• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.105-108
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• 2011

The increased concern for the security of the oil supply and the negative impact of fossil fuels on the environment, particularly greenhouse gas emissions, has put pressure on society to find renewable fuel alternatives. Compared to the traditional biofuel, ethanol, higher alcohols offer advantage as gasoline substitutes because of their higher energy density and lower hygroscopicity. For this reason, microbial fermentation is known as potential producers for sustainable energy carriers. In this study, bacterial responses including cellular and molecular toxicity were studied in three different microorganisms, such as Escherichia coli, Clostridium acetobutylicum, and Saccharomyces cerevisiae. In this study, it was analyzed specific stress responses caused by ethanol and buthanol using four different stress responsive genes, i.e. fabA, grpE, katG and recA. The expression levels of these genes were quantified by semi-quantitative reverse transcription-PCR. It was found that four genes have shown different responsive patterns when E. coli cultures were under stressful conditions caused by ethanol and buthanol, respectively. Therefore, in this study, the stress responsive effects caused by these alcohols and the extent of each stress response can be analyzed using the expression levels and patterns of different stress responsive genes.

• Textile Coloration and Finishing
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• v.33 no.3
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• pp.161-167
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• 2021

Polymer nanocomposite is considered a great alternative to solve the limitations that exist in a simple combination material, as well as to produce multifunctional and high-performance results. In this research, PVA/bentonite nanocomposite films were prepared based on the presence or absence of modification of nano-clay(bentonite) a SUPERGEL^® product, modification conditions and content, and the structural variation of the prepared PVA/bentonite nanocomposite films were examined. The effect of variations in the internal structure of the nanocomposite on mechanical and thermal properties was investigated. As a result of evaluating the thermal characteristics of the PVA/bentonite nanocomposite film based on the concentration of the modified bentonite, it was verified that the thermal characteristics and stability were improved because of interaction between the polymer and the modified nano-clay.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.531-542
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• 2012

The thesis covers the trend of research on bio-based polyurethane which is made from polyols derived mainly from plant oils and isocyanates. Castor oil is a triglyceride of ricinoleic acid containing hydroxyl group. Hydroxylation is done on the unsaturated bonds of the oils by the reactions of epoxidation/ring opening, hydroformylation/hydrogenation, ozonolysis/hydrogenation, and thiol-ene reaction. Polyols from hyperbranch, primary alcohol, polysaccharide have been studied to control the reactivity of the polyol and morphology of the microdomains. Besides, researches cover biodegradable polylactic acid polyol for medical use, fatty acid dimer polyol for the prevention of hydrolysis, and polyol with ionic group for water-borne polyurethane. Bio-based polyurethanes are being used in flexible and rigid foams, coatings, sealants, and elastomers.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.104-110
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• 2021

In this study, vinegar was prepared using black raspberry pomace to increase its utilization capacity. As a result of alcohol fermentation, the final alcohol content was 8.90% and the sugar content was 7.03°Brix. The total acid content after acetic acid fermentation was 4.44%, which was 0.38% higher than that of the juice. Among the organic acid content, the acetic acid content was higher in the pomace than in the juice. The total polyphenol (51.58 TAE mg/mL), total flavonoid (9.55 RUE mg/mL), and total anthocyanin (6.05 CYE mg/mL) contents of vinegar produced using black raspberry residue were higher than those of the juice. In addition, 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferric reducing antioxidant power (FRAP) activity were higher than those of the juice, indicating strong antioxidant properties. Thus, black raspberry pomace has excellent acetic acid fermentation ability and high antioxidant activity, indicating that it can be used as a functional fermented vinegar.

• Journal of Life Science
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• v.33 no.2
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• pp.183-190
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• 2023

Red yeast rice, also known as Hong Qu and red Koji, has been used for a long time in Asian functional food and traditional medicine. It consists of multiple bioactive substances, which can potentially be used as nutraceuticals. Alcoholic liver disease (ALD) can range from simple steatosis or inflammation to fibrosis and cirrhosis, possibly through leaky gut and systemic endotoxemia. This study examined the liver and gut effects of red yeast rice (RYR) (Monascus purpureus) ethanol extract against binge ethanol-induced liver injury in mice. RYR extract was orally administered to C57BL/6N mice at a concentration of 200 mg/kg body weight per day for 10 days. Then, mice were administered binge alcohol (5 g/kg/dose) three times at 12 hr intervals. Binge alcohol exposure significantly elevated the endotoxin, aspartate aminotransferase (AST), and alanine transaminase (ALT) activity of plasma, as well as hepatic triglyceride levels; however, RYR treatments reduced these levels. In addition, RYR pretreatment significantly reduced the alcohol-induced oxidative maker protein and apoptosis maker in binge alcohol-induced gut and liver injuries. These results suggest that RYR may prevent alcohol-induced acute leaky gut and liver damage.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.441-446
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• 2018

Herbaceous biomass is easier at chemical conversion than woody biomass. However, pretreatment must be needed because it has substantially lignin. Organsolv is good at fractionation of enzymatic hydrolysis inhibitors such as lignin and it is reusable by distillation when it has low molecular weight. Flow-through process can prevent recondensation of fractionated components and easily separate liquid from the biomass. In this study, the pretreatment was performed for decreasing additional process by using ethanol without catalyst because this process has a lot of operation expense at bio-alcohol production process. Flow-through pretreatment was performed at $150{\sim}190^{\circ}C$ with 30~99.5 wt% ethanol during 20~60 minutes. Also the phsyco-chemical pretreatment was performed for decreasing reaction time and temperature.

• Journal of Applied Biological Chemistry
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• v.59 no.3
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• pp.215-220
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• 2016

Abstract Secondary cell wall is the most abundant biomass produced by plants. Plant secondary cell wall is composed of a complex mixture of cellulose, hemicellulose, and lignin. Lignin, a phenolic polymer that hinders the degradation of cell wall polysaccharides to simple sugars destined for fermentation to bio-ethanol. Cell wall biosynthesis pathway-specific biomass engineering offers an attractive 'genetic pretreatment' strategy to improve bioenergy feedstock. Recently, we found a transcription factor, MYB7, which is a transcriptional switch that may turns off the genes necessary for lignin biosynthesis. To gain insights into MYB7 mediated transcriptional regulation, we first established a dominant suppression system in Arabidopsis by expressing MYB7-SRDX. Then we used a transient transcriptional activation assay to confirm that MYB7 suppress the transcription of the lignin biosynthetic gene. Taken together, we conclude that MYB7 function as a repressor of the genes involved in the lignin biosynthesis.

• Textile Coloration and Finishing
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• v.35 no.4
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• pp.214-220
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• 2023

Poly(vinyl alcohol) (PVA) is a common hydrophilic polymer that is synthesized through the saponification reaction of poly(vinyl ester)-based polymers, mostly using poly(vinyl acetate) (PVAc) as a precursor. The heterogeneous saponification reaction of poly(vinyl ester)-based films leads to PVA films with new surface properties. Cellulose acetate (CA), in which the hydroxyl group of cellulose is replaced by an acetyl group, is a typical cellulose derivative capable of overcoming the low processability of cellulose due to strong hydrogen bonding. In this study, P(VAc/VPi)/CA blended films were prepared by the solvent casting, and then PVA/Cellulose blended films with improved surface properties were prepared by heterogeneous saponification. The structural changes caused by heterogeneous saponification were confirmed by FT-IR analysis, where both saponification and deacetylation reactions occurred in the saponification solution. In addition, the surface property changes were analyzed by FE-SEM and contact angle analyses, and the transmittance changes of the modified films were also assessed.

• Journal of the Korean Society of Food Culture
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• v.21 no.1
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• pp.71-75
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• 2006

This study was conducted to investigate the eliminatory effect of health drink containing Hovenia dulcis Thunb extract on ethanol-induced hangover in rats. Male Sprague-Dawley rats weighing $200{\pm}10\;g$ were given health drink (10 mL/kg) or other company product(10 mL/kg) 30 min before or after 40% ethanol (5 g/kg body weight) ingestion. To study the effect of health drink on blood ethanol concentration, blood was taken from caudal artery at 1, 3, 5 hr and the animal were sacrificed 24 hr after ethanol ingestion. From 1 to 5 hr, health drink pre- or postdosing significantly decreased the ethanol levels in the blood. The acetaldehyde concentration showed decrement in health drink group and other company product group. The activities of ethanol, alcohol dehydrogenase and aldehyde dehydrogenase measured at postdosing, were also not altered by the administration of health drink. Alanine aminotransferase and aspartate aminotransferase activities showed unaltered resulted in all experimental groups compared with the normal group. These results suggest that oral intake of health drink containing Hovenia dulcis Thunb is effective on elimination of ethanol-induced hangover.

• Clean Technology
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• v.28 no.3
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• pp.232-237
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• 2022

Biorefineries, in which renewable resources are utilized, are an eco-friendly alternative based on biomass feedstocks. Alginic acid, a major component of brown algae, which is a type of marine biomass, is widely used in various industries and can be converted into value-added chemicals such as sugars, sugar alcohols, furans, and organic acids via catalytic hydrothermal decomposition under certain conditions. In this study, ruthenium-supported activated carbon and magnesium oxide were mixed and applied to the depolymerization of alginic acid in a batch reactor. The addition of magnesium oxide as a basic promoter had a strong influence on product distribution. In this heterogeneous catalytic system, the separation and purification processes are also simplified. After the reaction, low molecular weight alcohols and organic acids with 5 or fewer carbons were produced. Specifically, under the optimal reaction conditions of 30 mL of 1 wt% alginic acid aqueous solution, 100 mg of ruthenium-supported activated carbon, 100 mg of magnesium oxide, 210 ℃ of reaction temperature, and 1 h of reaction time, total carbon yields of 29.8% for alcohols and 43.8% for a liquid product were obtained. Hence, it is suggested that this catalytic system results in the enhanced hydrogenolysis of alginic acid to value-added chemicals.