it is extremely challenging to measure first-order rate coefficients for soil nitrate transformation processes directly, either in the laboratory or in the field. in this study, an improved inverse method was proposed to optimize the first-order rate coefficients by considering the intermediate changing processes of the integrated functions. a numerical experiment was designed to test the accur...

In this work, zeolite NaY was prepared by hydrothermal method. Then, silver ions were replaced in the zeolite NaY with silver nitrate (AgNO3) solution via using ion exchange (IE) method. The Manganese dioxide (MnO2) nanoparticles (9.3 and 15.8 wt %) for guest were deposited in the zeolite AgY(host) structure with Mn(NO3)2 aqueous and KMnO4 solutions by confined space synthesis (CSS) metho...

Plants differ in tissue localization of nitrate reduction and assimilation. Some species reduce nitrate primarily in the leaves, whereas other species localize nitrate reduction and assimilation in the roots. We determined how nitrate assimilation is partitioned among leaves, stems and roots of poplar (Populus tremula L. x P. alba L.) by comparing tissue differences in in vivo nitrate reductase...

Synthesis of nitrate reductase protein and increases in nitrate reductase activity occurred in cultures of the yeast Candida nitratophila when they were incubated in medium containing ammonium nitrate. Similar treatment with glutamine plus nitrate resulted in little increase in nitrate reductase activity, in cultures grown previously with reduced nitrogen compounds, and decreases in enzyme acti...

The characteristics of nitrate uptake and induction of nitrate reductase were studied in excised roots of corn (Zea mays L.). Upon initial exposure to nitrate, the low initial rate of nitrate uptake gradually increased until a steady uptake rate was achieved in 1 to 2 hours depending on the NO(3) (-) concentration. The pattern was observed over a wide range (0.2-5 mm) of nitrate concentrations ...

A study was done to relate the in vivo reduction of nitrate to nitrate uptake, nitrate accumulation, and induction of nitrate reductase activity in intact barley seedlings (Hordeum vulgare L. var. ;Numar'). The characteristics of nitrate uptake in response to both time and ambient concentration of nitrate regulated reduction and accumulation. Uptake, accumulation, and in vivo reduction achieved...

Heart mitochondria depleted of endogenous divalent cations by treatment with A23187 and EDTA swell in (a) K+ acetate or (b) K+ nitrate when an uncoupler is present. These mitochondria also exchange matrix 42K+ with external K+, Na+, or Li+ in a reaction that does not require respiration and is insensitive to uncouplers. Untreated control mitochondria do not swell in either medium nor do they sh...

Uptake of uranium (VI) ions using an anion exchanger resin, namely amberlite CG-400, was studied through this work in the presence of sulfate anions. Impact of various parameters including pH, contact time, initial concentration of uranium ions and intrusion with different anion contents (phosphate, chloride,sulfate, nitrate and fluoride) was examined on the sorption performance of the resin. A...

Dietary nitrate, through the enterosalivary nitrate-nitrite-NO pathway, can improve blood pressure and arterial stiffness. How long systemic nitrate and nitrite remain elevated following cessation of high nitrate intake is unknown. In 19 healthy men and women, the time for salivary and plasma nitrate and nitrite to return to baseline after 7 days increased nitrate intake from green leafy vegeta...