EGCG对肝癌细胞株BEL-7402增殖凋亡及Stat3蛋白表达的影响

研究了没食子儿茶素没食子酸酯（EGCG）对人肝癌细胞BEL-7402增殖凋亡及对信号转导蛋白和转录激活因子3（Stat3）蛋白及磷酸化Stat3蛋白表达的影响.应用MTT法检测不同浓度EGCG对BEL-7402细胞增殖的抑制作用,用流式细胞仪分析细胞的凋亡率,用ELISA方法检测EGCG对Stat3蛋白及磷酸化的Stat3蛋白表达的影响.结果表明：EGCG有抑制肝癌细胞增殖促进凋亡的作用,并呈剂量依赖性.ELISA结果显示EGCG能降低磷酸化Stat3蛋白的表达水平.EGCG能抑制肝癌细胞的增殖促进凋亡,其机制可能有与下调磷酸化的Stat3蛋白的表达有关.     

力竭运动时阿片肽对免疫机能的作用

本题拟研究阿片肽在力竭运动时对免疫功能的影响,小鼠腹腔注射３．５ｍｇ／ｋｇ体重,注射３０ｍｉｎ手做一次性游泳力竭运动,观察脾的Ｔ淋巴细胞和Ｂ淋巴细胞转化及腹腔巨噬细胞分泌的变化,结果表明,阿征肽可以抑制Ｂ淋巴细胞的增残转化,促进Ｔ细胞的转化;力竭运动使腹腔巨噬细胞分泌白细胞介素－１水平降低,阿征肽可促进腹腔巨噬细胞分泌白细胞介素－１。实验结果提示,阿片肽在体内对不同的免疫细胞作用不同,它可以抑制Ｂ     

运动性免疫抑制的机制研究

为进一步研究运动性免疫抑制的机制 实验方法采用对大鼠进行为期8周,每周6次,每次150min的游泳训练,测定淋巴细胞的增殖功能、细胞因子等免疫指标、血清Gln、Arg含量以及淋巴细胞凋亡的变化。结果显示:①8周大负荷训练后,大鼠血清IL-2含量和淋巴细胞转化率均显著降低,而血清sIL-2R含量却显著升高。②8周大负荷训练后,大鼠血清Gln、Arg含量以及血清GM-CSF含量显著降低,而淋巴细胞凋亡率却显著升高。结论为:①长期大负荷训练可以导致机体细胞免疫功能的显著降低;②长期大负荷的运动训练可以导致血清Gln、Arg含量的降低和外周淋巴细胞凋亡增加,可能是运动性免疫抑制的重要机制。     

Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study

In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies.     

在线社区的知识增殖:用户行为与用户信任的互惠关系研究

[目的/意义] 知识增殖已成为判别在线知识社区成功与否的具体标准。将Web2.0技术所支持的用户行为视作知识增殖的载体,将社区规则、规范所鼓励的人际信任视作知识增殖的条件,考察用户行为与用户信任的互惠因果关系,探索在线社区知识增殖规律。[方法/过程] 采用问卷调查法获取332份有效样本,运用AMOS20.0软件检验模型假设。[结果/结论] 用户行为的发展过程为"知识搜寻行为—知识应用行为—知识贡献行为";用户间信任的发展过程为"认知信任—情感信任",用户行为和用户信任互为因果、二者相互促进实现在线社区知识增殖。     

机械生长因子对骨骼肌卫星细胞激活的影响及与其增殖的量效关系

目的:通过离体实验,观察机械生长因子(MGF)对于骨骼肌卫星细胞(SC)的激活作用及促进其增殖的量效关系,探讨MGF对SC在细胞水平的调节机制,为骨骼肌损伤的修复提供理论依据。方法:原代SC取自4周龄雄性SD大鼠双侧的腓肠肌与比目鱼肌。使用不同浓度的MGF干预第三代细胞后测定增殖效果。血清饥饿后通过MGF和DMEM干预骨骼肌卫星细胞,使用流式细胞仪检测其所处细胞周期,判断激活情况。结果:干预48h后,25ng/ml组、50ng/ml组A值显著高于对照组(P<0.01),100ng/ml组、200ng/ml组与对照组之间差异没有显著性(P>0.05);96h后25ng/ml组、50ng/ml组、100ng/ml组、200ng/ml组之间差异没有显著性(P>0.05)。25ng/mlMGF干预G0期的SC24h后MGF组低于对照组(P<0.01)。结论:MGF可以促进SC增殖;MGF可以激活4周龄SD大鼠的G期SC。     

薄荷叶片愈伤组织的诱导与增殖

以薄荷（Mentha haplocalyx Briq）幼嫩叶片为外植体，采用正交设计L9（3^3）考察6-BA，NAA，2，4-D3种植物生长调节物质对叶片愈伤组织诱导的影响，实验结果表明薄荷叶片愈伤组织诱导最佳培养基为MS＋6—BA10mg／L＋NAA1．0mg／L＋2，4-D0.5mg／L＋蔗糖30g／L．在此培养基上研究不同培养条件对愈伤组织增殖效应的影响，结果表明薄荷愈伤组织继代增殖适合且经济的培养条件为蔗糖20g／L，液体浅层静置培养．     

薄荷叶片愈伤组织的诱导与增殖

以薄荷(Mentha haplocalyx Briq)幼嫩叶片为外植体,采用正交设计L9(33)考察6-BA,NAA,2,4-D3种植物生长调节物质对叶片愈伤组织诱导的影响,实验结果表明薄荷叶片愈伤组织诱导最佳培养基为MS 6-BAl.0mg/L NAAl.0mg/L 2,4-D0.5mg/L 蔗糖30g/L.在此培养基上研究不同培养条件对愈伤组织增殖效应的影响,结果表明薄荷愈伤组织继代增殖适合且经济的培养条件为蔗糖20g/L,液体浅层静置培养.     

酸增殖剂的合成及其应用原理

综述了酸增殖剂研究新进展 ,重点介绍了几种有应用前景的酸增殖剂及其反应机理 .讨论了酸增殖剂在化学增幅型抗蚀剂体系、UV紫外光固化材料、CTP制版中的应用 .     

Assessing the response of indigenous loquat cultivar Mardan to phytohormones for in vitro shoot proliferation and rooting

In vitro cultures of loquat cultivar Mardan were established using shoot apices after treating with NaOCl (5%, 7%, 10%, 12%, 14% (v/v)) for 12 min and HgCl₂ (0.01%, 0.05%, 0.10%, 0.20%, 0.25% (w/v)) for 2 min. A maximum survival rate of 70% was recorded after surface sterilization with 10% NaOCl. Caulogenic response was assessed on Murashige and Skoog (MS) medium fortified with assorted combinations of the cytokinins, benzylaminopurine (BAP), kinetin, and N6-(2-isopentyl)adenine (2iP). Treatment of BAP 1.5 mg/L combined with 2iP 9.0 mg/L and kinetin 1.5 mg/L was found to be optimum for shoot morphogenesis in terms of the number and subsequent growth of shoots, while the highest shoot length was yielded by the combination of BAP 0.5 mg/L, kinetin 0.5 mg/L, and 2iP 3 mg/L. Higher levels of cytokinins induced callogenesis, vitrification and stunted growth to some extent. For rhizogenesis, uniform sized micro-shoots were excised and transferred to half-strength MS medium containing auxins. The best rooting expression was observed with naphthaleneacetic acid (NAA) 1 mg/L combined with indole-3-butyric acid (IBA) 2 mg/L and paclobutrazol (PBZ) 1 mg/L.