각종 변이원에 대한 쇠비름 추출물의 돌연변이 억제 효과

최근표,정성원,김은정,함승시 동아시아식생활학회 1997 동아시아식생활학회지 Vol.7 No.4

This study was performed to determine the effects of antimutagenicity of Porturaca oleracea L. in Korea. In Ames test, the ethanol extract of Poturaca oleracea L. inhibited mutagenic activity of N-methyl N'-nitro N-nitrosoguanidine(MNNG), 4-nitroquinoline-l-oxide (4NQO), benzo(α)pyrene(B(α) P) and 3 amino-1.4-dimethyl-5H-pyrido-(4,3-b)indole (Trp-P-1) in Salmonella typhimurium TA98 and TA100. But hot-water extract Porturaca oleracea L. only inhibited mutagenic activity of MNNG in Saltmonella typhimurium TA100. On 4NQO, the ethanol extract 100~1,600㎍ /plate of Porturaca oleracea L. showed a slight inhibitory effect of 13~48%, 4~47% in TA98 and TA100, respectively, but on MNNG, it showed higher inhibitory effect of 6~86% in TA100. And the treatment of 1,600㎍/plate of ethanol extract of Porturaca oleracea L. had strong antimutagenicity with 74-87% inhibition against TA98 and TA100 induced by B(a)P and with 85~93% inhibition against TA98 and TA100 induced by Trp-P-1. The ethanol extract was fractionated with ether, chloroform, ethylacetate, butanol and water. Among them, most of the fraction except water fraction showed strong antimutagenicity effects against mutation induced by 4-NQO, MNNG, B(a)P and Trp-P-1. Chloroform fraction had strong antimutagenicity with 91% inhibition against TA100 induced by MNNG, diethyl etherfraction had strong antimutagenicity with 92%, 98% inhibition against TA98 and TAI00 induced by 4NQO, Chloroform fraction had strong antimutagenicity with 97% inhibition against TA100 induced by B(a)P and diethyl etherfraction had strong antimutagenicity with 98% inhibition against both strain induced by Trp-P-1, respectively.

A Study on the Effect of Education APPs on the Learning Participation and Learning Effect of University Students

Shi Kun Liu,김영길,Jia Zhao 한국무역연구원 2022 무역연구 Vol.18 No.3

Purpose The education APPs offers new ways of learning and improves the quality of learning for students, who actively use this new learning platform to access more and better teaching resources. However, the current research on learning participation and learning effect of education APPs is mainly focused on establishing a single hypothesis, and there is a lack of systematic interpretation. Therefore, it is imperative to study how education APPs should increase the participation and effectiveness of students. Design/Methodology/Approach This paper takes students who have used trade education APPs as the research object, and uses the method of combining theoretical research and data analysis to conduct in-depth research on the degree of student participation and learning effect, and puts forward corresponding countermeasures and suggestions according to the research results. Findings According to the research questions, on the basis of literature research, it is concluded that education APPs has four characteristics, such as perceived usefulness, perceived ease of use, perceived interactivity, and course content quality. Secondly, according to the empirical analysis results, it is found that perceived usefulness, perceived ease of use, perceived interactivity, and quality of course content have a positive impact on learning engagement, and learning engagement has a positive impact on learning outcomes. Research Implications In terms of theory, this study makes up for the deficiencies of existing theoretical research by investigating the use of education APPs by students and what characteristics of education APPs can improve the learning effect of students. In terms of practice, it provides reference suggestions for providers of education APPs to improve APPs functions and improve business performance in the future.

A study of the components of children’s digital educational game achievement system

Kun Shi(사곤),DongMin Cho(조동민) 한국디자인학회 2021 한국디자인학회 학술발표대회 논문집 Vol.2021 No.5

The compounding effect of children"s serious game achievement system on learning motivation

Shi, Kun(사곤),Cho, Dong Min(조동민) 한국전시산업융합연구원 2021 한국과학예술융합학회 Vol.39 No.3

At present, the value and role of children"s digital game achievement system for game education have not attracted public’s attention. Due to lack of related experience and theories, the design and research of game achievement system lack theoretical basis and reference experience. In this paper, we study the influence of the achievement system of the children"s educational games on learning motivation, and the mediating effect between game user experience satisfaction (GUES) and enjoyment. We used structural equation model to find out the relationship and role. The purpose of this paper: To empirically examine the influence of children"s DEG achievement system on learning motivation and the double mediating effect of game user experience satisfaction (GUES) and enjoyment. Find out the main factors of the achievement system that affect GUES, enjoyment, and learning motivation. Provides a valuable reference and necessary support for the research and design of children"s DEG achievement system. The findings and contents of the study are as follows, first of all, The results show that the achievement system has a significant impact on learning motivation through the mediating effect of GUES and enjoyment. GUES and enjoyment are important predictors. Secondly, the five components of the achievement system are all related to the use of GUES and enjoyment. The reward is an important factor affecting GUES, with social interaction is an important factor affecting enjoyment. Enhancing Social and Reward can help improve the influence of the achievement system on learning motivation. Finally, there are recommendations for establishing an effective DEG achievement system for children.

The compounding effect of children"s digital educational game achievement system on Learning engagement

Shi, Kun(사곤),Cho, Dong Min(조동민) 한국전시산업융합연구원 2021 한국과학예술융합학회 Vol.39 No.5

At present, the value of the achievement system children’s digital educational game (DEG) achievement system has not attracted extensive attention. The lag of theoretical research makes the research and design of the DEG achievement system lack of theoretical basis and reference experience. The purpose of this study is to explore the impact of DEG achievement system on learning engagement under the mediating effect of academic emotions. In this process,509 children took part in this research. A structural equation model was used to verify the role and relationship. The results show that: First, the DEG achievement system has a significant impact on learning engagement through the mediating effect of academic emotion. The achievement system is an important factor affecting learning engagement in deg. Second, Under the mediating effect of different valence and arousal academic emotions, the impact of the achievement system on learning engagement is significantly different, which makes learning engagement change. Third, the achievement system has a greater impact on positive-high arousal emotion and negative-low arousal emotion. Strengthening the two emotions through an achievement system will enhance learning engagement. The conclusion of this study has theoretical and practical guiding significance for the research and design of the DEG achievement system.

A parameterized model of fixed joint interface based on virtual material

Kun Shi,Guangpeng Zhang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.11

To improve the application simplicity of the research outcomes of fixed joint interface characteristics from mechanical structural numerical analysis, we proposed a parameterized model of a fixed joint interface based on virtual material. Based on the GreenwoodWilliamson contact model, Hertz-Mindilin contact theory, characteristic study of fixed joint interface in the unit area, and considering the impacts of various factors of contacting surfaces, we obtained the virtual material parameters of a fixed joint interface: Elastic modulus, Poisson’s ratio, thickness, and density. Focusing on a mechanical structure with bolt connections, we carried out a numerical analysis of the structural deformation under various loading applications, and compared the analysis results with experimental measurements to validate the feasibility and accuracy of the virtual material parameters of the fixed joint interface. This research lays a foundation for further study of the whole character of mechanical structures.

Research on the Components of Children’s Educational Game Achievement System

Kun Shi,Dong Min Cho 한국멀티미디어학회 2021 멀티미디어학회논문지 Vol.24 No.9

RV-23, a Melittin-Related Peptide with Cell-Selective Antibacterial Activity and High Hemocompatibility

( Shi Kun Zhang ),( Qian Ma ),( Su Bo Li ),( Hong Wei Gao ),( Ying Xia Tan ),( Feng Gong ),( Shou Ping Ji ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

RV-23 is a melittin-related antibacterial peptide (MRP) with lower cytotoxicity than either melittin or AR-23, another MRP. The aim of this study was to explore the mechanism of RV- 23`s antibacterial selectivity and its hemocompatibility. The results showed that all the peptides exhibited lytic activity against Staphylococcus aureus and Escherichia coli, with RV-23 showing the highest potency. Moreover, RV-23 had lower cytotoxicity than melittin or AR-23 at their minimal inhibitory concentration. In addition, CD experiments showed that melittin, RV-23, and AR-23 all had a typical α-helical structure, and RV-23 had the lowest α-helix content. The structural information showed that RV-23 has the lowest hydrophobicity and highest hydrophobic moment. Because hydrophobicity and α-helix content are believed to correlate with hemolysis, the results indicate that the selective lytic activity against bacteria of RV-23 may be due to its low hydrophobicity and α-helicity, which lead to low cytotoxicity without affecting antibacterial activity. Furthermore, RV-23 did not affect the structure and function of blood components such as red blood cells, platelets, albumin, and the blood coagulation system. In conclusion, RV-23 is a cell-selective antibacterial peptide with high hemocompatibility due to its unique structure.

Process of Equiaxed Grains of RE-Al Alloy under Slope Vibration

Xie Shi-kun,Yi Rong-xi,Pan Xiao-liang,Zheng Xiao-qiu,Guo Xiu-yan 한국소성가공학회 2010 기타자료 Vol.2010 No.6

A new technique using slope vibration casting process during heating and isothermal holding period to prepare Al-7Si-2RE alloy has been studied. The small, near-spherical and non-dendritic microstructure with the semi-solid processing requirements has been obtained. Experiments show that the cooling method, pouring process and the convection of melt caused by slope vibration had significant effects on the formation of near-spherical primary gains. The water-cooled copper mold casting with slope vibration at the temperature near liquidus can obtain Al-7Si-2RE alloy with small homogeneous equiaxed grains, the average grain diameter is 48.3μm, and the average grain roundness is 1.92.

모바일 게임 인터랙티브 인터페이스 사용자경험에 관한 연구 - 노인 사용자를 중심으로

시쿤 ( Shi Kun ),조동민 ( Cho Dong Min ) 한국기초조형학회 2019 한국기초조형학회 학술발표논문집 Vol.2019 No.2