High rate of relapse to drug using behavior after long period of abstinence cha racterizes the behavior of experienced users of heroin and other drugs of abuse, and the relapse remains the primary problem for treatmen...High rate of relapse to drug using behavior after long period of abstinence cha racterizes the behavior of experienced users of heroin and other drugs of abuse, and the relapse remains the primary problem for treatment. In the present study we built a putative animal model that mimic human relapse i.e., the reinstatement o f morph ine induced conditioned place preference (CPP) in rats. In this study, we found electroacupuncture (EA) with low frequency (2 and 2/100 Hz) could inhibit drug priming or footshock induced CPP reinstatement in rats whe n it was given 18 hours before reinstatement, and these effects were found to be naloxone reversible, suggesting a mechanism involving the activation of opioid receptors by endogenous opioid ligands; while EA with high frequency (100 Hz) h ad no effect. Pr evious studies in our lab have amply shown that low frequency (2 Hz) stimulation could increase the release of enkephalin which acts on μ and δ opioid recepto rs up the spinal level, while high frequency (100 Hz) stimulation could increase the release of dynorphin which interacts with κ opioid receptor at spinal leve l. So we concluded the effect of EA with low frequency on relapse involving a me chanism of the activation of opioid receptors by endogenous opioid ligands above the spinal level. And we suggest that EA may be used as a putative measure for the prevention of relapse to drug use in humans.展开更多
对特殊核材料等进行无损检测时,快中子探测器的时间分辨率对系统的成像时间和图像质量等方面具有重要影响。提高时间分辨率的主要困难在于无法精准测量入射中子与物质相互作用深度(depth of interaction,DOI)。为了减小DOI效应对快中子...对特殊核材料等进行无损检测时,快中子探测器的时间分辨率对系统的成像时间和图像质量等方面具有重要影响。提高时间分辨率的主要困难在于无法精准测量入射中子与物质相互作用深度(depth of interaction,DOI)。为了减小DOI效应对快中子探测的影响,利用Geant4模拟软件构建了基于塑料闪烁体的双端读出快中子探测器模型,系统地研究了闪烁体厚度对探测器时间分辨率性能的影响。在此基础上,提出了平均两端定时和重建中子作用点2种提高时间分辨率的方法。研究结果表明,这2种校准方法均能降低DOI测量不准确对快中子探测产生的影响,提高快中子探测器的时间分辨率。对于厚度为100 mm的闪烁体探测器,利用重建中子作用点法对光电倍增管(photomultiplier tube,PMT)定时补偿后,探测器的时间分辨率由(1030±5)ps提高到(612±2)ps。展开更多
A new large-scale three-dimensional(3D) reconstruction technology based on integral imaging with color-position characteristics is presented.The color of the object point is similar to those of corresponding points.Th...A new large-scale three-dimensional(3D) reconstruction technology based on integral imaging with color-position characteristics is presented.The color of the object point is similar to those of corresponding points.The corresponding point coordinates form arithmetic progressions because integral imaging captures information with a senior array which has similar pitches on x and y directions.This regular relationship is used to determine the corresponding point parameters for reconstructing 3D information from divided elemental images separated by color,which contain several corresponding points.The feasibility of the proposed method is demonstrated through an optical indoor experiment.A large-scale application of the proposed method is illustrated by the experiment with a corner of our school as its object.展开更多
文摘High rate of relapse to drug using behavior after long period of abstinence cha racterizes the behavior of experienced users of heroin and other drugs of abuse, and the relapse remains the primary problem for treatment. In the present study we built a putative animal model that mimic human relapse i.e., the reinstatement o f morph ine induced conditioned place preference (CPP) in rats. In this study, we found electroacupuncture (EA) with low frequency (2 and 2/100 Hz) could inhibit drug priming or footshock induced CPP reinstatement in rats whe n it was given 18 hours before reinstatement, and these effects were found to be naloxone reversible, suggesting a mechanism involving the activation of opioid receptors by endogenous opioid ligands; while EA with high frequency (100 Hz) h ad no effect. Pr evious studies in our lab have amply shown that low frequency (2 Hz) stimulation could increase the release of enkephalin which acts on μ and δ opioid recepto rs up the spinal level, while high frequency (100 Hz) stimulation could increase the release of dynorphin which interacts with κ opioid receptor at spinal leve l. So we concluded the effect of EA with low frequency on relapse involving a me chanism of the activation of opioid receptors by endogenous opioid ligands above the spinal level. And we suggest that EA may be used as a putative measure for the prevention of relapse to drug use in humans.
文摘对特殊核材料等进行无损检测时,快中子探测器的时间分辨率对系统的成像时间和图像质量等方面具有重要影响。提高时间分辨率的主要困难在于无法精准测量入射中子与物质相互作用深度(depth of interaction,DOI)。为了减小DOI效应对快中子探测的影响,利用Geant4模拟软件构建了基于塑料闪烁体的双端读出快中子探测器模型,系统地研究了闪烁体厚度对探测器时间分辨率性能的影响。在此基础上,提出了平均两端定时和重建中子作用点2种提高时间分辨率的方法。研究结果表明,这2种校准方法均能降低DOI测量不准确对快中子探测产生的影响,提高快中子探测器的时间分辨率。对于厚度为100 mm的闪烁体探测器,利用重建中子作用点法对光电倍增管(photomultiplier tube,PMT)定时补偿后,探测器的时间分辨率由(1030±5)ps提高到(612±2)ps。
基金supported by the National Natural Science Foundation of China(No.11474169)
文摘A new large-scale three-dimensional(3D) reconstruction technology based on integral imaging with color-position characteristics is presented.The color of the object point is similar to those of corresponding points.The corresponding point coordinates form arithmetic progressions because integral imaging captures information with a senior array which has similar pitches on x and y directions.This regular relationship is used to determine the corresponding point parameters for reconstructing 3D information from divided elemental images separated by color,which contain several corresponding points.The feasibility of the proposed method is demonstrated through an optical indoor experiment.A large-scale application of the proposed method is illustrated by the experiment with a corner of our school as its object.
