首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   30054篇
  免费   2755篇
  国内免费   723篇
耳鼻咽喉   66篇
儿科学   587篇
妇产科学   114篇
基础医学   1022篇
口腔科学   136篇
临床医学   6010篇
内科学   14874篇
皮肤病学   53篇
神经病学   500篇
特种医学   808篇
外科学   2809篇
综合类   3551篇
现状与发展   1篇
预防医学   431篇
眼科学   405篇
药学   1608篇
  14篇
中国医学   414篇
肿瘤学   129篇
  2024年   10篇
  2023年   682篇
  2022年   656篇
  2021年   1468篇
  2020年   1534篇
  2019年   1594篇
  2018年   1323篇
  2017年   1022篇
  2016年   927篇
  2015年   1027篇
  2014年   2001篇
  2013年   1953篇
  2012年   1403篇
  2011年   1571篇
  2010年   1295篇
  2009年   1314篇
  2008年   1462篇
  2007年   1474篇
  2006年   1156篇
  2005年   1180篇
  2004年   905篇
  2003年   926篇
  2002年   709篇
  2001年   725篇
  2000年   603篇
  1999年   543篇
  1998年   499篇
  1997年   419篇
  1996年   331篇
  1995年   346篇
  1994年   283篇
  1993年   263篇
  1992年   249篇
  1991年   235篇
  1990年   223篇
  1989年   162篇
  1988年   152篇
  1987年   128篇
  1986年   117篇
  1985年   105篇
  1984年   111篇
  1983年   97篇
  1982年   85篇
  1981年   50篇
  1980年   65篇
  1979年   46篇
  1978年   45篇
  1977年   23篇
  1976年   13篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 25 毫秒
91.
Central illustration. Summary of strategies to improve atrial fibrillation (AF) ablation outcomes in obese patients. BMI: body mass index; BS: bariatric surgery; CT: computed tomography; CV: cardiovascular; EAM: electro-anatomical mapping system; EAT: epicardial adipose tissue; MRI: magnetic resonance imaging; NOAC: non-vitamin K antagonist oral anticoagulant; PAF: paroxysmal atrial fibrillation; TOE: transoesophageal echocardiography; TTE: transthoracic echocardiography; US: ultrasound; VKA: vitamin K antagonist.
  相似文献   
92.
93.
94.
95.
Approximately ten per cent of humans are left‐handed or ambidextrous (adextral). It has been suggested that, despite their sizable representation at the whole‐population level, this demographic is largely avoided by researchers within the neuroimaging community. To date, however, no formal effort has been made to quantify the extent to which adextrals are excluded from neuroimaging‐based research. Here, we aimed to address this question in a review of over 1,000 recent articles published in high‐impact, peer‐reviewed, neuroimaging‐focused journals. Specifically, we sought to ascertain whether, and the extent to which adextrals are underrepresented in neuroimaging study samples, and to delineate potential trends in this bias. Handedness data were available for over 30,000 research subjects; only around 3%–4% of these individuals were adextral—considerably less than the 10% benchmark one would expect if neuroimaging samples were truly representative of the general population. This observation was generally consistent across different areas of research, but was modulated by the demographic characteristics of neuroimaging participants. The epistemological and ethical implications of these findings are discussed.  相似文献   
96.
97.
Atrial dysfunction has been widely considered a marker or consequence of other cardiac conditions rather than the cause itself. Here, we propose the term atrial failure as a clinically relevant entity, defined as any atrial dysfunction causing impaired heart performance, symptoms, and worsening quality of life or life expectancy. Aspects of the etiology, mechanisms, and consequences of atrial failure are discussed. Recent advances in cardiac electrophysiology and imaging have improved our understanding of the highly complex atrial anatomy and function, underlying the paramount importance of the atria in optimal heart performance. It is time to reappraise the concept of the failing atrium as a primary cause or aggravating factor of the symptoms in many of our patients. The concept of atrial failure may foster basic and translational research to gain a better understanding of how to identify and manage atrial dysfunction.  相似文献   
98.
99.
100.
BackgroundData on left ventricular (LV) deformation imaging using CT angiography (CTA) are scarce and the feasibility of atrial deformation analysis by CT has not been addressed. We aimed to compare 2D echocardiographic and CT derived LV and left atrial (LA) global longitudinal strain (GLS) obtained by using a novel feature tracking algorithm in patients following transcatheter aortic valve implantation.MethodsTwenty-eight patients were included who underwent retrospectively-gated 256-slice CTA and speckle-tracking echocardiography (STE) on the same day. CT datasets in 10% increments were reconstructed throughout the cardiac cycle. LV GLS and LA global peak reservoir strain (LA GS) was measured.ResultsMedian absolute values for LV GLS were 19.9 [14.8–22.4] vs. 19.9 [16.8–24.7], as measured by CT vs STE, respectively (p = 0.017). We found good inter-modality correlation for LV GLS (ρ = 0.78, p < 0.05) with a mean bias of −1.6. Regarding atrial measurements, the median LA GS was 19.0 [13.5–27.3] for CT vs. 28.0 [17.5–32.6] for STE (p < 0.001) with a mean bias of −5.6 between CT and STE and a correlation coefficient of ρ = 0.87, p < 0.001. CT measurements were highly reproducible: intra-observer intra-class correlation coefficient was 0.96 for LV GLS and 0.95 for LA GS.ConclusionWe detected good correlation between CTA and echocardiography-based LV and LA longitudinal strain parameters. CTA provides accurate strain measurements with high reproducibility. Feature tracking-based deformation analysis could provide a clinically important addition to CT examinations by complementing anatomical information with functional data.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号