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   713476篇
  免费   49225篇
  国内免费   1337篇
耳鼻咽喉   9285篇
儿科学   23416篇
妇产科学   17675篇
基础医学   111234篇
口腔科学   20125篇
临床医学   64231篇
内科学   136384篇
皮肤病学   16246篇
神经病学   50198篇
特种医学   25915篇
外国民族医学   76篇
外科学   106009篇
综合类   14845篇
现状与发展   2篇
一般理论   160篇
预防医学   51652篇
眼科学   16403篇
药学   54377篇
  3篇
中国医学   2373篇
肿瘤学   43429篇
  2021年   5565篇
  2018年   7996篇
  2017年   6210篇
  2016年   6944篇
  2015年   7681篇
  2014年   10455篇
  2013年   15590篇
  2012年   20823篇
  2011年   21864篇
  2010年   12929篇
  2009年   12100篇
  2008年   20310篇
  2007年   21887篇
  2006年   22239篇
  2005年   20819篇
  2004年   20324篇
  2003年   19272篇
  2002年   18808篇
  2001年   36583篇
  2000年   37193篇
  1999年   30608篇
  1998年   7957篇
  1997年   6732篇
  1996年   7044篇
  1995年   6676篇
  1994年   6145篇
  1993年   5633篇
  1992年   23114篇
  1991年   23083篇
  1990年   22439篇
  1989年   22257篇
  1988年   20174篇
  1987年   19556篇
  1986年   18584篇
  1985年   17410篇
  1984年   12767篇
  1983年   10814篇
  1982年   5951篇
  1979年   11592篇
  1978年   8175篇
  1977年   6870篇
  1976年   6614篇
  1975年   7310篇
  1974年   8543篇
  1973年   8189篇
  1972年   7718篇
  1971年   7171篇
  1970年   6918篇
  1969年   6351篇
  1968年   5829篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
161.
162.
In order to assess the histological tissue changes over time around the site of implant, tissue biopsies were taken at 1 to 38 months post-implant from 54 (34 male) consenting human subjects who had received the Australian subcutaneous naltrexone-poly(DL-lactide) implant for heroin dependence. The implant consists of multiple tablets containing compressed naltrexone-poly[trans-3,6-dimethyl-1,4-dioxane-2,5-dione] (DL-lactide) loaded microspheres. Assessment of tissue samples by pathologists showed an early phase (up to 12 months post-implant) of inflammation, foreign body reaction, and fibrosis. This subsided gradually over the next 12 months until tissue returned to normal by 25+ months. Sufficient evidence was not available to conclude that the poly(DL-lactide) implant matrix was totally biodegradable within the study period. While implant material was not identified in most of the latter biopsies, its presence was noted in one biopsy at 26 months post-implant. Nevertheless the study results did demonstrate the implant's biocompatibility by the lack of inflammation, foreign body reaction, and fibrosis detected by 25+ months. It seems highly probable that surgical technique rather than the implant itself was associated with the additional finding of fat necrosis. Moderate fat necrosis was observed as a common feature of biopsies carried out during the first 6 months following implant. It subsided to mild levels over the next 18 months, and was notably absent by 25+ months. The results of the study indicated that the Australian naltrexone-poly(DL-lactide) implant is well tolerated and may have a role for use in the management of medical conditions such as heroin dependence.  相似文献   
163.
Eight women had 10 toes treated for hallux rigidus by dorsal wedge osteotomy of the proximal phalanx and were reviewed after an average follow-up of 22 years. Five toes were symptom-free, four others did not restrict walking, and only one had required metatarsophalangeal fusion. We conclude that dorsal wedge osteotomy affords long-lasting benefits for hallux rigidus in the adolescent female.  相似文献   
164.
Despite being of fundamental importance, the late results of major arterial reconstruction rarely have been documented throughout a large metropolitan area. In this study of 932 patients entered into the computer registry of the Cleveland Vascular Society, 19 surgeons representing 13 community hospitals and referral centers in Cleveland and Akron report the intermediate-term outcome during a mean interval of 35 months after infrainguinal lower extremity revascularization performed in northeastern Ohio from 1978 through 1982. Operative risk (5%), the early amputation rate (7%), and actuarial 5-year survival (48% to 55%) for patients with rest pain or tissue necrosis were significantly worse (p less than 0.05) than comparable figures (0.6%, 0%, and 77%, respectively) for others who underwent procedures for disabling claudication. Although both materials had similar success above the knee, the cumulative 3-year patency rate of autogenous vein bypass to the distal popliteal (69% to 88%; p less than 0.05) and tibioperoneal arteries (43%; 0.05 less than p less than 0.1) was superior to the results of polytetrafluoroethylene grafts (32% to 50% and 19%, respectively). Moreover, polytetrafluoroethylene grafts required reoperations at three times the rate of vein grafts to maintain limb salvage.  相似文献   
165.
166.
Failure of genetically selected miniature swine to model NIDDM   总被引:2,自引:0,他引:2  
Ten young adult miniature swine from a line reported to be genetically selected for glucose intolerance and eight normal controls were obtained from Colorado State University. They were consecutively exposed to 4 mo of a high-fiber, low-fat standard swine diet; 4 mo of a high-sucrose, high-fat, low-fiber diabetogenic diet; and 4 mo of excess diabetogenic diet for obesification. Results of oral glucose tolerance and intravenous insulin tolerance tests conducted at the end of each regimen were compared. Hyperglycemia was not observed in any animals after any manipulation. Insulin sensitivity was also not influenced by diet. We conclude that F7 low-K miniature swine from this colony fail to model human non-insulin-dependent diabetes.  相似文献   
167.
168.
169.
A 68 year-old woman presented with a two-week history of amaurosis fugax, ipsilateral fronto-temporal headache and jaw claudication suggesting carotid giant cell arteritis. However, this syndrome proved to be due to atherosclerosis causing complete occlusion of the external carotid artery at its origin and narrowing of the internal carotid artery. Combined external and internal carotid endarterectomy relieved the symptoms. The symptom complex of temporal arteritis may be rarely mimicked by carotid atherosclerotic occlusive disease.  相似文献   
170.
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