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   2686985篇
  免费   195318篇
  国内免费   7902篇
耳鼻咽喉   35379篇
儿科学   87676篇
妇产科学   73337篇
基础医学   376611篇
口腔科学   71756篇
临床医学   244566篇
内科学   537120篇
皮肤病学   63858篇
神经病学   223199篇
特种医学   103741篇
外国民族医学   736篇
外科学   403786篇
综合类   51409篇
现状与发展   5篇
一般理论   1087篇
预防医学   203633篇
眼科学   58637篇
药学   194986篇
  8篇
中国医学   5524篇
肿瘤学   153151篇
  2021年   22094篇
  2019年   22626篇
  2018年   31754篇
  2017年   24414篇
  2016年   28196篇
  2015年   31751篇
  2014年   43672篇
  2013年   64952篇
  2012年   87367篇
  2011年   92098篇
  2010年   55392篇
  2009年   53000篇
  2008年   85797篇
  2007年   90968篇
  2006年   92581篇
  2005年   88561篇
  2004年   85443篇
  2003年   82162篇
  2002年   79245篇
  2001年   129827篇
  2000年   132421篇
  1999年   111908篇
  1998年   32606篇
  1997年   28945篇
  1996年   29098篇
  1995年   28140篇
  1994年   25764篇
  1993年   24043篇
  1992年   85894篇
  1991年   82321篇
  1990年   79369篇
  1989年   76707篇
  1988年   70030篇
  1987年   68514篇
  1986年   64083篇
  1985年   61045篇
  1984年   45377篇
  1983年   38331篇
  1982年   22818篇
  1981年   20308篇
  1979年   39212篇
  1978年   27684篇
  1977年   23455篇
  1976年   21653篇
  1975年   22998篇
  1974年   26938篇
  1973年   25538篇
  1972年   23893篇
  1971年   22089篇
  1970年   20313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.

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.
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