Search

Since bundles provide price discounts to customers and have lock-in effects for businesses in the communications sector, the number of bundle subscribers is rapidly growing in many countries, including Korea. The consumer welfare and economic effects of bundles have been well documented. Existing literature, however, has paid little attention to identifying the facets of benefit and risk that influence subscription, the differences in switching costs between subscribers and non-subscribers, and the relationships among bundle satisfaction, customer retention, and switching costs. To address these gaps, we performed an empirical analysis using survey data from 550 individuals. Our findings show that concerns about lock-in and performance, as well as economic benefit influence subscription to the bundles, and all switching costs are higher for the subscribers than for stand-alone users. Non-monetary switching cost of bundles especially has a moderating effect on customer retention. The implications for regulatory policy and customer strategy are discussed.

Background Some evidence in humans suggests that persistent organic pollutants (POPs), including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), may alter the blood lipid composition. This study analyzed associations between serum POPs concentrations in young adulthood with blood lipid levels up to 23 years later. Methods Serum POPs were measured in year 2 of follow-up (n = 180 men and women, ages: 20-32y), and plasma lipids in follow-up years 2, 7, 10, 15, 20 and 25. 32 POPs were detectable in ≥75% of participants (23 PCBs, 8 OCPs and PBB-153). We created summary scores for PCBs and OCPs for both wet-weight, and lipid standardized (LP) concentrations. We used repeated measures regression adjusting for demographic factors, BMI, smoking, diabetes status, among others. Results We observed positive associations of the 23 LP-PCB score with total cholesterol (βper SD increase [95%CI]: 5.0 mg/dL [0.7, 9.2]), triglycerides (7.8 mg/dL [-0.9, 16.5]), LDL (4.2 mg/dL [0.2, 8.2]), oxidized LDL 3.4 U/L (-0.05, 6.8), and cholesterol/HDL ratio (0.2 [0.02, 0.3]). The associations for triglycerides (14.7 mg/dL [0.4, 20.1]), cholesterol/HDL (0.33 [0.09, 0.56]) and, to some extent, LDL (4.7 md/dL [-1.6, 10.9]) were only observed among participants in the upper 50th percentile of BMI. Non-dioxin-like PCBs had stronger associations that dioxin-like PCBs. OCPs and PBB-s had positive associations with most outcomes. Conclusions PCBs and PBB-153 measured in young adulthood were positively associated with prospective alterations in most blood lipid components, with evidence of effect modification by BMI. Further longitudinal studies with multiple measures of POPs overtime are needed.

Persistent organic pollutants (POPs), despite their considerably low levels in humans, are an increasing concern for the general populations given their various adverse health problems, including metabolic and carcinogenic effects. DNA methylation deregulation is thought to be a key mechanism in the development of human chronic diseases including cancer.In an attempt to identify biomarkers monitoring low-dose exposure and hazard, we explored whether organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) may influence the methylation of tumour suppressor gene E-cadherin (CDH1) using peripheral blood cells from 364 healthy Korean subjects.CDH1 methylation was observed in 78.3% of study subjects. Serum concentrations of OCPs or PCBs compounds were higher in CDH1 methylation-positive subjects than in methylation-negative ones. After adjusting for various covariates, the odds ratio of CDH1 methylation of the summary measure of PCBs were 1.0, 2.5 (95% confidence interval: 1.2-5.3), 3.6 (1.6-8.1), 3.6 (1.4-8.6), and 2.5 (1.1-5.7) across quintiles of PCBs (PIn this exploratory study with a small sample, CDH1 methylation might be served as the epigenetic biomarker associated with POPs exposure and adverse health effect.

Propofol is has been widely used for sedation in the field of esthetic surgery because of its favorable pharmacokinetic profile. Propofol sedation-induced side effects are rare. However, when present, they can be serious. The number of malpractice claims associated with propofol sedation has increased in recent years. This study aims to show which procedures lead to the most claims in the field of esthetic surgery through a review of Korean precedents. Thirteen precedent cases of propofol sedation in the field of esthetic surgery were collected between 2000 and 2016. We analyzed the type of procedure, administration route, anesthesia provider, complications, timing of damaging events, average indemnification, plaintiff’s (patients) winning rate, ratio and the reason of limitation of liability and the key factors affecting the judgement in these cases. Most plaintiffs were women, and in most cases (11/13, 73.3%), the times of the damaging events were in maintenance and the anesthesia provider was the surgeon. The most common complication related to propofol sedation was hypoxic brain damage. Among the 13 cases, 12 were won by the plaintiff. The mean claim settlement was 339,455,814 KRW (USD 301,792.15). The key factors affecting the judgement were administration method and staff, monitoring method, preparation of emergency kit, response to emergencies, transfer to a higher-level hospital, detailed medical recording about event and informed consent. The number of claims owing to propofol sedation after esthetic surgery is increasing. Close monitoring during the operation, immediate reaction to an event and thorough medical records were main key factors that influenced the judgement. Preoperative explanation about the possibility of complications was important. The findings will help surgeons achieve high patient satisfaction and reduce liability concerns. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Objectives: This study was conducted to evaluate the changes and regional differences of mortality and morbidity particularly respiratory system diseases in the area of expo sure to coal dust(Ansim area, Dong-gu, Daegu). Methods: The authors analyzed secondary data(cancer registration data, mortality data, and health insurance data) for respiratory system diseases. We calculated age standardized incidence ratio(SIR), mortality ratio(SMR), and health care utilization ratio(SHR) using those data. Results: There were no significant differences between Ansim area(or Dong-gu, Daegu) and the control area for cancer registration data and mortality data. In the results for the health insurance data, significant increased SHR in asthma was observed compared to the control area. Conclusions: Although confounders such as selection bias were not clearly ruled out, our findings reveal increased asthma SHR in the area of exposure to coal dust. Further prospective studies are required to clarify the increasing respiratory disease due to exposure to coal dust.

In this study, we have investigated solvent extraction of Ga and recovery of high pure Ga solution from MOCVD dust formanufacturing of LED chip. Effect of extractan, concentration of extractant were examined for choosing the more effectiveextractant and high pure Ga solution was fabricated by multi-stage extraction/stripping process. For extraction/separation of Gabased on the analysis of raw-material in previous study, 3 different extractants PC 99A, DP-8R, Cyanex 272 has been inves-tigated and the extraction efficiency of 1.5 M Cyanex 272 was 43.8%. It was conformed that extraction efficiency of Ga was83% in multi-stage extraction and 5N high purity Ga stripping solution without impurities also obtained.Key words : MOCVD dust, Ga purification, solvent extraction, Cyanex 272 · Received : June 25, 2015 · Revised : July 15, 2015 · Accepted : July 24, 2015Corresponding Author : Chan Gi Lee (E-mail : cglee@iae.re.kr)Advanced Materials & Processing Center, Institute for Advanced Engineering, 175-28, 51 Goan-ro, Baegam-myeon, Cheoin-gu,Youngin-si, Gyeonggi-do, 449-863, KoreaⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

Citizens’ trust in a government is critical when the government utilizes Twitter to communicate with the public. This research collected 398 questionnaire samples from Korean citizens who communicate with a central government department via Twitter and employed a structured equation analysis. The study discovered that tweets coming from a leading (or an executive) government officer (e.g., a minister) played mediation role in increasing citizens’ perception of credibility in governmental Twitter feed. Furthermore, the citizens’ trust in governmental media functioned as a moderator for expanding their trust in government from an agency level to the overall government.

We investigated if certain persistent organic pollutants (POPs), namely polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides, predicted total, cardiovascular disease (CVD), and cancer mortality among the elderly, with the hypothesis that associations differ by the amount of fat mass.We studied serum concentrations of 11 PCBs in 633 elders (age≥70 years) and of 5 OC pesticides in 675 elders within the National Health and Nutrition Examination Survey (NHANES) 1999-2004. Mean follow-up was 4.1-years.Neither PCBs nor OC pesticides were associated with total mortality when fat mass was not considered in analyses. However, associations of PCBs and OC pesticides with total mortality depended on fat mass (Pinteraction0.01 and 0.06, respectively). PCBs associated inversely with total mortality for high fat mass, but not for lower fat mass. On the contrary, OC pesticides associated positively with total mortality for low fat mass and this association weakened at higher fat mass. The interaction was also observed with CVD mortality. In elders with low fat mass, higher PCBs associated with 2-3 fold higher risk of CVD mortality, while this association was absent in elders with more fat mass (Pinteraction=0.03). The positive association between OC pesticides and CVD mortality was also observed only among elderly with low fat mass (Pinteraction=0.03).The possibility of interaction between POPs and the amount of fat mass on risk of mortality from chronic diseases is clinically important in modern societies with an obesity epidemic and requires confirmation in other studies with larger sample size.

ObjectivesSubstantial evidence associates persistent organic pollutants (POP) with metabolic disturbances related to diabetes, but longitudinal studies with repeated measures are scarce. We aimed to characterize the association between background exposures to POPs with repeated measures of glucose homeostasis over 23-years.MethodsWithin the Coronary Artery Risk Development in Young Adults study (year 0 ages: 18-30 years), we measured POPs in serum obtained in 1987-88 (follow-up year 2) in 90 non-diabetic controls and 90 cases diabetes-free at year 2 who became diabetic by year 20. We analyzed 32 POPs detectable in ≥75% of participants and created summary scores for 32 POPs, 23 polychlorinated biphenyls (PCB), and 8 organochlorine pesticides (OCP). Dependent variables were measures of glucose homeostasis at years 0-25 (up to 8 examinations). We explored associations using repeated measures regression adjusted for race, sex, concurrent body mass index (BMI), examination center and period, separately for cases and controls.ResultsThe associations between the three summary scores and measures of glucose homeostasis were present for observations at ages 40-55 years, and particularly between 48-55 years: the 23 PCB summary was associated with HbA1c (never-diabetics: slope [value per unit of summary score], β=0.008, p=0.02; diabetics: β=0.03, p=0.07), fasting glucose (never-diabetics: β=0.24, p=0.003; diabetics: β=1.10, p=0.03), and insulin sensitivity% (never-diabetics: β=-2.82, p

In clinically aggressive diseases, patients experience pathophysiological changes that often alter concentrations of lipids and environmental lipophilic factors; such changes are related to disease signs and symptoms. The aim of the study was to compare the effects of correcting for total serum lipids (TSL) and other clinical factors on the odds of mutations in the K-ras oncogene by organochlorine compounds (OCs), in logistic models, in 103 patients with exocrine pancreatic cancer (EPC) using a causal directed acyclic graph (DAG) framework. Results and likelihood of bias were discussed in the light of possible causal scenarios. The odds of K-ras mutated EPC was associated with some TSL-corrected OCs, including p,p'-DDT (p-value: 0.008) and polychlorinated biphenyl 138 (p-trend: 0.024). When OCs were not corrected by TSL, the OR of a K-ras mutation was significant for p,p'-DDT (p-trend: 0.035). Additionally adjusting for cholestatic syndrome increased the ORs of TSL-corrected OCs. When models were adjusted by the interval from first symptom to blood extraction (ISE), the ORs increased for both TSL-corrected and uncorrected OCs. Models with TSL-corrected OCs and adjusted for cholestatic syndrome or ISE yielded the highest ORs. We show that DAGs clarify the covariates necessary to minimize bias, and demonstrate scenarios under which adjustment for TSL-corrected OCs and failure to adjust for symptoms or ISE may induce bias. Models with TSL-uncorrected OCs may be biased too, and adjusting by symptoms or ISE may not control such biases. Our findings may have implications as well for studying environmental causes of other clinically aggressive diseases.

A scalable solution-based method for fabricating carbon-coated Ni-Si nanocomposites for use as anode materials in Li-ion batteries is reported. This facile process involves a one-pot synthesis using an electrical pulse technique in oleic acid containing Si nanoparticles at room temperature and a subsequent carbonization route. In these nanocomposites, the Si nanoparticles are individually and separately coated with a carbon shell with a nanoscale thickness. Furthermore, the nanocomposites have a large specific surface area with a spherical complex-structure in which Ni nanoparticles and carbon layers play various pivotal roles, as a mechanically supporting barrier against the aggregation of Si nanoparticles and as an electronic pathway between the active Si nanoparticles. Because of these favorable features, the obtained nanocomposites exhibit not only better cycling performances, but also rate capability, in comparison with bare Si anode materials.

In this study, we investigate firms that the Korea Exchange claims have made unfaithful disclosures. We find that such firms experience significantly negative stock price returns, suggesting that their managements exploit the information asymmetry involved in unfaithful disclosures to expropriate shareholder wealth. Our evidence shows that firms with higher management ownership experience a smaller decline in stock returns following notices of unfaithfulness, implying that corporate governance could improve the overall information environment and thus eventually help mitigate the information asymmetry associated with investors’ lack of timely and correct information. An evaluation of idiosyncratic volatility, a direct measurement of information asymmetry, confirms our results.

Background Suicide is a significant public health problem worldwide. Suicide rates among elderly persons (≥ 65 years of age) are three times higher than those of younger people in Korea. The emergency department is an important entry of drug-related suicide attempt patients. In this study, we compared the frequency of drug types by age subgroup. Furthermore, we provide suggestions for preventing suicide attempts in the elderly. Methods We investigated 433 patients who were admitted to the emergency department for drug-related suicide attempts between 1 May 2015 and 30 April 2017. Results The proportion of patients who overdosed on antidepressants was 32.5% in the non-elderly age group and 8.0% in the elderly group (≥ 65 years of age) (P < 0.001). Among the elderly, the most commonly ingested agent was hypnotics (59.1%) (P < 0.001). Compared with the non-elderly, the results showed that the elderly used fewer antidepressants (P < 0.001) and analgesics (P < 0.001). Meanwhile, the elderly used more hypnotics (P < 0.001). Over-the-counter drugs and other medications showed similar usage trends in both age groups (P = 0.664, P = 0.193). Conclusion The categories of drugs ingested for suicide attempts vary widely between different age groups. Younger people used antidepressants more frequently in suicide attempts, while the elderly used hypnotics more frequently. And the elderly required longer hospital stays. Suicide ideation and depressive mood in older patients who are prescribed hypnotics for various reasons should not be neglected. Further prevention efforts are needed to prevent suicide among the elderly., Graphical Abstract

Although the toxicity of synthetic chemicals at high doses is well known, chronic exposure to low-dose chemical mixtures has only recently been linked to many age-related diseases. However, it is nearly impossible to avoid the exposure to these low-dose chemical mixtures as humans are exposed to a myriad of synthetic chemicals as a part of their daily lives. Therefore, coping with possible harms due to low dose chemical mixtures is challenging. Interestingly, within the range of environmental exposure, disease risk does not increase linearly with increasing dose of chemicals, but often tends to plateau or even decrease with increasing dose. Hormesis, the over-compensation of various adaptive responses through cellular stresses, is one possible mechanism for this non-linearity. Although the hormetic effects of synthetic chemicals or radiation have long been debated in the field of toxicology, the hormesis concept has recently been generalized in the field of molecular biology; similar to responses to synthetic chemicals, mild to moderate intermittent stressors from any source can induce hormetic responses. Examples of stressors are exercise, calorie restriction, intermittent fasting, cognitive stimulation, and phytochemicals. Mitohormesis is hormesis induced by such stressors through mitochondrial retrograde signalling including the increased production of mild reactive oxygen species. Xenohormesis is phytochemical-induced hormesis, reflective of a mutualistic relationship between plant and animals. As humans had repeated exposure to all of these stressors during their evolution, the hormetic effects of these health behaviours may be considered to be evolutionarily adapted. Although hormesis induced by synthetic chemicals occurs in humans, such hormesis may not be recommended to the public due to unresolved issues on safety including the impossibility of control exposure. However, the use of personal health behaviors which enhance mitohormetic- or xenohormetic-stress can be readily incorporated into everyone's daily lives as a practical way to counteract harmful effects of unavoidable low-dose chemical mixtures.

This study demonstrated the 10-year trend of 13 perfluoroalkyl substances (PFASs) serum levels among 786 adults living in Seoul, Korea. PFAS levels gradually increased from 2006 to 2013, decreasing thereafter. We found that PFAS levels were higher in male than in female participants and were positively correlated with age. PFASs were not significantly correlated with body mass index, although we observed positive correlations with total cholesterol, low-density lipoprotein cholesterol, and triglycerides and negative correlations with high-density lipoprotein cholesterol. Uric acid and free thyroxine (fT4) also showed positive correlations with major congeners while correlations between thyroid stimulating hormone and PFASs were inconsistent. We demonstrated significant correlations between fT4 and perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and perfluorodecanoic acid (PFDA). There were significant differences in PFHxS and perfluorododecanoic acid (PFDoDA) levels between participants with and without diabetes. Furthermore, principal component analysis suggested possible differences in disease manifestation based on the congener distribution of PFASs. This study is the first study of temporal trends of 13 PFAS congeners in serum samples obtained from the Korean general population; it is currently longest and largest scale study of this type. Keywords: PFASs, Serum, Temporal trend, Health effects, Korea

Epidemiologic studies have indicated that albuminuria is associated with mortality from all causes and cardiovascular disease (CVD), with substantial heterogeneity. We evaluated if the associations of urine albumin creatinine ratio (ACR) with all-cause and CVD mortality differed depending on serum concentrations of persistent organic pollutants (POPs), strong lipophilic chemical mixtures with very long half-lives, which are recently linked to many degenerative diseases. Study subjects were participants of the National Health and Nutrition Examination Survey 1999-2004 who were 60 years or older at baseline (n=1215 and 1067 for organochlorine pesticides (OCPs) and other POPs, respectively). They were followed-up through 2011 (mean follow-up periods: 8.1 and 8.0 years for OCPs and other POPs, respectively). The associations between the ACR and all-cause mortality significantly differed by the serum levels of POPs, especially organochlorine pesticides (OCPs; Pinteraction

A narrative structure is one of the main components to constitute the genre of Massively Multiplayer Online Role-Playing Games (MMORPGs). Meanwhile Real Money Trade (RMT) enables a player to adjust an ex post level of challenge by skipping the narrative structure of a game. However, RMT may concurrently disturb a player who enjoys game following the narrative structure hierarchically. In pursuance of developing the knowledge about the relationship between RMT and the usage of MMORPG, we investigate the role of the strictness of predetermined narrative structure. We present the dual structure of societies to describe a player that arbitrarily decides to reside in a virtual society. Then we adopt the social nominalism to explain how individual motif of playing a game is expanded to the nature of game. Finally, we argue that a game with weakly predetermined narrative structure is more positively associated with RMT volume, since these games arouse a player’s sentiment of fun by relying more on their socially oriented motivation. With empirical evidence from the Korean MMORPGs market, we proved the hypothesis.

We report the one-pot synthesis of high-performance Sn@C nanocomposite anode materials obtained by uniform carbon coating onto Sn nanoparticles induced by electrical Sn-wire explosion in oleic acid liquid media at room temperature. This Sn@C nanocomposite exhibits highly reversible Li-storage performance with a specific capacity of ∼730 mA h g−1, even after 200 cycles.

Nanocomposites containing Fe3O4/Fe/multiwalled carbon nanotubes (MWCNT) were prepared via an electrical wire pulse process (a top-down approach) using Fe wire and dispersed, functionalized MWCNT in deionized water (DIW) at room temperature. The structural and electrochemical characteristics of the resulting nanocomposites were investigated in detail. When used as an anode for Li ion batteries, the Fe3O4/Fe/MWCNT nanocomposites exhibited greater cycle stability and rate performance than plain Fe3O4/Fe composites, with a capacity of 460 mA h g−1 at a rate of 168 mA g−1 after 50 cycles. The enhanced performance was attributed to superior electrical conductivity and buffering effect of the MWCNTs on volume changes of the anodes. This process is a promising facile method for lithium ion battery anode material synthesis.

Organophosphate poisoning is a serious clinical entity and considerable morbidity and mortality. Several factors have been identified to predict outcomes of organophosphate poisoning. Organophosphates are lipophilic and therefore predicted to have a large volume of distribution and to rapidly distribute into tissue and fat. Thus, toxic effects of organophosphate would be expected to last longer in obese patients. We investigated the relationship between obesity and clinical course in 112 acute organophosphate-poisoned patients from an initial medical record review of 234 patients. One hundred twenty-two patients were excluded: 6 were children, 14 had an uncertain history of exposure and of uncertain agent, 10 were transferred to another hospital, 67 were discharged from the emergency department because their toxicity was mild, 21 had carbamate poisoning, and 4 did not have height or weight checked. Clinical features, body mass index, Glasgow Coma Scale, laboratory findings, serum cholinesterase activity, electrocardiogram finding, management, and outcomes were examined. The lipid solubility of the implicated organophosphate was characterized by its octanol/water coefficient. Forty of 112 patients were obese. Obese patients who were poisoned by high lipophilicity organophosphate compounds had a need for longer use of mechanical ventilation, intensive care unit care, and total length of admission. Body mass index can provide a guide to physicians in predicting clinical course and management in organophosphate-poisoned patients.

Chronic Hepatitis B (HB) is the main risk factor for chronic liver disease (CLD) and hepatocellular carcinoma (HCC) in many low-resource countries, where diagnosis is constrained by lack of clinical, histopathological and biomarker resources. We have used proteomics to detect plasma biomarkers that outperform α-Fetoprotein (AFP), the most widely used biomarker for HCC diagnosis in low-resource contexts. Deep-plasma proteome analysis was performed in HCC patients, patients with CLD and in HB-carrier controls from Thailand (South-East Asia) and The Gambia (West-Africa). Mass spectrometry profiling identified latent-transforming growth factor β binding-protein 2 (LTBP2) and Osteopontin (OPN) as being significantly elevated in HCC versus CLD and controls. These two proteins were further analyzed by ELISA in a total of 684 plasma samples, including 183 HCC, 274 CLD and 227 asymptomatic controls. When combined, LTBP2 and OPN showed an area under the receiver operating curve of 0.85 in distinguishing HCC from CLD in subjects with AFP

We demonstrate a facile synthesis of monodisperse magnetite (Fe3O4) nanoparticles (NPs) via a simple wet chemical route at 180°C using oleylamine (C18H37N), which serves as a solvent, ligand, and surfactant. The particles have a narrow size distribution centered at about 10 nm. To provide better electron conductivity and structural stability, the as-synthesized particles are given a carbon nanocoating by pyrolysis of the residual surfactant on their surface. This pyrolysis forms a uniform thin nanocoating on each particle, and a core/shell Fe3O4/carbon NP network was thus obtained. The core/shell Fe3O4/carbon electrode shows better reversible capacity, cycle life, and rate capability than a bare Fe3O4 NP electrode because of its efficient electron transport and stress relaxation provided by the thin carbon layer.

To evaluate associations between total serum γ-glutamyltransferase activity (GGT) and biomarkers of arteriosclerosis in the Multi-Ethnic Study of Atherosclerosis (MESA), including 6783 participants from four ethnic subgroups, i.e., White, Chinese, Black and Hispanic.Associations between fasting total serum GGT activity and oxidized low-density lipoproteins (oxLDL), interleukin-6 (IL-6), C-reactive protein (CRP), and soluble intercellular adhesion molecule-1 (sICAM-1) were assessed. Following evaluation of linear trends between GGT and biomarkers of interest, multivariable linear regression models were serially adjusted for age, gender, site, ethnicity (M1); M1+lifestyle variables (M2); M2+traditional cardiovascular risk factors plus medications (M3); and M3+metabolic status (M4). Interactions were evaluated between GGT and age and ethnicity in all models.Linear trends were positive and significant between GGT and oxLDL, IL-6, CRP and sICAM-1 in crude models, and trends remained significant in all ethnic subgroups for CRP (p0.0001) and sICAM-1 (p0.001), and for IL-6 except in the Chinese. Trends between GGT and oxLDL were significant in the entire cohort and the White subgroup (p0.0001), but not in other ethnic subgroups. Multivariable models demonstrated continuous strong, positive associations between GGT and CRP, IL-6 and sICAM-1. Associations between GGT and oxLDL were attenuated upon adjustment for LDL-C and other traditional risk factors. All models were attenuated with adjustment for metabolic status. No age interactions were evident.Our findings support the hypothesis that total serum GGT activity represents the impact of metabolic disease on vascular injury and atherosclerosis.

Objective:There is a possibility that the target blood pressure needs to be set differently according to the age and the degree of senility of the subjects of the elderly hypertension. The purpose of this study was to evaluate the safety and efficacy of treatment according to target blood pressure f

Mitochondrial function is crucial for the maintenance of cellular homeostasis under physiological and stress conditions. Thus, chronic exposure to environmental chemicals that affect mitochondrial function can have harmful effects on humans. We argue that the concept of hormesis should be revisited to explain the non-linear responses to mitochondrial toxins at a low-dose range and develop practical methods to protect humans from the negative effects of mitochondrial toxins. Of the most concern to humans are lipophilic chemical mixtures and heavy metals, owing to their physical properties. Even though these chemicals tend to demonstrate no safe level in humans, a non-linear dose-response has been also observed. Stress response activation, i.e., hormesis, can explain this non-linearity. Recently, hormesis has reemerged as a unifying concept because diverse stressors can induce similar stress responses. Besides potentially harmful environmental chemicals, healthy lifestyle interventions such as exercise, calorie restriction (especially glucose), cognitive stimulation, and phytochemical intake also activate stress responses. This conceptual link can lead to the development of practical methods that counterbalance the harm of mitochondrial toxins. Unlike chemical hormesis with its safety issues, the activation of stress responses via lifestyle modification can be safely used to combat the negative effects of mitochondrial toxins.

NiO/Ni/graphene nanocomposites were prepared using a simple and environmentally friendly method comprising an electrical wire pulse technique in oleic acid containing graphenes and subsequent annealing to form anodes for Li ion batteries. The control product of NiO/Ni nanocomposite was prepared under the same conditions and characterized by structural and electrochemical analysis. The obtained NiO/Ni/graphene nanocomposite particles had sizes of 5-12 nm and a high surface area of 137 m(2) g(-1). In comparison to NiO/Ni, NiO/Ni/graphene exhibited improved cycling performance and good rate capability. Reversible capacity was maintained at over 600 mA h g(-1) at 0.2 C and was attributed to the alleviation in volume change and improved electrical conductivity of NiO/Ni/graphene nanocomposites.

Aim: To evaluate associations between total serum GGT activity, metabolic risk factors and prevalent metabolic disease in MESA. Patients & methods: Continuous associations between GGT and fasting blood glucose (FBG), fasting insulin, HbA1c and Homeostasis Model Assessment Index of Insulin Resistance (HOMA–IR) were evaluated in the entire MESA cohort and in metabolic disease subgroups using linear regression models incrementally adjusted for age, gender, site, race, lifestyle, traditional risk factors and medications. Cross-sectional odds of prevalent impaired FBG, metabolic syndrome and Type 2 diabetes were calculated for GGT quintiles in the entire cohort and in subgroups defined by age (< or ≥65 years) and ethnicity. Results: In multivariable models, significant associations were present between GGT activity and FBG, fasting insulin, HbA1c and HOMA–IR, with the interaction between GGT and BMI affecting the association between GGT and HOMA–IR as well as the association between BMI and HOMA–IR (p < 0.0001). Adjusted odds ratios (95% CIs) of prevalent impaired FBG, metabolic syndrome and Type 2 diabetes for quintile 5 versus 1 in the entire cohort were 2.4 (1.7–3.5), 3.3 (2.5–4.5) and 2.8 (1.8–4.4), respectively (p < 0.0001). GGT associations weakened with age. The significance of linear trends for increased prevalent metabolic disease by increasing GGT quintile varied by ethnicity. Conclusion: GGT is strongly associated with both cardiovascular and metabolic risk factors, including prevalent metabolic disease, in the MESA cohort.

The goal of this work is to understand the structure and characteristics of technological knowledge flows between countries, institutions, and technology fields in the field of organic photovoltaic cells. This study was conducted in three stages: data collection, network creation, and network analysis. For network analysis, network visualization, network topological analysis, and node centrality analysis were performed in sequence. The network topological analysis revealed that all three citation networks, i.e., countries, institutions, and technology fields, are scale-free networks that follow the power law and display, to a greater or lesser extent, a more efficient knowledge transfer capability than a random network of the same size. The node centrality analysis showed that the United States, Japan, and Germany are the most important citation centers in the country citation network, while Boeing, Konarka Technologies, Eastman Kodak, and Sharp are the most important in the institution citation network, and the U.S. patent classification (USPC) classes of 136, 257, and 428 are the most important in the technology field citation network, each playing critical roles in each the network as core nodes. In this study, we applied various concepts of centrality to the analysis of individual nodes and found that the results from the network topological analysis and the node centrality analysis are not significantly different. The proposed analysis framework in this paper is applicable to different science and technology domains.

Multiphase nanowires composed of Cu3Ge, GeOx, and CuGeO3, obtained through the thermochemical reduction of CuGeO3, are investigated as anode materials for lithium-ion batteries. Initially, CuGeO3 nanowires are prepared by using a facile hydrothermal process without the use of any templates or surfactants. The as-prepared CuGeO3 nanowires are demonstrated to be single-crystalline with a diameter of around 70 nm and a length of 0.5–2 μm. Subsequently, multiphase Cu3Ge/GeOx/CuGeO3 nanowires are prepared through the controlled thermochemical reduction of the as-prepared CuGeO3 nanowires under a H2 atmosphere at 250 °C. Upon thermochemical reduction, the wire-shaped morphology is retained, but the phase partially transforms to a mixture of crystalline Cu3Ge nano-domains (

Objective: In May 2011, an interview with three United States Forces Korea veterans revealed that chemicals believed to be 'Agent Orange' were buried at Camp Carroll (situated in Waegwan, Chilgok-gun, Gyeongsangbuk-do, Korea) in 1978. Many hazardous chemicals, such as perchloroethylene (PCE), trichloroethylene (TCE), and organochlorines were subsequently found in a joint US-ROK environmental investigation, although dioxins or burial evidence related to 'Agent Orange' have been not uncovered. This study was carried out to investigate the relevance of hazardous chemical exposure and health effects of the residents around Camp Carroll. Methods: The authors conducted a health questionnaire survey among residents around Camp Carroll regarding Waegwan groundwater ingestion, length of residence in Waegwan, and physician-diagnosed disease history (such as cancer, hypertension, diabetes and etc.). Logistic regression was performed to identify the associations between hazardous chemical exposure and physician-diagnosed diseases. Results: Among the 5,320 residents, excluding those living outside the Waegwan area, 3,430 subjects age 30 and over were analyzed. Among females, upon correction of age, smoking history and Camp Carroll working history, a higher distribution in the Waegwan groundwater ingestion group was demonstrated for patients with physician-diagnosed cancer and hypertension. The odds ratios have a tendency to increase with increased length of Waegwan groundwater ingestion. Conclusions: This study may be limited by not adopting a cohort study for the evaluation of factors that may confound environmental exposure. Yet it is meaningful that the correlation between Waegwan groundwater ingestion and chronic diseases were found through regression analysis in female; and further, this outcome may be used as a sampling basis for a secondary epidemiologic study.

Objectives: As the suspicion was raised that ‘Agent Orange’ was reclaimed 30 years ago at Camp Carol, located in Waegwan, Gyeongsangbuk-do, the government conducted an investigation of the influence of environmental and health effects around Camp Carol through a public-private joint investigation team. As part of the investigation of population health effects, this study was carried out in order to observe changes and regional differences in diseases, particularly cancer, by year. Methods: We authors conducted an analysis of secondary health data, such as cancer registration data, mortality data, and health insurance data. We drew an age standardized incidence ratio (SIR), death rate (SDR), mortality ratio (SMR), and health care utilization rate using these data. Results: For gastric cancer in women, and other cancers in men, a significant increase in incidence was observed compared to the control area. For biliary tract cancer, gallbladder cancer, and thyroid cancer in women, and prostate cancer in men, a significant decrease in incidence was observed compared to the control area. In the national statistical analysis of data, such as health insurance data and mortality data, we did not observe a significant increase at the Waegwan region compared to other regions. Conclusions: We must consider the limitations of this study. Because thirty years have passed from the time of the estimated landfill of ‘Agent Orange’, recent national statistical data may not reflect the past real situation. Therefore, the monitoring of secondary data for health effects at the municipal level should be carried out continuously.

Objectives: This study describes the results of a mass screening and secondary questionnaire conducted among sampled residents around Camp Carroll. Methods: The subjects were sampled based on Waegwan groundwater ingestion history via a primary health questionnaire survey. However, the study population included voluntary participants and there were no grounds for disqualification. Among the 1,033 residents, excluding people living outside Waegwan, 844 subjects age 30 and over were analyzed. History of physician-diagnosed disease (including detailed history of cancer), eating habits, drinking and smoking histories were queried through questionnaires. Health screening consisted of a blood pressure check and blood test (complete blood cell, liver enzyme, lipid, blood sugar test, etc.). Results: The proportion of abnormal gamma-glutamyltransferase levels was higher in the groundwater ingesting female group than the non-ingesting female group. The odds ratios of the ingested '1 to 9 years' and '10 years and over' groups were 3.09 and 0.87, respectively. Proportions of hypertension in males, abnormal serum triglyceride levels in all and in females, and abnormal serum high density lipoprotein cholesterol levels in males were higher in the '10 to 29-year' resident group than in the '1 to 9 year' group. However, there were no significant trends according to length of residence. Conclusions: Physician-diagnosed prevalence and laboratory test results are not different by histories of Waegwan groundwater ingestion and by length of residence. Even if there are partially significant differences, they do not tend to follow increases of exposure amount and trends.

Since the cluster began to receive attention as a critical environmental factor in geographical economics, it has provided a major research methodology across multiple disciplines from industrial organization, strategic management, regional innovation system, and Triple Helix to virtual clusters. Network structure analysis (NSA) offers a common framework to observe clusters that have been studied separately from the viewpoint of industrial organization and strategic management. Industrial structure analysis, is based on the externality of a network and the resource-based view, focused on the inherent network capacity, have been combined with the study of structural changes through cluster NSA, to create a new direction for the growth of industry and individual firms. This study aims to analyze the correlation between the networking of structural change and a firm's performance by selecting a software industrial cluster as a representative case for the knowledge industry. We examine the network structural positions of each node during the cluster evolution process. This empirical study has significance for establishing a firm's growth strategy as well as supporting the policy about clusters, through outlining the dynamic evolution process of the networking activities in a knowledge industry cluster.

Due to worsening environmental conditions around the globe, firms have been investing a great deal of money in green technologies as a way of coping with the environmental crisis. This paper uses a unique data set based on the Korea Innovation Survey to examine the impact of green innovation on labor productivity, and the determinants of environmental activities in 2010. The empirical results show that green innovation intended for both firm and customer benefits has a positive effect on labor productivity. This finding means that firms need to implement firm-oriented green innovation as well as customer-oriented green innovation in order to increase their performance. Our findings also show that there are significant differences in aggregate green innovations depending on different firm sizes and industries. Specifically, large firms implement environmental activities more than small ones, and pollution-intensive industries tend to invest more in activities related to environmental technology. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.

There are substantial variations of relative risks (RR) in smoking-related mortality by country and time. We hypothesized the RRs in smoking-related mortality might differ depending on serum concentrations of persistent organic pollutants (POPs). We evaluated the associations of cigarette smoking with total mortality in 610 elderly (aged ≥ 70 yr) (702 elderly for organochlorine pesticides [OCPs]) after stratification by serum concentration of POPs, in the National Health and Nutrition Examination Survey (NHANES) 1999-2004 followed through 2006. Summary measures of POPs subclasses showed significant or marginally significant interaction with cigarette smoking on the risk of total mortality. P values for interaction were 0.069 for polychlorinated dibenzo-p-dioxins (PCDDs), 0.008 for polychlorinated biphenyls (PCBs), and 0.024 for OCPs. The effect of smoking on total mortality showed different patterns according to the serum concentration of some POPs. Former or current smokers had 1.4 to 2.9 times higher mortality rates compared with never smokers among participants with higher serum concentrations of POPs (2nd or 3rd tertiles). However, when the level of PCBs or OCPs were low (1st tertile), there were little positive associations between smoking and mortality. Our study suggests that the background exposure to several POPs may be related to variability in smoking-related total mortality.

For years, scientists from various disciplines have studied the effects of endocrine disrupting chemicals (EDCs) on the health and wellbeing of humans and wildlife. Some studies have specifically focused on the effects of low doses, i.e. those in the range that are thought to be safe for humans and/or animals. Others have focused on the existence of non-monotonic dose-response curves. These concepts challenge the way that chemical risk assessment is performed for EDCs. Continued discussions have clarified exactly what controversies and challenges remain. We address several of these issues, including why the study and regulation of EDCs should incorporate endocrine principles; what level of consensus there is for low dose effects; challenges to our understanding of non-monotonicity; and whether EDCs have been demonstrated to produce adverse effects. This discussion should result in a better understanding of these issues, and allow for additional dialogue on their impact on risk assessment.

This research has its roots in the hypothesis that the micro-level network phenomenon instigates increased system complexity and ultimately results in increased macroscopic instabilities. In order to validate this hypothesis, we perform step-by-step research on the impact of the “economic network” on its stability in the socio-economic ecosystem context. Along with social network analysis (SNA), which has traditionally been used in the social sciences, this research investigates the fundamental theories of network structure that have recently gained spotlight in physics as well. It analyzes the impact of the “economic network” on the volatility and stability of various economic systems, such as the real, financial, industrial, and spatial economies. It also attempts to discuss the network structures that promote stability. Finally, by applying and expanding the contemporary principles and theories in the complex network field to economic phenomena, this research seeks a sustainable socio-economic ecosystem to reduce systematic instability.

A facile approach for the synthesis of hybrid nanocomposite electrodes comprising pine-nut-shaped cupric oxide (CuO) particles and electrolytically exfoliated conducting graphene nanosheets (GNSs) for lithium ion battery applications is demonstrated. The GNSs were initially dispersed in aqueous solution, and then, Cu(OH)2 was synthesized by the reaction of CuSO4·5H2O, NH4OH, and NaOH. In the subsequent chemical reduction process, a controlled amount of hydrazine hydrate (N2H4·H2O) was added to the reaction mixture to obtain the CuO/GNS nanocomposite. Information about the phase, surface properties, and morphology of the CuO and CuO/GNS composite was obtained by X-ray diffraction, Brunauer–Emmett–Teller surface analysis, field-emission scanning electron microscopy, and high-resolution transmission electron microcopy. The electrochemical performance of the nanocomposite was evaluated by cyclic voltammetry and galvanostatic cycling. The nanocomposite synthesized by this method had a uniform morphology without aggregation and showed enhanced electrochemical performances.

By 2020, Korea has set itself the challenging target of reducing nationwide greenhouse gas emissions by 30%, more than the BAU (Business as Usual) scenario, as the implementation goal required to achieve the new national development paradigm of green growth. To achieve such a target, it is necessary to diffuse innovative technologies with the capacity to drastically reduce greenhouse gas emissions. To that end, the ripple effect of diffusing innovative technologies on the energy and environment must be quantitatively analyzed using an energy system analysis model such as the MARKAL (Market Allocation) model. However, energy system analysis models based on an optimization methodology have certain limitations in that a technology with superior cost competitiveness dominates the whole market and non-cost factors cannot be considered. Therefore, this study proposes a new methodology for overcoming problems associated with the use of MARKAL models, by interfacing with a forecasting model based on the discrete-choice model. The new methodology was applied to green car technology to verify its usefulness and to study the ripple effects of green car technology on greenhouse gas reduction. The results of this study can be used as a reference when establishing a strategy for effectively reducing greenhouse gas emissions in the transportation sector, and could be of assistance to future studies using the energy system analysis model.

Previous studies of technical competitive relationship have mostly focused on the analysis of one-directional impact of the technical attribute on market share. However, there is a cyclical feedback effect between the technical attributes and market share, and that means the small difference of competitiveness at the early phase of technology diffusion can greatly affect the final market share. As such, this study presents the system dynamics model which can forecast sales of innovative technology considering the feedback effect of market share on technical attributes. For that, the causal loop diagram among the various variables was defined using the econometric model applied and proven in various studies of the Bass diffusion model, discrete choice model, etc. to reinforce the theoretical background of the causal relationship among the variables of the forecasting model. Furthermore, infrastructure building scenarios and feedback effect scenarios were applied to the developed forecasting model to present the implication for successful adoption of green car technology from the infrastructure development view point.

Persistent organic pollutants (POPs) have been suggested to be linked to obesity. We have previously shown that less-chlorinated PCBs were positively related to fat mass, while highly-chlorinated PCBs were inversely related to obesity.The aim of the present evaluation is to investigate the relationship between retrospective assessed life-time change in body weight (20-70 years) with circulating POP levels measured at age 70 years.1016 subjects aged 70 years were investigated in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUSs) study. 16 PCBs and 3 OC pesticides were analyzed using HRGC/HRMS. Current body weight was measured and participants self-reported their weight at age 20.The average estimated weight change over 50 years was 14.4 kg. Both the sum of OC pesticide concentrations (4.3 kg more weight gain in quintile 5 vs. quintile 1, p0.0001) and the sum of the less-chlorinated PCBs were positively related to the estimated weight change (3.7 kg more weight gain in quintile 2 vs. quintile 1, non-linear relationship p=0.0015). In contrast, the sum of concentrations of highly-chlorinated PCBs were inversely related to estimated weight change (8.4 kg less weight gain in quintile 5 vs. quintile 1, p0.0001).High levels of OC pesticides and the less-chlorinated PCBs at age 70 were associated with a pronounced estimated weight change over the previous 50 years. However, the opposite was seen for highly-chlorinated PCBs. Differences in mode of action, toxicokinetics, non-linear relationships and reverse causation might explain these discrepancies.

As information technology used for simulation and virtual reality developed, there is a growing interest in animation technologies which will effectively deliver simulation results to users. Various efforts have been made to improve animation performance, like playback quality and speed, input-output speed and storage space reduction. However, earlier studies generally focused on image compression frame by frame. To significantly improve storage space and playback speed, animation data should be vectorized. Also, spatial and temporal duplication have to be removed. In this study, animation data structure was improved fundamentally through establishment of hierarchy and vectorization. Also Spatial and temporal duplication of animation data was removed through vectorization based on train route. As a result, storage space was reduced, input-output speed and playback speed were considerably improved. According to the test, additional Patternization which followed vectorization brought reduction of over 80% in storage space and input-output speed was quadrupled. Patternization technology can be used as a proper storage method of animation data, and can provide user-specific animation by small data transmission.

Background exposure to persistent organic pollutants (POPs), lipophilic xenobiotics that accumulate mainly in adipose tissue, has recently emerged as a new risk factor for cardiovascular diseases. This prospective study was performed to evaluate if plasma concentrations of selected POPs predict incident stroke among the elderly. Twenty‐one POPs (including 16 polychlorinated biphenyl (PCB) congeners, 3 organochlorine (OC) pesticides, 1 brominated diphenyl ether (BDE), and 1 dioxin) were measured in plasma collected at baseline in 898 participants aged 70 years of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). Stroke diagnosis was validated by hospital records. During the five year follow-up, 35 subjects developed hospital-treated stroke. After adjusting for known stroke risk factors, most PCBs with 4, 5, or 6 chlorine atoms, p,p′-DDE, trans-nonachlor, and octachlorodibenzo-p-dioxin significantly predicted the risk of stroke. Across quartiles of summary measures of PCBs and OC pesticides, the adjusted ORs were 1.0, 0.8 (95% confidence interval: 0.2–2.5), 1.2 (0.4–3.4), and 2.1 (0.7–6.2) for PCBs and 1.0, 1.2 (0.3–4.2), 2.3 (0.7–6.9), and 3.0 (1.0–9.4) for OC pesticides (P for trend=0.11 and 0.03, respectively). The adjusted ORs among participants ≥90th percentile of the summary measures were 5.5 (1.7–18.1) for PCBs and 4.0 (1.1–14.6) for OC pesticides; corresponding ORs for those ≥95th percentile were 7.8 (2.1–29.6) and 9.5 (2.3–38.9). Background exposure to POPs may play an important role in development or progression of stroke in the elderly. Keywords: Stroke, Persistent organic pollutants, Polychlorinated biphenyls, Organochlorine pesticides, Dioxin

Possible harm from endocrine disrupting chemicals (EDCs) in humans is speculated based on two types of evidence; 1) increasing trends of suspected diseases in ecological studies of populations and 2) findings from traditional epidemiological studies of individuals. However, ecological findings are not regarded as direct human evidence of the relation between EDCs and disease, while the evidence among epidemiological studies of individuals is often inconsistent. Thus, a criticism is that linking EDCs and health in human is naively presumed without solid evidence. However, human studies of EDCs are methodologically complex and understanding methodological issues will help to interpret findings from existing human studies and to properly design optimal human studies. The key issues are low reliability of exposure assessment of EDCs with short half-lives, EDC mixtures, possibility of non-monotonic dose-response relationships, non-existence of an unexposed group, difficulties in measuring exposure during critical periods, and interactions with established risk factors. Furthermore, EDC mixtures may affect human health through other mechanisms than traditional endocrine disruption, for example glutathione depletion or mitochondrial dysfunction. Given this complexity, the most plausible scenario in humans is that exposure to EDC mixtures leads to increasing risk of related diseases at the ecological level, but inconsistent associations would be expected in traditional epidemiological studies. Although epidemiologists have long relied on Bradford Hill's criteria to objectively evaluate whether associations observed in epidemiology can be interpreted as causal, there are challenges to use these criteria for EDCs, particularly concerning consistency across studies and the findings of linear dose-response relationships. At the individual level, compared to EDCs with short half-lives, epidemiological studies of EDCs with long half-lives among populations with a relatively low exposure dose range of exposure can likely produce relatively more reliable results, because the measurement of EDCs with long half-lives likely represents typical long-term exposure and populations with exposure in the low range of doses are likely to have a reference group closer to non-exposure.