Accidents involving pedestrians with their backs to traffic or facing traffic: an evaluation of crash characteristics and injuries

This paper examines pedestrian anatomical injuries and crash characteristics in back‐to‐traffic and facing‐traffic crashes. Pedestrian crashes involving pedestrians walking along streets (i.e. with their backs to traffic or facing traffic) have been overlooked in literature. Although this is not the most frequent type of crash, the crash consequence to pedestrians is a safety concern. Combining Taiwan A1A2 police‐reported accident data and data from the National Health Insurance Database from years 2003–2013, this paper examines anatomical injuries and crash characteristics in back‐to‐traffic and facing‐traffic crashes. There were a total of 830 and 2267 pedestrian casualties in back‐to‐traffic and facing‐traffic crashes respectively. The injuries sustained by pedestrians and crash characteristics of these two crash types were compared with those of other crossing types of crashes (nearside crash, nearside dart‐out crash, offside crash, and offside dart‐out crash). Odds of various injuries to body regions were estimated using logistic regressions. Key findings include that the percentage of fatalities in back‐to‐traffic crashes is the highest; logistic models reveal that pedestrians in back‐to‐traffic crashes sustained more head, neck, and spinal injuries than did pedestrians in other crash types, and unlit darkness and non‐built‐up roadways were associated with an increased risk of pedestrian head injuries. Several crash features (e.g. unlit darkness, overtaking manoeuvres, phone use by pedestrians and drivers, and intoxicated drivers) are more frequently evident in back‐to‐traffic crashes than in other types of crashes. The current research suggests that in terms of crash consequence, facing traffic is safer than back to traffic. Copyright © 2016 John Wiley & Sons, Ltd.     

建成环境对老年人交通事故严重程度异质性影响

为量化建成环境因素对事故伤害严重程度的影响,本文构建基于均值和方差异质性的随机参数Logit模型对老年人交通事故伤害严重程度进行异质性分析。采用2019年美国某州老年人交通事故数据,从老年人特性、车辆特性、道路特性、道路环境特性、建成环境特性这5个方面选取17个影响因素,利用平均弹性系数捕捉各因素对事故伤害严重程度的影响。结果表明：基于均值和方差异质性随机参数Logit模型的拟合优度更高;建成环境因素中事故发生地300 m缓冲区 内存在购物中心为随机变量,其均值与男性老年人、车道数为3显著相关,方差与道路控制方式为未控制显著相关;摩托车、直线、湿润等因素显著增加了老年人交通事故伤害严重程度。研究结果有助于交通管理者采取适当的策略降低老年人交通事故伤害严重程度。     

弥漫性轴索损伤后继发性脑损伤与神经保护治疗的研究进展

弥漫性轴索损伤(diffuse axonal injury,DAI)是一个进行性的病理生理变化,主要的脑损伤发生于继发性损伤(secondary injury,SI)阶段。因此,SI是影响患者病情及预后的重要因素。目前,有关SI病理机制的研究表明,DAI后神经元的SI涉及神经元及轴膜的离子平衡紊乱、沃勒变性、轴膜通透性改变、线粒体损伤及能量代谢障碍、免疫炎症反应以及氧化应激损伤等多种损伤机制。这些SI机制相互作用相互影响,是最终导致DAI后神经元变性、甚至坏死和凋亡以及轴突继发性断裂的关键原因。虽然临床上对DAI患者的治疗目前无突破性进展,仍采用一般性治疗、亚低温以及神经营养等手段。但新近研究显示,有一些动物的体内或体外实验为DAI后的SI提供了潜在的治疗靶点,如钙离子拮抗剂、轴膜保护及修复药物、钙依赖的蛋白水解酶抑制剂、氧化应激抑制剂以及免疫抑制剂等。进一步阐明DAI后钙离子平衡紊乱、轴浆运输中断、线粒体损伤及能量代谢障碍、免疫炎症反应等SI的相关分子机制,以及这些多因素导致的DAI病理机制相互间的关系,将对减轻或阻断DAI后发生SI,加强神经保护与修复,以及为未来突破DAI的治疗瓶颈均具有重要意义。     

辛伐他汀在弥漫性轴索损伤后神经保护中的作用及其机制

目的探索辛伐他汀预处理在弥漫性轴索损伤(DAI)后神经保护中的作用,并初步阐明可能的机制。方法采用大鼠头颅瞬间旋转损伤装置制备大鼠DAI模型,模型制作前随机给予白开水或辛伐他汀[60mg/(kg·d)]灌胃1周,DAI后24h用改良神经功能缺损程度评分(mNSS)评估神经功能状态,处死并取脑,脑组织切片行HE染色、Mallory磷钨酸苏木素染色、淀粉样蛋白前体(APP)免疫组化染色及TUNEL染色,另外大鼠用于提取脑组织蛋白行RhoA活性检测。结果 DAI后大鼠都出现明显神经功能缺失,组织病理学可见神经元死亡,轴突断裂。辛伐他汀预处理后神经功能有明显改善,APP分数明显降低,TUNEL染色强度也有降低。RhoA活性检测结果显示DAI后RhoA活性升高,但此效应可被辛伐他汀抑制。相关性分析显示RhoA活性与APP分数及TUNEL结果都有显著相关性。实验前后大鼠的生理指标和血液生化指标无明显差异。结论辛伐他汀可改善DAI后神经功能状态,且此作用与抑制RhoA活性有关。     

DAPK1在弥漫性轴索损伤后大鼠脑组织中的表达及其与神经元凋亡的关系

目的探讨大鼠弥漫性轴索损伤(diffuse axonal injury,DAI)后神经元凋亡及死亡相关蛋白激酶1(DAPK1)表达变化,为临床治疗提供新的靶点及治疗时间窗。方法 40只SD成年雄性大鼠随机分为对照组(n=8)和DAI组(n=32)。DAI组选用大鼠头颅瞬间旋转装置制备DAI模型,分为6h、24h、72h、7d组共4个亚组(n=8)。各组在造模前及处死前采用改良神经功能缺损评分(mNSS)对大鼠神经功能进行评分;同时将各组大鼠一半用于Western bolt检测大鼠胼胝体、脑干组织内DAPK1表达情况;另一半用于TUNEL检测大鼠脑组织内神经元细胞凋亡情况。结果 DAI后大鼠均出现明显体质量下降、神经功能缺失;DAI后6h组大鼠胼胝体、脑干组织可见DAPK1蛋白表达明显升高,并出现明显神经元细胞凋亡,DAI后24h组DAPK1表达及神经元细胞凋亡均到达高峰值,DAI后72h、7d组表达开始下降,仍明显高于对照组。结论 DAI后出现神经功能缺失、体质量下降,可能与损伤后DAPK1表达及神经元细胞凋亡有关,二者在损伤后24h一致性达到高峰;提示DAPK1抑制剂药物治疗时间窗为伤后24h。     

汽车碰撞过程中加速度特征对乘员损伤的影响分析

针对汽车正面碰撞过程中车身压溃失稳产生初始加速度峰值的特点,提取基本特征,改变峰值大小,构造加速度曲线组,研究峰值变化对乘员安全性的影响。研究表明,车身加速度峰值处于较小范围时,人体综合损伤指标对峰值的变化并不敏感。     

黄芪预处理对大鼠心肌缺血再灌注损伤的保护作用及其机制

目的 探讨黄芪对大鼠缺血再灌注心肌的保护作用及其机制.方法 采用结扎左冠状动脉的方法制备心肌缺血再灌注损伤动物模型.SD大鼠30只随机分为3组:对照组、缺血再灌注组(I/R)和黄芪预处理组(H+I/R).光镜和透射电镜下观察心肌病理变化,检测血清肌酸激酶(CK)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,以及心肌组织Na~+K~+-ATP酶(Na~+K~+-ATPase)、Ca~(2+)-ATP酶(Ca~(2+)-ATPase)活性.结果 ①黄芪预处理组光镜和透射电镜下心肌细胞变性坏死程度及心肌细胞超微结构形态改变较缺血再灌注组显著减轻;②黄芪预处理组大鼠血清中CK、LDH活性和MDA含量显著降低(P<0.05),SOD、Na+ K+-ATPase、Ca~(2+)-ATPase活性显著提高(P<0.05).结论 黄芪对大鼠冠状动脉结扎后再灌注心肌损伤具有明显的保护作用,其机制可能与改善心肌缺血再灌注冠状微循环与抗氧自由基生成、减轻钙超载等多种机制有关.     

Effects of systemic domestic recombinant human erythropoietin on HIF-1α expression in the retina in a rabbit model of acute high intraocular pressure

Objective To observe the expression of hypoxia inducible faetor-1α (HIF-1α) in the retina of rabbits with acute high intraocular pressure and to investigate the mechanism of systemic domestic recombinant human erythropoietin (rhEPO) protecting the retina from ischemia-reperfusion injury. Methods First, control group and model group were established in rabbit eyes. The acute high intraocular pressure model was established by saline perfusion into anterior chamber, and then hypodermic injection of domestic rhEPO was made. HIF-1α protein in the retina was observed by immunohistochemical staining method on days 1, 3, 7 and 14 after retinal ischemla-reperfusion, respectively. Results No cells with HIF-la positive expression were observed in the retina of the control group. Ceils with HIF-1α positive expression in the model group outnumbered those in the control group (P < 0. 01). The resemblance pattern occurred in EPO group but its degree was slightly greater than that in the model group from day 3 after ischemia-reperfusion (P<0.05). Conclusion Domestic rhEPO can down-regulate the expression of HIF-1α in the retina with acute high intraocular pressure, which may be one of the mechanisms that rhEPO protects the retina from ischemia-reperfusion injury.     

大黄素对模拟冷缺血再灌注后肝细胞内钙离子浓度及细胞凋亡的影响

目的 研究中药大黄素对模拟冷缺血再灌注后肝细胞内钙离子浓度及细胞凋亡的影响.方法 体外培养肝细胞株HL-7702,随机分为对照组和大黄素处理组.对照组未予大黄素处理,大黄素处理组按100、10、1 μmol/L分为高、中、低3个浓度组,建立模拟冷缺血再灌注模型,流式细胞技术检测各组细胞内钙离子浓度及细胞凋亡水平,分别检测各组细胞培养上清液乳酸脱氢酶水平.结果 冷缺血8 h再灌注6 h后,高、中、低浓度大黄素处理组钙离子荧光强度分别为(24.12±0.51)、(26.35±1.34)、(39.12±1.94),均显著低于对照组的105.29±1.01(P<0.01).高、中、低浓度大黄素处理组细胞凋亡率分别为(5.46±0.41)%、(10.64±0.64)%、(11.90±0.50)%,均显著低于对照组的(25.40±1.41)%(P<0.01).高、中浓度大黄素处理组上清液LDH含量分别为(179.67±18.57)u/L、(198.83±14.22)u/L,显著低于对照组的(351.33±34.16)u/L(P<0.01).结论 大黄素可降低模拟冷缺血再灌注后的肝细胞内钙离子浓度,抑制细胞凋亡,减轻肝细胞损伤.     

防挥鞭伤安全座椅的初步研究

以Euro NCAP挥鞭伤动态评估为基础,采用DOE分析手段,得到座椅部分设计参数对挥鞭伤的影响规律.结果表明,随着座椅设计参数的变化,几个损伤评价指标呈非线性变化,而且是互相影响此消彼长.因此,防挥鞭伤安全座椅设计应是一种多目标综合优化设计.