Iron oxide nanoparticles were synthesized by coprecipitation method using ammonia as precipitation agent. Most researchers usually add ammonia into the iron salt solution but in this work the salt solution drop wise has been added to the ammonia and the new obtained results were compared with those of other researches. Magnetic properties of nanoparticles were measured by VSM. The effect of rea...

In an earlier publication’ dealing with a micro method for the estimation of urea in blood, I also described a micro method for the estimation of ammonia in blood and in organic secretions. For the determination of the ammonia two analyses are made; in the first the total urea plus ammonia is determined; and in the second the urea alone after the ammonia has been removed by evaporating the bloo...

The values given in the literature for the ammonia content of the brain show wide variation (l-3). Most of these values are of doubtful reliability, since the methods of estimation have not generally taken into account the presence of labile acid amides such as glutamine, which are now known to occur in the brain and which easily liberate ammonia on treatment with alkalies under the conditions ...

The production of high levels of ammonia allows the human gastric pathogen Helicobacter pylori to survive the acidic conditions in the human stomach. H. pylori produces ammonia through urease-mediated degradation of urea, but it is also able to convert a range of amide substrates into ammonia via its AmiE amidase and AmiF formamidase enzymes. Here data are provided that demonstrate that the iro...

Most of the methods for the determination of urea in blood involve the use of the enzyme urease to hydrolyze the urea, since this reaction is specific. However, instead of crystalline urease (l), crude jack bean meal extracts are used. These extracts have been found to contain other enzymes besides urease, termed “ammonia-producing” enzymes, and their substrates, which may produce large quantit...

Most of the methods for the determination of urea in blood involve the use of the enzyme urease to hydrolyze the urea, since this reaction is specific. However, instead of crystalline urease (l), crude jack bean meal extracts are used. These extracts have been found to contain other enzymes besides urease, termed “ammonia-producing” enzymes, and their substrates, which may produce large quantit...

The values given in the literature for the ammonia content of the brain show wide variation (l-3). Most of these values are of doubtful reliability, since the methods of estimation have not generally taken into account the presence of labile acid amides such as glutamine, which are now known to occur in the brain and which easily liberate ammonia on treatment with alkalies under the conditions ...

In the course of some work on protein metabolism it became advisable to estimate urea in animal tissues. Although we were drawn somewhat to the urease method we felt compelled for two reasons to employ other technique. In the first place, it was quite apparent that owing to the relatively large amount of ammonia in the tissue samples, the urea estimations would have to be accompanied by determi...

This study was performed to evaluate the accuracy, validation and applicability of UV spectrophotometer (UV), Ion Chromatography (IC), and Detector tube (DT) methods for measuring ammonia (NH3) concentration in a swine confinement house and swine slurry storage tank. The mean values of NH3 emitted from the house and slurry were 5.333 ppm and 42.192 ppm for the IC method; 4.13 ppm and 36.29 ppm ...