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   4221277篇
  免费   330167篇
  国内免费   13880篇
耳鼻咽喉   58697篇
儿科学   134831篇
妇产科学   110421篇
基础医学   651246篇
口腔科学   114029篇
临床医学   382108篇
内科学   760613篇
皮肤病学   106022篇
神经病学   350091篇
特种医学   163685篇
外国民族医学   503篇
外科学   647090篇
综合类   119220篇
现状与发展   23篇
一般理论   2566篇
预防医学   353417篇
眼科学   98862篇
药学   294685篇
  26篇
中国医学   11351篇
肿瘤学   205838篇
  2021年   55904篇
  2020年   35598篇
  2019年   58553篇
  2018年   73826篇
  2017年   56375篇
  2016年   62409篇
  2015年   75514篇
  2014年   109912篇
  2013年   175029篇
  2012年   120964篇
  2011年   126599篇
  2010年   125377篇
  2009年   126664篇
  2008年   112710篇
  2007年   120059篇
  2006年   128711篇
  2005年   123901篇
  2004年   124108篇
  2003年   114506篇
  2002年   103721篇
  2001年   149726篇
  2000年   144563篇
  1999年   134329篇
  1998年   70089篇
  1997年   66212篇
  1996年   64424篇
  1995年   59688篇
  1994年   53776篇
  1993年   50043篇
  1992年   96054篇
  1991年   92655篇
  1990年   89069篇
  1989年   86826篇
  1988年   80028篇
  1987年   78519篇
  1986年   73865篇
  1985年   72990篇
  1984年   61676篇
  1983年   55440篇
  1982年   46017篇
  1981年   43119篇
  1980年   40506篇
  1979年   53103篇
  1978年   44034篇
  1977年   38888篇
  1976年   36265篇
  1975年   36277篇
  1974年   39409篇
  1973年   37635篇
  1972年   35245篇
排序方式: 共有10000条查询结果,搜索用时 31 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.

Physical activity brings significant health benefits to middle-aged adults, although the research to date has been focused on late adulthood. This study aims to examine how ageing affects the self-reported and accelerometer-derived measures of physical activity levels in middle-aged adults. We employed the data recorded in the UK Biobank and analysed the physical activity levels of 2,998 participants (1381 men and 1617 women), based on self-completion questionnaire and accelerometry measurement of physical activity. We also assessed the musculoskeletal health of the participants using the dual-energy X-ray absorptiometry (DXA) measurements provided by the UK Biobank. Participants were categorised into three groups according to their age: group I younger middle-aged (40 to 49 years), group II older middle-aged (50 to 59 years), and group III oldest middle-aged (60 to 69 years). Self-reported physical activity level increased with age and was the highest in group III, followed by group II and I (P?<?0.05). On the contrary, physical activity measured by accelerometry decreased significantly with age from group I to III (P?<?0.05), and the same pertained to the measurements of musculoskeletal health (P?<?0.05). It was also shown that middle-aged adults mostly engaged in low and moderate intensity activities. The opposing trends of the self-reported and measured physical activity levels may suggest that middle-aged adults over-report their activity level as they age. They should be aware of the difference between their perceived and actual physical activity levels, and objective measures would be useful to prevent the decline in musculoskeletal health.

  相似文献   
4.
5.

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   
6.
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