Influenza A virus (IAV) infection contributes to high annual morbidity and mortality, thus necessitating measures aimed at protecting against the disease. Alcohol-based disinfectants are commonly used to inactivate IAV, but they have several undesirable properties. In search of other means which would inactivate IAV, we focused on the effect of alkaline solutions on IAV. We found the viral infectivity remarkably decreased with treatment of an alkaline solution at pH 12.0 for 1 min, where destruction of the viral spikes was observed using an electron microscope. A more detailed examination revealed that the infectivity of IAV was remarkedly reduced by brief treatment with the alkaline solution at pH 11.75 or above, most likely due to the degradation of viral hemagglutinin protein. These results show that at a high pH, the haemagglutinin protein is degraded, resulting in very rapid inactivation of IAV.

The coronavirus disease 2019 (COVID-19) pandemic has decreased bystander cardiopulmonary resuscitation (BCPR) intervention rates. The purpose of this study was to elucidate the willingness of university freshmen to provide BCPR during the COVID-19 pandemic and the predictors thereof. A cross-sectional survey of 2789 newly enrolled university students was conducted after the end of the sixth wave of the COVID-19 epidemic in Japan; predictors of willingness to provide BCPR were assessed by regression analysis. Of the 2534 participants 1525 (60.2%) were willing to intervene and provide BCPR during the COVID-19 pandemic. Hesitancy due to the anxiety that CPR intervention might result in poor prognosis was a negative predictor of willingness. In contrast, anxiety about the possibility of infection during CPR intervention did not show a negative impact. On the other hand, interest in CPR and willingness to participate in a course, confidence in CPR skills, awareness of automated external defibrillation, and knowledge of CPR during the COVID-19 pandemic, were also positive predictors. This study suggests that the barrier to willingness to intervene with BCPR during a COVID-19 pandemic is not fear of infection, but rather hesitation due to the possibility of poor prognosis from the intervention. The significance of conducting this study during the COVID-19 epidemic is great, and there is an urgent need for measures to overcome hesitation regarding BCPR.

Background: Elevated global temperatures increase the risk of heat-stroke among athletes exercising in hot conditions. Japanese high school baseball tournaments occur during peak summer, raising concerns regarding heat-related health issues. We examined whether the color of footwear and legwear affects lower-limb temperature, exploring approaches to prevent heat-related health problems. Methods: Eight mannequin legs were fitted with shoes, socks, and baseball stirrup socks in white or black combinations. Plantar and shin surface temperatures were recorded for 120 min on both dirt and artificial turf at wet-bulb globe temperatures above 30 °C and compared across color combinations. Reflectance spectra of shin legwear were also measured. Results: Plantar and shin surface temperatures increased under all conditions. On the dirt field, mannequins wearing all-black gear (shoe, sock, and baseball stirrup sock) exhibited plantar temperatures exceeding 45 °C and shin temperatures over 50 °C. The highest shin temperature occurred with the white shoe/black baseball stirrup sock combination. Temperature increases were smaller for all-white items compared with all-black items. Reflectance spectra showed that white baseball stirrup socks strongly reflected both visible and infrared light. Conclusions: Footwear and legwear color significantly influence lower-limb temperature increases during baseball games in summer heat, especially when wearing all-black items. White gear may help prevent heat-related health problems and improve performance in baseball and other outdoor sports.

Since the novel coronavirus disease 2019 (COVID-19) pandemic, educational institutions have implemented measures such as school closures, raising concerns regarding the increase in psychological distress among university students. The purpose of this study is to identify factors that have influenced psychological distress among college freshmen during the COVID-19 pandemic. A questionnaire survey was conducted at the conclusion of the sixth wave of COVID-19 in Japan. Psychological distress was measured using the six-item Kessler Psychological Distress Scale (K6). Factors affecting psychological distress were calculated using regression analysis. Of the 2536 participants, 1841 (72.6%) reported having no psychological distress, while 695 (27.4%) reported having psychological distress. Factors that were identified to contribute to psychological distress were lack of sleep, weight gain or loss, worsening of interpersonal relationships, and physical symptoms and illnesses. A willingness to join an athletic club and having an environment in which it is easy to discuss worries and anxieties with others were factors that were identified to hinder psychological distress. It is necessary for universities to offer enhanced supports for physical and interpersonal activities. Additionally, it is imperative to encourage students to look after their physical health and to actively utilize university-based consultation systems.

Background: University students’ awareness of oral health plays an important role in lifelong health promotion. However, the factors influencing this awareness among Japanese university students are not fully understood. This study aimed to comprehensively examine and analyze Japanese university students’ perceptions of their oral health status, self-reported oral symptoms, and oral health-related behaviors. Methods: A cross-sectional survey was conducted among undergraduate students using an anonymous online questionnaire to collect information on their basic attributes and self-reported items related to oral health status, oral health behavior, and lifestyle habits. The chi-square test and logistic regression analysis were used to examine factors associated with oral health status. Results: A total of 5482 students participated in this study. Overall, 75.9% of the respondents reported that their oral health was good. Factors significantly associated with good oral health were the absence of dental caries and periodontal disease, tooth brushing at least twice a day, regular dental visits, conscious toothpaste selection, and lack of concern about dental care costs and pain during treatment. Conclusions: Oral diseases and symptoms, oral health behaviors, and psychosocial factors were strongly associated with university students’ awareness of their oral health. Since oral health is closely related to systemic health, it is essential to promote proper oral hygiene practices at an early age. Therefore, providing oral health education for university students may contribute to lifelong health promotion and prevention of systemic diseases.