In atherosclerosis, oxidative stress-induced vascular smooth muscle cells (SMCs) dysfunction is partially mediated by up-regulated NADPH oxidase (Nox); the mechanisms of enzyme regulation are not entirely defined. CCAAT/enhancer-binding proteins (C/EBP) regulate cellular proliferation and differentiation, and the expression of many inflammatory and immune genes. We aimed at elucidating the role...

Large-scale changes in ozone precursor emissions affect ozone directly in the short term, and also affect methane, which in turn causes long-term changes in ozone that affect surface ozone air quality. Here we assess the effects of changes in ozone precursor emissions on the longterm change in surface ozone via methane, as a function of the emission region, by modeling 10% reductions in anthrop...

Coflow and counterflow methane–air flames are simulated over a complete partially premixed regime in order to characterize the effects of dominant combustion modes (i.e., single-, two-, and three-stage combustion) on NOx emissions. Simulations employ a comprehensive numerical model that uses detailed descriptions of transport and chemistry (GRI-2.11 mechanism) and includes radiation effects. It...

Recent studies have shown that vapor-phase bioreactors containing the fungus Exophiala lecanii-corni can remove nitric oxide (NO) and volatile organic compounds efficiently from waste gas streams. However, when NH4 accumulates in the bioreactor, the NO removal efficiency abruptly drops to 20 %. To achieve high NOx removals in the bioreactors, low NH4 levels must be maintained, or a different ni...

Towards the end of the 1940s the air’s contamination began in Mexico. It just happened when Mexico starts its industrial growing. During these years the population increased notably. Industrial growing in the 1950s was carried through an urbanization process (Restrepo, 1992). Mexico City was the first because it had industries, services, government offices, culture attractions and higher educat...

Energetic particle precipitation (EPP) during the 2003–2004 Arctic winter led to the production and subsequent transport of reactive odd nitrogen (NOx =NO+NO2) from the mesosphere and lower thermosphere (MLT) into the stratosphere. This caused NOx enhancements in the polar upper stratosphere in April 2004 that were unprecedented in the satellite record. Simulations of the 2003–2004 Arctic winte...

Long-term observations of the reactive chemical composition of the tropical marine boundary layer (MBL) are rare, despite its crucial role for the chemical stability of the atmosphere. Recent observations of reactive bromine species in the tropical MBL showed unexpectedly high levels that could potentially have an impact on the ozone budget. Uncertainties in the ozone budget are amplified by ou...

There are many ways to reduce diesel engine exhaust emissions. However, NOx emission is difficult to reduce because the hydrocarbon (HC) concentration in a diesel engine is not sufficient for NOx conversion. Therefore, in order to create stoichiometric conditions in the De-NOx catalyst, a secondary injection system is designed to inject liquid HC into the exhaust pipe. The atomization and distr...

The basal activity of nitric oxide (NO) is reduced in spastic arteries of patients with vasospastic angina (VSA). Elevated concentrations of ADMA are associated with reduced NO production and impaired endothelium-dependent vasodilatation. The aim of this study was to elucidate the role of ADMA and its relationship to NO end-products (NOx; nitrate + nitrite) during coronary circulation in patien...

If adopted by EPA, proposed new regulations on stack emissions will force many utilities with coalfired boilers to reduce their NOx emissions to levels which are substantially lower then can be achieved with current low NOx burner technology. To meet these requirements, some utilities are anticipating the need to use selective catalytic reduction (SCR) for NOx control. New SCR catalysts under d...