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   2721744篇
  免费   216365篇
  国内免费   9572篇
耳鼻咽喉   38667篇
儿科学   90180篇
妇产科学   73792篇
基础医学   368023篇
口腔科学   71306篇
临床医学   258599篇
内科学   556898篇
皮肤病学   69211篇
神经病学   226918篇
特种医学   105553篇
外国民族医学   738篇
外科学   422652篇
综合类   51000篇
现状与发展   76篇
一般理论   989篇
预防医学   203179篇
眼科学   60091篇
药学   189914篇
  8篇
中国医学   5360篇
肿瘤学   154527篇
  2021年   22545篇
  2019年   22461篇
  2018年   35503篇
  2017年   28681篇
  2016年   33105篇
  2015年   36420篇
  2014年   53700篇
  2013年   74055篇
  2012年   85672篇
  2011年   90009篇
  2010年   60167篇
  2009年   61480篇
  2008年   84741篇
  2007年   88163篇
  2006年   91926篇
  2005年   85824篇
  2004年   82158篇
  2003年   78552篇
  2002年   75910篇
  2001年   131807篇
  2000年   134036篇
  1999年   113363篇
  1998年   34478篇
  1997年   30911篇
  1996年   31097篇
  1995年   30089篇
  1994年   26745篇
  1993年   24756篇
  1992年   86389篇
  1991年   82853篇
  1990年   79811篇
  1989年   77143篇
  1988年   70417篇
  1987年   68828篇
  1986年   64372篇
  1985年   61199篇
  1984年   45518篇
  1983年   38505篇
  1982年   23027篇
  1981年   20452篇
  1979年   39365篇
  1978年   27823篇
  1977年   23677篇
  1976年   21787篇
  1975年   23121篇
  1974年   27091篇
  1973年   25651篇
  1972年   24072篇
  1971年   22185篇
  1970年   20437篇
排序方式: 共有10000条查询结果,搜索用时 31 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