Hydrogel Coating on Surface of PLA/PBAT Blend Film via Electron Beam Irradiation

장민경,강해인,김다인,김경민,임정혁 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.2

갈파래(Ulva lactuca) 추출분획의 암 세포주에 대한 세포독성 및 면역활성 효과

장민경,김남영,이동근,이재화,하종명,하배진,김미향,배송자,장정수,이상현,Jang, Min-Kyung,Kim, Nam-Young,Lee, Dong-Geun,Lee, Jae-Hwa,Ha, Jong-Myung,Ha, Bae-Jin,Kim, Mi-Hyang,Bae, Song-Ja,Jang, Jeong-Su,Lee, Sang-Hyeon 한국생명과학회 2006 생명과학회지 Vol.16 No.7

본 연구는 갈파래(Ulva lactuca) 추출분획의 암세포주에 대한 세포독성 및 면역활성 효과를 조사하였다. 갈파래의 에탄올 추출물로부터 분획물의 제조는 hexane, ethyl ether, methanol, butanol, $H_2O$의 용매를 이용하여 행하였다. 인간 백혈암세포주(U937), 생쥐 신경아종세포주(NB41A3), 인체간암세포주(HepG2),큰지 신경교세포주(C6) 등에 대한 갈파래 분획물의 세포독성을 측정하였다. 갈파래의 Ethyl ether 층은 4종류의 세포 모두에서 가장 높은 세포독성을 나타냈다. 또한 수층 역시 비교적 높은 세포독성을 나타냈다. 4종류의 세포 모두에서 농도의존적 경향을 나타냈다. 갈파래 분획물의 큰쥐 대식세포주(RAW 264.7)에 대한 면역활성 효과도 조사하였다. 갈파래 추출물의 5가지 분획물 모두에서 농도의존적으로 NO 생산을 활성화시켰다. 이러한 결과들로 잔파래가 항암 덴 면역활성을 나타내는 천연 소재개발에 있어 유용한 후보가 될 수 있을 것으로 사료된다. Extracted fractions of the green seaweed Ulva lactuca were studied to verify the cytotoxicity and immunostimulating activity. The fractions from the ethanol extract of U. lactuca were prepared by the systematic extraction procedure with solvents such as hexane, ethyl ether, methanol, butanol and $H_2O$. The cytotoxic effects of U. lactuca fractions against human leukemia cell line U937, mouse neuroblastoma cell line (NB41A3), human hepatoma cell line (HepG2) and rat glioma cell line (C6) were investigated. Ethyl ether fraction showed the highest cytotoxicity against all four cell lines tested. In addition, $H_2O$ fraction also showed relatively high cytotoxicity. Dose dependent patterns were observed on all four cell lines. The immune-stimulating effects of U. lactuca fractions on rat macrophage cell line (RAW 264.7) were also investigated. All five fractions of U. lactuca extract stimulated NO production with concentration dependant manner. These results suggest that U. lactuca may be a useful candidate for a natural cancer preventing and immune-stimulating agents.

Template-assisted Morphological Evolution of Cu2S and Cu2MoS4 from Octahedral Cu2O Crystals

장민경,조영식,박가람,오인환,허영덕 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.11

Various morphologies of Cu2S and Cu2MoS4 were synthesized from an octahedral Cu2O template in the presence of various concentrations of sodium molybdate and thioacetamide by carrying out solvothermal reactions in an ethylene glycol solvent. The morphology varied from hollow octahedral Cu2S structures, through small pieces of P-Cu2MoS4, and finally to thin square-like plates of I-Cu2MoS4, depending on the concentrations of sodium molybdate and thioacetamide. The XRD data indicated that the Cu2MoS4 structural phases changed from P2m to I2m the concentrations of sodium molybdate and thioacetamide increased.

Fabrication of ceramide-based intercellular lipid emulsions for improving transdermal delivery

장민경,이보령,김진웅 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.1

토픽 모델링 기반의 시각적 피드백에 대한 학습자의 사용의도 분석: 온라인 토론 학습에서 성찰 활동을 중심으로

장민경,이현우 한국교육방법학회 2023 교육방법연구 Vol.35 No.1

This study aims to utilize topic modeling-based visual feedback and examine its effect in order to increase the ease and effectiveness of feedback in online discussion learning. Therefore, learners' perceptions of whether topic modeling-based visual feedback on discussion contents is helpful for their reflection during reflection activities on discussions were investigated, and structural relationships between variables that affect intention to use were explored. To this end, we conducted discussion activities for 31 learners in a major lecture at A university in Seoul, and conducted text analysis and visualization through LDA topic modeling for discussion articles written by learners. After that, we presented learners with topic modeling-based visual feedback on the content of the discussion and then had them reflect on the discussion, and conducted a usability survey on the presented feedback to find out learners' perceptions. In addition, hierarchical multiple regression analysis was conducted according to the technology acceptance model(TAM) to investigate the effect of perceived usefulness and perceived ease on acceptance intention and the mediating effect of attitude. As a result of the study, learners recognized that topic modeling-based visual feedback was easy to grasp the opinions of other learners, intuitively understand the discussion results, and reflect on their writings through feedback. On the other hand, it is pointed out that feedback interpretation is difficult, so it is necessary to provide feedback use education and explanation. In addition, it was found that perceived usefulness and perceived ease had a positive effect on learners' intention to accept topic modeling-based visual feedback, and that attitude mediated them. Through this study, learners who easily understand and usefully recognize visual feedback based on topic modeling form a positive attitude toward feedback as a facilitating factor for reflection in the acceptance process and increase the intention to use it. This highlights the need for visual feedback on the content of the discussion. In addition, improvements to enhance the effectiveness of visual feedback have been proposed. 본 연구는 온라인 토론학습에서 피드백의 용이성과 효과성을 높이기 위해 토픽 모델링 기반의 시각적 피드백을 활용하고 그 효과를 살펴보고자 하였다. 이에 토론에 대한 성찰 활동 시 토론 내용에 대한 토픽 모델링 기반의 시각적 피드백이 학습자의 성찰에 도움이 되는지에 대한 학습자들의 인식을 알아보고, 사용의도에 영향을 미치는 변인 간의 구조적 관계를 탐색하였다. 이를 위하여 서울 소재 A대학의 전공 강의에서 31명의 학습자를 대상으로 토론 활동을 진행하고, 학습자들이 작성한 토론글에 대해 LDA 토픽 모델링을 통한 텍스트 분석 및 시각화를 실시했다. 이후 학습자들에게 토론 내용에 대한 토픽 모델링 기반 시각적 피드백을 제시한 후 토론에 대해 성찰하도록 하였고, 제시된 피드백에 대한 사용성 설문을 진행하여 학습자들의 인식을 알아보았다. 또한 기술수용모형에 따라 위계적 중다회귀분석을 실시하여 피드백에 대한 인지된 유용성과 인지된 용이성이 수용의도에 미치는 영향과 태도의 매개효과를 알아보았다. 연구 결과, 학습자는 토픽 모델링 기반 시각적 피드백이 다른 학습자들의 의견을 파악하기에 용이하고, 토론 결과를 직관적으로 확인할 수 있으며 피드백을 통해 자신의 글을 성찰할 수 있다고 인식하였다. 또한 학습자들이 토픽 모델링 기반 시각적 피드백을 수용하려는 의도에 인지된 유용성과 인지된 용이성이 긍정적인 영향을 미치고, 태도가 매개하는 것으로 나타났다. 본 연구를 통해 토픽 모델링 기반의 시각적 피드백을 쉽게 이해하고 유용하게 인식하는 학습자일수록 수용과정에서 성찰의 촉진 요소로서 피드백에 대한 긍정적인 태도가 형성되고 사용의도가 높아진다는 점에서 토론의 내용에 대한 시각적 피드백의 필요성이 강조되었다. 반면에 피드백 해석의 용이성이 낮다는 점이 지적되어 피드백 사용 교육 및 해설 제공 등 시각적 피드백의 효과성을 향상시키기 위한 개선점이 제안되었다.

VIVA 청춘!_여비 곰신, 이제 꽃신 신어요

장민경 샘터사 2014 월간 샘터 Vol.529 No.-

전북 완주 신풍유적 출토 초기철기시대 동검의 부식 및 제작특성

장민경,조남철 대한금속·재료학회 2020 대한금속·재료학회지 Vol.58 No.7

The subject of this study was a bronze sword excavated from the early Iron Age area of Sinpung site in Wanju. SEM-EDS, FE-EPMA and Raman Micro-Spectroscopy analysis methods were applied to investigate the manufacturing techniques and corrosion characteristics. The results of the analysis indicated a casting structure composed of both α and α+δ phases. The α phase developed in the form of dendrite, and it seems that no heat treatment was performed. Through the EDS analysis results, the main components of the bronze sword were identified as Cu, Sn, Pb, etc., and it seems that the cooling rate was different depending on the shape of the dendrite, which is the α phase, and the size and distribution of the Pb particles. Regarding corrosion characteristics, the corrosion progressed considerably to the surface, and a high tin corrosion layer was formed, and lead oxide and copper oxide particles were observed between the corroded microstructures. These materials were identified by Raman spectroscopic analysis as Cuprite (Cu2O), Malachite (Cu2CO3(OH)2), Cassiterite (SnO2), Cerussite (PbCO3), Anglesite (PbSO4), and Litharge (PbO). Among them, the presence of nanocrystalline SnO2 confirmed the characteristics of long-term corrosion of bronze artifacts in the burial environment. And, materials such as Cerussite (PbCO3), Anglesite (PbSO4), and Litharge (PbO) were found only in weapons and tools such as bronze sword and spear when compared with previous studies.

온라인게임과 모바일게임 내 확률형 아이템의 소비

장민경 이화여자대학교 스크랜튼대학 스크랜튼학부 2019 ATE Vol.9 No.-

The Efficacy of Language Learning Strategy Instruction in a Korean High School English Class

장민경 한국중등영어교육학회 2019 중등영어교육 Vol.12 No.3

This paper examines the efficacy of language learning strategy instruction based on the cognitive academic language learning approach (CALLA). This paper studies the effect of language learning strategy instruction with particular reference to English proficiency, learning strategies, and the relationship between such strategies and motivation of a Korean high school student. In this study, seventy-nine high school students were given twenty weeks of instruction. The control groups were given lectures without employing a language learning strategy programs; conversely, the experimental groups utilized language learning strategies. In order to assess student language proficiency, pre- and post-tests were given. SILL and questionnaires related to motivation as well as language learning strategy use were also adopted. Results showed that the scores of less-proficient students in the experimental group dramatically improved. The most frequently used strategy was cognitive strategy, while metacognitive strategy was reported least applied. After CALLA instruction, the experimental group of students used metacognitive strategy more actively. In addition, there was a strong correlation between language proficiency and language learning strategy use. This study also indicates that learner motivation influenced language learning strategies. Therefore, the implementation of language learning strategy instruction based on the cognitive academic language learning approach (CALLA) should be considered in language classes in Korean high schools.

기능성 청국장 제품 개발을 위한 신균주 검색 및 효능 검증

장민경,김남영,유병홍,김기영,김성구,이상현 한국생명과학회 2006 한국생명과학회 심포지움 Vol.46 No.-