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  • 2005-2009
  • 1980-1984  (4)
  • 1965-1969
  • Physics  (3)
  • Catheterisation  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Surgical and radiologic anatomy 4 (1982), S. 279-284 
    ISSN: 1279-8517
    Keywords: Portal vein ; Umbilical vein ; Catheterisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Complétant un travail antérieur de l'anatomie macroscopique et histologique de la veine ombilicale de l'adulte, une étude histologique et radiologique a été faite sur des cadavres afin de déterminer le trajet suivi par des sondes ou des cathéters introduits dans cette veine afin d'obtenir un accès sur le système porte. Bien qu'il persiste une partie de la lumière initiale, son diamètre est trop étroit (approximativement 0,2 mm) pour admettre des sondes et des cathéters. Les instruments se fraient un passage artificiellement à travers une zone interne lâche qui est la ≪lumière apparente≫ de la veine. Cette zone centrale qui est formée après la naissance est plus pâle et de consistance moins ferme que les zones périphériques mais elle devient plus fibreuse avec les années et sa reperméabilisation est alors plus difficile. A la jonction veine ombilicale-veine porte, la sonde est arrêtée par la paroi de la branche gauche de la veine porte qui se divise à ce niveau (récessus ombilical). Une perforation de cette paroi par pression de la sonde permet de pènètrer dans le système porte. Sans une reperméabilisation préalable, l'injection de liquide de contraste dans la lumière apparente de la veine ombilicale ne pénètre pas dans le système porte.
    Notes: Summary Following a previous study of the gross anatomical and histological features of the adult umbilical vein, a histological and radiological investigation has been made on post-mortem material, to determine the route taken by probes and catheters introduced into the hemisected vein, to obtain access to the portal system. Although a residual part of the original lumen persists, it is far too small in diameter (approximately 0.2 mm) to admit probes and catheters. The instruments traverse a loose inner zone (the ‘apparent lumen’) and form a false passage within it. This zone, which is formed postnatally, is paler and of softer consitency than the surrounding zones, but since it becomes more fibrous and contracted in later life, instrumentation could prove more difficult in the elderly. At the umbilical-portal junction, the probe is arrested by the diverging right wall of the terminal expansion of the left branch of the portal vein (the recessus umbilicalis). Local rupture of the inner part of the wall by probe pressure gives access to the portal system. Without prior probing, contrast medium injected locally into the apparent lumen does not reach the portal system.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 89-101 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(p-phenylene) was alkylated with n-propyl bromide, n-propyl chloride, and isopropyl bromide in the presence of aluminum chloride. Apparently, the reactions involve dialkylation with n-propyl halides and alternating mono- and dialkylation with isopropyl bromide. Alkylation with ethyl or n-butyl bromide was unsuccessful. The dialkylated polymer was sufficiently soluble to allow molecular weight determination. Mechanistic aspects of alkylation and propagation are treated.
    Additional Material: 2 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 19 (1981), S. 235-244 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radical cation nature of poly(p-phenylene) (PPP) was examined by electron spin resonance (ESR) and chemical means. ESR studies revealed a radical concentration of 1.0 × 1021 spins/g for the crude polymer. Workup with aqueous acid decreased the value to 1.5 × 1018 spins/g. Reactions of the polymer with certain nucleophiles followed the half-regeneration mechanism, whereas with others, electron transfer mainly occurred. The origin of halogen in the polymer was found to arise from reaction of the radical cation with the oxidant, and not with halide during workup. Oxidation of PPP with various species increased the concentration of radical cations.
    Additional Material: 1 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 19 (1981), S. 973-984 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chlorobenzene and toluene were polymerized with aluminum chloride-cupric chloride to produce materials that consist mainly of poly(o-phenylene) structures. These species exhibited radical cation concentrations comparable to that of poly(p-phenylene). Polymerization of naphthalene and 1-chloronaphthalene with aluminum chloride-cupric chloride or ferric chloride-water also resulted in products with high radical cation concentrations. Polynuclear structures may be responsible for the paramagnetic character; alternatively, p-quinoidal moieties may be present in naphthalenes. The depth of color in the samples is directly related to the concentration of radical cations.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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