伊维菌素对斑腿泛树蛙蝌蚪的遗传毒性

为了评价伊维菌素对斑腿泛树蛙蝌蚪遗传毒性的影响,采用碱性单细胞凝胶电泳的方法 (SCGE)检测在不同质量浓度伊维菌素溶液(0.000 5,0.004 0,0.007 5,0.011 0,0.014 5 mg·L-1)中处理48 h和96 h后斑腿泛树蛙蝌蚪血红细胞DNA的损伤情况.结果表明,在实验室条件下,随着伊维菌素质量浓度的增加和染毒时间的延长,蝌蚪血红细胞的DNA损伤率和DNA的总体损伤程度随之增加.在质量浓度为0.000 5 mg·L-1的伊维菌素溶液中处理48 h后,蝌蚪血红细胞的DNA损伤率出现极显著的提高;当伊维菌素的质量浓度达到0.007 5 mg·L-1时,蝌蚪血红细胞的DNA损伤率和DNA总体损伤程度均出现极显著的提高;在同一处理时间内,伊维菌素质量浓度与DNA总体损伤程度之间存在剂量效应关系.研究表明,伊维菌素对两栖动物蝌蚪具有一定的遗传毒性作用,存在着影响水生态平衡的风险.     

黄参多糖对四氧嘧啶损伤胰岛细胞的保护作用

以离体培养的大鼠胰岛β细胞为研究对象,探讨黄参多糖的降血糖作用及可能机制。用四氧嘧啶损伤胰岛细胞建立糖尿病损伤模型,以不同浓度的黄参多糖作用于四氧嘧啶损伤的胰岛细胞,用MTT法测细胞存活率;放射免疫法检测葡萄糖刺激性胰岛素分泌量的变化;用比色法检测胰岛细胞超氧化物歧化酶(SOD)、丙二醛(MDA)指标的变化。结果表明黄参多糖可以减少四氧嘧啶对胰岛细胞的损伤,增加细胞存活率;在2.8mmol·L-1、16.7mmol·L-1葡萄糖刺激下,黄参多糖剂量依赖性地促进了胰岛素分泌;黄参多糖能使胰岛细胞的MDA含量减少,同时增强了SOD的活性。总之,一定浓度范围的黄参多糖对损伤胰岛细胞的保护作用可能与黄参多糖能够增加细胞清除自由基能力,提高细胞存活率,促进胰岛素分泌量有关。     

翘鳞肉齿菌多糖的分离纯化及抗氧化活性的研究

为了分离纯化翘鳞肉齿菌多糖,解析其结构特征,并研究其抗氧化活性.运用DEAE-cellulose column进行柱层析分离纯化翘鳞肉齿菌多糖,高效凝胶渗透色谱(HPGPC)方法研究其均重分子量,通过红外光谱解析其结构特征,进一步研究其对羟基自由基(·OH)、1,1-二苯基-2-苦基肼自由基(DPPH-)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS+)的清除作用,同时研究了翘鳞肉齿菌多糖在H2O2作用下对PC12细胞的保护能力.其结果显示从四川省小金县翘鳞肉齿菌子实体分离纯化得到一种水溶性杂多糖(SIKP-1)纯品,其重均分量约为2.0×104 Da.通过化学方法研究了不同质量浓度的翘鳞肉齿菌多糖(SIKP-1)抗氧化活性,结果表明:当SIKP-1质量浓度为0.1mg/mL时,其对DPPH-自由基的清除率可达到40.63%;当SIKP-1质量浓度达到0.32mg/mL时,对·OH自由基的清除率可达到51.61%;当SIKP-1的质量浓度为3mg/mL时,对ABTS+自由基的清除率可达69.75%;在细胞生物学实验中,结果显示在用终质量浓度为0.5,1,2 mg/mL的SIKP-1处理下,PC12能免于H2O2的损伤,随着剂量的增加其存活率越高,分别为15.89%,27.60%,29.36%.综上试验结果显示,翘鳞肉齿菌多糖(SIKP-1)具有显著的抗氧化功能,因此可以作为一种理想的抗氧化剂资源.     

黄连素抗氧化活性的研究

采用MDA测定、琼脂糖凝胶电泳和SDS-PAGE法,检测了黄连素对由自由基引起的脂质过氧化、DNA断裂、蛋白质氧化降解的保护作用;用DMPD·+法检测了黄连素对DMPD·+自由基的清除能力.研究结果表明,黄连素有很好的抗氧化活性,并且随着浓度的升高,对脂质过氧化、DNA断裂、蛋白质氧化降解的保护作用和清除DMPD·+的能力逐渐增强.在抑制脂质过氧化中,当浓度为320 μmol·L-1时,抑制率达到95.5%.在保护DNA的氧化性损伤中,浓度为80 μmol·L-1时,具有明显的保护作用.在保护蛋白质氧化降解中,浓度达320 μmol·L-1时,保护作用明显.但对DMPD·+的清除能力较弱.当浓度为80 μmol·L-1时,清除率为1.7%.说明黄连素在不同的抗氧化体系中抗氧化活性不同.     

罗非鱼鱼鳞胶原多肽的优化制备及其生物活性研究

以罗非鱼鱼鳞为原料,采用碱性蛋白酶和胰蛋白酶复合水解,在单因素试验的基础上,采用响应面法优化酶解工艺,制备鱼鳞胶原多肽.测定胶原多肽的抗氧化活性、细菌低温保护活性、氨基酸组成及相对分子质量分布.结果显示,最适酶解条件为:底物质量浓度30.6 mg·m L-1、胰蛋白酶和碱性蛋白的加酶量分别为1.44和0.70 mg·m L-1、酶解温度50℃、pH值8.5、酶解时间6.35 h.酶解胶原多肽对DPPH自由基和羟基自由基的半数清除质量浓度(IC50)分别为2.89和3.54 mg·m L-1.经过细菌低温保护试验,当胶原多肽质量浓度为1 mg·m L-1时,嗜热链球菌的存活率达到75.6%.鱼鳞胶原肽相对分子质量分布显示,78%多肽片段的相对分子质量分布于180~2 000 u之间.氨基酸组成分析显示鱼鳞多肽富含甘氨酸、丙氨酸、脯氨酸、羟脯氨酸及天冬氨酸等,这些特定的氨基酸与胶原多肽的抗氧化活性、细菌低温保护活性相关.     

融合蛋白PTD-SOD对紫外辐射引起的细胞损伤的保护作用

采用MTT法、琼脂糖电泳以及测定细胞内抗氧化指标的方法研究融合型超氧化物歧化酶PTD-SOD对UVB照射引起的L-02细胞损伤的保护和修复作用.细胞存活实验表明,辐射时间为45 min,SOD活力为1 200U·mL-1时,在PTD-SOD保护和恢复作用下的细胞存活率可达94.0%和82.5%,而野生型SOD作用下的细胞存活率仅为68.2%和54.1%,与正常对照组相近.琼脂糖电泳结果显示,PTD-SOD能有效降低辐射对L-02细胞DNA的损伤程度.酶法检测细胞内的抗氧化指标时发现,PTD-SOD能有效地提高细胞内SOD活性,同时检测到细胞内过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-PX)活力的增加.相对野生型SOD,融合蛋白PTD-SOD对UVB辐射下L-02细胞的保护和恢复能力得到了显著的增强,具有作为防治UVB损伤药物的潜力.     

急性氨氮胁迫对大口黑鲈幼鱼ACP、CAT和MDA的影响

采用96 h静水停食实验法,以体质量为(19.70±1.98) g的大口黑鲈幼鱼为研究对象,研究了氨氮的96 h半致死浓度(LC50)并依据96 h LC50设置低(19 mg·L-1)、中(28.5 mg·L-1)、高(38 mg·L-1)和对照4个浓度组进行胁迫,在6、12、24、48、72和96 h时分别检测其鳃、肝、肠、肾和脑组织中的酸性磷酸酶(ACP)、过氧化氢酶(CAT)活性及丙二醛(MDA)的含量。结果表明:ACP、CAT(除肠部)活性及MDA含量在96 h实验时间段内总体上均呈现先升高后逐渐降低的变化趋势,均与对照组有显著变化(P0.05)。大口黑鲈幼鱼的96 h LC50为63.34 mg·L-1,但当氨氮浓度28.5 mg·L-1时经96 h胁迫其部分组织细胞功能已受到损伤,其鳃ACP活性和鳃、肠CAT活性能够准确反映所受损伤的程度,可作为评价养殖水体中氨氮毒性的标志物。     

不同浓度铁离子对栅藻生理生化特性和生长的影响

研究了不同浓度铁离子对栅藻生长和藻细胞抗氧化系统的影响.分析测定了培养基初始Fe3+分别为0,1.2×10-3,1.2×10-4,1.2 ×10-5,1.2×10-6,1.2×10-7 mol·L-1时栅藻的细胞密度、生物量、蛋白质含量、总脂产量及脂肪酸组成,并研究了不同浓度铁离子对栅藻细胞的抗氧化系统的影响.实验结果表明,当培养基中初始铁离子浓度为1.2×10-4 mol·L-1时最适合栅藻生长和蛋白质合成,蛋白质含量达到最大为97.33 μg·mL-1;当初始Fe3+浓度为1.2 ×10-5 mol·L-1时,栅藻细胞总脂占干质量最高达38.60％;C18∶ 2和C18∶3占总脂肪酸的比例随Fe3+浓度增加而降低.当Fe3+浓度达到1.2×10-3 mol·L-1时,栅藻的生长受到抑制.与对照组(培养基不添加铁离子)相比,不同浓度铁离子使栅藻总抗氧化能力增加,超氧化物歧化酶(SOD)活性和谷胱甘肽过氧化物酶(GSH-Px)活性有不同程度的提高,羟自由基能力受到不同程度的抑制.     

改性沸石处理氨氮废水实验研究

研究经NaCl溶液-焙烧改性后的沸石对废水中氨氮的去除效果.实验结果表明,当NaCl溶液质量浓度为70g·L-1,焙烧温度为300℃时可获得性能最佳的改性沸石;当氨氮废水溶液pH值为4～8、改性沸石投加量为1g、搅拌时间为30min时,对50mL浓度为100mg·L-1的废水的氨氮去除率可达92%以上.氨氮吸附等温线较...     

三叶青根多糖对HepG2细胞增殖、凋亡、迁移和侵袭的影响

目的:探讨三叶青根多糖(RTP)对肝癌细胞HepG2增殖、凋亡、迁移和侵袭的影响及其机制.方法:不同质量浓度(0.65、1.25、2.5、5、7.5、10 mg/mL)的RTP作用于肝细胞L-02不同时间(24、48和72 h),MTT法检测细胞增殖,筛选出对肝细胞L-02无毒性的RTP质量浓度.对肝细胞L-02无毒性质量浓度的RTP作用于HepG2细胞24、48和72 h后,MTT法检测细胞增殖,筛选出RTP对HepG2细胞的最佳作用质量浓度和时间.最佳质量浓度的RTP干预HepG2细胞一定时间(最佳作用时间)后,流式细胞仪检测细胞凋亡,Transwell检测细胞迁移和侵袭,qRT-PCR法和Western Blot法分别检测细胞中P21、Cyclin D1、Bcl-2、Bax、E-cadherin和MMP-2的mRNA和蛋白表达水平,qRT-PCR检测细胞中miR-151表达水平.转染miR-151抑制剂抑制HepG2细胞中miR-151表达,检测抑制miR-151表达后HepG2细胞的增殖、凋亡、迁移和侵袭及细胞中P21、Cyclin D1、Bcl-2、Bax、E-cadherin和MMP-2的mRNA和蛋白表达情况.结果:低质量浓度(0.65、1.25、2.5 mg/mL)RTP对肝细胞L-02无毒性.RTP作用HepG2细胞的最佳作用质量浓度和时间分别为1.25 mg/mL、48 h,1.25 mg/mL的RTP及抑制miR-151表达均可降低HepG2细胞活性、迁移和侵袭细胞数及细胞中Cyclin D1、Bcl-2和MMP-2的mRNA和蛋白表达水平(P0.05),提高HepG2细胞凋亡率及细胞中P21、Bax和E-cadherin的mRNA和蛋白表达水平(P0.05).并且RTP可抑制HepG2细胞中miR-151表达.过表达miR-151且同时用1.25 mg/mL的RTP作用HepG2细胞时,细胞活性、迁移和侵袭数及细胞中Cyclin D1、Bcl-2和MMP-2的mRNA和蛋白表达水平升高(P0.05),细胞凋亡率及细胞中P21、Bax和E-cadherin的mRNA和蛋白表达水平降低(P0.05).结论:RTP可抑制肝癌HepG2细胞增殖、迁移和侵袭,并诱导其凋亡,其作用机制可能与下调miR-151表达有关.     

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.