A fast and highly sensitive ion chromatographic method using monolithic ODS columns was developed for the determination of nitrite (NO2-) and nitrate (NO3-) in seawater. Two monolithic ODS columns (50 mm x 4.6 mm i.d. + 100 mm x 4.6 mm i.d.) connected in series were coated and equilibrated with 5 mM cetyltrimethylammonium chloride (CTAC) aqueous solution. The column efficiency with 0.5 M NaCl a...

We tested the hypothesis that the time constants (τ) of postexercise T2* MRI signal intensity (an index of O2 delivery) and muscle [PCr] (an index of metabolic perturbation, measured by (31)P-MRS) in hypoxia would be accelerated after dietary nitrate (NO3 (-)) supplementation. In a double-blind crossover design, eight moderately trained subjects underwent 5 days of NO3 (-) (beetroot juice, BR; ...

Zinc oxide nanoparticles (ZnO NPs) have been widely used in consumer products, therapeutic agents, and drug delivery systems. However, the fate and behavior of ZnO NPs in living organisms are not well described. The purpose of this study was to develop a physiologically based pharmacokinetic model to describe the dynamic interactions of (65)ZnO NPs in mice. We estimated key physicochemical para...

The lanthanide(III) complexes [Ln(LH2)(NO3)3] 1-11(La-Er), 15(Y) and [Ln(LH2)(NO3)2(H2O)](NO3) 12-14 (Tm-Lu) of the tetraiminodiphenolate macrocycle L2- have been prepared by the transmetallation reaction between [Pb(LH2)(NO3)2] and Ln(NO3)3.nH2O. In these compounds, the uncoordinated imino nitrogens are protonated and are hydrogen bonded to the phenolate oxygens. The X-ray crystal structures o...

The dissolved nitrogen pool in aquatic systems is comprised of many different nitrogen forms, both inorganic and organic. Interaction among these nitrogen forms at the level of uptake and enzyme activity is, with the exception of NH4 + and NO3 , not completely understood. Nitrate reductase (NR) and urease (UA) activities in the marine diatom Thalassiosira weissflogii (Grunow) Fryxell et Hasle w...

A sequencing batch reactor (SBR) was operated to develop denitrifying bacteria that had a mean specific denitrification rate of 0.11 g NO3 -N/gVSS/day. Another system (an anaerobic digester) was operated to generate volatile fatty acids (VFAs) with the effluent concentration being measured to be 5655 ± 876 mg/L as acetic acid. Using the denitrifying biomass developed in the SBR and VFAs generat...

[1] In most climates on Earth, biological processes control soil N. In the Atacama Desert of Chile, aridity severely limits biology, and soils accumulate atmospheric NO3 . We examined this apparent transformation of the soil N cycle using a series of ancient Atacama Desert soils (>2 My) that vary in rainfall (21 to <2 mm yr ). With decreasing rainfall, soil organic C decreases to 0.3 kg C m 2 a...

The reactive uptake coefficients, γ, of NO3 onto aqueous solutions containing ions X) HSO3, SO3, HCOO-, CH3COO, and OHwere measured at 273 ( 1 K using a wetted-wall flow tube reactor. The values of HDl k (H ) Henry’s law coefficient, Dl ) diffusion coefficient in the liquid phase, and k ) second-order rate coefficient for the liquid phase reactions of NO3 with X-) for the reactive uptake of NO3...

Agricultural systems that receive high or low organic matter (OM) inputs would be expected to differ in soil nitrogen (N) transformation rates and fates of ammonium (NH4 þ) and nitrate (NO3 ). To compare NH4 þ availability, competition between nitrifiers and heterotrophic microorganisms for NH4 þ, and microbial NO3 2 assimilation in an organic vs. a conventional irrigated cropping system in the...