全文获取类型
收费全文 | 2317篇 |
免费 | 318篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 148篇 |
妇产科学 | 34篇 |
基础医学 | 139篇 |
口腔科学 | 29篇 |
临床医学 | 324篇 |
内科学 | 741篇 |
皮肤病学 | 66篇 |
神经病学 | 223篇 |
特种医学 | 316篇 |
外科学 | 254篇 |
综合类 | 57篇 |
预防医学 | 81篇 |
眼科学 | 35篇 |
药学 | 119篇 |
中国医学 | 3篇 |
肿瘤学 | 88篇 |
出版年
2023年 | 57篇 |
2022年 | 19篇 |
2021年 | 44篇 |
2020年 | 105篇 |
2019年 | 18篇 |
2018年 | 105篇 |
2017年 | 84篇 |
2016年 | 85篇 |
2015年 | 70篇 |
2014年 | 119篇 |
2013年 | 132篇 |
2012年 | 96篇 |
2011年 | 84篇 |
2010年 | 113篇 |
2009年 | 134篇 |
2008年 | 95篇 |
2007年 | 80篇 |
2006年 | 71篇 |
2005年 | 57篇 |
2004年 | 36篇 |
2003年 | 43篇 |
2002年 | 31篇 |
2001年 | 58篇 |
2000年 | 29篇 |
1999年 | 47篇 |
1998年 | 85篇 |
1997年 | 95篇 |
1996年 | 80篇 |
1995年 | 68篇 |
1994年 | 49篇 |
1993年 | 53篇 |
1992年 | 31篇 |
1991年 | 19篇 |
1990年 | 30篇 |
1989年 | 57篇 |
1988年 | 46篇 |
1987年 | 30篇 |
1986年 | 25篇 |
1985年 | 20篇 |
1984年 | 16篇 |
1983年 | 9篇 |
1982年 | 15篇 |
1981年 | 16篇 |
1980年 | 15篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 9篇 |
1971年 | 8篇 |
排序方式: 共有2676条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
Saif S Rathore Andrew J Epstein Brahmajee K Nallamothu Harlan M Krumholz 《Journal of the American College of Cardiology》2006,47(7):1346-1349
A uniform policy for regionalization of ST-segment elevation myocardial infarction (STEMI) care raises several concerns. Transferring all STEMI patients to obtain primary percutaneous coronary intervention (PCI) may be less effective than transferring only high-risk STEMI patients. Delays in time to treatment >60 min associated with transferring patients for primary PCI may result in increased mortality for the average patient as compared with providing immediate fibrinolytic therapy at their initial hospital; yet more than 95% of patients transferred for primary PCI in the U.S. exceed this 60-min benchmark. Superior outcomes associated with treatment at higher-volume regional STEMI centers are inconsistent among centers, and there is no direct evidence that patients will benefit by a transfer to a high-volume hospital from a low-volume hospital. Published data suggest as many as 800 PCI patients would need to be transferred to a high-volume PCI hospital to avoid a single death at a low-volume PCI hospital. Although European randomized trial data suggest transferring patients with STEMI for primary PCI may be superior to immediate fibrinolytic therapy, these findings are unlikely to generalize to the U.S. health care system given size, geography, and organization. ST segment elevation myocardial infarction care regionalization would require a massive redistribution of health care resources, depriving several hospitals of advanced cardiac care facilities, expertise, and associated revenue. Clearer evidence of the benefits and discussion of potential harms are needed before adopting a national STEMI regionalization policy. 相似文献
9.
筛检对肝癌死亡率影响的研究 总被引:5,自引:0,他引:5
5581名HBsAg阳性的男性随机分入周期性筛检组(A组,3712人)及对照组(B组,1869人)。A组(19155.4人年)共发生肝癌257例,B组(9785.5人年)为117例,两组的肝癌发生率分别为1342/10万与1196/10万;两组肝癌死亡分别为218与109例,肝癌死亡率分别为1138/10万与1114/10万。两组中Ⅰ期肝癌病例分别为29.6%与6.0%,差异有非常显著性意义。1、3、5年相对生存率A组为23.7%、7.0%、4.0%,B组为9.7%、4.0%、4.1%。用Poisson回归模型拟合显示,在调正年龄、初筛AFP及入列年份后,筛检对于肝癌的相对危险度为0.83,95%CI为0.68~1.03,有较弱的“保护”作用,Cox回归模型拟合结果显示当临床分期未引入模型时,筛检对于肝癌有显著的“保护”作用:危险率为0.6617,95%CI为0.5234~0.8365;而模型经调整后,危险率即接近“1”,95%CI为0.74~1.26。 相似文献
10.
Ralls PW; Johnson MB; Kanel G; Dobalian DM; Colletti PM; Boswell WD Jr; Radin DR; Halls JM 《Radiology》1986,161(2):451-454
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease. 相似文献