Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 73, Issue 1
Displaying 1-2 of 2 articles from this issue
  • Yoshiaki ARATA, Yue-Chang ZHANG
    1997 Volume 73 Issue 1 Pages 1-6
    Published: 1997
    Released on J-STAGE: October 17, 2006
    Authors have clearly proven for the first time that deuterium nuclear reaction was continuously generated inside a highly deuterated solid by showing both of the excess energy and corresponding amount of helium as the reaction product generated simultaneously. Whenever there is a nuclear fusion reaction inside a metal, helium generated is unable to escape to the surroundings and is trapped in a frozen state inside that metal. The concentration of the helium within the metal will rise with increasing rate of reactions. Pd-black is under such state as the sample used and sealed within the“closed QMS”developed by the authors (closed vessel including the Getter pump and the QMS). It is completely separated from the surroundings and the internal gases are removed to create super-vacuum. The reaction product released by the“Sample-Heating”process (room temp._??_ 1500[°C]) is thus the only matter which occupies the interior of the closed vessel and its detection by the QMS is assured. When the“closed QMS”works under the above mentioned-state, it was clarified that the“ash”or the reaction product of this fusion reaction within a solid is 42He and 32He and their ratio is 42He/32He≈4. It can be concluded from the result that the main reaction product is 42He and it is created directly as an inherent feature of the solid-state nuclear fusion. Authors think that the reaction process responsible for the creation of 32He may be a different one from that creates 42He. One of which is the Rutherford reaction process and the other occurs based on the specific properties of solid, similar to the case of 42He. The existence of 31T will be required that the process is responsible for the generation of 32He as the Rutherford reaction. The proof for the existence of 31T within the“closed QMS”, however, was not obtained in this experiments.
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  • Shuichi KOJIMA, Yukino KURIKI, Takao YOSHIDA, Kazumori YAZAKI, Kin-ich ...
    1997 Volume 73 Issue 1 Pages 7-11
    Published: 1997
    Released on J-STAGE: October 17, 2006
    The α3-peptide, which comprises three repeats of the seven-residue sequence Leu-Glu-Thr-Leu-Ala-Lys-Ala, was designed to form an amphipathic α-helix with a hydrophobic surface by Leu residues and a hydrophilic surface by Glu and Lys residues, thus yielding a coiled coil or a helical bundle structure through their association. The α3-peptide was produced by gene engineering using Escherichia coli. Association to a tetramer had been demonstrated by sedimentation equilibrium analysis in a previous study. In addition to tetramerization, electron microscopic observation revealed that the α3-peptide formed“fibrils”5 to 10nm in width in 10mM potassium phosphate/0.1M KCl (pH 6.0). By increasing the salt concentration, the α3-peptide formed much larger“fibers”assembled from many“filaments”running along the long axis, each of which was thinner and longer than those observed at lower salt concentration. Hydrophobic interaction is considered to be a main force responsible for forming the fibrous structure. However, the electrostatic features of the α3-peptide seem to affect fibril assembly, since the shape and size of the fibrous structure were altered by the ionic strength of the solution. To our knowledge, this is the first report to describe formation of a fibrous structure by a de novo designed α-helix-forming peptide, and thus the α3-peptide with its simple sequence is considered to be a potential model peptide for investigating the molecular mechanisms of fibril formation by peptides or proteins.
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