Response of PM2.5 chemical composition to the emission reduction and meteorological variation during the COVID-19 lockdown.

PM2.5 is a main atmospheric pollutant with various sources and complex chemical compositions, which are influenced by various factors, such as anthropogenic emissions (AE) and meteorological conditions (MC). MC have a significant impacts on variations in atmospheric pollutant; therefore, emission reduction policies and ambient air quality are non-linearly correlated, which hinders the accurate assessment of the effectiveness of control measures. In this study, we conducted online observations of PM2.5 and its chemical composition in Hohhot, China, from December 1, 2019, to February 29, 2020, to investigate how the chemical compositions of PM2.5 respond to the variations in AE and MC. Moreover, the random forest (RF) model was used to quantify the contributions of AE and MC to PM2.5 and its chemical composition during severe hazes and the COVID-19 pandemic lockdown period. During the clean period, MC reduced PM2.5 concentrations by 124%, while MC incresed PM2.5 concentrations by 49% during severe pollution episode. Inorganic aerosols (SO42-, NO3-, and NH4+) showed the strongest response to MC. MC significantly contributed to PM2.5 (36%), SO42- (32%), NO3- (29%), NH4+ (28%), OC (22%), and SOC (17%) levels during pollution episodes. From the pre-lockdown to lockdown period, AE (MC) contributed 52% (48%), 81% (19%), 48% (52%), 68% (32%), 59% (41%), and 288% (-188%) to the PM2.5, SO42-, NO3-, NH4+, OC, and SOC reductions, respectively. The variations in MC (especially the increase in relative humidity) rapidly generated meteorologically sensitive species (SO42-, NO3-, and NH4+), which led to severe winter pollution. This study provides a reference for assessing the net benefits of emission reduction measures for PM2.5 and its chemical compositions.

Associations of insulin sensitivity and immune inflammatory responses with child blood lead (Pb) and PM2.5 exposure at an e-waste recycling area during the COVID-19 lockdown.

Fine particular matter (PM2.5) and lead (Pb) exposure can induce insulin resistance, elevating the likelihood of diabetes onset. Nonetheless, the underlying mechanism remains ambiguous. Consequently, we assessed the association of PM2.5 and Pb exposure with insulin resistance and inflammation biomarkers in children. A total of 235 children aged 3-7 years in a kindergarten in e-waste recycling areas were enrolled before and during the Corona Virus Disease 2019 (COVID-19) lockdown. Daily PM2.5 data was collected and used to calculate the individual PM2.5 daily exposure dose (DED-PM2.5). Concentrations of whole blood Pb, fasting blood glucose, serum insulin, and high mobility group box 1 (HMGB1) in serum were measured. Compared with that before COVID-19, the COVID-19 lockdown group had lower DED-PM2.5 and blood Pb, higher serum HMGB1, and lower blood glucose and homeostasis model assessment of insulin resistance (HOMA-IR) index. Decreased DED-PM2.5 and blood Pb levels were linked to decreased levels of fasting blood glucose and increased serum HMGB1 in all children. Increased serum HMGB1 levels were linked to reduced levels of blood glucose and HOMA-IR. Due to the implementation of COVID-19 prevention and control measures, e-waste dismantling activities and exposure levels of PM2.5 and Pb declined, which probably reduced the association of PM2.5 and Pb on insulin sensitivity and diabetes risk, but a high level of risk of chronic low-grade inflammation remained. Our findings add new evidence for the associations among PM2.5 and Pb exposure, systemic inflammation and insulin resistance, which could be a possible explanation for diabetes related to environmental exposure.

Prevalence and Predictors of Internet Addiction Among Adolescents Before the First Wave of COVID-19 Lockdown in India.

Background Internet dependency behavior was found to be prevalent among adolescents even before the first wave of COVID-19 lockdowns across the world including India. Adolescent users develop Internet addiction due to various risk factors. Aim The aim is to measure the prevalence and psychosocial predictors of internet addiction among adolescents before the first wave of the COVID-19 lockdown in India. Methods A cross-sectional, descriptive study before the first wave of the COVID-19 lockdown, included 1199 adolescents of both genders, aged 11 to 19 years, at selected educational settings from a city in south India, by using Young's Internet addiction test (IAT)-20 and structured questioner. Results The study found almost all the participants (100%) were using the internet in a day and the highest number of subjects started using the internet during their 6th standard of education (13%). Before the first wave of COVID-19 lockdown, the prevalence of a total of mild, moderate, and severe forms of internet addiction among adolescents was 65%. Individual, family, and community-related risk factors were found significant association with Internet addiction. The age of 14-16 years (OR 2.050, p= 0.000), duration of internet use in a day (OR 0.740, p= 0.064), financial matters (OR 0.981, p=0.016), total internet addiction score (OR 1.03, p=0.035) and timings of internet use (OR 1.161, p=0.004), were significant predictors of Internet addiction. Conclusion Internet addiction was prevalent and a notable behavior addiction among adolescents during the margin time of pre-pandemic and the first wave of the COVID-19 lockdown in India. The study highlighted many significant psychosocial risk factors and predictors of Internet Addiction in adolescents, thus the need for a panoramic approach to identify internet addiction in adolescents, to bring the modest behavior of healthy use of the internet in adolescents.

Intestinal Parasitic Infection in Children and Adolescents With Ocular Diseases: The Prevalence, Spectrum, and Effect of Lockdown During the COVID-19 Pandemic.

INTRODUCTION: People with visual impairments and blindness face challenges in performing regular tasks such as maintaining proper sanitation, which makes them vulnerable to intestinal parasitic infections. AIMS AND OBJECTIVES: This study aims to examine the prevalence and distribution of intestinal parasitic infections in children and adolescents with ocular diseases and to assess if the lockdown during the COVID-19 pandemic affected these rates. METHODS: This retrospective, hospital record-based study was conducted among children and adolescents attending the Regional Institute of Ophthalmology in Kolkata, India. It involved routine stool examinations as part of their treatment during 2019-2020. Early morning stool specimens were collected and brought to the institute laboratory in containers. Stools were examined under a microscope for cysts, ova, parasites, and adult worms. Findings were recorded in the laboratory record book. These data were then extracted into a spreadsheet and analyzed using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York). RESULTS: The prevalence of intestinal parasitic infections was 8.59% (59 out of 687 patients). Among those 59 positive cases, Ascaris lumbricoides, Giardia lamblia, Entamoeba histolytica, Trichuris trichiura, Taenia spp., Enterobius vermicularis, and Isospora belli were detected in 27 (45.8%), 15 (25.4%), 8 (13.6%), 6 (10.2%), 3 (5.1%), 2 (3.4%), and 1 (1.7%) patients, respectively. The positivity rate of stool samples was higher from September and thereafter from January to March. The sample positivity rate was higher post-pandemic and lockdown, but not statistically significant (11.5% vs. 5.3%; χ²=4.044, df=1, p=0.44). CONCLUSION: Ascaris lumbricoides was the most commonly observed intestinal parasite in children and adolescents with ocular disease in our setting. Seasonal variation was noted with higher case positivity at the end of the rainy season and thereafter in winter. Therefore, we propose to strengthen the routine deworming program during this period in Eastern India. Higher sample positivity after the pandemic may be attributed to school closures during the lockdown period, which might have caused some children to miss their routine deworming medication.

A longitudinal study of child adjustment during the COVID-19 pandemic: the protective role of the parent-child relationship in middle childhood.

This longitudinal study assessed how parent-child relationship quality during the first COVID-19 lockdown was related to changes in internalizing, externalizing, and sleep problems during the first months of the pandemic: during lockdown, partial deconfinement, and total deconfinement. Participants included 167 children (9-12 year) and their parents recruited in the province of Quebec, Canada. Child behavior problems decreased between lockdown and the two deconfinement assessments, but more sleep and behavior problems were associated with lower levels of relationship quality (more conflict, less closeness, and more insecure attachment). Significant interaction effects showed that changes in externalizing and sleep problems varied as a function of parent-child relationship. Results support the critical importance of the parent-child relationship with regard to child adjustment in middle childhood in times of crisis such as a pandemic. They also highlight resilience in children aged 9 to 12, with a decrease in problems over time.

Changes in Sleep Duration and Sleep Timing in the General Population from before to during the First COVID-19 Lockdown: A Systematic Review and Meta-Analysis.

BACKGROUND: The COVID-19 lockdown had a profound effect on everyday life, including sleep health. This systematic review and meta-analysis evaluated changes in quantitative sleep parameters during the first lockdown compared with pre-lockdown in the general population. METHODS: A search in scientific databases was performed to identify eligible observational studies from inception to 8 February 2023. We performed a random effects meta-analysis of those studies reporting (a) means of sleep duration, time in bed (TIB), and sleep timing (bedtime and wake-up time); (b) the percentages of atypical sleep duration before and during the lockdown; (c) the percentages of change in sleep duration and sleep timing. RESULTS: A total of 154 studies were included. A small increase in sleep duration (0.25 standardized mean difference, 95% CI 0.180-0.315) was found, with 55.0% of the individuals reporting changes, predominantly an increase (35.2%). The pooled relative risk for sleeping more than 8/9 h per night was 3.31 (95% IC 2.60-4.21). There was a moderately significant delay in sleep timing and a surge in napping. CONCLUSION: An increase in sleep duration and napping, and delayed sleep timing were observed. High-quality studies should evaluate whether these parameters have now become chronic or have returned to pre-lockdown values.

Provision of Telepsychological Care Via Email during COVID-19 Confinement: An Exploratory Study.

Within teletherapy, email interventions have been studied scarcely. For this reason, this exploratory study aims to characterize the assistance provided by email in a university telepsychology service and to compare the data with the assistance provided by telephone in the same service and period. For this purpose, the records of 81 users assisted via email during the COVID-19 pandemic lockdown in Spain were analyzed. The data were compared with those of the 338 users assisted by telephone in the same period. Despite its many limitations, results indicate high satisfaction with the email modality. Users express that they prefer a preference for using email when they do not feel safe in other ways. We found a lot of variation between the number of emails exchanged and the days that each case was active. Additionally, differences were found with telephone users in aspects such as age (email users being younger) and in a depression screening (email users scoring more positively). This study concludes on the high potential of this channel for the application of certain techniques (e.g., psychoeducation) or for people with certain characteristics.

Atmospheric Oxidation Capacity Elevated during 2020 Spring Lockdown in Chengdu, China: Lessons for Future Secondary Pollution Control.

This study presents the measurement of photochemical precursors during the lockdown period from January 23, 2020, to March 14, 2020, in Chengdu in response to the coronavirus (COVID-19) pandemic. To derive the lockdown impact on air quality, the observations are compared to the equivalent periods in the last 2 years. An observation-based model is used to investigate the atmospheric oxidation capacity change during lockdown. OH, HO2, and RO2 concentrations are simulated, which are elevated by 42, 220, and 277%, respectively, during the lockdown period, mainly due to the reduction in nitrogen oxides (NOx). However, the radical turnover rates, i.e., OH oxidation rate L(OH) and local ozone production rate P(O3), which determine the secondary intermediates formation and O3 formation, only increase by 24 and 48%, respectively. Therefore, the oxidation capacity increases slightly during lockdown, which is partly attributed to unchanged alkene concentrations. During the lockdown, alkene ozonolysis seems to be a significant radical primary source due to the elevated O3 concentrations. This unique data set during the lockdown period highlights the importance of controlling alkene emission to mitigate secondary pollution formation in Chengdu and may also be applicable in other regions of China given an expected NOx reduction due to the rapid transformation to electrified fleets in the future.

Patterns and outcomes of acute toxicological cases before, during, and after COVID-19 lockdown in Sohag University hospitals, Egypt.

Background: Toxicologists manage poisoning by preventing, detecting, and treating it, which requires continuous data collection and analysis of toxicological hazards. Aim of the work: The study aims to report and compare the pattern and outcome of acute toxicological cases admitted to Sohag University Hospitals during the COVID-19 lockdown (2020-2021) with the year before (2019) and the year after (2022). Methods: This comparative study reviewed the sociodemographic and clinical data in the medical records. The study showed that Sohag University Hospitals received 670 toxicological cases between 2019 and 2022; 105 cases in 2019, 347 cases in 2020-2021, and 218 cases in 2022. Results: Most of patients were below seven years with no sex differences. Accidental poisoning was the most frequent toxicity. The oral route was the most common in the three studied periods. During the lockdown, metal phosphide was the most frequent (19.0%), while therapeutic agents were the most reported after the lockdown (23.9%). The delay time showed a significant difference between the studied periods (p-value < 0.001). In the three studied periods, complete recovery was achieved in more than 70% of cases; however, the mortality rate and the rate of complications during the lockdown period (10.4% and 9.5%, respectively) were almost twice those of the year before and the year after the pandemic with significant odds ratio of mortality during pandemic (OR) 0.07 CI 95% (0.02, 0.11). Conclusion: The pandemic had a bad impact on outcomes as showed the highest percentage of mortality compared to before and after COVID-19 periods.

The Prevalence of Anxiety Among University Students in the United Arab Emirates Following the COVID-19 Lockdown.

INTRODUCTION: The COVID-19 pandemic, with its consequential lifestyle changes, is anticipated to contribute to increased anxiety levels, particularly among university students who already contend with significant academic stress. We aim to assess the prevalence of anxiety among university students in the United Arab Emirates (UAE) following the COVID-19 lockdown period. METHODS: We conducted a descriptive cross-sectional study among students enrolled in UAE universities. A self-administered questionnaire was utilized to gather demographic data, assess anxiety levels using the generalized anxiety disorder-7 scale, explore potential factors associated with heightened anxiety, investigate the impact of increased anxiety on academic performance, and identify coping mechanisms employed post-lockdown. RESULTS: Of the 369 participating students, anxiety levels were minimal in 87 (23.6%), mild in 163 (44.2%), and moderate to severe in 119 (32.2%) subjects. Moreover, increased anxiety levels were significantly correlated with poor/fair sleep quality (p=0.002). Importantly, students with moderate to severe anxiety levels exhibited poorer performance in exams and assignments (p=0.001) and encountered difficulties in maintaining focus on studies (p<0.001). The predominant coping mechanisms employed by students included self-distraction, prayer, and maintaining a positive attitude. CONCLUSION: The majority of students in our study experienced mild to severe levels of anxiety following the COVID-19 lockdown period. We hope that our findings will prompt university and government officials to implement effective screening and preventive strategies to adequately support university students in future public health crises.

Assessment and mapping of noise pollution in recreation spaces using geostatistic method after COVID-19 lockdown in Turkey.

Increased use of recreational areas after the lifting of COVID-19 pandemic restrictions has led to increased noise levels. This study aims to determine the level of noise pollution experienced in recreational areas with the increasing domestic and international tourism activities after the lifting of pandemic lockdowns, to produce spatial distribution maps of noise pollution, and to develop strategic planning suggestions for reducing noise pollution in line with the results obtained. Antalya-Konyaalti Beach Recreation Area, the most important international tourism destination of Turkey, is determined as the study area. To determine the existing noise pollution, 31 measurement points were marked at 100 m intervals within the study area. Noise measurements were taken during the daytime (07:00-19:00), evening (19:00-23:00), and nighttime (23:00-07:00) on weekdays (Monday, Wednesday, Friday) and weekends (Sunday) over 2 months in the summer when the lockdown was lifted. In addition, the sound level at each measurement point was recorded for 15 min, while the number of vehicles passing through the area during the same period was determined. The database created as a result of measurements and observations was analyzed using statistical and geostatistical methods. After the analysis of the data, it was found that the co-kriging-stable model showed superior performance in noise mapping. Additionally, it was revealed that there is a high correlation between traffic density and noise intensity, with the highest equivalent noise level (Leq) on weekdays and weekend evenings due to traffic and user density. In conclusion, regions exposed to intense noise pollution were identified and strategic planning recommendations were developed to prevent/reduce noise sources in these identified regions.

The Day After: The Longitudinal Effect of COVID-19 Lockdown on Quality of Life of University Students and the Moderator Role of Mindfulness.

Background: The COVID-19 lockdown has been a major stressor for the general population, posing a considerable threat to quality of life (QoL), particularly among university students. Existing research highlights the protective role of dispositional mindfulness (DM) in mitigating stressors; however, its influence on moderating the impact of COVID-19 on QoL remains unknown. We used a longitudinal design to assess the QoL of undergraduate students before and after the COVID-19 lockdown, while also examining the potential moderating effect of DM on this impact. Methods: One hundred eleven Spanish undergraduate students were recruited in 2019, and 103 were followed-up in 2020. Instruments comprised a demographic questionnaire, the World Health Organization Quality of Life BREF (WHOQOL-BREF) inventory to assess QoL, and the Five Facets Mindfulness Questionnaire (FFMQ) to assess DM. Results: Analyses revealed statistically significant differences between the two time points in WHOQOL-BREF: Psychological, Social Relationships, and Environmental. Moderation analyses revealed that the impact of COVID-19 on WHOQOL-BREF Psychological scores was moderated by FFMQ-Observe and FFMQ-Non-judging. Conclusions: The COVID-19 lockdown resulted in a reduction of QoL among undergraduate students, yet this impact was moderated by DM. Specifically, present moment attention to experience (observe) and non-judgmental awareness attenuated the impact of COVID-19 on psychological well-being. Future research should focus on evaluating the protective role of preventive interventions designed to increase DM among undergraduate students.

When one door closes: a qualitative exploration of women's experiences of access to sexual and reproductive health services during the COVID-19 lockdown in Nigeria.

BACKGROUND: COVID-19 pandemic widely disrupted health services provision, especially during the lockdown period, with females disproportionately affected. Very little is known about alternative healthcare sources used by women when access to conventional health services became challenging. This study examined the experiences of women and adolescent girls regarding access to sexual and reproductive health (SRH) services during the COVID-19 lockdown in Nigeria and their choices of alternative healthcare sources. METHODS: The study sites were two northern states, two southern states, and the Federal Capital Territory. Qualitative data were obtained through 10 focus group discussion sessions held with married adolescents, unmarried adolescents, and older women of reproductive age. The data were transcribed verbatim and analysed using a thematic approach and with the aid of Atlas ti software. RESULTS: Women reported that access to family planning services was the most affected SRH services during the COVID-19 lockdown. Several barriers to accessing SRH services during COVID-19 lockdown were reported, including restriction of vehicular movement, harassment by law enforcement officers, fear of contracting COVID-19 from health facilities, and fear of undergoing compulsory COVID-19 tests when seeking care in health facilities. In the face of constrained access to SRH services in public sector facilities during the COVID-19 lockdown, women sought care from several alternative sources, mostly locally available and informal services, including medicine vendors, traditional birth attendants, and neighbours with some health experience. Women also widely engaged in self-medication, using both orthodox drugs and non-orthodox preparations like herbs. The lockdown negatively impacted on women's SRH, with increased incidence of sexual- and gender-based violence, unplanned pregnancy resulting from lack of access to contraceptives, and early marriage involving adolescents with unplanned pregnancies. CONCLUSION: COVID-19 negatively impacted access to SRH services and forced women to utilise mostly informal service outlets and home remedies as alternatives to conventional health services. There is a need to ensure the continuity of essential SRH services during future lockdowns occasioned by disease outbreaks. Also, community systems strengthening that ensures effective community-based health services, empowered community resource persons, and health-literate populations are imperative for overcoming barriers to healthcare access during future lockdowns.

The impact of the COVID-19 pandemic on the mood and family relationships of runners.

Introduction: The aim of this study was to analyze the impact of the COVID-19 lockdown on the mood of amateur runners and on their relationships with their partners and families. Methods: Adult runners 18 years or older (N = 260) completed an online survey that included demographic information, standardized psychological assessments of Exercise Dependence (EDS-R) and mood (POMS), and, to measure relationship functioning, either the Dyadic Adjustment Scale (DAS) if they did not have children, or the Basic Family Evaluation Questionnaire (CERFB), measuring conjugal and parental relationships. Participants also answered questions about their exercise habits and the coping strategies they adopted during lockdown. Results: The results suggest that runners who saw the largest reductions in time spent exercising during lockdown tended to feel significantly less energetic (p < 0.05) and friendly (p < 0.01). In addition, they recorded significantly lower scores in marital satisfaction with their peers (p < 0.05). The runners with a higher degree of dependence on physical exercise registered significantly higher levels of depression, tension and anger than non-dependent runners (p < 0.001). Runners whose partners were physically active and did not have children had significantly higher scores marital satisfaction than runners whose partners were not physically active and had children (p < 0.05). Discussion: These findings seem to indicate that the psychological approach to athletes in the context of crises such as the pandemic should consider not only individual aspects, but also include the family perspective.

Quantifying the impact of urban road traffic on air quality: activity pre-pandemic and during partial and full lockdowns.

The impact of partial and full COVID lockdowns in 2020 on vehicle miles traveled (VMT) in Kuwait was estimated using data extracted from the Directions API of Google Maps and a Python script running as a cronjob. This approach was validated by comparing the predictions based on the app to measuring traffic flows for 1 week across four road segments considered in this study. VMT during lockdown periods were compared to VMT for the same calendar weeks before the pandemic. NOx emissions were estimated based on VMT and were used to simulate the spatial patterns of NOx concentrations using an air quality model (AERMOD). Compared to pre-pandemic periods, VMT was reduced by up to 25.5% and 42.6% during the 2-week partial and full lockdown episodes, respectively. The largest reduction in the traffic flow rate occurred during the middle of these 2-week periods, when the traffic flow rate decreased by 35% and 49% during the partial and full lockdown periods, respectively. The AERMOD simulation results predicted a reduction in the average maximum concentration of emissions directly related to VMT across the region by up to 38%, with the maximum concentration shifting to less populous residential areas as a result of the lockdown.

Machine learning insights into PM2.5 changes during COVID-19 lockdown: LSTM and RF analysis in Mashhad.

This study seeks to investigate the impact of COVID-19 lockdown measures on air quality in the city of Mashhad employing two strategies. We initiated our research using basic statistical methods such as paired sample t-tests to compare hourly PM2.5 data in two scenarios: before and during quarantine, and pre- and post-lockdown. This initial analysis provided a broad understanding of potential changes in air quality. Notably, a low reduction of 2.40% in PM2.5 was recorded when compared to air quality prior to the lockdown period. This finding highlights the wide range of factors that impact the levels of particulate matter in urban settings, with the transportation sector often being widely recognized as one of the principal causes of this issue. Nevertheless, throughout the period after the quarantine, a remarkable decrease in air quality was observed characterized by distinct seasonal patterns, in contrast to previous years. This finding demonstrates a significant correlation between changes in human mobility patterns and their influence on the air quality of urban areas. It also emphasizes the need to use air pollution modeling as a fundamental tool to evaluate and understand these linkages to support long-term plans for reducing air pollution. To obtain a more quantitative understanding, we then employed cutting-edge machine learning methods, such as random forest and long short-term memory algorithms, to accurately determine the effect of the lockdown on PM2.5 levels. Our models' results demonstrated remarkable efficacy in assessing the pollutant concentration in Mashhad during lockdown measures. The test set yielded an R-squared value of 0.82 for the long short-term memory network model, whereas the random forest model showed a calculated cross-validation R-squared of 0.78. The required computational cost for training the LSTM and the RF models across all data was 25 min and 3 s, respectively. In summary, through the integration of statistical methods and machine learning, this research attempts to provide a comprehensive understanding of the impact of human interventions on air quality dynamics.

Crop residue burning increased during the COVID-19 lockdown: A case study of rural India.

The customary practice of crop residue burning (CRB) is a major policy concern across several developing economies because of the associated increase in air pollution and reduction in soil quality. CRB poses a hazard to public health and sustainable farmland management. We collected original survey data from a panel of 400 wheat farmers on CRB choices during April-May of 2019 and 2020 - with the latter coinciding with India's COVID-19 nationwide lockdown. This timeline of events facilitated a unique identification of changes in CRB that are attributable to the lockdown. Several studies find that lockdowns during 2020 had beneficial effects on the environment owing to reduced economic activity. However, our findings indicate that CRB may have unintentionally increased during the lockdown. A binary variable regression framework analyzes the determinants of CRB choices of farmers over two years. We control for farmers' opinions on various socioeconomic aspects of the pandemic lockdown to examine its effects on their CRB decisions. The lockdown significantly increased the likelihood of CRB by up to 12%. Furthermore, farmers who lost agricultural income and those compelled to sell assets during the lockdown were 22% and 19% more inclined, respectively, to choose CRB. Labor mobility ceased during the lockdown and increased the cost of environmentally friendly farmland management; this increased the likelihood of CRB by 6%. This study contributes to a growing literature on the unintentional consequences of pandemic lockdowns.

[Impacts of Anthropogenic Emission Reduction on Urban Atmospheric Oxidizing Capacity During the COVID-19 Lockdown].

In recent years， regional compound air pollution events caused by fine particles （PM2.5） and ozone （O3） have occurred frequently in economically developed areas of China， in which atmospheric oxidizing capacity （AOC） has played an important role. In this study， the WRF-CMAQ model was used to study the impacts of anthropogenic emission reduction on AOC during the COVID-19 lockdown period. Three representative cities in eastern China （Shijiazhuang， Nanjing， and Guangzhou） were selected for an in-depth analysis to quantify the contribution of meteorology and emissions to the changes in AOC and oxidants and to discuss the impact of AOC changes on the formation of secondary pollutants. The results showed that， compared with that in the same period in 2019， the urban average AOC in Shijiazhuang， Nanjing， and Guangzhou in 2020 increased by 60%， 48.7%， and 12.6%， respectively. The concentrations of O3， hydroxyl radical （·OH）， and nitrogen trioxide （NO3·ï¼‰ increased by 1.6%-26.4%， 14.8%-73.3%， and 37.9%-180%， respectively. The AOC in the three cities increased by 0.06×10-4， 0.12×10-4， and 0.33×10-4 min-1， respectively， due to emission reduction. The meteorological change increased AOC in Shijiazhuang and Nanjing by 20% and 17.9%， respectively， but decreased AOC in Guangzhou by -9.3%. Enhanced AOC led to an increase in the nitrogen oxidation ratio （NOR） and VOCs oxidation ratio （VOR） and promoted the transformation of primary pollutants to secondary pollutants. This offset the effects of primary emission reduction and resulted in a nonlinear decline in secondary pollutants compared to emissions during the COVID-19 lockdown.

Usage and attitude of medical students towards mobile medical applications during and after COVID-19 lockdown: repeated cross-sectional study.

BACKGROUND: COVID-19 pandemic has accelerated the shift toward e-learning, particularly in medical education. Mobile medical applications (apps) have become integral tools for e-learning due to the prevalence of smartphones among medical students. Therefore, we aim to assess the usage and attitude of undergraduate Egyptian medical students towards mobile medical apps during and after the COVID-19 lockdown. METHODS: This is a two-phase repeated cross-sectional study using an online, pilot-tested, and self-administered survey conducted at the Faculty of Medicine, Menoufia University, Egypt. Phase 1 was during the academic year 2019-2020 (during lockdown), and phase 2 was during the academic year 2021-2022 (after lockdown). Out of the 4800-target population for each phase, a sample size of 140 medical students was randomly selected from each study year, resulting in a total sample size of 840 students for all six academic and clinical years for each phase. RESULTS: A total of 566 students in phase 1 and 616 students in phase 2 responded to the survey, with response rates of 67.62% and 73.33%, respectively. In phase 1, 55.7% of students reported using medical apps, with no significant difference between males and females (60.1% vs. 53.8%; p = 0.17) or between academic and clinical years (56.3% vs. 54.7%; p = 0.7). In phase 2, the percentage increased to 70.9%, with a significant difference between males and females (80% vs. 62.9%; p < 0.001) and between academic and clinical years (79.8% vs. 63%; p < 0.001). Medical dictionaries were the most commonly used apps, whereas medical calculators were the least common in both phases. Regarding their attitude, most students (65.1% and 73.9% in phases 1 and 2, respectively) expressed confidence in using medical apps, while 81.3% in phase 1 and 88.1% in phase 2 agreed that using medical apps is a flexible method of learning. Lack of knowledge regarding which app to download was the most reported cause of limitation in medical app usage by 37.8% of the students in phase 1 and 40% in phase 2. CONCLUSION: Our study revealed that the COVID-19 lockdown led to a significant increase in the use of mobile medical apps among Egyptian medical students. Despite the positive attitude of students towards these apps, multiple challenges still need to be addressed to ensure their optimal utilization in medical education.

Effect of COVID-19 on sexual function and activities among reproductive-age women in Ibadan, South-West Nigeria.

Background: Since the outbreak of COVID-19 disease, the environment, families, individuals, and their ways of living have been affected. Social distancing was one of the strategies for the prevention of SARS-CoV-2 infection. It led to limited social interactions for fear of contracting the infection, which ultimately affected relationships, among which is sexual health. Aim: To determine the risk of female sexual dysfunction and the effect of the COVID-19 pandemic on sexual function and activities among women of reproductive age in Ibadan, South-West Nigeria. Methods: This cross-sectional study of 218 reproductive-age women evaluated the sexual function before, during, and after the COVID-19 disease pandemic and lockdown. Pretested semistructured self-administered questionnaires with the Female Sexual Function Index (FSFI) were used for data collection. Information collected included sociodemographic and gynecologic characteristics and COVID-19 experiences, as well as sexual history and function before, during, and after the COVID-19 pandemic lockdown. The level of significance was set at P < .05. Outcomes: Respondents were aged 20 to 50 years (95%) with a mean ± SD age of 34.82 ± 8.52 years; the majority were married (75.58%); one-fifth (21.9%) tested positive for COVID-19 infection; and participants who tested positive for COVID-19 infections were mostly health care workers. Results: An absence of sexual activity was reported in 9.18% of participants during lockdown, 7.73% before lockdown, and 4.18% after lockdown. The risk of female sexual dysfunction was prevalent among participants, especially those who tested positive for COVID-19 infection. The prevalence was worse during the pandemic lockdown (53.57%) than before (48.39%) or after (51.61%), and a similar pattern was seen among those who tested negative. There was no statistically significant difference in risk of developing sexual dysfunction during the COVID-19 pandemic between those who tested positive and negative to COVID-19. The arousal and desire domains contributed the highest proportion of low FSFI scores. Clinical Implications: Nationwide lockdowns, which may be a method of control for pandemics, may result in psychosocial complications such as female sexual dysfunction. Strength and Limitations: Most respondents had tertiary education and were able to respond to self-administered questionnaires, yet the risk of recall bias remains a concern whereas the pandemic met the world unprepared and baseline FSFI prior the pandemic was not available for participants. There are no local validation studies for the FSFI in Nigeria, which could have aided interpretation of results. Conclusion: A low FSFI score is prevalent in Ibadan, South-West Nigeria, with a higher incidence reported during the COVID-19 pandemic lockdown.