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   3375818篇
  免费   244948篇
  国内免费   8779篇
耳鼻咽喉   46903篇
儿科学   112276篇
妇产科学   95019篇
基础医学   478386篇
口腔科学   94507篇
临床医学   303791篇
内科学   660107篇
皮肤病学   79180篇
神经病学   273885篇
特种医学   130942篇
外国民族医学   1047篇
外科学   510260篇
综合类   69448篇
现状与发展   6篇
一般理论   1194篇
预防医学   257969篇
眼科学   76885篇
药学   249399篇
  9篇
中国医学   6803篇
肿瘤学   181529篇
  2018年   36223篇
  2017年   27682篇
  2016年   32023篇
  2015年   36185篇
  2014年   49817篇
  2013年   75212篇
  2012年   100181篇
  2011年   106358篇
  2010年   64043篇
  2009年   61249篇
  2008年   100022篇
  2007年   106717篇
  2006年   108694篇
  2005年   104623篇
  2004年   100755篇
  2003年   97521篇
  2002年   94651篇
  2001年   158046篇
  2000年   161971篇
  1999年   136952篇
  1998年   39754篇
  1997年   35262篇
  1996年   35522篇
  1995年   34181篇
  1994年   31635篇
  1993年   29678篇
  1992年   108024篇
  1991年   104695篇
  1990年   101939篇
  1989年   98777篇
  1988年   90983篇
  1987年   89329篇
  1986年   84276篇
  1985年   80544篇
  1984年   59840篇
  1983年   51383篇
  1982年   30607篇
  1981年   27189篇
  1979年   54264篇
  1978年   38302篇
  1977年   32831篇
  1976年   30588篇
  1975年   33011篇
  1974年   38867篇
  1973年   37102篇
  1972年   35178篇
  1971年   32577篇
  1970年   30402篇
  1969年   29185篇
  1968年   27061篇
排序方式: 共有10000条查询结果,搜索用时 752 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