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   2912367篇
  免费   205591篇
  国内免费   7853篇
耳鼻咽喉   38896篇
儿科学   95859篇
妇产科学   79683篇
基础医学   421113篇
口腔科学   78081篇
临床医学   265587篇
内科学   571107篇
皮肤病学   69841篇
神经病学   233926篇
特种医学   111861篇
外国民族医学   774篇
外科学   435445篇
综合类   55702篇
现状与发展   6篇
一般理论   1046篇
预防医学   221528篇
眼科学   64821篇
药学   213771篇
  9篇
中国医学   5976篇
肿瘤学   160779篇
  2019年   22861篇
  2018年   32582篇
  2017年   24951篇
  2016年   29014篇
  2015年   32592篇
  2014年   44616篇
  2013年   66723篇
  2012年   89530篇
  2011年   95156篇
  2010年   57181篇
  2009年   54386篇
  2008年   88572篇
  2007年   94439篇
  2006年   95847篇
  2005年   91695篇
  2004年   88355篇
  2003年   85496篇
  2002年   82476篇
  2001年   140025篇
  2000年   143269篇
  1999年   120612篇
  1998年   34360篇
  1997年   30428篇
  1996年   30713篇
  1995年   29681篇
  1994年   27190篇
  1993年   25596篇
  1992年   93422篇
  1991年   91054篇
  1990年   88400篇
  1989年   85606篇
  1988年   78396篇
  1987年   76871篇
  1986年   71907篇
  1985年   68745篇
  1984年   51040篇
  1983年   43140篇
  1982年   25152篇
  1981年   22526篇
  1979年   45100篇
  1978年   31828篇
  1977年   26806篇
  1976年   25351篇
  1975年   27467篇
  1974年   32087篇
  1973年   30498篇
  1972年   28514篇
  1971年   26583篇
  1970年   24547篇
  1969年   23515篇
排序方式: 共有10000条查询结果,搜索用时 109 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.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses...  相似文献   
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