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   1305313篇
  免费   101588篇
  国内免费   2128篇
耳鼻咽喉   18719篇
儿科学   45043篇
妇产科学   35738篇
基础医学   186348篇
口腔科学   35323篇
临床医学   113646篇
内科学   264557篇
皮肤病学   28935篇
神经病学   102848篇
特种医学   51658篇
外国民族医学   660篇
外科学   198737篇
综合类   27161篇
现状与发展   1篇
一般理论   395篇
预防医学   99000篇
眼科学   28383篇
药学   97031篇
  2篇
中国医学   2594篇
肿瘤学   72250篇
  2019年   10217篇
  2018年   14476篇
  2017年   10840篇
  2016年   11735篇
  2015年   13431篇
  2014年   18562篇
  2013年   27948篇
  2012年   38641篇
  2011年   40833篇
  2010年   24179篇
  2009年   22962篇
  2008年   38537篇
  2007年   41095篇
  2006年   41114篇
  2005年   39846篇
  2004年   38786篇
  2003年   37465篇
  2002年   36683篇
  2001年   64090篇
  2000年   66545篇
  1999年   56495篇
  1998年   15252篇
  1997年   13869篇
  1996年   14269篇
  1995年   13512篇
  1994年   12829篇
  1993年   11835篇
  1992年   44596篇
  1991年   43494篇
  1990年   42239篇
  1989年   40133篇
  1988年   36913篇
  1987年   36249篇
  1986年   33631篇
  1985年   32290篇
  1984年   24148篇
  1983年   20280篇
  1982年   11737篇
  1981年   10700篇
  1979年   21346篇
  1978年   14829篇
  1977年   12534篇
  1976年   11699篇
  1975年   12631篇
  1974年   14664篇
  1973年   14122篇
  1972年   12949篇
  1971年   11730篇
  1970年   11050篇
  1969年   10025篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Purpose: To use polymerase chain reaction (PCR) and Goldmann-Witmer coefficient (GWC) calculation to diagnose infectious uveitis.

Methods: Prospective cross-sectional study.

Results: Twenty-seven of 106 patients had positive PCR and/or GWC results on aqueous humor (AH) sampling and 15 of 27 (55.6%) were HIV-positive. Patients with non-anterior uveitis (NAU) were more likely to be HIV+ (p = 0.005). More than 1 possible pathogen was identified in 9 of 27 patients of whom 7 were HIV+. The final clinical diagnosis was discordant with AH findings in 9 of 27 cases. A positive EBV PCR result was associated with a discordant diagnosis (p = 0.001). All cases of herpetic anterior uveitis (42.9% HIV+) tested PCR-/GWC+ while all cases of herpetic NAU tested PCR+/GWC- (83.3% HIV+). All rubella virus cases were PCR+/GWC+.

Conclusion: PCR is useful to diagnose herpetic NAU in HIV+ patients while GWC is useful to diagnose herpetic anterior uveitis.  相似文献   

23.
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2.  相似文献   
24.
25.
26.

Background and objectives

A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.

Case report

A 41 year‐old woman suffered a car accident. At the emergency department, no abnormalities were found in ECG or chest X‐ray. Abdominal ultrasound revealed the presence of abdominal free liquid and the patient was submitted to urgent exploratory laparotomy. Nevertheless, she persisted suffering arterial hypotension and metabolic acidosis. Looking for the reason of her hemodynamic instability, intraoperative transthoracic echocardiography was performed, finding out the presence of pericardial effusion. Once the cardiac surgeon extracted pericardial clots, patient's situation improved clinically and analytically.

Conclusion

Every anesthesiologist should be able to use the intraoperative echocardiography as an effective tool in order to establish the appropriate measures to promote the survival of patients suffering severe trauma.  相似文献   
27.
28.
29.
30.
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