全文获取类型
收费全文 | 1211篇 |
免费 | 14篇 |
国内免费 | 49篇 |
出版年
2024年 | 1篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 11篇 |
2019年 | 12篇 |
2018年 | 8篇 |
2017年 | 20篇 |
2016年 | 14篇 |
2015年 | 20篇 |
2014年 | 44篇 |
2013年 | 35篇 |
2012年 | 48篇 |
2011年 | 77篇 |
2010年 | 53篇 |
2009年 | 77篇 |
2008年 | 91篇 |
2007年 | 86篇 |
2006年 | 79篇 |
2005年 | 60篇 |
2004年 | 74篇 |
2003年 | 51篇 |
2002年 | 38篇 |
2001年 | 15篇 |
2000年 | 33篇 |
1999年 | 36篇 |
1998年 | 40篇 |
1997年 | 31篇 |
1996年 | 31篇 |
1995年 | 29篇 |
1994年 | 31篇 |
1993年 | 19篇 |
1992年 | 10篇 |
1991年 | 20篇 |
1990年 | 13篇 |
1989年 | 10篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 2篇 |
排序方式: 共有1274条查询结果,搜索用时 15 毫秒
81.
82.
Genomic structure,gene expression,and promoter analysis of human multidrug resistance-associated protein 7 总被引:1,自引:0,他引:1
The multidrug resistance-associated protein (MRP) subfamily transporters associated with anticancer drug efflux are attributed to the multidrug-resistance of cancer cells. The genomic organization of human multidrug resistance-associated protein 7 (MRP7) was identified. The human MRP7 gene, consisting of 22 exons and 21 introns, greatly differs from other members of the human MRP subfamily. A splicing variant of human MRP7, MRP7A, expressed in most human tissues, was also characterized. The 1.93-kb promoter region of MRP7 was isolated and shown to support luciferase activity at a level 4- to 5-fold greater than that of the SV40 promoter. Basal MRP7 gene expression was regulated by 2 regions in the 5'-flanking region at -1,780-1,287 bp, and at -611 to -208 bp. In Madin-Darby canine kidney (MDCK) cells, MRP7 promoter activity was increased by 226% by genotoxic 2-acetylaminofluorene and 347% by the histone deacetylase inhibitor, trichostatin A. The protein was expressed in the membrane fraction of transfected MDCK cells. 相似文献
83.
84.
85.
86.
87.
88.
Yoshie Matsuda Genqing Liang Yali Zhu Fengshan Ma Richard S. Nelson Biao Ding 《Protoplasma》2002,220(1-2):0051-0058
Summary. Previous work has demonstrated that some endogenous plant gene promoters are active in selective companion cells of the phloem,
depending on organ types and developmental stages. Here we report that the Commelina yellow mottle virus (CoYMV) promoter
is active in the companion cells of leaves, stems and roots of transgenic Nicotiana tabacum cv. Xanthi NN, using β-glucuronidase (GUS) as a reporter. Thus, the CoYMV promoter has a broad organ specificity. This promoter
can be useful in molecular studies on the functions of companion cells in many aspects of phloem biology, such as regulation
of long-distance transport, macromolecular traffic, plant development and interaction with pathogens. It may also be useful
in engineering crops that produce specific gene products in the companion cells to block long-distance movement of pathogens.
Received February 5, 2002; accepted March 27, 2002; published online July 4, 2002
RID="*"
ID="*" Correspondence and reprints: Department of Plant Biology and Plant Biotechnology Center, 207 Rightmire Hall, Ohio State
University, 1060 Carmack Road, Columbus, OH 43210, U.S.A. 相似文献
89.
90.