一株碱性淀粉酶产生菌Bacillus flexus XJU-3的分离鉴定及酶学特性分析

[目的]从新疆石河子市一处碱性工业污水(pH11.0)分离﹑鉴定高产碱性淀粉酶菌株,并对其所产酶酶学特性进行研究.[方法]在碱性淀粉酶分离培养基上对所分离菌株进行筛选,分离到一株高产碱性淀粉酶菌株,并将其编号XJU-3.应用生理生化试验,脂肪酸含量,16S rDNA序列以及(G C) mol%含量等方法对菌株进行鉴定,同时对XJU-3所产碱性淀粉酶的生物学特性进行研究.[结果] XJU-3可在pH4.0～12.5的LB培养基上生长,最适生长温度37℃.16S rDNA序列构建的系统进化树表明XJU-3与Bacillus flexus类聚在一起,且序列同源性为99%.该菌产生的淀粉酶最适pH10.0,最适温度40℃,且在pH9.0～13.0内有较高活性和稳定性.Co2 和Mg2 能明显提高酶的活性.[结论] XJU-3被鉴定为Bacillus flexus,由于XJU-3与B. flexus DSM 1320T在尿素水解和优势脂肪酸含量上有差异,且具有宽范围pH耐受性,因此XJU-3被认为是B.flexus的一个新菌株.XJU-3所产的碱性淀粉酶酶学特性良好,具有极大的工业应用潜力.     

骨髓间质干细胞移植治疗大鼠脑出血模型的实验研究

目的:研究大鼠骨髓间质干细胞(MSCs)移植治疗脑出血的可行性。方法:分离MSCs后,连续传代培养、扩增,Brdu标记的MSCs通过颈动脉、侧脑室2种途径移植入脑出血大鼠模型体内,采用爬行计分法评估神经功能的恢复程度,并观察脑部Brdu阳性细胞的分布。结果:通过侧脑室、颈动脉移植后大鼠神经功能改善,明显优于对照组(P<0.05);经颈动脉注射组较经侧脑室注射组爬杆实验评分低(P<0.05)。移植的MSCs主要迁移到出血灶、大脑皮层、海马区等处。结论:MSCs移植对脑出血具有保护作用,而经颈动脉给药疗效优于经侧脑室给药。     

局灶性脑缺血再灌损伤时神经细胞内Ca~(2+)时空动态变化的实验研究

本文用插线法制作局灶性脑缺血／再灌损伤模型,利用激光共聚焦扫描显微镜观察活体脑片细胞内Ｃａ２＋的分布及动态变化,结果表明：（１）缺血／再灌时间不同,梗塞面积不同,缺血４小时梗塞面积占同侧半球的１６．３％,缺血４小时再灌２０小时梗塞面积增加到２５．９％,缺血２４小时梗塞面积占同侧半球的６０．４％。（２）本文首次观察到在缺血４小时纹状体区域的Ｃａ２＋变化明显高于皮层,并且再灌后皮层及纹状体区域Ｃａ２＋的含量明显增加     

Potential role of cyanidin 3-glucoside (C3G) in diabetic cardiomyopathy in diabetic rats: An in vivo approach

The present study aimed to evaluate the importance of cyanidin 3-glucoside (C3G) of diabetic cardiomyopathy in diabetic rats. The rats were induced with diabetic using streptozotocin and total triglyceride (TG) and total cholesterol (TC) were determined. The range of myocardial enzymes such as aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LD) were also estimated, further, the Immuno histochemical analysis and western blot investigation were determined for the actual activity of C3G. Results indicated that the marker enzymes such as CK, LD and AST were significantly (P < 0.05) increased in STZ administered rats (DM group), while the levels of these elevated marker enzymes of cardiac injury significantly (P < 0.05) declined in the DM + C3G group, as compared to the diabetic group of rats. Additionally, a decrease in the level of TNF-alpha and interleukin-6, was noticed in the C3G treated group as compared to diabetic group. Finally, blotting analysis clearly confirmed that theC3G treatment resulted to higher level response of Bcl-2 and lower level response of caspase-3 and BAX. In conclusion, C3G a natural antioxidant may prevent cardiovascular complications by ameliorating oxidative damage, inflammation, metabolic dysfunctions and apoptosis pathways in type 2 diabetes.     

《蛛形学报》(1992～2001年)学术论文计量分析

采用文献计量的方法分析了《蛛形学报》（1992～2001)发表的学术论文、刊物特色、作者地区、单位分布,引文概况,并就进一步推动《蛛形学报》的发展提出了建议。     

紫云英根瘤菌159中两个结构和功能不同的nodD基因

紫云英根瘤菌159含2个拷贝的nodD基因。核苷酸序列测定表明由nodD1和nodD2基因所推定编码的nodD1和nodD2蛋白其氨基酸顺序同源性为69％。功能分析显示,在紫云英根瘤菌中nodD1和nodD2基因均能自主表达。由nodD1推定的nodD1能与紫云英种子浸出液（诱导物）共同激活nod基因的表达,而由nodD2推定的nodD2则无此功能。     

Development of silver-containing austenite antibacterial stainless steels for biomedical applications Part I: microstructure characteristics,mechanical properties and antibacterial mechanisms

The as-quenched (AQ) microstructure of the Ag-containing alloys was found to be essentially a mixture of austenite (γ) and Ag phases. The Ag phase precipitates had a face-centered-cubic structure and lattice parameter a = 4.09 Å. When the alloy contained Ag ≥0.2 wt%, the mechanical properties were slightly enhanced because of the precipitate strengthening by the Ag phase precipitates. Moreover, the Ag-containing alloys exhibited ductile fracture after tensile testing. The results of an antibacterial test revealed that the Ag phase precipitates play a key role in the antibacterial mechanism of Ag-containing alloys: Ag⁺ ions released from the Ag phase precipitates can kill bacteria. It is suggested that as AISI 316L alloy has an Ag content ≥0.2 wt%, it will have excellent antibacterial properties against both Staphylococcus aureus and Escherichia coli, with an antibacterial rate of nearly 100%.     

泛素、泛素链和蛋白质泛素化研究进展

蛋白质泛素化是以泛素单体和泛素链作为信号分子,共价修饰细胞内其他蛋白质的一种翻译后修饰形式。不同蛋白质底物、同一底物的不同氨基酸修饰位点以及同一位点上泛素链连接方式的不同均可导致细胞效应的差异。蛋白质泛素化在真核细胞内广泛存在,除了介导蛋白质的26S蛋白酶体降解途径之外,还广泛参与了基因转录、蛋白质翻译、信号传导、细胞周期控制以及生长发育等几乎所有的生命活动过程。泛素链的形成及其修饰过程的任何失调均可导致生物体内环境的紊乱,从而产生严重的疾病。文中结合实验室研究,综述了泛素的发现历史、基因特点、晶体结构,特别是泛素链的组装过程、结构、功能以及与人类相关疾病关系的新进展,可为这些疾病的治疗靶点和药物靶标的研究提供思路。     

海南橡胶林植物多样性特征

为探讨人工林物种多样性维持机制及人为干扰后人工林群落的多样性恢复机制, 作者依据自然林的核心理论建立了一个1 ha的橡胶(Hevea brasiliensis)林固定样地, 通过研究近自然管理后样地内植物物种组成与分布来探讨近自然管理后橡胶林生物多样性的特征。结果表明: 近自然管理后橡胶林群落物种多样性较高, 1 ha样地内共有植物69科155属183种。在面积为4,000 m²、3,000 m²和2,000 m²时分别包含了样地内大约90%的种、属和科; 逻辑斯蒂模型拟合拟合种-面积曲线效果较好(R²=0.997), 证明了1 ha取样尺度可以满足橡胶林群落物种多样性研究的需要。多度-面积曲线和丰富度-面积曲线与随机分布模型有明显的差异, 表明橡胶林群落内个体数及物种分布呈非随机性。(4)对数级数模型和对数正态模型拟合橡胶林群落的种-多度分布都不理想, 相比而言后者拟合效果稍好。     

L-亮氨酸发酵培养基优化试验

应用Plackett-Burman设计试验从L-亮氨酸基础发酵培养基的10种成分中筛选出5种重要成分,然应用响应面分析试验确定5种重要成分的最适用量。培养基优化后摇瓶分批发酵72h产L-亮氨酸18.05g/L