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排序方式: 共有35条查询结果,搜索用时 15 毫秒
1.
得到并分析了茶刺蛾颗粒体病毒(Darna trima Granulosis Virus缩写为DtGV)病毒粒子的SERS谱.DtGV病毒粒子通过COO(COOH)和NH_2(NH_3)基因被吸附到银溶胶表面上.Trp、Tyr和Phe残基侧链靠近银表面、以Trp残基侧链的振动增强效应最显著.上还增强特性与溶液的pH值密切相关.  相似文献   
2.
植酸对稻米品质影响的研究(Ⅰ)   总被引:2,自引:0,他引:2  
本文报道在水稻生长的抽穗期、齐穗期、灌浆期和蜡熟期喷施不同浓度植酸改良稻米品质的研究。结果表明,在水稻生长的不同阶段,控制喷施植酸浓度可提高糙米率,降低稻米垩白。  相似文献   
3.
Neural stem cells (NSCs) are capable of differentiating into neurons, astrocytes and oligodendrocytes. However, the molecular mechanisms regulating NSCs differentiation are not well understood. Our previous research by microarray analysis certified that a lot of genes are differentially expressed in the course of NSC differentiation. In this study we report the function of one of these genes, BE301622, by RNAi techniques. To silence the BE301622 gene, a long, double-stranded RNA (dsRNA) was synthesized by using a kit (Ambion T7 MegaScript) and transformed into NSCs. Expression of mRNA was tested through RT-PCR. The result showed the expression of BE301622 gene was specificially suppressed. This finding effectively validated that BE301622 is involved in the differentiation of NSCs.  相似文献   
4.
Liao Y  Tang J  Deng Q  Deng Y  Luo T  Wang X  Chen H  Liu T  Chen X  Brody AL  Hao W 《PloS one》2011,6(11):e26460

Background

Cigarette smoking continues to be the leading cause of preventable morbidity and mortality in China and other countries. Previous studies have demonstrated gray matter loss in chronic smokers. However, only a few studies assessed the changes of white matter integrity in this group. Based on those previous reports of alterations in white matter integrity in smokers, the aim of this study was to examine the alteration of white matter integrity in a large, well-matched sample of chronic smokers and non-smokers.

Methodology/Principal Findings

Using in vivo diffusion tensor imaging (DTI) to measure the differences of whole-brain white matter integrity between 44 chronic smoking subjects (mean age, 28.0±5.6 years) and 44 healthy age- and sex-matched comparison non-smoking volunteers (mean age, 26.3±5.8 years). DTI was performed on a 3-Tesla Siemens scanner (Allegra; Siemens Medical System). The data revealed that smokers had higher fractional anisotropy (FA) than healthy non-smokers in almost symmetrically bilateral fronto-parietal tracts consisting of a major white matter pathway, the superior longitudinal fasciculus (SLF).

Conclusion/Significance

We found the almost symmetrically bilateral fronto-parietal whiter matter changes in a relatively large sample of chronic smokers. These findings support the hypothesis that chronic cigarette smoking involves alterations of bilateral fronto-parietal connectivity.  相似文献   
5.
6.

Objective

To compare HCV and HIV infection among heroin addicts in MMT and not in MMT in two large cities in central China.

Methods

A total of 541 heroin addicts were recruited from MMT clinics and voluntary detoxification centers in Changsha and Wuhan, China. Structured questionnaires collected data on their socio-demographics, clinical status, risk behaviors, and their knowledge of HIV. Their HIV serostatus and Hepatitis C virus (HCV) serostatus were determined by testing antibodies in blood serum.

Results

We observed a higher prevalence of HCV infection among MMT heroin addicts (82.3%) than that in the non-MMT group (50.6%). However, our findings indicated that the heroin addicts in MMT had less drug or sexual HIV/HCV risk behaviors and more knowledge about HIV than non-MMT addicts. The heroin addicts in MMT had a significantly higher percentage of individuals who always used condoms (44.9%) compared with patients in the non-MMT group (14.6%, p = 0.039), and they had more knowledge about HIV than non-MMT individuals (p<.001). The percentage of HIV-positive addicts in the MMT group (0.7%) and non-MMT group (0.8%) were almost same.

Conclusion

Our study indicated that the rate of HCV infection among heroin addicts among MMT or non-MMT settings in central China is very high. The non-MMT heroin addicts have higher risk of becoming infected with HCV in the future, while at present they have lower rates of HCV infection than MMT heroin addicts. Although rates of HIV infection among MMT and non-MMT heroin addicts are low now, they are all at great risk of becoming infected with HIV in the future, especially for non-MMT heroin addicts. We should use the MMT sites as a platform to improve the control of HCV and HIV infection in heroin addicts.  相似文献   
7.
Rho-GDIγ belongs to the Rho-GDI protein family, which was observed to have high level expression in the entire brain. Although it exists in neuronal population, its physiological function is poorly understood. This study shows that Rho-GDIγ is a key factor in the G13 signaling pathway based on an analysis of global gene expression. By using RNAi technology to downregulate expression of Rho-GDIγ we found distinct morphological changes in neural stem cell line C17.2. More important, RT-PCR confirmed that RNAi-mediated downregulation of Rho-GDIγ decreased expression of Rho-GDIγ-regulated genes RhoA, Cdc42, Limk2, and N-WASP and slightly increased expression of Rac1. Further, immunochemical staining indicated that downregulation of Rho-GDIγ increased the tendency of C17.2 cells to differentiate. These data strongly suggest that Rho-GDIγ plays a key role in the differentiation of neural stem cells.  相似文献   
8.
Jiang D  Yin C  Yu A  Zhou X  Liang W  Yuan Z  Xu Y  Yu Q  Wen T  Zhang D 《Cell research》2006,16(5):507-518
To understand the expansion ofmulticopy microRNA (miRNA) families in plants, we localized the reported miRNA genes from Arabidopsis and rice to their chromosomes, respectively, and observed that 37% of 117 miRNA genes from Arabidopsis and 35% of 173 miRNA genes from rice were segmental duplications in the genome. In order to characterize whether the expression diversification has occurred among plant multicopy miRNA family members, we designed PCR primers targeting 48 predicted miRNA precursors from 10 families in Arabidopsis and rice. Results from RT-PCR data suggest that the transcribed precursors of members within the same miRNA family were present at different expression levels. In addition, although miRl60 and miR162 sequences were conserved in Arabidopsis and rice, we found that the expression patterns of these genes differed between the two species. These data suggested that expression diversification has occurred in multicopy miRNA families, increasing our understanding of the expression regulation of miRNAs in plants.  相似文献   
9.
Wu Q  Wen T  Lee G  Park JH  Cai HN  Shen P 《Neuron》2003,39(1):147-161
Animals display stereotyped behavioral modifications during development, but little is known about how genes and neural circuits are regulated to turn on/off behaviors. Here we report that Drosophila neuropeptide F (dNPF), a human NPY homolog, coordinates larval behavioral changes during development. The brain expression of npf is high in larvae attracted to food, whereas its downregulation coincides with the onset of behaviors of older larvae, including food aversion, hypermobility, and cooperative burrowing. Loss of dNPF signaling in young transgenic larvae led to the premature display of behavioral phenotypes associated with older larvae. Conversely, dNPF overexpression in older larvae prolonged feeding, and suppressed hypermobility and cooperative burrowing behaviors. The dNPF system provides a new paradigm for studying the central control of cooperative behavior.  相似文献   
10.
耐温酵母与酿酒酵母的属间融合及融合株的高温乙醇发酵   总被引:2,自引:0,他引:2  
利用原生质体融合技术进行耐温的克鲁维酵母(Kluyveromyces Y034)与酿酒酵母(Saccharomyces cereuisiae A001) 的属间融合,获得属间隔合子AY068。该融合株在45℃下进行高温乙酵发酵,结果表明融合株表达了双亲耐温和产酒率高的特性。通过正交试验优化培养基成分,表明蛋东用量对菌体热抗性差异显著。比较了不同温度条件下,菌体生物量、糖利用率、pH因素与酒精产率的  相似文献   
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