传统山西老陈醋增香酵母菌的筛选及其特性研究

为选育山西老陈醋用微生物发酵剂,从传统发酵工艺生产的山西老陈醋中分离筛选到5株增香酵母菌。结合形态学和酵母菌26S rDNA Dl/D2区序列分析,初步鉴定Y1为酿酒酵母(Saccharomyces cerevisiae),Y26为毕赤酵母(Pichia scaptomyzae),Y30为假丝酵母(Candida humilis),Y68为红酵母(Rhodotorula sp.),Y70为盔形毕赤酵母(Pichia membranifaciens)。采用固相微萃取和气-质联用技术分析这5株酵母发酵液的主要挥发性成分。结果表明,醇类和酯类挥发性成分种类和组成差异较大;对这5株酵母菌进行耐酸性、乙醇耐受性、高温耐受性发酵试验,结果表明毕赤酵母Y26具有优良的耐酸性、乙醇耐受性。综合其具有高产乙酯类、低产高级醇的特性,毕赤酵母Y26有望开发为山西老陈醋的新型发酵剂。     

青钱柳叶三萜大孔吸附树脂纯化工艺

为研究大孔吸附树脂纯化青钱柳三萜的工艺,筛选了适宜的大孔吸附树脂,并通过静态和动态的吸附与解吸试验,确定了纯化工艺参数。结果表明,在供试的3种大孔吸附树脂中,D-101型大孔吸附树脂适合分离青钱柳叶三萜,其吸附量和解吸率分别为57.5mg/g和96.51%;动态吸附青钱柳叶三萜时的最适宜进样流速与进样质量浓度分别为 2BV/h和1.5mg/mL;动态解吸时洗脱剂的最适宜体积分数与洗脱速度分别为50%乙醇和2BV/h。经大孔吸附树脂分离纯化后三萜的纯度是粗提物的4.1倍,得率为74.66%,表明D-101型大孔吸附树脂纯化青钱柳三萜效果较佳。     

Influence of murine cytomegalovirus infection on the differentiation and the differentiation genes expression in neural stem cells

AIM: The influence of MCMV infection on differentiation and differentiation gene expression in neural stem cells(NSCs) in vitro were investigated for studying the mechanisms of brain abnormalities caused by congenital cytomegalovirus infection.METHODS: NSCs were separated from fetal BALB/C mouse, and cultured and identified in vitro. The differentiation potency of NSCs was observed by immunofluorescence. The NSCs infected by MCMV at dosage of MOI(multiplicity of infection) equaled to 5, 1 and 0.1,respectively, were cultured in differentiation medium. The morphological changes of infected cells were observed under inverted microscope. The ratios of NSCs and its differentiated cells were detected by flow cytometry. The expressions of nestin, GFAP and NSE, markers of NSCs and its differentiated cells, were studied by immunofluorescence(MOI=1). The expression of early antigen(EA) of MCMV was detected to observe the infection process. Real-time RT-PCR method was employed to measure the expression levels of the key genes Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs at early stage of differentiation culture.RESULTS: NSCs isolated from embryonic mouse brains proliferated to form neurospheres, strongly expressed nestin and differentiated into NF-200 positive neurons or GFAP positive astrocytes. The infected NSCs did not adhere to the wall and appeared differentiation growths, but showed swollen gradually after differentiation culture. The nestin expression in the infected cells downregulated slowly and was higher than that in control groups(P<0.05). The GFAP and NSE expressions of the infected cells were lower than those in control groups(P<0.05). The early antigen(EA) of MCMV was always detected in the cells in infected groups. The ratios of nestin positive cells in infected groups were higher than those in control groups, but the ratios of GFAP and NSE positive cells of former were lower than that of the latter from 3rd to 9th d after differentiation culture(P<0.05). The levels of Neurog2 mRNA and Myc mRNA in infected groups were markedly lower than those in normal control groups on 1st d and from 1st to 4th d after differentiation culture, respectively(P<0.05). The levels of Ccnd1 mRNA of infected groups were obviously lower than those in normal control groups from 12th h to 1st d(P<0.05). These changes in infected groups became more obvious as MCMV MOI increased.CONCLUSION: MCMV significantly inhibits differentiation of NSCs to neurons and astrocytes, and leads to the decrease in differentiated cells. MCMV inhibits or interferes with the gene expression of Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs. The effect that MCMV inhibits the expressions of differentiation and the differentiation genes in NSCs shows dose-dependent with MCMV MOI. The inhibitory effect of MCMV on the differentiation of NSCs might be induced by interfering with the expression of differentiation gene in NSCs, which is possibly the one of primary causes of brain development disorders induced by congenital CMV infection.     

聚集器式气力集尘装置几个主要设计参数的合理确定

合理确定聚集器的静压、压力平衡基准、聚集器的压力损失、设计流量等参数，对于保证集尘装置工作的可靠性和经济性都有重要意义。     

重庆市甘规模化猪场猪瘟的诊断

重庆某猪场4头濒死仔猪病理变化疑以猪瘟，病科脾、淋巴结用兔体交互免疫试验检测也为猪瘟阳性。采用中国兽药监察所的猪瘟单抗纯化的强、弱毒抗原酶联免疫吸附试验（ELISA）对该场的母猪及仔猪进行了血清流行病学调查，9.69%（19/196）的母猪及16.83%（33/188）的仔猪血清中即为猪瘟强毒（野毒）抗体阳性，又为猪瘟兔化弱毒抗体阳性。试验结果显示，猪瘟是该场母猪繁殖障碍及仔猪死亡的原因之一。     

基于MODIS数据的冬小麦种植面积快速提取与长势监测

利用MODIS-NDVI数据,以中国冬小麦主产区为例,探讨了基于遥感影像全覆盖的大尺度冬小麦种植面积遥感综合自动识别及长势监测的方法。通过分析冬小麦的种植结构、物候历特征及其生物学特性和时序NDVI曲线特征,确定了冬小麦信息提取的NDVI阈值,建立了冬小麦面积提取模型,并最终获取了2010—2011年中国农情遥感监测中冬小麦长势监测所需的空间分布数据,与多年平均统计数据比较,总体精度达到81%以上。基于提取的冬小麦面积信息空间分布数据,利用MODIS-NDVI差值模型,对冬小麦2011年的长势进行监测。结果表明,与近5年平均状况对比,2011年冬小麦在其整个生育期内长势基本与常年持平,但时空分布差异较大。     

玉米大豆间作对资源利用及产量、效益影响的研究进展

分析了玉米大豆间作条件下,复合群体对光、水、肥等资源的竞争与互补利用,阐述了玉米大豆间作对玉米、大豆产量及系统总产量、经济效益和社会效益的影响,并指出了需进一步研究的问题及方向。     

天津重点水域底栖生物调查分析

于2018年9月,对天津大港,宝坻,华苑等地区的12个站点的大型底栖生物的群落结构及生物多样性进行了调查分析。结果表明,调查区共鉴定出大型底栖生物3门10种,其中软体动物4种,环节动物4种,水生昆虫2种,各站位丰度波动范围为20～840 ind/m^2,平均为205.33 ind/m^2,生物量范围为0.012～308.63 g/m^2,平均为59.69 g/m^2;囊螺为该地区绝对优势种。丰富度指数Margalefs.index在1.48～3.334之间波动, Goodnight修正指数在0.523～1之间波动。     

肉兔不同杂交组合的生产性能试验报告

选择适合本地的3个优良品种及6个杂交组合,探讨不同组合的产仔数、初生窝重、30日龄断奶窝重、30日龄断奶成活率、90日龄成活率、90日龄个体重等生产指标,筛选最优杂交组合。结果表明:肉兔不同品种杂交生产性能明显提高;最优杂交组合为大♀×加♂杂交组合和加♀×新♂杂交组合;6个杂交组合90日龄个体重平均增加109g。