比较教学法在“大型数据库系统”课程中的应用

“大型数据库系统”作为计算机专业课,教师在授课过程中应用比较教学法,通过与Access数据库系统、计算机网络、编程语言等先修课相关内容的对比,既可帮助学生理解新的内容,也有助于巩固、扩展已有知识,同时也有助于学生了解本专业的课程体系及相互关系,达到温故而知新、相辅相成的目的。本文介绍了笔者在这方面的教学实践经验。     

OFDMA及其在IEEE802．16-2005中的应用

正交频分多址（OFDMA）是以正交频分复用（OFDM）调制为基础的新一代多址技术,具有很高的带宽利用率。文章介绍了它的基本原理,然后简单介绍了它在移动宽带无线接入中的应用,主要是关于信道编码,链路自适应技术,多天线技术。     

基于ISO 27001:2005的电网公司信息安全管理

随着信息化的持续推进,电网企业的信息安全问题越来越突出。嘉兴电力继2004年引入ITIL服务管理以后,2006年又实现了信息安全的标准化管理,介绍了公司通过引入ISO/IEC 27001：2005,建立一体化的企业级信息安全管理体系的方法。     

简析纸业上市公司2005年业绩及前景

本文简述了2005年造纸业各上市公司的主要业绩，并对其发展前景作了简要分析和展望。     

ISO 22000:2005在调配型酸性双蛋白饮料生产企业的应用

介绍了ISO 22000:2005在调配型酸性双蛋白饮料生产企业的应用,分析了调配型酸性双蛋白饮料生产过程的主要食品安全危害,确定了关键控制点,并制定了HACCP计划.     

全球造纸工业发展报告(2005)(续二)

目前，全球造纸行业集中度整体上并不是很高，仍处于一个竞争程受较高的垄断竞争型市场结构；但是北美和欧洲已经处于寡头垄断的市场结构；亚洲基本处于垄断竞争的市场结构；中国的市场集中度仍然相当低，但是处于快速提高的趋势。     

Microbiological contamination of pig and cattle carcasses in different small-scale Swiss abattoirs

A total of 750 pig carcasses and 535 cattle carcasses from 17 small-scale abattoirs were sampled by excision at four sites (pig: neck, belly, back, ham; cattle: neck, brisket, flank, rump). Samples were examined for total viable counts (TVC) and Enterobacteriaceae. Mean TVCs ranged from 2.4 to 4.2 log(10)CFUcm(-2) on pig carcasses and from 2.7 to 3.8 log(10)CFUcm(-2) on cattle carcasses. With regard to EU Regulation (EC) No 2073/2005, TVCs were mainly considered satisfactory (pig: 81.3%; cattle: 71.4%). Amongst sites, the back (pigs) and neck (cattle) tended to yield higher TVCs. Enterobacteriaceae were detected in low counts on 23.9% of pig carcasses and 21.7% of cattle carcasses. Amongst abattoirs, Enterobacteriaceae prevalence on pig and cattle carcasses ranged from 2.0% to 56.0% and from 0.0% to 55.0%, respectively. Consequently, criteria of the EU Regulation proved to be a suitable tool for the appraisal of microbiological results (TVCs) from pig and cattle carcasses from small-scale abattoirs. Because the occurrence of Enterobacteriaceae on carcasses was too infrequent to ensure log normality, frequencies should be compared for these organisms.     

钢丝绳旋转性能测定及研究

钢丝绳承受载荷时,绝大多数结构的钢丝绳会绕其自身轴线旋转,旋转是钢丝绳难以克服的特性。介绍ISO 21669:2005给出的吊钩提升重物测定装置存在的缺点。设计了利用材料试验机测定钢丝绳旋转性能的新型测定装置,并选取典型结构的钢丝绳进行长度为直径100和150倍的旋转度试验,经过换算,得出长度为直径1 000倍的钢丝绳旋转的圈数偏差在0~1.7圈,证实了钢丝绳的旋转特性和抗旋转钢丝绳的优越性。新型测定装置优点:加载方便、安全;旋转角度测量精度高,可测定钢丝绳扭矩;测试范围广。     

The Casein Kinase 2‐Dependent Phosphorylation of NS5A Domain 3 from Hepatitis C Virus Followed by Time‐Resolved NMR Spectroscopy

Hepatitis C virus (HCV) chronically affects millions of individuals worldwide. The HCV nonstructural protein 5A (NS5A) plays a critical role in the viral assembly pathway. Domain 3 (D3) of NS5A is an unstructured polypeptide responsible for the interaction with the core particle assembly structure. Casein kinase 2 (CK2) phosphorylates NS5A‐D3 at multiple sites that have mostly been predicted and only observed indirectly. In order to identify the CK2‐dependent phosphorylation sites, we monitored the reaction between NS5A‐D3 and CK2 in vitro by time‐resolved NMR. We unambiguously identified four serine residues as substrates of CK2. The apparent rate constant for each site was determined from the reaction curves. Ser408 was quickly phosphorylated, whereas the three other serine residues reacted more slowly. These results provide a starting point from which to elucidate the role of phosphorylation in the mechanisms of viral assembly—and in the modulation of the viral activity—at the molecular level.     

Structure–Activity Relationships of JMV4463, a Vectorized Cathepsin D Inhibitor with Antiproliferative Properties: The Unique Role of the AMPA‐Based Vector

Cathepsin D (CathD) is overexpressed and secreted by several solid tumors and stimulates their growth, the mechanism of which is still not understood. In this context, the pepstatin bioconjugate JMV4463 [Ac‐arg‐O₂Oc‐(Val)₃‐Sta‐Ala‐Sta‐(AMPA)₄‐NH₂; O₂Oc=8‐amino‐3,6‐dioxaoctanoyl, Sta=statine, AMPA=ortho‐aminomethylphenylacetyl], containing a new kind of cell‐penetrating vector, was previously shown to exhibit potent antiproliferative effects in vitro and to delay the onset of tumors in vivo. In this study, we performed a structure–activity relationship analysis to evaluate the significance of the inhibitor and vector moieties of JMV4463. By modifying both statine residues of pepstatin we found that the antiproliferative activity is correlated with CathD inhibition, supporting a major role of the catalytic activity of intracellular CathD in cancer cell proliferation. Replacing the vector composed of four AMPA units with other vectors was found to abolish cytotoxicity, although all of the conjugates enabled pepstatin transport into cells. In addition, the AMPA₄ vector must be localized at the C terminus of the bioconjugate. The unexpected importance of the vector structure and position for cytotoxic action suggests that AMPA₄ enables pepstatin to inhibit the proteolysis of critical CathD substrates involved in cell proliferation via a unique mechanism of action.