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   8773篇
  免费   978篇
  国内免费   19篇
耳鼻咽喉   77篇
儿科学   298篇
妇产科学   187篇
基础医学   1220篇
口腔科学   280篇
临床医学   982篇
内科学   1670篇
皮肤病学   107篇
神经病学   889篇
特种医学   308篇
外科学   1190篇
综合类   323篇
一般理论   7篇
预防医学   993篇
眼科学   285篇
药学   531篇
中国医学   4篇
肿瘤学   419篇
  2021年   136篇
  2020年   111篇
  2019年   152篇
  2018年   157篇
  2017年   136篇
  2016年   115篇
  2015年   137篇
  2014年   194篇
  2013年   339篇
  2012年   393篇
  2011年   418篇
  2010年   241篇
  2009年   221篇
  2008年   364篇
  2007年   381篇
  2006年   390篇
  2005年   365篇
  2004年   356篇
  2003年   281篇
  2002年   309篇
  2001年   283篇
  2000年   279篇
  1999年   260篇
  1998年   111篇
  1997年   100篇
  1996年   100篇
  1995年   95篇
  1994年   83篇
  1993年   84篇
  1992年   210篇
  1991年   186篇
  1990年   208篇
  1989年   214篇
  1988年   195篇
  1987年   160篇
  1986年   158篇
  1985年   169篇
  1984年   117篇
  1983年   110篇
  1982年   79篇
  1981年   64篇
  1979年   118篇
  1978年   96篇
  1977年   80篇
  1976年   66篇
  1975年   61篇
  1974年   72篇
  1973年   96篇
  1972年   88篇
  1971年   76篇
排序方式: 共有9770条查询结果,搜索用时 15 毫秒
41.
42.
The performance of a lateral-flow immunoassay, the QuickVue Influenza Test, for detection of influenza A and B viruses in comparison with that of cell culture was evaluated by using nasopharyngeal aspirates, in viral transport medium, from children with respiratory tract infections. The sensitivity and specificity were 79.2 and 82.6%, respectively.  相似文献   
43.
44.
45.
Macran  S.  Kind  P.  Collingwood  J.  Hull  R.  McDonald  I.  Parkinson  L. 《Quality of life research》2003,12(2):177-188
This study reports on the preliminary testing of a new measure designed for use alongside EQ-5D in evaluating outcomes in podiatry: the Podiatry Health Questionnaire (PHQ). Individuals aged 18 years or more, receiving podiatry services in clinic or domicilliary locations across four NHS Trusts in Yorkshire and Humberside UK took part in a questionnaire survey. Respondents reported high levels of problems on all six PHQ dimensions. Correlations suggested that the PHQ and EQ-5D were measuring distinct constructs. The levels on each dimension were well defined in terms of self-rated morbidity on the PHQ visual analogue scale (PHQvas) and the EQ-5Dvas, although PHQvas appeared to be slightly more sensitive to changes in health on the dimensions. There was a strong relationship between clinicians' Podiatry Clinical Score rating and reported symptoms for four out of six PHQ dimensions and PHQvas. The PHQ was able to distinguish respondents in terms of their self-reported morbidity in EQ-5D and in terms of their morbidity as assessed by clinicians. It is suggested that the respondent completed PHQ appears to be a useful new measure for assessing foot-related health. However, further investigation of the psychometric properties of the measure is required.  相似文献   
46.
OBJECTIVE: Clinical reports over the last 60 years suggest that the amobarbital interview is effective in relieving catatonic symptoms. This has never been substantiated with methodologically sound trials. The authors postulated that a randomized blind comparison of intravenous amobarbital and saline would demonstrate the superiority of amobarbital in relieving catatonic mutism. METHOD: The subjects were 20 inpatients with catatonic mutism. They were randomly assigned to either saline (N = 10) or a 5% amobarbital solution (N = 10), and the infusions were administered intravenously at a rate of 1 cc/min or less over 10 minutes by a blinded physician. A second blinded physician administered a semistructured interview during the infusion to control for the effect of suggestion. A third blinded physician rated patient responsiveness, reactivity, and arousal. Any patient who was unresponsive to the initial infusion was crossed over to the other infusion. Interviews were videotaped for determination of interrater reliability. RESULTS: In the initial infusions, six of 10 patients responded to amobarbital and zero of 10 responded to saline. Four of the saline nonresponders responded when given amobarbital. Response was evident by the 4th minute of the amobarbital infusion. Interrater reliability was high. The responders and nonresponders differed significantly in the variance of the weight-adjusted amobarbital dose, and the responders tended to be older and female. CONCLUSIONS: Intravenous amobarbital is superior to saline in relieving catatonic mutism, although only 50% of these patients responded. The nonresponders were distinguished from the responders by a greater variance in the weight-adjusted dose of amobarbital.  相似文献   
47.
48.
Transplant arteriosclerosis in a rat aortic model.   总被引:6,自引:1,他引:5       下载免费PDF全文
Transplant arteriosclerosis (TA) has emerged as an obstacle to the long-term survival of transplanted organs, especially cardiac transplants. The animal models that have been used to study TA have not been fully characterized with regard to features such as the time course of cell proliferation and the sequence of cell types arriving in the developing intimal lesion. We present a model of TA based on a transplanted segment of abdominal aorta that helps address these questions. Two strains of rats (PVG x DA) underwent orthotopic aortic transplantation without immunosuppression and were killed at 14, 20, 40, and 60 days after transplantation. The within-strain control group displayed minimal evidence of cellular rejection with minimal to absent intimal lesions. In contrast, the allograft group showed a linearly increasing intimal lesion, up through 60 days after transplantation. The mechanism of intimal thickening was by an increase in cell number at the earlier time points with the later deposition of extracellular matrix. The early intimal lesion consisted mostly of mononuclear inflammatory cells (45%) with gradually increasing presence of smooth muscle cells (SMC) in the intima between 20 and 60 days. Conversely, the media showed gradual infiltration by macrophage-type cells with virtual loss of all SMC from the media by 40 days. The proliferative index showed a peak of 6% and 8% at 20 days in both the intima and media, respectively, and was preceded by the presence of macrophages. In fact, most of the proliferating cells at the earlier time points were either monocytes/macrophages, or were immediately adjacent to monocyte-/macrophage-rich regions. This straight artery segment model of transplant arteriosclerosis provides an easily quantifiable system in which the effects of different interventions (e.g., immunosuppressive regimens) can be tested.  相似文献   
49.
We report a unique case of coexistingexogenous lipoid pneumonia, endogenous lipoid pneumonia (EU), and pulmonary alveolar proteinosis (PAP) in a 5-year-old patient with severe neurodevelop mental disease. The patient presented with gastroesophageal reflux and presumed chronic lung disease resulting from recurrent aspiration pneumonias and succumbed to respiratory failure. The autopsy showed lipid-laden macrophages and periodic acid-SchiJf9ositive granular matm'al i n alveolar spaces and multilamellated structures within both alveolar macrophages and extracellular debris.

These findings were similar to those in previous reports of coexisting E I P and PAP in the setting of gastroesophageal refux [I] . However, the present case diJfered by the presence of scattered large osmiophilic extracellular lipid vacuob. Besides strengthening the association between EIP and PAP and their relationship to gastroesophageal refux, this case suggests that t h q may arise together with exogenous lipoid pneumonia, through related mechanisms, in the setting of neurodevelopmental disease.  相似文献   
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