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   2699636篇
  免费   215088篇
  国内免费   9513篇
耳鼻咽喉   38468篇
儿科学   89645篇
妇产科学   73465篇
基础医学   365498篇
口腔科学   70929篇
临床医学   256219篇
内科学   551433篇
皮肤病学   68958篇
神经病学   225068篇
特种医学   105042篇
外国民族医学   736篇
外科学   419819篇
综合类   50578篇
现状与发展   76篇
一般理论   985篇
预防医学   200663篇
眼科学   59488篇
药学   188652篇
  8篇
中国医学   5338篇
肿瘤学   153169篇
  2021年   22191篇
  2019年   22166篇
  2018年   35191篇
  2017年   28461篇
  2016年   32896篇
  2015年   36133篇
  2014年   53277篇
  2013年   73394篇
  2012年   84666篇
  2011年   88973篇
  2010年   59595篇
  2009年   60986篇
  2008年   83781篇
  2007年   87147篇
  2006年   90922篇
  2005年   84814篇
  2004年   81223篇
  2003年   77682篇
  2002年   75051篇
  2001年   131627篇
  2000年   133858篇
  1999年   113192篇
  1998年   34343篇
  1997年   30803篇
  1996年   30998篇
  1995年   30012篇
  1994年   26664篇
  1993年   24676篇
  1992年   86154篇
  1991年   82740篇
  1990年   79639篇
  1989年   76999篇
  1988年   70273篇
  1987年   68681篇
  1986年   64265篇
  1985年   61058篇
  1984年   45343篇
  1983年   38289篇
  1982年   22790篇
  1981年   20231篇
  1979年   39165篇
  1978年   27653篇
  1977年   23504篇
  1976年   21628篇
  1975年   22996篇
  1974年   26948篇
  1973年   25531篇
  1972年   23960篇
  1971年   22118篇
  1970年   20383篇
排序方式: 共有10000条查询结果,搜索用时 250 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