Design of illumination system using characterized illuminances for smartphone-based fundus camera.

Recently, smartphone-based fundus camera (SBFC) research has been actively conducted in response to the need to expand medical infrastructure in underdeveloped countries and the increased telemedicine since the COVID-19 pandemic. Compared to the conventional table-top system, SBFCs have technical challenges that make it difficult to guarantee uniform illumination and avoid back-reflection because of the design constraints of minimizing the form factor and cost. This paper proposes a novel illumination design methodology using characterized illuminance to obtain high-quality fundus images for SBFCs. Key performance indicators (KPIs), such as retinal uniformity, back-reflection suppression, and optical efficiency, were defined to evaluate the performance of the illumination system. Each KPI was calculated using optical simulation software based on Monte-Carlo ray tracing and mapped into a normalized three-dimensional coordinate, the retinal illumination performance space (RIPS). In RIPS, the KPIs are combined into a single parameter ΔRIPS, which is the quantitative difference evaluated as the Euclidean distance between the ideal and actual design point. A compact SBFC illumination system with five design variables was presented to verify the proposed methodology. The final design values at the minimum ΔRIPS were determined using the Taguchi method and response surface methodology. Finally, a working prototype was built, and fundus images were acquired by clinical testing under institutional review board approval. The fundus image had sufficient brightness and resolution to diagnose the lesion with a viewing angle of approximately 50° in one shot.

Immunosenescence in Caenorhabditis elegans.

Immunosenescence is an age-dependent decline in immune functions and hallmark of aging in diverse species, ranging from invertebrates to mammals. However, identifying the factors responsible for immunosenescence is challenging because of the complexity of immune systems and aging in mammals. The roundworm Caenorhabditis elegans is suitable for understanding immunosenescence because of its simple immune system and rapid aging process. In this review, we discuss the advances in our understanding of immunosenescence in C. elegans. PMK-1/p38 mitogen-activated protein kinase (MAPK), SKN-1/NRF, and ZIP-10/bZIP transcription factor regulate immunosenescence through p38 MAPK and insulin/IGF-1 signaling pathways. Because these factors and pathways are evolutionarily conserved, the findings discussed in this review may help understand the mechanisms underlying immunosenescence and develop new treatment therapy for immunosenescence in humans.

Association of Sociodemographic and Psychosocial Factors With COVID-19-Related Post-Traumatic Stress Disorder Risk Group Among Medical Students.

OBJECTIVE: Several previous studies have reported the negative psychological impact of the coronavirus disease (COVID-19) pandemic on medical students worldwide. This study investigated the sociodemographic and psychosocial factors associated with COVID-19-related post-traumatic stress disorder (PTSD) risk among medical students in Daegu, a region that experienced a high concentration of infections. METHODS: A total of 270 students completed the self-reported questionnaires including COVID-19 exposure, psychological measurement, and sociodemographic factors. We evaluated the COVID-19-related PTSD risk group using the Korean version of the Impact of Event Scale-Revised. Logistic regression analysis was performed to evaluate the odds ratio for the COVID-19-related PTSD risk group in sociodemographic and psychosocial factors. RESULTS: The prevalence of the COVID-19-related PTSD risk group was 10.4% in medical students. Among sociodemographic factors, lower grades (specially, first-year medical students) and current smokers were associated with the COVID-19-related PTSD risk. Indirect exposure to COVID-19 was also associated with this risk. Meanwhile, having higher resilience, self-esteem, and social support were less likely to be associated with COVID-19-related PTSD risk. CONCLUSION: This study suggested that it is necessary to develop a system for the screening and managing of COVID-19-related PTSD risk group among medical students, especially high-risk groups during the COVID-19 pandemic.

Spatial and Temporal Variations in Atmospheric Ventilation Index Coupled with Particulate Matter Concentration in South Korea

The spatiotemporal variations in the atmospheric ventilation index (AVI) with the particulate matter (PM) concentrations in South Korea were investigated using a regional grid model derived from the National Center for AgroMeteorology and PM10 concentration data obtained from AirKorea and the Korea Meteorological Administration. To construct a high-resolution AVI database with 1 h time intervals and a spatial resolution of approximately 2.4 km, a medium-range prediction was performed using a regional model twice a week from December 2018 to November 2019. The resultant dataset was used to explore the seasonal patterns of the areal distribution of a novel index: Ventilation Index coupled with PM (VIP), defined by the ratio of the AVI to PM. To determine the effects of geography on the VIP, diurnal variations of the VIP were examined at three major cities in South Korea. The emphasis of the investigation was on major cities that are planned to be developed into smart cities. This study reveals the specific spatiotemporal structure of the AVI in South Korea for the first time at a high resolution and introduced the potential usefulness of the VIP. The results provide insights that could aid decision making for determining favorable locations for better air-quality cities on an annual basis and can enable the sustainable management of fine PM in and around the areas of interest.

Changes in Passengers’ Travel Behavior Due to COVID-19

The COVID-19 outbreak in 2020 has changed the way people travel due to its highly contagious nature. In this study, changes in the travel behavior of passengers due to COVID-19 in the first half of 2020 were examined. To determine whether COVID-19 has affected the use of transportation by passengers, paired t-tests were conducted between the passenger volume of private vehicles in Seoul prior to and after the pandemic. Additionally, the passenger occupancy rate of different modes of transportation during the similar time periods were compared and analyzed to identify the changes in monthly usage rate for each mode. In the case of private vehicles and public bicycles, the usage rates have recovered or increased when compared to those of before the pandemic. Conversely, bus and rail passenger service rates have decreased from the previous year before the pandemic. Furthermore, it is found that existing bus and rail users have switched to the private auto mode due to COVID-19. Based on the results, traffic patterns of travelers after the outbreak and implications responding to the pandemic are discussed.

Concanavalin A targeting N-linked glycans in spike proteins influence viral interactions.

Lectins, which exhibit viral-interaction abilities, have garnered attention in the current pandemic era as potential neutralizing agents and vaccine candidates. Viral invasion through envelope proteins is modulated by N-linked glycosylation in the spike (S) protein. This study demonstrates the biophysical aspects between lectins and high-mannose and -galactose N-glycans to provide insights into binding events.

Rugosic acid A, derived from Rosa rugosa Thunb., is novel inhibitory agent for NF-κB and IL-6/STAT3 axis in acute lung injury model.

Rosa rugosa Thunb., is as a medicinal plant known for anti-diabetic, and anti-inflammatory activities. However, the specific active compounds responsible for the individual pharmacological effects of in R. rugosa extract (95% EtOH) remain unknown. Here, we hypothesized that terpenoid structure, the most abundant constituents in R. rugosa extract, are responsible for its anti-inflammatory activity. We investigated the phytochemical substituents (compounds 1-13) and newly purified 11-methoxy polisin A, and 13-methoxy bisaborosaol F using NMR and ESI-MS and to screened their effects on NO production in LPS-induced macrophages. Rugosic acid A (RA) induced to ameliorate NO production, iNOS, and pro-inflammatory cytokines associated with the NF-κB. And, RA suppressed IL-6 secretion and IL-6-mediated STAT3 activation in LPS-mediated inflammation. In addition, RA was evaluated in LPS-mediated acute lung injury (ALI) model similar to acute pneumonia. Our results suggested that RA was suppressed to translocate nuclear NF-κB and IL-6-mediated STAT3 activation. Finally, RA led to amelioration of ALI by decreasing myeloperoxidase (MPO) and inhibiting phosphorylation of NF-κB and STAT3. Our group originally found that R. rugosa extract had new methoxy compounds and RA may be alternative natural agent for acute pneumonia similar to severe acute respiratory syndrome by coronavirus.