http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
PAN계 안정화섬유로부터 고기능성 활성탄소섬유의 제조 및 특성
임연수,유기상,문숙영,정윤중,김명수,함현식 한국세라믹학회 2003 한국세라믹학회지 Vol.40 No.5
안정화 PAN(Polyacronitrile)계 섬유를 이용하여 물리적인 방법과 화학적인 방법으로 활성탄소섬유(Activated Carbon Fibers)를 제조하고, 그 특성을 비교평가 하였다. 본 연구에서는 안정화 PAN계 섬유를 수증기 및 $CO_2$를 이용한 물리적 활성화와 KOH를 이용한 화학적 활성화에 의해 여러 등급의 활성탄소섬유를 제조하였고, 비표면적, 요오드흡착량, 미세구조, 세공구조 등을 측정하였다. 물리적 활성화 방법에는 수증기와 $CO_2$가 사용되었는데, 수증기활성화의 경우 99$0^{\circ}C$의 활성화 온도에서 1635 m$^2$/g의 비표면적을 나타내었고, $CO_2$ 활성화의 경우에는 99$0^{\circ}C$의 활성화 온도에서 671 m$^2$/g의 비표면적을 나타내었다. KOH를 이용한 화학적 활성화 방법에서는 KOH와 안정화 PAN계 탄소섬유의 비가 1.5 : 1인 경우 90$0^{\circ}C$의 활성화 온도에서 3179 m$^2$/g의 비표면적을 나타내었다. 물리적 활성화와 화학적 활성화로 제조된 활성탄소섬유의 질소흡착등온선의 결과로 보면 type I의 형태와 type I에서 type II로의 전이형태의 등온흡착곡선을 나타내었다. Activated carbon fibers were prepared from stabilized PAN fibers by physical and chemical activation to compare their characteristics. In this study, stabilized PAN fibers were activated by physical activation with steam and CO$_2$, and by chemical activation with KOH. The fabricated activated carbon fibers were evaluated and compared such as specific surface area, pore size distribution, pore volume, and amount of iodine adsorption. In the steam activation, a specific surface area of 1635 m$^2$/g was obtained after heat treatment at 990$^{\circ}C$. Otherwise, in the CO$_2$ activation, produced activated carbon fibers had been a specific surface area of 671 m$^2$/g after heat treatment at 990$^{\circ}C$. In chemical activation using KOH, a specific surface area of 3179 m$^2$/g was obtained with a KOH/ stabilized PAN fiber ratio of 1.5 : 1 at 900$^{\circ}C$. Nitrogen adsorption isotherms for fabricated activated carbon fibers showed type I and transformation from type I and II in the Brunauer-Deming-Deming-Teller (B.D.D.T) classification. Increasing specific surface area Increased the amount of iodine adsorption in both activation methods. Because the ionic radius of iodine was smaller than the interior micropore size of activated carbon fibers.
사람 호흡기 상피세포에서 Peroxiredoxin 2에 의한 Lipopolysaccharide에 유도된점액 발현과 Reactive Oxygen Species 생성의 억제
김준희,조수연,이상재,유기문,나형균,최윤석,배창훈,송시연,김용대 대한이비인후과학회 2021 대한이비인후과학회지 두경부외과학 Vol.64 No.12
Background and Objectives Peroxiredoxin (Prx) is an antioxidant enzyme involved in signalingpathway. Prx2 is the most abundant in mammalian gray matter neurons and has protectiverole under oxidative stress. MUC5AC and MUC5B are typical mucin genes in human airwayepithelial cells. Even if free radicals play a key role in chronic respiratory inflammatorydiseases, the effects of the Prx2 on mucin expression and oxidative stress are not clearly known. The purpose of this study is to investigate the effect of Prx2 on lipopolysaccharide (LPS)-inducedMUC5AC/5B expression and reactive oxygen species (ROS) in human airway epithelialcells. Subjects and Method In NCI-H292 cells and human nasal epithelial cells, the effects ofPrx2 on LPS-induced MUC5AC/5B expression and ROS production were investigated usingreverse transcriptase-polymerase chain reaction, real-time polymerase chain reaction, enzymelinked immunosorbent assay (ELISA) and flow cytometry analysis. Results MUC5AC, MUC5B mRNA expression and protein production were increased byLPS. ROS production was also increased by LPS. Prx2 suppressed the LPS-induced MUC5ACmRNA expression and protein production as well as ROS production. However, Prx2 did notinhibit MUC5B mRNA expression and protein production. N-acetylcysteine, diphenyleneiodonium,and apocynin also inhibited LPS-induced ROS production. Conclusion These results may show that Prx2 suppresses LPS-induced MUC5AC expressionvia ROS in human airway epithelial cells.