Study on the Production of (+)-Brefeldin A by Fermentation and Synthesizing Derivatives of (+)-Brefeldin A

摘要布雷菲徳菌素A（(+)-BrefeldinA，简称BFA），是一种大环内酯类抗生素，它具有多种生物活性，如抗真菌、抗病毒、抗线虫和抗肿瘤等。(+)-BrefeldinA的主要功能是能诱导高尔基体的分解，抑制蛋白从内质网(ER)中转移为高尔基体的复合物，从而阻断高尔基体复合物的蛋白质传输。目前被作为一种重要的分子工具广泛用于研究哺乳动物的信号传导途径，国际肿瘤协会发现(+)-BrefeldinA能够诱导肿瘤细胞分化和凋亡，作为化学治疗试剂用于抗肿瘤有很大的应用前景。鉴于(+)-BrefeldinA具有多种生物活性及潜在的药用价值，故开发和研究(+)-BrefeldinA的工作已备受关注。本文...ABSTRACT (+)-Brefeldin A （BFA）is a macrocyclic lactone antibiotic , it possesses a diverse array of biological activities including antiviral, antifungal, nematocidal and antitumor effects. It was reported that (+)-Brefeldin A inhibited protein transport from the endoplasmic reticulum to the Golgi apparatus causes reversible disassembly of the Golgi complex, and blocks protein transport be...学位：理学硕士院系专业：化学化工学院化学系_有机化学学号：20032504

不同气氛下热处理对CO甲烷化催化剂性能的影响

采用液相包裹法制备了Ni/Al2O3耐高温甲烷化催化剂,并分别在静态空气、动态氮气及动态空气气氛条件下程序升温到550oC,恒温煅烧,得到不同气氛下热处理的三种催化剂。通过BET,H2-TPR,XPS等一系列的表征分析结果显示,经过动态气氛下煅烧的催化剂在高温和低温都具备良好的活性,其具有较大的比表面积,且流动性的气体可以有效的降低催化剂中镍与载体的结合力,主要表现在氧化镍的化学位能降低0.5eV,镍更易于还原

预涂布晶种法合成无缺陷A型分子筛膜的研究

采用一种颗粒度约为 2 0 0 nm的胶态 A型分子筛为晶种源 ,对晶种层进行特殊的蒸气处理后 ,进一步采取原位水热晶化法 ,在多孔氧化铝载体表面制备出 A型分子筛膜 .膜分子筛以特殊的孪生聚晶形式生长在一起 ,可有效地消除晶粒间隙 ,形成致密的分子筛膜层 .晶化反应液的碱度对 A型分子筛膜的质量影响很大 ,低碱度更有利于 A型分子筛膜的生长 .在对分子筛膜进行高温活化处理过程中产生一些缺陷孔 ,降低了膜气体分离性

产胞外布雷菲德菌素A青霉发酵条件的研究

通过正交设计试验,优化了青霉(Penicillium)属真菌SHZK-15产胞外布雷菲德菌素(B refeld in-A,简称BFA)的液体发酵条件。最佳的BFA发酵条件为:培养基含马铃薯200g(煮汁),葡萄糖20g,(NH4)2SO44.0g,KH2PO41.0g,MgSO4.7H2O 2.0g,CaCO35.0g,pH自然,瓶装量为100mL/250 mL,培养温度为28℃,转速为120 r/m in,培养时间为7d,BFA的最高产量可达151.6mg/L

Analysis of the Festo CLR Cylinder Performance

本文对Clr气缸工作性能的实验研究,目的是为了满足数控机床气动随行夹具中气缸的旋转夹紧要求。利用PlC控制器、气阀、气缸、传感器等元器件搭建实验平台。对主要实验步骤进行详细分析,通过实验论证fESTO Clr直线摆动夹紧气缸完全满足气动随行夹具工作要求。In this paper,we introduced an experiment to study the performance of pneumatic cylinder.In order to meet the requirements of the line/rotation clamping cylinder in CNC machine tools pneumatic clamp accompanied system.Using PLC controller,valves,cylinders,sensors and other components to build an experimental platform,the main experimental steps have been analyzed in details.Through the different kinds of experimental data demonstrating the Festo CLR line/rotation clamping cylinder is fit for the requirement of practical work

The effect of phosphoryl oxygen on the intermolecular action of alanine and lysozyme

It was found that N-diisopropyloxyphosphoryl alanine (DIPP-Ala) could form adduct with hen egg white lysozyme (HEWL) as shown in electrospray ionization mass spectroscopy (ESI-MS), but the non-phosphorylated alanine couldn't. The capability for formation of DIPP-Ala dimmer was more stronger than that of alanine. It suggested that a specific non-covalent complex was formed in the solution phase and could be transferred to the gas phase via electrospray ionization (ESI). The results implied that phosphorylated alanine possessed relatively stronger affinities for protein and formed non-covalent complexes with protein more easily than alanine. Using Tripos force field, molecular mechanics calculation on DIPP-Ala dimmer showed that such non-covalent adduct formation was due to the intermolecular hydrogen bond

The application and research of the aircraft flexible fixture

主要研究气动、液压与电传技术在航空制造业中装配工艺中的应用。对研制出数控机床气动柔性夹紧系统,及其在飞机上零件加工上的应用进行了详细论述,包括柔性系统的机构组成、工作原理及PlC控制系统。该技术的突破为我国飞机数字化加工装配提供了参考价值,并将促进航空制造业的跨越式发展。The application of the pneumatic,hydraulic and power transmission for assembly process and equipment in aviation manufacturing industry is study.A novel type of CNC Aircraft Flexible Fixture machine system has been made out,and applied in manufacturing the aircraft parts.The system is including in architecture of the composition,working theory,PLC control system.It has a great signification of the manufacturing technology for aircraft digital processing,manufacturing and assembling,and promoting the developing of aircraft manufacturing

The Effect of Stock Dividend on Shareholders' Value:Evidences from Chinese Listed Companies

以2008、2009年的送转股除权日进行事件研究,通过均值比较与检验方法,首次实证研究我国上市公司送转股后股价变化对股东财富的影响,结果发现:相对于经过调整的除权前一日的股价,2008年股票除权后,股价以高于送转股的比例单调下降;而2009年股票除权后,股价呈上升趋势,并于第14日显著高于经过调整的除权前一日的股价。除权后20天内的股价整体上高于年末股价,说明相对基于年末股价的股利决策,送转股没有降低股价。企业发放股票股利,导致股票总市值上升,增加了股东财富。Based on the mean comparison and test method,the paper firstly makes an empirical research on the stock prices change before and after ex-dividend of Chinese listed companies through 2008 to 2009 and its influence on shareholders' value.The results show that: compared to the adjusted stock prices the day before ex-dividend day,the stock prices decline monotonously faster in 2008;however,the stock prices rise in 2009,and are significantly higher than the price on the day before ex-dividend day after 14th day;the stock prices within 20 days are higher than the year end stock price,which suggests that compared to the decision-making based on the year-end stock price,stock dividend policy does not reduce the stock prices,in fact,it increases the companies' total market value and shareholders' wealth.教育部人文社会科学重点研究基地2009年度重大项目“我国证券市场财务分析师信息引导机制及其监管研究”(2009JJD790041

An Empirical Study of Motivations behind Stock Dividends in China's Listed Companies

股利分配是公司财务政策的重要内容,也是我国证监会近年来监管的重点。中国现行的经济状况和世界其他国家相比有着不同的发展轨迹和制度背景,目前在该领域的研究并不能完美地解释股票股利政策的公司行为。基于中国特定的制度背景,以我国2009年4月30前公布的分配预案中有送转股的上市公司为样本,实证研究股本扩张动因对送转股的影响。结果显示,我国上市公司股本规模对送转股数有显著影响。Dividend distribution is an important element of a company's financial policy,and has been the focus of supervision of China's Securities Regulatory Commission in recent years.As China has taken a different route of economic development and has a different institutional background from other countries,previous researches cannot perfectly explain the corporate behavior of the stock dividend policy.Considering China's institutional particularities and taking companies that announced stock dividend plans before April 30,2009 as samples,our empirical study looks into the impact of capital stock expansion on stock dividend and concludes that that the capital stock sizes of China's listed companies have a significant impact on their amount of stock dividends.教育部人文社会科学规划项目“信息化环境下企业内部控制研究”(06JA630060);2007年福建省高等学校新世纪优秀人才支持计划项目(0000-X071R9