A quantitative method for the determination of urea in serum was studied. An ion chromatograph (IC) with a conductivity detector was used in this method, where the chromatograph was modified by placing an immobilized urease column between the injection loop and a guard column of the cation analysis column. Immobilized urease was prepared by the adsorption of urease on cedar sawdust with triethy...

Compartmentalized reaction networks regulating signal processing, communication and pattern formation are central to living systems. Towards achieving life-like materials, we compartmentalized urea-urease more complex urea-urease/ester-esterase pH-feedback into hydrogel spheres investigate how fuel-driven pH fronts can be sent out from these regulated by internal networks. Membrane characterist...

Micromolar levels of urea [1–20 mM] on surface micromachined polysilicon cantilever beams immobilized with the enzyme urease was studied. Urea hydrolyses to ammonia and carbon dioxide which are volatile in nature. Monitoring the change in resonance frequency of a urease immobilized cantilever beam during the course of urea hydrolysis, mediated by the immobilized enzyme can give us information o...

A novel method for the rapid modification of fullerene for subsequent enzyme attachment to create a potentiometric biosensor is presented. Urease was immobilized onto the modified fullerene nanomaterial. The modified fullerene-immobilized urease (C60-urease) bioconjugate has been confirmed to catalyze the hydrolysis of urea in solution. The biomaterial was then deposited on a screen-printed ele...

THE possibility of an error in the determination of urea in blood by urease methods was brought to our notice by the fact that figures obtained by the direct estimation of urea in human blood corpuscles were obviously too high. This error appears to have been first reported by Behre [1923], who observed that when the soya bean urease method was applied to whole blood the urea obtained was parti...

Acidic media trigger cytoplasmic urease activity of the unique human gastric pathogen Helicobacter pylori. Deletion of ureI prevents this activation of cytoplasmic urease that is essential for bacterial acid resistance. UreI is an inner membrane protein with six transmembrane segments as shown by in vitro transcription/translation and membrane separation. Expression of UreI in Xenopus oocytes r...

The study was composed of two parts. A one-factor design was adopted to investigate DMD, CPM, NDFD and ADFD of diet by total feces collection method in trial one. Twelve lambs were allotted randomly to 4 groups of 3 animals (replicates), which were fed with basal diet, basic diet plus 40 mg/kg urease inhibitor, urea diet, urea diet plus 40 mg/kg urease inhibitor. Experimental period consisted o...

soil enzyme activities can be used as indicators of soil quality for assessing the sustainability of agricultural ecosystems. the objective of this study was to determine the effects of barley residue input rate, burning, urea fertilizer and tillage management on activities of alkaline phosphatase and urease under field conditions, after a period of 90 days. the experiment was carried out based...

The presence and activities of urease genes were investigated in 49 clinical, food, and environmental Bacillus cereus isolates. Ten strains were shown to have urease genes, with eight of these strains showing growth on urea as the sole nitrogen source. Two of the urease-positive strains, including the sequenced strain ATCC 10987, could not use urea for growth, despite their capacities to produc...

We used a differential thermal detector in conjunction with an immobilized urease reactor to determine urea in serum. Samples (120 mul) are introduced into a flow stream and passed through an "adiabatic" column, which is packed with enough insolubilized urease to completely convert urea to ammonia and carbon dioxide. Measured temperature changes are directly proportional to the serum urea conce...