• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.383-383
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• 2010

Gas-phase hydrogen atoms create a variety of chemical and physical phenomena on Si surfaces: adsorption, abstraction of pre-adsorbed H, Si etching, Si amorphization, and penetration into the bulk lattice. Thermal desorption/evolution analyses exhibited three distinct peaks, including one from the crystalline bulk. It was previously found that thermal-energy gaseous H(g) atoms penetrate into the Si(100) crystalline bulk within a narrow substrate temperature window(centered at ~460K) and remain trapped in the bulk lattice before evolving out at a temperature as high as ~900K. Developing and sustaining atomic-scale surface roughness, by H-induced silicon etching, is a prerequisite for H absorption and determines the $T_s$ windows. Issues on the H(g) absorption to be further clarified are: (1) the role of the detailed atomic surface structure, together with other experimental conditions, (2) the particular physical lattice sites occupied by, and (3) the chemical nature of, absorbed H(g) atoms. This work has investigated and compared the thermal H(g) atom absorptivity of Si(100), Si(111) and Si(110) samples in detail by using the temperature programmed desorption mass spectrometry (TPD-MS). Due to the differences in the atomic structures of, and in the facility of creating atom-scale etch pits on, Si(100), (100) and (110) surfaces, the H-absorption efficiency was found to be larger in the order of Si(100) > Si(111) > Si(110) with a relative ratio of 1 : 0.22 : 0.045. This intriguing result was interpreted in terms of the atomic-scale surface roughening and kinetic competition among H(g) adsorption, H(a)-by-H(g) abstraction, $SiH_3(a)$-by-H(g) etching, and H(g) penetraion into the crystalline silicon bulk.

• 한국전기화학회:학술대회논문집
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• 2003.07a
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• pp.13-19
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• 2003

• Journal of the East Asian Society of Dietary Life
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• v.9 no.4
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• pp.442-451
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• 1999

This study was conducted to investigate the antimicrobial activity of Prunus mume extracts. Prunus mume extracts have growth inhibitory activity to various microorganisms. Gram positive bacteria such as Bacillus cereus, Bacillus subtilis, Micrococcus leteus, Staphylococcus epidrimidis were more easily inhibited than Gram negative bacteria tested Vibrio parahaemolyticus, Salmonella typhimurium, Escherichia coli, Proteus vulgaris and Yeasts by Prunus mume extracts. Among several fractions of methanol extract, EtOAc & BuOH fractions were showed strong antibacterial activities, but those fractions were not showed on fungi.

• Proceedings of the Culinary Society of Korean Academy Conference
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• 2001.08a
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• pp.29-41
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• 2001

This study was conducted to investigate the antimicrobial activity of Prunus mume extracts. Prunus mume extracts have growth inhibitory activity to various microorganisms. Gram positive bacteria such as Bacillus cereus, Bacillus subtilis, Micrococcus leteus, Staphylococcus epidrimidis were more easily inhibited than Gram negative bacteria tested Vibrio parahaemolyticus, Salmonella typhimurium, Escherichia coli, Proteus vulgaris and Yeasts by Prunus mume extracts. Among several fractions of methanol extract, EtOAc & BuOH fractions were showed strong antibacterial activities, but those fractions were not showed on fungi.

• Journal of Mushroom
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• v.17 no.1
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• pp.24-33
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• 2019

The physicochemical characteristics of oyster mushrooms (Pleurotus ostreatus) cultivated using liquid spawn (MLS) were compared with those of commercial mushrooms cultivated using solid spawn. The color intensity of the two types of mushrooms showed no remarkable difference. The hardness of the MLS-cultivated mushrooms was significantly higher, but their moisture content (86.80%) was significantly lower than that of the commercial mushrooms. Mineral contents in MLS-cultivated mushrooms (421.17 mg/100 g) were significantly higher than those in the commercial mushrooms (333.26-362.78 mg/100 g); in particular, the potassium (K) content was the most abundant in the former. The amino acid content in the MLS-cultivated mushrooms (4,695.22 mg/100 g) was about 1.4-2.0 times that in the commercial mushrooms. The essential amino acid contents and sum of aspartic acid and glutamic acid were higher in the MLS-cultivated mushrooms than in the commercial mushrooms. The ${\beta}-glucan$ content in the MLS-cultivated mushrooms was 1.1-2.3 times higher than that in the commercial mushrooms. The total phenol and flavonoid contents and the DPPH and ABTS radical-scavenging activities of the MLS-cultivated mushrooms were significantly higher than those of the commercial mushrooms; however, the reducing power showed an opposite trend. Therefore, MLS-cultivated mushrooms contained higher amounts of valuable components and higher antioxidant activities than commercial mushrooms.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.867-872
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• 2002

This study was performed to investigate the optimum process conditions for manufacturing yeast extract from waste brewer's yeast using various enzymes. Contents of IMP, GMP, free amino acids, and crude protein of yeast extracts were measured by enzymes treatment. Crude protein contents of yeast extracts subjected to cell wall digestion enzyme treatment were 21.1, 33.6, and 28.0% for the control grouup, glucanase (0.5%, 12 h), and tunicase (1%, 18 h), respectively. Crude protein contents of yeast extracts subjected to protease treatment were 22.0, 30.8, and 29.8% for control group, bromelin (1%, 3 h), and protamex (1%, 3 h), respectively. Crude protein content of yeast extract subjected to glucanase and protamex mixed treatment was 34.4%. The total contents of IMP and GMP of yeast extracts subjected to G+P+A (glucanase+phosphodiesterase+adenyldeminase) and G+Pro+P+A (glucanase+protamex+phosphodiesterase+adenyldeaminase) treatments were 1,066 and 1,047 mg/100 g, respectively. The content of free amino acids of yeast extract was the highest (2,302 mg/100 g) in G+Pro+P+A treatment. Optimum concentration and process condition of enzyme treatment to obtain yeast extract with high IMP, GMP, and free amino acid content were in the order of glucanase (0.5%, 12 h), protamex (1%, 3h), phosphodiesterase (0.1%, 3 h) and adenyldeaminase (1%, 1.5 h) treatments.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.420-424
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• 2002

The purpose of this study is to investigate anticariotic activity of the ethyl acetate soluble extract of Sophora flavescens Ait. for the prevention of dental caries and glucosyltransferase activity caused by Streptococcus mutans. The fraction 5-4-3 showed strong growth inhibition activity against Streptococcus mutans (MIC, 3.13 $\mu\textrm{g}$/ml). The glucosyltransferase activity of the active fraction 5-4-3 inhibited the formation of glucan and showed 77% of the antiproliferative effect at 100 $\mu\textrm{g}$/ml (P<0.05). Two flavanones, (2S)-2'-methoxy kurarinone (1) and (+)-kurarinone (2), were isolated from the active fraction 5-4-3 of the ethyl acetate soluble extract of S. flavescens Ait. Their structures were elucidated using spectroscopic methods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.486-492
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• 2011

This study was designed to evaluate the effect of hot water extract (ESW) and 70% ethanol extract (ESE) from Euphorbia supina Rafin on LPS-stimulated inflammatory response in RAW 264.7 macrophages. Upon investigation at concentrations up to $1000\;{\mu}g$/mL, ESW and ESE did not have any cytotoxic effects on RAW 264.7 macrophages. ESW induced inhibition of 21.6%~54.8% of nitric oxide (NO) production at 100~1000${\mu}g$/mL, and $PGE_2$ production was inhibited up to 25.7%~38.2% at 250~1000${\mu}g$/mL, proportional to the ESW concentrations. ESW induced inhibition of 66.1% and 54.3% of IL-6 production at 250 and $1000\;{\mu}g$/mL, respectively. ESE (100~1000${\mu}g$/mL) induced inhibition of 38.3%~77.5% of NO, 40%~94.7% of $PGE_2$, and 43.9%~89.4% of IL-6 production, proportional to the ESE concentrations. Only 44.1% of IL-10 production was inhibited at a concentration of $500\;{\mu}g$/mL. ESE induced an increase in TNF-${\alpha}$ production at a concentration of 100 and $250\;{\mu}g$/mL, whereas at high concentrations (500 and $1000\;{\mu}g$/mL), ESE induced inhibition of 19.2% and 92.4% of TNF-${\alpha}$ production, respectively. In conclusion, concentrations of more than $500\;{\mu}g$/mL ESE demonstrated effective immune-modulating activity through inhibition of NO, $PGE_2$, IL-6, IL-10, or TNF-${\alpha}$ production, as it relates to the macrophage's immuno-activity; therefore, ESE has potential as a good candidate substance for reduction of inflammatory responses.

• Bulletin of the Korean Space Science Society
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• 2007.10a
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• pp.100.1-100.1
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• 2007

• Journal of Life Science
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• v.18 no.10
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• pp.1369-1376
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• 2008

In this study, the effects of feeding citrus byproducts on nutritional components of Korean native chickens were investigated. Two samples of Korean native chickens were used for this study: T0 (chickens fed with only feed for laying hen until they became 39 weeks old, not with citrus byproducts) and T1 (chickens fed with citrus byproducts). The feed for T1 was the same as T0 for the first 16 weeks, and then was made by adding 4% of citrus byproducts to the feed for T0 between $17{\sim}39$ weeks. The chicken used for the experiment was obtained by chilling them for 2 days after slaughter. There was no significant difference between T0 and T1 regardless of feeding citrus byproducts, in terms of their breast/thigh's calorie, contents of moisture, protein, fat and ash, total structural amino acid, total free amino acid and composition of saturated/unsaturated fatty acids. The breast's cholesterol amount of T0 and T1 were 48.4 mg/100 g and 47.6 mg/100 g, respectively, while that of thigh for T0 and T1 were 75.7 mg/100 g and 72.8 mg/100 g, respectively, which implies that T1 showed lower amount of cholesterol than T0. T1 showed significantly higher amount of phosphorus, potassium, magnesium and vitamin B2 for thigh than T0 (p<0.05).