黄芩甙的极谱研究

用单扫示波极谱法研究了黄芩甙的电化学特性．在０．０５ｍｏｌ／Ｌ柠檬酸钠＋０．２ｍｏｌ／ＬＨＣｌ底液中,黄芩甙于－１．１６Ｖ（Ｐ１）和－１．３４Ｖ（Ｐ２）（ｖｓ．ＳＣＥ）处产生两个二阶导数峰,前者为黄芩甙分子的还原波,后者为其一价阴离子的还原波,均为羰基的双电子还原波．利用峰Ｐ１可测定黄芩甙,线性范围为０．１６～０．６４ｍｇ／Ｌ和０．７２～２４ｍｇ／Ｌ,检测限为０．０８ｍｇ／Ｌ．将该法用于中药黄芩中黄芩甙的测定时,获得满意结果     

108例病毒性肝炎患者血清补体的研究

报告１０８例病毒性肝炎患者血清总补体（ＣＨ＿（５０））和Ｃ＿３值的检测结果：急性肝炎的ＣＨ＿（５０）为６８．４±６．１３单位／ｍｌ，Ｃ＿３为１３０．２±６．６７ｍｇ％，均高于正常组（ＣＨ＿（５０）为４８．５±５．７５单位／ｍｌ，Ｃ＿３为１０２±５ｍｇ％），Ｐ＜０．０１；其他类型的肝炎患者组的补体均低于正常组，Ｐ＜０．０１．补体的含量与Ｔ细胞花环（Ｅｔ花环）呈中度相关，与ＧＰＴ呈高度相关，因此测定ＣＨ＿（５０）和Ｃ＿３可作为衡量患者机体免疫功能和判断病毒性肝炎预后的指标之一。     

sICAM-1在牙周炎患者龈沟液中的含量

研究了牙周炎患者龈沟液可溶性细胞间粘附分子（ｓ Ｉ Ｃ Ａ Ｍ １）的含量⒚牙周炎患者 ２３ 例,４６ 个牙齿;正常对照２０ 例,２０ 个牙齿,用 Ｅ Ｌ Ｉ Ｓ Ａ 法检测牙周炎患者龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 的含量⒚正常对照龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 含量为（１４５．０１４±４３．７４５）ｎｇ／ｍ Ｌ ,男女间无显著性差异（ Ｐ＞ ０．０５）⒚牙周炎患者龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 的含量为（２５．３８９±８．４６１）ｎｇ／ｍ Ｌ,明显低于正常对照（ Ｐ＜ ０．０１）;一个牙齿３０ 秒龈沟液 ｓ Ｉ Ｃ Ａ Ｍ １ 总量,正常对照为（０．１７６４±０．０４３２）ｎｇ,牙周炎患者为（０．０８３０±０．０１９７）ｎｇ,二者之间有显著性差异（ Ｐ＜ ０．０１）⒚表明龈沟液ｓ Ｉ Ｃ Ａ Ｍ １ 含量的降低与牙周炎有关⒚     

高原肺水肿肺泡灌洗液中体免疫物质的含量变化及其意义

对８例高原肺水肿肺泡灌洗液听的免疫球蛋白，补体，组胺与５－羟色胺含量进行了检测，并与８例移居西藏高原５ｄ的健康成人对比，高原肺水肿患者的肺泡灌洗液中ＩｇＧ，ＩｇＭ，Ｃ３，Ｃ４与组胺含量均显著增高（Ｐ〈０．０１），并见Ｃ５，Ｃ９增高（Ｐ〈０．０５）。高原肺水肿的发生与体液免疫反应密切相关，高原肺水肿可能为超敏反Ⅲ型疾病的局部表现。     

乳清酸的单扫示波极谱研究

乳清酸在０．１ｍｏｌ／ＬＨＣｌＯ４＋０．０２ｍｏｌ／ＬＮａＣｌＯ４底液中，于ＪＰ－２型示波极谱仪上，有一良好的二阶导数峰Ｅｐ＝－０．８６０±０．０１Ｖ（ＳＣＥ），浓度在１×１０－７～６×１０－５ｍｏｌ／Ｌ范围内，与峰高成线性关系，检测限为７．５×１０－８ｍｏｌ／Ｌ．实验证明，电极过程为具有催化性质的双电子可逆过程．     

牙周病患者唾液中一氧化氮含量的研究

通过检测牙周病患者唾液亚硝酸盐的含量来代表一氧化氮的含量,对１５例牙龈炎患者、１７例牙周炎患者和２７例正常对照唾液一氧化氮的含量进行了检测．结果表明,正常对照唾液一氧化氮的含量为２８．８０６±６．６０４μｍｏｌ／Ｌ,男女间无显著性差异（Ｐ＞０．０５）,牙龈炎和牙周炎患者唾液一氧化氮的含量分别为３４．３６５±７．１４８μｍｏｌ／Ｌ、５６．２１４±１３．５３７μｍｏｌ／Ｌ,均明显高于正常对照（Ｐ＜０．０２,Ｐ＜０．０１）,牙周炎患者唾液一氧化氮的含量明显高于牙龈炎（Ｐ＜０．０１）．提示唾液一氧化氮含量的变化与牙周病有密切关系．     

头颈癌患者手术前后T细胞亚群的观察

对３０例头颈癌患者手术前后的Ｔ淋巴细胞亚群变化进行观察，结果表明：头颈患者的ＣＤ＋８较对照组明显升高（Ｐ＜０．０１），ＣＤ＋４／ＣＤ＋８值比健康人显著降低（Ｐ＜０．０１），且有随临床分期增加而ＣＤ＋８升高及ＣＤ＋４／ＣＤ＋８比值下降的趋势，Ⅰ－Ⅱ期与Ⅲ－Ⅳ期相比有显著性差异（Ｐ＜０．０１）；而手术后ＣＤ＋８逐渐下降，ＣＤ＋４／ＣＤ＋８值却较术前有明显回升，术前与术后比较有显著性差异（Ｐ＜０．０１）．说明头颈癌患者存在着明显的细胞免疫功能紊乱，并随病情的发展而加重；而彻底切除肿瘤是迅速恢复机体细胞免疫功能的有效手段．提示：Ｔ淋巴细胞亚群检测对头颈癌患者的病情发展、免疫功能评定及疗效观察具有一定参考价值     

茶多酚抗突变和消除自由基作用的研究

采用Ｅ．ＣｏｌｉＳＯＳ显色法，小鼠骨髓细胞微核及染色体畸变试验和体外自由基消除实验等方法测定了茶多酚复合物（ＴＰ）的抗突变和消除自由基作用．结果表明：（１）ＴＰ的终浓度在２．５和５ｍｇ／ｍｌ时，对由阳性致突变物ＭＮＮＧ，ＥＭＳ和ＮａＮ＿３诱导的ＳＯＳ应答反应均具有明显的抑制作用；（２）小鼠每日ｉｇ４０、８０和１２０ｍｇ／ｋｇ剂量的ＴＰ能明显抑制由环磷酰胺（ＣＰ）诱发的骨髓ＰＣＥ的ＭＮＣＦ，三种剂量ＴＰ的抑制率分别为４０．９８％、６６．７６％和６５．９４％；（３）ＴＰ对ＭＭＣ诱发的骨髓细胞染色体畸变（ＣＡ）的抑制率分别为６２．５６％、５５．７１％和４７．９５％；（４）在Ｘ／ＸＯ－ＥＳＲ、Ｘ／ＸＯ／Ｌｕｍｉｎｏｌ－ＢＣＬ和ＩＲ／ＮＢＴ－ＳＰＭ三种模型中ＴＰ对超氧阴离子Ｏ＿２自由基均具有极强的消除作用，消除率分别为９８±６％、９８±１．２％和９５±１．５％，对Ｏ＿２的消除效率明显强于维生素Ｃ和Ｅ，对不同工艺制备的ＴＰ消除活性氧自由基作用的测定结果显示：脱咖啡碱程度高，ＥＧＣ和Ｌ－ＥＧＣＧ含量比例高的ＴＰ－３制剂消除Ｏ＿２的效率最高．因此，ＴＰ消除有害自由基，中断或终止自由基的氧化反应是抗突变，抗肿瘤作用的主要机制     

β修正──丁基罗丹明B－OP新光度法测定工业废水中砷含量

在酸性溶液中，砷（Ａｓ￣（５＋））与丁基罗丹明Ｂ（ＢＲＢ）反应，显色液由红色变紫色，非离子表面活性剂ＯＰ能提高分析灵敏度并增大ＢＲＢ及其与砷络合产物溶解性。本文研究β修正光度法测定工业废水中痕量砷，它能消除过量ＢＲＢ的干扰提高分析灵敏度、精密度和准确度。结果表明砷浓度０～０．４０ｍｇ／Ｌ时，修正吸光度有良好线性关系，检出限０．００４ｍｇ／Ｌ，加标回收率９３．０％～１１１％，相对标准偏差ＲＳＤ≤６．５％。该方法适合于化工废水、城市污水及各种环境水质分析。     

短裙竹荪多糖清除O^—.2及对人工细胞膜自由基氧化的影响

短裙竹荪「Ｄｉｃｔｙｏｐｈｏｒａ ｄｕｐｌｉｃａｔａ（Ｂｏｓｅ）Ｆｉｓｈｅｒ」经热水抽提,乙醇沉淀,Ｓｅｖａｇ法去蛋白,乙醇分级分离,再经ＤＥＡＥ－纤维素柱层析得多糖组分ＰＳ。在体外产生Ｏ＾－．２的反应体系中,竹荪多糖组分ＰＳ在较低浓度下（〈２００ｍｇ／Ｌ）具有清除Ｏ＾－．２的作用,而在较高浓度下（〉２００ｍｇ／Ｌ）作用不明显。同时用荧光法研究了竹荪多糖组分ＰＳ对人红细胞膜脂质过氧化的影响,结果表     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

Low doses of a red wine ingredient figh diabetes in mice

Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Molecular motor assembly of a biomimetic system

Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence