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   2599079篇
  免费   191323篇
  国内免费   9053篇
耳鼻咽喉   34346篇
儿科学   85388篇
妇产科学   71700篇
基础医学   365196篇
口腔科学   69972篇
临床医学   236520篇
内科学   517076篇
皮肤病学   62643篇
神经病学   214292篇
特种医学   100760篇
外国民族医学   742篇
外科学   388448篇
综合类   54030篇
现状与发展   7篇
一般理论   969篇
预防医学   197197篇
眼科学   57058篇
药学   189936篇
  19篇
中国医学   6748篇
肿瘤学   146408篇
  2021年   20760篇
  2019年   21272篇
  2018年   29879篇
  2017年   23188篇
  2016年   26831篇
  2015年   30373篇
  2014年   41491篇
  2013年   61474篇
  2012年   81626篇
  2011年   86036篇
  2010年   52118篇
  2009年   50126篇
  2008年   80109篇
  2007年   84959篇
  2006年   86492篇
  2005年   82531篇
  2004年   79469篇
  2003年   76884篇
  2002年   74126篇
  2001年   128973篇
  2000年   131770篇
  1999年   110813篇
  1998年   31458篇
  1997年   28096篇
  1996年   28366篇
  1995年   27494篇
  1994年   25162篇
  1993年   23491篇
  1992年   85226篇
  1991年   81624篇
  1990年   78838篇
  1989年   76099篇
  1988年   69508篇
  1987年   68028篇
  1986年   63565篇
  1985年   60526篇
  1984年   44954篇
  1983年   37947篇
  1982年   22460篇
  1981年   19985篇
  1979年   38965篇
  1978年   27439篇
  1977年   23253篇
  1976年   21495篇
  1975年   22813篇
  1974年   26786篇
  1973年   25370篇
  1972年   23750篇
  1971年   21956篇
  1970年   20183篇
排序方式: 共有10000条查询结果,搜索用时 31 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