Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 189 (1988), S. 2823-2837 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The commercially available poly(1-octenylene) Vestenamer® formed by the metathetic polymerization of cyclooctene with a tungsten catalyst, is highly crystalline at room temperature; it shows specific properties as a blend component, thus favourably influencing the processing characteristics and the final product quality. Differential scanning calorimetry, infrared and torsion pendulum experiments indicate that the melting temperature and the degree of crystallinity depend on the concentration of trans double bonds, on their distribution along the polymer chain as well as on the sample history. The formation of crosslinks induced by very intensive UV irradiation of 100 μm thin films leads to a reduction of the melting temperature and the crystallinity. A correlation between stiffness (shear modulus G′) and crystallinity was found for samples with varying amounts of trans double bonds.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Measurements of small-angle x-ray scattering have been made on films prepared from fine and coarse (i.e., formed at high and low, respectively, pH and ionic strength) clots of bovine fibrin by osmotic shrinkage or compression in one dimension. Intensity profiles were obtained with pinhole geometry on films stretched up to a stretch ratio of 1.43. In unstretched coarse films, repeat spacings were seen at about 245, 120, and 77-80 Å. These peaks can probably be identified with the first, second, and third orders of the well-known fibrin repeat of 225 Å. In unstretched fine films, only the 77-80 Å spacing was seen. In this case, the first two orders may be weak because the half-staggered arrangement of monomer units giving rise to the 225 Å reflection is not reinforced by lateral aggregation of protofibrils; the third order may be strong since the molecular subdomains appear to divide the repeat roughly into thirds. After stretching, the 77-80 Å spacing persisted in the meridional direction but almost disappeared in the equatorial. Experiments on unstretched films prepared with ancrod substituted for thrombin gave similar results.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mechanical creep and creep recovery in small shearing deformations have been studied in unligated clots formed with both thrombin and ancrod. In thrombin clots, both A binding sites (which interact with “a” sites to link monomer units within a protofibril) and B sites (which interact with “b” sites to form links between protofibrils) are exposed to enable formation of linkages; in ancrod clots, only the A sites are exposed. Fine clots (with minimal lateral aggregation of protofibrils), coarse clots (with substantial aggregation of fibril bundles), and clots of intermediate coarseness were compared. Fine thrombin clots showed less creep at short times but more creep at long times than coarse or intermediate clots and had more irrecoverable deformation relative to the initial elastic deformation. Ancrod clots had greater irrecoverable deformation than the corresponding thrombin clots, both fine and coarse. The permanent deformation in fine ancrod clots was enormous, corresponding almost to fluid character; the rate of permanent deformation was larger than that in fine thrombin clots by more than two orders of magnitude. For all types of clots, differential measurements of compliance (or its reciprocal, elastic modulus), as well as the applicability of the Boltzmann superposition principle to calculation of creep recovery, showed that the overall density of structure remained constant throughout the mechanical history; i.e., if structural elements were breaking, they were reforming at the same rate in different configurations. The possibility that the weakness of ancrod clots is attributable to partial degradation of α-chains rather than absence of Bb linkages was eliminated by comparisons of clots made with thrombin, ancrod, and ancrod plus thrombin; the last two showed identical partial degradation of α-chains (by gel electrophoresis), but the first and third had essentially identical initial elastic moduli and creep behavior. Two alternative mechanisms for irrecoverable deformation in fine clots are discussed, involving rupture of protofibrils and slippage of twisted segments, respectively.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1989 (1989), S. 367-374 
    ISSN: 0170-2041
    Keywords: Concave base ; 1,10-Phenanthroline ; Macrobicyclic lactam ; Template cyclization ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Konkave Reagenzien, 2. - Makrobicyclische 1,10-PhenanthrolineDrei makrobicyclische 2,9-disubstituierte 1,10-Phenanthrolin-bislactame 4 wurden mit Gesamtausbeuten bis zu 43% synthetisiert. Dabei wurden zwei Makrocyclisierungstechniken angewandt: 1) Eine Metallionen-gesteuerte Biskondensation (Templatsynthese) eines Diamins 6 mit 1,10-Phenanthrolin-2,9-dicarbaldehyd (5) führte zu neuen makrocyclischen 1,10-Phenanthrolin-Diimin-Komplexen 7 (Schiff-Basen, als Pb2⊕-Komplexe isolierbar), die durch Reduktion mit NaBH4 in die makrocyclischen Diamine 8 übergeführt werden konnten. 2) Die makrocyclischen Diamine 8 wurden mit Dicarbonsäuredichloriden 9 nach dem Verdünnungsprinzip zu den Makrobicyclen 4 umgesetzt. - Die Synthesen der Bicyclen 4, ihre Reaktionen mit Cu⊕ und die relativen Basizitäten von 4 und Vergleichsverbindungen in Ethanol werden beschrieben.
    Notes: Three macrobicyclic 2,9-disubstituted 1,10-phenanthroline-containing bislactams 4 were synthesized in overall yields of up to 43%. Two successive macrocyclization techniques were used: i) metal ion template-assisted bis-condensations of diamines 6 with 1,10-phenanthroline-2,9-dicarbaldehyde (5), leading to new macrocyclic 1,10-phenanthroline-diimine complexes 7 (Schiff bases, isolable as their Pb2⊕ complexes), which were then reduced with NaBH4 to yield the macrocyclic diamines 8, and ii) a high dilution cyclization reaction between the macrocyclic diamines 8 and diacyl dichlorides 9. - Syntheses, complexing abilities towards Cu⊕, and relative basicities of 4 and related compounds in ethanol are reported.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 7 (1986), S. 575-583 
    ISSN: 0173-2803
    Keywords: Chemistry ; 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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...