镍化磁性琼脂糖凝胶微球的制备及其在蛋白纯化中的应用研究

以自制磁性琼脂糖微球为基质,环氧氯丙烷为活化剂,亚氨基乙二酸作为螯合剂,制备了表面螯合Ni2＋的磁性凝胶微球（Mag—Agarose—Ni）．IR结果表明Ni2＋成功螯合到了磁性凝琼脂糖胶微球上;SEM结果显示在螯合Ni2＋后,Mag—Agarose-Ni形貌没有发生明显变化,且平均粒径为23btm;原子吸收光谱结果表明Mag—Agarose-Ni表面螫合的Ni2＋的量为2．12×10mol／mg;磁性能测试表明Mag—Agarose-Ni具有超顺磁性,其磁饱和强度为20．8emu／g,具有良好的磁响应性．将Mag—AgaroseNi用于六聚组氨酸融合蛋白K8的纯化研究,SDS-PAGE结果表明Mag—Agarose—Ni较市售Ni—NTA对K8具有更优的亲和分离效果,经15min的孵育后,Mag—Agarose—Ni对K8的吸附容量可达到8．8μg／mg．     

高磁性壳聚糖微粒的制备与应用

采用壳聚糖包埋磁粉，经戊二醛修饰、环氧氯丙烷交联制得高磁性壳聚糖微料。此微粒共价结合卵清粘蛋白得到磁性亲和吸附剂，可应用于胰蛋白酶的亲和纯化。     

利用氨基苄脒为配基的亲和层析法纯化t—PA

利用氨基苄脒修饰的硅胶为亲和吸附剂纯化组织纤溶酶原激活剂（ｔ－ＰＡ），讨论了亲和柱体积对纯化效率的影响。由于氨基苄脒对ｔ－ＰＡ的高度特异性，根据ｔ－ＰＡ的上柱量适当调整柱体积，可使纯化倍数达到１４０以上，远高于利用其它亲和吸附剂的结果。     

琼脂微球偶联氨基化合物及其效果分析

琼脂微球表面偶联了氨基这一易被氧化的亲和性基团,制备了对口蹄疫病毒抗原的亲和作用。以琼脂微球为基质,通过正交试验筛选、凯氏定氮法测定,选取最优偶联条件下的琼脂微球介质,用其亲和吸附口蹄疫病毒灭活抗原,检测其亲和吸附效果。结果显示:琼脂微球15g,环氧氯丙烷15mL,3 M NaOH 30mL,40℃活化反应3.5h;6mL苯乙胺,2M NaOH 20mL,50℃偶联反应2.5h。该条件偶联后的含氮量是0.4486%,得到的该介质对口蹄疫灭活病毒抗原的层析效果和某生产疫苗的药厂的分离纯化效果相似,表明该自制介质对分离纯化口蹄疫灭活病毒抗原具有一定的应用潜力。     

环氧基化磁性微球的制备及表征

采用反相聚合包埋技术制备以Fe3O4为磁核,琼脂糖为壳层的琼脂糖磁性微球,用环氧氯丙烷对其进行表面化学修饰后制得环氧基化磁性微球.通过傅里叶变换红外光谱、热重分析和振动样品磁力测定等表征其结构和性质,采用酶联免疫吸附试验检测其对乙肝表面抗原的固定能力.结果表明,环氧基化磁性微球平均粒径为30.3μm,环氧基含量为140.19μmol·g-1,磁含量为50.53%,饱和磁化强度为11.25emu·g-1,对乙肝表面抗原的固定能力明显高于琼脂糖磁性微球,具有良好的单分散性、超顺磁性和生物兼容性,可作为筛选乙肝表面抗原特异性核酸适配体的载体.     

Fe_3O_4-果胶磁性微球的制备及对Cu~(2+)的吸附性能

用天然存在且吸附能力较强的果胶包覆具有磁性的四氧化三铁纳米颗粒制备一种吸附剂-Fe3O4果胶磁性微球.通过红外光谱、扫描电镜对样品进行表征,并考察吸附时间、Cu2+的质量浓度、吸附剂用量和吸附溶液的pH值对果胶磁性微球吸附溶液中Cu2+量的影响.结果表明,果胶磁性微球对铜离子的吸附主要发生在最初的1.5 h内,通过1.5 h的吸附后,吸附反应慢慢达到平衡,果胶磁性微球的平衡吸附量为72.50 mg/g.     

免疫磁珠的制备及其在捕获乳腺癌患者白细胞中的应用

应用生物素-亲和素系统制备免疫磁珠,考察了不同条件对制备免疫磁珠的影响.结果表明:当反应温度为4℃、亲和素浓度为0.2mg/mL、PBS pH=5.8、反应时间为2h时,磁性微球的亲和素载量为25~55mg/g;BNHS与抗体质量比1∶7时,生物素与抗体的结合率最高;亲和素与生物素化抗体摩尔比在1∶3时,亲和素与生物素的偶联率最高.抗CD45免疫磁性微球的白细胞去除率高达78%,磁珠回收率达98%,可用于进一步捕获乳腺癌外周血循环肿瘤细胞.     

纯化组氨酸标签蛋白金属螯合亲和色谱填料的制备与性能

以琼脂糖（agarose）凝胶的珠状产品SepharoseC1—6B为基质，以环氧氯丙烷为活化剂，将天冬氨酸固定在琼脂糖凝胶微球上，在经与溴乙酸修饰后，最终得到含有羧甲基天冬氨酸结构的琼脂糖凝胶微球，以凝胶微球负载的多羧基为配体分别与Co^2＋及Ni^2＋配位分别得到两种金属螯合亲和层析介质．依照上述方法制备了具有不同负载羧基含量的色谱介质，以六聚组氨酸融合蛋白为分离样品，研究了所制备的色谱分离介质的分离纯化性能，并与商品化色谱分离介质Agarose—NTANi进行了比较．结果表明，目标介质蛋白结合容量大，与蛋白结合快、易洗脱、选择性高，金属离子不易脱落。     

超顺磁性Fe3O4空心亚微球固定脂肪酶的研究

采用溶剂热法合成磁性亚微米球，并且利用扫描电镜、透射电镜、傅里叶红外光谱仪、X-射线衍射仪、振动样品磁强计等对合成样品进行了分析表征，结果表明所获样品为平均粒径为350nm的超顺磁性Fe₃O₄空心亚微球。对该样品进行了SiO₂包覆或氨基硅烷修饰，分别将Fe₃O₄空心亚微球、SiO₂包覆Fe₃O₄空心亚微球和氨基功能化Fe₃O₄空心亚微球作为固定化载体进行脂肪酶固定化。研究表明Fe₃O₄空心亚微球经SiO₂包覆或氨基功能化后对脂肪酶的固载量分别提高3.2和4.0倍，固定化酶比活力提高2.9和3.4倍。固定化的最优条件为pH6、25℃的条件下固定22h。     

镍离子亲和层析介质的制备及其用于组氨酸标记蛋白质的纯化

以交联琼脂糖微球为基质,通过环氧氯丙烷活化,偶联亚胺二乙酸并螯合Ni2+,制备得到一种镍离子亲和层析介质.结果发现,在强碱条件下环氧活化率达到了38.0 μmol/mL,最终Ni2+配基密度达到了30.9 μmol/mL,偶联效率为81.3%.利用得到的镍离子亲和介质对基因工程大肠杆菌表达的组氨酸标记3-羟基丁酮还原酶进行了一步层析纯化,酶活回收率达到了58.8%,纯化倍数为2.1,蛋白纯度在85%左右,纯化效果与常用商品介质基本相当.     

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…     

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。     

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     

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

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.