Free Radical and Enzymatic Oxygenation of Eicosanoids : Synthesis of Isoprostanes and 5-Hydroxyeicosanoid Dehydrogenase Photoaffinity Ligand

Kim, Seong Jin Florida Institute of Technology 2001 해외박사

Polyunsaturated fatty acids (PUFA) are oxidized by free radical and enzymatically. The F2-isoprostanes are unique series of prostaglandin-like compounds formed in vivo from the free radical catalyzed peroxidation of arachidonic acid (AA) 5 independent of cyclooxygenase enzyme. Recently, F3- and F4-isoprostane formations are also discovered in vivo by free-radical mechanism on phospholipids by peroxidation of eicosapentaenoic acid (EPA) 188 and docosahexaenoic acid (DHA) 189. <그림참조>(원문을 참조하세요) The synthesis of selected iPs, deuterated iPs and the development of GC/MS and LC/MS/MS methodology to identify and quantify were accomplished here. I have extended the initial focus of AA-derived iPs to metabolites of iPs, to provide a standard time for the measurement of the free radical oxidation in vivo by studying the mechanism of the metabolisms and the positive identity of metabolites of iPF2α-III and iPF2α-VI. <그림참조>(원문을 참조하세요) Moreover, I have synthesized group VI iPs derived from DHA and EPA, 356 and 370. The development of GC/MS and LC/MS/MS, as well as the syntheses of those deuterated iPs, 19,19,20,20-d4- iPF3α.VI 396 and 21,21,22,22- d4-iPF4α.VI 377 are reported here. DHA is the major polyunsaturated fatty acid (PUFA) in the brain. It is possible that the measurement of iPs derived from DHA can provide a unique index of free-radical damage in the brain and can be used for monitoring the progress of Alzheimer’s disease (AD) and the effectiveness of drug intervention. EPA is unique in that people on high fish diets (e.g. Inuits) have more EPA than AA. <그림참조>(원문을 참조하세요) Arachidonic acid is also metabolized by an enzymatic oxidation. 5- Lipoxygenase produces 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid (5-HPETE), which is converted to 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE). 5- hydroxyeicosanoid dehydrogenase (5h-dh) is a key enzyme involved in the transformation of 5-HETE to 5-oxo-ETE. 5-Oxo-ETE is the most potent eosinophil chemotactic factor among lipid mediators. We have proposed that 5-oxo-ETE may be a causative factor in diseases such as asthma involving the infiltration of eosinophils. 5-Oxo-ETE exerts its action by activating a dedicated receptor. Chemical synthesis of a radio photoaffinity labeled 5(S)-HETE analogs is necessary for the characterization, labeling, and purification of the enzyme 5h-dh. A photoaffinity radiolabelled trimethyl tin precursor was prepared by total synthesis and converted to the desired iodo derivative. <그림참조>(원문을 참조하세요)

Compositional Design and Substitution Analysis of Co-doped BaTiO3 and its Reliability

Kim, Jin Seong 부산대학교 2013 국내박사

Tm2O3와 Dy2O3가 동시첨가된 고효율 MLCC용 유전체에 대하여 분말합성 단계부터 첨가제 조성, 치환거동, 가속시험 및 고장분석에 대한 연구를 수행하였다. 수열합성법 및 고상법을 통하여 입도가 균일한 나노크기의 BaTiO3 분말을 합성하였으며 Tm2O3와 Dy2O3가 동시첨가 된 BaTiO3에 대한 조성연구를 통하여 유전율 향상과 온도안정성을 동시에 만족시키는 조건을 제시하였다. 이러한 전기적 특성의 경향은 첨가제 조성에 따른 입성장 및 core-shell 구조 형성의 관점에서 증명되었다. Dysprosium의 첨가는 유전체의 전기적 특성에 기여한 반면에 입내에서의 빠른 확산속도로 인해 결정립 성장을 일으켜 온도안정성을 저하시켰다. 반면에, thulium은 shell 부근의 분포를 통한 입계강화로써 불안정한 온도특성을 보상하여 MLCC 신뢰성 기준인 X7R을 만족시켰다. 첨가된 희토류 원소의 BaTiO3 구조내의 실질적인 분포를 증명하기 위하여, 입자가속기 분석을 통하여 A와 B site의 전자구조해석 및 흡수에너지 차이를 각각 비교함으로써 perovskite 구조내의 치환 및 분포거동을 규명하였다. Dysprosium은 양쪽성 치환거동을 통하여 B site 우선 치환 후 A site에 치환하여 BaTiO3 구조내에서 각각 acceptor와 donor로 작용하면서 유전체의 전기적 특성을 증가시켰다. 반면, thulium은 구조내의 치환거동보다는 BaTiO3 입계에 존재하여 core-shell 형성에 관여하여 절연특성 및 온도안전성에 기여한다고 확인하였다. MLCC의 신뢰성과 관련하여, 조성연구를 통해 얻어진 최적조건에 대하여 BaTiO3의 Tc인 125°C 전후 조건에서 각각 가속시험 및 고장분석을 실시하였다. 온도에 따른 고장시간 분포의 적합도 검정을 통해 형상모수 및 활성화 에너지 차이를 확인하였으며 이를 분극곡선과 tetragonality 변화를 통해 Tc 전후에서 고장메커니즘이 차이가 남을 규명하였다. 이와 같은 조성연구, 치환거동분석 및 가속시험을 차후 관련된 연구에 접목시킨다면 고효율 MLCC용 유전체의 전기적/온도 특성 및 신뢰성 향상에 기여할 수 있다고 판단된다.

Cathepsin B-Specific Prodrug Nanoparticles to Overcome Tumor Heterogeneity

Kim, Jin Seong 고려대학교 KU-KIST융합대학원 2023 국내박사

Monetary policy spillovers in risk perceptions at the zero lower bound

Kim, Seong-jin Graduate School, Yonsei University 2017 국내석사

본 논문은 국제금융위기 이후 제로금리 환경에서 미국의 통화정책 충격이 국내 주식시장과 환율시장의 수익률과 시장참여자의 위험 지각에 어떤 영향을 미치는지 구조형 VAR 모형(Structural VAR)을 통해 실증분석하였다. 고빈도 자료와 변동성지수를 사용하여 시장의 위험회피도와 불확실성에 대한 추정치를, 옵션자료와 보간법(Interpolation)을 통해 Tail risk에 대한 추정치로 리스크 리버설을 구하고, 통화정책에 대한 정보를 추출한 잠재금리의 충격이 위 3가지 위험 척도와 시장 수익률에 어떤 영향을 주는지 분석하였다. 실증분석 결과, 국제금융위기 이후 미국 연방준비위원회의 양적 완화 충격이 국내 주식시장과 환율시장 참여자의 위험 지각에 대한 추정치를 하락시킨 것을 확인하였으며, 각 시장 참여자의 위험 지각 추정치의 상승 충격이 주가수익률을 하락시키고 원화 가치를 하락시키는 결과를 확인할 수 있었다. Using risk perception estimators, risk aversion and uncertainty derived from decomposing volatility indexes with high frequency data, and a tail risk perception proxies from interpolating risk reversals, this study investigates the spillover effect of US monetary policy on the Korean stock and foreign exchange markets under a zero interest rate environment. Empirical tests under a Structural Vector Autoregressive (SVAR) framework shows that an expansionary monetary policy decreases risk perception parameters in both markets. In addition, the results confirm that an incremental shock in risk perception estimator has decreased the stock index return and depreciated the value of Korean Won in the post-Global Financial Crisis (GFC) period.

Mid Distance Communication : TheFuturistic Personal Signaling Methodby Semiotic Approach

Kim, Jin Seong International Design School For Advanced Studies H 2013 국내석사

The history of graphic design of remote signaling communication technology has developed from traditional military kite as visual communication symbol to 21st century communication device like mobile phones. My goal is to explore the new types of symbols that represent interpersonal communication system. In addition, I would explore the theory of alienation, and distance between people in a social world in connection with signaling communication symbol. During the stage of development, my aim was on generating the concept and creating a code for communication, in addition to making the voice an interactive graphic code that can be transformed and used in many formats. In my next stage of research, my goal was to integrate visual variation like digital fabrication and movies on new types of symbols that represent a new interpersonal communication system during Media Environment studio 2, Digital Fabrication class. My research was done in two contradictory directions; both directions are related to mid-distance communication. The first proceeding research is focused on ‘Communication’ which started from the area of locative media, and examines new methods of communication. The second research focuses on the concept of ‘Distancing’ through the alienated relationship between humans and machines; the output of this direction will be expressed in one movie segment. ‘Mid Distance Communication’, the name and the idea of Korean Traditional Military Kite came from my supervisor David Hall. 커뮤니케이션의 역사는 신호전달체계와 궤를 같이 하며 발달하여 왔다. 현대 우리는 시각과 오디오로 시그널할 수 있는 세대인 텔레커뮤니케이션 세대에 와 있다. 하지만 개인이 의사소통을 할 수 있는 방법은아직 획일화 되어있다. 모바일폰이나 컴퓨터를 통해서 프로그램화 된스크린을 이용해 상대방과 마주보고 이야기한다는 개념보다는 서로 보이지 않는 거리에서 텍스트를 주고 받거나 영상을 주고 받는 원거리 통신에 익숙해져 가고 있기 때문이다. (Short or Long Distance Communication) 우리는 새로운 1인미디어; 언어의 이미지화가 자유로워진 시대 에 살고 있다. 무선랜을 통해서 송출 가능한 무작위의 이미지들이 장소에 구애 받지 않고, 1초도 되지 않는 시간 안에 전송되고 있다. 이런 가능성을 가지고, 현재 쌍방향 통신의 미개척 영역인 Mid Distance Communication이 가능한 새로운 방법을 연구한다. 그와 동시에 현대 커뮤니케이션과 기술이 야기하는 인간소외를 사회학적, 기호학적 접근방법으로 연구한다. 따라서 내 연구는 두 가지의 상반된 방향으로 진행되었다. 두 가지 모두 미드 디스턴스 커뮤니케이션에 관한 연구이지만, 한 가지는 커뮤니케이션에 초점을 맞추어 진행한 연구로, 로커티브 미디어의 영역에서 출발하여 새로운 커뮤니케이션방식의 출연에 기여하는 것이고, 다른 한가지는 거리감에 초점을 맞추어 기계 혹은 미디어의 종속에 관한 고찰을 통해 소외라는 개념을 표현한 영상을 만드는 것이다.

Identification of construction project problems and their impacts on project success

Kim, Seongjin UMI Dissertation Publishing ProQuest LLC 2012 국내박사

Developing a framework of u-learning for research and practice

김성진 Graduate School of Information, Yonsei Univerisity 2010 국내박사

The purpose of this study is to develop a framework of u-Learning for research and practice, especially for promoting the benefits for all the participants and stakeholder in u-Learning services. In this study, we analyzed the status of Korean u-Learning programs currently in service as a next generation public education method, on the basis of digital textbook cases, the requirements for successful future diffusion of the u-Learning solution, and how the solution is recognized in the education field. We conducted four experiments on important aspects of the u-Learning environment from students’ and teachers’ perspectives. First, to identify user satisfaction with technological factors and learning effectiveness in the u-Learning environment, we used digital textbooks to conduct an empirical analysis of students. Second, we conducted a survey of teachers to identify the quality level of the u-Learning service as well as ZOT analysis to measure the service quality. Third, to determine the criteria for selecting the appropriate network solution for the u-Learning environment, we observed existing corresponding criteria and conducted a comparative analysis of wireless network services available in Korea, focusing on the factors required for the u-Learning environment. Finally, we detailed the four security requirements and 11 sub-elements pursuant to the characteristics of u-Learning, conducted a survey of the teachers who use digital textbooks, and obtained priorities by applying an ANP(Analytic Network Process) analysis to the survey data. According to the study’s results, the research on user satisfaction showed that general satisfaction with technical factors declined in 2009 from the level observed in 2008. However, user satisfaction with the network solution increased significantly. Observing the factors for user satisfaction with the learning effect revealed generally higher satisfaction for the digital textbook than for the normal paper textbook, which suggests that the former can possibly replace the latter in the future. The results for the overall service quality perceived by users for digital textbooks fell far behind the adequate level users had expected of the five measures, reliability received the lowest score. A comparison of the service qualities for each operating system(OS) showed generally a low score for the digital textbook service based on the Linux OS compared with the Windows-based OS. The wireless LAN(local area network) solution based on IEEE 802.11x applied to the digital textbook service in Korea was evaluated as the appropriate, at least in the current stage of the service, in terms of the speed and economic requirements for processing large-scale multimedia. However, this solution was compared unfavorably with HSDPA or mobile WiMAX. In the future, it might be desirable to establish the u-Learning environment by combining the existing wireless LAN solution with mobile WiMAX or HSDPA or future wireless network technologies such as LTE. Finally, the security priority research showed that the teachers in the field recognize confidentiality as the top priority of the four security requirements. In particular, teachers who use digital textbooks based on the Linux OS singled out “assurance of integrity of information in transmission” as the most significant requirement. Compare to other existing researches, this study suggests the u-Learning solution from the aspect of ICT(Information and Communication Technology) including user satisfaction, quality of the system, accessibility to the network, and security requirements. The results of this study will be used to establish government policies and other relevant business strategies and will provide a useful guideline for other nations and overseas business operators who wish to build a u-Learning environment for public education.

Stress distribution in peri-miniscrew area with different insertion angle of cylindrical and taper type miniscrews

김성진 Graduate School, Yonsei University 2014 국내박사

Mechanical and barrier properties of chitosan/poly lactic acid films coated by ink composition containing nanoclay

김성진 고려대학교 대학원 2011 국내석사

In this study, chitosan/PLA films were coated by ink composition containing nanoclay, which was dispersed with ultrasonic homogenizer for 20mins. Mechanical and barrier properties of chitosan/PLA films coated by nanoclay - ink composition were evaluated according to clay type and concentration. Chitosan/PLA films coated by ink composition containing Cloisite 30B showed the best mechanical and barrier properties in 6 types of nanoclays. The chitosan/PLA films coated by ink composition containing Cloisite 30B, varying in clay concentration, were investigated. Tensile strength (TS) and elongation at break (B) of these coated films had improvements in 1% Cloisite 30B. Oxygen permeability (OP) decreased significantly upon the addition of clay levels up to 1% and then slightly decreased with further increases in the amount of the clay. The value of water vapor permeability (WVP) also decreased depending on the increases of clay (0%~2.0%). Confocal laser scanning microscope (CLSM) indicated the dispersibility of Cloisite 30B in the gravure ink. When the clay content in the sample was 2.0%, the surface of coated chitosan/PLA films showed the aggregation through film emission scanning electron microscopy (FE-SEM). X-ray diffractometer (XRD) and Transmission electron microscopy (TEM) indicated that mixture of exfoliated and intercalated structure was formed with addition of 1% (w/w) Cloisite 30B to the ink after ultrasonication. Consequently, it is suggested that nanoclay - ink composition as a novel package material has great potential for partly replacing existing expensive synthetic barrier films.

Synthesis and microwave dielectric properties of Bi4(SiO4)3 ceramics

김진성 Graduate school Korea university 2009 국내석사

Bi₄(SiO₄)₃ ceramics were synthesized using conventional solid-state method and their microwave dielectric properties were investigated. The Bi_(12)SiO_(20) second phase was formed at approximately 400℃, while the Bi₂O₂SiO₃ and Bi₄(SiO₄)₃ phases started to form at 600℃. The amount of the Bi_(12)SiO_(20) and Bi₂O₂SiO₃ second phases decreased as the firing temperature exceeded 650℃. A homogeneous Bi₄(SiO₄)₃ phase was obtained for the specimen fired at 850℃. For the specimens sintered at 900℃ for long than 5 h, high density Bi₄(SiO₄)₃ ceramics could be obtained. In particular, the Bi₄(SiO₄)₃ ceramics sintered at 900℃ for 8 h exhibited the good microwave dielectric properties of εr = 14.9, Q×f = 36,101 GHz and τf = -9.42 ppm/℃. In order to study improve the sinterbility futher, B₂O₃ was added to Bi₄(SiO₄)₃ ceramics to assist the densification process at low temperatures (≤ 900℃). When the B₂O₃ content was < 3.0 mol%, a porous microstructure developed for the specimens sintered at 875℃. However, when the amount of B₂O₃ exceeded 3.0 mol%, the Bi₄(SiO₄)₃ ceramics were well sintered even at 875℃ for 0.5 h, due to the formation of a liquid phase containing B₂O₃. The microwave dielectric properties were influenced by the amount of B₂O₃, and the 3.0 mol% B₂O₃-added Bi₄(SiO₄)₃ ceramic sintered at 875℃ for 1 h showed good microwave dielectric properties of ε_(r) = 15.6, Q×f = 36,281 GHz and τ_(f) = -22 ppm/℃.