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   4278594篇
  免费   342515篇
  国内免费   14462篇
耳鼻咽喉   60196篇
儿科学   136618篇
妇产科学   111281篇
基础医学   653090篇
口腔科学   114295篇
临床医学   393796篇
内科学   774977篇
皮肤病学   110063篇
神经病学   356512篇
特种医学   166016篇
外国民族医学   504篇
外科学   663385篇
综合类   119539篇
现状与发展   91篇
一般理论   2601篇
预防医学   355782篇
眼科学   100656篇
药学   295405篇
  26篇
中国医学   11312篇
肿瘤学   209426篇
  2021年   56698篇
  2020年   37806篇
  2019年   59076篇
  2018年   76738篇
  2017年   59376篇
  2016年   65703篇
  2015年   78626篇
  2014年   115675篇
  2013年   180674篇
  2012年   123297篇
  2011年   128902篇
  2010年   129587篇
  2009年   132200篇
  2008年   115268篇
  2007年   122012篇
  2006年   131525篇
  2005年   125926篇
  2004年   125797篇
  2003年   115910篇
  2002年   105110篇
  2001年   150988篇
  2000年   145465篇
  1999年   135324篇
  1998年   71481篇
  1997年   67397篇
  1996年   65281篇
  1995年   60479篇
  1994年   54253篇
  1993年   50385篇
  1992年   96422篇
  1991年   93113篇
  1990年   89407篇
  1989年   87198篇
  1988年   80330篇
  1987年   78793篇
  1986年   74142篇
  1985年   73200篇
  1984年   61802篇
  1983年   55545篇
  1982年   46124篇
  1981年   43186篇
  1980年   40575篇
  1979年   53173篇
  1978年   44104篇
  1977年   38958篇
  1976年   36322篇
  1975年   36322篇
  1974年   39485篇
  1973年   37690篇
  1972年   35302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.

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.
8.
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   
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