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   2741506篇
  免费   217270篇
  国内免费   9610篇
耳鼻咽喉   38842篇
儿科学   90573篇
妇产科学   74103篇
基础医学   370938篇
口腔科学   71983篇
临床医学   260340篇
内科学   560687篇
皮肤病学   69463篇
神经病学   228757篇
特种医学   106880篇
外国民族医学   742篇
外科学   425294篇
综合类   51080篇
现状与发展   76篇
一般理论   1008篇
预防医学   204850篇
眼科学   60584篇
药学   191031篇
  8篇
中国医学   5400篇
肿瘤学   155747篇
  2021年   22872篇
  2019年   22778篇
  2018年   35866篇
  2017年   29003篇
  2016年   33509篇
  2015年   36879篇
  2014年   54301篇
  2013年   74899篇
  2012年   87024篇
  2011年   91520篇
  2010年   61000篇
  2009年   62201篇
  2008年   86139篇
  2007年   89599篇
  2006年   93330篇
  2005年   87173篇
  2004年   83393篇
  2003年   79835篇
  2002年   77156篇
  2001年   132017篇
  2000年   134226篇
  1999年   113621篇
  1998年   34725篇
  1997年   31081篇
  1996年   31220篇
  1995年   30230篇
  1994年   26855篇
  1993年   24862篇
  1992年   86479篇
  1991年   82959篇
  1990年   79882篇
  1989年   77251篇
  1988年   70502篇
  1987年   68895篇
  1986年   64462篇
  1985年   61279篇
  1984年   45602篇
  1983年   38576篇
  1982年   23094篇
  1981年   20526篇
  1979年   39389篇
  1978年   27877篇
  1977年   23719篇
  1976年   21826篇
  1975年   23172篇
  1974年   27114篇
  1973年   25676篇
  1972年   24108篇
  1971年   22210篇
  1970年   20474篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
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   
3.

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   
4.
5.
6.
7.
8.
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   
9.
10.
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