• Korean Journal of Veterinary Service
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• v.42 no.1
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• pp.31-37
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• 2019

There have been a total tenth FMD outbreaks in Korea and for the first time, type O and A were detected simultaneously in 2017, which led to difficulties in FMD control. For the effective prevention of FMD, the importance of discrimination of serotypes became greater. Therefore, the most urgent requirement in case of FMD outbreak is differential diagnosis of serotypes. In this study, we developed a PNA probe-mediated multiplex real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay using the peptide nucleic acid (PNA) probe, which is known to be stable to nucleotide mutation and that could specifically detect the all FMDV serotype A, FMDVA Yeoncheon strain which was occurred in Korea in 2017, and FMDV A viruses shown 96% similarity with FMDVA/Yeoncheon strain, at the same time. Therefore, It is believed that the newly introduced FMDVA will be effectively diagnosed using the PNA probe multiplex RT-PCR developed in this study, and ultimately contribute to the prevention of FMD.

• Korean Journal of Labor Studies
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• v.19 no.1
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• pp.177-211
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• 2013

The Chinese dual structure of employment('Shuangguizhi') has been retained through the Economic Reforms, and has been supported and reproduced by the system of division between rural and urban household registration. In the 2000s, efforts of the government to abolish the division appeared to be effective with the introduction of the 'Labor Contract Act'. However, the eclecticism of the Act and the outbreak of the global financial crisis in 2008 gave new momentum to the revival of the Chinese dual structure of employment by increasing the scale of labor dispatching. Labor dispatching in China has become a regular form of employment rather than an exceptional one. Labor dispatching reveals its Chinese characteristics against the particular background formed during the periods of state-owned-enterprise restructuring around 2000. The combined effects of the 'Labor Contract Act' and the global financial crisis brought about the effect of increase rather than control of labor dispatching, and gave a signal to enterprises to use various forms of labor dispatching including 'reverse directional labor dispatching' to lessen burdens and costs caused by the Act and the crisis. As labor dispatching strengthens or displaces the existing dual structure of employment, social groups which need more social protection tend to be much more excluded from the protection of the government and the society.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.1-11
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• 2021

In this review, recent foodborne outbreaks caused by viruses in the Republic of Korea (2010-2019) were analyzed. The human norovirus was found to be the major foodborne virus causing an average of 94.9% of the viral outbreaks. Reverse-transcription polymerase chain reaction (PCR) with electrophoresis has been widely used to detect viruses, but several rapid detection methods, including real-time PCR, multiplex PCR, and quantum dot assay, have also been suggested. For norovirus inactivation studies, surrogates such as murine norovirus and feline calicivirus have been widely used to identify the reduction rate owing to the limitations in laboratory cultivation. Conversely, direct cell infection studies have been conducted for other foodborne viruses such as adenovirus, astrovirus, rotavirus, and hepatitis A or E virus. Moreover, virucidal mechanisms using various physical and chemical treatments have been revealed. These recent studies suggest that rapid in situ detection and effective control are valuable for ensuring food safety against viral infections.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.31-39
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• 2022

The purpose of this study was to investigate the whitening effects of hot water (AMPW) and ethanol (AMPE) extracts of Mangifera indica L. peel. To verify the whitening effects, tyrosinase inhibitory activity was measured. 9.51% inhibitory activity, and 35.98% inhibitory activity at 1,000 ㎍/ml. The effects of AMPW and AMPE on cell viability were measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in B16-F10 melanoma cells. Greater than 95% cell viability was observed at 100 ㎍/ml. Thus, subsequent experiments were performed at concentrations less than 100 ㎍/ml. The whitening effects were confirmed by measuring the protein and mRNA expression levels of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein 1 (TRP-1), and TRP-2, which are factors involved in melanin synthesis. Western blotting and reverse transcription-polymerase chain reaction results confirmed that 100 ㎍/ml AMPW and AMPE showed superior inhibitory effects than the control treatment (alpha-melanocyte stimulating hormone only). Therefore, Mangifera indica L. peel extract had a whitening effect, and thus, has potential as a natural material for use in cosmetics.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.537-542
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• 2022

There is a limit to the current indoor air quality (IAQ) monitoring method using fixed sensors and devices. A mobile robot for IAQ monitoring was developed by mounting IAQ monitoring sensors on a small multi-legged robot to minimize vibration and protect the sensors from vibration while robot moves. The developed mobile robot used a simple gait mechanism to enable the robot to move forward, backward, and turns only with the combination of forward and reverse rotation of the two DC motors. Due to the simple gait mechanism, not only IAQ data measurements but also gait motion control were processed using a single Arduino board. Because the mobile robot has small number of electronic components and low power consumption, a relatively low-capacity battery was mounted on the robot to reduce the weight of the battery. The weight of mobile robot is 1.4kg including links, various IAQ sensors, motors, and battery. The gait and turning speed of the mobile robot was measured at 3.75 cm/sec and 14.13 rad/sec. The maximum height where the robot leg could reach was 33 mm, but the mobile robot was able to overcome the bumps up to 24 mm.

• Journal of Korean Medicine for Obesity Research
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• v.23 no.1
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• pp.1-9
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• 2023

Objectives: Noni fruit juice (NFJ) is liquor extracted from Morinda citrifolia (noni) fruit and has been used as an herbal remedy in many countries. However, the NFJ's anti-adipogenic and anti-inflammatory effects on adipocytes are poorly understood. The purpose of this study was to explore the commercially standardized NFJ effects on lipid accumulation throughout 3T3-L1 preadipocytes differentiation and interleukin-1β (IL-1β)-mediated inducible nitric oxide synthase (iNOS) expression in 3T3-L1 preadipocytes. Methods: Cellular lipid accumulation and triglyceride (TG) content in differentiating 3T3-L1 preadipocytes were assessed subsequently via the Oil Red O staining and AdipoRed assay. MTS assay was used to examine NFJ cytotoxicity in (differentiating) 3T3-L1 preadipocytes. Immunoblotting and reverse transcriptase polymerase chain reaction analysis were used to measure the expression levels of target protein and mRNA in (differentiating) 3T3-L1 preadipocytes, respectively. Results: NFJ treatment at 150 μL/mL led to a substantial reduction of fat accumulation and TG content during 3T3-L1 adipogenesis with no discernable impact on the cell viability. Of note, while NFJ treatment (150 μL/mL) largely inhibited the CCAAT/enhancer-binding protein-α (C/EBP-α) and peroxisome proliferator-activated receptor-β (PPAR-β) protein expressions, it did not influence PPAR-γ in differentiating 3T3-L1 preadipocytes. Of interest, treatment with IL-1β at 20 ng/mL for 4 hours elicited in firm induction of iNOS mRNA expression in 3T3-L1 preadipocytes. However, NFJ treatment at 100 or 200 μL/mL greatly attenuated the IL-1β-induced iNOS mRNA expression in 3T3-L1 preadipocytes. Conclusions: NFJ has anti-adipogenic and anti-inflammatory effects on (differentiating) 3T3-L1 preadipocytes which are in part intervened via control of the expression of C/EBP-α, PPAR-β, and iNOS.

• Animal Bioscience
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• v.36 no.9
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• pp.1336-1349
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• 2023

Objective: The study was conducted to screen differentially expressed miRNAs in sows at early pregnancy by high-throughput sequencing and explore its mechanism of action on embryo implantation. Methods: The blood serum of pregnant and non-pregnant Landrace×Yorkshire sows were collected 14 days after artificial insemination, and exosomal miRNAs were purified for high throughput miRNA sequencing. The expression patterns of 10 differentially expressed (DE) miRNAs were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR quantified the abundance of serum exosomal miR-192 in pregnant and control sows, and the diagnostic power was assessed by receiver operating characteristic (ROC) analysis. The target genes of DE miRNAs were predicted with bioinformatics software, and the functional and pathway enrichment analysis was performed on gene ontology and the Kyoto encyclopedia of genes and genomes terms. Furthermore, a luciferase reporter system was used to identify the target relation between miR-192 and integrin alpha 4 (ITGA4), a gene influencing embryo implantation in pigs. Finally, the expression levels of miRNAs and the target gene ITGA4 were analyzed by qRT-PCR, and western blot, with the proliferation of BeWo cells detected by cell counting kit-8 (CCK-8). Results: A total of 221 known miRNAs were detected in the libraries of the pregnant and non-pregnant sows, of which 55 were up-regulated and 67 were down-regulated in the pregnant individuals compared with the non-pregnant controls. From these, the expression patterns of 10 DE miRNAs were validated. The qRT-PCR analysis further confirmed a significantly higher expression of miR-192 in the serum exosomes extracted from pregnant sows, when compared to controls. The ROC analysis revealed that miR-192 provided excellent diagnostic accuracy for pregnancy (area under the ROC curve [AUC]=0.843; p>0.001). The dual-luciferase reporter assay indicated that miR-192 directly targeted ITGA4. The protein expression of ITGA4 was reduced in cells that overexpressed miR-192. Overexpression of miR-192 resulted in the decreased proliferation of BeWo cells and regulated the expression of cell cycle-related genes. Conclusion: Serum exosomal miR-192 could serve as a potential biomarker for early pregnancy in pigs. miR-192 targeted ITGA4 gene directly, and miR-192 can regulate cellular proliferation.

• Analytical Science and Technology
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• v.21 no.6
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• pp.518-525
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• 2008

Mandipropamid is a new mandelamide-type fungicide to control foliar Oomycete pathogens in some vegetables. An analytical method was developed to determine mandipropamid residues in agricultural commodities using high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Mandipropamid was extracted with methanol from grape, tomato, green pepper, Chinese cabbage and potato samples. The extract was diluted with saturated sodium chloride solution and distilled water, and dichloromethane partition was followed to recover the mandipropamid from the aqueous phase. Florisil column chromatography was employed to further remove interfering co-extractives prior to HPLC analysis. Reverse-phased HPLC was successfully applied to determine mandipropamid in sample extracts with the detection at its ${\lambda}_{max}$ (223 nm). Overall recoveries of mandipropamid from fortified samples averaged $99.8{\pm}1.7$ (n=6), $89.3{\pm}5.3$ (n=6), $98.7{\pm}2.2$ (n=6), $99.7{\pm}6.8$ (n=6) and $91.1{\pm}3.1$ (n=6) for grape, tomato, green pepper, Chinese cabbage and potato, respectively. Limit of quantification of the method was 0.02~0.04 mg/kg for all samples. A LC/mass spectrometry with selected-ion monitoring was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to determine the terminal residue of mandipropamid in agricultural commodities.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.46-46
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• 2021

The first purpose of this study was to evaluate the scavenging capacity (SC) of DPPH and ABTS free radicals for ethanol extract (STR-E) and its active fractions from Sophora tonkinensis root (STR). Four different fractions from STR-E were prepared by using different types of solvents such as chloroform (STR-E-C), ethyl acetate (STR-E-EA), n-butanol (STR-E-B), and water (STR-E-W). STR-E-C showed the highest value of total phenolic content, while STR-E showed the highest value of total flavonoid and terpenoid content. In STR-E and its four fractions, STR-E-EA showed the strongest SC with the lowest SC50 values of the DPPH radicals and ABTS radicals. The second purpose of this study was to evaluate anti-inflammatory activity in the lipopolysaccharide (LPS)-induced RAW 264.7 macrophages treated with STR-E, STR-E-C, and STR-E-EA, respectively. No cytotoxic effect to RAW 264.7 cells was observed at 20 ~ 25 ㎍/ml of STR-E, 10 ㎍/ml of STR-E-C, and 5 ㎍/ml of the STR-E-EA, presenting cell viability values close to that of the untreated control (100%). STR-E, STR-E-C, and STR-E-EA significantly suppressed the LPS-induced nitric oxide (NO) in a dose-dependent manner. Results of reverse-transcription (RT)-qPCR analysis showed that the peak mRNA levels of IL-1β, TNF-α, iNOS, IL-6, and IL-10 were observed in the LPS-stimulated macrophages at 4 h, 2 h, 12 h, 12 h, and 12 h, respectively. The peak mRNA levels of IL-1β, TNF-α, iNOS, and IL-6 were significantly reduced in the LPS-stimulated macrophages co-treated with 20 ㎍/ml and 25 ㎍/ml of STR-E, respectively. In the case of IL-10, its peak mRNA level slightly increased without statistical significance. Compared with the LPS-stimulated macrophages, the peak mRNA levels of IL-1β, TNF-α, iNOS, and IL-6 reduced in the LPS-stimulated macrophages co-treated with 10 ㎍/ml and 20 ㎍/ml of STR-E-C, respectively. In contrast, the peak mRNA level of IL-10 significantly increased at 8 h. Compared with the LPS-stimulated macrophages, the peak mRNA levels of IL-1β, TNF-α, iNOS, and IL-6 reduced in the LPS-stimulated macrophages co-treated with 5 ㎍/ml and 10 ㎍/ml of STR-E-EA, respectively. In contrast, the peak mRNA level of IL-10 increased at 4 h. Taken together, our data indicated that STR-E, STR-E-C, and STR-E-EA activate macrophages to secrete both pro-inflammatory and anti-inflammatory cytokines.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.165-174
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• 1998

The turnover of collagen is controlled by the balance between collagen synthesis and degradation. The production of collagenase (matrix metalloproteinase-1) and its inhibitor, tissue inhibitor of matrix metallopmteinase-1 (TIMP-1) are one of the substances which regulate this balance. The periodontal ligament fibroblast plays an important role in collagen metabolism during orthodontic treatment and is believed to be an origin of the osteoblast in the alveolar bone. The collagenase secreted by the periodontal ligament fibroblast and the osteoblast initiates the bone resorption by removing the osteoid layer in the alveloar bone. The interleukin-$1{\beta}$ is secreted by the macrophage during orthodontic treatment. The present study was undertaken to assess the effect of mechanical stress and interleukin-$1{\beta}$ on the expression of collagenase and TIMP-1 in the periodontal ligament fibroblasts using reverse transcription polymerase chain reaction and immunohistochemical staining. The periodontal ligament fibroblasts were stitched by placing the $Petriperm dish^{\circledR}$ dish on the top of spheroidal convex watch glass ($5\%$ surface increase) and tented with interleukin-$1{\beta}$ (1.0 ng/ml), or treated with both of them. Treatment with mechanical stress and/or interleukin-$1{\beta}$ resulted in increased collagenase mRNA expression. The mechanical stress treated group (1.61, 1.62, 1.37 fold increase), the interleukin-$1{\beta}$, tented group (1.68, 1.60, 3.78 fold increase), the mechanical stress and interleukin-$1{\beta}$ treated group (1.89, 1.72, 5.48 fold increase) induced increases in collagenase mRNA compared with the control group after 2, 4, 8 hours respectively. But TIMP-1 mRNA expressions at experimental groups were decreased after 2, 4 hours and increased after 8 hours. The mechanical stress treated group (0.16, 0.49 fold decrease and 3.77 fold increase), the interleukin-$1{\beta}$ treated group (0.15,0.44 fold decrease and 4.46 fold increase), the mechanical stress and interleukin-$1{\beta}$ tented group (0.15, 0.69 fold decrease and 4.81 fold increase) induced changes in TIMP-1 mRNA compared with the control group after 2, 4, 8 hours, respectively. Immunohistochemical stain showed that increased collagenase and TIMP-1 staining of the mechanical stress tented group, the interleukin-$1{\beta}$ treated group, and the mechanical stress and interleukin-$1{\beta}$ treated group compared with that of the control group after 8 hours. These findings suggest that mechanical stress and interleukin-$1{\beta}$ regulate expression of collagenase and TIMP-1.