棉花GhADF7基因结构与进化分析

ADF蛋白是一种在真核生物中广泛存在的低分子量的肌动蛋白结合蛋白,在细胞分裂、细胞运动、花粉管伸长等重要的生命活动中发挥着重要的作用．我们以陆地棉（Gossypium hirsurum）叶片DNA为模板,通过聚合酶链式反应（PCR）扩增分离获得棉花GhADF7基因．该基因长度为902bp,包含420bp阅读框;编码区含有3个外显子和2个内含子;其编码的ADF蛋白含有139个氨基酸残基．GhADF7与其它生物的ADF蛋白具有较高的同源性．其中GhADF7与NtADF1,NtADF2的亲缘关系较近,与LIADF、ZmADF的亲缘关系次之,它们的氨基酸序列同源性在75％～79％之间．上述系统发育进化分析表明,植物ADF基因具有高度保守性．     

油茶苯丙氨酸解氨酶基因的cDNA克隆与序列分析

苯丙氨酸解氨酶(phenylalanine ammonia lyase, PAL)是苯丙烷类代谢途径的关键酶之一。以油茶(Camellia oleifera)近成熟种子cDNA文库和EST文库为材料,通过分子克隆方法鉴定了PAL全长cDNA。结果表明：油茶PAL基因的cDNA长2 118 bp,编码705个氨基酸,与其他物种的PAL具有较高的相似性,在进化上高度同源;油茶PAL编码的蛋白质序列包含与水稻、玉米PAL蛋白质相同的脱氨基位点和催化活性位点;PAL系统进化树表明, 油茶PAL基因与灌木类植物的PAL基因聚类关系最近。     

甘薯类胡萝卜素合成酶基因pds全长cDNA的克隆

根据双子叶植物类胡萝卜素合成结构基因氨基酸保守区域设计简并引物,扩增出甘薯编码类胡萝卜素合成关键酶PDS的基因(pds)cDNA中间片断。通过5'-RACE和3'-RACE技术进行cDNA末端的快速扩增,成功地克隆了pds的全长cDNA。序列分析表明,pds基因的全长cDNA序列长度为2128 bp,编码572个氨基酸,与其他植物的序列高度同源。     

枇杷番茄红素β环化酶基因片段的克隆和序列分析

根据蔷薇科植物番茄红素β环化酶（LYC）基因的保守区序列，设计1对PCR引物，以枇杷基因组DNA为模板，采用PCR方法扩增长约300bp的DNA片段，克隆人pMD-18T载体，测得该基因片段长312bp，编码102个氨基酸，属于开放阅读框的一部分，不含内含子。在GenBank中进行同源性检索表明该序列与苹果番茄红素β环化酶基因同源性为97％，由此推测这个基因属于枇杷番茄红素β环化酶基因。     

氨基酸序列分析揭示苯丙氨酸/酪氨酸解氨酶在陆生植物中的演化

苯丙烷途径在陆生植物木质素和黄酮类等次生代谢产物的生物合成中至关重要，其中一步必需的反应为苯丙氨酸解氨酶(PAL)将底物苯丙氨酸脱氨催化为下游产物。最新研究发现了能够同时催化苯丙氨酸和酪氨酸脱氨的双功能酶—苯丙氨酸/酪氨酸解氨酶(PTAL),但是对诸多问题，例如怎样精准鉴定PAL和PTAL、植物PAL演化为PTAL其氨基酸序列发生了什么变异、哪些植物类群包含PTAL等，仍属未知。为了探索PAL基因家族在陆生植物中的演化及关键变异，本研究利用PAL氨基酸全长序列构建了陆生植物不同类群系统发育树，比较和分析了PAL和PTAL氨基酸序列并模拟了其蛋白质三维构象。结果表明，以PAL氨基酸序列构建的系统发育树，能够反映已知陆生植物的系统关系，PAL和PTAL的氨基酸序列中存在着8个差异位点，其中121和123这两个关键位点非常稳定，可以联合用于准确鉴定包含PAL和PTAL的植物，并且I121L和F123H的关键变异，导致只能与苯丙氨酸结合的PAL演化为也能同时结合酪氨酸的PTAL。     

鸡新城疫病毒ND-xx08株F基因的克隆及分析

新城疫病毒（NDV）ND-xx08毒株经10 d龄SPF鸡胚增殖后,提取其基因组RNA并反转录成cDNA,用NDV F基因特异性引物,经PCR扩增后获得与F基因预期大小一致的DNA片段。将NDV F基因片段克隆到pMD18-T载体上,并进行EcoR I和Hind III双酶切鉴定和测序鉴定。结果显示,ND-xx08毒株F基因片段的长度为1 662 bp,共编码554个氨基酸,F蛋白的裂解位点为112R-R-Q-K-R-F117,是典型强毒株氨基酸序列结构。将NDV ND-xx08株F基因的47 bp到420 bp序列与新城疫病毒基因型I至基因型Ⅸ毒株的相同序列绘制病毒基因进化树,显示ND-xx08分离株属于基因Ⅶe型。将NDV ND-xx08株F全基因与国内外发表的23株NDV F基因核苷酸序列和氨基酸序列的同源性比较分析,结果表明,其核苷酸序列的同源性在82.7%~97.8%之间,氨基酸同源性在87.5%~97.7%之间。     

蓖麻PsbO基因的克隆与序列分析

用实验室栽培的蓖麻新鲜叶片为材料,Trizol法提取总RNA,参照GenBank公布的植物PsbO氨基酸序列,进行序列比对找出氨基酸序列保守区设计简并引物,通过RT-PCR扩增目的片段,纯化后克隆到T-Vector中测序,获得蓖麻的PsbO基因,对其基因序列进行分析。了解到其长度为1081bp,5＇非编码区为10bp,3＇非编码区为273bp,编码区长798bp,编码266个氨基酸。序列分析结果表明,蓖麻PsbO基因编码的氨基酸序列与已公布的其他植物中克隆到的PsbO氨基酸序列有较高的同源性。     

白菜快速碱化因子基因BcMF14的克隆及序列分析

快速碱化因子是近年来新发现的一种植物多肽类信号分子．从一个在‘矮脚黄’白菜雄性不育两用系的可育株系中特异表达的cDNA—AFLP差异片段入手,采用RACE技术克隆了该片段的基因,将其命名为BcMF14,全长581bp,不含内含子,开放阅读框长度为240bp,编码79个氨基酸．序列分析结果表明该基因与花椰菜、拟南芥等的快速碱化因子基因cDNA序列有很高的相似性,证明BcMF14属于快速碱化因子家族．     

野桑蚕漆酶基因克隆、序列分析及转录表达谱研究

利用RT-PCR方法,克隆了野桑蚕Bombyx mandarina漆酶基因,获得了其cDNA序列.该序列长2 317bp,含有一个2 295bp的完整开放阅读框,有8个外显子,7个内含子,编码一个由764个氨基酸残基组成的蛋白质,其蛋白质的分子量和等电点分别为84 340.91和6.61.推导的氨基酸序列与其它鳞翅目昆虫(Laccase)基因相应氨基酸序列有较高的同源性,该序列具有它们的漆酶基因所共有的典型特征.组织特异性表达分析表明了该基因仅在野桑蚕的表皮、头部、中肠和血液中有表达.这些结果为进一步研究野桑蚕漆酶基因的功能提供了分子基础.     

猪Klf4、Klf5和Egr2基因内含子的克隆及进化分析

从猪肝脏提取基因组作为模板,分别扩增了Klf4、Klf5和Egr2的第3、第2和第1内含子,长度分别为916、1027和1342bp,并通过其两端连接的部分外显子序列与Genbank序列比对加以确认,并和人相应基因内含子作长度和序列同源性比较。结果表明,由内含子比对得出的这些基因在人和猪间的保守程度与这些基因在氨基酸水平上比对得出的保守程度相一致。     

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