Terahertz spectral investigation of temperature induced polymorphic transformation of 2,2dinitroethylene-1,1-diamine.

The dynamic process of polymorphic transformations provides deep insights into the understanding of both the performance of explosives and its packing sensitivity. While terahertz spectroscopy is a sensitive tool that can be used to characterize its intermolecular forces. In this paper, terahertz time-domain spectroscopy (THz-TDS) is employed to investigate the polymorphic transformations of the explosive 2,2dinitroethylene-1,1-diamine (FOX-7) under a heating process. Solid-state density functional theory (DFT) uncovers the physical mechanisms that contribute to the polymorphic transformation. This is achieved by assessing the calculated spectra relative to the actual spectra from experiment. The results suggest that the THz spectral features that arise represent a redistribution of the intermolecular forces during the polymorphic transformations. This research will assist the understanding of the evolving properties of FOX-7, under external stimuli, which is vital knowledge for an explosive substance that can combust or detonate.

The willingness for dietary and behavioral changes in frontline epidemic prevention workers after experiencing the outbreak of COVID-19 in China: a cross-sectional study

BACKGROUND@#The 2019 novel coronavirus disease (COVID-19) has had a massive impact on public health, resulting in sudden dietary and behavioral habit changes. Frontline epidemic prevention workers play a pivotal role against COVID-19. They must face high-risk infection conditions, insufficient anti-epidemic material supplies, mental pressure, and so on. COVID-19 seriously affects their dietary and behavioral habits, and poor habits make them more susceptible to COVID-19. However, their baseline dietary and behavioral habits before COVID-19 and their willingness to change these habits after the outbreak of COVID-19 remain unclear for these workers in China. This study aimed to explore the baseline dietary and behavioral habits of frontline workers and their willingness to change these habits after the outbreak of the epidemic; in addition, susceptible subgroups were identified by stratified analyses as targets of protective measures to keep them from being infected with COVID-19.@*METHODS@#A cross-sectional study was conducted through an online questionnaire using a sample of 22,459 valid individuals living in China, including 9402 frontline epidemic prevention workers.@*RESULTS@#Before COVID-19, 23.9% of the frontline epidemic prevention workers reported a high-salt diet, 46.9% of them reported a high frequency of fried foods intake, and 50.9% of them smoked cigarettes. After the outbreak of COVID-19, 34.6% of them expressed a willingness to reduce salt intake, and 43.7% of them wanted to reduce the frequency of pickled vegetables intake. A total of 37.9% of them expressed a willingness to decrease or quit smoking, and 44.5% of them wanted to increase sleep duration. Significant differences in the baseline dietary and behavioral habits and the willingness to change their habits were observed between frontline epidemic prevention workers and other participants. Among the frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19, frontline epidemic prevention experience was a promoting factor for adopting worse dietary and behavioral habits, including those in the high-salt intake subgroup (OR, 2.824; 95% CI, 2.341-3.405) and the 11-20 cigarettes/day subgroup (OR, 2.067; 95% CI, 1.359-3.143).@*CONCLUSIONS@#The dietary and behavioral habits of frontline epidemic prevention workers were worse than that those of other participants before COVID-19. They had a greater willingness to adopt healthy dietary and behavioral habits after experiencing the outbreak of COVID-19. However, frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19 continued in engage in these poor habits. Dietary and behavioral intervention policies should be drafted to protect their health, especially frontline epidemic prevention workers with poor habits at baseline.

Characteristics and Treatment Comparison of Military Training Injury Caused by Distal Femoral Fractures / 医疗卫生装备

Objective To analyze the characteristics of military training injury caused by distal femoral fractures that used reverse interlocking intramedullary nail(retrograte nails) and condylar plate to fix,and then compare the clinical treatment effects.Methods Retrospective analysis of clinical information of 30 cases,14 cases were treated with reverse interlocking intramedullary nail(reverse nail group) and 16 cases with condyle plate fixation(condyle plate group),all the cases were followed up for 12～20 months to compare the treatment effect and complications.Results According to Merchan criteria with clinical evaluation of knee function,the rate of good and excellent was 85.7% in the reverse interlocking in-tramedullary nail group,68.7%(P