KK-42对家蚕蛹血淋巴及卵巢蛋白质合成的影响

研究了咪唑类化合物KK—42对家蚕卵巢发育以及蛋白质合成的影响,结果表明KK-42对卵巢增重有明显的抑制作用,血淋巴蛋白含量在蛹期变化幅度很小,卵巢蛋白质含量增加也很缓慢;而对照区在化蛹后,血淋巴蛋白急剧增加,第三天达到高峰,以后又迅速下降,与卵巢蛋白质增加相吻合。由此表明,咪唑类化合物KK-42不仅抑制血淋巴蛋质的合成,同时还抑制了血淋巴蛋白向卵巢的转移。     

Inlfuence of FSH Treatment on Expression of CDC25A,TSSK3 and P53in Vitro Cultured Sertoli Cells of Calf

CDC25A, TSSK3 and P53 expressionsin vitro in cultured sertoli cells after FSH treatment were studied in order to provide some data for further researches of spermatogenesis. Different concentrations of...     

纽荷尔脐橙成年态节间茎段遗传转化研究

建立柑橘成年态节间茎段的离体再生和遗传转化系统是实现柑橘转基因育种实用化的前提基础。本试验以纽荷尔脐橙成年态节间茎段为试材,初步建立了脐橙成年态节间茎段的离体再生和遗传转化系统。结果表明采用改良的预处理灭菌法对成年态茎段进行消毒处理,污染率明显降低。节间茎段在MS＋3mg／L6-BA的培养基上,不定芽再生率较高。采用根癌农杆菌介导法将外源抗真菌病基因chit42导入其中,抗性芽通过二次嫁接后获得再生植株,PCR检测4株抗性植株中有2株扩增出该特异性条带,RT-PCR分析进一步确认外源基因chit42能够在转基因植株的基因组中表达。     

Effect of tetrandrine on radiosensitivity of nasopharyngeal carcinoma cells

AIM: To investigate the mechanism of the radiosensitizing effect of maximum non-cytotoxic doses of tetrandrine (Tet) on nasopharyngeal carcinoma cell lines CNE1 and CNE2.METHODS: The cells were treated with ma-ximum non-cytotoxic doses of Tet (for CNE1 cells at 1.5 μmol/L and for CNE2 cells at 1.8 μmol/L), irradiation at 4 Gy, or combination of irradiation and maximum non-cytotoxic doses of Tet. The cell cycle distribution was analyzed by flow cytometry. The protein levels of γ-H2AX, cleaved caspase-3, p-CDC25C, CDK1, p-CDK1, cyclin B1, ERK and p-ERK were determined by Western blot.RESULTS: The expression of γ-H2AX was increased in CNE1 cells and CNE2 cells after combined treatment with irradiation and maximum non-cytotoxic doses of Tet. The percentages of CNE1 cells and CNE2 cells at G₂/M phase in irradiation group were (18.09±0.42)% and (18.48±1.32)%, respectively, which were decreased to (15.88±1.04)% and (13.80±0.82)% in combined treatment group, respectively (P<0.05). Combined treatment enhanced the increase in the protein level of cleaved caspase-3 caused by irradiation. The protein levels of p-CDC25C and p-CDK1 were increased in a dose-dependent manner by Tet treatment (P<0.05), while the expression of CDK1 showed no difference among different doses of Tet treatments. The protein levels of p-CDC25C, p-CDK1 and CDK1 showed no difference after the treatment with maximum non-cytotoxic doses of Tet. The combined treatment with irradiation and the maximum non-cytotoxic doses of Tet decreased the protein levels of p-CDC25C and p-CDK1 (P<0.05), increased the expression of cyclin B1, and had no influence on the expression of CDK1 (P<0.05). The combined treatment resulted in an increase in the protein level of p-ERK1 (P<0.05).CONCLUSION: The maximum non-cytotoxic doses of Tet enhance the DNA damage and apoptosis in CNE1 cells and CNE2 cells caused by irradiation, and the mechanism might be associated with ending of G₂/M arrest via activation of ERK/CDC25C/CDK1/cyclin B1 pathways.     

TRMM在海河流域南系的降水估算精度评价及其对SWAT模型的适用性

准确估算区域降水对水文过程评价和水资源管理意义重大。为评估TRMM 3B42V7降水产品在海河流域南系的估算精度及其在土壤和水评估模型(Soil and Water Assessment Tool,SWAT)中的适用性,利用28个气象站降水观测数据(2007-2016年)和101个雨量站观测数据(2010-2016年)开展研究。研究表明:站点尺度上,3B42V7降水产品对月降水估算的均方根误差小于15 mm,平均误差小于8.5 mm;在湿润季节的估算精度更好。流域尺度上,日降水估算精度较差,相关系数小于0.6。分区尺度上,3B42V7能够很好地捕捉到不同等级降水强度,但对微量降雨有所低估;山区和平原的年降水量均出现高估现象,平原区较为突出;此外,3B42V7能够较好地捕捉到研究区内极端降水的时间和空间分布。分2种情景进行水文模拟,利用月平均流量对模型进行校准和验证,在情景Ⅰ中,验证期模拟结果较好,决定系数在0.56~0.96之间,纳什效率系数在-11.09~0.94之间。TRMM 3B42V7可为海河流域及其类似区域的水资源管理提供参考。     

保幼激素拮抗物KK-42对南美白对虾Y-器官发育的影响

采用1.95×10-4mol.L-1的KK-42溶液浸润处理南美白对虾(Penaeus vannamei)幼虾(体长为4.2~5.0cm),从组织细胞学水平对分泌蜕皮激素的Y-器官结构进行初步研究,观察KK-42处理后幼虾Y-器官的形态结构变化。结果表明,伴随动物的生长,Y-器官腺细胞条索变粗,腺细胞核增大。KK-42处理后腺细胞核的结构、大小未见显著变化,腺细胞索的宽度明显高于同一时期对照组。     

Effects of RNA interference targeting CDC25agene on proliferation of human liver cancer HepG2 cells

AIM: To investigate the effect of silencing cell division cycle 25a (CDC25a) gene on the proliferation of human hepatoma HepG2 cells. METHODS: CDC25agene in human hepatoma HepG2 cells was silenced by RNA interference. Real-time PCR was applied to detect the expression of CDC25a, cyclin E and CDK2 at mRNA levels in the HepG2 cells. Western blotting was applied to detect the expression of CDC25a at protein level. In addition, MTT assay, Giemsa staining and flow cytometry were used to measure the proliferation of human hepatoma HepG2 cells. RESULTS: The expression of CDC25a at mRNA and protein levels in RNA silence group was lower than those in negative control group and normal control group (P＜0.05). The mRNA expression of cyclin E and CDK2 in silence group was lower than that in negative control group and normal control group (P＜0.05). The cell proliferation in silence group was lower than that in negative control group and normal control group (P＜0.05). The results of flow cytometry revealed that the cells in silence group were blocked in G1 phase. CONCLUSION: Infection of LV-CDC25a-RNAi recombinant to the HepG2 cells effectively inhibits the CDC25agene expression and the proliferation of human hepatoma cells, and arrests the cells in G1 phase, suggesting that CDC25agene may be a key target for the treatment of liver cancer.     

食用蕈菌天然食品防腐剂发酵工艺的研究

将从食用蕈菌筛选出来的天然食品防腐剂生产菌Ｅ．Ｆ．１５和Ｅ．Ｆ．４２分别进行深层发酵，用既定筛选模型系统的跟踪模型逐一测试其发酵产物的抑菌效价。梯度试验结果表明，Ｅ．Ｆ．１５和Ｅ．Ｆ．４２的最适发酵周期，最适发酵温度，发酵液最适起始ｐＨ，摇床最适转速，发酵液最适装量和最适接种量（ｖ／ｖ），分别为６ｄ，２５～３０℃，７．０～７．５，１５０ｒ／ｍｉｎ，２００ｍＬ（５００ｍＬ三角瓶）和１５％。     

车用42V电气系统的结构特点及对整车结构的影响分析

分析了提升汽车电源电压从14V到42V的技术原因。重点介绍了组成汽车42V电气系统的结构特点和对整车结构的影响。也指出了发展42V电气系统在技术与市场上存在的困难。