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   2931427篇
  免费   210804篇
  国内免费   8397篇
耳鼻咽喉   39707篇
儿科学   96001篇
妇产科学   80410篇
基础医学   421371篇
口腔科学   80516篇
临床医学   265485篇
内科学   573472篇
皮肤病学   71310篇
神经病学   237635篇
特种医学   113077篇
外国民族医学   779篇
外科学   438165篇
综合类   56031篇
现状与发展   6篇
一般理论   1068篇
预防医学   222523篇
眼科学   65860篇
药学   217005篇
  8篇
中国医学   6463篇
肿瘤学   163736篇
  2021年   23529篇
  2019年   23595篇
  2018年   33277篇
  2017年   25507篇
  2016年   29941篇
  2015年   34173篇
  2014年   46528篇
  2013年   68945篇
  2012年   92055篇
  2011年   96969篇
  2010年   58328篇
  2009年   55587篇
  2008年   89722篇
  2007年   95012篇
  2006年   96395篇
  2005年   92096篇
  2004年   88596篇
  2003年   85122篇
  2002年   82271篇
  2001年   140990篇
  2000年   144642篇
  1999年   121495篇
  1998年   34693篇
  1997年   30668篇
  1996年   31080篇
  1995年   30037篇
  1994年   27558篇
  1993年   25827篇
  1992年   94043篇
  1991年   91120篇
  1990年   88504篇
  1989年   85536篇
  1988年   78246篇
  1987年   76886篇
  1986年   71789篇
  1985年   68658篇
  1984年   50985篇
  1983年   43111篇
  1982年   25278篇
  1979年   45257篇
  1978年   31988篇
  1977年   27190篇
  1976年   25200篇
  1975年   27216篇
  1974年   32257篇
  1973年   30474篇
  1972年   28792篇
  1971年   26810篇
  1970年   24763篇
  1969年   23739篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
3.

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017–6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21lo/neg cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21lo/neg B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21lo/neg cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21lo/neg B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.

  相似文献   
4.
5.
6.
Intratumor heterogeneity is a main cause of the dismal prognosis of glioblastoma (GBM). Yet, there remains a lack of a uniform assessment of the degree of heterogeneity. With a multiscale approach, we addressed the hypothesis that intratumor heterogeneity exists on different levels comprising traditional regional analyses, but also innovative methods including computer-assisted analysis of tumor morphology combined with epigenomic data. With this aim, 157 biopsies of 37 patients with therapy-naive IDH-wildtype GBM were analyzed regarding the intratumor variance of protein expression of glial marker GFAP, microglia marker Iba1 and proliferation marker Mib1. Hematoxylin and eosin stained slides were evaluated for tumor vascularization. For the estimation of pixel intensity and nuclear profiling, automated analysis was used. Additionally, DNA methylation profiling was conducted separately for the single biopsies. Scoring systems were established to integrate several parameters into one score for the four examined modalities of heterogeneity (regional, cellular, pixel-level and epigenomic). As a result, we could show that heterogeneity was detected in all four modalities. Furthermore, for the regional, cellular and epigenomic level, we confirmed the results of earlier studies stating that a higher degree of heterogeneity is associated with poorer overall survival. To integrate all modalities into one score, we designed a predictor of longer survival, which showed a highly significant separation regarding the OS. In conclusion, multiscale intratumor heterogeneity exists in glioblastoma and its degree has an impact on overall survival. In future studies, the implementation of a broadly feasible heterogeneity index should be considered.  相似文献   
7.
Social Psychiatry and Psychiatric Epidemiology - The negative effect of catastrophic financial loss on suicide risk is widely perceived but hardly studied in-depth because of various difficulties...  相似文献   
8.
9.
10.
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