Purpose:Head injury criterion(HIC)companied by a rotation-based metric was widely believed to behelpful for head injury prediction in road traffic accidents.Recently,the Euro-New Car AssessmentProgram utilized a newly...Purpose:Head injury criterion(HIC)companied by a rotation-based metric was widely believed to behelpful for head injury prediction in road traffic accidents.Recently,the Euro-New Car AssessmentProgram utilized a newly developed metric called diffuse axonal multi-axis general evaluation(DAMAGE)to explain test device for human occupant restraint(THOR)head injury,which demonstratedexcellent ability in capturing concussions and diffuse axonal injuries.However,there is still a lack ofcomprehensive understanding regarding the effectiveness of using DAMAGE for Hybrid III 50thpercentile male dummy(H50th)head injury assessment.The objective of this study is to determinewhether the DAMAGE could capture the risk of H50th brain injury during small overlap barrier tests.Methods:To achieve this objective,a total of 24 vehicle crash loading curves were collected as input datafor the multi-body simulation.Two commercially available mathematical dynamic models,namelyH50th and THOR,were utilized to investigate the differences in head injury response.Subsequently,adecision method known as simple additive weighting was employed to establish a comprehensive braininjury metric by incorporating the weighted HIC and either DAMAGE or brain injury criterion.Furthermore,35 sets of vehicle crash test data were used to analyze these brain injury metrics.Results:The rotational displacement of the THOR head is significantly greater than that of the H50thhead.The maximum linear and rotational head accelerations experienced by H50th and THOR modelswere(544.6±341.7)m/s^(2),(2468.2±1309.4)rad/s^(2) and(715.2±332.8)m/s^(2),(3778.7±1660.6)rad/s^(2),respectively.Under the same loading condition during small overlap barrier(SOB)tests,THOR exhibits ahigher risk of head injury compared to the H50th model.It was observed that the overall head injuryresponse during the small overlap left test condition is greater than that during the small overlap righttest.Additionally,an equation was formulated to establish the necessary relationship between theDAMAGE values of THOR and H50th.Conclusion:If H50th rather than THOR is employed as an evaluation tool in SOB crash tests,newlydesigned vehicles are more likely to achieve superior performance scores.According to the current injurycurve for DAMAGE and brain injury criterion,it is highly recommended that HIC along with DAMAGE wasprioritized for brain injury assessment in SOB tests.展开更多
Helicobacter pylori(H.pylori)infection is very common and affects a significant proportion of the world population.In contrast,the prevalence of small intestinal bacterial overgrowth(SIBO)in the general population is ...Helicobacter pylori(H.pylori)infection is very common and affects a significant proportion of the world population.In contrast,the prevalence of small intestinal bacterial overgrowth(SIBO)in the general population is not well understood.There can be coexistence of both disease states in a given patient and their clinical symptoms may also overlap with one and another.There is no clear clinical guidelines for testing for and treating SIBO in patients with H.pylori infection.This review article explores the available evidence on the relationship between H.pylori infection and SIBO,diagnosis and treatment of these entities and also comments on associated non-gastrointestinal conditions.展开更多
美国高速公路安全保险协会(Insurance Institute for Highway Safety,IIHS)2012年颁布的正面小重叠碰撞试验方法及评价规程,对进军美国市场的中国车企提出了挑战。本文根据IIHS协会的试验方法及评价规程,用相关性分析后的有限元模型,对...美国高速公路安全保险协会(Insurance Institute for Highway Safety,IIHS)2012年颁布的正面小重叠碰撞试验方法及评价规程,对进军美国市场的中国车企提出了挑战。本文根据IIHS协会的试验方法及评价规程,用相关性分析后的有限元模型,对某实车进行了正面小重叠碰撞仿真分析。试验中,汽车以64.4km/h的速度撞击刚性壁障,重叠率为25%。试验后对碰撞车的车体结构、约束系统/假人运动学、假人伤害测量三方面进行评价,加权得到正面小重叠碰撞工况的总等级。分析结果为:车体结构得到"边缘"的评级;针对初始结果,从车体结构和材料两方面进行优化,优化后车体结构评级为"良好"。提出结构耐撞性能、约束系统集成方面的建议,为后续车辆安全性能开发提供参考。展开更多
基金This work has been supported by the National Natural ScienceFoundation of China(Grant No.32171305)Natural Science Foundation of Chongqing,China(Grant No.cstc2021jcyj-msxmX0109)Chongqing Technology Innovation and Application Development Project(Grant No.CSTB2023YSZX-JSX0003).
文摘Purpose:Head injury criterion(HIC)companied by a rotation-based metric was widely believed to behelpful for head injury prediction in road traffic accidents.Recently,the Euro-New Car AssessmentProgram utilized a newly developed metric called diffuse axonal multi-axis general evaluation(DAMAGE)to explain test device for human occupant restraint(THOR)head injury,which demonstratedexcellent ability in capturing concussions and diffuse axonal injuries.However,there is still a lack ofcomprehensive understanding regarding the effectiveness of using DAMAGE for Hybrid III 50thpercentile male dummy(H50th)head injury assessment.The objective of this study is to determinewhether the DAMAGE could capture the risk of H50th brain injury during small overlap barrier tests.Methods:To achieve this objective,a total of 24 vehicle crash loading curves were collected as input datafor the multi-body simulation.Two commercially available mathematical dynamic models,namelyH50th and THOR,were utilized to investigate the differences in head injury response.Subsequently,adecision method known as simple additive weighting was employed to establish a comprehensive braininjury metric by incorporating the weighted HIC and either DAMAGE or brain injury criterion.Furthermore,35 sets of vehicle crash test data were used to analyze these brain injury metrics.Results:The rotational displacement of the THOR head is significantly greater than that of the H50thhead.The maximum linear and rotational head accelerations experienced by H50th and THOR modelswere(544.6±341.7)m/s^(2),(2468.2±1309.4)rad/s^(2) and(715.2±332.8)m/s^(2),(3778.7±1660.6)rad/s^(2),respectively.Under the same loading condition during small overlap barrier(SOB)tests,THOR exhibits ahigher risk of head injury compared to the H50th model.It was observed that the overall head injuryresponse during the small overlap left test condition is greater than that during the small overlap righttest.Additionally,an equation was formulated to establish the necessary relationship between theDAMAGE values of THOR and H50th.Conclusion:If H50th rather than THOR is employed as an evaluation tool in SOB crash tests,newlydesigned vehicles are more likely to achieve superior performance scores.According to the current injurycurve for DAMAGE and brain injury criterion,it is highly recommended that HIC along with DAMAGE wasprioritized for brain injury assessment in SOB tests.
文摘Helicobacter pylori(H.pylori)infection is very common and affects a significant proportion of the world population.In contrast,the prevalence of small intestinal bacterial overgrowth(SIBO)in the general population is not well understood.There can be coexistence of both disease states in a given patient and their clinical symptoms may also overlap with one and another.There is no clear clinical guidelines for testing for and treating SIBO in patients with H.pylori infection.This review article explores the available evidence on the relationship between H.pylori infection and SIBO,diagnosis and treatment of these entities and also comments on associated non-gastrointestinal conditions.
文摘美国高速公路安全保险协会(Insurance Institute for Highway Safety,IIHS)2012年颁布的正面小重叠碰撞试验方法及评价规程,对进军美国市场的中国车企提出了挑战。本文根据IIHS协会的试验方法及评价规程,用相关性分析后的有限元模型,对某实车进行了正面小重叠碰撞仿真分析。试验中,汽车以64.4km/h的速度撞击刚性壁障,重叠率为25%。试验后对碰撞车的车体结构、约束系统/假人运动学、假人伤害测量三方面进行评价,加权得到正面小重叠碰撞工况的总等级。分析结果为:车体结构得到"边缘"的评级;针对初始结果,从车体结构和材料两方面进行优化,优化后车体结构评级为"良好"。提出结构耐撞性能、约束系统集成方面的建议,为后续车辆安全性能开发提供参考。
