Epidemiologic studies have reported that particulate matter with aerodynamic diameters ≤2.5 μm (PM) affect respiratory diseases, including asthma. The components and/or factors of PM that contribute to the exacerbation of asthma have not been identified. We investigated the effects of extracts of PM collected in Japan on the respiratory and immune systems. PM was collected from an industrial area and an urban area in December 2013. Airway epithelial cells and immune cells were exposed to aqueous or organic extracts of PM. Exposure to extracts from both areas, especially to organic extracts rather than aqueous extracts, caused a pro-inflammatory response via interleukin (IL) 6 production from airway epithelial cells, and it induced the maturation/activation of bone marrow-derived antigen-presenting cells via dendritic and epithelial cell (DEC) 205 and cluster of differentiation (CD) 86 expression and proportional changes in the constitution of the splenocytes. The extracts collected from the industrial area tended to show greater effects than those from the urban area. These results suggest that organic components of PM affect the respiratory and immune systems. These effects can differ by the collection areas. In addition, IL-6, DEC205, and CD86 can be predictive biomarkers for the respiratory and immune effects of ambient PM.
The production of bearings is focusing on polymers, such as polyether ether ketone (PEEK), a tough semi-crystalline thermoplastic polymer with excellent mechanical properties and polytetrafluoroethylene (PTFE), a material with low friction coefficient. The purpose of this study was to establish the properties of hybrid PEEK races – PTFE retainer bearings. Rolling contact fatigue tests were performed in order to investigate the wear properties of such components and the relation between load and rotation speed. It is concluded that by using a PTFE retainer, no wear occurs under thrust load ranging from 200N to 800N at 300rpm.
In this paper, the wear performance of hybrid radial bearing (PEEK-PTFE and alumina ball) was investigated. For effective operation of equipment in clean energy facilities environment, the PEEK-PTFE hybrid bearings was developed. Radial PEEK-PTFE hybrid bearings were produced by machining and their rolling contact fatigue (RCF) behavior under non-lubricated condition was carried out. PEEK accumulation layer with PTFE and graphite appeared on the bearing's inner ring under 600-3000 rpm rotation speed. Due to the self-lubrication of PEEK layer, the wear loss of hybrid bearing cycles was lower than in the case of neat PEEK radial bearing. Moreover, It was found that the thin PEEK layer protected the raceway from the friction heat and wear.
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