In-plane Anisotropy on Resistivity and Thermopower in The Misfit Layered Oxide Bi2-xPbxSr2Co2Oy

We investigated the in-plane anisotropy on the resistivity and thermopower of Bi2-xPbxSr2Co2Oy single crystals, which have a misfit structure between the hexagonal CoO2 layer and the rock salt Bi2Sr2O4 layer. The resistivity and thermopower show significantly large anisotropy, which exceeds two at maximum. This anisotropy would come from the anisotropic pseudogap formation enhanced by the misfit structure. The thermopower changes with Pb doping to take a maximum at x=0.4. The misfit structure improves the thermoelectric properties through chemical pressure. The power factor is as large as 9 muW/cmK2 at 100 K for x=0.6, which is the highest value for thermoelectric oxides at 100 K.Comment: 4 pages, 3 figures, submitted to Jpn. J. Appl. Phy

キュウセイ ダイドウミャク カイリ ヤマガタケン ニオケル セイレキ 2000ネン ノ ケイケン

Objective: Prefectural clinico-epidemiological survey of acute aortic dissection has not been widely carried out.　Methods: We collected data of all patients with acute aortic dissection in Yamagata Prefecture, and retrospectively reviewed their primary treatments throughout 2000.　Results: There were 71 patients with an acute aortic dissection and an incidence calculated from this number was 5.7 per 100,000 people per year. Patient\u27s age was 23-92(69+14) years. Male and female ratio was 44/27. Stanford type A aortic dissection was 35 patients and B 35. Complications of acute aortic dissection were shock in 12, cardiac tamponade in 16, rupture in 5, abdominal ischemia in 8, limb ischemia in 6 and brain infarction in 2. Two patients were in cardiac pulmonary arrest on arrival. Overall inhospital mortality was 13%, except for 2 patients. In Stanford A type aortic dissection, surgery was done in 21 and mortality was 9.5%; among those not receiving surgery mortality was 29%. In Stanford type B aortic dissection, death occurred in 2 patients out of 5 after emergency operation, and no putients out of 30 who were medically treated.　Conclusion: Incidence of acute aortic dissection calculated from this survey was 5.7 per 100,000 people per year in Yamagata Prefecture. Seven of 71(10%) died in the acute phase. Operative mortality for Stanford type A aortic dissection was 9.5%, while that of medical management was 29%. Operative mortality for Stanford type B aortic dissection was high, but medical treatment had no mortality. More aggressive treatment would improve initial results of acute aortic dissection.　Key words : acute aortic dissection, incidence, mortality, Yamagat

Pseudogap Phase Boundary in Overdoped Bi_2Sr_2CaCu_2O_8 Studied by Measuring Out-of-plane Resistivity under the Magnetic Fields

The characteristic pseudogap temperature T* in Bi2Sr2CaCu2O8 system has been systematically evaluated as a function of doping, especially focusing on its overdoped region, by measuring the out-of-plane resistivity under the magnetic fields. Overdoped samples have been prepared by annealing TSFZ-grown Bi2Sr2CaCu2O8 single crystals under the high oxygen pressures (990 kgf/cm2). At a zero field, the out-of-plane resistivity showed a metallic behavior down to Tc (= 62 K), while under the magnetic fields of over 3 T,it showed typical upturn behavior from around 65 K upon decreasing temperature. This result suggests that the pseudogap and superconductivity are different phenomena.Comment: 2 pages, 2 figures. Final version accepted for the Proceedings of the M2S-IX Conference (Tokyo, September 2009

S-Nitrosation of Cellular Proteins by NO Donors in Rat Embryonic Fibroblast 3Y1 Cells: Factors Affecting S-Nitrosation

The mechanism of protein S-nitrosation in cells is not fully understood. Using rat 3Y1 cells, we addressed this issue. Among S-nitrosothiols and NO donors tested, only S-nitrosocysteine (CysNO) induced S-nitrosation when exposed in Hanks' balanced salt solution (HBSS) and not in serum-containing general culture medium. In HBSS, NO release from CysNO was almost completely abolished by sequestering metal ions with a metal chelator without affecting cellular S-nitrosation. In contrast, L-leucine, a substrate of L-type amino acid transporters (LATs), significantly inhibited S-nitrosation. The absence of S-nitrosation with CysNO in general culture medium resulted not only from a competition with amino acids in the medium for LATs but also from transnitrosation of cysteine residues in serum albumin. Collectively, these results suggest that in simple buffered saline, CysNO-dependent S-nitrosation occurs through a cellular incorporation-dependent mechanism, but if it occurs in general culture media, it may be through an NO-dependent mechanism