• 대한환경공학회지
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• 제27권8호
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• pp.822-828
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• 2005

본 연구에서는 대표적인 유기인계 농약인 parathion을 대상으로 태양광의 조사 하에 $TiO_2$ 광촉매반응과 광반응에 의한 처리를 수행하였다. 실험의 결과 $TiO_2$ 광촉매반응이 광반응과 $TiO_2$ 흡착 조건에 비하여 효과적으로 parathion을 제거시켰다. 10 mg/L의 parathion은 90분 이내에 광촉매 반응으로 완전히 제거되었으며 반응시간 150분 후에 TOC는 약 63% 정도 감소되었다. 광촉매 반응에 의한 parathion의 분해에 따라, 질소 형태의 이온 부산물은 ${NO_2}^-$, ${NO_3}^-$, 그리고 ${NH_4}^+$가 발견이 되었고, 황은 ${SO_4}^{2-}$로 약 80%, 그리고 인은 ${PO_4}^{3-}$로 5% 이하로 회수되었다. 또한 parathion의 분해시 유기중간 생성물은 paraoxon과 4-nitrophenol 등이 측정되었으며, 이들 부산물들은 반응이 진행되어 가며 계속 분해됨을 보였다. 광촉매 반응과 광반응에 의하여 처리된 용액의 독성의 감소를 평가하기 위하여 두 가지 생물종인 V. fischeri와 D. magna를 이용하여 처리수의 급성 독성의 감소를 알아보았다. 두 가지 생물종 모두 광촉매반응 조건에서는 처리수의 상대독성이 초기에 비해 반응시간 150분 후에 거의 모두 감소되었고, 광반응 조건에서는 V. fischeri와 D. magna 각각에 대해서 76%와 57%의 상대독성 감소가 관찰되었다. Parathion과 TOC의 감소와 급성독성의 저감양상은 유사한 경향을 보였다.

• 대한화장품학회지
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• 제42권3호
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• pp.211-216
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• 2016

소핵시험은 세포분열 단계 중 간기 세포의 세포질 내 소핵 유무를 조사함으로써 유전독성을 평가하는 시험법이다. 최근 화장품 안전성 평가에 동물실험을 금지하거나 최소화하려는 노력이 확산되고 있어 유전독성 평가에 있어서도 기존의 동물실험이 아닌 새로운 in vitro 시험법이 요구되고 있다. 본 연구에서는 3차원 배양인공피부모델인 KeraSkin$^{TM}$을 이용하여 도포 처치된 물질의 유전독성을 평가하였다. 2종의 유전독성물질인 mitomycin C (MMC)와 methyl methanesulfonate (MMS)는 농도 의존적으로 세포독성과 소핵 형성이 유도된 반면, 대조물질인 4-nitrophenol (4-NP)와 trichloroethylene (TCE)에서는 농도 의존적으로 세포독성은 관찰되었으나 소핵은 형성되지 않았다. 따라서 인공피부모델을 이용한 소핵시험이 화장품과 같은 피부적용물질의 in vitro 유전독성 평가에 유용할 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.307-311
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• 2000

Abstract Extracellular chitinase was purified from the culture liquid of the marine bacterium, Bacillus sp. LJ-25 , and its enzymatic properties were examined. The purified chitinase exhibited a single band on SDS-PAGE and the molecular weight was estimated to be approximately 50 kDa. The optimum pH and temperature for the enzymatic activity were 7.0 and $35^{\circ}C$, respectively. The activity of the chitinase was strongly inhibited by $Zn^{2+}$ and slightly inhibited by $Ba^{2+},{\;}Co^{2+},{\;}Mn^{2+},{\;}and{\;}Cu^{2+}$. The purified chitinase did not hydrolyze $p-nitrophenolN-acetyl-{\bata}-D-glucosaminide{\;}(GlcNAc)_2$ and Micrococcus lysodeikticus cells, which are known to be the substrates for exo-type chitinase. Among the hydrolyzates of colloidal chitin, $(GlcNAc)_2$ was in the highest concentration with small amounts of GlcNAc and $(GlcNAc)_3$..

• Carbon letters
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• 제12권3호
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• pp.152-161
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• 2011

Activated carbon was prepared from pre-carbonized petroleum coke. Textural properties were determined from studies of the adsorption of nitrogen at 77 K and the surface chemistry was obtained using the Fourier-transform infrared spectrometer technique and the Boehm titration process. The adsorption of three aromatic compounds, namely phenol (P), p-nitrophenol (PNP) and benzoic acid (BA) onto APC in aqueous solution was studied in a batch system with respect to contact time, pH, initial concentration of solutes and temperature. Active carbon APC obtained was found to possess a high surface area and a predominantly microporous structure; it also had an acidic surface character. The experimental data fitted the pseudo-second-order kinetic model well; also, the intraparticle diffusion was the only controlling process in determining the adsorption of the three pollutants investigated. The adsorption data fit well with the Langmuir and Freundlich models. The uptake of the three pollutants was found to be strongly dependent on the pH value and the temperature of the solution. Most of the experiments were conducted at pH 7; the $pH_{(PZC)}$ of the active carbon under study was 5.0; the surface of the active carbon was negatively charged. The thermodynamic parameters evaluated for APC revealed that the adsorption of P was spontaneous and exothermic in nature, while PNP and BA showed no-spontaneity of the adsorption process and that process was endothermic in nature.

• Journal of Microbiology and Biotechnology
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• 제7권4호
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• pp.250-257
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• 1997

A new sensing system based on the immobilization of luminescent bacteria, photobacterium phosphoreum, was proposed for continuous real-time monitoring of pollutants. The response curves demonstrate that Photobacterium phosphoreum immobilized on the strontium alginate were very sensitive to seven reference chemicals used. The significant inhibitory concentrations for bioluminescence emission were 5 ppm for Pb$(NO_3)_2$), $NiCl_2$, $CdCl_2$, 50 ppm for $NaASO_2$, 0.1 ppm for $HgCl_2$, 0.5 ppm for pentachlorophenol and less than 5 ppm for SDS, respectively. The alginate mixed-cells (AMC) retained their luminescence during experimental period (29 days) under storage condition of $-80^{\circ}C$. The variables affecting performance of continuous flow through monitoring (CFTM) was optimized in order to ensure stability and efficiency. The flow through cell with strontium-alginate immobilized luminescent bacteria was tested with salicylate and 4-nitrophenol. A rapid response of luminescence was recorded by time drive mode in bioluminescence spectrometer after exposure to both toxicants.

• Journal of Microbiology and Biotechnology
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• 제17권11호
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• pp.1890-1893
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• 2007

A bacterium, Burkholderia sp. JBA3, which can mineralize the pesticide parathion, was isolated from an agricultural soil. The strain JBA3 hydrolyzed parathion to p-nitrophenol, which was further utilized as the carbon and energy sources. The parathion hydrolase was encoded by a gene on a plasmid that strain JBA3 harbored, and it was cloned into pUC19 as a 3.7-kbp Sau3AI fragment. The ORF2 (ophB) in the cloned fragment encoded the parathion hydrolase composed of 526 amino acids, which was expressed in E. coli DH10B. The ophB gene showed no significant sequence similarity to most of other reported parathion hydrolase genes.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.793-800
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• 2013

A few years ago, the plasmon-induced electronic coupling (PIEC) model was proposed in the literature to explain small changes in the surface-enhanced Raman scattering (SERS) in nanogap systems. If this model is correct, it will be very helpful in both basic and application fields. In light of this, we carefully reexamined its appropriateness. Poly(4-vinylpyridine) (P4VP) used in the earlier work was, however, never a proper layer, since most adsorbates not only adsorbed onto Ag nanoparticles sitting on P4VP but also penetrated into the P4VP layer deposited initially onto a flat Ag substrate, ultimately ending up in the SERS hot sites. Using 1,4-phenylenediisocyanide and 4-nitrophenol as the affixing layer and the foreign adsorbate, respectively, we could clearly reveal that the PIEC model is not suited for explaining the Raman signal in a nanogap system. Most of the Raman signal must have arisen from molecules situated at the gap center.

• Carbon letters
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• 제7권3호
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• pp.188-195
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• 2006

Phosphoric acid-activated carbon WP's and zinc chloride-activated carbons WZ's were developed from wild cherry stones. The textural properties of the activated carbons were determined from nitrogen adsorption data at 77 K and the chemistry of the carbon surface, i.e. the surface carbon-oxygen groups (type and amount) was determined from the base and acid neutralization capacities (Boehm method). The adsorption of phenol, p-nitrophenol, p-chlorophenol, dinitrophenol and dichlorophenol was followed at 298 K. The activated carbons obtained were characterized by high surface area and large pore volumes as well as by high surface concentration of C-O groups. The investigated carbons exhibited high adsorption capacities towards phenols with these capacities increased with the increase of molecular weight and the decrease of the solubility of phenol in water. However, no general relationship could be observed between the adsorption capacities of carbons and any of their textural parameters or their surface chemistry. This may be attributed to the many factors controlling phenol adsorption and the different types and mechanisms of adsorption involved.

• BMB Reports
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• 제32권1호
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• pp.98-102
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• 1999

Since carbohydrates are major mediators in cell-to-cell adhesion and communication, the development of specific and strong binders against them could generate promising therapeutics. As the first step towards that goal, sugar molecules have to be immobilized to be used as an affinity matrix. The amino functionality in sugar is the most active nucleophile for the immobilization, if the amino group is available. An alternative and general method is to use the hydroxyl group as a direct nucleophile, but the quantitation of immobilized hydroxyl groups is not easily done. To overcome this limitation, we have developed a method to immobilize various isomers of monosaccharides with p-nitrophenyl groups to the beads by using their hydroxyl groups. It was found that the amount of immobilized sugar was independent of the structure of the sugar, but was dependent on the number of hydroxyl groups. We also developed a sensitive method to quantify the amount of immobilized sugar at the picomolar scale by utilizing commercially available glycosidases to release a sensitive reporter molecule, p-nitrophenol, and detect it by HPLC. This new technique would allow a facile quantitation method for immobilized sugar molecules, which could be used as the affinity matrix to develop strong binders against biologically important sugars.

• BMB Reports
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• 제30권4호
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• pp.237-239
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• 1997

The effects of trichloroethylene (TRI) on the induction of cytochrome P-450 (CYP) and several other related enzymes in Sprague Dawley rats were investigated Rats were treated with TRI 150. 300. 600 mg/kg body weight in corn oil intra peritoneally once a day for 2 days. The total contents of microsomal CYP and cytochrome $b_5\;(b_5)$ decreased with the increase of TRI concentration. but the activity of p-nitrophenol hydroxylase increased with the increase of TRI dosage (p<0.05). Western blot analysis which utilized monoclonal antibodies against CYP2E1 also showed a significant increase in the CYP2E band density. The increase of the activity of pentoxyresolufin-O-deethylase also was observed with the TRI treatment (p<0.05) although there was no significant increase in the cytochrome CYP2B1/2 in Western blotting The TRI did not affect the induction of aryl hydrocarbon hydroxylase. These findings suggest that the CYP2E1 is the primary enzyme which could be induced by TRI treatment in rats.