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   2698008篇
  免费   195331篇
  国内免费   7931篇
耳鼻咽喉   35991篇
儿科学   88594篇
妇产科学   74012篇
基础医学   378422篇
口腔科学   75709篇
临床医学   243100篇
内科学   540176篇
皮肤病学   65170篇
神经病学   223075篇
特种医学   103241篇
外国民族医学   752篇
外科学   401068篇
综合类   51405篇
现状与发展   6篇
一般理论   1009篇
预防医学   208524篇
眼科学   59095篇
药学   194920篇
  8篇
中国医学   5852篇
肿瘤学   151141篇
  2021年   23106篇
  2019年   23387篇
  2018年   33032篇
  2017年   25191篇
  2016年   28689篇
  2015年   32455篇
  2014年   44556篇
  2013年   65552篇
  2012年   88229篇
  2011年   93103篇
  2010年   55420篇
  2009年   52933篇
  2008年   85456篇
  2007年   90638篇
  2006年   91828篇
  2005年   88114篇
  2004年   84801篇
  2003年   81374篇
  2002年   77218篇
  2001年   130535篇
  2000年   133369篇
  1999年   112361篇
  1998年   32155篇
  1997年   28656篇
  1996年   28918篇
  1995年   27957篇
  1994年   25641篇
  1993年   23983篇
  1992年   86469篇
  1991年   82789篇
  1990年   79902篇
  1989年   77173篇
  1988年   70518篇
  1987年   69002篇
  1986年   64478篇
  1985年   61384篇
  1984年   45633篇
  1983年   38504篇
  1982年   22783篇
  1981年   20300篇
  1979年   39530篇
  1978年   27776篇
  1977年   23558篇
  1976年   21732篇
  1975年   23146篇
  1974年   27133篇
  1973年   25721篇
  1972年   24035篇
  1971年   22219篇
  1970年   20480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.
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