A Novel Synthetic Compound 3-Amino-3-(4-Fluoro-Phenyl)-1H-Quinoline-2,4-Dione (KR22332) Exerts a Radioprotective Effect via the Inhibition of Mitochondrial Dysfunction and Generation of Reactive Oxygen Species

PURPOSE: Acute side effects of radiation such as oral mucositis are observed in most patients. Although several potential radioprotective agents have been proposed, no effective agent has yet been identified. In this study, we investigated the effectiveness of synthetic compound 3-amino-3-(4-fluoro-phenyl)-1H-quinoline-2,4-dione (KR22332) as a radioprotective agent. MATERIALS AND METHODS: Cell viability, apoptosis, the generation of reactive oxygen species (ROS), mitochondrial membrane potential changes, and changes in apoptosis-related signaling were examined in human keratinocyte (HaCaT). RESULTS: KR22332 inhibited irradiation-induced apoptosis and intracellular ROS generation, and it markedly attenuated the changes in mitochondrial membrane potential in primary human keratinocytes. Moreover, KR22332 significantly reduced the protein expression levels of ataxia telangiectasia mutated protein, p53, and tumor necrosis factor (TNF)-α compared to significant increases observed after radiation treatment. CONCLUSION: KR22332 significantly inhibited radiation-induced apoptosis in human keratinocytes in vitro, indicating that it might be a safe and effective treatment for the prevention of radiation-induced mucositis.ope

The effect of oxygen functional groups on the electrical transport of multi-layered graphene oxide

학위논문 (박사)-- 서울대학교 융합과학기술대학원 : 나노융합학과, 2015. 2. 박영우.Graphene oxide (GO) has emerged as one of the active research fields as well as graphene. In early days, GO had been focused on obtaining good quality graphene. Nowadays, however, GO itself has been much attention due to various oxygen functional groups which can provide a facile method for hybrid structure, and applicability for energy device electrode by reduction to electrical conduction. Especially, Pd-doped GO is expected for hydrogen fuel cell electrode by providing large surface area and trap sites for well dispersed Pd nanoparticles. Although many conduction mechanism of GO already reported, a comprehensive description on electrical conduction of multi-layered GO (MGO) was not enough. In this thesis, the electrical conduction mechanism of MGO and Pd-decorated MGO (PdGO) are investigated as a function of annealing temperature and H2 gas pressure. To investigate the electronic transport mechanisms in MGO, the temperature-dependent electrical conductivity (σ(T)) has been measured as a function of annealing temperature (Ta). An individual MGO flake is gradually reduced as the thermal annealing temperatures Ta increases from 88 to 300 °C, reduction process of MGO flake upon heating is confirmed by X-ray photoelectron spectroscopy at each annealing stage. As Ta increases, σ(T) of the MGO increases. The σ(T) is well interpreted by variable-range hopping in disordered regions in series with activated conduction across small barriers. The charge localized states are formed for hopping with the oxygen functional groups in GO, and the small activation barriers with the domain boundaries between the clustered oxygen functional groups and graphitic region. Both the hopping and activation barrier resistances decrease systematically as the Ta increases. Afterwards, MGO and PdGO are electrically evaluated for adsorptive hydrogen pressure at room temperature. PdGO is made by Suzuki-Miyaura coupling reaction using the MGO and Pd acetate, and dispersed Pd nanoparticles are confirmed by high resolution TEM. A pressure-dependent electrical conductance of MGO and PdGO has been measured in situ during hydrogen gas exposure (up to 20 bar) and release processes. As H2 pressure increases, the electrical conductance of MGO is increases while that of PdGO is decreased. Using atomic force microscopy, X-ray photoelectron spectroscopy, and Fourier transform-infrared spectroscopy analysis, it was found that MGO reduction due to H2 accounts for the increase in electrical conductance of the MGO. For PdGO, an increase of OH groups was observed, which shows that PdGO was oxidized when exposed to high H2 pressure. The PdGO oxidation can be explained by a hydrogen spillover effect resulting in the decrease of electrical conductance.Abstract i 1. Introduction 1.1. Brief review of graphene 1 1.2. Overview of graphene oxide 4 1.3. Characterization of graphene oxide 1.3.1. XPS 9 1.3.2. FTIR 11 1.3.3. HRTEM 13 2. Charge transport mechanism 2.1. Schottky emission 18 2.2. Fowler-Nordheim tunneling 20 2.3. Poole-Frenkel conduction 22 2.4. Hopping conduction 24 3. The effect of oxygen functional groups on the electrical transport behavior of a single piece multi-layered graphene oxide 3.1. Introduction 29 3.2. Experimental 31 3.2.1. Device fabrication 31 3.2.2. Electrical measurement 32 3.3. Results and discussion 3.3.1. Thermal reduction 33 3.3.2. XPS spectra 36 3.3.3. Temperature-dependent conductivity of MGO 38 3.3.4. Temperature-dependent conductivity of FGO 46 3.4. Conclusion 49 4. Electrical Conduction of Palladium-decorated Multi-layered Graphene Oxide Effected by Hydrogen Dissociation 4.1. Introduction 54 4.2. Experimental 4.2.1. MGO and PdGO sheets fabrication 57 4.2.2. Device preparation 58 4.2.3. Electrical measurement 59 4.3. Results and discussion 4.3.1. Electrical conductance of pristine MGO at high Pressure H2 gas 60 4.3.2. XPS spectra of pristine MGO 62 4.3.3. Electrical conductance of PdGO at high Pressure H2 gas 64 4.3.4. XPS spectra of Pd 3d of PdGO 66 4.3.5. FTIR spectra of PdGO 69 4.4. Conclusion 72 5. Conclusion 77Docto

Lactobacillus casei 젓산탈수소 효소 유전자의 bacillus subtilis 에서의 발현

학위논문(석사) - 한국과학기술원 : 생물공학과, 1990, [ vi, 53 p. ]A lactate dehydrogenase (LDH) gene of Lactobacillus casei origin was transferred into Bacillus subtilis and its expression in its new host cells was observed. The ldh gene contained in EcoRI-BamHI fragment of pLS65 was transferred into its corresponding site of pUP638 and constructed a new plasmid pUL85. With pUL85 cells of E. coli and B. subtilis were transformed and constructed new transformants, E. coli JM83 (pUL85) and B. subtilis RM125 (pUL85) were developed. The new transformants were grown in LB broth and expression of ldh gene in the new host cells was observed. Both transformants produced LDH in accordance with their growth with maximum production at late-log phase. It was also found that the L. casei originated ldh gene expressed in the new host cells using its own promoter. The expression efficiency of ldh gene in B. subtilis was about 20 times higher than in E. coli and B. subtilis RM125 (pUL85) produced LDH protein up to 20-30% of the total cellular protein. When the L. casei ldh gene promoter was fused to another gene, a structural gene of B. sublilis endoglucanse, however, its promoter activity in B. sublilis was not strong and produced only a moderate amount of endoglucanase.한국과학기술원 : 생물공학과

Developing Research Infrastructure of Detection System for Ocean Radiation Monitoring

한국해양과학기술

Developing Research Infrastructure of Detection System for Ocean Radiation Monitoring

한국해양과학기술

A study on enhancing the characteristics of undoped ZnO thin films prepared by MOCVD

학위논문(석사) - 한국과학기술원 : 전기 및 전자공학과, 1996.2, [ ii, 59 p. ]한국과학기술원 : 전기 및 전자공학과

Optimal Cooperative Retransmission and Rate Control on Wireless Networks

Reduce both the number of retransmissions and the transmission time for each packet to get over the unreliability of the wireless medium. Due to the inherent unreliability of the wireless medium, any transmitted packets are subject to failto decode at the receiver. In this paper, we jointly consider both the cooperative retransmission and the transmission rate control in order to reduce both the number of retransmissions and the transmission time for each packet. We first propose an optimal retransmission scheduling scheme with the optimal transmission rate control. In addition, we propose an advanced scheme by taking the energy constraint into our consideration. By performing an extensive set of evaluations,we validate the proposed schemes.o decode at the receiver. In this paper, we jointly consider both the cooperative retransmission and the transmission rate control in order to reduce both the number of retransmissions and the transmission time for each packet. We first propose an optimal retransmission scheduling scheme with the optimal transmission rate control. In addition, we propose an advanced scheme by taking the energy constraint into our consideration. By performing an extensive set of evaluations,we validate the proposed schemes.11othe

SEA WATER PURIFICATION EQUIPMENT FOR SEAWATER BATTERY

다단 격벽 구조를 가지는 passive 해수 순환 공급 기

Studies on optimal drone operation for internet of maritime things

한국해양과학기술

Verticality 3D Monitoring System for the Large Circular Steel Pipe

석션버켓기초는 20m 이상의 수심 조건에서 경제적인 시공이 가능한 건설 공법이다. 석션버켓기초는 내부가 비어 있는 양동이가 뒤집어진 형태의 구조물을 목표지점에 위치시킨 후, 버켓 내의 공기나 물을 흡입하여 내/외부의 수압차이에 의한 관입력으로 기초를 설치한다. 안정성 확보를 위해 버켓의 수직도 확보는 필수적이다. 그러나 해저지반의 불균질성이나 편심으로 인하여 버켓의 기울어짐이 발생할 수 있다. 석션버켓기초는 현재 시공과정에서 관입/인발 작업 반복을 통해 수직도를 확보하는 방법이 일반적으로 적용되고 있다. 그러나 이 방법은 현장 작업자의 경험 및 숙련도에 의존적이며 수직도 확보에 비교적 장시간이 소모된다. 본 논문에서는 실시간 석션버켓 수직도 모니터링 시스템을 제안한다. 제안된 시스템은 수직도 데이터를 수집하는 센서부, 수집된 데이터를 처리하여 무선 전송해 주는 컨트롤러부, 원형강관의 수직도 정보를 실시간으로 보여주는 디스플레이부로 구성되어 있다. 제안된 시스템은 기울기 센서와 임베디드 컨트롤러를 활용하여 구현되었다. 제안된 시스템의 실험 결과 roll/pitch가 0.028% 이내의 오차로 측정이 가능함을 확인하였다. 또한, 제안된 시스템을 석션버켓기초 모형실험에 적용하여 수직도 정보의 실시간 확인이 가능함을 보였다.22Nkc