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   653篇
  免费   50篇
  国内免费   54篇
耳鼻咽喉   2篇
儿科学   21篇
妇产科学   11篇
基础医学   48篇
口腔科学   11篇
临床医学   60篇
内科学   56篇
皮肤病学   17篇
神经病学   61篇
特种医学   26篇
外科学   105篇
综合类   67篇
预防医学   10篇
眼科学   23篇
药学   117篇
中国医学   103篇
肿瘤学   19篇
  2024年   2篇
  2023年   37篇
  2022年   33篇
  2021年   47篇
  2020年   40篇
  2019年   34篇
  2018年   31篇
  2017年   41篇
  2016年   30篇
  2015年   41篇
  2014年   48篇
  2013年   65篇
  2012年   42篇
  2011年   44篇
  2010年   31篇
  2009年   29篇
  2008年   22篇
  2007年   20篇
  2006年   22篇
  2005年   19篇
  2004年   14篇
  2003年   9篇
  2002年   10篇
  2001年   4篇
  2000年   4篇
  1999年   4篇
  1998年   9篇
  1997年   9篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   3篇
排序方式: 共有757条查询结果,搜索用时 31 毫秒
1.
2.
作为术中导航的新兴领域,近红外荧光(near-infrared fluorescence,NIRF)成像技术能借助荧光探针对特定的生物组织进行显像,从而在外科手术中实时获取血管、淋巴管和特定组织的视觉信息,从而发现传统方法无法识别的微小灶,正确显示肿瘤切缘,帮助外科医生进行术中决策。该技术由于其操作简单,快速实时,安全无害,具有良好的应用前景。本文将就NIRF成像技术的基本原理,在实时引导肿瘤切除,前哨淋巴结定位,保护正常解剖结构等方面的临床进展进行综述,并且讨论了该技术的局限性和优势并展望其应用前景。  相似文献   
3.
《临床与病理杂志》2021,(4):928-933
颈内静脉球血氧饱和度(jugular venous bulb oxygen saturation,SjvO2)监测可及早发现脑氧供需的变化,尽早治疗以减轻脑组织的缺血缺氧性损伤。在神经外科手术、体外循环(cardiopulmonary bypass,CPB)和特殊体位手术中应用广泛,与脑组织氧分压(partial oxygen pressure of brain tissue,PbtO2)和近红外光谱对比有其优势,还可用于围手术期生理探索、指导过度通气、综合脑保护和多模式监测等诊治手段。  相似文献   
4.
High Temperamental Negative Affectivity in early childhood has been found to predict later emotion dysregulation. While much work has been conducted to separately probe bio-behavioral systems associated with Negative Affectivity, very little work has examined the relations among multiple systems across age. In this study, we use multi-modal methods to index neurobiological systems associated with Negative Affectivity in 53 4-7-year-old children. Prefrontal activation during emotion regulation was measured using functional near-infrared spectroscopy over the lateral prefrontal cortex (PFC) while children played a game designed to elicit frustration in Social (Happy and Angry faces) and Nonsocial contexts. Gaze behaviors while free-viewing Happy and Angry faces were also measured. Finally, Negative Affectivity was indexed using a score composite based on factor analysis of parent-reported temperament. Using mixed-effects linear models, we found an age-dependent association between Negative Affectivity and both PFC activation during frustration and fixation duration on the mouth area of Happy faces, such that older children high in Negative Affectivity spent less time looking at the mouths of Happy faces and had lower PFC activation in response to frustration (ps<0.034). These results provide further insight to how Negative Affectivity may be associated with changes in affective neurobiological systems across early childhood.  相似文献   
5.
Diffuse correlation spectroscopy (DCS) can non-invasively and continuously asses regional cerebral blood flow (rCBF) at the cot-side by measuring a blood flow index (BFI) in non-traditional units of cm2/s. We have validated DCS against positron emission tomography using 15O-labeled water (15O-water PET) in a piglet model allowing us to derive a conversion formula for BFI to rCBF in conventional units (ml/100g/min). Neonatal piglets were continuously monitored by the BabyLux device integrating DCS and time resolved near infrared spectroscopy (TRS) while acquiring 15O-water PET scans at baseline, after injection of acetazolamide and during induced hypoxic episodes. BFI by DCS was highly correlated with rCBF (R = 0.94, p < 0.001) by PET. A scaling factor of 0.89 (limits of agreement for individual measurement: 0.56, 1.39)×109× (ml/100g/min)/(cm2/s) was used to derive baseline rCBF from baseline BFI measurements of another group of piglets and of healthy newborn infants showing an agreement with expected values. These results pave the way towards non-invasive, cot-side absolute CBF measurements by DCS on neonates.  相似文献   
6.
7.
8.
近红外脑功能成像技术是近几年发展起来用于动态检测脑功能的方法,能够很好地反映抑郁人群认知活动期间大脑有氧代谢的变化,为阈下抑郁研究提供了一个新思路。本研究通过文献综述,结合中医情志理论,在过往研究的基础上基于近红外脑功能成像技术探讨中医情志刺激对阈下抑郁的反应机制,为后期研究提供理论与实践可行性的依据。  相似文献   
9.
《Vaccine》2021,39(46):6805-6812
Adjuvants are essential for ensuring the efficacy of modern vaccines. Considering frequent local and systemic adverse reactions, research into the development of safer and more effective adjuvants is being actively conducted. In recent years, the novel concept of laser vaccine adjuvants, which use the physical energy of light, has been developed. For long, light has been known to affect the physiological functions in living organisms. Since the development of lasers as stable light sources, laser adjuvants have evolved explosively in multiple ways over recent decades. Future laser adjuvants would have the potential not only to enhance the efficacy of conventional vaccine preparations but also to salvage candidate vaccines abandoned during development because of insufficient immunogenicity or owing to their inability to be combined with conventional adjuvants. Furthermore, the safety and efficacy of non-invasive laser adjuvants make them advantageous for vaccine dose sparing, which would be favorable for the timely and equitable global distribution of vaccines. In this review, we first describe the basics of light–tissue interactions, and then summarize the classification of lasers, the history of laser adjuvants, and the mechanisms by which different lasers elicit an immune response.  相似文献   
10.
比较宁夏乌拉尔甘草(以下均简称甘草)中基于指标成分含量的色谱鉴别和基于近红外光谱的光谱鉴别差异,建立快速有效鉴别宁夏野生和栽培甘草的方法。采用HPLC和紫外光谱法测定9批野生甘草和14批栽培甘草中甘草苷、甘草酸和总黄酮的含量并采集其近红外光谱信息。结果显示,基于指标成分定量的色谱鉴别无法有效鉴别宁夏野生和栽培甘草,近红外光谱结合聚类分析和主成分分析能够直观、快速、有效鉴别宁夏野生和栽培甘草样品,为甘草生长方式的鉴别及应用研究提供有效方法。同时,为甘草的品种、产地及规格等方面的鉴别提供了研究思路。  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