• 한국환경보건학회지
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• 제24권3호
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• pp.63-69
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• 1998

The treatment of soils and water contaminated with MTBE using the Fenton oxidation was investigated. The effects of dosage of $H_{2}O_{2}$, and Fe$^{2+}$ concentrations, and solution pH on transformation and mineralization in soil were evaluated. Generation of TBA and acetone following Fenton-oxidation of MTBE in water and generation of acetone following Fenton-oxidation of TBA were observed. Therefore TBA and acetone are degradation intermediates of MTBE. There was a large difference of treatment efficiency in Fenton oxidation of MTBE between soil and water system. This may be caused by the complex nature of soil, soil organic matter which can consumed OH $\cdot$ radicals, and interacting with inorganic-soil constituents. The pH of soil was observed to have a significant effect on the chemical oxidation efficient of MTBE in soil The data demonstrated that optimal pH range were pH 3~4 and around 6. The soil batch studies demonstrated that treatment efficiency of MTBE was enhanced by adding additional ferrous salts but Fenton-oxidation occurred in no additional iron which indicated that iron in soil can catalyze the Fenton-oxidation. The most effective parameter of Fentonoxidation was $H_{2}O_{2}$/Fe$^{2+}$ ratio which theocratical ratio is 0.5. The optimal range of this ratio was found to be 0.6~2.3. In evaluating effect of $H_{2}O_{2}$ dosage on treatment efficiency, the increase of $H_{2}O_{2}$ did not always lead to increase of decompositions of MTBE in soil. Fenton oxidation was effective in destroying MTBE in aqueous extracts of contaminated soil and water. Experimental data provided evidence that the Fenton oxidation can effectively remediate MTBE-contaminated water and soil.

• Molecular & Cellular Toxicology
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• 제4권1호
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• pp.66-71
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• 2008

Long term exposure of Jurkat cells to 2 ATA pressure resulted in the inhibition of cell growth. Under a 2 ATA pressure, the morphological changes in the cells were visualized by electron microscopy. The cells exhibited significant inhibitory responses after three passages. However, short-term exposure study was carried out, 2 ATA pressure may have beneficial effects. The Jurkat cells were exposed to $H_2O_2$ (25 and $50{\mu}M$) in order to induce DNA damage, and then incubated under at either normal pressure or 2 ATA for 1 or 2 hours in order to recover the DNA damage. The extent of DNA damage was determined via Comet assay. More recovery from DNA damage was observed at 2 ATA than at normal pressure. The activity of the DNA repair enzymes, DNA polymerase-$\beta$, was also evaluated at both normal pressure and 2 ATA. The activity of DNA polymerase-$\beta$ was observed to have increased significantly at the 2 ATA than at normal pressure. In conclusion, the effects of hyperbaric pressure from 1 ATA to 2 ATA on biochemical systems can be either beneficial or harmful. Long term exposure to hyperbaric pressure clearly inhibited cell proliferation and caused genotoxic effects, but short-term exposure to hyperbaric pressure proved to be beneficial in terms of bolstering the DNA repair system. The results of the present study have clinical therapeutic application, and might prove to be an useful tool in the study of genotoxicity in the future.

• 한국연초학회지
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• 제12권1호
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• pp.19-27
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• 1990

지금까지 연기중의 Nicotine, CO등 몇몇 화합물의 함량 측정과 관능 검사등을 통하여 담배의 품질을 평가해 왔다. 그러나 담배 연기중의 수 많은 화학 성분들을 고려할 때 전연기 성분이 생체에 미치는 영향을 측정함으로써 그 품질을 평가할수 있는 새로운 방범이 요구된다. 담배연기에 의한 생체 손상 쿵 가장 일차적이고 영향이 큰 것으로 알려진 활성 산소종(H2O2, O2-, ·OH)은 그 반응성이 크고 life time이 짧기 때문에 측정이 어렵다. 저자들은 이들을 분해하는 효소를 이용하여 연기중에서 생성되는 이들 산소 자유 라디칼을 측정하였으며 그 결과 담배의 종류에 따라 이들의 생성이 현저한 차이를 보여 일반적으로 고급 담배로 알려진 것들은 낮았고 저급 담배일 수록 높았다. 따라서 이들 산소 자유 라디칼의 측정은 흡연과 건강이라는 측면에서 매우 유용한 담배의 품질 평가 방법으로 이용될수 있을 것으로 생각된다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.772-777
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• 2003

선박이 배출하는 안정수(ballast water)는 외부로부터 유해 생물들이 유입되어 전파해 오는 주요경로로써 해양환경의 매우 중요하고 위험한 일종의 하나이지만, 이에 대한 효과적인 처리방법은 아직까지도 개발되지 못하였다. 그러나 최근 강 전리방전을 이용하여 고 밀집 산소와 물분자를 고농도 수산자유기(OH: hydroxyl radical)로 전리, 활성입자를 발생시켜 신속히 확산시키면 넓은 범위에서 비교적 낮은 농도로 유해성 침입 생물을 잔류물 없이 저렴한 비용으로 살균제나 촉매제의 사용 없이 소멸시켜 처리하는 효과적인 새로운 녹색방법을 제안하였다. 또한, 수산기는 강 산화제로써(산화환원 전위는 2.80 eV), 적조생물을 신속, 효과적으로 사멸시켜 잔유물과 오염물 발생 없이 이상적으로 해양적조현상을 처리할 수 있는 활성물질이다. 고출력 강 전리장치를 활용하면 수산기 활성제의 발생 농도를 Sr104 이상으로 얻을 수 있으므로, 해양적조처리에 요구되는 문턱 값 농도(~l$\times$$10^{-6}$)를 충족시킬 수 있으며, 이 경우 적조생물 소멸처리시간은 불과 10 sec 내외이므로 선박 안정수 처리문제와 함께 적조발생의 난문제를 해양동력학적으로 동시에 해결할 수 있는 효과적인 기술이다. 실험결과로부터 시간당 1 k톤의 활성물질을 발생하는 수산기활성제 제조장치의 경우, 약 4$\times$$10^2$ $\textrm{km}^2$/h의 적조해면을 처리할 수 있으며, 그 비용은 약 US$l,000 정도에 상당하므로, 적조에 따른 경제손실과는 비교될 수 없는 저렴하고 효과적인 방법이다. 활성물질의 생성시간과 가공시간은 불과 수십 $\mu\textrm{s}$ 및 수 sec 에 불과하므로, 1 kton/h 용량의 수산기활성제 제조장치의 환산소비동력은 약 200 kW이고, 장치의 체적은 10~30 ㎥의 공간으로 충분하므로, 소형선박으로 상당면적의 적조피해를 효과적으로 해결할 수 있다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권3호
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• pp.127-132
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• 2010

Reactive oxygen species (ROS), which include hydrogen peroxide ($H_2O_2$), the superoxide anion (${O_2}^-{\cdot}$), and the hydroxyl radical ($OH{\cdot}$), are generated as by-products of oxidative metabolism in cells. The cerebral cortex has been found to be particularly vulnerable to production of ROS associated with conditions such as ischemia-reperfusion, Parkinson's disease, and aging. To investigate the effect of ROS on inhibitory GABAergic synaptic transmission, we examined the electrophysiological mechanisms of the modulatory effect of $H_2O_2$ on GABAergic miniature inhibitory postsynaptic current (mIPSCs) in mechanically isolated rat cerebral cortical neurons retaining intact synaptic boutons. The membrane potential was voltage-clamped at -60 mV and mIPSCs were recorded and analyzed. Superfusion of 1-mM $H_2O_2$ gradually potentiated mIPSCs. This potentiating effect of $H_2O_2$ was blocked by the pretreatment with either 10,000-unit/mL catalase or $300-{\mu}M$ N-acetyl-cysteine. The potentiating effect of $H_2O_2$ was occluded by an adenylate cyclase activator, forskolin, and was blocked by a protein kinase A inhibitor, N -(2-[p-bromocinnamylamino] ethyl)-5-isoquinolinesulfonamide hydrochloride. This study indicates that oxidative stress may potentiate presynaptic GABA release through the mechanism of cAMP-dependent protein kinase A (PKA)-dependent pathways, which may result in the inhibition of the cerebral cortex neuronal activity.

• 한국환경과학회지
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• 제26권8호
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• pp.903-911
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• 2017

The purpose of this study was to measure the bioactivity and antioxidant activity of peel from Gardenia jasminoides fructus Ellis (GJE) in Namhae, Korea, following some established methods. CM (Chloroform:Methanol, 2:1, v/v), 70% ethanol, and n-butanol extracts were collected. Flavonoid content and value as a functional food ingredient of GJE peel was investigated through assessing antioxidant [DPPH (1,1'-diphenyl-2-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid)], and hydroxyl radical scavenging activities; superoxide dismutase like ability; ferrous ion-chelating capacity; and tannin content by solvent extraction. Solvent extract antioxidant activities significantly increased (p<0.05) at increasing concentrations (0.2, 0.4, 0.6 mg/mL). GJE peel extracts were less active than the positive control [ascorbic acid, BHA (butylated hydroxyanisole), and EDTA (ethylenediaminetetraacetic acid disodium salt dihydrate)]. Based on the results of this study, GJE peel could be used as a natural antioxidant source due to its high antioxidant activity and bioactive compound content.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.259.1-259.1
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• 2014

Recently non-thermal plasma has been frequently applied to various research fields. The liquid plasma have received much attention lately because of interests in surgical and nanomaterial synthesis applications. Especially, intensive researches have been carried out for non-thermal plasma in liquid by using various electrode configurations and power supplies. We have developed a bioplasma source which could be used in a liquid, in which outer insulator has been covered onto the outer electrode. Also we have also put an insulator between the inner and outer electrode. Based on the surface discharge mode, the nonthermal bioplasma has been generated inside a liquid by using an alternating current voltage generator with peak voltage of 12 kV under driving frequency of 22 KHz. Here the discharge voltage and current have been measured for electrical characteristics. Especially, We have measured discharge and optical characteristics under various liquids of deionized (DI) water, tap water, and saline by using monochromator. We have also observed nitric oxide (NO), hydrogen peroxide (H2O2), and hydroxyl (OH) radical species by optical emission spectroscopy during the operation of bioplasma discharge inside various kinds of DI water, tap water, and saline. Here the temperature has been kept to be $40^{\circ}C$ or less when discharge in liquid has been operated in this experiment. Also we have measured plasma temperature by high speed camera image and density by using either H-alpha or H-beta Stark broadening method.

• 한국환경과학회지
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• 제22권7호
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• pp.863-871
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• 2013

Dielectric discharges are an emerging technique in environmental pollutant degradation, which that are characterized by the production of hydroxyl radicals as the primary degradation species. For practical application of the plasma reactor, reactor that can handle large amounts of water are needed. Plasma research to date has focused on small-scale water treatment. This study was carried out basic study for scale-up of a single DBD (dielectric barrier discharge) plasma reactor. The degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical) was used as a performance indicator of multi-plasma reactor. The experiments is divided into two parts: design parameters [effect of distance of single plasma module (1~14 cm), arrangement of ground electrode (single and multi), rector number (1~5) and power number (1~5)]; operation parameter [effect of applied voltage (60~220 V), air flow rate (1~5 L/min), electric conductivity of solution ($1.4{\mu}S/cm$, deionized water)~18.8 mS/cm (addition of NaCl 10 g/L) and pH (5~9)]. Considering the electric stability of the plasma reactor, optimum spacing between the single plasma module was 2 cm. Multi discharge electrodes - single ground electrode array was selected. Combination of power 3-plasma module 5 was the optimal combination for maximum RNO degradation. The optimum 1st voltage and air flow rate for RNO degradation were 180 V and 4 L/min, respectively. The pH and conductivity of the solution was not influencing the RNO degradation.

• Environmental Engineering Research
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• 제10권3호
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• pp.138-143
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• 2005

Laboratory batch experiments were conducted to evaluate the Fenton degradation rates of phenanthrene. Fenton reactions for the degradation of phenanthrene were carried out with aqueous and slurry phase, to investigate the effects of sorption of phenanthrene onto solid phase. Various types of surfactants and electrolyte solutions were used to evaluate the effects on the phenanthrene degradation rates by Fenton's reaction. A maximum 90% removal of phenanthrene was achieved in aqueous phase with 0.9% of $H_2O_2$ and 300 mg/L of $Fe^{2+}$ at pH 3. In aqueous phase reaction, inhibitory effects of synthetic surfactants on the removal of phenanthrene were observed, implying that surfactant molecules acted as strong scavenger of hydroxyl radicals. However, use of $carboxymethyl-{\beta}-cyclodextrin$ (CMCD), natural surfactant, showed a slight enhancement in the degradation of phenanthrene. It was considered that reactive radicals formed at ternary complex were located in close proximity to phenanthrene partitioned into CMCD cavities. It was also show that Fenton degradation of phenanthrene were greatly enhanced by addition of NaCl, indicating that potent radical ion ($OCI^-$) played an important role in the phenanthrene degradation, although chloride ion might be acted as scavenger of radicals at low concentrations. Phenanthrene in slurry phase was resistant to Fenton degradation. It might be due to the fact that free radicals were mostly reacting with dissolved species rather than with sorbed phenanthrene. Even though synthetic surfactants were added to increase the phenanthrene concentration in dissolved phase, low degradation efficiency was obtained because of the scavenging of radicals by surfactants molecules. However, use of CMCD in slurry phase, showed a slight enhancement in the phenanthrene degradation. As an alternative, use of Fenton reaction with CMCD could be considered to increase the degradation rates of phenanthrene desorbed from solid phase.

• 한국식품영양과학회지
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• 제40권11호
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• pp.1518-1524
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• 2011

본 연구에서는 생지황과 숙지황 물 추출물을 감압농축 시킨 페이스트를 만들어 이화학적 특성과 항산화능을 분석하였다. 명도는 생지황 농축 페이스트보다 숙지황 농축 페이스트가 낮았다. 적색도는 생지황 농축 페이스트가 1.3으로 숙지황 농축 페이스트보다 높게 측정되었다. 황색도는 생지황 농축 페이스트가 0.68로 숙지황 농축 페이스트보다 높게 측정되었으며, 색도는 각 시료간의 유의적인 차이를 나타내었다(p<0.05). 당도는 숙지황 농축 페이스트가 72.0$^{\circ}Brix$를 나타내어 더 높게 나타났고, 환원당 함량 또한 숙지황 농축 페이스트가 44.9%로 더 높게 나타났다. pH는 숙지황 농축 페이스트의 pH가 4.1을 나타내어 생지황 농축 페이스트의 pH인 5.6보다 낮았다. 일반성분 분석에서 조단백은 숙지황 농축 페이스트에서 3.3%, 생지황 농축 페이스트에서 2.0%로 나타나 숙지황 농축 페이스트에서 더 높게 나타났다. 유효성분 분석에서 catalpol 함량은 생지황 농축 페이스트에서 183.1 mg/mL로 검출되었고 숙지황 농축 페이스트에서는 검출되지 않았으며, 5-HMF는 숙지황 농축 페이스트에서만 검출되었다. 총 phenol 함량 측정 결과 숙지황 농축 페이스트가 12.36 mg/mL로 현저히 높은 함량을 나타내었고 DPPH radical 소거능 측정 결과 $IC_{50}$ 값이 생지황 농축 페이스트, 숙지황 농축 페이스트의 순으로 감소하여 숙지황 농축 페이스트의 항산화능이 더 높게 나타났다. Hydroxyl radical 소거능 측정 결과 $IC_{50}$ 값은 숙지황 농축 페이스트의 값이 1.45 mg/mL로 더 낮게 나타나 숙지황 농축 페이스트의 항산화능이 더 높게 나타났고, FRAP 활성 측정 결과 또한 숙지황 농축 페이스트가 2.02 mg/mL로 더 높아 항산화능이 더 높게 나타났다. 관능검사 결과, 숙지황 농축 페이스트의 선호도가 더 높은 것으로 나타났다. 이러한 결과로 보아 지황의 농축페이스트 중에서 식품소재로 활용될 때 숙지황 농축 페이스트가 더 적당한 것으로 사료된다.