粪肠球菌中具有启动功能的DNA片段的捕获及鉴定

PCR扩增来自质粒pUC119的β-内酰胺酶基因(bla)作报告基因,克隆进质粒pNZ8037上的能被Nisin诱导的启动子PnisA下游,构建了粪肠球菌启动功能片段探测载体pNZ-bla.利用该探测载体从粪肠球菌染色体总DNA中克隆到了能在粪肠球菌中表达的一系列具有启动功能的DNA片段,将包含克隆片段的pNZ-P-bla6质粒电击转化粪肠球菌,培养转化子并检测其抗氨苄强度,结果表明其抗氨苄强度大于Nisin诱导的含pNZ-bla质粒的粪肠球菌.表明克隆的功能片段启动能力强于PnisA.在pNZ-P-bla6的启动功能片段下游Sau3AⅠ和EcoRⅠ之间接上绿色荧光蛋白基因作为标记,构建表达绿色荧光蛋白的质粒载体pNZ-P-gfp并导入粪肠球菌中,共聚焦显微镜下可以观察到绿色荧光蛋白的表达.     

藏绵羊肠道乳酸菌的分离鉴定及系统进化分析

为解藏绵羊肠道乳酸菌的菌群组成及其基本生物学特征,无菌采集12头健康藏绵羊新鲜粪便,分离培养及纯化乳酸菌株,并通过16S rDNA序列扩增和测序进行分子鉴定.结果显示:从12个样本中共分离纯化出19株乳酸单菌,分属于7个属,其中鹑鸡肠球菌、海氏肠球菌、粪肠球菌及植物乳杆菌所占分离比例较多.该结果为进一步了解藏绵羊肠道乳酸菌的菌群种类及藏绵羊益生菌制剂的开发提供了基础.     

人RIP2基因启动子绿色荧光蛋白表达载体的构建与鉴定

目的:构建人RIP2基因启动子的绿色荧光蛋白表达载体。方法:根据特定限制性内切酶位点,以人基因组DNA为模板,PCR扩增含人RIP2基因启动子不同长度2段序列,构建含人RIP2基因启动子驱动的绿色荧光蛋白载体pEGFP-C2-RIP2(750 bp)wt、pEGFP-C2-RIP2(941 bp)wt,用VspⅠ和NheⅠ双酶切鉴定重组质粒,进行DNA序列分析,重组质粒经阳离子聚合物JetPeiTM介导转染HEK293细胞48 h后观察。结果:酶切鉴定和序列测定证实目的基因已插入重组质粒;细胞转染结果表明,重组质粒转染HEK293细胞均能表达绿色荧光,其中构建的pEGFP-C2-RIP2(750 bp)wt重组质粒绿色荧光表达强于pEGFP-C2-RIP2(941 bp)wt。结论:成功构建2段不同长度的人RIP2基因启动子绿色荧光蛋白表达载体。     

人NOD8基因启动子绿色荧光蛋白表达载体的构建与鉴定

目的:构建人NOD8基因启动子的绿色荧光蛋白表达载体.方法:用特定的限制性内切酶位点,以人基因组DNA为模板,PCR扩增含有人NOD8基因启动子不同长度2段序列,并进行酶切以切除启动子的pEGFP-C2作框架结构,插入表达载体pEGFP-C2中,构建含有人NOD8基因启动子驱动的绿色荧光蛋白载体pEGFP-C2-NOD8(520 bp)、pEGFP-C2-NOD8(760 bp),用Vsp Ⅰ和Nhe Ⅰ双酶切和PCR鉴定重组质粒,再将重组质粒进行DNA序列分析.构建的重组质粒经脂质体(lipofectamine)TM2000介导转染HEK293、K562和HeLa细胞,转染48 h后在倒置荧光显微镜下观察.结果:pEGFP-C2-NOD8(520 bp)、pEGFP-C2-NOD8(760 bp)分别经酶切鉴定和序列测定证实目的基因已插入重组质粒;细胞转染结果表明,构建的2段重组质粒转染HEK293、K562及HeLa细胞均能表达绿色荧光,其中构建的pEGFP-C2-NOD8(760 bp)重组质粒绿色荧光表达强于pEGFP-C2-NOD8(520 bp).结论:成功构建2段不同长度的人NOD8基因启动子绿色荧光蛋白表达载体.     

绿色荧光蛋白(GFP)基因在短小芽孢杆菌中的组成型表达

采用PCR技术,亚克隆来自短小芽孢杆菌总基因组中的启动子活性片段F1,构建了一个大肠杆菌-短小芽孢杆菌穿梭表达载体pHY300-F1gfp,以缺失启动子的绿色荧光蛋白(GFP)基因为报告基因,检测了该片段在短小芽孢杆菌DX01菌株中的启动活性,在荧光显微镜下,观察到了明亮的绿色荧光,证实活性片段F1具有组成型启动子的功能,GFP基因在短小芽孢杆菌中实现了组成型表达．     

破囊壶菌Δ4-脂肪酸脱饱和酶基因5''端侧翼区域的克隆与鉴定

应用衔接头PCR(LA-PCR)技术,扩增得到约1000 bp的海洋破囊壶菌Δ4-脱饱和酶基因5’端侧翼区域的单一产物.对该产物测序,经启动子软件与序列比对分析,发现该序列(Genkbank登录号EU074209)具有真核启动子序列的基本结构特征,含有TATA盒、CAAT盒、INR等元件.将扩增得到的脱饱和酶基因5’端侧翼序列亚克隆到含有绿色荧光蛋白(GFP)报告基因的质粒pGlow-TOPO中,构建重组表达质粒,转化大肠杆菌细胞.荧光显微观察大肠杆菌阳性转化子发出荧光,侧翼序列含有启动子功能得到确认.     

新生儿粪便中分离的粪肠球菌(Enterococcus faecalis)RZ18提高肠道黏膜屏障完整性

本实验旨在研究新生儿粪便样品中乳酸菌对肠道黏膜屏障完整性的促进作用.从健康新生儿粪便中分离出15株乳酸菌.对这些乳酸菌进行耐酸、耐胆盐和细胞黏附能力的实验,分析其定植能力.再通过荧光素酶报告基因分析实验、实时荧光定量PCR(Real-timePCR)、酶联免疫吸附测定检测各菌发酵上清液对HT-29细胞中黏蛋白2(mucin2,MUC2)表达的影响,结果显示粪肠球菌(Enterococcusfaecalis)RZ18发酵上清液对MUC2启动子活性、转录和翻译水平均有增强作用.并通过Real-timePCR、免疫印迹实验检测E. faecalisRZ18发酵上清液对肠道黏膜屏障中闭锁蛋白、封闭蛋白1、闭锁小带蛋白1表达的影响,发现该菌可以促进这些紧密连接蛋白的表达.最后用牛津杯法研究发现该菌对藤黄微球菌、金黄色葡萄球菌、单增李斯特菌和大肠杆菌等多种致病菌生长具有抑制作用.上述结果说明,新生儿肠道早期定植的E. faecalis可能对新生儿肠道黏膜屏障完整性的发育具有促进作用,有望应用于炎症性肠病的预防与治疗.     

几种诱导昆虫细胞RNA干扰质粒的构建和效果比较

构建了四种可以在昆虫细胞中表达形成dsRNA的质粒,比较了其诱导RNA干扰,抑制目标基因———绿色荧光蛋白(GFP)基因表达的效果.四种质粒都不同程度地抑制了质粒介导的GFP表达,其中尤以单个果蝇hsp70启动子表达反向重复序列,并带有杆状病毒AcMNPV增强子hr5的质粒效果最佳,使GFP表达量下降到原来的3.9%.当用于抑制由杆状病毒介导的GFP表达时,以两个相向排列的AcMNPV ie1基因启动子的构造有明显的抑制效果.这些结果对于在昆虫细胞中有效地利用RNA i研究基因功能有参考意义.     

融合型乳酸片球菌素在大肠杆菌中的表达与纯化

为在大肠杆菌中高效表达乳酸片球菌素(PED),按照美国国立生物技术信息中心公布的PED基因序列设计合成引物,以乳酸片球菌基因组DNA为模板,用多聚酶链式反应扩增PED结构基因特异片段,构建编码组氨酸标记硫氧还原蛋白融合PED的重组表达质粒pET32c-PED,并转化大肠杆菌BL21(DE3).在异丙基硫代半乳糖苷诱导后融合蛋白以包涵体形式表达,表达量占菌体总蛋白的28%.经镍亲合层析纯化的融合蛋白用肠激酶裂解,再经超滤纯化,可得78%的收率.融合蛋白没有抗粪肠球菌细菌素活性,被分开的PED恢复了抑菌活性.     

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.     

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.     

A computer generator for randomly layered structures

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

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

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