the role of manure and urea on yield and some fruit characteristics of strawberry cv. kurdistan were studied during 2002-2004 growing season. the experiment was a factorial one based on a randomized complete block design including four levels of urea(0, 50, 100, 150 kg/ha) and three levels of manure (0, 20, 40 t/ha) in three replications. the results showed that application of manure along with...

Recycling of urea within the renal medulla is known to play an important role in the capacity of the kidney to concentrate urine. This recycling occurs simultaneously through a tubular and a vascular route (i.e., through the loops of Henle and vasa recta, respectively). In the present study, transgenic mice with a selective deficiency in UT-B (the urea transporter protein expressed in descendin...

Leuthardt [1938a] and Bach [1939] have expressed the opinion that in addition to the ornithine cycle there are other mechanisms of urea synthesis in the mammalian liver. Leuthardt [1938a] found that liver of starved guinea-pigs forms urea more rapidly from glutamine than from NH4Cl. He concluded that NH3 cannot be an intermediate in the urea formation from glutamine and that there is a more or ...

Urea titration of RNA by urea is an effective approach to investigate the forces stabilizing this biologically important molecule. We used all atom molecular dynamics simulations using two urea force fields and two RNA constructs to elucidate in atomic detail the destabilization mechanism of folded RNA in aqueous urea solutions. Urea denatures RNA by forming multiple hydrogen bonds with the RNA...

1. The urea content of ileostomy effluent has been measured by the urease method as an indirect estimate of the urea concentration in the lumen of the normal ileum. 2. The plasma disappearance of intravenously administered[14C]urea was used to study intestinal urea breakdown. Normal subjects on high and low protein diets and patients with either excised (i.e. with ileostomies) or excluded colon...

We use polarization-resolved mid-infrared pump-probe spectroscopy to study the effect of urea on the structure and dynamics of water. Surprisingly, we find that, even at high concentrations of urea (8 M), the orientational dynamics of most water molecules are the same as in pure liquid water, showing that urea has a negligible effect on the hydrogen-bond dynamics of these molecules. However, a ...

This is the second of two articles that together aim to explore current understanding of the clinical value of measuring serum/plasma urea concentration. The main focus of the first article [1] was physiological topics, such as urea production and renal processing of urea. The causes of increased and reduced plasma/serum urea concentration were also discussed. The main focus of this second arti...

Density functional theory calculations were used to examine the role of the urease model complex [Ni2(bdptz)(micro-OH)(micro-H2O)(H2O)2](OTs)3(bdptz=1,4-bis(2,2'-dipyridylmethyl)-phthalazine; OTs=tosylate) in the degradation of urea. An elimination mechanism that converts urea to ammonium cyanate was investigated in detail. The lowest energy pathway involves urea coordination through the oxygen...

Animals may adapt to hyperosmolar environments by either osmoregulating or osmoconforming. Osmoconforming animals generally accumulate organic osmolytes including sugars, amino acids or, in a few cases, urea. In the latter case, they also accumulate 'urea-counteracting' solutes to mitigate the toxic effects of urea. We examined the osmoregulatory adaptation of Drosophila melanogaster larvae sel...

Hypertonicity increases urea transport independently of, as well as synergistically with, vasopressin in the inner medullary collect duct (IMCD). We previously showed that hypertonicity does not increase the level of cAMP in the IMCD, but it does increase the level of intracellular calcium. Since we also showed that hypertonicity increases both the phosphorylation and biotinylation of the urea ...