Accelerated aging phenotypes in the retinal pigment epithelium of Zmpste24-deficient mice.

Age-related macular degeneration (AMD) is a chronic and progressive disease characterized by degeneration of the retinal pigment epithelium (RPE) and retina that ultimately leads to loss of vision. The pathological mechanisms of AMD are not fully known. Cellular senescence, which is a state of cell cycle arrest induced by DNA-damage or aging, is hypothesized to critically affect the pathogenesis of AMD. In this study, we examined the relationship between cellular senescence and RPE/retinal degeneration in mouse models of natural aging and accelerated aging. We performed a bulk RNA sequencing of the RPE cells from adult (8 months old) and naturally-aged old (24 months old) mice and found that common signatures of senescence and AMD pathology - inflammation, apoptosis, and blood vessel formation - are upregulated in the RPE of old mice. Next, we investigated markers of senescence and the degree of RPE/retinal degeneration in Zmpste24-deficient (Zmpste24-/-) mice, which is a model for progeria and accelerated aging. We found that Zmpste24-/- mice display markedly greater level of senescence-related markers in RPE and significant RPE/retinal degeneration compared to wild-type mice, in a manner consistent with natural aging. Overall, these results provide support for the association between cellular senescence of RPE and the pathogenesis of AMD, and suggest the use of Zmpste24-/- mice as a novel senescent RPE model of AMD.

Effectiveness of negative pressure isolation stretcher and rooms for SARS-CoV-2 nosocomial infection control and maintenance of South Korean emergency department capacity.

OBJECTIVE: There are growing concerns regarding the lack of COVID-19 pandemic response capacity in already overwhelmed emergency departments (EDs), and lack of proper isolation facilities. This study evaluated the effectiveness of the negative pressure isolation stretcher (NPIS) and additional negative pressure isolation rooms (NPIRs) on the maintenance of emergency care capacity during the COVID-19 outbreak. METHODS: A before and after intervention study was performed between February 27, 2020 and March 31, 2020 at the ED of Chungbuk National University Hospital, Cheongju, South Korea. A total of 2455 patients who visited the ED during the study period were included. Interventions included the introduction of the NPIS and additional NPIRs in the ED. The main outcome of the study was frequency of medical cessation. Secondary outcomes were the average number of ED visits and lengths of stay. RESULTS: After the intervention, average frequency of medical cessation was significantly decreased from 1.6 times per day (range 0-4) in the pre-intervention period to 0.6 times per day (range 0-3) in the post-intervention period (p-value <0.01). On the other hand, the number of patients visiting the ED increased significantly from 67.2 persons per day (range 58-79) pre-intervention to 76.3 persons per day (range 61-88) post-intervention (p value <0.01). However, there were no statistically significant differences in the average ED length of stay across the study phases (p value = 0.50). CONCLUSIONS: This intervention may provide an effective way to prepare and meet the ED response needs of the COVID-19 pandemic.

Corrosion behavior of Ti-Pt-coated stainless steel for bipolar plates in polymer electrolyte membranes under water electrolysis conditions.

In this study, the corrosion behavior and degradation mechanism of Ti-Pt-coated stainless steel bipolar plates were investigated through electrochemical tests and surface analysis in a polymer electrolyte membrane water electrolysis (PEMWE) operating environment. The coated bipolar plate has a corrosion current density of only 1.68 × 10-8 A/cm2, which is an order of magnitude lower than that of the bare SS316L substrate (1.94 × 10-7 A/cm2), indicating that its corrosion resistance is superior to that of bare SS316L substrate. However, in the PEMWE operating environment, the protection efficiency of the coating and the corrosion resistance of the coated bipolar plate decreased. The degradation of the coated bipolar plate can be attributed to electrolyte penetration into the blistering areas of the coating layer with micro voids. Defects in the coating layer occur because of the pressure of oxygen gas generated within the coating layer under high-potential conditions, thereby exposing the substrate to the electrolyte and corrosion.

Vutiglabridin exerts anti-ageing effects in aged mice through alleviating age-related metabolic dysfunctions.

BACKGROUND: Ageing alters the ECM, leading to mitochondrial dysfunction and oxidative stress, which triggers an inflammatory response that exacerbates with age. Age-related changes impact satellite cells, affecting muscle regeneration, and the balance of proteins. Furthermore, ageing causes a decline in NAD+ levels, and alterations in fat metabolism that impact our health. These various metabolic issues become intricately intertwined with ageing, leading to a variety of individual-level diseases and profoundly affecting individuals' healthspan. Therefore, we hypothesize that vutiglabridin capable of alleviating these metabolic abnormalities will be able to ameliorate many of the problems associated with ageing. METHOD: The efficacy of vutiglabridin, which alleviates metabolic issues by enhancing mitochondrial function, was assessed in aged mice treated with vutiglabridin and compared to untreated elderly mice. On young mice, vutiglabridin-treated aged mice, and non-treated aged mice, the Senescence-associated beta-galactosidase staining and q-PCR for ageing marker genes were carried out. Bulk RNA-seq was carried out on GA muscle, eWAT, and liver from each group of mice to compare differences in gene expression in various gene pathways. Blood from each group of mice was used to compare and analyze the ageing lipid profile. RESULTS: SA-ß-gal staining of eWAT, liver, kidney, and spleen of ageing mice showed that vutiglabridin had anti-ageing effects compared to the control group, and q-PCR of ageing marker genes including Cdkn1a and Cdkn2a in each tissue showed that vutiglabridin reduced the ageing process. In aged mice treated with vutiglabridin, GA muscle showed improved homeostasis compared to controls, eWAT showed restored insulin sensitivity and prevented FALC-induced inflammation, and liver showed reduced inflammation levels due to prevented TLO formation, improved mitochondrial complex I assembly, resulting in reduced ROS formation. Furthermore, blood lipid analysis revealed that ageing-related lipid profile was relieved in ageing mice treated with vutiglabridin versus the control group. CONCLUSION: Vutiglabridin slows metabolic ageing mechanisms such as decreased insulin sensitivity, increased inflammation, and altered NAD+ metabolism in adipose tissue in mice experiments, while also retaining muscle homeostasis, which is deteriorated with age. It also improves the lipid profile in the blood and restores mitochondrial function in the liver to reduce ROS generation.

Effects of Occupational Stress and Health Behaviors on Heart Rate Variability in Live-Fire Instructors.

OBJECTIVES: This study aimed to identify the association between the healthrelated characteristics and the subscales of occupational stress of live fire instructors and heart rate variability (HRV). METHODS: We conducted questionnaire survey on a general health checkup for 15 live fire instructors. Occupational stress and HRV parameters were measured to determine the association between health behavior, including smoking, drinking, exercise, and sleep-related disorders, and occupational stress of live fire instructors and HRV parameters using Spearman's rank correlation coefficient. RESULTS: Smoking, insomnia, and job insecurity, a subscale of occupational stress measurement, showed negative Spearman rank correlations with HRV. CONCLUSIONS: Insomnia, smoking, and job insecurity (due to occupational stress) among live fire instructors were associated with decreased HRV.

Preliminary study of Internet addiction and cognitive function in adolescents based on IQ tests.

The potential relationship between Internet addiction and certain cognitive function problems has been suggested by several studies. However, few or no studies have examined the differences in cognitive functioning between persons addicted to the Internet and persons not addicted using a standard neuropsychological test. This study screened 253 middle school students and 389 high school students for Internet addiction and compared 59 Internet-addicted students with 43 non-addicted students using an IQ test. The Internet-addicted group had comprehension sub-item scores that were significantly lower than those of the non-addicted group. As the comprehension item reflects ethical judgement and reality testing, there may be a relationship between Internet addiction and weak social intelligence. Earlier onset of Internet addiction and longer addiction duration were associated with lower participant performance in areas related to attention. As this study is a cross-sectional study, it is not clear whether the persons who display weak cognitive functioning are susceptible to Internet addiction or if Internet addiction causes cognitive problems. However, as brain development remains active during adolescence, the possibility that Internet addiction adversely affects the cognitive functioning of adolescents cannot be ruled out.

Comparison of the epidemiology and injury profile among injured patients involved in special purpose vehicle-related incidents in South Korea.

Injuries caused by mobile machinery or special purpose vehicles (SPVs) can lead to high socio-medical cost and fatality. In this descriptive study, we compared the epidemiology and injury profile of injured patients involved in SPVs-related incidents. We analyzed a nationwide database of SPV-related injured patients between January 2011 and December 2016. Injured patients were classified into three groups: pedestrian, motor vehicle occupant (MVO), and SPV operator groups. Of 1,419 cases, the highest number of SPV-related injured patients were found in the age group 40-59 years (671 cases, 47.3%) and at transport area (771 cases, 54.3%). The injury was most severe in the SPV operator group. The lower extremities were the most common fracture site, and intrathoracic injury was the most common visceral regions for SPV-related injured patients. SPV operator could lead to fatal intrathoracic injuries.

Electrochemical properties of size-controllable polypyrrole/porous carbon for supercapacitor electrodes.

Polypyrrole (PPy)/activated carbon (AC) composite (SPPyC) with different PPy particle size are prepared without formation of chemical bonding between PPy and AC. The PPy particles were deposited on AC by miniemulsion polymerization and the size of PPy particles could be controlled by different surfactant amounts. The surface characteristics of SPPyC were characterized by Fourier transform infrared spectroscopy (FT-IR). The morphology of SPPyC was examined by scanning electron microscopy (SEM). The electrochemical performance of SPPyC was determined by cyclic voltammetry (CV) and galvanostatic charge/discharge characteristics in 6 M KOH electrolyte. The specific capacitances of SPPyC were higher than those of AC and the highest specific capacitance (125 F/g) of the S3PPyC was obtained at a current density of 0.5 A/g. This improved electrochemical performance of SPPyC was attributed to redox reaction by controlled PPy particle size.