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   8602篇
  免费   524篇
  国内免费   26篇
耳鼻咽喉   127篇
儿科学   267篇
妇产科学   266篇
基础医学   895篇
口腔科学   140篇
临床医学   783篇
内科学   2254篇
皮肤病学   80篇
神经病学   842篇
特种医学   329篇
外科学   948篇
综合类   93篇
一般理论   6篇
预防医学   988篇
眼科学   158篇
药学   557篇
中国医学   2篇
肿瘤学   417篇
  2024年   7篇
  2023年   35篇
  2022年   58篇
  2021年   176篇
  2020年   84篇
  2019年   169篇
  2018年   191篇
  2017年   160篇
  2016年   145篇
  2015年   173篇
  2014年   282篇
  2013年   389篇
  2012年   630篇
  2011年   692篇
  2010年   377篇
  2009年   373篇
  2008年   567篇
  2007年   690篇
  2006年   640篇
  2005年   614篇
  2004年   581篇
  2003年   533篇
  2002年   466篇
  2001年   102篇
  2000年   73篇
  1999年   82篇
  1998年   104篇
  1997年   77篇
  1996年   59篇
  1995年   69篇
  1994年   47篇
  1993年   46篇
  1992年   49篇
  1991年   29篇
  1990年   36篇
  1989年   62篇
  1988年   37篇
  1987年   23篇
  1986年   22篇
  1985年   17篇
  1984年   31篇
  1983年   21篇
  1982年   23篇
  1981年   18篇
  1980年   16篇
  1979年   7篇
  1978年   14篇
  1977年   11篇
  1976年   9篇
  1971年   6篇
排序方式: 共有9152条查询结果,搜索用时 0 毫秒
121.
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   
122.
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   
123.
Sirolimus-eluting stents have been used in our institution for all percutaneous interventions, without clinical or anatomic exclusion criteria, as part of the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital registry. We analyzed the incidence of (sub)acute stent thrombosis after sirolimus-eluting stent implantation in an unselected population of 510 consecutive patients. At 3-month follow-up, (sub)acute stent thrombosis was diagnosed in 2 patients (0.4%) 6 hours and 11 days after the procedure, respectively. These cases occurred in diabetic women with complex coronary lesions. Intravascular ultrasound examination showed inadequate stent expansion and uncovered distal dissection as possible mechanical explanations for the thrombosis.  相似文献   
124.
125.
126.
A previous study revealed that the difference in susceptibility to atherosclerotic lesions between inbred mouse strains SM/J and NZB/BlNJ was determined by one major locus (Ath8). In this study a (SM/J x NZB/BlNJ) F(1) x SM/J backcross localized Ath8 by quantitative trait locus mapping to chromosome 4 with a suggestive LOD score of 2.7. This quantitative trait locus (QTL) was confirmed using an (SM/J x NZB/BlNJ) intercross; Ath8 mapped to a 23cM region with a significant LOD score of 3.6. The genes for toll-like receptor 4 (T1r4), arachidonic acid epoxygenase (Cyp2j5), and angiopoietin-like protein 3 (Angptl3) map to this region. These candidate genes were analyzed for expression and sequence differences in the mouse and for associations with cardiovascular traits in human. Sequence analysis of Angptl3 shows a base pair substitution in SM, the susceptible strain, giving rise to an amino acid change in the fibrinogen homology domain of the protein. We found a significant association between ANGPTL3 and atherosclerotic lesions (P < 0.05) in human. These results suggest that Angptl3 is involved in atherosclerosis susceptibility in both mouse and human.  相似文献   
127.
128.
AIMS: To investigate the 'real world' effectiveness of robust statin therapy, focusing on the effect of dose and early treatment discontinuation on the risk of hospitalization for acute myocardial infarction (AMI). METHODS AND RESULTS: In the PHARMO database, including among others drug-dispensing and hospital discharge records for more than two million subjects in the Netherlands, 59,094 new users of statins in the period 1 January 1991 until 31 December 2004, >or=18 years of age were identified. In these patients, exposure to statins, both in terms of persistence and dose, was determined over the first two treatment years. To determine the risk for AMI, patients were followed from this 2-year time point until the first hospital admission for AMI, death, or end of the study period. A total of 31,557 patients (53%) discontinued statin use within 2 years; 20 883 patients (35%) were persistent users with an average equipotent dose>or=4. A 30% reduction in risk of hospitalization for AMI with persistent statin use was observed. The protective effect increased with a higher dose (20 and 40% risk reduction with an equipotent doseor=4, respectively). CONCLUSION: These results show that statins are suboptimally used in real life for having the maximum benefit in terms of preventing AMI.  相似文献   
129.
130.
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