精巢间质细胞雄激素合成及其调节的研究进展

本文综述了近年来精巢间质细胞雄激素的合成及其分泌调节的研究进展。间质细胞内的雄激素合成的限速步骤是胆固醇转化为孕烯醇酮时的胆固醇跨线粒体膜转运。在此转运过程中，PBR可能是作为依赖于配体的通道蛋白，对胆固醇分子进行跨膜转移；StAR则通过解离线粒体膜与胆固醇分子的吸附作用，加速了胆固醇分子的转运。雄激素的合成还受垂体、支持细胞、巨噬细胞和其自身分泌激素和细胞因子的调控。同时对今后研究的方向做了总结和展望。     

RNA抑制技术在神经干细胞研究中的应用

神经干细胞是在神经系统中发现的一种可以再生的细胞，不仅具有自我复制能力，还可以分化为神经元、星状胶质细胞和少突胶质细胞，对研究神经退行性疾病和神经系统的发育过程产生很大的影响，因而在国际上形成了一个研究热点，但其增殖、分化乃至迁移的机制仍有待解决，RNA抑制技术是目前流行的基因沉默法，利用导入小片段核酸进入细胞，对特定基因表达的翻译阶段进行抑制，从而观察基因对细胞的影响，该文在已获得分化相关基因的基础上，利用RNA干扰(RNAi)和反义RNA(antisense RNA)法检测几个基因对神经干细胞的影响。     

刷轮式苗盘精播装置排种板型孔直径的设计

为使种子在活动型孔板移动过程中，能够依靠自重顺利排出。固定排种板必须具有台理的直径，利用活动型孔板回移复位的结构特点，理论分析了种子顺利排出而不被回位型孔板干涉所需最少时间的条件，在此基础上优化设计排种板型孔直径。     

EUT对TEM传输室特性阻抗影响的边界元分析

采用边界元法分析了金属箱体的受试设备对横电磁波传输室特性阻抗的影响．计算结果表明，当受试设备不满足“三分之一准则”时，对特性阻抗的影响达5Ω以上，当满足“三分之一准则”时，对特性阻抗的影响小于2Ω．测量结果证实了计算方法的有效性，所得结论对TEM传输室的设计与测试具有重要意义。     

Inhibitory effect of the adenovirus type 5 E1A protein expressed in the yeast system

The human adenovirus type 5 E1A, a tumor- suppressor gene[1], codes for two major related proteins of 243 amino acids (12S) and 289 amino acids (13S) by al-ternative splicing in two exons[2]. Studies have been shown that E1A can regulate expression of many genes and cell cycle[3]. Both in vitro and in vivo experiments indicated that E1A could induce tumor cells differentia-tion, convert tumor cells into an epithelial phenotype, in-hibit tumor cell growth and metastasis and strongly en-ha…     

Mechanical Studies on Treatment of Malignant Tumour by Ultralow Frequency Pulsed-Gradient Magnetic Fields

Ultralow frequency (ULF) pulsed-gradient magnetic field (with the maximum intensity of 0.6-2.0 T, gradient of 10-100 T·m-1, pulse width of 20-200 ms and frequency of 0. 16-1. 34 Hz) treatment of mice can inhibit murine malignant tumour growth and can induce apoptosis of cancer cell. The apoptotic cancer cell contracted, became rounder and divorced from adjacent cells; the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane; the endoplasmic reticulums expanded and fused with the cellular membrane; many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma. By Lorentz force the magnetic field keeps the moving ions within bounds of Larmor radius. Thus, penetrating capability of the positive and negative ions through the cell membrane was affected, even the role on the cell membrane formed.     

Effects of hyaluronic acid－chitosan－gelatin complex on the apoptosis and cell cycle of L929 cells

With the development in the field of tissue engineering, the interaction between biomaterials and cells has been deeply studied. Viewing the cells seeded on the surface of materials as an organic whole, cell cycle and apoptosis are analyzed to deepen the study of cell compatibility on biomaterials, while cell proliferation and differentiation are studied at the same time. In this paper, hyaluronic acid is incorporated into the chitosan-gelatin system. Propidium iodide (PI) was used in cell cycle analysis and the double-staining of cells with annexin-V and PI was applied in cell apoptosis analysis. The results show that incorporated hyaluronic acid shortens the adaptation period of cells on the material surface, and then cells enter the normal cell cycle quickly. In addition, added hyaluronic acid inhibits cell apoptosis triggered by the membranes. Therefore, hyaluronic acid improves the cell compatibility of chitosan-gelatin system and benefits the design of biomimetic materials.     

Inhibitory effect of the adenovirus type 5 E1A protein expressed in the yeast system of the human tumor cell growth

Adenovirus 5 type E1A as a tumor suppressor gene can inhibit tumor growth and enhance the censitivity of chemotherapy and radiotherapy.E1A have the ability to integrate into the host genome,resulting in long-time expres-sion that induces Rb gene inactivation and animal cells im-mortalization.This prompted us to select the E1A protein for treatment of cancer in order to overcome the limitations of E1A gene therapy.Thus,we firstly comstructed E1A eu-caryotic expression vector (pPIC9/E1A),transformated the pichia pastoris yeast cells(GS115) and screened the high-expressing recombinant strains.The positive yeast strains were cultured in the shake flask,and induced for 3d.The crude E1A protein was purified using two steps of col-umu chromatography on HiTrap Q and HiTrap SP.The pu-rified E1A protein was identified by SDS-PAGE and Western blot.E1A protein was mostly located at cellular unclear when Cheriot delivered E1A protein into cells.The analysis in vitro indicated that the E1A protein arrested LN686 cell cycle at G2/M phase,and significantly inhibited the growth of LN686 tumor cells.The current studies firstly provided an experimental basis to further develop E1A protein for tumor treatment.     

彗星电泳检测细胞DNA损伤应用新进展

彗星电泳是近年发展起来的一种测定单个细胞DNA损伤的方法 ,因其操作简单、快速及灵敏等特点 ,应用范围十分广泛 .着重介绍了这一技术的发展、图形分析及应用进展     

熔融碳酸盐燃料电池阴极材料制备与导电性

研究了熔融碳酸盐燃料电池（MCFC）阴极材料锂铁氧化物电极的导电性能。实验结果表明在合成锂铁氧化物的过程中，使Li2CO3轻微过量，可以提高锂铁氧化物电极的导电性。在同一温度下，随着Li:Fe值的增大，锂铁氧化物电极的导电性增加。相同Li:Fe条件下，锂铁氧化物电极的导电性随着温度升高按指数规律增加。扫描电镜研究（SEM）表明，Li:Fe比值不同，制备的锂铁氧化物电极表面形貌也不同。