지랄레논 생합성 효소의 세포 구획화 연구

학위논문(석사) -- 서울대학교대학원 : 농업생명과학대학 농생명공학부, 2021.8. 손호경.Fusarium graminearum 은 전세계적으로 밀, 보리, 옥수수, 벼 등 주요 작물에 Fusarium head blight (FHB)를 일으키는 중요한 식물병원균이다. 이 곰팡이는 심각한 수확량 감소를 일으킬 뿐만 아니라 감염된 작물에 zearalenone (ZEA)과 trichothecene (DON and NIV) 등의 곰팡이독소를 축적시켜 인간과 동물의 건강에 심각한 위협을 끼친다. ZEA의 구조는 에스트로겐과 유사하며 포유류의 에스트로겐 수용체와 결합하여 에스트로겐의 작용을 방해하여 생식기능 장애를 일으킨다. 이전 연구에서는 ZEA 생합성 유전자 (PKS4, PKS13, ZEB1, ZEB2)와 그들의 F. graminearum에서 ZEA 생합성의 작용 메커니즘에 대해 연구하였다. 그러나 ZEA 생합성 효소의 세포내 위치와 ZEA 생산에 필요한 세포 조직에 대해서는 거의 알려져 있지 않다. 본 연구에서는 녹색형광단백질(GFP)을 Pks4, Pks13, Zeb1에 표지하였고, 모든 단백질이 ZEA 유도 조건에서 특정 세포소기관에 위치하는 것을 관찰하였다. Zeb1-적색 형광 단백질 (RFP) 결합 단백질을 Pks4-GFP와 Pks13-GFP 균주를 기반으로 하여 발현시켰다. 그 결과 Pks4, Pks13, Zeb1은 특정 세포소기관에서 위치하는 것을 보이고 있었다. 특정 세포소기관을 밝히기 위해 FM4-64 염색과, peroxisome 표적 신호인 SKL에 RFP를 표지하여 관찰하였다. 그 결과 모든 ZEA 생합성 효소가 퍼옥시좀(peroxisome)에 위치하는 것을 확인하였으며, 이는 zearalenone이 peroxisome에서 생합성됨을 시사한다. 본 연구는 polyketide 계열의 이차대사산물이 합성되는 위치에 대한 정보를 제공하며, 새로운 곰팡이 독소 저해 전략을 개발할 수 있을 것이라고 생각한다.Fusarium graminearum is a plant pathogen that causes Fusarium head blight (FHB) in major cereal crops such as wheat, barley, corn, and rice worldwide. Not only does this fungus causes destructive yield losses, it also accumulates mycotoxins, zearalenone (ZEA) and trichothecene (DON and NIV), on infected grains, which pose serious threat to human and animal health. The structure of ZEA is similar to estrogen, and it binds to estrogen receptors of mammals and interferes with effect of estrogen, resulting in reproductive dysfunction. Previous studies characterized ZEA biosynthetic genes (PKS4, PKS13, ZEB1, and ZEB2) and their mechanism of action in ZEA biosynthesis of F. graminearum. However, we still know relatively little about subcellular localization of the ZEA biosynthetic enzymes and the cellular machinery required for ZEA production. In this study, green fluorescent protein (GFP) was tagged to Pks4, Pks13, and Zeb1, and all proteins were revealed to localize in specific organelles under ZEA inducing condition. Moreover, Zeb1-Red fluorescent protein (RFP) fusion protein was expressed in Pks4-GFP and Pks13-GFP background strains. The results showed that Pks4, Pks13, and Zeb1 were co-localized in specific cellular organelles. FM4-64 staining and expression of RFP tagged with SKL, which is peroxisome targeting signal (PTS), were performed to reveal the specific organelles. I found that all of ZEA biosynthetic enzymes are exclusively localized in peroxisomes, suggesting that zearalenone is expected to be biosynthesized in peroxisome. This study will provide information on where the polyketide secondary metabolites are biosynthesized, and let us develop a novel mycotoxin reduction strategy.ABSTRACT 5 INTRODUCTION 10 MATERIALS AND METHODS 13 I. Fungal strains and culture conditions 13 II. DNA extraction, Southern blotting and PCR 13 III.. Subcellular localization 18 IV. Toxin analysis 19 V..Microscopic observations 19 RESULTS 20 I. Localization of ZEA biosynthetic mutants 20 II. Celluluar compartmentalization of ZEA biosynthetic enzymes 26 DISCUSSION 29 LITTERATURE CITED 32 APPENDIX 36 LIST OF TABLES . Table 1. F. graminearum strains used in this study 14 Table 2. Primers used in this study 15 LIST OF FIGURES . Fig 1. Localization of ZEA biosynthetic enzymes in Zeb2OE strains 21 Fig 2. Localization of ZEA biosynthetic enzymes in Zeb2OE strains in organelles 23 Fig 3. Localization of ZEA biosynthetic enzymes 24 Fig 4. Co-localization of ZEA biosynthetic enzymes. 25 Fig 5. FM4-64 staining at GFP tagged mutants. 27 Fig 6. Cellular comparmentalization of ZEA biosynthetic enzymes. 28석

Neuroprotective effects of FK-011 and growth hormone as caspase inhibitors against hypoxic-ischemic brain injury in neonatal rats : 1H magnetic resonance spectroscopic study

학위논문(박사)--서울대학교 대학원 :의학과 재활의학 전공,2003.Docto

Kospi 200지수 옵션시장의 Local 변동성 추정과 헤징 연구

학위논문(석사)--아주대학교 일반대학원 :경영학과,2008. 2블랙-숄즈 옵션모델은 옵션시장에서 가장 많이 사용되는 모델이다. 하지만 이 모델은 변동성이 일정하다는 가정으로 출발했기 때문에 현실에서 발생하는 변동성 미소나, 변동성 기간구조를 설명하지 못한다. 본 논문에서는 Derman, Kani and Chriss 모델을 이용하여 Kospi 200지수의 위험중립 확률 및 지역 변동성을 찾았다. 지역 변동성은 미래 특정 시점 그리고 주가에 따라 기대되는 변동성을 말한다. 또한 지역 변동성이 변할 경우 발생되는 옵션의 가치 변화를 헷징할 수 있는 방법에 대해 연구했다. 끝으로 지역 변동성의 변화 요인을 찾아보기 위해 행사가격을 바탕으로 주성분 분석(PCA)을 했다.제1장 서론 = 1 1.1 연구의 배경 및 목적 = 1 1.2 논문의 구성 = 2 제2장 변동성 = 3 2.1 역사적 변동성 = 3 2.2 블랙-숄즈와 내재 변동성 = 3 2.3 내재변동성의 수치적 접근법 = 4 2.3.1 뉴튼-랩슨법 = 4 2.3.2 이분법 = 5 2.4 내재변동성의 특징 = 5 제3장 내재삼항트리 = 7 3.1 내재삼항트리 구조 = 8 3.2 State-space = 8 3.3 위험중립확률과 지역 변동성 = 9 3.3.1 선도 가격과 전이 확률 = 10 3.3.2 옵션 가격과 전이 확률 = 10 제4장 지역 변동성의 헷징 = 12 4.1 무이표 채권 이자율 헷징 = 12 4.2 유로피안 옵션 변동성 헷징 = 14 4.2.1 헷징 포트폴리오의 활용 = 18 제5장 주성분 분석 = 18 제6장 결론 = 19 6.1 데이터 설명 = 19 6.2 결과 분석 및 한계점 = 19MasterBlack-Scholes option pricing is the most popular model in the option market. However it does not explain a volatility smile or a volatility term structure because of a Black-Scholes assumption that volatility is constant. In this paper, I figured out the risk neutral probability and local volatility in KOSPI 200 Index option market using the Derman, Kani and Chriss model. -Local volatility is the market’s estimate of index volatility at particular future time and market level. Also I studied the hedging method for change of the option value caused by the change of local volatility. Finally I will study the Principal Component Analysis to find factors in change of the local volatility

뇌졸중 환자에서의 경직 정도의 객관적 판정

학위논문(석사)--서울대학교 대학원 :의학과 재활의학전공,1996.Maste

The effect of robot-assisted gait training on cortical activation in stroke patients: A functional near-infrared spectroscopy study

OBJECTIVE: To investigate the effects of the robot-assisted gait training on cortical activation and functional outcomes in stroke patients. METHODS: The patients were randomly assigned: training with Morning Walk (R) (Morning Walk group; n =30); conventional physiotherapy (control group; n= 30). Rehabilitation was performed five times a week for 3 weeks. The primary outcome was the cortical activation in the Morning Walk group. The secondary outcomes included gait speed, 10-Meter Walk Test (10MWT), FAC, Motricity Index-Lower (MI-Lower), Modified Barthel Index (MBI), Rivermead Mobility Index (RMI), and Berg Balance Scale (BBS). RESULTS: Thirty-six subjects were analyzed, 18 in the Morning Walk group and 18 in the control group. The cortical activation was lower in affected hemisphere than unaffected hemisphere at the beginning of robot rehabilitation. After training, the affected hemisphere achieved a higher increase in cortical activation than the unaffected hemisphere. Consequently, the cortical activation in affected hemisphere was significantly higher than that in unaffected hemisphere (P = 0.036). FAC, MBI, BBS, and RMI scores significantly improved in both groups. The Morning Walk group had significantly greater improvements than the control group in 10MWT (P = 0.017), gait speed (P = 0.043), BBS (P = 0.010), and MI-Lower (P = 0.047) scores. CONCLUSION: Robot-assisted gait training not only improved functional outcomes but also increased cortical activation in stroke patients

용융상 또는 고체상 PET 속에서 에틸렌 글리콜의 확산

학위논문(석사) - 한국과학기술원 : 화학공학과, 1991.2, [ xii, 79 p. ]Diffusivity of EG in melt and solid state PET was obtained by using the quartz spring sorption apparatus. The quartz spring has a maximum extension of 500mm and its corresponding maximum weight of 1 gram. The change of spring length was measured by Cathetometer with the accuracy of $10^{-4}$cm. The temperature of sorption apparatus was controlled by the silicon oil jacket. Diffusivity of EG was determined by fitting iteratively the experimental data of sorption and desorption with the modeling developed to consider both diffusion and reactions simultaneously. The diffusion coefficient of EG(Deg) in solid state PET is found to be proportional to the volume fraction of amorphous region of PET sample, and Deg is $2.75\times 10^8cm^2/sec$ at 230℃, $X_c$ = 0.373. The activation energy for diffusion in solid state PET is 51.8 kcal/gmol, which is slightly higher than that of melt state. In PET melt, diffusion coefficient of EG in the limit of zero-concentration is found to be $4.47\times 10^{-7}cm^2/sec$, and the activation energy for diffusion is 39.5 kcal/gmol. It is found that the diffusivity of EG for desorption is slightly larger than one for absorption, which results from the concentration effect of diffusivity. The heat of solution for sorption in PET melt is 54.7 kcal/gmol.한국과학기술원 : 화학공학과

The effect of pelvic movements of a gait training system for stroke patients: a single blind, randomized, parallel study

Background: Aging societies lead to higher demand for gait rehabilitation as age-related neurological disorders such as stroke and spinal cord injury increase. Since conventional methods for gait rehabilitation are physically and economically burdensome, robotic gait training systems have been studied and commercialized, many of which provided movements confined in the sagittal plane. For better outcomes of gait rehabilitation with more natural gait patterns, however, it is desirable to provide pelvic movements in the transverse plane. In this study, a robotic gait training system capable of pelvic motions in the transverse plane was used to evaluate the effect of the pelvic motions on stroke patients. Method: Healbot T, which is a robotic gait training system and capable of providing pelvic movements in the transverse plane as well as flexion/extension of the hip and knee joints and adduction/abduction of the hip joints, is introduced and used to evaluate the effect of the pelvic movement on gait training of stroke patients. Gait trainings in Healbot T with and without pelvic movements are carried out with stroke patients having hemiparesis. Experiment: Twenty-four stroke patients with hemiparesis were randomly assigned into two groups and 23 of them successfully completed the experiment except one subject who had dropped out due to personal reasons. Pelvison group was provided with pelvic motions whereas no pelvic movement was allowed for pelvis-off group during 10 sessions of gait trainings in Healbot T. Electromyography (EMG) signals and interaction forces as well as the joint angles of the robot were measured. Gait parameters such as stride length, cadence, and walking speed were measured while walking on the ground without assistance of Healbot T after gait training on 1st, 5th, and 10th day. Result: Stride length significantly increased in both groups. Furthermore, cadence and walking speed of the pelvison group were increased by 10.6% and 11.8%. Although interaction forces of both groups except the thighs showed no differences, EMG signals from gluteus medius of the pelvis-on group increased by 88.6% during stance phase. In addition, EMG signals of biceps femoris, gastrocnemius medial, and gastrocnemius lateral of the pelvis-on group increased whereas EMG signals of the pelvis-off group except gastrocnemius lateral showed no difference after gait trainings. ⓒ The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http:// creat iveco mmons. org/ licen ses/ by/4. 0/. The Creative Commons Public Domain Dedication waiver (http:// creat iveco mmons. org/ publi cdoma in/ zero/1. 0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Open Access