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   314190篇
  免费   28613篇
  国内免费   6487篇
耳鼻咽喉   4036篇
儿科学   6461篇
妇产科学   5009篇
基础医学   21671篇
口腔科学   12216篇
临床医学   34033篇
内科学   32601篇
皮肤病学   4075篇
神经病学   16810篇
特种医学   8236篇
外国民族医学   34篇
外科学   31342篇
综合类   49359篇
现状与发展   18篇
一般理论   48篇
预防医学   39411篇
眼科学   3728篇
药学   29599篇
  541篇
中国医学   34308篇
肿瘤学   15754篇
  2024年   1282篇
  2023年   6408篇
  2022年   11291篇
  2021年   14963篇
  2020年   15186篇
  2019年   15571篇
  2018年   13989篇
  2017年   12809篇
  2016年   12066篇
  2015年   11238篇
  2014年   21338篇
  2013年   24294篇
  2012年   19231篇
  2011年   20593篇
  2010年   16729篇
  2009年   14617篇
  2008年   13536篇
  2007年   13719篇
  2006年   11960篇
  2005年   9985篇
  2004年   8315篇
  2003年   7383篇
  2002年   5836篇
  2001年   4886篇
  2000年   4258篇
  1999年   3384篇
  1998年   2790篇
  1997年   2503篇
  1996年   2055篇
  1995年   1904篇
  1994年   1702篇
  1993年   1496篇
  1992年   1316篇
  1991年   1176篇
  1990年   1015篇
  1989年   978篇
  1988年   922篇
  1987年   813篇
  1986年   749篇
  1985年   2049篇
  1984年   2261篇
  1983年   1430篇
  1982年   1885篇
  1981年   1328篇
  1980年   1145篇
  1979年   1017篇
  1978年   801篇
  1977年   610篇
  1976年   749篇
  1975年   512篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
72.
73.

Background

Purulent bacterial pericarditis is a rare and potentially fatal disease. The course may be fulminant, and the presentation may pose a diagnostic challenge.

Case report

An otherwise healthy 75-year-old male was brought to the emergency department in a state of general deterioration, confusion, and shock. Bedside ultrasound showed a significant pericardial effusion. His condition quickly deteriorated and the resuscitation included emergent bedside pericardiocentesis. The drainage was purulent and later cultures grew out Streptococcus pneumoniae.

Why should an emergency physician be aware of this?

Purulent pericarditis is extremely rare but should be considered in the patient with a fulminant infectious process (particularly pneumonia) and signs of pericardial effusion. Treatment should include appropriate antibiotics and early drainage.  相似文献   
74.
BackgroundSkin cancer is a highly prevalent condition with a multifactorial etiology resulting from genetic alterations, environmental and lifestyle factors. In Brazil, among all malignant tumors, skin cancers have the highest incidences.ObjectiveTo retrospectively evaluate the incidence, prevalence and profile of basal cell carcinoma, squamous cell carcinoma and cutaneous melanoma in Campos dos Goytacazes and region.Methods:In total, 2,207 histopathological reports of a local reference hospital were analyzed between January 2013 and December 2015, of which 306 corresponded to the neoplasms studied.Results:Of the 306 reports evaluated, 232 basal cell carcinomas (75.9%), 55 squamous cell carcinomas (18%) and 19 cutaneous melanomas (6.5%) were identified. The face was the most involved anatomical site (58.8%) and women (51%) were the most affected gender. The temporal analysis revealed a decrease in the overall incidence of 3.4% from 2013 to 2014 and 5.4% from 2014 to 2015. There was a 10.1% increase in basal cell carcinomas and 38% in melanomas in this period; however, there was a decrease in the number of squamous cell carcinomas of 14.8% during the studied years.Study limitations:Some samples of cutaneous fragments had no identification of the anatomical site of origin.Conclusion:Research that generates statistical data on cutaneous tumors produces epidemiological tools useful in the identification of risk groups and allows the adoption of more targeted and efficient future prevention measures.  相似文献   
75.
Problem: Although efficacy studies of opioid maintenance treatment (OMT) have shown evidence of treatment benefits, there is still need for studies on its effectiveness in natural clinical processes. This study investigates the development in health, substance use and social conditions of those who applied for OMT, including those denied access or discharged.

Method: First, persons assessed for admittance in 2005–2011 (n?=?127) were categorized into four trajectory groups based on whether they were admitted or denied (n?=?19), discharged (n?=?31), readmitted (n?=?21) or had been undergoing OMT without interruption (n?=?56). Second, 99 of these, the analytical sample, were interviewed at follow-up using (a) the Addiction Severity Index (ASI) for seven problem-areas and housing, and (b) self-rated change in 11 problem areas. The ASI was compared to baseline interviews after 55 months (mean). Third, outcomes within groups was studied in relation to alternative interventions.

Results: Within the analytical sample, those denied OMT showed no improvements at group level, those discharged had some improvements, more if readmitted than if not and those with uninterrupted OMT showed the most comprehensive improvements. Those outside OMT, denied and discharged, had considerable mortality risks related to ongoing drug use, especially in lack of well-planned alternative interventions.

Conclusion: Improvements strongly relate to access to OMT. This study underscores that access to OMT improves the situation in all areas investigated and decreases the risk for drug-related death. It underscores the importance of two major risk situations, i.e. being denied OMT and being discharged.  相似文献   

76.
77.
78.
目的探讨中西医结合护理改善老年高血压患者心理状态及生活质量的效果。方法在医院2018年1月—2018年6月就诊的老年高血压患者中选出60例,按照随机数字法的原则,分成研究组(n=30)和参考组(n=30)。参考组采用单一西医护理,研究组在此之外联合中医护理,比较两组患者的临床疗效。结果入院时研究组与参考组SAS、SDS、SF-6评分差异不显著(P>0.05),护理后1月、3月与参考组相比,研究组SAS、SDS评分显著降低(P<0.05),SF-6评分显著升高(P<0.05);研究组患者对中西结合护理满意度为96.67%,参考组患者对西医护理满意度为73.33%,研究组满意度较参考组高,差异显著(P<0.05)。结论中西医结合护理能够有效改善老年高血压患者的心理状态,提高生活质量。  相似文献   
79.
David Marr's three-level method for completely understanding a cognitive system and the importance he attaches to the computational level are so familiar as to scarcely need repeating. Fewer seem to recognize that Marr defends his famous method by criticizing the “reductionistic approach.” This sets up a more interesting relationship between Marr and reductionism than is usually acknowledged. I argue that Marr was correct in his criticism of the reductionists of his time—they were only describing (cellular activity), not explaining (cognitive functions). But a careful metascientific account of reductionistic neuroscience over the past two decades reveals that Marr's criticisms no longer have force. Contemporary neuroscience now explains cognition directly, although in a fashion—causal-mechanistically—quite different than Marr recommended. So while Marr was correct to reject the reductionism of his day and offer an alternative method for genuinely explaining cognition, contemporary cognitive scientists now owe us a new defense of Marr's famous method and the advantages of its explanations over the type now pursued successfully in current reductionist neuroscience. There are familiar reasons for thinking that this debt will not be paid easily.  相似文献   
80.
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