全文获取类型
收费全文 | 589737篇 |
免费 | 72590篇 |
国内免费 | 27446篇 |
学科分类
医药卫生 | 689773篇 |
出版年
2024年 | 1359篇 |
2023年 | 10015篇 |
2022年 | 11903篇 |
2021年 | 23169篇 |
2020年 | 20480篇 |
2019年 | 15819篇 |
2018年 | 21358篇 |
2017年 | 20545篇 |
2016年 | 20515篇 |
2015年 | 27307篇 |
2014年 | 34819篇 |
2013年 | 36342篇 |
2012年 | 40237篇 |
2011年 | 43982篇 |
2010年 | 32955篇 |
2009年 | 30709篇 |
2008年 | 32511篇 |
2007年 | 31944篇 |
2006年 | 31592篇 |
2005年 | 29344篇 |
2004年 | 21883篇 |
2003年 | 20646篇 |
2002年 | 18187篇 |
2001年 | 11997篇 |
2000年 | 10800篇 |
1999年 | 11498篇 |
1998年 | 8777篇 |
1997年 | 8278篇 |
1996年 | 6991篇 |
1995年 | 6464篇 |
1994年 | 5182篇 |
1993年 | 3744篇 |
1992年 | 4081篇 |
1991年 | 3553篇 |
1990年 | 3066篇 |
1989年 | 2845篇 |
1988年 | 2491篇 |
1987年 | 2191篇 |
1986年 | 1947篇 |
1985年 | 1650篇 |
1984年 | 1481篇 |
1983年 | 1445篇 |
1982年 | 1426篇 |
1981年 | 1331篇 |
1980年 | 1166篇 |
1979年 | 792篇 |
1978年 | 797篇 |
1977年 | 812篇 |
1976年 | 649篇 |
1975年 | 566篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Hsiao-Hsuan Kuo Ran Fan Nina Dvorina Andres Chiesa-Vottero William M. Baldwin III 《Journal of the American Society of Nephrology : JASN》2015,26(4):855-863
Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses. 相似文献
93.
94.
95.
96.
97.
98.
Peng Li Sha-Sha Tao Meng-Qin Zhao Jun Li Xiu Wang Hai-Feng Pan 《Immunological investigations》2015,44(7):603-615
Objective: Association of matrix metalloproteinases (MMPs) gene polymorphisms with rheumatoid arthritis is controversial. We conduct a meta-analysis to clarify this dispute.Methods: We systematically searched the electronic PUBMED, EMBASE and CNKI databases for research articles about MMPs (MMP-1, MMP-2, MMP-3, MMP-9) gene polymorphisms and rheumatoid arthritis (RA) up to January 2015. According to the heterogeneity, fixed-effects or random-effects models were used to calculate crude odds ratios (ORs) and 95% confidence intervals (95% CIs).Results: A total of 11 articles involving 2143 cases and 2049 controls were included in this meta-analysis. Overall, no significant associations were observed between MMP-1-1607 1G/2G polymorphism and RA. Stratification by ethnicity, no significant associations were observed in Caucasian populations. Similarly, no significant associations were observed between MMP-3-1171 5A/6A, MMP-9-1562 C/T polymorphisms and RA in overall and Caucasian populations, respectively. However, a weak association was found between MMP-2-1306 C/T polymorphism and RA (C vs. T, OR?=?0.813, 95%CI?=?0.694–0.953, p?=?0.010) in overall populations.Conclusions: The present meta-analysis suggests that MMP-1-1607 1G/2G, MMP-3-1171 5A/6A, MMP-9-1562 C/T polymorphisms are not associated with the susceptibility of RA, but MMP-2 -1306 C/T is weakly associated with susceptibility to RA. Further studies with more sample size are needed for definitive conclusions. 相似文献
99.
100.