采用AFLP分析齐口裂腹鱼DNA指纹的技术探讨

AFLP（选择性扩增片断长度多态性）指纹技术被认为是当今最有效的DNA指纹分析技术之一,但是由于该技术操作流程较长,对模板DNA质量要求较高以及PCR反应成分等变数条件的影响,要获得高清晰的DNA指纹图谱比较困难。文中以齐口裂腹鱼为研究对象,对AFLP的分析条件作了一定的探索。结果表明：基因组DNA必须是高纯度、高分子量;酶切充分;PCR反应最佳条件为：引物E—XYZ,M—XYZ在体系中的浓度分别为1ng／mL,5ng／mL;dNTPs浓度为0．2mmol／L;MgCl2浓度为1．9mmol／L。银染时在NaOH条件下显色比在传统银染法中的Na2CO3条件下显色,图谱背景更干净,条带更清晰。     

应用RAMP分子标记探讨仲彬草属的种间关系

对仲彬草属Kengyilia14个种和1个变种进行了RAMP分析。结果表明物种间遗传差异明显。40个引物组合产生的254条DNA扩增片段中，216条(85．0％)具有多态性，每个引物组合可扩增出l一9条多态性带，平均5．4条。遗传相似系数变化范围为0．327—0．886，平均值为0．549。同时，形态相似、地理分布一致的物种有一定的亲缘关系，聚类在一起。这与RAPD、形态学和细胞学等分析结果基本一致。因此，RAMP评分子标记是评价仲彬草属种间关系十分有效的方法。     

采用AFLP分析齐口裂腹鱼DNA指纹的技术探讨

AFLP(选择性扩增片断长度多态性)指纹技术被认为是当今最有效的DNA指纹分析技术之一,但是由于该技术操作流程较长,对模板DNA质量要求较高以及PCR反应成分等变数条件的影响,要获得高清晰的DNA指纹图谱比较困难.文中以齐口裂腹鱼为研究对象,对AFLP的分析条件作了一定的探索.结果表明:基因组DNA必须是高纯度、高分子量;酶切充分;PCR反应最佳条件为:引物E-XYZ,M-XYZ在体系中的浓度分别为1 ng/mL,5ng/mL;dNTPs浓度为0.2mmol/L;MgCl2浓度为1.9mmol/L.银染时在NaOH条件下显色比在传统银染法中的Na2CO3条件下显色,图谱背景更干净,条带更清晰.     

天鹅洲保护区长江江豚AFLP遗传多样性分析

应用AFLP技术对天鹅洲白豚国家级自然保护区的长江江豚 (Neophocaenaphocaenoidesasiaeorientalis)群体进行了遗传多样性分析。每个AFLP引物组合在群体中检测到 0到 6个不等的多态性片段 ,平均为 2 .4 8个。 2 1个引物组合共揭示了 1139个座位 ,其中 5 2个座位具有多态性。多态性座位所占比例为 4 .6 %。分析显示群体的遗传期望杂合度 (He)为 0 .4 430± (SE0 .0 12 2 2 )。研究结果表明保护区长江江豚群体具有适度的核DNA遗传多样性水平。为了该群体的长期生存与发展 ,更多的具有不同遗传变异的个体应该被迁入保护区 ,以形成更大的群体 ,获得更好的群体遗传结构     

利用AFLP技术分析中国明对虾的韩国南海种群和养殖群体的遗传差异

利用AFLP技术对新发现的中国明对虾的一个地理种群——韩国南海种群（SP）和中国明对虾的养殖群体（CP）进行了遗传分析。每个群体随机取样30个,5对AFLP引物获得326个位点。其中SP多态位点比例（P0.99）46.93％,Shannon多样性指数（Ⅰ）0．1884,Nei（1978）基因多样性指数（h）0．1197,群体差异性位点9个,占检测位点总数的2．7％。CP多态位点比例（R9q）51．84％,Shannon多样性指数（Ⅰ）0．1954,Nei（1978）基因多样性指数（h）0．1229,群体差异性位点19个,占检测位点总数的5．8％。SP种群各项遗传参数都低干CP种群。两个群体的非偏差遗传相似度和遗传距离分别为0．9899和0．0102。利用中国明对虾的韩国南海种群和养殖群体杂交可以获得新的种质资源,这将为获得最大变异数量性状表型和基因多样性的产生提供可能。     

中国对虾人工选育快速生长群体不同世代间的AFLP分析

利用7对AFLP引物组合检测了中国对虾连续五代选育群体基因组DNA的遗传结构,根据AFLP分析结果计算了选育世代群体间的遗传相似系数和遗传距离.结果表明,AFLP标记表现出较高的多态检测效率,7对引物共产生500余条带,平均每对引物组合检测到33.7个多态性标记,平均杂合度为0.0854～0.1025,非常适合于遗传多样性分析.结果显示,随着选育世代的增加,选育群体的遗传多样性呈现下降趋势,但随着选育时间的延长,群体之间的分化逐渐降低,群体的遗传结构开始趋于稳定,成为一个品系.     

红鳍东方鲀与假睛东方鲀的微卫星DNA多态性分析

为了对中国近海分布的红鳍东方鲀（Takifugu rubripes）资源进行深入调查,以确定红鳍东方鲀与假睛东方鲀（Takifugu pseudommus）的种间关系,利用根据红鳍东方鲀基因组序列设计的9对微卫星引物,对野生红鳍（WR）、野生假睛东方鲀（WP）两个地理种群和一个养殖红鳍东方鲀（CR）群体进行了遗传多样性分析。结果表明：9对引物在三个群体中均表现为多态;共获得106个等位基因,每个位点的等位基因数目在5～25之间,9个位点在三群体观测杂合度的范围从0．8167到1．0000,三群体平均杂合度观测值E,排列顺序为wR（0．8661）〉WP（0．8272）〉CR（0．7832）;3个群体之间的遗传距离较小,其中WR和WP群体间的遗传距离最小（0．0586）,WR和CR群体的遗传距离最大（0．0923）;3群体的遗传分化系数Gsr很小,其中,WR和WP两群体间遗传分化系数最小（0．0177）,WR和CR群体间的遗传分化系数最大（0．0290）,与遗传距离的分析结果相一致。群体遗传结构的分析结果表明：红鳍东方鲀养殖群体遗传多样性显著下降,应及早加强对其种质的保护;从分子遗传学的角度来看,红鳍东方鲀与假睛东方鲀应为同一个种。     

用RAPD技术对我国栉孔扇贝野生种群与养殖群体的遗传结构及其遗传分化的研究

利用RAPD技术对我国栉孔扇贝野生种群和养殖群体的遗传结构及其分化进行了研究，在对20个野生栉孔扇贝和20个养殖栉孔扇贝的基因组DNA的检测中，20个10碱基的随机引物共扩增出153条清晰可分辨的DNA片段，片段的长度为200－3000bp其中多态性片段分别为116和112条，野生种群和养殖群体的多态位点比例分别为75．82％，和73．47％，杂合度分别为0．27和0．26。根据基因频率计算出两个群体的近交系数为0．00129，遗传距离为0．028。栉孔扇贝野生种群的多态位点比例和杂合度处于较高水平，说明我国栉孔扇贝野生种群的遗传多样性水平较高，种质资源尚处于较好状态，应制定相应的渔业生产和管理措施加以保护，养殖群体的多态位点比例和杂合度都低于野生种群，这与人工累代养殖过程中，群体较小，近交机会增加有关。     

五个紫菜品系间遗传差异的RAPD分析

应用随机引物扩增片段多态性（RAPD）技术对2种紫菜的5个品系进行遗传多样性分析。共筛选出21条随机引物,PCR反应得到147条扩增片段。根据共享扩增片段计算遗传相似性指数（F）和相对遗传距离,利用NJ法构建系统树。结果表明,条斑紫菜或坛紫菜的养殖品系首先聚类在一起,两个条斑紫菜养殖品系之间的遗传距离是0．32,两个坛紫菜养殖品系之间的遗传距离是0．31。条斑紫菜养殖品系CPY1－08A与坛紫菜养殖品系CPH8－83之间的遗传距离最大,达0．42。本文结果显示RAPD可以作为简便有效的分子工具应用于紫菜的遗传多样性和种质鉴定研究中。     

中药黄芪指纹图谱分析研究概况

本文通过对中药黄芪指纹图谱分析应用的综述,阐述了中药指纹图谱分析的概念和特点,介绍了各种有关类型指纹图谱的研究,并指出黄芪及其制剂指纹图谱的分析还应进一步全面深入研究。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.