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   24806篇
  免费   1669篇
  国内免费   135篇
耳鼻咽喉   260篇
儿科学   705篇
妇产科学   657篇
基础医学   3816篇
口腔科学   422篇
临床医学   2029篇
内科学   6088篇
皮肤病学   658篇
神经病学   2661篇
特种医学   634篇
外科学   2545篇
综合类   89篇
一般理论   11篇
预防医学   1747篇
眼科学   491篇
药学   1724篇
中国医学   58篇
肿瘤学   2015篇
  2023年   269篇
  2022年   222篇
  2021年   899篇
  2020年   547篇
  2019年   827篇
  2018年   875篇
  2017年   677篇
  2016年   750篇
  2015年   813篇
  2014年   1108篇
  2013年   1315篇
  2012年   1991篇
  2011年   2069篇
  2010年   1164篇
  2009年   1019篇
  2008年   1595篇
  2007年   1663篇
  2006年   1534篇
  2005年   1449篇
  2004年   1242篇
  2003年   1130篇
  2002年   976篇
  2001年   219篇
  2000年   221篇
  1999年   211篇
  1998年   154篇
  1997年   113篇
  1996年   79篇
  1995年   102篇
  1994年   73篇
  1993年   71篇
  1992年   127篇
  1991年   124篇
  1990年   113篇
  1989年   94篇
  1988年   94篇
  1987年   93篇
  1986年   76篇
  1985年   67篇
  1984年   40篇
  1983年   46篇
  1982年   31篇
  1981年   27篇
  1980年   29篇
  1979年   22篇
  1978年   20篇
  1974年   24篇
  1973年   20篇
  1971年   18篇
  1970年   18篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
ObjectiveThe aim of this study was to create and validate an abbreviated version of the Spanish Transsexual Voice Questionnaire for Male-to-Female Transsexuals (SvTVQMtF).SettingThe study was conducted by two referral hospitals for voice feminization surgery and by a university department of psychology and speech therapy, all in Spain.Subjects and methodsWe prospectively studied 51 male-to-female transsexuals who underwent voice feminization surgery between January 2017 and December 2018. The SvTVQMtF was completed before and after surgery, and the 10 items with the greatest variation were selected by clinical consensus of an expert panel to develop the short version of the SvTVQMtF (SvTVQMtF-10). The correlation between the total score and the score for each item on the SvTVQMtF and the SvTVQMtF-10 was studied. The internal consistency of the SvTVQMtF-10 was analysed.ResultsGood correlation (Pearson coefficient above .90) was found between the two questionnaires. A significant correlation was found between the total SvTVQMtF-10 score and the score for each item. A significant negative correlation was found between the SvTVQMtF and fundamental frequency after voice feminization surgery. Cronbach's α was .79.ConclusionThe SvTVQMtF-10 is a valid short version of the SvTVQMtF and can be used to quantify voice-related quality of life in MtF transsexuals.  相似文献   
4.
The mechanisms linking tumor microenvironment acidosis to disease progression are not understood. Here, we used mammary, pancreatic, and colon cancer cells to show that adaptation to growth at an extracellular pH (pHe) mimicking acidic tumor niches is associated with upregulated net acid extrusion capacity and elevated intracellular pH at physiological pHe, but not at acidic pHe. Using metabolic profiling, shotgun lipidomics, imaging and biochemical analyses, we show that the acid adaptation-induced phenotype is characterized by a shift toward oxidative metabolism, increased lipid droplet-, triacylglycerol-, peroxisome content and mitochondrial hyperfusion. Peroxisome proliferator-activated receptor-α (PPARA, PPARα) expression and activity are upregulated, at least in part by increased fatty acid uptake. PPARα upregulates genes driving increased mitochondrial and peroxisomal mass and β-oxidation capacity, including mitochondrial lipid import proteins CPT1A, CPT2 and SLC25A20, electron transport chain components, peroxisomal proteins PEX11A and ACOX1, and thioredoxin-interacting protein (TXNIP), a negative regulator of glycolysis. This endows acid-adapted cancer cells with increased capacity for utilizing fatty acids for metabolic needs, while limiting glycolysis. As a consequence, the acid-adapted cells exhibit increased sensitivity to PPARα inhibition. We conclude that PPARα is a key upstream regulator of metabolic changes favoring cancer cell survival in acidic tumor niches.  相似文献   
5.
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   
6.
7.
8.
Network meta-analyses (NMAs) simultaneously estimate the effects of multiple possible treatment options for a given clinical presentation. For allergists to benefit optimally from NMAs, they must understand the process and be able to interpret the results. Through a worked example published in Pediatric Allergy and Immunology, we summarize how to identify credible NMAs and interpret them with a focus on recent innovations in the GRADE approach (Grading of Recommendations Assessment, Development, and Evaluation). NMAs build on traditional systematic reviews and meta-analyses that consider only direct paired comparisons by including indirect evidence, thus allowing the simultaneous assessment of the relative effect of all pairs of competing alternatives. Our framework informs clinicians of how to identify credible NMAs and address the certainty of the evidence. Trustworthy NMAs fill a critical gap in providing key inferences using direct and indirect evidence to inform clinical decision making when faced with more than two competing courses of treatment options. This document will help allergists to identify trustworthy NMAs to enhance patient care.  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