产生埃博霉素的纤维堆囊菌的分子筛选

为寻找潜在的产生埃博霉素(epothilone)的纤维堆囊菌(Sorangium cellulosum),以埃博霉素生物合成基因簇中的epoA,epoC和epoK基因为探针,分别对60株不同土壤样品来源的纤维堆囊菌的DNA样品进行PCR筛选.筛选结果得到了7株阳性菌株,进一步对其进行发酵和粗提物的HPLC-MS分析,检测结果显示3株菌XMU-Nc-03,XMU-So-64和XMU-So-112能产生埃博霉素B,其中XMU-So-112的产量最高.本实验在筛选产埃博霉素活性菌株的同时,还建立了一个快速可靠的发现埃博霉素产生菌的方法.     

对甲苯磺酸钠对埃博霉素产量的影响

为研究对甲苯磺酸钠(p-TSA-Na)对于埃博霉素产量的影响,探讨产量最佳时对苯磺酸钠的最优添加浓度和产量稳定性,分别向培养基内添加7个不同浓度的对甲苯磺酸钠溶液,进行发酵培养,以埃博霉素生物合成的产量为依据,确定最佳添加浓度、培养基体积、添加对甲苯磺酸钠浓度的范围。结果表明:对甲苯磺酸钠浓度在1~32 mmol/L范围内与埃博霉素生物合成产量均呈正相关关系,4~16 mmol/L范围内最明显,培养基内初始浓度达24 mmol/L时,对埃博霉素生物合成产量的促进作用最大,S-腺苷甲硫氨酸合成酶比活力增大22%~75%,说明对甲苯磺酸钠对埃博霉素生物合成产量的增大有促进作用。     

埃博霉素-菌蜕系统抑制肿瘤细胞增殖作用

利用大肠杆菌菌蜕搭载埃博霉素B(BG-Epo B),研究其对Hela细胞增殖的抑制作用,并且对搭载条件进行优化。MTT实验结果显示,BG-Epo B对Hela细胞的毒性作用显著大于游离埃博霉素B(Epo B,p0.05),IC50值为8.2 mg/L,透射电镜观察发现,BG-Epo B对Hela细胞的杀伤力增强。     

从腹泻实验兔分离的一株大肠埃希菌的生物学特性研究

目的 研究从腹泻实验兔分离到的大肠埃希菌的生物学特性。方法 对一株从因腹泻而死亡的SPF级实验兔体内分离的致病性大肠埃希菌的遗传谱系、抗生素敏感性、消毒液敏感性以及细菌携带的耐药基因和毒力基因进行较为全面的研究。结果 该大肠埃希菌属于B1型遗传谱系，携带毒力基因eaeA,属于肠致病性大肠埃希菌。对常用的5种消毒液敏感，对于青霉素、氨苄西林、头孢氨苄、头孢拉定、四环素、多西环素、米诺霉素、红霉素、麦迪霉素、万古霉素、复方新诺明等11种抗生素耐药，携带aadA1,gyrA,sul1和tetA等4个抗生素耐药基因。结论 从因腹泻而死亡的SPF级实验兔体内分离的致病性大肠埃希菌为一株B1型遗传谱系的肠致病性大肠埃希菌，具有多重耐药性，对常用的消毒剂均敏感。     

潜在益生菌鼠李糖乳杆菌在大豆奶酪中的稳定性

研究了鼠李糖乳杆菌Laetobacillus．rhamnosus 6013在MRS中的培养条件并评价了该菌在大豆奶酪加工过程中的稳定性．确定该菌的最佳培养条件为：37℃，厌氧培养48h，该条件下的培养上清液对金黄色葡萄球菌、枯草杆菌、沙门氏菌有良好的抑制作用．将大豆奶酪细菌DH1，GH4和该菌一起加到豆奶中，制成细菌型发酵大豆奶酪，在发酵6h后，该菌的活菌细胞数达10^8～10^9个／mL．在成熟30天后，pH值有轻微下降，该菌存活细胞数达10^7个/g，而DH1，GH4的活菌数均为10^6个／g．当盐水中NaCl含量为20—40g/L时，对L.rhamnosus 6013的存活影响很小．以上结果表明，潜在益生菌L．rhamnosus 6013能耐受大豆奶酪的加工过程，对大豆奶酪的发酵没有负面的影响．     

总状共头霉产生杀线虫活性物质的条件和产物性质的初步研究

研究了培养基组分和培养条件对Sr．菌产生杀线虫活性物质的影响，并经过发酵放大表明，该菌代谢产物具有很强的杀线虫活性。该菌的最适培养基配方为lL土豆汁(200g／L)中加入20g蔗糖，pH自然。最佳培养条件采用500mL三角瓶装量100mL，接种量2％，170r／min，26℃，培养4d，将发酵滤液稀释为原浓度的1／2，其杀线率达到80％；在5L发酵罐上进行放大试验，发酵(44—52)h，将发酵滤液稀释为原浓度的1／2，其杀线率稳定在95％以上。该活性代谢物热稳定性强，呈水溶性，经分离证实活性组分中包含有机酸类物质。     

绿汁发酵液及纤维素酶对菌糠发酵饲料品质的影响

对菌糠废料进行了固体发酵．试验设有添加绿汁发酵液（GFJ）、添加纤维素酶（CEL）和对照（CON）3个处理．常温下发酵50天开封，测定菌糠发酵饲料的化学成分和发酵品质，试验结果表明，添加绿汁发酵液显著地提高了菌糠发酵饲料的水溶性碳水化合物含量和千物质回收率（P〈0．05），极显著和显著地降低了pH值（P〈0．01）和水分、酸性洗涤纤维、氨态氮的含量（P〈0．05）．说明添加绿汁发酵液和添加纤维素酶对提高菌糠发酵饲料的品质均有效，特别是添加绿汁发酵液的效果更显著．     

微生态制剂发酵鸡粪与秸秆粉的效果分析

对自制微生态制剂发酵鸡粪与秸秆粉作为饲料的可行性做了初步探讨．结果表明,鸡粪与秸秆粉等比例混合后,加入0．5％以上的微生态制剂,在30℃下发酵10—15天,发酵料的pH稳定在4．0—4．5,并可有效抑制有害菌的生长,发酵料具有酒香味、适口性好,可代替部分日粮饲喂家畜。     

茶渣发酵菌株的筛选、鉴定及生物学分析

提取茶多酚后的废茶渣中富含茶蛋白和茶纤维，研究通过室内高温固态发酵废茶渣，旨在从中筛选废茶渣发酵微生物，并进行鉴定和相关生物学分析。结果表明，研究共筛选到废茶渣发酵微生物4株，C-1，C-2， C-3，C-4，经DNA提取，ITS扩增测序，NCBI数据库比对，4株菌株分别属于米曲霉，烟曲霉，镰刀菌，毛霉菌。生长曲线实验表明：毛霉菌在含有茶渣滤液的PDA平板上生长最快。     

BN-2调节剂对棉花产量及加工品质的影响

通过在棉花不同生长发育时期叶面喷施不同浓度BN—2调节剂，其结果：棉花现蕾期和开花期喷施有显著的增产效果，在2—4mg/kg浓度下，增产皮棉27．5—294．0kg/hm^2，增产效果显著；在适宜时期和浓度下叶面喷施BN—2，可在一定程度上提高棉花品质；跨长比CK增加0．1—0．8mm，纤维强度比CK增加0．3-1．5cN／tex，伸长率变化不大，马克隆值降低，纤维整齐度明显提高，棉花纤维手感明显改善．BN—2适宜使用时期为现营期到开花期，使用浓度为2—4mg/kg。     

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).     

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.     

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.