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   3374017篇
  免费   244825篇
  国内免费   8774篇
耳鼻咽喉   46853篇
儿科学   112168篇
妇产科学   94934篇
基础医学   478166篇
口腔科学   94426篇
临床医学   303677篇
内科学   659599篇
皮肤病学   79145篇
神经病学   273740篇
特种医学   130855篇
外国民族医学   1047篇
外科学   510042篇
综合类   69441篇
现状与发展   6篇
一般理论   1192篇
预防医学   257900篇
眼科学   76830篇
药学   249401篇
  9篇
中国医学   6797篇
肿瘤学   181388篇
  2018年   36128篇
  2017年   27618篇
  2016年   31950篇
  2015年   36116篇
  2014年   49750篇
  2013年   75109篇
  2012年   100053篇
  2011年   106216篇
  2010年   63963篇
  2009年   61169篇
  2008年   99929篇
  2007年   106632篇
  2006年   108599篇
  2005年   104500篇
  2004年   100686篇
  2003年   97456篇
  2002年   94583篇
  2001年   158035篇
  2000年   161958篇
  1999年   136946篇
  1998年   39751篇
  1997年   35261篇
  1996年   35515篇
  1995年   34182篇
  1994年   31638篇
  1993年   29680篇
  1992年   108019篇
  1991年   104695篇
  1990年   101939篇
  1989年   98780篇
  1988年   90986篇
  1987年   89326篇
  1986年   84276篇
  1985年   80543篇
  1984年   59843篇
  1983年   51385篇
  1982年   30605篇
  1981年   27188篇
  1979年   54265篇
  1978年   38300篇
  1977年   32828篇
  1976年   30593篇
  1975年   33009篇
  1974年   38873篇
  1973年   37098篇
  1972年   35177篇
  1971年   32577篇
  1970年   30397篇
  1969年   29180篇
  1968年   27052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