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   2653577篇
  免费   188186篇
  国内免费   6173篇
耳鼻咽喉   36424篇
儿科学   84504篇
妇产科学   70932篇
基础医学   390646篇
口腔科学   71439篇
临床医学   238209篇
内科学   511753篇
皮肤病学   59511篇
神经病学   206184篇
特种医学   104218篇
外国民族医学   590篇
外科学   396723篇
综合类   54004篇
现状与发展   20篇
一般理论   931篇
预防医学   204579篇
眼科学   62153篇
药学   199355篇
  31篇
中国医学   7243篇
肿瘤学   148487篇
  2021年   24563篇
  2019年   23472篇
  2018年   34822篇
  2017年   27423篇
  2016年   29989篇
  2015年   35872篇
  2014年   47112篇
  2013年   65396篇
  2012年   95801篇
  2011年   95866篇
  2010年   56392篇
  2009年   53962篇
  2008年   85506篇
  2007年   90791篇
  2006年   91288篇
  2005年   95667篇
  2004年   93535篇
  2003年   85583篇
  2002年   77338篇
  2001年   115048篇
  2000年   116049篇
  1999年   99744篇
  1998年   28753篇
  1997年   24946篇
  1996年   25262篇
  1995年   23837篇
  1994年   21874篇
  1993年   20516篇
  1992年   77423篇
  1991年   75678篇
  1990年   74049篇
  1989年   71026篇
  1988年   65381篇
  1987年   63910篇
  1986年   59878篇
  1985年   57098篇
  1984年   42142篇
  1983年   35754篇
  1982年   20839篇
  1979年   38907篇
  1978年   27601篇
  1977年   22829篇
  1976年   21671篇
  1975年   23784篇
  1974年   28606篇
  1973年   27037篇
  1972年   25464篇
  1971年   24218篇
  1970年   22281篇
  1969年   21231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.
6.
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   
7.
8.
9.
综述信息化技术在静脉血栓栓塞症护理领域中风险预测、警报接收与上报、抗凝防治管理、医护人员相关继续医学教育、患者疾病预后管理的应用现状,总结其应用阻碍因素,旨在为我国静脉血栓栓塞症护理信息化建设提供参考。  相似文献   
10.
Noninvasive imaging of cardiac fibrosis is important for early diagnosis and intervention in chronic heart diseases. Here, we investigated whether noninvasive, contrast agent-free MRI T2-mapping can quantify myocardial fibrosis in preclinical models of aging and pressure overload. Myocardial fibrosis and remodeling were analyzed in two animal models: (i) aging (15-month-old male CF-1 mice vs. young 6- to 8-week-old mice), and (ii) pressure overload (PO; by transverse aortic constriction in 4- to 5-month-old male C57BL/6 mice vs. sham-operated for 14 days). In vivo T2-mapping was performed by acquiring data during the isovolumic and early diastolic phases, with a modified respiratory and ECG-triggered multiecho TurboRARE sequence on a 7-T MRI. Cine MRI provided cardiac morphology and function. A quantitative segmentation method was developed to analyze the in vivo T2-maps of hearts at midventricle, apex, and basal regions. The cardiac fibrosis area was analyzed ex vivo by picro sirius red (PSR) staining. Both aged and pressure-overloaded hearts developed significant myocardial contractile dysfunction, cardiac hypertrophy, and interstitial fibrosis. The aged mice had two phenotypes, fibrotic and mild-fibrotic. Notably, the aged fibrotic subgroup and the PO mice showed a marked decrease in T2 relaxation times (25.3 ± 0.6 in aged vs. 29.9 ± 0.7 ms in young mice, p = 0.002; and 24.3 ± 1.7 in PO vs. 28.7 ± 0.7 ms in shams, p = 0.05). However, no significant difference in T2 was detected between the aged mild-fibrotic subgroup and the young mice. Accordingly, an inverse correlation between myocardial fibrosis percentage (FP) and T2 relaxation time was derived (R2 = 0.98): T2 (ms) = 30.45 – 1.05 × FP. Thus, these results demonstrate a statistical agreement between T2-map–quantified fibrosis and PSR staining in two different clinically relevant animal models. In conclusion, T2-mapping MRI is a promising noninvasive contrast agent-free quantitative technique to characterize myocardial fibrosis.  相似文献   
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