全文获取类型
收费全文 | 7633篇 |
免费 | 692篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 110篇 |
儿科学 | 233篇 |
妇产科学 | 254篇 |
基础医学 | 1036篇 |
口腔科学 | 107篇 |
临床医学 | 953篇 |
内科学 | 1767篇 |
皮肤病学 | 162篇 |
神经病学 | 836篇 |
特种医学 | 599篇 |
外科学 | 995篇 |
综合类 | 79篇 |
一般理论 | 1篇 |
预防医学 | 328篇 |
眼科学 | 134篇 |
药学 | 327篇 |
中国医学 | 13篇 |
肿瘤学 | 435篇 |
出版年
2023年 | 66篇 |
2022年 | 59篇 |
2021年 | 112篇 |
2020年 | 143篇 |
2019年 | 92篇 |
2018年 | 172篇 |
2017年 | 133篇 |
2016年 | 158篇 |
2015年 | 192篇 |
2014年 | 267篇 |
2013年 | 336篇 |
2012年 | 349篇 |
2011年 | 341篇 |
2010年 | 294篇 |
2009年 | 273篇 |
2008年 | 322篇 |
2007年 | 340篇 |
2006年 | 352篇 |
2005年 | 303篇 |
2004年 | 264篇 |
2003年 | 246篇 |
2002年 | 225篇 |
2001年 | 258篇 |
2000年 | 228篇 |
1999年 | 191篇 |
1998年 | 152篇 |
1997年 | 139篇 |
1996年 | 138篇 |
1995年 | 122篇 |
1994年 | 86篇 |
1993年 | 101篇 |
1992年 | 137篇 |
1991年 | 133篇 |
1990年 | 131篇 |
1989年 | 149篇 |
1988年 | 133篇 |
1987年 | 104篇 |
1986年 | 82篇 |
1985年 | 91篇 |
1984年 | 70篇 |
1983年 | 48篇 |
1982年 | 45篇 |
1979年 | 68篇 |
1978年 | 39篇 |
1977年 | 48篇 |
1975年 | 39篇 |
1974年 | 44篇 |
1973年 | 45篇 |
1972年 | 46篇 |
1971年 | 44篇 |
排序方式: 共有8369条查询结果,搜索用时 15 毫秒
11.
12.
13.
S A Edlavitch R Crow G L Burke J Huber R Prineas H Blackburn 《Journal of clinical epidemiology》1990,43(1):93-99
One method used to control costs in community cardiovascular disease surveillance is to limit the number of electrocardiograms (ECGs) used to validate acute myocardial infarction (AMI). The Minnesota Heart Survey investigated the impact of decreasing the maximum number of ECGs analyzed on classification of ECG pattern and final AMI diagnosis (definite, probable, none). A 50% sample of all 1980 acute CHD hospital discharge records (ICD-9 code 410 or 411) from 30 of 31 Twin Cities hospitals were abstracted. Comparing results using all available ECGs in the record (maximum of 12) with those obtained using up to 4 ECGs showed little differences in the ECG classification or final AMI diagnosis. 相似文献
14.
15.
16.
Magnetic resonance imaging and clinical correlates of intellectual impairment in myotonic dystrophy 总被引:4,自引:0,他引:4
S J Huber J T Kissel E C Shuttleworth D W Chakeres L E Clapp M A Brogan 《Archives of neurology》1989,46(5):536-540
Although intellectual impairment is common in patients with myotonic dystrophy, this aspect of the disease has received relatively little research attention. We examined 41 patients with myotonic dystrophy using objective neuropsychological procedures and magnetic resonance imaging. Ten patients (24%) had severe and generalized intellectual dysfunction, while lesser or no cognitive impairment characterized the remaining patients. Degree of intellectual impairment was not related to neuromuscular status or sex. Patients with severe intellectual disturbance had significantly earlier onset of both myotonia and weakness and were more likely to inherit the disease from their mother. Magnetic resonance imaging findings indicated that while degree of cerebral atrophy was not related to severity of intellectual impairment, skull thickness, focal white matter lesions, and anterior temporal lobe abnormalities were significantly more common in patients with severely disturbed intellect. This study reports a number of previously unreported cerebral magnetic resonance imaging findings associated with intellectual impairment in myotonic dystrophy, but the etiology of these changes awaits neuropathologic examination. 相似文献
17.
Dr. Carsten Rist T.R. Johnson A. Becker A.W. Leber A. Huber S. Busch C.R. Becker M.F. Reiser K. Nikolaou 《Der Radiologe》2007,47(4):287-294
In a newly developed dual-source computed tomography system (DSCT) the relation of heart rate and image quality and the possible advantages of the system’s superior temporal resolution in the evaluation of left ventricular parameters as compared to results of cardiac magnetic resonance imaging (MRI) were assessed. Coronary CT angiography was performed using a DSCT (Somatom Defintion, Siemens Medical Solutions, Forchheim, Germany) in 21 patients (mean age 62±8; 15 male, 6 female). Image quality of the coronary arteries, the heart valves, and the left ventricular myocardium was assessed using a three-point grading scale. Ten of these patients also underwent cardiac MRI for the assessment of left ventricular function, using a SSFP (steady-state free precession) sequence. Left ventricular ejection fractions (LV-EF), the end-systolic volumes (ESV), and the end-diastolic volumes (EDV) were measured employing MRI and DSCT datasets. The image quality ratings for the coronary arteries at the optimal reconstruction interval were diagnostic even in patients with high heart rates (1.42±0.49). Analysis of global LV function using DSCT quantified from CTA datasets showed a good correlation with results of cardiac MRI [EF: r=0.75 (p=0.01); ESV: r=0.72 (p=0.19); EDV: r=0.71 (p=0.02)]. The dual-source CT system offers robust image quality of the coronary arteries, independent of the heart rate, and provides combined diagnostic imaging of coronary arteries, the heart valves, the myocardium, and the global left ventricular function. 相似文献
18.
19.
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
20.
The fixation of a distally ruptured ulnar collateral ligament of the MP 1 (Metacarpophalangeal) joint without a portion of ligament which can be sutured or a small bony fragment can be accomplished with a variety of methods, most of which require drillholes through borth cortices and a counter incision as well as the removal of the material at a second stage [1, 11, 13, 15]. The Mitek bone mini anchor (Ethicon-Mitek®) proved to be a reliable and quick alternative [10, 12, 16, 18, 19]. It was successfully used in eleven patients with excellent stability of the reconstructed joint. 相似文献