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   2604548篇
  免费   191050篇
  国内免费   7606篇
耳鼻咽喉   34457篇
儿科学   85776篇
妇产科学   72004篇
基础医学   366205篇
口腔科学   70058篇
临床医学   236631篇
内科学   519691篇
皮肤病学   62904篇
神经病学   215614篇
特种医学   100720篇
外国民族医学   737篇
外科学   389707篇
综合类   50760篇
现状与发展   5篇
一般理论   1052篇
预防医学   197940篇
眼科学   57509篇
药学   189471篇
  8篇
中国医学   5361篇
肿瘤学   146594篇
  2021年   20284篇
  2019年   20943篇
  2018年   29688篇
  2017年   22920篇
  2016年   26590篇
  2015年   29906篇
  2014年   41021篇
  2013年   61347篇
  2012年   81572篇
  2011年   85891篇
  2010年   51820篇
  2009年   49854篇
  2008年   80357篇
  2007年   85214篇
  2006年   86944篇
  2005年   83127篇
  2004年   80085篇
  2003年   77365篇
  2002年   74596篇
  2001年   128780篇
  2000年   131615篇
  1999年   110816篇
  1998年   31557篇
  1997年   28165篇
  1996年   28453篇
  1995年   27608篇
  1994年   25251篇
  1993年   23606篇
  1992年   85398篇
  1991年   81793篇
  1990年   78982篇
  1989年   76267篇
  1988年   69655篇
  1987年   68180篇
  1986年   63715篇
  1985年   60723篇
  1984年   45144篇
  1983年   38129篇
  1982年   22661篇
  1981年   20182篇
  1979年   39141篇
  1978年   27626篇
  1977年   23410篇
  1976年   21610篇
  1975年   22941篇
  1974年   26937篇
  1973年   25493篇
  1972年   23851篇
  1971年   22055篇
  1970年   20244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.
Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.  相似文献   
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