纳米银对体外培养细胞附着形态及膜功能的影响

通过研究纳米银的急性细胞毒性及其对体外培养的人脐静脉内皮细胞(HUVEC)和人脐动脉平滑肌细胞(HUASMC)附着形态、膜流动性和膜完整性的影响,初步探讨了纳米银的生物安全性.实验结果表明:浓度为0.003 9~0.5mg/mL的纳米银没有急性细胞毒性,但会影响细胞的附着形态,使细胞变小变圆,附着性变差;纳米银聚集沉积在细胞膜周围,影响细胞膜的流动性和细胞膜的完整性,从而产生一定的细胞毒性.     

磁场对酿酒酵母微观结构及膜脂流动性的影响

以磁场为外加物理场,采用恒定磁场及循环磁处理方式对酿酒酵母进行处理,研究酿酒酵母微观结构及细胞膜流动性的变化.通过透射电子显微镜观察不同磁感应强度恒定磁场处理后酿酒酵母的微观结构.研究发现恒定磁场可以促进酵母细胞的生长,群体中以具有中央大液泡为特征的成熟细胞所占比率增大,同时线粒体呈现适应性膨大、增生.利用原子力显微镜观察循环磁处理下酵母细胞的三维结构,发现细胞壁表面出现皱缩、穿孔,胞质外流.用荧光偏振法对两种处理方式下细胞的膜脂流动性进行测定,发现不同强度恒定磁场处理后,膜脂各向异性下降,流动性增强,0.05T磁感应强度下各向异性值下降3.57%,而循环磁处理后各向异性值比对照提高了8.46%,膜脂流动减慢,证实细胞膜为受到磁场作用的亚细胞结构.     

超声激活血卟啉对S180肿瘤细胞膜脂的影响

通过应用TBA法、比色法和荧光偏振法研究腹水型S180细胞在超声激活血卟啉处理后膜脂质过氧化程度,游离脂肪酸含量和膜流动性,探讨声动力疗法对腹水瘤膜脂结构和功能的作用以及声动力抑癌作用的生物学机制.研究结果显示,单纯超声可使肿瘤细胞膜脂质过氧化,磷脂降解而降低膜流动性.超声结合血卟啉显著增强单纯超声的作用,单纯血卟啉无作用.声动力疗法处理后,膜流动性的下降与脂质过氧化和磷脂降解呈显著相关,且与磷脂降解关系更为密切.分析得出,声动力疗法能使肿瘤细胞膜脂质过氧化程度明显升高,磷脂降解加剧,显著降低膜流动性,从而影响细胞正常代谢,抑制肿瘤细胞的恶性增殖.     

人红细胞老化对膜结构及组分的影响

目前认为细胞老化与其膜结构及组分的改变有密切关系。本文探讨了在不同条件下老化(体内或体外)的红细胞对其膜结构和组分的影响。结果表明,完整红细胞老化后其膜流动性均明显下降(P<0.01)而收缩蛋白含量显著增加(P<0.01)。但值得注意的是,分离的红细胞膜在体外老化(37℃,24小时)后收缩蛋白含量却显著减少(P<0.05)。关于老化红细胞膜上收缩蛋白含量变化的原因,本文作了初步讨论。     

人红细胞老化对膜结构及组分的影响

目前认为细胞老化与其膜结构及组分的改变有密切关系。本文探讨了在不同条件下老化(体内或体外)的红细胞对其膜结构和组分的影响。结果表明,完整红细胞老化后其膜流动性均明显下降(P<0.01)而收缩蛋白含量显著增加(P<0.01)。但值得注意的是,分离的红细胞膜在体外老化(37℃,24小时)后收缩蛋白含量却显著减少(P<0.05)。关于老化红细胞膜上收缩蛋白含量变化的原因,本文作了初步讨论。     

大金发藓乙酸乙酯提取物对K562细胞膜的损伤效应

为了探讨大金发藓乙酸乙酯提取物(PC-EEF)对K562细胞的膜损伤效应,应用MTT法检测PC-EEF对多种肿瘤细胞的细胞毒活性,台盼蓝拒染实验检测细胞存活力,相差显微镜观察K562细胞形态的变化,FDA-PI双染检测细胞膜通透性变化,DiBAC4(3)染色检测细胞膜电位变化,Hoechst33342-PI双染进一步验证细胞死亡的发生。研究结果显示:PC-EEF能显著地杀伤多种肿瘤细胞,其中对K562细胞最为敏感,PC-EEF以时间和剂量依赖性的方式降低K562细胞存活力。PC-EEF可诱导K562细胞发生显著膜损伤效应,表现为膜形态改变、膜通透性增加和膜电位下降。     

磁场处理对酿酒酵母微观结构及细胞膜流动性的影响及作用机理.

摘要：以磁场为外加物理场,采用恒定磁场及循环磁处理方式对酿酒酵母进行磁处理,研究酿酒酵母微观结构及细胞膜流动性的变化。通过透射电子显微镜,观察不同磁感应强度恒定磁场处理后酿酒酵母的微观结构,发现恒定磁场可以促进酵母细胞的生长,群体中以具有中央大液泡为特征的成熟细胞所占比率增大,同时线粒体呈现适应性膨大、增生。以原子力显微镜观察循环磁处理下酵母细胞的三维结构,发现细胞壁表面出现皱缩、穿孔,胞质外流,证实循环磁处理具有脉冲磁场的特征,可产生瞬间高能作用于细胞,从而产生致死效果。用荧光偏振法对两种处理方式下细胞的膜脂流动性进行测定,发现不同强度恒定磁场处理后,膜脂各向异性下降,流动性增强,0.05T磁感应强度下各向异性值下降3.57%,而循环磁处理后各向异性值比对照提高了8.46%,膜脂流动减慢,证实细胞膜为磁场作用的一个靶点。     

卵泡膜细胞的胰岛素抵抗对其雄激素合成的影响以及胰岛素增敏剂的调控机制

为探索卵泡膜细胞人工诱导胰岛素抵抗后其雄激素合成的变化,以及胰岛素增敏剂曲格列酮、二甲双胍对胰岛素抵抗卵泡膜细胞的调控作用,采用猪卵巢内卵泡膜细胞进行体外培养,地塞米松诱导,构建胰岛素抵抗的细胞模型,用曲格列酮和二甲双胍分别处理模型细胞,检测培养液中葡萄糖和激素水平的变化以及胰岛素信号分子和雄激素合成关键酶的mRNA表达变化.结果表明:卵巢内卵泡膜细胞发生胰岛素抵抗后能明显增进其雄激素合成能力:曲格列酮、二甲双胍均能降低胰岛素抵抗的卵泡膜细胞的糖代谢异常和雄激素水平.     

虾青素通过线粒体抑制高糖诱导的HBZY-1细胞凋亡

为了探究虾青素是否能有效改善高糖诱导的HBZY-1细胞的凋亡及其抗凋亡的机制,本研究采用CCK8法测定了正常糖和高糖环境下,不同浓度的虾青素对HBZY-1细胞活力的影响,并运用相关试剂盒测试了细胞死活比例和细胞凋亡的变化,在光镜下观察了HBZY-1细胞形态的变化,使用JC-1探针在荧光显微镜下观察了HBZY-1细胞线粒体膜电位的变化,运用Western Blot技术检测了HBZY-1细胞中促细胞凋亡蛋白bax和抑制细胞凋亡蛋白bcl-2的表达水平,运用caspase 3/7活细胞荧光实时法检测了HBZY-1细胞中的caspase 3/7活性.结果表明:虾青素可有效逆转高糖引起的细胞活力降低,能抑制高糖引起的HBZY-1细胞凋亡和细胞形态异常,并能改善线粒体膜电位和影响参与调控HBZY-1细胞的凋亡相关蛋白.由此认为:虾青素可以通过影响线粒体膜电位来改善高糖引起的肾小球系膜细胞凋亡,其有可能成为改善糖尿病肾病的潜在药物.     

人角膜内皮细胞株的建立与组织工程人角膜内皮的体外重建

为了体外重建出可用于角膜移植的组织工程人角膜内皮(TE-HCE),本文从业已建立的非转染人角膜内皮(HCE)细胞系中筛选出单克隆细胞株(mcHCE),并以其为种子细胞对TE-HCE的体外重建进行了研究。经有限稀释法从非转染HCE细胞系筛选出了mcHCE细胞株,形态结构、染色体分析以及细胞连接蛋白和膜运输蛋白的检测结果显示,mcHCE2401单克隆细胞株细胞具有正常而稳定的形态、结构和二倍染色体核型,并能表达细胞连接蛋白和膜运输蛋白,具有TE-HCE种子细胞的理想特征。以mcHCE2401细胞为种子细胞、以去上皮层修饰羊膜(mdAM)为载体支架体外重建出了TE-HCE,形态结构鉴定结果显示,多角形mcHCE2401种子细胞在mdAM 上形成了连续、完整的细胞单层,在细胞之间以及细胞与mdAM之间均形成了广泛的细胞连接,单层细胞密度高达3602.22±45.22个／mm²(相当于0～3岁孩童HCE的细胞密度),所重建单层角膜内皮的形态结构与在体HCE高度近似。可见,本文成功建立了形态结构、核型以及功能蛋白表达正常的单克隆细胞株,并利用mcHCE2401细胞和mdAM在体外成功重建出了形态结构与与在体HCE高度近似的最“年轻”的TE-HCE,有望作为捐献角膜内皮的等效替代物用于角膜内皮异常疾病的临床治疗。     

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.