Numerical Sensitivity Tests of Volatile Organic Compounds Emission to PM2.5 Formation during Heat Wave Period in 2018 in Two Southeast Korean Cities

A record-breaking severe heat wave was recorded in southeast Korea from 11 July to 15 August 2018, and the numerical sensitivity simulations of volatile organic compound (VOC) to secondarily generated particulate matter with diameter of less than 2.5 mu m (PM2.5) concentrations were studied in the Busan and Ulsan metropolitan areas in southeast Korea. A weather research and forecasting (WRF) model coupled with chemistry (WRF-Chem) was employed, and we carried out VOC emission sensitivity simulations to investigate variations in PM2.5 concentrations during the heat wave period that occurred from 11 July to 15 August 2018. In our study, when anthropogenic VOC emissions from the Comprehensive Regional Emissions Inventory for Atmospheric Transport Experiment-2015 (CREATE-2015) inventory were increased by approximately a factor of five in southeast Korea, a better agreement with observations of PM2.5 mass concentrations was simulated, implying an underestimation of anthropogenic VOC emissions over southeast Korea. The simulated secondary organic aerosol (SOA) fraction, in particular, showed greater dominance during high temperature periods such as 19-21 July, 2018, with the SOA fractions of 42.3% (in Busan) and 34.3% (in Ulsan) among a sub-total of seven inorganic and organic components. This is considerably higher than observed annual mean organic carbon (OC) fraction (28.4 +/- 4%) among seven components, indicating the enhancement of secondary organic aerosols induced by photochemical reactions during the heat wave period in both metropolitan areas. The PM2.5 to PM10 ratios were 0.69 and 0.74, on average, during the study period in the two cities. These were also significantly higher than the typical range in those cities, which was 0.5-0.6 in 2018. Our simulations implied that extremely high temperatures with no precipitation are significantly important to the secondary generation of PM2.5 with higher secondary organic aerosol fraction via photochemical reactions in southeastern Korean cities. Other possible relationships between anthropogenic VOC emissions and temperature during the heat wave episode are also discussed in this study

How lessons learned from the 2015 Middle East respiratory syndrome outbreak affected the response to coronavirus disease 2019 in the Republic of Korea

The Republic of Korea (ROK) experienced a public health crisis due to Middle East respiratory syndrome (MERS) in 2015 and is currently going through the coronavirus disease 2019 (COVID-19) pandemic. Lessons learned from the disastrous MERS outbreak were reflected in the preparedness system, and the readiness capabilities that were subsequently developed enabled the country to successfully flatten the epidemic curve of COVID-19 in late February and March 2020. In this review, we summarize and compare the epidemiology and response of the ROK to the 2015 MERS outbreak and the COVID-19 epidemic in early 2020. We emphasize that, because further COVID-19 waves seem inevitable, it is urgent to develop comprehensive preparedness and response plans for the worst-case scenarios of the COVID-19 pandemic. Simultaneously strengthening healthcare capacity to endure the peak demand and implementing smart strategies to sustain social distancing and public hygiene are necessary until safe and effective therapeutics and vaccines against COVID-19 are available.Peer reviewe

Acidic pH shock induces the expressions of a wide range of stress-response genes

<p>Abstract</p> <p>Background</p> <p>Environmental signals usually enhance secondary metabolite production in <it>Streptomycetes </it>by initiating complex signal transduction system. It is known that different sigma factors respond to different types of stresses, respectively in <it>Streptomyces </it>strains, which have a number of unique signal transduction mechanisms depending on the types of environmental shock. In this study, we wanted to know how a pH shock would affect the expression of various sigma factors and shock-related proteins in <it>S. coelicolor </it>A3(2).</p> <p>Results</p> <p>According to the results of transcriptional and proteomic analyses, the major number of sigma factor genes were upregulated by an acidic pH shock. Well-studied sigma factor genes of <it>sigH </it>(heat shock), <it>sigR </it>(oxidative stress), <it>sigB </it>(osmotic shock), and <it>hrdD </it>that play a major role in the secondary metabolism, were all strongly upregulated by the pH shock. A number of heat shock proteins including the DnaK family and chaperones such as GroEL2 were also observed to be upregulated by the pH shock, while their repressor of <it>hspR </it>was strongly downregulated. Oxidative stress-related proteins such as thioredoxin, catalase, superoxide dismutase, peroxidase, and osmotic shock-related protein such as vesicle synthases were also upregulated in overall.</p> <p>Conclusion</p> <p>From these observations, an acidic pH shock was considered to be one of the strongest stresses to influence a wide range of sigma factors and shock-related proteins including general stress response proteins. The upregulation of the sigma factors and shock proteins already found to be related to actinorhodin biosynthesis was considered to have contributed to enhanced actinorhodin productivity by mediating the pH shock signal to regulators or biosynthesis genes for actinorhodin production.</p

Prevalence of sarcopenia and sarcopenic obesity in Korean adults: The Korean Sarcopenic Obesity Study (KSOS)

*Context:* Sarcopenic obesity (SO), a combination of excess weight and reduced muscle mass and/or strength, is suggested to be associated with an increased risk of adverse health outcomes. &#xd;&#xa;*Objectives:* To examine the prevalence and characteristics of Sarcopenic and SO defined by using different indices such as Appendicular Skeletal muscle Mass (ASM)/height^2^ and Skeletal Muscle Index (SMI (%): skeletal muscle mass (kg)/weight (kg) &#xd7; 100) for Korean adults. &#xd;&#xa;*Methods:* 591 participants were recruited from the Korean Sarcopenic Obesity Study (KSOS) which is an ongoing prospective observational cohort study. Analysis was conducted in 526 participants (328 women, 198 men) who had complete data on body composition using Dual X-ray absorptiometry and computed tomography. &#xd;&#xa;*Results:* The prevalence of sarcopenia and SO increases with aging. Using two or more standard deviations (SD) of ASM/height^2^ below reference values from young, healthy adults as a definition of sarcopenia, the prevalence of sarcopenia and SO was 6.3% and 1.3% in men and 4.1% and 1.7% in women over 60 years of age. However, using two or more SD of SMI, the prevalence of sarcopenia and SO was 5.1% and 5.1% respectively in men and 14.2% and 12.5% respectively in women. As defined by SMI, subjects with SO had 3 times the risk of metabolic syndrome (OR = 3.03, 95% confidence interval (CI) = 1.26-7.26) and subjects with non-sarcopenic obesity had approximately 2 times the risk of metabolic syndrome (OR = 1.89, 95% CI = 1.18-3.02) compared with normal subjects. &#xd;&#xa;*Conclusion:* Obese subjects with relative sarcopenia were associated with a greater likelihood for metabolic syndrome. As Koreans were more obese and aging, the prevalence of SO and its impact on health outcomes are estimated to be rapidly grow. Further research is requested to establish the definition, cause and consequences of SO.&#xd;&#xa

Efficacy and safety of daclatasvir and asunaprevir for hepatitis C virus genotype 1b infection

Background/Aims: The treatment strategy for hepatitis C virus (HCV) has been changing rapidly since the introduction of direct-acting antivirals such as daclatasvir (DCV) and asunaprevir (ASV). We evaluated the efficacy and safety of DCV and ASV for HCV in real-life practice. Methods: Patients were treated with 60 mg of DCV once daily plus 200 mg of ASV twice daily for 24 weeks, and followed for 12 weeks. The primary endpoint was a sustained virological response at 12 weeks after treatment (SVR12) and safety. Results: This retrospective study included eight patients with chronic HCV genotype 1b infection. All of the enrolled patients were diagnosed with liver cirrhosis, and their mean age was 65.75 years. One patient was a nonresponder and two patients relapsed with previous pegylated interferon (PegIFN) and ribavirin (RBV) treatment. None of the patient showed NS5A mutation. An SVR12 was achieved in 88% of cases by the DCV and ASV combination therapy. The serum transaminase level and the aspartate-aminotransferase-to-platelet ratio were improved after the treatment. DCV and ASV were well tolerated in most of the patients, with treatment discontinuation due to adverse events (elevated liver enzyme and decompensation) occurring in two patients. Conclusion: In this study, combination of DCV and ASV treatment achieved a high sustained virological response with few adverse events even in those with cirrhosis, advanced age, and nonresponse/relapse to previous interferon-based therapy. Close monitoring of safety issues may be necessary when treating chronic HCV patients receiving DCV and ASV, especially in older patient and those with cirrhosis

Decreased Angiopoietin Expression in Underactive Bladder Induced by Long-term Bladder Outlet Obstruction

Purpose Ischemia of the bladder can occur if neovascular formation cannot keep pace with hypoxia induced by chronic bladder outlet obstruction (BOO). The aim of this study was to examine changes in angiogenesis growth factor expression generated by chronic BOO in a rat model of underactive bladder. Methods Twenty female Sprague-Dawley rats aged 6 weeks were assigned to 4 groups (5 rats per group). Group 1 was the control. Group 2 underwent sham surgery. The rats in groups 3 and 4 underwent BOO and were followed up for 1 week and 8 weeks. Cystometry was carried out together with bladder tissue analysis at 1 week and 8 weeks postoperatively. Real-time polymerase chain reaction (PCR) assays were conducted to determine the expression level of angiogenesis-related growth factors. A hypoxia signaling pathway PCR array was additionally carried out. Results The group that underwent BOO for 8 weeks showed abnormal bladder function, with a diminished intercontraction interval, decreased maximal voiding pressure, and higher volume of residual urine (P<0.05). Hypoxia-inducible factor-1 alpha expression was elevated in this group. The expression levels of vascular endothelial growth factor (VEGF) and VEGF receptor messenger RNA (mRNA) in the BOO group were comparable to those in the control group. However, angiotensin/tie receptor mRNA expression levels increased at 1 week after BOO, but decreased at 8 weeks after BOO. In animals that underwent BOO, fewer blood vessels exhibited positive immunofluorescent staining for von Willebrand factor. Alterations were also seen in the hypoxia signaling pathway PCR array. Conclusions In a rat model of underactive bladder caused by surgical BOO, reduced angiopoietin expression was demonstrated. This observation might underlie visceral ischemia and fibrosis associated with the procedure. The findings of this study might offer an improved understanding of the disease processes underlying BOO and facilitate selection of the appropriate time to repair the organ in this condition