Accident causation analysis is of great importance for accident prevention.In order to improve the aviation safety,a new analysis method of aviation accident causation based on complex network theory is proposed in th...Accident causation analysis is of great importance for accident prevention.In order to improve the aviation safety,a new analysis method of aviation accident causation based on complex network theory is proposed in this paper.Through selecting 257 accident investigation reports,45 causative factors and nine accident types are obtained by the three-level coding process of the grounded theory,and the interaction of these factors is analyzed based on the“2-4”model.Accordingly,the aviation accident causation network is constructed based on complex network theory which has scale-free characteristics and small-world properties,the characteristics of causative factors are analyzed by the topology of the network,and the key causative factors of the accidents are identified by the technique for order of preference by similarity to ideal solution(TOPSIS)method.The comparison results show that the method proposed in this paper has the advantages of independent of expert experience,quantitative analysis of accident causative factors and statistical analysis of a lot of accident data,and it has better applicability and advancement.展开更多
Objective: To examine the changes in the express ion of mGluR4 after diffuse brain injury (DBI) and to determine the role of its specific agonist L-2-amino-4-phosphonobutyrate (L-AP4) in vivo. Methods: A total of 161 ...Objective: To examine the changes in the express ion of mGluR4 after diffuse brain injury (DBI) and to determine the role of its specific agonist L-2-amino-4-phosphonobutyrate (L-AP4) in vivo. Methods: A total of 161 male SD rats were randomized into the f ollowing groups. Group A included normal control,sham-operated control and DBI group. DBI was produced according to Marmarous diffuse head injury model. mRN A expression of mGluR4 was detected by hybridization in situ. Group B included D BI alone,DBI treated with normal saline and DBI treated with L-AP4. All DBI ra ts were trained in a series of performance tests,following which they were subj ected to DBI. At 1 and 12 hours,animals were injected intraventricularly with L -AP4 ( 100 mmol/L ,10 μl) or normal saline. Motor and cognitive performance s were tested at 1,3,7,14 days after injury and the damaged neurons were also detected. Results: There was no significant difference between normal con trol group and sham-operated group in the expression of mGluR4 ( P > 0.05 ) . The animals exposed to DBI showed significantly increased expression of mRNA o f mGluR4 compared with the sham-operated animals 1 h after injury ( P < 0.05 ). At 6 hours,the evolution of neuronal expression of mGluR4 in the trauma al one group was relatively static. Compared with saline-treated control animals,rats treated with L-AP4 showed an effective result of decreased number of damag ed neurons and better motor and cognitive performances.Conclusions: Increased expression of mGluR4 is important in the pathophysiological process of DBI and its specific agonist L-AP4 can provide r emarkable neuroprotection against DBI not only at the histopathological level bu t also in the motor and cognitive performance.展开更多
基金supported by the Civil Aviation Joint Fund of National Natural Science Foundation of China(No.U1533112)。
文摘Accident causation analysis is of great importance for accident prevention.In order to improve the aviation safety,a new analysis method of aviation accident causation based on complex network theory is proposed in this paper.Through selecting 257 accident investigation reports,45 causative factors and nine accident types are obtained by the three-level coding process of the grounded theory,and the interaction of these factors is analyzed based on the“2-4”model.Accordingly,the aviation accident causation network is constructed based on complex network theory which has scale-free characteristics and small-world properties,the characteristics of causative factors are analyzed by the topology of the network,and the key causative factors of the accidents are identified by the technique for order of preference by similarity to ideal solution(TOPSIS)method.The comparison results show that the method proposed in this paper has the advantages of independent of expert experience,quantitative analysis of accident causative factors and statistical analysis of a lot of accident data,and it has better applicability and advancement.
文摘Objective: To examine the changes in the express ion of mGluR4 after diffuse brain injury (DBI) and to determine the role of its specific agonist L-2-amino-4-phosphonobutyrate (L-AP4) in vivo. Methods: A total of 161 male SD rats were randomized into the f ollowing groups. Group A included normal control,sham-operated control and DBI group. DBI was produced according to Marmarous diffuse head injury model. mRN A expression of mGluR4 was detected by hybridization in situ. Group B included D BI alone,DBI treated with normal saline and DBI treated with L-AP4. All DBI ra ts were trained in a series of performance tests,following which they were subj ected to DBI. At 1 and 12 hours,animals were injected intraventricularly with L -AP4 ( 100 mmol/L ,10 μl) or normal saline. Motor and cognitive performance s were tested at 1,3,7,14 days after injury and the damaged neurons were also detected. Results: There was no significant difference between normal con trol group and sham-operated group in the expression of mGluR4 ( P > 0.05 ) . The animals exposed to DBI showed significantly increased expression of mRNA o f mGluR4 compared with the sham-operated animals 1 h after injury ( P < 0.05 ). At 6 hours,the evolution of neuronal expression of mGluR4 in the trauma al one group was relatively static. Compared with saline-treated control animals,rats treated with L-AP4 showed an effective result of decreased number of damag ed neurons and better motor and cognitive performances.Conclusions: Increased expression of mGluR4 is important in the pathophysiological process of DBI and its specific agonist L-AP4 can provide r emarkable neuroprotection against DBI not only at the histopathological level bu t also in the motor and cognitive performance.
