全文获取类型
收费全文 | 4221篇 |
免费 | 280篇 |
国内免费 | 145篇 |
专业分类
4646篇 |
出版年
2023年 | 41篇 |
2022年 | 69篇 |
2021年 | 91篇 |
2020年 | 93篇 |
2019年 | 115篇 |
2018年 | 128篇 |
2017年 | 107篇 |
2016年 | 104篇 |
2015年 | 146篇 |
2014年 | 405篇 |
2013年 | 517篇 |
2012年 | 279篇 |
2011年 | 161篇 |
2010年 | 147篇 |
2009年 | 210篇 |
2008年 | 210篇 |
2007年 | 190篇 |
2006年 | 153篇 |
2005年 | 159篇 |
2004年 | 115篇 |
2003年 | 128篇 |
2002年 | 99篇 |
2001年 | 66篇 |
2000年 | 58篇 |
1999年 | 33篇 |
1998年 | 56篇 |
1997年 | 33篇 |
1996年 | 41篇 |
1995年 | 39篇 |
1994年 | 40篇 |
1993年 | 39篇 |
1992年 | 61篇 |
1991年 | 29篇 |
1990年 | 38篇 |
1989年 | 25篇 |
1988年 | 33篇 |
1987年 | 21篇 |
1986年 | 37篇 |
1985年 | 75篇 |
1984年 | 43篇 |
1983年 | 48篇 |
1982年 | 42篇 |
1981年 | 33篇 |
1980年 | 28篇 |
1979年 | 16篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1974年 | 6篇 |
排序方式: 共有4646条查询结果,搜索用时 15 毫秒
1.
Xiao‐Juan Yu Xiao‐Ren Peng Tong‐Huan Li 《Journal of cellular and molecular medicine》2014,18(12):2530-2535
Many studies have examined the association between the FABP2 (rs1799883) Ala54Thr gene polymorphism and type 2 diabetes mellitus risk (T2DM) in various populations, but their results have been inconsistent. To assess this relationship more precisely, A HuGE review and meta‐analysis were performed. The PubMed and CNKI database was searched for case‐control studies published up to April 2014. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 13 studies, comprising 2020 T2DM cases and 2910 controls were included. Overall, for the Thr carriers (Ala/Thr and Thr/Thr) versus the wild‐type homozygotes (Ala/Ala), the pooled OR was 1.18 (95% CI = 1.04–1.34, P = 0.062 for heterogeneity), for Thr/Thr versus Ala/Ala the pooled OR was 1.17 (95% CI = 1.05–1.41 P = 0.087 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians but not Caucasians. This meta‐analysis suggests that the FABP2 (rs1799883) Ala54Thr polymorphisms are associated with increased susceptibility to T2DM risk among Asians but not Caucasians. 相似文献
2.
3.
A series of metal carboxylates containing pyridine N-oxide are prepared via one pot synthesis and solid phase synthesis. The structural variations from metal to metal are observed. In the case of reactions of manganese(II) acetate with pyridine N-oxide in the presence of aromatic carboxylic acids, polymeric complexes with bridging aromatic carboxylate as well as bridging pyridine N-oxide are observed. Whereas, the reaction of copper(II) acetate with pyridine N-oxide in the presence of an aromatic carboxylic acid led to mononuclear or binuclear paddle wheel carboxylate complexes with monodentate pyridine N-oxide. Co-crystal of two neutral complexes having composition [Cu2(OBz)4(MeOH)2][Cu2(OBz)4(pyO)2] (where OBz = benzoate, pyO = pyridine N-oxide) each neutral parts have paddle wheel structure. Solid phase reaction of zinc chloride with sodium benzoate prepared in situ and pyridine N-oxide leads to a tetra-nuclear zinc complex. 相似文献
4.
5.
6.
F H Stephenson 《Gene》1985,35(3):313-320
7.
8.
9.
Katharine Y. Ku Fred R. Butcher 《Biochimica et Biophysica Acta (BBA)/General Subjects》1980,631(1):70-78
Calmodulin coupled to Sepharose has provided a rapid and sensitive means of isolating a cyclic nucleotide phosphodiesterase activity which is stimulated by the calmodulin-Ca2+ complex, from rat parotid gland. Initial experiments established that phosphodiesterase activity sensitive to calmodulin and Ca2+ could not be demonstrated in crude extracts of rat parotid gland or after partial purification of rat parotid phosphodiesterase over DEAE-cellulose. However, it was possible to readily demonstrate the presence of a cyclic nucleotide phosphodiesterase activity regulated by calmodulin if the extracts were first purified by batch ion-exchange chromatography over DEAE-cellulose followed by affinity chromatography with calmodulin coupled to Sepharose. The batch ion-exchange chromatography step removed the major portion of free parotid calmodulin which could compete with calmodulin-coupled Sepharose for the proteins regulated by calmodulin. Thus, by employing an initial chromatography step over DEAE-cellulose to separate phosphodiesterase activity from calmodulin, it was possible to increase the recovery of calmodulin-sensitive phosphodiesterase after affinity chromatography with calmodulin coupled to Sepharose. This approach should be useful for demonstrating the presence of and for purifying other parotid proteins regulated by calmodulin. 相似文献
10.
Marjorie Jones Roy W. Keenan 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,678(3):403-407
A procedure was developed for the detection of 2′,3′-cyclic nucleotide 3′-phosphohydrolase in myelin. This assay was sufficiently sensitive to detect the low levels of 2′,3′-cyclic nucleotide 3′-phosphohydrolase in human erythrocytes. The 2′,3′-cyclic nucleotide 3′-phosphohydrolase of human erythrocytes was determined to be exclusively associated with the inner (cytosolic) side of the membrane. Leaky ghostsand resealed ghosts were assayed for 2′,3′-cyclic nucleotide 3′-phosphohydrolase, (Ca2+/Mg2+-ATPase, and acetylcholinesterase activity, and the 2′,3′-cyclic nucleotide 3′-phosphohydrolase profile is the same as that of the (Ca2+/Mg2+)-ATPase, an established inner membrane maker. 相似文献