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   2602617篇
  免费   190566篇
  国内免费   7637篇
耳鼻咽喉   34622篇
儿科学   85728篇
妇产科学   72124篇
基础医学   366373篇
口腔科学   71161篇
临床医学   236365篇
内科学   518764篇
皮肤病学   62967篇
神经病学   215236篇
特种医学   100308篇
外国民族医学   737篇
外科学   388340篇
综合类   50491篇
现状与发展   5篇
一般理论   979篇
预防医学   198347篇
眼科学   57002篇
药学   189558篇
  8篇
中国医学   5451篇
肿瘤学   146254篇
  2021年   20885篇
  2019年   21404篇
  2018年   30156篇
  2017年   23228篇
  2016年   26864篇
  2015年   30232篇
  2014年   41383篇
  2013年   61725篇
  2012年   82003篇
  2011年   86431篇
  2010年   51987篇
  2009年   50021篇
  2008年   80456篇
  2007年   85200篇
  2006年   86809篇
  2005年   82854篇
  2004年   79703篇
  2003年   76976篇
  2002年   74191篇
  2001年   128595篇
  2000年   131500篇
  1999年   110638篇
  1998年   31410篇
  1997年   28036篇
  1996年   28328篇
  1995年   27469篇
  1994年   25145篇
  1993年   23485篇
  1992年   85271篇
  1991年   81674篇
  1990年   78893篇
  1989年   76145篇
  1988年   69543篇
  1987年   68065篇
  1986年   63616篇
  1985年   60571篇
  1984年   45003篇
  1983年   37994篇
  1982年   22516篇
  1981年   20022篇
  1979年   39019篇
  1978年   27476篇
  1977年   23295篇
  1976年   21527篇
  1975年   22853篇
  1974年   26825篇
  1973年   25400篇
  1972年   23772篇
  1971年   21963篇
  1970年   20176篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
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   
2.
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.
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