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   3384669篇
  免费   245517篇
  国内免费   8794篇
耳鼻咽喉   46962篇
儿科学   112488篇
妇产科学   95102篇
基础医学   479280篇
口腔科学   94741篇
临床医学   305191篇
内科学   662132篇
皮肤病学   79248篇
神经病学   274648篇
特种医学   131127篇
外国民族医学   1050篇
外科学   511016篇
综合类   69687篇
现状与发展   6篇
一般理论   1202篇
预防医学   259186篇
眼科学   77129篇
药学   249979篇
  9篇
中国医学   6799篇
肿瘤学   181998篇
  2018年   36267篇
  2017年   27716篇
  2016年   32061篇
  2015年   36231篇
  2014年   49923篇
  2013年   75350篇
  2012年   100450篇
  2011年   106605篇
  2010年   64202篇
  2009年   61371篇
  2008年   100312篇
  2007年   107005篇
  2006年   108989篇
  2005年   104886篇
  2004年   101064篇
  2003年   97820篇
  2002年   94907篇
  2001年   158262篇
  2000年   162156篇
  1999年   137151篇
  1998年   39861篇
  1997年   35344篇
  1996年   35602篇
  1995年   34273篇
  1994年   31712篇
  1993年   29744篇
  1992年   108201篇
  1991年   104858篇
  1990年   102104篇
  1989年   98943篇
  1988年   91133篇
  1987年   89458篇
  1986年   84406篇
  1985年   80650篇
  1984年   59922篇
  1983年   51470篇
  1982年   30686篇
  1981年   27240篇
  1979年   54360篇
  1978年   38372篇
  1977年   32897篇
  1976年   30658篇
  1975年   33063篇
  1974年   38946篇
  1973年   37182篇
  1972年   35261篇
  1971年   32636篇
  1970年   30473篇
  1969年   29226篇
  1968年   27096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