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   2759161篇
  免费   190588篇
  国内免费   7570篇
耳鼻咽喉   35578篇
儿科学   91694篇
妇产科学   74741篇
基础医学   381999篇
口腔科学   71273篇
临床医学   246689篇
内科学   546781篇
皮肤病学   63240篇
神经病学   229170篇
特种医学   108713篇
外国民族医学   737篇
外科学   416302篇
综合类   52936篇
现状与发展   5篇
一般理论   979篇
预防医学   213085篇
眼科学   59417篇
药学   197384篇
  8篇
中国医学   5961篇
肿瘤学   160627篇
  2021年   20317篇
  2019年   20880篇
  2018年   49662篇
  2017年   38733篇
  2016年   45115篇
  2015年   30694篇
  2014年   41510篇
  2013年   61484篇
  2012年   87082篇
  2011年   104415篇
  2010年   68375篇
  2009年   60140篇
  2008年   98060篇
  2007年   105635篇
  2006年   86504篇
  2005年   84555篇
  2004年   82924篇
  2003年   81490篇
  2002年   76735篇
  2001年   128803篇
  2000年   131939篇
  1999年   110745篇
  1998年   31526篇
  1997年   28243篇
  1996年   28384篇
  1995年   27555篇
  1994年   25260篇
  1993年   23576篇
  1992年   85289篇
  1991年   81749篇
  1990年   78966篇
  1989年   76187篇
  1988年   69580篇
  1987年   68103篇
  1986年   63626篇
  1985年   60614篇
  1984年   45013篇
  1983年   38011篇
  1982年   22560篇
  1981年   20003篇
  1979年   39058篇
  1978年   27510篇
  1977年   23279篇
  1976年   21560篇
  1975年   22833篇
  1974年   26832篇
  1973年   25387篇
  1972年   23757篇
  1971年   21961篇
  1970年   20220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