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51.
建立基于CRISPR/Cas9的基因转录激活技术,实现在HEK293细胞中激活cGAS基因的转录。首先利用慢病毒载体构建稳定表达Cas9的HEK293细胞;并采用Real-time PCR和western blot方法鉴定Cas9蛋白质表达效果。再选取不同靶序列,分别构建用于激活cGAS基因转录的sgRNA载体,将构建好的序列载体与CRISPR体系工具质粒共转染至稳定表达Cas9的HEK293细胞中。采用Real-time PCR方法检测细胞中内源cGAS的转录激活效果。成功建立了基于CRISPR/Cas9的基因转录激活技术,并在c GAS基因阴性表达的细胞中激活基因的转录。 相似文献
52.
Ruby Yanru Chen-Tsai Ruhong Jiang Luping Zhuang Junfeng Wu Lingsong Li Jiarui Wu 《科学通报(英文版)》2014,59(1):1-6
Transgenic technology allows a gene of interest to be introduced into the genome of a laboratory animal, and provides an extremely powerful tool to dissect the molecular mechanisms of disease. Transgenic mouse models made by microinjection of DNA into zygotic pro- nuclei in particular have been widely used by the genetics community for 30 years. However, it remains a rather crude approach: injected sequences randomly insert in multiple copies as concatamers, they can be mutagenic, and they have variable or silenced expression depending on the site of integration, a phenomenon called position effects. As a result, multiple lines are required in order to confirm appropriate transgene expression. This can be partially overcome by flanking transgenes with insulator sequences to protect the transgene from the influence of the sur- rounding regulatory elements. Large (〈300 kb) BAC- based transgenic vectors have also been shown to be more resistant to position effects. However, animals carrying extra copies of fairly large regions of the genome could have unpredictable phenotypes. The most effective method used to control for position effects is to target transgene insertion to specific genomic loci, the so-called targeted transgenesis; for instance, the fast, site-specific transgenic technology TargattTM. The purpose of this review is to provide an overview on the current existing methods for making targeted transgenic mouse models. 相似文献
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Multisim 9在电子线路课程设计的应用 总被引:1,自引:0,他引:1
结合电子线路课程教学、电子线路课程设计实践,通过二级放大电路实例介绍Multisim 9软件在电子线路课程设计中的应用,该软件能优化电路设计,实现电路功能仿真及提高电路设计开发水平与分析电路的能力。 相似文献
55.
In this article, I examine the historiographical ideas of the historian of chemistry Hélène Metzger (1886–1944) against the background of the ideas of the members of the groups and institutions in which she worked, including Alexandre Koyré, Gaston Bachelard, Abel Rey, Henri Berr and Lucien Febrve. This article is on two interdependent levels: that of particular institutions and groups in which she worked (the Centre de Synthèse, the International Committee for History of Science, the Institut d'Histoire des Sciences et Techniques (Sorbonne) and the École Pratique des Hautes Études) and that of historiographical ideas. I individuate two particular theoretical aspirations pursued by the historians in Metzger's milieu: the ideal of total history and the study of the human mind. These two objectives were seen by Metzger and many others as implicating each other. Moreover, Metzger and other historians wanted to integrate the practice of commentary of texts in the realisations of those ideals. I argue, however, that these objectives proved very difficult to realise at the same time. One tradition which stemmed out of these discussions, exemplified by Bachelard, Canguilhem and Foucault, focused on the mind and knowledge, and renounced commentary of texts and total history as it was understood by the historians of the Centre de Synthèse. The latter, however, did not really pursue the study of the mind. Moreover, historians like Metzger and Koyré who practised an attentive analysis of texts could not realise total history. 相似文献
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针对很多计算机应用场合 ,要求一台计算机具有多种职能 ,需要多种操作系统支持的需求 ,本文讨论了多种操作系统共存于一台计算机中的技术 相似文献
58.
The Sox genes of allotetraploids and their original maternal red crucian carp (Carassius caassius red var.) and original paternal common carp (Cyprinus carpio L.) were detected by PCR with the designed primers based on the conserved HMG-box sequence in different species. Sequencing of Sox genes indicated that two Sox9 genes (Atsox9a and Atsox9b) existed in allotetraploids, while only one Sox9 gene existed in red crucian carp (Rcsox9a) and common carp (Ccsox9b) . All of the four Sox9 genes contained an intron in the HMG-box. with the sizes of 413 bp, 703 bp, 401 bp and 714 bp, respectively. Moreover, the introns obeyed the rule of "GT-AG" . A high similarity was observed between introns of Atsox9a and Rcsox9a (94.4%), Atsox9b and Ccsox9b (97.8%). Interestingly, the deduced amino acid sequences of their corresponding exons all shared 100% identity. Thus, introns of the HMG-domain of Sox9s in allotetraploids and their original parents have not only the length polymorphism but also intron variability. Our results provide significant molecular evidence for the origin and evolution of allotetraploids. 相似文献
59.
介绍了Flash存储器K9F5608U0C和SST39VF160的特性,给出了微处理器LPC2214与它们的硬件连接电路图,以及对它们进行读、写、擦除等操作的应用软件. 相似文献
60.
李益首次从军时间地点考辨 总被引:1,自引:0,他引:1
王胜明 《重庆三峡学院学报》2005,21(2):42-45
本文纠正了长期以来人们对李益首次从军时间和地点的错误认识,认为其首次从军时间应在大历九年至大历十二年间,而非建中初;地点在凤翔节度使李抱玉军中,而非邠宁节度使韩游瑰、凤翔节度使邢君牙或渭北节度使臧希让军中. 相似文献