Removal activities, nitric oxide

Some controversy exists over the reactive species produced when nitrogen is passed through an R.f. or microwave discharge. Verbeke and Winkler investigated the reactions of active nitrogen with nitric oxide and ethylene and found that the amount of nitric oxide removed was greater than the maximum amount of HCN produced from ethylene. To account for this difference they postulated that vibrationally excited molecules were decomposing nitric oxide, viz. 

The reactions that occur to auto-exhaust emissions when exposed to plasma include oxidation of HCs, carbon monoxide, and partially diesel PM also. Nitric oxide (NO) can be oxidized by plasma to N02. Plasma alone, due to its oxidizing character, is not a viable NO control method. However, combinations of plasma with catalysts, referred to as plasma-assisted catalysts or simply plasma catalysts , have been suggested for NO reduction. The plasma is believed to show potential to improve catalyst selectivity and removal efficiency. Current state-of-the-art plasma catalysts have efficiencies comparable to those of active DeNO systems, removing about 50% of NO at a fuel economy penalty of less than 5% [85],... 

According to [96], electrochemical methods, especially the application of cyclic voltammetry, could be a powerful tool to find suitable catalysts for NO removal from combustion products. Investigation of electrocatalytic properties of vitamin B12 toward oxidation and reduction of nitric oxide was reported in [97]. The catalytic activity of meso-tetraphenyl-porphyrin cobalt for nitric oxide oxidation in methanolic solution and in Nafion film was reported in [98]. 

We believe that the /3 cell is a source of nitric oxide production by human islets because (1) IL-1 and IFN-induced nitric oxide production by human macrophages has not been clearly demonstrated (2) the cytokine combination of IL-1, IFN, and TNF induces the formation of nitric oxide by human islets either freshly isolated or cultured for 7 days at 25°C (a procedure which removes 80-90% of nonendocrine cells from the islet) and also by islets cryoperserved and (3) NADPH—diaphorase staining reveals that approximately 60-70% of human islet cells treated with cytokines stain for NADPH-diaphorase (J. A. Corbett and M. L. McDaniel, unpublished data). TTiis staining procedure has been shown to colocalize with nitric oxide synthase in a number of cells including rat islets (Corbett et al., 1993c), and nitric oxide synthase has been demonstrated to contain NADPH-diaphorase enzymatic activity (Dawson et al., 1991 Hope et... 

Activation of endothelial cell muscarinic receptors by acetylcholine (Ach) releases endothelium-derived relaxing factor (nitric oxide), which causes relaxation of vascular smooth muscle precontracted with norepinephrine, 10-8M. Removal of the endothelium by rubbing eliminates the relaxant effect and reveals contraction caused by direct action of Ach on vascular smooth muscle. (NA, noradrenaline [norepinephrine]. Numbers indicate the log concentration applied at the time indicated.)... 

Bal-Price A., Matthias A., and Brown G. C. (2002). Stimulation of the NADPH oxidase in activated rat microglia removes nitric oxide but induces peroxynitrite production. J. Neurochem. 80 73-80. 

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