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   305359篇
  免费   16036篇
  国内免费   2150篇
耳鼻咽喉   4558篇
儿科学   8578篇
妇产科学   8292篇
基础医学   43735篇
口腔科学   10714篇
临床医学   21375篇
内科学   66345篇
皮肤病学   8272篇
神经病学   23493篇
特种医学   8246篇
外国民族医学   5篇
外科学   39152篇
综合类   6320篇
一般理论   89篇
预防医学   27296篇
眼科学   7070篇
药学   23285篇
中国医学   1874篇
肿瘤学   14846篇
  2023年   1463篇
  2022年   2110篇
  2021年   5891篇
  2020年   3070篇
  2019年   5712篇
  2018年   8476篇
  2017年   5375篇
  2016年   5218篇
  2015年   5904篇
  2014年   7691篇
  2013年   10776篇
  2012年   16889篇
  2011年   18201篇
  2010年   9716篇
  2009年   7683篇
  2008年   14555篇
  2007年   15379篇
  2006年   14434篇
  2005年   13967篇
  2004年   12683篇
  2003年   11809篇
  2002年   11007篇
  2001年   12009篇
  2000年   12937篇
  1999年   10195篇
  1998年   2869篇
  1997年   2163篇
  1996年   1590篇
  1995年   1455篇
  1994年   1269篇
  1992年   5425篇
  1991年   5186篇
  1990年   4783篇
  1989年   4577篇
  1988年   4343篇
  1987年   4099篇
  1986年   3899篇
  1985年   3674篇
  1984年   2568篇
  1983年   2244篇
  1979年   2347篇
  1978年   1500篇
  1975年   1499篇
  1974年   1768篇
  1973年   1806篇
  1972年   1684篇
  1971年   1620篇
  1970年   1460篇
  1969年   1467篇
  1968年   1342篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
53.
54.
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.  相似文献   
55.
56.
57.
58.
59.
Pseudoaneurysms in the external carotid artery system are rare, mostly reported in the superficial temporal and facial arteries. The bilateral sagittal split osteotomy has a low incidence of complications requiring emergency interventions. We report the case of a patient with acute bleeding from a pseudoaneurysm of the inferior alveolar artery diagnosed by angiography and treated successfully by super-selective embolization.  相似文献   
60.
Background  The data visualization literature asserts that the details of the optimal data display must be tailored to the specific task, the background of the user, and the characteristics of the data. The general organizing principle of a concept-oriented display is known to be useful for many tasks and data types. Objectives  In this project, we used general principles of data visualization and a co-design process to produce a clinical display tailored to a specific cognitive task, chosen from the anesthesia domain, but with clear generalizability to other clinical tasks. To support the work of the anesthesia-in-charge (AIC) our task was, for a given day, to depict the acuity level and complexity of each patient in the collection of those that will be operated on the following day. The AIC uses this information to optimally allocate anesthesia staff and providers across operating rooms. Methods  We used a co-design process to collaborate with participants who work in the AIC role. We conducted two in-depth interviews with AICs and engaged them in subsequent input on iterative design solutions. Results  Through a co-design process, we found (1) the need to carefully match the level of detail in the display to the level required by the clinical task, (2) the impedance caused by irrelevant information on the screen such as icons relevant only to other tasks, and (3) the desire for a specific but optional trajectory of increasingly detailed textual summaries. Conclusion  This study reports a real-world clinical informatics development project that engaged users as co-designers. Our process led to the user-preferred design of a single binary flag to identify the subset of patients needing further investigation, and then a trajectory of increasingly detailed, text-based abstractions for each patient that can be displayed when more information is needed.  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