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   3381414篇
  免费   245120篇
  国内免费   8800篇
耳鼻咽喉   46975篇
儿科学   112420篇
妇产科学   95070篇
基础医学   478970篇
口腔科学   94548篇
临床医学   304501篇
内科学   661419篇
皮肤病学   79202篇
神经病学   274403篇
特种医学   131017篇
外国民族医学   1047篇
外科学   510802篇
综合类   69530篇
现状与发展   6篇
一般理论   1207篇
预防医学   258564篇
眼科学   77093篇
药学   249772篇
  9篇
中国医学   6807篇
肿瘤学   181972篇
  2018年   36303篇
  2017年   27765篇
  2016年   32110篇
  2015年   36273篇
  2014年   49948篇
  2013年   75375篇
  2012年   100473篇
  2011年   106558篇
  2010年   64205篇
  2009年   61357篇
  2008年   100184篇
  2007年   106931篇
  2006年   108844篇
  2005年   104731篇
  2004年   100921篇
  2003年   97672篇
  2002年   94805篇
  2001年   158072篇
  2000年   161985篇
  1999年   137004篇
  1998年   39783篇
  1997年   35295篇
  1996年   35540篇
  1995年   34199篇
  1994年   31646篇
  1993年   29689篇
  1992年   108038篇
  1991年   104725篇
  1990年   101950篇
  1989年   98800篇
  1988年   90993篇
  1987年   89339篇
  1986年   84293篇
  1985年   80554篇
  1984年   59851篇
  1983年   51391篇
  1982年   30625篇
  1981年   27203篇
  1979年   54289篇
  1978年   38313篇
  1977年   32839篇
  1976年   30599篇
  1975年   33017篇
  1974年   38873篇
  1973年   37114篇
  1972年   35184篇
  1971年   32587篇
  1970年   30404篇
  1969年   29187篇
  1968年   27052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