• Human Ecology Research
• /
• v.60 no.1
• /
• pp.1-20
• /
• 2022

This paper presents a social network analysis of changes in Home Economics education content loaded on YouTube before and after the outbreak of COVID-19. From January 1, 2008 to June 30, 2021, a basic analysis was conducted of 761 Home Economics education videos loaded on YouTube, using NetMiner 4.3 to analyze important keywords and the centrality of video titles and full texts. Before COVID-19, there were 164 Home Economics education videos posted on YouTube, increasing significantly to 597 following the emergence of the pandemic. In both periods, there was more middle school content than high school content. The content in the child-family field was the most, and the main keywords were youth and family. Before COVID-19, a performance evaluation indicated that the proportion of student content was high, whereas after the outbreak of the disease, teacher content increased significantly due to the effect of distance learning. However, compared with video use, the self-expression and participation of users were lower in both periods. The centrality analysis indicated that in the title, 'family' exhibited a high degree of both centrality and eigenvector centrality over the entire period. Degree centrality of the video title was found to be high in the order of class, online, family, management, etc. after the outbreak of COVID-19, and the connection of keywords was strong overall. Eigenvector centrality indicated that career, search, life, and design were influential keywords before COVID-19, while class, youth, online, and development were influential keywords after COVID-19.

• Animal Bioscience
• /
• v.35 no.6
• /
• pp.892-901
• /
• 2022

Objective: This study was performed to investigate the potential effect of wheat phytase on long-chain inorganic polyphosphate (polyP)-mediated interleukin 8 (IL-8) signaling in an intestinal epithelial cell line, HT-29 cells. Methods: Cell viability and the release of the pro-inflammatory cytokine IL-8 in HT-29 cells exposed to polyP1150 (average of 1,150 phosphate residues) treated with or without wheat phytase were measured by the EZ-CYTOX kit and the IL-8 ELISA kit, respectively. Also, the activation of cellular inflammatory factors NF-κB and MAPK (p38 and ERK 1/2) in HT-29 cells was investigated using ELISA kits. Results: PolyP1150 negatively affected the viability of HT-29 cells in a dose-dependent manner. However, 100 mM polyP1150 dephosphorylated by wheat phytase increased cell viability by 1.4-fold over that of the intact substrate. Moreover, the 24 h exposure of cells to enzyme-treated 50 mM polyP1150 reduced the secretion of IL-8 and the activation of NF-κB by 9% and 19%, respectively, compared to the intact substrate. PolyP1150 (25 and 50 mM) dephosphorylated by the enzyme induced the activation of p38 MAPK via phosphorylation to 2.3 and 1.4-fold, respectively, compared to intact substrate, even though it had little effect on the expression of ERK 1/2 via phosphorylation. Conclusion: Wheat phytase could attenuate polyP1150-induced IL-8 release in HT-29 cells through NF-κB, independent of MAP kinases p38 and ERK. Thus, wheat phytase may alleviate inflammatory responses including hypercytokinemia caused by bacterial polyP infection in animals. Therefore, wheat phytase has the potential as an anti-inflammatory therapeutic supplement in animal husbandry.

• Advances in aircraft and spacecraft science
• /
• v.9 no.5
• /
• pp.449-462
• /
• 2022

Space-telescopes placed in the Sun-Earth second Lagrange point (L2) observe the sky following a scan strategy that is usually based on a spin-precession motion. Knowing which regions of the sky will be more observed by the instrument is important for the science operations and the instrument calibration. Computing sky observation parameters numerically (discretizing time and the sky) can consume large amounts of time and computational resources, especially when high resolution isrequired.This problem becomesmore critical if quantities are evaluated at detector level instead of considering the instrument entire Field of View (FoV). In previous studies, the authors have derived analytic solutions for quantities that characterize the observation of each point in the sky in terms of observation time according to the scan strategy parameters and the instrument FoV. Analytic solutions allow to obtain results faster than using numerical methods as well as capture detailed characteristics which can be overseen due to discretization limitations. The original approach is based on the analytic expression of the instrument trace over the sky. Such equations are implicit and thusrequiresthe use of numeric solversto compute the quantities.In this work, a new and simpler approach for computing one ofsuch quantities(mean observation time) is presented.The quantity is first computed for pure spin motion and then the effect of the spin axis precession is incorporated under the assumption that the precession motion is slow compared to the spin motion.In this sense, this new approach further simplifies the analytic approach, sparing the use of numeric solvers, which reduces the complexity of the implementation and the computing time.

• Korean Journal of Acupuncture
• /
• v.39 no.4
• /
• pp.142-151
• /
• 2022

Objectives : Parkinson's disease (PD) is a neurodegenerative disorder threatening the quality of life and highly occurred in over 65 years old. Gastrodia elata Blume (GEB), a traditional medicine used for the treatment of headache and convulsion, has been reported to have neuroprotective effect. This study was designed to investigate the neuroprotective effect of GEB and the proteomic changes in the substantia nigra (SN) of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice. Methods : Male eleven-week-old C57BL/6 mice were intraperitoneally injected with 30 mg/kg of MPTP at 24-h intervals for 5 days. Two hours after the daily MPTP injection, the mice were orally administered 800 mg/kg of GEB extract, which continued for 7 days beyond the MPTP injections, for a total of 12 consecutive days. Two hours after the final GEB administration, the brain samples were collected, and dopaminergic neuronal death and proteomic changes in the SN were evaluated. Results : GEB prevented the MPTP-induced dopaminergic neuronal death and regulated the expression of 11 proteins including thimet oligopeptidase, T-complex protein 1, glycine tRNA ligase, and pyruvate kinase isozymes M1. Conclusions : GEB prevents MPTP-induced dopaminergic neuronal death by regulating the proteins in the SN.

• Biomolecules & Therapeutics
• /
• v.31 no.2
• /
• pp.200-209
• /
• 2023

Patients with non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) amplification or sensitive mutations initially respond to the tyrosine kinase inhibitor gefitinib, however, the treatment becomes less effective over time by resistance mechanism including mesenchymal-epithelial transition (MET) overexpression. A therapeutic strategy targeting MET and EGFR may be a means to overcoming resistance to gefitinib. In the present study, we found that picropodophyllotoxin (PPT), derived from the roots of Podophyllum hexandrum, inhibited both EGFR and MET in NSCLC cells. The antitumor efficacy of PPT in gefitinib-resistant NSCLC cells (HCC827GR), was confirmed by suppression of cell proliferation and anchorage-independent colony growth. In the targeting of EGFR and MET, PPT bound with EGFR and MET, ex vivo, and blocked both kinases activity. The binding sites between PPT and EGFR or MET in the computational docking model were predicted at Gly772/Met769 and Arg1086/Tyr1230 of each ATP-binding pocket, respectively. PPT treatment of HCC827GR cells increased the number of annexin V-positive and subG1 cells. PPT also caused G2/M cell-cycle arrest together with related protein regulation. The inhibition of EGFR and MET by PPT treatment led to decreases in the phosphorylation of the downstream-proteins, AKT and ERK. In addition, PPT induced reactive oxygen species (ROS) production and GRP78, CHOP, DR5, and DR4 expression, mitochondrial dysfunction, and regulated involving signal-proteins. Taken together, PPT alleviated gefitinib-resistant NSCLC cell growth and induced apoptosis by reducing EGFR and MET activity. Therefore, our results suggest that PPT can be a promising therapeutic agent for gefitinib-resistant NSCLC.

• Proceedings of the Korean Society of Developmental Biology Conference
• /
• 2003.10a
• /
• pp.109-109
• /
• 2003

Even though success in birth of live offspring from nuclear transfer(NT) using somatic cells in many species, detailed information on processes or mechanisms of development are not well known. Cytoplasm of bovine oocyte has been known to support the development of nuclear transferred embryos using nuclear donor cells from different species. Therefore, interspecies NT might be used to find answers of some questions in basic aspect of nuclear transfer In this study, we examined the developmental potential of reconstructed embryos when bovine oocyte as a cytoplasm recipient and mouse embryonic fibroblast as a nuclear donor were used. The nuclear transfer units were aliocated in Group 1 (murine block media and normal media) and Group 2. (bovine block media and normal media). NT units were not blocked at 2-cell stage regardless of types of medium. On mouse media, poor development of interspecies NT units was observed compared to bovine media. However, as NT units cultured in bovine normal medium, embryos developed over 8-cell stage. Further studies performed to increase the developmental rate in condition of antioxidant treatment. Despite low development, bovine-murine interspecies nuclear transferred embryos could develop to blastocysts and they showed that blastocyts rate of antioxidant group was superior to those of non-antioxidant group. Next, we investigated gene expression pattern which is carried out for zygotic activation. The Xist gene is expressed in female mouse embryo after zygotic activation of 4-cell stage. But interspecies nuclear transferred embryos do not express Xist gene at 4-cell stage. As a result, it is suggested that the bovine cytoplasm controls the early preimplantation development in interspecies NT However, the development of later stages might require genomic control from transferred donor nucleus. Therefore, even though the involvement of several other factors such as mitochondrial incompatibility, effective development of embryos produced by interspecies NT requires proper genomic activation of donor nucleus after overcoming the cytoplasmic control of recipient oocytes.

• Fisheries and Aquatic Sciences
• /
• v.26 no.2
• /
• pp.158-168
• /
• 2023

The global output of Pyropia yezoensis (dried seaweed or laver, also called 'Gim' in Korea) has been reduced over the half-decade due to the wide spread of red rot disease, a serious algal disease affecting P. yezoensis. Recently, Gold 1 (G1), which is a resistant strain of P. yezoensis to red rot disease, was developed and commercialized in South Korea, yet its physiological activity has not been investigated. In this study, a comparative study was performed on G1 and commercially available strain of P. yezoensis (CP) for their antioxidative activities. Aqueous extract of G1 showed more marked 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity compared to that of CP. In 293T cells, antioxidant activity against H₂O₂-induced reactive oxygen species (ROS) formation was only observed in G1 extract. In addition, G1 extract showed more potent inhibitory effect on H₂O₂-induced apoptotic cell death than CP extract, as examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and fluorescence microscopy. Expression levels of various apoptosis-related genes, including B-cell lymphoma 2-associated X protein, p53, capase-3, and inflammatory cytokines, in H₂O₂-treated cells were significantly decreased by the treatment of G1. Taken together, the present study suggests that a new strain of red seaweed G1 can recover oxidative stress effectively by improving the imbalance of ROS generation and has a potential to be used a functional ingredient as an antioxidant source.

• Journal of the Korean Geotechnical Society
• /
• v.24 no.6
• /
• pp.37-44
• /
• 2008

At low normal stress levels, tensile strength of sand characteristically varies with either saturation or suction of soil in an up-and-down manner with a peak tensile strength that can occur at any degree of saturation. A theory that accurately predicts tensile strength of wet sand was presented in the previous study. In this study, the results of uniaxial tensile, suction-saturation and direct shear tests obtained from three sands (Esperance sand from Seattle, Washington, clean sand from Perth, Australia, and Ottawa sand) are used to validate the proposed theory. The closed form expression of the proposed theory can predict well the experimental data obtained from these sands in terms of the variation patterns of tensile strength over the entire saturation regimes, the magnitude of the tensile strength, its peak value, and the corresponding degree of saturation when the peak strength occurs.

• The Journal of Korean Medicine
• /
• v.43 no.4
• /
• pp.52-73
• /
• 2022

Objectives: The anti-inflammatory and anti-oxidative activities of LCVC (Lonicerae Flos, Citri Pericarpium and Violae Herba Complex) have not been fully elucidated. The purpose of this study was to investigate the mechanisms underlying these effects in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Methods: The evaluation of the anti-oxidative activity of LCVC was completed via DPPH and ABTS radical scavenging capacity, FRAP assay, measurement of polyphenol and flavonoid, assessment of ROS and NO levels in LPS-induced RAW 264.7 cells. The anti-inflammatory activity was defined by measuring the production of biomarkers (PGE2, IL-1B, IL-6 and TNF-𝛼), proteins (ERK, JNK, P38, Nrf2, Keap1, HO-1 and NQO1) and expressions of genes (iNOS, COX-2, IL-1𝛽, IL-6, TNF-𝛼, Nrf2, Keap1, HO-1 and NQO1) in LPS-induced RAW 264.7 cells. Results: LCVC have polyphenol and flavonoid contents. The results of DPPH and ABTS free radical scavenging capacity and FRAP assay showed that the anti-oxidative activity was increased. Production of ROS, NO, IL-6, TNF-𝛼, mRNA expressions of IL-1𝛽, IL-6, TNF-𝛼, Keap1, iNOS and COX-2 were decreased, and NQO1, Nrf2, and HO-1 were increased. In protein expression, JNK and Keap1 were decreased, NQO1, Nrf2 and HO-1 were increased, and no relationships were observed with the ERK and P38 by LCVC. Conclusions: These results suggest that LCVC may offer protective effects against LPS-induced inflammatory and oxidative responses through attenuating Nrf2/HO-1 pathway and MAPKs pathway. Therefore, we propose that LCVC has anti-inflammatory and anti-oxidative activities that have therapeutic potential in the treatment of inflammatory and oxidative disorders caused by the over-activation of macrophages.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.4
• /
• pp.533-542
• /
• 2023

Exo-polygalacturonase (exo-PG) hydrolyzes pectin acids and liberates mono-galacturonate, which plays an important role in juice extraction, and has rarely been reported. Exo-PG (AfumExoPG28A) from Aspergillus fumigatus belongs to the glycoside hydrolase 28 family. In this study, its gene was cloned and the protein was expressed and secreted in Pichia pastoris with a maximal activity of 4.44 U/ml. The optimal temperature and pH of AfumExoPG28A were 55℃ and 4.0, respectively. The enzyme exhibited activity over almost the entire acidic pH range (>20.0% activity at pH 2.5-6.5) and remained stable at pH 2.5-10.0 for 24 h. The K_m and V_max values of AfumExoPG28A were calculated by the substrate of polygalacturonic acid as 25.4 mg/ml and 23.6 U/mg, respectively. Addition of AfumExoPG28A (0.8 U/mg) increased the light transmittance and juice yield of plantain pulp by 11.7% and 9%, respectively. Combining AfumExoPG28A (0.8 U/mg) with an endo-PG (0.8 U/mg) from our laboratory, the enzymes increased the light transmittance and juice yield of plantain pulp by 45.7% and 10%, respectively. Thus, the enzyme's potential value in juice production was revealed by the remarkable acidic properties and catalytic activity in fruit pulp.