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   2611551篇
  免费   191236篇
  国内免费   7622篇
耳鼻咽喉   34570篇
儿科学   85952篇
妇产科学   72170篇
基础医学   367283篇
口腔科学   70150篇
临床医学   237312篇
内科学   520665篇
皮肤病学   62854篇
神经病学   216484篇
特种医学   100832篇
外国民族医学   736篇
外科学   391131篇
综合类   50756篇
现状与发展   6篇
一般理论   998篇
预防医学   198656篇
眼科学   57435篇
药学   189948篇
  9篇
中国医学   5415篇
肿瘤学   147047篇
  2021年   20601篇
  2019年   21201篇
  2018年   30042篇
  2017年   23116篇
  2016年   26751篇
  2015年   30112篇
  2014年   41401篇
  2013年   61708篇
  2012年   82257篇
  2011年   86594篇
  2010年   52202篇
  2009年   50196篇
  2008年   80995篇
  2007年   85947篇
  2006年   87600篇
  2005年   83692篇
  2004年   80643篇
  2003年   77804篇
  2002年   75018篇
  2001年   128688篇
  2000年   131589篇
  1999年   110770篇
  1998年   31580篇
  1997年   28183篇
  1996年   28508篇
  1995年   27605篇
  1994年   25274篇
  1993年   23615篇
  1992年   85316篇
  1991年   81702篇
  1990年   78898篇
  1989年   76173篇
  1988年   69589篇
  1987年   68095篇
  1986年   63644篇
  1985年   60604篇
  1984年   45056篇
  1983年   38057篇
  1982年   22600篇
  1981年   20126篇
  1979年   39027篇
  1978年   27521篇
  1977年   23345篇
  1976年   21565篇
  1975年   22883篇
  1974年   26841篇
  1973年   25426篇
  1972年   23788篇
  1971年   21988篇
  1970年   20215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