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   3292610篇
  免费   228231篇
  国内免费   8384篇
耳鼻咽喉   44115篇
儿科学   105926篇
妇产科学   88602篇
基础医学   457546篇
口腔科学   89729篇
临床医学   295463篇
内科学   643840篇
皮肤病学   74315篇
神经病学   270265篇
特种医学   129106篇
外国民族医学   800篇
外科学   502916篇
综合类   65371篇
现状与发展   5篇
一般理论   1146篇
预防医学   250837篇
眼科学   73511篇
药学   240178篇
  10篇
中国医学   7171篇
肿瘤学   188373篇
  2019年   24118篇
  2018年   53665篇
  2017年   41731篇
  2016年   48520篇
  2015年   35249篇
  2014年   47895篇
  2013年   71207篇
  2012年   99822篇
  2011年   117696篇
  2010年   76053篇
  2009年   67637篇
  2008年   111010篇
  2007年   119254篇
  2006年   101209篇
  2005年   98926篇
  2004年   96792篇
  2003年   94502篇
  2002年   89822篇
  2001年   155940篇
  2000年   160151篇
  1999年   134857篇
  1998年   37770篇
  1997年   33443篇
  1996年   33532篇
  1995年   32418篇
  1994年   29778篇
  1993年   27851篇
  1992年   104562篇
  1991年   100519篇
  1990年   97508篇
  1989年   94147篇
  1988年   86223篇
  1987年   84503篇
  1986年   79192篇
  1985年   75638篇
  1984年   55957篇
  1983年   47399篇
  1982年   27433篇
  1981年   24345篇
  1979年   49553篇
  1978年   34506篇
  1977年   29476篇
  1976年   27000篇
  1975年   28859篇
  1974年   34326篇
  1973年   32488篇
  1972年   30490篇
  1971年   28406篇
  1970年   26485篇
  1969年   25360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