• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.263-268
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• 2022

The current study examined the impact of fermented barley sprout extract prepared using lactic acid bacteria (Lactobacillus sp.) in decreasing odor and increasing livestock productivity and measured the difference in the polyphenol and flavonoid contents of the extract after fermentation. Furthermore, the effectiveness of fermented barley sprout extract was evaluated through order level and production index of livestock by supplying it to a broiler house. The results showed that with fermented barley sprout extract, the polyphenol and flavonoid contents were increased significantly by 174% and 562%, respectively. When the extract was applied as an additive to drinking water in the test farm, the productivity improved by about 10%, the mortality rate was reduced by about 66%, and there was a significant decrease in odor by about 80%. Compared with the control group, the production index increased by about 21%, the feed requirement decreased by about 8%, the odor showed a decrease in the NH₃ level, and no other gas was detected. It was observed that lactic acid bacteria settle in the intestine, suppress the proliferation of bacteria that cause diarrhea and enteritis, and help digestion. The lactic acid bacteria effectively remove bad odor gases such as NH₃, Amines, H₂S and CH₄S. Such odor reduction improves productivity. Our findings provide valuable information for quality water supply, production optimization and livestock management.

• Journal of Ginseng Research
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• v.33 no.3
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• pp.183-188
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• 2009

To produce ginsenoside-Rg$_3$ enriched edible yeast, ginseng steaming effluent (GSE) was used for yeast cultivation in this study. Four kinds of edible yeasts were cultured in sterilized GSE (2% w/v, pH 6.5), without any nutrient, for 48 h at 30$^{\circ}C$, and their growth and ginsenoside compositions were determined. Among the yeasts, Saccharomyces cerevisiae showed the highest growth in the GSE medium. 267.1 mg of Saccharomyces cerevisiae biomass was produced from 1 g of GSE solid and ginsenoside-Rg$_3$ contents was determined with 0.033 mg. Saccharomyces cerevisiae also showed the best overall acceptability, with a herbal and fermentative flavor and a slightly bitter taste. From these data, we conclude that Saccharomyces cerevisiae is the excellent strain for production of ginsenoside-Rg$_3$ enriched edible yeast using GSE.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.11-17
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• 2020

Copper has been proved to be the best catalyst for electrochemical CO2 reduction reaction, however, for optimal efficiency and selectivity, its performance requires improvements. Electrochemical CO2 reduction reaction (RR) using CuO nanowire electrode was performed with different concentrations of KHCO3 electrolyte (0.1 M, 0.5 M, and 1 M). Cu(OH)2 was formed on Cu foil, followed by thermal-treatment at 200℃ under the air atmosphere for 2 hrs to transform it to the crystalline phase of CuO. We evaluated the effects of different KHCO3 electrolyte concentrations on electrochemical CO2 reduction reaction (RR) using the CuO nanowire electrode. At a constant current (5mA), low concentrated bicarbonate exhibited a more negative potential -0.77 V vs. Reversible Hydrogen Electrode (RHE) (briefly abbreviated as VRHE), while the negative potential reduced to -0.33 VRHE in the high concentration of bicarbonate solution. Production of H2 and CH4 increased with an increased concentration of electrolyte (KHCO3). CH4 production efficiency was high at low negative potential whereas HCOOH was not influenced by bicarbonate concentration. Our study provides insights into efficient, economically viable, and sustainable methods of mitigating the harmful environmental effects of CO2 emission.

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.522-527
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• 2022

Among efforts to improve techniques for the chemical vapor deposition of large-area and high-quality graphene films on transition metal substrates, being able to reliably transfer these atomistic membranes onto the desired substrate is a critical step for various practical uses, such as graphene-based electronic and photonic devices. However, the most used approach, the wet etching transfer process based on the complete etching of metal substrates, remains a great challenge. This is mainly due to the inevitable damage to the graphene, unintentional contamination of the graphene layer, and increased production cost and time. Here, we report the systematic study of an H₂ bubbling-assisted transfer technique for graphene films grown on Cu foils, which is nondestructive not only to the graphene film but also to the Cu substrate. Also, we demonstrate the origin of the graphene film tearing phenomenon induced by this H₂ bubbling-assisted transfer process. This study reveals that inherent features are produced by rolling Cu foil, which cause a saw-like corrugation in the poly(methyl methacrylate) (PMMA)/graphene stack when it is transferred onto the target substrate after the Cu foil is dissolved. During the PMMA removal stage, the graphene tearing mainly appears at the apexes of the corrugated PMMA/graphene stack, due to weak adhesion to the target substrate. To address this, we have developed a modified heat-press-assisted transfer technique that has much better control of both tearing and the formation of residues in the transferred graphene films.

• Journal of Periodontal and Implant Science
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• v.50 no.5
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• pp.291-302
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• 2020

Purpose: The objective of this study was to investigate whether phelligridin D could reduce glucose-induced oxidative stress, attenuate the resulting inflammatory response, and restore the function of human periodontal ligament cells (HPDLCs). Methods: Primary HPDLCs were isolated from healthy human teeth and cultured. To investigate the effect of phelligridin D on glucose-induced oxidative stress, HPDLCs were treated with phelligridin D, various concentrations of glucose, and glucose oxidase. Glucose-induced oxidative stress, inflammatory molecules, osteoblast differentiation, and mineralization of the HPDLCs were measured by hydrogen peroxide (H₂O₂) generation, cellular viability, alkaline phosphatase (ALP) activity, alizarin red staining, and western blot analyses. Results: Glucose-induced oxidative stress led to increased production of H₂O₂, with negative impacts on cellular viability, ALP activity, and calcium deposition in HPDLCs. Furthermore, HPDLCs under glucose-induced oxidative stress showed induction of inflammatory molecules (intercellular adhesion molecule-1, vascular cell adhesion protein-1, tumor necrosis factor-alpha, interleukin-1-beta) and disturbances of osteogenic differentiation (bone morphogenetic protein-2, and -7, runt-related transcription factor-2), cementogenesis (cementum protein-1), and autophagy-related molecules (autophagy related 5, light chain 3 I/II, beclin-1). Phelligridin D restored all these molecules and maintained the function of HPDLCs even under glucose-induced oxidative stress. Conclusions: This study suggests that phelligridin D reduces the inflammation that results from glucose-induced oxidative stress and restores the function of HPDLCs (e.g., osteoblast differentiation) by upregulating autophagy.

• Resources Recycling
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• v.30 no.5
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• pp.25-31
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• 2021

Smelting reduction of spent lithium-ion batteries results in the production of metallic alloys in which reduced cobalt, nickel and copper coexist. In this study, we investigated the leaching of the metallic alloys containing the above three metals together with iron, manganese, and silicon. The mixture of hydrochloric acid and hydrogen peroxide as an oxidizing agent was employed, and the effect of the concentration thereof, the reaction time and temperature, and pulp density was investigated to accomplish the complete leaching of cobalt, nickel, and copper. The effect of the hydrogen peroxide concentration and pulp density on the leaching was prominent, compared to that of reaction time and temperature, especially in the range of 20 to 80℃. The complete leaching of the metals present in metallic alloys, except silicon, was accomplished using 2 M HCl and 5% H₂O₂ with a pulp density of 30 g/L for 150 min at 60℃.

• Korean Journal of Pharmacognosy
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• v.53 no.4
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• pp.192-201
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• 2022

This study aimed to compare bioactivities of Centella asiatica (CA) cultivated in smart farms and fields. Component analysis, cell viability, anti-inflammatory activity, neuroprotection activity, and antioxidant activity were examined with 70% ethanol extracts of CA cultivated in smart farm (SEE) and field (FEE), respectively. Asiaticoside was analyzed by high performance liquid chromatography (HPLC) and as a result, SEE had more asiaticoside content than FEE. After treatment of RAW 264.7 cells with SEE and FEE, there was no cytotoxicity within the treated concentrations. SEE and FEE showed nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 inhibitory activities in a dose-dependent manner in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Moreover, SEE inhibited more NO, TNF-α, and IL-6 production levels than FEE. SEE and FEE reversed the H₂O₂-induced SH-SY5Y cell death. Especially, SEE was more effective in changing the H₂O₂-induced SH-SY5Y cell death than FEE. The antioxidant activity was confirmed by various methods such as total phenol content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide dismutase (SOD). As a result, SEE showed the most potent antioxidant activities about TPC, DPPH, and SOD methods. This study suggested that SEE has higher bioactivities such as effect of anti-inflammation, neuroprotection, and antioxidation than FEE.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.464-472
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• 2022

An endo-polygalacturonase (endo-PGase) exhibiting excellent performance during acidic fruit juice production would be highly attractive to the fruit juice industry. However, candidate endo-PGases for this purpose have rarely been reported. In this study, we expressed a gene from Penicillium oxalicum in Pichia pastoris. The recombinant enzyme PoxaEnPG28C had an optimal enzyme activity at pH 4.5 and 45℃ and was stable at pH 3.0-6.5 and < 45℃. The enzyme had a specific activity of 4,377.65 ± 55.37 U/mg towards polygalacturonic acid, and the K_m and V_max values of PoxaEnPG28C were calculated as 1.64 g/l and 6127.45 U/mg, respectively. PoxaEnPG28C increased the light transmittance of orange, lemon, strawberry and hawthorn juice by 13.9 ± 0.3%, 29.4 ± 3.8%, 95.7 ± 10.2% and 79.8 ± 1.7%, respectively; it reduced the viscosity of the same juices by 25.7 ± 1.6%, 52.0 ± 4.5%, 48.2 ± 0.7% and 80.5 ± 2.3%, respectively, and it increased the yield of the juices by 24.5 ± 0.7%, 12.7 ± 2.2%, 48.5 ± 4.2% and 104.5 ± 6.4%, respectively. Thus, PoxaEnPG28C could be considered an excellent candidate enzyme for acidic fruit juice production. Remarkably, fruit juice production using hawthorn as an material was reported for the first time.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.127-131
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• 2020

Objective: This study was conducted to determine catalytic properties of wheat phytase with exopolyphosphatase activity toward medium-chain and long-chain inorganic polyphosphate (polyP) substrates for comparative purpose. Methods: Exopolyphosphatase assay of wheat phytase toward polyP75 (medium-chain polyP with average 75 phosphate residues) and polyP1150 (long-chain polyP with average 1150 phosphate residues) was performed at pH 5.2 and pH 7.5. Its activity toward these substrates was investigated in the presence of Mg²⁺, Ni²⁺, Co²⁺, Mn²⁺, or ethylenediaminetetraacetic acid (EDTA). Michaelis constant (K_m) and maximum reaction velocity (V_max) were determined from Lineweaver-Burk plot with polyP75 or polyP1150. Monophosphate esterase activity toward p-nitrophenyl phosphate (pNPP) was assayed in the presence of polyP75 or polyP1150. Results: Wheat phytase dephosphorylated polyP75 and polyP1150 at pH 7.5 more effectively than that at pH 5.2. Its exopolyphosphatase activity toward polyP75 at pH 5.2 was 1.4-fold higher than that toward polyP1150 whereas its activity toward polyP75 at pH 7.5 was 1.4-fold lower than that toward polyP1150. Regarding enzyme kinetics, K_m for polyP75 was 1.4-fold lower than that for polyP1150 while V_max for polyP1150 was 2-fold higher than that for polyP75. The presence of Mg²⁺, Ni²⁺, Co²⁺, Mn²⁺, or EDTA (1 or 5 mM) exhibited no inhibitory effect on its activity toward polyP75. Its activity toward polyP1150 was inhibited by 1 mM of Ni²⁺ or Co²⁺ and 5 mM of Ni²⁺, Co²⁺, or Mg²⁺. Ni²⁺ inhibited its activity toward polyP1150 the most strongly among tested additives. Both polyP75 and polyP1150 inhibited the monophosphate esterase activity of wheat phytase toward pNPP in a dose-dependent manner. Conclusion: Wheat phytase with an unexpected exopolyphosphatase activity has potential as a therapeutic tool and a next-generational feed additive for controlling long-chain polyP-induced inappropriate inflammation from Campylobacter jejuni and Salmonella typhimurium infection in public health and animal husbandry.

• Journal of the Korean Ceramic Society
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• v.52 no.6
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• pp.423-428
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• 2015

The machinability of materials is an important factor in engineering applications. Many ceramic components that have complex shapes require machining, typically using diamond tools, which leads to high production cost. Machinable ceramics containing h-BN have recently been developed, but these materials are very expensive because of high cost of raw materials and machining. Therefore the development of low-cost machinable ceramics is desirable. In this study, mullite-$ZrO_2$ ceramics were prepared additions of $Al_2TiO_5$. $ZrSiO_4$, $Al_2O_3$, and $Al_2TiO_5$ powders mixed at various molar ratios with sintering at 1400, 1500, and $1600^{\circ}C$ for 1 hr. Phase formation and microstructure of the sintered ceramics were observed by XRD and SEM, respectively. The machinability of each specimen was tested using the micro-hole machining method. The machinability results show that the ceramics sintered at temperatures over $1500^{\circ}C$ can be used as good low-cost machinable mullite-$ZrO_2-Al_2TiO_5$ ceramics.