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  • 1980-1984
  • 1965-1969  (2,206)
  • 1910-1914
  • 1905-1909
  • 1968  (2,206)
  • General Chemistry  (1,229)
  • Physics  (496)
  • Life and Medical Sciences  (379)
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  • 1980-1984
  • 1965-1969  (2,206)
  • 1910-1914
  • 1905-1909
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  • 1
    Electronic Resource
    Electronic Resource
    Aktiver Transport als Komponente der enteralen Phenolrotresorption (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 259 (1968), S. 260-265 
    Details
    ISSN: 1432-1912
    Keywords: Intestine ; Rat ; Phenol red ; Absorption ; Active transport ; Darm ; Ratte ; Phenolrot ; Resorption ; Aktiver Transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Phenolrot wird aus dem Jejunum der Ratte im wesentlichen passiv durch Diffusion resorbiert. Ein kleiner Anteil der resorbierten Menge folgt jedoch Charakteristica eines aktiven Prozesses. Die Resorption dieses Anteils wird durch p-Aminohippursäure (PAH) unterdrückt. In vitro baut Darmgewebe einen Teil von verabreichtem Phenolrot um, so daß es sich dem photometrischen Nachweis entzieht. Diese Reaktion wird durch PAH nicht beeinflußt. Aus dem Verhalten von PAH wird geschlossen, daß es sich bei der aktiven Elimination von Phenolrot aus dem Darm in vivo nicht um Stoffwechsel, sondern um aktiven Transport handelt, der Ähnlichkeit mit den Säuretransportmechanismen in anderen Organen zeigt. Die Phenolrotresorption ist unabhängig von der Art der Kationen in der zur Resorption angebotenen Phenolrotlösung, soweit es sich um Na-, K- oder Na-K-Ionengemische handelt. Auch wenn in der zur Resorption verabreichten Lösung alle Na- und K-Ionen durch Li-Ionen ersetzt werden, bleibt die Phenolrotresorption ohne signifikante Änderung.
    Notes: Summary Phenol red is absorbed from the jejunum of the rat mainly by diffusion. A small proportion of the amount administered, however, disappears from the gut in a way that suggests an active process. The disappearance of this part is inhibited by p-aminohippurate (PAH). In vitro, phenol red is partly metabolized by jejunal tissue. PAH has no effect on this metabolism. From the interaction of PAH it is concluded that the active elimination of phenol red from the jejunum in vivo is due to absorption by active transport and not to metabolism. This process is similar to the active transport of organic acids known in other organs in that it is inhibited by PAH. Absorption of phenol red is not influenced by the kind of cations present in the solution, as far as sodium, potassium or mixtures of both ions are concerned. Substitution of lithium for sodium and potassium does not result in significant changes in the absorption of phenol red.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00536771
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of selective hippocampal lesions in the rat on acquisition, performance, and extinction of bar pressing on a fixed ratio schedule (1968)
    Springer
    Experimental brain research 5 (1968), S. 259-266 
    Details
    ISSN: 1432-1106
    Keywords: Hippocampal Lesions ; Rat ; Fixed Ratio ; Acquisition ; Extinction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats with bilateral anterior and posterior hippocampal lesions (APH), anterior hippocampal lesions (AH), and controls were trained on CRF for water, and then switched to FR-20. Both hippocampal groups adapted more readily than controls to the FR-20 schedule and maintained significantly higher rates for 45 days. There were no significant differences on FR-20 between the lesion groups. Following FR-20, the rates of all groups were equalized by training on FR-30. During subsequent extinction, the APH group made significantly more responses than both the AH and control groups, while AH and control groups were indistinguishable. The acquisition results were interpreted as indicating increased emotional reactivity to delay of anticipated reward in both hippocampally lesioned groups. The extinction results suggested that APH, but not AH, lesions also result in increased perseveration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235901
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  • 3
    Electronic Resource
    Electronic Resource
    Correlation between noradrenaline content of the brain and the number of granular vesicles in rat hypothalamus during nialamid administration (1968)
    Springer
    Experimental brain research 5 (1968), S. 79-86 
    Details
    ISSN: 1432-1106
    Keywords: Synapse ; Granular vesicles ; Noradrenaline ; Nialamid ; Ventromedial hypothalamic nucleus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of ventromedial hypothalamic nucleus was studied in the rat with the electron microscope under circumstances of elevated brain monoamine level following treatment with a monoamine oxidase inhibitor Nialamid. The number of granular vesicles (size in diameter 450–1100 Å) in synaptic terminals increased after Nialamid treatment significantly, while their size did not change; the number of agranular vesicles remained unchanged. The time courses of the increase of granular vesicles and elevation of brain noradrenaline content were approximately parallel. It is inferred that the granular vesicles of size 450 to 1100 Å may possibly be the storage sites of noradrenaline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238698
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  • 4
    Electronic Resource
    Electronic Resource
    Zur hormonellen Beeinflussung des Hexobarbitalschlafes der Ratte (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 259 (1968), S. 413-418 
    Details
    ISSN: 1432-1912
    Keywords: Cyproterone Acetate ; Hexobarbital Narcosis ; Rat ; Testosterone ; Enzyme Induction ; Cyproteronacetat ; Hexobarbitalnarkose ; Ratte ; Testosteron ; Fermentinduktion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An geschlechtsreifen Ratten wurde der Einfluß des Antiandrogens Cyproteronacetat auf die Hexobarbitalnarkose bei Ratten in Abhängigkeit vom Hormonstatus geprüft. Cyproteronacetat entfaltet in diesem Versuchsmodell nicht seine sonst bekannte spezifische Hemmwirkung gegenüber endogenem und injiziertem Testosteron. Die Vorbehandlung mit Cyproteronacetat führt zu einer Steigerung der mikrosomalen Fermentaktivität in der Leber und damit wahrscheinlich zu einem schnelleren Abbau von Hexobarbital. Die Folge ist eine erhebliche Narkosedauerverkürzung durch diese Verbindung.
    Notes: Summary The influence of the antiandrogen Cyproterone acetate on Hexobarbital narcosis in relation to the hormonal state was investigated in adult rats. In this test model Cyproterone acetate failed to exert its wellknown specific inhibitory action on endogeneous and injected testosterone. Pretreatment with Cyproterone acetate led to enhanced microsomal enzyme activity in the liver and thus probably to a more rapid metabolism of Hexobarbital. The result of this is a significant shortening of the duration of narcosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00538555
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  • 5
    Electronic Resource
    Electronic Resource
    Effects of methylphenidate, pentobarbital, and reserpine on behavior controlled by a schedule of interresponse time reinforcement (1968)
    Springer
    Psychopharmacology 13 (1968), S. 49-64 
    Details
    ISSN: 1432-2072
    Keywords: Operant Behavior ; Methylphenidate ; Pentobarbital ; Reserpine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three rats, deprived of water, were given separate injections of methylphenidate and pentobarbital after each had received extensive training on a DRL schedule of reinforcement, modified by the inclusion of a limited-hold. Methylphenidate (2.5, 5.0, and 10.0 mg/kg) increased response rates at each of these dosages; pentobarbital increased response rates at dosages of 2.5 mg/kg and 5 mg/kg but had little effect on overall response rate at 10 mg/kg though, at this dose, performance was characterized by periods of rapid responding alternating with periods of inactivity. The rate-increasing effects of the two drugs were found to be qualitatively different. Several mixtures of the two drugs induced rate increases greater than those found when each drug was given separately. However, pentobarbital (10 mg/kg) reduced the rate-increasing effects of methylphenidate obtained when the latter was given alone at a dosage of 10 mg/kg. Chronic pretreatment with reserpine (0.3 mg/kg for 12 days), given to two animals, progressively reduced rate of responding. Methylphenidate antagonized the effects of reserpine as an increasing function of dosage but the resulting pattern of behavior more closely resembled the effects of methylphenidate given alone than performance recorded in the absence of any drug treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00401618
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  • 6
    Electronic Resource
    Electronic Resource
    Die Abhängigkeit der Oberflächenkräfte isolierter Rattenlungen von Atmung, Temperatur und Stoffwechsel (1968)
    Springer
    Pflügers Archiv 304 (1968), S. 315-321 
    Details
    ISSN: 1432-2013
    Keywords: Lung ; Alveolar Surface Tension ; Aerobic Metabolism ; Breathing Mechanics ; Rat ; Lunge ; Alveoläre Oberflächenspannung ; Oxydativer Stoffwechsel ; Atemmechanik ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Beatmet man isolierte Rattenlungen mit Drucken von 0–25 cm H2O (Überbeatmung), so zeigen sich im statischen Druck-Volumen-Diagramm Veränderungen, die auf eine Zunahme der Oberflächenspannung in den Lungenalveolen hinweisen. Läßt man die Lungen im Anschluß an die Beatmung 30 min im geblähten Zustand, so wiest das Verhalten despV-Diagramms auf ein Wiederabsinken der alveolären Oberflächenspannung hin, wenn die Versuche bei 37°C vorgenommen wurden, während eine derartige Änderung bei 20–24°C nur angedeutet nachzuweisen ist. 2. Wird der oxydative stoffwechsel durch Beatmung der Lunge mit N2 oder Vergiftung mit KCN ausgeschaltet, so zeigen sich prinzipiell sowohl während der Beatmung als auch in der Restitutionsphase die gleichen Verhältnisse, nur daß unter anoxischen Bedingungen die alveoläre Oberflächenspannung während der Beatmung noch etwas stärker ansteigt. Danach spielt der oxydative Stoffwechsel für die beobachteten Erscheinungen eine untergeordnete Rolle. 3. Wahrscheinlich wird durch die Überbeatmung der Oberflächenfilm in den Lungenalveolen mechanisch geschädigt, wobei ein Teil des oberflächenaktiven Materials inaktiviert wird. Eine Restitution könnte durch Wiederspreitung des inaktivierten Materials oder durch Übertreten von LAS aus den Alveolarzellen an die Alveolaroberfläche erfolgen.
    Notes: Summary The effect of ventilation on the lung alveolar lining layer has been demonstrated by analysis of pressure-volume diagrams. Ventilation of isolated rat lungs at intrapulmonary pressures of 0–25 cm H2O caused an increase of surface forces in the lungs. After ventilation was stopped the lungs were kept inflated at intrapulmonary pressures of 25 cm H2O up to 60 min. Subsequent analysis of the pressure-volume diagrams indicated a decrease of surface forces at 37°C while at 20–24°C only little recovery occurred. The influence of ventilation with N2 or poisoning with KCN on aerobic cell metabolism was investigated. The increase of surface forces was only slightly more pronounced by anoxia during lung-ventilation than in the above experiments. Aerobic cell metabolism, therefore, did not play an important role in our experiments. It is very likely that the decrease of surface activity following ventilation was caused by mechanical changes of the alveolar lining layer. We believe that, to some extent, the lung alveolar surfactant was inactivated. Recovery can be explained by new spreading of inactivated materials or by passage of lung alveolar surfactant from the alveolar cells to the alveolar surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00587707
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  • 7
    Electronic Resource
    Electronic Resource
    Zur Resorption freier und konjugierter Gallensäuren im Dünndarm der Ratte in vitro und in vivo (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 261 (1968), S. 314-328 
    Details
    ISSN: 1432-1912
    Keywords: Rat ; Gut ; Absorption ; Free Bile Acids ; Conjugated Bile Acids ; Ratte ; Darm ; Resorption ; freie Gallensäure ; konjugierte Gallensäuren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Zur Klärung der Frage, ob für die Anreicherung freier Gallensäuren in Coecum und Colon eine unterschiedliche Resorption freier und konjugierter Gallensäuren im Dünndarm mitverantwortlich ist, wurden in vitro an nicht durchbluteten, isoliert durchströmten Dünndarmsegmenten der Ratte ihr Durchtritt und ihre Bindung untersucht. Die Ergebnisse wurden mit denjenigen verglichen, die in vivo an durchbluteten, abgebundenen Ileumschlingen bei Ratten in situ gewonnen wurden. Folgende Gallensäuren standen zur Verfügung: Cholsäure, deren Taurin- und Glycin-Konjugat; Desoxycholsäure sowie deren Taurin- und Glycin-Konjugat. 2. Die in vitro-Versuche ergaben, daß konjugierte Gallensäuren, gemessen an der Konzentration im Resorbat, in größerem Umfange als freie durch die Mucosa treten. Je polarer die Gallensäure, desto größer die Durchtrittsrate. Beim Durchtritt werden weder freie Gallensäuren mit Taurin bzw. Glycin konjugiert, noch werden Gallensäure-Konjugate in nennenswertem Umfange hydrolytisch gespalten. Der durch die Darmwand gebundene Anteil freier Gallensäuren ist größer als der konjugierter. 3. In vivo erfolgt die Resorption aus Ileumschlingen so schnell, daß innerhalb von 15 min von allen Gallensäuren gleichviel resorbiert wird. Das Ausmaß der Bindung der Gallensäuren in der Darmwand ist unterschiedlich. Von Desoxycholsäure wird auch in vivo doppelt soviel gebunden wie von Glykocholsäure. 4. Das Ergebnis der Versuche besagt, daß in vivo eine geringere Resorption für die Anreicherung freier Gallensäuren im Dickdarm keine Rolle spielt. Die Unterschiede im Durchtritt freier und konjugierter Gallensäuren in vitro sind methodisch bedingt.
    Notes: Summary 1. In order to elucidate the question whether the coecal and colonic accumulation of free bile acids is caused by different absorption of free and conjugated bile acids in the small intestine, their penetration and their binding were studied in vitro in isolated rat gut segments. The results were compared with those in vivo obtained with tied loops in situ. The following bile acids were available: cholanic acid, its taurine and glycine conjugates; deoxycholic acid and both its conjugates. 2. The experiments in vitro showed that relative to the concentration in the absorbed fluid, the penetration rate of conjugated bile acids is higher than that of free bile acids. The more polar a bile acid is the greater is the penetration rate. During penetration neither free bile acids are conjugated with taurine or glycine nor conjugated bile acids are hydrolysed. 3. In vivo absorption in ileal loops is so rapid that within 15 min the absorption rate is nearly the same for all bile acids. The amounts of bile acids bound by the tissue vary. In vivo, as in vitro, twice as much deoxycholic acid is bound as glycocholic acid. 4. The results show that in vivo a lesser absorption is of no significance for the accumulation of free bile acids in the colon. The difference in the absorption of free and conjugated bile acids in vitro is caused by the method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00537176
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  • 8
    Electronic Resource
    Electronic Resource
    Der Einfluß von Liganden auf die Retention von Eisen nach oraler Verabfolgung an normale und anämische Ratten (1968)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 261 (1968), S. 225-238 
    Details
    ISSN: 1432-1912
    Keywords: Iron Deficiency ; Iron Absorption ; Iron Complexes ; Rat ; Eisenmangel ; Eisen-Resorption ; Eisenkomplexe ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Die Retention von freiem und komplexgebundenem 59Fe-Eisen wurde 6 Tage nach Verabreichung mit der Schlundsonde bei normalen und anämischen Ratten in einer Ganztiermeßanlage bestimmt. 2. Anämische Ratten nahmen fünfmal mehr Eisen auf als normale Tiere, wenn ionisiertes Eisen angeboten wurde. Alle geprüften Komplexbildner vermindern die gesteigerte Eisen-Retention anämischer Ratten. Bezogen auf die Werte der anämischen Gruppe (=100%) wurde die Retention durch EDTA um 87%, durch Citronensäure um 40%, durch Ascorbinsäure um 32% und durch Nicotinhydroxamsäure um 31% herabgesetzt. 3. In Gegenwart von Komplexbildnern ist die Eisen-Retention anämischer Tiere bei Citronensäure 8,7, von EDTA 6,3, von Nicotinhydroxamsäure 3,7 und von Ascorbinsäure 2,7 mal höher als bei normalen.
    Notes: Summary 1. In normal and anemic rats, the retention of free and complex-bound 59Fe-iron was measured with a whole body counter 6 days after its oral administration. 2. If the iron is administered in the ionic form to iron-deficient rats they show a retention of iron 5 times greater than that of normal animals. The increased iron retention of anemic rats is diminished by all complexing agents tested. EDTA reduced it by 87%, citric acid by 40%, ascorbic acid by 32% and nicotine hydroxamic acid by 31%. 3. When the iron is combined with citric acid its retention by iron-deficient rats was 8.7 times increased in comparison to normal rats, with EDTA 6.3 times, with nicotine hydroxamic acid 3.7 and with ascorbic acid 2.7 times.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00536987
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  • 9
    Electronic Resource
    Electronic Resource
    Methoden der Nierenpunktion bei der Ratte (1968)
    Springer
    Clinical and experimental medicine 145 (1968), S. 260-265 
    Details
    ISSN: 1591-9528
    Keywords: Renal puncture ; Renal needle biopsy ; Rat ; Nierenpunktion ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 90 Ratten wurden insgesamt 266 Nierenpunktionen durchgeführt. Selbst Serienbiopsien (bis zu acht Eingriffen pro Tier bzw. bis fünf Punktionen pro Niere) mit Intervallen von wenigen Tagen wurden gut vertragen. Drei Methoden wurden versucht: percutane Blindbiopsie, Punktion unter Sicht von dorsal (extraperitoneal) bzw. von ventral (transperitoneal). Bei Berücksichtigung der wichtigsten Momente (Ergiebigkeit des Punktates, Schwierigkeit des Eingriffes — auch bei nachfolgenden Punktionen —, lokale Folgen an der Niere und Umgebung) hat sich dastransperitoneale Vorgehen als dieMethode der Wahl erwiesen und ausgezeichnete Ergebnisse geliefert. Die Nierenpunktion der Ratte kann besonders zum Studium des Verlaufes experimenteller Nierenkrankheiten mit morphologischen Methoden empfohlen werden.
    Notes: Summary In 90 rats 266 renal puncture biopsies were performed. Even serial biopsies (up to eight per animal or up to five punctures per kidney, respectively) were tolerated very well. Three methods were attempted: Percutaneous blind biopsy, puncture under direct vision by a dorsal (extraperitoneal) approach and by a ventral (transperitoneal) one. Considering the most important factors (e.g. amount of the puncture sample, difficulty of the procedure even in subsequent punctures, local damage to the kidney) the transperitoneal approach has proved to be the method of choice and excellent results were obtained. Renal puncture of rats are especially suitable for studying diseases of the kidney by morphological methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02044616
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  • 10
    Electronic Resource
    Electronic Resource
    Normale Verteilung51Cr-markierter Lymphocyten in der Ratte und ihre Änderung nach Antilymphocytenserum (1968)
    Springer
    Clinical and experimental medicine 146 (1968), S. 275-283 
    Details
    ISSN: 1591-9528
    Keywords: Anti-lymphocyte serum ; 51Cr-labelled lymphocytes ; Rat ; Antilymphocytenserum ; 51Cr-markierte Lymphocyten ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. 48 Ratten wurden in Äthernarkose 107 51Cr-markierte Lymphocyten suspendiert in Hankscher Lösung und Heparin in die V. femoralis injiziert. Ein Teil der Tiere bekam gleichzeitig Antilymphocytenserum. Dabei wurde festgestellt, daß der normale Abbau51Cr-markierter Lymphocyten in einer bestimmten zeitlichen Reihenfolge in Lunge, Leber, Milz und peripheren Lymphknoten vonstatten geht und51Cr durch die Niere ausgeschieden wird. Ein Wiederansteigen der Radioaktivität in den erwähnten Organen nach 18–22 Tagen wird mit einem Reutilisationseffekt erklärt. 2. Durch Kaninchen-Anti-Ratten-Lymphocytenserum (ALS) wird diese Verteilung beschleunigt und verändert. In der Lunge findet man eine sehr starke, in der Milz dagegen fast gar keine Anhäufung51Cr-markierter Lymphocyten, was auf eine Schädigung dieses Organs durch ALS hinweisen könnte.
    Notes: Summary 1. 107 51Chromium-labelled lymphocytes have been injected into the femoral vein of 48 rats in aetheranaesthesia. The lymphocytes were suspended in heparinized Hank's solution. 20 animals were treated with antilymphocyte serum at the same time. The normal distribution of51Cr-labelled lymphocytes was found to take place in lung, liver, spleen and peripheral lymphnode in a certain chronological order.51Chromium is eliminated by the kidney. After a period of 18–22 days an increase of radioactivity is found in organs mentioned above which is to be explained by reutilisation of radioactivity. 2. This normal distribution is changed by rabbit-anti-rat-lymphocyte serum. In the lung it is found more of51Cr-labelled lymphocytes in the spleen less than in control animals. These findings suggest a damaging effect induced by antilymphocyte serum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02043637
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  • 11
    Electronic Resource
    Electronic Resource
    The fine structure of wound repair in an insect (Rhodnius prolixus) (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 37-77 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cells surrounding a wound in the integument of Rhodnius adults show an increase in RNA content, cytochrome oxidase and esterase activity. An excision in the integument is filled by blood which coagulates and is tanned into an insoluble membrane. The basement membrane of the adjoining epidermis acts as a self-sealing membrane and contracts to cover the excision. The epidermis is attached to the cuticle by the subcuticular layer which it resorbs and by pore canal filaments which are left behind as it migrates. The epidermis migrates as a sheet in contact with the cuticle then with the coagulated blood and basement membrane which cover the excision. Blood cells migrate individually into an excision and do not adhere to a surface in the process. Microtubules cannot be identified with movement. Both epidermal and blood cells remove the cells killed by wounding as evidenced by the appearance of coated vesicles and phagocytic bodies in both cell types. The reconstituted integument consists of a surface membrane in which the layers of the epicuticle are not distinguishable, a nonlamellate cuticle secreted by an epidermis which also appears to secrete the new basement membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051240104
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  • 12
    Electronic Resource
    Electronic Resource
    Intraneural vascular response to defective development of the chick mesencephalonSupported by grant 5 RO1-HD-01679-02 from the USPHS National Institutes of Health. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 295-311 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The development of intraneural vessels was studied in response to an induced hypermorphosis of neural tissue inthe midbrains of 38 chick embryos ranging in age from three days through 14 days of incubation. The pattern of vascularization was compared with that of normal chick embryos at comparable stages of development. In the experimental embryos, the increase in mitotic figures along the ventricular borders of the mesencephalon is accompanied by the establishment of an endoneural plexus approximately one day earlier than is the case during normal vascularization of the midbrain. This plexus also penetrates more deeply and extensively into the ependymal layer. Surface vessels and intraneural vascular elements are dilated, and the cerebrospinal fluid contains varying amounts of blood released from large intraneural vessels which protrude into the ventricle. The most prominent cerebrovascular effects seem to occur between the fourth and eighth days of incubation. Thereafter, the cerebrovascular pattern becomes more normal except for relatively few isolated hemorrhagic areas.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051240304
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  • 13
    Electronic Resource
    Electronic Resource
    Structure of the eye of Haideotriton wallacei, a North American troglobitic salamander (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 345-351 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The eye of Haideotriton wallacei is more reduced histologically than those of othe troglobitic salamanders. The tiny eye is imbedded in a mass of adipose tissue. No extrinsic eye muscles are present. A rudimentary lens is present in about half of the eyes examined. In two instances the lens is surrounded by a small chamber; most eyes lack a chamber. The retina and iris are relatively undifferentiated. The relatively massive retina lacks rods and cones, an outer plexiform layer and subdivided nuclear layers. A tiny optic nerve runs to the brain.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051240307
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  • 14
    Electronic Resource
    Electronic Resource
    Fine structure of the aesthetasc hairs of Coenobita compressus edwardsThis work was supported by University of California Faculty grant 308 and U.S. Public Health Service grant NB04372. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 361-385 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The aesthetascs, short thin-walled pegs on the antennule flagella of Coenobita clypeatus, a terrestrial hermit crab, are similar to those of other decapod crustacea in containing the dendrites of many bipolar neurons whose cell bodies are grouped in spindle-shaped masses beneath the bases of each hair. The dendrites contain rootlets, basal bodies, and cilia, which divide dichotomously before entering the aesthetasc, so that within the hair, each cilium becomes represented by a group of slender branches.The aesthetascs themselves are short, blunt, and partially recumbent so that each has an exposed and an unexposed side. The cuticle on the exposed side is thinner and more tenuous than that on the protected side, and the dendrite branches are concentrated just underneath. The protected side, on the other hand, is lined with nondendritic supporting cells, and the cuticle is thicker, more lamellar, and probably less permeable.All dendritic elements proximal to the dendrite branches are enclosed within the main body of the antennular flagellum, and the initial segments of the cilia lie within a vacuole. In these respects, the aesthetascs of Coenobita resemble the thin-walled pegs on insect antennae more than they do those of the marine decapods thus far examined. This convergence in the terrestrial forms may be in response to the need to conserve water.
    Additional Material: 2 Ill.
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    A light and electron microscopic investigation of the digestive system of the Ophiuroid ophiuroiderma panamensis (Brittle Star)This work was supported in part by U.S.P.H.S. grant NB 03604. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 451-481 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Brittle Star digestive system is composed of buccal, pharyngeal, esophageal and stomach cavities. The buccal and pharyngeal cavities are lined by columnar cells covered by a cuticle, and are apparently concerned with mucous production. Coelomocytes and tall columnar cells are described in the esophagus and stomach epithelia. The columnar cells are adapted for nutrient absorption, enzyme synthesis, and lipid storage. Nerves are found beneath the epithelia within a connective tissue layer. Smooth muscle and coelomic layers lie external to the connective tissue layer. The coelomic layer lines a perivisceral space and has diverse modifications of its perivisceral surface; a pedicle-cuticle modification perhaps having general significance in echinoderms.
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    URL: http://dx.doi.org/10.1002/jmor.1051240405
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  • 16
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    The fine structure of the Limulus optic nerve (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 61-70 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two complete composite photographs of the optic nerve of Limulus, made by electron microscopy, reveal the presence of neurosecretory granules in the large axons of the rudimentary eye neurons. The number of intermediate sized, (3-7 μ), of eccentric cells corresponds with the number of ommatidia as expected, but only their sheath of Schwann cells show an intimate interfolding. Based on the number of fine axons within the nerve each ommatidium has an average of 12-13 retinular cells. The diameter of their fibers is between 0.2 and 3 μ although the majority are between 1 and 1.5 μ. They are aggregated into bundles of six to seven fibers by the sheath cells although some bundles contain only two, others as many as 181 fibers. There is no indication in these studies that retinular cell axons within a bundle are associated with the same, adjacent, or other pattern of ommatidia. The photographs suggest that physiological activity in retinular cell axons might be detected most easily in the smallest bundles because they contain the fewest, but the larger retinular cell axons.
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  • 17
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    Anatomical changes in the neuromuscular complex of the proleg of Galleria mellonella (L.) (Lepidoptera: Pyralidiadae) during metamorphosisBased on part of a thesis submitted in partial fulfillment of the requirements for the Doctor of Philosophy degree in the Department of Entomology and Parasitology, University of California, Berkeley. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 105-127 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The lateral and ventral external surfaces of the third and fourth abdominal segments were described and muscle attachments were correlated with surface indentations of the larva. The proleg of this species has a symmetrical planta with a complete circle of crochets. Furthermore, it differs externally from the grasping type of proleg in having a largely membranous coxal region confluent with the body wall, and a relatively large subcoxal lobe.The body wall musculature and innervation of the third and fourth abdominal segments are similar in many respects to those described for other lepidopteran larvae to which they are here compared, but differ from most because of the simpler structure of the prolegs which lack highly developed adductor muscles. Like most muscles innervated by the ventral nerve, the principal plantar retractors of these two segments cease to function in the first day of the pupal stage and have completely degenerated by the forty-fifth hour of pupal life. The ventral nerve retains its four primary branches in the adult, in which many smaller rami can be traced to the cuticle and to the neoblastic body wall muscles.
    Additional Material: 1 Tab.
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  • 18
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    Musculature, nervous system and glands of pregenital abdominal segments of the female of Nomia melanderi Ckll. (Hymenoptera, Apoidea)Supported by grant 12-14-100-8072(33) from Agriculture Research Service, USDA. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 205-217 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The gross anatomy of muscles, the topography of nerve tissues, and the histology of the pregenital abdominal glands of Nomia melanderi Ckll. are reported in detail. The movable and fixed points of muscle attachment were utilized in establishing a system of nomenclature for a typical abdominal segment. Names of nervules correspond to those of the tissues they innervate. The points of attachment of muscles of the fifth abdominal segment are essentially the same in both Nomia and Apis, except for the second tergo-sternal muscle which, in Nomia, has shifted its point of movable attachment to the membranous integument in front of the intersegmental membrane gland where it helps in relasing glandular secretion. The general plan of the nerves in the fifth abdominal segment in Nomia is more diffuse than in Apis, but there is no difficulty in establishing homology between the nervules of the two species. A pair of intersegmental stretch organs was found in abdominal segments 3-6. Glands of the sixth intersegmental membrane possess a reservoir with peripheral pouches both of which are absent in those of the fifth. Both types of glands have neither closing nor opening mechanisms, and neither is innervated. Release of glandular secretion is accomplished by the action of the tergo-sternal muscles.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051250206
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  • 19
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    Pineal regeneration in the frog, Rana pipiens, following embryonic extirpationThis investigation was supported by N.I.H. Predoctoral Fellowship GM-32771-01. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 253-257 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This report describes the capacity of larvae of the Leopard frog, Rana pipiens, to regenerate pineal tissue after embryonic pinealectomy, and presents experimental evidence for frontal organ dependence on the epiphysis. In addition, it was found that the “brow spot,” a pigment-free region located in the epidermis betweeen the eyes, is dependent on the frontal organ for its formation. This report also substantiates that the absence of the pineal organ in larval animals does not affect growth or development through metamorphosis.
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    URL: http://dx.doi.org/10.1002/jmor.1051250208
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  • 20
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    The structure of the antennae of the Florida Queen butterfly, Danaus gilippus berenice (Cramer) (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 315-328 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Interest in the structure of the antennae of the Florida Queen butterfly arises from the finding that a pheromone is active in their courtship. Light and electron microscopic techniques were used to study the sensilla on the antennae and three types of sensilla with perforated walls were identified. The most common of these are short, thin-walled pegs which are distributed over most of the antennal surface. Long, curved, thin-walled pegs occur in patches on the inner medial antennal surface. Multiple coeloconic sensilla are present having up to 50 pegs in one sensillum. On the outer 28 flagellar subsegments there are two such sensilla per subsegment. In addition there are on the antennae long, thick-walled hairs which are mechanoreceptors and probably also contact chemoreceptors. Sunken pegs, the function of which is not known, occur on the antennae. Grooved sensilla were found with the electron microscope but could not be identified with the light microscope. There was no indication of sexual dimorphism in sensilla types or numbers on the antennae.
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    Oxidative enzyme histochemistry of the chick esophagus and proventriculusSupported by USPHS grant AM-05429, National Institute of Arthritis and Metabolic Diseases. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 403-417 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Succinic dehydrogenase, NAD and NADP diaphorases, choline oxidase, d-amino acid oxidase, α-glycerophosphate dehydrogenase, glutamic dehydrogenase, lactic dehydrogenase and aldolase were identified histochemically in the esophagus and proventriculus of the developing chick embryo. In general, the deep glands of the proventriculus reacted more strongly than the epithelium and mucous glands of the esophagus to the tests. The intensity of the enzymatic activity seems correlated with the number of mitochondria and metabolic activity of the cells.
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    URL: http://dx.doi.org/10.1002/jmor.1051250403
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  • 22
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260101
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    Sense organs on the antennal flagellum of a giant cockroach, Gromphadorhina portentosa, and a comparison with those of several other species (Dictyoptera, Blattaria)Supported in part by a grant from the National Science Foundation GB-7310. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 19-29 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Two kinds of tactile hairs, plain and wavy, thick-walled chemoreceptors and two types of thin-walled chemoreceptors are present on the antennal flagellum of Gromphadorhina portentosa males. These are described and their location on the antenna noted. Females of this species have plain tactile hairs and the same types of chemoreceptors as do the males but wavy tactile hairs are absent. The antennal sense organs of a few specimens of five other species of cockroaches  -  Periplaneta americana, Blatta orientalis, Supella longipalpa, Pycnoscelus surinamensis and Diploptera punctata  -  were also examined. All lacked tactile hairs but were provided with thick-walled chemoreceptors and with two types of thin-walled chemoreceptors similar to those described for Gromphadorhina portentosa.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051260103
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    Studies on hydroid differentiation. III. The replacement of hypostomal gland cells of Podocoryne carneaSupported by grants from the U. S. Public Health Service (GM 13708) and from the National Science Foundation (GB 5021). (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 95-106 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Pulse labeling with tritiated thymidine has permitted the identification of a progenitor cell compartment at the base of the hypostomal glandular ridges of the marine hydroid Podocoryne carnea. This progenitor compartment produces cells which move out on the ridges differentiate as digestive gland cells, and are ejected into the gastro-vascular cavity. Spherous gland cells of the body appear not to be part of this circumscribed replacement system. There appears to be no proximal movement of gastrodermal cells in the body of this marine hydroid.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051260106
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  • 25
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    A Comparative anatomical study of the mammalian uterotubal junctionScientific paper 3052; Project 1956 College of Agriculture Research Center. This investigation was supported in part by research grants HD-00585-03, HD-00745, and symposium contract PH-43-67-672 from the National Institute of Child Health and Human Development U.S.P.H.S., and Lillian Banta Research Fund. Thanks are due to the University of Washington Primate Information Center for providing a list of references and to Drs. R. M. Brenner, O. Smith, and F. Young for providing specimens of monkeys. Several helpful suggestions and criticisms have been made by Drs. R. J. Blandau and R. J. Blandau and R. E. Click. Thanks are also due to Mr. Steve Allured for preparing some of the drawings and to Mr. J. A. Lineweaver for the microphotography. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 159-184 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Among eight species of mammals in this study (cattle, sheep, pig-tail and rhesus monkeys, rabbit, pig, rat, and dog) four basic patterns of anatomical structure at the uterotubal junction are described. The classification of types is based upon the presence or absence of an intramural portion of the oviduct and of isthmal folds or plicae projecting into the lumen of the uterine cornu.Histological variations are reported for three tissues: epithelial and connective of the mucosa and smooth muscle of the tunica muscularis. In the epithelium during the estrous cycle the differences recorded include: (a) absence of ciliated cells in the distal end of the oviduct in rat and dog; (b) variations in ciliated and nonciliated cells in (1) cell height, (2) location, shape and stainability of the nucleus, and (3) in amount and stainability of apical cytoplasm; (c) presence of lymphoblast-like cells which appear to migrate through the epithelium from the lamina propria. The connective tissue of the mucosa, as a circular layer and as cores for the mucosal folds, shows variations in thickness and in relative density of cells and fibers of the matrix. Emphasis is given to the presence of an inner longitudinal layer of smooth muscle in the tunica muscularis of the distal oviduct in six of the eight species.
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    The fine structure of the colleterial glands of Hyalophora cecropia (Lepidoptera) (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 259-279 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure of cells in the colleterial glands of the Cecropia silkmoth was examined. Morphologically and functionally the gland is divided into two regions, a tubular one in which columnar protein-synthesizing cells are located, and an expanded region in which flattened cells with very different structure are most prominent. The fine structure of the latter cells which are presumed to secrete a phenolic glucoside, closely resembles that of cells described in the colleterial glands of orthopterans. The protein-secreting cells have many features normally associated with pancreatic acinar, and other cells of similar function. Among these are extensive rough endoplasmic reticulum, an elaborate Golgi complex, and a modest number of mitochondria. Other features which are less usual in cells of this type are an elaborate secretory apparatus consisting of a cuticular tubule inserted into a microvilli-lined cavity at the apical end of the cell, and large numbers of cytolysomes, myelin figures, and lipid droplets. A chitogenous cell with a very distinct and specific type of ultrastructure is found associated with the secretory cell. This cell type is attached to the cuticular elements of the gland, and the main features of its cytoplasm are extensive bundles of microtubules which presumably serve as supportive elements for the secretory cells.
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    Embryonic development of the heart. I. A light and electron microscopic study of myocardial development in the early chick embryo (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 329-365 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Embryonic chick myocardium (stages 8+ to 12-) was studied by light and electron microscopy. The myocardium, which is initially comprised of radially oriented cells with large intercellular spaces gradually becomes more tightly packed. Intercellular spaces decrease and the cells assume a circumferential orientation. Myocardial cells remain epithelial throughout formation of the functional tubular heart and specialized epithelial junctions (apical junctional complex or terminal bars) undergo modification to form intercalated discs. Embryonic myocardial cells contain large amounts of free ribosomes and particulate glycogen, the latter often associated with portions of granular reticulum. Unlike developing skeletal muscle. The amount of granular reticulum contained in the myocardial cell cytoplasm is large and, along with a hypertrophied Golgi apparatus, suggests that these cells may have a secretory function. These organelles persist during the initial period of fibril formation. Myofibrils apparently form from non filamentous precursor material and not by alignment of sequentially synthesized components.
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    Histological changes in the epidermis of the subdigital lamellae of Anolis carolinensis during the shedding cycle (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 379-401 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The characteristic anoline climbing organ consists of a number of lamellar scales, on whose outer scale surface are numerous keratinized setae which contact the substrate. These setae are derived from the Oberhautchen of the epidermal generation, and as such are renewed and shed periodically along with the rest of the epidermal material. The histological development of the setae is described, and modifications of the surrounding elements are noted. The relative lengths of the setae and their congregation to form a pad unit poses certain mechanical problems during morphogenesis, simply in terms of accommodation between the functional outer epidermal generation and dermal core of each lamella. Regression of the dermal core and a distal migration of some cells permits accommodation within the lamella for the distal aspect of the Oberhautchen layer, or free margin. Additionally, changes in the gross shape of the lamella occur throughout the sloughing cycle, and a swelling of the cells of the lacunar tissue results in a gap between the stratum corneum of inner and outer epidermal generations. There is a considerable amount of variation in mitotic activity between the germinal layers of opposite sides of the lamella.
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    URL: http://dx.doi.org/10.1002/jmor.1051250402
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    Excretion and ultrastructure of the antennal gland of the fiddler crab Uca mordaxThis work was supported by grant AMO 9975-01 of the National Institutes of Health, Bethesda, Maryland. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 473-495 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Function and ultrastructure of the excretory organs (antennal glands) of the shore crab Uca mordax were investigated. The crabs were maintained at three different salinities: 50%, 100% and 200% seawater. In spite of previous reports to the contrary, the investigation showed that the powerful osmoregulatory ability found in Uca mordax is not due to participation of the antennal glands. Freezing point depression of urine under all conditions was found to be slightly less than that of the hemolymph, indicating a slightly hypoosmotic urine. It was further found that the antennal gland is extremely effective in resorbing sodium from the filtrate. The higher the salinity to which the crabs were acclimated the lower the sodium concentration in the urine. No water was resorbed from the filtrate as shown by the fact that the inulin U/P ratio remained unity regardless of the salinity to which the crabs were adapted. Electronmicroscopy of the antennal glands revealed that the coelomosac cells are similar to the podocytes described in the crayfish by Kümmel ('64), and the coelomosac appears to be a typical filtration organ. The cells of the labyrinth showed brush border and very elaborate basal infoldings with numerous mitochondria. The deep cytoplasmic infoldings which represent interdigitations with neighboring cells may be correlated with the effective sodium reabsorption in the labyrinth, but apparently not with water movement.
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    URL: http://dx.doi.org/10.1002/jmor.1051250406
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    An electron microscope study of nebenkern formation and differentiation in spermatids of Murgantia histrionica (Hemiptera, Pentatomidae) (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 31-65 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mitochondria in early spermatids of many insects aggregate and form a round body, the nebenkern. The nebenkern undergoes a structural differentiation and then divides into two separate equal-sized bodies. In the present study, nebenkerns of Murgantia histrionica, a Hemipteran insect, were reconstructed using electron micrographs of serial sections to determine how the mitochondria transform into the two separate bodies.Newly formed nebenkerns are made of one piece, an anastomosis of rod-like segments. Some segments interconnect to join networks of rings. Each network interlocks with another similar network, but networks which interlock are connected with each other by other segments of the nebenkern. Later, the entire nebenkern is made of two unconnected and interlocked networks of rings. The nebenkern appears to remain bipartite during subsequent differentiation. Since the two pieces are interlocked, breaks must occur before the pieces can separate. As breaks occur, each network transforms into a set of curved sheets, producing a nebenkern made of four concentric layers. The three outer layers are each made of two curved sheets which surround a bipartite central core. The surface sheets meet at a furrow in the surface of the nebenkern; segments in each layer are roughly symmetrical with each other about the plane in which the furrow lies. Rod-like segments join alternate segments. The number of layers then decreases to three, and later, to two. These nebenkerns resemble four-layered nebenkerns, but fewer connections between alternate segments are present. The two pieces constituting the nebenkern probably separate after most of the latter connections disappear. Hypotheses to account for the observed changes in nebenkern structure are presented.
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260201
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260301
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051240101
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060104
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060106
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  • 36
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    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
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  • 37
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060112
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  • 38
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    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
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  • 39
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    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
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  • 40
    Electronic Resource
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060205
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  • 41
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    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
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  • 42
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060304
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  • 43
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    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 
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    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
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  • 44
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    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 
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    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
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  • 45
    Electronic Resource
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    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 
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    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
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  • 46
    Electronic Resource
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    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 
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    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
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  • 47
    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060610
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  • 48
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    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 
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    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
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  • 49
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060509
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  • 50
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060402
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060604
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060607
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  • 53
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060608
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  • 54
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060503
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  • 55
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060507
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  • 56
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060510
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  • 57
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060512
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060514
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060904
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060602
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160061001
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160061006
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060701
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    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 
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160060705
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    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.
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    URL: http://dx.doi.org/10.1002/pol.1968.160061206
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    Myocardial ultrastructure and electrocardiograms of the sloth (Bradypus tridactylus) under normal and experimental conditionsSupported (in part) by the U. S. Public Health Service, General Research grant 1-SO1-FR-05070-01 and by the Chicago and Illinois Heart Assocations, Grant-in-Aid N66-10. Presented in part at the American Society for Cell Biology Meeting, November 19, 1966, in Houston, Texas. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 83-103 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Adult sloths (Bradypus tridactylus) were studied by electrocardiography and by light and electron microscopy under normal conditions and under experimental conditions as provided for by injection of 2,4-dinitrophenol (DNP) and ether anesthesia. ECG's of the animals indicated heart rates of 45-71/min, which can be considered as the normal heart rate of the sloth under laboratory conditions. Under normal conditions, the contracted ventricular myocardium of the sloth exhibited (a) a wrinkled sarcolemma, (b) the usual pattern of myofibrils and of sarcoplasmic reticulum, (c) small mitochondria with spiked and branched, often anastomosed cristae, including a few small intramitochondrial dark bodies, (d) an amount of sacrcosomes smaller than the amount of myofibrils, (e) many glycogen granules, isolated, in the form of a chain, or as clusters, in subsarcolemmal, intermyofilamentous and perimitochondrial positions, (f) few multivesicular bodies and (g) large flat sections of the transverse tubular system.Injection of DNP (1 mg/kg) caused tachycardia. With ether anesthesia, the ECG showed monophasic action potential of myocardial injury and prolongation of inter or intraventricular condition. Electrically, the sloth's heart responded to hypoxia as do other mammalian hearts.The administration of DNP produced (a) derangement and reduction in number and length of the mitochondrial cristae, (b) disappearance of spikes, connections between the cristae and, consequently, the honeycombed arrangement, (c) increased matricial space in the center of mitochondria which was often filled with a grayish substance, (d) disappearance of small dark intramitochondrial granules, (e) depletion of glycogen particles and (f) few dilations in the sarcoplasmic reticulum.
    Type of Medium: Electronic Resource
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    A new approach to mammalian cranial analysis, illustrated by examples of prosimian primates (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 167-179 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Latex endocranial casts, which may be made without damaging the skull, reveal much of the information provided by a hemisected skull. Examination of drawings of endocasts superimposed on skulls may provide insight into the biological significance of skull and brain morphology. The high degree of cranial flexion and the globose brain shape of Daubentonia appear to be related to the functional demands of its gnawing mechanism. The broad frontal lobes of indriids are correlated with orbital orientation; differences in frontal lobe sulcal pattern suggest greater elaboration of the motor filed for the hand in indriids than in lemurids. Several features of lorisid cranial anatomy are discussed. It is suggested that, as a first approximation, increased splanchnocranial declination in small prosimians results from the necessity of accommodating relatively large eyes in a skull with a relatively small splanchnocranium.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051240204
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051240301
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    Further morphological and histochemical studies on the yolk nucleus and associated cell components in the developing oocyte of the indian wall lizard (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 283-293 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In March through April when the oocyte growth in the ovaries of the wall lizard (Hemidactylus) is very rapid, the yolk nucleus continues to persist through various stages of previtellogenesis. This persisting yolk nucleus and associated cell components have been studied with histochemical techniques. The spherical and dense yolk nucleus stains for protein, lipoprotein and RNA. It does not form any close morphological association with the other cell components such as the mitochondria, lipid bodies (L2), spaces or canals, diffuse sudanophilic substance and dense bodies, which are arranged into three zones round the yolk nucleus proper. The mitochondria stain for lipoprotein; the L2 bodies consist of phospholipid; the spaces do not contain any material demonstrable with histochemical techniques; and the ooplasm containing the diffuse sudanophilic substance and dense bodies shows lipoprotein, protein and RNA. Eventually, the yolk nucleus disintegrates, and its substance as well as the other cell components are distributed in the cortical ooplasm of oocytes which are ready to form the yolk bodies.Concepts of the origin, morphology, cytochemistry and function of the yolk nucleus in the oocytes of invertebrates and vertebrates, which have come about recently through the application of cytochemical and submicroscopical techniques, are discussed.
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    URL: http://dx.doi.org/10.1002/jmor.1051240303
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    Symmetrical gaits of dogs in relation to body build (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 353-359 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Symmetrical gaits of 37 breeds of dogs were analyzed. Usual walking and trotting gaits resemble those of other carnivores of similar size and conformation. Only certain long-legged dogs pace - usually at the fast walk or slow run. At the moderate walk, long-legged dogs tend to use lateral-couplets gaits, whereas short-legged breeds tend to use single-foot gaits. Many dogs must turn the axis of the body slightly from the line of travel at the trot to prevent interference between fore and hind feet. The relative duration with the ground made by fore and hind feet is discussed, usual support-sequences of the varicus gaits are presented, and the amount of variation is shown.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051240308
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    H3-proline incorporation into cartilage: Electron microscope autoradiographic observations (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 387-421 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Electron microscope autoradiography was used to study cartilage from regenerating limbs of adult newts, Triturus, after intraperitoneal injections of proline-3H. The labeling in the endoplasmic reticulum, small vesicles, Golgi vacuoles, ground cytoplasm and extracellular matrix was compared during the secretion of radioactive products. The data appear to indicate that a large part of the radioactive secretion probably leaves the cell after having been in only one cellular compartment. Although this compartment may be the endoplasmic reticulum, a considerable amount of radioactivity fluxes through the ground cytoplasm and the possibility cannot be excluded that some secretory components leave the cell directly from the ground cytoplasm. The data appear incompatible with the hypothesis that all the radioactivity seen in the extracellular matrix arrived there via a single pathway involving first the endoplasmic reticulum and then the Golgi vacuoles. It is not, however, incompatible with a hypothesis that a fraction of the radioactive product uses this pathway.
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    Further studies on the development of the eye of Drosophila melanogaster. II. The interommatidial bristles (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 249-261 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An electron microscope examination of the minute bristle organules in the Drosophila eye revealed an organisation characteristic of insect hair sensilla. They were derived from four concentrically arranged cells which were active at the mid-pupal stage in producing the bristle, socket and receptor structures. Two of the cells degenerated towards the end of pupation, the mature organule consisting of a bipolar sense cell and an accessory cell.Growth in length of the bristle was accompanied by a proliferation of longitudinally oriented microtubules which gradually disappeared after maximum growth had been achieved. The breakdown of microfibrillar aggregates, which were also present as transient structures in the developing bristle and showed some correspondence with the longitudinal ridges formed at the surface, may similarly be related to the establishment of cell shape by the deposition of the cuticle which occurred at the same time.
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    URL: http://dx.doi.org/10.1002/jmor.1051240209
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    A histological study of non-follicular cysts in the ovulation fossa region of the equine ovary (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 313-320 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Forty-two unselected ovaries from adult mares were examined histologically, and with histochemical methods for mucins. A considerable part of the surface of the ovulation fossa was directly covered by columnar epithelium, with many ciliated cells. This epithelium, which was distributed mainly on the anterior side of the ovulation fossa, closely resembled the contiguous epithelium of the infundibulum of the oviduct, was frequently folded, and gave rise to short clefts projecting into the ovarian substance. The remainder of the ovulation fossa was covered by non-ciliated, low cuboidal or squamous epithelium, lacking folds or clefts.“Fossa cysts,” up to 6.5 mm in diameter, were observed in the ovarian tissue around the ovulation fossa in 27 (64%) of these ovaries. Both simple and branched, tubular and vesicular forms were present, and all were blind-ending. Their epithelial lining cells, which varied from simple squamous to columnar in type, were frequently ciliated. Many fossa cysts contained secretions histochemically similar to those of the columnar epithelium of the ovulation fossa and infundibulum. Both sialic acidcontaining and neutral mucins were present. It is suggested that these cysts were probably derived by ingrowth from the columnar epithelium of the ovulation fossa. This epithelium may be of müllerian duct origin.
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051240401
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    Studies of a primitive mammalian spleen, the opossum (Didelphis virginiana)This investigation was supported in part by Public Health Service Research grant 5-S01-FR-05409-05 from the National Institutes of Health, General Research Support grant. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 124 (1968), S. 445-450 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light microscopic sections of the adult opossum (Didelphis virginiana) spleen were observed to lack venous sinuses; this primitive mammalian spleen may be classified as non-sinusal in nature. In the spleen of the opossum, the capillary segments of the penicillar arteries lacked ellipsoid sheaths characteristic of certain mammalian spleens.Separating the lymphoid nodules from the surrounding red pulp was a distinct band of vascular tissue, the marginal zone. Arising from the central artery within the lymphoid nodule, vessels of capillary dimension were observed to terminate within the marginal zone and the area between lymphoid nodule and marginal zone. In addition to the vascular channels established by the terminal arterial vessels within the red pulp, the system of vessels within the marginal zone has been implicated as an important intermediate vascular channel within the spleen.
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    URL: http://dx.doi.org/10.1002/jmor.1051240404
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    Formation of septa in the bulbus cordis of a turtle and a lizardA portion of a thesis presented at Harvard University in partial fulfillment of requirements for the Ph.D. degree. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 1-21 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A total of 54 embryos of Chrysemys (Chelonia) and 29 embryos of Aristelliger (Lacertilia) were used in examining septation of the embryonic bulbus cordis. Division of this region of the heart includes a period of cushion or septal primordia formation and a period of physical partitioning. In both reptilian genera, the physical configuration of the early bulbus, the temporal sequence of appearance of the endocardial cushions, the number of major endocardial cushions, the primordia composing the two primary bulbar septa, and the mode of descent of the bulbar septa are strikingly similar. The two genera differ primarily in the pattern of the endocardial cushions and consequently the rotation of the two bulbar septa. In both the turtle and the lizard the aortico-pulmonary septum passes through an angle of about 120° in its descent toward the ventricle. In Aristelliger the aortic septum rotates through an angle of approximately 120°. By contrast, the same partition in Chrysemys spirals through an angle of about 90°. The lesser spiral of this septum in the turtle is interpreted as the result of a decrease in the rotation of distal endocardial ridge 4. The pattern of the two bulbar septa in the turtle appears to represent an advanced phylogenetic feature in terms of the evolution of the reptilian bulbus cordis.
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    Interrelationships between developing oocytes and ovarian tissues in the chiton Sypharochiton septentriones (ashby) (Mollusca, Polyplacophora) (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 71-103 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Oogenesis and the relationships between oocytes and other ovarian tissues have been studied in Sypharochiton septentriones. The ovarian tissues were examined by electron microscopy and by histochemical methods.The sac-like ovary is dorsal, below the aorta, and opens to the exterior by two posterior oviducts. Ventrally, the ovarian epithelium is folded inwards to form a series of plates of tissue, which support the developing ova. Each ovum is attached to a tissue plate by a stalk, the plasma membrane of which is bathed by the blood in the tissue plate sinus. Dorsally, ciliated vessels from the aorta enter the ovary and open into blood sinuses in the top of the plates.After each germinal epithelial cell rounds up to become a primary oogonium, it undergoes four mitotic divisions to give rise to a cluster of 16 secondary oogonia. Of these, the outer ones become follicle cells and the inner ones become oocytes. As in other molluses, the increases in nuclear and nucleolar volume are relatively greatest towards the end of previtellogenesis, when chromosomal and nucleolar activity are most intense. This phase of activity is accompanied by a great increase in cytoplasmic basophilia. Subsequently this basophilia is decreased during vitellogenesis, when chromosomal and nucleolar activity diminish. Fluid filled interstices appear in the cytoplasm during early vitellogenesis. Protein yolk deposition is associated with these interstices, but the lipid yolk appears to arise de novo. The follicle cells do not appear to be directly involved in oocyte nutrition.At times during oogenesis, certain manifestations of polarity can be found in the oocyte. This polarity is based on an apical-basal axis and can be related to the nutritive source of the oocyte, namely the blood which bathes the plasma membrane of the oocyte in the stalk.Numerous granulated cells are present in the ovarian tissue plates and ventral epithelium as storage cells containing lysosomes, and they are capable of phagocytosis and micropinocytosis of extracellular material. A scheme is outlined whereby reserves in these cells may be incorporated into the oocyte cytoplasm. Lysosomal activity is responsible for autolysis of the cells as well as resorption of unspawned ova.
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    The postnatal development of the pelage and ventral gland of the male gerbilThis investigation was supported in part by National Science Foundation grant 05679-248. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 303-313 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The postnatal development of the pelage and ventral gland of male Mongolian gerbils ranging from newborn to 86 days of age was studied. The development of the gerbil pelage follows a pattern similar to that observed for other rodents. The length of the dorsal and ventral skin juvenile hair cycle was found to be 26 to 28 days with a 15 to 18 day anagen and a ten to 11 day catagen and telogen. Hair follicles in the ventral gland began growth ten days later than those of the general pelage and secondary follicles budded from the sides of primary follicles. The ventral gland area differed from the general pelage in that it lacked a panniculus carnosus. The ventral gland is a complex of pilosebaceous glands which, in the adult, fill the entire hypodermis. The length and width of the pilosebaceous canals of the gland units are greater than those of the dorsum. The period of telogen of the hair follicles in the ventral gland is very short. The mid-ventral gland of the male gerbil appears to be a secondary sexual characteristic.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051250304
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051250401
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  • 80
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    Lymphatic capillaries in tail fin of amphibian larva: An electron microscopic studyThis work was supported by USPHS grant AI-07348 and the Shriners Burns Institute, Boston Unit. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 419-445 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of lymphatic capillaries in the tail fin of Rana catesbiana larvae was investigated. With the use of a colloidal marker particle (Biological Carbon) the extent that these delicate vessels ramify throughout the fin region was demonstrated. This opaque substance also serves as a marker particle for identification of lymphatics with some degree of certainty at both light and electron microscopic levels. The cytoplasm of the lymphatic endothelial cell is abruptly attenuated beyond the perinuclear region, reaching widths as thin as 300 Å. Lymphatic Anchoring filaments are present, but to a lesser degree than noted for other species studied. Other features of interest include an extensive Golgi complex and electron dense bodies that are surrounded by a smooth surfaced unit membrane. These bodies are somewhat heterogeneous in size (500 Å up to 0.5 μ in diameter) and density. Numerous exit channels are provided by the extensive supply of lymphatics throughout the tail fin region of amphibian larva thus allowing them to serve an important function during metamorphosis. It is suggested that these vessels also act as passageways through which lysed cellular and connective tissue components may be rapidly removed during the process of tail fin resorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051250404
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  • 81
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    The body wall of cheilostome bryozoa. I. The ectocyst of Watersipora nigra (Canu and Bassler)This work is to be submitted to the graduate faculty of the University of Southern California in partial fulfillment of the requirements for the degree of Doctor of Philosophy. The research, conducted at the University of Southern California, was supported in part by an NIH Biomedical Science Support grant 1-S05-FR-07012-01. Contribution 307 of the Allan Hancock Foundation. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 497-507 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cuticle of Watersipora nigra is at first translucent, but it later becomes black and differentiates into two layers. It is composed, at least in part, of a protein-polysaccharide complex. Calcified parts are three-layered: (1) an outer, cuticular layer, (2) a calcium carbonate skeleton deposited on a matrix of acid mucopolysaccharide, and (3) a “skeletal membrane.” The relationships of these layers indicate that the skeleton is intracuticular. A layer of cuticular material, the “intercalary cuticle” is present in lateral walls, but not transverse walls; it may become calcified in some species. The cuticles of calcified and uncalcified parts of cheilostomes are not necessarily homologous.
    Additional Material: 6 Ill.
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  • 82
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    Morphology of the larval and adult brains of the monarch butterfly, Danaus plexippus plexippus, L. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 67-93 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cell population and neuropile morphology of larval and adult brains of the monarch butterfly, Danaus plexippus plexippus, L., are compared. The larval brain is in continuous transition, the processes of adult brain development being underway from the earliest larval stages. It is characterized by a less diverse population of cells and more homogenous fiber areas than those of the adult. Neuroblasts, which divide to form the neurones of the adult brain, occur either in discrete proliferation centers or scattered among the larval ganglion cells. The larval brain contains, in addition to small homogeneous antennal centers and a distinct larval optic center, rapidly developing adult optic centers, corpora pedunculata, and protocerebral bridge. The larval brain lacks a central body. Major differences between larval and adult brains are clearly related to the increased dependence of the adult upon sensory input from the eyes and antennae.
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  • 83
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    The gonads and sexual cycle of the polystyelid ascidian Distomus variolosus gaertner (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 123-161 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Distomus variolosus from Roscoff, France, comprises two sorts, differing in their branchial and gonadal patterns. Their sexual cycle has been followed histologically and micro-anatomically. Gonads begin as clumps of lymphocytes that persist along germinal tracts. Cavitation of the clump, growth of the gonoduct, maturation of the gametes, and elaboration of accessory structures are described. Oocytes develop in a linear series in each ovary; only one or two reach maturity in each gonad. The released egg and subsequent tadpole may be held to the ovary by a “leash” formed of the partially everted outer follicle of the egg. Post-mature gonads deteriorate. Testes disrupt altogether; ovaries may persist as moribund loci of remnant germinal tissue. The sharp right-left hermaphroditism of the zooid appears to combine with a subtler anterior-posterior gradient of sexual determination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260202
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    Electron microscope studies on developing oocytes of a coelenterate medusa with special reference to vitellogenesisThis investigation was supported by research grants (HD-00699; GM-09229) from the National Institutes of Health, U. S. Public Health Service and a Career Development Award (GM-11,524) from the National Institute of General Medical Science. The author is indebted to Dr. David Epel for providing facilities at the Hopkins Marine Station. The skillful technical assistance of Marlene Decker is also acknowledged. Publication costs provided by an allocation from the Graduate College of the University of Iowa. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 211-247 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In a hydrozoan jellyfish, the female gonad is differentiated from a specialized region of the epidermis near the manubrium. Changes in the oocytes during growth and vitellogenesis are described as observed with electron microscopic and cytochemical techniques. Three major types of yolk are formed; these include lipid, glycogen, and membrane-bound granules consisting of both protein and carbohydrate. The latter first appear evident within vesicular and cisternal elements of the numerous Golgi complexes. The orientation and structural variations noted between the endoplasmic reticulum and forming face of the Golgi complexes suggest that the protein component of the yolk granules may be transferred from the cisternae of the endoplasmic reticulum to the Golgi complex where it is joined to carbohydrate perhaps synthesized by the Golgi complexes. Stages in the release of the precursor yolk material sequestered in cisternal elements of the Golgi complexes are illustrated. The presence of coated and uncoated vesicles in the Golgi regions and their possible role in intracellular transport are described and discussed. The presence and possible method of morphogenesis of vesiculate yolk bodies are also described. What appear to represent invaginations of the oolemma extend into the ooplasm and display a special orientation with respect to lamellae of the rough-surfaced endoplasmic reticulum. Intraooplasmic synthesis appears to constitute the major pathway for protein-carbohydrate yolk deposition.
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    URL: http://dx.doi.org/10.1002/jmor.1051260205
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    A radiological study of the central circulation in the lungfish, Protopterus aethiopicusThis work was supported by grant GB4038 from the National Science Foundation. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 333-348 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The dipnoan heart is only in part structurally developed to support a separated circulation in pulmonary and systemic circuits. In the present investigation biplane angiocardiography has been used to describe the extent of such a double circulation and the factors which may modify it in the African lungfish, Protopterus aethiopicus.Contrast injections in the pulmonary vein revealed a clear tendency for aerated blood returing from the lungs to be selectively dispatched to the anterior branchial arteries giving rise to the major systemic circulation. Contrast injections in the vena cava delineated the sinus venosus as a large receiving chamber for systemic venous blood. Contraction of the sinus venosus discharged blood into the right, posterior part of the partially divided atrial space. Contrast injection in the pulmonary vein showed that vessel to pass obliquely from right to left such that blood was emptied distinctly into the left side of the atrium. During contraction the atrial space tended to retain a residual volume in its anterior undivided part which minized mixing.Ventricular filling occurred through separate right and left atrio-ventricular connections. Right-left separation in most of the ventricle was maintained by the partial ventricular septum, the trabeculated, spongelike myocardium and the mode of inflow from the atria. Mixing in the anterior undivided portion of the ventricle during the ejection phase was slight due to a streamlined ejection pattern.The outflow through the bulbus cordis occurred in discrete streams which in part were structurally separated by well developed spiral folds. In the anterior bulbus segment the spiral folds are fused and make completely separate dorsal and ventral outflow tracts. The ventral bulbus channel provides blood to the three anterior branchial arteries. The second and third branchial arteries are large and represent direct shunts to the dorsal aorta. The fourth and fifth branchial arteries are gill bearing and receive blood form the dorsal bulbus channel. The most posterior epibranchial vessels give rise to the pulmonary arteries.
    Additional Material: 12 Ill.
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    The influence of gonadectomy on sexual characters in the Japanese quailThis investigation was supported in part by NIH Research grants AM-03895 and AM-09926, and NIH General Research Support Grant, and an Institutional Grant from the American Cancer Society. Grants administered by Dr. L. V. Domm. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 395-411 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sinistral ovariectomy in the Japanese quail resulted in some hypertrophy of the rudimentary right gonad in about 80% of the cases. The hypertrophied right gonads were composed of cords of epithelial origin, fat laden cells and a connective tissue stroma containing masses of lymphocytes. Neither cortical tissue nor germ cells were found in any of the gonads. In some cases regeneration of a testis-like tissue was seen on the site of removed left ovary. This, however, did not alter the effects of ovariectomy on rudimentary right gonad, accessory sex organs, plumage or sexual behavior. Neither Wolffian nor Müllerian ducts exhibited hormonal stimulation in poulards showing hypertrophy of right gonad with exception of the latter in two poulards. Early orchiectomy inhibited growth and differentiation of the cloacal gland. This organ revealed no noticeable stimulation in poulards showing hypertrophied right gonads. Castration produced no significant changes in plumage of males. Similarly, sinistral ovariectomy did not effect the first juvenile, but the second juvenile, adult winter and summar plumages changed to the male type. However, the plumage of some of these poulards began to revert to the female character as early as 10 to 12 weeks following ovariectomy. The behavior of capons and poulards revealed no conspicuous difference and neither showed any masculine behavior. The average weight of adult females was 20 to 30 gm above that of adult males whereas that of capons was above normal males and that of poulards below normal females. The average weight of capons was somewhat above that of poulards.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051260403
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    Some histochemical and biochemical observations on the lymphatic tissues of highly inbred white Leghorns (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 281-301 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Lymphatic tissues of inbred lines of White Leghorn chickens and 20-day embryos (inbreeding coefficient exceeds 95%) were used in the experiments, e.g. line 6 was susceptible, line 7 was resistant, and line 15 I was intermediate in response to the virus. Enzyme reactions were studied in cryostat-cut sections of tissues and in tissue minces by colorimetric procedures. Numbers of isozymes and proteins of lymphatic tissues were resolved by disc gel electrophoresis.Colorimetric tests showed that intensities of lactate, malate, isocitrate and succinic dehydrogenase catalyzed reactions were higher in the bursae of 15 I 20-day embryos than they were in bursae of either line 6 or 7 embryos. Intensity of dehydrogenase reactions of the spleen (15 I embryos) exceeded that found in line 6 and 7 embryos. Intensity of diaphorase reactions in the spleen and thymus was fairly uniform in all lines of embryos. Intensity of DPN diaphorase reactions in the bursae of line 15 I embryos exceeds that found in either line 6 or 7 embryos. Intensity of enzyme reactions leveled off to become fairly uniform in lymphatic tissues of chickens 3-4 weeks post hatching with the exception that dehydrogenase reactions were less intense in the thymus of 15 I chickens.Photodensitometer scans of acrylamide gel columns showed that proteins of line 6 lymphatic tissues combined with less Amido black 10B than lymphatic proteins of either line 15 I or 7 embryos. There was fairly good agreement between concentrations of strong mobility (components 1-9) and weak mobility (components 10-16) in lymphatic tissues of all lines of embryos with the exception that strong mobility proteins were about twice as concentrated in line 15 I bursae. Variable numbers of lactate isozymes were found in the lymphatic tissues of 20-day embryos.
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    The reproductive morphology of Cnemidophorus neomexicanus X Cnemidophorus inornatus hybrid males (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 367-377 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of the gonads and epididymides, and an analysis of selected scale characters of six hybrid males presumed to be the result of the natural mating of the all-female whiptail lizard species Cnemidophorus neomexicanus and the bisxual species C. inornatus are presented. The histological appearance of the gonads and epididymides reveals a seasonal cyclicity with respect to the production and storage of spermatogenic elements. On the basis of the limited sample, it is postulated that some abnormality may be present in gametogenesis of these hybrid males which could be related to their chromosomal number. The data on scale characters support the interpretation that these hybrids are intermediate with respect to the parental species.
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    URL: http://dx.doi.org/10.1002/jmor.1051250307
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    Regeneration of the completely excised gastrocnemius muscle in the frog and rat from minced muscle fragmentsSuported in part by Institutional Research grant IN-40H to the University of Michigan from the American Cancer Society. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 125 (1968), S. 447-471 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In 85 frogs and 29 rats, the entire gastrocnemius muscle was removed. After removal of as much connective tissue as possible, about two-thirds of the remaining muscle was finely minced with a scissors. These minced fragments were orthotopically re-implanted, and the overlying skin was sutured. As the implanted muscle fragments degenerate, new muscle fibers appears in the regenerate. The proportion of connective tissue to muscle is usually greater than normal especially in the frog. Grossly, normal relationships are established with the cut ends of the Achilles and proximal tendons, as well as with the blood vessels and nerves. The total diameter of the regenerated muscle is almost always less than half of that seen in normal muscles. Regeneration of muscle is much more extensive in the rat than in the frog, and it occurs almost twice as rapidly. The histology of the regenerative process is described for both the frog and the rat.
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    URL: http://dx.doi.org/10.1002/jmor.1051250405
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    In vitro myogenesis of promuscle cells from the regenerating tail of the lizard, Anolis carolinensisA portion of a dissertation submitted to the Department of Biology, Case Western Reserve University, in partial fulfillment of the requirements for the degree of Doctor of Philosophy.,This work was supported by NIH grant GM 12654 to Dr. S. B. Simpson, Jr., Department of Anatomy, School of Medicine, Case Western Reserve University. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 1-17 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Presumptive myoblasts from the regenerating tail of the lizard plated at clonal density undergo extensive growth giving rise to large colonies. After several days in culture at 31°C some of the cells begin to round up and assume a spherical morphology. The number of rounded up cells increases over the next few days until 50 to 75% of the cells are rounded up. If the cultures are switched to a permissive medium, fusion and differentiation occur. If they are left in a nonpermissive medium fusion does not occur. Instead, the cells stretch out on the substrate and become long and attenuated or broad and strap-like. However, differentiation may continue in some of the cells giving mononucleate cells with cross striations. Autoradiographic studies indicate that the rounded up cells represent a post-synthesis, prefusion population of cells.
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    The adult cervicothoracic musculature of the cockroach, Nauphoeta cinerea (Olivier) (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 107-122 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cervicothoracic musculature of the adult cockroach, Nauphoeta cinerea (Olivier) is described for the first time. The adult thoracic ventral intersegmental muscles are compared with those of the nymph and of the adult cockroach, Periplaneta americana (Linnaeus).
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    Thoracic structure of the adult mecopteron, Bittacus strigosus Hagen (Mecoptera: Bittacidae) (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 199-210 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The thoracic skeleton and musculature of the adult bittacid mecopteron Bittacus strigosus Hagen is described. In its musculature, Bittacus shows only moderate differences from two panorpids (Neopanorpa, Panorpa) that have been studied by Maki ('38) and by Hasken ('39), respectively. Not only are these three genera much alike in their musculature generally, but in all of them, and in Boreus (Boreidae) too, the mesothorax is extremely similar to the metathorax. Functional emphasis (for flight) on either of the two pterothoracic segments has not appeared among neuropteroid insects at the metopteran evolutionary level.Although the “snowfleas” of the genus Boreus possess striking alterations of pterothoracic structure in comparison with other mecopterons (Füller, '54, '55), these are related to their unusual activities and have not, to any great extent, affected the two pterothoracic segments differentially.In terms of thoracic specialization, the overall mecopteran pattern represents a stage somewhat advanced beyond the primitive conditions exemplified by the Megaloptera and certain coleopterous larvae, but one that is in general less highly developed than is charatceristic of such neuropteroid orders as the Siphonaptera, Diptera, Trichoptera, and Lepidoptera.
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    URL: http://dx.doi.org/10.1002/jmor.1051260204
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    Evolutionary morphology of the caecilian urogenital system. I. The gonads and the fat bodiesThe following is a portion of a dissertation presented in partial fulfillment of the requirements for the Ph.D. degree at the University of Southern California, Los Angeles, California. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 291-331 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The comparative morphology of the gonads and fat bodies of members of 17 genera and 46 species of caecilians (Amphibia: Gymnophiona) is described and analyzed. Comparison is made with the morphology of salamanders and frogs in order to elucidate evolutionary trends and relationships within the order Gymnophiona and within the class Amphibia. The structure of the testis lobes and transverse and longitudinal ducts is described based on gross dissection and histological investigation. The pattern of spermatogenesis and interstitial tissue changes are described and compared with those of other amphibians. A trend toward fusion of testis lobes is analyzed. The characteristics of the seasonal reproductive cycle of male Gymnopis m. proxima are described, and evidence for cyclic reproductive activity in other forms is presented. The morphology of the ovaries and ova is described. Size of ovary and size and number of ova is dependent on the state of maturation of the ova. Some evidence for seasonal ovum production and breeding is presented. Fat body morphology is found to be correlated with size, nutrition, and gonad condition, as in other amphibians.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260303
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    Masthead (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260401
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    Comparative histochemical investigation of the organ of corti in the kangaroo rat, gerbil, and guinea pigThis research was supported by grant NB 05800 from the National Institutes of Health. The authors gratefully acknowledge the technical assistance of R. J. Melker and M. B. Webster. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 413-433 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution of carbohydrates, proteins, and lipids was studied in the cochleae of kangaroo rat, gerbil, and guinea pig using both fixed paraffin sections and fresh-frozen cryostat sections. Enzyme distribution in the cochleae of the three speices was studied with both EDTA-decalcified and undecalcified fresh-frozen cryostat sections.Although the cochleae of the three species are morphologically different, their distributions of proteins, carbohydrates, and lipids are similar. The zona pectinata of the basilar membrane - which is hypertrophied in the kangaroo rat and gerbil but normal in the guinea pig - stains the same in all three species. The unique, flaskshaped Hensen cells of the kangaroo rat contain more protein than do the normal Hensen cells of the gerbil and guinea pig. At least some of the protein in the kangaroo rat Hensen cells is in the form of carboxylic esterases which are not affected by 10-4 M eserine, but are inhibited by 10-2 M eserine and 10-6 M E600. More than one population of carboxylic esterases is indicated by this reaction to inhibitors and by the results of enzyme distribution tests which used different substrates. A high concentration of malate dehydrogenase in the kangaroo rat Hensen cells may be related to the synthesis of carboxylic esterases. The possible role of these esterases in cochlear functioning is discussed.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260404
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  • 96
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    Lymphomyeloid organs of amphibia. IV. Normal histology in larval and adult Rana catesbeianaThis research was supported by American Cancer Society Research grant E-492 and National Science Foundation Research grant GB-7607 to E. L. Cooper. (1968)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 126 (1968), S. 463-475 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This report presents light microscopic descriptions of normal histology, including innervation, of the lymph glands and jugular bodies, of larval and adult Rana catesbeiana. A brief description of two other adult organs, the propericardial and procoracoid bodies, is also included. The parenchyma was studied by employing the May-Grunwald-Giemsa staining technique for better cytoplasmic differentiation; the Periodic Acid-Schiff technique and hematoxylin and eosin yielded clearer nuclear and cytoplasmic delineations. The intercellular portion of the stroma was studied from sections stained with Masson's trichrome, Weigert's elastic stain, Periodic Acid-Schiff and Wilder's reticulum stain. Demonstration of phagocytes was facilitated by intraperitoneal India ink injections followed by the above staining procedures. Innerrvation was observed in serial sections of silver impregnated whole organs as well as in the other serial sections. These organs are lymphocytopoietic and to a certain extent granulopoietic; they also serve, like the spleen, as graveyards for dead cells and most probably play a role in immunity especially in the synthesis of antibodies as indicated by the presence of plasma cells, macrophages and lymphocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051260407
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  • 97
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    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
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  • 98
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    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
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  • 99
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    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
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  • 100
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    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
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