|
|
|
Registros recuperados: 113 | |
|
| |
|
| |
|
| |
|
| |
|
|
Kiehl,J.C.; Silveira,R.I.; Brito Neto,J.. |
The effect of rate and method of urea application on the yield of common beans (Phaseolus vulgaris L., cv. IPA-1) was evaluated on a Red-Yellow Latosol (Psamentic Haplortox) of Arapiraca and on a Solodic Planosol (Ustalf) of Igaci, both sandy-clay-loams located in the State of Alagoas, Brazil. Rates of 30,60 and 90 kg N/ha were applied placing the urea totally in the furrow at planting time; totally sidedressed twenty days after planting, mixed or not with the soil; or 1/3 of the amount in the furrow at planting plus 2/3 sidedressed twenty days after planting, mixed or not with the soil. Bean yield responses to nitrogen followed quadratic equations. In the Red-Yellow Latosol response to nitrogen occurred up to the rate of 66 kg N/ha, while in the Solodic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bean; Urea; Nitrogen; Method of application. |
Ano: 1993 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161993000200013 |
| |
|
| |
|
| |
|
| |
|
|
The effect of urea on biomimetic aggregates (aqueous and reversed micelles, vesicles and monolayers) was investigated to obtain insights into the effect of the denaturant on structured macromolecules. Direct evidence obtained from light scattering (static and dynamic), monolayer maximum isothermal compression and ionic conductivity measurements, together with indirect evidence from fluorescence photodissociation, fluorescence suppression, and thermal reactions, strongly indicates the direct interaction mechanism of urea with the aggregates. Preferential solvation of the surfactant headgroups by urea results in an increase in the monomer dissociation degree (when applied), which leads to an increase in the area per headgroup and also in the loss of... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Urea; Denaturation; Surfactants; Macromolecular structure. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000200004 |
| |
|
|
Goeyens, L.; Kindermans, N.; Yusuf, M.A.; Elskens, M.. |
Several earlier studies underpin the important role of dissolved organic matter and more particularly urea in phytoplanktonic nitrogen uptake fluxes. Generally, the determination of urea concentrations relies on the formation of an imidazolone-thiosemicarbizide complex, a complexation which requires very accurate temperature control when carried out at high temperature. It is also possible, however, to obtain reliable results with a room temperature procedure. The measured abundances for both complexation at high temperature (85 degree C, 20 min) and at ambient temperature (22 degree C, 72 h) are closely comparable. Lower values are observed for temperatures <10 degree C though. Moreover, a comparison of both techniques reveals similar precision... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dissolved organic carbon; Sea water; Temperature; Urea; Water analysis. |
Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7858 |
| |
|
| |
|
|
CORTADA,Carmen Neusa Martins; LUCCI,Carlos de Sousa; GONZALEZ,Rodrigo Alonso Forero; VALENTIN,Renato; MATTOS,Carla Balzano de. |
The effect of increased plasma urea levels on reproductive parameters of Santa Ines Brazilian breed rams (Ovis aries) was determined during two phases, 60 days in length each. During the first phase, 18 animals divided into three blocks according to scrotal circumference were submitted to the following treatments: diet A1- with nitrogen levels according to ARC (1980); diet B1 - nitrogen levels 133% higher than A1; and diet C1 - nitrogen levels 166% higher than A1. During the second phase, 12 animals divided into two groups received diet A2- with nitrogen levels according to ARC (1980), and diet B2 - nitrogen levels 200% higher than diet A2, respectively. The increase in protein equivalents was obtained by adding 20, 40 and 60 g of feed grade urea to... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Urea; Semen; Reproduction; Rams; Feed Ration. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-95962000000600007 |
| |
|
| |
|
|
Person, Jeannine; Lamers, A; Le Roux, Annick; Severe, Armelle; Boeuf, Gilles; Mayer Gostan, N. |
Turbot juveniles were exposed to four ammonia concentrations [0.17 (L), 0.34 (M), 0.73 (MH) and 0.88 (H) mgl(-1) NH3-N] for different exposure durations (28 days minimum to 84 days). Their physiological status and growth performances were compared to a control group [0.004 (C) mgl(-1) NH3-N]. No growth was observed in the H group, and by day 57, mass increase in the MH group was only 15% of that in group C. During the first month growth in the L group was similar to that in control group while it was lower (33%) in the M group; afterwards the L and M groups had a similar growth (half that of controls). Accumulation of total ammonia nitrogen (TA-N) in plasma was dependent on ambient ammonia concentrations. Plasma urea levels in ammonia-exposed fish were... |
Tipo: Text |
Palavras-chave: Urea; Total ammonia nitrogen; Scophthalmus maximus; Ion regulation; Cortisol; Chronic toxicity. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-618.pdf |
| |
|
|
Antonelli,Alexandre Coutinho; Mori,Clara Satsuki; Soares,Pierre Castro; Kitamura,Sandra Satiko; Ortolani,Enrico Lippi. |
Twelve yearling Girolando, rumen-fistulated steers never fed with urea before, were distributed randomly in 2 groups of 6 animals each. Both groups were administered intraruminally a single dose (0.5 g/kg BW) of extruded (G1) or prilled (G2) urea to induce ammonia poisoning. The clinical picture was followed for the next 240 min. Besides the classic signs the present study found 3 new additional sign: dehydration, hypothermia and ingurgitated episcleral veins. Convulsion, considered the definite sign, was seen in 5 out of 6 animals from both groups. One steer (G1) had only fasciculation, while another (G2) developed typical clinical signs, but not convulsion, and recovered spontaneously without treatment. The appearance of clinical signs such as muscle... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Urea; Ammonia poisoning; Clinical picture; Cattle. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-95962004000100010 |
| |
|
|
Alves,Marilia; González,Félix; Carvalho,Nelcy; Mühlbach,Paulo; Lima,Verônica; Conceição,Tiago Reis; Wald,Vera. |
Soybean by-products are currently used in Rio Grande do Sul, Brazil, as a source of protein in dairy cows. However, the high protein breakdown of this feed source in the rumen causes loss of the intrinsic quality of the protein and increases plasma urea with deleterious consequences to animal metabolism. Thermal treatment of soybean can overcome this limitation. The aim of this study was to evaluate the metabolism of dairy cows fed with thermally treated soybean and raw soybean, through the analyses of the metabolic profile of plasma and milk. Twelve Holstein cows in mid-lactation period were studied using four treatments: commercial concentrated of protein, soybean meal, raw soybean and roasted soybean. Protein and urea levels in milk were measured in... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Metabolic profile; Roasted soybean; Dairy cows; Milk; Protein; Urea. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782004000100037 |
| |
|
|
Silva,Hunaldo Oliveira; Fialho,Elias Tadeu; Freitas,Rilke Tadeu Fonseca de; Lima,José Augusto de Freitas; Logato,Priscila Rosa Vieira; Schoulten,Neudi Artemio. |
It was intended with the present work to verify the effect of phytase on the performance, bone mineralization and content of plasma urea of swine. 80 swine (30 ± 3.1 kg/LW), crossbred (LD x LW) males and females, allocated to a randomized block design (RBD) with four treatments and five replicates. The treatments consisted of a growing swine diet on the basis of corn, soybean meal and defatted rice bran (DRB) supplemented with four levels of phytase (0, 400, 800 and 1200 FTU/kg) The diet was formulated to meet the requirements of growing swine except for available calcium and phosphorus, the levels of which were 0.64 and 0.25%, respectively. The enzyme phytase utilized was Natuphos 5000. Over the experimental period every eight days, blood of two animals... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enzyme; Minerals; Plasma; Urea. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542004000600028 |
| |
|
|
Yagi,Renato; Ferreira,Manoel Evaristo; Cruz,Mara Cristina Pessôa da; Barbosa,José Carlos; Araújo,Luiz Alberto Navarro de. |
The interdependence between the C and N cycles is reflected by the levels of soil organic matter (SOM). SOM and organic C levels in water soluble (C-WS) humic acids (C-HA), fulvic acids (C-FA), and humin fractions (C-H) were evaluated through the classic chemical fractionation method in samples of a Rhodic Eutrudox from a randomized blocks experimental design, with split-split-plots using five nitrogen sidedressing levels for corn (0; 60; 120; 180; and 240 kg ha-1 N) as the main treatment, two crop sequences (corn-corn and soybean-corn) as the secondary treatment, and two sampling depths (0 to 0.2 and 0.2 to 0.4 m) as a sub-subtreatment. Nitrogen fertilization did not affect SOM levels, but favored the synthesis of substances in the C-HA fraction. There... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Humic acids; Humin; Urea; Corn; Soybean. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000400011 |
| |
|
|
Toledo de Oliveira,Tânia; Nagem,Tanus Jorge; Matos Lopes,Renato; Machado,Hussein; Jóia de Mello,Vanessa; Queiroga de Lima,Ednaldo; da Silva Martins,Eliene. |
El presente trabajo tiene como objeto verificar la acción de tres dosis del colorante Monascus sobre el metabolismo de la albúmina, urea, creatinina y ácido úrico en conejos de ambos sexos. Se usaron conejos de la raza Nueva Zelanda, obtenidos del Departamento de Cunicultura de la Universidad Federal de Viçosa (Brasil) de unos 55 días de edad y que pesaban cerca de 1700 g al momento del experimento. Los animales fueron divididos por sexo constituyéndose cuatro grupos de cinco animales cada uno, que recibieron el colorante Monascus en las dosis de 24, 48 y 60 mg/kg. El grupo control recibió solamente ración alimenticia. Los animales recibieron, diariamente, durante 28 días, las cápsulas que contenían el colorante Monascus en las respectivas dosis. Se... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Monascus; Albúmina sérica; Creatinina; Urea; Ácido úrico. |
Ano: 2005 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-29572005000400003 |
| |
|
|
Pedraza G,Carlos; Mansilla M,Alberto; Merucci D,Fabio; Pinedo,Pablo; Contreras C,Horacio. |
El presente estudio se realizó utilizando una base de datos del Servicio de Control Lechero de la empresa Bioleche Ltda., Los Ángeles, Chile. La información fue analizada mediante un modelo matemático que consideró como variable dependiente el nivel de urea en función de los factores: número ordinal de parto, época de parición, nivel de proteína de la leche, nivel de producción diaria de leche, recuento de células somáticas (RCS) y las interacciones entre los factores mencionados. El contenido de urea (mg 100 mL-1) en vacas de primer y de segundo o más partos fue 29,07a y 33,35b (p < 0,05), respectivamente. La estación del año en que ocurrió el parto se asoció significativamente (p < 0,05) con los valores promedios de urea láctea, alcanzando a... |
Tipo: Journal article |
Palavras-chave: Leche; Proteína; Urea; Recuento de células somáticas; Vacas lecheras. |
Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0365-28072006000300005 |
| |
Registros recuperados: 113 | |
|
|
|