Methionine Supplementation Accelerates Oxidative Stress and Nuclear Factor κB Activation in Livers of C57BL/6 Mice

Chung-Mu Park,Chung-Won Cho,Michael E. Rosenfeld,Young-Sun Song 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.4

The present study was designed to investigate whether hyperhomocysteinemia (HHcy) induced by methionine supplementation promotes oxidative stress and nuclear factor κB (NFκB) activation in livers of C57BL/6 mice when fed a 2% methionine and low folate (1 mg/kg) diet for 12 weeks. Plasma homocysteine concentrations of mice fed methionine were found to be 49 μmol/L by 12 weeks of feeding, which was five times higher than that of controls. HHcy induced by methionine feeding significantly increased oxidative stress, as measured by thiobarbituric acid-reactive substances (P < .05) in livers. This was further confirmed by lower levels of hepatic glutathione (P < .05) and elevated mRNA expressions of hepatic antioxidative enzymes, such as Cu,Zn-superoxide dismutase, catalase, glutathione reductase, and L-gulonolactone oxidase in methionine-fed animals (P < .05). Hepatic function of mice fed methionine seems to be normal, while hepatic triglyceride concentration was lowered by methionine feeding. NFκB nuclear binding activities of livers were higher in the methionine group than in the control group. The above results suggest that HHcy induced by methionine may promote disturbances in lipid peroxidation and antioxidant processes and be a pro-inflammatory mediator in livers of C57BL/6 mice.

Numeral classifiers in Korean -ki nominalizations

Michael Barrie(Michael Barrie ),정희련(Heeryun Chung),안덕호(Duk-Ho An) 경희대학교 언어정보연구소 2022 언어연구 Vol.39 No.3

This paper discusses the structure of numeral classifiers in two types of Korean -ki nominalizations. In the first type (NOM-ki), the object is a full KP, and the properties of numeral classifiers are identical to those of any full KP nominal. In the second type (GEN-ki), the object is a bare nP, and is missing the functional structure necessary for hosting numeral classifiers. As such, the numeral classifier simply adjoins to nP and gives rise to idiosyncratic or culturally relevant readings only. We argue that the Div head is part of the functional spine in Korean. Div is responsible for making the nP countable and able to semantically compose with the numeral classifier. In a full KP object (in NOM-ki), Div is present, and the numeral classifier composes Div+nP, giving rise to standard counting semantics. In a bare nP object (in GEN-ki), Div is absent. The numeral classifier cannot semantically compose with nP. We argue, following Harley (2009), that a non-compositional meaning can arise akin to compounds.

Comparing the liking for Korean style salad dressings and beverages between US and Korean consumers: Effects of sensory and non-sensory factors

Chung, Lana,Chung, Seo-Jin,Kim, Jin-Young,Kim, Kwang-Ok,O’Mahony, Michael,Vickers, Zata,Cha, Sung-Mi,Ishii, Rie,Baures, Katie,Kim, Haeng-Ran Elsevier 2012 Food quality and preference Vol.26 No.1

<P><B>Highlights</B></P><P>► Acceptance of Korean foods among US and Koreans were investigated. ► Stronger cultural differences were observed in the beverage than salad dressing. ► Familiarity and perceived context (traditional vs. ethnic) were both important. ► Labeling effect was relatively small compared to other factors. ► Food/flavor scales may partly predict the acceptance of Korean foods.</P> <P><B>Abstract</B></P><P>The effects of sensory and non-sensory factors on the liking of Korean style salad dressings and beverages among US subjects in two locations (California and Minnesota) and Korean subjects were investigated. Four types of dressing and five types of beverage samples were evaluated. Approximately, half of the subjects evaluated the samples under blind-labeled conditions while the other half evaluated the samples labeled with their corresponding names and flavor descriptions. The liking of each sample was rated and the reasons for liking and disliking each sample were surveyed. Various food attitudes were measured on the food neophobic scale, VARSEEK scale, and flavor attitude scales. Soy sauce & vinegar dressing was the most preferred sample among the US subjects, whereas sesame seed dressing was preferred as much as the soy sauce & vinegar dressing among Koreans. Cinnamon-ginger flavored beverage was preferred the most among the US subjects, whereas rice punch was preferred the most among Koreans. Sample labeling effect was relatively small compared to other factors. VARSEEK and food neophobia scale showed stronger effect on beverage than salad dressing. Preference attitudes for hot & spicy and roasted carbohydrate flavors affected the acceptance of salad dressing among consumers in California whereas preference attitude for garlic flavor affected the acceptance of dressing among consumers in Minnesota.</P>

Degradation of organic compounds in wastewater matrix by electrochemically generated reactive chlorine species: Kinetics and selectivity

Chung, Chong Min,Hong, Seok Won,Cho, Kangwoo,Hoffmann, Michael R. Elsevier 2018 CATALYSIS TODAY - Vol.313 No.-

<P><B>Abstract</B></P> <P>In this study, we examined the kinetics and selectivity of chemical oxygen demand (COD) degradation by electrochemically generated reactive oxygen species (RCS) in variable wastewater matrix. According to measurements on reactive oxidants and linear sweep voltammetry, oxidation of organics either via reactive oxygen species or direct electron transfer played a minor role for the active IrO<SUB>2</SUB> anode. The RCS (mostly free chlorine in bulk solution) exclusively mediated an indirect oxidation with mean current efficiency from 25 to 40%. In batch galvanostatic experiments for single polymeric compounds, the rate of COD reduction showed marginal variations in spite of the large difference in reactivity with the RCS. Eight different wastewater samples were prepared from greywater and urine for potentiostatic experiments. The kinetics of COD degradation in municipal wastewater was observed to more sluggish than in the urinary samples with initial elevations in [COD]. Fractionation of COD into proteins, carbohydrates, and carboxylates could explain the shift in kinetics, in terms of the reactivity with RCS and the ratio of COD to theoretical oxygen demand (ThOD) for each components. The anaerobic biodegradation of the organic matrix greatly improved the subsequent reactivity with RCS, which rationalizes a combination of electrochemical processes with biological pretreatment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Homogeneous oxidation by RCS mediation is exclusive pathway for IrO<SUB>2</SUB> anodes. </LI> <LI> Organic array in greywater shows slower reaction with RCS than that in blackwater. </LI> <LI> Protein species is important components for the kinetics of COD degradation. </LI> <LI> Anaerobic biodegradation enhances apparent COD removal by electrolytic RCS. </LI> <LI> The kinetics of COD decay should consider the reactivity with RCS and COD/ThOD. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

ON A MEASURE ZERO STABILITY PROBLEM OF A CYCLIC EQUATION

CHUNG, JAEYOUNG,RASSIAS, JOHN MICHAEL Cambridge University Press 2016 Bulletin of the Australian Mathematical Society Vol.93 No.2

<P>Let $G$ be a commutative group, $Y$ a real Banach space and $f:G\rightarrow Y$. We prove the Ulam-Hyers stability theorem for the cyclic functional equation $$\begin{eqnarray}\displaystyle \frac{1}{|H|}\mathop{\sum }_{h\in H}f(x+h\cdot y)=f(x)+f(y) & & \displaystyle \nonumber\end{eqnarray}$$ for all $x,y\in {\rm\Omega}$, where $H$ is a finite cyclic subgroup of $\text{Aut}(G)$ and ${\rm\Omega}\subset G\times G$ satisfies a certain condition. As a consequence, we consider a measure zero stability problem of the functional equation $$\begin{eqnarray}\displaystyle \frac{1}{N}\mathop{\sum }_{k=1}^{N}f(z+{\it\omega}^{k}{\it\zeta})=f(z)+f({\it\zeta}) & & \displaystyle \nonumber\end{eqnarray}$$ for all $(z,{\it\zeta})\in {\rm\Omega}$, where $f:\mathbb{C}\rightarrow Y,\,{\it\omega}=e^{2{\it\pi}i/N}$ and ${\rm\Omega}\subset \mathbb{C}^{2}$ has four-dimensional Lebesgue measure $0$.</P>

Thermochemical degradation of cotton fabric under mild conditions

Michael Cuiffo,정혜정,Asta Skocir,Theanne Schiros,Emily Evans,Elizabeth Orlando,Yu-Chung Lin,Yiwei Fang,Miriam Rafailovich,Taejin Kim,Gary Halada 한국의류학회 2021 Fashion and Textiles Vol.8 No.1

Textile waste presents a major burden on the environment, contributing to climate change and chemical pollution as toxic dyes and finishing chemicals enter the environment through landfill leachate. Moreover, the majority of textile waste reaching landfills is discarded clothing, which could be reused or recycled. Here we investigate environmentally benign morphology changing of cotton textiles as a precursor for reintegration into a circular materials economy. At 50 °C using low concentrations of acids and bases, the interfiber structures of woven cotton were successfully degraded when treated with the following sequence of chemical treatment: citric acid, urea, sodium hydroxide, ammonium hydroxide, and sodium nitrate. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) reveal separation of the constituent fibers without depolymerization of the cellulose structure, and streaming potential measurements indicate that surface charge effects play a key role in facilitating degradation. The proposed reaction procedures show feasibility of effective waste-fabric recycling processes without chemically intensive processes, in which staple fibers are recovered and can be re-spun into new textiles.

Genotoxicity Assessment of Erythritol by Using Short-term Assay

Chung, Young-Shin,Lee, Michael Korean Society of ToxicologyKorea Environmental Mu 2013 Toxicological Research Vol.29 No.4

Erythritol is a sugar alcohol that is widely used as a natural sugar substitute. Thus, the safety of its usage is very important. In the present study, short-term genotoxicity assays were conducted to evaluate the potential genotoxic effects of erythritol. According to the OECD test guidelines, the maximum test dose was 5,000 ${\mu}g$/plate in bacterial reverse mutation tests, 5,000 ${\mu}g/ml$ in cell-based assays, and 5,000 mg/kg for in vivo testing. An Ames test did not reveal any positive results. No clastogenicity was observed in a chromosomal aberration test with CHL cells or an in vitro micronucleus test with L5178Y $tk^{+/-}$ cells. Erythritol induced a marginal increase of DNA damage at two high doses by 24 hr of exposure in a comet assay using L5178Y $tk^{+/-}$ cells. Additionally, in vivo micronucleus tests clearly demonstrated that oral administration of erythritol did not induce micronuclei formation of the bone marrow cells of male ICR mice. Taken together, our results indicate that erythritol is not mutagenic to bacterial cells and does not cause chromosomal damage in mammalian cells either in vitro or in vivo.

Study for Offshore Jacket Structure Monitoring and International Standardization of Off-Shore Structure

Michael M. S. Lee,Chul Chung 대한토목학회 2016 대한토목학회 학술대회 Vol.2016 No.10

Genotoxicity Assessment of Gardenia Yellow using Short-term Assays

Chung, Young-Shin,Eum, Ki-Hwan,Ahn, Jun-Ho,Choi, Seon-A,Noh, Hong-June,Seo, Young-R.,Oh, Se-Wook,Lee, Michael The Korean Society of Toxicogenomics and Toxicopro 2009 Molecular & cellular toxicology Vol.5 No.3

Gardenia yellow, extracted from gardenia fruit, has been widely used as a coloring agent for foods, and thus, safety of its usage is of prime importance. In the current study, short-term genotoxicity assays were conducted to evaluate the potential genotoxic effects of gardenia yellow. The gardenia yellow used was found to contain 0.057 mg/g of genipin, a known biologically active compound of the gardenia fruit extract. Ames test did not reveal any positive results. No clastogenicity was detected by a chromosomal aberration test, even on evaluation at the highest feasible concentration of gardenia yellow. Gardenia yellow was also shown to be non-genotoxic using an in vitro comet assay and a micronucleus test with L5178Y cells, although a marginal increase in DNA damage and micronuclei frequency was reported in the respective assays. Additionally, in vivo micronucleus test results clearly demonstrated that oral administration of gardenia yellow did not induce micronuclei formation in the bone marrow cells of male ICR mice. Taken together, our results indicate that gardenia yellow is not mutagenic to bacterial cells, and that it does not cause chromosomal damage in mammalian cells, either in vitro or in vivo.

Motional Stark effect diagnostics for KSTAR

Chung, J.,Ko, J.,Howard, J.,Michael, C.,von Nessi, G.,Thorman, A.,De Bock, M. F. M. 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.