全文获取类型
收费全文 | 9945篇 |
免费 | 621篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 155篇 |
妇产科学 | 126篇 |
基础医学 | 1235篇 |
口腔科学 | 147篇 |
临床医学 | 952篇 |
内科学 | 2363篇 |
皮肤病学 | 164篇 |
神经病学 | 807篇 |
特种医学 | 447篇 |
外科学 | 1808篇 |
综合类 | 56篇 |
一般理论 | 5篇 |
预防医学 | 873篇 |
眼科学 | 203篇 |
药学 | 621篇 |
中国医学 | 15篇 |
肿瘤学 | 620篇 |
出版年
2023年 | 57篇 |
2022年 | 109篇 |
2021年 | 280篇 |
2020年 | 157篇 |
2019年 | 250篇 |
2018年 | 311篇 |
2017年 | 193篇 |
2016年 | 203篇 |
2015年 | 266篇 |
2014年 | 332篇 |
2013年 | 474篇 |
2012年 | 785篇 |
2011年 | 746篇 |
2010年 | 486篇 |
2009年 | 439篇 |
2008年 | 663篇 |
2007年 | 715篇 |
2006年 | 586篇 |
2005年 | 655篇 |
2004年 | 558篇 |
2003年 | 505篇 |
2002年 | 512篇 |
2001年 | 96篇 |
2000年 | 93篇 |
1999年 | 110篇 |
1998年 | 90篇 |
1997年 | 70篇 |
1996年 | 77篇 |
1995年 | 73篇 |
1994年 | 58篇 |
1993年 | 40篇 |
1992年 | 56篇 |
1991年 | 62篇 |
1990年 | 36篇 |
1989年 | 44篇 |
1988年 | 38篇 |
1987年 | 35篇 |
1986年 | 23篇 |
1985年 | 36篇 |
1984年 | 28篇 |
1982年 | 23篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 22篇 |
1978年 | 11篇 |
1973年 | 12篇 |
1971年 | 12篇 |
1970年 | 13篇 |
1969年 | 14篇 |
1968年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Emmanuel Lansac Isabelle Di Centa Nicolas Bonnet Pascal Leprince Akthar Rama Christophe Acar Alain Pavie Iradj Gandjbakhch 《European journal of cardio-thoracic surgery》2006,29(4):537-544
OBJECTIVE: Dilation of aortic annulus, sinuses of Valsalva, and sinotubular junction (STJ) diameters are the characteristic lesions of aortic root aneurysm. The remodeling technique reduces STJ diameter and creates three neosinuses of Valsalva. Alternatively, the reimplantation technique reduces both annulus and STJ diameters to the detriment of aortic root dynamics. Although the remodeling technique is recognized as the most physiological valve-sparing procedure, aortic annulus dilation may jeopardize its results. A standardized approach that combines an external subvalvular aortic prosthetic ring annuloplasty with the remodeling technique is suggested. METHODS: Eighty-three patients underwent an elective aortic root remodeling procedure, either isolated (group 1, n=34) or combined with an external subvalvular aortic prosthetic ring annuloplasty (group 2, n=49). Preoperative aortic regurgitation was 1.59+/-1.1 (group 1) and 1.97+/-1.3 (group 2) (NS). The aortic annulus was more dilated in group 2 than in group 1 (27+/-2.77 mm vs 26.4+/-2.3 mm, p<0.01). Residual aortic regurgitation > or =grade II was the conversion criteria for aortic valve replacement. RESULTS: Operative mortality was 3.6% (n=3). Intraoperative conversion for valve replacement was 32.7% in group 1 (n=11) versus 4.2% in group 2 (n=2) (p<0.001). In group 1, preoperative annulus diameter was larger for converted than for valve-spared patients (27.6+/-1.7 mm vs 25.2+/-1.5 mm, p<0.02). In group 2, implanted aortic ring significantly reduced annulus diameter (20.6+/-1.8 mm) without significant aortic valve gradient (8.3+/-3 mmHg). Follow-up was 17.2+/-13.4 months (group 1) and 10.41+/-7.95 months (group 2). Reoperation for recurrent aortic regurgitation was 13% in group 1 (n=3) versus 4.2% in group 2 (n=2). Echocardiographic follow-up found residual aortic regurgitation < or =grade I in 17 patients in group 1 (90%) versus 43 patients in group 2 (95.5%) and of grade II in two patients in group 1 (10%) and two patients in group 2 (4.5%). CONCLUSION: The addition of external aortic prosthetic ring annuloplasty improves the remodeling technique's operative reproducibility and short-term results. Therefore, its use as a systematical adjunct to the remodeling procedure is suggested. However, further long-term evaluation comparing this valve-sparing procedure to composite graft replacement should define the best surgical strategy for aortic root aneurysm. 相似文献
12.
Severe hemorrhagic radiation proctitis advancing to gradual cessation with hyperbaric oxygen 总被引:3,自引:0,他引:3
Dr. Jacky Charneau MD Gilles Bouachour MD Bruno Person MD Pascal Burtin MD Jean Ronceray MD Jean Boyer MD 《Digestive diseases and sciences》1991,36(3):373-375
Summary We report a case of a male patient suffering from a severe hemorrhagic radiation proctitis which gradually ceased with hyperbaric oxygen. We discuss the mechanisms of chronic radiation injury and the effect of the hyperbaric oxygen. This therapy is proposed as an alternative to surgical intervention for this abnormality. 相似文献
13.
Imad Ghorayeb MD PhD Anderson Loundou PhD Pascal Auquier MD Yves Dauvilliers MD PhD Bernard Bioulac MD PhD François Tison MD PhD 《Movement disorders》2007,22(11):1567-1572
To determine the prevalence of excessive daytime sleepiness (EDS) and that of dozing and sudden onset of sleep episodes (SOS) while driving in ambulatory patients with Parkinson's disease (PD) in France, a national sample of private and public neurologists was asked to recruit the first 10 consecutive nondemented PD patients. Each patient completed a questionnaire including the Epworth Sleepiness Scale (ESS) and the likelihood of dozing off and experiencing SOS episodes behind the wheel. Clinical and demographic data were collected. One thousand six hundred and twenty‐five patients with PD were included in the survey. Twenty‐nine percent of the patients suffered from EDS (ESS score ≥10) but only 0.8% declared a high chance of dozing while driving and 0.5% reported totally unpredictable SOS episodes while driving. Risk factors for EDS were male gender, reduced activity of daily living, and a high daily levodopa equivalent dosage. Risk factors for SOS episodes while driving were an ESS score ≥10, male gender, and low Hoehn and Yahr staging. EDS is common in ambulatory patients with PD and is a major risk factor for dozing and for SOS episodes behind the wheel in patients who drive. © 2007 Movement Disorder Society 相似文献
14.
15.
16.
Marc Hermier Norbert Nighoghossian Laurent Derex Patrice Adeleine Marlène Wiart Yves Berthezène Fran?ois Cotton Jean-Baptiste Pialat Pascal Dardel Jér?me Honnorat Paul Trouillas Jean-Claude Froment 《Journal of cerebral blood flow and metabolism》2003,23(11):1362-1370
Prediction of hemorrhagic transformation (HT) in patients treated by intravenous recombinant tissue-type plasminogen activator (rt-PA) is a challenging issue in acute stroke management. HT may be correlated with severe hypoperfusion. Signal changes may be observed at susceptibility-weighted magnetic resonance imaging (MRI) within large perfusion defects. A signal drop within cerebral veins at T2*-weighted gradient-echo MRI may be expected in severe ischemia, and may indicate subsequent risk of HT. The authors prospectively searched for an abnormal visibility of transcerebral veins (AVV) within the ischemic area in patients with hemispheric ischemic stroke, before they were treated with intravenous rt-PA therapy. Any correlation between AVV and baseline clinical or MRI findings, or further HT, was noted. An AVV was present in 23 of 49 patients (obvious, n = 8; moderate, n = 15), and was supported by severe hemodynamic changes at baseline MRI. The AVV was correlated with the occurrence of parenchymal hematoma type 2 at computed tomography during the first week (r = 0.44, P = 0.002). Five of six type 2 parenchymal hematomas occurred in association with obvious AVV. At multiple regression analysis, two baseline MRI factors had an independent predictive value for HT risk during the first week: the AVV and the cerebral blood volume ratio (Nagelkerke R2 = 0.48). 相似文献
17.
18.
19.
20.
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