中华绒螯蟹卵巢RACE Cdna文库的构建

应用抑制性差减杂交技术 ,已经获得了中华绒螯蟹卵巢发育过程中差异表达基因的部分cDNA序列。为了进一步获得基因的全长cDNA序列 ,运用SMART技术 ,成功构建了中华绒螯蟹卵巢 (Ⅲ期 )RACEcDNA文库。琼脂糖凝胶电泳结果表明 ,文库所含全长cDNA的长度主要集中在 5 0 0～ 2 0 0 0bp之间 ,RACEPCR结果表明 ,所用基因特异性引物与接头引物皆能扩增出产物 ,说明所构文库的质量较好 ,适于用RACE方法从中分离中华绒螯蟹卵巢发育相关基因的全长cDNA。     

A Simple Novel Agar Diffusion Method for Isolation of Indigenous Microalgae Chlamydomonas sp. CRP7 and Chlorella sp. CB4 from Operational Swampy Top Soil

A simple agar diffusion method is developed where pure colony of Chlamydomonas sp. CRP7 was isolated from Chlorella sp. CB4 mixtures by passing through agar migration with a light exposure of 6,000 lux for 7 h. The main concept behind it is that Chlamydomonas has flagella and the rhodopsin pigment is attracted towards light. Thus the above two microalgae species can be separated from the mixtures as eye spot serves as a navigator and flagella serves as a propeller for Chlamydomonas spp. Further the genomic DNA was isolated and purified from the above mentioned two species after the separation from the mixtures. PCR amplification was carried out for ITS1, 5.8S and ITS2 regions. The amplified products were sequenced and the sequence analysis confirmed that they belong to Chlamydomonas sp. and Chlorella sp. This is an important augmentation for isolation and separation of microalgae.     

NADH荧光法快速检测细菌总数

基于细菌胞内NADH的荧光特性及其在胞内含量稳定的特性, 建立一种快速检测细菌总数的新方法。该荧光法的NADH检测限为1 nmol/L, NADH含量在10 nmol/L~0.2 mmol/L间与荧光强度呈良好线性关系(R2 =0.9905)。经离心获得菌体细胞, 热Tris-HCl法提取胞内NADH, 以 342 nm为激发波长, 461 nm为发射波长测定提取液荧光强度, 1 h内可检测到样品1×104 CFU/mL菌数。结果表明该方法快速、灵敏、简便、重复性好, 可适用于食品卫生与安全、环境检测等领域活细菌数量的定量检测。     

Asymmetric synthesis of the four diastereoisomers of a novel non-steroidal farnesoid X receptor (FXR) agonist: Role of the chirality on the biological activity

An asymmetric synthetic strategy was designed for the preparation of the four possible diastereoisomers of 3,6-dimethyl-1-(2-methylphenyl)-4-(4-phenoxyphenyl)-4,8-dihydro-1H-pyrazolo[3,4-e][1,4]thiazepin-7-one, a non-steroidal FXR agonist, we recently discovered following a virtual screening approach. The results obtained from an AlphaScreen assay clearly demonstrated that only the isomer endowed with 4R,6S absolute configuration is responsible for the biological activity. A deep investigation of the different putative binding modes adopted by these enantiomerically pure ligands using computational modeling studies confirmed the enantioselectivity of FXR towards this class of molecules.     

Kinetic Monte Carlo simulation for the striation distribution of void defects in Czochralski silicon growth

Unique crystal-originated pit (COP) distribution, similar to a striation pattern, is well matched with the oxygen profile in experimental analysis. It shows the strong relationship between oxygen concentration and COP distribution. In this paper, we study the generation of void defects and the relationship between interstitial oxygen and vacancy using the kinetic lattice Monte Carlo (KLMC) method. The KLMC method has been applied extensively in various forms to the study of micro-defects in silicon wafers. It explained well the formation of void defects such as vacancy–oxygen complex and vacancy–vacancy complex. The formation of clusters is strongly affected by oxygen concentration, which showed the relationship between COP distribution and oxygen concentration. The unique COP distribution could be correctly explained with KLMC results, and this kind of meso-scale results has not yet been reported.     

StructureSelector: A web‐based software to select and visualize the optimal number of clusters using multiple methods

Inferences of population genetic structure are of great importance to the fields of ecology and evolutionary biology. The program structure has been widely used to infer population genetic structure. However, previous studies demonstrated that uneven sampling often leads to wrong inferences on hierarchical structure. The most widely used ΔK method tends to identify the uppermost hierarchy of population structure. Recently, four alternative statistics (medmedk , medmeak , maxmedk and maxmeak ) were proposed, which appear to be more accurate than the previously used methods for both even and uneven sampling data. However, the lack of easy‐to‐use software limits the use of these appealing new estimators. Here, we developed a web‐based user‐friendly software structureselector to calculate the four appealing alternative statistics together with the commonly used Ln Pr(X|K) and ΔK statistics. structureselector accepts the result files of structure , admixture or faststructure as input files. It reports the “best” K for each estimator, and the results are available as HTML or tab separated tables. The program can also generate graphical representations for specific K, which can be easily downloaded from the server. The software is freely available at http://lmme.qdio.ac.cn/StructureSelector/ .     

Anti-oxidation activity of ethanol extracts from natural thalli of lichens

Screening test on anti-oxidation activity using 1,1-diphenyl-2-picrylhydrazyl(DPPH) was performed for 99 ethanol extracts of 85 species of natural thalli of lichens in order to find novel anti-oxidation compounds.The 17 extracts of natural thalli showed high anti-oxidation activity.Among them,the activities of extracts from Hypogymnia vittata,Peltigera aphthosa,Nephromopsis ornata,Pseudevernia furfuracea,Cladonia vulcani and Peltigera elizabethae were higher.Extracts of Peltigera spp.showed higher activity than those of other genera.The ethanol extract of P.aphthosa had been separated into ethyl acetate-soluble and water-soluble fractions.Two anti-oxidative spots were found only in the water-soluble fractions by thin-layer chromatography.The compound in the lower spot had the same Rf value,UV spectrum,and color as authentic solorinine that was previously found as a unique quaternary ammonium compound from Peltigera spp.We now report that the hydrophilic lichen substance,solorinine showed a nearly same anti-oxidation activity(EC50=120?mol/Lol/L) as standard antioxidant Trolox(EC50=150?mol/L).     

家蚕神经肽基因的筛查及成熟肽的预测

神经肽（neuropeptide）是家蚕Bombyx mori体内重要的调控物质。为了充分理解神经肽对家蚕发育的调控, 扩充家蚕神经肽的数量, 本研究利用BLAST的tblastn程序结合OpenOffice软件的查找程序, 基于其他昆虫和无脊椎动物神经肽的同源性和保守的结构特点, 在家蚕基因、理论蛋白质数据库及NCBI中进行全面而系统的基因筛查; 并利用各种在线工具对所筛查到基因和理论蛋白质的结构和成熟肽进行预测分析。结果共获得allatostatin-A （AST-A）, allatostatin-B （AST-B）, allatostatin-C （AST-C）, allatropin (AT), ecdysis-triggering hormone （ETH）, crustacean cardioactive peptide (CCAP)和FMRFamide等31个神经肽基因家族, 包括37个神经肽基因亚家族, 共计44个神经肽基因; 预测出193个成熟的神经肽, 其中73个根据家族同源性预测在C末端发生酰胺化, 而6个被预测在N末端发生了环化, 9个被预测酪氨酸发生了硫酸化。大部分成熟神经肽都具有明显的家族结构特征, 但proctolin, CCAP及CAPA-PK成熟肽结构上与其他昆虫相比有所扩展。结果提示, 家蚕神经和内分泌细胞产生了几乎在所有昆虫中具有的神经肽前体; 进化过程中大部分成熟神经肽的氨基酸序列在种间产生了差异, 但家族特征性基序高度保守。本研究为神经肽功能研究以及神经肽对家蚕发育尤其是蛹期发育调控的研究奠定了基础。