• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.269-281
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• 2023

In this study, a new triplex real-time quantitative reverse transcription polymerase chain reaction (tqRT-PCR) assay was developed for the rapid and differential detection of three feline viral pathogens including feline calicivirus (FCV), feline herpesvirus 1 (FHV-1), and influenza A virus (IAV) in a single reaction. The assay specifically amplified three targeted viral genes with a detection limit of below 10 copies/reaction. The assay showed high repeatability and reproducibility, with intra- and inter-assay coefficients of variation of less than 1%. Based on the diagnostic results of the assay using 120 clinical samples obtained from cats with feline respiratory disease complex (FRDC)-suspected signs, the prevalence of FCV, FHV-1, or IAV was 43.3%, 22.5%, or 0%, respectively, indicating that the diagnostic sensitivity was comparable or superior to those of previously reported monoplex qRT-PCR/qPCR assays. The dual infection rate for FCV and FHV-1 was 8.3%. These results indicate that FCV and FHV-1 are widespread and that co-infection with FCV and FHV-1 frequently occur in the Korean cat population. The developed tqRT-PCR assay will serve as a promising tool for etiological and epidemiological studies of these three bacterial pathogens, and the prevalence data for three feline viruses obtained in this study will contribute to expanding knowledge about the epidemiology of FRDC in the current Korean cat population.

• Journal of the Korea Society for Simulation
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• v.32 no.4
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• pp.77-84
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• 2023

In the agricultural sector, power sources are being developed that use alternative energy sources such as electric tractors and hydrogen tractors, away from internal combustion engine tractors. As parts such as engines and transmissions used in conventional internal combustion engine tractors are replaced with motors and batteries, the center of gravity changes, and thus the risk of rollover should be considered. The purpose of this study is to analyze the overturn angle of the main parts of the electric tractor through dynamic simulation to minimize the overturn accident and to derive the optimal arrangement of parts to improve stability. A total of nine dynamics simulations were conducted by designing three components of the PTO motor, drive motor and the battery pack, and three factors of the arrangement method. As a result of the experiment, it was confirmed that Type3 Level3, in which the drive motor and the PTO motor are located at the front and rear of the tractor, and two battery packs are located in the middle of the tractor, has a high rollover angle. As a result of this study, the stability increased as the center of gravity was placed backward and located below. Future research needs to be done to find the optimal location of parts considering their performance and placement efficiency.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.389-395
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• 2023

This study evaluated the effects of gibberellic acid (GA₃) on the growth and quality of creeping bentgrass (Agrostis palustris Huds.). Experimental treatments included a No application of fertilizer and GA₃ (NFG) Control [3 N active ingredient (a.i.) g/m²], 0.3GA₃ (GA₃ 0.3 a.i. mg/m²/200 mL), 0.6GA₃ (GA₃ 0.6 a.i. mg/m²/200 mL), 1.2GA₃ (GA₃ 1.2 a.i. mg/m²/200 mL), and 2.4GA₃ (GA₃ 2.4 a.i. mg/m²/200 mL). Additionally, the study included a 1.5N+GA₃ experiment with similar GA₃ treatments combined with 1.5N a.i. g/m² : NFG, Control (3N a.i. g/m²), 1.5N+ 0.3GA₃ (1.5N a.i. g/m²+GA₃ 0.3 a.i. mg/m²/200 mL), 1.5N+0.6GA₃ (1.5N a.i. g/m²+GA₃ 0.6 a.i. mg/m²/200 mL), 1.5N+1.2GA₃ (1.5N a.i. g/m²+GA₃ 1.2 a.i. mg/m²/ 200 mL), and 1.5N+2.4GA₃ (1.5N a.i. g/m²+GA₃ 2.4 a.i. mg/m²/200 mL). Compared to the NFG, turf color index chlorophyll content was not significantly different (p< 0.05). However, shoot length in 1.2GA₃, 2.4GA₃, 1.5N+0.3GA₃, 1.5N+0.6GA₃, 1.5N+1.2GA₃, and 1.5N+2.4GA₃ treatments increased by 0.8%, 10.6%, 5.15%, 8.3%, 13.5 %, and 21.6%, respectively, compared to the control. As compared to the control, clipping yield in 1.5N+1.2GA₃ and 1.5N+2.4GA₃ treatments increased by 7.1% and 14.3 %, respectively. These results indicated that GA₃ application increased shoot length, with the 1.2GA₃ treatment showing shoot length similar to the control (3N a.i. g /m² ).

• Journal of fish pathology
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• v.36 no.2
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• pp.251-261
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• 2023

Photobacterium sp. YW2207 was isolated from rainbow trout raised in a fish farm located in Yeongwol-gun, Gangwon Province, South Korea. Based on 16S rRNA sequence analysis and phylogenetic analysis, it was confirmed that Photobacterium sp. YW2207 showed 100% similarity with Photobacterium piscicola and Photobacterium phosphoreum, and 94.6% similarity with P. damselae subsp. damselae. Biochemical analysis revealed that Photobacterium sp. YW2207 is a Gram-negative, motile bacterium with a cell size of 1.5~3×3~5 ㎛. The bacteria were cultured on nutrient agar, brain heart infusion agar, Muller-Hinton agar, tryptic soy agar, and thiosulfate citrate bile sucrose agar with NaCl concentrations ranging from 0 to 2.5%. The API50CHE and API20E tests indicated lower utilization capabilities compared to the P. damselae strains provided in the API database. Furthermore, unlike most Photobacterium species, Photobacterium sp. YW2207 presented negative for catalase test. Results from the flow cytometric measurement indicated that Photobacterium sp. YW2207 exhibited a more diverse distribution of cell sizes and had larger cell sizes compared with P. damselae subsp. damselae. Minimum inhibitory concentration tests showed that Photobacterium sp. YW2207 had low susceptibility to β-Lactam and aminoglycoside antibiotics, while having high susceptibility to tetracycline, doxycycline, and quinolone antibiotics. Pathogenicity on rainbow trout revealed that an immersion of 1×10⁵ CFU/ml did not cause mortality or clinical symptoms.

• Journal of Korean Society of Rural Planning
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• v.30 no.1
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• pp.33-42
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• 2024

The purpose of this study is to investigate the possible relationship between population migration and population inequality in rural areas. This study conducted a case study on the eup·myeon(rural)areas in Chungcheongbuk-do. First, the population migration was divided into four patterns, and the characteristics of population migration in rural areas were analyzed based on the net migration. The analysis results showed that there was serious migration between rural areas, and the population in rural areas mainly moved out to urban areas within the province, but the urban population outside the province moved out to rural areas. The main areas of population inflows included areas such as Deoksan-eup, Jincheon-gun, Osong-eup and Ochang-eup, Cheongju-si. Second, the Theil index was used to quantitatively analyze the level of population inequality between rural areas. The Theil index of the population aged 0~14 increased from 0.38 to 0.53, that of population aged 15-64 increased from 0.22 to 0.30, and that of population aged over 65 increased from 0.07 to 0.09, indicating an increase in population inequality. Finally, due to the continued large-scale inflows of population into Osong-eup and Ochang-eup, the Theil index of total population in Cheongju-si increased from 0.13 in 2009 to 0.23 in 2020, which meant that the level of population inequality had increased. Similarly, due to the continued large population inflows into Deoksan-eup, the Theil index of total population in Jincheon-gun increased from 0.14 in 2009 to 0.18 in 2020, which meant that the level of population inequality had increased. In conclusion, large-scale population inflows into specific areas will lead to an increase in the level of population inequality.

• Animal Bioscience
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• v.37 no.3
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• pp.471-480
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• 2024

Objective: The objective of this study was to investigate the regulation relationship of Ten-eleven translocation 1 (Tet1) in DNA demethylation and the proliferation of primordial germ cells (PGCs) in chickens. Methods: siRNA targeting Tet1 was used to transiently knockdown the expression of Tet1 in chicken PGCs, and the genomic DNA methylation status was measured. The proliferation of chicken PGCs was detected by flow cytometry analysis and cell counting kit-8 assay when activation or inhibition of Wnt4/β-catenin signaling pathway. And the level of DNA methylation and hisotne methylation was also tested. Results: Results revealed that knockdown of Tet1 inhibited the proliferation of chicken PGCs and downregulated the mRNA expression of Cyclin D1 and cyclin-dependent kinase 6 (CDK6), as well as pluripotency-associated genes (Nanog, PouV, and Sox2). Flow cytometry analysis confirmed that the population of PGCs in Tet1 knockdown group displayed a significant decrease in the proportion of S and G2 phase cells, which meant that there were less PGCs entered the mitosis process than that of control. Furthermore, Tet1 knockdown delayed the entrance to G1/S phase and this inhibition was rescued by treated with BIO. Consistent with these findings, Wnt/β-catenin signaling was inactivated in Tet1 knockdown PGCs, leading to aberrant proliferation. Further analysis showed that the methylation of the whole genome increased significantly after Tet1 downregulation, while hydroxyl-methylation obviously declined. Meanwhile, the level of H3K27me3 was upregulated and H3K9me2 was downregulated in Tet1 knockdown PGCs, which was achieved by regulating Wnt/β-catenin signaling pathway. Conclusion: These results suggested that the self-renewal of chicken PGCs and the maintenance of their characteristics were regulated by Tet1 mediating DNA demethylation through the activation of Wnt4/β-catenin signaling pathway.

• Journal of Adhesion and Interface
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• v.25 no.1
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• pp.157-161
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• 2024

Amphiphilic gold nanoparticles, synthesized by the simultaneous binding of hydrophilic and hydrophobic ligands on their surfaces, find diverse applications in energy, bio, optical, electronic technologies, and various other fields. Particularly, these amphiphilic gold nanoparticles possess both hydrophilic and hydrophobic characteristics, enabling them to activate interface at the interface of immiscible fluids and form organized structures. The surface properties of gold nanoparticles play a crucial role in influencing the behaviors of amphiphilic gold nanoparticles at the interface of two fluids. Therefore, this study investigated the adsorption behaviors of gold nanoparticles at the organic solvent-water interface based on the surface characteristics of amphiphilic gold nanoparticles and the type of organic solvents. It was observed that the amount of adsorbed gold nanoparticles at the interface increased with the length of hydrocarbon chains in hydrophobic ligands and increased with shorter hydrocarbon chains in the organic solvent. Furthermore, using the Langmuir isotherm model, the study confirmed the formation of a monolayer by amphiphilic gold nanoparticles and obtained significant thermodynamic parameters simultaneously.

• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.143-152
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• 2024

This study was conducted to evaluate the growth and nutrient dynamics in response to fertilization of four tree species (LT: Liriodendron tulipifera L.; PY: Prunus yedoensis Matsumura; QA: Quercus acutissima Ca rruth; a nd PT: Pinus thunbergii Parl.) planted in a fire-disturbed urban forest in Bongdaesan (Mt.), Ulsan Metropolitan Area, South Korea. The trees were planted in 2009, and compound fertilizers (N₆P₄K₁) were applied in April 2013 and March 2014. Tree growth, soil, and foliage nutrients were examined from March 2013 to October 2016. The regression coefficients for the increment of the diameter at breast height (DBH) significantly differed between the fertilized and unfertilized plots, suggesting the significant effects of fertilization. By contrast, fertilization did not affect the coefficients for height increments. Regarding soil nutrient contents, organic carbon and total nitrogen concentrations were lower in the fertilized plots than in the unfertilized plots, whereas available phosphorus, exchangeable calcium, and magnesium concentrations were higher in the fertilized plots than in the unfertilized plots. In foliage, nitrogen and phosphorus concentrations were higher in the fertilized plots than in the unfertilized plots, whereas potassium, calcium, and magnesium concentrations were not affected by fertilization. Nutrient concentration of foliage among the tree species were higher in LT and PY than in QA and PT. These results suggest that fertilizers may be used to enhance soil fertility and the growth and nutrient status of tree species planted in a fire-disturbed urban forest.

• Journal of Advanced Technology Convergence
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• v.3 no.2
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• pp.25-31
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• 2024

In recent industrialization and development due to information and communication technology, modern women in modern society are exposed to physical and mental health due to numerous stresses. Popular inflammations are attributable to a decrease in lactic acid bacteria, frequent antibiotic use, and a decrease in immunity. It is necessary to develop products that are helpful and reflected. The inner care gel currently introduced on the market can increase beneficial bacteria and maintain a healthy y-zone. The inner gel contains a hydrogel component. 90% is made up of water, and other components act as support for supporting water and are formed through crosslinking between polymer chains. Hydroxyethyl cellulose (HEC) is a hydroxyethyl ethylenetel of cellulose. The purpose of use is to act as a binder, an emulsion stabilizer, a viscosity enhancer (water-soluble), and a film forming agent. CA (crosslinker) is a crosslinking agent and serves to bind. Hydrogel in the beauty field acts as a film forming agent that gently wraps around the skin by forming a thin film and serves as an emulsion stabilizer that helps to prevent separation of other raw materials. It also acts as a thickener by increasing viscosity in cosmetics. In addition, it is used for glucose monitoring, nursing care, cell transplantation, and wound treatment in the bio field. Currently, it is understood that no products using functional hydrogel have been released, so in this study, a Y zone care hydrogel solution was manufactured to find out the antibacterial properties of the functional hydrogel, and a new solution was developed. As a result, it was confirmed that the appropriate Ph was applied to the Y zone, and after culturing Candida albicans in PDB medium, all three products of the Y zone care hydrogel solution showed an antibacterial effect of 0.5-1.0mm

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.4
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• pp.165-171
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• 2006

This is the research to prepare a purification program for relatively less polluted stream by using phytoremediation. We calculated a treatment amount of nutrients followed by growth of Helianthus annuus (a kind of sunflower), setting up the plant reactor in the hothouse. Moreover, to investigate a field applicability, we could find increased contents of nitrogen, carbon and hydrogen in plants by setting up a H. annuus planted artificial floating island in an irrigation canal. When we changed the dissolved inorganic nitrogen(DIN) concentration of the influent from 28.5 to 199.2 mg/l and the dissolved inorganic phosphorus(DIP) concentration of the influent from 13.3 to 25.4 mg/l, growth disorder has not appeared though it is much higher than the criterion of water for irrigation. In this case, the removal rate of DIN was $81.7\sim98.6%$, and that of DIP was $81.9\sim98.4%$ in 3 days stay on average. It has appeared that the efficient hydraulic retention time(HRT) was 48 hours. The following contents of nitrogen, carbon and hydrogen of H. annuus appeared in the artificial floating island: nitrogen was $3.2\sim7.8%$ in the trunk and $3.0\sim6.3%$ in the root. Carbon was $40.1\sim57.7%$ in the trunk and $43.4\sim53.8%$ in the root.