Selection and amplification of hosts from dynamic combinatorial libraries of macrocyclic disulfides

We have discovered two receptors for two different guests from a single dynamic combinatorial library. Each of the two guests amplifies the formation of a tightly binding host at the expense of unfit library members. Small differences in host-guest binding translate into useful differences in amplification. The selected hosts could be readily synthesized using biased dynamic libraries that contain only the right ratio of those building blocks that were selected by the guests. These results establish dynamic combinatorial chemistry as a practical method not only for the discovery but also for the synthesis of new receptors.     

Multiple catenanes derived from calix[4]arenes

A multicatenane is described in which two belts consisting of four annelated rings attached to the wide rims of two calix[4]arenes are interwoven in such a way that each ring of one belt penetrates two adjacent rings of the other belt and vice versa. The key step of the synthesis of this [8]catenane is the exclusive formation of preorganized heterodimers between a multimacrocyclic tetraurea calix[4]arene and an "open-chain" tetraurea calix[4]arene containing eight omega-alkenyl groups. When a tetraurea calix[4]arene containing four alkenyl groups is used, a bis-[3]catenane is formed analogously.     

医院图书馆与社区互动的启示

医院图书馆已成为社区居民获取医学信息资源的重要渠道。在介绍医院图书馆为社区服务现状的基础上,从建立社区卫生服务的信息支持系统、拓宽社区医疗服务职能以及增强馆藏资源的文化功能3个方面,深入阐述了新时期医院图书馆与社区互动带给医务工作者的启示。     

Identification of a blue photoluminescent composite material from a combinatorial library

A quaternary combinatorial masking strategy was used in conjunction with photolithography to generate compositionally diverse thin-film phosphor libraries containing 1024 different compositions on substrates 2.5 centimeters square. A parallel imaging system and scanning spectrophotometer were used to identify and characterize compositions in the library with interesting luminescent behavior. Optimal compositions were identified with the use of gradient libraries, in which the stoichiometry of a material was varied continuously. This process led to the identification of an efficient blue photoluminescent composite material, Gd3Ga5O12/SiO2. Experimental evidence suggests that luminescence in this material may arise from interfacial effects between SiO2 and Gd3Ga5O12.     

中国飞蝗线粒体COI基因片段的扩增

对中国飞蝗各亚种线粒体DNA的COI基因片段进行了扩增并测序。结果表明,扩增产物为单一带,大小约为1.3kb。对此扩增产物序列分析证明所扩增的COI基因序列是一个含混不清的序列,说明在中国飞蝗不同亚种的基因组DNA中存在线粒体的假基因序列,因此以飞蝗基因组DNA为模板PCR扩出的mtDNA COI基因片段不适宜用作分析飞蝗种群遗传和系统发育的分子标记。     

香蒲拟发网菌12S rDNA的PCR扩增及序列分析

采用CTAB法对基物培养获得的香蒲拟发网菌（Stemonitopsis typhina（Wiggers））进行总DNA提取,并用引物对其12S rDNA片段进行扩增,扩增产物序列长度为376 bp,探讨了香蒲拟发网菌的分子系统学关系.     

魔芋DNA快速提取新方法及ISSR-PCR扩增

[目的]研究魔芋DNA的提取方法。[方法]采用CTAB、SDS及新改良的方法提取魔芋总DNA,通过分光光度计检测、电泳检测及ISSR-PCR检测方法进行比较分析。[结果]采用新改良的方法得到的DNA纯度及产量均较高,适于魔芋DNA的快速提取;以其为模板进行ISSR-PCR扩增,条带清晰,可获得较好的结果。[结论]为大规模提取高质量的魔芋DNA奠定基础,也为进一步研究魔芋的遗传多样性提供了分子依据。     

魔芋DNA快速提取新方法及ISSR-PCR扩增（摘要）

[目的]研究魔芋DNA的提取方法。[方法]采用CTAB、SDS及新改良的方法提取魔芋总DNA,通过分光光度计检测、电泳检测及ISSR-PCR检测方法进行比较分析。[结果]采用新改良的方法得到的DNA纯度及产量均较高,适于魔芋DNA的快速提取;以其为模板进行ISSR-PCR扩增,条带清晰,可获得较好的结果。新改良的方法与常规的SDS及CTAB方法相比,有以下优点：①效率高。运用冷冻研磨仪进行研磨,克服了研磨困难问题,节约液氮,且研磨效率大大提高,研磨时间短,褐变较少,1个人即可同时大批量进行提取;②提取质量高。在提取液中加入高浓度的PVP、β-巯基乙醇及KAc,有效去除了多酚和多糖等次生物质,检测结果DNA条带清晰,且无拖尾,更有利于大规模样本DNA提取;③用材少。需要的魔芋组织量少,适宜对较为珍贵的材料进行DNA提取,从而进行分子标记辅助育种、群体遗传多样性分析和种芋纯度鉴定的研究。[结论]为大规模提取高质量的魔芋DNA奠定基础,也为进一步研究魔芋的遗传多样性提供了分子依据。     

Amplification and molecular cloning of HTLV-I sequences from DNA of multiple sclerosis patients

Techniques of gene amplification, molecular cloning, and sequence analysis were used to test for the presence of sequences related to human T-lymphotropic virus type I (HTLV-I) in peripheral blood mononuclear cells of six patients with multiple sclerosis (MS) and 20 normal individuals. HTLV-I sequences were detected in all six MS patients and in one individual from the control group by DNA blot analysis and molecular cloning of amplified DNAs. The viral sequence in MS patients were associated with adherent cell populations consisting predominantly of monocytes and macrophages. Molecular cloning and nucleotide sequence analysis indicated that these amplified viral sequences were related to the HTLV-I proviral genome.     

盐芥ThNHX1基因的3’RACE

以盐芥为材料，依据拟南芥AtNHX1基因的序列信息设计引物，扩增出盐芥中ThNHX1基因的部分序列，然后使用快速扩增cDNA3’末端（3’RACE）方法，从盐芥中克隆到ThNHX13’cDNA序列。该序列全长680bp，编码104个氨基酸，其编码序列、氨基酸序列与拟南芥AtNHX1基因的相应序列同源性分别为91％和91．5％，而盐芥ThNHX1基因3’端非翻译区序列与拟南芥相应序列的同源性为68．5％，明显低于编码区。     

高校图书馆美学浅议

以广东海洋大学图书馆为例,对高校图书馆美学进行了阐述,指出高校图书馆只有将外在美与内在美结合起来,才能促进高校图书馆的发展。

     

试论学习型图书馆的创建

阐述了学习型图书馆创建的理论基础，分析了当前国内创建学习型图书馆的障碍所在，并就如何创建学习型图书馆提出了自己的意见。

     

中国被毛孢有性发育启动前后cDNA文库的构建

构建了中国被毛孢有性发育启动前后的cDNA文库。采用Total RNA Kit Ⅰ法提取总RNA,磁珠法分离mRNA,反转录合成双链cDNA。获得的cDNA经蛋白酶K与SfiⅠ消化酶切并纯化,连接到载体pUC19上,采用电转化法将其转化到感受态细胞DH-5α中。之后测定文库的克隆数、重组率、插入片段大小。结果显示,文库1含1.09×10⁶个重组体,蓝白斑实验显示重组率为92.5%;文库2含1.13×10⁶个重组体,蓝白斑实验显示重组率为92%;两文库重组DNA片段的大小范围均在500~2 000 bp。说明本试验中所提取的 RNA 其纯度很好,完全可以达到后续研究的要求。     

Optimization of ITS rDNA Amplification for Fungi from Black Soil in North China

In order to optimize polymerase chain reaction(PCR) amplification of the internal transcribed spacer(ITS) rDNA region from fungi found in black soil in North China,an orthogonal experimental design [L16(45)] was used to evaluate five factors(template,Mg2+,dNTP,Taq DNA polymerase,and primer) from four levels.Subsequently,the optimal annealing temperature,annealing time,extension time and cycle numbers were evaluated.The results showed that the optimized PCR solution for amplification of ITS region comprised ...     

稻田土壤DNA的提取及nifA基因的PCR扩增

为弄清茅贡米土壤微生物群落结构和生物固氮等代谢活动机制,采用试剂盒、SDS高盐和土壤预处理+SDS高盐3种土壤DNA提取方法,以从贵州茅贡米基地采集的土样提取的宏基因组DNA为模板,进行nifA基因的PCR扩增,比较了3种土壤DNA提取方法的效果.结果表明,试剂盒提取的DNA扩增到约200 bp和900 bp的nifA...     

盐芥ThNHX1基因的3′RACE

以盐芥为材料,依据拟南芥AtNHX1基因的序列信息设计引物,扩增出盐芥中ThNHX1基因的部分序列,然后使用快速扩增cDNA3′末端(3′RACE)方法,从盐芥中克隆到ThNHX13′cDNA序列。该序列全长680 bp,编码104个氨基酸,其编码序列、氨基酸序列与拟南芥AtNHX1基因的相应序列同源性分别为91%和91.5%,而盐芥ThNHX1基因3′端非翻译区序列与拟南芥相应序列的同源性为68.5%,明显低于编码区。     

论医学图书馆的发展模式

阐述了传统图书馆和数字图书馆的发展轨迹,详细分析了传统医学图书馆和数字医学图书馆各自的优缺点,指出医学图书馆未来的发展方向是传统图书馆和数字图书馆高度融合的复合型图书馆。     

试论医院图书馆的知识管理

为了深化图书馆的管理，适应知识经济时代读者的需求,综合国内各专家对知识管理的论述，结合医院图书馆的现状，指出了医院图书馆医院图书馆实施知识管理的重要性，并提出了实现知识管理的途径。

     

现代化图书馆服务模式的研究

通过对现代化图书馆的发展方向的判断，提出只有从创新图书馆服务模式和理念出发，并结合传统图书馆服务方式的精髓，从开展知识服务、远程教育、创建读书社和培养学科馆员等几方面拓展图书馆服务领域，深化服务层次，才能把握未来的图书馆发展方向。

     

借鉴国外经验 加快图书馆数字化建设

将图书馆馆藏文献实施数字化处理是实现数字化图书馆的一项重要内容，本文就这个问题进行了探讨。文章简要介绍了美国国会图书馆、日本国会图书馆国、荷兰皇家图书馆等国家图书馆实施馆藏文献数字化的方法、技术、内容等几个方面的情况，并就本单位图书馆实施馆藏文献数字化工作提出几点看法。