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   2439篇
  免费   127篇
  国内免费   21篇
耳鼻咽喉   29篇
儿科学   113篇
妇产科学   144篇
基础医学   315篇
口腔科学   27篇
临床医学   237篇
内科学   389篇
皮肤病学   12篇
神经病学   330篇
特种医学   230篇
外科学   284篇
综合类   40篇
一般理论   3篇
预防医学   54篇
眼科学   101篇
药学   164篇
中国医学   1篇
肿瘤学   114篇
  2021年   25篇
  2020年   22篇
  2019年   33篇
  2018年   39篇
  2017年   30篇
  2016年   43篇
  2015年   46篇
  2014年   54篇
  2013年   75篇
  2012年   101篇
  2011年   101篇
  2010年   68篇
  2009年   61篇
  2008年   92篇
  2007年   101篇
  2006年   95篇
  2005年   111篇
  2004年   97篇
  2003年   103篇
  2002年   63篇
  2001年   64篇
  2000年   89篇
  1999年   90篇
  1998年   53篇
  1997年   65篇
  1996年   54篇
  1995年   50篇
  1994年   38篇
  1993年   42篇
  1992年   50篇
  1991年   54篇
  1990年   49篇
  1989年   37篇
  1988年   59篇
  1987年   53篇
  1986年   30篇
  1985年   38篇
  1984年   26篇
  1983年   17篇
  1982年   27篇
  1981年   17篇
  1980年   25篇
  1979年   12篇
  1978年   17篇
  1977年   27篇
  1976年   17篇
  1975年   12篇
  1973年   11篇
  1970年   15篇
  1969年   13篇
排序方式: 共有2587条查询结果,搜索用时 453 毫秒
1.
In a study of the families of 21 schizotypal patients, we found an increased morbidity risk for schizophrenia compared with that in the families of 21 nonschizotypal patients and 42 controls. The Axis I diagnoses did not influence the distribution of the morbidity risk in the families of the schizotypal patients. If the schizotypal subjects also had other personality disorders, the morbidity risk for schizophrenia among their relatives was lower, although not significantly.  相似文献   
2.
Abstract Calcaneal fracture is the most common of the tarsal fractures and represents 1%–2% of all fractures. The fractures may be divided into extra-articular (not affecting the joint) and intra-articular (involving the talo-calcaneal and calcaneal cuboid joints) types. The management of heel fractures includes nonoperative and operative treatments, but no clear consensus has been reached. The choice of operative treatment is still controversial with many factors influencing the final clinical outcome. Many studies have assessed the outcome of treatment of calcaneal fractures, but there is a general disagreement on their management. The objective of this study was to collect and evaluate the scientific evidence reported in the literature supporting the different treatments for calcaneal fractures.  相似文献   
3.
4.
5.
Objectives: To illustrate endoscopic techniques used in the treatment of esthesioneuroblastoma and to advocate this method of management followed by radiation therapy in selected cases. Methods: A retrospective case series of 10 patients with esthesioneuroblastomas treated between 1999 and 2004 at a tertiary referral center using endonasal techniques. Results: Mean age of patients at presentation was 56.2 years (median 57 years). Seven patients were female and 3 patients were male. Kadish staging at presentation was: A - 3 patients, B - 5 patients, C - 2 patients. Dulguerov stage at presentation was: T1 - 4 patients, T2 - 4 patients, T3 - 2 patients. The period of follow-up ranged from 11 months to 74 months (mean 38.1 months, median 39 months). To date no recurrence has developed in any patient. Conclusions: Our experience suggests that endoscopic surgery can be an effective method of management. Strict attention to selection criteria, careful surgical techniques, and regular follow-up are key elements for success.  相似文献   
6.
7.
Bottomley  PA; Lee  Y; Weiss  RG 《Radiology》1997,204(2):403
  相似文献   
8.
Investigations were carried out on the radiation-induced graft copolymerization by direct irradiation of dimethylaminoethyl methacrylate on to poly(bis(trifluoroethoxy)phosphazene) and on to poly (bis(phenoxy)phosphazene). Kinetics of grafting were followed with the polyphosphazenes immersed in monomer - methanol mixtures of various composition. The grafted film samples were quaternized with methyl iodide and, to the produced ammonium group, heparin was ionically bonded with high yield. On the grafted and heparinized-grafted film samples an evaluation of hydrophilicity, mechanical properties, biocompatibility and anticoagulating properties was carried out.  相似文献   
9.
10.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).  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