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。     

燃料电池混合动力轿车控制策略与参数优化

以某国产经济型轿车为平台,对其动力总成进行了燃料电池混合动力驱动系统的虚拟改装．为提高其整车的经济性和动力性,使用ADVISOR软件对整车性能进行仿真分析,研究了燃料电池混合动力驱动系统开关控制模式和功率跟随控制模式的特性,确定功率跟随控制模式为适合该车型的控制策略．分析了4种典型驱动工况下不同混合动力度的整车经济性及动力性,其中50％的混合动力度是适用于该车型燃料电池混合动力驱动系统最优配置．在此最优配置下,以最小氢气燃料消耗为目标,优化主减速比、燃料电池的最大和最小工作功率以及蓄电池的充电功率,得到了燃料电池混合动力系统的最佳工作点．     

Mn2+在Ti/SnO2+SbOx/PbO2电极上的电氧化研究

比较了Ｔｉ／ＳｎＯ２＋Ｓｂｘ／ＰｂＯ２电极与Ｔｉ／ＰｂＯ２电极在电解Ｍｎ＾２＋体系中的析氧极化曲线、Ｍｎ＾２＋的氧化极化曲线和电极寿命,发现加入中间层后的Ｔｉ／ＳｉＯ２＋ＳｂＯｘ／ＰｂＯ２电极对Ｍｎ＾２＋的电氧化有更好的催化活性和较长的使用寿命。用正交实验法探讨影响Ｍｎ＾２＋→Ｍｅ＾３＋＋ｅ电极过程的因素,找出以Ｔｉ／ＳｂＯｘ／ＰｂＯ２电极为阳极用无隔膜电解槽电解Ｍｎ＾２＋的最佳工艺条件,在此条件     

煤炭地下气化三维非稳定对流扩散的数学模型

研究了煤炭地下气化气体对流扩散的基本特征,在模型试验的基础上,通过对气化发生炉体内煤层燃气化过程中流体浓度场分布和变化规律的分析,建立了三维非稳定对流产扩散模型,阐述了主要模型参数的选取方法,采用上游加权多单元均衡解法对数学模型进行了求解,并对模拟计算结果进行了分析和讨论,计算值和实测值基本相符合,证明了对气化炉内浓度场的数值模拟是可靠的,研究结果为进一步对煤炭地下气化过程进行了定量研究,奠定了必