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   1456377篇
  免费   105987篇
  国内免费   4382篇
耳鼻咽喉   18750篇
儿科学   47824篇
妇产科学   39250篇
基础医学   215674篇
口腔科学   39934篇
临床医学   139885篇
内科学   279863篇
皮肤病学   29826篇
神经病学   124054篇
特种医学   53304篇
外国民族医学   366篇
外科学   202724篇
综合类   29322篇
现状与发展   1篇
一般理论   495篇
预防医学   121053篇
眼科学   31665篇
药学   107077篇
  6篇
中国医学   3351篇
肿瘤学   82322篇
  2021年   12009篇
  2019年   12866篇
  2018年   18932篇
  2017年   14544篇
  2016年   16199篇
  2015年   17707篇
  2014年   23606篇
  2013年   36967篇
  2012年   50535篇
  2011年   53903篇
  2010年   31083篇
  2009年   27664篇
  2008年   49864篇
  2007年   52618篇
  2006年   52436篇
  2005年   50767篇
  2004年   48347篇
  2003年   46239篇
  2002年   44966篇
  2001年   65007篇
  2000年   67754篇
  1999年   55291篇
  1998年   15851篇
  1997年   14315篇
  1996年   13923篇
  1995年   13144篇
  1994年   12292篇
  1993年   11529篇
  1992年   42258篇
  1991年   41328篇
  1990年   39996篇
  1989年   37894篇
  1988年   35080篇
  1987年   34222篇
  1986年   32594篇
  1985年   31260篇
  1984年   23623篇
  1983年   20086篇
  1982年   12262篇
  1981年   10763篇
  1979年   21249篇
  1978年   15205篇
  1977年   12477篇
  1976年   12251篇
  1975年   12470篇
  1974年   15156篇
  1973年   14786篇
  1972年   13608篇
  1971年   12701篇
  1970年   11746篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
There are no data available combining transbronchial needle aspiration (TBNA) of mediastinal lymph nodes and positron emission tomography (PET) in the staging of nonsmall cell lung cancer (NSCLC). The aim of the current study was to determine if these two methods can enhance the negative predictive value of the individual modality alone, for a specific lymph node station, and if this integrated approach can reduce the number of mediastinoscopies. A total of 113 patients with enlarged mediastinal lymph nodes (> or = 1 cm), who underwent both TBNA and PET scanning, were included. In 51 patients, histopathology, confirmed by surgical lymph node dissection, was compared with PET results and TBNA. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to detect malignant lymphadenopathy was 68 (13/19), 89 (119/134), 46 (13/28), 95 (119/125) and 86% (132/152) for PET, respectively; 54% (6/11), 100 (53/53), 100 (6/6), 91 (53/58) and 92% (59/64), respectively for TBNA; and 100 (11/11), 94 (50/53), 79 (11/14), 100 (50/50) and 95 (61/64) for combined TBNA and PET, respectively. Combination of transbronchial needle aspiration and positron emission tomography has the potential to allow adequate mediastinal staging of nonsmall cell lung cancer with enlarged lymph nodes in most patients without the need for mediastinoscopy.  相似文献   
62.
63.
64.
65.
66.
French asthma patients may be supervised by general practitioners (GPs) and/or specialists. Therefore, this study examined asthma management in patients exclusively supervised by specialists (SPE), GPs, (GP) and both (GP+SPE group), and compared the findings. Asthma patients were consecutively recruited in 348 pharmacies. Each patient completed a questionnaire providing data on personal characteristics, asthma management, perception of disease and asthma supervision. Asthma control was measured using the Asthma Control Test. Questionnaires were linked to computerised records of medications which had been dispensed before inclusion in the study. From the 1,256 patients (mean age = 36.1 yrs, 54.3% females), 11.4, 36.6, and 52.0% were placed in the SPE, GP, and GP+SPE groups, respectively. During the previous 4 weeks, most patients in the SPE group were properly controlled (52.2 versus 26.4 and 21.5% in GP and GP+SPE groups, respectively). The SPE group made more use of fixed combinations of long-acting beta agonist and inhaled corticosteroid, while receiving less short-acting beta agonists, antitussives and antibiotics. Striking differences in symptoms and asthma management were observed according to the type of asthma supervision. The current results strongly support the need to improve the management of asthma in primary care, and the coordination of care between general practitioners and specialists.  相似文献   
67.
68.
Research coordinators in intensive care are a growing specialty about which little is known. This cross-sectional study surveyed the Australia and New Zealand Intensive Care Research Coordinators' Group (n = 49) regarding demographics, education, employment history, job structure, and role content. Most research coordinators were highly qualified and experienced nurses who undertake pharmaceutical trials, multicenter projects, departmental medical and nursing research, audits and data registries, and their own projects.  相似文献   
69.
70.
OBJECTIVE: Surgical reduction and retention of apophyseal avulsion injuries at the medial epicondyle to prevent joint instability, lasting malalignment, or pseudarthrosis. INDICATIONS: Absolute: intraarticular apophyseal dislocation of the medial epicondyle, complete lesion of the ulnar nerve. Relative: dislocation of the apophysis (> 4 mm) in children > 5 years of age; the need for intervention increases in children as the degree of dislocation, age, and athletic activity increase. CONTRAINDICATIONS: Dislocation of the medial epicondyle (< or = 4 mm) in children < 5 years of age, provided the fragment location is not intraarticular. SURGICAL TECHNIQUE: Open reduction of the apophysis through a medial approach. Identification of the ulnar nerve. In young children or with small fragments fixation with Kirschner wire. Screw fixation in older children or for larger fragments. POSTOPERATIVE MANAGEMENT: Long upper-arm plaster cast until wound healing is achieved. Subsequently, upper-arm plaster cast for 3 weeks. Removal of Kirschner wires after 4-6 weeks, screw removal after 8-12 weeks. Physiotherapy only if marked reduction of elbow mobility is found 6 weeks after cast removal. RESULTS: From January 1, 1994 to December 31, 2003, 25 children with an average age of 12 years suffering from medial epicondylar avulsion fractures were operated on using open reduction and Kirschner wire fixation. An average of 3 years after the injury 14 of these children underwent follow-up examination using a procedure that took subjective, clinical and radiologic parameters into account. Two children showed a slight reduction in overall strength of the injured extremity when compared with the contralateral extremity. One child had a flexion deficit of 10 degrees, all other children showed movement limitations of < or = 5 degrees compared to the contralateral extremity. In all the cases available to follow-up, there was a slight increase in valgus alignment of the elbow joint compared with the uninjured side (3 degrees on average). All fractures consolidated within 6 weeks.  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