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   1899篇
  免费   136篇
  国内免费   24篇
耳鼻咽喉   14篇
儿科学   91篇
妇产科学   29篇
基础医学   291篇
口腔科学   22篇
临床医学   181篇
内科学   606篇
皮肤病学   20篇
神经病学   102篇
特种医学   144篇
外科学   163篇
综合类   28篇
预防医学   209篇
眼科学   14篇
药学   73篇
肿瘤学   72篇
  2022年   21篇
  2021年   18篇
  2020年   13篇
  2019年   19篇
  2018年   21篇
  2017年   20篇
  2016年   26篇
  2015年   29篇
  2014年   43篇
  2013年   45篇
  2012年   61篇
  2011年   60篇
  2010年   60篇
  2009年   39篇
  2008年   64篇
  2007年   76篇
  2006年   77篇
  2005年   78篇
  2004年   64篇
  2003年   61篇
  2002年   55篇
  2001年   72篇
  2000年   59篇
  1999年   46篇
  1998年   43篇
  1997年   28篇
  1996年   28篇
  1995年   36篇
  1994年   22篇
  1993年   22篇
  1992年   35篇
  1991年   43篇
  1990年   40篇
  1989年   66篇
  1988年   51篇
  1987年   57篇
  1986年   53篇
  1985年   50篇
  1984年   22篇
  1983年   27篇
  1982年   16篇
  1981年   24篇
  1980年   27篇
  1979年   20篇
  1978年   24篇
  1977年   16篇
  1976年   18篇
  1975年   22篇
  1974年   16篇
  1973年   17篇
排序方式: 共有2059条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
Previous studies have suggested that corticotropin-releasing factor (CRF) has immunoregulatory effects in addition to its neuroendocrine role. We examined the ability of CRF to inhibit lipopolysaccharide (LPS)-induced pulmonary vascular leak in vivo. Female BALB/C mice were treated with either normal saline (NS) or CRF prior to injection with LPS. Pulmonary vascular leak was inhibited by CRF as assessed by measurement of lung wet-to-dry ratios. The stress-induced increase in serum corticosterone levels in mice injected with LPS alone was not further increased by treatment with CRF. This indicates that the effect of CRF was not mediated centrally by stimulation of endogenous steroid release. Histologic examination of the lungs revealed that leukocyte infiltration was significantly depressed in CRF-treated mice thus confirming the protective effect of CRF. In addition, a modest prolongation of survival was demonstrated in CRF-treated mice following challenge with LPS (p=.08). These data indicate the potential utility of CRF as a modulator of pulmonary vascular leak.  相似文献   
8.
In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients.  相似文献   
9.
OBJECTIVES. Primary care medical clinics are good settings for smoking interventions. This study extends this strategy with a smokeless tobacco intervention delivered by dentists and dental hygienists in the course of routine dental care. METHODS. Male users of moist snuff and chewing tobacco (n = 518) were identified by questionnaire in clinic waiting rooms and then randomly assigned to either usual care or intervention. The intervention included a routine oral examination with special attention to the part of the mouth in which tobacco was kept and an explanation of the health risks of using smokeless tobacco. After receiving unequivocal advice to stop using tobacco, each patient viewed a 9-minute videotape, received a self-help manual, and was briefly counseled by the dental hygienist. RESULTS. Long-term success was defined as no smokeless tobacco use at both 3- and 12-month follow-ups, with those lost to follow-up counted as smokeless tobacco users. The intervention increased the proportion of patients who quit by about one half (12.5% vs 18.4%, P < .05). CONCLUSIONS. These results demonstrate the efficacy of a brief dental office intervention for the general population of smokeless tobacco users.  相似文献   
10.
ABSTRACT: Given the increasing prevalence of schoolchildren's experience with crises and resulting loss through sudden or violent death, adoption of a school-based crisis prevention and response plan becomes crucial. This article reviews a model of regional, district, and school-based levels of response designed collaboratively by four school districts and consultants from Yale University. The team approach on which the model is based is examined through benefits it affords students, staff, parents, and the community. Obstacles that can impede full implementation of the model are identified, and strategies for overcoming logistical and systemic resistances are offered. This proactive design helps promote individual and organizational resiliency to traumatic events by promoting communication, collaboration, and service provision in an efficient and comprehensive manner.  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