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549 results on '"Yamauchi R"'

110. Differentiation of Three Varieties of Rhizoctonia circinata ; var.circinata , var.oryzae and var.zeae on the Basis of Cellular Fatty Acid Composition.

Author

PRIYATMOJO, A, YAMAUCHI, R, CARLING, D. E, KAGEYAMA, K, and HYAKUMACHI, M

Subjects
*RHIZOCTONIA, *FATTY acids
Abstract

Cellular fatty acid analysis was employed to differentiate three varieties of Rhizoctonia circinata; var. circinata, var. oryzae and var. zeae. Eight fatty acids including myristic (14:0), pentadecanoic (15:0), palmitic (16:0), palmitoleic (16:1 cis9), stearic (18:0), oleic (18:1 cis9), linoleic (18: 2 cis9,12) and linolenic (18: 3 cis9,12) acids were present in isolates of all three varieties of R. circinata. Heptadecanoic acid (17:0) was detected in isolates of R. circinata var. zeae but not in isolates of R. circinata var. circinata or R. circinata var. oryzae. Palmitic, oleic and linoleic acids were the major fatty acids found, comprising 94-98% of the whole-cell fatty acid content. The remaining fatty acids were present in small amounts. Based on the composition (%) of fatty acids, isolates of R. circinata var. circinata, R. circinata var. oryzae and R. circinata var. zeae were clearly differentiated into three groups as shown by principal component and cluster analyses. This finding agrees well with the grouping of R. circinata into three varieties based on differences in colony morphology of the vegetative state. In principal component and cluster analysis, isolates of R. circinata var. circinata from Japan and Alaska were indistinguishable. [ABSTRACT FROM AUTHOR]

Published
2002
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112. Effects of omeprazole and pirenzepine on enterochromaffin-like cells and parietal cells in rat stomach.

Author

Tari, Akira, Kuruhara, Yoshitada, Yonei, Yoshikazu, Yamauchi, Ryo, Okahara, Shiro, Sumii, Koji, Kajiyama, Goro, Tari, A, Kuruhara, Y, Yonei, Y, Yamauchi, R, Okahara, S, Sumii, K, and Kajiyama, G

Subjects
OMEPRAZOLE, PIRENZEPINE, HISTAMINE, ADENOSINE triphosphatase, CHROMAFFIN cells, BIOSYNTHESIS
Abstract

Purpose: The purpose of this study was to investigate the mechanism of the regulation of histamine synthesis in enterochromaffin-like cells, chemically and structurally, by treatment with omeprazole and pirenzepine.Methods: The ultrastructures of enterochromaffin-like cells and parietal cells were examined in rats treated with oral omeprazole (20 mg/kg) or intraperitoneal pirenzepine (1 mg/kg) administration. Serum gastrin concentrations, mRNA levels of H+-K+-ATPase and histidine decarboxylase, and the fundic concentrations of somatostatin and histamine were determined.Results: Pirenzepine treatment suppressed omeprazole-induced increases in serum gastrin levels and mRNA levels of H+-K+-ATPase and histidine decarboxylase. Pirenzepine also decreased omeprazole-induced increases of histamine concentration in fundic mucosa. Pirenzepine elevated somatostatin mRNA level, previously decreased by omeprazole treatment, in fundic mucosa. In the cytoplasm of enterochromaffin-like cells, omeprazole markedly reduced the numbers of vesicles and granules, but significantly increased their diameters, whereas pirenzepine treatment changed neither of these features. The densities and diameters of both vesicles and granules produced by treatment with omeprazole and pirenzepine were between those produced by treatment with omeprazole alone and pirenzepine alone.Conclusions: Omeprazole-induced hypergastrinemia and pirenzepine-induced somatostatin synthesis play important roles not only in histamine synthesis but also in ultrastructural changes in enterochromaffin-like cells. [ABSTRACT FROM AUTHOR]

Published
2001
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118. Excited-State Dynamics of 1-Piperidino- or 1-Pyrrolidino-anthraquinone for Formation of N−Ylide and Reduced Compounds

Author

Nakayama, T., Yamauchi, R., Shin, H., and Hamanoue, K.

Abstract

By means of subpicosecond laser photolysis of the title compound at room temperature, time-dependent shift of an absorption band has been observed at short delay times which is ascribed to solvent reorganization around the lowest excited singlet state of the solute molecule with an intramolecular charge-transfer character. In comparison with the results obtained by nanosecond laser photolysis and steady-state photolysis at 77 K, it is concluded that the lowest excited singlet state undergoes rapid intramolecular proton transfer forming an N-ylide compound. For formation of the N-ylide compound from the lowest excited singlet state of 1-piperidino-anthraquinone, it is considered that there exists an intermediate which can be ascribed to transfer of the equatorial proton to the carbonyl oxygen anion. At room temperature, no formation of N-ylide compound as a stable compound can be observed due to its rapid reversion to 1-piperidino- or 1-pyrrolidino-anthraquinone. Steady-state photolysis in ethanol at room temperature gives rise to formation of a reduced compound. Yield of the reduced compound is obtained by 405 or ≥510 nm photolysis, however, is negligibly small compared with that obtained by 313 or 366 nm photolysis. Hence, it is proposed that intersystem crossing from a higher excited singlet state (probably the second excited singlet state) to a higher excited triplet state (probably the third excited triplet state) followed by internal conversion to the lowest excited triplet (T1) state plays an important role for the photoreduction, i.e., the reduced compound may be formed from the T1 state, although the possibility of additional photoreduction originating from the second excited triplet state cannot be ruled out.

Published
2000

136. Independent and Interdependent Atomistic Structural Features of Pd Clusters Supported on the MgO(001) Surface

Author

Yamauchi, R., Kubo, M., Miyamoto, A., Vetrivel, R., and Broclawik, E.

Abstract

Pd particles supported on the MgO(001) surface were simulated by the molecular dynamics (MD) method. The surface and inner structures of the particles as well as the interaction sites of the Pd atoms were investigated by using computer graphics (CG) techniques. The numerical features of the surface atomic rows, the in-plane symmetric configurations, the height deviation of the layer, and the lattice length defined by the distance between near neighboring rows were estimated. The dependency and the interdependence of these atomistic characteristics were evaluated. The findings on the lattice spaces were compared with the experimental and other theoretical calculation results.

Published
1998

137. Concentration Dependence of the Neel Temperature of ...-phase Mn...Ru... Alloys.

Author

Sasao, K. and Yamauchi, R.

Subjects
*MAGNETIC susceptibility, THERMAL properties of alloys
Abstract

Presents a study which investigated the concentration dependence of the Neel temperature of gamma-Mn...Ru... alloy systems by magnetic susceptibility and electrical resistivity measurements. Application of manganese-transition metal alloys in spin-valve layers of magnetoresistive heads; Experimental procedure; Results and discussion; Conclusion.

Published
1999
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