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   2668654篇
  免费   193856篇
  国内免费   7605篇
耳鼻咽喉   35880篇
儿科学   88472篇
妇产科学   73929篇
基础医学   376885篇
口腔科学   72981篇
临床医学   241514篇
内科学   528576篇
皮肤病学   65055篇
神经病学   222208篇
特种医学   103753篇
外国民族医学   736篇
外科学   399730篇
综合类   50699篇
现状与发展   5篇
一般理论   998篇
预防医学   200418篇
眼科学   58799篇
药学   194646篇
  8篇
中国医学   5396篇
肿瘤学   149427篇
  2021年   20263篇
  2019年   21649篇
  2018年   31421篇
  2017年   24418篇
  2016年   28503篇
  2015年   31381篇
  2014年   42538篇
  2013年   64310篇
  2012年   85197篇
  2011年   90168篇
  2010年   54161篇
  2009年   51204篇
  2008年   84752篇
  2007年   89978篇
  2006年   91365篇
  2005年   87547篇
  2004年   84230篇
  2003年   81583篇
  2002年   78730篇
  2001年   130985篇
  2000年   134664篇
  1999年   112454篇
  1998年   32163篇
  1997年   28574篇
  1996年   26996篇
  1995年   27715篇
  1994年   25410篇
  1993年   23758篇
  1992年   85530篇
  1991年   81939篇
  1990年   79113篇
  1989年   76403篇
  1988年   69715篇
  1987年   68327篇
  1986年   63817篇
  1985年   60971篇
  1984年   45368篇
  1983年   38244篇
  1982年   22820篇
  1981年   20311篇
  1979年   39250篇
  1978年   27717篇
  1977年   23529篇
  1976年   21750篇
  1975年   23096篇
  1974年   27045篇
  1973年   25610篇
  1972年   23938篇
  1971年   22165篇
  1970年   20370篇
排序方式: 共有10000条查询结果,搜索用时 562 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