线粒体蛋白转运系统的序列相似性分析

通过在27个不同进化层次物种的基因组和蛋白组中搜索酵母线粒体蛋白转运系统亚基的同源序列, 并进一步分析了同源亚基序列相似性与其所在线粒体位置的关系. 结果表明, 位于线粒体相同位置的模块有类似的序列相似性曲线, 相似性曲线在模块内部一般有波峰和波谷. 从线粒体外膜到基质, 序列相似性整体升高. 线粒体蛋白转运系统亚基与一些功能不相关的蛋白也表现出序列相似关系, 且这些亚基多集中在线粒体的内膜和外膜.     

酿酒酵母线粒体蛋白转运系统在立克次体中的同源分析

进化分析表明,与线粒体亲缘关系最近的原核生物是立克次体(Rickettsia prowazekii).搜索酿酒酵母(Saccharom ycescerevisia)线粒体蛋白转运系统的35个亚基在立克次体中的同源蛋白质,仅发现了5个同源蛋白,且它们只属于转运系统在线粒体外膜和基质上的模块,没有发现转运系统在膜间隙和内膜...     

扬子鳃蛭线粒体基因组全序列测定及其系统学地位——基于Pacbio和Illumina技术

利用Illumina和Pacbio测序技术对扬子鳃蛭（Ozobranchus jantseanus）线粒体基因组全序列进行测序及注释，并与NCBI数据库中蛭纲（Hirudinea）其他物种的线粒体全序列的排列方式和系统进化关系进行了比较，以确定其系统学地位.结果显示：获得的线粒体基因组序列长度为14 868 bp，蛋白编码基因存在2种起始密码子，分别为ATG和ATT；终止密码子共有4种，分别为TAA，TAG，TA和T；蛭纲10个物种的线粒体基因组全序列基因排序可分为2种类型，其差异表现在tRNAs的互换和长非编码区的长度的不同；扬子鳃蛭所属的吻蛭目（Rhynchobdellida）均为b型，绝大部分无吻蛭目（Arhynchobdellida）的排列方式为a型.基于蛭纲物种的13个蛋白编码基因(PCGs)的Neighbor-Joining（NJ）树进化分析显示，扬子鳃蛭与其他吻蛭目物种聚类.     

扬子鳃蛭线粒体基因组全序列测定及其系统学地位——基于Pacbio和Illumina技术

利用Illumina和Pacbio测序技术对扬子鳃蛭（Ozobranchus jantseanus）线粒体基因组全序列进行测序及注释，并与NCBI数据库中蛭纲（Hirudinea）其他物种的线粒体全序列的排列方式和系统进化关系进行了比较，以确定其系统学地位.结果显示：获得的线粒体基因组序列长度为14 868 bp，蛋白编码基因存在2种起始密码子，分别为ATG和ATT；终止密码子共有4种，分别为TAA，TAG，TA和T；蛭纲10个物种的线粒体基因组全序列基因排序可分为2种类型，其差异表现在tRNAs的互换和长非编码区的长度的不同；扬子鳃蛭所属的吻蛭目（Rhynchobdellida）均为b型，绝大部分无吻蛭目（Arhynchobdellida）的排列方式为a型.基于蛭纲物种的13个蛋白编码基因(PCGs)的Neighbor-Joining（NJ）树进化分析显示，扬子鳃蛭与其他吻蛭目物种聚类.     

基于相对熵原理构建生物进化系统树

根据相对熵原理定义了物种进化距离,把它应用到基于DNA序列分析的生物进化系统树构建的研究中.首先选用64种脊椎动物的线粒体DNA序列为材料,得到与传统的根据物种形态构建的系统树基本一致的树形;进而进行全基因组序列层次的物种进化的研究,选取长度约为线粒体DNA序列102倍的12种古生菌、真细菌全序列,最终也得到了合理的系统树.     

miR-430基因簇的生物信息学分析

很多microRNA （miRNA）基因在基因组上紧密排列形成miRNA基因簇,mir-430是目前已发现的最大miR-NA基因簇,但其起源和进化方面却是未知的.为了揭示mir-430基因簇的起源及其在相关物种的进化关系,文中基于miRNA序列同源保守的特点,采用BLAST程序在NCBI基因数据库中搜索mir-430序列,在14个物种中共搜索到35个mir-430基因序列,这14个物种都为硬骨鱼类.多序列对比发现mir-430基因簇成熟序列的第2到第8位碱基以及第16到第22位碱基为保守序列.进化分析表明七鳃鳗的pma-mir-430基因可能是此基因家族最早出现的基因形式,并且pma-mir-430e可能是其他物种mir-430基因的祖先基因.祖先基因经过个别碱基的缺失及突变、串联重复和大片段重复等方式形成了mir-430基因簇.该研究通过分析不同物种中mir-430基因簇的特征,揭示mir-430基因簇的分子进化规律,为其调控网络和功能研究提供理论基础.     

昆虫致病性斯氏线虫亲环素基因的克隆、特征及表达分析

亲环蛋白(Cyclophilin)广泛存在于原核和真核生物中,在进化过程中结构保守,多数具有肽基脯氨酰基顺反异构酶活性。本文在斯氏线虫(Steinernema car poca psae)差减杂交分析的基础上,克隆一个亲环蛋白基因(Sca-CYN)。该胞质蛋白有171个氨基酸组成,分子量约为16.2kD,等电点约为6.89。BLAST分析表明,Sca-CYN蛋白与线虫、昆虫及其它生物亲环蛋白的序列一致性达75%~89%。基因表达分析显示该基因在寄生初期就上调表达。序列比较及进化标记分析发现Sca-CYN为秀丽隐杆线虫亲环蛋白3的直系同源蛋白。同源建模分析显示该蛋白具有亲环蛋白的经典三维结构。系统发育分析结果表明该蛋白在进化早期与其同源基因分离。研究结果为进一步研究该基因功能及探讨线虫亲环蛋白基因家族的分子进化提供基础。
     

昆虫致病性斯氏线虫亲环素基因的克隆、特征及表达分析(英文)

亲环蛋白(Cyclophilin)广泛存在于原核和真核生物中,在进化过程中结构保守,多数具有肽基脯氨酰基顺反异构酶活性。本文在斯氏线虫(Steinernema carpocapsae)差减杂交分析的基础上,克隆一个亲环蛋白基因(Sca-CYN)。该胞质蛋白有171个氨基酸组成,分子量约为16.2kD,等电点约为6.89。BLAST分析表明,Sca-CYN蛋白与线虫、昆虫及其它生物亲环蛋白的序列一致性达75%~89%。基因表达分析显示该基因在寄生初期就上调表达。序列比较及进化标记分析发现Sca-CYN为秀丽隐杆线虫亲环蛋白3的直系同源蛋白。同源建模分析显示该蛋白具有亲环蛋白的经典三维结构。系统发育分析结果表明该蛋白在进化早期与其同源基因分离。研究结果为进一步研究该基因功能及探讨线虫亲环蛋白基因家族的分子进化提供基础。     

中华绒螯蟹线粒体COⅡ基因全序列测定

通过克隆测序方法,报道了中华绒螯蟹（Eriocheir japonica sinensis)线粒体细胞色素氧化酶亚基Ⅱ(COⅡ）基因全序列,与已知甲壳动物线粒体同源序列的比较显示,绒裂蟹COⅡ基因的核苷酸组成及其编码的氨基酸组成与软甲类甲壳动物最相近似。其序列组成与密码子使用对A、T核苷酸没有明显的偏倚,对中华绒螯蟹COⅡ全序列及其序列特征的研究,为进一步研究短尾类的系统发生和绒螯蟹属的分子进化提供了分子标记。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that