全文获取类型
收费全文 | 3692篇 |
免费 | 208篇 |
出版年
2022年 | 30篇 |
2021年 | 77篇 |
2020年 | 38篇 |
2019年 | 55篇 |
2018年 | 67篇 |
2017年 | 73篇 |
2016年 | 97篇 |
2015年 | 133篇 |
2014年 | 148篇 |
2013年 | 182篇 |
2012年 | 259篇 |
2011年 | 223篇 |
2010年 | 140篇 |
2009年 | 115篇 |
2008年 | 182篇 |
2007年 | 145篇 |
2006年 | 136篇 |
2005年 | 119篇 |
2004年 | 103篇 |
2003年 | 80篇 |
2002年 | 91篇 |
2001年 | 88篇 |
2000年 | 63篇 |
1999年 | 68篇 |
1998年 | 30篇 |
1997年 | 29篇 |
1996年 | 26篇 |
1995年 | 25篇 |
1992年 | 50篇 |
1991年 | 61篇 |
1990年 | 45篇 |
1989年 | 55篇 |
1988年 | 39篇 |
1987年 | 49篇 |
1986年 | 34篇 |
1985年 | 74篇 |
1984年 | 48篇 |
1983年 | 53篇 |
1982年 | 24篇 |
1981年 | 29篇 |
1980年 | 41篇 |
1979年 | 53篇 |
1978年 | 33篇 |
1976年 | 25篇 |
1975年 | 27篇 |
1974年 | 32篇 |
1973年 | 28篇 |
1971年 | 34篇 |
1970年 | 29篇 |
1969年 | 33篇 |
排序方式: 共有3900条查询结果,搜索用时 15 毫秒
1.
We present a single-step procedure for the specific mass labeling of unblocked protein N termini. We show that the dye fluorescamine, which is commonly assumed to require mildly alkaline conditions for undergoing a nonspecific reaction with α- and ε-amino groups associated with amino acids, in fact shows a specific reaction only with α-amino groups present at protein N termini when mildly acidic conditions are used. We use this finding to label, identify, and sequence the trypsinolysis-derived N-terminal peptide of lysozyme, using only mass spectrometry, to illustrate how this method could be used with other proteins. 相似文献
2.
Shailesh Kumar Atma P. Dwivedi Vivek Kr. Kashyap A.K. Saxena A.K. Dwivedi Ranjana Srivastava Devi P. Sahu 《Bioorganic & medicinal chemistry letters》2013,23(8):2404-2407
Synthesis of a library of novel trans 6-methoxy-1,1-dimethyl-2-phenyl-3-aryl-2,3-dihydro-1H-inden-4-yloxy alkyl amines and their antimycobacterial activity against drug sensitive and multidrug resistant strains of Mycobacterium tuberculosis have been reported. All the new compounds in the series exhibited MIC between 1.56 and 6.25 μg/ml. Two compounds 1i and 1j with low MIC and low cytotoxicity showed significant reduction in CFU in infected mouse macrophages at 1× MIC concentration. The compound 1i inhibited the growth of M. tuberculosis in mice at 100 mg/kg dose with 1.35 log10 reduction of CFU in lungs tissue and was active against non-replicating Mycobacterium tuberculosis under anaerobic condition. 相似文献
3.
A C Srivastava A J Pinching M W Adler R Robertson R Higgs 《BMJ (Clinical research ed.)》1987,294(6570):495-496
Dr A C Srivastava has written to us to describe a case that raises the suggestion that people infected with the human immuno-deficiency virus (HIV) should carry identity cards. We asked two physicians, a general practitioner working with patients with the acquired immune deficiency syndrome (AIDS), and a general practitioner with a special interest in medical ethics to respond to the broad issues raised by Dr Srivastava''s letter. 相似文献
4.
5.
Molecular and Cellular Biochemistry - 相似文献
6.
7.
8.
9.
10.
A K Srivastava C Pandey K P Dwivedi V K Singh 《Indian journal of biochemistry & biophysics》1989,26(3):199-200
QSAR studies have been performed on the homologues of 3-triazines, using molecular connectivity index and van der Waal volume as structural parameters. The regression analysis has shown good correlation between antitumour activity and the two structural parameters. 相似文献