K+ plays a catalytic role in AHL Na+ reabsorption via Na+-K+-2Cl- cotransporter (NKCC2), recycling across luminal K+ channels, so that luminal K+ is not depleted. Based on models of the ascending Henle limb (AHL) epithelium, it has been hypothesized that NH4+ may also catalyze luminal Na+ uptake. This hypothesis requires that luminal NH4+ not be depleted, implying replenishment via either direc...

Macroalgae has bloomed in the brackish lake of Shenzhen Bay, China continuously from 2010 to 2014. Gracilaria tenuistipitata was identified as the causative macroalgal species. The aim of this study was to explore the outbreak mechanism of G. tenuistipitata, by studying the effects of salinity and nitrogen sources on growth, and the different nitrogen sources uptake characteristic. Our experime...

Transbranchial ammonia gradients and blood acid-base status have been examined in rainbow trout acclimated to fresh water (FW), 33% sea water (33% SW) and sea water (SW) and exposed to 1.0 mmol l-1 total ammonia (TAmm) at pH 7.9 for 24 h. At all three salinities trout maintained large negative (inwardly directed) NH3 and NH4+ gradients throughout the exposure, presumably by active excretion of ...

The leachates generated at Hong Kong landfill sites contain high strength of ammonium-nitrogen (NH4+-N) over 3,000 mg l(-1) and are generally inhibitive to most biological treatment processes. To remove the NH4+-N from the landfill leachates and also recover the nitrogen as a struvite fertilizer, a lab-scale study was performed to investigate the feasibility of NH4+-N removal and struvite cryst...

A bacterial strain F-5-2, isolated from soil and identified as Klebsiella pneumoniae, removed NH4+ completely in 24 h of aerobic cultivation in a medium containing 1 mg/ml of NH4NO3. However, 70% of the NO3- originally provided remained. When 100 microM Fe2+ was added to the medium, both NH4+ and NO3- were removed simultaneously and completely from the culture within 6 h of incubation. In addit...

The asymmetric unit of the title compound, NH4 (+)·C11H14N6O7P(-)·0.5H2O, contains one 3'-azido-3'-de-oxy-thymidine-5'amino-carbonyl-phospho-nate (ACP-AZT) anion, half of an NH4 (+) cation lying on a twofold rotation axis and in another position, occupied with equal probabilities of 0.5, an NH4 (+) cation and a water mol-ecule. The amide group of the ACP-AZT anion is disordered (occupancy ratio...

NH4+ caused a dose-related, rapid, and reversible inhibition of glucose-stimulated insulin release by isolated rat islets. It also inhibited glyceraldehyde-, Ba2+-, and sulfonylurea-stimulated insulun secretion. NH4+ failed to affect glucose utilization and oxidation, glucose-stimulated proinsulin biosynthesis, the concentration of ATP, AD, and AMP, and the intracellular pH. NH4+ also failed to...

The temperature dependence of the proton spin-lattice relaxation times of (NH4)2A1(S04)2, (NH4)2 M0O4, NH4NH2S03 and (NH4)2SnCl6 has been investigated in the temperature range 100— 500 K. The experimental results indicate that intra H-H dipolar interaction, modulated by reorientational motion of the ammonium ion, is the dominant relaxation mechanism between 100 and 200 K. The activation energie...

Nitrification of ammonia (NH4) is a critical component for improved systems of animal wastewater treatment. One of the most effective processes uses nitrifying microorganisms encapsulated in polymer resins. It is used in Japan in municipal wastewater treatment plants for higher nitrification rates, shorter hydraulic retention times (HRT), and lower aeration treatment cost. We evaluated whether ...

In this paper, (NH4)2S and Na2S were used as passivating agent for the sulphuration treatment of GaSb. Although the oxide layer can be removed by both (NH4)2S and Na2S, the etching rate of Na2S was faster than (NH4)2S, which caused the high RMS. After passivation treatment, PL instensity of GaSb increased, however, if the passivation time was too long, PL instensity would decrease. At low tempe...