University-Industry Linkages for Technology Transfer, Commercialization and Sustainable Industrialization in Zimbabwe : Lessons learnt from South Korea

Witness T. Ukama Handong Global University, Graduate School of Glob 2016 국내석사

Most universities in both developed and developing countries have become more entrepreneurial due to economic hardships and capital shortages. Hence the current focus of using research on commercialization is to generate revenues. A significant proportion of unemployed population in Zimbabwe are graduates from universities and other higher tertiary institutions. Zimbabwe is characterized by the highest unemployment rate (about 90%) in Southern Africa despite being the country with the highest literacy ranking in Africa. The capacity utilization by manufacturing companies in Zimbabwe has dwindled down to 39% from 57% in 2011 (Confederation of Zimbabwe Industries, 2013). This indicates a big challenge for the country in terms of employment creation, poverty reduction and socio-economic development. There is increased pressure on universities to act as a bridge for transfer of knowledge to industries and generate resources. This paper is based on the case studies of Harare Institute of Technology (Zimbabwe) and Yonsei University and POSTECH University (South Korea) in order to propose the best model for technology transfer, examine the success factors and constraints in establishing sustainable university-industry linkages as well as suggesting strategies for sustainable industrialization. Qualitative research methods is used and most information is gathered using secondary sources such as journals, websites, government policies and also semi-structured interviews for few respondents from Harare Institute of Technology and its partner companies. The key success factors identified included the following: good communication and cooperation from the partners, collaborative investment on research and development, human resource development, political and economic stability and the supportive regulation environment whilst constraints identified are lack of advanced laboratories; inadequate financial support, conflict of interests and lack of detailed policies on intellectual property. -The paper propose the adoption of the Non-Linear Multi-Helix model as the feasible solution for effective technology transfer and commercialization.

(A) comparative study on global start-up propensity : focus on the case of young adults of Korea, Vietnam and Nepal

이신일 Handong Global University 2017 국내석사

The international community’s ODA paradigm in the 21st century has reached the point where it is necessary to develop a new ODA paradigm. According to the UN and OECD reports, the importance of the role of Start-up is emphasized at the heart of national economic development and young adult job creation. In addition, the agenda for Start-up as sustainable development is being discussed constantly. They are interested in young adult Start-up as a catalyst role in economic growth between countries in the rapidly changing globalization. The purpose of this paper is as follows. First, the Start-up propensities of the young adults of the three countries of Korea, Vietnam, and Nepal would be compared. Second, global trends in Young adult Start-up would be compared. Third, the characteristics of the necessity and possibility of global activities of the three countries would be analyzed. Finally, based on the results of the research, policy suggestions for creating common values through experience and understanding of various cultures would be presented. In order to verify the purpose of this study, research was based on research reports and previous literature of international organizations and institutions. It was attempted to investigate the correlation between the Start-up propensity and Global awareness of Korean, Vietnamese, and Nepalese young adults and the related variables. For quantitative analysis, correlation analysis and MANOVA using SPSS 21.0 were performed. The results of this study are as follows. First, the difference between the Start-up propensities of the young adults of the three countries showed that Nepalese young adults showed higher tendency towards Start-up whereas Vietnam was somewhat lower. Second, although there are differences in Start-up propensities among the three countries, there is no difference in Global activities and possibilities in common. According to descriptive statistics analysis, young adults from three countries have a somewhat positive mindset about global activities and possibilities. Finally, the need for Global Start-up activities differed among young adults from three countries. In particular, the poorest Nepalese young adults were found to have a high need for Global Start-up activities. Therefore, it will be important for governments and other international organizations to vitalize policies to support 'Global Young adult Start-ups’ from a variety of external sources

The Adoption of E-Commerce for the SMEs development in Myanmar, 2015 : Lessons learned from South Korea and Thailand

Win Pa Pa Thu Handong Global University, Graduate School of Glob 2016 국내석사

Small & Medium Enterprises(SMEs) are the backbone of the country economy almost every country across the globe but especially in developing countries. Myanmar is one of the least developing countries in South East Asia and mainly based on agriculture sector. SMEs play the vital role in contribution to national economy in Myanmar. The role of ICT is very crucial in current globalization era. ICTs are very useful not only to access information globally but also as an important mechanism in people daily life. E-Commerce becomes popular and success method across the globe to achieve businesses effectively of SMEs with low establishment cost. Inadequate access to financing, limited market access, skilled labor & skilled experts, poor market access are the most common difficult problems that faced by Myanmar SMEs according to my survey result. There is no doubt that e-Commerce is more effective than traditional commerce not only to access market globally but also to reduce operation cost. In this connection, the implication of e-Commerce for Myanmar SMEs creates the competitive advantages business society with new trend. This paper aims to present to implement e-Commerce system for SMEs growth and competitive advantages in Myanmar. For this purpose, its study describes the importance role of SMEs in Myanmar and their difficulties for development. It highlight the vital role of adoption ICT as main driver for the development of SMEs and suggests adopting e-Commerce system for the development SMEs with government supports. It also proposes to modify the necessary legal framework for e-Commerce. It also analyzes the cases of two countries and their critical success factors of e-Commerce implementation in South Korean, one of the Asian Tigers and Thailand, one of Myanmar’s neighbor countries. The outcome of this study is to observe the success experiences of the implementation of e-Commerce for SMEs in two countries and to propose and adopt the good practices of e-Commerce implication to elevate the SMEs sector including the entrepreneurs and start-up businesses’ development in Myanmar.

Antifungal and Emulsifying Activities of Bacillus sp. LP03 and its agricultural use : Biosurfactant를 생산하는 Bacillus sp. LP03의 항진균성 및 계면활성의 확인 및 그에 따른 농업적 이용에 대한 고찰

장혜원 Handong Global University 2005 국내박사

Biosurfactant를 생산하는 것으로 알려진 균주 Bacillus sp. LP03이 가진 대표적인 활성인 antifungal activity가 포항부추의 pathogen인 잿빛곰팡이 병에 저해활성을 가진 것으로 실험실 수준에서 확인 하였으며 이에 따라 포장실험을 통하여 곰팡이병뿐 아니라 식물의 성장에도 positive한 영향을 미치는 것을 확인하였다. 또 다른 활성으로 유화활성에 대한 실험또한 진행하였으며 서로 다른 oil로 오염된 토양에서 식물체의 성장이 균을 처리한 토양에서 월등한 성장을 보임에 따라 토양에서의 균의 생육이 시간이 지남에 따라 활발한 것을 확인 하였으며 hydrocarbon estimation을 한 결과 75%의 hydrocarbon이 분해가 되었으며,자연적으로 소실된 양은 25%로 확인되었다. This report investigates antifungal activity and effects of growth promotion by biosurfactant produced from Bacillus sp. LP03 against fungus causing plants disease (Glay Mold-Botrytis cinerea). Antifugal activity against B. cinerea infeeted to Allium tuberosum Rottler exhibited better than antifungal agent (smilex). Especially, one of the strains, named Bacillus sp. LP03 showed strong antifungal activity on field studies. Then we found that the effective of Bacillus sp. LP03 producing biosurfactants let the plants (Green gram) survive and even promote the growth of shoot and root length in oil-spoiled soil. The seeds were treated with 0, 1, 2% of oil-contaminated soil and the length of soot and root were different each other. In the case of the seeds in the soil containing 2% oil without the bacteria, they couldn't grow and not even survive. The other seeds in the soil containing 1% oil were shown with different growth, some seeds with the bacteria grew well rather than without the bacteria. According to the results of upper experiments, we assumed that the bacteria have a hydrocarbon degradation ability. The bacterial growth was increased until 8th day and reduced sharply to 13th day. In following results, 75% of hydrocarbon in gasoline with the bacteria was degraded and 25% of all hydrocarbons were removed naturally.

Development of an Electrical Computer Tomography Method using Capacitance for Analysis of Two-phase Flow in the Rectangular Pipe : 사각관에서의 이상유동 해석을 위한 캐패시턴스를 이용한 전기적 컴퓨터 토모그라피 방법의 개발

이경황 Handong Global University 2002 국내박사

이상유동의 해석을 위한 전기적 캐패시턴스 토모그라피 시스템이 개발되었다. 순방향 전사에서는 전극판 사이에 축적되는 캐패시턴스의 유전율 분포와의 비선형성이 선형화 되었다. 전기장은 포이손 방정식의 유한차분화를 통해 계산되었으며, 캐패시턴스의 선형화는 민감도 행렬, S를 통해 이루어졌다. 본 연구에서는 역전사를 위해 LBP, TR, ITR, PLI의 등의 알고리즘이 채택 되었으며, 더 나아가 ITR 방법에서의 항등 행렬을 S^(T)S의 대각 행렬로 대체하여 MITR 알고리즘을 새롭게 개발하였다. 직관에서의 이상 유동 해석을 위해, 제시된 방법을 코드화 하였다. 제안된 다양한 알고리즘의 성능 및 유효성을 평가하기 위해 유전율의 변화 효과와 노이즈의 간섭효과 등의 두 가지 경우가 선택되었다. 유전율 변화 효과에 대해서는 PLI와 새롭게 개발된 방법이 좋은 성능을 가졌다. 노이즈의 저항성에 대한 평가를 위해 오프셋 노이즈와 랜덤 노이즈가 이용되었다. 채택된 알고리즘들 중 MITR 방법이 가장 좋은 성능을 보여줬다. 이상의 연구를 통해 사각관에서의 이상유동해석을 위해 본 연구에서 개발된 전기적 캐패시턴스 토모그라피 코드가 사용 가능함을 알 수 있었다. An Electric Capacitance Tomography system for the analysis of two-phase flow was developed. The forward projection was linearized from the nonlinear relation between the fields of the capacitance accumulated onto the electrode pairs. The electric field was calculated by the finite difference formulation of the Poisson Equation. The linear relation between the capacitance and the distribution of the dielectric constant of medium produced the sensitivity matrix S as the linear forward projection. For the backward projection procedures, in the present study, we furnished almost all the algorithms known LBP, TR, ITR and PLI. Furthermore, we developed a new method by changing the identity matrix of the Tikhonov method with the diagonalized S^(T)S. The developed methods were actualized in a computer code for the analysis of the two-phase flow in the rectangular pipe. In order to evaluate the validity and performance of the various suggested algorithms, two cases were selected: the effect of the variation of the dielectric constant and the effect of noise interference. For the variation of the dielectric constant according to the pressure and temperature, the PLI method and the present new method showed a good performance. For the noise resistance, the offset noises were introduced to the reference capacitance values. Among the algorithms the new method developed in this work had the strong noise immunity. Through the study, it was found that the developed code for the electrical capacitance tomography can be used for the analysis of two-phase flow in the rectangular pipe.

(A) study on zoom homogenizer for laser shock peening

김태신 Handong Global University 2018 국내박사

In the field of Laser Shock Peening (LSP) as well as various laser materials processing, a uniform beam is favorable for processing quality, and a square-shaped beam is advantageous for process efficiency, respectively. A beam homogenizer makes it possible to generate a square-shaped uniform beam simultaneously. The beam homogenizer is an optical system that has already been applied to the other materials processing, but there is no beam homogenizer for the LSP yet. Until now, it has been difficult to fabricate a lens array which is the fundamental optics of a beam homogenizer for the LSP. For the design, it is essential to manage the risks of the coating damage and the plasma formation inside the optical system due to the high energy input beam. Despite the absence of the previous studies on the beam homogenizer for the LSP, this study has dealt with the overall actual design issues. Also, we proposed an optical system that can change the area of a square-shaped beam irradiated by adding a zoom function to a conventional beam homogenizer in real time. In this study, we designed a zoom homogenizer suitable for laser shock peening. In Chapter I, we look at the theoretical background and motivation of this study. We review the concept and research trend of laser shock peening. And we propose a beam homogenizer which can generate a square-shaped uniform beam. In Chapter II, we deal with the working distance of the beam homogenizer which should be considered when applying square-shaped beam homogenizer to laser shock peening process. For this, we configured the beam homogenizer in two kinds of simulation: illumination and diffraction methods. We performed the illumination simulation based on geometrical ray optics with CODE V, a commercial lens design program. And we used Fresnel diffraction theory and convolution theory for the diffraction simulation. In both simulations, we obtained multiple beam data around the image plane of the beam homogenizer. Since the plasma threshold of the metal target is an essential variable due to the characteristics of the laser shock peening process, we considered the plasma threshold in the simulations. We defined the range where the energy efficiency over the plasma threshold is above 0.5 as the depth of focus(DOF) of the beam homogenizer for the LSP (LSP-DOF). Also, we defined the range where the root mean square(RMS) of the beam distribution over the plasma threshold is less than 5% as the depth of uniformity(DOU) of the beam homogenizer for the LSP(LSP-DOU). And we defined the range where these two ranges overlap is defined as the working distance(WD) of the beam homogenizer for the LSP (LSP-WD). Finally, we show the effect of some parameters on the LSP-DOF, LSP-DOU, and LSP-WD. In Chapter III, we introduce the concept, features, and limitations of the conventional beam homogenizer, and deal with the newly proposed zoom homogenizer design method. The zoom homogenizer was assumed to be a thin lens and was designed using the equivalent focal length of the lens system. The conventional beam homogenizer has an imaging condition when there are two lens arrays. The generated illumination field is uniform, and the edge is clear in imaging condition. However, under this condition, zooming is impossible. When changing the distance between the lenses to zoom, the imaging condition is broken, and a clear beam is not formed. In this chapter, the imaging condition is derived to produce sharp illumination fields at all zoom positions. We verified the validity of the zoom homogenizer with CODE V, a commercial lens design program. The size of the illumination field was changed at each zoom position, but the sharpness remained the same. In Chapter IV, we have dealt with the design of a zoom homogenizer suitable for an LSP to apply the zoom homogenizer to the LSP. Though we designed the zoom homogenizer with a thin lens approximation, in this chapter, we considered the thickness of lenses to place the lenses precisely. We derived the imaging condition of the zoom homogenizer considering the thickness. In consideration of the high energy density of the input beam to be injected into the homogenizer, we confirmed the illumination simulation whether the coating of the lens is tolerable. We also performed a risk analysis for plasma formation that may occur at the focus of the main beam and the ghost beam. We also analyzed the LSP-WD characteristics defined in Chapter II for the designed zoom homogenizer. A monitoring system has been designed for real-time monitoring the square-shaped beam or the plasma at the metal target. The zoom homogenizer system for the LSP proposed in this study contains a waterjet type nozzle, and the nozzle allows water to be laminar flow inside of itself. Finally, we provide the final drawings of the design of the zoom homogenizer system for the LSP designed so far. 레이저 충격 피닝(LSP)을 포함한 다양한 레이저 재료 가공 분야에서 균일한 빔은 가공 품질에 유리하며 사각형 빔은 공정 효율에 유리하다. 빔 균질기는 사각형의 균일 한 빔을 동시에 발생시킬 수 있게 한다. 빔 균질기는 이미 다른 재료 가공에 적용된 광학 시스템이지만 LSP 용 빔 균질기가 아직 없다. 지금까지는 LSP 용 빔 균질기의 렌즈 어레이를 제작하는 것에 어려움이 있었다. 또한 설계를 위해서는 고 에너지 입력 빔으로 인한 광학 시스템 내부의 코팅 손상 및 플라즈마 형성의 위험을 분석하는 것이 필수적이다. LSP에 대한 빔 균질기에 대한 이전 연구가 없었음에도 불구하고 본 연구는 전반적으로 실제적인 설계 문제를 다루었다. 또한 기존의 빔 균질기에 줌 기능을 추가하여 조사된 사각형 빔의 면적을 실시간으로 변화시킬 수 있는 광학 시스템을 제안하였다. 본 연구에서는 LSP에 적합한 줌 균질기를 설계하였다. Chapter I에서는 본 연구의 이론적인 배경 및 동기를 제공하며, 기존 레이저 충격 피닝의 개념 및 연구 동향을 소개한다. 또한 균일한 사각 빔 생성에 적합한 빔 균질기에 대한 개념을 소개한다. Chapter II에서는 사각 빔 균질기를 레이저 충격 피닝 공정에 적용할 때 고려해야 할, 빔 균질기의 작업거리에 대한 연구를 다루었다. 이를 위해 조명 및 회절 두 종류 방식으로 빔 균질기를 구성하고 시뮬레이션을 수행하였다. 조명 시뮬레이션은 상용 렌즈설계 프로그램인 CODE V로 구성하였고, 회절 시뮬레이션은 프레넬 회절 이론과 컨볼루션 이론을 기반으로 구성하였다. 두 시뮬레이션 모두, 빔 균질기의 이미지 평면 주변에서 다수의 빔 데이터를 얻었다. 레이저 충격 피닝 공정 특성상 금속 타겟의 플라즈마 한계치가 중요한 변수이므로 이를 고려하여 시뮬레이션을 수행하였다. 인풋 에너지 대비 플라즈마 한계치 이상에서의 에너지 효율이 0.5 이상일 때를 LSP를 위한 빔 균질기의 초점 심도(LSP-DOF)로 정의하였다. 플라즈마 한계치 이상에서의 빔 분포의 RMS가 5 % 이하일 때의 범위를 LSP를 위한 빔 균질기의 균일도 범위(LSP-DOU)로 정의하였다. 이 두 범위가 겹치는 영역을 LSP를 위한 빔 균질기의 작업거리(LSP-WD)로 정의하였다. 끝으로, 빔 균질기 및 금속 타겟의 파라미터 변화가 LSP-DOF, LSP-DOU 및 LSP-WD에 미치는 영향을 보여준다. Chapter III에서는 기존 빔 균질기의 개념, 특징 및 한계를 소개하고, 본 연구에서 새로 제안하는 줌 균질기 설계법을 다룬다. 줌 균질기는 얇은 렌즈로 가정하였고, 렌즈 시스템의 등가 초점 거리를 사용하여 설계하였다. 기존 빔 균질기는 렌즈 어레이가 2개일 때 이미징 조건이 존재하며, 이 때 생성되는 조명 필드는 균일하며 가장자리가 선명하다. 그러나 이 조건으로는 줌이 불가능하여, 줌을 시도하기 위해 렌즈간 거리를 변경할 경우 이미징 조건을 만족하지 않아 가장자리가 선명한 조명 분포가 형성되지 않는다. 본 챕터에서는 모든 줌 위치에서 선명한 조명 필드를 생성하도록 이미징 조건을 유도하였다. 줌 위치별로 조명 필드의 사이즈는 변하지만 선명도가 그대로 유지되는 결과를 상용 렌즈 설계 프로그램인 CODE V를 통해 확인하였다. Chapter IV 에서는, 실제로 줌 균질기를 LSP에 적용하기 위해서 LSP에 적합한 줌 균질기 설계에 대한 내용을 다루었다. 앞서 얇은 줌 균질기를 얇은 렌즈로 가정하여 설계하였으나, 실제 렌즈는 두께를 가지고 있으므로 두께를 고려하여 이미징 조건을 유도하고 설계하였다. 실제 줌 균질기로 입사될 인풋 빔의 높은 에너지 밀도를 고려해, 렌즈의 코팅이 견딜 수 있는지 조명 시뮬레이션을 통해 확인하였다. 메인 빔 및 고스트 빔의 초점 형성에 의한 플라즈마 형성에 대한 위험 분석을 수행하였다. 또한 설계한 줌 균질기에 대해, Chapter II에서 정의한 LSP-WD 특성을 분석하였다. 줌 균질기 광학계 설계뿐 아니라, 타겟에서 생성되는 사각 빔이나 플라즈마를 실시간 관측하기 위한 모니터링 시스템을 설계하였다. 본 연구에서 제안하는 레이저 충격 피닝용 줌 균질기는 물 분사형 방식이므로, 노즐 내부 물의 유동이 층류가 되도록 노즐을 설계하였다. 끝으로 본 연구에서는 지금까지 설계한 줌 균질기의 최종 도면을 제공한다.

Antigenotoxic Activity of Lactic Acid Bacteria from Korean Fermented Kimchi and Identification of Selected Strains : 김치에서 분리한 유산균들의 항유전독성 활성과 이들의 동정에 대한 연구

김윤주 Handong Global University 2004 국내박사

식이와 관련하여 암이 높은 발생률을 보인다는 관점에서, 하나의 중요한 연구 목표로 유전독성을 가지는 발암원들과 그것들의 활성을 방해하는 잠재력을 지닌 영양적 요인들의 동정을 말할 수 있다. 본 연구에서는 김치로부터 우세 발효 유산균주를 분리하고 직접발암물질인 N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)를 이용하여 이들이 갖는 항유전독성 활성을 조사하였다. 단일 세포 겔 전기영동 기술(코멧법) 은 여러 포유동물 세포들에 있어 DNA 손상을 측정하는 방법이다. 코멧법은 단일 세포들에 존재하는 DNA 절편을 감지하는데에 민감하고 빠른 기술이다. 그래서 이 기술을 이용하여 6종류의 김치들로부터 분리한 30종의 우세 발효 유산균주들의 항유전독성 활성을 측정함으로 이것들이 가지는 암예방 잠재력을 조사하였다. 먼저 3T3 세포주를 이용하여 각종 김치로부터 분리한 30종의 우세 발효 유산균주들의 항유전독성 활성을 검색한 뒤, 효과가 뛰어난 8종을 선발하여 Spraque-Dawley rat의 대장 세포에서 이들의 항유전독성 활성을 조사하였다. 또한 이들을 동정한 결과 이들은 Leuconostoc mesente sub. mesenteroides, Lactobacillus plantarum, Lactobacillus brevis 등으로 확인되었다. 김치로부터 분리한 총 30종의 유산균주 중 약 25~30% 정도인 8종의 유산균주들(부추김치에서 분리한 B-1, B-5, B-6, 오이김치에서 분리한 O-4, O-5, 백김치에서 분리한 M-2, 열무김치에서 분리한 Y-5 그리고 포기김치에서 분리한 P-1)은 MNNG에 대하여 유의할만한 항유전독성 활성을 나타내었고, 특히 B-1과 B-6는 Spraque-Dawley rat의 primary colon cells에서도 매우 강한 항유전독성 활성을 보였다. 결론을 말하자면, 이 연구는 김치로부터 분리한 우세 발효 유산균주들 중 일부가 3T3 세포와 Spraque-Dawley rat의 대장 세포 모두에 있어 MNNG에 의한 유전독성을 강하게 저해하며 그 기작은 알 수 없지만, 특히 부추김치로부터 분리한 B-1(Lactobacillus plantarum)과 B-6(Lactobacillus brevis)는 강한 암예방 잠재력을 가진다고 말할 수 있다. In view of the high incidence of dietary-related tumors, one important research goal is to identify the participating genotoxic carcinogens and the nutritional factors that may counteract their activities. In this study, dominant lactic acid bacteria strains were isolated and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a directly acting carcinogen, was treated to investigate the antigenotoxic activity of these isolates. Single cell gel electrophoresis technique (in other words, comet assay) is a relatively simple, rapid and sensitive method for measuring DNA strand breaks at the level of single cells, and is widely used to measure DNA damage in various mammalian cells. Therefore, I used comet assay to examine the antigentoxic activity of 30 different isolates of dominant lactic acid bacteria strains which were extracted from 6 other kinds of Kimchi, and furthermore investigated the potential of cancer prevention of these isolates. First, the antigenotoxic activity of 30 different isolates of dominant lactic acid bacteria strains were screened using 3T3 cell line. Next, among these isolates, 8 isolates which showed strong antigenotoxic activity were selected and their antigenotoxic activities were examined in primary colon cells of Spraque-Dawley rat. Further identification of these isolates classified them into strains of Leuconostoc mesente sub. mesenteroides, Lactobacillus plantarum and Lactobacillus brevis. Among 30 strains isolated from several kimchi, about 25 to 30 percent of them, 8 strains (B-1, B-5, B-6 isolates from buchu kimchi, O-4, O-5 from cucumber kimchi, M-2 from baik kimchi, Y-5 from yeolmoo kimchi and P-1 from baechu kimchi) showed antigenotoxic activity. Especially B-1 and B-6 isolates revealed significantly strong antigenotoxic activity in primary colon cells of Spraque-Dawley rats. In conclusion, several isolates of dominant lactic acid bacteria strains which were isolated from Kimchi strongly inhibited the genotoxic effect induced by MNNG treatment in both 3T3 cell line and primary colon cells from Spraque-Dawley rat. Although the mechanisms have yet to be revealed, it is sufficient to conclude through this study that these isolates, especially B-1(Lactobacillus plantarum) and B-6(Lactobacillus brevis) isolated from buchu kimchi have strong potential of cancer prevention.

Gene Expression and Characterization of the Recombinant Korean Mistletoe (Viscum Album Coloratum) Lectin : 한국산 겨우살이 렉틴 유전자의 발현 및 특성에 관한 연구

김의호 Handong Global University 2006 국내석사

한국산 겨우살이 렉틴은 이황화 결합(di-sulfide bond)으로 결합된 A와 B사슬(chain)로 이루어져 있다. 선행 연구를 통해 한국산 겨우살이 렉틴이 cytokine 분비 증가, NK세포 활성화와 같은 면역반응의 증장으로 인해 항암 효과를 증가시킨다는 것이 밝혀졌다. 게다가 한국산 겨우살이 렉틴은 인플루엔자 바이러스 항원과 함께 경비 (intra-nasal)로 쥐에 투여했을 때 강한 점막 면역 증강 효과를 보였다. 이에 관련한 기작을 연구하기 위해 우리는 한국산 겨우살이 렉틴 유전자의 cDNA를 클론했다. 그리고 렉틴의 A와 B 각각의 유전자를 대장균 시스템을 이용해서 수용성 단백질 형태로 독립적으로 발현하고 Ni-NTA 컬럼을 통해 정제하고 그 생물학적인 활성을 분석하였다. 재조합 한국산 겨우살이 렉틴 A1 단백질은 겨우살이에세 추출된 렉틴 (KML-C), 유럽산 겨우살이 렉틴과 유사한 리보좀-불활성화 효과 (Ribosome Inactivating Activity)를 보였다. 하지만 암세포 살상 효과에서는 이 두 대조군에 비해 훨씬 감소된 효과를 보였는데, 이는 세포 표면에 부착해서 내부로 들어갈 수 있도록 도와주는 역할을 하는 것으로 알려진 B chain의 결여 때문일 것으로 생각된다. 또한 재조합 A1 단백질은 쥐 대식세포주인 Raw264.7을 자극해서 TNF-α와 같은 cytokine을 분비를 자극했다. 재조합 B1 단백질의 발현과 정제도 역시 완료되었는데, B1 단백질은 재조합 단백질로 발현하는데 매우 독특한 특성을 가진 것으로 보인다. 그래서 그 생산성이 재조합 A1 단백질에 비해 현저히 떨어졌고, 순수한 B1 단백질 분리를 위해서 더 강한 정제 조건이 적용되어야 했다. B1 단백질의 특성에 관한 연구는 진행 증이다. 이 연구는 한국산 겨우살이 렉틴이 점막 면역 증강제로 개발되는 데, 또한 그 면역 증강 기작을 규명하는 데 필용한 지식과 기반을 제공할 것이다. Korean mistletoe pectin (KML) is composed of an A chain and a B chain bridged with a di-sulfide bond. Previous studies demonstrated that the KML increased an anti-cancer activity via augmented immune responses, such as cytosine induction and NKr cell activation. In addition, the KML showed a strong m.cosap adjutant effect in mice when treated along with influenza virus antigens. To study the underlying mechanism, we cloned the DNA of the Korean mistletoe pectin (KML) gene. The KML genes of A and B were independently expressed as soluble recombinant proteins using an Esclrericlzia cola system, purified via a Ni-NTA column and then characterized their b opogicap activities. The recombinant KML-A1 chain (rKML-A1) showed a strong ribosome inactivating activity in an an voter analysis, which is similar to that of the wild type KML and European mistletoe pectin. The rKML-A1, however, showed a significantly reduced cancer cell kipping activity. This may be due to pack of help of the B chain for the target cell entry of the A chain. The rKML-A1 also induced cytosine production, such as TNF-α, from a macrophage cell pine (RAW264.7). Expression and purification of the rKML-B1 chain was also completed. The property of rKML-B1 may be unusual to express and purify as a recombinant protein. In contrast to rKML-A1, therefore, protein yield of soluble rKML-B1 was very low and also rKML-B1 was purified in the harsh conditions to get pure eluted protein. Characterization of the bioactivities of the rKML-B1 is currently underway. This study will give us fundamental materials and knowledge for further study of mucosap adjutant development and adjutant mechanism.

Study on the Effect of Retinoic Acid on Adipogenesis and Insulin Sensitivity in vitro

Hong Seong-Eui Handong Global University 2001 국내박사

Identification and cholesterol lowering effect of Lactic Acid Bacteria from Kimchi : 김치에서 분리한 유산균의 분리 동정과 콜레스테롤 저하 효과에 대한 연구

조규성 Handong Global University 2006 국내박사

고농도의 cholesterol은 심혈관계 질환을 일으키는 중요한 요인 중의 하나이다. 특히 사람의 혈중 높은 cholesterol 수치는 사람을 죽음에까지 이르게 하는 심장 마비와 같은 심혈관계 질환의 주요 원인으로 밝혀 졌다. 이로 최근에 콜레스테롤을 저하하는 유용한 기능이 있는 유산균에 대한 관심이 증가 하고 있다. 특히 유산균은 한국의 발효 김치의 우종균으로 알려져 있다. 이 실험을 통해 5 종류의 김치로부터 유산균을 분리 하였고 각각의 형태학적인 특징과, 물리적인 특징에 따라서 분리하였다. 이를 더욱 정확하게 동정하기 위하여 repetitive element sequence-based polymerase chain reaction (rep-PCR), randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR), and 16S rDNA gene sequencing의 유전형 동정 방법을 사용하였다. In vitro 실험으로 8종류의 LAB가 broth 상에서 cholesterol 저하 기능이 있는 것으로 나타났으며, HFI 58, HFI 40, Yeoulmu E 이 세 종류의 strains이 유의성 있는 cholesterol 저하 효과를 보였다. 위의 세 균을 선택하여 우진 B&G 회사를 통해 사료와 한 후 닭을 대상으로 in vivo test를 실시한 결과 HFI 58을 처리한 집단에서 유의성 있는 달걀의 cholesterol 수치 저하가 관측되었다. High levels of cholesterol are considered to be a major risk factor for vascular disease including coronary heart disease. Lipid research clinic program in USA reported that the higher total serum cholesterol is in humans, the greater is the risk for the emergence of coronary heart disease which cause human death. Much attention is recently being given to further elucidate beneficial functions of lactic acid bacteria for human health as probiotic function like reduction of cholesterol. Lactic acid bacteria are dominant microflora in fermented kimchi. In this study, lactic acid bacteria were isolated from 5 kinds of fermented kimchi and determined their physiologic property. Total 31 of LAB were isolated from kimch samples. In order to identify the LAB more accurately, were done repetitive element sequence-based polymerase chain reaction (rep-PCR), randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR), and 16S rDNA gene sequencing. 8 of them were selected by their ability to lower cholesterol level in vitro test. HFI 58, HFI 40, and Yeulmu E4 strains showed significant cholesterol lowering effect in vitro test. These were made of special feed of chicken by WooJin B&G. A Diet was tested during 5 weeks and feed of supplement with HFI58 strain groups had significant lower cholesterol concentration in egg yolk.