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Sample records for plasma urea nitrogen

  1. Correlation between dietary nitrogen, level of plasma urea and urea excretion in urine of buffalo calves

    International Nuclear Information System (INIS)

    Verma, D.N.; Singh, U.B.

    1978-01-01

    Two experiments were conducted with 6 male buffalo calves of Murrah breed, aged 1.5 years, to determine whether blood urea nitrogen and urea excretion in urine were associated with protein intake. The animals were fed different amounts of crude protein in their diet. The levels of urea-N in the blood, excretion of 14 C from urea and urea-N in the urine were estimated. Close relationships were observed between nitrogen intake, blood urea nitrogen and urea excretion in the urine. The observations indicated that blood urea-N and urea excretion in urine could be quantitated with the protein intake. (author)

  2. Plasma urea nitrogen and progesterone concentrations and follicular dynamics in ewes fed proteins of different degradability

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    Gustavo Bianchi Lazarin

    2012-07-01

    Full Text Available The effects of overfeeding with protein of different degradability on body condition, plasma urea nitrogen and progesterone concentrations, ovulation number and follicular dynamics were assessed in Santa Ines ewes. Twelve ewes were assigned to a randomized block design according to body weight and received overfeeding with soybean meal or with corn gluten meal or maintenance diet for 28 days before ovulation and during the next estrous cycle. Blood samples were taken on days 7, 14, 21, and 28 after the beginning of treatments for analysis of plasma urea nitrogen and on days 3, 6, 9, 12, and 15 into the estrous cycle for analysis of plasma urea nitrogen and progesterone. Follicular dynamics was monitored daily by ultrasound during one estrous cycle. Dry matter and crude protein intake, weight gain, plasma urea nitrogen concentration before ovulation, number of ovulations, diameter of the largest follicle of the 1st and of the 2nd waves and the growth rate of the largest follicle of the 1st wave were higher in the ewes that received overfeeding. The growth rate of the largest follicle of the 3rd wave was higher in the ewes fed maintenance diet. The back fat thickness, plasma urea nitrogen before ovulation and progesterone concentrations, diameter of the largest follicle of the 2nd wave and growth rate of the largest follicle of the 3rd wave were higher in ewes that received overfeeding with soybean meal. The growth rate of the largest follicle of the 1st wave was higher in ewes that received overfeeding with corn gluten meal. Overfeeding with protein-rich feeds may increase the ovulation number and with soybean meal, it may be effective in increasing plasma progesterone concentration in ewes.

  3. 21 CFR 862.1770 - Urea nitrogen test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urea nitrogen test system. 862.1770 Section 862....1770 Urea nitrogen test system. (a) Identification. A urea nitrogen test system is a device intended to measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and urine...

  4. Plasma uric acid, creatinine, and urea nitrogen concentrations after whole blood administration via the gastrointestinal tract in domestic pigeons (Columba livia).

    Science.gov (United States)

    Sheldon, Julie; Hoover, John P; Payton, Mark E

    2007-06-01

    To determine if blood administered to pigeons by gavage tube would simulate gastrointestinal hemorrhage in a noncarnivorous avian model, be digested in the gastrointestinal tract, and subsequently alter concentrations of plasma urea nitrogen, creatinine, or uric acid, blood from common peacocks (Pavo cristatus) was administered by gavage tube to 5 healthy domestic pigeons (Columba livia) at doses of 0.5, 1.0, 2.0, 4.0, and 8.0 ml/kg. No significant difference in plasma concentrations of urea nitrogen, creatinine, or uric acid was seen 4-6 hours after gavage. The findings did not support or rule out the presence of gastrointestinal blood in pigeons as a model for hemorrhage in noncarnivorous avian species.

  5. Utilization of urea-nitrogen-15 in ruminants

    International Nuclear Information System (INIS)

    Boda, K.; Varady, J.; Havassy, I.

    1976-01-01

    In Merino sheep a series of experiments were carried out investigating exogenous and endogenous urea utilization. On the experimental sheep with isolated jejunum, rumen and intestine fistula, re-entral intestine cannulae, and after intra-ruminal or intra-intestinal 15 N-urea administration it was found that urea- 15 N takes part in the nitrogen recycling, and is utilized in the nitrogen pool. In experiments with synthetic protein-free diet, low protein diet and high nitrogen diet, after the intravenous administration of 15 N-urea the following findings were made: The results of experiments with synthetic diet, where the only nitrogen source was perorally (for 3-6 months) and then intravenously (for 3 months) administered urea, indicated the ability of ruminants to replace fully the nitrogen in the feed under certain conditions by increased endogenous urea recirculation. The results of the experiments with various nitrogen intakes showed that considerable amounts of urea- 15 N (44-96% from the given dose) were retained. Nitrogen compounds synthetized from blood urea- 15 N were recycled through the alimentary tract. Its secretion predominated in the forestomachs, abomasum and duodenum, and its reabsorption took place in the intestinal tract. From the 15 N incorporated into the nitrogenous substances which passed through the duodenum, 73-84% was reabsorbed. The retained 15 N was incorporated into the microbial and plasma proteins and its amide-N. On the basis of these results it is concluded that in addition to the rumeno-hepatal circulation, the entero-hepatal circulation of nitrogenous substances, including endogenous nitrogen, also plays an important role quantitatively and perhaps qualitatively in the process of re-utilizing the blood urea N for proteosynthesis and synthesis of other N-metabolites in ruminants. The hydrolysis of endogenous urea in the gastro-intestinal tract of ruminants and its utilization is a natural process indispensable for the maintenance of

  6. BUN (Blood Urea Nitrogen): MedlinePlus Lab Test Information

    Science.gov (United States)

    ... https://medlineplus.gov/labtests/bunbloodureanitrogen.html BUN (Blood Urea Nitrogen) To use the sharing features on this ... please enable JavaScript. What is a BUN (Blood Urea Nitrogen) Test? A BUN, or blood urea nitrogen ...

  7. Effect of whole body gamma-irradiation and/or dietary protein deficiency on the levels of plasma non-protein nitrogen and amino acids; plasma and urinary ammonia and urea in desert rodent and albino rats

    International Nuclear Information System (INIS)

    Roushdy, H.M.; El-Husseini, M.; Saleh, F.

    1984-01-01

    The effect of gamma-irradiation exposure on the levels of non-protein nitrogen (N.P.N.) and amino acids in plasma; ammonia and urea in plasma and urine was studied in the desert rodent, Psammomys obesus obesus and albino rats subjected to dietary protein deficiency, N.P.N. and amino acids in plasma were shown to increase by irradiation exposure. The effect of radiation on blood ammonia was less marked, but it caused a significant increase in ammonia excretion in urine. Radiation exposure in albino rats caused a marked increase in urea concentration in plasma of animals fed the high protein diet and irradiated at 780 r. In urine, the tested radiation levels caused an initial increase in urea concentration followed by a subsequent decrease. In psammomys, radiation exposure exerted a little effect on the plasma urea level, whereas significant increase in the daily urea excretion was recorded. It seems that urea level in plasma is more stabilized in psammomys than in albino rats

  8. Environmental factors influencing milk urea nitrogen in South African ...

    African Journals Online (AJOL)

    p2492989

    following fixed effects model, in matrix notation, was used for the ANOVA: .... Estimation of genetic parameters for milk urea nitrogen and its ... urea nitrogen concentration: Heritability and genetic correlations with reproductive performance and.

  9. Influence of milk urea concentration on fractional urea disappearance rate from milk to blood plasma in dairy cows

    NARCIS (Netherlands)

    Spek, J.W.; Dijkstra, J.; Bannink, A.

    2016-01-01

    The relationship between milk urea nitrogen (MUN; mg of N/dL) and urinary N excretion is affected, among others, by diurnal dynamics in MUN, which in turn is largely influenced by feed intake pattern and characteristics of urea transfer from blood plasma to milk and vice versa. This study aimed

  10. Farelo da vagem de algaroba associado a níveis de ureia na alimentação de ovinos: balanço de nitrogênio, N-ureico no plasma e parâmetros ruminais=Mesquite pod meal associated with levels of urea on feeding sheep: nitrogen balance, plasma urea-N and ruminal parameters

    Directory of Open Access Journals (Sweden)

    João Gonsalves Neto

    2012-07-01

    Full Text Available Objetivou-se neste trabalho avaliar os efeitos da inclusão de ureia em dietas contendo farelo da vagem de algaroba sobre o balanço de nitrogênio, N-ureico no plasma e parâmetros ruminais em ovinos. Foram utilizados oito animais, machos castrados, com peso médio de 33,5 kg, distribuídos em dois quadrados latinos 4 x 4. Os tratamentos constituíram da inclusão de níveis de ureia na dieta, sendo: 0; 0,5; 1,0 e 1,5% da MS total. A dieta foi fornecida como dieta total na relação volumoso:concentrado de 40:60 com base na MS total da dieta. Foi realizada a coleta total de urina e fezes e determinada a excreção de nitrogênio. Foi coletado sangue, seguido com a extração do plasma e determinação do N-ureico. Para avaliação do pH e N-amoniacal no líquido ruminal foram utilizados quatro animais fistulados no rúmen. A ingestão de N (31,68 g dia-1 e perdas vias fecal (7,94 g dia-1 e urinária (9,95 g dia-1 não sofreram alterações. As concentrações de N-amoniacal e N-ureico no plasma aumentaram de forma linear. O pH ruminal foi semelhante entre os tratamentos. A inclusão de ureia não influencia o balanço de nitrogênio, porém eleva as concentrações de N-amoniacal no rúmen e N-ureico no plasma podendo influenciar o gasto de energia no organismo.The goal of this study was to evaluate the effects of including urea in diets containing mesquite pod meal on nitrogen balance, plasma urea-N and ruminal parameters. Eight gelded males, with mean weight of 33.5 kg, were divided into two 4 x 4 Latin squares. Treatments consisted of following urea levels in diet: 0, 0.5, 1.0 and 1.5% of total dry matter. The diet was provided as total diet a 40:60 forage: concentrate ratio based on total diet DM. Total urine and feces were collected and nitrogen excretion was determined. Blood was collected, followed by plasma extraction and quantification of urea nitrogen. To evaluate pH and ammonia-N in rumen fluid, four rumen fistulated animals were

  11. Relationship between plasma uridine and urinary urea excretion.

    Science.gov (United States)

    Ka, Tuneyoshi; Inokuchi, Taku; Tamada, Daisuke; Suda, Michio; Tsutsumi, Zenta; Okuda, Chihiro; Yamamoto, Asako; Takahashi, Sumio; Moriwaki, Yuji; Yamamoto, Tetsuya

    2010-03-01

    To investigate whether the concentration of uridine in plasma is related to the urinary excretion of urea, 45 healthy male subjects with normouricemia and normal blood pressure were studied after providing informed consent. Immediately after collection of 24-hour urine, blood samples were drawn after an overnight fast except for water. The contents of ingested foods during the 24-hour urine collection period were described by the subjects and analyzed by a dietician. Simple regression analysis showed that plasma uridine was correlated with the urinary excretions of urea (R = 0.41, P urea. These results suggest that an increase in de novo pyrimidine synthesis leads to an increased concentration of uridine in plasma via nitrogen catabolism in healthy subjects with normouricemia and normal blood pressure. (c) 2010 Elsevier Inc. All rights reserved.

  12. Effects of high ambient temperature on urea-nitrogen recycling in lactating dairy cows.

    Science.gov (United States)

    Obitsu, Taketo; Kamiya, Mitsuru; Kamiya, Yuko; Tanaka, Masahito; Sugino, Toshihisa; Taniguchi, Kohzo

    2011-08-01

    Effects of exposure to hot environment on urea metabolism were studied in lactating Holstein cows. Four cows were fed ad libitum a total mixed ration and housed in a temperature-controlled chamber at constant moderate (18°C) or high (28°C) ambient temperatures in a cross-over design. Urea nitrogen (N) kinetics was measured by determining urea isotopomer in urine after single injection of [(15) N(2) ]urea into the jugular vein. Both dry matter intake and milk yield were decreased under high ambient temperature. Intakes of total N and digestible N were decreased under high ambient temperature but urinary urea-N excretion was increased. The ratio of urea-N production to digestible N was increased, whereas the proportion of gut urea-N entry to urea-N production tended to be decreased under high ambient temperature. Neither return to the ornithine cycle, anabolic use nor fecal excretion of urea-N recycled to the gut was affected by ambient temperature. Under high ambient temperature, renal clearance of plasma urea was not affected but the gut clearance was decreased. Increase of urea-N production and reduction of gut urea-N entry, in relative terms, were associated with increased urinary urea-N excretion of lactating dairy cows in higher thermal environments. 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

  13. Influence of milk urea concentration on fractional urea disappearance rate from milk to blood plasma in dairy cows.

    Science.gov (United States)

    Spek, J W; Dijkstra, J; Bannink, A

    2016-05-01

    The relationship between milk urea nitrogen (MUN; mg of N/dL) and urinary N excretion is affected, among others, by diurnal dynamics in MUN, which in turn is largely influenced by feed intake pattern and characteristics of urea transfer from blood plasma to milk and vice versa. This study aimed to obtain insight in urea transfer characteristics within the mammary gland and from the mammary gland to blood plasma in dairy cows at various concentrations of plasma urea nitrogen (PUN; mg of N/dL) and MUN. Urea transfer from milk to blood plasma and urea transfer within the mammary gland itself was evaluated in a 4×4 Latin square design using 4 lactating multiparous Holstein-Friesian cows (milk production of 39.8±4.70kg/d and 90±3.9 d in milk). Treatments consisted of 4 primed continuous intravenous urea infusions of 0, 5, 10, and 15g of urea/h. Boluses of [(15)N(15)N]urea were injected in cistern milk at 20, 60, and 100 min before the 1700h milking. Milk was collected in portions of approximately 2 L at the 1700h milking. Milk samples were analyzed for urea and enrichment of (15)N-urea. Results from one cow were discarded because of leakage of milk from the teats after injection of boluses of [(15)N(15)N]urea. Increasing urea infusion rate linearly increased PUN from 11.4 (0g of urea/h) to 25.9mg/dL (15g of urea/h) and MUN from 10.3 (0g of urea/h) to 23.5 (15g of urea/h) mg of N/dL. The percentage of injected [(15)N(15)N]urea recovered from milk at the time of injection was not affected by urea infusion rate and varied between 65.1 and 73.0%, indicating that a substantial portion of injected [(15)N(15)N]urea was not accounted for by collected milk. The estimated fractional disappearance rate of (15)N-urea from milk to blood (Kurea; per hour) linearly increased from 0.429 (0g of urea/h) to 0.641 per hour (15g of urea/h). Cistern injected [(15)N(15)N]urea diffused within 20 min after injection toward alveoli milk. Calculations with the average Kurea estimated in this

  14. Environmental factors influencing milk urea nitrogen in South African ...

    African Journals Online (AJOL)

    By knowing the milk urea nitrogen (MUN) content of dairy cows, the efficiency of dietary nitrogen utilization can be improved. The main objectives of this study were to identify and quantify environmental factors affecting MUN in South African Holstein cows. This will enable better interpretation of MUN results by accounting ...

  15. Comparative changes in monthly blood urea nitrogen, total protein ...

    African Journals Online (AJOL)

    The objective of this study was to determine the comparative changes in the monthly blood urea nitrogen (BUN) concentration, total protein (TP) concentration in blood serum and the body condition score of Nguni cows and heifers raised on sweetveld. Twenty-four clinically healthy animals in different parities, namely Parity ...

  16. Effect of nitrogen concentration of urea ammonium nitrate, and ...

    African Journals Online (AJOL)

    Liquid urea ammonium nitrate (UAN) was applied to dryland Pennisetum clandestinum (Kikuyu (Chiov)) and Cynodon hybrid (Coastcross II (L.) (Pers.)) pastures at two levels (207 and 414 kg N/ha/season) and at three concentrations (10, 5; 21 and 42% N) of nitrogen. The degree of leaf scorch increased as both the amount ...

  17. Effects of Controlled-Release Urea on Grain Yield of Spring Maize, Nitrogen Use Efficiency and Nitrogen Balance

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    JI Jing-hong

    2017-03-01

    Full Text Available The effects of mixing controlled-released urea (CRU (release period of resin coated urea is 90 days and urea (U on maize yield, nitrogen use efficiency and nitrogen balance were studied by 4 plot experiments (site:Shuangcheng, Binxian, Harbin and Zhaoyuan in two years (from year 2011 to 2012 to clarify the effect of controlled release urea on spring maize and soil nitrogen balance. Results were as follow:Spring maize yield and nitrogen absorption were increased with the increasing nitrogen fertilizer. Compared with applying urea treatment, applying CRU could increase yield, nitrogen absorption, nitrogen use efficiency, agriculture efficiency of nitrogen and nitrogen contribution rate. Under the same amount of nitrogen (100%, 75%, 50%, compared with 100% U as basic fertilizer treatment, maize yield of 100% CRU treatment increased 391, 427, 291 kg·hm-2, nitrogen use efficiency increased by 5.9%,4.9% and 5.1%, agriculture efficiency of nitrogen increased 2.0, 2.6, 2.6 kg·kg-1, and nitrogen contribution rate increased 2.7%, 3.1% and 2.4%, respectively. The value of maize yield, nitrogen absorption, nitrogen use efficiency and agriculture efficiency of nitrogen between the treatment four (40% urea as basic fertilizer+60% urea as topdressing and treatment five (40% urea plus 60% controlled release urea as basic fertilizer were similar. Apparent profit and loss of nitrogen decreased with the increase of nitrogen nitrogen fertilizer. Nitrogen apparent loss by applying 100% controlled release urea was reduced of 15.0 kg·hm-2 than applying 100% U treatment;Nitrogen apparent loss amount was decreased of 23.9 kg·hm-2 under treatment five. The method of mixing 40% urea and 60% controlled release urea should be applied in maize production in Heilongjiang Province.

  18. Reference Values for Plasma Electrolytes and Urea in Nigerian ...

    African Journals Online (AJOL)

    Reference values for plasma electrolytes and urea have been defined for Nigerian children and adolescents residing in Abeokuta and its environs, a location in southern Nigeria, by estimating plasma sodium, potassium bicarbonate and urea concentrations in a reference population. The study group comprised three ...

  19. Response of maize to reduced urea application combined with compound nitrogen fertilizer synergists

    International Nuclear Information System (INIS)

    Tian Xiuying; WANG Zhengyin

    2006-01-01

    Pot and field experiments were conducted to study the response to application rate of urea labeled with 15 N combined with compound nitrogen fertilizer synergists in the growth, yield, uptake and utilization rate of urea of maize. In pot experiment, the standard urea application rate is 120 mg/perpot; in field experiment, the standard urea application rate is 157.5 kg/hm 2 . Maize with 15 N-urea. The results showed that the growth of maize seedling was obviously promoted with appropriate dosage of compound nitrogen fertilizer synergists (20%-60% of N). The treatments of urea application rate reduced by 5%-15% and added compound nitrogen fertilizer synergists, the growth and nitrogen content of maize were not significant changed, and the total 15 N uptake and nitrogen uptake by maize were the same as CK 2 or increased a little. Nitrogen use efficiency of other treatments increased by 5.6%-7.3% comparing with CK, except the treatment of urea application rate reduced by 30%. The apparent utilization rate of nitrogen was enhanced by 7.7%-17.0%. Under the field condition, maize yield, total uptake, net uptake, physiological rate and agronomic use efficiency of nitrogen were the same as CK or increased. The apparent utilization rate of nitrogen was enhanced by 14.8%-15.2% treated with urea reduced by 5%-15% (7.8-23.7 kg/hm 2 ) and added with compound nitrogen fertilizer synergists. It was not helpful for the growth and nitrogen utilization rate of maize when urea reduced by 30% and combined with compound nitrogen fertilizer synergists. As a result, treated with urea decreased by 15% and combined with appropriate dosage of compound nitrogen fertilizer synergists (20% of urea), the growth and yield of maize had litter effect and higher the uptake and utilization of nitrogen. (authors)

  20. The dogfish shark (Squalus acanthias) increases both hepatic and extrahepatic ornithine urea cycle enzyme activities for nitrogen conservation after feeding.

    Science.gov (United States)

    Kajimura, Makiko; Walsh, Patrick J; Mommsen, Thomas P; Wood, Chris M

    2006-01-01

    Urea not only is utilized as a major osmolyte in marine elasmobranchs but also constitutes their main nitrogenous waste. This study investigated the effect of feeding, and thus elevated nitrogen intake, on nitrogen metabolism in the Pacific spiny dogfish Squalus acanthias. We determined the activities of ornithine urea cycle (O-UC) and related enzymes in liver and nonhepatic tissues. Carbamoyl phosphate synthetase III (the rate-limiting enzyme of the O-UC) activity in muscle is high compared with liver, and the activities in both tissues increased after feeding. The contribution of muscle to urea synthesis in the dogfish body appears to be much larger than that of liver when body mass is considered. Furthermore, enhanced activities of the O-UC and related enzymes (glutamine synthetase, ornithine transcarbamoylase, arginase) were seen after feeding in both liver and muscle and were accompanied by delayed increases in plasma urea, trimethylamine oxide, total free amino acids, alanine, and chloride concentrations, as well as in total osmolality. The O-UC and related enzymes also occurred in the intestine but showed little change after feeding. Feeding did not change the rate of urea excretion, indicating strong N retention after feeding. Ammonia excretion, which constituted only a small percentage of total N excretion, was raised in fed fish, while plasma ammonia did not change, suggesting that excess ammonia in plasma is quickly ushered into synthesis of urea or protein. In conclusion, we suggest that N conservation is a high priority in this elasmobranch and that feeding promotes ureogenesis and growth. Furthermore, exogenous nitrogen from food is converted into urea not only by the liver but also by the muscle and to a small extent by the intestine.

  1. Ammonia volatilization from surface-applied nitrogen solution of urea and ammonium nitrate

    International Nuclear Information System (INIS)

    Trivellin, Paulo Cezar Ocheuze; Stefanutti, Ronaldo; Lima Filho, Oscar Fontvo de; Tziboy, Edgar Alfredo Tzi; Oliveira Junior, Jovo Alberto de; Bendassolli, Jose Albertino

    1996-08-01

    The urea is one of the fertilizers more utilized in modern agriculture. One of the problems in the urea utilization is the ammonium volatilization, resulting in low utilization of N-fertilizers by the plants.The objective of this study it was to evaluate and to compare in laboratories conditions , utilizing the 15 N technic the soil's ammonium lost by volatilization associated a superficial application of nitrogen corresponding doses like urea solution and urea and ammonium nitrates solution

  2. Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

    International Nuclear Information System (INIS)

    Wu Gang; Zhang Qinzheng; Ye Qingfu; Zhu Zhujun; Xi Haifu; He Zhenli

    1998-01-01

    The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using 15 N tracer method. When urea and ryegrass were applied alone or in combination, the percentage of N uptaken by ryegrass for labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of 200 mgN·kg -1 and 100 mgN·kg -1 , respectively; combining application of ryegrass and urea reduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant, but the percentage of N residue in soil increased for urea and decreased for ryegrass; when urea and ryegrass were applied alone, the percentage of N residue in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%, and much more ryegrass N was incorporated into humus than urea N

  3. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion

    Science.gov (United States)

    Mitch, William E.; Sands, Jeff M.

    2015-01-01

    Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. PMID:25078422

  4. Protein Losses and Urea Nitrogen Underestimate Total Nitrogen Losses in Peritoneal Dialysis and Hemodialysis Patients.

    Science.gov (United States)

    Salame, Clara; Eaton, Simon; Grimble, George; Davenport, Andrew

    2018-04-28

    Muscle wasting is associated with increased mortality and is commonly reported in dialysis patients. Hemodialysis (HD) and peritoneal dialysis (PD) treatments lead to protein losses in effluent dialysate. We wished to determine whether changes in current dialysis practice had increased therapy-associated nitrogen losses. Cross-sectional cohort study. Measurement of total protein, urea and total nitrogen in effluent dialysate from 24-hour collections from PD patients, and during haemodiafiltration (HDF) and haemodialysis (HD) sessions. One hundred eight adult dialysis patients. Peritoneal dialysis, high-flux haemodialysis and haemodiafiltration. Total nitrogen and protein losses. Dialysate protein losses were measured in 68 PD and 40 HD patients. Sessional losses of urea (13.9 [9.2-21.1] vs. 4.8 [2.8-7.8] g); protein (8.6 [7.2-11.1] vs. 6.7 [3.9-11.1] g); and nitrogen (11.5 [8.7-17.7] vs. 4.9 [2.6-9.5] g) were all greater for HD than PD, P losses were lower with HD 25.9 (21.5-33.4) versus 46.6 (27-77.6) g/week, but nitrogen losses were similar. We found no difference between high-flux HD and HDF: urea (13.5 [8.8-20.6] vs. 15.3 [10.5-25.5] g); protein (8.8 [7.3-12.2] vs. 7.6 [5.8-9.0] g); and total nitrogen (11.6 [8.3-17.3] vs. 10.8 [8.9-22.5] g). Urea nitrogen (UN) only accounted for 45.1 (38.3-51.0)% PD and 63.0 (55.3-62.4)% HD of total nitrogen losses. Although sessional losses of protein and UN were greater with HD, weekly losses were similar between modalities. We found no differences between HD and HDF. However, total nitrogen losses were much greater than the combination of protein and UN, suggesting greater nutritional losses with dialysis than previously reported. Copyright © 2018 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  5. Effect of dietary protein sources of on blood or milk urea nitrogen of native cows

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, N R; Huque, K S; Asaduzzaman, M. [Animal Production Research Division, Bangladesh Livestock Research Institute, Savar, Dhaka (Bangladesh)], E-mail: nathusarker@yahoo.com

    2009-07-01

    When feed protein metabolism in ruminants produces urea in the liver and recycles or blood urea (BUN) filters into milk urea nitrogen (MUN), an indicator of protein status in diets or feeding urea as one of the non-protein nitrogen sources for ruminants is scientifically acceptable throughout the world; a section of environmentalists, policy makers or even professionals often raise question of residual effects in milk and/or meat of fattening and/or dairy cattle fed with diets containing urea. Keeping their views in consideration, a feeding trial on 30 Pabna milking cows of 2 to 4 parities dividing equally into 5 groups was arranged to determine the effect of feeding of different sources of protein on BUN and MUN, and milk yield or protein content. To achieve the objectives, a group of cows was fed a diet of rice straw and concentrate as the control (T{sub 0}), two out of the rests was fed either with urea-molasses straw (UMS) (T{sub 1}) or Matikalai (Vigna mungo) hay ( T{sub 2}) as sources of basal roughage. The rest two groups of cows were fed the control diet replacing % of feed protein by the amount of urea and molasses fed to UMS group. The amount of urea and molasses was fed daily either in two meals (T{sub 3}) or fed to cows mixing with other concentrate feed (T{sub 4}). In addition, a concentrate mixture containing 45 % wheat bran, 24% Khesari bran, 12% Til oil cake, 12% soybean meal, 4% fishmeal, 2.0% oyster-shell, 0.5% DCP and 0.5% common salt, was supplied twice daily. Having adjusted the cows with the diets for 20 d, a 20 d feeding trial was conducted, when feed intake and samples of blood and milk were collected. Milk samples were collected from individual cow after feeding the experimental diets in the morning and evening milking. Samples were collected from milk bucket after complete milking and mixing thoroughly. Samples were analyzed for milk urea content (MUN) using a Colorimetric p-dimethylaminobenzaldehyde (DMAB) method as described by Bector et

  6. Farelo da vagem de algaroba associado a níveis de ureia na alimentação de ovinos: balanço de nitrogênio, N-ureico no plasma e parâmetros ruminais - doi: 10.4025/actascianimsci.v34i3.12759 Mesquite pod meal associated with levels of urea on feeding sheep: nitrogen balance, plasma urea-N and ruminal parameters - doi: 10.4025/actascianimsci.v34i3.12759

    Directory of Open Access Journals (Sweden)

    João Gonsalves Neto

    2012-05-01

    Full Text Available Objetivou-se neste trabalho avaliar os efeitos da inclusão de ureia em dietas contendo farelo da vagem de algaroba sobre o balanço de nitrogênio, N-uréico no plasma e parâmetros ruminais em ovinos. Foram utilizados oito animais, machos castrados, com peso médio de 33,5 kg, distribuídos em dois quadrados latinos 4 x 4. Os tratamentos constituíram da inclusão de níveis de ureia na dieta, sendo: 0; 0,5; 1,0 e 1,5% da MS total. A dieta foi fornecida como dieta total na relação volumoso:concentrado de 40:60 com base na MS total da dieta. Foi realizada a coleta total de urina e fezes e determinada a excreção de nitrogênio. Foi coletado sangue, seguido com a extração do plasma e determinação do N-uréico. Para avaliação do pH e N-amoniacal no líquido ruminal foram utilizados quatro animais fistulados no rúmen. A ingestão de N (31,68 g/dia e perdas vias fecal (7,94 g/dia e urinária (9,95 g/dia não sofreram alteração. As concentrações de N-amoniacal e N-uréico no plasma aumentaram de forma linear. O pH ruminal foi semelhante entre os tratamentos. A inclusão de uréia não influencia o balanço de nitrogênio, porém eleva as concentrações de N-amoniacal no rúmen e N-uréico no plasma podendo influenciar o gasto de energia no organismo.The goal of this study was to evaluate the effects of including urea in diets containing mesquite pod meal on nitrogen balance, plasma urea-N and ruminal parameters. Eight gelded males, with mean weight of 33.5 kg, were divided into two 4 x 4 Latin squares. Treatments consisted of following urea levels in diet: 0, 0.5, 1.0 and 1.5% of total dry matter. The diet was provided as total diet a 40:60 forage: concentrate ratio based on total diet DM. Total urine and feces were collected and nitrogen excretion was determined. Blood was collected, followed by plasma extraction and quantification of urea nitrogen. To evaluate pH and ammonia-N in rumen fluid, four rumen fistulated animals were used

  7. Increases In Plasma Urea And Creatinine In Experimental ...

    African Journals Online (AJOL)

    Alterations in both plasma urea and creatinine levels were monitored over a period of twenty eight (28) days in experimentally infected rabbits. A total of 15 animals were randomly divided into three groups of n=5. The groups were control (group I), infected and treated (group II) and infected but untreated (group III) ...

  8. The Chinese soft-shelled turtle, Pelodiscus sinensis, decreases nitrogenous excretion, reduces urea synthesis and suppresses ammonia production during emersion.

    Science.gov (United States)

    Ip, Yuen K; Lee, Serene M L; Wong, Wai P; Chew, Shit F

    2013-05-01

    The objective of this study was to examine the effects of 6 days of emersion on nitrogen metabolism and excretion in the Chinese soft-shelled turtle, Pelodiscus sinensis. Despite having a soft shell with a cutaneous surface that is known to be water permeable, P. sinensis lost only ~2% of body mass and was able to maintain its hematocrit and plasma osmolality, [Na(+)] and [Cl(-)] during 6 days of emersion. During emersion, it ameliorated water loss by reducing urine output, which led to a reduction (by 29-76%) in ammonia excretion. In comparison, there was a more prominent reduction (by 82-99%) in urea excretion during emersion due to a lack of water to flush the buccopharyngeal epithelium, which is known to be the major route of urea excretion. Consequently, emersion resulted in an apparent shift from ureotely to ammonotely in P. sinensis. Although urea concentration increased in several tissues, the excess urea accumulated could only account for 13-22% of the deficit in urea excretion. Hence, it can be concluded that a decrease (~80%) in urea synthesis occurred in P. sinensis during the 6 days of emersion. Indeed, emersion led to significant decreases in the activity of some ornithine-urea cycle enzymes (argininosuccinate synthetase/argininosuccinate lyase and arginase) from the liver of P. sinensis. As a decrease in urea synthesis occurred without the accumulation of ammonia and total free amino acids, it can be deduced that ammonia production through amino acid catabolism was suppressed with a proportional reduction in proteolysis in P. sinensis during emersion. Indeed, calculated results revealed that there could be a prominent decrease (~88%) in ammonia production in turtles after 6 days of emersion. In summary, despite being ureogenic and ureotelic in water, P. sinensis adopted a reduction in ammonia production, instead of increased urea synthesis, as the major strategy to ameliorate ammonia toxicity and problems associated with dehydration during

  9. Determing the fate of selected antibiotics during nitrogen recovery via urea-formaldehdye synthesis

    OpenAIRE

    Kashobwe, Lackson

    2016-01-01

    The work presented here focused on the determination of fate of four selected antibiot-ics: enrofloaxicin, oxytetracyline, sulfamethoxazole and tylosin during nitrogen recovery from source separated urine via urea formaldehyde synthesis. The experimental pH was at 2 and temperature at 25°C throughout the chemical reaction, preventing urea hydroly-sis. Five main chemical reactions: aqueous + antibiotics, Urine + formaldehyde + antibi-otics (UF synthesis experiment), urea-formaldehyde polymer +...

  10. Fractionation of nitrogen and carbon isotopes by means of urea chromatography

    International Nuclear Information System (INIS)

    Hirschberg, K.; Krumbiegel, P.; Faust, H.

    1981-01-01

    Between aqueous urea solutions and strongly acid cation exchange resins of the polystyrene-sulfoacid type a solid-liquid-phase distribution equilibrium develops with an isotope effect of nitrogen and carbon in urea. The [ 13 C, 15 N] urea molecules are preferably bound to the exchanger matrix. The elementary separation factors for 15 N and 13 C enrichment have been determined to be 1.00 per cent. Column chromatographic separation with the aid of Dowex 50 WX8 renders the preparation of double-labelled urea feasible. (author)

  11. Production of ammonia from plasma-catalytic decomposition of urea: Effects of carrier gas composition.

    Science.gov (United States)

    Fan, Xing; Li, Jian; Qiu, Danqi; Zhu, Tianle

    2018-04-01

    Effects of carrier gas composition (N 2 /air) on NH 3 production, energy efficiency regarding NH 3 production and byproducts formation from plasma-catalytic decomposition of urea were systematically investigated using an Al 2 O 3 -packed dielectric barrier discharge (DBD) reactor at room temperature. Results show that the presence of O 2 in the carrier gas accelerates the conversion of urea but leads to less generation of NH 3 . The final yield of NH 3 in the gas phase decreased from 70.5%, 78.7%, 66.6% and 67.2% to 54.1%, 51.7%, 49.6% and 53.4% for applied voltages of 17, 19, 21 and 23kV, respectively when air was used as the carrier gas instead of N 2 . From the viewpoint of energy savings, however, air carrier gas is better than N 2 due to reduced energy consumption and increased energy efficiency for decomposition of a fixed amount of urea. Carrier gas composition has little influence on the major decomposition pathways of urea under the synergetic effects of plasma and Al 2 O 3 catalyst to give NH 3 and CO 2 as the main products. Compared to a small amount of N 2 O formed with N 2 as the carrier gas, however, more byproducts including N 2 O and NO 2 in the gas phase and NH 4 NO 3 in solid deposits were produced with air as the carrier gas, probably due to the unproductive consumption of NH 3 , the possible intermediate HNCO and even urea by the abundant active oxygen species and nitrogen oxides generated in air-DBD plasma. Copyright © 2017. Published by Elsevier B.V.

  12. Nitrogen management and nitrification inhibitor effects on nitrogen-15 urea: 2. Nitrogen leaching and balance

    International Nuclear Information System (INIS)

    Walters, D.T.; Malzer, G.L.

    1990-01-01

    Nitrification inhibitors (NI) may reduce N leaching losses, and should have the greatest effect on sandy soils where leaching potential is high. This study used 27 lysimeters to evaluate the effect of a NI, nitrapyrin [2-chloro-6(trichloromethyl) pyridine], on soil water percolation (SWP) and N leaching losses from an irrigated sandy loam soil (Typic Hapludoll) planted with corn (Zea mays L.), and monitor the fate of a single application of 15 N-enriched urea over a multiyear period. Urea was applied at 90 and 180 kg N ha -1 yr -1 for a 3-yr period, with and without NI, and with and without incorporation. Urea + NI reduced SWP between planting and silking in 2 out of 3 yr when growing degree days (GDD) were high. After silking, SWP was reduced when urea + NI was incorporated and leaching load was high. A twofold increase in N rate resulted in an average of 3.4 times more N leached over 3 yr. The NI influenced time of N loss but not total N loss. Leaching losses of fertilizer-derived N (FDN) were delayed 25 to 50d when urea + NI were incorporated. The leaching load required to reach the maximum rate of FDN loss was higher with urea + NI. Leaching losses of fertilizer N were three times greater when determined by the difference method than by isotope-ratio analysis. Differing results with these two calculations are attributed to isotope dilution with indigenous soil N as a result of microbial activity. Nitrification inhibitors may reduce the potential for nonpoint-source pollution by delaying NO 3 leaching, but will be most effective if coupled with proper N rates and conservative irrigation water management

  13. Ammonia Nitrogen Added to Diets Deficient in Dispensable Amino Acid Nitrogen Is Poorly Utilized for Urea Production in Growing Pigs.

    Science.gov (United States)

    Mansilla, Wilfredo D; Silva, Kayla E; Zhu, Cuilan L; Nyachoti, Charles M; Htoo, John K; Cant, John P; de Lange, Cornelis Fm

    2017-12-01

    Background: Including ammonia in low-crude protein (CP) diets deficient in dispensable amino acid (DAAs) increases nitrogen retention in growing pigs. Objective: We investigated the absorption and metabolism of dietary ammonia nitrogen in the portal-drained viscera (PDV) and liver of pigs fed a diet deficient in DAA nitrogen. Methods: Eight pigs with an initial mean ± SD body weight (BW) of 26.5 ± 1.4 kg were surgically fitted with 4 catheters each (portal, hepatic and mesenteric veins, and carotid artery). The pigs were fed (2.8 × 191 kcal/kg BW 0.60 ), for 7 d and every 8 h, a diet deficient in DAA nitrogen supplemented with increasing amounts of ammonia nitrogen (CP: 7.76%, 9.27%, and 10.77%; indispensable amino acid nitrogen:total nitrogen ratio: 0.71, 0.59, and 0.50 for control and low- and high-ammonia diets, respectively). The treatment sequence was based on a Latin square design with 3 consecutive periods. On the last day of each period, blood flows in the portal and hepatic veins were determined with a continuous infusion of ρ-amino hippuric acid into the mesenteric vein. Serial blood samples were taken to determine ammonia and urea nitrogen concentration. Net balances of ammonia and urea nitrogen were calculated for the PDV and liver. Results: Cumulative (8 h) ammonia nitrogen appearance in the portal vein increased ( P ≤ 0.05) with ammonia intake (433, 958, and 1629 ± 60 mg ammonia nitrogen/meal for control and low- and high-ammonia diets, respectively). The cumulative hepatic uptake of ammonia nitrogen increased ( P ≤ 0.05) with ammonia nitrogen supply. The cumulative urea nitrogen appearance in the hepatic vein tended to increase ( P ≤ 0.10) only in high-ammonia treatment (-92.5, -59.4, and 209.7 ± 92 mg urea nitrogen/meal for control and low- and high-ammonia diets, respectively) and, relative to the control diet, represented -6.0% and 11% of ammonia nitrogen intake. Conclusion: Dietary ammonia nitrogen is poorly utilized for urea

  14. Nitrogen mineralization and volatilization from controlled release urea fertilizers in selected malaysian soils

    International Nuclear Information System (INIS)

    Singh, K.J.K.A.; Yusop, M.K.; Oad, F.C.

    2017-01-01

    Controlled release urea fertilizers are usually used for extended duration in supplying nitrogen. The rate of urea hydrolysis could be efficiently minimized through these fertilizers. Various controlled released fertilizers i.e Uber-10 (30%N), Meister-20 (40%N), Meister-27 (40%N), Humate Coated Urea (45%N), Duration Polymer Coated Urea Type-V (43%N), Gold-N-Sulfur Coated Urea (41%N) and common urea (46%N) were applied to inland soil series of Malaysia. The soil series investigated were: Serdang (Typic Paleudult), Munchong (Typic Hapludox), Segamat (Typic Hapludox), Selangor (Typic Tropaquept), Rengam (Typic Kandiudult) and Holyrood (Typic Kandiudult). The maximum release of ammonium (NH/sub 4/-N) was noted in Gold-N-Sulfur Coated Urea, Humate Coated Urea and common Urea over 8 weeks of incubation. However, the release of NH4-N under the influence of Duration Type-V and Uber-10 took 2nd place. The Meister-20 and Meister-27 had minimum release of NH4-N. Munchong series was efficient in releasing higher NH4-N compared to rest of soils during 8th week of incubation due to higher soil total carbon, low /sub 4/-N and total nitrogen. Ammonia (NH/sub 3/-N) loss progressively increased with unit increase in incubation week and was higher during 6th week of fertilizer application. The higher loss of NH3-N was found in common Urea. However, Meister-20, Meister-27, Duration Polymer Coated Urea Type-V and Uber-10 had lower loss of NH/sub 3/-N due to slow release property and this character could be beneficial for supplying nutrients to next season crop. (author)

  15. Urea as a Nitrogen Source in a Black Tiger Shrimp (Penaeus monodon) Closed Culture System

    OpenAIRE

    Supannee SUWANPAKDEE; Sataporn DIREKBUSARAKOM; Piyapong CHOTIPUNTU; Putth SONGSANGJINDA

    2010-01-01

    Urea [(NH2)2CO] is an organic compound that serves an important role in the metabolism of nitrogen-containing compound by animals. Urea is widely used in aquaculture systems. This study investigated the effects of urea on growth of Penaeus monodon. Shrimp were reared in 500 l fiber tanks. There was no exchange of water throughout the experiment. Shrimp with an average body weight of 10.99 ± 0.19 g were stocked at a density of 32 shrimp/m2 in 20 ppt diluted seawater and fed with 38 % protein d...

  16. Slow release coating remedy for nitrogen loss from conventional urea: a review.

    Science.gov (United States)

    Naz, Muhammad Yasin; Sulaiman, Shaharin Anwar

    2016-03-10

    Developing countries are consuming major part of the global urea production with an anticipated nitrogen use efficiency of 20 to 35%. The release of excess nitrogen in the soil is not only detrimental to the environment but also lessens the efficiency of the conventional urea. The urea performance can be enhanced by encapsulating it with slow release coating materials and synchronizing the nutrients' release with the plant up-taking. However, the present cost of most of the coated fertilizers is considerably higher than the conventional fertilizers. The high cost factor prevents their widespread use in mainstream agriculture. This paper documents a review of literature related to the global urea market, issues pertaining to the conventional urea use, natural and synthetic materials for slow release urea and fluidized bed spray coating process. The aim of the current review is to develop technical understanding of the conventional and non-conventional coating materials and associated spray coating mechanism for slow release urea production. The study also investigated the potential of starch as the coating material in relation to the coatings tested previously for controlled release fertilizers. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Intake, digestion and nitrogen balance of diets blended with urea ...

    African Journals Online (AJOL)

    Owner

    The diet blended with 3% urea treated cowpea husk gave the highest dry matter intake, growth rate and .... total collection of faeces and urine during the last five days of the trial. .... tissue synthesis of non-essential amino acids from absorbed ...

  18. Differences in nitrogen and urea metabolism between goats bred for ...

    African Journals Online (AJOL)

    glacial acetic acid and dried over H2S04 and soda lime to remove radioactivity .... by factors such as rumen ammonia concentration, volatile fatty acid production ... breed differences observed in this study, but the fact that urea excretion rate in ...

  19. Altered Nitrogen Balance and Decreased Urea Excretion in Male Rats Fed Cafeteria Diet Are Related to Arginine Availability

    Directory of Open Access Journals (Sweden)

    David Sabater

    2014-01-01

    rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

  20. Nitrogen uptake and balance of the fertilizers urea, urea with urease inhibitor, and ammonium nitrate applied to spring wheat at stem elongation growth stage

    International Nuclear Information System (INIS)

    Matzel, W.; Lippold, H.; Heber, R.

    1979-01-01

    The use of urea containing 1% of diamido phosphoric acid phenyl ester, which is a urease inhibitor, for the top dressing of spring wheat on light soil allows the loss of nitrogen due to volatilization of ammonia from urea to be prevented. The urease inhibitor has no effect whatsoever upon the uptake of urea nitrogen by spring wheat. Even in those cases where the volatilization of ammonia is prevented, plants will take up 5 to 6% less nitrogen from urea than from ammonium nitrate. This is due primarily to the higher degree of immobilization of urea nitrogen in the soil. The volatilization of ammonia from urea applied to the surface of the soil was in the region of 25% when the soil surface was moist and 10% when the soil surface was dry, the percentages given above being related to the amount of fertilizer nitrogen applied to the soil. The plant uptake of fertilizer nitrogen applied as a second dose at stem elongation will be complete after two to three weeks or after six weeks under favourable or unfavourable conditions, respectively. Proceeding immediately after application of the fertilizer nitrogen are the processes resulting in both loss of nitrogen and its immobilization. The proportion of absorbed fertilizer nitrogen recovered in the grain will be the greater the later the nitrogen is incorporated into the plant. The use in pot experiments of labelled nitrogen fertilizers enables statistically significant differences in effects to be determined even in those cases in which the differences are only relatively small in degree. (author)

  1. A study of the effects of oral contraceptives on plasma urea of Wistar ...

    African Journals Online (AJOL)

    Oral contraceptives such as Microgynon a combined pill (0.15mg levonorgestrel and 0.03mg ethinylestradiol) and Primolut -N a mini pill (5mg norethisterone) were investigated for their in-vivo effects on wistar albino rat rattus rattus plasma urea levels. Test results showed that the drugs had a lowering effect on plasma urea ...

  2. The fIXationof nitrogen in urea ammoniated wheat straw by means ...

    African Journals Online (AJOL)

    The fixation of nitrogen in urea ammoniated wheat straw by means of different acids was investigated in two laboratory trials and in a voluntary-intake trial with adult SA Mutton Merino wethers. Results from the laboratory trials showed hydrochloric and sulphuric acid to be superior to phosphoric and acetic acid as fixation ...

  3. Comparison of ammonium sulfate and urea as nitrogen sources in rice production

    International Nuclear Information System (INIS)

    Bufogle, A. Jr.; Bollich, P.K.; Kovar, J.L.; Lindau, C.W.; Macchiavellid, R.E.

    1998-01-01

    Wetland rice agriculture is the major anthropogenic source of methane, an important greenhouse gas. Methane emissions are less when ammonium sulfate (AS) rather than urea is the nitrogen (N) source. However, an agronomic advantage of AS over urea has not been established. The objectives of this study were: (i) to compare the effectiveness of AS, urea, and urea plus elemental sulfur (S) as sources of N in flooded rice culture, (ii) to compare fertilizer recovery of each source of N from application at preflood (PF) and panicle initiation (PI), and (iii) to determine if there is a response to S by rice grown on a soil with a less than optimum level of available S. 'Cypress' rice was drill-seeded in a Crowley silt loam soil (fine, montmorillonitic, thermic Typic Albaqualf) of 7.25 to 10.75 mg S kg-1. Ammonium sulfate, urea, or urea plus S was applied in split applications of 101 kg N ha-1 PF and 50 kg N ha-1 PI. Microplots with retainers and 15N-labeled N were used. Unlabeled N was used in field plots. Microplots were harvested at 50% heading, while field plots were harvested at maturity. Dry matter and total N accumulation at 50% heading and at maturity were similar regardless of N source. Grain dry matter yields were 8.54, 8.47, and 8.79 Mg ha-1 for AS, urea, and urea plus S treatments, respectively. Greater N recovery was generally found from N application at PI than at PF, but this was not reflected by an increase in grain yield. No response to S was detected, although grain yields were slightly higher when S-containing fertilizers were used. Ammonium sulfate and urea were equally effective for flooded rice production in Louisiana

  4. Differences in nitrogen and urea metabolism between goats bred for ...

    African Journals Online (AJOL)

    This experiment was conducted to determine whether selection for fleece weight is accompanied by changes in the efficiency of nitrogen utilization, using Angora and Boer goats as models of animals bred for fleece or meat production respectively. A diet, containing a protein: energy ratio of 12 g CP/ MJ ME, was fed at ...

  5. Limiting the testing of urea: Urea along with every plasma creatinine test?

    Science.gov (United States)

    Zhang, Gao-Ming; Guo, Xu-Xiao; Zhang, Guo-Ming

    2017-09-01

    We found that it is not necessary to simultaneously detect both creatinine (CREA) and urea until the concentration of CREA is lower than the certain level. To reduce urea testing, we suggest measuring urea only when CREA or estimated glomerular filtration rate (eGFR) exceeds a predetermined limit. CREA and urea data were analyzed consisting of almost all of people age above 65 years old check-up (n=95441) in Shuyang countryside, and inpatients (n=101631), outpatients (n=18474) and Routine Health Check-up (n=20509) in Shuyang People's Hospital. The proportions of elevated urea were derived. The data used in this study was generated from people more than 13 years old in both outpatients and inpatients. When the limits for initiating urea testing were used at 85 μmol/L CREA and 120 mL/min/1.73 m 2 eGFR, the percentage of unnecessary urea test are 94.5% and 64.7% (elderly health check-up), 67.9% and 84.5% (outpatients), 88.5% and 73.2% (inpatients), 92.2% and 81.7% (routine health check-up). The missing rate of urea are 1%, 2.5%, 4.6% and 9.2%, 0.1%, 0.4%, 0.9% and 1.8%, 0.4%, 0.8%, 1.4%, and 2.5%, 0.05%, 0.1%, 1.1%, and 0.8% of ureas exceeding 9.28 mmol/L and 8.3 mmol/L in above each group, respectively. If the CREA≤85 μmol/L or eGFR≥90 mL/min/1.73 m 2 , there is 97.5% urea urea missed is 2.5%. We suggest that the initiating urea testing should be based on the upper limit of Reference Intervals serum CREA of females or a 120 mL/min/1.73 m 2 eGFR limit. Conservatively, the urea testing would be reduced by 65% at least. © 2017 Wiley Periodicals, Inc.

  6. Effect of two doses of urea foliar application on leaves and grape nitrogen composition during two vintages.

    Science.gov (United States)

    Pérez-Álvarez, Eva P; Garde-Cerdán, Teresa; García-Escudero, Enrique; Martínez-Vidaurre, José María

    2017-06-01

    Nitrogen affects grapevine growth and also yeast metabolism, which have a direct influence on fermentation kinetics and the formation of different volatile compounds. Throughout the grapevine cycle, soil nitrogen availability and grape nitrogen composition can vary because of different factors. Nitrogen foliar applications can contribute toward enhancing grapevine nitrogen status and minimize the problem of leaching that traditional nitrogen-soil applications can provoke. The present study aimed to evaluate the influence of urea foliar applications on grapevine nitrogen status and grape amino acid content. Accordingly, two different doses of urea were applied over the leaves of a 'Tempranillo' vineyard. The highest urea doses affected nitrogen content on blade leaf tissues after veraison. Must amino acid profiles were modified by urea application and some of the compounds increased their concentrations. The effect of year on the increase of must total amino acid concentrations was more important than the effect of the doses applied. Urea foliar applications can be an interesting tool for decreasing grapevine nitrogen deficiencies. This method of nitrogen implementation in the vineyard could avoid sluggish fermentation problems during winemaking, enhance must nitrogen composition, and contribute to improving wine quality. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. Coupled effects of light and nitrogen source on the urea cycle and nitrogen metabolism over a diel cycle in the marine diatom Thalassiosira pseudonana.

    Science.gov (United States)

    Bender, Sara J; Parker, Micaela S; Armbrust, E Virginia

    2012-03-01

    Diatoms are photoautotrophic organisms capable of growing on a variety of inorganic and organic nitrogen sources. Discovery of a complete urea cycle in diatoms was surprising, as this pathway commonly functions in heterotrophic organisms to rid cells of waste nitrogen. To determine how the urea cycle is integrated into cellular nitrogen metabolism and energy management, the centric diatom Thalassiosira pseudonana was maintained in semi-continuous batch cultures on nitrate, ammonium, or urea as the sole nitrogen source, under a 16: 8 light: dark cycle and at light intensities that were low, saturating, or high for growth. Steady-state transcript levels were determined for genes encoding enzymes linked to the urea cycle, urea hydrolysis, glutamine synthesis, pyrimidine synthesis, photorespiration, and energy storage. Transcript abundances were significantly affected by nitrogen source, light intensity and a diel cycle. The impact of N source on differential transcript accumulation was most apparent under the highest light intensity. Models of cellular metabolism under high light were developed based on changes in transcript abundance and predicted enzyme localizations. We hypothesize that the urea cycle is integrated into nitrogen metabolism through its connection to glutamine and in the eventual production of urea. These findings have important implications for nitrogen flow in the cell over diel cycles at surface ocean irradiances. Copyright © 2011 Elsevier GmbH. All rights reserved.

  8. Effects of bentonite on plasma urea and creatinine of wistar albino rats.

    African Journals Online (AJOL)

    The in vivo effect of Nigerian calcium bentonite clay on wistar albino rat plasma urea and creatinine levels were investigated. The rats were fed for a period of four weeks with varying concentrations of the bentonite clay, and the urea and creatinine levels determined using spectrophotometric methods. Test results showed ...

  9. Oxidation of urea-derived nitrogen by thaumarchaeota-dominated marine nitrifying communities.

    Science.gov (United States)

    Tolar, Bradley B; Wallsgrove, Natalie J; Popp, Brian N; Hollibaugh, James T

    2017-12-01

    Urea nitrogen has been proposed to contribute significantly to nitrification by marine thaumarchaeotes. These inferences are based on distributions of thaumarchaeote urease genes rather than activity measurements. We found that ammonia oxidation rates were always higher than oxidation rates of urea-derived N in samples from coastal Georgia, USA (means ± SEM: 382 ± 35 versus 73 ± 24 nmol L -1  d -1 , Mann-Whitney U-test p  0.05). Urea-derived N was relatively more important in samples from Antarctic continental shelf waters, though the difference was not statistically significant (19.4 ± 4.8 versus 12.0 ± 2.7 nmol L -1  d -1 , p > 0.05). We found only weak correlations between oxidation rates of urea-derived N and the abundance or transcription of putative Thaumarchaeota ureC genes. Dependence on urea-derived N does not appear to be directly related to pH or ammonium concentrations. Competition experiments and release of 15 NH 3 suggest that urea is hydrolyzed to ammonia intracellularly, then a portion is lost to the dissolved pool. The contribution of urea-derived N to nitrification appears to be minor in temperate coastal waters, but may represent a significant portion of the nitrification flux in Antarctic coastal waters. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Effect of nitrogen supplementation on urea kinetics and microbial use of recycled urea in steers consuming corn-based diets.

    Science.gov (United States)

    Brake, D W; Titgemeyer, E C; Jones, M L; Anderson, D E

    2010-08-01

    We studied the effects of supplementing N as distillers dried grains with solubles (DDGS) or urea to steers consuming corn-based diets. Six ruminally and duodenally cannulated steers (244 kg) were used in 2 concurrent 3 x 3 Latin squares and fed 1 of 3 corn-based diets: control (10.2% CP), urea (13.3% CP), or DDGS (14.9% CP). Periods were 14 d, with 9 d for adaptation and 5 d for collection of urine and feces. Urinary (15)N(15)N-urea enrichments, resulting from venous infusions of (15)N(15)N-urea, were used to measure urea kinetics. Dry matter intake (6.0 kg/d) was not affected by treatment, but N intake differed (99, 151, and 123 g/d for the control, DDGS, and urea treatments, respectively). Urea-N synthesis tended to be greater (P = 0.09) for DDGS (118 g/d) than for the control treatment (52 g/d), with the urea treatment (86 g/d) being intermediate. Urea-N excreted in the urine was greater (P urea treatments (29 g/d) than for the control treatment (13 g/d). Gastrointestinal entry of urea-N was not statistically different among treatments (P = 0.25), but was numerically greatest for DDGS (83 g/d), intermediate for urea (57 g/d), and least for the control (39 g/d). The amount of urea-N returned to the ornithine cycle tended to be greater (P = 0.09) for the DDGS treatment (47 g/d) than for the urea (27 g/d) or control treatment (16 g/d). The fraction of recycled urea-N that was apparently used for anabolism tended (P = 0.14) to be greater for the control treatment (0.56) than for the DDGS treatment (0.31), with the urea treatment (0.45) being intermediate, but no differences were observed among treatments in the amount of urea-N used for anabolism (P = 0.66). Urea kinetics in cattle fed grain-based diets were largely related to the amount of N consumed. The percentage of urea production that was captured by ruminal bacteria was greater (P urea treatment (22%), but the percentage of duodenal microbial N flow that was derived from recycled urea-N tended (P = 0.10) to

  11. The discharge characteristics in nitrogen helicon plasma

    Science.gov (United States)

    Zhao, Gao; Wang, Huihui; Si, Xinlu; Ouyang, Jiting; Chen, Qiang; Tan, Chang

    2017-12-01

    Discharge characteristics of helicon plasma in nitrogen and argon-nitrogen mixtures were investigated experimentally by using a Langmuir probe, a B-dot probe, and an optical emission spectrum. Helicon wave discharge is confirmed by the changes of electron density and electromagnetic signal amplitude with the increasing RF power, which shows three discharge stages in nitrogen, corresponding to E-mode, H-mode, and W-mode discharges in helicon plasma, respectively. Discharge images in the radial cross section at different discharge modes through an intensified charge coupled device (ICCD) show a rapid increase in luminous intensity along with the RF power. When the nitrogen discharge is in the W-mode, the images show that the strongest luminance locates near the plasma boundary and no blue core appears in the axial center of tube, which is always observed in argon W-mode discharge. The "big blue" or blue core is a special character in helicon plasma, but it has not been observed in nitrogen helicon plasma. In nitrogen-argon mixtures, a weak blue core is observed in ICCD images since the nitrogen content is increased. The electric field turns to the periphery in the distribution of the radial field and the electron temperature decreases with the increasing nitrogen content, especially when the blue core disappears. The different behaviors of the electron impact and the energy consumption in nitrogen helicon plasma are suggested to be responsible for the decrease in electron energy and the change in the electric field distribution.

  12. Nitrogen waste from rainbow trout (Oncorhynchus mykiss) with particular focus on urea

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Larsen, Bodil Katrine; Pedersen, Per Bovbjerg

    2015-01-01

    a laboratory, mass-balance approach, the current study examined the effects of commercially applied feeding levels on the loading of different N waste forms, including daily fluctuations in dissolved total nitrogen (TN), total ammonia nitrogen (TAN), urea-N, and non-characterized, dissolved N deriving from...... juvenile rainbow trout (Oncorhynchus mykiss). In addition, the study examined whether there was a removal of urea-N across a moving bed biofilter operated as end-of-pipe under commercial conditions. The laboratory, mass-balance study showed that there were no effects of feeding levels (1.3, 1.5 or 1....../nitrogen. Results from the commercially operated, nitrifying biofilter showed that urea-N was removed at a rate of 0.014 g N m2 day−1. Compared to the removal of TAN (0.208 g N m2 day−1), the moving bed biofilter was 1.07 times more active in removing dissolved N than immediately expected when only considering TAN...

  13. Pemanfaatan Urea sebagai Sumber Nitrogen pada Biosolubisasi Batubara oleh Trichoderma sp.

    Directory of Open Access Journals (Sweden)

    Novi Mulyawati

    2016-03-01

    Full Text Available Lignite coal was found abundant in Indonesia, but usage for this type of coal was still relatively low. Economic value of coal increases when it is solubilized. Biosolubilization of coal by utilize of microbes produces compounds equivalent to petroleum. In this research, effect of urea on lignite biosolubilization by Trichoderma sp. was examined. Method of this research consisted of spore inoculum preparation, biosolubilization lignite coal with a variety of treatment that consists of treatment A (MSS + sucrose  1% + coal 5% + urea, and treatment B (MSS + sucrose  1% + coal 5%. Results showed that the addition of urea supported lignit coal biosolubilization by Trichoderma sp. based on increase in medium pH, concentration of phenolic and conjugated aromatic compounds, and activity of extracellular enzyme. In addition, result of product characterization using GCMS revealed compounds equivalent to 13,60%, 26,20% and 90,8% respectively for gasoline, kerosene and diesel components. Those confirmed that urea can be used as an alternative nitrogen source to support Trichoderma sp. in lignit biosolubilization producing petroleum compounds.

  14. Hygroscopicity and ammonia volatilization losses from nitrogen sources in coated urea

    Directory of Open Access Journals (Sweden)

    Letícia de Abreu Faria

    2014-06-01

    Full Text Available Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; and by stabilized fertilizers, which prolong the period during which N remains in the amide or ammonia forms by urease inhibitors. This study evaluated the hygroscopicity of and ammonia volatilization from urea coated with boric acid and copper sulfate or with sulfur. The hygroscopicity of the sources was evaluated over time after exposure to five levels of relative humidity (RH and volatilization evaluated after application to the soil surface covered with sugarcane trash. Ammonium nitrate has a low potential for volatilization losses, but is highly hygroscopic. Although coating with boric acid and copper sulfate or elemental sulfur reduced the critical humidity level of urea, the delay in the volatilization process is a potential positive factor.

  15. Role of rumen butyrate in regulation of nitrogen utilization and urea nitrogen kinetics in growing sheep.

    Science.gov (United States)

    Agarwal, U; Hu, Q; Baldwin, R L; Bequette, B J

    2015-05-01

    Butyrate, a major rumen VFA, has been indirectly linked to enhancement of urea recycling on the basis of increased expression of urea transporter in the rumen epithelia of steers fed a rumen butyrate-enhancing diet. Two studies were conducted to quantify the effect of elevated rumen butyrate concentrations on N balance, urea kinetics and rumen epithelial proliferation. Wether sheep (n= 4), fitted with a rumen cannula, were fed a pelleted ration (∼165 g CP/kg DM, 10.3 MJ ME/kg DM) at 1.8 × ME requirement. In Exp. 1, sheep were infused intraruminally with either an electrolyte buffer solution (Con-Buf) or butyrate dissolved in the buffer solution (But-Buf) during 8-d periods in a balanced crossover design. In Exp. 2, sheep were infused intraruminally with either sodium acetate (Na-Ac) or sodium butyrate (Na-But) for 9 d. All solutions were adjusted to pH 6.8 and 8.0 in Exp. 1 and 2, respectively, and VFA were infused at 10% of ME intake. [15N2] urea was continuously infused intravenously for the last 5 d of each period, and total urine and feces were collected. In Exp. 1, 2H5-phenylalanine was continuously infused intravenously over the last 12 h, after which a biopsy from the rumen papillae was taken for measurement of fractional protein synthesis rate (FSR). Butyrate infusion treatments increased (P = 0.1 in Exp. 1; P urea entry (synthesis) rate was reduced ( urea kinetics were not altered by But-Buf compared with Con-Buf. These studies are the first to directly assess the role of butyrate in urea recycling and its effects on rumen papillae protein turnover in growing lambs. Under the feeding conditions used and the rate of continuous butyrate infusion into the rumen in the present studies, butyrate does not affect overall N retention in growing sheep. However, butyrate may play a role in the redistribution of urea N fluxes in the overall scheme of N metabolism.

  16. Urea recycling contributes to nitrogen retention in calves fed milk replacer and low-protein solid feed.

    Science.gov (United States)

    Berends, Harma; van den Borne, Joost J G C; Røjen, Betina A; van Baal, Jürgen; Gerrits, Walter J J

    2014-07-01

    Urea recycling, with urea originating from catabolism of amino acids and hepatic detoxification of ammonia, is particularly relevant for ruminant animals, in which microbial protein contributes substantially to the metabolizable protein supply. However, the quantitative contribution of urea recycling to protein anabolism in calves during the transition from preruminants (milk-fed calves) to ruminants [solid feed (SF)-fed calves] is unknown. The aim of this study was to quantify urea recycling in milk-fed calves when provided with low-protein SF. Forty-eight calves [164 ± 1.6 kg body weight (BW)] were assigned to 1 of 4 SF levels [0, 9, 18, and 27 g of dry matter (DM) SF · kg BW(-0.75) · d⁻¹] provided in addition to an identical amount of milk replacer. Urea recycling was quantified after a 24-h intravenous infusion of [¹⁵N₂]urea by analyzing urea isotopomers in 68-h fecal and urinary collections. Real-time qPCR was used to measure gene expression levels of bovine urea transporter B (bUTB) and aquaglyceroporin-3 and aquaglyceroporin-7 in rumen wall tissues. For every incremental gram of DM SF intake (g DM · kg(0.75)), nitrogen intake increased by 0.70 g, and nitrogen retention increased by 0.55 g (P intake, but aquaglyceroporin-7 expression did not. We conclude that in addition to the increase in digested nitrogen, urea recycling contributes to the observed increase in nitrogen retention with increasing SF intake in milk-fed calves. Furthermore, ruminal bUTB and aquaglyceroporin-3 expression are upregulated with SF intake, which might be associated with urea recycling. © 2014 American Society for Nutrition.

  17. Ruminal nitrogen metabolism in steers as affected by feed intake and dietary urea concentration

    International Nuclear Information System (INIS)

    Firkins, J.L.; Berger, L.L.; Merchen, N.R.; Fahey, G.C. Jr.; Mulvaney, R.L.

    1987-01-01

    Four multiple-cannulated steers (340 kg) were used in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Steers were fed a diet of 50% ground hay and 50% concentrate at two intakes (1.4 and 2.1% of BW), with urea and 15 N-enriched ammonium sulfate infused continuously into the rumen at .4 or 1.2% of diet DM. Ratios of purines and diaminopimelic acid-N to N in fluid-associated and particulate-associated bacteria and in protozoa were similar among treatments but were lower for protozoa than for bacteria. Diaminopimelic acid-N:N was higher for fluid-associated vs. particulate-associated bacteria. Enrichment of 15 N was similar between bacteria among treatments and was 30% lower for protozoa. Turnover rates of 15 N in bacteria, NH 3 N, and non-HN 3 N pools were faster for steers infused with 1.2 than those infused with .4% urea, indicating less efficient usage of ammonia with higher urea. A method is described to estimate the proportion of duodenal nitrogen comprising bacterial and protozoal nitrogen

  18. Effect of dietary nitrogen content and intravenous urea infusion on ruminal and portal-drained visceral extraction of arterial urea in lactating Holstein cows.

    Science.gov (United States)

    Kristensen, N B; Storm, A C; Larsen, M

    2010-06-01

    Urea extraction across ruminal and portal-drained visceral (PDV) tissues were investigated using 9 rumen-cannulated and multi-catheterized lactating dairy cows adapted to low-N (12.9% crude protein) and high-N (17.1% crude protein) diets in a crossover design. The interaction between adaptation to dietary treatments and blood plasma concentrations of urea was studied by dividing samplings into a 2.5-h period without urea infusion followed by a 2.5-h period with primed continuous intravenous infusion of urea (0.493+/-0.012 mmol/kg of BW per h). Cows were sampled at 66+/-14 and 68+/-12 d in milk and produced 42+/-1 and 36+/-1 kg of milk/d with the high-N and low-N diets, respectively. The arterial blood urea concentration before urea infusion was 1.37 and 4.09+/-0.18 mmol/L with low-N and high-N, respectively. Dietary treatment did not affect the urea infusion-induced increase in arterial urea concentration (1.91+/-0.13 mmol/L). Arterial urea extraction across the PDV and rumen increased from 2.7 to 5.4+/-0.5% and from 7.1 to 23.8+/-2.1% when cows were changed from high-N to low-N, respectively. Urea infusion did not decrease urea extractions, implying that urea transport rates were proportional to arterial urea concentrations. Urea extraction increased more across the rumen wall than across the total PDV for low-N compared with high-N, which implies that a larger proportion of total PDV uptake of arterial urea is directed toward the rumen with decreasing N intake. The ruminal vein - arterial (RA) concentration difference for ammonia increased instantly (first sampling 15 min after initiation of infusion) to the primed intravenous infusion when cows were adapted to the low-N diet. The RA difference for ammonia correlated poorly to the ventral ruminal concentration of ammonia (r=0.55). Relating the RA difference for ammonia to a function of both ruminal ammonia concentration and the RA difference for urea markedly improved the fit (r=0.85), indicating that a large

  19. Nitrogen management and nitrification inhibitor effects on nitrogen-15 urea: 1. Yield and fertilizer use efficiency

    International Nuclear Information System (INIS)

    Walters, D.T.; Malzer, G.L.

    1990-01-01

    Nitrification inhibitors (NI) are sometimes recommended for use with ammoniacal fertilizers in corn (Zea mays L.) production to improve fertilizer N use efficiency (FUE). The objectives of this experiment were to evaluate the effects of the NI nitrapyrin [2-chloro-6-(trichloromethyl) pyridine] application on yield and FUE of irrigated corn, and to monitor the fate of a single application of 15 N-enriched urea during a multiyear period in both soil and plant. Treatments included a factorial combination of two N rates (90 or 180 kg urea-N ha -1 yr -1 ) applied during a 3-yr period, with or without a NI and with or without incorporation, plus a zero-N control. Twenty-seven nonweighing lysimeters were used to quantify leaching load. Treatment effects on yield and FUE differed each year due to interactions of climate and N-management variables. Nonincorporated urea + NI reduced grain yield when leaching load was low and increased yield at the 90 kg ha -1 N rate when leaching load was low. The NI increased FUE only at the 90 kg ha -1 N rate when leaching load was high. Incorporation of urea + NI reduced plant recovery of fertilizer-derived N (FDN) in the year of application, but resulted in increased uptake of residual FDN in subsequent years. Incorporation of NI with moderate N rates coupled with conservative irrigation management should reduce the risk of yield loss and minimize NO 3 movement to groundwater

  20. Sulfonamide antibiotic removal and nitrogen recovery from synthetic urine by the combination of rotating advanced oxidation contactor and methylene urea synthesis process

    OpenAIRE

    Fukahori, S.; Fujiwara, T.; Ito, R.; Funamizu, N.

    2015-01-01

    The combination of nitrogen recovery and pharmaceutical removal processes for livestock urine treatment were investigated to suppress the discharge of pollutants and recover nitrogen as resources. We combined methylene urea synthesis from urea and adsorption and photocatalytic decomposition of sulfonamide antibiotic using rotating advanced oxidation contactor (RAOC) contained for obtaining both safe fertilizer and reclaimed water. The methylene urea synthesis could recover urea in synthetic u...

  1. Propionate supplementation improves nitrogen use by reducing urea flux in sheep.

    Science.gov (United States)

    Agarwal, U; Hu, Q; Bequette, B J

    2015-10-01

    Feeding and postruminal infusion of propionate is known to increase N retention in ruminants. Our aim was to determine the role of rumen propionate on urea N recycling and gluconeogenesis in growing sheep. In Exp. 1, wether sheep ( = 6; 32.5 ± 3.57 kg BW) fitted with a rumen cannula were fed to 1.8 × ME requirement a concentrate-type ration (172 g CP/kg DM and 10.4 MJ ME/kg DM) and continuously infused into the rumen with isoenergetic (10% of dietary ME intake) solutions of either sodium acetate (control) or sodium propionate for 9-d periods in a crossover design. In Exp. 2, a different group of wether sheep ( = 5; 33.6 ± 3.70 kg BW) fitted with a rumen cannula were fed, on an isonitrogenous basis, either a control (151 g CP/kg DM and 8.4 MJ ME/kg DM) or sodium propionate-supplemented (139 g CP/kg DM and 8.9 MJ ME/kg DM) diet at 2-h intervals. [N] urea was continuously infused intravenously for the last 5 d of each period, and total urine was collected by vacuum and feces were collected by a harness bag. Over the last 12 h, [C]glucose was continuously infused intravenously and hourly blood samples were collected during the last 5 h. Propionate treatments increased ( urea entry (synthesis) rate (UER) in Exp. 1; however, sodium propionate infusion tended ( urea elimination (UUE). In Exp. 2, feeding propionate increased ( urea N/d, leading to a reduction ( urea N/d). Between the 2 experiments, the proportion of UER recycled to the gut was greater with the forage-type diet in Exp. 2 (approximately 60%) compared with the concentrate-type diet in Exp. 1 (approximately 40%), although urea N fluxes across the gut remained unchanged in both experiments. In Exp. 1, glucose entry and gluconeogenesis were greater ( < 0.05) and plasma glucose tended ( < 0.1) to be greater with sodium propionate infusion than with sodium acetate infusion, but there was no difference in Cori cycling. In Exp. 2, glucose entry, gluconeogenesis, Cori cycling, and plasma glucose increased ( < 0

  2. Transfer of blood urea nitrogen to cecal microbial nitrogen is increased by fructo-oligosaccharide feeding in guinea pigs.

    Science.gov (United States)

    Kawasaki, Kiyonori; Min, Xiao; Li, Xiao; Hasegawa, Ena; Sakaguchi, Ei

    2015-01-01

    The present study was conducted to determine the mechanism by which nitrogen (N) availability is improved by fructo-oligosaccharide (FOS) in guinea pigs. Adult male guinea pigs were fed a commercial pellet diet (50 g/day) with either 5% glucose or 5% FOS for 7 days in individual metabolism cages. After 7 days of feeding the diet, (15) N-urea was administered intravenously 1 h before slaughter under anesthesia. The amount and concentration of total, protein, bacterial, ammonia and urea N and the (15) N atom % excess were measured in blood, liver, gut contents and urine. The (15) N atom % excess of total and protein N, and the amount of total, protein and bacteria N and (15) N in the cecum were significantly increased by the consumption of FOS. Furthermore, the concentration and amount of short-chain fatty acids were significantly increased by the consumption of FOS. In contrast, the amount of urinary (15) N was significantly decreased by the consumption of FOS. These results suggest that consumption of FOS increases transfer of blood urea N into the large intestine for bacterial N synthesis, which is subsequently re-absorbed by cecotrophy, and contributes to the increase of N utilization in guinea pigs. © 2014 Japanese Society of Animal Science.

  3. Plasma basic concepts and nitrogen containing plasmas

    OpenAIRE

    Sanz Lluch, M. del Mar; Tanarro, Isabel

    2007-01-01

    Basic concepts related to plasmas are described as well as the typical characterization methods currently available. A brief overview about some plasma applications is given, but focusing on plasma used in material processing mainly devoted to the microelectronics industry. Finally, specific applications related to plasma-assisted MBE for nitrides and dilute nitrides are given, showing some interesting research works performed to that purpose, and giving the usual characterization techniques ...

  4. Sulfonamide antibiotic removal and nitrogen recovery from synthetic urine by the combination of rotating advanced oxidation contactor and methylene urea synthesis process.

    Science.gov (United States)

    Fukahori, S; Fujiwara, T; Ito, R; Funamizu, N

    2015-01-01

    The combination of nitrogen recovery and pharmaceutical removal processes for livestock urine treatment were investigated to suppress the discharge of pollutants and recover nitrogen as resources. We combined methylene urea synthesis from urea and adsorption and photocatalytic decomposition of sulfonamide antibiotic using rotating advanced oxidation contactor (RAOC) contained for obtaining both safe fertilizer and reclaimed water. The methylene urea synthesis could recover urea in synthetic urine, however, almost all sulfonamide antibiotic was also incorporated, which is unfavorable from a safety aspect if the methylene urea is to be used as fertilizer. Conversely, RAOC could remove sulfonamide antibiotic without consuming urea. It was also confirmed that the methylene urea could be synthesized from synthetic urine treated by RAOC. Thus, we concluded that RAOC should be inserted prior to the nitrogen recovery process for effective treatment of urine and safe use of methylene urea as fertilizer.

  5. Prediction of urinary nitrogen and urinary urea nitrogen excretion by lactating dairy cattle in northwestern Europe and North America: A meta-analysis

    NARCIS (Netherlands)

    Spek, J.W.; Dijkstra, J.; Duinkerken, van G.; Hendriks, W.H.; Bannink, A.

    2013-01-01

    A meta-analysis was conducted on the effect of dietary and animal factors on the excretion of total urinary nitrogen (UN) and urinary urea nitrogen (UUN) in lactating dairy cattle in North America (NA) and northwestern Europe (EU). Mean treatment data were used from 47 trials carried out in NA and

  6. Effect of dietary protein level on nitrogen utilization and ruminal influx of endogenous urea nitrogen in growing animals

    International Nuclear Information System (INIS)

    Bunting, L.D.

    1987-01-01

    Three experiments were conducted to evaluate the impact of ruminal influx of blood urea nitrogen (BUN) on intestinal protein supply and nitrogen (N) metabolism in growing animals at both excess and growth-limiting protein intake. In Experiment 1, wether lambs were given diets, either high or low in protein, containing 25% cottonseed hulls and 75% corn-soybean meal hourly in 24 equal portions. Single injections of 14 C- and 15 N-urea, and 15 N-ammonium sulfate (AS) were made into the BUN and ruminal ammonia N (RAN) pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. In Experiment 2, beef calves were given HP and LP diets containing 30% cottonseed hulls and 70% corn-soybean meal every 4 h in 6 equal portions. Single injections of 15 N-urea and 15 N-AS were made into the BUN and RAN pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. Abomasal N flow was 24% greater than intake in LP and 29% less than intake in HP. An inverse relationship may exist between level of N intake and rate of influx of BUN into the rumen. In Experiment 3 ruminal fluid samples were obtained. With HP, BUN-derived 15 N-ammonia appeared to rapidly equilibrate with RAN in the primary digesta mass. In contrast, with LP, there appeared to be an enrichment gradient for both RAN and bacterial N, declining from the rumen wall toward the center of the digesta mass, suggesting that bacteria at or near the rumen wall may preferentially utilized some BUN-derived ammonia N entering through the rumen wall

  7. Plasma catalysis for nitrogen fixation reactions

    NARCIS (Netherlands)

    Patil, B.S.; Wang, Q.; Hessel, V.; Lang, J.; Stankiewicz, A.; Stefanidis, G.

    2016-01-01

    The preferences for localized chemicals production and changing scenarios of renewable electricity cost gives a renewed boost to plasma-assisted valuable chemicals production. Especially, plasma-assisted nitrogen fixation for fertilizer production has the potential to largely change the energy

  8. Utilization of residual nitrogen (15N) from cover crop and urea by corn

    International Nuclear Information System (INIS)

    Silva, Edson Cabral da; Muraoka, Takashi; Trivelin, Paulo Cesar Ocheuze; Buzetti, Salatier; Veloso, Marcos Emanuel da Costa

    2006-01-01

    The majority of N from mineral fertilizers and cover crops is usually not used by the very next corn crop, but can be absorbed by follow-up crops. The objective of this study was to evaluate the use of residual nitrogen from urea, sunnhemp (Crotalaria juncea) and millet (Pennisetum americanum) labeled with 15 N, applied to no-tillage corn in the previous growing season, in a Red Latosol of the Cerrado. The study was conducted in an experimental farm of the Sao Paulo State University (UNESP), Ilha Solteira, in Selviria county (MS), Brazil, in different areas. The experiment had a randomized complete block design, with 15 treatments and four replications. Treatments were applied to corn crop in the 2001/02 and 2003/04 growing seasons. They were distributed in a 3 x 5 factorial layout, representing the combination of three cover crops: sunnhemp, millet and spontaneous vegetation (fallow) and five N rates (as urea): 0, 30, 80, 130, and 180 kg ha-1 of N. After corn harvest, the two areas were followed in the dry season and were followed by corn crop in the 2002/03 (experiment 1) and 2003/04 (experiment 2) growing seasons, using the same fertilizer rate on all plots to distinguish the residual effect of N sources. The average use of residual N from the millet and sunnhemp residues (above-ground part) by corn crop was less than 3.5 and 3 %, respectively, of the initial amount. The corn uptake of residual N from urea increased in a quadratic manner in experiment 1 and linearly in experiment Two as a response to the applied N rates, and the recover was below 3 %. The cover crop type did not affect the use of residual N of urea by corn, and vice-versa. (author)

  9. Variáveis ruminais, concentração de uréia plasmática e excreções urinárias de nitrogênio em vacas leiteiras alimentadas com concentrado processado de diferentes formas Ruminal metabolism, plasma urea concentration, and urinary excretion of nitrogen of dairy cows fed concentrate processed in different forms

    Directory of Open Access Journals (Sweden)

    Humberto Luiz Wernersbach Filho

    2006-06-01

    at 3 h post-feeding on cows fed diets contained extruded concentrate. Plasma urea did not differ across diets while for urinary excretion of nitrogen a significant difference was observed only for the diet containing the partially processed high-energy concentrate.

  10. Undernutrition and serum and urinary urea nitrogen of white-tailed deer during winter

    Science.gov (United States)

    DelGiudice, G.D.; Mech, L.D.; Seal, U.S.

    1994-01-01

    Direct, practical means of assessing undernutrition in deer (Odocoileus spp.) and other ungulates during winter are needed in areas of research and management. We examined the relationship between mass loss and serum urea nitrogen (SUN) and urinary urea nitrogen:creatinine (U:C) in captive white-tailed deer (O. virginianus). During 4 February-5 May 1988, we maintained 7 adult white-tailed deer on various feeding regimes to simulate natural nutritional restriction during winter. Mass loss was greater (P = 0.037) in deer (17.0-32.2%) fed restricted amounts of a low protein low energy diet versus control deer (7.0-17.4%) fed the same diet ad libitum. Serum triiodothyronine (T3) concentrations did not differ (P = 0.191) between groups, but declined (P = 0.001) as nutrition declined. Slopes of percent mass lossSUN and urinary U:C relationships were positive (P = 0.008 and 0.055) in 7 and 6 deer, respectively. Mean U:C was directly related (r2 = 0.52, P = 0.040) to mean cumulative mass loss, whereas mean SUN was not (r2 = 0.29, P = 0.125). Data presented support the potential of urinary U:C as an index of winter nutritional condition of white-tailed deer; however, additional research is required to provide a complete understanding of this index's utility under field conditions.

  11. Assimilation of 15N-labelled urea nitrogen and ammonium nitrate nitrogen by plants in case of root and non-root fertilization

    International Nuclear Information System (INIS)

    Muravin, Eh.A.; Kozhemyachko, V.A.; Vernichenko, I.V.

    1974-01-01

    Assimilation of 15 N labeled urea and ammonium nitrate in root and foliar application by spring wheat and barley has been studied during 1970-1973 period in a series of vegetative experiments at the Department of Agrochemistry, Timiryazev Agricultural Academy, and at D.N. Pryanishnikov Experimental Agrochemical Station. Additional fertilizer nitrogen applied at later ontogenesis stages (flowering and milky ripeness) is utilized mostly for protein synthesis in developing grains, thus leading to a significant increase in the relative grain protein content. A transfer of a part of nitrogen from the main ortion of fertilizer at later stages of nitrition results, at the same time, in a lower yield. Nitrogen utilization degree of urea and ammonium nitrate, when introduced before sowing or at the flowering stage is similar but in the latter case, however, additional assimilation of soil nitrogen is lower. The assimilation rate of nitrogen in root application is the lower the later the fertilizer is applied. When ammonium nitrate is additionally applied as nutrition to barley at the milky ripeness stage, ammonia and nitrate nitrogen are assimilated at the same rate and to the same extent but ammonia nitrogen is more rapidly used for protein synthesis and the rate of its transfer to the developing grains is higher. The rate of nitrogen assimilation at plant is much higher in foliar than in root application. Wheat utilizes more urea nitrogen at the flowering stage when root application is used but at the milky ripeness stage foliar application is more effective

  12. Assimilation of /sup 15/N-labelled urea nitrogen and ammonium nitrate nitrogen by plants in case of root and non-root fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Muravin, E A; Kozhemyachko, V A; Vernichenko, I V

    1974-01-01

    Assimilation of /sup 15/N labeled urea and ammonium nitrate in root and foliar application by spring wheat and barley has been studied during 1970-1973 period in a series of vegetative experiments at the Department of Agrochemistry, Timiryazev Agricultural Academy, and at D.N. Pryanishnikov Experimental Agrochemical Station. Additional fertilizer nitrogen applied at later ontogenesis stages (flowering and milky ripeness) is utilized mostly for protein synthesis in developing grains, thus leading to a significant increase in the relative grain protein content. A transfer of a part of nitrogen from the main portion of fertilizer at later stages of nitrition results, at the same time, in a lower yield. Nitrogen utilization degree of urea and ammonium nitrate, when introduced before sowing or at the flowering stage is similar but in the latter case, however, additional assimilation of soil nitrogen is lower. The assimilation rate of nitrogen in root application is the lower the later the fertilizer is applied. When ammonium nitrate is additionally applied as nutrition to barley at the milky ripeness stage, ammonia and nitrate nitrogen are assimilated at the same rate and to the same extent but ammonia nitrogen is more rapidly used for protein synthesis and the rate of its transfer to the developing grains is higher. The rate of nitrogen assimilation at plant is much higher in foliar than in root application. Wheat utilizes more urea nitrogen at the flowering stage when root application is used but at the milky ripeness stage foliar application is more effective.

  13. Fontes de lipídeos na dieta de búfalas lactantes: consumo, digestibilidade e N-uréico plasmático Effects of dietary fat sources on intake, nutrient digestibility and plasma urea nitrogen for lactating water buffaloes

    Directory of Open Access Journals (Sweden)

    Ronaldo Lopes Oliveira

    2009-03-01

    Full Text Available Os efeitos da suplementação de fontes lipídicas sobre o consumo, a digestibilidade dos nutrientes e o N-uréico plasmático foram avaliados em 12 búfalas lactantes, em três quadrados latinos simultâneos, cada um com quatro animais, quatro períodos e quatro dietas contendo uma das fontes de lípideo estudadas (sem lipídeo adicional; grão de soja; óleo de soja ou caroço de algodão. O período experimental foi de 84 dias, com quatro períodos de 21 dias, divididos em 14 dias para a adaptação e 7 para coleta. A dieta foi fornecida à vontade, duas vezes ao dia, na forma de mistura completa. Nos dias de coleta de cada período, os alimentos fornecidos e as sobras foram pesados e amostrados para análise bromatológica. Amostras de fezes foram coletadas diretamente no reto dos animais para estimativa da produção de matéria seca fecal, utilizando-se a fibra em detergente neutro indigestível como indicador, e para o cálculo de digestibilidade aparente. Os consumos de matéria seca, proteína bruta, fibra em detergente neutro e fibra em detergente ácido foram semelhantes entre as dietas. Os consumos de extrato etéreo e nutrientes digestíveis totais (NDT foram maiores para a dieta com óleo de soja. Os coeficientes de digestibilidade de matéria seca, proteína bruta e carboidratos não-fibrosos e as concentrações de N-uréico plasmático foram semelhantes entre as dietas. A utilização das fontes de lipídeos nas dietas de búfalas em lactação não influenciou o consumo e coeficiente de digestibilidade da matéria seca. Entretanto, as digestibilidades do extrato etéreo da dieta com grão de soja e das frações fibrosas da dieta com caroço de algodão foram as mais baixas.The effects of fat sources on intake, nutrient digestibility and plasma urea nitrogen were evaluated in lactating water buffalo. Twelve females were randomly distributed into four treatments: without additional lipid, soybean grain, soybean oil and

  14. Isotopic studies of urea metabolism in rabbits

    Science.gov (United States)

    Regoeczi, E.; Irons, L.; Koj, A.; McFarlane, A. S.

    1965-01-01

    1. The half-life of [15N]urea was found to be significantly longer than that of [14C]urea injected at the same time, the differences being due to endogenous catabolism of urea, which is accompanied by little or no reutilization of 14C but is approx. 20% for 15N. [15N]Urea therefore appears to be valueless as an indicator of nitrogen metabolism unless the extents of endogenous catabolism of urea and of fractional reutilization of 15N can be separately estimated. 2. Though measurements of the radioactivity of expired 14CO2 confirmed the existence of considerable urea catabolism these could not be used for quantitative assessments. 3. Alternative graphical methods based on [14C]urea specific activities in plasma and urine samples were used to calculate the fraction of urea production that is excreted. Values by the two methods were in good agreement and showed that some animals excrete less than half the urea that they produce. 4. Specific activity differences between simultaneous samples of urinary and plasma urea reflect the presence of a pool of urea in the kidney that is not in equilibrium with the body urea pool. Calculations indicate the presence of urea in the kidney that in some cases may represent as much as 15% of the body pool, and in two animals in which post-mortem renal analyses were performed the masses of urea found agreed closely with the calculated values. 5. A model for urea metabolism is proposed that includes this pool in the excretory pathway. The related theory is shown to be adequate to explain the shape of the specific activity curves of urinary urea from the time of injection and the constant delay of the specific activity of urinary urea, relative to that of plasma urea, that is observed after a short preliminary equilibration period. 6. The body urea pool was calculated from the activity retained at 1·5hr. by excluding renal activity and the corrected specific activity of plasma urea at the same time. The urea pool was calculated to be

  15. Computational modeling to predict nitrogen balance during acute metabolic decompensation in patients with urea cycle disorders.

    Science.gov (United States)

    MacLeod, Erin L; Hall, Kevin D; McGuire, Peter J

    2016-01-01

    Nutritional management of acute metabolic decompensation in amino acid inborn errors of metabolism (AA IEM) aims to restore nitrogen balance. While nutritional recommendations have been published, they have never been rigorously evaluated. Furthermore, despite these recommendations, there is a wide variation in the nutritional strategies employed amongst providers, particularly regarding the inclusion of parenteral lipids for protein-free caloric support. Since randomized clinical trials during acute metabolic decompensation are difficult and potentially dangerous, mathematical modeling of metabolism can serve as a surrogate for the preclinical evaluation of nutritional interventions aimed at restoring nitrogen balance during acute decompensation in AA IEM. A validated computational model of human macronutrient metabolism was adapted to predict nitrogen balance in response to various nutritional interventions in a simulated patient with a urea cycle disorder (UCD) during acute metabolic decompensation due to dietary non-adherence or infection. The nutritional interventions were constructed from published recommendations as well as clinical anecdotes. Overall, dextrose alone (DEX) was predicted to be better at restoring nitrogen balance and limiting nitrogen excretion during dietary non-adherence and infection scenarios, suggesting that the published recommended nutritional strategy involving dextrose and parenteral lipids (ISO) may be suboptimal. The implications for patients with AA IEM are that the medical course during acute metabolic decompensation may be influenced by the choice of protein-free caloric support. These results are also applicable to intensive care patients undergoing catabolism (postoperative phase or sepsis), where parenteral nutritional support aimed at restoring nitrogen balance may be more tailored regarding metabolic fuel selection.

  16. Effect of formaldehyde-treated urea on rumen fermentation, ration digestibility and nitrogen utilization

    Directory of Open Access Journals (Sweden)

    Jouko Setälä

    1982-01-01

    Full Text Available The study comprises two experiments in which young Finn-sheep were used as test animals. The experimental rations consisted of equal parts of NaOH-treated wheat (Exp. 1 or barley (Exp. 2 straw and a concentrate mixture of barley-molassed beet pulp (Exp. 1 or barley-oats-molassed beet pulp (Exp.2. Feeding was performed twice a day. In addition 20 grams of urea/animal/day was mixed into the concentrates just before feeding. The urea was treated with the following percentages of formaldehyde, on a weight basis: 0 (F0, 1.0 (F1.0, 3.0(F3.0 and 5.0(F5.0 in Exp. 1 and 0, 1.0 and 1.5(F1.5 in Exp. 2. The digestibility of the total ration decreased, when F3.0 and F5.0 urea was used, but the decrease was significant (P< 0.05 only when the apparent digestibility of crude protein was compared between the F0 and F5.0 diets. The amount of rumen bacteria was decreased (P< 0.05 and the amount of protozoa increased (P< 0.01 by formaldehyde treatment levels above F1.0 and F3.0, respectively. The concentration of the total VFA in the rumen tended to decrease with treatment levels higher than F3.0. No significant differences were found in the composition of the VFA. When treated urea was used, the excretion of nitrogen in the faeces increased but its excretion in the urine decreased. The percentage retention of the nitrogen ingested by the animals on diets F0, F1.0, F3.0, and F5.0 in Exp. 1 was 15.0, 10.8, 13.2 and 12.2 and on diets F0, F1.0 and F1.5 in Exp. 2 it was 20.5, 20.2 and 21.2, respectively.

  17. The Effect of Percentage of Nitrogen in Plasma Gas on Nitrogen ...

    African Journals Online (AJOL)

    Increase in nitrogen percent in the plasma gas results in increased content of dissociated nitrogen and molecular nitrogen possessing excess vibrational energy and therefore the increased solution of nitrogen in the liquid iron. It would appear that above 35% nitrogen in the plasma gas, frequency of collisions of species in ...

  18. Comparison between Urea and Goat Manure as Sources of Nitrogen for Napier Grass Grown on Terraced Hill

    Directory of Open Access Journals (Sweden)

    Rahman, M.M.

    2016-12-01

    Full Text Available Effects of two nitrogen (N sources on dry matter (DM yield and nutritive value of Napier grass were evaluated. The nitrogen (N fertiliser (at rate of 300 kg N ha?1 year?1 was applied by dividing the terraces of a hill under two treatments: T1 (urea and T2 (goat manure. There were three replicates of each treatment arranged within three blocks in a completely randomised design. Grass was cut at about 60?day interval. In the first to fourth harvests, grass receiving manure had higher plant height than those with urea application. Grass receiving manure had higher DM yield than urea in almost all of the cuttings. In the fourth harvest, grass receiving urea contained higher DM and organic matter (OM than manure. Similar result was found for fifth harvest where urea gave higher crude protein (CP than manure. Irrespective of harvesting frequencies, average DM, OM, CP and neutral detergent fibre contents were not significantly different between grasses fertilised with manure and urea. In conclusion, manure is recommended for economical cultivation of Napier grass on terrace of hill.

  19. Utilization of dietary urea in rainbow trout.

    Science.gov (United States)

    Kaushik, S J; Dabrowski, K R; Dabrowska, H; Olah, E; Luquet, P

    1983-01-01

    Experiments were conducted to examine the potential utilization of dietary urea by rainbow trout. A control diet and two diets supplemented with 1 and 3% of urea were fed to fish. Postprandial levels of urea and ammonia in blood plasma, and postprandial excretion of these metabolites were followed during 24 h. Apparent digestibility of urea in rainbow trout was very high (greater than 98%). Maximum values of urea levels in plasma were reached 6 h (32.3 +/- 10.2 micrograms/ml) after a meal in the control fish and respectively 6 h (83.4 +/- 18.4 micrograms/ml) and 8 h (250.3 +/- 96.1 micrograms/ml) after a meal in trout fed 1 and 3% urea diets. Peaks of urea excretion rates appeared 7-9 h after meal, coinciding with the highest circulating urea concentration. Total daily urea excretion amounted to 5.53, 10.43 and 33.80 mg urea N/100 mg N intake in trout fed the control, 1 and 3% urea diets, respectively. It is concluded that the dietary urea is readily absorbed in the digestive tract of trout but is totally excreted thus leading to no beneficial effect on nitrogen balance. This excretion of urea also takes place passively without any increase in energy demands.

  20. The influence of nitrogen - urea fertilization to leaves and chloride chlorocholine on the accumulation Cs-137 in spring wheat crops

    International Nuclear Information System (INIS)

    Hrynczuk, B.; Weber, R.

    1998-01-01

    In pot experiments were studied effects of using nitrogen urea solution to leaves and use chloride chlorocholine on the Cs-137 accumulation in spring wheat crops. The Cs-137 contamination was conducted from soil and through leaves. It has been found that use nitrogen fertilization as urea solution spray and in addition use chloride chlorocholine caused an increase of Cs-137 concentration in grain from the contaminated soil. Accumulation of Cs-137 in spring wheat grain is 2-4 times higher coming from the contaminated leaves in blooming phase in comparison to the grain of plants contaminated in spread phase. The urea solution fertilization used on leaves and addition chloride chlorocholine did not influence the Cs-137 accumulation in grain when the plants were contaminated in the early growing phase. The Cs-137 contamination brought on the plants after using chloride chlorocholine in subsequent growing phases passed early into spring wheat grain. (author)

  1. Ammonium Nitrogen Removal from Urea Fertilizer Plant Wastewater via Struvite Crystal Production

    Science.gov (United States)

    Machdar, I.; Depari, S. D.; Ulfa, R.; Muhammad, S.; Hisbullah, A. B.; Safrul, W.

    2018-05-01

    Elimination of ammonium concentration from urea fertilizer plant wastewater through struvite crystal (NH4MgPO4.6H2O) formation by adding MgCl2, KH2PO4, and KOH were studied. This method of elimination has two benefits, namely, reducing ammonium nitrogen content in the wastewater, as well as production of a valuable material (struvite crystal). Struvite is known as a slow-release fertilizer and less soluble. This report presents the ammonium removal efficiencies during struvite formation. The growth of struvite production under different molar ratios of Mg2+:NH4 +:PO4 3- and solution pH is also discussed. To find the efficiencies and measure the growth rates, lab-scale experiments were conducted in a batch crystallizer-reactor. SEM, XRD, and FTIR observation were also applied to investigate the characteristics of struvite. The reactant molar ratios of Mg2+:NH4 +:PO4 3- of 1.2:1:1, 1:1:1.2, and 1:1:1 were evaluated. Each of the molar ratios was treated at the solution pH of 8, 9, and 10. It was found that, the highest ammonium removal efficiency was 94.7% at the molar ratio of 1.2:1:1 and pH of 9. Primarily, the growth rate of struvite formation complied with a first-order kinetic model. The rate constants (k1) were calculated to be 2.6, 4.3, and 5.0 h-1 for solution pH of 8, 9, and 10, respectively. The findings of the study provide suggestion for an alternative sustainable recovery of ammonium nitrogen content in a urea fertilizer plant effluent.

  2. Evaluation of the Effect of Split application of Urea on Nitrogen Losses in Furrow Fertigation

    Directory of Open Access Journals (Sweden)

    farid feizolahpour

    2017-01-01

    Full Text Available Introduction: Broadcast fertilization method increases fertilizer losses while results in lower nutrient absorption by plant roots. Fertigation is an effective method to increase water and fertilizer efficiency and to reduce the losses of nitrogen. Moreover, it allows farmers to apply the nutrients in splits and few amounts in response to crop needs. In the present study, a field experiment was conducted to investigate the effects of split application of fertilizer in furrow fertigation on nitrogen losses and corn yield. Materials and Methods: Field experiments were carried out factorially in a randomized complete block design with four replicates. Experimental treatments were consisted of three fertilizer splits (two, three, and four splits and three levels of urea fertilizer (60, 80 and 100% of required urea fertilizer, which compared with the common method (broadcasting fertilizer as used by farmers in the fields. Experiments were conducted on a one hectare field in 120 meter long and open end furrows. During the crop season, Irrigation water was applied in the same way for all fertigation treatments and the third type of the WSC flumes was used to measure the amount of input and output water in irrigation events. Moreover, for determining the indexes of uniformity of water distribution in carrying out fertigation experiments, the amount of infiltration into the soil was calculated using the Kostiakov-Louis equation. The parameters of this equation were determined using the water volume balance method. Injection of Urea fertilizer was done by using 40-liter barrels were placed at the beginning of Furrows. In this study, the injection of fertilizers was applied in the last 10 to 20 minutes of irrigation time. Results and Discussions: Results showed that water distribution uniformities of low quarter and low half in all tests were very high. Such that the water low quarter distribution uniformities for all treatments were between 90.5 to 98

  3. The effect of urea fertiliser formulations on gross nitrogen transformations in a permanent grassland soil.

    Science.gov (United States)

    Harty, Mary; Mueller, Christoph; Laughlin, Ronnie; Watson, Catherine; Richards, Karl; Lanigan, Gary; Forrestal, Patrick; McGeough, Karen

    2015-04-01

    Introduction By 2050, the current food production rate will need to increase by 70 % in order to meet the needs of the projected world population (FAO, 2014). Under the climate change response bill, Ireland has a target to reduce GHG emissions by 20% by 2020. Agriculture was responsible for almost one third of Ireland's overall Greenhouse Gas (GHG) emissions in 2012, with 39% of these emissions arising from chemical/organic fertilisers in the form of nitrous oxide (N2O). N2O losses represent environmental damage through ozone depletion and global warming as well as acidification, eutrophication, surface and groundwater contamination and it also represents financial loss to the farmer (Cameron 2013). The contradictory aims of increasing food production while reducing GHG emissions will require an adjustment to the current system of agricultural production. As part of a larger study evaluating the switching of nitrogen (N) fertiliser formulation to minimise N2O emissions, (from calcium ammonium nitrate (CAN) to urea based formulations), this experiment examined the effect of urea based fertiliser formulations on gross N transformations in a permanent pasture soil at Hillsborough, Co. Down, Northern Ireland. Study Design/Methodology A laboratory incubation study was undertaken, to examine the effect of urea in various combinations with two types of inhibitors on soil N dynamics and N2O and N2 emissions. The inhibitors examined were the urease inhibitor N-(butyl) thiophosphoric triamide (nBTPT) and the nitrification inhibitor dicyandiamide (DCD). The fertiliser products were labelled with 15N and the soil was incubated at 15 ° C at a water filled pore space of 65%. Soil mineral N (urea, NH4+, NO2- and NO3-) concentrations, gaseous losses (N2O and N2) and the 15N enrichments of NH4+, NO2-, NO3-, N2O and N2were analysed on 8 separate occasions over 25 days. An adapted numerical 15N tracing model (Müller et al., 2007) was used to quantify the effect of the inhibitors on

  4. Interactions between barley grain processing and source of supplemental dietary fat on nitrogen metabolism and urea-nitrogen recycling in dairy cows.

    Science.gov (United States)

    Gozho, G N; Hobin, M R; Mutsvangwa, T

    2008-01-01

    The objective of this study was to determine the effects of methods of barley grain processing and source of supplemental fat on urea-N transfer to the gastrointestinal tract (GIT) and the utilization of this recycled urea-N in lactating dairy cows. Four ruminally cannulated Holstein cows (656.3 +/- 27.7 kg of BW; 79.8 +/- 12.3 d in milk) were used in a 4 x 4 Latin square design with 28-d periods and a 2 x 2 factorial arrangement of dietary treatments. Experimental diets contained dry-rolled barley or pelleted barley in combination with whole canola or whole flaxseed as supplemental fat sources. Nitrogen balance was measured from d 15 to 19, with concurrent measurements of urea-N kinetics using continuous intrajugular infusions of [15N 15N]-urea. Dry matter intake and N intake were higher in cows fed dry-rolled barley compared with those fed pelleted barley. Nitrogen retention was not affected by diet, but fecal N excretion was higher in cows fed dry-rolled barley than in those fed pelleted barley. Actual and energy-corrected milk yield were not affected by diet. Milk fat content and milk fat yield were higher in cows fed dry-rolled barley compared with those fed pelleted barley. Source of supplemental fat did not affect urea-N kinetics. Urea-N production was higher (442.2 vs. 334.3 g of N/d), and urea-N entering the GIT tended to be higher (272.9 vs. 202.0 g of N/d), in cows fed dry-rolled barley compared with those fed pelleted barley. The amount of urea-N entry into the GIT that was returned to the ornithine cycle was higher (204.1 vs. 159.5 g of N/d) in cows fed dry-rolled barley than in pelleted barley-fed cows. The amount of urea-N recycled to the GIT and used for anabolic purposes, and the amounts lost in the urine or feces were not affected by dietary treatment. Microbial nonammonia N supply, estimated using total urinary excretion of purine derivatives, was not affected by diet. These results show that even though barley grain processing altered urea

  5. Spectroscopic Investigation of Nitrogen Loaded ECR Plasmas

    CERN Document Server

    Ullmann, F; Zschornack, G; Küchler, D; Ovsyannikov, V P

    1999-01-01

    Energy dispersive X-ray spectroscopy on ions in the plasma and magnetic q/A-analysis of the extracted ions were used to determine the plasmaproperties of nitrogen loaded ECR plasmas.As the beam expands from a limited plasma region and the ion extraction process alters the plasma properties in the extraction meniscus thebeam composition does not correspond to the bulk plasma composition. The analysis of measured spectra of characteristic X-rays delivers a method to determine the ion charge state distribution and the electron energy distribution inside the plasma and does not alter the plasma anddoes not depend on the extraction and transmission properties of the ion extraction and transport system. Hence this method seems to be moreaccurate than the traditional magnetic analysis and allows to analyse different plasma regions.A comparison between ion charge state distributions determined from X-ray spectra and such from q/A-analysis shows significant differencesfor the mean ion charge states in the source plasm...

  6. Urea metabolism in cattle and buffaloes fed diets containing NPN salts, usin g urea radiotracers

    International Nuclear Information System (INIS)

    Dhiman, T.R.; Arora, S.P.

    1990-01-01

    Urea metabolism studies were conducted using isotope dilution techniques. Animals in groups 1 and 3 were fed basal diet (S, 0.11%) supplemented with urea (test diet 1) and those of groups 2 and 4 supplemented urea plus ammonium sulphate (test diet 2) containing 0.22% S. A single injection of a mixture of 15 N-urea and 14 C-urea was given intravenously and 51 Cr-EDTA was given as a single infusion intraruminally. The pattern of release of ammonia, mean ruminal ammonia, plasma urea, rumen fluid outflow rate, rumen ammonia pool size and ammonia outflow from rumen remained unaffected due to different dietary treatments. On an average, 73.3% of plasma urea synthesized was excreted in urine with test diet 1 and showing 26.6% degradation in the gastrointestinal tract, whereas 68.8% was excreted with test diet 2 and showing 31.3% degradation in the gastrointestinal tract. At 24 hr, 18.33 to 20.93% of nitrogen entering the ruminal ammonia pool was derived from plasma urea in calves of groups 1 and 2 and 24.22 to 27.49 in buffalo calves of groups 3 and 4 respectively. Sulphur supplementation through ammonium sulphate (N : S, 10 :1) resulted in better utilization of nitrogen with test diet 2 by lowering urea excretion rate and increasing urea recycling rate in both the species. (author). 5 tabs., 16 refs

  7. Study of the effects of proline, phenylalanine, and urea foliar application to Tempranillo vineyards on grape amino acid content. Comparison with commercial nitrogen fertilisers.

    Science.gov (United States)

    Garde-Cerdán, T; López, R; Portu, J; González-Arenzana, L; López-Alfaro, I; Santamaría, P

    2014-11-15

    The aim of this work was to study the influence of foliar application of different nitrogen sources on grape amino acid content. The nitrogen sources applied to Tempranillo grapevines were proline, phenylalanine, urea, and two commercial nitrogen fertilisers, both without and with amino acids in their formulations. All treatments were applied at veraison and one week later. Proline treatment did not affect the must nitrogen composition. However, phenylalanine and urea foliar application enhanced the plants' synthesis of most of the amino acids, producing similar effects. In addition, the spray of commercial nitrogen fertilisers over leaves also induced a rise in grape amino acid concentrations regardless of the presence or absence of amino acids in their formulation. The most effective treatments were phenylalanine and urea followed by nitrogen fertilisers. This finding is of oenological interest for improved must nitrogen composition, ensuring better fermentation kinetics and most likely enhancing wine quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Plasma-enabled sensing of urea and related amides on polyaniline

    Czech Academy of Sciences Publication Activity Database

    Puliyalil, H.; Slobodian, P.; Sedlacik, M.; Benlikaya, R.; Říha, Pavel; Ostrikov, K.; Cvelbar, U.

    2016-01-01

    Roč. 10, č. 2 (2016), s. 265-272 ISSN 2095-0179 Grant - others:Ministerstvo školství, mládeže a tělovýchovy (MŠMT)(CZ) LO1504 Institutional support: RVO:67985874 Keywords : gas sensing * urea * PANI * amides * plasma Subject RIV: BK - Fluid Dynamics Impact factor: 1.712, year: 2016

  9. High-Density Lipoprotein Cholesterol, Blood Urea Nitrogen, and Serum Creatinine Can Predict Severe Acute Pancreatitis.

    Science.gov (United States)

    Hong, Wandong; Lin, Suhan; Zippi, Maddalena; Geng, Wujun; Stock, Simon; Zimmer, Vincent; Xu, Chunfang; Zhou, Mengtao

    2017-01-01

    Early prediction of disease severity of acute pancreatitis (AP) would be helpful for triaging patients to the appropriate level of care and intervention. The aim of the study was to develop a model able to predict Severe Acute Pancreatitis (SAP). A total of 647 patients with AP were enrolled. The demographic data, hematocrit, High-Density Lipoprotein Cholesterol (HDL-C) determinant at time of admission, Blood Urea Nitrogen (BUN), and serum creatinine (Scr) determinant at time of admission and 24 hrs after hospitalization were collected and analyzed statistically. Multivariate logistic regression indicated that HDL-C at admission and BUN and Scr at 24 hours (hrs) were independently associated with SAP. A logistic regression function (LR model) was developed to predict SAP as follows: -2.25-0.06 HDL-C (mg/dl) at admission + 0.06 BUN (mg/dl) at 24 hours + 0.66 Scr (mg/dl) at 24 hours. The optimism-corrected c-index for LR model was 0.832 after bootstrap validation. The area under the receiver operating characteristic curve for LR model for the prediction of SAP was 0.84. The LR model consists of HDL-C at admission and BUN and Scr at 24 hours, representing an additional tool to stratify patients at risk of SAP.

  10. Study on the relationship between milk urea nitrogen (MUN) and fertility in dairy cattle houses in Tabriz

    OpenAIRE

    S Mosaferi; S Ettehad; H Kooshavar

    2011-01-01

    The aim of this study was to assess the relationship between milk urea nitrogen (MUN) level and reproductive performance in high yielding dairy cattle houses in Tabriz, Iran. Among 213 selected dairy cattle, 76 heads (35.7%) have MUN 16 mg/dl (mean = 17.46 mg/dl). Our results indicated that MUN level in 81 heads of dairy cattle (total 124 heads) with mastitis, dystocia, laminitis, uterine infections or placenta replacement was...

  11. ASSOCIATIVE EFFECT OF MOLASSES-UREA BLOCK AND FORAGE QUALITY ON NUTRIENT DIGESTION AND NITROGEN RETENTION IN SHEEP

    Directory of Open Access Journals (Sweden)

    lqbal Saeed. M. M. Siddiqui and G. I. Habib

    2002-01-01

    Full Text Available A study was conducted in a 4x4 Latin square design involving four adult crossbred (Kaghani x Rambouillet weather kept in individual metabolic crates and four experimental diets viz: maize stovers (Diet A, maize stovers with 150 g/d molasses-urea block (Diet B, lucerne hay (Diet Cand lucerne hay with 150 g/d molasses-urea block (Diet D. The forage intake was restricted to 2% of body weight. Each experimental period consisted 10 days of adaptation followed by five days of data collection. Total dry matter intake on molasses-urea block (MUB supplemented diets was higher (p<0.05 than unsupplemented diets. The daily quantity of total dry matter and water consumed by weathers was higher (p < 0.001 on MUB supplemented diets. Water consumption was positively co-related to nitrogen intake (r2 0.66: p< 0.00 I and varied due to diets (p < 0.00 I. in vivo dry matter digestibility (DMD and organic matter digestibility (OMD of lucerne hay-based diets were greater (P< 005 than those containing maize stovers. Supplementation of MUB did not affect the DMD or OMD of the diets. The interaction of MUB and forage (P = 0.06 revealed that MUB was effective in increasing (P< 0.05 the nitrogen digestibility of maize stovers from 30,59% on diet A to 51.33% on diet B but did not affect the nitrogen digestibility in animals fed lucerne hay. The wethers receiving lucerne hay-based diets retained more nitrogen (p< 0.001 than those given maize stovers (8.50 's 3,12 g/d. Molasses-urea block supplementation on both forages increased (p < 0.05 the nitrogen retention. Mean nitrogen retention was I 82. 4.41, 7 .19 and 9.82 gld in wethers receiving diets A. B. C and D. respectively. Mean rumen ammonia concentration (mg N/lOO ml in wethers receiving maize stovers. was 10.52. which increased (p< 0,05 to 17.87 in response to MUB supplementation. On lucerne hay. the rumen ammonia concentrations did not change due to MUB and the mean values on diets C and D were 24,24 and 29.88 mg N/100

  12. Studies on the transportation of urea nitrogen from the intestines into the stomachs of dairy cows

    International Nuclear Information System (INIS)

    Voigt, J.; Piatkowski, B.

    1984-01-01

    In two experiments with dairy cow each the utilization of urea-N after its ruminal or duodenal infusion was comparatively investigated on two crude protein levels and different urease activities in the rumen. The rations contained 9.6 and 14.3 g, resp., crude plant protein/100g dry matter. After completed adaptation 50 g urea were daily infused in the rumen in 3 h and the duodenum in 6 h, resp., with the morning and evening feeding. In the duodenal experiment the urease blocker phosphoric acid phenylester diamide (PPD) was applied in an additional experiment synchronously with the duodenal urea application. On the first measuring day in each case the urea in the morning feeding was labelled with 17.4 atom-% 15 N excess. After ruminal infusion there always were higher NH 3 concentrations in the rumen and 15 N frequencies in the rumen proteins, resp.. One can conclude that urea-N that gets into the intestines is to a lower degree used for duodenal protein supply than directly utilisable urea-N from the ration in the rumen. The difference increases with the protein content of the ration and the inhibition of rumen urease. The urea-N balance is to a considerably smaller degree influenced by the place of urea infusion particularly at a low level of N supply, which is due to a better utilization of the urea-N transported with intermediary metabolism from the intestines. (author)

  13. Studies on the transportation of urea nitrogen from the intestines into the stomachs of dairy cows

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, J; Piatkowski, B [Akademie der Landwirtschaftswissenschaften der DDR, Dummerstorf-Rostock. Forschungszentrum fuer Tierproduktion

    1984-11-01

    In two experiments with dairy cow each the utilization of urea-N after its ruminal or duodenal infusion was comparatively investigated on two crude protein levels and different urease activities in the rumen. The rations contained 9.6 and 14.3 g, resp., crude plant protein/100g dry matter. After completed adaptation 50 g urea were daily infused in the rumen in 3 h and the duodenum in 6 h, resp., with the morning and evening feeding. In the duodenal experiment the urease blocker phosphoric acid phenylester diamide (PPD) was applied in an additional experiment synchronously with the duodenal urea application. On the first measuring day in each case the urea in the morning feeding was labelled with 17.4 atom-% /sup 15/N excess. After ruminal infusion there always were higher NH/sub 3/ concentrations in the rumen and /sup 15/N frequencies in the rumen proteins, resp.. One can conclude that urea-N that gets into the intestines is to a lower degree used for duodenal protein supply than directly utilisable urea-N from the ration in the rumen. The difference increases with the protein content of the ration and the inhibition of rumen urease. The urea-N balance is to a considerably smaller degree influenced by the place of urea infusion particularly at a low level of N supply, which is due to a better utilization of the urea-N transported with intermediary metabolism from the intestines.

  14. Sodium phenylbutyrate decreases plasma branched-chain amino acids in patients with urea cycle disorders.

    Science.gov (United States)

    Burrage, Lindsay C; Jain, Mahim; Gandolfo, Laura; Lee, Brendan H; Nagamani, Sandesh C S

    2014-01-01

    Sodium phenylbutyrate (NaPBA) is a commonly used medication for the treatment of patients with urea cycle disorders (UCDs). Previous reports involving small numbers of patients with UCDs have shown that NaPBA treatment can result in lower plasma levels of the branched-chain amino acids (BCAA) but this has not been studied systematically. From a large cohort of patients (n=553) with UCDs enrolled in the Longitudinal Study of Urea Cycle Disorders, a collaborative multicenter study of the Urea Cycle Disorders Consortium, we evaluated whether treatment with NaPBA leads to a decrease in plasma BCAA levels. Our analysis shows that NaPBA use independently affects the plasma BCAA levels even after accounting for multiple confounding covariates. Moreover, NaPBA use increases the risk for BCAA deficiency. This effect of NaPBA seems specific to plasma BCAA levels, as levels of other essential amino acids are not altered by its use. Our study, in an unselected population of UCD subjects, is the largest to analyze the effects of NaPBA on BCAA metabolism and potentially has significant clinical implications. Our results indicate that plasma BCAA levels should to be monitored in patients treated with NaPBA since patients taking the medication are at increased risk for BCAA deficiency. On a broader scale, these findings could open avenues to explore NaPBA as a therapy in maple syrup urine disease and other common complex disorders with dysregulation of BCAA metabolism. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Cow and herd variation in milk urea nitrogen concentrations in lactating dairy cattle.

    Science.gov (United States)

    Aguilar, M; Hanigan, M D; Tucker, H A; Jones, B L; Garbade, S K; McGilliard, M L; Stallings, C C; Knowlton, K F; James, R E

    2012-12-01

    Milk urea nitrogen (MUN) is correlated with N balance, N intake, and dietary N content, and thus is a good indicator of proper feeding management with respect to protein. It is commonly used to monitor feeding programs to achieve environmental goals; however, genetic diversity also exists among cows. It was hypothesized that phenotypic diversity among cows could bias feed management decisions when monitoring tools do not consider genetic diversity associated with MUN. The objective of the work was to evaluate the effect of cow and herd variation on MUN. Data from 2 previously published research trials and a field trial were subjected to multivariate regression analyses using a mixed model. Analyses of the research trial data showed that MUN concentrations could be predicted equally well from diet composition, milk yield, and milk components regardless of whether dry matter intake was included in the regression model. This indicated that cow and herd variation could be accurately estimated from field trial data when feed intake was not known. Milk urea N was correlated with dietary protein and neutral detergent fiber content, milk yield, milk protein content, and days in milk for both data sets. Cow was a highly significant determinant of MUN regardless of the data set used, and herd trended to significance for the field trial data. When all other variables were held constant, a percentage unit change in dietary protein concentration resulted in a 1.1mg/dL change in MUN. Least squares means estimates of MUN concentrations across herds ranged from a low of 13.6 mg/dL to a high of 17.3 mg/dL. If the observed MUN for the high herd were caused solely by high crude protein feeding, then the herd would have to reduce dietary protein to a concentration of 12.8% of dry matter to achieve a MUN concentration of 12 mg/dL, likely resulting in lost milk production. If the observed phenotypic variation is due to genetic differences among cows, genetic choices could result in

  16. Impact of controlled release urea on maize yield and nitrogen use efficiency under different water conditions.

    Directory of Open Access Journals (Sweden)

    Guanghao Li

    Full Text Available Controlled release urea (CRU has been widely adopted to increase nitrogen (N use efficiency and maize production, but the impacts can range widely depending on water availability in the soil. In an experiment using Zhengdan 958 (a popular summer maize hybrid, three levels of water treatments (adequate water condition [W3], which maintained soil moisture at about 75% ± 5% of the soil's field capacity; mild water stress [W2], which maintained moisture content at 55% ± 5% of field capacity; and severe water stress [W1], which had a moisture content of 35% ± 5% of field capacity and four levels of controlled release urea fertilizer (N0, N1, N2 and N3 were 0, 105, 210 and 315 kg N ha-1, respectively were compared in a rainout shelter system with soil. The results revealed that CRU had significant effects on maize yields and N use efficiencies under different water conditions. The mean yields increased with increasing water levels and showed significant differences. Under W1, the accumulation of dry matter and N were limited, and N internal efficiency (NIE and the apparent recovery efficiency of applied N (REN decreased with N increases; yields of N1, N2, and N3 were similar. Under W2, the dry matter and N accumulation, as well as the yield, showed an increasing trend with an increase in N application, and the NIE and REN of N3 showed no difference from N2. Under W3, yields of N2 and N3 were similar and they were significantly higher than that of N1, but the agronomic N use efficiency (ANUE, REN, and the physiological NUE (PNUE of N2 were 54.2, 34.9, and 14.4% higher, respectively, than those of N3. N application beyond the optimal N rate did not consistently increase maize yield, and caused a decrease in N use efficiencies. Highest overall dry matter, N accumulation, and yields were observed with N3 under W2, and those showed no differences with N2 and N3 under W3. Under this experimental condition, the CRU of 210 kg ha-1 was optimized when soil

  17. Effects of Nitrification Inhibitors and Sulphur Coated Urea(SCU on Different Nitrogen Sources and Wheat Yield

    Directory of Open Access Journals (Sweden)

    LI Yong-qiang

    2016-05-01

    Full Text Available Nitrogen is essential for plant growth and health, and it is also a limiting factor for the growth in most agricultural systems. Intensive N fertilizer application has become the traditional habit for agricultural producers in China because of its importance to plant productivity and agricultural land profitability. But some problems have appeared with the increase of the amount of nitrogen fertilizer applied, urea used in crops is easy to lose from volatilization or leaching. Therefore, current crop management practices lead to a highly nitrifying soil environments. Nitrogen emission is the main source of soil acidity and environmental pollution. Several methods for the use of slow controlled release urea have been reported to be used to control the pollution and to enhance nitrogen use efficiency. There is a growing interest in the formulations of coated chemical fertilizers with both urease inhibitor and nitrification inhibitor. Urease inhibitor and nitrification inhibitor may improve urea N-use efficiency and minimize N losses by gaseous emissions of ammonia(NH3 to the atmosphere and nitrate(NO3- leaching into the surface and ground water. Dicyandiamide(DCD is a nitrification inhibitor that has been studied for many years, it can effectively inhibit nitrification and N2O emission in many agricultural ecosystems. However, limited information is available on the use of the combination of nitrification inhibitor and urease inhibitor applied with urea fertilizer, especially for thiourea(THU and thiourea formaldehyde resin(TFR applications. Therefore the purpose of this study is to investigate the effect of urea with different inhibitors to improve the efficiency of nitrogen utilization. A field pot experiment was conducted to explore how to increase the concentration of DCD/THU/TFR/sulfur-coated urea(SCU to affect the transformation of soil nitrogen and wheat yield. The experiment was designed for twelve treatments which included no nitrogen

  18. Comparison of nitrogen utilization and urea kinetics between yaks (Bos grunniens) and indigenous cattle (Bos taurus).

    Science.gov (United States)

    Zhou, J W; Zhong, C L; Liu, H; Degen, A A; Titgemeyer, E C; Ding, L M; Shang, Z H; Guo, X S; Qiu, Q; Li, Z P; Yang, G; Long, R J

    2017-10-01

    Under traditional management on the Qinghai-Tibetan Plateau, yaks () graze only on natural pasture without supplements and are forced to cope with sparse forage of low N content, especially in winter. In contrast, indigenous Tibetan yellow cattle () require supplements during the cold season. We hypothesized that, in response to harsh conditions, yaks cope with low N intakes better than cattle. To test this hypothesis, a study of whole-body N retention and urea kinetics was conducted in 2 concurrent 4 × 4 Latin squares, with 1 square using yaks and 1 square using cattle. Four isocaloric forage-concentrate diets differing in N concentrations (10.3, 19.5, 28.5, and 37.6 g N/kg DM) were formulated, and by design, DMI were similar between species and across diets. Urea kinetics were determined with continuous intravenous infusion of NN urea for 104 h, and total urine and feces were concomitantly collected. Urea production, urea recycling to the gut, and ruminal microbial protein synthesis all linearly increased ( Urea production was greater in yaks than in cattle at the 3 lowest N diets but greater in cattle than in yaks at the highest N diet (species × diet, Urea N recycled to the gut ( urea N captured by ruminal bacteria ( urea recycling was through saliva, with no difference between species ( = 0.61). Glomerular filtration rate was lower ( = 0.05) in yaks than in cattle. The higher urea recycling and greater capture of recycled urea by ruminal microbes in yaks than in cattle suggest that yaks use mechanisms to utilize dietary N more efficiently than cattle, which may partially explain the better survival of yaks than cattle when fed low-N diets.

  19. Determinants of urea nitrogen production in sepsis. Muscle catabolism, total parenteral nutrition, and hepatic clearance of amino acids.

    Science.gov (United States)

    Pittiruti, M; Siegel, J H; Sganga, G; Coleman, B; Wiles, C E; Placko, R

    1989-03-01

    The major determinants of urea production were investigated in 26 patients with multiple trauma (300 studies). The body clearances (CLRs) of ten amino acids (AAs) were estimated as a ratio of muscle-released AAs plus total parenteral nutrition-infused AAs to their extracellular pool. While clinically septic trauma (ST) patients without multiple-organ failure syndrome (MOFS) had a higher level of urea nitrogen production (25.6 +/- 13.4 g of N per day) compared with nonseptic trauma (NST) patients (14 +/- 7.5 g of N per day) and with ST patients with MOFS (4.28 +/- 1.5 g of N per day), in all groups urea N production was found to be a function of muscle protein degradation (catabolism), total parenteral nutrition-administered AAs, and the ratio between leucine CLR and tyrosine CLR (L/T) (r2 = .82, P less than .0001). Since tyrosine is cleared almost exclusively by the liver, the L/T ratio may be regarded as an index of hepatic function. The significant differences between urea N production in ST and NST patients lay in an increased positive dependence on muscle catabolism and increased negative correlation with L/T in the ST group. At any L/T ratio, urea N production was increased in ST patients over NST patients, but in ST patients with MOFS, it fell to or below levels of NST patients. These data show that the ST process is associated with enhancement of ureagenesis, due to increased hepatic CLR of both exogenous and endogenous AAs. In sepsis with MOFS, a marked inhibition of urea synthesis occurs, partially explained by a decreased hepatic CLR of non-branched-chain AAs.

  20. Effects of nitrogen supply on inter-organ fluxes of urea-N and renal urea-N kinetics in lactating Holstein cows

    DEFF Research Database (Denmark)

    Røjen, Betina Amdisen; Theil, Peter Kappel; Kristensen, Niels Bastian

    2011-01-01

    The effects of decreasing ruminal urea infusion in lactating dairy cows fed a basal diet deficient in rumen degradable protein on inter-organ urea-N fluxes, epithelial urea-N extraction, and renal urea-N kinetics were investigated. Eight Danish Holstein cows fitted with a ruminal cannula...... and permanent indwelling catheters in the major splanchnic blood vessels and the gastrosplenic vein were used. The cows were randomly allocated to a triplicate incomplete 3 × 3 Latin square design with 14-d periods. Treatments were continuous ventral ruminal infusion of water, 4.1 g of feed urea/kg of dry...... matter intake, and 8.5 g of feed urea/kg of dry matter intake. Dry matter intake and milk yield decreased linearly with decreasing urea infusion. Arterial blood urea-N and ruminal ammonia concentrations decreased linearly with decreasing urea infusion. In absolute amounts, the urea-N recycling did...

  1. Influence of exercise on plasma ammonia and urea after ingestion beverages of carbohydrate electrolyte

    Science.gov (United States)

    Rusip, Gusbakti; Mukti Suhartini, Sri; Boon Suen, Ang

    2018-03-01

    Ingestion of beverages with carbohydrate electrolyte during exercise can delay fatigue. Fatigue caused by the decreasing of glycogen deposit source and indefensible reproduced ATP result in the improvement of IMP and ammonia during fatigue. The aim of this research was to observe the alteration of plasma ammonia and urea before, during and after exercise, after ingestion beverages of carbohydrate - electrolyte. Ten male subjects (age 18-30 years) were subjected to there cycle ergometer at 60% of VO2max with a pedal speed of 60 rpm until there is fatigued. The subject was given a drink of carbohydrate-electrolyte at a concentration of 6%, 12% and a flavored water placebo (P) to consume the volume of 3 ml/kg BW every 20 minutes. Blood samples were taken at rest and every 20 minutes until fatigue for analyzing plasma ammonia and urea. Mean exercise until fatigue show that no difference for three beverages. However, plasma ammonia and urea were significantly increase compared before and after exercise (pexercise for beverages CHO 12% (HC) (31.86±1.93μml/l vs 86.50±5.13μml/l), for CHO 6% (MC) (33.08±1.43μml/l vs 90.68±3.41μml/l), for no carbohydrate (P) (33.64±1.93μml/l vs 93.12 ± 2.91μml/l). Whereas plasma urea before exercise for beverages CHO 12% (4.75±0.12mmol/l vs 5.44±0.10mmol/l), for CHO 6% (4.88±0.20mmol/l vs 5.22± 0.10mmol/l), for Placebo (4.88±0.20mmol/l vs 5.54±0.24mmol/l). Conclusions that increase of plasma ammonia of during fatigue, can become the criteria for determining intensity exercise until fatigue results are better than plasma lactate.

  2. Urea as nitrogen source for phytoplankton production in coastal waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.

    Annual variation of urea in coastal waters off Goa, India is 0 to 2.92 mu g-at N.1/1 and 0 to 4.69 mu g-at N.1/1 in adjacent estuarine waters of Mandovi. Peaks of phytoplankton production accompanied with the decrease in urea in June and October...

  3. Blood urea nitrogen/creatinine index is a predictor of prerenal damage in preeclampsia

    Directory of Open Access Journals (Sweden)

    Hidajet Paçarizi

    2012-04-01

    Full Text Available Introduction: Preeclampsia is a disease whose etiology is not very clearly explained. The aim of this study was to investigate the importance of blood urea nitrogen (BUN/creatinine ratio in diagnosing preeclampsiaand evaluating prognosis.Methods: The patients in this research were examined and diagnosed in the Department of Obstetrics and Gynecology, University Clinical Centre of Kosovo. Control group included 25 pregnant women with a normalblood pressure and with a gestational age of more than 20 weeks, whereas the investigation group included 25 women diagnosed with preeclampsia. The patients were not administered therapy four days before the examination. For the determination of biochemical parameters we used end point bichromatic enzymatic rate and enzymatic conductivity rate.Results: BUN/Creatinine index in the preeclamptic group was 19±7.7, uric acid 280±70 μmol/L, lactate dehydrogenase198±63 U/L, while the number of platelets was 195±5061 x 109/L. In control group BUN/Creatinine index was 12±3, lactate dehydrogenase was 165±57 U/L, uric acid 197±79 μmol/La and the platelet numberwas 243±61 x109/L. Albumin/Globulin index in the preeclamptic group was 0.8±0.12, whereas in the control group it was 0.9±0.16.Conclusions: BUN/Creatinine ratio in pregnant women with preeclampsia was significantly increased (t=-4.14; p=0.00013 in comparison to the control group. It indicates the prerenal source of azotemia. This indexcan be important for the evaluation of preeclampsia severity.

  4. Using Milk Urea Nitrogen to Evaluate Diet Formulation and Environmental Impact on Dairy Farms

    Directory of Open Access Journals (Sweden)

    J.S. Jonker

    2001-01-01

    Full Text Available Reducing nitrogen (N excretion by dairy cattle is the most effective means to reduce N losses (runoff, volatilization, and leaching from dairy farms. The objectives of this review are to examine the use of milk urea nitrogen (MUN to measure N excretion and utilization efficiency in lactating dairy cows and to examine impacts of overfeeding N to dairy cows in the Chesapeake Bay drainage basin. A mathematical model was developed and evaluated with an independent literature data set to integrate MUN and milk composition to predict urinary and fecal excretion, intake, and utilization efficiency for N in lactating dairy cows. This model was subsequently used to develop target MUN concentrations for lactating dairy cattle fed according to National Research Council (NRC recommendations. Target values calculated in this manner were 8 to 14 mg/dl for a typical lactation and were most sensitive to change in milk production and crude protein intake. Routine use of MUN to monitor dairy cattle diets was introduced to dairy farms (n = 1156 in the Chesapeake Bay watershed. Participating farmers (n = 454 were provided with the results of their MUN analyses and interpretive information monthly for a period of 6 months. The average MUN across all farms in the study increased in the spring, but the increase was 0.52 mg/dl lower for farmers receiving MUN results compared to those who did not participate in the program. This change indicated that participating farmers reduced N feeding compared to nonparticipants. Average efficiency of feed N utilization (N in milk / N in feed x 100 was 24.5% (SD = 4.5. On average, farmers fed 6.6% more N than recommended by the NRC, resulting in a 16% increase in urinary N and a 2.7% increase in fecal N compared to feeding to requirement. N loading to the Chesapeake Bay from overfeeding protein to lactating dairy cattle was estimated to be 7.6 million kg/year. MUN is a useful tool to measure diet adequacy and environmental impact

  5. ACUTE RENAL FAILURE WITH NORMAL PLASMA UREA LEVEL SECONDARY TO ACUTE PYELONEPHITIS IN A SINGLE KIDNEY PATIENT

    Directory of Open Access Journals (Sweden)

    Imperiali N

    2006-03-01

    Full Text Available SUMMARYAcute renal failure is a syndrome that usually runs with an increase in creatinine and urea plasma levels. However, there are clinical situations in which this syndrome may run with an increase in plasma creatinine keeping normal the urea one.In this report we present a case of acute renal failure with normal plasma urea level secondary to an acute pyelonephritis in a single kidney patient. The patient had an increased fractional excretion of urea which could explain the normal plasma urea levels found despite of his reduced glomerular filtration. This increased urea excretion state was interpreted as a consequence of the nephrogenic diabetes insipidus and alteration of the intra-renal urea reciclying process that the acute pyelonephritis induced. In conclusion: Acute pyelonephritis in a single kidney patient can appear as a pattern of acute renal failure with normal plasma urea levels. RESUMEN:La insuficiencia renal aguda es un sindrome que característicamente cursa con niveles plasmáticos elevados de urea y creatinina. Sin embargo, hay situaciones clínicas en las cuales este sindrome puede cursar con un incremento de la creatininemia sin presentar elevación de la uremia.En este reporte presentamos un caso clínico de una insuficiencia renal aguda con uremia normal secundaria a una pielonefritis aguda en un paciente con riñón único. El paciente presentaba una elevada excreción fraccional de urea lo cual podía explicar su uremia normal pese a estar cursando una caída del filtrado gomerular. Dicha excreción de urea elevada fue interpretada como secundaria a una diabetes insipida nefrogénica y una alteración en el recirculado intra-renal de la urea ambos producto de la pielonefritis aguda. Concluimos que la pielonefritis aguda en un paciente mono-reno puede presentarse con un patrón de insuficiencia renal aguda con uremia normal.

  6. ACUTE RENAL FAILURE WITH NORMAL PLASMA UREA LEVEL SECONDARY TO ACUTE PYELONEPHITIS IN A SINGLE KIDNEY PATIENT

    Directory of Open Access Journals (Sweden)

    Algranati L

    2007-04-01

    Full Text Available SUMMARY: Acute renal failure is a syndrome that usually runs with an increase in creatinine and urea plasma levels. However, there are clinical situations in which this syndrome may run with an increase in plasma creatinine keeping normal the urea one. In this report we present a case of acute renal failure with normal plasma urea level secondary to an acute pyelonephritis in a single kidney patient. The patient had an increased fractional excretion of urea which could explain the normal plasma urea levels found despite of his reduced glomerular filtration. This increased urea excretion state was interpreted as a consequence of the nephrogenic diabetes insipidus and alteration of the intra-renal urea reciclying process that the acute pyelonephritis induced. In conclusion: Acute pyelonephritis in a single kidney patient can appear as a pattern of acute renal failure with normal plasma urea levels.RESUMEN: La insuficiencia renal aguda es un sindrome que característicamente cursa con niveles plasmáticos elevados de urea y creatinina. Sin embargo, hay situaciones clínicas en las cuales este sindrome puede cursar con un incremento de la creatininemia sin presentar elevación de la uremia. En este reporte presentamos un caso clínico de una insuficiencia renal aguda con uremia normal secundaria a una pielonefritis aguda en un paciente con riñón único. El paciente presentaba una elevada excreción fraccional de urea lo cual podía explicar su uremia normal pese a estar cursando una caída del filtrado gomerular. Dicha excreción de urea elevada fue interpretada como secundaria a una diabetes insipida nefrogénica y una alteración en el recirculado intra-renal de la urea ambos producto de la pielonefritis aguda. Concluimos que la pielonefritis aguda en un paciente mono-reno puede presentarse con un patrón de insuficiencia renal aguda con uremia normal.

  7. Stimulation effect of synthetic cytokinins on the uptake and incorporation of nitrogen-15-labelled ammonium nitrate and urea in wheat leaves

    International Nuclear Information System (INIS)

    Iglewski, S.M.; Szarvas, T.; Pozsar, B.I.

    1977-01-01

    The turnover of different labelled nitrogen sources in wheat leaves has been investigated using the isotopic tracer technique. The 15 N at.% was determined in free ammonium ion, in the nitrate and the nitrite levels, and also in the non-disintegrated urea. The accumulation and the incorporation of stable nitrogen was measured in the TCA insoluble protein fraction. According to the experimental data the intensity of incorporation of urea nitrogen is relatively higher than that of the different inorganic compounds. The utilization of ammonium ion was 76% compared with the urea, whereas that of the nitrate nitrogen was 60% in the wheat leaves. The incorporation rate of the two nitrogen atoms from ammonium nitrate was 32% lower than that of the urea nitrogen, in the leaf protein of Bezostaia-1 wheat variety. The turnover of urea through the transamination was very rapid, the amination with ammonium ion was slower, and the first phase of the nitrate reduction was relatively more retarded than the nitrite reduction. The endogenous cytokinin-like biological activity and some synthetic cytokinins (kinetin, benzyladenine) have a remarkably stimulating effect on the incorporation of the different 15 N-labelled nitrogen sources into the leaf protein fraction. (author)

  8. Amino substituted nitrogen heterocycle ureas as kinase insert domain containing receptor (KDR inhibitors: Performance of structure–activity relationship approaches

    Directory of Open Access Journals (Sweden)

    Hayriye Yilmaz

    2015-06-01

    Full Text Available A quantitative structure–activity relationship (QSAR study was performed on a set of amino-substituted nitrogen heterocyclic urea derivatives. Two novel approaches were applied: (1 the simplified molecular input-line entry systems (SMILES based optimal descriptors approach; and (2 the fragment-based simplex representation of molecular structure (SiRMS approach. Comparison with the classic scheme of building up the model and balance of correlation (BC for optimal descriptors approach shows that the BC scheme provides more robust predictions than the classic scheme for the considered pIC50 of the heterocyclic urea derivatives. Comparison of the SMILES-based optimal descriptors and SiRMS approaches has confirmed good performance of both techniques in prediction of kinase insert domain containing receptor (KDR inhibitory activity, expressed as a logarithm of inhibitory concentration (pIC50 of studied compounds.

  9. Utilization of urea/molasses liquid feed as a major source of nitrogen and energy for lactating cows

    International Nuclear Information System (INIS)

    Ranjhan, S.K.; Krishna Mohan, D.V.G.; Pathak, N.N.

    1976-01-01

    Experiments were conducted in which urea/molasses liquid feed along with a limited amount of intact protein and cereal forage was fed to lactating cows, and compared with another group receiving conventional concentrate and roughage-based rations. Voluntary consumption of liquid feed by cows was satisfactory. There was no significant difference in the milk yield between the two groups. The higher consumption of metabolizable energy and digestible crude protein by experimental cows from liquid feed was not reflected in their milk yields or body weights. Various other parameters such as digestibilities of nutrients, efficiency of energy and nitrogen utilization for milk production and N-balance have been presented in cows fed urea/molasses liquid diets and conventional diets. (author)

  10. [Effects of controlled release blend bulk urea on soil nitrogen and soil enzyme activity in wheat and rice fields].

    Science.gov (United States)

    Zhang, Jing Sheng; Wang, Chang Quan; Li, Bing; Liang, Jing Yue; He, Jie; Xiang, Hao; Yin, Bin; Luo, Jing

    2017-06-18

    A field experiment was conducted to investigate the effect of controlled-release fertilizer (CRF) combined with urea (UR) on the soil fertility and environment in wheat-rice rotation system. Changes in four forms of nitrogen (total nitrogen, ammonium nitrogen, nitrate nitrogen, and microbial biomass nitrogen) and in activities of three soil enzymes participating in nitrogen transformation (urease, protease, and nitrate reductase) were measured in seven fertilization treatments (no fertilization, routine fertilization, 10%CRF+90%UR, 20%CRF+80%UR, 40%CRF+60%UR, 80%CRF+20%UR, and 100%CRF). The results showed that soil total nitrogen was stable in the whole growth period of wheat and rice. There was no significant difference among the treatments of over 20% CRF in soil total nitrogen content of wheat and rice. The soil inorganic nitrogen content was increased dramatically in treatments of 40% or above CRF during the mid-late growing stages of wheat and rice. With the advance of the growth period, conventional fertilization significantly decreased soil microbial biomass nitrogen, but the treatments of 40% and above CRF increased the soil microbial biomass nitrogen significantly. The soil enzyme activities were increased with over 40% of CRF in the mid-late growing stage of wheat and rice. By increasing the CRF ratio, the soil protease activity and nitrate reductase activity were improved gradually, and peaked in 100% CRF. The treatments of above 20% CRF could decrease the urease activity in tillering stage of rice and delay the peak of ammonium nitrogen, which would benefit nitrogen loss reduction. The treatments of 40% and above CRF were beneficial to improving soil nitrogen supply and enhancing soil urease and protease activities, which could promote the effectiveness of nitrogen during the later growth stages of wheat and rice. The 100% CRF treatment improved the nitrate reductase activity significantly during the later stage of wheat and rice. Compared with the

  11. Mineralization and volatilization of nitrogen from vinasse-15 N in the presence or absence of urea and sugar cane straw

    International Nuclear Information System (INIS)

    Silva, Vilma Maria; Colaco, Waldeciro; Encarnacao, Fernando Antonio Franco da; Cabezas, Waldo Alejandro Ruben Lara

    1999-01-01

    The mineralized and volatilized nitrogen derived from vinasse labelled with 15 N were determined in a laboratory experiment, using samples of two soils [a sandy Red-Yellow-Podzolic-PV and a clayey Latosol - LR (Oxisol)], collected in Piracicaba, SP, Brazil. The experiment consisted of four treatments: application of vinasse (V * ); vinasse with urea (V * +U); vinasse with sugar cane straw (V * +P); and vinasse with urea and sugar cane straw (V * +U+P). Vinasse, labelled with 15 N (V * ) was applied at a rate of 100 mg.kg -1 of N-vinasse. All treatments, were incubated for 7, 14, 21, 28 and 35 days. N-urea and sugar cane straw were incorporated in the soil at rates of 220 mg.kg -1 and 22 g.kg -1 , respectively. N H 4 + -N and NO 3 - -N concentrations, as a result of the vinasse addition, were affected by soil type. A larger availability of N H 4 + -N and NO 3 - -N derived from vinasse were observed, when urea was added. Sugar cane straw plus vinasse did not alter the concentrations of N H 4 + - N and NO 3 - - N derived from vinasse. Urea plus sugar cane straw did not affect N H 4 + -N concentrations, and affected the NO 3 - -N concentration in LR soil over time. Losses of vinasse-N, due to volatilization, increased with time for all treatments, and were larger for PV (14%) than for LR(5%); but such losses were similar in LR soil. (author)

  12. Residual effect of sugar cane ratoon of urea nitrogen foliar application to plant cane

    International Nuclear Information System (INIS)

    Trivelin, P.C.O.; Lara Cabezas, W.A.R.; Coleti, J.T.

    1984-01-01

    The residual effect of urea - N, foliar applied to plant cane, on sugar cane ratoon is studied. Setts grown in drums containing washed sand are used. 180 days from planting, foliar fertilizer (43.5% urea solution) labelled with 3.95 atom % 15 N is applied. The first harvest is made 7 days after application and final harvest of resprouting at 123 days. (M.A.C.) [pt

  13. Population pharmacokinetic modeling and dosing simulations of nitrogen-scavenging compounds: disposition of glycerol phenylbutyrate and sodium phenylbutyrate in adult and pediatric patients with urea cycle disorders.

    Science.gov (United States)

    Monteleone, Jon P R; Mokhtarani, M; Diaz, G A; Rhead, W; Lichter-Konecki, U; Berry, S A; Lemons, C; Dickinson, K; Coakley, D; Lee, B; Scharschmidt, B F

    2013-07-01

    Sodium phenylbutyrate and glycerol phenylbutyrate mediate waste nitrogen excretion in the form of urinary phenylacetylglutamine (PAGN) in patients with urea cycle disorders (UCDs); rare genetic disorders characterized by impaired urea synthesis and hyperammonemia. Sodium phenylbutyrate is approved for UCD treatment; the development of glycerol phenylbutyrate afforded the opportunity to characterize the pharmacokinetics (PK) of both compounds. A population PK model was developed using data from four Phase II/III trials that collectively enrolled patients ages 2 months to 72 years. Dose simulations were performed with particular attention to phenylacetic acid (PAA), which has been associated with adverse events in non-UCD populations. The final model described metabolite levels in plasma and urine for both drugs and was characterized by (a) partial presystemic metabolism of phenylbutyric acid (PBA) to PAA and/or PAGN, (b) slower PBA absorption and greater presystemic conversion with glycerol phenylbutyrate, (c) similar systemic disposition with saturable conversion of PAA to PAGN for both drugs, and (d) body surface area (BSA) as a significant covariate accounting for age-related PK differences. Dose simulations demonstrated similar PAA exposure following mole-equivalent PBA dosing of both drugs and greater PAA exposure in younger patients based on BSA. © The Author(s) 2013.

  14. Polymer Coated Urea in Turfgrass Maintains Vigor and Mitigates Nitrogen's Environmental Impacts.

    Directory of Open Access Journals (Sweden)

    Joshua J LeMonte

    Full Text Available Polymer coated urea (PCU is a N fertilizer which, when added to moist soil, uses temperature-controlled diffusion to regulate N release in matching plant demand and mitigate environmental losses. Uncoated urea and PCU were compared for their effects on gaseous (N2O and NH3 and aqueous (NO3(- N environmental losses in cool season turfgrass over the entire PCU N-release period. Field studies were conducted on established turfgrass sites with mixtures of Kentucky bluegrass (Poa pratensis L. and perennial ryegrass (Lolium perenne L. in sand and loam soils. Each study compared 0 kg N ha(-1 (control to 200 kg N ha(-1 applied as either urea or PCU (Duration 45CR®. Application of urea resulted in 127-476% more evolution of measured N2O into the atmosphere, whereas PCU was similar to background emission levels from the control. Compared to urea, PCU reduced NH3 emissions by 41-49% and N2O emissions by 45-73%, while improving growth and verdure compared to the control. Differences in leachate NO3(- among urea, PCU and control were inconclusive. This improvement in N management to ameliorate atmospheric losses of N using PCU will contribute to conserving natural resources and mitigating environmental impacts of N fertilization in turfgrass.

  15. Nitrogen balance and milk composition of dairy cows fed urea and soybean meal and two protein levels using sugar cane based diets

    Directory of Open Access Journals (Sweden)

    Luís Henrique Andreucci Conti

    2014-12-01

    Full Text Available The aim of the study was to evaluate the effect of feeding two levels of crude protein (CP (low: 142 g CP/kg DM; and high: 156 g CP/kg DM and two nitrogen sources (soybean meal and urea to dairy cows using sugar cane as forage on microbial protein synthesis, the composition of the milk nitrogen fraction, nitrogen (N balance and blood parameters. Twelve Holstein cows with an average milk yield of 22.0 ± 2.3 kg/day, and with 235 ± 40 days in milk were included in this study. The animals were grouped into three balanced and contemporary 4x4 Latin squares for an experimental period of 21 days. On the 15th day of each period, milk and urine samples were collected for microbial protein synthesis determination. Total excretion of urine (L/day, milk urea nitrogen (MUN and blood urea were higher for the diets with high CP, regardless of the nitrogen source. Nitrogen efficiency was higher for cows fed diets with low CP. Cows in the final third of lactation can be fed diets with reduced CP levels, regardless of the nitrogen source, soybean meal or urea, without influencing the synthesis of microbial protein or the composition of the nitrogen fraction of milk.

  16. Thermal equilibrium criteria in a nitrogen plasma

    International Nuclear Information System (INIS)

    Cilliers, W.A.; Hey, J.D.; Rash, J.P.S.

    1975-01-01

    A method for obtaining the lower electron density limit for LTE in a nitrogen plasma is described, whereby the experimentally determined ratio of the collisional-radiative ionization and recombination coefficients (S/α) is compared with the corresponding LTE value (Saha ratio). It is argued that if the electron density is increased from values of about 10 16 cm -3 , S/α should tend to the Saha ratio as LTE is approached For NII and NIII spectral lines, this is found to happen at an electron density of a few times 10 16 cm -3 when the electron temperature is about 3 eV, in good agreement with the LTE criterion of Griem. (author)

  17. Effect of delayed wrapping and wrapping source on nitrogen balance and blood urea nitrogen in gestating sheep offered alfalfa silage

    Science.gov (United States)

    Exposing ensiled forage to oxygen can result in DM deterioration and reduce silage intake by animals. This study was conducted to investigate the effects of 2 different wrapping sources and time intervals between baling and wrapping on N balance and blood urea N in gestating sheep offered alfalfa si...

  18. The effect of percentage of nitrogen in plasma gas on nitrogen

    African Journals Online (AJOL)

    user

    1985-09-01

    Sep 1, 1985 ... an arc plasma into liquid iron has been investigated by melting iron in an atmosphere of nitrogen and argon using an arc plasma. Results show that both the rate of ..... "Solubility of Nitrogen in arc melted and Levitation-melted.

  19. Methanol electrocatalytic oxidation on Pt nanoparticles on nitrogen doped graphene prepared by the hydrothermal reaction of graphene oxide with urea

    International Nuclear Information System (INIS)

    Xu, Xiao; Zhou, Yingke; Yuan, Tao; Li, Yawei

    2013-01-01

    A facile hydrothermal reaction of graphene oxide with urea was used to produce nitrogen doped graphene, and Pt nanoparticles were deposited on the obtained nitrogen doped graphene by the NaBH 4 reduction route. The morphology and microstructure of the synthesized catalysts were characterized by transmission electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy, while the functional groups on the surface of the catalysts were investigated by the Fourier transform infrared spectroscopy and ultraviolet-visible absorption spectra. Cyclic voltammetry, chronoamperometry and electrochemical impedance techniques were carried out to evaluate the methanol electrocatalytic oxidation activity and durability of Pt catalysts supported on the nitrogen doped graphene. The results showed that nitrogen doping and reduction of GO were achieved simultaneously by the facile hydrothermal reaction, which had beneficial effects for the deposition process and electrocatalytic activity of Pt nanoparticles. The Pt catalysts supported on the nitrogen doped graphene substrate presented excellent activity and durability of methanol oxidation reaction, which might be promising for application in direct methanol fuel cells

  20. Population Pharmacokinetic Modeling and Dosing Simulations of Nitrogen-Scavenging Compounds: Disposition of Glycerol Phenylbutyrate and Sodium Phenylbutyrate in Adult and Pediatric Patients with Urea Cycle Disorders

    OpenAIRE

    Monteleone, Jon P. R.; Mokhtarani, M.; Diaz, G. A.; Rhead, W.; Lichter-Konecki, U.; Berry, S. A.; LeMons, C.; Dickinson, K.; Coakley, D.; Lee, B.; Scharschmidt, B. F.

    2013-01-01

    Sodium phenylbutyrate and glycerol phenylbutyrate mediate waste nitrogen excretion in the form of urinary phenylacetylglutamine (PAGN) in patients with urea cycle disorders (UCDs); rare genetic disorders characterized by impaired urea synthesis and hyperammonemia. Sodium phenylbutyrate is approved for UCD treatment; the development of glycerol phenylbutyrate afforded the opportunity to characterize the pharmacokinetics (PK) of both compounds. A population PK model was developed using data fro...

  1. Rapid Hydrophilization of Model Polyurethane/Urea (PURPEG Polymer Scaffolds Using Oxygen Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Rok Zaplotnik

    2016-04-01

    Full Text Available Polyurethane/urea copolymers based on poly(ethylene glycol (PURPEG were exposed to weakly ionized, highly reactive low-pressure oxygen plasma to improve their sorption kinetics. The plasma was sustained with an inductively coupled radiofrequency generator operating at various power levels in either E-mode (up to the forward power of 300 W or H-mode (above 500 W. The treatments that used H-mode caused nearly instant thermal degradation of the polymer samples. The density of the charged particles in E-mode was on the order of 1016 m−3, which prevented material destruction upon plasma treatment, but the density of neutral O-atoms in the ground state was on the order of 1021 m−3. The evolution of plasma characteristics during sample treatment in E-mode was determined by optical emission spectroscopy; surface modifications were determined by water adsorption kinetics and X-ray photoelectron spectroscopy; and etching intensity was determined by residual gas analysis. The results showed moderate surface functionalization with hydroxyl and carboxyl/ester groups, weak etching at a rate of several nm/s, rather slow activation down to a water contact angle of 30° and an ability to rapidly absorb water.

  2. Effect of urea placement on leaching losses of nitrogen from flooded rice soils

    International Nuclear Information System (INIS)

    Vlek, P.L.G.; Byrnes, B.H.; Craswell, E.T.

    1980-01-01

    In an effort to provide an explanation for the reported variability in fertilizer N efficiency from deep-placed urea on flooded rice, a set of controlled experiments was conducted to evaluate the effect of water percolation on fertilizer loss and plant uptake from 15 N labeled urea supergranules. Three soils of different texture (silt loam-clay) were subjected to various percolation rates (0-20 mm/day) while planted to rice which was harvested after approximately 40 days. The results indicate that moderate to high percolation through silt loam soil will lead to significant fertilizer N losses and drastically decrease the fertilizer uptake by plants. The permeability of the clay soil was too low for any leaching to take place. It is therefore concluded that deep placement of urea supergranules not be recommended in soils where percolation rates may exceed 5 mm/day, particularly if the cation exchange capacity of the soil is low. This experiment points to the need of evaluating and reporting the percolation rates in soils where experiments with supergranular urea are conducted. (orig.)

  3. Effect of lime, urea and triple super phosphate on nitrogen and ...

    African Journals Online (AJOL)

    A study to investigate N and P mineralisation in an acid mollic Andosol was conducted through laboratory incubation for 120 days. Soil samples were taken from 0-15, 15-30 and 30-60 cm depths. Treatments applied were lime, urea and triple superphosphate (TSP) at rates equivalent to 2.5 t ha-1, 50 and 75 kg ha-1, ...

  4. Nitrogen uptake by wheat seedlings, interactive effects of four nitrogen sources: NO3-, NO2-, NH4+, and urea

    Science.gov (United States)

    Criddle, R. S.; Ward, M. R.; Huffaker, R. C.

    1988-01-01

    The net influx (uptake) rates of NO3-, NH4+, NO2-, and urea into roots of wheat (Triticum aestivum cv Yecora Rojo) seedlings from complete nutrient solutions containing all four compounds were monitored simultaneously. Although urea uptake was too slow to monitor, its presence had major inhibitory effects on the uptake of each of the other compounds. Rates of NO3-, NH4+, and NO2- uptake depended in a complex fashion on the concentration of all four N compounds. Equations were developed which describe the uptake rates of each of the compounds, and of total N, as functions of concentrations of all N sources. Contour plots of the results show the interactions over the range of concentrations employed. The coefficients of these equations provide quantitative values for evaluating primary and interactive effects of each compound on N uptake.

  5. Urea metabolism in plants.

    Science.gov (United States)

    Witte, Claus-Peter

    2011-03-01

    Urea is a plant metabolite derived either from root uptake or from catabolism of arginine by arginase. In agriculture, urea is intensively used as a nitrogen fertilizer. Urea nitrogen enters the plant either directly, or in the form of ammonium or nitrate after urea degradation by soil microbes. In recent years various molecular players of plant urea metabolism have been investigated: active and passive urea transporters, the nickel metalloenzyme urease catalyzing the hydrolysis of urea, and three urease accessory proteins involved in the complex activation of urease. The degradation of ureides derived from purine breakdown has long been discussed as a possible additional metabolic source for urea, but an enzymatic route for the complete hydrolysis of ureides without a urea intermediate has recently been described for Arabidopsis thaliana. This review focuses on the proteins involved in plant urea metabolism and the metabolic sources of urea but also addresses open questions regarding plant urea metabolism in a physiological and agricultural context. The contribution of plant urea uptake and metabolism to fertilizer urea usage in crop production is still not investigated although globally more than half of all nitrogen fertilizer is applied to crops in the form of urea. Nitrogen use efficiency in crop production is generally well below 50% resulting in economical losses and creating ecological problems like groundwater pollution and emission of nitric oxides that can damage the ozone layer and function as greenhouse gasses. Biotechnological approaches to improve fertilizer urea usage bear the potential to increase crop nitrogen use efficiency. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  6. Reverse osmosis membrane of high urea rejection properties. [water purification

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T. J. (Inventor)

    1980-01-01

    Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source. A polymeric membrane is formed by depositing a polymer of the unsaturated monomer from the plasma onto a substrate, so that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.

  7. Urea Recycling Contributes to Nitrogen Retention in Calves Fed Milk Replacer and Low-Protein Solid Feed

    NARCIS (Netherlands)

    Berends, H.; Borne, van den J.J.G.C.; Røjen, B.A.; Baal, van J.; Gerrits, W.J.J.

    2014-01-01

    Urea recycling, with urea originating from catabolism of amino acids and hepatic detoxification of ammonia, is particularly relevant for ruminant animals, in which microbial protein contributes substantially to the metabolizable protein supply. However, the quantitative contribution of urea

  8. Application of Response Surface Methodology for Optimization of Urea Grafted Multiwalled Carbon Nanotubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

    Directory of Open Access Journals (Sweden)

    Norazlina Mohamad Yatim

    2016-01-01

    Full Text Available Efficient use of urea fertilizer (UF as important nitrogen (N source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nanocarrier is developed based on functionalized multiwall carbon nanotubes (f-MWCNTs grafted with UF to produce urea-multiwall carbon nanotubes (UF-MWCNTs for enhancing the nitrogen uptake (NU and use efficiency (NUE. The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10–0.60 wt% and functionalization reflux time (12–24 hrs with the corresponding responses (NUE, NU were structured via the Response Surface Methodology (RSM based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms (p value < 0.05 for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.

  9. Application of Response Surface Methodology for Optimization of Urea Grafted Multi walled Carbon Nano tubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

    International Nuclear Information System (INIS)

    Yatim, N. M.; Shaaban, A.; Dimin, M. F.; Yusof, F.; Abo Razak, J.

    2016-01-01

    Efficient use of urea fertilizer (UF) as important nitrogen (N) source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nano carrier is developed based on functionalized multi wall carbon nano tubes (f-MWCNTs) grafted with UF to produce urea-multi wall carbon nano tubes (UF-MWCNTs) for enhancing the nitrogen uptake (NU) and use efficiency (NUE). The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10-0.60 wt%) and functionalization reflux time (12-24 hrs) with the corresponding responses (NUE, NU) were structured via the Response Surface Methodology (RSM) based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms (Þ value < 0.05) for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.

  10. Effect of bacterial root symbiosis and urea as source of nitrogen on performance of soybean plants grown hydroponically for Bioregenerative Life Support Systems (BLSSs).

    Science.gov (United States)

    Paradiso, Roberta; Buonomo, Roberta; Dixon, Mike A; Barbieri, Giancarlo; De Pascale, Stefania

    2015-01-01

    Soybean is traditionally grown in soil, where root symbiosis with Bradyrhizobium japonicum can supply nitrogen (N), by means of bacterial fixation of atmospheric N2. Nitrogen fertilizers inhibit N-fixing bacteria. However, urea is profitably used in soybean cultivation in soil, where urease enzymes of telluric microbes catalyze the hydrolysis to ammonium, which has a lighter inhibitory effect compared to nitrate. Previous researches demonstrated that soybean can be grown hydroponically with recirculating complete nitrate-based nutrient solutions. In Space, urea derived from crew urine could be used as N source, with positive effects in resource procurement and waste recycling. However, whether the plants are able to use urea as the sole source of N and its effect on root symbiosis with B. japonicum is still unclear in hydroponics. We compared the effect of two N sources, nitrate and urea, on plant growth and physiology, and seed yield and quality of soybean grown in closed-loop Nutrient Film Technique (NFT) in growth chamber, with or without inoculation with B. japonicum. Urea limited plant growth and seed yield compared to nitrate by determining nutrient deficiency, due to its low utilization efficiency in the early developmental stages, and reduced nutrients uptake (K, Ca, and Mg) throughout the whole growing cycle. Root inoculation with B. japonicum did not improve plant performance, regardless of the N source. Specifically, nodulation increased under fertigation with urea compared to nitrate, but this effect did not result in higher leaf N content and better biomass and seed production. Urea was not suitable as sole N source for soybean in closed-loop NFT. However, the ability to use urea increased from young to adult plants, suggesting the possibility to apply it during reproductive phase or in combination with nitrate in earlier developmental stages. Root symbiosis did not contribute significantly to N nutrition and did not enhance the plant ability to use

  11. Nitrogen-doped graphene by microwave plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Kumar, A.; Voevodin, A.A.; Paul, R.; Altfeder, I.; Zemlyanov, D.; Zakharov, D.N.; Fisher, T.S.

    2013-01-01

    Rapid synthesis of nitrogen-doped, few-layer graphene films on Cu foil is achieved by microwave plasma chemical vapor deposition. The films are doped during synthesis by introduction of nitrogen gas in the reactor. Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and scanning tunneling microscopy reveal crystal structure and chemical characteristics. Nitrogen concentrations up to 2 at.% are observed, and the limit is linked to the rigidity of graphene films on copper surfaces that impedes further nitrogen substitutions of carbon atoms. The entire growth process requires only a few minutes without supplemental substrate heating and offers a promising path toward large-scale synthesis of nitrogen-doped graphene films. - Highlights: ► Rapid synthesis of nitrogen doped few layer graphene on Cu foil. ► Defect density increment on 2% nitrogen doping. ► Nitrogen doped graphene is a good protection to the copper metallic surface

  12. Nitrogen-doped graphene by microwave plasma chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A., E-mail: kumar50@purdue.edu [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Voevodin, A.A. [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, WPAFB, OH 45433 (United States); Paul, R. [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Altfeder, I. [Materials and Manufacturing Directorate, Air Force Research Laboratory, WPAFB, OH 45433 (United States); Zemlyanov, D.; Zakharov, D.N. [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Fisher, T.S., E-mail: tsfisher@purdue.edu [Birck Nanotechnolgy Center, Purdue University, West Lafayette, IN 47907 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, WPAFB, OH 45433 (United States)

    2013-01-01

    Rapid synthesis of nitrogen-doped, few-layer graphene films on Cu foil is achieved by microwave plasma chemical vapor deposition. The films are doped during synthesis by introduction of nitrogen gas in the reactor. Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and scanning tunneling microscopy reveal crystal structure and chemical characteristics. Nitrogen concentrations up to 2 at.% are observed, and the limit is linked to the rigidity of graphene films on copper surfaces that impedes further nitrogen substitutions of carbon atoms. The entire growth process requires only a few minutes without supplemental substrate heating and offers a promising path toward large-scale synthesis of nitrogen-doped graphene films. - Highlights: ► Rapid synthesis of nitrogen doped few layer graphene on Cu foil. ► Defect density increment on 2% nitrogen doping. ► Nitrogen doped graphene is a good protection to the copper metallic surface.

  13. Pre-breeding blood urea nitrogen concentration and reproductive performance of Bonsmara heifers within different management systems.

    Science.gov (United States)

    Tshuma, Takula; Holm, Dietmar Erik; Fosgate, Geoffrey Theodore; Lourens, Dirk Cornelius

    2014-08-01

    This study investigated the association between pre-breeding blood urea nitrogen (BUN) concentration and reproductive performance of beef heifers within different management systems in South Africa. Bonsmara heifers (n = 369) from five herds with different estimated levels of nitrogen intake during the month prior to the commencement of the breeding season were sampled in November and December 2010 to determine BUN concentrations. Body mass, age, body condition score (BCS) and reproductive tract score (RTS) were recorded at study enrolment. Trans-rectal ultrasound and/or palpation was performed 4-8 weeks after a 3-month breeding season to estimate the stage of pregnancy. Days to pregnancy (DTP) was defined as the number of days from the start of the breeding season until the estimated conception date. Logistic regression and Cox proportional hazards survival analysis were performed to estimate the association of pre-breeding BUN concentration with subsequent pregnancy and DTP, respectively. After stratifying for herd and adjusting for age, heifers with relatively higher pre-breeding BUN concentration took longer to become pregnant when compared to those with relatively lower BUN concentration (P = 0.011). In the herd with the highest estimated nitrogen intake (n = 143), heifers with relatively higher BUN were less likely to become pregnant (P = 0.013) and if they did, it was only later during the breeding season (P = 0.017), after adjusting for body mass. These associations were not present in the herd (n = 106) with the lowest estimated nitrogen intake (P > 0.500). It is concluded that Bonsmara heifers with relatively higher pre-breeding BUN concentration, might be at a disadvantage because of this negative impact on reproductive performance, particularly when the production system includes high levels of nitrogen intake.

  14. Estimation of daily protein intake based on spot urine urea nitrogen concentration in chronic kidney disease patients.

    Science.gov (United States)

    Kanno, Hiroko; Kanda, Eiichiro; Sato, Asako; Sakamoto, Kaori; Kanno, Yoshihiko

    2016-04-01

    Determination of daily protein intake in the management of chronic kidney disease (CKD) requires precision. Inaccuracies in recording dietary intake occur, and estimation from total urea excretion presents hurdles owing to the difficulty of collecting whole urine for 24 h. Spot urine has been used for measuring daily sodium intake and urinary protein excretion. In this cross-sectional study, we investigated whether urea nitrogen (UN) concentration in spot urine can be used to predict daily protein intake instead of the 24-h urine collection in 193 Japanese CKD patients (Stages G1-G5). After patient randomization into 2 datasets for the development and validation of models, bootstrapping was used to develop protein intake estimation models. The parameters for the candidate multivariate regression models were male gender, age, body mass index (BMI), diabetes mellitus, dyslipidemia, proteinuria, estimated glomerular filtration rate, serum albumin level, spot urinary UN and creatinine level, and spot urinary UN/creatinine levels. The final model contained BMI and spot urinary UN level. The final model was selected because of the higher correlation between the predicted and measured protein intakes r = 0.558 (95 % confidence interval 0.400, 0.683), and the smaller distribution of the difference between the measured and predicted protein intakes than those of the other models. The results suggest that UN concentration in spot urine may be used to estimate daily protein intake and that a prediction formula would be useful for nutritional control in CKD patients.

  15. Study on the relationship between milk urea nitrogen (MUN and fertility in dairy cattle houses in Tabriz

    Directory of Open Access Journals (Sweden)

    S Mosaferi

    2011-08-01

    Full Text Available The aim of this study was to assess the relationship between milk urea nitrogen (MUN level and reproductive performance in high yielding dairy cattle houses in Tabriz, Iran. Among 213 selected dairy cattle, 76 heads (35.7% have MUN 16 mg/dl (mean = 17.46 mg/dl. Our results indicated that MUN level in 81 heads of dairy cattle (total 124 heads with mastitis, dystocia, laminitis, uterine infections or placenta replacement was higher than 16 mg/dl. We only observed a significantly positive association between MUN levels and dystocia (p= 0.032, while the association between MUN levels and incidence of other diseases was not statistically significant. The results of this study indicated that MUN level significantly influences the reproductive parameters including days open, calving to first service, first service conception risk, and number of services per conception (p

  16. Relationship among antineutrophil cytoplasmic antibody, blood urea nitrogen and complement in patients with eosinophilic granulomatosis polyangiitis (Churg-Strauss syndrome).

    Science.gov (United States)

    Kawakami, Tamihiro; Kimura, Satoko; Takeuchi, Sora; Soma, Yoshinao

    2013-07-01

    Eosinophilic granulomatosis with polyangiitis (EGPA), also known as Churg-Strauss syndrome, is an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis characterized by a history of asthma, hypereosinophilia. The prevalence of ANCA in EGPA is less common than in other ANCA-associated vasculitis. Increasing evidence of complement activation in the pathogenesis of ANCA-associated vasculitis has been provided by studies in animal models. We examined EGPA patients with cutaneous manifestations as an initial sign and investigated the correlations among clinical, serological and histopathological findings. We focused on differences among ANCA, blood urea nitrogen and complement levels such as complement 3 (C3), C4 and total complement hemolytic activity (CH50). We retrospectively investigated the records of 22 patients (11 male and 11 female) with EGPA admitted to our hospital from 1997-2012. Ten of the 22 patients (46%) were positive for serum myeloperoxidase (MPO)-ANCA. In contrast, all the patients were negative for serum proteinase 3 ANCA. There was a significantly positive correlation between serum CH50 and C4 levels in patients with EGPA. Serum blood urea nitrogen (BUN) levels differed significantly between MPO-ANCA-positive and -negative patients. Serum CH50 levels were higher in MPO-ANCA-positive patients compared to negative patients. Serum BUN levels were higher in elevated CH50 patients compared to normal and low CH50-negative patients. We propose that positive findings for MPO-ANCA with CH50 high activity may be a risk factor for developing renal insufficiency. Assuming there are correlations between the presence of ANCA and complements, earlier diagnosis based on initial efficacious treatment for EGPA. © 2013 Japanese Dermatological Association.

  17. The risk of death associated with proteinuria in heart failure is restricted to patients with an elevated blood urea nitrogen to creatinine ratio

    NARCIS (Netherlands)

    Brisco, Meredith A.; Zile, Michael R.; ter Maaten, Jozine M.; Hanberg, Jennifer S.; Wilson, F. Perry; Parikh, Chirag; Testani, Jeffrey M.

    2016-01-01

    Background: Renal dysfunction (RD) is associated with reduced survival in HF; however, not all RD is mechanistically or prognostically equivalent. Notably, RD associated with "pre-renal" physiology, as identified by an elevated blood urea nitrogen to creatinine ratio (BUN/Cr), identifies a

  18. Evolution of Spark plasma using nitrogen laser shadowgraphy system

    International Nuclear Information System (INIS)

    Ishiekwene, G.C.

    1994-07-01

    A simple, low cost, home built high power nitrogen laser is used as the light source for a shadowgraphy system. A series of shadowgrams depicting the temporal growth of a spark plasma discharge is obtained. The results could be useful in plasma diagnostic studies. (author). 5 refs, 6 figs

  19. Effect of abomasal infusion of oligofructose on portal-drained visceral ammonia and urea-nitrogen fluxes in lactating Holstein cows.

    Science.gov (United States)

    Røjen, B A; Larsen, M; Kristensen, N B

    2012-12-01

    The effects of abomasal infusion of oligofructose in lactating dairy cows on the relationship between hindgut fermentation and N metabolism, and its effects on NH(3) absorption and transfer of blood urea-N across the portal-drained viscera versus ruminal epithelia were investigated. Nine lactating Holstein cows fitted with ruminal cannulas and permanent indwelling catheters in major splanchnic blood vessels were used in an unbalanced crossover design with 14-d periods. Treatments were continuous abomasal infusion of water or 1,500 g/d of oligofructose. The same basal diet was fed with both treatments. Eight sample sets of arterial, portal, hepatic, and ruminal vein blood, ruminal fluid, and urine were obtained at 0.5h before the morning feeding and at 0.5, 1.5, 2.5, 3.5, 4.5, 5.5, and 6.5 h after feeding. It was hypothesized that an increased supply of fermentable substrate to the hindgut would increase the uptake of urea-N from blood to the hindgut at the expense of urea-N uptake to the forestomach. The study showed that abomasal oligofructose infusion decreased the total amount of urea-N transferred from the blood to the gut, NH(3) absorption, and arterial blood urea-N concentration. Subsequently, hepatic NH(3) uptake and urea-N production also decreased with oligofructose infusion. Additionally, urea-N concentration in milk and urinary N excretion decreased with oligofructose treatment. The oligofructose infusion did not affect ruminal NH(3) concentrations or any other ruminal variables, nor did it affect ruminal venous - arterial concentration differences for urea-N and NH(3). The oligofructose treatment did not affect milk yield, but did decrease apparent digestibility of OM, N, and starch. Nitrogen excreted in the feces was greater with the oligofructose infusion. In conclusion, the present data suggest that increased hindgut fermentation did not upregulate urea-N transfer to the hindgut at the expense of urea-N uptake by the rumen, and the observed reduction

  20. Studies on nitrogen use efficiency in turmeric using 15N tagged urea

    International Nuclear Information System (INIS)

    Jagadeeswaran, R.; Arulmozhiselvan, K.; Govindaswamy, M.; Murugappan, V.

    2004-01-01

    A greenhouse experiment was conducted with turmeric in order to understand the partitioning of N between shoot and rhizome and to study the N use efficiency using 15 N tagged urea. The experiment was conducted in a completely randomized block design with seven treatments consisting of whole N application as basal and split applications ranging from two to six, besides a control. The result indicated that N derived from 15 N urea (Ndff) increased with number of split application of N up to four splits in turmeric shoot and up to three splits in turmeric rhizome, both at 180 days as well as at harvest stage. Increasing the splits beyond this declined Ndff, which indicated that five and more number of splits of N would not help to increase the uptake of applied N. Thus, the present study clearly revealed that in turmeric, application of N in three splits would be optimal in increasing the Ndff in rhizome. Fertilizer N balance calculations clearly indicated that the recovery of N in turmeric was high in favour of four splits at 180 days growth stage (19.46 per cent) as well as at harvest (30.76 per cent). (author)

  1. Effect of dietary nitrogen content and intravenous urea infusion on ruminal and portal-drained visceral extraction of arterial urea in lactating Holstein cows

    DEFF Research Database (Denmark)

    Kristensen, Niels Bastian; Storm, Adam Christian; Larsen, Mogens

    2010-01-01

    Urea extraction across ruminal and portal-drained visceral (PDV) tissues were investigated using 9 rumen-cannulated and multi-catheterized lactating dairy cows adapted to low-N (12.9% crude protein) and high-N (17.1% crude protein) diets in a crossover design. The interaction between adaptation...... to arterial urea concentrations. Urea extraction increased more across the rumen wall than across the total PDV for low-N compared with high-N, which implies that a larger proportion of total PDV uptake of arterial urea is directed toward the rumen with decreasing N intake. The ruminal vein - arterial (RA......) concentration difference for ammonia increased instantly (first sampling 15 min after initiation of infusion) to the primed intravenous infusion when cows were adapted to the low-N diet. The RA difference for ammonia correlated poorly to the ventral ruminal concentration of ammonia (r = 0.55). Relating the RA...

  2. Quantitative aspect of the endogenous urea cycle in goats

    International Nuclear Information System (INIS)

    Ide, Yu

    1975-01-01

    The turnover of plasma urea was studied in goats fed rations with different protein contents by using 14 C- and 15 N-urea as tracers. The biological half-life time of urea determined with 15 N-urea was always longer than that determined with 14 C-urea, reflecting the difference in the metabolic pathway between the urea hydrolysates, ammonia and carbon dioxide. It was roughly estimated from the turnover studies that more than a half the quantity of urea synthesized might be transferred to the alimentary canal, including the rumen, where it underwent dissociation, with a decrease in the protein content of the ration, the percentage of transfer and dissociation increased. The 14 C-urea discharged into the urine was less than 57% of the administered dose. It decreased to 3.9% in goats fed rations with a low protein content. The rate of urea turnover determined with 15 N-urea was nearly consistent with the rate of urea discharge into the urine in goats fed higher protein rations. In goats fed lower protein rations, on the other hand, the rate of urea discharge decreased and its consistency with the rate of turnover determined with 15 N-urea was upset. This was caused by assimilation of urea-nitrogen in rumen microorganisms, as was convinced by studying the incorporation of urea- 15 N into the fraction of rumen microorganisms. It was assumed that in goats fed lower protein rations the bulk of urea synthesized might have entered the endogenous recycling system within the body and assimilated by rumen microorganisms. (auth.)

  3. INTAKE, DIGESTIBILITY AND PLASMA UREA NITROGEN IN HEIFERS FED SUPPLEMENTS WITH DIFFERENT RUMINAL UNDEGRADABLE PROTEIN LEVELS CONSUMO, DIGESTIBILIDADE E N-URÉICO PLASMÁTICO EM NOVILHAS RECEBENDO SUPLEMENTOS COM DIFERENTES NÍVEIS DE PROTEÍNA NÃO-DEGRADÁVEL NO RÚMEN

    Directory of Open Access Journals (Sweden)

    Adriana Regina Bagaldo

    2008-10-01

    Full Text Available

    The effects of supplements with different levels (high, medium, low of ruminal undegradable protein (RUP by Brown-Swiss heifers grazing Brachiaria brizantha cv. Marandu on the intake, digestibility and plasma N-urea concentrations were evaluated. The experiment lasted 90 days, divided in three periods of 30 days, corresponding to May, June and July 2000. Fifteen purebred Brown Swiss heifers (five by treatment, averaging 19.7 months and 394 kg live weight (LW, were used. The pasture availability was monitored to maintain offer of 6% LW, in green dry matter (GDM. The dry matter (DM availability, GDM and leaf:stem ratio were evaluated. The heifers were fed 2.5 kg/head/day of concentrate supplement, offered twice a day (8 a.m. and 4 p.m.. Extrusa was collected in oesophagus fistulated animals. Indigestible neutral detergent fiber (NDF in the feeds and feces was used to determine the intake and digestibility. There were no effects of supplements on the pasture, however there were differences among periods, because, as dry season progressed, the forage availability decreased and leaf/stem ratio and senescent material proportion increased. There was no effect of treatments on forage intake or forage + supplement. DM, organic matter (OM and CP digestibility, and total digestible nutrients (TDN content were lower for the diets with high RUP content. It was observed interaction of period:treatment for the fiber digestibility, where in the treatments with high and medium RUP, the digestibility decreased as the dry season progressed and, in the treatment with low RUP, the digestibility increased. The animals fed supplement with high RUP content showed average plasma N-urea concentrations lower than those fed supplement with average RUP contents, followed by those fed diets with low RUP.

    KEY WORDS: Brachiaria brizantha, rotational grazing, escape protein, supplementation.

  4. Slow-release urea in supplement fed to beef steers

    Directory of Open Access Journals (Sweden)

    Ana Paula Gonçalves

    2015-02-01

    Full Text Available Replacing regular urea (RU by slow-release urea (SRU at two levels of non-protein nitrogen (NPN in concentrate, offered with low-quality roughage, was evaluated in beef steers on dry matter intake (DMI, ruminal fermentation parameters, plasma urea nitrogen (PUN, total tract apparent digestibility of diets and in situ degradability of nitrogen sources. Eight ruminally cannulated steers were allocated into two 4x4 Latin squares, totalizing four treatments: 40 NPN/0 SRU: 40% of concentrate crude protein (CP as NPN, resulting from 0% of SRU and 100% of RU; 40 NPN/50 SRU: 40% of concentrate CP as NPN, resulting from 50% of SRU and 50% of RU; 40 NPN/100 SRU: 40% of concentrate CP as NPN, resulting from 100% of SRU and 0% of RU; 80 NPN/100 SRU: 80% of concentrate CP as NPN, resulting from 100% of SRU and 0% of RU. Results showed that partial substitution of regular urea by slow-release urea did not alter dry matter intake, pattern of ruminal fermentation or plasma urea nitrogen concentrations and increased the total tract apparent digestibility of crude protein in steers diets. The increase in non-protein nitrogen content in crude protein of the concentrate could compromise feed intake and the efficiency of nutrient utilization in the steers fed complete diets based on low quality forage.

  5. Parâmetros fermentativos, produção de proteína microbiana, concentrações de ureia no leite e no plasma e balanço de nitrogênio de vacas alimentadas com silagem de milho ou cana-de-açúcar com caroço de algodão Fermentative parameters, microbial protein production, plasma and milk urea concentration and nitrogen balance of milking cows fed maize silage or sugarcane with whole cottonseed

    Directory of Open Access Journals (Sweden)

    Daniel de Paula Sousa

    2009-10-01

    Full Text Available Doze vacas da raça Holandesa foram distribuídas em três quadrados latinos 4 × 4 com o objetivo de avaliar o pH, o N-amoniacal, a produção de proteína microbiana, o número de protozoários no rúmen, a concentração de N-ureia no plasma e no leite e balanço de nitrogênio. Os tratamentos consistiram de silagem de milho ou cana-de-açúcar contendo 0, 7 ou 14% de caroço de algodão. Não houve diferença no pH quando fornecida cana-de-açúcar, apesar da diminuição dos valores após o início da alimentação. Os valores de N-amoniacal mantiveram-se acima de 15 mg/dL, após 6 horas de alimentação, apenas quando fornecida silagem de milho e cana-de-açúcar com 7% de caroço de algodão. O maior consumo de MS e nutrientes obtido com a silagem de milho implicou em menor eficiência de uso do nitrogênio e maiores excreções de N-ureia na urina em relação às demais dietas (150,6 vs 96,0 mg/kg PV. O fornecimento de cana-de-açúcar com 7% de caroço de algodão promoveu maiores quantidades de purinas totais (PT, purinas absorvidas (PA, nitrogênio microbiano (207, 6 vs 185,2 g/dia e melhor balanço de compostos nitrogenados (31,5 vs 15,5 em relação às demais dietas com cana-de-açúcar. O menor consumo de MS e extrato etéreo quando fornecida cana-de-açúcar sem caroço de algodão resultou em maior número de protozoários (129,4 vs 34,0 × 10³/mL, maior excreção urinária de nitrogênio e menor síntese de proteína microbiana em relação às demais dietas, o que indica falta de sincronização na degradação da energia e proteína na relação volumoso:concentrado proposta neste experimento.Twelve cows were allotted to three 4 × 4 Latin Squares to evaluate pH, ammonium nitrogen, microbial protein production, number of protozoa in the rumen, plasma and milk urea concentration and balance of nitrogen compounds. Treatments consisted of maize silage or sugarcane with whole cottonseed, at 0, 7 or 14%. There were no

  6. f-Ratios calculated with and without urea uptake in nitrogen uptake by phytoplankton

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Corre, P.L.; L'Helguen, S.

    . Peterson (1979) Particulate organic matter Hux and planktonic new production in the deep ocean. Nature, 282,677-6X0. Epplcy R. W., .I. H. Sharp, E. H. Renger, M. J. Perry and W. G. Harrison (1977) Nitrogen assimilation by phytoplankton and other... f’rogress Serres. 67, 275-2X3. Harrison W. G.. I_. R. Harris, D. M. Karl. G. A. Knauer and D. G. Redaljc (1992) Nitrogen dynamics at the Vcrtcx time-series site. DeepSea Revearch. 39, 1.535-1557. Harvey W. A. and J. Caperon (1976) The rate...

  7. Nitrogen balance and milk composition of dairy cows fed urea and soybean meal and two protein levels using sugar cane based diets

    OpenAIRE

    Luís Henrique Andreucci Conti; Elmeson Ferreira de Jesus; Angélica Simone Cravo Pereira; Marcos André Arcari; Kleber da Cunha Peixoto Junior; Francisco Palma Rennó; Marcos Veiga dos Santos

    2014-01-01

    The aim of the study was to evaluate the effect of feeding two levels of crude protein (CP) (low: 142 g CP/kg DM; and high: 156 g CP/kg DM) and two nitrogen sources (soybean meal and urea) to dairy cows using sugar cane as forage on microbial protein synthesis, the composition of the milk nitrogen fraction, nitrogen (N) balance and blood parameters. Twelve Holstein cows with an average milk yield of 22.0 ± 2.3 kg/day, and with 235 ± 40 days in milk were included in this study. The animals wer...

  8. Influence of slow-release urea on nitrogen balance and portal-drained visceral nutrient flux in beef steers

    DEFF Research Database (Denmark)

    Taylor-Edwards, C C; Elam, N A; Kitts, S E

    2009-01-01

    Two experiments were conducted to evaluate the effects of slow-release urea (SRU) versus feed-grade urea on portal-drained visceral (PDV) nutrient flux, nutrient digestibility, and total N balance in beef steers.......Two experiments were conducted to evaluate the effects of slow-release urea (SRU) versus feed-grade urea on portal-drained visceral (PDV) nutrient flux, nutrient digestibility, and total N balance in beef steers....

  9. Speed associated with plasma pH, oxygen content, total protein and urea in an 80 km race.

    Science.gov (United States)

    Hoffman, R M; Hess, T M; Williams, C A; Kronfeld, D S; Griewe-Crandell, K M; Waldron, J E; Graham-Thiers, P M; Gay, L S; Splan, R K; Saker, K E; Harris, P A

    2002-09-01

    To test the hypothesis that endurance performance may be related quantitatively to changes in blood, we measured selected blood variables then determined their reference ranges and associations with speed during an 80 km race. The plan had 46 horses in a 2 x 2 factorial design testing a potassium-free electrolyte mix and a vitamin supplement. Blood samples were collected before the race, at 21, 37, 56 and 80 km, and 20 min after finishing, for assay of haematocrit, plasma pH, pO2, pCO2, [Na+], [K+], [Ca++], [Mg++], [Cl-], lactate, glucose, urea, cortisol, alpha-tocopherol, ascorbate, creatine kinase, aspartate amino transferase, lipid hydroperoxides, total protein, albumin and creatinine, and erythrocyte glutathione and glutathione peroxidase. Data from 34 finishers were analysed statistically. Reference ranges for resting and running horses were wide and overlapping and, therefore, limiting with respect to evaluation of individual horses. Speed correlations were most repeatable, with variables reflecting blood oxygen transport (enabling exercise), acidity and electrolytes (limiting exercise) and total protein (enabling then, perhaps, limiting). Stepwise regressions also included plasma urea concentration (limiting). The association of speed with less plasma acidity and urea suggests the potential for fat adaptation and protein restriction in endurance horses, as found previously in Arabians performing repeated sprints. Conditioning horses fed fat-fortified and protein-restricted diets may not only improve performance but also avoid grain-associated disorders.

  10. Urea recycling contributes to nitrogen retention in calves fed milk replacer and low-protein solid feed

    DEFF Research Database (Denmark)

    Berends, Harma; van den Borne, Joost J G C; Røjen, Betina A.

    2014-01-01

    Urea recycling, with urea originating from catabolism of amino acids and hepatic detoxification of ammonia, is particularly relevant for ruminant animals, in which microbial protein contributes substantially to the metabolizable protein supply. However, the quantitative contribution of urea...... recycling to protein anabolism in calves during the transition from preruminants (milk-fed calves) to ruminants [solid feed (SF)-fed calves] is unknown. The aim of this study was to quantify urea recycling in milk-fed calves when provided with low-protein SF. Forty-eight calves [164 ± 1.6 kg body weight (BW......)] were assigned to 1 of 4 SF levels [0, 9, 18, and 27 g of dry matter (DM) SF · kg BW2-0.75 . d-1] provided in addition to an identical amount of milk replacer. Urea recycling was quantified after a 24-h intravenous infusion of [15N2]urea by analyzing urea isotopomers in 68-h fecal and urinary...

  11. Vibrational, atomical and electronic relaxation in a nitrogen plasma jet

    International Nuclear Information System (INIS)

    Asselin, P.; Dudeck, M.

    1994-07-01

    This is a simplified approach of the characterization of a plasma stationary flow in chemical and electronic disequilibrium conditions by Navier-Stokes equations. The INCA code (AMTEC, USA) is a three-dimensional monolithic calculation code. A computer program for a mono-dimensional evolution of the formed species concentrations in a nitrogen plasma, including conservative equations of vibrational and electronic energies in order to deduce the corresponding temperature profiles. (A.B.). 14 refs., 17 figs., 2 tabs

  12. Controlled Release Urea as a Nitrogen Source for Spring Wheat in Western Canada: Yield, Grain N Content, and N Use Efficiency

    Directory of Open Access Journals (Sweden)

    Lenz Haderlein

    2001-01-01

    Full Text Available Controlled release nitrogen (N fertilizers have been commonly used in horticultural applications such as turf grasses and container-grown woody perennials. Agrium, a major N manufacturer in North and South America, is developing a low-cost controlled release urea (CRU product for use in field crops such as grain corn, canola, wheat, and other small grain cereals. From 1998 to 2000, 11 field trials were conducted across western Canada to determine if seed-placed CRU could maintain crop yields and increase grain N and N use efficiency when compared to the practice of side-banding of urea N fertilizer. CRU was designed to release timely and adequate, but not excessive, amounts of N to the crop. Crop uptake of N from seed-placed CRU was sufficient to provide yields similar to those of side-banded urea N. Grain N concentrations of the CRU treatments were higher, on average, than those from side-banded urea, resulting in 4.2% higher N use efficiency across the entire N application range from 25 to 100 kg ha-1. Higher levels of removal of N in grain from CRU compared to side-banded urea can result in less residual N remaining in the soil, and limit the possibility of N losses due to denitrification and leaching.

  13. Interrelationship of βeta-2 microglobulin, blood urea nitrogen and creatinine in streptozotocin -induced diabetes mellitus in rabbits

    Directory of Open Access Journals (Sweden)

    Shahram Javadi

    2013-12-01

    Full Text Available Measurement of serum creatinine (Cr and blood urea nitrogen (BUN are used as indicators of glomerular filtration rate. The increased levels of these biomarkers are usually detectable at advanced stages of kidney complications. The aim of this study was to find the interrelationship of beta-2 microglobulin (β2M, BUN and Cr in streptozotocin (STZ-induced diabetes mellitus in rabbits. Diabetes was induced by a single intraperitoneal (IP injection of 65 mg kg-1 of STZ in rabbits. The levels of serum insulin, glucose and three above mentioned biomarkers were measured one day before (day -1 and on days 1-3 after injection of STZ and continued weekly to the end of the experiment (12 weeks. A statistically significant increase of serum β2M, BUN, Cr and glucose levels, and a significant decrease of insulin levels were observed in diabetic animals. However, β2M levels increased as early as one day after STZ injection compared to Cr and BUN that elevated at day two, suggesting a probable diagnostic advantage of β2M over currently used biomarkers in diabetic related kidney complications.

  14. Reference Ranges of Serum Blood Urea Nitrogen, Creatinine Concentration and Ultrasonographic Measurement of the Kidneys in Term Healthy Newborns in the Neonatal Period

    Directory of Open Access Journals (Sweden)

    Şebnem Kader

    2017-12-01

    Full Text Available Objective: Acute kidney injury is an important problem in neonates. We conducted a cross-sectional prospective study to determine normal serum blood urea nitrogen, creatinine reference ranges and ranges of ultrasonographic measurement of kidneys in healthy term newborns. Study Design: Blood samples were collected from total 357 healthy newborns at birth (n=45, 1st (n=30, 3rd (n=61, 7th (n=34, 10th (n=132, 14th (n=36, and 28th (n=19 days of life. Renal ultrasonographic was performed by the same two radiologists on 81 newborns aged 10 days. Results: Serum blood urea nitrogen and creatinine concentrations have reached to the highest level at the first day of life and have returned to cord level at the third day of life. There were gradually decrease in serum blood urea nitrogen and creatinine levels after the first day of life. There were significant difference in both right and left renal length, width, and volumes in terms of gender and these parameters were statistically higher in boys than girls (p<0.05. Birth weight of the boys (3548±539g was statistically higher than girls (3307±405 g (p=0.028. There was a positive correlation between birth weight and right (r=0.38, p=0.000 and left kidney volumes (r=0.44, p=0.000. Conclusion: Our findings showed that measured blood urea nitrogen and creatinine levels changed in accordance with postnatal days and there was a positive correlation between kidney volume and birth weight of newborns. We concluded that these findings are important for evaluation of acute kidney injury and for screening of for urinary tract anomalies in neonates

  15. Ammonia production in nitrogen seeded plasma discharges in ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, V., E-mail: Volker.Rohde@ipp.mpg.de; Oberkofler, M.

    2015-08-15

    In present tokamaks nitrogen seeding is used to reduce the power load onto the divertor tiles. Some fraction of the seeded nitrogen reacts with hydrogen to form ammonia. The behaviour of ammonia in ASDEX Upgrade is studied by mass spectrometry. Injection without plasma shows strong absorption at the inner walls of the vessel and isotope exchange reactions. During nitrogen seeding in H-mode discharges the onset of a saturation of the nitrogen retention is observed. The residual gas consists of strongly deuterated methane and ammonia with almost equal amounts of deuterium and protium. This confirms the role of surface reactions in the ammonia formation. The results are consistent with findings in previous investigations. A numerical decomposition of mass spectra is under development and will be needed for quantitative evaluation of the results obtained.

  16. Effects of dietary crude protein and rumen-degradable protein concentrations on urea recycling, nitrogen balance, omasal nutrient flow, and milk production in dairy cows.

    Science.gov (United States)

    Mutsvangwa, T; Davies, K L; McKinnon, J J; Christensen, D A

    2016-08-01

    The objective of this study was to determine how interactions between dietary crude protein (CP) and rumen-degradable protein (RDP) concentrations alter urea-nitrogen recycling, nitrogen (N) balance, omasal nutrient flow, and milk production in lactating Holstein cows. Eight multiparous Holstein cows (711±21kg of body weight; 91±17d in milk at the start of the experiment) were used in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of dietary treatments and 29-d experimental periods. Four cows in one Latin square were fitted with ruminal cannulas to allow ruminal and omasal sampling. The dietary treatment factors were CP (14.9 vs. 17.5%; dry matter basis) and RDP (63 vs. 69% of CP) contents. Dietary RDP concentration was manipulated by including unprocessed or micronized canola meal. Diet adaptation (d 1-20) was followed by 8d (d 21-29) of sample and data collection. Continuous intrajugular infusions of [(15)N(15)N]-urea (220mg/d) were conducted for 4d (d 25-29) with concurrent total collections of urine and feces to estimate N balance and whole-body urea kinetics. Proportions of [(15)N(15)N]- and [(14)N(15)N]-urea in urinary urea, and (15)N enrichment in feces were used to calculate urea kinetics. For the low-CP diets, cows fed the high-RDP diet had a greater DM intake compared with those fed the low-RDP diet, but the opposite trend was observed for cows fed the high-CP diets. Dietary treatment had no effect on milk yield. Milk composition and milk component yields were largely unaffected by dietary treatment; however, on the low-CP diets, milk fat yield was greater for cows fed the low-RDP diet compared with those fed the high-RDP diet, but it was unaffected by RDP concentration on the high-CP diets. On the high-CP diets, milk urea nitrogen concentration was greater in cows fed the high-RDP diet compared with those fed the low-RDP diet, but it was unaffected by RDP concentration on the low-CP diets. Ruminal NH3-N concentration tended to

  17. Use of 15N methodology to assess urea use efficiency under different nitrogen levels in fertigation system and comparison with furrow irrigation on tomato

    International Nuclear Information System (INIS)

    Mousavi Shalmani, M. A.; Sagheb, N.; Hobbi, M.S.; Teimoori, S.; Khorasani, A.; Piervali, N.

    2003-01-01

    In order to determine a suitable level of nitrogen fertilizer for simultaneous increasing the nitrogen fertilizer use efficiency and the yield production under the trickle fertigation system in comparison with the furrow irrigation, an experimental design was conducted in a randomized complete block with five treatments and four replications in plots of 35 square meters area. The treatments of N 0 , N 1 , N 2 and N 3 received 0, 100, 150 and 200 mg N/lit, respectively under the trickle fertigation, and for the treatment of Ns the amount of fertilizer were equal to N 2 but under the furrow irrigation system. Fertilization and irrigation were performed by means of two fertigator pumps (one for urea and the other for ammonium phosphate and potassium sulfate) . In order to determine the nitrogen fertilizer use efficiency, six plants in the middle of each plot received 15 N labeled urea (isotopic form of 14 N) through plastic containers. Irrigation schedule and soil moisture monitoring were performed by means of a neutron gauge. The results showed that in spite of increasing the nitrogen levels in the fertigation system, the nitrogen fertilizer use efficiency decreases. In this respect, the treatment of N 1 could absorb %54 of nitrogen fertilizer which indicated that the highest fertilizer use efficiency under the current design condition and the final nitrogen fertilizer use efficiency for N 2 and N 3 treatments are %39 and %31, respectively. In addition, the traditional treatment (Ns), with %83 losses of nitrogen had the lowest rate of fertilizer use efficiency

  18. Urea utilization in protein deficient rats

    International Nuclear Information System (INIS)

    Tanaka, Noriko

    1982-01-01

    Three experiments were performed to investigate the mechanism of urea utilization and the nutritional roles of intestinal flora on the utilization of urea by rats fed with a protein deficient diet. Ammonia content in the small intestine in LPD(low protein diet) group fed with a low protein diet for 2 or 5 weeks was about three of five times higher than that of control group fed with SPD(standard protein diet) after administration of urea (0.2gN/100gB.W.). The 15 N incorporation into plasma protein of LPD group was significantly higher than that of the control group two hours after the administration of 15 N-urea (10 mg/100gB.W.) and higher level of 15 N concentration in plasma protein in LPD group was maintained thereafter. The 15 N incorporation into the amino acids of plasma protein was higher in LPD group than in control group. The 15 N incorporation into the amino acids in portal plasma seemed to be higher in LPD group than in control group one hour after the administration of 15 N-urea (10mg/100gB.W.). However, the 15 N incorporation into each free amino acids was suppressed considerably by the administration of antibiotic mixture. it follows that amino acids may be synthesized from urea in the intestine by intestinal-bacterial action and absorbed from portal vein. From these results, it may be concluded that the ammonia nitrogen converted from urea by the action of intestinal-bacterial urease in the intestine is utilized for the synthesis of essential and nonessential amino acids in protein deficient rats and transfered to the liver through portal vein and utilized for protein synthesis. (J.P.N.)

  19. Urea utilization in protein deficient rats

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, N [Hyogo College of Medicine, Nishinomiya, Hyogo (Japan)

    1982-06-01

    Three experiments were performed to investigate the mechanism of urea utilization and the nutritional roles of intestinal flora on the utilization of urea by rats fed with a protein deficient diet. Ammonia content in the small intestine in LPD(low protein diet) group fed with a low protein diet for 2 or 5 weeks was about three of five times higher than that of control group fed with SPD(standard protein diet) after administration of urea (0.2gN/100gB.W.). The /sup 15/N incorporation into plasma protein of LPD group was significantly higher than that of the control group two hours after the administration of /sup 15/N-urea (10 mg/100gB.W.) and higher level of /sup 15/N concentration in plasma protein in LPD group was maintained thereafter. The /sup 15/N incorporation into the amino acids of plasma protein was higher in LPD group than in control group. The /sup 15/N incorporation into the amino acids in portal plasma seemed to be higher in LPD group than in control group one hour after the administration of /sup 15/N-urea (10mg/100gB.W.). However, the /sup 15/N incorporation into each free amino acids was suppressed considerably by the administration of antibiotic mixture. it follows that amino acids may be synthesized from urea in the intestine by intestinal-bacterial action and absorbed from portal vein. From these results, it may be concluded that the ammonia nitrogen converted from urea by the action of intestinal-bacterial urease in the intestine is utilized for the synthesis of essential and nonessential amino acids in protein deficient rats and transfered to the liver through portal vein and utilized for protein synthesis.

  20. Clinical application of four plasma tumor markers and 13C-urea test in diagnosis of patients with gastric carcinoma

    International Nuclear Information System (INIS)

    Pu Weigang; Tan Jifu; Zhu Jianhua; Yang Yongqing

    2010-01-01

    Objective: To investigate clinical value of plasma gastrin, leptin, carbohydrate antigen 125 (CA125), carbohydrate antigen 72-4 (CA72-4) and 13 C-urea breath test ( 13 C-UBT) in diagnosis of patients with gastric carcinoma. Methods: Radioimmunoassay and enzyme immunosorbent assay were used to determine the plasma gastrin, leptin, CA125 and CA72-4 levels, and helicobacter pylori (HP) infection rate was determined by 13 C-UBT. Compared all the determined results from 126 patients with gastric carcinoma (including 32 cases I-II stage gastric carcinoma, 57 cases III stage gastric carcinoma and 37 cases IV stage gastric carcinoma) and 60 normal controls. Results: The plasma gastrin, CA125 and CA72-4 levels in 126 patients with gastric carcinoma were significantly higher (t=3.125, t=3.159, t=3.788, P 13 C-UBT played a considerable role for diagnosis and therapy. (authors)

  1. Reduction of nitrogen oxides by injection of urea in the freeboard of a pilot scale fluidized bed combustor

    NARCIS (Netherlands)

    Knol, Koen E.; Bramer, Eduard A.; Valk, M.

    1989-01-01

    The ‘thermal deNOx’ process using urea has been investigated in a 1 MW fluidized bed combustor. NOx reductions of up to 76% were obtainable by using this method. The experimental results show that urea is at least as active as NH3, which is commonly used in this application, but which is far more

  2. Profile of Rumen Fermentation and Blood Urea Nitrogen Concentration of Kacang Goat Fed Total Mixed Ration Vs. Roughage

    Science.gov (United States)

    Adiwinarti, R.; Kustantinah; Budisatria, I. G. S.; Rusman; Indarto, E.

    2018-02-01

    Kacang goat is usually reared traditionally fed natural grass and having inferior performance. Many researches had been done to improve the performance. Total mixed ration (TMR) containing soybean meal (SBM) and fish meal (FM) could increase the performance of Kacang goat, but the profile of rumen fermentation has not been published. Therefore, this study investigated the profile of rumen fermentation and blood urea Nitrogen concentration (BUN) in Kacang goat fed natural grass (roughage) and TMR. Twelve yearling Kacang buck, 15.2-19.6 kg were arranged in completely randomized design. The treatments were NG (natural grass), FM (TMR containing FM), and SBM (TMR containing SBM). The TMR were formulated containing 15% crude protein and 56-58% TDN. Data were analyzed by one way ANOVA. Rumen pH 6 hours after feeding of NG (7.4) was higher (P<0.01) than that of FM (6.2) and SBM (6.4). This lowering pH of TMR was caused by increasing volatile fatty acids (VFA). The VFA total of FM (129.7 mmol/l) and SBM (153.1 mmol/l) were higher than that of NG (86.4 mmol/l). At 3 and 6 hours after feeding, ammonia in the rumen of SBM was higher than that of NG and FM, indicating higher degraded protein. The BUN at 3 hours after feeding of SBM was higher than that of NG. It can be concluded that protein in SBM was degraded higher than others and the lower pH in rumen of TMR goats was caused by higher VFA produced by TMR goats compared to NG goats.

  3. Evaluation of Controlled Release Urea on the Dynamics of Nitrate, Ammonium, and Its Nitrogen Release in Black Soils of Northeast China

    Directory of Open Access Journals (Sweden)

    Xin Tong

    2018-01-01

    Full Text Available Controlled release urea (CRU is considered to enhance crop yields while alleviating negative environmental problems caused by the hazardous gas emissions that are associated with high concentrations of ammonium (NH4+ and nitrate (NO3− in black soils. Short-term effects of sulfur-coated urea (SCU and polyurethane-coated urea (PCU, compared with conventional urea, on NO3− and NH4+ in black soils were studied through the buried bag experiment conducted in an artificial climate chamber. We also investigated nitrogen (N release kinetics of CRU and correlations between the cumulative N release rate and concentrations of NO3− and NH4+. CRU can reduce concentrations of NO3− and NH4+, and PCU was more effective in maintaining lower soil NO3−/NH4+ ratios than SCU and U. Parabolic equation could describe the kinetics of NO3− and NH4+ treated with PCU. The Elovich equation could describe the kinetics of NO3− and NH4+ treated with SCU. The binary linear regression model was established to predict N release from PCU because of significant correlations between the cumulative N release rate and concentrations of NO3− and NH4+. These results provided a methodology and data support for characterizing and predicting the N release from PCU in black soils.

  4. Effect of Tree Leaves on Rumen Fermentation, Microbial Count and Blood Urea Nitrogen of West African Dwarf Goats

    Directory of Open Access Journals (Sweden)

    Adelusi, O. O.

    2016-12-01

    Full Text Available This experiment was carried out to assess the effect of Azadirachta indica, Newbouldia laevis and Spondias mombin leaves on rumen fermentation, microbial count and blood urea nitrogen (BUN of West African Dwarf (WAD goats. Sixteen WAD bucks (11.6 ? 0.9 kg in body weight were allocated to 4 treatments: 1 Control and 2 40 g/day of Azadirachta indica, 3 40 g/day of Newbouldia laevis and 4 40 g/day of Spondias mombin leaves arranged in a completely randomised design. The ground leaves were included in concentrate diets served on dry matter basis at 2% of body weight while Panicum maximum was fed ad libitum. The control diet had no tree leaves. Data were collected on chemical composition, rumen fermentation and microbial ecology, and BUN. Saponin was highest (P < 0.05 in S. mombin (8.14% while A. indica and N. laevis had 5.78% and 1.56%, respectively. Rumen ammonia nitrogen was least (P < 0.05 in goats fed A. indica (8.35 mg/dL while the highest (P < 0.05 total volatile fatty acid (TVFA was obtained from goats fed S. mombin with 125.51 mM. Goats fed N. laevis yielded the highest (P < 0.05 acetate with 70.65 mol/100 mol while propionate production was highest (P < 0.05 in the rumen of goats fed S. mombin (27.15 mol/100 mol. Viable bacteria count was lowest (P < 0.05 in rumen of goats fed A. indica (3.95?1012 cfu/ml while the least (P < 0.05 protozoa population was obtained from the rumen of bucks fed S. mombin (4.18?109 cfu/ml. All goats in the treatments containing tree leaves had higher (P < 0.05 and a rapid increase in BUN between 0 and 6 h post feeding when compared with the Control. It is concluded that feeding ground leaves of S. mombin to goats increases rumen total volatile fatty acid and propionate production and reduces the protozoa population.

  5. Effect of nitrogen doping on the microstructure and visible light photocatalysis of titanate nanotubes by a facile cohydrothermal synthesis via urea treatment

    International Nuclear Information System (INIS)

    Hu, Cheng-Ching; Hsu, Tzu-Chien; Lu, Shan-Yu

    2013-01-01

    A facile one-step cohydrothermal synthesis via urea treatment has been adopted to prepare a series of nitrogen-doped titanate nanotubes with highly efficient visible light photocatalysis of rhodamine B, in an effect to identify the effect of nitrogen doping on the photodegradation efficiency. The morphology and microstructure of the thus-prepared N-doped titanates were characterized by nitrogen adsorption/desorption isotherms, transmission electron microscopy, and scanning electron microscopy. With increasing urea loadings, the N-doped titanates change from a porous multi-layer and nanotube-shaped to a dense and aggregated particle-shaped structure, accompanied with reduced specific surface area and pore volume and enhanced pore diameter. Interstitial linkage to titanate via Ti-O-N and Ti-N-O is confirmed by X-ray photoelectron spectroscopy. Factors governing the photocatalytic degradation such as the specific surface area of the catalyst and the degradation pathway are analyzed, a mechanistic illustration on the photodegradation is provided, and a 3-stage degradation mechanism is identified. The synergistic contribution due to the enhanced deethylation and chromophore cleavage on rhodamine B molecules and the reduced band gap on the catalyst TiO 2 by interstitial nitrogen-doping has been accounted for the high photodegradation efficiency of the N-doped titanate nanotubes.

  6. The influence of nitrogen entrainment on argon plasmas created by the 'Torche à Injection Axiale' (TIA)

    NARCIS (Netherlands)

    Jonkers, J.; Hartgers, A.; Selen, L.J.M.; Mullen, van der J.J.A.M.; Schram, D.C.

    1999-01-01

    When a plasma is sustained in the open air, nitrogen will diffuse into the plasma. Especially for plasmas sustained by the `Torche à Injection Axiale' (TIA) this appears to be the case, since this turbulent jet draws gases from the surroundings. In the argon plasma the entrained nitrogen is probably

  7. Increase in fertilizer nitrogen use efficiency in lowland rice with application of dicyandiamide and pellet urea formulation

    International Nuclear Information System (INIS)

    Sachdev, M.S.; Sachdev, P.; Jain, Neeru

    2008-01-01

    Two greenhouse and one field experiment were conducted in a sandy clay loam Typic Ustochrept soil of the Indian Agricultural Research Institute farm using 15 N labeled urea and dicyandiamide (DCD). The results clearly revealed that application of DCD with urea resulted in significant increase in paddy yield and both total and fertilizer N uptake. The application of full dose of N as urea plus DCD in the form of 1.0 g pellets and given as basal gave the highest yield compared to that obtained with application of urea in two splits in the prilled form. The 15 N fertilizer balance data showed that maximum amount of unaccounted fertilizer 15 N was in the treatment where urea was applied in full dose in the prilled form as basal and it was least in the treatment where it was applied in the form of pellets of 1.0 g along with DCD. The ammonium N concentration in flood water was significantly higher in treatments where urea was applied in prilled form and with or without DCD. However urea application in the pellet form and particularly in combination with DCD reduced the ammonium concentration in floodwater appreciably. (author)

  8. Urea recycling from the renal pelvis in sheep: A study with [14C]urea

    International Nuclear Information System (INIS)

    Cirio, A.; Boivin, R.

    1990-01-01

    To test the hypothesis that urea can be recycled from the renal pelvis, [14C]urea diluted in native urine (1 microCi/ml) was perfused (0.5 ml/min) into one of the pelvises of sheep fed either normal (NP) or low (LP)-protein diets. Blood samples were obtained from the ipsilateral renal vein and from the carotid artery throughout the perfusions. 14C activity determinations in urine and plasma demonstrated a flux of [14C]urea from the pelvis to renal vein blood (40,000 in NP and 130,000 disintegrations/min in LP sheep, P less than 0.01). The corresponding flux of native urea was only 1.5 times higher in NP than in LP sheep (6.8 +/- 1.1 vs. 4.7 +/- 2.9 mumol/min, not significant) despite their 8 times higher urinary concentration of urea. The fraction of filtered urea that was reabsorbed in the pelvis was larger in LP sheep (7.5 +/- 3.7 vs. 1.9 +/- 0.7% in NP sheep, P less than 0.05). A fraction of urea is thus actually recycled from the renal pelvis in sheep, and this pelvic retention is enhanced in LP animals. The importance of this phenomenon in the nitrogen economy is discussed

  9. Blood Urea Nitrogen Test

    Science.gov (United States)

    ... to affect the kidneys, such as diabetes or high blood pressure , then creatinine and BUN tests may be used to monitor ... the diet. High-protein diets may cause abnormally high BUN levels while very low-protein diets can cause an abnormally low BUN. A wide variety ... a health practitioner will look at ...

  10. Overwinter changes in urea nitrogen:creatinine and cortisol:creatinine ratios in urine from Banks Island Peary caribou

    Directory of Open Access Journals (Sweden)

    Nicholas C. Larter

    2000-04-01

    Full Text Available Over 200 snow urine samples were collected from Banks Island Peary caribou between March 1993 and May 1998. Most (n = 146 samples were collected during 3 time periods in 5 successive years: early winter (3 November-3 December, mid-winter (9 February-1 March, and late-winter (23 April-2 May. We determined the ratios of urea nitrogen:creatinine (U:C and cortisol:creatinine (C:C for each sample. U:C ratios had significant year, time, and year x time interaction effects. Mid-winter ratios were higher than early or late-winter ratios. U:C ratios ranged from 0.53 to 19.05 mg/mg, and were lowest in 1997-98. Five calf caribou sacrificed in February 1994 had significantly (P<0.02 higher U:C ratios than other caribou in mid-winter. Three adult male and 2 calf caribou sacrificed in November 1993 had U:C ratios similar to other caribou in early winter. Sacrificed caribou were in similar condition to animals that have been harvested for subsistent use in other years, not overly fat nor in an advanced state of starvation. U:C ratios for Peary caribou range from 10 to ca. 100-fold higher than those reported for barren-ground caribou; ratios > 60-fold higher than those indicative of prolonged undernutrition in barren-ground caribou were common. This difference is likely because the winter diet of Peary caribou has a higher crude protein content than that of barren-ground caribou. C:C ratios had significant year and year x time interaction effects, and were highest in 1996-97 and 1997-98. C:C ratios of sacrificed caribou were similar to those of other animals during early and mid-winter. C:C ratios for Peary caribou ranged from 0.0120 ug/mg to 0.2678 ug/mg; ratios indicative of morbidity in mule deer were common. C:C and U:C ratios from the same individuals were not correlated (R = -0.073. Monitoring U:C ratios of Banks Island Peary caribou may provide useful management information.

  11. Milk yield and blood urea nitrogen in crossbred cows grazing Leucaena leucocephala in a silvopastoral system in the Mexican tropics

    Directory of Open Access Journals (Sweden)

    Maria B. Bottini-Luzardo

    2016-09-01

    Full Text Available The aim of the study was to assess milk yields, estimate the intake of crude protein (CP and determine the concentrations of blood urea nitrogen (BUN in early post-partum crossbred cows grazing irrigated Leucaena leucocephala (leucaena in a silvopastoral system relative to those in an irrigated grass monoculture.  Twenty-four multiparous cows were randomly allotted at calving on the basis of previous milk yields to 2 grazing treatments: grass monoculture system (MS of Cynodon nlemfuensis (n=12; and an intensive silvopastoral system (ISS composed of leucaena and C. nlemfuensis (n=12.  Cows were supplemented with sorghum grain (ISS or a conventional concentrate (MS during milking to ensure availability of metabolizable energy (ME and CP required for milk production.  Mean estimated intake of leucaena was 5.1±1.3 kg DM/d and estimated CP intakes were 1,479±3.3 and 1,258±3.3 g/d for ISS and MS, respectively (P>0.05, while estimated intakes of ME were 161±1.3 and 131±1.4 MJ/d for ISS and MS, respectively (P<0.05.  Milk yields were 13.5 and 14.5 kg/cow/d for cows on ISS and MS, respectively (P>0.05.  Concentrations of BUN were 19.1 mg/dL for cows in ISS and 15.3 mg/dL for cows in MS (P<0.05.  We conclude that intake of leucaena and sorghum grain in an irrigated silvopastoral system was sufficient to substitute for expensive concentrate in the diets of lactating cows grazing irrigated grass monoculture.  However, the higher levels of BUN found in ISS suggest a lower efficiency of N utilization in this treatment.  Restricting consumption of leucaena might be a means of improving efficiency of its use and this warrants investigation. Keywords: Cattle, crude protein, Cynodon nlemfuensis, leucaena, tropical pasturesDOI: 10.17138/TGFT(4159-167

  12. EPDM Rubber Modified by Nitrogen Plasma Immersion Ion Implantation.

    Science.gov (United States)

    Kondyurin, Alexey

    2018-04-24

    Ethylene-propylene diene monomer rubber (EPDM) was treated by plasma immersion ion implantation (PIII) with nitrogen ions of 20 keV energy and fluence from 10 13 to 10 16 ions/cm². The Fourier-transform infrared attenuated total reflection spectra, atomic force microscopy and optical microscopy showed significant structure changes of the surface. The analysis of an interface of PIII treated EPDM rubber with polyurethane binder showed a cohesive character of the adhesion joint fracture at the presence of solvent and interpreted as covalent bond network formation between the PIII treated rubber and the adhesive.

  13. EPDM Rubber Modified by Nitrogen Plasma Immersion Ion Implantation

    Directory of Open Access Journals (Sweden)

    Alexey Kondyurin

    2018-04-01

    Full Text Available Ethylene-propylene diene monomer rubber (EPDM was treated by plasma immersion ion implantation (PIII with nitrogen ions of 20 keV energy and fluence from 1013 to 1016 ions/cm2. The Fourier-transform infrared attenuated total reflection spectra, atomic force microscopy and optical microscopy showed significant structure changes of the surface. The analysis of an interface of PIII treated EPDM rubber with polyurethane binder showed a cohesive character of the adhesion joint fracture at the presence of solvent and interpreted as covalent bond network formation between the PIII treated rubber and the adhesive.

  14. CN emission spectroscopy study of carbon plasma in nitrogen environment

    International Nuclear Information System (INIS)

    Abdelli-Messaci, S.; Kerdja, T.; Bendib, A.; Malek, S.

    2005-01-01

    Spectroscopic emission diagnostics of a carbon plasma created by an excimer KrF laser pulse at three laser fluences (12, 25 and 32 J/cm 2 ) is performed under nitrogen ambient at pressures of 0.5 and 1 mbar. By following the time evolution of the radical CN spectral emission profiles, we notice, at a certain distance from the target surface, the existence of twin peaks for the time of flight distribution. This double structure depends on laser fluence and gas pressure parameters. The first peak moves forward in relation with the plasma expansion whereas the second peak moves backward and it is attributed to CN species undergoing oscillations or reflected shocks

  15. Nitrogen storage and distribution and reuse of 15N-urea applied in autumn on different branch leaves of winter Jujube (Zizyphus jujuba Mill. var. inermis Rehd) trees

    International Nuclear Information System (INIS)

    Zhao Dengchao; Jiang Yuanmao; Peng Futian; Zhang Xu; Sui Jing; He Naibo

    2007-01-01

    The effectiveness of foliage spraying with urea to augment the seasonal internal cycling of N in winter Jujube was studied. Different branches leaves of 6-year-old trees were painted with 5% abundance of 15 N-urea solution after fruit harvesting. Results showed that 15 N was detected in all the tree organs during the dormant season. In the following year 15 N was also detected in new growth organs (deciduous spurs, leaves and flowers). The treated branches and adjacent organs were the main sinks of Nitrogen in the dormant season. Ndff% in the treated branches was significantly decreased during dormant season. And a decrease of 59.13% was observed in the new growth branch treated and 60.05% in the perennial branches. Reserved nitrogen was reused for initial growth (leaves and deciduous spurs). 15 N stored in perennial organs also remobilized to sustain new growth of treated branches. It is different from the treated new growth branch, 15 N stored in the treated perennial branches is not only transported for new organs growth, but also for roots growth. (authors)

  16. Hierarchically porous nitrogen-doped carbon derived from the activation of agriculture waste by potassium hydroxide and urea for high-performance supercapacitors

    Science.gov (United States)

    Zou, Kaixiang; Deng, Yuanfu; Chen, Juping; Qian, Yunqian; Yang, Yuewang; Li, Yingwei; Chen, Guohua

    2018-02-01

    Nitrogen-doped carbon with an ultra-high specific surface area and a hierarchically interconnected porous structure is synthesized in large scale from a green route, that is, the activation of bagasse via a one-step method using KOH and urea. KOH and urea play a synergistic effect for the enhancement of the specific surface area and the modification of pore size of the as-prepared material. Benefiting from the multiple synergistic roles originated from an ultra-high specific area (2905.4 m2 g-1), a high porous volume (2.05 mL g-1 with 75.6 vol% micropores, which is an ideal proportion of micropores for obtaining high specific capacitance), a suitable nitrogen content (2.63 wt%), and partial graphitization, the hierarchically interconnected porous N-doped carbon exhibits an excellent electrochemical performance with a high specific capacitance (350.8, 301.9, and 259.5 F g-1 at 1.0 A g-1 in acidic, alkaline, and neutral electrolytes, respectively), superior rate capability and excellent cycling stability (almost no capacitance loss up to 5000 cycles). Furthermore, the symmetric device assembled by this material achieves high energy densities of 39.1 and 23.5 Wh kg-1 at power densities of 1.0 and 20 kW kg-1, respectively, and exhibits an excellent long-term cycling stability (with capacitance retention above 95.0% after 10 000 cycles).

  17. Depth distribution of nitrogen in silicon from plasma ion implantation

    International Nuclear Information System (INIS)

    Vajo, J.J.; Williams, J.D.; Wei, R.; Wilson, R.G.; Matossian, J.N.

    1994-01-01

    Plasma Ion Implantation (PII) is an ion implantation technique that eliminates the line-of-sight restriction of conventional ion-beam implantation and therefore allows for cost effective surface modification of large-scale objects or large-number of small-scale objects. In PII, a part to be implanted is immersed in a low-pressure (10 -4 --10 -5 Torr), partially-ionized plasma that surrounds the part with a plasma sheath. The part is negatively pulse biased up to 100 keV using a repetitive train (100--1,000 Hz) of short-duration (10--40 μsec) voltage pulses. The applied voltage develops across the sheath and accelerates plasma ions into the surface, implanting them omnidirectionally and simultaneously over the entire surface of the part. The depth distribution of the implanted ions influences the extent and type of surface modification achieved and depends upon many factors. These include three rise and fall time of the voltage-pulse waveform, the voltage-pulse amplitude, the ion specie, the ion density, and the temperature of the target. Understanding the contributions to the depth distribution from each of these factors will enable prediction of conditions that will be useful for implantation of large complex parts. To investigate the contributions to the measured depth distributions from these factors nitrogen, predominantly as N + 2 , has been implanted into silicon using PII at 50 and 100 keV (25 and 50 keV per N atom). The implanted depth distributions have been determined using secondary ion mass spectroscopy and Auger electron spectroscopy depth profiling. The distributions differ from the typical, approximately Gaussian, profiles that result from conventional mass selected monoenergetic ion beam implantation. In comparison with ion beam implants and numerical simulations the profiles appear ''filled-in'' with an approximately constant nitrogen concentration for depths less than the expected average ion range

  18. Kinetics of the urea-induced dissociation of human plasma alpha-2-macroglobulin as measured by small-angle neutron scattering

    DEFF Research Database (Denmark)

    Sjöberg, B.; Pap, S.; Järnberg, S.-E.

    1991-01-01

    The kinetics of the urea-induced dissociation of human plasma alpha-2-macroglobulin into two half-molecular fragments was investigated at 21.0-degrees-C by using small-angle neutron scattering. The relative change in molecular mass that occurs upon dissociation was monitored by recording the forw...

  19. Urea and short-chain fatty acids metabolism in Holstein cows fed a low-nitrogen grass-based diet

    DEFF Research Database (Denmark)

    Røjen, B A; Lund, P; Kristensen, N B

    2008-01-01

    Three ruminally cannulated and multicatheterised lactating dairy cows were used to investigate the effect of different supplement strategies to fresh clover grass on urea and short-chain fatty acid (SCFA) metabolism in a zero-grazing experiment with 24-h blood and ruminal samplings....

  20. Plasma-polymerized hexamethyldisilazane treated by nitrogen plasma immersion ion implantation technique

    Energy Technology Data Exchange (ETDEWEB)

    Honda, R Y; Mota, R P; Batocki, R G S; Santos, D C R; Nicoleti, T; Kostov, K G; Kayama, M E; Algatti, M A [Laboratorio de Plasma, Faculdade de Engenharia, UNESP, Av. Dr Ariberto Pereira da Cunha-333, 12516-410, Guaratingueta, SP (Brazil); Cruz, N C [Laboratorio de Plasmas Tecnologicos, Unidade Diferenciada, UNESP, Av. Tres de Marco-511, 18085-180, Sorocaba, SP (Brazil); Ruggiero, L, E-mail: honda@feg.unesp.b [Faculdade de Ciencias, UNESP, Av. Luis E. Carrijo Coube 14-1, 17033-360, Bauru, SP (Brazil)

    2009-05-01

    This paper describes the effect of nitrogen Plasma Immersion Ion Implantation (PIII) on chemical structure, refraction index and surface hardness of plasma-polymerized hexamethyldisilazane (PPHMDSN) thin films. Firstly, polymeric films were deposited at 13.56 MHz radiofrequency (RF) Plasma Enhanced Chemical Vapour Deposition (PECVD) and then, were treated by nitrogen PIII from 15 to 60 min. Fourier Transformed Infrared (FTIR) spectroscopy was employed to analyse the molecular structure of the samples, and it revealed that vibrations modes at 3350 cm{sup -1}, 2960 cm{sup -1}, 1650 cm{sup -1}, 1250 cm{sup -1} and 1050 cm{sup -1} were altered by nitrogen PIII. Visible-ultraviolet (vis-UV) spectroscopy was used to evaluate film refractive index and the results showed a slight increase from 1.6 to 1.8 following the implantation time. Nanoindentation revealed a surface hardness rise from 0.5 to 2.3 GPa as PIII treatment time increased. These results indicate nitrogen PIII is very promising in improving optical and mechanical properties of PPHMDSN films.

  1. Microwave plasma-assisted photoluminescence enhancement in nitrogen-doped ultrananocrystalline diamond film

    Directory of Open Access Journals (Sweden)

    Yu Lin Liu

    2012-06-01

    Full Text Available Optical properties and conductivity of nitrogen-doped ultrananocrystal diamond (UNCD films were investigated following treatment with low energy microwave plasma at room temperature. The plasma also generated vacancies in UNCD films and provided heat for mobilizing the vacancies to combine with the impurities, which formed the nitrogen-vacancy defect centers. The generated color centers were distributed uniformly in the samples. The conductivity of nitrogen-doped UNCD films treated by microwave plasma was found to decrease slightly due to the reduced grain boundaries. The photoluminescence emitted by the plasma treated nitrogen-doped UNCD films was enhanced significantly compared to the untreated films.

  2. Reversal by prostaglandin E2 infusion of the effects of indomethacin on the excretion of nitrogenous compounds in the rat.

    OpenAIRE

    Rowe, D. J.; Gedeon, G.

    1983-01-01

    Rats were treated with Indomethacin (Indo; 2 mg/kg/d) with or without concomitant infusion of prostaglandin (PG)E2 (100 micrograms/d) to investigate the effects of inhibition of PG synthesis and PG replacement on the urinary excretion of total nitrogenous compounds, urea and creatinine and on the plasma concentration of urea and creatinine. The results indicated: (1) Indo significantly reduced the urine excretion of nitrogen, urea and creatinine within 48 hours of drug administration. (2) Thi...

  3. Nitrogen budget of 15 N-Labelled urea applied to dry land wheat as affected by seasonal rainfall

    International Nuclear Information System (INIS)

    Abdel-Monem, M.A.; Ryan, J.; Christianson, B.

    1999-01-01

    Field trial was conducted at two locations of the semi-arid region of Morocco with an objective of estimating the N balance for the applied urea to wheat under two different agroecological zones. N-15 labelled urea was applied in microplots (1 m x 1 m) at tillering stage at rates of 0,40,80, and 120 kg/ha. Soil and plant samples were analyzed for N-15 excess. An average of 45% increase in grain yield of wheat was due to fertilization with 60 kg N/ha. Recovery of N-15 labelled N ranged between 28.8 and 45.1% for the rate of 40 kg N/ha. Results suggested that efficiency of the applied fertilizer is governed by seasonal rainfall and soil properties

  4. Construction of a nitrogen laser for plasma diagnostics

    International Nuclear Information System (INIS)

    Ishiekwene, G.C.

    1994-07-01

    The challenge faced in finding new sources of energy to bridge the gap between the availability and demand of energy is difficult to be overemphasized. Nuclear fusion seems to provide a potentially limitless source of energy which offers a bright prospect for solving this problem. Although an elaborate programme in fusion may be beyond the economic reach of most third world countries, some modest experiments are necessary to provide an indigenous expertise capable of enhancing international fusion studies. In order to initiate experimental research sufficient for plasma studies at an affordable cost to developing countries, this paper illustrates the construction of a simple, low cost, high power nitrogen laser and investigates some of its performance characteristics. Also, the laser is utilized as a source of illumination in the techniques of shadowgraphy. A series of shadowgrams depicting the temporal development of the plasma discharge is presented. The constructed laser is found to be cost-effective and useful in small-scale researches in laser-plasma diagnostics. (author). 6 refs, 5 figs

  5. Nitrogen

    Science.gov (United States)

    Apodaca, L.E.

    2010-01-01

    Ammonia was produced by 13 companies at 23 plants in 16 states during 2009. Sixty percent of all U.S. ammonia production capacity was centered in Louisiana. Oklahoma and Texas because of those states' large reserves of natural gas, the dominant domestic feedstock. In 2009, U.S. producers operated at about 83 percent of their rated capacity (excluding plants that were idle for the entire year). Five companies — Koch Nitrogen Co.; Terra Industries Inc.; CF Industries Inc.; PCS Nitrogen Inc. and Agrium Inc., in descending order — accounted for 80 percent of the total U.S. ammonia production capacity. U.S. production was estimated to be 7.7 Mt (8.5 million st) of nitrogen (N) content in 2009 compared with 7.85 Mt (8.65 million st) of N content in 2008. Apparent consumption was estimated to have decreased to 12.1 Mt (13.3 million st) of N, a 10-percent decrease from 2008. The United States was the world's fourth-ranked ammonia producer and consumer following China, India and Russia. Urea, ammonium nitrate, ammonium phosphates, nitric acid and ammonium sulfate were the major derivatives of ammonia in the United States, in descending order of importance.

  6. Generation of various radicals in nitrogen plasma and their behavior in media

    International Nuclear Information System (INIS)

    Uhm, Han S.

    2015-01-01

    Research on the generation of radicals in nitrogen plasma shows that the most dominant radicals are excited nitrogen molecules in the metastable state of N 2 (A 3 ∑ u + ). Hydroxyl molecules are generated from the dissociation of water molecules upon contact with excited nitrogen molecules. The estimated densities of various radicals in nitrogen plasma with an electron temperature of 1 eV are presented in this study. The behavior of these radicals in media is also investigated. Excited nitrogen molecules in the N 2 (A 3 ∑ u + ) state from a plasma jet are injected into water, after which the molecules disappear instantaneously within a few tens of nm, producing hydroxyl molecules. Hydrogen peroxide, hydrogen dioxide, and nitrogen monoxide molecules can diffuse much deeper into water, implying the possibility that a chemical reaction between hydrogen dioxide and nitrogen monoxide molecules produces hydroxyl molecules in deep water, even though density in this case may not be very high

  7. Influence of N-15 labelled urea and azotobacter on corn yield and nitrogen budget as affected by organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, S M; Abdelmonem, M A [Soil and Water Dept., Atomic Energy Authority, Cairo, (Egypt)

    1995-10-01

    As sandy soils of Egypt are poor in their chemical and physical properties, their fertilization with chemical or biological fertilizer is essential. The reported greenhouse experiment was conducted, using sandy soil of Egypt to evaluate the impact of urea fertilizer, applied alone combined with nitrification inhibitors (DCD) or (N-serve) on (corn yield and N-losses) as compared with inoculation with azotobacter under organic matter treatment as soil amendment. Total dry matter was recorded, while N-uptake by corn, and N-recovery due to inoculation with azotobacter was determined using N-15 dilution technique. Data obtained indicated that, application of DCD or N-serve with urea increased corn dry matter weight as well N-15 recovery. Significant increase in N-recovery was obtained due to nitrification inhibitor application and azotobacter inoculation. N-15 losses were reduced due to application of DCD and N-serve from 45% and respectively. Use of bio fertilizers and nitrification inhibitors could play an important role in corn production in sandy soil, as well as decrease the losses of applied N-fertilizers. fig., 3 tabs.

  8. Influence of N-15 labelled urea and azotobacter on corn yield and nitrogen budget as affected by organic matter

    International Nuclear Information System (INIS)

    Soliman, S.M.; Abdelmonem, M.A.

    1995-01-01

    As sandy soils of Egypt are poor in their chemical and physical properties, their fertilization with chemical or biological fertilizer is essential. The reported greenhouse experiment was conducted, using sandy soil of Egypt to evaluate the impact of urea fertilizer, applied alone combined with nitrification inhibitors (DCD) or (N-serve) on (corn yield and N-losses) as compared with inoculation with azotobacter under organic matter treatment as soil amendment. Total dry matter was recorded, while N-uptake by corn, and N-recovery due to inoculation with azotobacter was determined using N-15 dilution technique. Data obtained indicated that, application of DCD or N-serve with urea increased corn dry matter weight as well N-15 recovery. Significant increase in N-recovery was obtained due to nitrification inhibitor application and azotobacter inoculation. N-15 losses were reduced due to application of DCD and N-serve from 45% and respectively. Use of bio fertilizers and nitrification inhibitors could play an important role in corn production in sandy soil, as well as decrease the losses of applied N-fertilizers. fig., 3 tabs

  9. [Effects of different nitrogen application rates on 15N-urea absorption, utilization, loss and fruit yield and quality of dwarf apple].

    Science.gov (United States)

    Chen, Qian; Ding, Ning; Peng, Ling; Ge, Shun Feng; Jiang, Yuan Mao

    2017-07-18

    Seven-year-old 'Yanfu3'/M 26 /M. hupehensis Rehd. seedlings and 15 N trace technique were used to explore the characteristics of 15 N-urea absorption, utilization, loss and fruit yield and quality under different nitrogen application rates (N 100 , N 200 and N 300 ). The main results were as follows: the plant growth, 15 N absorption, utilization and loss differed significantly under different treatments. The plant leaf chlorophyll content (SPAD value), photosynthetic rate (P n ), total N content of leaves and the biomass, as well as the root-shoot ratio of N 200 treatment were obviously higher than the N 100 and N 300 treatments. Significant differences were observed in the 15 N derived from fertilizer (Ndff value) of different organs under different nitrogen application rates. The Ndff of fruits (flowers), leaves, one-year-old branch, and perennial branches in each measurement period was N 100 >N 200 >N 300 , while that of the roots at full-bloom and spring shoot growing slowly stage was N 100 >N 200 >N 300 , and in a trend of N 200 >N 100 >N 300 at autumn shoot growing stage, fruit rapid-swel-ling stage and fruit maturity stage. At fruit maturity stage, plant 15 N nitrogen utilization ratio of N 200 treatment was 23.6%, which was obviously higher than the N 100 (16.3%) and N 300 (14.4%) treatments, with the 15 N loss rate of 56.4%, obviously lower than the N 100 (60.6%) and N 300 (66.1%) treatments. There were significant differences among the treatments in fruit mass, yield per plant, soluble solid, fruit firmness, soluble sugar, titratable acids and sugar-acid ratio of different nitrogen rates, and the N 200 treatment showed the best performance, followed by the N 300 treatment, and then the N 100 treatment.

  10. Control of work function of graphene by plasma assisted nitrogen doping

    International Nuclear Information System (INIS)

    Akada, Keishi; Terasawa, Tomo-o; Imamura, Gaku; Obata, Seiji; Saiki, Koichiro

    2014-01-01

    Nitrogen doping is expected to provide several intriguing properties to graphene. Nitrogen plasma treatment to defect-free and defective highly oriented pyrolytic graphite (HOPG) samples causes doping of nitrogen atom into the graphene layer. Nitrogen atoms are initially doped at a graphitic site (inside the graphene) for the defect-free HOPG, while doping to a pyridinic or a pyrrolic site (edge of the graphene) is dominant for the defective HOPG. The work function of graphene correlates strongly with the site and amount of doped nitrogen. Nitrogen atoms doped at a graphitic site lower the work function, while nitrogen atoms at a pyridinic or a pyrrolic site increase the work function. Control of plasma treatment time and the amount of initial defect could change the work function of graphite from 4.3 eV to 5.4 eV, which would open a way to tailor the nature of graphene for various industrial applications

  11. Estimate of production of gaseous nitrogen in the human body based on (15)N analysis of breath N2 after administration of [(15)N2]urea.

    Science.gov (United States)

    Junghans, Peter

    2013-01-01

    After oral administration of [(15)N2]urea (1.5 mmol, 95 atom% (15)N), we found that breath N2 was significantly (15)N-labelled. The result suggests that molecular nitrogen in breath must be partly produced endogenously. Based on a metabolic model, the endogenous N2 production was estimated to be 0.40±0.25 mmol kg(-1) d(-1) or 2.9±1.8 % of the total (urinary and faecal) N excretion in fasted healthy subjects (n=4). In patients infected with Helicobacter pylori (n=5), the endogenous N2 production was increased to 1.24±0.59 mmol kg(-1) d(-1) or 9.0±4.3 % of the total N excretion compared to the healthy controls (pexchange measurements may be affected by endogenously produced nitrogen, especially in metabolic situations with elevated nitrosation, for instance in oxidative and nitrosative stress-related diseases such as H. pylori infections.

  12. ROW METHOD OF SUGAR BEET (BETA VULGARIS L. FERTILIZATION WITH MULTICOMPONENT FERTILIZER BASED ON UREA-AMMONIUM NITRATE SOLUTION AS A WAY TO INCREASE NITROGEN EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Przemysław BARŁÓG

    2010-12-01

    Full Text Available Sugar beet is the main crop commonly cultivated for sugar production in temperate regions of the World. Actual yields in main Central Europe producing countries are much lower, due to many limiting factors. Among them, nutrients supply is of great value, especially referring to efficiency of nitrogen, which is generally low. In the conducted study two methods of nitrogen application were compared (i broadcast of calcium saltpeter and (ii row application of the multicomponent fertilizer based on urea-ammonium-nitrate (UAN solution. The basic amount of the applied N was 75 kg ha-1. The highest yields of both taproots and refined sugar were harvested on the plot receiving 75 kg N-1 as UAN liquid multicomponent fertilizer and 50% of the recommended P and K rates. The positive effects of row application of liquid N fertilizer on taproot and sugar yields were also corroborated by high values of indices of agronomic efficiency for both N as well as P and K. However this method of sugar beets fertilization has some possibilities, as indicated by still high contents of melassogenic substances.

  13. Interaction of dense nitrogen plasma with SS304 surface using APF plasma focus device

    Science.gov (United States)

    Afrashteh, M.; Habibi, M.; Heydari, E.

    2012-04-01

    The nitridation of SS304 surfaces is obtained by irradiating nitrogen ions from Amirkabir plasma focus device, which use multiple focus deposition shots at optimum distance 10 cm from the anode. The Vickers Micro-Hardness values are improved more than twice for the nitrided samples comparing to the nonnitrided ones. The X-ray diffraction (XRD) analysis is carried out in order to explore the phase changes in the near surface structure of the metals. The results of Scanning Electron Microscopy (SEM) indicate changes in surface morphology which are the emergence of smooth and uniform film on the surface of the nitrided metals.

  14. Technical note: Nitrogen isotopic fractionation can be used to predict nitrogen-use efficiency in dairy cows fed temperate pasture.

    Science.gov (United States)

    Cheng, L; Sheahan, A J; Gibbs, S J; Rius, A G; Kay, J K; Meier, S; Edwards, G R; Dewhurst, R J; Roche, J R

    2013-12-01

    The objective of this study was to investigate the relationship between nitrogen isotopic fractionation (δ(15)N) and nitrogen-use efficiency (milk nitrogen/nitrogen intake; NUE) in pasture-fed dairy cows supplemented with increasing levels of urea to mimic high rumen degradable protein pastures in spring. Fifteen cows were randomly assigned to freshly cut pasture and either supplemented with 0, 250, or 336 g urea/d. Feed, milk, and plasma were analyzed for δ(15)N, milk and plasma for urea nitrogen concentration, and plasma for ammonia concentration. Treatment effects were tested using ANOVA and relationships between variables were established by linear regression. Lower dry matter intake (P = 0.002) and milk yield (P = 0.002) occurred with the highest urea supplementation (336 g urea/d) compared with the other two treatments. There was a strong linear relationship between milk δ(15)N - feed δ(15)N and NUE: [NUE (%) = 58.9 - 10.17 × milk δ(15)N - feed δ(15)N (‰) (r(2) = 0.83, P < 0.001, SE = 1.67)] and between plasma δ(15)N - feed δ(15)N and NUE: [NUE (%) = 52.4 - 8.61 × plasma δ(15)N - feed δ(15)N (‰) (r(2) = 0.85, P < 0.001, SE = 1.56)] . This study confirmed the potential use of δ(15)N to predict NUE in cows consuming different levels of rumen degradable protein.

  15. Investigation on the mechanism of nitrogen plasma modified PDMS bonding with SU-8

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chengxin; Yuan, Yong J., E-mail: yongyuan@swjtu.edu.cn

    2016-02-28

    Graphical abstract: - Highlights: • Different nitrogen plasma processes modified PDMS bonding with SU-8 had been studied. • The effect of nitrogen plasma modification would produce the best result and the recovery of PDMS hydrophobicity could be delayed. - Abstract: Polydimethylsiloxane (PDMS) and SU-8 are both widely used for microfluidic system. However, it is difficult to permanently seal SU-8 microfluidic channels using PDMS with conventional methods. Previous efforts of combining these two materials mainly employed oxygen plasma modified PDMS. The nitrogen plasma modification of PDMS bonding with SU-8 is rarely studied in recent years. In this work, the mechanism of nitrogen plasma modified PDMS bonding with SU-8 was investigated. The fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and contact angle of a water droplet were used to analyze the nitrogen plasma modified surface and the hydrophilic stability of PDMS samples. Pull-off tests were used for estimating the bonding effect of interface between nitrogen plasma modified PDMS and SU-8.

  16. Construction of control and instrumentation devices of high voltage power supply of double chamber plasma nitrogen

    International Nuclear Information System (INIS)

    Saminto; Eko Priyono; Sugeng Riyanto

    2013-01-01

    A control and instrumentation devices of high voltage power supply of double chamber plasma nitrogen have been made. This device consists of the software and hardware component. Hardware component consists of SCR phase angle controller LPC-50HDA type, T100MD1616+ PLC, high voltage transformer and voltage rectifier system. Software component used a LADDER program and TBasic serves to control of the high voltage output. The components in these devices have been tested in the double chamber plasma nitrogen. Its performance meet with the design criteria that can supply of plasma nitrogen operation voltage in the range 290 Vdc to 851 Vdc with glow discharge current 0.4 A to 1.4 A. In general it can be said that the control and instrumentation devices of high voltage power supply is ready for use at the double chamber plasma nitrogen device. (author)

  17. Comparison study of nitrogen and argon processing in a plasma arc centrifugal treatment system

    International Nuclear Information System (INIS)

    Shuey, M.; Tsuji, Y.

    2000-01-01

    Recent testing performed at the plasma research center of Retech Services, Inc. compared nitrogen with argon as plasma gas in the processing of simulated wastes. The testing took place in a full-scale production PACT system under a cooperative research and development study between Retech Services Inc. and Toyo Engineering Corporation. This study shows that simulated waste can be processed by both nitrogen and argon plasmas. Heat losses to the torch nozzle were significantly lower with argon and should be studied further. Both argon and nitrogen plasma were able to process feeds containing both metals and oxides. Some of the drawbacks to using argon plasma are cost, higher volume flow rates, and dual mode torch nozzle erosion. (authors)

  18. The urea cycle disorders.

    Science.gov (United States)

    Helman, Guy; Pacheco-Colón, Ileana; Gropman, Andrea L

    2014-07-01

    The urea cycle is the primary nitrogen-disposal pathway in humans. It requires the coordinated function of six enzymes and two mitochondrial transporters to catalyze the conversion of a molecule of ammonia, the α-nitrogen of aspartate, and bicarbonate into urea. Whereas ammonia is toxic, urea is relatively inert, soluble in water, and readily excreted by the kidney in the urine. Accumulation of ammonia and other toxic intermediates of the cycle lead to predominantly neurologic sequelae. The disorders may present at any age from the neonatal period to adulthood, with the more severely affected patients presenting earlier in life. Patients are at risk for metabolic decompensation throughout life, often triggered by illness, fasting, surgery and postoperative states, peripartum, stress, and increased exogenous protein load. Here the authors address neurologic presentations of ornithine transcarbamylase deficiency in detail, the most common of the urea cycle disorders, neuropathology, neurophysiology, and our studies in neuroimaging. Special attention to late-onset presentations is given. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  19. Effect of alternative pathway therapy on branched chain amino acid metabolism in urea cycle disorder patients.

    Science.gov (United States)

    Scaglia, Fernando; Carter, Susan; O'Brien, William E; Lee, Brendan

    2004-04-01

    Urea cycle disorders (UCDs) are a group of inborn errors of hepatic metabolism caused by the loss of enzymatic activities that mediate the transfer of nitrogen from ammonia to urea. These disorders often result in life-threatening hyperammonemia and hyperglutaminemia. A combination of sodium phenylbutyrate and sodium phenylacetate/benzoate is used in the clinical management of children with urea cycle defects as a glutamine trap, diverting nitrogen from urea synthesis to alternatives routes of excretion. We have observed that patients treated with these compounds have selective branched chain amino acid (BCAA) deficiency despite adequate dietary protein intake. However, the direct effect of alternative therapy on the steady state levels of plasma branched chain amino acids has not been well characterized. We have measured steady state plasma branched chain and other essential non-branched chain amino acids in control subjects, untreated ornithine transcarbamylase deficiency females and treated null activity urea cycle disorder patients in the fed steady state during the course of stable isotope studies. Steady-state leucine levels were noted to be significantly lower in treated urea cycle disorder patients when compared to either untreated ornithine transcarbamylase deficiency females or control subjects (Purea cycle disorder patients. These findings suggest that better titration of protein restriction could be achieved with branched chain amino acid supplementation in patients with UCDs who are on alternative route therapy.

  20. Risk Stratification of Acute Kidney Injury Using the Blood Urea Nitrogen/Creatinine Ratio in Patients With Acute Decompensated Heart Failure.

    Science.gov (United States)

    Takaya, Yoichi; Yoshihara, Fumiki; Yokoyama, Hiroyuki; Kanzaki, Hideaki; Kitakaze, Masafumi; Goto, Yoichi; Anzai, Toshihisa; Yasuda, Satoshi; Ogawa, Hisao; Kawano, Yuhei

    2015-01-01

    Risk stratification of acute kidney injury (AKI) is important for acute decompensated heart failure (ADHF). The aim of this study was to determine whether clinical markers, such as the blood urea nitrogen/creatinine ratio (BUN/Cr) or BUN or creatinine values alone, stratify the risk of AKI for mortality. In all, 371 consecutive ADHF patients were enrolled in the study. AKI was defined as serum creatinine ≥0.3 mg/dl or a 1.5-fold increase in serum creatinine levels within 48 h. During ADHF therapy, AKI occurred in 99 patients; 55 patients died during the 12-month follow-up period. Grouping patients according to AKI and a median BUN/Cr at admission of 22.1 (non-AKI+low BUN/Cr, non-AKI+high BUN/Cr, AKI+low BUN/Cr, and AKI+high BUN/Cr groups) revealed higher mortality in the AKI+high BUN/Cr group (log-rank test, Phigh BUN/Cr and mortality, whereas the association with AKI+low BUN/Cr did not reach statistical significance. When patients were grouped according to AKI and median BUN or creatinine values at admission, AKI was associated with mortality, regardless of BUN or creatinine. The combination of AKI and elevated BUN/Cr, but not BUN or creatinine individually, is linked with an increased risk of mortality in ADHF patients, suggesting that the BUN/Cr is useful for risk stratification of AKI.

  1. Limited Seed and Seed Yield Response of Calendula to Applied Nitrogen Does Not Justify Risk of Environmental Damage from High Urea Application Rates

    Directory of Open Access Journals (Sweden)

    Jane M. F. Johnson

    2018-03-01

    Full Text Available Calendula (Calendula officinalis L. seed, due to its high calendic acid content, is recognized as a potential environmentally safe substitute for volatile organic compounds. Agronomic guidelines for nitrogen (N management to produce calendula seed oil on a commercial scale are limited. Post-harvest soil N has the potential to move off-farm and contribute to water quality degradation (e.g., hypoxia in the Gulf of Mexico. Establishing N management guidelines should consider agronomic response and potential environmental risk. Calendula seed and oil yield, oil content, harvest index, N use, seed N use efficiency, oil N use efficiency, agronomic efficiency, vegetative growth, and the amount of residual soil-N following harvest response to five urea N rates (0, 34, 67, 134, and 202 kg N ha−1 were assessed in a replicated field study repeated for two growing seasons. Seed yield increased with N rate, but because of the low N conversion efficiency, there appeared to be minimal yield gains in applying N beyond 34 kg ha−1. The lowest amount of soil-N left underutilized in the soil was predicted to occur at 39 kg N ha−1 and was adequate for seed and seed oil commercial calendula production on a Mollisol in the Northern Midwest United States.

  2. Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage.

    Science.gov (United States)

    Batista, E D; Detmann, E; Titgemeyer, E C; Valadares Filho, S C; Valadares, R F D; Prates, L L; Rennó, L N; Paulino, M F

    2016-01-01

    Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers () consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 ± 9 kg) were used in a 5 × 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [NN]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected ( ≥ 0.37) by supplementation, but supplementation did increase ruminal NDF digestion ( Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation ( urea entry rate and tended ( = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended ( = 0.07) to be increased by supplementation, and RUP provision also tended ( = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater ( urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis.

  3. Evaluation on nitrogen oxides and nanoparticle removal and nitrogen monoxide generation using a wet-type nonthermal plasma reactor

    Science.gov (United States)

    Takehana, Kotaro; Kuroki, Tomoyuki; Okubo, Masaaki

    2018-05-01

    Nitrogen oxides (NOx) emitted from power plants and combustion sources cause air pollution problems. Selective catalytic reduction technology is remarkably useful for NOx removal. However, there are several drawbacks such as preparation of reducing agents, usage of harmful heavy metals, and higher cost. On the other hand, trace NO is a vasodilator agent and employed in inhalation therapies for treating pulmonary hypertension in humans. Considering these factors, in the present study, a wet-type nonthermal plasma reactor, which can control NOx and nanoparticle emissions and generate NO, is investigated. The fundamental characteristics of the reactor are investigated. First, the experiment of nanoparticle removal is carried out. Collection efficiencies of over 99% are achieved for nanoparticles at 50 and 100 ml min‑1 of liquid flow rates. Second, experiments of NOx removal under air atmosphere and NOx generation under nitrogen atmosphere are carried out. NOx-removal efficiencies of over 95% under the air plasma are achieved in 50–200 ml min‑1 liquid flow rates. Moreover, under nitrogen plasma, NOx is generated, of which the major portion is NO. For example, NO concentration is 25 ppm, while NOx concentration is 31 ppm at 50 ml min‑1 liquid flow rate. Finally, experiments of NO generation under the nitrogen atmosphere with or without flowing water are carried out. When water flows on the inner surface of the reactor, approximately 14 ppm of NO is generated. Therefore, NO generation requires flowing water. It is considered that the reaction of N and OH, which is similar to the extended Zeldovich mechanism, could occur to induce NO formation. From these results, it is verified that the wet-type plasma reactor is useful for NOx removal and NO generation under nitrogen atmosphere with flowing water.

  4. Industrial applications of plasma, microwave and ultrasound techniques : nitrogen-fixation and hydrogenation reactions

    NARCIS (Netherlands)

    Hessel, V.; Cravotto, G.; Fitzpatrick, P.; Patil, B.S.; Lang, J.; Bonrath, W.

    2013-01-01

    The MAPSYN project (Microwave, Acoustic and Plasma assisted SYNtheses) aims at nitrogen-fixation reactions intensified by plasma catalysis and selective hydrogenations intensified by microwaves, possibly assisted by ultrasound. Energy efficiency is the key motif of the project and the call of the

  5. Thermal Plasma Spheroidization of High-Nitrogen Stainless Steel Powder Alloys Synthesized by Mechanical Alloying

    Science.gov (United States)

    Razumov, Nikolay G.; Popovich, Anatoly A.; Wang, QingSheng

    2018-03-01

    This paper presents the results of experimental studies on the treatment of Fe-23Cr-11Mn-1N high-nitrogen stainless steel powder alloys, synthesized by the mechanical alloying (MA) of elemental powders in the flow of a thermal plasma. Fe-23Cr-11Mn-1N high-nitrogen stainless steel powder alloys were prepared by MA in the attritor under an argon atmosphere. For spheroidization of Fe-23Cr-11Mn-1N high-nitrogen stainless steel powder alloys, the TekSphero 15 plant manufactured by Tekna Plasma Systems Inc was used. The studies have shown the possibility of obtaining Fe-23Cr-11Mn-1N high-nitrogen spherical powders steel alloys from the powder obtained by MA. According to the results of a series of experiments, it was found that the results of plasma spheroidization of powders essentially depend on the size of the fraction due to some difference in the particle shape and flowability, and on the gas regime of the plasma torch. It is established that during the plasma spheroidization process, some of the nitrogen leaves the alloy. The loss rate of nitrogen depends on the size of the initial particles.

  6. Hepatic urea biosynthesis in the euryhaline elasmobranch Carcharhinus leucas.

    Science.gov (United States)

    Anderson, W Gary; Good, Jonathan P; Pillans, Richard D; Hazon, Neil; Franklin, Craig E

    2005-10-01

    Plasma urea levels and hepatic urea production in the euryhaline bull shark, Carcharhinus leucas, acclimated to freshwater and seawater environments were measured. It was found that plasma urea concentration increased with salinity and that this increase was, in part, the result of a significant increase in hepatic production of urea. This study provides direct evidence that hepatic production of urea plays an important role in the osmoregulatory strategy of C. leucas. (c) 2005 Wiley-Liss, Inc.

  7. Effect of feed-gas humidity on nitrogen atmospheric-pressure plasma jet for biological applications.

    Science.gov (United States)

    Stephan, Karl D; McLean, Robert J C; DeLeon, Gian; Melnikov, Vadim

    2016-11-14

    We investigate the effect of feed-gas humidity on the oxidative properties of an atmospheric-pressure plasma jet using nitrogen gas. Plasma jets operating at atmospheric pressure are finding uses in medical and biological settings for sterilization and other applications involving oxidative stress applied to organisms. Most jets use noble gases, but some researchers use less expensive nitrogen gas. The feed-gas water content (humidity) has been found to influence the performance of noble-gas plasma jets, but has not yet been systematically investigated for jets using nitrogen gas. Low-humidity and high-humidity feed gases were used in a nitrogen plasma jet, and the oxidation effect of the jet was measured quantitatively using a chemical dosimeter known as FBX (ferrous sulfate-benzoic acid-xylenol orange). The plasma jet using high humidity was found to have about ten times the oxidation effect of the low-humidity jet, as measured by comparison with the addition of measured amounts of hydrogen peroxide to the FBX dosimeter. Atmospheric-pressure plasma jets using nitrogen as a feed gas have a greater oxidizing effect with a high level of humidity added to the feed gas.

  8. Enhancement of electron field emission of vertically aligned carbon nanotubes by nitrogen plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wang, B.B. [College of Chemistry and Chemical Engineering, Chongqing University of Technology, 69 Hongguang Rd, Lijiatuo, Banan District, Chongqing 400054 (China); Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, NSW 2070 (Australia); Cheng, Q.J. [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, NSW 2070 (Australia); Plasma Nanoscience, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Chen, X. [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Ostrikov, K., E-mail: kostya.ostrikov@csiro.au [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, NSW 2070 (Australia); Plasma Nanoscience, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)

    2011-09-22

    Highlights: > A new and custom-designed bias-enhanced hot-filament chemical vapor deposition system is developed to synthesize vertically aligned carbon nanotubes. > The carbon nanotubes are later treated with nitrogen plasmas. > The electron field emission characteristics of the carbon nanotubes are significantly improved after the nitrogen plasma treatment. > A new physical mechanism is proposed to interpret the improvement of the field emission characteristics. - Abstract: The electron field emission (EFE) characteristics from vertically aligned carbon nanotubes (VACNTs) without and with treatment by the nitrogen plasma are investigated. The VACNTs with the plasma treatment showed a significant improvement in the EFE property compared to the untreated VACNTs. The morphological, structural, and compositional properties of the VACNTs are extensively examined by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and energy dispersive X-ray spectroscopy. It is shown that the significant EFE improvement of the VACNTs after the nitrogen plasma treatment is closely related to the variation of the morphological and structural properties of the VACNTs. The high current density (299.6 {mu}A/cm{sup 2}) achieved at a low applied field (3.50 V/{mu}m) suggests that the VACNTs after nitrogen plasma treatment can serve as effective electron field emission sources for numerous applications.

  9. Enhancement of electron field emission of vertically aligned carbon nanotubes by nitrogen plasma treatment

    International Nuclear Information System (INIS)

    Wang, B.B.; Cheng, Q.J.; Chen, X.; Ostrikov, K.

    2011-01-01

    Highlights: → A new and custom-designed bias-enhanced hot-filament chemical vapor deposition system is developed to synthesize vertically aligned carbon nanotubes. → The carbon nanotubes are later treated with nitrogen plasmas. → The electron field emission characteristics of the carbon nanotubes are significantly improved after the nitrogen plasma treatment. → A new physical mechanism is proposed to interpret the improvement of the field emission characteristics. - Abstract: The electron field emission (EFE) characteristics from vertically aligned carbon nanotubes (VACNTs) without and with treatment by the nitrogen plasma are investigated. The VACNTs with the plasma treatment showed a significant improvement in the EFE property compared to the untreated VACNTs. The morphological, structural, and compositional properties of the VACNTs are extensively examined by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and energy dispersive X-ray spectroscopy. It is shown that the significant EFE improvement of the VACNTs after the nitrogen plasma treatment is closely related to the variation of the morphological and structural properties of the VACNTs. The high current density (299.6 μA/cm 2 ) achieved at a low applied field (3.50 V/μm) suggests that the VACNTs after nitrogen plasma treatment can serve as effective electron field emission sources for numerous applications.

  10. Substituição de uréia por cloreto de amônio em dietas de bovinos: digestibilidade, síntese de proteína microbiana, parâmetros ruminais e sanguíneos = Replacing urea with ammonium chloride in cattle diets: digestibility, synthesis of microbial protein, and rumen and plasma parameters

    Directory of Open Access Journals (Sweden)

    Roman David Castañeda

    2009-07-01

    Full Text Available Foram utilizados cinco bovinos machos, castrados, da raça Holandesa Preta e Branca, com 450 kg de peso vivo em um delineamento quadrado latino 5 x 5, sendo os tratamentos cinco níveis de substituição, 0, 25, 50, 75 e 100% de ureia por cloreto de amônio, como fontes de nitrogênio não-proteico da dieta. Houve redução linear (p 0,05 a excreção de alantoína e de derivados de purinas na urina, purinas absorvidas, síntese de compostos nitrogenados microbianos e eficiência de síntese de proteína microbiana. Houve queda linear (p 0,05 a concentração de amônia no rúmen. O cloreto de amônio pode ser utilizado como fonte de NNP para bovinos em níveis de até 1,4% da matéria seca total da dieta.Five Holstein steers weighting 450 kg were used in a 5 x 5 Latin square statistical design, where treatments consisted of five replacement levels: 0, 25, 50, 75 and 100% of urea by ammonium chloride, as non-protein nitrogen in the diet. There was a linear decrease (p 0.05 daily excretion of allantoin, purine derivatives, absorbed purines, as well as microbial nitrogen compounds and microbial efficiency synthesis. Rumen pH and plasma urea nitrogen decreased linearly (p 0.05 ruminal ammonia concentration as urea was replaced by ammonium chloride. Ammonium chloride can be used as a nonprotein nitrogen source in ruminant diets up to level of 1.4% of diet dry matter.

  11. Effect of urine urea nitrogen and protein intake adjusted by using the estimated urine creatinine excretion rate on the antiproteinuric effect of angiotensin II type I receptor blockers.

    Science.gov (United States)

    Chin, Ho Jun; Kim, Dong Ki; Park, Jung Hwan; Shin, Sung Joon; Lee, Sang Ho; Choi, Bum Soon; Kim, Suhnggwon; Lim, Chun Soo

    2015-01-01

    The aim of this study was to determine the role of protein intake on proteinuria in chronic kidney disease (CKD), as it is presently not conclusive. This is a subanalysis of data from an open-label, case-controlled, randomized clinical trial on education about low-salt diets (NCT01552954). We estimated the urine excretion rate of parameters in a day, adjusted by using the equation for estimating urine creatinine excretion, and analyzed the effect of urine urea nitrogen (UUN), as well as estimating protein intake on the level of albuminuria in hypertensive patients with chronic kidney disease. Among 174 participants from whom complete 24-h urine specimens were collected, the estimates from the Tanaka equation resulted in the highest accuracy for the urinary excretion rate of creatinine, sodium, albumin, and UUN. Among 227 participants, the baseline value of estimated urine albumin excretion (eUalb) was positively correlated with the estimated UUN (eUUN) or protein intake according to eUUN (P = 0.012 and P = 0.038, respectively). We were able to calculate the ratios of eUalb and eUUN in 221 participants and grouped them according to the ratio of eUUN during 16-wk trial period. The proportion of patients that achieved a decrement of eUalb ≥25% during 16 wk with an angiotensin II type I receptor blocker (ARB) medication was 80% (24 of 30) in group 1, with eUUN ratio ≤-25%; 82.2% (111 of 135) in group 2, with eUUN ratio between -25% and 25%; and 66.1% (37 and 56) in group 3, with eUUN ratio ≥25% (P = 0.048). The probability of a decrease in albuminuria with ARB treatment was lower in patients with an increase of eUUN or protein intake during the 16 wk of ARB treatment, as observed in multiple logistic regression analysis as well. The estimated urine urea excretion rate showed a positive association with the level of albuminuria in hypertensive patients with chronic kidney disease. The increase of eUUN excretion ameliorated the antiproteinuric effect of ARB

  12. Formation of Nitrogen Oxides in an Apokamp-Type Plasma Source

    Science.gov (United States)

    Sosnin, É. A.; Goltsova, P. A.; Panarin, V. A.; Skakun, V. S.; Tarasenko, V. F.; Didenko, M. V.

    2017-08-01

    Using optical and chemical processes, the composition of the products of decay of the atmospheric-pressure non-equilibrium plasma is determined in a pulsed, high-voltage discharge in the modes of apokampic and corona discharges. It is shown that the products of decay primarily contain nitrogen oxides NO x, and in the mode of the corona discharge - ozone. Potential applications of this source of plasma are discussed with respect to plasma processing of the seeds of agricultural crops.

  13. Síntese de proteína microbiana e concentrações de uréia em vacas alimentadas com dietas à base de palma forrageira e diferentes volumosos Microbial protein synthesis and urea nitrogen concentrations in lactating dairy cows fed spineless cactus and different forages based diets

    Directory of Open Access Journals (Sweden)

    Marcelo de Andrade Ferreira

    2009-01-01

    Full Text Available Cinco vacas da raça Holandesa foram distribuídas em um quadrado latino 5 × 5 com o objetivo de estimar a produção de proteína microbiana utilizando-se a excreção total de derivados de purinas (DP, por meio de coletas spot de urina, e as concentrações de nitrogênio (N-uréia no plasma, no leite e na urina. As cinco dietas foram formuladas com diversos volumosos (bagaço de cana-de-açúcar; feno de capim-tifton; feno de capim-elefante; silagem de sorgo; e uma mistura de silagem de sorgo + bagaço de cana associados à palma forrageira. As concentrações de uréia (10,98 mg/dL e N-uréia (5,11 mg/dL no leite não foram afetadas pelos volumosos, assim como as concentrações plasmáticas de uréia (28,10 mg/dL e N-uréia (13,09 mg/dL. As excreções urinárias de uréia, N-uréia, alantoína e derivados de purina, purinas absorvidas, a síntese de N-microbiano e as concentrações de alantoína no leite não foram alteradas. Os volumosos utilizados podem ser associados a palma forrageira na alimentação de vacas Holandesas, pois não alteram a produção de proteína microbiana.Five Holstein cows were allotted to a 5 × 5 Latin square design with the objective of evaluating the microbial protein production, using the total excretion of purine derivatives (PD, obtained from spot urine collection, plasma and milk urea and nitrogen (N-urea. The five treatments contained different forage sources: sugar cane bagasse (CB, tifton hay (TH, elephant grass hay (EH, sorghum silage (SS and a mixture of sugar cane bagasse + sorghum silage (CBSS. The milk urea (10.98 mg/dL and N-urea (5.11 mg/dL concentrations were not influenced by the forage sources, such as plasma urea (28.10 mg/dL and N-urea (13.09 mg/dL concentrations. The urinary urea, N-urea, allantoin and PD excretions, the absorbed purine, N-microbial synthesis and milk allantoin concentration remained unchanged. The different forage sources in association with forage cactus did not change

  14. Evaluation of between-cow variation in milk urea and rumen ammonia nitrogen concentrations and the association with nitrogen utilization and diet digestibility in lactating cows.

    Science.gov (United States)

    Huhtanen, P; Cabezas-Garcia, E H; Krizsan, S J; Shingfield, K J

    2015-05-01

    Concentrations of milk urea N (MUN) are influenced by dietary crude protein concentration and intake and could therefore be used as a biomarker of the efficiency of N utilization for milk production (milk N/N intake; MNE) in lactating cows. In the present investigation, data from milk-production trials (production data set; n=1,804 cow/period observations from 21 change-over studies) and metabolic studies involving measurements of nutrient flow at the omasum in lactating cows (flow data set; n=450 cow/period observations from 29 studies) were used to evaluate the influence of between-cow variation on the relationship of MUN with MNE, urinary N (UN) output, and diet digestibility. All measurements were made on cows fed diets based on grass silage supplemented with a range of protein supplements. Data were analyzed by mixed-model regression analysis with diet within experiment and period within experiment as random effects, allowing the effect of diet and period to be excluded. Between-cow coefficient of variation in MUN concentration and MNE was 0.13 and 0.07 in the production data set and 0.11 and 0.08 in the flow data set, respectively. Based on residual variance, the best model for predicting MNE developed from the production data set was MNE (g/kg)=238 + 7.0 × milk yield (MY; kg/d) - 0.064 × MY(2) - 2.7 × MUN (mg/dL) - 0.10 body weight (kg). For the flow data set, including both MUN and rumen ammonia N concentration with MY in the model accounted for more variation in MNE than when either term was used with MY alone. The best model for predicting UN excretion developed from the production data set (n=443) was UN (g/d)=-29 + 4.3 × dry matter intake (kg/d) + 4.3 × MUN + 0.14 × body weight. Between-cow variation had a smaller influence on the association of MUN with MNE and UN output than published estimates of these relationships based on treatment means, in which differences in MUN generally arise from variation in dietary crude protein concentration. For

  15. Comparison of the difference and delta 15nitrogen approaches for evaluating liquid urea ammonium nitrate utilization by maize

    International Nuclear Information System (INIS)

    Clay, D.E.

    1997-01-01

    Isotopic nitrogen (N) research techniques may be required in watershed studies to determine the impact of landscape position on fertilizer efficiency and the soil supplying power. However, traditional approaches using 15N labeled fertilizer may not be suitable when farmer equipment is used. The delta 15N natural abundance isotopic approach has been used to evaluate N cycling in watersheds. The objectives of this study were to measure the precision of the delta 15N measurement by the Europa 20-20 ratio mass spectrometer (Europa Scientific Ltd, UK), and to compare the difference and delta 15N approaches for measuring fertilizer use by maize (Zea mays). A replicated field study containing two different N rates (0 and 15.7 g N m-2) were used for the study. Maize samples were collected at the 8th-leaf, silking, and plant maturity in 1992 and 1993. Samples were dried (80 degrees C), ground (1-mm), weighed (stover 12 mg and grain 3 mg), and analyzed for total N and delta 15N. Fertilizer utilization at the three growth stages was determined using the natural abundance delta 15N and nonisotopic difference (fertilizer-control) techniques. During the study, the Europa 20-20 ratio mass spectrometer (Europa Scientific Ltd, UK) analyzed over 100 samples a day and had consumable costs of less than $2.00 per sample. The standard deviations of the mean were less than 0.11 and 0.21 per thousand in 51 and 77% of the stover samples, respectively. In 1992, grain yields were not influenced by N fertilizer additions, while in 1993 grain yields were increased by N fertilizer. The difference method estimated that in 1992, 16% of the N fertilizer was utilized by the crop, while the natural abundance delta 15N approach estimated that 36% of the fertilizer N was used by the crop. Differences between calculated values by the two techniques resulted from the difference method calculating net fertilizer use, while the delta 15N approach calculated fertilizer contained in the plant

  16. Non-equilibrium nitrogen DC-arc plasma treatment of TiO2 nanopowder.

    Science.gov (United States)

    Suzuki, Yoshikazu; Gonzalez-Aguilar, José; Traisnel, Noel; Berger, Marie-Hélène; Repoux, Monique; Fulcheri, Laurent

    2009-01-01

    Non-equilibrium nitrogen DC-arc plasma treatment of a commercial TiO2 anatase nanopowder was examined to obtain nitrogen-doped TiO2. By using a non-thermal discharge at low current (150 mA) and high voltage (1200 V) using pure N2 gas, light yellowish-gray TiO2 powder was successfully obtained within a short period of 5-10 min. XPS and TEM-EELS studies confirmed the existence of doped nitrogen. Due to the relatively mild conditions (plasma power of 180 W), metastable anatase structure and fine crystallite size of TiO2 (ca. 10 nm) were maintained after the plasma treatment. The in-flight powder treatment system used in this study is promising for various type of powder treatment.

  17. Radio-frequency plasma nitriding and nitrogen plasma immersion ion implantation of Ti-6Al-4V alloy

    International Nuclear Information System (INIS)

    Wang, S.Y.; Chu, P.K.; Tang, B.Y.; Zeng, X.C.; Wang, X.F.; Chen, Y.B.

    1997-01-01

    Nitrogen ion implantation improves the wear resistance of Ti-6Al-4V alloys by forming a hard TiN superficial passivation layer. However, the thickness of the layer formed by traditional ion implantation is typically 100-200 nm and may not be adequate for many industrial applications. We propose to use radio-frequency (RF) plasma nitriding and nitrogen plasma immersion ion implantation (PIII) to increase the layer thickness. By using a newly designed inductively coupled RF plasma source and applying a series of negative high voltage pulses to the Ti-6Al-4V samples. RF plasma nitriding and nitrogen PIII can be achieved. Our process yields a substantially thicker modified layer exhibiting more superior wear resistance characteristics, as demonstrated by data from micro-hardness testing, pin-on-disc wear testing, scanning electron microscopy (SEM), as well as Auger electron spectroscopy (AES). The performance of our newly developed inductively coupled RF plasma source which is responsible for the success of the experiments is also described. (orig.)

  18. Inductively coupled plasma--atomic emission spectroscopy: an evaluation of the use of nitrogen--argon admixtures as plasma discharge atmospheres

    International Nuclear Information System (INIS)

    Zalewski, J.C.

    1979-01-01

    The effects of the use of nitrogen in either the plasma coolant or aerosol carrier gas flows on the physical and spectrochemical properties of the inductively coupled plasma (ICP) were examined. While the plasma operated with nitrogen in the coolant flow exhibited a stability comparable to that of the argon plasma, the use of nitrogen in the aerosol carrier gas flow resulted in a plasma that was less stable. The detection limits obtained for the three plasmas exhibited a similar trend. In addition, the use of nitrogen--argon admixtures in the plasma coolant gas flow yielded an increase in both the net analyte and the background emission intensities when the corresponding argon and nitrogen--argon plasmas were operated under various conditions. Furthermore, the effect of aluminum on the Ca II (393.4 nm) spectral line was reported for the 1000/1 Al/Ca molar ratio. At an observation height of 15 mm, the signal depressions were 4 and 14% for the nitrogen--argon and the argon plasmas, respectively. The above experimental evidence suggested that the operation of the ICP with an Ar--N 2 coolant gas might be hotter than the argon plasma currently in use in this laboratory. The demountable plasma torch designed in collaboration with K. Olson yielded detection limits for 15 elements and 19 spectral lines that were approximately within a factor of two of those obtained with the torch of fused quartz design. The design also appeared to offer a more readily initiated plasma discharge. The experimental evidence presented supports the utilization of nitrogen--argon admixtures in the plasma coolant gas flow as alternate discharge atmospheres for inductively coupled plasma--atomic emission spectroscopy. In contrast, the experimental evidence shows that there is a deterioration in both physical and spectrochemical properties of plasmas operated with a nitrogen aerosol carrier gas

  19. Nitrogen plasma-treated multilayer graphene-based field effect transistor fabrication and electronic characteristics

    Science.gov (United States)

    Su, Wei-Jhih; Chang, Hsuan-Chen; Honda, Shin-ichi; Lin, Pao-Hung; Huang, Ying-Sheng; Lee, Kuei-Yi

    2017-08-01

    Chemical doping with hetero-atoms is an effective method used to change the characteristics of materials. Nitrogen doping technology plays a critical role in regulating the electronic properties of graphene. Nitrogen plasma treatment was used in this work to dope nitrogen atoms to modulate multilayer graphene electrical properties. The measured I-V multilayer graphene-base field-effect transistor characteristics (GFETs) showed a V-shaped transfer curve with the hole and electron region separated from the measured current-voltage (I-V) minimum. GFETs fabricated with multilayer graphene from chemical vapor deposition (CVD) exhibited p-type behavior because of oxygen adsorption. After using different nitrogen plasma treatment times, the minimum in I-V characteristic shifted into the negative gate voltage region with increased nitrogen concentration and the GFET channel became an n-type semiconductor. GFETs could be easily fabricated using this method with potential for various applications. The GFET transfer characteristics could be tuned precisely by adjusting the nitrogen plasma treatment time.

  20. Direct deposition of aluminum oxide gate dielectric on graphene channel using nitrogen plasma treatment

    International Nuclear Information System (INIS)

    Lim, Taekyung; Kim, Dongchool; Ju, Sanghyun

    2013-01-01

    Deposition of high-quality dielectric on a graphene channel is an essential technology to overcome structural constraints for the development of nano-electronic devices. In this study, we investigated a method for directly depositing aluminum oxide (Al 2 O 3 ) on a graphene channel through nitrogen plasma treatment. The deposited Al 2 O 3 thin film on graphene demonstrated excellent dielectric properties with negligible charge trapping and de-trapping in the gate insulator. A top-gate-structural graphene transistor was fabricated using Al 2 O 3 as the gate dielectric with nitrogen plasma treatment on graphene channel region, and exhibited p-type transistor characteristics

  1. Development of bio/blood compatible polypropylene through low pressure nitrogen plasma surface modification

    International Nuclear Information System (INIS)

    Gomathi, N.; Rajasekar, R.; Babu, R. Rajesh; Mishra, Debasish; Neogi, S.

    2012-01-01

    Surface modification of polypropylene by nitrogen containing plasma was performed in this work in order to improve the wettability which resulted in enhanced biocompatibility and blood compatibility. Various nitrogen containing functional groups as well as oxygen containing functional groups were found to be incorporated to the polymer surface during plasma treatment and post plasma reaction respectively. Wettability of the polymers was evaluated by static contact angle measurement to show the improvement in hydrophilicity of plasma treated polypropylene. Cross linking and surface modification were reported to be dominating in the case of nitrogen plasma treatment compared to degradation. The effect of various process variables namely power, pressure, flow rate and treatment time on surface energy and weight loss was studied at various levels according to the central composite design of response surface methodology (RSM). Except pressure the other variables resulted in increased weight loss due to etching whereas with increasing pressure weight loss was found to increase and then decrease. The effect of process variables on surface morphology of polymers was evaluated by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Well spread fibroblast cells on nitrogen plasma treated polypropylene due to the presence of CO, NH 2+ and NH + was observed. Reduced platelet adhesion and increased partial thromboplastin time evidenced the increased blood compatibility. - Highlights: ► Improved biocompatibility and blood compatibility of polypropylene. ► Nitrogen plasma surface modification. ► Maintaining a balance between polar group incorporation and weight loss due to etching. ► Optimization of process conditions by response surface methodology.

  2. Simultaneous removal of nitrogen oxide/nitrogen dioxide/sulfur dioxide from gas streams by combined plasma scrubbing technology.

    Science.gov (United States)

    Chang, Moo Been; Lee, How Ming; Wu, Feeling; Lai, Chi Ren

    2004-08-01

    Oxides of nitrogen (NOx) [nitrogen oxide (NO) + nitrogen dioxide (NO2)] and sulfur dioxide (SO2) are removed individually in traditional air pollution control technologies. This study proposes a combined plasma scrubbing (CPS) system for simultaneous removal of SO2 and NOx. CPS consists of a dielectric barrier discharge (DBD) and wet scrubbing in series. DBD is used to generate nonthermal plasmas for converting NO to NO2. The water-soluble NO2 then can be removed by wet scrubbing accompanied with SO2 removal. In this work, CPS was tested with simulated exhausts in the laboratory and with diesel-generator exhausts in the field. Experimental results indicate that DBD is very efficient in converting NO to NO2. More than 90% removal of NO, NOx, and SO2 can be simultaneously achieved with CPS. Both sodium sulfide (Na2S) and sodium sulfite (Na2SO3) scrubbing solutions are good for NO2 and SO2 absorption. Energy efficiencies for NOx and SO2 removal are 17 and 18 g/kWh, respectively. The technical feasibility of CPS for simultaneous removal of NO, NO2, and SO2 from gas streams is successfully demonstrated in this study. However, production of carbon monoxide as a side-product (approximately 100 ppm) is found and should be considered.

  3. Modulation of the gut microbiota with antibiotic treatment suppresses whole body urea production in neonatal pigs

    DEFF Research Database (Denmark)

    Puiman, Patrycja; Stoll, Barbara; Mølbak, Lars

    2013-01-01

    We examined whether changes in the gut microbiota induced by clinically relevant interventions would impact the bioavailability of dietary amino acids in neonates. We tested the hypothesis that modulation of the gut microbiota in neonatal pigs receiving no treatment (control), intravenously...... administered antibiotics, or probiotics affects whole body nitrogen and amino acid turnover. We quantified whole body urea kinetics, threonine fluxes, and threonine disposal into protein, oxidation, and tissue protein synthesis with stable isotope techniques. Compared with controls, antibiotics reduced...... the number and diversity of bacterial species in the distal small intestine (SI) and colon. Antibiotics decreased plasma urea concentrations via decreased urea synthesis. Antibiotics elevated threonine plasma concentrations and turnover, as well as whole body protein synthesis and proteolysis. Antibiotics...

  4. Transfer of blood urea into the goat colon

    International Nuclear Information System (INIS)

    Engelhardt, W. von; Hinderer, S.

    1976-01-01

    Transfer of blood urea to the temporarily isolated and perfused colon of conscious goats was measured. Simultaneously, total urea turnover was estimated using 14 C-labelled urea. Three animals in the weight range 50-70 k were used, with appropriately placed cannulae. The entry of blood urea into the total gastrointestinal tract was estimated from the difference between total urea turnover renal urea excretion. When experimental conditions remained constant, such as the permeability of the gastrointestinal tract wall, blood urea diffusion into the colon depended on plasma urea concentration. Results of varying feeding conditions demonstrated that changes in permeability of the gastrointestinal tract will have a more pronounced influence on the amounts of blood urea entering the gastrointestinal tract than differences in plasma urea concentration

  5. XUV radiation from gaseous nitrogen and argon target laser plasmas

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Vrbová, M.; Brůža, P.; Pánek, D.; Krejčí, F.; Kroupa, M.; Jakůbek, J.

    2012-01-01

    Roč. 370, č. 1 (2012), s. 012049 ISSN 1742-6588. [Latin American Workshop on Plasma Physics (LAWPP 2011)/14/. Mar del Plata, 20.11.2011-25.11.2011] R&D Projects: GA MŠk LA08024; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : Laser plasma source of XUV radiation in water window range * RHMD Z* engine code Subject RIV: BH - Optics, Masers, Lasers http://iopscience.iop.org/1742-6596/370/1/012049/pdf/1742-6596_370_1_012049.pdf

  6. DNA damage in oral cancer cells induced by nitrogen atmospheric pressure plasma jets

    Science.gov (United States)

    Han, Xu; Klas, Matej; Liu, Yueying; Stack, M. Sharon; Ptasinska, Sylwia

    2013-09-01

    The nitrogen atmospheric pressure plasma jet (APPJ) has been shown to effectively induce DNA double strand breaks in SCC-25 oral cancer cells. The APPJ source constructed in our laboratory consists of two external electrodes wrapping around a quartz tube and nitrogen as a feed gas and operates based on dielectric barrier gas discharge. Generally, it is more challenging to ignite plasma in N2 atmosphere than in noble gases. However, this design provides additional advantages such as lower costs compared to the noble gases for future clinical operation. Different parameters of the APPJ configuration were tested in order to determine radiation dosage. To explore the effects of delayed damage and cell self-repairing, various incubation times of cells after plasma treatment were also performed. Reactive species generated in plasma jet and in liquid environment are essential to be identified and quantified, with the aim of unfolding the mystery of detailed mechanisms for plasma-induced cell apoptosis. Moreover, from the comparison of plasma treatment effect on normal oral cells OKF6T, an insight to the selectivity for cancer treatment by APPJ can be explored. All of these studies are critical to better understand the damage responses of normal and abnormal cellular systems to plasma radiation, which are useful for the development of advanced plasma therapy for cancer treatment at a later stage.

  7. Radiation induced changes in plasma total protein nitrogen and urinary total nitrogen in desert rodent and albino rats subjected to dietary protein deficiency

    International Nuclear Information System (INIS)

    Roushdy, H.; El-Husseini, M.; Saleh, F.

    1986-01-01

    The effect of gamma-irradiation on plasma total protein nitrogen and urinary total nitrogen was studied in the desert rodent, psammomy obesus obesus and albino rats subjected to dietary protein deficiency. In albino rats kept on high protein diet, the radiation syndrome resulted in urine retention, while in those kept on non-protein diet, such phenomenon was recorded only with the high radiation level of 1170r. Radiation exposure to 780 and 1170r caused remarkable diuresis in psammomys obesus obesus whereas they induced significant urine retention in albino rats. The levels of plasma total protein nitrogen and urinary total nitrogen were higher in albino rats maintained on high protein diet than in those kept on non-protein diet. Radiation exposure caused an initial drop in plasma total protein nitrogen concentration, concomitant with an initial rise in total urinary nitrogen, radiation exposure of psammomys obesus obesus caused significant increase in the levels of plasma protein nitrogen and urinary total nitrogen. Psammomys obesus obesus seemed to be more affected by radiation exposure than did the albino rats

  8. Nitrogen fertilization efficiency with Urea (15N) in Brachiaria brizantha cv. Marandu associated with split application of ordinary superphosphate and potassium chloride

    International Nuclear Information System (INIS)

    Oliveira, P.P.A.; Trivelin, P.C.O.; Oliveira, W.S.

    2003-01-01

    In pastures, the evaluation of fertilization efficiency of urea-N is important since it is applied on a massive scale. Several studies report an enhancement of the fertilizers efficiency by associated applications of urea with potassium chloride (KCl) and ordinary superphosphate (OSP). In the recovery of degraded pastures or in intensive exploration systems, high quantities of KCl and OSP used as corrective fertilization are applied at the november, beginning of the rain season. Split applications of KCl and OSP could easily be associated with urea-N surface application without additional costs. An evaluation of this management was the objective of this experiment. The annual balance of 15 N application with urea was obtained in treatments where OSP and/or KCl were split, top-dressed in five applications associated with urea, or when both were applied together in November. Highest forage production was obtained when OSP was split, followed by split KCl, the unique application of both together, and finally both split. The recovery of urea-N in the aerial part and the soil-pasture system remained unaltered by the treatments. However, the recovery of plant crown and root system differed among the treatments and was positively correlated with forage production. Fertilizer-N recovery in the litter was favored by splitting KCl. Even though the total recovery of the system was not improved by the treatments, splitting of KCl and OSP are indicated for an increased recovery of urea-N in numerous plant structures, resulting in a higher forage production. (author)

  9. DNA damage in oral cancer cells induced by nitrogen atmospheric pressure plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xu; Ptasinska, Sylwia [Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Klas, Matej [Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Liu, Yueying [Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Sharon Stack, M. [Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2013-06-10

    The nitrogen atmospheric pressure plasma jet (APPJ) was applied to induce DNA damage of SCC-25 oral cancer cells. Optical emission spectra were taken to characterize the reactive species produced in APPJ. In order to explore the spatial distribution of plasma effects, cells were placed onto photo-etched grid slides and the antibody H2A.X was used to locate double strand breaks of DNA inside nuclei using an immunofluorescence assay. The number of cells with double strand breaks in DNA was observed to be varied due to the distance from the irradiation center and duration of plasma treatment.

  10. DNA damage in oral cancer cells induced by nitrogen atmospheric pressure plasma jets

    International Nuclear Information System (INIS)

    Han, Xu; Ptasinska, Sylwia; Klas, Matej; Liu, Yueying; Sharon Stack, M.

    2013-01-01

    The nitrogen atmospheric pressure plasma jet (APPJ) was applied to induce DNA damage of SCC-25 oral cancer cells. Optical emission spectra were taken to characterize the reactive species produced in APPJ. In order to explore the spatial distribution of plasma effects, cells were placed onto photo-etched grid slides and the antibody H2A.X was used to locate double strand breaks of DNA inside nuclei using an immunofluorescence assay. The number of cells with double strand breaks in DNA was observed to be varied due to the distance from the irradiation center and duration of plasma treatment.

  11. Numerical simulation of a novel non-transferred arc plasma torch operating with nitrogen

    International Nuclear Information System (INIS)

    Hiremath, Gavisiddayya; Kandasamy, Ramachandran; Ganesh, Ravi

    2015-01-01

    High power plasma torches with higher electro-thermal efficiency are required for industrial applications. To increase the plasma power and electrothermal efficiency, conventional torches are being modified to operate with molecular gases such as air and nitrogen. Since increasing arc current enhances the heat loss to the anode, torches are being developed to operate under high voltage and low current. The plasma flow dynamics and electromagnetic coupling with plasma flow inside the torch etc. are highly complex and knowledge on the same is required to develop high torches with higher efficiency. Unfortunately detailed experimentation on the same is very difficult. Numerical modeling and simulation is one of the best tools to understand the physics involved in such complex processes. A 2D numerical model is developed to simulate the characteristics of the plasma inside the torch. Though plasma is not in local thermodynamic equilibrium (LTE) close to the electrodes, LTE is assumed everywhere in the plasma to avoid complex and time consuming calculations. Other valid assumptions used in the model are plasma flow is optically thin, laminar and incompressible. Flow, energy and electromagnetic equations are solved with appropriate boundary conditions and volume sources using SIMPLE algorithm with finite volume method. Temperature dependent thermophysical properties of nitrogen are used for the simulations. Simulations are carried out for different experimental conditions. The effects of arc current, gas flow rate of plasma generating gas and sheath gas injected above the bottom anode on the arc voltage, electrothermal efficiency of the torch, plasma temperature and plasma velocity are simulated. Predicted results are compared with experimental results. (author)

  12. Stable isotope sup 15 N-urea and clinical research in nephrology

    Energy Technology Data Exchange (ETDEWEB)

    Sugino, Nobuhiro; Arai, Junko; Akimoto, Mitsuko; Miwa, Toichiro; Takuma, Takehide (Tokyo Women' s Medical Coll. (Japan))

    1990-08-01

    Stable isotope {sup 15}N-compound, {sup 15}N-urea, is useful marker to investigate nitrogen metabolism in clinical nephrology, particularly in chronic renal failure or dialysis. {sup 15}N-urea incorporation into plasma albumin in addition to plasma {sup 15}N disappearance was studied in 6 patients with endstage chronic renal failure. As a result, only minor fraction of administered {sup 15}N-urea was incorporated into albumin in this study. In addition, it was also confirmed that high energy diet may promote protein synthesis through {sup 15}N incorporation to plasma amino acids, such as alanine, in these patients with low protein meal. Therefore, administration of {sup 15}N-compound to human subjects may contribute to provide us the important informations on nitrogen metabolism. For instance, urea kinetics are described in the endstage chronic renal failure in this review. However, less expensive {sup 15}N-compounds should be provided and more simple but accurate measurement of {sup 15}N activity should be developed for the further clinical application of the stable isotope. (author).

  13. Stable isotope 15N-urea and clinical research in nephrology

    International Nuclear Information System (INIS)

    Sugino, Nobuhiro; Arai, Junko; Akimoto, Mitsuko; Miwa, Toichiro; Takuma, Takehide

    1990-01-01

    Stable isotope 15 N-compound, 15 N-urea, is useful marker to investigate nitrogen metabolism in clinical nephrology, particularly in chronic renal failure or dialysis. 15 N-urea incorporation into plasma albumin in addition to plasma 15 N disappearance was studied in 6 patients with endstage chronic renal failure. As a result, only minor fraction of administered 15 N-urea was incorporated into albumin in this study. In addition, it was also confirmed that high energy diet may promote protein synthesis through 15 N incorporation to plasma amino acids, such as alanine, in these patients with low protein meal. Therefore, administration of 15 N-compound to human subjects may contribute to provide us the important informations on nitrogen metabolism. For instance, urea kinetics are described in the endstage chronic renal failure in this review. However, less expensive 15 N-compounds should be provided and more simple but accurate measurement of 15 N activity should be developed for the further clinical application of the stable isotope. (author)

  14. Variation of milk urea in dairy cattle : a study on factors that affect the relationship between urea concentration in milk and urea excretion in urine

    NARCIS (Netherlands)

    Spek, J.W.

    2013-01-01

    The aim of this thesis was to increase the applicability of milk urea nitrogen concentration (MUN) as a predictor of urinary urea nitrogen excretion (UUN) by identifying and quantifying factors that can explain variation in MUN that is not related to UUN. A literature study was conducted in

  15. Substituição total do farelo de soja por uréia ou amiréia, em dietas com alto teor de concentrado, sobre a amônia ruminal, os parâmetros sangüíneos e o metabolismo do nitrogênio em bovinos de corte Total replacement of soybean meal by urea or starea in high grain diets on nitrogen metabolism, ruminal ammonia-N concentration and blood parameters in beef cattle

    Directory of Open Access Journals (Sweden)

    Reinaldo Cunha de Oliveira Junior

    2004-06-01

    Full Text Available Seis novilhos da raça Nelore, não castrados, com peso médio inicial de 420 kg, distribuídos em delineamento em quadrado latino 3x3 duplicado, foram utilizados para avaliar a substituição total de uma fonte de proteína verdadeira (farelo de soja, em uma dieta deficiente em proteína degradável no rúmen (PDR, por uréia ou amiréia (fontes de nitrogênio não protéico, ambas em uma dieta adequada em PDR. As dietas foram isoprotéicas (13,0% utilizando-se o bagaço de cana-de-açúcar in natura (BIN como única fonte de volumoso (20% da MS. Foram avaliados: a concentração de amônia ruminal, nitrogênio uréico plasmático, glicose plasmática e o metabolismo do nitrogênio. Os tratamentos foram: 1 farelo de soja (FS; 2 uréia e 3 amiréia (A-150S. A concentração de nitrogênio amoniacal no fluido ruminal foi superior no tratamento com uréia, comparado ao tratamento com farelo de soja, sendo que o tratamento com amiréia não diferiu dos demais. O tratamento com amiréia apresentou maior perda de N urinário. A retenção de N (g/d e % do consumido e o valor biológico da proteína (N retido, % do N digerido foram superiores para o tratamento com uréia, comparado aos demais. A concentração de nitrogênio uréico no plasma e a concentração de glicose plasmática foram similares entre os tratamentos. A substituição total do farelo de soja por uréia, ajustando a PDR na dieta de bovinos de corte, demonstrou ser viável. A uréia na forma convencional apresentou vantagens em relação à amiréia.Six Nellore bulls, with initial body weight of 420 kg, were assigned to a duplicated 3x3 Latin square design to evaluate the effects of replacing a true protein source (soybean meal, of high biological value, in a rumen degradable protein (RDP deficient diet, by urea or starea (a supposedly slow release nonprotein nitrogen source, both in a RDP adjusted diet. In natura sugarcane bagasse as the only source of forage (20% of DM. Evaluated

  16. Interaction between dietary content of protein and sodium chloride on milk urea concentration, urinary urea excretion, renal recycling of urea, and urea transfer to the gastrointestinal tract in dairy cows.

    Science.gov (United States)

    Spek, J W; Bannink, A; Gort, G; Hendriks, W H; Dijkstra, J

    2013-09-01

    Dietary protein and salt affect the concentration of milk urea nitrogen (MUN; mg of N/dL) and the relationship between MUN and excretion of urea nitrogen in urine (UUN; g of N/d) of dairy cattle. The aim of the present study was to examine the effects of dietary protein and sodium chloride (NaCl) intake separately, and their interaction, on MUN and UUN, on the relationship between UUN and MUN, on renal recycling of urea, and on urea transfer to the gastrointestinal tract. Twelve second-parity cows (body weight of 645±37 kg, 146±29 d in milk, and a milk production of 34.0±3.28 kg/d), of which 8 were previously fitted with a rumen cannula, were fitted with catheters in the urine bladder and jugular vein. The experiment had a split-plot arrangement with dietary crude protein (CP) content as the main plot factor [116 and 154 g of CP/kg of dry matter (DM)] and dietary NaCl content as the subplot factor (3.1 and 13.5 g of Na/kg of DM). Cows were fed at 95% of the average ad libitum feed intake of cows receiving the low protein diets. Average MUN and UUN were, respectively, 3.90 mg of N/dL and 45 g of N/d higher for the high protein diets compared with the low protein diets. Compared with the low NaCl diets, MUN was, on average, 1.74 mg of N/dL lower for the high NaCl diets, whereas UUN was unaffected. We found no interaction between dietary content of protein and NaCl on performance characteristics or on MUN, UUN, urine production, and renal clearance characteristics. The creatinine clearance rate was not affected by dietary content of protein and NaCl. Urea transfer to the gastrointestinal tract, expressed as a fraction of plasma urea entry rate, was negatively related to dietary protein, whereas it was not affected by dietary NaCl content. We found no interaction between dietary protein and NaCl content on plasma urea entry rate and gastrointestinal urea entry rate or their ratio. The relationship between MUN and UUN was significantly affected by the class variable

  17. Foliar absorption of 15N labeled urea by tea plant

    International Nuclear Information System (INIS)

    Hoshina, Tsuguo; Kozai, Shuji; Ishigaki, Kozo

    1978-01-01

    The effect of foliar application on the nitrogen nutrient status of tea shoots has been studied using 15 N labelled urea. Furthermore, the difference in nitrogen utilization by tea plant between foliar applied and top dressed nitrogen was investigated using 15 N labelled urea and ammonium sulfate. The foliar application of urea increased the amount of chlorophyll and total nitrogen in the new shoot, and the foliar application was more effective under shading condition. The urea sprayed upon old leaves prior to the opening of new leaf translocated to the new shoots. However, the foliar application after the opening of new leaf was more effective on nitrogen absorption by new shoots than one prior to that, and rather than top dressing for new shoots. It could be recognized that the foliar application of urea raises the nitrogen nutrient status of tea leaves in summer. (author)

  18. Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling.

    Science.gov (United States)

    Wang, Weizong; Patil, Bhaskar; Heijkers, Stjin; Hessel, Volker; Bogaerts, Annemie

    2017-05-22

    The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO 2 yields and the corresponding energy efficiency for NO x formation for different N 2 /O 2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NO x . The results indicate that vibrational excitation of N 2 in the gliding arc contributes significantly to activating the N 2 molecules, and leads to an energy efficient way of NO x production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NO x formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale Haber-Bosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which low-temperature plasma technology might play an important role. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Nitrogen

    Science.gov (United States)

    Apodaca, Lori E.

    2013-01-01

    The article presents an overview of the nitrogen chemical market as of July 2013, including the production of ammonia compounds. Industrial uses for ammonia include fertilizers, explosives, and plastics. Other topics include industrial capacity of U.S. ammonia producers CF Industries Holdings Inc., Koch Nitrogen Co., PCS Nitrogen, Inc., and Agrium Inc., the impact of natural gas prices on the nitrogen industry, and demand for corn crops for ethanol production.

  20. Modeling nitrogen plasmas produced by intense electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Angus, J. R.; Swanekamp, S. B.; Schumer, J. W.; Hinshelwood, D. D. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Mosher, D.; Ottinger, P. F. [Independent contractors for NRL through Engility, Inc., Alexandria, Virginia 22314 (United States)

    2016-05-15

    A new gas–chemistry model is presented to treat the breakdown of a nitrogen gas with pressures on the order of 1 Torr from intense electron beams with current densities on the order of 10 kA/cm{sup 2} and pulse durations on the order of 100 ns. For these parameter regimes, the gas transitions from a weakly ionized molecular state to a strongly ionized atomic state on the time scale of the beam pulse. The model is coupled to a 0D–circuit model using the rigid–beam approximation that can be driven by specifying the time and spatial profiles of the beam pulse. Simulation results are in good agreement with experimental measurements of the line–integrated electron density from experiments done using the Gamble II generator at the Naval Research Laboratory. It is found that the species are mostly in the ground and metastable states during the atomic phase, but that ionization proceeds predominantly through thermal ionization of optically allowed states with excitation energies close to the ionization limit.

  1. Mechanism for heating of nitrogen plasmas in an electrodeless rf capacitive discharge at medium pressures

    International Nuclear Information System (INIS)

    Berdichevskii, M.G.; Marusin, V.V.

    1979-01-01

    The possible contributions of several processes to the experimentally observed heating of nitrogen plasmas in an electarodeless rf capacitive discharge at pressures of p=2.7-67 kPa are discussed. These processes are electron-rotational, vibrational--translational (V--T), and nonresonance vibrational--vibrational (V--V) energy exchange and effects due to O 2 , H 2 O, and NO impurities in the gas. It is shown that as the pressure is decreased the heating mechanism changes from quasiequilibrium to nonequilibrium V--T heating caused by overpopulation of high vibrational levels in the ground state of the nitrogen molecule

  2. Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

    2015-12-31

    Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

  3. Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

    International Nuclear Information System (INIS)

    Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu

    2015-01-01

    Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

  4. An update on the use of benzoate, phenylacetate and phenylbutyrate ammonia scavengers for interrogating and modifying liver nitrogen metabolism and its implications in urea cycle disorders and liver disease.

    Science.gov (United States)

    De Las Heras, Javier; Aldámiz-Echevarría, Luis; Martínez-Chantar, María-Luz; Delgado, Teresa C

    2017-04-01

    Ammonia-scavenging drugs, benzoate and phenylacetate (PA)/phenylbutyrate (PB), modulate hepatic nitrogen metabolism mainly by providing alternative pathways for nitrogen disposal. Areas covered: We review the major findings and potential novel applications of ammonia-scavenging drugs, focusing on urea cycle disorders and liver disease. Expert opinion: For over 40 years, ammonia-scavenging drugs have been used in the treatment of urea cycle disorders. Recently, the use of these compounds has been advocated in acute liver failure and cirrhosis for reducing hyperammonemic-induced hepatic encephalopathy. The efficacy and mechanisms underlying the antitumor effects of these ammonia-scavenging drugs in liver cancer are more controversial and are discussed in the review. Overall, as ammonia-scavenging drugs are usually safe and well tolerated among cancer patients, further studies should be instigated to explore the role of these drugs in liver cancer. Considering the relevance of glutamine metabolism to the progression and resolution of liver disease, we propose that ammonia-scavenging drugs might also be used to non-invasively probe liver glutamine metabolism in vivo. Finally, novel derivatives of classical ammonia-scavenging drugs with fewer and less severe adverse effects are currently being developed and used in clinical trials for the treatment of acute liver failure and cirrhosis.

  5. Study on the surface of fluorosilicone acrylate RGP contact lens treated by low-temperature nitrogen plasma

    International Nuclear Information System (INIS)

    Ren Li; Yin Shiheng; Zhao Lianna; Wang Yingjun; Chen Hao; Qu Jia

    2008-01-01

    In order to improve the surface hydrophilicity of fluorosilicone acrylate rigid gas permeable (RGP) contact lens, low temperature nitrogen plasma was used to modify the lens surface. Effects of plasma conditions on the surface structures and properties were investigated. Results indicated that the surface hydrophilicity of RGP contact lens was significantly improved after treatment. X-ray photoelectron spectroscopy (XPS) results showed that the nitrogen element was successfully incorporated into the surface. Furthermore, some new bonds such as N-C=O, F - and silicate were formed on the lens surface after nitrogen plasma treatment, which could result in the improvement of the surface hydrophilicity. Scanning electronic microscope (SEM) results indicated that nitrogen plasma with moderate power could make the surface smoother in some degree, while plasma with higher power could etch the surface

  6. Fabrication of spherical high-nitrogen stainless steel powder alloys by mechanical alloying and thermal plasma spheroidization

    Science.gov (United States)

    Razumov, Nikolay G.; Wang, Qing Sheng; Popovich, Anatoly A.; Shamshurin, Aleksey I.

    2018-04-01

    This paper describes the results of experimental studies on the treatment of Fe-23Cr-11Mn-1N high-nitrogen stainless steel powder alloys, synthesized by the mechanical alloying (MA) of elemental powders in the flow of a radio frequency thermal plasma. The as-milled powder with irregular particles were successfully converted into spherical high-nitrogen stainless steel powder alloy. Measurement of the residual nitrogen content in the obtained powder, shown that during the plasma spheroidization process, part of the nitrogen escapes from the alloy.

  7. Substitution of lucerne hay by untreated, urea-enriched and urea ...

    African Journals Online (AJOL)

    Wheat straw was left untreated (WS), enriched with 1.5% urea (UWS), or ammoniated with 5.5% urea in a stack for 8 .... nitrogen concentration for maximal microbial synthesis is in ... faeces and urine samples were taken daily and pooled for.

  8. Studies on the nitrogen metabolism of the large intestine of ruminants. 4

    International Nuclear Information System (INIS)

    Bergner, H.; Kijora, C.; Simon, O.; Goersch, R.

    1986-01-01

    Two experiments were performed with wethers (body weight 34 to 44 kg) receiving a ration rich in crude fiber at maintenance level. The animals were fitted with ileo-cecal cannulas into which 14 C-, 15 N-labelled urea together with digesta was introduced hourly for a 24 hours period (V 1 ; 2 animals). In experiment two (V 2 ; 3 animals) in addition HCl-partly hydrolyzed straw meal was introduced. After ureolytic degradation the intracecal applied urea entered mainly the intermediary metabolism. The resulting ammonia was resynthesized to urea without any time lag. The rate constant for the increase in 15 N labelling of urea was 3.2 d -1 in both experiments. Urea leaves the plasma with half-lives of 10.6 (V 1 ) and 5.2 (V 2 ) hours. More than 60% of the applied urea were excreted with urine. Formed 14 CO 2 appeared at proportions of 66% (V 2 ) and 71% (V 1 ) in the respiration gases. Both, the decline of the 14 C activity in blood plasma and the specific 14 C activity of CO 2 in the respiration gases after the end of the labelling period do not follow a kinetic of first order. The 15 N labelling of the NH 3 nitrogen in ileal digesta was very high and reached plateau values similar with those of plasma urea (2.54 vs. 2.56 atom-% 15 N excess). A direct entry of plasma urea into the small intestine was concluded. (author)

  9. Interaction between dietary content of protein and sodium chloride on milk urea concentration, urinary urea excretion, renal recycling of urea, and urea transfer to the gastrointestinal tract in dairy cows

    NARCIS (Netherlands)

    Spek, J.W.; Bannink, A.; Gort, G.; Hendriks, W.H.; Dijkstra, J.

    2013-01-01

    Dietary protein and salt affect the concentration of milk urea nitrogen (MUN; mg of N/dL) and the relationship between MUN and excretion of urea nitrogen in urine (UUN; g of N/d) of dairy cattle. The aim of the present study was to examine the effects of dietary protein and sodium chloride (NaCl)

  10. Atomic force microscopy of surface topography of nitrogen plasma treated steel

    CERN Document Server

    Mahboubi, F

    2002-01-01

    Nitriding of steels, using plasma environments has been practiced for many years. A lot of efforts have been put on developing new methods, such as plasma immersion ion implantation (Pl sup 3) and radio frequency (RF) plasma nitriding, for mass transfer of nitrogen into the surface of the work piece. This article presents the results obtained from an in depth investigation of the surface morphology of the treated samples, carried out using an atomic force microscope. Samples from a microalloyed steel, were treated by both methods for 5 hours at different temperatures ranging from 350 to 550 sup d eg sup C in 75% N sub 2 -25% H sub 2 atmosphere. It has been found that the surface of the samples treated by PI sup 3 technique, although having more favorable properties, were rougher than the surfaces treated by RF plasma nitriding.

  11. Microbial protein synthesis and concentration of urea in dairy heifers fed diets with cactus forage Opuntia

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Mercês Aguiar

    2015-04-01

    Full Text Available The objective was to analyze the influence of increasing levels of forage cactus Opuntia in the diet on the nitrogen balance, the concentrations of urea in urine and plasma and microbial protein synthesis in dairy heifers ¾ Holstein-zebu confined. twenty four heifers were used with initial body weight of 163.00 ± 18 kg, with 8 months old and distributed in a completely randomized design with four treatments and six replications. It was used sorghum silage, concentrate and increasing levels of forage cactus Opuntia in the diet (0, 200, 400 and 600 g kg-1. The nitrogen intake, feces and urine, digested and retained with the addition of forage cactus in the diet showed decreasing linear effect. Nitrogen balance was influenced by the inclusion of forage cactus in the diet of dairy heifers through the values observed for the digested and retained nitrogen, which can be related to similar effects found for the consumption of nitrogen and the nitrogen excretion in feces and urine. Nitrogen digested percentage of intake and nitrogen retention as a percentage of ingested and digested showed no difference with the inclusion of forage cactus in the diet. The concentration of urea nitrogen in the urine of heifers had a quadratic effect point of maximum excretion level of 275.80 g kg-1 of forage cactus in the diet. Consequently, the excretion of urea nitrogen and urea excretion showed similar effect with maximum points excretion levels of 293.75 and 319.00 g kg-1 of forage in the diet. The concentration of ureic nitrogen in plasma showed no difference, with an average value of 13.19 mg dL-1. Synthesis of nitrogen and microbial crude protein adjusted to the quadratic model. The microbial efficiency was not influenced by the inclusion of forage cactus in replacement of sorghum silage and concentrate. The urine volume similar to the treatments, with an average of 5.90 liters of urine per day, proving that the creatinine excretion in urine was not influenced

  12. Contrasting features of urea cycle disorders in human patients and knockout mouse models.

    Science.gov (United States)

    Deignan, Joshua L; Cederbaum, Stephen D; Grody, Wayne W

    2008-01-01

    The urea cycle exists for the removal of excess nitrogen from the body. Six separate enzymes comprise the urea cycle, and a deficiency in any one of them causes a urea cycle disorder (UCD) in humans. Arginase is the only urea cycle enzyme with an alternate isoform, though no known human disorder currently exists due to a deficiency in the second isoform. While all of the UCDs usually present with hyperammonemia in the first few days to months of life, most disorders are distinguished by a characteristic profile of plasma amino acid alterations that can be utilized for diagnosis. While enzyme assay is possible, an analysis of the underlying mutation is preferable for an accurate diagnosis. Mouse models for each of the urea cycle disorders exist (with the exception of NAGS deficiency), and for almost all of them, their clinical and biochemical phenotypes rather closely resemble the phenotypes seen in human patients. Consequently, all of the current mouse models are highly useful for future research into novel pharmacological and dietary treatments and gene therapy protocols for the management of urea cycle disorders.

  13. Plasma Wind Tunnel Investigation of European Ablators in Nitrogen/Methane Using Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ricarda Wernitz

    2013-01-01

    Full Text Available For atmospheric reentries at high enthalpies ablative heat shield materials are used, such as those for probes entering the atmosphere of Saturn’s moon Titan, such as Cassini-Huygens in December, 2004. The characterization of such materials in a nitrogen/methane atmosphere is of interest. A European ablative material, AQ60, has been investigated in plasma wind tunnel tests at the IRS plasma wind tunnel PWK1 using the magnetoplasma dynamic generator RD5 as plasma source in a nitrogen/methane atmosphere. The dimensions of the samples are 45 mm in length with a diameter of 39 mm. The actual ablator has a thickness of 40 mm. The ablator is mounted on an aluminium substructure. The experiments were conducted at two different heat flux regimes, 1.4 MW/m2 and 0.3 MW/m2. In this paper, results of emission spectroscopy at these plasma conditions in terms of plasma species’ temperatures will be presented, including the investigation of the free-stream species, N2 and N2+, and the major erosion product C2, at a wavelength range around 500 nm–600 nm.

  14. DNA damage in oral cancer and normal cells induced by nitrogen atmospheric pressure plasma jets

    Science.gov (United States)

    Han, Xu; Kapaldo, James; Liu, Yueying; Stack, M. Sharon; Ptasinska, Sylwia

    2015-09-01

    Nitrogen atmospheric pressure plasma jets (APPJs) have been shown to effectively induce DNA double strand breaks in SCC25 oral cancer cells. The APPJ source constructed in our laboratory operates based on dielectric barrier discharge. It consists of two copper electrodes alternatively wrapping around a fused silica tube with nitrogen as a feed gas. It is generally more challenging to ignite plasma in N2 atmosphere than in noble gases. However, N2 provides additional advantages such as lower costs compared to noble gases, thus this design can be beneficial for the future long-term clinical use. To compare the effects of plasma on cancer cells (SCC25) and normal cells (OKF), the cells from both types were treated at the same experimental condition for various treatment times. The effective area with different damage levels after the treatment was visualized as 3D maps. The delayed damage effects were also explored by varying the incubation times after the treatment. All of these studies are critical for a better understanding of the damage responses of cellular systems exposed to the plasma radiation, thus are useful for the development of the advanced plasma cancer therapy. The research described herein was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Basic Energy Sciences, Office of Science, United States Department of Energy through Grant No. DE-FC02-04ER15533.

  15. Plasma-assisted nitrogen doping of VACNTs for efficiently enhancing the supercapacitor performance

    Energy Technology Data Exchange (ETDEWEB)

    Mashayekhi, Alireza; Hosseini, Seyed Mahmoud [University of Tehran, Nano-fabricated Energy Devices Laboratory, School of Electrical and Computer Engineering, College of Engineering (Iran, Islamic Republic of); Hassanpour Amiri, Morteza; Namdar, Naser [University of Tehran, Thin Film and Nano-electronics Laboratory, Nano-electronics Centre of Excellence, School of Electrical and Computer Engineering, College of Engineering (Iran, Islamic Republic of); Sanaee, Zeinab, E-mail: z.sanaee@ut.ac.ir [University of Tehran, Nano-fabricated Energy Devices Laboratory, School of Electrical and Computer Engineering, College of Engineering (Iran, Islamic Republic of)

    2016-06-15

    Nitrogen doping of vertically aligned carbon nanotubes (VACNTs) using plasma-enhanced chemical vapour deposition has been investigated to improve the supercapacitance performance of CNTs. Incorporating electrochemical measurements on the open-ended nitrogen-doped CNTs, showed the achievement of 6 times improvement in the capacitance value. For nitrogen-doped CNTs on silicon substrate, specific capacitance of 60 F g{sup −1} was obtained in 0.5 M KCl solution, with capacity retention ratio above 90 % after cycled at 0.1 A g{sup −1} for 5000 cycles. Using this sample, a symmetric supercapacitance was fabricated which showed the power density of 37.5 kW kg{sup −1}. The facile fabrication approach and its excellent capacitance improvement, propose it as an efficient technique for enhancing the supercapacitance performance of the carbon-based electrodes.

  16. Amorphous carbon nitrogenated films prepared by plasma immersion ion implantation and deposition

    International Nuclear Information System (INIS)

    Rangel, Elidiane C.; Durrant, Steven F.; Rangel, Rita C.C.; Kayama, Milton E.; Landers, Richard; Cruz, Nilson C. da

    2006-01-01

    In this work, an investigation was conducted on amorphous hydrogenated-nitrogenated carbon films prepared by plasma immersion ion implantation and deposition. Glow discharge was excited by radiofrequency power (13.56 MHz, 40 W) whereas the substrate-holder was biased with 25 kV negative pulses. The films were deposited from benzene, nitrogen and argon mixtures. The proportion of nitrogen in the chamber feed (R N ) was varied against that of argon, while keeping the total pressure constant (1.3 Pa). From infrared reflectance-absorbance spectroscopy it was observed that the molecular structure of the benzene is not preserved in the film. Nitrogen was incorporated from the plasma while oxygen arose as a contaminant. X-ray photoelectron spectroscopy revealed that N/C and O/C atomic ratios change slightly with R N . Water wettability decreased as the proportion of N in the gas phase increased while surface roughness underwent just small changes. Nanoindentation measurements showed that film deposition by means of ion bombardment was beneficial to the mechanical properties of the film-substrate interface. The intensity of the modifications correlates well with the degree of ion bombardment

  17. Effect of 15 N-urea rates on the rates on the accumulation of nitrogen by the sugarcane-plant in cane field renovation areas picked with and without burning

    International Nuclear Information System (INIS)

    Vitti, Andre Cesar.; Ocheuze Trivelin, Paulo Cesar; Wagner de Oliveira, Mauro; De Castro Gava, Glauber Jose; Sarries, Gabriel Adrian

    1999-01-01

    The main goal of this work was the evaluation of the nitrogen accumulated in the sugarcane (Saccharum spp.), the contribution and the recovery of the fertilizer by the culture, both calculated by the isotopic technique . The experiment was conducted in 220-liter vase and in a open atmosphere. A randomized block design was performed with 2x4-factorial treatment arrangements with three replications. The factors were: 1) differentiated addition of two amounts of cultural wastes to the soil, equivalent to 13.2 and 19.5 t ha -1 of dry material, simulating cane-field renovation conditions in areas picked with or without burning (CQ and SQ); 2) four N-urea rates (10.082% in 15 N-atoms), equivalent to 0; 30; 60; 90 kg ha -1 . The analysis of variance of the results showed that there were no significant differences between CQ and SQ treatments. Out of the total accumulated N in the plant, an average of 20.55% was stored in the stalks; 19% in the apexes; 27% in the root system, and 33% in dry leaves. Therefore, around 80% of the nitrogen would remain in the area after the harvest without burning, which represents 40% more in relationship with the areas with burning. The accumulation of N in the root system was 70% higher in the larger rate in relation to the zero rate, being this amount a potential N source for the following cycle. Out of the total accumulated nitrogen 7 and 16% originated from the fertilizer, in function of the N-urea rates, with the use efficiency by the culture equivalent to 54%, regardless of the treatment

  18. Space-resolved characterization of high frequency atmospheric-pressure plasma in nitrogen, applying optical emission spectroscopy and numerical simulation

    International Nuclear Information System (INIS)

    Rajasekaran, Priyadarshini; Ruhrmann, Cornelia; Bibinov, Nikita; Awakowicz, Peter

    2011-01-01

    Averaged plasma parameters such as electron distribution function and electron density are determined by characterization of high frequency (2.4 GHz) nitrogen plasma using both experimental methods, namely optical emission spectroscopy (OES) and microphotography, and numerical simulation. Both direct and step-wise electron-impact excitation of nitrogen emissions are considered. The determination of space-resolved electron distribution function, electron density, rate constant for electron-impact dissociation of nitrogen molecule and the production of nitrogen atoms, applying the same methods, is discussed. Spatial distribution of intensities of neutral nitrogen molecule and nitrogen molecular ion from the microplasma is imaged by a CCD camera. The CCD images are calibrated using the corresponding emissions measured by absolutely calibrated OES, and are then subjected to inverse Abel transformation to determine space-resolved intensities and other parameters. The space-resolved parameters are compared, respectively, with the averaged parameters, and an agreement between them is established. (paper)

  19. Reduction of nitrogen oxides from simulated exhaust gas by using plasma-catalytic process

    International Nuclear Information System (INIS)

    Mok, Young Sun; Koh, Dong Jun; Shin, Dong Nam; Kim, Kyong Tae

    2004-01-01

    Removal of nitrogen oxides (NO x ) using a nonthermal plasma reactor (dielectric-packed bed reactor) combined with monolith V 2 O 5 /TiO 2 catalyst was investigated. The effect of initial NO x concentration, feed gas flow rate (space velocity), humidity, and reaction temperature on the removal of NO x was examined. The plasma reactor used can be energized by either ac or pulse voltage. An attempt was made to utilize the electrical ignition system of an internal combustion engine as a high-voltage pulse generator for the plasma reactor. When the plasma reactor was energized by the electrical ignition system, NO was readily oxidized to NO 2 . Performance was as good as with ac energization. Increasing the fraction of NO 2 in NO x , which is the main role of the plasma reactor, largely enhanced the NO x removal efficiency. In the plasma-catalytic reactor, the increases in initial NO x concentration, space velocity (feed gas flow rate) and humidity lowered the NO x removal efficiency. However, the reaction temperature in the range up to 473 K did not significantly affect the NO x removal efficiency in the presence of plasma discharge

  20. Entry of blood urea into the rumen of the llama

    International Nuclear Information System (INIS)

    Hinderer, S.; Engelhardt, W. von

    1976-01-01

    Transfer of body urea into the temporarily isolated rumen cleaned and filled with a test solution was measured in the llama. Simultaneously urea recirculation into the total gastro-intestinal tract (GI-tract) was estimated using 14 C-urea. The permeability of the rumen wall to urea could be changed significantly. With CO 2 or butyric acid in the test solution, permeability was highest, it was low when food was withheld and when no volatile fatty acids were present in the solution. Changes in the permeability can affect the transfer of blood urea across the rumen wall more extensively than changes in plasma urea concentrations. (author)

  1. Crystal Structures of GaN Nanodots by Nitrogen Plasma Treatment on Ga Metal Droplets

    Directory of Open Access Journals (Sweden)

    Yang-Zhe Su

    2018-06-01

    Full Text Available Gallium nitride (GaN is one of important functional materials for optoelectronics and electronics. GaN exists both in equilibrium wurtzite and metastable zinc-blende structural phases. The zinc-blende GaN has superior electronic and optical properties over wurtzite one. In this report, GaN nanodots can be fabricated by Ga metal droplets in ultra-high vacuum and then nitridation by nitrogen plasma. The size, shape, density, and crystal structure of GaN nanodots can be characterized by transmission electron microscopy. The growth parameters, such as pre-nitridation treatment on Si surface, substrate temperature, and plasma nitridation time, affect the crystal structure of GaN nanodots. Higher thermal energy could provide the driving force for the phase transformation of GaN nanodots from zinc-blende to wurtzite structures. Metastable zinc-blende GaN nanodots can be synthesized by the surface modification of Si (111 by nitrogen plasma, i.e., the pre-nitridation treatment is done at a lower growth temperature. This is because the pre-nitridation process can provide a nitrogen-terminal surface for the following Ga droplet formation and a nitrogen-rich condition for the formation of GaN nanodots during droplet epitaxy. The pre-nitridation of Si substrates, the formation of a thin SiNx layer, could inhibit the phase transformation of GaN nanodots from zinc-blende to wurtzite phases. The pre-nitridation treatment also affects the dot size, density, and surface roughness of samples.

  2. Uréia como fonte alternativa de nitrogênio na micropropagação de abacaxizeiro cv. Pérola = Micropropagation of pineapple cv. Pérola with urea as nitrogen source

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Moreira

    2007-12-01

    Full Text Available Objetivou-se estudar a viabilidade da substituição parcial ou total do nitrato de amônio por uréia como fonte de nitrogênio no meio de cultura para o cultivo in vitro do abacaxizeiro cv. Pérola. Plantas oriundas das gemas da coroa do fruto com massa fresca em torno de 80 mg foram inoculadas em meio MS (líquido e sólido substituindo-se 100, 80, 60, 40, 20 e 0% do nitrato de amônio por uréia. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições e três plantas/repetição. Após 60 dias,observou-se a possibilidade da substituição parcial de 40% de nitrato de amônio por uréia para as variáveis analisadas e melhor desenvolvimento das plantas em meio de cultura sólido.The partial or total substitution viability of the ammonium nitrate for urea, as source of nitrogen in the culture medium for the in vitro culture of pineapple cv. Pérola was studied. Plants originating from fruit crown buds with fresh weight matter around 80 mg was inoculated on MS medium (liquid and solid with substitution of 100, 80, 60, 40, 20 and 0% of the ammonium nitrate for urea. These treatments were arranged in a completely randomized design, with four replications and three plants/replications. After 60 days, thepossibility of 40% ammonium nitrate for urea partial substitution was observed for the analyzed variables. In addition, better plant development in solid culture medium was observed as well.

  3. Direct current plasma jet at atmospheric pressure operating in nitrogen and air

    Science.gov (United States)

    Deng, X. L.; Nikiforov, A. Yu.; Vanraes, P.; Leys, Ch.

    2013-01-01

    An atmospheric pressure direct current (DC) plasma jet is investigated in N2 and dry air in terms of plasma properties and generation of active species in the active zone and the afterglow. The influence of working gases and the discharge current on plasma parameters and afterglow properties are studied. The electrical diagnostics show that discharge can be sustained in two different operating modes, depending on the current range: a self-pulsing regime at low current and a glow regime at high current. The gas temperature and the N2 vibrational temperature in the active zone of the jet and in the afterglow are determined by means of emission spectroscopy, based on fitting spectra of N2 second positive system (C3Π-B3Π) and the Boltzmann plot method, respectively. The spectra and temperature differences between the N2 and the air plasma jet are presented and analyzed. Space-resolved ozone and nitric oxide density measurements are carried out in the afterglow of the jet. The density of ozone, which is formed in the afterglow of nitrogen plasma jet, is quantitatively detected by an ozone monitor. The density of nitric oxide, which is generated only in the air plasma jet, is determined by means of mass-spectroscopy techniques.

  4. Treatment of methyl orange by nitrogen non-thermal plasma in a corona reactor: The role of reactive nitrogen species

    Energy Technology Data Exchange (ETDEWEB)

    Cadorin, Bruno Mena, E-mail: brunomenacadorin@gmail.com [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Tralli, Vitor Douglas [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Ceriani, Elisa [Department of Chemical Sciences, Università di Padova (Italy); Benetoli, Luís Otávio de Brito [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Marotta, Ester, E-mail: ester.marotta@unipd.it [Department of Chemical Sciences, Università di Padova (Italy); Ceretta, Claudio [Department of Industrial Engineering, Università di Padova (Italy); Debacher, Nito Angelo [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Paradisi, Cristina [Department of Chemical Sciences, Università di Padova (Italy)

    2015-12-30

    Highlights: • Nitration of methyl orange is one of the main processes in treatment with N{sub 2}-plasma. • MS/MS analysis shows preferred nitration of methyl orange in ortho position. • N{sub 2} plasma, N{sub 2}-PAW, reaction with NO{sub 2}{sup −} or NO{sub 2}{sup −}/H{sub 2}O{sub 2} at pH 2 give the same products. - Abstract: Methyl orange (MO) azo dye served as model organic pollutant to investigate the role of reactive nitrogen species (RNS) in non-thermal plasma (NTP) induced water treatments. The results of experiments in which MO aqueous solutions were directly exposed to N{sub 2}-NTP are compared with those of control experiments in which MO was allowed to react with nitrite, nitrate and hydrogen peroxide, which are species formed in water exposed to N{sub 2}-NTP. Treatment of MO was also performed in PAW, Plasma Activated Water, that is water previously exposed to N{sub 2}-NTP. Both direct N{sub 2}-NTP and N{sub 2}-PAW treatments induced the rapid decay of MO. No appreciable reaction was instead observed when MO was treated with NO{sub 3}{sup −} and H{sub 2}O{sub 2} either under acidic or neutral pH. In contrast, in acidic solutions MO decayed rapidly when treated with NO{sub 2}{sup −} and with a combination of NO{sub 2}{sup −} and H{sub 2}O{sub 2}. Thorough product analysis was carried out by HPLC coupled with UV–vis and ESI–MS/MS detectors. In all experiments in which MO reaction was observed, the major primary product was a derivative nitro-substituted at the ortho position with respect to the N,N-dimethylamino group of MO. The reactions of RNS are discussed and a mechanism for the observed nitration products is proposed.

  5. Investigations of Nitrogen Oxide Plasmas: Fundamental Chemistry and Surface Reactivity and Monitoring Student Perceptions in a General Chemistry Recitation

    Science.gov (United States)

    Blechle, Joshua M.

    2016-01-01

    Part I of this dissertation focuses on investigations of nitrogen oxide plasma systems. With increasing concerns over the environmental presence of NxOy species, there is growing interest in utilizing plasma-assisted conversion techniques. Advances, however, have been limited because of the lack of knowledge regarding the fundamental chemistry of…

  6. Urease activity and its relation to soil organic matter, microbial biomass nitrogen and urea-nitrogen assimilation by maize in a Brazilian oxisol under no-tillage and tillage systems

    NARCIS (Netherlands)

    Roscoe, R.; Vasconcellos, C.A.; Furtini Neto, A.E.; Guedes, G.A.A.; Fernandes, L.A.

    2000-01-01

    We studied the relationship between urease activity (UA) and soil organic matter (SOM), microbial biomass N (Nbiom) content, and urea-N fertilizer assimilation by maize in a Dark Red Latosol (Typic Haplustox) cultivated for 9 years under no-tillage (NT), tillage with a disc plough (DP), and tillage

  7. Effect of low-damage inductively coupled plasma on shallow nitrogen-vacancy centers in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Fávaro de Oliveira, Felipe; Momenzadeh, S. Ali; Wang, Ya; Denisenko, Andrej, E-mail: a.denisenko@physik.uni-stuttgart.de [3. Institute of Physics, Research Center SCoPE and IQST, University of Stuttgart, 70569 Stuttgart (Germany); Konuma, Mitsuharu [Max Planck Institute for Solid State Research, 70569 Stuttgart (Germany); Markham, Matthew; Edmonds, Andrew M. [Element Six Innovation, Harwell Oxford, Didcot, Oxfordshire OX11 0QR (United Kingdom); Wrachtrup, Jörg [3. Institute of Physics, Research Center SCoPE and IQST, University of Stuttgart, 70569 Stuttgart (Germany); Max Planck Institute for Solid State Research, 70569 Stuttgart (Germany)

    2015-08-17

    Near-surface nitrogen-vacancy (NV) centers in diamond have been successfully employed as atomic-sized magnetic field sensors for external spins over the last years. A key challenge is still to develop a method to bring NV centers at nanometer proximity to the diamond surface while preserving their optical and spin properties. To that aim we present a method of controlled diamond etching with nanometric precision using an oxygen inductively coupled plasma process. Importantly, no traces of plasma-induced damages to the etched surface could be detected by X-ray photoelectron spectroscopy and confocal photoluminescence microscopy techniques. In addition, by profiling the depth of NV centers created by 5.0 keV of nitrogen implantation energy, no plasma-induced quenching in their fluorescence could be observed. Moreover, the developed etching process allowed even the channeling tail in their depth distribution to be resolved. Furthermore, treating a {sup 12}C isotopically purified diamond revealed a threefold increase in T{sub 2} times for NV centers with <4 nm of depth (measured by nuclear magnetic resonance signal from protons at the diamond surface) in comparison to the initial oxygen-terminated surface.

  8. Structural Transformation upon Nitrogen Doping of Ultrananocrystalline Diamond Films by Microwave Plasma CVD

    Directory of Open Access Journals (Sweden)

    Chien-Chung Teng

    2009-01-01

    Full Text Available The molecular properties and surface morphology of undoped and N-doped ultra-nanocrystalline diamond (UNCD films deposited by microwave plasma CVD with addition of nitrogen are investigated with various spectroscopic techniques. The results of spatially resolved Raman scattering, ATR/FT-IR and XPS spectra show more amorphous and sp2/sp3 ratio characteristics in N-doped UNCD films. The surface morphology in AFM scans shows larger nanocrystalline diamond clusters in N-doped UNCD films. Incorporation of nitrogen into UNCD films has promoted an increase of amorphous sp2-bonded carbons in the grain boundaries and the size of nanocrystalline diamond grains that are well correlated to the reported enhancement of conductivity and structural changes of UNCD films.

  9. Effect of abomasal infusion of oligofructose on portal-drained visceral ammonia and urea-nitrogen fluxes in lactating Holstein cows

    DEFF Research Database (Denmark)

    Røjen, Betina Amdisen; Larsen, Mogens; Kristensen, Niels Bastian

    2012-01-01

    by reduced NH3 input to hepatic urea-N synthesis caused by increased sequestration of NH3 in the hindgut and excretion in feces. Increasing the hindgut fermentation in lactating dairy cows by abomasal infusion of 1,500 g/d of oligofructose shifted some N excretion from the urine to feces and possibly reduced......The effects of abomasal infusion of oligofructose in lactating dairy cows on the relationship between hindgut fermentation and N metabolism, and its effects on NH3 absorption and transfer of blood urea-N across the portal-drained viscera versus ruminal epithelia were investigated. Nine lactating...... treatments. Eight sample sets of arterial, portal, hepatic, and ruminal vein blood, ruminal fluid, and urine were obtained at 0.5 h before the morning feeding and at 0.5, 1.5, 2.5, 3.5, 4.5, 5.5, and 6.5 h after feeding. It was hypothesized that an increased supply of fermentable substrate to the hindgut...

  10. Effects of dietary nitrogen concentration on messenger RNA expression and protein abundance of urea transporter-B and aquaporins in ruminal papillae from lactating Holstein cows

    DEFF Research Database (Denmark)

    Røjen, Betina Amdisen; Poulsen, Søren Brandt; Theil, Peter Kappel

    2011-01-01

    To test the hypothesis that dietary N concentrations affect gut epithelial urea transport by modifying the expression of urea transporter B (UT-B) and aquaporins (AQP), the mRNA expression and protein abundance of UT-B and AQP3, AQP7, AQP8, and AQP10 were investigated in ruminal papillae from 9...... lactating dairy cows. Ruminal papillae were harvested from cows fed low N (12.9% crude protein) and high N (17.1% crude protein) diets in a crossover design with 21-d periods. The mRNA expression was determined by real-time reverse transcription-PCR and protein abundance by immunoblotting. The m......RNA expression of UT-B was not affected by dietary treatment, whereas mRNA expression of AQP3, 7, and 10 were greater in the high N compared with the low N fed cows. Using peptide-derived rabbit antibodies to cow AQP3, 7, and 8, immunoblotting revealed bands of approximately 27, 27, and 24 kDa in ruminal...

  11. Nitrogen Metabolism in Lactating Goats Fed with Diets Containing Different Protein Sources

    Directory of Open Access Journals (Sweden)

    A. B. Santos

    2014-05-01

    Full Text Available This study aimed to evaluate urea excretion, nitrogen balance and microbial protein synthesis in lactating goats fed with diets containing different protein sources in the concentrate (soybean meal, cottonseed meal, aerial part of cassava hay and leucaena hay. Four Alpine goats whose mean body weight was 42.6±6.1 kg at the beginning of the experiment, a mean lactation period of 94.0±9.0 days and a production of 1.7±0.4 kg of milk were distributed in a 4×4 Latin square with four periods of 15 days. Diets were formulated to be isonitrogenous, containing 103.0 g/kg of CP, 400 g/kg of Tifton 85 hay and 600 g/kg of concentrate. Diet containing cottonseed meal provided (p<0.05 increased excretion of urea and urea nitrogen in the urine (g/d and mg/kg of BW when compared with leucaena hay. The diets affected the concentrations of urea nitrogen in plasma (p<0.05 and excretion of urea nitrogen in milk, being that soybean meal and cottonseed meal showed (p<0.05 higher than the average aerial part of the cassava hay. The use of diets with cottonseed meal as protein source in the concentrate in feeding of lactating goats provides greater nitrogen excretion in urine and negative nitrogen balance, while the concentrate with leucaena hay as a source of protein, provides greater ruminal microbial protein synthesis.

  12. Production and levels of foliar nitrogen in rocket salad fertilized with controlled-release nitrogen fertilizers and urea Produção e teor de nitrogênio foliar em rúcula adubada com fertilizantes nitrogenados de liberação lenta e uréia

    Directory of Open Access Journals (Sweden)

    Rafael Felippe Ratke

    2011-06-01

    Full Text Available Controlled-release nitrogen fertilizers enhance crop productivity and decrease nitrogen loss through volatilization and leaching. This study aimed at determining the effect of nitrogen treatments provided by controlled-release nitrogen fertilizers and urea. The following fertilizers were tested: 1 (agricultural urea, 2 (ammonium sulfonitrate + nitrification inhibitor, dimethylpyrazole phosphate (Entec 26®,3 (urea + Kimberlit polymer (Kimcoat N® and 4 (urea + NBPT (Super N - Agrotain®. Treatments corresponded to 0, 100, 200, 400 and 800 kg ha-1 of N with rocket salad grown inside a greenhouse, assessing the production of fresh and dry leaf mass as well as levels of foliar nitrogen. Doses of different controlled-release nitrogen fertilizers showed significant polynomial regressions for the production of rocket salad fresh leaf mass and levels of foliar nitrogen, whereby Entec 26® did not show significant polynomial regression, considering the last parameter evaluated. The production of rocket salad dry leaf mass did not display significant linear regressions. The maximal production of rocket salad fresh leaf mass was reached at doses of 600, 490, 765, and 462 kg ha-1 of N with the use of urea, Entec 26®, Kimcoat N® and Super N®, respectively.Os fertilizantes nitrogenados de liberação lenta aumentam a produtividade das culturas e diminuem as perdas de nitrogênio por volatilização e lixiviação. O objetivo deste trabalho foi determinar, no cultivo de rúcula, o efeito de doses de N fornecidas por fertilizantes nitrogenados de liberação lenta e pela uréia. Testaram-se os fertilizantes: 1 (uréia agrícola, 2 (sulfonitrato de amônio + inibidor de nitrificação Dimetil Pirazol Fosfato (Entec 26®,3 (uréia + polímero Kimberlit (kimcoat N® e 4 (uréia + NBPT (Super N - Agrotain®, e as doses de 0, 100, 200, 400 e 800 kg ha-1 de N em rúcula crescidas em casa de vegetação, avaliando-se a produtividade de matéria fresca de folhas

  13. Computational regulatory model for detoxification of ammonia from urea cycle in liver

    OpenAIRE

    ALI, Rashith Muhammad MUBARAK; GURUSAMY, Poornima Devi; RAMACHANDRAN, Selvakumar

    2015-01-01

    A nondeterministic finite automaton was designed to monitor enzymatic regulation and detoxification of excess ammonia in the urea cycle and its disorders. The designed machine is used for the diagnosis of deficiency and for regulating the expression of any of the enzymes involved with acceptance and rejection states in the urea cycle. The urea cycle is the metabolism of excess nitrogen produced by the breakdown of protein and other nitrogen-containing molecules in liver. Disorder in the urea ...

  14. Tribological properties of nitrogen-containing amorphous carbon film produced by dc plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Zhang Wei; Wazumi, Koichiro; Tanaka, Akihiro; Koga, Yoshinori

    2003-01-01

    The nitrogen-contained amorphous carbon (a-C:N) films were deposited in a dc plasma chemical vapor deposition system with different substrate bias voltages. The structural, mechanical, and tribological properties of the a-C:N films were investigated. The influence of the bias voltage on the tribological behaviors of the a-C:N films was evaluated under various environments (dry air, O 2 , N 2 , and vacuum) using a ball-on-disk friction tester. It showed that the sp 3 C and hydrogen concentration of the a-C:N films decreases with increasing the bias voltage. However, the nitrogen concentration increases with increasing the bias voltage. As a result, the hardness and internal stress decrease and the critical load for fracturing increases as the substrate bias increases. For the tribological properties of the a-C:N films, the friction coefficient of the films slightly decreases in the environments of N 2 , O 2 , or dry air, but increases slightly in the vacuum environment by increasing the bias voltage. It indicates that the incorporated nitrogen in the a-C:N films would decrease the friction coefficient of the films in N 2 or O 2 environments, but slightly increases the friction coefficient of the films in a vacuum. The excellent wear resistance of the a-C:N films, in the level of 10 -9 -10 -8 mm 3 /Nm, can be observed in N 2 , vacuum, and dry air environments. In addition, the effect of the bias voltage on the wear rate of the a-C:N films becomes less obvious by nitrogen incorporation. So, we suggest the incorporated nitrogen, which bonded to carbon and restrained the increase of the fraction of sp 2 C-C, would restrain the wear of the a-C:N films in different environments, especially in dry air

  15. Urea retranslocation from senescing Arabidopsis leaves is promoted by DUR3-mediated urea retrieval from leaf apoplast

    Science.gov (United States)

    Bohner, Anne; Kojima, Soichi; Hajirezaei, Mohammad; Melzer, Michael; von Wirén, Nicolaus

    2015-01-01

    In plants, urea derives either from root uptake or protein degradation. Although large quantities of urea are released during senescence, urea is mainly seen as a short-lived nitrogen (N) catabolite serving urease-mediated hydrolysis to ammonium. Here, we investigated the roles of DUR3 and of urea in N remobilization. During natural leaf senescence urea concentrations and DUR3 transcript levels showed a parallel increase with senescence markers like ORE1 in a plant age- and leaf age-dependent manner. Deletion of DUR3 decreased urea accumulation in leaves, whereas the fraction of urea lost to the leaf apoplast was enhanced. Under natural and N deficiency-induced senescence DUR3 promoter activity was highest in the vasculature, but was also found in surrounding bundle sheath and mesophyll cells. An analysis of petiole exudates from wild-type leaves revealed that N from urea accounted for >13% of amino acid N. Urea export from senescent leaves further increased in ureG-2 deletion mutants lacking urease activity. In the dur3 ureG double insertion line the absence of DUR3 reduced urea export from leaf petioles. These results indicate that urea can serve as an early metabolic marker for leaf senescence, and that DUR3-mediated urea retrieval contributes to the retranslocation of N from urea during leaf senescence. PMID:25440717

  16. Produção de proteína microbiana, concentração plasmática de uréia e excreções de uréia em novilhos alimentados com diferentes níveis de uréia ou casca de algodão Effects of feeding different levels of urea or cottonseed hulls on microbial protein synthesis, plasma urea concentration and urea excretion in steers

    Directory of Open Access Journals (Sweden)

    Karla Alves Magalhães

    2005-08-01

    Full Text Available Com o objetivo de avaliar os efeitos dos níveis de uréia ou casca de algodão sobre a produção de proteína microbiana, estimada por meio dos derivados de purinas na urina, a concentração de uréia plasmática (NUP e as excreções de uréia em novilhos, foram realizados dois experimentos. No primeiro, 24 novilhos mestiços castrados, com peso vivo médio inicial de 300 kg, foram alocados em delineamento inteiramente casualizado, nos quatro tratamentos: 0; 0,65; 1,30 e 1,95% de uréia na base da MS total, em substituição à proteína do farelo de soja. No segundo, 16 novilhos mestiços, com peso vivo médio inicial de 230 kg, foram distribuídos em delineamento inteiramente casualizado, nos quatro tratamentos: 0, 10, 20 e 30% de casca de algodão na base da MS total, em substituição à silagem de capim-elefante. As amostras de urina foram obtidas por meio da coleta de urina spot, na qual foram determinados os derivados de purinas (alantoína e ácido úrico. No soro sanguíneo e na urina, foram analisadas as concentrações de uréia e creatinina. Não houve efeito dos níveis de uréia, tampouco dos de casca de algodão, sobre os derivados de purinas e sobre a eficiência de síntese microbiana. A concentração de NUP e a excreção de uréia não foram influenciadas pelos níveis de uréia das rações. A concentração de NUP decresceu linearmente com a inclusão da casca de algodão na dieta. Tanto a uréia quanto a casca de algodão podem ser utilizadas, até os níveis de 1,95% e 30%, respectivamente, na MS total da dieta de novilhos de origem leiteira, sem afetar a eficiência de síntese microbiana.Two trials were conducted to study the effects of different levels of urea or cottonseed hulls on yield of microbial protein, estimated by the urinary excretion of purine derivatives, concentration of plasma urea, and excretion of urea in steers. In the first trial, 24 crossbred castrated steers averaging 300 kg of initial live

  17. Nitrogen excretion during embryonic development of the green iguana, Iguana iguana (Reptilia; Squamata).

    Science.gov (United States)

    Sartori, M R; Taylor, E W; Abe, A S

    2012-10-01

    Development within the cleidoic egg of birds and reptiles presents the embryo with the problem of accumulation of wastes from nitrogen metabolism. Ammonia derived from protein catabolism is converted into the less toxic product urea or relatively insoluble uric acid. The pattern of nitrogen excretion of the green iguana, Iguana iguana, was determined during embryonic development using samples from allantoic fluid and from the whole homogenized egg, and in hatchlings and adults using samples of blood plasma. Urea was the major excretory product over the course of embryonic development. It was found in higher concentrations in the allantoic sac, suggesting that there is a mechanism present on the allantoic membrane enabling the concentration of urea. The newly hatched iguana still produced urea while adults produced uric acid. The time course of this shift in the type of nitrogen waste was not determined but the change is likely to be related to the water relations associated with the terrestrial habit of the adult. The green iguana produces parchment-shelled eggs that double in mass during incubation due to water absorption; the eggs also accumulate 0.02 mM of urea, representing 82% of the total measured nitrogenous residues that accumulate inside the allantois. The increase in egg mass and urea concentration became significant after 55 days of incubation then were unchanged until hatching. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Nitrogen gas plasma treatment of bacterial spores induces oxidative stress that damages the genomic DNA.

    Science.gov (United States)

    Sakudo, Akikazu; Toyokawa, Yoichi; Nakamura, Tetsuji; Yagyu, Yoshihito; Imanishi, Yuichiro

    2017-01-01

    Gas plasma, produced by a short high‑voltage pulse generated from a static induction thyristor power supply [1.5 kilo pulse/sec (kpps)], was demonstrated to inactivate Geobacillus stearothermophilus spores (decimal reduction time at 15 min, 2.48 min). Quantitative polymerase chain reaction and enzyme‑linked immunosorbent assays further indicated that nitrogen gas plasma treatment for 15 min decreased the level of intact genomic DNA and increased the level of 8-hydroxy-2'-deoxyguanosine, a major product of DNA oxidation. Three potential inactivation factors were generated during operation of the gas plasma instrument: Heat, longwave ultraviolet-A and oxidative stress (production of hydrogen peroxide, nitrite and nitrate). Treatment of the spores with hydrogen peroxide (3x2‑4%) effectively inactivated the bacteria, whereas heat treatment (100˚C), exposure to UV-A (75‑142 mJ/cm2) and 4.92 mM peroxynitrite (•ONOO‑), which is decomposed into nitrite and nitrate, did not. The results of the present study suggest the gas plasma treatment inactivates bacterial spores primarily by generating hydrogen peroxide, which contributes to the oxidation of the host genomic DNA.

  19. Nitrogen capillary plasma as a source of intense monochromatic radiation at 2.88 nm

    Energy Technology Data Exchange (ETDEWEB)

    Vrba, P., E-mail: vrbovmir@fbmi.cvut.cz [Institute of Plasma Physics, Academy of Sciences, Za Slovankou 3, Prague 8 (Czech Republic); Vrbova, M. [Faculty of Biomedical Engineering, CTU in Prague, Sitna 3105, Kladno 2 (Czech Republic); Zakharov, S.V. [EPPRA sas, Villebon/Yvette (France); Zakharov, V.S. [EPPRA sas, Villebon/Yvette (France); KIAM RAS, Moscow (Russian Federation); Jancarek, A.; Nevrkla, M. [Faculty of Nuclear Science and Physical Engineering, CTU in Prague, Brehova 7, Prague 1 (Czech Republic)

    2014-10-15

    Highlights: • Pinching capillary discharge is studied as a source of monochromatic SXR. • Modeling of the laboratory device was performed by RMHD Z* code. • Results of computer and laboratory experiments are presented. - Abstract: Capillary discharge plasma related to our laboratory device is modeled and the results are compared with experimental data. Time dependences of selected plasma quantities (e.g. plasma mass density, electron temperature and density and emission intensities) evaluated by 2D Radiation-Magneto-Hydro-Dynamic code Z* describe plasma evolution. The highest output pulse energy at 2.88 nm wavelength is achieved for nitrogen filling pressure ∼100 Pa. The estimated output energy of monochromatic radiation 5.5 mJ sr{sup −1} (∼10{sup 14} photons sr{sup −1}) corresponds properly to observe experimental value ∼3 × 10{sup 13} photons sr{sup −1}. Ray tracing inspection along the capillary axis proves an influence of radiation self-absorption for the investigated wavelength. The spectra, evaluated using the FLY code, agree to the measured ones.

  20. Transfer of blood urea into the goat colon

    International Nuclear Information System (INIS)

    Engelhardt, W. von; Hinderer, S.

    1976-01-01

    Transfer of body urea into the temporarily isolated and perfused colon of conscious goats was measured. Simultaneously total urea turnover was estimated using 14 C-urea. The transfer of urea into the total gastrointestinal tract (total turnover minus renal excretion) was four times higher with the high-energy - low-protein diet (sugar pulp plus straw) compared with control feeding (hay ad lib.). The transfer of urea into the colon was 8% of the transfer into the total GI tract during control feeding, 14% when food was withheld for 48 hours and 1% during sugar pulp feeding. The transfer into the colon depends mainly on the plasma urea concentration, whereas in the proximal part of the GI tract changes in the permeability of the GI tract wall have a more pronounced influence than plasma urea concentration. (author)

  1. Entry of blood urea into the rumen of the llama

    International Nuclear Information System (INIS)

    Hinderer, S.; Engelhardt, W. von

    1976-01-01

    Llamas were provided with a large rumen fistula, and the transfer of blood urea into the temporarily isolated rumen, cleaned and filled with test solution was measured. Plasma urea clearance due to transfer of blood urea across the rumen wall should indicate changes in its permeability to urea. Clearance values were highest with CO 2 or with high concentrations of butyric acid. Permeability was low when food was with-held and when no volatile fatty acids were present in the solution. The permeability of the rumen wall to blood urea can be altered significantly. These changes can affect blood urea transfer more extensively than changes in the plasma urea concentration within physiological ranges

  2. Effect of urea supplemented and urea treated straw based diet on milk urea concentration in crossbred Karan-Fries cows

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Sirohi

    2010-01-01

    Full Text Available The study was undertaken to evaluate the effect of urea supplemented and urea treated straw based diet on milk ureaconcentration. Six multiparous crossbred Karan-Fries (Holstein Friesian ✕ Tharparkar cows were blocked into threegroups of nearly equal body weight, DIM, milk yield and milk fat content and were randomized into a 3 ✕ 3 Latin squaredesign with 3-week period. Three experimental diets were fed to the animals. Composition of these diets were: Diet 1green maize, wheat straw and concentrate mixture; Diet 2 green maize, wheat straw, concentrate mixture (urea supplementedand molasses; Diet 3 green maize (4 % of total DM, 4 % urea treated wheat straw and concentrate mixture.Intake of DM and CP did not vary across the diets. Intake of digestible crude protein (DCP was found significantlyhigher in diet 2, while ME and NEL intakes were found significantly lower in diet 3 but did not differ between diets 1and 2. Average milk and plasma urea concentrations (mg dl-1 were found 29.2 ± 2.6, 45.3 ± 0.9, 34.5 ± 2.3 and 28.9± 2.4, 36.6 ± 1.4, 33.9 ± 2.2, respectively in diet 1, diet 2 and diet 3. Urea concentrations in morning milk sampleswere found significantly lower than noon or evening samples in all the three diets. Concentrations of urea in milk andplasma were found closely correlated (r = 0.94 and the regression equation developed was, plasma urea = 8.90 (.89+ .79 (.02 milk urea. Intake (g of DCP than CP, per unit (MCal of ME was found more closely associated with milk ureaconcentration. The study revealed that urea supplementation and urea treated straw based diet increased urea concentrationsignificantly in milk and plasma. Morning milk urea values that estimated at a time gap of 15 hr since last majorfeeding may be considered as the lowest level and can be used for interpretation to monitor feeding adequacy or reproductiveperformances in dairy cows.

  3. Urea hydrolysis and ammonia volatilization from some urea based fertilizers applied to rice

    International Nuclear Information System (INIS)

    Misra, C.; Jena, D.; Bandyopadhyay, K.K.; Schepers, J.S.

    1995-01-01

    Field experiments were carried out in replicated microplots (1 m x 1 m) with rice (cv. Pathara) to study urea hydrolysis using several urea based N-fertilizer sources. Results indicated highly significant urea based N-fertilizers, among which urea super granule (USG) and prilled urea (PU) (applied in two splits) could be rated as the most efficient sources of N. Based on measured ammonia volatilization loss, NH 2 -N concentration in flood water and soil solution (following fertilizer application); urea hydrolysis was observed to be faster in the case of PU, USG, PU + ECC (encapsulated calcium carbide) and UNP (urea nitro phosphate) (19-19-0) than in the case of GCU (gypsum coated urea) and UNP (27-9-0) treatments. Based on the 15 N tagged prilled urea experiment, it is observed that about 24 per cent of fertilizer nitrogen was utilized by the crop in closed system as compared to 18 per cent in natural free system. (author). 5 refs., 2 figs., 4 tabs

  4. Limited seed and seed yield response of calendula to applied nitrogen does not justify risk of environmental damage from high urea application rates

    Science.gov (United States)

    Calendula (Calendula officinalis L.) is a source of industrial oil, which can serve as a domestic substitute for petroleum or imported specialty crop oils. Traditionally, calendula has been grown for medicinal or ornamental properties. However, little is known about nitrogen (N) requirement of growi...

  5. Utilization of 15N-labelled urea in laying hens. 4

    International Nuclear Information System (INIS)

    Gruhn, K.; Hennig, A.

    1986-01-01

    In order to study the utilization of urea in poultry, 3 colostomized laying hybrids were orally supplied with a traditional ration supplemented with 1% 15 N'-labelled urea with a 15 N excess ( 15 N') of 96.06 atom-% over a period of 6 days. After another 2 days on which the hens received the same ration with unlabelled urea, they were killed. The atom-% 15 N' of the blood on an average of the 3 hens was 0.64, of the plasma 1.40 and of the corpuscles 0.47. The TCA-soluble fraction of the blood had an average 15 N' of 1.14 atom-%; the 15 N amount was 9.7% of the total amount of 15 N in the blood. The amount of 15 N' in the urea in the blood was 6.8 atom-%. This shows that the absorbed urea is decomposed very slowly. The quota of 15 N' in the basic amino acids from the total 15 N' of the blood plasma was only 0.3% and that of the corpuscles 2.2%. The average 15 N' of the mature follicles was 2.39 atom-% whereas the smallest and the remaining ovary contain 1.12 atom-%. The labelling level of lysine in mature egg cells was, in contrast to this, only 0.08 atom-% 15 N' and in infantile follicles 0.04 atom-% 15 N'. 1% of the 15 N' quota was in the follicles and the remaining ovary. Of the basic amino acids, histidine is most strongly labelled. The lower incorporation of the 15 N' from urea into the basic amino acids shows that the nitrogen of this compound can be used for the synthesis of the essential amino acids to a low degree only. (author)

  6. Measurement of urea kinetics in vivo by means of a constant tracer infusion of di-15N-urea

    International Nuclear Information System (INIS)

    Wolfe, R.R.

    1981-01-01

    We have assessed the feasibility of studying urea metabolism in vivo in both steady state and nonsteady state situations by means of the primed constant infusion of di-15N-urea and the analysis of the resulting enrichment in plasma urea. Both hepatectomized dogs with known rates of urea infusion and intact dogs were studied. The enrichment of the bistrimethylsilyl derivative of urea was determined on a gas chromatograph-mass spectrometer. Selected ion monitoring was set for m/e 189 (M - 15), m/e 190 (A + 1), and m/e 191 (A + 2), thus enabling the calculation of the rate of urea production from nonrecycled NH3 (from A + 2 data) (Ra N), the rate of recycling of NH3 into urea (Ra R) (from A + 1 data), and thus the total rate of urea production (Ra N + Ra R). When urine collections were made, the incorporation of urea-N into protein was estimated from the difference between Ra N and urea excretion. We found that, in the steady state in a hepatectomized dog, the rate of appearance of urea can be determined accurately. In the nonsteady state in both hepatectomized and intact dogs, urea appearance could be estimated within +/- 20% in most situations. The only situation in which this was not the case was when we attempted to measure rapid changes in Ra R. Thus, within limits, this can be a useful technique enabling the quantitation of various aspects of urea metabolism

  7. Scaling Laws of Nitrogen Soft X-Ray Yields from 1 to 200 kJ Plasma Focus

    International Nuclear Information System (INIS)

    Akel, M.; Lee, S.

    2013-01-01

    Numerical experiments are carried out systematically to determine the nitrogen soft x-ray yield for optimized nitrogen plasma focus with storage energy E 0 from 1 kJ to 200 kJ. Scaling laws on nitrogen soft x-ray yield, in terms of storage energies E 0 , peak discharge current I p eak and focus pinch current I p inch were found. It was found that the nitrogen x-ray yields scales on average with y s xr, N= 1.93xE o 1 .21 J (E 0 in kJ) with the scaling showing gradual deterioration as E 0 rises over the range. A more robust scaling is y s xr = 8x10 - 8I 0 3.38 p inch . The optimum nitrogen soft x-ray yield emitted from plasma focus is found to be about 1 kJ for storage energy of 200 kJ. This indicates that nitrogen plasma focus is a good water-window soft x-ray source when properly designed. (author)

  8. Urea in Milk

    OpenAIRE

    Projectsatbangalore

    2017-01-01

    This paper describes the design of a low-cost, portable instrument using CO2 and NH3 gas sensor technology to quantify and differentiate milk samples containing excess urea. Milk containing urea, in presence of urease enzyme hydrolyses urea to form ammonia and carbon dioxide.

  9. Impact of nitrogen plasma passivation on the Al/n-Ge contact

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Shumei; Mao, Danfeng [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Ruan, Yujiao [Xiamen Institute of Measurement and Testing, Xiamen, Fujian 361004 (China); Xu, Yihong; Huang, Zhiwei; Huang, Wei [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Chen, Songyan, E-mail: sychen@xmu.edu.cn [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Li, Cheng; Wang, Jianyuan [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Tang, Dingliang [College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China)

    2016-09-15

    Highlights: • A thin GeO{sub x}N{sub y} layer was formed by N{sub 2} plasma. • The principal parameters of N{sub 2} plasma treatment and additional post anneal have a great impact on the Al/n-Ge contact. • A model was proposed to explain the variation of Schottky barrier height. • The GeO{sub x}N{sub y} layer was also benefit to achieve a low leakage current density for HfO{sub 2}/Ge MOS capacitors. - Abstract: Severe Fermi level pinning at the interface of metal/n-Ge leads to the formation of a Schottky barrier. Therefore, a high contact resistance is introduced, debasing the performance of Ge devices. In this study, a Ge surface was treated by nitrogen plasma to form an ultra-thin Germanium oxynitride (GeO{sub x}N{sub y}) passivation layer. It was found that the Schottky barrier height (SBH) of metal/n-Ge contact was strongly modulated by the GeO{sub x}N{sub y} interlayer, indicating alleviation of Fermi-level pinning effect. By adjusting the principal parameters of N{sub 2} plasma treatment and additional post anneal, a Quasi-ohmic Al/n-Ge contact was achieved. Furthermore, the introduced GeO{sub x}N{sub y} layer gave extremely lower leakage current density of the gate stack for HfO{sub 2}/Ge devices. These results demonstrate that GeO{sub x}N{sub y} formed by N{sub 2} plasma would be greatly beneficial to the fabrication of the Ge-based devices.

  10. Limited Seed and Seed Yield Response of Calendula to Applied Nitrogen Does Not Justify Risk of Environmental Damage from High Urea Application Rates

    OpenAIRE

    Jane M. F. Johnson; Russ W. Gesch; Nancy W. Barbour

    2018-01-01

    Calendula (Calendula officinalis L.) seed, due to its high calendic acid content, is recognized as a potential environmentally safe substitute for volatile organic compounds. Agronomic guidelines for nitrogen (N) management to produce calendula seed oil on a commercial scale are limited. Post-harvest soil N has the potential to move off-farm and contribute to water quality degradation (e.g., hypoxia in the Gulf of Mexico). Establishing N management guidelines should consider agronomic respons...

  11. Rumen Microbial Protein Production in Rumen-Simulating-Technique (RUSITEC) Using 15N-Urea Nitrogen, as Influenced By Hay and Barley Ratios in Feed

    International Nuclear Information System (INIS)

    Al-Masri, M. R.; Abel, HJ.; Steinberg, W.

    2004-01-01

    Metabolism of dietary nitrogen using labeled 15 N and the changes in the microbial protein mass and NH3-N were studied in five rumen-simulating-technique(RUSITEC)-fermenters, which were run simultaneously in three identically repeated experiments. Each experiment consisted of a 6-day adaptation period followed directly by a 3-day collection period. The feed of the fermenters (G1, G2, G3, G4 and G5) varied in the ratio of barley. The barley increased by 20% between the fermenters. Grass hay+barley (g/d) in the feed of the fermenters was 10+2 (G1), 8+4 (G2), 6+6 (G3), 4+8 (G4) and 2+10 (G5). The results indicated that there were no significant (P>0.05) changes in the amounts of microbial nitrogen (92-118 mg/d) and microbial mass syntheses which were (mg/d): 1154 (G1), 1063 (G2), 1152 (G3), 1127 (G4) and 1362 (G5). Increasing the proportion of barley in the fermenters (G4 and G5) decreased NH3-N amounts (G2 and G3) significantly (P<0.05). The energy was not efficiently used in G5 having a lower ratio of the microbial nitrogen and microbial mass to the total short chain fatty acids than that other fermenters. (authors)

  12. Ammonia volatilization from coated urea forms

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Costa do Nascimento

    2013-08-01

    Full Text Available Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N volatilization losses in sugar cane harvested after stubble burning. The sources urea, sulfur-coated urea, urea coated with boric acid and copper sulfate, as well as nitrate and ammonium sulfate, were tested at amounts containing N rates of 120 kg ha-1 N. The integration of new technologies in urea fertilization can reduce N losses by volatilization. These losses were most reduced when using nitrate and ammonium sulfate. The application of a readily acidified substance (boric acid to urea was more efficient in reducing volatilization losses and nutrient removal by sugar cane than that of a substance with gradual acidification (elemental sulfur.

  13. Fast photography of XeCl laser-induced plasma of graphite in vacuum and in nitrogen atmosphere

    International Nuclear Information System (INIS)

    Acquaviva, S; De Giorgi, M L

    2003-01-01

    Fast photography with a gated intensified close-coupled device camera was applied to provide a visualization of the temporal and spatial evolution of chemical species in a plasma induced by a 308 nm laser during graphite ablation, in vacuum and in nitrogen atmosphere. A sequence of frames of the luminous plume was recorded, using narrow interference filters, and plasma expansion velocity was estimated from the acquired images. Present observations agree with optical emission spectroscopic investigations performed under the same experimental conditions

  14. Balanço de nitrogênio, concentrações de ureia e síntese de proteína microbiana em caprinos alimentados com dietas contendo cana-de-açúcar tratada com óxido de cálcio Nitrogen balance, urea concentrations and microbial protein synthesis in goats fed diets containing sugar cane treated with calcium oxide

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2010-10-01

    Full Text Available Objetivou-se avaliar o efeito da hidrólise da cana-de-açúcar com óxido de cálcio (CaO sobre o balanço de nitrogênio, as concentrações de ureia na urina e no plasma e a síntese na proteína microbiana em caprinos. Foram utilizados oito caprinos da raça Saanen, machos castrados, com peso corporal médio de 22,6 kg e 4 meses de idade, distribuídos em dois quadrados latinos 4 õ 4, em quatro períodos experimentais de 14 dias. As rações, formuladas para ser isoproteicas, com 14% de proteína bruta (PB, foram compostas de 70% de cana-de-açúcar (tratada com 0; 0,75; 1,5 ou 2,25% de óxido de cálcio na matéria natural e corrigida com 1% de ureia e 30% de concentrado e fornecidas à vontade. A cana-de-açúcar com óxido de cálcio foi picada em desintegrador estacionário, pesada, acondicionada em baldes plásticos de 50 litros e tratada com o óxido de cálcio para ser fornecida aos animais após 24 horas de armazenamento. O balanço de nitrogênio, as concentrações de ureia na urina e no plasma e as excreções de ureia na urina não foram influenciadas pelo tratamento da cana-de-açúcar com óxido de cálcio. A concentração de alantoína (% das purinas totais foi maior e a de ácido úrico menor nas dietas com cana-de-açúcar hidrolisada com óxido de cálcio em relação à cana in natura. A produção e a eficiência microbiana não foram afetadas pela adição de óxido de cálcio à cana-de-açúcar em dietas para caprinos em crescimento.The objective of this work was to evaluate the effect of sugar cane hydrolysis with calcium oxide (CaO on nitrogen balance, concetrations of urea in the urine and in the plasma and synthesis in microbial protein in goats. Eight castrated male Saanen breed goats, with 22.6 kg average body weight and at four months of age were used distributed in two 4 õ 4 Latin squares, during four 14-day experimental periods. The rations which were formulated to be isoprotein, with 14% crude protein (CP

  15. Langmuir probe diagnostics of an atmospheric pressure, vortex-stabilized nitrogen plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Prevosto, L.; Mancinelli, B. R. [Grupo de Descargas Electricas, Departamento Ingenieria Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, (2600) Venado Tuerto, Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Electricas, Departamento Ingenieria Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, (2600) Venado Tuerto, Santa Fe (Argentina) and Instituto de Fisica del Plasma (CONICET), Departamento de Fisica, Facultad de Ciencias Exactas y Naturales UBA Ciudad Universitaria Pab. I, (1428) Buenos Aires (Argentina)

    2012-09-15

    Langmuir probe measurements in an atmospheric pressure direct current (dc) plasma jet are reported. Sweeping probes were used. The experiment was carried out using a dc non-transferred arc torch with a rod-type cathode and an anode of 5 mm diameter. The torch was operated at a nominal power level of 15 kW with a nitrogen flow rate of 25 Nl min{sup -1}. A flat ion saturation region was found in the current-voltage curve of the probe. The ion saturation current to a cylindrical probe in a high-pressure non local thermal equilibrium (LTE) plasma was modeled. Thermal effects and ionization/recombination processes inside the probe perturbed region were taken into account. Averaged radial profiles of the electron and heavy particle temperatures as well as the electron density were obtained. An electron temperature around 11 000 K, a heavy particle temperature around 9500 K and an electron density of about 4 Multiplication-Sign 10{sup 22} m{sup -3}, were found at the jet centre at 3.5 mm downstream from the torch exit. Large deviations from kinetic equilibrium were found throughout the plasma jet. The electron and heavy particle temperature profiles showed good agreement with those reported in the literature by using spectroscopic techniques. It was also found that the temperature radial profile based on LTE was very close to that of the electrons. The calculations have shown that this method is particularly useful for studying spraying-type plasma jets characterized by electron temperatures in the range 9000-14 000 K.

  16. Laser induced aluminiun plasma analysis by optical emission spectroscopy in a nitrogen background gas

    International Nuclear Information System (INIS)

    Chamorro, J C; Uzuriaga, J; Riascos, H

    2012-01-01

    We studied an Al plasma generated by a Nd:YAG laser with a laser fluence of 4 J/cm 2 , a wavelength of 1064 nm, energy pulse of 500 mJ and 10 Hz repetition rate. We studied their spectral characteristics at various ambient nitrogen pressures by optical emission spectroscopy (OES). The N 2 gas pressure was varied from 20 mTorr to 150 mTorr. In Al plume, both atomic and ionic spectra were observed. The electron temperature and electron number density of the plume as of the function ambient gas pressure were determined. The electron temperature was calculated by using the Boltzmann-plot method and the number density was calculated considering the stark effect as dominating on the emission lines.

  17. Effect of near atmospheric pressure nitrogen plasma treatment on Pt/ZnO interface

    International Nuclear Information System (INIS)

    Nagata, Takahiro; Haemori, Masamitsu; Chikyow, Toyohiro; Yamashita, Yoshiyuki; Yoshikawa, Hideki; Kobayashi, Keisuke; Uehara, Tsuyoshi

    2012-01-01

    The effect of near atmospheric pressure nitrogen plasma (NAP) treatment of platinum (Pt)/zinc oxide (ZnO) interface was investigated. NAP can nitride the ZnO surface at even room temperature. Hard x-ray photoelectron spectroscopy revealed that NAP treatment reduced the surface electron accumulation at the ZnO surface and inhibited the Zn diffusion into the Pt electrode, which are critical issues affecting the Schottky barrier height and the ideality factor of the Pt/ZnO structure. After NAP treatment, the Pt Schottky contact indicated an improvement of electrical properties. NAP treatment is effective for the surface passivation and the Schottky contact formation of ZnO.

  18. Substituição de uréia por cloreto de amônio em dietas de bovinos: digestibilidade, síntese de proteína microbiana, parâmetros ruminais e sanguíneos - DOI: 10.4025/actascianimsci.v31i3.5938 Replacing urea with ammonium chloride in cattle diets: digestibility, synthesis of microbial protein, and rumen and plasma parameters - DOI: 10.4025/actascianimsci.v31i3.5938

    Directory of Open Access Journals (Sweden)

    Julio Cesar Barreto

    2009-09-01

    Full Text Available Foram utilizados cinco bovinos machos, castrados, da raça Holandesa Preta e Branca, com 450 kg de peso vivo em um delineamento quadrado latino 5 x 5, sendo os tratamentos cinco níveis de substituição, 0, 25, 50, 75 e 100% de ureia por cloreto de amônio, como fontes de nitrogênio não-proteico da dieta. Houve redução linear (p 0,05 a excreção de alantoína e de derivados de purinas na urina, purinas absorvidas, síntese de compostos nitrogenados microbianos e eficiência de síntese de proteína microbiana. Houve queda linear (p 0,05 a concentração de amônia no rúmen. O cloreto de amônio pode ser utilizado como fonte de NNP para bovinos em níveis de até 1,4% da matéria seca total da dieta.Five Holstein steers weighting 450 kg were used in a 5 x 5 Latin square statistical design, where treatments consisted of five replacement levels: 0, 25, 50, 75 and 100% of urea by ammonium chloride, as non-protein nitrogen in the diet. There was a linear decrease (p 0.05 daily excretion of allantoin, purine derivatives, absorbed purines, as well as microbial nitrogen compounds and microbial efficiency synthesis. Rumen pH and plasma urea nitrogen decreased linearly (p 0.05 ruminal ammonia concentration as urea was replaced by ammonium chloride. Ammonium chloride can be used as a non-protein nitrogen source in ruminant diets up to level of 1.4% of diet dry matter.

  19. Balanço de compostos nitrogenados e produção de proteína microbiana em novilhas leiteiras alimentadas com palma forrageira, bagaço de cana-de-açúcar e uréia associados a diferentes suplementos Nitrogenous compounds balance and microbial protein production in crossbred heifers fed forage cactus, sugar cane bagasse and urea associated to different supplements

    Directory of Open Access Journals (Sweden)

    Ricardo Alexandre Silva Pessoa

    2009-05-01

    Full Text Available Objetivou-se avaliar o efeito da associação de palma forrageira ao bagaço de cana-de-açúcar e à uréia sobre o balanço de compostos nitrogenados e a produção de proteína microbiana em novilhas leiteiras recebendo ou não suplemento. Foram utilizadas 25 novilhas da raça Girolando, com peso vivo médio inicial de 227 kg, confinadas, distribuídas em delineamento experimental de blocos ao acaso, estabelecidos de acordo com o peso dos animais. A ração controle (sem suplemento foi composta de 64,0% de palma forrageira, 30,0% de bagaço de cana-de-açúcar, 4,0% de mistura uréia:sulfato de amônio (9:1 e 2,0% de mistura mineral, com base na matéria seca (MS, e as rações experimentais, de 57,0% de palma forrageira, 26,0% de bagaço de cana-de-açúcar, 3,5% de mistura uréia:sulfato de amônio, 1,8% de mistura mineral e 11,7% de suplemento (0,5% do PV dos animais. Os suplementos testados foram: farelo de trigo, farelo de soja, farelo de algodão ou caroço de algodão. O balanço de nitrogênio não foi influenciado pelas dietas e apresentou valor médio de 49,3 g/dia. A suplementação com farelo de algodão ou com farelo de soja aumentou a excreção de nitrogênio na urina, a concentração de uréia e nitrogênio uréico no plasma e a excreção urinária de uréia e nitrogênio uréico. A associação da palma forrageira ao bagaço de cana-de-açúcar e à uréia, sem o uso de suplementos, permite eficiência de síntese microbiana de 105 gPBmic/kg de NDT consumido. A suplementação com caroço de algodão proporciona maior excreção urinária de alantoína e derivados de purina e melhor eficiência de síntese microbiana, portanto, é a mais indicada nestas condições.The objective of this work was to evaluate the effect of association of forage cactus to sugar cane bagasse and urea on nitrogenous compounds balance and microbial protein synthesis in milk heifers supplemented or not. Twenty-five Holstein-Gir crossbred heifers

  20. Effects of low-pressure nitrogen plasma treatment on the surface properties and electrochemical performance of the polyethylene separator used lithium-ion batteries

    Science.gov (United States)

    Li, Chun; Li, Hsiao-Ling; Li, Chi-Heng; Liu, Yu-Shuan; Sung, Yu-Ching; Huang, Chun

    2018-01-01

    In this paper, we describe the surface transition of the polyethylene (PE) separator used in lithium-ion batteries treated by low-pressure nitrogen plasma discharge. The nitrogen-plasma-treated PE separator was characterized by contact angle measurement, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The electrochemical performance of the lithium ion batteries fabricated with the nitrogen-plasma-treated separator was also evaluated. Results showed that polar functionalization groups were induced on the PE surface by the nitrogen plasma discharge, causing the surface to become hydrophilic. The increases in surface wettability and surface free energy result in electrolyte retention improvement. Moreover, the nitrogen plasma-treated PE separator leads to superior performance in lithium-ion battery assembly.

  1. Efficacy of β-mannanase supplementation to corn-soya bean meal-based diets on growth performance, nutrient digestibility, blood urea nitrogen, faecal coliform and lactic acid bacteria and faecal noxious gas emission in growing pigs.

    Science.gov (United States)

    Upadhaya, Santi Devi; Park, Jae Won; Lee, Jae Hwan; Kim, In Ho

    2016-01-01

    A study was conducted to determine the efficacy of β-mannanase supplementation to a diet based on corn and soya bean meal (SBM) on growth performance, nutrient digestibility, blood urea nitrogen (BUN), faecal coliforms and lactic acid bacteria, and noxious gas emission in growing pigs. A total of 140 pigs [(Landrace × Yorkshire) × Duroc; average body weight 25 ± 3 kg] were randomly allotted to a 2 × 2 factorial arrangement with dietary treatments consisting of hulled or dehulled SBM without or with supplementation of 400 U β-mannanase/kg. During the 6 weeks of experimental feeding, β-mannanase supplementation had no effect on body weight gain, feed intake and gain:feed (G:F) ratio. Compared with dehulled SBM, feeding hulled SBM caused an increased feed intake of pigs in the entire trial (p = 0.05). The G:F ratio was improved in pigs receiving dehulled SBM (p < 0.05). Dietary treatments did not influence the total tract digestibility of dry matter, nitrogen and gross energy. Enzyme supplementation reduced (p < 0.05) the population of faecal coliforms and tended to reduce the NH3 concentration after 24 h of fermentation in a closed box containing faecal slurry. Feeding hulled SBM tended to reduce NH3 emission on days 3 and 5 of fermentation. In conclusion, mannanase supplementation had no influence on growth performance and nutrient digestibility but showed a positive effect on reducing coliform population and tended to reduce NH3 emission. Dehulled SBM increased G:F ratio and hulled SBM tended to reduce NH3 emission.

  2. Comparison of amino acid oxidation and urea metabolism in haemodialysis patients during fasting and meal intake

    NARCIS (Netherlands)

    Veeneman, JM; Kingma, HA; Stellaard, F; de Jong, PE; Reijngoud, DJ; Huisman, RM

    Background. The PNA (protein equivalent of nitrogen appearance) is used to calculate protein intake from urea kinetics. One of the essential assumptions in the calculation of PNA is that urea accumulation in haemodialysis (HD) patients is equivalent to amino acid oxidation. However, urea is

  3. Spectroscopic properties of nitrogen doped hydrogenated amorphous carbon films grown by radio frequency plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Hayashi, Y.; Yu, G.; Rahman, M. M.; Krishna, K. M.; Soga, T.; Jimbo, T.; Umeno, M.

    2001-01-01

    Nitrogen doped hydrogenated amorphous carbon thin films have been deposited by rf plasma-enhanced chemical vapor deposition using CH 4 as the source of carbon and with different nitrogen flow rates (N 2 /CH 4 gas ratios between 0 and 3), at 300 K. The dependence modifications of the optical and the structural properties on nitrogen incorporation were investigated using different spectroscopic techniques, such as, Raman spectroscopy, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, ultraviolet-visible (UV-VIS) spectroscopy, electron spin resonance (ESR), photoluminescence (PL) and spectroscopic ellipsometry (SE). Raman spectroscopy and IR absorption reveal an increase in sp 2 -bonded carbon or a change in sp 2 domain size with increasing nitrogen flow rate. It is found that the configuration of nitrogen atoms incorporated into an amorphous carbon network gradually changes from nitrogen atoms surrounded by three (σ bonded) to two (π bonded) neighboring carbons with increasing nitrogen flow rate. Tauc optical gap is reduced from 2.6 to 2.0 eV, and the ESR spin density and the peak-to-peak linewidth increase sharply with increasing nitrogen flow rate. Excellent agreement has been found between the measured SE data and modeled spectra, in which an empirical dielectric function of amorphous materials and a linear void distribution along the thickness have been assumed. The influence of nitrogen on the electronic density of states is explained based on the optical properties measured by UV-VIS and PL including nitrogen lone pair band. [copyright] 2001 American Institute of Physics

  4. In vivo urea cycle flux distinguishes and correlates with phenotypic severity in disorders of the urea cycle

    Science.gov (United States)

    Lee, Brendan; Yu, Hong; Jahoor, Farook; O'Brien, William; Beaudet, Arthur L.; Reeds, Peter

    2000-01-01

    Urea cycle disorders are a group of inborn errors of hepatic metabolism that result in often life-threatening hyperammonemia and hyperglutaminemia. Clinical and laboratory diagnosis of partial deficiencies during asymptomatic periods is difficult, and correlation of phenotypic severity with either genotype and/or in vitro enzyme activity is often imprecise. We hypothesized that stable isotopically determined in vivo rates of total body urea synthesis and urea cycle-specific nitrogen flux would correlate with both phenotypic severity and carrier status in patients with a variety of different enzymatic deficiencies of the urea cycle. We studied control subjects, patients, and their relatives with different enzymatic deficiencies affecting the urea cycle while consuming a low protein diet. On a separate occasion the subjects either received a higher protein intake or were treated with an alternative route medication sodium phenylacetate/benzoate (Ucephan), or oral arginine supplementation. Total urea synthesis from all nitrogen sources was determined from [18O]urea labeling, and the utilization of peripheral nitrogen was estimated from the relative isotopic enrichments of [15N]urea and [15N]glutamine during i.v. co-infusions of [5-(amide)15N]glutamine and [18O]urea. The ratio of the isotopic enrichments of 15N-urea/15N-glutamine distinguished normal control subjects (ratio = 0.42 ± 0.06) from urea cycle patients with late (0.17 ± 0.03) and neonatal (0.003 ± 0.007) presentations irrespective of enzymatic deficiency. This index of urea cycle activity also distinguished asymptomatic heterozygous carriers of argininosuccinate synthetase deficiency (0.22 ± 0.03), argininosuccinate lyase deficiency (0.35 ± 0.11), and partial ornithine transcarbamylase deficiency (0.26 ± 0.06) from normal controls. Administration of Ucephan lowered, and arginine increased, urea synthesis to the degree predicted from their respective rates of metabolism. The 15N-urea/15N-glutamine ratio

  5. Time-resolved investigation of the surface chemical modification of poly(ethylene naphthalate) by nitrogen plasma treatment

    International Nuclear Information System (INIS)

    Grace, J.M.; Zhuang, H.K.; Gerenser, L.J.; Freeman, D.R.

    2003-01-01

    A low rf nitrogen plasma source was used to treat poly(ethylene-2, 6-naphthalate) web material. Nitrogen uptake, the N 1s centroid, the N 1s peak width, rearrangement of the ester (from the O 1s spectrum), and oxygen level were measured using x-ray photoelectron spectroscopy as a function of treatment time at several treatment conditions. The observed changes in surface chemistry with treatment time are roughly consistent with a dose response having a linear regime at low doses and a saturation regime at high doses (where dose is power/width/web speed). Hence, to a first approximation, the flux densities (to the web) of relevant species scale with power. As the dose increases, the distribution of nitrogen groups formed broadens and shifts toward higher N 1s binding energy, suggesting that a larger fraction of the nitrogen-containing species are amines at low doses and amides at higher doses. The breadth of the distribution of nitrogen-containing species appears to be strongly correlated with the amount of nitrogen incorporated in the PEN surface. A surface sites model was applied to the measured nitrogen uptake as a function of treatment time. Phenomenological nitrogen incorporation and loss terms were determined in the context of this model. Both terms increase with treatment power and treatment pressure. The ratio, however, varies to a much smaller degree as a function of process conditions, with high powers and pressures giving the highest ratio. Further elucidation of the incorporation and loss processes should be possible with plasma diagnostic data related to species concentrations

  6. Urea metabolism in Barbari kids d on urea molasses diets

    International Nuclear Information System (INIS)

    Lal, M.; Singh, U.B.; Verma, D.N.; Ranjhan, S.K.

    1974-01-01

    The entry rates of urea into the body pool of urea were estimated in Barbari kids using a single injection isotope dilution technique using 14 C-urea. The excretion rates of urea were calculated by estimating total urine output over 24 h and urea content. (M.G.B.)

  7. Minimal sampling protocol for accurate estimation of urea production: a study with oral [13C]urea in fed and fasted piglets

    NARCIS (Netherlands)

    Oosterveld, Michiel J. S.; Gemke, Reinoud J. B. J.; Dainty, Jack R.; Kulik, Willem; Jakobs, Cornelis; de Meer, Kees

    2005-01-01

    An oral [13C]urea protocol may provide a simple method for measurement of urea production. The validity of single pool calculations in relation to a reduced sampling protocol was assessed. In eight fed and five fasted piglets, plasma urea enrichments from a 10 h sampling protocol were measured

  8. Excretory nitrogen metabolism in the juvenile axolotl Ambystoma mexicanum: differences in aquatic and terrestrial environments.

    Science.gov (United States)

    Loong, Ai M; Chew, Shit F; Ip, Yuen K

    2002-01-01

    The fully grown but nonmetamorphosed (juvenile) axolotl Ambystoma mexicanum was ureogenic and primarily ureotelic in water. A complete ornithine-urea cycle (OUC) was present in the liver. Aerial exposure impeded urea (but not ammonia) excretion, leading to a decrease in the percentage of nitrogen excreted as urea in the first 24 h. However, urea and not ammonia accumulated in the muscle, liver, and plasma during aerial exposure. By 48 h, the rate of urea excretion recovered fully, probably due to the greater urea concentration gradient in the kidney. It is generally accepted that an increase in carbamoyl phosphate synthetase activity is especially critical in the developmental transition from ammonotelism to ureotelism in the amphibian. Results from this study indicate that such a transition in A. mexicanum would have occurred before migration to land. Aerial exposure for 72 h exhibited no significant effect on carbamoyl phosphate synthetase-I activity or that of other OUC enzymes (with the exception of ornithine transcarbamoylase) from the liver of the juvenile A. mexicanum. This supports our hypothesis that the capacities of OUC enzymes present in the liver of the aquatic juvenile axolotl were adequate to prepare it for its invasion of the terrestrial environment. The high OUC capacity was further supported by the capability of the juvenile A. mexicanum to survive in 10 mM NH(4)Cl without accumulating amino acids in its body. The majority of the accumulating endogenous and exogenous ammonia was detoxified to urea, which led to a greater than twofold increase in urea levels in the muscle, liver, and plasma and a significant increase in urea excretion by hour 96. Hence, it can be concluded that the juvenile axolotl acquired ureotelism while submerged in water, and its hepatic capacity of urea synthesis was more than adequate to handle the toxicity of endogenous ammonia during migration to land.

  9. Using {sup 15}N to study the effect of additament on N balance of urea

    Energy Technology Data Exchange (ETDEWEB)

    Jiarong, Pan; Xianfang, Wen; Baojun, Liu; Xingyun, Zheng [Institute for Application of Atomic Energy, Chinese Academy of Agricultural Sciences, Beijing (China)

    1994-08-01

    It was showed that the dry weight and grain yield of rice were 2.3%{approx}12.7% and 1.6%{approx}11.8% higher respectively than those of urea applied alone when urea applied with cow slurry, rare-earth, Maifanshi, calcium chloride and dicyandiamine (DCD). Among the treatments, DCD and Maifanshi increased the nitrogen use efficiency of urea from 4.3 kg grain/kg N applied when urea applied alone to 10.7 kg grain and 12.5 kg grain per kg N applied. It was shown from {sup 15}N tracing experiment that the nitrogen uptake efficiency of urea for rice when applied alone was 20.6% while 25.9, 26.3, 24.0, 28.3 and 27.9% respectively when applied with cow slurry, rare-earth, maifanshi, calcium chloride and DCD. Application of urea with above various materials contributed to a apparent effect on increase of nitrogen residue in soil and nitrogen loss (particularly in loss by air) from urea, among which , the best effect was obtained on nitrogen residue in soil from urea when applied with cow slurry and rare-earth, the residues were 30.3% and 27.3% of applied nitrogen respectively, and DCD could decrease the nitrogen loss greatly, from 57.5% of applied nitrogen when applied alone to 36.3% of applied nitrogen. It was also showed that the difference of effect on kinetics of soil available nitrogen between one treatment and another was not significant, but significant difference existed in effect of different treatments on loss of soil nitrogen and soil nitrogen mineralization. Compared with labelled urea applied alone, application with cow slurry and DCD resulted in great decrease in loss of soil nitrogen and soil nitrogen mineralization while not apparent effect for application with rare-earth, calcium chloride and Maifanshi. (7 tabs.).

  10. Using 15N to study the effect of additament on N balance of urea

    International Nuclear Information System (INIS)

    Pan Jiarong; Wen Xianfang; Liu Baojun; Zheng Xingyun

    1994-08-01

    It was showed that the dry weight and grain yield of rice were 2.3%∼12.7% and 1.6%∼11.8% higher respectively than those of urea applied alone when urea applied with cow slurry, rare-earth, Maifanshi, calcium chloride and dicyandiamine (DCD). Among the treatments, DCD and Maifanshi increased the nitrogen use efficiency of urea from 4.3 kg grain/kg N applied when urea applied alone to 10.7 kg grain and 12.5 kg grain per kg N applied. It was shown from 15 N tracing experiment that the nitrogen uptake efficiency of urea for rice when applied alone was 20.6% while 25.9, 26.3, 24.0, 28.3 and 27.9% respectively when applied with cow slurry, rare-earth, maifanshi, calcium chloride and DCD. Application of urea with above various materials contributed to a apparent effect on increase of nitrogen residue in soil and nitrogen loss (particularly in loss by air) from urea, among which , the best effect was obtained on nitrogen residue in soil from urea when applied with cow slurry and rare-earth, the residues were 30.3% and 27.3% of applied nitrogen respectively, and DCD could decrease the nitrogen loss greatly, from 57.5% of applied nitrogen when applied alone to 36.3% of applied nitrogen. It was also showed that the difference of effect on kinetics of soil available nitrogen between one treatment and another was not significant, but significant difference existed in effect of different treatments on loss of soil nitrogen and soil nitrogen mineralization. Compared with labelled urea applied alone, application with cow slurry and DCD resulted in great decrease in loss of soil nitrogen and soil nitrogen mineralization while not apparent effect for application with rare-earth, calcium chloride and Maifanshi. (7 tabs.)

  11. Effects of high-volume plasmapheresis on ammonia, urea, and amino acids in patients with acute liver failure.

    Science.gov (United States)

    Clemmesen, J O; Kondrup, J; Nielsen, L B; Larsen, F S; Ott, P

    2001-04-01

    In acute liver failure (ALF), urea production is severely impaired, and detoxification of ammonia by glutamine synthesis plays an important protective role. The aim of this study was to examine the effects of therapeutic high-volume plasmapheresis (HVP) on arterial concentrations and splanchnic exchange rates of ammonia, urea, and amino acids-in particular, glutamine. A quantity of 8 L of plasma was exchanged over the course of 7 h in 11 patients with ALF after development of hepatic encephalopathy grade III-IV. Splanchnic exchange rates of ammonia, urea, and amino acids were measured by use of liver vein catheterization. HVP removed ammonia and glutamine at a rate of 1 micromol/min and 27 micromol/min, respectively. Arterial ammonia decreased from 160 +/- 65 to 114 +/- 50 micromol/L (p HVP) were as follows: for ammonia, -93 +/- 101 versus -70 +/- 80 micromol/min (NS); urea-nitrogen, 0.08 +/- 1.64 versus -0.31 +/- 0.45 mmol/min (NS); alanine, -73 +/- 151 versus 12 +/- 83 micromol/min (p HVP in patients with ALF. The data suggest that this effect of HVP could be explained by increased hepatic urea synthesis and possibly by increased glutamine synthesis in muscle tissue.

  12. Studies investigating the excretion of acetyl urea in the milk of dairy cows receiving oral doses of 14C acetyl urea

    International Nuclear Information System (INIS)

    Bergner, H.; Kijora, C.; Goersch, R.

    1976-01-01

    2 experimental cows were fed acetyl urea several weeks before the trial was started. The first cow received a daily amount of 200 g and the second cow 855 g. On the first day of experiment both cows were given 5 mCi of 14 C acetyl urea intraruminally. Up to 6 hrs after the beginning of the experiment acetyl urea in blood plasma was shown to contain a higher proportion of 14 C activity than urea. 0.21 g urea and 0.18 g acetyl urea were contained in 1 kg of milk from cow No 1 while 1 kg of milk from cow No 2 contained 0.18 g urea and 0.12 g acetyl urea. The feeding of acetyl urea to dairy cows is not recommended on the basis of the fact that any further contamination of human nutrition with foreign substances should be possibly avoided. (author)

  13. Studies investigating the excretion of acetyl urea in the milk of dairy cows receiving oral doses of /sup 14/C acetyl urea

    Energy Technology Data Exchange (ETDEWEB)

    Bergner, H; Kijora, C; Goersch, R [Humboldt-Universitaet, Berlin (German Democratic Republic). Sektion Tierproduktion und Veterinaermedizin

    1976-01-01

    2 experimental cows were fed acetyl urea several weeks before the trial was started. The first cow received a daily amount of 200 g and the second cow 855 g. On the first day of experiment both cows were given 5 mCi of /sup 14/C acetyl urea intraruminally. Up to 6 hrs after the beginning of the experiment acetyl urea in blood plasma was shown to contain a higher proportion of /sup 14/C activity than urea. 0.21 g urea and 0.18 g acetyl urea were contained in 1 kg of milk from cow No 1 while 1 kg of milk from cow No 2 contained 0.18 g urea and 0.12 g acetyl urea. The feeding of acetyl urea to dairy cows is not recommended on the basis of the fact that any further contamination of human nutrition with foreign substances should be possibly avoided.

  14. A forma de aplicação da uréia e dos resíduos vegetais afeta a disponibilidade de nitrogênio The addition form of crop residues and urea interfers on nitrogen availability

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Ernani

    2005-04-01

    Full Text Available O método de aplicação dos resíduos vegetais e dos fertilizantes nitrogenados pode afetar as reações do nitrogênio no solo, principalmente no plantio direto. O presente trabalho objetivou avaliar esses efeitos na disponibilidade de N para o milho em dois solos, em casa-de-vegetação. Combinações de métodos (ausência, incorporada ou na superfície de adição de palha de aveia (0,4kg m-2 e uréia (50mg N kg-1 foram aplicadas em unidades experimentais (7dm³ vaso-1 de dois solos, perfazendo um fatorial 3 x 3 x 2. O milho foi semeado no dia da aplicação dos tratamentos e as plantas foram cultivadas durante trinta dias, sobre um Neossolo e um Nitossolo, respectivamente com 50 e 520g kg-1 de argila e 8 e 48g kg-1 de matéria orgânica. A aplicação de palha de aveia, principalmente sobre a superfície do solo, beneficiou o desenvolvimento das plantas, possivelmente pela manutenção de maior quantidade de umidade nos solos. A aplicação de uréia não afetou nenhum parâmetro vegetal no solo argiloso, talvez porque a decomposição da matéria orgânica liberou mais N do que a imobilização ocasionada durante a decomposição da palha; no solo arenoso, entretanto, a uréia foi benéfica quando incorporada ao solo, e prejudicial quando adicionada na superfície, provavelmente devido à toxidez de amônia. Dessa forma, o efeito da decomposição da palha de aveia na disponibilidade de N foi função do teor de matéria orgânica original do solo.Management of both crop residues and nitrogen fertilizers affects soil N reactions especially on no-till systems. The magnitude of these effects on N availability to maize was evaluated in a greenhouse study. Combinations of oat straw and urea (absence, soil incorporated or surface applied were added to experimental units (7-dm³ per pot of two soils, in a 3 x 3 x 2 factorial combination. Plants were sown just following treatments addition, and grown for thirty days in two soils (Typic

  15. Effect of nitrogen plasma treatment at the Al2O3/Fe interface in magnetic tunnel junction

    International Nuclear Information System (INIS)

    Shim, Heejae; Cho, B. K.; Kim, Jin-Tae; Kim, T. W.; Park, W. J.

    2003-01-01

    We investigated the effects of nitrogen plasma treatment on top surface of Fe pinned layer for short times (t ex =0, 10, 30, and 60 s) in magnetic tunnel junctions and annealing of the junctions. The nitrogen-treated junctions show much reduced magnetoresistance (MR) ratio and significantly lower resistance-area (RA) products compared with the untreated junction, i.e., MR≅3%, RA≅30 kΩ μm 2 for t ex =10 s and MR≅10%, RA≅60 kΩ μm 2 for t ex =0 s. The untreated junction showed enhanced MR ratio up to about 17% and higher RA (≅70 kΩ μm2) upon thermal annealing at T a =230 deg. C, as expected. For the nitrogen-treated junctions, while the MR ratio also increases up to about 16% upon annealing at T a =230 deg. C, which is almost the same value as the one of the optimal reference junction, the RA values of the annealed junctions still keep as low as their initial values. We believe that the redistribution of nitrogen during the annealing process is responsible for the change of properties of nitrogen-treated junction. The bias dependence of MR and the estimation of effective barrier height and thickness are studied and found to be consistent with the observed changes in nitrogen-treated junctions

  16. Urea recycling in ruminants

    International Nuclear Information System (INIS)

    Ohara, Yoshiaki; Niibayashi, Tsunekazu

    1980-01-01

    The transfer of blood urea into the alimentary tract of goats, as ruminants, was studied by the use of 15 N-urea, 15 N-ammonium chloride and physiological experimental techniques. Blood urea after an intravenous injection of 15 N-urea appeared in the first rumen via two routes, the saliva (approximately 60% of the serum urea concentration) and idrect diffusion from the wall of the first rumen, both as the ammonium-form N. The serum urea levels from diets containing different protein levels were paralleled with the protein levels, the ammonium level in the first rumen being similar to that of the serum urea. The transfer of low protein into the NH 3 pool of the first rumen was 56% of the total NH 3 in the entire alimentary tract, and the quantitative ratio of salivary secretion of diffusion in the first rumen was 1:9. The transfer of high protein was 14% in the entire alimentary tract, and the ratio of saliva to diffusion in the first rumen was 6:1. Thus, when protein uptake was large, salivary secretion was the primary route to the first rumen. Approximately 50% of the entire quantity of blood urea in the alimentary tract appeared in the first rumen, and 35%, in the lower alimentary tract, primarily in the duodenum and jejunum. (Chiba, N.)

  17. Phenylbutyrate reduces plasma leucine concentrations without affecting the flux of leucine

    Science.gov (United States)

    Phenylbutyrate (PB) has been used as an alternative pathway to excrete nitrogen in urea cycle disorder patients for the last 20 years. PB, after oxidation to phenylacetate, is conjugated with glutamine and excreted in the urine. A reduction in the plasma concentration of branched amino acids (BCAA) ...

  18. Moderate plasma treatment enhances the quality of optically detected magnetic resonance signals of nitrogen-vacancy centres in nanodiamonds

    Science.gov (United States)

    Sotoma, Shingo; Igarashi, Ryuji; Shirakawa, Masahiro

    2016-05-01

    We demonstrate that a moderate plasma treatment increases the quality of optically detected magnetic resonance (ODMR) signals from negatively charged nitrogen-vacancy centres in nanodiamonds (NDs). We measured the statistics of the ODMR spectra of 50-nm-size NDs before and after plasma treatment. We then evaluated each ODMR spectrum in terms of fluorescence and ODMR intensities, line width and signal-to-noise (SN) ratio. Our results showed that plasma treatment for more than 10 min contributes to higher-quality ODMR signals, i.e. signals that are brighter, stronger, sharper and have a higher SN ratio. We showed that such signal improvement is due to alteration of the surface chemical states of the NDs by the plasma treatment. Our study contributes to the advancement of biosensing applications using ODMR of NDs.

  19. Application of nitrogen plasma immersion ion implantation to titanium nasal implants with nanonetwork surface structure

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ying-Sui; Yang, Wei-En [Department of Dentistry, National Yang-Ming University, Taipei 112, Taiwan (China); Zhang, Lan [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Zhu, Hongqin [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Lan, Ming-Ying [Division of Rhinology, Department of Otolaryngology Head and Neck Surgery, Taipei Veterans General Hospital, Taipei 112, Taiwan and School of Medicine, National Yang-Ming University, Taipei 112, Taiwan (China); Lee, Sheng-Wei [Institute of Materials Science and Engineering, National Central University, Taoyuan 320, Taiwan (China); Huang, Her-Hsiung, E-mail: hhhuang@ym.edu.tw [Department of Dentistry, National Yang-Ming University, Taipei 112, Taiwan (China); Institute of Oral Biology, National Yang-Ming University, Taipei 112, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung 404, Taiwan (China); Department of Medical Research, China Medical University Hospital, Taichung 407, Taiwan (China); Department of Bioinformatics and Medical Engineering, Asia University, Taichung 413, Taiwan (China); Department of Stomatology, Taipei Veterans General Hospital, Taipei 112, Taiwan (China)

    2016-07-15

    In nasal reconstruction, the response of cells to titanium (Ti) implants is mainly determined by surface features of the implant. In a pilot study, the authors applied electrochemical anodization to Ti surfaces in an alkaline solution to create a network of nanoscale surface structures. This nanonetwork was intended to enhance the responses of primary human nasal epithelial cell (HNEpC) to the Ti surface. In this study, the authors then treated the anodized, nanonetwork-structured Ti surface using nitrogen plasma immersion ion implantation (NPIII) in order to further improve the HNEpC response to the Ti surface. Subsequently, surface characterization was performed to elucidate morphology, roughness, wettability, and chemistry of specimens. Cytotoxicity, blood, and HNEpC responses were also evaluated. Our results demonstrate that NPIII treatment led to the formation of a noncytotoxic TiN-containing thin film (thickness <100 nm) on the electrochemically anodized Ti surface with a nanonetwork-structure. NPIII treatment was shown to improve blood clotting and the adhesion of platelets to the anodized Ti surface as well as the adhesion and proliferation of hNEpC. This research spreads our understanding of the fact that a TiN-containing thin film, produced using NPIII treatment, could be used to improve blood and HNEpC responses to anodized, nanonetwork-structured Ti surfaces in nasal implant applications.

  20. Phenylbutyrate improves nitrogen disposal via alternative pathway without eliciting an increase in protein breakdown and catabolism in control and ornithine transcarbamylace-deficient patients

    Science.gov (United States)

    Phenylbutyrate (PB) is a drug used in urea cycle disorder patients to elicit alternative pathways for nitrogen disposal. However, PB decreases plasma branched chain amino acid (BCAA) concentrations and prior research suggests that PB may increase leucine oxidation, indicating increased protein degra...

  1. Raising the Corrosion Resistance of Low-Carbon Steels by Electrolytic-Plasma Saturation with Nitrogen and Carbon

    Science.gov (United States)

    Kusmanov, S. A.; Grishina, E. P.; Belkin, P. N.; Kusmanova, Yu. V.; Kudryakova, N. O.

    2017-05-01

    Structural features of the external oxide layer and internal nitrided, carbonitrided and carburized layers in steels 10, 20 and St3 produced by the method of electrolytic plasma treatment are studied. Specimens of the steels are tested for corrosion in a naturally aerated 1-N solution of sodium chloride. The condition of the metal/sodium chloride solution interface is studied by the method of electrochemical impedance spectroscopy. It is shown that the corrosion resistance of low-carbon steels can be raised by anode electrolytic-plasma saturation with nitrogen and carbon. Recommendations are given on the choice of carbonitriding modes for structural steels.

  2. Suppression of carbon desorption from 4H-SiC by irradiating a remote nitrogen plasma at a low temperature

    Science.gov (United States)

    Shimabayashi, Masaharu; Kurihara, Kazuaki; Sasaki, Koichi

    2018-05-01

    We remotely irradiated a nitrogen plasma onto the carbon-side surface of 4H-SiC at a low temperature, and examined the effect of sample cooling on the characteristics of the nitride layer. An improved nitride layer, which had higher concentrations of carbon and silicon and a lower concentration of oxygen, was formed in the region at depths of more than 0.6–0.9 nm from the top surface. The depth of the fragile nitride layer in the top region, where no improved characteristics of the nitride layer were observed, became smaller with sample cooling. In addition, on the basis of the experimental results, we discussed the difference in the activation energy of the nitriding reaction of 4H-SiC supported by atomic nitrogen and molecular nitrogen in the metastable \\text{A}3Σ \\text{u} + state.

  3. Hydration of urea and alkylated urea derivatives

    Science.gov (United States)

    Kaatze, Udo

    2018-01-01

    Compressibility data and broadband dielectric spectra of aqueous solutions of urea and some of its alkylated derivatives have been evaluated to yield their numbers Nh of hydration water molecules per molecule of solute. Nh values in a broad range of solute concentrations are discussed and are compared to hydration numbers of other relevant molecules and organic ions. Consistent with previous results, it is found that urea differs from other solutes in its unusually small hydration number, corresponding to just one third of the estimated number of nearest neighbor molecules. This remarkable hydration behavior is explained by the large density φH of hydrogen bonding abilities offered by the urea molecule. In terms of currently discussed models of reorientational motions and allied dynamics in water and related associating liquids, the large density φH causes a relaxation time close to that of undisturbed water with most parts of water encircling the solute. Therefore only a small part of disturbed ("hydration") water is left around each urea molecule. Adding alkyl groups to the basic molecule leads to Nh values which, within the series of n-alkylurea derivatives, progressively increase with the number of methyl groups per solute. With n-butylurea, Nh from dielectric spectra, in conformity with many other organic solutes, slightly exceeds the number of nearest neighbors. Compared to such Nh values, hydration numbers from compressibility data are substantially smaller, disclosing incorrect assumptions in the formula commonly used to interpret the experimental compressibilities. Similar to other series of organic solutes, effects of isomerization have been found with alkylated urea derivatives, indicating that factors other than the predominating density φH of hydrogen bond abilities contribute also to the hydration properties.

  4. Characteristics of ion spectrum in a low energy nitrogen operated plasma focus: application to the metallic substrates thermal treatment

    International Nuclear Information System (INIS)

    Kelly, H.; Lepone, A.; Marquez, A.

    1998-01-01

    Full text: This work presents the nitrogen ion spectrum characteristics in a Plasma Focus device, determined using a Thomson spectrometer and a Faraday cup, operated in the secondary electron collective mode. It is also discussed the thermal treatment and the re coating induce by ions incident on a metallic surface (AISI 304 steel) placed in front of the coaxial gun, when the device is operated with a Ti implant at the end of the central electrode

  5. Liquid Phase Plasma Synthesis of Iron Oxide Nanoparticles on Nitrogen-Doped Activated Carbon Resulting in Nanocomposite for Supercapacitor Applications.

    Science.gov (United States)

    Lee, Heon; Lee, Won-June; Park, Young-Kwon; Ki, Seo Jin; Kim, Byung-Joo; Jung, Sang-Chul

    2018-03-25

    Iron oxide nanoparticles supported on nitrogen-doped activated carbon powder were synthesized using an innovative plasma-in-liquid method, called the liquid phase plasma (LPP) method. Nitrogen-doped carbon (NC) was prepared by a primary LPP reaction using an ammonium chloride reactant solution, and an iron oxide/NC composite (IONCC) was prepared by a secondary LPP reaction using an iron chloride reactant solution. The nitrogen component at 3.77 at. % formed uniformly over the activated carbon (AC) surface after a 1 h LPP reaction. Iron oxide nanoparticles, 40~100 nm in size, were impregnated homogeneously over the NC surface after the LPP reaction, and were identified as Fe₃O₄ by X-ray photoelectron spectroscopy and X-ray diffraction. NC and IONCCs exhibited pseudo-capacitive characteristics, and their specific capacitance and cycling stability were superior to those of bare AC. The nitrogen content on the NC surface increased the compatibility and charge transfer rate, and the composites containing iron oxide exhibited a lower equivalent series resistance.

  6. Deposition and surface characterization of nanoparticles of zinc oxide using dense plasma focus device in nitrogen atmosphere

    International Nuclear Information System (INIS)

    Malhotra, Yashi; Srivastava, M P; Roy, Savita

    2010-01-01

    Nanoparticles of zinc oxide from zinc oxide pellets in the nitrogen plasma atmosphere are deposited on n and p type silicon substrates using Dense Plasma Focus device. The hot and dense nitrogen plasma formed during the focus phase ionizes the ZnO pellet, which then move upward in a fountain like shape and gets deposited on substrates which are placed above the top of the anode. Structural and surface properties of the deposited ZnO are investigated using X-ray diffraction and Atomic force microscope (AFM). X-ray spectra shows the diffraction plane (002) of ZnO nanoparticles deposited on Si with few shots in nitrogen atmosphere. AFM investigations revealed that there are nanoparticles of size between 15-80 nm on n-Si and p-Si substrates. The deposition on n-type Si is better than the p-type Si can be seen from AFM images, this may be due to different orientation of silicon.

  7. Role of urea in the postprandial urine concentration cycle of the insectivorous bat Antrozous pallidus.

    Science.gov (United States)

    Bassett, John E

    2004-02-01

    Insectivorous bats, which feed once daily, produce maximally concentrated urine only after feeding. The role of urea as an osmolyte in this process was investigated in pallid bats (Antrozous pallidus) in the laboratory. Following a 24-h fast, plasma and urine were sampled before and 2 h after feeding in postprandial (PP) animals and before and 2 h after similar treatment without feeding in nonfed (NF) animals. Food consumption by PP animals and handling of NF animals had no effect on blood water content as measured by hematocrit and plasma oncotic pressure. Food consumption increased both plasma osmolality (P(osm)) and plasma urea (P(urea)) by as much as 15%. Food consumption also increased urine osmolality (U(osm)) and urine urea (U(urea)) by 50-100%. Feeding increased U(osm) regardless of changes in P(osm), and elevation of U(osm) resulted primarily from increased U(urea). In NF bats, P(osm) and P(urea) were unchanged, while U(osm) and U(urea) increased by as much as 25%. Again, increased U(osm) resulted primarily from increased U(urea). The PP urine concentration cycle of pallid bats resulted from increased urea excretion in response to apparent rapid urea synthesis. Bats rapidly metabolized protein and excreted urea following feeding when body water was most plentiful.

  8. Urea kinetics during sustained low-efficiency dialysis in critically ill patients requiring renal replacement therapy.

    Science.gov (United States)

    Marshall, Mark R; Golper, Thomas A; Shaver, Mary J; Alam, Muhammad G; Chatoth, Dinesh K

    2002-03-01

    Continuous renal replacement therapies have practical and theoretical advantages compared with conventional intermittent hemodialysis in hemodynamically unstable or severely catabolic patients with acute renal failure (ARF). Sustained low-efficiency dialysis (SLED) is a hybrid modality introduced July 1998 at the University of Arkansas for Medical Sciences that involves the application of a conventional hemodialysis machine with reduced dialysate and blood flow rates for 12-hour nocturnal treatments. Nine critically ill patients with ARF were studied during a single SLED treatment to determine delivered dialysis dose and the most appropriate model for the description of urea kinetics during treatment. Five patients were men, mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 28.9 and mean weight was 92.5 kg. Kt/V was determined by the reference method of direct dialysate quantification (DDQ) combined with an equilibrated postdialysis plasma water urea nitrogen (PUN) concentration and four other methods that were either blood or dialysate based, single or double pool, or model independent (whole-body kinetic method). Solute removal indices (SRIs) were determined from net urea removal and urea distribution volume supplied from DDQ (reference method) and by mass balance using variables supplied from blood-based formal variable-volume single-pool (VVSP) urea kinetic modeling. Equivalent renal urea clearances (EKRs) were calculated from urea generation rates and time-averaged concentrations for PUN based on weekly mass balance with kinetic variables supplied by either DDQ (reference method) or formal blood-based VVSP modeling. Mean Kt/V determined by the reference method was 1.40 and not significantly different when determined by formal VVSP modeling, DDQ using an immediate postdialysis PUN, or the whole-body kinetic method. Correction of single-pool Kt/V by a Daugirdas rate equation did not yield plausible results. Mean SRI and EKR by the

  9. Urea thermolysis and NOx reduction with and without SCR catalysts

    International Nuclear Information System (INIS)

    Fang, Howard L.; DaCosta, Herbert F.M.

    2003-01-01

    Urea-selective catalytic reduction (SCR) has been a leading contender for removal of nitrogen oxides (deNO x ) from diesel engine emissions. Despite its advantages, the SCR technology faces some critical detriments to its catalytic performance such as catalyst surface passivation (caused by deposit formation) and consequent stoichiometric imbalance of the urea consumption. Deposit formation deactivates catalytic performance by not only consuming part of the ammonia produced during urea decomposition but also degrading the structural and thermal properties of the catalyst surface. We have characterized the urea thermolysis with and without the urea-SCR catalyst using both spectroscopic (DRIFTS and Raman) and thermal techniques (thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC)) to identify the deposit components and their corresponding thermal properties. Urea thermolysis exhibits two decomposition stages, involving ammonia generation and consumption, respectively. The decomposition after the second stage leads to the product of melamine complexes, (HNC=NH) x (HNCO) y , that hinder catalytic performance. The presence of catalyst accompanied with a good spray of the urea solution helps to eliminate the second stage. In this work, kinetics of the direct reduction of NO x by urea is determined and the possibility of using additives to the urea solution in order to rejuvenate the catalyst surface and improve its performance will be discussed

  10. Tungsten oxide coatings deposited by plasma spray using powder and solution precursor for detection of nitrogen dioxide gas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao, E-mail: zhangc@yzu.edu.cn [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Wang, Jie [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Geng, Xin [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China)

    2016-05-25

    Increasing attention has been paid on preparation methods for resistive-type gas sensors based on semiconductor metal oxides. In this work, tungsten oxide (WO{sub 3}) coatings were prepared on alumina substrates and used as gas sensitive layers. The coatings were deposited by atmospheric plasma spray using powder, solution precursor, or a combination of both. Tungsten oxide powder through a powder port and ammonium tungstate aqueous solution through a liquid port were injected into plasma stream respectively or together to deposit WO{sub 3} coatings. Phase structures in the coatings were characterized by X-ray diffraction analyzer. The field-emission scanning electron microscopy images confirmed that the coatings were in microstructure, nanostructure or micro-nanostructure. The sensing properties of the sensors based on the coatings exposed to 1 ppm nitrogen dioxide gas were characterized in a home-made instrument. Sensing properties of the coatings were compared and discussed. The influences of gas humidity and working temperature on the sensor responses were further studied. - Highlights: • Porous gas sensitive coatings were deposited by plasma spray using powder and solution precursor. • Crystallized WO{sub 3} were obtained through hybrid plasma spray plus a pre-conditioned step. • Plasma power had an important influence on coating microstructure. • The particle size of atmospheric plasma-sprayed microstructured coating was stable. • Solution precursor plasma-sprayed WO{sub 3} coatings had nanostructure and showed good responses to 1 ppm NO{sub 2}.

  11. Utilização do nitrogênio (15N residual de coberturas de solo e da uréia pela cultura do milho Utilization of residual nitrogen (15N from cover crop and urea by corn

    Directory of Open Access Journals (Sweden)

    Edson Cabral da Silva

    2006-12-01

    study was to evaluate the use of residual nitrogen from urea, sunnhemp (Crotalaria juncea and millet (Pennisetum americanum labeled with 15N, applied to no-tillage corn in the previous growing season, in a Red Latosol of the Cerrado. The study was conducted in an experimental farm of the Sao Paulo State University (UNESP, Ilha Solteira, in Selvíria county (MS, Brazil, in different areas. The experiment had a randomized complete block design, with 15 treatments and four replications. Treatments were applied to corn crop in the 2001/02 and 2003/04 growing seasons. Theey were distributed in a 3 x 5 factorial layout, representing the combination of three cover crops: sunnhemp, millet and spontaneous vegetation (fallow and five N rates (as urea: 0, 30, 80, 130, and 180 kg ha-1 of N. After corn harvest, the two areas were fallowed in the dry season and were followed by corn crop in the 2002/03 (experiment 1 and 2003/04 (experiment 2 growing seasons, using the same fertilizer rate on all plots to distinguish the residual effect of N sources. The average use of residual N from the millet and sunnhemp residues (above-ground part by corn crop was less than 3.5 and 3 %, respectively, of the initial amount. The corn uptake of residual N from urea increased in a quadratic manner in experiment 1 and linearly in experiment Two as a response to the applied N rates, and the recover was below 3 %. The cover crop type did not affect the use of residual N of urea by corn, and vice-versa.

  12. Urea ammoniation compared to urea supplementation as a method ...

    African Journals Online (AJOL)

    Urea ammoniation compared to urea supplementation as a method of improving the nutritive value of wheat straw for sheep. S.W.P. Cloete, N.M. Kritzinger. Winter Rainfall Region, Eisenburg. The ammoniation of wheat straw by urea in a stack method was in- vestigated and compared to urea supplemented and untreated ...

  13. Modification of steel surface by plasma electrolytic saturation with nitrogen and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Kusmanov, S.A., E-mail: sakusmanov@yandex.ru; Kusmanova, Yu.V., E-mail: yulia.kusmanova@yandex.ru; Smirnov, A.A., E-mail: sciencealexsm@gmail.com; Belkin, P.N., E-mail: belkinp@yandex.ru

    2016-06-01

    The effect of the electrolyte composition with ammonia, acetone, and ammonium chloride on the structure and properties of low carbon steel was studied in anode plasma electrolytic nitrocarburising. An X-ray diffractometer, a scanning electron microscopy (SEM) and an optical microscope were used to characterize the phase composition of the modified layer and its surface morphology. Surface roughness was studied with a profilometer–profilograph. The hardness of the treated and untreated samples was measured using a microhardness tester. The sources of nitrogen and carbon are shown to be the products of evaporation and thermal decomposition of the electrolyte components. It is established that the influence of concentration of ammonia, acetone, and ammonium chloride on the size of the structural components of the hardened layer is explained by the competition of the anode dissolution, high-temperature oxidation and diffusion of the saturating component. The electrolyte composition (10–12.5% ammonium chloride, 5% acetone, 5% ammonia) and processing mode (800 °C, 5–10 min) of low carbon steels allowing to obtain the hardened surface layer up to 0.2 mm with microhardness 930 HV and with decrease in the roughness (R{sub a}) from 1.013 to 0.054 μm are proposed. The anode plasma electrolytic nitricarburising is able to decrease friction coefficient of the treated low carbon steel from 0.191 to 0.169 and wear rate from 13.5 mg to 1.0 mg. - Highlights: • Aqueous solution (12.5% NH{sub 4}Cl, 5% ammonia, 5% acetone) is proposed for PEN/C steels. • Microhardness of steel (0.2% C) is 930 HV due to PEN/C for 5–10 min at 800 °C. • Anode PEN/C of low carbon steel decreases its roughness (R{sub a}) from 1.013 to 0.054 μm. • Anode PEN/C decreases friction coefficient of low carbon steel from 0.191 to 0.169 • Anode PEN/C decreases wear loss of low carbon steel from 13.5 mg to 1.0 mg.

  14. Influência da temperatura e do tempo de armazenamento nas dosagens bioquímicas de uréia e creatinina em soro ou plasma caninos Effect of temperature and storage time on urea and creatinine dosages from canine serum or plasma

    Directory of Open Access Journals (Sweden)

    S.T. Fernandes

    2001-12-01

    Full Text Available O trabalho teve como objetivos avaliar algumas condições de estocagem de soro e de plasma com EDTA 10% utilizados para determinação dos valores de uréia e creatinina em cães, e avaliar a possibilidade de substituir o soro pelo plasma conservado com EDTA 10%. Foram realizadas 3600 análises (1800 amostras de soro e 1800 de plasma com amostras que permaneceram em temperaturas ambiente, de refrigeração e de congelamento. As análises foram realizadas imediatamente após a obtenção da amostra (tempo 0 e após 2, 6, 12, 24, 72 horas e 30 e 60 dias após a coleta do sangue. Os resultados permitiram concluir que a uréia conservou-se por mais tempo na amostra sérica refrigerada até 30 dias e a creatinina na amostra sérica congelada até 72h. O soro mostrou mais estabilidade que o plasma em todas as condições de estoque estabelecidas.Aiming to evaluating some conditions of EDTA 10% serum and plasma storage for urea and creatinine values determinations in canines as well as analyzing the possibility of serum substitution by plasma, a total of 3600 samples (1800 serum and 1800 of plasma were analyzed at room, refrigeration and freezing temperatures. Different time intervals were used in the analysis: immediately after sampling (time 0, and at 2, 6, 12, 24, and 72 hours, and 30 and 60 days after the blood collection. The data showed that urea remains conserved for more time in the refrigerated serum sample until 30 days and the creatinine in the frozen serum sample until 72 hours. Serum showed more stability than plasma in all storage conditions established.

  15. Ammonia formation and W coatings interaction with deuterium/nitrogen plasmas in the linear device GyM

    Energy Technology Data Exchange (ETDEWEB)

    Laguardia, L., E-mail: laguardia@ifp.cnr.it [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Caniello, R.; Cremona, A. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Dellasega, D. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Politecnico di Milano, Dipartimento di Energia, Milan (Italy); Dell’Era, F.; Ghezzi, F.; Gittini, G.; Granucci, G.; Mellera, V.; Minelli, D.; Pallotta, F. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Passoni, M. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Politecnico di Milano, Dipartimento di Energia, Milan (Italy); Ricci, D.; Vassallo, E. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy)

    2015-08-15

    In this work results of the first D{sub 2}/N{sub 2} experiments in GyM, a linear device able to produce plasmas of interest for the ITER divertor (n{sub e} 5 ⋅ 10{sup 10} cm{sup −3}, Te 5 eV, ion flux 3–5 ⋅ 10{sup 20} m{sup −2}s{sup −1}) are presented. Plasmas simulating a N-seeding scenario have been performed to evaluate ammonia formation and its effect on exposed W coatings. The presence of ND emission lines in the plasma can be correlated with the formation of ammonia, further directly detected and quantified by chromatography analysis of the exhaust. Four different W specimens were exposed in GyM to a plasma fluence of 8.78 ⋅ 10{sup 23} m{sup −2}. XPS analysis evidenced the formation of W{sub x}N{sub y} layers with nitrogen concentration in the range of 1–10% depending on the initial morphology and structure of the W samples. In all analyzed cases, nitrogen was bound and retained within the first 6 nm below the surface and no further diffusion of N into the bulk was observed.

  16. Experimental and theoretical study on emission spectra of a nitrogen photoionized plasma induced by intense EUV pulses

    Directory of Open Access Journals (Sweden)

    Saber Ismail

    2018-01-01

    Full Text Available Spectral lines of low-temperature nitrogen photoionized plasma were investigated. The photoionized plasma was created in the result of irradiation N2 gas using laser plasma EUV radiation pulses. The source was based on a 10J/10ns Nd:YAG (λ = 1064 nm laser system and a gas puff target. The EUV radiation pulses were collected and focused using a grazing incidence multifoil EUV collector. The emission spectra were measured in the ultraviolet and visible (UV/Vis range. It was found that the plasma emission lines in the lower region of the UV range are relativley weak. Nonetheless, a part of the spectra contains strong molecular band in the 300 - 430 nm originated from second positive and first negative systems band transitions of nitrogen. These molecular band transitions were identified using a code for study the diatomic molecules, LIFBASE. The vibrational band of Δv = 0 and ±1 transitions were significantly populated than of that with Δv = ±2 and 3 transitions. A comparison of the calculated and measured spectrum is presented. With an assumption of a local thermodynamic equilibrium (LTE, the vibrational temperature was determined from the integrated band intensities with the help of the Boltzmann plot method and compared to the temperature predicted by SPECAIR and LIFBASE simulations. A summary of the results and the variations in the vibrational temperatures was discussed.

  17. Experimental and theoretical study on emission spectra of a nitrogen photoionized plasma induced by intense EUV pulses

    Science.gov (United States)

    Saber, Ismail; Bartnik, Andrzej; Skrzeczanowski, Wojciech; Wachulak, Przemyslaw; Jarocki, Roman; Fiedorowicz, Henryk; Limpouch, Jiri

    2018-01-01

    Spectral lines of low-temperature nitrogen photoionized plasma were investigated. The photoionized plasma was created in the result of irradiation N2 gas using laser plasma EUV radiation pulses. The source was based on a 10J/10ns Nd:YAG (λ = 1064 nm) laser system and a gas puff target. The EUV radiation pulses were collected and focused using a grazing incidence multifoil EUV collector. The emission spectra were measured in the ultraviolet and visible (UV/Vis) range. It was found that the plasma emission lines in the lower region of the UV range are relativley weak. Nonetheless, a part of the spectra contains strong molecular band in the 300 - 430 nm originated from second positive and first negative systems band transitions of nitrogen. These molecular band transitions were identified using a code for study the diatomic molecules, LIFBASE. The vibrational band of Δv = 0 and ±1 transitions were significantly populated than of that with Δv = ±2 and 3 transitions. A comparison of the calculated and measured spectrum is presented. With an assumption of a local thermodynamic equilibrium (LTE), the vibrational temperature was determined from the integrated band intensities with the help of the Boltzmann plot method and compared to the temperature predicted by SPECAIR and LIFBASE simulations. A summary of the results and the variations in the vibrational temperatures was discussed.

  18. Design and operation results of nitrogen gas baking system for KSTAR plasma facing components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Tae [National Fusion Research Institute, 113 Gwahang-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Kim, Young-Jin, E-mail: k43689@nfri.re.kr [National Fusion Research Institute, 113 Gwahang-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Joung, Nam-Yong; Im, Dong-Seok; Kim, Kang-Pyo; Kim, Kyung-Min; Bang, Eun-Nam; Kim, Yaung-Soo [National Fusion Research Institute, 113 Gwahang-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Yoo, Seong-Yeon [Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of)

    2013-11-15

    Highlights: • Vacuum pressure in a vacuum vessel arrived at 7.24 × 10{sup −8} mbar. • PFC temperature was reached maximum 250 °C by gas temperature at 300 °C. • PFC inlet gas temperature was changed 5 °C per hour during rising and falling. • PFC gas balancing was made temperature difference among them below 8.3 °C. • System has a pre-cooler and a three-way valve to save operation energy. -- Abstract: A baking system for the Korea Superconducting Tokamak Advanced Research (KSTAR) plasma facing components (PFCs) is designed and operated to achieve vacuum pressure below 5 × 10{sup −7} mbar in vacuum vessel with removing impurities. The purpose of this research is to prevent the fracture of PFC because of thermal stress during baking the PFC, and to accomplish stable operation of the baking system with the minimum life cycle cost. The uniformity of PFC temperature in each sector was investigated, when the supply gas temperature was varied by 5 °C per hour using a heater and the three-way valve at the outlet of a compressor. The alternative of the pipe expansion owing to hot gas and the cage configuration of the three-way valve were also studied. During the fourth campaign of the KSTAR in 2011, nitrogen gas temperature rose up to 300 °C, PFC temperature reached at 250 °C, the temperature difference among PFCs was maintained at below 8.3 °C, and vacuum pressure of up to 7.24 × 10{sup −8} mbar was achieved inside the vacuum vessel.

  19. Nitrogen balance, plasma free amino acid concentrations and urinary orotic acid excretion during long-term fasting in cats.

    Science.gov (United States)

    Biourge, V; Groff, J M; Fisher, C; Bee, D; Morris, J G; Rogers, Q R

    1994-07-01

    The purpose of this study was to ascertain the changes in nitrogen balance, plasma free amino acid concentrations, urinary orotic acid excretion and body weight during long-term fasting in adult obese cats. Results from eight cats that fasted rather than eat an unpalatable diet are reported. After 5 to 6 wk of weight loss, six of the eight cats developed signs of hepatic lipidosis, and the livers of all cats were severely infiltrated with lipids. Cats lost (mean +/- SE) 33.2 +/- 1.4% of their pre-fasting body weight. Mean nitrogen balance (+/- SE) was -547 +/- 54 mg.d-1.kg-2/3 for the first week, and then the net nitrogen losses decreased to a plateau (-303 +/- 52 mg.d-1.kg-2/3) after 4 wk. Fasting was associated with a decrease in plasma concentration of essential amino acids. When plasma amino acid concentrations were considered individually, concentrations of alanine, methionine, taurine, citrulline, arginine and tryptophan decreased the most (> or = 50%), whereas concentrations of glutamine, glutamate and ornithine significantly increased. Orotic acid was not detected in the urine during the fast. After 1 wk of fasting, obese cats had reduced nitrogen excretion, but not to the same extent as has been shown in obese humans or obese rats. It is suggested that the availability of several amino acids may become limiting for liver protein synthesis during fasting and that these deficiencies may contribute to the development of hepatic lipidosis. Orotic acid was not linked to hepatic lipidosis caused by fasting in cats.

  20. Role of thin descending limb urea transport in renal urea handling and the urine concentrating mechanism

    Science.gov (United States)

    Lei, Tianluo; Zhou, Lei; Layton, Anita T.; Zhou, Hong; Zhao, Xuejian; Bankir, Lise

    2011-01-01

    Urea transporters UT-A2 and UT-B are expressed in epithelia of thin descending limb of Henle's loop and in descending vasa recta, respectively. To study their role and possible interaction in the context of the urine concentration mechanism, a UT-A2 and UT-B double knockout (UT-A2/B knockout) mouse model was generated by targeted deletion of the UT-A2 promoter in embryonic stem cells with UT-B gene knockout. The UT-A2/B knockout mice lacked detectable UT-A2 and UT-B transcripts and proteins and showed normal survival and growth. Daily urine output was significantly higher in UT-A2/B knockout mice than that in wild-type mice and lower than that in UT-B knockout mice. Urine osmolality in UT-A2/B knockout mice was intermediate between that in UT-B knockout and wild-type mice. The changes in urine osmolality and flow rate, plasma and urine urea concentration, as well as non-urea solute concentration after an acute urea load or chronic changes in protein intake suggested that UT-A2 plays a role in the progressive accumulation of urea in the inner medulla. These results suggest that in wild-type mice UT-A2 facilitates urea absorption by urea efflux from the thin descending limb of short loops of Henle. Moreover, UT-A2 deletion in UT-B knockout mice partially remedies the urine concentrating defect caused by UT-B deletion, by reducing urea loss from the descending limbs to the peripheral circulation; instead, urea is returned to the inner medulla through the loops of Henle and the collecting ducts. PMID:21849488

  1. Investigation of nitrogen atom production in Ar/N2 and He/N2 surface wave plasmas

    International Nuclear Information System (INIS)

    Tabbal, M.; Kazopoulo, M.; Christidis, T.; Isber, S.

    2000-01-01

    Full text: There is presently great interest in nitrogen plasmas for surface coating processes. Such as the deposition of nitride thin films and surface treatment of materials. Indeed, nitrogen plasmas have been used to nitride the surface of ferrous and non-ferrous materials in order to improve their surface properties such as resistance to corrosion and hardness. Moreover, the design and development of nitrogen atom sources could be essential for the synthesis of gallium nitride (GaN), a wide band-gap semiconductor whose properties have revolutionized the microelectronics and optoelectronics industries. Correlations have been established between the density of active species in the process, namely atomic nitrogen (N) produced by the discharge and GaN film properties. Thus, it is of fundamental importance to investigate the N-atom production mechanisms in such discharges. N-atom production has been studied in pure N 2 surface-wave plasmas (SWP), as a function of operating parameters, namely gas pressure and electrical power. These studies indicate that the increase in the gas temperature (T g ) limits the N-atom production. One possible way of enhancing the N 2 dissociation rate ([N]/[N 2 ]) in the plasma could be the use of gas mixtures such as Ar/N 2 or He/N 2 . the aim of this paper is to characterize an Ar/N 2 and He/N 2 surface-wave discharge (SWD) by optical emission spectroscopy (OES), in order to determine the optimal plasma conditions in terms of [N]/[N 2 ]. The plasma is generated by a radio frequency (40.68 MHz) wave launcher. The effect of mixing N 2 with Ar and He on the production of N-atoms in the plasma was investigated at varying experimental conditions, such as operating pressure (4.5 and 7.5 Torr), electrical power (40 to 120 W), at a total gas flow of 250 sccm. It was found that [N]/[N 2 ] increases with the partial pressure of Ar in the mixture by a factor of about 8 at 120W. Such an enhancement is reduced at lower incident powers. On the

  2. Assessment of Health Effects of Exogenous Urea: Summary and Key Findings.

    Science.gov (United States)

    Dickerson, Aisha S; Lee, Janice S; Keshava, Channa; Hotchkiss, Andrew; Persad, Amanda S

    2018-05-01

    Urea has been utilized as a reductant in diesel fuels to lower emission of nitrogen oxides, igniting interest in probable human health hazards associated with exposure to exogenous urea. Here, we summarize and update key findings on potential health effects of exogenous urea, including carcinogenicity. No definitive target organs for oral exposure were identified; however, results in animal studies suggest that the liver and kidney could be potential target organs of urea toxicity. The available human-subject literature suggests that the impact on lung function is minimal. Based on the literature on exogenous urea, we concluded that there was inadequate information to assess the carcinogenic potential of urea, or perform a quantitative assessment to derive reference values. Given the limited information on exogenous urea, additional research to address gaps for exogenous urea should include long-term cancer bioassays, two-generation reproductive toxicity studies, and mode-of-action investigations.

  3. Benefits of oxygen and nitrogen plasma treatment in Vero cell affinity to poly(lactide-co-glycolide acid

    Directory of Open Access Journals (Sweden)

    Andrea Rodrigues Esposito

    2013-01-01

    Full Text Available Cell adhesion on materials surface is critical because this phenomenon occurs before other events, as cell spreading, cell migration and cell differentiation. it is commonly accepted that the adhesion of cells on solid substrate is influenced by several substratum surface properties, such as wettability, surface charge, roughness and topography. plasma technique is a convenient method for modifying surface properties of materials without affecting physical properties. in this study, poly(lactide-co-glycolide, plga, membranes were modified by oxygen and nitrogen plasma to improve polymer hydrophilicity and verify their effect on vero cells culture. the plga membranes, which were characterized by sem and contact angle, showed increased surface rugosity and narrower contact angles. cell adhesion, cytotoxicity assay, sem and cytochemistry analysis showed that plasma treatment was beneficial to cell growth by improving cell-polymer interaction. Cell adhesion on materials surface is critical because this phenomenon occurs before other events, as cell spreading, cell migration and cell differentiation. It is commonly accepted that the adhesion of cells on solid substrate is influenced by several substratum surface properties, such as wettability, surface charge, roughness and topography. Plasma technique is a convenient method for modifying surface properties of materials without affecting physical properties. In this study, poly(lactide-co-glycolide, PLGA, membranes were modified by oxygen and nitrogen plasma to improve polymer hydrophilicity and verify their effect on Vero cells culture. The PLGA membranes, which were characterized by SEM and contact angle, showed increased surface rugosity and narrower contact angles. Cell adhesion, cytotoxicity assay, SEM and cytochemistry analysis showed that plasma treatment was beneficial to cell growth by improving cell-polymer interaction.

  4. Reverse iontophoresis of urea in health and chronic kidney disease: a potential diagnostic and monitoring tool?

    Science.gov (United States)

    Ebah, Leonard M; Read, Ian; Sayce, Andrew; Morgan, Jane; Chaloner, Christopher; Brenchley, Paul; Mitra, Sandip

    2012-01-01

    Background Patients with chronic kidney disease (CKD) need regular monitoring, usually by blood urea and creatinine measurements, needing venepuncture, frequent attendances and a healthcare professional, with significant inconvenience. Noninvasive monitoring will potentially simplify and improve monitoring. We tested the potential of transdermal reverse iontophoresis of urea in patients with CKD and healthy controls. Methods Using a MIC 2® Iontophoresis Controller, reverse iontophoresis was applied on the forearm of five healthy subjects (controls) and 18 patients with CKD for 3–5 h. Urea extracted at the cathode was measured and compared with plasma urea. Results Reverse iontophoresis at 250 μA was entirely safe for the duration. Cathodal buffer urea linearly correlated with plasma urea after 2 h (r = 0·82, P urea (y) from cathodal urea after 2 and 3 h, respectively. Cathodal urea concentration in controls was significantly lower than in patients with CKD after a minimum current application of 2 h (P urea cut-off of 30 μM gave a sensitivity of 83·3% and positive predictive value of 87% CKD. During haemodialysis, the fall in cathodal urea was able to track that of blood urea. Conclusion Reverse iontophoresis is safe, can potentially discriminate patients with CKD and healthy subjects and is able to track blood urea changes on dialysis. Further development of the technology for routine use can lead to an exciting opportunity for its use in diagnostics and monitoring. PMID:22409780

  5. Effect of sodium chloride intake on urine volume, urinary urea excretion, and milk urea concentration in lactating dairy cattle

    NARCIS (Netherlands)

    Spek, J.W.; Bannink, A.; Gort, G.; Hendriks, W.H.; Dijkstra, J.

    2012-01-01

    Milk urea nitrogen (MUN; mg of N/dL) has been shown to be related to excretion of urinary urea N (UUN; g of N/d) and total excretion of urinary N (UN; g of N/d) in dairy cows. In the present experiment, it was hypothesized that MUN and the relationship between MUN and UUN or UN is affected by urine

  6. Study of plasma characteristics in the cathode regime of a nitrogen glow discharge

    International Nuclear Information System (INIS)

    Margulis, Alvaro

    1987-01-01

    This research thesis reports the study of the cathode region, cathodic sheath and negative glow, of a nitrogen glow discharge. The author first presents general data regarding glow discharges, a description of the experimental installation, and measurements of discharge balancing. In the next part, he precisely describes spectroscopic methods, and the implementation of diagnoses from an experimental point of view as well as in terms of space resolution. Results are then presented and interpreted. Measurements concern space distributions of excited species, the determination of axial and radial concentrations of nitrogen ions, axial variations of rotational temperatures of the different species and variations of nitrogen ion vibrational temperature. The laser optogalvanic effect on the nitrogen molecular ion is resolved in time, and compared with the result of a theoretical model based on the mobility difference between the different nitrogen ions. Finally, the author compares experimental results on ion profiles along the discharge axis with results obtained with theoretical models [fr

  7. Urea transporters and sweat response to uremia.

    Science.gov (United States)

    Keller, Raymond W; Bailey, James L; Wang, Yanhua; Klein, Janet D; Sands, Jeff M

    2016-06-01

    In humans, urea is excreted in sweat, largely through the eccrine sweat gland. The urea concentration in human sweat is elevated when compared to blood urea nitrogen. The sweat urea nitrogen (UN) of patients with end-stage kidney disease (ESRD) is increased when compared with healthy humans. The ability to produce sweat is maintained in the overwhelming majority of ESRD patients. A comprehensive literature review found no reports of sweat UN neither in healthy rodents nor in rodent models of chronic kidney disease (CKD). Therefore, this study measured sweat UN concentrations in healthy and uremic rats. Uninephrectomy followed by renal artery ligation was used to remove 5/6 of renal function. Rats were then fed a high-protein diet to induce uremia. Pilocarpine was used to induce sweating. Sweat droplets were collected under oil. Sweat UN was measured with a urease assay. Serum UN was measured using a fluorescent ortho-pthalaldehyde reaction. Immunohistochemistry (IHC) was accomplished with a horseradish peroxidase and diaminobenzidine technique. Sweat UN in uremic rats was elevated greater than two times compared to healthy pair-fed controls (220 ± 17 and 91 ± 15 mmol/L, respectively). Post hoc analysis showed a significant difference between male and female uremic sweat UN (279 ± 38 and 177 ± 11 mmol/L, respectively.) IHC shows, for the first time, the presence of the urea transporters UT-B and UT-A2 in both healthy and uremic rat cutaneous structures. Future studies will use this model to elucidate how rat sweat UN and other solute excretion is altered by commonly prescribed diuretics. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  8. Tribological changes on SS304 stainless steel induced by nitrogen plasma immersion ion implantation with and without auxiliary heating

    International Nuclear Information System (INIS)

    Mello, C.B.; Ueda, M.; Lepienski, C.M.; Reuther, H.

    2009-01-01

    In order to achieve quite thick treated layers with reasonable thickness uniformity in SS304 steel, the plasma immersion ion implantation (PIII) process was run in high-temperature, up to 350 deg. C, to induce high thermal diffusion but avoid the white layer formation. In these experiments, we heated the sample-holder with a shielded resistive wire properly wound around it and subjected the SS samples to nitrogen glow discharge PIII with relatively low voltages (10 kV) in different temperatures. We also treated the SS samples by the traditional PIII method, slowly increasing the high voltage pulse intensities, until 14 kV at the end of processing, reaching temperatures of up to 350 deg. C. These modes of treatments were compared with respect to nitrogen implantation profiles, X-ray diffraction, tribology and mechanical properties. X-ray diffraction results indicated a much higher efficiency of auxiliary heated PIII mode compared to the ordinary PIII. Very prominent γ N peaks were observed for the first mode, indicating large concentration of nitrogen in thick layers, confirmed by the nitrogen profiles measured by GDOS and AES. Improved mechanical and tribological properties were obtained for SS304 samples treated by the PIII with auxiliary heating, more than for ordinary PIII. Hardness was enhanced by up to 2.77 times, as seen by nanoindentation tests.

  9. Vascular toxicity of urea, a new "old player" in the pathogenesis of chronic renal failure induced cardiovascular diseases.

    Science.gov (United States)

    Giardino, Ida; D'Apolito, Maria; Brownlee, Michael; Maffione, Angela Bruna; Colia, Anna Laura; Sacco, Michele; Ferrara, Pietro; Pettoello-Mantovani, Massimo

    2017-12-01

    Chronic kidney disease in children is an irreversible process that may lead to end-stage renal disease. The mortality rate in children with end-stage renal disease who receive dialysis increased dramatically in the last decade, and it is significantly higher compared with the general pediatric population. Furthermore, dialysis and transplant patients, who have developed end-stage renal disease during childhood, live respectively far less as compared with age/race-matched populations. Different reports show that cardiovascular disease is the leading cause of death in children with end-stage renal disease and in adults with childhood-onset chronic kidney disease, and that children with chronic kidney disease are in the highest risk group for the development of cardiovascular disease. Urea, which is generated in the liver during catabolism of amino acids and other nitrogenous metabolites, is normally excreted into the urine by the kidneys as rapidly as it is produced. When renal function is impaired, increasing concentrations of blood urea will steadily accumulate. For a long time, urea has been considered to have negligible toxicity. However, the finding that plasma urea is the only significant predictor of aortic plaque area fraction in an animal model of chronic renal failure -accelerated atherosclerosis, suggests that the high levels of urea found in chronic dialysis patients might play an important role in accelerated atherosclerosis in this group of patients. The aim of this review was to provide novel insights into the role played by urea in the pathogenesis of accelerated cardiovascular disease in renal failure.

  10. Vascular toxicity of urea, a new “old player” in the pathogenesis of chronic renal failure induced cardiovascular diseases

    Science.gov (United States)

    D’Apolito, Maria; Brownlee, Michael; Maffione, Angela Bruna; Colia, Anna Laura; Sacco, Michele; Ferrara, Pietro; Pettoello-Mantovani, Massimo

    2017-01-01

    Chronic kidney disease in children is an irreversible process that may lead to end-stage renal disease. The mortality rate in children with end-stage renal disease who receive dialysis increased dramatically in the last decade, and it is significantly higher compared with the general pediatric population. Furthermore, dialysis and transplant patients, who have developed end-stage renal disease during childhood, live respectively far less as compared with age/race-matched populations. Different reports show that cardiovascular disease is the leading cause of death in children with end-stage renal disease and in adults with childhood-onset chronic kidney disease, and that children with chronic kidney disease are in the highest risk group for the development of cardiovascular disease. Urea, which is generated in the liver during catabolism of amino acids and other nitrogenous metabolites, is normally excreted into the urine by the kidneys as rapidly as it is produced. When renal function is impaired, increasing concentrations of blood urea will steadily accumulate. For a long time, urea has been considered to have negligible toxicity. However, the finding that plasma urea is the only significant predictor of aortic plaque area fraction in an animal model of chronic renal failure -accelerated atherosclerosis, suggests that the high levels of urea found in chronic dialysis patients might play an important role in accelerated atherosclerosis in this group of patients. The aim of this review was to provide novel insights into the role played by urea in the pathogenesis of accelerated cardiovascular disease in renal failure. PMID:29483797

  11. A Revival of Waste: Atmospheric Pressure Nitrogen Plasma Jet Enhanced Jumbo Silicon/Silicon Carbide Composite in Lithium Ion Batteries.

    Science.gov (United States)

    Chen, Bing-Hong; Chuang, Shang-I; Liu, Wei-Ren; Duh, Jenq-Gong

    2015-12-30

    In this study, a jumbo silicon/silicon carbide (Si/SiC) composite (JSC), a novel anode material source, was extracted from solar power industry cutting waste and used as a material for lithium-ion batteries (LIBs), instead of manufacturing the nanolized-Si. Unlike previous methods used for preventing volume expansion and solid electrolyte interphase (SEI), the approach proposed here simply entails applying surface modification to JSC-based electrodes by using nitrogen-atmospheric pressure plasma jet (N-APPJ) treatment process. Surface organic bonds were rearranged and N-doped compounds were formed on the electrodes through applying different plasma treatment durations, and the qualitative examinations of before/after plasma treatment were identified by X-ray photoelectron spectroscopy (XPS) and electron probe microanalyzer (EPMA). The surface modification resulted in the enhancement of electrochemical performance with stable capacity retention and high Coulombic efficiency. In addition, depth profile and scanning electron microscope (SEM) images were executed to determine the existence of Li-N matrix and how the nitrogen compounds change the surface conditions of the electrodes. The N-APPJ-induced rapid surface modification is a major breakthrough for processing recycled waste that can serve as anode materials for next-generation high-performance LIBs.

  12. Experience of high-nitrogenous steel powder application in repairs and surface hardening of responsible parts for power equipment by plasma spraying

    Science.gov (United States)

    Kolpakov, A. S.; Kardonina, N. I.

    2016-02-01

    The questions of the application of novel diffusion-alloying high-nitrogenous steel powders for repair and surface hardening of responsible parts of power equipment by plasma spraying are considered. The appropriateness of the method for operative repair of equipment and increasing its service life is justified. General data on the structure, properties, and manufacture of nitrogen-, aluminum-, and chromium-containing steel powders that are economically alloyed using diffusion are described. It is noted that the nitrogen release during the decomposition of iron nitrides, when heating, protects the powder particles from oxidation in the plasma jet. It is shown that the coating retains 50% of nitrogen that is contained in the powder. Plasma spraying modes for diffusion-alloying high-nitrogenous steel powders are given. The service properties of plasma coatings based on these powders are analyzed. It is shown that the high-nitrogenous steel powders to a nitrogen content of 8.9 wt % provide the necessary wear resistance and hardness of the coating and the strength of its adhesion to the substrate and corrosion resistance to typical aggressive media. It is noted that increasing the coating porosity promotes stress relaxation and increases its thickness being limited with respect to delamination conditions in comparison with dense coatings on retention of the low defectiveness of the interface and high adhesion to the substrate. The examples of the application of high-nitrogenous steel powders in power engineering during equipment repairs by service companies and overhaul subdivisions of heat power plants are given. It is noted that the plasma spraying of diffusion-alloyed high-nitrogenous steel powders is a unique opportunity to restore nitrided steel products.

  13. Urea-N recycling in lactating dairy cows fed diets with 2 different levels of dietary crude protein and starch with or without monensin.

    Science.gov (United States)

    Recktenwald, E B; Ross, D A; Fessenden, S W; Wall, C J; Van Amburgh, M E

    2014-03-01

    Rumensin (monensin; Elanco Animal Health, Greenfield, IN) has been shown to reduce ammonia production and microbial populations in vitro; thus, it would be assumed to reduce ruminal ammonia production and subsequent urea production and consequently affect urea recycling. The objective of this experiment was to determine the effects of 2 levels of dietary crude protein (CP) and 2 levels of starch, with and without Rumensin on urea-N recycling in lactating dairy cattle. Twelve lactating Holstein dairy cows (107 ± 21 d in milk, 647 kg ± 37 kg of body weight) were fed diets characterized as having high (16.7%) or low (15.3%) CP with or without Rumensin, while dietary starch levels (23 vs. 29%) were varied between 2 feeding periods with at least 7d of adaptation between measurements. Cows assigned to high or low protein and to Rumensin or no Rumensin remained on those treatments to avoid carryover effects. The diets consisted of approximately 40% corn silage, 20% alfalfa hay, and 40% concentrate mix specific to the treatment diets, with 0.5 kg of wheat straw added to the high starch diets to enhance effective fiber intake. The diets were formulated using Cornell Net Carbohydrate and Protein System (version 6.1), and the low-protein diets were formulated to be deficient for rumen ammonia to create conditions that should enhance the demand for urea recycling. The high-protein diets were formulated to be positive for both rumen ammonia and metabolizable protein. Rumen fluid, urine, feces, and milk samples were collected before and after a 72-h continuous jugular infusion of (15)N(15)N-urea. Total urine and feces were collected during the urea infusions for N balance measurements. Milk yield and dry matter intake were improved in cows fed the higher level of dietary CP and by Rumensin. Ruminal ammonia and milk and plasma urea nitrogen concentrations corresponded to dietary CP concentration. As has been shown in vitro, Rumensin reduced rumen ammonia concentration by

  14. Effect of protein level on performance, nitrogen utilisation and carcass composition in finisher pigs

    DEFF Research Database (Denmark)

    Nørgaard, Jan Værum; Hansen, Michael Jørgen; Assadi Soumeh, Elham

    2014-01-01

    cages. Feed intake, gain and feed utilisation were not significantly affected. Plasma urea (P carcass tended to increase linearly by reducing CP, but neither nitrogen retention nor carcass meat percentage...... and back fat depth differed among treatments. In conclusion, the study indicated that CP could be decreased to 136 g/kg as-fed for growing pigs in the weight range 50–100 kg without negative impact on growth performance and carcass traits. Moreover, leanness was not affected by excess CP....

  15. Diminished renal urea excretion in the llama at reduced food intake

    International Nuclear Information System (INIS)

    Engelhardt, W.; Engelhardt, W. von

    1976-01-01

    Renal urea excretion was studied in three llamas under various feeding conditions. Glomerular filtration rate (GFR) was estimated from inulin clearance. Tubular reabsorbed urea was the difference between glomerular filtered and renal excreted urea. Plasma urea concentration increased significantly when feeding was reduced by 40% and 60%, not applicable to a straw diet. With reduced hay feeding and on a straw diet only a slight and insignificant decrease was observed in renal urea excretion, with only a 3% lowering in GFR and glomerular filtered urea. With a straw diet, the glomerular filtered urea was significantly below the controls. The fraction of filtered urea reabsorbed in the tubules was constant (36%-47%). Very high reabsorption (87%) on a supplemented straw dietwas observed in one llama which after nearly 6 months on this low protein diet - could be shown to have lost only 5% of its body weight

  16. Final report of the safety assessment of Urea.

    Science.gov (United States)

    2005-01-01

    Although Urea is officially described as a buffering agent, humectant, and skin-conditioning agent-humectant for use in cosmetic products, there is a report stating that Urea also is used in cosmetics for its desquamating and antimicrobial action. In 2001, the Food and Drug Administration (FDA) reported that Urea was used in 239 formulations. Concentrations of use for Urea ranged from 0.01% to 10%. Urea is generally recognized as safe by FDA for the following uses: side-seam cements for food contact; an inhibitor or stabilizer in pesticide formulations and formulations applied to animals; internal sizing for paper and paperboard and surface sizing and coating of paper and paper board that contact water-in-oil dairy emulsions, low-moisture fats and oils, moist bakery products, dry solids with surface containing no free fats or oil, and dry solids with the surface of fat or oil; and to facilitate fermentation of wine. Urea is the end product of mammalian protein metabolism and the chief nitrogenous compound of urine. Urea concentrations in muscle, liver, and fetuses of rats increased after a subcutaneous injection of Urea. Urea diffused readily through the placenta and into other maternal and fetal organs. The half-life of Urea injected into rabbits was on the order of several hours, and the reutilization rate was 32.2% to 88.8%. Urea given to rats by a bolus injection or continuous infusion resulted in distribution to the following brain regions: frontal lobe, caudate nucleus, hippocampus, thalamus plus hypothalamus, pons and white matter (corpus callosum). The permeability constant after treatment with Urea of whole skin and the dermis of rabbits was 2.37 +/- 0.13 (x 10(6)) and 1.20 +/- 0.09 (x10(3)) cm/min, respectively. The absorption of Urea across normal and abraded human skin was 9.5% +/- 2.3% and 67.9% +/- 5.6%, respectively. Urea increased the skin penetration of other compounds, including hydrocortisone. No toxicity was observed for Urea at levels as high

  17. Nitrogen retention and water balance in animals fed medium protein ...

    African Journals Online (AJOL)

    amount of nitrogen, in contrast to control animals that lost 2.4% nitrogen via the faeces. Inadequate drinking caused decreased excretion of urea. The improved nitrogen retention coupled with high rates of urea recycling enhances nutrients digestion and consequently the animals' absorptive capabilities. . (Afr. J. Biomed.

  18. Body fluid osmolytes and urea and ammonia flux in the colon of two chondrichthyan fishes, the ratfish, Hydrolagus colliei, and spiny dogfish, Squalus acanthias.

    Science.gov (United States)

    Anderson, W Gary; Nawata, C Michele; Wood, Chris M; Piercey-Normore, Michele D; Weihrauch, Dirk

    2012-01-01

    The present study has examined the role of the colon in regulating ammonia and urea nitrogen balance in two species of chondrichthyans, the ratfish, Hydrolagus colliei (a holocephalan) and the spiny dogfish, Squalus acanthias (an elasmobranch). Stripped colonic tissue from both the dogfish and ratfish was mounted in an Ussing chamber and in both species bi-directional urea flux was found to be negligible. Urea uptake by the mucosa and serosa of the isolated colonic epithelium through accumulation of (14)C-urea was determined to be 2.8 and 6.2 fold greater in the mucosa of the dogfish compared to the serosa of the dogfish and the mucosa of the ratfish respectively. Furthermore, there was no difference between serosal and mucosal accumulation of (14)C-urea in the ratfish. Through the addition of 2mM NH(4)Cl to the mucosal side of each preparation the potential for ammonia flux was also examined. This was again found to be negligible in both species suggesting that the colon is an extremely tight epithelium to the movement of both urea and ammonia. Plasma, chyme and bile fluid samples were also taken from the agastric ratfish and were compared with solute concentrations of equivalent body fluids in the dogfish. Finally molecular analysis revealed expression of 3 isoforms of the urea transport protein (UT) and an ammonia transport protein (Rhbg) in the gill, intestine, kidney and colon of the ratfish. Partial nucleotide sequences of the UT-1, 2 and 3 isoforms in the ratfish had 95, 95 and 92% identity to the equivalent UT isoforms recently identified in another holocephalan, the elephantfish, Callorhinchus milii. Finally, the nucleotide sequence of the Rhbg identified in the ratfish had 73% identity to the Rhbg protein recently identified in the little skate, Leucoraja erinacea. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Simultaneous determination of glucose, triglycerides, urea, cholesterol, albumin and total protein in human plasma by Fourier transform infrared spectroscopy: direct clinical biochemistry without reagents.

    Science.gov (United States)

    Jessen, Torben E; Höskuldsson, Agnar T; Bjerrum, Poul J; Verder, Henrik; Sørensen, Lars; Bratholm, Palle S; Christensen, Bo; Jensen, Lene S; Jensen, Maria A B

    2014-09-01

    Direct measurement of chemical constituents in complex biologic matrices without the use of analyte specific reagents could be a step forward toward the simplification of clinical biochemistry. Problems related to reagents such as production errors, improper handling, and lot-to-lot variations would be eliminated as well as errors occurring during assay execution. We describe and validate a reagent free method for direct measurement of six analytes in human plasma based on Fourier-transform infrared spectroscopy (FTIR). Blood plasma is analyzed without any sample preparation. FTIR spectrum of the raw plasma is recorded in a sampling cuvette specially designed for measurement of aqueous solutions. For each analyte, a mathematical calibration process is performed by a stepwise selection of wavelengths giving the optimal least-squares correlation between the measured FTIR signal and the analyte concentration measured by conventional clinical reference methods. The developed calibration algorithms are subsequently evaluated for their capability to predict the concentration of the six analytes in blinded patient samples. The correlation between the six FTIR methods and corresponding reference methods were 0.87albumin and total protein in human plasma. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  20. Living with urea stress

    Indian Academy of Sciences (India)

    Intracellular organic osmolytes are present in certain organisms adapted to harsh environments. These osmolytes protect intracellular macromolecules against denaturing environmental stress. In contrast to the usually benign effects of most organic osmolytes, the waste product urea is a well-known perturbant of ...

  1. Nitrogen uptake and fertilizer nitrogen use efficiency of wheat under different soil water conditions

    International Nuclear Information System (INIS)

    Wang Baiqun; Zhang Wei; Yu Cunzu

    1999-01-01

    The pot experiment was conducted to study the effects of soil water regime and fertilizer nitrogen rate on the yields, nitrogen uptake and fertilizer nitrogen utilization of wheat by using 15 N tracer method. The results showed that the aboveground biomass, stem yield and grain yield increased with the increase of soil moisture in the fertilizer nitrogen treatments. All the yield increased with the increase of the fertilizer nitrogen rate in the soil water treatments. It was found that both soil water regime and fertilizer nitrogen rate significantly influenced the amount of nitrogen uptake by wheat according to the variance analysis. The amount of nitrogen uptake increased with the rise of the soil moisture in fertilizer nitrogen treatments and the amount also increased with the increase of the urea nitrogen rate in the soil water regime. Soil water regimes not only had an impact on nitrogen uptake but also had a close relationship with soil nitrogen supply and fertilizer nitrogen use efficiency. The soil A values decreased in urea treatment and increased with the rise of the soil moisture in the combination treatment of urea with pig manure. The fertilizer nitrogen use efficiency rose with the rise of the soil moisture in the same fertilizer nitrogen treatment. The fertilizer nitrogen use efficiency of the urea treatment was 13.3%, 27.9% and 32.3% in the soils with 50%, 70% and 90% of the field water capacity, respectively. The fertilizer nitrogen use efficiency in the combination treatment of urea with pig manure was 20.0%, 29.9% and 34.4% in the soils of above three levels, respectively. It was concluded that the low soil moisture restricted urea nitrogen use efficiency (UNUE) and the UNUE could be raised by combination treatment of urea with manure in the soil of enough moisture

  2. Study of the effects of E × B fields as mechanism to carbon-nitrogen plasma immersion ion implantation on stainless steel samples

    Science.gov (United States)

    Pillaca, E. J. D. M.; Ueda, M.; Oliveira, R. M.; Pichon, L.

    2014-08-01

    Effects of E × B fields as mechanism to carbon-nitrogen plasma immersion ion implantation (PIII) have been investigated. This magnetic configuration when used in PIII allows obtaining high nitrogen plasma density close to the ion implantation region. Consequently, high ions dose on the target is possible to be achieved compared with standard PIII. In this scenario, nitrogen and carbon ions were implanted simultaneously on stainless steel, as measured by GDOES and detected by X-ray diffraction. Carbon-tape disposed on the sample-holder was sputtered by intense bombardment of nitrogen ions, being the source of carbon atoms in this experiment. The implantation of both N and C caused changes on sample morphology and improvement of the tribological properties of the stainless steel.

  3. Perdas de nitrogênio por volatilização de amônia com aplicação de uréia em solo de várzea com diferentes níveis de umidade Nitrogen loss by ammonia volatilization with urea application in wetland soil with different soil water status

    Directory of Open Access Journals (Sweden)

    Francisco Mendoza Duarte

    2007-06-01

    Full Text Available A primeira adubação nitrogenada em cobertura para o arroz irrigado por alagamento pode ser realizada em solo seco ou em lâmina de água, afetando a taxa de volatilização de amônia e, conseqüentemente, a eficiência da adubação nitrogenada. O objetivo deste trabalho foi avaliar as perdas de N por volatilização de amônia com a aplicação de uréia em solo de várzea com diferentes níveis de umidade. O experimento foi conduzido em casa-de-vegetação, utilizando-se vasos contendo 5kg de um Planossolo Hidromórfico que recebeu os tratamentos: N0 - testemunha sem aplicação de uréia (solo úmido; USSE - aplicação de uréia em solo seco; USUM - aplicação de uréia em solo úmido; USSA - aplicação de uréia em solo saturado; e USLA - aplicação de uréia em solo com lâmina de água. As avaliações das perdas de amônia foram realizadas com coletores tipo semi-aberto estático após 10, 24, 34, 48, 72, 96, 144, 192 e 264 horas da aplicação de uréia. Ao final das 264 horas de avaliação, as perdas de amônia foram equivalentes para os tratamentos com aplicação em solo úmido, saturado ou sob lâmina de água, sendo os maiores picos de emissão de amônia entre 34 e 48 horas para o solo úmido e o saturado e 72 horas para a lâmina de água. A aplicação de N-uréia sobre a lâmina de água não evitou as perdas de N por volatilização de amônia.The first topdressing nitrogen (N application to flooded rice can be done on dry soil or soil after ponding water, affecting ammonia volatilization rate and, consequently, nitrogen fertilization efficiency. This study was aimed at quantifing N losses by ammonia volatilization after urea application in a wetland soil with different soil water status. The experiment was carried out in a greenhouse, using 5kg pots with a Albaqualf with following treatments: N0 - control without urea application (wet soil; USSE - urea application on dry soil; USUM - urea application on wet soil; USSA

  4. Elevated phenylacetic acid levels do not correlate with adverse events in patients with urea cycle disorders or hepatic encephalopathy and can be predicted based on the plasma PAA to PAGN ratio.

    Science.gov (United States)

    Mokhtarani, M; Diaz, G A; Rhead, W; Berry, S A; Lichter-Konecki, U; Feigenbaum, A; Schulze, A; Longo, N; Bartley, J; Berquist, W; Gallagher, R; Smith, W; McCandless, S E; Harding, C; Rockey, D C; Vierling, J M; Mantry, P; Ghabril, M; Brown, R S; Dickinson, K; Moors, T; Norris, C; Coakley, D; Milikien, D A; Nagamani, S C; Lemons, C; Lee, B; Scharschmidt, B F

    2013-12-01

    Phenylacetic acid (PAA) is the active moiety in sodium phenylbutyrate (NaPBA) and glycerol phenylbutyrate (GPB, HPN-100). Both are approved for treatment of urea cycle disorders (UCDs) - rare genetic disorders characterized by hyperammonemia. PAA is conjugated with glutamine in the liver to form phenylacetyleglutamine (PAGN), which is excreted in urine. PAA plasma levels ≥ 500 μg/dL have been reported to be associated with reversible neurological adverse events (AEs) in cancer patients receiving PAA intravenously. Therefore, we have investigated the relationship between PAA levels and neurological AEs in patients treated with these PAA pro-drugs as well as approaches to identifying patients most likely to experience high PAA levels. The relationship between nervous system AEs, PAA levels and the ratio of plasma PAA to PAGN were examined in 4683 blood samples taken serially from: [1] healthy adults [2], UCD patients of ≥ 2 months of age, and [3] patients with cirrhosis and hepatic encephalopathy (HE). The plasma ratio of PAA to PAGN was analyzed with respect to its utility in identifying patients at risk of high PAA values. Only 0.2% (11) of 4683 samples exceeded 500 μg/ml. There was no relationship between neurological AEs and PAA levels in UCD or HE patients, but transient AEs including headache and nausea that correlated with PAA levels were observed in healthy adults. Irrespective of population, a curvilinear relationship was observed between PAA levels and the plasma PAA:PAGN ratio, and a ratio>2.5 (both in μg/mL) in a random blood draw identified patients at risk for PAA levels>500 μg/ml. The presence of a relationship between PAA levels and reversible AEs in healthy adults but not in UCD or HE patients may reflect intrinsic differences among the populations and/or metabolic adaptation with continued dosing. The plasma PAA:PAGN ratio is a functional measure of the rate of PAA metabolism and represents a useful dosing biomarker. © 2013.

  5. Life cycle assessment of nitrogen fixation process assisted by plasma technology and incorporating renewable energy

    NARCIS (Netherlands)

    Anastasopoulou, A.; Butala, S.D.; Lang, J.; Hessel, V.; Wang, Q.

    2016-01-01

    The importance of nitrogen fixation is evident in every aspect of a human being’s life -from the synthesis of vital for all organisms nutrients and, in turn, the ecosystem conservation to the production of fertilizers, plastics and many other daily usage products. However, increasing concerns about

  6. Nitrogen balance and ruminal assessment in male and female sheeps fed rations containing castor cake under different treatments

    Directory of Open Access Journals (Sweden)

    Rafael Nogueira Furtado

    2014-12-01

    Full Text Available Was evaluated the influence of alternative methods of detoxification of castor cake on nitrogen balance and ruminal evaluation in sheep fed isocaloric and isonitrogenous experimental diets. Twenty sheep (ten males and ten females were used in five treatments (castor cake untreated, treated with limestone, treated with urea, treated with phosphate monodicalcium and autoclaved and four repetitions. For nitrogen balance we used a randomized block design, with the blocks according to the sex and the variables pH and ammonia nitrogen (NH3-N in the experimental design was split plot, with plots in the diets subplots and the collection times (0, 2, 5 and 8 hours postprandial.The treatments did not influence N intake, N urinary, urea and N-urea concentration in plasma. The Urinary N was higher in diet containing castor cake treated with phosphate monodicalcium (FOS when compared with those containing castor cake treated by autoclave (ACL. Already the nitrogen balance (BN was higher in diet ACL when compared to FOS diet. The pH and N-NH3 were within the normal range of sheep, being little affected by diet. Diets with methods of detoxification of castor cake promoted moderate changes in nitrogen balance with emphasis on the castor cake autoclaved and treated with limestone. The males sheep showed higher nitrogen balance than females.

  7. Effects of trace of nitrogen on the helium atmospheric pressure plasma jet interacting with a dielectric substrate

    Science.gov (United States)

    Ning, Wenjun; Dai, Dong; Zhang, Yuhui; Han, Yongxia; Li, Licheng

    2018-03-01

    Experimental observations and simulation results regarding a pure He atmospheric pressure plasma jet (APPJ) and He  +  N2 APPJs interacting with a downstream dielectric substrate are presented in this paper. Experiments utilizing spatial-temporal imaging show that, in the case of the pure He APPJ, an annular plasma-substrate interaction pattern is formed. With the introduction of N2, the plasma is more uniformly distributed on the substrate surface, appearing a solid interaction pattern. The experimental measurements indicate 0.5% N2 mixture is the optimal condition to achieve the most intense discharge, while the plasma-substrate contact area is slightly reduced by 6.1% in comparison to that of the pure He APPJ. A 2D self-consistent fluid model is constructed to provide insights into the role of the addition of trace of N2 on the discharge dynamics. The discharge morphologies predicated by the model is in principle consistent with the experimental observations. The simulation reveals that the conversion from the annular plasma-substrate interaction pattern to the solid one is attributed to the synthetic effect of the addition of N2 and the presentence of the substrate acting as the cathode to enhance the local electric field. In the solid interaction pattern, the Penning ionization makes a significant contribution to the surface discharge, especially in the afterglow region. The dominant positive ions (N2+ and N4+ ) and the reactive oxygen and nitrogen species including O and N gain remarkable increment in the flux intensity to the central surface, which merits great application potential.

  8. Comparison of the behavior of fibroblast and bone marrow-derived mesenchymal stem cell on nitrogen plasma-treated gelatin films

    International Nuclear Information System (INIS)

    Prasertsung, I.; Kanokpanont, S.; Mongkolnavin, R.; Wong, C.S.; Panpranot, J.; Damrongsakkul, S.

    2013-01-01

    The attachment and growth behavior of mouse fibroblast (L929) and rat bone marrow-derived mesenchymal stem cell (MSC) on nitrogen plasma-treated and untreated gelatin films was investigated and compared. The gelatin films were prepared by solution casting (0.05% w/v) and crosslinked using dehydrothermal treatment. The crosslinked gelatin films were treated with nitrogen alternating current (AC) 50 Hz plasma systems at various treatment time. The results on the attachment and growth of two cells; L929 and MSC, on plasma-treated gelatin film showed that the number of attached and proliferated cells on plasma-treated gelatin films was significantly increased compared to untreated samples. However, no significant difference between the number of attached L929 and MSC on plasma-treated gelatin was observed. The shorter population doubling time and higher growth rate of cells cultured on plasma-treated film indicated the greater growth of cells, compared to ones on untreated films. The greatest enhancement of cell attachment and growth were noticed when the film was treated with nitrogen plasma for 9 to 15 s. This suggested that the greater attachment and growth of both cells on gelatin films resulted from the change of surface properties, i.e. hydrophilicity, surface energy, and chemistry. The suitable water contact angle and oxygen/nitrogen ratio (O/N) of gelatin film for best L929 and MSC attachment were observed at 27–32° and 1.4, respectively. These conditions also provided the best proliferation of cells on plasma-treated gelatin films. - Highlights: • We compared the attachment and growth behavior of L929 and MSC. • The attachment of two cells on plasma-treated gelatin was significantly increased. • The shorter population doubling time and higher growth rate of cells were observed. • L929 fibroblast exhibited the greater proliferation, compared to MSC

  9. Kinetics of dietary nitrogen utilization in cattle and buffaloes fed diets containing NPN salts, using15N as an isotopic tracer

    International Nuclear Information System (INIS)

    Dhiman, T.R.; Arora, S.P.

    1990-01-01

    Nitrogen kinetics was compared in cow and buffalo calves (4 groups). Groups 1 and 3 were fed basal diet supplemented with urea (test diet 1) and group 2 and 4 were fed basal diet supplemented with urea plus ammonium sulphate (test diet 2). Dietary nitrogen metabolized to ammonia in the rumen was 50, 46, 40 and 37% in groups 1 through 4 respectively. Of the total dietary nitrogen, 67-70% was apparently digested in reticulorumen, of which 27, 34, 40 and 48% was used as amino acids and peptides, and the remainder 73, 66, 60 and 52% was degraded to ammonia in groups 1 through 4 respectively. On an average, 65% of the ammonia produced was irreversibly lost and 35% was recycled. Of the ruminal ammonia produced 21% was recycled within nitrogen pools. Higher incorporation of ruminal 15 NH 3 into suspended bacterial-N was observed in test diet 2 as compared to that in test diet 1. Per cent plasma urea-N and urinary-N derived from ruminal ammonia decreased in test diet 2 as compared to that in test diet 1. Better utilization of nitrogen from urea plus ammonium sulphate diets was thus ascribed to additional sulphur availability from ammonium sulphate and proper N : S ratio. (author). 5 tabs., 9 refs

  10. Surface behavior of polyamide 6 modified by barrier plasma in oxygen and nitrogen

    Czech Academy of Sciences Publication Activity Database

    Novák, I.; Popelka, A.; Valentín, M.; Chodák, I.; Špírková, Milena; Tóth, A.; Kleinová, A.; Sedliačik, J.; Lehocký, M.; Maronek, M.

    2014-01-01

    Roč. 19, č. 1 (2014), s. 31-38 ISSN 1023-666X Institutional support: RVO:61389013 Keywords : adhesion * AFM * barrier plasma Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.264, year: 2014

  11. Molecular Mechanisms of Urea Transport in Health and Disease

    Science.gov (United States)

    Klein, Janet D.; Blount, Mitsi A.; Sands, Jeff M.

    2012-01-01

    In the late 1980s, urea permeability measurements produced values that could not be explained by paracellular transport or lipid phase diffusion. The existence of urea transport proteins were thus proposed and less than a decade later, the first urea transporter was cloned. The SLC14A family of urea transporters has two major subgroups, designated SLC14A1 (or UT-B) and Slc14A2 (or UT-A). UT-B and UT-A gene products are glycoproteins located in various extra-renal tissues however, a majority of the resulting isoforms are found in the kidney. The UT-B (Slc14A1) urea transporter was originally isolated from erythrocytes and two isoforms have been reported. In kidney, UT-B is located primarily in the descending vasa recta. The UT-A (Slc14A2) urea transporter yields 6 distinct isoforms, of which 3 are found chiefly in the kidney medulla. UT-A1 and UT-A3 are found in the inner medullary collecting duct (IMCD), while UT-A2 is located in the thin descending limb. These transporters are crucial to the kidney’s ability to concentrate urine. The regulation of urea transporter activity in the IMCD involves acute modification through phosphorylation and subsequent movement to the plasma membrane. UT-A1 and UT-A3 accumulate in the plasma membrane in response to stimulation by vasopressin or hypertonicity. Long term regulation of the urea transporters in the IMCD involves altering protein abundance in response to changes in hydration status, low protein diets, or adrenal steroids. Urea transporters have been studied using animal models of disease including diabetes mellitus, lithium intoxication, hypertension, and nephrotoxic drug responses. Exciting new genetically engineered mouse models are being developed to study these transporters. PMID:23007461

  12. Combined effect of protein and oxygen on reactive oxygen and nitrogen species in the plasma treatment of tissue

    Science.gov (United States)

    Gaur, Nishtha; Szili, Endre J.; Oh, Jun-Seok; Hong, Sung-Ha; Michelmore, Andrew; Graves, David B.; Hatta, Akimitsu; Short, Robert D.

    2015-09-01

    The influence of protein and molecular, ground state oxygen (O2) on the plasma generation, and transport of reactive oxygen and nitrogen species (RONS) in tissue are investigated. A tissue target, comprising a 1 mm thick gelatin film (a surrogate for real tissue), is placed on top of a 96-well plate; each well is filled with phosphate buffered saline (PBS, pH 7.4) containing one fluorescent or colorimetric reporter that is specific for one of three RONS (i.e., H2O2, NO2-, or OH•) or a broad spectrum reactive oxygen species reporter (2,7-dichlorodihydrofluorescein). A helium cold atmospheric plasma (CAP) jet contacts the top of the gelatin surface, and the concentrations of RONS generated in PBS are measured on a microplate reader. The data show that H2O2, NO2-, or OH• are generated in PBS underneath the target. Independently, measurements are made of the O2 concentration in the PBS with and without the gelatin target. Adding bovine serum albumin protein to the PBS or gelatin shows that protein either raises or inhibits RONS depending upon the O2 concentration. Our results are discussed in the context of plasma-soft tissue interactions that are important in the development of CAP technology for medicine, biology, and food manufacturing.

  13. Oxygen and nitrogen plasma etching of three-dimensional hydroxyapatite/chitosan scaffolds fabricated by additive manufacturing

    Science.gov (United States)

    Myung, Sung-Woon; Kim, Byung-Hoon

    2016-01-01

    Three-dimensional (3D) chitosan and hydroxyapatite (HAp)/chitosan (CH) scaffolds were fabricated by additive manufacturing, then their surfaces were etched with oxygen (O2) and nitrogen (N2) plasma. O2 and N2 plasma etching was performed to increase surface properties such as hydrophilicity, roughness, and surface chemistry on the scaffolds. After etching, hydroxyapatite was exposed on the surface of 3D HAp/CH scaffolds. The surface morphology and chemical properties were characterized by contact angle measurement, scanning electron microscopy, X-ray diffraction, and attenuated total reflection Fourier infrared spectroscopy. The cell viability of 3D chitosan scaffolds was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The differentiation of preosteoblast cells was evaluated by alkaline phosphatase assay. The cell viability was improved by O2 and N2 plasma etching of 3D chitosan scaffolds. The present fabrication process for 3D scaffolds might be applied to a potential tool for preparing biocompatible scaffolds.

  14. Influence of composted organic waste and urea fertilization on rice ...

    African Journals Online (AJOL)

    The field experiment was conducted at the University of Ghana's Soil and Irrigation Research Centre - Kpong during 2014 and 2015 cropping seasons to evaluate the influence of composted organic waste and urea fertilization on rice yield, Nitrogen-use efficiency and soil chemical characteristics. The study was laid out in a ...

  15. Improvement of NiMoNb to polyimide adhesion by inductively coupled nitrogen plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Bang, S.-H., E-mail: zxclucy@snu.ac.kr

    2016-01-01

    Graphical abstract: - Highlights: • NiMoNb was introduced as the adhesion layer for flexible Cu-clad laminate structure. • The effect of sputtering and plasma power on the peel strength was studied. • Plasma pretreatment in inductively coupled plasma greatly affects the peel strength. • FCCL with NiMoNb adhesion layer show outstanding peel strength. - Abstract: In this study, the effect of sputtering power on the peel strength of the flexible copper clad laminate (FCCL) was evaluated before and after heat treatment using 180° peel test. An increase in the sputtering powers from 200 W to 600 W increased film density and improved peel strength. To enhance peel strength much more, an inductively coupled plasma (ICP) was treated on the PI surface using N{sub 2} gas with Ar as a function of RF power. A dramatic enhancement of the peel strength, 923 N/m was achieved, especially after heat treatment by changing ICP power from 200 W to 900 W. The reduction ratio of the peel strength for the 900 W plasma-treated FCCL was only 12%, whereas that for the 200 W plasma-treated FCCL was 43%. The root mean square (RMS) surface roughness with PIs exposed to both 200 W and 900 W plasma treatments was rarely changed, while X-ray photoelectron spectroscopy (XPS) showed the substantial increase of C–N functional groups. To obtain insight the film characteristics, the NiMoNb/PI interfaces were investigated by a high resolution transmission electron microscopy (HR-TEM).

  16. Nitrogen plasma immersion ion implantation for surface treatment and wear protection of austenitic stainless steel X6CrNiTi1810

    International Nuclear Information System (INIS)

    Blawert, C.; Mordike, B.L.

    1999-01-01

    Plasma immersion ion implantation is an effective surface treatment for stainless steels. The influence of treatment parameters (temperature, plasma density and pressure) on the sliding wear resistance are studied here. At moderate temperatures, nitrogen remains in solid solution without forming nitrides. This increases the surface hardness and the wear resistance without affecting the passivation of the steel. This may allow the use of such steels in applications where their poor wear resistance would normally prohibit their use. (orig.)

  17. Hybrid process for nitrogen oxides reduction

    Energy Technology Data Exchange (ETDEWEB)

    Epperly, W.R.; Sprague, B.N.

    1991-09-10

    This patent describes a process for reducing the nitrogen oxide concentration in the effluent from the combustion of a carbonaceous fuel. It comprises introducing into the effluent a first treatment agent comprising a nitrogenous composition selected from the group consisting of urea, ammonia, hexamethylenetetramine, ammonium salts of organic acids, 5- or 6-membered heterocyclic hydrocarbons having at least one cyclic nitrogen, hydroxy amino hydrocarbons, NH{sub 4}-lignosulfonate, fur-furylamine, tetrahydrofurylamine, hexamethylenediamine, barbituric acid, guanidine, guanidine carbonate, biguanidine, guanylurea sulfate, melamine, dicyandiamide, biuret, 1.1{prime}-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, calcium cyanamide, and mixtures thereof under conditions effective to reduce the nitrogen oxides concentration and ensure the presence of ammonia in the effluent; introducing into the effluent a second treatment agent comprising an oxygenated hydrocarbon at an effluent temperature of about 500{degrees} F. to about 1600{degrees} F. under conditions effective to oxidize nitric oxide in the effluent to nitrogen dioxide and ensure the presence of ammonia at a weight ratio of ammonia to nitrogen dioxide of about 1:5 to about 5:1; and contacting the effluent with an aqueous scrubbing solution having a pH of 12 or lower under conditions effective to cause nitrogen dioxide to be absorbed therein.

  18. Contrasting Features of Urea Cycle Disorders in Human Patients and Knockout Mouse Models

    OpenAIRE

    Deignan, Joshua L.; Cederbaum, Stephen D.; Grody, Wayne W.

    2007-01-01

    The urea cycle exists for the removal of excess nitrogen from the body. Six separate enzymes comprise the urea cycle, and a deficiency in any one of them causes a urea cycle disorder (UCD) in humans. Arginase is the only urea cycle enzyme with an alternate isoform, though no known human disorder currently exists due to a deficiency in the second isoform. While all of the UCDs usually present with hyperammonemia in the first few days to months of life, most disorders are distinguished by a cha...

  19. Non-platinum nanocatalyst on porous nitrogen-doped carbon fabricated by cathodic vacuum arc plasma technique

    Energy Technology Data Exchange (ETDEWEB)

    Sirirak, Reungruthai [Material Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sarakonsri, Thapanee, E-mail: tsarakonsri@gmail.com [Material Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Medhesuwakul, Min [Plasma & Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-11-30

    Highlights: • High surface area porous coral-like nitrogen-doped carbon (NC) and non-platinum nanocatalysts were fabricated on proton exchange membrane using the cathodic vacuum arc plasma (CVAP) technique. • It is a one-step catalysts preparation directly on nafion proton exchange membrane. This CVAP technique is the first new method that was applied in a polymer electrolyte membrane fuel cells (PEMFCs) catalysts preparation. • Due to these excellent characteristics of nitrogen-doped carbon, it is expected to exhibit a good catalyst supporter for PEMFC. • In addition, the Fe–NC catalysts fabricated via this CVAP technique are sphere-like nanoparticle and well disperse on coral-like NC film, which particularity exhibits that these prepared catalysts ought to be a good oxygen reduction reaction (ORR) catalyst for PEMFC. • This approach can be extended to the synthesis of other non-platinum ORR catalyst for broad range applications in energy conversion. - Abstract: Polymer electrolyte membrane fuel cells (PEMFCs) convert chemical energy directly into electrical energy where catalysts composing of non-noble transition metals, nitrogen, and carbon compounds are the most promising materials to replace the expensive platinum catalysts for oxygen reduction reaction (ORR). In this research, cathodic vacuum arc plasma (CVAP) technique was used to fabricate porous nitrogen doped carbon (NC) and non-platinum catalyst on porous NC (Fe–NC) directly on ion exchange membrane for being used as an ORR catalyst at the cathode. The porous NC layer was fabricated on silicon wafer at 0.05 mTorr, 0.1 mTorr, 0.5 mTorr, 1 mTorr, and 5 mTorr of nitrogen gas inlet. The AFM, and SEM images are observed to be regularly big with quite high hillocks and thin NC layers; these results indicate that the optimum process pressure of nitrogen gas inlet is 5 mTorr for porous NC fabrication. The SEM–EDS detects Fe, N, and C elements in the prepared catalysts, and the XRD pattern reviews

  20. Non-platinum nanocatalyst on porous nitrogen-doped carbon fabricated by cathodic vacuum arc plasma technique

    International Nuclear Information System (INIS)

    Sirirak, Reungruthai; Sarakonsri, Thapanee; Medhesuwakul, Min

    2015-01-01

    Highlights: • High surface area porous coral-like nitrogen-doped carbon (NC) and non-platinum nanocatalysts were fabricated on proton exchange membrane using the cathodic vacuum arc plasma (CVAP) technique. • It is a one-step catalysts preparation directly on nafion proton exchange membrane. This CVAP technique is the first new method that was applied in a polymer electrolyte membrane fuel cells (PEMFCs) catalysts preparation. • Due to these excellent characteristics of nitrogen-doped carbon, it is expected to exhibit a good catalyst supporter for PEMFC. • In addition, the Fe–NC catalysts fabricated via this CVAP technique are sphere-like nanoparticle and well disperse on coral-like NC film, which particularity exhibits that these prepared catalysts ought to be a good oxygen reduction reaction (ORR) catalyst for PEMFC. • This approach can be extended to the synthesis of other non-platinum ORR catalyst for broad range applications in energy conversion. - Abstract: Polymer electrolyte membrane fuel cells (PEMFCs) convert chemical energy directly into electrical energy where catalysts composing of non-noble transition metals, nitrogen, and carbon compounds are the most promising materials to replace the expensive platinum catalysts for oxygen reduction reaction (ORR). In this research, cathodic vacuum arc plasma (CVAP) technique was used to fabricate porous nitrogen doped carbon (NC) and non-platinum catalyst on porous NC (Fe–NC) directly on ion exchange membrane for being used as an ORR catalyst at the cathode. The porous NC layer was fabricated on silicon wafer at 0.05 mTorr, 0.1 mTorr, 0.5 mTorr, 1 mTorr, and 5 mTorr of nitrogen gas inlet. The AFM, and SEM images are observed to be regularly big with quite high hillocks and thin NC layers; these results indicate that the optimum process pressure of nitrogen gas inlet is 5 mTorr for porous NC fabrication. The SEM–EDS detects Fe, N, and C elements in the prepared catalysts, and the XRD pattern reviews

  1. An application of nitrogen microwave-induced plasma mass spectrometry to isotope dilution analysis of selenium in marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Shirasaki, Toshihiro [Hitachi Instruments Engineering Co. Ltd., Hitachinaka, Ibaraki (Japan); Yoshinaga, Jun; Morita, Masatoshi; Okumoto, Toyoharu; Oishi, Konosuke

    1996-01-01

    Nitrogen microwave-induced plasma mass spectrometry was studied for its applicability to the isotope dilution analysis of selenium in biological samples. Spectroscopic interference by calcium, which is present in high concentrations in biological samples, was investigated. No detectable background spectrum was observed for the major selenium isotopes of {sup 78}Se and {sup 80}Se. No detectable interferences by sodium, potassium, calcium and phosphorus on the isotope ratio {sup 80}Se/{sup 78}Se were observed up to concentration of 200 mg/ml. The method was applied to the analysis of selenium in biological reference materials of marine organisms. The results showed good agreement between the certified and found values. (author).

  2. Extremely high-power-density atmospheric-pressure thermal plasma jet generated by the nitrogen-boosted effect

    Science.gov (United States)

    Hanafusa, Hiroaki; Nakashima, Ryosuke; Nakano, Wataru; Higashi, Seiichiro

    2018-06-01

    In this study, the effect of N2 addition to an atmospheric-pressure Ar thermal plasma jet (TPJ) on ultrarapid heating was investigated. With increasing N2 flow rate, a boost of arc voltage to ∼36 V was observed, which significantly improved heating characteristics. As a result, a drastic power density increase from 10 to 125 kW/cm2 was achieved with the addition of 2.0 L/min N2 to 3.0 L/min Ar. The results of optical emission analysis and heating characteristics evaluation implied that dissociation and recombination of N2 molecules and the high thermal transport property of nitrogen gas play important roles in the increase in TPJ power density. Furthermore, we obtained TPJ extension with N2 addition that reached 300 mm, and it showed spatial enhancement of heat transport characteristics.

  3. Balanço do nitrogênio da uréia (15N no sistema solo-planta na implantação da semeadura direta na cultura do milho Balance of nitrogen from urea (15N in the soil-plant system at the establishment of no-till in maize

    Directory of Open Access Journals (Sweden)

    Glauber José de Castro Gava

    2006-01-01

    and partitioning of the phytomass, in the accumulation of total nitrogen and nitrogen in the plant derived from the fertilizer, by using the 15N side-dressing fertilization at the establishment of no-till management. The experiment was carried out in a Nitosol at Água Sumida Farm located near Barra Bonita, State of São Paulo. The experiment was arranged in completely randomized block design, with 4 replicates. The following treatments were studied: conventional tillage system (one ploughing and two harrowings and no-tilllage, both fertilized with urea (15N applied at the rate of 100 kg ha-1 nitrogen. All treatments were subjected to sowing fertilization, by applying 25 kg ha-1 N as urea, 80 kg ha-1 P2O5 as simple superphosphate and 60 kg ha-1 K2O as potassium chloride. At the end of the phenological cycle, the following comparisons among the treatments were performed: crop yeld; nitrogen accumulation in the aerial and underground parts; use of nitrogen from urea (15N and residual nitrogen in the soil. The modifications of the soil caused by implantation of no-till neither restricted the availability of nitrogen to maize plants, nor the production of dry matter. The use efficiency of nitrogen fertilization of maize plants and the recovery of the soil nitrogen fertilizer were around 45% and 30%, respectively, for the urea-N side-dressing fertilization in both conventional and no-till systems. Nitrogen applied as side-dressing fertilization, and not recovered from urea (NNR averaged 25%, independently of the sowing system.

  4. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Directory of Open Access Journals (Sweden)

    Hye Yeon Seo

    Full Text Available The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ, elicited from one of two different gas sources (nitrogen and air, to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in

  5. Phosphorus effect on the uptake, translocation and accumulation of the 14C-urea in orchard grass (Dactylis glomerata L.)

    International Nuclear Information System (INIS)

    Panak, H.; Nowak, G.; Nowak, J.; Akademia Rolniczo-Technicza, Olsztyn

    1981-01-01

    The effect of different phosphorus supplies on the uptake, translocation and accumulation of 14 C-urea by orchard grass was investigated. Phosphorus starvation inhibits the uptake, translocation and accumulation of the carbon of urea similarly to the nitrogen of urea. As compared with the uptake process the reduction of the accumulation is much more effected by the inhibition of the carbon translocation from roots to the aboveground parts. Lack of phosphorus also decreases the incorporation of the 14 C of urea into high-molecular compounds. The effect of phosphorus deficit on the accumulation of 14 C-urea increases with time of starvation. (orig.)

  6. A comparative study of nitrogen plasma effect on field emission characteristics of single wall carbon nanotubes synthesized by plasma enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avshish; Parveen, Shama; Husain, Samina; Ali, Javid [Department of Physics, Jamia Millia Islamia (A Central University), New Delhi 110025 (India); Zulfequar, Mohammad [Department of Physics, Jamia Millia Islamia (A Central University), New Delhi 110025 (India); Centre for Nanoscience and Nanotechnology, Jamia Millia Islamia (A Central University), New Delhi 110025 (India); Harsh [Centre for Nanoscience and Nanotechnology, Jamia Millia Islamia (A Central University), New Delhi 110025 (India); Husain, Mushahid, E-mail: mush_reslab@rediffmail.com [Department of Physics, Jamia Millia Islamia (A Central University), New Delhi 110025 (India); Centre for Nanoscience and Nanotechnology, Jamia Millia Islamia (A Central University), New Delhi 110025 (India)

    2014-12-15

    Highlights: • Vertically aligned single wall carbon nanotubes (SWCNTs) have been successfully grown on nickel (Ni) deposited silicon substrate. • The diameter distribution of the grown (SWCNTs) is in the range 1–2 nm. • A current density of 25.0 mA/cm{sup 2} at 1.9 V/μm of the grown SWCNTs is observed with a high turn-on field (E{sub to}) of 1.3 V/μm. • After N{sub 2} nitrogen plasma treatment, huge current density of 81.5 mA/cm{sup 2} at 2.0 V/μm was recorded with low E{sub to} of 1.2 V/μm. • The comparison of these two typical results indicates a drastic enhancement in the field emission properties after plasma treatments. - Abstract: Vertically aligned single wall carbon nanotubes (SWCNTs) with large scale control of diameter, length and alignment have successfully been grown by plasma enhanced chemical vapor deposition (PECVD) system. The nickel (Ni) as catalyst deposited on silicon (Si) substrate was used to grow the SWCNTs. Field emission (FE) characteristics of the as grown SWCNTs were measured using indigenously designed setup in which a diode is configured in such a way that by applying negative voltage on the copper plate (cathode) with respect to stainless steel anode plate, current density can be recorded. To measure the FE characteristics, SWCNTs film pasted on the copper plate with silver epoxy was used as electron emitter source. The effective area of anode was ∼78.5 mm{sup 2} for field emission measurements. The emission measurements were carried out under high vacuum pressure of the order of 10{sup −6} Torr to minimize the electron scattering and degradation of the emitters. The distance between anode and cathode was kept 500 μm (constant) during entire field emission studies. The grown SWCNTs are excellent field emitters, having emission current density higher than 25 mA/cm{sup 2} at turn-on field 1.3 V/μm. In order to enhance the field emission characteristics, the as grown SWCNTs have been treated under nitrogen (N{sub 2

  7. Comparative study on contribution of charge-transfer collision to excitations of iron ion between argon radio-frequency inductively-coupled plasma and nitrogen microwave induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Kozue; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2015-06-01

    This paper describes an ionization/excitation phenomenon of singly-ionized iron occurring in an Okamoto-cavity microwave induced plasma (MIP) as well as an argon radio-frequency inductively-coupled plasma (ICP), by comparing the Boltzmann distribution among iron ionic lines (Fe II) having a wide range of the excitation energy from 4.76 to 9.01 eV. It indicated in both the plasmas that plots of Fe II lines having lower excitation energies (4.76 to 5.88 eV) were fitted on each linear relationship, implying that their excitations were caused by a dominant thermal process such as collision with energetic electron. However, Fe II lines having higher excitation energies (more than 7.55 eV) had a different behavior from each other. In the ICP, Boltzmann plots of Fe II lines assigned to the higher excited levels also followed the normal Boltzmann relationship among the low-lying excited levels, even including a deviation from it in particular excited levels having an excitation energy of ca. 7.8 eV. This deviation can be attributed to a charge-transfer collision with argon ion, which results in the overpopulation of these excited levels, but the contribution is small. On the other hand, the distribution of the high-lying excited levels was non-thermal in the Okamoto-cavity MIP, which did not follow the normal Boltzmann relationship among the low-lying excited levels. A probable reason for the non-thermal characteristics in the MIP is that a charge-transfer collision with nitrogen molecule ion having many vibrational/rotational levels could work for populating the 3d{sup 6}4p (3d{sup 5}4s4p) excited levels of iron ion broadly over an energy range of 7.6–9.0 eV, while collisional excitation by energetic electron would occur insufficiently to excite these high-energy levels. - Highlights: • This paper describes the excitation mechanism of iron ion in Okamoto-cavity MIP in comparison with conventional ICP. • Boltzmann distribution is studied among iron ionic lines of

  8. Effects of nitrogen seeding on core ion thermal transport in JET ILW L-mode plasmas

    NARCIS (Netherlands)

    Bonanomi, N.; Mantica, P.; Citrin, J.; Giroud, C.; Lerche, E.; Sozzi, C.; Taylor, D.; Tsalas, M.; Van Eester, D.; JET Contributors,

    2018-01-01

    A set of experiments was carried out in JET ILW (Joint European Torus with ITER-Like Wall) L-mode plasmas in order to study the effects of light impurities on core ion thermal transport. N was puffed into some discharges and its profile was measured by active Charge Exchange diagnostics, while ICRH

  9. Omics insights into rumen ureolytic bacterial community and urea metabolism in dairy cows

    OpenAIRE

    Jin, Di

    2017-01-01

    Urea has been used in the diets of ruminants as a non-protein nitrogen source. Ureolytic bacteria are key organisms in the rumen producing urease enzymes to catalyze the breakdown of urea to ammonia (NH3), and the NH3 is used as nitrogen for microbial protein synthesis. In the rumen, hydrolysis of urea to NH3 occurs at a greater rate than NH3 can be utilized by rumen bacteria, and excess ammonia absorbed into blood may be harmful to the animals. Nowadays, little is known about the information...

  10. Nitrogen fixation and growth response of Alnus Rubra following fertiliztion with urea or biosolids Fixação de nitrogênio e crescimento de Alnus Rubra fertilização com uréia ou biosólidos

    Directory of Open Access Journals (Sweden)

    Linda S. Gaulke

    2006-08-01

    Full Text Available Nitrogen fertilization of forests using biosolids offers a potentially environmentally friendly means to accelerate tree growth. This field study was designed to analyze the effects of nitrogen fertilization on the symbiotic, nitrogen (N-fixing relationship between Alnus rubra Bong. (red alder and Frankia. Anaerobically digested, class B biosolids and synthetic urea (46% N were applied at rates of 140, 280 and 560 kg ha-1 available N to a well-drained, sandy, glacial outwash soil in the Indianola series (mixed, mesic Dystric Xeropsamments. Plots were planted with A. rubra seedlings. At the end of each of two growing seasons trees were harvested and analyzed for the rate of N fixation (as acetylene reduction activity, biomass and foliar N. At year 1, there was no N fixation for trees grown with urea amendments, but control (17 µmol C2H4 g-1 hr-1 and biosolids (26-45 µmol C2H4 g-1 hr-1 trees were fixing N. At the end of year 2, all trees in all treatments were fixing N (7 µmol C2H4 g-1 hr-1, 4-16 µmol C2H4 g-1 hr-1, and 20-29 µmol C2H4 g-1 hr-1 for control, urea and biosolids respectively. Trees grown with biosolids amendments were larger overall (year 1 shoot biomass 10 g, 5 g, and 23 g for control, urea, and biosolids respectively, year 2 shoot biomass 50 g, 51 g, and 190 g for control, urea, and biosolids respectively with higher concentrations of foliar N for both years of the study (year 1 foliar N 26 g kg-1, 27 g kg-1, and 40 g kg-1 for control, urea, and biosolids respectively, year 2 foliar N 17 g kg-1, 19 g kg-1, and 23 g kg-1 for control, urea, and biosolids respectively. Trees grown with urea amendments appeared to use the urea N over Frankia supplied N, whereas the biosolids trees appeared to be able to use both N in biosolids and N from Frankia. The results from this study indicated that the greater growth of A. rubra may have been responsible for the observed higher N demand. Biosolids may have supplied other nutrients to the

  11. Effect of nitrogen environment on NdFeB thin films grown by radio frequency plasma beam assisted pulsed laser deposition

    International Nuclear Information System (INIS)

    Constantinescu, C.; Patroi, E.; Codescu, M.; Dinescu, M.

    2013-01-01

    Highlights: ► NdFeB thin films grown by PLD, in vacuum and in nitrogen, are presented. ► Nitrogen inclusion in thin film structures is related to improved coercitivity. ► Magnetical, optical and morphological properties of the thin films are discussed. - Abstract: NdFeB is a very attractive material for applications in electrical engineering and in electronics, for high-tech devices where high coercive field and high remanence are needed. In this paper we demonstrate that the deposition of nitrogen doped NdFeB thin films by pulsed laser deposition, in the presence of a nitrogen radiofrequency plasma beam, exhibit improved magnetic properties and surface morphology, when compared to vacuum deposited NdFeB layers. A Nd:YAG pulsed laser (3ω and 4ω) was focused on a NdFeB target, in vacuum, or in the presence of a nitrogen plasma beam. Substrate temperature (RT-850 °C), nitrogen gas pressure, and radiofrequency power (75–150 W), were particularly varied. The thin films were investigated by means of X-ray diffraction, atomic force microscopy, scanning electron microscopy, spectroscopic-ellipsometry, and vibrating sample magnetometry.

  12. Effect of nitrogen environment on NdFeB thin films grown by radio frequency plasma beam assisted pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Constantinescu, C., E-mail: catalin.constantinescu@inflpr.ro [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor bd., Magurele, RO-077125, Bucharest (Romania); Patroi, E.; Codescu, M. [National Institute for Research and Development in Electrical Engineering - Advanced Research, 313 Spl. Unirii, Sector 3, RO-030138, Bucharest (Romania); Dinescu, M. [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor bd., Magurele, RO-077125, Bucharest (Romania)

    2013-03-01

    Highlights: Black-Right-Pointing-Pointer NdFeB thin films grown by PLD, in vacuum and in nitrogen, are presented. Black-Right-Pointing-Pointer Nitrogen inclusion in thin film structures is related to improved coercitivity. Black-Right-Pointing-Pointer Magnetical, optical and morphological properties of the thin films are discussed. - Abstract: NdFeB is a very attractive material for applications in electrical engineering and in electronics, for high-tech devices where high coercive field and high remanence are needed. In this paper we demonstrate that the deposition of nitrogen doped NdFeB thin films by pulsed laser deposition, in the presence of a nitrogen radiofrequency plasma beam, exhibit improved magnetic properties and surface morphology, when compared to vacuum deposited NdFeB layers. A Nd:YAG pulsed laser (3{omega} and 4{omega}) was focused on a NdFeB target, in vacuum, or in the presence of a nitrogen plasma beam. Substrate temperature (RT-850 Degree-Sign C), nitrogen gas pressure, and radiofrequency power (75-150 W), were particularly varied. The thin films were investigated by means of X-ray diffraction, atomic force microscopy, scanning electron microscopy, spectroscopic-ellipsometry, and vibrating sample magnetometry.

  13. Neurological implications of urea cycle disorders

    Science.gov (United States)

    Summar, M.; Leonard, J. V.

    2013-01-01

    Summary The urea cycle disorders constitute a group of rare congenital disorders caused by a deficiency of the enzymes or transport proteins required to remove ammonia from the body. Via a series of biochemical steps, nitrogen, the waste product of protein metabolism, is removed from the blood and converted into urea. A consequence of these disorders is hyperammonaemia, resulting in central nervous system dysfunction with mental status changes, brain oedema, seizures, coma, and potentially death. Both acute and chronic hyperammonaemia result in alterations of neurotransmitter systems. In acute hyperammonaemia, activation of the NMDA receptor leads to excitotoxic cell death, changes in energy metabolism and alterations in protein expression of the astrocyte that affect volume regulation and contribute to oedema. Neuropathological evaluation demonstrates alterations in the astrocyte morphology. Imaging studies, in particular 1H MRS, can reveal markers of impaired metabolism such as elevations of glutamine and reduction of myoinositol. In contrast, chronic hyperammonaemia leads to adaptive responses in the NMDA receptor and impairments in the glutamate–nitric oxide–cGMP pathway, leading to alterations in cognition and learning. Therapy of acute hyperammonaemia has relied on ammonia-lowering agents but in recent years there has been considerable interest in neuroprotective strategies. Recent studies have suggested restoration of learning abilities by pharmacological manipulation of brain cGMP with phosphodiesterase inhibitors. Thus, both strategies are intriguing areas for potential investigation in human urea cycle disorders. PMID:18038189

  14. Comparison of plasma generated nitrogen fertilizer to conventional fertilizers ammonium nitrate and sodium nitrate for pre-emergent and seedling growth

    Science.gov (United States)

    Andhavarapu, A.; King, W.; Lindsay, A.; Byrns, B.; Knappe, D.; Fonteno, W.; Shannon, S.

    2014-10-01

    Plasma source generated nitrogen fertilizer is compared to conventional nitrogen fertilizers in water for plant growth. Root, shoot sizes, and weights are used to examine differences between plant treatment groups. With a simple coaxial structure creating a large-volume atmospheric glow discharge, a 162 MHz generator drives the air plasma. The VHF plasma source emits a steady state glow; the high drive frequency is believed to inhibit the glow-to-arc transition for non-thermal discharge generation. To create the plasma activated water (PAW) solutions used for plant treatment, the discharge is held over distilled water until a 100 ppm nitrate aqueous concentration is achieved. The discharge is used to incorporate nitrogen species into aqueous solution, which is used to fertilize radishes, marigolds, and tomatoes. In a four week experiment, these plants are watered with four different solutions: tap water, dissolved ammonium nitrate DI water, dissolved sodium nitrate DI water, and PAW. Ammonium nitrate solution has the same amount of total nitrogen as PAW; sodium nitrate solution has the same amount of nitrate as PAW. T-tests are used to determine statistical significance in plant group growth differences. PAW fertilization chemical mechanisms are presented.

  15. Hydrophobic recovery of repeatedly plasma-treated silicone rubber .2. A comparison of the hydrophobic recovery in air, water, or liquid nitrogen

    NARCIS (Netherlands)

    Everaert, EP; VanderMei, HC; Busscher, HJ

    1996-01-01

    Surfaces of medical grade silicone rubber (Q7-4750, Dow Coming) were modified by repeated (six times) RF plasma treatments using various discharge gases: oxygen, argon, carbon dioxide, and ammonia. The treated samples were stored for a period of 3 months in ambient air, water, or liquid nitrogen.

  16. Characteristics of an Electron Cyclotron Resonance Plasma Source for the Production of Active Nitrogen Species in III-V Nitride Epitaxy

    Science.gov (United States)

    Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

    1997-01-01

    A simple analysis is provided to determine the characteristics of an electron cyclotron resonance (ECR) plasma source for the generation of active nitrogen species in the molecular beam epitaxy of III-V nitrides. The effects of reactor geometry, pressure, power, and flow rate on the dissociation efficiency and ion flux are presented. Pulsing the input power is proposed to reduce the ion flux.

  17. The emerging physiological roles of the SLC14A family of urea transporters

    Science.gov (United States)

    Stewart, Gavin

    2011-01-01

    In mammals, urea is the main nitrogenous breakdown product of protein catabolism and is produced in the liver. In certain tissues, the movement of urea across cell membranes is specifically mediated by a group of proteins known as the SLC14A family of facilitative urea transporters. These proteins are derived from two distinct genes, UT-A (SLC14A2) and UT-B (SLC14A1). Facilitative urea transporters play an important role in two major physiological processes – urinary concentration and urea nitrogen salvaging. Although UT-A and UT-B transporters both have a similar basic structure and mediate the transport of urea in a facilitative manner, there are a number of significant differences between them. UT-A transporters are mainly found in the kidney, are highly specific for urea, have relatively lower transport rates and are highly regulated at both gene expression and cellular localization levels. In contrast, UT-B transporters are more widespread in their tissue location, transport both urea and water, have a relatively high transport rate, are inhibited by mercurial compounds and currently appear to be less acutely regulated. This review details the fundamental research that has so far been performed to investigate the function and physiological significance of these two types of urea transporters. PMID:21449978

  18. Localization and regulation of a facilitative urea transporter in the kidney of the red-eared slider turtle (Trachemys scripta elegans).

    Science.gov (United States)

    Uchiyama, Minoru; Kikuchi, Ryosuke; Konno, Norifumi; Wakasugi, Tatsuya; Matsuda, Kouhei

    2009-01-01

    Urea is the major excretory end product of nitrogen metabolism in most chelonian reptiles. In the present study, we report the isolation of a 1632 base pair cDNA from turtle kidney with one open reading frame putatively encoding a 403-residue protein, the turtle urea transporter (turtle UT). The first cloned reptilian UT has high homology with UTs (facilitated urea transporters) cloned from vertebrates, and most closely resembles the UT-A subfamily. Injection of turtle UT cRNA into Xenopus oocytes induced a 6-fold increase in [(14)C]urea uptake that was inhibited by phloretin. The turtle UT mRNA expression and tissue distribution were examined by RT-PCR with total RNA from various tissues. Expression of turtle UT mRNA was restricted to the kidney, and no signal was detected in the other tissues, such as brain, heart, alimentary tract and urinary bladder. An approximately 58 kDa protein band was detected in membrane fractions of the kidney by western blot using an affinity-purified antibody that recognized turtle UT expressed in Xenopus oocytes. In an immunohistochemical study using the anti-turtle UT antibody, UT-immunopositive cells were observed along the distal tubule but not in the collecting duct. In turtles under dry conditions, plasma osmolality and urea concentration increased, and using semi-quantitative RT-PCR the UT mRNA expression level in the kidney was found to increase 2-fold compared with control. The present results, taken together, suggest that the turtle UT probably contributes to urea transport in the distal tubule segments of the kidney in response to hyperosmotic stress under dry conditions.

  19. Analysis of the polymeric film and fine dust obtained in plasma of acetylene and acetylene-nitrogen

    International Nuclear Information System (INIS)

    Rojas, Andres F; Ortiz, Jairo A; Devia Alfonso

    1998-01-01

    The results are presented from the resistance analyses to the corrosion of the polymeric covering obtained in plasma of acetylene, on a substrata of aluminum alloy, with the techniques of metallographic analysis, infrared and electrochemical, as much for the fine dust as for the grown film on aluminum. Also, the results of the electrochemical test of polarization made to these films will be shown, which demonstrated an improvement of 2.6 and 4.6 times in the resistance to the corrosion when the material treaty is exposed NaCl 0.2 N and Na H2 PO4 01 M, respectively, in comparison with the substrata without recovering. For the movie obtained in acetylene /nitrogen plasma on steel 1016 the micrographs of the superficial structure of the material they will be shown before and after being treated, which were used to measure the thickness of the cover; also, it will be given to know the results of the tests of adhesion and qualitative analysis of resistance before diverse chemical agents (such as: Benzene, Toluene, H2SO4, HNO3, NaCl, CACO3 NaOH and KOH) and the resistance results are presented from the cover to them

  20. Generation and Role of Reactive Oxygen and Nitrogen Species Induced by Plasma, Lasers, Chemical Agents, and Other Systems in Dentistry

    Science.gov (United States)

    Jha, Nayansi; Ryu, Jae Jun

    2017-01-01

    The generation of reactive oxygen and nitrogen species (RONS) has been found to occur during inflammatory procedures, during cell ischemia, and in various crucial developmental processes such as cell differentiation and along cell signaling pathways. The most common sources of intracellular RONS are the mitochondrial electron transport system, NADH oxidase, and cytochrome P450. In this review, we analyzed the extracellular and intracellular sources of reactive species, their cell signaling pathways, the mechanisms of action, and their positive and negative effects in the dental field. In dentistry, ROS can be found—in lasers, photosensitizers, bleaching agents, cold plasma, and even resin cements, all of which contribute to the generation and prevalence of ROS. Nonthermal plasma has been used as a source of ROS for biomedical applications and has the potential for use with dental stem cells as well. There are different types of dental stem cells, but their therapeutic use remains largely untapped, with the focus currently on only periodontal ligament stem cells. More research is necessary in this area, including studies about ROS mechanisms with dental cells, along with the utilization of reactive species in redox medicine. Such studies will help to provide successful treatment modalities for various diseases. PMID:29204250

  1. Unmasked adult-onset urea cycle disorders in the critical care setting.

    Science.gov (United States)

    Summar, Marshall L; Barr, Frederick; Dawling, Sheila; Smith, Wendy; Lee, Brendan; Singh, Rani H; Rhead, William J; Sniderman King, Lisa; Christman, Brian W

    2005-10-01

    Most often, urea cycle disorders have been described as acute onset hyperammonemia in the newborn period; however, there is a growing awareness that urea cycle disorders can present at almost any age, frequently in the critical care setting. This article presents three cases of adult-onset hyperammonemia caused by inherited defects in nitrogen processing in the urea cycle, and reviews the diagnosis, management, and pathophysiology of adult-onset urea cycle disorders. Individuals who have milder molecular urea cycle defects can lead a relatively normal life until a severe environmental stress triggers a hyperammonemic crisis. Comorbid conditions such as physical trauma often delay the diagnosis of the urea cycle defect. Prompt recognition and treatment are essential in determining the outcome of these patients.

  2. Etching of uranium dioxide in nitrogen trifluoride RF plasma glow discharge

    Science.gov (United States)

    Veilleux, John Mark

    1999-10-01

    A series of room temperature, low pressure (10.8 to 40 Pa), low power (25 to 210 W) RF plasma glow discharge experiments with UO2 were conducted to demonstrate that plasma treatment is a viable method for decontaminating UO2 from stainless steel substrates. Experiments were conducted using NF3 gas to decontaminate depleted uranium dioxide from stainless-steel substrates. Results demonstrated that UO2 can be completely removed from stainless-steel substrates after several minutes processing at under 200 W. At 180 W and 32.7 Pa gas pressure, over 99% of all UO2 in the samples was removed in just 17 minutes. The initial etch rate in the experiments ranged from 0.2 to 7.4 mum/min. Etching increased with the plasma absorbed power and feed gas pressure in the range of 10.8 to 40 Pa. A different pressure effect on UO2 etching was also noted below 50 W in which etching increased up to a maximum pressure, ˜23 Pa, then decreased with further increases in pressure. A computer simulation, CHEMKIN, was applied to predict the NF3 plasma species in the experiments. The code was validated first by comparing its predictions of the NF3 plasma species with mass spectroscopy etching experiments of silicon. The code predictions were within +/-5% of the measured species concentrations. The F atom radicals were identified as the primary etchant species, diffusing from the bulk plasma to the UO2 surface and reacting to form a volatile UF6, which desorbed into the gas phase to be pumped away. Ions created in the plasma were too low in concentration to have a major effect on etching, but can enhance the etch rate by removing non-volatile reaction products blocking the reaction of F with UO2. The composition of these non-volatile products were determined based on thermodynamic analysis and the electronic structure of uranium. Analysis identified possible non-volatile products as the uranium fluorides, UF2-5, and certain uranium oxyfluorides UO2F, UO2F2, UOF3, and UOF 4 which form over the

  3. Nitrogen plasma formation through terahertz-induced ultrafast electron field emission

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Zalkovskij, Maksim; Strikwerda, Andrew

    2015-01-01

    Electron microscopy and electron diffraction techniques rely on electron sources. Those sources require strong electric fields to extract electrons from metals, either by the photoelectric effect, driven by multiphoton absorption of strong laser fields, or in the static field emission regime....... Terahertz (THz) radiation, commonly understood to be nonionizing due to its low photon energy, is here shown to produce electron field emission. We demonstrate that a carrier-envelope phase-stable single-cycle optical field at THz frequencies interacting with a metallic microantenna can generate...... and accelerate ultrashort and ultrabright electron bunches into free space, and we use these electrons to excite and ionize ambient nitrogen molecules near the antenna. The associated UV emission from the gas forms a novel THz wave detector, which, in contrast with conventional photon-counting or heat...

  4. Hydrogen bonding of formamide, urea, urea monoxide and their thio

    Indian Academy of Sciences (India)

    Ab initio and DFT methods have been employed to study the hydrogen bonding ability of formamide, urea, urea monoxide, thioformamide, thiourea and thiourea monoxide with one water molecule and the homodimers of the selected molecules. The stabilization energies associated with themonohydrated adducts and ...

  5. Surface modification of biphasic calcium phosphate scaffolds by non-thermal atmospheric pressure nitrogen and air plasma treatment for improving osteoblast attachment and proliferation

    International Nuclear Information System (INIS)

    Choi, Yu-Ri; Kwon, Jae-Sung; Song, Doo-Hoon; Choi, Eun Ha; Lee, Yong-Keun; Kim, Kyoung-Nam; Kim, Kwang-Mahn

    2013-01-01

    Surface modifications induced by non-thermal plasma have been used extensively in biomedical applications. The attachment and proliferation of osteoblast cells are important in bone tissue engineering using scaffolds. Hence the effect of non-thermal plasma on hydroxyapatite/β-tri-calcium phosphate (HA/β-TCP) scaffolds in terms of improving osteoblast attachment and proliferation was investigated. Experimental groups were treated with non-thermal plasma for 10 min and 20 min and a control group was not treated with non-thermal plasma. For surface chemistry analysis, X-ray photoelectron spectroscopy (XPS) analysis was carried out. The hydrophilicity was determined from contact angle measurement on the surface. Atomic force microscopy analysis (AFM) was used to test the change in surface roughness and cell attachment and proliferation were evaluated using MC3T3-E1 osteoblast cells. XPS spectra revealed a decreased amount of carbon on the surface of the plasma-treated sample. The contact angle was also decreased following plasma treatment, indicating improved hydrophilicity of plasma-treated surfaces compared to the untreated disc. A significant increase in MC3T3E-1 cell attachment and proliferation was noted on plasma-treated samples as compared to untreated specimens. The results suggest that non-thermal atmospheric pressure nitrogen and air plasma treatments provide beneficial surface characteristics on HA/β-TCP scaffolds. - Highlights: ► Non-thermal plasma increased OH- and decreased C on biphasic scaffold. ► Non-thermal plasma had no effect on surface roughness. ► Non-thermal plasma resulted in hydrophilic surface. ► Non-thermal plasma resulted in better cell attachment and proliferation. ► Non-thermal plasma treatment on biphasic scaffold is useful for tissue engineering

  6. Nitrogen loss by volatilization of nitrogen fertilizers applied to coffee orchard

    Directory of Open Access Journals (Sweden)

    Anderson William Dominghetti

    2016-04-01

    Full Text Available ABSTRACT Ammonia volatilization (N-NH3 is one of the main pathways of Nitrogen loss reducing nitrogen use efficiency in coffee orchard. This work aimed at quantifying ammonia volatilization (N-NH3 losses from N-sources to be used in coffee plantations fertilization in Brazil. The experiment was conducted in the field on a dystrophic red latosol (Ferralsol in FAO's classification at the Coffee Research Sector, University of Lavras, MG, Brazil. The experimental design was of complete randomized blocks with three repetitions of the following treatments: conventional urea, ammonium nitrate and urea + 0.15% Cu and 0.4% B, urea + anionic polymers, urea + elementary sulfur (S0 + polymers, and urea + plastic resin. These N sources were split into three doses of 150 kg ha-1 and band applied. The N-NH3 losses by volatilization and variations of pH (H2O were measured, before and after N application. The N-sources contributed to reduce the soil pH, measured after the third nitrogen fertilization. The N-NH3 losses by volatilization (average from three applications was as follows: urea + anionic polymers (35.8% > conventional urea (31.2% = urea + S0 + polymers (31.0% > urea + 0.15% Cu + 0.4 % B (25.6% > urea + plastic resin (8.6% = ammonium nitrate (1.0%.

  7. Modification of the Steel Surface Treated by a Volume Discharge Plasma in Nitrogen at Atmospheric Pressure

    Science.gov (United States)

    Erofeev, M. V.; Shulepov, M. A.; Ivanov, Yu. F.; Oskomov, K. V.; Tarasenko, V. F.

    2016-03-01

    Effect of volume discharge plasma initiated by an avalanche electron beam on the composition, structure, and properties of the surface steel layer is investigated. Voltage pulses with incident wave amplitude up to 30 kV, full width at half maximum of about 4 ns, and wave front of about 2.5 ns were applied to the gap with an inhomogeneous electric field. Changes indicating the hardening effect of the volume discharge initiated by an avalanche electron beam are revealed in St3-grade steel specimens treated by the discharge of this type.

  8. Urea and ammonia excretion into gastric juice in regularly dialyzed patients and patients after renal transplantation. I. Dialyzed patients.

    Science.gov (United States)

    Skála, I; Marecková, O; Růzicková, J; Bláha, J; Straková, M; Reneltová, I; Jirka, J; Kocandrle, V; Zvolánková, K

    1978-01-01

    In regularly dialyzed patients in basal gastric juice and after stimulation with pentagastrin the volume of titrable acidity, urea and ammonia were assessed. It was revealed that in relation to the plasma urea concentration in basal juice the mean urea and ammonia concentration is roughly half and in stimulation juice roughly one third. The urea concentration in gastric juice is negatively correlated to the ammonia concentration. Urea excretion into the stomach depends on the plasma urea level and on the secretory gastric activity. The decisive factor of gastric secretion is probably parietal cell secretion. From the results ensues that gastric juice of dialyzed patients contains a quantitatively significant amount of urea and ammonia. Ammonia due to its neutralizing action distorts the examination of gastric acidity assessed by titration. The findings call for a revision of hitherto known data concerning gastric secretion of uraemic patients.

  9. Effects of urea foliar application and of ammonium sulphate and urea applied to the soil on yield and N utilization by beans (Phaseolus vulgaris L.)

    International Nuclear Information System (INIS)

    Muraoka, T.; Victoria, R.L.; Oliveira, J.P.; Boaretto, A.E.

    1984-01-01

    The effects of nitrogen applied to the soil (as ammonium sulphate and urea) and foliar application of urea supplementing or not the soil application, on bean yield and nitrogen utilization are studied in a cerrado soil. Labelled ammonium sulphate is applied at the rate of 20Kg N/ha at seeding or 15 or 25 days after seeding and 40 Kg N/ha at seeding or in two different applications. Labelled urea is applied at the rate of 20kg N/ha at seeding and 40 Kg N/ha splitted. Foliar application is done at 15,22, 29,36 and 45 days after seeding, with 2% urea solution labelled with 10% 15 N. (M.A.C.) [pt

  10. Surface modification by nitrogen plasma immersion ion implantation into new steel 460Li–21Cr in a capacitively coupled radio frequency discharge

    International Nuclear Information System (INIS)

    Bhuyan, H.; Mändl, S.; Bora, B.; Favre, M.; Wyndham, E.; Maze, J.R.; Walczak, M.; Manova, D.

    2014-01-01

    Highlights: • Nitriding of a novel steel has been done in a RF plasma by PIII technique. • Improved hardness and wear behavior have been observed. • Hardness was improved by a factor 4 and the wear by 2 orders of magnitude. • Fast, anomalous diffusion, similar to nitrogen in expanded austenite is observed. - Abstract: A novel steel 460Li–21Cr belonging to a new generation of superferritic grade steel has been implanted with nitrogen in a low power 13.56 MHz radio frequency plasma by the plasma immersion ion implantation (PIII) technique in order to study its physical and chemical properties under different experimental conditions. We observed improved hardness and wear behavior of 460Li–21Cr steel with a layer thickness between 1.5 and 4.0 μm after 60 min implantation in the temperature range from 350 to 550 °C. The modified surface layer containing nitrogen does not show CrN in X-ray diffraction (XRD). Compared to untreated substrates, the hardness can be increased by a factor of 4, depending on the experimental conditions, and the wear behavior was also improved by two orders of magnitude. The results are very similar to those for austenitic stainless steel with a similar pronounced increase in wear resistance and plateau-like nitrogen depth profiles

  11. Plasma Levels of Uric Acid, Urea and Creatinine in Diabetics Who Visit the Clinical Analysis Laboratory (CAn-Lab) at Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

    Science.gov (United States)

    Amartey, N A A; Nsiah, K; Mensah, F O

    2015-02-01

    Diabetes mellitus is one of the most common metabolic diseases worldwide. This metabolic disorder contributes greatly to the significant proportion of the burden of renal damage and dysfunction. The aim of the study was to investigate the renal function of the diabetic patients who visit the Clinical Analysis Laboratory (CAn-Lab) at the Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana. Demographic data as well as medical history were obtained through the administration of a questionnaire. Anthro-pometric measurements were taken and blood samples were analysed for glucose, uric acid, urea and creatinine. Data collected were analysed using SPSS version 16.0. A total of 34 diabetic patients, aged from 40-77 y were recruited, 22 (64.7%) of them were males with mean age of 57.40 ± 11.8 y (±SD), while 12 (35.3%) were females with mean age of 58.17 ± 7.47 y. There was a statistically significant difference between the mean duration of the disease, as the females had longer duration, 12.50 ± 6.95 y, as compared to 7.32 ± 4.48 y in males (p=0.033). The mean plasma creatinine level in the females was 84.17 ± 54.73 μmol/l. In the diabetic population, there was a positive correlation between age and plasma creatinine level, (r=0.375, p=0.029). In the female diabetics, there was a positive correlation between fasting blood sugar (FBS) and the measured metabolic end products (r>0.5, p<0.05), a positive correlation between body mass index (BMI) and uric acid (r=0.576, p=0.005) and a positive correlation between BMI and FBS (r= 0.625, p= 0.030). Our results on the parameters measured; show that the diabetic population was experiencing mild kidney dysfunction, compared to non-diabetic controls.

  12. Mass spectra and ionization temperatures in an argon-nitrogen inductively coupled plasma

    International Nuclear Information System (INIS)

    Houk, R.S.; Montaser, A.; Fassel, V.A.

    1983-01-01

    Positive ions were extracted from the axial channel of an inductively coupled plasma (ICP) in which the outer gas flow was Ar, N 2 , or a mixture of Ar and N 2 . Addition of N 2 to the outer gas decreases the electron number density (n/sub e/) in the axial channel. Ar +2 , O 2 + , and ArH + react with N-containing species in the plasma and/or during the ion extraction process. Ar + remains abundant even if there is no Ar in the outer gas, which indicates the probable occurrence of charge transfer reactions between N 2 + and Ar. The present work corroborates two general concepts upon which several theories of theorigin of suprathermal ionization in ICPs are based: (a) species are physically transported from the induction region to the axial channel; and (b) these species may react with a ionize neutral species in the axial channel. Ionization temperatures (T/sub ion/) measured from the ratio Cd + /I + were 5750 to 6700 K for a N 2 outer flow ICP a forward power of 1.2 kW. This T/sub ion/ range is significantly below that obtained for an Ar outer gas ICP under otherwise similar operating parameters

  13. National Urea Cycle Disorders Foundation

    Science.gov (United States)

    ... urea cycle disorders. Donate Now To End Urea Cycle Disorders © 2005-2017 NUCDF. All rights reserved. This site may be freely linked to but not copied or duplicated in any fashion without the Foundation's consent. Make A Donation in ...

  14. Effect of Low-Pressure Nitrogen DC Plasma Treatment on the Surface Properties of Biaxially Oriented Polypropylene, Poly (Methyl Methacrylate) and Polyvinyl Chloride Films

    International Nuclear Information System (INIS)

    Mortazavi, S. Hamideh; Ghoranneviss, Mahmood; Pilehvar, Soheil; Esmaeili, Sina; Zargham, Shamim; Hashemi, S. Ebrahim; Jodat, Hamzeh

    2013-01-01

    In this study, commercial biaxially oriented polypropylene (BOPP), polyvinyl chloride (PVC) and poly (methyl methacrylate) (PMMA) films were treated with nitrogen plasma over different exposure times in a Pyrex tube surrounded by a DC variable magnetic field. The chemical changes that appeared on the surface of the samples were investigated using Fourier transform infrared (FT-IR) spectroscopy and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy after treatment for 2 min, 4 min and 6 min in a nitrogen plasma chamber. Effects of the plasma treatment on the surface topographies and contact angles of the untreated and plasma treated films were also analyzed by atomic force microscopy (AFM) and a contact angle measuring system. The results show that the plasma treated films become more hydrophilic with an enhanced wettability due to the formation of some new polar groups on the surface of the treated films. Moreover, at higher exposure times, the total surface energy in all treated films increased while a reduction in contact angle occurred. The behavior of surface roughness in each sample was completely different at higher exposure times. (plasma technology)

  15. The effect of nitrogen and oxygen plasma on the wear properties and adhesion strength of the diamond-like carbon film coated on PTFE

    International Nuclear Information System (INIS)

    Ozeki, K.; Hirakuri, K.K.

    2008-01-01

    Diamond-like carbon (DLC) films were deposited on polytetrafluoroethylene (PTFE) using a radiofrequency plasma chemical vapour deposition method. Prior to DLC coating, the PTFE substrates were modified with O 2 and N 2 plasma to enhance the adhesion strength of the DLC film to the substrate. The effect of the plasma pre-treatment on the chemical composition and the surface energy of the plasma pre-treated PTFE surface was investigated by X-ray photoelectron spectroscopy (XPS) and static water contact angle measurement, respectively. A pull-out test and a ball-on-disc test were carried out to evaluate the adhesion strength and the wear properties of the DLC-coated PTFE. In the N 2 plasma pre-treatment, the XPS result indicated that defluorination and the nitrogen grafting occurred on the plasma pre-treated PTFE surface, and the water contact angle decreased with increasing the plasma pre-treatment time. In the O 2 plasma pre-treatment, no grafting of the oxygen occurred, and the water contact angle slightly increased with the treatment time. In the pull-out test, the adhesion strength of the DLC film to the PTFE substrate was improved with the plasma pre-treatment to the PTFE substrate, and N 2 plasma pre-treatment was more effective than the O 2 plasma pre-treatment. In the ball-on-disc test, the DLC film with the N 2 plasma pre-treatment showed good wear resistance, compared with that with O 2 plasma pre-treatment

  16. Study on utilization of nitrogen and phosphorus from compound fertilizer by rice using isotopes 15N and 32P

    International Nuclear Information System (INIS)

    Wen Xianfang; Li Dongyang; Zhang Xizhong; Chen Yizhu

    1986-01-01

    This paper describes the application of urea plus ordinary superphospate (OSP) which gave higher grains yield than by application of compound fertilizer UPA (ureaplus compound ammonium phosphates). Isotopes tracer experiment showed that the utilizations of nitrogen fertilizer are: mixed urea and OSP > urea and OSP separately > urea > urea - ammonium phosphates. The utilizations of phosphorus by rice are: urea-ammomium phosphate > mixed urea and OSP > urea and OSP separately > OSP. It is shown that the A N -value of soil was significantly correlated with yield of rice grains

  17. Application of urea-15N in common bean (Phaseolus vulgaris, L.) CV. carioca

    International Nuclear Information System (INIS)

    Neptune, A.M.L.; Muraoka, T.

    1978-01-01

    A study was made in a Textural B Terra Roxa soil of medium fertility, by the use of different levels of Urea 15 N at seeding and at different stages of growth of common beans. Observations were made on the quantity of nitrogen uptaken by the crop, the efficiency of the plant in the utilization of the nitrogen fertilizer and yield. The application of urea, up to 120 kg N/ha, did not show a marked effect on yield, but the utilization of fertilizer nitrogen increased with the increase in nitrogen fertilizer levels. The up take of nitrogen by the bean crop was more efficient when the nitrogen fertilizer was applied before or at flowering stage rather than at seeding. The efficiency of nitrogen fertilizer utilization varied from 11.24% to 35.70%. There was no effect of inoculation on weight and number of nodules, with the rate of 120 kg N/ha [pt

  18. Investigations of nitrogen oxide plasmas: Fundamental chemistry and surface reactivity and monitoring student perceptions in a general chemistry recitation

    Science.gov (United States)

    Blechle, Joshua M.

    Part I of this dissertation focuses on investigations of nitrogen oxide plasma systems. With increasing concerns over the environmental presence of NxOy species, there is growing interest in utilizing plasma-assisted conversion techniques. Advances, however, have been limited because of the lack of knowledge regarding the fundamental chemistry of these plasma systems. Understanding the kinetics and thermodynamics of processes in these systems is vital to realizing their potential in a range of applications. Unraveling the complex chemical nature of these systems, however, presents numerous challenges. As such, this work serves as a foundational step in the diagnostics and assessment of these NxOy plasmas. The partitioning of energy within the plasma system is essential to unraveling these complications as it provides insight into both gas and surface reactivity. To obtain this information, techniques such as optical emission spectroscopy (OES), broadband absorption spectroscopy (BAS), and laser induced fluorescence (LIF) were utilized to determine species energetics (vibrational, rotational, translational temperatures). These temperature data provide mechanistic insight and establish the relationships between system parameters and energetic outcomes. Additionally, these data are also correlated to surface reactivity data collected with the Imaging of Radicals Interacting with Surfaces (IRIS) technique. IRIS data demonstrate the relationship between internal temperatures of radicals and their observed surface scatter coefficients (S), the latter of which is directly related to surface reactivity (R) [R = 1-S]. Furthermore, time-resolved (TR) spectroscopic techniques, specifically TR-OES, revealed kinetic trends in NO and N2 formation from a range of precursors (NO, N2O, N2/O2). By examining the rate constants associated with the generation and destruction of various plasma species we can investigate possible mechanistic implications. All told, such data provides

  19. Isotope studies on the comparative efficiency of nitrogenous sources

    Energy Technology Data Exchange (ETDEWEB)

    Dev, G; Rennie, D A [Saskatchewan Univ., Saskatoon (Canada). Dept. of Soil Science

    1979-03-01

    In a growth chamber experiment with /sup 15/N-labelled potassium nitrate, ammonium sulphate and urea at 75 and 150kg nitrogen/ha and ammonium nitrate at 150kg nitrogen/ha, nitrogen application produced significant responses of dry matter yield and total nitrogen uptake by shoot and root of barley in chernozemic dark brown Elstow silt loam and deep black Hoey clay soil. Total nitrogen removal per pot and isotope-derived criteria, viz. percentage nitrogen derived from fertilizer, 'A' value and percentage fertilizer nitrogen utilization, indicated that potassium nitrate was the most efficient and urea the least.

  20. Study of a recombination X-ray laser scheme in a H-like nitrogen plasma created by optical field induced ionization

    International Nuclear Information System (INIS)

    Hulin, S.

    2001-01-01

    Thanks to their high brightness and short wavelength, X ray lasers are interesting diagnostics in many experiments because they can efficiently probe dense plasmas. Furthermore their mono-chromaticity and collimation make them interesting tools in plasma physics but also in many biology or chemistry experiments. The effective use of this diagnostic is mainly depending on its dimensions and cost. For this reason, research on X ray laser is now focused on the reduction of cost and the realization of table-top facilities. One of these research axis, based on the optical field induced ionization (OFI) of the plasma, is presented in this work. An ultra-short (60 fs) high-brightness (10 19 W/cm 2 ) Ti:Sapphire (790 nm) laser is focused into a nitrogen pulsed gas jet. A dense (10 20 cm -3 ) plasma of fully stripped nitrogen is created by the way. During the fast recombination of the plasma some population inversions between levels of principal quantum number 2 and 1 (2.4 nm) and 3 and 2 (13.4 nm) can occur depending on the plasma parameters. The creation of the plasma by OFI, laser-plasma interaction dominated by relativistic self-focusing, and recombination dynamics are studied by numerical simulations on one hand and experiments on the other hand. Temperature measurements and numerical simulations show a strong heating, destructive for the laser scheme, which can be explained by Raman instability growing. Nevertheless plasma X ray emission in the 2-20 nm range show a strong increase with the electronic density of the 13.4 nm line intensity. This behavior is consistent with a laser effect but is not detected on the 2.4 nm transition line. (author)

  1. Deposits from Creams Containing 20% (w/w) Urea and Suppression of Crystallization (Part 2): Novel Analytical Methods of Urea Accumulated in the Stratum Corneum by Tape stripping and Colorimetry.

    Science.gov (United States)

    Goto, Norio; Morita, Yutaka; Terada, Katsuhide

    2016-01-01

    The transfer of urea from a urea formulation to the stratum corneum varies with the formulation base and form, and impacts the formulation's therapeutic effect. Consequently, determining the amount of urea transferred is essential for developing efficient formulations. This study assessed a simple method for measuring the amount of urea accumulated in the stratum corneum. Conventional methods rely on labeling urea used in the formulation with radiocarbon ((14)C) or other radioactive isotopes (RIs), retrieving the transferred urea from the stratum corneum by tape stripping, then quantitating the urea. The handling and use of RIs, however, is subject to legal regulation and can only be performed in sanctioned facilities, so methods employing RIs are neither simple nor convenient. We therefore developed a non-radiolabel method "tape stripping-colorimetry (T-C)" that combines tape stripping with colorimetry (urease-glutamate dehydrogenase (GLDH)) for the quantitative measurement of urea. Urea in the stratum corneum is collected by tape stripping and measured using urease-GLDH, which is commonly used to measure urea nitrogen in blood tests. The results indicate that accurate urea measurement by the T-C method requires the application of 1400 mg (on hairless rats) of a 20% urea solution on a 50 cm(2) (5×10 cm) area. Further, we determined the amount of urea accumulated in the stratum corneum using formulations with different urea concentrations, and the time course of urea accumulation from formulations differing in the rate of urea crystallization. We demonstrate that the T-C method is simple and convenient, with no need for (14)C or other RIs.

  2. Alkaline tide and nitrogen conservation after feeding in an elasmobranch (Squalus acanthias).

    Science.gov (United States)

    Wood, Chris M; Kajimura, Makiko; Mommsen, Thomas P; Walsh, Patrick J

    2005-07-01

    We investigated the consequences of feeding for acid-base balance, nitrogen excretion, blood metabolites and osmoregulation in the Pacific spiny dogfish. Sharks that had been starved for 7 days were surgically fitted with indwelling stomach tubes for gastric feeding and blood catheters for repetitive blood sampling and were confined in chambers, allowing measurement of ammonia-N and urea-N fluxes. The experimental meal infused via the stomach tube consisted of flatfish muscle (2% of body mass) suspended in saline (4% of body mass total volume). Control animals received only saline (4% of body mass). Feeding resulted in a marked rise in both arterial and venous pH and HCO3- concentrations at 3-9 h after the meal, with attenuation by 17 h. Venous P(O2) also fell. As there were negligible changes in P(CO2), the response was interpreted as an alkaline tide without respiratory compensation, associated with elevated gastric acid secretion. Urea-N excretion, which comprised >90% of the total, was unaffected, while ammonia-N excretion was very slightly elevated, amounting to <3% of the total-N in the meal over 45 h. Plasma ammonia-N rose slightly. Plasma urea-N, TMAO-N and glucose concentrations remained unchanged, while free amino acid and beta-hydroxybutyrate levels exhibited modest declines. Plasma osmolality was persistently elevated after the meal relative to controls, partially explained by a significant rise in plasma Cl-. This marked post-prandial conservation of nitrogen is interpreted as reflecting the needs for urea synthesis for osmoregulation and protein growth in animals that are severely N-limited due to their sporadic and opportunistic feeding lifestyle in nature.

  3. Plasma coatings of nitrogen polymers on metal prostheses of the circulatory system

    International Nuclear Information System (INIS)

    Gomez J, L. M.

    2016-01-01

    This work has a study about the synthesis of poly aniline, poly allylamine and poly pyrrole doped with iodine onto metallic surfaces similar to stents for the circulatory system. Ar, water and hydrogen peroxide plasmas were used for eroding, conditioning and synthesizing polymers that potentially reduce some rejection reactions when stents are implanted in the human body. Stents are small metallic meshes that applied inside collapsed arteries or veins enlarge the diameter and restore the blood flow, however the metallic surfaces usually cause rejection reactions that obstruct the veins again. To give solutions to this problem, in this work is studied the synthesis of biocompatible polymer coatings on the stents that resist the blood flow forming a biocompatible interface between metal and blood. The metallic substrates were eroded and chemically prepared with Ar, H_2O and/or H_2O_2 glow discharges on which the polymers were synthesized by plasma. The coatings were morphologically characterized by optical, scanning electron and atomic force microscopy, the chemical structure was studied by infrared and photoelectron X-ray spectroscopy. The hydrophilicity was studied measuring the advance static contact angle and the adhesion was evaluated indirectly with scanning electron microscopy after two months submerged in buffered phosphate solutions. The results indicate that the polymers grew following the superficial morphology; that the conditioning with Ar ions erode the substrates and that the conditioning with H_2O or H_2O_2 erodes and activates the surface generating oxygen bridges which help in the polymer-metal adhesion. The chemical structure of the polymeric coatings contain crosslinked structures that correspond to links between monomers with the participation of all atoms, states that suggest monomer fragmentation and oxidation and states that indicate oxygen bridges in the polymers. The coatings had contact angles close to 90 degrees where is located the line

  4. Studies on the nitrogen metabolism of the large intestine of ruminants. 2

    International Nuclear Information System (INIS)

    Sommer, A.; Ceresnakova, Z.; Szakacs, J.; Chrastinova, L.; Bergner, H.; Simon, O.

    1986-01-01

    3 bulls with body weights of 201, 168 and 190 kg, were equipped with a ileo-cecal re-entrant cannula and with catheters in the jugular veins on both sides. The pelleted ration was composed of straw 70-72%, cereals 10%, molasses 12-41% ammoniumhydrogencarbonate 3%, urea 2% and mineral mixture 1%. During a preliminary period ileal digesta were collected, deep-freezed and stored. During the main experiment 15 N-urea was infused intravenously for 24 hours. In this period and during the following 6 hours outflowing ileal digesta were collected quantitatively. At the same time precollected, unlabelled digesta together with a supplement of partly hydrolyzed straw meal were reintroduced into the cecal part of the cannula. Plasma urea N, urinary N as well as several N fractions of feces and digesta were analyzed for 15 N abundance. A urea flux rate of 27.9 +- 3.4 μmol per minute per kg/sup 0.75/ was estimated. It was calculated that 52% of this amount of urea was transfered into the digestive tract. In both, digesta and feces NH 3 nitrogen was highest 15 N-labelled indicating a direct urea entry and degradation in both segments of the digestive tract. The amounts of 15 N excess found during the period of digesta replacement were in feces 0.25 and in ileal digesta 4.02% of the infused 15 N. Although the microbial utilization of endogenous urea N was generally low in the large intestine there was a clear stimulation of this process due to the additional supply of the large intestine with a fermentable source. (author)

  5. Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements

    International Nuclear Information System (INIS)

    Niemi, K.; O'Connell, D.; Gans, T.; Oliveira, N. de; Joyeux, D.; Nahon, L.; Booth, J. P.

    2013-01-01

    Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N 2 /O 2 (4:1) admixtures. A maximum in the O-atom concentration of (9.1 ± 0.7)×10 20 m −3 was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 ± 0.4)×10 19 m −3 at 0.1 vol. %

  6. Sequential effect of phages and cold nitrogen plasma against Escherichia coli O157:H7 biofilms on different vegetables.

    Science.gov (United States)

    Cui, Haiying; Bai, Mei; Yuan, Lu; Surendhiran, Duraiarasan; Lin, Lin

    2018-03-02

    Escherichia coli O157:H7 (E. coli O157:H7) is one of the most common pathogens in fresh vegetables and fruits, and most of the diseases produced by E. coli O157:H7 are associated with biofilms. Cold nitrogen plasma (CNP) is a cold sterilization technique which has no residue. However to completely eliminate the biofilm on the surface of vegetables the processing power and time of CNP have to be enhanced, which will impact on the quality of fruits and vegetables. Thus the sequential treatment of CNP and phage techniques was engineered in this study. Compared to treatment performed separately, sequential treatment not only had more mild treatment conditions as 400W CNP treatment for 2min and 5% phage treatment for 30min, but also exhibited more remarkable effect on eradicating E. coli O157:H7 biofilms in vitro and on vegetables. The population of E. coli O157:H7 was approximately reduced by 2logCFU/cm 2 after individual treatment of 5% phages for 30min or 500W CNP for 3min. While the sequential treatment of CNP (400W, 2min) and phages (5%, 30min) reduced the E. coli O157:H7 viable count in biofilm by 5.71logCFU/cm 2 . Therefore, the sequential treatment holds a great promise to improve the current treatment systems of bacterial contamination on different vegetable surfaces. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. The effect of CP concentration in the diet on urea kinetics and microbial usage of recycled urea in cattle: a meta-analysis.

    Science.gov (United States)

    Batista, E D; Detmann, E; Valadares Filho, S C; Titgemeyer, E C; Valadares, R F D

    2017-08-01

    In ruminants, urea recycling is considered an evolutionary advantage. The amount of urea recycled mainly depends of the nitrogen (N) intake and the amount of organic matter (OM) digested in the rumen. Because recycled N contributes to meeting microbial N requirements, accurate estimates of urea recycling can improve the understanding of efficiency of N utilization and N losses to the environment. The objective of this study was to evaluate urea kinetics and microbial usage of recycled urea N in ruminants using a meta-analytical approach. Treatment mean values were compiled from 25 studies with ruminants (beef cattle, dairy cows and sheep) which were published from 2001 to 2016, totalling 107 treatment means. The data set was analyzed according to meta-analysis techniques using linear or non-linear mixed models, taking into account the random variations among experiments. Urea N synthesized in the liver (UER) and urea N recycled to the gut (GER) linearly increased (PCP concentration and the ratio of CP to digestible OM (CP:DOM). Maximum curvature analyses identified 17% dietary CP as the point where there was a prominent increase in hepatic synthesis of urea N, likely due to an excess of dietary N leading to greater ammonia absorption. The GER:UER decreased with increasing dietary CP concentration (PCP⩾19%, GER:UER reached near minimal values. The fraction of UER eliminated as urinary urea N and the contribution of urea N to total urinary N were positively associated with dietary CP (PCP was 17%. The fractions of GER excreted in the feces and utilized for anabolism decreased, whereas the fraction of GER returned to the ornithine cycle increased with dietary CP concentration (PCP and CP:DOM increased (PCP/kg DOM. The models obtained in this study contribute to the knowledge on N utilization, and they could be used in feeding models to predict urea recycling and thus to improve formulation of diets to reduce N losses that contribute to air and water pollution.

  8. Control over the morphology of AlN during molecular beam epitaxy with the plasma activation of nitrogen on Si (111) substrates

    International Nuclear Information System (INIS)

    Mizerov, A. M.; Kladko, P. N.; Nikitina, E. V.; Egorov, A. Yu.

    2015-01-01

    The results of studies of the growth kinetics of AlN layers during molecular beam epitaxy with the plasma activation of nitrogen using Si (111) substrates are presented. The possibility of the growth of individual AlN/Si (111) nanocolumns using growth conditions with enrichment of the surface with metal near the formation mode of Al drops, at a substrate temperature close to maximal, during molecular beam epitaxy with the plasma activation of nitrogen (T s ≈ 850°C) is shown. The possibility of growing smooth AlN layers on a nanocolumnar AlN/Si (111) buffer with the use of T s ≈ 750°C and growth conditions providing enrichment with metal is shown

  9. Control over the morphology of AlN during molecular beam epitaxy with the plasma activation of nitrogen on Si (111) substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mizerov, A. M., E-mail: mizerov@beam.ioffe.ru; Kladko, P. N.; Nikitina, E. V.; Egorov, A. Yu. [Russian Academy of Sciences, St. Petersburg Academic University-Nanotechnology Research and Education Centre (Russian Federation)

    2015-02-15

    The results of studies of the growth kinetics of AlN layers during molecular beam epitaxy with the plasma activation of nitrogen using Si (111) substrates are presented. The possibility of the growth of individual AlN/Si (111) nanocolumns using growth conditions with enrichment of the surface with metal near the formation mode of Al drops, at a substrate temperature close to maximal, during molecular beam epitaxy with the plasma activation of nitrogen (T{sub s} ≈ 850°C) is shown. The possibility of growing smooth AlN layers on a nanocolumnar AlN/Si (111) buffer with the use of T{sub s} ≈ 750°C and growth conditions providing enrichment with metal is shown.

  10. comparative studies on the mineralization of furfural urea and urea

    African Journals Online (AJOL)

    DR. AMINU

    2013-12-02

    Dec 2, 2013 ... In this research, laboratory studies were conducted to evaluate the effects of furfural urea as a slow release N ... regarding groundwater pollution ( Myrold, 2008). The ... The plastic pots containing the treated soil sample and.

  11. Oxygen reduction reaction properties of nitrogen-incorporated nanographenes synthesized using in-liquid plasma from mixture of ethanol and iron phthalocyanine

    Science.gov (United States)

    Amano, Tomoki; Kondo, Hiroki; Takeda, Keigo; Ishikawa, Kenji; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

    2018-04-01

    Nanographenes were synthesized using in-liquid plasma from a mixture of iron phthalocyanine and ethanol. In a previous study, micrometer-scale flakes with nitrogen incorporation were obtained. A nonprecious metal catalytic activity was observed with 3.13 electrons in an oxygen reduction reaction under an acidic solute condition. Large-surface-area, high-graphene-crystallinity, and iron-carbon-bonding sites were found owing to a high catalytic activity in Fe-N/nanographene.

  12. Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

    Science.gov (United States)

    Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan; Bresnahan, Rich C.

    2015-10-01

    Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 1016 to 3.8 × 1019 cm-3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1-2 × 1015 cm-3. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the dramatically enhanced growth rates demonstrate

  13. Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan, E-mail: alan.doolittle@ece.gatech.edu [Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Bresnahan, Rich C. [Veeco Instruments, St. Paul, Minnesota 55127 (United States)

    2015-10-21

    Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N{sub 2} while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N{sub 2} and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10{sup 16} to 3.8 × 10{sup 19} cm{sup −3} were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10{sup 15} cm{sup −3}. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be

  14. Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

    International Nuclear Information System (INIS)

    Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan; Bresnahan, Rich C.

    2015-01-01

    Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N 2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N 2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10 16 to 3.8 × 10 19 cm −3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10 15 cm −3 . The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the

  15. Understanding Strategy of Nitrate and Urea Assimilation in a Chinese Strain of Aureococcus anophagefferens through RNA-Seq Analysis

    Science.gov (United States)

    Dong, Hong-Po; Huang, Kai-Xuan; Wang, Hua-Long; Lu, Song-Hui; Cen, Jing-Yi; Dong, Yue-Lei

    2014-01-01

    Aureococcus anophagefferens is a harmful alga that dominates plankton communities during brown tides in North America, Africa, and Asia. Here, RNA-seq technology was used to profile the transcriptome of a Chinese strain of A. anophagefferens that was grown on urea, nitrate, and a mixture of urea and nitrate, and that was under N-replete, limited and recovery conditions to understand the molecular mechanisms that underlie nitrate and urea utilization. The number of differentially expressed genes between urea-grown and mixture N-grown cells were much less than those between urea-grown and nitrate-grown cells. Compared with nitrate-grown cells, mixture N-grown cells contained much lower levels of transcripts encoding proteins that are involved in nitrate transport and assimilation. Together with profiles of nutrient changes in media, these results suggest that A. anophagefferens primarily feeds on urea instead of nitrate when urea and nitrate co-exist. Furthermore, we noted that transcripts upregulated by nitrate and N-limitation included those encoding proteins involved in amino acid and nucleotide transport, degradation of amides and cyanates, and nitrate assimilation pathway. The data suggest that A. anophagefferens possesses an ability to utilize a variety of dissolved organic nitrogen. Moreover, transcripts for synthesis of proteins, glutamate-derived amino acids, spermines and sterols were upregulated by urea. Transcripts encoding key enzymes that are involved in the ornithine-urea and TCA cycles were differentially regulated by urea and nitrogen concentration, which suggests that the OUC may be linked to the TCA cycle and involved in reallocation of intracellular carbon and nitrogen. These genes regulated by urea may be crucial for the rapid proliferation of A. anophagefferens when urea is provided as the N source. PMID:25338000

  16. Synthesis of 13N and/or 11C single or doubly labelled urea

    International Nuclear Information System (INIS)

    Emran, A.M.

    1989-01-01

    Utilization of nitrogen by plants encounters two important problems which are denitrification and deficiency or inactivation of certain enzyme. In the first process the fertilizer is affected by certain bacteria to produce nitrogen or its oxides which cannot be utilized by plants. In the second process, transformation of urea nitrogen into forms usable by plants depends on abundance and activity of the enzyme urease. Study of inorganic nitrogen transport has been underway using 13 N-nitrate as a tracer. Behavior of organic nitrogen can be studied using labelled urea. [ 13 N] and/or [ 11 C] single or doubly labelled urea are good tracers for this purpose. Reaction of trace amounts of potassium cyanate with 13 N-ammonium sulfate produced 13 N-ammonium cyanate which was thermally transformed into [ 13 N]-urea with no added carrier. Similarly, [ 11 C]-potassium cyanate reacted with 13 N-ammonium sulfate to produce 13 N/ 11 C-doubly labelled urea. Thin layer and high performance liquid chromatography were used to identify the products and determine the yields

  17. Blood ammonia and glutamine as predictors of hyperammonemic crises in patients with urea cycle disorder.

    Science.gov (United States)

    Lee, Brendan; Diaz, George A; Rhead, William; Lichter-Konecki, Uta; Feigenbaum, Annette; Berry, Susan A; Le Mons, Cindy; Bartley, James A; Longo, Nicola; Nagamani, Sandesh C; Berquist, William; Gallagher, Renata; Bartholomew, Dennis; Harding, Cary O; Korson, Mark S; McCandless, Shawn E; Smith, Wendy; Cederbaum, Stephen; Wong, Derek; Merritt, J Lawrence; Schulze, Andreas; Vockley, Jerry; Vockley, Gerard; Kronn, David; Zori, Roberto; Summar, Marshall; Milikien, Douglas A; Marino, Miguel; Coakley, Dion F; Mokhtarani, Masoud; Scharschmidt, Bruce F

    2015-07-01

    The aim of this study was to examine predictors of ammonia exposure and hyperammonemic crises in patients with urea cycle disorders. The relationships between fasting ammonia, daily ammonia exposure, and hyperammonemic crises were analyzed in >100 patients with urea cycle disorders. Fasting ammonia correlated strongly with daily ammonia exposure (r = 0.764; P 200% (P urea cycle disorder subtype, dietary protein intake, or blood urea nitrogen. Fasting glutamine correlated weakly with daily ammonia exposure assessed as 24-hour area under the curve and was not a significant predictor of hyperammonemic crisis. Fasting ammonia correlates strongly and positively with daily ammonia exposure and with the risk and rate of hyperammonemic crises, suggesting that patients with urea cycle disorder may benefit from tight ammonia control.

  18. Effects of polymer coated slow-release urea on ruminal fermentation and nutrient total tract digestion of beef steers

    Directory of Open Access Journals (Sweden)

    Rodrigo Gardinal

    2016-02-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the effects of polymer coated slow-release urea (SRU in high-forage diets of beef steers on nutrient intake and digestibility, ruminal fermentation, microbial protein synthesis, and energy balance. Eight 24-mo-old rumen-fistulated castrated Nellore steers (average body weight = 418.0±40.0 kg were used in a replicated 4 × 4 Latin square design. Animals were randomly distributed to receive one of the following diets: no urea inclusion; 1.0% inclusion of feed grade urea in the diet (dry matter [DM] basis; 1.0% inclusion of slow-release urea 1 in the diet (DM basis; and 1.0% inclusion of slow-release urea 2 in the diet (DM basis. Slow-release urea 2 had a similar composition to that of slow-release urea 1 and differed in that it contained 2.95% sulfur. A high-forage diet was provided (75% of total DM and corn silage was used as the forage source. Diets with urea had increased crude protein (CP intake, and CP and total digestible nutrients total tract digestion. Urea sources increased ruminal concentrations of ammonia nitrogen and acetate, and decreased butyrate concentrations. The polymer coated urea did not alter ruminal fermentation when compared with feed grade urea. Diets did not affect the energy balance of steers. Feed grade urea presented greater microbial protein synthesis than polymer coated slow-release urea. The partial replacement of soybean meal by 1% slow-release urea in a diet with 75% forage does not improve ruminal fermentation and microbial protein synthesis, and shows similar results as feeding feed grade urea to beef steers.

  19. Modulation of cadmium-induced phytotoxicity in Cabomba caroliniana by urea involves photosynthetic metabolism and antioxidant status.

    Science.gov (United States)

    Huang, Wenmin; Shao, Hui; Zhou, Sining; Zhou, Qin; Li, Wei; Xing, Wei

    2017-10-01

    Urea is a widespread organic pollutant, which can be a nitrogen source, playing different roles in the growth of submerged macrophytes depending on concentrations, while high cadmium (Cd) concentrations are often toxic to macrophytes. In order to evaluate the combined effect of urea and Cd on a submerged macrophyte, Cabomba caroliniana, the morphological and physiological responses of C. caroliniana in the presence of urea and Cd were studied. The results showed that high concentrations of urea (400mgL -1 ) and Cd (500µmolL -1 ) had negative effects on C. caroliniana. There were strong visible symptoms of toxicity after 4 days of exposure under Cd-alone, 400mgL -1 urea, and Cd+400mgL -1 urea treatments. In addition, 400mgL -1 urea and Cd had adverse effects on C. caroliniana's pigment system. Significant losses in chlorophyll fluorescence and photosynthetic rates, as well as Rubisco activity were also observed under Cd-alone, 400mgL -1 urea, and Cd+400mgL -1 urea treatments. 400mgL -1 urea markedly enhanced Cd toxicity in C. caroliniana, reflected by a sharp decrease in photosynthetic activity and more visible toxicity symptoms. The results of thiobarbituric acid reactive substances (TBARS) pointed to extreme oxidative stress in C. caroliniana induced under Cd or 400mgL -1 urea exposure. Exogenous ascorbate (AsA) protected C. caroliniana from adverse damage in 400mgL -1 urea, which further corroborated the oxidative stress claim under 400mgL -1 urea. However, results also demonstrated that lower urea concentration (10mgL -1 ) alleviated Cd-induced phytotoxicity by stimulating chlorophyll synthesis and photosynthetic activity, as well as activating the activity of catalase (CAT) and glutathione-S-transferase (GST), which may explain the alleviating effect of urea on C. caroliniana under Cd stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Production of granules of urea, urea-ammonium sulphate and urea-potassium chloride enriched with 15N

    International Nuclear Information System (INIS)

    Bendassolli, J.A.

    1991-01-01

    Using a pearling tower it was possible to produce granulated urea, and granulated mixtures of ammonium sulphate and urea, potassium chloride and urea, Labelled in 15 N. Granulated urea with 1, 2, 3 and 4 mm of diameter was obtained using a system with a heating controller. A low concentration of biuret was observed in the granules produced ( 15 N-Labelled ( 15 NH 4' 15 NH 2 ) with variable proportion of ammonium sulphate and urea. (author)

  1. PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION : DELETION OF INDIVIDUAL AMINO ACIDS FROM GROWTH MIXTURE OF TEN ESSENTIAL AMINO ACIDS. SIGNIFICANT CHANGES IN URINARY NITROGEN.

    Science.gov (United States)

    Robscheit-Robbins, F S; Miller, L L; Whipple, G H

    1947-02-28

    Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive

  2. 21 CFR 862.1515 - Nitrogen (amino-nitrogen) test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nitrogen (amino-nitrogen) test system. 862.1515... Systems § 862.1515 Nitrogen (amino-nitrogen) test system. (a) Identification. A nitrogen (amino-nitrogen) test system is a device intended to measure amino acid nitrogen levels in serum, plasma, and urine...

  3. /sup 15/N study on dietary urea utility in young pigs fed with a low protein diet

    Energy Technology Data Exchange (ETDEWEB)

    Niiyama, M; Kagota, K; Iwase, T; Namioka, S [Hokkaido Univ., Sapporo (Japan)

    1978-10-01

    To investigate effect of a low protein diet on urea utilization, a tracer study was conducted with /sup 15/N-urea on pigs fed a low protein diet (DCP 5.7%) with 2% urea (group B), and on pigs fed and optimal protein diet (DCP 13.3%) with 2% urea (group A). /sup 15/N was incorporated into protein of liver, serum and muscle, which were obtained 8 days after the last administration of /sup 15/N-urea. The /sup 15/N incorporation rate into the tissue protein tended to be higher in group B than in group A. Approximately 70% of /sup 15/N, however, was excreted into urine within 48 hours in group B. A comparison was made on growth and urea level in blood and urine to evaluate efficacy of the administered urea on growth between group B pigs and pigs fed the same low protein diet without urea supplementation (group C). Since group B pigs always maintained a higher level of blood urea, they were considered to have had more ammonia nitrogen which was available for protein synthesis than group C animals. A similar amount of urea to ingested dose, however, was excessively eliminated in urine. The increased ammonia nitrogen by urea ingestion may be excreted in form of urinary urea in group B pigs. There was no difference in growth between group B and group C animals; therefore, poor efficacy of administered urea on growth may have resulted not only from its loss into urine in early stage after ingestion, but also to poor utility of ammonia for protein synthesis.

  4. A 15N study on dietary urea utility in young pigs fed with a low protein diet

    International Nuclear Information System (INIS)

    Niiyama, Masayoshi; Kagota, Katsumoto; Iwase, Toshio; Namioka, Shigeo

    1978-01-01

    To investigate effect of a low protein diet on urea utilization, a tracer study was conducted with 15 N-urea on pigs fed a low protein diet (DCP 5.7%) with 2% urea (group B), and on pigs fed and optimal protein diet (DCP 13.3%) with 2% urea (group A). 15 N was incorporated into protein of liver, serum and muscle, which were obtained 8 days after the last administration of 15 N-urea. The 15 N incorporation rate into the tissue protein tended to be higher in group B than in group A. Approximately 70% of 15 N, however, was excreted into urine within 48 hours in group B. A comparison was made on growth and urea level in blood and urine to evaluate efficacy of the administered urea on growth between group B pigs and pigs fed the same low protein diet without urea supplementation (group C). Since group B pigs always maintained a higher level of blood urea, they were considered to have had more ammonia nitrogen which was available for protein synthesis than group C animals. A similar amount of urea to ingested dose, however, was excessively eliminated in urine. The increased ammonia nitrogen by urea ingestion may be excreted in form of urinary urea in group B pigs. There was no difference in growth between group B and group C animals; therefore, poor efficacy of administered urea on growth may have resulted not only from its loss into urine in early stage after ingestion, but also to poor utility of ammonia for protein synthesis. (author)

  5. Foliar fertilization of sugarcane (Saccharum spp): absorption and translocation of 15-N-labeled urea

    International Nuclear Information System (INIS)

    Trivelin, P.C.O.; Carvalho, J.G. de; Silva, A.Q. da; Primavesi, A.C.P.A.; Camacho, E.; Eimori, I.E.; Guilherme, M.R.

    1988-01-01

    The absorption and translocation of foliar applied nitrogen as urea solution to sugar cane plants was evaluated. An experiment using the isotope dilution technique with 15 N labeled urea was carried out in green house condition. Seedlings of sugarcane variety IAC 53-150 were planted in pots with 5KG of top soil''latossolo vermelho amarelo, fase arenosa'' (Haplustox). (M.A.C.) [pt

  6. Pengaruh Suplementasi Baking Soda dalam Pakan terhadap Urea Darah dan Urea Susu Sapi Perah Laktasi

    Directory of Open Access Journals (Sweden)

    W. A. Harjanti

    2017-06-01

    Full Text Available The aim of the research was to assess the effect of suplementation of sodium bicarbonate in feed rations on the concentration of Blood Urea Nitrogen (BUN and Milk Urea Nitrogen (MUN of lactating dairy cattle. The materials used were 12 lactating Friesian Holstein cattle in the 1th lactation period and the month lactation of 5 and 6th. The experiment used a completely randomized design with 3 treatments and 4 replications. The experimental treatmens were basal ration (T0, and basal ration supplemented with 0,8 % (T0 and 1 % (T2 of sodium bicarbonate, on a dry matter (DM basis. The parameters determined were crude protein intake (CPI and the concentration of BUN and MUN. The data were analyzed using variance the F-test. The result showed that the CPI, and the concentration of BUN and MUN were not affected by the treatments. The CPI were 2.097,43 ; 2.079,19 and 2.053,17 g/d. The concentration of BUN were 14,04 ; 13,05 and 12,75 mg/dl, whereas the concentration of MUN were 12,43 ; 10,01 and 10,07 mg/dl for T0, T1 dan T2 respectively. Overall, 0,8 and 1% of sodium bicarbonate supplementations into feed ration was not found to significantly alter the quantity of crude protein intake and the concentration of BUN and MUN in lactating dairy cattle in the present study.

  7. Urea route to coat inorganic nanowires, carbon fibers and nanotubes by boron nitride

    International Nuclear Information System (INIS)

    Gomathi, A.; Ramya Harika, M.; Rao, C.N.R.

    2008-01-01

    A simple route involving urea as the nitrogen source has been employed to carry out boron nitride coating on carbon fibers, multi-walled carbon nanotubes and inorganic nanowires. The process involves heating the carbon fibers and nanotubes or inorganic nanowires in a mixture of H 3 BO 3 and urea, followed by a heat treatment at 1000 deg. C in a N 2 atmosphere. We have been able to characterize the BN coating by transmission electron microscopy as well as X-ray photoelectron spectroscopy. The urea decomposition route affords a simple method to coat boron nitride on one-dimensional nanostructures

  8. Urease inhibitor (NBPT and efficiency of single or split application of urea in wheat crop

    Directory of Open Access Journals (Sweden)

    Marcelo Curitiba Espindula

    2014-04-01

    Full Text Available NBPT (N-(n-butyl thiophosphoric triamide, a urease inhibitor, has been reported as one of the most promising compounds to maximize urea nitrogen use in agricultural systems. The objective of this study was to evaluate the performance of irrigated wheat fertilized with urea or urea + NBPT as single or split application. The experiment was conducted from June to October 2006 in Viçosa, MG, Brazil. The experimental design followed a 2×2 factorial scheme, in which urea or urea + NBPT were combined with two modes of application: full dose at sowing (60kg ha-1 or split (20kg ha-1 at sowing + 40kg ha-1 as topdressing at tillering, in randomized blocks with ten replications. The split application of nitrogen fertilization does not improve the yield wheat under used conditions. The use of urease inhibitor improves the grain yield of wheat crop when urea is applied in topdressing at tillering, but its use does not promote difference when urea is applied in the furrow at planting.

  9. Effect of method of N-application and modified urea on N-15 recovery by rice

    International Nuclear Information System (INIS)

    Soliman, S.M.; Abdelmonem, M.A.S.

    1995-01-01

    Rice is a very responsive crop to nitrogen fertilizer, but the efficiency of the applied N-fertilizer is low. Greenhouse experiment conducted to evaluate several methods to improve fertilizer efficiency and reduce N-losses in rice fields. N-15 labelled urea was applied to 10 kg soils in pots, urea was applied alone, with addition of two urease inhibitors (NBPT and HQ), with addition of nitrification inhibitor (DCD),or with the combination of both inhibitors. The fertilizers were applied either broadcast on soil surface or at depth of 8 cm below the surface. At maturity, plants were separated into grain and straw, dried and weighted. Soil and plant samples were analyzed for total N and N-15 excess. Both fertilizer placement and inhibitor application significantly increased straw and grain yield, as well as N-uptake. Nitrogen derived from fertilizer (%Ndff) was more than doubled, when urea was applied deep and in combination with inhibitors. Plant recovery of N-15 labelled urea ranged from 17% to 75% according to treatment. Regardless of inhibitors application, plant recovery was increased from 39% to 65% when urea was applied at depth of 8 cm. Approximately 2/3 of the applied urea (64%)was lost when urea was applied alone. Those losses were reduced down to 12% with deep placement and inhibitor application. The two management practices show significant effect on minimizing N-losses and increasing plant recovery. 1 fig., 3 tabs

  10. Effect of method of N-application and modified urea on N-15 recovery by rice

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, S M; Abdelmonem, M A.S. [Soil and Water Dept., Atomic Energy Auth., Cairo, (Egypt)

    1995-10-01

    Rice is a very responsive crop to nitrogen fertilizer, but the efficiency of the applied N-fertilizer is low. Greenhouse experiment conducted to evaluate several methods to improve fertilizer efficiency and reduce N-losses in rice fields. N-15 labelled urea was applied to 10 kg soils in pots, urea was applied alone, with addition of two urease inhibitors (NBPT and HQ), with addition of nitrification inhibitor (DCD),or with the combination of both inhibitors. The fertilizers were applied either broadcast on soil surface or at depth of 8 cm below the surface. At maturity, plants were separated into grain and straw, dried and weighted. Soil and plant samples were analyzed for total N and N-15 excess. Both fertilizer placement and inhibitor application significantly increased straw and grain yield, as well as N-uptake. Nitrogen derived from fertilizer (%Ndff) was more than doubled, when urea was applied deep and in combination with inhibitors. Plant recovery of N-15 labelled urea ranged from 17% to 75% according to treatment. Regardless of inhibitors application, plant recovery was increased from 39% to 65% when urea was applied at depth of 8 cm. Approximately 2/3 of the applied urea (64%)was lost when urea was applied alone. Those losses were reduced down to 12% with deep placement and inhibitor application. The two management practices show significant effect on minimizing N-losses and increasing plant recovery. 1 fig., 3 tabs.

  11. Urea-SCR Temperature Investigation for NOx Control of Diesel Engine

    Directory of Open Access Journals (Sweden)

    Asif Muhammad

    2015-01-01

    Full Text Available SCR (selective catalytic reduction system is continuously being analyzed by many researchers worldwide on various concerns due to the stringent nitrogen oxides (NOx emissions legislation for heavy-duty diesel engines. Urea-SCR includes AdBlue as urea source, which subsequently decomposes to NH3 (ammonia being the reducing agent. Reaction temperature is a key factor for the performance of urea-SCR system, as urea decomposition rate is sensitive to a specific temperature range. This particular study was directed to investigate the temperature of the SCR system in diesel engine with the objective to confirm that whether the appropriate temperature is attained for occurrence of urea based catalytic reduction or otherwise and how the system performs on the prescribed temperature range. Diesel engine fitted with urea-SCR exhaust system has been operated on European standard cycle for emission testing to monitor the temperature and corresponding nitrogen oxides (NOx values on specified points. Moreover, mathematical expressions for approximation of reaction temperature are also proposed which are derived by applying energy conservation principal and gas laws. Results of the investigation have shown that during the whole testing cycle system temperature has remained in the range where urea-SCR can take place with best optimum rate and the system performance on account of NOx reduction was exemplary as excellent NOx conversion rate is achieved. It has also been confirmed that selective catalytic reduction (SCR is the best suitable technology for automotive engine-out NOx control.

  12. Alcoholic Hepatitis Markedly Decreases the Capacity for Urea Synthesis.

    Directory of Open Access Journals (Sweden)

    Emilie Glavind

    Full Text Available Data on quantitative metabolic liver functions in the life-threatening disease alcoholic hepatitis are scarce. Urea synthesis is an essential metabolic liver function that plays a key regulatory role in nitrogen homeostasis. The urea synthesis capacity decreases in patients with compromised liver function, whereas it increases in patients with inflammation. Alcoholic hepatitis involves both mechanisms, but how these opposite effects are balanced remains unclear. Our aim was to investigate how alcoholic hepatitis affects the capacity for urea synthesis. We related these findings to another measure of metabolic liver function, the galactose elimination capacity (GEC, as well as to clinical disease severity.We included 20 patients with alcoholic hepatitis and 7 healthy controls. The urea synthesis capacity was quantified by the functional hepatic nitrogen clearance (FHNC, i.e., the slope of the linear relationship between the blood α-amino nitrogen concentration and urea nitrogen synthesis rate during alanine infusion. The GEC was determined using blood concentration decay curves after intravenous bolus injection of galactose. Clinical disease severity was assessed by the Glasgow Alcoholic Hepatitis Score and Model for End-Stage Liver Disease (MELD score.The FHNC was markedly decreased in the alcoholic hepatitis patients compared with the healthy controls (7.2±4.9 L/h vs. 37.4±6.8 L/h, P<0.01, and the largest decrease was observed in those with severe alcoholic hepatitis (4.9±3.6 L/h vs. 9.9±4.9 L/h, P<0.05. The GEC was less markedly reduced than the FHNC. A negative correlation was detected between the FHNC and MELD score (rho = -0.49, P<0.05.Alcoholic hepatitis markedly decreases the urea synthesis capacity. This decrease is associated with an increase in clinical disease severity. Thus, the metabolic failure in alcoholic hepatitis prevails such that the liver cannot adequately perform the metabolic up-regulation observed in other stressful

  13. Measurements of protein turnover in man with nitrogen-15

    International Nuclear Information System (INIS)

    Garlick, P.J.; Waterlow, J.C.

    1977-01-01

    Past and present methods of measuring total body protein turnover with 15 N-labelled compounds are reviewed, and a short assessment made of results achieved. Protein turnover in man was first measured by Sprinson and Rittenberg (1949) using 15 N glycine as tracer. The rate of turnover was calculated from the fraction of the dose excreted in urine in the days following a single oral dose of the isotope. In the following years a number of similar methods were devised but interest waned, perhaps because consistent changes in turnover rate under different conditions were not detected. A revival of interest came with the measurement of changes in protein turnover in malnourished and recovering children by Picou and Taylor-Roberts (1969). Nitrogen-15-glycine was infused and measurements were made of the abundance of 15 N in urinary urea, which reached a plateau in about 24 hours. Turnover rates were calculated from the proportion of the infused dose excreted in urea after the plateau had been reached. This method has also been used successfully on adults when the isotope has been given as three-hourly oral doses. In adults, however, plateau labelling in urea is not usually reached for two days. In our laboratory the use of urinary ammonia, which reaches a plateau more quickly than urea, has been examined. In addition, comparisons have been made between constant infusion and single dose of isotope. Halliday and McKeran (1975) infused 15 N-lysine and measured the 15 N abundance in the free lysine of plasma, which reached a plateau in about 12 hours. Turnover in the whole body and turnover of muscle proteins and of plasma albumin were estimated separately. These methods of measuring protein turnover with 15 N are described and results reviewed of the effects of food intake, nutritional status and age. (author)

  14. Quenching of the OH and nitrogen molecular emission by methane addition in an Ar capacitively coupled plasma to remove spectral interference in lead determination by atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Frentiu, T., E-mail: ftibi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Ponta, M., E-mail: mponta@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Mihaltan, A.I., E-mail: alinblaj2005@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Darvasi, E., E-mail: edarvasi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Frentiu, M., E-mail: frentiu.maria@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Cordos, E., E-mail: emilcordos@gmail.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania)

    2010-07-15

    A new method is proposed to remove the spectral interference on elements in atomic fluorescence spectrometry by quenching of the molecular emission of the OH radical (A{sup 2{Sigma}+} {yields} X{sup 2{Pi}}) and N{sub 2} second positive system (C{sup 3{Pi}}{sub u} {yields} B{sup 3{Sigma}}{sub g}) in the background spectrum of medium power Ar plasmas. The experiments were carried out in a radiofrequency capacitively coupled plasma (275 W, 27.12 MHz) by CH{sub 4} addition. The quenching is the result of the high affinity of OH radical for a hydrogen atom from the CH{sub 4} molecule and the collisions of the second kind between nitrogen excited molecules and CH{sub 4}, respectively. The decrease of the emission of N{sub 2} second positive system in the presence of CH{sub 4} is also the result of the deactivation of the metastable argon atoms that could excite the nitrogen molecules. For flow rates of 0.7 l min{sup -1} Ar with addition of 7.5 ml min{sup -1} CH{sub 4}, the molecular emission of OH and N{sub 2} was completely removed from the plasma jet spectrum at viewing heights above 60 mm. The molecular emission associated to CH and CH{sub 2} species was not observed in the emission spectrum of Ar/CH{sub 4} plasma in the ultraviolet range. The method was experimented for the determination of Pb at 283.31 nm by atomic fluorescence spectrometry with electrodeless discharge lamp and a multichannel microspectrometer. The detection limit was 35 ng ml{sup -1}, 2-3 times better than in atomic emission spectrometry using the same plasma source, and similar to that in hollow cathode lamp microwave plasma torch atomic fluorescence spectrometry.

  15. One-step argon/nitrogen binary plasma jet irradiation of Li4Ti5O12 for stable high-rate lithium ion battery anodes

    Science.gov (United States)

    Lan, Chun-Kai; Chuang, Shang-I.; Bao, Qi; Liao, Yen-Ting; Duh, Jenq-Gong

    2015-02-01

    Atmospheric pressure Ar/N2 binary plasma jet irradiation has been introduced into the manufacturing process of lithium ions batteries as a facile, green and scalable post-fabrication treatment approach, which enhanced significantly the high-rate anode performance of lithium titanate (Li4Ti5O12). Main emission lines in Ar/N2 plasma measured by optical emission spectroscopy reveal that the dominant excited high-energy species in Ar/N2 plasma are N2*, N2+, N∗ and Ar∗. Sufficient oxygen vacancies have been evidenced by high resolution X-ray photoelectron spectroscopy analysis and Raman spectra. Nitrogen doping has been achieved simultaneously by the surface reaction between pristine Li4Ti5O12 particles and chemically reactive plasma species such as N∗ and N2+. The variety of Li4Ti5O12 particles on the surface of electrodes after different plasma processing time has been examined by grazing incident X-Ray diffraction. Electrochemical impedance spectra (EIS) confirm that the Ar/N2 atmospheric plasma treatment facilitates Li+ ions diffusion and reduces the internal charge-transfer resistance. The as-prepared Li4Ti5O12 anodes exhibit a superior capacity (132 mAh g-1) and excellent stability with almost no capacity decay over 100 cycles under a high C rate (10C).

  16. Dry weight and N-uptake by rice plants fertilized with azolla and N-15 enriched urea

    International Nuclear Information System (INIS)

    Abdel-Monem, M.; Gadalla, A.M.; Abbady, Kh.

    1994-01-01

    Integrated soil fertility management is essential if soil productivity is to be sustained or improved. In view the recently high cost of N-fertilizers, interest was generated in using Azolla in rice fields. A greenhouse experiment was conducted to study the fate of N-15 labelled urea to rice with or without Azolla application, also to examine the effect of the soil moisture regime at the time of urea application on nitrogen recovery. The results indicated that addition of urea to dry soil gave more than 20% of the rice dry matter as compared to the urea application to wet soil which was also reflected on the N-uptake by the rice. Also N-15 recovery by plant was increased from 22% to 41% when urea was applied to wet and dry soil respectively. At the same time N-losses dropped from 62% to 29%. Addition of Azolla to rice provided rice with 63% of the nitrogen provided by urea, this may be attributed not only to N-fixation by Azolla, but also to its role in reducing the N-losses. Application of Azolla reduced the losses of applied nitrogen from 45.5% to 22.5%. Thus, integration between Azolla and urea is valuable in N-fixation as well as inhibiting nitrogen losses. 2 tabs

  17. Investigation of the influence of the content of plant crude protein in the ration on the utilisation of urea in dairy cattle. 5

    International Nuclear Information System (INIS)

    Motyl, T.; Barej, W.; Kulasek, G.; Bergner, H.; Goersch, R.

    1984-01-01

    The incorporation of urea- 15 N (given as an intraruminal drench or infusion) into plasma urea and protein of dairy cows fed isoenergetic rations with different levels of plant protein (9, 11, 12, 14, 15, and 17% in dry matter) was investigated. A nonlinear and asymptotic dependence between the plasma concentration of urea and protein level in the ration was stated. The availability of dietary urea- 15 N for plasma urea for 48 hours after administration was lowest in cows fed with low protein rations (9 and 11% of plant protein). On the contrary the highest incorporation of urea- 15 N into plasma protein of these animals was observed. The possible explanation of these results is presented. (author)

  18. Regulation of urea synthesis during the acute phase response in rats

    DEFF Research Database (Denmark)

    Thomsen, Karen Louise; Jessen, Niels; Buch Møller, Andreas

    2013-01-01

    The acute-phase response is a catabolic event involving increased waste of amino-nitrogen (N) via hepatic urea synthesis, despite an increased need for amino-N incorporation into acute-phase proteins. This study aimed to clarify the regulation of N elimination via urea during different phases...... of the tumor necrosis factor-α (TNF-α)-induced acute-phase response in rats. We used four methods to study the regulation of urea synthesis: We examined urea cycle enzyme mRNA levels in liver tissue, the hepatocyte urea cycle enzyme proteins, the in vivo capacity of urea-N synthesis (CUNS), and known humoral...... regulators of CUNS at 1, 3, 24, and 72 h after TNF-α injection (25 μg/kg iv rrTNF-α) in rats. Serum acute-phase proteins and their liver mRNA levels were also measured. The urea cycle enzyme mRNA levels acutely decreased and then gradually normalized, whereas the urea cycle enzyme proteins remained...

  19. KOMBINASI PENAMBAHAN UREA DAN EM-4 TERHADAP KUALITAS BOKASHI CAIR

    Directory of Open Access Journals (Sweden)

    Muhammad Dzulfikri Haidla

    2016-06-01

    Full Text Available The objectives of the study is to determine the effect of EM-4 and Urea addition on the liquid Bokashi quality of chicken manure. The field research was conducted at California Papaya Farm Pulau Sari, Pelaihari, and the nutrient levels of liquid Bokashi are then analyzed in the laboratory of PPLH Banjarbaru. The research was conducted from February to March 2015. It used Complete Randomized Design (CRD of factorial pattern 2 with three levels of treatment and three replications, the first factor is the addition of urea, consisting of three levels those are 0 g, 7.5 g, 15 g, the second factor is the addition of EM-4, consisting of three levels those are 0 ml, 25 ml, 50 ml, so that the number of trial units becomes 27 units. The variables measured are the Levels of Nitrogen (N, Phosphorous (P, Potassium (K, C-Organic, temperature, pH, color, smell, and texture. Quantitative observation data were analyzed using ANOVA and Duncan's Multiple Range Test (DMRT, while the qualitative observation data were analyzed using Kruskal-Wallis test. The results showed that the interaction between the addition of EM-4 and Urea were able to increase levels of nutrients N, P, K, C-Organic, and the temperature of the liquid Bokashi. Overall obtained treatment provision of EM-4 25 ml and 15 g Urea is the best treatment among other treatments. The addition of EM-4 was able to increase the levels of N, K, C-Organic and liquid Bokashi temperature, but it is unable to increase levels of the element P. Giving Urea can increase the levels of nutrients N, P, K, C-Organic, and the temperature of the liquid Bokashi. In observation of the organoleptic treatment with the addition of EM-4 and Urea, it tends to produce materials with better color, smell, and texture than the control treatment.

  20. Influence of temperature on properties of nitrogen plasma source ion implantation (N-PSII) of Ti6A14V alloy

    CERN Document Server

    Geng Man; Zhao Qing

    2001-01-01

    Specimens of Ti6Al4V alloy were implanted with nitrogen plasma source ion implantation (N-PSII) at temperatures between 100 degree C and 600 degree C to a ion dose of 4 x 10 sup 1 sup 7 cm sup - sup 2. Auger Electron Spectroscopy (AES) was used to determine the nitrogen concentration depth profiles. Microhardness measurements and pin-on-disk wear test were performed to evaluate the improvements of the surface modification. Glancing angle X-ray diffraction (XRD) was employed to determine the phases presented in the surface modified layer. The thickness of implanted layer increased by about an order of magnitude when the temperature was elevated from 100 degree C to 600 degree C. Higher surface hardness and wear resistance was also obtained at higher temperature. Scanning electron microscopy (SEM) showed distinct microstructural changes and the presence of titanium nitrides in the implanted surface

  1. Ultraviolet electroluminescence from nitrogen-doped ZnO-based heterojuntion light-emitting diodes prepared by remote plasma in situ atomic layer-doping technique.

    Science.gov (United States)

    Chien, Jui-Fen; Liao, Hua-Yang; Yu, Sheng-Fu; Lin, Ray-Ming; Shiojiri, Makoto; Shyue, Jing-Jong; Chen, Miin-Jang

    2013-01-23

    Remote plasma in situ atomic layer doping technique was applied to prepare an n-type nitrogen-doped ZnO (n-ZnO:N) layer upon p-type magnesium-doped GaN (p-GaN:Mg) to fabricate the n-ZnO:N/p-GaN:Mg heterojuntion light-emitting diodes. The room-temperature electroluminescence exhibits a dominant ultraviolet peak at λ ≈ 370 nm from ZnO band-edge emission and suppressed luminescence from GaN, as a result of the decrease in electron concentration in ZnO and reduced electron injection from n-ZnO:N to p-GaN:Mg because of the nitrogen incorporation. The result indicates that the in situ atomic layer doping technique is an effective approach to tailoring the electrical properties of materials in device applications.

  2. The plasma membrane H+ -ATPase AHA2 contributes to the root architecture in response to different nitrogen supply

    DEFF Research Database (Denmark)

    Młodzińska, Ewa; Kłobus, Grażyna; Christensen, Monica Daugbjerg

    2015-01-01

    of lateral root primordia, root elongation and increase the root biomass. However, the signal transduction mechanisms, which enable roots to sense changes in different mineral environments and match their growth and development patterns to actual conditions in the soil, are still unknown. Most recent...... comments have focused on one of the essential macroelements, namely nitrogen, and its role in the modification of the root architecture of Arabidopsis thaliana. As yet, not all elements of the signal transduction pathway leading to the perception of the nitrate stimulus, and hence to anatomical changes...... of the root, which allow for adaptation to variable ion concentrations in the soil, are known. Our data demonstrate that primary and lateral root length were shorter lower in aha2 mutant lines compared to wild-type plants in response to a variable nitrogen source. This suggests that the plasma membrane proton...

  3. Magnetic properties of Co-N films deposited by ECR nitrogen/argon plasma with DC negative-biased Co target

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Zhang, Y.C.; Yang, K.; Liu, H.X.; Zhu, X.D., E-mail: xdzhu@ustc.edu.cn; Zhou, H.Y.

    2017-06-01

    Highlights: • A new method of synthesizing Co-N films containing Co{sub 4}N phase. • Tunable magnetic properties achieved in ECR plasma CVD. • The change of magnetic properties is related to atoms mobility on substrate and the concentration of active species in plasma vapor. - Abstract: By introducing DC negative-biased Co target in the Electron Cyclotron Resonance (ECR) nitrogen/argon plasma, the Co-N films containing Co{sub 4}N phase were synthesized on Si(100) substrate. Effects of processing parameters on magnetic properties of the films are investigated. It is found that magnetic properties of Co-N films vary with N{sub 2}/Ar flow ratio, substrate temperature, and target biasing voltage. The saturation magnetization M{sub s} decreased by increasing the N{sub 2}/Ar gas flow ratio or decreasing target biasing voltage, while the coercive field H{sub c} increased, which is ascribed to the variation of relative concentration for N or Co active species in plasma vapor. The magnetic properties present complex dependency with growth temperature, which is related to the atom mobility on the substrate affected by the growth temperature. This study exhibits a potential of ECR plasma chemical vapor deposition to synthesize the interstitial compounds and tune magnetic properties of films.

  4. Nitrogen uptake kinetics of freshly isolated zooxanthellae

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; Rajkumar, R.

    that for nitrate [2.8 nmol. ( mu chl-a)./1h/1] and urea [0.37 nmol. ( mu chl-a)./1h/1]. Half-saturation constants for uptake of the three nitrogen compounds were in the range of 10-15 mu mol.l/1. Generally, uptake of any one nitrogen substrate appears to be inhibit...

  5. Substituição do Milho pela Farinha de Mandioca de Varredura em Dietas de Cabras em Lactação: Fermentação Ruminal e Concentrações de Uréia Plasmática e no Leite Replacement of Corn by Cassava By-Product Meal in the Lactating Goat Diets: Effects on Diet Degradability, Ruminal Fermentation and Plasma and Milk Urea Concentrations

    Directory of Open Access Journals (Sweden)

    Gisele Fernanda Mouro

    2002-07-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da substituição do milho pela farinha de mandioca de varredura, em dietas de cabras Saanen em lactação, sobre a degradabilidade potencial, efetiva e efetiva corrigida das rações, bem como sobre o pH ruminal e as concentrações de amônia ruminal, uréia plasmática e uréia no leite em cabras em lactação. Foram utilizadas quatro cabras há 100 dias em lactação. O delineamento utilizado foi o quadrado latino 4 x4, em que os tratamentos consistiram em níveis de 0, 33, 67 e 100% de substituição do milho pela farinha de mandiocade varredura. A degradabilidade das rações experimentais foi determinada em bovinos pela técnica in situ. Apesar de a degradabilidade potencial das dietas experimentais ter tido pequena variação para MS, PB e amido, a degradabilidade efetiva e a degradabilidade efetiva corrigida da MS, da PB e do amido aumentaram com a substituição do milho pela farinha de varredura de mandioca. Os tratamentos não influenciaram o pH ruminal, bem como as concentrações de NH3-ruminal, uréia plasmática e uréia do leite. Houve correlação positiva (PThe objectives of this work were to evaluate effects of replacing corn by cassava by-product meal, in diets of Saanen lactating goats, on potencial, effective and corrected effective degradability of diets with steers, and on ruminal pH and ruminal ammonia, plasma urea nitrogen (PUN and milk urea nitrogen (MUN concentrations in lactating goats. Two steers and four multiparous goats fitted with ruminal cannula and 100 days in milking were used. The design was a 4 x 4 Latin square and treatments as following: 0, 33, 67 and 100% replacement of corn by cassava by-product meal. Rations degradability was determined using in situ technique. Potential degradability of experimental diets showed small variation for dry matter (DM, crude protein (CP and starch (S but effective and corrected effective degradability increased as corn was

  6. Diet-animal fractionation of nitrogen stable isotopes reflects the efficiency of nitrogen assimilation in ruminants.

    Science.gov (United States)

    Cantalapiedra-Hijar, G; Ortigues-Marty, I; Sepchat, B; Agabriel, J; Huneau, J F; Fouillet, H

    2015-04-14

    The natural abundance of ¹⁵N in animal proteins (δ¹⁵Nanimal) is greater than that in the diet consumed by the animals (δ¹⁵Ndiet), with a discrimination factor (Δ¹⁵N = δ¹⁵Nanimal - δ¹⁵Ndiet) that is known to vary according to nutritional conditions. The objectives of the present study were to test the hypothesis that Δ¹⁵N variations depend on the efficiency of nitrogen utilisation (ENU) in growing beef cattle, and to identify some of the physiological mechanisms responsible for this N isotopic fractionation in ruminants. Thus, we performed the regression of the Δ¹⁵N of plasma proteins obtained from thirty-five finishing beef cattle fed standard and non-conventional diets against different feed efficiency indices, including ENU. We also performed the regression of the Δ¹⁵N of different ruminant N pools (plasma and milk proteins, urine and faeces) against different splanchnic N fluxes obtained from multi-catheterised lactating dairy cows. The Δ¹⁵N of plasma proteins was negatively correlated with feed efficiency indices in beef cattle, especially ENU (body protein gain/N intake) and efficiency of metabolisable protein (MP) utilisation (body protein gain/MP intake). Although Δ¹⁵N obtained from different N pools in dairy cows were all negatively correlated with ENU, the highest correlation was found when Δ¹⁵N was calculated from plasma proteins. Δ¹⁵N showed no correlation with urea-N recycling or rumen NH₃ absorption, but exhibited a strong correlation with liver urea synthesis and splanchnic amino acid metabolism, which points to a dominant role of splanchnic tissues in the present N isotopic fractionation study.

  7. Comparative studies on the mineralization of furfural urea and urea ...

    African Journals Online (AJOL)

    In this research, laboratory studies were conducted to evaluate the effects of furfural urea as a slow release N fertilizer in an alfisol of Nigeria Savanna in the year 2009/2010 season. Incubation studies revealed that released N through mineralizatoin and microbial activities had confirmed that the compound may stay longer ...

  8. The effect of supplementing untreated, urea-supplemented and urea ...

    African Journals Online (AJOL)

    3x2x2 factorial experiment, involving an intake and in vivo digestibility trial with 48 adult S.A. Mutton Merino wethers. Straw dry matter (OM) intake on ammoniated wheat-straw diets was 27 and 22% higher (P ';;0,01) than on untreated and urea-supplemented diets, respectively. No significant difference was found between ...

  9. Individual renal plasma flow determination in 2 minutes

    International Nuclear Information System (INIS)

    Schlegel, J.U.; Hamway, S.A.

    1976-01-01

    A method is described for determining effective renal plasma flow, using the renal counts 1 to 2 minutes after injection and applying background subtraction as a ratio to the total amount of radioactivity injected intravenously with appropriate correction for kidney depth. It appears that this simple approach for determination of effective renal plasma flow within a matter of 2 minutes is accurate and reliable, and should be useful for a number of applications when it is important to determine total and individual renal plasma flow. The approach is recommended as a screening procedure in lieu of the determination of blood urea nitrogen and serum creatinine, with the additional advantages of gross morphology and determination of individual renal plasma flow in an absolute as well as relative manner

  10. Influence of Nitrogen Fertilizer and Vermicompost Application on Flower Yield and Essential Oil of Chamomile (Matricaria Chamomile L.)

    OpenAIRE

    Mohammad Reza Haj Seyed Hadi; Mohsen Abarghooei Fallah; Mohammad Taghi Darzi

    2015-01-01

       This study was performed to assess the effects of nitrogen fertilizer and vermicompost on qualitative and quantitative yield of chamomile (Matricaria chamomilla L.). It was conducted at the Research Fields of Ran Company located in Firouzkouh, Iran, in 2013. Treatments were consisted of 1) Control, 2) 100% nitrogen from urea, 3) 100% nitrogen from ammonium nitrate, 4) 75% nitrogen from urea and 25% from vermicompost, 5) 75% nitrogen from ammonium nitrate and 25% from vermicompost, 6) 50% n...