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   3236篇
  免费   190篇
  国内免费   56篇
耳鼻咽喉   110篇
儿科学   15篇
妇产科学   45篇
基础医学   654篇
口腔科学   58篇
临床医学   302篇
内科学   803篇
皮肤病学   82篇
神经病学   235篇
特种医学   121篇
外科学   275篇
综合类   13篇
现状与发展   1篇
预防医学   117篇
眼科学   38篇
药学   314篇
中国医学   54篇
肿瘤学   245篇
  2023年   8篇
  2022年   75篇
  2021年   119篇
  2020年   54篇
  2019年   79篇
  2018年   110篇
  2017年   67篇
  2016年   99篇
  2015年   136篇
  2014年   146篇
  2013年   192篇
  2012年   307篇
  2011年   300篇
  2010年   199篇
  2009年   150篇
  2008年   232篇
  2007年   189篇
  2006年   169篇
  2005年   156篇
  2004年   134篇
  2003年   119篇
  2002年   100篇
  2001年   95篇
  2000年   67篇
  1999年   47篇
  1998年   17篇
  1997年   12篇
  1996年   7篇
  1995年   4篇
  1994年   9篇
  1993年   3篇
  1992年   9篇
  1991年   11篇
  1990年   12篇
  1989年   5篇
  1988年   8篇
  1987年   5篇
  1986年   4篇
  1985年   4篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1979年   2篇
  1977年   1篇
  1976年   1篇
  1973年   7篇
  1972年   2篇
  1969年   3篇
  1968年   4篇
排序方式: 共有3482条查询结果,搜索用时 15 毫秒
31.
This study explored the psychosocial differences in the addictive tendency toward social networking sites (SNSs) between male and female Korean college students. A convenience sample of 253 college students, 90 males and 163 females, from two universities in G City, South Korea, was recruited between October 17 and November 12, 2015. Data were analyzed using the Mann-Whitney test, analysis of variance, Pearson’s correlation, and simultaneous quantile regression. Female students showed a significantly higher tendency for SNS addiction than males did. Age and social support had significant effects on the tendency for SNS addiction in males; daily frequency of logging in to SNSs, subjective happiness, and depression had significant effects on the same in female respondents who fell above the 50th percentile on SNS addiction. Our data provide evidence of a heterogeneous effect of SNS addictive tendency determinants among college students, which is considered to be due to the interpersonal orientation of women and their vulnerability to depression.  相似文献   
32.
Structural reorganization in white matter (WM) after stroke is a potential contributor to substitute or to newly establish the functional field on the injured brain in nature. Diffusion tensor imaging (DTI) is an imaging modality that can be used to evaluate damage and recovery within the brain. This method of imaging allows for in vivo assessment of the restricted movements of water molecules in WM and provides a detailed look at structural connectivity in the brain. For longitudinal DTI studies after a stroke, the conventional region of interest method and voxel‐based analysis are highly dependent on the user‐hypothesis and parameter settings for implementation. In contrast, tract‐based spatial statistics (TBSS) allows for reliable voxel‐wise analysis via the projection of diffusion‐derived parameters onto an alignment‐invariant WM skeleton. In this study, spatiotemporal WM changes were examined with DTI‐derived parameters (fractional anisotropy, FA; mean diffusivity, MD; axial diffusivity, DA; radial diffusivity, RD) using TBSS 2 h to 6 weeks after experimental focal ischemic stroke in rats (N = 6). FA values remained unchanged 2–4 h after the stroke, followed by a continuous decrease in the ipsilesional hemisphere from 24 h to 2 weeks post‐stroke and gradual recovery from the ipsilesional corpus callosum to the external capsule until 6 weeks post‐stroke. In particular, the fibers in these areas were extended toward the striatum of the ischemic boundary region at 6 weeks on tractography. The alterations of the other parameters in the ipsilesional hemisphere showed patterns of a decrease at the early stage, a subsequent pseudo‐normalization of MD and DA, a rapid reduction of RD, and a progressive increase in MD, DA and RD with a decreased extent in the injured area at later stages. The findings of this study may reflect the ongoing processes on tissue damage and spontaneous recovery after stroke.  相似文献   
33.
34.
35.
Under Korean field conditions, coinfection with porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) is most commonly observed in porcine respiratory disease complex (PRDC). Despite the wide use of PCV2 vaccination, PRDC remains a serious respiratory problem. Thus, the objective of this study was to determine and compare the efficacy of 4 one-dose PCV2 vaccines on 3-week-old pigs with an experimental PCV2-PRRSV challenge at 17 weeks postvaccination. Regardless of which commercial PCV2 vaccine was used, the vaccination of piglets at 3 weeks of age was efficacious against cochallenge of PCV2 and PRRSV, on the basis of growth performance and PCV2-associated lesions. However, the inactivated chimeric PCV1-2 and the PCV2 vaccines induced higher PCV2-specific neutralizing antibody (NA) titers and PCV2-specific gamma interferon-secreting cells and lower PCV2 viremia levels than the two PCV2 subunit vaccines. The vaccination of piglets against PCV2 at 3 weeks of age was effective in reducing PCV2 viremia and PCV2-associated lesions during the finishing period, which is an age at which pigs are frequently affected by PRDC caused by coinfection with PCV2 and PRRSV under Korean field conditions.  相似文献   
36.
Plate‐like osteoma cutis (PLOC) is a dermatological disorder characterized by superficial ossification and rarely occurs without any underlying tissue abnormalities or pre‐existing calcification. The hereditary form of PLOC is mainly due to inactivating mutation in the GNAS gene. Inactivating mutation of the GNAS gene is associated with several diseases, which commonly manifest heterotopic ossification and hormonal resistance; however, the development of malignant neoplasm has never been reported. Herein, we report a case of a patient with a novel nonsense mutation in the GNAS gene, who presented with concurrent PLOC and medulloblastoma.  相似文献   
37.
38.
39.
40.
This study uses data from the National Latino and Asian American Study to investigate correlates of mental health service use among Asian Americans with mental health needs. Our study contributes to the extant literature by: (1) differentiating between mental health service use types; and (2) examining a broader swatch of Asian Americans with mental health needs, ranging from mild to severe cases. Multinomial logistic regression analyses revealed heterogeneity in service use patterns by ethnicity, age, marital status, English proficiency, and generation status. Unmet mental health needs continue to be a problem despite treatments that could improve the quality of life of Asian Americans. Our study provides a more nuanced understanding of mental health service utilization patterns in this understudied population.  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