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   48045篇
  免费   3494篇
  国内免费   197篇
耳鼻咽喉   570篇
儿科学   1001篇
妇产科学   972篇
基础医学   6679篇
口腔科学   1003篇
临床医学   4755篇
内科学   10094篇
皮肤病学   1078篇
神经病学   4586篇
特种医学   1967篇
外国民族医学   2篇
外科学   8657篇
综合类   483篇
一般理论   76篇
预防医学   2701篇
眼科学   948篇
药学   2844篇
中国医学   75篇
肿瘤学   3245篇
  2023年   467篇
  2022年   920篇
  2021年   1719篇
  2020年   1020篇
  2019年   1349篇
  2018年   1527篇
  2017年   1026篇
  2016年   1207篇
  2015年   1383篇
  2014年   1877篇
  2013年   2184篇
  2012年   3562篇
  2011年   3523篇
  2010年   1958篇
  2009年   1735篇
  2008年   2743篇
  2007年   2788篇
  2006年   2594篇
  2005年   2417篇
  2004年   2230篇
  2003年   2041篇
  2002年   1876篇
  2001年   539篇
  2000年   526篇
  1999年   542篇
  1998年   436篇
  1997年   339篇
  1996年   254篇
  1995年   249篇
  1994年   209篇
  1993年   213篇
  1992年   376篇
  1991年   350篇
  1990年   323篇
  1989年   284篇
  1988年   274篇
  1987年   258篇
  1986年   249篇
  1985年   272篇
  1984年   221篇
  1983年   209篇
  1982年   172篇
  1981年   158篇
  1980年   168篇
  1979年   186篇
  1978年   153篇
  1977年   142篇
  1976年   136篇
  1974年   143篇
  1972年   127篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.

Purpose  

Oral and pharyngeal cancer is the seventh leading tumour in Europe. In Germany, more than 10,000 new cancer cases are diagnosed each year. This population-based project evaluated the available data to develop a more detailed epidemiological profile of oral and pharyngeal cancer.  相似文献   
943.
944.
945.
946.
947.
Telomeres, a validated biomarker of aging, comprise multiple nucleotide repeats capping chromosomes that shorten with each cell cycle until a critical length is achieved, precipitating cell senescence. Only two previous studies focused on the effect of aging in "normal" liver tissue, but these studies were compromised by small sample size, limited age range, tissue derived from individuals with an increased risk of senescence, and the use of liver homogenates. We developed a robust large-volume, four-color quantitative fluorescent in situ hybridization technique to measure telomere length in large numbers of hepatocytes, Kupffer cells, hepatic stellate cells, CD4-positive and CD8-positive lymphocytes, and cholangiocytes. Following validation against the gold standard (Southern blotting), the technique was applied to normal archived paraffin-embedded liver tissue obtained following reperfusion of implanted donor liver. We studied 73 highly selected donors aged 5-79 years with a short medical illness preceding death and no history of liver disease, reperfusion injury, or steatosis and normal graft function 1-year posttransplantation. Cholangiocytes had significantly longer telomeres compared with all other intrahepatic lineages over a wide age range (P < 0.05). Age-related telomere attrition was restricted to sinusoidal cells (i.e., Kupffer cells [P = 0.0054] and stellate cells [P = 0.0001]). Cholangiocytes and hepatocytes showed no age-related telomere shortening. Conclusion: In normal liver and over a broad age range, cholangiocytes have longer telomeres than all other intrahepatic lineages. Age-related telomere length decline is restricted to Kupffer cells and stellate cells. (HEPATOLOGY 2012).  相似文献   
948.
949.
Dronedarone has been associated with a reduced number of first hospitalisation due to acute coronary syndromes. Whether this is only due to the reduction in ventricular heart rate and blood pressure or whether other effects of dronedarone may be involved is currently elusive. This study was designed to investigate the role of dronedarone in arterial thrombus formation. C57Bl/6 mice were treated with dronedarone and arterial thrombosis was investigated using a mouse photochemical injury model. Dronedarone inhibited carotid artery thrombus formation in vivo (P?<?0.05). Thrombin- and collagen-induced platelet aggregation was impaired in dronedarone-treated mice (P?<?0.05), and expression of plasminogen activator inhibitor-1 (PAI1), an inhibitor of the fibrinolytic system, was reduced in the arterial wall (P?<?0.05). In contrast, the level of tissue factor (TF), the main trigger of the coagulation cascade, and that of its physiological inhibitor, TF pathway inhibitor, did not differ. Similarly, coagulation times as measured by prothrombin time and activated partial thromboplastin time were comparable between the two groups. Dronedarone inhibits thrombus formation in vivo through inhibition of platelet aggregation and PAI1 expression. This effect occurs within the range of dronedarone concentrations measured in patients, and may represent a beneficial pleiotropic effect of this drug.  相似文献   
950.
Duarte AG  Myers AC 《Lung》2012,190(1):23-27
Lung transplantation has become the standard of care for particular individuals with advanced lung disease. However, this surgical procedure involves interruption of the lower vagal nerve fibers which leads to loss of the protective cough reflex. Injury of the neural pathways involved with the sensory limb of the cough reflex is associated with an increased risk of complications involving the allograft. While loss of the cough reflex was once considered permanent, recent evidence indicates functional and structural restoration is a time-dependent process that occurs 6–12 months after lung transplantation. The implication that the cough reflex may be reestablished in lung transplant recipients provides insight into the dynamic response to airway neural injury that may lead to improvements in allograft tissue repair.  相似文献   
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