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   5923篇
  免费   410篇
  国内免费   14篇
耳鼻咽喉   62篇
儿科学   275篇
妇产科学   202篇
基础医学   704篇
口腔科学   75篇
临床医学   871篇
内科学   1120篇
皮肤病学   165篇
神经病学   469篇
特种医学   125篇
外科学   612篇
综合类   49篇
一般理论   5篇
预防医学   526篇
眼科学   161篇
药学   425篇
  1篇
中国医学   34篇
肿瘤学   466篇
  2024年   15篇
  2023年   75篇
  2022年   103篇
  2021年   231篇
  2020年   130篇
  2019年   196篇
  2018年   232篇
  2017年   164篇
  2016年   183篇
  2015年   174篇
  2014年   220篇
  2013年   308篇
  2012年   451篇
  2011年   496篇
  2010年   225篇
  2009年   264篇
  2008年   385篇
  2007年   446篇
  2006年   358篇
  2005年   377篇
  2004年   295篇
  2003年   290篇
  2002年   242篇
  2001年   47篇
  2000年   33篇
  1999年   44篇
  1998年   40篇
  1997年   25篇
  1996年   24篇
  1995年   21篇
  1994年   17篇
  1993年   15篇
  1992年   11篇
  1991年   15篇
  1990年   12篇
  1989年   29篇
  1988年   12篇
  1987年   7篇
  1986年   14篇
  1985年   9篇
  1984年   18篇
  1983年   10篇
  1982年   9篇
  1981年   7篇
  1980年   10篇
  1979年   6篇
  1978年   6篇
  1977年   8篇
  1975年   6篇
  1974年   9篇
排序方式: 共有6347条查询结果,搜索用时 0 毫秒
81.
82.
83.
84.
85.
86.
The incidence of lung cancer is rising dramatically and it is now the commonest cause of mortality and morbidity not only in the industrialised countries, but in developing nations like India as well. Tobacco smoking has consistently been demonstrated to be an important aetiological factor, though lung cancer occurs in non-smokers also. In spite of great advances in radiological and molecular diagnostic techniques, the ideal screening marker for early detection of lung cancer has still not been found. Histological diagnosis and staging is essential for selecting the mode of therapy in patients with lung cancer. Stages I and II are amenable to surgery. However, advanced stage III and IV need an individualised combination of surgery, chemotherapy and radiotherapy. With a better understanding of the cellular mechanisms operating in carcinogenesis, newer target specific modalities are being developed and tested in order to stem this disease, which threatens to assume epidemic proportions.  相似文献   
87.
Multiple studies comparing sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in patients with coronary artery disease have been performed. Despite these comparisons, it remains uncertain whether a differential in long-term efficacy and safety exists. Unselected patients treated exclusively with 1 drug-eluting stent type were enrolled in the Registry Experience at the Washington Hospital Center with Drug-Eluting Stents. There were 2,099 patients (3,766 lesions) treated with SES and 1,079 patients (1,850 lesions) treated with PES. Patients were followed at 30 days, 1 year, and 2 years for the clinical endpoints of death, myocardial infarction, target vessel revascularization, and definite and definite/probable stent thrombosis. Patients in the SES group had more dyslipidemia, history of congestive heart failure, and ostial lesions; patients treated with PES had more previous coronary artery bypass surgery, unstable angina, and type C lesions. At 2 years, unadjusted major adverse cardiac events (MACE) (22.6% vs 21.1%, p = 0.3) and target vessel revascularization (13.3% vs 11.2%, p = 0.1) were comparable. The incidence of definite stent thrombosis was higher in the SES group (1.8% vs 0.9%, p = 0.05) driven by early events. Similar results were seen after adjustment for baseline differences: MACE (hazard ratio 1.1, 95% confidence interval [CI] 0.9 to 1.3, p = 0.5), definite stent thrombosis (hazard ratio 2.3, 95% CI 1.0 to 5.2, p = 0.05), and target vessel revascularization (hazard ratio 1.1, 95% CI 0.9 to 1.4, p = 0.4). The incidence and rate of late stent thrombosis (>30 days) were similar (0.7% vs 0.5%, p = 0.4 and 0.24%/year, both groups, respectively). In conclusion, no major differential in long-term safety or efficacy was detected between SES and PES; both stent types were efficacious in reducing revascularization but were limited by a small continual increase in late stent thrombosis.  相似文献   
88.
For patients undergoing elective percutaneous coronary intervention (PCI), procedural anticoagulation with bivalirudin was previously shown to significantly reduce bleeding complications at the cost of a modest increase in ischemic events compared with unfractionated heparin (UFH) and glycoprotein IIb/IIIa inhibitors (GPIs). However, the excess bleeding in patients treated with UFH and GPIs may have been caused by excessively high UFH doses and increased activated clotting times. This study sought to determine the bleeding risk of targeted low-dose UFH with GPIs compared with bivalirudin in patients undergoing elective PCI. Of 1,205 patients undergoing elective PCI, 602 underwent PCI with adjunctive UFH and GPIs with the UFH dose targeted to an activated clotting time of approximately 250 seconds, and 603 patients matched for baseline characteristics underwent PCI with bivalirudin. Outcomes were analyzed for major bleeding (hematocrit decrease >15%, gastrointestinal bleed, or major hematoma) and 6-month major adverse cardiac events (death, myocardial infarction, and target-lesion revascularization). The maximum activated clotting time achieved was 261.7 +/- 61.6 seconds in the UFH/GPI group and 355.4 +/- 66.6 in the bivalirudin group (p <0.001). In-hospital major bleeding rates were similar between groups (1.8% UFH/GPI vs 1.7% bivalirudin; p = 0.83), as were transfusion requirements (1.2% UFH/GPI vs 0.5% bivalirudin; p = 0.61). The 6-month major adverse cardiac event rate was also similar between groups (9.5% UFH/GPI vs 9.0% bivalirudin; p = 0.81). In conclusion, there were no significant differences in major bleeding and 6-month major adverse cardiac events for patients undergoing elective PCI treated with targeted low-dose UFH and GPIs compared with those treated with bivalirudin.  相似文献   
89.
90.
Digestive Diseases and Sciences - While the pathogenesis of inflammatory bowel disease (IBD) is incompletely understood, disruption of epithelial integrity is suspected to play a prominent role in...  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