• Food Science and Biotechnology
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• v.18 no.3
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• pp.667-671
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• 2009

Extract of water-soluble polysaccharide (CFWx), showing inhibiting activity on ${\alpha}-glucosidase$, was prepared from the fruiting bodies of Cordyceps militaris by hot-water extraction, and ethanol precipitation. Chemical characteristics of CFWx were as follows: carbohydrate content 30% including 16% of uronic acid; 51% protein content; monosaccharide composition, Man:Glu:Gal (30:43:27); molecular weight $3-5{\times}10^4$. CFWx was further purified by ion-exchange, gel-permeation, and affinity chromatography and $CFWx-AH-{\alpha}$ fraction was isolated. Fundamental structure of $CFWx-AH-{\alpha}$ was deduced as ${\alpha}-(1{\to}4$)-D-glucan with ${\alpha}-(1{\to}3$)- and/or ${\alpha}-(1{\to}6$)-D-glycosidic side chains based on methylation analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.370-373
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• 2001

Temperature-dependent current-voltage characteristics of Organic Light-Emitting Diodes (OLEDs) were studied. The OLEDs were based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) as a hole transport and trois(8-hydroxyquinoline) aluminum(Alq$_3$) as an electron transport and emissive material. The current-voltage characteristics were measured in the temperature range of 10[K] and 300[K]. A conduction mechanism in OLEDs was interpreted in terms of tunneling and trap-filled limited current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.507-508
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• 2007

Temperature-dependent current-voltage characteristics of Organic Light-Emitting Diodes(OLEDs) were studied. The OLEDs were based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) as a hole transport and tris(8-hydroxyquinoline) aluminum($Alq_3$) as an electron transport and emissive material. The current-voltage characteristics were measured in the temperature range of 10[K] and 300[K]. A conduction mechanism in OLEDs was interpreted in terms of tunneling and trap-filled limited current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.533-534
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• 2005

Temperature-dependent current-voltage characteristics of organic light-emitting diodes(OLEDs) were studied in a device structure of ITO/TPD/$Alq_3$/Al. The OLEDs were based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-l,1'-diphenyl-4,4'-diamine(TPD) as a hole transport and tris(8-hydroxyquinoline) aluminum($Alq_3$) as an electron transport and emissive material. The current-voltage characteristics were measured in the temperature range of 10K and 300K. We analyzed an electrical conduction mechanism of the OLEDs using space-charge-limited current(SCLC) and Fowler-Nordheim tunneling.

• Research in Plant Disease
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• v.27 no.3
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• pp.107-114
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• 2021

During a disease survey on weeds and minor cultivated crops in Korea, a brown leaf spot disease was observed on Sonchus asper. Leaf lesions were round or irregular in shape, and grayish brown to brown with a purple margin. In severe infection, lesions enlarged and coalesced, resulting in blighting of the leaves. The isolates from these leaf lesions were identified as Alternaira sonchi based on morphological characteristics and phylogenetic analyses of Internal transcribed spacer region, Alternaria allergen a1, glyceraldehyde 3-phosphate dehydrogenase, RNA polymerase II, and translation elongation factor genes. This study provides a comprehensive description of the morphological characteristics and phylogenetical traits of A. sonchi causing brown leaf spot on S. asper in Korea.

• Mycobiology
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• v.51 no.4
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• pp.210-215
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• 2023

The aim of this study was to characterize a new fungal species, Acremonium conglutinatum, isolated from air samples collected in Wando, South Korea. Phylogenetic analysis based on the internal transcribed spacer and large subunit regions revealed its unique position within the genus Acremonium. The isolated strain displayed distinct morphological characteristics, including ellipsoid or bent-ellipsoid conidia formed in clusters on the phialides. These features differentiate the new species from closely related species within the genus. This study describes the morphological and molecular characteristics of A. conglutinatum and emphasizes its phylogenetic relationships with other Acremonium spp. The identification of this novel species contributes to our understanding of the diversity and ecological role of Acremonium.

• Computers and Concrete
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• v.33 no.3
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• pp.325-340
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• 2024

The growing demands for sustainable and high-performance construction materials necessitate a deep understanding of their physicochemical properties by that of these heterogeneities. This paper presents a comprehensive review of the state-of-the-art hierarchical multiscale modeling approach aimed at predicting the intricate physicochemical characteristics of construction materials. Emphasizing the heterogeneity inherent in these materials, the review briefly introduces single-scale analyses, including the ab initio method, molecular dynamics, and micromechanics, through a scale-bridging technique. Herein, the limitations of these models are also overviewed by that of effectively scale-bridging methods of length or time scales. The hierarchical multiscale model demonstrates these physicochemical properties considering chemical reactions, material defects from nano to macro scale, microscopic properties, and their influence on macroscopic events. Thereby, hierarchical multiscale modeling can facilitate the efficient design and development of next-generation construction.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.223-227
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• 2014

This study was investigated to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) isolated from raw milk samples and to further study on the molecular characteristics of the MRSA isolates. Using Staphylococcus Medium 110, Staphylococcus spp. were isolated from raw milk samples and further identification was carried by Vitek2 system. Minimum inhibitory concentrations (MICs) of antibiotics were conducted by serial dilution method according to the Clinical Laboratory Standards Institute (CLSI) guideline. For the detection of resistance genes and molecular characterization, PCR reaction was performed by gene specific primers and followed by DNA sequencing. Of the 698 milk samples, 94 Staphylococcus aureus (S. aureus) were identified (94 S. aureus/286 Staphylococcus spp.). Of the 94 S. aureus, seven isolates have mecA, a methicillin resistant gene. mecA positive seven isolates were then characterized by staphylococcal cassette chromosome mec (SCCmec) typing, and Panton-Valentine Leukocidin (pvl) gene using PCR. All of mecA positive isolates were resistant to ampicillin and oxacillin, but sensitive to teicoplanin, vancomycin and ciprofloxacin. One of seven isolates was SCCmec type II and six isolates were type IV and all seven isolates were pvl gene negative.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.540-546
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• 1999

The purpose of this study was to investigate the antimicrobial effects and characteristics of protamine extracted from spermary of tuna. The result of amino acids analysis showed that the contents of arginine were 46%. It was 10% lower when compared to standard protamine (SP: Asama kasei LTD, Japan). Also, there were significant difference in the contents of proline adn glycine. The average molecular weights of main protein in TP were 13,400 Da, whereas those in SP were 11,300 Da and 2,600 Da. To increase antimicrobial activities of TP, pepsin or trypsin was treated at $37^{\circ}C$. After TP was hydrolyzed with pepsin (pepsin hydrolyzed protamine: PHP) for 4hrs, the average molecular weights of the main protein were 11,300 Da and 3,900 Da, and the antimicrobial activities were significantly increased compared to TP. After TP was hydrolyzed with trypsin (trypsin hydrolyzed protamine: THP) for more than 10 min, the average molecular weights of the main protein were below 2,500 Da. PHP had higher antimicrobial effects on some gram positive bacteria (Staphylococcus aureus, Lactobacillus helveticus, Lactobacillus plantarum) than SP. However, THP had no antimicrobial activities. When TP was hydrolyzed with pepsin (PHP), its antimicrobial activities increased in the same level with those of SP, and this increase might be resulted rather from the changes of molecular weights of the main protein than from the contents of arginine in protamine.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.269-276
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• 2015

This study investigated the influence of characteristics of natural organic matter (NOM) on the formation of disinfection by-products (DBPs), and proposed the control strategies of DBPs formation in a drinking water treatment plant using lake water in Gyeongsangbuk-do. The fluorescence excitation-emission matrix analysis results revealed that the origins of NOM in raw waters to the plant were a mixture of terrestrial and microbial sources. Molecular size distributions and removals of NOM fractions were evaluated with a liquid chromatography-organic carbon detector (LC-OCD) analysis. Humic substances and low molecular weight organics were dominant fractions of NOM in the raw water. High molecular weight organics were relatively easier to remove through coagulation/precipitation than low molecular weight organics. The concentrations of DBPs formed by pre-chlorination increased through the treatment processes in regular sequence due to longer reaction time. Chloroform (74%) accounts for the largest part of trihalomethanes, followed by bromodichloromethane (22%) and dibromochloromethane (4%). Dichloroacetic acid (50%) and trichloroacetic acid (48%) were dominant species of haloacetic acids, and brominated species such as dibromoacetic acid (2%) were minimal or none. Dichloroacetonitrile (60%) accounts for the largest part of haloacetonitriles, followed by bromochloroacetonitrile (30%) and dibromoacetonitrile (10%). The formation of DBPs were reduced by 16~44% as dosages of pre-chlorine decreased. Dosages of pre-chlorine was more contributing to DBPs formation than variations of dissolved organic contents or water temperature.