Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Polymer and Materials Science  (3)
  • ischemia  (3)
  • Induced pinocytosis  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Pinocytosis and locomotion in amoebae (1979)
    Springer
    Protoplasma 100 (1979), S. 33-43 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Amoeba proteus ; Ca++-binding sites ; Cytochemical demonstration ; Induced pinocytosis ; Plasma membrane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Different methods were used to demonstrate the existence of Ca++-binding sites (Ca++-bs) at the plasma membrane ofAmoeba proteus. In pinocytoting animals the number (indicated by the average distanced in nm) and size (average longitudinal axiss in nm) of Ca++-bs at the cytoplasmic surface of the cell membrane were significantly increased (d=162±15;n=41 ands=93±5;n=47) in comparison to controls (d=208 ±21;n=37 ands=59±8;n=45). The ratio of P: Ca obtained by X-ray microanalysis was in the range of 1.5. The differences observed in the two experimental groups of amoebae are explained by conformational changes in the molecular structure and an increased Ca++-permeability of the plasma membrane during induced pinocytosis. Microplasmodia of the acellular slime moldPhysarum polycephalum investigated for comparison were found to have no Ca++-bs at the interior cell surface.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01276299
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Temporal and spatial development of infarcts in porcine hearts (1984)
    Springer
    Basic research in cardiology 79 (1984), S. 440-447 
    Details
    ISSN: 1435-1803
    Schlagwort(e): myocardium ; ischemia ; infarction ; reperfusion ; pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We investigated the temporal and spatial development of infarcts in porcine hearts to evaluate the time-dependent beneficial effect of reperfusion on infarct size. The left anterior descending coronary artery (LAD) was occluded in 17 pigs for different periods of time followed by 4 hours of reperfusion. Transmural needle biopsies subdivided into subendocardial and subepicardial halves were taken from the ischemic apex after 60 min of ischemia to determine the tissue concentrations of ATP and NAD. The myocardium-at-risk was assessed with a fluorescent dye injected into the right atrium at the end of the experiments, just after the LAD had been reoccluded. The excised hearts were cut into slices parallel to the heart basis. The ischemic myocardium was measured by planimetry of the nonfluorescent areas whereas the infarcted tissue was determined with the NBT stain and related to the area-at-risk. Ischemic cell death started in the jeopardized left ventricular subendocardial septum after about 30 min of ischemia. The further progress involved the right subendocardial septum and the subendocardium of the left anterior free wall. Already after 75 min of ischemia most of the myocytes-at-risk were irreversibly injured. Infarctions reached their final extent after 90–120 min of ischemia. These results indicate that in hearts without a significant collateral blood flow reperfusion can only reduce infarct size if its initiated within 60–75 min of ischemia. Like in canine hearts infarctions progress from the ischemic subendocardium towards the outer layers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01908144
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Acute treatment with vitamin E does not protect the regionally ischemic, reperfused porcine heart (1991)
    Springer
    Basic research in cardiology 86 (1991), S. 32-39 
    Details
    ISSN: 1435-1803
    Schlagwort(e): ischemia ; reperfusion ; vitamin E ; infarct size ; regionalsystolic shortening
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Thirty pigs were randomly assigned to a blind treatment with vitamin E or placebo. Ten animals each received 0.5g d-alpha tocopherol intravenously before ischemia (group 1) or before reperfusion (group 2). Ten control pigs were treated with a lipid emulsion as placebo. The left anterior descending coronary artery was distally ligated for 45 min followed by 3 days of reperfusion. Infarct size was determined as ratio of infarcted (tetrazolium stain) to ischemic myocardium (dye technique). Regional systolic shortening was assessed by sonomicrometry. Myocardial and plasma concentrations of vitamin E were determined by high-performance liquid chromatography. Global hemodynamic parameters and estimated left ventricular oxygen consumption did not differ among the three groups. Intravenous treatment with vitamin E raised the plasma levels of this vitamin from 1 ± 0.3 mg/l (control group) to 21 ± 6 mg/l before ischemia, to 4 ± 2 mg/l before reperfusion and to 2 ± 0.6 mg/l at the end of the experiments in group 1. In group 2, vitamin E plasma levels increased from 1 ± 0.3 mg/l to 24 ± 13 mg/l before reperfusion and to 2 ± 0.6 mg/l after 3 days of reperfusion. At the end of the experiments, myocardial vitamin E concentrations amounted to 4.2 ± 0.7 ng/mg fresh weight (control group), 9.7 ± 2.1 ng/mg (group 1), and to 8.7 ± 1.4 ng/mg (group 2). The increase in vitamin E plasma concentration was not associated with a cardioprotective effect. Infarct sizes of the three groups (group 1: 68 ± 12%, group 2: 66 ± 15%, control group: 69 ± 8%) were almost identical. Furthermore, recovery of systolic shortening was not improved by the acute vitamin E treatment. Mean systolic shortening of the reperfused segment amounted to 4% in the two treatment groups and 3% in the control group after 3 days of reperfusion. These results suggest that an acute increase in vitamin E plasma concentration before ischemia or during the early phase of reperfusion does not protect the ischemic, reperfused porcine heart.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02193869
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Intracoronary hyperosmotic mannitol during reperfusion does not affect infarct size in ischemic, reperfused porcine hearts (1985)
    Springer
    Basic research in cardiology 80 (1985), S. 251-259 
    Details
    ISSN: 1435-1803
    Schlagwort(e): mannitol ; ischemia ; reperfusion ; infarct size ; pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We investigated the effect of reperfusion with hyperosmotic mannitol on the infarct size in porcine hearts. The distal half of the left anterior descending coronary artery was occluded in each of 21 anesthetized pigs for 75 min and was reperfused for 2 h. During reperfusion mannitol (1075 mosmol/kg) was intracoronarily infused at a dose of 0.5 ml/min in 6 pigs (“low” mannitol group), at a dose of 1.5 ml/min in another 6 pigs (“high” mannitol group), and at a dose of 5 ml/min in 3 pigs for the first 8 min of reperfusion (“very high” mannitol group). 6 pigs served as controls. Although mannitol infusion increased plasma osmolality in the ischemic, reperfused myocardium in all experiments, the infarct size expressed as the ratio of the infarcted tissue over the area at risk of necrosis was not significantly influenced. Infarct size amounted to 72±25% in the control group, to 75±14% in the “low” mannitol group, to 78±18% in the “high” mannitol group, and to 93±8% in the “very high” mannitol group. These results clearly indicate that reperfusion with hyperosmotic mannitol after 75 min of ischemia does not exert any beneficial effect on the infarct size.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01907901
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Determination of Stress Tensors in thin textured copper films by grazing incidence diffraction (1995)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 26 (1995), S. 553-559 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Bestimmung der Spannungstensoren in dünnen, texturierten Kupferschichten mittels Röntgenbeugung bei streifendem EinfallIonenplattierte Kupferschichten wurden mittels Röntgenbeugung hinsichtlich Texturen und Eigenspannungen untersucht. Die vollständigen Orientierungsverteilungsfunktionen wurden bestimmt und scharfe (111)-Fasertexturen gefunden. Die Messung der Dehnungen erfolgte unter streifendem Strahleinfall. Zur Berechnung der Spannungstensoren wurden sowohl texturgewichtete elastische Moduln als auch texturunabhängige elastische Moduln verwendet. Die Bedeutung der Texturmessung für die Spannungstensorbestimmung wird diskutiert. Die gefundenen Spannungen können als thermisch verursacht verstanden werden.
    Notizen: Ion-platted thin copper films were examined for residual stresses and texture by X-ray diffraction. The complete orientation distribution functions were determined and sharp (111)-fibre textures were found. The strains were measured by grazing incidence diffraction. The stress tensors were calculated using both texture-weighted elastic compliances and texture-independent X-ray elastic constants. The importance of the texture measurement for the stress tensor determination is discussed. The found stresses can be interpreted as thermally induced.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19950261012
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Pinocytosis and locomotion of amoebae: XII. Dynamics and motive force generation during induced pinocytosis in A. proteus (1979)
    Springer
    Cell & tissue research 197 (1979), S. 263-279 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Induced pinocytosis ; Dynamics ; Motive force generation ; Light and electron microscopy ; Amoeba proteus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The mechanism of induced pinocytosis was investigated in Amoeba proteus by light and electron microscopy. The application of nine different inducing substances revealed that pinocytotic channel formation, elongation, vesiculation, shortening and disappearance are the result of the successive or simultaneous action of both traction and pressure forces, which are produced by the contractile activity of a plasma membrane-associated layer of filaments ranging from a few hundred nm to several μ in thickness. The initial phase of channel formation is caused by traction forces according to the membrane flow concept, whereas channel elongation and vesiculation mainly result from pressure forces in conjunction with the extrusion of small hyaline pseudopodia. Shortening and disappearance of the pinocytotic channels are brought about by local contractions of the cortical filament layer in the basal region of the hyaline pseudopodia. Experiments using latex beads as marker particles together with inducing substances show that a rapid membrane turnover during pinocytosis can be excluded, and that the plasma membrane slides as an entire structure over the underlying cytoplasm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233919
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    O-Phthalsäuredialkylester als PVC-weichmacher (1955)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 16 (1955), S. 1-9 
    Details
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: 38 Dialkylesters of o-phthalic acid are examined as plasticizers for polyvinyl chloride. The plasticizer efficiency is determined by means of dielectric measurements for the molar plasticizer concentration c = 0.1. In the case of isomeric esters the n-alkylesters always have the highest plasticizer efficiency while with the n-alkylesters the efficiency increases proportionally with the length of the alkyl chain. The influence of chain length and branching of the alkylgroup also shows itself in the viscosity of the pure plasticizer. From the graphical representation of the relationship between plasticizer efficiency Δ T and viscosity η conclusions may be drawn concerning the structure of the alkyl groops.
    Notizen: 38 o-Phthalsäuredialkylester werden als Weichmacher für Polyvinylchlorid (PVC) untersucht. Die Weichmacher-Wirksamkeit wird, wie in früheren Arbeiten, mit Hilfe dielektrischer Messungen bestimmt, für die molare Weichmacher-Konzentration c = 0,1. Bei isomeren Estern hat der n-Alkylester immer die höchste Weichmacher-Wirksamkeit und bei den n-Alkylestern steigt die Weichmacher-Wirksamkeit mit der Länge des Alkyls linerar an. Die Länge und Verzweigung des Alkyls macht sich auch in der Viskosität des reinen Weichmachers bemerkbar. Die Kombination von Weichmacher-Wirksamkeit Δ T und Viskosität in dem Diagramm Δ T = f (η) führt zu Hinweisen auf den strukturellen Aufbau der Alkyle.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/macp.1955.020160101
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Microcomputers in small injection molding machines - operation and design (1984)
    Hoboken, NJ : Wiley-Blackwell
    Advances in Polymer Technology 4 (1984), S. 51-60 
    Details
    ISSN: 0730-6679
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: Modern, trend-setting small injection molding machines should be designed so that they open up new applications to the plastics processor through utilization of microelectronics. In the sector of control, it would be equivalent to stagnation if only the familiar functions were realized with modern control circuits of a higher integration level and if the possibilities of these modules were not utilized to simplify operation, to expand the technological possibilities, and to illustrate the sequences of processes. The mechanical and hydraulic designs should be adjusted to these requirements.The design and extent of the electronic control system should be such as to ensure an economically reasonable relation between extra price and additional benefit - a basic requirement for offering standard supplies.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/adv.1984.060040105
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...