Research on the Prediction Model of Engine Output Torque and Real-Time Estimation of the Road Rolling Resistance Coefficient in Tracked Vehicles.

Road parameter identification is of great significance for the active safety control of tracked vehicles and the improvement of vehicle driving safety. In this study, a method for establishing a prediction model of the engine output torques in tracked vehicles based on vehicle driving data was proposed, and the road rolling resistance coefficient f was further estimated using the model. First, the driving data from the tracked vehicle were collected and then screened by setting the driving conditions of the tracked vehicle. Then, the mapping relationship between the engine torque Te, the engine speed ne, and the accelerator pedal position ß was obtained by a genetic algorithm-backpropagation (GA-BP) neural network algorithm, and an engine output torque prediction model was established. Finally, based on the vehicle longitudinal dynamics model, the recursive least squares (RLS) algorithm was used to estimate the f. The experimental results showed that when the driving state of the tracked vehicle satisfied the set driving conditions, the engine output torque prediction model could predict the engine output torque T^e in real time based on the changes in the ne and ß, and then the RLS algorithm was used to estimate the road rolling resistance coefficient f^. The average coefficient of determination R of the T^e was 0.91, and the estimation accuracy of the f^ was 98.421%. This method could adequately meet the requirements for engine output torque prediction and real-time estimation of the road rolling resistance coefficient during tracked vehicle driving.

MiR-455-5p Attenuates Cerebral Ischemic Reperfusion Injury by Targeting FLT3.

Cerebral ischemia-reperfusion (I/R) injury is a terrible disease which results in the dysfunction and structural damage of brain tissues. Growing evidence implies that miR-455-5p is implicated in the regulation of pathogenesis of several diseases. The aim of this study is to reveal the role of miR-455-5p in cerebral I/R injury and the regulatory mechanism. We established a vitro model by inducing SH-SY5Y and PC-12 cells with oxygen-glucose deprivation and reoxygenation. The experimental cerebral I/R rat model was established by middle cerebral artery occlusion operation. The findings indicated that miR-455-5p expression was downregulated in oxygen-glucose deprivation and reoxygenation induced cells and I/R rat model. In addition, miR-455-5p upregulation inhibited SH-SY5Y cell apoptosis and cerebral damage, whereas miR-455-5p silencing promoted SH-SY5Y cell apoptosis and cerebral damage. Mechanistically, luciferase reporter assay corroborated that miR-455-5p could bind with feline mcDonough sarcoma-like tyrosine kinase 3 (FLT3) mRNA. However, the role of FLT3 in cerebral I/R injury was rarely investigated. Real-time polymerase chain reaction revealed that FTL3 expression was negatively regulated by miR-455-5p. FTL3 upregulation reversed the inhibitory effects of miR-455-5p upregulation on PC-12 and SH-SY5Y cell apoptosis. Therefore, our study verified that miR-455-5p improved cerebral I/R injury by targeting FLT3, which suggests a potential new target for the prevention of cerebral I/R injury.

[Effect of Chit-oligosaccharide/Collagen Composite Gels on Pre-osteoblastic MC3T3-E1s Differentiation].

Chit-oligosaccharide(COS)is a low-molecular,water-soluble mass with higher biological activity,which can be absorbed by human body easily and interact with cells directly.Based on the excellent biological properties of collagen(Col)and COS,a series of Col and COS composite hydrogel(Col/COSn)was constructed in this study.The effect of composite hydrogel on cells proliferation,differentiation and related osteogenic gene expression was evaluated on pre-osteoblast MC3T3-E1 s.The experimental results showed that all the Col/COS composite gels could promote the growth of MC3T3-E1 s,proliferation and bone related gene expression compared to that of pure Col gels.And there was significant difference among the composite hydrogel groups with different degrees of polymerization of COS.The effect of the composite gel which contained chitotetraose(COS4)or chitohexaose(COS6)on the cells proliferation was better than that of other groups,while on cells differentiation and related osteogenic gene expression the composite gel contained chitopentaose(COS5)was the best in all the groups.