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Changes in Brain Activity of Rats due to Exposure to Fine Dust Using ¹⁸F-FDG PET
조윤호(Yun-Ho Cho),조규상(Kyu-Sang Cho),이왕희(Wang-Hui Lee),최재호(Jea-Ho Choi) 대한방사선과학회(구 대한방사선기술학회) 2022 방사선기술과학 Vol.45 No.3
Fine dust threatens human health in various forms, depending on the particle size, such as by causing respiratory, cardiovascular, and brain diseases, after entering the body via the lungs. The aim of this study was to correlate fine dust exposure with changes in brain blood flow in Sprague Dawley rats by using micro-positron emission tomography and elucidate the possibility of developing cerebrovascular diseases caused by fine dust. The subjects were exposured to an average fine dust (particulate matter 2.5) of 206.2 ± 7.74 to ten rats four times a day, twice a day for 90 min. Before the experiment, they were maintained at NPO to the maximize the intake of 18F-fluorodeoxy glucose(18F-FDG) and minimize changes in the 18F-FDG biomass depending on the ambient environment and body temperature of the rats. PET images were acquired in the list mode 40 min after injecting 18F-FDG 44.4 MBq into the rats tail vein using a micro-PET scanner pre and post exposure to fine dust. We found that the whole brain level of 18F-FDG standardized uptake value in rats averaged 5.21 ± 0.52 g/mL pre and 4.22 ± 0.48 g/mL post exposure to fine dust, resulting in a statistically significant difference. Fine dust was able to alter brain activity after entering the body via the lungs in various forms depending on the particle size.
Cho, Won-Jea,Le, Quynh Manh,Van, Hue Thi My,Lee, Kwang Youl,Kang, Bok Yun,Lee, Eung-Seok,Lee, Sang Kook,Kwon, Youngjoo WILEY-VCH Verlag 2007 Chem Inform Vol.38 No.43
<P>ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.</P>
( Yun Jeong Jeong ),( Hyun Ji Cho ),( Key Whang ),( In Seon Lee ),( Kwan Kyu Park ),( Jung Yoon Choe ),( Sang Mi Han ),( Cheorl Ho Kim ),( Hyeun Wook Chang ),( Sung Kwon Moon ),( Wun Jea Kim ),( Yung 영남대학교 약품개발연구소 2013 영남대학교 약품개발연구소 연구업적집 Vol.23 No.0
Matrix metalloproteinases-9 (MMP-9) plays an important role in the pathogenesis of atherosclerosis and migration of vascular smooth muscle cells (VSMCs) after an arterial injury. In this study, we investigated the potential molecular mechanisms underlying the anti-atheroscleroic effects ofmelittin, a major component of bee venom, in human aortic smooth muscle cells (HASMCs). Melttin significantly suppressed MMP-9 and MMP-2 secretion, as well as TNF-α-induced MMP-9 expression in the HASMCs. In addition, we found that the inhibitory effects of melittin on TNF-α-induced MMP-9 protein expression are associated with the inhibition of MMP-9 transcription levels. Mechanistically, Melittin suppressed TNF-α-induced MMP-9 activity by inhibiting the phosphorylation of p38 and ERK1/2, but did not affect the phosphorylation of JNK and Akt. Reporter gene and western blotting assays showed that melittin inhibits MMP-9 transcriptional activity by blocking the activation of NF-κB via IκBα signaling pathway. Moreover, the matrigel migration assay showed that melittin reduced TNF-α-induced HASMC migration. These results suggest that melittin suppresses TNF-α-induced HASMC migration through the selective inhibition of MMP-9 expression and provide a novel role of melittin in the anti-atherosclerotic action.ⓒ2012Elsevier Ltd. All rights reserved.
Fabrication of Field-Emitter Arrays using the Mold Method for FED Applications
Cho, Kyung-Jea,Ryu, Jeong-Tak,Kim, Yeon-Bo,Lee, Sang-Yun The Korean Institute of Electrical and Electronic 2002 Transactions on Electrical and Electronic Material Vol.3 No.1
The typical mold method for FED (field emission display) fabrication is used to form a gate electrode, a gate oxide layer, and emitter tip after fabrication of a mold shape using wet-etching of Si substrate. However, in this study, new mold method using a side wall space structure was developed to make sharp emitter tips with the gate electrode. In new method, gate oxide layer and gate electrode layer were deposited on a Si wafer by LPCVD (low pressure chemical vapor deposition), and then BPSG (Boro phosphor silicate glass) thin film was deposited. After then, the BPSG thin film was flowed into the mold at high temperature in order to form a sharp mold structure. TiN was deposited as an emitter tip on it. The unfinished device was bonded to a glass substrate by anodic bonding techniques. The Si wafer was etched from backside by KOH-deionized water solution. Finally, the sharp field emitter array with gate electrode on the glass substrate was formed.
RUS법에 의한 Micro-Crack을 가진 Ferrule의 주파수 특성 평가
백경윤,이길성,양순호,김성훈,조영재,민한기,양인영 朝鮮大學校 機械技術硏究所 2003 機械技術硏究 Vol.6 No.2
광섬유 정렬부품으로 사용되는 페롤은 극히 높은 정밀도를 요하는 제품으로서, 높은 치수 정밀도와 결함이 포함되지 않는 등 높은 신뢰성이 요구되는 제품이다. 이러한 페롤의 형상결함평가에 종래의 광학현미경 평가법과는 달리. 본 논문에서는 공명초음파법(ResonantUltrasound Spectroscopy)을 이용하고자 한다. 공명초음파법이란 결함이 없는 시험편을 기계적으로 진동시켰을 때의 공진 주파수와 시험편 내에 결함을 가지고 있을 때의 공명 주파수 양상을 비교 분석하여 결함유무를 검출해내는 방법이다. 본 연구에서는 양품과 크랙을 가진 시험편을 현장에서 직접 사용되고 있는 광학현미경에 의해 분류를 한 다음, 더욱 정확한 측정을 위해 SEM에 의해 다시 분류하였다. 각각에 대해 공진 주파수를 측정하였고, 이 데이터의 검증을 위해 FEM해석을 수행하였다. 실험으로부터 얻는 양품의 공진 주파수와 FEM해석을 통해 얻었던 양품의 공진 주파수의 오차는 1∼2%정도의 범위를 벗어나지 않음을 알 수 있었다. 또한 크랙에 대한 공진 주파수를 측정하여서, 양품의 공진 주파수와 비교를 행하였고, 이 데이터를 가지고 모드별로 히스토그램을 그려서, 그것으로부터 현장에서 실제로 이용 가능한 모드를 존재함을 확인하였다. The Ferrule which is used as the product optical fiber very precisely, is required high to set the optical axes of an dimensional precision, lack of defect and high expectation. Up to now the optical instrument has been used for the defect and shape inspection of the Ferrule, but in this paper we examined the detectable defect and expectation by using the Resonant Ultrasound Spectroscopy (RUS). The RUS is the measurement' which is to excite specimen and to inspect the difference of natural frequency pattern between acceptable specimen and specimen has some defects. In this paper, we classified specimens into three groups by using She optical instrument; acceptable specimen A-type, 3-type and specimen A-type which has crack. And we reclassified by Scanning Microscope to carry out the more exact measurement. We surveyed the resonant frequency of every specimen, and carried out the simulation from the explicit finite elements code, NasEran t o verify the experiment data. The average error between the resonant frequency of acceptable specimens which is obtained from experiment and that from FEM analysis is in the range of 1-2 percentage. Also, we measured the resonant frequency of specimen which has crack, and compared that of acceptable specimen. We drew histogram by using these data, and confirmed the available mode in the plant.
작업자 안전을 위한 영상센서 활용 인원 계수 시스템 개발
한재호(Jea-Ho Han),조윤호(Yun-Ho Cho),장철호(Cheol-Ho Jang),이주식(Ju-Sik Lee),이병철(Byeong-Cheol Lee),정종열(Jong-Yeol Jeong) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.11
인원 계수 시스템은 산업 현장 등 복잡한 구조 내에서 다양한 형태의 작업자(짐을 지고 있는 경우, 양 방향에서 오가는 경우 등)의 출입 및 재실인원 정보를 파악하기 위해 만든 안전장치이다. 본 논문에서는 이 시스템의 정확한 작동을 위해 CMOS 이미지 센서를 활용한 영상데이터 라벨링 기법, YOLO를 통한 영상AI학습 방법(Making Box), People Counting 알고리즘을 소개한다.