직경 10 μm 미만의 대기 미립자 물질(particulate matter, PM10)은 다양한 신체기관에서 산화 스트레 스와 염증반응을 유발한다. 본 연구의 목적은 인간 표피 각질형성세포(HEK)에서 PM10에 의해 유도되는 반응 성 산소종(ROS) 생성의 메커니즘을 알아보는 것이다. 배양된 HEK를 PM10에 노출시켰을 때 ROS가 증가하였으며, 이는 항산화제 apocynin에 의해 저해되었다. PM10에 의해 유도되는 ROS 생성에서 NADPH oxidase (NOX) family의 역할을 규명하기 위하여 이들의 mRNA 발현을 분석하였다. PM10은 NOX1, NOX2, dual oxidase (DUOX)1 및 DUOX2의 mRNA 발현을 증가시켰다. 다른 NOX들에 비교하여 DUOX1 및 DUOX2의 발현 수준이 높았으며, 이들 효소의 maturation factors, 즉 DUOXA1와 DUOXA2의 mRNA 발현도 PM10에 의하여 증가하였다. 칼슘 의존성 효소인 DUOX1과 DUOX2가 PM10에 의해 유도되는 ROS의 생성을 매개하는 지 조사하였다. 선택적인 세포내 칼슘 킬레이터인 BAPTA-AM은 PM10 및 칼슘 ionophore A23187에 유도된 ROS 생성을 감소시켰다. 작은 간섭 RNA (siRNA)에 의한 DUOX2의 하향 조절은 PM10에 의해 유도된 ROS의 생성을 감소시켰고 DUOX1 siRNA는 영향이 없었다. PM10은 interleukin (IL)-1β, IL-6, IL-8 및 interferon (IFN)-γ 등 사이토카인의 발현을 증가시켰다. siRNA에 의한 DUOX2의 하향 조절은 IFN-γ의 발현을 저해하였지만 다른 사이토카인의 발현은 저해하지 않았다. 본 연구는 PM10에 노출된 HEK의 ROS 생성 및 염증 반응에서 DUOX2가 중요한 역할을 함을 시사한다.

고농도의 산소를 흡입하는 경우에 자기공명영상의 FLAIR(fluid attenuated inversion-recovery, FLAIR) 영상 에서 뇌척수액에서 신호가 억제되지 않고 고신호로 나타나는 경우가 있다는 보고가 있었다. 본 연구는 아가 젤로 고정한 팬텀을 제작하여 산소를 주입한 생리식염수와 조영제를 희석한 생리식염수의 신호를 FLAIR 기법의 반전시간(TI : inversion time)을 변화하여 영상을 획득하고, 분석하여 기초자료를 마련 하고자 하였다. 부산 P병원의 Philips Achieva MR 3.0T를 이용한 결과에서 자기공명영상의 FLAIR 기법에서 산소가 주입된 생리식염수의 신호 대 잡음비(signal to noise ratio)는 산소가 주입되지 않은 생리식염수 보다 증가되었다. 하지만 희석된 조영제보다는 높지 않았다. 반전시간 1,800ms에서는 산소에 의한 신호 증강이 없는 영상을 획득할 수 있었다. 산소가 주입된 생리식염수와 조영제의 대조도 대 잡음비(contrast to noise ratio)에서도 임상에서 주로 사용하는 반전시간 2,800ms보다 1,800ms에서 높게 증가되었다. 본 실험의 결과가 자기공명영상의 FLAIR 기법에서 산소 주입에 따른 뇌척수액의 신호 변화 연구에 기초자료가 될 수 있을 것으로 사료된다.

Water and oxygen are two of the most essential molecules for many species on earth. Their unique properties have been studied in many areas of science. In this study, the interaction of water and oxygen molecules was observed at the nano-scale. Using molecular dynamics, a water droplet with 30,968 water molecules was simulated. Then, 501 oxygen molecules were introduced into the domain. A few oxygen molecules were attracted to the surface of the water droplet due to van der Waals forces, and some oxygen molecules actually entered the water droplet. These interactions were visualized and quantified at four temperatures ranging from 280 to 370 K. It was found that at high temperatures, there was a higher possibility of the oxygen molecules penetrating the water droplet than that at lower temperatures. However, at lower temperatures, oxygen molecules were more likely to be found interacting at the surface of the water droplet than at high temperatures.

Bioremediation in situ is heavily dependent on the oxygenic environment which would privide the dwelling microorganism with sufficient oxygen. The situation could be easily resolved with supply of an Oxygen Releasing Compound (ORC). In this paper we prepared that sort of material out of oyster shell powder (mostly calcium carbonate) that prevails every shore areas of the country. We used two different oxidizing methods in the first step of the whole manufacturing process–conventional heating in a furnace and an ultrasound generator to obtain calcium oxide. Then that calcium oxide was further oxidized into calcium peroxide which may release oxygen under a moisturized condition. The oxygen releasing experiments were run to test the performance of our products, and to determine the gas kinetics during the experiments. Interestingly, calcium peroxide derived from ultrasound treatment was much more energy-effective as ORC than that from furnace heating although the heat derived process was better than that of ultrasound in terms of oxygen content and its releasing rate. We also found that most of the data collected from the gas releasing experiments fairly supported an ordinary 1st order kinetics to oxygen concentration, which shaped a sharp discharge of oxygen at the very early moment of each test.

In this study, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/graphene oxide (GO) nanocomposite films containing various content of GO were prepared using solution casting method. The effect of GO content on Young’s modulus and dispersion of GO in PHBV matrix was investigated. Also, the thermomechanical properties, oxygen transmission rates and hydrolytic degradation of PHBV/GO nanocomposite films were studied. The addition of GO into PHBV improves the Young’s modulus and decreases thermal expansion coefficient. The improvement can be mainly attributed to good dispersion of GO and interfacial interactions between PHBV and GO. Furthermore, PHBV/GO nanocomposite films show good oxygen barrier properties. PHBV/GO nanocomposites show lower hydrolytic degradation rates with increasing content of GO.

Background : Reactive oxygen species (ROS), whether produced endogenously as a consequence of normal cell functions or derived from external sources, pose a constant threat to cells living in an aerobic environment as they can result in severe damage to DNA, protein, and lipids. The effects of Valeriana fauriei extract and fractions on hydrogen peroxide-induced neuronal cell damage are studied. Methods and Results : Oxidative stress plays an important role in the pathological process of neurodegenerative diseases. Valeriana fauriei extract (VFE) and EA fractions (VFEA) was investigated total phenolic contents using method. VFE of total phenolic contents had 2.54 ± 0.01 mg/g, also, VFEA had a 18.78 ± 0.03 mg/g. High phenolic content of the VFEA is expected to better the inhibition of oxidative stress. VFE and VFEA were experimented to inhibit ROS induced 200 μM 3-morpholinosydnonimine (SIN-1). VFE of inhibit SIN-1 induced-ROS dose dependently and signficantly. In addition, VFEA inhibition was also dose dependant and significant. Moreover, Treatment of SH-SY5Y and SK-N-SH cells with VFEA significantly reduced hydrogen peroxide-induced generation of intercellular ROS. Conclusion : From the above results, we may suggest that VFEA might have useful as a material for functional food and pharmaceutics for the pathological process of neurodegenerative diseases.

Dissolved oxygen is necessary for many biological processes as well as many industrial practices. Dissolved oxygen released from water in dissolved air flotation (DAF) systems can be have many different applications. However, DAF systems are very costly to operate. To develop more efficient DAF systems, a deeper understanding of the process of oxygen being released from water is required. In this study, molecular dynamics (MD) simulations were used to simulate 100 oxygen molecules surrounded by 31002 water molecules at temperatures ranging from 0℃ to 100℃. Simulations were carried out for 10 ns, during which, in most cases, all the oxygen molecules were released from the water droplet. With MD simulations, visualization of the molecules escaping the water droplet was possible, which aided the understanding of the interactions between molecules at the nano-scale. The results showed that as the oxygen molecules moved near the edge of the water droplet that the oxygen molecules hesitated before escaping the water droplet or returned to the interior of the water droplet. This was because of the attractive forces between the water and oxygen molecules. Moreover, after most of the oxygen molecules were released from the droplet, some were found to return to the droplet's edge or even the interior of the droplet. It was also confirmed that oxygen molecules were released at a faster rate at higher temperatures.

Background : Osteoclasts as multinucleated cells originate from hematopoietic monocyte/ macrophage precursor cell, shows the bone absorption through the commitment, differentiation, fusion, and bone resorption stages by regulation of M-CSF and RANKL. It has been reported a significant negative correlation between the increase of oxidative stress and the bone density, and when RANKL reaction to the osteoclasts precursor cells is mainly generated ROS is due to increased activity of NADPH oxidase1 (NOX1), and these ROS act as a factor which promotes osteoclasts differentiation. Thus, RANKL signaling process is important that excessive osteoclast formation and differentiation inhibited through the regulation of each step. Methods and Results : F3570 ethanol extract showed relatively high activity at in-vitro antioxidant activity. F3570 water extract inhibited ROS generation in RAW 264.7 cells stimulated with H2O2 and RANKL, even at low concentrations. The inhibitory effect of osteoclast differentiation on F3570 water extract was confirmed that shown through NF-κB pathway, MAPK pathway including ERK and JNK. F3570 ethanol extract is considered to be regulated by the p38 MAPK and the other signaling pathway. Also, F3570 both water and ethanol extract were significantly reduced gene expression such as TRAP, calcitonin receptors and integrin β3 of RANKL-induced mature osteoclast in the bone resorption stage. Conclusion : Through this study, F3570 extract revealed an outstanding inhibitory effect and signaling mechanisms in osteoclast differentiation induced by RANKL. These results suggest that F3570 is bone diseases associated with aging or osteoporosis caused by menopause in an aging society is expected to be a superior candidate for the treatment or the prevention

본 연구는 4종의 별의별간(SS) 음료의 간보호 소재로서 의 이용 가능성을 조사하고자 항산화능 평가, t-BHP 와 CCl4로 산화적 손상 및 급성 간독성 유도한in vitro, in vivo 모델을 활용하여 간보호능을 평가하였다. 실험결과, 별의별간 01~04는 50 μM vitamin C 와 유사한 항산화 효과를 나타내었다. HepG2 세포에 t-BHP로 산화 스트레스를 유도한 뒤 나타나는 세포독성에 대해 별의별간 01 및 04에서 농도 의존적인 세포 보호효과를 보였으며, ROS 생성 억제에서 별의별간 01, 03, 04에서 농도의존적인 억제를 나타내었다. 미나리가 혼합된 별의별간 04에 대한 급성 간손상in vivo 모델을 활용하여 간보호능 검증 결과, 별의별간 04는 CCl4로 증가된 혈중 ALT, AST의 유의적 감소, 간 조직중 증가된 MDA 함량 감소 및 감소된 GSH의 유의적 증가를 나타내었다. 또한, 혈청 및 간 조직에서 증가 된 중성지방과 콜레스테롤을 유의적으로 감소시켰다. 이러 한 결과를 종합하며, 별의별간 04는in vitro 및in vivo 모델 에서 산화적 손상에 대해 간보호 효과를 나타내었다

These days, the development of various pre- and post-combustion techniques has been pursued in order to reduce the emission of CO2 in the fleet of coal-fired power plants, since it is of great importance to each country’s energy production while also being the single largest emitter of CO2. As part of this kind of research efforts, in this study, a novel burning method is tried by the co-burning of the pulverized coal with the stoichiometric mixture of the hydrogen and oxygen (H2+1/2O2) called as HHO. For the investigation of this idea, the commercial computational code (STAR-CCM+) was used to perform a series of calculation for the IFRF (International Flame Research Foundation) coal-fired boiler (Michel and Payne, 1980). In order to verify the code performance, first of all, the experimental data of IFRF has been successfully compared with the calculation data. Further, the calculated data employed with pure coal are compared with the co-burning case for the evaluation of the substituted HHO performance. The reduced amount of coal feeding was fixed to be 30% and the added amount of HHO to produce a similar flame temperature with pure coal combustion was considered as 100% case of HHO addition. This value varies from 100 to 90, 80, 60, 50, 0% in order to see the effect of HHO amount on the performance of pulverized coal-fired combustion with the 30% reduced coal feeding. One of the most important thing found in this study is that the 100% addition of HHO amount shows approximately the same flame shape and temperature with the case of 100% coal combustion, even if the magnitude of the flow velocity differs significantly due to the reduced amount of air oxidizer. This suggests the high possibility of the replacement of the coal fuel with HHO in order to reduce the CO2 emission in pulverized coal-fired power plant. However, an extensive parametric study will be needed in near future, in terms of the reduction amount of coal and HHO addition in order to evaluate the possibility of the HHO replacement for coal in pulverized coal-fired combustion.

본 연구에서는 연화 열수 및 에탄올 추출물의 3T3-L1 지방세포 분화 및 ROS생성 저감효과를 구명하기 위하여 3T3-L1 전지방세포 분화과정 중 연화 열수 및 에탄올 추출 물에 의한 지방축적과 ROS 생성을 관찰하였다. 연화 열수 및 에탄올 추출물은 XTT assay에서 100, 200 및 400 μg/mL 농도에서 세포 독성을 보이지 않았다. 지방세포 분화 중 세포 내 지방축적 및 ROS 생성량을 비교한 결과, 연화 열수 및 에탄올 추출물을 처리한 지방세포의 경우 지방축적량과 ROS 생성량 모두 유의적으로 억제되는 것으로 나타났다. 특히 연화 열수 및 에탄올 추출물을 처리함으로써 지방세포 분화와 관련된 전사인자인 PPARγ, C/EBPα 및 aP mRNA의 발현을 유의적으로 감소시켰으며, ROS의 생성과 관련이 있는 주요 유전자인 NOX4 및 catalase의 유전자발현 또한 유의적으로 감소하였다. 이 결과를 통해 연화 열수 및 에탄 올 추출물이 3T3-L1 지방세포 내 중성지방의 축적 억제 효과와 더불어 ROS 생성 억제에 효과적으로 작용함을 확인 하였다. 따라서 연화 열수 및 에탄올 추출물은 비만과 같은 대사증후군 관련 질환의 개선을 위한 천연물 기능성 소재로 의 활용이 기대된다.

Many researchers have defined critical chloride content as a specific value. The studies reporting critical threshold chloride content have involved the experimental measurement of the average amount of the total chloride content. The studies have tried to define the critical chloride content within the scope of their experimental concrete mix proportion at arbitrary time. However, there is no agreement on its value. The purpose of this study is to explore the combined effect of oxygen and chloride on reinforcement corrosion. In the experimental recipe, water soluble oxygen is taken into account to define the critical chloride content. Corrosion current density of reinforcement was measured by linear polarization resistance method.

Dielectric barrier discharge plasma is a new technique in water pollutant degradation, which that is characterized by the production of chemically active species such as hydroxyl radicals, ozone, hydrogen peroxide, etc. If dissolving of plasma gas generated in the plasma reaction has increased, it is possible to increase the contaminant removal capacity. In this study, the improvement on the dissolving performance of plasma gas was evaluated by the indirect method measuring the overall oxygen transfer coefficient. Experiments were conducted to examine the effects of nozzle type, distance from water surface, air supply rate and liquid circulation rate. The experimental results showed that the KLa value of the 3-prong nozzle is 2.67 times higher than the diffuser. The order of KLa value with nozzle type ranked in the following order: 3-prong nozzle (inner diameter, less 1 mm) > circular nozzle (inner diameter, 1.5 mm) > ellipse nozzle (short diameter 1 mm, long diameter 2.5 mm) > circular nozzle (inner diameter, 3 mm). Optimal liquid circulation rate was appeared to be 1.7 L/min, the value of KLa was 0.510 1/min. The value of KLa with increasing air supply rate was revealed in the form of an exponential such as KLa=0.3581e0.2919＊air flow rate

The Youngsan Lake was constructed to supply agricultural water to the extensive rice fields in the basin of the lake in 1981. Hypoxia has often developed in the bottom water of the lake during the warm season although the water depth is relatively shallow (< 16 m). We investigated the spatial and temporal variations of dissolved oxygen (DO) and physical properties such as water temperature, salinity and turbidity to elucidate the effects of change in physical properties on DO dynamics in the lake. Vertical profiles of DO, temperature, salinity, and water density were also explored to verify the development of stratification in relation to DO variation in the water column. Hypoxia (DO < 2 mg L-1) was not observed in the upper regions whereas hypoxia was detected in the lower regions during the warm season. Thermocline generally developed in the lower regions during the warm season unlike the previous studies in which no thermocline was observed. However, water column was well mixed when freshwater water was discharged from the reservoir through the sluice gate of the dike. DO concentrations also decreased when halocline or pycnocline developed during the dry season suggesting that the vertical stratification of water column affects DO dynamics although the water depth is shallow in the Youngsan lake.

In this study, one of the measures for the promotion of the growth of trees planted in poor drainage areas, which functionality pipe supplying oxygen in the soil, and promotes drainage, barren soil and poor drainage areas in planting design was to provide the basic data to compare the impact on the application of functionality pipe. The Zelkova serrata testing materials were selected, planted a total of 12 by three to four individual experiments were conducted. Growth measurements of the items Plot A > Plot C > Plot D > Plot B were excellent in the order of height, number of leaves, leaf width, and chlorophyll content, Plot A > Plot C > Plot D > Plot B was in good order of the growth of the length of the root-collar diameter, Plot C > Plot A > Plot B > Plot D in order rate of variation was good. This has adverse effects on plant growth, poor drainage planting base represents, promote drainage and oxygen supply technique can be applied good to the planting from Zelkova serrata growth based drainage is poor and barren presented as part of research to be done in the future include a means for promoting the growth of plants in soil, the planting design.

This study carried out a laboratory scale plasma reactor about the characteristics of chemically oxidative species (․OH, H2O2 and O3) produced in dielectric barrier discharge plasma. It was studied the influence of various parameters such as gas type, 1st voltage, oxygen flow rate, electric conductivity and pH of solution for the generation of the oxidant. H2O2 and O3.) H2O2 and O3 was measured by direct assay using absorption spectrophotometry. OH radical was measured indirectly by measuring the degradation of the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical). The experimental results showed that the effect of influent gases on RNO degradation was ranked in the following order: oxygen > air >> argon. The optimum 1st voltage for RNO degradation were 90 V. As the increased of 1st voltage, generated H2O2 and O3 concentration were increased. The intensity of the UV light emitted from oxygen-plasma discharge was lower than that of the sun light. The generated hydrogen peroxide concentration and ozone concentration was not high. Therefore it is suggested that the main mechanism of oxidation of the oxygen-plasma process is OH radical. The conductivity of the solution did not affected the generation of oxidative species. The higher pH, the lower H2O2 and O3 generation were observed. However, RNO degradation was not varied with the change of the solution pH.

Sulfur hexafluoride has an extremely high global warming potential (GWP) because of strong absorption of infraredradiation and long atmospheric lifetime which cause the global warming effect. This study is to identify the effects ofdestruction and removal efficiency of SF6 by the addition of conditioning agent (oxygen, water vapor and hydrogen) whenusing the high ionization energy. The irradiation intensity of ionization energy was 2mA, 5mA, 10mA and 15mA. TheSF6 was completely removed with H2O and H2 gas injection at 2mA. Main by-products were HF and F2 gases. HF andF2 gas formation was increased with irradiation intensity increasing. Most of the by-products of particle were sulfur andmetal sulfate.

Decomposition of non-biodegradable contaminants such as phenol contained in water was investigated using a dielectric barrier discharge (DBD) plasma reactor in the aqueous solutions with continuous oxygen bubbling. Effects of various parameters on the removal of phenol in aqueous solution with high-voltage streamer discharge plasma are studied. In order to choose plasma gas, gas of three types (argon, air, oxygen) were investigated. After the selection of gas, effects of 1st voltage (80 ～220 V), oxygen flow rate (2 ～7 L/min), pH (3 ～11), and initial phenol concentration (12.5 ～100.0 mg/L) on phenol degradation and change of UV254 absorbance were investigated. Absorbance of UV254 can be used as an indirect indicator of phenol degradation and the generation and disappearance of the non-biodegradable organic compounds. Removal of phenol and COD were found to follow pseudo first-order kinetics. The removal rate constants for phenol and COD of phenol were 5.204 × 10-1 min-1 and 3.26 × 10-2 min-1, respectively.