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   2787932篇
  免费   201785篇
  国内免费   7737篇
耳鼻咽喉   37686篇
儿科学   92504篇
妇产科学   77472篇
基础医学   394176篇
口腔科学   75858篇
临床医学   252575篇
内科学   551320篇
皮肤病学   66751篇
神经病学   228240篇
特种医学   107705篇
外国民族医学   770篇
外科学   418050篇
综合类   56246篇
现状与发展   6篇
一般理论   1122篇
预防医学   212091篇
眼科学   62047篇
药学   203157篇
  9篇
中国医学   5822篇
肿瘤学   153847篇
  2021年   21592篇
  2019年   22303篇
  2018年   31692篇
  2017年   24332篇
  2016年   28233篇
  2015年   31769篇
  2014年   43559篇
  2013年   65572篇
  2012年   86531篇
  2011年   91211篇
  2010年   55319篇
  2009年   52988篇
  2008年   85074篇
  2007年   90483篇
  2006年   92058篇
  2005年   88071篇
  2004年   84831篇
  2003年   81862篇
  2002年   78824篇
  2001年   135714篇
  2000年   138933篇
  1999年   117023篇
  1998年   33253篇
  1997年   29683篇
  1996年   29905篇
  1995年   28974篇
  1994年   26602篇
  1993年   24895篇
  1992年   90318篇
  1991年   86918篇
  1990年   84231篇
  1989年   81353篇
  1988年   74439篇
  1987年   72846篇
  1986年   68148篇
  1985年   65078篇
  1984年   48337篇
  1983年   40881篇
  1982年   24297篇
  1981年   21590篇
  1979年   42367篇
  1978年   29927篇
  1977年   25416篇
  1976年   23428篇
  1975年   25030篇
  1974年   29526篇
  1973年   28148篇
  1972年   26369篇
  1971年   24407篇
  1970年   22548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.
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