• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2487-2493
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• 2014

Dimeric ${\beta}$-cyclodextrin linked by a thioether bridge was synthesized from a reaction of mono-6-iodo-6-deoxy-${\beta}$-cyclodextrin with sodium sulfide, and the structure was analyzed using nuclear magnetic resonance spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The effects of thioether-bridged dimeric ${\beta}$-CD on the aqueous solubility of flavonols (myricetin, quercetin, and kaempferol) were investigated by ultraviolet-visible spectroscopy. The aqueous solubility of myricetin, quercetin, and kaempferol were enhanced 33.6-, 12.4-, and 10.5-fold following the addition of 9 mM of thioether-bridged dimeric ${\beta}$-CD. In comparison, the aqueous solubility of myricetin, quercetin, and kaempferol were enhanced 5.4-, 3.3-, and 2.7-fold using the same concentration of monomeric ${\beta}$-cyclodextrin. Furthermore, the formation of flavonol/thioether-bridged dimeric ${\beta}$-CD inclusion complexes was confirmed with nuclear magnetic resonance, Fourier-transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The results showed that the nature of the complexes significantly differed from that of free flavonols. Herein, we suggest that the thioether-bridged dimeric ${\beta}$-CD can act as an effective complexing agent for flavonols.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.14-23
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• 2015

Alzheimer's disease is one of the most common types of degenerative dementia. As a considerable cause of Alzheimer's disease, neurotoxic plaques composed of 39 to 42 residue-long amyloid beta($A{\beta}$) fibrils have been found in the patient's brain in large quantity. A previous study found that erythrosine B (ER), a red color food dye approved by FDA, inhibits the formation of amyloid beta fibril structures. Here, in an attempt to elucidate the inhibition mechanism, we performed molecular dynamics simulations to demonstrate the conformational change of $A{\beta}40$ induced by 2 ERs in atomistic detail. During the simulation, the ERs bound to the surfaces of both N-terminus and C-terminus regions of $A{\beta}40$ rapidly. The observed stacking of the ERs and the aromatic side chains near the N-terminus region suggests a possible inhibition mechanism in which disturbing the inter-chain stacking of PHEs destabilizes beta-sheet enriched in amyloid beta fibrils. The bound ERs block water molecules and thereby help stabilizing alpha helical structure at the main chain of C-terminus and interrupt the formation of the salt-bridge ASP23-LYS28 at the same time. Our findings can help better understanding of the current and upcoming treatment studies for Alzheimer's disease by suggesting inhibition mechanism of ER on the conformational transition of $A{\beta}40$ at the molecular level.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.1
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• pp.94-102
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• 2003

This paper describes the load parallel type full-bridge high frequency resonant inverter can be used as power source. Output control method of proposed circuit is compared with pulse frequency modulation(PFM), pulse width modulation(PWM) and pulse phase variation(Phase-Shift). The analysis of the proposed circuit is generally described by using the normalized parameters. The principle of basic operating and the its characteristics are estimated according to the parameters such as switching frequency(${\mu}$), pulse width($\theta$d) the variation of phase angle($\phi$) by three driving signal patterns. Experimental results are presented to verify the theoretical analysis result. In future, Characteristics by three driving signal control method is provided as useful data in case of output control of a power supply in various fields as induction heating application, DC-DC converter etc.

• Journal of Korean Society of Rural Planning
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• v.29 no.4
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• pp.69-79
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• 2023

This study investigated changes in the spatial structure of rural villages in Sayang Village, where accessibility restrictions to island areas were improved, and analyzed the spatial composition of houses according to changes in the living environment. First, despite the island's vulnerable transportation requirements being resolved by the completion of the land and bridge in 2018, the local economy continues to stagnate due to a vicious cycle of local living services and job losses. Second, when a survey of residents' changed living services was conducted through the continuation of the specification map, the scope of living areas was expanded by analyzing the frequency and place of visit of fresh food purchases, use of convenience facilities, and medical visits. Third, it is judged that the naturally formed village is composed of small roads to the inside of the village due to the disorganized street system and the form of walking instead of vehicles. Finally, as a result of analyzing the residential space of houses in fishing villages, the aging rate of houses over 30 years old was 62 (91.2%), and the average area of the first house space built was 65.2m² to 14.1m², an increase of 17.8% of the total area.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.368-373
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• 2015

Faecal analysis was carried out to identify the diet composition of Eptesicus serotinus after collecting the faeces from 25 female bats. Five bats were captured at a bridge where a colony of E. serotinous was found in Andong city, Gyeongbuk, every month from May to September 2014. A total of 100 faeces were collected and the parts of insects obtained from the faeces were examined using a high-resolution microscope (50 ${\times}$ binocular microscope) and then the orders of the insects were identified by the characteristics of the parts of the insect (mouthpart, leg, wing, antenna, elytra, etc.). According to the results of the faecal analysis, 4 orders: Coleoptera, Hymenoptera, Diptera and Hemiptera were used as food resource of E. serotinus. Coleoptera was found in May, July, August, and September. Interestingly, only Coleoptera were found in May and July. Hemiptera, Diptera, and Hymenoptera were found to be used as food resources in September, June, and August.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.11-11
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• 2014

Fungal pathogens have huge impact on health and economic wellbeing of human by causing life-threatening mycoses in immune-compromised patients or by destroying crop plants. A key determinant of fungal pathogenesis is their ability to undergo developmental change in response to host or environmental factors. Genetic pathways that regulate such morphological transitions and adaptation are therefore extensively studied during the last few decades. Given that epigenetic as well as genetic components play pivotal roles in development of plants and mammals, contribution of microbial epigenetic counterparts to this morphogenetic process is intriguing yet nearly unappreciated question to date. To bridge this gap in our knowledge, we set out to investigate histone modifications among epigenetic mechanisms that possibly regulate fungal adaptation and processes involved in pathogenesis of a model plant pathogenic fungus, Magnaporthe oryzae. M. oryzae is a causal agent of rice blast disease, which destroys 10 to 30% of the rice crop annually. Since the rice is the staple food for more than half of human population, the disease is a major threat to global food security. In addition to the socioeconomic impact of the disease it causes, the fungus is genetically tractable and can undergo well-defined morphological transitions including asexual spore production and appressorium (a specialized infection structure) formation in vitro, making it a model to study fungal development and pathogenicity. For functional and comparative analysis of histone modifications, a web-based database (dbHiMo) was constructed to archive and analyze histone modifying enzymes from eukaryotic species whose genome sequences are available. Histone modifying enzymes were identified applying a search pipeline built upon profile hidden Markov model (HMM) to proteomes. The database incorporates 22,169 histone-modifying enzymes identified from 342 species including 214 fungal, 33 plants, and 77 metazoan species. The dbHiMo provides users with web-based personalized data browsing and analysis tools, supporting comparative and evolutionary genomics. Based on the database entries, functional analysis of genes encoding histone acetyltransferases and histone demethylases is under way. Here I provide examples of such analyses that show how histone acetylation and methylation is implicated in regulating important aspects of fungal pathogenesis. Current analysis of histone modifying enzymes will be followed by ChIP-Seq and RNA-seq experiments to pinpoint the genes that are controlled by particular histone modifications. We anticipate that our work will provide not only the significant advances in our understanding of epigenetic mechanisms operating in microbial eukaryotes but also basis to expand our perspective on regulation of development in fungal pathogens.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.516-520
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• 2002

This study was designed to investigate the hepatoprotective effects of Semisulcospira libertina and garlic on the acute hepatotoxicity induced by carbon tetrachloride (CCl$_4$) of rats. Male Sprague-Dawley rats weighing 200∼220g were pretreated with dehydrated powder of Semisulcospira libertina (2.1 g/kg, po; SL) and dehydrated powder mixture of Semisulcospira libertina and garlic (3g/kg, 7:3 ratio, po; SG) once daily for 3 consecutive days, and then given a single dose of CCl$_4$(1g/kg in 5ml/kg corn oil, po) and liver function was determined 24 hrs later. Liver damage was assessed by quantitating activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH) and alkaline phosphatase (ALP) as well as by histopathological examination. Pretreatments with SL and SG significantly decleased CCl$_4$-elevated ALT (48% and 61% respectively), AST (32% and 47%) and SDH (51% and 76%), but had no effect on ALP. SL and SG had revealed hepatoprotective effects against CCl$_4$-induced histopathological changes such as severe necrosis, inflammatory cell infiltration and congestion in the central gene of hepatic lobule. These findings demonstrate that SL and SG may haute the hepatoprotective effect on CCl$_4$-induced liver damage.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.105-108
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• 1993

A new devised conductivity meter was used in the rapid and convenient determination of salt contents of soysauce and margarine. The equation $(1){\sim}(5)$ was set up between the electric conductivity (x) for 100 times diluted solution of soysauce and the salt contents (y). y=0.083x-1.253 $(at\;15^{\circ}C)$ (1) y=0.077x-2.062 $(at\;20^{\circ}C)$ (2) y=0.071x-2.686 $(at\;25^{\circ}C)$ (3) y=0.066x-3.153 $(at\;30^{\circ}C)$ (4) y=0.062x-3.522 $(at\;35^{\circ}C)$ (5) y=(-0.001139t+0.0999)x+(-0.126t+0.557) $(temperature\;range;\;15{\sim}35^{\circ}C)$ (6) y=salt contents [%], x=conductivity $[{\mu}{\Omega}^{-1}{\cdot}cm^{-1}]$, $t=temp.\;[^{\circ}C]$. The salt contents could be estimated by the equation $(1){\sim}(6)$ and the measured conductivity. The estimated salt contents agreed with that determined by conventional method within 0.27[%] as salt contents. For margarine, the equation (7) was setup between the conductivity (x) and the salt contents (y) y=0.00266x+0.057 $(at\;20^{\circ}C)$ (7) y=salt contents [%], x=conductivity $[{\mu}{\Omega}^{-1}{\cdot}cm^{-1}]$ The salt contents estimated with the equation (7) and the measured condutivity agreed with that determined by conventional method within 0.028[%] as salt contents. The electric conductivity obtained with conductivity meter could be a valuable criteria salt contents test of Korean soysauce and margarine determining in a few second or minute by handy compact portable meter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.185-196
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• 1991

The rice culture, the most representative farming in humid regions of East Asia, have been playing a decisive role in supplying finance and staple food of the nations. This situation must be formed with exchange of techniques and interests in the matter betwen China, Korea and Japan. Especially Korea was obligated to playa bridge role because of geographical conditions, thereby the situations of agriculture were repeatedly reclaimed, and recovered by changes of cultures during external aggression, and internal disturbances. Thus, it is obvious that development of rice culture and its techniques was being undaunted in Korea. Nevertheless, in history of Korea, the documents of the government on chronicles of the dynasty were plentiful, while they were very poor in countryside and rural communities, so that it is very hard to search the transition process of rice culture and its techniques. Finally, the faming books that were begun editing from the early Chosun dynasty are here divided chronically and examined, and also the interrelationships are compared and discussed here. The objectives of this study were to discuss the following questions？ How were the dryfarming techniques, introduced from the ancient China by the end of Koryo dynasty, established to fit for our situations？ What were the basis for reestablishment of the techniques with originality？ How were they continued and changed through the internal and external wars in the Chosun dynasty？ What were suggested from these continuously results by the end of the Chosun dynasty?

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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• pp.51-58
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• 2006

The purpose of this research presents a method to position and makes the structure for eco-corridors reasonably with collectable analysing results of various effects shown in mammals' road-kill at 429 points. Target animals of this research are Leopard cat, Siberian weasel, Raccoon dog, Korean hare, Eurasian red squirrel, Siberian chipmunk and Water deer. The results derived from the empirical analysis on the contents above are followed. First, according to the results as for Leopard cat road kill analysis, which is designated as Endangered Species Class II, the eco-corridor might be located at near village having stead food in order to decrease the frequencies of road-kill, because its road kill points were mainly collected at 4 lane hilly road with mountain-road-farm area geological type of. Second, because Siberian weasel's road kill was detected at 2 lane hilly road with mountain-road-stream geological type, the eco-corridor might be located at near a mill to decrease road-kill frequencies. Third, the road-kill frequency of Eurasian red squirrel can be reduced when the eco-corridor is located at the area across coniferous tree near 4 lane west sea freeway with mountain-road-mountain. Fourth, the road-kill of Raccoon dog can be reduced when the eco-corridor is located at 4 lane mountain road or hilly road with the geological type having farm land-road-mountain(stream). Fifth, Korean hare's road-kill can be reduced when the eco-corridor is located at grass land across ridge line of mountain, because wild rabbit road kill was happened at 4 lane mountain road or 2 lane mountain road(mountain-road-mountain). Sixth, As for Siberian chipmunk, the eco-corridor might be located at the side slope of mountain road at 2 lane mountain road under the speed of 60km/h with mountain-road-mountain. Seventh, For Water deer, the eco-corridor might be located at 4 lane hilly road with mountain-road-farm land. As for Common otter, Amur hedgehog, Yellow-throated marten, Weasel, it is difficult to specify the proper site of eco-corridor due to the lack of data. Eco-corridors for carnivores might be well located at 4 lane hilly road or 2 lane hilly road with mountain-road-farm land, and the track for herbivores might be well located as a overhead bridge on mountain-road-mountain type across mountains. In order to position eco-corridors for wildlife properly, we have to research animal's behavior with ecological background, and to consider the local uniqueness and regularly collect the empirical road-kill data in long term 3 to 5 year, which can be the foundation for the more suitable place of wild life eco-corridors.