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   9731篇
  免费   694篇
  国内免费   24篇
耳鼻咽喉   91篇
儿科学   309篇
妇产科学   220篇
基础医学   1592篇
口腔科学   115篇
临床医学   841篇
内科学   1948篇
皮肤病学   220篇
神经病学   886篇
特种医学   301篇
外国民族医学   2篇
外科学   1574篇
综合类   111篇
一般理论   3篇
预防医学   889篇
眼科学   138篇
药学   539篇
中国医学   43篇
肿瘤学   627篇
  2023年   43篇
  2022年   36篇
  2021年   182篇
  2020年   113篇
  2019年   164篇
  2018年   199篇
  2017年   155篇
  2016年   170篇
  2015年   212篇
  2014年   264篇
  2013年   366篇
  2012年   602篇
  2011年   605篇
  2010年   368篇
  2009年   363篇
  2008年   578篇
  2007年   586篇
  2006年   596篇
  2005年   555篇
  2004年   560篇
  2003年   489篇
  2002年   479篇
  2001年   235篇
  2000年   220篇
  1999年   184篇
  1998年   127篇
  1997年   107篇
  1996年   90篇
  1995年   109篇
  1994年   71篇
  1993年   76篇
  1992年   93篇
  1991年   95篇
  1990年   105篇
  1989年   89篇
  1988年   71篇
  1987年   78篇
  1986年   82篇
  1985年   88篇
  1984年   64篇
  1983年   68篇
  1982年   45篇
  1981年   44篇
  1980年   41篇
  1979年   51篇
  1978年   39篇
  1977年   33篇
  1974年   46篇
  1973年   40篇
  1971年   33篇
排序方式: 共有10000条查询结果,搜索用时 128 毫秒
41.
Hyperinfestation with Strongyloides is a severe complication in immunodepressed patients. It may present with various clinical signs, notably acute respiratory failure. Diagnosis may be difficult, particularly when the strongyloidiasis is associated with septicaemia caused by Gram-negative organisms. We report a new case of hyperinfestation with Strongyloides in a patient treated for periarteritis nodosa. This case was remarkable on two scores: the diagnosis problem raised by the presence of intrapulmonary haemorrhages, and the favourable outcome of an acute and initially severe respiratory failure which had required assisted ventilation. The role played in the patient's cure by the doses of thiabendazole given and the duration of their administration is discussed.  相似文献   
42.
Nosocomial infections are a preoccupation in a pediatric hospital mainly during the winter with bronchiolitis and gastroenteritis epidemics. We have examined the risk factors of nosocomial infections. MATERIAL AND METHODS: A prospective study was conducted between November, 1999 and March, 2000 in the infants units of the Le Havre hospital. We systematically listed the admissions and contacted the family after their discharge by phone. A geographic information system was implemented to display the epidemiological data; this software is able to illustrate the sectors at risk. RESULTS: During the study, 687 infants were hospitalized of whom 458 for bronchiolitis and community-acquired gastroenteritis. Mean age was 5.4 months old. No nosocomial bronchiolitis occurred. Prevalence of nosocomial gastroenteritis was 10% (68 cases including nine after discharge). Infants with nosocomial infection were younger than those with community-acquired infection (6.6 months vs. 11.2 months, P < 0.01). The mean length of stay was longer in nosocomial infection (7.7 vs. 4.1 days, P < 0.05). Among the infants with bronchiolitis, 16% have developed nosocomial intestinal infections (RR = 2.65, IC: 1.59-4.4; P < 0.01). The geographic analysis pointed the area with nosocomial risk (bedroom without water, nearness of nurse office and games room). CONCLUSION: Geographic information system is a part of the quality control system and may have some interaction effect on final decision making. Incidence of nosocomial infections showed the need for a prevention strategy in a pediatric hospital.  相似文献   
43.
44.
BACKGROUND: In 1992 France set up a national cystic fibrosis observatory (Observatoire national de la mucoviscidose, ONM) to monitor the state of health of patients on an annual basis. Using the ONM data, this study estimates the main indicators for life expectancy and assesses the total number of cystic fibrosis patients. METHODS: The data for the years 1994 to 2003 are divided into 3-year periods. Life tables are drawn up for these periods, from which mean and median lengths of life are determined. Using the most recent life table, the number of births in 2003 and the incidence of the disease, the total population of patients can be estimated, assuming a stationary population. RESULTS: In 2001-2003, life expectancy at birth of patients registered with the ONM was 39.1 years and median length of life was 36.4 years. These results, substantially better than those of 1994-1996, are linked to improved conditions of patient inclusion in the ONM database, to improvements in their healthcare, but also to the limitations of the life tables. Based on the 2003 data, the total theoretical number of patients is 6490, and coverage by the ONM database is thus 63.2%. CONCLUSIONS: These provisional results demonstrate the need to convert the ONM observatory into a registry providing exhaustive coverage of all patients.  相似文献   
45.
OBJECTIVE: This study analyzed the influence of the acquisition method in image-free computer-assisted total knee arthroplasty (CAS-TKA), and the reproducibility of implant planning using BoneMorphing, a 3D morphometric model obtained by a 3D-to-3D elastic registration of statistical models to sparse point clouds acquired directly on the bone surface with a pointer. MATERIALS AND METHODS: Five surgeons (one expert, four trainees) each performed a CAS-TKA hybrid protocol based on morphometric models and landmarks on a cadaveric knee 10 times. In addition, several additional landmarks were digitized during each acquisition. The reproducibility of the implant positioning and sizing, as determined by an implant planning algorithm with morphometric models, was compared to direct digitization accuracy. RESULTS: Femoral and tibial implant positioning parameters with the hybrid protocol resulted in intra-surgeon standard deviations (SDs) of less than+/-1.4 degrees for rotation and 1.9 mm for translation for all surgeons in all directions except for tibial axial rotation (the only parameter determined by a digitized landmark and not recomputed in the 3D model). The variability in individual landmark digitization varied from 2 to 5 mm SD for certain landmarks, with ranges of 15-25 mm across all surgeons. The comparison study showed an improvement in femoral rotation reproducibility with the morphometric model when using the posterior condylar axis. Tibial implant reproducibility for each method was comparable, with the morphometric model giving better results in well-digitized areas such as the tibial plateau. CONCLUSION: A CAS-TKA protocol based on a deformed statistical model offers reproducible implant positioning. Some landmarks, such as distal condyles, show sufficient reproducibility in the direction of interest, while others, such as the anterior tibial tubercle, can lead to hazardous implant positioning. This should be taken into consideration when designing a CAS-TKA system with bony landmarks. In areas where a sufficient number of points have been digitized with good coverage, such as on the distal and posterior femoral condyles or the tibial plateau areas, the information derived from the 3D model is more accurate and reproducible than that derived from digitization. Good training and a guiding user interface are essential to guarantee coverage quality.  相似文献   
46.
In this paper we describe the design and synthesis of 18 derivatives of the antimicrobial atovaquone which were substituted at the 3-hydroxy group by ester and ether functions. The compounds were evaluated in vitro for their activity against the growth of Plasmodium falciparum, the malaria causing parasite. All the compounds showed potent activity, with IC50 values in the range of 1.25–50 nM, comparable to those of atovaquone and much higher than chloroquine or quinine.  相似文献   
47.
48.
Clinical isolates of Campylobacter mucosalis.   总被引:4,自引:3,他引:1       下载免费PDF全文
  相似文献   
49.
50.
An experimental study was conducted in guinea pigs for the predictive assessment of the beryllium alloy hazard in occupational exposure of the skin to beryllium compounds. Guinea pigs were sensitized to beryllium sulfate according to the maximized Magnusson and Kligman test, and challenged with beryllium alloys and metallic copper, beryllium and aluminum samples. Results showed a delayed skin hypersensitivity reaction in 30 to 60% of pre-sensitized guinea pigs challenged with copper-beryllium alloys and aluminum-beryllium alloy. An inflammatory follicular reaction was induced by copper in both controls and pre-sensitized guinea pigs.  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