When Arbacia punctulata spermatozoa are incubated in seawater containing ammonium hydroxide (pH 8.8), the sperm plasma membrane-bound guanylate cyclase is dephosphorylated, its electrophoretic mobility increases (from an apparent molecular mass of 160 to 150 kD), and its enzymatic activity decreases 3.5-fold. Transfer of these cells into ammonium-free seawater (pH 7.4) results in the rephosphor...

Cadmium sulphide (CdS) thin films were deposited onto glass substrates by chemical bath deposition (CBD) from a bath containing cadmium acetate, ammonium acetate, thiourea and ammonium hydroxide. The CdS films were annealed in air at various temperatures (350, 400 and 450 °C) for 60 minutes, and times (5, 15, 30, 45 and 60 minutes) at constant temperature (400 °C) in order to investigate the in...

The study was conducted to investigate the free radical scavenging activities of polysaccharide fractions extracted from the fruiting body of medicinal mushroom, Ganoderma lucidum (Fr.) P. Karst (Reishi) using different antioxidant capacity assays. Four intracellular polysaccharide fractions were obtained by the hot-water extraction and precipitation with ethanol, by ammonium oxalate extraction...

A sensitive method to directly measure the mass of inositol phosphates from biologic samples is described. The procedure uses ammonium sulfate gradient elution anion exchange column chromatography to isolate inositol monophosphate, bisphosphate, trisphosphate, and tetrakisphosphate. The isolated fractions are dephosphorylated and subsequently desalted by a novel approach using solid barium hydr...

The acidic properties of dealuminated Y-type zeolites were characterized by infrared (IR) spectroscopy, microcalorimetry, 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy and temperatureprogrammed desorption (TPD). Microcalorimetric measurements exhibited a unitbrm heat of adsorption ( 140 kJ/mol ) of ammonia on the strong Br6nsted acid sites. The differences in the a...

The objective of this study was to evaluate the tenderness of beef chuck and round muscles when enhanced with ammonium hydroxide and salt at different pump levels. A randomized, complete block design of 4 treatments and 3 muscles with 3 replications was used, with a total of 15 subprimals per treatment. Treatments included a 0% (CON), 15% (T15), 22.5% (T22), and 30% (T30) target pump. The trice...