串励直流电动机使用无触点可控硅斩波调速的研究

本文提出了串励直流电动机使用新型无触点斩波调速的新方法。通过两组二段式斩波电路,主电路完全无触点化成为可能,而且扩大了调速使用范围,也证明了可应用于双机车牵引同步自动化控制。     

遗传背景对水稻无融合生殖材料C1001双胚苗频率影响的研究

同核异质雄性不育材料与无融合生殖材料Ｃ１００１Ｂ杂交和回交表明，Ｃ１００１Ｂ的双胚苗，是受核基因控制的性状，双胚苗频率的表达，具明显的胞质效应和胞核效应，在胞质效应中，不育胞质与可质胞质的差异尤其显著，不育胞质对双胚苗的表现有明显的抑制作用，不同世代间胞质效应和胞核效应的表现也不一致。此外，环境条件对Ｃ１００１的双胚苗表现有一定的影响。     

and laminin on adhesion and proliferation of human hepatocellular carcinoma cell

AIM:To explore the effects of PMA(phorbol-12-myristate-13-acetate, a tumor promoter, mimicking the action of diacylglycerol on PKC)and laminin on the adhesion and the proliferation of human hepatocellular carcinoma cells, and provide a new clue to liver cancer treatment.METHODS:Human hepatocellular carcinoma cell line(BEL-7402)was used to identify the endogenous laminin and protein kinase C-α(PKC-α) expression, and the effects of laminin and PMA on the adhesion and the proliferation were also investigatedin vitro.RESULTS:By the effect of exogenous laminin, human hepatocellular carcinoma cell (BEL-7402) possessed endogenous laminin expression and increased the adhesion and the proliferation, which was showed the synergistic action by the effect of PMA in combination. By the action of PMA alone, the proliferation and the PKC-α expression increased by exogenous laminin were decreased, and the adhesion and the endogenous laminin expression were increased.CONCLUSIONS:The finding suggested that the adhesion and the proliferation of human hepatocellular carcinoma cell were closely related to the effects of endogenous or exogenous laminin, which were associated with cPKC-α activity. Therefore, the application of anti-laminin antibody in combination with PKC antagonist might be a new clue to find out the therapy for liver cancer.     

台湾樟芝对碳素营养源利用的研究

本文报道了台湾樟芝 (Antradiacomphora)液体深层培养过程中 ,六种不同碳素营养源组成的合成液体培养基 ,对樟芝菌球生长的影响 ,结果表明 ,樟芝对六种碳源均可利用 ,其中以麦芽糖利用效果最佳 ,菌球数量及菌丝体干重均居首位 ,菌球数量是对照的 3 5 5倍 ,菌丝体干重比对照高出1 73倍 ,樟芝对乳糖的利用较差 ,菌球数量虽比CK仅少 2 5个 / 10 0mL ,但菌体干重相差较大 ,每10 0mL相差 2 5 6 9mg。对樟芝发酵液pH测定情况看来 ,不同碳源组成的培养基终止pH表现不同 ,以麦芽糖、葡萄糖、果糖、蔗糖为碳源的培养基终止pH为 4 5～ 5 0左右。甘露醇为碳源的培养基终止发酵pH为 3 5～ 4 0 ,而乳糖则为 5 5以上。试验表明 ,樟芝菌丝生长极其缓慢 ,在液体深层培养过程中 ,若培养基配方不合理 ,菌球就不生长 ,本文筛选了适合樟芝深层培养的碳素营养源 ,为樟芝的开发和利用提供了科学依据     

Effects of changing PKC activity on proliferation and telomerase expression in human hepatocellular carcinoma cells

AIM: To investigate whether protein kinase C (PKC) is involved in the proliferation and the telomerase expression in human hepatocellular carcinoma cells. METHODS: Human hepatocellular carcinoma cells (BEL-7402) were treated with exogenous phorbol-12-myristate-13-acetate (PMA, PKC activator) and staurosporine (SP, PKC inhibitor) for 48 hours. The techniques of cell culture and the telomeric repeat amplification protocol silver staining in combination with computer image scanning system in vitro were used to observe the variations of the growth and the telomerase expression. RESULTS: The proliferative potential of BEL-7402 cells was decreased by the action of PMA as well as SP, and the telomerase expression was also inhibited by PMA and SP. CONCLUSION: Our findings suggest that the proliferation of human hepatocellular carcinoma cells and the telomerase expression may be related to PKC.     

长江安庆江段存在溯河洄游型和淡水定居型刀鲚实证研究

为了探究长江十年禁渔后安庆江段刀鲚的生境履历,利用X射线电子探针微区分析技术研究安庆江段不同类型长颌刀鲚(Coilia nasus)和短颌刀鲚的耳石Sr和Ca微化学特征。结果显示,根据耳石Sr/Ca值的变化值将安庆江段的短颌刀鲚分为2类,一类是其比值为一直小于3.0的低值,表明其纯淡水的生境履历;另一类是其比值不仅有小于3.0的低值区,还有大于3.0的高值区(小于7.0),表明其不仅有淡水的生境履历,还有高盐度的河口半咸水生境履历。长颌刀鲚的耳石Sr/Ca值均具有小于3.0的低值区和大于3.0 (甚至大于7.0)高值区的显著波动,表现为典型的淡水、河口半咸水及海水的溯河洄游型生境履历,Sr含量面分析图谱也可印证上述结果。本研究表明,长江安庆江段刀鲚群体组成较为复杂,同时存在溯河洄游型、淡水定居型短颌刀鲚和溯河洄游型长颌刀鲚3种生态表型个体。     

维生素B12解冻液在绵羊人工授精中的应用

应用维生素B12注射液做绵羊冻精的解冻液,实施人工授精配种来提高绵羊受胎率和羔羊成活率。结果表明,试验组绵羊受胎率达96.0%,羔羊成活率达94.2%,而对照组绵羊受胎率为78.0%,羔羊成活率为85.4%,试验组与对照组绵羊受胎率和羔羊成活率均有显著性差异(P<0.05)。     

基于蓝牙技术的车载免提系统研究

通过对蓝牙技术的简单介绍,分析蓝牙技术在车载免提系统中的应用,同时给出系统的硬件设计与软件结构。介绍了系统的主要器件的选择、工作原理和主要功能。     

农杆菌介导的hIL-12基因转化马铃薯的研究

构建CaMv35S启动子驱动人白细胞介素12基因(hIL-12)的植物表达载体pBI121-hIL-12,通过三亲杂交法将重组载体导入根癌农杆菌菌株EHA105,农杆菌介导法转化马铃薯茎段,经卡那霉素抗性筛选,获得28株抗性植株。通过PCR检测,22株为阳性,从PCR阳性植株中随机选取5株,ELISA法检测茎和叶中hIL-12的表达量,其中2株与对照组相比有显著性差异(p<0.001),hIL-12的表达量分别为(3 714.0±48.8)pg/g和(3 465.0±185.0)pg/g,初步表明外源基因hIL-12已经整合进马铃薯基因组中并得到了表达,为进一步研究重组hIL-12的分离纯化和生物学活性奠定了试验基础。