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   4547734篇
  免费   329536篇
  国内免费   9884篇
耳鼻咽喉   64619篇
儿科学   150744篇
妇产科学   125913篇
基础医学   646069篇
口腔科学   128911篇
临床医学   420016篇
内科学   871158篇
皮肤病学   104147篇
神经病学   367550篇
特种医学   172589篇
外国民族医学   1649篇
外科学   681954篇
综合类   98755篇
现状与发展   15篇
一般理论   1814篇
预防医学   359329篇
眼科学   107785篇
药学   337006篇
  17篇
中国医学   8894篇
肿瘤学   238220篇
  2018年   49664篇
  2017年   37619篇
  2016年   43096篇
  2015年   48515篇
  2014年   67925篇
  2013年   103418篇
  2012年   139436篇
  2011年   148481篇
  2010年   89458篇
  2009年   84681篇
  2008年   139010篇
  2007年   148040篇
  2006年   149915篇
  2005年   144969篇
  2004年   139905篇
  2003年   134892篇
  2002年   130802篇
  2001年   203823篇
  2000年   209572篇
  1999年   177878篇
  1998年   53408篇
  1997年   46822篇
  1996年   46776篇
  1995年   44868篇
  1994年   41501篇
  1993年   38974篇
  1992年   140600篇
  1991年   136933篇
  1990年   133330篇
  1989年   129156篇
  1988年   119142篇
  1987年   117117篇
  1986年   110243篇
  1985年   105932篇
  1984年   79595篇
  1983年   67927篇
  1982年   40420篇
  1981年   36561篇
  1979年   73051篇
  1978年   51815篇
  1977年   44126篇
  1976年   41401篇
  1975年   44428篇
  1974年   52907篇
  1973年   50636篇
  1972年   47707篇
  1971年   44562篇
  1970年   41488篇
  1969年   39453篇
  1968年   36259篇
排序方式: 共有10000条查询结果,搜索用时 218 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.
Journal of Medical Ultrasonics - Chronic liver disease is still a major problem because disease progression will ultimately lead to liver cirrhosis. Portal hypertension is the hallmark in advanced...  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