全文获取类型
收费全文 | 2936篇 |
免费 | 158篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 205篇 |
妇产科学 | 94篇 |
基础医学 | 293篇 |
口腔科学 | 59篇 |
临床医学 | 209篇 |
内科学 | 612篇 |
皮肤病学 | 88篇 |
神经病学 | 211篇 |
特种医学 | 151篇 |
外科学 | 396篇 |
综合类 | 99篇 |
预防医学 | 140篇 |
眼科学 | 96篇 |
药学 | 256篇 |
中国医学 | 16篇 |
肿瘤学 | 186篇 |
出版年
2021年 | 51篇 |
2020年 | 36篇 |
2019年 | 50篇 |
2018年 | 58篇 |
2017年 | 29篇 |
2016年 | 34篇 |
2015年 | 41篇 |
2014年 | 83篇 |
2013年 | 89篇 |
2012年 | 129篇 |
2011年 | 137篇 |
2010年 | 80篇 |
2009年 | 76篇 |
2008年 | 94篇 |
2007年 | 122篇 |
2006年 | 111篇 |
2005年 | 108篇 |
2004年 | 86篇 |
2003年 | 101篇 |
2002年 | 91篇 |
2001年 | 81篇 |
2000年 | 70篇 |
1999年 | 77篇 |
1998年 | 75篇 |
1997年 | 57篇 |
1996年 | 64篇 |
1995年 | 48篇 |
1994年 | 39篇 |
1993年 | 38篇 |
1992年 | 51篇 |
1991年 | 61篇 |
1990年 | 57篇 |
1989年 | 54篇 |
1988年 | 52篇 |
1987年 | 40篇 |
1986年 | 49篇 |
1985年 | 45篇 |
1984年 | 41篇 |
1983年 | 37篇 |
1982年 | 27篇 |
1980年 | 37篇 |
1979年 | 44篇 |
1978年 | 25篇 |
1977年 | 34篇 |
1976年 | 25篇 |
1975年 | 25篇 |
1974年 | 39篇 |
1973年 | 30篇 |
1972年 | 20篇 |
1970年 | 21篇 |
排序方式: 共有3130条查询结果,搜索用时 15 毫秒
51.
Douglass A Morrison Gulshan Sethi Jerome Sacks William Henderson Frederick Grover Steven Sedlis Rick Esposito Kodagundi B Ramanathan Darryl Weiman J David Talley Jorge Saucedo Tamim Antakli Venki Paramesh Stuart Pett Sarah Vernon Vladimir Birjiniuk Frederick Welt Mitchell Krucoff Walter Wolfe John C Lucke Sundeep Mediratta David Booth Charles Barbiere Dan Lewis 《Journal of the American College of Cardiology》2002,39(2):266-273
OBJECTIVES: This study was designed to compare the three-year survival after percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG) in physician-directed and patient-choice registries with the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) randomized trial results. BACKGROUND: The AWESOME multicenter randomized trial and registry compared the long-term survival after PCI and CABG for the treatment of patients with medically refractory myocardial ischemia and at least one additional risk factor for adverse outcome with CABG. The randomized trial demonstrated comparable three-year survival. METHODS: Over a five-year period (1995 to 2000), 2,431 patients with medically refractory myocardial ischemia and at least one of five risk factors (prior heart surgery, myocardial infarction within seven days, left ventricular ejection fraction <0.35, age >70 years, intra-aortic balloon required to stabilize) were identified. By physician consensus, 1,650 patients formed a physician-directed registry assigned to CABG (692), PCI (651) or further medical therapy (307), and 781 were angiographically eligible for random allocation; 454 of these patients constitute the randomized trial, and the remaining 327 constitute a patient choice registry. Survival for CABG and PCI was compared using Kaplan-Meier curves and log-rank tests. RESULTS: The CABG and PCI 36-month survival rates for randomized patients were 79% and 80%, respectively. The CABG and PCI 36-month survival rates were both 76% for the physician-directed subgroup; comparable survival rates for the patient-choice subgroup were 80% and 89%, respectively. None of the global log-rank tests for survival demonstrated significant differences. CONCLUSIONS: Both registries support the randomized trial conclusion: PCI is an alternative to CABG for some medically refractory high-risk patients. 相似文献
52.
Specific block of the anti-ischemic actions of cromakalim by sodium 5-hydroxydecanoate 总被引:5,自引:0,他引:5
J R McCullough D E Normandin M L Conder P G Sleph S Dzwonczyk G J Grover 《Circulation research》1991,69(4):949-958
The potassium channel activators cromakalim and pinacidil were recently shown to have anti-ischemic properties in isolated globally ischemic rat hearts. The effects of two reported blockers of ATP-sensitive potassium channels, glibenclamide (glyburide) and sodium 5-hydroxydecanoate, on the anti-ischemic efficacy of cromakalim were determined in this model. Buffer-perfused rat hearts were subjected to 25 minutes of ischemia followed by 30 minutes of reperfusion. Pretreatment of these hearts with 60 microM cromakalim significantly decreased indexes of contractile function but caused a significant improvement of postreperfusion function and a significant decrease in release of lactate dehydroxygenase and in end-diastolic pressure. Pretreatment with glibenclamide at concentrations that reversed the preischemic effects of cromakalim (0.05 and 1.0 microM) also significantly reversed its postischemic protective effects. Sodium 5-hydroxydecanoate (100 and 300 microM) had no effect on the preischemic (negative inotropic) effects of cromakalim but completely reversed its cardioprotective effects. Sodium 5-hydroxydecanoate did not reverse the cardioprotective effects of the calcium entry blocker diltiazem. In phenylephrine-contracted rat aorta, glibenclamide (0.1-10 microM) inhibited cromakalim-induced relaxation, whereas sodium 5-hydroxydecanoate (10-1,000 microM) had no effect. Similarly, the ability of cromakalim to shorten cardiac action potential duration in guinea pig papillary muscle and to increase outward whole-cell potassium currents in isolated myocytes was inhibited by glibenclamide, whereas sodium 5-hydroxydecanoate was without effect. Thus, both glibenclamide and sodium 5-hydroxydecanoate inhibited the effects of cromakalim after reperfusion; however, sodium 5-hydroxydecanoate, unlike glibenclamide, had no effect in nonischemic preparations. These results suggest that sodium 5-hydroxydecanoate is an ischemia-selective inhibitor of ATP-sensitive potassium channels. 相似文献
53.
OBJECTIVE: To forecast the long-term benefits and cost-effectiveness of lipid modification in the secondary prevention of cardiovascular disease. METHODS: A validated model based on data from the Lipid Research Clinics cohort was used to estimate the benefits and cost-effectiveness of lipid modification with 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) based on results from the Scandinavian Simvastatin Survival Study (4S), including a 35% decrease in low-density-lipoprotein (LDL)-cholesterol levels and an 8% increase in high-density-lipoprotein (HDL)-cholesterol levels. After comparing the short-term outcomes predicted for the 4S with the results actually observed, we forecast the long-term risk of recurrent myocardial infarction, congestive heart failure, transient ischemic attacks, arrhythmias, and strokes and the need for surgical procedures such as coronary artery bypass grafting, catheterization, angioplasty, and pacemaker insertions. Outpatient follow-up care costs were estimated, as were the costs of hospital care and drug therapy. All costs were expressed in 1996 US dollars. RESULTS: The short-term outcomes predicted for the 4S were consistent with the observed results. The long-term benefits of lipid modification among low-risk subjects (normotensive nonsmokers) with a baseline LDL/ HDL ratio of 5 but no other risk factors ranged from $5424 to $9548 per year of life saved for men and $8389 to $13747 per year of life saved for women. In high-risk subjects (hypertensive smokers) with an LDL/HDL ratio of 5, the estimated costs ranged from $4487 to $8532 per year of life saved in men and $5138 to $8389 per year of life saved in women. Assuming that lipid modification has no effect on the risk of stroke, cost-effectiveness increased by as much as 100%. CONCLUSIONS: These long-term cost estimates are consistent with the short-term economic analyses of the published 4S results. The long-term treatment of hyperlipidemia in secondary prevention is forecasted to be cost-effective across a broad range of patients between 40 and 70 years of age. Recognizing the additional effects of lipid changes on cerebrovascular events can substantially improve the cost-effectiveness of treating hyperlipidemia. 相似文献
54.
We reviewed the clinical records of 16 patients with polymyositis-dermatomyositis syndromes autopsied at The Johns Hopkins Hospital to determine the nature and extent of cardiac involvement and its correlation with the severity of disease as a whole. The adult patients ranged in age from 32 to 84 years (average 56); the 2 children were aged 2 and 10 years. The duration of disease ranged from 1 to 72 months (average 21). Seven patients had dermatomyositis, 5 had dermatomyositls with malignancy, 2 had childhood dermatomyositis and 2 had an overlap syndrome. Seven patients had clinical evidence of congestive heart failure, 4 of whom had microscopic evidence of myocarditis. Two patients had bundle branch block; in 1 there was direct involvement of the conduction system by myositis and contraction band necrosis. Evidence of active myocarditis was present in 4 patients (25 %); all had congestive failure. Focal myocardial flbrosis was present in 4 patients. Vascular alterations were present in the coronary arteries in 5 patients (31 %). Three had active vasculitis, 1 had Intimai proliferation and 1 had medial sclerosis with calcification. All patients with active myocarditis had skeletal muscle involvement. Nine patients had myositis without myocarditis. There was no correlation of overall severity of the disease with the presence or absence of active myocarditis. The present study shows that cardiac involvement may be common in polymyositis; congestive failure or conduction abnormalities arising in this setting may be indicative of myocarditis. 相似文献
55.
Patade Vikas Yadav Grover Atul Anukriti Gupta Sanjay Mohan Nasim M. 《Proceedings of the National Academy of Sciences, India. Section B.》2021,91(2):407-414
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Our earlier studies have established improved cold tolerance in the transgenic tomato (Solanum lycopersicum... 相似文献
56.
57.
58.
59.
Apurva O. Badheka Neeraj Shah Peeyush M. Grover Nileshkumar J. Patel Ankit Chothani Kathan Mehta Vikas Singh Abhishek Deshmukh Ghanshyambhai T. Savani Ankit Rathod Sidakpal S. Panaich Nilay Patel Shilpkumar Arora Vipulkumar Bhalara James O. Coffey Raul D. Mitrani Jonathan L. Halperin Juan F. Viles-Gonzalez 《The American journal of cardiology》2014
60.