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Despite the economic viability and promising potential of Na-ion batteries, their commercialization remains unrealized because of the limited intercalation of Na+ ions into graphite anodes due to the large ionic radius of Na and instability of Na+ ions on the interstitial sites, which result in a poor cell performance. Herein, we report a synthetic strategy for increasing the graphite interlayer distance along c-axis to facilitate the intercalation of Na+ ions by embedding Group VI W metallic pillars between the graphene layers. The strong electrostatic attraction between the positively charged W6+ ions and the negatively charged graphene oxide (GO) layers enables the assembly of the expanded graphite layers by W pillars (W-rGO) via a subsequent chemical reduction. The interlayer spacing of the reconstructed W-rGO increased to 11.1 A, which is three-fold larger than that of graphite (3.34 A). Consequently, the W-rGO anodes delivered an exceptionally high capacity of 678 mAh g−1 for a Na-ion battery compared with that of a pristine rGO anode (240 mAh g−1). Further, we elucidate the structural characteristics and electrochemical reaction mechanisms of the W-rGO anodes. This work presents a simple and effective strategy for developing high-performance carbon-based anode materials for the realization of Na-ion battery technology.

It has been reported worldwide that the Zika virus (ZIKV) could be transmitted through placentas and sexual contact. ZIKV can also cause Guillain-Barre syndrome, microcephaly and neurological abnormalities. However, there are no approved vaccines available. We constructed six DNA vaccine candidates and tested the immunogenicity. Tandem repeated envelope domain Ⅲ (ED Ⅲ × 3) induced highly total IgG and neutralization antibody, as well as CD8+ T cell responses. Also, stem region-removed envelope (E ΔSTEM) elicited a robust production of IFN-γ in mice. To examine in vivo protection, we used mice treated with an IFNAR1 blocking antibody before and after the challenge. Vaccination with the two candidates led to a decline in the level of viral RNAs in organs. Moreover, the sera from the vaccinated mice did not enhance the infection of Dengue virus in K562 cells. These findings suggest the potential for the development of a novel ZIKV DNA vaccine.

Workday respite activities are supposed to be beneficial for employees due to their intended relaxing and enjoyable nature, but employees may find it difficult to agilely switch their awareness and attention between work tasks and respite activities during work hours. Based on affective events and mindfulness-to-meaning theories, we propose workday respite activities as affective events and identify mindfulness—the exercise of non-judgmental awareness and attention to the present moment—as a moderator that facilitates psychological detachment from work during workday respite activities, which in turn enhances employee outcomes later in the day via affective states. Our results from three experience-sampling studies with full-time employees indicate that engaging in workday respite activities is indirectly and positively related with intrinsic motivation and work engagement via psychological detachment and positive affective state, while negatively related with work stress and emotional exhaustion via psychological detachment and negative affective state, especially when mindfulness is higher.

Japanese encephalitis is prevalent throughout the temperate and tropical regions of Asia and is caused by the Japanese encephalitis virus (JEV), a mosquito-borne viral pathogen. The plaque reduction neutralization test (PRNT) is currently recommended as the gold standard test for detecting human antibodies against JEV. The plaque assay is the most widely used method for detecting infectious virions and involves counting discrete plaques in cells. However, it is time-consuming, and results can be subjective (owing to analyst variability during manual plaque counting). The focus reduction neutralization test (FRNT), which is based on an immuno-colorimetric assay, can be used to automatically count foci formed by the JEV. Here, we compared the efficacy of PRNT and FRNT in measuring the neutralizing antibody titers using 102 serum samples from vaccinated and unvaccinated individuals. We observed positive correlations between these neutralization assays against the Nakayama and Beijing strains (R

Potential CO2 leakage is a major concern for carbon capture and storage (CCS). The effects of high soil CO2 concentration on microbes is a major element of impact assessments of CO2 leakage on terrestrial ecosystems. We conducted a field experiment to investigate the responses of microbial functional groups of ammonia-oxidizers, methanogens, and methanotrophs in high soil CO2 conditions. A single-point injection gassing plot (2.5 m × 2.5 m in size), which had 52.2% CO2 in the center (radius = 0.5 m) and 5.5% in the edge (radius = 1.7 m) at 10 cm depth, was employed. N2O and CH4 emissions increased after 1 day of injection because injected CO2 was instantly utilized by nitrifiers and methanogens. This suggests that the activities of the selected microbes could be stimulated by high soil CO2 concentrations. Prolonged CO2 injection has toxic effects on aerobic nitrifiers, but may favor anaerobic methanogens. However, the early stimulatory effects of high soil CO2 on N2O and CH4 production did not last to the end of injection. These results imply that increased N2O and CH4 emissions could be the minor side effects of high soil CO2. Microbes responded faster than plants to high soil CO2, with responses observed as late as 7 days after injection. The inhibition of plant absorption of soil water and nutrients by high soil CO2 concentrations may also influence microbial responses. Moreover, high soil water content could retard underground CO2 diffusion, which would magnify CO2 impacts on plants and microbes. Our results suggest that microbial response could be used as an early indicator of the impact assessments of CO2 leakage on soil ecosystems. An understanding of the interaction among soils, plants, and microbes would be helpful in assessing the biological risks of potential CO2 leakage.

Objective The aim of ths study was to investigate the combined association of overall diet quality and physical activity (PA) on the risk for metabolic syndrome (MetS) in Korean adults. Methods This cross-sectional study extracted the data on 1008 adults (384 men and 624 women) 20 to 64 y of age. Dietary quality was assessed using a recommended food score (RFS) modified for a Korean diet. The total PA was summed to obtain a metabolic equivalent task score. Participants were classified according to the recommended levels of PA and RFS. Multiple logistic regression analysis was applied to determine the associations of RFS and PA with the prevalence of MetS after adjustment for potential confounders. Results About 21% of men and 19% of women were reported to have MetS. Nearly 5% of both sexes reached the recommended level of diet quality and PA. In men, a significantly reduced odds ratio (OR) for MetS (OR, 0.16; 95% confidence interval [CI], 0.09–0.93) and hypertriglyceridemia (OR, 0.25; 95% CI, 0.04–0.99) was found in those with better diet quality, within the strata of high PA. In women, compared with inactive individuals with poor diet quality, the OR for abdominal obesity in those with a better diet quality and who were active was 0.21 (95% CI, 0.05–0.86). Conclusions Both diet quality and PA are associated with a lower risk for hypertriglyceridemia in men and abdominal obesity in women. These findings suggest that a sex-specific pattern of association between MetS and lifestyle factors (diet and PA) should be considered in clinical practice.

Glacier forelands provide an excellent opportunity to investigate vegetation succession and soil development along the chronosequence; however, there are few studies on soil biogeochemical changes from environmental factors, aside from time. This study aimed to investigate soil development and biogeochemical changes in the glacier foreland of Midtre Lov ́enbreen, Svalbard, by considering various factors, including time. Eighteen vegetation and soil variables were measured at 38 different sampling sites of varying soil age, depth, and glacio- fluvial activity. Soil organic matter (SOM) was quantitatively measured, and the compositional changes in SOM were determined following size-density fractionation. In the topsoil, the soil organic carbon (SOC) and total nitrogen (N) content was found to increase along the soil chronosequence and were highly correlated with vegetation-associated variables. These findings suggest that plant-derived material was the main driver of the light fraction of SOM accumulation in the topsoil. The heavy fractions of SOM were composed of microbially transformed organic compounds, eventually contributing to SOM stabilization within short 90-yr deglaciation under harsh climatic conditions. In addition to time, the soil vertical profiles showed that other environmental parameters, also affected the soil biogeochemical properties. The high total phosphorous (P) content and elec- trical conductivity in the topsoil were attributed to unweathered subglacial materials and a considerable amount of inorganic ions from subglacial meltwater. The high P and magnesium content in the subsoil were attributed to parent materials, while the high sodium and potassium content in the surface soil were a result of sea-salt deposition. Glacio-fluvial runoff hampered ecosystem development by inhibiting vegetation development and SOM accumulation. This study emphasizes the importance of considering various soil-forming factors, including parent/subglacial materials, aeolian deposition, and glacio-fluvial runoff, as well as soil age, to obtain a comprehensive understanding of the ecosystem development in glacier forelands.

The soils in urban greenery provide essential ecosystem services. However, only a few studies have assessed urban soil quality based on a comprehensive view of ecosystem services and soil multi-functionality. In this study, we suggest an urban soil quality index (uSQI) to evaluate soil status in various spatial types of urban greenery. Our objectives are 1) to develop an uSQI incorporating a range of urban soil ecosystem services in metropolitan environments and 2) to test the efficacy of the developed uSQI by applying it to nine different sites. To fully consider ecosystem services provided by the urban soil, a DPSC (drivers and pressures, state, and changes) framework was constructed. Drivers and pressures are influencing factors that continuously alter the state of the urban greenery, eventually leading to changes in ecosystem services and soil functions. The six soil functions considered were physical stability and support, water storage and infiltration, habitat provision, organic matter stabilization, nutrient supply and retention, and pollutant immobilization and decomposition. These functions were measured using ten soil indicators which can be quantified: bulk density, saturated hydraulic conductivity, litter-layer depth, mineral-associated organic matter, clay+silt content, fluorescein diacetate hydrolytic activity, cation exchange capacity, inorganic nitrogen concentration, pH, and concentrations of potentially toxic elements. The uSQI was calculated as the arithmetic mean of the scores of the six soil functions, obtained through the fuzzy logic functions. The uSQI successfully identified the low soil quality sites among nine urban greeneries with different spatial types (point, line, and polygon). In addition, we could examine the degraded soil function of each site and suggest a management guideline using our uSQI. Our novel index can help urban stakeholders evaluate and monitor the soil quality of urban greenery.

Due to limitations of estrogen replacement therapy, life style interventions have received a growing attention. This study aimed to determine whether Pueraria-Rehmannia (PR) and/or aerobic exercise (Ex) could reduce cardiometabolic dysfunction in an ovariectomized/high-fat diet rat model. PR ameliorated circulating levels of total cholesterol, LDL/HDL ratio, and leptin. It reduced fat mass, fat size, leptin gene expression, and macrophage infiltration in adipocytes. PR maintained leptin receptor gene expression in muscle tissues. It stimulated insulin-mediated GLUT4 translocation in muscle and adipose tissues. PR plus Ex resulted in further improvement in glucose homeostasis by stimulating Akt-mediated insulin receptor expression in the liver. Moreover, PR and/or Ex reduced vascular wall thickness and intracellular cell adhesion molecule-1 production without causing uterotrophic effect. These results suggest that PR and Ex may exert synergistic effects in modifying metabolic dysfunctions and insulin resistance, thus suppressing cardiovascular risks in postmenopausal women through restoring insulin sensitivity and attenuating inflammation.

Soil structure degradation is a major obstacle to vegetation growth in urban roadside greenery, particularly under drought conditions. Biochar application can improve soil structure and water retention; however, the mechanisms linking changes in soil aggregation with those in pore size distribution, and how they interactively influence plant growth remain unclear. In this study, we investigated the role of biochar in improving soil structure and water retention under drought stress in urban roadside greenery. In a field study, plots (2 m × 2 m) were established on roadside greenery in Suwon, Korea, in which 2.5% wt bochar was mixed with surface soil (

The aims of this study was to determine the actual levels of microbial contamination in cereal and Saeng-sik products and establish new microbial criteria for cereal and Saeng-sik products for the “Korea Food Code”. Monitoring microbial indicator organisms (i.e., total aerobic, coliform, and Escherichia coli counts) and food-borne pathogens (i.e., Bacillus cereus, Staphylococcus aureus, and Clostridium perfringens) revealed that the total aerobic counts of cereal and Saeng-sik products were not detected (ND)–2.48 and 4.00–7.88 log10 CFU/g, respectively, whereas coliform bacteria were only detected in Saeng-sik (ND–5.24 log10 CFU/g). Cereals and Saeng-sik products were also contaminated with B. cereus (ND–2.95 log10 CFU/g and −0.40–3.30 log10 CFU/g, respectively). However, S. aureus, C. perfringens and E. coli were not detected in any of the cereal or Saeng-sik products. Based on this study, a revision was proposed for microbial criteria in cereal and Saeng-sik products.

The construction of a carbon-encapsulated multi-core nanostructure based on transition metal nitride is a preferred approach to efficiently mitigate volume expansion with improved sustainability and to enhance conductivity with more active sites for Li-ion cell reaction. Herein, we report the in-situ formation of carbon-coated nickel–cobalt nitride multi-core nanoparticles encapsulated by hollow N-doped carbon shell via monodispersed Ni3[Co(CN)6]2 Prussian blue analogue/polydopamine precursors using by simultaneous nitridation and calcination process. The (Ni/Co)3N multi-core nanoparticles (Ni:Co = 3:2) were highly dispersed in conductive and hollow N-doped carbon shell, thereby (i) mitigating mechanical stress by volume change during the conversion reaction of nitrides, (ii) stabilizing the electrochemical reaction surface with a thin solid electrolyte interphase, and (iii) maintaining the original structure and hierarchical morphologies even after long cycles. The (Ni/Co)3N multi-core@hollow N-doped carbon shell demonstrated better electrochemical performance than the (Ni/Co)3N@carbon shell without the outer hollow N-doped carbon shell for the Li-ion battery anode, which has an excellent reversible capacity of ~440 mAh g−1 and a stable cycle life of 130 cycles at 200 mA g−1. The rational synthetic strategy of the unique hybrid nanoarchitecture via in-situ formation of polymer-coated metal–organic frameworks is key in improving the Li-ion storage capacity and cycle stability.

Atmospheric carbon dioxide (CO2) concentrations is continuing to increase due to anthropogenic activity, and geological CO2 storage via carbon capture and storage (CCS) technology can be an effective way to mitigate global warming due to CO2 emission. However, the possibility of CO2 leakage from reservoirs and pipelines exists, and such leakage could negatively affect organisms in the soil environment. Therefore, to determine the impacts of geological CO2 leakage on plant and soil processes, we conducted a greenhouse study in which plants and soils were exposed to high levels of soil CO2. Cabbage, which has been reported to be vulnerable to high soil CO2, was grown under BI (no injection), NI (99.99% N2 injection), and CI (99.99% CO2 injection). Mean soil CO2 concentration for CI was 66.8–76.9% and the mean O2 concentrations in NI and CI were 6.6–12.7%, which could be observed in the CO2 leaked soil from the pipelines connected to the CCS sites. The soil N2O emission was increased by 286% in the CI, where NO3−-N concentration was 160% higher compared to that in the control. This indicates that higher N2O emission from CO2 leakage could be due to enhanced nitrification process. Higher NO3−-N content in soil was related to inhibited plant metabolism. In the CI treatment, chlorophyll content decreased and chlorosis appeared after 8th day of injection. Due to the inhibited root growth, leaf water and nitrogen contents were consistently lowered by 15% under CI treatment. Our results imply that N2O emission could be increased by the secondary effects of CO2 leakage on plant metabolism. Hence, monitoring the environmental changes in rhizosphere would be very useful for impact assessment of CCS technology.

Ethnopharmacological relevance Hovenia dulcis, known as the oriental raisin tree, is mainly found in East Asia. It has long been used as traditional folk remedies for alcohol intoxication. Aim of the study To examine the anti-hangover effect of Hovenia dulcis Thunb. fruit extract (HDE) in a randomized controlled crossover trial. Materials and methods Twenty-six eligible male adults with heterozygous ALDH2 (23.7±0.3 years old) consumed 360 mL of Korean Soju (50 g alcohol) together with HDE (2460 mg) or matched placebo with subsequent crossover. The blood samples were taken at baseline and 1, 4, and 12 h post-treatment. Results Blood alcohol, acetaldehyde, and total hangover scores were highest at 1 h post-treatment with no difference between groups, but declines in hangover symptom scores were significant in the HDE group compared to the placebo group. Significant differences between groups were also observed on interleukin (IL)-6, IL-10, IL-10/IL-6 ratio, and aspartate aminotransferase levels, but not on endotoxins. Pearson correlation analysis revealed a positive correlation between total hangover symptom scores and IL-6 and IL-10 level. Further analyses by CYP2E1 polymorphism at rs10776687, rs2031920, rs3813867, and rs4838767 alleles showed a reversed association, suggesting that CYP2E1 polymorphism might be an effect modifier. Conclusions The results suggest that a favorable effect of HDE on alcohol hangovers might be associated with enhancing homeostatic regulation of inflammatory response. The magnitude of impact might be different in the presence of CYP2E1 polymorphism.

In Korea, measles occurs mainly in infants12months of age, who are unvaccinated. In addition, vaccine populations, including adolescents and young adults, can become infected though importation. Thus, the question arises whether the current level of herd immunity in Korea is now insufficient for protecting against measles infection.Age-specific measles seroprevalence was evaluated by performing enzyme immunoassays and plaque reduction-neutralization tests on 3050 subjects aged 0-50years (birth cohort 1964-2014) and 480 subjects aged 2-30years (birth cohort 1984-2012).The overall seropositivity and measles antibody concentrations were 71.5% and 1366mIU/mL, respectively. Progressive decline in antibody levels and seropositivity were observed over time after vaccination in infants, adolescents, and young adults. The accumulation of potentially susceptible individuals in the population was confirmed by comparing data from 2010 and 2014 seroprevalence surveys. The statistical correlation between measles incidence and measles seronegativity was determined.Waning levels of measles antibodies with increasing time post-vaccination suggests that measles susceptibility is potentially increasing in Korea. This trend may be related to limitations of vaccine-induced immunity in the absence of natural boosting by the wild virus, compared to naturally acquired immunity triggered by measles infection. This study provides an important view into the current measles herd immunity in Korea.

Endothelial cell injury and dysfunction caused by reactive oxygen species (ROS) are implicated in the pathogenesis of vascular diseases. ROS are generated and hypoxanthine is degraded by xanthine oxidase. Smoking and alcohol consumption are associated with an increased level of hypoxanthine. We aimed to study the direct role of hypoxanthine in endothelial dysfunction in human umbilical vascular endothelial cells (HUVECs). Hypoxanthine induced cell death and production of ROS. Furthermore, hypoxanthine induced apoptosis through regulation of protein expression related to apoptosis. When cells were pretreated with N-acetylcysteine or a pancaspase inhibitor (Z-VAD-fmk) and stimulated with hypoxanthine, Z-VAD-fmk and N-acetylcysteine prevented hypoxanthine-induced apoptosis by inhibiting the ROS production and caspase pathway. Thus, an increased extracellular concentration of hypoxanthine induces endothelial dysfunction through ROS production and regulates expression of apoptosis-related proteins in HUVECs. These effects are expected to be associated with some vascular diseases.

Aging and age-related diseases in humans are mainly caused by oxidative stress through over-production of reactive oxygen species (ROS). In our previous study, multi-micronutrient supplement containing antioxidants and phytochemicals (MP) resulted in higher antioxidative activity by increasing plasma folate with resistance to DNA damage and LDL oxidation to subjects. In this study, plasma samples were analysed for metabolomics study using 1 H NMR. The metabolic profiles before MP supplementation and after 8-week MP supplementation were clearly separated based on multivariant analyses of principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA). Twenty-seven metabolites from variable importance plots were screened before MP supplementation and after 8-week MP supplementation. The 27 metabolites had significantly increased levels of betaine but significantly decreased levels of choline, serine, and threonine after MP supplementation. These results suggested that MP supplementation could activate folate cycle to increase resistance to DNA damages.

Biochar has been proposed as a promising amendment that may improve soil structure. However, our understanding how it mitigates extreme soil water stress in roadside soils is limited. In this study, we investigated the effects of biochar on soil properties and plant growth under extreme water stress conditions. A greenhouse experiment was conducted on two-year-old Gingko biloba saplings planted in pots with sandy soil only (CON) and with sandy soil mixed with biochar (BC). To simulate excessive water stress conditions, we increased the soil water-filled pore space up to the saturation level throughout the experimental period. We also simulated the switching water conditions by maintaining the saturation condition for 30 days, followed by no addition of water. The BC treatment significantly influenced the aggregate distribution and enhanced the proportion of macroaggregates (250 μm). The biochar itself also functioned as a macroaggregate and contributed to increased aeration under the excessive water condition. Under the switching water condition, the micropores within the biochar might have helped maintain the available water for plant roots and soil microbes. Plant growth was significantly higher in the BC than CON soils for both the excessive and switching water sets. In the BC soils, plant growth was higher in the excessive than in the switching water sets, indicating that the soil water status in our BC treatment for the excessive water set was not stressful enough to inhibit plant growth. The % optimal water condition, which is defined as the proportion of days when the soil water status is within the least limiting water range, had a very high explanatory power to explain the plant growth (r = 0.7172, p 0.0001). Our results indicate that biochar can alleviate water stresses in urban roadside soils by retaining plant available water under the wet and dry conditions.

Recent studies on animals have suggested that vinegar consumption may confer an antiobesity effect through the activation of the AMP-activated protein kinase (AMPK) signaling pathway. However, mechanisms of action in humans remain largely unknown. A randomized, double-blind, placebo-controlled trial was performed to examine whether a pomegranate vinegar (PV) beverage alleviates adiposity in overweight subjects, with emphasis on AMPK activation. Seventy-eight overweight women (BMI ≥ 25) were randomly assigned to receive either PV (1.5 g acetic acid and 700 μg ellagic acid/200 mL/day) or a placebo for 8 weeks. The PV reduced visceral adipose tissue, as measured by computed tomography (P = 0.037), and enhanced AMPK phosphorylation (P = 0.013) compared with the placebo group. The PV tended to suppress downstream gene expression, such as that of sterol regulatory element binding protein-1c and acetyl coenzyme carboxylase, in adipose tissue. Together, these data suggest that PV is an excellent AMPK activator and may exert beneficial effects on adiposity.

Recombinant measles virus nucleoproteins (rMeV N) and fusion (F) proteins were characterized as major antigenic proteins expressed in insect cells mediated by recombinant baculoviruses (rBVs). Band intensities were analyzed by Western blotting to recognize IgG and IgM antibodies against the rMeV N and F proteins in human sera and cerebrospinal fluids (CSFs) from patients with measles infections. Positive results from the blots using the rMeV N were consistent with the results of enzyme-linked immunosorbent assays (ELISAs) in which whole viral proteins were used as antigens. Human sera and CSFs reacted more strongly with the rMeV N than with the rMeV F proteins prepared in an identical expression system. For efficient and reliable purification, ion-exchange chromatography using Source Q anion resin was applied, and high-purity rMeV N protein was harvested. To characterize the similarity with the native viral protein to purified N protein, structural mimicry of purified recombinant proteins with intact rMeV N was shown through transmission electron microscopy, and the truncation and the phosphorylation status of the expressed protein were analyzed. These results suggest that the rMeV N purified by ion-exchange chromatography has features similar to those of naïve N including a self-assembled structure, phosphorylation and antigenic function. Thus, these expression and purification methods can be applied to the large-scale production of the rMeV N, which is essential for the development of new diagnostic tools and vaccines for acute and chronic MeV infections.

OBJECTIVES: This study hypothesized that a higher diet quality score is associated with a lower observance of symptoms of depression and anxiety and a higher QoL. METHODS: This study Evaluated 1295 adults (521 men; 774 women) aged 19–64 years, who participated in the 2014–2015 National Fitness Award Project. Diet quality was measured by the recommended food score (RFS), and mental health and QoL were assessed by the Beck depression inventory (BDI), Beck anxiety inventory (BAI), and the World Health Organization QoL–Brief (WHOQoL–BREF). RESULTS: After adjusting for covariates, the individuals with depression had a significantly lower RFS value compared to those without depression, and the good QoL group had a higher RFS value than the poor QoL group. These trends occurred in both men and women. Subjects in the highest tertile of RFS showed a lower odds of depression (OR = 0.44, 95% CI = 0.29–0.68, P-trend = 0.0002) and poor QoL (OR = 0.35, 95% CI = 0.26–0.47, P-trend

We extend prior thinking about citizenship behavior by integrating employee motives, social support, and role cognitions as predictors of organizational citizenship behavior (OCB). Drawing on trait activation and situated self theories, we provide insights into why and when motives predict OCB using multi-source data from two field samples. In Study 1, we demonstrate that the quality of social support functions as a boundary condition that qualifies relations of motives with OCB. In Study 2, we introduce role cognitions as a proximal motivational factor that mediates the motives by social support interactions with OCB. Our results support the hypothesized moderated mediated model and enhance understanding of OCB by integrating the OCB motive and role cognition literatures, which to date have developed separately. As our results demonstrate, role cognitions, which are domain-specific felt obligations to perform OCB, mediate relations of more distal predispositions to perform OCB with helping and voice citizenship behaviors. © 2013 Elsevier Inc.

Background Following the implementation of national measles elimination plan in Korea, the elimination was declared in 2006. In order to sustain the elimination, high population immunity should be continuously monitored. To evaluate the current age-related susceptibility within the Korean population, we conducted the seroprevalence in children and adolescents who were affected by the national measles elimination plan. Methods We used residual serum specimens to measure measles specific IgG and geometric mean titer (GMT) in birth cohorts 2007–2008 and 1997–2003. Among birth cohorts, 2007–2008 cohorts were grouped to evaluate the timeliness of first dose of MMR, 1994–2003 cohorts were grouped to evaluate the effect of keep-up MMR2 campaign, and 1992–1993 cohorts were grouped to evaluate the effect of catch-up campaign in 2001. Results Overall, measles seropositivity rate was 86%. The highest seroprevalence of measles IgG was in birth cohorts 2007–2008. Measles seropositivity declined continuously in age groups. The birth cohorts 1994–1996 showed significantly lower levels of seropositivity and GMT than did the other birth cohorts. Conclusion Despite efforts to eliminate measles for the past 10 years in Korea, our study revealed specific birth cohorts remaining at risk for transmission. The adolescents born during 1994–1996 had the lowest measles seropositivity levels, and might represent a ‘pocket’ that has potential at increased risk for measles transmission. Further discussion for follow-up immunization should be placed for consideration in the near future.

The aims of this study were to determine (1) whether the urinary mid pregnancy and placental delivery oxidative stress levels are related to the intrauterine condition and (2) whether long-lasting adverse oxidative stress is related to the birth size. We investigated pregnant women when they were at 24-28 weeks of pregnancy from October 2001 to May 2003 and at their delivery. Samples were obtained at each investigation time. Other information of mothers and their birth records were tracked from medical charts at Ewha Womans University Hospital in Seoul, South Korea. We quantified mid pregnancy oxidative stress by measuring urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) in 272 subjects. Intrauterine oxidative stress at delivery was measured by placental levels of 8-OHdG and MDA in 54 and 38 subjects, respectively. To identify the correlated intrauterine oxidative stress conditions, we evaluated kappa statistics and Pearson's correlations between maternal and placental oxidative stress. The relationships between intrauterine oxidative stress and birth sizes were examined by a general linear model. The levels of oxidative stress were divided to two groups based on their 75th percentile values. There was no correlation between urinary mid pregnancy and placental delivery oxidative stress levels for both MDA (kappa index=0.32, r=0.21) and 8-OHdG (kappa index=-0.13, r=-0.11). Both the urinary mid pregnancy and delivery 8-OHdG levels were significantly related to birth size. The birth size was largest in the 8-OHdG group. In addition, birth size was worse in the group with both high urinary mid pregnancy and placental oxidative stress than in any other combinations of low and high groups of urinary mid pregnancy and placental delivery oxidative stress. This evidence for a weak correlation between urinary mid pregnancy and placental delivery oxidative stress levels and its interactive effects on birth size suggest that the period from the middle to the end of pregnancy is critical window to intrauterine growth and also represents a modifiable period of the intrauterine condition. Therefore, applying interventions to pregnant women with high oxidative stress levels at midterm could contribute to increasing birth sizes.

Pregnancy is associated with increased susceptibility to oxidative stress. Deficiencies in antioxidants during pregnancy and placental oxidant-antioxidant imbalance may impair the development of the fetoplacental unit or the eventual offspring. In order to elucidate the association of prenatal status of vitamin C with the oxidative stress and apoptotic activity in normal full-term placentas, we evaluated the content of placental lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and the trophoblast apoptotic index in normal-term human pregnancies. Tissue samples of placentas obtained from 80 normal-term pregnancies were categorized into 40 cases with a lower level of prenatal vitamin C (8.997 microg/ml) and 40 cases with a higher level of prenatal vitamin C (or =11.734 microg/ml). We evaluated the placental LOX-1 content and the trophoblast apoptotic index with Western blot analysis and immunohistochemistry, and then determined their correlation with the prenatal status of vitamin C. We confirmed that the trophoblast expression for the endothelial scavenger receptor LOX-1 and the apoptotic activity were significantly lower in the group with a higher prenatal level of vitamin C, indicating that placental oxidative stress and the apoptotic index were associated with the maternal status of vitamin C. We therefore postulate that the maternal status of antioxidant vitamins during pregnancy can affect fetal development.

Vibrio vulnificus causes diseases through actions of various virulence factors, including the elastase encoded by the vvpE gene. Through transposon mutagenesis of V. vulnificus, vvpE expression was shown to be increased by luxO mutation. Since the vvpE gene is known to be positively regulated by SmcR via direct binding to the vvpE promoter, the role of LuxO in smcR expression was investigated. The luxAB-transcriptional fusions containing different lengths of the smcR promoter region indicated that the smcR transcription was negatively regulated by LuxO and that a specific upstream region of the smcR gene was required for this repression. Since LuxO is a known member of positive regulators, the negative regulation of smcR transcription by LuxO prompted us to identify the factor(s) linking LuxO and smcR transcription. LuxT was isolated in a ligand fishing experiment using the smcR upstream region as bait, and smcR expression was increased by luxT mutation. Recombinant LuxT bound to a specific upstream region of the smcR gene, -154 to -129 relative to the smcR transcription start site. The expression of luxT was positively regulated by LuxO, and the luxT promoter region contained a putative LuxO-binding site. Mutagenesis of the LuxO-binding site in the luxT promoter region resulted in a loss of transcriptional control by LuxO. Therefore, this study demonstrates a transcriptional regulatory cascade for elastase production, where LuxO activates luxT transcription and LuxT represses smcR transcription.

Because the phosphoenolpyruvate:sugar phosphotransferase system plays multiple regulatory roles in addition to the phosphorylation-coupled transport of many sugars in bacteria, synthesis of its protein components is regulated in a highly sophisticated way. Thus far, the cAMP receptor protein (CRP) complex and Mlc are known to be the major regulators of ptsHIcrr and ptsG expression in response to the availability of carbon sources. In this report, we performed ligand fishing experiments by using the promoters of ptsHIcrr and ptsG as bait to find out new factors involved in the transcriptional regulation of the phosphoenolpyruvate:sugar phosphotransferase system in Escherichia coli, and we found that the anaerobic regulator ArcA specifically binds to the promoters. Deletion of the arcA gene caused about a 2-fold increase in the ptsG expression, and overexpression of ArcA significantly decreased glucose consumption. In vitro transcription assays showed that phospho-ArcA (ArcA-P) represses ptsG P1 transcription. DNase I footprinting experiments revealed that ArcA-P binds to three sites upstream of the ptsG P1 promoter, two of which overlap the CRP-binding sites, and the ArcA-P binding decreases the CRP binding that is essential for the ptsG P1 transcription. These results suggest that the response regulator ArcA regulates expression of enzyme IICB(Glc) mediating the first step of glucose metabolism in response to the redox conditions of growth in E. coli.