Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 77 , Issue 4
Showing 1-4 articles out of 4 articles from the selected issue
  • Sumiko HAMANAKA, Minoru SUZUKI, Akemi SUZUKI, Tamio YAMAKAWA
    2001 Volume 77 Issue 4 Pages 51-56
    Published: 2001
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Skin protects the human body from dryness and its molecular mechanism has been studied by both biological and biochemical approaches. The epidermis is the outer layer in skin and forms a water barrier. Animal experiments with diets deficient in essential fatty acids have demonstrated that lipids containing linoleic acid are essential molecules in the maintenance of the epidermal water barrier. Structural analysis revealed that linoleic acid-containing epidermal lipids include acylglucosylceramides, which are comprised of both very long chain ω-hydroxy fatty acids as the amide-linked fatty acids and linoleic acids as the esterified fatty acid linked through the ω-hydroxyl group. Human epidermis consists of two acylglucosylceramide groups, one containing sphingenine and the other containing phytosphingosine with a single double bond. We named these functional lipids“Epidermosides”. ω-Hydroxylation is the rate limiting biosynthetic step for the expression of these functional lipids and investigation of the hydroxylase active in this process is an important target for the further research.
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  • Keizo SAYANAGI, Kiyokazu NISHIMURA, Masato JOSHIMA, Shin'ichi KURAMOTO
    2001 Volume 77 Issue 4 Pages 57-62
    Published: 2001
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    A deep-tow magnetic survey was conducted in the northeastern margin of the Japan Basin during the GH96 cruise aboard the RAT Hakurei-maru in 1996, using a new deep-tow observation system with multiple sensors. Surface magnetic and seismic reflection data were also taken simultaneously. A deep-tow magnetic anomaly (amplitude: 775nT; wavelength: 8km) was detected, while no obvious anomaly was observed at the surface. In order to explain both surface and deep-tow magnetic features, we applied a two-dimensional forward modeling taking the results of ODP deep-sea drilling at Site 795 and the surface seismic reflection data in consideration. We obtained a magnetized layer with its top at the depth of acoustic basement, which well reproduced both of the observed magnetic anomalies. Comparison of the magnetic model with the seismic reflection data indicates that there is a good correlation between magnetization high and strongly reflecting basement. The correlation may be associated with the age and structure of the volcanic basement rocks. Magnetic data at different altitude levels, thus, showed that they can give better constraints on the depth of the source layer.
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  • Tamotsu HASHIMOTO, Akihiro UMEHARA, Koji ISHIZUKA, Toshiyuki KODAIRA
    2001 Volume 77 Issue 4 Pages 63-67
    Published: 2001
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Hydroxyl-terminated telechelic polyacetals were synthesized by polyaddition of 4-hydroxybutyl vinyl ether (HBVE; CH2=CH-O-CH2CH2CH2CH2-OH) in the presence of 1, 4-butanediol with p-toluenesulfonic acid monohydrate (TSAM) as a catalyst in tetrahydrofuran (THF) at 0°C. The structural analysis showed that the produced polymers had hydroxyl groups at both the chain ends. The polyacetals thus obtained were stable under neutral and basic conditions, but exhibited smooth degradation with treatment of acid to give 1, 4-butanediol in quantitative yield. The polymers were highly viscous liquid and its glass transition temperature (Tg) was -72°C.
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  • Yoshihiro FUKUSHIMA, Makoto USHIMARU
    2001 Volume 77 Issue 4 Pages 68-72
    Published: 2001
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    The current dogma describes that the amount of biological work done by ATPase is limited only by the free energy change in the hydrolysis of ATP. However, this is not a principal requirement. As the system consists of both ATP and ATPase, it is the potential energy change in the entire system before and after ATP hydrolysis that should be considered. In this paper we reconsider the conceptual framework for energy transduction by the ATPase-ATP system from the point of view of the change in internal potential energy in the entire system.
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