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   1841篇
  免费   205篇
  国内免费   23篇
耳鼻咽喉   43篇
儿科学   88篇
妇产科学   18篇
基础医学   283篇
口腔科学   97篇
临床医学   189篇
内科学   298篇
皮肤病学   53篇
神经病学   129篇
特种医学   262篇
外科学   182篇
综合类   38篇
一般理论   2篇
预防医学   122篇
眼科学   47篇
药学   80篇
  1篇
肿瘤学   137篇
  2022年   9篇
  2021年   23篇
  2020年   21篇
  2019年   26篇
  2018年   30篇
  2017年   18篇
  2016年   24篇
  2015年   39篇
  2014年   39篇
  2013年   75篇
  2012年   70篇
  2011年   56篇
  2010年   73篇
  2009年   74篇
  2008年   62篇
  2007年   76篇
  2006年   61篇
  2005年   60篇
  2004年   54篇
  2003年   64篇
  2002年   52篇
  2001年   52篇
  2000年   32篇
  1999年   52篇
  1998年   94篇
  1997年   91篇
  1996年   64篇
  1995年   58篇
  1994年   42篇
  1993年   53篇
  1992年   26篇
  1991年   46篇
  1990年   25篇
  1989年   53篇
  1988年   48篇
  1987年   33篇
  1986年   30篇
  1985年   27篇
  1984年   22篇
  1983年   21篇
  1982年   19篇
  1981年   19篇
  1980年   24篇
  1979年   14篇
  1978年   23篇
  1977年   12篇
  1976年   14篇
  1975年   14篇
  1972年   9篇
  1971年   9篇
排序方式: 共有2069条查询结果,搜索用时 15 毫秒
1.
2.
3.
Pyomyositis: characteristics at CT and MR imaging   总被引:9,自引:0,他引:9  
Gordon  BA; Martinez  S; Collins  AJ 《Radiology》1995,197(1):279
  相似文献   
4.
BACKGROUND: Sore throat is a common symptom presented to general practitioners (GPs), and there remains controversy about the appropriate use of antibiotics. AIM: To compare, in a randomized controlled trial, the effectiveness of penicillin, cefixime and placebo on symptom resolution in patients presenting with a sore throat in general practice. METHOD: Twenty-two GPs in Avon recruited 154 patients, aged 16-60 years, presenting to their GP with a sore throat, and for whom the GP would normally prescribe an antibiotic. Patients were randomized to one of three groups: penicillin V 250 mg four times a day; cefixime 200 mg daily; and placebo. Each was prescribed for five days. The main outcome measures were a diary of symptom resolution over seven days and eradication of group A beta-haemolytic streptococcus (GABHS). RESULTS: Of the 103 (67%) patients who completed symptom diaries, 40 were allocated to receive penicillin, 29 cefixime and 34 placebo. In the analysis including all patients, symptom resolution was greater by day 3 in the cefixime group than in the placebo group. Penicillin did not improve symptom resolution by day 3 compared with placebo, and cefixime was not statistically significantly different from penicillin. There were significant differences in the proportion of patients using analgesia at day 3, with the proportion being lowest in the cefixime group. The results for the subgroup of patients without GABHS were similar to those for all patients; in particular, the only statistically significant difference was between cefixime and placebo. Although numbers were too small for statistical significance, among patients with GABHS the effects of penicillin and cefixime were similarly raised in relation to placebo. CONCLUSION: Compared with placebo, cefixime can improve the rate of resolution of symptoms in patients with a sore throat who are selected for antibiotic treatment by their GP. The unexpected finding that cefixime was of benefit compared with placebo for patients without GABHS suggests that bacteria other than GABHS may be important in the pathogenesis of sore throat.  相似文献   
5.
SUMMARY A case is reported of pseudohyperphosphataemia in association with a monoclonal gammopathy of undetermined significance.  相似文献   
6.
7.
High-frequency respiratory impedance data measured noninvasively by the high-speed interrupter technique (HIT), particularly the first antiresonance frequency (f(ar,1)), is related to airway wall mechanics. The aim of this study was to evaluate the feasibility and repeatability of HIT in unsedated pre-term infants, and to compare values of f(ar,1) from 18 pre-term (post-conceptional age 32-37 weeks, weight 1,730-2,910 g) and 18 full-term infants (42-47 weeks, 3,920-5,340 g). Among the pre-term infants, there was good short-term repeatability of f(ar,1) within a single sleep epoch (mean (sd) coefficient of variance: 8 (1.7)%), but 95% limits of agreement for repeated measures of f(ar,1) after 3-8 h were relatively wide (-41 Hz; 37 Hz). f(ar,1) was significantly lower in pre-term infants (199 versus 257 Hz), indicating that wave propagation characteristics in pre-term airways are different from those of full-term infants. The present authors suggest that this is consistent with developmental differences in airway wall structure and compliance, including the influence of the surrounding tissue. Since flow limitation is determined by wave propagation velocity and airway cross-sectional area, it was hypothesised that the physical ability of the airways to carry large flows is fundamentally different in pre-term than in full-term infants.  相似文献   
8.
BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005.  相似文献   
9.
SUMMARY Impotence is a common symptom which can cause considerable distress to both the sufferer and his partner. The use of pharmacotherapy to improve erectile function will continue to increase as safe and effective drugs are developed. However, restoring erectile function should not be the only treatment objective. It is also essential to address personal and emotional factors in the sufferer, conflicts in his relationship with his partner, and sexual problems in his partner, all of which may be instrumental in causing or maintaining the presenting impotence. We advocate a combined approach with appropriate medical treatment and sex and couple therapy  相似文献   
10.
Acute appendicitis: CT and US correlation in 100 patients   总被引:19,自引:1,他引:18  
  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