• Title/Summary/Keyword: 촉매제

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A Study on the Directions of Sewol Ferry Tragedy Memorial Park Based on the Analysis on Social Discourse and Recognition Evaluation (도심형 메모리얼파크의 사회적 담론 및 인식분석을 통한 4·16 세월호 참사 추모공원 방향성 제안 연구)

  • Kim, Do-Hun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.6
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    • pp.25-38
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    • 2020
  • The objective of this study is to propose a direction for creating a memorial park for the 250 students victims of the Sewol ferry disaster. To this end, this study first attempted to understand the matters discussed at various levels to create a memorial park and find a way that the park can be built by gathering opinions from the bereaved families and the victims themselves, as well as local residents, and experts. Workshops, competitions, special lectures, and websites, etc, were analyzed. A social discourse analysis methodology was used for systematic analysis, and the analyzed discourse was categorized into 4 types for assessment, and the functions and roles were subdivided into 15 types. To assess the priorities and the adequacy of the discourse, an analytic hierarchy process (AHP) was used among 30 activists, public servants, and experts. Then, a survey was conducted to analyze the perception of the residents (467 participants including the bereaved families) about the memorial park. Based on the results of the analysis, two directions were set for the memorial park. First, is a memorial park to remember the victims in everyday life. It must be a park with various cultural contents instead of a conventional memorial park that is solemn and grave sharing anguish and sorrow. The memorial park for the Sewol ferry disaster must become a space where visitors can naturally encounter and remember the victims. Second, is a park that serves as a catalyst that brings change and innovation to the community. It must be able to bring change to the community with direct and indirect influence. It must serve as an impetus to bring change and innovation to the community in the mid-to-long-term. Having many visitors may also lead to an economic effect. These visitors may not just stay in the park, but even contribute to revitalizing the local businesses. The purpose of this study is to apply the research findings to guide the International Design Competition scheduled for 2020 and serve to establish guidelines for a continuous park management system.

The Korean Girl Group Kara's Differentiation Strategy Which Overcome the Trilemma and Led to the Great Reversal Success (삼중고 탈피 후 대역전의 성공을 이끈 걸 그룹'카라'의 차별화 전략)

  • Kim, Jeong-Seob
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.2
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    • pp.169-178
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    • 2021
  • The Korean girl group "Kara" has suffered the trilemma of its de facto failure to debut, the crisis of team breakup, and the CEO crisis of the agency. But the group has made an outstanding achievement in the history of Korean pop music after overcoming all odds. Their success strategy has never been disclosed by insiders involved in Kara's total music projects. This study has been carried out in the analysis of the strategy to provide academic implications and to honor the contribution of the late CEO Ho-yeon Lee and Kara's key member Ha-ra Gu. Therefore, between Nov. and Dec. 2020, we conducted in-depth interviews with managers, composers, stylists and Ha-ra Gu(Only in 2019, before her death) who took part in the project. The research model is set up by combining Porter's Competitive Advantage Strategy and the music value chain model into categories of "Product Innovation Differentiation (PD)" (producing, album production, performance activities) and "Marketing Differentiation (MD)" (market targeting, image specialization, promotion and communication). The analysis showed that the PD focused on complete rediscovered harmonization and revalued members' personality and sincerity with peppy songs and dainty dances as well as emission of "bright energy" which caused healing effects instead of mimicking other star singers recklessly. In terms of MD, they selected Japan's 10-20s as their main market, increasing intimacy with fans and media with the image of cute+pretty+classy+sexy. The result suggests that Poter's differentiation can function as a meaningful strategy frame in the fostering, hit, and revival of idol groups. In addition, it reaffirmed that spontaneous and passionate activities of early-stage or celebrity fan may serve as a valid catalyst for realizing differentiation, as Kara's caller of Japanese actor Gekidan Hitori caused a strong "priming effect" that drove Kara's unexpected wonderful success in Japan.

A Novel Synthesized Tyrosinase Inhibitor, (E)-3-(4-hydroxybenzylidene) chroman-4-one (MHY1294) Inhibits α-MSH-induced Melanogenesis in B16F10 Melanoma Cells (신규 합성물질 (E)-3-(4-하이드록시벤질리딘)크로마논 유도체의 티로시나아제 효소활성 저해 및 멜라닌 생성 억제 효과)

  • Jeon, Hyeyoung;Lee, Seulah;Yang, Seonguk;Bang, EunJin;Ryu, Il Young;Park, Yujin;Jung, Hee Jin;Chung, Hae Young;Moon, Hyung Ryong;Lee, Jaewon
    • Journal of Life Science
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    • v.31 no.8
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    • pp.719-728
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    • 2021
  • Melanin pigments are abundantly distributed in mammalian skin, hair, eyes, and nervous system. Under normal physiological conditions, melanin protects the skin against various environmental stresses and acts as a physiological redox buffer to maintain homeostasis. However, abnormal melanin accumulation results in various hyperpigmentation conditions, such as chloasma, freckles, senile lentigo, and inflammatory pigmentation. Tyrosinase, a copper-containing enzyme, plays an important role in the regulation of the melanin pigment biosynthetic pathway. Although several whitening agents based on tyrosinase inhibition have been developed, their side effects, such as allergies, DNA damage, mutagenesis, and cytotoxicity of melanocytes, limit their applications. In this study, we synthesized 4-chromanone derivatives (MHY compounds) and investigated their ability to inhibit tyrosinase activity. Of these compounds, (E)-3-(4-hydroxybenzylidene)chroman-4-one (MHY1294) more potently inhibited the enzymatic activity of tyrosinase (IC50 = 5.1±0.86 μM) than kojic acid (14.3±1.43 μM), a representative tyrosinase inhibitor. In addition, MHY1294 showed competitive inhibitory action at the catalytic site of tyrosinase and had greater binding affinity at this site than kojic acid. Furthermore, MHY1294 effectively inhibited α-melanocyte stimulating hormone (α-MSH)-induced melanin synthesis and intracellular tyrosinase activity in B16F10 melanoma cells. The results of the present study indicate that MHY1294 may be considered as a candidate pharmacological agent and cosmetic whitening ingredient.

A Study for Kinetics and Oxidation Reaction of Alcohols using (C10H8N2H)2Cr2O7 ((C10H8N2H)2Cr2O7를 이용한 알코올들의 산화반응과 반응속도에 관한 연구)

  • Park, Young-Cho;Kim, Soo-Jong
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.927-933
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    • 2022
  • We synthesized (C10H8N2H)2Cr2O7, The structure of the product was characterized with FT-IR(infrared) and elemental analysis. The oxidation of benzyl alcohol by (C10H8N2H)2Cr2O7 in organic solvents showed that the reactivity increased with the increase of the dielectric constant. The oxidation of alcohols was examined by (C10H8N2H)2Cr2O7 in DMF, acetone. As a resuit, (C10H8N2H)2Cr2O7 was found as efficicent oxidizing agent that converted benzyl alcohol, allyl alcohol, primary alcohol and secondary alcohols to the corresponding aldehydes or ketones(65%~95%). The selective oxidation of alcohols was also examined by (C10H8N2H)2Cr2O7 in DMF, acetone. (C10H8N2H)2Cr2O7 was selective oxidizing agent(15%~95%) of benzyl alcohol, allyl alcohol and primary alcohol in the presence of secondary ones. In the presence of DMF solvent with acidic catalyst such as H2SO4. (C10H8N2H)2Cr2O7 oxidized benzyl alcohol(H) and its derivatives. The Hammett reaction constant(ρ) was -0.69(308K). The observed experimental data were used to rationalize the hydride ion transfer in the rate determining step.

Nitrogen and Oxygen Sorption Behaviors of Ruthenium-Substituted SBA 15(Ru-SBA-15) (루테늄이 치환된 SBA-15(Ru-SBA-15)의 질소 및 산소 흡착 거동)

  • Seo, Yoon-Ah;Kim, Hyung Kook;Shin, Jeong Hun;Kim, Il;Ha, Chang-Sik
    • Korean Chemical Engineering Research
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    • v.47 no.5
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    • pp.608-614
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    • 2009
  • In this work, ruthenium substituted SBA-15's(Ru-SBA15's) of various Si/Ru ratios were prepared using a non-ionic triblock copolymer surfactant, $EO_{20}PO_{70}EO_{20}$, as template. We investigated the nitrogen or oxygen adsorption/desorption behaviors of the Ru-SBA-15's for their future applications as catalysts or selective adsorbents, etc. The pore size of the Ru-SBA-15's was determined by both the Barrett-Joyner-Halenda(BJH)($D_{BJH}$) and the Broekhoff-de Boer analysis with a Frenkel-Halsey-Hill isotherm(BdB-FFF) method($D_{BdB-FHH}$). The $D_{BJH}$ and $D_{BdB-FHH}$ of the Ru-SBA-15 having 50/1 ratio of Si/Ru were 3.9 nm and 4.7 nm, respectively. The transmission electron microscope(TEM) image of the Ru-SBA 15 of the Si/Ru mole ratio of 50 showed that the pore size is 4.7 nm, which is consistent with the $N_2$ adsorption results with the BdB-FHH method. The surface area of pores form oxygen adsorption/desorption isotherm was higher than that from the nitrogen adsorption/desorption isotherm by the Brunauer-Emmett-Teller(BET) method, which were respectively $612.7m^2/g$, and $573.3m^2/g$. X-ray diffraction(XRD) patterns and TEM analyses showed that the mesoporous materials possess well-ordered hexagonal arrays.

Spectrofluorometric Characteristics of the N-Terminal Domain of Riboflavin Synthase (아미노-말단 리보플라빈 생성효소 단백질의 형광 특성)

  • Kim, Ryu-Ryun;Yi, Jeong-Hwan;Nam, Ki-Seok;Ko, Kyung-Won;Lee, Chan-Yong
    • Korean Journal of Microbiology
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    • v.47 no.1
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    • pp.14-21
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    • 2011
  • Riboflavin synthase catalyzes the formation of one molecule of each riboflavin and 5-amino-6-ribitylamino-2,4-pyrimidinedione by the transfer of a 4-carbon moiety between two molecules of the substrates, 6,7-dimetyl-8-ribityllumazine. The most remarkable feature is the sequence similarity between the N-terminal half (1-97) and the C-terminal half domain (99-213). To investigate the structure and fluorescent characteristics of the N-terminal half of riboflavin synthase (N-RS) in Escherichia coli, more than 10 mutant genes coding for the mutated N-terminal domain of riboflavin synthase were generated by polymerase chain reaction. The genes coding for the proteins were inserted into pQE vector designed for easy purification of protein by 6X-His tagging system, expressed, and the proteins were purified. Almost all mutated N-terminal domain of riboflavin synthases bind to 6,7-dimethyl-8-ribityllumazine and riboflavin as fluorescent ligands. However, N-RS C47D and N-RS ET66,67DQ mutant proteins show colorless, indicating that fluorescent ligands were dissociated during purification. In addition, most mutated proteins show low fluorescent intensity comparing to N-RS wild type, whereas N-RS C48S posses stronger fluorescent intensity than that of wild type protein. Based on this result, N-RS C48S can be used as the tool for high throughput screening system for searching for the compound with inhibitory effect for the riboflavin synthase.

Production of L-α-Glycerophosphate Oxidase by streptococcus faecium M74 · LC (Streptococcus faecium M74 · LC에 의한 L-α-Glycerophosphate Oxidase의 생산)

  • Lee, In-Ae;Lee, Eun-Sook;Lee, June-Woo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.5
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    • pp.684-688
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    • 2003
  • The objective of this study was to search for the best strain as a source of L- $\alpha$-glycerophosphate oxidase (GPO) production and to establish the process technology for the purification of GPO on an industrial scale. The GPO was produced by culturing Streptococcus faecium, and purified by ammonium sulfate, DEAE-cellulose and hydroxyapatite chromatography. The relative activity was 60 units/L for 5. faecim ATCC 12755, 65 units/L for 5. faecium ATCC 19634, and 67 units/L for 5. faecium $M_{74}$.LC, respectively. The optimum condition for fermentation was $37^{\circ}C$ for temperature, 300 rpm for stir rate, 0.5 L/min for aeration rate and 17 hours. The main culture medium prepared by the modified AC medium. AC medium consists of 0.1% glucose, 0.2% glycerol, 1.0% tryptone and 1.0% yeast extract, 0.5% $K_2HP0_4$, pH 7.0. The GPO was purified by ammonium sulfate fractionation and ion exchange column chromatography, The yield and purity were 17.2% and 5.3 fold, respectively.

Derivatization and Residual Determination of MCPP in Soil Leachate (토양 침투수중 MCPP의 유도체화 및 잔류분석)

  • Hong, Moo-Ki;Smith, Albert E.
    • Korean Journal of Environmental Agriculture
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    • v.13 no.2
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    • pp.199-208
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    • 1994
  • Analytical methods for the determination of the derivatives of the herbicide (${\pm}$)-2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) by capillary column gas chromatography with mass spectrometer (GC-MS) and electron-capture detection (GC-ECD) were studied. A successful procedure was introduced for the ester preparation using $H_2SO_4$, as the catalyst and the alcohol 2,2,2-trichloroethanol (TCE) or 2,2,2-trifluoroethanol (TFE). The identificaiton and elucidation of MCPP by GC-MS spectrometry following the esterification with diazomethane, $BF_3$/methanol, $H_2SO_4$/methanol, TCE, TFE, or pentafluorobenzyl bromide (PFB) were carried out. A comparison of the response-sensitivities among those MCPP esters was made with GC-ECD. Although the methylation product of MCPP was confirmed by GC-MS, its low sensitivity to the ECD limited the detection of MCPP. TCE, TFE, and PFB derivatization methods resulted in a high rate of MCPP esterifications and very sensitive ECD molecular responses. Based on efficiency, convenience, worker safety, and least sample contamination, TFE esterificaiton was considered as the superior method for MCPP analysis to the other methods of derivatization. An accurate method is described for quantifying MCPP in soil leachates by GC-ECD at very low concentrations without the requirement of a complicated clean-up process. As a result, MCPP residues at concentrations of less than $0.1{\mu}g$ in 100ml soil leachate were detected.

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Effect of Phenolic Acids on Inhibition of Browning of Maillard Reaction Model Solutions (Phenolic acid가 Maillard 반응 모델액의 갈변억제에 미치는 영향)

  • Kwak, Eun-Jung;Lim, Seong-Il
    • Korean Journal of Food Science and Technology
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    • v.39 no.1
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    • pp.20-24
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    • 2007
  • The effects of phenolic acids on inhibition of browning by the Maillard reaction were investigated with a glucose-glutamic acid model for doenjang with citric acid as the antibrowning agent and phenolic acid as its synergist. Five phenolic acids, cinnamic, coumaric, caffeic, hydroxybenzoic, and protocatechuic acids, were used. In order to investigate the antibrowning capacity, 0.1M glucose, 0.1M glutamic acid, 50mM citric acid, and 1mM phenolic acid were dissolved in 1M phosphate buffer (pH 7.0), heated at $50^{\circ}C$ for 24hr in the presence of 0.2mM $FeCl_{2}$, and stored at $4^{\circ}C$ or $30^{\circ}C$ for four weeks. Phenolic acid addition more efficiently inhibited browning during storage at $30^{\circ}C$ than at $4^{\circ}C$, without changes in pH. Hydroxybenzoic acid was the most efficient and increased the antibrowning capacity by 13% compared to sample without phenolic acids. Although caffeic and protocatechuic acids inhibited most the formation of 3-deoxyglucosone or fluorescence, they increased browning by forming colored complexes between two hydroxy groups of phenolic acids and iron ions. Hydroxybenzoic acid will be able to be a useful synergist of citric acid, an antibrowning agent in doenjang, since it is permitted for doenjang.

A Study for Mechanism and Oxidation Reaction of Substituted Benzyl Alcohols by 2,2'-Bipyridinium Chlorochromate (2,2'-Bipyridinium Chlorochromate에 의한 치환 벤질 알코올류의 산화반응과 메카니즘에 관한 연구)

  • Kim, Young-Sik;Park, Young-Cho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.3252-3260
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    • 2012
  • 2,2'-Bipyridinium chlorochromate[$C_{10}H_8N_2HCrO_3Cl$] was synthesized by the reaction of 2,2'- bipyridine with chromium(VI) trioxide in 6M HCl. The structure was characterized by IR and ICP analysis. The oxidation of benzyl alcohol using 2,2'-bipyridinium chlorochromate in various solvents showed that the reactivity increased with the increase in the order of the dielectric constant(${\varepsilon}$), in the order: cyclohexene< chloroform$p-CH_3$, H, m-Br, $m-NO_2$) in N,N'-dimethylformamide. Electron-donating substituents accelerated the reaction, whereas electron acceptor groups retarded the reaction. The Hammett reaction constant(${\rho}$) was -0.64(303K). The oxidation reactivity of alcohols can be a useful factor to study about physical properties such as thermal stability, when the polysilsesquioxane solution is ready for an applying coating agent. The observed experimental data was used to rationalized the hydride ion transfer in the rate-determining step.