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   4100篇
  免费   229篇
  国内免费   6篇
耳鼻咽喉   12篇
儿科学   179篇
妇产科学   55篇
基础医学   372篇
口腔科学   169篇
临床医学   433篇
内科学   671篇
皮肤病学   233篇
神经病学   269篇
特种医学   353篇
外科学   502篇
综合类   84篇
一般理论   2篇
预防医学   364篇
眼科学   269篇
药学   106篇
  1篇
中国医学   8篇
肿瘤学   253篇
  2019年   28篇
  2018年   28篇
  2017年   29篇
  2016年   42篇
  2015年   36篇
  2014年   58篇
  2013年   86篇
  2012年   119篇
  2011年   139篇
  2010年   84篇
  2009年   76篇
  2008年   158篇
  2007年   157篇
  2006年   161篇
  2005年   151篇
  2004年   152篇
  2003年   122篇
  2002年   104篇
  2001年   95篇
  2000年   108篇
  1999年   96篇
  1998年   82篇
  1997年   63篇
  1996年   67篇
  1995年   75篇
  1994年   61篇
  1993年   68篇
  1992年   84篇
  1991年   97篇
  1990年   111篇
  1989年   136篇
  1988年   131篇
  1987年   133篇
  1986年   127篇
  1985年   99篇
  1984年   84篇
  1983年   60篇
  1982年   45篇
  1981年   55篇
  1980年   47篇
  1979年   59篇
  1978年   72篇
  1977年   53篇
  1976年   47篇
  1975年   39篇
  1974年   29篇
  1973年   40篇
  1972年   35篇
  1970年   36篇
  1969年   30篇
排序方式: 共有4335条查询结果,搜索用时 0 毫秒
11.
In 1998, the New York City Department of Health and the Mayor’s Office of Emergency Management began monitoring the volume of ambulance dispatch calls as a surveillance tool for biologic terrorism. We adapted statistical techniques designed to measure excess influenza mortality and applied them to outbreak detection using ambulance dispatch data. Since 1999, we have been performing serial daily regressions to determine the alarm threshold for the current day. In this article, we evaluate this approach by simulating a series of 2,200 daily regressions. In the influenza detection implementation of this model, there were 71 (3.2%) alarms at the 99% level. Of these alarms, 64 (90%) occurred shortly before or during a period of peak influenza in each of six influenza seasons. In the bioterrorism detection implementation of this methodology, after accounting for current influenza activity, there were 24 (1.1%) alarms at the 99% level. Two occurred during a large snowstorm, 1 is unexplained, and 21 occurred shortly before or during a period of peak influenza activity in each of six influenza seasons. Our findings suggest that this surveillance system is sensitive to communitywide respiratory outbreaks with relatively few false alarms. More work needs to be done to evaluate the sensitivity of this approach for detecting nonrespiratory illness and more localized outbreaks.  相似文献   
12.
13.
This article briefly reviews the tactical integrationist's perspective in the work with multiple personality disorder patients. Its foundation is a cognitively based treatment paradigm geared toward controlled abreactions with cognitive restructuring throughout therapy. It is a suppression-dilution-of-affect model that focuses on the achievement of control and mastery for patient and therapist alike.  相似文献   
14.
15.
This report of the North American Pediatric Transplant Cooperative Study summarizes data contributed by 57 participating centers on 754 children with 761 transplants from 1 January 1989 to 16 February 1989. Data collection was initiated in October 1987 and follow-up of all patients is ongoing. Transplant frequency increased with age; 24% of the patients were less than 5 years, with 7% being under 2 years. Common frequent diagnoses were: aplastic/dysplastic kidneys (18%), obstructive uropathy (16%), and focal segmental glomerulosclerosis (12%). Preemptive transplant, i.e., transplantation without prior maintenance dialysis, was performed in 21% of the patients. Dialytic modalities pretransplant were peritoneal dialysis in 42% and hemodialysis in 25%. Bilateral nephrectomy was reported in 29%. Live-donor sources accounted for 42% of the transplants. Among cadaveric donors, 41% of the donors were under 11 years old. During the first post-transplant month, maintenance therapy was used similarly for live-donor and cadaver source transplants, with prednisone, cyclosporine, and azathioprine used in 93%, 83%, and 81%, respectively. Triple therapy with prednisone, cyclosporine, and azathioprine was used in 78%, 75%, and 75% of functioning cadaver source transplants at 6 months, 12 months, and 18 months as opposed to 60%, 63%, and 54% for live-donor procedures, with single-drug therapy being uncommon. Rehospitalization during months 1–5 occurred in 62% of the patients, with treatment of rejection and infection being the main causes. Additionally, 9% were hospitalized for hypertension. During months 6–12 and 12–17, 30% and 28% of the patients with functioning grafts were rehospitalized. Times to first rejection differed significantly for cadaver and live-donor transplants. The median time to the first rejection was 36 days for cadaver transplants and 156 days for live-donor transplants. Overall, 57% of treated rejections were completely reversible although the complete reversal rate decreased to 37% for four or more rejections. One hundred and fifty-two graft failures had occurred at the time of writing, with a 1-year graft survival estimate of 0.88 for live-donor and 0.71 for cadaver source transplants. In addition to donor source, recipient age is a significant prognostic factor for graft survival. Among cadaver donors, decreasing donor age is associated with a decreasing probability of graft survival. Thirty-five deaths have occurred; 16 attributed to infection and 19 to other causes. The current 1-year survival estimate is 0.94. There have been 9 malignancies.A list of all participating centers and the names of the investigators is printed on pages 552–553  相似文献   
16.
17.
Respiratory health variables were studied cross-sectionally in 227 employees of a plastics molding facility where numerous complaints had been apparently associated with the use of azodicarbonamide foaming agent in injection molding. Pre- and postshift respiratory status measures and azodicarbonamide concentrations were also obtained for 17 employees. Cross-sectional pulmonary function differences by injection molding status were not observed. Modest decrements in pulmonary function measures were observed between start and end of shift but with no dose-effect relationship. A strong association was observed for injection molding workers for eye/nose/throat irritation, cough, and wheezing. Additionally, wheezing, chest tightness, and symptoms of chronic bronchitis were strongly associated with work in injection molding during periods in which azodicarbonamide was in use. These results suggest respiratory symptom causation by some combination of azodicarbonamide itself, reaction products of azodicarbonamide formed during injection molding, or other unidentified agents uniquely associated with the process of injection molding with azodicarbonamide foaming agent.  相似文献   
18.
19.
The management of self-destructive behavior in eating disorder patients with borderline personality is a genuine therapeutic challenge. We present an integrated psychotherapy appproach that we utilize in the context of an extended therapeutic milieu. This treatment model enables coordinated intervention to occur in three different arenas: individual psychotherapy, group psychotherapy, and consultation intervention. The paper closes with a discussion of the limitations of this approach.  相似文献   
20.
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