• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.804-811
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• 2013

The effects and significance of ${\gamma}$-amino butyric acid (GABA) producing bacteria (GPB) on in vitro rumen fermentation and reduction of biogenic amines (histamine, methylamine, ethylamine, and tyramine) using corn meal as a substrate were determined. Ruminal samples collected from ruminally fistulated Holstein cows served as inoculum and corn was used as substrate at 2% dry matter (DM). Different inclusion rates of GPB and GABA were evaluated. After incubation, addition of GPB had no significant effect on in vitro fermentation pH and total gas production, but significantly increased the ammonia nitrogen ($NH_3$-N) concentration and reduced the total biogenic amines production (p<0.05). Furthermore, antioxidation activity was improved as indicated by the significantly higher concentration of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) among treated samples when compared to the control (p<0.05). Additionally, 0.2% GPB was established as the optimum inclusion level. Taken together, these results suggest the potential of utilizing GPB as feed additives to improve growth performance in ruminants by reducing biogenic amines and increasing anti-oxidation.

• Journal of Oral Medicine and Pain
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• v.21 no.2
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• pp.207-224
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• 1996

This study was designed to determine the most effective concentration of fluoride and energy density of laser irradiation for the anticarious effect. For this study surface hardness in enamel was measured before and after irradiation with pulsed Nd;YAG laser and the topical application of fluoride. Of the permanent mandibular anterior hovine teeth, healthy, carious free ones were used. Three hundred specimens were made. Specimens within 25~45 Vickers hardness numbers were assigned to 20 control and experimental stoops ; each containing 15 specimens. After forming artificial carious lesions, 10 J/$\textrm{cm}^2$, 20 J/$\textrm{cm}^2$, and 30 J/$\textrm{cm}^2$ energies were irradiated on the enamel surface of each experimental group. Also NaF, NH4F, Elmex gel(amine fluoride) and APF gel fluoride compounds were applied topically. Next, all the specimens were placed into the pH circulatory procedures for eight days. Vickers hardness numbers were measured using a microhardness tester. Surface changes of the enamel were observed using an scanning electron microscope. The comparative ana1ysis yielded the following results : 1. The reduction of surface hardness of the enamel surface was less in all groups with fluoride application than in the group without fluoride application. 2. The APF gel croup with 10 J/$\textrm{cm}^2$ irradiation showed the lowest reduction of surface hardness. 3. The reduction of surface hardness of the enamel surface in the group of laser irradiation without fluoride application not showed any significant difference according to the energy density of the laser. 4. Under the scanning electron microscope, in enamel irradiated with 10J/$\textrm{cm}^2$ showed appearance similar to acid etching surface. In enamel irradiated with 20 J/$\textrm{cm}^2$, line enamel crack was detected. In enamel irradiated with 30j/$\textrm{cm}^2$, severe enamel crack and fusion of enamel were detected. These results suggest that one could obtain the best anticariogenic effects without damage to teeth in the group of application of APF gel after laser irradiation with 10 J/$\textrm{cm}^2$.

• Membrane Journal
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• v.30 no.5
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• pp.307-318
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• 2020

Conventional perfluorinated sulfonic acid membrane, Nafion is widely used for vanadium redox flow battery (VRFB). It is desired to prevent vanadium ion permeation through a membrane to retain the capacity, and to keep the cell efficiency of a VRFB. Highly proton conductive and chemically stable Nafion membranes, however, suffer from high vanadium permeation, which induce the reduction in charge and discharge capacity by side reactions of vanadium ions. In this study, to resolve the issue, silica nanoparticles, which are functionalized with 3-aminopropyl group (fS) are introduced to enhance the long-term performance of a VRFB by lowering vanadium permeation. It is expected that amine groups on silica nanoparticles are converted to positive ammonium ion, which could deteriorate positively charged vanadium ions' crossover by Gibbs-Donnan effect. There is reduction in proton conductivity may due to acid-base complexation between fS and Nafion side chains, but ion selectivity of proton to vanadium ion is enhanced by introducing fS to Nafion membranes. With the composite membranes of Nafion and fS, VRFBs maintain their discharge capacity up to 80% at a high current density of 150 mA/㎠ during 200 cycles.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.73-83
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• 2014

The objective of the this study was to investigate the binding capacity and removal ability of lactic acid bacterial strains obtained from Korean soybean paste for mutagenic heterocyclic amines (HCAs) formed during cooking of protein-rich food at high temperature. Among 19 strains identified by carbohydrate fermentation and 16S rRNA sequencing, the live cell or cell-free culture supernatant of Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66, and Lactobacillus plantarum D70 inhibited the mutagenesis caused by either 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) in Salmonella typhimurium TA98 and TA100. The bacterial cells of the isolated strains showed greater binding activity than the pure cell wall, exopolysaccharide, and pepetidoglycan. The carbohydrate moieties of the cell wall or protein molecules on the cell surface have a significant role in binding Trp-P-1 and Trp-P-2, since protease, heating, sodium metaperiodate, or acidic pH treatments significantly (P<0.05) reduced the binding efficacy of the tested bacteria. Addition of metal ions or sodium dodecyl sulfate decreased the binding ability of E. faecium D12, L. acidophilus D38, and E. faecalis D66. Therefore, the binding mechanisms of these strains may consist of ion-exchange and hydrophobic bonds. Especially, the high mutagen binding by L. acidophilus D38 and L. plantarum D70 may reduce the accumulation or absorption of Trp-P-1 and Trp-P-2 in the small intestine via increased excretion of a mutagen-bacteria complex.

• KSBB Journal
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• v.19 no.3
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• pp.215-220
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• 2004

A variety of solid bases such as inorganic bases, basic anion exchange resins, and resin-bound bases were tested as a catalyst for racemization of (S)-naproxen 2,2,2-trifluoroethyl thioester in isooctane at 45$^{\circ}C$. Among the various bases, DIAIOM WA30, which is a weakly basic anion exchange resin with a tertiary amine based on a highly porous type styrene-divinylbenzene copolymer, showed the highest catalytic activity. The second-order interconversion constant of DIAION WA30 was 8.6${\times}$10$\^$-4/ mM$\^$-1/h$\^$-1/ and about 3 times higher than that of trioctylamine under the same conditions. The rate of DIAION WA30-catalyzed racemization decreased with increasing an amount of water added to the reaction medium. Lipase-catalyzed kinetic resolution of racemic naproxen 2,2,2-trifluoroethyl thioester was successfully carried out under in situ racemization of substrate with DIAION WA30 in isooctane at 45$^{\circ}C$. More than 60% conversion and 99% enantiomeric excess for the desired (S)-naproxen product were obtained. Furthermore, such a solid base catalyst could be easily separated and reused in contrast to trioctylamine.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.753-758
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• 1997

Dried alaska pollack is one of the representatives among dried marine fish and shellfish products in our country. This study was performed to obtain the basic data about the effect of drying method on the formation of N-nitrosamine and its precursor to ensure the safety of dried alaska pollack. The contents of nitrate and nitrite were detected 1.5 and <1.0 mg/kg in raw samples, and $3.0\~4.2,\;1.4\~2.7mg/kg$ in dried products, respectively. There was no significant change of betaine contents during drying while TMAO decreased, TMA and DMA increased in alaska pollack during d교ing. N-nitrosodimethylamine (NDMA) was only detected in alaska pollack and its dried products, and recovery from above samples spiked with $10{\mu}/kg$ for N-nitrosodipropylamine was $87.2\~107.4\%$. The levels of NDMA were found to be $2.8{\mu}/kg$ on an average in raw samples, but the levels of NDMA increased remarkably during drying of alaska pollack and its content in dried products was $8.7\~51.4{\mu}g/kg$. Regardless of drying methods, NDMA tend to increased in dried products, and its contents were 15.5 times higher in hot-air dried than raw samples, 9.0 times in sun dried and 4.4 times in freeze dried products. less NDMA was produced in the freeze dried products, so it is believed that freeze drying method is effective to decrease the NDMA levels in the dried products of alaska pollack.

• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.31-37
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• 1996

The protective effect of 'ischemic preconditioning (IP)'on ischemia-reperfusion injury of heart has been reported in various animal species, but the mechanism is unclear. In an attempt to elucidate the mechanism of IP, we examined the effects of blockers against adenosine and protein kinase C in preconditioned heart of rat. The hearts perfused with oxygen-saturated Krebs-Henseleit solution by Langendorff method were exposed to 30 min global ischemia followed by 20 min reperfusion. IP was performed with three episodes of 5 min ischcmia and 5 min reperfusion just before ischemia-reperfusion. IP prevented the depression of contractile function and the myocardial contracture in the ischemic-reperfused heart and reduced the release of lactate dehydrogenase during the reperfusion period. Polymyxin B, chelerythrine and colchicine, PKC inhibitors, attenuated almost completely the anti-ischemic effect of IP, while adenosine receptor antagonists did not. These results indicate that PKC may be a crucial intracellular mediator in anti-ischemic action of IP in ischemic-reperfused rat heart, while adenosine may not be involved in the mechanism of IP.

• The Korean Journal of Pharmacology
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• v.2 no.1 s.2
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• pp.21-29
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• 1966

Dichloroisoproterenol(DCI) i; one of the well known ${\beta}$-adrenergic receptor blocking agents. According to Moran and Perkins, DCI has sympathomimetic like action in relatively low concentrations. Fleming and Hawkins confirmed that DCI acts upon the receptors concerned with positive chronotropic and inotropic actions in the heart. Vogins reported that DCI, in concentration of $5{\times}10^{-8}$ to $5{\times}10^{-6}g/ml$, had properties of sympathomimetic amine causing positive inotropic and chronotropic actions in normal rat atria. And James and Nadeau found that DCI had not only adrenergic blocking effect in moderate and higher concentrations, but it also blocked the effect on the sinus node by vagal stimulation and of directly administered acetylcholine in higher concentrations. As stated above by many authors, DCI has complicated actions according to its concentrations. Our aim at the present experiments was to study the effects of DCI to the action of ouabain and acetylcholine upon the excised rabbit atria, as well as to the action of barium chloride and acetylcholine upon the excised rabbit intestine. In addition, Pan ax Ginseng is widely used as tonics in oriental nations, its pharmacological action, however, has not been clearly established. So we atempted to investigate the effects of the water extract of Panax Ginseng to the action of ouabain and DCI upon both atria and intestine. The results obtained were as follows. 1) DCI has a negative inotropic effect on the excised rabbit atria at concentration of $10^{-5}$ and a positive inotropic effect at concentration of $10^{-6}$. 2) DCI (at concentration of $10^{-6}$) potentiates the positive inotropic effect of ouabain upon the excised rabbit atria. 3) DCI antagonizes the action of acetylcholine upon the excised rabbit atria. 4) The water extract of Panax Ginseng, at concentration of $10^{-3}$, decreases the contractile force of rabbit atria, and tends to slightly increase that of rabbit atria at $10^{-4}$. 5) The water extract of Panax Ginseng exhibits a synergistic action with ouabain on the contractile force of rabbit atria. 6) DCI, in concentrations of $10^{-7}{\sim}10^{-6}$, depresses the tone and amplitude of contraction of the excised rabbit intestine. The depression of the intestinal tone markedly appears in pretreatment with reserpine 2mg/kg 24 hours. 7) DCI antagonizes the contractile effect of barium chloride on the excised rabbit atria. 8) DCI has no significant influence on the action of acetylcholine upon the excised rabbit intestine. 9) The series of those evidences indicates that DCI has a sympathomimetic-like action and more over a relaxing action directly on the excised rabbit intestine. 10) The water extract of Panax Ginseng in concentrations of $10^{-4}{\sim}10^{-3}$, has transient depression of the intestinal tone, but later gradually recovers its normal motility: 11) The water extract of Panax Ginseng has a synergistic action with ouabain on the intestinal contractility.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.20-28
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• 1999

Chloronicotinyl derivatives were synthesized by substitution of amino in 3-pyridylmethylamine with phosphite groups and their insecticidal and fungicidal activities were determined. At 500 ppm, compound 4 with methyl and butyl group in phosphonate and compound 5, 6, 7, and 8 with two butyl, 2,2,2-trifluorotehtyl, 2-ethylhexyl, phenyl, respectively, in phosphonate showed 90% insecticidal activities against brown plant-hopper (Nilaparvate lugens). These compounds showed, however, poor insecticidal activities against diamond-back moth (Plutella xylostella) and two-spotted spider mite (Tetranychus urticae) (<65%), suggesting that insecticidal activity of chloronicotinyl derivatives containing phosphorus moieties are species-dependent. Newly synthesized chloronicotinyl derivatives with halogen and/or heterocycle (compound $10{\sim}21$) did not show insecticidal activities. We also determined fungicidal activity of the synthesized chloronicotinyl derivatives against rice sheath blight (Pyricularia grisea), cucumber gray mold (Bortytis cinerea), tomato late blight (Phytophthora infestans), wheat leaf rust (Puccinia recondita), and barley powdery mildew (Erysiphe graminis). Compound 10 with butyl and 4-nitrophenyl in phosphonate at 10 ppm showed 85% fungicidal activity against rice blast, suggesting that chloronicotinyl derivatives containing phosphorus moieties could be developed as a fungicidal agent of a novel chemical structure.

• Journal of Environmental Impact Assessment
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• v.29 no.3
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• pp.198-209
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• 2020

In this study, electrospun nanofibers made of PAN (polyacrylonitrile) were activated through a physical method to obtain an optimized pore structure. In particular, to enhance the surface alkalinity, the activated carbon fibers (ANFs) were impregnated with tetraethylenepentamine (TEPA) with the aid of HNO₃. Then, the low level (3,000 ppm) CO₂ adsorption capacity for each ANF sample was evaluated. The specific surface area of ANFs increased from 308.4 ㎡/g to 839.4 ㎡/g and the total pore volume increased from 7.882 ㎤/g to 27.50 ㎤/g. Although the TEPA impregnation reduced the specific surface area and pore volume of the ANFs due to blocking of micropores, the HNO₃ pre-oxidation enhanced the amino groups tethered, increasing the amine content from 6.42% to 17.19%, and finally, increased the adsorption capacity of CO₂. This study showed that the sample 60-ANF-HNO₃-TEPA, which was activated for 60 minutes and was impregnated with HNO₃ and TEPA, had the best adsorption capacity for low level (0.3%) CO₂ (in a binary mixture with N₂).