Prevalence and Associated Factors of Depression and Anxiety Among Healthcare Workers During the Coronavirus Disease 2019 Pandemic: A Nationwide Study in Korea.

BACKGROUND: A healthcare system's collapse due to a pandemic, such as the coronavirus disease 2019 (COVID-19), can expose healthcare workers (HCWs) to various mental health problems. This study aimed to investigate the impact of the COVID-19 pandemic on the depression and anxiety of HCWs. METHODS: A nationwide questionnaire-based survey was conducted on HCWs who worked in healthcare facilities and public health centers in Korea in December 2020. Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were used to measure depression and anxiety. To investigate factors associated with depression and anxiety, stepwise multiple logistic regression analysis was performed. RESULTS: A total of 1,425 participating HCWs were included. The mean depression score (PHQ-9) of HCWs before and after COVID-19 increased from 2.37 to 5.39, and the mean anxiety score (GAD-7) increased from 1.41 to 3.41. The proportion of HCWs with moderate to severe depression (PHQ-9 ≥ 10) increased from 3.8% before COVID-19 to 19.5% after COVID-19, whereas that of HCWs with moderate to severe anxiety (GAD-7 ≥ 10) increased from 2.0% to 10.1%. In our study, insomnia, chronic fatigue symptoms and physical symptoms after COVID-19, anxiety score (GAD-7) after COVID-19, living alone, and exhaustion were positively correlated with depression. Furthermore, post-traumatic stress symptoms, stress score (Global Assessment of Recent Stress), depression score (PHQ-9) after COVID-19, and exhaustion were positively correlated with anxiety. CONCLUSION: In Korea, during the COVID-19 pandemic, HCWs commonly suffered from mental health problems, including depression and anxiety. Regularly checking the physical and mental health problems of HCWs during the COVID-19 pandemic is crucial, and social support and strategy are needed to reduce the heavy workload and psychological distress of HCWs.

High energy density in artificial heterostructures through relaxation time modulation.

Electrostatic capacitors are foundational components of advanced electronics and high-power electrical systems owing to their ultrafast charging-discharging capability. Ferroelectric materials offer high maximum polarization, but high remnant polarization has hindered their effective deployment in energy storage applications. Previous methodologies have encountered problems because of the deteriorated crystallinity of the ferroelectric materials. We introduce an approach to control the relaxation time using two-dimensional (2D) materials while minimizing energy loss by using 2D/3D/2D heterostructures and preserving the crystallinity of ferroelectric 3D materials. Using this approach, we were able to achieve an energy density of 191.7 joules per cubic centimeter with an efficiency greater than 90%. This precise control over relaxation time holds promise for a wide array of applications and has the potential to accelerate the development of highly efficient energy storage systems.

Healing Donor Defect States in CVD-Grown MoS2 Field-Effect Transistors Using Oxygen Plasma with a Channel-Protecting Barrier.

Molybdenum disulfide (MoS2 ), a metal dichalcogenide, is a promising channel material for highly integrated scalable transistors. However, intrinsic donor defect states, such as sulfur vacancies (Vs ), can degrade the channel properties and lead to undesired n-doping. A method for healing the donor defect states in monolayer MoS2 is proposed using oxygen plasma, with an aluminum oxide (Al2 O3 ) barrier layer that protects the MoS2 channel from damage by plasma treatment. Successful healing of donor defect states in MoS2 by oxygen atoms, even in the presence of an Al2 O3 barrier layer, is confirmed by X-ray photoelectron spectroscopy, photoluminescence, and Raman spectroscopy. Despite the decrease in 2D sheet carrier concentration (Δn2D = -3.82×1012 cm-2 ), the proposed approach increases the on-current and mobility by 18% and 44% under optimal conditions, respectively. Metal-insulator transition occurs at electron concentrations of 5.7×1012 cm-2 and reflects improved channel quality. Finally, the activation energy (Ea ) reduces at all the gate voltages (VG ) owing to a decrease in Vs , which act as a localized state after the oxygen plasma treatment. This study demonstrates the feasibility of plasma-assisted healing of defects in 2D materials and electrical property enhancement and paves the way for the development of next-generation electronic devices.

Correlates of burnout among healthcare workers during the COVID-19 pandemic in South Korea.

Burnout is a form of negative emotional and physical response to job stress. This study aimed to investigate the prevalence of burnout among healthcare workers responding to the coronavirus disease 2019 (COVID-19) outbreak in Korea and to explore correlates of burnout among healthcare workers. A nationwide questionnaire-based survey was conducted from December 1, 2020, to January 29, 2021 on 1425 healthcare workers who worked in one of the 16 healthcare facilities designated for COVID-19 care, in public health centers, or as paramedics in Korea. Burnout was assessed using 16 Korean-adapted items based on the Oldenburg Burnout Inventory (OLBI). Data were collected using a structured questionnaire and analyzed using the R version 4.1.1 software program. OLBI results indicate clinically exhaustion in 84.5% (1204/1425) and clinically disengagement in 91.1% (1298/1425), and 77.3% (1102/1425) met the score criteria for both the exhaustion and disengagement subscales for burnout. Burnout rate was significantly increased in the group with chronic fatigue symptoms (Fatigue Severity Scale ≥ 3.22) after the outbreak of COVID-19 (OR, 3.94; 95% CI 2.80-5.56), in the female group (OR, 2.05; 95% CI 1.46-2.86), in the group with physical symptoms (Patient Health Questionnaire-15 ≥ 10) after the outbreak of COVID-19 (OR, 2.03; 95% CI 1.14-3.60), in the group with a higher Global Assessment of Recent Stress scale (OR, 1.71; 95% CI 1.46-2.01), in the group with post-traumatic stress symptoms (Primary Care Post-Traumatic Stress Disorder-5 ≥ 2) (OR, 1.47; 95% CI 1.08-2.01), and in the younger age group(OR, 1.45; 95% CI 1.22-1.72). The chronic fatigue symptoms were correlated with cumulative days of care (OR, 1.18; 95% CI 1.02-1.37). The physical symptoms were correlated with average contact hours with COVID-19 patients per day (OR, 1.34; 95% CI 1.17-1.54), and cumulative days of care (OR, 1.21; 95% CI 1.06-1.38). Most Korean healthcare workers suffered from burnout related to excessive workload during the COVID-19 pandemic. During a widespread health crisis like COVID-19, it is necessary to regularly check the burnout status in healthcare workers and reduce their excessive workload by supplementing the workforce and providing appropriate working hours sufficient rest hours.

Psychological Effects of COVID-19 Patient Management Experience among Paramedics and Emergency Medical Technicians: A Nationwide Survey in Korea.

BACKGROUND: Throughout the coronavirus disease 2019 (COVID-19) pandemic, not only medical personnel but also paramedics or emergency medical technicians (EMT) have faced multiple physical and psychological challenges while performing their duties. The current study aimed to evaluate the psychological effects of managing patients with COVID-19 on the paramedics and EMT. MATERIALS AND METHODS: A survey targeting paramedics and EMT in Korea was conducted in December 2020. An official letter requesting participation and with the link to an online-based survey was sent to the Public Emergency Medical Services. Only one response was accepted from each participant. RESULTS: A total of 326 paramedics and EMT responded to the survey. Among them, 66.3% (216/326) had experience in managing patients with COVID-19. No differences in the distribution of sex, age, working area, duration of working experience, and underlying comorbidities were observed between those who did (COVID-19 group) and did not (non-COVID-19 group) experience managing patients with COVID-19. The percentage of participants who showed severe posttraumatic stress disorder (PTSD) symptoms was significantly higher in the COVID group than in the non-COVID group (11.1% vs. 3.6%, P = 0.029). The participants in the COVID group had a significantly higher mean Global Assessment of Recent Stress Scale score than those in the non-COVID group (18.7 ± 11.1 vs. 16.1 ± 9.9, P = 0.042). The proportion of paramedics and EMT willing to leave their job if given a chance was higher in the COVID group than the non-COVID group (24.1% vs. 9.1%, P = 0.001). Additionally, paramedics and EMT in the COVID group tended to show concern regarding exposure to COVID-19 infection. CONCLUSION: The experience of managing patients with COVID-19 resulted in psychological distress among paramedics and EMT in Korea.

Persistent organic pollutants and hyperuricemia in the U.S. general population.

BACKGROUND: Background exposure to persistent organic pollutants (POPs) has emerged as a new risk factor for metabolic syndrome (MetS), while hyperuricemia is associated with MetS through unclear mechanisms. OBJECTIVE: We examined cross-sectional data for consistency with the hypothesis that POPs are a common underlying risk factor of both MetS and hyperuricemia. METHODS: We evaluated associations of POPs with hyperuricemia in subjects aged ≥20 years in the population-based National Health and Nutrition Examination Survey (NHANES) 2003-2004. Sample size was n = 1331 for organochlorine (OC) pesticides and n = 1299 for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). RESULTS: Among all subjects, the risk of hyperuricemia was higher for higher serum concentrations of OC pesticides, PCDDs, and dioxin-like PCBs. PCDFs and nondioxin-like PCBs did not show any clear trend. Adjusted odds ratios (ORs) for OC pesticides, PCDDs, and dioxin-like PCBs were 1.0, 2.4, 2.3, 3.0, and 2.5 (P trend = 0.05), 1.0, 1.6, 1.4, 2.1, and 2.5 (P trend = 0.01), and 1.0, 1.3, 1.4, 1.3, and 2.4 (P trend = 0.04). When we restricted the analyses to subjects without MetS, all these associations appeared to strengthen. CONCLUSION: This study is consistent with our hypothesis that the risk of hyperuricemia relates to background exposure to a mixture of POPs even among persons without MetS. There should be further research about whether avoiding exposure to POPs and otherwise decreasing body burden of POPs would be helpful to prevent or manage hyperuricemia or gout.

Associations between cigarette smoking and total mortality differ depending on serum concentrations of persistent organic pollutants among the elderly.

There are substantial variations of relative risks (RR) in smoking-related mortality by country and time. We hypothesized the RRs in smoking-related mortality might differ depending on serum concentrations of persistent organic pollutants (POPs). We evaluated the associations of cigarette smoking with total mortality in 610 elderly (aged ≥ 70 yr) (702 elderly for organochlorine pesticides [OCPs]) after stratification by serum concentration of POPs, in the National Health and Nutrition Examination Survey (NHANES) 1999-2004 followed through 2006. Summary measures of POPs subclasses showed significant or marginally significant interaction with cigarette smoking on the risk of total mortality. P values for interaction were 0.069 for polychlorinated dibenzo-p-dioxins (PCDDs), 0.008 for polychlorinated biphenyls (PCBs), and 0.024 for OCPs. The effect of smoking on total mortality showed different patterns according to the serum concentration of some POPs. Former or current smokers had 1.4 to 2.9 times higher mortality rates compared with never smokers among participants with higher serum concentrations of POPs (2nd or 3rd tertiles). However, when the level of PCBs or OCPs were low (1st tertile), there were little positive associations between smoking and mortality. Our study suggests that the background exposure to several POPs may be related to variability in smoking-related total mortality.

Association of homocysteine levels with blood lead levels and micronutrients in the US general population.

OBJECTIVES: Even though several epidemiological studies have observed positive associations between blood lead levels and homocysteine, no study has examined whether this association differs by the levels of micronutrients, such as folate, vitamin B6, and vitamin B12, which are involved in the metabolism of homocysteine. In this study, we examined the interactions between micronutrients and blood lead on homocysteine levels. METHODS: This study was performed with 4089 adults aged ≥20 years old in the US general population using the National Health and Nutrition Examination Survey 2003-2004. RESULTS: There were significant or marginally significant interactions between micronutrients and blood lead levels on mean homocysteine levels. Positive associations between blood lead and homocysteine were clearly observed among subjects with low levels of folate or low vitamin B6 (p-trend <0.01, respectively). However, in the case of vitamin B12, there was a stronger positive association between blood lead and homocysteine among subjects with high levels of vitamin B12, compared to those with low levels of vitamin B12. In fact, the levels of homocysteine were already high among subjects low in vitamin B12, irrespective of blood lead levels. When we used hyperhomocysteinemia (homocysteine>15 µmol/L) as the outcome, there were similar patterns of interaction, though p-values for each interaction failed to reach statistical significance. CONCLUSIONS: In the current study, the association between blood lead and homocysteine differed based on the levels of folate, vitamin B6, or vitamin B12 present in the blood. It may be important to keep sufficient levels of these micronutrients to prevent the possible harmful effects of lead exposure on homocysteine levels.

Associations between organochlorine pesticides and vitamin D deficiency in the U.S. population.

BACKGROUND: Recently low dose organochlorine (OC) pesticides have been strongly linked to various chronic diseases including diabetes and cardiovascular diseases. Both field and animal studies have suggested a possibility that persistent lipophilic chemicals like OC pesticides can cause vitamin D deficiency, but there have been no human studies of exposure to any chemical as a possible cause of vitamin D deficiency. This study was performed to examine if serum concentrations of OC pesticides were associated with serum concentrations of 25-hydroxyvitamin D (25(OH)D) in the U.S. general population. METHODOLOGY/PRINCIPAL FINDINGS: Cross-sectional associations of serum OC pesticides with serum 25(OH)D were investigated in 1,275 subjects aged ≥20 in the National Health and Nutrition Examination Survey (NHANES), 2003-2004. We selected 7 OC pesticides detectable in ≥80% of participants. Among the 7 OC pesticides, p,p'-DDT (ß = -0.022, P<0.01), p,p'-DDE (ß = -0.018, P = 0.04), and ß-hexachlorocyclohexane (ß = -0.022, P = 0.02) showed significant inverse associations with serum 25(OH)D levels. When study subjects were stratified by age, race, and the presence of various chronic diseases, p,p'-DDT showed consistent inverse associations in all subgroups, although stronger associations tended to be observed among subjects with old age, white race, or chronic diseases. CONCLUSION/SIGNIFICANCE: The current study suggests that the background exposure to some OC pesticides leads to vitamin D deficiency in human. Considering the importance of vitamin D deficiency in the development of chronic diseases, chemical exposure as a possible cause of vitamin D deficiency should be evaluated in prospective and experimental studies.