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   526579篇
  免费   28123篇
  国内免费   482篇
耳鼻咽喉   6675篇
儿科学   16881篇
妇产科学   12536篇
基础医学   92142篇
口腔科学   12325篇
临床医学   48120篇
内科学   94479篇
皮肤病学   11857篇
神经病学   33772篇
特种医学   19740篇
外国民族医学   53篇
外科学   77874篇
综合类   7603篇
现状与发展   2篇
一般理论   107篇
预防医学   38316篇
眼科学   11843篇
药学   41301篇
  1篇
中国医学   1075篇
肿瘤学   28482篇
  2019年   3891篇
  2018年   5733篇
  2017年   4125篇
  2016年   4872篇
  2015年   5362篇
  2014年   7118篇
  2013年   10503篇
  2012年   15578篇
  2011年   17396篇
  2010年   9962篇
  2009年   8822篇
  2008年   15714篇
  2007年   17451篇
  2006年   16945篇
  2005年   16263篇
  2004年   15874篇
  2003年   15239篇
  2002年   14768篇
  2001年   22390篇
  2000年   22907篇
  1999年   18804篇
  1998年   4977篇
  1997年   4079篇
  1996年   4119篇
  1995年   4104篇
  1992年   14395篇
  1991年   15819篇
  1990年   15944篇
  1989年   15623篇
  1988年   14301篇
  1987年   14187篇
  1986年   13165篇
  1985年   12679篇
  1984年   9387篇
  1983年   7991篇
  1982年   4163篇
  1979年   8924篇
  1978年   6363篇
  1977年   5130篇
  1976年   5494篇
  1975年   6604篇
  1974年   7413篇
  1973年   7156篇
  1972年   6591篇
  1971年   6307篇
  1970年   5884篇
  1969年   5460篇
  1968年   5158篇
  1967年   4618篇
  1966年   3962篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
33.
Journal of Thrombosis and Thrombolysis - Over the last few years data from our group have indicated that α-synuclein is important in development of immune cells as well as potentially...  相似文献   
34.
PurposeAnaerobic infections are common yet life-threatening. They are being recovered from all sites of the body, including the cardiovascular system. This study was aimed to determine the retrospective analysis on the isolation of anaerobes in cardiovascular samples received for a decade-long duration. It helps in knowing the frequency of isolation of anaerobic causes of cardiovascular infection.MethodsAll cardiovascular samples from the department of Cardio-thoracic vascular surgery from January 2010 to December 2020 were studied.ResultsOf 601 samples received, predominant samples were vegetations and valvular tissues of 258, followed by 98 samples of pericardial tissues, 92 samples of embolus, 90 samples of blood and post-operative collections, and 63 excised aneurysms and vascular grafts. Of the total, 15 samples grew anaerobes where Clostridium species were the predominant isolates. Clostridioides difficile was isolated in 2 samples.ConclusionsAnaerobes in cardiovascular samples are uncommon yet form a significant cause of morbidity and mortality. Most infections are from the contiguous spread, penetrating trauma, and hematogenous causing endocarditis or valvular infections. These conditions and samples form the seat of infectious focus and clinical suspicion towards the anaerobic cause of these conditions, especially in conventional routine culture-negative samples. Timely diagnosis of anaerobic infections plays a vital role in the good prognostic outcome of patients undergoing cardiothoracic and vascular surgery.  相似文献   
35.
European Journal of Clinical Microbiology & Infectious Diseases - Rapid immunochromatographic tests are frequently used to diagnose dengue due to their easy use, low cost, and fast response. A...  相似文献   
36.
Objectives

Air-polishing has been used in the treatment of periodontitis and gingivitis for years. The introduction of low-abrasive powders has enabled the use of air-polishing devices for subgingival therapy. Within the last decade, a wide range of different low-abrasive powders for subgingival use has been established. In this study, the effects of a glycine powder and a trehalose powder on human gingival fibroblasts (HGF) were investigated.

Methods

HGF were derived from three systemically and periodontally healthy donors. After 24 h and 48 h of incubation time, mRNA levels, and after 48 h, protein levels of TNFα, IL-8, CCL2, and VEGF were determined. In addition, NF-κB p65 nuclear translocation and in vitro wound healing were assessed. Statistical analysis was performed by ANOVA and post hoc Dunnett’s and Tukey’s tests (p?<?0.05).

Results

Glycine powder significantly increased the expression of proinflammatory genes and showed exploitation of the NF-κB pathway, albeit trehalose powder hardly interfered with cell function and did not trigger the NF-κB pathway. In contrast to trehalose, glycine showed a significant inhibitory effect on the in vitro wound healing rate.

Conclusion

Subgingivally applicable powders for air-polishing devices can regulate cell viability and proliferation as well as cytokine expression. Our in vitro study suggests that the above powders may influence HGF via direct cell effects. Trehalose appears to be relatively inert compared to glycine powder.

Clinical relevance

With the limitations of an in vitro design, our study suggests that in terms of cell response, trehalose-based air-polishing powders show a reduced effect on inflammation.

  相似文献   
37.
Bulletin of Experimental Biology and Medicine - Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a...  相似文献   
38.
Dumps  C.  Umrath  V.  Rupprecht  B.  Schimpf  J.  Benak  J. 《Der Anaesthesist》2022,71(1):65-82
Die Anaesthesiologie - Durch die Entwicklung von kompakten und mobileren Geräten ist der Einsatz der transösophagealen Echokardiographie (TEE) als Point-of-care-Diagnostikum in...  相似文献   
39.
Cheryl L. Rock PhD  RD  Cynthia A. Thomson PhD  RD  Kristen R. Sullivan MS  MPH  Carol L. Howe MD  MLS  Lawrence H. Kushi ScD  Bette J. Caan DrPH  Marian L. Neuhouser PhD  RD  Elisa V. Bandera MD  PhD  Ying Wang PhD  Kimberly Robien PhD  RD  Karen M. Basen-Engquist PhD  MPH  Justin C. Brown PhD  Kerry S. Courneya PhD  Tracy E. Crane PhD  RDN  David O. Garcia PhD  FACSM  Barbara L. Grant MS  RDN  CSO  FAND  Kathryn K. Hamilton MA  RDN  CSO  CDN  FAND  Sheri J. Hartman PhD  Stacey A. Kenfield ScD  Maria Elena Martinez PhD  Jeffrey A. Meyerhardt MD  MPH  Larissa Nekhlyudov MD  MPH  Linda Overholser MD  Alpa V. Patel PhD  Bernardine M. Pinto PhD  Mary E. Platek PhD  RD  CDN  Erika Rees-Punia PhD  MPH  Colleen K. Spees PhD  MEd  RD  LD  FAND  Susan M. Gapstur PhD  Marjorie L. McCullough ScD  RD 《CA: a cancer journal for clinicians》2022,72(3):230-262
The overall 5-year relative survival rate for all cancers combined is now 68%, and there are over 16.9 million survivors in the United States. Evidence from laboratory and observational studies suggests that factors such as diet, physical activity, and obesity may affect risk for recurrence and overall survival after a cancer diagnosis. The purpose of this American Cancer Society guideline is to provide evidence-based, cancer-specific recommendations for anthropometric parameters, physical activity, diet, and alcohol intake for reducing recurrence and cancer-specific and overall mortality. The audiences for this guideline are health care providers caring for cancer survivors as well as cancer survivors and their families. The guideline is intended to serve as a resource for informing American Cancer Society programs, health policy, and the media. Sources of evidence that form the basis of this guideline are systematic literature reviews, meta-analyses, pooled analyses of cohort studies, and large randomized clinical trials published since 2012. Recommendations for nutrition and physical activity during cancer treatment, informed by current practice, large cancer care organizations, and reviews of other expert bodies, are also presented. To provide additional context for the guidelines, the authors also include information on the relationship between health-related behaviors and comorbidities, long-term sequelae and patient-reported outcomes, and health disparities, with attention to enabling survivors' ability to adhere to recommendations. Approaches to meet survivors' needs are addressed as well as clinical care coordination and resources for nutrition and physical activity counseling after a cancer diagnosis.  相似文献   
40.
European Journal of Clinical Microbiology & Infectious Diseases - Hemorrhagic fever with renal syndrome (HFRS) continues to be a cause of death in Europe. Our aim was to describe the clinical...  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