A NEW SPECIES OF GENUS HABROPHLEBIODES ULMER (EPHEMEROPTERA: LEPTOPHLEBIIDAE)

Abstract  The present paper deals with a new species Habrophlebiodes zijinensis sp. nov. collected in Nanjing, Jiangsu Povince, China.     

帕里红景天的化学成分研究

从帕里红景天根茎的石油醚和乙醇提取部分共分得１４种结晶性化合物,经光谱分析和化学反应,分别鉴定为二十二醇、二十六酸、十九醇、β－谷甾醇、二十九醇、红景天甙、麦芽糖、棉皮素－８－葡萄糖甙、胡萝卜甙、酪醇、咖啡酸、没食子酸、形花内酯和新化合物帕里甙。     

Uptake by central nervous tissues as a mechanism for the regulation of extracellular adenosine concentrations

The various facets of the uptake of adenosine by central nervous tissues are described. The uptake process includes the transport of nucleoside across neuronal and glial plasma membranes and its metabolism within the cell. Much of the transported adenosine is phosphorylated into adenosine nucleotides. Inhibitors of adenosine uptake increase extracellular levels of adenosine and can thus potentiate its pharmacological actions. This may be an important component in the actions of various groups of psychoactive drugs.     

The shape of myosin subfragment-1. A equivalent oblate ellipsoid model based on hydrodynamic properties

The molecular weights of the two heads of myosin subfragment-1, S-1(A1) and S-1(A2), based on sedimentation equilibrium are 120 000 and 110 000. Hydrodynamically, the two heads are indistinguishable, with intrinsic viscosity, [eta], of 0.064-0.065 dL/g and sedimentation coefficient, s(0)20,w, of 5.8 S.Together with the rotational correlation time taken from the literature (235 ns), all three hydrodynamic properties can be better fitted with an equivalent oblate ellipsoid of revolution than a prolate model. The width of the equatorial axis of the ellipsoid is about 135 A (the axial ratio is about 6). Probably, the S-1(A1) and S-1(A2) molecules have a half-doughnutlike or a flattened pearlike shape rather than an elongated one.     

Hyphal anastomosis inPyricularia oryzae cav.

Summary Hyphal anastomosis inPyricularia oryzae occurs naturally in the lower epidermal cells and in the vascular bundles of young lesions on rice. In those cells the invading blast fungus are active. Two hyphal cells lying side by side start an anastomosis by forming two, one from each, very short penetration pegs which are opposite to each other. The cell wall of the pegs and the wall in the vicinity of them are then gradually eliminated and thus form a fusion aperture of 0.2–0.6 m in diameter that is big enough for the migration or exchange of nucleus and cytoplasm between two hyphal cells. The explanation of genetical variation inP. oryzae may be sought on the basis of the ultrastructural evidence of hyphal anastomoses presented in this paper.