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   4238346篇
  免费   312395篇
  国内免费   10682篇
耳鼻咽喉   60498篇
儿科学   137968篇
妇产科学   116789篇
基础医学   592082篇
口腔科学   123097篇
临床医学   388138篇
内科学   814767篇
皮肤病学   96396篇
神经病学   350169篇
特种医学   168233篇
外国民族医学   1509篇
外科学   637991篇
综合类   92439篇
现状与发展   6篇
一般理论   1735篇
预防医学   337057篇
眼科学   99459篇
药学   313862篇
  13篇
中国医学   8195篇
肿瘤学   221020篇
  2018年   47779篇
  2017年   37662篇
  2016年   42042篇
  2015年   48018篇
  2014年   65289篇
  2013年   96955篇
  2012年   132336篇
  2011年   136683篇
  2010年   81627篇
  2009年   78718篇
  2008年   126796篇
  2007年   135232篇
  2006年   137043篇
  2005年   138766篇
  2004年   135185篇
  2003年   127528篇
  2002年   120580篇
  2001年   190222篇
  2000年   194939篇
  1999年   166744篇
  1998年   49496篇
  1997年   43975篇
  1996年   40614篇
  1995年   41900篇
  1994年   38910篇
  1993年   36373篇
  1992年   132780篇
  1991年   129128篇
  1990年   125072篇
  1989年   120861篇
  1988年   111714篇
  1987年   109980篇
  1986年   104125篇
  1985年   99537篇
  1984年   74709篇
  1983年   63668篇
  1982年   37962篇
  1981年   34103篇
  1979年   69151篇
  1978年   48735篇
  1977年   41192篇
  1976年   38525篇
  1975年   41362篇
  1974年   50182篇
  1973年   47795篇
  1972年   45167篇
  1971年   41995篇
  1970年   39240篇
  1969年   37116篇
  1968年   34229篇
排序方式: 共有10000条查询结果,搜索用时 46 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.
4.

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   
5.
6.
7.
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   
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