玉米联合固氮工程菌Enterobacter gergoviae E7在田间的接种效应

 在黑龙江省以及吉林省适宜的农田管理条件下 ,连续 3年田间小区接种试验证明 ,接种联合固氮工程菌 E7( Entrobacter gergoviae E7)对玉米的增产、节肥效应都优于接种野生型菌 ,但增产幅度随土质不同有很大差异。在贫瘠的白浆土、砂壤土中 ,在相同施肥水平下 ,接种工程菌 E7比无菌载体平均增产 1 2 .3%,比接种野生型菌平均增产 8.8%;在相同产量水平下 ,接种工程菌比无菌对照节省氮肥 1 5%～ 2 0 %,比接种野生型菌节省氮肥 1 5%。而在草甸黑土中接种效应不明显。     

基于MATLAB的空间7R机构位置分析的新方法

利用向量回转法和MATLAB软件对空间7R机构位置问题进行了分析研究，确定了各杆长和副长方向的单位向量，列出了机构的向量封闭方程，以及各杆位置方程；调用MATLAB矩阵运算函数和解非线性方程组函数，解出了其他各杆的位置与主动件输入角度的关系，以及任何一杆上任意点的空间轨迹，并利用绘图函数表达各杆的位置曲线及任意点的轨迹。实例分析证明所提出的方法是可靠的。     

荷斯坦牛新遗传缺陷单倍型HH7分子筛查

HH7(Holstein Haplotype 7)是在荷斯坦牛群中新发现的一种隐性遗传缺陷单倍型,由27号染色体上CENPU基因4个碱基缺失突变引起,隐性基因纯合时能引起胚胎早期流产,严重影响着奶牛养殖者的经济效益.本研究利用竞争性等位基因特异性PCR(KASP法)对随机抽取的166头荷斯坦公牛样本进行了检测分析,结果...     

Zerumbone attenuates MPP+-induced cytotoxicity in human neuroblastoma SH-SY5Y cells by inhibition of oxidative stress

AIM: To investigate the role of zerumbone (ZER) in 1-methyl-4-phenylpyridinium (MPP⁺)-induced cytotoxicity of human neuroblastoma SH-SY5Y cells. METHODS: Human neuroblastoma SH-SY5Y cells were cultured in vitro and the protective effect of ZER against MPP⁺-induced cytotoxicity was measured by CCK-8 assay. Flow cytometry was used to determine the apoptosis and reactive oxygen species (ROS). The expression of Parkinson disease protein 7 (PARK7) was knocked-down by using PARK7-specific short hairpin RNA (shRNA). The protein levels of PARK7, nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were determined by Western blot. RESULTS: MMP⁺ remarkably reduced the cell viability in a dose-dependent and time-dependent manner. The SH-SY5Y cell injury model was established by treatment with MPP⁺ at 600 μmol/L for 24 h. ZER up-regulated the protein levels of PARK7 and Nrf2 (P<0.05), alleviated apoptosis (P<0.05), and reduced ROS production (P<0.05) in the SH-SY5Y cell injury model. Meanwhile, N-acetyl-L-cysteine (NAC) had the similar functions. Moreover, significant reductions in the protein levels of Nrf2 and HO-1 (P<0.05), and obvious increases in apoptosis (P<0.05) and ROS level (P<0.05) were demonstrated in PARK7-knockdown cells. CONCLUSION: ZER protects SH-SY5Y cells against MPP⁺-induced cytotoxi-city, which may be related to activation of PARK7/Nrf2/HO-1 pathway, and subsequent attenuation of oxidative stress and apoptosis.     

某牛场粪源大肠杆菌0157∶H7的分离鉴定

为了解重庆市某牛场牛群大肠杆菌O157∶H7的感染情况,我们以牛场犊牛为研究对象,采集其新鲜粪便,经LB培养基增菌培养、免疫磁珠富集后,在山梨醇麦康凯琼脂上划线培养,最后PCR扩增eaeA基因目的片段,以此分离鉴定粪源大肠杆菌O157∶H7。结果显示：在所采集的39份犊牛粪便样品中,分离得到一株符合大肠杆菌O157∶H7生长特点且含有eaeA基因的菌株。     

改良昌7-2玉米自交系配合力研究

利用13个玉米自交系,按NCⅡ不完全双列杂交设计配制成42个杂交组合,随机区组排列,田间品比鉴定和室内鉴定相结合。结果表明,西农672产量配合力高于昌7-2和7117,穗长、结实长、穗行数和行粒数性状的配合力高于昌7-2、PH6wc和7117;西农672出籽率性状配合力低于昌7-2,株高配合力低于PH6wc,高于昌7-2,也高于7117;西农672穗位高配合力高于PH6wc和7117,低于昌7-2。西农672出籽率配合力与PH6wc相近;叶面积系数、穗长、穗行数、结实长、行粒数比昌7-2高,百粒重、小区产量配合力比PH6wc略低。用PH6wc来改良昌7-2得到的西农672,综合性状改良效果较为显著。用PH6wc改良昌7-2育成西农672与用昌7-2×武117育成的7117和昌7-2相比较,其产量配合力、产量性状、农艺性状配合力等均有显著提升。     

Breast cancer stem cells cultured without insulin and effect of estrogen induction

AIM:To determine whether suspension culture medium without insulin can be used to feed breast cancer tumorsphere, or not. METHODS:MCF7 cells were used to build tumorsphere. The morphological changes, CD44+ CD24- expression, aldehyde dehydrogenase 1 (ALDH1) expression and multiple division ability were measured to identify the breast cancer stem cells and to detect the function of 17β-estradiol (E2β) in tumorsphere of MCF7 cells. RESULTS:The tumorshere, each containing 30 to 60 cells, was obtained by the method of insulin-removal suspension culture. These cells were cytokeratin 18 and CD10 proteins positive, and the number of CD44+ CD24- cells and ALDH1 protein expression were significantly higher than the adherent cultured cells (P<0.05). Using 10-10 mol/L E2β to treat the tumorshere for 7 d, the tumor cell number and volume were significantly increased. Using 10-10 mol/L E2β to treat the tumorshere for 24 h, the CD44+ CD24-cells and ALDH1 protein expression were significantly higher than those in non-treatment group (P<0.05). CONCLUSION: Suspension culture medium without insulin can be used to feed breast cancer tumorsphere. These tumorsphere could be used as a model to determine the function of E2β in breast cancer stem cell research.     

猪TLR7基因胞外区部分片段的克隆、表达及其重组蛋白的纯化分析

[目的]获得高表达量的蛋白,为进一步研制单克隆抗体提供较好的免疫原,同时也可为TLR7胞外区该片断蛋白未知区域的结构和功能研究奠定基础。[方法]应用PCR技术从重组质粒pcDNA3．1／CT-GFP-pTLR7上扩增出编码猪TLR7基因胞外区N端第27—202位氨基酸序列,利用BamHI和HindⅢ酶切位点将其插入到原核表达载体PE130a中,重组质粒转化BL21（DE3）后,在不同条件下诱导表达。[结果]经SDS．PAGE分析表明,重组菌表达出约26kD的融合蛋白,并证实主要以包涵体形式表达,其最佳诱导表达条件是37℃、0．5mm01／LIPTG诱导6h,表达量可接近50％;纯化的重组蛋白免疫小鼠后,间接ELISA检测抗体效价,结果该蛋白免疫BALB／c小鼠效价达10^5．[结论]TLR7胞外区该片断重组蛋白具有很好的抗原性,可以作为单克隆抗体研制的免疫原。     

Effects of WNT5B over-expression on viability and apoptosis of human breast cancer cell line MCF-7

AIM: To detect the expression of WNT5B in normal breast epithelial cells and different breast cancer cell lines, and to investigate the effects of WNT5B over-expression on the viability and apoptosis of human breast cell line MCF-7.METHODS: The mRNA expression of WNT5B was detected by RT-PCR in different breast cancer cells. MCF-7 cells were transfected with plasmid pcDNA3.1/WNT5B or pcDNA3.1, and the expression of WNT5B at mRNA and protein levels was examined in the 2 groups by real-time PCR and Western blotting, respectively. Subsequently, the changes of cell viability and cell apoptosis were analyzed by CCK-8 assay and flow cytometry, respectively. RESULTS: The expression of WNT5B in the breast cancer cell lines was lower than that in MCF10A cells. The WNT5B expression in the MCF-7 cells in experimental group was significantly higher than that in vector group (P<0.05). However, the cell viability in experimental group decreased significantly as compared with vector group (P<0.05). The number of the cells in S-phase obviously increased, while the percentage of the cells in G₁-phase and G₂/M-phase decreased compared with vector group. The number of apoptotic cells in WNT5B group was significantly higher than that in vector group.CONCLUSION: The expression of WNT5B is decreased in breast cancer cells. WNT5B over-expression significantly inhibits the cell growth and promotes the cell apoptosis in breast cancer MCF7 cells.     

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。