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   2648236篇
  免费   193681篇
  国内免费   5141篇
耳鼻咽喉   36521篇
儿科学   88536篇
妇产科学   72706篇
基础医学   374735篇
口腔科学   74800篇
临床医学   236470篇
内科学   519871篇
皮肤病学   59256篇
神经病学   206315篇
特种医学   102472篇
外国民族医学   868篇
外科学   404127篇
综合类   59575篇
现状与发展   5篇
一般理论   849篇
预防医学   198499篇
眼科学   61767篇
药学   194632篇
  8篇
中国医学   6075篇
肿瘤学   148971篇
  2019年   20074篇
  2018年   29060篇
  2017年   21977篇
  2016年   24180篇
  2015年   27490篇
  2014年   38259篇
  2013年   56917篇
  2012年   78536篇
  2011年   82956篇
  2010年   49455篇
  2009年   46545篇
  2008年   78036篇
  2007年   83170篇
  2006年   83909篇
  2005年   80712篇
  2004年   78463篇
  2003年   75157篇
  2002年   72940篇
  2001年   133968篇
  2000年   137673篇
  1999年   115468篇
  1998年   30900篇
  1997年   27378篇
  1996年   27698篇
  1995年   26500篇
  1994年   24645篇
  1993年   22771篇
  1992年   89366篇
  1991年   86813篇
  1990年   83942篇
  1989年   80472篇
  1988年   73766篇
  1987年   72330篇
  1986年   67782篇
  1985年   64524篇
  1984年   47956篇
  1983年   40590篇
  1982年   23097篇
  1981年   20796篇
  1979年   42516篇
  1978年   29415篇
  1977年   25054篇
  1976年   23299篇
  1975年   24997篇
  1974年   29870篇
  1973年   28517篇
  1972年   26520篇
  1971年   24215篇
  1970年   22702篇
  1969年   20966篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
61.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
62.
OBJECTIVE: To explore the presence and grade of denervation in three mimic muscles in facial nerve palsy. METHODS: The frontalis, orbicularis oculi (OO), and mentalis muscles were explored in 54 patients with Bell's palsy, after 30 days from the beginning of symptoms. Concentric needle electromyography, including fibrillation detection, was performed in the three muscles on the affected side. Compound muscle action potentials (CMAP) were recorded on both sides and a CMAP ratio was calculated from each muscle. The House-Brackman scale was used to assess the initial clinical evaluation and the follow-up until recovery. RESULTS: Fibrillation was recorded in 32 patients on the 30th day after the onset and was present in 100% of mentalis and in 90% of frontalis, but in only 34% of OO, a statistically significant difference. The grade of fibrillation in OO was also statistically lower from those in the other two muscles. The 32 patients were grouped according to the presence (A) or not (B) of fibrillation in OO. In group A, CMAP ratios (affected/normal side) did not differ significantly among the three muscles. However, in group B they were significantly greater in OO and frontalis than in mentalis. In between-group comparison, group B muscles had significantly higher CMAP ratios, lower degree of fibrillation, and better functional recovery. CONCLUSION: In facial palsy, the presence and grade of fibrillation in OO are lower than in frontalis and mentalis muscles and prognosis is more favorable for the non-fibrillating OO group of patients.  相似文献   
63.
OBJECTIVES: To evaluate a novel method for localization of subdural electrodes in presurgical assessment of patients with drug-resistant focal epilepsy. METHODS: We studied eight consecutive patients with posterior epilepsy in whom subdural electrodes were implanted for presurgical evaluation. Electrodes were detected on post-implantation brain CT scans through a semiautomated procedure based on a MATLAB routine. Then, post-implantation CT scans were fused with pre-implantation MRI to localize the electrodes in relation to the underlying cortical structures. The reliability of this procedure was tested by comparing 3D-rendered MR images of the electrodes with electrode position as determined by intraoperative digital photography. RESULTS: In each patient, all electrodes could be correctly localized and visualized in a stereotactic space, thus allowing optimal surgery planning. The agreement between the procedure-generated images and the digital photographs was good according to two independent raters. The mean mismatch between the 3D images and the photographs was 2 mm. CONCLUSIONS: While our findings need confirmation on larger samples including patients with anterior epilepsy, this procedure allowed to localize subdural electrodes and to establish the spatial relationship of each electrode to the underlying brain structure, either normal or damaged, on brain convessity, basal and medial cortex. SIGNIFICANCE: Being simple, rapid, unexpensive, and reliable, this procedure holds promise to be useful to optimize epilepsy surgery planning.  相似文献   
64.
65.
66.
67.
68.
69.
AIM: The innovations for disease management need to be thoroughly evaluated so that their benefits and potential downsides can be compared with the already existing approaches. Endovascular laser (EVL) treatment for varicose veins offers today several advantages over surgical standard stripping. The Italian Endovenous-laser Working Group (IEWG) is a homogeneous group of surgeons and phlebologists who have been using EVL since 1999 and has undertaken to examine EVL in a multicenter study starting from a well defined rationale, with the benefit of a single protocol to use. METHODS: In a cooperative, multicenter, clinical study, 1076 limbs in 1050 patients, mean age of 54.5 years, 241 males and 809 females affected by chronic venous insufficiency (CVI) were considered eligible for surgery and stratified by CEAP classification in a four-year period (January 1999 December 2003). Inclusion criteria were insufficiency of the great and/or small saphenous vein at various levels, beyond those accessory saphenous trunks with incompetence in the saphenofemoral junction. In all cases truncular reflux apparead up on duplex scan examination, with or without associated varicosities. All the patients underwent a surgery on the basis of the clinical assessment. All the centres involved performed treatment in conformity with the Food and Drug Administration (FDA) validated procedure, using an endo-laser venous system kit with a 810-980 nm diode. Duplex scan was performed in all patients after 36 months with very few lost to follow-up cases. RESULTS: In the immediate postoperative period the results have been impressive, with a very effective closure of incompetent great saphenous vein and the other treated varicose veins (the early occlusion rate has been 99%). Major complications have not been detected: in particular, no deep venous thrombosis (DVT) evaluated duplex ultrasound. The patients' acceptability and satisfaction regarding the procedure, have been measured by means of a questionnaire on the quality of life, and the result was 96.7%. After 36 months, the total occusion rate of saphenous trunks has been 97%. CONCLUSIONS: The first important Italian experience with EVL based on preoperative, perioperative and postoperative duplex control and which is also based on the patients' satisfaction at mid/long-term has indicated some advantages over the standard treatment with the stripping method. In terms of reduced postoperative pain, shorter sick leave, a faster resumption of the normal activities, and, in particular, the total absence of DVT, we can conclude that EVL is a good solution for all patients with anatomic and hemodinamic patterns for saphenous vein surgery.  相似文献   
70.
背景:浴光疗同步治疗银屑病的有效性与UVB和死海盐的多靶点作用有关,同步治疗能够起到协同功效。目的:本回顾性研究的目的:①评价浴光疗同步治疗各种临床类型银屑病的有效性;②观察治疗反应有无不同;③获得更多数据以预测对不同类型银屑病的治疗效果,以便针对患者的类型选择治疗效果良好的方法。方法:根据Regensburg计划,患者接受了一个包括35次治疗的基础同步浴光疗疗程,随后又接受了一个包括25次治疗的维持治疗疗程。治疗中每周进行PASI评分以评价患者的皮肤状态。对373例按计划完成基础疗程的患者和其中78例完成维持疗程的患者的治疗…  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