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。     

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…     

丙烯腈反应器新型两级旋风分离器性能计算方法研究

丙烯腈反应器新型两级旋风分离器由常规的PV型和新开发的PV E型旋风分离器组成。这种分离器具有结构简单、分离性能好、操作稳定等优点 ,能增加现有丙烯腈反应器的处理能力 ,但是目前缺少一种可靠的计算其性能的方法。根据PV型和PV E型旋风分离器的异同 ,提出了一种基于PV型旋风分离器性能计算法的修正方法。冷态试验结果及工业标定数据表明 ,该方法的计算结果可靠 ,精度较高 ,能用于丙烯腈反应器新型两级旋风分离器的设计或指导生产。以齐鲁石化公司 4× 10 4t/a丙烯腈装置为例进行了计算 ,其结果可为分离器设计提供依据     

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.     

料浆法磷铵生产中新型管式反应器的研究与应用

传统的管式反应器用于料浆法磷铵中和杂质含量较高的磷酸时,易于结垢、堵塞.为此,研制了一种新型管式反应器,并于3×104t/a料浆法磷铵工业装置上进行72h考核与一个月的连续运行试验.结果表明:采用这种新型管式反应器,可缩短中和反应时间、减少非水溶性化合物的生成、提高磷铵产品水溶P2O5和解决了结垢、堵塞的问题.     

准均质充量压燃发动机低负荷排放性能的试验研究

通过试验研究了引燃油量和进气节流对天然气／柴油双燃料准均质充量压燃(QHCCI)发动机低负荷排放性能的影响．结果表明：在低负荷时适当地增加引燃油量，不但可以降低QHCCI发动机的排放，又可以提高其热效率；适当采用进气节流，可在热效率略有降低的情况下有效地改善QHCCI发动机在低负荷时的排放性能；在增大引燃油量的同时采用一定程度的进气节流对降低QHCCI发动机低负荷排放更为有利．