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   2770320篇
  免费   203011篇
  国内免费   8047篇
耳鼻咽喉   36469篇
儿科学   90079篇
妇产科学   74849篇
基础医学   388134篇
口腔科学   73413篇
临床医学   253775篇
内科学   554196篇
皮肤病学   64917篇
神经病学   231826篇
特种医学   105732篇
外国民族医学   744篇
外科学   414340篇
综合类   53213篇
现状与发展   5篇
一般理论   1250篇
预防医学   212877篇
眼科学   61794篇
药学   201133篇
  14篇
中国医学   5604篇
肿瘤学   157014篇
  2021年   23848篇
  2019年   24431篇
  2018年   33590篇
  2017年   25860篇
  2016年   29707篇
  2015年   33653篇
  2014年   46721篇
  2013年   69381篇
  2012年   93414篇
  2011年   98421篇
  2010年   58994篇
  2009年   56203篇
  2008年   91361篇
  2007年   96907篇
  2006年   98553篇
  2005年   94732篇
  2004年   90871篇
  2003年   87331篇
  2002年   83999篇
  2001年   129951篇
  2000年   132497篇
  1999年   112239篇
  1998年   33534篇
  1997年   29829篇
  1996年   29836篇
  1995年   28883篇
  1994年   26363篇
  1993年   24554篇
  1992年   86070篇
  1991年   82375篇
  1990年   79498篇
  1989年   76742篇
  1988年   70163篇
  1987年   68656篇
  1986年   64193篇
  1985年   61196篇
  1984年   45838篇
  1983年   38798篇
  1982年   23508篇
  1981年   21024篇
  1979年   39508篇
  1978年   28022篇
  1977年   23776篇
  1976年   21973篇
  1975年   23227篇
  1974年   27196篇
  1973年   25723篇
  1972年   24049篇
  1971年   22174篇
  1970年   20384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