全文获取类型
收费全文 | 77624篇 |
免费 | 3919篇 |
国内免费 | 1522篇 |
专业分类
耳鼻咽喉 | 127篇 |
儿科学 | 1937篇 |
妇产科学 | 968篇 |
基础医学 | 6113篇 |
口腔科学 | 560篇 |
临床医学 | 9669篇 |
内科学 | 24858篇 |
皮肤病学 | 250篇 |
神经病学 | 1719篇 |
特种医学 | 1752篇 |
外国民族医学 | 1篇 |
外科学 | 9629篇 |
综合类 | 11095篇 |
现状与发展 | 3篇 |
预防医学 | 3223篇 |
眼科学 | 119篇 |
药学 | 6754篇 |
56篇 | |
中国医学 | 3412篇 |
肿瘤学 | 820篇 |
出版年
2024年 | 693篇 |
2023年 | 1334篇 |
2022年 | 2071篇 |
2021年 | 2896篇 |
2020年 | 2958篇 |
2019年 | 2751篇 |
2018年 | 2648篇 |
2017年 | 2196篇 |
2016年 | 2202篇 |
2015年 | 2389篇 |
2014年 | 4935篇 |
2013年 | 5236篇 |
2012年 | 3943篇 |
2011年 | 4731篇 |
2010年 | 3802篇 |
2009年 | 3852篇 |
2008年 | 3733篇 |
2007年 | 3682篇 |
2006年 | 3388篇 |
2005年 | 3104篇 |
2004年 | 2453篇 |
2003年 | 2184篇 |
2002年 | 1735篇 |
2001年 | 1662篇 |
2000年 | 1283篇 |
1999年 | 1104篇 |
1998年 | 884篇 |
1997年 | 874篇 |
1996年 | 780篇 |
1995年 | 731篇 |
1994年 | 689篇 |
1993年 | 550篇 |
1992年 | 530篇 |
1991年 | 473篇 |
1990年 | 404篇 |
1989年 | 406篇 |
1988年 | 394篇 |
1987年 | 308篇 |
1986年 | 268篇 |
1985年 | 309篇 |
1984年 | 293篇 |
1983年 | 209篇 |
1982年 | 235篇 |
1981年 | 232篇 |
1980年 | 240篇 |
1979年 | 204篇 |
1978年 | 180篇 |
1977年 | 154篇 |
1976年 | 153篇 |
1975年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
川芎嗪和维拉帕米对缺血性急性肾衰初期保护效应的实验研究 总被引:5,自引:0,他引:5
18只犬切除右肾,钳夹左肾动脉60分的肾缺血模型,再灌注5小时。将动物随机分成对照组、川芎嗪组及维拉帕米组。观察尿量、菊糖清除率、利钠指数、平均动脉压及心率;再灌注5小时取肾组织作形态学检查。结果显示川芎嗪对肾功能及形态有保护作用,维拉帕米则无此作用,提示在手术中有肾缺血时以川芎嗪作为肾保护药物优于维拉帕米。 相似文献
42.
43.
M. Estryn-Behar B. Kapitaniak M. C. Paoli E. Peigne A. Masson 《International archives of occupational and environmental health》1992,64(2):131-139
Summary The aim of this study was to evaluate the level of physical capacity in a female hospital population of Paris and its suburbs. A total of 1505 women working in the selected departments filled in a questionnaire concerning their working conditions, life habits and health and also attended a medical examination. The effort test performed consisted in flexing the legs 20 times with the chest held straigt, in 40 s. The heart rates were measured for the first, the second and the third minutes of recovery (first 15 s multiplied by 4). The blood pressure was measured just after the heart rate, for the first and the third minute. Recovery indices have been constituted from the results. The respective weights of anthropometric and sociodemographic risk factors for recovery indices were studied in multiple logistic regression models. The classification enables us to consider about 25%–30% of our population as having a satisfactory physical capacity, about 26%–27% as having an acceptable capacit, and about 24%–27% as having a weak capacity. About 21% of the population presented an excessive pressure reaction and 44% a questionable pressure reaction. Our results concerning the level of physical capacity of the female nursing staff should be taken into account especially in the future planning of work loads and architectural choices, which must avoid excessive physical burdens in relation to this level. An improvement in the level of physical capacity could be envisaged as well. 相似文献
44.
The non-sulfhydryl selective angiotensin-converting enzyme inhibitor benazepril (20 mg daily) was compared with hydrochlorothiazide (50 mg daily) in post-infarction (6-24 months) patients with symptomatic (NYHA functional class 2) mild heart failure. No concomitant drug therapy was given. The study had a double-blind cross-over design with 3-month treatment periods. Both drugs were well tolerated, and both caused a similar reduction in systolic blood pressure. Heart rate was higher with the diuretic. Benazepril improved the NYHA functional class in 17 out of 29 (59%) patients, whereas one patient improved with hydrochlorothiazide (P = 0.0004). With regard to global efficacy score, benazepril was also superior. Thus, angiotensin-converting enzyme inhibitors may be superior to diuretics as first-choice therapy in symptomatic mild heart failure. 相似文献
45.
Yusuke Ando Takahiro Nishida Shigeki Morita Munetaka Masuda Yukihiro Tomita Ryuji Tominaga 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(8):335-337
Infective endocarditis of the mitral area accompanied by anorexia nervosa is extremely rare. A 34-year-old Japanese woman presented with high fever and a heart murmur that had developed over the previous 2-month period. Echocardiography revealed mitral regurgitation and vegetation attached to the anterior mitral leaflet, which had markedly prolapsed to the left atrium. We removed the vegetation with a small part of the anterior mitral leaflet and successfully repaired the mitral valve. The patient showed good recovery, and the mitral regurgitation and left ventricular chamber size had satisfactorily decreased at 2 months after the operation. 相似文献
46.
Vanishing fluid collections in interlobar fissures, associated with congestive cardiac failure, are uncommon but well-recognized. Previous studies have highlighted the occurrence of solitary vanishing ‘tumours’, but in the study reported here 7 out of 12 consecutive patients presented with more than one interlobar fluid collection simulating pulmonary tumours. In most cases a lateral radiograph confirmed the correct diagnosis and in all cases follow-up radiographs demonstrated resolution of all pleural fluid collections. In one case ultrasound was helpful. Making the correct diagnosis is very important inorder to prevent inappropriate investigations and treatment such as biopsy or surgery. It is suggested that unusual pleural fluid collections may be more common in communities where pleural disease following stab wounds or tuberculosis are more prevalent. 相似文献
47.
本文报告65例双炔失碳酯配伍d1-15甲基PGF_(2α)(以下简称PG)抗早孕结果并与33例丙睾配伍PG抗早孕结果进行比较。结果显示,双炔失碳酯组完全流产59例,占90%;不全流产3例,占5%;失败3例,占5%;总有效率95%。丙睾组完全流产27例,占82%;不全流产6例,占18%;总有效率100%。两组总有效率无显著差异;完全流产率无显著差异;但不全流产率有明显差异(P<0.05)。药流后点滴出血天数,双炔失碳酯组平均为8.1±5.0天;丙睾组平均为18.9±19.1天;两组有明显差别(P<0.05)。双炔失碳酯经阴道给药后无一例发生心、肝、肾功能变化。 相似文献
48.
K. Groeneveld A. H. M. M. Balk A. J. Ouwehand E. H. M. Loonen M. vd Linden S. Strikwerda B. Mochtar N. H. P. M. June W. Weimar 《Transplant international》1992,5(Z1):S228-S230
Chronic rejection (CR) is a major problem in long-term survival in heart transplantation. We analysed whether the occurrence of CR correlates with the incidence of acute rejections (AR) or with characteristics of endomyocardial biopsy-derived cell cultures. CR was diagnosed by annual angiography and defined as all coronary vascular changes. One year after transplantation 24 of the 63 patients had CR (38%). The incidence of AR in CR + and CR — patients was comparable. The patients in both groups had similar individual median percentages of EMB-yielding cell cultures. During the first year the CR — patients had more cultures in which at least 60% of the cells were CD4 + T cells (50% vs 37%, P = 0.05), due to a stronger CD4 predominance in the first 6 months. In the second year the CD4 predominance in the patients diagnosed as CR + after 1 year tended to be higher (P = 0.08). The patients had comparable percentages of cultures predominated by CD8 + T cells, γδ T cells or NK cells, irrespective of the time interval. These results might indicate that CD4 + T lymphocytes play a dual role in the aetiology of CR. 相似文献
49.
Ischemic postconditioning: brief ischemia during reperfusion converts persistent ventricular fibrillation into regular rhythm 总被引:31,自引:0,他引:31
Michael Galagudza Dmitry Kurapeev Sarkis Minasian Guro Valen Jarle Vaage 《European journal of cardio-thoracic surgery》2004,25(6):406-1010
Objectives: Brief episodes of myocardial ischemia-reperfusion employed during reperfusion after a prolonged ischemic insult may attenuate the total ischemia-reperfusion injury. This phenomenon has been termed ischemic postconditioning. In the present study, we studied the possible effect of postconditioning on persistent reperfusion-induced ventricular fibrillation (VF) in the isolated rat heart model. Methods: Isolated Langendorff-perfused rat hearts (n=46) were subjected to 30 min of regional ischemia and reperfusion. The hearts with persistent VF (n=11) present after 15 min of reperfusion were then randomly assigned into one of the two groups: (1) control hearts (n=6), in which perfusion was continued without intervention; (2) postconditioned hearts (n=5) subjected to 2 min of global ischemia followed by reperfusion. Left ventricular pressures, heart rate, coronary flow, and electrogram were monitored throughout the experiment. Results: Conversion of VF into regular rhythm was observed in all hearts subjected to postconditioning. Regular beating was maintained by all postconditioned hearts during the subsequent reperfusion. None of the hearts in the control group had normal rhythm at the end of the experiment. At the end of reperfusion, the left ventricular developed pressure was lower in beating postconditioned hearts compared to the hearts that did not develop persistent VF. Conclusions: Ischemic postconditioning possesses strong antiarrhythmic effect against persistent reperfusion-induced tachyarrhythmias. Postconditioning may be an interesting, novel adjunct strategy to protect the heart. 相似文献
50.