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Sample records for blood urea nitrogen

  1. 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 ...

  2. 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 ...

  3. 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 ...

  4. 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

  5. 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...

  6. 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)

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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

  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. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

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

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    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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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 ...

  7. 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

  8. 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

  9. 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)

  10. 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 ...

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Association between Blood Levels of Glucose and Urea and the ...

    African Journals Online (AJOL)

    osman

    2017-08-05

    Aug 5, 2017 ... Normal blood glucose and urea levels in dairy cows vary within breeds, ..... prolapse, and postpartum uterine haemorrhage, the effect of metabolic stress, ... and the effect of efficiency of heat detection on the average days to.

  16. 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)

  17. Influence of various levels of milk by-products in weaner diets on growth performance, blood urea nitrogen, diarrhea incidence, and pork quality of weaning to finishing pigs

    Science.gov (United States)

    2018-01-01

    Objective This study was conducted to evaluate various levels of milk by-product in weaning pig diet on growth performance, blood profiles, carcass characteristics and economic performance for weaning to finishing pigs. Methods A total of 160 weaning pigs ([Yorkshire×Landrace]×Duroc), average 7.01±1.32 kg body weight (BW), were allotted to four treatments by BW and sex in 10 replications with 4 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with various levels of milk by-product (Phase 1: 0%, 10%, 20%, and 30%, Phase 2: 0%, 5%, 10%, and 15%, respectively). During weaning period (0 to 5 week), weaning pigs were fed experimental diets and all pigs were fed the same commercial feed during growing-finishing period (6 to 14 week). Results In the growth trial, BW, average daily gain (ADG), and average daily feed intake (ADFI) in the nursery period (5 weeks) increased as the milk by-product level in the diet increased (linear, pby-product in weaner diet decreased crude protein (quadratic, p = 0.05) and crude ash (Linear, p = 0.05) of Longissimus muscle. In addition, cooking loss and water holding capacity increased with increasing milk product levels in the weaner diets (linear, pby-product treatment had higher feed cost per weight gain compared to non-milk by-products treatment (linear, p = 0.01). Conclusion Supplementation of 10% to 5% milk by-products in weaning pig diet had results equivalent to the 30% to 15% milk treatment and 0% milk by-product supplementation in the diet had no negative influence on growth performance of finishing pigs. PMID:29103280

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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...

  4. 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 +...

  5. 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

  6. Effects of polymer-coated slow-release urea on performance, ruminal fermentation, and blood metabolites in dairy cows

    Directory of Open Access Journals (Sweden)

    Gustavo Delfino Calomeni

    2015-09-01

    Full Text Available ABSTRACTThe objective of this experiment was to quantify the effects of feeding polymer-coated slow-release urea on nutrient intake and total tract digestion, milk yield and composition, nutrient balances, ruminal fermentation, microbial protein synthesis, and blood parameters in dairy cows. Sixteen Holstein cows (580±20 kg of live weight (mean ± standard deviation; 90 to 180 days in milk (DIM; and 28 kg/d of average milk yield were used in a replicated 4 × 4 Latin square experimental design. The animals were assigned to each square according to milk yield and DIM. The animals were randomly allocated to receive one of the following experimental diets: 1 control (without urea addition; urea (addition of 1% on the diet DM basis; polymer-coated slow release urea 1 (addition of 1% on the diet DM basis; and polymer-coated slow release urea 2 (addition of 1% on the diet DM basis. All diets contained corn silage as forage source and a 50:50 forage:concentrate ratio. Milk and protein yield, production of volatile fatty acids, and propionate decreased when cows were fed diets containing urea. Addition of urea decreased nitrogen efficiency and nitrogen excreted in the feces. However, the diets did not change the cows' microbial protein synthesis, ruminal pH, or ammonia concentration. The inclusion of urea in cow diets decreases milk and protein yield due to lower production of volatile fatty acids. No advantages are observed with supplementation of polymer-coated slow-release urea when compared with feed-grade urea.

  7. 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)

  8. 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.

  9. 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

  10. 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)

  11. 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...

  12. 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.

  13. 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

  14. 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 ...

  15. 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 ...

  16. 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.

  17. Analysis of the stability of urea in dried blood spots collected and stored on filter paper.

    Science.gov (United States)

    Quraishi, Rizwana; Lakshmy, Ramakrishnan; Mukhopadhyay, Ashok Kumar; Jailkhani, Bansi Lal

    2013-05-01

    The ability to use dry blood spots (DBSs) on filter paper for the analysis of urea levels could be an important diagnostic tool for areas that have limited access to laboratory facilities. We developed a method for the extraction and quantification of urea from DBSs that were stored on 3M Whatman filter paper and investigated the effect of long-term storage on the level of urea in DBSs. DBSs of 4.5 mm in diameter were used for our assay, and we determined the urea levels in blood using a commercially available enzymatic kit (UV GLDH-method; Randox laboratories Ltd., UK). The DBSs on filter discs were stored at 4℃ or at 37℃ for 120 days. The mean intra- and inter-assay coefficient of variance for our method of urea extraction from dried blood was 4.2% and 6.3%, respectively. We collected 75 fresh blood samples and compared the urea content of each fresh sample with the urea content of DBSs taken from corresponding fresh blood samples. Regression analysis reported a regression coefficient (r) value of 0.97 and a recovery of urea from dried spots was 102.2%. Urea concentrations in DBSs were stable for up to 120 and 90 days when stored at 4℃ and 37℃, respectively. Our results show that urea can be stored and quantitatively recovered from small volumes of blood that was collected on filter paper.

  18. 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)

  19. 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)

  20. 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 ...

  1. 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

  2. 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 ...

  3. 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...

  4. 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.

  5. Short communication: Assessing urea transport from milk to blood in dairy cows

    NARCIS (Netherlands)

    Spek, J.W.; Dijkstra, J.; Borne, van den J.J.G.C.; Bannink, A.

    2012-01-01

    The concentration of urea in milk (MUC) has emerged as a potentially useful tool to predict urinary N excretion. Various factors may affect the relationship between MUC and urinary N excretion, including transport characteristics of urea from blood to milk and vice versa. The main objective of this

  6. 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.

  7. 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.

  8. 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

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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...

  18. In vitro studies on the effect of physical cross-linking on the biological performance of aliphatic poly(urethane urea) for blood contact applications.

    Science.gov (United States)

    Thomas, V; Kumari, T V; Jayabalan, M

    2001-01-01

    The effect of physical cross-linking in candidate cycloaliphatic and hydrophobic poly(urethane urea) (4,4'-methylenebis(cyclohexylisocyanate), H(12)MDI/hydroxy-terminated polybutadiene, HTPBD/hexamethylenediamine, HDA) and poly(ether urethane urea)s (H(12)MDI/HTPBD-PTMG/HDA) on the in vitro calcification and blood-material interaction was studied. All the candidate poly(urethane urea)s and poly(ether urethane urea)s elicit acceptable hemolytic activity, cytocompatibility, calcification, and blood compatibility in vitro. The studies on blood-material interaction reveal that the present poly(urethane urea)s are superior to polystyrene microtiter plates which were used for the studies on blood-material interaction. The present investigation reveals the influence of physical cross-link density on biological interaction differently with poly(urethane urea) and poly(ether urethane urea)s. The higher the physical cross-link density in the poly(urethane urea)s, the higher the calcification and consumption of WBC in whole blood. On the other hand, the higher the physical cross-link density in the poly(ether urethane urea)s, the lesser the calcification and consumption of WBC in whole blood. However a reverse of the above trend has been observed with the platelet consumption in the poly(urethane urea)s and poly(ether urethane urea)s.

  19. 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.

  20. 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

  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. 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)

  3. 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.

  4. 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

  5. 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.

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

    African Journals Online (AJOL)

    Sibanda M

    2015-03-29

    Mar 29, 2015 ... Twenty-four clinically healthy animals in different parities, namely Parity 1 ..... In the dry spell there is low protein intake because of high fibrous diets from dry forage materials. (MacDonald .... Prentice Hall, Malaysia. Mapekula ...

  7. Haematological Indices and Blood Urea Nitrogen of Yankasa Ram ...

    African Journals Online (AJOL)

    reaction (Tanis and Naylor, 1968), while total proteins were estimated by Biuret method as described by. Henry and Stobel (1957). Albumin was determined by. Bromo Cresol ... means observed in the values of packed cell volume. (PCV) ...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Diagnostic value of blood urea and bilirubin levels determination in patients with gastroduodenal zone diseases

    Directory of Open Access Journals (Sweden)

    I. B. Zhakun

    2017-12-01

    Full Text Available The study of relationships of urea and bilirubin blood levels in patients with Helicobacter pylori associated gastroduodenal pathology (HP-aGDP has the considerable relevance for clinicians, since these indicators represent the status and function of the gastroduodenal zone. The aim of this study was to estimate changes of bilirubin and urea blood levels in patients with HP-aGDP before and after treatment. Materials and methods. Our study has included 59 patients of the main group with different HP-aGDP and 40 patients of the control group with community-acquired pneumonia (CAP. Results. In patients with HP-aGDP the doubly severe reduction of urea concentration was observed in significantly greater number of patients, while half of the patients in the controls had an increase of its level by 10.4 %. The bilirubin concentration decrease was more pronounced (37.1 % vs. 3.5 % and significant (p < 0.05 in patients with HP-aGDP. Its rate depended on the dynamics of urea exactly in patients with HP-aGDP and it was more pronounced in case of urea reduction (p < 0.05. Thus, the revealed association of bilirubin and urea levels changes, namely their decrease owing to the treatment, was inherent only to patients with HP-aGDP unlike to the patients with CAD. We also determined the involvement of lipid, carbohydrate and protein metabolism, electrolytes, composition of blood in the processes of local and systemic inflammation caused by HP and its relationship with adaptive reactions, which generally depended on other individual characteristics of patients in the study group (age, duration of disease, ulcer size, etc.. Conclusions. The monitoring of urea and bilirubin blood levels in patients especially with HP-aGDP during the eradication has a specific diagnostic and prognostic value. The bilirubin level in such cases reflects the severity of cholestasis, inflammatory lesions of the duodenal mucosa, comorbid hepatobiliary disease, while the urea level

  13. 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)

  14. 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.

  15. 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

  16. 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

  17. The Effect of Supplementation Urea and Sulfur in Mixed Cassava Waste Fermented and Soyabean Cake Waste on Digestibility of Protein and Blood Urea Male Sheep

    Directory of Open Access Journals (Sweden)

    M Bata

    1999-05-01

    Full Text Available Eighteen local male sheep were divided into 3 groups I,II and III based on the body weight 18.55±1.27, 15.79±0.67 and 13.14±1.33 kg respectively. Two level urea (2 and 3% and three levels Sulfur (0.02 and 0.3% as treatment, so pattern factorial 2x3 with Randomized Block Design used this experiment. All of the treatment get a same basal feed namely land-grass and concentrate with dry matter ratio 70:30.  The total intake of  dry matter was 4 % of body weight. The concentrate consist of cassava waste fermented  and soyabean cake waste with dry matter  ratio 77.50 : 22.50. Supplementation of urea and sulfur shown not significant interaction, but supplementation urea had effect high significantly (P<0.01 on digestibility of protein and sulfur only had effect significant  (P<0.05 on blood urea. These result had indication that enriched urea in the diet could increase protein digestibility and sulfur level 0.2% could prevent NH3 absorption from rumen. (Animal Production 1(2: 75-81 (1999   Key Words: cassava waste, soyabean cake waste, fermentation, digestibility, urea blood.

  18. 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

  19. 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

  20. 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.

  1. Association of serum uric acid with blood urea and serum creatinine

    International Nuclear Information System (INIS)

    Haq, A.U.; Ahmad, Z.; Rehman, J.U.

    2010-01-01

    Background: Hyperuricemia can cause serious health problems including renal insufficiency. Hyperuricemia is associated with many diseases including Hypertension, Diabetes Mellitus, Hypertriglyceridemia and Obesity. Objective of the present study was to study the Association of Serum Uric Acid with Blood Urea and Serum Creatinine. Methods: Eighty subjects, aged above 40, having blood urea more than 40 mg/dl and serum Creatinine more than 1.3 mg/dl were selected. 52.5 % subjects were male. Eighty subjects were selected as control group matching the age and sex with study group with normal blood urea and serum Creatinine. Results: Serum Uric Acid was found to be raised in 33 patients. Mean Serum Uric Acid value was 6.98+-2.021 in males (p<0.05) and 5.054+-2.324 in females (p<0.05). Conclusion: Serum Uric Acid is raised in patients with impaired renal function (p<0.05). Levels of increased Serum Uric Acid were not significantly associated with the cause of renal disease. (author)

  2. The permeability of red blood cells to chloride, urea and water

    DEFF Research Database (Denmark)

    Brahm, Jesper

    2013-01-01

    This study extends permeability (P) data on chloride, urea and water in red blood cells (RBC), and concludes that the urea transporter (UT-B) does not transport water. P of chick, duck, Amphiuma means, dog and human RBC to (36)Cl(-), (14)C-urea and (3)H2O was determined under self....... Temperature dependence, as measured by apparent activation energy, EA, of PCl is 117.8 (duck), 74.9 (Amphiuma) and 89.6 kJ mol(-1) (dog). The EA of Purea is 69.6 (duck) and 53.3 kJ mol(-1) (Amphiuma), and that of Pd is 34.9 (duck) and 32.1 kJ mol(-1) (Amphiuma). The present and previous RBC studies indicate......-exchange conditions. At 25°C and pH 7.2-7.5, PCl is 0.94×10(-4)-2.15×10(-4) cm s(-1) for all RBC species at [Cl]=127-150 mmol l(-1). In chick and duck RBC, Purea is 0.84×10(-6) and 1.65×10(-6) cm s(-1), respectively, at [urea]=1-500 mmol l(-1). In Amphiuma, dog and human RBC, Purea is concentration dependent (1...

  3. 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.

  4. BLOOD AMMONIA AND GLUTAMINE AS PREDICTORS OF HYPERAMMONEMIC CRISES IN UREA CYCLE DISORDER PATIENTS

    Science.gov (United States)

    Lee, Brendan; Diaz, George A.; Rhead, William; Lichter-Konecki, U.; Feigenbaum, Annette; Berry, Susan A.; Le Mons, C.; 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, A.; Vockley, Gerard.; Kronn, David; Zori, Roberto; Summar, Marshall; Milikien, D.A.; Marino, M.; Coakley, D.F.; Mokhtarani, M.; Scharschmidt, B.F.

    2014-01-01

    Purpose To examine predictors of ammonia exposure and hyperammonemic crises (HAC) in patients with urea cycle disorders (UCDs). Methods The relationships between fasting ammonia, daily ammonia exposure, and HACs were analyzed in >100 UCD patients. Results Fasting ammonia correlated strongly with daily ammonia exposure (r=0.764, p200% (purea nitrogen. Fasting glutamine correlated weakly with AUC0-24 and was not a significant predictor of HACs. Conclusions Fasting ammonia correlates strongly and positively with daily ammonia exposure and with the risk and rate of HACs, suggesting that UCD patients may benefit from tight ammonia control. PMID:25503497

  5. A simple apparatus for measuring the blood urea, manufactured by Dr. Luigj Benusi in 1943 in Albania

    OpenAIRE

    Tartari, Flamur; Buzo, Stiliano; Vyshka, Gentian

    2009-01-01

    The apparatus invented by Dr. Luigj Benusi in 1943, in Tirana, was a practical application of the Kowarsky technique and Ambard laws, helping in determining blood urea levels and very important to a variety of diseases, mainly kidney disorders. The apparatus was invented and prepared from very simple laboratory materials, such as glasses, test tubes, corks and volumetric cylinders. Technologically, it was based upon the determination of blood urea through hypobromite, and, among the advantage...

  6. 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....

  7. 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...

  8. 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

  9. 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)

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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...

  18. 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

  19. 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)

  20. 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.

  1. 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)

  2. [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

  3. 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)

  4. 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

  5. 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.

  6. Feed-derived volatile basic nitrogen increases reactive oxygen species production of blood leukocytes in lactating dairy cows.

    Science.gov (United States)

    Tsunoda, Ei; Gross, Josef J; Kawashima, Chiho; Bruckmaier, Rupert M; Kida, Katsuya; Miyamoto, Akio

    2017-01-01

    The present study investigated over 9 months the changes of fermentative quality of total mixed rations (TMR) containing grass silage (GS) as a major component, associated with changes in the volatile basic nitrogen (VBN) levels in an experimental dairy farm. Effects of VBN levels in TMR on metabolic parameters, reactive oxygen species (ROS) production by blood polymorphonuclear leukocytes (PMNs) and conception rates for dairy cows were analyzed. According to VBN levels in TMR during survey periods, three distinct phases were identified; phase A with low VBN; phase B with high VBN; and phase C with mid-VBN. Metabolic parameters in blood were all within normal range. However, during phases B and C, nitrogen metabolic indices such as blood urea nitrogen and milk urea nitrogen showed higher levels compared to those in phase A, and a simultaneous increase in ROS production by blood PMNs and the load on hepatic function in metabolic parameters was observed in the cows with a lower conception rate. This suggests that feeding TMR with elevated VBN levels due to poor fermented GS results in stimulation of ROS production by PMNs by ammonia, and negatively affects metabolism and reproductive performance in lactating dairy cow. © 2016 Japanese Society of Animal Science.

  7. 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

  8. 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...

  9. 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.)

  10. 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, ...

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. A simple apparatus for measuring the blood urea, manufactured by Dr. Luigj Benusi in 1943 in Albania.

    Science.gov (United States)

    Tartari, Flamur; Buzo, Stiliano; Vyshka, Gentian

    2009-01-01

    The apparatus invented by Dr. Luigj Benusi in 1943, in Tirana, was a practical application of the Kowarsky technique and Ambard laws, helping in determining blood urea levels and very important to a variety of diseases, mainly kidney disorders. The apparatus was invented and prepared from very simple laboratory materials, such as glasses, test tubes, corks and volumetric cylinders. Technologically, it was based upon the determination of blood urea through hypobromite, and, among the advantages of the apparatus of Benusi, were its extreme simplicity, the smaller amount of blood needed for producing results (2 milliliters), as well as an easiest way to clean up and to manage the apparatus from a practical point of everyday use.

  20. PROTEOSE INTOXICATIONS AND INJURY OF BODY PROTEIN : V. THE INCREASE IN NON-PROTEIN NITROGEN OF THE BLOOD IN ACUTE INFLAMMATORY PROCESSES AND ACUTE INTOXICATIONS.

    Science.gov (United States)

    Cooke, J V; Whipple, G H

    1918-08-01

    Sterile abscess formation in the dog is accompanied by a large increase in output of urinary nitrogen and also by a small but definite increase in the blood non-protein nitrogen. All this nitrogenous material of course is derived from body protein injury and autolysis. Septic inflammation in the dog (pleurisy, pneumonia, peritonitis, etc.) likewise shows a distinct rise in the blood non-protein nitrogen. This rise is not often so great as that frequently observed in the intoxication of intestinal obstruction. Many acute infections in man (septicemia, peritonitis, pneumonia, etc.) show a definite rise in the non-protein nitrogen and urea nitrogen of the blood; some cases show a very great rise above normal (over 100 mg. of non-protein nitrogen per 100 cc. of blood). There may be no anatomical change in the kidney beyond the familiar picture of cloudy swelling. This does not exclude the possibility of some transient functional derangement of the kidney epithelium. Certain obscure intoxications in man may show a considerable rise in the non-protein nitrogen of the blood, indicating a large amount of protein disintegration. These findings must be taken into account in any clinical analysis and interpretation of high non-protein nitrogen of the blood in pathological conditions.

  1. 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

  2. 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)

  3. 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...

  4. 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...

  5. Relations between 15N excretion in feces after oral intake of 15N-urea and urea concentration in the blood dependent on the crude fiber intake of pigs

    International Nuclear Information System (INIS)

    Bergner, H.; Tegtmeier, B.

    1985-01-01

    9 pigs (33 kg live weight at the beginning of the experiment) received in 3 consecutive series of experiments (3 animals/group) a basic barley ration of 1.0 - 1.2 kg per animal and day. In groups 1 to 9 the following supplements were given: (1) without N supplement, (2) 10.5 g urea, (3) 79 g dried skim milk, (4) 11 g urea, (5) without N supplement, (6) 110 g horse bean coarse meal, (7) without N supplement, (8) 95 g dried skim milk, (9) 120 g horse bean coarse meal. In groups 1 - 6 rations were supplemented with 150 - 165 g dry matter of partly hydrolyzed straw meal per animal and day. After 20 days the animals received a single dosis of 0.5 g/kg/sup 0.75/ 15 N-urea (72.1 atom-% 15 N excess) with the morning meal of the first day of the experiment. During the four days of the experiment groups 1 - 6, due to the straw meal supplement, excreted significantly higher N amounts than the corresponding groups 7 - 9. In comparison with the first day of the experiment (1 h after the morning meal) the urea concentration in the blood decreased to the following percentage in the order of the groups 1 - 9: 64; 65; 77; 54; 64; 73; 82; 88; 84 on the second day of the experiment (1 h before the evening meal). Between the excretion of 15 N excess in feces (y = mg) during the four days of the experiment and the concentration of urea in the blood (x = mmol/l) there was the following significant negative correlation: y = -40.1 x + 340. Urea elimination by means of urea inflow into the large intestine and subsequent bacterial protein synthesis (in the presence of fermentable crude fiber) significantly decreased urea concentration in the blood. (author)

  6. 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....

  7. 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

  8. 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...

  9. 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.

  10. 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

  11. 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

  12. 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

  13. Effect of levels of urea and cassava chip on feed intake, rumen fermentation, blood metabolites and microbial populations in growing goats

    Directory of Open Access Journals (Sweden)

    Metha Wanapat

    2007-01-01

    Full Text Available The study was conducted to assess effect of levels of urea and cassava chip (CC on feed intake, rumen ecology, blood metabolites and microbial populations. Four, Thai Native X Anglo Nubian crossbred growing male goats with an average liveweight 19.0+1 kg were randomly assigned according to a 4x4 Latin square design to receive one of four diets: T1=urea at 0 % (CC=30%, T2=urea at 1% (CC=40%, T3=urea at 2% (CC = 50% and T4=urea at 3%(CC=60%, of DM basis, respectively. Elephant grass (Pennisetum purpureum was offered on an ad lib basis. The results revealed that total DM intake (%BW and g/kg W0.75 and BW change were similar among treatments (p>0.05. Likewise, rumen pH, BUN, blood glucose, PCV and microbial populations were similar among treatments (p>0.05, while NH3-N increased as the urea level increased and were found highest (p<0.05 in T4 at 12.8 mg/dL. Based on this experiment, it can be concluded that a higher level of urea (3% could be used with a high level of CC in concentrate and it was good approach in exploiting the use of local feed resources for goat production.

  14. 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

  15. 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.

  16. 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.

  17. 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)

  18. Influence of Body Condition Score, blood ammonia and serum urea levels on conception rate in Italian Mediterranean buffaloes

    Directory of Open Access Journals (Sweden)

    G. Zicarelli

    2010-01-01

    Full Text Available In buffaloes, an optimal BCS at calving time improves reproductive efficiency (Baruselli et al., 2001 therefore shortening the calving/conception period and lowering the number of services/conception. In buffalo cows in negative energy balance a delayed ovulation and a reduced percentage of large follicles were found (Campanile et al., 2001. In buffaloes naturally mated protein degradability in the rumen did not influence reproductive activity (Campanile et al., 2003. It is possible that, independently of the Blood Area (BU, a lower diffusion of ammonia occurs in the uterus, reducing the detrimental effect on reproductive efficiency. The aim in the present study was to determine the influence of BCS, urea e ammonia blood levels on conception rate in Italian Mediterranean buffaloes synchronised and mated by AI in mid-winter which coincided with transition to the seasonal nadir in reproductive activity.

  19. 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.

  20. 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...

  1. Role of urea in controlling radiation-induced changes in some amino acids level and protein end products in blood serum of rats

    International Nuclear Information System (INIS)

    El-Kashef, H.S.; Saada, H.N.

    1991-01-01

    In previous studies (Helen Saada, 1982), urea could successfully act as a good radio-protector. It helps the recovery from changes induced by gamma irradiation in soluble protein contents, and percentage of protein fractions as well as some enzymatic activity. In the present study, it has been found that urea acts also as adequate radioprotector against radiation induced changes in the level of free and tied amino acids, glucosamine,free ammonia and urea concentration in the blood serum of white rats. The radioprotective role of urea was very clear on the first day after irradiation as manifested by the levels of free amino acids and protein end products (urea and ammonia). While in the case of tied amino acids, the action of urea as a radioprotector could be noticed lately, on the third post-irradiation day. The recovery from radiation hazards depended not only on the time lapse after irradiation but also on the chemical structure of the molecule which presents or constitutes the biological matter.2 tab.,1 fig

  2. 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.)

  3. 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)

  4. 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).

  5. Nitrogen balance, microbial protein synthesis and blood metabolites in fattening of male Bali cattle fed ration with different protein levels in smallholder farms

    Directory of Open Access Journals (Sweden)

    P. K. Tahuk

    2018-03-01

    Full Text Available Research was aimed to determine nitrogen balance, microbial protein synthesis, and blood metabolites of male Bali cattle fattening fed ration with different protein level in smallholder farms North Central Timor, Province of East Timor Tenggara, Indonesia. The cattle used were 18 heads aged 2 to 2.5 years with initial body weight of 229.86±12.46 kg. The cattle were randomly divided into three treatment groups. The T0 group was given feed the same as traditional fattening cattle practices by farmers,T1 group fed ration containing 12% crude protein (CP and 72% total digestible nutrients (TDN, andT2 group fedration containing 15% CP and 72%TDN. Cattle were fed individually for 90 days and drinkingwater ad libitum. The data were analyzedby analysis of variance.Results of research indicated the nitrogen balance, and blood urea nitrogen between T1 and T2 were relatively similar, but those were higher (P<0.05 than T0 . In contrast, microbial proteins synthesis, and blood glucose at 0, 4, and 6 hours before and after feeding were relatively similar between the groups. Blood glucose of T2 at 2 hours after intake were higher (P <0.05 than T0, but was not different with T1 . It can be concluded, that the fattening maleBali cattle fed ration containing 12% CP and 72% TDNimprovedthe nitrogen balance and blood metabolites, butit was no positive effect on the microbial proteins and N synthesis.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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

  14. 233 Haematological Characteristics and Blood

    African Journals Online (AJOL)

    2008-12-02

    Dec 2, 2008 ... nitrogen of Sokoto Red kids fed varying levels of Fore-stomach digesta (FSD) replacing cowpea husk at 0, 10, 20 and 30 ... Haematological Characteristics and Blood Urea Nitrogen of Sokoto Red Goat Kids Fed …… 228. Formulation of ..... significant rise in Hb level in treatment D. This is an indication that ...

  15. /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.

  16. 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)

  17. [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.

  18. Determination of Microbial Nitrogen Production by Using Urinary Allantoin and Blood Metabolite Concentrate in Growing Brahman Cattle Fed the Different Proportion of Roughage and Concentrate in Diets

    International Nuclear Information System (INIS)

    Suthikrai, Wanvipa; Usawang, Sungwon; Kijsamrej, Suriya; Sophon, Sunpetch; Jetana, Thongsuk

    2003-06-01

    Determination of microbial nitrogen synthesis by using urinary allantoin and blood metabolite for evaluating the efficiency of feed utilization, in this study was conducted by using four Brahman bulls (about 1 year old). Animals were fed ad libitum with 4 fixed diets of four combinations of pineapple fibre (P) and concentrate (C) in the proportions, on dry matter basis of 0.8:0.2 (P80:C20), 0.6:0.04(P60:C40), 0.4:0.6(P40:C60) and 0.2:0.8 (P20:C80). The experiment was designed as a 4x4 Latin square design The Results showed that increasing in the proportion of concentrate linearly increased the rumen microbial nitrogen production (p<0.001), the concentrations of Insulin and urea-N in plasma and the concentration of urea-N in the urine, but not affected on the concentrations of glucose and creatinine in plasma. In conclusion, the using of allantoin urinary associated with blood metabolite can evaluate the accuracy in evaluation of feed utilization in Brahman cattle

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. effects of catha edulis' leaf extract on blood chemistry and kidney

    African Journals Online (AJOL)

    2014-06-06

    Jun 6, 2014 ... its stimulating and euphoric effects have been shown to provide a strong inducement for .... disintegration of the active ingredients (12). The leaves were ..... products which are excreted through urine. High blood urea nitrogen ...

  6. Ground Juniperus pinchotii and urea in supplements fed to Rambouillet ewe lambs: I. Feedlot growth traits, blood serum parameters, and fecal characteristics.

    Science.gov (United States)

    Whitney, T R

    2017-08-01

    Ground woody products and urea are low-cost roughage and N sources. Rambouillet ewe lambs ( = 48, 6 lambs/treatment; initial BW = 42 kg ± 3.8) were used to evaluate effects of using ground (juniper) and urea in supplements on feedlot lamb growth traits, blood serum parameters, and fecal characteristics. In a randomized complete block design (40 d), lambs were individually fed an ad libitum basal sorghum-Sudangrass hay diet, which was fed separate from 1 of 8 supplemental diets (6 lambs/diet; 533 g of supplement/d, as-fed basis). Treatment structure was a 4 × 2 factorial: 4 concentrations of ground juniper (JN: 15%, 30%, 45%, or 60% of DM) and 2 concentrations of urea (UR: 1 or 3% of DM). Lamb growth traits were evaluated on d 0, 5, 12, 19, 26, 33, and 40; blood serum was evaluated on d 6 to 8, 20 to 22, and 34 (at h 3 and 6), and feces was evaluated on d 35. Compared to lambs fed all of the other treatments, lambs fed JN60UR1 or JN60UR3 had reduced supplement DMI (negative quadratic, = 0.007). Hay and total DMI were variable across day (JN × UR × day, 0.10). A JN × day interaction was detected ( 0.17) ADG and G:F. Lamb G:F fluctuated across day (JN × day, = 0.007), but the JN × day quadratic trend ( urea N quadratically increased ( urea N resulted from a greater decline from 3 to 6 h after feeding in lambs supplemented with UR1 vs. UR3. Increasing JN concentration tended to quadratically increase ( = 0.09) fecal DM and linearly decrease ( = 0.002) fecal N, but an effect due to dietary UR was not detected ( > 0.34). Results indicated that daily supplement DMI was restricted only by using JN60. However, a 60% JN-based supplement will not make an effective rangeland supplement for growing ewe lambs, and using 3% UR should not be considered, especially since daily UR intake was not restricted enough to be considered safe.

  7. 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

  8. Effect of transcutaneous electrical muscle stimulation and passive cycling movements on blood pressure and removal of urea and phosphate during hemodialysis.

    Science.gov (United States)

    Farese, Stefan; Budmiger, Raphael; Aregger, Fabienne; Bergmann, Ivo; Frey, Felix J; Uehlinger, Dominik E

    2008-10-01

    Intradialytic exercise has been described to improve blood pressure stability and dialysis efficacy. However, comorbid conditions in the dialysis population often preclude the widespread use of active intradialytic exercise. Therefore, we investigated the effect of intradialytic transcutaneous muscle stimulation (TEMS) and passive cycling movements (PCMs) on blood pressure and dialysis efficacy in patients. Prospective, controlled, randomized, crossover investigation. Ten patients were randomly allocated to TEMS, PCMs, or no intervention (NI) for 9 consecutive dialysis sessions. Participants were studied with NI, PCMs using a motor-driven ergometer, and bilateral TEMS of the leg musculature. Individual dialysis prescriptions were unchanged during the investigation. The effect of TEMS and PCMs on blood pressure and dialysis efficacy in patients was assessed. Mean blood pressure increased from 121/64 +/- 21/15 mm Hg with NI to 132/69 +/- 21/15 mm Hg (P TEMS. Urea and phosphate removal during dialysis were significantly (P TEMS (19.4 +/- 3.7 g/dialysis and 1,197 +/- 265 mg/dialysis) or PCMs (20.1 +/- 3.4 g/dialysis and 1,172 +/- 315 mg/dialysis) than with NI (15.1 +/- 3.9 g/dialysis and 895 +/- 202 mg/dialysis). Body weight, ultrafiltration, Kt/V, and increases in hemoglobin and albumin levels during dialysis did not differ among the NI, PCMs, and TEMS groups. The study design does not allow extension of the findings to prolonged treatment. Future studies during longer observation periods will have to prove the persistence of these acute findings. Both TEMS and PCMs deserve future investigations in dialysis patients because they increase intradialytic blood pressure and facilitate urea and phosphate removal when applied short term.

  9. 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

  10. 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

  11. 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

  12. 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

  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. Studies on the effect of virtual crosslinking on the hydrolytic stability of novel aliphatic polyurethane ureas for blood contact applications.

    Science.gov (United States)

    Thomas, V; Jayabalan, M

    2001-07-01

    The effect of virtual crosslinking on the hydrolytic stability of completely aliphatic novel poly(urethane ureas), HFL9-PU1 (hard-segment content 57.5%) and HFL13-PU2 (hard-segment content 67.9%) based on 4,4'-methylene bis(cyclohexyl isocyanate) (H(12)MDI)-hydroxy-terminated polybutadiene-1,6-hexamethylene diamine, was studied. Fourier transform infrared-attenuated total reflectance and wide-angle X-ray diffraction studies revealed hydrogen-bonding interaction and microphase separation and formation of crystallites by short- and long-range ordering in hard-segment domains. Three-dimensional networks from hydrogen bonding in the present polymers lead to virtually crosslinking and insolubility. These polymers were noncytotoxic to L929 fibroblast cells. The hemolytic potential is below the accepted limit. The studies on in vitro biostability in Ringer's solution, phosphate buffered saline, and papain enzyme revealed no weight loss. The infrared spectral studies revealed changes in the surface, especially on HFL9-PU1 aged in Ringer's solution and phosphate buffered saline, and no changes when aged in papain. The marginal changes noticed in tensile properties were attributed to the changes in degree of hydrogen bonding and associated rearrangement of molecular structure in the bulk. The results revealed that the lesser the crosslinking in virgin polymer, the higher the crosslinking in aged polymer and vice versa. Increased crosslinking during aging provided increased tensile properties in the aged polymer over the virgin polymer and vice versa. For comparison, an aliphatic polyetherurethane urea (HFL16-PU3) was also synthesized using poly(oxy tetra methylene glycol) in addition to the above reactants. Though both HFL9-PU1 and HFL16-PU3 contained the same hard-segment content, the aged sample of the latter showed decreased tensile properties with increased crosslinking during aging in contrast to the former. This was attributed to less microphase separation in the

  15. 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

  16. Lactulose efficacy in reduction of nitrogen products, blood potassium and fluid overload in patients with end-stage renal failure

    Directory of Open Access Journals (Sweden)

    Negin Aleagha

    2017-06-01

    Full Text Available Introduction: Chronic kidney disease (CKD is a major public health problem that often goes unrecognized until its late-stage. Patients with chronic kidney disease face uremic toxins and hyperkalemia. Also, fluid overload in CKD patients is associated with rapid decline in kidney function. Lactulose is a hyperosmotic agent and as a prebiotic, it plays an important role in regulating serum urea and potassium levels and has some effects on fluid overload. The aim of this study was to evaluate the effect of lactulose on serum levels of biochemical products in patients with CKD. Materials and Methods: In this interventional study, 17 patients with end stage of CKD ( 76.47 % men; mean age 65.88 ± 13.4 were evaluated.All patients received lactulose, 10 ml, 3 times per day for 3 months. Blood samples from all participants were collected before and at the end of intervention to examine changes in biochemical parameters, including potassium, urea, creatinine and uric acid. Results: Lactulose significantly decreased urea levels (p=0.001, blood potassium (0.001 and fluid overload(considering the patient’s weight p=0.001 in patients with end-stage renal failure. The decrease in serum creatinine and uric acid were not significant. Conclusion: Lactulose administration in CKD patients could decrease levels of various deleterious elements, especially urea and blood potassium and its daily use can be recommended in these patients.

  17. 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)

  18. Diagnosis and treatment of urea cycle disorder in Japan.

    Science.gov (United States)

    Nakamura, Kimitoshi; Kido, Jun; Mitsubuchi, Hiroshi; Endo, Fumio

    2014-08-01

    Urea cycle disorder (UCD) is an inborn error of the metabolic pathway producing urea from ammonia, which occurs primarily in the liver. Decreased excretion of nitrogen in the urea cycle due to deficiency of carbamoyl phosphate synthase I (CPSI), ornithine transcarbamylase (OTC), argininosuccinate synthase (ASS), argininosuccinate lyase (ASL), and N-acetyl glutamate synthase (NAGS) causes hyperammonemia. We examined the clinical manifestations, treatment, and prognosis of 177 patients with UCD from January 1999 to March 2009 in Japan. Compared with a previous study conducted in Japan, a larger number of patients survived without mental retardation, even when the peak blood ammonia was >360 μmol/L. In those with peak blood ammonia >360 μmol/L, an indicator of poor prognosis, the frequency of convulsions, mental retardation, brain abnormality on magnetic resonance imaging, hemodialysis, liver transplantation, and intake of non-protein formulas was significantly higher than in those with peak blood ammonia <360 μmol/L. In this article, we have reported the current state of UCD to evaluate prognosis and its relationship with peak blood ammonia and hemodialysis. © 2014 Japan Pediatric Society.

  19. 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

  20. Blood metabolomics analysis identifies abnormalities in the citric acid cycle, urea cycle, and amino acid metabolism in bipolar disorder.

    Science.gov (United States)

    Yoshimi, Noriko; Futamura, Takashi; Kakumoto, Keiji; Salehi, Alireza M; Sellgren, Carl M; Holmén-Larsson, Jessica; Jakobsson, Joel; Pålsson, Erik; Landén, Mikael; Hashimoto, Kenji

    2016-06-01

    Bipolar disorder (BD) is a severe and debilitating psychiatric disorder. However, the precise biological basis remains unknown, hampering the search for novel biomarkers. We performed a metabolomics analysis to discover novel peripheral biomarkers for BD. We quantified serum levels of 116 metabolites in mood-stabilized male BD patients (n = 54) and age-matched male healthy controls (n = 39). After multivariate logistic regression, serum levels of pyruvate, N-acetylglutamic acid, α-ketoglutarate, and arginine were significantly higher in BD patients than in healthy controls. Conversely, serum levels of β-alanine, and serine were significantly lower in BD patients than in healthy controls. Chronic (4-weeks) administration of lithium or valproic acid to adult male rats did not alter serum levels of pyruvate, N-acetylglutamic acid, β-alanine, serine, or arginine, but lithium administration significantly increased serum levels of α-ketoglutarate. The metabolomics analysis demonstrated altered serum levels of pyruvate, N-acetylglutamic acid, β-alanine, serine, and arginine in BD patients. The present findings suggest that abnormalities in the citric acid cycle, urea cycle, and amino acid metabolism play a role in the pathogenesis of BD.

  1. 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)

  2. 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.

  3. 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.

  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. Blood urea nitrogen to creatinine ratio is associated with congestion and mortality in heart failure patients with renal dysfunction.

    Science.gov (United States)

    Parrinello, Gaspare; Torres, Daniele; Testani, Jeffrey M; Almasio, Piero Luigi; Bellanca, Michele; Pizzo, Giuseppina; Cuttitta, Francesco; Pinto, Antonio; Butler, Javed; Paterna, Salvatore

    2015-12-01

    Renal dysfunction (RD) and venous congestion are related and common in heart failure (HF). Studies suggest that venous congestion may be the primary driver of RD in HF. In this study, we sought to investigate retrospectively the relationship between common measures of renal function with caval congestion and mortality among outpatients with HF and RD. We reviewed data from 103 HF outpatients (45 males, mean age 74 years, ejection fraction 41.8 ± 11.6 %) with estimated glomerular filtration rate (eGFR) of 25.5 (adjusted OR 2.98, p 0.015) and eGFR ≤ 45.8 (adjusted OR 5.38, p 0.002) identify patients at risk for caval congestion; a BUN/Cr > 23.7 was the best predictor of impaired collapsibility (adjusted OR 4.41, p 0.001). a BUN/Cr > 25.5 (HR 2.19, 95 % CI 1.21-3.94, p < 0.001) and NYHA class 3 (HR 2.91, 95 % CI 1.60-5.31, p < 0.0005) were independent risk factors associated with all-cause death during a median follow-up of 31 months. In outpatients with HF and RD, a higher BUN/Cr and lower eGFR are reliable renal biomarkers for caval congestion. The BUN/Cr is associated with long-term mortality and may help to stratify HF severity.

  6. Ureogenesis in Aantarctic birds-Blood levels of nitrogen compounds and liver and kidney arginase in penguins

    Directory of Open Access Journals (Sweden)

    Edson Rodrigues

    1998-03-01

    Full Text Available A study was carried out on the levels and the kinetics of liver and kidney arginase from Pygoscelis penguins, the gentoo Pygoscelis papua, the chinstrap, Pygoscelis antarctica, and the Adelie, Pygoscelis adeliae. Higher values of blood urea were found in the gentoo penguins in the native state when compared with specimens maintained in the fasting state for 24 hours. In the chinstrap penguin Pygoscelis antarctica the average value for blood urea was 1.5 times higher in the native state than in the fasting condition. In the native gentoo penguin P. papua the relative increase in the blood urea concentration is as high as 3.5 times in regard to the levels found in the fasting state. In regard to the blood levels of uric acid, the difference between the native state and the fasting state is 2.0 times for P. antarctica and 4.8 times for P. papua. Specific activities of arginase assayed in penguin liver were 561 mU/mg protein and 208mU/mg protein for adult P. antarctica and P. papua respectively. Kinetic studies with arginase from penguin liver homogenates showed Km values for L-arginine of 16.0±2.0mM at pH9.5. Arginase from birds possesses in general high Km values (between 100-200mM. It seems then that the high protein diet and the high levels of blood urea of penguins are a consequence of the levels of hepatic arginase and the high affinity of this enzyme toward its substrate.

  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. 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

  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. 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.

  11. Predicting mortality among older adults hospitalized for community-acquired pneumonia: an enhanced confusion, urea, respiratory rate and blood pressure score compared with pneumonia severity index.

    Science.gov (United States)

    Abisheganaden, John; Ding, Yew Yoong; Chong, Wai-Fung; Heng, Bee-Hoon; Lim, Tow Keang

    2012-08-01

    Pneumonia Severity Index (PSI) predicts mortality better than Confusion, Urea >7 mmol/L, Respiratory rate >30/min, low Blood pressure: diastolic blood pressure blood pressure 65 years (CURB-65) for community-acquired pneumonia (CAP) but is more cumbersome. The objective was to determine whether CURB enhanced with a small number of additional variables can predict mortality with at least the same accuracy as PSI. Retrospective review of medical records and administrative data of adults aged 55 years or older hospitalized for CAP over 1 year from three hospitals. For 1052 hospital admissions of unique patients, 30-day mortality was 17.2%. PSI class and CURB-65 predicted 30-day mortality with area under curve (AUC) of 0.77 (95% confidence interval (CI): 0.73-0.80) and 0.70 (95% CI: 0.66-0.74) respectively. When age and three co-morbid conditions (metastatic cancer, solid tumours without metastases and stroke) were added to CURB, the AUC improved to 0.80 (95% CI: 0.77-0.83). Bootstrap validation obtained an AUC estimate of 0.78, indicating negligible overfitting of the model. Based on this model, a clinical score (enhanced CURB score) was developed that had possible values from 5 to 25. Its AUC was 0.79 (95% CI: 0.76-0.83) and remained similar to that of PSI class. An enhanced CURB score predicted 30-day mortality with at least the same accuracy as PSI class did among older adults hospitalized for CAP. External validation of this score in other populations is the next step to determine whether it can be used more widely. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.

  12. 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

  13. 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)

  14. Assessment of the usefulness of the PIGE method to determine nitrogen in human blood serum

    International Nuclear Information System (INIS)

    Kupila-Rantala, T.; Hyvoenen-Dabek, M.; Raiasanen, J.; Dabek, J.T.

    1995-01-01

    Proton-induced gamma-ray emission (PIGE) analysis has been applied to the determination of total nitrogen concentration of blood sera from hospital patients. Both the reaction 14 N(p,p'γ) 14 N, E γ =2313 keV, and the reaction 15 N(p,αγ) 12 C,E γ =4439keV, have been used. From 37 patients, the range of the nitrogen concentrations obtained was 9.54-16.3 g/l with a mean of 12.0 g/l. The corresponding total protein concentrations varied between 59 and 96 g/l, measured in a clinical laboratory auto analyser using the biuret method. The range of the albumin concentrations was 29-46 g/l. The nitrogen concentrations correlated well with the total protein concentrations (r=0.802). The multiple correlation of nitrogen versus (albumin+ (total protein- albumin)) gives a coefficient of 0.175 for albumin and 0.161 for total protein- albumin. The results agree with expectations and support the potential usefulness of the rapid PIGE method for medical studies. (author). 17 refs., 3 figs

  15. 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.

  16. Quantification of urea in serum by isotope dilution HPLC/MS

    International Nuclear Information System (INIS)

    Lee, Hwa Shim; Park, Sang Ryoul

    2005-01-01

    Urea in blood has been measured as an effective marker for diagnosis of renal function. Urea which is the end-product of nitrogen containing metabolites such as proteins is filtered through glomeruli of kidneys and then excreted as urine. If the renal function is deteriorated, the urea concentration in blood will be increased, from which the healthiness of renal function is judged. In order to improve the confidence of diagnosis results, the results must keep traceability chain to certified reference materials, which was certified by primary reference method. In this study, we proposed Isotope Dilution-Liquid Chromatography/Mass Spectrometry (ID-LC/MS) as a candidate primary method, in which 15 N 2 -urea is used as an internal reference material. The developed method is highly accurate in principle and is convenient as it does not require cumbersome derivatization 0.1 mmol/L ammonium chloride was selected as a mobile phase for HPLC because it provide low interference in MS analysis of relatively low molecular weighted urea. HPLC and MS were connected with an ElectroSpry Ionization(ESI) interface of positive mode, which provided high sensitivity and reproducibility. The developed method was validated with internationally recognized reference materials, and we have obtained satisfactory results in an international ring trial. The expanded uncertainty calculated according to ISO guide was 1.8% at 95% confidence interval. The developed method is being used as a primary reference measurement method such as for certification of serum Certified Reference Materials (CRMs)

  17. 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

  18. 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...

  19. 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

  20. 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 ...

  1. 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

  2. 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

  3. 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...

  4. 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

  5. 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.

  6. 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.)

  7. 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.

  8. 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...

  9. 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)

  10. 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.

  11. Urea biosensor for hemodialysis monitoring

    Science.gov (United States)

    Glass, Robert S.

    1999-01-01

    An electrochemical sensor capable of detecting and quantifying urea in fluids resulting from hemodialysis procedures. The sensor is based upon measurement of the pH change produced in an aqueous environment by the products of the enzyme-catalyzed hydrolysis of urea. The sensor may be fabricated using methods amenable to mass fabrication, resulting in low-cost sensors and thus providing the potential for disposable use. In a typical application, the sensor could be used in treatment centers, in conjunction with an appropriate electronics/computer system, in order to determine the hemodialysis endpoint. The sensor can also be utilized to allow at-home testing to determine if dialysis was necessary. Such a home monitor is similar, in principle, to devices used for blood glucose testing by diabetics, and would require a blood droplet sample by using a finger prick.

  12. 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

  13. 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

  14. 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.)

  15. Exchange of nitrogenous substances between the body pool and the digestive tract in ruminants

    International Nuclear Information System (INIS)

    Boda, K.; Varady, J.; Havassy, I.; Kosta, K.; Fejes, J.; Kowalczyk, J.

    1976-01-01

    For a period of three months the only source of nitrogen in a group of sheep fed on a synthetic protein-free diet was perorally administered urea, and for a further period of three months intravenously administered urea. It was found that there was practically no variation in the weight of the animals and in the nitrogen balance. The total content of nitrogen and amino-nitrogen in the rumen with intravenous nitrogenous feeding showed that the rumen is adequately supplied with endogenous nitrogen. A clear-cut increase - by a factor of 2 - was observed in the endogenous metabolism as a whole. In experiments on sheep with a fistula of the rumen, duodenum or ileum, it was found that nitrogenous matter (total and microbic), synthesized from the 15 N of intravenously administered urea, is transported by the digestive apparatus with the common nitrogenous substances. In the rumen-duodenum part these substances are mainly secreted and in the intestinal part reabsorbed. Of the 15 N that passed through the duodenum, 73-84% was reabsorbed. Of the administered material, 4.8-5.7% was eliminated in the faeces. In experiments on sheep with an isolated intestine, it was observed that the secretion of blood urea, mainly in the forward part of the jejunum, is relatively high (3.4-3.9mg/h, whereas the rate of NH 3 production due to hydrolysis is relatively low (0.28-0.35mg/h). Of the 15 N-urea introduced via the fistula into the forward part of the jejunum, the average amount of 15 N remaining in the organism is 63%. Equal amounts of 15 N were eliminated in the urine, altogether 37%. It is assumed that the exchange of nitrogen between the digestive apparatus and the body pool is an important link in the nitrogen metabolism of ruminants. The blood urea and synthesized nitrogenous substances are important sources of nitrogen for digestive processes and for protein synthesis. The entire digestive apparatus participates in the utilization of ureal nitrogen. (author)

  16. 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.).

  17. 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.)

  18. 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.

  19. 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)

  20. 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

  1. Urea, a true uremic toxin: the empire strikes back.

    Science.gov (United States)

    Lau, Wei Ling; Vaziri, Nosratola D

    2017-01-01

    Blood levels of urea rise with progressive decline in kidney function. Older studies examining acute urea infusion suggested that urea was well-tolerated at levels 8-10× above normal values. More recent in vitro and in vivo work argue the opposite and demonstrate both direct and indirect toxicities of urea, which probably promote the premature aging phenotype that is pervasive in chronic kidney disease (CKD). Elevated urea at concentrations typically encountered in uremic patients induces disintegration of the gut epithelial barrier, leading to translocation of bacterial toxins into the bloodstream and systemic inflammation. Urea induces apoptosis of vascular smooth muscle cells as well as endothelial dysfunction, thus directly promoting cardiovascular disease. Further, urea stimulates oxidative stress and dysfunction in adipocytes, leading to insulin resistance. Finally, there are widespread indirect effects of elevated urea as a result of the carbamylation reaction, where isocyanic acid (a product of urea catabolism) alters the structure and function of proteins in the body. Carbamylation has been linked with renal fibrosis, atherosclerosis and anaemia. In summary, urea is a re-emerging Dark Force in CKD pathophysiology. Trials examining low protein diet to minimize accumulation of urea and other toxins suggest a clinical benefit in terms of slowing progression of CKD. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  2. Stable carbon and nitrogen incorporation in blood and fin tissue of the catfish Pterygoplichthys disjunctivus (Siluriformes, Loricariidae)

    OpenAIRE

    German, Donovan P.; Miles, Richard D.

    2010-01-01

    A feeding trial was performed in the laboratory with the catfish species Pterygoplichthys disjunctivus to determine stable carbon (13C) and nitrogen (15 N) turnover rates and discrimination factors in non-lethally sampled tissues (red blood cells, plasma solutes, and fin). A second feeding trial was conducted to determine what P. disjunctivus could assimilate from low-quality wood-detritus—refractory polysaccharides (e.g., cellulose), or soluble wood-degradation products inherent in wood-detr...

  3. 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)

  4. 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.

  5. 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.

  6. 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

  7. 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.)

  8. 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.

  9. 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.

  10. 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 ...

  11. 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

  12. Nitrogen recycling through the gut and the nitrogen economy of ruminants: an asynchronous symbiosis.

    Science.gov (United States)

    Reynolds, C K; Kristensen, N B

    2008-04-01

    The extensive development of the ruminant forestomach sets apart their N economy from that of nonruminants in a number of respects. Extensive pregastric fermentation alters the profile of protein reaching the small intestine, largely through the transformation of nitrogenous compounds into microbial protein. This process is fueled primarily by carbohydrate fermentation and includes extensive recycling of N between the body and gut lumen pools. Nitrogen recycling occurs via blood and gut lumen exchanges of urea and NH(3), as well as endogenous gut and secretory N entry into the gut lumen, and the subsequent digestion and absorption of microbial and endogenous protein. Factors controlling urea transfer to the gut from blood, including the contributions of urea transporters, remain equivocal. Ammonia produced by microbial degradation of urea and dietary and endogenous AA is utilized by microbial fermentation or absorbed and primarily converted to urea. Therefore, microbial growth and carbohydrate fermentation affect the extent of NH(3) absorption and urea N recycling and excretion. The extensive recycling of N to the rumen represents an evolutionary advantage of the ruminant in terms of absorbable protein supply during periods of dietary protein deficiency, or asynchronous carbohydrate and protein supply, but incurs a cost of greater N intakes, especially in terms of excess N excretion. Efforts to improve the efficiency of N utilization in ruminants by synchronizing fermentable energy and N availability have generally met with limited success with regards to production responses. In contrast, imposing asynchrony through oscillating dietary protein concentration, or infrequent supplementation, surprisingly has not negatively affected production responses unless the frequency of supplementation is less than once every 3 d. In some cases, oscillation of dietary protein concentration has improved N retention compared with animals fed an equal amount of dietary protein on

  13. 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.

  14. 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.

  15. 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

  16. Parenteral structured triglyceride emulsion improves nitrogen balance and is cleared faster from the blood in moderately catabolic patients.

    Science.gov (United States)

    Kruimel, J W; Naber, T H; van der Vliet, J A; Carneheim, C; Katan, M B; Jansen, J B

    2001-01-01

    Most postoperative patients lose net protein mass, which reflects loss of muscle tissue and organ function. Perioperative parenteral nutrition may reduce the loss of protein, but in general, with conventional lipid emulsions a waste of protein still remains. We compared the effects on nitrogen balance of an emulsion containing structured triglycerides, a new type of synthesized triglycerides, with an emulsion of a physical mixture of medium- and long-chain triglycerides as part of parenteral feeding in moderately catabolic patients. The first 5 days after placement of an aortic prosthesis patients received total parenteral nutrition (TPN) providing 0.2 g of nitrogen per kg body weight per day; energy requirement was calculated using Harris and Benedict's equation, adding 300 kcal per day for activity. Twelve patients were treated with the structured triglyceride emulsion and 13 patients with the emulsion of the physical mixture of medium- and long-chain triglycerides. The design was a randomized, double-blind parallel study. In the patients who completed the study, the mean cumulative nitrogen balance over the first 5 postoperative days was -8+/-2 g in 10 patients on the structured triglyceride emulsion and -21+/-4 g in 9 patients on the emulsion of the physical mixture of medium- and long-chain triglycerides; the mean difference was 13 g of nitrogen (95% confidence interval 4 to 22, p = .015) in favor of the structured triglyceride emulsion. On the first postoperative day serum triglyceride and plasma medium-chain free fatty acid levels increased less during infusion of the structured triglyceride emulsion than with the physical mixture emulsion. The parenteral structured triglyceride emulsion improves the nitrogen balance and is cleared faster from the blood, compared with the emulsion of the physical mixture of medium- and long-chain triglycerides, in moderately catabolic patients.

  17. SERUM AND PAROTID FLUIS UREA-LEVELS IN UNREALOADED HEALTHY YOUNG ADULTS

    Science.gov (United States)

    Forty-four healthy young adult male subjects were given oral doses of urea, and parotid fluid and serum urea levels were studied for 1 to 3 hours. A...highly significant correlation between urea in serum and in parotid fluid (r equals 0.982) was found. The indication was that, with flow rate...carefully controlled, parotid fluid could be used interchangeably with serum in urea determination, regardless of the magnitude of the blood concentration. (Author)

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. Blood urea nitrogen to serum creatinine ratio is an accurate predictor of outcome in diarrhea-associated hemolytic uremic syndrome, a preliminary study.

    Science.gov (United States)

    Keenswijk, Werner; Vanmassenhove, Jill; Raes, Ann; Dhont, Evelyn; Vande Walle, Johan

    2017-03-01

    Diarrhea-associated hemolytic uremic syndrome (D+HUS) is a common thrombotic microangiopathy during childhood and early identification of parameters predicting poor outcome could enable timely intervention. This study aims to establish the accuracy of BUN-to-serum creatinine ratio at admission, in addition to other parameters in predicting the clinical course and outcome. Records were searched for children between 1 January 2008 and 1 January 2015 admitted with D+HUS. A complicated course was defined as developing one or more of the following: neurological dysfunction, pancreatitis, cardiac or pulmonary involvement, hemodynamic instability, and hematologic complications while poor outcome was defined by death or development of chronic kidney disease. Thirty-four children were included from which 11 with a complicated disease course/poor outcome. Risk of a complicated course/poor outcome was strongly associated with oliguria (p = 0.000006) and hypertension (p = 0.00003) at presentation. In addition, higher serum creatinine (p = 0.000006) and sLDH (p = 0.02) with lower BUN-to-serum creatinine ratio (p = 0.000007) were significantly associated with development of complications. A BUN-to-sCreatinine ratio ≤40 at admission was a sensitive and highly specific predictor of a complicated disease course/poor outcome. A BUN-to-serum Creatinine ratio can accurately identify children with D+HUS at risk for a complicated course and poor outcome. What is Known: • Oliguria is a predictor of poor long-term outcome in D+HUS What is New: • BUN-to-serum Creatinine ratio at admission is an entirely novel and accurate predictor of poor outcome and complicated clinical outcome in D+HUS • Early detection of the high risk group in D+HUS enabling early treatment and adequate monitoring.

  3. Síntese de proteína microbiana e concentrações de uréia em vacas alimentadas com diferentes fontes de proteína Estimation of microbial protein synthesis and urea nitrogen metabolism in lactating dairy cows fed diets supplemented with different protein sources

    Directory of Open Access Journals (Sweden)

    Douglas dos Santos Pina

    2006-08-01

    Full Text Available Foram utilizadas 12 vacas Holandesas puras e mestiças, distribuídas em três quadrados latinos 4 x 4, organizados de acordo com os dias em lactação, com o objetivo de avaliar o efeito de diferentes fontes protéicas sobre a síntese, a eficiência de síntese de proteína microbiana, a concentração de nitrogênio uréico no soro (NUS e no leite (NUL, a concentração de nitrogênio amoniacal e o pH ruminal. Utilizou-se silagem de milho como volumoso, na proporção de 60% da MS total. Os concentrados foram constituídos de diferentes fontes protéicas (FS - farelo de soja; FA38 - farelo de algodão 38%PB; FA28 - farelo de algodão 28%PB e FSU - farelo de soja + 5% de uréia/sulfato de amônia na MS do concentrado. As coletas spot de urina e de sangue foram realizadas no 18º dia do período experimental 4 horas após o fornecimento da alimentação aos animais, no período da manhã. Não foram observadas diferenças entre as dietas para o volume urinário (V, a excreção total de derivados de purinas (PT, a síntese e a eficiência de síntese de PB microbiana, expressa em g de PB/kg de NDT consumido. As concentrações de NUS e NUL também não diferiram entre as dietas. As concentrações de NUS e NUL e a síntese de PB microbiana não foram influenciadas pelas diferentes fontes de proteína dietéticas, inclusive com a adição de uréia (5% MS do concentrado.Twelve Holstein lactating dairy cows were blocked by days in milk and randomly assigned to three replicated 4 x 4 Latin square to evaluate the effect of different protein sources on efficiency of microbial protein synthesis, concentration of serum (NUS and milk (MUN urea nitrogen, and ruminal metabolism. A basal corn silage diet (60% of the total dry matter was fed plus one of the following proteins sources (DM basis: soybean meal (SBM, cottonseed meal with 38% of crude protein (CSM38, cottonseed meal with 28% of crude protein (CSM28, or soybean meal plus 5% of urea

  4. 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 ...

  5. 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

  6. 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

  7. The Metabolic Conversion of Arginine in the Rumen Wall and its Importance in Ruminant Nitrogen Metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Harmeyer, J.; Kurelec, B.; Hill, H. [Department of Physiology, School of Veterinary Medicine, Hanover, Federal Republic of Germany (Germany)

    1968-07-01

    The functions of arginase and urease of the rumen wall were investigated in vitro and in vivo. Surviving ruminal mucosae of cattle were incubated for four hours. {sup 14}C-arginine-HCl, uniformly labelled, was added to the serosal side at a concentration of 10 pmol/mi. About 25% of the added arginine was used during the incubation by the ruminal tissue. In comparison with controls an increased amount of {sup 14}C-omithine, urea, and ammonia were formed in the mucosa and appeared on both sides. The increase was due to arginase and urease functions. It was estimated that about 50% of the urea formed by arginine breakdown were present at the mucosa side, mainly in the form of ammonia. Of the omithine simultaneously formed, 85% remained on the serosa side. Remarkable individual variations of omithine and urea formation were found from animal to animal. The in-vivo experiments were performed using goats with catheters placed in the right ruminal artery and vein. We injected 90 {mu}Ci of {sup 14}C-arginine into the ruminal artery. When 80 g of soluble starch were added to the rumen the activity and concentration of ornithine increased in the ruminal venous blood showing an arterial-venous difference. The radioactivity of urea in blood taken from the ruminal vein and the carotid artery did not show any difference. When starch was omitted from the rumen a comparable difference of omithine concentration was not found. It is assumed that the enzymes arginase and urease of the rumen wall are involved in nitrogen recycling processes. Blood arginine may be hydrolysed in the rumen wall forming urea and ornithine. Urea formed by arginine breakdown may be split to CO{sub 2} and ammonia. The experiments produced evidence that the ammonia formed preferably enters the rumen content. The nitrogen transfer through the rumen wall may be affected by varying activities of arginase. (author)

  8. 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

  9. Effect of serial-day exposure to nitrogen dioxide on airway and blood leukocytes and lymphocyte subsets

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, C.; Chen, L.L.; Erle, D.J.; Balmes, J.R. [Univ. of California, Lung Biology Center and Center for Occupational and Environmental Health, San Francisco, CA (United States); Christian, D.L.; Welch, B.S.; Dunham, E. [Univ. of California, Lung Biology Center, San Francisco, CA (United States); Kleinman, M.T. [Univ. of California, Dept. of Community and Environmental Medicine, Irvine, CA (United States)

    2000-07-01

    Nitrogen dioxide (NO{sub 2}) is a free radical-producing oxidant gas. Inhalation of NO2 could cause airway inflammation, and decrease immune function. This experiment tested the hypothesis that exposure to NO{sub 2} would: (1) increase leukocytes in bronchoalveolar lavage (BAL); and (2) change the distribution of lymphocyte subsets and activation in BAL and peripheral blood (PB). Using a counter-balanced, repeated-measures design, 15 healthy volunteers were exposed to filtered air (FA) or 2.0 parts per million NO{sub 2} for 4 h.day{sup -1} (4 x 30 min of exercise), for three consecutive days. Bronchoscopy was performed 18 h following each exposure set, and PB was drawn pre-exposure and pre-bronchoscopy. Flow cytometry was used to enumerate lymphocyte subsets and activation makers in BAL and PB. In the bronchial fraction, there was an increase in the percentage of neutrophils following NO2 exposure compared to FA (median (interquartile range): 10.6 (4.8. 17.2)% versus 5.3 (2.5-8.3)%; p=0.005). In the BAL, there was a decrease in the percentage of T-helper cells following NO{sub 2} exposure compared to FA (55.9 (40.8-62.7)% versus 61.6 (52.6-65.2)%; p=0.022). For PB, there were no between-condition differences in any leukocyte or lymphocyte subsets, or activation. In conclusion exposure to nitrogen dioxide results in bronchial inflammation and a minimal change in bronchoalveolar lavage T-helper cells, and no changes in peripheral blood cells. (au)

  10. 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 ...

  11. 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.

  12. Does the adequacy parameter Kt/V(urea reflect uremic toxin concentrations in hemodialysis patients?

    Directory of Open Access Journals (Sweden)

    Sunny Eloot

    Full Text Available Hemodialysis aims at removing uremic toxins thus decreasing their concentrations. The present study investigated whether Kt/V(urea, used as marker of dialysis adequacy, is correlated with these concentrations. Predialysis blood samples were taken before a midweek session in 71 chronic HD patients. Samples were analyzed by colorimetry, HPLC, or ELISA for a broad range of uremic solutes. Solute concentrations were divided into four groups according to quartiles of Kt/V(urea, and also of different other parameters with potential impact, such as age, body weight (BW, Protein equivalent of Nitrogen Appearance (PNA, Residual Renal Function (RRF, and dialysis vintage. Dichotomic concentration comparisons were performed for gender and Diabetes Mellitus (DM. Analysis of Variance in quartiles of Kt/V(urea did not show significant differences for any of the solute concentrations. For PNA, however, concentrations showed significant differences for urea (P<0.001, uric acid (UA, p-cresylsulfate (PCS, and free PCS (all P<0.01, and for creatinine (Crea and hippuric acid (HA (both P<0.05. For RRF, concentrations varied for β₂-microglobulin (P<0.001, HA, free HA, free indoxyl sulfate, and free indole acetic acid (all P<0.01, and for p-cresylglucuronide (PCG, 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF, free PCS, and free PCG (all P<0.05. Gender and body weight only showed differences for Crea and UA, while age, vintage, and diabetes mellitus only showed differences for one solute concentration (UA, UA, and free PCS, respectively. Multifactor analyses indicated a predominant association of concentration with protein intake and residual renal function. In conclusion, predialysis concentrations of uremic toxins seem to be dependent on protein equivalent of nitrogen appearance and residual renal function, and not on dialysis adequacy as assessed by Kt/V(urea. Efforts to control intestinal load of uremic toxin precursors by dietary or other

  13. 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...

  14. 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.

  15. 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.

  16. 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.)

  17. 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

  18. 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

  19. 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.

  20. 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 ...

  1. Sulfate, nitrate and blood pressure - An EPIC interaction between sulfur and nitrogen.

    Science.gov (United States)

    Kuhnle, Gunter G; Luben, Robert; Khaw, Kay-Tee; Feelisch, Martin

    2017-08-01

    Nitrate (NO 3 - )-rich foods such as green leafy vegetables are not only part of a healthy diet, but increasingly marketed for primary prevention of cardiovascular disease (CVD) and used as ergogenic aids by competitive athletes. While there is abundant evidence for mild hypotensive effects of nitrate on acute application there is limited data on chronic intake in humans, and results from animal studies suggest no long-term benefit. This is important as nitrate can also promote the formation of nitrosamines. It is therefore classified as 'probably carcinogenic to humans', although a beneficial effect on CVD risk might compensate for an increased cancer risk. Dietary nitrate requires reduction to nitrite (NO 2 - ) by oral commensal bacteria to contribute to the formation of nitric oxide (NO). The extensive crosstalk between NO and hydrogen sulfide (H 2 S) related metabolites may further affect nitrate's bioactivity. Using nitrate and nitrite concentrations of drinking water - the only dietary source continuously monitored for which detailed data exist - in conjunction with data of >14,000 participants of the EPIC-Norfolk study, we found no inverse associations with blood pressure or CVD risk. Instead, we found a strong interaction with sulfate (SO 4 2- ). At low sulfate concentrations, nitrate was inversely associated with BP (-4mmHg in top quintile) whereas this was reversed at higher concentrations (+3mmHg in top quintile). Our findings have a potentially significant impact for pharmacology, physiology and public health, redirecting our attention from the oral microbiome and mouthwash use to interaction with sulfur-containing dietary constituents. These results also indicate that nitrate bioactivation is more complex than hitherto assumed. The modulation of nitrate bioactivity by sulfate may render dietary lifestyle interventions aimed at increasing nitrate intake ineffective and even reverse potential antihypertensive effects, warranting further investigation

  2. Effects of Dietary Electrolyte Balance on Growth Performance, Nitrogen Metabolism and Some Blood Biochemical Parameters of Growing Rabbits

    Directory of Open Access Journals (Sweden)

    J. W. Li

    2013-12-01

    Full Text Available The effects of different dietary electrolyte balance (DEB on growth performance, nitrogen (N metabolism and some blood biochemical parameters were investigated in 2 to 3 months old growing rabbits. A total of 150 growing rabbits of 2 months age were randomly divided into five groups according to average body weight, with 30 rabbits in each group. The DEB levels of the five experimental diets were −154, −3.16, +201, +347, and +500 meq/kg of dry matter (DM, respectively. There was a 7-d adaptation period and a 23-d experimental period. The results showed that the DEB levels had a quadratic affect on the average daily feed intake (ADFI (p<0.001. The greatest ADFI was achieved when the DEB level was +201 meq/kg DM. Fecal N (FN content linearly decreased (0.047, while digestible N (DN, retained N (RN, efficiency of intake N converted into digestible N (DN/IN and the efficiency of intake N converted into retained N (RN/IN linearly increased with the DEB increase (0.020, 0.004, 0.021, and 0.049, respectively. Serum phosphorus (P ion content linearly increased with the DEB increase (p = 0.036. The DEB had a quadratic relationship with serum anion gap (AG (p = 0.002 and serum parathyroid hormone (PTH content (p = 0.016. The DEB levels quadratically affected base excess (BE in the plasma (p<0.001. In conclusion, the DEB unaffected growth performance but affected feed intake, N metabolism and some blood biochemical parameters of growing rabbits.

  3. 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%.

  4. 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

  5. Validation of myocardial blood flow estimation with nitrogen-13 ammonia PET by the argon inert gas technique in humans

    International Nuclear Information System (INIS)

    Kotzerke, J.; Glatting, G.; Neumaier, B.; Reske, S.N.; Hoff, J. van den; Hoeher, M.; Woehrle, J. n

    2001-01-01

    We simultaneously determined global myocardial blood flow (MBF) by the argon inert gas technique and by nitrogen-13 ammonia positron emission tomography (PET) to validate PET-derived MBF values in humans. A total of 19 patients were investigated at rest (n=19) and during adenosine-induced hyperaemia (n=16). Regional coronary artery stenoses were ruled out by angiography. The argon inert gas method uses the difference of arterial and coronary sinus argon concentrations during inhalation of a mixture of 75% argon and 25% oxygen to estimate global MBF. It can be considered as valid as the microspheres technique, which, however, cannot be applied in humans. Dynamic PET was performed after injection of 0.8±0.2 GBq 13 N-ammonia and MBF was calculated applying a two-tissue compartment model. MBF values derived from the argon method at rest and during the hyperaemic state were 1.03±0.24 ml min -1 g -1 and 2.64±1.02 ml min -1 g -1 , respectively. MBF values derived from ammonia PET at rest and during hyperaemia were 0.95±0.23 ml min -1 g -1 and 2.44±0.81 ml min -1 g -1 , respectively. The correlation between the two methods was close (y=0.92x+0.14, r=0.96; P 13 N-ammonia PET. (orig.)

  6. 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 ...

  7. 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

  8. 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

  9. Urea cycle disorders: a case report of a successful treatment with liver transplant and a literature review.

    Science.gov (United States)

    Foschi, Francesco Giuseppe; Morelli, Maria Cristina; Savini, Sara; Dall'Aglio, Anna Chiara; Lanzi, Arianna; Cescon, Matteo; Ercolani, Giorgio; Cucchetti, Alessandro; Pinna, Antonio Daniele; Stefanini, Giuseppe Francesco

    2015-04-07

    The urea cycle is the final pathway for nitrogen metabolism. Urea cycle disorders (UCDs) include a variety of genetic defects, which lead to inefficient urea synthesis. Elevated blood ammonium level is usually dominant in the clinical pattern and the primary manifestations affect the central nervous system. Herein, we report the case of a 17-year-old girl who was diagnosed with UCD at the age of 3. Despite a controlled diet, she was hospitalized several times for acute attacks with recurrent life risk. She came to our attention for a hyperammonemic episode. We proposed an orthotopic liver transplant (OLT) as a treatment; the patient and her family were in complete agreement. On February 28, 2007, she successfully received a transplant. Following the surgery, she has remained well, and she is currently leading a normal life. Usually for UCDs diet plays the primary therapeutic role, while OLT is often considered as a last resort. Our case report and the recent literature data on the quality of life and prognosis of traditionally treated patients vs OLT patients, support OLT as a primary intervention to prevent life-threatening acute episodes and chronic mental impairment.

  10. 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.

  11. A longitudinal study of urea cycle disorders.

    Science.gov (United States)

    Batshaw, Mark L; Tuchman, Mendel; Summar, Marshall; Seminara, Jennifer

    2014-01-01

    The Urea Cycle Disorders Consortium (UCDC) is a member of the NIH funded Rare Diseases Clinical Research Network and is performing a longitudinal study of 8 urea cycle disorders (UCDs) with initial enrollment beginning in 2006. The consortium consists of 14 sites in the U.S., Canada and Europe. This report summarizes data mining studies of 614 patients with UCDs enrolled in the UCDC's longitudinal study protocol. The most common disorder is ornithine transcarbamylase deficiency, accounting for more than half of the participants. We calculated the overall prevalence of urea cycle disorders to be 1/35,000, with 2/3rds presenting initial symptoms after the newborn period. We found the mortality rate to be 24% in neonatal onset cases and 11% in late onset cases. The most common precipitant of clinical hyperammonemic episodes in the post-neonatal period was intercurrent infections. Elevations in both blood ammonia and glutamine appeared to be biomarkers for neurocognitive outcome. In terms of chronic treatment, low protein diet appeared to result in normal weight but decreased linear growth while N-scavenger therapy with phenylbutyrate resulted in low levels of branched chain amino acids. Finally, we found an unexpectedly high risk for hepatic dysfunction in patients with ornithine transcarbamylase deficiency. This natural history study illustrates how a collaborative study of a rare genetic disorder can result in an improved understanding of morbidity and disease outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Temporal Progression of Pneumonic Plague in Blood of Nonhuman Primate: A Transcriptomic Analysis

    Science.gov (United States)

    2016-03-22

    urea nitrogen (BUN), Fig 2. Potentially activated and inhibited GoI-Time enriched pathways across the time course. The canonical pathways enriched by up...journal.pone.0151788 March 22, 2016 8 / 21 The quantitative measurements of Y. pestis present in the exposed animals’ blood and urine samples and...leukocytes (S5B Fig), formation of cellular inclusion bodies, synthesis of extracellular matrix, and myocardial and liver failure. Protein ubiquitination

  13. 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.

  14. 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.

  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. 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.

  18. 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.

  19. 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)

  20. Evaluation of the contribution of recycled urea to the synthesis of the microbial of protein in the rumen using sup 15 N labelled urea

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dehneh, A M [Michigan State Univ. (USA) Dept. of Animal Science

    1990-01-01

    Urea {sup 15}N was continually infused into the juglar vein for 3 days in two duodenally cannulated cows fed diets of 1:2 and 2:1 forage: concentrate. Duodenal digesta samples were taken every 3 hours, and coccygeal blood and milk were sampled twice daily. Urine was collected for 5 days starting 1 day before infusion and total feces for 3 days during infusion. Fecal samples were also taken twice daily during the 5 days of collection. Urinary excretion of {sup 15}N accounted for about 90% of that which existed from the body; whereas, feces and milk each accounted for about 5%. Recovery of {sup 15}N during the infusion period ranged from 30 to 50% of that infused. Estimates using {sup 15}N ratios, as percent of the total N passing into the duodenum, that was bacterial N, were 50% to 90% and appeared directly proportional to dry matter intake of cows. Recycled-N incorporated into rumen microbes was greater (24% verses 14% of N in bacteria passing into the duodenum) in cows fed the high concentrate than the high forage diet. Also, incorporation of recycled N into rumen microbes was higher in the lactating than the dry cow (24% verses 14%) and the flow of nitrogen from the rumen to the small intestine was greater for the concentrate than the forage diet (122.O% verses 101.0% of nitrogen intake). (author). 27 refs.

  1. Evaluation of the contribution of recycled urea to the synthesis of the microbial of protein in the rumen using 15N labelled urea

    International Nuclear Information System (INIS)

    Al-Dehneh, A.M.

    1990-01-01

    Urea 15 N was continually infused into the juglar vein for 3 days in two duodenally cannulated cows fed diets of 1:2 and 2:1 forage: concentrate. Duodenal digesta samples were taken every 3 hours, and coccygeal blood and milk were sampled twice daily. Urine was collected for 5 days starting 1 day before infusion and total feces for 3 days during infusion. Fecal samples were also taken twice daily during the 5 days of collection. Urinary excretion of 15 N accounted for about 90% of that which existed from the body; whereas, feces and milk each accounted for about 5%. Recovery of 15 N during the infusion period ranged from 30 to 50% of that infused. Estimates using 15 N ratios, as percent of the total N passing into the duodenum, that was bacterial N, were 50% to 90% and appeared directly proportional to dry matter intake of cows. Recycled-N incorporated into rumen microbes was greater (24% verses 14% of N in bacteria passing into the duodenum) in cows fed the high concentrate than the high forage diet. Also, incorporation of recycled N into rumen microbes was higher in the lactating than the dry cow (24% verses 14%) and the flow of nitrogen from the rumen to the small intestine was greater for the concentrate than the forage diet (122.O% verses 101.0% of nitrogen intake). (author). 27 refs

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Salivary creatinine and urea analysis in patients with chronic kidney disease: a case control study.

    Science.gov (United States)

    Lasisi, Taye Jemilat; Raji, Yemi Raheem; Salako, Babatunde Lawal

    2016-01-16

    Many metabolic changes develop in patients with chronic kidney disease which often necessitate frequent biochemical analysis of blood. Saliva analysis as an alternative to blood has many advantages. The aims of this study were to evaluate levels of salivary creatinine and urea in patients with chronic kidney disease in comparison to healthy individuals; to determine correlation between salivary creatinine/urea and blood creatinine/urea and to evaluate the diagnostic potential of saliva. A case control study, involving 50 patients with late stage chronic kidney disease and 49 healthy individuals as control. Blood and saliva samples were analyzed for urea and creatinine levels. Data are presented as median with interquartile range and compared using Independent Samples Mann Whitney U test. Correlation between plasma and salivary creatinine as well as urea was determined using Spearman's correlation test. Receiver operating characteristics (ROC) analysis was done to determine the diagnostic ability of salivary creatinine and urea and cut-off values were established. Median salivary creatinine levels were 2.60 mg/dl and 0.20 mg/dl while median salivary urea levels were 92.00 mg/dl and 20.50 mg/dl in patients with chronic kidney disease and controls respectively. Salivary levels of creatinine and urea were significantly elevated in chronic kidney disease patients (p creatinine as well as urea levels. Total areas under the curve for salivary creatinine and urea were 0.97 and 0.89 respectively. Cut-off values for salivary creatinine and urea were 0.55 mg/dl and 27.50 mg/dl respectively which gave sensitivity and specificity of 94 % and 85 % for creatinine; as well as 86 % and 93 % for urea. Findings of this study suggest that analysis of salivary creatinine and urea in patients with chronic kidney disease reflects their levels in blood. Hence, salivary creatinine and urea could be used as diagnostic biomarkers of chronic kidney disease.

  9. Reduction in slow intercompartmental clearance of urea during dialysis

    International Nuclear Information System (INIS)

    Bowsher, D.J.; Krejcie, T.C.; Avram, M.J.; Chow, M.J.; Del Greco, F.; Atkinson, A.J. Jr.

    1985-01-01

    The kinetics of urea and inulin were analyzed in five anesthetized dogs during sequential 2-hour periods before, during, and after hemodialysis. The distribution of both compounds after simultaneous intravenous injection was characterized by three-compartment models, and the total volumes of urea (0.66 +/- 0.05 L/kg) and inulin (0.19 +/- 0.01 L/kg) distribution were similar to expected values for total body water and extravascular space, respectively. Intercompartmental clearances calculated before dialysis were used to estimate blood flows to the fast and slow equilibrating compartments. In agreement with previous results, the sum of these flows was similar to cardiac output, averaging 101% of cardiac output measured before dialysis (range 72% to 135%). Dialysis was accompanied by reductions in the slow intercompartmental clearances of urea (81%) and inulin (47%), which reflected a 90% attenuation in blood flow supplying the slow equilibrating compartments. This was estimated to result in a 10% average reduction in the efficiency with which urea was removed by dialysis (range 2.0% to 16.4%). Mean arterial pressure fell by less than 5% during dialysis, but total peripheral resistance increased by 47% and cardiac output fell by 35%. In the postdialysis period, total peripheral resistance and cardiac output returned toward predialysis values, but blood flow to the slow equilibrating peripheral compartment was still reduced by 80%. These changes parallel activation of the renin-angiotensin system, but further studies are required to establish causality

  10. 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

  11. 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...

  12. 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.

  13. 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.

  14. Carbon and nitrogen isotopic signatures and nitrogen profile to identify adulteration in organic fertilizers.

    Science.gov (United States)

    Verenitch, Sergei; Mazumder, Asit

    2012-08-29

    Recently it has been shown that stable isotopes of nitrogen can be used to discriminate between organic and synthetic fertilizers, but the robustness of the approach is questionable. This work developed a comprehensive method that is far more robust in identifying an adulteration of organic nitrogen fertilizers. Organic fertilizers of various types (manures, composts, blood meal, bone meal, fish meal, products of poultry and plant productions, molasses and seaweed based, and others) available on the North American market were analyzed to reveal the most sensitive criteria as well as their quantitative ranges, which can be used in their authentication. Organic nitrogen fertilizers of known origins with a wide δ(15)N range between -0.55 and 28.85‰ (n = 1258) were characterized for C and N content, δ(13)C, δ(15)N, viscosity, pH, and nitrogen profile (urea, ammonia, organic N, water insoluble N, and NO3). A statistically significant data set of characterized unique organic nitrogen fertilizers (n = 335) of various known origins has been assembled. Deliberately adulterated samples of different types of organic fertilizers mixed with synthetic fertilizers at a wide range of proportions have been used to develop the quantitative critical characteristics of organic fertilizers as the key indicators of their adulteration. Statistical analysis based on the discriminant functions of the quantitative critical characteristics of organic nitrogen fertilizers from 14 different source materials revealed a very high average rate of correct classification. The developed methodology has been successfully used as a source identification tool for numerous commercial nitrogen fertilizers available on the North American market.

  15. Effects of a hot-water extract of porcini (Boletus aestivalis) mushrooms on the blood pressure and heart rate of spontaneously hypertensive rats.

    Science.gov (United States)

    Midoh, Naoki; Miyazawa, Noriko; Eguchi, Fumio

    2013-01-01

    The repeated once-daily oral administration of a hot-water extract of porcini, Boletus aestivalis, mushrooms (WEP) to spontaneously hypertensive rats (SHR) for 18 weeks decreased the systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate. The WEP administration also decreased blood urea nitrogen (BUN), creatinine (Cre), and triglyceride (TG), and increased high-density lipoprotein-cholesterol (HDL-C) in the blood, suggesting that WEP improved the status of hypertension, as well as the high heart rate and metabolic abnormalities involved in hypertension.

  16. The Kinetics of Urea in the Body after Liver Resection in the Experiment

    Directory of Open Access Journals (Sweden)

    P. N. Savilov

    2016-01-01

    Full Text Available Purpose. To study urea kinetics in the body after liver resection in the experiment.Material and Methods. Experiments were carried out on 45 white female rats weighing between 180 g and 220 g. Liver resection (LR was performed under ester anesthesia, wherein 15—20% of the organ weight was removed. Urea content was studied in biological fluids (arterial blood, venous — v.porta, v.hepatica, v.renalis — blood, choledochal bile, urine, and tissues of visceral organs (the thyroid gland, lungs, heart, liver, kidneys, spleen, stomach, intestine on days 3, 7, and 14 after LR. Results. LR, while reducing the urea content in the v. hepatica blood, does not lead to similar changes in the arterial blood. This is accompanied by increased urea reabsorption in kidneys and higher v.porta blood urea content, which, depending on the postoperative time, results either from reduced urea excretion into the small intestine lumen or from its greater production by enterocytes followed by metabolite intake into the portal blood flow. The urea intake from hepatocytes into the hepatic bile ducts did not change on day 3 after LR; however, it increased on day 7 and slowed down on day 14. LR caused no changes in the gastric tissues urea content; never theless, it led to its increased content in the duodenal and colonic tissues. Without affecting the cardiac muscleurea content, LR entailed its increase in the lungs and thyroid gland on postoperative days 3, 7, and 14. At the background of absence of similar changes in the arterial blood data indicates promotion of urea production by the cells of these organs or metabolite retention therein.Conclusions. LR not only changes urea kinetics in the portal system organs, but also activates extrahepatic mechanisms aimed at preventing development of the arterial blood urea deficit because of its abnormal intake from the resected organ into the central blood flow.

  17. 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...

  18. 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

  19. 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 ...

  20. 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 ...

  1. 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...

  2. The effect of urea with urease inhibitors and urea on yield and nitrate content in potato tubers

    Directory of Open Access Journals (Sweden)

    Karel Drápal

    2013-01-01

    Full Text Available The three-year field trial was established on two localities – Žabčice and Valečov in 2010–2012. Seven variants of nitrogen fertilization in four replications have been involved in this experiment – 100% of urea (U, 80% of urea, 60% of urea, 100% of UreaStabil (US, 80% of UreaStabil and 60% of UreaStabil, whilst 100% corresponded to 90 kg N.ha−1 after subtracting the content of Nmin in the soil, and the control variant without fertilization by mineral nitrogen. The two varieties with different lengths of vegetation periods have been chosen for the experiment – the early variety Karin and the mid-early variety Red Anna. In all cases, samples for the yield and qualitative analyses have been taken according to the phenological phase – the beginning of physiological maturity. The obtained results show that the highest average yield has been achieved in the variant of 100% of urea – 40.95 t. ha−1, the yield of this variant was statistically significantly higher than the yield of the other variants of fertilization (P < 0.05. Variants treated by urea without the urease inhibitor reached an average yield of 37.62 t.ha−1. However, this yield was not statistically significantly higher when comparing to the urea with the urease inhibitor (P > 0.05. In regard to localities, a relatively high average yield (44.58 t.ha−1 has been achieved on a characteristically potato-growing locality Valečov. This yield was statistically significantly higher than the one attained on the Žabčice locality (P < 0.05. In respect to varieties, the mid-early variety Red Anna attained a higher average yield (39.65 t. ha−1. Likewise, this yield was statistically significantly higher than the one of the early variety Karin (P < 0.05. The best year was 2012, in which the average yield of 38.73 t.ha−1 was achieved. This yield was statistically significantly higher than the yield of the year 2010 (P < 0.05. As far as nitrates are concerned, the

  3. 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

  4. High content of pyridinic- and pyrrolic-nitrogen-modified carbon nanotubes derived from blood biomass for the electrocatalysis of oxygen reduction reaction in alkaline medium

    International Nuclear Information System (INIS)

    Zheng, Jie; Guo, Chaozhong; Chen, Chunyan; Fan, Mingzhi; Gong, Jianping; Zhang, Yanfang; Zhao, Tianxin; Sun, Yuelin; Xu, Xiaofan; Li, Mengmeng; Wang, Ran; Luo, Zhongli; Chen, Changguo

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •An ORR electrocatalyst was fabricated from blood biomass and carbon nanotube. •The N-CNT catalyst exhibits good ORR activity, methanol resistance and stability. •The pyrolysis process produces high contents of pyridinic and pyrrolic N species. •The pyridinic-N group may play more important role in the active sites for ORR. -- Abstract: Here we present a facile synthetic route to design nitrogen-doped nanostructured carbon-based electrocatalyst for oxygen reduction reaction (ORR) by the copyrolysis of blood biomass from pig and carbon nanotubes (CNTs) at high temperatures. The nitrogen-doped CNTs obtained at 800 °C not only results in excellent ORR activity with four-electron transfer selectivity in alkaline medium, but also exhibits superior methanol-tolerant property and long-term stability. It is confirmed that high-temperature pyrolysis processes can facilitate to produce higher contents of pyridinic- and pyrrolic-N binding groups in electrocatalysts, contributing to the enhancement of ORR performance in terms of onset potential, half-wave potential, and limited current density. We also propose that the planar-N configuration may be the active site that is responsible for the improved ORR electrocatalytic performance. The straight-forward and cheap synthesis of the active and stable electrocatalyst makes it a promising candidate for electrochemical power sources such as fuel cells or metal-air batteries

  5. 15N-urea transport and transformation in two deforsted Amazonian soils under laboratory conditions

    International Nuclear Information System (INIS)

    Victoria, R.L.; Libardi, P.L.; Reichardt, K.; Matsui, E.

    1982-01-01

    Brazilian agriculture is now expanding toward the Amazon region, where large new areas of virgin lands are being brought under cultivation. There is therefore an urgent need to better understand the conditions and characteristics of the soils of that region. In this study a Red Yellow Podzol and a Yellow Latosol were used to examine urea transport and transformation in the laboratory under water-saturated conditions. The soils were collected in an area that was deforested in 1976 and planted to tropical fruits since then. Soils were subjected to miscible displacement techniques under both continuous feed and pulse applications of urea to mathematically describe urea transport and transformation as functions of depth and time. Transformation mechanisms were considered to be first order kinetics. Urea was readily leached from both soils. Recovery of urea in the effluent of the 30 cm columns was 91%, for the Podzol and 86% for the Latosol. NH 4+ -N from urea hydrolysis was also readily leached and its recovery in the effluent was 4.2% for the Podzol and 11.2% for the Latosol. Very little nitrogen-including exchangeable NH 4+ -N and biomass nitrogen - was left in the columns of either soil at the end of the experiment. (orig.)

  6. 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.

  7. Ethanol induction of laccase depends on nitrogen conditions of Pycnoporus sanguineus

    Directory of Open Access Journals (Sweden)

    Christian A. Hernández

    2015-07-01

    Conclusions: We suggest that laccase in P. sanguineus is regulated by a catabolic nitrogen repression mechanism; laccase activity is strongly inhibited by urea used as nitrogen source and it decreases when the amount of urea increases; contrarily, a synergic positive effect was observed between yeast extract and ethanol on laccase production.

  8. Leaching of dieldrin, permethrin, phenyl urea and 4-CL phenyl urea pesticides from soil

    International Nuclear Information System (INIS)

    Onal, G.

    1978-01-01

    Leaching of four 14 C-labelled pesticides (dieldrin, permethrin, phenyl urea and 4-Cl phenyl urea) were investigated. It was found that dieldrin and permethrin were not leached from soil but adsorbed by the soil; phenyl urea and 4-CL phenyl urea were leached to a 7.5 cm depth

  9. 40 CFR 721.9892 - Alkylated urea.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkylated urea. 721.9892 Section 721... Alkylated urea. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an alkylated urea (PMN P-93-1649) is subject to reporting under this...

  10. 40 CFR 721.9928 - Urea, tetraethyl-.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Urea, tetraethyl-. 721.9928 Section... Substances § 721.9928 Urea, tetraethyl-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as urea, tetraethyl- (PMN P-94-1017; CAS No. 1187-03-7) is...

  11. MINERALIZAÇÃO E VOLATILIZAÇÃO DO NITROGÊNIO DA VINHAÇA-15N NA PRESENÇA OU NÃO DE URÉIA E DE PALHA DE CANA- DE-AÇÚCAR MINERALIZATION AND VOLATILIZATION OF NITROGEN FROM VINASSE-15N IN THE PRESENCE OR ABSENCE OF UREA AND SUGARCANE TRASH

    Directory of Open Access Journals (Sweden)

    Vilma Maria Silva

    1999-01-01

    Full Text Available O N mineral e o N volatilizado derivado da vinhaça marcada com 15N foram determinados em amostras de dois solos (Podzólico Vermelho-Amarelo, arenoso - PV, e Latossolo Roxo, argiloso - LR do município de Piracicaba, SP, em experimento de laboratório. Os solos foram tratados com vinhaça marcada com 15N (V* na dose de 100 mg.kg-1 de N-vinhaça. Os tratamentos constaram da aplicação de vinhaça isoladamente (V*, de vinhaça e uréia (V*+U, de vinhaça e palha de cana-de-açúcar (V*+P, e de vinhaça mais uréia e palha (V*+U+P, e foram incubados por 7, 14, 21, 28 e 35 dias. As parcelas foram constituídas por 50 g de solo. As doses de incorporação de N-uréia e palha de cana-de-açúcar foram de 220 mg.kg-1 e 22 g.kg-1, respectivamente. As concentrações de N-NH4+ e N-NO3- no solo proveniente da vinhaça foram influenciadas pelo tipo de solo. A adição aos solos da uréia e da vinhaça promoveu uma maior disponibilidade de N-NH4+ e de N-NO3- proveniente da vinhaça. A adição de palha e de vinhaça não alterou as concentrações de N-NH4+ e de N-NO3- provenientes da vinhaça nos solos. A adição da palha, da uréia e da vinhaça não alterou as concentrações de N-NH4+ e as concentrações de N-NO3- aumentaram apenas no solo LR ao longo do tempo. As perdas por volatilização de N da vinhaça foram, em geral, crescentes, para todos os tratamentos no solo PV e mais elevadas (14 % que no solo LR (5%; neste, foram bem similares.The mineralized and volatilized nitrogen derived from vinasse labelled with 15N 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 sugarcane straw (V*+P; and vinasse with urea and sugarcane straw (V*+U+P. Vinasse, labelled with 15N (V* was applied at a rate of 100 mg.kg-1 of N

  12. Thyroid Hormone and Blood Metabolites Concentration of Gilts Superovulated Prior to Mating

    Directory of Open Access Journals (Sweden)

    RA Mege

    2009-05-01

    Full Text Available An experiment was conducted to study injection of pregnant mare serum gonadotrophin (PMSG and human chorionic gonadotrophin (hCG as superovulation agent in gilts to improve thyroid hormone and blood metabolites concentraton. In this experiment, 48 gilts were assigned into four groups of twelve gilts injected with PMSG dan hCG dose levels of 0, 600, 1200 and 1800 IU/gilt. Injections were conducted three days before estrus. During gestation, gilts were placed in colony pigpen. On days 15, 35, and 70 of gestation blood collected to determine triiodothyronine, tetraiodothyronine, tryglicerides, glucose, protein and bood nitrogen urea concentration. The resuts showed that superovulation dose levels of 600 to 1200 IU/gilt increased concentration of thyroid hormone (triiodothyronine and tetraiodothyronine/thyroxin and blood metabolite (triglycerides, glucose, and protein, but decreased blood urea nitrogen in gestation ages 15, 35, and 70 days. It is concluded that superovulation with dose of 600 to 1200 IU can improve of gilts metabolite hormone and blood metabolites. (Animal Production 11(2: 88-95 (2009Key Words: gilts, superovulation, metabolite hormone, blood metabolites

  13. Fermentasi Etanol Sari Buah Semu Jambu Mete (Anacardium occidentale L. oleh Zymomonas mobilis dengan Penambahan Urea

    Directory of Open Access Journals (Sweden)

    RATNA SETYANINGSIH

    2006-11-01

    Full Text Available Cashew present in abundant amount in Indonesia but they had not muchbeen exploited. This research was to study ethanol fermentation from cashew juice by Zymomonas mobilis using urea as nitrogen source. The aims of this research was to know the best urea concentration and optimum fermentation duration to produce the highest content of ethanol in ethanol fermentation from cashew juice by Z. mobilis. The urea concentration in media was prepared 0%; 0.2% and 0.4%. The media cashew juice + urea (100 mL was inoculated with 1 mL Z. mobilis 2x108 cell/mL. Initial pH, reducing sugar, amount of microorganism and concentration of ethanol was calculated everyday during 3 days. It could be concluded that 0.2% of urea produced the highest content of ethanol that was an amount 40.51%, followed by urea 0% was 30.59% and urea 0.4% was 25.63%. The optimum fermentation duration to produce the highest content of ethanol was 2 days.

  14. Blood

    Science.gov (United States)

    ... a reduced production of red blood cells, including: Iron deficiency anemia. Iron deficiency anemia is the most common type of anemia and ... inflammatory bowel disease are especially likely to have iron deficiency anemia. Anemia due to chronic disease. People with chronic ...

  15. Urea application promotes amino acid metabolism and membrane lipid peroxidation in Azolla.

    Directory of Open Access Journals (Sweden)

    Jiana Chen

    Full Text Available A pot experiment was conducted to evaluate the effect of urea on nitrogen metabolism and membrane lipid peroxidation in Azolla pinnata. Compared to controls, the application of urea to A. pinnata resulted in a 44% decrease in nitrogenase activity, no significant change in glutamine synthetase activity, 660% higher glutamic-pyruvic transaminase, 39% increase in free amino acid levels, 22% increase in malondialdehyde levels, 21% increase in Na+/K+- levels, 16% increase in Ca2+/Mg2+-ATPase levels, and 11% decrease in superoxide dismutase activity. In terms of H2O2 detoxifying enzymes, peroxidase activity did not change and catalase activity increased by 64% in urea-treated A. pinnata. These findings suggest that urea application promotes amino acid metabolism and membrane lipid peroxidation in A. pinnata.

  16. Urea application promotes amino acid metabolism and membrane lipid peroxidation in Azolla.

    Science.gov (United States)

    Chen, Jiana; Huang, Min; Cao, Fangbo; Pardha-Saradhi, P; Zou, Yingbin

    2017-01-01

    A pot experiment was conducted to evaluate the effect of urea on nitrogen metabolism and membrane lipid peroxidation in Azolla pinnata. Compared to controls, the application of urea to A. pinnata resulted in a 44% decrease in nitrogenase activity, no significant change in glutamine synthetase activity, 660% higher glutamic-pyruvic transaminase, 39% increase in free amino acid levels, 22% increase in malondialdehyde levels, 21% increase in Na+/K+- levels, 16% increase in Ca2+/Mg2+-ATPase levels, and 11% decrease in superoxide dismutase activity. In terms of H2O2 detoxifying enzymes, peroxidase activity did not change and catalase activity increased by 64% in urea-treated A. pinnata. These findings suggest that urea application promotes amino acid metabolism and membrane lipid peroxidation in A. pinnata.

  17. Radiation response of hydrated urea evaluated using 14N nuclear quadrupole resonance

    International Nuclear Information System (INIS)

    Hintenlang, D.E.

    1992-01-01

    In this paper Nitrogen-14 nuclear quadrupole resonance is utilized to detect radiation-induced changes in urea over the 0- to 300-Gy dose range. The spin-spin relaxation time exhibits a consistent change as a function of delivered dose in hydrated urea under exposure to 60 Co gamma radiation. No changes to the spin-spin relaxation time are observed in urea samples that were not hydrated. The radiation-induced changes are attributed to indirect radiation interactions with the water surrounding the urea molecules and are explained by the formation of subtle changes in the electron bonding configurations surrounding the 14 N nuclei, not major structural rearrangements. These subtle changes may provide additional insight into the effects of ionizing radiation on biological systems

  18. 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

  19. Treating agent for urea containing radioactive materials

    International Nuclear Information System (INIS)

    Ogawa, Hiroshi; Maki, Kentaro.

    1973-01-01

    Object: To add a coagulant into urea containing radioactive material to precipitate and remove the radioactive material in the urea. Structure: Iodosalt is added into urea and next, a mixed reagent in which silver ion or silver acetic ion and iron hydroxide precipitation or ferrite ion coexist is added therein. The urea is treated to have a sufficient alkaline, after which it is introduced into a basket type centrifuge formed with a filter layer in combination of an upper glass fiber layer and a lower active carbon layer. The treating agent can uniformly remove radioactive ion and radioactive chelate within urea containing inorganic salt and various metabolites. (Nakamura, S.)

  20. IL-6 has no acute effect on the regulation of urea synthesis in vivo in rats

    DEFF Research Database (Denmark)

    Thomsen, Karen; Aagaard, Niels Kristian; Grønbæk, Henning

    2011-01-01

    Clinical or experimentally induced, active inflammation up-regulates the in vivo capacity of urea synthesis (CUNS), which promotes nitrogen removal from the body and metabolic catabolism. We have shown that tumor necrosis factor a (TNF-a) up-regulates CUNS and increases interleukin 6 expression (IL......-6) within hours of administration. The described effect of TNF-a on nitrogen homeostasis may, therefore, depend on IL-6....

  1. Nitrogen metabolism and microbial production of dairy cows fed sugarcane and nitrogen compounds

    OpenAIRE

    Gonçalves,Geógenes da Silva; Pedreira,Marcio dos Santos; Pereira,Mara Lúcia Albuquerque; Santos,Dimas Oliveira; Souza,Dicastro Dias de; Porto Junior,Antonio Ferraz

    2014-01-01

    The aim of this study was to evaluate the effect of dairy cow diets containing two different sources of urea on nitrogen metabolism and microbial synthesis. Eight crossbred cows were confined and distributed in two 4x4 Latin: FS - soybean meal (control), conventional urea (UC) 100%; ULL 44 UC = 56% / 44% ULL, ULL 88 UC = 12% / 88% ULL. Diets were offered to animals during 21 days with 14 days of adaptation. The N intake, retained nitrogen balance, nitrogen excretion in milk, urine, feces and ...

  2. Full protein alimentation and nitrogen equilibrium in a renal failure patient treated with continuous hemodiafiltration: a case report of 67 days of continuous hemodiafiltration.

    Science.gov (United States)

    Reynolds, H N; Borg, U; Frankenfield, D

    1992-01-01

    Standard care for patients with renal failure while in an intensive care unit involves traditional hemodialysis or peritoneal dialysis and protein restriction. We present a case of a patient with renal failure supported with continuous arteriovenous hemofiltration with dialysis (CAVH-D) who was given full protein alimentation. Total daily urea clearance was measured from the CAVH-D output. Protein load was 196 +/- 34 g/day while receiving total parenteral nutrition and 164 +/- 30 g/day while receiving enteral alimentation. Serum blood urea nitrogen was controlled between 40 and 75 mg/dL, except during septic episodes. Nitrogen balance was estimated based upon known alimentation protein load and measurable and estimated nitrogenous losses. The patient was potentially in nitrogen equilibrium during most of the dialysis period. The cumulative nitrogen balance was positive by 5.2 g after 67 days of dialysis. Volume of alimentation was 3.49 +/- 0.7 liters/day. With CAVH-D, the renal failure patient can receive full alimentation without volume or protein load limitations. Furthermore, nitrogen balances can be estimated easily while the patient is on CAVH-D.

  3. Green urea synthesis catalyzed by hematite nanowires in magnetic field

    International Nuclear Information System (INIS)

    Yahya, Noorhana; Qureshi, Saima; Rehman, Zia ur; Alqasem, Bilal; Fai Kait, Chong

    2017-01-01

    The catalytic activity of hematite (α-Fe 2 O 3 ) nanowires under the influence of magnetic field on urea synthesis is considered green. The adsorption and subsequent dissociative reaction of hydrogen, nitrogen and carbon dioxide gases on the α-Fe 2 O 3 (111) nanowires were investigated using the density functional theory (DFT) method. The average adsorption energy is −4.12 kcal/mole at different sites. The adsorption of gases resulted in a difference in density and net spin of electrons from 68 to 120 and 0–21 respectively. In addition, it induces magnetic moment value of 36.33 µB, which confirms the enhanced magnetic behaviour of hematite. α-Fe 2 O 3 nanowires (NWs) synthesized by heating iron wire in a box furnace at (750−800) °C and as synthesized α-Fe 2 O 3 nanoparticles (NPs) were received to use as a catalyst in the magnetic reaction of urea synthesis. X-ray Diffractometer (XRD) confirms the peaks of rhombohedral structure of α-Fe 2 O 3 and Raman spectrum analyses confirms the α-Fe 2 O 3 peaks at 410 cm −1 , 500 cm −1 and 616 cm −1 . The needle-like shape of hematite nanowires with length ranging from 16–25) μm and diameter from 74 to 145 nm confirmed by Field emission scanning electron microscopy (FESEM). The magnetic properties of the nanowires exhibited different levels of saturation magnetization, for α-Fe 2 O 3 perpendicularly aligned direction (13.18 emu/g) and random direction (10.73 emu/g). Urea synthesis was done under magnetic field ranges from 0.0 to 2.5 T. The activation energy of α-Fe 2 O 3 NWs for urea production is lower than NPs in the range of 0–1 T, whereas it is reversed for higher magnetic induction values. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of urea at the peaks of 1690–1600 cm −1 . This green urea employing magnetically induced method could be a contender to the Haber-Bosch process currently used by the current industry which utilizes high temperature and high pressure

  4. Nutritive value of ensiled pig excreta, poultry litter or urea with ...

    African Journals Online (AJOL)

    The objective of this study was to evaluate the nutritive value of maize stover silage diets containing pig excreta (PE), poultry litter (PL) or urea as nitrogen (N) sources, and sugarcane molasses (MOL) or bakery by-products (BBP) as energy sources. The study was designed as a 6 × 6 Latin square with six ruminal ...

  5. Mineral commodity profiles: nitrogen

    Science.gov (United States)

    Kramer, Deborah A.

    2004-01-01

    contributed the remaining 4 percent (International Fertilizer Industry Association, 2003b, p. 1-4). In 2002, world ammonia exports were 13.1 Mt of contained nitrogen. Trinidad and Tobago (22 percent), Russia (18 percent), Ukraine (10 percent), and Indonesia (7 percent) accounted for 57 percent of the world total. The largest importing regions were North America with 36 percent of the total followed by Western Europe with 23 percent and Asia with 22 percent (International Fertilizer Industry Association, 2003b, p. 5L-11). In 2002, world urea production was 51.4 Mt of contained nitrogen, and exports were 12.0 Mt of contained nitrogen. China and India, which were the two largest producing countries, accounted for 48 percent of world production. The United States and Canada produced about 10 percent of the total. Russia and Ukraine together accounted for 28 percent of total urea exports; Central America and South America, 27 percent; and Asia, North America, and Western Europe, 10 percent each. North America accounted for 36 percent of the total urea imports; Western Europe, 23 percent; and Asia, 22 percent (International Fertilizer Industry Association, 2003f, p. 1-15). Ammonia production capacity in North America and Western Europe is projected to decline through 2004, and capacity in other world regions is projected to increase. Fluctuating natural gas prices are mainly responsible for the capacity decline in North America. Ammonia production capacity is continuing to shift to world regions that have abundant sources of natural gas, and away from those where costs (raw material, labor, environmental compliance) are higher.

  6. The influence of parenteral nitrogen feeding on free amino acid composition of blood serum and hepatic tissue of irradiated rats

    International Nuclear Information System (INIS)

    Mil'ko, V.I.; Kirichenko, A.V.; Chalaya, L.A.

    1985-01-01

    A considerable change in the free am ino acid composition of blood serum and hepatic tissued was noted on the 7th and 14th days following total-body X-irradiation of rats with a dose of 2.9 Gy. The total free amino acid content of blood serum increased and that of hepatic tissue decreased by 85% (on an average) as compared to the intact controls. Quantitative changes in the content of individual amino acids were analysed. Polyamine injected enterally for 7 days and parenterally for 3 days after irradiation a the elimination of the postirradiation changes in the amino acid balance

  7. Greener on the Other Side: How Increased Urea Use may Promote Cyanobacterial Blooms

    Science.gov (United States)

    Erratt, K. J.; Creed, I. F.; Trick, C. G.

    2017-12-01

    The frequency of freshwater cyanobacterial blooms is on the rise in temperate regions around the world. The widespread use of chemical fertilizers linked to modern agricultural practices has enhanced the fertility of surface waters promoting the expansion of cyanobacteria dominated harmful algal blooms. While phosphorus (P) has been recognized as the principal agent regulating phytoplankton productivity in inland waters, elevated P is not the universal trigger for bloom initiation. P fertilizer applications across the globe have been outpaced by nitrogen (N) fertilizer use. Not only has the load of N entering surface waters increased, but its chemical composition has been altered. The use of inorganic-N fertilizers has been waned in favor of urea-based products, with urea now accounting for more than half of total N-fertilizer applications worldwide. This contemporary shift in fertilizer usage has coincided with the rise of cyanobacteria dominated harmful algal blooms in freshwaters. Here, we examined the relative success of urea as a N-source relative to inorganic N forms (NO3-, NH4+) for three common bloom-forming species of cyanobacteria: Microcystis aeruginosa, Dolichospermum flos-aque, and Synechococcus sp. We found that (1) urea was consistently drawdown more rapidly relative to inorganic N substrates, suggesting that cyanobacteria exhibit a preference for urea over inorganic N forms; (2) cyanobacteria consume urea in excess of cellular requirements; and (3) urea may offer cyanobacteria a competitive edge over eukaryotic algae by enhancing light absorption capabilities. As we push forward into the 21st century, our reliance on urea-based fertilizers is projected to escalate and it is critical that we understand the unintended consequences urea discharge could be having on receiving freshwaters.

  8. Transformation of fertilizer nitrogen in soil

    International Nuclear Information System (INIS)

    Soechting, H.

    1980-01-01

    Pot experiments are described in which the transformations between nitrogen added as fertilizer urea, plant-assimilated nitrogen, and different chemical fractions of soil or added straw nitrogen were studied with 15 N as a tracer. The data indicated that: (a) The transformation of added fertilizer nitrogen to immobilized amide nitrogen is decreased with added decomposable organic carbon. The transformation to immobilized α-amino N is increased, on the other hand, by the addition of decomposable organic carbon. (b) The freshly immobilized amide nitrogen is more readily remineralized than the α-amino form. The immobilization of added nitrogen continues in the presence of growing plants. (c) Mineralization of nitrogen added as 15 N-labelled straw is also increased with increasing fertilizer-nitrogen additions. (author)

  9. Effect of coated urea and non-coated urea on grain yield, N uptake and N distribution in different parts of maize

    International Nuclear Information System (INIS)

    Ren Yi; Li Guihua; Zhao Linping; Zhang Shuxiang

    2011-01-01

    In order to regulate nitrogen metabolism with nitrogen application rate and to increase nitrogen use efficiency, an isotopic method was used to compare grain yield, biomass and nitrogen use efficiency of coated urea (CU) to those of non-coated urea (U) at the N application rates of 0, 100, 150 and 225 kg/hm 2 . Results showed that CU significantly increased maize N uptake from 15 N fertilizer and aboveground biomass. The nitrogen use efficiency ( 15 NUE) of CU was 13.3-21.4% greater than that of U. There was a significant different of fertilizer 15 N uptake between CU and U in maize parts. And N uptake of CU treatment followed the order of seed > leaves > straws > cob > husk, while N uptake of U treatment was in the order of seed > straws > leaves > cob > husk. The N uptake of maize parts by both CU and U followed the same order when non-isotopic method was applied. No significant variations were observed among treatments in N uptake, Nitrogen Harvest Index and grain yield. The reason maybe that low soil temperatures (< 10 ℃) from the fourth week of October to next April reduced N uptake of winter wheat, therefore, residual NO3-N in cultivated soil layer was high after harvest. Thus, maize N uptake was more dependent on the shoot growth potential than fertilizer amount and types under high amount of available nitrogen. (authors)

  10. Treatment of the syndrome of inappropriate secretion of antidiuretic hormone by urea.

    Science.gov (United States)

    Decaux, G; Brimioulle, S; Genette, F; Mockel, J

    1980-07-01

    Recent data have shown the role of urea in the urinary concentrating mechanism. We studied the effects of exogenous urea administration in hyponatremia associated with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). In 20 patients with SIADH, we observed a positive correlation between serum sodium and blood urea levels (r = 0.65; p less than 0.01). In one patient with an oat cell carcinoma and SIADH-induced hyponatremia, we observed the same positive correlation (r = 0.80; p less than 0.01) but also a negative one between the excreted fraction of filtered sodium and urinary urea (r = -0.67; p less than 0.001). The short-term administration of low doses of urea (4 to 10 g) resulted in correcting the "salt-losing" tendency of this patient. Longer term administration of high doses of urea (30 g/day) was attempted with the same patient as well as with a healthy volunteer subject with Pitressin-induced SIADH. in both patients, urea treatment lowered urinary sodium excretion as long as hyponatremia was significant (less than 130 meq/liter). Urea treatment also induced a persistent osmotic diuresis, allowing a normal daily intake of water despite SIADH. This was clearly shown during the long-term treatment of a third patient with SIADH who was taking 30 g urea/day during 11 weeks. It is concluded that urea is a good alternative in the treatment of patients with SIADH who presented with persistent hyponatremia despite the restriction of water intake.

  11. Dynamic of N fertilizers: urea (15 N) and aqua ammonia (15 N) incorporated to the sugar cane soil. Final report

    International Nuclear Information System (INIS)

    Trivelin, P.C.O.

    1988-05-01

    The dynamic of N fertilizers, urea and aqua ammonia, in the soil of sugar cane crops are studied with an emphasis on the horizontal and vertical moving. The nitrogen routing from urea and aqua ammonia sources, by isotopic technique with 15 N in relation to the leaching, volatilization and extraction by the cultivation and residue of N immobilized manure in the soil with sugar cane plantation is also analysed. (C.G.C.)

  12. Evaluation of a point-of-care blood analyzer and determination of reference ranges for blood parameters in rockfish.

    Science.gov (United States)

    Harrenstien, Lisa A; Tornquist, Susan J; Miller-Morgan, Timothy J; Fodness, Brian G; Clifford, Kevin E

    2005-01-15

    To compare values of blood parameters in rockfish obtained by use of a point-of-care portable blood analyzer with values determined by a veterinary diagnostic laboratory, calculate reference ranges for various blood parameters in black rockfish, and compare values of blood parameters in clinically normal fish with those of fish with clinical abnormalities. Prospective study. 41 captive adult black rockfish (Sebastes melanops) and 4 captive adult blue rockfish (Sebastes mystinus). Rockfish were anesthetized with tricaine methanesulfonate for collection of blood samples. Heparinized blood samples were immediately analyzed with a point-of-care analyzer. Blood sodium, potassium, chloride, urea nitrogen, and glucose concentrations; Hct; pH; partial pressure of carbon dioxide; total carbon dioxide concentration; bicarbonate concentration; base excess; and hemoglobin concentration were determined. A microhematocrit technique was used to determine PCV, and a refractometer was used to estimate total plasma protein concentration. Paired heparinized blood samples were transported to a veterinary diagnostic laboratory for analyses. Data obtained with the point-of-care analyzer were reproducible; however, values for most blood parameters were significantly different from those obtained by the veterinary diagnostic laboratory. Fish with poor body condition had several blood parameter values that were lower than corresponding values in clinically normal fish. Point-of-care blood analyses may prove useful in rockfish. Point-of-care data for a large number of clinically normal fish must be obtained for reference ranges to be calculated, and further assessments of clinically abnormal fish are necessary to determine the relevance of the data.

  13. Urea in Weaver Ant Feces: Quantification and Investigation of the Uptake and Translocation of Urea in Coffea Arabica

    DEFF Research Database (Denmark)

    Vidkjær, Nanna Hjort; Wollenweber, Bernd; Jensen, Karl-Martin Vagn

    2016-01-01

    Weaver ants are tropical insects that nest in tree canopies, and for centuries these ants have been used for pest control in tropical orchards. Trees hosting weaver ants might benefit not only from the pest protective properties of these insects but also an additional supply of nutrients from ant...... investigate the interactions of weaver ants with the host plants with respect to plant nutrition. Here, we report the identification and quantification of urea, a highly effective foliar nutrient present in the fecal depositions of O. smaragdina. Feces samples obtained from six O. smaragdina colonies were....... The results clearly demonstrated that fecal urea was not only assimilated but also translocated within the plant. This evidence strongly supports the hypothesis that the fecal urea of weaver ants is a source of nitrogen for the host trees. Thus, weaver ant feces likely contribute to an improved nutritional...

  14. 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.

  15. Urochloa ruziziensis responses to sources and doses of urea

    Directory of Open Access Journals (Sweden)

    João E. S. Lima

    2016-05-01

    Full Text Available ABSTRACT The use of products that promote reduction of nitrogen (N losses from the urea fertilizer can contribute to increasing its use efficiency in forage grasses. This study aimed to evaluate the effects of N sources and doses on the growth of Urochloa ruziziensis. The experiment was carried out in the growing season of 2007/2008 in Santo Antônio de Goiás-GO, in a Brazilian Oxisol. A completely randomized block was used, with four replicates in a factorial scheme, corresponding to two N sources (conventional urea and urea with urease inhibitor and five N doses (0, 50, 100, 200 and 300 kg ha-1, divided into equal applications in five periods (Nov 14 to Dec 13, Dec 14 to Jan 12, Jan 13 to Feb 11 - rainy season, Mar 24 to Apr 22 and Jul 10 to Aug 08 - dry season. The effects of the treatments were evaluated for: shoot dry matter, tiller density, total N content in the leaves and relative chlorophyll content. N fertilizer sources did not affect the evaluated variables; however, N fertilization allowed linear increases in all variables with higher values during the rainy period. The relative chlorophyll content in U. ruziziensis had positive correlation with its dry matter productivity.

  16. Osmolality - blood

    Science.gov (United States)

    ... water loss Poisoning from harmful substances such as ethanol , methanol , or ethylene glycol Problems producing urine In ... may be due to: Diabetes insipidus High blood sugar level ( hyperglycemia ) High level of nitrogen waste products ...

  17. Ammonia volatilization and yield components after application of polymer-coated urea to maize

    Directory of Open Access Journals (Sweden)

    Eduardo Zavaschi

    2014-08-01

    Full Text Available A form of increasing the efficiency of N fertilizer is by coating urea with polymers to reduce ammonia volatilization. The aim of this study was to evaluate the effect of polymer-coated urea on the control of ammonia volatilization, yield and nutritional characteristics of maize. The experiment was carried out during one maize growing cycle in 2009/10 on a Geric Ferralsol, inUberlândia, MG, Brazil. Nitrogen fertilizers were applied as topdressing on the soil surface in the following urea treatments: polymer-coated urea at rates of 45, 67.5 and 90 kg ha-1 N and one control treatment (no N, in randomized blocks with four replications. Nitrogen application had a favorable effect on N concentrations in leaves and grains, Soil Plant Analysis Development (SPAD chlorophyll meter readings and on grain yield, where as coated urea had no effect on the volatilization rates, SPAD readings and N leaf and grain concentration, nor on grain yield in comparison to conventional fertilization.

  18. 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...

  19. Profile of sodium phenylbutyrate granules for the treatment of urea-cycle disorders: patient perspectives.

    Science.gov (United States)

    Peña-Quintana, Luis; Llarena, Marta; Reyes-Suárez, Desiderio; Aldámiz-Echevarria, Luis

    2017-01-01

    Urea-cycle disorders are a group of rare hereditary metabolic diseases characterized by deficiencies of one of the enzymes and transporters involved in the urea cycle, which is necessary for the removal of nitrogen produced from protein breakdown. These hereditary metabolic diseases are characterized by hyperammonemia and life-threatening hyperammonemic crises. Pharmacological treatment of urea-cycle disorders involves alternative nitrogen-scavenging pathways. Sodium benzoate combines with glycine and phenylacetate/phenylbutyrate with glutamine, forming, respectively, hippuric acid and phenylacetylglutamine, which are eliminated in the urine. Among the ammonia-scavenging drugs, sodium phenylbutyrate is a well-known long-term treatment of urea-cycle disorders. It has been used since 1987 as an investigational new drug, and was approved for marketing in the US in 1996 and the EU in 1999. However, sodium phenylbutyrate has an aversive odor and taste, which may compromise patients' compliance, and many patients have reported difficulty in taking this drug. Sodium phenylbutyrate granules are a new tasteless and odor-free formulation of sodium phenylbutyrate, which is indicated in the treatment of urea-cycle disorders. This recently developed taste-masked formulation of sodium phenylbutyrate granules was designed to overcome the considerable issues that taste has on adherence to therapy. Several studies have reported the clinical experience of patients with urea-cycle disorders treated with this new tasteless formulation of sodium phenylbutyrate. Analysis of the data indicated that this taste-masked formulation of sodium phenylbutyrate granules improved quality of life for urea-cycle disorder patients. Furthermore, a postmarketing report on the use of the product has confirmed the previous observations of improved compliance, efficacy, and safety with this taste-masked formulation of sodium phenylbutyrate.

  20. 21 CFR 184.1923 - Urea.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Urea. 184.1923 Section 184.1923 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1923 Urea. (a) Urea (CO(NH2)2, CAS Reg. No. 57-13-6) is the diamide of...

  1. Nutritional factors influencing milk urea in buffaloes

    Directory of Open Access Journals (Sweden)

    V. Proto

    2011-03-01

    Full Text Available Urea is the primary form in which N is excreted in ruminants. Milk urea (MU content was introduced as a means to monitor the efficiency of protein utilisation in dairy cattle (Baker et al., 1995; Roseler et al., 1993; Bertoni, 1995. In this study the effect of some nutrition factors on MU content in buffalo herds was analysed in order to examine the possibility that protein nutrition could be monitored by means of milk urea at herd level........

  2. Biodegradation of Ethyl Carbamate and Urea with Lysinibacillus sphaericus MT33 in Chinese Liquor Fermentation.

    Science.gov (United States)

    Cui, Kaixiang; Wu, Qun; Xu, Yan

    2018-02-14

    It is important to reduce the concentration of ethyl carbamate (EC) in fermented foods. However, controlling the formation of EC and its precursor urea is difficult in spontaneous food fermentation because urea is a natural product of nitrogen metabolism. Biodegradation is a better solution to reduce the concentration of EC. This study aimed to reduce the concentration of EC in Chinese liquor via an indigenous strain Lysinibacillus sphaericus MT33. This strain produced urethanase (940 U/L) and urease (1580 U/L) and degraded 76.52% of EC and 56.48% of urea. After inoculation in liquor fermentation, the maximal relative abundance of Lysinibacillus increased from 0.02% to 8.46%, the final EC and urea contents decreased by 41.77% and 28.15%. Moreover, the concentration of EC decreased by 63.32% in liquor. The negative correlation between abundance of Lysinibacillus and contents of EC and urea indicated the effect of L. sphaericus on EC and urea degradation.

  3. 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.

  4. Green urea synthesis catalyzed by hematite nanowires in magnetic field

    Science.gov (United States)

    Yahya, Noorhana; Qureshi, Saima; Rehman, Zia ur; Alqasem, Bilal; Fai Kait, Chong

    2017-04-01

    The catalytic activity of hematite (α-Fe2O3) nanowires under the influence of magnetic field on urea synthesis is considered green. The adsorption and subsequent dissociative reaction of hydrogen, nitrogen and carbon dioxide gases on the α-Fe2O3 (111) nanowires were investigated using the density functional theory (DFT) method. The average adsorption energy is -4.12 kcal/mole at different sites. The adsorption of gases resulted in a difference in density and net spin of electrons from 68 to 120 and 0-21 respectively. In addition, it induces magnetic moment value of 36.33 μB, which confirms the enhanced magnetic behaviour of hematite. α-Fe2O3 nanowires (NWs) synthesized by heating iron wire in a box furnace at (750-800) °C and as synthesized α-Fe2O3 nanoparticles (NPs) were received to use as a catalyst in the magnetic reaction of urea synthesis. X-ray Diffractometer (XRD) confirms the peaks of rhombohedral structure of α-Fe2O3 and Raman spectrum analyses confirms the α-Fe2O3 peaks at 410 cm-1, 500 cm-1 and 616 cm-1. The needle-like shape of hematite nanowires with length ranging from 16-25) μm and diameter from 74 to 145 nm confirmed by Field emission scanning electron microscopy (FESEM). The magnetic properties of the nanowires exhibited different levels of saturation magnetization, for α-Fe2O3 perpendicularly aligned direction (13.18 emu/g) and random direction (10.73 emu/g). Urea synthesis was done under magnetic field ranges from 0.0 to 2.5 T. The activation energy of α-Fe2O3 NWs for urea production is lower than NPs in the range of 0-1 T, whereas it is reversed for higher magnetic induction values. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of urea at the peaks of 1690-1600 cm-1. This green urea employing magnetically induced method could be a contender to the Haber-Bosch process currently used by the current industry which utilizes high temperature and high pressure.

  5. A Greenhouse Assay on the Effect of Applied Urea Amount on the Rhizospheric Soil Bacterial Communities.

    Science.gov (United States)

    Shang, Shuanghua; Yi, Yanli

    2015-12-01

    The rhizospheric bacteria play key role in plant nutrition and growth promotion. The effects of increased nitrogen inputs on plant rhizospheric soils also have impacted on whole soil microbial communities. In this study, we analyzed the effects of applied nitrogen (urea) on rhizospheric bacterial composition and diversity in a greenhouse assay using the high-throughput sequencing technique. To explore the environmental factors driving the abundance, diversity and composition of soil bacterial communities, the relationship between soil variables and the bacterial communities were also analyzed using the mantel test as well as the redundancy analysis. The results revealed significant bacterial diversity changes at different amounts of applied urea, especially between the control treatment and the N fertilized treatments. Mantel tests showed that the bacterial communities were significantly correlated with the soil nitrate nitrogen, available nitrogen, soil pH, ammonium nitrogen and total organic carbon. The present study deepened the understanding about the rhizospheric soil microbial communities under different amounts of applied urea in greenhouse conditions, and our work revealed the environmental factors affecting the abundance, diversity and composition of rhizospheric bacterial communities.

  6. GROWTH, PHYSIOLOGY AND YIELD OF FORMOSA ‘PAPAYA’ CULTIVATED UNDER DIFFERENT DOSES OF COATED AND CONVENTIONAL UREA

    Directory of Open Access Journals (Sweden)

    GABRIEL BARBOSA DA SILVA JÚNIOR

    2016-01-01

    Full Text Available Mineral fertilizer management is one of the most important agronomic techniques applied in papaya cultivation, which generally extracts large amounts of nutrients from soil, especially nitrogen. This study aimed to assess the phytotechnical and physiological attributes and yield of „Formosa‟ papaya hybrid Caliman 01 as a function of different doses of coated and conventional urea in the region of Bom Jesus - PI, Brazil. The treatments were arranged in a factorial scheme (2 × 4 and distributed in a randomized block design with four replications, corresponding to 2 nitrogen sources (coated urea, 43% of N; and conventional urea, 45% of N and 4 doses nitrogen (350, 440, 530 and 620 g per plant. The N doses used corresponded to 80, 100, 120 and 140% of the nitrogen fertilization. It was used six plants per plot with two row borders, totaling 192 plants cultivated in the field. It was assessed the intercepted photosynthetically active radiation (int.PAR, radiation interception efficiency (PAREff., leaf area index (LAI, plant height, stem diameter and yield. The coated urea promotes a higher growth and yield of „Formosa‟ papaya compared to the conventional urea. The application of 1.0 g of coated N promotes the production of 2.87 g of fruit per hectare while the application of 1.0 g of conventional N produces only 1.89 g of fruit per hectare, showing that the source of polymerized N increases the use efficiency of N applied to soil.

  7. Orphan drugs in development for urea cycle disorders: current perspectives

    Directory of Open Access Journals (Sweden)

    Häberle J

    2014-09-01

    Full Text Available Johannes Häberle,1 Shawn E McCandless2 1Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland; 2Center for Human Genetics, University Hospitals Case Medical Center, and Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA Abstract: The urea cycle disorders are caused by deficiency of one of the six hepatic enzymes or two transporters involved in detoxification of ammonia. The resulting hyperammonemia causes severe brain injury unless aggressive steps are taken to reduce the accumulation of ammonia, which is thought to be the most toxic metabolite. This review describes the current state of chronic management of urea cycle disorders, focusing on new and emerging therapies. Management strategies include the mainstay of treatment, namely dietary protein restriction and supplementation with l-arginine or l-citrulline. Several currently approved medications utilize and enhance alternative pathways of waste nitrogen excretion (sodium benzoate, sodium phenylacetate, sodium phenylbutyrate in several formulations, and glycerol phenylbutyrate, working through conjugation of the drug to either glycine (in the case of benzoate or glutamine, the products of which are excreted in the urine. Carglumic acid activates the first committed step of conversion of ammonia to urea, carbamoylphosphate synthetase, and thus effectively treats defective synthesis of the endogenous activator, N-acetylglutamate, whether due to genetic defects or biochemical inhibition of the N-acetylglutamate synthase enzyme. Approaches to neuroprotection during episodes of hyperammonemia are discussed, including the use of controlled hypothermia (brain cooling, as well as proposed, but as yet untested, pharmacologic therapies. Finally, cell-based therapies, including liver transplantation, infusion of fresh or cryopreserved hepatocytes, use of stem cells, and new approaches to gene

  8. Stability and Application of Reactive Nitrogen and Oxygen Species-Induced Hemoglobin Modifications in Dry Blood Spots As Analyzed by Liquid Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    Chen, Hauh-Jyun Candy; Fan, Chih-Huang; Yang, Ya-Fen

    2016-12-19

    Dried blood spot (DBS) is an emerging microsampling technique for the bioanalysis of small molecules, including fatty acids, metabolites, drugs, and toxicants. DBS offers many advantages as a sample format including easy sample collection and cheap sample shipment. Hemoglobin adducts have been recognized as a suitable biomarker for monitoring chemical exposure. We previously reported that certain modified peptides in hemoglobin derived from reactive chlorine, nitrogen, and oxygen species are associated with factors including smoking, diabetes mellitus, and aging. However, the stability of these oxidation-induced modifications of hemoglobin remains unknown and whether they can be formed artifactually during storage of DBS. To answer these questions, globin extracted from the DBS cards was analyzed, and the stability of the modifications was evaluated. After storage of the DBS cards at 4 °C or room temperature up to 7 weeks, we isolated globin from a quarter of the spot every week. The extents of 11 sites and types of post-translational modifications (PTMs), including nitration and nitrosylation of tyrosine and oxidation of cysteine and methionine residues, in human hemoglobin were measured in the trypsin digest by nanoflow liquid chromatography-nanospray ionization tandem mass spectrometry (nanoLC-NSI/MS/MS) using selected reaction monitoring. The extents of all these PTMs are stable within 14 days when stored on DBS at room temperature and at 4 °C, while those from direct extraction of fresh blood are stable for at least 8 weeks when stored as an aqueous solution at -20 °C. Extraction of globin from a DBS card is of particular importance for hemolytic blood samples. To our knowledge, this is the first report on the stability of oxidative modifications of hemoglobin on DBSs, which are stable for 14 days under ambient conditions (room temperature, in air). Therefore, it is feasible and convenient to analyze these hemoglobin modifications from DBSs in studies

  9. 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

  10. Treatment of liquid effluents from an ammonia/urea/sulphur plant

    Energy Technology Data Exchange (ETDEWEB)

    Padula, R.C.; Amabal, S.P.

    1979-01-01

    The effluent treatment processes planned for a new 1500 ton/day urea, 1200 ton/day ammonia plant in Brazil, based on the two-stage reaction of ammonia and carbon dioxide to form urea and on the catalytic hydrogenation of nitrogen to ammonia, will include the steps of equalization, flocculation, flotation, nitrification, sedimentation, denitrification, rapid aeration, further settlement, filtration, and discharge to a river. Sludge will be chemically conditioned as needed, and will be thickened, filtered, and disposed of by land application. There will be considerable recycling of nutrients.

  11. Voltamperometric Discrimination of Urea and Melamine Adulterated Skimmed Milk Powder

    Directory of Open Access Journals (Sweden)

    Eduardo Cortón

    2012-09-01

    Full Text Available Nitrogen compounds like urea and melamine are known to be commonly used for milk adulteration resulting in undesired intoxication; a well-known example is the Chinese episode occurred in 2008. The development of a rapid, reliable and economic test is of relevance in order to improve adulterated milk identification. Cyclic voltammetry studies using an Au working electrode were performed on adulterated and non-adulterated milk samples from different independent manufacturers. Voltammetric data and their first derivative were subjected to functional principal component analysis (f-PCA and correctly classified by the KNN classifier. The adulterated and non-adulterated milk samples showed significant differences. Best results of prediction were obtained with first derivative data. Detection limits in milk samples adulterated with 1% of its total nitrogen derived from melamine or urea were as low as 85.0 mg·L−1 and 121.4 mg·L−1, respectively. We present this method as a fast and robust screening method for milk adulteration analysis and prevention of food intoxication.

  12. Nitrogen fertilization efficiency with Urea ({sup 15}N) in Brachiaria brizantha cv. Marandu associated with split application of ordinary superphosphate and potassium chloride; Eficiencia da fertilizacao nitrogenada com ureia ({sup 15}N) em Brachiaria brizantha cv. Marandu associada ao parcelamento de superfosfato simples e cloreto de potassio

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, P.P.A. [EMBRAPA, Pirassununga, SP (Brazil). Centro Nacional de Pesquisa de Gado e Leite]. E-mail: ppaolive@cnpgl.embrapa.br; Trivelin, P.C.O. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Isotopos Estaveis]. E-mail: pcotrive@cena.usp.br; Oliveira, W.S. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Biologia Celular e Molecular]. E-mail: wsolivei@carpa.ciagri.usp.br

    2003-08-01

    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 {sup 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)

  13. 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

  14. Absorption and utilization of fertilizer-N and soil-N with mixed application of straw and urea by rice

    International Nuclear Information System (INIS)

    Zhang Xinwei; Liu Feng; Ye Shuya; Zhu Hongbin; Ye Chengxin

    1996-01-01

    The nitrogen absorption of mixed application of straw and urea by rice was studied by using 15 N isotope tracing technique. The results show that the sole application of straw would result in biological immobilization of available soil N. The insufficient N supply was the limiting factor for rice tiller and spikelets development. Mixed use of straw and urea obviously improved nitrogen supply from both fertilizer and soil, which in turn, promoted the yield of growing rice and increased the soil fertility and productivity of later crop

  15. Enhanced Productivity of a Lutein-Enriched Novel Acidophile Microalga Grown on Urea

    Directory of Open Access Journals (Sweden)

    Carlos Vilchez

    2010-12-01

    Full Text Available Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of b-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related industries. The acidic culture medium (pH < 2.5 that prevents outdoor cultivation from non-desired microorganism growth is one of the main advantages of acidophile microalgae production. Conversely, acidophile microalgae growth rates are usually very low compared to common microalgae growth rates. In this work, we show that mixotrophic cultivation on urea efficiently enhances growth and productivity of an acidophile microalga up to typical values for common microalgae, therefore approaching acidophile algal production towards suitable conditions for feasible outdoor production. Algal productivity and potential for carotenoid accumulation were analyzed as a function of the nitrogen source supplied. Several nitrogen conditions were assayed: nitrogen starvation, nitrate and/or nitrite, ammonia and urea. Among them, urea clearly led to the best cell growth (~4 ´ 108 cells/mL at the end of log phase. Ammonium led to the maximum chlorophyll and carotenoid content per volume unit (220 mg·mL-1 and 35 mg·mL-1, respectively. Interestingly, no significant differences in growth rates were found in cultures grown on urea as C and N source, with respect to those cultures grown on nitrate and CO2 as nitrogen and carbon sources (control cultures. Lutein accumulated up to 3.55 mg·g-1 in the mixotrophic cultures grown on urea. In addition, algal growth in a shaded culture revealed the first evidence for an active xanthophylls cycle operative in acidophile microalgae.

  16. Peak hyperammonemia and atypical acute liver failure: The eruption of an urea cycle disorder during hyperemesis gravidarum.

    Science.gov (United States)

    Weiss, Nicolas; Mochel, Fanny; Rudler, Marika; Demeret, Sophie; Lebray, Pascal; Conti, Filomena; Galanaud, Damien; Ottolenghi, Chris; Bonnefont, Jean-Paul; Dommergues, Marc; Bernuau, Jacques; Thabut, Dominique

    2017-09-20

    Inborn urea cycle disorders are under-recognised metabolic causes of hyperammonemia in adults. A 28-year-old primigravida, seven weeks pregnant, affected by hyperemesis gravidarum developed acute liver injury (ALI) and then acute liver failure (ALF) in less than 48 h. Because the patient developed atypical features, especially mildly elevated aminotransferases contrasting with very high blood ammonia levels (281 μmol/L), concomitant with normal serum creatinine, an inborn error of metabolism was suspected. We performed emergency metabolic analyses, stopped all protein intake and started with intravenous (i.v.) high caloric intake, nitrogen scavenger drugs and haemodialysis. The neurological and hepatic status of the patient quickly improved together with normalisation of her ammonemia levels. High plasma glutamine and urinary orotic acid, alongside low plasma arginine, citrulline and ornithine were suggestive of an ornithine transcarbamylase deficiency, later confirmed by molecular analyses. Foetal sex was female, as determined by foetal DNA analysis in maternal blood, and foetal development was unremarkable throughout the pregnancy. Delivery was induced at 39 weeks with a close monitoring of ammonemia levels and i.v. perfusion of carbohydrates and lipids during labour and immediately post-partum to avoid hypercatabolism. Delivery was uneventful and the patient delivered a healthy female baby. Urea cycle disorders should be contemplated in non-jaundiced patients with ALI or ALF, severe hyperammonemia and normal serum creatinine regardless of serum aminotransferase levels. The prompt recognition of this rare condition and the rapid initiation of adequate metabolic therapy are mandatory to prevent irreversible neurological sequelae and to avoid liver transplantation. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  17. Ruminal Nitrogen Recycling and Nitrogen Efficiency in Lactating Dairy Cattle

    OpenAIRE

    Aguilar, Michelle

    2012-01-01

    Excess nitrogen (N) excretion from animal agriculture results in reduced air and water quality, and poses a risk to human health. Although the dairy industry utilizes milk urea N (MUN) to monitor protein feeding and N excretion, phenotypic diversity among cows may influence MUN and thus bias feed management. An initial study using data from 2 previously published research trials and a field trial, observed that cow had a significant effect on MUN variation. Regression models, utilized ...

  18. Can salivary creatinine and urea levels be used to diagnose chronic kidney disease in children as accurately as serum creatinine and urea levels? A case-control study.

    Science.gov (United States)

    Renda, Rahime

    2017-11-01

    Children with chronic kidney disease (CKD) develop many metabolic changes in blood that often necessitate frequent biochemical analysis. Serum analysis is an invasive and painful procedure. It would be highly beneficial if a noninvasive alternative process to serum analysis in children were identified. Saliva can be collected noninvasively, repeatedly, and without the use of healthcare personnel. The aims of this study were to compare serum and salivary urea and creatinine levels in children with CKD and healthy controls, and to determine if salivary creatinine and urea levels can be used to diagnose CKD in children as accurately as serum creatinine and urea levels. This case-control study included 35 children with CKD and 28 healthy children as controls. Saliva and blood samples were collected for measurement of urea and creatinine levels. The urea and creatinine levels in serum and saliva in the CKD and control groups were compared using the independent samples Mann-Whitney U test. Correlations between the serum and salivary urea and creatinine levels were determined using Pearson's correlation coefficient. Receiver operating characteristic analysis was used to assess the diagnostic performance of salivary creatinine and cutoff values were identified. In the CKD group, the mean salivary creatinine level was 0.45 mg/dL and the mean salivary urea level was 0.11 mg/dL, versus 28.83 mg/dL and 21.78 mg/dL, respectively, in the control group. Stage 4 and 5 CKD patients had a mean salivary urea level of 31.35 mg/dL, as compared to 17.78 mg/dL in the control group. Serum urea and creatinine, and salivary creatinine were significantly higher in the CKD patients (regardless of disease stage) than in the controls (p creatinine. The area under the curve for salivary creatinine was 0.805. The cutoff value for salivary creatinine was 0.125 mg/dL, with a sensitivity of 82.9% and specificity of 78.6%. Based on the positive correlation between the serum and saliva

  19. Effects of Feeding Ammoniated Cottonseed Hull on Ruminal Environment Indexes and Serum Urea Nitrogen Content of Tarim Red Deer%饲喂氨化棉籽壳对塔里木马鹿瘤胃内环境指标及血清尿素氮含量的影响

    Institute of Scientific and Technical Information of China (English)

    贾存辉; 钱文熙; 吐尔逊阿依·赛买提; 敖维平; 古力米拉·艾尼; 苏皮·赛迪

    2017-01-01

    This experiment was conducted study the effects of feeding ammoniated cottonseed hull on ruminal environment indexes and serum urea nitrogen content of Tarim red deer, and hope to provide a theoretical basis for ammoniated feed rational use of Tarim red deer. A paired experimental design ( feeding ammoniated cotton⁃seed hull before and after feeding ammoniated cottonseed hull) was used, and three Tarim red deer fitted with permanent rumen fistula were chosen as experimental animals. The experiment divided into 2 periods, and each period had a 7⁃day pretrial period plus a 15⁃day trial period. The Tarim red deer in prophase were fed a diet with 1 kg un⁃ammoniated cottonseed hull, and those in anaphase were fed a diet using ammoniated cottonseed hull to replace un⁃ammoniated cottonseed hull. The results showed as follows:after feeding ammoniated cotton⁃seed hull, ruminal fluid pH, ammonia nitrogen concentration, microbial protein content and serum urea nitro⁃gen content of Tarim red deer were significantly or extremely significantly increased compared with feeding am⁃moniated cottonseed hull before ( P<0.05 or P<0.01) , while the concentrations of ruminal fluid acetate, buty⁃rate and total volatile fatty acids ( VFA) were significantly decreased compared with feeding ammoniated cot⁃tonseed hull before ( P<0.05 or P<0.01) . The feed cost of Tarim red deer before and after feeding ammoni⁃ated cottonseed hull were 5. 55 and 5. 04 RMB/( head · d ) , respectively, and the cost was reduced 0.51 RMB/( head·d) . Thus, Tarim red deer on ammoniated cottonseed shell has a strong ability to adapt, the application of ammoniated cottonseed shell in the diet of Tarim red deer can effectively save protein feed, improve the utilization efficiency of forage and increase economic efficiency.%本试验旨在研究饲喂氨化棉籽壳对塔里木马鹿瘤胃内环境指标及血清尿素氮含量的影响,以期为塔里木马鹿对氨化饲料的合理利

  20. The crystal structure of urea nitrate

    NARCIS (Netherlands)

    Harkema, Sybolt; Feil, D.

    1969-01-01

    The structure of urea nitrate has been solved, by the use of three-dimensional X-ray data. Data were collected using Cu Ke and Mo K0~ radiations. The structure consists of layers with urea and nitrate groups held together by hydrogen bonds. The positions of all hydrogen atoms were found. The final R

  1. Urea synthesis in patients with chronic pancreatitis

    DEFF Research Database (Denmark)

    Hamberg, Ole; Andersen, Vibeke; Sonne, J

    2001-01-01

    Up-regulation of urea synthesis by amino acids and dietary protein intake may be impaired in patients with chronic pancreatitis (CP) due to the reduced glucagon secretion. Conversely, urea synthesis may be increased as a result of the chronic inflammation. The aims of the study were to determine...

  2. Experimental studies on urea degradation in seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Rajendran, A.; Joseph, T.; Reddy, C.V.G.

    polluted waters, resulting in the accumulation of ammonia. The urea decomposing bacteria varied between 7 and 40% among the total heterotrophic bacteria in Velsao Bay, while these were from 15 to 22% near Mormugao. The rate for biological oxidation of urea...

  3. 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.

  4. Highly sensitive enzymatic determination of urea based on the pH-dependence of the fluorescence of graphene quantum dots

    International Nuclear Information System (INIS)

    Shao, Taili; Zhang, Ping; Zhuo, Shujuan; Zhu, Changqing; Tang, Lin

    2015-01-01

    We report on a nanoparticle-based fluorescent sensing scheme for urea. It is based on the finding that graphene quantum dots (GQDs) display pH-sensitive green fluorescence if photoexcited at 460 nm. Fluorescence is gradually quenched due to an increase in the local pH value as a result of the hydrolysis of urea as catalyzed by urease. The effect was used to quantify urea in the 0.1–100 mM concentration range, with a limit of detection of 0.01 mM. The method was successfully applied to the determination of urea in human serum samples. The method is simple, effective, and therefore holds promise as a platform for sensing urea in blood. (author)

  5. Application effects of coated urea and urease and nitrification inhibitors on ammonia and greenhouse gas emissions from a subtropical cotton field of the Mississippi delta region

    International Nuclear Information System (INIS)

    Tian, Zhou; Wang, Jim J.; Liu, Shuai; Zhang, Zengqiang; Dodla, Syam K.; Myers, Gerald

    2015-01-01

    Nitrogen (N) fertilization affects both ammonia (NH 3 ) and greenhouse gas (GHG) emissions that have implications in air quality and global warming potential. Different cropping systems practice varying N fertilizations. The aim of this study was to investigate the effects of applications of polymer-coated urea and urea treated with N process inhibitors: NBPT [N-(n-butyl)thiophosphoric triamide], urease inhibitor, and DCD [Dicyandiamide], nitrification inhibitor, on NH 3 and GHG emissions from a cotton production system in the Mississippi delta region. A two-year field experiment consisting of five treatments including the Check (unfertilized), urea, polymer-coated urea (ESN), urea + NBPT, and urea + DCD was conducted over 2013 and 2014 in a Cancienne loam (Fine-silty, mixed, superactive, nonacid, hyperthermic Fluvaquentic Epiaquepts). Ammonia and GHG samples were collected using active and passive chamber methods, respectively, and characterized. The results showed that the N loss to the atmosphere following urea-N application was dominated by a significantly higher emission of N 2 O-N than NH 3 -N and the most N 2 O-N and NH 3 -N emissions were during the first 30–50 days. Among different N treatments compared to regular urea, NBPT was the most effective in reducing NH 3 -N volatilization (by 58–63%), whereas DCD the most significant in mitigating N 2 O-N emissions (by 75%). Polymer-coated urea (ESN) and NBPT also significantly reduced N 2 O-N losses (both by 52%) over urea. The emission factors (EFs) for urea, ESN, urea-NBPT, urea + DCD were 1.9%, 1.0%, 0.2%, 0.8% for NH 3 -N, and 8.3%, 3.4%, 3.9%, 1.0% for N 2 O-N, respectively. There were no significant effects of different N treatments on CO 2 -C and CH 4 -C fluxes. Overall both of these N stabilizers and polymer-coated urea could be used as a mitigation strategy for reducing N 2 O emission while urease inhibitor NBPT for reducing NH 3 emission in the subtropical cotton production system of the

  6. The effect of concentration and exposure time on 15N uptake and incorporation from urea and ammonium nitrate by spring barley in the initial growth period

    International Nuclear Information System (INIS)

    Matula, J.; Knop, K.

    1978-01-01

    The uptake and incorporation of 15 N from urea and ammonium nitrate by spring barley were studied in aquaculture at three nitrogen concentrations in complex nutrient solutions (28, 140 and 700 mg N per 1 litre) and for three lengths of exposure to 15 N-labelled nutrient solutions. The 'Diamant' variety plants were precultivated up to the stage of the 3rd to 4th leaf in a complex nutrient solution, and five days prior to exposure to 15 N-labelled solutions the plants were cultivated in a nutrient solution without nitrogen. At a concentration of 28 mg N per litre the course of urea absorption was similar to the absorption of ammonium nitrate, but at a lower level. The results suggest that urea uptake is basically controlled by the metabolic requirement, particularly at lower concentrations. Only at the highest concentrations of nitrogen in the nutrient solutions did the 15 N of urea and ammonium nitrate penetrate into the roots, passive uptake being preferred. The uptake of urea is controlled by the metabolic requirement but its availability for barley metabolism is lower. Ammonium nitrate NO 3 - was taken up at a lower rate than NH 4 + from the same compound. Nitrate nitrogen was transported relatively more intensively to the above-ground parts of barley. The increasing concentration of nitrogen and exposure to nutrient solutions induced a rise in the proportion of ethanol-soluble forms of nitrogen, particularly in the roots. (author)

  7. Extrinsic nerves are not involved in branchial 5-HT dynamics or pulsatile urea excretion in Gulf toadfish, Opsanus beta.

    Science.gov (United States)

    Cartolano, Maria C; Amador, Molly H B; Tzaneva, Velislava; Milsom, William K; McDonald, M Danielle

    2017-12-01

    Gulf toadfish (Opsanus beta) can switch from continuously excreting ammonia as their primary nitrogenous waste to excreting predominantly urea in distinct pulses. Previous studies have shown that the neurotransmitter serotonin (5-HT) is involved in controlling this process, but it is unknown if 5-HT availability is under central nervous control or if the 5-HT signal originates from a peripheral source. Following up on a previous study, cranial nerves IX (glossopharyngeal) and X (vagus) were sectioned to further characterize their role in controlling pulsatile urea excretion and 5-HT release within the gill. In contrast to an earlier study, nerve sectioning did not result in a change in urea pulse frequency. Total urea excretion, average pulse size, total nitrogen excretion, and percent ureotely were reduced the first day post-surgery in nerve-sectioned fish but recovered by 72h post-surgery. Nerve sectioning also had no effect on toadfish urea transporter (tUT), 5-HT transporter (SERT), or 5-HT 2A receptor mRNA expression or 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) abundance in the gill, all of which were found consistently across the three gill arches except 5-HIAA, which was undetectable in the first gill arch. Our findings indicate that the central nervous system does not directly control pulsatile urea excretion or local changes in gill 5-HT and 5-HIAA abundance. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. 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...

  9. UREA BREATH TEST – ITS ROLE IN DIAGNOSTICS

    Directory of Open Access Journals (Sweden)

    Joško Osredkar

    2004-01-01

    Full Text Available Background. Each year many patients visit their physicians complaining of digestive symptoms, most commonly functional dyspepsia (»indigestion« or gastroesophageal reflux (»heartburn«. However, many patients with abdominal discomfort are actually suffering from gastric or duodenal ulcers that are commonly caused by H. pylori and thus are curable. Clearing the infection usually heals the ulcer and prevents relapse, so an accurate diagnosis is important. There are several options for diagnosing H. pylori infection: serology to detect antibodies against the bacterium; endoscopic biopsy for urease testing (H. pylori produce a urease that breaks down urea to ammonia and carbon dioxide; histology with special stains; or culture. Unfortunately, these procedures are invasive, expensive and not always accurate. Serological tests require a blood sample and tell only that a patient has been exposed to H. pylori at some time in the past, but not whether the patient is currently infected. Endoscopy and biopsy can detect current infection — the CLO test urease test allows rapid detection of H. pylori in gastric biopsy specimens — but endoscopy and biopsy are unpleasant medical procedures.Recently, noninvasive, sensitive, specific, easy to perform and patient’s well accepted methods had been developed known as urea breath test (UBT. When an infected person swallows a dose of urea labeled with an isotope of carbon — carbon-13 (13C or carbon-14 (14C – H. pylori in the gastric mucosa break down the labeled urea to form ammonia and labeled carbon dioxide. The carbon dioxide is absorbed into the bloodstream and excreted via the lungs. The patient then exhales into a device that measures the level of carbon dioxide. The urea breath test is specific for H. pylori (it detects only urease-producing bacteria, it is sensitive (the labeled urea reaches a large area of the stomach and thus reflects total gastric urease activity and the results can be

  10. Investigation of some urea derivatives under in vitro conditions

    International Nuclear Information System (INIS)

    Goersch, R.; Bergner, H.

    1978-01-01

    The protein synthesis from urea, isobutylidene diurea (IBDU), acetyl urea and urea phosphate was investigated in vitro under standardized conditions. The 35 S incorporation into the trichloroacetic acid precipitable fraction of the fermentation mixture and the NH 3 level served as test criteria. If rumen juice of donor animals adapted to urea was used (test 1), only IBDU made possible a protein synthesis comparable to the urea preparation. Under conditions of IBDU adaption of the donor animals (test 2), urea, IBDU and urea phosphate proved to be of equal value. Acetyl urea showed considerably lower incorporation ratios, irrespective of the adaption of the donor animals. (author)

  11. Investigation of some urea derivatives under in vitro conditions

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-10-01

    The protein synthesis from urea, isobutylidene diurea (IBDU), acetyl urea and urea phosphate was investigated in vitro under standardized conditions. The /sup 35/S incorporation into the trichloroacetic acid precipitable fraction of the fermentation mixture and the NH/sub 3/ level served as test criteria. If rumen juice of donor animals adapted to urea was used (test 1), only IBDU made possible a protein synthesis comparable to the urea preparation. Under conditions of IBDU adaption of the donor animals (test 2), urea, IBDU and urea phosphate proved to be of equal value. Acetyl urea showed considerably lower incorporation ratios, irrespective of the adaption of the donor animals.

  12. Validation of the salivary urea and creatinine tests as screening methods of chronic kidney disease in Vietnamese patients.

    Science.gov (United States)

    Pham, Thuy Anh Vu

    2017-11-01

    The aims of this case control study were to correlate the serum and salivary urea as well as creatinine levels; and to evaluate salivary urea and creatinine as noninvasive alternatives to serum for creatinine estimation in chronic kidney disease (CKD) patients. Blood and saliva samples were collected from 112 CKD patients and 108 subjects without CKD for quantitative analysis of urea and creatinine. Spearman's correlation coefficients between salivary and serum urea as well as creatinine were obtained. Receiver operating characteristic analysis was done to assess the diagnostic tests of salivary urea and creatinine. Cut-off values were determined based on the best trade-off between the sensitivity and specificity for both salivary urea and creatinine. Salivary urea and creatinine concentrations were significantly higher in CKD patients than those in control subjects; and increased by the stages of the severity of the disease. The positive correlation was significantly found between salivary and serum creatinine (r  =  0.90) and between salivary and serum urea (r  =  0.73). Area under the curve for salivary urea was 0.76 and a cut-off value of 14.25 mmol/L gave a sensitivity of 82.9% and specificity of 57.8%. Area under the curve for salivary creatinine was 0.92 and a cut-off value of 0.24 mg/dL gave a sensitivity of 86.5% and specificity of 87.2%. Both salivary urea and creatinine have a high capacity for serum creatinine estimation. Salivary urea and creatinine tests can be used as low-cost, easily accessible and noninvasive tools for screening, diagnosing, monitoring treatment outcomes and ascertaining prognosis of chronic kidney disease.

  13. Improving formulated nitrogen, phosphorus and potassium ...

    African Journals Online (AJOL)

    User

    2012-08-14

    Aug 14, 2012 ... because zeolite favoured formation of ammonium and nitrate over ammonia. ... compound fertilizer with zeolite to improve nitrogen efficiency by lowering ammonia volatilization and .... The phosphoric acid produced by hydrolysis of ... nitrification inhibitors added to urea on nitrous oxide emissions from a.

  14. The evolution of blood pressure and the rise of mankind.

    Science.gov (United States)

    Schulte, Kevin; Kunter, Uta; Moeller, Marcus J

    2015-05-01

    Why is it that only human beings continuously perform acts of heroism? Looking back at our evolutionary history can offer us some potentially useful insight. This review highlights some of the major steps in our evolution-more specifically, the evolution of high blood pressure. When we were fish, the first kidney was developed to create a standardized internal 'milieu' preserving the primordial sea within us. When we conquered land as amphibians, the evolution of the lung required a low systemic blood pressure, which explains why early land vertebrates (amphibians, reptiles) are such low performers. Gaining independence from water required the evolution of an impermeable skin and a water-retaining kidney. The latter was accomplished twice with two different solutions in the two major branches of vertebrate evolution: mammals excrete nitrogenous waste products as urea, which can be utilized by the kidney as an osmotic agent to produce more concentrated urine. Dinosaurs and birds have a distinct nitrogen metabolism and excrete nitrogen as water-insoluble uric acid-therefore, their kidneys cannot use urea to concentrate as well. Instead, some birds have developed the capability to reabsorb water from their cloacae. The convergent development of a separate small circulation of the lung in mammals and birds allowed for the evolution of 'high blood-pressure animals' with better capillarization of the peripheral tissues allowing high endurance performance. Finally, we investigate why mankind outperforms any other mammal on earth and why, to this day, we continue to perform acts of heroism on our eternal quest for personal bliss. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  15. Protein- and diabetes-induced glomerular hyperfiltration: role of glucagon, vasopressin, and urea.

    Science.gov (United States)

    Bankir, Lise; Roussel, Ronan; Bouby, Nadine

    2015-07-01

    A single protein-rich meal (or an infusion of amino acids) is known to increase the glomerular filtration rate (GFR) for a few hours, a phenomenon known as "hyperfiltration." It is important to understand the factors that initiate this upregulation because it becomes maladaptive in the long term. Several mediators and paracrine factors have been shown to participate in this upregulation, but they are not directly triggered by protein intake. Here, we explain how a rise in glucagon and in vasopressin secretion, directly induced by protein ingestion, might be the initial factors triggering the hepatic and renal events leading to an increase in the GFR. Their effects include metabolic actions in the liver and stimulation of sodium chloride reabsorption in the thick ascending limb. Glucagon is not only a glucoregulatory hormone. It is also important for the excretion of nitrogen end products by stimulating both urea synthesis in the liver (along with gluconeogenesis from amino acids) and urea excretion by the kidney. Vasopressin allows the concentration of nitrogenous end products (urea, ammonia, etc.) and other protein-associated wastes in a hyperosmotic urine, thus allowing a very significant water economy characteristic of all terrestrial mammals. No hyperfiltration occurs in the absence of one or the other hormone. Experimental results suggest that the combined actions of these two hormones, along with the complex intrarenal handling of urea, lead to alter the composition of the tubular fluid at the macula densa and to reduce the intensity of the signal activating the tubuloglomerular feedback control of GFR, thus allowing GFR to raise. Altogether, glucagon, vasopressin, and urea contribute to set up the best compromise between efficient urea excretion and water economy. Copyright © 2015 the American Physiological Society.

  16. The effects of a hind-gut fermentation on urea kinetics in sheep

    International Nuclear Information System (INIS)

    Oncuer, A.

    1988-01-01

    Four female sheep were fitted with rumen cannulas and abomasal and ileal infusion catheters; one of the sheep was also fitted with a cannula at the caecum. All animals were nourished wholly by intragastric infusion of nutrients to the rumen and abomasum and received in addition three levels of nutrient infusion into the terminal ileum in order to achieve different levels of hind-gut fermentation. The ileal infusion treatments were (1) water infusion; (2) 25 g/d starch and 50 g/d cellulose infusion; (3) 50 g/d starch and 50 g/d cellulose infusion. In each 2 week period, the first 7 days served as the preliminary period infusion. Days 8-12 inclusive were used for quantitative collection of faeces and urine for digestibility and nitrogen balance measurement and on day 14 an injection of ( 14 C)-urea was given into a jugular vein for measurement of urea kinetics. Hind-gut fermentation did not significantly affect any parameters of urea metabolism. Although degradation of urea did not differ significantly between treatments an increase of over 2 g/d was observed in progressing from the lowest to the highest level of hind-gut infusion. Faecal nitrogen excretion increased significantly from 21.8 to 74.7 mg N/kg 0.75 /d (P 0.01) and urinary urea-N decreased significantly from 278.9 to 252.3 mg/kg 0.75 /d (P 0.05) in the presence of a hind-gut fermentation. Close relationships were observed between various parameters of urea metabolism

  17. Transitioning from phosphate mining to agriculture: Responses to urea and slow release fertilizers for Sorghum bicolor.

    Science.gov (United States)

    Ruthrof, Katinka X; Steel, Emma; Misra, Sunil; McComb, Jen; O'Hara, Graham; Hardy, Giles E St J; Howieson, John

    2018-06-01

    Globally, land-use transition from mining to agriculture is becoming increasingly attractive and necessary for many reasons. However, low levels of necessary plant nutrients, and high levels of heavy metals, can hamper plant growth, affecting yield, and potentially, food safety. In post-phosphate mining substrates, for example, nitrogen (N) is a key limiting nutrient, and, although legumes are planted prior to cereals, N supplementation is still necessary. We undertook two field trials on Christmas Island, Australia, to determine whether Sorghum bicolor could be grown successfully in a post-phosphate mining substrate. The first trial investigated N (urea) demand (amount of N required for adequate crop growth) for S. bicolor, and whether N addition could reduce the naturally occurring cadmium (Cd) concentrations in the crop. The second trial examined whether slow release nitrogen fertilizers (SRF) could replace urea to increase biomass and reduce Cd concentrations. Our first trial demonstrated that S. bicolor has a high N demand, with the highest biomass being recorded in the 160kg/ha urea treatment. However, plants treated with 80, 120 and 160kg/ha were not significantly different from one another. After 7weeks of growth, leaf Cd concentrations were significantly lower for all urea treatments compared with the control plants. However, after 23weeks, seed Cd concentrations did not differ across treatments. Our second trial demonstrated that the application of SRF (Macracote® and Sulsync®) and 160kg/ha urea significantly increased biomass above the control plants. There was, however, no treatment response in terms of Cd or N concentrations in the seed at final harvest. Thus, we have shown that N is currently critical for S. bicolor, even following legume cropping, and that high biomass and a significant reduction in Cd can be attained with appropriate levels of urea. Our work has important implications for cereal growth and food safety in post-mining agriculture

  18. Mixed Cropping of Legumes and Maize by the Use of Urea

    Directory of Open Access Journals (Sweden)

    Esmaeil Alibakhshi

    2016-10-01

    Full Text Available To study the effect of nitrogenous fertilizers and mixed cropping of legumes and maize on its grain yield and yield component of corn in Arak, an experiment was carried at the Agricultural Research Center of Markazi Province in 2013. A factorial experiment based on randomized complete block design with three replications was performed. Treatments were four levels of urea (N0= control, N1= 75 kg.ha-1, N2= 150 kg.ha-1, N3= 225 kg.ha-1 and mixed cropping with four levels (S1= planting corn, S2= planting corn + chickpea, S3= planting corn + cowpea, S4= planting corn + mung bean. Plot consisted of 4 rows, 6 m long with 60 cm between rows space and 20 cm between plants on the rows, and S.C 704 corn hybrid was used. In this study characteristics such as: plant height, number of green leaf, grain yield, number of row per ear, number of grain per ear row, nitrogen use efficiency, biomasses of legumes, nitrogen percentage and 1000 grain weight were assessed. Results indicated that the effect of different levels of urea on plant height, number of green leaf, grain yield, number of grain per row, nitrogen use efficiency, legumes biomass and nitrogen percentage were significant. Effect of mixed cropping on characteristics like grain yield, nitrogen use efficiency, biomasses of legumes nitrogen percentage was also significant. Highest and lowest grain yield (7.37 and 5.47 t.ha-1 were obtained with the use of 225 and 75 kg.ha-1 urea, respectively. The highest and lowest grain yield (7.30 and 6.01 t.ha-1 belonged to sole cropping at corn and mixed cropping of corn + mung bean, respectively.

  19. Effect of an ntrC mutation on amino acid or urea utilization and on nitrogenase switch-off in Herbaspirillum seropedicae.

    Science.gov (United States)

    Gusso, Claudio L; de Souza, Emanuel M; Rigo, Liu Un; de Oliveira Pedrosa, Fábio; Yates, M G; de M Rego, Fabiane G; Klassen, Giseli

    2008-03-01

    Herbaspirillum seropedicae is a nitrogen-fixing bacterium that grows well with ammonium chloride or sodium nitrate as alternative single nitrogen sources but that grows more slowly with L-alanine, L-serine, L-proline, or urea. The ntrC mutant strain DCP286A was able to utilize only ammonium or urea of these nitrogen sources. The addition of 1 mmol.L-1 ammonium chloride to the nitrogen-fixing wild-type strain inhibited nitrogenase activity rapidly and completely. Urea was a less effective inhibitor; approximately 20% of nitrogenase activity remained 40 min after the addition of 1 mmol x L-1 urea. The effect of the ntrC mutation on nitrogenase inhibition (switch-off) was studied in strain DCP286A containing the constitutively expressed gene nifA of H. seropedicae. In this strain, nitrogenase inhibition by ammonium was completely abolished, but the addition of urea produced a reduction in nitrogenase activity similar to that of the wild-type strain. The results suggest that the NtrC protein is required for assimilation of nitrate and the tested amino acids by H. seropedicae. Furthermore, NtrC is also necessary for ammonium-induced switch-off of nitrogenase but is not involved in the mechanism of nitrogenase switch-off by urea.

  20. Fertilization with urea, ammonium and nitrate produce different effects on growth, hydraulic traits and drought tolerance in Pinus taeda seedlings.

    Science.gov (United States)

    Faustino, Laura I; Moretti, Ana P; Graciano, Corina

    2015-10-01

    Urea fertilization decreases Pinus taeda L. growth in clay soils of subtropical areas. The negative effect of urea is related to changes in some hydraulic traits, similar to those observed in plants growing under drought. The aims of this work were (i) to determine whether different sources of nitrogen applied as fertilizers produce similar changes in growth and hydraulic traits to those observed by urea fertilization and (ii) to analyze the impact of those changes in plant drought tolerance. Plants fertilized with urea, nitrate [Formula: see text] or ammonium [Formula: see text] were grown well watered or with reduced water supply. Urea and [Formula: see text] fertilization reduced plant growth and increased root hydraulic conductance scaled by root dry weight (DW). [Formula: see text] fertilization did not reduce plant growth and increased shoot hydraulic conductance and stem hydraulic conductivity. We conclude that [Formula: see text] is the ion involved in the changes linked to the negative effect of urea fertilization on P. taeda growth. [Formula: see text] fertilization does not change drought susceptibility and it produces changes in shoot hydraulic traits, therefore plants avoid the depressive effect of fertilization. Urea and [Formula: see text] fertilizers induce changes in DW and root hydraulic conductance and consequently plants are less affected by drought. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Influence of exogenous urea on photosynthetic pigments, (14)CO 2 uptake, and urease activity in Elodea densa-environmental implications.

    Science.gov (United States)

    Maleva, Maria; Borisova, Galina; Chukina, Nadezda; Nekrasova, Galina; Prasad, M N V

    2013-09-01

    This paper analyzes the effect of exogenous urea in increased concentration gradient (0, 100, 500 and 1,000 mg L(-1)) on photosynthetic pigments (measured spectrophotometrically), uptake of (14)CO2 (using radioisotope), and urease activity (by measuring ammonia with Nessler's reagent) in leaves of Elodea densa Planch. We have observed that low concentration of urea (100 mg L(-1)) stimulates the accumulation of photosynthetic pigments and intensifies photosynthesis in E. densa, whereas high concentration (1,000 mg L(-1)) suppresses these processes. Urease activity increased by approximately 2.7 and 8 fold when exogenous urea concentrations were 100 and 500 mg L(-1), respectively. However, exogenous urea in high concentration (1,000 mg L(-1)) decreased urease activity by 1.5 fold compared to the control. The necessity of mitigating urea and other nitrogen-containing compounds (NH3 from urea) in water bodies has been discussed with emphasis on the potential for phytoremediation of urea using common water weed viz. E. densa.

  2. Nitrogen metabolism, acid-base regulation, and molecular responses to ammonia and acid infusions in the spiny dogfish shark (Squalus acanthias).

    Science.gov (United States)

    Nawata, C Michele; Walsh, Patrick J; Wood, Chris M

    2015-07-01

    Although they are ureotelic, marine elasmobranchs express Rh glycoproteins, putative ammonia channels. To address questions raised by a recent study on high environmental ammonia (HEA) exposure, dogfish were intravascularly infused for 24 h at 3 ml kg(-1) h(-1) with isosmotic NaCl (500 mmol l(-1), control), NH4HCO3 (500 mmol l(-1)), NH4Cl (500 mmol l(-1)), or HCl (as 125 mmol l(-1) HCl + 375 mmol l(-1) NaCl). While NaCl had no effect on arterial acid-base status, NH4HCO3 caused mild alkalosis, NH4Cl caused strong acidosis, and HCl caused lesser acidosis, all predominantly metabolic in nature. Total plasma ammonia (T(Amm)) and excretion rates of ammonia (J(Amm)) and urea-N (J(Urea-N)) were unaffected by NaCl or HCl. However, despite equal loading rates, plasma T(Amm) increased to a greater extent with NH4Cl, while J(Amm) increased to a greater extent with NH4HCO3 due to much greater increases in blood-to-water PNH3 gradients. As with HEA, both treatments caused large (90%) elevations of J(Urea-N), indicating that urea-N synthesis by the ornithine-urea cycle (OUC) is driven primarily by ammonia rather than HCO3(-). Branchial mRNA expressions of Rhbg and Rhp2 were unaffected by NH4HCO3 or NH4Cl, but v-type H(+)-ATPase was down-regulated by both treatments, and Rhbg and Na(+)/H(+) exchanger NHE2 were up-regulated by HCl. In the kidney, Rhbg was unresponsive to all treatments, but Rhp2 was up-regulated by HCl, and the urea transporter UT was up-regulated by HCl and NH4Cl. These responses are discussed in the context of current ideas about branchial, renal, and OUC function in this nitrogen-limited predator.

  3. Fatal ammonia toxicity in an adult due to an undiagnosed urea cycle defect: under-recognition of ornithine transcarbamylase deficiency.

    Science.gov (United States)

    Thurlow, Vanessa R; Asafu-Adjaye, Michelle; Agalou, Stamatina; Rahman, Yusof

    2010-05-01

    There is a lack of awareness of acutely presenting inborn errors of metabolism in adults, of which the X-linked urea cycle defect ornithine transcarbamylase (OTC) deficiency is an example, many comparatively mild mutations having been identified. In male hemizygotes clinical manifestations and age at presentation vary and depend on the mutation. In female heterozygotes the clinical spectrum depends on the extent to which the abnormal gene is expressed. Milder versions of the defect may not cause clear clinical symptoms and may remain unrecognized until the person is subjected to an unusually high nitrogen load when they develop severe hyperammonaemia. During acute episodes liver enzymes may be normal or only slightly elevated and occasionally accompanied by coagulopathy, but the key finding is hyperammonaemia. Boys with these milder forms may exhibit abnormal behaviour and be diagnosed with attention deficit hyperactivity disorder. This case illustrates how late presentation of OTC deficiency in a non-specialist centre can be difficult to differentiate from drug abuse, psychiatric illness or encephalopathy. Failure to measure blood ammonia in adults with unexplained key symptoms - particularly prolonged vomiting without diarrhoea and altered mental state/hallucinations, or to recognize the significance of elevated blood ammonia without evidence of liver decompensation can lead to delayed or missed diagnosis.

  4. 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).

  5. Pseudomonas aeruginosa mutants resistant to urea inhibition of growth on acetanilide.

    Science.gov (United States)

    Gregoriou, M; Brown, P R; Tata, R

    1977-11-01

    Pseudomonas aeruginosa AI 3 was able to grow in medium containing acetanilide (N-phenylacetamide) as a carbon source when NH4+ was the nitrogen source but not when urea was the nitrogen source. AIU mutants isolated from strain AI 3 grew on either medium. Urease levels in bacteria grown in the presence of urea were 10-fold lower when NH4+ or acetanilide was also in the medium, but there were no apparent differences in urease or its synthesis between strain AI 3 and mutant AIU 1N. The first metabolic step in the acetanilide utlization is catalyzed by an amidase. Amidases in several AIU strains showed altered physiochemical properties. Urea inhibited amidase in a time-dependent reaction, but the rates of the inhibitory reaction with amidases from the AIU mutants were slower than with AI 3 amidase. The purified amidase from AIU 1N showed a marked difference in its pH/activity profile from that obtained with purified AI 3 amidase. These observations indicate that the ability of strain AIU 1N and the other mutants to grow on acetanilide/urea medium is associated with a mutation in the amidase structural gene; this was confirmed for strain AIU 1N by transduction.

  6. 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)

  7. Recovery of 15N-urea in soil-plant system of tanzania grass pasture

    International Nuclear Information System (INIS)

    Martha Junior, Geraldo Bueno; Vilela, Lourival; Corsi, Moacyr; Trivelin, Paulo Cesar Ocheuze

    2009-01-01

    The economic attractiveness and negative environmental impact of nitrogen (N) fertilization in pastures depend on the N use efficiency in the soil-plant system. However, the recovery of urea- 15 N by Panicum maximum cv. Tanzania pastures, one of the most widely used forage species in intensified pastoral systems, is still unknown. This experiment was conducted in a randomized complete block design with four treatments (0, 40, 80 and 120 kg ha-1 of N-urea) and three replications, to determine the recovery of 15 N urea by Tanzania grass. Forage production, total N content and N yield were not affected by fertilization (p > 0.05), reflecting the high losses of applied N under the experimental conditions. The recovery of 15 N urea (% of applied N) in forage and roots was not affected by fertilization levels (p > 0.05), but decreased exponentially in the soil and soil-plant system (p 15 N (kg ha -1 ) in forage and roots (15 to 30 cm) increased with increasing urea doses (p < 0.05). (author)

  8. Identification of elevated urea as a severe, ubiquitous metabolic defect in the brain of patients with Huntington's disease.

    Science.gov (United States)

    Patassini, Stefano; Begley, Paul; Reid, Suzanne J; Xu, Jingshu; Church, Stephanie J; Curtis, Maurice; Dragunow, Mike; Waldvogel, Henry J; Unwin, Richard D; Snell, Russell G; Faull, Richard L M; Cooper, Garth J S

    Huntington's disease (HD) is a neurodegenerative disorder wherein the aetiological defect is a mutation in the Huntington's gene (HTT), which alters the structure of the huntingtin protein through the lengthening of a polyglutamine tract and initiates a cascade that ultimately leads to dementia and premature death. However, neurodegeneration typically manifests in HD only in middle age, and processes linking the causative mutation to brain disease are poorly understood. Here, our objective was to elucidate further the processes that cause neurodegeneration in HD, by measuring levels of metabolites in brain regions known to undergo varying degrees of damage. We applied gas-chromatography/mass spectrometry-based metabolomics in a case-control study of eleven brain regions in short post-mortem-delay human tissue from nine well-characterized HD patients and nine controls. Unexpectedly, a single major abnormality was evident in all eleven brain regions studied across the forebrain, midbrain and hindbrain, namely marked elevation of urea, a metabolite formed in the urea cycle by arginase-mediated cleavage of arginine. Urea cycle activity localizes primarily in the liver, where it functions to incorporate protein-derived amine-nitrogen into urea for recycling or urinary excretion. It also occurs in other cell-types, but systemic over-production of urea is not known in HD. These findings are consistent with impaired local urea regulation in brain, by up-regulation of synthesis and/or defective clearance. We hypothesize that defective brain urea metabolism could play a substantive role in the pathogenesis of neurodegeneration, perhaps via defects in osmoregulation or nitrogen metabolism. Brain urea metabolism is therefore a target for generating novel monitoring/imaging strategies and/or therapeutic interventions aimed at ameliorating the impact of HD in patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Zeolite Soil Application Method Affects Inorganic Nitrogen, Moisture, and Corn Growth

    Science.gov (United States)

    Adoption of new management techniques which improve soil water storage and soil nitrogen plant availability yet limit nitrogen leaching may help improve environmental quality. A benchtop study was conducted to determine the influence of a single urea fertilizer rate (224 kilograms of Nitrogen per ...

  10. Blood Chemistry Reference Values for Free-Ranging Asiatic Black Bears ( Ursus thibetanus) by Season, Age, and Sex.

    Science.gov (United States)

    Yang, Jeong-Jin; Jeong, Dong-Hyuk; Lim, Yoon-Kyu

    2018-04-19

    Physiological characteristics, such as blood chemistry values, are valuable for evaluating the health of the animals. To our knowledge, these values have never been reported for the free-ranging Asiatic black bear ( Ursus thibetanus; ABB). Thus, 28 blood chemistry values from 50 free-ranging ABBs captured in Jirisan National Park, Republic of Korea, from 2005 to 2016 were evaluated. The aim of this study was to establish blood chemistry reference values for the free-ranging ABBs during both the hibernating and nonhibernating seasons. During hibernation, mean values of creatinine (CRE), total cholesterol, total protein (TP), albumin (ALB), triglycerides, and Mg were significantly higher than those during nonhibernation; however, mean values of blood urea nitrogen, urea nitrogen to creatinine (U/C) ratio, inorganic phosphorous (IP), aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, lactate dehydrogenase (LDH), high-density lipoprotein cholesterol, and alkaline phosphatase (ALP) were significantly lower. Age differences (young vs. adult) were found in IP, LDH, TP, and ALB values during hibernation and in the U/C ratio, Ca, IP, ALP, creatine kinase myocardial band, CRE, total bilirubin, and uric acid values during nonhibernation. However, there were no sex differences (male vs. female).

  11. RENAL FUNCTION TEST ON THE BASIS OF SERUM CREATININE AND UREA IN TYPE-2 DIABETICS AND NONDIABETICS

    Directory of Open Access Journals (Sweden)

    P. Singh

    2014-01-01

    Full Text Available Background: Type-2 diabetes mellitus has quickly become a global health problem due to rapidly increasing population growth, aging, urbanization and increasing prevalence of obesity and physical inactivity. Diabetic nephropathy is one of the major causes of chronic renal failure. Both serum urea and creatinine are widely used to assess the function of kidney. This study was conducted to observe the impaired renal function in type 2 diabetics and compare with non-diabetics controls. Method: To determine the incidence of renal dysfunction in diabetics in Nepalgunj medical college and Hospital , Nepalgunj , Banke, Nepal , blood samples from 100 diabetic subjects and 100 non-diabetic controls were taken between the period 1st February  , 2012  to  31st January , 2013 for investigation of  plasma glucose fasting(FPG, blood urea and serum creatinine. These biochemical parameters were determined by using a fully automated clinical chemistry analyzer. Results: Our findings showed that the level of blood urea (P<0.0001, 95%Cl and serum creatinine (P≈0.0004,95%Cl were significantly higher in type 2 diabetics as compared to non-diabetics in both male and female. There was no significant difference between diabetic male and female. 15 out of 100 diabetes samples have high urea level whereas 7 out of 100 had increased creatinine level. In control only 3 samples had high urea value and 1 had high creatinine level. There was statistical significant increased in urea level with increased in blood sugar level. Conclusion: Blood urea and creatinine is widely accepted to assess the renal functions. Good control of blood glucose level is absolute requirement to prevent progressive renal impairment.

  12. Green urea synthesis catalyzed by hematite nanowires in magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Yahya, Noorhana, E-mail: noorhana_yahya@petronas.com.my; Qureshi, Saima; Rehman, Zia ur; Alqasem, Bilal; Fai Kait, Chong

    2017-04-15

    The catalytic activity of hematite (α-Fe{sub 2}O{sub 3}) nanowires under the influence of magnetic field on urea synthesis is considered green. The adsorption and subsequent dissociative reaction of hydrogen, nitrogen and carbon dioxide gases on the α-Fe{sub 2}O{sub 3} (111) nanowires were investigated using the density functional theory (DFT) method. The average adsorption energy is −4.12 kcal/mole at different sites. The adsorption of gases resulted in a difference in density and net spin of electrons from 68 to 120 and 0–21 respectively. In addition, it induces magnetic moment value of 36.33 µB, which confirms the enhanced magnetic behaviour of hematite. α-Fe{sub 2}O{sub 3} nanowires (NWs) synthesized by heating iron wire in a box furnace at (750−800) °C and as synthesized α-Fe{sub 2}O{sub 3} nanoparticles (NPs) were received to use as a catalyst in the magnetic reaction of urea synthesis. X-ray Diffractometer (XRD) confirms the peaks of rhombohedral structure of α-Fe{sub 2}O{sub 3} and Raman spectrum analyses confirms the α-Fe{sub 2}O{sub 3} peaks at 410 cm{sup −1}, 500 cm{sup −1} and 616 cm{sup −1}. The needle-like shape of hematite nanowires with length ranging from 16–25) μm and diameter from 74 to 145 nm confirmed by Field emission scanning electron microscopy (FESEM). The magnetic properties of the nanowires exhibited different levels of saturation magnetization, for α-Fe{sub 2}O{sub 3} perpendicularly aligned direction (13.18 emu/g) and random direction (10.73 emu/g). Urea synthesis was done under magnetic field ranges from 0.0 to 2.5 T. The activation energy of α-Fe{sub 2}O{sub 3} NWs for urea production is lower than NPs in the range of 0–1 T, whereas it is reversed for higher magnetic induction values. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of urea at the peaks of 1690–1600 cm{sup −1}. This green urea employing magnetically induced method could be a contender to the Haber-Bosch process

  13. Modeling of flux, binding and substitution of urea molecules in the urea transporter dvUT.

    Science.gov (United States)

    Zhang, Hai-Tian; Wang, Zhe; Yu, Tao; Sang, Jian-Ping; Zou, Xian-Wu; Zou, Xiaoqin

    2017-09-01

    Urea transporters (UTs) are transmembrane proteins that transport urea molecules across cell membranes and play a crucial role in urea excretion and water balance. Modeling the functional characteristics of UTs helps us understand how their structures accomplish the functions at the atomic level, and facilitates future therapeutic design targeting the UTs. This study was based on the crystal structure of Desulfovibrio vulgaris urea transporter (dvUT). To model the binding behavior of urea molecules in dvUT, we constructed a cooperative binding model. To model the substitution of urea by the urea analogue N,N'-dimethylurea (DMU) in dvUT, we calculated the occupation probability of DMU along the urea pore and the ratio of the occupation probabilities of DMU at the external (S ext ) and internal (S int ) binding sites, and we established the mutual substitution rule for binding and substitution of urea and DMU. Based on these calculations and modelings, together with the use of the Monte Carlo (MC) method, we further modeled the urea flux in dvUT, equilibrium urea binding to dvUT, and the substitution of urea by DMU in the dvUT. Our modeling results are in good agreement with the existing experimental functional data. Furthermore, the modelings have discovered the microscopic process and mechanisms of those functional characteristics. The methods and the results would help our future understanding of the underlying mechanisms of the diseases associated with impaired UT functions and rational drug design for the treatment of these diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Urea and deuterium mixtures at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, M., E-mail: m.donnelly-2@sms.ed.ac.uk; Husband, R. J.; Frantzana, A. D.; Loveday, J. S. [Centre for Science at Extreme Conditions and School of Physics and Astronomy, The University of Edinburgh, Erskine Williamson Building, Peter Guthrie Tait Road, The King’s Buildings, Edinburgh EH9 3FD (United Kingdom); Bull, C. L. [ISIS, Rutherford Appleton Laboratory, Oxford Harwell, Didcot OX11 0QX (United Kingdom); Klotz, S. [IMPMC, CNRS UMR 7590, Université P and M Curie, 4 Place Jussieu, 75252 Paris (France)

    2015-03-28

    Urea, like many network forming compounds, has long been known to form inclusion (guest-host) compounds. Unlike other network formers like water, urea is not known to form such inclusion compounds with simple molecules like hydrogen. Such compounds if they existed would be of interest both for the fundamental insight they provide into molecular bonding and as potential gas storage systems. Urea has been proposed as a potential hydrogen storage material [T. A. Strobel et al., Chem. Phys. Lett. 478, 97 (2009)]. Here, we report the results of high-pressure neutron diffraction studies of urea and D{sub 2} mixtures that indicate no inclusion compound forms up to 3.7 GPa.

  15. Study of furfural-urea grout

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    An analysis of raw materials, formulation and performance of furfural-urea grout is given. Characteristics of the grout slurry, mechanism of stabilization and examples of shaft sinking with grouting in quicksand are summarized.

  16. Dry season supplementation of dairy cows with urea molasses mineral blocks and molasses-urea mix in the Morogoro region in Tanzania

    International Nuclear Information System (INIS)

    Plaizier, J.C.B.; McBride, B.W.; Nkya, R.; Shem, M.N.; Urio, N.A.

    1999-01-01

    The effects of supplementation with urea molasses mineral blocks and molasses-urea mix during and immediately prior to the dry season on the production of dairy cows were studied on-station and on small holder peri-urban farms near Morogoro, Tanzania. Supplementation of on-station cows receiving ad libitum grass hay and 6 kg/d of maize bran with urea molasses mineral blocks (UMMB), increased milk production from 6.7 L/d to 11.2 L/d (P <0.05) and dry matter intake from 10.1 kg/d to 12.0 kg/d (P <0.05), but did not significantly affect milk composition, intake of hay and live weight change. This increase in milk yield is mainly explained by increased intakes of energy and nitrogen. Supplementation with the molasses urea mix increased daily milk yield from 6.7 L/d to 8.8 L/d (P <0.05), but did not significantly affect the other measured production parameters. The on-farm supplementation with blocks increased daily milk yield by 1.7 L/d in the dry season (P <0.01). This supplementation did not increase milk yields prior to the dry season, since quality forage was still available. Taking the production costs into account, supplementation with the blocks and supplementation with molasses mix was cost effective if milk yields increased by 0.7 L/d. (author)

  17. Uptake of 15N-labelled urea and 32P-labelled phosphate from acid-based urea phosphate and granular fertilizers

    International Nuclear Information System (INIS)

    Bole, J.B.

    1986-01-01

    The availability of nitrogen and phosphorus in fertilizer products labelled with both 32 P and 15 N was measured in a growth chamber experiment. The uptake of N and P by soft white spring wheat (Triticum aestivum L.) from a solution of acid urea phosphate fertilizer did not differ significantly from that of a mixture of granular urea and monammonium phosphate fertilizer. The fertilizer-P uptake efficiency of both sources was higher in a neutral soil than in acid or calcareous soils. Banding either fertilizer increased the uptake of fertilizer P compared with sources mixed with the soil, but did not significantly affect fertilizer-N uptake. The increase in fertilizer-P efficiency due to banding was significantly greater for the urea-monammonium phosphate than for the acid urea phosphate solution. Banding fertilizer did not increase the uptake of fertilizer P in the calcareous soil, and decreased the uptake of fertilizer N in that soil compared with mixed treatments. It is suggested that soluble Ca formed from the reaction of acid with naturally occurring lime may have reduced the availability of fertilizer P in the band

  18. Effect of urea level and treating time on ruminal degradability of urea-treated rice straw evaluated by in sacco method

    Directory of Open Access Journals (Sweden)

    Promma, S.

    2006-07-01

    Full Text Available An experiment was conducted to evaluate the dry matter disappearance and potential degradability of urea-treated rice straw (UTS. Five kg of non-glutinous rice straw (RS was chopped and treated with urea solution and kept in a double sheet polyethylene bag. The ratio of RS to water was 1:1. The urea concentration was 4, 5 and 6% by weight of RS and the duration of treatment was 7, 14 and 21 days. There were 9 treatment combinations with 3 replications. The dry and ground UTS were weighted into nylon bags and incubated in 3 fistulated cows. The dry matter disappearance was detected at different incubation times. The result showed that CP content of UTS was higher than RS and the amount increased with the increasing level of urea. The longer treatment duration caused depletion in CP content. Nitrogen was lost as ammonia when UTS was dried, which led to the lower CP than fresh UTS. The duration of treating of 7, 14 and 21 days caused no-significant difference in potential degradability (71.61±2.59, 72.38±2.80 and 72.70±2.44%, respectively, P> 0.05, but 6% UTS has higher potential degradability than 4 % UTS (74.24± 0.53 and 69.84±1.03%, respectively, P< 0.05

  19. Modifications of Graphite and Multiwall Carbon Nanotubes in the Presence of Urea

    Science.gov (United States)

    Duraia, El-Shazly M.; Fahami, Abbas; Beall, Gary W.

    2018-02-01

    The effect of high-energy ball milling on two carbon allotropes, graphite and multiwall carbon nanotubes (MWCNT) in the presence of urea has been studied. Samples were investigated using Raman spectroscopy, x-ray diffraction, scanning electron microscope (SEM) and x-ray photoelectron spectroscopy (XPS). Nitrogen-doped graphene has been successfully synthesized via a simple scalable mechanochemistry method using urea and graphite powder precursors. XPS results revealed the existence of the different nitrogen atoms configurations including pyridine, pyrrodic and graphitic N. SEM observations showed that the graphene nanosheets morphology become more wrinkles folded and crumbled as the milling time increased. The ID/IG ratio also increased as the milling time rose. The presence of both D' and G + D bands at 1621 cm-1 and 2940 cm-1, respectively, demonstrated the nitrogen incorporation in the graphene lattice Two factors contribute to the used urea: first it helps to exfoliate graphite into graphene, and second it preserves the graphitic structure from damage during the milling process as well as acting as a solid-state nitrogen source. Based on the phase analysis, the d-spacing of MWCNT samples in the presence of urea decreased due to the mechanical force in the milling process as the milling time increased. On the other hand, in the graphite case, due to its open flat surface, the graphite (002) peak shifts toward lower two theta as the milling time increase. Such findings are important and could be used for large-scale production of N-doped graphene, diminishing the use of either dangerous chemicals or sophisticated equipment.

  20. 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.

  1. Metabolism of urea in kids fed different levels of urea molasses diets

    International Nuclear Information System (INIS)

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

    1981-01-01

    Urea entry rates were measured in the body pool of Barbari kids using a single injection isotope dilution technique. The kids were divided into five groups (T 1 , T 2 , T 3 , T 4 and T 5 ) and they were fed different levels of urea molasses viz., 10, 25, 35, 40 and 0 percent to meet their DCP requirement along with concentrate mixture and oat hay as per A.R.C. recommendation. Urea entry rate was significantly higher (P 1 and the control group (T 5 without urea in their diets) than that of T 2 , T 3 and T 4 which were not significantly different from each other. (author)

  2. Hydroponics versus field lysimeter studies of urea, ammonium and nitrate uptake by oilseed rape (Brassica napus L.).

    Science.gov (United States)

    Arkoun, Mustapha; Sarda, Xavier; Jannin, Laëtitia; Laîné, Philippe; Etienne, Philippe; Garcia-Mina, José-Maria; Yvin, Jean-Claude; Ourry, Alain

    2012-09-01

    N-fertilizer use efficiencies are affected by their chemical composition and suffer from potential N-losses by volatilization. In a field lysimeter experiment, (15)N-labelled fertilizers were used to follow N uptake by Brassica napus L. and assess N-losses by volatilization. Use of urea with NBPT (urease inhibitor) showed the best efficiency with the lowest N losses (8% of N applied compared with 25% with urea alone). Plants receiving ammonium sulphate, had similar yield achieved through a better N mobilization from vegetative tissues to the seeds, despite a lower N uptake resulting from a higher volatilization (43% of applied N). Amounts of (15)N in the plant were also higher when plants were fertilized with ammonium nitrate but N-losses reached 23% of applied N. In parallel, hydroponic experiments showed a deleterious effect of ammonium and urea on the growth of oilseed rape. This was alleviated by the nitrate supply, which was preferentially taken up. B. napus was also characterized by a very low potential for urea uptake. BnDUR3 and BnAMT1, encoding urea and ammonium transporters, were up-regulated by urea, suggesting that urea-grown plants suffered from nitrogen deficiency. The results also suggested a role for nitrate as a signal for the expression of BnDUR3, in addition to its role as a major nutrient. Overall, the results of the hydroponic study showed that urea itself does not contribute significantly to the N nutrition of oilseed rape. Moreover, it may contribute indirectly since a better use efficiency for urea fertilizer, which was further increased by the application of a urease inhibitor, was observed in the lysimeter study.

  3. The incidence of urea cycle disorders

    OpenAIRE

    Summar, Marshall L.; Koelker, Stefan; Freedenberg, Debra; Le Mons, Cynthia; Haberle, Johannes; Lee, Hye-Seung; Kirmse, Brian

    2013-01-01

    A key question for urea cycle disorders is their incidence. In the United States two UCDs argininosuccinic synthetase and lyase deficiency are currently detected by newborn screening. We used newborn screening data on over 6. million births and data from the large US and European longitudinal registries to determine how common these conditions are. The incidence for the United States is predicted to be 1 urea cycle disorder patient for every 35000 births presenting about 113 new patients per ...

  4. Serratia ureilytica sp. nov., a novel urea-utilizing species.

    Science.gov (United States)

    Bhadra, Bhaskar; Roy, Pradosh; Chakraborty, Ranadhir

    2005-09-01

    A Gram-negative, rod-shaped, urea-dissolving and non-spore-forming bacterium, designated strain NiVa 51(T), was isolated from water of the River Torsa in Hasimara, Jalpaiguri district, West Bengal, India. On the basis of 16S rRNA gene sequence similarity, strain NiVa 51(T) was shown to belong to the gamma-Proteobacteria and to be related to Serratia marcescens subsp. sakuensis (98.35%) and S. marcescens subsp. marcescens (98.30%); however, strain NiVa 51(T) exhibited only 43.7% similarity to S. marcescens by DNA-DNA hybridization. The G+C content of the genomic DNA of the isolate was 60 mol%. Both biochemical characteristics and fatty acid analysis data supported the affiliation of strain NiVa 51(T) to the genus Serratia. Furthermore, strain NiVa 51(T) was found to utilize urea as nitrogen source. The results of DNA-DNA hybridization as well as physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain NiVa 51(T) from recognized Serratia species. Strain NiVa 51(T) therefore represents a novel species, for which the name Serratia ureilytica sp. nov. is proposed, with type strain NiVa 51(T) (=LMG 22860(T)=CCUG 50595(T)).

  5. effects of nitrogen enrichment on heavy metals content of cattle dung ...

    African Journals Online (AJOL)

    Admin

    dung/poultry manure supplemented with 25 kg of urea (CDPMU) and (iii) cattle dung (CD) as ... Key words: Nitrogen Enrichment, Heavy Metals, Cattle Dung, Poultry Manure, Compost. .... available phosphorus, exchangeable bases and base.

  6. Profile of sodium phenylbutyrate granules for the treatment of urea-cycle disorders: patient perspectives

    Directory of Open Access Journals (Sweden)

    Peña-Quintana L

    2017-09-01

    Full Text Available Luis Peña-Quintana,1–3 Marta Llarena,2 Desiderio Reyes-Suárez,2 Luis Aldámiz-Echevarria4 1Pediatric Gastroenterology, Hepatology, and Nutrition Unit, Universitario Materno-Infantil Hospital de Canarias, University of Las Palmas de Gran Canaria, 2Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas, 3CIBEROBN, Madrid, 4Unit of Metabolism, Cruces University Hospital, BioCruces Health Research Institute, GCV-CIBER de Enfremedades Raras (CIBERER, Barakaldo, Spain Abstract: Urea-cycle disorders are a group of rare hereditary metabolic diseases characterized by deficiencies of one of the enzymes and transporters involved in the urea cycle, which is necessary for the removal of nitrogen produced from protein breakdown. These hereditary metabolic diseases are characterized by hyperammonemia and life-threatening hyperammonemic crises. Pharmacological treatment of urea-cycle disorders involves alternative nitrogen-scavenging pathways. Sodium benzoate combines with glycine and phenylacetate/phenylbutyrate with glutamine, forming, respectively, hippuric acid and phenylacetylglutamine, which are eliminated in the urine. Among the ammonia-scavenging drugs, sodium phenylbutyrate is a well-known long-term treatment of urea-cycle disorders. It has been used since 1987 as an investigational new drug, and was approved for marketing in the US in 1996 and the EU in 1999. However, sodium phenylbutyrate has an aversive odor and taste, which may compromise patients’ compliance, and many patients have reported difficulty in taking this drug. Sodium phenylbutyrate granules are a new tasteless and odor-free formulation of sodium phenylbutyrate, which is indicated in the treatment of urea-cycle disorders. This recently developed taste-masked formulation of sodium phenylbutyrate granules was designed to overcome the considerable issues that taste has on adherence to therapy. Several studies have reported the

  7. Effects of nitrogen sources on phosphorus absorption by wheat

    International Nuclear Information System (INIS)

    Muraoka, T.

    1983-01-01

    The effects of two sources of phosphorus (concentrated superphosphate and DAP) and ammonium sulfate, urea and ammonium nitrate on the phosphorus uptake by wheat plant were studied, utilizing superphosphate and DAP labelled with 23 P. It was observeded that the absorption of phosphrorus was influenced by the sources of nitrogen utilized. The best effect was obtained with urea, followed by ammonium nitrate and ammonium sulfate. It is suggested that the best effect of urea was due to its increasing effect on soil pH. (Author) [pt

  8. 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.

  9. Measurement of synovial fluid volume using urea.

    Science.gov (United States)

    Kraus, V B; Stabler, T V; Kong, S Y; Varju, G; McDaniel, G

    2007-10-01

    To examine the utility of using urea concentrations for determining Synovial Fluid (SF) joint volume in effused and non-effused joints. Knee joint SF was aspirated from 159 human study participants with symptomatic osteoarthritis of at least one knee either directly (165 knees) or by lavage (110 knees). Serum was obtained immediately prior to SF aspiration. Participants were asked to rate individual knee pain, aching or stiffness. SF and serum urea levels were determined using a specific enzymatic method run on an automated CMA600 analyzer. Cell counts were performed on direct SF aspirates when volume permitted. The formula for calculating SF joint volume was as follows: V(j)=C(D)(V(I))/(C-C(D)) with V(j)=volume of SF in entire joint, C(D)=concentration of urea in diluted (lavage) SF, V(I)=volume of saline injected into joint, and C=concentration of urea in undiluted (neat) SF derived below where C=0.897(C(S)) and C(s)=concentration of urea in serum. There was an excellent correlation (r(2)=0.8588) between SF and serum urea in the direct aspirates with a ratio of 0.897 (SF/serum). Neither urea levels nor the SF/serum ratio showed any correlation with Kellgren Lawrence (KL) grade, or cell count. While urea levels increased with age there was no change in the ratio. Intraarticular SF volumes calculated for the lavaged knees ranged from 0.555 to 71.71ml with a median volume of 3.048ml. There was no correlation of SF volume to KL grade but there was a positive correlation (P=0.001) between SF volume and self-reported individual knee pain. Our urea results for direct aspirates indicate an equilibrium state between serum and SF with regard to the water fraction. This equilibrium exists regardless of disease status (KL grade), inflammation (cell count), or age, making it possible to calculate intraarticular volume of lavaged joints based upon this urea method. Most of the joint volumes we calculated fell within the previously reported range for normal knees of 0.5-4.0ml

  10. Standardization of the TRUE Test imidazolidinyl urea and diazolidinyl urea patches

    DEFF Research Database (Denmark)

    Agner, T; Andersen, Klaus Ejner; Björkner, B

    2001-01-01

    The preservatives imidazolidinyl urea (IMID, Germall 115) and diazolidinyl urea (DU, Germall II) are commonly used in cosmetic products and are well-known sensitizers. The aim of the present study was to establish the optimal patch test concentration in hydrophilic dried-in vehicle (TRUE Test...

  11. Thermoplastic poly(urethane urea)s from novel, bio-based amorphous polyester diols

    NARCIS (Netherlands)

    Tang, D.; Noordover, B.A.J.; Sablong, R.J.; Koning, C.E.

    2012-01-01

    In this study, two novel, bio-based, amorphous polyester diols, namely poly(1,2-dimethylethylene adipate) (PDMEA) and poly(1,2-dimethylethylene succinate) (PDMES) are used to prepare thermoplastic poly(urethane urea)s (TPUUs). Interestingly, the TPUUs based on PDMEA show similar thermal and

  12. Clinical chemistry measurements with commercially available test slides on a smartphone platform: Colorimetric determination of glucose and urea.

    Science.gov (United States)

    Wu, Yuanyuan; Boonloed, Anukul; Sleszynski, Neal; Koesdjojo, Myra; Armstrong, Chadd; Bracha, Shay; Remcho, Vincent T

    2015-08-25

    Rapidly increasing healthcare costs in economically advantaged countries are currently unsustainable, while in many developing nations, even 50-year-old technologies are too expensive to implement. New and unconventional technologies are being explored as solutions to this problem. In this study, we examined the use of a smartphone as the detection platform for 2 well-developed, relatively inexpensive, commercially available clinical chemistry assays as a model for rapid and inexpensive clinical diagnostic testing. An Apple iPhone 4 camera phone equipped with a color analysis application (ColorAssist) was combined with Vitros® glucose and urea colorimetric assays. Color images of assay slides at various concentrations of glucose or urea were collected with the iPhone 4 and quantitated in three different spectral ranges (red/green/blue or RGB) using the ColorAssist app. When the diffuse reflectance data was converted into absorbance, it was possible to quantitate glucose or blood urea nitrogen (BUN) over their clinically important concentration ranges (30-515mg/dl for glucose or 2-190mg/dl for BUN), with good linearity (R(2)=0.9994 or 0.9996, respectively [n=5]). Data collected using the iPhone 4 and canine serum samples were in agreement with results from the instrumental "gold standard" (Beckman Coulter AU480 Chemistry System) (R(2)=0.9966 and slope=1.0001 for glucose; R(2)=0.9958 and slope=0.9454 for BUN). Glucose determinations of serum samples made using this smartphone method were as accurate as or more accurate than a commercial colorimetric dry slide analyzer (Heska® Element DC Chemistry Analyzer, Loveland, CO) and 2 glucometers: ReliOn® Ultima (Abbott Diabetes Care Inc) and Presto® (AgaMatrix Inc.H). BUN determinations made using the smartphone approach were comparable in accuracy to the Heska instrument. This demonstration shows that smartphones have the potential to be used as simple, effective colorimetric detectors for quantitative diagnostic tests

  13. Consumo, desempenho e parâmetros econômicos de novilhos Nelore e F1 Brangus x Nelore terminados em pastagens, suplementados com mistura mineral e sal nitrogenado com uréia ou amiréia Feed intake, performance and profitability of Nellore and crossbred (Brangus x Nellore steers finished in pastures, supplemented with mineralized salt and nitrogenous salt with urea or starea

    Directory of Open Access Journals (Sweden)

    L.C.V. Ítavo

    2008-04-01

    Full Text Available Avaliou-se o efeito da suplementação protéica (40% PB com amiréia ou uréia sobre o consumo de suplemento, desempenho e características econômicas de novilhos terminados em pastagens. Foram utilizados 120 novilhos com 19 meses de idade e 358kg, sendo 60 Nelore e 60 F1 Brangus x Nelore, divididos em três tratamentos com 20 animais, alojados em piquetes de Brachiaria brizantha cv. Marandu de 10 hectares cada, totalizando 120 hectares, sendo dois piquetes por grupo genético e tratamento, pastejados alternadamente a cada pesagem (42 dias. Os tratamentos consistiram em mistura mineral com amiréia-150S (AM, mistura mineral com uréia+milho+enxofre (UR e mistura mineral (MM. As médias de consumo de suplemento dos animais F1 foram de 206,1; 145,9 e 73,1g/dia, e as dos animais Nelore, 236,0; 205,1 e 94,3g/dia para os tratamentos AM, UR e MM, respectivamente. Para os novilhos Nelore, houve efeito (PThe effects of protein supplementation of finishing grazing steers by feeding nitrogenous salts (40% CP, urea or starea or mineralized salt only on supplement intake, growing performance and profitability were evaluated. One hundred and twenty steers (60 Nellore and 60 Brangus x Nellore, 19-month old, 358kg BW were divided in 12 equal groups which were allotted to one of 12 Brachiaria brizantha pastures (10-ha each performing two pastures for each breeding group and nutritional treatment. Groups were allowed to graze each pasture for 42 days when they were randomly moved into a new one. Nutritional treatments were as follow: MS - mineralized salt only; ST -mineralized salt plus starea - 150S; and UR - mineralized salt plus urea, corn and sulphur. UR supplement was prepared mixing the same ingredient contents of ST. Crossbred steers consumed 206.1; 145.9 and 73.1g/day whereas Nellore steers consumed 236.0; 205.11 and 94.29g/day of ST, UR and MS; respectively. For Nellore steers, UR increased slaughter weight (518.8kg compared to ST and MS (491.9 and

  14. Polymer-Coated Urea Delays Growth and Accumulation of Key Nutrients in Aerobic Rice but Does Not Affect Grain Mineral Concentrations

    Directory of Open Access Journals (Sweden)

    Terry J. Rose

    2016-01-01

    Full Text Available Enhanced efficiency nitrogen (N fertilizers (EEFs may improve crop recovery of fertilizer-N, but there is evidence that some EEFs cause a lag in crop growth compared to growth with standard urea. Biomass and mineral nutrient accumulation was investigated in rice fertilized with urea, urea-3,4-dimethylpyrazole phosphate (DMPP and polymer-coated urea (PCU to determine whether any delays in biomass production alter the accumulation patterns, and subsequent grain concentrations, of key mineral nutrients. Plant growth and mineral accumulation and partitioning to grains did not differ significantly between plants fertilized with urea or urea-DMPP. In contrast, biomass accumulation and the accumulation of phosphorus, potassium, calcium, magnesium, copper, zinc and manganese were delayed during the early growth phase of plants fertilized with PCU. However, plants in the PCU treatment ultimately compensated for this by increasing growth and nutrient uptake during the latter vegetative stages so that no differences in biomass or nutrient accumulation generally existed among N fertilizer treatments at anthesis. Delayed biomass accumulation in rice fertilized with PCU does not appear to reduce the total accumulation of mineral nutrients, nor to have any impact on grain mineral nutrition when biomass and grain yields are equal to those of rice grown with urea or urea-DMPP.

  15. Exogenous application of urea and a urease inhibitor improves drought stress tolerance in maize (Zea mays L.).

    Science.gov (United States)

    Gou, Wei; Zheng, Pufan; Tian, Li; Gao, Mei; Zhang, Lixin; Akram, Nudrat Aisha; Ashraf, Muhammad

    2017-05-01

    Drought is believed to cause many metabolic changes which affect plant growth and development. However, it might be mitigated by various inorganic substances, such as nitrogen. Thus, the study was carried out to investigate the effect of foliar-applied urea with or without urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) on a maize cultivar under drought stress simulated by 15% (w/v) polyethylene glycol 6000. Foliar-applied urea resulted in a significant increase in plant dry weight, relative water content, and photosynthetic pigments under water stress condition. Furthermore, the activities of superoxide dismutase (SOD), peroxidase (POD), and hydrogen peroxidase (CAT), were enhanced with all spraying treatments under drought stress, which led to decreases in accumulation of hydrogen peroxide (H 2 O 2 ), superoxide anion ([Formula: see text]) and malondialdehyde (MDA). The contents of soluble protein and soluble sugar accumulated remarkably with urea-applied under drought stress condition. Moreover, a further enhancement in above metabolites was observed by spraying a mixture of urea and urease inhibitor as compared to urea sprayed only. Taken together, our findings show that foliar application of urea and a urease inhibitor could significantly enhance drought tolerance of maize through protecting photosynthetic apparatus, activating antioxidant defense system and improving osmoregulation.

  16. Rumen volatile fatty acids and milk composition from cows fed hay, haylage, or urea-treated corn silage.

    Science.gov (United States)

    Schingoethe, D J; Voelker, H H; Beardsley, G L; Parsons, J G

    1976-05-01

    Alfalfa-brome hay, haylage, .5% urea-treated corn silage, or .5% urea plus 1% dried whey-treated corn silage was fed as the only forage to one of four groups of 10 lactating cows per group for a lactation trial of 10 wk. Rumen samples were collected via stomach tube 3 to 4 h after the morning feeding. The pH of the rumen samples from cows fed hay was higher than for cows fed haylage, urea-treated corn silage, and urea-whey corn silage, 6.69 versus 6.36, 6.40, and 6.50. Total volatile fatty acids and propionate were highest from cows fed urea-whey corn silage and were higher on all three fermented forages than cows fed hay. Acetate/propionate ratio was highest from cows fed hay and lowest from cows fed corn silages. Butyrate was highest from cows fed haylage or hay. Milk protein composition was not affected by ration although nonprotein nitrogen of milk was highest from cows fed the urea-treated corn silages. Oleic acid and total unsaturated fatty acids were lowest in milk fat from cows fed hay while palmitic acid was highest from cows fed hay and haylage. These results suggest that type of forage fed may cause small changes in rumen fermentation and in milk composition. The importance of these changes is unknown but may affect properties of dairy products produced from this milk.

  17. Preparation of carbon dioxide adsorbents from the chemical activation of urea-formaldehyde and melamine-formaldehyde resins

    Energy Technology Data Exchange (ETDEWEB)

    T.C. Drage; A. Arenillas; K.M. Smith; C. Pevida; S. Piippo; C.E. Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2007-01-15

    Adsorption is considered to be one of the more promising technologies for the capture of CO{sub 2} from flue gases. In general, nitrogen enrichment is reported to be effective in enhancing the specific adsorbent-adsorbate interaction for CO{sub 2}. Nitrogen enriched carbons were produced from urea-formaldehyde and melamine-formaldehyde resins polymerised in the presence of K{sub 2}CO{sub 3} as a chemical activation agent, with activation undertaken over a range of temperatures. CO{sub 2} adsorption capacity was determined to be dependent upon both textural properties and more importantly nitrogen functionality. Adsorbents capable of capturing above 8 wt.% CO{sub 2} at 25{sup o}C were produced from the chemical activation of urea-formaldehyde resin at 500{sup o}C. Chemical activation seems to produce more effective adsorbents than CO{sub 2} activation. 29 refs., 4 figs., 3 tabs.

  18. Urea concentration in sheep’s milk

    Directory of Open Access Journals (Sweden)

    Jasmina Havranek

    2009-03-01

    Full Text Available Determining urea concentration in milk is a useful indicator for controlling supply of proteins to organisms, as well as the relationship of energy and protein in the food, thus it is finding more and more ways of practical use. The concentration of urea in milk, along with the feeding process, is influenced by a number of other factors such as: breed, stage and sequence of lactation, body mass, daily production and chemical structure of milk, number of somatic cells, season, milking.The goal of the research was to establish the influence of the breed (Island of Krk, East Frisian, lactation stage (beginning, middle and the end and the herd (3 to the concentration of urea in milk during lactation.For each breed there has been established daily quantity of milk, protein share and the concentration of urea in milk.Statistical analysis of data was conducted by using General Linear Models procedure, SAS program system (1999.The breed of sheep considerably (P<0.001 influenced daily quantity of milk, protein share and the concentration of urea in the milk.East Frisian sheep produced on average almost double the daily quantities of milk (1070 mL compared to the Krk sheep (588 mL.Protein share and the urea concentration in Krk sheep milk were higher (5.99 % and 35.97 mg/100 mL then in the milk of East Frisian sheep (5.12 % and 33.31 mg/100 mL.For both breeds the significant influence of lactation stage to the daily milk quantity has been established (0.001, that is also for the urea concentration in the milk of Krk sheep (0.001, as well as protein share in the milk of East Frisian sheep (0.001.Herd influence significantly affected daily milk quantities (0.001 and concentration of urea in the milk (0.05.The defining of the urea concentration in sheep milk should be occasionally carried out in the Republic of Croatia to establish the standard physiological values typical for the particular sheep breed.

  19. Catalytic/non-catalytic combination process for nitrogen oxides reduction

    International Nuclear Information System (INIS)

    Luftglass, B.K.; Sun, W.H.; Hofmann, J.E.

    1992-01-01

    This patent describes a process for the reduction of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. It comprises introducing a nitrogenous treatment agent comprising urea, one or more of the hydrolysis products of urea, ammonia, compounds which produce ammonia as a by-product, ammonium salts of organic acids, 5- or 6-membered heterocyclic hydrocarbons having at least one cyclic nitrogen, hydroxy amino hydrocarbons, or mixtures thereof into the effluent at an effluent temperature between about 1200 degrees F and about 2100 degrees F; and contacting the treated effluent under conditions effective to reduce the nitrogen oxides in the effluent with a catalyst effective for the reduction of nitrogen oxides in the presence of ammonia

  20. Photoluminescence of urea- and urea/rhodamine B-capped TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalo-Juan, I., E-mail: gonzalo@materials.tu-darmstadt.de; Macé, L.; Tengeler, S.; Mosallem, A.; Nicoloso, N.; Riedel, R.

    2016-07-01

    Urea- and rhodamine B (RhB)-capped TiO{sub 2} nanoparticles (NPs) have been prepared by solvothermal synthesis and characterized by HRTEM, XRD, FTIR, XPS, optical absorption and photoemission. The urea and urea/RhB ligands are capped to the surface of the TiO{sub 2} NPs for the first time through carbamate bonding. The band gap of TiO{sub 2} is slightly reduced from 3.1 eV to 3.0 eV in the urea capped TiO{sub 2} NPs (TU) and 2.9 eV for the NPs capped with urea/RhB (TUR). The generation of new trapping states in TU and TUR at the conduction band edges (surface oxygen vacancies) has been confirmed by the Urbach law providing tail state energies of 180 meV and 270 meV, respectively. These tail states are considered to be responsible for the strong reduction of the photoluminescence at ≈400 nm and the increased emission at ≈600 nm in TU and TUR. The findings suggest that urea- and RhB-capped TiO{sub 2} NPs could have potential applications as photocatalysts, opto-electronic devices, sensors, biological labels and anti-bacterial agents. - Highlights: • Urea- and urea/rhodamine B (RhB)-capped TiO{sub 2} nanoparticles preparation. • Characterization of optical properties of urea- and urea/rhodamine B (RhB)-capped TiO{sub 2} nanoparticles. • The recombination of electrons and holes is significantly reduced in the capped TiO{sub 2} nanoparticles, in comparison with TiO{sub 2}.

  1. Post-dialysis urea concentration: comparison between one- compartment model and two-compartment model

    International Nuclear Information System (INIS)

    Tamrin, N S Ahmad; Ibrahim, N

    2014-01-01

    The reduction of the urea concentration in blood can be numerically projected by using one-compartment model and two-compartment model with no variation in body fluid. This study aims to compare the simulated values of post-dialysis urea concentration for both models with the clinical data obtained from the hospital. The clinical assessment of adequacy of a treatment is based on the value of Kt/V. Further, direct calculation using clinical data and one-compartment model are presented in the form of ratio. It is found that the ratios of postdialysis urea concentration simulated using two-compartment model are higher compared to the ratios of post-dialysis urea concentration using one-compartment model. In addition, most values of post-dialysis urea concentration simulated using two-compartment model are much closer to the clinical data compared to values simulated using one-compartment model. Kt/V values calculated directly using clinical data are found to be higher than Kt/V values derived from one-compartment model

  2. Improvement of Soybean (Glycine max L. Yield with Urea Foliar Application at Growth Stages

    Directory of Open Access Journals (Sweden)

    Mahmood Tohidi

    2017-07-01

    Full Text Available To investigate the effects of nitrogen foliar application at different growth stages of soybean on the yield and yield components this experiment was performed in Shush, north of Khuzestan, Iran, during growing season of 2014. The experiment was in split plot based on randomized complete block design with three replications. Experimental treatments consisted of four levels of nitrogen fertilizer foliar applications as control (no nitrogen foliar application, 25, 50 and 75 kg/ha pure nitrogen from urea source (46% pure nitrogen assigned to the main plots and spraying times in three levels, at vegetative stage, flowering stage and podding stage to the subplots. Results showed that the effects of nitrogen foliar application on traits measured in this experiment like leaf area index, number of pod per plant, number of seeds per pod, thousand seed weight, seed yield, biologic yield, harvest index, protein percent and protein yield and also interaction of different levels of nitrogen foliar application and different growth stages, were significant. Oil percent and yield were only significant under the effect of nitrogen foliar application treatments at different growth stages while the interaction of different levels of nitrogen foliar application and different growth stages, were not significant. In this experiment nitrogen foliar application increased seed yield. The highest seed yield amounted to 2466 kg/ha when 50kg/ha of foliar nitrogen applied at vegetative growth stage and lowest seed yield amounted to 1295 kg/ha in the control treatment at the stage of podding. In general, results demonstrated that 50 kg/ha treatment could be considered as the best management option of nitrogen foliar application for soybean at vegetative growth stage.

  3. Ammonia and carbon dioxide emissions by stabilized conventional nitrogen fertilizers and controlled release in corn crop

    Directory of Open Access Journals (Sweden)

    Taylor Lima de Souza

    Full Text Available ABSTRACT The market of stabilized, slow and controlled release nitrogen (N fertilizers represents 1% of the world fertilizer consumption. On the other hand, the increase in availability, innovation and application of these technologies could lead to the improvement of N use efficiency in agroecossystems and to the reduction of environmental impacts. The objective of this study was to quantify agronomic efficiency relative index, ammonia volatilization, and CO2 emissions from conventional, stabilized and controlled release N fertilizers in corn summer crop. The experiment was carried out in a corn crop area located in Lavras, state of Minas Gerais, Brazil, without irrigation. All treatments were applied in topdressing at rate of 150 kg ha-1 N. N-NH3 losses from N fertilizers were: Granular urea (39% of the applied N = prilled urea (38% > urea coated with 16% S0 (32% = blend of urea + 7.9% S0 + polymers + conventional urea (32% > prilled urea incorporated at 0.02 m depth (24% > urea + 530 mg kg-1 of NBPT (8% = Hydrolyzed leather (9% > urea + thermoplastic resin (3% = ammonium sulfate (1% = ammonium nitrate (0.7%. Thermoplastic resin coated urea, ammonium nitrate and ammonium sulfate presented low values of cumulative CO2 emissions in corn crop. On the other hand, hydrolyzed leather promoted greater C-CO2 emission, when compared with other nitrogen fertilizers.

  4. Toward Understanding Mechanisms Controlling Urea Delivery in a Coastal Plain Watershed

    Science.gov (United States)

    Tzilkowski, S. S.; Buda, A. R.; Boyer, E. W.; Bryant, R. B.; May, E. B.

    2012-12-01

    Improved understanding of nutrient mobilization and delivery to surface waters is critical to protecting water quality in agricultural watersheds. Urea, a form of organic nitrogen, is a common nutrient found in fertilizers, manures, and human waste, and is gaining recognition as an important driver of coastal eutrophication, particularly through the development of harmful algal blooms. While several studies have documented elevated urea concentrations in tributaries draining to the Chesapeake Bay, little is known about the potential sources and flow pathways responsible for urea delivery from the landscape to surface waters, as well as how these sources and pathways might vary with changing seasons, antecedent conditions, and storm types. In this study, we investigated hydrologic controls on urea delivery in the Manokin River watershed through the analysis of urea concentration dynamics and hysteresis patterns during seven storm events that occurred in 2010 and 2011. The Manokin River is a Coastal Plain watershed (11.1 km2) on the Delmarva Peninsula that drains directly to the Chesapeake Bay and is characterized by extensive rural development coupled with intensive agriculture, particularly poultry production. Sampling was conducted through monthly grab sampling at baseflow conditions and by time-weighted, automated (Sigma) samplers during stormflow events. Monitored storms were chosen to represent a spectrum of antecedent conditions based on precipitation and groundwater levels in the area. Flushing from the landscape during events was found to be the predominant urea delivery mechanism, as urea concentrations increased 3-9 times above baseflow concentrations during storms. The timing and number of flushes, as well as the degree of increased concentrations were dependent on antecedent conditions and the characteristics of the storm event. For instance, during an intense (13.7 mm hr-1), short-duration (4 hrs) storm in August of 2010 when antecedent conditions were

  5. Biochemical markers and neuropsychological functioning in distal urea cycle disorders.

    Science.gov (United States)

    Waisbren, Susan E; Cuthbertson, David; Burgard, Peter; Holbert, Amy; McCarter, Robert; Cederbaum, Stephen

    2018-02-08

    Urea cycle disorders often present as devastating metabolic conditions, resulting in high mortality and significant neuropsychological damage, despite treatment. The Urea Cycle Disorders Longitudinal Study is a natural history study that collects data from regular clinical follow-up and neuropsychological testing. This report examines links between biochemical markers (ammonia, glutamine, arginine, citrulline) and primary neuropsychological endpoints in three distal disorders, argininosuccinic acid synthetase deficiency (ASD or citrullinemia type I), argininosuccinic acid lyase deficiency (ASA or ALD), and arginase deficiency (ARGD). Laboratory results and test scores from neuropsychological evaluations were assessed in 145 study participants, ages 3 years and older, with ASD (n = 64), ASA (n = 65) and ARGD (n = 16). Mean full scale IQ was below the population mean of 100 ± 15 for all groups: (ASD = 79 ± 24; ASA = 71 ± 21; ARGD = 65 ± 19). The greatest deficits were noted in visual performance and motor skills for all groups. While ammonia levels remain prominent as prognostic biomarkers, other biomarkers may be equally valuable as correlates of neuropsychological functioning. Cumulative exposure to the biomarkers included in the study proved to be highly sensitive indicators of neuropsychological outcomes, even when below the cut-off levels generally considered toxic. Blood levels of biomarkers obtained on the day of neuropsychological evaluations were not correlated with measures of functioning for any disorder in any domain. The importance of cumulative exposure supports early identification and confirms the need for well-controlled management of all biochemical abnormalities (and not just ammonia) that occur in urea cycle disorders.

  6. Remote calorimetric detection of urea via flow injection analysis.

    Science.gov (United States)

    Gaddes, David E; Demirel, Melik C; Reeves, W Brian; Tadigadapa, Srinivas

    2015-12-07

    The design and development of a calorimetric biosensing system enabling relatively high throughput sample analysis are reported. The calorimetric biosensor system consists of a thin (∼20 μm) micromachined Y-cut quartz crystal resonator (QCR) as a temperature sensor placed in close proximity to a fluidic chamber packed with an immobilized enzyme. Layer by layer enzyme immobilization of urease is demonstrated and its activity as a function of the number of layers, pH, and time has been evaluated. This configuration enables a sensing system where a transducer element is physically separated from the analyte solution of interest and is thereby free from fouling effects typically associated with biochemical reactions occuring on the sensor surface. The performance of this biosensing system is demonstrated by detection of 1-200 mM urea in phosphate buffer via a flow injection analysis (FIA) technique. Miniaturized fluidic systems were used to provide continuous flow through a reaction column. Under this configuration the biosensor has an ultimate resolution of less than 1 mM urea and showed a linear response between 0-50 mM. This work demonstrates a sensing modality in which the sensor itself is not fouled or contaminated by the solution of interest and the enzyme immobilized Kapton® fluidic reaction column can be used as a disposable cartridge. Such a system enables reuse and reliability for long term sampling measurements. Based on this concept a biosensing system is envisioned which can perform rapid measurements to detect biomarkers such as glucose, creatinine, cholesterol, urea and lactate in urine and blood continuously over extended periods of time.

  7. 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.

  8. Blood biochemical parameters, nitrogen balance and gross energy metabolizability in pigs fed with different dietary electrolyte balancesParâmetros bioquímicos sanguíneos, balanço de nitrogênio e metabolizabilidade da energia bruta em suínos alimentados com dietas contendo diferentes balanços eletrolíticos

    Directory of Open Access Journals (Sweden)

    Luís Daniel Giusti Bruno

    2012-08-01

    Full Text Available The aim of this study was to evaluate different dietary electrolyte balance (DEB on the blood biochemical parameters, nitrogen balances and crude metabolizable energy of swine in the initial phase. Sixteen barrows were used, averaging 27.95 kg of initial weight, allotted individually in metabolic cages in a randomized blocks design with four treatments (DEB of 160, 208, 257 and 305 mEq/kg and 4 replicates. The blood biochemical parameters analyzed were chloride, potassium, sodium and urea in blood. Urine pH was also evaluated, and the parameters evaluated in nitrogen (N balance were N intake, fecal N, N excreted in urine, absorbed N, N retention, retained N/absorbed N and total excretion of N. The gross energy digestibility and metabolizibility coefficients were determined, and the respectives values of digestible and metabolizable energy. The values of urinary pH increased (P 0.05 between the evaluated DEB. A linear increase (P Objetivou-se com esse trabalho avaliar diferentes balanços eletrolíticos das dietas (BED sobre os parâmetros bioquímicos sanguíneos, balanços de nitrogênio e a metabolizabilidade da energia bruta, de suínos na fase inicial. Foram utilizados 16 suínos, machos castrados, com peso inicial de 27,95 kg, distribuídos individualmente em gaiolas metabólicas, em um delineamento experimental em blocos ao acaso com quatro tratamentos (BED de 160, 208, 257 e 305 mEq/kg e quatro repetições. Os parâmetros bioquímicos sanguíneos avaliados foram cloretos, potássio, sódio e uréia no soro. O pH da urina também foi avaliado, e as variáveis utilizadas no balanço de nitrogênio (N foram o N ingerido, N excretado nas fezes, N excretado na urina, N absorvido, N retido, N retido/N absorvido e excreção total de N. Foram determinados os coeficientes de digestibilidade e metabolizabilidade da energia bruta e seus respectivos valores de energia digestível e metabolizável. Os valores de pH urinário aumentaram (P 0,05 entre

  9. Transcriptomic analyses of nitrogen assimilation processes in a Chinese strain of Aureococcus anophagefferens

    Directory of Open Access Journals (Sweden)

    Li-Na Chen

    2015-09-01

    Full Text Available Aureococcus anophagefferens is a harmful alga that dominates plankton communities during brown tides in North America, Africa, and Asia. In order to figure out the processes of nitrogen assimilation in a Chinese strain of A. anophagefferens, RNA-seq technology was used to examine transcriptomic differences in A. anophagefferens that was grown on urea, nitrate, or a mixture of urea and nitrate, and that was under N-replete, limited and recovery conditions. We noted that transcripts upregulated by nitrate and N-limitation included those encoding proteins involved in amino acid, nucleotide and aminosugar 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 cycle (OUC and TCA cycle 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. Here, we provide the experimental procedures and analytical processes in detail. The data set is deposited in GEO with the accession number GSE60576.

  10. A perfusion study of the handling of urea and urea analogues by the gills of the dogfish shark (Squalus acanthias).

    Science.gov (United States)

    Wood, Chris M; Liew, Hon Jung; De Boeck, Gudrun; Walsh, Patrick J

    2013-01-01

    The branchial mechanism of urea retention in elasmobranchs was investigated using an in vitro isolated-perfused head preparation, as well as in vivo samples, in the spiny dogfish shark. Both in vivo and in control saline perfusions containing 350 mmol L(-1) urea, calculated intracellular urea concentrations in gill epithelial cells were close to extracellular concentrations. Urea efflux to the external water fell only non-significantly, and calculated gill intracellular urea concentration did not change when perfusate urea concentration was reduced from 350 to 175 mmol L(-1) with osmotic compensation by 175 mmol L(-1) mannitol. However, when the urea analogues thiourea or acetamide were present in the perfusate at concentrations equimolar (175 mmol L(-1)) to those of urea (175 mmol L(-1)), urea efflux rates were increased 4-fold and 6.5-fold respectively, and calculated gill intracellular urea concentrations were depressed by about 55%. Analogue efflux rates were similar to urea efflux rates. Previous studies have argued that either the basolateral or apical membranes provided the limiting permeability barrier, and/or that a back-transporter on the basolateral membranes of gill cells is responsible for urea retention. The present results provide new evidence that the apical membrane is the limiting factor in maintaining gill urea impermeability, and raise the prospect that a urea back-transporter, which can be competitively inhibited by thiourea and acetamide, operates at the apical membrane.

  11. A perfusion study of the handling of urea and urea analogues by the gills of the dogfish shark (Squalus acanthias

    Directory of Open Access Journals (Sweden)

    Chris M. Wood

    2013-02-01

    Full Text Available The branchial mechanism of urea retention in elasmobranchs was investigated using an in vitro isolated-perfused head preparation, as well as in vivo samples, in the spiny dogfish shark. Both in vivo and in control saline perfusions containing 350 mmol L−1 urea, calculated intracellular urea concentrations in gill epithelial cells were close to extracellular concentrations. Urea efflux to the external water fell only non-significantly, and calculated gill intracellular urea concentration did not change when perfusate urea concentration was reduced from 350 to 175 mmol L−1 with osmotic compensation by 175 mmol L−1 mannitol. However, when the urea analogues thiourea or acetamide were present in the perfusate at concentrations equimolar (175 mmol L−1 to those of urea (175 mmol L−1, urea efflux rates were increased 4-fold and 6.5-fold respectively, and calculated gill intracellular urea concentrations were depressed by about 55%. Analogue efflux rates were similar to urea efflux rates. Previous studies have argued that either the basolateral or apical membranes provided the limiting permeability barrier, and/or that a back-transporter on the basolateral membranes of gill cells is responsible for urea retention. The present results provide new evidence that the apical membrane is the limiting factor in maintaining gill urea impermeability, and raise the prospect that a urea back-transporter, which can be competitively inhibited by thiourea and acetamide, operates at the apical membrane.

  12. Influence of the form and rate of 15N-labelled nitrogen fertilizers on nitrogen uptake by maize grown on two different soils

    International Nuclear Information System (INIS)

    Balabanova-Georgieva, R.; Ikonomova, E.

    1996-01-01

    The influence of 15 N-labelled urea and ammonium sulfate on the yield and uptake of fertilizer nitrogen and soil nitrogen by maize was studied under the conditions of pot experiments on calcareous black earth and leached black earth. The nitrogen fertilizers were applied in rates: N 1 =250 mg, N 2 =500 mg, N 3 =750 mg and N 4 =1000 mg/1 kg of soil, on phosphorus(P)-potassium(K) background (P=200 and K=600 mg/kg soil). When treating with N 3 and N 4 , the application of the whole nitrogen rate was compared with its split application. It was found that the form of the nitrogen fertilizer played no important role for the formation of the yield of biomass and the uptake of nitrogen with the yield when it is applied in low nitrogen rates and maize was grown on calcareous black earth. The yield of biomass and the uptake of nitrogen with the yield of maize reach their maximum under the conditions of calcareous black earth and high nitrogen rates applied as urea depressed the plants which proves the statement that in case of calcareous black earth application of ammonium sulfate should be preferred rather that urea, fertilization with which should be avoided. No depression of plants was observed under the conditions of leached black earth and application of high urea rates. The amount of nitrogen taken up is growing with the increasing of the nitrogen rate (excluding the N-treatment). The split application of high nitrogen rates increased notably the yield of maize-vegetation mass which proved the great ability of this crop for effective utilization of the nitrogen fertilizers when applied in portions and at suitable phases of plant vegetation. The role of the fertilizer nitrogen on the formation of the plant mass yield is much greater compared to that of the soil nitrogen; in the split application of urea the soil nitrogen plays a much bigger role than in its single application. The additional mobilization of the soil nitrogen under the influence of the applied nitrogen

  13. Qualitative parameters of sugarcane silages treated with urea and calcium oxide

    Directory of Open Access Journals (Sweden)

    Susi Cristina dos Santos Guimarães Martins

    2015-04-01

    Full Text Available The objective was to evaluate the fermentation parameters, chemical composition and fractionation of carbohydrates of sugarcane silages treated with urea and calcium oxide (CaO. Upon ensiling, the treatments applied to the sugarcane were: 1% urea; 0.5% urea + 0.5% CaO; and 1% CaO, in relation to a control silage, without additive. The chemical additives (urea and CaO were added at ensiling, in an amount calculated based on the fresh matter (as is. A completely randomized design consisting of four treatments (silages and nine replicates was adopted. The material was conditioned in PVC mini-silos for five months. At the end of the storage period, silos were weighed again and samples were collected to quantify the losses caused by fermentation, dry matter recovery, pH, and ammonia nitrogen (N-NH3 of the silages and to evaluate the chemical composition and fractionation of carbohydrates. The silage with 1% CaO showed the highest recovery of dry matter, and in terms of carbohydrate fractionation, it showed the highest levels of soluble and potentially soluble carbohydrates. Addition of 1% CaO during ensiling reduces the fermentation losses of sugarcane silages.

  14. Lactobacillus reuteri 100-23 modulates urea hydrolysis in the murine stomach.

    Science.gov (United States)

    Wilson, Charlotte M; Loach, Diane; Lawley, Blair; Bell, Tracey; Sims, Ian M; O'Toole, Paul W; Zomer, Aldert; Tannock, Gerald W

    2014-10-01

    Comparisons of in vivo (mouse stomach) and in vitro (laboratory culture) transcriptomes of Lactobacillus reuteri strain 100-23 were made by microarray analysis. These comparisons revealed the upregulation of genes associated with acid tolerance, including urease production, in the mouse stomach. Inactivation of the ureC gene reduced the acid tolerance of strain 100-23 in vitro, and the mutant was outcompeted by the wild type in the gut of ex-Lactobacillus-free mice. Urine analysis showed that stable isotope-labeled urea, administered by gavage, was metabolized to a greater extent in Lactobacillus-free mice than animals colonized by strain 100-23. This surprising observation was associated with higher levels of urease activity and fecal-type bacteria in the stomach digesta of Lactobacillus-free mice. Despite the modulation of urea hydrolysis in the stomach, recycling of urea nitrogen in the murine host was not affected since the essential amino acid isoleucine, labeled with a stable isotope, was detected in the livers of both Lactobacillus-free and 100-23-colonized animals. Therefore, our experiments reveal a new and unexpected impact of Lactobacillus colonization on urea hydrolysis in the murine gut. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  15. The incidence of urea cycle disorders.

    Science.gov (United States)

    Summar, Marshall L; Koelker, Stefan; Freedenberg, Debra; Le Mons, Cynthia; Haberle, Johannes; Lee, Hye-Seung; Kirmse, Brian

    2013-01-01

    A key question for urea cycle disorders is their incidence. In the United States two UCDs, argininosuccinic synthetase and lyase deficiency, are currently detected by newborn screening. We used newborn screening data on over 6million births and data from the large US and European longitudinal registries to determine how common these conditions are. The incidence for the United States is predicted to be 1 urea cycle disorder patient for every 35,000 births presenting about 113 new patients per year across all age groups. © 2013.

  16. 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

  17. Nitrogen release, tree uptake, and ecosystem retention in a mid-rotation loblolly pine plantation following fertilization with 15N-enriched enhanced efficiency fertilizers.

    OpenAIRE

    Werner, Amy

    2013-01-01

    Nitrogen is the most frequently limiting nutrient in southern pine plantations.  Previous studies found that only 10 to 25% of applied urea fertilizer N is taken up by trees.  Enhanced efficiency fertilizers could increase tree uptake efficiency by controlling the release of N and/or stabilize N.  Three enhanced efficiency fertilizers were selected as a representation of fertilizers that could be used in forestry: 1) NBPT treated urea (NBPT urea), 2) polymer coated urea (PC urea), and 3) mono...

  18. Development of nitrogen supply strategy for Scenedesmus rubescens attached cultivation toward growth and lipid accumulation.

    Science.gov (United States)

    Cheng, Pengfei; Wang, Yan; Osei-Wusu, David; Wang, Yuanzhu; Liu, Tianzhong

    2018-03-01

    In this study, the microalgae Scenedesmus rubescens were cultivated under the following nitrogen sources, nitrogen concentrations, and nitrogen feeding times (NFTs). This was to help assess biomass and lipid productivity. Scenedesmus rubescens can grow well by adhering to the cellulose acetate membrane in five kinds of nitrogen medium: KNO 3 , urea, NaNO 3 , (NH 4 ) 2 CO 3 , and NH 4 NO 3 . Under the criteria of bio-productivity and lipid productivity, urea was the optimal nitrogen source. Among different urea concentrates, biomass productivity and lipid content of S. rubescens cultivated in 0.27 g/L urea medium were optimized at 8.8 g/(m 2  day) and 31.1%, respectively. With attached cultivation, the highest biomass of 9.4 g/m 2 was obtained at NFTs of 4 days. These results showed that culturing S. rubescens using urea as sole nitrogen source by improving nitrogen uptake with attached cultivation is more efficient.

  19. Effects of different irrigation regimes on fruit production, oil quality, water use efficiency and agronomic nitrogen use efficiency of pumpkin

    Directory of Open Access Journals (Sweden)

    Javad Hamzei

    2016-05-01

    Full Text Available Effect of different irrigation regimes and nitrogen fertilizer on percentage of grain fatty acids, yield, water and nitrogen use efficiency of pumpkin was studies as split plot based on complete randomized block design with three replications in growing season of 2013. Irrigation treatments (320, 420, 600 and 900 mm ha-1 were se as main plots and nitrogen fertilizer (0, 130, 260, 390 and 520 kg urea ha-1 were allocated in subplots. The effect of irrigation and nitrogen on all traits was significant. Also, interaction of irrigation × nitrogen had significant effect on all traits except WUE and NUE. The Highest values of linoleic fatty acid (33.99%, fruit yield (4.40 kg m-2, grain yield (1.53 kg m-2 and agronomic nitrogen use efficiency (32.27 kg fruit/kg urea were achieved at consumption of 600 mm water ha-1 and application of 390 kg urea ha-1. The highest water use efficiency for fruit and grain yield; 56.61 and 1.10 kg mm-1, were revealed at 600 mm irrigation water ha-1. Between nitrogen levels, maximum and minimum WUE for fruit and grain yield were achieved at 390 kg urea and non application of urea treatments, respectively. Also, maximum agronomic nitrogen efficiency belonged to 390 kg urea and minimum this trait with 33 reductions was revealed at 520 kg urea. Based on the results of this research and with considering of water and nitrogen use efficiency, irrigation of pumpkin plants with 600 mm water ha-1 and consumption of 390 kg urea ha-1 was identified as a suitable treatment.

  20. Automated monosegmented flow analyser. Determination of glucose, creatinine and urea.

    Science.gov (United States)

    Raimundo Júnior, I M; Pasquini, C

    1997-10-01

    An automated monosegmented flow analyser containing a sampling valve and a reagent addition module and employing a laboratory-made photodiode array spectrophotometer as detection system is described. The instrument was controlled by a 386SX IBM compatible microcomputer through an IC8255 parallel port that communicates with the interface which controls the sampling valve and reagent addition module. The spectrophotometer was controlled by the same microcomputer through an RS232 serial standard interface. The software for the instrument was written in QuickBasic 4.5. Opto-switches were employed to detect the air bubbles limiting the monosegment, allowing precise sample localisation for reagent addition and signal reading. The main characteristics of the analyser are low reagent consumption and high sensitivity which is independent of the sample volume. The instrument was designed to determine glucose, creatinine or urea in blood plasma and serum without hardware modification. The results were compared against those obtained by the Clinical Hospital of UNICAMP using commercial analysers. Correlation coefficients among the methods were 0.997, 0.982 and 0.996 for glucose, creatinine and urea, respectively.

  1. Construction of ferrocene modified conducting polymer based amperometric urea biosensor.

    Science.gov (United States)

    Dervisevic, Muamer; Dervisevic, Esma; Senel, Mehmet; Cevik, Emre; Yildiz, Huseyin Bekir; Camurlu, Pınar

    2017-07-01

    Herein, an electrochemical urea sensing bio-electrode is reported that has been constructed by firstly electropolymerizing 4-(2,5-Di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline monomer (SNS-Aniline) on Pencil Graphite Electrode (PGE), then modifying the polymer coated electrode surface with di-amino-Ferrocene (DAFc) as the mediator, and lastly Urease enzyme through glutaraldehyde crosslinking. The effect of pH, temperature, polymer thickness, and applied potential on the electrode current response was investigated besides performing storage and operational stability experiments with the interference studies. The resulting urea biosensor's amperometric response was linear in the range of 0.1-8.5mM with the sensitivity of 0.54μA/mM, detection limit of 12μM, and short response time of 2s. The designed bio-electrode was tested with real human blood and urine samples where it showed excellent analytical performance with insignificant interference. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. PLATELET ADHESION TO POLYURETHANE UREA UNDER PULSATILE FLOW CONDITIONS

    Science.gov (United States)

    Navitsky, Michael A.; Taylor, Joshua O.; Smith, Alexander B.; Slattery, Margaret J.; Deutsch, Steven; Siedlecki, Christopher A.; Manning, Keefe B.

    2014-01-01

    Platelet adhesion to a polyurethane urea surface is a precursor to thrombus formation within blood-contacting cardiovascular devices, and platelets have been found to adhere strongly to polyurethane surfaces below a shear rate of approximately 500 s−1. The aim of the current work is to determine platelet adhesion properties to the polyurethane urea surface as a function of time varying shear exposure. A rotating disk system is used to study the influence of steady and pulsatile flow conditions (e.g. cardiac inflow and sawtooth waveforms) for platelet adhesion to the biomaterial surface. All experiments retain the same root mean square angular rotation velocity (29.63 rad/s) and waveform period. The disk is rotated in platelet rich bovine plasma for two hours with adhesion quantified by confocal microscopy measurements of immunofluorescently labeled bovine platelets. Platelet adhesion under pulsating flow is found to exponentially decay with increasing shear rate. Adhesion levels are found to depend upon peak platelet flux and shear rate regardless of rotational waveform. In combination with flow measurements, these results may be useful for predicting regions susceptible to thrombus formation within ventricular assist devices. PMID:24721222

  3. [Influence of a new phosphoramide urease inhibitor on urea-N transformation in different texture soil].

    Science.gov (United States)

    Zhou, Xuan; Wu, Liang Huan; Dai, Feng

    2016-12-01

    Addition of urease inhibitors is one of the important measures to increase nitrogen (N) use efficiency of crop, due to retardant of urea hydrolysis and reduction of ammonia volatilization loss. An incubation experiment was conducted to investigate the urease inhibition effect of a new phosphoramide urease inhibitor, NPPT (N-(n-propyl) thiophosphoric triamide) in different texture soils under dark condition at 25 ℃, and NBPT (N-(n-butyl) thiophosphoric triamide) was obtained to compare the inhibition effect on urease in different soil textures by different dosages of urea adding. Results showed that the effective reaction time of urea was less than 9 d in the loamy and clay soil. Addition of inhibitors for retardation of urea hydrolysis was more than 3 d. In sandy soil, urea decomposition was relatively slow, and adding inhibitor significantly inhibited soil urease acti-vity, and reduced NH 4 + -N content. During the incubation time, the inhibition effect of high dosage urea in the soil was better than that of low dosage. At day 6, the urease inhibition rate of NBPT and NPPT (N 250 mg·kg -1 ) were 56.3% and 53.0% in sandy soil, 0.04% and 0.3% in loamy soil, 4.1% and 6.2% in clay soil; the urease inhibition rate of NBPT and NPPT (N 500 mg·kg -1 ) were 59.4% and 65.8% in sandy soil, 14.5% and 15.1% in loamy soil, 49.1% and 48.1% in clay soil. The urease inhibition effects in different texture soil were in order of sandy soil > clay soil> loamy soil. The soil NH 4 + -N content by different inhibitors during incubation time increased at first and then decreased, while soil NO 3 - -N content and apparent nitrification rate both showed rising trends. Compared with urea treatment, addition of urease inhibitors (NBPT and NPPT) significantly increased urea-N left in the soil and reduced NH 4 + -N content. In short, new urease inhibitor NPPT in different texture is an effective urease inhibitor.

  4. Urea-formaldehyde resins: production, application, and testing

    Science.gov (United States)

    Nuryawan, A.; Risnasari, I.; Sucipto, T.; Heri Iswanto, A.; Rosmala Dewi, R.

    2017-07-01

    Urea-formaldehyde (UF) resin, one of the most important formaldehyde resin adhesives, is a polymeric condensation product of formaldehyde with urea, and being widely used for the manufacture of wood-based composite panels, such as plywood, particleboard, and fiberboard. In spite of its benefits such as fast curing, good performance in the panels (colorless), and lower cost; formaldehyde emission (FE) originated from either UF resin itself or composite products bonded by UF resins is considered a critical drawback as it affects human health particularly in indoor environment. In order to reduce the FE, lowering formaldehyde/urea (F/U) mole ratio in the synthesis of the UF resin was done. In this study, synthesis of UF resins was carried out following the conventional alkaline-acid two-step reaction with a second addition of urea, resulting in F/U mole ratio around 1.0, namely 0.95; 1.05, and 1.15. The UF resins produced were used as binder for particleboard making. The board was manufactured in the laboratory using shaving type particle of Gmelina wood, 8% UF resin based on oven dry particle, and 1% NH4Cl (20%wt) as hardener for the resin. The target of the thickness was 10 mm and the dimension was 25 cm x 25 cm. The resulted particleboard then was evaluated the physical and the mechanical properties by Japanese Industrial Standard (JIS) A 5908 (2003). Further, the resulted particleboard also was used for the mice cage’s wall in order to mimic the real living environment. After four weeks exposure in the cages, the mice then were evaluated their mucous organs as well as their blood. The experiment results were as follows: 1) It was possible to synthesis UF resins with low F/U mole ratio; 2) However, the particleboard bonded UF resins with low F/U mole ratio showed poor properties, particularly on the thickness swelling and modulus of elasticity; 3) There was no significant differences among the mucous organs of the mice after a month exposure FE originated from

  5. Penambahan Urea atau DL-Metionina ke dalam Ransum Komplit Biomassa Ubi Jalar pada Kelinci

    Directory of Open Access Journals (Sweden)

    L. Khotijah

    2006-08-01

    Full Text Available Twenty male cross-breed weanling rabbits were used to study the effect of urea or DL-methionine addition in sweet potatoes biomass complete diets. Completely randomized design was used in this experiment with four treatments and five replications. The treatments consisted of A (comercial diet; B (sweet potatoes biomass diet; BU (B + 0.5% urea and BM (B + 0.5% DL-methionine. The dry matter intake, average daily gain (AVG, feed conversion ratio, dry matter and protein digestibility and nitrogen retention were measured in this experiment. The result showed that the treatments did not significantly affect dry matter intake and feed conversion ratio, digestibility of dry matter and protein, but supplementation of DL-methionine significantly affected average daily gain and nitrogen retention (P<0.05. It was concluded that urea or DL-methionine supplementation in sweet potatoes biomass diets could support good performance of rabbits and it could be used as an alternative source of feed for rabbits.

  6. Urinary phenylacetylglutamine as dosing biomarker for patients with urea cycle disorders.

    Science.gov (United States)

    Mokhtarani, M; Diaz, G A; Rhead, W; Lichter-Konecki, U; Bartley, J; Feigenbaum, A; Longo, N; Berquist, W; Berry, S A; Gallagher, R; Bartholomew, D; Harding, C O; Korson, M S; McCandless, S E; Smith, W; Vockley, J; Bart, S; Kronn, D; Zori, R; Cederbaum, S; Dorrani, N; Merritt, J L; Sreenath-Nagamani, Sandesh; Summar, M; Lemons, C; Dickinson, K; Coakley, D F; Moors, T L; Lee, B; Scharschmidt, B F

    2012-11-01

    We have analyzed pharmacokinetic data for glycerol phenylbutyrate (also GT4P or HPN-100) and sodium phenylbutyrate with respect to possible dosing biomarkers in patients with urea cycle disorders (UCD). These analyses are based on over 3000 urine and plasma data points from 54 adult and 11 pediatric UCD patients (ages 6-17) who participated in three clinical studies comparing ammonia control and pharmacokinetics during steady state treatment with glycerol phenylbutyrate or sodium phenylbutyrate. All patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate or sodium phenylbutyrate in a cross over fashion and underwent 24-hour blood samples and urine sampling for phenylbutyric acid, phenylacetic acid and phenylacetylglutamine. Patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate ranging from 1.5 to 31.8 g/day and of sodium phenylbutyrate ranging from 1.3 to 31.7 g/day. Plasma metabolite levels varied widely, with average fluctuation indices ranging from 1979% to 5690% for phenylbutyric acid, 843% to 3931% for phenylacetic acid, and 881% to 1434% for phenylacetylglutamine. Mean percent recovery of phenylbutyric acid as urinary phenylacetylglutamine was 66.4 and 69.0 for pediatric patients and 68.7 and 71.4 for adult patients on glycerol phenylbutyrate and sodium phenylbutyrate, respectively. The correlation with dose was strongest for urinary phenylacetylglutamine excretion, either as morning spot urine (r = 0.730, p phenylbutyric acid AUC(24-hour). Plasma phenylacetic acid levels in adult and pediatric patients did not show a consistent relationship with either urinary phenylacetylglutamine or ammonia control. The findings are collectively consistent with substantial yet variable pre-systemic (1st pass) conversion of phenylbutyric acid to phenylacetic acid and/or phenylacetylglutamine. The variability of blood metabolite levels during the day, their weaker correlation with dose, the need for multiple blood samples

  7. 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

  8. Disorders of urea cycle: case report

    Directory of Open Access Journals (Sweden)

    Adolfo Álvarez

    2017-08-01

    Discussion: Urea cycle disorders are part of innate errors in ammonia detoxification or arginine synthesis, secondary to defects in the enzymes involved in this cycle. Clinical manifestations are secondary to elevated levels of serum ammonia. The treatment is composed of an acute and chronic phase.

  9. Effect of the urease inhibitor phosphoric acid phenyl ester diamide on the utilization of urea-N in top dressing of spring wheat and oats

    Energy Technology Data Exchange (ETDEWEB)

    Matzel, W; Mueller, S; Lippold, H; Heber, R [Akademie der Landwirtschaftswissenschaften der DDR, Leipzig-Potsdam. Inst. fuer Duengungsforschung

    1979-01-01

    In pot experiments with spring wheat and oats the application of the urease inhibitor phosphoric acid phenyl ester diamide (PPDA) in addition to top dressing with /sup 15/N-urea revealed a 10% better utilization of the /sup 15/N-urea by the plant (related to the N amount applied). The loss-reducing effect of PPDA was especially felt when there were favourable conditions for NH/sub 3/ volatilization such as rapid hydrolysis of urea on the wet surface of light soil during shooting of the wheat. PPDA did not have any adverse influence on the course of the nitrogen uptake by the cereals during the time of shooting from the urea applied in top dressing. The utilization of the urea-N by the wheat, being about 5 to 6% lower in comparison to ammonium nitrate, under conditions that do not allow NH/sub 3/ losses, is to be attributed to the increased immobilization of the urea-N in the soil. The processes responsible for the nitrogen losses were concluded 3 to 4 weeks after top dressing to the cereals during the shooting period.

  10. Effect of the urease inhibitor phosphoric acid phenyl ester diamide on the utilization of urea-N in top dressing of spring wheat and oats

    International Nuclear Information System (INIS)

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

    1979-01-01

    In pot experiments with spring wheat and oats the application of the urease inhibitor phosphoric acid phenyl ester diamide (PPDA) in addition to top dressing with 15 N-urea revealed a 10% better utilization of the 15 N-urea by the plant (related to the N amount applied). The loss-reducing effect of PPDA was especially felt when there were favourable conditions for NH 3 volatilization such as rapid hydrolysis of urea on the wet surface of light soil during shooting of the wheat. PPDA did not have any adverse influence on the course of the nitrogen uptake by the cereals during the time of shooting from the urea applied in top dressing. The utilization of the urea-N by the wheat, being about 5 to 6% lower in comparison to ammonium nitrate, under conditions that do not allow NH 3 losses, is to be attributed to the increased immobilization of the urea-N in the soil. The processes responsible for the nitrogen losses were concluded 3 to 4 weeks after top dressing to the cereals during the shooting period. (author)

  11. Light exposure enhances urea absorption in the fluted giant clam, Tridacna squamosa, and up-regulates the protein abundance of a light-dependent urea active transporter, DUR3-like, in its ctenidium.

    Science.gov (United States)

    Chan, Christabel Y L; Hiong, Kum C; Boo, Mel V; Choo, Celine Y L; Wong, Wai P; Chew, Shit F; Ip, Yuen K

    2018-04-19

    Giant clams live in nutrient-poor reef waters of the Indo-Pacific and rely on symbiotic dinoflagellates ( Symbiodinium spp., also known as zooxanthellae) for nutrients. As the symbionts are nitrogen deficient, the host clam has to absorb exogenous nitrogen and supply it to them. This study aimed to demonstrate light-enhanced urea absorption in the fluted giant clam, Tridacna squamosa , and to clone and characterize the urea active transporter DUR3-like from its ctenidium (gill). The results indicate that T. squamosa absorbs exogenous urea, and the rate of urea uptake in the light was significantly higher than that in darkness. The DUR3-like coding sequence obtained from its ctenidium comprised 2346 bp, encoding a protein of 782 amino acids and 87.0 kDa. DUR3-like was expressed strongly in the ctenidium, outer mantle and kidney. Twelve hours of exposure to light had no significant effect on the transcript level of ctenidial DUR3-like However, between 3 and 12 h of light exposure, DUR3-like protein abundance increased progressively in the ctenidium, and became significantly greater than that in the control at 12 h. DUR3-like had an apical localization in the epithelia of the ctenidial filaments and tertiary water channels. Taken together, these results indicate that DUR3-like might participate in light-enhanced urea absorption in the ctenidium of T. squamosa When made available to the symbiotic zooxanthellae that are known to possess urease, the absorbed urea can be metabolized to NH 3 and CO 2 to support amino acid synthesis and photosynthesis, respectively, during insolation. © 2018. Published by The Company of Biologists Ltd.

  12. Determination of urea 13C in urea 13C mixed powder by HPLC

    International Nuclear Information System (INIS)

    Zhong Jianguo; Song Tianqi

    2006-01-01

    A HPLC method is developed for determination of Urea 13 C in Urea 13 C Mixed Powder. A Alltech Econosphere NH2 column (250 mm x 4.6 mm, 5 μm)is used as stationary phrase, a mixture of V(acetonitrile): V(methanol): V(water) = 900 : 100: 10 is used as mobile phase and the flow rate is l mL·min -1 , UV detection wavelength is performed at 200 nm. The calibration curve shows good linearity in the range of 0.2-1.0 g·L -1 of Urea 13 C, y=2.548 x 10 6 x + 4.005 x 10 4 , r=0.9999, and the averaged recovery is 100.6%. The method is simple and accurate, and can be used for the quality control of Urea 13C