• 한국환경과학회지
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• 제13권3호
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• pp.245-250
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• 2004

The SBR(Sequencing Batch Reactor) process is ideally suited to treat high loading wastewater due to its high dilution rate. SBR operates by a cycle of periods consisting of filling, reacting, settling, decanting and idling. The react phases such as aeration or non-aeration, organic oxidation, nitrification, denitrification and other bio-logical reactions can be achieved in a reactor. Although the whole reactions can be achieved in a SBR with time distributing, it is hard to manage the SBR as a normal condition without recognizing a present state. The present state can be observed with nutrient sensors such as ${NH_{4}}^{+}-N$, ${NO_{2}}^{-}-N$, ${NO_{3}}^{-}-N} and ${PO_{4}}^{ 3-}-P.$ However, there is still a disadvantage to use the nutrient sensors because of their high expense and inconvenience to manage. Therefore, it is very useful to use common on-line sensors such as DO, ORP and pH, which are less expensive and more convient. Moreover, the present states and unexpected changes of SBR might be predicted by using of them. This study was conducted to get basic materials for making an inference of SBR process from ORP(oxidation reduction potential) of synthetic wastewater. The profiles of ORP, DO, and pH were under normal nitrification and denitrification were obtained to compare abnormal condition. And also, nitrite and nitrate accumulation were investigated during reaction of SBR. The bending point on ORP profile was not entirely in the low COD/NOx ratio condition. In this case, NOx was not entirely removed, and minimum ORP value was presented over -300mV. Under suitable COD/NOx ratio which complete denitrification was achieved, ORP bending point was observed and minimum ORP value was under -300m V. Under high COD/NOx ratio, ORP bending point was not detected at the first subcycle because of the fast denitrification and minimum ORP value was under -300mV at the time.

• 한국미생물·생명공학회지
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• 제41권2호
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• pp.215-220
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• 2013

Tobermolite, perlite 및 polyurethane을 충전재로 이용한 바이오필터에 의한 메탄제거 기술이 개발되고 있다. 본 연구에서는 이들 충전재가 메탄산화능에 미치는 영향을 알아보았다. 습지토양과 매립지토양에서 분리한 혼합 메탄산화세균(consortium A, B, C and D)를 접종원으로 하고, 메탄산화속도와 메탄산화세균 수에 미치는 담체(perlite, tobermolite,polyurethane)의 영향을 조사하였다. Perlite를 첨가한 경우 메탄산화속도는 대조군 (담체 미첨가)보다 두 배 이상 증가하였고, 메탄산화세균 수도 10배 이상 증가하였다. Tobermolite를 첨가한 경우에는 일반세균 수 대비 메탄산화세균의 비율이 대조군과 다른 담체에 비해 높았다. 이는 tobermolite가 메탄산화세균이 우점할 수 있는 특이적 담체로 작용함을 시사한다. 이상의 결과로 부터 perlite와 tobermolite는 메탄산화세균의 활성을 증가시키는 서식지를 제공하며 메탄산화 공정시스템에 적용 시 좋은 담체의 역할을 할 수 있을 것으로 기대된다.

• KSBB Journal
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• 제29권4호
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• pp.244-249
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• 2014

Biosynthesis pathway of medium-chain-length (MCL) polyhydroxyalkanoates (PHA) from fatty acid ${\beta}$-oxidation pathway was constructed in recombinant Escherichia coli by introducing the Pseudomonas sp. 61-3 PHA synthase gene (phaC2) and the maoC genes from Pseudomonas putida, Sinorhizobium meliloti, and Ralstonia eutropha. The metabolic link between fatty acid ${\beta}$-oxidation pathway and PHA biosynthesis pathway was constructed by MaoC, which is homologous to P. aeruginosa (R)-specific enoyl-CoA hydratase (PhaJ1). When the E. coli W3110 strains expressing the phaC2 gene and one of the maoC genes from P. putida, Sinorhizobium meliloti, and Ralstonia eutropha were cultured in LB medium containing 2 g/L of sodium decanoate as a carbon source, MCL-PHA that mainly consists of 3-hydroxyhexanoate (3HHx), 3-hydroxyoctanoate (3HO) and 3-hydroxydecanoate (3HD), was produced. The monomer composition of PHA and PHA contents varied depending on MaoC employed for the production of PHA. The highest PHA content of 18.7 wt% was achieved in recombinant E. coli W3110 expressing the phaC2 gene and the P. putida maoC gene. These results suggest that MCL-PHA biosynthesis pathway can be constructed in recombinant E. coli strains from the b-oxidation pathway by employing MaoC able to supply (R)-3-hydroxyacyl-CoA, the substrate of PHA synthase.

• 한국미생물·생명공학회지
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• 제41권4호
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• pp.433-441
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• 2013

본 연구에서는 Endlicheria anomala (Nees) Mez 메탄올 추출물(EAME)의 항산화, 항염증 및 미백 생리활성을 in vitro assay 및 cell culture model system을 이용하여 분석하였다. EAME의 항산화능을 분석한 결과 DPPH, $H_2O_2$로 유도한 ROS, LPS로 유도한 NO 등 다양한 산화적 스트레스원을 효과적으로 소거하였다. 대표적인 항산화 효소들로 천연물에 의한 항산화능 활성에 의해 주로 발현이 유도되는 세효소인 HO-1, TrxR1, NQO1 및 그 전사 인자인 Nrf2의 단백질 발현에 미치는 영향을 분석한 결과 시료 처리 농도의 증가에 따라 세 효소 및 Nrf2의 발현이 유의적으로 증가됨을 보였다. 또한 EAME는 in vitro DOPA oxidation을 강하게 저해하여 tyrosinase inhibitor로서 작용할 가능성을 시사하였고 이에 B16F10 melanocyte를 이용하여 미백 효능을 분석한 결과 유의적인 melanin 생성억제능 및 tyrosinase 효소 활성 억제능을 보였으며 이는 tyrosinase, TRP-1, TRP-2 등 melanin 생성의 핵심 작용 효소들의 단백질 발현 저해를 통해 일어나는 것으로 나타났다. 이러한 결과를 통해 EAME가 높은 항산화능과 항염증 활성, 그리고 미백 활성을 보유함을 처음으로 밝혔으며 향후 기능성 식품 및 피부 미용 소재로서유용하게 활용될 수 있을 것으로 판단된다.

• 상하수도학회지
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• 제22권4호
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• pp.467-473
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• 2008

Natural organic matter (NOM) removal by physico-chemical adsorption and biological oxidation was investigated in five slow sand filters with different media depths. Non-purgeable dissolved organic carbon(NPDOC) and $UV_{254}$ absorbance were measured to evaluate the characteristics of NOM removal at different filter depths. Removal efficiency of NOM was in the range of 10-40% throughout the operation time. At start-up of the filters packed with clean sand media, NOM was probably removed by physico-chemical adsorption on the surface of sand through the overall layer of filter bed. However, when Schumutzdecke layer was built up after 30 days operation, the major portion of NPDOC was removed by biological oxidation and/or bio-sorption in lower depth above 50 mm. NOM removal rate in the upper 50 mm filter bed was $0.82hr^{-1}$. It was about 20 times of the rate($0.04hr^{-1}$) in the deeper filter bed. Small portion of NPDOC could be removed in the deeper filter bed by both bio-sorption and biodegradation. SEM analysis and VSS measurement clearly showed the growth of biofilm in the deeper filter bed below 500 mm, which possibly played an important role in the NOM removal by biological activity besides the physco-chemical adsorption mechanism

• Journal of Acupuncture Research
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• 제32권3호
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• pp.117-126
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• 2015

Objectives : This study was an analysis of the anti-inflammatory, anti-oxidative and skin whitening properties of Gamioncheong-decoctione(GMOCD) extract. Methods : GMOCD(96 g) and 2 L of distilled water were heated at $100^{\circ}C$ for four hours and then concentrated, frozen, freeze-dried, dissolved in distilled water and filtered. The following analysis was completed: cell cytotoxic effect using MTT assay, oxidative products of NO by griess assay, concentration of prostaglandin $E_2(PGE_2)$ by commercially competitive enzyme immunoassay, and cytokines($IL-1{\beta}$, IL-6 and TNF-${\alpha}$) by Bio-Plex$^{(R)}$ Suspension Array System's Bio-Plex Pro$^{TM}$ mouse cytokine, chemokine, and growth factor assay. Anti-oxidative effect was measured using the DPPH method and skin whitening effect using tyrosinase inhibition assay. Results : GMOCD water-extract did not show any toxicity at all doses and cell viability was more than 90 % at all doses. GMOCD water-extract significantly inhibited NO production at doses of 100, 200, $400{\mu}g/ml$, significantly inhibited $PGE_2$ production at doses of 200 and $400{\mu}g/ml$ and reduced the LPS-induced IL-$1{\beta}$, IL-6 and TNF-${\alpha}$ production in a dose-dependent manner. $IL-1{\beta}$ production was significantly reduced at a dose of $400{\mu}g/ml$ and IL-6 production was significantly reduced at doses of 200 and $400{\mu}g/ml$. DPPH free radical scavenging capability had a skin whitening effect rate of more than 50%. Tyrosinase inhibition activity was apparent in a dose-dependent manner. Conclusions : This study suggests that GMOCD water-extract suppressed NO and $PGE_2$ production and inhibited cytokines($IL-1{\beta}$, IL-6 and TNF-${\alpha}$). GMOCD also improved DPPH free radical scavenging capability. GMOCD water-extract increased tyrosinase inhibitory activity in a dose-dependent manner but this was not a statistically significant result.

• 한국식생활문화학회지
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• 제34권5호
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• pp.645-650
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• 2019

Skin plays important roles in protecting the internal organs from the chemical-biological risk factors and ultraviolet light. Exposure to the chemical and biological stimuli has a detrimental effect on skin's structure and physiological regulation. Therefore, much attention has been paid to natural products that show biological activities such as anti-oxidation, anti-aging and anti-bacterial activities. In this study, we investigated the skin-related biological activities of Oenothera lamarckiana aerial part extract. The extract contained 229.35 mg TAE (tannic acid equivalents)/g total polyphenolic compounds and the extract showed relative high antioxidant activity ($SC_{50}$ value: $8.52{\mu}g/mL$). The $IC_{50}$ value against tyrosinase and elastase were 307.94 and $181.51{\mu}g/mL$, respectively. This suggested that O. lamarckiana can be applied to whiten skin and slow the aging of skin. O. lamarckiana extract showed a growth inhibitory effect on Staphylococcu epidermidis (minimum inhibitory concentration: $250{\mu}g/mL$). Interestingly, O. lamarckiana extract showed no inhibitory effect on Pseudomonas aeruginosa on the paper disc assay. Yet the extract inhibited the growth of Pseudomonas aeruginosa on the broth dilution assay in a dose-dependent manners. Taken together, O. lamarckiana could have good potential for development as an additive in the cosmetic industry.

• 한방안이비인후피부과학회지
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• 제32권3호
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• pp.48-57
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• 2019

Objectives : This study examined the inhibitory effects of Wisaengtang(WST) on inflammatory mediators($NF-{\kappa}B$, COX-2, iNOS, IL-6) in cellular inflammatory responses induced by lipopolysaccharide(LPS). Methods : To investigate the cytotoxicity of WST, MTT assay was used. The inhibitory effects of inflammatory mediators were confirmed by real-time PCR and DPPH scavenging activity was measured to confirm the antioxidative effect. Results : When the $NF-{\kappa}B$ mRNA expression was inhibited, the levels of COX-2, iNOS, and IL-6 mRNA in the inflammatory response decreased significantly. iNOS is involved in the production of nitric oxide (NO), and it is confirmed that WST inhibits the expression of iNOS mRNA and thus the production of NO. Conclusions : These results suggest that WST can be a therapeutic substance for oxidation and inflammation through elimination of DPPH free radical and inhibition of $NF-{\kappa}B$ activity.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.817-821
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• 2008

We have investigated the influence of the crystal structure on the chemical bonding nature and photocatalytic activity of cubic and hexagonal perovskite A[$Cr_{1/2}Ta_{1/2}$]O3 (A = Sr, Ba) compounds. According to neutron diffraction and field emission-scanning electron microscopy, the crystal structure and particle size of these compounds are strongly dependent on the nature of A-site cations. Also, it was found that the face-shared octahedra in the hexagonal phase are exclusively occupied by chromium ions, suggesting the presence of metallic (Cr-Cr) bonds. X-ray absorption and diffuse UV-vis spectroscopic analyses clearly demonstrated that, in comparison with cubic Sr[$Cr_{1/2}Ta_{1/2}$]$O_3$ phase, hexagonal Ba[$Cr_{1/2}Ta_{1/2}$]$O_3$ phase shows a decrease of Cr oxidation state as well as remarkable changes in interband Cr d-d transitions, which can be interpreted as a result of metallic (Cr-Cr) interactions. According to the test of photocatalytic activity, the present semiconducting materials have a distinct activity against the photodegradation of 4-chlorophenol. Also the Srbased compound was found to show a higher photocatalytic activity than the Ba-based one, which is attributable to its smaller particle size and its stronger absorption in visible light region.

• 청정기술
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• 제25권3호
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• pp.238-244
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• 2019

본 연구에서는 온도와 압력의 변화에 따른 석유계항공유(Jet A-1), 바이오항공유(Bio-6308) 그리고 두 항공유를 50:50 (v:v)으로 혼합한 연료의 점화특성의 변화에 대한 분석을 수행하였다. Combustion research unit (CRU) 장비를 사용하여 각 항공유의 점화지연시간을 측정하였으며, GC/MS 및 GC/FID를 사용하여 각 항공유를 구성하는 화합물에 대한 정성 및 정량적인 분석을 수행하였다. 그 결과, 모든 연료의 경우에서 온도와 압력이 증가할수록 점화지연시간이 짧게 측정 되었으며, 특히 압력보다 온도의 영향을 더 많이 받는 것을 확인하였다. 또한, 모든 측정 조건에서 Jet A-1의 점화지연시간이 가장 길게 측정되었는데 이는 Jet A-1을 약 22.48%의 비율로 구성하는 방향족화합물이 산화되는 과정에서 생성되는 benzyl radical이 구조적으로 매우 안정한 특성을 갖기 때문인 것으로 판단되었다. 이러한 benzyl radical은 negative temperature coefficient (NTC) 구간에 영향을 줄 수 있는 반응을 억제하여, Jet A-1의 경우에서는 온도가 증가함에 따라 점화지연시간이 짧아지는 정도가 감소하는 구간이 없는 것을 확인하였다. Jet A-1과 Bio-6308을 50:50 (v:v)으로 혼합한 연료의 점화특성은 Bio-6308 보다는 Jet A-1과 비슷한 경향을 나타내는 것을 통해 기존의 시스템을 변경하지 않고서도 실제로 적용이 가능함을 확인하였다.