As nitric oxide is considered a mediator of liver oxidative metabolism during sepsis, we studied the effects of exogenous nitric oxide, produced by NO-donor, (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (NOR-3), on cell viability, urea biosynthesis and oxygen consumption in rat hepatocyte cultures. Nitric oxide release from NOR-3 was studied using 4,5-diaminofluorescein diacetate...

Graphene sheets doped with nitrogen were produced by the reduction-expansion (RES) method utilizing graphite oxide (GO) and urea as precursor materials. The simultaneous graphene generation and nitrogen insertion reactions are based on the fact that urea decomposes upon heating to release reducing gases. The volatile byproducts perform two primary functions: (i) promoting the reduction of the G...

Methods for directly estimating the ratio of two probability density functions without going through density estimation have been actively explored recently since they can be used for various data processing tasks such as non-stationarity adaptation, outlier detection, conditional density estimation, feature selection, and independent component analysis. However, even the state-of-the-art densi...

Platinum group metal-free catalysts have been intensively investigated in the last decades as an alternative to platinum with aim of lowering cost polymer electrolyte fuel cells. In particular, iron-nitrogen-carbon (Fe-N-C) has proved be most active towards oxygen reduction reaction. For practical application, a hierarchical pore structure is required, micropores favouring creation sites and la...

This study is firstly a short review of the types of exhaust systems predicted for Euro 4 (2005) and Euro 5 (2008), particularly focussed on the effects of combined NOx (nitrogen oxides) and PM (particulate matter) aftertreatment systems. Secondly, it explores in detail the implications of using a liquid secondary water-based fuel of urea on board heavy duty diesel vehicles in Europe as a basis...

To explore the role of urea in the urinary concentrating mechanism, the contents of vasa recta, Henle's descending limbs and collecting ducts were sampled by micropuncture of the renal papilla before and after infusion of urea in 10 protein-depleted rats. Eight protein-depleted rats not given urea were similarly studied as a control group. After urea administration, osmolality and the concentra...

In elasmobranch fishes, urea occurs at high concentrations (350-600 mM) in the body fluids and tissues, where it plays an important role in osmoregulation. Retention of urea by the gill against this huge blood-to-water diffusion gradient requires specialized adaptations to the epithelial cell membranes. Experiments were performed to determine the mechanisms and structural features that facilita...

antranilic acid is an intermediate material which we can produce by hofmann's rearrangement reaction. in this process phithalimide is a main reactant. one procedure for produceing phthalimide is the reaction of phithalic anhydride with urea in the presence of acetic acid. in this research, the kinetics of this reaction was studied at 115 c. we found that the reaction of phthalic anhydride ...