田基黄提取物抑菌作用的研究

该实验以金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、青黄链霉菌、酿酒酵母菌、苏云金芽孢杆菌和变形杆菌为供试菌种,采用采用滤纸片扩散法对田基黄水提取液进行抑菌实验研究,并测定其最低抑菌浓度（MIC）,其结果表明：田基黄水提取物对供试菌种普遍有抑制作用,黑曲霉除外;MIC也因菌种不同而不同,金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌和青黄链霉菌为0.25g/mL,酿酒酵母菌为0.5g/mL,苏云金芽孢杆菌和变形杆菌均为0.125g/mL.实验还采用不同有机溶剂的提取物对选取的五种供试菌种进行抑菌作用研究,其结果表明：田基黄有机溶剂提取物对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、青黄链霉菌、苏云金芽孢杆菌均有抑制作用,且抑菌效果均比水提取物的抑菌效果明显.     

白花蛇舌草黄酮类化合物的提取及抑菌作用

[目的]测定在选定条件下白花蛇舌草(Hedyotis diffusa)的乙醇粗提物干膏得率及其中黄酮类化合物的含量,探讨粗提物和纯化后的黄酮类化合物的抑菌作用.[方法]将白花蛇舌草置于体积分数为70％的乙醇溶液中冷浸,对其中的黄酮类化合物进行粗提;再通过AB-8型大孔吸附树脂对粗提物进行处理,获得纯化后的黄酮类化合物.通过测定粗提物和纯化后的黄酮类化合物产生的抑菌圈直径比较两者对大肠杆菌(Escherichia coli)、枯草芽孢杆菌(Bacillus subtilis)和金黄色葡萄球菌(Staphylococcus aureus)的抑菌作用.[结果]粗提物干膏得率为10.34％,干膏中黄酮类化合物含量为9.73％,纯化后的黄酮类化合物得率为5.98％.粗提物对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌的最小抑菌浓度分别为3.125,1.562 5和50 mg·mL-1.纯化后的黄酮类化合物对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌的最小抑菌浓度分别为125,62.5和1 000μg·mL-1.[结论]白花蛇舌草乙醇提取物对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌均具有较强的抑菌作用,为新型食品防腐剂的开发提供了基础资料.     

新型胆酸缩氨基硫脲衍生物的合成与抗菌活性研究

通过甾酮与取代氨基硫脲缩合,合成了一系列新型的胆酸缩氨基硫脲衍生物.其结构均经1H NMR,IR,ESI-MS及元素分析所证实.此外,所有目标化合物都进行了对金黄色葡萄球菌,枯草芽孢杆菌,绿脓杆菌,大肠杆菌的抗菌活性测试.化合物4b,4g和4h对绿脓杆菌和大肠杆菌都具有良好的抑制效果.     

嗜酸乳杆菌生长状况及抑菌特性的研究

用MRS培养基培养嗜酸乳杆菌,测定其生长曲线,并以金黄色葡萄球菌和枯草芽孢杆菌为指示菌株,利用杯碟法检测嗜酸乳杆菌对大肠杆菌、金黄色葡萄球菌的抑菌作用。结果发现在37℃的恒温箱中培养24h后,通过测量抑菌圈大小,可得知嗜酸乳杆菌对金黄色葡萄球菌、枯草芽孢杆菌有明显的抑菌作用。     

海芦笋黄酮化合物抑菌效果研究

研究海芦笋黄酮化合物对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、沙门氏菌、副溶血弧菌的体外抑制效果。结果表明,海芦笋黄酮化合物对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌、沙门氏菌、副溶血弧菌的抑制效果良好,而抑菌效果为:大肠杆菌<沙门氏菌<枯草芽孢杆菌<副溶血弧菌<金黄色葡萄球菌。     

瑞香狼毒花多糖提取工艺优化及其抑菌活性研究

文章采用水提醇沉法,进行了单因素实验和正交实验,研究了瑞香狼毒花多糖的最优提取条件,并考察分析了瑞香狼毒花多糖对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌的抑制作用。结果表明:瑞香狼毒花多糖提取的最佳条件为料液比1:30(g/m L)、水浴温度85℃、浸提时间9h、微波功率240W;抑菌试验发现,瑞香狼毒花多糖对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌均有抑制作用,其对金黄色葡萄球菌和枯草芽孢杆菌的最小抑制浓度为12.5mg/m L,对大肠杆菌的最小抑制浓度为6.25mg/m L。     

薤白抑菌作用的初步研究

薤白抑菌作用的研究结果表明:每g鲜草1ml纯水浸提液对5ml培养液的供试菌株均有抑制作用;随着浸提液稀释倍数的增加其抑菌能力减弱,32倍稀释液仅对枯草杆菌和金黄色葡萄球菌有部分抑制能力;抑菌能力强弱存在菌间差异,依次为金黄色葡萄球菌>枯草芽孢杆菌>蜡状芽孢杆菌>大肠杆菌>绿脓杆菌>沙门氏菌.此外,薤白浸提物具有较好的热稳定性,其抑菌因子尚待进一步研究.     

云南琵琶甲化学成分的抑菌活性

采用平板稀释法测定了从昆虫云南琵琶甲中分离到的１０种化学成分对大肠 杆菌、绿脓杆菌,巨大芽孢杆菌、白色葡萄球菌、滕黄八叠球菌和枯草芽孢杆菌的抑菌作用。结果表明,化合物Ⅰ,Ⅱ,Ⅶ对大肠杆菌、对大大肠杆菌、巨大芽孢杆菌、白色葡萄球菌、腾黄八叠球菌和枯草芽孢杆菌有很强的抑菌活性,所有化合物对绿脓杆菌无抑菌活性。     

龙陵紫皮石斛花色苷色素抑菌作用初探

以龙陵紫皮石斛(Dendrobium devonianum)紫茎为试材,研究其色素的抑菌作用。用溶剂法提取花色苷,通过固体和液体培养基的试验方法,研究了龙陵紫皮石斛花色苷对大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphyloccocus aureus)、枯草芽孢杆菌(Bacillus subtilis)的抑菌作用。3种类型紫皮石斛花色苷对枯草芽孢杆菌抑菌作用较为显著,且抑菌作用与花色苷浓度呈正相关。抑菌作用大小为:枯草芽孢杆菌金黄色葡萄球菌大肠杆菌。     

红花羊蹄甲抑菌活性的研究

红花羊蹄甲花提取物对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌和土壤中的一些细菌均有抑菌效果,随着羊蹄甲花提取物浓度的增加,其对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌的抑茵作用增强,呈一定的剂量依赖性.在同等浓度下羊蹄甲花提取物对金黄色葡萄球菌的抑菌效果最好,抑菌圈可达13.0mm,其次是枯草芽孢杆菌,抑茵圈可达到9.0mm,然后是大肠杆菌,抑茵圈为7.4mm.最后找出羊蹄甲花对这些细菌的最低抑茵浓度.红花羊蹄甲花提取物对米曲霉、黑曲霉无抑菌效果.     

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.     

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.     

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.