• KSBB Journal
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• 제15권2호
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• pp.156-161
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• 2000

해양에서 분리한 Streptomyces sp. BH-405의 배양액으로부터 정제하여 얻은 항산화 활성이 우수한 획분 band 2 에 대하여 사람 Low Density Lipoprotein(LDL)의 산화 억제 효과에 대하여 실험하였다. Streptomyces sp. BH-405의 배양액으로부터 분리 정제한 획분 band 2는 LDL에 대한 $5\mu\textrm{m}$ $CuSO_4$ 의 유도 산화를 측정한 결과 100 및 200 $\mu\textrm{g}$/mL에서 LDL의 산화억제 효과가 높았다. 그리고, band 2를 이용한 macrophage 및 J774 유도 LDL의 수식에 대한 항상화 효과도 native LDL에 비하여 높았다. 이때 같은 농도의 band 2를 첨가하여 산화 LDL의 전기영동의 이동거리를 측정한 결과 native LDL보다는 약간 높았으나 Oxid LDL의 대조군보다는 이동거리가 낮으며 공액2중결합의 생성억제 효과도 있었다. 사람 LDL의 산화에 대하여 macrophage 및 내피세포를 이용하여 125I-LDL 산화에 대하여 band 2를 각각 100 및 200 $\mu\textrm{g}$/mL씩 첨가하여 실험한 결과 사람 LDL의 분해는 대조구보다 낮았으며 용량 의존형의 결과를 나타내었다.

• 대한화학회지
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• 제57권6호
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• pp.703-711
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• 2013

In the present investigation, kinetic studies of oxidation of formic acid with and without catalyst and promoter in aqueous acid media were studied under the pseudo-first order conditions [formic acid]T ${\gg}[Cr(VI)]_T$ at room temperature. In the 1,10-phenanthroline (phen) promoted path, the cationic Cr(VI) phen complex is the main active oxidant species undergoes a nucleophilic attack by the substrate to form a ternary complex which subsequently experiences a redox decomposition through several steps leading to the products $CO_2$ and $H_2$ along with the Cr(III) phen complex. The anionic surfactant (i.e., sodium dodecyl sulfate, SDS) and neutral surfactant (i.e., Triton X-100, TX-100) act as catalyst and the reaction undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Whereas the cationic surfactant (i.e., N-cetyl pyridinium chloride, CPC) acts as an inhibitor restricts the reaction to aqueous phase. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. The neutral surfactant TX-100 has been observed as the suitable micellar catalyst for the phen promoted chromic acid oxidation of formic acid.

• 한방안이비인후피부과학회지
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• 제20권1호통권32호
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• pp.1-15
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• 2007

Objectives : RVC has long been used for a useful natural agent ameliorating inflammation related symptoms in the folk medicine recipe. This study was performed to investigate effects of RVC on the inflammation and oxidation in RAW 264.7 cells. Methods : The RVC was extracted with 80% ethanol and sequentially partitioned with solvents in order to increase polarity. With the various fractions, we determined the activities on the inflammation and oxidation in RAW 264.7 cells. Results : 1. Among the various solvent extracts of RVC, the butanol fraction showed the most powerful inhibitory ability against nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells without affecting cell viability. 2. Butanol fraction showed a oxidation inhibition effect by decreasing the DPPH and OH radicals. 3. Butanol fraction exhibited the inhibitory avilities against iNOS and COX-2. 4. Reverse transcriptase polymerase chain reaction (RT-PCR) and Westem blotting analysis revealed that the BuOH fraction provided a primary inhibitor of the iNOS protein and mRNA expression in LPS-induced RAW 264.7 cells. Among the up-regulater molecules of iNOS and COX-2, the BuOh fraction of RVC was shown the inhibitory activity of phoshporylation of c-Jun N-terminal kinase (JNK) 1/2 and threonine protein kinase (AKT), the one of the MAPKs pathway. Conclusion : Thus, the present study suggests that the response of a component of the BuOH fraction to NO generation via iNOS expression provide a important clue to elucidate anti-inflammatory and anti-oxidation mechanism of RVC.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.511-517
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• 1992

Ethanol was utilized by mixed rumen microbes, but addition of pentachlorophenol (25 mg/l), a methanogen inhibitor, suppressed the utilization of ethanol. Carbon monoxide (50% of the gas phase), a hydrogenase inhibitor, more strongly suppressed the utilization of ethanol, propanol, and butanol. These results suggest that the major ethanol utilizers are $H_2$ producers. Ethanol utilization was depressed at low pH (below 6.0). Since methanogens were shown to be relatively resistant to low pH, it appears that ethanol utilizers are particularly sensitive to low pH. Ruminococcus albus and R. flavefaciens in mono-culture produced ethanol from carbohydrate (glucose and cellobiose), even when a high level (170 mM) of ethanol was present. Ethanol was not utilized even in the absence of carbohydrate, but the co-culture of these bacteria with methanogens resulted in the utilization of ethanol, i.e., when $H_2$ was rapidly converted to $CH_4$, R. albus and R. flavefaciens utilized ethanol. These results suggest that ethanol is utilized when the electrons liberated by the oxidation of ethanol are rapidly removed, and ready electron disposal in ethanol-utilizing, $H_2$-producing bacteria is accomplished by the interspecies transfer of $H_2$.

• 한국산학기술학회논문지
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• 제11권6호
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• pp.2306-2310
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• 2010

상수도관의 부식은 수돗물이 공급되는 과정에서 관 표면의 금속과 물 사이의 일련의 복잡한 산화/환원 반응이다. 부식으로 인해 발생할 수 있는 1차적인 고려사항은 철, 납, 동과 같은 독성이 있는 중금속이 물속에 존재할 수 있다는 것이며, 이는 상수도관에 악영향을 미치며, 세탁물을 훼손하거나 맛을 낼 수 있는 심미적인 문제도 발생된다. 본 연구에서는 부식억제제가 상수도관의 부식도, 수돗물 중의 철 및 동의 용출 농도에 어떠한 영향을 미치는지에 대해서 평가하였다. 부식저감 효과는 인산염계 부식억제제와 큰 관련성이 있었다. 부식반응은 물과 관의 표면에서 이루어지는 일련의 전기화학적인 반응임을 고려하면 철의 용출농도와 부식도는 양(+)의 상관관계에 있다.

• 대한의생명과학회지
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• 제17권4호
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• pp.283-289
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• 2011

Our previous study demonstrated that the Korean traditional medicine Gyeongshingangjeehwan (GGEx) activates AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) critical for fatty acid oxidation in skeletal muscle and C2C12 skeletal muscle cells. Thus, we examined whether GGEx can reduce lipid accumulation in these cells and tissues. After obese and type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats were treated with GGEx, we studied the effects of GGEx on skeletal muscle lipid accumulation. The effects of GGEx and/or the AMPK inhibitor compound C on lipid accumulation and expression of AMPK and $PPAR{\alpha}$ were measured in C2C12 skeletal muscle cells. Compared with lean Long-Evans Tokushima Otsuka rats, obese OLETF rats had increased triglyceride droplets. However, administration of GGEx to OLETF rats for 8 weeks significantly decreased triglyceride droplets in skeletal muscle. Consistent with the $in$ $vivo$ data, GGEx inhibited lipid accumulation, the degree of which was comparable to Wy14,643, the potent activator of $PPAR{\alpha}$. GGEx also increased skeletal muscle mRNA levels of AMPK${\alpha}1$, AMPK${\alpha}2$, and $PPAR{\alpha}$. However, compound C inhibited these effects in C2C12 cells. These results suggest that GGEx suppresses skeletal muscle lipid accumulation and this process may be mediated by AMPK and $PPAR{\alpha}$ activation.

• 한국세라믹학회지
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• 제34권5호
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• pp.483-490
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• 1997

Al2O3/metal composites were fabricated by oxidation and reaction of molten Al-alloy into two types of commercial Al2O3-SiO2 fibrous insulation board. The growth rate, composition and microstructure of these materials were described. An AlZnMg(7075) alloy was selected as a parent alloy. Mixed polycrystalline fiber and glass phase fiber were used as a filler. The growth surface of an alloy was covered with and without SiO2. SiO2 powder was employed as a surface dopant to aid initial oxidation of Al-alloy. Al-alloy, SiO2, fiber block and growth inhibitor CaSiO3 were packed sequentially in a alumina crucible and oxidized in air at temperature range 90$0^{\circ}C$ to 120$0^{\circ}C$. The growth rate of composite layer was calculated by measuring the mass increasement(g) per unit surface($\textrm{cm}^2$). XRD and optical microscope were used to investigate the composition and phase of composites. The composite grown at 120$0^{\circ}C$ and with SiO2 dopant showed rapid growth rate. The growth behavior differed a little depending on the types of fiber used. The composites consist of $\alpha$-Al2O3, Al, Si and pore. The composite grown at 100$0^{\circ}C$ exhibited better microstructure compared to that grown at 120$0^{\circ}C$.

• 생약학회지
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• 제35권3호통권138호
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• pp.233-238
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• 2004

Lipoprotein-associated phospholipase $A_2\;(Lp-PLA_2)$ is a potential biomarker of coronary heart disease and plays an important proinflammatory role in the progression of atherosclerosis. Also acyl-CoA: cholesterol acyltransferase (ACAT) and oxidized low-density lipoprotein (LDL) playa key role in atherosclerosis, respectively. And so, the inhibitory activities of the methanol extracts of 42 insect resources were examined on $Lp-PLA_2$, ACAT, and LDL oxidation for screening of anti-atherogenic substances. Among them, the methanol extracts of Eurydema rugosa significantly inhibited all of upper three activities. Several kinds of tested insects having high inhibitory effect with the methanol extracts were extracted with n-hexane, ethyl acetate, and acetone, and their inhibitory activities were tested.

• 한국식품영양학회지
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• 제12권3호
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• pp.320-327
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• 1999

The flavonoids are one of the most numberous and widespread groups of natural consituents. The low molecular weight of benzo-${\gamma}$-pyrone derivative are ubiquitous in plants and are vegetables nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds ubiquitous in plants containing a number of phenolic hydroxyl groups attached to ring structures conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vasclar disease indicating that oxidation may be important in the pathogenesis of human athero-sclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. How-ever hydroxylation of the flavone uncleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process the leading cause of death and disability in industrialized societies.

• 한국재료학회지
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• 제34권3호
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• pp.163-169
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• 2024

As the limitations of Moore's Law become evident, there has been growing interest in advanced packaging technologies. Among various 3D packaging techniques, Cu-SiO₂ hybrid bonding has gained attention in heterogeneous devices. However, certain issues, such as its high-temperature processing conditions and copper oxidation, can affect electrical properties and mechanical reliability. Therefore, we studied depositing only a heterometal on top of the Cu in Cu-SiO₂ composite substrates to prevent copper surface oxidation and to lower bonding process temperature. The heterometal needs to be deposited as an ultra-thin layer of less than 10 nm, for copper diffusion. We established the process conditions for depositing a Co film using a Co(EtCp)₂ precursor and utilizing plasma-enhanced atomic layer deposition (PEALD), which allows for precise atomic level thickness control. In addition, we attempted to use a growth inhibitor by growing a self-assembled monolayer (SAM) material, octadecyltrichlorosilane (ODTS), on a SiO₂ substrate to selectively suppress the growth of Co film. We compared the growth behavior of the Co film under various PEALD process conditions and examined their selectivity based on the ODTS growth time.