3H-二脱水伊地醇双甲磺酸酯在小鼠体内的吸收、分布和排泄

采用＾３Ｈ－标记药物和放射性测定法，测定了抗肿瘤药二脱水伊地醇双甲磺酸酯在小鼠体内的吸收，分布和排泄，并进行了药动学参数统计学处理，结果表明，ＤＭＤＡＩ静注时血度浓度分布快，但消除较慢，灌胃给药时吸收迅速。静注和灌胃时组织中分布均以胆汁及肝脏含量较高，静注７ｄ内药物在粪尿中排泄完全，不易蓄积。     

3,5,6—三氯水杨酸戊酯的合成及鉴定

3,5,6—三氯水杨酸戊酯是合成新型发光材料过氧草酸酯类的重要原料.3,5,6—三氯水杨酸戊酯是由3,5,6—三氯水杨酸与正戊醇用浓硫酸作催化剂酯化得到的.酯化原理及反应条件是本文研究的重点.     

基于虚拟样机的倾转旋翼/机翼系统动力学仿真

综合运用CATIA、MSC.Simdesigner、ANSYS和ADAMS建立V-22倾转旋翼机1/5缩比动力学模型,并在ADAMS平台上对其进行运动学和动力学特性仿真、分析,通过与V-22倾转旋翼机1/5缩比原型数据的对比,表明所建立的虚拟样机模型正确,结果是可信的。最后分析了倾转过程中机翼弯矩变化的时间历程,其规律能反映出倾转旋翼机机翼变化的实际情况,为以后的倾转旋翼机的设计、试验提供了参考依据。     

溶胶-凝胶法制备层状LiMn0．5Ni0．5O2锂离子电池正极材料及其电化学性能

以醋酸锂、醋酸锰和醋酸镍为原料，羟基乙二酸为螯合剂，通过溶胶-凝胶法制备层状LiMn0．5Ni0．5O2正极材料，得到的产物具有典型的α-NaFeO2层状结构，颗粒尺寸在300-400nm之间。对900℃下制得的层状LiMn05Ni0．5O2在2.5-4．3V之间进行充放电测试，电流密度为0．1mAcm^-2，其首次放电容量达到了161．2mAh g-^1。经过20次循环后，仍然保留了初始容量的88％。     

流式细胞技术对莱哈衣藻(Chlamydomonas reinhardi)配子形成过程的观察

应用流式细胞仪观察了不同暗交替周期对莱哈衣藻的配子形成过程影响,并采用核酸抑制剂和蛋白合成抑制剂处理,观察其配子配对情况。结果表明在缺氮诱导条件下,前期的光照对配子分化形成十分重要,而先黑暗后光照或连续黑暗诱导时,细胞或配子的分裂缺乏规律性。     

梨矮化中间砧PDR54、S5和S2对金花梨的矮化性能初探

通过梨砧木嫁接实验,以棠梨为基砧,嫁接‘金花梨’,对具有矮化潜力的梨中间砧PDR54、S5和S2进行矮化性能研究表明,PDR54、S5和S2对‘金花梨’所表现的矮化性能差异较大．当中间砧砧段长为10cm时,三者矮化性能均不明显,仅PDR“的致矮程度达76．7％,属于半矮化砧;但当中间砧砧段长增至20cm时,PDR54、S5和S2表现了良好的矮化效应,其致矮程度分别为44．4％,41．5％和75．2％,属于矮化和半矮化砧木．     

Interleukin-17 stimulates inducible nitric oxide synthase-dependent toxicity in mouse beta cells

The influence of the proinflammatory cytokine interleukin (IL)-17 on inducible nitric oxide (NO) synthase (iNOS)-mediated NO release was investigated in the mouse insulinoma cell line MIN6 and mouse pancreatic islets. IL-17 markedly augmented iNOS mRNA/protein expression and subsequent NO production induced in MIN6 cells or pancreatic islets by different combinations of interferon-γ, tumor necrosis factor-α, and IL-1β. The induction of iNOS by IL-17 was preceded by phosphorylation of p38 mitogen-activated protein kinase (MAPK), and inhibition of p38 MAPK activation completely abolished IL-17-stimulated NO release. IL-17 enhanced the NO-dependent toxicity of proinflammatory cytokines toward MIN6 cells, while IL-17-specific neutralizing antibody partially reduced the NO production and rescued insulinoma cells and pancreatic islets from NO-dependent damage induced by activated T cells. Finally, a significant increase in blood IL-17 levels was observed in a multiple low-dose streptozotocin model of diabetes, suggesting that T cell-derived IL-17 might be involved in NO-dependent damage of beta cells in this disease. Received 14 June 2005; received after revision 17 September 2005; accepted 21 September 2005     

Glutathione synthetase deficiency

Glutathione (GSH), one of the most important antioxidants in the eukaryotic organism, is synthesized in a two-step procedure where the last step is catalysed by the enzyme glutathione synthetase (GSS). GSS deficiency is inherited autosomal recessively, and patients with this disease can be divided into three groups, according to their clinical phenotype. Mildly affected patients have mutations affecting the stability of the enzyme, causing a compensated haemolytic anaemia; moderately affected patients have, in addition, metabolic acidosis; and severely affected patients also develop neurological defects and show increased susceptibility to bacterial infections. Moderately and severely affected patients have mutations that compromise the catalytic properties of the enzyme. 5-Oxoprolinuria appears in all three groups, but is more pronounced in the two latter groups. Today, no cure can be offered these patients; they are given vitamins C and E to boost their antioxidant levels, and bicarbonate to correct metabolic acidosis.Received 20 April 2005; received after revision 19 May 2005; accepted 20 May 2005