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   8576篇
  免费   716篇
  国内免费   34篇
耳鼻咽喉   36篇
儿科学   246篇
妇产科学   127篇
基础医学   963篇
口腔科学   249篇
临床医学   850篇
内科学   2198篇
皮肤病学   221篇
神经病学   813篇
特种医学   501篇
外科学   1112篇
综合类   161篇
一般理论   28篇
预防医学   695篇
眼科学   290篇
药学   456篇
  1篇
中国医学   20篇
肿瘤学   359篇
  2022年   64篇
  2021年   133篇
  2020年   100篇
  2019年   161篇
  2018年   186篇
  2017年   146篇
  2016年   129篇
  2015年   156篇
  2014年   187篇
  2013年   311篇
  2012年   379篇
  2011年   432篇
  2010年   293篇
  2009年   243篇
  2008年   383篇
  2007年   398篇
  2006年   414篇
  2005年   374篇
  2004年   305篇
  2003年   353篇
  2002年   264篇
  2001年   191篇
  2000年   186篇
  1999年   196篇
  1998年   151篇
  1997年   134篇
  1996年   114篇
  1995年   120篇
  1994年   100篇
  1993年   93篇
  1992年   167篇
  1991年   159篇
  1990年   139篇
  1989年   172篇
  1988年   164篇
  1987年   163篇
  1986年   146篇
  1985年   133篇
  1984年   112篇
  1983年   75篇
  1982年   60篇
  1979年   93篇
  1978年   90篇
  1977年   69篇
  1976年   59篇
  1975年   57篇
  1974年   68篇
  1973年   61篇
  1972年   62篇
  1971年   59篇
排序方式: 共有9326条查询结果,搜索用时 15 毫秒
1.
2.
Various cases are presented demonstrating the role of computed tomography (CT) in the assessment of serosal and bowel wall pathology. Reference is made to the morphology of the lesions. Illustrative examples of tumors, secondary malignant dissemination, irradiation injury to the gut, and intramural gas associated with ulcerative colitis, are all illustrated.  相似文献   
3.
4.
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   
5.
It was hypothesized that members of an older cohort of seriously mentally ill community mental health clients would develop stronger alliances with intensive case managers. Eighty-six clients participating in a study of case management services completed a measure of working alliance and structured interviews. It was found that older cohort clients, those age 45 or older, showed much stronger alliances with their case managers than younger clients.This research is funded by NIMH/SAMHSA grant R18MH46082.  相似文献   
6.
The optimum therapy for cryptococcal meningitis in patients with the acquired immunodeficiency syndrome (AIDS) remains unresolved. Traditional therapy consists of amphotericin B with or without flucytosine. Obstacles exist in administering these agents to patients with AIDS. Mortality rates during initial therapy are relatively high. Given the lack of proved benefit, we do not recommend adding flucytosine to amphotericin B routinely. The search for more efficacious and less toxic agents continues. The oral triazoles, especially fluconazole, have increased the options for treatment of this disease. New strategies and novel approaches in managing cryptococcal meningitis in patients with AIDS continue to be developed.  相似文献   
7.
W L Young  I Prohovnik  E Ornstein  N Ostapkovich  M B Sisti  R A Solomon  B M Stein 《Neurosurgery》1990,27(2):257-66; discussion 266-7
To investigate the cerebral hemodynamic changes associated with obliteration of arteriovenous malformations (AVMs), we studied 26 patients undergoing total microsurgical AVM resection during isoflurane and N2/O2 anesthesia. Detectors were placed 5 to 6 cm from the margin of the lesion and in a homologous contralateral position. Cerebral blood flow (CBF) was measured using the intravenous xenon-133 technique before and after AVM resection, during both hypocapnia and normocapnia at each stage. Intraoperative changes in CBF were related to a risk score system based on the patient's history and preoperative angiograms. Seven otherwise healthy patients undergoing spinal surgery were studied to control for anesthetic effects. Patient demographic and clinical data for the AVM group conformed to the expected strata of a large AVM population. The CBF increased after excision (22 +/- 1 ml/100 g/min before excision to 30 +/- 2 ml/100 g/min after excision; mean +/- SE, n = 25, P less than 0.002) without a hemispheric difference. CO2 reactivity increased slightly after excision (4.2 +/- 0.3% change/mm Hg before excision to 4.7 +/- 0.3% change/mm Hg after excision; n = 14, P less than 0.02). The baseline CBF and CO2 reactivity were not different from the control group. There was a weak correlation between the risk score and the percentage of change in the ipsilateral CBF, with a trend for the patients with the lowest risk to have the lowest CBF changes after resection. There was no relationship between CO2 reactivity and risk grade. None of the patients awoke from anesthesia with unexpected neurological deficits. The highest CBF increases were associated with postoperative brain swelling in one patient and fatal intracerebral hemorrhage in another. Both patients had normal CO2 reactivity before excision. One patient suffered postoperative intracerebral hemorrhage, attributable to technical problems, and had no increase in CBF. We conclude that, with an acute increase in the arteriovenous pressure gradient (and cerebral perfusion pressure) that results from shunt obliteration, there is an immediate global effect of AVM resection to increase CBF. Cerebrovascular reactivity to CO2 remains intact both before and after excision.  相似文献   
8.
9.
10.
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   
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