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   4139424篇
  免费   314091篇
  国内免费   15438篇
耳鼻咽喉   58230篇
儿科学   131124篇
妇产科学   112192篇
基础医学   577660篇
口腔科学   118191篇
临床医学   385238篇
内科学   799853篇
皮肤病学   92114篇
神经病学   341923篇
特种医学   161402篇
外国民族医学   1491篇
外科学   617330篇
综合类   101505篇
现状与发展   27篇
一般理论   1739篇
预防医学   329971篇
眼科学   97492篇
药学   309012篇
  78篇
中国医学   12059篇
肿瘤学   220322篇
  2021年   33755篇
  2019年   33771篇
  2018年   46479篇
  2017年   35965篇
  2016年   40569篇
  2015年   46630篇
  2014年   65004篇
  2013年   95860篇
  2012年   127935篇
  2011年   135840篇
  2010年   81591篇
  2009年   77215篇
  2008年   125636篇
  2007年   133097篇
  2006年   134974篇
  2005年   130523篇
  2004年   124694篇
  2003年   120076篇
  2002年   116524篇
  2001年   188346篇
  2000年   193870篇
  1999年   164962篇
  1998年   49632篇
  1997年   44426篇
  1996年   43802篇
  1995年   42455篇
  1994年   39353篇
  1993年   36584篇
  1992年   130189篇
  1991年   125878篇
  1990年   121670篇
  1989年   117531篇
  1988年   108629篇
  1987年   106954篇
  1986年   100995篇
  1985年   96717篇
  1984年   72712篇
  1983年   62080篇
  1982年   37378篇
  1979年   66781篇
  1978年   47244篇
  1977年   40028篇
  1976年   37498篇
  1975年   39598篇
  1974年   48001篇
  1973年   45823篇
  1972年   43112篇
  1971年   39928篇
  1970年   37310篇
  1969年   35283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.
Molnár  B.  Aroca  S.  Dobos  A.  Orbán  K.  Szabó  J.  Windisch  P.  Stähli  A.  Sculean  A. 《Clinical oral investigations》2022,26(12):7135-7142
Clinical Oral Investigations - To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with...  相似文献   
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.
目的 应用可视化方法分析代谢组学在中医药领域的现状及趋势。方法 检索中国知网数据库(CNKI)和Web of Science 核心合集数据库2021年3月15日之前收录的中医药领域代谢组学研究的相关文献,应用CiteSpace软件对纳入的文献进行关键词、作者、研究机构等内容进行可视化分析。结果 共纳入中文文献247篇,英文文献350篇。文献数量在波动中迅速上升。中、英文文献作者合作网络显示,张爱华是中医药领域代谢组学研究发文量最多的作者,并形成了核心研究团队。发文机构显示,中国医学科学院是该领域的重要研究机构,机构间合作紧密。中、英文文献关键词分析显示,研究内容主要集中在核磁共振、代谢标记物、冠心病、质谱技术、代谢通路等相关领域。结论 中医药领域代谢组学研究的热点主要为中医药治疗代谢性疾病的机制研究。研究趋势为卵泡代谢组学研究及中药有效成分的研究。  相似文献   
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