• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.2922-2928
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• 2014

To investigate the possible isosteric replacement of imidazolidinone moiety in 4-phenyl-1-arylsulfonylimidazolidinones (2) for broad and potent anti-cancer agents, a series of 5-phenyl-1H-pyrazol-3-yl 1-(acyl)indoline-5-sulfonates (4) and 1-(1-(acyl)indolin-5-ylsulfonyl)-5-phenylpyrazolidin-3-ones (5) were prepared and evaluated for their cytotoxicity against six human cancer cell lines. Although the pyrazoles 4 or pyrazolidinones 5 showed relatively good activity, still they showed lesser activity in comparison to imidazolidinones 2. These activity decreases could be interpreted with the effect of change of the hydrogen bonding characteristics and the substitution pattern on structural variations of five membered rings from imidazolidinones 2 to pyrazoles 4 and pyrazolidinones 5, respectively. Therefore, it can be concluded that 4-phenyl-1-arylsulfonylimidazolidinone is a basic pharmacophore of imidazolidinones 2.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.218-224
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• 2013

The aldo-keto reductases catalyze reduction reactions using various aliphatic and aromatic aldehydes/ketones. Most reductases require NADPH exclusively as their cofactors. However, NADPH is much more expensive and unstable than NADH. In this study, we attempted to change the five amino acid residues that interact with the 2'-phosphate group of the adenosine ribose of NADPH. These residues were selected based on a docking model of the YOL151W reductase and were substituted with other amino acids to develop NADH-utilizing enzymes. Ten mutants were constructed by site-directed mutagenesis and expressed in Escherichia coli. Among them, four mutants showed higher reductase activities than wild-type when using the NADH cofactor. Analysis of the kinetic parameters for the wild type and mutants indicated that the $k_{cat}/K_{m}$ value of the Asn9Glu mutant toward NADH increased 3-fold. A docking model was used to show that the carboxyl group of Glu 9 of the mutant formed an additional hydrogen bond with the 2'-hydroxyl group of adenosine ribose. The Asn9Glu mutant was able to produce (R)-ethyl-4-chloro-3-hydroxyl butanoate rapidly when using the NADH regeneration system.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2723-2728
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• 2009

The conformational properties of oligosaccharides are important to understand carbohydrate-protein interactions. A trimannoside, methyl 3,6-di-O-($\alpha$-D-Man)-$\alpha$-D-Man (TRIMAN) is a basic unit of N-linked oligosaccharides. This TRIMAN moiety was further modified by GlcNAc (BISECT), which is important to biological activity of N-glycan. To characterize the trimannoside and its bisecting one we performed a molecular dynamics simulation in water. The resulting models show the conformational transition with two major and minor conformations. The major conformational transition results from the $\omega$ angle transition; another minor transition is due to the $\psi$ angle transition of $\alpha$ (1 $\rightarrow$ 6) linkage. The introduction of bisecting GlcNAc on TRIMAN made the different population of the major and minor conformations of the TRIMAN moiety. Omega ($\omega$) angle distribution is largely changed and the population of gt conformation is increased in BISECT oligosaccharide. The inter-residue hydrogen bonds and water bridges via bisecting GlcNAc residue make alterations on the local and overall conformation of TRIMAN moiety. These changes of conformational distribution for TRIMAN moiety can affect the overall conformation of N-glycan and the biological activity of glycoprotein.

• 신재생에너지
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• 제17권1호
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• pp.40-49
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• 2021

In this study, the optical properties, heat transfer capabilities and chemical reaction performance of a methane thermal decomposition reactor using solar heat as a heat source were numerically analyzed on the basis of the cavity shape. The optical properties were analyzed using TracePro, a Monte Carlo ray tracing-based program, and the heat transfer analysis was performed using Fluent, a CFD program. An indirect heating tubular reactor was rotated at a constant speed to prevent damage by the heat source in the solar furnace. The inside of the reactor was filled with a porous catalyst for methane decomposition, and the outside was insulated to reduce heat loss. The performance of the reactor, based on cavity shape, was calculated when solar heat was concentrated on the reactor surface and methane was supplied into the reactor in an environment with a solar irradiance of 700 W/㎡, a wind speed of 1 m/s, and an outdoor temperature of 25℃. Thus, it was confirmed that the heat loss of the full-cavity model decreased to 13% and the methane conversion rate increased by 33.5% when compared to the semi-cavity model.

• Mycobiology
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• 제50권5호
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• pp.345-356
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• 2022

The fungal distribution, diversity, and load were analyzed in the geographically segregated island groundwater systems in Korea. A total of 79 fungal isolates were secured from seven islands and identified based on the internal transcribed spacer (ITS) sequences. They belonged to three phyla (Ascomycota, Basidiomycota, and Chlorophyta), five classes, sixteen orders, twenty-two families, and thirty-one genera. The dominant phylum was Ascomycota (91.1%), with most fungi belonging to the Cladosporium (21.5%), Aspergillus (15.2%), and Stachybotrys (8.9%) genera. Cladosporium showed higher dominance and diversity, being widely distributed throughout the geographically segregated groundwater systems. Based on the diversity indices, the genera richness (4.821) and diversity (2.550) were the highest in the groundwater system of the largest scale. As turbidity (0.064-0.462) increased, the overall fungal count increased and the residual chlorine (0.089-0.308) had low relevance compared with the total count and fungal diversity. Cladosporium showed normal mycelial growth in de-chlorinated sterilized samples. Overall, if turbidity increases under higher fungal diversity, bio-deterioration in groundwater-supplying facilities and public health problems could be intensified, regardless of chlorine treatment. In addition to fungal indicators and analyzing methods, physical hydrostatic treatment is necessary for monitoring and controlling fungal contamination.

• 대한기계학회논문집A
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• 제34권7호
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• pp.829-835
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• 2010

본 연구에서는 미세유체소자의 전원소자로 적용하기 위한 일회용 수소발생소자와 튜브형 고분자전해질 연료전지로 구성된 일회용 전원소자에 관한 것이다. 튜브형 고분자전해질 연료전지는 1.52 mm의 직경을 가지며, 수소발생소자는 알루미늄과 5M 수산화나트륨의 반응을 통해 수소를 발생시켜 튜브형 고분자전해질 연료전지로 공급하게 된다. 단위 튜브형 고분자전해질 연료전지는 순수한 수소에 대해여 0.81V 의 개방전압과 0.35V에서 $16.4\;mW/cm^2$의 최대전력밀도를 나타내었으며, 수소발생기는 15 분 동안 $11.6\;m{\ell}$의 수소를 생성하였다. 튜브형 고분자전해질 연료전지와 수소발생기가 결합된 일회용 전원소자는 아무런 주변장치 없이 10 분 동안 1.06 mW (0.46V)의 일정한 전력을 발생하였으며, 3 개가 직렬로 연결된 고분자전해질 연료전지는 10 분 동안 LED(2.5 mW@1.8V)를 동작시켰다.

• 대한수의학회지
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• 제44권3호
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• pp.475-482
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• 2004

For the induction of arthropathy, 4% hydrogen peroxide ($H_2O_2$) was injected for 4 weeks into the intra-articular space of the 25 New Zealand white rabbits to damage articular cartilage. The verification of arthropathy induction and the effect of scan-bio laser treatment were determined by measuring superoxide dismutase (SOD) activity, by observing gross and histopathologic findings. The SOD activity increased by about 40% in arthropathy group, as compared to controls. Although SOD activity in arthropathy group was not significantly different from the 2-week group, it was significantly different from the 4-week control and treatment groups. There was also a significant difference between the 4-week control and treatment groups. Grossly, erosions formed on the articular cartilage surface, and the lateral femoral condyle was damaged in arthropathy group. In comparison, there was slight, but not significant, progression of the lesion in the 2-week control group, and no difference between the 2-week treatment and control groups. Conversely, severe erosions damaged the articular cartilage in the 4-week control group. Cartilage proliferation was seen in gross observations in the 4-week treatment group, suggesting a treatment effect. Histopathologically, there was slight articular surface damage and apoptosis in arthropathy group, and serious cartilage damage, despite slight chondrocyte proliferation, in the 4-week control group. By contrast, the 4-week treatment group showed chondrocyte replacement, with close to normal articular cartilage on the articular surface. There was significant cartilage proliferation with regeneration of the articular cartilage on the articular surface in the group treated with low-level laser, as compared to control group, when arthropathy was induced by $H_2O_2$ injections. Therefore, low-level laser was effective in the treatment of chemically induced arthropathy.

• 유기물자원화
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• 제26권1호
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• pp.55-64
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• 2018

본 연구는 유기성폐자원(가축분뇨, 음식물류폐기물, 음식물류폐수 등)의 바이오가스 이용에 대한 적정 설계 및 운전 기술지침서 마련하고자 현장조사와 정밀모니터링 등을 실시하였다. 정부의 중장기 바이오가스화 정책에 따라 폐자원의 자원화 시설 확충이 활발히 추진되고 있다. 하지만 생산된 바이오가스를 이용하여 발전 및 스팀으로 활용하는 시설은 효율이 아직은 저조하고 잦은 고장이 발생되고 있다. 현재 운영 중인 바이오가스화 11개소를 대상으로 바이오가스 이용 공정별 특징 및 문제점을 분석하고 혐기소화조 현장 시료의 계절별 정밀모니터링을 실시하여 바이오가스 이용 공정 흐름에 따른 설계 운영 가이드라인을 제시하였다. 현장조사 수행 결과, 바이오가스 이용 공정에서 바이오가스의 적정 제습, 황화수소 전처리, 발전시설의 적정처리 등이 주요 문제점으로 조사되었다. 따라서 유기성폐자원의 바이오가스화 시설의 단점을 보완하고 바이오가스 이용 최적화 방안을 마련하기 위하여 현장지설에 대한 정밀조사를 실시하여 공정별 문제점들을 정리하였다.

• 한국미생물·생명공학회지
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• 제42권3호
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• pp.275-284
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• 2014

본 연구에서는 식물자원으로부터 생리활성을 보유한 새로운 기능성 소재를 찾고자 하였다. 이를 위해 수종의 중국 자생 식물을 분석하여 강한 항산화능을 보유한 3종(Malus hupehensis, Ophiorrhiza cantonensis, 그리고 Psychotria rubra)을 선별하고, 각 추출물의 항산화능과 항염증 생리활성을 분석하였다. 먼저 각 추출물의 항산화능을 DPPH radical 소거능을 통해 분석한 결과 모두 양성 대조군으로 사용한 ascorbic acid와 유사한 정도의 높은 활성을 보여 각 소재가 매우 강한 항산화능을 보유함을 확인하였다. 또한 RAW 264.7 세포주에서 $H_2O_2$ 및 LPS에 의해 유도된 ROS에 대한 각 추출물의 소거능을 분석한 결과에서도 농도의존적인 강한 소거능을 보였다. 뿐만 아니라 대표적인 항산화효소 중 하나로 항산화능 보유 천연물에 의해 발현이 유도되는 HO-1 및 그 전사 인자인 Nrf-2의 단백질 발현이 각 추출물의 처리에 의해 증가됨을 보였다. 한편 각 소재가 LPS에 의해 유도된 NO 생성에 미치는 영향을 분석한 결과 모두 농도의존적인 NO 생성 저해능을 보였으며 이는 NO 생성 단백질인 iNOS의 발현 저해에서 기인함을 확인하였다. 이와 같은 각 소재의 NO 생성 및 iNOS 발현 억제 효과는 염증 상위신호 전달계인 NF-${\kappa}B$ 및 AP-1의 조절을 통해 일어날 가능성을 보였다. 이러한 결과를 통해 중국 자생 식물 3종의 높은 항산화능과 항염증 활성을 처음으로 확인하였으며 향후 기능성 소재로서 유용하게 활용될 수 있을 것으로 판단된다.

• 한국미생물·생명공학회지
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• 제42권2호
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• pp.170-176
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• 2014

본 연구에서는 Euptelea pleiosperma 에탄올 추출물(EPEE)의 항산화능과 항염증 생리활성을 in vitro assay system 및 cell culture model system을 이용하여 분석하였다. 먼저 EPEE의 항산화능을 DPPH radical scavenging activity로 분석한 결과 radical 소거능의 정도가 양성 대조군으로 사용한 ascorbic acid 보다 높은 활성을 보여 매우 강한 항산화능을 보유함을 확인하였다. 또한 RAW 264.7 세포주를 이용한 $H_2O_2$ 및 LPS의 유도에 의해 생성된 ROS에 대한 소거능을 분석한 결과에서도 농도의존적인 강한 소거능을 보였다. 뿐만 아니라 대표적인 항산화효소 중 하나로 천연물에 의한 항산화능 활성에 의해 주로 발현이 유도되는 hemeoxygenase 1 (HO-1) 및 그 전사 인자인 nuclear factor-E2-related factor 2 (Nrf2)의 단백질 발현이 EPEE의 처리에 의해 유의적으로 증가됨을 보였으며 이러한 HO-1 및 Nrf2의 발현 변화는 상위신호전달계인 MAPKs 및 PI3K/Akt 에 의해 조절될 가능성을 보였다. 한편 EPEE가 LPS에 의해 유도된 NO 생성에 미치는 영향을 분석한 결과 농도의존적인 NO 생성 저해능을 보였으며 이는 NO 생성 단백질인 iNOS의 발현 저해에서 기인함을 확인하였다. 이와 같은 EPEE의 NO 생성 억제 효과는 염증 상위신호전달계인 NF-${\kappa}B$ 및 AP-1의 조절을 통해 일어날 가능성을 보였다. 이러한 결과를 통해 EPEE의 높은 항산화능과 항염증 활성을 처음으로 확인하였으며 향후 기능성 소재로서 유용하게 활용될 수 있을 것으로 판단된다.