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   2654649篇
  免费   194157篇
  国内免费   7882篇
耳鼻咽喉   35158篇
儿科学   86884篇
妇产科学   72663篇
基础医学   372831篇
口腔科学   71510篇
临床医学   241651篇
内科学   530722篇
皮肤病学   63601篇
神经病学   220236篇
特种医学   102890篇
外国民族医学   737篇
外科学   398478篇
综合类   50982篇
现状与发展   5篇
一般理论   1146篇
预防医学   201072篇
眼科学   57952篇
药学   192444篇
  8篇
中国医学   5440篇
肿瘤学   150278篇
  2021年   22311篇
  2019年   22708篇
  2018年   31724篇
  2017年   24350篇
  2016年   28048篇
  2015年   31555篇
  2014年   43370篇
  2013年   64242篇
  2012年   85863篇
  2011年   90298篇
  2010年   54258篇
  2009年   52011篇
  2008年   83875篇
  2007年   88539篇
  2006年   90114篇
  2005年   86206篇
  2004年   82782篇
  2003年   79816篇
  2002年   76705篇
  2001年   128842篇
  2000年   131653篇
  1999年   110979篇
  1998年   31947篇
  1997年   28455篇
  1996年   28643篇
  1995年   27790篇
  1994年   25407篇
  1993年   23754篇
  1992年   85412篇
  1991年   81789篇
  1990年   78971篇
  1989年   76242篇
  1988年   69654篇
  1987年   68173篇
  1986年   63718篇
  1985年   60678篇
  1984年   45170篇
  1983年   38145篇
  1982年   22683篇
  1981年   20236篇
  1979年   39065篇
  1978年   27571篇
  1977年   23385篇
  1976年   21586篇
  1975年   22899篇
  1974年   26869篇
  1973年   25446篇
  1972年   23821篇
  1971年   22020篇
  1970年   20229篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
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.
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   
7.
8.
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