22 research outputs found
The Effects of Air Pollution on Mortality in South Korea
AbstractIt is well known that air pollution has the negative effect on human health. This study is dealt with the relationship between air pollutant level and standardized mortality between 2005 and 2013 in Korea. The standardized mortality are collected by the 251 administrative districts using KOSIS (Korean Statistical Information Service) and the air pollutant data collected from air pollutant monitoring sites. The statistical interpolation technique is adapted to solve the problem of spatial misalignment between air pollutant and administrative districts. In addition, SaTScan is used to detecting the high relatively risk area based on spatial and temporal characteristics. It can help determining other external factors to mortality
Genetic Diversity of Insulin Resistance and Metabolic Syndrome
A key in the etiology of a cluster of metabolic syndrome such as hyperglycemia, dyslipidemia, and obesity is known for insulin resistance, which is becoming a major global public health problem. Extensive studies have revealed many genetic factors for both insulin resistance and the components of metabolic syndrome. Advanced modern genotyping methods including genome-wide association studies and next-generation sequencing have allowed for the identification of both common and rare genetic variants related to these chronic disease-associated traits. Multiple genotype–phenotype studies are also needed to identify new and accurate genetic biomarkers in these conditions. The purpose of this chapter is to present genetic variants related to the pathogenesis of metabolic syndrome and insulin resistance and is to review the relevance between insulin resistance and metabolic syndrome clusters in terms of genetic diversity
Surface plasma with an inkjet-printed patterned electrode for low-temperature applications
Abstract The global health crisis caused by the recent pandemic has led to increasing social demand for ‘new normal’ sanitizing and disinfecting facilities to fit our ‘new normal’ lives. Here, we introduce an inkjet-printed, thin-film plasma source applicable to dry disinfection processes. In contrast to conventional plasma reactors, the merits of plasma produced on a film include disposability, cost-effectiveness, and applicability to high-dimensional objects such as the human body. The developed flexible plasma film can be applied to a wide variety of shapes via origami—remaining plasma stable even when bent. However, electrode degradation has been a practical issue in the long-term operation of inkjet-printed plasma sources, which is troublesome from application perspectives. We focus on making the inkjet-printed electrode more plasma stress-resistant, thereby increasing its lifespan from a few minutes to two hours of continuous operation with optimal inkjet printing and passivation, thus increasing the practicality of the source. Considering the fact that ozone and nitrogen oxides are selectively produced by plasma, we implement a disposable pouch-type plasma source and examine its usefulness in extending the shelf life of food
Electron characterization in weakly ionized collisional plasmas: from principles to techniques
Weakly ionized plasmas at or near 1 atm pressure, or atmospheric-pressure plasmas, have received increasing attention due to their scientific significance and potential for use in a variety of applications, particularly for medicine, agriculture, and food. However, there is a large imbalance between scientific research on plasma physics and applications, which is partly due to the considerable differences in the characteristics of these plasmas compared with those of low-pressure plasmas. This discrepancy is particularly related to the difficulty in performing plasma diagnostics for highly collisional plasmas. Information on electrons (such as the electron density and temperature) is essential since electrons play a dominant role in the generation of active species related to the physical and chemical processes inside the plasma. So far, limited diagnostics have been available for electrons such as Thomson scattering and optical emission diagnostics based on equilibrium models. Here, we review the available diagnostic methods along with their merits and limitations for characterizing electrons in weakly ionized collisional plasmas. Particular attention is paid to continuum radiation-based spectroscopy, which facilitates multidimensional imaging of electron density and temperature. The future impact of these plasmas on relevant fields (i.e. laboratory and industrial plasmas and their applications) is also addressed
Effects of dielectric barrier discharge plasma on pathogen inactivation and the physicochemical and sensory characteristics of pork loin
This study aimed to evaluate the use of a dielectric barrier discharge (DBD) plasma system to improve the safety of pork loins. When pork loin was exposed to DBD plasma with the input gases He and He + O2,the population of Escherichia coli was reduced by 0.26 and 0.50 log cycles following a 5-min treatment and by 0.34 and 0.55 log units following a 10-min treatment, respectively. That of Listeria monocytogenes was also reduced from 0.17 to 0.35 and 0.43 to 0.59 log cycles when the samples were exposed to DBD for 5 and 10 min using He and He + O2, respectively. The pH and L*-values (lightness) of the samples decreased significantly with DBD plasma treatment, but a*- (redness) and b*-values (yellowness)exhibited no obvious changes. Lipid oxidation, measured by TBARS values, was greater in samples with He þ O2 than in other samples. Significant reductions in sensory quality parameters (appearance, color,odor, acceptability, etc.) were observed in DBD-treated samples. These results indicate that the DBD plasma system has potential for use in sanitizing pork loins by inactivation of foodborne pathogens,although the effect was limited. In order to meet market requirements, however, a method to overcome sensory deterioration of pork loins should be developed and applied.N
Microbial safety and quality attributes of milk following treatment with atmospheric pressure encapsulated dielectric barrier discharge plasma
This study evaluated the microbial and physicochemical characteristics of milk that was treated with encapsulated dielectric barrier discharge (DBD) plasma. Encapsulated DBD plasma was generated in a plastic container (250 W, 15 kHz, ambient air) and DBD plasma treatment was applied to milk samples for periods of 5 and 10 min. The total aerobic bacterial count in the untreated control sample was 0.98 log CFU/mL. Following plasma treatment, no viable cells were detected in the milk samples. When milk samples were inoculated with Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, plasma treatment for 10 min resulted in a reduction in bacterial counts by approximately 2.40 log CFU/mL. The pH of the sample milk was found to decrease after the 10-min plasma treatment. Hunter color La and b* values of milk increased, and the a* value decreased as a result of the plasma treatment. The production of 2-thiobarbituric acid reactive substances increased slightly, but not significantly, following plasma treatment. The results of this study indicate that encapsulated DBD plasma treatment for less than 10 min improved the microbial quality of milk with slight changes in physicochemical quality of milk. (C) 2014 Elsevier Ltd. All rights reserved.N
Evaluation of pathogen inactivation on sliced cheese induced by encapsulated atmospheric pressure dielectric barrier discharge plasma
Pathogen inactivation induced by atmospheric pressure dielectric barrier discharge (DBD) (250 W, 15 kHz, air discharge) produced in a rectangular plastic container and the effect of post-treatment storage time on inactivation were evaluated using agar plates and cheese slices. When agar plates were treated with plasma, populations of Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes showed 3.57, 6.69, and 6.53 decimal reductions at 60 s, 45 s, and 7 min, respectively. When the pathogens tested were inoculated on cheese slices, 2.67, 3.10, and 1.65 decimal reductions were achieved at the same respective treatment times. The post-treatment storage duration following plasma treatment potently affected further reduction in pathogen populations. Therefore, the newly developed encapsulated DBD-plasma system for use in a container can be applied to improve the safety of sliced cheese, and increasing post-treatment storage time can greatly enhance the system's pathogen-inactivation efficiency. (C) 2014 Elsevier Ltd. All rights reserved.N
Evaluation of the treatment of both sides of raw chicken breasts with an atmospheric pressure plasma jet for the inactivation of escherichia coli
Atmospheric pressure plasma (APP) is an emerging nonthermal microbial inactivation technique. In this study, agar and raw chicken breast were inoculated with Escherichia coli and treated with an APP jet based on cold arc plasma. The aim of this study was to investigate the optimum conditions for the plasma treatment of an APP jet in order to maximize the efficiency of E. coli inactivation. The combination of N-2+O-2 (10 standard cubic centimeters per minute) and a longer treatment time (10 min) resulted in the highest inactivation of E. coli on agar plates with an optimum treatment distance of 20 mm. The samples in dry and wet conditions showed similar reductions in E. coli count when one side of the samples was treated at a given treatment time. Treating both sides-2.5 min on each side-resulted in a higher growth inhibition of E. coli than treatment of a single side only for 5 min. However, there was no significant difference between one-side treated samples (10 min) and both-sides treated samples (5+5 min). When the concentration of E. coli in the chicken breast sample was 10 4 colony-forming units (CFU)/g, the reduction rate of the E. coli was the highest, followed by 10(5), 10(6), and 10(7) CFU/g; however, no difference was found between 10(3) and 10(4) CFU/g. In conclusion, various treatment conditions may affect the inactivation efficiency of E. coli. In the present study, the optimum condition was determined as the treatment distance of 20 mm and longer treatment time (10 min) with the addition of oxygen to the nitrogen gas flow. Furthermore, the cell concentration of sample was an important parameter for the efficacy of the inactivation process.N
Pathogen inactivation and quality changes in sliced cheddar cheese treated using flexible thin-layer dielectric barrier discharge plasma
Cheese is recognized as a source of food-borne disease outbreaks worldwide. In this study the inactivation of pathogens on sliced cheddar cheese by using flexible thin-layer dielectric barrier discharge (DBD) plasma and its effect on food quality have been described. Escherichia coli 0157:H7, Listeria monocytogenes, and Salmonella Typhimurium populations on agar plates were significantly reduced by plasma treatment. The level of these microorganisms on sliced cheddar cheese in response to 10-min plasma treatment significantly decreased by 3.2, 2.1, and 5.8 Log CFU/g, respectively. The pH and L*-values decreased whereas thiobarbituric acid reactive substances values and b*-values increased significantly with extended exposure of the sliced cheddar cheese to DBD plasma. The total color difference (Delta E), sensory appearance and color scores showed no significant differences between DBD plasma-treated and untreated sliced cheddar cheese. However, significant reductions in flavor and overall acceptance as well as an increase in off-odor were observed. These results indicate that flexible thin-layer DBD plasma can be used to sanitize food products, but conditions should be optimized for industrial applications. (C) 2014 Elsevier Ltd. All rights reserved.N