• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1559-1565
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• 2014

Cellulase and xylanase are main hydrolysis enzymes for the degradation of cellulosic and hemicellulosic biomass, respectively. In this study, our aim was to develop and test the efficacy of a rapid, high-throughput method to screen hydrolytic-enzyme-producing microbes. To accomplish this, we modified the 3,5-dinitrosalicylic acid (DNS) method for microwell plate-based screening. Targeted microbial samples were initially cultured on agar plates with both cellulose and xylan as substrates. Then, isolated colonies were subcultured in broth media containing yeast extract and either cellulose or xylan. The supernatants of the culture broth were tested with our modified DNS screening method in a 96-microwell plate, with a $200{\mu}l$ total reaction volume. In addition, the stability and reliability of glucose and xylose standards, which were used to determine the enzymatic activity, were studied at $100^{\circ}C$ for different time intervals in a dry oven. It was concluded that the minimum incubation time required for stable color development of the standard solution is 20 min. With this technique, we successfully screened 21 and 31 cellulase- and xylanase-producing strains, respectively, in a single experimental trial. Among the identified strains, 19 showed both cellulose and xylan hydrolyzing activities. These microbes can be applied to bioethanol production from cellulosic and hemicellulosic biomass.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.234-241
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• 2017

Potato peels (PP) contain several bioactive compounds. These compounds are known to provide human health benefits, including antioxidant and antimicrobial properties. In addition, these compounds could have effects on human enteric viruses that have not yet been reported. The objective of the present study was to evaluate the phenolic composition, antioxidant properties in the acidified ethanol extract (AEE) and water extract of PP, and the antiviral effects on the inhibition of Av-05 and MS2 bacteriophages, which were used as human enteric viral surrogates. The AEE showed the highest phenolic content and antioxidant activity. Chlorogenic and caffeic acids were the major phenolic acids. In vitro analysis indicated that PP had a strong antioxidant activity. A 3 h incubation with AEE at a concentration of 5 mg/ml was needed to reduce the PFU/ml (plaque-forming unit per unit volume) of Av-05 and MS2 by 2.8 and $3.9log_{10}$, respectively, in a dose-dependent manner. Our data suggest that PP has potential to be a source of natural antioxidants against enteric viruses.

• Journal of the Korean Institute of Gas
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• v.3 no.3 s.8
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• pp.1-8
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• 1999

Three-point bending fatigue properties of austenitic 304 stainless steel sheets were investigated at room temperature and LNG temperature($-162^{\circ}C$) in the strain range from 0.43 to $1.7\%$. The fatigue properties at $-162^{\circ}C$ were superior to those at room temperature due to the higher volume fractions of deformation-induced martensite. The cyclic hardening behavior owing to the deformation- induced martensite transformation was detected in both specimens. In room temperature testing, the mean load amplitude increased steadily with cycles, meaning that cumulative plastic incubation strain was required for martensite transformation. On the contrary, in $-162^{\circ}C$ tested specimen, the mean load amplitude increased rapidly within a few cycles due to the rapid transformation of martensite, and slightly decreased after the maximum is reached probably due to dynamic recovery.

• Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.264-275
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• 2022

A non-destructive environmental DNA protocol for the genetic analysis of sea cucumber (Apostichopus japonicus) resources DNA was established. Among the several commercial DNA extraction kits, the DNeasy^® Plant Mini Kit was selected as the best choice to obtain the high-quality genomic DNAs from the mucous sea cucumber. As the temperature and incubation time increased, the amount of extracted environmental DNA was also large, but it was judged that the increased amount did not affect as much as 2-3 times. Therefore, these conditions were not considered to be the main factors to consider in actual environmental DNA extraction. However, the amount of seawater relative to the size of the sample was judged as a major consideration, and a sufficient amount of environmental DNA for analysis was secured when stored within 1 min while stirring the volume of seawater corresponding to the total sea cucumber weight (g). In securing the environmental DNA of sea cucumbers, the mortality rate of sea cucumbers in all experiments was 0, and it was judged that the effects of sea cucumbers were not significant through this treatment. Through the results of this study, sea cucumber DNA research, which has been conducted in a destructive method, can be conducted non-destructively through environmental DNA analysis. Through this study, we have secured a standard protocol that can successfully extract the sea cucumber DNA through environmental DNA. It is not only excellent in terms of time and cost of traditional DNA analysis method currently used, but it is completely non-destructive in the ecosystem of the survey area. It is believed that the system can be transformed in a way that does not affect it. However, it is thought that various standard protocols should be established considering the characteristics of each type.

• Nutrition Research and Practice
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• v.18 no.4
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• pp.479-497
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• 2024

BACKGROUND/OBJECTIVES: Activating brown adipose tissue (BAT) and browning of white adipose tissue (WAT) can protect against obesity and obesity-related metabolic conditions. Cryptotanshinone (CT) regulates lipid metabolism and significantly ameliorates insulin resistance. Adenosine-5'-monophosphate (AMP)-activated protein kinase (AMPK), a receptor for cellular energy metabolism, is believed to regulate brown fat activity in humans. MATERIALS/METHODS: The in vivo study included high-fat-fed obese mice administered orally 200/400 mg/kg/d CT. They were evaluated through weight measurement, the intraperitoneal glucose tolerance test (IPGTT), intraperitoneal insulin tolerance test (IPITT), cold stimulation test, serum lipid (total cholesterol, triglycerides, and low-density lipoprotein) measurement, hematoxylin and eosin staining, and immunohistochemistry. Furthermore, the in vitro study investigated primary adipose mesenchymal stem cells (MSCs) with incubation of CT and AMPK agonists (acadesine)/inhibitor (Compound C). Cells were evaluated using Oil Red O staining, Alizarin red staining, flow cytometry, and immunofluorescence staining to identify and observe the osteogenic versus adipogenic differentiation. Quantitative real-time polymerase chain reaction and the Western blot were used to observe related gene expression. RESULTS: In the diet-induced obesity mouse model mice CT suppressed body weight, food intake, glucose levels in the IPGTT and IPTT, serum lipids, the volume of adipose tissue, and increased thermogenesis, uncoupling protein 1, and the AMPK pathway expression. In the in vitro study, CT prevented the formation of lipid droplets from MSCs while activating brown genes and the AMPK pathway. AMPK activator enhanced CT's effects, while the AMPK inhibitor reversed the effects of CT. CONCLUSION: CT promotes adipose tissue browning to increase body thermogenesis and reduce obesity by activating the AMPK pathway. This study provides an experimental foundation for the use of CT in obesity treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1640-1646
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• 2010

The optimum condition was investigated for the extraction of glycosaminoglycan (GAG) from sea hare, Aplysia kurodai. The most effective enzyme was Flavourzyme for extraction of glycosaminoglycan. The optimum incubation temperature and time for hydrolysis were $60^{\circ}C$ and 15 hr, respectively. The yield of precipitated polysaccharide depended on Brix and ethanol volume. The most effective concentration of Brix and ethanol were sixty and 5 volume of ethanol, respectively. Most GAG was eluted between 0.5 M and 0.75 M NaCl gradient on DEAE-Sepharose column, and identified by electroconductivity. The contents of hexuronic acid from polysaccharide extract and GAG were 1.0 g/100 g and 6.0 g/100 g, respectively. Hexosamine of polysaccharide and GAG as indicator of GAG component was 5.6 g/100 g and 25.7 g/100 g, respectively. GAG was identified as heparan sulfate compared with bands of other GAG on agarose gel electrophoresis, and its molecular weight was 29.6 kDa on Superdex 200 HR column.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.291-298
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• 2003

A bacterial strain producing a high level of an extracellular phytase was isolated from livestock waste water, identified as a strain of Pseudomonas fragi and designated as Pseudomonas fragi Y9451. Under the phytase production medium, the activity of phytase reached the highest level after 120 hours of incubation. On the effect of carbon sources on the phytase production, the most favorable carbon source for phytase production was fructose. As for the effect of nitrogen sources, high levels of phytase activity were detected in the medium containing nutrient broth as the nitrogen source. Free $PO_4^{3-}$ inhibited phytase production with increasing concentration of $KE_2PO_4$ and phytate in the media. The addition of $CaCl_2$ and $MgSO_4$ also resulted in the inhibition of phytase production. To investigate the effect of aeration on the phytase production, different volumes of culture broth in Erlenmeyer flasks were incubated in rotary shaker at the speed of 200 rpm. As a result, a high level of phytase activity was detected at small volume of culture broth as compared to larger volume because of its more aerobic condition.

• Journal of Mushroom
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• v.17 no.3
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• pp.126-131
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• 2019

This study sought to identify the optimum substrate composition for the stable bottle cultivation of Sparassis latifolia. The main substrate was fermented larch sawdust. Six nutrient sources were mixed at a maximum volume ratio of 20%. The fresh weight of fruit body was the highest at 128.5 g for GMSL69033 and 126.6 g for 'Neoul' in the treatments of beet pulp and corn flour in a volume ratio of 15:5. In addition, the total cultivation period was 94 days, which was shorter than that required for other treatments. The selected substrate characteristics were pH 4.7, C:N (carbon to nitrogen) ratio of 106:4, moisture content of 70%, and air filling porosity of 38%. We plan to develop new income items through research on mycelial incubation and fruit body growth conditions.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.1
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• pp.177-189
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• 2022

This study proposes policy recommendations for the Korea New Exchange ("KONEX"), which is a financial platform for SMEs and startups that relied on indirect and policy financing in the past. SMEs and venture firms with limited human and physical listing resources can grow through market incubation, and venture capitalists expect an early exit or return on investment. However, the lack of liquidity and sluggish trading volume have weakened the function of the market. Despite prior policy efforts, the number of newly listed companies has decreased while listing demand for KOSDAQ and K-OTC has increased. This study aims to suggest short- and long-term improvements in regulations and throughout the KONEX firms' listing life cycle. First, the minimum deposit requirement on individual investors should be abolished to increase the number of investors. Second, information disclosure should be conducted by firms so that the nominated advisor can focus on discovering and supporting new listed companies. Third, in order to increase trading volume, the 5% dispersion rule should be changed to 25% dispersion incentive principle. Fourth, a new track without profit condition in expedited transfer listing should be introduced because the KOSDAQ relaxes the profit realization requirements for listing. Lastly, transfer listing without additional review for firms that fulfill ownership dispersion, information disclosure, and investor protection will strengthen the incubating role of the KONEX.

• Journal of Aquaculture
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• v.18 no.1
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• pp.19-25
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• 2005

This study was performed to investigate the optimum density for the intensive mass production of cyclopoid copepod, Paracyclopina nana in terms of nauplii and adults production. Effect of three development stages on the fecundity of adult female for nauplii production, survival rate of P. nana nauplii with different initial nauplii culture densities for adults production and cannibalistic feeding behavior of P. nana was examined, respectively. The fecundity of adult female by different female, copepodite ana nauplii density in 2 ml water volume decreased with the density of adult female, but was not affected by the density of either copepodite or nauplii. The average daily nauplii production for a adult female in 8 L water volume was $2.3{\times}10^5$ individuals with the incubation density of 7 adult females/ml, and this average value was significantly higher than those values of 0.6 to $1.7\times10^5$ individuals with the incubation density of 1,3,5, 10 adult females/ml (P<0.05). Survival rate of P. nana nauplil with different initial nauplii culture densities in 5 L vessels for 15 days were 32.7, 30.7, 28.9 and $23.0\%$ with the culture density of 50, 100, 150 and 200 inds./ml, respectively, but these were significantly higher than those of values 19.7 and $18.4\%$ with the culture density of 250 and 300 inds./ml (P<0.05). Cannibalistic behavior of P. nana adults on their offspring was observed, but the behavior decreased when phytoplankton was supplemented though there was no statistical difference (P>0.05). These results may indicate that P. nana is adaptable to the hatchery conditions and this species is cultured at the high densities. Optimum culture density for nauplii and adults production of P. nana were 7 adult females/ml and 200 nauplii/ml, respectively.