电刺激促进成骨细胞粘附特性的实验研究

针对骨组织工程中成骨细胞与基质材料间促粘附这一重要问题,研究微量直流电刺激对成骨细胞粘持性的影响。方法取兔骨髓基质干细胞来源的成骨细胞体培养,于接种即时行微量直流电刺激,刺激电流密度为１００μＡ／ｃｍ＾２,观察电刺激后１、２、６、１２ｈ及２４ｈ各时间点接种成骨细胞粘附情况、体视学计量粘附细胞数量。结果１００μＡ／ｃｍ＾２微量直流电刺激下,阳极区细胞粘附数量与阴极区相比,各时间点均寺加;无直流电刺激     

植物细胞工程药物生产的研究进展

通过对植物生产药物几个阶段的概述 ,重点介绍了植物细胞大规模培养进行药物生产的进展、存在问题以及一些新技术的运用。最后介绍了转基因植物生产药物的前景。     

缓冲液条件对水霉细胞壁结合Ca2+的影响

用原子吸收光谱研究了pH值、Tris 马来酸缓冲液浓度对水霉 (Saprolegniaferax)顶端生长菌丝细胞壁与Ca2 结合的影响 .发现在 pH 3.5～ 6 .0范围内 ,细胞壁结合的Ca2 随 pH值升高而增加 ,pH >6 .0时 ,细胞壁结合的Ca2 呈下降趋势 .细胞壁结合的Ca2 随Tris 马来酸缓冲液浓度升高而增加 ,Tris浓度高于 9mmol/L时 ,细胞壁结合的Ca2 则减少 .细胞壁最多可结合Ca2 量>6 0 μmol/L .证明细胞壁Ca2 确实是水霉顶端生长赖以维持的胞外Ca2 库 .     

DNA-protein interaction at erythroid important regulatory elements of MEL cells byin vivo footprinting

Using ligation-mediated PCR method to study the status of DNA-protein interaction at hypersensitive site 2 of locus control Region and β^maj promoter of MEL cell line before and after induction, MEL cell has been cultured and induced to differentiation by Hemin and DMSO, then the live cells have been treated with dimethyl sulfate. Ligation mediated PCR has been carried out following the chemical cleavage. The results demonstrate that before and after induction, the status of DNA-protein interaction at both hypersensitive site 2 and β^maj promoter change significantly, indicating that distal regulatory elements (locus control region, hypersensitive sites) as well as proximal regulatory elements (promoter, enhancer) of β-globin gene cluster participate in the regulation of developmental specificity.     

Inhibition of free radical induced oxidative hemolysis of red blood cells by green tea polyphenols

The in vitro oxidative hemolysis of human red blood cells (RBC) was used as a model to study the free radical induced damage of biological membranes and the inhibitory effect of natural antioxidants. The hemolysis was induced by a water-soluble free radical initiator 2,2′-azo(2- asmidinopropane)dihydrochloride (AAPH) and inhibited by the principal polyphenolic components extracted from green tea leaves, i.e. (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicat- echin gallate (ECG), (-)-epigallocatechin gallate (EGCG) and gallic acid (GA). Addition of AAPH at 37°C caused fast hemolysis after a short period of inhibition period, while addition of the green tea polyphenols efficiently suppressed the hemolysis in the activity sequence of EGCG＞EGC＞ECG≈EC＞GA, demonstrating that these green tea polyphenols are effective antioxidants which could protect biological membranes from free radical induced oxidative damage.     

Chemical treatments of the nanocrystalline porous TiO2 electrodes

Two types of nanocrystalline porous TiO₂ electrodes were prepared by the hydrothermal and painting methods. The incident photon-to-current efficiency and photoelectrical conversion efficiency were both improved by chemical treatments of titanium tetrachloride and titanium isopropoxide. The surface roughness, quantities of adsorbed dye, photocurrent-voltage curves, IR spectra and UV-visible absorption spectra were measured, and the mechanism of chemical treatments was discussed.     

横电磁室的数值分析方法及应用的新进展

本文介绍几种用于分析横电磁室 ( TEM Cell)的数值分析方法 ,以及所得到的分析结果。另外还介绍了横电磁室的新技术及应用。     

浅析林语堂的文学语言观

在文学语言的发展道路上 ,林语堂先生以短小精悍的文章 ,积极探讨文学语言正确与健康的发展方向 ,他的文学语言观在社会中产生了较大的影响 ,对今天的文学语言研究和修辞研究也具有一定的指导意义     

多值单调型算子不动点带有误差项的Ishikawa迭代逼近

在一致光滑Ｂａｎａｃｈ空间中,证明了带有误差项的Ｉｓｈｉｋａｗａ迭代序列强收敛于一类多值单调型算子的唯一不动点。这些结果改进和推广了Ｄｕｎｎ,Ｃｈｉｄｕｍｅ,Ｄｅｎｇ－Ｄｉｎｇ,丁协平,Ｃｈａｎｇ－Ｔａｎ等人的最新结果。     

国产胸腺肽诱导肝癌细胞凋亡及其机制

以ＭＴＴ法检测胸腺肽对ＨｅｐＧ２的细胞毒作用,以细胞原位凋亡染色法（Ｔｕｎｅｌ法）检测胸腺肽诱导ＨｅｐＧ２细胞凋亡,并以ｗｅｓｔｅｒｎ－ｂｌｏｔ法及免疫组化法检测药物处理后ｂｃｌ－２、Ｆａｓ抗原的表达变化。结果显示在０～１５０ｕｇ／ｍＬ浓度范围内,胸腺肽对ＨｅｐＧ２无明显的细胞毒作用,当药物浓度超近１５０ｕｇ／ｍＬ以上,细胞毒作用呈上升趋势,其ＩＣ５０为３３０ｕｇ／ｍＬ,而低于１５０ｕｇ／ｍＬ的胸