Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 76, Issue 3
Displaying 1-3 of 3 articles from this issue
  • Shinzo KOHJIYA, Yuko IKEDA
    2000 Volume 76 Issue 3 Pages 29-34
    Published: 2000
    Released on J-STAGE: October 17, 2006
    JOURNAL FREE ACCESS
    New method to produce in situ silica in natural rubber (NR) matrix was developed for a NR/silica composite material, and the good reinforcement effect of the silica was observed on the NR vulcanizate. The silica was generated by the sol-gel reaction of tetraethoxysilane before crosslinking, which gave a homogeneous dispersion of in situ-generated silica particles in the NR matrix. This method is expected to be an industrially practical technique. It is estimated that the concentration of silanol groups on the silica surface were smaller than those on the conventional silica surface. Therefore, the silica-silica interaction of in situ silica seems to be weaker than that of silica-rubber to result in better dispersion compared with the conventional silica. The results suggest that NR which is a renewable resource and in situ silica omposite has much potential as a“green”material and a useful system for studying the reinforcement mechanism of inorganic filler onto NR.
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  • Hiroshi TOKI, Kenzo SUGIMOTO
    2000 Volume 76 Issue 3 Pages 35-40
    Published: 2000
    Released on J-STAGE: October 17, 2006
    JOURNAL FREE ACCESS
    We propose a coherent fusion mechanism of deuterons in the paradium (Pd) double structure cathode as the source of extra heat generation in the heavy water electrolysis. In the course of searching a possible mechanism for deuteron fusion into alpha particle without emitting energetic photons nor protons/ neutrons, we arrive at the coherent deuteron process, where the deuterons participate coherently to the fusion in the Bose-Einstein condensed state with the help of alphas of large binding energy. The extra fusion energy is immediately carried away by a macroscopic amount of deuterons. The fusion rate comes out to be very high and we conjecture that the experimental fusion rate is governed by the rate of deuteron ions to be trapped by Pd powders.
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  • Shingo NAGASAWA, Takashi SHIMOKAWA, Mitsuko MASUTANI, Tadashige NOZAKI ...
    2000 Volume 76 Issue 3 Pages 41-44
    Published: 2000
    Released on J-STAGE: October 17, 2006
    JOURNAL FREE ACCESS
    Most of eukaryotes, except for Saccharomyces cerevisiae, possess poly(ADP-ribose) polymerase (PARP, EC 2.4.2.30) activity. Poly(ADP-ribose) is described to be mainly degraded by poly(ADP- ribose) glycohydrolase (PARG) and also by phosphodiesterase I (PDEase, EC 3.1.4.1). To understand the function and metabolism of poly(ADP-ribose), the distribution of poly(ADP-ribose) degradation activity in various kinds of species was investigated. Poly(ADP-ribose) degradation activity was detected in extracts from various kinds of eukaryotes including Rattus norvegicus, Sarcophaga peregrina, Caenorhabditis elegans, Dictyostelium discoideurn, Tetrahymena thermophila, Tetrahymena pyrifornis, and Neurospora crassa. However, poly(ADP-ribose) degradation activity was not observed in Schizosaccharomyces pombe, and prokaryotes, namely Escherichia coli and Halobacterium volcanii. The main degradation products of [32P]poly(ADP-ribose), which were detected by the radioactivity, were ADP-ribose, phosphoribosyl-AMP and 5'-AMP at different ratios in each species. This suggests that PARG and PDEases are involved in the degradation of poly(ADP-ribose) at the initial step. Since poly(ADP-ribose) degradation due to PARG activity and PDEase activity, and poly(ADP-ribose) formation due to PARP activity were not detectable in Schizosaccharomyces pombe, Escherichia coli and Halobacterium volcanii, the presence of PARG as well as PDEase well correlates with that of PARP in various kinds of species.
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