Background: China fully implemented the critical illness insurance (CII) program in 2016 to alleviate the economic burden of diseases and reduce catastrophic health expenditure (CHE). With an aging society, it is necessary to analyze the extent of CHE among Chinese households and explore the effect of CII and other associated factors on CHE. Methods: Data were derived from the Sixth National Health Service Survey (NHSS, 2018) in Jiangsu Province. The incidence and intensity of CHE were calculated with a sample of 3660 households in urban and rural areas in Jiangsu Province, China. Logistic regression and multiple linear regression models were used for estimating the effect of CII and related factors on CHE. Results: The proportion of households with no one insured by CII was 50.08% (1833). At each given threshold, from 20% to 60%, the incidence and intensity were higher in rural households than in urban ones. CII implementation reduced the incidence of CHE but increased the intensity of CHE. Meanwhile, the number of household members insured by CII did not affect CHE incidence but significantly decreased CHE intensity. Socioeconomic factors, such as marital status, education, employment, registered type of household head, household income and size, chronic disease status, and health service utilization, significantly affected household CHE. Conclusions: Policy effort should further focus on appropriate adjustments, such as dynamization of CII lists, medical cost control, increasing the CII coverage rate, and improving the reimbursement level to achieve the ultimate aim of using CII to protect Chinese households against financial risk caused by illness.

To predict the propagation of radio waves in the environment of dielectric ground and dielectric obstacles, a new two-way parabolic equation (2W-PE) method based on the domain decomposition principle and surface impedance boundary conditions (SIBC) is proposed. First, we decompose the obstacle area into different subdomains and derive the SIBC in each subdomain in detail; then, the discrete hybrid Fourier transform (DMFT) in the upper subdomain and finite difference (FD) algorithm in the lower subdomain is used to solve 2W-PE combined with SIBC, respectively. After that, we explain the algorithm steps in the process of calculating the total field, compared with the traditional 2W-PE, and then finally introduce the method of moments (MoM) combined with the enhanced discrete complex image (E-DCIM) method for accuracy verification of the new 2W-PE algorithm. The simulation results show that no matter how the obstacle medium parameters change, the results of 2W-PE method proposed in this paper and MoM are always in good agreement, which proves the accuracy of 2W-PE and its superiority in speed. Therefore, this paper provides a reliable and efficient method for solving the problem of radio wave propagation in the presence of obstacles, especially in the case of low-lossy obstacles.

To study the problem of radio wave propagation in an environment of dielectric ground and obstacles, especially in low-lossy obstacles, to consider the propagation inside the obstacle, a new method is proposed to solve the two-way parabolic equation based on the principle of domain decomposition. First, a mathematical model of parabolic equations for reflection and refraction in an environment with obstacles is established. Then, the area of the obstacle is decomposed into two different subdomains; the discrete mixed Fourier transform is used to calculate the field value in the upper subdomain from the top of the obstacle to the absorption boundary, the finite difference method is used to calculate the field value of the lower subdomain inside the obstacle, and the field strengths and phases of the two subdomains coordinate with the boundary conditions. In the process of calculation, we emphatically consider the multiple reflection and transmission paths inside obstacles to make the algorithm results more accurate. In addition, we verified the stability and convergence of the method. Finally, the simulation results show that the proposed method and the method of moments have good consistency, so the algorithm has the characteristics of strong applicability and fast calculation speed, which provide a novel and reliable method to research the wave propagation problem in a modified environment of obstacles.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

ObjectivesBuilding individuals’ positive attitudes during a pandemic is essential for facilitating psychological resilience. However, little is known about how public health measures may improve people’s positive attitudes during a pandemic. We investigated the potential mechanism underlying the association between individuals’ perceived effectiveness of public health measures and positive attitudes towards the success of pandemic control during the COVID-19 pandemic, by examining the parallel mediating effects of three types of threat appraisals: concerns about contracting the virus, perceived impact of the pandemic on life and estimated duration of the pandemic.Design, setting and participantsIn February 2020 when the COVID-19 infection was spreading rapidly in China, a large cross-sectional survey was conducted among 132 054 adults from the 16 districts in Shanghai, China.Outcome measuresPerceived effectiveness of the public health measures, positive attitudes towards the success of pandemic control and threat appraisals.ResultsResults of structural equation modelling supported the hypothesised mediation model: perceived effectiveness of public health measures was associated with lower levels of concerns about contracting the virus (β=−0.20), perceived impact of the pandemic (β=−0.13) and perceived duration of the pandemic (β=−0.20), which were then associated with higher levels of positive attitudes towards the success of pandemic control (βs=−0.12 to −0.25).ConclusionsThe findings suggest that threat appraisals may be important pathways through which individuals’ evaluations of prevention strategies may influence their attitudes towards the success of pandemic control. The health authorities should consider reducing people’s inappropriate threat appraisals when designing public health policies to facilitate people’s positive attitudes during a pandemic.

In the usual process of teaching students about the electromagnetic field, students often have difficulty in understanding the propagation process of invisible electromagnetic waves under different medium environments. To facilitate students understanding and learning of related knowledge, in this article, we first derive the process of solving Maxwell’s equation using finite-difference time-domain (FDTD) under different media environments for the designed experimental models to obtain the spatial distribution of the electromagnetic field. After that, we use the MATLAB language to program the FDTD solution method to verify our theoretical analysis based on the simulation results. Based on this, we develop a convenient and quick interactive mobile software tool, aiming to give students a vivid and intuitive demonstration and explanation for the propagation of electromagnetic waves in different media environments.