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   44749篇
  免费   2773篇
  国内免费   555篇
耳鼻咽喉   531篇
儿科学   2315篇
妇产科学   739篇
基础医学   5156篇
口腔科学   1006篇
临床医学   3490篇
内科学   8027篇
皮肤病学   930篇
神经病学   2086篇
特种医学   1176篇
外科学   5726篇
综合类   3727篇
现状与发展   1篇
一般理论   15篇
预防医学   3154篇
眼科学   1655篇
药学   4505篇
  12篇
中国医学   1209篇
肿瘤学   2617篇
  2023年   373篇
  2022年   959篇
  2021年   1552篇
  2020年   997篇
  2019年   1020篇
  2018年   1255篇
  2017年   986篇
  2016年   1171篇
  2015年   1366篇
  2014年   1785篇
  2013年   2288篇
  2012年   3279篇
  2011年   3242篇
  2010年   2128篇
  2009年   1950篇
  2008年   2418篇
  2007年   2380篇
  2006年   2251篇
  2005年   1793篇
  2004年   1693篇
  2003年   1421篇
  2002年   1196篇
  2001年   999篇
  2000年   1010篇
  1999年   790篇
  1998年   337篇
  1997年   231篇
  1996年   253篇
  1995年   238篇
  1994年   192篇
  1993年   160篇
  1992年   506篇
  1991年   415篇
  1990年   434篇
  1989年   402篇
  1988年   362篇
  1987年   361篇
  1986年   352篇
  1985年   330篇
  1984年   270篇
  1983年   222篇
  1982年   147篇
  1979年   231篇
  1978年   151篇
  1977年   181篇
  1975年   173篇
  1974年   182篇
  1973年   182篇
  1972年   174篇
  1971年   161篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Thyroid function tests were performed on 16 clinically euthyroid patients with end-stage renal failure undergoing regular haemodialysis or continuous ambulatory peritoneal dialysis and compared with 8 healthy subjects. The patient groups were carefully matched, especially regarding relative duration of dialysis (mean of 24 months). Total serum thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine and reverse triiodothyronine were significantly lower in both patient groups than control. The thyrothrophin response to the standard thyrotrophin-releasing hormone test was delayed and blunted. Using a novel concentration technique we measured loss of T4 in peritoneal dialysate effluent and found it to be approximately 10% of daily thyroidal T4 release.  相似文献   
72.
73.
74.
目的设计一套用于组织工程小血管内壁摩擦力测量的装置并对组织工程血管的材料进行初步的测量,以验证装置的可靠性和相关结论。方法根据血液动力学的原理,对血管的力学模型进行分析,确定组织工程血管内皮细胞摩擦力的测量方法,从而设计完成整套装置并对弹性元件进行测量,并进行组织工程降解材料聚羟基乙酸PGA构成的管状支架进行摩擦力的测量。结果设计完成了测量组织工程血管内壁摩擦力的实验装置,弹性元件的牵拉力与位移的关系呈良好的线性关系。聚羟基乙酸PGA管状支架的摩擦力随流速的增加而增加。结论测量组织工程血管内壁摩擦力的实验装置是可行的,聚羟基乙酸PGA管状支架的摩擦力与流速基本呈现线性关系。  相似文献   
75.
76.
A case of organophosphate (OP) poisoning who recovered after requiring almost 1000 mg of atropine, 10 gm of PAM and ventilatory support for 7 days is presented here. The overview of organophosphate poisoning and its management is given. With the approach adopted, the mortality reported in the general medicine unit in the central hospital in Nepal is 7.4%. The two important aspects of the management are vigilance of the atropine drip, especially at night, and other physical and psychological support care of the patients.  相似文献   
77.
Exposure to air pollution affects pulmonary functions adversely. Effect of exposure to pollution on diurnal variation of peak flow was assessed in healthy students. Three hundred healthy age-matched nonsmoker students were studied. They were categorized into two groups on the basis of their residence: commuters and living on campus. Peak expiratory flow (PEF) recordings were made twice daily for 2 days with the Pink City Flow Meter. The measurement was then used to calculate for each subject the amplitude percentage mean, which is an index for expressing PEF variability for epidemiological purposes (Higgins BG, Britton JR, Chinns Jones TD, Jenkinson D, Burnery PG, Tattersfield AE. Distribution of peak expiratory flow variability in a population sample. Am Rev Respir Dis 1989; 140:1368-1372). Air pollution parameters were quantified by measurement of sulfur dioxide (SO2), oxides of nitrogen (NO2), carbon monoxide (CO), and respirable suspended particulate matter (RSPM) in the ambient air at the campus and on the roadside. The mean values of PEF variability (amplitude percent mean) in the students living on campus and in the commuters were 5.7 +/- 3.2 and 11 +/- 3.6, respectively (P < .05). Among the commuters, maximum number of subjects showed amplitude percentage mean PEFR at the higher end of variability distribution, as compared to the students living on campus, among whom the majority of subjects fell in the lower ranges of variability distribution. The ambient air quality parameters, namely SO2, NO2, CO, and RSPM were significantly lower on the campus. It can be concluded that long-term periodic exposure to air pollution can lead to increased PEF variability even in healthy subjects. Measurement of PEF variability may prove to be a simple test to measure effect of air pollution in healthy subjects.  相似文献   
78.
OBJECTIVES: The purpose of this study was to determine quality of life (QOL) and exercise performance (EP) in patients with persistent atrial fibrillation (AF) converted to sinus rhythm (SR) compared with those remaining in or reverting to AF. BACKGROUND: Restoration of SR in patients with AF improving QOL and EP remains controversial. METHODS: Patients with persistent AF were randomized double-blind to amiodarone, sotalol, or placebo. Those not achieving SR at day 28 were cardioverted and classified into SR or AF groups at 8 weeks (n = 624) and 1 year (n = 556). The QOL (SF-36), symptom checklist (SCL), specific activity scale (SAS), AF severity scale (AFSS), and EP were assessed. RESULTS: Favorable changes were seen in SR patients at 8 weeks in physical functioning (p < 0.001), physical role limitations (p = 0.03), general health (p = 0.002), and vitality (p < 0.001), and at 1 year in general health (p = 0.007) and social functioning (p = 0.02). Changes in the scores for SCL severity (p = 0.01), functional capacity (p = 0.003), and AFSS symptom burden (p < 0.001) at 8 weeks and in SCL severity (p < 0.01) and AF symptom burden (p < 0.001) at 1 year showed significant improvements in SR versus AF. Symptomatic patients were more likely to have improvement. The EP in SR versus AF was greater from baseline to 8 weeks (p = 0.01) and to 1 year (p = 0.02). The EP correlated with physical functioning and functional capacity except in the AF group at 1 year. CONCLUSIONS: In patients with persistent AF, restoration and maintenance of SR was associated with improvements in QOL measures and EP. There was a strong correlation between QOL measures and EP.  相似文献   
79.
Graft thrombosis is the most common cause of first year graft failure in pediatric renal transplantation. The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database was analyzed for cases of graft failure due to thrombosis among patients transplanted from 1998 to 2004. The impact of interleukin-2 (IL-2) receptor antagonists as induction therapy was determined. There were a total of 51 graft failures due to thrombosis among the 2750 reported renal transplants (1.85%) (95% CI (1.39%, 2.41%)). This represents the most common cause of graft loss during the first year post-transplant accounting for 35% of first year losses and 18% of all graft losses. The incidence of thrombosis among patients who received IL-2 receptor antibodies was 1.07% (12/1126) compared to 2.40% (39/1624) among patients who did not (OR 0.44, 95% CI 0.23, 0.84, p = 0.014). Use of IL-2 receptor blockade was the only significant prognostic factor in a multivariate model with previously identified risk factors. Analysis of NAPRTCS data found that the use of IL-2 receptor antibodies as induction therapy is associated with a significantly decreased risk of graft failure due to thrombosis. This provocative finding requires further investigation to determine whether thrombotic failure can be decreased by this therapeutic strategy.  相似文献   
80.
Phaeohyphomycosis is a disease caused by dematiaceous fungi. Here, the first culture-proven case of mediastinal mass due to Fonsecaea pedrosoi is reported. The patient was a 40-yr-old male who had presented with history of dyspnoea and dysphagia. Computed tomography of the chest disclosed a mediastinal mass. Cultures of a specimen from the mediastinum grew Fonsecaea pedrosoi. The patient received amphotericin B and itraconazole and showed a remarkable recovery. Repeat computed tomography revealed a reduction in the mediastinal mass. The case highlights the need for a high degree of clinical suspicion and appropriate histopathological and mycological examination of clinical specimens.  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