酿酒酵母蛋白激酶Sch9的PDK1位点调控C末端磷酸化状态

利用酿酒酵母蛋白激酶Sch9(哺乳动物p70S6k1的同源物)PDK1和PDK2位点点突变的两种突变体,分别进行生长、寿命表型检测及免疫印迹分析实验,发现PDK1位点的磷酸化水平对于Sch9活性起着主导性作用,并且PDK1位点发生去磷酸化会促进C末端高度磷酸化,而PDK1发生磷酸化会抑制C末端的磷酸化.由此说明Sch9上PDK1和PDK2位点是否发生磷酸化除了受到各自上游激酶的调节外,两者之间还存在着一种负调控机制.     

酵母(Saccharomyces cerevisiae )蛋白激酶SCH9激活环磷酸化调控胁迫应答

通过比较野生型、△sch9和△sch9(SCH9-3HA)三种酵母茵种在葡萄糖、半乳糖、蔗糖和麦芽糖作碳源培养基上的生长表型研究SCH9是否参与酵母不同碳源代谢利用调控.结果显示,△sch9细胞茵落大小较野生型细胞小且有明显的生长缺陷,但这种生长缺陷在重新获得sch-3HA基因后得到恢复.通过比较野生型、△sch9和△sch9(SCH9-3HA)三种酵母茵种在渗透压胁迫和热胁迫条件下的生长表型发现sch9可能参与了酵母胁迫应答.利用抗SCH9570位磷酸化苏氨酸特异性抗体(anti-T570-P),通过变性免疫沉淀和免疫印迹方法,研究了生理条件下的△sch9(SCH9-3HA)细胞裂解液中SCH9激活环的磷酸化状态.结果显示,在生理条件下SCH9激活环T570位点发生了明显磷酸化.进一步研究了渗透压胁迫条件下SCH9激活环T570位点的磷酸化水平.结果表明,渗透压胁迫条件下SCH9激活环T570位点磷酸化水平较生理条件下显著增强.结果显示SCH9可能通过增强激活环磷酸化水平来参与调控酵母不同碳源代谢和胁迫应答.     

Sch9通过Cdc34调控酵母细胞的寿命和胁迫应答

为研究Sch9激酶的生理功能,本文首先通过同步细胞周期的方法发现Sch9的PDK1位点的磷酸化随细胞周期变化.接下来在酵母中过表达Cdc34显示Cdc34的组成性表达可以进一步延长s ch9△突变体的寿命并且增强其对氧化胁迫及热胁迫的抗性.我们的研究结果首次表明Cdc34作为Sch9的底物参与细胞胁迫应答和衰老的调控.     

决策树算法预测人类病毒的蛋白质磷酸化位点

本文基于决策树分类算法构建人类病毒蛋白质磷酸化修饰位点的预测模型。采用氨基酸物理化学性质对蛋白质序列进行特征提取,并分析丝氨酸、苏氨酸和酪氨酸磷酸化位点邻近序列的氨基酸性质。同时考察了不同分类算法对预测结果的影响。通过10倍交叉验证,利用决策树算法预测丝氨酸、苏氨酸和酪氨酸磷酸化位点的MCC分别达到77.31%、75.91%和71.94%,表明本文提出的方法能有效地预测人类病毒的磷酸化修饰位点。     

药用植物黄花蒿ATP合成酶电子克隆及生物信息学分析

本文通过电子克隆的方法获得黄花蒿ATP合成酶的基因完整序列并对该蛋白特性进行相应分析.以Accession number KJ434435.1为探针,对黄花蒿的EST数据库进行搜索,获得同源较高的序列,用相关生物软件DNAMAN、MEGA进行拼接组装,并对获得核苷酸和氨基酸进行生物信息学分析.结果发现获得黄花蒿ATP合成酶基因拼接群1963bp,含有一个完整的开放阅读框(ORF)序列(1479bp),编码492个氨基酸,该蛋白质含15个α螺旋,23个β折叠及27个无规则卷曲.黄花蒿ATP合成酶蛋白的分子质量为52830.4,分子式为C_(2342)H_(3778)N_(636)O_(721)S_(14),理论等电点为5.18,该蛋白的GRAVY值为-0.048,具有亲水性的水溶性蛋白.该蛋白质序列有丝氨酸磷酸化位点(Ser)9个、苏氨酸磷酸化位点(Thr)6个、酪氨酸磷酸化位点(Tyr)4个.通过分析获得黄花蒿ATP合成酶完整的c DNA序列,该氨基酸序列不存在信号肽,无跨膜现象、非分泌型蛋白,为黄花蒿ATP合成酶实验室研究提供一定的理论基础.     

人类病毒蛋白质磷酸化修饰位点的识别研究

蛋白质磷酸化翻译后修饰在病毒的复制和抑制宿主细胞功能方面发挥重要的作用。然而,利用实验的方法识别磷酸化位点既费时费力又耗财。因此基于蛋白质氨基酸序列发展一种机器学习方法对病毒蛋白磷酸化位点进行预测显得非常有必要。研究结合支持向量机提出识别病毒蛋白磷酸化位点的新方法。采用权重氨基酸成分和属性分组编码对病毒蛋白残基的氨基酸物理化学性质和序列信息进行特征提取,通过10倍交叉验证,丝氨酸、苏氨酸和酪氨酸磷酸化位点的预测准确率分别达到82.0%、85.8%和92.4%。运用该预测模型对丝氨酸残基磷酸化的激酶组进行分类评估,CMGC、AGC和CAMK激酶组的马氏相关系数分别达到69.3%、68.8%和68.2%。结果表明:构建的方法可以有效地预测激酶特异性的磷酸化位点。     

基于 LibSVM 的 CKSAAP 蛋白特征提取预测水稻蛋白质磷酸化位点

本文从swiss-prot中选取经过试验验证的水稻蛋白质磷酸化位点数据作为训练集合，应用蛋白质序列特征提取方法Composition of k-spaced residues pairs （CKSAAP），为利用SVM算法构建专门针对水稻蛋白质磷酸化位点的预测工具做准备。 CKSAAP方法利用在序列片断中残基的K个间隔距离的组成，进一步反映了残基之间的相关性。本文利用LibSVM软件包对已通过改进过得CKSAAP方法特征提取出来的数值特征对磷酸化位点进行预测，从而为之后构建水稻蛋白质磷酸化位点的预测工具做准备。结果表明，本文基于SVM和CKSAAP方法的水稻蛋白质磷酸化位点预测在丝氨酸，苏氨酸和酪氨酸的平均预测准确性为80．638％，马修斯系数为0．611。与PlantPhos和Musite的预测性能的对比结果显示，在磷酸化各氨基酸位点的预测性能高于PlantPhos及Musite。     

藏鸡POU1F1基因的克隆测序及生物信息学分析

为研究青藏高原特有鸡种,藏鸡的生物学特性,从藏鸡垂体组织的RNA中克隆POU1F1基因,并利用生物信息学对其进行分析.结果显示,藏鸡POU1F1基因开放阅读框(ORF)长为984bp,编码327个氨基酸.编码序列中有13个丝氨酸(Ser)、2个酪氨酸(Tyr)、6个苏氨酸(Thr)磷酸化位点;1个N糖基化位点;二级结构主要由α-螺旋和无规则卷曲构成;藏鸡POU1F1氨基酸序列与红色原鸡POU1F1氨基酸序列的亲缘关系最近.藏鸡POU1F1基因氨基酸序列可能与藏鸡生长速度慢的特性相关.这一研究结果为今后的藏鸡育种工作提供重要的靶点和参考.     

短尾蝮蛇毒金属蛋白酶和磷脂酶A_2的分离纯化及磷酸化修饰检测

利用阴离子层析、凝胶排阻色谱和反相高效液相色谱从短尾蝮蛇毒中分离金属蛋白酶和磷脂酶A2,用蛋白印迹法检测两种组分的磷酸化修饰信号,结合LC-MS质谱鉴定并预测磷酸化修饰位点.结果表明,利用3种色谱法串联组合,最终分离获得两种条带单一且纯度高的短尾蝮蛇毒蛋白,经LC-MS质谱鉴定分别为蛇毒金属蛋白酶和磷脂酶A2.免疫印迹检测发现这两种蛇毒蛋白受到明显的磷酸化修饰,解析质谱图发现蛇毒金属蛋白酶有4个氨基酸位点受到潜在的磷酸化修饰(含1个丝氨酸和3个苏氨酸),磷脂酶A2仅有1个酪氨酸位点受到潜在的修饰.所得结果是磷酸化位点修饰抗体在蛇毒蛋白磷酸化修饰信号检测中的一次尝试,基于修饰位点的预测可为蛇毒蛋白功能受磷酸化修饰影响的研究提供基础.     

甘蔗抗坏血酸过氧化物酶的电子克隆及生物信息学分析

电子克隆是随着EST计划和生物信息学发展起来的基因克隆策略。运用电子克隆的方法获得甘蔗S-APX2基因。以水稻中一个基因OsAPX2为种子序列,对甘蔗的EST数据库进行搜索,应用相关软件进行预测和分析。获得一个甘蔗APX基因S-APX2的cDNA序列全长,该序列长1110bp,包含一个完整的975bp的ORF,编码324个氨基酸;属于疏水性蛋白,编码蛋白含有Heme binding site,Substrate binding site,K+binding site,Ascorbate-peroxidase结合位点和保守域,属于Plant-peroxidase-like Superfamily家族;亚细胞定位分析显示,编码蛋白位于植物细胞的线粒体中。具有5个丝氨酸磷酸化位点,9个苏氨酸磷酸化位点以及1个酪氨酸磷酸化位点;存在信号肽但是无跨膜结构域,二级结构由30.74%α螺旋、13.92%延伸链和40%无规则卷曲组成;且与水稻、玉米等其他植物的APX具有高度的同源性。电子克隆获得了完整的甘蔗APX基因全长cDNA。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to