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   4078459篇
  免费   307920篇
  国内免费   10199篇
耳鼻咽喉   57575篇
儿科学   131139篇
妇产科学   111410篇
基础医学   570558篇
口腔科学   116985篇
临床医学   375857篇
内科学   791308篇
皮肤病学   91421篇
神经病学   339003篇
特种医学   159531篇
外国民族医学   1438篇
外科学   612293篇
综合类   91215篇
现状与发展   6篇
一般理论   1720篇
预防医学   326022篇
眼科学   94933篇
药学   302010篇
  11篇
中国医学   7982篇
肿瘤学   214161篇
  2018年   44501篇
  2017年   34539篇
  2016年   38764篇
  2015年   43350篇
  2014年   60728篇
  2013年   92111篇
  2012年   123140篇
  2011年   130232篇
  2010年   77885篇
  2009年   74519篇
  2008年   121898篇
  2007年   129480篇
  2006年   131302篇
  2005年   129331篇
  2004年   125560篇
  2003年   119947篇
  2002年   114822篇
  2001年   187072篇
  2000年   192544篇
  1999年   163296篇
  1998年   48485篇
  1997年   43269篇
  1996年   42906篇
  1995年   41613篇
  1994年   38638篇
  1993年   36150篇
  1992年   129758篇
  1991年   125529篇
  1990年   121336篇
  1989年   117246篇
  1988年   108365篇
  1987年   106747篇
  1986年   100819篇
  1985年   96580篇
  1984年   72642篇
  1983年   62032篇
  1982年   37357篇
  1981年   33617篇
  1979年   66752篇
  1978年   47237篇
  1977年   40023篇
  1976年   37492篇
  1975年   39594篇
  1974年   47990篇
  1973年   45812篇
  1972年   43108篇
  1971年   39928篇
  1970年   37308篇
  1969年   35274篇
  1968年   32453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.
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