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   2754241篇
  免费   197922篇
  国内免费   7907篇
耳鼻咽喉   36593篇
儿科学   90167篇
妇产科学   75608篇
基础医学   388209篇
口腔科学   74048篇
临床医学   248545篇
内科学   551274篇
皮肤病学   67184篇
神经病学   229414篇
特种医学   104658篇
外国民族医学   810篇
外科学   408163篇
综合类   51092篇
现状与发展   5篇
一般理论   1015篇
预防医学   211871篇
眼科学   60036篇
药学   200453篇
  8篇
中国医学   5868篇
肿瘤学   155049篇
  2021年   23290篇
  2019年   24133篇
  2018年   35393篇
  2017年   26577篇
  2016年   30207篇
  2015年   33930篇
  2014年   45290篇
  2013年   67873篇
  2012年   93329篇
  2011年   97833篇
  2010年   57602篇
  2009年   54109篇
  2008年   90158篇
  2007年   95796篇
  2006年   96511篇
  2005年   92557篇
  2004年   88680篇
  2003年   85255篇
  2002年   81953篇
  2001年   131269篇
  2000年   134292篇
  1999年   113125篇
  1998年   31851篇
  1997年   28459篇
  1996年   28684篇
  1995年   27807篇
  1994年   25468篇
  1993年   23766篇
  1992年   86868篇
  1991年   83103篇
  1990年   80203篇
  1989年   77339篇
  1988年   70728篇
  1987年   69159篇
  1986年   64626篇
  1985年   61541篇
  1984年   45729篇
  1983年   38582篇
  1982年   22824篇
  1981年   20248篇
  1979年   39653篇
  1978年   27909篇
  1977年   23692篇
  1976年   21833篇
  1975年   23280篇
  1974年   27408篇
  1973年   26010篇
  1972年   24368篇
  1971年   22534篇
  1970年   20766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