• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.229-235
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• 2019

A floating photovoltaic generation system is a new concept that combines existing photovoltaic generation technology with floating technology. This is installed in the water not on conventional land and a building. The system is designed as a unit module type that can be connected to other modules according to the power generation capacity, thereby forming a large-scale power generation facility. As a renewable energy source, it is composed of a floating structure, mooring device, photovoltaic power generation facility, and underwater cable. Because this system is installed outdoors, the effect of the wind load on the structure is very large. In this study, the wind loads most affected on the floating photovoltaic generation structure were obtained by computational fluid dynamic analysis. The flow characteristics and wind loads were analyzed for a range of wind orientations and angles of inclination. The analysis showed the position and magnitude of the maximum wind load to the wind direction and the flow characteristics around the solar panel and floating system. The wind load increased with increasing angle of inclination of the panel to the ground.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1776-1788
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• 2019

Objective: The demands for measures to improve disease resistance and productivity of livestock are increasing, as most countries prohibit the addition of antibiotics to feed. This study therefore aimed to uncover functional feed additives to help enhance livestock immunity and disease resistance, using Acanthopanax sessiliflorus fruit extract (ASF). Methods: ASF was extracted with 70% EtOH, and total polyphenolic and catechin contents were measured by the Folin-Ciocalteu and vanillin assay, respectively. The 3D4/31 porcine macrophage cells ($M{\Phi}$) were activated by phorbol 12-myristate 13-acetate (PMA), and cell survival and growth rate were measured with or without ASF treatment. Flow-cytometric analysis determined the lysosomal activity, reactive oxygen species levels (ROS), and cell cycle distribution. Nuclear factor kappa B ($NF-{\kappa}B$) and superoxide dismutase (SOD) protein expression levels were quantified by western blotting and densitometry analysis. Quantitative polymerase chain reaction was applied to measure the lipid metabolism-related genes expression level. Lastly, the antibacterial activity of 3D4/31 $M{\Phi}$ cells was evaluated by the colony forming unit assay. Results: ASF upregulated the cell viability and growth rate of 3D4/31 $M{\Phi}$, with or without PMA activation. Moreover, lysosomal activity and intracellular ROS levels were increased after ASF exposure. In addition, the antioxidant enzyme SOD2 expression levels were proportionately increased with ROS levels. Both ASF and PMA treatment resulted in upregulation of $NF-{\kappa}B$ protein, tumor necrosis factor $(TNF){\alpha}$ mRNA expression levels, lipid synthesis, and fatty acid oxidation metabolism. Interestingly, co-treatment of ASF with PMA resulted in recovery of $NF-{\kappa}B$, $TNF{\alpha}$, and lipid metabolism levels. Finally, ASF pretreatment enhanced the in vitro bactericidal activity of 3D4/31 $M{\Phi}$ against Escherichia coli. Conclusion: This study provides a novel insight into the regulation of $NF-{\kappa}B$ activity and lipid metabolism in $M{\Phi}$, and we anticipate that ASF has the potential to be effective as a feed additive to enhance livestock immunity.

• YAKHAK HOEJI
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• v.58 no.5
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• pp.307-313
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• 2014

Rumex crispus (curled dock), which is a perennial wild plant, has long been used as a laxative, astringent, and medicine to treat blood and skin diseases. We recently reported that the roots of R. crispus are an effective nutraceutical for bone. This study prepared ethanol extracts of the leaves and roots of R. crispus, and analyzed the major constituents using liquid chromatography and mass spectrometry. In addition, their effects on the proliferation and differentiation of human osteoblast-like MG-63 cells, such as cell viability, alkaline phosphatase (ALP) activity, collagen content, and mineralization, were compared. The chromatograms of the chemical constituents of the two extracts exhibited quite different profiles: quercetin and quercitrin were identified as major peaks in the leaf extract, whereas cinnamtannin B1 and procyanidin isomers were the major peaks for the root extract. Neither extract was cytotoxic at concentrations of < $25{\mu}g/ml$. ALP activity and collagen synthesis-which are markers of the early stage of osteogenesis-in MG-63 cells were significantly increased upon the addition of the root extract compared with the addition of the leaf extract. In contrast, the leaf extract had a more stimulatory effect on mineralization-which is marker of the late stage of osteogenesis-in MG-63 cells than did the root extract. In conclusion, extracts of both leaves and roots of R. crispus stimulated the bone-forming activity of osteoblasts; in particular, the root extract was more effective in the early stage of osteoblast differentiation, while the leaf extract was more effective in the late stage. This difference in anabolic activity may be due to differences in the constituents of the leaves and roots. The leaves and roots of R. crispus appear to complement each other as stimulators of bone formation.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.123-129
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• 2021

Purpose: The purpose of this study was to investigate antifungal activity of shiitake mushroom yeast and hyphal type of Candida albicans. Materials and Methods: The extract from shiitake mushroom was collected by drying the supernatant after soaking shiitake mushrooms in water or ethanol. The antifungal activity of the extracts against yeast type of C. albicans was investigated by the susceptibility assay using microplate. C. albicans biofilm was formed on 12-well plate using Ham's F-12 medium in CO₂ incubator and treated with the ethanol extract. Furthermore, C. albicans biofilm was formed on denture base resin disk and treated with or without the ethanol extract in the presence of denture cleanser. Live C. albicans in biofilm was counted by cultured colony forming unit value after inoculated on agar plate. Results: Ethanol extract from shiitake mushroom showed stronger antifungal activity against yeast type of C. albicans compared to its water extract. The ethanol extract significantly reduced count of C. albicans in hyphal biofilm (P < 0.05). Also, the ethanol extract showed synergistically antifungal effect with denture cleanser on candidal biofilm on denture base resin disk (P < 0.05). Conclusion: The ethanol extract of shiitake mushroom may be a candidate for preventing candidal stomatitis as well as denture-related stomatitis.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.218-222
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• 2021

This study aimed to investigate bacterial disinfection in drinking water using a water purifier. Water artificially inoculated with Escherichia coli and Listeria monocytogenes at various concentrations was irradiated using ultraviolet (UV)-C at a rate of 3.4 L/min in a water purifier, and the disinfection effects of UV-C were evaluated. Both E. coli and L. monocytogenes were disinfected up to 107 colony-forming units (CFU)/2.8 L by the UV-C irradiation. Additionally, morphological study using fluorescence microscopy in conjunction with live/dead staining revealed that both the bacteria species were disinfected by the UV-C irradiation. Therefore, UV-C in water purifiers can effectively kill high concentrations of bacteria in distilled water. UV irradiation (UV-C: 254 nm wavelength, irradiation dose: 40 mJ/㎠) at a flow rate of 3.4 L/min on drinking water has the potential to sterilize bacteria-contaminated drinking water, at least for 3.2×107 CFU/2.8 L of E. coli and 8.4×107 CFU/2.8 L of L. monocytogenes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.430-438
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• 2019

This study is to investigate increase immunomodulatory activity of Chungkukjang added with Dendropanax morbifera extract. There are four groups divided that Control, Dendropanax morbifera extract group, Chungkookjang group and Chungkukjang added to Dendropanax morbifera extract group which of five mouses each group. Their immunological characteristics were compared with either general Chungkukjang or non treated group in the tested male ICR mice. There were no significant difference in body weight and organ weight. In the plaque forming cell assay, Dendropanax morbifera extract 250 and 500 mg/kg groups measured significant increase over the control group. The values of lymphocytes were significantly increased in the Dendropanax morbifera extract 500 mg/kg group campared with the control group. In the general Chungkukjang 400 mg/kg added with Dendropanax morbifera extract 500 mg/kg group, total serum immunoglobulin G concentration was significantly higher than the control group and their spleen tissues observed proliferation of white puls. These results demonstrated that Chungkukjang Added with Dendropanax morbifera extract was provided enhance of immunomodulatory activity and suggest that it can be used as various functional foods, based on foods promote immune system health.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.345-349
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• 2019

In Korea, the mountainous area occupies more than 70% of the whole country, cutting of earth slope that cuts a part of the ground surface is widely used when building infrastructures such as road, railroad, and industrial complex construction. In recent years, regulations on environmental damage have become more strict, and various methods have been developed and applied. Among them, Concrete-Panel Retaining Wall technique is actively applied. Concrete-Panel Retaining Wall is a method to resist horizontal earth pressure by forming a wall by attaching a precast retaining wall to the front of the support material and increasing the shear strength of the disk through reinforcement of the support material. Soil nailing, earth bolt, and ground anchor are used as support material. Among them, ground anchor is a more aggressive reinforcement type that introduces tensile load in advance to the steel wire, and a large concentrated load acts on the front panel. This concentrated load is a factor that creates cracks in the concrete panel and reduces the durability of the retaining wall itself. In this study, steel pipe sleeves and reinforcements were purchased at the anchorage of the panel to prevent cracks, and by applying bumpy shear keys to the end of the panel, the weakness of the individual behavior of the existing grout anchors was improved. The problem of degraded landscape by exposure to front concrete of retaining wall and protrusion of anchorage was solved by the production of natural stone patterns and the construction of sections that do not protrude the anchorage. In order to verify the effectiveness of anti-crack sleeves and reinforcements used in the null, indoor testing and three-dimensional numerical analysis have been performed, and the use of steel pipe sleeves and reinforcements has demonstrated the overall strength increase and crack suppression effect of panels.

• Management & Information Systems Review
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• v.37 no.4
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• pp.141-156
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• 2018

PMO(Project Management Office) has been considered as a general approach for the successful operation of IT project. The previous studies tended to emphasize on the roles and functions of PMO in a normative way. However, in practice, since PMO is operated as a joint structure in which client firms and professional PMOs work together, it seems to be important that the implementation system of PMO should be properly formed. In this paper, it is examined whether the competence of client firms and professional PMO influence on the setup of implementation system of PMO, and also whether implementation system of PMO influence of the performance of IT project. In addition, it is also analyzed if the competence of client firms and professional PMO influence differently on the setup of implementation system of PMO, according to the degree of knowledge complementarity. As a result of this study, it is found that the competence of client firms and professional PMO influence positively on the setup of implementation system of PMO, and governance factors such as clear definition of organizational roles, responsibility, and setup of standardized processes are also important in performance of IT project. It is also shown that, if knowledge complementarity is formed with a common knowledge base between client firms and professional PMOs, Project Management Office functions effectively. In summary, for the successful performance of IT project, it seems that it is required to approach from the view point of governance in forming the implementation system of PMO and it is also important to form knowledge complementarity between client firms and professional PMOs.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.75-81
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• 2018

The effect of $Ar-N_2$ plasma treatment on Cu surface as one of solutions to realize reliable Cu-Cu wafer bonding was investigated. Structural characteristic of $Ar-N_2$ plasma treated Cu surface were analyzed using X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscope. Ar gas was used for a plasma ignition and to activate Cu surface by ion bombardment, and $N_2$ gas was used to protect the Cu surface from contamination such as -O or -OH by forming a passivation layer. The Cu specimen under high Ar partial pressure plasma treatment showed more copper oxide due to the activation on Cu surface, while Cu surface after high $N_2$ gas partial pressure plasma treatment showed less copper oxide due to the formation of Cu-N or Cu-O-N passivation layer. It was confirmed that nitrogen plasma can prohibit Cu-O formation on Cu surface, but nitrogen partial pressure in the $Ar-N_2$ plasma should be optimized for the formation of nitrogen passivation layer on the entire surface of Cu wafer.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.135-138
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• 2019

The aim of this study was to investigate the susceptibility of Mutans streptococci in both planktonic and biofilm states to erythrosine. S. mutans was cultured in brain-heart infusion (BHI) broth. Erythrosine was diluted in BHI broth and prepared at a concentration range of $0.02-10000{\mu}g/L$. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured using the microdilution method. After forming biofilms on 96-well plates, the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were measured. S. mutans was susceptible to erythrosine in both planktonic and biofilm states. MIC and MBC values were both $19.5{\mu}g/L$ for the planktonic state, while MBIC and MBEC values were $313{\mu}g/L$ and $2500{\mu}g/L$, respectively, for the biofilm state. Erythrosine ($19.5{\mu}g/L$) exhibited a bactericidal effect on S. mutans (killing 99.9%) in the planktonic state. For biofilms, erythrosine inhibited biofilm growth and eradicated 99.9% of biofilm bacteria at higher concentrations than MIC and MBC. These MBIC and MBEC concentrations are much lower than known noxious doses, and the MIC, MBC, and MBIC values were even lower than clinical concentrations.