全文获取类型
收费全文 | 136024篇 |
免费 | 5145篇 |
国内免费 | 823篇 |
出版年
2022年 | 298篇 |
2021年 | 573篇 |
2020年 | 368篇 |
2019年 | 468篇 |
2018年 | 12249篇 |
2017年 | 11077篇 |
2016年 | 8290篇 |
2015年 | 2328篇 |
2014年 | 1976篇 |
2013年 | 2509篇 |
2012年 | 6693篇 |
2011年 | 14933篇 |
2010年 | 13379篇 |
2009年 | 9542篇 |
2008年 | 11560篇 |
2007年 | 13092篇 |
2006年 | 1988篇 |
2005年 | 2190篇 |
2004年 | 2535篇 |
2003年 | 2391篇 |
2002年 | 2148篇 |
2001年 | 1592篇 |
2000年 | 1511篇 |
1999年 | 1229篇 |
1998年 | 657篇 |
1997年 | 631篇 |
1996年 | 620篇 |
1995年 | 587篇 |
1994年 | 548篇 |
1993年 | 596篇 |
1992年 | 1118篇 |
1991年 | 898篇 |
1990年 | 873篇 |
1989年 | 864篇 |
1988年 | 774篇 |
1987年 | 709篇 |
1986年 | 682篇 |
1985年 | 795篇 |
1984年 | 609篇 |
1983年 | 489篇 |
1982年 | 385篇 |
1981年 | 358篇 |
1980年 | 302篇 |
1979年 | 445篇 |
1978年 | 383篇 |
1977年 | 285篇 |
1974年 | 334篇 |
1973年 | 300篇 |
1972年 | 461篇 |
1971年 | 458篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Melissa A. Partridge Sumana Gopinath Simon J. Myers Jens R Coorssen 《Journal of chemical biology》2016,9(1):9-18
An initial proteomic analysis of the cuprizone mouse model to characterise the breadth of toxicity by assessing cortex, skeletal muscle, spleen and peripheral blood mononuclear cells. Cuprizone treated vs. control mice for an initial characterisation. Select tissues from each group were pooled, analysed in triplicate using two-dimensional gel electrophoresis (2DE) and deep imaging and altered protein species identified using liquid chromatography tandem mass spectrometry (LC/MS/MS). Forty-three proteins were found to be uniquely detectable or undetectable in the cuprizone treatment group across the tissues analysed. Protein species identified in the cortex may potentially be linked to axonal damage in this model, and those in the spleen and peripheral blood mononuclear cells to the minimal peripheral immune cell infiltration into the central nervous system during cuprizone mediated demyelination. Primary oligodendrocytosis has been observed in type III lesions in multiple sclerosis. However, the underlying mechanisms are poorly understood. Cuprizone treatment results in oligodendrocyte apoptosis and secondary demyelination. This initial analysis identified proteins likely related to axonal damage; these may link primary oligodendrocytosis and secondary axonal damage. Furthermore, this appears to be the first study of the cuprizone model to also identify alterations in the proteomes of skeletal muscle, spleen and peripheral blood mononuclear cells. Notably, protein disulphide isomerase was not detected in the cuprizone cohort; its absence has been linked to reduced major histocompatibility class I assembly and reduced antigen presentation. Overall, the results suggest that, like experimental autoimmune encephalomyelitis, results from the standard cuprizone model should be carefully considered relative to clinical multiple sclerosis. 相似文献
132.
Two cases of right lower lobe oedema are presented as a supposedly very rare sign of left heart failure after myocardial infarction in the presence of acute mitral regurgitation. Causes of unilateral oedema and its clinical relevance in the diagnostic and therapeutic perspectives are discussed, and a review of the literature on this topic is presented. 相似文献
133.
Tapas K. Nandi Hridoy R. Bairagya Bishnu P. Mukhopadhyay K. Sekar Dipankar Sukul Asim K. Bera 《Journal of biosciences》2009,34(1):27-34
The role of invariant water molecules in the activity of plant cysteine protease is ubiquitous in nature. On analysing the
11 different Protein DataBank (PDB) structures of plant thiol proteases, the two invariant water molecules W1 and W2 (W220
and W222 in the template 1PPN structure) were observed to form H-bonds with the Ob atom of Asn 175. Extensive energy minimization and molecular dynamics simulation studies up to 2 ns on all the PDB and solvated
structures clearly revealed the involvement of the H-bonding association of the two water molecules in fixing the orientation
of the asparagine residue of the catalytic triad. From this study, it is suggested that H-bonding of the water molecule at
the W1 invariant site better stabilizes the Asn residue at the active site of the catalytic triad. 相似文献
134.
135.
136.
137.
138.
A method is described for the histochemical detection of horseradish peroxidase in Paraplast Plus embedded brain sections. The procedure uses 150-micron-thick Vibratome-cut slices of glutaraldehyde-paraformaldehyde-fixed brain tissue. Tetramethylbenzidine stabilized by diaminobenzidine/cobalt/H2O2 is used as chromogen. The Vibratome-cut slices are dehydrated through a graded series of acetone, cleared in toluol and flat-embedded in Paraplast Plus embedding medium. Serial sections can be cut as thin as 5-7 micron. The method is universal in its application and permits optimal visualization of labeled neurons with great morphological detail at the light-microscopic level. 相似文献
139.
140.