硫化氢对高压电机线圈电晕影响的试验研究

为解决西藏羊八井地热电站有害气体硫化氢对高压电机线圈电晕的影响,作者负责的课题组用发电机小样棒在通入硫化氢气体的人工气候室内做了模拟试验,继而到羊八井作实地调查及试验,提出并验证了起晕电压随硫化氢气体浓度增加而降低的关系,给了经验公式。对地热电站用发电机如何解决有害气体硫化氢的危害问题提出了建议。     

大鼠肝细胞系的建立及其特性研究

从 Wistar 新生大鼠肝组织已成功获得正常肝细胞体外长期培养细胞系 NRL-84.细胞生长情况、分裂指数、染色体分析、软琼脂集落形成试验、相差显微镜及扫描电镜等多项指标观察.表明符合正常肝细胞生物学特征;用间接免疫荧光、对流免疫电泳、核酸原位杂交等检测甲胎蛋白,符合正常肝细胞的变动规律.正常新生大鼠的建立是国内首次报导,它将为进一步研究恶性肿瘤的发生发展机制提供了一个良好的实验模型和手段.     

Cell kinetics and radiation pathology

Conclusion Radiation pathology is a general term describing the damage that occurs in tissues after irradiation. After the very low doses, received by the normal working population, no major pathology is seen. There is a hazard of cancer induction if DNA damage that has been inflicted in an individual cell is repaired in such a way that the DNA remains intact but rearranged. This radiation carcinogenesis is however a low risk compared with many chemical carcinogens in the environment and in cancer chemotherapy.The treatment of cancer by radiation is now commonly accepted as one of the most effective forms of treatment. It can kill tumour cells effectively, but the dose that can be given is limited by the normal tissues that are inevitably included in the beam. Cell function is maintained for some time even after very large doses. However normal tissues show a loss of function and structure because the proliferating subcompartment of each tissue is depleted as the radiation injured cells fail to divide and die. The time at which the cell deficit is detected varies from hours in some tissues to months or years in others. It depends upon the normal rate of cell turnover. The apparent sensitivity of each tissue therefore depends upon the time at which the assessment is made. Lung and kidney would appear very resistant at 1–3 months post irradiation, but would seem very radiosensitive at 6–12 months as their latent damage is expressed.The ultimate expression of radiation pathology is the death of the whole animal as the essential organ function fails. The time of this death is only comprehensible if the time sequence and the proliferation kinetics of the target cells are taken into account. It must be recognised that it is initial damage to the clonogenic cells, not to the differentiated cells per se that is important.     

用细胞电泳技术检测化疗药物电性

细胞电泳技术可用于研究氟尿嘧啶(5FU),甲氨喋呤(MTX)和环磷酸胺(CP)等药物的电性,用戊二醛化绵羊红细胞(SRBC)为载体,分别吸附3种化疗药物,均可以导致细胞表面电荷下降致使电泳缓慢率为:5 FU 14.55％,MTX 13.77％,CP 12.21％,这3种药物均带正电荷,此研究对电化学疗法结合化疗治疗恶性肿瘤有参考价值。     

β-phenylethyl isothiocyanate-mediated apoptosis in hepatoma HepG2 cells

-Phenylethyl isothiocyanate (PEITC) is a promising chemoprotective compound that is routinely consumed in the diet as its glucosinolate precursor. Previous studies have shown that PEITC can inhibit phase I enzymes and induce phase II detoxification enzymes along with apoptosis in vitro. The detailed mechanisms involved in the apoptotic cascade, however, have not been elucidated. In the present study, we demonstrate that PEITC can induce apoptosis in hepatoma HepG2 cells in a concentration- and time-dependant manner as determined by TUNEL positive and SubG1 population analysis. Caspase-3-like activity and poly(ADP-ribosyl)polymerase cleavage increased during treatment with 20 µM PEITC; high concentrations, however, induced necrosis. Pre-treatment with Z-VAD-FMK and the caspase-3-specific inhibitor Ac-DEVD-CHO prevented PEITC-induced apoptosis, as determined by caspase-3-like activity and DNA fragmentation. Additional investigations also showed that at concentrations of 5-C10 µM PEITC, DNA synthesis was inhibited and G2/M phase cell cycle arrest occurred, correlating with an alteration in cyclin B1 and p34^cdc2 protein levels. Furthermore, we also demonstrate a concentration- and time-dependant burst of superoxide (O₂^-) in PEITC-treated cells. However, pre- and co-treatment with the free radical scavengers Trolox, ascorbate, mannitol, uric acid and the superoxide mimetic manganese (III) tetrakis (N-methyl-2-pyridyl) porphyrin failed to prevent PEITC-mediated apoptosis. Taken together, these results suggest that PEITC potently induces apoptosis and cell cycle arrest in HepG2 cells and that the generation of reactive oxygen species appears to be a secondary effect.Received 23 December 2002; accepted 22 April 2003     

香蕉生物技术研究进展

本文主要介绍了香蕉生物技术的研究、方法和应用。     

基于Shell脚本的IBM Cell／B．E．模拟环境的自动安装与测试

本文针对IBM Cell/B.E 模拟环境的构建提出了一种借助Shell脚本创建的方法,解决了模拟环境构建中所面临的图形系统的自动启动与配置、License的自动确认、软件的自动安装与配置等问题,并给出了实例测试验证该方法的正确性.这为今后研究和使用IBM Cell/B.E模拟环境提供了一种尝试性的解决方案.     

A reappraisal of the hormonal regulation of larval fat body histolysis in femaleDrosophila melanogaster

The histolysis of larval fat body cells in adult femaleDrosophila melanogaster was examined in wild type and mutant animals. The fat body cells of wild type (Canton-S),apterous ^56f homozygotes,apterous ^78jts homozygotes and heterozygotes,apterous ⁴/+, ecdysoneless¹ homozygotes and heterozygotes all underwent histolysis normally during the 72 h following adult eclosion. Only in the case ofap ⁴/ap⁴ adults did the cells fail to histolyze normally. The fat body cells of both diapausing and non-diapausing wild type females underwent histolysis at the same rate. Attempts to demonstrate histolysis in vitro were unsuccessful, even in the presence of juvenile hormones (JHs), larval ring glands, or adult ovaries. In all strains other than theap ⁴ homozygotes, a significant proportion of larval fat body cells were dead at any time while theap ⁴/ap⁴ animals, almost all cells remained viable. It is postulated that fat body cell lysis following eclosion is not a JH-mediated event, but is elicited by an as yet unidentified factor(s), possibly originating in the ovary.     

高稳定性便于再生的苯酚微生物传感器

这种传感器的细胞固定化是左氢电极膜表面紧贴一层包埋着茁芽丝孢酵母的海藻胶层,再在凝胶层上覆盖一片透析膜,该传感器的基本特性除类似或略优于透析膜包装的传感器外,还具有两个很重要的特点:稳定性高,可反复使用3个月以上;便于培养处理,使因热或化学因子而失活的传感器获得再生。     

Cell size of mammalian myocardia is not related to physiological demand

Morphological characteristics of myocardial ventricular myocytes have been evaluated from 5 mammalian orders with resting heart rates ranging from 51 to 475 bpm. The purpose was to determine if morphological characteristics of the myocardia are related to the functional demand imposed on the cell as represented by the resting heart rate. Cell size is a constant among mammals of different sizes which have different physiological demands. In contrast, there is more mitochondrial area and less myofibrillar area per cell in animals with rapidly beating hearts than in animals with slower heart rates. Additionally, the mean cross sectional area of individual myofibrils is 30% larger in the cow as compared to the mouse. These findings combined with our previous studies indicate that the different functional requirements of myocardia from different mammalian orders are satisfied by intracellular adaptations of both a structural and biochemical nature.