To explore the response law of non-lethal large-size kinetic energy projectiles to blunt attack on skin tissue,and to evaluate the skin injury characteristics of the attacked personnel and the use safety of kinetic en...To explore the response law of non-lethal large-size kinetic energy projectiles to blunt attack on skin tissue,and to evaluate the skin injury characteristics of the attacked personnel and the use safety of kinetic energy projectiles.Based on the LS-DYNA simulation software,a three-layer skin simulation model and a Flash-Ball rubber bullet model are established,and the force-time and deformation-time biomechanical corridors of the Flash-Ball rubber bullet impacting human skin tissue are obtained.The corridor curve and the energy transfer and diffusion are analyzed and compared.The safety evaluation of the damage caused by the rubber bullet shooting a human body at different distances is carried out using the empirical formula of the penetration limit.Finally,the safe shooting distance is obtained.The results show that the model used in the simulation has a good correlation with the experimental data,its biomechanical corridor characteristics are different from those of conventional vehicle impact and smallsize projectile response characteristics.The energy transfer and action time of medium and low-speed impact may cause greater damage.The fat layer is the largest energy absorption unit.The minimum safe shooting distance to ensure skin tissue from penetrating damage is 15.8 m,and the limit specific kinetic energy of skin damage is 7.88 J/cm^(2).This study can be extended to the study of biomechanical response law and safety evaluation under the impact of the same type of large kinetic energy projectile,which provides an important theoretical reference for the police to use large kinetic energy projectiles to conduct safe shooting in peacekeeping operations.展开更多
文摘To explore the response law of non-lethal large-size kinetic energy projectiles to blunt attack on skin tissue,and to evaluate the skin injury characteristics of the attacked personnel and the use safety of kinetic energy projectiles.Based on the LS-DYNA simulation software,a three-layer skin simulation model and a Flash-Ball rubber bullet model are established,and the force-time and deformation-time biomechanical corridors of the Flash-Ball rubber bullet impacting human skin tissue are obtained.The corridor curve and the energy transfer and diffusion are analyzed and compared.The safety evaluation of the damage caused by the rubber bullet shooting a human body at different distances is carried out using the empirical formula of the penetration limit.Finally,the safe shooting distance is obtained.The results show that the model used in the simulation has a good correlation with the experimental data,its biomechanical corridor characteristics are different from those of conventional vehicle impact and smallsize projectile response characteristics.The energy transfer and action time of medium and low-speed impact may cause greater damage.The fat layer is the largest energy absorption unit.The minimum safe shooting distance to ensure skin tissue from penetrating damage is 15.8 m,and the limit specific kinetic energy of skin damage is 7.88 J/cm^(2).This study can be extended to the study of biomechanical response law and safety evaluation under the impact of the same type of large kinetic energy projectile,which provides an important theoretical reference for the police to use large kinetic energy projectiles to conduct safe shooting in peacekeeping operations.
文摘目的:探讨SPY1(Speedy A1)和p27^(kip1)(cyclin-dependent kinase inhibitor 1B,p27)在子宫内膜癌中的表达情况及其临床意义。方法:采用生物医学信息数据库分析子宫内膜癌中SPY1、p27^(kip1) mRNA表达水平;采用免疫组织化学染色法及蛋白质印迹法检测子宫内膜癌及正常子宫内膜组织中SPY1、p27^(kip1)蛋白的表达水平,并分析其表达与患者临床病理参数、激素受体、癌症基因组图谱分子分型的关系,以及两者之间的相关性。通过Kaplan-Meier法绘制生存曲线,应用Cox比例风险模型分析影响子宫内膜癌患者的预后因素。结果:SPY1在子宫内膜癌组织中的蛋白质表达水平显著高于不典型增生的子宫内膜及正常子宫内膜组织(P=0.009),p27kip1在子宫内膜癌组织中的蛋白质表达水平显著低于不典型增生的子宫内膜及正常子宫内膜组织(P=0.001);SPY1蛋白表达与肿瘤病理分级(P=0.023)、国际妇产科协会(The International Federation of Gynecology and Obstetrics,FIGO)癌分期(P=0.003),肌层浸润深度(P=0.010)及淋巴结转移(P<0.001)有关,p27kip1蛋白表达与肿瘤病理分级(P=0.001)、FIGO癌分期(P=0.001)及淋巴结转移(P<0.001)有关;SPY1与p27kip1表达呈负相关(r=−0.563,P<0.001);Kaplan-Meier预后分析表明SPY1高表达患者生存率低于低表达患者(P<0.05),p27kip1高表达患者的生存率高于低表达患者(P<0.05)。Cox单因素及多因素分析表明FIGO癌分期(P=0.023)、病理分级(P<0.001)、淋巴结转移(P<0.001)及p27kip1表达(P<0.001)可作为子宫内膜癌患者的独立预后指标。结论:子宫内膜癌组织中SPY1蛋白呈高表达,p27kip1蛋白呈低表达,且两者之间呈负相关,可用于评估子宫内膜癌的发生和发展。
