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   2587736篇
  免费   185075篇
  国内免费   7571篇
耳鼻咽喉   34288篇
儿科学   85204篇
妇产科学   71574篇
基础医学   363600篇
口腔科学   69720篇
临床医学   234523篇
内科学   515659篇
皮肤病学   62470篇
神经病学   213479篇
特种医学   99886篇
外国民族医学   737篇
外科学   386452篇
综合类   50391篇
现状与发展   5篇
一般理论   968篇
预防医学   196182篇
眼科学   56664篇
药学   188018篇
  8篇
中国医学   5331篇
肿瘤学   145223篇
  2021年   19991篇
  2019年   20636篇
  2018年   29302篇
  2017年   22603篇
  2016年   26229篇
  2015年   29516篇
  2014年   40452篇
  2013年   60441篇
  2012年   80238篇
  2011年   84506篇
  2010年   51016篇
  2009年   49154篇
  2008年   79038篇
  2007年   83849篇
  2006年   85584篇
  2005年   81747篇
  2004年   78742篇
  2003年   76065篇
  2002年   73347篇
  2001年   128413篇
  2000年   131334篇
  1999年   110504篇
  1998年   31258篇
  1997年   27919篇
  1996年   28219篇
  1995年   27389篇
  1994年   25067篇
  1993年   23421篇
  1992年   85166篇
  1991年   81574篇
  1990年   78789篇
  1989年   76065篇
  1988年   69476篇
  1987年   67999篇
  1986年   63548篇
  1985年   60513篇
  1984年   44942篇
  1983年   37945篇
  1982年   22459篇
  1981年   19988篇
  1979年   38963篇
  1978年   27441篇
  1977年   23255篇
  1976年   21495篇
  1975年   22815篇
  1974年   26787篇
  1973年   25371篇
  1972年   23751篇
  1971年   21956篇
  1970年   20185篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Conditions that affect the dentition and the materials utilized to treat these conditions are often unfamiliar to the physician. Dental caries and missing teeth are processes routinely treated in dental practice. Recent improvements in dental materials and techniques permit the dentist to restore the dentition to allow for corrected form, function, esthetics, and patient comfort. This paper describes some of the common conditions that affect the dentition, and the modalities routinely used to treat them.  相似文献   
992.
993.
The ravelled sleeve of care. Managing the stresses of residency training   总被引:4,自引:0,他引:4  
J M Colford  S J McPhee 《JAMA》1989,261(6):889-893
  相似文献   
994.
A prospective randomized study was carried out on a total of 686 patients who underwent vaginal or abdominal hysterectomy. Of these, 338 were given prophylactic cefotetan (2 g) and 348 piperacillin (2 g). Both drugs were administered as i.v. bolus 30 min before operation. Findings confirm the higher risk of infection with abdominal hysterectomy and the advantages of the long half-life cephalosporin, cefotetan.  相似文献   
995.
Uveal melanoma radiation. 125I brachytherapy versus helium ion irradiation   总被引:4,自引:0,他引:4  
The optimum radiation therapy for uveal melanoma is uncertain. Both helium ion irradiation and 125I brachytherapy have been used to treat this neoplasm. This investigation analyzed the control and complication rates of uveal melanomas treated with helium ions of 125I plaques. In both a retrospective and a prospective dynamically balanced study, the control rates appeared to be similar. There were more posterior segment complications after 125I plaques and more anterior segment complications, including neovascular glaucoma, after helium ion irradiation. The follow-up period is too short to draw definitive conclusions on the radiation complications. Overall, approximately 89% of eyes were retained and less than 4% of treated eyes were removed because of failure to control the tumor.  相似文献   
996.
alpha 1-Antiproteinase is the major inhibitor of proteolytic enzymes, such as elastase, in human plasma. Its elastase-inhibitory capacity can be inactivated by exposure to hydroxyl radicals (.OH) generated either by pulse radiolysis or by an Fe3+-EDTA/H2O2/ascorbic acid system. Inactivation of alpha 1-antiproteinase by radiolytically-generated .OH under anoxic conditions was decreased by adding a range of anti-inflammatory drugs to the reaction mixtures, including the thiol compound penicillamine. However, under conditions favouring formation of oxysulphur radicals, protection by thiols such as penicillamine was much decreased. It is proposed that sulphur-containing radicals resulting from attack of biologically-produced oxidants upon penicillamine in the presence of O2 can themselves inactivate alpha 1-antiproteinase, and that such radicals might contribute to the side-effects produced by penicillamine or gold thiol therapy in rheumatoid arthritis.  相似文献   
997.
St. Jude Medical valve replacement was performed in 1,039 patients; 320 had aortic (AVR), 543 mitral (MVR), and 176 had double valve replacement (DVR). There were 44(4.2%) early deaths. Follow-up extended in 995 patients from 10 to 130 months, with a cumulative period of 2,730 patients-years. The overall survival rates of AVR, MVR, and DVR patients at 10 years were 60.5%, 89.6%, 90.3% respectively. The linearized incidences of valve thrombosis, thromboembolism, anticoagulation-related hemorrhage, prosthetic valve endocarditis, and significant hemolysis were as follows: 0.11%/pt-yr, 1.33%/pt-yr, 0.04%/pt-yr, 0.18%/pt-yr, and 0.11%/pt-yr, respectively. There were no structural failure after 10 years follow-up. Reoperation (explant and re-replacement or suture repair) was required in 10 patients. Seven of them had periprosthetic leakage, 2 had valve thrombosis, and one underwent reoperation because of a technical error. Actuarially over 98% of patients were free of valve-related mortality at 10 years. St. Jude Medical valve is an excellent alternative for use in the surgical treatment of valvular heart disease.  相似文献   
998.
999.
Skin Granulomas due to Mycobacterium gordonae   总被引:2,自引:0,他引:2  
A 38-year-old woman presented with small, ulcerated, red or bluish nodules on the right hand, clinically resembling mycobacterial granulomas; these appeared a few months after a bite by a rat, while the patient was collecting frogs in a pond in the Belgian Ardennes. The histopathologic picture was compatible with a diagnosis of mycobacterial infection and rare acid-fast bacilli could be found. Repeated bacteriologic investigations were performed and these led to the identification of a strain displaying characteristics of Mycobacterium gordonae. The skin condition responded well to rifampicin (300 mg/day) within 6 months.  相似文献   
1000.
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