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991.
992.
探讨了利用云南大叶种茶树鲜叶生产名优绿茶-“巴仙银尖”的加工工艺,证明通过合理嫩有,适度摊放,高温杀青,中温慢烘的技术措施,能生产出名优绿茶。文中同时介绍了“巴仙银尖”茶的品质,化学特征。 相似文献
993.
994.
文章首先介绍了蓄电池充放电的特性,接着提出了控制器实现过充和过放所出现的问题,然后提出用斯密特触发器解决过充和过放门限问题,最后给出了施密特触发器的软件实现方案。 相似文献
995.
LUO Dan SHU Sai-nan ZHOU Yu-feng LIU Xing-lou TIAN Jia WANG Hui ZHOU Hua LI Ge FANG Feng 《园艺学报》2009,25(11):2173-2181
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. 相似文献
996.
LI Mei-ai WAN Gen-ping LUO Ming-yong LIANG Xiao-yun ZHAO Xiao-yuan WU Dong-yan ZHANG Xiao-ling 《园艺学报》2009,25(8):1625-1627
AIM: To detect the immunochemically nonreactive urinary albumin and its significance of diagnose on diabetic nephropathy by high performance liquid chromatography (HPLC).METHODS: Urine samples of 58 diabetic children were collected. Urinary albumin was measured by HPLC and by immunoassay respectively.RESULTS: The retention times of albumin of standard and urine samples were 14.3 min. The content of albumin by HPLC and by immunoassay were 9.6-195.1 mg/L and 0-158.6 mg/L, respectively.The level of urinary albumin was higher by HPLC detection than that by immunoassay (P<0.05) in the same sample. The microalbuminuria rates were 70.7% detected by HPLC and 37.9% by immunoassay.CONCLUSION: Total urinary albumin can be measured by HPLC. Microalbuminuria in diabetic children can be observed earlier by HPLC. 相似文献
997.
LUO Lijun MEIHanwei ZHONG Daibin GUOLongbiao WANG Yiping YING Cunshan LI Zhikang XU Jianlong YU Sibin 《水稻科学》2000,8(4)
Lodging resistance has been a key target trait for raising yield potential in rice and it is associated with many component traits such as plant height and stem thickness and strength. etc. While phenotypic selection for lodging resistance has been effective, its genetic basis remains poorly understanding. To understand the genetic basis of stem thickness and strength, and to facilitate genetic improvement of lodging resistance in rice 相似文献
998.
999.
农村产业结构是指一定时期和一定地区范围内,农村各产业部门之间,各产业内部的组合状况和比例关系。对农村产业结构进行调整,就是要建立一个合理的农村产业结构。 相似文献
1000.
罗斌 《农业机械化与电气化》2009,(2):23-24
介绍我国城市绿化养护管理工作的现状.阐述绿化养护管理的重要性,指出城市绿化养护管理工作中存在的一系列问题,并通过分析绿化养护管理工作的特点及主要影响因素.提出做好城市绿化养护管理工作的原则和措施。 相似文献