Study on Oxidativestress and Bioaccumulation of Three Typical Brominated Flame Retardants in Oryzias melastigma Embryos

多溴联苯醚(Polybrominateddiphenylethers,PBDE)、四溴双酚A(TetrabromobisphenolA,TBBPA)和六溴环十二烷(Hexabromocyclododecane,HBCD)是目前世界上广泛使用的三大溴代阻燃剂(brominatedflameretardants,BFRs)。由于它们的亲脂性、环境稳定性、在生物体中的富集放大作用以及对水生生态系统和人体健康产生一定的毒性效应而受到各界的广泛关注和重视。本研究选取BDE-47、TBBPA和HBCD三种典型溴代阻燃剂，研究其对海洋模式鱼类-海水青鳉(Oryziasmelastigma)胚胎的毒性效应和可...Polybrominated diphenyl ethers (PBDE), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are the most widely used brominated flame retardants (BFRs). As the additive or the reactive flame retardants, they are likely to release into the environment due to the rapid growth in their production and usage. They are concerned greatly due to their lipophilic, environmental stability and bio...学位：理学硕士院系专业：环境与生态学院_环境科学学号：2262010115141

A Study on Determinants of Investment Return of Private Placements in the Primary Market

近年来，我国定向增发发展势猛，不仅成为上市公司广泛采用的股权再融资方式，也成为广大投资者日益青睐的投资热点。而投资者除了可以利用公告效应在二级市场买卖股票进行套利之外，还可以直接在一级市场参与定向增发股份认购。但以往针对定向增发投资价值的研究主要是从二级市场投资者的角度出发，探讨定向增发的短期公告效应和长期股价反应，本文则站在一级市场投资者的视角，对定向增发解禁时的投资回报问题进行了探讨，试图为一级市场投资者的认购决策提供一定的意见，也为企业如何通过定向增发来实现股权价值最大化提供一定的思路。 本文利用2006~2013年之间进行定向增发并已解禁的上市公司为样本，从定向增发特点、发行公司特点...In recent years, the private placement has developed rapidly, which has become not only the most important refinancing way among listed companies but also a popular investment choice in capital market. While the previous studies on the investment value of private placement were mainly from the perspective of investors in secondary market to discuss the announcement effect and long-term stock price...学位：管理学硕士院系专业：管理学院_会计学学号：1752012115112

维吾尔族肺腺癌患者的EGFR基因突变分析

背景与目的表皮生长因子受体(epidermal growth factor receptor,EGFR)是一种跨细胞膜糖蛋白,属于受体型酪氨酸激酶家族。以吉非替尼为代表的EGFR酪氨酸激酶抑制剂对于EGFR突变的肺癌患者显示出良好的治疗效果,然而EGFR的突变率在不同民族和不同种族的人群中表现出较大差异。本研究旨在分析维吾尔族中肺腺癌患者肿瘤组织的EGFR基因突变情况,同时比较维吾尔族与汉族肺腺癌患者肿瘤组织EGFR基因突变率的差异性。方法收集临床肺腺癌患者石蜡包埋组织标本138例,包括68例维吾尔族和70例汉族肺腺癌的样本,采用ARMS(amplification refractory mutation system,ARMS)PCR扩增方法检测EGFR基因外显子18、19、20及21的突变,χ2分析对比维吾尔族和汉族肺腺癌EGFR基因突变差异。结果 138例肺腺癌患者中有43例EGFR基因突变,总突变率为31.2%,其中维吾尔族突变11例,突变率为16.2%,汉族突变32例,突变率为45.7%,维吾尔族肺腺癌EGFR突变率与汉族肺腺癌EGFR突变率比较有明显差异(P<0.001),突变以外显子19-del和L858R为主要突变点。结论维吾尔族中肺腺癌EGFR基因突变率为16.2%,汉族中EGFR基因突变率为45.7%,维吾尔族肺腺癌EGFR突变率明显低于我国汉族EGFR基因突变

The Intermetallic Catalysts for Oxidative Esterification of Methacrolein to Methyl Methacrylate

A series of supported intermetallic Pb-Pb catalysts were prepared with the impregnation method by changing the support(silica,molecular sieve or &gamma;-alumina)and the pore size.The chemical states of the two metals were characterized by XPS analysis,the process for producing methyl methacrylate based on the direct oxidative esterification of methacrolein with methanol in the presence of oxygen was performed in a slurry reactor with the above-mentioned catalysts.The influence of the calcination temperature and the kinds of support as well as the pore size on catalytic activity had been extensively investigated.Under the conditions of temperature at 80℃,catalyst 3.8%(&omega;)and the reaction time 2 h,the conversion rate of methacrolein reached 85%,the selectivity and the yield of methyl methacrylate were 90% and 76.5%,respectively

青鳉防御素OlBD的活性分析

防御素是一类富含半胱氨酸的阳离子抗菌肽,它是机体抵御病原入侵的一道天然屏障。防御素分子可以直接作用并杀死细菌、真菌和病毒等病原微生物。本研究利用实验室已克隆到的石斑鱼的 EcBD 基因序列同青鲻基因组进行 blast 比对, 获得到了同 EcBD 高度保守的青鳉防御素基因 OlBD 的基因组序列。提取青鳉精巢组织 RNA,构建 SMART cDNA 文库,根据基因的基因组序列设计引物进行3'RACE 和5'RACE

石斑鱼防御素bd2基因在毕赤酵母中的分泌表达及纯化

防御素是一类具有广谱抗菌活性的小分子物质;是生物体天然免疫反应系统的重要成员。其分布十分广泛;脊椎动物、无脊椎动物和植物上都有发现。大多可抑制革兰氏阴性菌、革兰氏阳性菌、真菌及部分病毒等。除此之外;有些抗菌肽还具有其它功能;如释放细胞因子、趋化因子等

青鳉防御素bd2基因的启动子分析

防御素是一类天然的免疫小分子蛋白,具有非特异的抗菌抗病毒活性,是机体抵御病原入侵的一道天然屏障。目前的防御素研究主要集中在哺乳动物等高等物种中,对鱼类的防御素研究尚还处于刚起步阶段