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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.
머루종자의 적정 추출조건 및 추출 분획물의 Free Radical 소거능 효과
김난영(Nan-Young Kim),김영국(Young-Kuk Kim),배기자(Ki-Ja Bae),최재호(Jae-Ho Choi),문제학(Jea-Hak Moon),박근형(Geun-Hyung Park),오덕환(Deog-Hwan Oh) 한국식품영양과학회 2005 한국식품영양과학회지 Vol.34 No.6
식품 산업에서 발생되는 부산물의 가치를 재고하는데 있어서 머루 종자 에탄올 추출물을 대상으로 free radical 소거능을 탐색하여 머루종자의 기능성을 찾고자 본 실험을 수행하였다. 그 결과, 추출수율은 에탄올 농도, 추출온도 및 시간에 따라 전반적으로 4~12%를 나타내었으며 90% 에탄올로 70℃에서 12시간 추출한 추출물의 수율은 11.9%로 가장 높았지만 free radical 소거능(RC_(50))은 40.42 ㎍/mL로 나타났다. 그러나 70% 에탄올로 70℃에서 6시간 추출을 하였을 때 추출수율은 6.9%를 나타냈지만 RC_(50)은 20.93 ㎍/mL로 가장 높았고 총 페놀 함량도 330.71 mg GAE/g으로 가장 높게 나타났다. 본 연구결과, free radical 소거능이 높을수록 총 페놀 함량이 가장 높은 것으로 나타났으며 머루종자 에탄올 추출물의 free radical 소거능이 총 페놀 함량과 밀접하게 관련이 있는 것으로 나타났다. 한편, 70% 에탄올을 70℃, 6시간 추출물로부터 유기 용매별로 순차적으로 분획한 결과, 추출수율은 폴리페놀 화합물들을 많이 함유하고 있는 ethyl acetate 분획층에서 약 28%로 높았으며, RC_(50)도 ethyl acetate 분획층에서 8.65 ㎍/mL로 가장 높았고 총 페놀 함량도 ethyl acetate분획층에서 636.77 mg GAE/g으로 가장 높게 나타났다. Wild grape is a traditional medicine plant in north-eastern part of Asia and has been known to have healing properties for various illnesses. This study was to determine the optimum extraction condition and antioxidant activity of ethanol extracts of wild grape (V. coignetiae) seed. Also, organic solvent fractions of hexane, chlo- roform, ethyl acetate and butanol were obtained from the ethanol extract of wild grape seed at different temperatures. Total ethanol extraction yield of wild grape seed ranged from 4% to 12% depending on the ethanol concentration, extraction temperature and time condition. The highest extraction yield of 11.9% was obtained at 90% ethanol condition for 12 hour at 70℃. However, the strongest free radical scavenging effect (RC_(50)) with 20.93 ㎍/mL was observed in 70% ethanol extract of wild grape seed extracted for 6 hour at 70℃, while RC_(50) with 40.42 ㎍/mL was observed in 90% ethanol extract for 12 hour at 70℃. Antioxidant activity of ethanol extracts of wild grape seed increased as total phenol contents increased. Among each fraction obtained from organic solvents, ethyl acetate fraction was found to have the strongest RC_(50) (8.6 ㎍/mL) and 636.77 mg GAE/g phenol contents.
康悳一,金容奭,崔在皓 弘益大學校 科學技術硏究所 1997 科學技術硏究論文集 Vol.8 No.-
One of the requirements of a sensing system for feedback control of gas metal arc welding(GMAW) is the capability to determine the metal-transfer mode. Beacause the operating boundary for the desired transfer mode. expressed as a function of mass input, may vary due to conditions beyond the control of the system, a means of deteccting the transfer mode during welding is necessary. To observe the metal transfer, Our reaerch utilize the LBLS(Laser Back Lingtening System). LBLS is used He-Ne Laser as the Backlightening source. He-Ne laser is expanded and spatially filtered into a 20mm diameter collimated beam and used to illuminate the object represented by an opaque sphere. Thus it is be used to form a shadowgraph of the sphere. By using the LBLS, we know that welding current is main factor of metal transfer. Approached to optimum metal transfer, we used pulsed current GMAW method. But pulsed current GMAW has the problem to determine new welding condition. We study the proper welding codition for the pulsed current GMAW.