Polymeric micelles with glycolipid-like structure and multiple hydrophobic domains for mediating molecular target delivery of paclitaxel

Herein, polymeric micelles with glycolipid-like structure and about 40 nm diameter are prepared by self-aggregation from stearate-grafted chitosan oligosaccharides in aqueous medium. The micelles, with high degree of substitution (DS), present specific spatial structure with multiple hydrophobic "minor cores", and thus obtain excellent internalization into cancer cells and accumulation in cytoplasm. Furthermore, the micelles showed pH-sensitive properties, thus favoring intracellular delivery of encapsulated drug via endocytosis. The cell cytotoxicity of paclitaxel encapsulated in micelles was improved sharply and contributed to the increased intracellular delivery of the drug. The present micelles are a promising carrier candidate for targeting therapy of antitumor drugs with a cytoplasmic molecule target.     

鸡腿菇特有病害鸡爪菌生物学研究——危害与形态学研究

鸡爪菌是危害鸡腿菇的一种特有病害,对其危害和形态特征研究结果表明:该菌可使鸡腿菇菌料内菌丝断裂、发黄、消解,菌料松散,子实体畸形、萎缩直至腐烂、死亡。该菌由菌丝体和子座2部分所组成。菌丝无色、有结节、隔膜多、节间长短不一。子座发达,可反复形成分枝;未成熟子座呈灰绿色,表面菌丝顶端专化形成分生孢子梗和圆形分生孢子;成熟子座呈土灰色至黑褐色,表面形成大量梨形子囊壳。子囊圆柱状,内生8个椭圆形子囊孢子。     

The effect of thymectomy on the mixed leukocyte reaction and phytohemagglutinin responsiveness in the clawed toadXenopus laevis

In the clawed toadXenopus laevis, thymectomy at 7 days of age abrogates the phytohemagglutinin response of leukocytes and the mixed leukocyte reaction.A project grant from the Medical Research Council to Dr. J.D. Horton is gratefully acknowledged.     

Characterizing the spatial distribution of giant pandas (Ailuropoda melanoleuca) in fragmented forest landscapes

Aim To examine the effects of forest fragmentation on the distribution of the entire wild giant panda (Ailuropoda melanoleuca) population, and to propose a modelling approach for monitoring the spatial distribution and habitat of pandas at the landscape scale using Moderate Resolution Imaging Spectro‐radiometer (MODIS) enhanced vegetation index (EVI) time‐series data. Location Five mountain ranges in south‐western China (Qinling, Minshan, Qionglai, Xiangling and Liangshan). Methods Giant panda pseudo‐absence data were generated from data on panda occurrences obtained from the third national giant panda survey. To quantify the fragmentation of forests, 26 fragmentation metrics were derived from 16‐day composite MODIS 250‐m EVI multi‐temporal data and eight of these metrics were selected following factor analysis. The differences between panda presence and panda absence were examined by applying significance testing. A forward stepwise logistic regression was then applied to explore the relationship between panda distribution and forest fragmentation. Results Forest patch size, edge density and patch aggregation were found to have significant roles in determining the distribution of pandas. Patches of dense forest occupied by giant pandas were significantly larger, closer together and more contiguous than patches where giant pandas were not recorded. Forest fragmentation is least in the Qinling Mountains, while the Xiangling and Liangshan regions have most fragmentation. Using the selected landscape metrics, the logistic regression model predicted the distribution of giant pandas with an overall accuracy of 72.5% (κ = 0.45). However, when a knowledge‐based control for elevation and slope was applied to the regression, the overall accuracy of the model improved to 77.6% (κ = 0.55). Main conclusions Giant pandas appear sensitive to patch size and isolation effects associated with fragmentation of dense forest, implying that the design of effective conservation areas for wild giant pandas must include large and dense forest patches that are adjacent to other similar patches. The approach developed here is applicable for analysing the spatial distribution of the giant panda from multi‐temporal MODIS 250‐m EVI data and landscape metrics at the landscape scale.