The public perspective on renewable energy versus nuclear power for carbon neutrality in South Korea.

South Korea has legislated "2050 carbon neutrality" in 2021 and is currently implementing it, and debate is brewing over which to focus on as the main means of achieving it in the power generation sector: renewable energy (RE) or nuclear power (NP). This article aims to collect and analyze data on the public preference for RE versus NP. In a national survey of 1000 people, respondents were first asked which was preferred, RE or NP, and then asked to indicate the preference intensity along a 5-point scale. Of all the respondents, 60.3% preferred RE and 27.7% preferred NP. The preference for the former was about 2.2 times more than that for the latter. However, the intensity of the preference for NP was 1.3 times more than that for RE. Both the two-limit Tobit model and ordered probit model have been applied to analyzing the factors influencing the preference. The effects of some variables on the preference for RE over NP are explained, and implications from this are discussed. The findings can be used as a reference to determine the main means of implementation of carbon neutrality or to increase the public acceptance of the specified means.

The Psychomotor Cognition Test for Measurement of Sleepiness/Fatigue on a Touch Screen.

The Psychomotor Vigilance Test (PVT) is a simple and reliable performance test that measures sustained attention, alertness level, and fatigue level. The PVT is a convenient tool that can be used in real time in situ through a mobile device without the assistance of experts and therefore can be used to improve safety and prevent accidents. However, the original PVT is vulnerable to the subject's intentional concentration on the test, and the variance range among tests is narrow; these factors limit its usefulness in classifying the level of fatigue. This study overcome these limitations and develop the Psychomotor Cognition Test (PCT) by transforming the PVT into a tool that stably classifies fatigue levels, still requiring a short period of time. In the PCT, compared to the PVT, reaction time is significantly longer, and success rate is significantly lower (both p<0.0001). Whereas reaction time and success rate of the PVT do not show a significant correlation with fatigue level, those of the PCT show significant correlations with fatigue level, respectively (p<0.001). This study suggests that the PCT can be used in real time in situ as a risk management tool for workers performing dangerous tasks and can become an even more powerful tool when combined with other physiological indicators.

A Nonrandomized Phase 2 Trial of EG-Mirotin, a Novel, First-in-Class, Subcutaneously Deliverable Peptide Drug for Nonproliferative Diabetic Retinopathy.

Background and objectives: EG-Mirotin (active ingredient EGT022) targets nonproliferative diabetic retinopathy (NPDR), the early stage of retinopathy. EG-Mirotin reverses capillary damage before NPDR progresses to an irreversible stage. EG-Mirotin safety and efficacy were investigated in patients with type 1 or type 2 diabetes mellitus and moderate to severe NPDR. Methods: In this open-label, single-arm, single-center, exploratory phase II study, 10 patients (20 eyes) received EG-Mirotin once a day (3 mg/1.5 mL sterile saline) for 5 days and were evaluated for ischemic index changes and safety. End of study was approximately 8 ± 1 weeks (57 ± 7 days) after the first drug administration. Results: EG-Mirotin injections were well tolerated, with no dose-limiting adverse events, serious adverse events, or deaths. Four treatment-emergent adverse events (TEAEs) unrelated to the investigational drug were observed in 2 out of 10 participants (20%) who had received the investigational drug. The overall average percent change in ischemic index at each evaluation point compared with baseline was statistically significant (Greenhouse-Geisser F = 9.456, p = 0.004 for the main effect of time), and a larger change was observed when the baseline ischemic index value was high (Greenhouse-Geisser F = 10.946, p = 0.002 for time × group interaction). Conclusions: The EG-Mirotin regimen established in this study was shown to be feasible and safe and was associated with a trend toward potential improvement in diabetes-induced ischemia and retinal capillary leakage.

Economic benefits of preventing bird collisions in South Korea: findings from a choice experiment survey.

Bird deaths due to collisions with artificial structures, such as glass windows of buildings and transparent noise barriers, are continuing to occur in South Korea. The government is trying to prevent bird collisions by increasing the attachment of specially designed tapes to help birds avoid windows. This article estimates the economic benefits arising from the prevention of collisions by applying a choice experiment (CE). For this purpose, a CE survey of 1000 South Korean interviewees was conducted. The four attributes to be attached with the tapes for the CE application were a transparent soundproof wall window on an expressway, a transparent soundproof wall window on a general road, a glass window in a public building, and a glass window in a private building. The unit was the percentage of each structure with the tapes attached to the window. The marginal values of a one-unit (1%p) increase in each attribute were computed to be KRW 534 (USD 0.46), KRW 233 (USD 0.20), KRW 1,318 (USD 1.13), and KRW 12,930 (USD 11.05), respectively. This quantitative information will be an important reference for implementing the prevention policy. For example, based on the collision prevention of 1000 birds per structure, the priority for attaching tapes can be placed in the order of expressways, public buildings, private buildings, and general roads.

Fabrication of Salvinia-inspired surfaces for hydrodynamic drag reduction by capillary-force-induced clustering.

For decades, bioinspired functional materials have been attracting the interest of many researchers for their remarkable characteristics. In particular, some plant leaves are well known for their inherent superhydrophobic nature. Salvinia molesta, a free-floating aquatic fern, has egg-beater-shaped hierarchical trichomes on its surface of leaves. Due to the unique structure and complex wettability of the hairs, this plant has the ability to maintain a stable thick air layer upon the structure when it is submerged underwater. Often referred to as the "Salvinia Effect," this property is expected to be suitable for use in hydrodynamic drag reduction. However, due to the complex shape of the trichome, currently applied fabrication methods are using a three-dimensional printing system, which is not applicable to mass production because of its severely limited productivity. In this work, artificial Salvinia leaf inspired by S. molesta was fabricated using a conventional soft lithography method assisted with capillary-force-induced clustering of micropillar array. The fabrication method suggested in this work proposes a promising strategy for the manufacturing of Salvinia-inspired hydrodynamic drag reduction surfaces.

Public willingness to pay for eradicating a harmful marine organism: the case of Aurelia aurita in South Korea.

Aurelia aurita (AA), a legally registered harmful marine organism in South Korea, is damaging marine human leisure activities, local residents' tourism income, fisheries, and cooling water intake at power plants. The government is therefore seeking to eradicate AA by removing AA-attached larvae (polyps). This article looks into the public willingness to pay (WTP) for the eradication, utilizing a contingent valuation. For the sake of eliciting the WTP response, the one-and-one-half-bounded (OB) model was adopted. For comparison, the single-bounded (SB) model, which uses only the response to the first question in the OB model, was also applied. A spike model with a considerable plausibility that could explicitly deal with zero WTP responses was employed. Consequently, the estimation results of the SB model were used for further policy analysis. The household average WTP was estimated as KRW 3,911 (USD 3.49) per year, securing statistical significance. The national value was KRW 80.46 billion (USD 71.71 million) per annum. This figure can be interpreted as public value of the AA eradication project and used as essential basic data to evaluate the economic feasibility of implementing the project. Some factors such as income and education level significantly positively affected the intention of paying a suggested bid.

The antibacterial activity of mineral trioxide aggregate containing calcium fluoride.

Background/purpose: Because complete microbial elimination of the infected root canal system is nearly impossible to achieve, the use of root canal fillings with antibacterial effects may help to minimize intracanal infections. Our previous study, MTA modified by CaF2 addition, improved the biocompatibility and mineralization potential of human dental pulp cells without adverse effect on the physical properties. In this study, the antibacterial effect of MTA after CaF2 addition was evaluated for use as a root canal sealer. The objective of this study was to evaluate the antibacterial activity of MTA after the addition of CaF2. Materials and methods: The antibacterial activities of MTA and MTA-CaF2 mixture against Enterococcus faecalis (E. faecalis), Porphyromonas endodontalis (P. endodontalis), and Porphyromonas gingivalis (P. gingivalis) were investigated with MTA-CaF2 powder and eluates. The bacterial growth was measured by optical density using a spectrophotometer and the bacterial colony counting. Results: MTA inhibited the growth of E. faecalis, P. endodontalis, and P. gingivalis, and the addition of CaF2 improved this antibacterial effect in a concentration dependent manner (p < 0.05). E. faecalis was more resistant to MTA-CaF2 than the other groups of bacteria. Conclusion: The addition of more than 5% CaF2 to MTA can increase the antibacterial activity.

Monetary valuation of air quality improvement with the stated preference technique: A multi-pollutant perspective.

Air pollution is an important global issue, and governments are making efforts to reduce air pollutant emissions. The elaborate calculation of the social costs of air pollution is essential for justifying the substantial public expenditure on air pollution control policies. This study aims to derive the monetary value of reducing different kinds of air pollutants through the public's willingness to pay (WTP). A choice experiment survey is conducted to examine the public perception of air quality improvement, and the collected stated preference data are analysed with the hierarchical Bayesian logit model. The analysis results show that the public valuation of the emission reduction differs for individual pollutants. On average, the monetary value of one ton of emission reduction follows the order of PM2.5, PM10, SOx, TSP, NOx, and VOC. Based on the elicited WTP, the economic feasibility of the two air pollutant reduction plans of the South Korean Government is assessed. The benefit-to-cost ratio of the plans is 0.61 and 0.66, respectively, based on the mean WTP, indicating that they are not economically feasible at the moment. Implications for the efficient budget allocation of air pollution control policies are provided based on the results.

Environmental conservation value of an endangered species: the case of Cypripedium Japonicum.

The South Korean government is seeking information on the environmental conservation value (ECV) of Cypripedium japonicum, a plant on the first-level priority endangered species list of the Korea Ministry of Environment, as well as on the Red List of the International Union for Conservation of Nature. This research paper aims to assess the ECV by employing contingent valuation (CV) to elicit people's willingness to pay (WTP) for its conservation. To achieve this aim, in May 2020, a CV survey of 1,000 interviewees in South Korea was carried out employing a closed-ended question. The average household WTP is estimated to be KRW 3,770 (USD 3.07) per annum and secures statistical significance. From a national point of view, using information on the national population, this value comes to KRW 76.72 billion (USD 62.42 million) per year. Although the cost of conserving the species has not yet been accurately estimated, the ECV seems to be larger than the cost of conservation. Thus, it is socially desirable to conserve Cypripedium japonicum, and the conservation should be carried out in a stable and continuous manner.

Surface roughness and chemical composition changes of resin-modified glass ionomer immersed in 0.2% sodium fluoride solution.

BACKGROUND/PURPOSE: Glass ionomers undergo degradation when exposed to fluoride, which changes the physico-chemical characteristics of the materials. The purpose of this study was to evaluate the surface changes of resin-modified glass ionomer (RMGI) when immersed in a sodium fluoride (NaF) solution according to pH and time. MATERIALS AND METHODS: 120 RMGI specimens were prepared, and 30 specimens were placed in four types of storage solutions for four weeks; pH 7 artificial saliva with or without 0.2% NaF (As7 and NaF7), pH 5 artificial saliva with or without 0.2% NaF (As5 and NaF5). Interferometry and microscopy were performed to evaluate the surface roughness and topography, while spectroscopy was used to analyze the chemical composition changes. RESULTS: Rougher topography and increased roughness was exhibited in NaF groups, owing to the disintegration of the polysalt matrix. Reduced Sr and F was exhibited in all groups, whereas NaF group showed a decrease in Al and inorganic components. CONCLUSION: This study suggest that excessive use of fluoride therapy could lead to severe degradation of RMGI.

Public preference toward an energy transition policy: the case of South Korea.

South Korea is pursuing an energy transition policy (ETP) of expanding the use of renewable energy and natural gas and decreasing that of nuclear energy and coal in total generation. An investigation of whether the public is for or against the ETP is needed by the government. This article explores the public preference toward the ETP employing the data collected through a survey of 1000 individuals. They were asked to reveal their preference for the ETP on a five-point scale in the survey. Overall, there are more advocates of the ETP than those who opposed it. For the purpose of analyzing the determinants of advocacy and opposition of the ETP, an ordered probit model is employed. The results suggest that people living in the Seoul Metropolitan area think that the environment is more important than new jobs, or know the renewable energy 100% campaign before the survey is more favorable to the ETP than others. However, people who use electricity for heating tend to be negative about the ETP. As the age increases, people approve of the ETP, but when age goes beyond a certain level, they oppose it.

What do we know about public acceptance of designating marine protected area? The case of Jaran Bay in South Korea.

The South Korean Government is considering designating Jaran Bay, the habitat of the endangered marine species, Neophocaena asiaeorientalis, as a marine protected area. The Government needs information about public acceptance and the economic benefits of the designation. To unveil the information, this article aims to examine the public willingness to pay (WTP) using a contingent valuation based on a nationwide survey of 1000 households. As a WTP elicitation method, the one-and-one-half-bounded question format of asking an interviewee whether she/he has the intention of paying a presented bid through annual income tax was adopted. The WTP for the designation was statistically significantly estimated to be KRW 2665 (USD 2.27) per year per household. The estimate of the annual national value amounted to KRW 53 billion (USD 45.30 million). This value is by no means small, but it would take a huge amount of effort to elicit public consensus on the designation considering that a significant proportion of respondents (64.4%) revealed zero WTP.

Public perspectives on reducing the environmental impact of onshore wind farms: a discrete choice experiment in South Korea.

Onshore wind farms have the advantage of a lower cost than offshore wind farms, but their negative environmental impact has been pointed out as a problem. If this environmental impact can be lessened, public acceptance of onshore wind farms will be significantly increased. This study investigates public attitudes to the lessening of the environmental impact of onshore wind farms, focusing on three specific attributes: visual impact, ecosystem destruction and noise pollution. The area of empirical analysis is South Korea, and the choice experiment data are analysed using a mixed logit model to reflect the heterogeneity of the respondents' preferences. The analysis results show that there is considerable heterogeneity in respondents' preferences and that they regard the visual impact and the ecosystem destruction as more important than the noise pollution. Respondents are willing to pay KRW 197, KRW 138 and KRW 69 for a 1% improvement in visual impact, a 1% reduction in ecosystem destruction and a 1-dB reduction in noise, respectively. The results of the scenario analysis show that simultaneous improvements in the three attributes should be made in order to ensure a certain level of public acceptance. Related policy implications are provided based on the analysis results.

How much value do people place on preserving the Seocheon coastal wetland in South Korea?

The ecosystem of the Seocheon coastal wetland (SCW), one of the wetland protected areas in South Korea, was registered in the Ramsar Wetlands in 2009 as an area rich in biodiversity and inhabited by endangered wild animals and plants. Since then, preserving the ecosystem of the SCW has emerged as an important task. Thus, the South Korean government is carrying out various research and management projects to preserve the ecological integrity of the SCW. This article aims to analyze public willingness to pay for preserving the SCW. For this purpose, 1000 households were surveyed, applying the contingent valuation (CV) method during September 2017. The respondents clearly understood the CV question and gave meaningful answers. The results show that an average value for the preservation was statistically significantly estimated to be KRW 2341 (USD 2.04) for all respondents. The national value expanded from the sample to the population is worth KRW 47.79 billion (USD 42.15 million) per year. Therefore, it can be seen that the public have sufficient acceptance for preserving the SCW.

Does combined heat and power mitigate CO2 emissions? A cross-country analysis.

Combined heat and power (CHP), which produces both heat and electricity at the same time, is so efficient that it can reduce energy use and emit less carbon dioxide (CO2) than conventional fossil fuel use. This article attempts to look empirically into the impact of CHP share in total electricity generation on CO2 emissions in a cross-country context. Data from 35 countries during the period 2009-2015 are used. For this purpose, the variable of CO2 emissions is regressed on three variables of constant, gross domestic product, and CHP share using two robust estimators. The results show that the level of CHP share of a country affects the level of its CO2 emissions negatively. That is, CHP leads to less CO2 emissions.

Assessing the external benefits of contaminated soil remediation in Korea: a choice experiment study.

Korean government has made and will continue to make a considerable investment in contaminated soil remediation to rectify the problems that arise from soil pollution. Quantitative information on the benefits of contaminated soil remediation is widely demanded by the public as well as the government. This article aims to assess the external benefits of contaminated soil remediation. A survey of 1000 randomly selected households was undertaken in Korea. The results show that the marginal willingness to pay values for a 1% decrease in human health hazard, a 1% improvement in biodiversity restoration, and 1000 new job creation by contaminated soil remediation are estimated to be KRW 204 (USD 0.17), 593 (0.50), and 238 (0.20) per household per year. The findings can provide policy-makers with useful information for both evaluating and planning the contaminated soil remediation.

Development of a Web-Based Nationwide Korean Pediatric Dental Sedation Registry.

OBJECTIVE: Finding a balance between sedation efficacy and safety remains an ongoing challenge. In children, the risk of sedation-related complications is relatively high. It is of utmost importance to determine the factors related to improved overall sedation outcomes. However, most previous reports have been based on small samples at single institutions. The Korean Academy of Pediatric Dentistry (KAPD) developed a Korean Pediatric Dental Sedation Registry using a web-based platform. STUDY DESIGN: Specialists in pediatric dental sedation selected the itemized list included within the registry through an extensive literature review. The web-based registry was built into the KAPD homepage to facilitate easy access to the sedation data. All teaching and university hospitals agreed to participate in the Korean Pediatric Dental Sedation Registry. CONCLUSION: This is the first attempt to collect sedation data on a nationwide scale in the field of pediatric dentistry. The sedation database established with the registry may facilitate standardizing and improving pediatric dental sedation clinical practices.

Analysis of Neutron Production in Passively Scattered Ion-Beam Therapy.

A new treatment facility for heavy ion therapy since 2010 was constructed. In the broad beam, a range shifter, ridge filter and multi leaf collimator (MLC) for the generation of the spread-out Bragg peak is used. In this case, secondary neutrons produced by the interactions of the ion field with beam-modifying devices (e.g. double-scattering system, beam shaping collimators and range compensators) are very important for patient safety. Therefore, these components must be carefully examined in the context of secondary neutron yield and associated secondary cancer risk. In this article, Monte Carlo simulation has been carried out with the FLUktuierende KAskade particle transport code, the fluence and distribution of neutron generation and the neutron dose equivalent from the broad beam components are compared using carbon and proton beams. As a result, it is confirmed that the yield of neutron production using a carbon beam from all components of the broad beam was higher than using a proton beam. The ambient dose by neutrons per heavy ion and proton ion from the MLC surface was 0.12-0.18 and 0.0067-0.0087 pSv, respectively, which shows that heavy ions generate more neutrons than protons. However, ambient dose per treatment 2 Gy, which means physical dose during treatment by ion beam, is higher than carbon beam because proton therapy needs more beam flux to make 2-Gy prescription dose. Therefore, the neutron production from the MLC, which is closed to the patient, is a very important parameter for patient safety.

Rhus javanica Linn protects against hydrogen peroxide­induced toxicity in human Chang liver cells via attenuation of oxidative stress and apoptosis signaling.

Rhus javanica Linn, a traditional medicinal herb from the family Anacardiaceae, has been used in the treatment of liver diseases, cancer, parasitic infections, malaria and respiratory diseases in China, Korea and other Asian countries for centuries. In the present study, the protective effects of R. javanica ethanolic extract (RJE) on hydrogen peroxide (H2O2)-induced oxidative stress in human Chang liver cells was investigated. The cell cytotoxicity and viability were assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The activities of superoxide dismutase (SOD) and catalase (CAT) were measured using respective enzymatic kits. Cell cycle analysis was performed using flow cytometric analysis. The protein expression levels of p53, B-cell lymphoma (Bcl)-2, Bcl-2-associated X protein (Bax) and caspase-3 were assessed by western blotting. Human Chang liver cells were treated with different concentrations (0.1, 0.3 or 0.5 mg/ml) of RJE, and were subsequently exposed to H2O2 (30 µM). Treatment with H2O2 (30 µM) significantly induced cytotoxicity (P<0.05) and reduced the viability of the Chang liver cells. However, pretreatment of the cells with RJE (0.1, 0.3 or 0.5 mg/ml) significantly increased the cell viability (P<0.001 at 0.5 mg/ml) in a concentration-dependent manner following H2O2 treatment. Furthermore, pretreatment with RJE increased the enzyme activities of SOD and CAT, and decreased the sub-G1 growth phase of the cell cycle in response to H2O2-induced oxidative stress (P<0.001 at 0.3 and 0.5 mg/ml H2O2). RJE also regulated the protein expression levels of p53, Bax, caspase-3 and Bcl-2. These results suggested that RJE may protect human Chang liver cells against oxidative damage by increasing the levels of antioxidant enzymes and regulating antiapoptotic oxidative stress mechanisms, thereby providing insights into the mechanism which underpins the traditional claims made for RJE in the treatment of liver diseases.

A survey of the intravenous sedation status in one provincial dental clinic center for the disabled in Korea.

BACKGROUND: The objective of the present study was to examine the status of patients who had received dental treatment under intravenous (IV) sedation at Chungnam Dental Clinic for the Disabled in Korea from its inception to the present time, and to review the analysis results. METHODS: Retrospective analysis was performed on 305 cases of patients who had received dental treatments under IV sedation between January 2011 and May 2016. The analysis examined the patient's sex, age, primary reason for IV sedation, duration of anesthesia and dental treatment, type of dental treatment performed, number of clinical departments involved in the dental treatment and level of multidisciplinary cooperation, and annual trends. RESULTS: Most dental treatments using intravenous sedation were performed on medically disabled patients or dentally disabled patients with an extreme gag reflex or dental phobia. The mean duration of IV sedation was 72.5 min, while the mean duration of treatment was 58.0 min. The types of dental treatments included surgical treatment (n = 209), periodontal treatment (n = 28), prosthodontic treatment (n = 28), restorative treatment (n = 23), implant surgery (n = 22), endodontic treatment (n = 9), reduction of temporomandibular joint dislocation (n = 1), and treatment of traumatic injuries (n = 1), with treatments mostly performed on adult patients. CONCLUSIONS: With increasing demand for minimally painful treatment, cases using IV sedation are on an upward trend and are expected to continue to increase.