Objective The simulation of the human mandible injury was carried out by using the finite element simulation technology ,and the biomechanical analysis of simulation results was developed to explore the mechanism of injuries .Methods The Chinese Visible Human digital data were used to establish the three-dimensional element model of mandible injuries ,and the dynam-ic processes of human mandible injuries in different conditions were simulated ,and the biomechanical analysis were carried out by u-sing the Von Mises stress and effective strain .Results The three-dimensional element model of mandible injuries was established , the dynamic damage and fracture of human mandible were simulated successfully ,the mandibular angle and condylar were the predi-lection parts of high-stress ,high-strain and fractures .Conclusion The Von Mises stress and effective strain can be used to predict and judge the bone tissue injuries ,the finite element method can simulate the impact injuries of mandible effectively ,and the simula-ted results can provide guidance and reference for basic research and clinical treatment of oral and maxillofacial injuries .

Objective To apply color Doppler flow imaging (CDFI) and transcranial Doppler (TCD) to the follow-up observation of the changes of cervical vessel,intracranial hemodynamics and cerebrovascular reserve capacity (CVR) of the patients after carotid artery stent implantation.Methods Totally 96 patients with carotid artery stent implantation underwent CDFI and TCD examinations,and the changes of hemodynamics were compared before and 1 month,6 months,1 a and 2 a after implantation.Results The values of peak systolic velocity (PSV) and resistance index (RI) at the areas of carotid stenosis were lower significantly than those before implantation,while the values of PSV,pulsatility index (PI) and CVR of the middle cerebral artery were obviously higher than those before implantation (P＜0.05).There were no significant differences between the cervical and intracranial hemodynamics indexes 1 month,6 months,1 a and 2 a after treatment.Two-year follow-up found 4 cases of restenoses after implantation,and the rate for restenosis was 4.2％.Conclusion Carotid artery stent implantation improves significantly cervical and intracranial blood supply as well as CVR of the carotid stenosis patient,and CDFI combined with TCD can be used for the accurate evaluation of the efficacy and postoperative follow-up of carotid artery stent implantation.

Objective:To analyze the psychological anxiety and social support of HBV-carrying pregnant women and healthy pregnant women, and provide a reference for improving nursing interventions for hepatitis B virus (HBV) -carrying pregnant women.Methods:In this cross-sectional study, totally 314 pregnant women with HBV who attended outpatient services, established health files and had clear test results in a Beijing infectious disease specialist hospital from March to April 2019, and in two other ClassⅢ Grade A hospitals in the same period 420 healthy pregnant women were selected by convenient sampling. The Sociodemographic questionnaire, Self-Anxiety Scale (SAS) and Social Support Rating Scale (SSRS) were used to investigate the pregnant women.Results:There were statistically significant differences between HBV-carrying pregnant women and healthy pregnant women in education level, household registration status, family monthly income per capita, type of medical insurance, duration of pregnancy, status of pregnancy and subjective support scores ( P<0.05) . Multiple linear regression analysis controlling related factors found that whether the pregnant women carried the HBV had no effect on their psychological anxiety ( P>0.05) , and support utilization score, age, pregnancy days and education level affected the psychological anxiety of pregnant women ( P<0.05) .There was no statistically significant difference in SAS scores between the two groups of pregnant women ( t=-0.965, P>0.05) . Conclusions:The status of HBV carrying will not affect pregnant women's psychological anxiety, and factors such as social support utilization, education level, pregnancy days and age will have effect on pregnant women's psychological anxiety. It is recommended to take corresponding intervention measures to improve the utilization of social support, thereby alleviating the psychological anxiety of pregnant women.

China has entered a stage of deep aging. The expanding aging population and subsequently an aging labor force pose significant challenges to China’s social and economic development. European Union (EU) countries have entered the aging phase earlier and to a greater extent. To address the labor shortage and the rising dependency ratio, the EU has implemented a series of policies and measures, including raising retirement age, promoting flexible retirement, enhancing work flexibility, improving welfare for elderly workers, creating age-friendly environments, focusing on occupational health, strengthening knowledge and skills training, and leveraging digital technologies in the workplace. These measures aim to prevent premature exit of elderly workers, better balance their work and life needs, improve occupational health and skills, and enhance overall work efficiency of companies. This review discussed the experience and lessons learned from the EU countries in addressing the aging workforce from the perspectives of occupational health and occupational skills development, aiming to provide rational suggestions to assist China in better adapting the challenges of aging workforce after steadily and orderly advancing the gradual reform of the statutory retirement age, thereby improving the efficiency of the overall workforce and the stability of the labor market, driving the talent dividend of highly educated and skilled middle-aged and elderly employees, and ultimately promoting sustained economic and social development.

Objective To explore the relationship between anxiety sensitivity and psychological stress before parachuting training among parachuting trainees and the mediating role of resilience between them.Methods Anxiety sensitivity index scale(version 3),resilience scale,psychological stress self-evaluation test and self-compiled general information questionnaire were employed for 258 parachuting trainees before training.Pearson correlation analysis was used to analyze the correlations among anxiety sensitivity,resilience and psychological stress.A multiple linear regression analysis was conducted with anxiety sensitivity and resilience as independent variables and psychological stress as dependent variable to explore the relationships among these 3 factors.The mediating effect of resilience on the relationship between anxiety sensitivity and psychological stress was examined using the Hayes Process macro program and bias corrected non-parametric percentile Bootstrap method.Results Before parachuting training,the prevalence of psychological stress among parachuting trainees was 5.0%(13/258).The correlations between anxiety sensitivity,resilience and psychological stress were significant(all P＜0.01).Anxiety sensitivity was positively associated with psychological stress among parachuting trainees(b=0.412,t=7.062,P＜0.01),while resilience was negatively associated with psychological stress(b=-0.187,t=-3.722,P＜0.01).Anxiety sensitivity and resilience were found to explain 31.4%of the total variance.Resilience partially mediated the effect of anxiety sensitivity on psychological stress,accounting for 20.48%of the total effect.Conclusion Parachuting trainees are at a relatively low stress level,with good psychological adaptation.Resilience plays a partial mediating role in the association between anxiety sensitivity and psychological stress.More attention should be paid to parachuting trainees with high anxiety sensitivity,enhancing their resilience,and reducing psychological stress before parachuting training.