/sec to 5/sec. Considering the relation between MRP and [K+] e at a stimulation frequency of 1/sec a frequency induced increase of [K+] e from 5.9 mM to 8–9 mM can be assumed. Such an increase in [K+] e , however, only causes a shortening of the AP duration by 6 msec. Concomitantly, the relative duration of the plateau is prolonged. 7. The shortening of the AP duration of about 70 msec due to an increase of the stimulation frequency from 1/sec to 5/sec equals—as does the augmentation of the contractile force of the muscle—the effect of a two—or threefold elevation of the external calcium concentration. Similarly the lengthening of the AP duration by an increase in stimulation frequency from 0.125 to 0.5/sec at a relatively low external calcium concentration (1.2 mM) equals the effect of raising the [Ca2+] e . 8. The results lead to the conclusion that the influence of the frequency of stimulation on the duration of the action potential is caused mainly by an increase of the calcium concentration at the outside of the cell membrane while the decrease of the membrane-resting-potential as well as of the overshoot may be the result of an extracellular accumulation of K+.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00537639
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    The binding of the calcium transport inhibitors reserpine, chlorpromazine and prenylamine to the lipids of the membranes of the sarcoplasmic reticulum (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 260 (1968), S. 456-473 
    Details
    ISSN: 1432-1912
    Keywords: Chlorpromazin ; Calcium ; Zellmembran ; Muskelproteine ; Lipide ; Chlorpromazine ; Calcium ; Cell Membrane ; Muscle Protein ; Lipids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary 1. Reserpine, chlorpromazine, prenylamine and imipramine are bound to vesicles isolated from the sarcoplasmic reticulum of rabbit striated muscle cells as well as by the lipids which can be extracted from the vesicular preparations. 2. At concentrations of 5×10−7 M reserpine, chlorpromazine and prenylamine, drug binding can just be detected. At drug concentrations of 10−4 M the drug uptake amounts to 0.1 μmol per mg vesicular protein, 0.2 μmol drug per mg vesicular lipid and ∼0.4 μmol drug per mg phosphatidylcholine. 3. Drug binding is reversible and temperature independent. 4. Drug binding is not diminished when the phospholipids are hydrolysed by phospholipase A, C or D. 5. Drug binding is abolished by hydrogenation of the isolated lipids as well as of the lipids bound to the membranes. 6. In addition calcium uptake the Ca++ induced increase in ATP breakdown and the phosphate transfer reaction are inhibited when the lipids in the membranes are hydrogenated. 7. The normal ATPase as well as the lipid free proteins myokinase and actin are not affected by hydrogenation.
    Notes: Zusammenfassung 1. Reserpin, Chlorpromazin, Prenylamin und Imipramin werden sowohl von den isolierten Vesikeln des sarkoplasmatischen Reticulums (quergestreifte Muskulatur von Kaninchen) als auch von den aus diesen mit Chloro-form-Methanol (2:1) extrahierten Lipiden gebunden. 2. Bei einer Konzentration von 10−4 M werden Reserpin, Chlorpromazin und Prenylamin von dem intakten Lipoproteinkomplex der Vesikelmembran in Mengen von 0,1 μmol/mg Vesikelprotein, von 0,2 μmol/mg vesikulärem Total-Lipid und von ∼0,4 μmol/mg Phosphatidylcholin (Lecithin) gebunden. Lipidfreies Vesikelprotein hat keine Bindungsfähigkeit. 3. Die Bindung der Pharmaka ist reversibel und temperaturunabhängig. 4. Die Bindungsfähigkeit der Phospholipide ist nicht beeinträchtigt, wenn diese durch Phospholipase A, C oder D hydrolysiert werden. Sie wird jedoch aufgehoben durch Hydrierung der isolierten bzw. der membrangebundenen Lipide. Nach Hydrierung ist auch die Calcium-Aufnahme, die ATP-Extraspaltung und die Phosphatübertragung aufgehoben. 5. Die lipidfreien Proteine Myokinase und Actin werden durch den Hydrierungsvorgang funktionell nicht beeinflußt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00537360
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Forty-seven years of interest in insulin (1968)
    Springer
    Acta diabetologica 5 (1968), S. 279-298 
    Details
    ISSN: 1432-5233
    Keywords: Choline ; Clinical situation (diabetes) ; Glucagon ; Growth hormone ; Heparin ; Histamine ; Insulin ; Insulinemia ; Night vision ; Pro-insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Resume Alors que mon intérêt pour l'insuline a été pratiquement continu depuis déjà sa découverte, il y a eu des périodes pendant lesquelles mon attention s'est concentrée sur la coline, l'histamine et l'héparine. Pendant les années de guerre, les sujets de recherche ont été naturellement très différents. Les points importants dans le développement de l'insuline, du point de vue chimique, ont été sa purification, cristallisation, détermination de la structure et synthèse. Les physiologistes ont été fascinés par les études regardant le point et le mécanisme d'action de l'insuline. On a appris beaucoup quant à l'action sur grand nombre de tissus différents et l'insuline se montra être la principale hormone anabolique. Les développements cliniques ne sont mentionnés que brièvement car mes intérêts personnels de recherche ont été exclusivement expérimentaux.
    Abstract: Resumen Mientras mi interés para insulina fue prácticamente continuo desde su descubrimiento, hubo períodos en que mi atención se concentró sobre colina, histamina y heparina. Durante los años de la guerra, los temas de investigación fueron naturalmente muy diferentes. Los puntos fundamentales en el desarrollo de la insulina desde el punto de vista químico, fueron su purificación, cristalización, determinación de la estructura y síntesis. Los fisiólogos fueron cautivados por los estudios sobre el punto y el mecanismo de acción de la insulina. Mucho se aprendió acerca de la acción sobre muchos tejidos diferentes y la insulina demostró ser la hormona anabólica principal. Los desarrollos clínicos se mencionan sólo brevemente pues mis intereses personales de investigación han sido exclusivamente experimentales.
    Notes: Riassunto Mentre il mio interesse per l'insulina è stato praticamente continuo sin dalla sua scoperta, ci sono stati periodi nei quali la mia attenzione si concentrò sulla colina, istamina ed eparina. Durante gli anni della guerra, i temi di ricerca furono naturalmente molto diversi. I momenti culminanti nello sviluppo dell'insulina, dal punto di vista chimico, furono la sua purificazione, cristallizzazione, determinazione della struttura e sintesi. I fisiologi sono stati affascinati dagli studi circa il punto ed il meccanismo di azione dell'insulina. Molto è stato appreso intorno all'azione su molti tessuti differenti e l'insulina dimostrò di essere l'ormone anabolico principale. Gli sviluppi clinici sono menzionati solo brevemente poichè i miei personali interessi di ricerca sono stati esclusivamente sperimentali.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01564423
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Determination of the125J-insulin-plasma complex by gel filtration (1968)
    Springer
    Acta diabetologica 5 (1968), S. 347-363 
    Details
    ISSN: 1432-5233
    Keywords: Diabetes mellitus ; Gel-filtration ; Insulin ; 125J-insulin-plasma complex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Resume Les AA. ont étudié la capacité des protéines plasmatiques de lier l'insuline125J avec la méthode de filtration surgel. Le fractionnement parSephadex G-100 a démontré que seulement le 10 % de l'insuline marquée était lié par le protéines plasmatiques des sujets sains, des femmes gravides et des diabétiques non traités. Un pourcentage d'insuline beaucoup plus élevé était liée par les protéines plasmatiques dans des sujets que étaient traités precédemment avec de l'insuline bovine, tandis que le degrée de la liason était tres élevé dans les diabétiques insulino-résistants. De recherches avecSephadex G-200 ont demontré que, après une courte période d'insulinothérapie, le complexe insuline-protéine migrait avec les globulines 19 S. Après une insulinothérapie prolongée et dans les cas insulino-résistants la plus grande partie de l'insuline marquée liée aux protéines était élui avec les globulines 7 S. Le phénomène est attribué à l'action des anticorps anti-insuline bovine.
    Abstract: Resumen La capacidad que poseen las proteínas para ligar la insulina marcada con125J se estudió mediante el método de filtración engel. El fraccionamiento medianteSephadex G-100 demostró que solamente el 10 % de la insulina marcada estaba ligada por las proteínas plasmáticas de sujetos sanos, de mujeres embarazadas y de pacientes diabéticos no tratados. Un porcentaje de insulina notablemente superior estaba ligado por las proteínas plasmáticas en pacientes que anteriormente habían sido tratados con insulina bovina, mientras el grado de enlace se volvía muy elevado en los diabéticos resistentes a la insulina. Experimentos realizados conSephadex G-200 demostraron que después de un breve tratamiento insulínico, el complejo insulina-proteína migraba con las globulinas 19 S. Después de un prolongado tratamiento insulínico y en los casos resistentes a la insulina, la mayor parte de la insulina marcada con las proteínas resultaba eluida con las globulinas 7 S. El fenómeno, discutido detalladamente, se atribuye a la acción de los anticuerpos anti-insulina bovina.
    Notes: Riassunto La capacità delle proteine plasmatiche di legare l'insulina marcata con125J è stata studiata mediante il metodo di filtrazione sugel. Il frazionamento medianteSephadex G-100 ha dimostrato che soltanto il 10% dell'insulina marcata era legato dalle proteine plasmatiche di soggetti sani, di donne gravide e di pazienti diabetici non trattati. Una percentuale di insulina notevolmente superiore era legata dalle proteine plasmatiche in pazienti che erano stati precedentemente trattati con insulina bovina, mentre il grado di legame diveniva molto elevato nei diabetici insulino-resistenti. Esperimenti eseguiti conSephadex G-200 hanno dimostrato che, dopo una breve terapia insulinica, il complesso insulina-proteina migrava con le globuline 19 S. Dopo prolungata terapia insulinica e nei casi insulino-resistenti la maggior parte dell'insulina marcata legata alle proteine era eluita con le globuline 7 S. Il fenomeno, discusso nei particolari, è attribuito all'azione degli anticorpi anti-insulina bovina.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01564427
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Studio degli anticorpi anti-insulina del siero umano in soggetti normali e diabetici (1968)
    Springer
    Acta diabetologica 5 (1968), S. 173-186 
    Details
    ISSN: 1432-5233
    Keywords: Bovine insulin ; Insulin ; Insulin antibodies ; Insulin resistance ; Pork insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Resume Les AA. présentent les résultats obtenus avec une méthode très simple pour la recherche des anticorps anti-insuline, basée sur l'emploi d'insuline I125 ou I131 et sur la précipitation avec alcool absolu du complexe antigène-anticorp. Les anticorps anti-insuline ont été fréquemment observés seulement dans des sujets diabétiques déjà soumis à traitement avec insuline. Un taux élevé d'anticorps anti-insuline s'accompagne à une diminution de la sensibilité à l'insuline (0,1 U/kg i.v.).
    Abstract: Resumen Se expresan los resultados obtenidos con el empleo de un método que puede ser ejecutado en forma my simple, para la investigación de anticuerpos anti-insulina; el método se basa sobre el empleo de insulina I125 o I131; y sobre la precipitación sucesiva con alcohol absoluto del complejo antígeno-anticuerpo. Los anticuerpos anti-insulina han sido hallados con mucha frecuencia solamente en pacientes diabéticos, que recibían tratamiento insulínico. Un título elevado de anticuerpos antiinsulina se asocia a una disminución sensible de la sensibilidad a la insulina (0,1 U/kg i.v.).
    Notes: Riassunto Vengono presentati i risultati ottenuti con l'impiego di una metodica di semplice esecuzione per la ricerca di anticorpi anti-insulina, basata sull'impiego di insulina I125 o I131 e sulla successiva precipitazione con alcool assoluto del complesso antigene-anticorpo. Gli anticorpi anti-insulina sono stati riscontrati con grande frequenza solo in pazienti diabetici già sottoposti a trattamento insulinico. Un elevato titolo di anticorpi anti-insulina si associa ad una diminuzione marcata della sensibilità all'insulina (0,1 U/kg i.v.).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01543866
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Considerazioni sulla proprieta' insulino-legante del siero del soggetto normale e del diabetico mai trattato con insulina (1968)
    Springer
    Acta diabetologica 5 (1968), S. 201-214 
    Details
    ISSN: 1432-5233
    Keywords: Insulin ; Insulin antibodies ; Insulin binding properties of serum ; Insulin therapy ; Serum proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Resume Les AA. ont observé que le sérum d'un sujet normal et celui d'un diabétique, jamais traité avec insuline, ont la possibilité de lier l'insuline dans la même mesure. Dans certains sérums, soit du sujet normal soit du diabétique, est présente une activité de liaison de l'insuline supérieure aux taux normaux plus élevés; cette activité diminue après administration de µU 500 d'insuline bovine. Les AA. présentent leurs considérations à propos de ce phénomène.
    Abstract: Resumen Los AA. observan que los sueros del individuo normal y del diabético nunca tratado con insulina poseen propiedades insulino-ligantes de entidad análoga. En algunos sueros — ya del sujeto normal, ya del diabético — está presente una actividad insulino-ligante superior a los valores máximos normales, que disminuye luego de haber agregado µU 500 de insulina bovina. Los AA. hacen algunas consideraciones interpretativas de tal fenómeno.
    Notes: Riassunto Gli AA. rilevano che i sieri dell'individuo normale e del diabetico mai trattato con insulina sono provvisti di proprietà insulino-legante di entità analoga. In alcuni sieri, sia del soggetto normale che del diabetico, è presente un'attività insulino-legante superiore ai valori massimi normali, che diminuisce dopo aggiunta di µU 500 di insulina bovina. Gli AA. fanno alcune considerazioni interpretative su tale fenomeno.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01543868
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Effects of gut hormone on insulin and glucagon secretion (1968)
    Springer
    Acta diabetologica 5 (1968), S. 499-512 
    Details
    ISSN: 1432-5233
    Keywords: Entero-insular axis ; Gastrin ; Glucagon ; Gut hormones ; Insulin ; Pancreozymin ; Secretin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Resume Des préparations hautement purifiées de gastrine, sécrétine et pancréozymine ont été injectées par voie endoportale chez des chiens anesthésiés, en vue d'examiner les influences possibles des hormones gastro-intestinales sur la sécrétion des îlots de Langerhans. On a vu que les trois hormones provoquent une augmentation immédiate de la concentration d'insuline dans la veine pancréatico-duodénale. L'effet de la gastrine sur la libération d'insuline était insignificant quantitativement, tandis que celui de la sécrétine était plus important et de plus grande durée; cependant la pancréozymine semblait être le stimulant le plus puissant et déterminer en outre une augmentation parallèle de la sécrétion pancréatique de glucagon. On a démontré de plus que la pancréozymine augmentait la réponse tant de l'insuline que du glucagon à l'hyperaminoacidémie. On a observé que l'administration intraduodénale d'acides aminés, qui représente notoirement la stimulation la plus puissante de la pancréozymine endogène, est en mesure de déterminer une libération plus grande et plus rapide d'insuline et de glucagon par rapport à l'administration intraveineuse d'acides aminés, ce qui fait supposer que la pancréozymine endogène joue un rôle physiologique lorsque la réponse de l'hormone des cellules insulaires aux acides aminés ingérés est augmentée. Le facteur physiologique qui augmente la réponse insulaire au glucose ingéré reste toutefois inconnu.
    Abstract: Resumen Medicamentos altamente purificados de gastrina, secretina y pancreozimina han sido inyectados por via intraportal a perros anestesiados, con el fin de examinar las posibles influencias de las hormonas gastro-intestinales sobre la secreción de las hormonas de las islas de Langerhans. Se ha notado que las tres hormonas producen aumento inmediato de la concentración de insulina en la vena pancreática-duodenal. El efecto de la gastrina sobre la liberación de insulina era insignificante cuantitativamente, mientras el de la secretina era apreciable y de mayor duración; sin embargo, parecía que la pancreozimina fuese el estimulante más potente y que además determinava aumento paralelo de la secreción pancreática de glucagón. Además se ha demostrado que la pancreozimina aumentava la respuesta, ya de la insulina, ya del glucagón, a la hiperaminoacidemia. La administración intraduodenal de aminoácidos, que representa notoriamente el más potente estímulo de la pancreozimina endógena, está en grado de provocar una liberación mayor y más rápida de insulina y glucagón, que la administración intravenosa de aminoácidos; cosa que hace pensar que la pancreozimina endógena ejerce un papel fisiológico cuando aumenta la respuesta de la hormona de las células de las islas a los aminoácidos ingeridos. Sin embargo, el factor fisiológico que aumenta la respuesta insular a la glucosa ingerida, queda desconocido.
    Notes: Riassunto Preparati altamente purificati di gastrina, secretina e pancreozimina sono stati iniettati per via endoportale in cani anestetizzati, allo scopo di esaminare le possibili influenze degli ormoni gastro-intestinali sulla secrezione degli ormoni delle isole di Langerhans. Si è riscontrato che tutti e tre gli ormoni provocano un immediato aumento della concentrazione di insulina nella vena pancreatico-duodenale. L'effetto della gastrina sulla liberazione di insulina era quantitativamente insignificante, mentre quello della secretina era più rilevante e di maggiore durata; tuttavia sembrava che la pancreozimina fosse il più potente stimolatore e che inoltre determinasse un aumento parallelo della secrezione pancreatica di glucagone. Per di più si è dimostrato che la pancreozimina aumentava la risposta sia dell'insulina che del glucagone alla iperaminoacidemia. La somministrazione intraduodenale di aminoacidi, che rappresenta notoriamente la più potente stimolazione della pancreozimina endogena, è stata riscontrata in grado di determinare una liberazione maggiore e più rapida di insulina e di glucagone rispetto alla somministrazione endovenosa di aminoacidi, il che fa pensare che la pancreozimina endogena svolga un ruolo fisiologico nell'aumentare la risposta dell'ormone delle cellule insulari agli aminoacidi ingeriti. Tuttavia il fattore fisiologico che aumenta la risposta insulare al glucosio ingerito rimane sconosciuto.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01545355
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Die Beeinflussung der Insulinhypoglykämie durch Xylit (1968)
    Springer
    Clinical and experimental medicine 148 (1968), S. 22-27 
    Details
    ISSN: 1591-9528
    Keywords: Insulin ; Hypoglycemia ; Xylitol ; Insulin ; Hypoglykämie ; Xylit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei Kaninchen, Meerschweinchen, Mäusen und Ratten wurde der Einfluß von Xylit auf die Insulinhypoglykämie untersucht. Es zeigte sich, daß Xylit die durch große intravenöse Insulindosen hervorgerufenen neurogenen Störungen (Lähmungserscheinungen, Krämpfe) zu beseitigen bzw. zu verhüten vermag. Gleichzeitig kommt es zu einem Wiederanstieg der Glucosekonzentration im Blut. Die möglichen Mechanismen dieser Wirkung werden diskutiert.
    Notes: Summary The influence of xylitol on insulin-induced hypoglycemia was studied in rabbits, guinea pigs, mice, and rats. Relief of hypoglycemia and the concomitant disturbances of the nervous system was observed following the injection of xylitol. The possible mechanisms of this action are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02044623
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Molecular weights and molecular weight distribution of polymers by equilibrium ultracentrifugation. Part I. Average molecular weights (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 91-109 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: From the sedimentation-diffusion equilibria of some polymer solutions the average molecular weights M̄n, M̄w, M̄z, and M̄z+1 have been determined in different ways. In particular, the applicability of Fujita's method, which utilizes concentration gradient values at the midpoint of the solution column at a number of rotor speeds, was examined. It appears that if the gradients at some other places in the column are also used, a smaller range of rotor speeds suffices. This method is generally applicable for determining the average molecular weights specified above.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Stress relaxation of monodisperse poly-α-methylstyrene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 129-140 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The viscoelastic properties of monodisperse poly-α-methylstyrenes of molecular weights of 4 × 104 to 50 × 104 were studied by the tensile stress-relaxation method. The relaxation-time spectra as well as the steady-flow viscosity, the steady-state compliance, the maximum relaxation time, and the modulus associated with the maximum relaxation time were determined. The molecular weight dependences of these quantities were compared with the theory of Rouse and Bueche as modified by Ferry, Landel, and Williams, as well as with data on other polymers reported in the literature.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Effect of morphology in the surface region of polymers on adhesion and adhesive joint strength (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 231-240 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The morphological character of the surface region of polyethylene has been considered with respect to adhesion and adhesive joint strength. By melting polyethylene onto a high-energy surface (e.g., aluminum) we have provided for extensive nucleation and the formation of a transcrystalline region in the polymer. Dissolution of the metal rather than peeling the metal from the polymer leaves the surface region of the polymer intact. The polymer sheet is now amenable to conventional adhesive bonding and forms a strong adhesive joint. We conclude from this study that the occurrence of the normal weak boundary layer is a consequence of the morphology of the surface region of the material and is, therefore, influenced by the method of preparation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    NMR studies of chlorinated poly(vinyl chloride) and polybutadieneA preliminary report of this work was presented at the 15th Annual Meeting of the Society of Polymer Science of Japan held in Nagoya, May 1966. (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 223-230 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Molecular structures of chlorinated poly(vinyl chloride) and polybutadiene have been studied by high resolution NMR. The spectra of the chlorinated polymers give broad signals. New peaks appear in the lower fields of the —CH2— and —CHCl— groups with increasing chlorine content. The chlorination of poly(vinyl chloride) takes place predominantly on —CH2— rather than on —CHCl—, e.g., a 70% chlorinated polymer has about 10 mole-% of —CCl2— groups. Polybutadiene reacts first with chlorine by addition to give a head-to-head poly(vinyl chloride), and then the substitution of the hydrogen atom takes place. Chlorinated polybutadiene with 70% Cl has about 18 mole-% of —CCl2—. The multiplets characteristic of spin-spin couplings in the spectrum of the original poly(vinyl chloride) are still observed in that of the highly chlorinated product. This fact shows that a considerable number of poly(vinyl chloride) sequences of certain lengths persist in the highly chlorinated polymer.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060112
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Determination of orientation of the crystalline and amorphous phases in polyethylene by X-ray diffraction (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 281-288 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: For polyethylene fibers, orientation parameters of the form 〈cos2 φ〉 were calculated from traces obtained with an x-ray diffractometer equipped with an orientation integrator. The angle φ is that which a crystal or molecular axis makes with the fiber axis. Traces over a continuous range of diffraction angle were obtained for (2/π)Iav, and also the weighted averages (2/π)Iav 〈cos2φ〉 and (2/π)Iav 〈sin2φ〉, where Iav is the intensity averaged over all orientations. The orientation for the crystal a, b, and c axes were determined from area measurements of the {110} and {200} lines, and the orientation parameter for the molecular axis in the amorphous phase was determined from area measurements of the amorphous halos. An undrawn fiber showed a slight a and c axis orientation along the fiber axis, and a slight transverse orientation of the b axis and the molecular axis. For a highly drawn fiber the orientation parameter for the c axis was 0.98 and for the molecular axis 0.65. The degree of crystallinity, measured from the (2/π)Iav versus 2θ traces, were 66.1% and 73.3% for the undrawn and drawn fiber, respectively.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Stress-strain behavior of elastic materials. O. H. Varga. Interscience, New York, 1966. 190 pp. $11.00 (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 301-301 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060121
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Polymer fractionation. II. The analytical problem (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 383-406 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Complete fractionations into 5, 10, and 20 fractions were calculated by a numerical method based on the Flory-Huggins theory in order to evaluate various procedures for determining the molecular weight distribution from fractionation data. If the initial distributions are wide, the differential distribution cannot be accurately reconstructed, not even if each fraction is characterized by two average molecular weights (instead of one, as is customary). In addition to this inadequacy in the evaluation procedure there are the experimental errors which further detract from the accuracy of the result. The integral distribution can, in some cases, be approximated fairly well by means of the Schulz method, provided that the polymer is separated into many fractions with narrow distributions. However, the integral distribution thus obtained does not reflect details in the differential distribution. Polymer fractionation does not appear to be a suitable procedure for accurate determination of the differential distribution. From the assembled material, a thermodynamic method has been derived which seems to hold out better prospects. It should enable the differential distribution to be directly determined from a detailed analysis of the liquid-liquid phase relationships, provided the free energy of mixing function of the system is known.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Single crystals of polyethylene produced by γ-radiation-induced polymerization (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 289-293 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060119
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Electronic and ionic conductivity in nylon 66Presented in part at the 152md American Chemical Society Meeting, New York City, September 1966. (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 463-477 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The conductivity of dry poly(hexamethylene adipamide) (nylon 66) was measured as a function of time and temperature. Three temperature ranges were observed in which the time dependence of conductivity differed: (a) below 80°C. the conductivity decreased continuously with time; (b) between 80°C. and 110°C. the conductivity remained constant over long periods; (c) above 120°C. a continuous decrease in conductivity was again observed. In other experiments the volume of gas evolved from the nylon film was measured under continuous potential and compared with the total current passed through the sample. It was observed that above 120°C. the gas evolved corresponded to about one-half the volume calculated if the conduction process involved only protons. Below 120°C. the gas evolved corresponded to an increasingly small fraction of the total current until below 90°C. no evolution of gas was observed. This suggests that at temperatures above 120°C. conduction involves the transport of both protons and electrons, whereas at lower temperatures it is electronic. Mechanisms of conduction are discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060304
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Identification of a stereoblock poly(methyl methacrylate) sample with a stereocomplex (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 509-516 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Acid hydrolysis of a stereoblock poly(methyl methacrylate) sample leads to a mixture of isotactic and syndiotactic poly(methacrylic acid) which can be separated by electrophoresis. The experiment confirms the stereochemical identity between the so-called “stereoblock” poly(methyl methacrylate) and the stereocomplex which syndiotactic and isotactic poly(methyl methacrylate) form in the ratio 2:1. A possible mechanism of replica polymerization is suggested to account for this effect.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060308
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Electrical conduction in olefin oxide polymers (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 407-420 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The electrical conductivities in vacuo of poly(ethylene oxide) and two higher olefin oxide polymers have been found to be ∼9 orders higher than for other saturated organic polymers. The possibility of ionic transport resulting from the presence of impurities (including water) has been eliminated, and it is proposed that an inherent ionic process is operative, involving the generation of protons and then subsequent transport by a handing-on process. The two general requirements are the presence of proton-accepting atoms (in this case oxygen) in the polymer chains; and proximity to the melting point to ensure adequate chain-mobility. These requirements are met by poly(ethylene oxide), poly(trimethylene oxide), and poly(tetramethylene oxide), which are all close to their melting points at room temperature. poly(methylene oxide), with a melting point of ∼180°C., on the other hand, has the low conductivity of a typical insulator.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060206
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Low-temperature dispersion related to methylene units of a polymer main chain (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 457-462 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polymers containing dynamically isolated polymethylene segments of various lengths were obtained from the reaction of bisphenol-A-diglycidyl ether with α,ω-diamines. On the basis of the mechanical damping data of these polymers, it was established that the shortest polymethylene segment to show the -125°C. γ dispersion, characteristic of polyethylene, must consist of at least five carbon atoms.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Influence of microstructure on the hydrodynamic behavior of poly-α-methylstyrene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 499-508 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The theta temperature of poly-α-methylstyrene in cyclohexane has been found to vary with the stereostructure of the polymer. The observed values range from 305.5°K. for highly syndiotactic material (0.95 syndiotactic diads) to 310.0°K. for anio ically polymerized samples (0.67 syndiotactic diads). Results indicate that the unperturbed dimensions of the polymer increase with increasing isotacticity of the chain, whereas the entropy parameter ψ1, measured in cyclohexane, decreased as the structure became more isotactic. Measurements of the second virial coefficient in toluene showed an increasing interaction with the solvent as the polymer became more syndiotactic.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060307
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Damped torsional oscillator model for polymer molecules (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1177-1182 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: At present the widely used model for explaining viscoelastic and dielectric properties of polymer solutions is that of Rouse and Bueche. Here the polymer molecule is considered as an array of Gaussian subunits, each of which acts as an entropy spring. The motion of these segments is damped by the viscous drag of the surrounding solvent (RB model). An alternative model is presented, in which the segments are torsional oscillators consisting of two or three backbone links, and the damping is due to hindered internal rotation (DTO model). The mathematical treatment of these two models is essentially identical, but the physical interpretation of the constants used is very different. The DTO model has previously been applied by one of us to the interpretation of viscoelastic data. It is here applied to the interpretation of dielectric loss data. It is shown that dielectric measurements in dilute solution should very readily discriminate between the two approaches. Finally it is shown that the relaxation time computed from the DTO model is in closer agreement with published NMR data on poly(propylene oxide) 2025, than is the RB relaxation time. The postulates of the DTO model appear to be confirmed for this low molecular weight polymer. An even more sensitive distinction should be available by studies of the relaxation time as a function of polymer concentration.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060610
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Graphical representation of polarized infrared absorption data for biaxially oriented polymers (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1203-1206 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060612
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Hydrogen bonding in butadiene copolymers. I. Network formation (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 895-911 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The incorporation of comonomers bearing functional groups yields butadiene copolymers capable of hydrogen bonding. Three such butadiene-based materials were studied: methacrylic acid copolymers, 2-methyl-5-vinylpyridine copolymers, and stoichiometric mixtures of the acidic and basic copolymers. The elastic effects of intermolecular hydrogen bonding were determined by comparing the simple weighted average of the moduli of the parent copolymers with the observed modulus of their stoichiometric mixture. The results show that measurable increases in the moduli of the mixtures persist even above the glass temperature Tg, which is itself elevated in the mixtures. These increases may be treated as temperature-dependent temporary crosslinks.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060509
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Studies of solution properties of copolymers. II. Copolymer of maleic anhydride and styrenePresented at the 19th Annual Meeting of the Chemical Society of Japan, Hiyoshi, Kanagawa, April, 1966. (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 665-673 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Styrene and maleic anhydride were copolymerized in benzene. The whole polymer thus obtained was fractionated with acetone and petroleum ether as the solvent and precipitant, respectively. The viscosities and osmotic pressures of the fractions were determined in tetrahydrofuran. The relation between the intrinsic viscosity and the molecular weight, [η] = 5.07 × 10-5 M̄n0.81, was obtained in tetrahydrofuran. The unperturbed mean square end-to-end distance was estimated by the Stockmayer-Fixman equation. A theoretical equation for the mean square end-to-end distance for a chain of repeating units of different bond lengths a and b with a fixed valence angle θ and without restriction of internal rotation was presented and applied to this copolymer. In addition, the equation of the mean-square end-to-end distance derived by Wall for trans-polyisoprene without rotational restriction was modified for application to this copolymer. The result evaluated with our equation was about 26% smaller than that from the modified Wall equation. A steric parameter for the present copolymer is defined and discussed in comparison with those of polystyrenesulfone and polystyrene.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Anisotropy of viscoelastic transitions in oriented polyethylenes (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1083-1091 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Measurements have been made of the anisotropy of viscoelastic behavior in cold-drawn low-density and high-density polyethylene sheets. In the low-density polymer the β transition was shown to be highly anisotropic, maximum losses corresponding to shear on planes containing the axis of drawing and on planes perpendicular to this axis. In high-density polyethylene the α transition shows anisotropy.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060604
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Thermodynamic properties of poly(2,6-dimethyl-1,4-phenylene ether) (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1141-1148 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The thermodynamic properties of crystalline and amorphous poly(2,6-dimethyl-1,4-phenylene ether) (PPORegistered trademark of General Electric Company. polymer, General Electric Co.) have been studied calorimetrically between 80 and 570°K. The calculated configurational entropy of this polymer, of similar magnitude to other glass-forming liquids, is consistent with the combination of an unusually high ratio of Tg/Tm, and a low melting entropy.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Dynamic analysis of branching in radical polymerizationPaper presented at the 154th Meeting, American Chemical Society, Chicago, September 1967. (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1149-1160 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A method for the theoretical analysis of branching in radical polymerization is presented which includes the dynamics of the process. In particular, the method is applied to a polymerization that occurs by decomposition of initiator, propagation, termination by radical combination, and chain transfer with polymer. By a numerical solution of the kinetic equations (suitably transformed), the time dependence of the number-average degree of polymerization (DP), the weight-average DP, the mean number of branches, and the monomer conversion are obtained. The parameters of the process, that is the rate coefficients and initial concentrations, have the following effects: (1) An increase in the chain transfer coefficient increases the ratio of weight-average to number-average Xw/Xn and the mean number of branches Xb, but does not change the number-average Xn. (2) For a given value of the chain transfer coefficient, a change in the parameters of the process such that Xn increases, causes Xw/Xn and Xb to increase also. (3) Chain transfer with polymer seems to produce relatively few polymer molecules having many branches and a large number of smaller polymer molecules having no branches; consequently, the polymer size (or molecular weight) distribution broadens.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060608
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Effect of x-rays on extended chain crystals of polyoxymethylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 825-831 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Extended chain crystals of polyoxymethylene were irradiated with x-rays of about 105 r./min. An immediate decrease in superheating on melting was noted. After 90 min. of irradiation the melting point level, refractive indices, and density also decreased. After 480 min. the DTA melting peak at a heating rate of 20°C./min. had decreased 25°C., the melting point decreased about 18°C., and the density calculated from refractive indices decreased 0.031 g./cm.-3. These effects are interpreted as indication of chain scission and formation of amorphous defects.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Some rheological properties of molten polypropylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 871-883 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The following measurements were carried out on the melts of two samples of polypropylene, one with a narrow and one with a broad molecular weight distribution: viscosity in steady shear flow, dynamic storage and loss moduli, total normal thrust in cone-and-plate apparatus, and flow birefringence. The validity of various theoretical interrelations between the measured quantities is checked. The influence of molecular weight distribution is qualitatively discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Hydrogen bonding in butadiene copolymers. II. Network relaxation (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 913-919 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mechanical lability of intermolecular hydrogen bonds in stoichiometric mixtures of acidic and basic butadiene copolymers has been studied by both infrared and mechanical methods. Comparison is made between the weight-averaged E(t) and H(τ) spectra of the parent copolymers and those of the mixed copolymers. The results indicate that the maximum contributions of bond-interchange relaxation migrate to shorter times as the concentration of bonding groups increases.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060510
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Ionic bonding in butadiene copolymers. II. Stress relaxation (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 933-946 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mechanical lability of quadrupolar links in cationic and anionic polyelectrolytes and of ion-pair links in mixed polyelectrolytes is investigated in terms of deviations from the WLF viscoelastic theory. The behavior of E(t), log AT, and Evisc indicate that the quadrupolar links do not interchange below the second transition Tt* found in these materials. The blended polyelectrolytes exhibit low yields of the desired ion pair linking and have transitions characteristic of quadrupolar migration of the unreacted polyelectrolytes.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060512
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Structure-property relations of polyimide filmsThis paper was presented at the 153rd Meeting of the American Chemical Society, Miami Beach, Florida, April 1967. [Polymer Preprints, 8, No. 1, 656 (1967)]. (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 953-960 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of well-characterized polyamic acids from pyromellitic dianhydride and 4,4′-diaminodiphenyl ether of systematically varied molecular weight and known molecular weight distribution were chemically converted to polyimide films under regulated conditions. The films were essentially noncrystalline, of moderate orientation, and soluble in concentrated sulfuric acid. The mechanical properties of the films varied sigmoidally with the solution properties of the precursor. Molecular weights were derived for the onset of mechanical strength and limiting property values are given. The relations between film properties and molecular structural parameters suggest that cyclization probably occurs here with little contribution from crosslinking, degradation, or other side reactions which would appreciably alter molecular weight and molecular weight distribution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060514
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Structure of gum arabic and its configuration in solution (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1593-1606 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Gum arabic was found to have an osmotic molecular weight of 250,000, in agreement with earlier determinations. A molecular weight of 365,000 was found by light scattering, somewhat higher than obtained earlier by sedimentation equilibrium analysis but lower than light-scattering values reported by other investigators. The M̄w/Mn ratio, 1.46, is quite low in gum arabic. The angular dependence of light scattering exhibited the upward curvature to be expected of a spherical molecule and a radius of gyration of about 100 A. or less, as estimated from a Zimm plot. Fractionation of the original gum arabic was done by precipitation of a 0.5% solution in aqueous 0.5% NaCl with acetone. Comparison of the curves of viscosity versus molecular weight and the estimated radius of gyration shows that the hydrodynamic volume is less than that of branched dextran of similar molecular weight. The electroviscous effects for gum arabic in aqueous solution were shown by reduced viscosity curves at various acidities and in salt. The degree of dissociation was calculated for each pH level. The minimum intrinsic viscosity was found in 0.04N HCl where the degree of dissociation at pH 1.5 was found to be 0.049. When the acidity was increased, further reduction in viscosity was found to be negligible. Routine determination of the viscosity and molecular weight of the fractions was done in 0.35M NaCl at pH 10 to which 0.25% of the sodium salt of ethylenediaminetetraacetic acid was added as a sequestrant. The intrinsic viscosity in this solvent was nearly as low as in 0.04N HCl. Light-scattering dissymmetries in water and in 0.35M NaCl plus EDTA at pH 10 were similar, 1.13 and 1.09, respectively, which showed that actual expansion of the macroion is not the cause of the large increase in viscosity of gum arabic when the ionic strength of the solvent is reduced. Periodate oxidation of the polymer confirmed the existence of a 1-3-linked backbone of galactose. Subsequent treatment of the oxidized polymer with alkali reduced the osmotic molecular weight to 45,000 but failed to remove oxidized side branches. The oxidized polymer was fractionated by gel permeation chromatography and the intrinsie viscosity-molecular weight relation compared with relations for fractions of the unoxidized polymer and for other branched and crosslinked polymers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060904
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Thermoelastic properties of networks in swelling equilibrium: Poly(vinyl alcohol) (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1051-1063 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The energy component of the stress has been determined for poly(vinyl alcohol) networks in swelling equilibrium with a series of water-ethylene glycol compositions. The data are analyzed by using the equations describing the thermoelasticity of networks in swelling equilibrium. The ratio fe/f of the energy component to the total force, as calculated from these equations, varies systematically with diluent composition but is independent of elongation in a given diluent. For a network crosslinked by terephthalaldehyde, fe/f varied from -0.33 to -0.42 as the diluent composition was changed from pure water to 20% ethylene glycol. Similar effects were found in a network crosslinked by formaldehyde. It is not yet certain whether this effect represents a real solvent dependence of fe/f or a failure of the equation of state to account for the effect of composition changes on the force.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Rapid stress-induced crystallization in natural rubber (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1689-1703 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Stress-induced crystallization in a rapidly stretched natural rubber gum vulcanizate has been studied using thermal techniques to follow the development of crystallinity. A special-purpose analog computer has been assembled and used on-line to process the thermal and mechanical data obtained in high speed tensile testing. Roughly first-order room temperature crystallization kinetics curves were obtained having time constants of 50-60 msec in the range of 400-540% extension. While the rate of this rapid, presumably primary crystallization appears rather insensitive to elongation in this limited range, the extent of crystallization at 400 msec increases smoothly from zero at 340% elongation to around 18% at 540% elongation. It is shown that our high-speed tensile tester can stretch this vulcanizate fast enough that most of the crystallization takes place after extension has been completed. Stress-strain curves obtained at this high rate are compared with those obtained at lower rates where crystallization takes place during the stretching.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061001
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Intrinsic viscosity of polymers of low molecular weight (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1759-1772 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Experimental evidence concerning the dependence of the intrinsic viscosity [η] on molecular weight M in the low molecular weight range (from oligomers to M = 5 × 104) has been collected in a variety of solvents for about ten polymers, i.e., polyethylene, poly(ethylene oxide), poly(propylene oxide), polydimethylsiloxane, polyisobutylene, poly(vinylacetate), poly(methyl methacrylate), polystyrene, poly-α-methylstyrene, and some cellulose derivatives. In theta solvents, the constancy of the ratio [η]Θ/M0.5 extends down to values of M much lower than those predicted by current hydrodynamic theories. In good solvents, and on decreasing M, the polymers examined, with the exception of polyethylene and some cellulose derivatives, show a decrease in the exponent a of the Mark-Houwink equation [η] = KMa. This upward curvature gives rise to the existence of a more or less extended linear region where the equation [η] = K0M0.5 is obeyed. Below the linear range, i.e., for even shorter chains, the exponent a can increase, i.e., polydimethylsiloxane, or decrease below 0.5, i.e., poly(ethylene oxide), depending on the particular chain properties. These different dependences have been discussed in terms of: (a) variations of thermodynamic interactions with molecular weight; (b) variations of conformational characteristics (as for instance the ratio) 〈r02/nl2〉, where 〈r02〉 is the unperturbed mean square end-to-end distance and n is the number of bonds each of length l; (c) hydrodynamic properties of short chains.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061006
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Transition in swollen polymer networks induced by intramolecular condensation (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1209-1216 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is predicted that the net repulsion between the segments of a polymer network and a poor solvent can cause a phase transition marked by a sudden change in the degree of swelling. This is analogous to the “coil-globule” transition recently predicted by Ptitsyn to occur for a macromolecule in solution. The critical conditions for the transition. as well as phase diagrams, are calculated for the gel in free swelling and under uniaxial tension, which facilitates the transition. The transition depends on the gel being formed of chains crosslinked while greatly swollen by a diluent and also having a high degree of crosslinking. It is concluded that it would be difficult to attain the conditions necessary for the transition in the free-swelling case, but that it should be possible for gel under tension.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060701
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Morphology of polypropylene crystals. III. Lamellar crystals of thermally decomposed polypropylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1255-1271 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Morphology and crystal structure of solution-grown and melt-grown crystals of thermally decomposed polypropylene have been studied by electron microscopy and x-ray diffraction. By crystallization from dilute α-chloronaphthalene or carbitol solutions well-defined lamellar crystals about 100-150 A. in thickness are obtained from fractions (number-average molecular weights 1600-2100) of thermally decomposed crystalline polypropylene. The structure is monoclinic as crystallized from very dilute α-chloronaphthalene or carbitol solutions (0.02-0.005 wt.-%). However crystals of the triclinic as well as of the monoclinic forms are precipitated from carbitol solutions of higher concentrations (0.05-1 wt.-%). On the other hand, the separated triclinic form has been obtained from the melt. Crystals of both modifications have similar morphology. In addition, the chain molecules cannot be expected to fold, within the thickness of lamellae in crystals of either modification prepared from the low molecular weight fractions used in this study.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060705
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Poly(1,2-dimethyl-5-vinylpyridinium methyl sulfate). III. Adsorption on a crystalline silica (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 2009-2019 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: With low-shear mixing, a portion of a high molecular weight poly(DMVPMS) is immediately adsorbed, and fairly stable aggregates are formed by the polymer bridging mechanism. The adsorption equilibrium is not established after several weeks because of a very slow liberation of the partly covered surface that is trapped within the aggregates. At a high ionic strength, or when the polymer is degraded to a low molecular weight, the adsorption equilibrium is quickly established because of a weaker bridging in the aggregates. It is proposed that poly(DMVPMS) adsorbs from water in a flattened conformation by an ion exchange mechanism. The saturation level increases and then becomes constant as the ionic strength is increased. Simple electrolytes show a specific effect on the adsorption of poly(DMVPMS) that is analogous to their effect on the interaction of other colloidal particles.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061206
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Optical studies of the stress-induced crystallization of rubber (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1-30 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The low-angle light scattering by films of stretched natural and synthetic rubbers was investigated. Intense Vv scattering is found under conditions when crystallization occurs which is characteristic of the scattering from aggregates of dimensions comparable with the wavelength of visible light. These were identified with the γ fibrils described by Andrews. The dependence of scattering was studied as a function of light polarization direction, orientation direction, elongation, temperature, degree of swelling, type of swelling liquid, and degree of crosslinking. It was concluded that the scattering unit consists of an assembly of crystals with their chain axes parallel to the stretching direction, but (in the case of natural rubber at high elongations) with the fibril axis at a slight angle to the stretching direction. The scattering is not affected much by swelling but is decreased upon increasing the temperature. Upon recooling the scattering returns, but does so over several hours, indicating that much of the scattering arises from secondary crystallization.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Statistical thermodynamics of polymer solutions. VI. Comblike branched molecules with branches placed randomly along the backbone (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 63-89 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Thermodynamic interactions between arbitrarily branched flexible “comb” molecules (with branches of uniform length affixed to backbones of uniform length but with the number of branches on a molecule and their placement arbitrary) are treated by Zimm's perturbation method to obtain results valid to the double contact approximation. Thus, bimolecular cluster configurations with one and two intermolecular contacts, but not more, are correctly accounted for. This general result is applied to “random” combs (with the number of branches per comb uniform, but the placement random) and to “heterogeneous” combs (with both the number of branches on a molecule and their placement random). Results for the random combs are very similar to those reported earlier for “symmetrical” combs (with f uniform branches disposed at points along the backbone chain so as to subdivide it into f + 1 equal sections), but the second virial coefficient for the random model is slightly the larger when the number of branches per chain is small and the fraction of the molecule in the backbone is at least a few per cent. Since random combs are uniform in mass, the osmotic pressure and light-scattering second virial coefficients are alike; but for a system of heterogeneous combs the virial coefficients differ from one another, and from the random comb result, when the mean number of branches f̄ per chain is small and they are of appreciable length in comparison to the backbone. This behavior reflects the heterogeneity in both molecular mass and dimensions existing under these circumstances. As f̄ increases and/or the mean fraction of segments in the chain backbone becomes large, coincidence with the random comb result is approached. The double-contact second virial coefficients for both random and heterogeneous combs are obtained in closed analytical expression that are much more easily reduced to numerical results than the expression for symmetrical combs given earlier. These two models also correspond better than the symmetrical combs to materials actually obtainable.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    On the possibility of chain folding in solutions of normal paraffins and polyethylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 451-456 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A simple statistical thermodynamic argument is presented in which the probability of intramolecular chain folding of normal paraffins and polyethylene in solution is examined. This possibility is based on the existence of low-energy intramolecular conformations which are stable enough to overcome the tendency of a chain molecule to assume a random arrangement in solution. Some rough estimates of the magnitudes of energetic interaction in straight-chain hydrocarbons are made to demonstrate the plausibility of this hypothesis. The experimental support for this model arises from NMR spectra of normal paraffins in aromatic hydrocarbon solvents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060302
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Second virial coefficient of polymers in good solvents: The case of polyelectrolytes (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1227-1240 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A stepwise segment-by-segment cluster development of the interaction energy of two polymer coils at given distance leads to a closed expression, describing the second virial coefficient A2 in terms of certain intersegmental contact probabilities. An approximate expression for A2(α,z) in good solvents is then derived by using the uniform segment cloud model; the result being equivalent to that obtained by Flory. This expression is combined with the author's theory for α2(z) to give A2(z), and then with a subsequent adaptation of that theory to polyelectrolytes, to derive the dependence of A2 on ionic strength. The α2(z) and A2(z) equations are both compared with recently reported experimental data for NaPSS.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060703
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Thermoluminescence in poly(methyl methacrylate) γ-irradiated at 77°K (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1283-1296 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Isotactic and atactic poly(methyl methacrylate) containing varying amounts of polymerization initiator and chain-transfer additives, and carefully purified radiation-polymerized material, were γ-irradiated in the dark at liquid nitrogen temperature. On warming to room temperature at a near-linear rate of 20°K./min., a glow peak having a maximum luminescence intensity at 162 ± 8°K. was observed in all samples; an additional peak at 239 ± 7°K. was resolved relatively infrequently. Low luminescence yields precluded an investigation of the spectral distribution of the glow peaks. It is shown that the electron traps associated with the lower temperature peak are most probably the main-chain methyl groups, while the higher temperature glow peak is tentatively associated with escape of electrons from structural defects in a few small crystalline regions of the samples. It is postulated that, for the peak at 162°K., the trapped electrons combine radiatively with luminescence centers when thermally induced rotational motion of the main-chain methyl groups permits sufficient wave-function overlap. Assuming that methods of glow curve analysis proposed for inorganic materials are applicable to organics, first-order recombination kinetics and an activation energy of 0.084 ± 0.006 e. v. are deduced for the intensity maximum at 162°K. This activation energy is in fair agreement with that obtained by Bordoni et al. for an unspecified side-chain motion occurring at similar temperatures, but is only about half the values quoted with some reservations by Powles and by Kawai on the basis of NMR experiments. It was not possible to determine the kinetics of the 239°K. peak with certainty, but an activation energy of 0.432 ± 0.085 e. v. follows from a first-order assumption. The additives present in the samples did not appear to play any significant part as electrontrapping agents; this observation contrasts with some recent work on the visible and ultraviolet absorption spectra of the same materials which showed a close correlation of additional bands developed following irradiation with the presence of specific additives.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060707
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Flow-rate dependence of gel permeation chromatography (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1349-1355 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Analysis of polystyrene standards by gel permeation chromatography over a wide range of flow rates revealed two sources of error in volume measurement. These errors arise from solvent evaporation in the siphon chamber and from solvent continuing to flow into the siphon during discharge. Appropriate corrections are discussed, and a vapor feedback loop to eliminate the solvent evaporation error is described. The flow rate dependence of the GPC calibration curve, expressed in the corrected elution volumes, appears different from that reported in the literature. The corrected flow rate dependence of peak elution volumes is in agreement with the expectation of diffusion and exclusion theories.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060711
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Skeletal deformation vibrations and rotational isomerism of methylbutenes and methylpentenes as model compounds of 1,4-polyisoprene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1419-1434 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Infrared spectra of methylbutenes and methylpentenes in the skeletal deformation region have been measured. The force constants for the skeletal deformation vibrations are determined from the frequencies of isobutylene, isobutylene-d6, and methylbutenes. The frequencies of methylpentenes are calculated for the various conformations, and the stable rotational isomers determined. The energy differences between the isomers are determined from the temperature dependence of the spectra. These results are correlated with the conformations of cis-and trans-1,4-polyisoprene chains, and possible conformations are suggested.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060802
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Growth and drawing of polyacrylonitrile crystals grown from solution (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1381-1399 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polyacrylonitrile crystals were grown from dilute solutions of propylene carbonate by a technique similar to that described by Holland et al. Crystals were also grown on various substrates and sampled at various stages of growth after washing away the uncrystallized solution. The initial single lamellae rapidly develop into complex twinned structures with many overgrowths. The morphology of the full-grown crystal varied considerably with crystallization temperature. Small-angle x-ray and electron microscopy results indicate only a small change in lamellar thickness with crystallization temperature for our polymer. Electron and x-ray diffraction results indicate lateral order can be quite good in these crystals. Our x-ray results indicate that the previously reported a and b parameters should be doubled to give a = 21.18 Å and b = 11.60 Å. However, there was no evidence for chain-axis order. The crystals were stretched at various stages of growth on Mylar film. Multilamellar crystals having their long axis parallel to the draw direction formed large cracks perpendicular to the long axis. Fibers of large diameter (100-250 Å) were observed across these cracks. When the long axis of these crystals was at an angle to the draw direction no large cracks or fibers were observed. Single lamellae generally cracked perpendicular to the draw direction, irrespective of their orientation to the draw direction. Definite fibers were not observable across cracks in single lamellae.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060714
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Fast passage dispersion signals in inhomogeneously broadened electron spin resonance spectra: Application to the measurement of the spin-lattice relaxation times of free radicals derived from esters and salts of poly(methacrylic acid) (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1451-1456 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The shape of the first derivative of the dispersion mode of an inhomogeneously broadened electron spin resonance spectrum changes markedly on saturation. This behavior provides a convenient and rapid technique for estimating the spin latice relaxation time of the paramagnetic species involved. The technique is described together with the relevant theory. Values for the relaxation times of free radicals derived from poly(methyl methacrylate) and from poly(sodium methacrylate) have been obtained by this method and are found to be in good agreement with those obtained by the progressive saturation technique. A series of salts of polymethacrylic acid have been γ-irradiated, and the spin lattice relaxation times of the resulting trapped radicals were determined at 77 and 299°K. For a given polymer the relaxation times show little variation with temperature. This is attributed to a broad distribution of correlation times.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060804
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Tensile strength of rubbers (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1561-1566 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A current theory of the tensile strength of rubbers invokes large-scale crosslink interchange at room temperature to explain the high tensile strengths of networks crosslinked with weak linkages. This mechanical lability of certain crosslinks has been assumed from their known thermal lability at higher temperatures. Relaxation of stress experiments at various elongations have been performed at room temperature on networks crosslinked with both weak and strong linkages. Our purpose was to detect mechanically induced crosslink slippage. We have found no evidence of any mechanical lability of weak crosslinks at room temperature. A hypothesis is presented which explains the high tensile strengths of rubbers crosslinked with weak linkages as resulting from an internally relaxed network formed by the thermal lability of the crosslinks at the vulcanization temperature. This theory is shown to be consistent with some previously unexplained experimental results.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060901
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Viscoelastic properties of 1,2-polybutadiene - comparison with natural rubber and other elastomers (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 967-980 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Viscoelastic properties of uncrosslinked 1,2-polybutadiene (91.5% vinyl, 7.0% cis, 1.5% trans, number-average molecular weight 99,000) were studied by dynamic shear measurements between 0.15 and 600 cps (torsion pendulum and Fitzgerald transducer) and shear creep measurements over time periods up to 3.7 × 104 sec., in the temperature rang from 5 to 50°C. More limited dynamic measurements were made on a sample of unvulcanized natural rubber with number-average molecular weight 350,000 at frequencies from 0.4 to 400 cps and temperatures from 13 to 48°C. All data were reduced to 25°C. by shift factors calculated from equations of the WLF form with the following coefficients: 1,2-polybutadiene, c1 = 6.23, c2 = 72.5; natural rubber, c1 = 5.94, c2 = 151.6. In the transition zone, the relative positions of the loss tangent curves on the logarithmic frequency scale for these and other rubbers (1,4-polybutadiene with 50% trans configuration; styrene-butadiene rubber with 23.5% styrene content; and polyisobutylene) provided relative measures of local segment mobility. At 25°C., these ranged over a factor of 3700 with 1,2-polybutadiene and polyisobutylene the lowest and 1,4-polybutadiene the highest. When the frequency scale of each rubber was reduced to a temperature 100°C. above its glass transition temperature, however, the loss tangent curves for all except polyisobutylene were nearly coincident; the latter still showed a lower mobility by a factor of about 1/800. The terminal relaxation time and steady-state compliance for the 1,2-polybutadiene calculated from the Rouse theory were larger than those observed experimentally. The level of compliance corresponding to the entanglement network of 1,2-polybutadiene, JeN, was calculated by integration over the loss compliance, J″, to be 1.62 × 10-7 cm.2/dyne; integration over G″ to obtain the corresponding modulus gave reasonable agreement. From such JeN, values, the average number of chain atoms between entanglement points, jZe, was estimated as follows: 1,2-polybutadiene, 132; natural rubber, 360; 1,4-polybutadiene, 110; styrene-butadiene rubber, 186; polyisobutylene, 320. Values of jZe were also estimated from the minimum in the loss tangent and compared with those reported from the molecular weight dependence of viscosity. The three sources were in generally good agreement.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060516
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Electrical transport through polystyrene films (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1639-1648 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The steady-state current density versus applied electric field characteristics have been measured for two types of polystyrene films. Measurements were made on 1-mil biaxially oriented film and on films produced by casting from solution. The cast films ranged from 5 to 0.5 μ in thickness. The measurements of the steady-state current flowing through the films were done by two different methods. The first was the direct observation of current flowing in a circuit connected to the film which was under a potential stress. The second involved the observation of the decay of a static charge placed on the surface of a film. Both methods are handicapped by the fact that large transient currents flow for extended periods after any change is made in the experimental set up. The results indicate that at 25°C the current increases as the 3.5 power of the applied electric field when the field is greater than 8 × 104 V/cm. At fields less than 8 × 104 V/cm the current decreases more rapidly and tends to become zero.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060909
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Interactions between Co(III) and Ni(II) complex ions and polyelectrolytes (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1093-1100 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An investigation has been carried out of the interaction of optically active tris(ethylenediamine)-Co(III) and of tris(o-phenanthroline)-Ni(II) complex ions with different polyelectrolytes in dilute aqueous solution. Optical rotatory dispersion measurements reveal that binding of the Co(III) complex ions occurs with a noticeable degree of specificity which in addition to depending on the nature of the fixed charges is also affected by the chemical constitution of the polyelectrolytes chain backbones. The dependence of tris(ethylenediamine)-Co(III) optical activity on polyelectrolyte concentration also exhibits interesting features. Polarimetric measurements of the rate of racemization of tris(o-phenanthroline)-Ni(II) ions in the presence of different polyelectrolytes lead to similar conclusions. Sodium dextran sulfate is shown to interact selectively with one of the antipodes of tris(phenanthroline)-Ni(II) complex.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Analysis of the melt viscosity and glass transition of polystyrene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1161-1175 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The melt viscosity, the glass transition, and the effect of pressure on these are analyzed for polystyrene on the basis of the Tammann-Hesse viscosity equation: log η = log A + B/(T - T0). Evidence that the glass transition is an isoviscosity state (log ηg ≃ 13) for lower molecular weight fractions (M 〈 Mc) is reviewed. For a polystyrene fraction of intermediate molecular weight (M ≃ 19,000; tg = 89°C.), it is shown that B is independent of the p-v-T state of the polymer liquid and that dT0/dP = dTg/dP. This is consistent with the postulate that B is determined by the internal barriers to rotation in the isolated polymer chain. Relationships are derived for flow “activation energies” at constant pressure and at constant volume, and for the “activation volume.” Values for polystyrene along the zero-pressure isobar and along the constant viscosity, glasstransition line are reported. For the latter, ΔVg* is constant and corresponds to about 10 styrene units. The “free volume” viscosity equation: log η = log A + b/2.3φ, is reexamined. For polystyrene and polyisobutylene, φg/b = 0.03, but φg and b themselves differ appreciably in these polymers. The parameter b is the product of an equilibrium term Δα and the kinetic term B, and none of these is a “universal” constant for different polymers. The physical significance of the free volume parameter φ, particularly with regard to the “excess” liquid volume, remains undefined. Two new relationships for dTg/dP, one an exact derivation and the other an empirical correlation, are presented.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060609
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Influence of ether oxygen on the temperature position of the low-temperature dispersions of polymethacrylates (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1810-1812 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061011
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Bubble formation in vulcanized rubbers (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1853-1861 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A theoretical treatment is given for the formation of visible holes in an elastic solid. It differs from previous treatments of bubble formation in liquids by neglecting the problem of hole nucleation altogether. Instead, a small spherical hole is assumed to be present initially. The inflation of such a hole by a dissolved gas is then considered. A critical internal pressure is deduced, at which the hypothetical hole would become infinitely large. This pressure is given by 5G/2; where G is the shear modulus of the rubber. Some model experiments are described in which swollen rubber vulcanizates were rapidly heated to bring the dissolved liquid into a superheated conditions. The temperatures of rapid bubble formation were determined for a number of vulcanizates having different degrees of crosslinking and hence different values of shear modulus, and for different swelling liquids. The results are shown to be in reasonably good quantitative agreement with the theoretical predictions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    The “barrer” permeability unit (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1933-1934 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Annealing of polypropylene lamellar crystals (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1938-1942 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Analysis of the random configuration of the polycarbonate of diphenylol-2,2′-propane (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1945-1952 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The structure of the polycarbonate chain has been analyzed from the point of view of the spatial configurations it may assume. The carbonate group is certainly planar, and the trans,trans configuration probably is strongly preferred. Rotations about the aryloxygen bonds are subject to symmetric, twofold potentials. It follows that the molecule can be treated as a freely rotating chain consisting of a succession of virtual bonds 7.0 Å in length, joined at angles of ca. 112°. Calculations carried out on this basis yield 〈r2〉0/M = 0.85 Å2/g-mole wt for the unperturbed random coil, in excellent agreement with the experimental results of Berry, Nomura, and Mayhan. The effect of occurrence of some of the carbonate groups in cis, trans configurations is investigated using more elaborate methods.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061201
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Normal stress effect of molten polyethylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1999-2007 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A brief description is given of a new parallel-plate rheogoniometer for normal stress measurements on polymer melts as functions of the rate of shear. A wire-resistance strain gauge is used as the pressure gauge. Measurements are reported on high-density polyethylene. It is found that the time-temperature superposition principle is applicable to the normal stress data as well as to shear stress in steady flow.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Diffusion coefficients in water vapor-poly(vinyl alcohol) systems. Application of sorption-rate and multifilm-permeation methods (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 2067-2070 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061210
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Infrared study of substrate effects in the surface region of polyethylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1649-1658 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The surface of thin polyethylene films (ca. 1 mil) nucleated on high- and low-energy surfaces was studied. It was found that the degree of crystallinity in the surface region, as determined by transmission and reflection infrared spectroscopy, was dependent on the nature of the substrate. Relatively small and randomly oriented spherulites were observed in the surface region of thin polyethylene films nucleated on gold, a high-energy surface. The surface region of a thin polythylene film nucleated on polytetrafluoroethylene, a low-energy substrate, was observed to have considerably fewer spherulites, but much larger in size, with orientation restricted, in general, to the plane of the film. The relative intensity of the 720 cm-1 to the 730 cm-1 band in the reflectance spectra (ATR) indicates that the surface region of a polyethylene film nucleated on a high surface energy substrate is more crystalline than the surface region of a film nucleated on a low surface energy substrate.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060910
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Significant structures theory of the surface tension of polyethylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1686-1688 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060914
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Variation of crystallite orientation with degree of crystallinity: Isotactic polystyrene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1733-1745 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The orientation of the crystallographic c axis (chain axis) was followed by x-ray diffraction during the crystallization of four samples of isotactic polystyrene differing in elongation ratio. The crystallite orientation can be expressed by 〈cos2 χc〉, where χc is the angle between the c axis and the stretching direction. The degrees of crystallinity w were estimated from the diffraction data by using density for calibration. It was found that 〈cos2 χc〉 decreases in a linear manner with crystallinity, the rate of decrease being very small when the elongation ratio α is 5, but becoming progressively larger as α is decreased toward unity. A qualitative measure suggests that amorphous orientation decreases during crystallization at a rate which is nearly independent of α. The variation of 〈cos2 χc〉 with w is therefore governed by the orientation of the statistical chain segments prior to crystallization. If the elongation ratio is small, the supply of well oriented statistical segments is limited, and 〈cos2 χc〉 will decrease at a rapid rate during crystallization. A treatment due to Krigbaum and Roe permits evaluation of the ratio, ν/N, where ν and N are the average numbers of statistical segments in the crystallization nucleus of critical size, and in a network chain, respectively. Our polystyrene samples were not crosslinked, so chain entanglements must serve as junction points. Values of ν could not be obtained, since N was unknown. However, the (ν/N) ratio for isotactic polystyrene decreases slowly with α, and the values agree reasonably well with those obtained in a previous study of oriented polychloroprene networks. After nearly complete crystallization (ω ca. 0.30), the long period spacing measured by low angle diffraction was approximately 135 Å, and varied only slightly with elongation ratio in the range α = 1 to 5. It therefore appears that chain folded lamellae are present in both drawn and undrawn samples of isotactic polystyrene.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061004
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Some studies of the crystallization of polychlorotrifluoroethylene copolymer films (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 31-61 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A fluorocarbon copolymer of chlorotrifluoroethylene (96%) and vinylidene fluoride has been isothermally crystallized and the quenched films analyzed by the light microscope, photographic light-scattering, and density measurements. Above a supercooling of 79°C., homogeneous nucleation dominates, giving a morphology that appears to be that of a twisted ribbon. At supercoolings below 79°C., heterogeneous nucleation dominates and leads to spherulitic morphology. Sheaf or rodlike morphology occurs at very low supercoolings. Crystallization rates determined from density measurements at room temperature indicate maximum rate due to heterogeneous nucleation occurring at a supercooling greater than 79°C., but the temperature for maximum rate cannot be identified because of the transition to homogeneous nucleation which causes a discontinuity in the rate versus temperature curve. Superposability of crystallization isotherms constructed from density values are inconsistent with the large melting point lowering from that of polychlorotrifluoroethylene for this copolymer. However, this may be explained by the presence of a different crystal system for each monomer in the copolymer.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Temperature dependence of the growth rate of spherulites (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 165-180 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The spherulitic growth data that exist in the literature for a wide diversity of polymers have been analyzed according to various possible nucleation mechanisms. It is demonstrated that, if allowed a reasonable choice for the equilibrium melting temperature, no unbiased selection of a unique nucleation process can be made. Moreover, a set of universal parameters exists for each of the allowable nucleation processes which enables the data to be represented by a single straight line which encompasses all the polymers. The only quantities specific to a given polymer are the equilibrium melting temperature and the activation energy for transport. The magnitude of the latter quantity is shown to be dependent on the glass temperature of the polymer.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Transition temperatures and crystallinity in polyoctadecene-1 (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 241-248 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polyoctadecene-1, as isolated from a Ziegler-type polymerization, was examined by density and refractive index measurements and by differential thermal analysis. Two main transitions were observed, their sharpness suggesting that they are both first-order. Extraction with n-hexane at 25°C. separated the polymer into two almost equal fractions, each showing essentially one of these transitions. Transition temperatures were compared with those of certain other polymers having long n-alkyl side chains. From this comparison, and from the findings of other workers, it was concluded that the polymer of lower transition temperature is atactic polyoctadecene, in which the side chains only participate in crystallization, whereas the polymer of higher transition temperature is tactic polyoctadecene, in which crystallization involves both the main chain and side chains.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Kinetic interpretation of the glass transition: Glass temperatures of n-alkane liquids and polyethylene (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 249-257 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: On the basis of an isoviscosity criterion for the glass transition (ηg ⋍ 1013 poise) in liquids of low molecular weight, theoretical Tg values were calculated for the n-alkane series by the equation log η = log A + B/(T - T0), with the use of values reported by Lewis for the parameters. The Tg/T0 ratio reaches a limiting value of 1.25 and φg = (Tg - T0)/2.3B = 0.027, a constant. Extrapolation to (CH2)∞ gives Tg = 200°K., T0 = 160°K., and B = 640°K. This Tg is consistent with other estimates for poly-ethylene, and T0 coincides with the temperature at which the “excess” liquid entropy for (CH2)∞ becomes zero from thermodynamic data. For polymer liquids it is proposed that E0 = 2.3RB is determined by the internal barriers to rotation for the “isolated” polymer chains. Thus, E0 = 2.9 kcal./mole for polyethylene, 3.0 kcal./mole for polystyrene, 5.7 kcal./mole for polyisobutylene, and 1.9 kcal./mole for polydimethylsiloxane.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060115
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Change with temperature of the ESR spectra of peroxy radicals trapped in irradiated polytetrafluoroethylenePaper presented at the 18th Chemical Society Meeting, Kyoto, Japan, April 5, 1965. (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 265-279 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The ESR spectra of peroxy radicals in irradiated powders and oriented samples of polytetrafluoroethylene (PTEE) have been measured with a K-band spectrometer, and the principal values and directions of the g tensor were determined both at room temperature and at 77°K. In contrast to the spectra of the usual peroxy radicals, those trapped in γ-irradiated PTFE exhibited an ESR spectrum apparently having a larger principal value for g⊥ than for g∥ when measured at room temperature, although the normal principal values were observed at 77°K. As for the directions of the principal axes, g∥ was directed along the chain axis at room temperature and was perpendicular to the chain axis at 77°K. From the temperature change of the g tensor and the line shapes in the oriented samples, it is shown that the observed temperature change of the spectra is due to rapid rotation at room temperature around the chain axis rather than around the C—O bond axis. Assuming this, the apparent principal values of the g tensor at room temperature were calculated from the g tensor obtained at 77°K. for the rigid state, and the results are in good agreement with observations at room temperature. A structure for the peroxy radicals is also proposed. In addition, the spectral line shape function for the uniaxially oriented samples has been derived.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060117
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Anomalous plugging of sintered glass filters by high molecular weight polymers (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 294-299 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060120
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...