二去水卫矛醇对四种肿瘤细胞的体外抑制作用

采用噻唑蓝(MTT)比色法检测不同浓度二去水卫矛醇(DAG)对人胃癌细胞SGC-7901、人肺癌细胞H460、人鼻咽癌细胞CNE和人肝癌细胞BEL-7404的抑制率研究DAT对4种肿瘤细胞的体外抑制作用.结果表明,DAG对4种癌细胞:CNE、H460、SGC-7901和BEL-7404有较强的抑制作用,作用72h后半数抑制浓度(72h-IC50)分别为4.12μg· ml-1,15.98μg·ml-1,16.00μg· ml-1和16.73μg·ml-1.显微镜下可见经药物作用后细胞圆缩、胞质浓缩、胞浆内颗粒集中边缘化甚至细胞溶解等损伤现象.DAG在体外对上述4种癌细胞有明显的抑制生长作用.     

红树植物卤蕨地上部分提取物的生物活性初报

【目的】研究红树植物卤蕨(Acrostichum aureum)地上部分的乙醇提取物及其不同极性部位萃取物对我国3种高发性肿瘤细胞株(MCF-7,A549,HepG2)和3种微生物菌株(金黄色葡萄球菌Staphyloccocus aureus Rosenbach、大肠杆菌Escherichia coli、痤疮丙酸杆菌Propionibacterium acnes)的生长抑制作用。【方法】采用MTT法测定其对所选3种人肿瘤细胞株的细胞毒活性;采用改良的刃天青显色法,测定对3种微生物菌株的体外抗菌作用的最低抑菌浓度(MIC)。【结果】卤蕨地上部分的不同极性部位提取物对所选人肿瘤细胞株和微生物菌株表现出不同程度的生长抑制作用,其中乙酸乙酯萃取部位对3种细胞株具有很好的细胞毒活性,IC50值均低于20μg/mL,对金黄色葡萄球菌、大肠杆菌和痤疮丙酸杆菌的MIC分别为125μg/mL、125μg/mL、62.5μg/mL;正丁醇萃取部位的细胞毒活性和抑菌作用次之;石油醚萃取部位和水层对所选细胞株和菌株几乎不表现抑制作用。【结论】卤蕨地上部分乙醇提取物的乙酸乙酯萃取部位具有较好的细胞毒活性和抑菌作用,值得进行进一步活性追踪、分离纯化,以期获得具有药用价值的活性先导化合物。     

新型植物来源生物碱——唐松草阿原碱对人体肿瘤细胞株的细胞毒性研究

研究从毛莨科唐松草属植物尖叶唐松草根部提取的新型醚键双生物碱－唐松草阿原碱对几种人体肿瘤细胞株的毒性作用。唐松草阿原碱以质量浓度从2．5μg/mL到100μg/mL作用于6种体外培养的肿瘤细胞株及2种正常细胞株,对其中4个肿瘤细胞株种表现了强烈的杀伤作用。IC50分别为：宫颈癌Hela37 μg/mL,肝癌LCC60μg/ml,胃癌MGC65μg/mL,非小细胞肺癌PLA－80182μg/mL,对2个正常细胞株的毒性分别为：肝细胞L－0265μg/mL,小鼠成纤维细胞NIH3T378μg/mL,而对另一株肝癌HepG2及乳腺癌细胞MCF－7无明显作用（IC50＞100μg/mL）。     

两种甘草次酸哌嗪衍生物对Hela细胞增殖的抑制作用

研究甘草次酸哌嗪衍生物10c,11c对Hela细胞增殖的抑制作用.用MTT法观察10c,11c对Hela细胞增殖的影响.结果表明,10c,11c对Hela细胞均有抑制作用,10c,11c作用72h的半数抑制质量浓度分别为20.671,15.583μg/mL,且呈浓度依赖性.经单因素方差分析,同一时间内各组光密度、生长抑制率与对照组相比差异均有统计学意义(P<0.05).甘草次酸哌嗪类衍生物10c,11c对Hela细胞有明显的抑制作用.     

海洋真菌抗肿瘤活性菌株的筛选

采用MTT法,对从厦门海域红树植物、晒盐场土壤、海藻和海洋沉积物样品中分离到的231株海洋真菌的体外抗肿瘤活性进行筛选. 结果显示,有24株菌具有体外抗肿瘤活性,占总供测菌株的10.4%,其中对HeLa细胞有抑制作用的有15株,对HepG-2细胞有抑制作用的菌株有8株,对BGC细胞有抑制作用的菌株有12株. 选择对肿瘤细胞具有较强抑制作用的10株菌株进一步测定其培养物提取物对HeLa细胞的半数抑制浓度(IC50),发现JSSa-2,JQGa-6f和hzl02a-1株菌的活性很强, IC50分别为0.38,0.18,0.29 μg/mL. 实验结果表明,海洋真菌是潜在的抗肿瘤药物资源.     

硫酸长春新碱对肝癌细胞HepG2抑制作用

通过体外实验观察长春新碱对人体肝癌细胞增殖的影响效果.通过MTT比色法检测药物在不同时间和不同质量浓度条件下对细胞增殖的抑制作用.结果显示,24、48 h作用效果不理想,在72 h从质量浓度0.031 25μg/mL开始的长春新碱能造成对人体肝癌细胞HepG2增殖的抑制作用,达到8μg/mL时抑制效果基本达到最大.实验表明,长春新碱对人体肝癌细胞的增殖有比较明显的抑制作用,是一种效果较高,毒性较低,需要作用时间较长的化疗药.     

东方蝼蛄提取物对3株人宫颈癌细胞的细胞毒性研究

采用乙醇冷浸法对东方蝼蛄的干燥品粉碎物进行提取,采用聚酰胺柱层析分离划段得到东方蝼蛄乙醇提取物的不同部位,所得部位通过四甲基偶氮唑盐微量酶反应比色法(MTT法)对3种人宫颈癌细胞株(He La、Caski、C-33A)进行了体外肿瘤细胞毒性测试.结果表明,东方蝼蛄提取物中有1个分离样品的半数抑制浓度(IC50)接近10.0μg/mL,对3种人宫颈癌细胞株均具有明显的细胞毒性.东方蝼蛄乙醇提取物中存在抑制肿瘤细胞生长的物质,值得对其进一步深入研究.     

中药复方板蓝根颗粒抗柯萨奇B_4病毒作用的实验研究

采用中药复方板蓝根颗粒进行了体外抗柯萨奇病毒B4(CVB4)的研究,通过观察病毒引起的细胞病变效应(CPE)、MTT法检测细胞活性,作为考核药物抗病毒作用.结果表明:中药复方板蓝根颗粒对CVB4无直接灭活作用,但能抑制CVB4在Hep-2细胞内的的生物合成和阻止CVB4的吸附,其半数抑制浓度(IC50)分别为1129.00和1130.44μg/mL,治疗指数(TI)均为2.78.在100～1600μg/mL范围内复方板蓝根颗粒与CVB4抑制率呈明显的量效关系(P<0.01),在1600μg/mL时能抑制CVB4在Hep-2细胞内的增殖>50%.研究表明中药复方板蓝根颗粒能有效地抑制CVB4在Hep-2细胞中的增殖,其抗病毒作用发生在阻断病毒吸附细胞和抑制病毒进入细胞之后的复制增殖.     

白背叶黄酮化合物QB3对人肿瘤细胞增殖的抑制作用

为研究白背叶黄酮化合物QB3(芹菜素-7-O-β-D-(6″-反式-对-香豆酰基)-葡萄糖苷)对人肿瘤细胞增殖的抑制作用,采用四氮唑盐还原法(MTT)评价QB3体外对卵巢癌Skov3、Cne—2 z细胞增殖的影响。结果QB3在浓度为25、50μg/mL时对卵巢癌Skov3细胞有明显的抑制作用(P<0.05),其IC50为167.79μg/mL;QB3在浓度为50μg/mL时对Cne—2 z细胞有明显的抑制作用(P<0.05),其IC50为126.63μg/mL。说明QB3对Skov3、Cne—2 z细胞增殖有明显抑制作用。     

小月柳珊瑚中生物碱类化学成分及其抗骨肉瘤细胞增殖活性研究

【目的】研究小月柳珊瑚(Menella kanisa)中生物碱类化学成分及其抗骨肉瘤细胞增殖活性。【方法】采用多种分离方法和波谱分析方法,对小月柳珊瑚中生物碱类化学成分进行分离和结构鉴定。采用MTT法测试部分生物碱类化合物抗骨肉瘤细胞U2OS增殖活性。【结果】从小月柳珊瑚中分离出7个化合物,分别鉴定为6-(1′-purine-6′,8′-dionyl)suberosanone(1)、1-(3′-carbonylbutyl)purine-6,8-dione(2)、腺嘌呤脱氧核苷(3)、次黄嘌呤(4)、7-甲基腺嘌呤(5)、胸腺嘧啶脱氧核苷(6)、尿嘧啶脱氧核苷(7)。化合物1和2对骨肉瘤细胞U2OS增殖显示出抑制活性,IC50值分别为13.3μg/mL和55.0μg/mL。【结论】化合物1~7均首次从小月柳珊瑚中分离得到,其中化合物1和2的抗骨肉瘤细胞活性也为首次报道。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

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.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the