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Volume 71, Issue 8
Displaying 1-6 of 6 articles from this issue
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Tamaki NAKANO, Yoshifumi SHIKISAI, Yoshio OKAMOTO1995 Volume 71 Issue 8 Pages 251-255
Published: 1995
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSFree radical polymerization of 1-phenyldibenzosuberyl methacrylate was carried out in toluene at 40 or 50°C under chiral reaction conditions based on the use of (-)-dimenthyl peroxydicarbonate as an initiator, (-)- and (+)-menthol as a reaction solvent (additive), and (+)- and (-)-neomenthanethiol as a chain transfer agent. The obtained polymers had a highly isotactic and helical structure; there was an excess of right- or left-handed helicity by the influence of the above chiral materials and consequently, the polymers were optically active. The mechanism of chiral induction for the polymerization using the chiral initiator involved helix-sense-selective primary radical termination, i.e., the reaction between a polymer radical and an initiator radical. In the polymerization using menthol and neomenthanethiol, hydrogen transfer from these chiral compounds to the growing radical appeared to take place in a helix-sense-selective manner.View full abstractDownload PDF (585K) -
Yasuhide MINONISHI1995 Volume 71 Issue 8 Pages 256-259
Published: 1995
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSTransmission electron microscope study has been performed on the pyramidal slip dislocations activated in single crystals of Ti3Al compressed along the c-axis at 600-700°C. The pyramidal slip dislocations are observed to bow out in a form of hairpin. These dislocations are shown to be superpartial dislocations with Burgers vector 1/6<1126>. It is also shown that pairs of unlike superpartials coupled by antiphase boundaries are formed in the same temperature range.View full abstractDownload PDF (1954K) -
Yasuhide MINONISHI1995 Volume 71 Issue 8 Pages 260-264
Published: 1995
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSThe <1126>{1121} pyramidal slip in Ti3Al shows the so-called yield stress anomaly. Near the peak-stress temperature, specimens collapse by shearing on {1121} slip plane almost immediately after yielding. Transmission electron microscope study revealed that pairs of unlike 1/6<1126>{1121} superpartial dislocations coupled by antiphase boundaries were generated in the same temperature range. These superpartials are of edge in character and are shown further to climb-dissociate on the basal plane into partials of smaller Burgers vector bounding a complex stacking fault: the dissociation is described by an equation 1/6<1126>→1/6<1013>+1/6<0113>. Fracture of single crystals at high temperatures is associated with locking of 1/6<1126> superpartials by climb dissociation.View full abstractDownload PDF (1719K) -
Abdul-Hameed KHADHAIR, Fouad MOMANI, Chuji HIRUKI1995 Volume 71 Issue 8 Pages 265-268
Published: 1995
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSThis paper describes a simple, rapid and economical method to preserve healthy plant tissues or those infected with phytoplasma for molecular diagnosis and analysis. After thermal treatments, clover proliferation (CP) phytoplasma DNA in periwinkle leaf samples, which was exposed to the microwave heat up to 480sec, remained intact but not after 600sec. The extracted DNA of the CP-infected tissues was amplified with phytoplasma universal primers showing a typical single band of 558bp in the microwave treated samples except the 600sec treatment, or healthy controls. Restriction digestions of PCR products of the heat treated samples with Alu I enzyme showed patterns similar to that with the digested PCR product of a fresh CP-infected sample on 5% polyacrylamide gel-electrophoresis, indicating its stability after the microwave heat treatment. The identity of CP phytoplasma in each heat-treated sample was confirmed by its amplification with specific primers forming a prominent band of 196bp which matched the size of the primer pair that was specific to CP phytoplasma.View full abstractDownload PDF (1084K) -
Hiroshi UEMURA, Masashi SUZUKI1995 Volume 71 Issue 8 Pages 269-273
Published: 1995
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSSome structural features of the yeast Gcr1 protein (Gcr1p) are analysed. The protein has three hydrophobic domains separated by hydrophilic residues (referred to as N, L, C), which correspond well with three regions of different functions. The N domain (aal-aa350) corresponds to the region (aa1-aa391) which is important for Gcr1p-Gcr1p and Gcr1p-Gcr2p interactions, while the C domain (aa570-aa785) corresponds to the region (aa631-aa785) which is important for DNA-binding. The function of the L domain (aa360-aa550) remains unknown but it contains many Ser(Thr)-Pro sequences which are potential phosphorylation sites and thus might be used for regulation of the protein function. The sequence, aa631-aa685, resembles those of multi-helical DNA-binding domains found in some transcription factors. In comparison with the DNA-binding mode of known multi-helical DNA-binding domains, DNA base-amino acid side-chain contacts at the Gcr1 site are discussed.View full abstractDownload PDF (570K) -
Increase by Nitroglycerin and Decrease by NO Synthase InhibitorsSachin A. GUPTE, Takao OKADA, Rikuo OCHI1995 Volume 71 Issue 8 Pages 274-278
Published: 1995
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSIsolated rat hearts were perfused with a O2--generating system consisting of purine plus xanthine oxidase for 15 or 20min. After the O2- pretreatment, washout (performed with normal Krebs solution) produced significant elevation of coronary perfusion pressure (CPP). After 20min O2- pretreatment, administration of 4μM nitroglycerin or 1μM sodium nitroprusside, which are nitric oxide (NO) donors, enhanced the elevation of CPP. Conversely, 100μM nitro-L-arginine or 10μM NG-monomethyl-L-arginine, which are NO synthase inhibitors, immediately induced vasorelaxation in O2--pretreated hearts. Thus, it was suggested that NO, a physiological vasodilator, paradoxically augments constriction of the coronary arteries, in O2--pretreated rat heart.View full abstractDownload PDF (699K)
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