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   2897752篇
  免费   201416篇
  国内免费   7938篇
耳鼻咽喉   37170篇
儿科学   95204篇
妇产科学   77518篇
基础医学   400004篇
口腔科学   74597篇
临床医学   260529篇
内科学   574988篇
皮肤病学   65013篇
神经病学   242896篇
特种医学   113027篇
外国民族医学   740篇
外科学   437778篇
综合类   55477篇
现状与发展   7篇
一般理论   1234篇
预防医学   226476篇
眼科学   62492篇
药学   207709篇
  9篇
中国医学   6215篇
肿瘤学   168023篇
  2021年   22327篇
  2019年   22980篇
  2018年   51823篇
  2017年   40478篇
  2016年   46897篇
  2015年   33169篇
  2014年   45381篇
  2013年   67617篇
  2012年   95609篇
  2011年   113560篇
  2010年   73418篇
  2009年   65008篇
  2008年   107016篇
  2007年   115082篇
  2006年   96102篇
  2005年   94618篇
  2004年   92800篇
  2003年   90639篇
  2002年   85651篇
  2001年   130110篇
  2000年   132922篇
  1999年   112180篇
  1998年   33490篇
  1997年   29960篇
  1996年   29959篇
  1995年   28911篇
  1994年   26506篇
  1993年   24716篇
  1992年   86095篇
  1991年   82507篇
  1990年   79644篇
  1989年   76812篇
  1988年   70212篇
  1987年   68703篇
  1986年   64273篇
  1985年   61298篇
  1984年   46041篇
  1983年   38998篇
  1982年   23851篇
  1981年   21164篇
  1979年   39644篇
  1978年   28184篇
  1977年   23983篇
  1976年   22166篇
  1975年   23373篇
  1974年   27334篇
  1973年   25853篇
  1972年   24080篇
  1971年   22236篇
  1970年   20483篇
排序方式: 共有10000条查询结果,搜索用时 15 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.

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   
3.
4.
5.
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   
6.
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