1. Stable urea isotopes can be used to study urea kinetics in humans. The use of stable urea isotopes for studying urea kinetic parameters in humans on a large scale is hampered by the high costs of the labelled material. We devised a urea dilution for measurement of the distribution volume, production rate and clearance of urea in healthy subjects and renal failure patients using the inexpensi...

Calix[4]arenes substituted at their wide rim by four aryl urea residues (1) form hydrogen-bonded dimers in apolar solvents. Replacement of one urea residue by an acetamido moiety leads to calix[4]arene derivatives (5) which form hydrogen-bonded tetramers under the same conditions. Both self-assembly processes occur independently. Therefore, molecules have been prepared in which a tetra-urea cal...

The aim of this study was to evaluate the effects of balancing low protein diets for methionine and lysine on performance of early lactation Holstein cows under hot environmental temperature. Twenty one multiparous Holstein cows in early lactation were allocated to three experimental rations including, 1) High protein ration with 17.5% CP, 2) Medium protein ration with 16% CP and 12 g/d rumen p...

Phycocyanin, Phycoerythrin, Phytochrom, Circulardichroism, D enaturation The circulardichroism spectra (cd) of native and (partially) urea-denaturated C-phycocyanin (PC) in the spectral range 700-210 nm are presented. The large ellipticities observed in the chromophoric region of native PC are retained in the fully denatured state (8 M urea). This is similar to the behavior of the red form of p...

progressive usage of medicinal plants has necessitated their mass production using the minimum amounts of chemical inputs. to find out the effects of urea and pelleted animal manure and some micronutrients on yield and its components in pumpkin, a split plot experiment based on rcbd with three replicates was conducted at the research farm of abouraihan campus, university of tehran in 2011. the ...

Six potentially important wood adhesives for gluing southern pine and white oak flakeboards were evaluated for their perfonnances in steam-injection pressing and conventional platen pressing. Of the six resins tested, polyisocyanate resin perfonned well in both steam injection and conventional platen pressings. Phenol-fonnaldehyde (PF) and melamine urea-fonnaldehyde (MUF) resins perfonned poorl...

The reaction of P-diketones 1 with phenyl hydrazine afforded 5-aryl-3-(1- methyl-5-nitro-2-imidazoly1)-1-phenylpyrazole (2) and 3-aryl-5-(1-methyl-5- nitro-2-imidazoly1) -1-phenylpyrazole (3). The reaction of diketones (1) with urea in the presence of p-toluenesulfonic acid gave 4-(or 6-)aryl-6-(or 4-)(1-methyl- 5-nitro-2-imidazolyl)-1-(lH)pyrimidones (4). The structures of all compounds w...

Exhaled breath condensate (EBC) analyses promise simple and noninvasive methods to measure airway biomarkers but pose considerable methodological challenges. We utilized mass spectrometry to measure EBC purine biomarkers adenosine and AMP plus urea to control for dilutional variability in two studies: 1) a cross-sectional analysis of 28 healthy, 40 cystic fibrosis (CF), and 11 asthmatic childre...

Controlled-release urea (CRU) and normal have been shown to improve yield nitrogen use efficiency (NUE) in rice. However, the effects of combined fertilizers (CRU urea, at different N ratios) on rice yield, temperature solar radiation utilization (TSRUE) NUEs remain unclear. In this study, CRU with release periods 60 days 100 were mixed ratios 7:3, 6:4, 5:5, 4:6 3:7 applied during rice-growing ...