H_2O_2诱导Neuro-2a细胞死亡机理的研究

细胞内线粒体呼吸链过程中的电子漏和神经细胞代谢的酶类如单胺氧化酶(MAO)等可产生活性氧物质(ROS)如H_2O_2等。ROS对细胞有毒性作用,导致细胞死亡,在许多疾病特别是神经退行性疾病中具有重要作用。我们用H_2o_2诱导N-2a神经母细胞瘤细胞,利用光镜、荧光显微镜、透射电镜观察了诱导的N-2a细胞的死亡,结果表明其死亡形式不同于典型的细胞凋亡,而类似于Ⅱ型神经细胞编程性死亡,死亡细胞染色质呈团块状凝集,细胞核膜仍保持完整。DNA不降解形成ladder,且不需要caspase-3,1的活性,但是H_2O_2诱导的Neuro-2a细胞死亡可以被Bcl-X_L,抑制。我们的结果可以说明,ROS介导的细胞毒性作用是导致Ⅱ型神经细胞编程性死亡的一个原因。     

8种甜荞的种子消毒

8种甜荞种子表面消毒所适用的消毒剂和处理时间有所不同。10%H2O2溶液处理150min,对榆3-3、黎麻道、浦江荞、龙山荞和富源红花荞的种子有很好的消毒作用,并且处理以后种子仍具有很高的萌发率。8621、B大粒和美国荞种子的消毒以0.1%的HgCl2处理12min效果为好。在无菌苗子叶和下胚轴外植体脱分化形成愈伤组织的过程中,2,4-D起主要作用,BA起独特的作用。BA与2,4-D配合使用对于愈伤组织的诱导和增殖具有良好的促进作用。高浓度的2,4-D或低浓度的2,4-D与BA配合使用都可抑制愈伤组织分化根。     

植物钾离子通道研究现状

对植物钾离子通道的生理生化特性，尤其是植物的钾离子通道基因的结构、功能及转导等方面的研究进展作了较为系统的介绍。     

利用纳米蠕虫摧毁人体肿瘤细胞

科技日报消息：将一种工程材料注射到实验鼠受损的脊髓，就可防止生成疤痕和促进受损神经纤维生长。这种工程材料是美国西北大学材料科学系教授塞缪尔·斯图普研究小组开发的一种液态物质，内含可自组装成纳米纤维的分子，可作为神经纤维生长的支架。斯图普和他的同事在最近一期《神经科学》期刊上发表论文称，使用这种材料治疗后肢瘫痪的小鼠后，实验鼠的后肢恢复了功能。     

今年九月，AnalyticaChina与您再次相约上海!——2006慕尼黑上海分析生化展

第三届中国国际分析、生化技术、诊断和实验室博览会暨AnalyticaChina 2006国际研讨会将于2006年9月19日～21日在上海浦东新国际博览中心召开。这既是中国分析仪器与实验室技术领域的一次行业盛会，又是亚洲的国际级博览盛会，它吸引了来自全球的参展商聚集到中国上海这块被全世界看好的市场上。在其他重要的经济地区，如印度和拉美等地，类似展会也正在筹划中。     

Effects of peach branches returning on autotoxins and microbes in soil and tree growth of peaches

Aims This study aimed to investigate the effects of branch returning on the growth of peach (Amygdalus persica "Chunmei/Maotao") saplings, soil enzyme activity, and soil contents of phenolic acids and amygdalin, thereby providing scientific evidence against the application of branch returning for peach trees. Methods One-year-old potted peach tree (Amygdalus persica "Chunmei/Maotao") was used in this study with four agricultural treatments applied, including soil coverage by fragmented peach tree branches (fragment treatment;1.5 and 22.5 g·kg^-1) and applying leachate solutions of peach tree branches to soil (leachate treatment; 1.5 and 22.5 g·kg^-1). No branch addition was used as control (CK). Solid phase extraction, high performance liquid chromatography (HPLC), biological high-throughput sequencing was used to determine the content of autotoxic substances, and microbial community structure in soil. Soil coverage and leachate solution treatments of 30 g and 450 g branches applied to the peach trees were described as 1.5 and 22.5 g·kg^-1, respectively in this paper.Important findings Compared with CK, the phenolic acid and amygdalin contents significantly increased after both fragment and leachate treatments in high quantities (22.5 g·kg^-1). Soil microbial community structure altered in both treatments, with the proportion of fungi (particularly Agaricomycetes, Tubeufia and Cystofilobasidiaceae) increased significantly and bacteria decreased accordingly. Invertase activity in both high-quantity treatments exceeded that in the CK significantly. The activity of catalase and urease was higher at first and then decreased relative to CK under high-quantity fragment and leachate treatments. Specifically, the effect of leachate treatment on enzyme activity was higher than the fragment treatment in the short term. Chlorophyll content, ground diameter (diameter of 5 cm from the ground) growth and net photosynthesis rate of plants were lower in high-quantity fragment and leachate treatments than those in CK, with earlier retardation of new shoot growth. We observed an increase in soil phenolic acids and enzymes in treatments in normal pruning quantity, while no inhibition effect was found on the tree growth. In conclusion, autotoxins (such as phenolic acid and amygdalin) inhibited the growth of peach trees both directly and indirectly through changing soil enzyme activity and microbial community.     

肺表面活性物质的研究

肺表面活性物质的研究□刘桂萍（吉林省白城师范高等专科学校生物系，白城１３７０００）□付晶（吉林省长春市宽城区中医院，长春１３００５１）肺表面活性物质（ｐｕｌｍｏｎａｒｙｓｕｒｆａｃｔａｎｔ，ＰＳ）这一概念首先是由德国生理学家ＶｏｎＮｅｅ－ｇａａｒｄ在...     

PNAS：研究部分揭示酒精成瘾机制

来自中国科学院武汉物理与数学研究所徐富强课题组的一项最新研究成果，直观地揭示了酒精作为能源物质直接参与大脑的代谢过程。部分解释了酒精成瘾机制。相关论文日前发表于美国《国家科学院院刊》。