• Journal of Marine Life Science
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• v.7 no.2
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• pp.180-186
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• 2022

This study was conducted to investigate the effects of different salinity on growth, survival and hematological parameters of juvenile chum salmon (Oncorhynchus keta). The fish were tested at salinity 0, 10, 20 and 30‰ for 30 days with three replicated groups. After the 30 days, the survival rate was 87.5% or more for 0, 10, 20‰ and significantly decreased to 75% at 30‰. Weight gain, specific growth rate, feed efficiency, daily feed intake, daily protein intake and protein efficiency ratio were the highest at 10‰. In the plasma components, the alanine aminotransferase (ALT) was significantly decreased at 10, 20 and 30‰ in compared with 0‰, whereas sodium (Na⁺) and chloride (Cl^-) was significant increased and there was no significant change in the total protein (TP) and potassium (K⁺). In conclusion, the optimal salt concentration for the growth of juvenile chum salmon (11~33 g) was confirmed to be 10‰, but the association with the change in blood composition should be further studied.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.165-170
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• 2022

If petroleum- derived plastic like a bio-based plastic was degradation, awareness like a global warming and environmental disasters will be decreased. Plastic film was produced by adding ferric ions according to concentration by using a pro-oxidant in polyolefin resin. Changes in tensile strength, elongation, and molecular weight were evaluated according to the UV irradiation time. Increasing the amount of ferric ions resulted in more significant declines of physical properties, and also resulted in greater changes in molecular weight. After 100 hours of UV irradiation, tensile strength declined significantly in the film containing pro-oxidant as compared to the control. A similar effect was also observed in terms of elongation. The film containing pro-oxidant showed a 73.8% decrease in molecular weight after 100 hours of UV irradiation. The appropriate use of pro-oxidant can not only degrade plastic film but also control the time of degradation at the petroleum-derived plastic films. Further studies are necessary to investigate the conditions of plastic film degradation.

• Journal of Veterinary Science
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• v.21 no.5
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• pp.80.1-80.13
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• 2020

Background: In suckling piglets, transmissible gastroenteritis virus (TGEV) causes lethal diarrhea accompanied by high infection and mortality rates, leading to considerable economic losses. This study explored methods of preventing or inhibiting their production. Bovine antimicrobial peptide-13 (APB-13) has antibacterial, antiviral, and immune functions. Objectives: This study analyzed the efficacy of APB-13 against TGEV through in vivo and in vitro experiments. Methods: The effects of APB-13 toxicity and virus inhibition rate on swine testicular (ST) cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). The impact of APB-13 on virus replication was examined through the 50% tissue culture infective dose (TCID₅₀). The mRNA and protein levels were investigated by real-time quantitative polymerase chain reaction and western blot (WB). Tissue sections were used to detect intestinal morphological development. Results: The safe and effective concentration range of APB-13 on ST cells ranged from 0 to 62.5 ㎍/mL, and the highest viral inhibitory rate of APB-13 was 74.1%. The log₁₀TCID₅₀ of 62.5 ㎍/mL APB-13 was 3.63 lower than that of the virus control. The mRNA and protein expression at 62.5 ㎍/mL APB-13 was significantly lower than that of the virus control at 24 hpi. Piglets in the APB-13 group showed significantly lower viral shedding than that in the virus control group, and the pathological tissue sections of the jejunum morphology revealed significant differences between the groups. Conclusions: APB-13 exhibited good antiviral effects on TGEV in vivo and in vitro.

• Food Science of Animal Resources
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• v.43 no.3
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• pp.402-411
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• 2023

This study was conducted to investigate the bactericidal effect of nisin (Nisin) only, atmospheric pressure plasma (APP) only, and a combination of APP and nisin (APP+Nisin)(APP+Nisin) on beef jerky and sliced ham inoculated with Escherichia coli O157:H7, gram-negative bacteria. The bactericidal effect against E. coli O157:H7 and Listeria monocytogenes was confirmed using a nisin solution at a concentration of 0-100 ppm, and APP+Nisin was tested on beef jerky and sliced ham using 100 ppm nisin. Beef jerky and sliced ham were treated with APP for 5 min and 9 min, respectively. In the bacterial solution, 100 ppm nisin out of 0-100 ppm nisin exhibited the highest bactericidal activity against L. monocytogenes (gram-positive bacteria; p<0.05); however, it did not exhibit bactericidal effects against E. coli O157:H7 (gram-negative bacteria). The APP+Nisin APP+Nisin exhibited a 100% reduction rate in both E. coli O157:H7 and L. monocytogenes compared to the control group, and was more effective than the Nisin. The APP+Nisin decreased the number of colonies formed by 0.80 and 1.96 Log CFU/g for beef jerky and sliced ham, respectively, compared to the control, and exhibited a higher bactericidal effect compared to the Nisin (p<0.05). These results demonstrate the synergistic bactericidal effect of APP and nisin, providing a possible method to improve the limitations of nisin against gram-negative bacteria. In addition, this technology has the potential to be applied to various meats and meat products to control surface microorganisms.

• Development and Reproduction
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• v.12 no.3
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• pp.275-281
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• 2008

Endocrine disrupting chemiclas (EDCs) such as bisphenol A (BPA) and nonylphenol (NP) have estrogenic activity and can alter reproduction in fish. In the present study, the effects of BPA and NP on in vitro steroid production from oocytes of maturation stage (oocyte diameter$\fallingdotseq$1.88 mm) from the greenling (Hexagrammos agrammus) were evaluated. Oocytes were incubated with different concentrations of BPA and NP (0.1, 1, 10, 100 and 1,000 ng/$m{\ell}$) in the presence or absence of 50 IU human chorionic gonadotropin (HCG) for 48 hours. After incubation, levels of $17{\alpha},\;20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}OHP$), estradiol-$17{\beta}(E_2)$ and testosterone (T) from incubated media were quantified by radioimmunoassay (RIA). In BPA treatment, 100 ng/$m{\ell}$ of BPA stimulated $E_2$ production regardless HCG supplement. Every concentration of BPA inhibited T production without HCG although 0.1 ng/$m{\ell}$ of BPA stimulated T production with HCG. In NP treatment, 10 ng/$m{\ell}$ of NP stimulated $17{\alpha}20{\beta}OHP$ and T production without HCG. 1 ng/$m{\ell}$ of NP inhibited $E_2$ production. Taken toghther, these results suggest that BPA might have weak estrogen-agonistic effect and NP has estrogenantagonistic effect at final oocyte maturation stage of H. agrammus.

• Journal of Life Science
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• v.33 no.5
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• pp.383-390
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• 2023

The goal of this study was to identify new bioactive peptides in extracts derived from Tenebrio molitor (T. molitor) larvae for the development of functional foods. After extraction from freeze-dried T. molitor larvae with various solvents on time course, the extracts showed the highest 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity at 5 and 10 hr per total protein and solid contents, respectively. When the water extract was fractionated, a high methanol concentration led to a reduced level of high-molecular-weight proteins in the centrifugal supernatant, whereas increased DPPH activity in the supernatants suggests low-molecular-weight peptides may mediate antioxidant activity in the supernatant. Most of the organic solvent partitions, excluding butanol, showed similar activities in the water phases, and the organic solvent partition fraction exhibited a 28~44% decrease in activity following heat treatment, implying that some components in the fraction become unstable in the presence of heat. The addition of proteinase K to the water extract increased DPPH activity by 10~20%, suggesting that peptides, when released from total proteins, partially increase antioxidant activity. Therefore, we suggest that the antioxidants in T. molitor larval extracts make them a potential source of functional animal food.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.2
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• pp.105-114
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• 2018

The aim of this study was to evaluate the change of phenolic compounds after phosphite treatment on Cheorwon onion. Onion is a perennial plant belonging to the lily family. It is native to Persia of Southwest Asia. It is widely cultivated in the temperate regions of the world. Onion is a good name for the 'Okchong' to drop blood cholesterol and cardiovascular blood flow to increase the prevention of adult diseases. Cheorwon area is inland, but it has high continental climate due to its high altitude. Therefore it is said that the onion cultivated in this region has higher sugar content and higher taste than onion grown in the southern region. Phosphorus components are particularly important ingredients for promoting muscle development. However, if the phosphoric acid content of the soil part is maintained to a large extent until the harvest, the competition of the nutrients tends to cause decay of the root part. Therefore, it is important to improve the quality and shelf life of onion by inducing nutrient balance by applying foliar fertilization method on the reducing phosphorus at harvest time. In this study, acidity was controlled by diluting phosphorous acid(H₃PO₃) and potassium hydroxide(KOH), followed by leaf surface treatment with phosphite on onion. In this study, the concentration of phosphite was diluted to 500, 1,000, 1,500ppm and sprayed three times over the onion leaves in May 2018 using an atomizer and harvested at the end of June, and the phenolic compounds were analyzed by HPLC. As a result, the content of quercetin, one of the important substances in onion, was phosphite 500ppm(179.70㎍/g), 1,000(150.27), 1,500(105.95). The contents of caffeic acid, p-coumaric acid, ferulic acid, rutin, kaempferol, and sugar content were higher in the treatments than in the control. Therefore, the phosphite does not have a great influence on the growth, but it may play a role as a method of achieving balance with nitrogen in the rainy season by supplying the role of the material catalyst and the water soluble phosphoric acid and the potassium in the influence of the material change.

• 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 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 the Korea Society of Computer and Information
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• v.29 no.1
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• pp.187-194
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• 2024

In this study, we examined the effects of Rubus crataegifolius leaf on the inhibition of differentiation and adipogenesis of 3T3-L1 preadipocytes to confirm their potential for use as an anti-obesity functional material. Rubus crataegifolius leaves water extracted using hot water were then concentrated for use, with an extract yield of 4.76%. The result of measuring the rate of 3T3-L1 cell survival of Rubus crataegifolius leaf extract (RCLE) showed growth inhibition of 13% at a concentration of 1,000 ㎍/mL. Thus, in this study, experiments were performed using RCLE treatment concentrations up to 500 ㎍/mL. Production of triglycedie in 3T3-L1 cells showed a dose-dependent decrease, and the rate of reduction was 28.7, 40.8, and 51.6% at concentrations of 100, 300, and 500 ㎍/mL, respectively, compared to the control group. In addition, the results confirmed that suppression of lipogenesis was achieved by suppressing the expression of peroxisome proliferator-activated receptor γ (PPAR γ), CCAAT/enhancer-binding protein α (C/EBP α), sterol regulatory element-binding protein-1c (SREBP-1c), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and increasing the expression of p-activated protein kinase (p-AMPK). Based on these results, it is believed that Rubus crataegifolius leaf extract can be used in the effort to manage obesity by regulating factors related to adipocyte differentiation and adipogenesis.