• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.28-34
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• 2021

SiO2/Ag core-shell nanoparticles were synthesized by combining modified Stöber process and reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane reverse micells. The SiO2/Ag core-shells were studied for structure, morphology and size using UV-visible spectroscopy, XRD, SEM and TEM. The size of a SiO2/Ag core-shell could be controlled by changing the [water]/[DDBA] molar ratio (WR) values. The size and the polydispersity of SiO2/Ag core-shells increased with increase of the WR value. The resultant Ag nanoparticles exhibit a strong surface plasmon resonance (SPR) peak at 430 nm over the amorphous SiO2 nanoparticles. The SPR peak shifted to the red side with increase in nanoparticle size. Conductive pastes with 70 wt% SiO2/Ag core-shell were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste film of the SiO2/Ag core-shell showed higher surface resistance than the commercial Ag paste in the range of 460~750 µΩ/sq.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.333-340
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• 2021

In this study, Rosa multiflora was sampled through extraction, concentration, and freezing. The antioxidant efficacy of a mixture of R. multiflora extract and ascorbic acid was compared with a single ascorbic acid. The purpose of this study was to analyze the antioxidant efficacy through the synergistic effect of R. multiflora extract and ascorbic acid. The experiment measured electron donating ability, ABTS+ radical scavenging, SOD-like activity, xanthine oxidase inhibition activity, reducing power, FRAP, polyphenolic content measurement, and flavnoid content measurement. As a result, the complex showed higher antioxidant activity than the control group (ascorbic acid) in the electron donating ability test and the xanthine oxidase inhibitory activity test. In the case of the flavonoid content experiment, it was confirmed that RMW+A (272.1 mg QE/g), RME+A (90.6 mg QE/g), and RMW+A (79.4 mg QE/g) at a concentration of 100 ㎍/mL had a higher flavonoid content than the control group (19.0 mg QE/g). Therefore, the extract and ascorbic acid complex exhibited a synergistic effect compared to the single use. Therefore, it is thought that this complex will contribute to product stabilization and skin aging inhibition when used in antioxidant cosmetics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.504-511
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• 1995

This study was conducted to investigate the superoxide dismutase (SOD) characteristics and antioxidant activity by nonenzymatic(Fe$^{2+}$/Ascorbate) and Fe$^{3+}$-ADP/NADPH method in perilla(Perilla frutescens var. japonica Hara.) and jaso(Perilla frutescens Briton var. acuta Kudo.) leaves. The characteristics were evaluated by the nitro blue tetrazolium reduction method. Perilla leaves contained three or four major SODs depending on the varieties. The inhibitor test indicated that the Perilla leaves contained two Cu /ZnSODs and one or two FeSODs, but Jaso leaves have only Cu/ZnSOD. However, no varietal differences were detected in the Cu /ZnSOD isozyme patterns. FeSODs, however, showed different varietal isozyme patterns through the different combinations of the two FeSOD isozymes. Among MeOH extractes, "mil yang 2" showed very strong antioxidant activity. Relatively large differences in the levels of SOD and antioxidant activity detected in the Perilla varietites. There was significantly different in the comparison between perilla leaves and red jaso leaves.s.etween perilla leaves and red jaso leaves.

• Journal of Life Science
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• v.33 no.1
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• pp.8-14
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• 2023

Peroxidasin (PXDN), a multidomain heme peroxidase containing extracellular matrix (ECM) motifs, as well as a catalytic domain, catalyzes the sulfilimine crosslink of collagen IV (Col IV) to reinforce Col IV scaffolds. We previously reported that PXDN is required for endothelial cell (EC) survival and growth signaling through sulfilimine crosslink-dependent matrix assembly. In this study, we examined whether peroxidase activity is required for PXDN function in ECs. First, we constructed a mutant PXDN by point mutation of two highly conserved amino acids, Q823 and D826, which are present in the active site of the peroxidase domain. After isolation of HEK293 clones highly expressing the mutant protein, conditioned medium (CM) was obtained after incubating the cells in serum-free medium for 24 hours and then analyzed by Western blot analysis under nonreducing conditions. The results revealed that the mutant PXDN formed a trimer and that it was cleaved by proprotein convertase-like wild-type (WT) PXDN. However, peroxidase activity was not detected in the CM containing the mutant PXDN, in contrast to that of WT PXDN. In addition, the sulfilimine crosslink ability of the mutant PXDN was lost. Moreover, the CM containing the mutant PXDN failed to promote the growth of PXDN-depleted ECs, unlike the CM containing WT PXDN. These results suggest that the peroxidase activity of PXDN affects EC growth by forming a sulfilimine crosslink.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.3
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• pp.95-120
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• 2023

Methane (CH₄) is a key greenhouse gas in the atmosphere with 85 times greater greenhouse potent relative to carbon dioxide (CO₂). The atmospheric concentration of CH₄ is rapidly increasing due to the intensive usage of CH₄ and the thawing of the cryosphere. Additionally, with the current warming of ocean water, the dissociation of gas hydrates, an ice-like compound and the largest reservoir of CH₄ on Earth, is expected to occur, resulting in the release of CH₄ from the seafloor into the overlying water and atmosphere. Moreover, bottom water hypoxia is another concern that potentially introduces greenhouse gases into the atmosphere. With ongoing global warming and eutrophication, the size and duration of bottom water hypoxia are rapidly increasing. These low-oxygen conditions would relocate the redox zone shallower in sediment or in the water column, causing the release of CH₄ into the atmosphere and thereby intensifying global warming. However, there exists a gap in the understanding of CH₄ dynamics including its generation in relation to bottom water hypoxia. Therefore, this review article aims to understand the relationship between CH₄ and bottom water hypoxia and to draw attention to CH₄ investigation in Korea.

• Asia Marketing Journal
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• v.9 no.3
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• pp.209-232
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• 2007

두산은 2001년에 <산> 소주 제품으로 소주시장에 진입하였지만, 2002년도에 6.7%였던 <산> 소주의 시장 점유율이 2004년도 들어서서 5.4% 로 하락하였고, 선호도 역시 매우 낮은 수준으로 조사되어, 원인분석과 함께 새로운 소주에 대한 개발 필요성이 대두되었다. 당시 두산은 시장 선도 브랜드인 <참이슬>의 충성 고객층은 감소하면서 비호감 고객층이 증가하는 등 소주에 대한 고객의 욕구가 변화하고 있다는 시장조사 결과에서 성공의 기회를 엿볼 수 있었다. 그리고 1인당 알코올 소비량은 감소하였으나 소주의 소비량은 연간 70병으로 일정한 소비를 나타나고 있었기 때문에, 소주시장의 매력도는 아직 충분히 존재한다고 판단하였다. 그리하여 두산이 목표로 삼을 표적시장 선정을 위한 시장조사를 대대적으로 시작하였는데, 소주 음용 조사에서 30~40대의 남성들은 소비량이 감소하는 반면 여성들의 소주 소비량은 전 연령대에 걸쳐 증가하는 것으로 나타났다. 여기에서 두산은 새로운 소주시장에 대한 신제품 개발의 기회를 발견하고, 신제품 개발 프로젝트에 착수하게 되었다. 이를 위해 먼저 소주 트렌드의 변화와 소비자들의 라이프 스타일을 살펴보고, 이를 통해 '웰빙'을 신제품의 주요가치로 결정하게 된다. 이후 시장 세분화 조사를 통해 다량음용자(heavy user)가 많은 품질 중시 시장과 도수 및 숙취 중시 시장에 진입하기로 한다. 그 다음 소주에 대한 소비자들의 불만족 요인이 무엇인지 살펴보고 이를 해결하기 위한 대안들을 탐색한다. 그 결과 '목 넘김이 부드럽고, 몸의 산성화를 중화시키며, 숙취 해소'에 뛰어난 '알칼리수'를 신제품의 주원료로 사용한 <처음처럼>을 개발하게 된다. 소주의 주요 속성별 선호도 조사를 실시한 결과, 모든 속성에서 <처음처럼>이 경쟁사 제품보다 뛰어난 것으로 나타나 두산은 <처음처럼>을 시장에 출시하게 되었다. <처음처럼>은 24~35세를 목표 고객으로 설정하고, 유흥업소가 밀집한 중심상권을 집중적으로 공략하였다. 이를 위해 저가 정책을 실시하여 유통업체의 마진을 높였으며, 다양한 광고, 촉진 전략을 통해서 소비자 인지도를 향상시켰다. 그 결과 수도권 및 전국 지역에서 지속적으로 시장점유율이 증가하였으며, 소비자들에게 <참이슬>과 차별화된 이미지를 구축하게 되었다. <처음처럼>이 성공적으로 시장에 진입할 수 있었던 이유로는 알칼리수 사용, 감성적 브랜드명 채택, 차별화된 마케팅 전략 구사, 그리고 조직원의 강력한 성공 의지 등을 들 수 있다. 소주 시장의 독보적 존재였던 <참이슬>과의 경쟁에서 이루어진 결과라는 점에서 <처음처럼>의 사례는 많은 기업들에게 시사점을 제공할 수 있다. 하지만 현재 '대중성'이나 '친근감'같은 이미지가 <참이슬>에 비해 상대적으로 낮고, <참이슬 fresh>의 출시로 인해 목표 고객인 20대가 이탈되는 문제는 앞으로 <처음처럼>이 극복해야 할 과제이다. 이를 위해 <처음처럼>은 무엇보다 '웰빙 소주'로서의 이미지를 확고히 하기 위한 마케팅 전략을 실행하여야 할 것이다.

• Applied Biological Chemistry
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• v.27
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• pp.29-46
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• 1984

To utilize several species of hard wood as raw materials of feed products, fermentation characteristics of cellulosic substrates to single cell protein was investigated, and results were summarized as follows. Among the microorganisms investigated, Tricoderma viride was selected as one of the most cellulolytic. Mixed culture of fungi did not show a synergistic effect on cellulose degradation. When the fungi were cultured at $28^{\circ}C$ for 7 days in a medium containing wheat bran 25 g, cellulose 0.25 g, proteose peptone 0.025 g and tween 800.025 g, cellulotic activities on carboxy methyl cellulose and filter paper reached maximum at 12 hr. The alkali treatment resulted in increased degradation of substrate from 13 to 18% when treated with enzymes for 12h, and reducing sugar formation increased with decreased size of substrates. Glucose was a very good feedback inhibitor of the enzyme from T.viride than that of xylose. When the substrate was rehydrolyzed, hydrolysis rate was 31% to reducing sugars within 12 hr. Quantative anlysis with HPLC showed the ratio of glucose to xylose in sugar syrups as 1.77 to 1. For the purpose of producing cellulosic-single cell protein from the sawdust of mulberry tree, 15 strains of xylose-assimilating yeast were isolated from 42 samples of rotten woods and compost soils and examined for their ability to utilize xylose. Then three strains were selected by their strong xylose-assimilating activities. The cultivative condition, the growth characteristics, and protein and nucleic acid productivities of three strains were investigated. The results obtained were, 1. Wood hydrolysate of mulberry tree was assimilated by 5 strains of CHS-2, CHS-3, ST-40, CHS-12 and CHS-13. 2. The optimum initial pH and temperature for the growth of strain CHS-13 were 4.4 and $30^{\circ}C$. 3. The specific growth rate of strain CHS-13 was $0.23h^{-1}$ and generation time was 3.01 hrs at the optimum condition. 4. CHS-13 strain assimilated 81 % of sugar in wood hydrolysate. 5. CHS-13 strain was identified as Candida guilliermondii var. guilliermondii 6. When the CHS-13 strain was cultured in the wood hydrolysate containing yeast extract, L-protein content was increased with yeast extract concentration. 7. The L-protein and nucleic acid yields from wood hydrolysate were 0.73 mg/ml and $4.92{\times}10^{-2}\;mg/ml$ respectively. 8. An optimal nucleic acid content of CHS-13 strain was observed in the medium containing 0.2% of yeast extract.

• Culinary science and hospitality research
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• v.8 no.3
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• pp.309-321
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• 2002

In this study, the characteristics of Jeung-pyun hatter were investigated by wine yeast. The processing conditions were optimized by physicochemical characterization including pH, volume, reduced sugar. The effect of yeast concentration, moisture content on the fermentation time and temperature were investigated in view of improving productivity. It was found that the volume was increased at maximum state when the fermentation was carried out at 35 $^{\circ}C$ with 0.1% yeast concentration 60% of moisture. The quality of Jeung-Pyun was most preferable in the condition of 0.1% wine yeast(Pasteur Red) for 8 hrs at 35$^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.72-78
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• 1997

The levels of reducing sugars, organic acids and fatty acids, known as precursors of major flavors induced from dried sellfish, were analyzed to investigate their behaviors during drying process. Free reducing sugar contents were markedly decreased in all samples by boiling, Its content in Blue mussel and Short-necked calm samples significantly decreased after drying process. Among the eight different organic acids from blue mussel, Short-necked calm and Pacific oyster samples, succinic acid in blue mussel and short-necked calm samples was measured with $74.9\%\;and\;67.4\%$, respectively. In the sample of Pacific oyster, succinic acid content was found to be $38.4\%$, but pyroglutamic acid content was the highest level with $41.6\%$. Contents of organic acids with exception succinic acid were significantly reduced in all three samples of sun-dried or hot-air dried. The content of succinic acid in the samples of sun-dried and hot-air dried pacific oyster reduced to $53.0\%\;and\;44.2\%$, respectively, but relatively small decrease $(29.0\%\;and\;10.0\%)$ was observed in sun-dried and hot-air dried short-necked calm samples, respectively. Content of polar lipid with the major fatty acids profile of C16:0, C16:1, C20:5 and C22:6 was consisted of $59.1\%,\;66.7\%\;and\;42.4\%$, respectively, in blue mussel, short-necked calm and pacific oyster samples and the content of polyene fatty acids was appeared to be $40.5\%,\;48.6\%\;and\;48.9\%$, respectively. Relatively high peroxide value in all boiled-dried products samples was found to be $41.64\~86.80\;meq/kg$ sample. Carbonyl value in boiled-dried products samples was found to be $15.55\~27.99\;meq/kg$, but its value in broiled products samples was significantly high level of $127.6\~136.5\;meq/kg$.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.4
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• pp.177-191
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• 1998

For various kinds of waters including surface water, shallow groundwater (＜70 m deep) and deep groundwater (500∼810 m deep) from the Pungki area, an integrated study based on hydrochemical, multivariate statistical, thermodynamic, environmental isotopic (tritium, oxygen-hydrogen, carbon and sulfur), and mass-balance approaches was attempted to elucidate the hydrogeochemical and hydrologic characteristics of the groundwater system in the gneiss area. Shallow groundwaters are typified as the 'Ca-HCO$_3$'type with higher concentrations of Ca, Mg, SO$_4$and NO$_3$, whereas deep groundwaters are the 'Na-HCO$_3$'type with elevated concentrations of Na, Ba, Li, H$_2$S, F and Cl and are supersaturated with respect to calcite. The waters in the area are largely classified into two groups: 1) surface waters and most of shallow groundwaters, and 2) deep groundwaters and one sample of shallow groundwater. Seasonal compositional variations are recognized for the former. Multivariate statistical analysis indicates that three factors may explain about 86% of the compositional variations observed in deep groundwaters. These are: 1) plagioclase dissolution and calcite precipitation, 2) sulfate reduction, and 3) acid hydrolysis of hydroxyl-bearing minerals(mainly mica). By combining with results of thermodynamic calculation, four appropriate models of water/ rock interaction, each showing the dissolution of plagioclase, kaolinite and micas and the precipitation of calcite, illite, laumontite, chlorite and smectite, are proposed by mass balance modelling in order to explain the water quality of deep groundwaters. Oxygen-hydrogen isotope data indicate that deep groundwaters were originated from a local meteoric water recharged from distant, topograpically high mountainous region and underwent larger degrees of water/rock interaction during the regional deep circulation, whereas the shallow groundwaters were recharged from nearby, topograpically low region. Tritium data show that the recharge time was the pre-thermonuclear age for deep groundwaters (＜0.2 TU) but the post-thermonuclear age for shallow groundwaters (5.66∼7.79 TU). The $\delta$$\^$34/S values of dissolved sulfate indicate that high amounts of dissolved H$_2$S (up to 3.9 mg/1), a characteristic of deep groundwaters in this area, might be derived from the reduction of sulfate. The $\delta$$\^$13/C values of dissolved carbonates are controlled by not only the dissolution of carbonate minerals by dissolved soil CO$_2$(for shallow groundwaters) but also the reprecipitation of calcite (for deep groundwaters). An integrated model of the origin, flow and chemical evolution for the groundwaters in this area is proposed in this study.