纳米硫化镉在对氨基苯硫酚自组装单层修饰金电极上的电化学合成

采用电流脉冲法在自组装了对氨基苯硫酚单层的金电极(PATP/Au)上电沉积硫化镉(CdS)纳米薄膜,运用扫描电子显微镜(SEM)和X射线衍射谱(XRD)对其形貌和结构进行了表征,发现得到的是垂直基底生长的CdS纳米棒有序阵列.研究电沉积中电流脉冲参数的影响时发现:随着电流脉冲宽度增大,CdS纳米棒的尺寸增大,有序性降低;脉冲幅度增大,则纳米棒尺寸增大,覆盖度也随之增大.因此通过调节脉冲宽度和脉冲幅度,可对所制备的CdS纳米薄膜的形貌和尺寸进行调控.运用循环伏安法和计时电位法对电沉积机理进行了探究.根据实验结果我们认为Au电极自组装PATP单分子层后,PATP分子中的-NH2与溶液中Cd2+相互作用,使沉积时的电子通过表面的PATP分子链进行传递.并进一步提出纳米CdS在PATP/Au电极上电化学合成的生长机理

伺服运动控制器的调试方法研究

数控机床各进给轴伺服驱动器的参数设置是机床整机调试的一项重要工作。合理的参数设置,是保证机床的加工精度、运行平稳性等基本性能的关键因素之一。通过具体的实践总结,介绍伺服驱动器相关参数设置的基本原则、方法和过程,为数控机床厂商及用户的设备调试与维护提供良好的借鉴

综合化学实验——DMB的绝对不对称合成和表征

介绍一个可用于化学系本科生开设的综合化学实验。该实验构思源于手性对二甲氨基苯甲醛缩氨基苯硫脲(DMB)的绝对不对称合成。学生可通过实验发现、观察和探究手性对称性破缺的奇妙现象,并掌握标题化合物组成、结构和手性性质的各种表征方法,特别是固体圆二色(CD)光谱方法

Cloning and sequence analysis of hepcidin-like cDNA Hepc2 from liver of Lateolabrax japonicus

Hepcidin(Hepc)是一类性质独特的抗菌肽,具有广谱的抗革兰氏阳性、阴性细菌和真菌等作用。利用RT-PCR和RACE等技术,从经过多种细菌攻毒的花鲈(Lateolabrax japonicus)肝组织中克隆出Hepc全长cDNA,命名为Hepc2,Genbank登录号为AY604195。Hepc2有581个碱基,其中阅读框有258个碱基,编码86个氨基酸。预测氨基酸序列和白鲈及其他鱼种在相同保守的区域有8个半胱氨酸,相对分子量为9418.55dal。在3’非编码区有225bp,包含终止密码子下游189nt处的多腺苷酸化AATAAA信号和212nt处的polyA信号。预测蛋白的信号肽断裂位点在第24和第25个密码子之间。通过与白鲈(Morone chrysops)、人和其他鱼种来源的Hepc cDNA和蛋白质同源性分析表明,从花鲈肝中分离的Hepc2 cDNA属于Hepc基因家族的新成员。Hepcidin is a unique antimicrobial peptide which exerts broad-spectrum antimicrobial action against Gram-negative and Gram-positive bacteria,as well as fungi.A Hepc-like cDNA was amplified from the liver of Lateolabrax japonicus challenged with a mixed bacteria solution.Using RT-PCR and RACE with a specific primer pair,a full length cDNA sequence Hepc2 of the Hepc-like antimicrobial peptide(GenBank accession number:AY604195) was obtained.Hepc2 cDNA is composed of 581 bases,which contains an ORF of 258 bases,encoding 86 amino acids.The deduced amino acid sequence is conserved between white bass and other fish species,which share eight cysteines at the identical conserved position.The relative molecular weight of the protein is 9418.55dal.The 3′non-coding region is composed of 225bp,with a polyadenylation signal AATAAA sequence appearing at position 189 nt,and poly(A) tail at 212 nt,downstream codon TAA.The signal peptide cleavage site of its deduced protein is presumed between codon 24 and 25.High homologies with Hepc cDNAs and proteins of white bass(Morone chrysops),human and other fish are shown.It indicates that Hepc2 cDNA from Lateolabrax japonicus liver is a new member of the Hepc gene family.福建省重大科技项目(2003I005);; 厦门市高新技术项目(3502Z20021052)资

不同等电点的魟鱼肝铁蛋白释放铁速率的比较研究

选用热变性法、离子交换层析技术和聚丙烯酰胺凝胶电泳技术(PAGE)小批量制备电泳纯魟鱼肝铁蛋白(Liverferritin ofDasyatis akajei,DALF)和黄牛胰脏铁蛋白(Scalper pancreas ferritin,SPF).等电聚胶电泳技术指出,DALF和SPF分别显示3和2条不同等电点铁蛋白层析带,推测这一现象与铁蛋白含铁量无关,与各自蛋白壳H和L亚基分布不同且形成不同表面电荷有关.不同等电点且相同含铁量的DALF,表现出不同的释放铁速率,其释放铁全过程均可分为快速和慢速阶段,符合一级反应动力学规律.铁蛋白可通过自身蛋白壳H和L亚基分布和相互作用强度的差异性,产生不同的柔性调节作用,控制不同释放铁的速率

モバイルバンキングへの利用意欲に影響する要因に関する一考察

Although millions of dollars have been spend on building mobile banking systems, report on mobile banking systems has shown that potential users may not use the systems in spite of their availability. There is a need for research to identify the factors that determine users\u27 acceptance of mobile banking. According to the technology acceptance model (TAM), perceived ease of use and perceived usefulness constructs are believed to be fundamental in determining the acceptance and use of various IT. These beliefs, however, may not fully explain the user\u27s behavior toward the newly emerging mobile banking. Using the technology acceptance model (TAM) as a theoretical framework, this study introduces "perceived credibility" as a new factor that reflects the user\u27s security and privacy concern in the acceptance of mobile banking, and examines the effect of computer self-efficacy on intention to use mobile banking. Data collected from 267 users in Taiwan were tested against the extended TAM using the structural equation modeling approach. The results strongly support the extended TAM in predicting users\u27 intention to adopt mobile banking systems, and demonstrate the significant effect of computer self-efficacy on behavioral intention through perceived ease of use, perceived usefulness, and perceived credibility

Challenge by Head Transplant

范瑞平：诸位好!受《中国医学伦理学》杂志王明旭主编所托,组织一篇＂换头术的挑战＂争鸣笔谈,特邀各位参与。请踊跃发表意见,观点不拘,长短不限,畅所欲言,各抒己见,若能针对已发观点形成争论,则更能增加读者兴趣

SARS-CoV N蛋白与人冠状病毒HCoV-OC43和HCoV-229E的交叉反应表位及特异表位的确定

为确定SARS-CoV N蛋白的特异抗原表位,对3种人冠状病毒SARS-CoV、HCoV-OC43和HCoV-229E N蛋白之间的交叉免疫反应进行了系统研究。构建了分别表达SARS-CoV、HCoV-OC43和HCoV-229E N蛋白的重组痘苗病毒,并制备了相应的小鼠免疫血清。用间接免疫荧光方法,检测了3种N蛋白的表达及其与3种冠状病毒免疫动物血清和SARS病人恢复期血清之间的反应。与此同时,用Western blot方法分析了原核表达的39个不同区段的SARS-CoV N蛋白与3种冠状病毒动物免疫血清和SARS病人恢复期血清之间的交叉反应性。免疫荧光检测结果表明,SARS-CoV、HCoV-OC43和HCoV-229E3种病毒的N蛋白在重组痘苗病毒感染的HeLa细胞中均可以特异表达;3种N蛋白之间存在明显交叉免疫反应。Western blot结果显示,SARS-CoV N蛋白的表位主要位于30~60aa、170~184aa、301~320aa和360~422aa;与HCoV-OC43的交叉反应表位主要位于30~60aa、90~120aa、204~214aa和320~360aa;与HCoV-229E的交叉反应表位主要位于30~60aa、150~160aa和301~360aa。含SARS-CoV N蛋白特异表位的重组肽N155b(60~214aa)和N185(30~214aa)只与SARS病人恢复期血清和灭活SARS-CoV免疫小鼠的血清反应,而不与灭活HCoV-OC43和HCoV-229E免疫的山羊血清产生交叉反应。上述结果为使用SARS-CoV N蛋白抗原进行特异诊断试剂的研究,提供了重要的实验依据