• The Plant Pathology Journal
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• v.30 no.3
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• pp.236-244
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• 2014

The plant pathogen Fusarium graminearum causes Fusarium head blight in cereal crops and produces mycotoxins that are harmful to animals and humans. For the initiation and spread of disease, asexual and sexual reproduction is required. Therefore, studies on fungal reproduction contribute to the development of new methods to control and maintain the fungal population. Screening a previously generated transcription factor mutant collection, we identified one putative $C_2H_2$ zincfinger transcription factor, pcs1, which is required for both sexual and asexual reproduction. Deleting pcs1 in F. graminearum resulted in a dramatic reduction in conidial production and a complete loss of sexual reproduction. The pathways and gene ontology of pcs1-dependent genes from microarray experiments showed that several G-protein related pathways, oxidase activity, ribosome biogenesis, and RNA binding and processing were highly enriched, suggesting that pcs1 is involved in several different biological processes. Further, overexpression of pcs1 increased conidial production and resulted in earlier maturation of ascospores compared to the wild-type strain. Additionally, the vegetative growth of the overexpression mutants was decreased in nutrient-rich conditions but was not different from the wild-type strain in nutrient-poor conditions. Overall, we discovered that the pcs1 transcription factor positively regulates both conidiation and sexual reproduction and confers nutrient condition-dependent vegetative growth.

• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.236-243
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• 2022

Background: In the case of multiple exposures to different types of heavy metals, such as the conditions faced by residents living near a smelter, it would be preferable to group hazardous substances with similar characteristics rather than individually related substances and evaluate the effects of each group on the human body. Objectives: The purpose of this study is to evaluate the utility of factor analysis in the assessment of health effects caused by exposure to two or more hazardous substances with similar characteristics, such as in the case of residents living near a smelter. Methods: Heavy metal concentration data for 572 people living in the vicinity of the Janghang smelter area were grouped based on several subfactors according to their characteristics using factor analysis. Using these factor scores as an independent variable, multiple regression analysis was performed on health effect markers. Results: Through factor analysis, three subfactors were extracted. Factor 1 contained copper and zinc in serum and revealed a common characteristic of the enzyme co-factor in the human body. Factor 2 involved urinary cadmium and arsenic, which are harmful metals related to kidney damage. Factor 3 encompassed blood mercury and lead, which are classified as related to cardiovascular disease. As a result of multiple linear regression analysis, it was found that using the factor index derived through factor analysis as an independent variable is more advantageous in assessing the relevance to health effects than when analyzing the two heavy metals by including them in a single regression model. Conclusions: The results of this study suggest that regression analysis linked with factor analysis is a good alternative in that it can simultaneously identify the effects of heavy metals with similar properties while overcoming multicollinearity that may occur in environmental epidemiologic studies on exposure to various types of heavy metals.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.316-320
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• 1997

Phenolic acids are regarded as harmful materials in food and environment science but recently, as useful materials, and thus adsorption is recommended as an effective separation technique to recover or remove phenolic acids from diluted solution. If the adsorbed phenolic compounds were useful materials, the materials should be recovered through desorption. Desorption using supercritical carbon dioxide(SC-$CO_2$) was tried to separate food-borne phenolic acids from charcoal in single solute system. In the comparisons of desorption amounts, gallic acid had the lowest lolubiligy to SC-$CO_2$. Gallic acid has more hydroxy functional groups than the other phenolic acids, which was immiscible with nonpolar SC-$CO_2$. Ferulic acid was yielded more than p-coumaric acid, because ferulic acid had much bigger molecular weight, which was affected more by van der Waas force. It was found that the most affecting factor on desorption amounts was the solubility of phenolic acids to SC-$CO_2$. The second affecting factor was van der Waals force. Response surface methodology(RSM) was conducted to read the trend of desorption. Increasing density of SC-$CO_2$ raised solubility of phenolic acids.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.1
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• pp.16-23
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• 2004

Acoustic characteristics of unbaffled and baffled combustion chamber are experimentally investigated under atmospheric condition to preliminarily determine baffle for mitigation of combustion instability. To investigate the effect of the baffle which has several configurations such as radial baffles and hub/blade baffle, resonant-frequency shift and damping factors of the chamber were analyzed and compared quantitatively with those of the unbaffled combustion chamber. From a view of acoustic characteristics, radial baffles with several configurations have not much difference in resonant-frequency shift and damping factor ratio with each other. On the other hand, hub and blade baffle is very effective to suppress the first tangential mode which was found to be the most harmful acoustic mode in KSR(Korean Sounding Rocket)-III engine. But more study on design parameters such as hub size and axial length should be done for complete optimization of hub and blade baffle. The present study based on linear acoustic analysis is expected to be a useful confirming tool to predict acoustic field and design a passive control devices such as baffle and acoustic cavity.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1326-1327
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• 2008

Recently, the air pollution is supposed is to be the most serious environmental problem. Therefore, a small air cleaner is asked to make comfortable indoor environment for the moderns who have frequent indoor activity. In this study, without generating of the second pollution source, dust in the air and harmful microorganisms can be removed by the electric dust collecting technology which has high reliability and efficiency to be able to remove the impurities even though it is just 0.01${\mu}m$. Accordingly, power sources of the dust collector use, it is not inefficiency and offering to dust collector unstable. In order to overcome the point at issue, a this study, for power factor compensating use the PFC circuit, for removing the noise use EMI filter and for generating the hight voltage use the Cockcroft Walton Circuit. And we study power source on characteristic and improvement.

• The Journal of Information Systems
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• v.23 no.1
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• pp.111-138
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• 2014

As the Internet is widely used worldwide, Cyber world has become a part of daily life. On the other hand, the adverse effects of Internet, such as abusive comments, illegal harmful contents, rumor diffusion, infringement on a right have emerged with the increase. Researchers recognized the important of cyber ethics as an effective means of coping with the adverse effects on Internet. But, Little empirical research has been related to cyber ethics in management information systems. Thus, the purpose of this research is to identify multidimensional motivation factors that cyber ethics awareness and compliance behavior Intention. For this, this study investigated the factors that might influence Internet users to compliance cyber ethics. Using university students as a sample, one hundred and ninety six are collected for further analysis. The results of this study are as follows; First, self-esteem, Moral Obligation, self-control, cyber ethics education and Social Influence are significantly related to cyber ethics awareness, while punishment is not significantly related. Second, cyber ethics awareness have a positive effect on cyber ethics compliance behavior Intention. Third, the moderating effect of ego strength is also significant. This study is significant in that it established a behavior model to understand the compliance of cyber ethics with internet user in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.607-612
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• 1999

Cigarette smoking is the potential risk factor for lung cancer and chronic pulmonary disease, as well as inflammatory bowel disease and reproductive malfunction. Nicotine and tar have been im plicated as a major factor in the pathogenesis of the diseases. Nicotine increases heart rate and blood pressure due to stimulation sympathetic neurotransmission and tar also accounts for the severe damage of peridontal diseases and osteoporosis in postmenopausal women. Portulaca oleracea, which contains significant amount of K+, noradrenaline and dopamine as well as various nutrients, has been used for many medicinal purposes and one of which is the detoxification of insect or snake toxins. The purpose of this study was to investigate the action of Portulaca oleracea extracts on the reduction of harmful materials of tabacco. The reduction percentages were measured in the presence and absence of each solvent extract of Portulaca oleracea using reversed C18 column of HPLC. Nicotine reduction effects were obtained from aqueous, methanol and chloroform extracts of Portulaca oleracea as 89%, 55% and 51%, respectively. The results suggest that the polar extracts of Portulaca oleracea affects the reduction of nicotine which is responsible for many diseases.

• The Journal of Internal Korean Medicine
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• v.18 no.2
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• pp.131-150
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• 1997

As to the effects of drinking on the cerebrovascular system, the result of studies by Eastern-Western medicine indicate the following conclusions: 1. Oriental medical studies show drinking causes 'Dam-em', 'Dam-tak', and 'Seub-yul' and is, thus related to hypertension and hyperlipidemia. 2. Oriental medical studies also show that hypertension and hyperlipidemia, which includes apoplexy, a dizziness, headaches and 'Gan-yang', are caused by 'Dam-em', 'Dam-tak' and 'Heul-uh'. In most cases of obesity. which is piled 'Seub-dam' in the spleen and stomach, is caused by alcohol consumption. 3. Large amounts of alcohol consumption is a dangerous factor in many kinds of cerebrovascular attacks but under the middle grade of drinking it is not harmful. And it is a predominant theory that a small quantity of alcohol consumption is good for preventing cerebrovascular attacks. 4. Taking a brain computed tomography after alcohol has been introduced into the system reveals strange symptoms like ventricle dilatation, cerebral atrophy, and pathologic histological degeneration. 5. Alcohol is related to hypertension, hyperlipidemia, obesity which are dangerous factors in cerebrovascular attacks. This is especially true with hypertension and obesity. 6. Western medicine says, because of the close relations between hypertension, hyperlipidemia, and the grade of obesity, drinking increases the chances of cerebrovascular attacks. Our findings show that reducing alcohol intake, an environmental factor, will help prevent cerebrovascular attacks.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.433-444
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• 2021

The study seeks to identify the factors affecting the green marketing element of students' food purchasing decision at Co-opMart supermarket chain in Ho Chi Minh City through the application of a mix of qualitative and quantitative research methods that include probability sampling and convenient sampling of 400 students from Ho Chi Minh City University of Technology (HUTECH). The data are analyzed with SPSS software using Cronbach's Alpha, Exploratory Factor Analysis, Multiple Linear Regression and PATH model to test the model through the intermediate variable 'student's perception' and the hypotheses, identifying the green marketing effects on HUTECH students' food purchasing decisions at Ho Chi Minh City Co-opMart supermarket chain. The results of the study identify four factors of the green marketing mix (4Cs), namely, green commodity, green cost, green convenience, and green communication. All these factors have an influence on the student's food purchasing decision at Co-opMart supermarket. Cost is the strongest factor eliciting student's interest in purchasing green products, followed by convenience, then communication. Commodity has the least impact on green purchasing decision. This study proposes some feasible solutions for Co-opMart managers to attract more students using green food in the complex situation of contaminated food, which is extremely harmful to consumers' health.

• Particle and aerosol research
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• v.19 no.1
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• pp.1-11
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• 2023

Respiratory face masks are protective facepieces that are designed to filter inhaled air. They are easy-to-use devices that can protect the wearer against various hazardous particles in the air. Respiratory face masks also prevent the spread of viruses and bacteria-containing droplets that are released from the coughing or sneezing of the infected people. During the COVID-19 pandemic, various types of face masks have circulated on the market. Their ability to filter sub-micron particles, which are the sizes of harmful particulate matter and airborne viruses, needs to be investigated. Their breathability, the easiness of breath through the mask, also needs to be considered. In this study, wwe evaluated the performance of filters used for different types of face masks certified by different standards including Korean (KF94, KF80, KF-AD), USA (N95), and Chinese (KN95) standards. We also tested the filters of nanofiber masks and surgical masks for which there are no standards for filtration test. The N95 mask filters showed the highest quality factor for capturing virus-sized particles. The other types of mask filters have acceptable performance except for nanofiber mask filters whose performance is very low.