全文获取类型
收费全文 | 25289篇 |
免费 | 1412篇 |
国内免费 | 515篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 333篇 |
妇产科学 | 52篇 |
基础医学 | 870篇 |
口腔科学 | 72篇 |
临床医学 | 4058篇 |
内科学 | 7172篇 |
皮肤病学 | 29篇 |
神经病学 | 1061篇 |
特种医学 | 4121篇 |
外科学 | 1872篇 |
综合类 | 3888篇 |
现状与发展 | 1篇 |
预防医学 | 590篇 |
眼科学 | 1407篇 |
药学 | 1149篇 |
11篇 | |
中国医学 | 203篇 |
肿瘤学 | 273篇 |
出版年
2024年 | 57篇 |
2023年 | 467篇 |
2022年 | 875篇 |
2021年 | 1006篇 |
2020年 | 888篇 |
2019年 | 784篇 |
2018年 | 863篇 |
2017年 | 575篇 |
2016年 | 601篇 |
2015年 | 692篇 |
2014年 | 1718篇 |
2013年 | 1465篇 |
2012年 | 1386篇 |
2011年 | 1536篇 |
2010年 | 1345篇 |
2009年 | 1386篇 |
2008年 | 1389篇 |
2007年 | 1433篇 |
2006年 | 1291篇 |
2005年 | 1051篇 |
2004年 | 884篇 |
2003年 | 713篇 |
2002年 | 609篇 |
2001年 | 557篇 |
2000年 | 406篇 |
1999年 | 380篇 |
1998年 | 358篇 |
1997年 | 314篇 |
1996年 | 260篇 |
1995年 | 245篇 |
1994年 | 185篇 |
1993年 | 169篇 |
1992年 | 129篇 |
1991年 | 99篇 |
1990年 | 111篇 |
1989年 | 82篇 |
1988年 | 80篇 |
1987年 | 103篇 |
1986年 | 87篇 |
1985年 | 109篇 |
1984年 | 86篇 |
1983年 | 48篇 |
1982年 | 76篇 |
1981年 | 67篇 |
1980年 | 53篇 |
1979年 | 46篇 |
1978年 | 46篇 |
1977年 | 37篇 |
1976年 | 25篇 |
1975年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
An infant is presented who at birth met criteria consistent with hypoplastic left heart syndrome. He was followed clinically and by 11 weeks of age demonstrated substantial growth of the left ventricle. He underwent successful repair of coarctation of the aorta and continues to do well with moderate aortic stenosis. The difficulties of predicting left ventricular growth and function are discussed, and management options are reviewed. 相似文献
12.
目的:分析血脂代谢异常与冠状动脉狭窄程度的关系.方法:对366例因胸痛而就诊的患者行选择性冠状动脉造影,按冠状动脉狭窄程度分为正常对照组、单支病变组、双支病变组、多支病变组.同时观察患者血脂各成分,并对各组指标进行统计学分析.结果:总胆固醇(TC)、甘油三脂(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C),在各组之间存在差异,尤其多支病变组与正常组之间差异显著(P<0.01).TC、TG、LDL-C随冠状动脉病变加重而增加,HDL-C随冠状动脉病变加重而减少,LDL-C与冠状动脉狭窄程度呈正相关,HDL-C与冠状动脉狭窄程度呈负相关.结论:血脂代谢紊乱与冠状动脉狭窄的发生发展有内在的联系,对于预测有无冠状动脉病变及其进展有一定临床意义. 相似文献
13.
Magnetization prepared segmented acquisition requires a view order that maximizes signal contrast during the acquisition of the central portion of k-space. Steady state free precession (SSFP) acquisition further requires a view order that minimizes changes in phase-encoding gradients from one repetition to the next in order to minimize eddy current artifacts. In this article, optimal view ordering schemes satisfying these two requirements are formulated and applied to inversion prepared 3D SSFP contrast-enhanced MR angiography (MRA). Experiments on phantoms and pigs demonstrated improved background suppression and reduced image artifacts. 相似文献
14.
D. J. Shanley 《Neuroradiology》1992,35(1):55-56
Summary A patient with symptomatic bilateral aberrant cervical internal carotid arteries, demonstrated on CT and MRI, is described. 相似文献
15.
Mark Warner George Eapen George W. Vetrovec 《Catheterization and cardiovascular interventions》1992,25(2):148-150
We describe a patient with two separate vessels having different origins supplying the circumflex coronary artery distribution. This represents a previously undescribed coronary artery anomaly. 相似文献
16.
Gerald Dorros Ruben F. Lewin Lynne Mathiak 《Catheterization and cardiovascular interventions》1988,14(4):286-288
Coronary angioplasty is unsuccessful in <3–5% of cases because the balloon catheter fails to follow a guidewire that has traversed a lesion. Between June 1986 and August 1987, 31 lesions were unable to be crossed with at least two standard angioplasty catheters. Finally, a 2.0-mm-diameter Hartzler LPS (ACS) was utilized and successfully crossed and dilated 16 out of 31 lesions (52%). In the remaining 15 lesions, the ProbeTM (USCI) 2.0 mm diameter × 1.5 cm long balloon wire was able to cross the lesions in 13 (82%) and successfully dilated 12. In one case, lesion rigidity prevented the balloon from expanding at 14 atm. A right coronary artery lesion was attempted in 11 cases, and a left anterior descending and circumflex artery lesion in two patients each. No complications were encountered. In seven out of 12 successful ProbeTM cases, a larger balloon catheter was used to further dilate the artery. This new balloon wire has increased our success rate in severe stenoses and in tortuous vessels with severe distal lesions, in which presently available angioplasty equipment has failed. 相似文献
17.
A 54-year old man presented with multiple pulmonary emboli and an incidental finding of a huge left ventricular thrombus. Transthoracic echo images demonstrated a globally dilated heart with very poor left ventricular function. It was elected to manage the patient medically, and he was commenced on warfarin therapy, resulting in completed resolution of the thrombus over 10 weeks. No underlying cause was found and he did not experience any further embolic events. This illustrates a rare case of a large ventricular thrombus in a patient with no underlying risk factors. 相似文献
18.
George G. Hartnell Francis M. Bradley 《Catheterization and cardiovascular interventions》1993,30(2):101-103
The recommended angiographic projections for optimally demonstrating various cardiac structures vary, and do not always achieve their aim. To determine the most appropriate radiographic projections to optimally demonstrate cardiac structures, we reviewed the orientations of major cardiac structures and the associated great vessels, as demonstrated by axial MRI. Measurements were made from 187 MRI examinations of the heart. These measurements confirmed that the optimum angiographic projections for various cardiac structures are at variance with a number of the recommended views. Recommendations for the angiographic projections most likely to provide optimum display of various cardiac structures and associated great vessels in different patient populations are presented. © 1993 Wiiey-Liss, Inc. 相似文献
19.
We studied retrospectively 12 eyes with a solitary choroidal hemangioma in 12 patients over a period of 13 years. A peculiar, even hyperfluorescence of the tumor within the retinal venous phases occurred in all 12 cases. In all but four patients, laser therapy was performed to reduce subretinal fluid and partially destroy the tumor. Two of the three eyes without extensive retinal detachment or cystoid macular edema at the initial visit regained a final vision of 20/30 or better. The remaining 5 patients with the two major complications had a final vision of 20/80 or worse due to degenerative retinal changes. We believe that laser treatment is definitely advisable in the early stages of a circumscribed choroidal hemangioma.The study was performed at the Institute of Ophthalmology, University of Nijmegen. 相似文献
20.
M. Dujovny K. V. Slavin M. S. Luer G. Hernandez-Avila J. I. Ausman 《Acta neurochirurgica》1995,133(1-2):83-86
Summary Different methods have been used in the evaluation and monitoring of the cerebral oxygen supply during neuro-interventional therapies. Attenuation of near-infrared light by the chromophores oxyhemoglobin and deoxyhemoglobin have shown to be useful in the study of the cellular oxygen metabolism and oxygen delivery to the brain. Transcranial cerebral oximetry (TCCO) has the advantage of providing real-time information regarding regional brain oxygen saturation (rSO2) by using wavelengths in the near-infrared range.We present a patient with a carotid cavernous fistula who underwent balloon occulusion and concurrent continuous TCCO monitoring. TCCO was found to be a useful tool providing immediate rSO2 values during the angiographic and interventional procedures. Initial balloon occlusion of a carotid cavernous fistula resulted in partial occlusion of the internal carotid artery lumen causing an immediate decrease in rSO2 which correlated with angiographic findings. Subsequent reocclusion of the fistula produced a slower and smaller degree of decrease in rSO2 with clinical improvement in the patient. Changes in rSO2 were detected before any adverse clinical event was observed. TCCO was reliable, safe, sensitive, and provided a real-time assessment tool for the monitoring of brain oxygen supply in a patient undergoing a neuroendovascular procedure. 相似文献