• Journal of Plant Biotechnology
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• v.50
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• pp.215-224
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• 2023

Disinfecting water containing pathogenic microbes is crucial to the food safety of fresh green agricultural products. The UV-activated peracetic acid (UV/PAA) treatment process is an efficient advanced oxidation process (AOP) and a versatile approach to disinfecting waterborne pathogens. However, its effects on plant growth remain largely unknown. This study found that low-dose UV/PAA treatment induced moderate oxidative stress but enhanced the innate immunity of Arabidopsis against Pseudomonas syringae pv. (Pst) DC3000. When applied as water sources, 5- and 10-ppm UV/PAA treatments slightly reduced biomass and root elongation in Arabidopsis seedlings grown under hydroponic conditions. Meanwhile, treatments of the same doses enhanced defense against Pst DC3000 infection in leaves. Accumulation of hydrogen peroxide and callose increased in UV/PAA-treated Arabidopsis samples, and during the post-infection period, UV/PAA-treated seedlings maintained vegetative growth, whereas untreated seedlings showed severe growth retardation. Regarding molecular aspects, priming-related defense marker genes were rapidly and markedly upregulated in UV/PAA-treated Arabidopsis samples. Conclusively, UV/PAA treatment is an efficient AOP for disinfecting water and protecting plants against secondary pathogenic attacks.

• Biomedical Science Letters
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• v.27 no.4
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• pp.264-269
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• 2021

The purpose of this study was to evaluate the disinfecting efficacy of peracetic acid (PAA), sodium hypochlorite (NaOCl) and phenol, which are representative disinfectants in medical environments using four types of multi-drug resistance (MDR) clinical isolates with healthcare-associated infections (HAI). 26 antibiotic susceptibility tests were conducted for the four types of MDR clinical isolates in the same way as for clinical specimens. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the disinfectants were determined by using in vitro liquid medium dilution method and inoculation of the plate medium. Both the MIC and MBC of phenol against MRSA and VRE were 3.1%, while those against KPC and MRPA were 6.2%. The MIC and MBC of peracetic acid (PAA) against MRSA, VRE, KPC, and MRPA were 0.18%. The MIC and MBC of sodium hypochlorite (NaOCl) against MRSA were 0.39% and 0.78%, respectively. Both values of MIC and MBC were 0.78% for VRE. In addition, KPC and MRPA showed 0.39% for MIC and 0.78% for MBC. For all MDR strains used in this study, sodium hypochlorite and peracetic acid showed significant sterilizing efficiency, while no clear correlation was identified between antibiotic resistance clinical isolated and ability of disinfection.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.769-779
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• 2020

This study investigates the selective fractionation of lignin with uniform structures and lower molecular weight. Lignin solubilization was first performed using a solution of acetic acid (AA) and hydrogen peroxide (HP) (4:1, (v/v)) to form peracetic acid (PAA), which is a strong oxidant. After the PAA-induced solubilization that occurred at 80℃, totally soluble lignin was extracted by ethyl acetate (EA) and divided into organic- and water-soluble fractions. The EA fraction was then fractionated by open-column using three solutions (chloroform-ethyl acetate, methanol, and water) sequentially. With an increase in the solvent polarity during the fractionation step, the molecular weight of the lignin-derived compounds in the fraction increased. Remarkably, some lignin fractions did not have aromatic structures. These fractions were identified as carboxylic acid-containing polymers like poly-carboxylates. These results conclude that the selective production of lignin-derived polymers with specific molecular weight and structural characteristics could be possible through open-column fractionation.

• Journal of the Korean Wood Science and Technology
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• v.50 no.4
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• pp.283-298
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• 2022

Wood has always been used for various day-to-day applications such as interior or exterior construction materials, and household products. However, it can undergo photodegradation and discoloration by environmental factors including ultraviolet (UV) light, and thus has shortened its service life. Bleaching or delignification of wood surfaces is a suitable solution to stabilize wood against weathering by UV because these techniques can alter or remove the chromophores in lignin, which is a main factor of wood discoloration. To improve the color stability of wood surface according to the lifespan, surface delignification was conducted using peracetic acid (PAA) and hydrogen peroxide (HP) on the woods of Larix kaempferi and Quercus mongolica. After the PAA treatment, L^* increased considerably from 60-70 to 90-95. Furthermore, wood surface color did not change significantly after UV exposure. The color differences (𝜟E^*) between before and after PPA treatment of wood showed the 4.8-12.2 of L. kaempferi, and 1.7-3.7 of Q. mongolica, respectively. The lignin-related peaks in Fourier transform infrared spectroscopy (FT-IR) spectra disappeared with increased duration of PAA treatment. These results confirmed that the lignin component was partially or completely removed after the PAA treatment; the color differences (𝜟E^*) clearly showed that there was a reduction in redness (a^*) and yellowness (b^*), and an increase in lightness (L^*) owing to the removal of lignin. Based on these results, this study demonstrated that the partial removal of lignin from wood surfaces is a fundamental method for resolving photo-degradation.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.290-295
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• 2016

PURPOSE. The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS. One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS. Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION. The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials.