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   132571篇
  免费   5980篇
  国内免费   1069篇
耳鼻咽喉   2430篇
儿科学   1481篇
妇产科学   2265篇
基础医学   20694篇
口腔科学   4664篇
临床医学   12683篇
内科学   18313篇
皮肤病学   4618篇
神经病学   10956篇
特种医学   8149篇
外科学   19161篇
综合类   478篇
一般理论   19篇
预防医学   6609篇
眼科学   3716篇
药学   12546篇
中国医学   2018篇
肿瘤学   8820篇
  2024年   9篇
  2023年   2400篇
  2022年   2658篇
  2021年   5139篇
  2020年   5192篇
  2019年   3151篇
  2018年   4212篇
  2017年   4463篇
  2016年   5074篇
  2015年   6138篇
  2014年   9408篇
  2013年   7611篇
  2012年   11464篇
  2011年   10590篇
  2010年   7564篇
  2009年   6817篇
  2008年   7362篇
  2007年   6709篇
  2006年   5857篇
  2005年   5339篇
  2004年   4439篇
  2003年   3906篇
  2002年   3233篇
  2001年   2982篇
  2000年   2657篇
  1999年   1950篇
  1998年   587篇
  1997年   430篇
  1996年   268篇
  1995年   201篇
  1994年   228篇
  1993年   171篇
  1992年   339篇
  1991年   332篇
  1990年   246篇
  1989年   130篇
  1988年   106篇
  1987年   86篇
  1986年   33篇
  1985年   21篇
  1984年   22篇
  1983年   7篇
  1982年   15篇
  1981年   7篇
  1980年   11篇
  1979年   11篇
  1977年   4篇
  1976年   4篇
  1972年   4篇
  1926年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.  相似文献   
2.
Toxicity resulting from off-target effects, beyond acetylcholine esterase inhibition, for the commonly used organophosphate (OP) insecticides chlorpyrifos (CPS) and malathion (MA) was investigated using Saccharomyces cerevisiae and Caenorhabditis elegans model systems. Mitochondrial damage and dysfunction were observed in yeast following exposure to CPS and MA, suggesting this organelle is a major target. In the C. elegans model, the mitochondrial unfolded protein response pathway showed the most robust induction from CPS and MA treatment among stress responses examined. GABAergic neurodegeneration was observed with CPS and MA exposure. Impaired movement observed in C. elegans exposed to CPS and MA may be the result of motor neuron damage. Our analysis suggests that stress from CPS and MA results in mitochondrial dysfunction, with GABAergic neurons sensitized to these effects. These findings may aid in the understanding of toxicity from CPS and MA from high concentration exposure leading to insecticide poisoning.  相似文献   
3.
BackgroundMain-duct (MD) intraductal papillary mucinous neoplasm (IPMN) is associated with malignancy risk. There is a lack of consensus on treatment (partial or total pancreatectomy) when the MD is diffusely involved. We sought to characterize the pancreatic remnant fate after partial pancreatectomy for non-invasive diffuse MD-IPMN.MethodsConsecutive patients with partial pancreatectomy for non-invasive MD-IPMN from 2004 to 2016 were analyzed. Diffuse MD-IPMN was defined by preoperative imaging as dilation of the MD in the head of the pancreas more than 5 mm and involving the whole gland.ResultsOf 127 patients with resected non-invasive MD-IPMN, 47 (37%) had diffuse MD involvement. Eleven of 47(23%) patients developed imaging evidence of progression or new cystic disease in the pancreatic remnant. Patients with diffuse MD-IPMN were older (73yrs vs 67yrs, p = 0.009), more likely to receive a pancreaticoduodenectomy (96% vs 56%, p < 0.001) and have high-grade dysplasia (51% vs 31%, p = 0.025) than those with focal MD involvement. Diffuse MD involvement was not associated with shorter PFS following partial pancreatectomy (p = 0.613).ConclusionPartial pancreatectomy is an appropriate surgical approach for diffuse MD-IPMN, and is not associated with earlier progression after surgery as compared to partial pancreatectomy for focal dilation.  相似文献   
4.
5.
6.
7.
8.
9.
10.
《Ophthalmology》2022,129(6):597
  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