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   2778902篇
  免费   198343篇
  国内免费   8098篇
耳鼻咽喉   37049篇
儿科学   90549篇
妇产科学   76079篇
基础医学   390735篇
口腔科学   78205篇
临床医学   247879篇
内科学   555950篇
皮肤病学   67299篇
神经病学   229957篇
特种医学   105383篇
外国民族医学   753篇
外科学   409579篇
综合类   51827篇
现状与发展   6篇
一般理论   1020篇
预防医学   219750篇
眼科学   61347篇
药学   201679篇
  8篇
中国医学   6140篇
肿瘤学   154149篇
  2021年   24103篇
  2019年   24700篇
  2018年   35465篇
  2017年   26748篇
  2016年   30231篇
  2015年   34083篇
  2014年   46271篇
  2013年   68210篇
  2012年   93034篇
  2011年   98120篇
  2010年   57886篇
  2009年   54608篇
  2008年   89530篇
  2007年   95019篇
  2006年   95980篇
  2005年   92189篇
  2004年   88642篇
  2003年   84933篇
  2002年   80659篇
  2001年   132299篇
  2000年   135342篇
  1999年   113913篇
  1998年   32409篇
  1997年   28781篇
  1996年   29101篇
  1995年   28103篇
  1994年   25753篇
  1993年   24092篇
  1992年   87522篇
  1991年   83793篇
  1990年   80932篇
  1989年   78045篇
  1988年   71403篇
  1987年   69838篇
  1986年   65352篇
  1985年   62207篇
  1984年   46254篇
  1983年   39017篇
  1982年   23068篇
  1981年   20543篇
  1979年   40302篇
  1978年   28311篇
  1977年   24107篇
  1976年   22233篇
  1975年   23713篇
  1974年   27915篇
  1973年   26563篇
  1972年   24828篇
  1971年   22967篇
  1970年   21198篇
排序方式: 共有10000条查询结果,搜索用时 375 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.
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