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   18823篇
  免费   1315篇
  国内免费   22篇
耳鼻咽喉   142篇
儿科学   576篇
妇产科学   400篇
基础医学   2587篇
口腔科学   187篇
临床医学   2204篇
内科学   4021篇
皮肤病学   343篇
神经病学   1654篇
特种医学   623篇
外科学   2691篇
综合类   45篇
一般理论   12篇
预防医学   1293篇
眼科学   559篇
药学   1241篇
中国医学   62篇
肿瘤学   1520篇
  2023年   101篇
  2022年   68篇
  2021年   261篇
  2020年   162篇
  2019年   292篇
  2018年   559篇
  2017年   424篇
  2016年   412篇
  2015年   524篇
  2014年   562篇
  2013年   790篇
  2012年   1501篇
  2011年   1549篇
  2010年   721篇
  2009年   579篇
  2008年   1351篇
  2007年   1493篇
  2006年   1395篇
  2005年   1437篇
  2004年   1438篇
  2003年   1345篇
  2002年   1291篇
  2001年   149篇
  2000年   126篇
  1999年   104篇
  1998年   73篇
  1997年   79篇
  1996年   72篇
  1995年   72篇
  1994年   50篇
  1993年   58篇
  1992年   68篇
  1991年   74篇
  1990年   67篇
  1989年   59篇
  1988年   52篇
  1987年   47篇
  1986年   62篇
  1985年   41篇
  1984年   56篇
  1983年   42篇
  1982年   41篇
  1981年   32篇
  1980年   32篇
  1979年   57篇
  1978年   36篇
  1977年   35篇
  1976年   31篇
  1974年   36篇
  1973年   36篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
Inhibitors of urinary stone formation in 40 recurrent stone formers   总被引:1,自引:0,他引:1  
The excretion of four inhibitors of urinary stone formation (zinc, magnesium, citrates and glycosaminoglycans (GAG) was studied in 20 normal controls and 40 recurrent calcium stone formers who were placed on a fixed diet restricted in calcium, oxalates and purines. We were unable to show any abnormality in the excretion of Zn, Mg or GAG. In 11 patients, a low level of urinary citrate was a significant feature that was associated in most cases with a urinary pH value above 6. Citrate concentration (per litre) and output (per 24 h) were found to be lower than in the controls in 19 and 33% respectively of the determinations. The overall ratio of average urinary citrate concentration in patients and controls was 0.56, a figure in agreement with previous data.  相似文献   
13.
14.
15.
This study evaluated factors influencing fracture (n = 197) and osteotomy (n = 200) healing in children with moderate to severe OI. Pamidronate treatment was associated with delayed healing after osteotomy, but not after fracture. The data suggest that both pamidronate and mechanical factors influence bone healing in this cohort. INTRODUCTION: Intravenous pamidronate is widely used to treat children with moderate to severe osteogenesis imperfecta (OI). However, the effect of this treatment on bone healing is not well characterized. We therefore retrospectively analyzed the healing of lower limb fractures and osteotomies in children with moderate to severe OI, both before and after the start of pamidronate treatment. MATERIALS AND METHODS: Bone healing was evaluated on standard radiographs after 197 lower limb fractures (132 femur and 65 tibia) in 82 patients (age at fracture, 0.0-19.9 years) and 200 intramedullary rodding procedures in 79 patients (age at surgery, 1.2-19.8 years). Delayed healing was diagnosed when a fracture or osteotomy line was at least partially visible 12 months after the event. RESULTS: Delayed fracture healing was observed more frequently during than before pamidronate treatment. However, the effect of pamidronate was no longer significant when age differences were taken into account (odds ratio [OR], 1.76; 95% CI, 0.61-5.10). Better mobility status was a strong independent predictor of delayed healing after fractures that occurred during pamidronate treatment. After osteotomies, delayed healing was more frequent when pamidronate had been started before surgery (OR, 7.29; 95% CI, 2.62-20.3), and this effect persisted after adjustment for multiple confounders. During pamidronate treatment, older age (OR per year of age, 1.25; 95% CI, 1.06-1.47) and osteotomy of the tibia (OR, 3.51; 95% CI, 1.57-7.82) were independent predictors of delayed healing. CONCLUSIONS: This study suggests that pamidronate therapy is associated with delayed healing of osteotomy sites after intramedullary rodding procedures. Better mobility status, but not pamidronate treatment, seems to be predictive of delayed healing after fractures.  相似文献   
16.
To determine the prevalence of excessive daytime sleepiness (EDS) and that of dozing and sudden onset of sleep episodes (SOS) while driving in ambulatory patients with Parkinson's disease (PD) in France, a national sample of private and public neurologists was asked to recruit the first 10 consecutive nondemented PD patients. Each patient completed a questionnaire including the Epworth Sleepiness Scale (ESS) and the likelihood of dozing off and experiencing SOS episodes behind the wheel. Clinical and demographic data were collected. One thousand six hundred and twenty‐five patients with PD were included in the survey. Twenty‐nine percent of the patients suffered from EDS (ESS score ≥10) but only 0.8% declared a high chance of dozing while driving and 0.5% reported totally unpredictable SOS episodes while driving. Risk factors for EDS were male gender, reduced activity of daily living, and a high daily levodopa equivalent dosage. Risk factors for SOS episodes while driving were an ESS score ≥10, male gender, and low Hoehn and Yahr staging. EDS is common in ambulatory patients with PD and is a major risk factor for dozing and for SOS episodes behind the wheel in patients who drive. © 2007 Movement Disorder Society  相似文献   
17.
18.
19.
Pharmacokinetics of prednisolone in children with the nephrotic syndrome   总被引:1,自引:0,他引:1  
The aim of this study was to establish whether the criteria for the clinical effectiveness of steroids are correlated with the pharmacokinetics of prednisolone in children treated with prednisone during an attack of idiopathic nephrotic syndrome (INS). Thirteen patients with nephrosis were included. Prednisolone, prednisone and cortisol levels were measured using a specific high-performance liquid chromatography assay after an oral dose of 1 mg/kg body weight of prednisone taken at the onset of the disease. All the pharmacokinetic parameters, including the conversion of prednisone to prednisolone were similar to the data already published in children with INS. No correlation was found between the values of pharmacokinetic parameters and criteria of clinical effectiveness. Hypo-albuminaemia was significantly correlated with the area under the plasma-concentration curve but not with the elimination half-life of prednisolone. Moreover, the prednisolone elimination half-life correlated with the urinary exretion of 17-hydroxycorticosteroids achieved in the first 6h. The present study suggests that routine measurements of prednisolone kinetics do not help when assessing the treatment of children with INS.  相似文献   
20.
A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. One primer set was used, from the published sequence of the common C. trachomatis plasmid. Detection of amplified sequences was carried out by agarose gel electrophoresis. Analysis of 106 clinical samples tested by cell culture and PCR showed a sensitivity of 100% when PCR was compared with cell culture.  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