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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 34 (1975), S. 111-119 
    ISSN: 1432-0738
    Keywords: 2,21,4,41,5,51-Hexachlorobiphenyl ; Autoradiography ; Bronchi ; 2,21,4,41,5,51-Hexachlorobiphenyl ; Autoradiographie ; Bronchien
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Verteilung von 2,21,4,41,5,51-hexachlorobiphenyl-14C wurde an Mäusen und chinesischen Hamstern studiert, wobei Ganz-Tier-Autoradiographie und Flüssigkeits-Scintillations-Zählung verwendet wurden. Die Mäuse zeigten eine starke und lange persistierende Anhäufung von Radioaktivität in der Bronchialschleimhaut. Diese Anhäufung trat vollständig erst 24 Stunden nach einer intravenösen Injektion auf. Die radioaktive Substanz erreichte die Föten trächtiger Mäuse und fand sich auch in den fötalen Bronchien konzentriert. Mäuse, die mit einer großen Dosis von unmarkierten PCB per os in Erdnußöl vorbehandelt worden waren, zeigten ein völlig verschieden geartetes Verteilungsmuster in den Lungen — die Bronchien nahmen nur Spuren der markierten Substanz auf. Quantitative Messungen zeigten eine gleichzeitige Reduktion der von den Lungen zurückbehaltenen totalen Radioaktivität. Mit Ausnahme der Lungen wurden jedoch bei den verschiedenen Dosen keine großen Unterschiede im Verteilungsmuster gefunden. Die chinesischen Hamster wiesen die gleiche Verteilung wie die Mäuse auf. Es wurde aber nur eine sehr geringe Anhäufung der markierten Substanz in den Hamsterbronchien beobachtet. Die Radioaktivität in den Mausbronchien kann von metabolisiertem PBC stammen.
    Notes: Abstract The distribution of 2,21,4,41,5,51-hexachlorobiphenyl-14C was studied in mice and Chinese Hamsters using whole body autoradiography and liquid scintillation counting. The mice exhibited a strong and persistent accumulation of radioactivity in the bronchial mucosa, and this accumulation was not fully developed until about 24 hrs after an intravenous injection. The labelled substance passed to the fetuses of pregnant mice and was also concentrated in the fetal bronchi. Mice pretreated with a large dose of unlabelled PCB per os in peanut oil showed a completely different distribution pattern in the lungs — only traces of label being taken up by the bronchi. Quantitative measurements revealed a concomitant reduction of the total radioactivity retained by the lungs. Except for the lungs, however, no major differences in the distribution pattern were found at the various dose levels. The distribution in the Chinese hamsters equaled approximately that of the mice, but a very weak accumulation of label was observed in the hamster bronchi. The radioactivity in the mouse bronchi was considered as perhaps representing metabolized PCB.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 13 (1975), S. 493-507 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Water vapor transport properties for the polymers Kapton HReference to a company or product name does not imply approval or recommendation of the product by the University of California or the U.S. Atomic Energy Commission to the exclusion of others that may be suitable. and Parylene C were determined over a temperature range of 20 to 55°C. Activation energies and entropies for permeation as well as partial molar free energies, heats, and entropies of dilution were calculated for water vapor concentrations ranging from 3 × 10-6 to 1 × 10-3 mole H2O per cm3 of polymer. Mylar A was tested to extend the available data for partial molar heats and entropies of dilution and to compare permeation and diffusion results with the corresponding values in the literature. Diffusion coefficients were measured using the time-lag technique of Barrer but employing a modified test apparatus. Equilibrium sorption isotherms at 30°C were obtained for Mylar A and Kapton H with a Cahn microbalance. The ratios of the permeability to diffusion coefficients as measured from time-lag experiments agreed with solubility coefficients within 3% for Mylar A and within 12% for Kapton H. Both polymers obeyed Henry's law. The results were interpreted in light of polymer polarity and morphology.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 991-1019 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Surfaces of polymers [polyethylene, polystyrene, poly(ethylene terephthalate), poly(oxymethylene), cellulose acetate, polyacrylonitrile, nylon 6, and polytetrafluoroethylene] treated with argon (inert) and nitrogen (reactive) plasma were examined by ESCA (electron spectroscopy for chemical analysis). Argon plasma treatment generally introduces oxygen functionalities into the polymer surface. Nitrogen treatment generally incorporates nitrogen and oxygen functionalities into the treated surface. The extent of oxygen incorporation is typically less than that produced by argon plasma. When nitrogen and oxygen functional groups are already in a polymer structure, the extent of additional incorporation of these two elements as a result of plasma treatment is very much less than with other polymers. Polymers which contain only one of the elements tend to incorporate the other element to much the same degree as polymers without either element initially present.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 415-425 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma polymerizations of ethylene and tetrafluoroethylene are compared. In the plasma polymerization of ethylene and of tetrafluoroethylene, glow characteristics play an important role. Glow characteristic is dependent on a combined factor of W/Fm, where W is discharge power and Fm is monomer flow rate. At higher flow rates, higher wattages are required to maintain “full glow.” In the plasma polymerization of tetrafluoroethylene, simultaneous decomposition of the monomer competes with plasma polymerization. Above a certain value of W/Fm, decomposition becomes the predominant reaction, and the polymer deposition rate decreases with increasing discharge power. ESCA results indicate that the plasma polymer of tetrafluoroethylene that is formed in an incomplete glow region (low W/Fm) is a hybrid of polymers of plasma polymerization and of plasma-induced polymerization of the monomer. Polymers formed under conditions of high W/Fm to produce “full glow” are similar, regardless of the extent of decomposition of the monomer. They contain carbons with different numbers of F(CF3, —CF2—, 〉CF—, 〉C〈) and carbons bonded to other more electronegative substituents.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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