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   2068篇
  免费   115篇
  国内免费   13篇
耳鼻咽喉   18篇
儿科学   22篇
妇产科学   37篇
基础医学   303篇
口腔科学   45篇
临床医学   142篇
内科学   344篇
皮肤病学   26篇
神经病学   209篇
特种医学   282篇
外科学   329篇
综合类   8篇
一般理论   2篇
预防医学   120篇
眼科学   46篇
药学   131篇
中国医学   3篇
肿瘤学   129篇
  2023年   20篇
  2022年   46篇
  2021年   80篇
  2020年   40篇
  2019年   39篇
  2018年   48篇
  2017年   45篇
  2016年   76篇
  2015年   82篇
  2014年   84篇
  2013年   102篇
  2012年   143篇
  2011年   131篇
  2010年   89篇
  2009年   66篇
  2008年   100篇
  2007年   109篇
  2006年   96篇
  2005年   112篇
  2004年   88篇
  2003年   74篇
  2002年   64篇
  2001年   42篇
  2000年   37篇
  1999年   37篇
  1998年   11篇
  1997年   8篇
  1996年   9篇
  1995年   7篇
  1994年   10篇
  1993年   13篇
  1992年   18篇
  1991年   16篇
  1990年   17篇
  1989年   7篇
  1988年   24篇
  1987年   21篇
  1986年   16篇
  1985年   20篇
  1984年   18篇
  1983年   12篇
  1982年   10篇
  1981年   8篇
  1980年   7篇
  1979年   12篇
  1978年   11篇
  1977年   6篇
  1976年   6篇
  1973年   6篇
  1971年   5篇
排序方式: 共有2196条查询结果,搜索用时 15 毫秒
1.
Editorial     
Ohne Zusammenfassung  相似文献   
2.
3.
4.
The aim of this study was to investigate the effect of a moderate soft tissue trauma to the course of fracture healing in a standardized animal model. Thirty-eight Wistar rats were randomly divided into a fracture group (F, n = 19) and a group with a fracture and a soft tissue trauma (F + STT, n = 19). The fracture and the soft tissue trauma were created using an impact device with a standardized energy. All fractures were stabilized by two Kirschner wires. Three rats were measured for blood flow and sacrificed at days 1, 3, 7, and 14, and seven rats at day 28, from both groups. A three-point bending test was performed on the healed tibia after 28 days. During the first 24 h there was a reduction in blood flow, which was more pronounced in the F + STT group than in the F group. From histological sections, the shape of the callus formation, as well as the tissue distribution of newly formed bone, fibrous cartilage and fibrous connective tissue were determined. Distinctly more periosteal new bone formed and a larger callus formed at days 3 and 7 in group F compared to group F + STT. However, by days 14 and 28, the ossification and overall callus size no longer showed differences between the two groups. A fast recovery of blood flow and callus formation took place in the F + STT group, which led to similar histological and biomechanical results in fracture healing observed after 28 days between the two groups.  相似文献   
5.
OBJECTIVES. Treatment and mortality risk were compared between prostate cancer patients receiving care in fee-for-service settings and those receiving care in a health maintenance organization (HMO). METHODS. Two samples were obtained from a population-based tumor registry. Patients in the first sample (n = 201) were interviewed shortly after diagnosis to obtain data on income, education, overall health status, and expenditures for health status, and expenditures for health care. These data were combined with information from the tumor registry on cancer stage, age, treatment, place of residence, and source of care. Only tumor registry data were obtained for most patients in the second sample (n = 962). For both samples, survival time was monitored for up to 80 months. RESULTS. Multivariate analysis of data from the interviewed sample indicated that HMO patients were less likely to receive surgery but more likely to receive radiation therapy than were those in fee-for-service settings. Mortality risk was lower for the HMO patients than for those in fee-for-service plans. Findings based on the second sample were nearly identical. CONCLUSIONS. This study suggests that HMOs may offer important advantages to lower-income patients at risk for specific life-threatening diseases.  相似文献   
6.
Malignancy is a major risk factor for venous thromboembolic events, but not all patients with malignancy develop such events. This study attempts to identify risk factors in patients with malignancy who develop venous thromboembolic events. In the current study, 566 consecutive patients without venous thromboembolic events and 416 patients with, admitted to University of Michigan with malignancy between 1992 and 2000, were identified using International Classification of Diseases-9 Clinical Modification codes. Data on potential risk factors was obtained from the University of Michigan Cancer Registry and the medical record. Univariate and multivariate analysis was used to identify factors associated with venous thromboembolic events and mortality. The mean patient age was 45.6 years with a mean survival of 7.8 years from cancer diagnosis. Venous thromboembolic events were associated with solid tumors (odds ratio 5.0; 95% confidence interval 1.7-14.9; P = 0.004), infection (4.9; 1.2-19.8; P = 0.03), and increasing age (1.05; 1.03-1.08; P < 0.001). While leukopenia (4.2; 1.2-14.6; P = 0.02) was associated with an increased incidence of venous thromboembolic events, neutropenia was not. Sex, type of therapy, and cancer stage were not independently associated with venous thromboembolic events. Survival was decreased in patients with venous thromboembolic events (5.9 versus 9.2 years, P < 0.0001). Solid tumors (3.9; 1.8-8.4; P = 0.001), infection (3.3; 1.1-9.9; P = 0.03), advanced stage (1.6; 1.2-2.1; P = 0.001), and increasing age (1.02; 1.0-1.04; P = 0.01) were associated with decreased survival. Patients with malignancy who have solid tumors, advanced age, infection, and leukopenia have a significantly increased risk of venous thromboembolic events.  相似文献   
7.
8.
The aim of this study was to estimate costs accrued by the health care of children with asthma in comparison to children with atopic eczema and seasonal rhinitis and to investigate cost determinants. From the multicenter cohort study (MAS-90), we selected children with an asthma, atopic eczema and/or seasonal rhinitis diagnosis during the first 8 years of life, and overall 8-year health care utilization was estimated retrospectively by reviewing medical records. Asthma treatment (n = 76) incurs an average cost of US$ 627 per year, 44% due to hospital stays. Atopic eczema treatment (n = 91) cost on average US$ 219 and seasonal rhinitis (n = 69) US$ 57 per year. In asthma and atopic eczema, costs increase significantly with disease severity. Allergy diagnostics use accounts for only 1% of total costs. Costs for asthma and atopic eczema treatment are highest in those years when topical steroids are used for the first time, but decrease with every further year of steroid use. A remarkable 25% of asthmatic children with severe symptoms were not treated according to national guidelines, so that most steroid treatment was initiated during the first hospital stay. In the case of asthma, total direct costs increased until the 3rd year of the disease, and then decreased with further years of diagnosis, while steroid use continued to increase. These results indicate a 'learning effect' in the treatment of asthma and atopic eczema for each patient as well as considerable cost-saving potential by preventing severe asthma. Moreover, the importance of considering cost-driving factors and using cohort or longitudinal designs in cost-of-illness approaches is emphasized.  相似文献   
9.
10.
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