Radiation Chemistry in Ammonia-Water Ices

NASA Technical Reports Server (NTRS)

Loeffler, M. J.; Raut, U.; Baragiola, R. A.

2010-01-01

We studied the effects of 100 keV proton irradiation on films of ammonia-water mixtures between 20 and 120 K. Irradiation destroys ammonia, leading to the formation and trapping of H2, N2 NO, and N2O, the formation of cavities containing radiolytic gases, and ejection of molecules by sputtering. Using infrared spectroscopy, we show that at all temperatures the destruction of ammonia is substantial, but at higher temperatures (120 K), it is nearly complete (approximately 97% destroyed) after a fluence of 10(exp 16) ions per square centimeter. Using mass spectroscopy and microbalance gravimetry, we measure the sputtering yield of our sample and the main components of the sputtered flux. We find that the sputtering yield depends on fluence. At low temperatures, the yield is very low initially and increases quadratically with fluence, while at 120 K the yield is constant and higher initially. The increase in the sputtering yield with fluence is explained by the formation and trapping of the ammonia decay products, N2 and H2 which are seen to be ejected from the ice at all temperatures.

Reproducibility and Accuracy of Quantitative Myocardial Blood Flow Using 82Rb-PET: Comparison with 13N-Ammonia

PubMed Central

Fakhri, Georges El

2011-01-01

82Rb cardiac PET allows the assessment of myocardial perfusion using a column generator in clinics that lack a cyclotron. We and others have previously shown that quantitation of myocardial blood flow (MBF) and coronary flow reserve (CFR) is feasible using dynamic 82Rb PET and factor and compartment analyses. The aim of the present work was to determine the intra- and inter-observer variability of MBF estimation using 82Rb PET as well as the reproducibility of our generalized factor + compartment analyses methodology to estimate MBF and assess its accuracy by comparing, in the same subjects, 82Rb estimates of MBF to those obtained using 13N-ammonia. Methods Twenty-two subjects were included in the reproducibility and twenty subjects in the validation study. Patients were injected with 60±5mCi of 82Rb and imaged dynamically for 6 minutes at rest and during dipyridamole stress Left and right ventricular (LV+RV) time-activity curves were estimated by GFADS and used as input to a 2-compartment kinetic analysis that estimates parametric maps of myocardial tissue extraction (K1) and egress (k2), as well as LV+RV contributions (fv,rv). Results Our results show excellent reproducibility of the quantitative dynamic approach itself with coefficients of repeatability of 1.7% for estimation of MBF at rest, 1.4% for MBF at peak stress and 2.8% for CFR estimation. The inter-observer reproducibility between the four observers that participated in this study was also very good with correlation coefficients greater than 0.87 between any two given observers when estimating coronary flow reserve. The reproducibility of MBF in repeated 82Rb studies was good at rest and excellent at peak stress (r2=0.835). Furthermore, the slope of the correlation line was very close to 1 when estimating stress MBF and CFR in repeated 82Rb studies. The correlation between myocardial flow estimates obtained at rest and during peak stress in 82Rb and 13N-ammonia studies was very good at rest (r2

Ammonia 15N/14N Isotope Ratio in the Jovian Atmosphere

NASA Technical Reports Server (NTRS)

Mahaffy, P.R.; Niemann, H. B.; Atreya, S. K.; Wong, M. H.; Owen, T. C; Einaudi, Franco (Technical Monitor)

2000-01-01

Data from the Galileo Probe Mass Spectrometer has been used to derive the N-15/N-14 isotope ratio in ammonia at Jupiter. Although the mass spectral interference from the water contribution to 18 amu makes an accurate derivation of the (N-15)H3/(N-14)H3 ratio difficult from measurements of the singly ionized signals at 18 and 17 amu, this interference is not present in the doubly charged 8.5 and 9.0 amu signals from (N-14)H3++ and (N-15)H3++ respectively. Although the count rate from the 9 amu signal is low during the direct sampling of the atmosphere, the ammonia signal was considerably enhanced during the first enrichment cell (EC1) experiment that measured gas sampled between 0.8 and 2.8 bar. Count rates at 9 amu in the EC1 experiment reach 60/second and measure ammonia sampled from 0.88 to 2.8 bar. In the EC1 measurements the 8.5 amu signal is not measured directly, but can be calculated from the ammonia contribution to 17 amu and the ratio of NH3 ions of a double to single charged observed during a high resolution mass scan taken near the end of the descent. The high resolution scan gives this ratio from ammonia sampled much deeper in the atmosphere. These results are described and compared with Infrared Space Observatory-Short Wavelength Spectrometer (ISO-SWS) observations that give this ratio at 400 mbar.

Ammonia-oxidizing archaea have more important role than ammonia-oxidizing bacteria in ammonia oxidation of strongly acidic soils

PubMed Central

Zhang, Li-Mei; Hu, Hang-Wei; Shen, Ju-Pei; He, Ji-Zheng

2012-01-01

Increasing evidence demonstrated the involvement of ammonia-oxidizing archaea (AOA) in the global nitrogen cycle, but the relative contributions of AOA and ammonia-oxidizing bacteria (AOB) to ammonia oxidation are still in debate. Previous studies suggest that AOA would be more adapted to ammonia-limited oligotrophic conditions, which seems to be favored by protonation of ammonia, turning into ammonium in low-pH environments. Here, we investigated the autotrophic nitrification activity of AOA and AOB in five strongly acidic soils (pH<4.50) during microcosm incubation for 30 days. Significantly positive correlations between nitrate concentration and amoA gene abundance of AOA, but not of AOB, were observed during the active nitrification. 13CO2-DNA-stable isotope probing results showed significant assimilation of 13C-labeled carbon source into the amoA gene of AOA, but not of AOB, in one of the selected soil samples. High levels of thaumarchaeal amoA gene abundance were observed during the active nitrification, coupled with increasing intensity of two denaturing gradient gel electrophoresis bands for specific thaumarchaeal community. Addition of the nitrification inhibitor dicyandiamide (DCD) completely inhibited the nitrification activity and CO2 fixation by AOA, accompanied by decreasing thaumarchaeal amoA gene abundance. Bacterial amoA gene abundance decreased in all microcosms irrespective of DCD addition, and mostly showed no correlation with nitrate concentrations. Phylogenetic analysis of thaumarchaeal amoA gene and 16S rRNA gene revealed active 13CO2-labeled AOA belonged to groups 1.1a-associated and 1.1b. Taken together, these results provided strong evidence that AOA have a more important role than AOB in autotrophic ammonia oxidation in strongly acidic soils. PMID:22134644

Autotrophic ammonia oxidation by soil thaumarchaea.

PubMed

Zhang, Li-Mei; Offre, Pierre R; He, Ji-Zheng; Verhamme, Daniel T; Nicol, Graeme W; Prosser, James I

2010-10-05

Nitrification plays a central role in the global nitrogen cycle and is responsible for significant losses of nitrogen fertilizer, atmospheric pollution by the greenhouse gas nitrous oxide, and nitrate pollution of groundwaters. Ammonia oxidation, the first step in nitrification, was thought to be performed by autotrophic bacteria until the recent discovery of archaeal ammonia oxidizers. Autotrophic archaeal ammonia oxidizers have been cultivated from marine and thermal spring environments, but the relative importance of bacteria and archaea in soil nitrification is unclear and it is believed that soil archaeal ammonia oxidizers may use organic carbon, rather than growing autotrophically. In this soil microcosm study, stable isotope probing was used to demonstrate incorporation of (13)C-enriched carbon dioxide into the genomes of thaumarchaea possessing two functional genes: amoA, encoding a subunit of ammonia monooxygenase that catalyses the first step in ammonia oxidation; and hcd, a key gene in the autotrophic 3-hydroxypropionate/4-hydroxybutyrate cycle, which has been found so far only in archaea. Nitrification was accompanied by increases in archaeal amoA gene abundance and changes in amoA gene diversity, but no change was observed in bacterial amoA genes. Archaeal, but not bacterial, amoA genes were also detected in (13)C-labeled DNA, demonstrating inorganic CO(2) fixation by archaeal, but not bacterial, ammonia oxidizers. Autotrophic archaeal ammonia oxidation was further supported by coordinate increases in amoA and hcd gene abundance in (13)C-labeled DNA. The results therefore provide direct evidence for a role for archaea in soil ammonia oxidation and demonstrate autotrophic growth of ammonia oxidizing archaea in soil.

Absolute quantification of myocardial blood flow with 13N-ammonia and 3-dimensional PET.

PubMed

Schepis, Tiziano; Gaemperli, Oliver; Treyer, Valerie; Valenta, Ines; Burger, Cyrill; Koepfli, Pascal; Namdar, Mehdi; Adachi, Itaru; Alkadhi, Hatem; Kaufmann, Philipp A

2007-11-01

The aim of this study was to compare 2-dimensional (2D) and 3-dimensional (3D) dynamic PET for the absolute quantification of myocardial blood flow (MBF) with (13)N-ammonia ((13)N-NH(3)). 2D and 3D MBF measurements were collected from 21 patients undergoing cardiac evaluation at rest (n = 14) and during standard adenosine stress (n = 7). A lutetium yttrium oxyorthosilicate-based PET/CT system with retractable septa, enabling the sequential acquisition of 2D and 3D images within the same patient and study, was used. All 2D studies were performed by injecting 700-900 MBq of (13)N-NH(3). For 14 patients, 3D studies were performed with the same injected (13)N-NH(3) dose as that used in 2D studies. For the remaining 7 patients, 3D images were acquired with a lower dose of (13)N-NH(3), that is, 500 MBq. 2D images reconstructed by use of filtered backprojection (FBP) provided the reference standard for MBF measurements. 3D images were reconstructed by use of Fourier rebinning (FORE) with FBP (FORE-FBP), FORE with ordered-subsets expectation maximization (FORE-OSEM), and a reprojection algorithm (RP). Global MBF measurements derived from 3D PET with FORE-FBP (r = 0.97), FORE-OSEM (r = 0.97), and RP (r = 0.97) were well correlated with those derived from 2D FBP (all Ps < 0.0001). The mean +/- SD differences in global MBF measurements between 3D FORE-FBP and 2D FBP and between 3D FORE-OSEM and 2D FBP were 0.01 +/- 0.14 and 0.01 +/- 0.15 mL/min/g, respectively. The mean +/- SD difference in global MBF measurements between 3D RP and 2D FBP was 0.00 +/- 0.16 mL/min/g. The best correlation between 2D PET and 3D PET performed with the lower injected activity was found for the 3D FORE-FBP reconstruction algorithm (r = 0.95, P < 0.001). For this scanner type, quantitative measurements of MBF with 3D PET and (13)N-NH(3) were in excellent agreement with those obtained with the 2D technique, even when a lower activity was injected.

Formation of glutamine from (/sup 13/N)ammonia, (/sup 13/N)dinitrogen, and (/sup 14/C)glutamate by heterocysts isolated from Anabaena cylindrica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, J.; Meeks, J.C.; Wolk, C.P.

A method is described for the isolation of metabolically active heterocysts from Anabaena cylindrica. These isolated heterocysts accounted for up to 34% of the acetylene-reducing activity of whole filaments and had a specific activity of up to 1,560 nmol of C/sub 2/H/sub 4/ formed per mg of heterocyst chlorophyll per min. Activity of glutamine synthetase was coupled to activity of nitrogenase in isolated heterocysts as shown by acetylene-inhibitable formation of (/sup 13/N)NH/sub 3/ and of amide-labeled (/sup 13/N)glutamine from (/sup 13/N)N/sub 2/. A method is also described for the production of 6-mCi amounts of (/sup 13/N)NH/sub 3/. Isolated heterocysts formedmore » (/sup 13/N)glutamine from (/sup 13/N)NH/sub 3/ and glutamate, and (/sup 14/C)glutamine from NH/sub 3/ and (/sup 14/C)glutamate, in the presence of magnesium adenosine 5'-triphosphate. Methionine sulfoximine strongly inhibited these syntheses. Glutamate synthase is, after nitrogenase and glutamine synthetase, the third sequential enzyme involved in the assimilation of N/sub 2/ by intact filaments. However, the kinetics of solubilization of the activity of glutamate synthase during cavitation of suspensions of A. cylindrica indicated that very little, if any, of the activity of that enzyme was located in heterocysts. Concordantly, isolated heterocysts failed to form substantial amounts of radioactive glutamate from either (/sup 13/N)glutamine or ..cap alpha..-(/sup 14/C)ketoglutarate in the presence of other substrates and cofactors of the glutamate synthase reaction. However, they formed (/sup 14/C)glutamate rapidly from ..cap alpha..-(/sup 14/C)ketoglutarate by aminotransferase reactions, with various amino acids as the nitrogen donor. The implications of these findings with regard to the identities of the substances moving between heterocysts and vegetative cells are discussed.« less

Evaluation of autotrophic growth of ammonia-oxidizers associated with granular activated carbon used for drinking water purification by DNA-stable isotope probing.

PubMed

Niu, Jia; Kasuga, Ikuro; Kurisu, Futoshi; Furumai, Hiroaki; Shigeeda, Takaaki

2013-12-01

Nitrification is an important biological function of granular activated carbon (GAC) used in advanced drinking water purification processes. Newly discovered ammonia-oxidizing archaea (AOA) have challenged the traditional understanding of ammonia oxidation, which considered ammonia-oxidizing bacteria (AOB) as the sole ammonia-oxidizers. Previous studies demonstrated the predominance of AOA on GAC, but the contributions of AOA and AOB to ammonia oxidation remain unclear. In the present study, DNA-stable isotope probing (DNA-SIP) was used to investigate the autotrophic growth of AOA and AOB associated with GAC at two different ammonium concentrations (0.14 mg N/L and 1.4 mg N/L). GAC samples collected from three full-scale drinking water purification plants in Tokyo, Japan, had different abundance of AOA and AOB. These samples were fed continuously with ammonium and (13)C-bicarbonate for 14 days. The DNA-SIP analysis demonstrated that only AOA assimilated (13)C-bicarbonate at low ammonium concentration, whereas AOA and AOB exhibited autotrophic growth at high ammonium concentration. This indicates that a lower ammonium concentration is preferable for AOA growth. Since AOA could not grow without ammonium, their autotrophic growth was coupled with ammonia oxidation. Overall, our results point towards an important role of AOA in nitrification in GAC filters treating low concentration of ammonium. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effects of isotope-labeled analogs on the LC-IDMS measurement by comparison of ESI responses and matrix effect of melamine, 13C3-melamine, 13C3+15N3-melamine, and 15N3-melamine.

PubMed

Li, Xiu Qin; Zhang, Qing He; Yang, Zong; Li, Hong Mei; Huang, Dong Feng

2017-05-01

In this paper, the effect of isotope-labeled analogs on the liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) measurement was evaluated based on the comparison research of electrospray ionization responses (ESI) and matrix effect of melamine, 13 C 3 -melamine, 13 C 3 + 15 N 3 -melamine, and 15 N 3 -melamine. The isotope-labeled melamines had similar ionization efficiency with melamine in the electrospray ionization source, but the intensity of corresponding quantitative fragment ions had distinctive differences. Based on the density functional theory at the B3LYP/6-311+G** level, this phenomenon was explained very well. The rare cleavage pathways of melamine, which just could be exactly identified by 15 N-labeled melamines, resulted in the difference of quantitative fragment ions between 15 N-labeled melamines and melamine. The interaction of ESI response between melamine and isotope-labeled melamines was investigated using MRM monitor mode. 15 N-labeled melamine had significant ion inter-suppression effect on melamine, while 13 C-labeled melamine had little influence on melamine. Finally, the influence of different isotope-labeled melamines on the LC-IDMS result was evaluated using the IDMS correction factor (θ). Taking the determination of melamine in milk powder as an example, the matrix effects of different isotope-labeled melamines and melamine had notable difference and the impact of this difference on the measurement results depended on the concentrations of analyte and matrix solution. It was worth noting that 15 N 3 -melamine exhibited significant ion suppression to melamine in matrix solution. The deviation of the results from IDMS method might reach 59% using 15 N 3 -melamine as internal standard in special matrix solution. Graphical Abstract The comparison of ESI responses of melamine, 13 C 3 -melamine, 13 C 3 + 15 N 3 -melamine and 15 N 3 -melamine.

Acidification Enhances Hybrid N2O Production Associated with Aquatic Ammonia-Oxidizing Microorganisms

PubMed Central

Frame, Caitlin H.; Lau, Evan; Nolan, E. Joseph; Goepfert, Tyler J.; Lehmann, Moritz F.

2017-01-01

Ammonia-oxidizing microorganisms are an important source of the greenhouse gas nitrous oxide (N2O) in aquatic environments. Identifying the impact of pH on N2O production by ammonia oxidizers is key to understanding how aquatic greenhouse gas fluxes will respond to naturally occurring pH changes, as well as acidification driven by anthropogenic CO2. We assessed N2O production rates and formation mechanisms by communities of ammonia-oxidizing bacteria (AOB) and archaea (AOA) in a lake and a marine environment, using incubation-based nitrogen (N) stable isotope tracer methods with 15N-labeled ammonium (15NH4+) and nitrite (15NO2−), and also measurements of the natural abundance N and O isotopic composition of dissolved N2O. N2O production during incubations of water from the shallow hypolimnion of Lake Lugano (Switzerland) was significantly higher when the pH was reduced from 7.54 (untreated pH) to 7.20 (reduced pH), while ammonia oxidation rates were similar between treatments. In all incubations, added NH4+ was the source of most of the N incorporated into N2O, suggesting that the main N2O production pathway involved hydroxylamine (NH2OH) and/or NO2− produced by ammonia oxidation during the incubation period. A small but significant amount of N derived from exogenous/added 15NO2− was also incorporated into N2O, but only during the reduced-pH incubations. Mass spectra of this N2O revealed that NH4+ and 15NO2− each contributed N equally to N2O by a “hybrid-N2O” mechanism consistent with a reaction between NH2OH and NO2−, or compounds derived from these two molecules. Nitrifier denitrification was not an important source of N2O. Isotopomeric N2O analyses in Lake Lugano were consistent with incubation results, as 15N enrichment of the internal N vs. external N atoms produced site preferences (25.0–34.4‰) consistent with NH2OH-dependent hybrid-N2O production. Hybrid-N2O formation was also observed during incubations of seawater from coastal Namibia

Biological Ammonia Removal: From Theory to Case Studies in 20 Minutes

EPA Science Inventory

This presentation documents the results of two pilot-scale treatment studies, in Ohio and Iowa, that investigated the biological removal of ammonia from ground water. Influent ammonia concentrations in the Ohio and Iowa studies averaged 1.3 and 3.3 mg/L - N, respectively. Both ...

16 CFR 305.13 - Labeling for ceiling fans.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CONCERNING DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Required Disclosures § 305.13 Labeling for ceiling fans. (a) Ceiling fans—(1) Content. Any covered product that is a...

16 CFR 305.13 - Labeling for ceiling fans.

Code of Federal Regulations, 2010 CFR

2010-01-01

... CONCERNING DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Required Disclosures § 305.13 Labeling for ceiling fans. (a) Ceiling fans—(1) Content. Any covered product that is a...

16 CFR 305.13 - Labeling for ceiling fans.

Code of Federal Regulations, 2012 CFR

2012-01-01

... CONCERNING DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Required Disclosures § 305.13 Labeling for ceiling fans. (a) Ceiling fans—(1) Content. Any covered product that is a...

16 CFR 305.13 - Labeling for ceiling fans.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CONCERNING DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND OTHER PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Required Disclosures § 305.13 Labeling for ceiling fans. (a) Ceiling fans—(1) Content. Any covered product that is a...

Innovative Biological Water Treatment for the Removal of Elevated Ammonia

EPA Science Inventory

The objective of this work was to demonstrate the effectiveness of an innovative and simple biological water treatment approach for removing 3.3 mg N/L ammonia and iron from water using a pilot study conducted at a utility in Iowa. Biological water treatment can be an effective a...

Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants.

PubMed

Shao, Jiahui; Fang, Xuliang; He, Yiliang; Jin, Qiang

2008-01-01

Abstract Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditional chlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaks in the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose. Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditions on the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration, liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9% was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically found to be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammonia removal rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plant membrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatment plant, also paved the way towards a larger scale application.

Ammonia pollution characteristics of centralized drinking water sources in China.

PubMed

Fu, Qing; Zheng, Binghui; Zhao, Xingru; Wang, Lijing; Liu, Changming

2012-01-01

The characteristics of ammonia in drinking water sources in China were evaluated during 2005-2009. The spatial distribution and seasonal changes of ammonia in different types of drinking water sources of 22 provinces, 5 autonomous regions and 4 municipalities were investigated. The levels of ammonia in drinking water sources follow the order of river > lake/reservoir > groundwater. The levels of ammonia concentration in river sources gradually decreased from 2005 to 2008, while no obvious change was observed in the lakes/reservoirs and groundwater drinking water sources. The proportion of the type of drinking water sources is different in different regions. In river drinking water sources, the ammonia level was varied in different regions and changed seasonally. The highest value and wide range of annual ammonia was found in South East region, while the lowest value was found in Southwest region. In lake/reservoir drinking water sources, the ammonia levels were not varied obviously in different regions. In underground drinking water sources, the ammonia levels were varied obviously in different regions due to the geological permeability and the natural features of regions. In the drinking water sources with higher ammonia levels, there are enterprises and wastewater drainages in the protected areas of the drinking water sources.

Ammonia Observations of NGC 6334 I(N)

NASA Technical Reports Server (NTRS)

Kuiper, T. B. H.; Peters, W. L., III; Foster, J. R.; Gardner, F. F.; Whiteoak, J. B.

1995-01-01

Coincident with the far-infrared source NGC 6334 I(N) and water maser source E is a massive dense cloud which has the most intense ammonia (1, 1) emission of any known interstellar cloud. We have mapped the (3, 3) emission and find the cloud is extended 0.8 pc in the direction parallel to the Galactic plane, and 0.5 pc perpendicular to it. It has a velocity gradient of 1 km/s.pc perpendicular to the Galactic plane. The gas kinetic temperature is about 30 K and the density is greater than 10(exp 6)/cc. The mass of the cloud is about 3000 solar mass, 3 times greater than previously estimated. The para-ammonia column density is 6 - 8 x 10(exp 15)/sq cm. An ammonia abundance of 0.5 - 1.5 x 10(exp -8) is inferred, where the larger number assumes an early time ortho/para ratio. This suggests either a cloud age of less than approximately 10(exp 6) yr, or substantial depletion of ammonia.

Mechanism studies of the conversion of 13C-labeled n-butane on zeolite H-ZSM-5 by using 13C magic angle spinning NMR spectroscopy and GC-MS analysis.

PubMed

Luzgin, Mikhail V; Stepanov, Alexander G; Arzumanov, Sergei S; Rogov, Vladimir A; Parmon, Valentin N; Wang, Wei; Hunger, Michael; Freude, Dieter

2005-12-23

By using 13C MAS NMR spectroscopy (MAS = magic angle spinning), the conversion of selectively 13C-labeled n-butane on zeolite H-ZSM-5 at 430-470 K has been demonstrated to proceed through two pathways: 1) scrambling of the selective 13C-label in the n-butane molecule, and 2) oligomerization-cracking and conjunct polymerization. The latter processes (2) produce isobutane and propane simultaneously with alkyl-substituted cyclopentenyl cations and condensed aromatic compounds. In situ 13C MAS NMR and complementary ex situ GC-MS data provided evidence for a monomolecular mechanism of the 13C-label scrambling, whereas both isobutane and propane are formed through intermolecular pathways. According to 13C MAS NMR kinetic measurements, both pathways proceed with nearly the same activation energies (E(a) = 75 kJ mol(-1) for the scrambling and 71 kJ mol(-1) for isobutane and propane formation). This can be rationalized by considering the intermolecular hydride transfer between a primarily initiated carbenium ion and n-butane as being the rate-determining stage of the n-butane conversion on zeolite H-ZSM-5.

Copper-induced ammonia N-H functionalization.

PubMed

Álvarez, María; Álvarez, Eleuterio; Fructos, Manuel R; Urbano, Juan; Pérez, Pedro J

2016-10-07

The activation of ammonia has been achieved with the aid of the Tp(Ms)Cu core (Tp(Ms) = hydrotris(3-mesityl-pyrazolyl)borate). Complexes of the general composition Tp(Ms)Cu(amine) (1-4) including the ammonia adduct Tp(Ms)Cu(NH3) (1) have been synthesized and fully spectroscopical- and structurally characterized. Coordinated ammonia in 1 has been reacted with Ph3CPF6 yielding Tp(Ms)Cu(NH2CPh3) (5) as a result of N-H cleavage and N-C bond formation. In a parallel manner the catalytic functionalization of ammonia with ethyl diazoacetate leading to glycinate derivatives has been developed with Tp(Ms)Cu(THF) as the catalyst, in the first example of this transformation with ammonia and a copper-based system.

A simple method for N-15 labelling of exocyclic amino groups in synthetic oligodeoxynucleotides

PubMed Central

Acedo, Montse; Fàbrega, Carme; Aviño, Anna; Goodman, Myron; Fagan, Patricia; Wemmer, David; Eritja, Ramon

1994-01-01

The use of the ammonia deprotection step to introduce 15N labels at specific exocyclic amino positions of adenine, cytosine, guanine or 2-aminopurine of oligodeoxynucleotides is described. PMID:8065910

Synthesis of ammonia directly from air and water at ambient temperature and pressure

NASA Astrophysics Data System (ADS)

Lan, Rong; Irvine, John T. S.; Tao, Shanwen

2013-01-01

The N≡N bond (225 kcal mol-1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10-5 mol m-2 s-1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.

Synthesis of ammonia directly from air and water at ambient temperature and pressure

PubMed Central

Lan, Rong; Irvine, John T. S.; Tao, Shanwen

2013-01-01

The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454

The Role of Glutamine Synthetase and Glutamate Dehydrogenase in Cerebral Ammonia Homeostasis

PubMed Central

Cooper, Arthur J. L.

2012-01-01

In the brain, glutamine synthetase (GS), which is located predominantly in astrocytes, is largely responsible for the removal of both blood-derived and metabolically generated ammonia. Thus, studies with [13N]ammonia have shown that about 25% of blood-derived ammonia is removed in a single pass through the rat brain and that this ammonia is incorporated primarily into glutamine (amide) in astrocytes. Major pathways for cerebral ammonia generation include the glutaminase reaction and the glutamate dehydrogenase (GDH) reaction. The equilibrium position of the GDH-catalyzed reaction in vitro favors reductive amination of α-ketoglutarate at pH 7.4. Nevertheless, only a small amount of label derived from [13N]ammonia in rat brain is incorporated into glutamate and the α-amine of glutamine in vivo. Most likely the cerebral GDH reaction is drawn normally in the direction of glutamate oxidation (ammonia production) by rapid removal of ammonia as glutamine. Linkage of glutamate/α-ketoglutarate-utilizing aminotransferases with the GDH reaction channels excess amino acid nitrogen toward ammonia for glutamine synthesis. At high ammonia levels and/or when GS is inhibited the GDH reaction coupled with glutamate/α-ketoglutarate-linked aminotransferases may, however, promote the flow of ammonia nitrogen toward synthesis of amino acids. Preliminary evidence suggests an important role for the purine nucleotide cycle (PNC) as an additional source of ammonia in neurons (Net reaction: L-Aspartate + GTP + H2O → Fumarate + GDP + Pi + NH3) and in the beat cycle of ependyma cilia. The link of the PNC to aminotransferases and GDH/GS and its role in cerebral nitrogen metabolism under both normal and pathological (e.g. hyperammonemic encephalopathy) conditions should be a productive area for future research. PMID:22618691

CHEMICAL PROCESSING OF PURE AMMONIA AND AMMONIA-WATER ICES INDUCED BY HEAVY IONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bordalo, V.; Da Silveira, E. F.; Lv, X. Y.

Cosmic rays are possibly the main agents to prevent the freeze-out of molecules onto grain surfaces in cold dense clouds. Ammonia (NH{sub 3}) is one of the most abundant molecules present in dust ice mantles, with a concentration of up to 15% relative to water (H{sub 2}O). FTIR spectroscopy is used to monitor pure NH{sub 3} and NH{sub 3}-H{sub 2}O ice samples as they are irradiated with Ni and Zn ion beams (500-600 MeV) at GANIL/France. New species, such as hydrazine (N{sub 2}H{sub 4}), diazene (N{sub 2}H{sub 2} isomers), molecular hydrogen (H{sub 2}), and nitrogen (N{sub 2}) were identified aftermore » irradiation of pure NH{sub 3} ices. Nitrous oxide (N{sub 2}O), nitrogen oxide (NO), nitrogen dioxide (NO{sub 2}), and hydroxylamine (NH{sub 2}OH) are some of the products of the NH{sub 3}-H{sub 2}O ice radiolysis. The spectral band at 6.85 {mu}m was observed after irradiation of both types of ice. Besides the likely contribution of ammonium (NH{sub 4}{sup +}) and amino (NH{sub 2}) radicals, data suggest a small contribution of NH{sub 2}OH to this band profile after high fluences of irradiation of NH{sub 3}-H{sub 2}O ices. The spectral shift of the NH{sub 3} ''umbrella'' mode (9.3 {mu}m) band is parameterized as a function of NH{sub 3}/H{sub 2}O ratio in amorphous ices. Ammonia and water destruction cross-sections are obtained, as well as the rate of NH{sub 3}-H{sub 2}O (1:10) ice compaction, measured by the OH dangling bond destruction cross-section. Ammonia destruction is enhanced in the presence of H{sub 2}O in the ice and a power law relationship between stopping power and NH{sub 3} destruction cross-section is verified. Such results may provide relevant information for the evolution of molecular species in dense molecular clouds.« less

Seasonal ammonia losses from spray-irrigation with secondary-treated recycled water.

PubMed

Saez, Jose A; Harmon, Thomas C; Doshi, Sarika; Guerrero, Francisco

2012-01-01

This work examines ammonia volatilization associated with agricultural irrigation employing recycled water. Effluent from a secondary wastewater treatment plant was applied using a center pivot irrigation system on a 12 ha agricultural site in Palmdale, California. Irrigation water was captured in shallow pans and ammonia concentrations were quantified in four seasonal events. The average ammonia loss ranged from 15 to 35% (averaging 22%) over 2-h periods. Temporal mass losses were well-fit using a first-order model. The resulting rate constants correlated primarily with temperature and secondarily with wind speed. The observed application rates and timing were projected over an entire irrigation season using meteorological time series data from the site, which yielded volatilization estimates of 0.03 to 0.09 metric tons NH(3)-N/ha per year. These rates are consistent with average rates (0.04 to 0.08 MT NH(3)-N/ha per year) based on 10 to 20 mg NH(3)-N/L effluent concentrations and a 22% average removal. As less than 10% of the treated effluent in California is currently reused, there is potential for this source to increase, but the increase may be offset by a corresponding reduction in synthetic fertilizers usage. This point is a factor for consideration with respect to nutrient management using recycled water.

Supercritical fluid extraction of 11C-labeled metabolites in tissue using supercritical ammonia.

PubMed

Jacobson, G B; Moulder, R; Lu, L; Bergström, M; Markides, K E; Långström, B

1997-02-01

Supercritical fluid extraction (SFE) of 11C-labeled tracer compounds and their metabolites from biological tissue was performed using supercritical ammonia in an attempt to develop a rapid extraction procedure that allowed subsequent analysis of the labeled metabolites. Metabolites were extracted from kidneys and brain in rats given in vivo injections of the radiotracers O-[2-11C]acetyl-L-carnitine and N-[11C]methylpiperidyl benzilate, respectively. Only a minimal sample pretreatment of the tissue was necessary, i.e., cutting into 10-20 pieces and mixing with the drying agent Hydromatrix, before it was loaded into the extraction vessel. Extraction efficiency was measured for SFE at temperatures over the range of 70-150 degrees C and a pressure of 400 bar. For O-[2-11C]acetyl-L-carnitine, 66% of the radioactivity was trapped in the collected fractions and 12% remained in the extraction vessel. For the more lipophilic N-[11C]methylpiperidyl benzilate, 93% of the activity was collected and less than 1% remained in the extraction vessel. Labeled metabolites were analyzed by LC and also, in the case, of O-[2-11C]acetyl-L-carnitine by LC/MS. The complete extraction procedure, from removal of the biological tissue until an extract was ready for analysis, was 25 min, corresponding to about one half-life of the radionuclide 11C.

Emission computed tomography of /sup 18/F-fluorodeoxyglucose and /sup 13/N-ammonia in stroke and epilepsy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhl, D.E.; Phelps, M.E.; Engel, J. Jr.

1980-01-01

The ECAT Positron Tomograph was used to scan normal control subjects, stroke patients at various times during recovery, and patients with partial epilepsy during EEG monitoring. /sup 18/F-fluorodeoxyglucose (/sup 18/FDG) and /sup 13/N-Ammonia (/sup 13/NH/sub 3/) were used as indicators of abnormalities in local cerebral glucose utilization (LCMR/sub glc/) and relative perfusion, respectively. Hypometabolism, due to deactivation or minimal damage, was demonstrated with the /sup 18/FDG scan in deep structures and broad zones of cerebral cortex which appeared normal on x-ray CT (XCT) and /sup 99m/Tc pertechnetate scans. In patients with partial epilepsy, who had unilateral or focal electrical abnormalities,more » interictal /sup 18/FDG scan patterns clearly showed localized regions of decreased (20 to 50%) LCMR/sub glc/, which correlated anatomically with the eventual EEG localization.« less

Acute Toxicity of Ammonia, Nitrite and Nitrate to Shrimp Litopenaeus vannamei Postlarvae in Low-Salinity Water.

PubMed

Valencia-Castañeda, Gladys; Frías-Espericueta, Martin G; Vanegas-Pérez, Ruth C; Pérez-Ramírez, Jesús A; Chávez-Sánchez, María C; Páez-Osuna, Federico

2018-05-12

Shrimp farming in low salinities waters is an alternative to increasing production, and counteracting disease problems in brackish and marine waters. However, in low-salinity waters, toxicity of nitrogen compounds increases, and there is no available data of its acute toxicity in shrimp postlarvae. This study determined the acute toxicity of ammonia, nitrite and nitrate in Litopenaeus vannamei postlarvae in 1 and 3 g/L salinity, as well as the safety levels. The LC 50 confirms that nitrite is more toxic than ammonia and nitrate in low salinity waters, and that its toxicity increases with a decrease in salinity. The safe levels estimated for salinities of 1 and 3 g/L were 0.54 and 0.81 mg/L for total ammonia-N, 0.17 and 0.25 mg/L for NO 2 -N, and 5.6 and 21.5 mg/L for NO 3 -N, respectively.

Ammonia as a respiratory gas in water and air-breathing fishes.

PubMed

Randall, David J; Ip, Yuen K

2006-11-01

Ammonia is produced in the liver and excreted as NH(3) by diffusion across the gills. Elevated ammonia results in an increase in gill ventilation, perhaps via stimulation of gill oxygen chemo-receptors. Acidification of the water around the fish by carbon dioxide and acid excretion enhances ammonia excretion and constitutes "environmental ammonia detoxification". Fish have difficulties in excreting ammonia in alkaline water or high concentrations of environmental ammonia, or when out of water. The mudskipper, Periphthalmodon schlosseri, is capable of active NH(4)(+) transport, maintaining low internal levels of ammonia. To prevent a back flux of NH(3), these air-breathing fish can increase gill acid excretion and reduce the membrane NH(3) permeability by modifying the phospholipid and cholesterol compositions of their skin. Several air-breathing fish species can excrete ammonia into air through NH(3) volatilization. Some fish detoxify ammonia to glutamine or urea. The brains of some fish can tolerate much higher levels of ammonia than other animals. Studies of these fish may offer insights into the nature of ammonia toxicity in general.

Bilogical Treatment for Ammonia Oxidation in Drinking Water Facilities

EPA Science Inventory

Ammonia is an unregulated compound, but is naturally occurring in many drinking water sources. It is also used by some treatment facilities to produce chloramines for disinfection purposes. Because ammonia is non-toxic, its presence in drinking water is often disregarded. Thro...

Lethal and sublethal effects of ammonia to juvenile Lampsilis mussels (Unionidae) in sediment and water-only exposures

USGS Publications Warehouse

Newton, T.J.; Bartsch, M.R.

2007-01-01

We compared the sensitivity of two juvenile unionid mussels (Lampsilis cardium and Lampsilis higginsii) to ammonia in 96-h water-only and sediment tests by use of mortality and growth measurements. Twenty mussels were placed in chambers buried 2.5 cm into reference sediments to approximate pore-water exposure (sediment tests) or elevated above the bottom of the experimental units (water-only tests). In the sediment tests, a pH gradient existed between the overlying water (mean 8.0), sediment-water interface (mean 7.7), and 2.5 cm depth (mean 7.4). We assumed that mussels were exposed to ammonia in pore water and report effect concentrations in pore water, but if they were exposed to the higher pH water, more of the ammonia would be in the toxic un-ionized (NH 3) form. The only differences in toxicity and growth between mussel species occurred in some of the water-only tests. In sediment tests, median lethal concentrations (LC50s) ranged from 124 to 125 ??g NH3-N/L. In water-only tests, LC50s ranged from 157 to 372 ??g NH3-N/L. In sediment tests, median effective concentrations (EC50s based on growth) ranged from 30 to 32 ??g NH3-N/L. Juvenile mussels in the water-only tests grew poorly and did not exhibit a dose-response relation. These data demonstrate that growth is a sensitive and valuable endpoint for studies on ammonia toxicity with juvenile freshwater mussels and that growth should be measured via sediment tests. ?? 2007 SETAC.

A Novel Method for Relative Quantitation of N-Glycans by Isotopic Labeling Using 18O-Water

PubMed Central

Tao, Shujuan; Orlando, Ron

2014-01-01

Quantitation is an essential aspect of comprehensive glycomics study. Here, a novel isotopic-labeling method is described for N-glycan quantitation using 18O-water. The incorporation of the 18O-labeling into the reducing end of N-glycans is simply and efficiently achieved during peptide-N4-(N-acetyl-β-glucosaminyl) asparagine amidase F release. This process provides a 2-Da mass difference compared with the N-glycans released in 16O-water. A mathematical calculation method was also developed to determine the 18O/16O ratios from isotopic peaks. Application of this method to several standard glycoprotein mixtures and human serum demonstrated that this method can facilitate the relative quantitation of N-glycans over a linear dynamic range of two orders, with high accuracy and reproducibility. PMID:25365792

Amino Acid Synthesis in Photosynthesizing Spinach Cells: Effects of Ammonia on Pool Sizes and Rates of Labeling from 14CO 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larsen, Peder Olesen; Cornwell, Karen L.; Gee, Sherry L.

1981-08-01

In this paper, isolated cells from leaves of Spinacia oleracea have been maintained in a state capable of high rates of photosynthetic CO 2 fixation for more than 60 hours. The incorporation of 14CO 2 under saturating CO 2 conditions into carbohydrates, carboxylic acids, and amino acids, and the effect of ammonia on this incorporation have been studied. Total incorporation, specific radioactivity, and pool size have been determined as a function of time for most of the protein amino acids and for γ-aminobutyric acid. The measurements of specific radio-activities and of the approaches to 14C “saturation” of some amino acidsmore » indicate the presence and relative sizes of metabolically active and passive pools of these amino acids. Added ammonia decreased carbon fixation into carbohydrates and increased fixation into carboxylic acids and amino acids. Different amino acids were, however, affected in different and highly specific ways. Ammonia caused large stimulatory effects in incorporation of 14C into glutamine (a factor of 21), aspartate, asparagine, valine, alanine, arginine, and histidine. No effect or slight decreases were seen in glycine, serine, phenylalanine, and tyrosine labeling. In the case of glutamate, 14C labeling decreased, but specific radioactivity increased. The production of labeled γ-aminobutyric acid was virtually stopped by ammonia. The results indicate that added ammonia stimulates the reactions mediated by pyruvate kinase and phosphoenolpyruvate carboxylase, as seen with other plant systems. Finally, the data on the effects of added ammonia on total labeling, pool sizes, and specific radioactivities of several amino acids provides a number of indications about the intracellular sites of principal synthesis from carbon skeletons of these amino acids and the selective nature of effects of increased intracellular ammonia concentration on such synthesis.« less

Synthesis of ammonia directly from air and water at ambient temperature and pressure.

PubMed

Lan, Rong; Irvine, John T S; Tao, Shanwen

2013-01-01

The N≡N bond (225 kcal mol⁻¹) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N₂ separation and H₂ production stages. A maximum ammonia production rate of 1.14 × 10⁻⁵ mol m⁻² s⁻¹ has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.

Evaluation of influence of sediment on the sensitivity of a unionid mussel (Lampsilis siliquoidea) to ammonia in 28-day water exposures

USGS Publications Warehouse

Wang, N.; Consbrock, R.A.; Ingersoll, C.G.; Barnhart, M.C.

2011-01-01

A draft update of the U.S. Environmental Protection Agency ambient water quality criteria (AWQC) for ammonia substantially lowers the ammonia AWQC, primarily due to the inclusion of toxicity data for freshwater mussels. However, most of the mussel data used in the updated AWQC were generated from water-only exposures and limited information is available on the potential influence of the presence of a substrate on the response of mussels in laboratory toxicity tests. Our recent study demonstrated that the acute sensitivity of mussels to ammonia was not influenced by the presence of substrate in 4-d laboratory toxicity tests. The objective of the current study was to determine the sensitivity of mussels to ammonia in chronic 28-d water exposures with the sediment present (sediment treatment) or absent (water-only treatment). The chronic toxicity test was conducted starting with two-month-old juvenile mussels (fatmucket, Lampsilis siliquoidea) in a flow-through diluter system, which maintained consistent pH (???8.3) and six concentrations of total ammonia nitrogen (N) in overlying water and in sediment pore water. The chronic value (ChV, geometric mean of the no-observed-effect concentration and the lowest-observed-effect concentration) was 0.36mgN/L for survival or biomass in the water-only treatment, and was 0.66mgN/L for survival and 0.20mgN/L for biomass in the sediment treatment. The 20% effect concentration (EC20) for survival was 0.63mgN/L in the water-only treatment and was 0.86mgN/L in the sediment treatment (with overlapping 95% confidence intervals; no EC20 for biomass was estimated because the data did not meet the conditions for any logistic regression analysis). The similar ChVs or EC20s between the water-only treatment and the sediment treatment indicate that the presence of sediment did not substantially influence the sensitivity of juvenile mussels to ammonia in the 28-d chronic laboratory water exposures. ?? 2011 SETAC.

Evaluation of influence of sediment on the sensitivity of a unionid mussel (Lamsilis silquoidea) to ammonia in 28-day water exposures

USGS Publications Warehouse

Wang, Ning; Consbrock, Rebecca A.; Ingersoll, Christopher G.; Barnhart, M. Christopher

2011-01-01

A draft update of the U.S. Environmental Protection Agency ambient water quality criteria (AWQC) for ammonia substantially lowers the ammonia AWQC, primarily due to the inclusion of toxicity data for freshwater mussels. However, most of the mussel data used in the updated AWQC were generated from water-only exposures and limited information is available on the potential influence of the presence of a substrate on the response of mussels in laboratory toxicity tests. Our recent study demonstrated that the acute sensitivity of mussels to ammonia was not influenced by the presence of substrate in 4-d laboratory toxicity tests. The objective of the current study was to determine the sensitivity of mussels to ammonia in chronic 28-d water exposures with the sediment present (sediment treatment) or absent (water-only treatment). The chronic toxicity test was conducted starting with two-month-old juvenile mussels (fatmucket, Lampsilis siliquoidea) in a flow-through diluter system, which maintained consistent pH (≈8.3) and six concentrations of total ammonia nitrogen (N) in overlying water and in sediment pore water. The chronic value (ChV, geometric mean of the no-observed-effect concentration and the lowest-observed-effect concentration) was 0.36 mg N/L for survival or biomass in the water-only treatment, and was 0.66 mg N/L for survival and 0.20 mg N/L for biomass in the sediment treatment. The 20% effect concentration (EC20) for survival was 0.63 mg N/L in the water-only treatment and was 0.86 mg N/L in the sediment treatment (with overlapping 95% confidence intervals; no EC20 for biomass was estimated because the data did not meet the conditions for any logistic regression analysis). The similar ChVs or EC20s between the water-only treatment and the sediment treatment indicate that the presence of sediment did not substantially influence the sensitivity of juvenile mussels to ammonia in the 28-d chronic laboratory water exposures.

Positron emitting nuclides and their synthetic incorporation in radiopharmaceuticals. [Labeled with /sup 11/C, /sup 13/N, and /sup 18/F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fowler, J.S.

/sup 11/C, /sup 13/N, and /sup 15/O has potential applicability to the study of metabolism in humans. Problems in the synthesis of radiopharmaceuticals labeled with /sup 11/C, /sup 13/N, and /sup 18/F are described: quality control, radiation exposure, carboxylic acids, glucose, amines, amino acids, nitrosources, fluoroethanol. 54 references. (DLC)

Variability of 13C-labeling in plant leaves.

PubMed

Nguyen Tu, Thanh Thuy; Biron, Philippe; Maseyk, Kadmiel; Richard, Patricia; Zeller, Bernd; Quénéa, Katell; Alexis, Marie; Bardoux, Gérard; Vaury, Véronique; Girardin, Cyril; Pouteau, Valérie; Billiou, Daniel; Bariac, Thierry

2013-09-15

Plant tissues artificially labeled with (13)C are increasingly used in environmental studies to unravel biogeochemical and ecophysiological processes. However, the variability of (13)C-content in labeled tissues has never been carefully investigated. Hence, this study aimed at documenting the variability of (13)C-content in artificially labeled leaves. European beech and Italian ryegrass were subjected to long-term (13)C-labeling in a controlled-environment growth chamber. The (13)C-content of the leaves obtained after several months labeling was determined by isotope ratio mass spectrometry. The (13)C-content of the labeled leaves exhibited inter- and intra-leaf variability much higher than those naturally occurring in unlabeled plants, which do not exceed a few per mil. This variability was correlated with labeling intensity: the isotope composition of leaves varied in ranges of ca 60‰ and 90‰ for experiments that led to average leaf (13)C-content of ca +15‰ and +450‰, respectively. The reported variability of isotope composition in (13)C-enriched leaves is critical, and should be taken into account in subsequent experimental investigations of environmental processes using (13)C-labeled plant tissues. Copyright © 2013 John Wiley & Sons, Ltd.

Raw Water Ammonia: Implications on Water Quality, Regulatory Compliance, and Management Strategies

EPA Science Inventory

The objective of the talk will be to present engineering design considerations associated with the biological reduction of ammonia from source water. Also, the application of ion exchange softening to address elevated ammonia is presented.

Gas-diffusion-based passive sampler for ammonia monitoring in marine waters.

PubMed

O'Connor Šraj, Lenka; Almeida, M Inês G S; Bassett, Chelsea; McKelvie, Ian D; Kolev, Spas D

2018-05-01

A novel passive sampler based on gas-diffusion across a hydrophobic membrane is described for the determination of the time-weighted average concentration of dissolved molecular ammonia in high ionic strength aquatic environments, such as sea, coastal and estuarine waters, for a period of 3 days. The passive sampler developed is cheap, easy-to-use, reusable, and has a dynamic concentration range of 2.0-12µM, which covers the water quality guideline trigger value of 11.4µM (160µgL -1 NH 3 -N) for high conservation value waters, making this a powerful new tool for water quality managers involved in long-term ammonia monitoring. The gas-diffusion-based passive sampler was calibrated under laboratory conditions and deployed in a tank of seawater in the laboratory and at an estuarine site for proof of concept, and a good agreement between passive and spot sampling was achieved in both cases. Copyright © 2017 Elsevier B.V. All rights reserved.

Balancing the (carbon) budget: Using linear inverse models to estimate carbon flows and mass-balance 13C:15N labelling experiments in low oxygen sediments.

NASA Astrophysics Data System (ADS)

Hunter, William Ross; Van Oevelen, Dick; Witte, Ursula

2013-04-01

Over 1 million km2 of seafloor experience permanent low-oxygen conditions within oxygen minimum zones (OMZs). OMZs are predicted to grow as a consequence of climate change, potentially affecting oceanic biogeochemical cycles. The Arabian Sea OMZ impinges upon the western Indian continental margin at bathyal depths (150 - 1500m) producing a strong depth dependent oxygen gradient at the sea floor. The influence of the OMZ upon the short term processing of organic matter by sediment ecosystems was investigated using in situ stable isotope pulse chase experiments. These deployed doses of 13C:15N labeled organic matter onto the sediment surface at four stations from across the OMZ (water depth 540 - 1100 m; [O2] = 0.35 - 15 μM). In order to prevent experimentally anoxia, the mesocosms were not sealed. 13C and 15N labels were traced into sediment, bacteria, fauna and 13C into sediment porewater DIC and DOC. However, the DIC and DOC flux to the water column could not be measured, limiting our capacity to obtain mass-balance for C in each experimental mesocosm. Linear Inverse Modeling (LIM) provides a method to obtain a mass-balanced model of carbon flow that integrates stable-isotope tracer data with community biomass and biogeochemical flux data from a range of sources. Here we present an adaptation of the LIM methodology used to investigate how ecosystem structure influenced carbon flow across the Indian margin OMZ. We demonstrate how oxygen conditions affect food-web complexity, affecting the linkages between the bacteria, foraminifera and metazoan fauna, and their contributions to benthic respiration. The food-web models demonstrate how changes in ecosystem complexity are associated with oxygen availability across the OMZ and allow us to obtain a complete carbon budget for the stationa where stable-isotope labelling experiments were conducted.

High Resolution 13C MRI With Hyperpolarized Urea: In Vivo T2 Mapping and 15N Labeling Effects

PubMed Central

Reed, Galen D.; von Morze, Cornelius; Bok, Robert; Koelsch, Bertram L.; Van Criekinge, Mark; Smith, Kenneth J.; Shang, Hong; Larson, Peder E. Z.; Kurhanewicz, John; Vigneron, Daniel B.

2014-01-01

13C steady state free precession (SSFP) magnetic resonance imaging and effective spin-spin relaxation time (T2) mapping were performed using hyperpolarized [13C] urea and [13C, 15N2] urea injected intravenously in rats. 15N labeling gave large T2 increases both in solution and in vivo due to the elimination of a strong scalar relaxation pathway. The T2 increase was pronounced in the kidney, with [13C, 15N2] urea giving T2 values of 6.3±1.3 s in the cortex and medulla, and 11±2 s in the renal pelvis. The measured T2 in the aorta was 1.3±0.3 s. [13C] urea showed shortened T2 values in the kidney of 0.23±0.03 s compared to 0.28±0.03 s measured in the aorta. The enhanced T2 of [13C, 15N2] urea was utilized to generate large signal enhancement by SSFP acquisitions with flip angles approaching the fully refocused regime. Projection images at 0.94 mm in-plane resolution were acquired with both urea isotopes, with [13C, 15N2] urea giving a greater than four-fold increase in signal-to-noise ratio [13C] over urea. PMID:24235273

Synthesis and biosynthesis of {sup 13}C-, {sup 15}N-labeled deoxynucleosides useful for biomolecular structural determinations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ashburn, D.A.; Garcia, K.; Hanners, J.L.

Currently, there is a great emphasis on elucidating the structure, function, and dynamics of DNA. Much of the research involved in this study uses nuclear magnetic resonance (NMR) spectroscopy. Effective use of NMR spectroscopy for DNA molecules with mw > 10,000 requires stable isotope enrichment. We present strategies for site-specific isotopic labeling of the purine bases adenosine and guanosine and the biosynthesis of (U-{sup 13}C, {sup 15}N) DNA from methylotropic bacteria. With commercially available 6-chloropurine, an effective two-step route leads to 2{prime}-deoxy-(amino-{sup 15}N)adenosine (dA). The resulting d(amino-{sup 15}N)A is used in a series of reactions to synthesize 2{prime}-deoxy-(2-{sup 13}C,1,amino-{sup 15}N{submore » 2})guanosine or any combination thereof. An improved biosynthesis of labeled DNA has been accomplished using Methylobacterium extorquens AS1. Each liter of growth medium contains 4 g of methanol to yield 1 g of lyophilized cells. As much as 200 mg of RNA per liter of culture has been obtained. We are currently developing large-scale isolation protocols. General synthetic pathways to oligomeric DNA will be presented.« less

Simultaneous Graphite Exfoliation and N Doping in Supercritical Ammonia.

PubMed

Sasikala, Suchithra Padmajan; Huang, Kai; Giroire, Baptiste; Prabhakaran, Prem; Henry, Lucile; Penicaud, Alain; Poulin, Philippe; Aymonier, Cyril

2016-11-16

We report the exfoliation of graphite and simultaneous N doping of graphene by two methods: supercritical ammonia treatment and liquid-phase exfoliation with NH 4 OH. While the supercritical ammonia allowed N doping at a level of 6.4 atom % in 2 h, the liquid-phase exfoliation with NH 4 OH allowed N doping at a level of 2.7 atom % in 6 h. The N doped graphene obtained via the supercritical ammonia route had few layers (<5) and showed large lateral flake size (∼8 μm) and low defect density (I D /I G < 0.6) in spite of their high level of N doping. This work is the first demonstration of supercritical ammonia as an exfoliation agent and N doping precursor for graphene. Notably, the N doped graphene showed electrocatalytic activity toward oxygen reduction reaction with high durability and good methanol tolerance compared to those of commercial Pt/C catalyst.

Corrosion inhibitor for aqueous ammonia absorption system

DOEpatents

Phillips, Benjamin A.; Whitlow, Eugene P.

1998-09-22

A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

Corrosion inhibitor for aqueous ammonia absorption system

DOEpatents

Phillips, B.A.; Whitlow, E.P.

1998-09-22

A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

Comparison of 18F-Labeled Fluoroalkylphosphonium Cations with 13N-NH3 for PET Myocardial Perfusion Imaging.

PubMed

Kim, Dong-Yeon; Kim, Hyeon Sik; Reder, Sybille; Zheng, Jin Hai; Herz, Michael; Higuchi, Takahiro; Pyo, A Young; Bom, Hee-Seung; Schwaiger, Markus; Min, Jung-Joon

2015-10-01

Despite substantial advances in the diagnosis of cardiovascular disease, there is a need for 18F-labeled myocardial perfusion agents for the diagnosis of ischemic heart disease because current PET tracers for myocardial perfusion imaging have a short half-life that limits their widespread clinical use in PET. Thus, 18F-labeled fluoroalkylphosphonium derivatives (18F-FATPs), including (5-18F-fluoropentyl)triphenylphosphonium cation (18F-FPTP), (6-18F-fluorohexyl)triphenylphosphonium cation (18F-FHTP), and (2-(2-18F-fluoroethoxy)ethyl)triphenylphosphonium cation (18F-FETP), were synthesized. The myocardial extraction and image quality of the 18F-FATPs were compared with those of 13N-NH3 in rat models. The first-pass extraction fraction (EF) values of the 18F-FATPs (18F-FPTP, 18F-FHTP, 18F-FETP) and 13N-NH3 were measured in isolated rat hearts perfused with the Langendorff method (flow velocities, 0.5, 4.0, 8.0, and 16.0 mL/min). Normal and myocardial infarction rats were imaged with small-animal PET after intravenous injection of 37 MBq of 18F-FATPs and 13N-NH3. To determine pharmacokinetics, a region of interest was drawn around the heart, and time-activity curves of the 18F-FATPs and 13N-NH3 were generated to obtain the counts per pixel per second. Defect size was analyzed on the basis of polar map images of 18F-FATPs and 13N-NH3. The EF values of 18F-FATPs and 13N-NH3 were comparable at low flow velocity (0.5 mL/min), whereas at higher flows EF values of 18F-FATPs were significantly higher than those of 13N-NH3 (4.0, 8.0, and 16.0 mL/min, P<0.05). Myocardium-to-liver ratios of 18F-FPTP, 18F-FHTP, 18F-FETP, and 13N-NH3 were 2.10±0.30, 4.36±0.20, 3.88±1.03, and 0.70±0.09, respectively, 10 min after injection, whereas myocardium-to-lung ratios were 5.00±0.25, 4.33±0.20, 7.98±1.23, and 2.26±0.14, respectively. Although 18F-FATPs and 13N-NH3 sharply delineated myocardial perfusion defects, defect size on the 13N-NH3 images was significantly smaller than on the

Acute toxicity of ammonia (NH3-N) in sewage effluent to Chironomus riparius: II. Using a generalized linear model

USGS Publications Warehouse

Monda, D.P.; Galat, D.L.; Finger, S.E.; Kaiser, M.S.

1995-01-01

Toxicity of un-ionized ammonia (NH3-N) to the midge, Chironomus riparius was compared, using laboratory culture (well) water and sewage effluent (≈0.4 mg/L NH3-N) in two 96-h, static-renewal toxicity experiments. A generalized linear model was used for data analysis. For the first and second experiments, respectively, LC50 values were 9.4 mg/L (Test 1A) and 6.6 mg/L (Test 2A) for ammonia in well water, and 7.8 mg/L (Test 1B) and 4.1 mg/L (Test 2B) for ammonia in sewage effluent. Slopes of dose-response curves for Tests 1A and 2A were equal, but mortality occurred at lower NH3-N concentrations in Test 2A (unequal intercepts). Response ofC. riparius to NH3 in effluent was not consistent; dose-response curves for tests 1B and 2B differed in slope and intercept. Nevertheless, C. riparius was more sensitive to ammonia in effluent than in well water in both experiments, indicating a synergistic effect of ammonia in sewage effluent. These results demonstrate the advantages of analyzing the organisms entire range of response, as opposed to generating LC50 values, which represent only one point on the dose-response curve.

Ru-N-C Hybrid Nanocomposite for Ammonia Dehydrogenation: Influence of N-doping on Catalytic Activity

PubMed Central

Hien, Nguyen Thi Bich; Kim, Hyo Young; Jeon, Mina; Lee, Jin Hee; Ridwan, Muhammad; Tamarany, Rizcky; Yoon, Chang Won

2015-01-01

For application to ammonia dehydrogenation, novel Ru-based heterogeneous catalysts, Ru-N-C and Ru-C, were synthesized via simple pyrolysis of a mixture of RuCl3·6H2O and carbon black with or without dicyandiamide as a nitrogen-containing precursor at 550 °C. Characterization of the prepared Ru-N-C and Ru-C catalysts via scanning transmission electron microscopy, in conjunction with energy dispersive X-ray spectroscopy, indicated the formation of hollow nanocomposites in which the average sizes of the Ru nanoparticles were 1.3 nm and 5.1 nm, respectively. Compared to Ru-C, the Ru-N-C nanocomposites not only proved to be highly active for ammonia dehydrogenation, giving rise to a NH3 conversion of >99% at 550 °C, but also exhibited high durability. X-ray photoelectron spectroscopy revealed that the Ru active sites in Ru-N-C were electronically perturbed by the incorporated nitrogen atoms, which increased the Ru electron density and ultimately enhanced the catalyst activity.

Amino Acid Selective 13C Labeling and 13C Scrambling Profile Analysis of Protein α and Side-Chain Carbons in Escherichia coli Utilized for Protein Nuclear Magnetic Resonance.

PubMed

Sugiki, Toshihiko; Furuita, Kyoko; Fujiwara, Toshimichi; Kojima, Chojiro

2018-06-20

Amino acid selective isotope labeling is an important nuclear magnetic resonance technique, especially for larger proteins, providing strong bases for the unambiguous resonance assignments and information concerning the structure, dynamics, and intermolecular interactions. Amino acid selective 15 N labeling suffers from isotope dilution caused by metabolic interconversion of the amino acids, resulting in isotope scrambling within the target protein. Carbonyl 13 C atoms experience less isotope scrambling than the main-chain 15 N atoms do. However, little is known about the side-chain 13 C atoms. Here, the 13 C scrambling profiles of the Cα and side-chain carbons were investigated for 15 N scrambling-prone amino acids, such as Leu, Ile, Tyr, Phe, Thr, Val, and Ala. The level of isotope scrambling was substantially lower in 13 Cα and 13 C side-chain labeling than in 15 N labeling. We utilized this reduced scrambling-prone character of 13 C as a simple and efficient method for amino acid selective 13 C labeling using an Escherichia coli cold-shock expression system and high-cell density fermentation. Using this method, the 13 C labeling efficiency was >80% for Leu and Ile, ∼60% for Tyr and Phe, ∼50% for Thr, ∼40% for Val, and 30-40% for Ala. 1 H- 15 N heteronuclear single-quantum coherence signals of the 15 N scrambling-prone amino acid were also easily filtered using 15 N-{ 13 Cα} spin-echo difference experiments. Our method could be applied to the assignment of the 55 kDa protein.

Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

NASA Astrophysics Data System (ADS)

Anheier, N. C., Jr.; McDonald, C. E.; Cuta, J. M.; Cuta, F. M.; Olsen, K. B.

1995-05-01

This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. Pacific Northwest Laboratory (PNL) researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH4(+)). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

Exploiting Uniformly 13C-Labeled Carbohydrates for Probing Carbohydrate-Protein Interactions by NMR Spectroscopy.

PubMed

Nestor, Gustav; Anderson, Taigh; Oscarson, Stefan; Gronenborn, Angela M

2017-05-03

NMR of a uniformly 13 C-labeled carbohydrate was used to elucidate the atomic details of a sugar-protein complex. The structure of the 13 C-labeled Manα(1-2)Manα(1-2)ManαOMe trisaccharide ligand, when bound to cyanovirin-N (CV-N), was characterized and revealed that in the complex the glycosidic linkage torsion angles between the two reducing-end mannoses are different from the free trisaccharide. Distances within the carbohydrate were employed for conformational analysis, and NOE-based distance mapping between sugar and protein revealed that Manα(1-2)Manα(1-2)ManαOMe is bound more intimately with its two reducing-end mannoses into the domain A binding site of CV-N than with the nonreducing end unit. Taking advantage of the 13 C spectral dispersion of 13 C-labeled carbohydrates in isotope-filtered experiments is a versatile means for a simultaneous mapping of the binding interactions on both, the carbohydrate and the protein.

Synthesis of a water-soluble analog of 6-methyl-3-N-alkyl catechol labeled with carbon 13: NMR approach to the reactivity of poison ivy/oak sensitizers toward proteins.

PubMed

Goetz, G; Meschkat, E; Lepoittevin, J P

1999-04-19

A 13-C labeled water soluble derivative of alkylcatechol was synthesized and reacted with human serum albumin in phosphate buffer at pH 7.4 in air to allow a slow oxidation of the catechol into orthoquinone. The formation of several adducts was evidenced by a combination of 13C and 1H-13C correlation NMR. Although some adducts could result from a classical o-quinone formation - Michael type addition, our results suggest that a second pathway, involving a direct reaction of a carbon centered radical with proteins could be an important mechanism in the formation of modified proteins.

Process for removal of ammonia and acid gases from contaminated waters

DOEpatents

King, C. Judson; MacKenzie, Patricia D.

1985-01-01

Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

Process for removal of ammonia and acid gases from contaminated waters

DOEpatents

King, C.J.; Mackenzie, P.D.

1982-09-03

Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

The ammonia-water system and the chemical differentiation of icy satellites

USGS Publications Warehouse

Hogenboom, D.L.; Kargel, J.S.; Consolmagno, G.J.; Holden, T.C.; Lee, L.; Buyyounouski, M.

1997-01-01

We report the discovery of the first high-pressure polymorphs of ammonia hydrates: ammonia monohydrate II and ammonia dihydrate II. The subsolidus transitions and melting curves of these substances are shown by their volume-temperature functions; uncalibrated calorimetry corroborates these phase changes. From 20 to 300 MPa ammonia dihydrate and ice melt at a eutectic to form water-rich liquids; at lower and higher pressures, ammonia dihydrate melts incongruently to ammonia-rich liquids. The new data are consistent with independently known thermodynamic parameters of the ammonia-water system. These results fill in an important region of pressure-temperature space not previously studied; a body of previous data reported by other investigators covers a complementary region (higher pressures), but in the light of the new data those earlier results now appear to have been misinterpreted. We show that a suitable reinterpretation of the previous data supports the identification of at least one high-pressure polymorph of each compound. The behavior of the system H2O-NH3in many ways follows that of MgO-SiO2, and the roles of ammonia-water in icy satellite evolution may parallel those of magnesium silicates in Earth's structure, volcanism, and deep mantle tectonism. Pressure-related effects, including a pressure influence on the ammonia content of cryomagmas, might be significant in determining some potentially observable aspects of cryovolcanic morphologies, surface compositions, and interior structures of icy satellites. ?? 1997 Academic Press.

Ammonia-oxidizing bacteria dominate ammonia oxidation in a full-scale wastewater treatment plant revealed by DNA-based stable isotope probing.

PubMed

Pan, Kai-Ling; Gao, Jing-Feng; Li, Hong-Yu; Fan, Xiao-Yan; Li, Ding-Chang; Jiang, Hao

2018-05-01

A full-scale wastewater treatment plant (WWTP) with three separate treatment processes was selected to investigate the effects of seasonality and treatment process on the community structures of ammonia-oxidizing archaea (AOA) and bacteria (AOB). And then DNA-based stable isotope probing (DNA-SIP) was applied to explore the active ammonia oxidizers. The results of high-throughput sequencing indicated that treatment processes varied AOB communities rather than AOA communities. AOA slightly outnumbered AOB in most of the samples, whose abundance was significantly correlated with temperature. DNA-SIP results showed that the majority of AOB amoA gene was labeled by 13 C-substrate, while just a small amount of AOA amoA gene was labeled. As revealed by high-throughput sequencing of heavy DNA, Nitrosomonadaceae-like AOB, Nitrosomonas sp. NP1, Nitrosomonas oligotropha and Nitrosomonas marina were the active AOB, and Nitrososphaera viennensis dominated the active AOA. The results indicated that AOB, not AOA, dominated active ammonia oxidation in the test WWTP. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ammonia Adsorption and Co-adsorption with Water in HKUST-1: Spectroscopic Evidence for Cooperative Interactions

DOE PAGES

Nijem, Nour; Fürsich, Katrin; Bluhm, Hendrik; ...

2015-10-09

Ammonia interactions and competition with water at the interface of nanoporous metal organic framework thin films of HKUST-1 (Cu 3Btc 2 , Btc = 1,3,5-benzenedicarboxylate) are investigated with ambient pressure X-ray photoelectron spectroscopy (APXPS). In the absence of water, ammonia adsorption at the Cu 2+ metal center weakens the metal-linker bond of the framework. In the presence of water, due to the higher binding energy (adsorption strength) of ammonia compared to water, ammonia replaces water at the unsaturated Cu 2+ metal centers. The water molecules remaining in the pores are stabilized by hydrogen bonding to ammonia. Hydrogen bonding between themore » water and ammonia strengthens the metal-ammonia interaction due to cooperative interactions. Cooperative interactions result in a reduction in the metal center oxidation state facilitating linker replacement by other species explaining the previously reported structure degradation.« less

Ammonia Adsorption and Co-adsorption with Water in HKUST-1: Spectroscopic Evidence for Cooperative Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nijem, Nour; Fürsich, Katrin; Bluhm, Hendrik

Ammonia interactions and competition with water at the interface of nanoporous metal organic framework thin films of HKUST-1 (Cu 3Btc 2 , Btc = 1,3,5-benzenedicarboxylate) are investigated with ambient pressure X-ray photoelectron spectroscopy (APXPS). In the absence of water, ammonia adsorption at the Cu 2+ metal center weakens the metal-linker bond of the framework. In the presence of water, due to the higher binding energy (adsorption strength) of ammonia compared to water, ammonia replaces water at the unsaturated Cu 2+ metal centers. The water molecules remaining in the pores are stabilized by hydrogen bonding to ammonia. Hydrogen bonding between themore » water and ammonia strengthens the metal-ammonia interaction due to cooperative interactions. Cooperative interactions result in a reduction in the metal center oxidation state facilitating linker replacement by other species explaining the previously reported structure degradation.« less

IRMS detection of testosterone manipulated with 13C labeled standards in human urine by removing the labeled 13C.

PubMed

Wang, Jingzhu; Yang, Rui; Yang, Wenning; Liu, Xin; Xing, Yanyi; Xu, Youxuan

2014-12-10

Isotope ratio mass spectrometry (IRMS) is applied to confirm testosterone (T) abuse by determining the carbon isotope ratios (δ(13)C value). However, (13)C labeled standards can be used to control the δ(13)C value and produce manipulated T which cannot be detected by the current method. A method was explored to remove the (13)C labeled atom at C-3 from the molecule of androsterone (Andro), the metabolite of T in urine, to produce the resultant (A-nor-5α-androstane-2,17-dione, ANAD). The difference in δ(13)C values between Andro and ANAD (Δδ(13)CAndro-ANAD, ‰) would change significantly in case manipulated T is abused. Twenty-one volunteers administered T manipulated with different (13)C labeled standards. The collected urine samples were analyzed with the established method, and the maximum value of Δδ(13)CAndro-ANAD post ingestion ranged from 3.0‰ to 8.8‰. Based on the population reference, the cut-off value of Δδ(13)CAndro-ANAD for positive result was suggested as 1.2‰. The developed method could be used to detect T manipulated with 3-(13)C labeled standards. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of pore-water ammonia on in situ survival and growth of juvenile mussels (Lampsilis cardium) in the St. Croix Riverway, Wisconsin, USA

USGS Publications Warehouse

Bartsch, Michelle; Newton, Teresa J.; Allran, John W.; O'Donnell, Jonathan A.; Richardson, William B.

2003-01-01

We conducted a series of in situ tests to evaluate the effects of pore-water ammonia on juvenile Lampsilis cardium in the St. Croix River (WI, USA). Threats to this river and its associated unionid fauna have accelerated in recent years because of its proximity to Minneapolis-St. Paul, Minnesota, USA. In 2000, caged juveniles were exposed to sediments and overlying water at 12 sites for 10 d. Survival and growth of juveniles was significantly different between sediment (mean, 47%) and water column (mean, 86%) exposures; however, these effects were unrelated to pore-water ammonia. During 2001, juveniles were exposed to sediments for 4, 10, and 28 d. Pore-water ammonia concentrations ranged from 0.3 to 62.0 μg NH3-N/L in sediments and from 0.5 to 140.8 μg NH3-N/L within exposure chambers. Survival (mean, 45, 28, and 41% at 4, 10, and 28 d, respectively) and growth (range, 3-45 μm/d) of juveniles were highly variable and generally unrelated to ammonia concentrations. Although laboratory studies have shown unionids to be quite sensitive to ammonia, further research is needed to identify the route(s) of ammonia exposure in unionids and to understand the factors that contribute to the spatial variability of ammonia in rivers.

Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anheier, N.C. Jr.; McDonald, C.E.; Cuta, J.M.

1995-05-01

This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose of this work was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. PNL researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation,more » sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH{sub 4}{sup +}). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.« less

Comparison of clinical tools for measurements of regional stress and rest myocardial blood flow assessed with 13N-ammonia PET/CT.

PubMed

Slomka, Piotr J; Alexanderson, Erick; Jácome, Rodrigo; Jiménez, Moises; Romero, Edgar; Meave, Aloha; Le Meunier, Ludovic; Dalhbom, Magnus; Berman, Daniel S; Germano, Guido; Schelbert, Heinrich

2012-02-01

Several models for the quantitative analysis of myocardial blood flow (MBF) at stress and rest and myocardial flow reserve (MFR) with (13)N-ammonia myocardial perfusion PET have been implemented for clinical use. We aimed to compare quantitative results obtained from 3 software tools (QPET, syngo MBF, and PMOD), which perform PET MBF quantification with either a 2-compartment model (QPET and syngo MBF) or a 1-compartment model (PMOD). We considered 33 adenosine stress and rest (13)N-ammonia studies (22 men and 11 women). Average age was 54.5 ± 15 y, and average body mass index was 26 ± 4.2. Eighteen patients had a very low likelihood of disease, with no chest pain, normal relative perfusion results, and normal function. All data were obtained on a PET/CT scanner in list mode with CT attenuation maps. Sixteen dynamic frames were reconstructed (twelve 10-s, two 30-s, one 1-min, and one 6-min frames). Global and regional stress and rest MBF and MFR values were obtained with each tool. Left ventricular contours and input function region were obtained automatically in system QPET and syngo MBF and manually in PMOD. The flow values and MFR values were highly correlated among the 3 packages (R(2) ranging from 0.88 to 0.92 for global values and from 0.78 to 0.94 for regional values. Mean reference MFR values were similar for QPET, syngo MBF, and PMOD (3.39 ± 1.22, 3.41 ± 0.76, and 3.66 ± 1.19, respectively) by 1-way ANOVA (P = 0.74). The lowest MFR in very low likelihood patients in any given vascular territory was 2.25 for QPET, 2.13 for syngo MBF, and 2.23 for PMOD. Different implementations of 1- and 2-compartment models demonstrate an excellent correlation in MFR for each vascular territory, with similar mean MFR values.

Utilization of the CS-30 cyclotron at the Duke University Medical Center

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wieland, B.W.; McKinney, C.J.; Dailey, M.F.

1994-12-31

Present routine radionuclide production includes {sup 18}F fluoride from protons on {sup 18}O water, {sup 13}N ammonia from protons on {sup 13}C slurry, {sup 15}O water from deuterons on nitrogen gas, and {sup 211}At from alphas on bismuth metal. Clinical PET using two tomographs (GE 4096 and Advance) is done Tuesday through Friday, typically 4 to 11 patients per day using {sup 15}O water, {sup 13}N ammonia, and {sup 18}F FDG synthesized with a GE Microlab. Clinical patient studies are 50% neurology using FDG, 45% body using FDG, and 5% cardiology using ammonia and FDG (oncology in these three areasmore » totals 60%). {sup 15}O water for clinical research patients (THC and cognitive) is produced twice a week. {sup 211}At is produced about twice a week for monoclonal antibody labelling.« less

Metabolism of Nonessential N15-Labeled Amino Acids and the Measurement of Human Whole-Body Protein Synthesis Rates

NASA Technical Reports Server (NTRS)

Stein, T. P.; Settle, R. G.; Albina, J. A.; Dempsey, D. T.; Melnick, G.

1991-01-01

Eight N-15 labeled nonessential amino acids plus (15)NH4Cl were administered over a 10 h period to four healthy adult males using a primed-constant dosage regimen. The amount of N-15 excreted in the urine and the urinary ammonia, hippuric acid, and plasma alanine N-15 enrichments were measured. There was a high degree of consistency across subjects in the ordering of the nine compounds based on the fraction of N-15 excreted (Kendall coefficient of concordance W = 0.83, P is less than 0.01). Protein synthesis rates were calculated from the urinary ammonia plateau enrichment and the cumulative excretion of N-15. Glycine was one of the few amino acids that gave similar values by both methods.

Rheology of water and ammonia-water ices

NASA Technical Reports Server (NTRS)

Goldsby, D. L.; Kohlstedt, D. L.; Durham, W. B.

1993-01-01

Creep experiments on fine-grained water and ammonia-water ices have been performed at one atmosphere and high confining pressure in order to develop constitutive relationships necessary to model tectonic processes and interpret surface features of icy moons of the outer solar system. The present series of experiments explores the effects of temperature, strain rate, grain size, and melt fraction on creep strength. In general, creep strength decreases with increasing temperature, decreasing strain rate, and increasing melt fraction. A transition from dislocation creep to diffusion creep occurs at finer grain sizes, higher temperatures, and lower strain rates.

A cost-effective approach to produce 15N-labelled amino acids employing Chlamydomonas reinhardtii CC503.

PubMed

Nicolás Carcelén, Jesús; Marchante-Gayón, Juan Manuel; González, Pablo Rodríguez; Valledor, Luis; Cañal, María Jesús; Alonso, José Ignacio García

2017-08-18

The use of enriched stable isotopes is of outstanding importance in chemical metrology as it allows the application of isotope dilution mass spectrometry (IDMS). Primary methods based on IDMS ensure the quality of the analytical measurements and traceability of the results to the international system of units. However, the synthesis of isotopically labelled molecules from enriched stable isotopes is an expensive and a difficult task. Either chemical and biochemical methods to produce labelled molecules have been proposed, but so far, few cost-effective methods have been described. The aim of this study was to use the microalgae Chlamydomonas reinhardtii to produce, at laboratory scale, 15 N-labelled amino acids with a high isotopic enrichment. To do that, a culture media containing 15 NH 4 Cl was used. No kinetic isotope effect (KIE) was observed. The labelled proteins biosynthesized by the microorganism were extracted from the biomass and the 15 N-labelled amino acids were obtained after a protein hydrolysis with HCl. The use of the wall deficient strain CC503 cw92 mt+ is fit for purpose, as it only assimilates ammonia as nitrogen source, avoiding isotope contamination with nitrogen from the atmosphere or the reagents used in the culture medium, and enhancing the protein extraction efficiency compared to cell-walled wild type Chlamydomonas. The isotopic enrichment of the labelled amino acids was calculated from their isotopic composition measured by gas chromatography mass spectrometry (GC-MS). The average isotopic enrichment for the 16 amino acids characterized was 99.56 ± 0.05% and the concentration of the amino acids in the hydrolysate ranged from 18 to 90 µg/mL. Previously reported biochemical methods to produce isotopically labelled proteins have been applied in the fields of proteomics and fluxomics. For these approaches, low amounts of products are required and the isotopic enrichment of the molecules has never been properly determined. So far, only 13

AUTORADIOGRAPHIC LOCALIZATION OF 13N AFTER FIXATION OF 13N-LABELED NITROGEN GAS BY A HETEROCYST-FORMING BLUE-GREEN ALGA

PubMed Central

Wolk, C. Peter; Austin, Sam M.; Bortins, John; Galonsky, Aaron

1974-01-01

13N, generated by proton bombardment of 13C powder, is rapidly and easily converted to 13N-N2, 0.01 atm pressure, ca. 10 mCi/ml, by automated Dumas combustion. 13N fixed (as 13N-N2) by algal filaments was localized by an autoradiographic technique which permits track autoradiography with isotopes having short half-lives. Our findings show directly that a minimum of about 25% of the N2 fixation by intact, aerobically grown filaments of Anabaena cylindrica is carried out by the heterocysts. If all of the N2 fixation takes place in the heterocysts, then the movement of nitrogen along the filaments can be characterized by a constant τ < ca. 5 s (cell-2). PMID:4208073

Specific coupling between the 13-keto carbonyl and chlorin skeletal vibrational modes of synthetic 13 1- 18O-(un)labelled metallochlorophyll derivatives

NASA Astrophysics Data System (ADS)

Morishita, Hidetada; Tamiaki, Hitoshi

2009-03-01

Metal complexes of methyl 13 1- 18O-labelled pyropheophorbide- a1-M- 18O (M = Zn, Cu and Ni) were prepared by metallation of the 18O-labelled free base ( 1- 18O) and 18O-labelling of unlabelled nickel complex ( 1-Ni). The FT-IR spectra of 1-Zn and 1-Zn- 18O in CH 2Cl 2 showed that the 13-keto carbonyl stretching vibration mode moved to about a 30-cm -1 lower wavenumber by 18O-labelling of the 13 1-oxo moiety. In 1-Cu- 18O and 1-Ni- 18O, the 13-C dbnd 18O stretching modes were close to the highest-energy wavenumber mode of chlorin skeletal C-C/C-N vibrations at around 1650 cm -1 and they were coupled in CH 2Cl 2 to give two split IR bands (Fermi resonance). A similar coupling was observed in the resonance Raman scattering of 1-Ni- 18O in the solid state. The hydrogen-bonded 13-C dbnd 16O vibration mode of 1-Ni similarly coupled with the skeletal C-C/C-N mode in CCl 4 containing 1% (v/v) 1,1,1,3,3,3-hexafluoro-2-propanol, while such a coupling was not observed in a neat CCl 4 solution of 1-Ni possessing the 13-C dbnd 16O free from any interaction. The skeletal C-C/C-N band selectively coupled with the 13-C dbnd O, not with the 3-C dbnd O, when the difference in their peak maxima was less than 20 cm -1.

Metabolism of nonessential N-15-labeled amino acids and the measurement of human whole-body protein synthesis rates

NASA Technical Reports Server (NTRS)

Stein, T. P.; Settle, R. G.; Albina, J. A.; Melnick, G.; Dempsey, D. T.

1991-01-01

Eight N-15-labeled nonessential amino acids plus (N-15)H4Cl were administered over a 10-h period to four healthy adult males using a primed-constant dosage regimen. The amount of N-15 excreted in the urine and the urinary ammonia, hippuric acid, and plasma alanine N-15 enrichments were measured. There was a high degree of consistency across subjects in the ordering of the nine compounds based on the fraction of N-15 excreted.

Differential Effects of Temperature on Oxygen Consumption and Branchial Fluxes of Urea, Ammonia, and Water in the Dogfish Shark (Squalus acanthias suckleyi).

PubMed

Giacomin, Marina; Schulte, Patricia M; Wood, Chris M

Environmental temperature can greatly influence the homeostasis of ectotherms through its effects on biochemical reactions and whole-animal physiology. Elasmobranchs tend to be N limited and are osmoconformers, retaining ammonia and urea-N at the gills and using the latter as a key osmolyte to maintain high blood osmolality. However, the effects of temperature on these key processes remain largely unknown. We evaluated the effects of acute exposure to different temperatures (7°, 12°, 15°, 18°, 22°C) on oxygen consumption, ammonia, urea-N, and diffusive water fluxes at the gills of Squalus acanthias suckleyi. We hypothesized that as metabolic demand for oxygen increased with temperature, the fluxes of ammonia, urea-N, and 3 H 2 O at the gills would increase in parallel with those of oxygen. Oxygen consumption (overall [Formula: see text] from 7.5° to 22°C) and water fluxes (overall [Formula: see text]) responded to increases in temperature in a similar, almost linear, manner. Ammonia-N efflux rates varied the most, increasing almost 15-fold from 7.5° to 22°C ([Formula: see text]). Urea-N efflux was tightly conserved over the 7.5°-15°C range ([Formula: see text]) but increased greatly at higher temperatures, yielding an overall [Formula: see text]. These differences likely reflect differences in the transport pathways for the four moieties. They also suggest the failure of urea-N- and ammonia-N-conserving mechanisms at the gill above 15°C. Hyperoxia did not alleviate the effects of high temperature. Indeed, urea-N and ammonia-N effluxes were dramatically increased when animals were exposed to high temperatures in the presence of hyperoxia, suggesting that high partial pressure of oxygen may have caused oxidative damage to gill epithelial membranes.

An in-Situ Chemical Analyzer for the Determination of Trace Ammonia in Natural Waters

NASA Astrophysics Data System (ADS)

Amornthammarong, N.; Ortner, P. B.; Hendee, J. C.

2014-12-01

In recent decades chemists have devoted a considerable effort to automating classical wet chemistry. The instruments manufactured for analysis of a large number of samples can be categorized into two main groups—batch and continuous flow analyzers. Our technique, autonomous batch analyzer (ABA), takes advantages of previously described batch analysis and continuous flow analysis. With its simpler design, ABA is robust, flexible, inexpensive, and requires minimal maintenance. ABA achieves complete mixing of sample with reagents using a syringe and a simple mixing chamber. The system can autonomously produce a calibration curve by auto-diluting a single stock standard solution. In addition it incorporates a pre-filtering subsystem enabling measurements in turbid, sediment-laden waters. Over the typical range for ammonia in marine waters (0-10 µM), the response is linear (r2 = 0.9930) with a limit of detection (S/N ratio > 3) of 10 nM. The working range for marine waters is 0.05-10 µM. Repeatability is 0.3% (n = 10) at an ammonia level of 2 μM. Results from automated operation in 15 min cycles over 16 days had good overall precision (RSD = 3%, n = 660). The system was field tested at three shallow South Florida sites, a tidal pond and the Indian River Lagoon, FL. Diurnal cycles and possibly a tidal influence were expressed in the concentration variability observed.

Effects of pore-water ammonia on in situ survival and growth of juvenile mussels (Lampsilis cardium) in the St. Croix Riverway, Wisconsin, USA

USGS Publications Warehouse

Bartsch, M.R.; Newton, T.J.; Allran, J.W.; O'Donnell, J. A.; Richardson, W.B.

2003-01-01

We conducted a series of in situ tests to evaluate the effects of pore-water ammonia on juvenile Lampsilis cardium in the St. Croix River (WI, USA). Threats to this river and its associated unionid fauna have accelerated in recent years because of its proximity to Minneapolis-St. Paul, Minnesota, USA. In 2000, caged juveniles were exposed to sediments and overlying water at 12 sites for 10 d. Survival and growth of juveniles was significantly different between sediment (mean, 47%) and water column (mean, 86%) exposures; however, these effects were unrelated to pore-water ammonia. During 2001, juveniles were exposed to sediments for 4, 10, and 28 d. Pore-water ammonia concentrations ranged from 0.3 to 62.0 ??g NH3-NIL in sediments and from 0.5 to 140.8 ??g NH3-N/L within exposure chambers. Survival (mean, 45, 28, and 41% at 4, 10, and 28 d, respectively) and growth (range, 3-45 ??,m/d) of juveniles were highly variable and generally unrelated to ammonia concentrations. Although laboratory studies have shown unionids to be quite sensitive to ammonia, further research is needed to identify the route(s) of ammonia exposure in unionids and to understand the factors that contribute to the spatial variability of ammonia in rivers.

WaterSense Labeled New Homes

EPA Pesticide Factsheets

Homes built to meet EPA's specification can earn the WaterSense label. EPA criteria include WaterSense labeled plumbing fixtures, efficient hot water delivery systems, water-smart landscape design, and other features.

BLISTERING AND EXPLOSIVE DESORPTION OF IRRADIATED AMMONIA-WATER MIXTURES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loeffler, M. J.; Baragiola, R. A., E-mail: mark.loeffler@nasa.gov, E-mail: raul@virginia.edu

2012-01-10

We present laboratory studies on the thermal evolution of a solid ammonia-water mixture after it has been irradiated at 20, 70, and 120 K. In samples irradiated at {<=}70 K, we observed fast outbursts that appear to indicate grain ejection and correlate well with the formation of micron-sized scattering centers. The occurrence of this phenomenon at the lower irradiation temperatures indicates that our results may be most relevant for understanding the release of gas and grains by comets and the surfaces of some of the colder icy satellites. We observe outgassing at temperatures below those where ice sublimates, which suggestsmore » that comets containing radiolyzed material may have outbursts farther from the Sun that those that are passive. In addition, the estimated size of the grains ejected from our sample is on the order of the size of E-ring particles, suggesting that our results give a plausible mechanism for how micron-sized grains could be formed from an icy surface. Finally, we propose that the presence of the {approx}4.5 {mu}m N{sub 2}O absorption band on an icy surface in outer space will serve to provide indirect evidence for radiation-processed ices that originally contained ammonia or nitrogen, which could be particularly useful since nitrogen is such a weak absorber in the infrared and ammonia is rapidly decomposed by radiolysis.« less

Differential ammonia metabolism in Aedes aegypti fat body and midgut tissues

PubMed Central

Scaraffia, Patricia Y.; Zhang, Quigfen; Thorson, Kelsey; Wysocki, Vicki H.; Miesfeld, Roger L.

2010-01-01

In order to understand at the tissue level how Aedes aegypti copes with toxic ammonia concentrations that result from the rapid metabolism of blood meal proteins, we investigated the incorporation of 15N from 15NH4Cl into amino acids using an in vitro tissue culture system. Fat body or midgut tissues from female mosquitoes were incubated in an Aedes saline solution supplemented with glucose and 15NH4Cl for 10–40 minutes. The media was then mixed with deuterium-labeled amino acids, dried and derivatized. The 15N-labeled and unlabeled amino acids in each sample were quantified by mass spectrometry techniques. The results demonstrate that both tissues efficiently incorporate ammonia into amino acids, however, the specific metabolic pathways are distinct. In the fat body, the 15N from 15NH4Cl is first incorporated into the amide side chain of Gln and then into the amino group of Gln, Glu, Ala and Pro. This process mainly occurs via the glutamine synthetase (GS) and glutamate synthase (GltS) pathway. In contrast, 15N in midgut is first incorporated into the amino group of Glu and Ala, and then into the amide side chain of Gln. Interestingly, our data show that the GS/GltS pathway is not functional in the midgut. Instead, midgut cells detoxify ammonia by glutamate dehydrogenase, alanine aminotransferase and GS. These data provide new insights into ammonia metabolism in A. aegypti mosquitoes. PMID:20206632

Vulcan Planitia, Type Example of Outer Solar System Ammonia-Water Cryovolcanism

NASA Astrophysics Data System (ADS)

McKinnon, W. B.; Beyer, R. A.; Schenk, P. M.; Moore, J. M.; Singer, K. N.; White, O. L.; Spencer, J. R.; Cook, J. C.; Grundy, W. M.; Cruikshank, D. P.; Weaver, H. A.; Young, L. A.; Olkin, C. B.; Stern, S. A.; Robbins, S. J.; New Horizons GGI Team; New Horizons Composition Team

2018-06-01

Pluto's moon Charon offered the first clear (ground-based) evidence for the ammonia-water volcanism predicted long ago by J.S. Lewis. New Horizons then obtained compelling evidence for an ammonia-bearing cryovolcanic plain. But how did it get there?

Toxic effects of juvenile sablefish, Anoplopoma fimbria by ammonia exposure at different water temperature.

PubMed

Kim, Jun-Hwan; Park, Hee-Ju; Hwang, In-Ki; Han, Jae-Min; Kim, Do-Hyung; Oh, Chul Woong; Lee, Jung-Sick; Kang, Ju-Chan

2017-09-01

Juvenile sablefish, Anoplopoma fimbria (mean length 17.1±2.4cm, and mean weight 75.6±5.7g) were used to evaluate toxic effects on antioxidant systems, immune responses, and stress indicators by ammonia exposure (0, 0.25, 0.75, and 1.25mg/L) at different water temperature (12 and 17°C) in 1 and 2 months. In antioxidant responses, superoxide dismutase (SOD) and catalase (CAT) were significantly increased by ammonia exposure, whereas glutathione (GSH) was decreased. In immune responses, lysozyme and phagocytosis activity were significantly increased by ammonia exposure. In stress indicators, plasma glucose, heat shock protein 70 (HSP 70), and cortisol were significantly increased. At high water temperature (17°C), alterations by ammonia exposure were more distinctly. The results of this study indicated that ammonia exposure can induce toxic effects in the sablefish, and high water temperature can affect the ammonia exposure toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Ammonia- and nitrite-oxidizing bacterial communities in a pilot-scale chloraminated drinking water distribution system.

PubMed

Regan, John M; Harrington, Gregory W; Noguera, Daniel R

2002-01-01

Nitrification in drinking water distribution systems is a common operational problem for many utilities that use chloramines for secondary disinfection. The diversity of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in the distribution systems of a pilot-scale chloraminated drinking water treatment system was characterized using terminal restriction fragment length polymorphism (T-RFLP) analysis and 16S rRNA gene (ribosomal DNA [rDNA]) cloning and sequencing. For ammonia oxidizers, 16S rDNA-targeted T-RFLP indicated the presence of Nitrosomonas in each of the distribution systems, with a considerably smaller peak attributable to Nitrosospira-like AOB. Sequences of AOB amplification products aligned within the Nitrosomonas oligotropha cluster and were closely related to N. oligotropha and Nitrosomonas ureae. The nitrite-oxidizing communities were comprised primarily of Nitrospira, although Nitrobacter was detected in some samples. These results suggest a possible selection of AOB related to N. oligotropha and N. ureae in chloraminated systems and demonstrate the presence of NOB, indicating a biological mechanism for nitrite loss that contributes to a reduction in nitrite-associated chloramine decay.

Ammonia- and Nitrite-Oxidizing Bacterial Communities in a Pilot-Scale Chloraminated Drinking Water Distribution System

PubMed Central

Regan, John M.; Harrington, Gregory W.; Noguera, Daniel R.

2002-01-01

Nitrification in drinking water distribution systems is a common operational problem for many utilities that use chloramines for secondary disinfection. The diversity of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in the distribution systems of a pilot-scale chloraminated drinking water treatment system was characterized using terminal restriction fragment length polymorphism (T-RFLP) analysis and 16S rRNA gene (ribosomal DNA [rDNA]) cloning and sequencing. For ammonia oxidizers, 16S rDNA-targeted T-RFLP indicated the presence of Nitrosomonas in each of the distribution systems, with a considerably smaller peak attributable to Nitrosospira-like AOB. Sequences of AOB amplification products aligned within the Nitrosomonas oligotropha cluster and were closely related to N. oligotropha and Nitrosomonas ureae. The nitrite-oxidizing communities were comprised primarily of Nitrospira, although Nitrobacter was detected in some samples. These results suggest a possible selection of AOB related to N. oligotropha and N. ureae in chloraminated systems and demonstrate the presence of NOB, indicating a biological mechanism for nitrite loss that contributes to a reduction in nitrite-associated chloramine decay. PMID:11772611

Aerobic nitrous oxide production through N-nitrosating hybrid formation in ammonia-oxidizing archaea.

PubMed

Stieglmeier, Michaela; Mooshammer, Maria; Kitzler, Barbara; Wanek, Wolfgang; Zechmeister-Boltenstern, Sophie; Richter, Andreas; Schleper, Christa

2014-05-01

Soil emissions are largely responsible for the increase of the potent greenhouse gas nitrous oxide (N2O) in the atmosphere and are generally attributed to the activity of nitrifying and denitrifying bacteria. However, the contribution of the recently discovered ammonia-oxidizing archaea (AOA) to N2O production from soil is unclear as is the mechanism by which they produce it. Here we investigate the potential of Nitrososphaera viennensis, the first pure culture of AOA from soil, to produce N2O and compare its activity with that of a marine AOA and an ammonia-oxidizing bacterium (AOB) from soil. N. viennensis produced N2O at a maximum yield of 0.09% N2O per molecule of nitrite under oxic growth conditions. N2O production rates of 4.6±0.6 amol N2O cell(-1) h(-1) and nitrification rates of 2.6±0.5 fmol NO2(-) cell(-1) h(-1) were in the same range as those of the AOB Nitrosospira multiformis and the marine AOA Nitrosopumilus maritimus grown under comparable conditions. In contrast to AOB, however, N2O production of the two archaeal strains did not increase when the oxygen concentration was reduced, suggesting that they are not capable of denitrification. In (15)N-labeling experiments we provide evidence that both ammonium and nitrite contribute equally via hybrid N2O formation to the N2O produced by N. viennensis under all conditions tested. Our results suggest that archaea may contribute to N2O production in terrestrial ecosystems, however, they are not capable of nitrifier-denitrification and thus do not produce increasing amounts of the greenhouse gas when oxygen becomes limiting.

A novel design for a dual stable isotope continuous labeling chamber: results on labeling efficiency and C and N allocation in Andropogon gerardii

NASA Astrophysics Data System (ADS)

Soong, J.; Stewart, C.; Reuss, D.; Pinney, C.; Cotrufo, F. M.

2010-12-01

The use of stable isotope enriched plant material can provide an unobstructed method of studying ecosystem nutrient dynamics between plants, soil, and atmosphere. However, the production of uniformly labeled perennial plant material is challenging due to plant physiological constraints and the mechanics of building and operating an isotope labeling system. In this study we present the design of a novel dual 13C and 15N continuous isotope labeling chamber located at Colorado State University. The chamber is equipped with automatic controls for CO2 concentration, temperature, and humidity, and has successfully been used to grow and label the tallgrass perennial Andropogon gerardii in pots from rhizomes. Three different nitrogen fertilization levels were applied to assess how substrate availability may alter growth and overall performance in the system. The efficiency of the 13C and 15N labeling chamber, its design and overall performance, as well as a full C, N, 13C, and 15N budget of the aboveground biomass, belowground biomass, and soil will be presented. Solid samples were analyzed on an EA-IRMS, while air samples from the chamber were analyzed using a precon-GC-IRMS system. The dual stable isotope labeled A. gerardii produced from this chamber will be used in a decomposition experiment to quantify the relative contribution of aboveground litter derived C to soil respiration, dissolved organic carbon, and various soil organic matter pools. Based on the results of our A. gerardii 13C and 15N labeling experiment we believe that this chamber design can be used to successfully produce dual stable isotope labeled plants for a wide variety of terrestrial nutrient flux experiments.

Carbon-13 and carbon-14 labeled dabigatran etexilate and tritium labeled dabigatran.

PubMed

Latli, Bachir; Kiesling, Ralf; Aßfalg, Stefan; Chevliakov, Max; Hrapchak, Matt; Campbell, Scot; Gonnella, Nina; Busacca, Carl A; Senanayake, Chris H

2016-12-01

Dabigatran etexilate or pradaxa, a novel oral anticoagulant, is a reversible, competitive, direct thrombin inhibitor. It is used to prevent strokes in patients with atrial fibrillation and the formation of blood clots in the veins (deep venous thrombosis) in adults who have had an operation to replace a hip or a knee. Pradaxa is the only novel oral anticoagulant available with both proven superiority to warfarin and a specific reversal agent for use in rare emergency situations. The detailed description of the synthesis of carbon-13 and carbon-14 labeled dabigatran etexilate, and tritium labeled dabigatran is described. The synthesis of carbon-13 dabigatran etexilate was accomplished in eight steps and in 6% overall yield starting from aniline- 13 C 6 . Ethyl bromoacetate-1- 14 C was the reagent of choice in the synthesis of carbon-14 labeled dabigatran etexilate in six steps and 17% overall yield. Tritium labeled dabigatran was prepared using either direct tritium incorporation under Crabtree's catalytic conditions or tritium-dehalogenation of a diiodo-precursor of dabigatran. Copyright © 2016 John Wiley & Sons, Ltd.

21 CFR 1230.13 - Labeling of “poison”.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL CAUSTIC POISON ACT Labeling § 1230.13 Labeling of “poison”. The following are styles of...-point size are required on a label in stating the word “poison” they must not be smaller than those...

21 CFR 1230.13 - Labeling of “poison”.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FEDERAL CAUSTIC POISON ACT Labeling § 1230.13 Labeling of “poison”. The following are styles of...-point size are required on a label in stating the word “poison” they must not be smaller than those...

21 CFR 1230.13 - Labeling of “poison”.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL CAUSTIC POISON ACT Labeling § 1230.13 Labeling of “poison”. The following are styles of...-point size are required on a label in stating the word “poison” they must not be smaller than those...

21 CFR 1230.13 - Labeling of “poison”.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FEDERAL CAUSTIC POISON ACT Labeling § 1230.13 Labeling of “poison”. The following are styles of...-point size are required on a label in stating the word “poison” they must not be smaller than those...

21 CFR 1230.13 - Labeling of “poison”.

Code of Federal Regulations, 2010 CFR

2010-04-01

... FEDERAL CAUSTIC POISON ACT Labeling § 1230.13 Labeling of “poison”. The following are styles of...-point size are required on a label in stating the word “poison” they must not be smaller than those...

Novel process of bio-chemical ammonia removal from air streams using a water reflux system and zeolite as filter media.

PubMed

Vitzthum von Eckstaedt, Sebastian; Charles, Wipa; Ho, Goen; Cord-Ruwisch, Ralf

2016-02-01

A novel biofilter that removes ammonia from air streams and converts it to nitrogen gas has been developed and operated continuously for 300 days. The ammonia from the incoming up-flow air stream is first absorbed into water and the carrier material, zeolite. A continuous gravity reflux of condensed water from the exit of the biofilter provides moisture for nitrifying bacteria to develop and convert dissolved ammonia (ammonium) to nitrite/nitrate. The down-flow of the condensed water reflux washes down nitrite/nitrate preventing ammonium and nitrite/nitrate accumulation at the top region of the biofilter. The evaporation caused by the inflow air leads to the accumulation of nitrite to extremely high concentrations in the bottom of the biofilter. The high nitrite concentrations favour the spontaneous chemical oxidation of ammonium by nitrite to nitrogen (N2). Tests showed that this chemical reaction was catalysed by the zeolite filter medium and allowed it to take place at room temperature. This study shows that ammonia can be removed from air streams and converted to N2 in a fully aerated single step biofilter. The process also overcomes the problem of microorganism-inhibition and resulted in zero leachate production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biosynthetic production of universally (13)C-labelled polyunsaturated fatty acids as reference materials for natural health product research.

PubMed

Le, Phuong Mai; Fraser, Catherine; Gardner, Graeme; Liang, Wei-Wan; Kralovec, Jaroslav A; Cunnane, Stephen C; Windust, Anthony J

2007-09-01

Long-chain polyunsaturated fatty acids (LCPUFA) including eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) have become important natural health products with numerous proven benefits related to brain function and cardiovascular health. Not only are omega-3 fatty acids available in a plethora of dietary supplements, but they are also increasingly being incorporated as triglycerides into conventional foods, including bread, milk, yoghurt and confectionaries. Recently, transgenic oil seed crops and livestock have been developed that enhance omega-3 fatty acid content. This diverse array of matrices presents a difficult analytical challenge and is compounded further by samples generated through clinical research. Stable isotope (13)C-labelled LCPUFA standards offer many advantages as research tools because they may be distinguished from their naturally abundant counterparts by mass spectrometry and directly incorporated as internal standards into analytical procedures. Further, (13)C-labelled LCPUFAs are safe to use as metabolic tracers to study uptake and metabolism in humans. Currently, (13)C-labelled LCPUFAs are expensive, available in limited supply and not in triglyceride form. To resolve these issues, marine heterotrophic microorganisms are being isolated and screened for LCPUFA production with a view to the efficient biosynthetic production of U-(13)C-labelled fatty acids using U-(13)C glucose as a carbon source. Of 37 isolates obtained, most were thraustochytrids, and either DHA or omega-6 docosapentaenoic acid (22:5n-6) were produced as the major LCPUFA. The marine protist Hyalochlorella marina was identified as a novel source of EPA and omega-3 docosapentaenoic acid (22:5n-3). As proof of principle, gram-level production of (13)C-labelled DHA has been achieved with high chemical purity ( >99%) and high (13)C incorporation levels (>90%), as confirmed by NMR and MS analyses. Finally, U-(13)C-DHA was enzymatically re-esterified to

Photoacoustic measurement of ammonia in the atmosphere: influence of water vapor and carbon dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rooth, R.A.; Verhage, A.J.L.; Wouters, L.W.

1990-09-01

The photoacoustic determination of the ammonia concentration in atmospheric air by absorption of CO{sub 2} laser radiation at 9.22 {mu}m is influenced by the presence of H{sub 2}O and CO{sub 2}. Kinetic cooling due to the coupling of excited CO{sub 2} and N{sub 2} levels causes important changes in phase and amplitude of the photoacoustic signal. Theoretical background is presented to deduce the correct NH{sub 3} concentration from the signal. The experimental setup used to perform field measurements is described. Adhesion of NH{sub 3} to the walls of the resonant photoacoustic cell was investigated. Temperature effects are treated. Field datamore » of NH{sub 3} and H{sub 2}O concentrations are presented. Key words: Photoacoustics, ammonia, kinetic cooling, trace gas measurements, ammonia adhesion, acoustic resonance, CO{sub 2} laser radiation, water vapor absorption, carbon dioxide absorption.« less

Nitrate and ammonia contaminations in drinking water and the affecting factors in Hailun, northeast China.

PubMed

Zhao, Xinfeng; Chen, Liding; Zhang, Haiping

2013-03-01

Drinking water samples (N = 228) from domestic tube wells (DTWs) and seven samples from public water supply wells (PWSWs) were collected and tested in Hailun, northeast China. The percentage of samples with nitrate and ammonia concentrations above the maximum acceptable concentration of nitrate, 10 mg N/L, and the maximum ensure concentration of ammonia, 1.5 mg/L, for the DTWs were significantly higher than for the PWSWs. Of the DTWs, an important observation was that the occurrence of groundwater nitrate contamination was directly related to well tube material with different joint pathways. Nitrate in seamless-tube wells was lower statistically significantly than those in multiple-section-tube wells (p < .001). Furthermore, well depth and hydrogeological setting might have some impacts on nitrogen contamination and the major sources of inorganic nitrogen contamination may be nitrogenous chemical fertilizer. Therefore, PWSWs built for all families are the best way to ensure the drinking water safety in villages. For DTWs it is necessary to use seamless tubes and to dig deep enough according to the depth of groundwater level. Improving the efficiency of chemical fertilizer use would also reduce the risk of groundwater contamination.

Study on structures and properties of ammonia clusters (NH3)n (n=1-5) and liquid ammonia in terms of ab initio method and atom-bond electronegativity equalization method ammonia-8P fluctuating charge potential model.

PubMed

Yu, Ling; Yang, Zhong-Zhi

2010-05-07

Structures, binding energies, and vibrational frequencies of (NH(3))(n) (n=2-5) isomers and dynamical properties of liquid ammonia have been explored using a transferable intermolecular potential eight point model including fluctuating charges and flexible body based on a combination of the atom-bond electronegativity equalization and molecular (ABEEM) mechanics (ABEEM ammonia-8P) in this paper. The important feature of this model is to divide the charge sites of one ammonia molecule into eight points region containing four atoms, three sigma bonds, and a lone pair, and allows the charges in system to fluctuate responding to the ambient environment. Due to the explicit descriptions of charges and special treatment of hydrogen bonds, the results of equilibrium geometries, dipole moments, cluster interaction energies, vibrational frequencies for the gas phase of small ammonia clusters, and radial distribution function for liquid ammonia calculated with the ABEEM ammonia-8P potential model are in good agreement with those measured by available experiments and those obtained from high level ab initio calculations. The properties of ammonia dimer are studied in detail involving the structure and one-dimensional, two-dimensional potential energy surface. As for interaction energies, the root mean square deviation is 0.27 kcal/mol, and the linear correlation coefficient reaches 0.994.

Determination of Multiple φ-Torsion Angles in Proteins by Selective and Extensive 13C Labeling and Two-Dimensional Solid-State NMR

NASA Astrophysics Data System (ADS)

Hong, Mei

1999-08-01

We describe an approach to efficiently determine the backbone conformation of solid proteins that utilizes selective and extensive 13C labeling in conjunction with two-dimensional magic-angle-spinning NMR. The selective 13C labeling approach aims to reduce line broadening and other multispin complications encountered in solid-state NMR of uniformly labeled proteins while still enhancing the sensitivity of NMR spectra. It is achieved by using specifically labeled glucose or glycerol as the sole carbon source in the protein expression medium. For amino acids synthesized in the linear part of the biosynthetic pathways, [1-13C]glucose preferentially labels the ends of the side chains, while [2-13C]glycerol labels the Cα of these residues. Amino acids produced from the citric-acid cycle are labeled in a more complex manner. Information on the secondary structure of such a labeled protein was obtained by measuring multiple backbone torsion angles φ simultaneously, using an isotropic-anisotropic 2D correlation technique, the HNCH experiment. Initial experiments for resonance assignment of a selectively 13C labeled protein were performed using 15N-13C 2D correlation spectroscopy. From the time dependence of the 15N-13C dipolar coherence transfer, both intraresidue and interresidue connectivities can be observed, thus yielding partial sequential assignment. We demonstrate the selective 13C labeling and these 2D NMR experiments on a 8.5-kDa model protein, ubiquitin. This isotope-edited NMR approach is expected to facilitate the structure determination of proteins in the solid state.

Ammonia Gas Transport and Reactions in Unsaturated Sediments: Implications for Use as an Amendment to Immobilize Inorganic Contaminants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Lirong; Szecsody, James E.; Truex, Michael J.

Use of gas-phase amendments for in situ remediation of inorganic contaminants in unsaturated sediments of the vadose zone may be advantageous, but there has been limited development and testing of gas remediation technologies. Treatment with ammonia gas has been studied and has a potential for use in treating inorganic contaminants such as uranium because it induces a high pore-water pH causing mineral dissolution and subsequent formation of stable precipitates that decrease the mobility of some contaminants. For field application, knowledge of ammonia transport and the geochemical reactions induced by ammonia is needed. Laboratory studies were conducted to support calculations neededmore » for field treatment design, to quantify advective and diffusive ammonia transport in unsaturated sediments, to evaluate reactions among gas, sediment, and water, and to study reaction-induced pore-water chemistry changes as a function of ammonia delivery conditions. Ammonia gas quickly partitions into sediment pore water and increases pH up to 13.2. Injected ammonia gas front movement can be reasonably predicted by gas flow rate and equilibrium partitioning. The ammonia gas diffusion rate is a function of the water content in the sediment. Measured diffusion front movement was 0.05, 0.03, and 0.02 cm/hr. in sediments with 2.0%, 8.7%, and 13.0% water content, respectively. Sodium, aluminum, and silica pore-water concentrations increase on exposure to ammonia and then decline as aluminosilicates precipitate with declining pH. When uranium is present in the sediment and pore water, up to 85% of the water-leachable uranium was immobilized by ammonia treatment.« less

Elevated Natural Source Water Ammonia and Nitrification in the Distribution Systems of Four Water Utilities

EPA Science Inventory

Nitrification in drinking water distribution systems is a concern of many drinking water systems. Although chloramination as a source of nitrification (i.e., addition of excess ammonia or breakdown of chloramines) has drawn the most attention, many source waters contain signific...

Tolerance of ciliated protozoan Paramecium bursaria (Protozoa, Ciliophora) to ammonia and nitrites

NASA Astrophysics Data System (ADS)

Xu, Henglong; Song, Weibo; Lu, Lu; Alan, Warren

2005-09-01

The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32 x 9.51 ( R 2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h-LC50 value for ammonia was found to be 95.50 mg/L. A linear correlation between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equation y=2.86 x+0.89 ( R 2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2 862.85 e -0.08 x ( R 2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y=127.15 e -0.13 x ( R 2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.

13C metabolic flux analysis: optimal design of isotopic labeling experiments.

PubMed

Antoniewicz, Maciek R

2013-12-01

Measuring fluxes by 13C metabolic flux analysis (13C-MFA) has become a key activity in chemical and pharmaceutical biotechnology. Optimal design of isotopic labeling experiments is of central importance to 13C-MFA as it determines the precision with which fluxes can be estimated. Traditional methods for selecting isotopic tracers and labeling measurements did not fully utilize the power of 13C-MFA. Recently, new approaches were developed for optimal design of isotopic labeling experiments based on parallel labeling experiments and algorithms for rational selection of tracers. In addition, advanced isotopic labeling measurements were developed based on tandem mass spectrometry. Combined, these approaches can dramatically improve the quality of 13C-MFA results with important applications in metabolic engineering and biotechnology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Archaea produce lower yields of N2 O than bacteria during aerobic ammonia oxidation in soil.

PubMed

Hink, Linda; Nicol, Graeme W; Prosser, James I

2017-12-01

Nitrogen fertilisation of agricultural soil contributes significantly to emissions of the potent greenhouse gas nitrous oxide (N 2 O), which is generated during denitrification and, in oxic soils, mainly by ammonia oxidisers. Although laboratory cultures of ammonia oxidising bacteria (AOB) and archaea (AOA) produce N 2 O, their relative activities in soil are unknown. This work tested the hypothesis that AOB dominate ammonia oxidation and N 2 O production under conditions of high inorganic ammonia (NH 3 ) input, but result mainly from the activity of AOA when NH 3 is derived from mineralisation. 1-octyne, a recently discovered inhibitor of AOB, was used to distinguish N 2 O production resulting from archaeal and bacterial ammonia oxidation in soil microcosms, and specifically inhibited AOB growth, activity and N 2 O production. In unamended soils, ammonia oxidation and N 2 O production were lower and resulted mainly from ammonia oxidation by AOA. The AOA N 2 O yield relative to nitrite produced was half that of AOB, likely due to additional enzymatic mechanisms in the latter, but ammonia oxidation and N 2 O production were directly linked in all treatments. Relative contributions of AOA and AOB to N 2 O production, therefore, reflect their respective contributions to ammonia oxidation. These results suggest potential mitigation strategies for N 2 O emissions from fertilised agricultural soils. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Nitrification and the ammonia-oxidizing communities in the central Baltic Sea water column

NASA Astrophysics Data System (ADS)

Jäntti, Helena; Ward, Bess B.; Dippner, Joachim W.; Hietanen, Susanna

2018-03-01

The redoxclines that form between the oxic and anoxic water layers in the central Baltic Sea are sites of intensive nitrogen cycling. To gain better understanding of nitrification, we measured the biogeochemical properties along with potential nitrification rates and analyzed the assemblages of ammonia-oxidizing bacteria and archaea using functional gene microarrays. To estimate nitrification in the entire water column, we constructed a regression model for the nitrification rates and applied it to the conditions prevailing in the area in 2008-2012. The highest ammonia oxidation rates were found in a thin layer at the top of the redoxcline and the rates quickly decreased below detection limit when oxygen was exhausted. This is probably because extensive suboxic layers, which are known to harbor pelagic nitrification, are formed only for short periods after inflows in the Baltic Sea. The nitrification rates were some of the highest measured in the water columns, but the thickness of the layer where conditions were favorable for nitrification, was very small and it remained fairly stable between years. However, the depth of the nitrification layer varied substantially between years, particularly in the eastern Gotland Basin (EGB) due to turbulence in the water column. The ammonia oxidizer communities clustered differently between the eastern and western Gotland Basin (WGB) and the composition of ammonia-oxidizing assemblages correlated with the environmental variables. The ammonia oxidizer community composition was more even in the EGB, which may be related to physical instability of the redoxcline that does not allow predominance of a single archetype, whereas in the WGB, where the position of the redoxcline is more constant, the ammonia-oxidizing community was less even. Overall the ammonia-oxidizing communities in the Baltic Sea redoxclines were very evenly distributed compared to other marine environments where microarrays have been applied previously.

The ammonia-water phase diagram and its implications for icy satellites

NASA Technical Reports Server (NTRS)

Johnson, M. L.; Nicol, M.

1986-01-01

A Holzapfel-type diamond anvil cell is used to determine the NH3 - H2O phase diagram in the region from 0 to 33 mole percent NH3, 240 to 370 K, and 0 to 5 GPa. The following phases were identified: liquid; water ices Ih, III, V, VI, VII, and VIII; ammonia monohydrate, NH3.H2O; and ammonia dihydrate NH3.2H2O. Ammonia dihydrate becomes prominent at moderate pressures (less than 1 GPa), with planetologically significant implications, including the possibility of layering in Titan's magma ocean.

The ammonia-water phase diagram and its implications for icy satellites

NASA Technical Reports Server (NTRS)

Johnson, Mary L.; Nicol, Malcolm

1987-01-01

A Holzapfel-type diamond anvil cell is used to determine the NH3 - H2O phase diagram in the region from 0 to 33 mole percent NH3, 240 to 370 K, and 0 to 5 GPa. The following phases were identified: liquid; water ices Ih, III, V, VI, VII, and VIII; ammonia monohydrate, NH3.H2O; and ammonia dihydrate NH3.2H2O. Ammonia dihydrate becomes prominent at moderate pressures (less than 1 GPa), with planetologically significant implications, including the possibility of layering in Titan's magma ocean.

Labeled drawing of Jupiter showing its core and composition

NASA Technical Reports Server (NTRS)

1989-01-01

Labeled drawing of Jupiter identifies fluid molecular hydrogen, transition zone, fluid metallic hydrogen, and possible core and the composition of its atmosphere - cloud tops - aerosols, ammonia crystals, ammonium hydrosulfide clouds, ice crystal clouds, and water droplets.

Comparison between the summed difference score and myocardial blood flow measured by 13N-ammonia.

PubMed

Giubbini, Raffaele; Peli, Alessia; Milan, Elisa; Sciagrà, Roberto; Camoni, Luca; Albano, Domenico; Bertoli, Mattia; Bonacina, Mattia; Motta, Federica; Statuto, Massimo; Rodella, Carlo Alberto; De Agostini, Antonio; Calabretta, Raffaella; Bertagna, Francesco

2017-02-03

Both the myocardial perfusion pattern and myocardial blood flow (MBF) are used to assess patients with suspected coronary artery disease (CAD). The aim of this study was to compare the perfusion pattern (using the summed difference score [SDS]) to MBF in a consecutive group of patients undergoing PET/CT with 13 N-ammonia ( 13 NH 3 ). 47 consecutive patients, aged 65 ± 12 years (42 men) with known or suspected CAD, underwent vasodilator stress/rest PET/CT with 13 NH 3 for clinical indications. The SDS was determined by a commercially available software based on a 17-segment model. MBF was measured at rest and during hyperemia by dynamic acquisition and single-compartment model analysis. From the rest and stress MBF, the absolute difference (stress-rest) in myocardial blood flow defined as difference in myocardial blood flow (DMBF) was derived. There were no significant differences between patients with no ischemia (SDS ≤ 1) and those with ischemia (SDS > 1) in CFR (2.84 ± 0.73 vs 2.63 ± 0.89, P = NS) and DMBF (1.34 ± 0.45 vs 1.24 ± 0.53 mL·minute -1 ·g -1 , P = NS). There were however significant regional differences (141 different vascular territories in 47 patients) between these two groups (CFR: 2.84 ± 0.95 vs 2.16 ± 0.57, P < .001 and DMBF: 1.39 ± 0.6 vs 0.87 ± 0.39, P < .0001). The correlation between regional CFR and regional DMBF with SDS was significant (y = 2.7145e -0.059x R = 0.358 and y = 1.2769e -0.119x R = 0.44) CONCLUSION: The SDS is the difference between two measurements (stress-rest) and it correlates better with regional DMBF, which is another measurement that reflects the difference between stress and rest. The correlation is better on regional than global basis.

Cardiac PET perfusion tracers: current status and future directions.

PubMed

Maddahi, Jamshid; Packard, René R S

2014-09-01

PET myocardial perfusion imaging (MPI) is increasingly being used for noninvasive detection and evaluation of coronary artery disease. However, the widespread use of PET MPI has been limited by the shortcomings of the current PET perfusion tracers. The availability of these tracers is limited by the need for an onsite ((15)O water and (13)N ammonia) or nearby ((13)N ammonia) cyclotron or commitment to costly generators ((82)Rb). Owing to the short half-lives, such as 76 seconds for (82)Rb, 2.06 minutes for (15)O water, and 9.96 minutes for (13)N ammonia, their use in conjunction with treadmill exercise stress testing is either not possible ((82)Rb and (15)O water) or not practical ((13)N ammonia). Furthermore, the long positron range of (82)Rb makes image resolution suboptimal and its low myocardial extraction limits its defect resolution. In recent years, development of an (18)F-labeled PET perfusion tracer has gathered considerable interest. The longer half-life of (18)F (109 minutes) would make the tracer available as a unit dose from regional cyclotrons and allow use in conjunction with treadmill exercise testing. Furthermore, the short positron range of (18)F would result in better image resolution. Flurpiridaz F 18 is by far the most thoroughly studied in animal models and is the only (18)F-based PET MPI radiotracer currently undergoing clinical evaluation. Preclinical and clinical experience with Flurpiridaz F 18 demonstrated a high myocardial extraction fraction, high image and defect resolution, high myocardial uptake, slow myocardial clearance, and high myocardial-to-background contrast that was stable over time-important properties of an ideal PET MPI radiotracer. Preclinical data from other (18)F-labeled myocardial perfusion tracers are encouraging. Copyright © 2014. Published by Elsevier Inc.

Species, Abundance and Function of Ammonia-oxidizing Archaea in Inland Waters across China

NASA Astrophysics Data System (ADS)

Zhou, Leiliu; Wang, Shanyun; Zou, Yuxuan; Xia, Chao; Zhu, Guibing

2015-11-01

Ammonia oxidation is the first step in nitrification and was thought to be performed solely by specialized bacteria. The discovery of ammonia-oxidizing archaea (AOA) changed this view. We examined the large scale and spatio-temporal occurrence, abundance and role of AOA throughout Chinese inland waters (n = 28). Molecular survey showed that AOA was ubiquitous in inland waters. The existence of AOA in extreme acidic, alkaline, hot, cold, eutrophic and oligotrophic environments expanded the tolerance limits of AOA, especially their known temperature tolerance to -25 °C, and substrate load to 42.04 mM. There were spatio-temporal divergences of AOA community structure in inland waters, and the diversity of AOA in inland water ecosystems was high with 34 observed species-level operational taxonomic units (OTUs; based on a 15% cutoff) distributed widely in group I.1b, I.1a, and I.1a-associated. The abundance of AOA was quite high (8.5 × 104 to 8.5 × 109 copies g-1), and AOA outnumbered ammonia-oxidizing bacteria (AOB) in the inland waters where little human activities were involved. On the whole AOB predominate the ammonia oxidation rate over AOA in inland water ecosystems, and AOA play an indispensable role in global nitrogen cycle considering that AOA occupy a broader habitat range than AOB, especially in extreme environments.

Trapping in water - an important prerequisite for complex reactivity in astrophysical ices: the case of acetone (CH3)2C = O and ammonia NH3

NASA Astrophysics Data System (ADS)

Fresneau, Aurélien; Danger, Grégoire; Rimola, Albert; Theule, Patrice; Duvernay, Fabrice; Chiavassa, Thierry

2014-10-01

Water is the most abundant compound in interstellar and cometary ices. Laboratory experiments on ice analogues have shown that water has a great influence on the chemical activity of these ices. In this study, we investigated the reactivity of acetone-ammonia ices, showing that water is an essential component in chemical reactions with high activation energies. In a water-free binary ice, acetone and ammonia do not react due to high activation energy, as the reactants desorb before reacting (at 120 and 140 K, respectively). By contrast, our study shows that under experimental conditions of ˜150 K, this reaction does occur in the presence of water. Here, water traps reactants in the solid phase above their desorption temperatures, allowing them to gather thermal energy as the reaction proceeds. Using infrared spectroscopy and mass spectrometry associated with isotopic labelling, as well as quantum chemical calculations, 2-aminopropan-2-ol (2HN-C(CH3)2-OH) was identified as the acetone-ammonia reaction product. The formation of this product may represent the first step towards formation of 2-aminoisobutyric acid (AIB) in the Strecker synthesis. The activation energy for the formation of 2-aminopropan-2-ol was measured to be 42 ± 3 kJ mol-1, while its desorption energy equalled 61.3 ± 0.1 kJ mol-1. Our work demonstrates that astrophysical water, rather than being a non-thermally reactive species, is crucial for the evolution of complex chemistry occurring in the Universe.

Multi-Isotope Secondary Ion Mass Spectrometry Combining Heavy Water 2H with 15N Labeling As Complementary Tracers for Metabolic Heterogeneity at the Single-Cell Level

NASA Astrophysics Data System (ADS)

Kopf, S.; McGlynn, S.; Cowley, E.; Green, A.; Newman, D. K.; Orphan, V. J.

2014-12-01

Metabolic rates of microbial communities constitute a key physiological parameter for understanding the in situ growth constraints for life in any environment. Isotope labeling techniques provide a powerful approach for measuring such biological activity, due to the use of isotopically enriched substrate tracers whose incorporation into biological materials can be detected with high sensitivity by isotope-ratio mass spectrometry. Nano-meter scale secondary ion mass spectrometry (NanoSIMS) combined with stable isotope labeling provides a unique tool for studying the spatiometabolic activity of microbial populations at the single cell level in order to assess both community structure and population diversity. However, assessing the distribution and range of microbial activity in complex environmental systems with slow-growing organisms, diverse carbon and nitrogen sources, or heterotrophic subpopulations poses a tremendous technical challenge because the introduction of isotopically labeled substrates frequently changes the nutrient availability and can inflate or bias measures of activity. Here, we present the use of hydrogen isotope labeling with deuterated water as an important new addition to the isotopic toolkit and apply it for the determination of single cell microbial activities by NanoSIMS imaging. This tool provides a labeling technique that minimally alters any aquatic chemical environment, can be administered with strong labels even in minimal addition (natural background is very low), is an equally universal substrate for all forms of life even in complex, carbon and nitrogen saturated systems, and can be combined with other isotopic tracers. The combination of heavy water labeling with the most commonly used NanoSIMS tracer, 15N, is technically challenging but opens up a powerful new set of multi-tracer experiments for the study of microbial activity in complex communities. We present the first truly simultaneous single cell triple isotope system

Assessment of Nitrification in Distribution Systems of Waters with Elevated Ammonia Levels

EPA Science Inventory

The objective of this work is to monitor ammonia, nitrite, and nitrate in drinking water from the distribution systems of four drinking water utilities in Illinois. A monthly drinking water distribution system water quality monitoring protocol for each water utility in Illinois h...

Distribution and recovery of nitrogen-15-labeled liquid anhydrous ammonia among various soil fractions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norman, R.J.; Kurtz, L.T.; Stevenson, F.J.

Since liquid anhydrous ammonia (LAA) is a major N fertilizer, information was sought about the proportions of LAA that enter into various combinations in soils. Liquid anhydrous NH/sub 3/, labeled with /sup 15/N was injected into three soils (Drummer, Typic Haplaquoll; Blount, Aeric Ochraqualf; Cisne, Mollic Albaqualf) in the laboratory at a rate equivalent to a field application of 206 kg N ha /sup 1/ in 76.2 cm knife-spacings. At 1, 7, 14, 28, 56, and 112 d after application, fertilizer N present in different soil fractions was determined in five concentric zones with radii of 0 to 1.5, 1.5more » to 3.0, 3.0 to 4.5, 4.5 to 6.0, and 6.0 to 7.0 cm around the point of application. Depending on the soil, from 68 to 83% of the applied /sup 15/N was accounted for as (exchangeable NH/sub 4//sup +/ + NO/sub 3//sup -/ + NO/sub 2//sup -/)-N by the 112th day following application, the remainder being accounted for as clay-fixed NH/sub 4//sup +/ (1.9-4.9%), organic matter-fixed NH/sub 3/ (4.0-6.0%), and biologically immobilized organic N (3.9-9.3%). From 50 to 70% of the organic matter-fixed NH/sub 3/-N was released by hydrolysis with dilute KOH solution as compared to 10 to 15% for the immobilized N. Total recovery of /sup 15/N at 112 d ranged from 77% for the Cisne soil to about 97% for the Drummer and Blount soils. Lateral distributions and transformations of NH/sub 4//sup +/ and NO/sub 3//sup -/ and pH trends after LAA applications were similar to those reported by previous investigators.« less

From Earth to Space: Application of Biological Treatment for the Removal of Ammonia from Water

NASA Technical Reports Server (NTRS)

Ghosh, Amlan; Seidel, Chad; Adam, Niklas; Pickering, Karen; White, Dawn

2014-01-01

Managing ammonia is often a challenge in both drinking water and wastewater treatment facilities. Ammonia is unregulated in drinking water, but its presence may result in numerous water quality issues in the distribution system such as loss of residual disinfectant, nitrification, and corrosion. Ammonia concentrations need to be managed in wastewater effluent to sustain the health of receiving water bodies. Biological treatment involves the microbiological oxidation of ammonia to nitrate through a two-step process. While nitrification is common in the environment, and nitrifying bacteria can grow rapidly on filtration media, appropriate conditions, such as the presence of dissolved oxygen and required nutrients, need to be established. This presentation will highlight results from two ongoing research programs - one at NASA's Johnson Space Center, and the other at a drinking water facility in California. Both programs are designed to demonstrate nitrification through biological treatment. The objective of NASA's research is to be able to recycle wastewater to potable water for spaceflight mission. To this end, a biological water processor (BWP) has been integrated with a forward osmosis secondary treatment system (FOST). Bacteria mineralize organic carbon to carbon dioxide as well as ammonia-nitrogen present in the wastewater to nitrogen gas, through a combination of nitrification and denitrification. The effluent from the BWP system is low in organic contaminants, but high in total dissolved solids. The FOST system, integrated downstream of the BWP, removes dissolved solids through a combination of concentration-driven forward osmosis and pressure driven reverse osmosis. The integrated system testing planned for this year is expected to produce water that requires only a polishing step to meet potable water requirements for spaceflight. The pilot study in California is being conducted on Golden State Water Company's Yukon wellsthat have hydrogen sulfide odor

From Earth to Space: Application of Biological Treatment for the Removal of Ammonia from Water

NASA Technical Reports Server (NTRS)

Pickering, Karen; Adam, Niklas; White, Dawn; Ghosh, Amlan; Seidel, Chad

2014-01-01

Managing ammonia is often a challenge in both drinking water and wastewater treatment facilities. Ammonia is unregulated in drinking water, but its presence may result in numerous water quality issues in the distribution system such as loss of residual disinfectant, nitrification, and corrosion. Ammonia concentrations need to be managed in wastewater effluent to sustain the health of receiving water bodies. Biological treatment involves the microbiological oxidation of ammonia to nitrate through a two-step process. While nitrification is common in the environment, and nitrifying bacteria can grow rapidly on filtration media, appropriate conditions, such as the presence of dissolved oxygen and required nutrients, need to be established. This presentation will highlight results from two ongoing research programs - one at NASA's Johnson Space Center, and the other at a drinking water facility in California. Both programs are designed to demonstrate nitrification through biological treatment. The objective of NASA's research is to be able to recycle wastewater to potable water for spaceflight missions. To this end, a biological water processor (BWP) has been integrated with a forward osmosis secondary treatment system (FOST). Bacteria mineralize organic carbon to carbon dioxide as well as ammonia-nitrogen present in the wastewater to nitrogen gas, through a combination of nitrification and denitrification. The effluent from the BWP system is low in organic contaminants, but high in total dissolved solids. The FOST system, integrated downstream of the BWP, removes dissolved solids through a combination of concentration-driven forward osmosis and pressure driven reverse osmosis. The integrated system testing planned for this year is expected to produce water that requires only a polishing step to meet potable water requirements for spaceflight. The pilot study in California is being conducted on Golden State Water Company's Yukon wells that have hydrogen sulfide odor

Species, Abundance and Function of Ammonia-oxidizing Archaea in Inland Waters across China

PubMed Central

Zhou, Leiliu; Wang, Shanyun; Zou, Yuxuan; Xia, Chao; Zhu, Guibing

2015-01-01

Ammonia oxidation is the first step in nitrification and was thought to be performed solely by specialized bacteria. The discovery of ammonia-oxidizing archaea (AOA) changed this view. We examined the large scale and spatio-temporal occurrence, abundance and role of AOA throughout Chinese inland waters (n = 28). Molecular survey showed that AOA was ubiquitous in inland waters. The existence of AOA in extreme acidic, alkaline, hot, cold, eutrophic and oligotrophic environments expanded the tolerance limits of AOA, especially their known temperature tolerance to −25 °C, and substrate load to 42.04 mM. There were spatio-temporal divergences of AOA community structure in inland waters, and the diversity of AOA in inland water ecosystems was high with 34 observed species-level operational taxonomic units (OTUs; based on a 15% cutoff) distributed widely in group I.1b, I.1a, and I.1a-associated. The abundance of AOA was quite high (8.5 × 104 to 8.5 × 109 copies g−1), and AOA outnumbered ammonia-oxidizing bacteria (AOB) in the inland waters where little human activities were involved. On the whole AOB predominate the ammonia oxidation rate over AOA in inland water ecosystems, and AOA play an indispensable role in global nitrogen cycle considering that AOA occupy a broader habitat range than AOB, especially in extreme environments. PMID:26522086

Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tolar, Bradley B.; Herrmann, Jonathan; Bargar, John R.

In this paper, knowledge of the molecular ecology and environmental determinants of ammonia-oxidizing organisms is critical to understanding and predicting the global nitrogen (N) and carbon cycles, but an incomplete biochemical picture hinders in vitro studies of N-cycling enzymes. Although an integrative structural and dynamic characterization at the atomic scale would advance our understanding of function tremendously, structural knowlede of key N-cycling enzymes from ecologically-relevant ammonia oxidizers is unfortunately extremely limited. Here, we discuss the challenges and opportunities for examining the ecology of ammonia-oxidizing organisms, particularly uncultivated Thaumarchaeota, though (meta)genome-driven structural biology of the enzymes ammonia monooxygenase (AMO) andmore » nitrite reductase (NirK).« less

Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea

DOE PAGES

Tolar, Bradley B.; Herrmann, Jonathan; Bargar, John R.; ...

2017-07-05

In this paper, knowledge of the molecular ecology and environmental determinants of ammonia-oxidizing organisms is critical to understanding and predicting the global nitrogen (N) and carbon cycles, but an incomplete biochemical picture hinders in vitro studies of N-cycling enzymes. Although an integrative structural and dynamic characterization at the atomic scale would advance our understanding of function tremendously, structural knowlede of key N-cycling enzymes from ecologically-relevant ammonia oxidizers is unfortunately extremely limited. Here, we discuss the challenges and opportunities for examining the ecology of ammonia-oxidizing organisms, particularly uncultivated Thaumarchaeota, though (meta)genome-driven structural biology of the enzymes ammonia monooxygenase (AMO) andmore » nitrite reductase (NirK).« less

Integrated structural biology and molecular ecology of N-cycling enzymes from ammonia-oxidizing archaea.

PubMed

Tolar, Bradley B; Herrmann, Jonathan; Bargar, John R; van den Bedem, Henry; Wakatsuki, Soichi; Francis, Christopher A

2017-10-01

Knowledge of the molecular ecology and environmental determinants of ammonia-oxidizing organisms is critical to understanding and predicting the global nitrogen (N) and carbon cycles, but an incomplete biochemical picture hinders in vitro studies of N-cycling enzymes. Although an integrative structural and dynamic characterization at the atomic scale would advance our understanding of function tremendously, structural knowledge of key N-cycling enzymes from ecologically relevant ammonia oxidizers is unfortunately extremely limited. Here, we discuss the challenges and opportunities for examining the ecology of ammonia-oxidizing organisms, particularly uncultivated Thaumarchaeota, through (meta)genome-driven structural biology of the enzymes ammonia monooxygenase (AMO) and nitrite reductase (NirK). © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

The fate of (13)C-labelled and non-labelled inulin predisposed to large bowel fermentation in rats.

PubMed

Butts, Christine A; Paturi, Gunaranjan; Tavendale, Michael H; Hedderley, Duncan; Stoklosinski, Halina M; Herath, Thanuja D; Rosendale, Douglas; Roy, Nicole C; Monro, John A; Ansell, Juliet

2016-04-01

The fate of stable-isotope (13)C labelled and non-labelled inulin catabolism by the gut microbiota was assessed in a healthy rat model. Sprague-Dawley male rats were randomly assigned to diets containing either cellulose or inulin, and were fed these diets for 3 days. On day (d) 4, rats allocated to the inulin diet received (13)C-labelled inulin. The rats were then fed the respective non-labelled diets (cellulose or inulin) until sampling (d4, d5, d6, d7, d10 and d11). Post feeding of (13)C-labelled substrate, breath analysis showed that (13)C-inulin cleared from the host within a period of 36 hours. Faecal (13)C demonstrated the clearance of inulin from gut with a (13)C excess reaching maximum at 24 hours (d5) and then declining gradually. There were greater variations in caecal organic acid concentrations from d4 to d6, with higher concentrations of acetic, butyric and propionic acids observed in the rats fed inulin compared to those fed cellulose. Inulin influenced caecal microbial glycosidase activity, increased colon crypt depth, and decreased the faecal output and polysaccharide content compared to the cellulose diet. In summary, the presence of inulin in the diet positively influenced large bowel microbial fermentation.

Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C, 15N-labeled peptides and proteins

NASA Astrophysics Data System (ADS)

Janik, Rafal; Ritz, Emily; Gravelle, Andrew; Shi, Lichi; Peng, Xiaohu; Ladizhansky, Vladimir

2010-03-01

In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly 13C, 15N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22 kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600 MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i - 2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed.

Poly(N-vinyl-2-pyrrolidone)-stabilized palladium-platinum nanoparticles-catalyzed hydrolysis of ammonia borane for hydrogen generation

NASA Astrophysics Data System (ADS)

Rakap, Murat

2015-02-01

The catalytic use of highly efficient poly(N-vinyl-2-pyrrolidone)-stabilized palladium-platinum nanoparticles (4.2 ± 1.9 nm) in the hydrolysis of ammonia-borane is reported. The catalyst is prepared by co-reduction of two metal ions in ethanol/water mixture by an alcohol reduction method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and UV-Vis spectroscopy. They are recyclable and highly active for hydrogen generation from the hydrolysis of ammonia-borane even at very low concentrations and temperature, providing a record numbers of average turnover frequency value (125 mol H2/mol cat.min-1) and maximum hydrogen generation rate (3468 L H2 min-1 (mol cat)-1). They also provide activation energy of 51.7 ± 2 kJ/mol for the hydrolysis of ammonia borane.

The reduction of nitric oxide by ammonia over polycrystalline platinum model catalysts in the presence of oxygen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katona, T.; Guczi, L.; Somorjai, G.A.

1992-06-01

The reaction system of nitric oxide, ammonia, and oxygen was studied using batch-mode measurements in partial pressure ranges of 65-1000 Pa (0.5-7.6 Torr) on polycrystalline Pt foils over the temperature range 423-598 K. Under these conditions the oxidation of nitric oxide was not detectable. The ammonia oxidation reaction, using dioxygen, occurred in the temperature range 423-493 K, producing nitrogen and water as the only products. The activation energy of the nitrogen formation was found to be 86 kJ/mol. Above this temperature range, flow-mode measurements showed the formation of both nitrous oxide and nitric oxide. The reaction rate between ammonia andmore » oxygen was greatly decreased (about a factor of 10) by nitric oxide, while the reaction rate between nitric oxide and ammonia was accelerated (about 10-fold) due to the presence of oxygen. Nitric oxide reduction by ammonia in the presence of oxygen occurred in the temperature range 423-598 K. The products of the reaction were nitrogen, oxygen nitrous oxide, and water. The Arrhenius plot of the reaction showed a break near 523 K. Below this temperature the activation energy of the reaction was 13 kJ/mol, and in the higher-temperature range it was 62 kJ/mol. At 473 K, the N[sub 2]/N[sub 2]O ratio was about 0.6 and O[sub 2] formation was also monitored. At 573 K, the N[sub 2]N[sub 2]O ratio was approximately 2 and oxygen was consumed in the course of the reaction as well.« less

Cells for bioartificial liver devices: the human hepatoma-derived cell line C3A produces urea but does not detoxify ammonia.

PubMed

Mavri-Damelin, Demetra; Damelin, Leonard H; Eaton, Simon; Rees, Myrddin; Selden, Clare; Hodgson, Humphrey J F

2008-02-15

Extrahepatic bioartificial liver devices should provide an intact urea cycle to detoxify ammonia. The C3A cell line, a subclone of the hepatoma-derived HepG2 cell line, is currently used in this context as it produces urea, and this has been assumed to be reflective of ammonia detoxification via a functional urea cycle. However, based on our previous findings of perturbed urea-cycle function in the non-urea producing HepG2 cell line, we hypothesized that the urea produced by C3A cells was via a urea cycle-independent mechanism, namely, due to arginase II activity, and therefore would not detoxify ammonia. Urea was quantified using (15)N-ammonium chloride metabolic labelling with gas chromatography-mass spectrometry. Gene expression was determined by real-time reverse transcriptase-PCR, protein expression by western blotting, and functional activities with radiolabelling enzyme assays. Arginase inhibition studies used N(omega)-hydroxy-nor-L-arginine. Urea was detected in C3A conditioned medium; however, (15)N-ammonium chloride-labelling indicated that (15)N-ammonia was not incorporated into (15)N-labelled urea. Further, gene expression of two urea cycle genes, ornithine transcarbamylase and arginase I, were completely absent. In contrast, arginase II mRNA and protein was expressed at high levels in C3A cells and was inhibited by N(omega)-hydroxy-nor-L-arginine, which prevented urea production, thereby indicating a urea cycle-independent pathway. The urea cycle is non-functional in C3A cells, and their urea production is solely due to the presence of arginase II, which therefore cannot provide ammonia detoxification in a bioartificial liver system. This emphasizes the continued requirement for developing a component capable of a full repertoire of liver function. (c) 2007 Wiley Periodicals, Inc.

Oxidation of ammonia and methane in an alkaline, saline lake

USGS Publications Warehouse

Joye, S.B.; Connell, T.L.; Miller, L.G.; Oremland, R.S.; Jellison, R.S.

1999-01-01

The oxidation of ammonia (NH3) and methane (CH4) was investigated in an alkaline saline lake, Mono Lake, California (U.S.A.). Ammonia oxidation was examined in April and July 1995 by comparing dark 14CO2 fixation rates in the presence or absence of methyl fluoride (MeF), an inhibitor of NH3 oxidation. Ammonia oxidizer-mediated dark 14CO2 fixation rates were similar in surface (5-7 m) and oxycline (11-15 m) waters, ranging between 70-340 and 89-186 nM d-1, respectively, or 1-7% of primary production by phytoplankton. Ammonia oxidation rates ranged between 580-2,830 nM d-1 in surface waters and 732-1,548 nM d-1 in oxycline waters. Methane oxidation was examined using a 14CH4 tracer technique in July 1994, April 1995, and July 1995. Methane oxidation rates were consistently higher in July, and rates in oxycline and anaerobic bottom waters (0.5-37 and 7-48 nM d-1, respectively) were 10-fold higher than those in aerobic surface waters (0.04-3.8 nM d-1). The majority of CH4 oxidation, in terms of integrated activity, occurred within anoxic bottom waters. Water column oxidation reduced the potential lake-atmosphere CH4 flux by a factor of two to three. Measured oxidation rates and water column concentrations were used to estimate the biological turnover times of NH3 and CH4. The NH3 pool turns over rapidly, on time scales of 0.8 d in surface waters and 10 d within the oxycline, while CH4 is cycled on 103-d time scales in surface waters and 102-d time scales within oxycline and bottom waters. Our data suggest an important role for NH3 oxidation in alkaline, saline lakes since the process converts volatile NH3 to soluble NO2-, thereby reducing loss via lake-atmosphere exchange and maintaining nitrogen in a form that is readily available to phytoplankton.

Isotopic analyses of nitrogenous compounds from the Murchison meteorite: ammonia, amines, amino acids, and polar hydrocarbons

NASA Technical Reports Server (NTRS)

Pizzarello, S.; Feng, X.; Epstein, S.; Cronin, J. R.

1994-01-01

The combined volatile bases (ammonia, aliphatic amines, and possibly other bases), ammonia, amino acids, and polar hydrocarbons were prepared from the Murchison meteorite for isotopic analyses. The volatile bases were obtained by cryogenic transfer after acid-hydrolysis of a hot-water extract and analyzed by combined gas chromatography-mass spectrometry of pentafluoropropionyl derivatives. The aliphatic amines present in this preparation comprise a mixture that includes both primary and secondary isomers through C5 at a total concentration of > or = 100 nmoles g-1. As commonly observed for meteoritic organic compounds, almost all isomers through C5 are present, and the concentrations within homologous series decrease with increasing chain length. Ammonia was chromatographically separated from the other volatile bases and found at a concentration of 1.1-1.3 micromoles g-1 meteorite. The ammonia analyzed includes contributions from ammonium salts and the hydrolysis of extractable organic compounds, e.g., carboxamides. Stable isotope analyses showed the volatile bases to be substantially enriched in the heavier isotopes, relative to comparable terrestrial compounds delta D < or = +1221%; delta 13C = +22%; delta 15N = +93%). Ammonia, per se, was found to have a somewhat lower delta 15N value (+69%) than the total volatile bases; consequently, a higher delta 15N (>93%) can be inferred for the other bases, which include the amines. Solvent-extractable polar hydrocarbons obtained separately were found to be enriched in 15N (delta 15N = +104%). Total amino acids, prepared from a hydrolyzed hot-water extract by cation exchange chromatography, gave a delta 15N of +94%, a value in good agreement with that obtained previously. Nitrogen isotopic data are also given for amino acid fractions separated chromatographically. The delta 15N values of the Murchison soluble organic compounds analyzed to date fall within a rather narrow range (delta 15N = +94 +/- 8%), an observation

Conformational Properties, Spectroscopy and Structure of ISATIN-(WATER)_{n=1-3} Clusters

NASA Astrophysics Data System (ADS)

Singh, Milind K.; Upadhya, D. M.; Singh, Vipin B.

2009-06-01

The structure, stability and vibrational characteristics of Isatin-(Water)_n clusters with n=1=3 have been investigated using second order Moller-Plesset (MP2) perturbation tehory and Density Functional Theory (with B3LYP) methods employing the basis set 6-31+G(d). The vertical excitation energies for these complexes have been also computed using the time-dependent density functional theory. The three stable conformational isomers, each for Isatin-(Water)_1 and Isatin-(Water)_2 clusters were obtained. It is shown that in the most stable isomer of Isatin-(Water)_1 cluster hydrogen bond between amide hydrogen and oxygen of water is found stronger as compared to the H-bond in Indole-(Water)_1 cluster. For a particular position of complexation of water, between the carbonyl oxygen's, results an unusual increase in the dipole moment due to an electronic charge displacement from the N atom to the C atom of the neighboring carbonyl bond. This causes a large separation between the effective charges forming the dipole. The complexes involving this position of water are expected to show a small charge transfer character. The experimentally observed electronic absorption peaks are reasonably reproduced by the TD-DFT calculations and it is found that the longest wavelength absorption peak of isatin at 406 nm is significantly red shifted after addition of a water molecule.

[Mitigation effect of several controlled-release N fertilizers on ammonia volatilization and related affecting factors].

PubMed

Sun, Kejun; Mao, Xiaoyun; Lu, Qiming; Jia, Aiping; Liao, Zongwen

2004-12-01

By using static absorption and soil column leaching methods, this paper studied the behaviors of several controlled-release N fertilizers in soil under laboratory conditions. The results showed that under the application rate of 450 mg x kg(-1), total ammonia volatilization from three controlled-release fertilizers decreased by 49.7%, 28.0% and 71.2%, respectively, in comparing with common urea. When the application rate was 600 mg x kg(-1), total ammonia volatilization decreased by 34.6%, 12.3%, 69.9%, respectively. Controlled-release fertilizers could markedly reduce total ammonia volatilization from soil and decrease environment pollution via fertilization. The results also indicated that total ammonia volatilization correlated significantly with soil urease activity, pH value and N leaching rate. The correlation coefficient between total ammonia volatilization and accumulated N leaching rate was 0.9533, and that between total ammonia volatilization and soil urease activity and pH value was 0.9533 and 0.9908, respectively.

Pharmacokinetics of stable isotopically labeled L-histidine in humans and the assessment of in vivo histidine ammonia lyase activities.

PubMed

Furuta, T; Okamiya, K; Shibasaki, H; Kasuya, Y

1996-01-01

The pharmacokinetics of L-histidine in humans has been investigated to evaluate the in vivo histidine ammonia lyase system for the conversion of L-histidine to urocanic acid. Two healthy volunteers (subjects A and B) received a single 100-mg oral dose of L-[3,3-2H2,1',3'-15N2]histidine. Blood and urine samples were obtained over 24 hr after the administration and analyzed by stable isotope dilution ms. Labeled L-histidine was rapidly absorbed, and a maximum plasma concentration of L-histidine was observed at 30 min (1057.6 ng/ml) in subject A and at 60 min (1635.6 ng/ml) in subject B after oral administration. Pharmacokinetic parameters were calculated based on a two-compartment model. Labeled L-histidine in subject A (t1/2 = 1.0 hr) was eliminated approximately twice faster than that in subject B (t1/2 = 1.9 hr). Total body clearances were 70.0 liters/hr in subject A and 30.0 liters/hr in subject B. The low ratios of the renal clearance to the total body clearance (1.04% for subject A and 0.43% for subject B) indicated that most of L-histidine was eliminated via the nonrenal processes. L-Histidine was rapidly metabolized to urocanic acid. Maximum plasma concentrations of urocanic acid were 59.61 ng/ml at 30 min for subject A and 46.10 ng/ml at 60 min for subject B. The slope of the plot of urinary excretion rate of urocanic acid vs. the plasma concentration of unchanged L-histidine was demonstrated to reflect the metabolic clearance of L-histidine to urocanic acid. The method of evaluating the in vivo human histidine ammonia lyase activities discussed in this study offers a significant value with regard to the biochemical and clinical elucidations of the heterogeneity of histidinemia.

ENGINEERING DESIGN CONFIGURATIONS FOR BIOLOGICAL AMMONIA REMOVAL

EPA Science Inventory

Many regions in the United States have excessive levels of nutrients including ammonia in their source waters. For example, farming and agricultural sources of ammonia in the Midwest contribute to relatively high levels of ammonia in many ground waters. Although ammonia in water ...

High Pressure Cosmochemistry of Major Planetary Interiors: Laboratory Studies of the Water-rich Region of the System Ammonia-water

NASA Technical Reports Server (NTRS)

Nicol, M.; Johnson, M.; Koumvakalis, A. S.

1985-01-01

The behavior of gas-ice mixtures in major planets at very high pressures was studied. Some relevant pressure-temperature-composition (P-T-X) regions of the hydrogen (H2)-helium (He)-water (H2O-ammonia (NH3)-methane (CH4) phase diagram were determined. The studies, and theoretical model, of the relevant phases, are needed to interpret the compositions of ice-gas systems at conditions of planetary interest. The compositions and structures of a multiphase, multicomponent system at very high pressures care characterized, and the goal is to characterize this system over a wide range of low and high temperatures. The NH3-H2O compositions that are relevant to planetary problems yet are easy to prepare were applied. The P-T surface of water was examined and the corresponding surface for NH3 was determined. The T-X diagram of ammonia-water at atmospheric pressure was studied and two water-rich phases were found, NH3-2H2O (ammonia dihydrate), which melts incongruently, and NH3.H2O (ammonia monohydrate), which is nonstoichiometric and melts at a higher temperature than the dihydrate. It is suggested that a P-T surface at approximately the monohydrate composition and the P-X surface at room temperature is determined.

Low-temperature conversion of ammonia to nitrogen in water with ozone over composite metal oxide catalyst.

PubMed

Chen, Yunnen; Wu, Ye; Liu, Chen; Guo, Lin; Nie, Jinxia; Chen, Yu; Qiu, Tingsheng

2018-04-01

As one of the most important water pollutants, ammonia nitrogen emissions have increased year by year, which has attracted people's attention. Catalytic ozonation technology, which involves production of ·OH radical with strong oxidation ability, is widely used in the treatment of organic-containing wastewater. In this work, MgO-Co 3 O 4 composite metal oxide catalysts prepared with different fabrication conditions have been systematically evaluated and compared in the catalytic ozonation of ammonia (50mg/L) in water. In terms of high catalytic activity in ammonia decomposition and high selectivity for gaseous nitrogen, the catalyst with MgO-Co 3 O 4 molar ratio 8:2, calcined at 500°C for 3hr, was the best one among the catalysts we tested, with an ammonia nitrogen removal rate of 85.2% and gaseous nitrogen selectivity of 44.8%. In addition, the reaction mechanism of ozonation oxidative decomposition of ammonia nitrogen in water with the metal oxide catalysts was discussed. Moreover, the effect of coexisting anions on the degradation of ammonia was studied, finding that SO 4 2- and HCO 3 - could inhibit the catalytic activity while CO 3 2- and Br - could promote it. The presence of coexisting cations had very little effect on the catalytic ozonation of ammonia nitrogen. After five successive reuses, the catalyst remained stable in the catalytic ozonation of ammonia. Copyright © 2017. Published by Elsevier B.V.

Differential contributions of ammonia oxidizers and nitrite oxidizers to nitrification in four paddy soils

PubMed Central

Wang, Baozhan; Zhao, Jun; Guo, Zhiying; Ma, Jing; Xu, Hua; Jia, Zhongjun

2015-01-01

Rice paddy fields are characterized by regular flooding and nitrogen fertilization, but the functional importance of aerobic ammonia oxidizers and nitrite oxidizers under unique agricultural management is poorly understood. In this study, we report the differential contributions of ammonia-oxidizing archaea (AOA), bacteria (AOB) and nitrite-oxidizing bacteria (NOB) to nitrification in four paddy soils from different geographic regions (Zi-Yang (ZY), Jiang-Du (JD), Lei-Zhou (LZ) and Jia-Xing (JX)) that are representative of the rice ecosystems in China. In urea-amended microcosms, nitrification activity varied greatly with 11.9, 9.46, 3.03 and 1.43 μg NO3−-N g−1 dry weight of soil per day in the ZY, JD, LZ and JX soils, respectively, over the course of a 56-day incubation period. Real-time quantitative PCR of amoA genes and pyrosequencing of 16S rRNA genes revealed significant increases in the AOA population to various extents, suggesting that their relative contributions to ammonia oxidation activity decreased from ZY to JD to LZ. The opposite trend was observed for AOB, and the JX soil stimulated only the AOB populations. DNA-based stable-isotope probing further demonstrated that active AOA numerically outcompeted their bacterial counterparts by 37.0-, 10.5- and 1.91-fold in 13C-DNA from ZY, JD and LZ soils, respectively, whereas AOB, but not AOA, were labeled in the JX soil during active nitrification. NOB were labeled to a much greater extent than AOA and AOB, and the addition of acetylene completely abolished the assimilation of 13CO2 by nitrifying populations. Phylogenetic analysis suggested that archaeal ammonia oxidation was predominantly catalyzed by soil fosmid 29i4-related AOA within the soil group 1.1b lineage. Nitrosospira cluster 3-like AOB performed most bacterial ammonia oxidation in the ZY, LZ and JX soils, whereas the majority of the 13C-AOB in the JD soil was affiliated with the Nitrosomona communis lineage. The 13C-NOB was overwhelmingly

Differential contributions of ammonia oxidizers and nitrite oxidizers to nitrification in four paddy soils.

PubMed

Wang, Baozhan; Zhao, Jun; Guo, Zhiying; Ma, Jing; Xu, Hua; Jia, Zhongjun

2015-05-01

Rice paddy fields are characterized by regular flooding and nitrogen fertilization, but the functional importance of aerobic ammonia oxidizers and nitrite oxidizers under unique agricultural management is poorly understood. In this study, we report the differential contributions of ammonia-oxidizing archaea (AOA), bacteria (AOB) and nitrite-oxidizing bacteria (NOB) to nitrification in four paddy soils from different geographic regions (Zi-Yang (ZY), Jiang-Du (JD), Lei-Zhou (LZ) and Jia-Xing (JX)) that are representative of the rice ecosystems in China. In urea-amended microcosms, nitrification activity varied greatly with 11.9, 9.46, 3.03 and 1.43 μg NO3(-)-N g(-1) dry weight of soil per day in the ZY, JD, LZ and JX soils, respectively, over the course of a 56-day incubation period. Real-time quantitative PCR of amoA genes and pyrosequencing of 16S rRNA genes revealed significant increases in the AOA population to various extents, suggesting that their relative contributions to ammonia oxidation activity decreased from ZY to JD to LZ. The opposite trend was observed for AOB, and the JX soil stimulated only the AOB populations. DNA-based stable-isotope probing further demonstrated that active AOA numerically outcompeted their bacterial counterparts by 37.0-, 10.5- and 1.91-fold in (13)C-DNA from ZY, JD and LZ soils, respectively, whereas AOB, but not AOA, were labeled in the JX soil during active nitrification. NOB were labeled to a much greater extent than AOA and AOB, and the addition of acetylene completely abolished the assimilation of (13)CO2 by nitrifying populations. Phylogenetic analysis suggested that archaeal ammonia oxidation was predominantly catalyzed by soil fosmid 29i4-related AOA within the soil group 1.1b lineage. Nitrosospira cluster 3-like AOB performed most bacterial ammonia oxidation in the ZY, LZ and JX soils, whereas the majority of the (13)C-AOB in the JD soil was affiliated with the Nitrosomona communis lineage. The (13)C-NOB was

Corrosion protection of steel in ammonia/water heat pumps

DOEpatents

Mansfeld, Florian B.; Sun, Zhaoli

2003-10-14

Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

Innovative ammonia stripping with an electrolyzed water system as pretreatment of thermally hydrolyzed wasted sludge for anaerobic digestion.

PubMed

Park, Seyong; Kim, Moonil

2015-01-01

In this study, the anaerobic digestion of thermally hydrolyzed wasted sludge (THWS) with a high concentration of ammonia was carried out through combining with an ammonia stripping and an electrolyzed water system (EWS). The EWS produced acidic water (pH 2-3) at the anode and alkaline water (pH 11-12) at the cathode with an electro-diaphragm between the electrodes that could be applied to ammonia stripping. The ammonia stripping efficiency was strongly dependent on the pH and aeration rate, and the ammonium ion removal rate followed pseudo-first-order kinetics. From the BMP test, the methane yield of THWS after ammonia stripping using the EWS was 2.8 times higher than that of the control process (raw THWS without ammonia stripping). Furthermore, both methane yield and ammonium removal efficiency were higher in this study than in previous studies. Since ammonia stripping with the EWS does not require any chemicals for pH control, no precipitated sludge is produced and anaerobic microorganisms are not inhibited by cations. Therefore, ammonia stripping using the EWS could be an effective method for digestion of wastewater with a high concentration of ammonium nitrogen.

Nitrogen and Oxygen Isotope Effects of Ammonia Oxidation by Thermophilic Thaumarchaeota from a Geothermal Water Stream

PubMed Central

Sakai, Sanae; Konno, Uta; Nakahara, Nozomi; Takaki, Yoshihiro; Saito, Yumi; Imachi, Hiroyuki; Tasumi, Eiji; Makabe, Akiko; Koba, Keisuke; Takai, Ken

2016-01-01

ABSTRACT Ammonia oxidation regulates the balance of reduced and oxidized nitrogen pools in nature. Although ammonia-oxidizing archaea have been recently recognized to often outnumber ammonia-oxidizing bacteria in various environments, the contribution of ammonia-oxidizing archaea is still uncertain due to difficulties in the in situ quantification of ammonia oxidation activity. Nitrogen and oxygen isotope ratios of nitrite (δ15NNO2− and δ18ONO2−, respectively) are geochemical tracers for evaluating the sources and the in situ rate of nitrite turnover determined from the activities of nitrification and denitrification; however, the isotope ratios of nitrite from archaeal ammonia oxidation have been characterized only for a few marine species. We first report the isotope effects of ammonia oxidation at 70°C by thermophilic Thaumarchaeota populations composed almost entirely of “Candidatus Nitrosocaldus.” The nitrogen isotope effect of ammonia oxidation varied with ambient pH (25‰ to 32‰) and strongly suggests the oxidation of ammonia, not ammonium. The δ18O value of nitrite produced from ammonia oxidation varied with the δ18O value of water in the medium but was lower than the isotopic equilibrium value in water. Because experiments have shown that the half-life of abiotic oxygen isotope exchange between nitrite and water is longer than 33 h at 70°C and pH ≥6.6, the rate of ammonia oxidation by thermophilic Thaumarchaeota could be estimated using δ18ONO2− in geothermal environments, where the biological nitrite turnover is likely faster than 33 h. This study extended the range of application of nitrite isotopes as a geochemical clock of the ammonia oxidation activity to high-temperature environments. IMPORTANCE Because ammonia oxidation is generally the rate-limiting step in nitrification that regulates the balance of reduced and oxidized nitrogen pools in nature, it is important to understand the biological and environmental factors underlying

Nitrogen and Oxygen Isotope Effects of Ammonia Oxidation by Thermophilic Thaumarchaeota from a Geothermal Water Stream.

PubMed

Nishizawa, Manabu; Sakai, Sanae; Konno, Uta; Nakahara, Nozomi; Takaki, Yoshihiro; Saito, Yumi; Imachi, Hiroyuki; Tasumi, Eiji; Makabe, Akiko; Koba, Keisuke; Takai, Ken

2016-08-01

Ammonia oxidation regulates the balance of reduced and oxidized nitrogen pools in nature. Although ammonia-oxidizing archaea have been recently recognized to often outnumber ammonia-oxidizing bacteria in various environments, the contribution of ammonia-oxidizing archaea is still uncertain due to difficulties in the in situ quantification of ammonia oxidation activity. Nitrogen and oxygen isotope ratios of nitrite (δ(15)NNO2- and δ(18)ONO2-, respectively) are geochemical tracers for evaluating the sources and the in situ rate of nitrite turnover determined from the activities of nitrification and denitrification; however, the isotope ratios of nitrite from archaeal ammonia oxidation have been characterized only for a few marine species. We first report the isotope effects of ammonia oxidation at 70°C by thermophilic Thaumarchaeota populations composed almost entirely of "Candidatus Nitrosocaldus." The nitrogen isotope effect of ammonia oxidation varied with ambient pH (25‰ to 32‰) and strongly suggests the oxidation of ammonia, not ammonium. The δ(18)O value of nitrite produced from ammonia oxidation varied with the δ(18)O value of water in the medium but was lower than the isotopic equilibrium value in water. Because experiments have shown that the half-life of abiotic oxygen isotope exchange between nitrite and water is longer than 33 h at 70°C and pH ≥6.6, the rate of ammonia oxidation by thermophilic Thaumarchaeota could be estimated using δ(18)ONO2- in geothermal environments, where the biological nitrite turnover is likely faster than 33 h. This study extended the range of application of nitrite isotopes as a geochemical clock of the ammonia oxidation activity to high-temperature environments. Because ammonia oxidation is generally the rate-limiting step in nitrification that regulates the balance of reduced and oxidized nitrogen pools in nature, it is important to understand the biological and environmental factors underlying the regulation of

16 CFR 1702.13 - Labeling and packaging samples.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Labeling and packaging samples. 1702.13 Section 1702.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION POISON PREVENTION PACKAGING ACT OF 1970 REGULATIONS PETITIONS FOR EXEMPTIONS FROM POISON PREVENTION PACKAGING ACT REQUIREMENTS; PETITION...

16 CFR 1702.13 - Labeling and packaging samples.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Labeling and packaging samples. 1702.13 Section 1702.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION POISON PREVENTION PACKAGING ACT OF 1970 REGULATIONS PETITIONS FOR EXEMPTIONS FROM POISON PREVENTION PACKAGING ACT REQUIREMENTS; PETITION...

16 CFR 1702.13 - Labeling and packaging samples.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Labeling and packaging samples. 1702.13 Section 1702.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION POISON PREVENTION PACKAGING ACT OF 1970 REGULATIONS PETITIONS FOR EXEMPTIONS FROM POISON PREVENTION PACKAGING ACT REQUIREMENTS; PETITION...

16 CFR 1702.13 - Labeling and packaging samples.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Labeling and packaging samples. 1702.13 Section 1702.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION POISON PREVENTION PACKAGING ACT OF 1970 REGULATIONS PETITIONS FOR EXEMPTIONS FROM POISON PREVENTION PACKAGING ACT REQUIREMENTS; PETITION...

Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C,15N-labeled peptides and proteins.

PubMed

Janik, Rafal; Ritz, Emily; Gravelle, Andrew; Shi, Lichi; Peng, Xiaohu; Ladizhansky, Vladimir

2010-03-01

In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly (13)C,(15)N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i-2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed. Copyright (c) 2009 Elsevier Inc. All rights reserved.

Aquatic Life Criteria - Ammonia

EPA Pesticide Factsheets

Documents related to EPA's final 2013 Aquatic Life Ambient Water Quality Criteria for Ammonia (Freshwater). These documents pertain to the safe levels of Ammonia in water that should protect to the majority of species.

Relative quantitation of glycosylation variants by stable isotope labeling of enzymatically released N-glycans using [12C]/[13C] aniline and ZIC-HILIC-ESI-TOF-MS.

PubMed

Giménez, Estela; Sanz-Nebot, Victòria; Rizzi, Andreas

2013-09-01

Glycan reductive isotope labeling (GRIL) using [(12)C]- and [(13)C]-coded aniline was used for relative quantitation of N-glycans. In a first step, the labeling method by reductive amination was optimized for this reagent. It could be demonstrated that selecting aniline as limiting reactant and using the reductant in excess is critical for achieving high derivatization yields (over 95 %) and good reproducibility (relative standard deviations ∼1-5 % for major and ∼5-10 % for minor N-glycans). In a second step, zwitterionic-hydrophilic interaction liquid chromatography in capillary columns coupled to electrospray mass spectrometry with time-of-flight analyzer (μZIC-HILIC-ESI-TOF-MS) was applied for the analysis of labeled N-glycans released from intact glycoproteins. Ovalbumin, bovine α1-acid-glycoprotein and bovine fetuin were used as test glycoproteins to establish and evaluate the methodology. Excellent separation of isomeric N-glycans and reproducible quantitation via the extracted ion chromatograms indicate a great potential of the proposed methodology for glycoproteomic analysis and for reliable relative quantitation of glycosylation variants in biological samples.

Doubly labelled water assessment of energy expenditure: principle, practice, and promise.

PubMed

Westerterp, Klaas R

2017-07-01

The doubly labelled water method for the assessment of energy expenditure was first published in 1955, application in humans started in 1982, and it has become the gold standard for human energy requirement under daily living conditions. The method involves enriching the body water of a subject with heavy hydrogen ( 2 H) and heavy oxygen ( 18 O), and then determining the difference in washout kinetics between both isotopes, being a function of carbon dioxide production. In practice, subjects get a measured amount of doubly labelled water ( 2 H 2 18 O) to increase background enrichment of body water for 18 O of 2000 ppm with at least 180 ppm and background enrichment of body water for 2 H of 150 ppm with 120 ppm. Subsequently, the difference between the apparent turnover rates of the hydrogen and oxygen of body water is assessed from blood-, saliva-, or urine samples, collected at the start and end of the observation interval of 1-3 weeks. Samples are analyzed for 18 O and 2 H with isotope ratio mass spectrometry. The doubly labelled water method is the indicated method to measure energy expenditure in any environment, especially with regard to activity energy expenditure, without interference with the behavior of the subjects. Applications include the assessment of energy requirement from total energy expenditure, validation of dietary assessment methods and validation of physical activity assessment methods with doubly labelled water measured energy expenditure as reference, and studies on body mass regulation with energy expenditure as a determinant of energy balance.

Aqueous Ammonia or Ammonium Hydroxide? Identifying a Base as Strong or Weak

ERIC Educational Resources Information Center

Sanger, Michael J.; Danner, Matthew

2010-01-01

When grocery stores sell solutions of ammonia, they are labeled "ammonia"; however, when the same solution is purchased from chemical supply stores, they are labeled "ammonium hydroxide". The goal of this experiment is for students to determine which name is more appropriate. In this experiment, students use several different experimental methods…

Orthogonal labeling of M13 minor capsid proteins with DNA to self-assemble end-to-end multiphage structures.

PubMed

Hess, Gaelen T; Guimaraes, Carla P; Spooner, Eric; Ploegh, Hidde L; Belcher, Angela M

2013-09-20

M13 bacteriophage has been used as a scaffold to organize materials for various applications. Building more complex multiphage devices requires precise control of interactions between the M13 capsid proteins. Toward this end, we engineered a loop structure onto the pIII capsid protein of M13 bacteriophage to enable sortase-mediated labeling reactions for C-terminal display. Combining this with N-terminal sortase-mediated labeling, we thus created a phage scaffold that can be labeled orthogonally on three capsid proteins: the body and both ends. We show that covalent attachment of different DNA oligonucleotides at the ends of the new phage structure enables formation of multiphage particles oriented in a specific order. These have potential as nanoscale scaffolds for multi-material devices.

Ammonia synthesis. Ammonia synthesis by N₂ and steam electrolysis in molten hydroxide suspensions of nanoscale Fe₂O₃.

PubMed

Licht, Stuart; Cui, Baochen; Wang, Baohui; Li, Fang-Fang; Lau, Jason; Liu, Shuzhi

2014-08-08

The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm(-2)) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm(-2) current density decreased to 1.0 V. Copyright © 2014, American Association for the Advancement of Science.

Evaluation of the novel myocardial perfusion positron-emission tomography tracer 18F-BMS-747158-02: comparison to 13N-ammonia and validation with microspheres in a pig model.

PubMed

Nekolla, S G; Reder, S; Saraste, A; Higuchi, T; Dzewas, G; Preissel, A; Huisman, M; Poethko, T; Schuster, T; Yu, M; Robinson, S; Casebier, D; Henke, J; Wester, H J; Schwaiger, M

2009-05-05

Positron-emission tomography (PET) tracers for myocardial perfusion are commonly labeled with short-lived isotopes that limit their widespread clinical use. 18F-BMS-747158-02 (18F-BMS) is a novel pyridaben derivative that was evaluated for assessment of myocardial perfusion by comparison with 13N-ammonia (13NH3) and with radioactive microspheres in a pig model. Fourteen pigs injected with 500 MBq of 13NH3 or 100 to 200 MBq of 18F-BMS underwent dynamic PET at rest and during pharmacological stress. In 8 of these pigs, 18F-BMS was injected during stress combined with transient, 2.5-minute constriction of the left anterior descending coronary artery. Radioactive microspheres were coinjected with 18F-BMS. Ratios of myocardial tracer uptake to surrounding tissues were determined, and myocardial blood flow was quantified by compartmental modeling. Both tracers showed high and homogeneous myocardial uptake. Compared with 13NH3, 18F-BMS showed higher activity ratios between myocardium and blood (rest 2.5 versus 4.1; stress 2.1 versus 5.8), liver (rest 1.2 versus 1.8; stress 0.7 versus 2.0), and lungs (rest 2.5 versus 4.2; stress 2.9 versus 6.4). Regional myocardial blood flow assessed with 18F-BMS PET showed good correlation (r=0.88, slope=0.84) and agreement (mean difference -0.10 [25th percentile -0.3, 75th percentile 0.1 mL x min(-1) x g(-1)]) with that measured with radioactive microspheres over a flow range from 0.1 to 3.0 mL x min(-1) x g(-1). The extent of defects induced by left anterior descending coronary artery constriction measured by 18F-BMS and microspheres also correlated closely (r=0.63, slope=1.1). 18F-BMS-747158-02 is a very attractive new PET perfusion tracer that allows quantitative assessment of regional myocardial perfusion over a wide flow range. The long half-life of 18F renders this tracer useful for clinical PET/CT applications in the workup of patients with suspected or proven coronary artery disease.

Refining cotton-wick method for 15N plant labelling.

NASA Astrophysics Data System (ADS)

Fustec, Joëlle; Mahieu, Stéphanie

2010-05-01

The symbiosis Fabaceae/Rhizobiaceae plays a critical role in the nitrogen cycle. It gives the plant the ability to fix high amounts of atmospheric N. A part of this N can be transferred to the soil via rhizodeposition. The contribution of Fabaceae to the soil N pool is difficult to measure, since it is necessary for assessing N benefits for other crops, for soil biological activity, and for reducing water pollution in sustainable agriculture (Fustec, 2009). The aim of this study was to test and improve the reliability of the 15N cotton-wick method for measuring the soil N derived from plant rhizodeposition (Mahieu et al., 2007). The effects of the concentration of the 15N-urea labelling solution and of the feeding frequency (continuous or pulses) on the assessment of nitrogen rhizodeposition were studied in two greenhouse experiments using the field pea (Pisum sativum L.) and the non-nodulating isoline P2. The plant parts and the soil were prepared for 15N:14N measurements for assessing N rhizodeposition (Mahieu et al., 2009). The fraction of plants' belowground nitrogen allocated to rhizodeposition in both Frisson pea and P2 was 20 to more than 50% higher when plants were labelled continuously than when they were labelled using fortnightly pulses. Our results suggested that when 15N root enrichment was high, nitrogen rhizodeposition was underestimated only for plants that were 15N-fed by fortnightly pulses, and not in plants 15N-fed continuously. This phenomenon was especially observed for plants relying on symbiotic N fixation for N acquisition; it may be linked to the concentration of the labelling solution. In conclusion, N rhizodeposition assessment was strongly influenced by the 15N-feeding frequency and the concentration of the labelling solution. The estimation of N rhizodeposition was more reliable when plants were labelled continuously with a dilute solution of 15N urea. Fustec et al. 2009. Agron. Sustain. Dev., DOI 10.1051/agro/2009003, in press. Mahieu

[Ammonia volatilization of slow release compound fertilizer in different soils water conditions].

PubMed

Hu, Xiao-feng; Wang, Zheng-yin; You, Yuan; Li, Jing-chao

2010-08-01

By using venting method incubation experiment, we studied the ammonia volatilization and kinetics characteristics of uncoated slowed release compound fertilizer (SRF) under different soil water conditions and the growth and nitrogen utilization efficiency of rice in pot experiment. Results indicated that the ammonia volatilization of SRF under waterflooding reached the peak ahead of 3-4 days compared to the moist treatment. The peak and accumulation of ammonia volatilization in the waterflooding treatments were higher than those under the moist condition. SRF could significantly reduce total ammonia volatilization compared to the common compound fertilizer (CCF), reduced by 50.6% and 22.8% in the moist treatment and reduced by 24.2% and 10.4% in the waterflooding treatment,but the loss of ammonia volatilization of SRF was higher significantly than that of the coated fertilizer (CRF). Ammonia volatilization increased with the increasing of fertilizer application. The dynamics of ammonia volatilization of SRF could be quantitatively described with three equations: the first order kinetics equation, Elovich equation and parabola equation. Compared to moist condition, the biomass of rice plant in SRF, CCF and SRF treatments increased by 67.86%, 78.25% and 48.75%, and nitrogen utilization efficiency increased by 57.73%, 80.70% and 12.06% under waterflooding condition, respectively. Comparing with CCF, nitrogen utilization efficiency in SRF treatment improved by 59.10% and 10.40% under two soil moisture conditions. SRF could reduce ammonia volatilization and improve biomass and nitrogen utilization efficiency.

Temperature Dependence of Cryogenic Ammonia-Water Ice Mixtures and Implications for Icy Satellite Surfaces

NASA Technical Reports Server (NTRS)

Dalton, J. B., III; Curchin, J. M.; Clark, R. N.

2001-01-01

Infrared spectra of ammonia-water ice mixtures reveal temperature-dependent absorption bands due to ammonia. These features, at 1.04, 2.0, and 2.25 microns, may shed light on the surface compositions of the Galilean and Saturnian satellites. Additional information is contained in the original extended abstract.

Ammonia in ground water from the Mississippi River alluvium, Fort Madison, Iowa

USGS Publications Warehouse

Linhart, S. Mike

2001-01-01

Water samples were collected from three municipal wells, two industrial wells, one watersupply well at the Iowa State Penitentiary, one domestic well, two creeks, and the Mississippi River. Tritium analytical results indicate that the time of recharge was after 1953 for water from the municipal wells (where tritium samples were collected). The ammonia concentration, 5.1 milligrams per liter, was considerably higher in ground water collected from well Fort Madison #4 compared to samples collected from other wells. The dissolved organic carbon concentration was also highest in ground water collected from well Fort Madison #4 (5.5 milligrams per liter) although samples from other wells were also relatively high, 2.6 to 5.3 milligrams per liter. The most likely process producing the high ammonia concentration in ground water in the vicinity of well Fort Madison #4 is decomposition of organic matter (ammonification). Nitrogen isotope values, when compared to nitrogen isotope values found in ground water in the vicinity of some of the other wells, indicate the possibility that a higher percentage of the ammonia found in ground water in the vicinity of well Fort Madison #4 may be from human and(or) other animal wastes. Higher concentrations of dissolved phosphorus, orthophosphate, and a higher chloride-to-sodium mole ratio found in ground water sampled from well Fort Madison #4 could be indicative of a sewage or septic source. Potential sources include existing or abandoned septic systems, leaking sanitary sewer lines, commercial or residential waste-disposal sites, and agricultural runoff upgradient from well Fort Madison #4, or possibly, bed sediments of the Mississippi River.

13 C Flux Analysis Reveals that Rebalancing Medium Amino Acid Composition can Reduce Ammonia Production while Preserving Central Carbon Metabolism of CHO Cell Cultures.

PubMed

McAtee Pereira, Allison G; Walther, Jason L; Hollenbach, Myles; Young, Jamey D

2018-02-06

13 C metabolic flux analysis (MFA) provides a rigorous approach to quantify intracellular metabolism of industrial cell lines. In this study, 13 C MFA was used to characterize the metabolic response of Chinese hamster ovary (CHO) cells to a novel medium variant designed to reduce ammonia production. Ammonia inhibits growth and viability of CHO cell cultures, alters glycosylation of recombinant proteins, and enhances product degradation. Ammonia production was reduced by manipulating the amino acid composition of the culture medium; specifically, glutamine, glutamate, asparagine, aspartate, and serine levels were adjusted. Parallel 13 C flux analysis experiments determined that, while ammonia production decreased by roughly 40%, CHO cell metabolic phenotype, growth, viability, and monoclonal antibody (mAb) titer were not significantly altered by the changes in media composition. This study illustrates how 13 C flux analysis can be applied to assess the metabolic effects of media manipulations on mammalian cell cultures. The analysis revealed that adjusting the amino acid composition of CHO cell culture media can effectively reduce ammonia production while preserving fluxes throughout central carbon metabolism. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of carbon-11, fluorine-18, and nitrogen-13 labeled radiotracers for biomedical applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fowler, J.S.; Wolf, A.P.

A number of reviews, many of them recent, have appeared on various aspects of /sup 11/C, /sup 18/F and /sup 13/N-labeled radiotracers. This monograph treats the topic principally from the standpoint of synthetic organic chemistry while keeping in perspective the necessity of integrating the organic chemistry with the design and ultimate application of the radiotracer. Where possible, recent examples from the literature of organic synthesis are introduced to suggest potentially new routes which may be applied to problems in labeling organic molecules with the short-lived positron emitters, carbon-11, fluorine-18, and nitrogen-13. The literature survey of carbon-11, fluorine-18 and nitrogen-13 labeledmore » compounds presented are of particular value to scientists working in this field. Two appendices are also included to provide supplementary general references. A subject index concludes this volume.« less

Ammonia-nitrogen sorptional properties of banana peels.

PubMed

Chen, Yunnen; Ding, Lichao; Fan, Jingbiao

2011-04-01

Using modified banana peel as a biosorbent to treat water containing ammonia-nitrogen (NH4(+)-N) was studied. Related parameters in the sorptional process, such as chemical modification, pH, and contact time were investigated. The experimental results showed that banana peel modified by 30% sodium hydroxide (NaOH) and mesothermal microwaves (NMBPs) can greatly improve the sorption removal for NH4(+)-N. The kinetics study revealed that the sorption behavior better fit the pseudo-second-order equation than the Lagergren first-order equation. Fourier transform infrared absorption spectrum analysis of banana peels and NMBPs before and after NH4(+)-N sorption revealed that the activity of hydroxyl groups at the surface of the banana peels was strengthened after modification, and nitrogenous groups appeared after biosorpting the NH4(+)-N. In the end, metallurgical wastewater containing a low concentration of NH4(+)-N was treated by NMBPs. The initial NH4(+)-N concentration of 138 mg/L was reduced to 13 mg/L in 25 minutes by 4 g/L NMBPs at pH 10.

Ammonia stress on nitrogen metabolism in tolerant aquatic plant-Myriophyllum aquaticum.

PubMed

Zhou, Qingyang; Gao, Jingqing; Zhang, Ruimin; Zhang, Ruiqin

2017-09-01

Ammonia has been a major reason of macrophyte decline in the water environment, and ammonium ion toxicity should be seen as universal, even in species frequently labeled as "NH 4 + specialists". To study the effects of high NH 4 + -N stress of ammonium ion nitrogen on tolerant submerged macrophytes and investigate the pathways of nitrogen assimilation in different organisms, Myriophyllum aquaticum was selected and treated with various concentrations of ammonium ions at different times. Increasing of ammonium concentration leads to an overall increase in incipient ammonia content in leaves and stems of plants. In middle and later stages, high concentrations of NH 4 + ion nitrogen taken up by M. aquaticum decreased, whereas the content of NO 3 - ion nitrogen increased. Moreover, in M. aquaticum, the activities of the enzymes nitrate reductase, glutamine synthetase and asparagine synthetase changed remarkably in the process of alleviating NH 4 + toxicity and deficiency. The results of the present study may support the studies on detoxification of high ammonium ion content in NH 4 + -tolerant submerged macrophytes and exploration of tissue-specific expression systems. Copyright © 2017. Published by Elsevier Inc.

Effects of ammonia-N stress on metabolic and immune function via the neuroendocrine system in Litopenaeus vannamei.

PubMed

Cui, Yanting; Ren, Xianyun; Li, Jian; Zhai, Qianqian; Feng, Yanyan; Xu, Yang; Ma, Li

2017-05-01

The purpose of this study was to evaluate the immunological responses, such as phenoloxidase (PO), antibacterial, and bacteriolytic activities, and metabolic variables, such as oxyhemocyanin, lactate, and glucose levels, of Litopenaeus vannamei exposed to ambient ammonia-N at 0, 2.5, 5, 7.5, and 10 mg/L for 0, 3, 6, 12, 24, and 48 h, and determine the effects of the eyestalk hormone on the metabolic and immune functions of unilateral eyestalk-ablated L. vannamei exposed to ambient ammonia-N at 10 mg/L. The actual concentrations of the control and test solutions were 0.04, 2.77, 6.01, 8.30, and 11.36 mg/L for ammonia-N and 0.01, 0.15, 0.32, 0.44, and 0.60 mg/L for NH 3 -N (unionized ammonia). The results showed a significant decrease in the PO, antibacterial, and bacteriolytic activities in the plasma as well as a significant increase in the glucose and lactate levels and decreased oxyhemocyanin levels in the hemolymph of L. vannamei exposed to elevated ammonia-N levels. These findings indicated that L. vannamei exposed to ammonia-N might demonstrate weakened metabolic and immunological responses. Moreover, eyestalk removal caused a dramatic decrease in PO, antibacterial, and bacteriolytic activities, which indicated that the eyestalk hormone in L. vannamei exhibited a higher immune response due to the induction of protective mechanisms against ammonia-N stress. Eyestalk removal also caused a dramatic decrease in glucose and lactate levels, suggesting that the eyestalk hormone is involved in glucose metabolism to meet the energy requirements under ammonia-N stress conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Surviving anoxia in marine sediments: The metabolic response of ubiquitous benthic foraminifera (Ammonia tepida).

PubMed

LeKieffre, Charlotte; Spangenberg, Jorge E; Mabilleau, Guillaume; Escrig, Stéphane; Meibom, Anders; Geslin, Emmanuelle

2017-01-01

High input of organic carbon and/or slowly renewing bottom waters frequently create periods with low dissolved oxygen concentrations on continental shelves and in coastal areas; such events can have strong impacts on benthic ecosystems. Among the meiofauna living in these environments, benthic foraminifera are often the most tolerant to low oxygen levels. Indeed, some species are able to survive complete anoxia for weeks to months. One known mechanism for this, observed in several species, is denitrification. For other species, a state of highly reduced metabolism, essentially a state of dormancy, has been proposed but never demonstrated. Here, we combined a 4 weeks feeding experiment, using 13C-enriched diatom biofilm, with correlated TEM and NanoSIMS imaging, plus bulk analysis of concentration and stable carbon isotopic composition of total organic matter and individual fatty acids, to study metabolic differences in the intertidal species Ammonia tepida exposed to oxic and anoxic conditions. Strongly contrasting cellular-level dynamics of ingestion and transfer of the ingested biofilm components were observed between the two conditions. Under oxic conditions, within a few days, intact diatoms were ingested, degraded, and their components assimilated, in part for biosynthesis of different cellular components: 13C-labeled lipid droplets formed after a few days and were subsequently lost (partially) through respiration. In contrast, in anoxia, fewer diatoms were initially ingested and these were not assimilated or metabolized further, but remained visible within the foraminiferal cytoplasm even after 4 weeks. Under oxic conditions, compound specific 13C analyses showed substantial de novo synthesis by the foraminifera of specific polyunsaturated fatty acids (PUFAs), such as 20:4(n-6). Very limited PUFA synthesis was observed under anoxia. Together, our results show that anoxia induced a greatly reduced rate of heterotrophic metabolism in Ammonia tepida on a time

Surviving anoxia in marine sediments: The metabolic response of ubiquitous benthic foraminifera (Ammonia tepida)

PubMed Central

Spangenberg, Jorge E.; Mabilleau, Guillaume; Escrig, Stéphane; Meibom, Anders; Geslin, Emmanuelle

2017-01-01

High input of organic carbon and/or slowly renewing bottom waters frequently create periods with low dissolved oxygen concentrations on continental shelves and in coastal areas; such events can have strong impacts on benthic ecosystems. Among the meiofauna living in these environments, benthic foraminifera are often the most tolerant to low oxygen levels. Indeed, some species are able to survive complete anoxia for weeks to months. One known mechanism for this, observed in several species, is denitrification. For other species, a state of highly reduced metabolism, essentially a state of dormancy, has been proposed but never demonstrated. Here, we combined a 4 weeks feeding experiment, using 13C-enriched diatom biofilm, with correlated TEM and NanoSIMS imaging, plus bulk analysis of concentration and stable carbon isotopic composition of total organic matter and individual fatty acids, to study metabolic differences in the intertidal species Ammonia tepida exposed to oxic and anoxic conditions. Strongly contrasting cellular-level dynamics of ingestion and transfer of the ingested biofilm components were observed between the two conditions. Under oxic conditions, within a few days, intact diatoms were ingested, degraded, and their components assimilated, in part for biosynthesis of different cellular components: 13C-labeled lipid droplets formed after a few days and were subsequently lost (partially) through respiration. In contrast, in anoxia, fewer diatoms were initially ingested and these were not assimilated or metabolized further, but remained visible within the foraminiferal cytoplasm even after 4 weeks. Under oxic conditions, compound specific 13C analyses showed substantial de novo synthesis by the foraminifera of specific polyunsaturated fatty acids (PUFAs), such as 20:4(n-6). Very limited PUFA synthesis was observed under anoxia. Together, our results show that anoxia induced a greatly reduced rate of heterotrophic metabolism in Ammonia tepida on a time

A method to trace root-respired CO2 using a 13C label

NASA Astrophysics Data System (ADS)

Cooperdock, S.; Breecker, D.; Litvak, M. E.

2014-12-01

In order to partition total soil respiration into root respiration and decomposition under ambient conditions in desert soils, the following method was developed using 13C-labeled CO2 in a modern juniper savannah in central New Mexico. The labeled CO2 was mixed with ambient air and pumped into a small (2.5 m diameter and 1.4 m tall) juniper tree canopy . 10 L of the 13CO2 was sufficient to generate a stream of air at 20 L/min for 1 hour with a CO2 concentration of 540 ppm and a δ13C value of approximately 35,000‰. Plastic tarpaulins were used as a wind block. The 13CO2 -labeled air was applied to the canopy during peak photosynthesis between 10 and 11 am on June 30 2014 during which canopy air CO2 was elevated by approximately 10 ppm over ambient and had δ13C values ranging from 50 to 1000 ‰. Over the next three days, gas and tissue samples were collected in order to trace the 13C label through the juniper tree. Leaf and root samples collected from the labeled tree and from several control trees were loaded into exetainer vials, flushed with CO2-free air and incubated in the dark for 5 hours in order to measure the carbon isotope composition of respired CO2. Samples of soil pore space gas were collected from wells under the labeled tree and a control tree and were transported to the laboratory in He-flushed exetainer vials. The δ13C values of CO2 in the soil gas samples and in the headspace of incubation vials were measured using an isotope ratio mass spectrometer. The δ13C values of foliar respiration were significantly higher than those of the control (by 3.6‰, p < 0.01) one and two days after labeling and δ13C values of root-respired CO2 were significantly higher (by 0.7‰, p = 0.01) than those of the control three days after labeling. In addition, δ13C values of soil respired CO2, determined from measurements of soil pore space CO2 at 50 cm three days after labeling, were significantly higher (by 0.7‰, p < 0.03)) for the labeled tree than control

USE OF ZEOLITE FOR REMOVING AMMONIA AND AMMONIA-CAUSED TOXCITY IN MARINE TOXICITY IDENTIFCATION EVALUATIONS (TIES)

EPA Science Inventory

Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifyi...

SWAG: Survey of Water and Ammonia in the Galactic Center

NASA Astrophysics Data System (ADS)

Ott, Jürgen; Meier, David S.; Krieger, Nico; Rickert, Matthew

2017-01-01

SWAG (``Survey of Water and Ammonia in the Galactic Center'') is a multi-line interferometric survey toward the Center of the Milky Way conducted with the Australia Telescope Compact Array. The survey region spans the entire ~400 pc Central Molecular Zone and comprises ~42 spectral lines at pc spatial and sub-km/s spectral resolution. In addition, we deeply map continuum intensity, spectral index, and polarization at the frequencies where synchrotron, free-free, and thermal dust sources emit. The observed spectral lines include many transitions of ammonia, which we use to construct maps of molecular gas temperature, opacity and gas formation temperature (see poster by Nico Krieger et al., this volume). Water masers pinpoint the sites of active star formation and other lines are good tracers for density, radiation field, shocks, and ionization. This extremely rich survey forms a perfect basis to construct maps of the physical parameters of the gas in this extreme environment.

Assessing Ammonia Treatment Options

EPA Science Inventory

This is the second of three articles to help water system operators understand ammonia and how to monitor and control its effects at the plant and in the distribution system. The first article (Opflow, April 2012) provided an overview of ammonia's chemistry, origins, and water sy...

TES/Aura L2 Ammonia (NH3) Nadir V6 (TL2NH3N)

Atmospheric Science Data Center

2018-01-18

TES/Aura L2 Ammonia (NH3) Nadir (TL2NH3N) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Ammonia Spatial Coverage:  5.3 x 8.5 km nadir ... Contact User Services Parameters:  Ammonia Legacy:  Retired data product , click here for ...

Electrocatalytic Synthesis of Ammonia at Room Temperature and Atmospheric Pressure from Water and Nitrogen on a Carbon-Nanotube-Based Electrocatalyst.

PubMed

Chen, Shiming; Perathoner, Siglinda; Ampelli, Claudio; Mebrahtu, Chalachew; Su, Dangsheng; Centi, Gabriele

2017-03-01

Ammonia is synthesized directly from water and N 2 at room temperature and atmospheric pressure in a flow electrochemical cell operating in gas phase (half-cell for the NH 3 synthesis). Iron supported on carbon nanotubes (CNTs) was used as the electrocatalyst in this half-cell. A rate of ammonia formation of 2.2×10 -3  gNH3  m -2  h -1 was obtained at room temperature and atmospheric pressure in a flow of N 2 , with stable behavior for at least 60 h of reaction, under an applied potential of -2.0 V. This value is higher than the rate of ammonia formation obtained using noble metals (Ru/C) under comparable reaction conditions. Furthermore, hydrogen gas with a total Faraday efficiency as high as 95.1 % was obtained. Data also indicate that the active sites in NH 3 electrocatalytic synthesis may be associated to specific carbon sites formed at the interface between iron particles and CNT and able to activate N 2 , making it more reactive towards hydrogenation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

16 CFR 300.13 - Name or other identification required to appear on labels.

Code of Federal Regulations, 2011 CFR

2011-01-01

... appear on labels. 300.13 Section 300.13 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULES AND REGULATIONS UNDER THE WOOL PRODUCTS LABELING ACT OF 1939 Labeling § 300... in § 300.4 of this part (Rule 4), may be used for identification purposes in lieu of the required...

Flow of ices in the Ammonia-Water System

NASA Technical Reports Server (NTRS)

Durham, W. B.; Kirby, S. H.; Stern, L. A.

1993-01-01

We have fabricated in the laboratory and subsequently deformed crystalline hydrates and partial melts of the water-rich end of the NH3-H2O system, with the aim of improving our understanding of physical processes occurring in icy moons of the outer solar system. Deformation experiments were carried out at constant strain rate. The range of experimental variables are given. Phase relationships in the NH3-H2O system indicate that water ice and ammonia dihydrate, NH3-2H2O, are the stable phases under our experiment conditions. X-ray diffraction of our samples usually revealed these as the dominant phases, but we have also observed an amorphous phase (in unpressurized samples only) and occasionally significant ammonia monohydrate, NH3-H2O. The onset of partial melting at the peritectic temperature at about 176 K appeared as a sharp transition in strength observed in samples of x(sub NH3) = 0.05 and 0.01, the effect of melt was less pronounced. For any given water ice + dihydrate alloy in the subsolidus region, we observed one rheological law over the entire temperature range from 175 K to about 140 K. Below 140 K, a shear instability similar to that occurring in pure water ice under the same conditions limited our ability to measure ductile flow. The rheological laws for the several alloys vary systematically from that of pure ice to that of dihydrate. Pure dihydrate is about 4 orders of magnitude less viscous than water ice just below the peritectic temperature, but because of a very pronounced temperature dependence in dihydrate (100 kJ/mol versus 43 kJ/mol for water ice) the viscosity of dihydrate equals or exceeds that of water ice at T less than 140 K. The large variation in viscosity of dihydrate with relatively small changes in temperature may be helpful in explaining the rich variety of tectonic and volcanic features seen on the surfaces of icy moons in the outer solar system.

13C-labelled microdialysis studies of cerebral metabolism in TBI patients☆

PubMed Central

Carpenter, Keri L.H.; Jalloh, Ibrahim; Gallagher, Clare N.; Grice, Peter; Howe, Duncan J.; Mason, Andrew; Timofeev, Ivan; Helmy, Adel; Murphy, Michael P.; Menon, David K.; Kirkpatrick, Peter J.; Carpenter, T. Adrian; Sutherland, Garnette R.; Pickard, John D.; Hutchinson, Peter J.

2014-01-01

Human brain chemistry is incompletely understood and better methodologies are needed. Traumatic brain injury (TBI) causes metabolic perturbations, one result of which includes increased brain lactate levels. Attention has largely focussed on glycolysis, whereby glucose is converted to pyruvate and lactate, and is proposed to act as an energy source by feeding into neurons’ tricarboxylic acid (TCA) cycle, generating ATP. Also reportedly upregulated by TBI is the pentose phosphate pathway (PPP) that does not generate ATP but produces various molecules that are putatively neuroprotective, antioxidant and reparative, in addition to lactate among the end products. We have developed a novel combination of 13C-labelled cerebral microdialysis both to deliver 13C-labelled substrates into brains of TBI patients and recover the 13C-labelled metabolites, with high-resolution 13C NMR analysis of the microdialysates. This methodology has enabled us to achieve the first direct demonstration in humans that the brain can utilise lactate via the TCA cycle. We are currently using this methodology to make the first direct comparison of glycolysis and the PPP in human brain. In this article, we consider the application of 13C-labelled cerebral microdialysis for studying brain energy metabolism in patients. We set this methodology within the context of metabolic pathways in the brain, and 13C research modalities addressing them. PMID:24361470

Microsolvation effect and hydrogen-bonding pattern of taurine-water TA-(H2O)n (n = 1-3) complexes.

PubMed

Dai, Yumei; Wang, Yuhua; Huang, Zhengguo; Wang, Hongke; Yu, Lei

2012-01-01

The microsolvation of taurine (TA) with one, two or three water molecules was investigated by a density functional theory (DFT) approach. Quantum theory of atoms in molecules (QTAIM) analyses were employed to elucidate the hydrogen bond (H-bond) interaction characteristics in TA-(H(2)O)(n) (n = 1-3) complexes. The results showed that the intramolecular H-bond formed between the hydroxyl and the N atom of TA are retained in most TA-(H(2)O)(n) (n = 1-3) complexes, and are strengthened via cooperative effects among multiple H-bonds from n = 1-3. A trend of proton transformation exists from the hydroxyl to the N atom, which finally results in the cleavage of the origin intramolecular H-bond and the formation of a new intramolecular H-bond between the amino and the O atom of TA. Therefore, the most stable TA-(H(2)O)(3) complex becomes a zwitterionic complex rather than a neutral type. A many-body interaction analysis showed that the major contributors to the binding energies for complexes are the two-body energies, while three-body energies and relaxation energies make significant contributions to the binding energies for some complexes, whereas the four-body energies are too small to be significant.

Sanitising black water by auto-thermal aerobic digestion (ATAD) combined with ammonia treatment.

PubMed

Nordin, Annika C; Vinnerås, Björn

2015-01-01

The effect of a two-step process on the concentration of pathogens and indicator microorganisms in black water (0.9-1% total solids) was studied. The treatment combined auto-thermal aerobic digestion (ATAD) and ammonia sanitisation. First, the temperature of the black water was increased through ATAD and when a targeted temperature was reached (33, 41 and 45.5 °C studied), urea was added to a 0.5% concentration (total ammonia nitrogen >2.9 g L⁻¹). Escherichia coli and Salmonella spp. were reduced to non-detectable levels within 3 days following urea addition at temperatures above 40 °C, whereas when urea was added at 33 °C E. coli was still present after 8 days. By adding urea at temperatures of 40 °C and above, a 5 log10 reduction in Enterococcus spp. and a 3 log10 reduction in Ascaris suum eggs was achieved 1 week after the addition. With combined ATAD and ammonia treatment using 0.5% ww urea added at an aerobic digestion temperature >40 °C, black water was sanitised regarding the pathogens studied in 2 weeks of total treatment time.

Ion pair-based liquid-phase microextraction combined with cuvetteless UV-vis micro-spectrophotometry as a miniaturized assay for monitoring ammonia in waters.

PubMed

Senra-Ferreiro, Sonia; Pena-Pereira, Francisco; Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos

2011-09-15

A miniaturized method based on liquid-phase microextraction (LPME) in combination with microvolume UV-vis spectrophotometry for monitoring ammonia in waters is proposed. The methodology is based on the extraction of the ion pair formed between the blue indophenol obtained according to the Berthelot reaction and a quaternary ammonium salt into a microvolume of organic solvent. Experimental parameters affecting the LPME performance such as type and concentration of the quaternary ammonium ion salt required to form the ion pair, type and volume of extractant solvent, effect of disperser solvent, ionic strength and extraction time, were optimized. A detection limit of 5.0 μg L(-1) ammonia and an enrichment factor of 30 can be attained after a microextraction time of 4 min. The repeatability, expressed as relative standard deviation, was 7.6% (n=7). The proposed method can be successfully applied to the determination of trace amounts of ammonia in several environmental water samples. Copyright © 2011 Elsevier B.V. All rights reserved.

A spatial ammonia emission inventory for pig farming

NASA Astrophysics Data System (ADS)

Rebolledo, Boris; Gil, Antonia; Pallarés, Javier

2013-01-01

Atmospheric emissions of ammonia (NH3) from the agricultural sector have become a significant environmental and public concern as they have impacts on human health and ecosystems. This work proposes an improved methodology in order to identify administrative regions with high NH3 emissions from pig farming and calculates an ammonia density map (kg NH3-N ha-1), based on the number of pigs and available agricultural land, terrain slopes, groundwater bodies, soil permeability, zones sensitive to nitrate pollution and surface water buffer zones. The methodology has been used to construct a general tool for locating ammonia emissions from pig farming when detailed information of livestock farms is not available.

Can surface-applied zeolite reduce ammonia losses from feedyard manure? A laboratory study

USDA-ARS?s Scientific Manuscript database

Ammonia emission from beef cattle feedyard manure results in losses of nitrogen (N), which may negatively affect air, soil, and water quality. The magnitude and rate of ammonia volatilization from feedyards partially depends on the amount of urinary urea excreted and dissociation of ionic ammonium ...

Active ammonia oxidizers in an acidic soil are phylogenetically closely related to neutrophilic archaeon.

PubMed

Wang, Baozhan; Zheng, Yan; Huang, Rong; Zhou, Xue; Wang, Dongmei; He, Yuanqiu; Jia, Zhongjun

2014-03-01

All cultivated ammonia-oxidizing archaea (AOA) within the Nitrososphaera cluster (former soil group 1.1b) are neutrophilic. Molecular surveys also indicate the existence of Nitrososphaera-like phylotypes in acidic soil, but their ecological roles are poorly understood. In this study, we present molecular evidence for the chemolithoautotrophic growth of Nitrososphaera-like AOA in an acidic soil with pH 4.92 using DNA-based stable isotope probing (SIP). Soil microcosm incubations demonstrated that nitrification was stimulated by urea fertilization and accompanied by a significant increase in the abundance of AOA rather than ammonia-oxidizing bacteria (AOB). Real-time PCR analysis of amoA genes as a function of the buoyant density of the DNA gradient following the ultracentrifugation of the total DNA extracted from SIP microcosms indicated a substantial growth of soil AOA during nitrification. Pyrosequencing of the total 16S rRNA genes in the "heavy" DNA fractions suggested that archaeal communities were labeled to a much greater extent than soil AOB. Acetylene inhibition further showed that (13)CO2 assimilation by nitrifying communities depended solely on ammonia oxidation activity, suggesting a chemolithoautotrophic lifestyle. Phylogenetic analysis of both (13)C-labeled amoA and 16S rRNA genes revealed that most of the active AOA were phylogenetically closely related to the neutrophilic strains Nitrososphaera viennensis EN76 and JG1 within the Nitrososphaera cluster. Our results provide strong evidence for the adaptive growth of Nitrososphaera-like AOA in acidic soil, suggesting a greater metabolic versatility of soil AOA than previously appreciated.

Active Ammonia Oxidizers in an Acidic Soil Are Phylogenetically Closely Related to Neutrophilic Archaeon

PubMed Central

Wang, Baozhan; Zheng, Yan; Huang, Rong; Zhou, Xue; Wang, Dongmei; He, Yuanqiu

2014-01-01

All cultivated ammonia-oxidizing archaea (AOA) within the Nitrososphaera cluster (former soil group 1.1b) are neutrophilic. Molecular surveys also indicate the existence of Nitrososphaera-like phylotypes in acidic soil, but their ecological roles are poorly understood. In this study, we present molecular evidence for the chemolithoautotrophic growth of Nitrososphaera-like AOA in an acidic soil with pH 4.92 using DNA-based stable isotope probing (SIP). Soil microcosm incubations demonstrated that nitrification was stimulated by urea fertilization and accompanied by a significant increase in the abundance of AOA rather than ammonia-oxidizing bacteria (AOB). Real-time PCR analysis of amoA genes as a function of the buoyant density of the DNA gradient following the ultracentrifugation of the total DNA extracted from SIP microcosms indicated a substantial growth of soil AOA during nitrification. Pyrosequencing of the total 16S rRNA genes in the “heavy” DNA fractions suggested that archaeal communities were labeled to a much greater extent than soil AOB. Acetylene inhibition further showed that 13CO2 assimilation by nitrifying communities depended solely on ammonia oxidation activity, suggesting a chemolithoautotrophic lifestyle. Phylogenetic analysis of both 13C-labeled amoA and 16S rRNA genes revealed that most of the active AOA were phylogenetically closely related to the neutrophilic strains Nitrososphaera viennensis EN76 and JG1 within the Nitrososphaera cluster. Our results provide strong evidence for the adaptive growth of Nitrososphaera-like AOA in acidic soil, suggesting a greater metabolic versatility of soil AOA than previously appreciated. PMID:24375137

Changes of Ammonia-Metabolizing Enzyme Activity and Gene Expression of Two Strains in Shrimp Litopenaeus vannamei Under Ammonia Stress

PubMed Central

Qiu, Liguo; Shi, Xiang; Yu, Simeng; Han, Qian; Diao, Xiaoping; Zhou, Hailong

2018-01-01

Ammonia stress can inhibit the survival and growth, and even cause mortality of shrimp. In this study, ammonia-metabolizing enzyme activities and gene expression were compared between two strains of L. vannamei under different ammonia-N (NH4+) concentrations (3.4, 13.8, and 24.6 mg/L). The results showed that elevated ammonia concentrations mainly increased glutamine synthetase (GSase) activities while inhibiting transglutaminase (TGase) activities in the muscle of both strains. Thus, we concluded that L. vannamei could accelerate the synthesis of glutamine from glutamate and NH4+ to alleviate ammonia stress. Compared with the muscle, the hepatopancreas plays a major role in ammonia stress and might be a target tissue to respond to the ammonia stress. Compared to the control group, the treatment of high ammonia concentrations reduced the hepatopancreas TGase (TG) gene expression and increased the gene expression rates of glutamate dehydrogenase-β (GDH-β) and GSase (GS) in both the muscle and the hepatopancreas of the two strains (p < 0.05). These genes (GDH-β and GS) in strain B were not only expressed earlier but also at levels higher than the expression range of strain A. At the gene level, strain B showed a more rapid and positive response than strain A. These data might help reveal the physiological responses mechanisms of shrimp adapt to ammonia stress and speed up the selective breeding process in L. vannamei. PMID:29628893

16 CFR § 1702.13 - Labeling and packaging samples.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Labeling and packaging samples. § 1702.13 Section § 1702.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION POISON PREVENTION PACKAGING ACT OF 1970 REGULATIONS PETITIONS FOR EXEMPTIONS FROM POISON PREVENTION PACKAGING ACT REQUIREMENTS...

Water-Ammonia Ionic Ocean on Uranus and Neptune-Clue from Tropospheric Hydrogen Sulfide Clouds

NASA Astrophysics Data System (ADS)

Atreya, S. K.; Egeler, P. A.; Wong, A.

2005-12-01

Interior models of the ice-giants, Uranus and Neptune, predict a water-ammonia ionic ocean at tens of kilobar pressure [1,2]. If correct, its implication for planetary formation models is profound. In this presentation we demonstrate that the existence of an ionic ocean will manifest itself in the planets' tropospheric cloud structure, particularly in the form of a hydrogen sulfide, i.e. H2S-ice, cloud. In fact, an H2S cloud was introduced ad hoc in the 3-5 bar region to explain microwave absorption [3] and the methane [4] observations, but its presence cannot be proved in the absence of entry probes. Our equilibrium cloud condensation model (ECCM) shows that an H2S-ice cloud does not form when conventional enrichment factors (20-30× solar at Uranus, and 30-50× solar at Neptune) are employed for all heavy elements (mass >4) [5]. However, a deep ``cloud'' composed of a weak solution of ammonia and water forms, and its base is at 370 and 500 bars, respectively, for 30× solar and 50× solar enrichment factors. If an ionic ``ocean'' exists much deeper, water vapor, as well as ammonia dissolved in it, would be severely depleted at levels above this ocean. The consequences of such water vapor and ammonia depletions are that (1) clouds of water and ammonia, if present, are much less prominent; (2) only small amount of H2S vapor is removed by NH3, to form an NH4SH cloud; so that (3) a cloud of H2S-ice can now form; and (4) an H2O ``ocean'' in the 1-kilobar region [6] does not form. This scenario has important implications for the design of entry probe missions, as measurements to only 10-20 bars, rather than kilobar levels, will need to be made. The heavy elements, Ar, Kr, Xe, Ne, C, and S, as well as He, D/H, GeH4, AsH3, PH3, and CO can all be accessed at pressures less than 20 bars. These measurements are critical for constraining the formation models [5,7,8]. Measurement of water in the well-mixed region of Uranus and Neptune is technologically highly challenging

Selective detection of carbon-13, nitrogen-15, and deuterium labeled metabolites by capillary gas chromatography-chemical reaction interface/mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chace, D.H.; Abramson, F.P.

1989-12-15

We have applied a new chemical reaction interface/mass spectrometer technique (CRIMS) to the selective detection of 13C-, 15N-, and 2H-labeled phenytoin and its metabolites in urine following separation by capillary gas chromatography. The microwave-powered chemical reaction interface converts materials from their original forms into small molecules whose mass spectra serve to identify and quantify the nuclides that make up each analyte. The presence of each element is followed by monitoring the isotopic variants of CO2, NO, or H2 that are produced by the chemical reaction interface. Chromatograms showing only enriched 13C and 15N were produced by subtracting the abundance ofmore » naturally occurring isotopes from the observed M + 1 signal. A selective chromatogram of 2H (D) was obtained by measuring HD at m/z 3.0219 with a resolution of 2000. Metabolites representing less than 1.5% of the total labeled compounds could be identified in the chromatogram. Detection limits from urine of 380 pg/mL of a 15N-labeled metabolite, 7 ng/mL of a 13C-labeled metabolite, and 16 ng/mL of a deuterium labeled metabolite were determined at a signal to noise ratio of 2. Depending on the isotope examined, a linear dynamic range of 250-1000 was observed using CRIMS. To identify many of these labeled peaks (metabolites), the chromatographic analysis was repeated with the chemical reaction interface turned off and mass spectra obtained at the retention times found in the CRIMS experiment. CRIMS is a new analytical method that appears to be particularly useful for metabolism studies.« less

78 FR 52192 - Final Aquatic Life Ambient Water Quality Criteria For Ammonia-Freshwater 2013

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-22

... ambient water quality criteria for the protection of aquatic life from effects of ammonia in freshwater... life criteria are developed based on EPA's Guidelines for Deriving Numerical National Water Quality... quality standards for protecting aquatic life and human health. EPA's recommended water quality criteria...

In vitro activation of ammonia monooxygenase from Nitrosomonas europaea by copper.

PubMed Central

Ensign, S A; Hyman, M R; Arp, D J

1993-01-01

The effect of copper on the in vivo and in vitro activity of ammonia monooxygenase (AMO) from the nitrifying bacterium Nitrosomonas europaea was investigated. The addition of CuCl2 to cell extracts resulted in 5- to 15-fold stimulation of ammonia-dependent O2 consumption, ammonia-dependent nitrite production, and hydrazine-dependent ethane oxidation. AMO activity was further stimulated in vitro by the presence of stabilizing agents, including serum albumins, spermine, or MgCl2. In contrast, the addition of CuCl2 and stabilizing agents to whole-cell suspensions did not result in any stimulation of AMO activity. The use of the AMO-specific suicide substrate acetylene revealed two populations of AMO in cell extracts. The low, copper-independent (residual) AMO activity was completely inactivated by acetylene in the absence of exogenously added copper. In contrast, the copper-dependent (activable) AMO activity was protected against acetylene inactivation in the absence of copper. However, in the presence of copper both populations of AMO were inactivated by acetylene. [14C]acetylene labelling of the 27-kDa polypeptide of AMO revealed the same extent of label incorporation in both whole cells and optimally copper-stimulated cell extracts. In the absence of copper, the label incorporation in cell extracts was proportional to the level of residual AMO activity. Other metal ions tested, including Zn2+, Co2+, Ni2+, Fe2+, Fe3+, Ca2+, Mg2+, Mn2+, Cr3+, and Ag+, were ineffective at stimulating AMO activity or facilitating the incorporation of 14C label from [14C]acetylene into the 27-kDa polypeptide. On the basis of these results, we propose that loss of AMO activity upon lysis of N. europaea results from the loss of copper from AMO, generating a catalytically inactive, yet stable and activable, form of the enzyme. Images PMID:8458839

Application of capillary gas chromatography-reaction interface/mass spectrometry to the selective detection of sup 13 C-, sup 15 N-, sup 2 H-, and sup 14 C-labeled drugs and their metabolites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chace, D.H.

1989-01-01

A novel reaction interface/mass spectrometer (RIMS) technique has been applied to the selective detection of {sup 13}C-, {sup 15}N-, {sup 2}H-, and {sup 14}C-labeled phenytoin and its metabolites in urine following separation by capillary gas chromatography. The microwave-powered reaction interface converts materials from their original forms into small molecules whose mass spectra serve to identify and quantify the nuclides. The presence of each element is followed by monitoring the isotopic variants of CO{sub 2}, NO, H{sub 2}, or CH{sub 4} that are produced by the reaction interface. Chromatograms showing only enriched {sup 13}C and {sup 15}N were produced using themore » net {sup 13}CO{sub 2} or {sup 15}NO signal derived by subtracting the abundance of naturally occurring isotopes from the observed M + 1 signal. When hydrogen was used as a reactant gas, a selective chromatogram of {sup 2}H (D) was obtained by measuring HD at m/Z 3.0219, and a chromatogram showing {sup 14}C was obtained by measuring {sup 14}CH{sub 4} at m/Z 18.034 with a high resolution. For a stable isotope detection, metabolites representing less than 1.5% of the total labeled compounds could be detected in the chromatogram. Detection limits of 170 pCi/mL (34 pCi on column that is equivalent to 187 pg) of a {sup 14}C- labeled metabolite was detected. To identify many of these labeled peaks (metabolites), the chromatographic analysis was repeated with the reaction interface turned off and mass spectra obtained at the retention times found in the RIMS experiment. In addition to the ability of GC-RIMS to detect the presence of {sup 13}C-, {sup 15}N-, and {sup 2}H- (D), it can also quantify the level of enrichment. Enrichment of {sup 13}C and {sup 15}N is quantified by measuring the ratio of excess {sup 13}CO{sub 2} to total {sup 12}CO{sub 2} or excess {sup 15}NO to total {sup 14}NO.« less

Competition for ammonia influences the structure of chemotrophic communities in geothermal springs.

PubMed

Hamilton, Trinity L; Koonce, Evangeline; Howells, Alta; Havig, Jeff R; Jewell, Talia; de la Torre, José R; Peters, John W; Boyd, Eric S

2014-01-01

Source waters sampled from Perpetual Spouter hot spring (pH 7.03, 86.4°C), Yellowstone National Park, WY, have low concentrations of total ammonia, nitrite, and nitrate, suggesting nitrogen (N) limitation and/or tight coupling of N cycling processes. Dominant small-subunit rRNA sequences in Perpetual Spouter source sediments are closely affiliated with the ammonia-oxidizing archaeon "Candidatus Nitrosocaldus yellowstonii" and the putatively nitrogen-fixing (diazotrophic) bacterium Thermocrinis albus, respectively, suggesting that these populations may interact at the level of the bioavailable N pool, specifically, ammonia. This hypothesis was evaluated by using a combination of geochemical, physiological, and transcriptomic analyses of sediment microcosms. Amendment of microcosms with allylthiourea, an inhibitor of ammonia oxidation, decreased rates of acetylene reduction (a proxy for N2 fixation) and nitrite production (a proxy for ammonia oxidation) and decreased transcript levels of structural genes involved in both nitrogen fixation (nifH) and ammonia oxidation (amoA). In contrast, amendment of microcosms with ammonia stimulated nitrite production and increased amoA transcript levels while it suppressed rates of acetylene reduction and decreased nifH transcript levels. Sequencing of amplified nifH and amoA transcripts from native sediments, as well as microcosms, at 2 and 4 h postamendment, indicates that the dominant and responsive populations involved in ammonia oxidation and N2 fixation are closely affiliated with Ca. Nitrosocaldus yellowstonii and T. albus, respectively. Collectively, these results suggest that ammonia-oxidizing archaea, such as Ca. Nitrosocaldus yellowstonii, have an apparent affinity for ammonia that is higher than that of the diazotrophs present in this ecosystem. Depletion of the bioavailable N pool through the activity of ammonia-oxidizing archaea likely represents a strong selective pressure for the inclusion of organisms capable of

Competition for Ammonia Influences the Structure of Chemotrophic Communities in Geothermal Springs

PubMed Central

Hamilton, Trinity L.; Koonce, Evangeline; Howells, Alta; Havig, Jeff R.; Jewell, Talia; de la Torre, José R.; Peters, John W.

2014-01-01

Source waters sampled from Perpetual Spouter hot spring (pH 7.03, 86.4°C), Yellowstone National Park, WY, have low concentrations of total ammonia, nitrite, and nitrate, suggesting nitrogen (N) limitation and/or tight coupling of N cycling processes. Dominant small-subunit rRNA sequences in Perpetual Spouter source sediments are closely affiliated with the ammonia-oxidizing archaeon “Candidatus Nitrosocaldus yellowstonii” and the putatively nitrogen-fixing (diazotrophic) bacterium Thermocrinis albus, respectively, suggesting that these populations may interact at the level of the bioavailable N pool, specifically, ammonia. This hypothesis was evaluated by using a combination of geochemical, physiological, and transcriptomic analyses of sediment microcosms. Amendment of microcosms with allylthiourea, an inhibitor of ammonia oxidation, decreased rates of acetylene reduction (a proxy for N2 fixation) and nitrite production (a proxy for ammonia oxidation) and decreased transcript levels of structural genes involved in both nitrogen fixation (nifH) and ammonia oxidation (amoA). In contrast, amendment of microcosms with ammonia stimulated nitrite production and increased amoA transcript levels while it suppressed rates of acetylene reduction and decreased nifH transcript levels. Sequencing of amplified nifH and amoA transcripts from native sediments, as well as microcosms, at 2 and 4 h postamendment, indicates that the dominant and responsive populations involved in ammonia oxidation and N2 fixation are closely affiliated with Ca. Nitrosocaldus yellowstonii and T. albus, respectively. Collectively, these results suggest that ammonia-oxidizing archaea, such as Ca. Nitrosocaldus yellowstonii, have an apparent affinity for ammonia that is higher than that of the diazotrophs present in this ecosystem. Depletion of the bioavailable N pool through the activity of ammonia-oxidizing archaea likely represents a strong selective pressure for the inclusion of organisms capable

Stimulation of thaumarchaeal ammonia oxidation by ammonia derived from organic nitrogen but not added inorganic nitrogen.

PubMed

Levičnik-Höfferle, Spela; Nicol, Graeme W; Ausec, Luka; Mandić-Mulec, Ines; Prosser, James I

2012-04-01

Ammonia oxidation, the first step in nitrification, is performed by autotrophic bacteria and thaumarchaea, whose relative contributions vary in different soils. Distinctive environmental niches for the two groups have not been identified, but evidence from previous studies suggests that activity of thaumarchaea, unlike that of bacterial ammonia oxidizers, is unaffected by addition of inorganic N fertilizer and that they preferentially utilize ammonia generated from the mineralization of organic N. This hypothesis was tested by determining the influence of both inorganic and organic N sources on nitrification rate and ammonia oxidizer growth and community structure in microcosms containing acidic, forest soil in which ammonia oxidation was dominated by thaumarchaea. Nitrification rate was unaffected by the incubation of soil with inorganic ammonium but was significantly stimulated by the addition of organic N. Oxidation of ammonia generated from native soil organic matter or added organic N, but not added inorganic N, was accompanied by increases in abundance of the thaumarchaeal amoA gene, a functional gene for ammonia oxidation, but changes in community structure were not observed. Bacterial amoA genes could not be detected. Ammonia oxidation was completely inhibited by 0.01% acetylene in all treatments, indicating ammonia monooxygenase-dependent activity. The findings have implications for current models of soil nitrification and for nitrification control strategies to minimize fertilizer loss and nitrous oxide production. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Factors which affect cerebral uptake and retention of /sup 13/NH/sub 3/. [Testing in monkeys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phelps, M.E.; Raichle, M.E.; Hoffman, E.J.

1977-01-01

The single pass extraction of ammonia (E) by cerebral capillaries was studied in vivo in Rhesus monkeys with /sup 13/N. The value of E for /sup 13/N-ammonia was found to be less than 100%, inversely related to cerebral blood flow and to be limited by the permeability of the blood brain barrier for ammonia. A vaue of the permeability surface area product was determined to be 0.0040 x 10/sup -4/ cm/sup 3//sec/gm. The single pass extraction fraction, E, for /sup 13/N-ammonia was found to be independent of arterial blood pH (in the range of 7.2 to 7.6) and of arterialmore » blood ammonia concentration (in the range of 80-1400 ..mu..gms/100 cc). An insulin induced hypoglycemic reduction in the cerebral metabolic rate for glucose and oxygen of 54% produced a reduction in E of about 24%. When a condition of elevated arterial blood ammonia was added to hypoglycemia, the value of E and cerebral metabolic rate for oxygen remained low while the cerebral metabolic rate for glucose increased by a factor of 2.5 indicating the presence of a detoxification shunt for ammonia. Positron tomographic images of the equilibrium cross section distribution of /sup 13/N-ammonia appeared to reflect regional differences in capillary density of the cerebral tissue.« less

Development of water quality criteria of ammonia for protecting aquatic life in freshwater using species sensitivity distribution method.

PubMed

Park, Tae-Jin; Lee, Jong-Hyeon; Lee, Myung-Sung; Park, Chang-Hee; Lee, Chang-Hoon; Moon, Seong-Dae; Chung, Jiwoong; Cui, Rongxue; An, Youn-Joo; Yeom, Dong-Hyuk; Lee, Soo-Hyung; Lee, Jae-Kwan; Zoh, Kyung-Duk

2018-09-01

Ammonia is deemed one of the most important pollutants in the freshwater environment because of its highly toxic nature and ubiquity in surface water. This study thus aims to derive the criteria for ammonia in freshwater to protect aquatic life because there are no water quality criteria for ammonia in Korea. Short-term lethal tests were conducted to perform the species sensitivity distribution (SSD) method. This method is widely used in ecological risk assessment to determine the chemical concentrations to protect aquatic species. Based on the species sensitivity distribution method using Korean indigenous aquatic biota, the hazardous concentration for 5% of biological species (HC 5 ) value calculated in this study was 44mg/L as total ammonia nitrogen (TAN). The value of the assessment factor was set at 2. Consequently, the criteria for ammonia were derived as 22mg/L at pH7 and 20°C. When the derived value was applied to the monitoring data nationwide, 0.51%, 0.09%, 0.18%, 0.20%, and 0.35% of the monitoring sites in Han River, Nakdong River, Geum River, Youngsan River, and lakes throughout the nation, respectively, exceeded this criteria. The Ministry of Environment in Korea has been considering introducing water quality standard of ammonia for protecting aquatic life. Therefore, our results can provide the basis for introducing the ammonia standard in Korea. Copyright © 2018 Elsevier B.V. All rights reserved.

A Water-Stable Proton-Conductive Barium(II)-Organic Framework for Ammonia Sensing at High Humidity.

PubMed

Guo, Kaimeng; Zhao, Lili; Yu, Shihang; Zhou, Wenyan; Li, Zifeng; Li, Gang

2018-06-07

In view of environmental protection and the need for early prediction of major diseases, it is necessary to accurately monitor the change of trace ammonia concentration in air or in exhaled breath. However, the adoption of proton-conductive metal-organic frameworks (MOFs) as smart sensors in this field is limited by a lack of ultrasensitive gas-detecting performance at high relative humidity (RH). Here, the pellet fabrication of a water-stable proton-conductive MOF, Ba( o-CbPhH 2 IDC)(H 2 O) 4 ] n (1) ( o-CbPhH 4 IDC = 2-(2-carboxylphenyl)-1 H-imidazole-4,5-dicarboxylic acid) is reported. The MOF 1 displays enhanced sensitivity and selectivity to NH 3 gas at high RHs (>85%) and 30 °C, and the sensing mechanism is suggested. The electrochemical impedance gas sensor fabricated by MOF 1 is a promising sensor for ammonia at mild temperature and high RHs.

Intensification of ammonia removal from waste water in biologically active zeolitic ion exchange columns.

PubMed

Almutairi, Azel; Weatherley, Laurence R

2015-09-01

The use of nitrification filters for the removal of ammonium ion from waste-water is an established technology deployed extensively in municipal water treatment, in industrial water treatment and in applications such as fish farming. The process involves the development of immobilized bacterial films on a solid packing support, which is designed to provide a suitable host for the film, and allow supply of oxygen to promote aerobic action. Removal of ammonia and nitrite is increasingly necessary to meet drinking water and discharge standards being applied in the US, Europe and other places. Ion-exchange techniques are also effective for removal of ammonia (as the ammonium ion) from waste water and have the advantage of fast start-up times compared to biological filtration which in some cases may take several weeks to be fully operational. Here we explore the performance of ion exchange columns in which nitrifying bacteria are cultivated, with the goal of a "combined" process involving simultaneous ion-exchange and nitrification, intensified by in-situ aeration with a novel membrane module. There were three experimental goals. Firstly, ion exchange zeolites were characterized and prepared for comparative column breakthrough studies for ammonia removal. Secondly effective in-situ aeration for promotion of nitrifying bacterial growth was studied using a number of different membranes including polyethersulfone (PES), polypropylene (PP), nylon, and polytetra-fluoroethylene (PTFE). Thirdly the breakthrough performance of ion exchange columns filled with zeolite in the presence of aeration and in the presence of nitrifying bacteria was determined to establish the influence of biomass, and aeration upon breakthrough during ammonium ion uptake. The methodology adopted included screening of two types of the naturally occuring zeolite clinoptilolite for effective ammonia removal in continuous ion-exchange columns. Next, the performance of fixed beds of clinoptilolite in the

Ammonia Leak Locator Study

NASA Technical Reports Server (NTRS)

Dodge, Franklin T.; Wuest, Martin P.; Deffenbaugh, Danny M.

1995-01-01

The thermal control system of International Space Station Alpha will use liquid ammonia as the heat exchange fluid. It is expected that small leaks (of the order perhaps of one pound of ammonia per day) may develop in the lines transporting the ammonia to the various facilities as well as in the heat exchange equipment. Such leaks must be detected and located before the supply of ammonia becomes critically low. For that reason, NASA-JSC has a program underway to evaluate instruments that can detect and locate ultra-small concentrations of ammonia in a high vacuum environment. To be useful, the instrument must be portable and small enough that an astronaut can easily handle it during extravehicular activity. An additional complication in the design of the instrument is that the environment immediately surrounding ISSA will contain small concentrations of many other gases from venting of onboard experiments as well as from other kinds of leaks. These other vapors include water, cabin air, CO2, CO, argon, N2, and ethylene glycol. Altogether, this local environment might have a pressure of the order of 10(exp -7) to 10(exp -6) torr. Southwest Research Institute (SwRI) was contracted by NASA-JSC to provide support to NASA-JSC and its prime contractors in evaluating ammonia-location instruments and to make a preliminary trade study of the advantages and limitations of potential instruments. The present effort builds upon an earlier SwRI study to evaluate ammonia leak detection instruments [Jolly and Deffenbaugh]. The objectives of the present effort include: (1) Estimate the characteristics of representative ammonia leaks; (2) Evaluate the baseline instrument in the light of the estimated ammonia leak characteristics; (3) Propose alternative instrument concepts; and (4) Conduct a trade study of the proposed alternative concepts and recommend promising instruments. The baseline leak-location instrument selected by NASA-JSC was an ion gauge.

1H, 15N and 13C NMR Assignments of Mouse Methionine Sulfoxide Reductase B2

PubMed Central

Breivik, Åshild S.; Aachmann, Finn L.; Sal, Lena S.; Kim, Hwa-Young; Del Conte, Rebecca; Gladyshev, Vadim N.; Dikiy, Alexander

2011-01-01

A recombinant mouse methionine-r-sulfoxide reductase 2 (MsrB2ΔS) isotopically labeled with 15N and 15N/13C was generated. We report here the 1H, 15N and 13C NMR assignments of the reduced form of this protein. PMID:19636904

49 CFR 172.411 - EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels..., EMERGENCY RESPONSE INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS Labeling § 172.411 EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label. (a) Except for size and color...

In vivo detection of 13C isotopomer turnover in the human brain by sequential infusion of 13C labeled substrates

NASA Astrophysics Data System (ADS)

Li, Shizhe; Zhang, Yan; Ferraris Araneta, Maria; Xiang, Yun; Johnson, Christopher; Innis, Robert B.; Shen, Jun

2012-05-01

This study demonstrates the feasibility of simultaneously detecting human brain metabolites labeled by two substrates infused in a sequential order. In vivo 13C spectra of carboxylic/amide carbons were acquired only during the infusion of the second substrate. This approach allowed dynamic detection of 13C labeling from two substrates with considerably different labeling patterns. [2-13C]glucose and [U-13C6]glucose were used to generate singlet and doublet signals of the same carboxylic/amide carbon atom, respectively. Because of the large one-bond 13C-13C homonuclear J coupling between a carboxylic/amide carbon and an aliphatic carbon (˜50 Hz), the singlet and doublet signals of the same carboxylic/amide carbon were well distinguished. The results demonstrated that different 13C isotopomer patterns could be simultaneously and distinctly measured in vivo in a clinical setting at 3 T.

WATER MASERS IN THE ANDROMEDA GALAXY. I. A SURVEY FOR WATER MASERS, AMMONIA, AND HYDROGEN RECOMBINATION LINES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darling, Jeremy; Gerard, Benjamin; Amiri, Nikta

We report the results of a Green Bank Telescope survey for water masers, ammonia (1, 1) and (2, 2), and the H66 α recombination line toward 506 luminous compact 24 μ m emitting regions in the Andromeda Galaxy (M31). We include the 206 sources observed in the Darling water maser survey for completeness. The survey was sensitive enough to detect any maser useful for ∼10 μ as yr{sup 1} astrometry. No new water masers, ammonia lines, or H66 α recombination lines were detected individually or in spectral stacks reaching rms noise levels of ∼3 mJy and ∼0.2 mJy, respectively, inmore » 3.1–3.3 km s{sup 1} channels. The lack of detections in individual spectra and in the spectral stacks is consistent with Galactic extrapolations. Contrary to previous assertions, there do not seem to be any additional bright water masers to be found in M31. The strong variability of water masers may enable new maser detections in the future, but variability may also limit the astrometric utility of known (or future) masers because flaring masers must also fade.« less

Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies.

PubMed

Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Fernández, Carlos; Legaz, Francisco; Quiñones, Ana

2016-01-01

Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively) fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L.) grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form) to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95%) ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency.

Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies

PubMed Central

Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Fernández, Carlos; Legaz, Francisco; Quiñones, Ana

2016-01-01

Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively) fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L.) grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form) to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95%) ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency. PMID:26982183

9 CFR 317.13 - Storage and distribution of labels and containers bearing official marks.

Code of Federal Regulations, 2010 CFR

2010-01-01

... containers bearing official marks. 317.13 Section 317.13 Animals and Animal Products FOOD SAFETY AND... General § 317.13 Storage and distribution of labels and containers bearing official marks. Labels, wrappers, and containers bearing any official marks, with or without the establishment number, may be...

Short-term effect of ammonia concentration and salinity on activity of ammonia oxidizing bacteria.

PubMed

Claros, J; Jiménez, E; Borrás, L; Aguado, D; Seco, A; Ferrer, J; Serralta, J

2010-01-01

A continuously aerated SHARON (single reactor high activity ammonia removal over nitrite) system has been operated to achieve partial nitritation. Two sets of batch experiments were carried out to study the effect of ammonia concentration and salinity on the activity of ammonia-oxidizing bacteria (AOB). Activity of AOB raised as free ammonia concentration was increased reaching its maximum value at 4.5 mg NH3-N l(-1). The half saturation constant for free ammonia was determined (K(NH3)=0.32 mg NH3-N l(-1)). Activity decreased at TAN (total ammonium-nitrogen) concentration over 2,000 mg NH4-N l(-1). No free ammonia inhibition was detected. The effect of salinity was studied by adding different concentrations of different salts to the biomass. No significant differences were observed between the experiments carried out with a salt containing or not containing NH4. These results support that AOB are inhibited by salinity, not by free ammonia. A mathematical expression to represent this inhibition is proposed. To compare substrate affinity and salinity inhibitory effect on different AOB populations, similar experiments were carried out with biomass from a biological nutrient removal pilot plant. The AOB activity reached its maximum value at 0.008 mg NH3-N l(-1) and decreased at TAN concentration over 400 mg NH4-N l(-1). These differences can be explained by the different AOB predominating species: Nitrosomonas europaea and N. eutropha in the SHARON biomass and Nitrosomonas oligotropha in the pilot plant.

Advances in PET myocardial perfusion imaging: F-18 labeled tracers.

PubMed

Rischpler, Christoph; Park, Min-Jae; Fung, George S K; Javadi, Mehrbod; Tsui, Benjamin M W; Higuchi, Takahiro

2012-01-01

Coronary artery disease and its related cardiac disorders represent the most common cause of death in the USA and Western world. Despite advancements in treatment and accompanying improvements in outcome with current diagnostic and therapeutic modalities, it is the correct assignment of these diagnostic techniques and treatment options which are crucial. From a diagnostic standpoint, SPECT myocardial perfusion imaging (MPI) using traditional radiotracers like thallium-201 chloride, Tc-99m sestamibi or Tc-99m tetrofosmin is the most utilized imaging technique. However, PET MPI using N-13 ammonia, rubidium-82 chloride or O-15 water is increasing in availability and usage as a result of the growing number of medical centers with new-generation PET/CT systems taking advantage of the superior imaging properties of PET over SPECT. The routine clinical use of PET MPI is still limited, in part because of the short half-life of conventional PET MPI tracers. The disadvantages of these conventional PET tracers include expensive onsite production and inconvenient on-scanner tracer administration making them unsuitable for physical exercise stress imaging. Recently, two F-18 labeled radiotracers with longer radioactive half-lives than conventional PET imaging agents have been introduced. These are flurpiridaz F 18 (formerly known as F-18 BMS747158-02) and F-18 fluorobenzyltriphenylphosphonium. These longer half-life F-18 labeled perfusion tracers can overcome the production and protocol limitations of currently used radiotracers for PET MPI.

Stable isotope probing of acetate fed anaerobic batch incubations shows a partial resistance of acetoclastic methanogenesis catalyzed by Methanosarcina to sudden increase of ammonia level.

PubMed

Hao, Liping; Lü, Fan; Mazéas, Laurent; Desmond-Le Quéméner, Elie; Madigou, Céline; Guenne, Angéline; Shao, Liming; Bouchez, Théodore; He, Pinjing

2015-02-01

Ammonia inhibition represents a major operational issue for anaerobic digestion. In order to refine our understanding of the terminal catabolic steps in thermophilic anaerobic digestion under ammonia stress, we studied batch thermophilic acetate fed experiments at low (0.26 g L(-1)) and high (7.00 g L(-1)) Total Ammonia Nitrogen concentrations (TAN). Although methane production started immediately for all incubations and resulted in methane yields close to stoichiometric expectations, a 62-72% decrease of methanogenic rate was observed throughout the incubation at 7.00 g L(-1) of TAN compared to 0.26 g L(-1). Stable Isotope Probing analysis of active microbial communities in (13)C-acetate fed experiments coupled to automated ribosomal intergenic spacer analysis and 16S rDNA pyrotag sequencing confirmed that microbial communities were similar for both TAN conditions. At both TAN levels, the (13)C-labeled bacterial community was mainly affiliated to Clostridia-relatives, with OPB54 bacteria being the most abundant sequence in the heavy DNA 16S rDNA pyrotag library. Sequences closely related to Methanosarcina thermophila were also abundantly retrieved in the heavy DNA fractions, showing that this methanogen was still actively assimilating labeled carbon from acetate at free ammonia nitrogen concentrations up to 916 mg L(-1). Stable isotopic signature analysis of biogas, measured in unlabeled acetate fed experiments that were conducted in parallel, confirmed that acetoclastic methanogenic pathway was dominant at both ammonia concentrations. Our work demonstrates that, besides the syntrophic acetate oxidation pathway, acetoclastic methanogenesis catalyzed by Methanosarcina can also play a major role in methane production at high ammonia levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tracing photosynthetic carbon in leaves with nanoSIMS after 13CO2 labelling

NASA Astrophysics Data System (ADS)

Dannoura, Masako; Takeuchi, Miyuki; Kominami, Yuji; Takanashi, Satoru; Kenichi, Yoshimura; Ataka, Mioko

2015-04-01

To understand the carbon allocation of the tree and forest ecosystem, it is important to consider the residence time of carbon in different pools at suitable time scales. For example the carbon used for respiration will stay a few minutes to a few days in the tree, the carbon used for storage or structure of leaves will stay months to years, and the carbon used for wood structure, it will stay over the whole lifespan of the tree. The leaves are the entrance of carbon in trees where it can be used for foliage growth and maintenance or exported to the other organs or the other forest ecosystem compartments. Tracing carbon isotope using NanoSIMS technique is one of useful methods to estimate where and how long the carbon stay in the tree organs. In this study, 13CO2 pulse labelling were conducted and 13C was measured by IRMS to see the amount of C remaining in the leaves with time.NanoSIMS was used to localize where the labelled C remained within the leaf tissue. Twice labelling were done on branches of Quercus serrata at FFPRI(Forest and Forest Products research Institute) in Kyoto, Japan. The first labelling was in 30 April 2012 when the leaves start flushing and the second one was in 29 May 2012 when the leaves were completely deployed. For both labelling experiment, one branch was selected and covered with transparent plastic bag. CO2 concentration was recorded with IRGA and air temperature inside the chamber was monitored. Then 13CO2 was injected into the bag, and after 1 hour, the bag was removed and the branch was again exposed to ambient air. Leaves were collected before and 10-12 times after labelling and their isotope compositions were measured by IRMS. The leaf collected just after labelling and 6 days after labelling were used for NanoSIMS observation. Samples for nanoSIMS were preserved in glutaraldehyde and then embed in epoxy resin. The sliced sample were placed on the silicon wafer and observed by NanoSIMS 50L(Cameca, France). The 13C was highest just

Assessment of N2O emission from a photobioreactor treating ammonia-rich swine wastewater digestate.

PubMed

Mezzari, Melissa P; da Silva, Márcio L B; Nicoloso, Rodrigo S; Ibelli, Adriana M G; Bortoli, Marcelo; Viancelli, Aline; Soares, Hugo M

2013-12-01

This study investigated the interactions between naturally occurring bacteria and the microalgae Chlorella vulgaris within a lab scale photobioreactor treating ammonia-rich swine wastewater digestate effluent. Nitrification and denitrification were assessed by targeting ammonia monoxygenases (amoA), nitrate (narG), nitrite (nirS), nitric oxide (norB) and nitrous oxide (nosZ) reductases genes. Oxygen produced from microalgae photosynthesis stimulated nitrification. Under limiting carbon availability (i.e., <1.44 for mg TOC/mg NO2-N and 1.72 for mg TOC/mg NO3-N), incomplete denitrification led to accumulation of NO2 and NO3. Significant N2O emission (up to 118 μg N2O-N) was linked to NO2 metabolism in Chlorella. The addition of acetate as external carbon source recovered heterotrophic denitrification activity suppressing N2O emission. Effluent methane concentrations trapped within photobioreactor was removed concomitantly with ammonia. Overall, closed photobioreactors can be built to effectively remove nitrogen and mitigate simultaneously greenhouse gases emissions that would occur otherwise in open microalgae-based wastewater treatment systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Net summertime emission of ammonia from corn and triticale fields

NASA Astrophysics Data System (ADS)

Richter, Undine; Smith, Jeremy; Brümmer, Christian

2016-04-01

Recent advancements in laser spectrometry offer new opportunities to investigate ecosystem-atmosphere exchange of environmentally relevant trace gases. In this study, we used a quantum cascade laser (QCL) absorption spectrometer to continuously measure high-frequency concentrations of ammonia and the net exchange between an agricultural site and the atmosphere based on the eddy-covariance approach. The footprint was split into two main sectors, one planted with corn (Zea mays) and the other one with triticale. Ammonia concentrations were highly variable between 2 and almost 100 ppb with an average value of 8.1 ppb during the observation period from April to September 2015. While both deposition and emission of ammonia was observed, the total campaign exchange resulted in a loss of 3.3 kg NH3-N ha-1. Highest average emission fluxes of 65 ng N m-2 s-1 were recorded after fertilization at the beginning of the campaign in April and May. Afterwards the exchange of ammonia with the atmosphere decreased considerably, but the site remained on average a consistent source with sporadic lower peaks and an average flux of 13 ng N m-2 s-1. While management in the form of fertilization was the main driver for ammonia concentration and exchange at the site, biophysical controls from temperature, wind regime, and surface wetness are also presented.

Mass Isotopomer Analysis of Metabolically Labeled Nucleotide Sugars and N- and O-Glycans for Tracing Nucleotide Sugar Metabolisms*

PubMed Central

Nakajima, Kazuki; Ito, Emi; Ohtsubo, Kazuaki; Shirato, Ken; Takamiya, Rina; Kitazume, Shinobu; Angata, Takashi; Taniguchi, Naoyuki

2013-01-01

Nucleotide sugars are the donor substrates of various glycosyltransferases, and an important building block in N- and O-glycan biosynthesis. Their intercellular concentrations are regulated by cellular metabolic states including diseases such as cancer and diabetes. To investigate the fate of UDP-GlcNAc, we developed a tracing method for UDP-GlcNAc synthesis and use, and GlcNAc utilization using 13C6-glucose and 13C2-glucosamine, respectively, followed by the analysis of mass isotopomers using LC-MS. Metabolic labeling of cultured cells with 13C6-glucose and the analysis of isotopomers of UDP-HexNAc (UDP-GlcNAc plus UDP-GalNAc) and CMP-NeuAc revealed the relative contributions of metabolic pathways leading to UDP-GlcNAc synthesis and use. In pancreatic insulinoma cells, the labeling efficiency of a 13C6-glucose motif in CMP-NeuAc was lower compared with that in hepatoma cells. Using 13C2-glucosamine, the diversity of the labeling efficiency was observed in each sugar residue of N- and O-glycans on the basis of isotopomer analysis. In the insulinoma cells, the low labeling efficiencies were found for sialic acids as well as tri- and tetra-sialo N-glycans, whereas asialo N-glycans were found to be abundant. Essentially no significant difference in secreted hyaluronic acids was found among hepatoma and insulinoma cell lines. This indicates that metabolic flows are responsible for the low sialylation in the insulinoma cells. Our strategy should be useful for systematically tracing each stage of cellular GlcNAc metabolism. PMID:23720760

Production of isotopically labeled standards from a uniformly labeled precursor for quantitative volatile metabolomic studies.

PubMed

Gómez-Cortés, Pilar; Brenna, J Thomas; Sacks, Gavin L

2012-06-19

Optimal accuracy and precision in small-molecule profiling by mass spectrometry generally requires isotopically labeled standards chemically representative of all compounds of interest. However, preparation of mixed standards from commercially available pure compounds is often prohibitively expensive and time-consuming, and many labeled compounds are not available in pure form. We used a single-prototype uniformly labeled [U-(13)C]compound to generate [U-(13)C]-labeled volatile standards for use in subsequent experimental profiling studies. [U-(13)C]-α-Linolenic acid (18:3n-3, ALA) was thermally oxidized to produce labeled lipid degradation volatiles which were subsequently characterized qualitatively and quantitatively. Twenty-five [U-(13)C]-labeled volatiles were identified by headspace solid-phase microextraction-gas chromatography/time-of-flight mass spectrometry (HS-SPME-GC/TOF-MS) by comparison of spectra with unlabeled volatiles. Labeled volatiles were quantified by a reverse isotope dilution procedure. Using the [U-(13)C]-labeled standards, limits of detection comparable to or better than those of previous HS-SPME reports were achieved, 0.010-1.04 ng/g. The performance of the [U-(13)C]-labeled volatile standards was evaluated using a commodity soybean oil (CSO) oxidized at 60 °C from 0 to 15 d. Relative responses of n-decane, an unlabeled internal standard otherwise absent from the mixture, and [U-(13)C]-labeled oxidation products changed by up to 8-fold as the CSO matrix was oxidized, demonstrating that reliance on a single standard in volatile profiling studies yields inaccurate results due to changing matrix effects. The [U-(13)C]-labeled standard mixture was used to quantify 25 volatiles in oxidized CSO and low-ALA soybean oil with an average relative standard deviation of 8.5%. Extension of this approach to other labeled substrates, e.g., [U-(13)C]-labeled sugars and amino acids, for profiling studies should be feasible and can dramatically improve

Acute toxicity of copper, ammonia, and chlorine to glochidia and juveniles of freshwater mussels (Unionidae)

USGS Publications Warehouse

Wang, N.; Ingersoll, C.G.; Hardesty, D.K.; Ivey, C.D.; Kunz, J.L.; May, T.W.; Dwyer, F.J.; Roberts, A.D.; Augspurger, T.; Kane, C.M.; Neves, R.J.; Barnhart, M.C.

2007-01-01

The objective of the present study was to determine acute toxicity of copper, ammonia, or chlorine to larval (glochidia) and juvenile mussels using the recently published American Society for Testing and Materials (ASTM) Standard guide for conducting laboratory toxicity tests with freshwater mussels. Toxicity tests were conducted with glochidia (24- to 48-h exposures) and juveniles (96-h exposures) of up to 11 mussel species in reconstituted ASTM hard water using copper, ammonia, or chlorine as a toxicant. Copper and ammonia tests also were conducted with five commonly tested species, including cladocerans (Daphnia magna and Ceriodaphnia dubia; 48-h exposures), amphipod (Hyalella azteca; 48-h exposures), rainbow trout (Oncorhynchus mykiss; 96-h exposures), and fathead minnow (Pimephales promelas; 96-h exposures). Median effective concentrations (EC50s) for commonly tested species were >58 ??g Cu/L (except 15 ??g Cu/L for C. dubia) and >13 mg total ammonia N/L, whereas the EC50s for mussels in most cases were 40 ??g/L and above the FAV in the WQC for chlorine. The results indicate that the early life stages of mussels generally were more sensitive to copper and ammonia than other organisms and that, including mussel toxicity data in a revision to the WQC, would lower the WQC for copper or ammonia. Furthermore, including additional mussel data in 2007 WQC for copper based on biotic ligand model would further lower the WQC. ?? 2007 SETAC.

49 CFR 172.411 - EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false EXPLOSIVE 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 labels..., 1.2, 1.3, 1.4, 1.5 and 1.6 labels, and EXPLOSIVE Subsidiary label. (a) Except for size and color....5 and EXPLOSIVE 1.6 labels must be as follows: EXPLOSIVE 1.4: EC02MR91.016 EXPLOSIVE 1.5: EC02MR91...

An evaluation of the influence of substrate on the response of juvenile freshwater mussels (fatmucket, Lampsilis siliquoidea) in acute water exposures to ammonia

USGS Publications Warehouse

Miao, J.; Barnhart, M.C.; Brunson, E.L.; Hardesty, D.K.; Ingersoll, C.G.; Wang, N.

2010-01-01

Acute 96-h ammonia toxicity to three-month-old juvenile mussels (Lampsilis siliquoidea) was evaluated in four treatments (water-only, water-only with feeding, water and soil, and water and sand) using an exposure unit designed to maintain consistent pH and ammonia concentrations in overlying water and in pore water surrounding the substrates. Median effect concentrations (EC50s) for total ammonia nitrogen in the four treatments ranged from 5.6 to 7.7mg/L and median lethal concentrations (LC50s) ranged from 7.0 to 11mg/L at a mean pH of 8.4. Similar EC50s or LC50s with overlapping 95% confidence intervals among treatments indicated no influence of substrate on the response of mussels in acute exposures to ammonia. ?? 2010 SETAC.

Adsorption of ammonia at GaN(0001) surface in the mixed ammonia/hydrogen ambient - a summary of ab initio data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kempisty, Paweł; Krukowski, Stanisław; Interdisciplinary Centre for Materials Modelling, Warsaw University, Pawińskiego 5a, 02-106 Warsaw

Adsorption of ammonia at NH{sub 3}/NH{sub 2}/H-covered GaN(0001) surface was analyzed using results of ab initio calculations. The whole configuration space of partially NH{sub 3}/NH{sub 2}/H-covered GaN(0001) surface was divided into zones of differently pinned Fermi level: at the Ga broken bond state for dominantly bare surface (region I), at the valence band maximum (VBM) for NH{sub 2} and H-covered surface (region II), and at the conduction band minimum (CBM) for NH{sub 3}-covered surface (region III). The electron counting rule (ECR) extension was formulated for the case of adsorbed molecules. The extensive ab intio calculations show the validity of themore » ECR in case of all mixed H-NH{sub 2}-NH{sub 3} coverages for the determination of the borders between the three regions. The adsorption was analyzed using the recently identified dependence of the adsorption energy on the charge transfer at the surface. For region I ammonia adsorbs dissociatively, disintegrating into a H adatom and a HN{sub 2} radical for a large fraction of vacant sites, while for region II adsorption of ammonia is molecular. The dissociative adsorption energy strongly depends on the Fermi level at the surface (pinned) and in the bulk (unpinned) while the molecular adsorption energy is determined by bonding to surface only, in accordance to the recently published theory. Adsorption of Ammonia in region III (Fermi level pinned at CBM) leads to an unstable configuration both molecular and dissociative, which is explained by the fact that broken Ga-bonds are doubly occupied by electrons. The adsorbing ammonia brings 8 electrons to the surface, necessitating the transfer of these two electrons from the Ga broken bond state to the Fermi level. This is an energetically costly process. Adsorption of ammonia at H-covered site leads to the creation of a NH{sub 2} radical at the surface and escape of H{sub 2} molecule. The process energy is close to 0.12 eV, thus not large, but the direct

Nitrogen losses and greenhouse gas emissions under different N and water management in a subtropical double-season rice cropping system.

PubMed

Liang, Kaiming; Zhong, Xuhua; Huang, Nongrong; Lampayan, Rubenito M; Liu, Yanzhuo; Pan, Junfeng; Peng, Bilin; Hu, Xiangyu; Fu, Youqiang

2017-12-31

Nitrogen non-point pollution and greenhouse gas (GHG) emission are major challenges in rice production. This study examined options for both economic and environmental sustainability through optimizing water and N management. Field experiments were conducted to examine the crop yields, N use efficiency (NUE), greenhouse gas emissions, N losses under different N and water management. There were four treatments: zero N input with farmer's water management (N0), farmer's N and water management (FP), optimized N management with farmer's water management (OPT N ) and optimized N management with alternate wetting and drying irrigation (OPT N +AWD). Grain yields in OPT N and OPT N +AWD treatments increased by 13.0-17.3% compared with FP. Ammonia volatilization (AV) was the primary pathway for N loss for all treatments and accounted for over 50% of the total losses. N losses mainly occurred before mid-tillering. N losses through AV, leaching and surface runoff in OPT N were reduced by 18.9-51.6% compared with FP. OPT N +AWD further reduced N losses from surface runoff and leaching by 39.1% and 6.2% in early rice season, and by 46.7% and 23.5% in late rice season, respectively, compared with OPT N . The CH 4 emissions in OPT N +AWD were 20.4-45.4% lower than in OPT N and FP. Total global warming potential of CH 4 and N 2 O was the lowest in OPT N +AWD. On-farm comparison confirmed that N loss through runoff in OPT N +AWD was reduced by over 40% as compared with FP. OPT N and OPT N +AWD significantly increased grain yield by 6.7-13.9%. These results indicated that optimizing water and N management can be a simple and effective approach for enhancing yield with reduced environmental footprints. Copyright © 2017. Published by Elsevier B.V.

Crystal Structure of an Ammonia-Permeable Aquaporin

PubMed Central

Kirscht, Andreas; Kaptan, Shreyas S.; Bienert, Gerd Patrick; Chaumont, François; Nissen, Poul; de Groot, Bert L.; Kjellbom, Per; Gourdon, Pontus; Johanson, Urban

2016-01-01

Aquaporins of the TIP subfamily (Tonoplast Intrinsic Proteins) have been suggested to facilitate permeation of water and ammonia across the vacuolar membrane of plants, allowing the vacuole to efficiently sequester ammonium ions and counteract cytosolic fluctuations of ammonia. Here, we report the structure determined at 1.18 Å resolution from twinned crystals of Arabidopsis thaliana aquaporin AtTIP2;1 and confirm water and ammonia permeability of the purified protein reconstituted in proteoliposomes as further substantiated by molecular dynamics simulations. The structure of AtTIP2;1 reveals an extended selectivity filter with the conserved arginine of the filter adopting a unique unpredicted position. The relatively wide pore and the polar nature of the selectivity filter clarify the ammonia permeability. By mutational studies, we show that the identified determinants in the extended selectivity filter region are sufficient to convert a strictly water-specific human aquaporin into an AtTIP2;1-like ammonia channel. A flexible histidine and a novel water-filled side pore are speculated to deprotonate ammonium ions, thereby possibly increasing permeation of ammonia. The molecular understanding of how aquaporins facilitate ammonia flux across membranes could potentially be used to modulate ammonia losses over the plasma membrane to the atmosphere, e.g., during photorespiration, and thereby to modify the nitrogen use efficiency of plants. PMID:27028365

Oligonucleotide labeling methods. 3. Direct labeling of oligonucleotides employing a novel, non-nucleosidic, 2-aminobutyl-1,3-propanediol backbone.

PubMed Central

Nelson, P S; Kent, M; Muthini, S

1992-01-01

Novel CE-phosphoramidite (7a-e) and CPG (8a, c, d, e) reagents have been prepared from a unique 2-aminobutyl-1,3-propanediol backbone. The reagents have been used to directly label oligonucleotides with fluorescein, acridine, and biotin via automated DNA synthesis. The versatile 2-aminobutyl-1,3-propanediol backbone allows for labeling at any position (5', internal, and 3') during solid phase oligonucleotide synthesis. Multiple labels can be achieved by repetitive coupling cycles. Furthermore, the 3-carbon atom internucleotide phosphate distance is retained when inserted internally. Using this method, individual oligonucleotides possessing two and three different reporter molecules have been prepared. PMID:1475185

Mathematical Modeling of Ammonia Electro-Oxidation on Polycrystalline Pt Deposited Electrodes

NASA Astrophysics Data System (ADS)

Diaz Aldana, Luis A.

The ammonia electrolysis process has been proposed as a feasible way for electrochemical generation of fuel grade hydrogen (H2). Ammonia is identified as one of the most suitable energy carriers due to its high hydrogen density, and its safe and efficient distribution chain. Moreover, the fact that this process can be applied even at low ammonia concentration feedstock opens its application to wastewater treatment along with H 2 co-generation. In the ammonia electrolysis process, ammonia is electro-oxidized in the anode side to produce N2 while H2 is evolved from water reduction in the cathode. A thermodynamic energy requirement of just five percent of the energy used in hydrogen production from water electrolysis is expected from ammonia electrolysis. However, the absence of a complete understanding of the reaction mechanism and kinetics involved in the ammonia electro-oxidation has not yet allowed the full commercialization of this process. For that reason, a kinetic model that can be trusted in the design and scale up of the ammonia electrolyzer needs to be developed. This research focused on the elucidation of the reaction mechanism and kinetic parameters for the ammonia electro-oxidation. The definition of the most relevant elementary reactions steps was obtained through the parallel analysis of experimental data and the development of a mathematical model of the ammonia electro-oxidation in a well defined hydrodynamic system, such as the rotating disk electrode (RDE). Ammonia electro-oxidation to N 2 as final product was concluded to be a slow surface confined process where parallel reactions leading to the deactivation of the catalyst are present. Through the development of this work it was possible to define a reaction mechanism and values for the kinetic parameters for ammonia electro-oxidation that allow an accurate representation of the experimental observations on a RDE system. Additionally, the validity of the reaction mechanism and kinetic parameters

Biosynthetically directed fractional 13C labeling facilitates identification of Phe and Tyr aromatic signals in proteins.

PubMed

Jacob, Jaison; Louis, John M; Nesheiwat, Issa; Torchia, Dennis A

2002-11-01

Analysis of 2D [(13)C,(1)H]-HSQC spectra of biosynthetic fractionally (13)C labeled proteins is a reliable, straightforward means to obtain stereospecific assignments of Val and Leu methyl sites in proteins. Herein we show that the same fractionally labeled protein sample facilitates observation and identification of Phe and Tyr aromatic signals. This is the case, in part, because the fractional (13)C labeling yields aromatic rings in which some of the (13)C-(13)C J-couplings, present in uniformly labeled samples, are absent. Also, the number of homonuclear J-coupling partners differs for the delta-, epsilon- and zeta-carbons. This enabled us to vary their signal intensities in distinctly different ways by appropriately setting the (13)C constant-time period in 2D [(13)C,(1)H]-HSQC spectra. We illustrate the application of this approach to an 18 kDa protein, c-VIAF, a modulator of apoptosis. In addition, we show that cancellation of the aromatic (13)C CSA and (13)C-(1)H dipolar interactions can be fruitfully utilized in the case of the fractionally labeled sample to obtain high resolution (13)C constant-time spectra with good sensitivity.

Ammonia gas permeability of meat packaging materials.

PubMed

Karim, Faris; Hijaz, Faraj; Kastner, Curtis L; Smith, J Scott

2011-03-01

Meat products are packaged in polymer films designed to protect the product from exterior contaminants such as light, humidity, and harmful chemicals. Unfortunately, there is almost no data on ammonia permeability of packaging films. We investigated ammonia permeability of common meat packaging films: low-density polyethylene (LDPE; 2.2 mil), multilayer polyolefin (MLP; 3 mil), and vacuum (V-PA/PE; 3 mil, 0.6 mil polyamide/2.4 mil polyethylene). The films were fabricated into 10 × 5 cm pouches and filled with 50 mL deionized water. Pouches were placed in a plexiglass enclosure in a freezer and exposed to 50, 100, 250, or 500 ppm ammonia gas for 6, 12, 24, and 48 h at -17 ± 3 °C and 21 ± 3 °C. At freezing temperatures, no ammonia residues were detected and no differences in pH were found in the water. At room temperature, ammonia levels and pH of the water increased significantly (P < 0.05) with increasing exposure times and ammonia concentrations. Average ammonia levels in the water were 7.77 ppm for MLP, 5.94 ppm for LDPE, and 0.89 ppm for V-PA/PE at 500 ppm exposure for 48 h at 21 ± 3 °C. Average pH values were 8.64 for MLP, 8.38 for LDPE, and 7.23 for V-PA/PE (unexposed ranged from 5.49 to 6.44) at 500 ppm exposure for 48 h. The results showed that temperature influenced ammonia permeability. Meat packaging materials have low ammonia permeability and protect meat products exposed to ammonia leaks during frozen storage.

Study of removal of ammonia from urine vapor by dual catalyst

NASA Technical Reports Server (NTRS)

Budininkas, P.

1976-01-01

The feasibility of ammonia removal from urine vapor by a low temperature dual-catalyst system was investigated. The process is based on the initial catalytic oxidation of ammonia present in urine vapor to nitrogen and nitrous oxide, followed by a catalytic decomposition of the nitrous oxide formed into its elements. The most active catalysts for the oxidation of ammonia and for the decomposition of N2O, identified in screening tests, were then combined into dual catalyst systems and tested to establish their overall efficiencies for the removal of ammonia from artificial gas mixtures. Dual catalyst systems capable of ammonia removal from the artificial gas mixtures were then tested with the actual urine vapor produced by boiling untreated urine. A suitable dual catalyst bed arrangement was found that achieved the removal of ammonia and organic carbon, and recovered water of good quality from urine vapor.

Distribution and abundance of archaeal and bacterial ammonia oxidizers in the sediments of the Dongjiang River, a drinking water supply for Hong Kong.

PubMed

Sun, Wei; Xia, Chunyu; Xu, Meiying; Guo, Jun; Wang, Aijie; Sun, Guoping

2013-01-01

Ammonia-oxidizing archaea (AOA) and bacteria (AOB) play important roles in nitrification. However, limited information about the characteristics of AOA and AOB in the river ecosystem is available. The distribution and abundance of AOA and AOB in the sediments of the Dongjiang River, a drinking water source for Hong Kong, were investigated by clone library analysis and quantitative real-time PCR. Phylogenetic analysis showed that Group 1.1b- and Group 1.1b-associated sequences of AOA predominated in sediments with comparatively high carbon and nitrogen contents (e.g. total carbon (TC) >13 g kg(-1) sediment, NH4(+)-N >144 mg kg(-1) sediment), while Group 1.1a- and Group 1.1a-associated sequences were dominant in sediments with opposite conditions (e.g. TC <4 g kg(-1) sediment, NH4(+)-N <93 mg kg(-1) sediment). Although Nitrosomonas- and Nitrosospira-related sequences of AOB were detected in the sediments, nearly 70% of the sequences fell into the Nitrosomonas-like B cluster, suggesting similar sediment AOB communities along the river. Higher abundance of AOB than AOA was observed in almost all of the sediments in the Dongjiang River, while significant correlations were only detected between the distribution of AOA and the sediment pH and TC, which suggested that AOA responded more sensitively than AOB to variations of environmental factors. These results extend our knowledge about the environmental responses of ammonia oxidizers in the river ecosystem.

13C nuclear magnetic resonance and gas chromatography-mass spectrometry studies of carbon metabolism in the actinomycin D producer Streptomyces parvulus by use of 13C-labeled precursors.

PubMed Central

Inbar, L; Lapidot, A

1991-01-01

enrichment and isotopomer population, measured by nuclear magnetic resonance and gas chromatography-mass spectrometry, of the actinomycin D peptide ring enabled us to specify the origins of the five amino acids of actinomycin D. Threonine and proline exhibited isotopomer populations similar to that of the extracellular L-[13C]glutamate, indicating that protein catabolism is the origin of their 13C label, whereas the isotopomer populations of sarcosine and N-methylvaline were similar to those of the new intracellular pool of S. parvulus that originated from D-[U-13C]fructose during the production of actinomycin D. PMID:1744035

Isotope signatures of N2O emitted from vegetable soil: Ammonia oxidation drives N2O production in NH4(+)-fertilized soil of North China.

PubMed

Zhang, Wei; Li, Yuzhong; Xu, Chunying; Li, Qiaozhen; Lin, Wei

2016-07-08

Nitrous oxide (N2O) is a potent greenhouse gas. In North China, vegetable fields are amended with high levels of N fertilizer and irrigation water, which causes massive N2O flux. The aim of this study was to determine the contribution of microbial processes to N2O production and characterize isotopic signature effects on N2O source partitioning. We conducted a microcosm study that combined naturally abundant isotopologues and gas inhibitor techniques to analyze N2O flux and its isotopomer signatures [δ(15)N(bulk), δ(18)O, and SP (intramolecular (15)N site preference)] that emitted from vegetable soil after the addition of NH4(+) fertilizers. The results show that ammonia oxidation is the predominant process under high water content (70% water-filled pore space), and nitrifier denitrification contribution increases with increasing N content. δ(15)N(bulk) and δ(18)O of N2O may not provide information about microbial processes due to great shifts in precursor signatures and atom exchange, especially for soil treated with NH4(+) fertilizer. SP and associated two end-member mixing model are useful to distinguish N2O source and contribution. Further work is needed to explore isotopomer signature stability to improve N2O microbial process identification.

Biochar type and factors affecting N transformation, ammonia volatilization, and nitrous oxide emissions

USDA-ARS?s Scientific Manuscript database

Soil amendment with biochar has shown the potential to improve nitrogen (N) availability for plant uptake and reduce environmental losses via ammonia (NH3) and nitrous oxide (N2O) emissions. There are still many unknowns on how biochar type and soil conditions affect N dynamics and processes associa...

Effects of Glycine, Water, Ammonia, and Ammonium Bicarbonate on the Oligomerization of Methionine

NASA Astrophysics Data System (ADS)

Huang, Rui; Furukawa, Yoshihiro; Otake, Tsubasa; Kakegawa, Takeshi

2017-06-01

The abiotic oligomerization of amino acids may have created primordial, protein-like biological catalysts on the early Earth. Previous studies have proposed and evaluated the potential of diagenesis for the amino acid oligomerization, simulating the formation of peptides that include glycine, alanine, and valine, separately. However, whether such conditions can promote the formation of peptides composed of multiple amino acids remains unclear. Furthermore, the chemistry of pore water in sediments should affect the oligomerization and degradation of amino acids and oligomers, but these effects have not been studied extensively. In this study, we investigated the effects of water, ammonia, ammonium bicarbonate, pH, and glycine on the oligomerization and degradation of methionine under high pressure (150 MPa) and high temperature conditions (175 °C) for 96 h. Methionine is more difficult to oligomerize than glycine and methionine dimer was formed in the incubation of dry powder of methionine. Methionine oligomers as long as trimers, as well as methionylglycine and glycylmethionine, were formed under every condition with these additional compounds. Among the compounds tested, the oligomerization reaction rate was accelerated by the presence of water and by an increase in pH. Ammonia also increased the oligomerization rate but consumed methionine by side reactions and resulted in the rapid degradation of methionine and its peptides. Similarly, glycine accelerated the oligomerization rate of methionine and the degradation of methionine, producing water, ammonia, and bicarbonate through its decomposition. With Gly, heterogeneous dimers (methionylglycine and glycylmethionine) were formed in greater amounts than with other additional compounds although smaller amount of these heterogeneous dimers were formed with other additional compounds. These results suggest that accelerated reaction rates induced by water and co-existing reactive compounds promote the oligomerization

Ammonia concentration determines differential growth of ammonia-oxidising archaea and bacteria in soil microcosms.

PubMed

Verhamme, Daniel T; Prosser, James I; Nicol, Graeme W

2011-06-01

The first step of nitrification, oxidation of ammonia to nitrite, is performed by both ammonia-oxidising archaea (AOA) and ammonia-oxidising bacteria (AOB) in soil, but their relative contributions to ammonia oxidation and existence in distinct ecological niches remain to be determined. To determine whether available ammonia concentration has a differential effect on AOA and AOB growth, soil microcosms were incubated for 28 days with ammonium at three concentrations: native (control), intermediate (20 μg NH(4)(+)-N per gram of soil) and high (200 μg NH(4)(+)-N per gram of soil). Quantitative PCR demonstrated growth of AOA at all concentrations, whereas AOB growth was prominent only at the highest concentration. Similarly, denaturing gradient gel electrophoresis (DGGE) analysis revealed changes in AOA communities at all ammonium concentrations, whereas AOB communities changed significantly only at the highest ammonium concentration. These results provide evidence that ammonia concentration contributes to the definition of distinct ecological niches of AOA and AOB in soil.

Ammonia concentration determines differential growth of ammonia-oxidising archaea and bacteria in soil microcosms

PubMed Central

Verhamme, Daniel T; Prosser, James I; Nicol, Graeme W

2011-01-01

The first step of nitrification, oxidation of ammonia to nitrite, is performed by both ammonia-oxidising archaea (AOA) and ammonia-oxidising bacteria (AOB) in soil, but their relative contributions to ammonia oxidation and existence in distinct ecological niches remain to be determined. To determine whether available ammonia concentration has a differential effect on AOA and AOB growth, soil microcosms were incubated for 28 days with ammonium at three concentrations: native (control), intermediate (20 μg NH4+-N per gram of soil) and high (200 μg NH4+-N per gram of soil). Quantitative PCR demonstrated growth of AOA at all concentrations, whereas AOB growth was prominent only at the highest concentration. Similarly, denaturing gradient gel electrophoresis (DGGE) analysis revealed changes in AOA communities at all ammonium concentrations, whereas AOB communities changed significantly only at the highest ammonium concentration. These results provide evidence that ammonia concentration contributes to the definition of distinct ecological niches of AOA and AOB in soil. PMID:21228892

Scavenging of ammonia by raindrops in Saturn's great storm clouds

NASA Astrophysics Data System (ADS)

Delitsky, M. L.; Baines, Kevin

2016-10-01

Observations of the great Saturn storms of 2010-2011 by Cassini instruments showed a very large depletion in atmospheric ammonia. While dynamics will play a role, the very high solubility of ammonia in water may be another important contributor to ammonia depletion in storms. Ammonia exists in Earth's atmosphere and rainstorms dissolve ammonia to a great degree, leaving almost no NH3 in the atmosphere. Studies by Elperin et al (2011, 2013) show that scavenging of ammonia is greatest as a rainstorm starts and lessens as raindrops fall, tapering off to almost zero by the time the rain reaches the ground (Elperin et al 2009). Ammonia is reaching saturation as it dissolves in the aqueous solution. As concentration increases, NH3 is then converted to aqueous species (NH3)x.(H2O)y (Max and Chapados 2013).Ammonia has the highest solubility in water compared to all other gases in the Saturn atmosphere. The Henry's Law constant for NH3 in water is 60 M/atm at 25 C. For H2S, it is 0.001 M/atm. In Saturn storms, it is "raining UP": As water-laden storm clouds convectively rise, ammonia gas will be scavenged and go into solution to a great degree, whilst all the other gases remain mostly in the gas phase. Aqueous ammonia acts as an antifreeze: if ammonia is dissolved in water cloud droplets to the limit of its solubility, as water droplets rise, they can stay liquid (and continue to scavenge NH3) to well below their normal freezing point of 0 Celsius (273 K). The freezing point for a 30 wt % water-ammonia solution is ~189 K. The pressure level where T = 189 K is at 2.8 bars. The normal freezing point of water occurs at the 9 bar pressure level in Saturn's atmosphere. 2.8 bars occurs at the -51 km altitude (below the 1 bar level). 9 bars is at the -130 km level: a difference of 79 km. A water droplet containing 30 wt% NH3 can move upwards from 9 bars to 2.8 bars (79 km) and still remain liquid, only freezing above that altitude. Calculations by the E-AIM model show that ammonia

Synthesis of 13 C-labeled 5-Aminoimidazole-4-carboxamide-1-β-D-[13 C5 ] ribofuranosyl 5'-monophosphate.

PubMed

Zarkin, Allison K; Elkins, Phyllis D; Gilbert, Amanda; Jester, Teresa L; Seltzman, Herbert H

2018-06-14

5-Aminoimidazole-4-carboxamide-1-β-D-[ 13 C 5 ] ribofuranosyl 5'-monophosphate ([ 13 C 5 ribose] AICAR-PO 3 H 2 ) (6) has been synthesized from [ 13 C 5 ]adenosine. Incorporation of the mass-label into [ 13 C 5 ribose] AICAR-PO 3 H 2 provides a useful standard to aid in metabolite identification and quantification in monitoring metabolic pathways. A synthetic route to the 13 C-labeled compound has not been previously reported. Our method employs a hybrid enzymatic and chemical synthesis approach that applies an enzymatic conversion from adenosine to inosine followed by a ring-cleavage of the protected inosine. A direct phosphorylation of the resulting 2',3'-isopropylidine acadesine (5) was developed to yield the title compound in 99% purity following ion exchange chromatography. This article is protected by copyright. All rights reserved.

Organic Gas Sensor with an Improved Lifetime for Detecting Breath Ammonia in Hemodialysis Patients.

PubMed

Chuang, Ming-Yen; Chen, Chang-Chiang; Zan, Hsiao-Wen; Meng, Hsin-Fei; Lu, Chia-Jung

2017-12-22

In this work, a TFB (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-s-butylphenyl)diphenylamine)]) sensor with a cylindrical nanopore structure exhibits a high sensitivity to ammonia in ppb-regime. The lifetime and sensitivity of the TFB sensor were studied and compared to those of P3HT (poly(3-hexylthiophene)), NPB (N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine), and TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl) benzenamine]) sensors with the same cylindrical nanopore structures. The TFB sensor outstands the others in sensitivity and lifetime and it shows a sensing response (current variation ratio) of 13% to 100 ppb ammonia after 64 days of storage in air. A repeated sensing periods testing and a long-term measurement have also been demonstrated for the test of robustness. The performance of the TFB sensor is stable in both tests, which reveals that the TFB sensor can be utilized in our targeting clinical trials. In the last part of this work, we study the change of ammonia concentration in the breath of hemodialysis (HD) patients before and after dialysis. An obvious drop of breath ammonia concentration can be observed after dialysis. The reduction of breath ammonia is also correlated with the reduction of blood urea nitrogen (BUN). A correlation coefficient of 0.82 is achieved. The result implies that TFB sensor may be used as a real-time and low cost breath ammonia sensor for the daily tracking of hemodialysis patients.

Reversible intercalation of ammonia molecules into a layered double hydroxide structure without exchanging nitrate counter-ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbajal Arizaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.m; Wypych, Fernando; Castillon Barraza, Felipe

2010-10-15

A zinc/aluminum LDH was precipitated with recycled ammonia from a chemical vapor deposition reaction. The LDH presented a crystalline phase with basal distance of 8.9 A, typical for nitrate-containing LDHs, and another phase with a basal distance of 13.9 A. Thermal treatment at 150 {sup o}C eliminated the phase with the bigger basal distance leaving only the anhydrous nitrate-intercalated LDH structure with 8.9 A. Intense N-H stretching modes in the FTIR spectra suggested that the expansion was due to intercalation of ammonia in the form of [NH{sub 4}(NH{sub 3}){sub n}]{sup +} species. When additional samples were precipitated with pure ammonia,more » the conventional LDH nitrate structure was obtained (8.9 A basal distance) at pH=7, as well as a pure crystalline phase with 13.9 A basal distance at pH=10 due to ammonia intercalation that can be removed by heating at 150 {sup o}C or by stirring in acetone, confirming a unusual sensu stricto intercalation process into a LDH without exchanging nitrate ions. - Graphical abstract: LDH-nitrate precipitated with ammonia expands the interlayer space if ammonia is bubbled up to pH 10. The basal distance decreased when the compound was heated at 150 {sup o}C or stirred in acetone. Nitrate ions are not exchanged.« less

Isotope signatures of N2O emitted from vegetable soil: Ammonia oxidation drives N2O production in NH4+-fertilized soil of North China

NASA Astrophysics Data System (ADS)

Zhang, Wei; Li, Yuzhong; Xu, Chunying; Li, Qiaozhen; Lin, Wei

2016-07-01

Nitrous oxide (N2O) is a potent greenhouse gas. In North China, vegetable fields are amended with high levels of N fertilizer and irrigation water, which causes massive N2O flux. The aim of this study was to determine the contribution of microbial processes to N2O production and characterize isotopic signature effects on N2O source partitioning. We conducted a microcosm study that combined naturally abundant isotopologues and gas inhibitor techniques to analyze N2O flux and its isotopomer signatures [δ15Nbulk, δ18O, and SP (intramolecular 15N site preference)] that emitted from vegetable soil after the addition of NH4+ fertilizers. The results show that ammonia oxidation is the predominant process under high water content (70% water-filled pore space), and nitrifier denitrification contribution increases with increasing N content. δ15Nbulk and δ18O of N2O may not provide information about microbial processes due to great shifts in precursor signatures and atom exchange, especially for soil treated with NH4+ fertilizer. SP and associated two end-member mixing model are useful to distinguish N2O source and contribution. Further work is needed to explore isotopomer signature stability to improve N2O microbial process identification.

Ammonia oxidation, denitrification and dissimilatory nitrate reduction to ammonium in two US Great Basin hot springs with abundant ammonia-oxidizing archaea.

PubMed

Dodsworth, Jeremy A; Hungate, Bruce A; Hedlund, Brian P

2011-08-01

Many thermophiles catalyse free energy-yielding redox reactions involving nitrogenous compounds; however, little is known about these processes in natural thermal environments. Rates of ammonia oxidation, denitrification and dissimilatory nitrate reduction to ammonium (DNRA) were measured in source water and sediments of two ≈ 80°C springs in the US Great Basin. Ammonia oxidation and denitrification occurred mainly in sediments. Ammonia oxidation rates measured using (15)N-NO(3)(-) pool dilution ranged from 5.5 ± 0.8 to 8.6 ± 0.9 nmol N g(-1) h(-1) and were unaffected or only mildly stimulated by amendment with NH(4) Cl. Denitrification rates measured using acetylene block ranged from 15.8 ± 0.7 to 51 ± 12 nmol N g(-1) h(-1) and were stimulated by amendment with NO(3)(-) and complex organic compounds. The DNRA rate in one spring sediment measured using an (15)N-NO(3)(-) tracer was 315 ± 48 nmol N g(-1) h(-1). Both springs harboured distinct planktonic and sediment microbial communities. Close relatives of the autotrophic, ammonia-oxidizing archaeon 'Candidatus Nitrosocaldus yellowstonii' represented the most abundant OTU in both spring sediments by 16S rRNA gene pyrotag analysis. Quantitative PCR (qPCR) indicated that 'Ca. N. yellowstonii'amoA and 16S rRNA genes were present at 3.5-3.9 × 10(8) and 6.4-9.0 × 10(8) copies g(-1) sediment. Potential denitrifiers included members of the Aquificales and Thermales. Thermus spp. comprised <1% of 16S rRNA gene pyrotags in both sediments and qPCR for T. thermophilus narG revealed sediment populations of 1.3-1.7 × 10(6) copies g(-1) sediment. These data indicate a highly active nitrogen cycle (N-cycle) in these springs and suggest that ammonia oxidation may be a major source of energy fuelling primary production. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

PRN 93-3: Labeling Statement Prohibiting Application to Water

EPA Pesticide Factsheets

This notice explaining the policy on label statement prohibiting pesticide application to water pertains only to the labeling statement on pesticide products. It does not address the term wetlands as defined with respect to the Clean Water Act.

In vivo stationary flux analysis by 13C labeling experiments.

PubMed

Wiechert, W; de Graaf, A A

1996-01-01

Stationary flux analysis is an invaluable tool for metabolic engineering. In the last years the metabolite balancing technique has become well established in the bioengineering community. On the other hand metabolic tracer experiments using 13C isotopes have long been used for intracellular flux determination. Only recently have both techniques been fully combined to form a considerably more powerful flux analysis method. This paper concentrates on modeling and data analysis for the evaluation of such stationary 13C labeling experiments. After reviewing recent experimental developments, the basic equations for modeling carbon labeling in metabolic systems, i.e. metabolite, carbon label and isotopomer balances, are introduced and discussed in some detail. Then the basics of flux estimation from measured extracellular fluxes combined with carbon labeling data are presented and, finally, this method is illustrated by using an example from C. glutamicum. The main emphasis is on the investigation of the extra information that can be obtained with tracer experiments compared with the metabolite balancing technique alone. As a principal result it is shown that the combined flux analysis method can dispense with some rather doubtful assumptions on energy balancing and that the forward and backward flux rates of bidirectional reaction steps can be simultaneously determined in certain situations. Finally, it is demonstrated that the variant of fractional isotopomer measurement is even more powerful than fractional labeling measurement but requires much higher numerical effort to solve the balance equations.

Effects of season and nitrogen supply on the partitioning of recently fixed carbon in understory vegetation using a 13CO2 pulse labeling technique

NASA Astrophysics Data System (ADS)

Hasselquist, Niles; Metcalfe, Daniel; Högberg, Peter

2013-04-01

Vegetation research in boreal forests has traditionally been focused on trees, with little attention given to understory vegetation. However, understory vegetation has been identified as a key driver for the functioning of boreal forests and may play an important role in the amount of carbon (C) that is entering and leaving these forested ecosystems. We conducted a large-scale 13C pulse labeling experiment to better understand how recently fixed C is allocated in the understory vegetation characteristic of boreal forests. We used transparent plastic chambers to pulse label the understory vegetation with enriched 13CO2 in the early (June) and late (August) growing seasons. This study was also replicated across a nitrogen (N) fertilization treatment to better understand the effects of N availability on C allocation patterns. We present data on the amount of 13C label found in different components of the understory vegetation (i.e. leaves, stems, lichens, mosses, rhizomes and fine roots) as well as CO2 efflux. Additionally, we provide estimates of C residence time (MRT) among the different components and examine how MRT of C is affected by seasonality and N availability. Seasonality had a large effect on how recently fixed C is allocated in understory vegetation, whereas N fertilization influenced the MRT of C in the different components of ericaceous vegetation. Moreover, there was a general trend that N additions increased the amount of 13C in CO2 efflux compared to the amount of 13C in biomass, suggesting that N fertilization may lead to an increase in the utilization of recently fixed C, whereas N-limitation promotes the storage of recently fixed C.

Factors affecting the photoproduction of ammonia from dinitrogen and water by the cyanobacterium Anabaena sp. strain ATCC 33047.

PubMed

Ramos, J L; Guerrero, M G; Losada, M

1987-04-01

Synthesis of ammonia from dinitrogen and water by suspensions of Anabaena sp. Strain ATCC 33047 treated with the glutamine synthetase inhibitor L-methionine-D,L-sulfoximine is strictly dependent on light. Under otherwise optimal conditions, the yield of ammonia production is influenced by irradiance, as well as by the density, depth, and turbulence of the cell suspension. The interaction among these factors seems to determine the actual amount of light available to each single cell or filament in the suspension for the photoproduction process. Under convenient illumination, the limiting factor in the synthesis of ammonia seems to be the cellular nitrogenase activity level, but under limiting light conditions the limiting factor could, however, be the assimilatory power required for nitrogen fixation. Photosynthetic ammonia production from atmospheric nitrogen and water can operate with an efficiency of ca. 10% of its theoretical maximum, representing a remarkable process for the conversion of light energy into chemical energy.

Validation of doubly labeled water method using a ruminant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fancy, S.G.; Blanchard, J.M.; Holleman, D.F.

1986-07-01

CO/sub 2/ production (CDP, ml CO/sub 2/ . g-1 . h-1) by captive caribou and reindeer (Rangifer tarandus) was measured using the doubly labeled water method (/sup 3/H/sub 2/O and H2(18)O) and compared with CO/sub 2/ expiration rates (VCO/sub 2/), adjusted for CO/sub 2/ losses in CH4 and urine, as determined by open-circuit respirometry. CDP calculated from samples of blood or urine from a reindeer in winter was 1-3% higher than the adjusted VCO/sub 2/. Differences between values derived by the two methods of 5-20% were found in summer trials with caribou. None of these differences were statistically significant (Pmore » greater than 0.05). Differences in summer could in part be explained by the net deposition of /sup 3/H, 18O, and unlabeled CO/sub 2/ in antlers and other growing tissues. Total body water volumes calculated from /sup 3/H/sub 2/O dilution were up to 15% higher than those calculated from H/sub 2/(18)O dilution. The doubly labeled water method appears to be a reasonably accurate method for measuring CDP by caribou and reindeer in winter when growth rates are low, but the method may overestimate CDP by rapidly growing and/or fattening animals.« less

The Chemistry of Liquid Ammonia.

ERIC Educational Resources Information Center

Lagowski, J. J.

1978-01-01

The solvent and chemical properties of liquid ammonia are presented. In a certain sense, ammonia is a more versatile solvent than is water because of its ability to solubilize, without reaction, highly negative or reducing species. (Author/BB)

Pore water phosphate and ammonia below the permanent halocline in the south-eastern Baltic Sea and their benthic fluxes under anoxic conditions

NASA Astrophysics Data System (ADS)

Graca, Bożena; Witek, Zbigniew; Burska, Dorota; Białkowska, Izabela; Łukawska-Matuszewska, Katarzyna; Bolałek, Jerzy

2006-12-01

In this paper the results of a study on the distribution of pore water phosphates and ammonia, and their fluxes under anoxic condition in a deep (> 70 m) accumulation-type bottom of the south-eastern Baltic Sea, namely in the Gdańsk Deep and the adjacent areas, are presented. All measurements were taken during the growth period, i.e. in September 2000, April 2001 and June 2002. Benthic phosphate and ammonia fluxes were estimated using Fick's First Law. Phosphate and ammonia concentrations ranged from 7.5 to 266.3 μmol dm - 3 and from 53.6 to 1248.3 μmol dm - 3 , respectively. The values recorded in the central part of the Gdańsk Deep were lower than those found both on its slopes and on the SW slope of the Gotland Deep. The lowest phosphate contents were typical of the Oblique Sill which separates the Gdańsk and Gotland Deeps. In 1993-2002, as a result of anoxia the sediments in the Gdańsk Deep released about 5.1 × 10 3 t P and 22.8 × 10 3 t N. These loads supplied on average 1.5% and 0.9% of phytoplankton's demand for P and N, respectively. In comparison to the total external load of nutrients discharged to the Gulf of Gdańsk (i.e. 8.79 × 10 3 t year - 1 P tot and 130.79 × 10 3 t year - 1 N tot; [Witek, Z., Humborg, Ch., Savchuk, O., Grelowski, A. and Łysiak-Pastuszak, E., 2003. Nitrogen and phosphorus budgets of the Gulf of Gdańsk (Baltic Sea). Est. Coast. Shelf Sci., 57:239-248.]), the return flux of P and N from the anoxic sediments to the water column in the Gdańsk Deep was a minor source of these elements.

A Method to Constrain Genome-Scale Models with 13C Labeling Data

PubMed Central

García Martín, Héctor; Kumar, Vinay Satish; Weaver, Daniel; Ghosh, Amit; Chubukov, Victor; Mukhopadhyay, Aindrila; Arkin, Adam; Keasling, Jay D.

2015-01-01

Current limitations in quantitatively predicting biological behavior hinder our efforts to engineer biological systems to produce biofuels and other desired chemicals. Here, we present a new method for calculating metabolic fluxes, key targets in metabolic engineering, that incorporates data from 13C labeling experiments and genome-scale models. The data from 13C labeling experiments provide strong flux constraints that eliminate the need to assume an evolutionary optimization principle such as the growth rate optimization assumption used in Flux Balance Analysis (FBA). This effective constraining is achieved by making the simple but biologically relevant assumption that flux flows from core to peripheral metabolism and does not flow back. The new method is significantly more robust than FBA with respect to errors in genome-scale model reconstruction. Furthermore, it can provide a comprehensive picture of metabolite balancing and predictions for unmeasured extracellular fluxes as constrained by 13C labeling data. A comparison shows that the results of this new method are similar to those found through 13C Metabolic Flux Analysis (13C MFA) for central carbon metabolism but, additionally, it provides flux estimates for peripheral metabolism. The extra validation gained by matching 48 relative labeling measurements is used to identify where and why several existing COnstraint Based Reconstruction and Analysis (COBRA) flux prediction algorithms fail. We demonstrate how to use this knowledge to refine these methods and improve their predictive capabilities. This method provides a reliable base upon which to improve the design of biological systems. PMID:26379153

Compact sieve-tray distillation column for ammonia-water absorption heat pump: Part 1 -- Design methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anand, G.; Erickson, D.C.

1999-07-01

The distillation column is a key component of ammonia-water absorption units including advanced generator-absorber heat exchange (GAX) cycle heat pumps. The design of the distillation column is critical to unit performance, size, and cost. The distillation column can be designed with random packing, structured packing, or various tray configurations. A sieve-tray distillation column is the least complicated tray design and is less costly than high-efficiency packing. Substantial literature is available on sieve tray design and performance. However, most of the correlations and design recommendations were developed for large industrial hydrocarbon systems and are generally not directly applicable to the compactmore » ammonia-water column discussed here. The correlations were reviewed and modified as appropriate for this application, and a sieve-tray design model was developed. This paper presents the sieve-tray design methodology for highly compact ammonia-water columns. A conceptual design of the distillation column for an 8 ton vapor exchange (VX) GAX heat pump is presented, illustrating relevant design parameters and trends. The design process revealed several issues that have to be investigated experimentally to design the final optimized rectifier. Validation of flooding and weeping limits and tray/point efficiencies are of primary importance.« less

Synthesis of isotopically labeled R- or S-[.sup.13C, .sup.2H] glycerols

DOEpatents

Martinez, Rodolfo A [Santa Fe, NM; Unkefer, Clifford J [Los Alamos, NM; Alvarez, Marc A [Santa Fe, NM

2008-01-22

The present invention is directed to asymmetric chiral labeled glycerols including at least one chiral atom, from one to two .sup.13C atoms and from zero to four deuterium atoms bonded directly to a carbon atom, e.g., (2S) [1,2-.sup.13C.sub.2]glycerol and (2R) [1,2-.sup.13C.sub.2]glycerol, and to the use of such chiral glycerols in the preparation of labeled amino acids.

BIOLOGICAL FILTRATION FOR THE NITRIFICATION OF EXCESSIVE LEVELS OF FREE AMMONIA

EPA Science Inventory

Ammonia in source waters can cause water treatment and distribution system problems. Research on the presence of ammonia in drinking water distribution systems for example has suggested some correlation between excess ammonia and increased biological activity (Servais, 1995; Wilc...

Gas chromatography and isotope ratio mass spectrometry of Pinot Noir wine volatile compounds (δ13C) and solid residues (δ13C, δ15N) for the reassessment of vineyard water-status.

PubMed

Spangenberg, Jorge E; Vogiatzaki, Maria; Zufferey, Vivian

2017-09-29

This paper describes a novel approach to reassess the water status in vineyards based on compound-specific isotope analysis (CSIA) of wine volatile organic compounds (δ 13 C VOC/VPDB ) and bulk carbon and nitrogen isotopes, and the C/N molar ratios of the wine solid residues (δ 13 C SR/VPDB , δ 15 N SR/Air-N2 ). These analyses link gas chromatography/combustion and elemental analysis to isotope ratio mass spectrometry (GC/C/IRMS, EA/IRMS). Field-grown cultivars of Pinot Noir grapevines were exposed during six growing seasons (2009-2014) to controlled soil water availability, while maintaining identical the other environmental variables and agricultural techniques. Wines were produced from the grapes by the same oenological protocol. This permitted for the assessment of the effects in the biochemistry of wines solely induced by the changes in the plant-soil water status. This mimicked the more recurrent and prolonged periods of soil water deficiency due to climate changes. Water stress in grapevine was assessed by the measurement of the predawn leaf water potential (Ψ pd ) and the stable carbon isotope composition of the berry sugars during harvest (must sugars). For quantitation purposes and the normalization of the measured stable carbon isotope ratios of the VOCs, the wine samples were spiked with three standard compounds with known concentration and δ 13 C VPDB values. VOCs were extracted by liquid-liquid extraction and analyzed by gas chromatography/flame ionization detection (GC/FID), gas chromatography/mass spectrometry (GC/MS), and GC/C/IRMS. δ 13 C values were obtained for eighteen VOCs. The solid residues were obtained by freeze-drying wine aliquots and were analyzed for their C and N content and isotope composition by EA/IRMS. All the isotopic ratios (δ 13 C SR , δ 15 N SR , δ 13 C VOC ) are highly correlated with the Ψ pd values, indicating that the proposed gas chromatography and isotope ratio mass spectrometry approach is a useful tool to

Metabolic flux analysis using 13C peptide label measurements

USDA-ARS?s Scientific Manuscript database

13C metabolic flux analysis (MFA) has become the experimental method of choice to investigate cellular metabolism. MFA has established flux maps of central metabolism for dozens of microbes, cell cultures, and plant seeds. Steady-state MFA utilizes isotopic labeling measurements of amino acids obtai...

Effect of Ammonia on Glyoxal SOA in Inorganic Aqueous Seed Particles

NASA Astrophysics Data System (ADS)

Waxman, E.; Volkamer, R. M.; Laskin, A.; Laskin, J.; Koenig, T. K.; Baltensperger, U.; Dommen, J.; Prevot, A. S.; Slowik, J.; Maxut, A.; Noziere, B.; Wang, S.; Yu, J.

2014-12-01

Glyoxal (C2H2O2) is a ubiquitous small molecule that is observed in the terrestrial biogenic, urban, marine and arctic atmosphere. It forms secondary organic aerosol (SOA) as a result of multiphase chemical reactions in water. The rate of these reactions is controlled by the effective Henry's law partitioning coefficient (Heff) which is enhanced in the presence of inorganic salts by up to 3 orders of magnitude (Kampf et al., 2013, ES&T). Aerosol particles are among the most concentrated salt solutions on Earth and the SOA formation rate in aerosol water is strongly modified by this 'salting-in' mechanism. We have studied the effect of gas-phase ammonia on the rate of SOA formation in real particles composed of different inorganic salts (sulfate, nitrate, chloride). A series of simulation chamber experiments were conducted at the Paul Scherrer Institut in Switzerland during Summer 2013. The SOA formation rate in experiments with added gas-phase ammonia (NH3) was found to be greatly accelerated compared to experiments without added NH3. Product analysis of particles included online HR-ToF-AMS and offline nano-DESI and LC-MS. We find that imidazole-like oligomer compounds dominate the observed products, rather than high-O/C oligomers containing solely C, H, and O. We further employed isotopically labelled di-substituted 13C glyoxal experiments in order to unambiguously link product formation to glyoxal (and separate it from chamber wall contamination). We present a molecular perspective on the reaction pathways and evaluate the effect of environmental parameters (RH, particle pH, seed chemical composition) on the formation of these imidazole-like oligomer compounds. The implications for SOA formation from photosensitized oxidation chemistry is discussed.

Defective transport of the obesity mutant PC1/3 N222D contributes to loss of function.

PubMed

Prabhu, Yogikala; Blanco, Elias H; Liu, Ming; Peinado, Juan R; Wheeler, Matthew C; Gekakis, Nicholas; Arvan, Peter; Lindberg, Iris

2014-07-01

Mutations in the PCSK1 gene encoding prohormone convertase 1/3 (PC1/3) are strongly associated with obesity in humans. The PC1/3(N222D) mutant mouse thus far represents the only mouse model that mimics the PC1/3 obesity phenotype in humans. The present investigation addresses the cell biology of the N222D mutation. Metabolic labeling experiments reveal a clear defect in the kinetics of insulin biosynthesis in islets from PC1/3(N222D) mutant mice, resulting in an increase in both proinsulin and its processing intermediates, predominantly lacking cleavage at the Arg-Arg site. Although the mutant PC1/3 zymogen is correctly processed to the 87-kDa form, pulse-chase immunoprecipitation experiments, labeling, and immunohistochemical experiments using uncleavable variants all demonstrate that the PC1/3-N222D protein is largely mislocalized compared with similar wild-type (WT) constructs, being predominantly retained in the endoplasmic reticulum. The PC1/3-N222D mutant also undergoes more efficient degradation via the ubiquitin-proteasome system than the WT enzyme. Lastly, the mutant PC1/3-N222D protein coimmunoprecipitates with WT PC1/3 and exerts a modest effect on intracellular retention of the WT enzyme. These profound alterations in the cell biology of PC1/3-N222D are likely to contribute to the defective insulin biosynthetic events observed in the mutant mice and may be relevant to the dramatic contributions of polymorphisms in this gene to human obesity.

Defective Transport of the Obesity Mutant PC1/3 N222D Contributes to Loss of Function

PubMed Central

Prabhu, Yogikala; Blanco, Elias H.; Liu, Ming; Peinado, Juan R.; Wheeler, Matthew C.; Gekakis, Nicholas; Arvan, Peter

2014-01-01

Mutations in the PCSK1 gene encoding prohormone convertase 1/3 (PC1/3) are strongly associated with obesity in humans. The PC1/3N222D mutant mouse thus far represents the only mouse model that mimics the PC1/3 obesity phenotype in humans. The present investigation addresses the cell biology of the N222D mutation. Metabolic labeling experiments reveal a clear defect in the kinetics of insulin biosynthesis in islets from PC1/3N222D mutant mice, resulting in an increase in both proinsulin and its processing intermediates, predominantly lacking cleavage at the Arg-Arg site. Although the mutant PC1/3 zymogen is correctly processed to the 87-kDa form, pulse-chase immunoprecipitation experiments, labeling, and immunohistochemical experiments using uncleavable variants all demonstrate that the PC1/3-N222D protein is largely mislocalized compared with similar wild-type (WT) constructs, being predominantly retained in the endoplasmic reticulum. The PC1/3-N222D mutant also undergoes more efficient degradation via the ubiquitin-proteasome system than the WT enzyme. Lastly, the mutant PC1/3-N222D protein coimmunoprecipitates with WT PC1/3 and exerts a modest effect on intracellular retention of the WT enzyme. These profound alterations in the cell biology of PC1/3-N222D are likely to contribute to the defective insulin biosynthetic events observed in the mutant mice and may be relevant to the dramatic contributions of polymorphisms in this gene to human obesity. PMID:24828610

In situ, one step removal of ammonia from onshore and offshore formation water of petroleum production fields.

PubMed

Awad Abouelata, Ahmed M; Elhadad, Adel M A; Hammad, Samir

2018-04-21

Fish, crustaceans and other living organisms are threatened due to disposal of harmful contaminants in sea water. Ammonia is considered one of harmful contaminants due to industrial activities of oil companies, where excess ammonia in the formation water is discharged into sea water. Electrochemical treatment (EC) was used in one step for total removal of ammonia and remediation of other contaminants. Three working electrodes were examined EC cell, aluminum, iron and modified electrode (Ti/IrO 2 ). Graphite electrode was used as counter electrode in all processes of binary system. Both ionized and unionized ammonia of onshore (5.54 mg L -1 ) and off shore (110 mg L -1 ) were totally undetected after one step using all types of electrodes. The study was extended also to check the removal efficiency of other contaminants, where the analysis indicated the alleviation of them. Total suspended solid (TSS) of both onshore 64 mg L -1 and offshore 228 mg L -1 samples was reduced to 4 mg L -1 . Total dissolved solids (TDS), chemical oxygen demand (COD) and biological oxygen demand (BOD) of high values, 232,000, 8500 and 2442 mg L -1 were also reduced to lower levels 18,400, 4000 and 1600 mg L -1 , respectively. The formed sludge after EC treatment was also investigated using XRD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chronic toxicity of copper and ammonia to juvenile freshwater mussels (Unionidae)

USGS Publications Warehouse

Wang, N.; Ingersoll, C.G.; Greer, I.E.; Hardesty, D.K.; Ivey, C.D.; Kunz, J.L.; Brumbaugh, W.G.; Dwyer, F.J.; Roberts, A.D.; Augspurger, T.; Kane, C.M.; Neves, R.J.; Barnhart, M.C.

2007-01-01

The objectives of the present study were to develop methods for conducting chronic toxicity tests with juvenile mussels under flow-through conditions and to determine the chronic toxicity of copper and ammonia to juvenile mussels using these methods. In two feeding tests, two-month-old fatmucket (Lampsilis siliquoidea) and rainbow mussel (Villosa iris) were fed various live algae or nonviable algal mixture for 28 d. The algal mixture was the best food resulting in high survival (???90%) and growth. Multiple copper and ammonia toxicity tests were conducted for 28 d starting with two-month-old mussels. Six toxicity tests using the algal mixture were successfully completed with a control survival of 88 to 100%. Among copper tests with rainbow mussel, fatmucket, and oyster mussel (Epioblasma capsaeformis), chronic value ([ChV], geometric mean of the no-observed-effect concentration and the lowest-observed-effect concentration) ranged from 8.5 to 9.8 ??g Cu/L for survival and from 4.6 to 8.5 ??g Cu/L for growth. Among ammonia tests with rainbow mussel, fatmucket, and wavy-rayed lampmussel (L. fasciola), the ChV ranged from 0.37 to 1.2 mg total ammonia N/L for survival and from 0.37 to 0.67 mg N/L for growth. These ChVs were below the U.S. Environmental Protection Agency 1996 chronic water quality criterion (WQC) for copper (15 ??g/L; hardness 170 mg/L) and 1999 WQC for total ammonia (1.26 mg N/L; pH 8.2 and 20??C). Results indicate that toxicity tests with two-month-old mussels can be conducted for 28 d with >80% control survival; growth was frequently a more sensitive endpoint compared to survival; and the 1996 chronic WQC for copper and the 1999 chronic WQC for total ammonia might not be adequately protective of the mussel species tested. However, a recently revised 2007 chronic WQC for copper based on the biotic ligand model may be more protective in the water tested. ?? 2007 SETAC.

Twoplex 12/13 C6 aniline stable isotope and linkage-specific sialic acid labeling 2D-LC-MS workflow for quantitative N-glycomics.

PubMed

Albrecht, Simone; Mittermayr, Stefan; Smith, Josh; Martín, Silvia Millán; Doherty, Margaret; Bones, Jonathan

2017-01-01

Quantitative glycomics represents an actively expanding research field ranging from the discovery of disease-associated glycan alterations to the quantitative characterization of N-glycans on therapeutic proteins. Commonly used analytical platforms for comparative relative quantitation of complex glycan samples include MALDI-TOF-MS or chromatographic glycan profiling with subsequent data alignment and statistical evaluation. Limitations of such approaches include run-to-run technical variation and the potential introduction of subjectivity during data processing. Here, we introduce an offline 2D LC-MS E workflow for the fractionation and relative quantitation of twoplex isotopically labeled N-linked oligosaccharides using neutral 12 C 6 and 13 C 6 aniline (Δmass = 6 Da). Additional linkage-specific derivatization of sialic acids using 4-(4,6-dimethoxy-1,3,5-trizain-2-yl)-4-methylmorpholinium chloride offered simultaneous and advanced in-depth structural characterization. The potential of the method was demonstrated for the differential analysis of structurally defined N-glycans released from serum proteins of patients diagnosed with various stages of colorectal cancer. The described twoplex 12 C 6 / 13 C 6 aniline 2D LC-MS platform is ideally suited for differential glycomic analysis of structurally complex N-glycan pools due to combination and analysis of samples in a single LC-MS injection and the associated minimization in technical variation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Titan's Ammonia Feature

NASA Technical Reports Server (NTRS)

Smythe, W.; Nelson, R.; Boryta, M.; Choukroun, M.

2011-01-01

NH3 has long been considered an important component in the formation and evolution of the outer planet satellites. NH3 is particularly important for Titan, since it may serve as the reservoir for atmospheric nitrogen. A brightening seen on Titan starting in 2004 may arise from a transient low-lying fog or surface coating of ammonia. The spectral shape suggests the ammonia is anhydrous, a molecule that hydrates quickly in the presence of water.

The Far Infrared Vibration-Rotation Spectrum of the Ammonia Dimer.

NASA Astrophysics Data System (ADS)

Loeser, Jennifer Gertrud

1995-11-01

The ammonia dimer has been shown to exhibit unusual weak bonding properties relative to those of the other prototypical second row systems, the hydrogen fluoride dimer and the water dimer. The ultimate goal of the work initiated in this dissertation is to determine a complete intermolecular potential energy surface for the ammonia dimer. It is first necessary to observe its far infrared vibration-rotation-tunneling (VRT) spectrum and to develop a group theoretical model that explains this spectrum in terms of the internal dynamics of the ammonia dimer. These first steps are the subject of this dissertation. First, the current understanding of the ammonia dimer system is reviewed. Group theoretical descriptions of the nature of the ammonia dimer VRT states are explained in detail. An overview of the experimental and theoretical studies of the ammonia dimer made during the last decade is presented. Second, progress on the analysis of the microwave and far infrared spectrum of (ND_3)_2 below 13 cm^{-1} is reported. These spectra directly measure the 'donor -acceptor' interchange splittings in (ND_3) _2, and determine some of the monomer umbrella inversion tunneling splittings. Third, new 80-90 cm^{-1} far infrared spectra of (NH_3)_2 are presented and a preliminary analysis is proposed. Most of the new excited VRT states have been assigned as tunneling sublevels of an out-of-plane intermolecular vibration.

The metabolic role of isoleucine in detoxification of ammonia in cultured mouse neurons and astrocytes.

PubMed

Johansen, Maja L; Bak, Lasse K; Schousboe, Arne; Iversen, Peter; Sørensen, Michael; Keiding, Susanne; Vilstrup, Hendrik; Gjedde, Albert; Ott, Peter; Waagepetersen, Helle S

2007-06-01

Cerebral hyperammonemia is a hallmark of hepatic encephalopathy, a debilitating condition arising secondary to liver disease. Pyruvate oxidation including tricarboxylic acid (TCA) cycle metabolism has been suggested to be inhibited by hyperammonemia at the pyruvate and alpha-ketoglutarate dehydrogenase steps. Catabolism of the branched-chain amino acid isoleucine provides both acetyl-CoA and succinyl-CoA, thus by-passing both the pyruvate dehydrogenase and the alpha-ketoglutarate dehydrogenase steps. Potentially, this will enable the TCA cycle to work in the face of ammonium-induced inhibition. In addition, this will provide the alpha-ketoglutarate carbon skeleton for glutamate and glutamine synthesis by glutamate dehydrogenase and glutamine synthetase (astrocytes only), respectively, both reactions fixing ammonium. Cultured cerebellar neurons (primarily glutamatergic) or astrocytes were incubated in the presence of either [U-13C]glucose (2.5 mM) and isoleucine (1 mM) or [U-13C]isoleucine and glucose. Cell cultures were treated with an acute ammonium chloride load of 2 (astrocytes) or 5 mM (neurons and astrocytes) and incorporation of 13C-label into glutamate, aspartate, glutamine and alanine was determined employing mass spectrometry. Labeling from [U-13C]glucose in glutamate and aspartate increased as a result of ammonium-treatment in both neurons and astrocytes, suggesting that the TCA cycle was not inhibited. Labeling in alanine increased in neurons but not in astrocytes, indicating elevated glycolysis in neurons. For both neurons and astrocytes, labeling from [U-13C]isoleucine entered glutamate and aspartate albeit to a lower extent than from [U-13C]glucose. Labeling in glutamate and aspartate from [U-13C]isoleucine was decreased by ammonium treatment in neurons but not in astrocytes, the former probably reflecting increased metabolism of unlabeled glucose. In astrocytes, ammonia treatment resulted in glutamine production and release to the medium, partially

Simulation of an ammonia-water heat pump water heater with combustion products-driven evaporator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez-Blanco, Horacio; Gluesenkamp, K.; Ally, Moonis Raza

Here, the objective of this work is to simulate a single effct (SE) ammonia-water heat pump for domestic water heating, with innovative aspects for cycle simulation and eventual implementation. Seasonal temperature variations demand verfication of distillation column viability. For the given application and temperature ranges, it is found that some variables need to be controlled if the same column is to be used all year round. In addition, a number of simplifications are considered in this work: an advanced evaporator requireing minimal gas flow and surface area, subcooling at two crucial spots of the cycle and the viability of somemore » pump designs to assuage cavitation issues.« less

Simulation of an ammonia-water heat pump water heater with combustion products-driven evaporator

DOE PAGES

Perez-Blanco, Horacio; Gluesenkamp, K.; Ally, Moonis Raza

2016-12-19

Here, the objective of this work is to simulate a single effct (SE) ammonia-water heat pump for domestic water heating, with innovative aspects for cycle simulation and eventual implementation. Seasonal temperature variations demand verfication of distillation column viability. For the given application and temperature ranges, it is found that some variables need to be controlled if the same column is to be used all year round. In addition, a number of simplifications are considered in this work: an advanced evaporator requireing minimal gas flow and surface area, subcooling at two crucial spots of the cycle and the viability of somemore » pump designs to assuage cavitation issues.« less

Differential contributions of archaeal ammonia oxidizer ecotypes to nitrification in coastal surface waters

PubMed Central

Smith, Jason M; Casciotti, Karen L; Chavez, Francisco P; Francis, Christopher A

2014-01-01

The occurrence of nitrification in the oceanic water column has implications extending from local effects on the structure and activity of phytoplankton communities to broader impacts on the speciation of nitrogenous nutrients and production of nitrous oxide. The ammonia-oxidizing archaea, responsible for carrying out the majority of nitrification in the sea, are present in the marine water column as two taxonomically distinct groups. Water column group A (WCA) organisms are detected at all depths, whereas Water column group B (WCB) are present primarily below the photic zone. An open question in marine biogeochemistry is whether the taxonomic definition of WCA and WCB organisms and their observed distributions correspond to distinct ecological and biogeochemical niches. We used the natural gradients in physicochemical and biological properties that upwelling establishes in surface waters to study their roles in nitrification, and how their activity—ascertained from quantification of ecotype-specific ammonia monooxygenase (amoA) genes and transcripts—varies in response to environmental fluctuations. Our results indicate a role for both ecotypes in nitrification in Monterey Bay surface waters. However, their respective contributions vary, due to their different sensitivities to surface water conditions. WCA organisms exhibited a remarkably consistent level of activity and their contribution to nitrification appears to be related to community size. WCB activity was less consistent and primarily constrained to colder, high nutrient and low chlorophyll waters. Overall, the results of our characterization yielded a strong, potentially predictive, relationship between archaeal amoA gene abundance and the rate of nitrification. PMID:24553472

[Ammonia volatilization loss of nitrogen fertilizer from rice field and wet deposition of atmospheric nitrogen in rice growing season].

PubMed

Su, Chengguo; Yin, Bin; Zhu, Zhaoliang; Shen, Qirong

2003-11-01

Plot and field experiments showed that the NH3 volatilization loss from rice field reached its maximum in 1-3 days after N-fertilization, which was affected by the local climate conditions (e.g., sun illumination, temperature, humidity, wind speed, and rainfall), fertilization time, and ammonium concentration in surface water of the rice field. The wet deposition of atmospheric nitrogen was correlated with the application rate of N fertilizer and the rainfall. The amount of nitrogen brought into soil or surface water by the wet deposition in rice growing season reached 7.5 kg.hm-2. The percent of NH4(+)-N in the wet deposition was about 39.8%-73.2%, with an average of 55.5%. There was a significant correlation of total ammonia volatilization loss with the average concentration of NH4(+)-N in wet deposition and total amount of wet deposition in rice growing season.

The alkaline tide and ammonia excretion after voluntary feeding in freshwater rainbow trout.

PubMed

Bucking, Carol; Wood, Chris M

2008-08-01

We investigated the potential acid-base and nitrogenous waste excretion challenges created by voluntary feeding in freshwater rainbow trout, with particular focus on the possible occurrence of an alkaline tide (a metabolic alkalosis created by gastric HCl secretion during digestion). Plasma metabolites (glucose, urea and ammonia) were measured at various time points before and after voluntary feeding to satiation (approximately 5% body mass meal of dry commercial pellets), as was the net flux of ammonia and titratable alkalinity to the water from unfed and fed fish. Arterial blood, sampled by indwelling catheter, was examined for post-prandial effects on pH, plasma bicarbonate and plasma CO2 tension. There was no significant change in plasma glucose or urea concentrations following feeding, whereas plasma ammonia transiently increased, peaking at threefold above resting values at 12 h after the meal and remaining elevated for 24 h. The increased plasma ammonia was correlated with an increase in net ammonia excretion to the water, with fed fish significantly elevating their net ammonia excretion two- to threefold between 12 and 48 h post feeding. These parameters did not change in unfed control fish. Fed fish likewise increased the net titratable base flux to the water by approximately threefold, which resulted in a transition from a small net acid flux seen in unfed fish to a large net base flux in fed fish. Over 48 h, this resulted in a net excretion of 13 867 micromol kg(-1) more base to the external water than in unfed fish. The arterial blood exhibited a corresponding rise in pH (between 6 and 12 h) and plasma bicarbonate (between 3 and 12 h) following feeding; however, no respiratory compensation was observed, as PaCO2 remained constant. Overall, there was evidence of numerous challenges created by feeding in a freshwater teleost fish, including the occurrence of an alkaline tide, and its compensation by excretion of base to the external water. The possible

Ammonia in comet P/Halley

NASA Technical Reports Server (NTRS)

Meier, R.; Eberhardt, P.; Krankowsky, D.; Hodges, R. R.

1994-01-01

In comet P/Halley the abundances of ammonia relative to water reported in the literature differ by about one order of magnitude from roughly 0.1% up to 2%. Different observational techniques seem to have inherent systematic errors. Using the ion mass channels m/q = 19 amu/e, 18 amu/e and 17 amu/e of the Neutral Mass Spectrometer experiment aboard the spacecraft Giotto, we derive a production rate of ammonia of (1.5(sub -0.7)(sup +0.5))% relative to water. Inside the contact surface we can explain our data by a nuclear source only. The uncertainty in our abundance of ammonia is primarily a result of uncertainties in some key reaction coefficients. We discuss in detail these reactions and the range of error indicated results from extreme assumptions in the rate coefficients. From our data, even in the worst case, we can exclude the ammonia abundance to be only of the order of a few per mill.

Survey of Water and Ammonia in Nearby Galaxies (SWAN): Resolved Ammonia Thermometry and Water and Methanol Masers in IC 342, NGC 6946, and NGC 2146

NASA Astrophysics Data System (ADS)

Gorski, Mark; Ott, Jürgen; Rand, Richard; Meier, David S.; Momjian, Emmanuel; Schinnerer, Eva

2018-04-01

The Survey of Water and Ammonia in Nearby galaxies (SWAN) studies atomic and molecular species across the nuclei of four star-forming galaxies: NGC 253, IC 342, NGC 6946, and NGC 2146. As part of this survey, we present Karl G. Jansky Very Large Array molecular line observations of three galaxies: IC 342, NGC 6946, and NGC 2146. NGC 253 is covered in a previous paper. These galaxies were chosen to span an order of magnitude in star formation rates and to select a variety of galaxy types. We target the metastable transitions of ammonia NH3(1, 1) to (5, 5), the 22 GHz water (H2O) (616–523) transition, and the 36.1 GHz methanol (CH3OH) (4‑1–30) transition. We use the NH3 metastable lines to perform thermometry of the dense molecular gas. We show evidence for uniform heating across the central kiloparsec of IC 342 with two temperature components for the molecular gas, similar to NGC 253, of 27 and 308 K, and that the dense molecular gas in NGC 2146 has a temperature <86 K. We identify two new water masers in IC 342, and one new water maser in each of NGC 6946 and NGC 2146. The two galaxies NGC 253 and NGC 2146, with the most vigorous star formation, host H2O kilomasers. Lastly, we detect the first 36 GHz CH3OH masers in IC 342 and NGC 6946. For the four external galaxies the total CH3OH luminosity in each galaxy suggests a correlation with galactic star formation rate, whereas the morphology of the emission is similar to that of HNCO, a weak shock tracer.

Preparation of High-Quality FeV55N Using Ammonia as a Reductant and Nitrogen Source

NASA Astrophysics Data System (ADS)

Wu, Yue-Dong; Zhang, Guo-Hua; Chou, Kuo-Chih

2018-05-01

High-quality FeV55N has been prepared by using ammonia as a reductant and nitrogen source. The raw materials comprised ammonium vanadate and Fe2O3, which were first reduced and nitrided by ammonia to prepare FeV55N composite powders of VN and Fe2N. Subsequently, the composite powders were sintered at high temperature to obtain a bulk FeV55N alloy. The final products obtained by this method do not contain elemental Al, Si, or C impurities. Furthermore, the residual oxygen content of the final products can be reduced to 0.56 wt.%. After sintering, it is possible to obtain a FeV55N alloy with a density of up to 5.4 g/cm3.

WaterSense Labeled Homes Quick Reference Guide

EPA Pesticide Factsheets

Green building has grown from a niche market to a savvy business strategy. WaterSense labeled homes capitalize on consumer demand by offering homeowners a whole-house solution to help them save water, energy, and money.

Effect of free ammonia concentration on monochloramine penetration within a nitrifying biofilm and its effect on activity, viability, and recovery.

PubMed

Pressman, Jonathan G; Lee, Woo Hyoung; Bishop, Paul L; Wahman, David G

2012-03-01

Chloramine has replaced free chorine for secondary disinfection at many water utilities because of disinfection by-product (DBP) regulations. Because chloramination provides a source of ammonia, there is a potential for nitrification when using chloramines. Nitrification in drinking water distribution systems is undesirable and may result in degradation of water quality and subsequent non-compliance with existing regulations. Thus, nitrification control is a major issue and likely to become increasingly important as chloramine use increases. In this study, monochloramine penetration and its effect on nitrifying biofilm activity, viability, and recovery was investigated and evaluated using microelectrodes and confocal laser scanning microscopy (CLSM). Monochloramine was applied to nitrifying biofilm for 24 h at two different chlorine to nitrogen (Cl(2):N) mass ratios (4:1 [4.4 mg Cl(2)/L] or 1:1 Cl(2):N [5.3 mg Cl(2)/L]), resulting in either a low (0.23 mg N/L) or high (4.2 mg N/L) free ammonia concentration. Subsequently, these biofilm samples were allowed to recover without monochloramine and receiving 4.2 mg N/L free ammonia. Under both monochloramine application conditions, monochloramine fully penetrated into the nitrifying biofilm within 24 h. Despite this complete monochloramine penetration, complete viability loss did not occur, and both biofilm samples subsequently recovered aerobic activity when fed only free ammonia. When monochloramine was applied with a low free ammonia concentration, dissolved oxygen (DO) fully penetrated, but with a high free ammonia concentration, complete cessation of aerobic activity (i.e., oxygen utilization) did not occur and subsequent analysis indicated that oxygen consumption still remained near the substratum. During the ammonia only recovery phase, different spatial recoveries were seen in each of the samples, based on oxygen utilization. It appears that the presence of higher free ammonia concentration allowed a

A Pervaporation Study of Ammonia Solutions Using Molecular Sieve Silica Membranes

PubMed Central

Yang, Xing; Fraser, Thomas; Myat, Darli; Smart, Simon; Zhang, Jianhua; Diniz da Costa, João C.; Liubinas, Audra; Duke, Mikel

2014-01-01

An innovative concept is proposed to recover ammonia from industrial wastewater using a molecular sieve silica membrane in pervaporation (PV), benchmarked against vacuum membrane distillation (VMD). Cobalt and iron doped molecular sieve silica-based ceramic membranes were evaluated based on the ammonia concentration factor downstream and long-term performance. A modified low-temperature membrane evaluation system was utilized, featuring the ability to capture and measure ammonia in the permeate. It was found that the silica membrane with confirmed molecular sieving features had higher water selectivity over ammonia. This was due to a size selectivity mechanism that favoured water, but blocked ammonia. However, a cobalt doped silica membrane previously treated with high temperature water solutions demonstrated extraordinary preference towards ammonia by achieving up to a 50,000 mg/L ammonia concentration (a reusable concentration level) measured in the permeate when fed with 800 mg/L of ammonia solution. This exceeded the concentration factor expected by the benchmark VMD process by four-fold, suspected to be due to the competitive adsorption of ammonia over water into the silica structure with pores now large enough to accommodate ammonia. However, this membrane showed a gradual decline in selectivity, suspected to be due to the degradation of the silica material/pore structure after several hours of operation. PMID:24957120

Tolerance to Ammonia of Thulinius ruffoi (Bertolani, 1981), a Tardigrade Isolated from a Sewage Treatment Plant.

PubMed

Sobczyk, Mateusz; Michno, Klaudia; Kosztyła, Paulina; Stec, Daniel; Michalczyk, Łukasz

2015-12-01

The acute toxicity of ammonia on Thulinius ruffoi (Bertolani, 1981), a eutardigrade isolated from a small waste water treatment plant (WWTP) in Poland, was estimated. Our results show that no active individuals survived a 24 h exposure to solutions equal to or higher than 125 mg/L of total ammonia nitrogen (NH3-N + NH4 (+)-N), which, under the conditions in our experiment, was equivalent to 1.17 mg/L of un-ionised ammonia (NH3). The LC50 concentration of total ammonia nitrogen was equal to 52 mg/L (or 0.65 mg/L un-ionised ammonia). Given that the norms for the concentration of ammonia in treated waters leaving WWTPs are usually several times lower than the LC50 for T. ruffoi, this species does not seem to be a good bioindicator candidate for WWTPs. In this paper we also note that various ecotoxicological studies use different methodological approaches and we suggest that a more uniform methodology may aid interspecific comparisons of LC50 values.

Identification of degradation routes of metamitron in soil microcosms using 13C-isotope labeling.

PubMed

Wang, Shizong; Miltner, Anja; Nowak, Karolina M

2017-01-01

Metamitron is one of the most commonly used herbicide in sugar beet and flower bulb cultures. Numerous laboratory and field studies on sorption and degradation of metamitron were performed. Detailed biodegradation studies in soil using 13 C-isotope labeling are still missing. Therefore, we aimed at providing a detailed turnover mass balance of 13 C 6 -metamitron in soil microcosms over 80 days. In the biotic system, metamitron mineralized rapidly, and 13 CO 2 finally constituted 60% of the initial 13 C 6 -metamitron equivalents. In abiotic control experiments CO 2 rose to only 7.4% of the initial 13 C 6 -metamitron equivalents. The 13 C label from 13 C 6 -metamitron was incorporated into microbial amino acids that were ultimately stabilized in the soil organic matter forming presumably harmless biogenic residues. Finally, 13 C label from 13 C 6 -metamitron was distributed between the 13 CO 2 and the 13 C-biogenic residues indicating nearly complete biodegradation. The parallel increase of 13 C-alanine, 13 C-glutamate and 13 CO 2 indicates that metamitron was initially biodegraded via the desamino-metamitron route suggesting its relevance in the growth metabolism. In later phases of biodegradation, the "Rhodococcus route" was indicated by the low 13 CO 2 evolution and the high relevance of the pyruvate pathway, which aims at biomolecule synthesis and seems to be related to starvation. This is a first report on the detailed degradation route of metamitron in soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transcriptional Response of the Archaeal Ammonia Oxidizer Nitrosopumilus maritimus to Low and Environmentally Relevant Ammonia Concentrations

PubMed Central

Stahl, David A.

2013-01-01

The ability of chemoautotrophic ammonia-oxidizing archaea to compete for ammonia among marine microorganisms at low ambient concentrations has been in part attributed to their extremely high affinity for ammonia, but as yet there is no mechanistic understanding of supporting metabolism. We examined transcription of selected genes for anabolic functions (CO2 fixation, ammonia transport, and cell wall synthesis) and a central catabolic function (ammonia oxidation) in the thaumarchaeon Nitrosopumilus maritimus SCM1 growing at two ammonia concentrations, as measured by combined ammonia and ammonium, one well above the Km for ammonia oxidation (∼500 μM) and the other well below the Km (<10 nM). Transcript levels were generally immediately and differentially repressed when cells transitioned from ammonia-replete to ammonia-limiting conditions. Transcript levels for ammonia oxidation, CO2 fixation, and one of the ammonia transport genes were approximately the same at high and low ammonia availability. Transcripts for all analyzed genes decreased with time in the complete absence of ammonia, but with various rates of decay. The new steady-state mRNA levels established are presumably more reflective of the natural physiological state of ammonia-oxidizing archaea and offer a reference for interpreting message abundance patterns in the natural environment. PMID:23995944

Ammonia oxidation coupled to CO2 fixation by archaea and bacteria in an agricultural soil.

PubMed

Pratscher, Jennifer; Dumont, Marc G; Conrad, Ralf

2011-03-08

Ammonia oxidation is an essential part of the global nitrogen cycling and was long thought to be driven only by bacteria. Recent findings expanded this pathway also to the archaea. However, most questions concerning the metabolism of ammonia-oxidizing archaea, such as ammonia oxidation and potential CO(2) fixation, remain open, especially for terrestrial environments. Here, we investigated the activity of ammonia-oxidizing archaea and bacteria in an agricultural soil by comparison of RNA- and DNA-stable isotope probing (SIP). RNA-SIP demonstrated a highly dynamic and diverse community involved in CO(2) fixation and carbon assimilation coupled to ammonia oxidation. DNA-SIP showed growth of the ammonia-oxidizing bacteria but not of archaea. Furthermore, the analysis of labeled RNA found transcripts of the archaeal acetyl-CoA/propionyl-CoA carboxylase (accA/pccB) to be expressed and labeled. These findings strongly suggest that ammonia-oxidizing archaeal groups in soil autotrophically fix CO(2) using the 3-hydroxypropionate-4-hydroxybutyrate cycle, one of the two pathways recently identified for CO(2) fixation in Crenarchaeota. Catalyzed reporter deposition (CARD)-FISH targeting the gene encoding subunit A of ammonia monooxygenase (amoA) mRNA and 16S rRNA of archaea also revealed ammonia-oxidizing archaea to be numerically relevant among the archaea in this soil. Our results demonstrate a diverse and dynamic contribution of ammonia-oxidizing archaea in soil to nitrification and CO(2) assimilation and that their importance to the overall archaeal community might be larger than previously thought.

Ammonia oxidation coupled to CO2 fixation by archaea and bacteria in an agricultural soil

PubMed Central

Pratscher, Jennifer; Dumont, Marc G.; Conrad, Ralf

2011-01-01

Ammonia oxidation is an essential part of the global nitrogen cycling and was long thought to be driven only by bacteria. Recent findings expanded this pathway also to the archaea. However, most questions concerning the metabolism of ammonia-oxidizing archaea, such as ammonia oxidation and potential CO2 fixation, remain open, especially for terrestrial environments. Here, we investigated the activity of ammonia-oxidizing archaea and bacteria in an agricultural soil by comparison of RNA- and DNA-stable isotope probing (SIP). RNA-SIP demonstrated a highly dynamic and diverse community involved in CO2 fixation and carbon assimilation coupled to ammonia oxidation. DNA-SIP showed growth of the ammonia-oxidizing bacteria but not of archaea. Furthermore, the analysis of labeled RNA found transcripts of the archaeal acetyl-CoA/propionyl-CoA carboxylase (accA/pccB) to be expressed and labeled. These findings strongly suggest that ammonia-oxidizing archaeal groups in soil autotrophically fix CO2 using the 3-hydroxypropionate–4-hydroxybutyrate cycle, one of the two pathways recently identified for CO2 fixation in Crenarchaeota. Catalyzed reporter deposition (CARD)-FISH targeting the gene encoding subunit A of ammonia monooxygenase (amoA) mRNA and 16S rRNA of archaea also revealed ammonia-oxidizing archaea to be numerically relevant among the archaea in this soil. Our results demonstrate a diverse and dynamic contribution of ammonia-oxidizing archaea in soil to nitrification and CO2 assimilation and that their importance to the overall archaeal community might be larger than previously thought. PMID:21368116

Ammonia volatilization and atmospheric N deposition following straw and urea application from a rice-wheat rotation in southeastern China

NASA Astrophysics Data System (ADS)

Sun, Liying; Wu, Zhen; Ma, Yuchun; Liu, Yinglie; Xiong, Zhengqin

2018-05-01

Ammonia is a vital component of the nitrogen (N) cycle of terrestrial ecosystems in terms of volatilization and deposition. Here, a field experiment was undertaken to simultaneously investigate the effects of rice straw and urea incorporation on ammonia volatilization, atmospheric N deposition, yields and agronomic nitrogen use efficiency (NUE) under a rice-wheat system in China. The experiment involved four treatments: control (0 N, 0 straw), NS0 (250 kg N ha-1 season-1, 0 straw), NS1 (250 kg N ha-1 season-1, 3 t ha-1 yr-1 straw), and NS2 (250 kg N ha-1 season-1, 6 t ha-1 yr-1 straw) in the rice-wheat annual rotation system. The results indicated that the NS0, NS1 and NS2 treatments emitted cumulative ammonia of 14.0%, 16.4%, and 19.2%, respectively in the rice season and 7.6%, 11.1%, and 12.3%, respectively in the wheat season among the total urea-N application. Compared to the NS0 treatment, the NS1 and NS2 treatments significantly increased the cumulative ammonia emissions by 15.5% (p < 0.05) and 33.5% (p < 0.05), respectively in the rice season and 39.9% (p < 0.05) and 53.1% (p < 0.05), respectively in the wheat season. There was no significant difference between the NS2 and NS1 treatments during the wheat season. The amount of NH4+-N deposition accounted for 56.1% of the total inorganic N deposition during the whole rice-wheat system. The bulk NH4+-N deposition during the period of fertilization contributed 73.9% and 5.7% to the total NH4+-N deposition in the rice and wheat season, respectively. Overall, straw incorporation increased ammonia volatilization, not affecting the crop grain yield or NUE. The seasonal variation in NH4+-N bulk deposition was closely related to N fertilizer application.

Influence of ammonia flow rate for improving properties of polycrystalline GaN

NASA Astrophysics Data System (ADS)

Ariff, A.; Ahmad, M. A.; Hassan, Z.; Zainal, N.

2018-06-01

Post-annealing treatment in ammonia ambient is widely accepted for GaN material, but less works have been done to investigate the influence of the ammonia (NH3) flow rate for reducing the N-deficiency as well as improving the quality of the material. In this work, we investigated the influence of NH3 flow rate at 1, 2, 3, and 4 slm in improving properties of a ∼1 μm thick polycrystalline GaN layer. Our simulation work suggested that the uniformity of temperature and pressure gradient of the NH3 gas did not lead to the reduction of N-deficiency of the polycrystalline GaN layer. Instead, it was found that the mitigation of the N-deficiency was strongly influenced by the fluid velocity of the NH3 gas, which had passed over the layer. Either at lower or higher fluid velocity, the chance for the active N atoms to incorporate into the GaN lattice structure was low. Therefore, the N-deficiency on the polycrystalline GaN layer could not be minimized under these conditions. As measured by EDX, the N atoms incorporation was the most effective when the NH3 flow rate at 3 slm, suggesting the flow rate significantly improved the N-deficiency of the polycrystalline GaN layer. Furthermore, it favored the formation of larger hexagonal faceted grains, with the smallest FWHM of XRD peaks from the GaN diffractions in (10 1 bar 0), (0002) and (10 1 bar 1) orientations, while allowing the polycrystalline GaN layer to show sharp and intense emissions peak of NBE in a PL spectrum.

Application of unsymmetrical indirect covariance NMR methods to the computation of the (13)C <--> (15)N HSQC-IMPEACH and (13)C <--> (15)N HMBC-IMPEACH correlation spectra.

PubMed

Martin, Gary E; Hilton, Bruce D; Irish, Patrick A; Blinov, Kirill A; Williams, Antony J

2007-10-01

Utilization of long-range (1)H--(15)N heteronuclear chemical shift correlation has continually grown in importance since the first applications were reported in 1995. More recently, indirect covariance NMR methods have been introduced followed by the development of unsymmetrical indirect covariance processing methods. The latter technique has been shown to allow the calculation of hyphenated 2D NMR data matrices from more readily acquired nonhyphenated 2D NMR spectra. We recently reported the use of unsymmetrical indirect covariance processing to combine (1)H--(13)C GHSQC and (1)H--(15)N GHMBC long-range spectra to yield a (13)C--(15)N HSQC-HMBC chemical shift correlation spectrum that could not be acquired in a reasonable period of time without resorting to (15)N-labeled molecules. We now report the unsymmetrical indirect covariance processing of (1)H--(13)C GHMBC and (1)H--(15)N IMPEACH spectra to afford a (13)C--(15)N HMBC-IMPEACH spectrum that has the potential to span as many as six to eight bonds. Correlations for carbon resonances long-range coupled to a protonated carbon in the (1)H--(13)C HMBC spectrum are transferred via the long-range (1)H--(15)N coupling pathway in the (1)H--(15)N IMPEACH spectrum to afford a much broader range of correlation possibilities in the (13)C--(15)N HMBC-IMPEACH correlation spectrum. The indole alkaloid vincamine is used as a model compound to illustrate the application of the method. (c) 2007 John Wiley & Sons, Ltd.

Ammonia excretion increased and urea excretion decreased in urine of a new world nectarivorous bat with decreased nitrogen intake.

PubMed

Herrera M, L Gerardo; Ramirez P, Nicte; Miron M, Leticia

2006-01-01

We determined the effect of water and nitrogen intake on nitrogenous waste composition in the nectarivorous Pallas's long-tongued bat Glossophaga soricina (Phyllostomidae) to test the hypothesis that bats reduce excretion of urea nitrogen and increase the excretion of ammonia nitrogen as nitrogen intake decreases and water intake decreases. Because changes in urine nitrogen composition are expected only in animals whose natural diets are low in nitrogen and high in water content, we also measured maintenance nitrogen requirements (MNR). We hypothesized that, similar to other plant-eating vertebrates, nectarivorous bats have low MNR. Our nitrogen excretion hypothesis was partly proved correct. There was an increase in the proportion of N excreted as ammonia and a decrease in the proportion excreted as urea in low-nitrogen diets. The proportion of N excreted as ammonia and urea was independent of water intake. Most individuals were ureotelic (n = 28), and only a few were ureo-ammonotelic (n = 3) or ammonotelic (n = 2). According to our nitrogen requirement hypothesis, apparent MNR (60 mg kg(-0.75) d(-1)) and truly digestible MNR (54 mg N kg(-0.75) d(-1)) were low. A decrease in urea excretion in low-nitrogen diets may result from urea recycling from liver to the gut functioning as a nitrogen salvage system in nectarivorous bats. This mechanism probably contributes to the low MNR found in Pallas's long-tongued bats.

Critical litter moisture maximizes ammonia generation

USDA-ARS?s Scientific Manuscript database

The natural breakdown of litter (bedding material mixed with deposits of feces, feathers, spilled feed and water) generates ammonia in poultry houses. Good management practices can reduce ammonia concentrations in poultry houses. Findings from a recent publication indicate there is a critical litt...

The Full-Scale Implementation of an Innovative Biological Ammonia Treatment Process

EPA Science Inventory

Across the United States, high levels of ammonia in drinking water sources can be found, including small communities like Palo, Iowa (approximate population of 1,026). Although ammonia in water does not pose a direct health concern, ammonia nitrification can cause a number of iss...

Biogenic volatile organic compounds (BVOCs) emission of Scots pine under drought stress - a 13CO2 labeling study to determine de novo and pool emissions under different treatments

NASA Astrophysics Data System (ADS)

Lüpke, M.

2015-12-01

Plants emit biogenic volatile organic compounds (BVOCs) to e.g. communicate and to defend herbivores. Yet BVOCs also impact atmospheric chemistry processes, and lead to e.g. the built up of secondary organic aerosols. Abiotic stresses, such as drought, however highly influence plant physiology and subsequently BVOCs emission rates. In this study, we investigated the effect of drought stress on BVOCs emission rates of Scots pine trees, a de novo and pool emitter, under controlled climate chamber conditions within a dynamic enclosure system consisting of four plant chambers. Isotopic labeling with 13CO2 was used to detect which ratio of emissions of BVOCs derives from actual synthesis and from storage organs under different treatments. Additionally, the synthesis rate of the BVOCs synthesis can be determined. The experiment consisted of two campaigns (July 2015 and August 2015) of two control and two treated trees respectively in four controlled dynamic chambers simultaneously. Each campaign lasted for around 21 days and can be split into five phases: adaptation, control, dry-out, drought- and re-watering phase. The actual drought phase lasted around five days. During the campaigns two samples of BVOCs emissions were sampled per day and night on thermal desorption tubes and analyzed by a gas chromatograph coupled with a mass spectrometer and a flame ionization detector. Additionally, gas exchange of water and CO2, soil moisture, as well as leaf and chamber temperature was monitored continuously. 13CO2 labeling was performed simultaneously in all chambers during the phases control, drought and re-watering for five hours respectively. During the 13CO2 labeling four BVOCs emission samples per chamber were taken to identify the labeling rate on emitted BVOCs. First results show a decrease of BVOCs emissions during the drought phase and a recovery of emission after re-watering, as well as different strength of reduction of single compounds. The degree of labeling with 13

Tempe Waste Water Degradation Using TiO2-N/Bentonite alginate Granule Photocatalyst with Ultraviolet Light Irradiation

NASA Astrophysics Data System (ADS)

Khoirun Nisaa', Aldila; Wardhani, Sri; Purwonugroho, Danar; Darjito

2018-01-01

Tempe waste water stew has high ammonia concentration which causes odor due to polluting by anaerobic decay. Free ammonia in the waste has exceeded the limit, thus endangering the aquatic environment. This research aims to determine the activity of photocatalyst granule TiO2-N/bentonite-alginate as decomposers of compounds in the photodegradation process. Photodegradation is the decomposition process of compounds by semiconductors with light. Results expected includes the photocatalyst activity of TiO2-N/bentonite-alginate granule produced by ultraviolet rays is known based on the effect of dopant N concentration on the catalyst and the effect of photocatalytic ratio toward tempe waste water. Methods proposed in this research are activation of bentonite using H2SO4 0.8 M, TiO2-N synthesize by sonication method with urea as the source of N, then TiO2-N impregnation into bentonite. Photocatalyst in granule form synthesized with alginate was then dripped with syringe pump into 3% (w/v) CaCl2. The photocatalyst characterization will be performed using XRD. The optimum tempe waste water degradation at the concentration of TiO2-N 0.4 (g/g) bentonite is 53.66%. The ratio of photocatalyst and tempe waste water, optimum at 150 mg of photocatalyst with 25 mL of waste equal to 53.66%.

Optimal tracers for parallel labeling experiments and 13C metabolic flux analysis: A new precision and synergy scoring system.

PubMed

Crown, Scott B; Long, Christopher P; Antoniewicz, Maciek R

2016-11-01

13 C-Metabolic flux analysis ( 13 C-MFA) is a widely used approach in metabolic engineering for quantifying intracellular metabolic fluxes. The precision of fluxes determined by 13 C-MFA depends largely on the choice of isotopic tracers and the specific set of labeling measurements. A recent advance in the field is the use of parallel labeling experiments for improved flux precision and accuracy. However, as of today, no systemic methods exist for identifying optimal tracers for parallel labeling experiments. In this contribution, we have addressed this problem by introducing a new scoring system and evaluating thousands of different isotopic tracer schemes. Based on this extensive analysis we have identified optimal tracers for 13 C-MFA. The best single tracers were doubly 13 C-labeled glucose tracers, including [1,6- 13 C]glucose, [5,6- 13 C]glucose and [1,2- 13 C]glucose, which consistently produced the highest flux precision independent of the metabolic flux map (here, 100 random flux maps were evaluated). Moreover, we demonstrate that pure glucose tracers perform better overall than mixtures of glucose tracers. For parallel labeling experiments the optimal isotopic tracers were [1,6- 13 C]glucose and [1,2- 13 C]glucose. Combined analysis of [1,6- 13 C]glucose and [1,2- 13 C]glucose labeling data improved the flux precision score by nearly 20-fold compared to widely use tracer mixture 80% [1- 13 C]glucose +20% [U- 13 C]glucose. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Interactions between ammonia and nitrite oxidizing bacteria in co-cultures: Is there evidence for mutualism, commensalism, or competition?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sayavedra-Soto, Luis; Arp, Daniel

Nitrification is a two-step environmental microbial process in the nitrogen cycle in which ammonia is oxidized to nitrate. Ammonia-oxidizing bacteria and archaea oxidize ammonia to nitrite and nitrite is oxidized to nitrate by nitrite-oxidizing bacteria. These microorganisms, which likely act in concert in a microbial community, play critical roles in the movement of inorganic N in soils, sediments and waters and are essential to the balance of the nitrogen cycle. Anthropogenic activity has altered the balance of the nitrogen cycle through agriculture practices and organic waste byproducts. Through their influence on available N for plant growth, nitrifying microorganisms influence plantmore » productivity for food and fiber production and the associated carbon sequestration. N Fertilizer production, primarily as ammonia, requires large inputs of natural gas and hydrogen. In croplands fertilized with ammonia-based fertilizers, nitrifiers contribute to the mobilization of this N by producing nitrate (NO3-), wasting the energy used in the production and application of ammonia-based fertilizer. The resulting nitrate is readily leached from these soils, oxidized to gaseous N oxides (greenhouse gases), and denitrified to N2 (which is no longer available as a plant N source). Still, ammonia oxidizers are beneficial in the treatment of wastewater and they also show potential to contribute to microbial bioremediation strategies for clean up of environments contaminated with chlorinated hydrocarbons. Mitigation of the negative effects and exploitation of the beneficial effects of nitrifiers will be facilitated by a systems-level understanding of the interactions of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria with the environment and with each other.« less

A physical catalyst for the electrolysis of nitrogen to ammonia

PubMed Central

Johnson, Daniel; Peng, Rui; Hensley, Dale K.; Bonnesen, Peter V.; Yang, Fengchang; Zhang, Fei; Tschaplinski, Timothy J.; Engle, Nancy L.; Wu, Zili; Meyer, Harry M.; Sumpter, Bobby G.

2018-01-01

Ammonia synthesis consumes 3 to 5% of the world’s natural gas, making it a significant contributor to greenhouse gas emissions. Strategies for synthesizing ammonia that are not dependent on the energy-intensive and methane-based Haber-Bosch process are critically important for reducing global energy consumption and minimizing climate change. Motivated by a need to investigate novel nitrogen fixation mechanisms, we herein describe a highly textured physical catalyst, composed of N-doped carbon nanospikes, that electrochemically reduces dissolved N2 gas to ammonia in an aqueous electrolyte under ambient conditions. The Faradaic efficiency (FE) achieves 11.56 ± 0.85% at −1.19 V versus the reversible hydrogen electrode, and the maximum production rate is 97.18 ± 7.13 μg hour−1 cm−2. The catalyst contains no noble or rare metals but rather has a surface composed of sharp spikes, which concentrates the electric field at the tips, thereby promoting the electroreduction of dissolved N2 molecules near the electrode. The choice of electrolyte is also critically important because the reaction rate is dependent on the counterion type, suggesting a role in enhancing the electric field at the sharp spikes and increasing N2 concentration within the Stern layer. The energy efficiency of the reaction is estimated to be 5.25% at the current FE of 11.56%. PMID:29719860

Highly selective transformation of ammonia nitrogen to N2 based on a novel solar-driven photoelectrocatalytic-chlorine radical reactions system.

PubMed

Ji, Youzhi; Bai, Jing; Li, Jinhua; Luo, Tao; Qiao, Li; Zeng, Qingyi; Zhou, Baoxue

2017-11-15

A highly selective method for transforming ammonia nitrogen to N 2 was proposed, based on a novel solar-driven photoelectrocatalytic-chlorine radical reactions (PEC-chlorine) system. The PEC-chlorine system was facilitated by a visible light response WO 3 nanoplate array (NPA) electrode in an ammonia solution containing chloride ions (Cl - ). Under illumination, photoholes from WO 3 promote the oxidation of Cl - to chlorine radical (Cl). This radical can selectively transform ammonia nitrogen to N 2 (79.9%) and NO 3 - (19.2%), similar to the breakpoint chlorination reaction. The ammonia nitrogen removal efficiency increased from 10.6% (PEC without Cl - ) to 99.9% with the PEC-chlorine system within 90 min operation, which can be attributed to the cyclic reactions between Cl - /Cl and the reaction intermediates (NH 2 , NHCl, etc.) that expand the degradation reactions from the surface of the electrodes to the whole solution system. Moreover, Cl is the main radical species contributing to the transformation of ammonia nitrogen to N 2 , which is confirmed by the tBuOH capture experiment. Compared to conventional breakpoint chlorination, the PEC-chlorine system is a more economical and efficient means for ammonia nitrogen degradation because of the fast removal rate, no additional chlorine cost, and its use of clean energy (since it is solar-driven). Copyright © 2017 Elsevier Ltd. All rights reserved.

CACA-TOCSY with alternate 13C–12C labeling: a 13Cα direct detection experiment for mainchain resonance assignment, dihedral angle information, and amino acid type identification

PubMed Central

Takeuchi, Koh; Frueh, Dominique P.; Sun, Zhen-Yu J.; Hiller, Sebastian

2010-01-01

We present a 13C direct detection CACA-TOCSY experiment for samples with alternate 13C–12C labeling. It provides inter-residue correlations between 13Cα resonances of residue i and adjacent Cαs at positions i − 1 and i + 1. Furthermore, longer mixing times yield correlations to Cα nuclei separated by more than one residue. The experiment also provides Cα-to-sidechain correlations, some amino acid type identifications and estimates for ψ dihedral angles. The power of the experiment derives from the alternate 13C–12C labeling with [1,3-13C] glycerol or [2-13C] glycerol, which allows utilizing the small scalar 3JCC couplings that are masked by strong 1JCC couplings in uniformly 13C labeled samples. PMID:20383561

Tracing the atomic nitrogen abundance in star-forming regions with ammonia deuteration

NASA Astrophysics Data System (ADS)

Furuya, Kenji; Persson, Magnus V.

2018-06-01

Partitioning of elemental nitrogen in star-forming regions is not well constrained. Most nitrogen is expected to be partitioned among atomic nitrogen (N I), molecular nitrogen (N_2), and icy N-bearing molecules, such as NH_3 and N_2. N I is not directly observable in the cold gas. In this paper, we propose an indirect way to constrain the amount of N I in the cold gas of star-forming clouds, via deuteration in ammonia ice, the [ND2H/NH2D]/[NH2D/NH3] ratio. Using gas-ice astrochemical simulations, we show that if atomic nitrogen remains as the primary reservoir of nitrogen during cold ice formation stages, the [ND2H/NH2D]/[NH2D/NH3] ratio is close to the statistical value of 1/3 and lower than unity, whereas if atomic nitrogen is largely converted into N-bearing molecules, the ratio should be larger than unity. Observability of ammonia isotopologues in the inner hot regions around low-mass protostars, where ammonia ice has sublimated, is also discussed. We conclude that the [ND2H/NH2D]/[NH2D/NH3] ratio can be quantified using a combination of Very Large Array and Atacama Large Millimeter/submillimeter Array observations with reasonable integration times, at least towards IRAS 16293-2422, where high molecular column densities are expected.

An automated growth enclosure for metabolic labeling of Arabidopsis thaliana with 13C-carbon dioxide - an in vivo labeling system for proteomics and metabolomics research

PubMed Central

2011-01-01

Background Labeling whole Arabidopsis (Arabidopsis thaliana) plants to high enrichment with 13C for proteomics and metabolomics applications would facilitate experimental approaches not possible by conventional methods. Such a system would use the plant's native capacity for carbon fixation to ubiquitously incorporate 13C from 13CO2 gas. Because of the high cost of 13CO2 it is critical that the design conserve the labeled gas. Results A fully enclosed automated plant growth enclosure has been designed and assembled where the system simultaneously monitors humidity, temperature, pressure and 13CO2 concentration with continuous adjustment of humidity, pressure and 13CO2 levels controlled by a computer running LabView software. The enclosure is mounted on a movable cart for mobility among growth environments. Arabidopsis was grown in the enclosure for up to 8 weeks and obtained on average >95 atom% enrichment for small metabolites, such as amino acids and >91 atom% for large metabolites, including proteins and peptides. Conclusion The capability of this labeling system for isotope dilution experiments was demonstrated by evaluation of amino acid turnover using GC-MS as well as protein turnover using LC-MS/MS. Because this 'open source' Arabidopsis 13C-labeling growth environment was built using readily available materials and software, it can be adapted easily to accommodate many different experimental designs. PMID:21310072

Soil Nitrification and N2O Production: the connection with N concentration and Soil Water Content

NASA Astrophysics Data System (ADS)

Zhu-Barker, X.; Horwath, W. R.

2016-12-01

The development of mitigation strategies to reduce nitrous oxide (N2O) emission from soils is dependent on explicating the biophysical factors affecting different N2O production pathways. Ammonia oxidation and heterotrophic denitrification are the main pathways of N2O production, depending on soil conditions such as soil moisture content, oxygen (O2) content and N substrate. Many researchers have reported that N2O production increased as substrate concentration and soil moisture content increased. However, less understood is how N fertilizer concentration and moisture content interact to affect N2O production pathways. To investigate interaction and its effect on O2 consumption, we incubated three agricultural soils (clay, sandy loam, and peat) with different concentrations of (NH4)2SO4 (0-1000 µg N g-1) under 50 %, 75%, and 100% of water holding capacity. All treatments received 15N -KNO3 to bring the concentrations of NO3-_N in soils to 50 mg kg-1 soil and the NO3- pool to an enrichment of 10 atom% 15N. In all soils, the total amount of O2 consumption and N2O production increased as soil ammonical N concentration increased. The increased soil moisture significantly promoted N2O production in sandy loam and clay loam soils, compared to the peat soil. These results indicate that N2O production increased as substrate concentration increased likely due to the onset of O2 limitation caused by ammonia oxidation.

Liquid Water on Enceladus from Observations of Ammonia and Ar-40 in the Plume

NASA Technical Reports Server (NTRS)

Waite, J. H., Jr.; Lewis, W. S.; Magee, B. A.; Lunine, J. I.; McKinnon, W. B.; Glein, C. R.; Mousis, O.; Young, D. T.; Brockwell, T.; Westlake, J.;

Procurement of exogenous ammonia by the swallowtail butterfly, Papilio polytes, for protein biosynthesis and sperm production

NASA Astrophysics Data System (ADS)

Honda, Keiichi; Takase, Hiroyuki; Ômura, Hisashi; Honda, Hiroshi

2012-09-01

How to acquire sufficient quantity of nitrogen is a pivotal issue for herbivores, particularly for lepidopterans (butterflies and moths) of which diet quality greatly differs among their life stages. Male Lepidoptera often feed from mud puddles, dung, and carrion, a behavior known as puddling, which is thought to be supplementary feeding targeted chiefly at sodium. During copulation, males transfer a spermatophore to females that contains, besides sperm, nutrients (nuptial gifts) rich in sodium, proteins, and amino acids. However, it is still poorly understood how adults, mostly nectarivores, extract nitrogen from the environment. We examined the availability of two ubiquitous inorganic nitrogenous ions in nature, viz. ammonium (or ammonia) and nitrate ions, as nutrients in a butterfly, and show that exogenous ammonia ingested by adult males of the swallowtail, Papilio polytes, can serve as a resource for protein biosynthesis. Feeding experiments with 15N-labeled ammonium chloride revealed that nitrogen was incorporated into eupyrene spermatozoa, seminal protein, and thoracic muscle. Ammonia uptake by males significantly increased the number of eupyrene sperms in the reproductive tract tissues. The females also had the capacity to assimilate ammonia into egg protein. Consequently, it is evident that acquired ammonia is utilized for the replenishment of proteins allocable for reproduction and somatic maintenance. The active exploitation of exogenous ammonia as a nutrient by a butterfly would foster better understanding of the foraging and reproductive strategies in insects.

Procurement of exogenous ammonia by the swallowtail butterfly, Papilio polytes, for protein biosynthesis and sperm production.

PubMed

Honda, Keiichi; Takase, Hiroyuki; Ômura, Hisashi; Honda, Hiroshi

2012-09-01

How to acquire sufficient quantity of nitrogen is a pivotal issue for herbivores, particularly for lepidopterans (butterflies and moths) of which diet quality greatly differs among their life stages. Male Lepidoptera often feed from mud puddles, dung, and carrion, a behavior known as puddling, which is thought to be supplementary feeding targeted chiefly at sodium. During copulation, males transfer a spermatophore to females that contains, besides sperm, nutrients (nuptial gifts) rich in sodium, proteins, and amino acids. However, it is still poorly understood how adults, mostly nectarivores, extract nitrogen from the environment. We examined the availability of two ubiquitous inorganic nitrogenous ions in nature, viz. ammonium (or ammonia) and nitrate ions, as nutrients in a butterfly, and show that exogenous ammonia ingested by adult males of the swallowtail, Papilio polytes, can serve as a resource for protein biosynthesis. Feeding experiments with (15)N-labeled ammonium chloride revealed that nitrogen was incorporated into eupyrene spermatozoa, seminal protein, and thoracic muscle. Ammonia uptake by males significantly increased the number of eupyrene sperms in the reproductive tract tissues. The females also had the capacity to assimilate ammonia into egg protein. Consequently, it is evident that acquired ammonia is utilized for the replenishment of proteins allocable for reproduction and somatic maintenance. The active exploitation of exogenous ammonia as a nutrient by a butterfly would foster better understanding of the foraging and reproductive strategies in insects.

Effects of ammonia load on glucose metabolism by isolated ovine duodenal mucosa.

PubMed

Regmi, P R; Dixon, W T; Oba, M

2008-09-01

To determine the effects of ammonia load on glucose metabolism in ruminant small intestinal tissues, duodenal mucosal cells (DMC) were isolated from growing female sheep (n = 10; 46. 0 +/- 0. 8 kg of BW) fed diets differing in CP content: high (19. 4%) vs. low (13. 1%). Ammonia concentration in the duodenal digesta fluid was greater for sheep fed a high CP diet compared with those fed a low CP diet (16. 4 +/- 1. 0 vs. 9. 1 +/- 1. 8 mM). The isolated primary mucosal cells were incubated for 90 min with [2-(13)C] glucose (3 mM) and ammonium chloride (0, 0. 1, 1, 5, 10, 20, or 50 mM) in Krebs-Ringer HEPES buffer. It was hypothesized that DMC would increase glucose carbon utilization for the synthesis of nonessential AA when the ammonia concentration in the incubation media increased. However, utilization of glucose carbon for alanine synthesis decreased linearly (P = 0. 03) as the ammonia concentration in the incubation media increased. Furthermore, glucose disappearance and utilization of glucose carbon for aspartate synthesis were not affected (P > 0. 47) by the ammonia concentration. Contrarily, in vitro glucose disappearance was greater (P = 0. 03) for DMC isolated from sheep fed a low CP diet vs. a high CP diet [14. 6 +/- 1. 6 vs. 8. 6 +/- 1. 3 nmol.(10(6) cells)(-1).(90 min) (-1)], and hexokinase activity was greater (P = 0. 01) in the mucosa of sheep fed a low CP diet compared with a high CP diet (1. 22 +/- 0. 05 vs. 1. 04 +/- 0. 02 mUnit/mg of protein). These observations indicate that ammonia load does not affect the extent of glucose utilization by DMC, and that glucose carbon may not play a significant role for the synthesis of alanine, aspartate, or glutamate when DMC are exposed to increased concentrations of ammonia.

Cultivation of a highly enriched ammonia-oxidizing archaeon of thaumarchaeotal group I.1b from an agricultural soil.

PubMed

Kim, Jong-Geol; Jung, Man-Young; Park, Soo-Je; Rijpstra, W Irene C; Sinninghe Damsté, Jaap S; Madsen, Eugene L; Min, Deullae; Kim, Jin-Seog; Kim, Geun-Joong; Rhee, Sung-Keun

2012-06-01

Nitrification of excess ammonia in soil causes eutrophication of water resources and emission of atmospheric N(2) O gas. The first step of nitrification, ammonia oxidation, is mediated by Archaea as well as Bacteria. The physiological reactions mediated by ammonia-oxidizing archaea (AOA) and their contribution to soil nitrification are still unclear. Results of non-culture-based studies have shown the thaumarchaeotal group I.1b lineage of AOA to be dominant over both AOA of group I.1a and ammonia-oxidizing bacteria in various soils. We obtained from an agricultural soil a highly enriched ammonia-oxidizing culture dominated by a single archaeal population [c. 90% of total cells, as determined microscopically (by fluorescence in situ hybridization) and by quantitative PCR of its 16S rRNA gene]. The archaeon (termed 'strain JG1') fell within thaumarchaeotal group I.1b and was related to the moderately thermophilic archaeon, Candidatus Nitrososphaera gargensis, and the mesophilic archaeon, Ca. Nitrososphaera viennensis with 97.0% and 99.1% 16S rRNA gene sequence similarity respectively. Strain JG1 was neutrophilic (growth range pH 6.0-8.0) and mesophilic (growth range temperature 25-40°C). The optimum temperature of strain JG1 (35-40°C) is > 10°C higher than that of ammonia-oxidizing bacteria (AOB). Membrane analysis showed that strain JG1 contained a glycerol dialkyl glycerol tetraether, GDGT-4, and its regioisomer as major core lipids; this crenarchaeol regioisomer was previously detected in similar abundance in the thermophile, Ca. N. gargensis and has been frequently observed in tropical soils. Substrate uptake assays showed that the affinity of strain JG1 for ammonia and oxygen was much higher than those of AOB. These traits may give a competitive advantage to AOA related to strain JG1 in oligotrophic environments. (13) C-bicarbonate incorporation into archaeal lipids of strain JG1 established its ability to grow autotrophically. Strain JG1 produced a

The Ammonia Smoke Fountain: An Interesting Thermodynamic Adventure.

ERIC Educational Resources Information Center

Alexander, M. Dale

1999-01-01

Describes a new demonstration that uses an apparatus like the ammonia-fountain apparatus but with modifications designed to produce ammonium-chloride smoke. This demonstration is easy to perform, interesting to observe, and allows demonstration of the solubility of ammonia in water, the basic nature of ammonia, the acidic nature of hydrogen…

Engineering Copper Carboxylate Functionalities on Water Stable Metal–Organic Frameworks for Enhancement of Ammonia Removal Capacities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, Jayraj N.; Garcia-Gutierrez, Erika Y.; Moran, Colton M.

Functionalization of copper carboxylate groups on a series of UiO-66 metal organic framework (MOF) analogues and their corresponding impact on humid and dry ammonia adsorption behavior were studied. Relative locations of possible carboxylic acid binding sites for copper on the MOF analogues were varied on ligand and missing linker defect sites. Materials after copper incorporation exhibited increased water vapor and ammonia affinity during isothermal adsorption and breakthrough experiments, respectively. The introduction of copper markedly increased ammonia adsorption capacities for all adsorbents possessing carboxyl binding sites. In particular, the new MOF UiO-66-(COOCu)2 displayed the highest ammonia breakthrough capacities of 6.38 andmore » 6.84 mmol g–1 under dry and humid conditions, respectively, while retaining crystallinity and porosity. Relative carboxylic acid site locations were also found to impact sorbent stability, as missing linker defect functionalized materials degraded under humid conditions after copper incorporation. Postsynthetic metal insertion provides a method for adding sites that are analogous to open metal sites while maintaining good structural stability.« less

Partitioning Residue-derived and Residue-induced Emissions of N2O Using 15N-labelled Crop Residues

NASA Astrophysics Data System (ADS)

Farrell, R. E.; Carverhill, J.; Lemke, R.; Knight, J. D.

2014-12-01

Estimates of N2O emissions in Canada indicate that 17% of all agriculture-based emissions are associated with the decomposition of crop residues. However, research specific to the western Canadian prairies (including Saskatchewan) has shown that the N2O emission factor for N sources in this region typically ranges between 0.2 and 0.6%, which is well below the current IPCC default emission factor of 1.0%. Thus, it stands to reason that emissions from crop residues should also be lower than those calculated using the current IPCC emission factor. Current data indicates that residue decomposition, N mineralization and N2O production are affected by a number of factors such as C:N ratio and chemical composition of the residue, soil type, and soil water content; thus, a bench-scale incubation study was conducted to examine the effects of soil type and water content on N2O emissions associated with the decomposition of different crop residues. The study was carried out using soils from the Black, Dark Brown, Brown, and Gray soil zones and was conducted at both 50% and 70% water-filled pore space (WFPS); the soils were amended with 15N-labeled residues of wheat, pea, canola, and flax, or with an equivalent amount of 15N-labeled urea; 15N2O production was monitored using a Picarro G5101-i isotopic N2O analyzer. Crop residue additions to the soils resulted in both direct and indirect emissions of N2O, with residue derived emissions (RDE; measured as 15N2O) generally exceeding residue-induced emissions (RIE) at 50% WFPS—with RDEs ranging from 42% to 88% (mean = 58%) of the total N2O. Conversely, at 70% WFPS, RDEs were generally lower than RIEs—ranging from 21% to 83% (mean = 48%). Whereas both water content and soil type had an impact on N2O production, there was a clear and consistent trend in the emission factors for the residues; i.e., emissions were always greatest for the canola residue and lowest for the wheat residue and urea fertilizer; and intermediate for pea

Timing and magnitude of C partitioning through a young loblolly pine (Pinus taeda L.) stand using 13C labeling and shade treatments.

PubMed

Warren, J M; Iversen, C M; Garten, C T; Norby, R J; Childs, J; Brice, D; Evans, R M; Gu, L; Thornton, P; Weston, D J

2012-06-01

The dynamics of rapid changes in carbon (C) partitioning within forest ecosystems are not well understood, which limits improvement of mechanistic models of C cycling. Our objective was to inform model processes by describing relationships between C partitioning and accessible environmental or physiological measurements, with a special emphasis on short-term C flux through a forest ecosystem. We exposed eight 7-year-old loblolly pine (Pinus taeda L.) trees to air enriched with (13)CO(2) and then implemented adjacent light shade (LS) and heavy shade (HS) treatments in order to manipulate C uptake and flux. The impacts of shading on photosynthesis, plant water potential, sap flow, basal area growth, root growth and soil CO(2) efflux rate (CER) were assessed for each tree over a 3-week period. The progression of the (13)C label was concurrently tracked from the atmosphere through foliage, phloem, roots and surface soil CO(2) efflux. The HS treatment significantly reduced C uptake, sap flow, stem growth and fine root standing crop, and resulted in greater residual soil water content to 1 m depth. Soil CER was strongly correlated with sap flow on the previous day, but not the current day, with no apparent treatment effect on the relationship. Although there were apparent reductions in new C flux belowground, the HS treatment did not noticeably reduce the magnitude of belowground autotrophic and heterotrophic respiration based on surface soil CER, which was overwhelmingly driven by soil temperature and moisture. The (13)C label was immediately detected in foliage on label day (half-life = 0.5 day), progressed through phloem by Day 2 (half-life = 4.7 days), roots by Days 2-4, and subsequently was evident as respiratory release from soil which peaked between Days 3 and 6. The δ(13)C of soil CO(2) efflux was strongly correlated with phloem δ(13)C on the previous day, or 2 days earlier. While the (13)C label was readily tracked through the ecosystem, the fate of root C

Water masers and ammonia (1, 1) and (2, 2) towards six regions in the Carina Nebula

NASA Astrophysics Data System (ADS)

Breen, S. L.; Green, C.-E.; Cunningham, M. R.; Voronkov, M. A.; Horiuchi, S.; Green, J. A.

2018-01-01

We present water maser and ammonia (1, 1) and (2, 2) observations, towards six regions in the Carina Nebula, conducted with the Australia Telescope Compact Array. In total five water masers were detected within two of the target fields, and we provide their accurate positions and characteristics. These five water masers constitute all of the known masers detected towards star formation regions in the Carina Nebula and we argue, that given the evidence for active star formation, and the presence of many high-mass stars, the Carina Nebula is uncharacteristically devoid of masers. Our results are consistent with the Carina Nebula having a lack of young high-mass stars, despite the presence of older high-mass stars. Ammonia (1, 1) and (2, 2) emission was detected towards all but one of the target fields and we find that their linewidths and derived temperatures are consistent with the presence of young star formation regions.

Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-1-propanol + water)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, M.H.; Lai, M.D.

1995-03-01

Solutions of amines are frequently used in gas-treating processes to remove acid gases, such as CO{sub 2} and H{sub 2}S, from gas streams in the natural gas and synthetic ammonia industries and petroleum chemical plants. The solubility and diffusivity of N{sub 2}O in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water) were measured at 30, 35, and 40 C and at atmospheric pressure. Six (monoethanolamine + N-methyldiethanolamine + water) and five (monoethanolamine + 2-amino-2-methyl-l-propanol + water) systems were studied. The total amine mass percent in all cases was 30. The solubilities were measured by a solubilitymore » apparatus similar to that of Haimour and Sandall (1984). A wetted wall column absorber was used to obtain the diffusivity of N{sub 2}O in amines. The N{sub 2}O solubilities in amine solutions have been correlated on the basis of the excess Henry constant correlation of Wang et al. (1992). The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water).« less

The First in Vivo Observation of 13C- 15N Coupling in Mammalian Brain

NASA Astrophysics Data System (ADS)

Kanamori, Keiko; Ross, Brian D.

2001-12-01

[5-13C,15N]Glutamine, with 1J(13C-15N) of 16 Hz, was observed in vivo in the brain of spontaneously breathing rats by 13C MRS at 4.7 T. The brain [5-13C]glutamine peak consisted of the doublet from [5-13C,15N]glutamine and the center [5-13C,14N]glutamine peak, resulting in an apparent triplet with a separation of 8 Hz. The time course of formation of brain [5-13C,15N]glutamine was monitored in vivo with a time resolution of 20-35 min. This [5-13C,15N]glutamine was formed by glial uptake of released neurotransmitter [5-13C]glutamate and its reaction with 15NH3 catalyzed by the glia-specific glutamine synthetase. The neurotransmitter glutamate C5 was selectively13C-enriched by intravenous [2,5-13C]glucose infusion to 13C-label whole-brain glutamate C5, followed by [12C]glucose infusion to chase 13C from the small and rapidly turning-over glial glutamate pool, leaving 13C mainly in the neurotransmitter [5-13C]glutamate pool, which is sequestered in vesicles until release. Hence, the observed [5-13C,15N]glutamine arises from a coupling between 13C of neuronal origin and 15N of glial origin. Measurement of the rate of brain [5-13C,15N]glutamine formation provides a novel noninvasive method of studying the kinetics of neurotransmitter uptake into glia in vivo, a process that is crucial for protecting the brain from glutamate excitotoxicity.

CACA-TOCSY with alternate 13C-12C labeling: a 13Calpha direct detection experiment for mainchain resonance assignment, dihedral angle information, and amino acid type identification.

PubMed

Takeuchi, Koh; Frueh, Dominique P; Sun, Zhen-Yu J; Hiller, Sebastian; Wagner, Gerhard

2010-05-01

We present a (13)C direct detection CACA-TOCSY experiment for samples with alternate (13)C-(12)C labeling. It provides inter-residue correlations between (13)C(alpha) resonances of residue i and adjacent C(alpha)s at positions i - 1 and i + 1. Furthermore, longer mixing times yield correlations to C(alpha) nuclei separated by more than one residue. The experiment also provides C(alpha)-to-sidechain correlations, some amino acid type identifications and estimates for psi dihedral angles. The power of the experiment derives from the alternate (13)C-(12)C labeling with [1,3-(13)C] glycerol or [2-(13)C] glycerol, which allows utilizing the small scalar (3)J(CC) couplings that are masked by strong (1)J(CC) couplings in uniformly (13)C labeled samples.

Reductive chemical release of N-glycans as 1-amino-alditols and subsequent 9-fluorenylmethyloxycarbonyl labeling for MS and LC/MS analysis.

PubMed

Wang, Chengjian; Qiang, Shan; Jin, Wanjun; Song, Xuezheng; Zhang, Ying; Huang, Linjuan; Wang, Zhongfu

2018-06-06

Glycoproteins play pivotal roles in a series of biological processes and their glycosylation patterns need to be structurally and functionally characterized. However, the lack of versatile methods to release N-glycans as functionalized forms has been undermining glycomics studies. Here a novel method is developed for dissociation of N-linked glycans from glycoproteins for analysis by MS and online LC/MS. This new method employs aqueous ammonia solution containing NaBH 3 CN as the reaction medium to release glycans from glycoproteins as 1-amino-alditol forms. The released glycans are conveniently labeled with 9-fluorenylmethyloxycarbonyl (Fmoc) and analyzed by ESI-MS and online LC/MS. Using the method, the neutral and acidic N-glycans were successfully released without peeling degradation of the core α-1,3-fucosylated structure or detectable de-N-acetylation, revealing its general applicability to various types of N-glycans. The Fmoc-derivatized N-glycans derived from chicken ovalbumin, Fagopyrum esculentum Moench Pollen and FBS were successfully analyzed by online LC/MS to distinguish isomers. The 1-amino-alditols were also permethylated to form quaternary ammonium cations at the reducing end, which enhance the MS sensitivity and are compatible with sequential multi-stage mass spectrometry (MS n ) fragmentation for glycan sequencing. The Fmoc-labeled N-glycans were further permethylated to produce methylated carbamates for determination of branches and linkages by sequential MS n fragmentation. N-Glycosylation represents one of the most common post-translational modification forms and plays pivotal roles in the structural and functional regulation of proteins in various biological activities, relating closely to human health and diseases. As a type of informational molecule, the N-glycans of glycoproteins participate directly in the molecular interactions between glycan epitopes and their corresponding protein receptors. Detailed structural and functional

Ambient ammonia exposures in an agricultural community and pediatric asthma morbidity

PubMed Central

Loftus, Christine; Yost, Michael; Sampson, Paul; Torres, Elizabeth; Arias, Griselda; Vasquez, Victoria Breckwich; Hartin, Kris; Armstrong, Jenna; Tchong-French, Maria; Vedal, Sverre; Bhatti, Parveen; Karr, Catherine

2015-01-01

Background Large-scale animal feeding operations compromise regional air quality in the rural United States through emission of pollutants such as ammonia gas. Exposure to airborne pollution from animal feeding operations may cause pediatric asthma exacerbations in surrounding communities. Objectives To describe spatial and temporal patterns in ambient ammonia concentrations in an agricultural region, and to investigate associations between short-term fluctuations in ammonia and subsequent changes in respiratory health in children with asthma. Methods For 13 months in the Yakima Valley of Washington State, 14 monitors sampled ammonia in outdoor air for 24-hour periods every 6 days. School-age children with asthma (n=51) were followed for two health outcomes: biweekly reports of asthma symptoms and quick relief medication usage, and daily measurements of forced expiratory volume in one second (FEV1). We assessed associations between each outcome and ammonia using generalized estimating equations. Results 24-hour ammonia concentrations varied from 0.2 to 238.1 μg/m3 during the study period and displayed a strong correlation with proximity to animal feeding operations. FEV1% was 3.8% lower (95% CI: 0.2, 7.3) per interquartile increase in one-day lagged ammonia concentration and 3.0% lower (95% CI: 0.5, 5.8) for two-day lagged concentration. We observed no associations between self-reported asthma symptoms or medication usage and estimated ammonia exposure. Conclusions Ammonia concentrations were elevated in this community and strongly predicted by proximity to animal feeding operations. Ammonia's association with acute lung function decrements in children with asthma in the surrounding community may be causal or, alternatively, ammonia may be a marker for other pollutants from animal feeding operations associated with respiratory effects. PMID:26352250

Ammonia volatilization from crop residues and frozen green manure crops

NASA Astrophysics Data System (ADS)

de Ruijter, F. J.; Huijsmans, J. F. M.; Rutgers, B.

2010-09-01

Agricultural systems can lose substantial amounts of nitrogen (N). To protect the environment, the European Union (EU) has adopted several directives that set goals to limit N losses. National Emission Ceilings (NEC) are prescribed in the NEC directive for nitrogen oxides and ammonia. Crop residues may contribute to ammonia volatilization, but sufficient information on their contribution to the national ammonia volatilization is lacking. Experiments were carried out with the aim to assess the ammonia volatilization of crop residues left on the soil surface or incorporated into the soil under the conditions met in practice in the Netherlands during late autumn and winter. Ammonia emission from residues of broccoli, leek, sugar beet, cut grass, fodder radish (fresh and frozen) and yellow mustard (frozen) was studied during two winter seasons using volatilization chambers. Residues were either placed on top of soil or mixed with soil. Mixing residues with soil gave insignificant ammonia volatilization, whereas volatilization was 5-16 percent of the N content of residues when placed on top of soil. Ammonia volatilization started after at least 4 days. Total ammonia volatilization was related to C/N-ratio and N concentration of the plant material. After 37 days, cumulative ammonia volatilization was negligible from plant material with N concentration below 2 percent, and was 10 percent of the N content of plant material with 4 percent N. These observations can be explained by decomposition of plant material by micro-organisms. After an initial built up of the microbial population, NH 4+ that is not needed for their own growth is released and can easily emit as NH 3 at the soil surface. The results of the experiments were used to estimate the contribution of crop residues to ammonia volatilization in the Netherlands. Crop residues of arable crops and residues of pasture topping may contribute more than 3 million kg NH 3-N to the national ammonia volatilization of the

Submersible microbial desalination cell for simultaneous ammonia recovery and electricity production from anaerobic reactors containing high levels of ammonia.

PubMed

Zhang, Yifeng; Angelidaki, Irini

2015-02-01

High ammonia concentration in anaerobic reactors can seriously inhibit the anaerobic digestion process. In this study, a submersible microbial desalination cell (SMDC) was developed as an innovative method to lower the ammonia level in a continuous stirred tank reactor (CSTR) by in situ ammonia recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L during 30 days, resulting in an average recovery rate of 80 g-N/m(2)/d. Meanwhile, a maximum power density of 0.71±0.5 W/m(2) was generated at 2.85 A/m(2). Both current driven NH4(+) migration and free NH3 diffusion were identified as the mechanisms responsible for the ammonia transportation. With an increase in initial ammonia concentration and a decrease in external resistance, the SMDC performance was enhanced. In addition, the coexistence of other cations in CSTR or cathode had no negative effect on the ammonia transportation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of ammonia exposure on coagulation in white shrimp, Litopenaeus vannamei.

PubMed

Chang, Zhong-Wen; Chiang, Pei-Chi; Cheng, Winton; Chang, Chin-Chyuan

2015-08-01

Ammonia (un-ionized plus ionized ammonia as nitrogen), the end product of protein catabolism, is produced by decomposing organic matter. In aquaculture, shrimp are commonly exposed to high concentrations of ammonia that induces immunological and histological changes. The purpose of this study was to evaluate the effects on hemolymph coagulation time, transglutaminase (TG) activity as well as TG and clottable protein (CP) genes expressions in Litopenaeus vannamei when exposed to ambient ammonia-nitrogen (N) at 0, 1, 5, and 10mg/L for 0, 2, and 7 days. The actual concentrations in control and tests solution were 0.001, 1.15, 5.11, and 11.68mg/L for ammonia-N, and 7×10(-5), 0.080, 0.357, and 0.815mg/L for NH3-N (unionized ammonia). Delayed coagulation time following exposure to 5 and 10mg/L of ambient ammonia-N for 7 days, and increased transglutaminase (TG) activity following exposure to 5 and 1mg/L of ambient ammonia-N for 2 and 7 days, respectively, were observed. Downregulated TG expression and upregulated clottable protein (CP) expression in the hemocytes of L. vannamei exposed to 10 and 5mg/L of ambient ammonia-N for 2 and 7 days, respectively, were shown. These results indicated that ambient ammonia-N (>5mg/L) and NH3-N (>0.357mg/L) interrupted coagulation and down-regulated TG gene expression in L. vannamei, which caused ecotoxicity on immune deficiencies and may contribute the increased susceptibility to infection by pathogens. Copyright © 2015 Elsevier Inc. All rights reserved.

Characterization of La/Fe/TiO2 and Its Photocatalytic Performance in Ammonia Nitrogen Wastewater

PubMed Central

Luo, Xianping; Chen, Chunfei; Yang, Jing; Wang, Junyu; Yan, Qun; Shi, Huquan; Wang, Chunying

2015-01-01

La/Fe/TiO2 composite photocatalysts were synthesized by Sol-Gel method and well characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen-physical adsorption, and UV-Vis diffuse reflectance spectra (UV-Vis DRS). It is interesting that the doped catalysts were in anatase phase while the pure TiO2 was in rutile phase. In addition, the composites possessed better physical chemical properties in photocatalytic activity than pure TiO2: stronger visible-light-response ability, larger specific surface area, and more regular shape in morphology. The photodegradation results of ammonia nitrogen indicate that: the La/Fe/TiO2 had higher catalytic activity to ammonia nitrogen waste water compared pure TiO2 and the other single metal-doped TiO2. pH 10 and 2 mmol/L H2O2 were all beneficial to the removal of ammonia nitrogen by La/Fe/TiO2. However, the common inorganic ions of Cl−, NO3−, SO42−, HCO3−/CO32−, Na+, K+, Ca2+ and Mg2+ in water all inhibited the degradation of ammonia nitrogen. By balance calculation, at least 20% of ammonia nitrogen was converted to N2 during the 64.6% removal efficiency of ammonia nitrogen. PMID:26593929

Ammonia volatilization losses from paddy fields under controlled irrigation with different drainage treatments.

PubMed

He, Yupu; Yang, Shihong; Xu, Junzeng; Wang, Yijiang; Peng, Shizhang

2014-01-01

The effect of controlled drainage (CD) on ammonia volatilization (AV) losses from paddy fields under controlled irrigation (CI) was investigated by managing water table control levels using a lysimeter. Three drainage treatments were implemented, namely, controlled water table depth 1 (CWT1), controlled water table depth 2 (CWT2), and controlled water table depth 3 (CWT3). As the water table control levels increased, irrigation water volumes in the CI paddy fields decreased. AV losses from paddy fields reduced due to the increases in water table control levels. Seasonal AV losses from CWT1, CWT2, and CWT3 were 59.8, 56.7, and 53.0 kg N ha(-1), respectively. AV losses from CWT3 were 13.1% and 8.4% lower than those from CWT1 and CWT2, respectively. A significant difference in the seasonal AV losses was confirmed between CWT1 and CWT3. Less weekly AV losses followed by TF and PF were also observed as the water table control levels increased. The application of CD by increasing water table control levels to a suitable level could effectively reduce irrigation water volumes and AV losses from CI paddy fields. The combination of CI and CD may be a feasible water management method of reducing AV losses from paddy fields.

Ammonia emissions from land application of manures

USDA-ARS?s Scientific Manuscript database

Ammonia volatilization can be a major nitrogen (N) loss process for surface-applied manures. There is concern that current manure management practices are contributing to ammonia losses in the Mid-Atlantic region with subsequent reductions in air quality and increases in N losses to streams and est...

Preparation of [13C3]-melamine and [13C3]-cyanuric acid and their application to the analysis of melamine and cyanuric acid in meat and pet food using liquid chromatography-tandem mass spectrometry.

PubMed

Varelis, P; Jeskelis, R

2008-10-01

For the determination of melamine and cyanuric acid the labelled internal standards [(13)C(3)]-melamine and [(13)C(3)]-cyanuric acid were synthesized using the common substrate [(13)C(3)]-cyanuric chloride by reaction with ammonia and acidified water, respectively. Standards with excellent isotopic and chemical purities were obtained in acceptable yields. These compounds were used to develop an isotope dilution liquid chromatography/mass spectrometry (LC/MS) method to determine melamine and cyanuric acid in catfish, pork, chicken, and pet food. The method involved extraction into aqueous methanol, liquid-liquid extraction and ion exchange solid phase clean-up, with normal phase high-performance liquid chromatography (HPLC) in the so-called hydrophilic interaction mode. The method had a limit of detection (LOD) of 10 microg kg(-1) for both melamine and cyanuric acid in the four foods with a percentage coefficient of variation (CV) of less than 10%. The recovery of the method at this level was in the range of 87-110% and 96-110% for melamine and cyanuric acid, respectively.

Ammonia binding to the oxygen-evolving complex of photosystem II identifies the solvent-exchangeable oxygen bridge (μ-oxo) of the manganese tetramer

PubMed Central

Pérez Navarro, Montserrat; Ames, William M.; Nilsson, Håkan; Lohmiller, Thomas; Pantazis, Dimitrios A.; Rapatskiy, Leonid; Nowaczyk, Marc M.; Neese, Frank; Boussac, Alain; Messinger, Johannes; Lubitz, Wolfgang; Cox, Nicholas

2013-01-01

The assignment of the two substrate water sites of the tetra-manganese penta-oxygen calcium (Mn4O5Ca) cluster of photosystem II is essential for the elucidation of the mechanism of biological O-O bond formation and the subsequent design of bio-inspired water-splitting catalysts. We recently demonstrated using pulsed EPR spectroscopy that one of the five oxygen bridges (μ-oxo) exchanges unusually rapidly with bulk water and is thus a likely candidate for one of the substrates. Ammonia, a water analog, was previously shown to bind to the Mn4O5Ca cluster, potentially displacing a water/substrate ligand [Britt RD, et al. (1989) J Am Chem Soc 111(10):3522–3532]. Here we show by a combination of EPR and time-resolved membrane inlet mass spectrometry that the binding of ammonia perturbs the exchangeable μ-oxo bridge without drastically altering the binding/exchange kinetics of the two substrates. In combination with broken-symmetry density functional theory, our results show that (i) the exchangable μ-oxo bridge is O5 {using the labeling of the current crystal structure [Umena Y, et al. (2011) Nature 473(7345):55–60]}; (ii) ammonia displaces a water ligand to the outer manganese (MnA4-W1); and (iii) as W1 is trans to O5, ammonia binding elongates the MnA4-O5 bond, leading to the perturbation of the μ-oxo bridge resonance and to a small change in the water exchange rates. These experimental results support O-O bond formation between O5 and possibly an oxyl radical as proposed by Siegbahn and exclude W1 as the second substrate water. PMID:24023065

Chemical looping of metal nitride catalysts: low-pressure ammonia synthesis for energy storage† †Electronic supplementary information (ESI) available: Experimental and computational details, free energy plots for the NH3 evolution and N2 reduction with Co3N/Co, Fe4N/Fe, Mn5N2/Mn4N, Mo2N/Mo, CrN/Cr2N, TaN/Ta2N, NbN/Nb2N, Li3N/LiH, Ba3N2/BaH2, Sr3N2/SrH2, and Ca3N2/CaH2, surface oxidation energetics, ΔGvac[NH*x, yH*] based on gas phase H2 as hydrogen source, NH3 evolution with Fe-doped Mn4N, NH3 evolution with Mn6N2.58, Ca3N2 and Sr2N after correcting for partial nitride hydrolysis, NH3 yield from Ca3N2vs. time and H2 gas flow rate. See DOI: 10.1039/c5sc00789e

PubMed Central

Avram, A. M.; Peterson, B. A.; Pfromm, P. H.; Peterson, A. A.

2015-01-01

The activity of many heterogeneous catalysts is limited by strong correlations between activation energies and adsorption energies of reaction intermediates. Although the reaction is thermodynamically favourable at ambient temperature and pressure, the catalytic synthesis of ammonia (NH3), a fertilizer and chemical fuel, from N2 and H2 requires some of the most extreme conditions of the chemical industry. We demonstrate how ammonia can be produced at ambient pressure from air, water, and concentrated sunlight as renewable source of process heat via nitrogen reduction with a looped metal nitride, followed by separate hydrogenation of the lattice nitrogen into ammonia. Separating ammonia synthesis into two reaction steps introduces an additional degree of freedom when designing catalysts with desirable activation and adsorption energies. We discuss the hydrogenation of alkali and alkaline earth metal nitrides and the reduction of transition metal nitrides to outline a promoting role of lattice hydrogen in ammonia evolution. This is rationalized via electronic structure calculations with the activity of nitrogen vacancies controlling the redox-intercalation of hydrogen and the formation and hydrogenation of adsorbed nitrogen species. The predicted trends are confirmed experimentally with evolution of 56.3, 80.7, and 128 μmol NH3 per mol metal per min at 1 bar and above 550 °C via reduction of Mn6N2.58 to Mn4N and hydrogenation of Ca3N2 and Sr2N to Ca2NH and SrH2, respectively. PMID:29218166

The recovery of 13C-labeled oleic acid in rat lymph after administration of long chain triacylglycerols or specific structured triacylglycerols.

PubMed

Vistisen, Bodil; Mu, Huiling; Høy, Carl-Erik

2006-09-01

Consumption of specific structured triacylglycerols, MLM (M = medium chain fatty acid, L = long chain fatty acid), delivers fast energy and long chain fatty acids to the organism. The purpose of the present study was to compare lymphatic absorption of (13)C-labeled MLM and (13)C-labeled LLL in rats. Stable isotope labeling enables the separation of the endogenous and exogenous fatty acids. Lymph was collected during 24 h following administration of MLM or LLL. Lymph fatty acid composition and (13)C-enrichment were determined and quantified by gas chromatography combustion isotope ratio mass spectrometry. The recovery of 18:1n-9 was higher after administration of LLL compared with MLM (58.1% +/- 7.4% and 29.1% +/- 3.9%, respectively, P < 0.001). This may be due to a higher chylomicron formation stimulated by a higher amount of long chain fatty acids in the intestine after LLL compared with MLM administration. This was confirmed by the tendencies of higher lymphatic transport of endogenous fatty acids. The study revealed a higher lymphatic recovery of the administered long chain fatty acids after LLL compared with MLM consumption.

Stabilization of ammonia-rich hydrate inside icy planets.

PubMed

Naden Robinson, Victor; Wang, Yanchao; Ma, Yanming; Hermann, Andreas

2017-08-22

The interior structure of the giant ice planets Uranus and Neptune, but also of newly discovered exoplanets, is loosely constrained, because limited observational data can be satisfied with various interior models. Although it is known that their mantles comprise large amounts of water, ammonia, and methane ices, it is unclear how these organize themselves within the planets-as homogeneous mixtures, with continuous concentration gradients, or as well-separated layers of specific composition. While individual ices have been studied in great detail under pressure, the properties of their mixtures are much less explored. We show here, using first-principles calculations, that the 2:1 ammonia hydrate, (H 2 O)(NH 3 ) 2 , is stabilized at icy planet mantle conditions due to a remarkable structural evolution. Above 65 GPa, we predict it will transform from a hydrogen-bonded molecular solid into a fully ionic phase O 2- ([Formula: see text]) 2 , where all water molecules are completely deprotonated, an unexpected bonding phenomenon not seen before. Ammonia hemihydrate is stable in a sequence of ionic phases up to 500 GPa, pressures found deep within Neptune-like planets, and thus at higher pressures than any other ammonia-water mixture. This suggests it precipitates out of any ammonia-water mixture at sufficiently high pressures and thus forms an important component of icy planets.

Long-term ammonia removal in a coconut fiber-packed biofilter: analysis of N fractionation and reactor performance under steady-state and transient conditions.

PubMed

Baquerizo, Guillermo; Maestre, Juan P; Machado, Vinicius C; Gamisans, Xavier; Gabriel, David

2009-05-01

A comprehensive study of long-term ammonia removal in a biofilter packed with coconut fiber is presented under both steady-state and transient conditions. Low and high ammonia loads were applied to the reactor by varying the inlet ammonia concentration from 90 to 260 ppm(v) and gas contact times ranging from 20 to 36 s. Gas samples and leachate measurements were periodically analyzed and used for characterizing biofilter performance in terms of removal efficiency (RE) and elimination capacity (EC). Also, N fractions in the leachate were quantified to both identify the experimental rates of nitritation and nitratation and to determine the N leachate distribution. Results showed stratification in the biofilter activity and, thus, most of the NH(3) removal was performed in the lower part of the reactor. An average EC of 0.5 kg N-NH(3)m(-3)d(-1) was obtained for the whole reactor with a maximum local average EC of 1.7 kg N-NH(3)m(-3)d(-1). Leachate analyses showed that a ratio of 1:1 of ammonium and nitrate ions in the leachate was obtained throughout steady-state operation at low ammonia loads with similar values for nitritation and nitratation rates. Low nitratation rates during high ammonia load periods occurred because large amounts of ammonium and nitrite accumulated in the packed bed, thus causing inhibition episodes on nitrite-oxidizing bacteria due to free ammonia accumulation. Mass balances showed that 50% of the ammonia fed to the reactor was oxidized to either nitrite or nitrate and the rest was recovered as ammonium indicating that sorption processes play a fundamental role in the treatment of ammonia by biofiltration.

Ammonia transformations and abundance of ammonia oxidizers in a clay soil underlying a manure pond.

PubMed

Sher, Yonatan; Baram, Shahar; Dahan, Ofer; Ronen, Zeev; Nejidat, Ali

2012-07-01

Unlined manure ponds are constructed on clay soil worldwide to manage farm waste. Seepage of ammonia-rich liquor into underlying soil layers contributes to groundwater contamination by nitrate. To identify the possible processes that lead to the production of nitrate from ammonia in this oxygen-limited environment, we studied the diversity and abundance of ammonia-transforming microorganisms under an unlined manure pond. The numbers of ammonia-oxidizing bacteria and anammox bacteria were most abundant in the top of the soil profile and decreased significantly with depth (0.5 m), correlating with soil pore-water ammonia concentrations and soil ammonia concentrations, respectively. On the other hand, the numbers of ammonia-oxidizing archaea were relatively constant throughout the soil profile (10(7) amoA copies per g(soil)). Nitrite-oxidizing bacteria were detected mainly in the top 0.2 m. The results suggest that nitrate accumulation in the vadose zone under the manure pond could be the result of complete aerobic nitrification (ammonia oxidation to nitrate) and could exist as a byproduct of anammox activity. While the majority of the nitrogen was removed within the 0.5-m soil section, possibly by combined anammox and heterotrophic denitrification, a fraction of the produced nitrate leached into the groundwater. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Numerical Study of Ammonia Leak and Dispersion in the International Space Station

NASA Technical Reports Server (NTRS)

Son, Chang H.

2012-01-01

Release of ammonia into the International Space Station (ISS) cabin atmosphere can occur if the water/ammonia barrier breach of the active thermal control system (ATCS) interface heat exchanger (IFHX) happens. After IFHX breach liquid ammonia is introduced into the water-filled internal thermal control system (ITCS) and then to the cabin environment through a ruptured gas trap. Once the liquid water/ammonia mixture exits ITCS, it instantly vaporizes and mixes with the U.S. Laboratory cabin air that results in rapid deterioration of the cabin conditions. The goal of the study is to assess ammonia propagation in the Station after IFHX breach to plan the operation procedure. A Computational Fluid Dynamics (CFD) model for accurate prediction of airflow and ammonia transport within each of the modules in the ISS cabin was developed. CFD data on ammonia content in the cabin aisle way of the ISS and, in particular, in the Russian On- Orbit Segment during the period of 15 minutes after gas trap rupture are presented for four scenarios of rupture response. Localized effects of ammonia dispersion and risk mitigation are discussed.

Ammonia-Oxidizing Archaea Show More Distinct Biogeographic Distribution Patterns than Ammonia-Oxidizing Bacteria across the Black Soil Zone of Northeast China.

PubMed

Liu, Junjie; Yu, Zhenhua; Yao, Qin; Sui, Yueyu; Shi, Yu; Chu, Haiyan; Tang, Caixian; Franks, Ashley E; Jin, Jian; Liu, Xiaobing; Wang, Guanghua

2018-01-01

Black soils (Mollisols) of northeast China are highly productive and agriculturally important for food production. Ammonia-oxidizing microbes play an important role in N cycling in the black soils. However, the information related to the composition and distribution of ammonia-oxidizing microbes in the black soils has not yet been addressed. In this study, we used the amoA gene to quantify the abundance and community composition of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) across the black soil zone. The amoA abundance of AOA was remarkably larger than that of AOB, with ratios of AOA/AOB in the range from 3.1 to 91.0 across all soil samples. The abundance of AOA amoA was positively correlated with total soil C content ( p < 0.001) but not with soil pH ( p > 0.05). In contrast, the abundance of AOB amoA positively correlated with soil pH ( p = 0.009) but not with total soil C. Alpha diversity of AOA did not correlate with any soil parameter, however, alpha diversity of AOB was affected by multiple soil factors, such as soil pH, total P, N, and C, available K content, and soil water content. Canonical correspondence analysis indicated that the AOA community was mainly affected by the sampling latitude, followed by soil pH, total P and C; while the AOB community was mainly determined by soil pH, as well as total P, C and N, water content, and sampling latitude, which highlighted that the AOA community was more geographically distributed in the black soil zone of northeast China than AOB community. In addition, the pairwise analyses showed that the potential nitrification rate (PNR) was not correlated with alpha diversity but weakly positively with the abundance of the AOA community ( p = 0.048), whereas PNR significantly correlated positively with the richness ( p = 0.003), diversity ( p = 0.001) and abundance ( p < 0.001) of the AOB community, which suggested that AOB community might make a greater contribution to nitrification than AOA

Ammonia-Oxidizing Archaea Show More Distinct Biogeographic Distribution Patterns than Ammonia-Oxidizing Bacteria across the Black Soil Zone of Northeast China

PubMed Central

Liu, Junjie; Yu, Zhenhua; Yao, Qin; Sui, Yueyu; Shi, Yu; Chu, Haiyan; Tang, Caixian; Franks, Ashley E.; Jin, Jian; Liu, Xiaobing; Wang, Guanghua

2018-01-01

Black soils (Mollisols) of northeast China are highly productive and agriculturally important for food production. Ammonia-oxidizing microbes play an important role in N cycling in the black soils. However, the information related to the composition and distribution of ammonia-oxidizing microbes in the black soils has not yet been addressed. In this study, we used the amoA gene to quantify the abundance and community composition of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) across the black soil zone. The amoA abundance of AOA was remarkably larger than that of AOB, with ratios of AOA/AOB in the range from 3.1 to 91.0 across all soil samples. The abundance of AOA amoA was positively correlated with total soil C content (p < 0.001) but not with soil pH (p > 0.05). In contrast, the abundance of AOB amoA positively correlated with soil pH (p = 0.009) but not with total soil C. Alpha diversity of AOA did not correlate with any soil parameter, however, alpha diversity of AOB was affected by multiple soil factors, such as soil pH, total P, N, and C, available K content, and soil water content. Canonical correspondence analysis indicated that the AOA community was mainly affected by the sampling latitude, followed by soil pH, total P and C; while the AOB community was mainly determined by soil pH, as well as total P, C and N, water content, and sampling latitude, which highlighted that the AOA community was more geographically distributed in the black soil zone of northeast China than AOB community. In addition, the pairwise analyses showed that the potential nitrification rate (PNR) was not correlated with alpha diversity but weakly positively with the abundance of the AOA community (p = 0.048), whereas PNR significantly correlated positively with the richness (p = 0.003), diversity (p = 0.001) and abundance (p < 0.001) of the AOB community, which suggested that AOB community might make a greater contribution to nitrification than AOA community

Defences against ammonia toxicity in tropical air-breathing fishes exposed to high concentrations of environmental ammonia: a review.

PubMed

Ip, Y K; Chew, S F; Wilson, J M; Randall, D J

2004-10-01

In the tropics, air-breathing fishes can be exposed to environmental ammonia when stranded in puddles of water during the dry season, during a stay inside a burrow, or after agricultural fertilization. At low concentrations of environmental ammonia, NH(3) excretion is impeded, as in aerial exposure, leading to the accumulation of endogenous ammonia. At high concentrations of environmental ammonia, which results in a reversed NH(3) partial pressure gradient (DeltaP(NH3)), there is retention of endogenous ammonia and uptake of exogenous ammonia. In this review, several tropical air-breathing fishes (giant mudskipper, African catfish, oriental weatherloach, swamp eel, four-eyed sleeper, abehaze and slender African lungfish), which can tolerate high environmental ammonia exposure, are used as examples to demonstrate how eight different adaptations can be involved in defence against ammonia toxicity. Four of these adaptations deal with ammonia toxicity at branchial and/or epithelial surfaces: (1) active excretion of NH(4)(+); (2) lowering of environmental pH; (3) low NH(3) permeability of epithelial surfaces; and (4) volatilization of NH(3), while another four adaptations ameliorate ammonia toxicity at the cellular and subcellular levels: (5) high tolerance of ammonia at the cellular and subcellular levels; (6) reduction in ammonia production; (7) glutamine synthesis; and (8) urea synthesis. The responses of tropical air-breathing fishes to high environmental ammonia are determined apparently by behavioural adaptations and the nature of their natural environments.

Nitrification resilience and community dynamics of ammonia-oxidizing bacteria with respect to ammonia loading shock in a nitrification reactor treating steel wastewater.

PubMed

Cho, Kyungjin; Shin, Seung Gu; Lee, Joonyeob; Koo, Taewoan; Kim, Woong; Hwang, Seokhwan

2016-08-01

The aim of this study was to investigate the nitrification resilience pattern and examine the key ammonia-oxidizing bacteria (AOB) with respect to ammonia loading shocks (ALSs) in a nitrification bioreactor treating steel wastewater. The perturbation experiments were conducted in a 4-L bioreactor operated in continuous mode with a hydraulic retention time of 10 d. Three sequential ALSs were given to the bioreactor (120, 180 and 180 mg total ammonia nitrogen (TAN)/L. When the first shock was given, the nitrification process completely recovered after 14 d of further operation. However, the resilience duration was significantly reduced to ∼1 d after the second and third ALSs. In the bioreactor, Nitrosomonas aestuarii dominated the other AOB species, Nitrosomonas europaea and N. nitrosa, throughout the process. In addition, the population of N. aestuarii increased with ammonia utilization following each ALS; i.e., this species responded to acute ammonia overloadings by contributing to ammonia oxidation. This finding suggests that N. aestuarii could be exploited to achieve stable nitrification in industrial wastewaters that contain high concentrations of ammonia. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Growth of ammonia-oxidizing archaea and bacteria in cattle manure compost under various temperatures and ammonia concentrations.

PubMed

Oishi, Ryu; Tada, Chika; Asano, Ryoki; Yamamoto, Nozomi; Suyama, Yoshihisa; Nakai, Yutaka

2012-05-01

A recent study showed that ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) coexist in the process of cattle manure composting. To investigate their physiological characteristics, liquid cultures seeded with fermenting cattle manure compost were incubated at various temperatures (37°C, 46°C, or 60°C) and ammonium concentrations (0.5, 1, 4, or 10 mM NH (4) (+) -N). The growth rates of the AOB and AOA were monitored using real-time polymerase chain reaction analysis targeting the bacterial and archaeal ammonia monooxygenase subunit A genes. AOB grew at 37°C and 4 or 10 mM NH (4) (+) -N, whereas AOA grew at 46°C and 10 mM NH (4) (+) -N. Incubation with allylthiourea indicated that the AOB and AOA grew by oxidizing ammonia. Denaturing gradient gel electrophoresis and subsequent sequencing analyses revealed that a bacterium related to Nitrosomonas halophila and an archaeon related to Candidatus Nitrososphaera gargensis were the predominant AOB and AOA, respectively, in the seed compost and in cultures after incubation. This is the first report to demonstrate that the predominant AOA in cattle manure compost can grow and can probably oxidize ammonia under moderately thermophilic conditions.

Ammonia Synthesis at Low Pressure.

PubMed

Cussler, Edward; McCormick, Alon; Reese, Michael; Malmali, Mahdi

2017-08-23

Ammonia can be synthesized at low pressure by the use of an ammonia selective absorbent. The process can be driven with wind energy, available locally in areas requiring ammonia for synthetic fertilizer. Such wind energy is often called "stranded," because it is only available far from population centers where it can be directly used. In the proposed low pressure process, nitrogen is made from air using pressure swing absorption, and hydrogen is produced by electrolysis of water. While these gases can react at approximately 400 °C in the presence of a promoted conventional catalyst, the conversion is often limited by the reverse reaction, which makes this reaction only feasible at high pressures. This limitation can be removed by absorption on an ammine-like calcium or magnesium chloride. Such alkaline metal halides can effectively remove ammonia, thus suppressing the equilibrium constraints of the reaction. In the proposed absorption-enhanced ammonia synthesis process, the rate of reaction may then be controlled not by the chemical kinetics nor the absorption rates, but by the rate of the recycle of unreacted gases. The results compare favorably with ammonia made from a conventional small scale Haber-Bosch process.

Conversion of ammonia into hydrogen and nitrogen by reaction with a sulfided catalyst

DOEpatents

Matthews, Charles W.

1977-01-01

A method is provided for removing ammonia from the sour water stream of a coal gasification process. The basic steps comprise stripping the ammonia from the sour water; heating the stripped ammonia to a temperature from between 400.degree. to 1,000.degree. F; passing the gaseous ammonia through a reactor containing a sulfided catalyst to produce elemental hydrogen and nitrogen; and scrubbing the reaction product to obtain an ammonia-free gas. The residual equilibrium ammonia produced by the reactor is recycled into the stripper. The ammonia-free gas may be advantageously treated in a Claus process to recover elemental sulfur. Iron sulfide or cobalt molybdenum sulfide catalysts are used.

Solar Metal Sulfate-Ammonia Based Thermochemical Water Splitting Cycle for Hydrogen Production

NASA Technical Reports Server (NTRS)

T-Raissi, Ali (Inventor); Muradov, Nazim (Inventor); Huang, Cunping (Inventor)

2014-01-01

Two classes of hybrid/thermochemical water splitting processes for the production of hydrogen and oxygen have been proposed based on (1) metal sulfate-ammonia cycles (2) metal pyrosulfate-ammonia cycles. Methods and systems for a metal sulfate MSO.sub.4--NH3 cycle for producing H2 and O2 from a closed system including feeding an aqueous (NH3)(4)SO3 solution into a photoctalytic reactor to oxidize the aqueous (NH3)(4)SO3 into aqueous (NH3)(2)SO4 and reduce water to hydrogen, mixing the resulting aqueous (NH3)(2)SO4 with metal oxide (e.g. ZnO) to form a slurry, heating the slurry of aqueous (NH4)(2)SO4 and ZnO(s) in the low temperature reactor to produce a gaseous mixture of NH3 and H2O and solid ZnSO4(s), heating solid ZnSO4 at a high temperature reactor to produce a gaseous mixture of SO2 and O2 and solid product ZnO, mixing the gaseous mixture of SO2 and O2 with an NH3 and H2O stream in an absorber to form aqueous (NH4)(2)SO3 solution and separate O2 for aqueous solution, recycling the resultant solution back to the photoreactor and sending ZnO to mix with aqueous (NH4)(2)SO4 solution to close the water splitting cycle wherein gaseous H2 and O2 are the only products output from the closed ZnSO4--NH3 cycle.

Autotrophic nitrogen removal process in a potable water treatment biofilter that simultaneously removes Mn and NH4(+)-N.

PubMed

Cai, Yan'an; Li, Dong; Liang, Yuhai; Zeng, Huiping; Zhang, Jie

2014-11-01

Ammonia (NH4(+)-N) removal pathways were investigated in a potable water treatment biofilter that simultaneously removes manganese (Mn) and NH4(+)-N. The results indicated a significant loss of nitrogen in the biofilter. Both the completely autotrophic nitrogen removal over nitrite (CANON) process and nitrification were more likely to contribute to NH4(+)-N removal. Moreover, the model calculation results demonstrated that the CANON process contributed significantly to the removal of NH4(+)-N. For influent NH4(+)-N levels of 1.030 and 1.749mg/L, the CANON process contribution was about 48.5% and 46.6%, respectively. The most important finding was that anaerobic ammonia oxidation (ANAMMOX) bacteria were detectable in the biofilter. It is interesting that the CANON process was effective even for such low NH4(+)-N concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ammonia removal in the carbon contactor of a hybrid membrane process.

PubMed

Stoquart, Céline; Servais, Pierre; Barbeau, Benoit

2014-12-15

The hybrid membrane process (HMP) coupling powdered activated carbon (PAC) and low-pressure membrane filtration is emerging as a promising new option to remove dissolved contaminants from drinking water. Yet, defining optimal HMP operating conditions has not been confirmed. In this study, ammonia removal occurring in the PAC contactor of an HMP was simulated at lab-scale. Kinetics were monitored using three PAC concentrations (1-5-10 g L(-1)), three PAC ages (0-10-60 days), two temperatures (7-22 °C), in ambient influent condition (100 μg N-NH4 L(-1)) as well as with a simulated peak pollution scenario (1000 μg N-NH4L(-1)). The following conclusions were drawn: i) Using a colonized PAC in the HMP is essential to reach complete ammonia removal, ii) an older PAC offers a higher resilience to temperature decrease as well as lower operating costs; ii) PAC concentration inside the HMP reactor is not a key operating parameter as under the conditions tested, PAC colonization was not limited by the available surface; iii) ammonia flux limited biomass growth and iv) hydraulic retention time was a critical parameter. In the case of a peak pollution, the process was most probably phosphate-limited but a mixed adsorption/nitrification still allowed reaching a 50% ammonia removal. Finally, a kinetic model based on these experiments is proposed to predict ammonia removal occurring in the PAC reactor of the HMP. The model determines the relative importance of the adsorption and biological oxidation of ammonia on colonized PAC, and demonstrates the combined role of nitrification and residual adsorption capacity of colonized PAC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Numerical analysis of ammonia homogenization for selective catalytic reduction application.

PubMed

Baleta, Jakov; Martinjak, Matija; Vujanović, Milan; Pachler, Klaus; Wang, Jin; Duić, Neven

2017-12-01

Selective catalytic reduction based on urea water solution as ammonia precursor is a promising method for the NO x abatement form exhaust gasses of mobile diesel engine units. It consists of injecting the urea-water solution in the hot flue gas stream and reaction of its products with the NO x over the catalyst surface. During this process flue gas enthalpy is used for the urea-water droplet heating and for the evaporation of water content. After water evaporates, thermolysis of urea occurs, during which ammonia, a known NO x reductant, and isocyanic acid are generated. The uniformity of the ammonia before the catalyst as well as ammonia slip to the environment are important counteracting design requirements, optimization of which is crucial for development of efficient deNO x systems. The aim of this paper is to show capabilities of the developed mathematical framework implemented in the commercial CFD code AVL FIRE ® , to simulate physical processes of all relevant phenomena occurring during the SCR process including chemical reactions taking part in the catalyst. First, mathematical models for description of SCR process are presented and afterwards, models are used on the 3D geometry of a real SCR reactor in order to predict ammonia generation, NO x reduction and resulting ammonia slip. Influence of the injection direction and droplet sizes was also investigated on the same geometry. The performed study indicates importance of droplet sizes on the SCR process and shows that counterflow injection is beneficial, especially in terms of minimizing harmful ammonia slip to environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Timing and magnitude of C partitioning through a young loblolly pine ( Pinus taeda L.) stand using 13C labeling and shade treatments

DOE PAGES

Warren, Jeffrey M.; Iversen, Colleen M.; Garten, Jr., Charles T.; ...

2011-12-30

The dynamics of rapid changes in carbon (C) partitioning within forest ecosystems are not well understood, which limits improvement of mechanistic models of C cycling. Our objective was to inform model processes by describing relationships between C partitioning and accessible environmental or physiological measurements, with a special emphasis on short-term C flux through a forest ecosystem. We exposed eight 7-year-old loblolly pine ( Pinus taeda L.) trees to air enriched with 13CO 2 and then implemented adjacent light shade (LS) and heavy shade (HS) treatments in order to manipulate C uptake and flux. The impacts of shading on photosynthesis, plantmore » water potential, sap flow, basal area growth, root growth, and soil CO 2 efflux rate (CER) were assessed for each tree over a three-week period. The progression of the 13C label was concurrently tracked from the atmosphere through foliage, phloem, roots, and surface soil CO 2 efflux. The HS treatment significantly reduced C uptake, sap flow, stem growth and fine root standing crop, and resulted in greater residual soil water content to 1 m depth. Sap flow was strongly correlated with CER on the previous day, but not the current day, with no apparent treatment effect on the relationship. Although there were apparent reductions in new C flux belowground, the heavy shade treatment did not noticeably reduce the magnitude of belowground autotrophic and heterotrophic respiration based on surface soil CO 2 efflux rate (CER), which was overwhelmingly driven by soil temperature and moisture. The 13C label was immediately detected in foliage on label day (half-life = 0.5 d), progressed through phloem by day 2 (half-life = 4.7 d), roots by day 2-4, and subsequently was evident as respiratory release from soil which peaked between days 3-6. The δ 13C of soil CO 2 efflux was strongly correlated with phloem 13C on the previous day, or two days earlier. While the 13C label was readily tracked through the ecosystem, the fate

Formation of Nitrogen and Hydrogen-bearing Molecules in Solid Ammonia and Implications for Solar System and Interstellar Ices

NASA Astrophysics Data System (ADS)

Zheng, Weijun; Jewitt, David; Osamura, Yoshihiro; Kaiser, Ralf I.

2008-02-01

We irradiated solid ammonia (NH3) in the temperature range of 10-60 K with high-energy electrons to simulate the processing of ammonia-bearing ices in the interstellar medium and in the solar system. By monitoring the newly formed molecules online and in situ, the synthesis of hydrazine (N2H4), diazene (N2H2 isomers), hydrogen azide (HN3), the amino radical (NH2), molecular hydrogen (H2), and molecular nitrogen (N2) has been confirmed. Our results show that the production rates of hydrazine, diazene, hydrogen azide, molecular hydrogen, and molecular nitrogen are higher in amorphous ammonia than those in crystalline ammonia; this behavior is similar to the production of molecular hydrogen, molecular oxygen, and hydrogen peroxide found in electron-irradiated water ices. However, the formation of hydrazine in crystalline ammonia does not show any temperature dependence. Our experimental results give hints to the origin of molecular nitrogen in the Saturnian system and possibly in the atmospheres of proto-Earth and Titan; our research may also guide the search of hitherto unobserved nitrogen-bearing molecules in the interstellar medium and in our solar system.

The effect of elevated atmospheric CO2 concentration on gross nitrogen and carbon dynamics in a permanent grassland: A field pulse-labeling study

NASA Astrophysics Data System (ADS)

Moser, Gerald; Gorenflo, André; Keidel, Lisa; Brenzinger, Kristof; Elias, Dafydd; McNamara, Niall; Maček, Irena; Vodnik, Dominik; Braker, Gesche; Schimmelpfennig, Sonja; Gerstner, Judith; Müller, Christoph

2014-05-01

To predict ecosystem reactions to elevated atmospheric CO2 (eCO2) it is essential to understand the interactions between plant carbon input, microbial community composition and activity and associated nutrient dynamics. Long-term observations (> 14 years) within the Giessen Free Air Carbon dioxide Enrichment (Giessen FACE) study on permanent grassland showed next to an enhanced biomass production an unexpected strong positive feedback effect on ecosystem respiration and nitrous oxide (N2O) production. The overall goal of this study is to understand the long-term effects of eCO2 and carbon input on microbial community composition and activity as well as the associated nitrogen dynamics, N2O production and plant N uptake in the Giessen FACE study on permanent grassland. A combination of 13CO2 pulse labelling with 15N tracing of 15NH4+ and 15NO3- was carried out in situ. Different fractions of soil organic matter (recalcitrant, labile SOM) and the various mineral N pools in the soil (NH4+, NO3-), gross N transformation rates, pool size dependent N2O and N2 emissions as well as N species dependent plant N uptake rates and the origin of the CO2 respiration have been quantified. Microbial analyses include exploring changes in the composition of microbial communities involved in the turnover of NH4+, NO3-, N2O and N2, i.e. ammonia oxidizing, denitrifying, and microbial communities involved in dissimilatory nitrate reduction to ammonia (DNRA). mRNA based analyses will be employed to comparably evaluate the long-term effects of eCO2 on the structure and abundance of these communities, while transcripts of these genes will be used to target the fractions of the communities which actively contribute to N transformations. We quantified the contribution of mycorrhizae on N2O emissions and observed the phenological development of the mycorrhizae after the labeling.