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   226530篇
  免费   10207篇
  国内免费   565篇
耳鼻咽喉   2979篇
儿科学   6847篇
妇产科学   5704篇
基础医学   32510篇
口腔科学   7302篇
临床医学   14351篇
内科学   50838篇
皮肤病学   6945篇
神经病学   18479篇
特种医学   5773篇
外国民族医学   30篇
外科学   27150篇
综合类   1142篇
一般理论   38篇
预防医学   24597篇
眼科学   5305篇
药学   16905篇
  1篇
中国医学   856篇
肿瘤学   9550篇
  2023年   1158篇
  2022年   1697篇
  2021年   4297篇
  2020年   2375篇
  2019年   4380篇
  2018年   6367篇
  2017年   4053篇
  2016年   4188篇
  2015年   4573篇
  2014年   5771篇
  2013年   8492篇
  2012年   13452篇
  2011年   14024篇
  2010年   7443篇
  2009年   6147篇
  2008年   11587篇
  2007年   12261篇
  2006年   11858篇
  2005年   11564篇
  2004年   10673篇
  2003年   9950篇
  2002年   9588篇
  2001年   6851篇
  2000年   7389篇
  1999年   5942篇
  1998年   1528篇
  1997年   1108篇
  1996年   1028篇
  1992年   3117篇
  1991年   2904篇
  1990年   2848篇
  1989年   2485篇
  1988年   2309篇
  1987年   2152篇
  1986年   2160篇
  1985年   2011篇
  1984年   1490篇
  1983年   1299篇
  1979年   1587篇
  1978年   1071篇
  1975年   1152篇
  1974年   1427篇
  1973年   1459篇
  1972年   1374篇
  1971年   1326篇
  1970年   1264篇
  1969年   1325篇
  1968年   1306篇
  1967年   1173篇
  1966年   1068篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
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   
32.
33.
34.
35.
36.
Clinical Oral Investigations - The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of...  相似文献   
37.
Journal of Digital Imaging - Vertebral Compression Fracture (VCF) occurs when the vertebral body partially collapses under the action of compressive forces. Non-traumatic VCFs can be secondary to...  相似文献   
38.
European Journal of Clinical Microbiology & Infectious Diseases - We compared the performance of an in-house-developed flow cytometry assay for intracellular cytokine staining (FC-ICS) and a...  相似文献   
39.
IntroductionPain is highly prevalent in patients with multiple sclerosis (MS); it is chronic in 50% of cases and is classified as nociceptive, neuropathic, or mixed-type. Pain affects quality of life, sleep, and the activities of daily living. Electrotherapy is an interesting alternative or complementary treatment in the management of pain in MS, with new innovations constantly appearing.Material and methodsThis study evaluates the effectiveness of treatment with monopolar dielectric transmission of pulsed electromagnetic fields (PEMF) for pain associated with MS. We performed a randomised, placebo-controlled clinical trial including 24 patients, who were assessed with the Brief Pain Inventory, the Multiple Sclerosis International Quality of Life questionnaire, the Beck Depression Inventory, and the Modified Fatigue Impact Scale.ResultsStatistically significant improvements were observed in maximum and mean pain scores, as well as in the impact of pain on work, personal relationships, and sleep and rest. Not significant differences were found between the treatment and placebo groups.ConclusionsTreatment with PEMF may be effective in reducing pain in patients with MS, although further research is necessary to confirm its effectiveness over placebo and to differentiate which type of pain may be more susceptible to this treatment.  相似文献   
40.
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