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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 21 (1984), S. 84-89 
    ISSN: 1432-1432
    Keywords: Parity violation ; β-Decay ; Asymmetric radiolysis ; Optical activity ; Vester-Ulbricht hypothesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A brief review is presented of the Vester-Ulbricht β-decay Bremsstrahlen hypothesis for the origin of optical activity, and of subsequent experiments designed to test it. Certain of our experiments along these lines, begun in 1974 and involving the irradiation of racemic and optically active amino acids in a 61.7 KCi90Sr−90Y Bremsstrahlen source, have now been completed and are described. After 10.89 years of irradiation with a total Bremsstrahlen dose of 2.5×109 rads, crystallinedl-leucine, norleucine, and norvaline suffered 47.2, 33.6, and 27.4% radiolysis, respectively, but showed no evidence whatsoever of asymmetric degradation.d- andl-Leucine underwent about 48% radiolysis and showed 2.4–2.9% radioracemization. Other samples in solution were too severely degraded to analyze. Probable intrinsic reasons for the failure of the Vester-Ulbricht mechanism to afford asymmetric radiolysis in the present and related experiments involving β-decay Bremsstrahlen are enumerated.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 15 (1980), S. 21-28 
    ISSN: 1432-1432
    Keywords: β-radiolysis ; Asymmetric radiolysis ; Vester-Ulbricht Hypothesis ; Origin of optical activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have extended earlier experiments on the radiolysis of DL-tryptophan using32Pβ-radiation to longer reaction times, observing complete destruction of the tryptophan by secondary, non-radiolytic processes. We have also undertaken the irradiation of DL-leucine with32Pβ's at -196°, achieving radiolyses to the extents of ca. 20–30%, but observing no concomittant asymmetric bias. The implications of these observations are discussed with regard to the Vester-Ulbricht mechanism for the origin of optical activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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