检索结果-南通市图书馆

Large-scale information entropy analysis of important sites in mature and precursor miRNA sequences

science china(life sciences) 2009年第8期52卷 771-779页

作者： DU JiangFeng1,2,WU YongJun2,ZHANG YinXia3.WU Lei1,2,WANG XiaoLong3.TAO ShiHeng1,2 1 Bioinformatics Center,Northwest science and Technology university of Agriculture,Yangling 712100,china 2 {3. of life sciences,Northwest science and Technology university,Yangling 712100,china 3.{3. of science,Northwest science and Technology university,Yangling 712100,china Bioinformatics Center Northwest Science and Technology University of Agriculture Yangling 712100 China college of life sciences Northwest Science and Technology University Yangling 712100 China college of science Northwest Science and Technology University Yangling 712100 China

In order to find evidence of consistent sequence conservation or the base correlation degree in miRNA,some important sites in the sequences of reported miRNA and their precursors(pre-miRNA) were investigated via information entropy *** different groups of sites were obtained from special locations(head,tail) in miRNAs of different sources according to taxonomy(animal,plant and virus) and then analyzed by measuring the single base information redundancy(D1(L)) and the adjacent base related information redundancy(D2(L)).The results showed that D2(L) has more information than D1(L),though D1(L) changes roughly consistently with D2(L) in each *** pre-miRNAs are more conservative than those belonging to animals or *** addition,U is dominant in most sites compared with other *** was also found that in the middle of several groups,there were sites where miRNAs were cut down from pre-miRNAs by Enzyme Dicer which were significantly *** phenomenon shows that the conservatism is an aspect of the of miRNA and may be involved in the recognition and cutting by the *** results provided another perspective for understanding more about the primary structure of pre-miRNA.

关键词： miRNA conservative information entropy precursor evolution base correlation degree

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Photoresponsive organogel and organized nanostructures of cholesterol imide derivatives with azobenzene substituent groups

引用

Progress in Natural science:Materials International 2012年第1期22卷 64-70页

作者： Tifeng Jiao a,b,c,Yujin Wang a,Fengqing Gao a,Jingxin Zhou a,Faming Gao a a Hebei Key Laboratory of Applied Chemistry,college of Environmental and Chemical Engineering,Yanshan university,Qinhuangdao 066004,china b college of Chemistry & Materials Engineering,Wenzhou university,Wenzhou 3.5027,china c State Key Laboratory of Solid Lubrication,lanzhou Institute of Chemical Physics,Chinese Academy of sciences,lanzhou 730000,china [a] Hebei Key Laboratory of Applied Chemistry College of Environmental and Chemical Engineering Yanshan University Qinhuangdao 066004 China [b] college of Chemistry & Materials Engineering Wenzhou University Wenzhou 325027 China [c] State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

Two new cholesterol imide derivatives with azobenzene substituent groups have been *** compounds possess headgroups of hydrogen or methyl units,*** gelation test revealed that a subtle change in the headgroup of azobenzene segment produced a dramatic change in the gelation behavior of both *** compound with headgroups of hydrogen units only gelated N,N-Dimethylformamide(DMF),while the other compound with headgroups of methyl units cannot gelate any solvent tested *** DMF gel and solution of the gelator,the reversible photoisomerization transitions by irradiation with ultraviolet(UV) and visible light are investigated by UV-vis absorption spectra,Fourier transform infrared spectrometer,scanning electron microscope,atomic force microscope,and X-ray diffraction *** UV irradiation of the gel,trans-cis photoisomerization of the azobenzene groups occurs,the change in molecular polarity leads to the breaking of van der Waals interactions,resulting in the gel-sol *** gel can be recovered by the reverse cis-trans photoisomerization after exposure to visible *** and spectral studies reveal that the gelator molecules selfassemble into one-dimensional fibers,which further crossed-linked to form regular *** results afford useful information for the development of new versatile low molecular mass gelators and soft matter.

关键词： Organogel Cholesterol Azobenzene Photoisomerization Soft material

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Mathematic Expression of Kinetic Compensation Effect and Relationship between the Exothermic Decomposition Temperature and Critical Temperature of Thermal Explosion of Eighty-six Energetic Materials

引用

含能材料 2001年第1期9卷 8-9页

作者： HU Rong zu 1, YANG De suo 2, ZHANG Jiao qiang 3. (1. Department of Chemistry,Northwest university, Xi′an 710065, china 2. Department of Chemistry and Chemical Engineering, Baoji college of Arts and {3., Baoji 721007, china 3. Department of 西北大学陕西西安 710065 宝鸡文理学院陕西 721007 西北工业大学陕西西安 710072

Two relationships are established using the least squares method,between the kinetic parameters (the apparent activation energy and pre exponential constant),and the exothermic decomposition temperature and ther... 详细信息

关键词： critical temperature of thermal explosion decomposition temperature DSC energetic materials.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Two new Jurassic stoneflies (Insecta: Plecoptera) from Daohugou, Inner Mongolia, china

引用

Progress in Natural science:Materials International 2008年第8期18卷 1039-1042页

作者： Yushuang Liu, Dong Ren * college of life science, Capital Normal {3., 105 Xisanhuanbeilu, Haidian District, Beijing 10003., china college of life science Capital Normal University 105 Xisanhuanbeilu Haidian District Beijing 100037 China

Two new genera and two new species of family Taeniopterygidae, Mengitaenioptera multiramis gen. et sp. nov. and Noviramonemoura trinervis gen. et sp. nov. are described. These fossils were collected from Daohugou Village (the Middle Jurassic), Inner Mongolia, china. Hitherto, these fossil species from Daohugou are the oldest taeniopterygids. Both simple and complex venations simultaneously occurred in this group, which reveals that the early diversification of taeniopterids was well underway by the Middle Jurassic. Therefore, we prefer to adopt the Comstock’s opinion that the venation of taeniopterids was derived from the simple venation of the older group (such as Palaeonemouridae) at much ancient geological time ago. Some of the descendants carried this simple venation; others evolved into complex venation with many additional crossveins and branches.

关键词： Plecoptera Taeniopterygidae Daohugou Inner Mongolia Middle Jurassic

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Anticancer Drugs ( Ⅳ )——New Derivatives of Podophyllotoxin

引用

Chemical Research in Chinese Universities 1993年第2期9卷 116-120页

作者： TIAN Xuan, LI Jin-xin, ZHANG Ya-li CHEN Yao-zu (National Laboratory of Applied Organic Chemistry, lanzhou university, lanzhou, 730000)LI Wen-guang (Department of Pharmacology, lanzhou Medicine college, lanzhou, 730000)

Four new derivatives of podophyllotoxin, N'-podophyllic acid-N-[3.(2, 2, 5, 5-te-tramethyl-pyrrolinenyloxy)] semicarbazide(GP-11, 6), podophyllic acid [3.(2,2,5,5-te-tramethyl-pyrrolinenyloxy)]hydrazone (GP-12, 7), podophyllic acid-[4-(2, 2, 6, 6-tetramethyl-1-hydroxy piperidine)]hydrazone(GP-1-OH, 8) and podophyllic acid[4-(2,2, 6, 6-tetramethyl piperidine)]hydrazone(GP-1-H, 9) were synthesized. The inhibition effect of the four new compounds on L-1210 cells were determined. The antitumor activity and toxicity of GP-1(2), GP-1-OH(8), GP-1-H(9) and VP-16-213.1) were discussed.

关键词： Podophyllotoxin Anticancer drugs Nitroxyl radical

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mapping the Farming-pastoral Ecotones in china

引用

Journal of Mountain science 2009年第1期6卷 78-87页

作者： ZHANG Jian WEI Jie CHEN Quangon Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Tourism college Chongqing Normal University Chongqing 400047 China School of PastoralAgricultural science and Technology Lanzhou University Lanzhou 730020 China Graduate university of the Chinese Academy of sciences Beijing 100049 China

Conventional farming-pastoral ecotones methods of delineating were not quantitative and could not fully show their spatial distribution. The present paper attempts to develop quantitative methods for mapping farming-pastoral ecotones in china. Nine indicators, related to temperature, precipitation and altitude aspects, were selected to quantify ecological susceptibility of vegetation （crops and forage）. Methods of analytic hierarchy process （AHP） and expert score ranking combined with fuzzy set theory were applied to assign the weight for each indicator and to define the membership functions. The geographic information system （GIS） was used to manage the spatial database and conduct the spatial analysis. According to the spatial calculation of evaluation model integrated with GIS, the ecological susceptibility of vegetation （crops and forage） was mapped. Three different zones, pastoral area, farming-pastoral ecotones and farming area, were classified by spatial cluster analysis and the maximum likelihood classification for the numeric map of vegetation ecological susceptibility by GIS. This map was validated by the economic statistical result based on the ratio of the output value from animal husbandry in total output value of agriculture by the National Bureau of Statistics in china, indicating that the mapping of the farming-pastoral ecotones may be accepted.

关键词： AHP Farming-pastoral ecotone Fuzzyset theory GIS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Recognition of Glycolate Oxidase Apoprotein with Flavin Analogs in Higher Plants

引用

Acta Biochimica et Biophysica Sinica 2004年第4期36卷 290-296页

作者： Wei-Jun WANG*, Jing-Quan HUANG, Chong YANG, Jiu-Jiu HUANG, and Ming-Qi LI college of life science, South{3. Agricultural university, Guangzhou 510642,{3. college of life science South China Agricultural UniversityGuangzhou 510642 China

The dependence of glycolate oxidase apoprotein (apoGO) activity on flavin analogs was surveyed in 9 higher plants from 7 families. Activities of all apoGOs depended not only on flavin mono- nucleotide (FMN) but also on flavin adenine dinucleotide (FAD), but not on riboflavin. The kinetic analysis showed that FMN was the optimum cofactor for apoGO from leaves of Brassica campestris. In plant kingdom, FMN, FAD and riboflavin are three flavin analogs with very similar structure, and they could coexist and be inter-converted from each other, so the question is how the apoprotein of glycolate oxidase (GO) recognized these flavin analogs. No inhibition effect of riboflavin on the activity of apoGO with FMN or FAD was found and no obvious quenching of riboflavin or apoGO protein fluorescence was detected with the addition of apoGO or riboflavin, respectively. These results indicated that riboflavin did not bind to apoGO tightly like FMN and FAD. Inorganic phosphate (Pi) did inhibit the activity of GO, and kinetic analysis revealed that this inhibition was caused by the competitive binding to apoGO between Pi and FMN. This competitive binding was further confirmed by the inhibition of Pi to the quenching of FMN and apoGO protein fluorescence with apoGO and FMN, respectively. It was suggested that the 5’-phosphate group of FMN or FAD may play a key role in the recognition and binding of riboflavin analog cofactors with apoGO.

关键词： glycolate oxidase in higher plant flavin analogs 5’-phosphate moiety recognition

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Protein trans-splicing based dual-vector delivery of the coagulation factor Ⅷ gene

引用

中国科学：生命科学英文版 2010年第6期53卷 683-689页

作者： ZHU FuXiang,LIU ZeLong,CHI XiaoYan & QU HuiGe life science college of Ludong {3.,Yantai 264025,china 1. life science college of Ludong {3. Yantai 264025 China

A dual-vector system was explored for the delivery of the coagulation factor VIII gene,using intein-mediated protein trans-splicing as a means to produce intact functional factor VIII post-translationally.A pair of eukaryotic expression vectors,expressing Ssp DnaB intein-fused heavy and light chain genes of B-domain deleted factor VIII (BDD-FVIII),was *** transient co-transfection of the two vectors into 293.and COS-7 cells,the culture supernatants contained (13.±23. and (109±22) ng mL–1 spliced BDD-FVIII antigen with an activity of (1.05±0.16) and (0.79±0.23. IU mL–1 for 293.and COS-7 cells,*** spliced BDD-FVIII was also detected in supernatants from a mixture of cells transfected with inteinfused heavy and light chain *** spliced BDD-FVIII protein bands from cell lysates were visualized by Western *** data demonstrated that intein could be used to transfer the split factor VIII gene and provided valuable information on factor VIII gene delivery by dual-adeno-associated virus in hemophilia A gene therapy.

关键词： intein protein trans-splicing coagulation factor VIII dual-vector gene delivery

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cu(Ⅱ) Potentiation of Alzheimer Aβ1-40 Cytotoxicity and Transition on its Secondary Structure

引用

Acta Biochimica et Biophysica Sinica 2006年第11期38卷 765-772页

作者： Xue-Ling DAI~1 Ya-Xuan SUN~2 Zhao-Feng JIANG~2* 1 college of life science,Capital Normal {3.,Beijing 10003.,china 2 college of Applied sciences and Humanities,Beijing Union {3.,Beijing 100083.china college of life science Capital Normal UniversityBeijing 100037 China college of Applied sciences and Humanities Beijing Union UniversityBeijing 100083 China

Mounting evidence has shown that dyshomeostasis of the redox-active biometals such as Cuand Fe can lead to oxidative stress,which plays a key role in the neuropathology of Alzheimer's disease（AD）.Here we demonstrate that with the formation of Cu（Ⅱ）·Aβ1-40 complexes,copper markedly potentiatesthe neurotoxicity exhibited by β-amyloid peptide （Aβ）.A greater amount of hydrogen peroxide was releasedwhen Cu（Ⅱ）·Aβ1-40 complexes was added to the xanthine oxidase/xanthine system detected by potassiumiodide *** bound to Aβ1-40 was observed by electron paramagnetic resonance（EPR） *** dichroism （CD） studies indicated that copper chelation could cause a structuraltransition of Aβ.The addition of copper to Aβ introduced an increase on β-sheet as well as α-helix,whichmay be responsible for the aggregation of Aβ.We hypothesized that Aβ aggregation induced by copper maybe responsible for local injury in *** interaction between Cu2+and Aβ also provides a possible mechanismfor the enrichment of metal ions in amyloid plaques in the AD brain.

关键词： Alzheimer’s disease Cu(Ⅱ)·Aβ1-40 complex neuron injury Aβ secondary structure

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Bionic Design and Finite Element Analysis of Elbow in Ice Transportation Cooling System

引用

Journal of Bionic Engineering 2010年第3期7卷 301-306页

作者： Dejun Miao~(1,2), Xiuhua Sui~3. Linjing Xiao~3.1. Key Laboratory of Mine Hazard Prevention and Control (Ministry of Education, china), Shandong university of science and Technology, Qingdao 266510, P. R. china 2. School of Architecture, Tsinghua university, Beijing 100084, P. R. china 3. college of Mechanical and Electronic Engineering, Shandong university of science and Technology, Qingdao 266510, P. R. china [a] Key Laboratory of Mine Hazard Prevention Control (Ministry of Education China) Shandong University of Science Technology Qingdao 266510 P. R. China [b] School of Architecture Tsinghua University Beijing 100084 P. R. China [c] College of Mechanical Electronic Engineering Shandong University of Science Technology Qingdao 266510 P. R. China

With the increase in mining depth, mine heat harm has appeared to be more prominent. The mine heat harm could be resolvedor reduced by ice refrigeration. Thus, ice transportation through pipeline becomes a critical problem; typically flowresistance occurs in the elbow. In the present study, according to the analysis of the surface morphology of fish scale, abiomimetic functional surface structure for the interior wall of elbow is designed. Based on the theory of liquid-solid two phaseflow, a CFD numerical simulation of ice-water mixture flowing through the elbow is carried out using finite element *** experiments of pressure drop and flow resistance for both bionic and common elbows are conducted to test theeffect of the bionic elbow on flow resistance reduction. It is found that with the increase in the ice mass fraction in the ice-watermixture, the effect of bionic elbow on resistance reduction becomes more obvious.

关键词： bionic elbow two phase flow ice transportation flow resistance reduction pressure loss

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：