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
Filter
  • 1975-1979  (3)
  • 1976  (3)
  • Chemistry  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 10 (1976), S. 805-828 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The vital first phase of the overall materials study to protract the life of the total joint replacements is the identification of the fracture toughness and fatigue properties of bone cements. Information gained from fatigue testing, performed in a manner which simulates in vivo conditions, and fracture toughness, which is a measure of the propensity of a crack to propagate, is the first step towards the prediction of the life of the total joint replacement. This study is concerned with the fracture toughness of Zimmer and Simplex-P cold-curing bone cements.Following cement fabrication conditions which closely approximate clinical procedures, fracture toughness testing was conducted on cement specimens which were immersed in bovine serum at 37°C in order to simulate in vivo conditions. In addition, a similar study was completed on specimens, tested in air at ambient temperature for purposes of comparison. Results of this procedure, when analyzed by a Student's t-test at the 95% confidence level with eight degrees of freedom, indicate that both Zimmer and Simplex-P exhibit a higher fracture toughness in the simulated physiological environment.In order to determine whether the addition of barium sulfate to these cements compromises the fracture toughness, the above described testing rationale was repeated, indicating the existence of a complicated relationship between the different testing environments and barium sulfate. The importance of these results lies in the fact that an increased fracture toughness indicates that a cement will inherently exhibit a greater degree of resistance to the propagation of cracks, which could contribute to the ultimate failure of the total joint replacement.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly[sulfadiazinacrylamid] (5) mit 14C-Hauptkettenmarkierung wurde synthetisiert und sein Molekulargewicht viskosimetrisch durch Vergleich mit inaktiven Proben von Poly-[sulfadiazinacrylamid] mit membranosmometrisch ermittelten Molekulargewichten ähnlicher Größe bestimmt.In seinem systemischen Verhalten bei Mäusen zeigte die Verbindung einen polymerspezifisch protahierten Verlauf. Die Ausscheidungsraten des Polymeren waren vernachlässigbar gering, seine Toxizität erheblich. Es wurde im Untersuchungszeitraum in der Leber akkumuliert, aber eine Tumoraffinität zum PC6 Plasmazelltumor bei Mäusen war nicht feststellbar.
    Notes: Poly[sulfadiazineacrylamide] (5), labeled with 14C in the main chain, was synthesized and its molecular weight viscosimetrically determined by comparison with unlabeled samples of poly[sulfadiazineacrylamide] with similar molecular weights which were determined by membrane osmometry.The material showed a polymer-specific prolongation of its systemic behaviour in mice. Rates of excretion of the polymer were negligibly low, whereas the toxicity was considerable. It was concentrated in the liver during the course of the experiment, but no affinity toward the PC6 plasmacytoma in mice could be detected.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 8 (1976), S. 489-499 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Finite perturbation calculations using CNDO/2 wave functions are presented for the determination of 31P—13C and 31P—1H couplings. The calculations were carried out on 46 molecules and a comparison with experimental values is given. The groups of compounds considered were phosphonium cations, phosphine oxides, alkylidenephosphoranes, phosphine sulfides, phosphoranes and phosphines. With the exception of phosphines, the finite perturbation approach reproduces the experimental couplings with fair accuracy. It is found that there is a good correlation with the calculated 1J(P, C) and the phosphorus 3s-carbon 2s bond orders for tetra- and pentavalent phosphorus compounds. This lends support to the growing body of evidence for the direct relationship of the magnitude of 1J(P, C) and percent s character in the hybrid orbital on the carbon comprising the P—C bond. The finite perturbation technique was also used to explore the effects of geometrical changes on P—C and P—H couplings. Finally, the effect of deleting d orbitals on phosphorus is discussed briefly.
    Additional Material: 5 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...