全文获取类型
收费全文 | 44172篇 |
免费 | 3463篇 |
国内免费 | 231篇 |
专业分类
耳鼻咽喉 | 475篇 |
儿科学 | 1441篇 |
妇产科学 | 882篇 |
基础医学 | 5220篇 |
口腔科学 | 923篇 |
临床医学 | 4431篇 |
内科学 | 9534篇 |
皮肤病学 | 771篇 |
神经病学 | 3661篇 |
特种医学 | 1631篇 |
外科学 | 6736篇 |
综合类 | 932篇 |
一般理论 | 19篇 |
预防医学 | 2991篇 |
眼科学 | 1623篇 |
药学 | 3069篇 |
1篇 | |
中国医学 | 145篇 |
肿瘤学 | 3381篇 |
出版年
2023年 | 304篇 |
2022年 | 516篇 |
2021年 | 1089篇 |
2020年 | 670篇 |
2019年 | 1014篇 |
2018年 | 1183篇 |
2017年 | 816篇 |
2016年 | 973篇 |
2015年 | 1141篇 |
2014年 | 1492篇 |
2013年 | 1791篇 |
2012年 | 2970篇 |
2011年 | 2998篇 |
2010年 | 1745篇 |
2009年 | 1493篇 |
2008年 | 2638篇 |
2007年 | 2567篇 |
2006年 | 2411篇 |
2005年 | 2274篇 |
2004年 | 2135篇 |
2003年 | 1940篇 |
2002年 | 1686篇 |
2001年 | 1308篇 |
2000年 | 1178篇 |
1999年 | 1076篇 |
1998年 | 420篇 |
1997年 | 347篇 |
1996年 | 291篇 |
1995年 | 281篇 |
1994年 | 255篇 |
1993年 | 217篇 |
1992年 | 609篇 |
1991年 | 585篇 |
1990年 | 532篇 |
1989年 | 506篇 |
1988年 | 452篇 |
1987年 | 424篇 |
1986年 | 410篇 |
1985年 | 426篇 |
1984年 | 308篇 |
1983年 | 261篇 |
1982年 | 199篇 |
1981年 | 151篇 |
1980年 | 171篇 |
1979年 | 236篇 |
1978年 | 145篇 |
1977年 | 140篇 |
1976年 | 110篇 |
1974年 | 123篇 |
1973年 | 109篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
PNPLA3 gene polymorphism and response to lifestyle modification in patients with nonalcoholic fatty liver disease 下载免费PDF全文
6.
Tien‐Yao Tsai Iat‐Lon Leong Ka‐Shun Cheng Lian‐Ru Shiao Tzu‐Hui Su Kar‐Lok Wong Paul Chan Yuk‐Man Leung 《Fundamental & clinical pharmacology》2019,33(1):52-62
A pathological feature in atherosclerosis is the dysfunction and death of vascular endothelial cells (EC). Oxidized low‐density lipoprotein (LDL), known to accumulate in the atherosclerotic arterial walls, impairs endothelium‐dependent relaxation and causes EC apoptosis. A major bioactive ingredient of the oxidized LDL is lysophosphatidylcholine (LPC), which at higher concentrations causes apoptosis and necrosis in various EC. There is hitherto no report on LPC‐induced cytotoxicity in brain EC. In this work, we found that LPC caused cytosolic Ca2+ overload, mitochondrial membrane potential decrease, p38 activation, caspase 3 activation and eventually apoptotic death in mouse cerebral bEND.3 EC. In contrast to reported reactive oxygen species (ROS) generation by LPC in other EC, LPC did not trigger ROS formation in bEND.3 cells. Pharmacological inhibition of p38 alleviated LPC‐inflicted cell death. We examined whether heparin could be cytoprotective: although it could not suppress LPC‐triggered Ca2+ signal, p38 activation and mitochondrial membrane potential drop, it did suppress LPC‐induced caspase 3 activation and alleviate LPC‐inflicted cytotoxicity. Our data suggest LPC apoptotic death mechanisms in bEND.3 might involve mitochondrial membrane potential decrease and p38 activation. Heparin is protective against LPC cytotoxicity and might intervene steps between mitochondrial membrane potential drop/p38 activation and caspase 3 activation. 相似文献
7.
8.
Nirmanmoh Bhatia Buddhadeb Dawn Tariq S. Siddiqui Marcus F. Stoddard 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2015,42(1):16-24
Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm2) was underestimated by the standard method (1.05 ± 0.47 cm2; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index. 相似文献
9.
10.