Identification of protein superfamily from structurebased sequence motif

The structure-based sequence motif of the distant proteins in evolution, protein tyrosine phosphatases (PTP) Ⅰ and Ⅱ superfamilies, as an example, has been defined by the structural comparison, structure-based sequence alignment and analyses on substitution patterns of residues in common sequence conserved regions. And the phosphatases Ⅰ and Ⅱ can be correctly identified together by the structure-based PTP sequence motif from SWISS-PROT and TrEBML databases. The results show that the correct rates of identification are over 98%. This is the first time to identify PTP Ⅰ and Ⅱ together by this motif.     

佛经文学与六朝小说三生缘母题

三生生命观是佛教对有情众生的生命演化进行的全新解释，它把人的生命流转分为前世、今生、来世三段，这种有别于中土一世生命说的观点，经过汉译佛经的传布，以其新奇性和合乎生活经验的解释深深地吸引了六朝中土文人，六朝小说对三生缘母题的演绎就是这一影响下的直接成果。三生缘母题在中土后世小说中多有演化。     

人类基因组中L1元件及其5＇UTR的研究

讨论了L1在人类染色体中的分布密度与染色体长度以及L1的密度与基因密度之间的关系．发现在大多数染色体上L1的密度和染色体的长度表现为正相关，而L1的密度和染色体中基因的密度表现为负相关；对人类L1的5’UTR进行了详细的研究后，发现在L1元件的5’UTR部分含有许多转录因子结合位点．对基因的转录起始位点上游进行统计分析，发现其中含有大量的L1序列．通过对人类的EST数据库进行BLAST分析，新发现了51条和人类L15’UTR相似性较高的EST片断，根据它们分布的组织特异性，说明L1元件可能调控与发育过程有关的基因的表达；最后应用多样性增量的方法对人类和大鼠的L1 5＇UTR进行了区分，得到了较好的预测结果，说明大部分L1的5’UTR的调控作用是人类特有的．     

人类基因组中L1元件及其5′UTR的研究

讨论了L1在人类染色体中的分布密度与染色体长度以及L1的密度与基因密度之间的关系.发现在大多数染色体上L1的密度和染色体的长度表现为正相关,而L1的密度和染色体中基因的密度表现为负相关;对人类L1的5′UTR进行了详细的研究后,发现在L1元件的5′UTR部分含有许多转录因子结合位点.对基因的转录起始位点上游进行统计分析,发现其中含有大量的L1序列.通过对人类的EST数据库进行BLAST分析,新发现了51条和人类L1 5′UTR相似性较高的EST片断,根据它们分布的组织特异性,说明L1元件可能调控与发育过程有关的基因的表达;最后应用多样性增量的方法对人类和大鼠的L1 5′UTR进行了区分,得到了较好的预测结果,说明大部分L1的5′UTR的调控作用是人类特有的.     

A biomimetic approach to the synthesis of a mycolic acid motif

A new method for the stereoselective synthesis of the (R,R)-β-hydroxy-α-alkyl fatty acid fragment of mycolic acids, via an asymmetric anti-aldol reaction is reported. The ‘mycolic acid motif’ fragment was prepared in three steps and >98% ee.     

Binary self-assembly of highly symmetric DNA nanocages via sticky-end engineering

Discrete and symmetric three-dimensional(3D)DNA nanocages have been revoked as excellent candidates for various applications,such as guest component encapsulation and organization(e.g.dye molecules,proteins,inorganic nanoparticles,etc.)to construct new materials and devices.To date,a large variety of DNA nanocages has been synthesized through assembling small individual DNA motifs into predesigned structures in a bottom-up fashion.Most of them rely on the assembly using multiple copies of single type of motifs and a few sophisticated nanostructures have been engineered by co-assembling multi-types of DNA tiles simultaneously.However,the availability of complex DNA nanocages is still limited.Herein,we demonstrate that highly symmetric DNA nanocages consisted of binary DNA point-star motifs can be easily assembled by deliberately engineering the sticky-end interaction between the component building blocks.As such,DNA nanocages with new geometries,including elongated tetrahedron(E-TET),rhombic dodecahedron(R-DOD),and rhombic triacontahedron(R-TRI)are successfully synthesized.Moreover,their design principle,assembly process,and structural features are revealed by polyacryalmide gel electrophoresis(PAGE),atomic force microscope(AFM)imaging,and cryogenic transmission electron microscope imaging(cryo-TEM)associated with single particle reconstruction.     

论网络穿越小说的基本特性

网络穿越小说是"穿越时空"文学母题在网络媒体时代的文本演绎形式。本文从分析"穿越时空"文学母题的特性和网络媒体的特性入手,分析了网络穿越小说的文学母题特性和网络艺术特性,进而分析了网络穿越小说的时空特质,结论表明:网络穿越小说在文学意义上是一种全新的小说艺术形式,在美学意义上则在最大程度上实现了人在数字化环境中的虚拟性存在。     

A sensitive, rapid ferricyanide-mediated toxicity bioassay developed using Escherichia coli

A need for rapid toxicity techniques has seen recent research into developing new microbiological assays and characterising their toxicity responses using a range of substances. A microbiological bioassay that determines changes in ferricyanide-mediated respiration for toxicity measurement (FM-TOX) shows particular promise. The development and optimisation of an improved FM-TOX method, incorporating novel features, is described using Escherichia coli as the biocatalyst. Omission of an exogenous carbon source, used in previously described FM-TOX assays, substantially improves the assay sensitivity. In addition, the development of a two-step procedure (toxicant exposure followed by determination of microbial respiratory activity) was found to enhance the inhibition of E. coli by 3,5-dichlorophenol and four other toxicants, compared to single-step procedures. Other assay parameters, such as the ferricyanide concentration, exposure times and optical density of the biocatalyst were also optimised, sometimes based on practical aspects. Toxicity tests were carried out using the adopted technique on both organic and inorganic toxicants, with classic sigmoid-shaped dose-response curves observed, as well as some non-standard responses. IC₅₀ data is presented for a number of common toxicants. The optimised assay provides a good foundation for further toxicity testing using E. coli, as well as the potential for expanding the technique to utilise other bacteria with complementary toxicity responses, thereby allowing use of the assay in a range of applications.     

RNA结合蛋白与人类男性不育

本文概括了控制精子正常产生的诸多候选基因在染色体上的定位、演化及其编码的 RNA 结合蛋白与人类男性精子发生之间关系研究方面的最新进展,为人类男性不育症的治疗和计划生育的顺利推行奠定了坚实的理论基础并展示出光明的前景。     

清代龙袍上龙纹眉眼的演变和辨识

龙纹是龙袍上最受关注的纹样,清代龙袍上的龙纹特征明显,容易识别,而且其细节的演变过程呈现一定的规律性.这里分析了清代各个时期龙袍上龙纹眉眼的时代特征,以作为龙袍和龙纹断代的一个指标.