拉伸应变波形对人肺腺癌细胞A549粘弹性的影响

通过FX-4000柔性基底加载系统研究了不同波形的周期性拉伸应变对体外培养人肺腺癌A549细胞粘弹性的影响,采用微管吸吮技术考察A549细胞的粘弹性特性,将方波及正弦波作用下的A549细胞与对照组细胞粘弹性进行比较．选择三参数标准线性固体模型拟合实验结果,并用三个粘弹性系数比较各组A549细胞的力学性质．实验结果表明：与对照组比较,在胶原蛋白基底膜上,应变幅度15％,频率0．5Hz,加载时间4h,方波拉伸组A549细胞的粘弹性系数k1,k2和μ值均明显降低;正弦波拉伸组A549细胞的k1和k2值有所减小,μ值无明显差异．研究表明：方波拉伸后的A549细胞更容易变形,细胞刚性减小．     

机械拉伸对兔角膜成纤维细胞增殖和迁移的影响

对兔角膜成纤维细胞施加5%应变、0.1Hz的周期性机械拉伸,采用流式细胞仪检测细胞增殖情况,划痕法研究细胞迁移情况。结果发现,与静态对照组相比,5%机械拉伸能够使S期细胞数量明显增多;施加1ng/mL表皮生长因子(Epidermal growth factor,EGF)或100ng/mL碱性成纤维细胞生长因子(Basic fibroblast growth factor,bFGF)后细胞相对划痕宽度明显变小。与各自静态对照组相比,拉伸10h,单轴拉伸组相对划痕宽度明显增加,等双轴拉伸则无显著性差异;拉伸20h,无论是等双轴还是单轴拉伸,相对划痕宽度均明显增加;拉伸同时施加bFGF或EGF后相对划痕宽度均减小,与静态对照组相当。提示机械拉伸能够促进角膜成纤维细胞增殖,但抑制了细胞迁移行为,该抑制效应与拉伸作用方式有关;而bFGF和EGF则可以减弱牵拉引起的细胞迁移抑制效应。     

强力霉素对人非小细胞肺癌A549细胞的增殖抑制及促凋亡作用

为研究强力霉素体外对人非小细胞肺癌A549细胞的增殖及凋亡的影响。应用MTT比色法研究不同浓度强力霉素(2.5,5,10,20,50mg/L)对A549细胞增殖的影响。荧光显微镜、琼脂糖凝胶电泳、AnnexinV-PI双标法等多项方法,研究强力霉素对A549细胞的促凋亡作用;采用免疫组化的方法,观察药物作用后bcl-2和bax的表达。强力霉素作用后,A549细胞的吸光度值降低,并出现凋亡特有的细胞核改变DNA梯状条带,早期凋亡的细胞数增加,伴有bcl-2的下调,bax上调。这表明强力霉素可抑制人非小细胞肺癌A549细胞的生长,并诱导细胞发生凋亡,其诱导凋亡的作用可能与其调节bcl-2/bax的表达有关。     

芒果苷对人肺腺癌A549细胞增殖的抑制作用及其机制研究

利用相差显微镜观察细胞形态变化情况;用MTT法测定芒果苷对A549细胞增殖作用的影响以及Western-Blot法检测芒果苷对Caspase-3、Caspase-8、Caspase-9蛋白分子表达水平的影响.结果显示,与对照组相比,芒果苷对人肺腺癌A549细胞的抑制率与浓度和时间均呈正相关性.在有效浓度为3μM,作用最佳时间为48h时,A549细胞的镜下形态和结构发生显著的变化;并且导致Caspase-3、Caspase-8、Caspase-9的活性以及它们的剪切小体数量增加.表明芒果苷对人肺腺癌A549细胞具有抑制增殖的作用,并且通过caspase依赖性途径诱导A549细胞凋亡.     

姜黄素与阿霉素联合应用抗肿瘤的协同作用

研究姜黄素与阿霉素联合应用对人纤维肉瘤HT1080、人乳腺癌MCF-7、人肺癌A549细胞的增殖抑制作用及诱导肿瘤细胞凋亡的协同作用,探讨其抗肿瘤协同作用的机制,为临床寻找有效的化疗增敏剂提供实验依据和理论基础.MTT法测定细胞增殖抑制率,结果表明5μmol/L姜黄素与阿霉素联合用药对HT1080、MCF-7、A549细胞均表现出协同抗肿瘤作用;Hoechst 33258荧光染色观察A549细胞凋亡的形态学变化;Westernblot法检测A549细胞bcl-2蛋白的表达,结果表明姜黄素与阿霉素联合应用可显著诱导A549细胞发生凋亡,其协同抗肿瘤的机制可能与下调抑凋亡蛋白bcl-2表达有关.     

石榴鞣花酸提取物对人肺癌细胞A549凋亡的诱导

为了探讨石榴鞣花酸提取物(EAEFP)诱导人肺癌细胞凋亡的作用及其可能的作用途径,以A549肺癌细胞为研究对象,采用四甲基偶氮唑盐(MTT)比色法评估EAEFP对A549肺癌细胞的抑制效果。通过4′,6-二脒基-2苯基吲哚(DAPI)染色法观察EAEFP对A549肺癌细胞形态的作用。利用流式细胞仪测定EAEFP对A549肺癌细胞分裂周期和细胞凋亡的影响。研究结果表明:石榴鞣花酸提取物能显著抑制A549肺癌细胞的生长。随着石榴鞣花酸提取物质量浓度的增加,A549肺癌细胞形态发生明显变化,细胞周期被阻滞在G1期,细胞凋亡率显著增加。石榴鞣花酸提取物能抑制A549肺癌细胞增殖,通过阻滞细胞周期从而诱导细胞凋亡。     

黄芪甲苷通过JAK/STAT3信号通路抑制肺癌细胞增殖和迁移的作用机制研究

目的 探究黄芪甲苷(Astragaloside IV,AS-IV)对肺癌细胞增殖、迁移及作用机制的影响.方法 将体外培养的肺癌细胞A549分为空白对照组和AS-IV 5、10、20μmol/L组.应用四唑盐(MTT)比色法检测细胞存活率;应用蛋白免疫印记实验检测A549细胞P-JAK1和P-STAT3蛋白的表达;细胞集落实验和划痕实验观察A549细胞增殖和迁移情况.结果 黄芪甲苷在浓度低于20μmol/L时没有明显的细胞毒性,低毒下的黄芪甲苷可剂量依赖性抑制P-JAK1和P-STAT3蛋白的表达;细胞集落实验划痕实验结果表明,低毒下的黄芪甲苷可抑制A549细胞增殖和迁移.结论 黄芪甲苷能够通过JAK/STAT3信号通路抑制肺癌细胞A549增殖和迁移.     

周期性牵拉与TNF-α对角膜成纤维细胞增殖的影响

利用Flexcell4000柔性基底拉伸系统对角膜成纤维细胞实施应变为5%或15%、频率为0.1Hz的周期性牵拉载荷,用质量浓度为1ng/mL或10ng/mL的肿瘤坏死因子α(Tumor necrosis factor-α,TNF-α)处理,并采用流式细胞仪检测细胞周期,研究周期性牵拉与TNF-α对角膜成纤维细胞增殖的影响。结果表明:5%周期性牵拉或TNF-α单独作用对正常及圆锥角膜成纤维细胞S期细胞比例均无显著性影响;15%牵拉使正常及圆锥角膜成纤维细胞S期细胞比例均显著下降;与正常角膜相比,15%牵拉和TNF-α共同作用使圆锥角膜S期细胞比例下降更显著。周期性牵拉及TNF-α可能通过抑制圆锥角膜基质细胞增殖参与圆锥角膜的发生和发展。     

绿豆胰蛋白酶抑制剂BBI诱导肺腺癌A549细胞凋亡的研究

研究了绿豆胰蛋白酶抑制剂BBI对人肺腺癌A549细胞增殖抑制作用和对肺腺癌A549细胞凋亡的影响.采用MTT法检测绿豆BBI对人肺癌A549细胞的增殖抑制作用;流式细胞仪检测和光镜观察绿豆BBI诱导A549细胞凋亡;Western-Blot检测凋亡蛋白Caspase3表达情况.结果显示:绿豆BBI对人肺腺癌A549细胞的增殖有明显抑制作用;绿豆BBI可以促使人肺腺癌A549细胞出现明显的染色质浓缩和凋亡小体,诱导人肺腺癌A549细胞的凋亡.说明绿豆BBI能抑制人肺腺癌A549细胞增殖、诱导人肺腺癌?A549细胞凋亡,实验为绿豆BBI抗肿瘤效应提供了依据.     

竹节参总皂苷对人肺腺癌A549细胞凋亡和Caspase-3活性的影响

研究竹节参总皂苷对人肺腺癌A549细胞凋亡和Caspase-3活性的影响,选取0.05、0.1、0.2、0.5、1 mg/m L浓度的竹节参总皂苷作用于体外培养的人肺腺癌A549细胞;并设空白对照组,分别作用24、48、72 h后,应用MTT法检测人肺腺癌A549细胞增殖情况。流式细胞术检测人肺腺癌A549细胞凋亡情况,比色法检测竹节参总皂苷作用于人肺腺癌A549细胞48h后Caspase-3活性。不同浓度的竹节参总皂苷对人肺腺癌A549细胞的增殖有显著的抑制作用(P0.05);并呈浓度和时间依赖性。流式细胞术检测结果为竹节参总皂苷可以诱导人肺腺癌A549细胞凋亡,各浓度组的细胞凋亡率明显高于空白对照组(P0.05);并呈浓度依赖性。说明竹节参总皂苷可抑制人肺腺癌A549细胞增殖和诱导其凋亡。     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

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