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   26738篇
  免费   1342篇
  国内免费   90篇
耳鼻咽喉   384篇
儿科学   1509篇
妇产科学   616篇
基础医学   2917篇
口腔科学   597篇
临床医学   1524篇
内科学   5719篇
皮肤病学   797篇
神经病学   1595篇
特种医学   907篇
外科学   3579篇
综合类   794篇
一般理论   16篇
预防医学   1282篇
眼科学   1489篇
药学   2410篇
中国医学   184篇
肿瘤学   1851篇
  2023年   194篇
  2022年   458篇
  2021年   954篇
  2020年   502篇
  2019年   626篇
  2018年   801篇
  2017年   559篇
  2016年   706篇
  2015年   653篇
  2014年   1026篇
  2013年   1252篇
  2012年   1783篇
  2011年   1906篇
  2010年   1012篇
  2009年   834篇
  2008年   1301篇
  2007年   1341篇
  2006年   1322篇
  2005年   1148篇
  2004年   1042篇
  2003年   894篇
  2002年   800篇
  2001年   709篇
  2000年   705篇
  1999年   568篇
  1998年   235篇
  1997年   169篇
  1996年   145篇
  1995年   151篇
  1994年   116篇
  1993年   105篇
  1992年   368篇
  1991年   371篇
  1990年   339篇
  1989年   328篇
  1988年   288篇
  1987年   251篇
  1986年   234篇
  1985年   232篇
  1984年   171篇
  1983年   135篇
  1981年   91篇
  1979年   157篇
  1978年   97篇
  1977年   81篇
  1975年   84篇
  1974年   100篇
  1973年   92篇
  1972年   118篇
  1970年   78篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
A total of 675 strains of Salmonella bareilly received from different parts of India and France during 1959-92 were phage typed using six bacteriophages. Overall typability achieved was 90.8% with 23 distinct phage types excluding a group of untypable strains. Phage types have been defined in octal code. Simpson''s coefficient was applied for diversity index having a value of 0.839. This system was found to be reproducible, stable and epidemiologically useful.  相似文献   
73.
A study conducted in 1990 revealed that 2% (range 0.6-4.8) of negative blood smears were mislabelled as positive, and 6.7% of positive blood smears were mislabelled as negative. A result of such mislabelling would be inadequate treatment of a large number of patients. Hence the need to look into the training aspect and system of supervision of laboratory technicians. The present system of cross-checking of blood smears at different levels also needs to be reviewed. A study which could address itself to these needs is indicated.  相似文献   
74.
75.
Dihydrostreptomycin analogues with structural variations in their guanidino groups were prepared. The analogue with a methyl group on the guanidine at C-1 was nearly as active as dihydrostreptomycin against bacteria. However, the 2-imidazolin-2-ylamino substituent at C-1 eliminated activity. No analogue with a substituent on the C-3 guanidino group was active.  相似文献   
76.
This study was undertaken to record the Brainstem Evoked Responses in a group of 20 diabetic patients with normal hearing and were compared with responses of another group of 20 normal individuals. Eighth nerve transmission till the level of cochlear nucleus was found to be normal in diabetics. The delay in latency of Wave III, IV and V and interpeak latencies (I–III, I–V) were noted to be statistically significant, thus suggesting the presence of central neuropathy in patients with diabetes. No significant sex difference on latency of waves was observed.  相似文献   
77.
A case of veruccous carcinoma of the maxilla extending to alveulus and palate is reported. Treated with radical maxillectomy: there has been no recurrence within one year. The coexistance of submicous fibrosis and veruccous carcinoma is observed and the histological features of the later are highlighted.  相似文献   
78.
A bstract Objectives and Background : The purpose of this study was to document our initial experience with patients 90 years of age and older and to determine whether cardiac surgery is justified in this age group. Cardiac surgery in octogenarians has proven to be a successful and worthwhile procedure. A small group of nonagenarians with severe coronary artery disease (CAD) and aortic valve disease refractory to medical therapy have been considered for surgery. Methods : Fourteen patients aged 90 or more underwent cardiac surgery for symptomatic CAD or aortic valvular disease refractory to medical therapy. Eight patients underwent isolated coronary artery bypass grafting (CABG) and six patients underwent aortic valve replacement (AVR). All patients were in NYHA Class IV preoperatively. Results : Hospital mortality occurred in one patient (7%). Hospital morbidity occurred in 10 patients (71%) and included 7 cardiac, 5 neurological, 1 gastrointestinal, 1 infectious, and 1 pulmonary event. All survivors left the hospital symptomatically improved. The mean length of stay was 26 days. Four CABG patients went on to die at a mean of 2 years and 2 months, and 3 remain alive at a mean of 2 years and 4 months. Three AVR patients expired at a mean of 3 years and 4 months, and 3 remain alive at 4 years and 1 month. Conclusions : Cardiac surgery in carefully selected nonagenarians is justified and can be performed with acceptable results.  相似文献   
79.
OBJECTIVE: Surgical-site infection (SSI) is a serious and costly complication following coronary artery bypass graft (CABG). We analyzed surgical factors, microbiology, and complications at a 608-bed community teaching hospital to identify opportunities for prevention. METHODS: All patients undergoing CABG procedures from June 1997 through December 2000 were analyzed. Hospital records and postdischarge surveillance data were reviewed for demographics, surgical information, timing and classification of infection, microbiology, and bacteremic events. RESULTS: Of 3,443 patients undergoing CABG, sternal SSI developed in 122 (3.5%); 71 (58.2%) were classified as superficial SSI and 51 (41.8%) as deep SSI. Surgical antimicrobial prophylaxis was employed in all cases. On average, infection occurred 21.5 days (range, 4 to 315) after CABG. Most cases were diagnosed on readmission (59%); 20 cases (16%) were identified by postdischarge surveillance. Microbiological data were positive in 109 (89.3%), with a single pathogen implicated in most (86.2%). Gram-positive cocci were most frequently recovered (81%); gram-negative bacilli (17%), gram-positive bacilli (1%), and yeast (1%) were less common. Staphylococcus aureus was the most frequently isolated pathogen (49%). Bacteremia was noted in 22 instances (18%). It was significantly associated with deep SSI (P =. 002) and identified only in S. aureus cases. CONCLUSIONS: SSI complicated 3.5% of the procedures. S. aureus was implicated in most of the cases and was significantly associated with deep SSI. It was the only pathogen associated with secondary bacteremia. In addition to standard guidelines, targeted methods against S. aureus should help reduce the overall rate of SSI.  相似文献   
80.
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