全文获取类型
收费全文 | 838篇 |
免费 | 120篇 |
出版年
2021年 | 9篇 |
2018年 | 12篇 |
2016年 | 12篇 |
2015年 | 24篇 |
2014年 | 24篇 |
2013年 | 46篇 |
2012年 | 41篇 |
2011年 | 48篇 |
2010年 | 33篇 |
2009年 | 35篇 |
2008年 | 39篇 |
2007年 | 26篇 |
2006年 | 28篇 |
2005年 | 33篇 |
2004年 | 28篇 |
2003年 | 27篇 |
2002年 | 24篇 |
2001年 | 38篇 |
2000年 | 31篇 |
1999年 | 33篇 |
1998年 | 19篇 |
1997年 | 18篇 |
1996年 | 10篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 11篇 |
1992年 | 19篇 |
1991年 | 27篇 |
1990年 | 10篇 |
1989年 | 21篇 |
1988年 | 17篇 |
1987年 | 12篇 |
1986年 | 20篇 |
1985年 | 12篇 |
1984年 | 14篇 |
1983年 | 7篇 |
1982年 | 20篇 |
1981年 | 8篇 |
1979年 | 4篇 |
1978年 | 10篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 4篇 |
1973年 | 9篇 |
1972年 | 7篇 |
1971年 | 16篇 |
1970年 | 4篇 |
1969年 | 7篇 |
1967年 | 3篇 |
排序方式: 共有958条查询结果,搜索用时 46 毫秒
951.
952.
Summary Using anti-somatostatin in an immunoperoxidase technique at the light microscope level, somatostatin-like immunoreactivity was detected in ovine, porcine and rodent pineal glands. Positively stained cell bodies of various sizes and cellular processes were found throughout the glands. The chemical identity of this immunoreactive material and its physiologic significance remain to be determined. 相似文献
953.
Antifolate drug selection results in duplication and rearrangement of chromosome 7 in Plasmodium chabaudi. 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Molecular and cellular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We selected lines of Plasmodium chabaudi that are resistant to high levels of the antifolate drug pyrimethamine and have shown that rearrangement and duplication of a portion of chromosome 7 has occurred in the resistant lines. This chromosomal duplication results in an increase in the chromosome number from 14 to 15: two derived chromosomes (450 kilobases and 1.1 megabases) were smaller than the original chromosome 7 (1.3 megabases), so that essentially only a 200-kilobase region was duplicated. This region contained the DHFR-TS gene and the closely linked Hsp70 gene. We have macrorestriction mapped chromosome 7 from the pyrimethamine-susceptible line (DS) and also the duplicated chromosome 7s in the resistant line. From these maps, we have proposed a process for the karyotype changes. Sequencing of the DHFR gene from the parent and derived chromosomes showed that there were no mutations in the coding sequence. As a result of the duplication of the DHFR-TS gene, there is at least a twofold increase in expression of the DHFR-TS gene, and this may explain the ability of the pyrimethamine-resistant lines to grow in increased amounts of the drug. 相似文献
954.
Archna Ravi Lavinia Palamiuc Ryan M. Loughran Joanna Triscott Gurpreet K. Arora Avi Kumar Vivian Tieu Chantal Pauli Matthias Reist Rachel J. Lew Shauna L. Houlihan Christof Fellmann Christian Metallo Mark A. Rubin Brooke M. Emerling 《Developmental cell》2021,56(11):1661-1676.e10
- Download : Download high-res image (148KB)
- Download : Download full-size image
955.
956.
957.
958.
K. Y. Lee J. Y. Lew D. Tang D. H. Schlesinger A. Y. Deutch M. Goldstein 《Journal of neurochemistry》1989,53(4):1238-1244
A peptide corresponding to position 32-47 in tyrosine hydroxylase was synthesized (TH-16) and polyclonal antibodies against this peptide were raised in rabbits (anti-TH-16). The effects of anti-TH-16 on modulation of tyrosine hydroxylase activity were investigated. Anti-TH-16 enhanced the enzymatic activity in a concentration-dependent manner, and the antigen TH-16 inhibited the stimulatory activity of the antiserum in a concentration-dependent manner. The activated enzyme had a lower Km app for the cofactor 2-amino-4-hydroxy-6-methyl-5,6,7,8-tetrahydropterin and a higher Vmax app than the nonactivated enzyme. Anti-TH-16 was characterized further by its ability to immunoprecipitate the enzyme activity by labeling tyrosine hydroxylase after Western blotting and by immunohistochemical labeling of catecholaminergic neurons. Anti-TH-16 did not block activation of tyrosine hydroxylase by phosphorylation catalyzed by cyclic AMP-dependent protein kinase. Exposure of the enzyme to anti-TH-16 and subsequent phosphorylation of the enzyme resulted in a greater activation of the enzyme than the sum of activation produced by these two treatments separately. However, the activation was less than additive when the enzyme was first phosphorylated and subsequently exposed to anti-TH-16. The present study demonstrates the utility of anti-TH-16 in investigating the molecular aspects of the enzyme activation. 相似文献