全文获取类型
收费全文 | 960856篇 |
免费 | 66755篇 |
国内免费 | 4084篇 |
专业分类
耳鼻咽喉 | 13302篇 |
儿科学 | 29843篇 |
妇产科学 | 28220篇 |
基础医学 | 134394篇 |
口腔科学 | 25777篇 |
临床医学 | 81299篇 |
内科学 | 194445篇 |
皮肤病学 | 20134篇 |
神经病学 | 75177篇 |
特种医学 | 38991篇 |
外国民族医学 | 344篇 |
外科学 | 150254篇 |
综合类 | 23158篇 |
现状与发展 | 7篇 |
一般理论 | 258篇 |
预防医学 | 67904篇 |
眼科学 | 21363篇 |
药学 | 68922篇 |
21篇 | |
中国医学 | 3438篇 |
肿瘤学 | 54444篇 |
出版年
2021年 | 7975篇 |
2019年 | 7972篇 |
2018年 | 10996篇 |
2017年 | 8631篇 |
2016年 | 9223篇 |
2015年 | 11000篇 |
2014年 | 15226篇 |
2013年 | 22543篇 |
2012年 | 30386篇 |
2011年 | 31856篇 |
2010年 | 19505篇 |
2009年 | 18350篇 |
2008年 | 29575篇 |
2007年 | 31189篇 |
2006年 | 31177篇 |
2005年 | 30461篇 |
2004年 | 29049篇 |
2003年 | 28094篇 |
2002年 | 27338篇 |
2001年 | 42952篇 |
2000年 | 43902篇 |
1999年 | 37406篇 |
1998年 | 10495篇 |
1997年 | 9571篇 |
1996年 | 9466篇 |
1995年 | 8798篇 |
1994年 | 8405篇 |
1993年 | 7802篇 |
1992年 | 28804篇 |
1991年 | 27462篇 |
1990年 | 26839篇 |
1989年 | 25769篇 |
1988年 | 23916篇 |
1987年 | 23513篇 |
1986年 | 22555篇 |
1985年 | 21400篇 |
1984年 | 16013篇 |
1983年 | 13634篇 |
1982年 | 8185篇 |
1979年 | 14769篇 |
1978年 | 10338篇 |
1977年 | 8718篇 |
1976年 | 8245篇 |
1975年 | 9048篇 |
1974年 | 10781篇 |
1973年 | 10251篇 |
1972年 | 9733篇 |
1971年 | 8982篇 |
1970年 | 8626篇 |
1969年 | 8058篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Kuo-yi Jade Chang MHealthEc MHM BSc Lisa Lorraine Dillon MSpecEd BPsych Lil Deverell COMS PhD MEd GradDipO&M BEd Mei Ying Boon PhD BOptom FAAO Lisa Keay PhD MPH BOptom 《Clinical & experimental optometry》2020,103(4):434-448
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual. 相似文献
2.
Widder Randolf A. Lappas Alexandra Rennings Corinna Hild Matthias Roessler Gernot F. Dietlein Thomas S. 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2020,258(11):2581-2581
Graefe's Archive for Clinical and Experimental Ophthalmology - The published online version contains mistake as the author's first name and last name have been interchanged as "Hild... 相似文献
3.
Timo Rath Lukas Pfeifer Clemens Neufert reas Kremer Moritz Leppkes Arthur Hoffman Markus F Neurath Steffen Zopf 《World journal of gastroenterology : WJG》2020,26(16):1962-1970
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode. 相似文献
4.
5.
6.
Wojciech Szychta M.D. Ph.D. Gheorghe Cerin M.D. Ph.D. F.E.S.C. Bogdan Adrian Popa M.D. Armienti Felice M.D. Guido Lanzillo M.D. Ph.D. Marco Diena M.D. Grzegorz Opolski M.D. Ph.D. F.E.S.C. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(6):1040-1043
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning. 相似文献
7.
8.
9.
10.