• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.558-566
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• 2017

In this study, we developed an electron-emission OH radical generator for waste water treatment. The stability of the circuitry was ensured by implementing stable pulse waves with a MOSFET and reducing the momentary current rise. The OH radical generator uses a high-voltage and low-current discharger. The performance of the device was evaluated experimentally, which showed that it is possible to produce a stable and uniform pulse waveform for the drain current of the power MOSFET, which is connected to the input side of an AC multiplying converter through negative feedback circuitry with CR-snubber architecture. It was also possible to reduce the excitation current of the converter and improve the stability of the oscillation circuit. In addition, the generator can generate hydroxyl radicals stably. The bactericidal activities were also evaluated, and the germicidal power for E. coli, S. aureus, and S. flexneriwas improved by 99.9% or more after 60 minutes.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.339-346
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• 2022

This study investigates the antibacterial and antioxidant activities of the ethanol extract of Acer tegmentosum Maxim (EATM) against Staphylococcus aureus. The total polyphenol and flavonoid content, 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging effect, and reducing power of the ferric reducing antioxidant power (FRAP) method were measured to verify the antioxidant activity of the EATM. The antibacterial activity against S. aureus using the EATM was verified by the paper disc method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The total polyphenol and flavonoid contents were 266.66 ㎍ GAE/mg and 6.46 ㎍ QE/mg, respectively. The DPPH and ABTS radical scavenging activity showed a concentration-dependent scavenging activity. The RC₅₀ values of the EATM were 21.49 and 12.81 ㎍/mL, respectively. A FRAP analysis was conducted for evaluating the reducing power of the EATM and an efficacy of 0.73 ± 0.19 mM FeSO₄ E/mg was observed. The antibacterial activity of EATM against S. aureus, determined using the paper disc method, showed an inhibitory ring of 3 mm at 2 mg. The MIC was confirmed at a concentration of ≥ 16 mg/mL, while the MBC was confirmed at 32 mg/mL. As the EATM shows antioxidant and antibacterial activities against S. aureus, it can be used as an effective antidote against atopic dermatitis.