刺参多糖对星形胶质细胞活化作用机制研究

目的探讨刺参多糖对星形胶质细胞的活化作用机制.方法选取新生Wistar大鼠24只,经胰酶消化分离可得星形胶质细胞;采用MTT法检测HS-4对细胞的毒副作用;采用伊红染色与免疫荧光染色检查细胞的形态学变化;采用Western blot法检测细胞特征蛋白GFAP和细胞周期调控蛋白Cyc DI的表达;采用BrdU法检测细胞的增殖;采用Transwell法检测细胞的迁移.结果 HS-4浓度在0.1～100μg/mL,作用时间为3,5 d时,细胞数量与对照组差异不显著,HS-4浓度在100μg/mL,作用时间为7 d时,细胞存活率明显低于对照组,差异显著;体外培养的细胞与HS-4单独作用,细胞形态无明显改变,HS-4与FGF-2联合作用后,细胞形态发生明显改变;星形胶质细胞的特征蛋白GFAP表达水平显著升高,HS-4在1μg/mL和5μg/mL时,GFAP表达升高了169%和183%;对照组细胞周期调控蛋白Cyc DI表达最低,FGF-2单独作用后,Cyc DI表达略有升高,当HS-4与FGF-2联合作用后,Cyc DI表达明显升高;对照组BrdU阳性率最低,占细胞总数的12.9%,FGF-2单独作用后,BrdU阳性率略有升高,占细胞总数的16.4%,与对照组差异不显著,HS-4浓度为1μg/mL和5μg/mL时与FGF-2联合作用,BrdU阳性率明显升高,占细胞总数的28.5%和56.1%,与对照组相比差异显著;静息状态星形胶质细胞无迁移,HS-4与FGF-2作用下星形胶质细胞迁移明显.结论 HS-4与FGF-2能有效诱导星形胶质细胞的活化,其活化机制主要是强化细胞增殖与迁移.     

龙葵碱诱导HepG2细胞凋亡的观察

观察龙葵碱对3种消化系统肿瘤细胞株人肝癌细胞HepG2、人胃癌细胞SGC-7901、人大肠癌细胞Ls-174的细胞毒作用.并从细胞凋亡角度揭示龙葵碱对敏感细胞株的作用机制.采用MTT法观察龙葵碱对3种肿瘤细胞株的细胞毒作用;采用AO/EB双染,激光共聚焦扫描显微术(confocal)观察龙葵碱对HepG2肿瘤细胞形态的影响;PI单染,流式细胞仪测定龙葵碱诱导HepG2细胞凋亡的凋亡率及对细胞周期的影响.龙葵碱作用于HepG2、SGC-7901、LS-174的IC50分别为14.47μg/mL、(50μg/mL、(50μg/mL;在形态学观察实验中,阴性对照组细胞形态正常,0.003 2μg/mL、0.016μg/mL龙葵碱使细胞外周呈微弱皱缩状改变,0.08、0.4、2μg/mL龙葵碱使HepG2细胞出现大量碎片及凋亡小体等典型的细胞凋亡形态.凋亡率测定结果表明5个剂量龙葵碱诱导HepG2细胞凋亡率分别为6.0%、14.4%、17.3%、18.9%、32.2%,0.08μg/mL喜树碱诱导HepG2细胞的凋亡率为21.9%.细胞周期观察发现龙葵碱各组G2/M期均消失,S期明显升高.龙葵碱对HepG2人肝癌细胞株比较敏感,能够诱导HepG2细胞凋亡,并将HepG2细胞阻止在S期,影响肿瘤细胞DNA合成.     

山楂活性成分对氧化低密度脂蛋白损伤人微血管内皮细胞的防治作用

对山楂中有效成分进行分离提取，并研究其保护人微血管内皮细胞（HMEC）抑制氧化低密度脂蛋白（oxLDL）损伤和对损伤的修复作用.对山楂石油醚和氯仿提取物，经过反复硅胶柱层析，分离得到3种化合物，经理化性质和波谱分析，鉴定为：（Ⅰ）胡萝卜苷（Daucosterol）、（Ⅱ）熊果酸（Ursolic acid）、（Ⅲ）β 谷甾醇（β sitosterol）.实验以山楂依次用石油醚、氯仿、乙酸乙酯、95％乙醇提取的各种提取物和化合物Ⅰ～Ⅲ为研究对象，以洛伐他汀（Lovastatin）作为阳性对照，MTT法考察样品对保护HMEC抑制oxLDL损伤和对损伤的修复作用.结果表明：山楂各种溶剂提取物和洛伐他汀在3.12～25 μg/mL时，保护细胞抑制氧化损伤；乙酸乙酯、95%乙醇提取物在浓度6.25～25 μg/mL时对氧化损伤细胞有修复作用，效果好于洛伐他汀；胡萝卜苷、β 谷甾醇在0.39～12.5μg/mL下有保护作用；熊果酸在0.39～1.56 μg/mL下有保护作用；胡萝卜苷在浓度6.25～12.5 μg/mL下表现出很强的修复作用，熊果酸在浓度0.39～3.12 μg/mL时表现出的修复作用和洛伐他汀相当.     

铁棍山药多糖对PC12及Hepa1-6细胞在体外增殖的影响

采取闪式提取法从铁棍山药中提取山药多糖,利用胰蛋白酶去除多糖中的杂蛋白,冷冻干燥获得山药多糖制品.分别以10μg/mL、100μg/mL、500μg/mL、1 000μg/mL浓度添加于生长良好的PC12及Hepa1-6细胞中,再分别二次培养12h、24h、36h,研究山药多糖在体外对PC12及Hepa1-6两种细胞增殖的影响.结果显示:在培养24h后,当山药多糖浓度为10μg/mL、100μg/mL时,对PC12细胞增殖的影响没有差异性(P>0.05),但当浓度进一步提高到500μg/mL、1 000μg/mL时,则对PC12细胞的增殖体现出显著影响(P<0.05);对于Hepa1-6,在培养12h且山药多糖浓度在10μg/mL、500μg/mL时,对Hepa1-6细胞增殖的影响差异性显著(P<0.05),同时在100μg/mL浓度下,山药多糖对Hepa1-6细胞的增殖抑制更加明显(P<0.01).但当浓度达到1 000μg/mL时,对Hepa1-6细胞增殖呈现促进作用.在培养24h时,各浓度的山药多糖对Hepa1-6细胞增殖的影响均没有差异性(P>0.05).当培养36h后,在山药多糖浓度为10μg/mL、100μg/mL、500μg/mL下,统计显示对Hepa1-6细胞增殖的影响差异性显著(P<0.05).上述结果说明,山药多糖在一定的浓度范围内具有明显的抗肿瘤作用.     

莪术醇对HNE1鼻咽癌细胞荷瘤鼠的抑瘤作用

目的考察研究莪术醇对HNE1鼻咽癌细胞荷瘤鼠的抑瘤作用。方法体外通过细胞划痕试验,考查莪术醇不同浓度(12.5μg/mL、25μg/mL、50μg/mL、100μg/mL)对HNE1鼻咽癌细胞迁移能力的影响,计算细胞迁移率(细胞迁移率(%)=(0 h划痕距离-12 h//24 h/48 h划痕距离)/0 h划痕距离×100%);体内采用HNE1鼻咽癌细胞接种裸鼠待长出实体瘤,将实体瘤移植裸鼠皮下建立HNE1鼻咽癌荷瘤鼠模型,用莪术醇分别给实验组裸鼠灌胃0.79 mg/10 g,对照组给灭菌蒸馏水,阳性组给予去氧氟尿苷,每日1次,连续30 d。每周测量体质量和肿瘤大小2次,第30天给药后处死小鼠,解剖称肿瘤质量,体积计算公式V=a×b×c×π/6,计算抑瘤率,评价莪术醇对HNE1鼻咽癌荷瘤鼠的抑制作用。结果与对照组比较,体外试验证明莪术醇100μg/mL对HNE1鼻咽癌细胞迁移性有统计学意义(P0.05),体内试验证明莪术醇组对HNE1鼻咽癌细胞荷瘤鼠肿瘤的抑制作用明显,抑瘤率为34.04%,肿瘤质量与对照组比较有统计学意义(P0.05),与对照组和去氧氟尿苷组比较,肝脏和脾脏系数均有统计学意义(P0.05),且与去氧氟尿苷组比较,肝脏系数有统计学意义(P0.05)。结论通过实验得出莪术醇能降低HNE1鼻咽癌细胞迁移能力并对荷瘤鼠肿瘤具有抑制作用,为莪术醇对肿瘤的抑制作用研究提供了实验基础。     

羟基喜树碱联合丝裂霉素诱导人白血病K562细胞凋亡

观察羟基喜树碱与丝裂霉索联合应用对人白血病细胞K562的作用效果,并探讨其机制。不同浓度羟基喜树碱与丝裂霉素单独及联合作用于人白血病细胞K562后,应用台盼蓝拒染法检测细胞生长抑制率,计算合用指数（CI）,流式细胞仪（FCM）检测K562细胞凋亡率,吖啶橙（AO）荧光染色和透射电镜观察凋亡形态学变化。结果表明：单独应用时羟基喜树碱和丝裂霉素的IC50分别是8μ/mL和12．5μg/mL,联合应用时IC50下降为4μg/mL（HCPT）和3．6μg/mL（MMC）,CI=0．78,为协同效应。羟基喜树碱与丝裂霉素单独及联合应用均可诱导K562细胞凋亡。2种药物联合应用时的凋亡率高于各自单独用药。羟基喜树碱与丝裂霉素联合应用可以通过共同诱导细胞凋亡。协同抑制人白血病细胞生长。     

西兰花中异硫氰酸盐诱导HepG-2凋亡的研究

探讨西兰花中异硫氰酸盐(isoth iocyanates,ITCS)诱导HepG-2细胞凋亡作用及其可能机制.用不同质量浓度ITCS处理肝癌HepG-2细胞,通过SRB法、细胞形态学观察、流式细胞仪和激光共聚焦显微镜实验,观察ITCS对HepG-2细胞的抑制率和细胞凋亡的影响.结果:1、10、50和150μg/mL的ITCS作用于HepG-2细胞72 h后,ITCS可抑制HepG-2细胞的增殖,其IC50为15.824μg/mL;120μg/mL的ITCS作用HepG-2细胞24 h后,细胞出现早期凋亡细胞的形态;60、120、240μg/mL的ITCS作用于HepG-2细胞48 h后,可见细胞凋亡率分别为(16.6±2.8)%、(21.9±4.4)%和(70.2±5.3)%;15、30、60μg/mL的ITCS作用于HepG-2细胞24 h后,细胞内的Ca2 质量浓度升高,且随着ITCS给药剂量的增加而升高(P<0.05).ITCS能够促进人肝癌细胞系HepG-2细胞的凋亡,其作用机制可能与ITCS升高细胞内Ca2 质量浓度有关.     

威灵仙不同提取部位对脂多糖诱导的RAW264.7细胞NO生成及iNOS和TNF-α表达的影响

研究了威灵仙不同提取部位对脂多糖(LPS)诱导的RAW264.7细胞NO生成及iNOS和TNF-α分泌的作用.通过ELISA方法检测25、50、100μg/mL的威灵仙不同提取部位对LPS(1μg/mL)诱导RAW264.7细胞产生NO、iNOS和TNF-α的影响;实时定量PCR方法检测威灵仙不同提取部位对LPS诱导iNOS和TNF-α基因表达的影响.结果表明,LPS能够明显诱导RAW264.7细胞产生NO、iNOS和TNF-α,威灵仙不同提取部位(25、50、100μg/mL)均能抑制其活性和基因表达,并呈现明显的剂量依赖性,其作用强弱依次为威灵仙乙酸乙酯部位、石油醚部位、正丁醇部位和水部位.因此得出,威灵仙不同提取部位的抗炎作用效果不同;抑制炎症因子的分泌和释放可能是威灵仙发挥抗炎作用机制之一.     

二氢卟吩e6光动力学疗法对食管癌Eca—109细胞增殖迁移的影响

研究了二氢卟吩e6(Ce6)介导的光动力学疗法(PDT)对体外食管癌Eca—109细胞增殖迁移的影响.通过MTT法检测了Ce6-PDT对食管癌Eca—109细胞增殖的作用,采用划痕实验探究了Ce6-PDT对Eca—109迁移的影响.结果表明:无光照条件下,低浓度Ce6各组与对照组相比无显著性差异(P>0.05),但Ce6质量浓度为1.0μg/mL时与对照组相比有显著性差异(P<0.05);Ce6-PDT对Eca—109细胞增殖的抑制作用在一定范围内与Ce6浓度、光照剂量、作用时间和孵育时间成正相关(P<0.05);Ce6-PDT对Eca—109细胞迁移能力的影响与未经处理的对照组比较作用不显著.可见Ce6-PDT能有效抑制Eca—109细胞的增殖,但Ce6-PDT对Eca—109迁移的作用不明显.     

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）。     

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