首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   197841篇
  免费   49258篇
  国内免费   1126篇
耳鼻咽喉   3301篇
儿科学   5975篇
妇产科学   2430篇
基础医学   35233篇
口腔科学   7806篇
临床医学   23803篇
内科学   44177篇
皮肤病学   11123篇
神经病学   23134篇
特种医学   9567篇
外科学   29855篇
综合类   614篇
现状与发展   3篇
一般理论   58篇
预防医学   10691篇
眼科学   4460篇
药学   16902篇
中国医学   2298篇
肿瘤学   16795篇
  2023年   708篇
  2022年   2736篇
  2021年   5695篇
  2020年   6902篇
  2019年   13181篇
  2018年   13253篇
  2017年   13770篇
  2016年   15319篇
  2015年   16724篇
  2014年   17635篇
  2013年   19188篇
  2012年   15285篇
  2011年   14789篇
  2010年   14687篇
  2009年   10347篇
  2008年   9585篇
  2007年   8143篇
  2006年   7462篇
  2005年   6735篇
  2004年   5955篇
  2003年   5288篇
  2002年   4720篇
  2001年   3789篇
  2000年   3481篇
  1999年   2402篇
  1998年   954篇
  1997年   711篇
  1996年   550篇
  1995年   483篇
  1994年   420篇
  1993年   357篇
  1992年   774篇
  1991年   730篇
  1990年   655篇
  1989年   570篇
  1988年   477篇
  1987年   478篇
  1986年   352篇
  1985年   383篇
  1984年   266篇
  1983年   206篇
  1982年   142篇
  1981年   179篇
  1980年   136篇
  1979年   227篇
  1978年   165篇
  1976年   134篇
  1975年   121篇
  1974年   142篇
  1973年   125篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
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   
102.
While therapeutic approaches for psoriasis are widely available, preventive regimens are lacking. We aimed to determine whether improvements in epidermal function could prevent psoriasis relapse. Two self‐controlled cohort studies were designed, enrolling two cohorts of patients with psoriasis (n = 30 and n = 60) to be treated topically with an in‐house‐prepared emollient or ATOPALM® cream applied twice daily to one forearm for 20 and 30 days, respectively, while the same sites on the contralateral arm served as the untreated control. Epidermal function on both arms was assessed prior to and at the end of the trials. Delayed relapse on the treated arm was seen in 54.5% and 71% of patients in the first and second cohort, respectively. The time of psoriatic relapse correlated with the extent of abnormalities in baseline epidermal function. These results suggest that improvements in epidermal function with topical emollients can prevent/attenuate the development of psoriasis.  相似文献   
103.
104.
Erythema induratum of Bazin (EIB) is a form of tuberculid resulting from hypersensitivity to tuberculosis antigen. EIB occurs most commonly in middle‐aged women and is not typically seen in children. Here, we present a rare case of EIB, presenting as a chronic nodular panniculitis, in a 10‐year‐old Korean boy.  相似文献   
105.
106.
107.
108.
First described in 1955 in New Jersey, epizootic haemorrhagic disease (EHD) causes a severe clinical disease in wild and domestic ruminants worldwide. Epizootic haemorrhagic disease outbreaks occur in deer populations each year from summer to late autumn. The etiological agent is EHD virus (EHDV) which is a double‐stranded segmented icosahedral RNA virus. EHD virus utilizes point mutations and reassortment strategies to maintain viral fitness during infection. In 2018, EHDV serotype 2 was predominantly detected in deer in Illinois. Whole genome sequencing was conducted for two 2018 EHDV2 isolates (IL41747 and IL42218) and the sequence analyses indicated that IL42218 was a reassortant between different serotypes whereas IL41747 was a genetically stable strain. Our data suggest that multiple strains contribute to outbreaks each year.  相似文献   
109.
110.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号