• 대한환경공학회지
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• 제39권8호
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• pp.489-493
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• 2017

미생물연료전지는 하폐수에 존재하는 다양한 유기성물질을 전기에너지로 변환시킬 수 있는 생물전기화학적공정이다. 본 연구에서는 전산모사를 통하여 산화전극의 크기, 전극간 거리, 전체 산화전극면적이 기질분해에 미치는 영향을 알아보고자 하였다. 생활하수를 처리하는 다중산화전극 및 SPA (Spaced electrode assembly)형 연속식 미생물연료전지공정을 모사하였으며, 전산모사결과에 따르면 단일전극의 크기에 의한 영향보다는 전극간 거리가 짧을수록 기질분해속도가 빠른 것으로 나타났다. 특히 전체 산화전극의 면적이 큰 경우가 기질분해가 가장 빠른 것으로 나타났다. 본 연구를 통하여 미생물연료전지공정의 설계에 있어서 율속단계로 알려진 환원전극의 크기 외에도 산화전극의 크기 및 전극간 거리 또한 기질분해 속도에 영향을 미칠 수 있는 중요한 인자임을 알 수 있었다.

• 폴리머
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• 제32권4호
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• pp.390-396
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• 2008

조직공학용 생체재료로 사용하고자 가교제 1,3-butadiene diepoxide(BD)를 사용하여 락타이드(LA)와 가교시킨 히아루론산(HA) 고분자를 제조하였다. 가교된 고분자의 락타이드 및 BD 반응도는 핵자기 공명 분광법으로 결정하였다. 반응도와 팽윤도는 LA/HA 몰비 혹은 가교제 농도를 증가시킴에 따라 증가하였다. 탄성률은 가교제 농도가 증가하거나 HA/LA 몰비가 감소함에 따라 감소하였다. 생분해는 2단계로 진행되었으며 BD 농도가 증가할수록 서서히 진행되었다. 첫 단계 분해는 주로 가교구조에 존재하는 에스테르기의 분해에 기인한 것으로 나타났다. 세포 성장 저해는 BD 농도가 증가함에 따라 증가하였다. 세포 독성은 BD 농도가 클 경우 약간 나타났으나 그 값은 6% 미만으로 세포 성장에 큰 문제는 없는 것으로 나타났다.

• Environmental Engineering Research
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• 제11권2호
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• pp.84-90
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• 2006

UV-catalytic oxidation technique was applied for the treatment of bio-refractory character of the leachate, which is generally present in the form of adsorbable organic halogens (AOX). Destruction of AOX was likely to be governed by pH adjustment, quantitative measurement of oxidants, and the selection of oxidation model type. Peroxide induced degradation ($UV/H_2O_2$) facilitated the chemical oxidation of organic halides in acidic medium, however, the system showed least AOX removal efficiency than the other two systems. Increased dosage of hydrogen peroxide (from 0.5 time to 1.0 time concentration) even did not contribute to a significant increase in the removal rate of AOX. In ozone induced degradation system ($UV/O_3$), alkaline medium (pH 10) favored the removal of AOX and the removal rate was found 11% higher than the rate at pH 3. Since efficiency of the $UV/O_3$ increases with the increase of pH, therefore, more OH-radicals were available for the destruction of organic halides. UV-light with the combination of both ozone and hydrogen peroxide ($UV/H_2O_2$ 0.5 time/$O_3$ 25 mg/min) showed the highest removal rate of AOX and the removal efficiency was found 26% higher than the removal efficiency of $UV/O_3$. The system $UV/H2O_2/O_3$ got the economic preference over the other two systems since lower dose of hydrogen peroxide and relatively shorter reaction time were found enough to get the highest AOX removal rate.

• 한국동물위생학회지
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• 제40권4호
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• pp.265-275
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• 2017

The production of enzymes that help digestion, assimilation of essential nutrients, and prevent pathogenic bacteria are important for probiotics used in aquaculture. The objective of this study was to investigate enzyme activities for macromolecular organic matters and antimicrobial properties of the selected potential probiotics isolated from gut of surf clam (Tresus keenae) against well-known shellfish-pathogenic bacteria. Among 65 isolates from guts of 60 surf clams, seven Bacillus strains with outstanding degradation capability of macromolecule organic matter were selected as potential probiotics as follows: TKI01 (B. vietnamensis), TKI02, TKI26 (B. thuringiensis), TKI14, TKI32, TKI42 (B. amyloliquefaciens), and TKI18 (B. stratosphericus). After in vitro antimicrobial activity test was performed against five shellfish-pathogenic bacteria including Listonella anguillarum, Vibrio parahaemolyticus, V. splendidus, V. harveyi, V. tubiashii, PCR assay was performed to detect bacteriocin-producing strain. PCR results revealed that the five Bacillus strains possessed diverse bacteriocin genes including ericinA, coagulin, surfactin, iturin, bacyllomicin, fengycin, bacylisin, subtilin, and lantibiotics. In the present study, the selected seven Bacillus strains showed different enzyme activities according to types of macromolecule organic matters. And their antimicrobial activities varied based on the species of pathogenic bacteria. In addition, at least five Bacillus strains had genetic potential to produce several natural lipopeptide antibiotics that may help biological control of surf clam aquaculture. Therefore, mixed use of probiotics might show co-operative effect and increase the efficiency of probiotics rather than separate use. To the best of our knowledge, it is the first report on antimicrobial properties of Bacillus species isolated from surf clam.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2004-2008
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• 2014

This paper reports the facile synthesis methods of zinc oxide (ZnO) nanoparticles, Z1-Z10, using diethylene glycol (DEG) and polyethylene glycol (PEG400). The particle size and morphology were correlated with the PEG concentration and reaction time. With 0.75 mL of PEG400 in 150 mL of DEG and a 20 h reaction time, the ZnO nanoparticles began to disperse from a collective spherical grain shape. The ZnO nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and a $N_2$ adsorption-desorption studies. The Brunauer-Emmett-Teller (BET) surface areas of Z4, Z5 and Z10 were 157.083, 141.559 and 233.249 $m^2/g$, respectively. The observed pore diameters of Z4, Z5 and Z10 were 63.4, 42.0 and 134.0 ${\AA}$, respectively. The pore volumes of Z4, Z5 and Z10 were 0.249, 0.148 and 0.781 $cm^3/g$, respectively. The photocatalytic activity of the synthesized ZnO nanoparticles was evaluated by methylene blue (MB) degradation, and the activity showed a good correlation with the $N_2$ adsorption-desorption data.

• 대한수의학회지
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• 제49권1호
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• pp.1-8
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• 2009

The ubiquitin-proteasome mediated protein degradation pathway plays an important role in regulating both cell proliferation and cell death. Proteasome inhibitors are well known to induce apoptosis in various human cancer cell lines. We investigated the effect of combined treatment with proteasome inhibitor and TRAIL, and a possible mechanism of the enhancing apoptosis by the both treatment, on TRAIL-resistant non-small cell lung cancer. A549 cells were exposed to the N-Acetyl-Leu-Leu-Norleu-al (ALLN) as a proteasome inhibitor and then treated with recombinant TRAIL protein. In A549 cells under proteasome inhibition conditions by pretreatment with ALLN, TRAIL treatment significantly decreased cell viability compared to that ALLN and TRAIL alone treatment. Also, the both treatment induced cell damage through DNA fragmentation and p53 expression. In addition, the combined treatment of both markedly increased caspase-8 activation, especially the exposure for 2 h, and Bax expression and induced the dissipation of mitochondrial transmembrane potential in A549 cells. Taken together, these findings showed that proteasome inhibition by ALLN enhanced TRAIL-induced apoptosis via DNA degradation by activated P53 and mitochondrial transmembrane potential loss by caspase-8 activation and bax expression. Therefore, our results suggest that proteasome inhibitor may be used a very effectively chemotherapeutic agent for the tumor treatment, especially TRAIL-resistant tumor cell.

• 한국자원식물학회지
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• 제30권3호
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• pp.272-279
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• 2017

EP was obtained through 20% ethanol extraction of Pueraria lobata root, and the fermented form of EP, FEP, was prepared from the EP after incubating with Lactobacillus rhamnosus vitaP1. There was no significant toxicity by EP and FEP up to $1000{\mu}g/ml$ in NIH-3T3, HaCaT, and B16F10 cells. In addition to antioxidant potentials of EP and FEP determined by DPPH and ABST assays, we confirmed increase of procollagen type I and elastin synthesis by supplementation of the EP and FEP at the concentration of $50{\mu}g/ml$ using ELISA kits. The protein expression levels of matrix metalloprotease (MMP)-1, -3, and -9, those are involved in the degradation of collagen or other skin matrix proteins, were remarkably suppressed while their inhibitory protein metallopeptidase inhibitor 1 (TIMP-1) was greatly up-regulated by supplementation of the EP and FEP at a concentration of $50{\mu}g/ml$. Taken together, both EP and FEP supplementation could be involved in the suppression of the skin wrinkle formation through inhibiting degradation of collagen and stimulating the synthesis of collagen and elastin. The results showed that the anti-wrinkle potential of the EP and FEP will be a promising candidate for developing cosmeceutical compounds or products.

• 한국미생물·생명공학회지
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• 제42권1호
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• pp.89-92
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• 2014

Wnt/${\beta}$-catenin 신호전달체계는 세포 증식, 분화, 그리고 기관 발생과 같은 다양한 생명현상에 중요한 역할을 한다. 본 연구에서는 세포기반 스크리닝 기법을 사용하여 Wnt/${\beta}$-catenin 신호전달체계를 저해하는 bryostatin-1을 발굴하였다. Bryostain 1은 ${\beta}$-catenin의 mRNA 수준에는 영향을 미치지 않는 반면 세포 내 ${\beta}$-catenin 단백질 수준을 감소시킴으로 Wnt3a-CM에 의해 활성화 된 ${\beta}$-catenin response transcription (CRT)을 억제하였다. 또한 프로테아좀의 활성을 저해하였을 경우 bryostatin-1에 의한 ${\beta}$-catenin 수준 감소가 억제되었다. 본 연구의 결과들로부터 bryostatin-1이 프로테아좀에 의한 ${\beta}$-catenin 단백질 분해를 촉진함으로써 Wnt/${\beta}$-catenin 신호전달체계를 저해함을 확인하였다.

• 생물환경조절학회지
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• 제2권1호
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• pp.16-26
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• 1993

A sundry system is one of popular systems for composting livestock manure, of which main honest is to utilize unlimited, clean, and free solar radiation. A sundry system with a composter of two horizontal screw-type concrete ducts at different height, was constructed and operated for three days for each test in May, 1993, to evaluate its composting performance. Four treatments of the mixture ratio of swine manure and saw dust (manure : sawdust= 1 : 1.25, 1 : 1, 1 : 0.7, 1 : 0.5) were implemented to evaluate the effect of the mixture ratio on degradation of the composting materials of a sundry system with a screw-type composter. Maximum temperature of the composting materials was over 5$0^{\circ}C$ at D1 or D2 (one or two days after operation starts) for each test. Mean C/N ratio and water contents of the materials were reduced by more than 15 and 20％, respectively. Microbial density of each test showed a typical variation with the lapse of the composting time. Mesophilic microorganism seemed to play more important role on degradation of the materials than thermophilic. A sundry system with a screw-type composter can be considered as a feasible system on basis of maturity data. The conclusion was completely reverse from that of Choi et at., although both adopted a sundry system. A further study is recommended to pursue the cause of better performance of the screw-type composter, whether it was due to affirmative weather or more efficient composter.

• Biomolecules & Therapeutics
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• 제23권4호
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• pp.339-344
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• 2015

Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. However, more detailed mechanism by which NAR exerts anti-cancer properties still remains unanswered. Thus, in this study, we have shown that NAR down-regulates the level of cyclin D1 in human colorectal cancer cell lines, HCT116 and SW480. NAR inhibited the cell proliferation in HCT116 and SW480 cells and decreased the level of cyclin D1 protein. Inhibition of proteasomal degradation by MG132 blocked NAR-mediated cyclin D1 downregulation and the half-life of cyclin D1 was decreased in the cells treated with NAR. In addition, NAR increased the phosphorylation of cyclin D1 at threonine-286 and a point mutation of threonine-286 to alanine blocked cyclin D1 downregulation by NAR. p38 inactivation attenuated cyclin D1 downregulation by NAR. From these results, we suggest that NAR-mediated cyclin D1 downregulation may result from proteasomal degradation through p38 activation. The current study provides new mechanistic link between NAR, cyclin D1 downregulation and cell growth in human colorectal cancer cells.