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   6338篇
  免费   586篇
  国内免费   62篇
耳鼻咽喉   66篇
儿科学   341篇
妇产科学   101篇
基础医学   766篇
口腔科学   132篇
临床医学   763篇
内科学   1497篇
皮肤病学   90篇
神经病学   560篇
特种医学   349篇
外科学   735篇
综合类   314篇
一般理论   4篇
预防医学   533篇
眼科学   77篇
药学   373篇
中国医学   5篇
肿瘤学   280篇
  2023年   41篇
  2021年   97篇
  2020年   75篇
  2019年   90篇
  2018年   98篇
  2017年   111篇
  2016年   102篇
  2015年   111篇
  2014年   183篇
  2013年   257篇
  2012年   317篇
  2011年   305篇
  2010年   213篇
  2009年   202篇
  2008年   265篇
  2007年   345篇
  2006年   265篇
  2005年   251篇
  2004年   254篇
  2003年   208篇
  2002年   210篇
  2001年   217篇
  2000年   215篇
  1999年   162篇
  1998年   117篇
  1997年   101篇
  1996年   100篇
  1995年   113篇
  1994年   106篇
  1993年   94篇
  1992年   115篇
  1991年   124篇
  1990年   109篇
  1989年   99篇
  1988年   115篇
  1987年   91篇
  1986年   110篇
  1985年   98篇
  1984年   67篇
  1983年   80篇
  1982年   63篇
  1981年   42篇
  1980年   36篇
  1979年   58篇
  1978年   55篇
  1977年   32篇
  1976年   38篇
  1975年   45篇
  1973年   32篇
  1968年   32篇
排序方式: 共有6986条查询结果,搜索用时 109 毫秒
1.
For patients who receive a liver transplant (LTX) for alcoholic liver disease (ALD), investigators are focusing beyond survival to determine specific alcohol use outcomes. Studies suggest the use of alcohol ranges from 8 to 22% for the first post-transplant year with cumulative rates reaching 30 to 40% by 5 years following transplantation. Yet while investigators are interested in determining specific rates of alcohol use and predictors of use, only three studies since 1990 have been prospective. In 1998, we began a prospective study of post-LTX alcohol consumption in ALD recipients using multiple repeated measures of alcohol use. After 5 years of follow-up, we found that 22% had used any alcohol by the first year and 42% had a drink by 5 years. By 5 years, 26% drank at a heavier use (binge) pattern and 20% drank in a frequent pattern. In a univariate model, predictors of alcohol use included pre-transplant length of sobriety, a diagnosis of alcohol dependence, a history of other substance use, and prior alcohol rehabilitation.  相似文献   
2.
3.
Haaga  JR; Beale  SM 《Radiology》1986,161(3):829-830
By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6).  相似文献   
4.
IL2-PE40 is a chimeric protein composed of human interleukin-2 (IL2) genetically fused to a modified form of Pseudomonas exotoxin lacking the cell recognition domain. IL2-PE40 is cytotoxic for IL2 receptor-bearing lymphocytes in culture and can inhibit activation of T cells in vivo. IL2-PE40 can significantly diminish antigen-stimulated proliferation of lymphocytes sensitized to myelin basic protein. Intraperitoneal administration of IL2-PE40 not only markedly inhibits the clinical manifestations of adoptively transferred relapsing experimental allergic encephalomyelitis but also dramatically reduces both inflammation and demyelination characteristic of the disease.  相似文献   
5.
BACKGROUND: Although nationally recognized learning objectives for undergraduate surgical education exist, the extent to which Canadian medical schools follow these guidelines has never been established. METHODS: We distributed a survey to all program directors and clinical-teaching-unit coordinators for undergraduate surgery at Canada's 16 medical schools, and subsequently assessed the perceived emphasis placed on learning objectives and student performance, and the impact of instructional tools and teaching locations. RESULTS: Program directors in 15 medical schools responded to the survey. We identified a wide variation in the emphasis placed on basic learning objectives as well as specialty specific learning objectives. The length of rotations, methods of instruction and tools used to grade student performance also varied widely. CONCLUSIONS: Our findings suggest significant variation in the design and implementation of undergraduate surgical education in Canada. This study may serve as a basis for reassessing learning objectives in Canadian undergraduate surgical education.  相似文献   
6.
7.
8.
We tested the hypothesis that since the implementation of the prospective payment system (PPS), elderly patients hospitalized for hip fractures receive shorter, less care-intensive hospitalizations and are more frequently institutionalized. In blinded fashion, we reviewed the charts of elderly patients with hip fractures admitted to a municipal hospital from 1981 through 1985. Demographic and clinical characteristics of patients treated before implementation of the PPS were similar to patients treated thereafter. After implementation of the PPS, the mean length of hospitalization fell from 16.6 to 10.3 days, and the mean number of physical therapy sessions received decreased from 9.7 to 4.9. Concomitantly, the proportion of patients discharged to a nursing home increased (21% to 48%), as did the proportion receiving nursing home care at six months after discharge (13% to 39%). This increase in long-term nursing home placement suggests that the quality of care for elderly patients with hip fractures may have deteriorated.  相似文献   
9.
The authors describe 12 patients in whom feeding tubes were inadvertently placed in the bronchial tree a total of 14 times. All but four of the misplacements were complicated by pneumothorax. No deaths were directly attributable to the misplacements, although one cardiac arrest occurred as a late complication of intrapleural feeding. Careful, controlled insertion of feeding tubes and radiographic confirmation of their placement are essential to reduce morbidity and mortality.  相似文献   
10.
Alcohol and tobacco use commonly co-occur, with at least 90% of those with an alcohol problem also using tobacco. Thus, 3 years ago when we discovered higher rate of late deaths due to lung and oropharyngeal cancer in patients who had received a transplant for alcoholic liver disease (ALD), we hypothesized that these patients were continuing to expose themselves to tobacco after liver transplantation (post-LTX) and that this behavior was increasing their risk for cancer. We subsequently began a prospective investigation of post-LTX tobacco use in patients having undergone LTX for ALD (n = 172). For 33 recipients we had data starting from our first assessment at 3 months post-LTX and for this subgroup we report on the details of the timing of tobacco use resumption and the redevelopment of nicotine addiction. We found that on average more than 40% are smoking across all time periods. ALD recipients resume smoking early post-LTX, increase their consumption over time, and quickly become tobacco dependent. These data highlight an underrecognized serious health risk for these patients and demonstrate our need for more stringent clinical monitoring and intervention for tobacco use in the pre- and post-LTX periods.  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