The novel coronavirus disease 2019 , characterized by symptoms of fever and pneumonia, was reported in Wuhan, China, at the end of 2019 (Phelan, Katz, & Gostin, 2020). Given the likely transmission of COVID-19 via droplets and aerosols during dental clinical procedures, dental practitioners are at a high risk of COVID-19 infections (Ather, Patel, Ruparel, Diogenes, & Hargreaves, 2020). According to the guidelines of the Chinese Stomatological Association (CSA), dental clinics in China suspended the routine dental services and only provided emergency dental care between January and April 2020 (CSA, 2020). The objective of the study was to investigate the influence of COVID-19 on patients' utilization of dental services during the COVID-19 pandemic.This study was carried out from April 20 to April 27 after the hospital reopening to the public and was approved by the Ethics Committee of Nanjing Stomatological Hospital. A total of 1,032 patients with a dental appointment record in the Nanjing Stomatological Hospital were recruited in the study. A 24-item questionnaire was used to survey patients' demographics, psychological state, behaviour and awareness of COVID-19, and their evaluations on the current dental services (Appendix S1). Sample size was calculated based on the data obtained from the hospital registration system, using a power of 95% and a 3.07% margin of error. Statistical analysis was performed using SPSS 16 (IBM, USA). Kruskal-Wallis H tests were performed to explore the associated factors of different degrees of stress during dental health care visit. p-Value <.05 was considered significant.A total of 956 valid questionnaires were collected, yielding a response rate of 92.6%. Most respondents were females (65.1%), adults < 40 years old (72.3%), living in this city (82.9%) and revisit patients (75.5%) (Table 1). The main reason for patients' visit

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In this study, hydroxyl-terminated polybutadiene–poly(epoxide ionic liquid)–poly(urethane urea) (HTPB-PEIL-PU) membranes, HTPB-PEIL1-PU and HTPB-PEIL2-PU, were prepared by the reaction of functionalized PEIL, poly(1-methylimidazole-3-methyl-ethyloxy)hexafluorophosphate or poly(1-methylimidazole-3-methyl-ethyloxy)bistrifluoromethanesulfonimidate, respectively, with HTPB using 4,4′-diphenylmethane diisocyanate (MDI) as the chain extender. The HTPB-PEIL-PU and HTPB membranes were investigated for the selective recovery of n -butanol from aqueous solutions by pervaporation. PEIL was confirmed to be successfully embedded in the PU membranes by 1 H NMR, Fourier transform infrared, and differential scanning calorimetry measurements. According to our mechanical measurements, the HTPB-PEIL-PU membranes retain the mechanical properties of the original PU membrane. PEIL was shown to enhance the diffusion rate of n -butanol significantly based on swelling behavior tests. The pervaporation flux through the HTPB-PEIL1-PU membrane increased with increasing feed temperature and feed concentration. In contrast, the separation factor of the HTPB-PEIL1-PU membrane increased with increasing feed temperature but decreased with increasing feed concentration. In addition, the HTPB-PEIL2-PU membrane exhibited an optimal separation factor of up to 29.2 at a feed concentration of 3% and a feed temperature of 70 °C, which is superior to that (22.7) through pure HTPB membranes. Furthermore, the HTPB-PEIL1-PU and HTPB-PEIL2-PU membranes show better long-term stability than other supported ionic liquid membranes.