The objective of this study was to determine rates of ammonia desorption from sediment dust and ammonia levels in airborne dust in animal houses in order to explore the nature of ammonia in the dust particles. This is assumed to be important for obtaining better understanding of the role of dust in the perception of odor and the development of respiratory diseases in farmers’ lungs. Sediment du...

Phenylalanine ammonia-lyase, which irreversibly deaminates phenylalanine and tyrosine, markedly inhibited the growth of human leukemic and murine L5178Y lymphoblasts in vitro but had a negligible effect on resting (nondividing) normal lymphocytes. These studies also demonstrated that phenylalanine ammonia-lyase inhibited DNA synthesis in leukemic cells at least as effectively as did asparaginas...

This strongly alkaline chemical is widely used in industry as a feed stock for nitrogen-based chemicals such as fertilizers, plastics and explosives (ATSDR, 1990). Ammonia is also used as a refrigerant. The general public is exposed by off-gasing from cleaning solutions containing aqueous ammonia. Household ammonia solutions contain 5-10% ammonia in water while industrial strength can be up to ...

The weak base ammonia inhibits aggregation and culmination of wild-type amoebae of Dictyostelium discoideum. Here we have examined its effect on a series of 'slugger' mutants previously assigned to 10 complementation groups, and so-called because they remain as slugs for extended periods. We show that the mutants accumulate normal levels of ammonia and hence may be abnormally susceptible to the...

Through dedication and intelligent research, Haldor Topsøe’s name has become synonymous with efficient and profitable ammonia production and has set the standard for ammonia catalysts and technology. We build upon this legacy with the introduction of an ammonia synthesis catalyst that delivers the highest performance ever – KM 111. KM 111 is a magnetite-based catalyst developed for optimal perf...

Thermodynamic models predict that sulfate aerosol (S(VI) ≡ H2SO4(aq)+HSO−4 +SO 2− 4 ) should take up available ammonia (NH3) quantitatively as ammonium (NH+4 ) until the ammonium sulfate stoichiometry (NH4)2SO4 is close to being reached. This uptake of ammonia has important implications for aerosol mass, hygroscopicity, and acidity. When ammonia is in excess, the ammonium–sulfate aerosol ratio ...

The transfer of ammonia in carbamoyl phosphate synthetase (CPS) was investigated by molecular dynamics simulations and experimental characterization of mutations within the ammonia tunnel. In CPS, ammonia is derived from the hydrolysis of glutamine and this intermediate must travel approximately 45 A from the site of formation in the small subunit to the site of utilization in the large subunit...

Background. The decline of submerged plant populations due to high heavy metal (e.g., Cu) levels in sediments and ammonia nitrogen (ammonia-N) accumulation in the freshwater column has become a significant global problem. Previous studies have evaluated the effect of ammonia-N on submerged macrophytes, but few have focused on the influence of sediment Cu on submerged macrophytes and their combi...

Brain edema, due largely to astrocyte swelling, and the subsequent increase in intracranial pressure and brain herniation, are major complications of acute liver failure (ALF). Elevated level of brain ammonia has been strongly implicated in the development of astrocyte swelling associated with ALF. The means by which ammonia brings about astrocyte swelling, however, is incompletely understood. ...

The soil-dwelling nematode Caenorhabditis elegans is a bacteriovorous animal, excreting the vast majority of its nitrogenous waste as ammonia (25.3±1.2 µmol gFW(-1) day(-1)) and very little urea (0.21±0.004 µmol gFW(-1) day(-1)). Although these roundworms have been used for decades as genetic model systems, very little is known about their strategy to eliminate the toxic waste product ammonia f...