ABSTRACT
Objective To discuss the application value of vehicle-pedestrian collision road traffic accidents reconstruction based on PC-Crash software in forensic identification. Methods A case of vehicle-pedestrian collision was chosen based on a tachograph, then PC-Crash software was applied to construct a vehicle-pedestrian collision model, and reconstruct the vehicle-pedestrian collision road traffic accident. Finally, the process of vehicle-pedestrian collision was reproduced. Results In accident reconstruction, when the car speed was lower than 50km/h, the landing point of the pedestrian after collision was in the front of the car. When the car speed was higher than 50 km/h, after collision, the pedestrian flipped towards the car roof and landed behind the car. With the increase of vehicle speed, throwing distance of the pedestrian increased continuously. When the vehicle collision speed reached 60 km/h, the experimental results in this case were basically consistent with the actual situation of the case. Head acceleration of the pedestrian was at the maximum （1 655.70 m/s2） at 0.080 s. Chest acceleration of the pedestrian increased from 597.63 m/s2 to the peak 675.52 m/s2 at 0.055-0.060 s. Tibia acceleration of the pedestrian increased from 759.26 m/s2 to the first peak 1 367.06 m/s2, then reached the maximum speed （1 718.19 m/s2） at 1.225 s. Conclusion The process of vehicle-pedestrian collision road traffic accidents can be reconstructed based on PC-Crash software under a situation of limited conditions, and can further clarify the speed of the vehicle, the location and degree of human body injury as well as the mechanism of damage of the pedestrian in the accident. Therefore, PC-Crash software has a certain practical value in forensic identification of road traffic accidents.
Subject(s)
Humans , Acceleration , Accidents, Traffic , Forensic Sciences , Head , Pedestrians , SoftwareABSTRACT
Aim To investigate the effects of gastrodin on SH-SY5Y cell autophagy induced by methamphet-amine (METH) and the underlying mechanisms. Methods SY5Y cells were treated by METH with the concentration of 0.5,1.0,1.5,2.0,2.5,3.0 mmol·L-1for 24 h. The morphological changes were ob-served by microscopy,the expression of LC3-Ⅱ,Bec-lin-1,Akt,p-Akt,mTOR and p-mTOR were detected by Western blot. Gastrodin was added to the medium 1 h before METH treatment. Results The SY 5 Y cells were morphologically featured by shrinkage and den-drite disruption after exposed to METH(0~3 mmol· L-1),and autophagic vacuoles occurred in cytoplasm. The expression of LC3-Ⅱ increased over METH dose. Confocal results showed that LC3-Ⅱsignificantly in-creased in METH group as compared with control, while decreased in METH+ Gastrodin group. The ex-pression levels of LC3-Ⅱand Beclin-1 significantly in-creased (P<0.01) in METH group, p-mTOR and p-Akt decreased, and mTOR and Akt showed no signifi-cant difference as compared with control. However, the gastrodin could decrease the expression of LC3-Ⅱand Beclin-1 and increase the expression of mTOR,p-mTOR,Akt and p-Akt as compared with METH-trea-ted groups. Conclusions METH can induce SY5Y cells autophagy. The protective effect of gastrodin a-gainst METH-induced autophag may be related to gast-rodin regulation mTOR and Akt signaling pathway.
ABSTRACT
With the development of the computer simulation technology and the digital simulation technology, the traditional calculation method has been gradually replaced by the digital method to deal the road traffic accident scene and analyse the process. The PC-Crash software simulation system can reconstruct the traffic accidents within 32 vehicles, and the accuracy of reconstruction has been fully verified, which is widely used by the transport police department and the accreditation agency. In this paper, the research of road traffic accident reconstruction using PC-Crash software is reviewed, and the application of road traffic accident reconstruction technology based on PC-Crash software and some existing problems in forensic practice are discussed, which provides reference for the research and identification of road traffic accident simulation and reconstruction and theoretical basis for accident treatment.