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   6450篇
  免费   1038篇
  国内免费   36篇
耳鼻咽喉   53篇
儿科学   284篇
妇产科学   142篇
基础医学   951篇
口腔科学   159篇
临床医学   951篇
内科学   1091篇
皮肤病学   74篇
神经病学   757篇
特种医学   352篇
外国民族医学   1篇
外科学   685篇
综合类   469篇
一般理论   3篇
预防医学   505篇
眼科学   127篇
药学   615篇
中国医学   3篇
肿瘤学   302篇
  2021年   79篇
  2019年   83篇
  2018年   117篇
  2017年   82篇
  2016年   76篇
  2015年   111篇
  2014年   143篇
  2013年   199篇
  2012年   270篇
  2011年   281篇
  2010年   170篇
  2009年   150篇
  2008年   226篇
  2007年   251篇
  2006年   261篇
  2005年   303篇
  2004年   253篇
  2003年   239篇
  2002年   248篇
  2001年   214篇
  2000年   220篇
  1999年   210篇
  1998年   123篇
  1997年   94篇
  1996年   112篇
  1995年   96篇
  1994年   92篇
  1993年   87篇
  1992年   158篇
  1991年   174篇
  1990年   132篇
  1989年   165篇
  1988年   159篇
  1987年   190篇
  1986年   146篇
  1985年   157篇
  1984年   120篇
  1983年   105篇
  1982年   86篇
  1981年   94篇
  1980年   106篇
  1979年   106篇
  1978年   70篇
  1977年   72篇
  1976年   63篇
  1975年   56篇
  1974年   67篇
  1972年   66篇
  1971年   47篇
  1970年   48篇
排序方式: 共有7524条查询结果,搜索用时 15 毫秒
31.
32.
33.
Carcinoma of the hepaticopancreatic ampullar region: role of US   总被引:3,自引:0,他引:3  
Hepaticopancreatic ampullar tumors are so called because they are located at the confluence of the bile duct, pancreatic duct, and duodenum. Jaundice is an early sign of the disease and often leads to early diagnosis and favorable prognosis compared with other tumors that occur in this area. Of eight patients who underwent ultrasound (US) in the past 5 years, six (75%) were found to have tumor. The sizes of the tumors ranged from 1.6 to 2 cm. An intraluminal, polypoid mass in the distal part of the common bile duct was seen in four patients. In the other two patients, a sharply delineated mass gave rise to abrupt termination of the distal duct. Improved US resolution, more experience with this modality, and accurate diagnosis of these tumors with US will contribute to improved detection and prompt treatment.  相似文献   
34.
This study reviewed a series of patients with Crohn's disease managed by surgeons of the Department of Colon and Rectal Surgery, St Vincent's Hospital, Melbourne, since 1978. There were 306 patients: 171 males and 135 females. The mean age at diagnosis was 33.4 years (range 11–93). The distribution of the disease was small bowel 32.3%, small bowel and colon 26.5%, colon 39.9%, and anal disease alone 1.6%. A total of 416 abdominal operations were performed on 204 patients. The commonest indications for surgery were failed medical therapy (21.9%), small bowel obstruction (15.9%), enteric tistula (10.1%), and intra-abdominal abscess (10.1%). The most frequently performed procedures were ileocolic resection with anastomosis (28.8%), small bowel resection (9.4%), and total colectomy and ileostomy (7.0%). Postoperative complications included anastomotic leaks in 4.0%. intra-abdominal abscess formation in 3.6%, and enterocutaneous fistulae developed in 6%. Three patients died during the review period. During follow up (mean 84.4). 30% of patients developed recurrence requiring further surgery at a mean of 72.7 months postoperatively. The most frequent site for a recurrence was the pre-anastomotic terminal ileum (61.7%). In conclusion. the majority of patients with Crohn's disease will require resectional surgery at some stage. This can be performed with a low mortality and morbidity, and a recurrence rate of around 5% per year.  相似文献   
35.
We have obtained multislice magnetic resonance (MR) images of the eye and calculated ocular dimensions along the three cardinal axes: antero-posterior (A-P), equatorial, and vertical. We found no difference in the shape of hyperopic (average refractive error: +3.72 D) and emmetropic eyes, both of which had an equatorial diameter longer than the A-P and vertical diameters. Myopic eyes (average refractive error: -6.54 D) were larger than hyperopic eyes, and most had the same spheroelliptical shape as that of the emmetropic and hyperopic eyes. The results suggest that during myopic progression an overall enlargement or a radial volume expansion has occurred.  相似文献   
36.
Recurrent bilateral renal agenesis in siblings is very rare. Presented is a case diagnosed with sonographically aided amnioinfusion at 18 weeks in a woman with an infant affected with the same condition in a previous pregnancy.  相似文献   
37.
38.
39.
Conventional follicle harvesting techniques for hair transplantation are limited by the available scalp donor hair. The development of an innovative technique of microsurgical single follicular unit extraction has made it possible to exploit body hair grafts for scalp transplantation. This case study reports on 18 months of follow-up on a patient with extensive scalp scarring who underwent a transplantation procedure using donor chest hair. The photographically documented results show a change in the length of the chest hair measuring an average of 4 cm at transplant to 15 cm by 18 months post-transplant. The transplanted chest grafts provided an excellent cosmetic result for hair replacement.  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