Effects of breccia and water contents on the mechanical properties of fault-core-zone materials.

Determining the mechanical properties of fault-core-zone materials is challenging because of the low strength of such materials, which affects field sampling, specimen preparation, and laboratory testing. We overcame this problem by preparing and testing mechanical properties of 132 artificial fault-core-zone specimens consisting of mixtures of breccia, sand, clay, and water. The unconfined compressive strength (UCS), elastic modulus (E), and penetration resistance value (PRV) of these fault-core-zone materials were measured, and the effects of breccia content and water content on mechanical properties were assessed. Results show that UCS is inversely proportional to breccia content and water content, and that E is inversely proportional to water content. Furthermore, the inverse relationship of UCS with water content varies with breccia content. UCS is proportional to both PRV and E, and the relationship for each varies with breccia content. High coefficients of determination (R2 = 0.62-0.88) between the parameters suggest that breccia content, water content, and PRV are potentially useful parameters for estimating the mechanical properties of fault core zones.

Relationship between chronic exposure to ambient air pollution and mental health in Korean adult cancer survivors and the general population.

BACKGROUND: Although a significant association between air pollution and mental health has been identified, few studies have addressed this relationship based on cancer diagnosis. This study investigated whether associations between long-term air pollution and mental health conditions differ based on whether the individual has been diagnosed with cancer. METHODS: Nationally representative data were used and a total of 38,101 adults were included in the analyses. We assessed mental health factors such as perceived stress, depressive symptoms, and suicidal ideation, and analyzed the associations between these factors and individuals' annual average exposure to air pollutants, including particulate matter with an aerodynamic diameter ≤ 10 µm (PM10), nitrogen dioxide, sulfur dioxide, and carbon monoxide. RESULTS: Compared with the general population, PM10 exposure in cancer survivors predicted a higher risk of depressive symptoms (odds ratio [OR] =1.34; 95% confidence interval [CI] = 1.06-1.69) and suicidal ideation (OR = 1.29; 95% CI = 1.01-1.64). Notably, the statistically significant relationship between PM10 exposure and suicidal ideation in cancer survivors disappeared after further adjustment for depressive symptoms (p = 0.3103). This pattern was also observed in the result of propensity score-matched analysis for comparison between cancer survivors and the general population. CONCLUSIONS: This study provides the first evidence that cancer survivors with depressive symptoms may be more susceptible to suicidal ideation in the context of persistent PM10 exposure.

Flattening the Curve on COVID-19: South Korea's Measures in Tackling Initial Outbreak of Coronavirus.

The spread of coronavirus disease 2019 (COVID-19) is causing an unprecedented crisis around the world, with South Korea being no exception. South Korea experienced a surge of COVID-19 cases on February 19, 2020, but was able to flatten the COVID-19 curve in only 20 days without enforcing lockdown measures that restrict the freedom and movement of people. The actual field experience of the Korean government's COVID-19 response team, who participated in drafting the document "Tackling COVID-19: Health, Quarantine, and Economic Measures: Korean experience," was examined and an in-depth analysis was conducted of the South Korean government's experience dealing with the Middle East respiratory syndrome of 2015. Three prominent factors were identified behind Korea's responses against COVID-19. First, it was crucial that the government responded as 1 team efficiently to cooperate and respond to COVID-19. Second, a novel approach was needed to combat COVID-19 spread. Information and communication technology had a key role in South Korea's strategy to contain COVID-19. Third, an effective response to COVID-19 was possible due to the successful partnership between the general public and state authorities.

Association of Metabolically Healthy Obesity and Future Depression: Using National Health Insurance System Data in Korea from 2009-2017.

(1) Background: The health implications associated with the metabolically healthy obese (MHO) phenotype, in particular related to symptoms of depression, are still not clear. the purpose of this study is to check whether depression and metabolic status are relevant by classifying them into four groups in accordance with the MHO diagnostic standard. Other impressions seen were the differences between sexes and the effects of the MHO on the occurrence of depression. (2) Methods: A sample of 3,586,492 adult individuals from the National Health Insurance Database of Korea was classified into four categories by their metabolic status and body mass index: (1) metabolically healthy non-obese (MHN); (2) metabolically healthy obese (MHO); (3) metabolically unhealthy non-obese (MUN); and (4) metabolically unhealthy obese (MUO). Participants were followed for six to eight years for new incidences of depression. The statistical significance of the general characteristics of the four groups, as well as the mean differences in metabolic syndrome risk factors, was assessed with the use of a one-way analysis of variance (ANOVA). (3) Results: The MHN ratio in women was higher than in men (men 39.3%, women 55.2%). In both men and women, depression incidence was the highest among MUO participants (odds ratio (OR) = 1.01 in men; OR = 1.09 in women). It was concluded as well that, among the risk factors of metabolic syndrome, waist circumference was the most related to depression. Among the four groups, the MUO phenotype was the most related to depression. Furthermore, in women participants, MHO is also related to a higher risk of depressive symptoms. These findings indicate that MHO is not a totally benign condition in relation to depression in women. (4) Conclusion: Therefore, reducing metabolic syndrome and obesity patients in Korea will likely reduce the incidence of depression.

Searching for Digital Technologies in Containment and Mitigation Strategies: Experience from South Korea COVID-19.

Background: Korea has achieved health policy objectives in pandemic management so far, namely minimizing mortality, flattening the epidemic curve, and limiting the socio-economic burden of its measures. The key to the Korean government's success in combating COVID-19 lies with the latest digital technologies (DTs). The prompt and effective application of DTs facilitates both containment as well as mitigation strategies and their sub-policy measures. Methods: This article uses an experiential analysis based on an exploratory case study - analysis on field applications of the government's interventions. Information is collected by qualitative methods such as literature analysis, meeting materials, and a review of various government reports (including internal ones) along with academic and professional experiences of the authors. Findings: The article presents the unique Korean health policy approaches in the COVID-19 crisis. First, DTs allow the Korean government to embrace various policy measures together listed in containment strategy, namely altering and warning, epidemiological investigation, quarantine of contacts, case-finding, social distancing, and mask-wearing. Second, DTs allow Korea to integrate containment and mitigation strategies simultaneously. Along with the above measures in containment, healthcare service, medical treatment, and prophylaxis (presymptomatic testing) within mitigation are utilized to prevent a COVID-19 spread. Conclusions: Korea develops DTs in an integrated manner in the early pandemic stage under strong and coordinated government leadership. Above all, the DTs' functions in each pandemic developmental stage are continuously upgraded. Instead of prioritizing policy measures or strategies, therefore, Korea can implement diverse policies simultaneously by integrating DTs effectively. During the COVID-19 outbreak, DTs work as the enablers to connect these two strategies and their measures in Korea. Recommendations: DTs should be at the center of the disaster management paradigm, especially during a pandemic. DTs are facilitators and integrators of containing and mitigating strategies and their policy measures.

Estimation of the Structural and Geomechanical Anisotropy in Fault Gouges Using 3D Micro-Computed Tomography (µ-CT).

Fault gouges play an important role in the shear deformation of fault zones, by causing weakness and frictional instability in structures. Previous studies have investigated the evolution of shear deformation of fault zones by observing experiments using remolded and synthetic gouge specimens at a micro-scale. However, how the spatial configuration of the rock constituents accounts for the 3D anisotropy of intact structures of fault gouges, particularly at the core-scale, is not well understood. We obtained 3D µ-CT images of directionally cored gouge specimens and performed statistical analysis to quantify the major orientation of the internal structures. Direct shear tests were conducted to investigate the relationship between the distribution of the internal structures and geomechanical behavior. The results show that the undisturbed fault gouge has a clear anisotropy parallel to the fault plane even at the core-scale. Moreover, the direct shear test results show that the frictional resistance of a fault gouge has anisotropy related to the fault plane. The simple, yet robust method proposed in this study confirms that the core-scale structural anisotropy is correlated to the anisotropic shear resistance.

COVID-19 in South Korea: Lessons for developing countries.

South Korea's response is considered by many as one the most effective models against COVID-19. The average number of new cases per day fell to 6.4 in the first week of May and currently 90% of all confirmed cases have fully recovered after a massive outbreak in February 29. First, South Korea has flattened the curve of COVID-19 by combining testing, early isolation, and free treatment of positive cases combined with digital technologies without taking to "lockdown" measures. Second, South Korea has been holding press briefings twice a day and disclosed all information on COVID-19 to the public in an open and transparent manner. Third, South Korea has worked to secure the civic participation and voluntary engagement of citizens and businesses. The South Korean approach to COVID-19 may be difficult to emulate even for countries like the U.S. and U.K., but provides important policy implications for developing countries and needs for strengthening three core competencies against the outbreak of an epidemic: digital technology, efficient health governance, and civic partnership. It is a great challenge for developing countries to fight alone against COVID-19. As such, the international community should work to strengthen these core competencies accordingly.

A genome-wide by PM10 interaction study identifies novel loci for lung function near BICD1 and IL1RN-IL1F10 genes in Korean adults.

Although several genome-wide interaction studies (GWIS) have been performed in specific European populations to understand the missing link between genetic and environmental factors for lung function, GWIS of Asian samples remain rare. Therefore, we performed a GWIS of exposure to air pollution to identify loci for lung function in Korean adult men. A total of 1826 adult men recruited from two health check-up centers were included in the analysis and the annual mean concentrations of ambient particulate matter with an aerodynamic diameter ≤10 µm (PM10) were used. In case of forced vital capacity (FVC), one SNP (rs12312730) that passed our genome-wide threshold of pint < 1 × 10-5 was detected in the intronic region of the BICD1 gene on chromosome 12. In addition, we found two variants (rs6743376 and rs17042888) located near the IL1RN-IL1F10 gene that were involved in the inflammatory response and associated with decreased FVC via interaction with PM10 exposure. A stratified association analysis according to these SNP genotypes showed that PM10 concentrations in subjects with one or two of the risk alleles, compared with those with the non-risk allele, were significantly correlated with a reduction in FVC. This pattern was replicated in another 892 Korean adult samples. The current study reports the first GWIS discovery in an Asian population: the BICD1 and IL1RN-IL1F10 genes may contribute to the decrease in FVC levels by interacting with PM10 exposure.

Association of Ambient Air Pollution with Increased Liver Enzymes in Korean Adults.

An association between exposure to air pollution and liver enzymes in certain areas or older people has been reported in the literature; however, it cannot be generalized to the general population. We investigated the association between air pollution, liver enzyme levels, and alcohol consumption using nationwide data of South Korean adults. Air pollutants included particulate matter with an aerodynamic diameter ≤10 µm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO). Liver enzymes included alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Exposure to air pollutants were significantly associated with elevation of log ALT and log AST, especially increases from 0.0073 IU/L (95% confidence interval (CI) = 0.0042, 0.0104) to 0.0251 IU/L (95% CI = 0.0132, 0.0371) per interquartile range (IQR) increase of each pollutant (all pollutants: p < 0.001). Association of the liver enzymes with PM10 (ß (95% CI) = 0.0285 IU/L (0.0201, 0.0368) for log ALT; ß (95% CI) = 0.0139 IU/L (0.0079, 0.0198) for log AST) and CO (ß (95% CI) = 0.0247 IU/L (0.0182, 0.0311) for log ALT; ß (95% CI) = 0.0164 IU/L (0.0118, 0.0210) for log AST) were only significant among drinkers. Our findings suggest that chronic exposure to PM10 and CO is a risk factor for liver enzymes increases among the general adult population who admitted to drinking alcohol.

Interactions of CDH13 gene polymorphisms and ambient PM10 air pollution exposure with blood pressure and hypertension in Korean men.

Associations between air pollution and blood pressure (BP) traits can be modified by several candidate genes, which might explain differences in individual genetic susceptibility. Based on recent evidence hypothesized to link air pollution and BP traits, we examined whether the polymorphisms of CDH13-a candidate gene-would modify the relationship between them in adult Korean men. A total of 1816 subjects were included. We divided them into two groups of high or low to moderate exposure using the annual average concentration of particulate matter with an aerodynamic diameter ≤10 µm (PM10). We conducted an interaction analysis of PM10 exposure using 200 single-nucleotide polymorphisms (SNPs), located within CDH13, in subjects with regard to BP traits and hypertension. The rs7500599 intronic SNP of CDH13 had the strongest signals for all BP traits including systolic blood pressure (SBP), diastolic blood pressure, and hypertension, by interacting with PM10 exposure. An additional stratified analysis showed that the effects of PM10 exposure on elevated BP and hypertension increased gradually in proportion to the number of minor alleles in this SNP. In addition, PM10 exposure in the TT or GT genotype groups did not show significant associations with BP traits, whereas in a homozygous risk allele (GG) group, PM10 exposure was significantly associated with BP traits and hypertension. For SBP, these patterns were reproducible at two independent sampling sites. This CDH13 polymorphism amplifies the negative associations of PM10 exposure and elevated BP or hypertension in Korean men.

CYP1A1 gene polymorphisms modify the association between PM10 exposure and lung function.

Genetic epidemiological studies have provided evidence that several genes modify the link between air pollution and lung function. We assessed whether the adverse impacts of particulate matter with an aerodynamic diameter ≤10 µm (PM10) on lung function are modified by CYP1A1 gene polymorphisms in Korean adults. We used health check-up data from 1817 men, and the annual mean concentrations of ambient PM10 estimated from the ambient data. Three single nucleotide polymorphisms (SNPs) of CYP1A1 were selected for our study. We identified significant CYP1A1 SNPs-by-PM10 interactions for forced expiratory volume 1 s (FEV1) and forced vital capacity (FVC) (all pint < 0.05). Minor allele carriers of the SNPs were more susceptible to PM10-induced FEV1 and FVC reduction. The subgroup analysis of SNP genotypes showed that no significant association between PM10 and FEV1 or FVC was observed in homozygous reference genotype groups of all SNPs (all passoc > 0.05), whereas in heterozygous or homozygous alternate genotype groups, PM10 was significantly associated with decreased FEV1 (all passoc for FEV1 < 0.05). The association between persistent exposure to PM10 and lung function decline in Korean men may be determined in part by several functional variants of the CYP1A1 gene.

Association between exposure to ambient air pollution and renal function in Korean adults.

BACKGROUND: Ambient air pollution has a negative effect on many diseases, such as cardiovascular and respiratory diseases. Recent studies have reported a relationship between air pollution and renal function, but the results were limited to exposure to particulate matter (PM). This study was to identify associations between various air pollutants and renal function among Korean adults. METHODS: Nationwide survey data for a total of 24,407 adults were analyzed. We calculated the estimated glomerular filtration rate (eGFR) for each individual to assess their renal function and used this to categorize those with chronic kidney disease (CKD). To evaluate exposure to ambient air pollution, we used the annual mean concentrations of four ambient air pollutants: PM with an aerodynamic diameter ≤ 10 µm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO). RESULTS: We identified significant inverse relationships between the air pollutants PM10 and NO2 and eGFR in all statistical adjustment models (all p < 0.05). In the full covariate model, interquartile range increases in the annual mean concentrations of PM10 and NO2 were associated with decreases in eGFR levels of 0.46 (95% CI = - 0.87, - 0.04) and 0.85 (95% CI = - 1.40, - 0.30), respectively. Three of the ambient air pollutants were significantly related to an increased risk of CKD in the unadjusted model (p < 0.0001), but all significant associations disappeared after adjusting for covariates (all p > 0.05). CONCLUSIONS: Exposures to PM10 and NO2 were significantly associated with decreases in eGFR levels, but not CKD, in Korean adults.

Estimation of CO2 emissions from waste incinerators: Comparison of three methods.

Climate-relevant CO2 emissions from waste incineration were compared using three methods: making use of CO2 concentration data, converting O2 concentration and waste characteristic data, and using a mass balance method following Intergovernmental Panel on Climate Change (IPCC) guidelines. For the first two methods, CO2 and O2 concentrations were measured continuously from 24 to 86 days. The O2 conversion method in comparison to the direct CO2 measurement method had a 4.8% mean difference in daily CO2 emissions for four incinerators where analyzed waste composition data were available. However, the IPCC method had a higher difference of 13% relative to the direct CO2 measurement method. For three incinerators using designed values for waste composition, the O2 conversion and IPCC methods in comparison to the direct CO2 measurement method had mean differences of 7.5% and 89%, respectively. Therefore, the use of O2 concentration data measured for monitoring air pollutant emissions is an effective method for estimating CO2 emissions resulting from waste incineration.

CDH13 gene-by-PM10 interaction effect on lung function decline in Korean men.

Lung function can be influenced by genetic factors, which may explain individual differences in susceptibility to the effects of air pollution. This study investigated whether the effect of particulate matter with an aerodynamic diameter ≤10 µm (PM10) on lung function is modified by Cadherin 13 (CDH13) genetic variants in Korean men. This study included a total of 1827 men who were recruited from two health check-up centers, and the annual average PM10 concentrations were used. A total of 200 single-nucleotide polymorphisms (SNPs) of the CDH13 gene were selected for this study. We found that a SNP in CHD13 intron, rs1862830, had the strongest associations with both forced expiratory volume in 1 s (FEV1) (pint = 1.90 × 10-4) and forced vital capacity (FVC) (pint = 1.88 × 10-3) by interacting with PM10 in a recessive model. A stratified association analysis according to this SNP showed that PM10 in the AG or GG genotype group was not significantly associated with either FEV1 or FVC, whereas in homozygous risk-allele carriers (AA), FEV1 and FVC decreased significantly (by 3.8% and 3.1%, respectively) per 10 µg/m3 of increase in PM10 concentration. This pattern was also reproducible in the independent subgroups that were classified according to recruitment site. The present study replicated the CDH13 gene-by-PM10 interaction effect on lung function at the gene level, revealing that a genetic variant of CDH13 modified the relationship between PM10 and lung function decline in Korean men.

Geosporobacter ferrireducens sp. nov., an anaerobic iron-reducing bacterium isolated from an oil-contaminated site.

In this study, an alkaliphilic and heterotrophic iron-reducing bacterial strain, IRF9(T), was isolated from an oil-contaminated soil in the Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain IRF9(T) belongs to the genus Geosporobacter in the family Clostridiaceae and is most closely related to Geosporobacter subterraneus VNs68(T) (96.9 % sequence similarity). Cells of strain IRF9(T) were observed to be straight or curved rod-shaped, motile and Gram-negative. Optimal growth of strain IRF9(T) was observed at pH 9.0-9.5 and 40 °C. The strain was found to grow within pH and temperature ranges of 6.5-10.0 and 25-45 °C, respectively. NaCl was not required for growth. Fe(III), but not sulfate, thiosulfate or elemental sulfur can be used by strain IRF9(T) as an electron acceptor. A limited number of carbohydrates and amino acids, including D-glucose, D-fructose, D-mannitol, D-ribose and L-arginine, support growth of strain IRF9(T). The main fatty acids (>10 %) of strain IRF9(T) were identified as C14:0 (18.4 %), C16:1 cis9 (13.6 %), C16:0 (12.4 %) and C16:0 dimethyl acetal (17.7 %). Major respiratory quinone was identified as menaquinone MK-5 (V-H2). The main polar lipids were found to be phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C content of strain IRF9(T) was determined to be 37.2 mol%, which is lower than that of G. subterraneus VNs68(T) (42.2 mol%). Based on phenotypic, chemotaxonomic, and phylogenetic studies, we conclude that strain IRF9(T) (=JCM 19987(T) = KCTC 15395(T)) represents a new species of the genus Geosporobacter, for which we propose the name Geosporobacter ferrireducens sp. nov.

Marinoscillum luteum sp. nov., isolated from marine sediment.

A novel strain, designated SJP7(T), was isolated from sediment of the Tofua Arc of the Tonga Trench. The 16S rRNA gene sequence of the isolate showed the highest similarity to that of Marinoscillum pacificum KCCM 42325(T) (95.9%). Phylogenetic analysis revealed that the isolate formed a distinct phyletic line with Marinoscillum pacificum KCCM 42325(T) and Marinoscillum furvescens LMG 13023(T) within the family Cytophagaceae. Cells of strain SJP7(T) were Gram-stain-negative and appeared as long rods that were motile by gliding. Growth was observed at 15-40 °C (optimum, 30 °C), at pH 5.5-9.0 (optimum, pH 7.5-8.0) and in the presence of 0.5-7.0% (w/v) NaCl (optimum, 2.5-3%). The major respiratory quinone was MK-7. The dominant fatty acids were summed feature 3 (comprising C(16:1)ω7c and/or C(16:1)ω6c), iso-C(15:0) and C(16:1)ω5c. The DNA G+C content was 43.5 mol%. These properties support the affiliation of strain SJP7(T) with the genus Marinoscillum. Further phenotypic differentiation of strain SJP7(T) from other species of the genus Marinoscillum was indicated by the results of physiological and biochemical tests. On the basis of evidence from our polyphasic taxonomic study, strain SJP7(T) represents a novel species of the genus Marinoscillum, for which the name Marinoscillum luteum sp. nov. is proposed. The type strain of Marinoscillum luteum is SJP7(T) ( =KCTC 23939(T) =NCAIM B02491(T)).

Nickel-catalyzed cross-coupling of neopentyl arenesulfonates with methyl and primary alkylmagnesium bromides.

[reaction: see text] Neopentyl arenesulfonates were reacted with methyl and primary alkylmagnesium bromides in the presence of dppeNiCl(2), via the nucleophilic aromatic substitution of neopentyloxysulfonyl groups by the primary alkyl nucleophiles, to produce the corresponding alkylarenes in good yields. This result shows that the alkyloxysulfonyl group might be a suitable alternative to halides and triflate in some circumstances.