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   2827212篇
  免费   222565篇
  国内免费   9777篇
耳鼻咽喉   40187篇
儿科学   92980篇
妇产科学   75897篇
基础医学   382918篇
口腔科学   73824篇
临床医学   268621篇
内科学   577431篇
皮肤病学   70814篇
神经病学   238105篇
特种医学   109262篇
外国民族医学   747篇
外科学   437405篇
综合类   52287篇
现状与发展   79篇
一般理论   1118篇
预防医学   211014篇
眼科学   63094篇
药学   197244篇
  8篇
中国医学   5500篇
肿瘤学   161019篇
  2021年   24209篇
  2019年   24106篇
  2018年   37351篇
  2017年   29997篇
  2016年   34602篇
  2015年   38276篇
  2014年   56422篇
  2013年   78677篇
  2012年   92498篇
  2011年   97473篇
  2010年   64221篇
  2009年   65025篇
  2008年   91970篇
  2007年   96017篇
  2006年   99317篇
  2005年   93679篇
  2004年   89716篇
  2003年   85808篇
  2002年   82817篇
  2001年   132544篇
  2000年   134513篇
  1999年   114141篇
  1998年   35832篇
  1997年   32041篇
  1996年   31985篇
  1995年   30880篇
  1994年   27536篇
  1993年   25562篇
  1992年   86875篇
  1991年   83284篇
  1990年   80166篇
  1989年   77544篇
  1988年   70801篇
  1987年   69122篇
  1986年   64769篇
  1985年   61654篇
  1984年   46217篇
  1983年   39179篇
  1982年   24019篇
  1981年   21421篇
  1979年   39807篇
  1978年   28350篇
  1977年   24139篇
  1976年   22210篇
  1975年   23454篇
  1974年   27411篇
  1973年   25916篇
  1972年   24276篇
  1971年   22325篇
  1970年   20552篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
7.
8.
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   
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