• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.577-584
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• 2016

The objectives of this study were I) to compare the acid resistance (AR) of seven non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups, including O26, O45, O103, O111, O121, O145, and O157:H7 STEC isolated from various sources, in 400 mM acetic acid solution (AAS) at pH 3.2 and $30^{\circ}C$ for 25 min with or without glutamic acid and II) to determine strain survival upon exposure to simulated gastric fluid (SGF, pH 1.5) at $37^{\circ}C$ for 2 h after acid adaptation in apple, pineapple, orange, and strawberry juices at pH 3.8, $4^{\circ}C$ and $20^{\circ}C$. Results show that the O111 serogroup strains had the strongest AR (0.12 log reduction CFU/mL) which was very similar to that of O157:H7 STEC (P>0.05), compared to other serogroups in AAS without glutamic acid, whereas O26 serogroup strains showed the most sensitive AR. However, there was no significant (P>0.05) difference of AR among seven serogroups in AAS with glutamic acid. In the SGF study, 05-6545 (O45:H2), 08023 (O121:H19), and 03-4669 (O145:NM) strains adapted in fruit juices at $4^{\circ}C$ and $20^{\circ}C$ displayed enhanced survival with exposure to SGF for 60 min compared to 06E0218 (O157:H7) strains (P<0.05). In addition, 4 STEC strains adapted in pineapple juice at $4^{\circ}C$ showed enhanced survival with exposure to SGF for 60 min compared to those strains acid-adapted in the other fruit juices. Generally, adaptation at $4^{\circ}C$ in fruit juices resulted in significantly enhanced survival levels compared to acid-adapted at $20^{\circ}C$ and non-adapted conditions. The AR caused by adaptation in fruit juices at low temperature may thus increase survival of non-O157 STEC strain in acidic environments such as the gastrointestinal tract. These results suggest that more careful strategies should be provided to protect against risk of foodborne illness by non-O157 STEC.

• Journal of Life Science
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• v.26 no.11
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• pp.1282-1288
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• 2016

Artemisia, a plant widely used as traditional herbal medicine in many countries, has drawn attention of the researchers. And its extracts or compounds are known to have an efficacy of antioxidant, anti-diabete, anti-cancer, anti-inflammation and neuroprotection. Sumaeyaksuk is a variant of the Artemisia argyi and major constituents are eupatilin and jaceosidin. This study was performed to investigate the effects of the sumaeyaksuk aqueous extract on inflammatory response induced by lipopolysaccharide (LPS) in human hepatoma HepG2 cells. To examine the potential hepatoprotective properties of sumaeyaksuk extract, cell viability, as well as nitric oxide (NO), reactive oxygen species (ROS), macrophage colony-stimulating factor (M-CSF), interleukin-8 (IL-8) levels, alanine transaminase (ALT), and aspartate transaminase (AST) activities, were measured. Cytotoxic activity of extracts on HepG2 cells was measured by MTT assay. Sumaeyaksuk extract did not induce cytotoxicity at concentrations of $0{\sim}400{\mu}g/mL$. NO and ROS levels significantly decreased with increasing concentration of the extract. The secretion levels of M-CSF and IL-8 were suppressed by sumaeyaksuk extract in a dose-dependent manner. Moreover, ALT (75.4%) and AST (61.6%) levels significantly decreased in sumaeyaksuk extract-treated cells at $400{\mu}g/mL$. These results suggested that the sumaeyaksuk extract attenuates the LPS-induced hepatotoxicity resulting from regulation of inflammatory factors and could potentially be used as a hepatitis therapeutic agent.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.701-703
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• 1996

The influence of phenylalanine (Phe) in the medium on protein synthesis of chicken embryo fibroblasts (CEF) was examined. CEF was derived from 9-d-old embryos by trypsin-EDTA digestion. To examine the deficiency of Phe in the medium, CEF was cultured in Dulbecco's modified Eagle's medium (DMEM) with or without Phe. CEF was also cultured in Dulbecco's phosphate buffered saline (PBS ($Ca^{2+}$, $Mg^{2+}$)) with or without $400{\mu}m$ Phe in order to examine the effect of Phe supplementation. All media were supplemented with 10% (v/v) fetal calf serum. After incubation for 6, 30 and 54 h, protein synthesis was measured by the incorporation of L-[2, $6-^{3}H$] Phe into CEF for further 18 h. Protein synthesis of CEF cultured in DMEM was higher than that in PBS ($Ca^{2+}$, $Mg^{2+}$). High specific radioactivity of Phe due to the low concentration of Phe in the medium resulted in the apparent increase in protein synthesis of CEF. Protein synthesis cultured in PBS ($Ca^{2+}$, $Mg^{2+}$) with Phe did not increase during 72 h of cell culture.

• Carbon letters
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• v.8 no.2
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• pp.95-100
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• 2007

A series of activated carbons (ACs) were derived from sugarcane bagasse under two activation schemes: steam-pyrolysis at $600-800^{\circ}C$ and chemical activation with $H_3PO_4$ at $500^{\circ}C$. Some carbons were treated at 400, $600^{\circ}C$, or for 1-3 h, and/or in flowing air during pyrolysis of acid-impregnated mass. XRD profiles displayed two broad diffuse bands centered around $2{\theta}=23$ and $43^{\circ}$, currently associated with diffraction from the 002 and 100/101 set of planes in graphite, respectively. These correspond to the interlayer spacing, Lc, and microcrystallite lateral dimensions, La, of the turbostratic (fully disordered) graphene layers. Steam pyrolysis-activated carbons exhibit only the two mentioned broad bands with enhancement in number of layers, with temperature, and small decrease in microcrystallite diameter, La. XRD patterns of $H_3PO_4$-ACs display more developed and separated peaks in the early region with maxima at $2{\theta}=23$, 26 and $29^{\circ}$, possibly ascribed to fragmented microcrystallites (or partially organized structures). Diffraction within the $2{\theta}=43^{\circ}$ is still broad although depressed and diffuse, suggesting that the intragraphitic layers are less developed. Varying the conditions of chemical activation inflicts insignificant structural alterations. Circulating air during pyrolysis leads to enhancement of the basic graphitic structure with destruction and degradation in the lateral dimensions.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1785-1790
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• 2006

A novel kinetic method for determination of $HO_2{^{\cdot}}/O_2{^{{\cdot}-}}$ in ozone decomposition in water is described. In this study, potential interferences of $O_3$ and the hydroxyl radicals, $^{\cdot}OH_{(O3)}$, are suppressed by $HSO_3{^-}/SO_3{^{2-}}$. $HO_2{^{\cdot}}/O_2{^{{\cdot}-}}$ formed in ozone decomposition reduces $Fe^{3+}$-EDTA into $Fe^{2+}$-EDTA and subsequently the well-known Fenton-like (FL) reaction of $H_2O_2$ and $Fe^{2+}$-EDTA produces the hydroxyl radicals, $^{\cdot}OH_{(FL)}$. Benzoic acid (BA) scavenges $^{\cdot}OH_{(FL)}$ to produce OHBA, which are analyzed by fluorescence detection (${\lambda}_{ex}=320nm$ and ${\lambda}_{ex}=400nm$). The concentration of $HO_2{^{\cdot}}/O_2{^{{\cdot}-}}$ in ozone decomposition has been determined by the novel kinetic method using the experimentally determined half-life ($t_{1/2}$). The steady-state concentration of $HO_2{^{\cdot}}/O_2{^{{\cdot}-}}$ is proportional to the $O_3$ concentration at a given pH. However, the steady-state concentration of $HO_2{^{\cdot}}/O_2{^{{\cdot}-}}$ in ozone decomposition is inversely proportional to pH values. This pH dependence is due to significant loss of $O_2{^{{\cdot}-}}$ by $O_3$ at higher pH conditions. The steady-state concentrations of $HO_2{^{\cdot}}/O_2{^{{\cdot}-}}$ are in the range of $2.49({\pm}0.10){\times}10^{-9}M(pH=4.17){\sim}3.01({\pm}0.07){\times}10^{-10}M(pH=7.59)$ at $[O_3]_o=60{\mu}M$.

• Resources Recycling
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• v.12 no.6
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• pp.13-18
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• 2003

The initial NiCuZn synthetic ferrite were acquired from thermally decomposing the metal nitrates Fe($NO_3$)$_3$ㆍ$9H_2$O, Zn($NO_3$)$_2$ㆍ$6H_2$O, Ni($NO_3$3)$_2$ㆍ $6H_2$O and Cu(NO$_3$)$_2$ㆍ $3H_2$O at 1$50^{\circ}C$ for 24 hours and was calcined at $500^{\circ}C$. Each of those was pulverized for 3 and 9 hours in a steel ball mill and was sintered between $700^{\circ}C$ and $1,000^{\circ}C$ for 1 hour, and then their microstructures and magnetic properties were examined. We could make the initial specimens chemically bonded in liquid at the temperature as low as $150 ^{\circ}C$, by using the melting points less than $ 200^{\circ}C$ of the metal nitrates instead of the mechanical ball milling, then narrowed a distance between the particles into a molecular level, and thus lowed sintering temperature by at least $200 ^{\circ}C$ to $300^{\circ}C$ Their initial permeability was 50 to 490 and their saturation magnetic induction density and coercive force 2,400G and 0.3 Oe to 1.2 Oe each, which were similar to those of NiCuZn ferrite synthesized in the conventional process.

• Journal of the Korean Chemical Society
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• v.28 no.1
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• pp.62-69
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• 1984

The reaction of toluene with ethanol was studied over various cation-exchanged pentasil zeolite catalysts. The toluene disproportionation reaction to produce xylenes increased with increasing reaction temperature and the activity of alkylation of toluene with ethanol showed maximum at around $400^{\circ}C$. Only Cs-ZSM-5 catalyst showed pronounced p-ethyltoluene selectivity increasing to 96% with increasing degree of Cs-exchange. The sorption rate of m-xylene was lower for Cs-exchanged ZSM-5 than H-ZSM-5 catalyst. These phenomena were interpreted in terms of shape selectivity arising from the partial blocking of channel intersections by large cesium ions.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.629-636
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• 2019

Objective: The study was designed to determine the cytotoxic effect of gallic acid (GA), obtained by the hydrolysis of tannins, on mice TM4 Sertoli cells apoptosis. Methods: In the present study, non-tumorigenic mice TM4 Sertoli cells were treated with different concentrations of GA for 24 h. After treatment, cell viability was evaluated using WST-1, mitochondrial dysfunction, cells apoptosis and necrosis was detected using JC-1, Hoechst 33342 and propidium iodide staining. The expression levels of Cyclin B1, proliferating cell nuclear antigen (PCNA), Bcl-2-associated X protein (BAX), and Caspase-3 were also detected by quantitative real-time polymerase chain reaction and Western-blotting. Results: The results showed that 20 to $400{\mu}M$ GA inhibited viability of TM4 Sertoli cells in a dose-dependent manner. Treatment with $400{\mu}M$ GA significantly inhibited PCNA and Cyclin B1 expression, however up-regulated BAX and Caspase-3 expression, caused mitochondrial membrane depolarization, activated Caspase-3, and induced DNA damage, thus, markedly increased the numbers of dead cells. Conclusion: Our findings showed that GA could disrupt mitochondrial function and caused TM4 cells to undergo apoptosis and necrosis.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.849-860
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• 1996

Natural zeolites which were known to occur in sedimentary clinoptilolite, were treated by thermal and chemical methods, and their adsorption characteristics of Cu(II) were studied. Analyses by FT-IR, S. E. M, TGA/DSC, and XRD showed that the adsorption capacity of Cu(II) on the zeolite decreased gradually at the temperatures of above $400^{\circ}C$. The zeolites, which treated with NaOH and NaCl, show higher absorbility in acid solution. The adsorption rate of Cu(II) in the presence of surfactants(LAS, POE AE) on the thermally or chemically treated zeolites varied depending on pH, anion or nonion surfactants.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.69-74
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• 2012

This study investigated the TNT decomposition by the treatment of alkaline hydrolysis. To obtain this objecitive, spectrum shift characteristics, pH effect, kinetics, and product analysis were examined during the alkaline hydrolysis by means of hydroxide ions. At pH = 12, an aqueous solution of TNT was changed into yellow-brown coloring, in which its absorbances were newly increased in a range of wavelength 400-600 nm. From the kinetic data, pseudo-first-order rate constant in a excess of hydroxide ion, in contrast to TNT concentration, was $0.0022min^{-1}$, which means that the reaction rate between TNT and hydroxide ion can be very slow, and that 1,047 min is necessary to achieve a 90% reduction of the initial TNT. In products analyses, nitrite ions and formic acid were mainly produced by the alkaline hydrolysis, nitrate ions and oxalic acid as minor products were generated.