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   1658篇
  免费   127篇
  国内免费   8篇
耳鼻咽喉   17篇
儿科学   48篇
妇产科学   42篇
基础医学   180篇
口腔科学   27篇
临床医学   184篇
内科学   277篇
皮肤病学   6篇
神经病学   174篇
特种医学   70篇
外科学   363篇
综合类   9篇
预防医学   122篇
眼科学   42篇
药学   117篇
中国医学   1篇
肿瘤学   114篇
  2022年   9篇
  2021年   27篇
  2020年   28篇
  2019年   46篇
  2018年   54篇
  2017年   28篇
  2016年   47篇
  2015年   56篇
  2014年   49篇
  2013年   79篇
  2012年   85篇
  2011年   76篇
  2010年   48篇
  2009年   52篇
  2008年   96篇
  2007年   82篇
  2006年   88篇
  2005年   99篇
  2004年   85篇
  2003年   104篇
  2002年   72篇
  2001年   17篇
  2000年   24篇
  1999年   26篇
  1998年   24篇
  1997年   18篇
  1996年   19篇
  1995年   17篇
  1994年   17篇
  1993年   12篇
  1992年   13篇
  1991年   12篇
  1990年   14篇
  1989年   9篇
  1988年   9篇
  1987年   9篇
  1986年   9篇
  1985年   20篇
  1984年   11篇
  1983年   17篇
  1982年   17篇
  1981年   14篇
  1980年   11篇
  1979年   20篇
  1978年   8篇
  1977年   10篇
  1976年   9篇
  1975年   8篇
  1972年   9篇
  1968年   9篇
排序方式: 共有1793条查询结果,搜索用时 15 毫秒
41.
Melanoma of the eye is a rare and distinct subtype of melanoma, which only rarely are familial. However, cases of uveal melanoma (UM) have been found in families with mixed cancer syndromes. Here, we describe a comprehensive search for inherited genetic variation in a family with multiple cases of UM but no aggregation of other cancer diagnoses. The proband is a woman diagnosed with UM at 16 years who within 6 months developed liver metastases. We also identified two older paternal relatives of the proband who had died from UM. We performed exome sequencing of germline DNA from members of the affected family. Exome‐wide analysis identified a novel loss‐of‐function mutation in the BAP1 gene, previously suggested as a tumor suppressor. The mutation segregated with the UM phenotype in this family, and we detected a loss of the wild‐type allele in the UM tumor of the proband, strongly supporting a causative association with UM. Screening of BAP1 germline mutations in families predisposed for UM may be used to identify individuals at increased risk of disease. Such individuals may then be enrolled in preventive programs and regular screenings to facilitate early detection and thereby improve prognosis. © 2013 Wiley Periodicals, Inc.  相似文献   
42.
43.
44.
45.
Variance electrocardiography (variance ECG) is a new resting procedure for detection of coronary artery disease (CAD). The method measures variability in the electrical expression of the depolarization phase induced by this disease. The time-domain analysis is performed on 220 cardiac cycles using high-fidelity ECG signals from 24 leads, and the phase-locked temporal electrical heterogeneity is expressed as a nondimensional CAD index (CAD-I) with the values of 0–150. This study compares the diagnostic efficiency of variance ECG and exercise stress test in a high prevalence population. A total of 199 symptomatic patients evaluated with coronary angiography was subjected to variance ECG and exercise test on a bicycle ergometer as a continuous ramp. The discriminant accuracy of the two methods was assessed employing the receiver operating characteristic curves constructed by successive consideration of several CAD-I cutpoint values and various threshold criteria based on ST-segment depression exclusively or in combination with exertional chest pain. Of these patients, 175 with CAD (≥ 50% luminal stenosis in 1 + major epicardial arteries) presented a mean CAD-I of 88 ± 22, compared with 70 ± 21 in 24 nonaffected patients (p < 0.01). Variance ECG provided a stochastically significant discrimination (p < 0.01) which was matched by exercise test only when chest pain variable was added to ST-segment depression as a discriminating criterion. Even then, the exercise test diagnosed single-vessel disease with a significantly lower sensitivity. At a cutpoint of CAD-I ≥ 70, compared with ST-segment depression ≥ 1 mm combined with exertional chest pain, the overall sensitivity of variance ECG was significantly higher (p < 0.01) than that of exercise test (79 vs. 48 %). When combined, the two methods identified 93% of coronary angiography positive cases. Variance ECG is an efficient diagnostic method which compares favorably with exercise test for detection of CAD in high prevalence population.  相似文献   
46.

Background and purpose

We have previously shown that during the first 2 years after total hip arthroplasty (THA), periprosthetic bone resorption can be prevented by 6 months of risedronate therapy. This follow-up study investigated this effect at 4 years.

Patients and methods

A single-center, double-blind, randomized placebo-controlled trial was carried out from 2006 to 2010 in 73 patients with osteoarthritis of the hip who were scheduled to undergo THA. The patients were randomly assigned to receive either 35 mg risedronate or placebo orally, once a week, for 6 months postoperatively. The primary outcome was the percentage change in bone mineral density (BMD) in Gruen zones 1 and 7 in the proximal part of the femur at follow-up. Secondary outcomes included migration of the femoral stem and clinical outcome scores.

Results

61 of the 73 patients participated in this 4-year (3.9- to 4.1-year) follow-up study. BMD was similar in the risedronate group (n = 30) and the placebo group (n = 31). The mean difference was −1.8% in zone 1 and 0.5% in zone 7. Migration of the femoral stem, the clinical outcome, and the frequency of adverse events were similar in the 2 groups.

Interpretation

Although risedronate prevents periprosthetic bone loss postoperatively, a decrease in periprosthetic BMD accelerates when therapy is discontinued, and no effect is seen at 4 years. We do not recommend the use of risedronate following THA for osteoarthritis of the hip.Adaptive bone remodeling around the femoral stem following total hip arthroplasty (THA) results in regional loss of bone mass, especially in proximal parts of the femur—most of which takes place within the first postoperative year (Bodén et al. 2006, Sköldenberg et al. 2006). Periprosthetic bone loss may predispose to periprosthetic fracture, aseptic loosening, and difficulties at revision surgery (Lindahl 2007, Streit et al. 2011, Sköldenberg et al. 2014).The bisphosphonate (BP) risedronate has been used successfully to prevent osteoporotic fractures, mainly in the hip and vertebrae, by inhibiting osteoclast activity (McClung et al. 2001). In recent years, the possible use of BPs to prevent or ameliorate periprosthetic adaptive bone resorption, osteolysis, and implant migration has been investigated thoroughly in animal models and humans. The short-term results of several studies showing the effects of postoperative BP treatment in reducing periprosthetic bone loss up to a year after the arthroplasty have already been published (Venesmaa et al. 2001, Wilkinson et al. 2001, Hennigs et al. 2002, Wilkinson et al. 2005, Arabmotlagh et al. 2006).We have previously found that risedronate given once a week for 6 months after THA reduces periprosthetic bone resorption around an uncemented femoral stem in the first and second postoperative year (Sköldenberg et al. 2011). We now report the 4-year outcome in the same cohort.  相似文献   
47.
BACKGROUND: Budesonide, a widely used inhaled corticosteroid (ICS) with a favorable therapeutic ratio, is available via a dry powder inhaler (Pulmicort Turbuhaler) and as a suspension for nebulization (Pulmicort Respules). METHODS: MEDLINE and an AstraZeneca database were searched to identify relevant controlled clinical trials published between 1986 and 2002 using the key words budesonide OR inhaled corticosteroid, AND once daily. RESULTS: Thirty-four controlled clinical studies involving once-daily administration of budesonide to asthmatic patients were identified. Excluding long-term studies, this review presents data from 23 controlled studies for 4466 adults or adolescents and 1532 children with asthma and demonstrates efficacy of budesonide in both corticosteroid-na?ve patients and patients previously treated with ICS. Once-daily administration of budesonide achieves clinical efficacy comparable with that of twice-daily regimens in patients with mild-to-moderate asthma and is equally effective when given in the morning or evening. Once-daily administration simplifies treatment regimens and may improve patient compliance. The tolerability profiles of budesonide once-daily via Turbuhaler or as budesonide inhalation suspension are good and comparable with those for twice-daily dosing. CONCLUSIONS: Once-daily budesonide is effective and well tolerated as initial treatment for adults and children with mild asthma and as maintenance therapy in patients with more severe asthma once asthma control has been achieved.  相似文献   
48.
The aim of this study was to investigate the degree of satisfaction with housing and housing support for people with psychiatric disabilities in Sweden. A total of 370 residents, in supported housing and in ordinary housing with housing support, completed a new questionnaire and reported a high degree of overall satisfaction, but many of them wanted to move somewhere else. Differences were found between the two different types of housing concerning satisfaction with housing support, social life and available choices. Security and privacy, as well as other's influence on the choice of residential area and dwelling proved to be important predictors for satisfaction.  相似文献   
49.
50.
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