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   2594724篇
  免费   190432篇
  国内免费   7597篇
耳鼻咽喉   34420篇
儿科学   85585篇
妇产科学   71906篇
基础医学   365216篇
口腔科学   70357篇
临床医学   235436篇
内科学   517812篇
皮肤病学   62792篇
神经病学   214576篇
特种医学   100347篇
外国民族医学   736篇
外科学   388215篇
综合类   50470篇
现状与发展   5篇
一般理论   973篇
预防医学   197019篇
眼科学   56864篇
药学   188749篇
  8篇
中国医学   5376篇
肿瘤学   145891篇
  2021年   20355篇
  2019年   21046篇
  2018年   29762篇
  2017年   22930篇
  2016年   26588篇
  2015年   29898篇
  2014年   41006篇
  2013年   61042篇
  2012年   81132篇
  2011年   85429篇
  2010年   51585篇
  2009年   49621篇
  2008年   79756篇
  2007年   84598篇
  2006年   86257篇
  2005年   82394篇
  2004年   79257篇
  2003年   76583篇
  2002年   73793篇
  2001年   128643篇
  2000年   131577篇
  1999年   110738篇
  1998年   31368篇
  1997年   28025篇
  1996年   28312篇
  1995年   27472篇
  1994年   25146篇
  1993年   23484篇
  1992年   85337篇
  1991年   81725篇
  1990年   78922篇
  1989年   76233篇
  1988年   69601篇
  1987年   68126篇
  1986年   63663篇
  1985年   60634篇
  1984年   45028篇
  1983年   38035篇
  1982年   22505篇
  1981年   20027篇
  1979年   39019篇
  1978年   27504篇
  1977年   23289篇
  1976年   21546篇
  1975年   22841篇
  1974年   26824篇
  1973年   25414篇
  1972年   23793篇
  1971年   21981篇
  1970年   20219篇
排序方式: 共有10000条查询结果,搜索用时 343 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