The aims of this study were 1) to determine whether transfer of blood urea to the gastrointestinal tract (GIT) or the efficiency of capture of urea N within the GIT is more limiting for urea N salvage, and 2) to establish the relationship between plasma urea concentration and recycling of urea N to the GIT. We used an i.v. urea infusion model in sheep to elevate the urea entry rate and plasma c...

1. Five monotocous and two ditocous Scottish Blackface ewes with indwelling catheters in an umbilical artery and vein of one foetus only and in both maternal jugular veins were used. 2. Experiments were conducted over a period of 2 d when [14C]urea was infused intravenously over 9 h into either the mother or foetus, separate days being used for each infusion. Two series of experiments were comp...

Urea granulation is favored over prilling due to the problems associated with prilling. Tumbling agglomeration technique is employed in pan granulator. Product with wide size range can be produced by playing with only few parameters like binders (water and urea solution), ratio of binders, rpm of pan, granulation time and angle of inclination. Urea granulation is studied at laboratory scale usi...

abstract quantitative investigation of effects of range management treatments on different soil and water components in rangeland ecosystems has been rarely taken into account. in the present research, the kodir summer rangeland in the southeast nowshahr in mazandaran province was selected for studying effects of open grazing and exclosure managements on infiltration, runoff and microrelief. ex...

1. The activities of enzymes of the urea cycle [carbamoyl phosphate synthetase, ornithine transcarbamoylase, argininosuccinate synthetase, argininosuccinase (these last two comprising the arginine-synthetase system) and arginase] have been measured in control, alloxan-diabetic and glucagon-treated rats. In addition, measurements were made on alloxan-diabetic rats treated with protamine-zinc-ins...

It has traditionally been assumed that the urea cycle serves primarily to dispose of potentially toxic ammonia resulting from the catabolism of endogenous and dietary protein. Bicarbonate is also a substrate for the first enzymatic step of the urea cycle, catalysed by CPS. In recent years, it has been suggested that during the complete oxidation of dipolar amino acids, a proton is consumed from...

Ureido-functionalized compounds play an indispensable role in important biochemical processes, as well chemical synthesis and production. Isocyanates, KOCN particular, are the preferred reagents for ureido functionalization of amine-bearing compounds. In this study, we evaluate potential urea a reagent to graft groups onto amines at relatively low temperatures (<100 °C) aqueous media. Urea i...

Cultures of Escherichia coli B and K-12 produce urea during growth in minimal medium. Results of isotopic labeling experiments were consistent with the sole source of urea being from the conversion of arginine to putrescine. Since E. coli itself has no demonstrable urease activity, the rate of urea production is a measure of the flux through the arginine to putrescine pathway.

For determination of the dynamics of parotid urea secretion in conscious sheep, a previously standardized transit time ultrasonic flow metering system was used to measure bilateral parotid flow. Six ewes fed for ad libitum consumption were prepared under halothane anesthesia with ultrasonic probes around both parotid ducts; these ducts were also cannulated orally. After probe encapsulation (8 d...

long –term use of some of insecticides on rice striped stem borer (chilo suppressalis walk.) and for the reason the urgency of use of new suspension insecticide an experiment carried out, in paddy fields under condition at rice research institute in rasht, iran.treatments were as follow;1-fipronilg in first generation 2-fipronil g. in second generation 3-fipronil sc in first generation 0.5 lit....