• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.370-374
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• 2013

The effects of zinc chloride addition on pore development of porous carbon nanofibers prepared by polyacrylonitrile (PAN)/ N,N'-dimethylformamide (DMF) (10 wt%) electrospinning were investigated. The change of morphological and structural modification by zinc chloride activation was investigated by a scanning electron microscopy (SEM) analysis. $N_2$ adsorption isotherm characteristics at 77 K were confirmed by Brunauer-Emmett-Teller (BET) and Horvath-Kawazoe (H-K) equations, and the curves showed the Type I mode in the International Union of Pore and Applied Chemistry (IUPAC) classification, indicating that lots of micropores exist in the sample. In addition, specific surface areas and total pore volumes of porous carbons prepared by the zinc chloride activation were determined as 600~980 $m^2/g$ and 0.24~0.40 $cm^3/g$, respectively. As experimental results, many holes or demolished structures were found on the fiber surfaces after the zinc chloride activation as confirmed by a SEM analysis. It was also observed that various pore sizes were found to be depended on the adding content of zinc chloride in PAN/DMF solution in this system.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3723-3727
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• 2015

The p53 tumor suppressor protein is a principal mediator of growth arrest, senescence, and apoptosis in response to a broad array of cellular damage. p53 is a substrate for the ubiquitin-proteasome system, however, the ubiquitin-conjugating enzymes (E2s) involved in p53 ubiquitination have not been well studied. UBE2Q1 is a novel E2 ubiquitin conjugating enzyme gene. Here, we investigated the effect of UBE2Q1 overexpression on the level of p53 in the MDA-MB-468 breast cancer cell line as well as the interaction between UBE2Q1 and p53. By using a lipofection method, the p53 mutated breast cancer cell line, MDA-MB-468, was transfected with the vector pCMV6-AN-GFP, containing UBE2Q1 ORF. Western blot analysis was employed to verify the overexpression of UBE2Q1 in MDA-MB-468 cells and to evaluate the expression level of p53 before and after cell transfection. Immunoprecipitation and GST pull-down protocols were used to investigate the binding of UBE2Q1 to p53. We established MDA-MB-468 cells that transiently expressed a GFP fusion proteins containing UBE2Q1 (GFP-UBE2Q1). Western blot analysis revealed that levels of p53 were markedly lower in UBE2Q1 transfected MDA-MB-468 cells as compared with control MDA-MB-468 cells. Both in vivo and in vitro data showed that UBE2Q1 co-precipitated with p53 protein. Our data for the first time showed that overexpression of UBE2Q1can lead to the repression of p53 in MDA-MB-468 cells. This repression of p53 may be due to its UBE2Q1 mediated ubiquitination and subsequent proteasome degradation, a process that may involve direct interaction of UBE2Q1with p53.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.3
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• pp.219-229
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• 2020

Recently, since atopic dermatitis is sensitive to skin irritation, it has been suggested that the development of a patch that can effectively exhibit adhesion and absorption to a specific local area while minimizing skin irritation, and capable of appropriate drug release should be given priority. In this study, we tried to develop a hydrogel patch that minimizes skin irritation, adheres effectively to a specific area, and promotes absorption. The atopic patch was formulated into a super-absorbent hydrogel sheet using a freeze drying method. Cell viability assay was carried out using keratinocytes (HaCaT cell) and fibroblasts (L929 cells). In order to investigate the physical properties, FT-IR, FE-SEM, porosity analysis and swelling behavior were investigated. As a result, the newly prepared HA-Dex hydrogel patch was verified by biocompatibility and physical evaluation. In addition, the manufactured hydrogel patch has sufficient moisture absorption capacity and can relieve itching of atopic skin, and is expected to be applied to various drug delivery products for the treatment of atopic dermatitis in the future.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.20-20
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.97-97
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• 2017

Plant genomes include heterochromatic loci that consist of repetitive sequences and transposable elements. LTR retrotransposon is the major class of transposons in advanced plants in terms of proportion in plant genome. The elements contribute not only to genome size but also to genome stability and gene expression. A number of cases have been reported transposon insertions near genic regions affect crop traits such as fruit pigments, stress tolerance, and yields. Functional LTR retrotransposons produce extrachromosomal DNA from genomic RNA by reverse transcription that takes place within virus-like-particles (VLPs). DECREASED DNA METHYLATION 1 (DDM1) plays important roles in maintaining DNA methylation of heterochromatin affecting all sequence contexts, CG, CHG, and CHH. Previous studies showed that ddm1 mutant exhibits massive transcription of retrotransposons in Arabidopsis, but only few of them were able to create new insertions into the genome. RNA-dependent RNA POLYMERASE 6 (RDR6) is known to function in restricting accumulation of transposon RNA by processing the transcripts into 21-22 nt epigenetically activated small interfering RNA (easiRNA). We purified VLPs and sequence cDNA to identify functional LTR retrotransposons in Arabidopsis ddm1 and ddm1rdr6 plants. Over 20 LTR copia and gypsy families were detected in ddm1 and ddm1rdr6 sequencing libraries and most of them were not reported for mobility. In ddm1rdr6, short fragments of ATHILA gypsy elements were detected. It suggests easiRNAs might regulate reverse transcription steps. The highest enriched element among transposon loci was previously characterized EVADE element. It has been reported that active EVADE element is more efficiently silenced through female germline than male germline. By genetic analyses, we found ddm1 and rdr6 mutation affect maternal silencing of active EVADE elements. DDM1-GFP protein accumulated in megaspore mother cell but was not found in mature egg cell. The fusion protein was also found in early embryo and maternal DDM1-GFP allele was more dominantly expressed in the embryo. We observed localization of DDM1-GFP in Arabidopsis and DDM1-YFP in maize and found the proteins accumulated in dividing zone of root tips. Currently we are looking at cell cycle dependency of DDM1 expression using maize system. Among 10 AGO proteins in Arabidopsis, AGO9 is specifically expressed in egg cell and shoot meristematic cells. In addition, mutation of AGO9 and RDR6 caused failure in maternal silencing, implying 21-22 nt easiRNA pathway is important for retrotransposon silencing in female gametophyte or/and early embryo. On the other hand, canonical 24 nt sRNA-directed DNA methylation (RdDM) pathways did not contribute to maternal silencing as confirmed by this study. Heat-activated LTR retrotransposon, ONSEN, was not silenced by DDM1 but the silencing mechanisms require RdDM pathways in somatic cells. We will propose distinct mechanisms of LTR retrotransposons in germline and somatic stages.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.111-120
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• 2020

Remarkable scientific and technological achievements are mainly shown in the 'super-convergence' or 'convergence of convergence' among cross- disciplinary fields, and advanced countries are promoting the 'high-risk, high-return research' ecosystem. Google LLC is carrying out numerous new challenges in terms of a non-failure perspective. Innovative research by the US Defense Advanced Research Projects Agency (DARPA) has produced such breakthroughs as the Internet, GPS, semiconductors, the computer mouse, autonomous vehicles, and drones. China is pioneering a 'Moon Village' and planning the world's largest nuclear fusion energy and ultra-large particle accelerator project. Japan has also launched 'the moonshot technology development research system' to promote disruptive innovation. In Korea, the government is preparing a new research program to tackle the global scientific challenges. Therefore, it is necessary to determine the reasonable geoscientific challenges to be addressed and to conduct a preliminary study on these topics. For this purpose, it is necessary to conduct long-term creative research projects centered on young researchers, select outstanding principal investigators, extract innovative topics without prior research or reference, simplify research proposal procedures, innovate the selection solely based on key ideas, and evaluate results by collective intelligence in the form of conferences.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.487-495
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• 2007

The objectives of the present study were to initiate cloning of Korean native goat by somatic cell nuclear transfer (NT) and to examine whether unovulated (follicular) oocytes can support the same developmental ability of NT embryos as ovulated (oviductal) oocytes after hCG injection in stimulated cycles of the goat. The in vivo-matured and immature oocytes were collected from the oviducts and follicles of superovulated does, respectively, and the immature oocytes were maturated in vitro. Ear skin fibroblasts derived from a 3-yr-old female Korean native goat were used as the donors of nuclei or karyoplasts. Following fusion, activation and in vitro culture to a 2- to 4-cell stage, 49 in vitro-derived and 105 in vivo-derived embryos were transferred to 6 and 17 recipient does, respectively. One doe and three does of the respective groups were identified as pregnant by ultrasonography on day 30 after embryo transfer. However, only one doe, which had received in vivo-derived embryos, delivered a normal female kid of 1.9 kg on d 149. The cloned kid gained more weight than her age-matched females as much as 87% during the first 4 mo after birth (17.7 vs. $9.4{\pm}0.8$ kg) and reached puberty at 6-mo age a few months earlier than normal female does. The telomere length of the kid, which was similar to that of the donor fibroblast at 2-mo age, decreased 8% between 2- and 7-mo ages. Moreover, at 7-mo age, she had 21% shorter telomere than her age-matched goats. To our knowledge, this is the first case in which a cloned animal born with a normal weight exhibited accelerated growth and development. The unusually rapid growth and development of the cloned goat may have resulted from SCNT-associated epigenetic reprogramming involving telomere shortening.

• BMB Reports
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• v.37 no.6
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• pp.720-725
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• 2004

A number of signaling molecules contain small pleckstrin homology (PH) domains capable of binding phosphoinositides or proteins. Phospholipase C (PLC)-${\gamma}1$ has two putative PH domains, an $NH_2$-terminal (PH1) and a split PH domain ($nPH_2$ and $cPH_2$). We previously reported that the split PH domain of PLC-${\gamma}1$ binds to phosphatidylinositol 4-phosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate (PI(4,5)$P_2$) (Chang et al., 2002). To identify the amino acid residues responsible for binding with PI(4)P and PI(4,5)$P_2$, we used site-directed mutagenesis to replace each amino acid in the variable loop-1 (VL-1) region of the PLC-${\gamma}1$ $nPH_2$ domain with alanine (a neutral amino acid). The phosphoinositide-binding affinity of these mutant molecules was analyzed by Dot-blot assay followed by ECL detection. We found that two PLC-${\gamma}1$ nPH2 domain mutants, P500A and H503A, showed reduced affinities for phosphoinositide binding. Furthermore, these mutant PLC-${\gamma}1$ molecules showed reduced PI(4,5)$P_2$ hydrolysis. Using green fluorescent protein (GFP) fusion protein system, we showed that both $PH_1$ and $nPH_2$ domains are responsible for membrane-targeted translocation of PLC-${\gamma}1$ upon serum stimulation. Together, our data reveal that the amino acid residues $Pro^{500}$ and $His^{503}$ are critical for binding of PLC-${\gamma}1$ to one of its substrates, PI(4,5)$P_2$ in the membrane.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.209-212
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• 2013

The Nuri process of emphasis by the Ministry of Education to promote is standardized curriculum at the national level for the education and care. It is to improve the quality of pre-school education and Ensure a fair starting line early in life and It emphasizes character education in all areas of the window. Nuri the process of development of a the insect robot for the Creativity education Increased the interesting and educational effects. Assembly and the effect on learning of educational content using a VR educational robot using the existing floor assembly using the online website to help assemble and learning raised. Order to take advantage of information technology in the information-based society requires the active interest and motivation in learning, creative learning toddlers learning robot are also needed. A three-dimensional model of the robot, and augmented by linking through the marker, the target marker and the camera relative to the coordinate system of augmented reality, seeking to convert the marker to be used in augmented reality marker patterns within a pre-defined patternto be able to make a decision on what of. The fusion of a smart education through training and reinforcement the educational assembly of the robot in the real world window that is represented by a virtual environment in this paper to present a new form of state-of-the-art smart training, you will want to lay the foundation of the nation through the early national talent nurturing talent.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.10-17
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• 2016

This paper presents a laboratory validation of a new approach for Finite Element Model Updating(FEMU) on short-span bridges by combining ambient vibration measurements with static load input-deflection output measurements. The conventional FEMU approach based on modal parameters requires the assumption on the system mass matrix for the eigen-value analysis. The proposed approach doesn't require the assumption and even provides a way to update the mass matrix. The proposed approach consists of two steps: 1) updating the stiffness matrix using the static input-deflection output measurements, and 2) updating the mass matrix using a few lower natural frequencies. For a validation of the proposed approach, Young's modulus of the laboratory model was updated by the proposed approach and compared with the value obtained from strain-stress tests in a Universal Testing Machine. Result of the conventional FEMU was also compared with the result of the proposed approach. It was found that proposed approach successfully estimated the Young's modulus and the mass density reasonably while the conventional FEMU showed a large error when used with higher-modes. In addition, the FE modeling error was discussed.