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   230292篇
  免费   7065篇
  国内免费   986篇
耳鼻咽喉   3140篇
儿科学   8479篇
妇产科学   6492篇
基础医学   30301篇
口腔科学   6358篇
临床医学   18565篇
内科学   42478篇
皮肤病学   5297篇
神经病学   14265篇
特种医学   11949篇
外国民族医学   114篇
外科学   33441篇
综合类   2690篇
现状与发展   2篇
一般理论   3篇
预防医学   19149篇
眼科学   5048篇
药学   16319篇
  9篇
中国医学   842篇
肿瘤学   13402篇
  2022年   929篇
  2021年   1388篇
  2020年   942篇
  2019年   1095篇
  2018年   4647篇
  2017年   4712篇
  2016年   4003篇
  2015年   5839篇
  2014年   5528篇
  2013年   4999篇
  2012年   12091篇
  2011年   7018篇
  2010年   3593篇
  2009年   4993篇
  2008年   3732篇
  2007年   4479篇
  2006年   4667篇
  2005年   12715篇
  2004年   13956篇
  2003年   9481篇
  2002年   4645篇
  2001年   5503篇
  2000年   2855篇
  1999年   6847篇
  1992年   7401篇
  1991年   7616篇
  1990年   7811篇
  1989年   7366篇
  1988年   6926篇
  1987年   6610篇
  1986年   6325篇
  1985年   5596篇
  1984年   3839篇
  1983年   3087篇
  1982年   1119篇
  1979年   4030篇
  1978年   2470篇
  1977年   1904篇
  1976年   1672篇
  1975年   2569篇
  1974年   3234篇
  1973年   2833篇
  1972年   2880篇
  1971年   2814篇
  1970年   2649篇
  1969年   2567篇
  1968年   2323篇
  1967年   2228篇
  1966年   1957篇
  1965年   1179篇
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
1.
2.
3.
European Radiology - The strongest adverse prognostic factor in myxoid/round cell liposarcomas (MRC-LPS) is the presence of a round cell component above 5% within the tumor bulk. Its identification...  相似文献   
4.
Introduction: The treatment of classical Hodgkin lymphoma (cHL) in children is a story of success. Nowadays, more than 90% of patients are cured and overall survival is nearly 100% at 5 years. Efforts have been made to avoid related effects of therapies; therefore, children are treated using different chemotherapy schemes in comparison with adults.

Areas covered: This review includes a view of the clinical classification and risk assessment in children suffering from HL. The chemotherapy more commonly employed is revisited. The use of PET/CT to evaluate the disease in order to guide therapy is analyzed. New options of chemotherapy and emerging immunotherapy are also included.

Expert opinion: In order to make the right treatment choice, a proper initial assessment of risk is mandatory. The choice of therapy in these kinds of patients must be done according to the experience of the team, and also, the cost and logistics related to the eligible scheme are very important. If possible, efforts must be made to include PET/CT in guiding therapy and avoiding overtreatment and long-term adverse effects in children. New options in immunotherapy are emerging and must be considered with caution in selected patients.  相似文献   

5.
6.
7.
8.
目的:探讨miR-26b参与原发性肝细胞肝癌(HCC)侵袭的机制。方法:在细胞培养液中培养人肝细胞系HL-7702和HCC细胞各系Hepb-3、HuH-7、MHCC97-L、MHCC97-H。实时荧光定量PCR法(qRT-PCR)检测miR-26b的表达水平;用miR-26b mimics、miR-26b inhibitors和Notch1-siRNA分别转染HCC细胞;MTT实验检测转染后HCC细胞的活力;采用Western blot检测Notch1受体蛋白表达水平的变化;Transwell小室测定不同处理后的HCC细胞的侵袭能力。结果:人正常肝细胞系HL-7702和HCC细胞系Hepb-3、HuH-7、MHCC97-L、MHCC97-H中的miR-26b相对表达含量随其侵袭和迁移能力的升高而依次下降;抑制miR-26b的表达,Notch1受体蛋白表达明显增高,而此时HCC细胞的侵袭性显著增强;相反,上调miR-26b的表达,Notch1受体蛋白表达明显降低,而HCC细胞侵袭性显著下降;miR-26b可能通过调控Notch1信号通路调节HCC细胞侵袭性。结论:miR-26b通过负调控Notch1信号通路抑制HCC细胞侵袭能力,为HCC侵袭的机制奠定了理论基础,miR-26b可能成为HCC治疗的新靶点。  相似文献   
9.
10.
Attachment is a behavioral and physiological system, which enables individual’s dynamic adaptation to its environment. Attachment develops in close interaction between an infant and his/her mother, plays an important role in the development of the infant’s brain, and influences the quality of interpersonal relationships throughout life.Security of attachment is believed to influence individual response to stress, exposing insecurely organized individuals to deregulated autonomic nervous system and exaggerated hypothalamic-pituitary-adrenal activity, which, in turn, produces increased and prolonged exposure to stress-hormones. Such stress responses may have considerable implications for the development of diverse health-risk conditions, such as insulin resistance and hyperlipidemia, shown by numerous studies.Although the mechanisms are not yet fully understood, there is compelling evidence highlighting the role of psychological stress in the development of type 1 diabetes (T1D). One of the possible contributing factors for the development of T1D may be the influence of attachment security on individual stress reactivity. Thus, the suggestion is that insecurely attached individuals are more prone to experience increased and prolonged influence of stress hormones and other mechanisms causing pancreatic beta-cell destruction.The present paper opens with a short overview of the field of attachment in children, the principal attachment classifications and their historic development, describes the influence of attachment security on individual stress-reactivity and the role of the latter in the development of T1D. Following is a review of recent literature on the attachment in patients with T1D with a conclusion of a proposed role of attachment organization in the etiology of T1D.  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