The oxidative stress hypothesis of aging proposes that age-dependent progressive deteriorations are elicited by various reactive species (RS). RS are produced by various metabolic processes under normal and pathologic conditions. A less-documented source of RS generation is the cyclooxygenase (COX)-catalyzed prostaglandin pathway. Recent evidence indicates that COX may be one of the major metabolic sources of superoxide and hydroperoxides through the arachidonic acid cascade pathway. COX is the rate-limiting enzyme in this process generating prostaglandin E 2 (PGE 2 ), prostacyclin (PGI 2 ), and thromboxane A 2 (TXA 2 ). COX exists in two distinct isoforms: COX-1, a constitutive isoform that is detected in most tissues and contributes to the production of physiological levels of prostanoid, and inducible COX-2, produced in response to many proinflammatory stimuli, including several cytokines. In the present study, we attempted to assess the contribution of RS generation of the COX pathway contributing to overall oxidative status. Fischer 344 rats of 6, 12, 18, and 24 months of age were used in this study. We quantified RS generation, the activities and gene expression of COX in aged kidney. Results show that COX-derived RS generation was markedly increased with age in parallel to total RS. This increased RS generation was accompanied by increased COX activity. Data on gene expression of COX-2 corroborated with the changes in the protein and mRNA level of COX-2. It was concluded that a substantial amount of total RS was contributed by the age-related COX-dependent process, which was accompanied by the increased gene expression of COX-2 mRNA and protein levels with age. These results suggest that the upregulation of COX-2 during aging can be a major contributor to oxidative status in the aging process. The significance of our finding is that increased COX activity during aging may be the major cause underlying the inflammation process under oxidative stress.
Glass walls for exterior building can help save energy as increase inflow of natural sunlight. However, when sunlight directly reaches on floor, it can be occurred reflection glare, and visual discomfort. A blind can be in charge of preventing glare, but over prevention of sunlight affects increase of lighting energy. In this paper, we propose intelligent blind control system using electric venetian blind, which consists of multiple slats, and can be controlled slat angle and heights to prevent glare and to save lighting energy. The proposed system controls slat angle and heights of blind according to altitude of sun. Also, the system guarantees brightness on the floor by additional compensation of slat angle and heights of blind according to brightness on the floor measured by luminance meter.
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