• 생약학회지
• /
• 제47권2호
• /
• pp.150-157
• /
• 2016

Earth worm (Eisenia andrei) and clam worm (Perinereis linea) have been used as anti-bacterial and anti-inflammatory agent. However, it is unclear how they exerted their physiological effects in macrophages. In this experiment, the anti-inflammatory and antioxidant effects of clam worm extract (CWE) and earth worm extract (EWE) in RAW264.7 cells were examined by measuring MDA, catalase, SOD, GSH-Px and inflammatory cytokines (nitric oxide, iNOS, interleukin-$1{\beta}$ and tumor necrosis factor-${\alpha}$). Treatment with CWE significantly increased the activities of catalase, SOD and GSH-Px in RAW264.7 cells and decreased the level of MDA. Interestingly, treatment with CWE induced more activities of SOD than EWE. In addition, CWE decreased NO production, iNOS, COX-2, TNF-${\alpha}$ and IL-$1{\beta}$ in RAW264.7. The EWE also decreased NO production and iNOS, but increased COX-2 and IL-$1{\beta}$ suggesting that CWE could be better resources for anti-inflammatory and antioxidant agent than EWE. Taken together, these results indicate that CWE has the potential as a natural antioxidant and a therapeutic for inflammation-related diseases.

• 생약학회지
• /
• 제45권2호
• /
• pp.147-153
• /
• 2014

This study was focused on the evaluation of radical scavenging effect and the protective activity against oxidative stress of the extract and fractions from Petasites japonicus. P. japonicus was extracted with methanol and then fractionated into 4 fractions [n-butanol, ethyl acetate (EtOAc), methylene chloride, and n-hexane]. The extract and fractions showed strong 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Among all the fractions, particularly, the EtOAc fraction showed the strongest effect with the $IC_{50}$ value of $0.02{\mu}g/ml$. In addition, the fractions also showed strong hydroxyl radical scavenging activity and nitric oxide scavenging activity as well. Furthermore, cell viability generated by the P. japonicus extract and 4 fractions were examined under C6 glial cellular model. The C6 glial cells showed high generation of reactive oxygen species (ROS) and decrease in cell viability by the treatment generator of hydrogen peroxide. However, the production of ROS formation was decreased by the treatment of the fractions of P. japonicus and also founded that the EtOAc fraction led to significant increase in the cell viability at concentration $100{\mu}g/ml$. Results from this work indicated that P. japonicus showed protective effects against oxidative stress and its EtOAc fraction may be served as a useful natural antioxidant.

• 한국물환경학회지
• /
• 제22권6호
• /
• pp.991-995
• /
• 2006

The layered double hydroxide with the insertion of chloride ions (LDH-Cl), which was synthesized by the co-precipitation method, was applied to investigate the fundamental aspects of the absorptive agent for phosphate removal from wastewater. The adsorption capacity was best described by the Langmuir-FreundIich isotherm, and the estimated isotherm parameters indicate that the LDH-CI capacity for the phosphate removal is much higher than that observed using a natural adsorbent material such iron oxide tailing. The kinetic experiment also showed that the LDH-Cl adsorption reaction rapidly at the adsorptive rate of 0.55 mg-P/g-LDH/min, implying that this adsorbent can be of use in the full-scale applications. The pH had a minimal effect on the LDH adsorption capacity in the range of 5 to 11, although the capacity dropped at the low pHs because of the change in LDH surface properties. Furthermore, other anions such as $Cl^-$ and $NO_3{^-}$ commonly found in the wastewater streams insignificantly affected the phosphate removal efficiencies, while $HCO_3{^-}$ ions had a negative effect on the LDH adsorption capacity due to its high selectivity. The phosphate removal experiment using the actual secondary effluent from a wastewater treatment plant showed the similar decrease in adsorption capacity, indicating that the bicarbonate ions in the wastewater were competing with phosphate for the adsorptive site in the surface of the LDH-Cl. Overall, the synthetic adsorbent material, LDH-Cl, can be a feasible alternative over other conventional chemical agents, since the LDH-Cl exhibits the high phosphate removal capacity with the low sensitivity to other environmental conditions.

• 환경위생공학
• /
• 제21권3호
• /
• pp.15-26
• /
• 2006

As traffic in city-centre around the world continues to increase, so levels of atmospheric pollutants continue to rise. High concentrations of NOx can have negative effects on human health, and we must find new ways to reduce their levels in the air we breathe. Nitrogen oxide gas (NOx), consisting of nitrogen monoxide (NO) and nitrogen dioxide $(NO_2)$ produced using $O_3$ oxidation, at a low concentration corresponding to that on roads as a result of exhaust from automobiles, was carried out to evaluate the removal characteristics of NOx through a laboratory-scale biofilter packed with soil as a packing material. A mixture media (yellow soil (30%): soil (40%): compost (10%): a used briquet (20%)) was applied. After about 1day of operation, the removal efficiency for $NO_2$ in all experiments with a constant condition ($25^{\circ}C$ and water humidity (60%)) was over 98%. The retention times of the section between phase I and phase II for formation and reduction of $NO_3$ NO and $NO_2$ on the initial $NO_3$ concentration was 50min $(O_3:195\;ppb),\;55min\;(O_3:925\;ppb),\;65min\;(O_3:1743\;ppb),\;70min\;(O_3:2616\;ppb),\;75min\;(O_3:3500\;ppb)$, respectively The soil biofilter system is a unique technology that purifies urban air by utilizing the natural processes that take place in the soil. Although some of the processes are quite complex, they can broadly be summarized as adsorption onto soil particles, dissolution into soil pore water, and biochemical.

• 한국결정성장학회지
• /
• 제1권2호
• /
• pp.23-33
• /
• 1991

Mn-Zn Ferrite는 단결정을 성장하기 위하여 용융하는 동안 불균질 용융과 ZnO휘발의 고유특성을 갖는 재료이다. 그 결과로, 결정성장축을 따라 양이온의 분포가 불균일 하게 된고 또한 기존의 Bridgman법에서는 도가니내에서 용융대가 장시간 유지됨으로써 백금입자가 결정안으로 침입하게된다. 이들은 훼라이트의 자기적 성질을 저하시키는 성질을 갖고 있다. 그러나 새로운 성장법에서는 이러한 단점들을 극복하고 양질의 단결정을 얻기 위하여 결정성장 인자들의 관계를 고찰하였으며 그 인자들은 다음과 같다 : 도가니내의 melt 높이, melt의 표면장력과 밀도, 계면에서의 melt거동, 도가니와 고액계면의 형상, 원료공급속도, 결정성장속도. 아울러, 성장된 결정의 조성을 분석하였을 때 초기조성과 비교하여 $\textrm{Fe}_2\textrm{O}_3$ 1.5 mol%, MnO, Zn 2.0 mol% 이내로 조성 변동은 각각 억제되었고 성장결정면 (110)에서 화확적인 etching 법을 이용하여 광학현미경을 통해 결정내부등을 관찰하였으며, 자기적 특성등을 측정하였다.

• 한국수소및신에너지학회논문집
• /
• 제22권4호
• /
• pp.443-450
• /
• 2011

The three-reactor chemical-looping process (TRCL) for the production of hydrogen from natural gas is attractive for both $CO_2$ capture and hydrogen production. In this study, redox property of $Fe_2O_3$ and $WO_3$ supported with $ZrO_2$ and $MgAl_2O_4$ were studied with temperature programmed oxidation/reduction (TPO/R) experiment. All metal oxides were prepared by ball mill method. Metal oxides supported with $ZrO_2$ showed the good redox property in TPO and TPR tests. Reduction behavior was matched well the theoretical reduction mechanism. Metal oxides supported with $MgAl_2O_4$ formed a solid solution ($MgFe_{0.6}Al_{1.4}O_4$, $MgWO_4$). $Fe_2O_3$ showed more narrow reaction range and lower reaction temperature than $WO_3$.

• KSBB Journal
• /
• 제17권2호
• /
• pp.176-181
• /
• 2002

Astaxanthin (3,3＇-dihydroxy-${\beta}$, ${\beta}$-carotene-4-4＇-dione), a natural pigment of pink to red color, is widely distributed in nature particularly in the skin layer of salmonoids and the crust of shrimp, lobster, etc. Recently, it was produced from the yeast culture of Phaffia rhodozyma. Because of its high thermal stability and antioxidant functionality, its applications can be extended into food, cosmetics, and pharmaceutical ingredient beyond the traditional feed additive. Because of its very high lipophilicity, astaxanthin has been extracted traditionally by strong organic solvents such as chloroform, petroleum ether, acetone, etc. In this study, we developed a surfactant-based solubillization system for astaxanthin, and used it to extract astaxanthin from disrupted yeast cells. Among Tween 20, Triton X-100 and SDS, Tween 20 was identified as the most suitable surfactant in terms of extraction capacity and safety. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effects of micelle formation condition, such as the molar ratio of astaxanthin and Tween 20, pH, and ionic strength were also investigated. pH and ionic strength showed no significant effects. The optimal molar ratio between astaxanthin and Tween 20 was 1 : 12. Antioxidant activity of astaxanthin was higher than ${\beta}$-carotene and ${\alpha}$-tocopherol. Astaxanthin in the crude extract from the yeast cell was more resistant to air and/or light degradation than pure astaxanthin, probably because of the presence of other carotenoids and lipids.

• KSBB Journal
• /
• 제19권1호
• /
• pp.57-61
• /
• 2004

본 연구에서는 항산화 활성을 갖는 유용한 선도 물질을 찾기 위한 일환으로 20종의 염생식물의 추출물에 대해 peroxynitrite와 DPPH 라디칼 소거 활성을 측정하였다. 그 결과 해당화 (Rosa rugosa), 개망초 (Erigeron annus), 냇씀바귀(Ixeris tamagawaensis), 띠 (Imperata cylindrica), 범행초(Tetragonia tetragonoides), 사철쑥 (Artemisia capillaris)의 MeOH 추출물에서 우수한 DPPH 라디칼 소거 효과가 확인되었다. 또한, 해당화(Rosa rugosa), 개망초 (Erigeron annus), 칠면초 (Suaeda japonica), 냇씀바귀 (Ixeris tamagawaensis), 띠 (Imperata cylindrica), 갯방풍 (Glehnia littoralis), 함초(Salicornia herbacea), 해국 (Aster spathulifolius), 범행초 (Tetragonia tetragonoides)의 MeOH 추출물과 CH$_2$Cl$_2$ 추출물에서 각각 peroxynitrite의 소거효과가 관찰되었다. 그 중에서도 해당화 MeOH 추출물의 DPPH 래디칼 소거효과는 100 $\mu\textrm{g}$/$m\ell$ (f.c.) 농도에서 87.51%로 나타났고, peroxynitrite 소거효과는 5 $\mu\textrm{g}$/$m\ell$ 농도에서 표품의 ONOO를 첨가했을 때 97.03%와 SIN-1을 첨가했을 때 98.48%로서 가장 강력한 항산화활성을 가지는 것으로 나타났다. 해당화의 peroxynitrite의 효과는 대조군으로 사용된 penicillamine보다도 우수하며, L-ascorbic acid와 비슷한 효과였다.

• 무역상무연구
• /
• 제12권
• /
• pp.587-613
• /
• 1999

Environmental problems such as global climate change, depletion, ocean and air pollution, and resource degradation-compounded by an expanding world population-respect no border and threaten the health, prosperity and jobs of all mankind. Our efforts to promote democracy, free trade, and stability in the world will fall short unless people have a livable environment. We have an enormous stake in the management of the world's resources. By increasing demand for timber, natural gas, coal and consumer's goods have destroyed the grounds for living. Greenhouse gas emissions anywhere in the world have threatened coastal communities, and then changed the Earth's climate system. The burning of coal, oil, and other fossil fuels is increasing substantially the concentration of heat-trapping gasses such as carbon dioxide, methane, and nitrous oxide in our air. The earth's temperature and sea levels are rising as a result. Since 1972 there has been a marked growth in the number and scope of environmental treaties. In particular, after the 1992 Rio Conference, international legal instruments became more concentrated on addressing environment within the context of sustainable development and incorporated a number of new concepts and innovative approaches. A preliminary analysis of recent conventions and in particular those associated with the Rio Conference indicates various ideas, concepts and principles which have come to the fore including sustainable development, equity, common concern of humankind, common but differentiated responsibilities and global partnership. However, international trade also has an environmental impact which must be minimized or countered. Positive measures are to be preferred to achieve environmental goals, but where trade provisions are necessary, they should be appropriately used within environmental conventions to facilitate the reduction and limitation of the negative impacts of trade and to enhance the complementarity of the multilateral trade regime with the imperatives of environmental protection, in the interests of environmental protection and sustainable development generally. The international community has to recognize and endorse this need to achieve complementarity between trade and environment issues.

• 한국표면공학회지
• /
• 제51권2호
• /
• pp.87-94
• /
• 2018

Various sealing techniques were applied to the anodized 5083 aluminum alloy for marine environment to reduce corrosion and cavitation erosion damage. Electrochemical experiments and cavitation erosion tests were conducted to evaluate the corrosion resistance and cavitation resistance of the anodic oxide film treated with sealing in natural seawater solution. Then, damaged surface morphology was analyzed by scanning electron microscope(SEM) and 3D microscope. As the results of the electrochemical experiments, it was observed that the surface damage of all the experimental conditions in the anodic polarization experiment was locally grown by the combination of crack and corrosion damage. In the Tafel analysis, the corrosion resistance of all sealing treatment conditions was improved compared to the anodizing. On the other hand, cavitation erosion tests showed that the anodizing and all the sealing treatment conditions generated local pit damage by cavitation erosion attack and grew to crater damage in the observation of damaged surface by SEM. Also, the weight loss and the surface damage depth measured with the experiment time presented that most of the sealing treatment conditions showed better cavitation erosion resistance than the anodizing, and they had an incubation period at the beginning of the experiment.