Secondary structural analysis of the mRNA regions encoding the hemagglutinin cleavage site basic amino acids of the avian influenza virus H5N1 subtype samples

Here we report the codon bias and the mRNA secondary structural features of the hemagglutinin (HA) cleavage site basic amino acid regions of avian influenza virus H5N1 subtypes. We have developed a dynamic extended folding strategy to predict RNA secondar

NR2B-containing N-methyl-D-aspartate subtype glutamate receptors regulate the acute stress effect on hippocampal long-term potentiation/long-term depression in vivo

Behavioral stress facilitates long-term depression but impairs long-term potentiation in the hippocampus. Recent evidence in vitro demonstrates that the NIR2B-containing N-methyl-D-aspartate subtype glutamate receptor antagonist Ro25-6981 prevents the beh

Detection of avian influenza virus subtype H5 using a biosensor based on imaging ellipsometry

A novel method is reported for the detection of avian influenza virus subtype H5 using a biosensor based on high spatial resolution imaging ellipsometry (IE). Monoclonal antibodies specific to H5 hemagglutinin protein were immobilized on silicon wafers and used to capture virus particles. Resultant changes on the surface of the wafers were visualized directly in gray-scale on an imaging ellipsometry image. This preliminary study has shown that the assay is rapid and specific for the identification of avian influenza virus subtype H5. Compared with lateral-flow immunoassays, this biosensor not only has better sensitivity, but can also simultaneously perform multiplexed tests. These results suggest that this biosensor might be a valuable diagnostic toot for avian influenza virus detection. (c) 2009 Elsevier B.V. All rights reserved.

海带根中α-glucosidase 和PTP-1B 靶向生物活性物质的分离纯化及其抗糖尿病作用研究

海带根是一种治疗糖尿病的民间中药，在沿海地区有很长的民间用药历史。食用海带根能够有效降低糖尿病患者的血糖，起到治疗作用。本文目的在于发现海带根中抗糖尿病的天然活性物质并分析它们在糖尿病治疗中的靶点；进一步开发一种低价且无毒副作用的化学类新药或中药新药。 α-glucosidase和 PTP-1B是II型糖尿病的两个重要靶点，海带根提取物能同时作用于这两个靶点。通过抑制这两种酶，降低血糖水平，85%乙醇粗提物对两种酶的IC50分别为1589ug/ml、IC50 1271ug/ml。乙酸乙酯相和石油醚相分别抑制α-glucosidase和 PTP-1B，IC50分别为380ug/ml和220ug/ml。因此以α-glucosidase和 PTP-1B的抑制活性为导向，用天然产物化学的方法对活性成分进行追踪分离，寻找单体活性物质进而鉴定其结构。由于乙酸乙酯相具有α-glucosidase抑制活性，用硅胶柱层析（石油醚：丙酮5：1、1：1），（二氯甲烷：甲醇60：1、20：1、5：1），凝胶柱层析Sephadex LH20（二氯甲烷：甲醇1：1），HPLC （80% 甲醇-水），对α-glucosidase抑制剂进行分离，得到组分IC50 为3.6ug/ml。用质谱仪和核磁共振确定结构。 生物活性测定结果表明α-glucosidase和 PTP-1B是两种不同的物质，分别位于乙酸乙酯相和石油醚相。光照实验和高温实验表明抑制α-glucosidase的活性成分对光照和温度敏感。光照48h或者50℃ 12h而且对α-glucosidase的抑制活性显著降低，TLC检测并用FeCl3显色初步表明抑制α-glucosidase的活性成分可能是多数酚类物质。动物实验显示在1450ug/kg剂量下，乙酸乙酯相能够显著降低糖尿病小鼠血糖，与阴性对照组差异极显著（P<0.01）。表明，海带根提取物在体内和体外均呈现出抗糖尿病活性，是一种潜在的抗糖尿病药物。

Ultrabroad infrared luminescences from Bi-doped alkaline earth metal germanate glasses

We report on ultrabroad infrared (IR) luminescences covering the 1000-1700-nm wavelength region, from Bi-doped 75GeO(2) 20RO-5Al(2)O(3) 1B(2)O(3) (R = Sr, Ca, and Mg) glasses. The full width at half-maximum of the IR luminescences excited at 980 nm increases (315 -> 440 -> 510 nm) with the change of alkaline earth metal (Mg2+ -> Ca2+ -> Sr2+). The fluorescence lifetime of the glass samples is 1725, 157, and 264 mu s when R is Sr, Ca, and Mg, respectively. These materials may be promising candidates for broad-band fiber amplifiers and tunable laser resources.