• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.363-368
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• 2020

This study was conducted to evaluate several physiological activities of 4 sweet persimmon cultivar leaf water extracts. One new cultivar ('Hongchu' (HC)]) and three traditional cultivars ('Sangseojosaeng' (UW), Japanese Uenishiwase; 'Seochonjosaeng' (NW), Japanese Nishimurawase; and 'Buyu' (FY), Japanese Fuyu) were used in this study. The HC extract showed significantly higher DPPH and ABTS radical scavenging activities, tyrosinase inhibitory activity, and acetaldehyde dehydrogenase activity than the other extracts, while the FY extract exhibited a relatively higher alcohol dehydrogenase activity. The HC extract contained higher amount of phenolics and ascorbic acid. These results suggest the possibility of high-quality persimmon leaf tea development using the new sweet persimmon cultivar, HC.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1539-1545
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• 2010

In beer, glutathione works as the main antioxidant compound, which also correlates with the stability of the beer flavor. In addition, high residual sugars in beer contribute to major nonvolatile components, which are reflected in a high caloric content. Therefore, in this study, the Saccharomyces cerevisiae GSH1 gene encoding glutamylcysteine synthetase and the Saccharomycopsis fibuligera ALP1 gene encoding ${\alpha}$-amylase were coexpressed in industrial brewing yeast strain Y31 targeting the ${\alpha}$-acetolactate synthase (AHAS) gene (ILV2) and alcohol dehydrogenase gene (ADH2), resulting in the new recombinant strain TY3. The glutathione content in the fermentation broth of TY3 increased to 43.83 mg/l as compared with 33.34 mg/l in the fermentation broth of Y31. The recombinant strain showed a high ${\alpha}$-amylase activity and utilized more than 46% of the starch as the sole carbon source after 5 days. European Brewery Convention tube fermentation tests comparing the fermentation broths of TY3 and Y31 showed that the flavor stability index for TY3 was 1.3-fold higher, whereas its residual sugar concentration was 76.8% lower. Owing to the interruption of the ILV2 gene and ADH2 gene, the contents of diacetyl and acetaldehyde as off-flavor compounds were reduced by 56.93% and 31.25%, respectively, when compared with the contents in the Y31 fermentation broth. In addition, since no drug-resistant genes were introduced to the new recombinant strain, it should be more suitable for use in the beer industry, owing to its better flavor stability and other beneficial characteristics.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1726-1736
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• 2013

Biosynthesis of indole-3-acetic acid (IAA) via the indole-3-pyruvic acid pathway involves three kinds of enzymes; aminotransferase encoded by aspC, indole-3-pyruvic acid decarboxylase encoded by ipdC, and indole-3-acetic acid dehydrogenase encoded by iad1. The ipdC from Enterobacter cloacae ATCC 13047, aspC from Escherichia coli, and iad1 from Ustilago maydis were cloned and expressed under the control of the tac and sod promoters in E. coli. According to SDS-PAGE and enzyme activity, IpdC and Iad1 showed good expression under the control of $P_{tac}$, whereas AspC was efficiently expressed by $P_{sod}$ originating from Corynebacterium glutamicum. The activities of IpdC, AspC, and Iad1 from the crude extracts of recombinant E. coli Top 10 were 215.6, 5.7, and 272.1 nmol/min/mg-protein, respectively. The recombinant E. coli $DH5{\alpha}$ expressing IpdC, AspC, and Iad1 produced about 1.1 g/l of IAA and 0.13 g/l of tryptophol (TOL) after 48 h of cultivation in LB medium with 2 g/l tryptophan. To improve IAA production, a tnaA gene mediating indole formation from tryptophan was deleted. As a result, E. coli IAA68 with expression of the three genes produced 1.8 g/l of IAA, which is a 1.6-fold increase compared with wild-type $DH5{\alpha}$ harboring the same plasmids. Moreover, the complete conversion of tryptophan to IAA was achieved by E. coli IAA68. Finally, E. coli IAA68 produced 3.0 g/l of IAA after 24 h cultivation in LB medium supplemented with 4 g/l of tryptophan.

• Analytical Science and Technology
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• v.13 no.2
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• pp.241-249
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• 2000

In this paper, ozonation of humic acid in water was characterized using $UV_{254}$ absorbance, TOC, Ultra Filtration and $^{13}C-NMR$. Also, carbonyl compounds in ozonated water were analyzed by GC/MS using PFBOA method. Ozonation by-products of water containing humic acid were determined as formaldehyde, acetaldehyde, acetone, glyoxal and methylglyoxal. Results of $UV_{254}$ absorbance and TOC with ozonation time at humic acid 20, 100ppm represent that decrease rate of 80% within ozonation time is 20 min and TOC removal rate of 40-50% within ozonation time is 30 min. Results for $^{13}C-NMR$ and Ultra Filtration, humic acid of high molecular weight by ozonation are oxidated and decomposed so that it was conversed low molecular weight such as aldehydes, carboxylic acid.

• Journal of Environmental Science International
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• v.26 no.1
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• pp.67-78
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• 2017

Combustion of ethanol (EtOH) at low temperatures has been studied using titania- and silica-supported platinum nanocrystallites with different sizes in a wide range of 1~25 nm, to see if EtOH can be used as a clean, alternative fuel, i.e., one that does not emit sulfur oxides, fine particulates and nitrogen oxides, and if the combustion flue gas can be used for directly heating the interior of greenhouses. The results of $H_2-N_2O$ titration on the supported Pt catalysts with no calcination indicate a metal dispersion of $0.97{\pm}0.1$, corresponding to ca. 1.2 nm, while the calcination of 0.65% $Pt/SiO_2$ at 600 and $900^{\circ}C$ gives the respective sizes of 13.7 and 24.6 nm when using X-ray diffraction technique, as expected. A comparison of EtOH combustion using $Pt/TiO_2$ and $Pt/SiO_2$ catalysts with the same metal content, dispersion and nanoparticle size discloses that the former is better at all temperatures up to $200^{\circ}C$, suggesting that some acid sites can play a role for the combustion. There is a noticeable difference in the combustion characteristics of EtOH at $80{\sim}200^{\circ}C$ between samples of 0.65% $Pt/SiO_2$ consisting of different metal particle sizes; the catalyst with larger platinum nanoparticles shows higher intrinsic activity. Besides the formation of $CO_2$, low-temperature combustion of EtOH can lead to many other pathways that generate undesired byproducts, such as formaldehyde, acetaldehyde, acetic acid, diethyl ether, and ethylene, depending strongly on the catalyst and reaction conditions. A 0.65% $Pt/SiO_2$ catalyst with a Pt crystallite size of 24.6 nm shows stable performances in EtOH combustion at $120^{\circ}C$ even for 12 h, regardless of the space velocity allowed.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.4
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• pp.610-615
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• 2010

Alcohol is the most widely psychoactive drug and has known in almost all civilization since ancient time. Recently increase consuming alcoholic beverages, alcohol is on of the major public health problems in the world. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) play important roles in the metabolism of alcohols and aldehydes. The drink consists of medicinal herbs, Puerariae Radix, Phyllostachyos Folium, Citri Pericarpium, Polygonati Rhizoma, Rehmanniae Rhizoma (Vinegar), which have been widely used in oriental medicine. This study was designed to investigate effects of medicinal herbal drink (MHD) on alcohol metabolism in drunken SD rats subjects. In experiment, rats were treated to ethanol (EtOH, 3 g/kg, PO) at 60 min. after saline (CON) or MHD (1 ml/kg, PO) administration. The blood alcohol concentration (BAC), blood acetaldehyde concentration (BALC) activities of ADH, ALDH, AST and ALT were significantly decreased in MHD group than in control group as a time-dependent manner. And drinking water volume in MHD group with duplicate treatment, were significantly decreased than in CON group. These results suggested that MHD intake could give an influence upon the reduction in BAC and BALC may alleviate acute ethanol-induced hepatotoxicity by altering alcohol metabolic enzyme activities.

• Horticultural Science & Technology
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• v.35 no.3
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• pp.300-313
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• 2017

'Unicon' cherry tomato (Solanum lycopersicum) is one of the most highly perishable horticultural crops due to its high water content and respiration rate. This study was carried out to assess the effect of continuous application of $CO_2$ (control [air], 3%, and 5%) on the quality and shelf life of cherry tomato fruits stored at $10^{\circ}C$ and $85{\pm}5%$ relative humidity (RH) at two maturity stages (pink and red). Continuous application of $CO_2$ did not affect the soluble solids content (SSC) or titratable acidity (TA) of the fruit at either maturity stage during storage. However, there was a significant difference among treatments in terms of flesh firmness, cell wall thickness, pectin content, vitamin C content, skin color, lycopene content, weight loss, ethylene production rate, respiration rate, and acetaldehyde and ethanol production. Fruits treated with 5% $CO_2$ maintained their high quality with regards to vitamin C, skin color ($a^*$), lycopene content, weight loss, physiological parameters (ethylene production rate, respiration rate, and volatile compounds), flesh firmness, cell wall thickness, and pectin content at both maturity stages compared with 3% $CO_2$ treatment and the control. Continuous application of $CO_2$ (5%) reduced the ethylene production rate and the production of volatile compounds during storage. Therefore, cherry tomato 'Unicon' fruit can be stored for two weeks without losing fruit quality at both maturity stages under continuous application of 5% $CO_2$ as a postharvest treatment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.47-54
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• 2018

Concrete undergoes various deterioration on surface. Impregnant with silicate is usually applied to concrete surface and forms insoluble hydrates, which can provide many engineering advantages. In the work, concrete impregnated with colloidal silicate is used for durability enhancement in surface and self-clearing performance is evaluated with photocatalyst-$TiO_2$ spraying. For the work, various tests are performed both for strength evaluation and durability evaluation such as absorption ratio, drying shrinkage, chloride penetration, sulfate resistance, and freezing/ thawing action. Furthermore, removal and self-clearing performance are evaluated with Acetaldehyde decomposition and Methylene blue decolorization. Through silicate impregnation and photocatalyst spraying, the impregnated concrete can have not only durability enhance but also self-clearing performance.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.E1
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• pp.19-26
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• 2006

The decomposition of gaseous $CH_3CHO$ was investigated by metal loaded $TiO_2$ (pure $TiO_2,\;Pt/TiO_2,\;Pd/TiO_2,\;Mn/TiO_2\;and\;Ag/TiO_2$) with $UV/TiO_2$ process and $UV/TiO_2/O_3$ process at room temperature and atmospheric pressure. Metal loaded $TiO_2$ was prepared by photodeposition. Decomposition of $CH_3CHO$ was carried out in a flow-type photochemical reaction system using three 10W black light lamps ($300{\sim}400nm$) as a light source. The experimental results showed that the degradation rate of $CH_3CHO$ was increased with Pt and Ag on $TiO_2$ compared to pure $TiO_2$, but decreased with depositing Pd and Mn on pure $TiO_2$. The considerable increase in the degradation efficiency of the $CH_3CHO$ was found by a combination of photocatalysis and ozonation as compared to only by ozonation or photocatalysis. Loading of Pt on $TiO_2$ promoted conversion of gaseous ozone. The degradation rate of gaseous $CH_3CHO$ decreased with an increase of water vapor in the feed stream for the both $UV/TiO_2\;and\;UV/TiO_2/O_3$ processes. The pure $TiO_2$ was more affected by the water vapor than Pt loaded $TiO_2$.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.6
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• pp.876-887
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• 2006

Recently, there have been a large number of remodeling (or renovation) works in old buildings in urban areas. Compared to new buildings, environmental risk might be more significant in such buildings where remodeling works are going on, since some parts of the building may still be in service for people. This study was carried out to investigate the impacts of remodeling works on the indoor air quality (IAQ) of a large building (a 22 stories university library). Indoor air monitoring was conducted during and after the remodeling works every two weeks for a one year period, and target compounds included BTEX, styrene, TVOC, carbonyl compounds such as formaldehyde and acetaldehyde. $CO,\;CO_2,\;PM_{10}$, and $PM_{2.5}$. Overall, the IAQ appeared to be recovered within two months after the remodeling works. However, in some places, concentrations of formaldehyde, toluene, xylene. and ethylbenzene showed higher levels even after works than those during the works. The results indicate that painting, glues and office furnitures are major sources of aromatic VOCs and formaldehyde. Therefore, in order to decrease the concentrations of toxic VOCs, the use of environmental-friendly building materials is strongly recommended during the remodeling works. In addition, IAQ control and management scheme (for example, baking the inside of the building) should be taken into consideration before reopening the buildings.