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   4223682篇
  免费   353309篇
  国内免费   14617篇
耳鼻咽喉   58665篇
儿科学   137043篇
妇产科学   112523篇
基础医学   650940篇
口腔科学   119022篇
临床医学   381455篇
内科学   759189篇
皮肤病学   105670篇
神经病学   357348篇
特种医学   168495篇
外国民族医学   774篇
外科学   646657篇
综合类   128011篇
现状与发展   23篇
一般理论   2609篇
预防医学   351710篇
眼科学   99216篇
药学   297850篇
  18篇
中国医学   11278篇
肿瘤学   203112篇
  2021年   55659篇
  2019年   58494篇
  2018年   73197篇
  2017年   55670篇
  2016年   61739篇
  2015年   75033篇
  2014年   109507篇
  2013年   174962篇
  2012年   113400篇
  2011年   117070篇
  2010年   123007篇
  2009年   125480篇
  2008年   104238篇
  2007年   109856篇
  2006年   119727篇
  2005年   114565篇
  2004年   116757篇
  2003年   106908篇
  2002年   96437篇
  2001年   149468篇
  2000年   144944篇
  1999年   135449篇
  1998年   70555篇
  1997年   67053篇
  1996年   64977篇
  1995年   60567篇
  1994年   54830篇
  1993年   50948篇
  1992年   101557篇
  1991年   97933篇
  1990年   94473篇
  1989年   92203篇
  1988年   85374篇
  1987年   84308篇
  1986年   79921篇
  1985年   79107篇
  1984年   66676篇
  1983年   59456篇
  1982年   48242篇
  1981年   44925篇
  1980年   42249篇
  1979年   58984篇
  1978年   47646篇
  1977年   42140篇
  1976年   39268篇
  1975年   38667篇
  1974年   43141篇
  1973年   41626篇
  1972年   38595篇
  1971年   35965篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A 20‐year‐old Congolese woman presented with presyncope, dyspnea, and anasarca. Past medical history was unremarkable. Echocardiography revealed a rare combination of giant right atrium (RA), a dilated and hypertrophied right ventricle, subvalvular pulmonary stenosis (subPS), severe tricuspid regurgitation (TR), pericardial effusion and what appeared to be a spontaneously closed ventricular septal defect (VSD). Cardiac Magnetic Resonance and Cardiac Computed Tomography confirmed the findings excluding the presence of intra‐cardiac and extra‐cardiac shunt and other associated congenital anomalies. The patient underwent subPS resection, right atrioplasty, and tricuspid annuloplasty. Multimodality approach facilitated the detection of the abnormalities and provided clarity when determining the optimal surgical strategy.  相似文献   
992.
Women with pre-eclampsia have an increased risk of cardiovascular disease later in life. The aim of the study was to establish the presence and pattern of arterial stiffness in women previously with pre-eclampsia from a semi-rural region of South Africa. This was a prospective longitudinal study which involved 36 previously pre-eclamptic women and 86 non-pregnant controls (NPC) who had a past history of non-complicated pregnancy. Maternal wave reflection (augmentation index) and carotid-femoral pulse wave velocity were assessed noninvasively, using applanation tonometry with the SphygmoCor device. Endothelial function was assessed by EndoPAT 2000 device; pneumatic probes were fitted to the index fingers; induced flow-mediated reactive hyperemia; the ratio of the readings before and after occlusion was then used to calculate the score, the reactive hyperemia index (RHI) as a measure of endothelial function.

Pulse wave velocity remained significantly higher in previously pre-eclamptic women than non-pregnant controls up to three months after delivery (p < 0.05), then it reduced to nonsignificant values. All blood pressure indices (central and brachial pressures), were higher in previously pre-eclamptic women as compared to nonpregnant controls up to one year postpartum.

Regional (aortic) arterial stiffness, though it persists for some time after delivery, is transitory in previously pre-eclamptic women from the rural Africa setting. However, their increase blood pressure is an indication of compromised arterial compliance in women previously with pre-eclampsia.  相似文献   

993.
Background: The opioid addiction and overdose crisis continues to ravage communities across the U.S. Maintenance pharmacotherapy using buprenorphine or methadone is the most effective intervention for Opioid Use Disorder (OUD), yet few have immediate and sustained access to these medications. Objectives: To address lack of medication access for people with OUD, the Missouri Department of Mental Health began implementing a Medication First (Med First) treatment approach in its publicly-funded system of comprehensive substance use disorder treatment programs. Methods: This Perspective describes the four principles of Med First, which are based on evidence-based guidelines. It draws conceptual comparisons between the Housing First approach to chronic homelessness and the Med First approach to pharmacotherapy for OUD, and compares state certification standards for substance use disorder (SUD) treatment (the traditional approach) to Med First guidelines for OUD treatment. Finally, the Perspective details how Med First principles have been practically implemented. Results: Med First principles emphasize timely access to maintenance pharmacotherapy without requiring psychosocial services or discontinuation for any reason other than harm to the client. Early results regarding medication utilization and treatment retention are promising. Feedback from providers has been largely favorable, though clinical- and system-level obstacles to effective OUD treatment remain. Conclusion: Like the Housing First model, Medication First is designed to decrease human suffering and activate the strengths and capacities of people in need. It draws on decades of research and facilitates partnerships between psychosocial and medical treatment providers to offer effective and life-saving care to persons with OUD.  相似文献   
994.
Purpose: Non-ambulatory persons with cerebral palsy are prone to low bone mineral density. In ambulatory persons with cerebral palsy, bone mineral density deficits are expected to be small or absent, but a consensus conclusion is lacking. In this systematic review bone mineral density in ambulatory persons with cerebral palsy (Gross Motor Function Classification Scales I–III) was studied.

Materials and methods: Medline, Embase, and Web of Science were searched. According to international guidelines, low bone mineral density was defined as Z-score?≤??2.0. In addition, we focused on Z-score?≤??1.0 because this may indicate a tendency towards low bone mineral density.

Results: We included 16 studies, comprising 465 patients aged 1–65?years. Moderate and conflicting evidence for low bone mineral density (Z-score?≤??2.0) was found for several body parts (total proximal femur, total body, distal femur, lumbar spine) in children with Gross Motor Function Classification Scales II and III. We found no evidence for low bone mineral density in children with Gross Motor Function Classification Scale I or adults, although there was a tendency towards low bone mineral density (Z-score?≤??1.0) for several body parts.

Conclusions: Although more high-quality research is needed, results indicate that deficits in bone mineral density are not restricted to non-ambulatory people with cerebral palsy.

  • Implications for Rehabilitation
  • Although more high-quality research is needed, including adults and fracture risk assessment, the current study indicates that deficits in bone mineral density are not restricted to non-ambulatory people with CP.

  • Health care professionals should be aware that optimal nutrition, supplements on indication, and an active lifestyle, preferably with weight-bearing activities, are important in ambulatory people with CP, also from a bone quality point-of-view.

  • If indicated, medication and fall prevention training should be prescribed.

  相似文献   
995.
996.
997.
998.
999.
1000.
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