The lack of truly robust analgesics for chronic pain is owed,in part,to the lack of an animal model that reflects the clinical pain state and of a mechanismbased,objective neurological indicator of pain.The present st...The lack of truly robust analgesics for chronic pain is owed,in part,to the lack of an animal model that reflects the clinical pain state and of a mechanismbased,objective neurological indicator of pain.The present study examined stimulus-evo ked brain activation with functional magnetic resonance imaging in male and female cynomolgus macaques following unilateral L7 spinal nerve ligation and the effects of clinical analgesics pregabalin,duloxetine,and morphine on brain activation in these macaques.A modified straight leg raise test was used to assess pain severity in awake animals and to evo ke regional brain activation in anesthetized animals.The potential effects of clinical analgesics on both awake pain behavior and regional brain activation were examined.Following spinal nerve ligation,both male and female macaques showed significantly decreased ipsilateral straight leg raise thresholds,suggesting the presence of radicula rlike pain.Morphine treatment increased straight leg raise thresholds in both males and females whereas duloxetine and pregabalin did not.In male macaques,the ipsilateral straight leg raise activated contralateral insular and somatosensory cortex(Ins/SII),and thalamus.In female macaques,the ipsilateral leg raise activated cingulate cortex and contralateral insular and somatosensory cortex.Straight leg raises of the contralateral,unligated leg did not evoke brain activation.Morphine reduced activation in all brain regions in both male and female macaques.In males,neither pregabalin nor duloxetine decreased brain activation compared with vehicle treatment.In females,however,pregabalin and duloxetine decreased the activation of cingulate cortex compared with vehicle treatment.The current findings suggest a diffe rential activation of brain areas depending on sex following a peripheral nerve injury.Diffe rential brain activation observed in this study could underlie qualitative sexual dimorphism in clinical chronic pain perception and responses to analgesics.Future pain management approaches for neuropathic pain will need to consider potential sex differences in pain mechanism and treatment efficacy.展开更多
The assessment of activated concrete is particularly difficult during the decommissioning of an accelerator facility.Destructive analysis by core boring is the only method of investigating the activity of concrete mat...The assessment of activated concrete is particularly difficult during the decommissioning of an accelerator facility.Destructive analysis by core boring is the only method of investigating the activity of concrete material.To address this problem,an in-situ and nondestructive analysis method was developed to determineγ-ray-emitting nuclides and their specific activities in the concrete walls and floor by using a portable germanium semiconductor detector.In this work,we examined a substitute for Ge detector to establish a simpler and more convenient method.As candidates,we focused on some scintillation type spectrometers,and the possibility of a substitute for a Ge detector was examined by both simulation and experiment.The detection limits were roughly estimated through Monte Carlo simulation for various scintillation crystals,and it was found that 1.5-inch LaBr3,CeBr3,and SrI2 could distinguish the clearance level.It was confirmed that the 1.5-inch LaBr3 could reproduce the calibration curve of the Ge detector in the experiment.The required thickness and length of the radiation shield for suppressing the background radiation during the measurement was also determined for the convenience of an actual decommissioning work.展开更多
This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of a...This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an accelerator.We propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation zoning.In this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron flux.The obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated concrete.This method is a powerful long-term prediction tool for concrete activation.展开更多
文摘The lack of truly robust analgesics for chronic pain is owed,in part,to the lack of an animal model that reflects the clinical pain state and of a mechanismbased,objective neurological indicator of pain.The present study examined stimulus-evo ked brain activation with functional magnetic resonance imaging in male and female cynomolgus macaques following unilateral L7 spinal nerve ligation and the effects of clinical analgesics pregabalin,duloxetine,and morphine on brain activation in these macaques.A modified straight leg raise test was used to assess pain severity in awake animals and to evo ke regional brain activation in anesthetized animals.The potential effects of clinical analgesics on both awake pain behavior and regional brain activation were examined.Following spinal nerve ligation,both male and female macaques showed significantly decreased ipsilateral straight leg raise thresholds,suggesting the presence of radicula rlike pain.Morphine treatment increased straight leg raise thresholds in both males and females whereas duloxetine and pregabalin did not.In male macaques,the ipsilateral straight leg raise activated contralateral insular and somatosensory cortex(Ins/SII),and thalamus.In female macaques,the ipsilateral leg raise activated cingulate cortex and contralateral insular and somatosensory cortex.Straight leg raises of the contralateral,unligated leg did not evoke brain activation.Morphine reduced activation in all brain regions in both male and female macaques.In males,neither pregabalin nor duloxetine decreased brain activation compared with vehicle treatment.In females,however,pregabalin and duloxetine decreased the activation of cingulate cortex compared with vehicle treatment.The current findings suggest a diffe rential activation of brain areas depending on sex following a peripheral nerve injury.Diffe rential brain activation observed in this study could underlie qualitative sexual dimorphism in clinical chronic pain perception and responses to analgesics.Future pain management approaches for neuropathic pain will need to consider potential sex differences in pain mechanism and treatment efficacy.
文摘The assessment of activated concrete is particularly difficult during the decommissioning of an accelerator facility.Destructive analysis by core boring is the only method of investigating the activity of concrete material.To address this problem,an in-situ and nondestructive analysis method was developed to determineγ-ray-emitting nuclides and their specific activities in the concrete walls and floor by using a portable germanium semiconductor detector.In this work,we examined a substitute for Ge detector to establish a simpler and more convenient method.As candidates,we focused on some scintillation type spectrometers,and the possibility of a substitute for a Ge detector was examined by both simulation and experiment.The detection limits were roughly estimated through Monte Carlo simulation for various scintillation crystals,and it was found that 1.5-inch LaBr3,CeBr3,and SrI2 could distinguish the clearance level.It was confirmed that the 1.5-inch LaBr3 could reproduce the calibration curve of the Ge detector in the experiment.The required thickness and length of the radiation shield for suppressing the background radiation during the measurement was also determined for the convenience of an actual decommissioning work.
文摘This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an accelerator.We propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation zoning.In this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron flux.The obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated concrete.This method is a powerful long-term prediction tool for concrete activation.
