首页 | 官方网站   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   125308篇
  免费   8153篇
  国内免费   991篇
医药卫生   134452篇
  2023年   709篇
  2022年   668篇
  2021年   2957篇
  2020年   1900篇
  2019年   2652篇
  2018年   3217篇
  2017年   2471篇
  2016年   2677篇
  2015年   3001篇
  2014年   3896篇
  2013年   5394篇
  2012年   7561篇
  2011年   7636篇
  2010年   4720篇
  2009年   4197篇
  2008年   6520篇
  2007年   6797篇
  2006年   6386篇
  2005年   5946篇
  2004年   6114篇
  2003年   5818篇
  2002年   5648篇
  2001年   3928篇
  2000年   3848篇
  1999年   3159篇
  1998年   1348篇
  1997年   1065篇
  1996年   936篇
  1995年   892篇
  1994年   785篇
  1993年   755篇
  1992年   1856篇
  1991年   1829篇
  1990年   1552篇
  1989年   1475篇
  1988年   1379篇
  1987年   1228篇
  1986年   1196篇
  1985年   1081篇
  1984年   795篇
  1983年   720篇
  1982年   476篇
  1981年   402篇
  1979年   598篇
  1978年   441篇
  1975年   439篇
  1974年   491篇
  1973年   482篇
  1972年   442篇
  1971年   406篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
1.
2.
Whereas there is evidence that interpersonal communication, or conversation, influences predictors of alcohol consumption, the role of involvement in conversation effects remains unclear. This study explored how three aspects of involvement (topical relevance, or how relevant the topic of alcohol is; conversational relevance, or how relevant a conversation about alcohol is; and conversational effort, or how much effort people put into such a conversation), influence conversation effects. After assessing topical relevance, 46 same-sex dyads were requested to talk about the negative consequences of heavy drinking. Within each dyad, one participant was asked to take on an active talking role and the other participant a passive listening role. Next, conversational relevance, effort, and predictors of heavy drinking were measured. Results showed that participants who drank more alcohol found the topic of heavy drinking more relevant. This topical relevance increased conversational relevance and conversational effort. Conversational effort further increased when a talking role was assigned. Furthermore, participants who put more effort in the conversation and found it more relevant had more positive norms, identified more strongly with alcohol, and had higher intentions to drink. These findings suggest that more involvement in an alcohol-related conversation does not always lead to desirable outcomes.  相似文献   
3.
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   

4.
5.
6.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
7.
8.
9.
10.
ABSTRACT

Purpose

To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR).  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-23

京公网安备 11010802026262号