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1

Mechanism by which ammonium bicarbonate and ammonium sulfate inhibit mycotoxigenic fungi.  

PubMed Central

In this study we examined the mechanism by which ammonium bicarbonate inhibits mycotoxigenic fungi. Elevated extracellular pH, alone, was not responsible for the antifungal activity. Although conidia of Penicillium griseofulvum and Fusarium graminearum had internal pH (pHi) values as high as 8.0 in buffer at an external pH (pHo) of 9.5, their viability was not markedly affected. The pHi values from conidia equilibrated in glycine-NaOH-buffered treatments without ammonium bicarbonate or ammonium sulfate were similar to values obtained from buffered treatments containing the ammonium salts. Thus, inhibition did not appear to be directly related to increased pHi. Ammonium sulfate in buffered media at pH greater than or equal to 8.7 was as inhibitory as ammonium bicarbonate, but was completely ineffective at pH less than or equal to 7.8. The hypothesis that free ammonia caused the fungal inhibition was tested by using ammonium sulfate as a model for ammonium bicarbonate. Viability, expressed as log CFU/ml, and percent germination of P. griseofulvum and F. graminearum decreased dramatically as the free ammonia concentration increased. Germination rate ratios (the germination rate in buffered ammonium sulfate divided by the germination rate in buffer alone) decreased linearly as the free ammonia concentration increased, further establishing NH3 as the toxic agent. Ammonium bicarbonate inhibits fungi because the bicarbonate anion supplies the alkalinity necessary to establish an antifungal concentration of free ammonia. PMID:2082821

DePasquale, D A; Montville, T J

1990-01-01

2

40 CFR 180.1244 - Ammonium bicarbonate; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Ammonium bicarbonate; exemption from the requirement of...Tolerances § 180.1244 Ammonium bicarbonate; exemption from the requirement of...established for residues of ammonium bicarbonate used in or on all food...

2010-07-01

3

The influence of carbon dioxide, bicarbonate and other buffers on the potential of antimony microelectrodes  

Microsoft Academic Search

Summary Antimony microelectrodes were calibrated at 37° C in phosphate buffers, in different bicarbonate solutions at various CO2-partial pressures and in buffers like TRIS, TES, MES and malonic acid. By use of the latter buffers (with exception of malonic acid) the most reliable calibration curves were obtained (“normal values”). The usual calibration in 67 mmol\\/l standard phosphate buffers turned out

P. Quehenberger; S. David

1977-01-01

4

The influence of carbon dioxide, bicarbonate and other buffers on the potential of antimony microelectrodes.  

PubMed

Antimony microelectrodes were calibrated at 37 degrees C in phosphate buffers, in different bicarbonate solutions at various CO2-partial pressures and in buffers like TRIS1, TES2, MES3 and malonic acid. By use of the latter buffers (with exception of malonic acid) the most reliable calibration curves were obtained ("normal values"). The usual calibration in 67 mmol/l standard phosphate buffers turned out to be unacceptable because the obtained mV-values were too high (negative) in comparison to all other buffers. Different calibration curves resulted from the use of pure bicarbonate solution whether the pH-values were changed by variation of pCO2 or of the bicarbonate concentration. Low bicarbonate concentrations in combination with low pCO2 gave mV-values which were too low relative to the other buffers. Both the increase of pCO2 as well as of the bicarbonate concentration caused a shift of the potential of the antimony electrodes toward "normal values". In solutions containing other buffers the influence of bicarbonate and pCO2 became negligible with increasing buffer concentration. Decreasing oxygen partial pressure was found to cause an increase of the potential of the antimony electrodes. The influence of liquid junction potentials at the reference electrode is discussed. PMID:558586

Quehenberger, P

1977-03-11

5

Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy  

E-print Network

Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy Geoffrey M 16802, United States *S Supporting Information ABSTRACT: Many salinity gradient energy technologies recovery using AmB thermolytic solutions in RED. Recent interest in salinity gradient energy technologies

6

ELECTROANTENNOGRAM RESPONSE OF ANASTREPHA SUSPENSA (DIPTERA: TEPHRITIDAE) TO AMMONIUM BICARBONATE AND PUTRESCINE LURES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Current trapping systems for Anastrepha fruit flies utilize a two-component attractant consisting of ammonium bicarbonate and putrescine. Though ammonia-based lures have been highly effective for some tephritids (e.g. Mediterranean fruit fly, Ceratitis capitata), attraction of Anastrepha species has...

7

Author's personal copy Evaluation of stainless steel cathodes and a bicarbonate buffer  

E-print Network

Author's personal copy Evaluation of stainless steel cathodes and a bicarbonate buffer for hydrogen, University Park, PA 16802, USA a r t i c l e i n f o Article history: Received 6 August 2010 Received) catalyst. Stainless steel (SS) has been shown to be an effective catalyst for hydrogen evolution in MECs

8

Iron deficiency studies of sugar beet using an improved sodium bicarbonate?buffered hydroponic growth system  

Microsoft Academic Search

A sodium bicarbonate (NaHCO3)?buffered hydroponic growth system was developed that simulates alkaline soil growth conditions necessary to screen sugar beet genotypes for iron (Fe) efficiency character. Three genotypes (NB1, NB4, and F, hybrid, NB 1xNB4) with differing capacities for Strategy I Fe responses were phenotyped successfully using this system. Genotypes NB1 and NB1xNB4 are Fe efficient, while NB4 is Fe

Scott A. Campbell; John N. Nishio

2000-01-01

9

EFFECTS OF LIMESTONE AND SODIUM BICARBONATE BUFFERS ON RUMEN MEASUREMENTS AND RATE OF PASSAGE IN CATTLE  

Microsoft Academic Search

Summary Eight rumen-fistulated cattle (four Angus steers and four nonlactating Holstein cows) were fed a cracked corn-based concentrate (65% of dry matter) and corn silage (35% of dry matter) diet containing: (1) no buffer, (2) 2.5% limestone, (3) 2% sodium bicarbonate (NaHCO3) or (4) 1.25% limestone and 1.25% NaHCO3. Each diet was fed at approximately maintenance and-two times maintenance levels

G. L. Haaland; H. F. Tyrrell

10

Electrooxidation\\/electroreduction processes at composite iron hydroxide layers in carbonate-bicarbonate buffers  

Microsoft Academic Search

The electrooxidation\\/electroreduction processes at precipitated iron hydroxide layers on platinum electrodes have been studied in carbonate-bicarbonate buffers at 25°C by using electrochemical methods. The initial characteristics and properties of the hydrous iron hydroxide were changed by varying the precipitation conditions of the chemically formed active materials. Different potentialtime perturbation programs were employed to analyse the contribution of redox couples within

E. B. Castro; J. R. Vilche

1991-01-01

11

Fruit Yield of Tomato Cultivated on Media with Bicarbonate and Nitrate\\/Ammonium as the Nitrogen Source  

Microsoft Academic Search

This article presents the effects of nitrate\\/ammonium (NO3 \\/NH4 ), applied at different proportions to the root media with or without 5 mmol bicarbonate (HCO3 ), on the yield and chemical composition of tomato fruit. Tomato plants were grown hydroponically (pH 6.9) in glasshouse conditions. The yield of fruit fresh matter from four clusters obtained from plants grown on the

Jan Bialczyk; Zbigniew Lechowski; Dariusz Dziga; Ewa Mej

2007-01-01

12

Antennal and behavioral responses to putrescine and ammonium bicarbonate in the Caribbean fruit fly (Diptera: tephritidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

A current trapping system for Anastrepha fruit flies uses a 2-component lure that emits ammonia and putrescine, both regarded as protein cues. This study used electroantennography and flight tunnel bioassays to quantify olfactory and behavioral responses of A. suspensa to vapors from ammonium bicar...

13

Coral reef calcifiers buffer their response to ocean acidification using both bicarbonate and carbonate  

PubMed Central

Central to evaluating the effects of ocean acidification (OA) on coral reefs is understanding how calcification is affected by the dissolution of CO2 in sea water, which causes declines in carbonate ion concentration [CO32?] and increases in bicarbonate ion concentration [HCO3?]. To address this topic, we manipulated [CO32?] and [HCO3?] to test the effects on calcification of the coral Porites rus and the alga Hydrolithon onkodes, measured from the start to the end of a 15-day incubation, as well as in the day and night. [CO32?] played a significant role in light and dark calcification of P. rus, whereas [HCO3?] mainly affected calcification in the light. Both [CO32?] and [HCO3?] had a significant effect on the calcification of H. onkodes, but the strongest relationship was found with [CO32?]. Our results show that the negative effect of declining [CO32?] on the calcification of corals and algae can be partly mitigated by the use of HCO3? for calcification and perhaps photosynthesis. These results add empirical support to two conceptual models that can form a template for further research to account for the calcification response of corals and crustose coralline algae to OA. PMID:23256193

Comeau, S.; Carpenter, R. C.; Edmunds, P. J.

2013-01-01

14

Coral reef calcifiers buffer their response to ocean acidification using both bicarbonate and carbonate.  

PubMed

Central to evaluating the effects of ocean acidification (OA) on coral reefs is understanding how calcification is affected by the dissolution of CO(2) in sea water, which causes declines in carbonate ion concentration [CO(3)(2-)] and increases in bicarbonate ion concentration [HCO(3)(-)]. To address this topic, we manipulated [CO(3)(2-)] and [HCO(3)(-)] to test the effects on calcification of the coral Porites rus and the alga Hydrolithon onkodes, measured from the start to the end of a 15-day incubation, as well as in the day and night. [CO(3)(2-)] played a significant role in light and dark calcification of P. rus, whereas [HCO(3)(-)] mainly affected calcification in the light. Both [CO(3)(2-)] and [HCO(3)(-)] had a significant effect on the calcification of H. onkodes, but the strongest relationship was found with [CO(3)(2-)]. Our results show that the negative effect of declining [CO(3)(2-)] on the calcification of corals and algae can be partly mitigated by the use of HCO(3)(-) for calcification and perhaps photosynthesis. These results add empirical support to two conceptual models that can form a template for further research to account for the calcification response of corals and crustose coralline algae to OA. PMID:23256193

Comeau, S; Carpenter, R C; Edmunds, P J

2013-02-22

15

Accelerating the dissolution of enteric coatings in the upper small intestine: evolution of a novel pH 5.6 bicarbonate buffer system to assess drug release.  

PubMed

Despite rapid dissolution in compendial phosphate buffers, gastro resistant (enteric coated) products can take up to 2 h to disintegrate in the human small intestine, which clearly highlights the inadequacy of the in vitro test method to predict in vivo behaviour of these formulations. The aim of this study was to establish the utility of a novel pH 5.6 bicarbonate buffer, stabilized by an Auto pH™ System, as a better surrogate of the conditions of the proximal small intestine to investigate the dissolution behaviour of standard and accelerated release enteric double coating formulations. Prednisolone tablets were coated with 3 or 5 mg/cm(2) of partially neutralized EUDRAGIT(®) L 30 D-55, HP-55 or HPMC adjusted to pH 6 or 8. An outer layer of EUDRAGIT(®) L 30 D-55 was applied at 5mg/cm(2). For comparison purposes, a standard single layer of EUDRAGIT(®) L 30 D-55 was applied to the tablets. Dissolution was carried out using USP II apparatus in 0.1 M HCl for 2 h, followed by pH 5.6 bicarbonate buffer. EUDRAGIT(®) L 30 D-55 single-coated tablets showed a slow drug release with a lag time of 75 min in buffer, whereas release from the EUDRAGIT(®) L 30 D-55 double-coated tablets was accelerated. These in vitro lag times closely match the in vivo disintegration times for these coated tablets reported previously. Drug release was further accelerated from modified double coatings, particularly in the case of coatings with a thinner inner layer of HP-55 or HPMC (pH 8 and KH2PO4). This study confirms that the pH 5.6 bicarbonate buffer system offers significant advantages during the development of dosage forms designed to release the drug in the upper small intestine. PMID:24727141

Varum, Felipe J O; Merchant, Hamid A; Goyanes, Alvaro; Assi, Pardis; Zboranová, Veronika; Basit, Abdul W

2014-07-01

16

Magnesium bicarbonate as an in situ uranium lixiviant  

SciTech Connect

In the subsurface solution mining of mineral values, especially uranium, in situ, magnesium bicarbonate leaching solution is used instead of sodium, potassium and ammonium carbonate and bicarbonates. The magnesium bicarbonate solution is formed by combining carbon dioxide with magnesium oxide and water. The magnesium bicarbonate lixivant has four major advantages over prior art sodium, potassium and ammonium bicarbonates.

Sibert, J.W.

1984-09-25

17

Predicting the gastrointestinal behaviour of modified-release products: Utility of a novel dynamic dissolution test apparatus involving the use of bicarbonate buffers.  

PubMed

The establishment of physiologically relevant in vitro-in vivo correlations (IV-IVCs) is key for any biorelevant dissolution test. Historically, bicarbonate buffers have produced better correlations than compendial phosphate buffered media, though such tests are usually performed at a constant pH experiment, overlooking the notion that the pH of the luminal fluids is variable and fluctuating. In this work, we have devised a dynamic dissolution test method employing a physiological bicarbonate buffer under pH conditions of the proximal gut in order to assess the dissolution behaviour of various enteric polymer-coated (gastro-resistant) prednisolone tablets. The pH of the media is modulated and controlled by an Auto pH System™ which exploits the physiological equilibria between [H2CO3] and [HCO3(-)], to match it to the aboral change in pH with transit of the dosage form through the proximal small intestine (from pH 5.6 up to 6.8). The lag time values for an accelerated release and standard EUDRAGIT(®) L30D-55 coated formulation (25min and 60min, respectively) were close to the previously reported initial tablet disintegration time data obtained in-vivo by ?-scintigraphy (28min and 66min, respectively). Dissolution of alternative delayed release coated products was also better discriminated in the dynamic buffer system. These data confirm the dynamic dissolution system provides a robust and reliable platform to predict the in vivo fate of oral products in a laboratory setting. PMID:25195730

Merchant, Hamid A; Goyanes, Alvaro; Parashar, Narendra; Basit, Abdul W

2014-11-20

18

Internal Active Thermal Control System (IATCS) Sodium Bicarbonate/Carbonate Buffer in an Open Aqueous Carbon Dioxide System and Corollary Electrochemical/Chemical Reactions Relative to System pH Changes  

NASA Technical Reports Server (NTRS)

The International Space Station (ISS) Internal Active Thermal Control System (IATCS) experienced a number of chemical changes driven by system absorption of CO2 which altered the coolant’s pH. The natural effects of the decrease in pH from approximately 9.2 to less than 8.4 had immediate consequences on system corrosion rates and corrosion product interactions with specified coolant constituents. The alkalinity of the system was increased through the development and implementation of a carbonate/bicarbonate buffer that would increase coolant pH to 9.0 – 10.0 and maintain pH above 9.0 in the presence of ISS cabin concentrations of CO2 up to twenty times higher than ground concentrations. This paper defines how a carbonate/bicarbonate buffer works in an open carbon dioxide system and summarizes the analyses performed on the buffer for safe and effective application in the on-orbit system. The importance of the relationship between the cabin environment and the IATCS is demonstrated as the dominant factor in understanding the system chemistry and pH trends before and after addition of the carbonate/bicarbonate buffer. The paper also documents the corollary electrochemical and chemical reactions the system has experienced and the rationale for remediation of these effects with the addition of the carbonate/bicarbonate buffer.

Stegman, Thomas W.; Wilson, Mark E.; Glasscock, Brad; Holt, Mike

2014-01-01

19

Differential responses to mitogen stimulation in lymphocytes from normal individuals and Lesch-Nyhan patients: influence of the bicarbonate buffer system.  

PubMed Central

Three patients affected with the Lesch-Nyhan syndrome were found to have normal levels of immunoglobulins, normal numbers of circulating B and T cells and normal IgG secretion in vitro in response to polyclonal activators. However, when cultures were performed in the absence of a bicarbonate buffer system, the proliferative response to several T cell stimulants (phytohaemagglutinin, concanavalin A and streptokinase-streptodornase) was impaired in Lesch-Nyhan cells as judged from the incorporation of labelled thymidine, uridine and leucine. This situation could be abolished by incubation in a 5% CO2 atmosphere and even reversed by supplementation of bicarbonate to the culture medium. Blocking the de novo purine synthesis by Methotrexate resulted in a more pronounced inhibition of the mitogenic response in Lesch-Nyhan lymphocytes than in normal cells. The differences in proliferative response between normal and Lesch-Nyhan lymphocytes with regard to culture conditions point to the critical role of the de novo pathway in lymphocyte stimulation. PMID:6970638

Gausset, P; Vamos, E; Delespesse, G; Kulakowski, S; Duchateau, J; de Bruyn, C

1980-01-01

20

Na/Bicarbonate Cotransporter NBCn1 in the Kidney Medullary Thick Ascending Limb Cell Line is Upregulated under Acidic Conditions and Enhances Ammonium Transport  

PubMed Central

In this study, we examined the effect of bicarbonate transporters on ammonium/ammonia uptake in the medullary thick ascending limb cell line ST-1. Cells were treated with 1 mM ouabain and 0.2 mM bumetanide to minimize carrier-mediated NH4+ transport, and the intracellular accumulation of 14C-methylammonium/methylammonia (MA) was determined. In CO2?HCO3?-free solution, cells at normal pH briefly accumulated 14C-MA over 7 min and reached a plateau. In CO2?HCO3? solution, however, cells markedly accumulated 14C-MA over the experiment period of 30 min. This CO2?HCO3?-dependent accumulation was reduced by the bicarbonate transporter blocker 4,4’-diisothiocyanatostilbene-2,2’-disulfonate (DIDS; 0.5 mM). Replacing Cl– with gluconate reduced the accumulation but the reduction was more substantial in the presence of DIDS. Incubating cells at pH 6.8 (adjusted with NaHCO3 in 5% CO2) for 24 h lowered the mean steady-state intracellular pH to 6.96, significantly lower than 7.28 for controls. DIDS reduced 14C-MA accumulation in controls but had no effect after acidic incubation. Immunoblot showed that NBCn1 was upregulated after acidic incubation and in NH4Cl-containing media. The Cl/HCO3 exchanger AE2 was present but its expression remained unaffected by acidic incubation. Expressed in Xenopus oocytes, NBCn1 increased carrier-mediated 14C-MA transport, which was abolished by replacing Na+. Two-electrode voltage clamp of oocytes exhibited negligible current after NH4Cl application. These results suggest that DIDS-sensitive HCO3? extrusion normally governs NH4+/NH3 uptake in the MTAL cells. We propose that, under acidic conditions, DIDS-sensitive HCO3? extrusion is inactivated while NBCn1 is upregulated to stimulate NH4+ transport. PMID:20591978

Lee, Soojung; Lee, Hye Jeong; Yang, Han Soo; Thornell, Ian M.; Bevensee, Mark O.; Choi, Inyeong

2010-01-01

21

Photo-electrochemical analysis of passive film formed on X80 pipeline steel in bicarbonate/carbonate buffer solution  

NASA Astrophysics Data System (ADS)

Photo-electrochemical measurement was used to explore the formation potential, formation time, chloride ions concentration, applied potential and pH value of the solution on the electronic property of passive film formed on X80 pipeline steel in 1 M NaHCO 3/0.5 M Na 2CO 3 buffer solution. The results showed that the photocurrent is positive, indicating an n-type semiconductor character of the passive film, the photocurrent increased with increasing the formation potential, prolonging the formation time, decreasing chloride ions concentration, rising applied potential and decreasing the pH value of the solution. Capacitance measurement exhibited a positive slope of Mott-Schottky plot, and the slopes of Mott-Schottky plots increased with the increasing formation potential, showing a decrement of the donor density of the passive film.

Li, D. G.; Feng, Y. R.; Bai, Z. Q.; Zhu, J. W.; Zheng, M. S.

2008-02-01

22

Sodium Bicarbonate  

MedlinePLUS

... is an antacid used to relieve heartburn and acid indigestion. Your doctor also may prescribe sodium bicarbonate ... doctor immediately: severe headache nausea vomit that resembles coffee grounds loss of appetite irritability weakness frequent urge ...

23

Bicarbonate Test  

MedlinePLUS

... of a low bicarbonate level include: Addison’s disease Chronic diarrhea Diabetic ketoacidosis Metabolic acidosis Kidney disease Ethylene glycol or methanol poisoning Salicylate (aspirin) overdose Increased levels may be due ...

24

Method of uranium reclamation from aqueous systems by reactive ion exchange. [US DOE patent application; anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands  

DOEpatents

A reactive ion exchange method for separation and recovery of values of uranium, neptunium, plutonium, or americium from substantially neutral aqueous systems of said metals comprises contacting said system with an effective amount of a basic anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands to achieve nearly 100% sorption of said actinyl ion onto said resin and an aqueous system practically free of said actinyl ions. The method is operational over an extensive range of concentrations from about 10/sup -6/ M to 1.0 M actinyl ion and a pH range of about 4 to 7. The method has particulr application to treatment of waste streams from Purex-type nuclear fuel reprocessing facilities and hydrometallurgical processes involving U, Np, P, or Am.

Maya, L.

1981-11-05

25

Solubility of ammonium acid urate nephroliths from bottlenose dolphins (Tursiops truncatus).  

PubMed

Nephrolithiasis has been identified in managed populations of bottlenose dolphins (Tursiops truncatus); most of these nephroliths are composed of 100% ammonium acid urate (AAU). Several therapies are being investigated to treat and prevent nephrolithiasis in dolphins including the alkalization of urine for dissolution of nephroliths. This study evaluates the solubility of AAU nephroliths in a phosphate buffer, pH range 6.0-8.0, and in a carbonate-bicarbonate buffer, pH range 9.0-10.8. AAU nephroliths were obtained from six dolphins and solubility studies were conducted using reverse-phase high performance liquid chromatography with ultraviolet detection at 290 nm. AAU nephroliths were much more soluble in a carbonate-bicarbonate buffer, pH range 9.0-10.8 compared to phosphate buffer pH range 6.0-8.0. In the pH range 6.0-8.0, the solubility was 45% lower in potassium phosphate buffer compared to sodium phosphate buffer. When citrate was used along with phosphate in the same pH range, the solubility was improved by 13%. At pH 7 and pH 8, 150 mM ionic strength buffer was optimum for dissolution. In summary, adjustment of urinary pH alone does not appear to be a useful way to treat AAU stones in bottlenose dolphins. Better understanding of the pathophysiology of AAU nephrolithiasis in dolphins is needed to optimize kidney stone prevention and treatment. PMID:24450043

Argade, Sulabha; Smith, Cynthia R; Shaw, Timothy; Zupkas, Paul; Schmitt, Todd L; Venn-Watson, Stephanie; Sur, Roger L

2013-12-01

26

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2011 CFR

...NH4 )2 CO3 , CAS Reg. No. 8000-73-5) is a mixture of ammonium bicarbonate (NH4 HCO3 ) and ammonium carbamate (NH2 COONH4 ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and...

2011-04-01

27

Chloride/bicarbonate exchange in human erythrocytes.  

PubMed

1. The exchange of chloride and bicarbonate across the human erythrocyte membrane has been followed by measuring the changes in extracellular pH which occur when chloride-rich erythrocytes are added to chloride-free media containing varying concentrations of bicarbonate and carbonic anhydrase. 2. The dependence of the rate of chloride/bicarbonate exchange on the extracellular concentration of bicarbonate was consistent with the existence of a saturable membrane anion transporter exhibiting Michaelis--Menten kinetics. In a medium containing sodium gluconate buffered to pH 7.0 with imidazole--malate the Km for bicarbonate activation of transport was 0.39 (+/- 0.03) mM and the Vmax was 2033 (+/- 80 m-mole anions exchanged/3 X 10(13) cells. min, at 10 degrees C. 3. Chloride/bicarbonate exchange was temperature-dependent with an Arrhenius activation energy of 19.4 kcal/mole in the temperature range 2--10 degrees C. 4. Exchange of intracellular chloride for extracellular bicarbonate was inhibited by the presence of extracellular halides. Inhibition by chloride, bromide and fluoride was competitive and the affinity of the transport system decreased in the order HCO-3 greater than Cl- greater than Br- greater than F-. The kinetics of inhibition by iodide were complex, but inhibitory effects of low concentrations of iodide were less than those of chloride and bromide. PMID:633149

Lambert, A; Lowe, A G

1978-02-01

28

Ammonium metabolism in humans.  

PubMed

Free ammonium ions are produced and consumed during cell metabolism. Glutamine synthetase utilizes free ammonium ions to produce glutamine in the cytosol whereas glutaminase and glutamate dehydrogenase generate free ammonium ions in the mitochondria from glutamine and glutamate, respectively. Ammonia and bicarbonate are condensed in the liver mitochondria to yield carbamoylphosphate initiating the urea cycle, the major mechanism of ammonium removal in humans. Healthy kidney produces ammonium which may be released into the systemic circulation or excreted into the urine depending predominantly on acid-base status, so that metabolic acidosis increases urinary ammonium excretion while metabolic alkalosis induces the opposite effect. Brain and skeletal muscle neither remove nor produce ammonium in normal conditions, but they are able to seize ammonium during hyperammonemia, releasing glutamine. Ammonia in gas phase has been detected in exhaled breath and skin, denoting that these organs may participate in nitrogen elimination. Ammonium homeostasis is profoundly altered in liver failure resulting in hyperammonemia due to the deficient ammonium clearance by the diseased liver and to the development of portal collateral circulation that diverts portal blood with high ammonium content to the systemic blood stream. Although blood ammonium concentration is usually elevated in liver disease, a substantial role of ammonium causing hepatic encephalopathy has not been demonstrated in human clinical studies. Hyperammonemia is also produced in urea cycle disorders and other situations leading to either defective ammonium removal or overproduction of ammonium that overcomes liver clearance capacity. Most diseases resulting in hyperammonemia and cerebral edema are preceded by hyperventilation and respiratory alkalosis of unclear origin that may be caused by the intracellular acidosis occurring in these conditions. PMID:22921946

Adeva, Maria M; Souto, Gema; Blanco, Natalia; Donapetry, Cristóbal

2012-11-01

29

Critical role of bicarbonate and bicarbonate transporters in cardiac function.  

PubMed

Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H(+), HCO3 (-) is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membranes. The functions of HCO3 (-) and HCO3 (-)-transporters in epithelial tissues have been studied extensively, but their functions in heart are less well understood. Here we review studies of the identities and physiological functions of Cl(-)/HCO3 (-) exchangers and Na(+)/HCO3 (-) cotransporters of the SLC4A and SLC26A families in heart. We also present RNA Seq analysis of their cardiac mRNA expression levels. These studies indicate that slc4a3 (AE3) is the major Cl(-)/HCO3 (-) exchanger and plays a protective role in heart failure, and that Slc4a4 (NBCe1) is the major Na(+)/HCO3 (-) cotransporter and affects action potential duration. In addition, previous studies show that HCO3 (-) has a positive inotropic effect in the perfused heart that is largely independent of effects on intracellular Ca(2+). The importance of HCO3 (-) in the regulation of contractility is supported by experiments showing that isolated cardiomyocytes exhibit sharply enhanced contractility, with no change in Ca(2+) transients, when switched from Hepes-buffered to HCO3 (-)- buffered solutions. These studies demonstrate that HCO3 (-) and HCO3 (-)-handling proteins play important roles in the regulation of cardiac function. PMID:25225601

Wang, Hong-Sheng; Chen, Yamei; Vairamani, Kanimozhi; Shull, Gary E

2014-08-26

30

Critical role of bicarbonate and bicarbonate transporters in cardiac function  

PubMed Central

Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H+, HCO3- is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membranes. The functions of HCO3- and HCO3--transporters in epithelial tissues have been studied extensively, but their functions in heart are less well understood. Here we review studies of the identities and physiological functions of Cl-/HCO3- exchangers and Na+/HCO3- cotransporters of the SLC4A and SLC26A families in heart. We also present RNA Seq analysis of their cardiac mRNA expression levels. These studies indicate that slc4a3 (AE3) is the major Cl-/HCO3- exchanger and plays a protective role in heart failure, and that Slc4a4 (NBCe1) is the major Na+/HCO3- cotransporter and affects action potential duration. In addition, previous studies show that HCO3- has a positive inotropic effect in the perfused heart that is largely independent of effects on intracellular Ca2+. The importance of HCO3- in the regulation of contractility is supported by experiments showing that isolated cardiomyocytes exhibit sharply enhanced contractility, with no change in Ca2+ transients, when switched from Hepes-buffered to HCO3-- buffered solutions. These studies demonstrate that HCO3- and HCO3--handling proteins play important roles in the regulation of cardiac function. PMID:25225601

Wang, Hong-Sheng; Chen, Yamei; Vairamani, Kanimozhi; Shull, Gary E

2014-01-01

31

Sodium Bicarbonate Therapy in Patients with Metabolic Acidosis  

PubMed Central

Metabolic acidosis occurs when a relative accumulation of plasma anions in excess of cations reduces plasma pH. Replacement of sodium bicarbonate to patients with sodium bicarbonate loss due to diarrhea or renal proximal tubular acidosis is useful, but there is no definite evidence that sodium bicarbonate administration to patients with acute metabolic acidosis, including diabetic ketoacidosis, lactic acidosis, septic shock, intraoperative metabolic acidosis, or cardiac arrest, is beneficial regarding clinical outcomes or mortality rate. Patients with advanced chronic kidney disease usually show metabolic acidosis due to increased unmeasured anions and hyperchloremia. It has been suggested that metabolic acidosis might have a negative impact on progression of kidney dysfunction and that sodium bicarbonate administration might attenuate this effect, but further evaluation is required to validate such a renoprotective strategy. Sodium bicarbonate is the predominant buffer used in dialysis fluids and patients on maintenance dialysis are subjected to a load of sodium bicarbonate during the sessions, suffering a transient metabolic alkalosis of variable severity. Side effects associated with sodium bicarbonate therapy include hypercapnia, hypokalemia, ionized hypocalcemia, and QTc interval prolongation. The potential impact of regular sodium bicarbonate therapy on worsening vascular calcifications in patients with chronic kidney disease has been insufficiently investigated. PMID:25405229

Adeva-Andany, María M.; Fernández-Fernández, Carlos; Mouriño-Bayolo, David; Castro-Quintela, Elvira; Domínguez-Montero, Alberto

2014-01-01

32

Sodium bicarbonate therapy in patients with metabolic acidosis.  

PubMed

Metabolic acidosis occurs when a relative accumulation of plasma anions in excess of cations reduces plasma pH. Replacement of sodium bicarbonate to patients with sodium bicarbonate loss due to diarrhea or renal proximal tubular acidosis is useful, but there is no definite evidence that sodium bicarbonate administration to patients with acute metabolic acidosis, including diabetic ketoacidosis, lactic acidosis, septic shock, intraoperative metabolic acidosis, or cardiac arrest, is beneficial regarding clinical outcomes or mortality rate. Patients with advanced chronic kidney disease usually show metabolic acidosis due to increased unmeasured anions and hyperchloremia. It has been suggested that metabolic acidosis might have a negative impact on progression of kidney dysfunction and that sodium bicarbonate administration might attenuate this effect, but further evaluation is required to validate such a renoprotective strategy. Sodium bicarbonate is the predominant buffer used in dialysis fluids and patients on maintenance dialysis are subjected to a load of sodium bicarbonate during the sessions, suffering a transient metabolic alkalosis of variable severity. Side effects associated with sodium bicarbonate therapy include hypercapnia, hypokalemia, ionized hypocalcemia, and QTc interval prolongation. The potential impact of regular sodium bicarbonate therapy on worsening vascular calcifications in patients with chronic kidney disease has been insufficiently investigated. PMID:25405229

Adeva-Andany, María M; Fernández-Fernández, Carlos; Mouriño-Bayolo, David; Castro-Quintela, Elvira; Domínguez-Montero, Alberto

2014-01-01

33

Addition of Sodium Bicarbonate to Rations of Pre and Postpartum Dairy Cows1  

Microsoft Academic Search

Sodium bicarbonate was added to complete mixed rations to evaluate the effect of buffer addition on adaptation to high-energy rations by dairy cows in early lactation. Forty-five Holstein cows were assigned to one of three treatment groups: control pre- and postpartum; control prepartum, buffer postpartum; and buffer pre- and postpartum. Rations consisted of 85% chopped grass hay: 15% concentrate prepartum

L. H. Kilmer; L. D. Muller; P. J. Wangsness

1980-01-01

34

Addition of Sodium Bicarbonate to Rations of Postpartum Dairy Cows: Physiological and Metabolic Effects1  

Microsoft Academic Search

Sodium bicarbonate was added to complete mixed rations to characterize physiological, metabolic, and ruminal changes immediately postpartum when dairy cows are switched abruptly from a low energy ration prepartum to a high energy ration postpartum. Twelve Holstein cows were paired and assigned randomly to either a control or buffered ration containing .8% sodium bicarbonate. Ra- tions consisted of 50% corn

L. H. Kilmer; L. D. Muller; T. J. Snyder

1981-01-01

35

Internal acid buffering in San Joaquin Valley fog drops and its influence on aerosol processing  

NASA Astrophysics Data System (ADS)

Although several chemical pathways exist for S(IV) oxidation in fogs and clouds, many are self-limiting: as sulfuric acid is produced and the drop pH declines, the rates of these pathways also decline. Some of the acid that is produced can be buffered by uptake of gaseous ammonia. Additional internal buffering can result from protonation of weak and strong bases present in solution. Acid titrations of high pH fog samples (median pH=6.49) collected in California's San Joaquin Valley reveal the presence of considerable internal acid buffering. In samples collected at a rural location, the observed internal buffering could be nearly accounted for based on concentrations of ammonia and bicarbonate present in solution. In samples collected in the cities of Fresno and Bakersfield, however, significant additional, unexplained buffering was present over a pH range extending from approximately four to seven. The additional buffering was found to be associated with dissolved compounds in the fogwater. It could not be accounted for by measured concentrations of low molecular weight ( C1- C3) carboxylic acids, S(IV), phosphate, or nitrophenols. The amount of unexplained buffering in individual fog samples was found to correlate strongly with the sum of sample acetate and formate concentrations, suggesting that unmeasured organic species may be important contributors. Simulation of a Bakersfield fog episode with and without the additional, unexplained buffering revealed a significant impact on the fog chemistry. When the additional buffering was included, the simulated fog pH remained 0.3-0.7 pH units higher and the amount of sulfate present after the fog evaporated was increased by 50%. Including the additional buffering in the model simulation did not affect fogwater nitrate concentrations and was found to slightly decrease ammonium concentrations. The magnitude of the buffering effect on aqueous sulfate production is sensitive to the amount of ozone present to oxidize S(IV) in these high pH fogs.

Collett, Jeffrey L.; Hoag, Katherine J.; Rao, Xin; Pandis, Spyros N.

36

Effect of bicarbonate on iron-mediated oxidation of low-density lipoprotein  

NASA Astrophysics Data System (ADS)

Oxidation of low-density lipoprotein (LDL) may play an important role in atherosclerosis. We studied the effects of bicarbonate/CO2 and phosphate buffer systems on metal ion-catalyzed oxidation of LDL to malondialdehyde (MDA) and to protein carbonyl and MetO derivatives. Our results revealed that LDL oxidation in mixtures containing free iron or heme derivatives was much greater in bicarbonate/CO2 compared with phosphate buffer. However, when copper was substituted for iron in these mixtures, the rate of LDL oxidation in both buffers was similar. Iron-catalyzed oxidation of LDL was highly sensitive to inhibition by phosphate. Presence of 0.3-0.5 mM phosphate, characteristic of human serum, led to 30-40% inhibition of LDL oxidation in bicarbonate/CO2 buffer. Iron-catalyzed oxidation of LDL to MDA in phosphate buffer was inhibited by increasing concentrations of albumin (10-200 ?M), whereas MDA formation in bicarbonate/CO2 buffer was stimulated by 10-50 ?M albumin but inhibited by higher concentrations. However, albumin stimulated the oxidation of LDL proteins to carbonyl derivatives at all concentrations examined in both buffers. Conversion of LDL to MDA in bicarbonate/CO2 buffer was greatly stimulated by ADP, ATP, and EDTA but only when EDTA was added at a concentration equal to that of iron. At higher than stoichiometric concentrations, EDTA prevented oxidation of LDL. Results of these studies suggest that interactions between bicarbonate and iron or heme derivatives leads to complexes with redox potentials that favor the generation of reactive oxygen species and/or to the generation of highly reactive CO2 anion or bicarbonate radical that facilitates LDL oxidation. Freely available online through the PNAS open access option.Abbreviations: LDL, low-density lipoprotein; MDA, malondialdehyde; MetO, methionine sulfoxide.

Arai, Hirofumi; Berlett, Barbara S.; Chock, P. Boon; Stadtman, Earl R.

2005-07-01

37

Renal Bicarbonate Reabsorption and Hydrogen Ion Excretion in Normal Infants*  

PubMed Central

After acute administration of ammonium chloride, infants 1 to 16 months of age were similar to older children in their capacity to acidify their urine. The infants had a higher rate of excretion of titratable acid and a lower rate of excretion of ammonium but were similar in their rate of excretion of total hydrogen ion. Bicarbonate titrations performed in infants during the first year of life demonstrated a threshold ranging from 21.5 to 22.5 mmoles per L, maximal rate of reabsorption from 2.6 to 2.9 mmoles per 100 ml glomerular filtrate, and marked titration splay. A nephronic frequency distribution curve of the ratio of glomerular filtration rate to tubular reabsorptive capacity demonstrated both heterogeneity and skewing to the right, suggesting the presence of significant numbers of nephrons with low tubular transport capacity relative to filtration rate. It is suggested that the “physiologic acidosis” of the infant is due neither to a limited renal capacity to excrete hydrogen ion nor to a reduced capacity for reabsorption of bicarbonate, but rather to a low renal plasma bicarbonate threshold. Although the level of the threshold may relate to the kinetics of bicarbonate reabsorption during this period, it appears to be due at least in part to functional and morphologic heterogeneity of nephrons. PMID:16695919

Edelmann, Chester M.; Soriano, Juan Rodriguez; Boichis, Hayim; Gruskin, Alan B.; Acosta, Melinda I.

1967-01-01

38

[Comparison of different buffer systems for separation of 15 nucleosides by capillary electrophoresis].  

PubMed

The most suitable background electrolytes (BGEs) for simultaneous separation of 15 nucleosides by different modes of capillary electrophoresis (CE) were obtained. Various modes of CE were performed including capillary zone electrophoresis (CZE), capillary electrophoresis-electrospray ionization-time of flight mass spectrometry (CE-ESI-TOF/MS) and micellar electrokinetic chromatography (MEKC). The electrolyte buffers using sodium tetraborate decahydrate, disodium hydrogen phosphate, sodium acetate, sodium bicarbonate, ammonium acetate or 1, 2-diamino-ethane (DEA) were tested, and the best of them were systematically optimized. In CZE mode, the nucleosides could not be separated completely with sodium tetraborate decahydrate or disodium hydrogen phosphate as BGEs, demonstrating the limited applicability of the two buffer systems for complex samples. However, with 300 mmol/L DEA (containing 2% acetone) as BGE, 15 nucleosides could be separated with good resolution and peak shape, which proved that the DEA buffer was most suitable in CZE. The best buffer system in MEKC mode was 25 mmol/L disodium hydrogen phosphate with 70 mmol/L sodium dodecyl sulfate (SDS), and it was successfully applied for the separation of the nucleosides in Chinese Anthopleura lanthogrammica Berkly. The optimum buffer system for CE-ESI-TOF/MS analysis was 20 mmol/L ammonium acetate (pH 10.0). In the positive ion mode, the MS signals of each compound were better than those in the literature using DEA as BGE. The results of this study demonstrated the applicability of different buffer systems for the simultaneous separation of 15 nucleosides, and were helpful for the development of CE method in complex sample separation. PMID:22032157

Shi, Qian; Chen, Junhui; Li, Xin; Cao, Wei; Zheng, Li; Zang, Jiaye; Wang, Xiaoru

2011-06-01

39

21 CFR 582.1736 - Sodium bicarbonate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Sodium bicarbonate. 582.1736 Section 582.1736 Food...Purpose Food Additives § 582.1736 Sodium bicarbonate. (a) Product. Sodium bicarbonate. (b) Conditions of use. This...

2010-04-01

40

21 CFR 582.1613 - Potassium bicarbonate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food...Food Additives § 582.1613 Potassium bicarbonate. (a) Product. Potassium bicarbonate. (b) Conditions of use. This...

2010-04-01

41

Characterization of bicarbonate-dependent potassium uptake in cultured corneal endothelial cells  

SciTech Connect

Bovine corneal endothelial (BCE) cells in culture demonstrated 86Rb+ uptake which was mostly ouabain-sensitive with some (15 to 50%) ouabain-insensitive uptake that was dependent on the presence of bicarbonate in the incubation medium. Bovine smooth muscle (SM) cells demonstrated ouabain-sensitive 86Rb+ uptake but the ouabain-insensitive 86Rb+ uptake was not bicarbonate-dependent. Although omission of bicarbonate from the incubation buffer resulted in some reduction in the pH, this change was not responsible for the reduction in the ouabain-insensitive 86Rb+ uptake. Furthermore, the removal of bicarbonate decreased the 86Rb+ influx but not its efflux. This ouabain-insensitive and bicarbonate-dependent 86Rb+ influx in BCE cells proceeded at a linear rate for at least 60 min and increased as a function of bicarbonate concentration such that almost maximal uptake was observed at a concentration of about 10 to 15 mM. Saturation of the bicarbonate-dependent 86Rb+ pump in BCE cells occurred at a concentration of 2 mM Rb+ in the incubation buffer, similar to the previously observed value for the Na+, K+-ATPase. Competition experiments with both unlabeled Rb+ and K+ demonstrated that likewise in the Na+, K+-ATPase the 86Rb+ influx represented physiological influx of K+. Furthermore, the energy requirements of the bicarbonate-dependent 86Rb+ uptake were similar to those of the 86Rb+ uptake via the Na+, K+-ATPase. The results described in this work demonstrated a novel bicarbonate-dependent K+ pump in addition to the Na+, K+-ATPase pump.(ABSTRACT TRUNCATED AT 250 WORDS)

Savion, N.; Farzame, N.; Berlin, H.B.

1989-04-01

42

Phosphate Dialytic Removal: Enhancement of Phosphate Cellular Clearance by Biofiltration (with Acetate-Free Buffer Dialysate)  

Microsoft Academic Search

Phosphate dialytic removal (PDR) depends in part on the type (acetate or bicarbonate) and the concentration of the buffer dialysate. Plasma phosphate reduction or PDR during a dialysis treatment is the algebraic sum, of phosphate cellular flux (removal or captation) and of phosphate tissular precipitation. High bicarbonate levels induce an intracellular shift of phosphate, thus not available for dialytic removal.

M. Fischbach; G. Hamel; U. Simeoni; J. Geisert

1992-01-01

43

Effect of Dietary Sodium Bicarbonate and Magnesium Oxide on Production and Physiology in Early Lactation1  

Microsoft Academic Search

Twenty cows were in an experiment to measure effects of dietary buffers, sodium bicarbonate and magnesium oxide, on ration adjustment and incidence of metabolic problems in the first 8 wk postpartum. Cows were fed 2.7 kg grain per day and alfalfa ad libitum prepartum and switched immediately to a complete ration of 40% corn silage and 60% con- centrate (dry

R. A. Erdman; R. L. Botts; R. W. Hemken; L. S. Bull

1980-01-01

44

Ammonium Acetate and Ammonium Bicarbonate in Traps for Anastrepha Fruit Flies  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fruit flies in the genus Anastrepha, especially the reproductive age females, are attracted to protein baits. Synthetic lures based on the principal components of protein degradation, especially ammonia along with acetic acid, were tested against three of the most economically important Anastrepha s...

45

77 FR 50613 - Didecyl Dimethyl Ammonium Carbonate and Didecyl Dimethyl Ammonium Bicarbonate; Exemption From the...  

Federal Register 2010, 2011, 2012, 2013

...jointly referred to as DDACB on food contact surfaces when applied or used in public...requirement of tolerance residues resulting from contact with surfaces treated with solutions where...gov/dockets. FOR FURTHER INFORMATION CONTACT: Velma Noble, Antimicrobials...

2012-08-22

46

Bicarbonate Modulates Oxidative and Functional Damage in Ischemia-Reperfusion  

PubMed Central

The carbon dioxide/bicarbonate (CO2/HCO3?) pair is the main biological pH buffer. However, its influence on biological processes, and in particular redox processes, is still poorly explored. Here we study the effect of CO2/HCO3? on ischemic injury in three distinct models (cardiac HL-1 cells, perfused rat heart and C. elegans). We found that, while different concentrations of CO2/HCO3? do not affect function under basal conditions, ischemia-reperfusion or similar insults in the presence of higher CO2/HCO3? resulted in greater functional loss associated with higher oxidative damage in all models. Since the effect of CO2/HCO3? was observed in all models tested, we believe this buffer is an important determinant of oxidative damage following ischemia-reperfusion. PMID:23195687

Queliconi, Bruno B.; Marazzi, Thire B. M.; Vaz, Sandra M.; Brookes, Paul S.; Nehrke, Keith; Augusto, Ohara; Kowaltowski, Alicia J.

2014-01-01

47

Bicarbonate modulates oxidative and functional damage in ischemia-reperfusion.  

PubMed

The carbon dioxide/bicarbonate (CO(2)/HCO(3)(-)) pair is the main biological pH buffer. However, its influence on biological processes, and in particular redox processes, is still poorly explored. Here we study the effect of CO(2)/HCO(3)(-) on ischemic injury in three distinct models (cardiac HL-1 cells, perfused rat heart, and Caenorhabditis elegans). We found that, although various concentrations of CO(2)/HCO(3)(-) do not affect function under basal conditions, ischemia-reperfusion or similar insults in the presence of higher CO(2)/HCO(3)(-) resulted in greater functional loss associated with higher oxidative damage in all models. Because the effect of CO(2)/HCO(3)(-) was observed in all models tested, we believe this buffer is an important determinant of oxidative damage after ischemia-reperfusion. PMID:23195687

Queliconi, Bruno B; Marazzi, Thire B M; Vaz, Sandra M; Brookes, Paul S; Nehrke, Keith; Augusto, Ohara; Kowaltowski, Alicia J

2013-02-01

48

The electrogenic sodium bicarbonate cotransporter NBCe1 is a high-affinity bicarbonate carrier in cortical astrocytes.  

PubMed

The electrogenic sodium bicarbonate cotransporter NBCe1 (SLC4A4) is a robust regulator of intracellular H(+) and a significant base carrier in many cell types. Using wild-type (WT) and NBCe1-deficient (NBC-KO) mice, we have studied the role of NBCe1 in cortical astrocytes in culture and in situ by monitoring intracellular H(+) using the H(+)-sensitive dye BCECF [2',7'-bis-(carboxyethyl)-5-(and-6)-carboxyfluorescein] in wide-field and confocal microscopy. Adding 0.1-3 mm HCO3(-) to an O2-gassed, HEPES-buffered saline solution lowered the intracellular H(+) concentration with a Km of 0.65 mm HCO3(-) in WT astrocytes, but slowly raised [H(+)]i in NBCe1-KO astrocytes. Human NBCe1 heterologously expressed in Xenopus oocytes could be activated by adding 1-3 mm HCO3(-), and even by residual HCO3(-) in a nominally CO2/HCO3(-)-free saline solution. Our results demonstrate a surprisingly high apparent bicarbonate sensitivity mediated by NBCe1 in cortical astrocytes, suggesting that NBCe1 may operate over a wide bicarbonate concentration in these cells. PMID:24453308

Theparambil, Shefeeq M; Ruminot, Iván; Schneider, Hans-Peter; Shull, Gary E; Deitmer, Joachim W

2014-01-22

49

Sodium bicarbonate?DTPA test for macro?and micronutrient elements in soils  

Microsoft Academic Search

Individual soil tests are used to assess plant nutrient element needs. Separate soil tests, however, are time consuming and costly. Our objective was to develop a 0.5M sodium bicarbonate (NaHCO3) soil phosphorus (P) test in combination with 0.005M diethylenetriaminepentaacetic acid (DTPA) so macronutrient dements: ammonium?nitrogen (NH4?N), nitrate?nitrogen (NO3?N), P, potassium (K), calcium (Ca), and magnesium (Mg); and micronutrients: iron (Fe),

J. B. Rodriguez; J. R. Self; G. A. Peterson; D. G. Westfall

1999-01-01

50

Bicarbonate and bicarbonate\\/lactate peritoneal dialysis solutions for the treatment of infusion pain  

Microsoft Academic Search

Bicarbonate and bicarbonate\\/lactate peritoneal dialysis solutions for the treatment of infusion pain. A randomized, double-blind, cross-over study was undertaken to determine the effects of novel bicarbonate (38 mM) and bicarbonate (25 mM)\\/lactate (15 mM) containing peritoneal dialysis (PD) solutions on infusion pain in patients who experienced inflow pain with conventional lactate (40 mM) solution. Pain was assessed using a verbal

Robert A. Mactier; Timothy S. Sprosen; Ram Gokal; Paul F. Williams; Marianne Lindbergh; Ramesh B. Naik; Ulf Wrege; Knut-Christian Gröntoft; Rutger Larsson; Jonas Berglund; Anders P. Tranaeus; Dirk Faict

1998-01-01

51

Buffer Biology.  

ERIC Educational Resources Information Center

Presents a science experiment in which students test the buffering capacity of household products such as shampoo, hand lotion, fizzies candy, and cola. Lists the standards addressed in this experiment and gives an example of a student lab write-up. (YDS)

Morgan, Kelly

2000-01-01

52

New reinfusate composition in high UF haemodiafiltration: electrolyte solution combined with bicarbonate.  

PubMed

When high-permeability membranes are employed, high UF should be used in order to obtain optimal uraemic toxin removal and to avoid backfiltration. A high UF requires the infusion of an electrolyte solution including Ca2+ and Mg2+ which cannot be associated with bicarbonate in prepackaged solutions because of the risk of precipitation; therefore acetate or lactate are used as buffers. This study evaluated whether bicarbonate can be infused together with an electrolyte solution in high UF HDF, and if so, the clinical advantages that could be obtained by substituting acetate with bicarbonate in the reinfusate. In 12 patients on postdilutional high UF (121 +/- 10 ml/min) HDF (Qb 400, Qd 500 ml/min, dialysate containing Na, 141 +/- 2; K, 2.5; Ca, 3.5; Mg, 0.7; Cl, 111 +/- 2; acetate, 3; bicarbonate, 34 mEq/l; TMP 400 mmHg), an acid bag (Na, 128; K, 4; Ca, 7; Mg, 2; Cl, 141; acetate, 8 mEq/l), and a basic bag (Na, 150; HCO3, 80; Cl, 70 mEq/l), each containing 2 litres, were simultaneously infused through a Y connection. The final composition of reinfusate at the drip-chamber, combined with the above dialysate, allowed a negative intradialytic mass balance for Na, K, Mg and a positive one for Ca, acetate, to maintain prepostdialytic plasma values of these ions as well as bicarbonate close to normal limits. Furthermore, in five high-risk patients, clinical data were evaluated on high UF HDF, infusing a solution containing either acetate or bicarbonate, and an improvement of vascular stability was observed with the bicarbonate reinfusate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8381936

Gonella, M; Calabrese, G; Pratesi, G; Baldin, C; Mazzotta, A; Vagelli, G

1993-01-01

53

Effect of ranitidine on basal and bicarbonate enhanced intragastric PCO2: a tonometric study  

Microsoft Academic Search

A high intragastric PCO2 (iPCO2), determined tonometrically, is the main factor participating in a low gastric intramucosal pH (pHi) and may point to gastric mucosal ischaemia. iPCO2 might also increase, however, after buffering of gastric acid by bicarbonate; the magnitude of this effect and the efficacy of H2 blockers to prevent it are unclear. Ten healthy volunteers (20-24 years) were

J J Kolkman; A B Groeneveld; S G Meuwissen

1994-01-01

54

Buffer Index and Buffer Capacity for a Simple Buffer Solution  

NASA Astrophysics Data System (ADS)

Many papers that present the buffering effect of the simple buffer solution consider the notion of buffer index and buffer capacity as being equivalent. Moreover, IUPAC defies them as the same thing. According to the definition of the authors who have introduced these two units, the paper shows that there is a large difference between them. The buffer index can be defined as the differential ratio of the increase in the amount of strong acid or strong base added, to pH variation. The buffer capacity is numerically expressed to be equal with the minimum concentration of strong acid or strong base which causes the variation of buffer's pH with one unit. The field of application of both notions is different: the buffer capacity is used in the quantitative chemical analysis and the buffer index in studying biological systems.

Chiriac, Veronica; Balea, Gabriel

1997-08-01

55

CELL BIOLOGY: A Universal Bicarbonate Sensor  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. The three principal molecular events that prepare sperm for fertilization are all controlled by the intracellular nucleotide adenosine 3',5'-monophosphate (cAMP). One of these, capacitation, is also regulated by bicarbonate ions. The elusive connection between cAMP and bicarbonate ions now appears to be solved as Kaupp and Weyand explain in their Perspective. Bicarbonate ions enter sperm through the anion transporter in the sperm plasma membrane and activate the soluble form of adenylyl cyclase, the enzyme that synthesizes cAMP (Chen et al.)

U. Benjamin Kaupp (Institut für Biologische Informationsverarbeitung;); Ingo Weyand (Institut für Biologische Informationsverarbeitung;)

2000-07-28

56

Kinetic buffers.  

PubMed

This paper proposes a new type of molecular device that is able to act as an inverse proton sponge to slowly decrease the pH inside a reaction vessel. This makes the automatic monitoring of the concentration of pH-sensitive systems possible. The device is a composite formed of an alkyl chloride, which kinetically produces acidity, and a buffer that thermodynamically modulates the variation in pH value. Profiles of pH versus time (pH-t plots) have been generated under various experimental conditions by computer simulation, and the device has been tested by carrying out automatic spectrophotometric titrations, without using an autoburette. To underline the wide variety of possible applications, this new system has been used to realize and monitor HCl uptake by a di-copper(II) bistren complex in a single run, in a completely automatic experiment. PMID:25387452

Alibrandi, Giuseppe; Fabbrizzi, Luigi; Licchelli, Maurizio; Puglisi, Antonio

2015-01-12

57

Vitamin C (ascorbic acid) induced hydroxyl radical formation in copper contaminated household drinking water: role of bicarbonate concentration.  

PubMed

We have previously shown that Vitamin C (ascorbic acid) can trigger hydroxyl radical formation in copper contaminated household drinking water. We report here that the capacity of ascorbic acid to catalyze hydroxyl radical generation in the drinking water samples is strongly dependent on the bicarbonate concentration (buffer capacity and pH) of the samples. We found that at least 50 mg/l bicarbonate was required in the water samples to maintain the pH over 5.0 after ascorbic acid addition. At this pH, that is higher than the pKa1 4.25 of ascorbic acid, a hydroxyl radical generating redox cycling reaction involving the mono-anion of vitamin C and copper could take place. The ascorbic acid induced hydroxyl radical generating reaction could easily be mimicked in Milli-Q water by supplementing the water with copper and bicarbonate. Our results demonstrate that ascorbic acid can induce a pH dependent hydroxyl radical generating reaction in copper contaminated household tap water that is buffered with bicarbonate. The impact of consuming ascorbic acid together with copper and bicarbonate containing drinking water on human health is discussed. PMID:14567450

Jansson, Patric J; Asplund, Klara U M; Mäkelä, Johanna C; Lindqvist, Christer; Nordström, Tommy

2003-08-01

58

Bicarbonate utilization by leaf protoplasts from Potamogeton  

SciTech Connect

Leaves from the submerged angiosperm P. lucens are able to assimilate bicarbonate. These leaves behave polarly: during bicarbonate utilization protons (H/sup +/) are excreted by the cells of the lower epidermis, while hydroxyl (OH/sup -/) ions are excreted by the upper epidermal cells. It has been proposed that acidification of the apoplast is a prerequisite for bicarbonate utilization. To test this hypothesis /sup 14/C fixation by protoplasts was determined at different pH values. Also experiments, using the isotopic disequilibrium technique were performed. They showed that at pH values > 8, bicarbonate is a major carbon source for photosynthesis in protoplasts, despite the absence of cell walls and polarity. At pH values around 6, the rate of /sup 14/C-fixation in protoplasts equals that of intact leaves. At pH values > 8, however, intact leaves show a higher rate. From this, and other experiments, the authors conclude that at least 2 processes contribute to bicarbonate utilization in P. lucens leaves: active transport (H/sup +/-HCO/sub 3//sup -/ symport.) and acidification of the apoplast resulting in the conversion of bicarbonate into CO/sub 2/. Polarity may increase the efficiency of both.

Staal, M.; Elzenga, J.T.M.; Prins, H.B.A.

1987-04-01

59

Cation-coupled bicarbonate transporters.  

PubMed

Cation-coupled HCO3(-) transport was initially identified in the mid-1970s when pioneering studies showed that acid extrusion from cells is stimulated by CO2/HCO3(-) and associated with Na(+) and Cl(-) movement. The first Na(+)-coupled bicarbonate transporter (NCBT) was expression-cloned in the late 1990s. There are currently five mammalian NCBTs in the SLC4-family: the electrogenic Na,HCO3-cotransporters NBCe1 and NBCe2 (SLC4A4 and SLC4A5 gene products); the electroneutral Na,HCO3-cotransporter NBCn1 (SLC4A7 gene product); the Na(+)-driven Cl,HCO3-exchanger NDCBE (SLC4A8 gene product); and NBCn2/NCBE (SLC4A10 gene product), which has been characterized as an electroneutral Na,HCO3-cotransporter or a Na(+)-driven Cl,HCO3-exchanger. Despite the similarity in amino acid sequence and predicted structure among the NCBTs of the SLC4-family, they exhibit distinct differences in ion dependency, transport function, pharmacological properties, and interactions with other proteins. In epithelia, NCBTs are involved in transcellular movement of acid-base equivalents and intracellular pH control. In nonepithelial tissues, NCBTs contribute to intracellular pH regulation; and hence, they are crucial for diverse tissue functions including neuronal discharge, sensory neuron development, performance of the heart, and vascular tone regulation. The function and expression levels of the NCBTs are generally sensitive to intracellular and systemic pH. Animal models have revealed pathophysiological roles of the transporters in disease states including metabolic acidosis, hypertension, visual defects, and epileptic seizures. Studies are being conducted to understand the physiological consequences of genetic polymorphisms in the SLC4-members, which are associated with cancer, hypertension, and drug addiction. Here, we describe the current knowledge regarding the function, structure, and regulation of the mammalian cation-coupled HCO3(-) transporters of the SLC4-family. PMID:25428855

Aalkjaer, Christian; Boedtkjer, Ebbe; Choi, Inyeong; Lee, Soojung

2014-10-01

60

REMOTE Shared Memory Buffer #2  

E-print Network

;#12;#12;Command Buffer Buffer Status Command Buffer Buffer Status Buffer StatusCommand Buffer Process RCS Process RCS Process RCS Write status messages Read command messages Module 1 Module 3 W rite com m and m

61

Predicting the safety and efficacy of buffer therapy to raise tumour pHe: an integrative modelling study  

E-print Network

the microenvironment of tumours have demonstrated a consistently low extracellular pH (pHe) ­ typically in the range demonstrated the vast majority of human cancers exhibit significantly increased glucose metabolism when of blood and tumour buffering to examine the impact of oral administration of bicarbonate buffer in mice

Maini, Philip K.

62

40 CFR 415.140 - Applicability; description of the sodium bicarbonate production subcategory.  

Code of Federal Regulations, 2011 CFR

...Applicability; description of the sodium bicarbonate production subcategory. ...MANUFACTURING POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory ...Applicability; description of the sodium bicarbonate production...

2011-07-01

63

40 CFR 415.140 - Applicability; description of the sodium bicarbonate production subcategory.  

Code of Federal Regulations, 2012 CFR

...Applicability; description of the sodium bicarbonate production subcategory. ...MANUFACTURING POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory ...Applicability; description of the sodium bicarbonate production...

2012-07-01

64

40 CFR 415.140 - Applicability; description of the sodium bicarbonate production subcategory.  

...Applicability; description of the sodium bicarbonate production subcategory. ...MANUFACTURING POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory ...Applicability; description of the sodium bicarbonate production...

2014-07-01

65

40 CFR 415.140 - Applicability; description of the sodium bicarbonate production subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the sodium bicarbonate production subcategory. ...MANUFACTURING POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory ...Applicability; description of the sodium bicarbonate production...

2013-07-01

66

Sodium bicarbonate in chemical flooding: Part 1: Topical report. [Sodium bicarbonate and sodium carbonate  

SciTech Connect

To compare oil recovery and alkali consumption in alkaline flooding using sodium bicarbonate with other alkaline agents, coreflooding experiments were performed in turn with viscosified sodium bicarbonate and viscosified sodium carbonate solutions. Oil recovery was monitored, and the effluent brine from these corefloods was analyzed for silicon, aluminum, pH, and total inorganic carbon. The results indicate that viscosified sodium bicarbonate recovered more of the asphaltic Cerro-Negro crude than of the less asphaltic Wilmington crude oil. The recovery efficiency using the viscosified sodium carbonate was similar for the two crudes. For both crudes, the percent oil recovery using viscosified sodium carbonate was slightly higher than that using the viscosified sodium bicarbonate. Mineral dissolution and decrease in pH were found to be greater in corefloods using viscosified sodium carbonate. Total inorganic carbon recovery can be obtained in corefloods with either agent, provided that a sufficient water drive follows the chemical slug. Long-term experiments were performed by recirculating alkaline solutions through oil-free, unfired Berea sandstone to monitor the rock/alkali interactions. The experimental results indicate an eight-fold decrease in quartz dissolution by sodium bicarbonate compared with sodium carbonate. Moderate magnesium solubility was observed at the pH of the bicarbonate solution. Low solubility of magnesium and aluminum at the pH of the carbonate indicates the possible formation of precipitates. In these experiments 13% of the carbonate was converted to bicarbonate. Total alkalinity was not significantly decreased with either agent. 18 refs., 5 tabs.

Peru, D.A.; Lorenz, P.B.

1987-07-01

67

Synchronous Optical Packet Buffers  

Microsoft Academic Search

Synchronous optical packet buffering is presented as a solution for asynchronous time division multiplexed (TDM) optical packet switched networks. Truly asynchronous optical packet synchronization and buffering are demonstrated using multiple independent transmitters, synchronous optical buffers, and a burst mode receiver. Optical packet synchronizers are used to dynamically align incoming asynchronous packets to local timeslots for synchronous loading of buffers. Multiple

John P. Mack; Emily F. Burmeister; John M. Garcia; Henrik N. Poulsen; Biljana Stamenic; Geza Kurczveil; Kimchau N. Nguyen; Kurtis Hollar; John E. Bowers; Daniel J. Blumenthal

2010-01-01

68

Does metallic ammonium exist  

NASA Technical Reports Server (NTRS)

A description is given of calculations which demonstrate that metallic ammonium, at least in the form envisaged by Ramsey (1951), is unstable at all pressures. On the basis of the computational results it is concluded that monovalent metallic ammonium is never the thermodynamically favored phase for an NH3-1/2H2 mixture.

Stevenson, D. J.

1975-01-01

69

EFFECT OF MS-222 CONCENTRATION WITH AND WITHOUT BUFFERING ON THE STRESS RESPONSE OF CHANNEL CATFISH  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effect of the anesthetic methane tricainesulfonate (MS-222) (buffered with sodium bicarbonate and unbuffered) was evaluated on anesthetization efficacy and stress responses of juvenile channel catfish (18.4±2.1 g). Fish were exposed to MS-222 at 0, 90, 120, or 180 mg/L for 10 min after reaching ...

70

Seawater bicarbonate removal during hydrothermal circulation  

NASA Astrophysics Data System (ADS)

High temperature fluids sampled at hydrothermal vents represent a complex alteration product of water-rock reactions on a multi-component mixture of source fluids. Sources to high-temperature hydrothermal samples include the 'original' seawater present in the recharge limb of circulation, magmatically influenced fluids added at depth as well as any seawater entrained during sampling. High-temperature hydrothermal fluids are typically enriched in magmatic volatiles, with CO2 the dominant species, characterized by concentrations of 10's-100's of mmol/kg (1, 2). Typically, the high concentration of CO2 relative to background seawater bicarbonate concentrations (~2.3 mmol/kg) obscures a full analysis of the fate of seawater bicarbonate during high-temperature hydrothermal circulation. Here we present data from a suite of samples collected over the past 15 years from high-temperature hydrothermal vents at 9N, Endeavour, Lau Basin, and the MAR that have endmember CO2 concentrations less than 10 mmol/kg. Using stable and radiocarbon isotope measurements these samples provide a unique opportunity to examine the balance between 'original' seawater bicarbonate and CO2 added from magmatic sources. Multiple lines of evidence from multiple hydrothermal settings consistently points to the removal of ~80% of the 'original' 2.3 mmol/kg seawater bicarbonate. Assuming that this removal occurs in the low-temperature, 'recharge' limb of hydrothermal circulation, this removal process is widely occurring and has important contributions to the global carbon cycle over geologic time. 1. Lilley MD, Butterfield DA, Lupton JE, & Olson EJ (2003) Magmatic events can produce rapid changes in hydrothermal vent chemistry. Nature 422(6934):878-881. 2. Seewald J, Cruse A, & Saccocia P (2003) Aqueous volatiles in hydrothermal fluids from the Main Endeavour Field, northern Juan de Fuca Ridge: temporal variability following earthquake activity. Earth and Planetary Science Letters 216(4):575-590.

Proskurowski, G. K.; Seewald, J.; Sylva, S. P.; Reeves, E.; Lilley, M. D.

2013-12-01

71

Sodium Is Not Required for Chloride Efflux via Chloride/Bicarbonate Exchanger from Rat Thymic Lymphocytes  

PubMed Central

Sodium-dependent Cl?/HCO3? exchanger acts as a chloride (Cl?) efflux in lymphocytes. Its functional characterization had been described when Cl? efflux was measured upon substituting extracellular sodium (Na+) by N-methyl-D-glucamine (NMDG). For Na+ and Cl? substitution, we have used D-mannitol or NMDG. Thymocytes of male Wistar rats aged 7–9 weeks were used and intracellular Cl? was measured by spectrofluorimetry using MQAE dye in bicarbonate buffers. Chloride efflux was measured in a Cl?-free buffer (Cl? substituted with isethionate acid) and in Na+ and Cl?-free buffer with D-mannitol or with NMDG. The data have shown that Cl? efflux is mediated in the absence of Na+ in a solution containing D-mannitol and is inhibited by H2DIDS. Mathematical modelling has shown that Cl? efflux mathematical model parameters (relative membrane permeability, relative rate of exchanger transition, and exchanger efficacy) were the same in control and in the medium in which Na+ had been substituted by D-mannitol. The net Cl? efflux was completely blocked in the NMDG buffer. The same blockage of Cl? efflux was caused by H2DIDS. The study results allow concluding that Na+ is not required for Cl? efflux via Cl?/HCO3? exchanger. NMDG in buffers cannot be used for substituting Na+ because NMDG inhibits the exchanger. PMID:25003116

Stakišaitis, Donatas; Meilus, Vaidevutis; Juška, Alfonsas; Matusevi?ius, Paulius; Didžiapetrien?, Janina

2014-01-01

72

EFFECT OF BUFFERED AND UNBUFFERED TRICAINE METHANESULFONATE (MS-222) AT DIFFERENT CONCENTRATIONS ON THE STRESS RESPONSES OF CHANNEL CATFISH (ICTALURUS PUNCTATUS RAFINESQUE)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effects of four concentrations (0, 90, 120, and 180 mg/L) of the anesthetic tricaine methanesulfonate (MS-222) (buffered and unbuffered with sodium bicarbonate) were evaluated on anesthetization efficacy and stress responses of juvenile channel catfish (Ictalurus punctatus Rafinesque). Buffered ...

73

Enhancement of the absorption of CO{sub 2} in alkaline buffer solutions: Joint action of two enhancers  

SciTech Connect

The authors measured the absorption of CO{sub 2} in alkaline 0.5 M/0.5 M sodium carbonate/bicarbonate buffers containing either saccharose and sodium arsenite or saccharose and formaldehyde. Absorption enhancement increased upon increasing the concentration of either of the catalysts, but the joint action of the two was always less than the sum of their individual effects, the difference being a function of the acidities and concentrations of the catalysts and the pH of the carbonate/bicarbonate buffer solution

Vazquez, G.; Chenlo, F.; Pereira, G.; Vazquez, P. [Univ. of Santiago de Compostela (Spain). Dept. of Chemical Engineering] [Univ. of Santiago de Compostela (Spain). Dept. of Chemical Engineering

1999-05-01

74

Ammonium sulfide organosolv pulping  

Microsoft Academic Search

The use of ammonium sulfide in aqueous ethanol and methanol was investigated for pulping of wood. Hemlock chips required 21% ammonium sulfide (equivalent to 19% Na2O) at 180°C to become delignified to the kappa range 35–50. The yields exceeded those of conventional kraft pulps by 14% on dry wood basis. Over 75% of the original glucomannan was recovered in the

V. L. Chiang; K. V. Sarkanen

1983-01-01

75

[Biofiltration without buffering substances in the dialysate].  

PubMed

A new hemodiafiltration technique, acetate free biofiltration (AFB), has been recently introduced in the treatment of chronic uremia. It is performed with a buffer free dialysate and a simultaneous infusion in post-dilution mode of a sodium bicarbonate solution (concentration 145-166 mEq/l; infusion rate 1.2-2 l/h). A polyacrylonitrile hollow fiber AN69 HF 1.2 sqm dialyzer is employed. In acute studies pCO2 remains stable throughout the treatment, as well as pCO2. We have found a significant inverse correlation between delta[HCO3-] pre and post treatment and basal [HCO3-] (r = -0.88; p less than 0.001), with an excellent correction of uremic acidosis, avoiding post dialytic alkalosis. Our long term experience on 6 patients followed up to 31 months, allows us to consider AFB as a feasible and safe treatment, offering a good correction of uremic acidosis and an excellent hemodynamic tolerance. We propose AFB as a competitive technique with respect to bicarbonate hemodialysis, hemodiafiltration and standard biofiltration. PMID:2167517

Quarello, F; Boero, R; Martina, G; Formica, M; Guarena, C; Beltrame, G; Scalzo, B; Forneris, G; Piccoli, G

1990-01-01

76

Molecular Structure of Ammonium ion  

NSDL National Science Digital Library

The first widespread production of ammonium compounds occurred during the 1890s when ammonium sulfate was produced as a by-product from coke oven gas. Ammonium ion is produced as a product of the reaction of water and ammonia. Often, ammonium salts are isomorphous. They have a similar solubility to potassium and rubidium salts, whose ions are similar in size to ammonium. The ion is most stable in the presence of a large compound with a single negative charge.

2002-09-10

77

Mechanisms of Contrast-Induced Nephropathy Reduction for Saline (NaCl) and Sodium Bicarbonate (NaHCO3)  

PubMed Central

Nephropathy following contrast media (CM) exposure is reduced by administration before, during, and after the contrast procedure of either isotonic sodium chloride solution (Saline) or isotonic sodium bicarbonate solution (IsoBicarb). The reasons for this reduction are not well established for either sodium salt; probable mechanisms are discussed in this paper. For Saline, the mechanism for the decrease in CIN is likely related primarily to the increased tubular flow rates produced by volume expansion and therefore a decreased concentration of the filtered CM during transit through the kidney tubules. Furthermore, increased tubular flow rates produce a slight increase in tubular pH resulting from a fixed acid excretion in an increased tubular volume. The mechanism for the decreased CIN associated with sodium bicarbonate includes the same mechanisms listed for Saline in addition to a renal pH effect. Increased filtered bicarbonate anion raises both tubular pH and tubular bicarbonate anion levels toward blood physiologic levels, thus providing increased buffer for reactive oxygen species (ROS) formed in the tubules as a result of exposure to CM in renal tubular fluid. PMID:24826379

Burgess, W. Patrick; Walker, Phillip J.

2014-01-01

78

Effects of Solarization and Ammonium Amendments on Plant-Parasitic Nematodes  

PubMed Central

The effects of soil solarization and ammonium bicarbonate or ammonium sulfate against plant-parasitic nematodes on yellow squash (Cucurbita pepo) and on vinca (Catharanthus roseus) were evaluated at two sites. Solarization for 3 weeks in the spring suppressed population levels of Belonolaimus longicaudatus, Criconemella spp., and Dolichodorus heterocephalus throughout the growing season on both crops at both sites. Levels of Meloidogyne incognita were suppressed initially, but population densities increased by the end of the crop in several cases. In one site, numbers of Paratrichodorus minor resurged following solarization to levels that were greater than those present in unsolarized control plots. The effect of solarization was not enhanced by combination with ammonium amendments, but, in one site, application of ammonium bicarbonate or ammonium sulfate resulted in lower numbers of B. longicaudatus than in the unamended control. Additional research and improved efficacy of candidate amendments are required before they can be successfully integrated with solarization for nematode management. Efficacy of solarization against plant-parasitic nematodes was achieved despite a relatively short (3 weeks) solarization period. PMID:19271007

McSorley, R.; McGovern, R. J.

2000-01-01

79

Bicarbonate-dependent effect of hydrogen sulfide on vascular contractility in rat aortic rings.  

PubMed

Hydrogen sulfide (H(2)S), an endogenous gaseous mediator, produces both vasorelaxation and vasoconstriction at different concentrations. We found in the present study that NaHS, an H(2)S donor, produced stronger vasorelaxant and weaker vasoconstrictive effects in HEPES solution compared with those achieved in Krebs solution. We further screened the buffer components and found that bicarbonate (HCO(3)(-)) was the ion to influence the effect of H(2)S. After examining the vasorelaxant effects of acetylcholine, a vasodilator by releasing nitric oxide, and isoprenaline, a ?-adrenoceptor agonist, in HEPES and Krebs buffers, we found the HCO(3)(-)-dependent effect was specific to H(2)S. Blockade of anion exchanger-2 activity with 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) or with HCO(3)(-)-free solution abolished the vasoconstrictive effect of NaHS. Moreover, NaHS decreased nitric oxide level in the rat aorta in HCO(3)(-)-containing buffer, but this effect was abolished by HCO(3)(-)-free buffer or DIDS. In summary, we found for the first time that H(2)S stimulates anion exchanger to transport extracellular HCO(3)(-) in exchange for intracellular superoxide anions, which may further inactivate nitric oxide and induces vasoconstriction. PMID:20660164

Liu, Yi-Hong; Bian, Jin-Song

2010-10-01

80

Infrared band intensities in ammonium hydroxide and ammonium salts  

NASA Technical Reports Server (NTRS)

We have applied Kramers-Kronig analysis to reflection spectra to determine the optical constants of ammonium hydroxide and of aqueous solutions of ammonium chloride and bromide. From considerations of the absorption indices k(nu) we conclude that ammonium hydroxide consists of a solution of NH3 in water, in which NH3 molecules are hydrogen bonded to neighboring water molecules. The spectrum of ammonium hydroxide differs from the spectra of ammonium salts, in which bands characteristic of NH4(+) ions are prominent. The existence of ammonium hydroxide as an aerosol in planetary atmospheres is briefly discussed

Sethna, P. P.; Downing, H. D.; Pinkley, L. W.; Williams, D.

1978-01-01

81

Electroantennogram and behavioral responses of Anastrepha suspensa (Diptera: Tephritidae) to putrescine and ammonium bicarbonate lures  

Technology Transfer Automated Retrieval System (TEKTRAN)

At present, the most effective synthetic lures for pest Anastrepha fruit flies are multi-component blends that include an ammonia-emitting substrate and the diamine synergist, putrescine (1,4-diaminobutane). Both chemicals are regarded as protein-feeding cues which result in female-biased attractio...

82

Bray\\/Kurtz, Mehlich III, AB\\/D and ammonium acetate extractions of P, K and MG in four oklahoma soils  

Microsoft Academic Search

Multi?element soil extraction solutions offer increased convenience in soil testing laboratory operations. The recently developed Mehlich III and ammonium bicarbonate?DTPA multi?element extraction solutions were each compared with the more conventional Bray\\/Kurtz extractant for P determination and with 1N ammonium acetate for K and Mg determinations. The latter two solutions are single and tri?element extractants in current use by the Oklahoma

E. A. Hanlon; G. V. Johnson

1984-01-01

83

40 CFR 180.1176 - Sodium bicarbonate; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Sodium bicarbonate; exemption from the requirement of...From Tolerances § 180.1176 Sodium bicarbonate; exemption from the requirement of... The biochemical pesticide sodium bicarbonate is exempted from the...

2010-07-01

84

40 CFR 415.140 - Applicability; description of the sodium bicarbonate production subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the sodium bicarbonate production subcategory. 415.140...MANUFACTURING POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory § 415.140 Applicability; description of the sodium bicarbonate production subcategory. The...

2010-07-01

85

40 CFR 180.1176 - Sodium bicarbonate; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Sodium bicarbonate; exemption from the requirement...Tolerances § 180.1176 Sodium bicarbonate; exemption from the requirement... The biochemical pesticide sodium bicarbonate is exempted from the...

2012-07-01

86

40 CFR 180.1176 - Sodium bicarbonate; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Sodium bicarbonate; exemption from the requirement...Tolerances § 180.1176 Sodium bicarbonate; exemption from the requirement... The biochemical pesticide sodium bicarbonate is exempted from the...

2011-07-01

87

40 CFR 180.1176 - Sodium bicarbonate; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Sodium bicarbonate; exemption from the requirement...Tolerances § 180.1176 Sodium bicarbonate; exemption from the requirement... The biochemical pesticide sodium bicarbonate is exempted from the...

2013-07-01

88

40 CFR 180.1176 - Sodium bicarbonate; exemption from the requirement of a tolerance.  

... 2014-07-01 false Sodium bicarbonate; exemption from the requirement...Tolerances § 180.1176 Sodium bicarbonate; exemption from the requirement... The biochemical pesticide sodium bicarbonate is exempted from the...

2014-07-01

89

40 CFR 180.1177 - Potassium bicarbonate; exemption from the requirement of a tolerance.  

...2014-07-01 2014-07-01 false Potassium bicarbonate; exemption from the requirement...Exemptions From Tolerances § 180.1177 Potassium bicarbonate; exemption from the requirement...tolerance. The biochemical pesticide potassium bicarbonate is exempted from...

2014-07-01

90

Riparian Buffers for Wildlife Benefits of Riparian Buffers  

E-print Network

Riparian Buffers for Wildlife Benefits of Riparian Buffers Riparian buffers offer many benefits for wildlife; but they also improve water quality for humans. In general, the wider and more diversely planted the buffer, the more likely it is to yield positive benefits. A riparian buffer: Traps sediment. Runoff from

Boyer, Elizabeth W.

91

Therapy of Bicarbonate-losing Renal Tubular Acidosis  

PubMed Central

A 2-year-old-girl with severe bicarbonate-losing renal tubular acidosis was treated successively with bicarbonate, THAM, and two diuretics, hydrochlorothiazide and frusemide. Only with hydrochlorothiazide was adequate correction of the acid-base balance achieved. The relative importance of changes induced by this treatment in the extracellular fluid volume and in chloride depletion was assessed. PMID:5491880

Donckerwolcke, R. A.; Van Stekelenburg, G. J.; Tiddens, H. A.

1970-01-01

92

70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

70. INTERIOR VIEW OF AMMONIUM NITRATE HOUSE, LOOKING AT AMMONIUM NITRATE IN STORAGE. APRIL 18, 1919. - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

93

SUPPLEMENTAL INFORMATION Evaluation of Stainless Steel Cathodes and a Bicarbonate Buffer For  

E-print Network

of the GBM Setup Figure S.1 A picture of a gas bag (1) attached directly to a MEC (2), as per the setup of the GBM 1 2 #12;3 Figure S.2 A picture of a MEC (1) connected to a respirometer (2) from http we have pulled it out to show the flow path 2 1 1 2 3 #12;4 GBM Example Example GC output of a gas

94

Potassium bicarbonate, but not sodium bicarbonate, reduces urinary calcium excretion and improves calcium balance in healthy men  

Microsoft Academic Search

Potassium bicarbonate, but not sodium bicarbonate, reduces urinary calcium excretion and improves calcium balance in healthy men. Previous studies demonstrated that the administration of NaHCO3 or sodium citrate had either only a small effect to reduce urinary Ca excretion or no effect, but that potassium citrate significantly reduced urinary Ca excretion. In order to further evaluate and compare the effects

Jacob Lemann; Richard W Gray; Joan A Pleuss

1989-01-01

95

Comparison of ammonium bicarbonate?DTPA, ammonium carbonate, and ammonium oxalate to assess the availability of molybdenum in mine spoils and soils  

Microsoft Academic Search

A variety of extractants has been used to assess the availability of molybdenum (Mo) in soils. Most of the extractants have been studied from a deficiency aspect rather than for soils with Mo toxicity, and none of them have been used to extract available Mo from mine spoils. The purpose of this study was to examine the potential of different

L. Wang; K. J. Reddy; L. C. Munn

1994-01-01

96

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

2014-10-01

97

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2011 CFR

...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

2011-10-01

98

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2013 CFR

...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

2013-10-01

99

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2012 CFR

...Ammonium nitrate and ammonium nitrate fertilizers. 148.205 Section 148.205 ...Ammonium nitrate and ammonium nitrate fertilizers. (a) This section applies to...of ammonium nitrate and the following fertilizers composed of uniform,...

2012-10-01

100

An optical-density-based feedback feeding method for ammonium concentration control in Spirulina platensis cultivation.  

PubMed

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium- N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l·d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4 mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations. PMID:22580316

Bao, Yilu; Wen, Shumei; Cong, Wei; Wu, Xia; Ning, Zhengxiang

2012-07-01

101

Bicarbonate sulfate exchange in canalicular rat liver plasma membrane vesicles  

SciTech Connect

The mechanism(s) and driving forces for biliary excretion of sulfate were investigated in canalicular rat liver plasma membrane vesicles (cLPM). Incubation of cLPM vesicles in the presence of an inside-to-outside (in, out) bicarbonate gradient but not pH or out-to-in sodium gradients, stimulated sulfate uptake 10-fold compared with the absence of bicarbonate and approximately 2-fold above sulfate equilibrium (overshoot). Initial rates of this bicarbonate gradient-driven ({sup 35}S)-sulfate uptake were saturable with increasing concentrations of sulfate and could be inhibited by probenecid, N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate, acetazolamide, furosemide, 4-acetamideo-4{prime}-isothiocyanostilbene-2,2{prime}-disulfonic acid, and 4,4{prime}-diisothiocyanostilbene-2,2{prime}-disulfonic acid (IC{sub 50}, {approximately}40 {mu}M). Cisinhibition of initial bicarbonate gradient-stimulated sulfate uptake and transstimulation of sulfate uptake in the absence of bicarbonate were observed with sulfate, thiosulfate, and oxalate but not with chloride, nitrate, phosphate, acetate, lactate, glutamate, aspartate, cholate, taurocholate, dehydrocholate, taurodehydrocholate, and reduced or oxidized glutathione. These findings indicate the presence of a sulfate (oxalate)-bicarbonate anion exchange system in canalicular rat liver plasma membranes. These findings support the concept that bicarbonate-sensitive transport system might play an important role in bile acid-independent canalicular bile formation.

Meier, P.J.; Valantinas, J.; Hugentobler, G.; Rahm, I. (University Hospital, Zurich (Switzerland))

1987-10-01

102

Ammonium Homeostasis and Human Rhesus Glycoproteins  

Microsoft Academic Search

The brain ammonium production is detoxified by astrocytes, the gut ammonium production is detoxified by hepatic cells, and the renal ammonium production plays a major role in renal acid excretion. As a result of ammonium handling in these organs, the ammonium and pH values are strictly regulated in plasma. Up until recently, it was accepted that mammalian cell transmembrane ammonium

Gabrielle Planelles

2007-01-01

103

Protective effect of bicarbonate against extraction of the extrinsic proteins of the water-oxidizing complex from Photosystem II membrane fragments  

Microsoft Academic Search

A protective effect of bicarbonate (BC) against extraction of the extrinsic proteins, predominantly the Mn-stabilizing protein (PsbO protein), during treatment of Photosystem II (PS II) membrane fragment from pea with 2 M urea, and at low pH (using incubation in 0.2 M glycine–HCl buffer, pH 3.5 or 0.5 M citrate buffer, pH 4.0–4.5) was detected. It was shown that the extraction of the

Olga V. Pobeguts; Tatiana N. Smolova; Olga M. Zastrizhnaya; Vyacheslav V. Klimov

2007-01-01

104

Structure, hydrogen bonding and thermal expansion of ammonium carbonate monohydrate.  

PubMed

We have determined the crystal structure of ammonium carbonate monohydrate, (NH4)2CO3·H2O, using Laue single-crystal diffraction methods with pulsed neutron radiation. The crystal is orthorhombic, space group Pnma (Z = 4), with unit-cell dimensions a = 12.047?(3), b = 4.453?(1), c = 11.023?(3)?Å and V = 591.3?(3)?Å(3) [?calc = 1281.8?(7)?kg?m(-3)] at 10?K. The single-crystal data collected at 10 and 100?K are complemented by X-ray powder diffraction data measured from 245 to 273?K, Raman spectra measured from 80 to 263?K and an athermal zero-pressure calculation of the electronic structure and phonon spectrum carried out using density functional theory (DFT). We find no evidence of a phase transition between 10 and 273?K; above 273?K, however, the title compound transforms first to ammonium sesquicarbonate monohydrate and subsequently to ammonium bicarbonate. The crystallographic and spectroscopic data and the calculations reveal a quite strongly hydrogen-bonded structure (EHB ? 30-40?kJ?mol(-1)), on the basis of H...O bond lengths and the topology of the electron density at the bond critical points, in which there is no free rotation of the ammonium cation at any temperature. The barrier to free rotation of the ammonium ions is estimated from the observed librational frequency to be ??36?kJ?mol(-1). The c-axis exhibits negative thermal expansion, but the thermal expansion behaviour of the a and b axes is ormal. PMID:25449618

Fortes, A Dominic; Wood, Ian G; Alfè, Dario; Hernández, Eduardo R; Gutmann, Matthias J; Sparkes, Hazel A

2014-12-01

105

Bile Acids and Bicarbonate Inversely Regulate Intracellular Cyclic di-GMP in Vibrio cholerae  

PubMed Central

Vibrio cholerae is a Gram-negative bacterium that persists in aquatic reservoirs and causes the diarrheal disease cholera upon entry into a human host. V. cholerae employs the second messenger molecule 3?,5?-cyclic diguanylic acid (c-di-GMP) to transition between these two distinct lifestyles. c-di-GMP is synthesized by diguanylate cyclase (DGC) enzymes and hydrolyzed by phosphodiesterase (PDE) enzymes. Bacteria typically encode many different DGCs and PDEs within their genomes. Presumably, each enzyme senses and responds to cognate environmental cues by alteration of enzymatic activity. c-di-GMP represses the expression of virulence factors in V. cholerae, and it is predicted that the intracellular concentration of c-di-GMP is low during infection. Contrary to this model, we found that bile acids, a prevalent constituent of the human proximal small intestine, increase intracellular c-di-GMP in V. cholerae. We identified four c-di-GMP turnover enzymes that contribute to increased intracellular c-di-GMP in the presence of bile acids, and deletion of these enzymes eliminates the bile induction of c-di-GMP and biofilm formation. Furthermore, this bile-mediated increase in c-di-GMP is quenched by bicarbonate, the intestinal pH buffer secreted by intestinal epithelial cells. Our results lead us to propose that V. cholerae senses distinct microenvironments within the small intestine using bile and bicarbonate as chemical cues and responds by modulating the intracellular concentration of c-di-GMP. PMID:24799624

Koestler, Benjamin J.

2014-01-01

106

Distal Renal Tubular Acidosis in Infancy: A Bicarbonate Wasting State  

ERIC Educational Resources Information Center

Studied were three unrelated infants with distal renal tubular acidosis (a condition characterized by an inability to acidify the urine to minimal pH levels resulting in the loss of bicarbonates). (DB)

Rodriguez-Soriano, J.; And Others

1975-01-01

107

BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL PAINTING  

EPA Science Inventory

This evaluation addressed product quality, waste reduction/pollution prevention and economics in replacing chemical solvent strippers with a bicarbonate of soda blasting technology for removal of paint from aircraft wheels. The evaluation was conducted in the Paint Stripping Sho...

108

BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL DEPAINTING  

EPA Science Inventory

This evaluation addressed product quality, waste reduction/pollution prevention and economics in replacing chemical solvent strippers with a bicarbonate of soda blasting technology for removal of point from aircraft wheels. he evaluation was conducted in the Paint Stripping Shop ...

109

Calcium mass balances in bicarbonate hemodialysis.  

PubMed

Dialysate calcium (Ca) concentration should be viewed as part of the integrated therapeutic regimen to control renal osteodystrophy and maintain normal mineral metabolism. The goals of this integrated approach are to keep the patient in a mild positive Ca mass balance (CaMB), to maintain normal serum Ca levels, to control plasma parathyroid hormone values to two to three times above normal levels, and to avoid soft-tissue calcifications. Thus, a correct net CaMB during hemodialysis (HD) is crucial in the treatment of renal osteodystrophy. Very few studies have been published which measured CaMBs in bicarbonate HD. This is mainly due to the technical difficulties in achieving an accurate measurement of CaMBs owing to the need for the collection of the total spent dialysate or of a proportional aliquot of it. Whereas no doubt exists about the fact that an inlet dialysate Ca concentration (CaD) of 1.75?mmol/L leads to a positive CaMB, more controversial is this issue, when dealing with a CaD of 1.50?mmol/L and, even more, when dealing with a CaD of 1.25?mmol/L. Another important issue is the appropriate CaD in long-hour slow-flow nocturnal HD. Finally, which CaMB should we study: ionized CaMB or total CaMB? This issue is largely discussed in the review. PMID:21603102

Basile, Carlo

2011-01-01

110

VIEW OF RBC (REFINED BICARBONATE) BUILDING LOOKING NORTHEAST. DEMOLITION IN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF RBC (REFINED BICARBONATE) BUILDING LOOKING NORTHEAST. DEMOLITION IN PROGRESS. "ARM & HAMMER BAKING SODA WAS MADE HERE FOR OVER 50 YEARS AND THEN SHIPPED ACROSS THE STREET TO THE CHURCH & DWIGHT PLANT ON WILLIS AVE. (ON THE RIGHT IN THIS PHOTO). LAYING ON THE GROUND IN FRONT OF C&D BUILDING IS PART OF AN RBC DRYING TOWER. - Solvay Process Company, Refined Bicarbonate Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

111

Serum bicarbonate and mortality in adults in NHANES III  

PubMed Central

Background Low serum bicarbonate concentration is a risk factor for death in people with chronic kidney disease (CKD). Whether low serum bicarbonate is a mortality risk factor for people without CKD is unknown. Methods National Health and Nutrition Examination Survey III (NHANES III) adult participants were categorized into one of four serum bicarbonate categories: <22, 22–25, 26–30 and ?31 mM. Cox models were used to determine the hazards of death in each serum bicarbonate category, using 26–30 mM as the reference group, in the (i) entire population, (ii) non-CKD subgroup and (iii) CKD subgroup. Results After adjusting for age, gender, race, estimated glomerular filtration rate, albuminuria, diuretic use, smoking, C-reactive protein, cardiovascular disease, protein intake, diabetes, hypertension, body mass index, lung disease and serum albumin, the hazards of death in the <22 mM serum bicarbonate category were 1.75 (95% CI: 1.12–2.74), 1.56 (95% CI: 0.78–3.09) and 2.56 (95% CI: 1.49–4.38) in the entire population, non-CKD subgroup and CKD subgroup, respectively, compared with the reference group. Hazard ratios in the other serum bicarbonate categories in the entire population and non-CKD and CKD subgroups did not differ from the reference group. Conclusions Among the NHANES III participants, low serum bicarbonate was not observed to be a strong predictor of mortality in people without CKD. However, low serum bicarbonate was associated with a 2.6-fold increased hazard of death in people with CKD. PMID:23348878

Raphael, Kalani L.; Zhang, Yingying; Wei, Guo; Greene, Tom; Cheung, Alfred K.; Beddhu, Srinivasan

2013-01-01

112

Bicarbonate requirement for the donor side of photosystem II  

Microsoft Academic Search

Suppression of electron flow (and its subsequent restoration with 3–10 mM NaHCO3) on the donor side of photosystem II is shown upon either a partial depletion of pea subchloroplast membranes in bicarbonate or the addition of 5–20 ?M formate. At higher concentrations (5 mM) formate induces the known ‘bicarbonate effect’ on the acceptor side of photosystem II. In preparations depleted

V. V. Klimov; S. I. Allakhverdiev; Ya. M. Feyziev; S. V. Baranov

1995-01-01

113

Effect of Sodium Bicarbonate Preloading on Ischemic Renal Failure  

Microsoft Academic Search

Rats pretreated with sodium bicarbonate were functionally protected from the damage of bilateral renal artery occlusion. The rise in serum creatinine (day 1 minus day 0) during the first 24 h after ischemia was 2.88 ± 0.28 mg% in the bicarbonate-loaded animals versus 3.90 ± 0.26 mg% in their matched controls (p ? 0.01). Pretreatment with acetazolamide produced a similar

James L. Atkins

1986-01-01

114

Sevelamer carbonate increases serum bicarbonate in pediatric dialysis patients.  

PubMed

Sevelamer hydrochloride (HCl), a calcium-free phosphate binder, is increasingly used due to concerns related to calcium exposure and the development of vascular calcifications. However, a common side effect of sevelamer HCl, metabolic acidosis, is particularly concerning in children, as it can contribute to poor growth. Sevelamer carbonate is now available and has been shown to increase serum bicarbonate in adult patients. We conducted a prospective single-center study of pediatric dialysis patients comparing serum bicarbonate before and 3 months after a switch from sevelamer HCl to sevelamer carbonate. Inclusion criteria were a minimum of 3 months of dialysis therapy and either a serum bicarbonate <20 mmol/L or the need for sodium bicarbonate supplementation. Ten hemodialysis and 14 peritoneal dialysis patients, aged 16 +/- 3 years, were enrolled. Whereas serum calcium and phosphorus remained unchanged, serum bicarbonate increased from 20 (17.2-22.0) to 24.5 (20.75-26) mmol/L (p < 0.001) after 3 months of sevelamer carbonate therapy. Sodium bicarbonate supplementation was stopped in all patients (n = 10), reducing the mean daily sodium intake by an average of 2.3 g per patient. These results demonstrate that sevelamer carbonate is an effective phosphate binder that improves acid-base status in pediatric dialysis patients. PMID:19876653

Gonzalez, Elsa; Schomberg, John; Amin, Nimisha; Salusky, Isidro B; Zaritsky, Joshua

2010-02-01

115

Exploring factors controlling the thermal behavior of ammonium perchlorate and ammonium nitrate energetic systems.  

E-print Network

??This research project characterizes ammonium nitrate (AN) and ammonium perchlorate (AP) to assist in the parameter optimization of ammonium-salt propellants. Throughout these studies, the effective… (more)

Lang, Anthony J.

2009-01-01

116

49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410...Materials § 176.410 Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. (a)...

2013-10-01

117

Investigation of solid-phase buffers for sulfur-oxidizing autotrophic denitrification.  

PubMed

This paper investigates biological denitrification using autotrophic microorganisms that use elemental sulfur as an electron donor. In this process, for each gram of nitrate-nitrogen removed, approximately 4.5 g of alkalinity (as calcium carbonate) are consumed. Because denitrification is severely inhibited below pH 5.5, and alkalinity present in the influent wastewaters is less than the alkalinity consumed, an external buffer was needed to arrest any drop in pH from alkalinity consumption. A packed-bed bioreactor configuration is ideally suited to handle variations in flow and nitrate loading from decentralized wastewater treatment systems, as it is a passive system and thus requires minimal maintenance; therefore, a solid-phase buffer packed with the elemental sulfur in the bioreactor is most suitable. In this research, marble chips, limestone, and crushed oyster shells were tested as solid-phase buffers. Bench- and field-scale studies indicated that crushed oyster shell was the most suitable buffer based on (1) the rate of dissolution of buffer and the buffering agent released (carbonate, bicarbonate, or hydroxide), (2) the ability of the buffer surface to act as host for microbial attachment, (3) turbidity of the solution upon release of the buffering agent, and (4) economics. PMID:18198697

Sengupta, Sukalyan; Ergas, Sarina J; Lopez-Luna, Erika

2007-12-01

118

Proteins contribute insignificantly to the intrinsic buffering capacity of yeast cytoplasm  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer We predicted buffering capacity of yeast proteome from protein abundance data. Black-Right-Pointing-Pointer We measured total buffering capacity of yeast cytoplasm. Black-Right-Pointing-Pointer We showed that proteins contribute insignificantly to buffering capacity. -- Abstract: Intracellular pH is maintained by a combination of the passive buffering of cytoplasmic dissociable compounds and several active systems. Over the years, a large portion of and possibly most of the cell's intrinsic (i.e., passive non-bicarbonate) buffering effect was attributed to proteins, both in higher organisms and in yeast. This attribution was not surprising, given that the concentration of proteins with multiple protonable/deprotonable groups in the cell exceeds the concentration of free protons by a few orders of magnitude. Using data from both high-throughput experiments and in vitro laboratory experiments, we tested this concept. We assessed the buffering capacity of the yeast proteome using protein abundance data and compared it to our own titration of yeast cytoplasm. We showed that the protein contribution is less than 1% of the total intracellular buffering capacity. As confirmed with NMR measurements, inorganic phosphates play a crucial role in the process. These findings also shed a new light on the role of proteomes in maintaining intracellular pH. The contribution of proteins to the intrinsic buffering capacity is negligible, and proteins might act only as a recipient of signals for changes in pH.

Poznanski, Jaroslaw [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland)] [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland); Szczesny, Pawel [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland) [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland); Institute of Experimental Plant Biology and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw (Poland); Ruszczynska, Katarzyna [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland)] [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland); Zielenkiewicz, Piotr [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland) [Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw (Poland); Institute of Experimental Plant Biology and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw (Poland); Paczek, Leszek, E-mail: leszek.paczek@wum.edu.pl [Department of Immunology, Transplantology and Internal Medicine, Warsaw Medical University, Warsaw (Poland)] [Department of Immunology, Transplantology and Internal Medicine, Warsaw Medical University, Warsaw (Poland)

2013-01-11

119

21 CFR 582.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Ammonium carbonate. 582.1137 Section 582.1137...General Purpose Food Additives § 582.1137 Ammonium carbonate. (a) Product. Ammonium carbonate. (b) Conditions of use....

2010-04-01

120

21 CFR 582.1139 - Ammonium hydroxide.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Ammonium hydroxide. 582.1139 Section 582.1139...General Purpose Food Additives § 582.1139 Ammonium hydroxide. (a) Product. Ammonium hydroxide. (b) Conditions of use....

2010-04-01

121

21 CFR 556.375 - Maduramicin ammonium.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Maduramicin ammonium. 556.375 Section 556.375 ...Animal Drugs § 556.375 Maduramicin ammonium. A tolerance is established for residues of maduramicin ammonium in chickens as follows: (a) A...

2010-04-01

122

76 FR 47238 - Ammonium Nitrate From Russia  

Federal Register 2010, 2011, 2012, 2013

...731-TA-856; Second Review] Ammonium Nitrate From Russia Determination On...the antidumping duty order on ammonium nitrate from Russia would be likely...4249 (August 2011), entitled Ammonium Nitrate from Russia:...

2011-08-04

123

76 FR 11273 - Ammonium Nitrate From Russia  

Federal Register 2010, 2011, 2012, 2013

...731-TA-856 (Second Review)] Ammonium Nitrate From Russia AGENCY: United...the suspended investigation on ammonium nitrate from Russia...the suspended investigation on ammonium nitrate from Russia would be...

2011-03-01

124

76 FR 70366 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...NPRM for the Ammonium Nitrate Security Program. The agenda for the public...Department's Ammonium Nitrate Security Program Web site, at http://www.dhs...programs/ammonium-nitrate-security-program.shtm. This...

2011-11-14

125

76 FR 62311 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...NPRM) for the Ammonium Nitrate Security Program. The agenda for the public...Department's Ammonium Nitrate Security Program Web site in mid-October at http...programs/ammonium-nitrate-security-program.shtm. Each...

2011-10-07

126

Short-term assay of soil urease activity using colorimetric determination of ammonium  

Microsoft Academic Search

A rapid assay for soil urease in the absence of bacteriostatic agents has been developed. The method comprises incubation of soil with an aqueous or buffered urea solution, extraction of ammonium with 1 N KCl and 0.01 NHCl and colorimetric NH4+ determination by a modified indophenol reaction. The method is characterized by high sensitivity and stability of the coloured complex

E. Kandeler; H. Gerber

1988-01-01

127

Virginia Tech - Buffer Pool  

NSDL National Science Digital Library

Allows user to select from FIFO, LRU, and LFU page replacement strategies. User then gives a series of page requests and the AV shows the decisions made regarding page replacement. Simple to use, clearly shows the process. It would be nice if the user could pick the size of the backing memory and the buffer pool. Recommended as lecture aide, standalone, self-study suppliment to tutorial or lecture.

Shaffer, Cliff; Sariaya, Purvi

128

Bicarbonate produced from carbon capture for algae culture.  

PubMed

Using captured CO(2) to grow microalgae is limited by the high cost of CO(2) capture and transportation, as well as significant CO(2) loss during algae culture. Moreover, algae grow poorly at night, but CO(2) cannot be temporarily stored until sunrise. To address these challenges, we discuss a process where CO(2) is captured as bicarbonate and used as feedstock for algae culture, and the carbonate regenerated by the culture process is used as an absorbent to capture more CO(2). This process would significantly reduce carbon capture costs because it does not require additional energy for carbonate regeneration. Furthermore, not only would transport of the aqueous bicarbonate solution cost less than for that of compressed CO(2), but using bicarbonate would also provide a superior alternative for CO(2) delivery to an algae culture system. PMID:21775005

Chi, Zhanyou; O'Fallon, James V; Chen, Shulin

2011-11-01

129

Enhanced sonochemical degradation of bisphenol-A by bicarbonate ions.  

PubMed

Sonochemical elimination of organic pollutants can take place through two degradation pathways. Molecules with relatively large Henry's law constants will be incinerated inside the cavitation bubble, while nonvolatile molecules with low Henry's law constants will be oxidised by the OH(*) ejected from the bubble of cavitation. Taking bisphenol-A as a model pollutant, this study points out an alternate degradation route, mediated by bicarbonate ions, which is significant for the elimination of micro-pollutants at concentrations present in natural waters. In this process, OH(*) radicals react with bicarbonate ions to produce the carbonate radical, which, unlike the OH(*) radical, can migrate towards the bulk of the solution and therefore induce the degradation of the micro-pollutants present in the bulk solution. As a consequence, initial degradation rate is increased by a factor 3.2 at low concentration of bisphenol-A (0.022 micromol l(-1)) in presence of bicarbonate in water. PMID:19535280

Pétrier, Christian; Torres-Palma, Ricardo; Combet, Evelyne; Sarantakos, Georgios; Baup, Stéphane; Pulgarin, César

2010-01-01

130

Microwave Decomposition of Solid Crystalline Ammonium Paratungstate and Ammonium Metatungstate  

NASA Astrophysics Data System (ADS)

The potential for microwave decomposition of solid crystalline ammonium paratungstate (APT) and ammonium metatungstate (AMT) was investigated. It was observed that APT and AMT interact with 2.45-GHz microwave radiation. Samples of ammonium paratungstate (20-50 g) were successfully converted into WO 3- x (0 ? x ? 0.2). A wide variety of morphological parameters were found. The interaction of AMT with the 2.45-GHz microwave radiation resulted in the partial loss of crystalline water and the partial dissolution of the sample in the released water.

Pfeifer, J.; Badaljan, E. G.; Tekula-Buxbaum, P.; Vadasdi, K.

1993-08-01

131

Acid Rain Experiments: Soil Buffering  

NSDL National Science Digital Library

This experiment will help students understand that soil sometimes contains substances, like limestone, that buffer acids or bases, and that some salts in soil may also act as buffers. They will collect soil samples from their lawn, garden, or school and look for buffering effects by observing the pH change of an acid mixture poured through the samples. If the water collected from the sample is less acidic than the original mixture, then the soil is buffering some of the acid. If it does not change, then the soil may not be capable of buffering acids.

132

Facilitated Lactate Transport by MCT1 when Coexpressed with the Sodium Bicarbonate Cotransporter (NBC) in Xenopus Oocytes  

PubMed Central

Monocarboxylate transporters (MCT) and sodium-bicarbonate cotransporters (NBC) transport acid/base equivalents and coexist in many epithelial and glial cells. In nervous systems, the electroneutral MCT1 isoform cotransports lactate and other monocarboxylates with H+, and is believed to be involved in the shuttling of energy-rich substrates between astrocytes and neurons. The NBC cotransports bicarbonate with sodium and generates a membrane current. We have expressed these transporter proteins, cloned from rat brain (MCT1) and human kidney (NBC), alone and together, by injecting the cRNA into oocytes of the frog Xenopus laevis, and measured intracellular pH changes and membrane currents under voltage-clamp with intracellular microelectrodes, and radiolabeled lactate uptake into the oocytes. We determined the cytosolic buffer capacity, the H+ and lactate fluxes as induced by 3 and 10 mM lactate in oocytes expressing MCT1 and/or NBC, and in water-injected oocytes, in salines buffered with 5 mM HEPES alone or with 5% CO2/10 mM HCO3? (pH 7.0). In MCT1 + NBC- but not in MCT1- or NBC-expressing oocytes, lactate activated a Na+- and HCO3?-dependent membrane current, indicating that lactate/H+ cotransport via MCT1, due to the induced pH change, stimulates NBC activity. Lactate/H+ cotransport by MCT1 was increased about twofold when MCT1 was expressed together with NBC. Our results suggest that the facilitation of MCT1 transport activity is mainly due to the increase in apparent buffer capacity contributed by the NBC, and thereby suppresses the build-up of intracellular H+ during the influx of lactate/H+, which would reduce MCT1 activity. Hence these membrane transporters functionally cooperate and are able to increase ion/metabolite transport activity. PMID:14695265

Becker, Holger M.; Bröer, Stefan; Deitmer, Joachim W.

2004-01-01

133

Buffered lidocaine for skin infiltration prior to hemodialysis.  

PubMed

This study compared the effects of buffered versus unbuffered lidocaine when used as local anesthetic in preparation for cannulation of the arterial and venous sites of children requiring hemodialysis. The subjects for this study were seven children, ages 6-18 years, observed during 101 dialysis treatments. For each subject undergoing hemodialysis on a given day, one syringe containing 1% lidocaine (L) and one containing buffered lidocaine (BL) were prepared. The BL solution was prepared by adding 2 mL of 8.4% sodium bicarbonate to 20 mL of 1% lidocaine just prior to use. The choice of local anesthetic used for cannulation of the arterial or venous site was randomly assigned to be either L or BL. Nurses, raters, and subjects were blind to contents of the syringe. The procedures for piercing the skin, pausing, and infiltrating were standardized, as was the volume administered. Speed of injection was not controlled. Comparisons of self-reported pain and behavioral observations for L versus BL revealed no significant differences for pain of infiltration or pain of cannulation. Technique variables such as the speed of injection, which tended to be very slow for these children, appear to significantly influence infiltration pain and the relative merits of buffering. PMID:7629414

Richtsmeier, A J; Hatcher, J W

1995-04-01

134

Sodium Bicarbonate for the Treatment of Lactic Acidosis  

Microsoft Academic Search

Lactic acidosis often challenges the intensivist and is associated with a strikingly high mortality. Treatment involves discerning and correcting its underlying cause, ensuring adequate oxygen delivery to tissues, reducing oxygen demand through sedation and mechanical ventilation, and (most controversially) attempting to alkalinize the blood with IV sodium bicarbonate. Here we review the literature to answer the following questions: Is a

Sean M. Forsythe; Gregory A. Schmidt

135

High performance ammonium nitrate propellant  

NASA Technical Reports Server (NTRS)

A high performance propellant having greatly reduced hydrogen chloride emission is presented. It is comprised of: (1) a minor amount of hydrocarbon binder (10-15%), (2) at least 85% solids including ammonium nitrate as the primary oxidizer (about 40% to 70%), (3) a significant amount (5-25%) powdered metal fuel, such as aluminum, (4) a small amount (5-25%) of ammonium perchlorate as a supplementary oxidizer, and (5) optionally a small amount (0-20%) of a nitramine.

Anderson, F. A. (inventor)

1979-01-01

136

Effect of excess sodium bicarbonate on the blood volume and erythrocyte deformability of broiler chickens  

Microsoft Academic Search

Broiler chickens were treated with 7.5% of sodium bicarbonate in their drinking water from 7 to 29 days of age to test the hypothesis that excess dietary sodium bicarbonate increases blood volume and decreases erythrocyte deformability thus contributing to the development of pulmonary hypertension?induced right ventricular failure and ascites. Sodium bicarbonate treatment resulted in 16% mortality from ascites compared to

S. M. Mirsalimi; R. J. Julian

1993-01-01

137

Buffer capacity of the coelomic fluid in echinoderms.  

PubMed

The increase in atmospheric CO2 due to anthropogenic activity results in an acidification of the surface waters of the oceans. The impact of these chemical changes depends on the considered organisms. In particular, it depends on the ability of the organism to control the pH of its inner fluids. Among echinoderms, this ability seems to differ significantly according to species or taxa. In the present paper, we investigated the buffer capacity of the coelomic fluid in different echinoderm taxa as well as factors modifying this capacity. Euechinoidea (sea urchins except Cidaroidea) present a very high buffer capacity of the coelomic fluid (from 0.8 to 1.8mmolkg(-1) SW above that of seawater), while Cidaroidea (other sea urchins), starfish and holothurians have a significantly lower one (from -0.1 to 0.4mmolkg(-1) SW compared to seawater). We hypothesize that this is linked to the more efficient gas exchange structures present in the three last taxa, whereas Euechinoidea evolved specific buffer systems to compensate lower gas exchange abilities. The constituents of the buffer capacity and the factors influencing it were investigated in the sea urchin Paracentrotus lividus and the starfish Asterias rubens. Buffer capacity is primarily due to the bicarbonate buffer system of seawater (representing about 63% for sea urchins and 92% for starfish). It is also partly due to coelomocytes present in the coelomic fluid (around 8% for both) and, in P. lividus only, a compound of an apparent size larger than 3kDa is involved (about 15%). Feeding increased the buffer capacity in P. lividus (to a difference with seawater of about 2.3mmolkg(-1) SW compared to unfed ones who showed a difference of about 0.5mmolkg(-1) SW) but not in A. rubens (difference with seawater of about 0.2 for both conditions). In P. lividus, decreased seawater pH induced an increase of the buffer capacity of individuals maintained at pH7.7 to about twice that of the control individuals and, for those at pH7.4, about three times. This allowed a partial compensation of the coelomic fluid pH for individuals maintained at pH7.7 but not for those at pH7.4. PMID:23752123

Collard, Marie; Laitat, Kim; Moulin, Laure; Catarino, Ana I; Grosjean, Philippe; Dubois, Philippe

2013-09-01

138

Ammonium transport in the kidney.  

PubMed

Ammonium excretion into the urine is the main mechanism of renal acid excretion. Ammonium is produced by epithelial cells of the proximal tubule and then secreted into the luminal fluid. However, before its final excretion into urine, ammonium ion is reabsorbed by the thick ascending limb (TAL), and accumulated in the interstitium to build up a corticopapillary gradient of ammonium which is necessary for the final diffusion of the gas NH3 in parallel to active proton secretion. Recent evidence has been provided by the study of several mouse models of renal acidosis. Particularly, it has been shown that the Na+/H+ exchanger NHE4 is a critical step of ammonium absorption by the TAL, and also that NH3 diffusion across the membrane of collecting duct cells requires the presence of the recently identified gas channel Rhcg. This review is an update on the different mechanisms of ammonium transport along the nephron, with a particular emphasis on these new molecules. PMID:21170885

Eladari, Dominique; Chambrey, Régine

2010-01-01

139

In-situ leaching of South Texas uranium ores - 2. Oxidative removal of adsorbed ammonium ions with sodium hypochlorite  

SciTech Connect

This paper reports a laboratory study of the oxidative destruction, by sodium hypochlorite, of ammonium ions adsorbed on relatively reduced South Texas uranium ore. Included are an assessment of reaction stoichiometry, determination of some major reaction pathways and side reactions, and identification of several intermediates. Adsorbed ammonium ions were completely removed by 0.5% sodium hypochlorite with the concentration of ammonia in the effluent falling to a very low value after 10-15 pore volumes of the oxidant. Substantial quantities of sulfate, reflecting oxidation of sulfide minerals such as pyrite, were formed. Large amounts of uranium were leached out, and substantial amounts of calcium and magnesium ions were also produced during the pre-saturation with ammonium bicarbonate during the oxidation stage. 28 refs.

Paul, J.M.; Johnson, W.F.; Fletcher, A.; Venuto, P.B.

1981-01-01

140

Prediction of aerobic and anaerobic capacities of elite cyclists from changes in lactate during isocapnic buffering phase.  

PubMed

Hasanli, M, Nikooie, R, Aveseh, M, and Mohammad, F. Prediction of aerobic and anaerobic capacities of elite cyclists from changes in lactate during isocapnic buffering phase. J Strength Cond Res 29(2): 321-329, 2015-This study predicted aerobic and anaerobic capacities using relative changes of arterial blood lactate during the isocapnic buffering phase (relative [La]ISBP). Fourteen male professional cyclists (sprint-trained [n = 6] and endurance [n = 8]) performed 2 exercise sessions to exhaustion on a cycle ergometer; 1 incremental standard test to determine the isocapnic buffering phase, buffering capacities, and relative [La]ISBP and 1 supramaximal exercise test to determine maximal accumulated oxygen deficit (MAOD). The time between Lactate threshold (LT) and respiratory compensatory threshold (RCT) was considered to be the isocapnic buffering phase. Total buffering capacity was calculated as ?[La]·?pH. Bicarbonate buffering was calculated as ?[HCO3]·?pH, and the difference between -?[La]·?pH and ?[HCO3]·?pH was considered as nonbicarbonate buffering. The lactate concentration for LT (p ? 0.05) and RCT (p ? 0.05), and relative [La]ISBP (p < 0.01) were significantly lower for endurance cyclists than for sprint-trained cyclists. A significant difference was found for bicarbonate buffering capacity between groups (p < 0.01). A significant correlation was found between relative [La]ISBP with (Equation is included in full-text article.)(r = -0.71, p ? 0.05) and MAOD (r = 0.73, p < 0.01). Relative [La]ISBP was useful for predicting aerobic power (R = 51%) and anaerobic capacity (R = 53%). These results demonstrated that relative [La]ISBP is an important variable in intermediary metabolism and in addition to (Equation is included in full-text article.)and LT is recommended for better evaluation of performance of athletes who show nearly equal contributions from the aerobic and anaerobic energy systems during exercise. PMID:25144132

Hasanli, Mohsen; Nikooie, Rohollah; Aveseh, Malihe; Mohammad, Fashi

2015-02-01

141

Bicarbonate/chloride antiport in Vero cells: II. Mechanisms for bicarbonate-dependent regulation of intracellular pH  

SciTech Connect

The rates of bicarbonate-dependent uptake and efflux of /sup 22/Na/sup +/ in Vero cells were studied and compared with the uptake and efflux of /sup 36/Cl/sup -/. Both processes were strongly inhibited by DIDS. Whereas the transport of chloride increased approximately ten-fold when the internal pH was increased over a narrow range around neutrality, the uptake of Na/sup +/ was much less affected by changes in pH. The bicarbonate-linked uptake of /sup 22/Na/sup +/ was dependent on internal Cl- but not on internal Na/sup +/. At a constant external concentration of HCO/sub 3/-, the amount of /sup 22/Na/sup +/ associated with the cells increased when the internal concentration of HCO/sub 3/- decreased and vice versa, which is compatible with the possibility that the ion pair NaCO/sub 3/- is the transported species and that the transport is symmetric across the membrane. Bicarbonate inhibited the uptake of /sup 36/Cl/sup -/ both in the absence and presence of Na/sup +/. At alkaline internal pH, HCO/sub 3/- stimulated the efflux of /sup 36/Cl/sup -/ from preloaded cells, while at acidic internal pH both Na/sup +/ and HCO/sub 3/- were required to induce /sup 36/Cl/sup -/ efflux. We propose a model for how bicarbonate-dependent regulation of the internal pH may occur. This model implies the existence of two bicarbonate transport mechanisms that, under physiological conditions, transport OH(-)-equivalents in opposite directions across the plasma membrane.

Olsnes, S.; Ludt, J.; Tonnessen, T.I.; Sandvig, K.

1987-08-01

142

Anaerobic ammonium oxidation for treatment of ammonium-rich wastewaters*  

PubMed Central

The concept of anaerobic ammonium oxidation (ANAMMOX) is presently of great interest. The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists. Meanwhile, the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters. Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite (CANON) have been developed, and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control. Successful full-scale practice in the Netherlands will accelerate application of the process in future. This review introduces the microbiology and more focuses on application of the ANAMMOX process. PMID:18500782

Zhang, Lei; Zheng, Ping; Tang, Chong-jian; Jin, Ren-cun

2008-01-01

143

Isotonic sodium bicarbonate-triggered emodin release from borate stabilized emodin nanoparticles-loaded polymeric microgel films.  

PubMed

Hydrosoluble emodin-borate (EmB) nanoparticles (NPs) were fabricated by a simple solvent exchange method to address emodin's poor water solubility. As the result, negative charges were introduced in the surface of EmB NPs. In addition, layer-by-layer assembled multilayer films containing cation-rich polymeric microgels (named PAHD) and sodium carboxymethyl cellulose (NaCMC) were employed as drug carrier. Anionic EmB can be loaded into the PAHD/CMC multilayer films. The influences of various experimental parameters on cargo capacity of the PAHD/CMC film were studied in detail. The loaded EmB can be released in the form of emodin molecule in presence of isotonic sodium bicarbonate (ISB) solution. Gratifyingly, EmB did not almost release in presence of water, PBS buffer solution, 0.9% normal saline, and 5% glucose solution. PMID:24755249

Wang, Lin; Wang, Xiaohan; Li, Xiaozhou

2014-07-20

144

Mechanisms of buffer therapy resistance  

PubMed Central

Many studies have shown that the acidity of solid tumors contributes to local invasion and metastasis. Oral pH buffers can specifically neutralize the acidic pH of tumors and reduce the incidence of local invasion and metastatic formation in multiple murine models. However, this effect is not universal as we have previously observed that metastasis is not inhibited by buffers in some tumor models, regardless of buffer used. B16-F10 (murine melanoma), LL/2 (murine lung) and HCT116 (human colon) tumors are resistant to treatment with lysine buffer therapy, whereas metastasis is potently inhibited by lysine buffers in MDA-MB-231 (human breast) and PC3M (human prostate) tumors. In the current work, we confirmed that sensitive cells utilized a pH-dependent mechanism for successful metastasis supported by a highly glycolytic phenotype that acidifies the local tumor microenvironment resulting in morphological changes. In contrast, buffer-resistant cell lines exhibited a pH-independent metastatic mechanism involving constitutive secretion of matrix degrading proteases without elevated glycolysis. These results have identified two distinct mechanisms of experimental metastasis, one of which is pH-dependent (buffer therapy sensitive cells) and one which is pH-independent (buffer therapy resistant cells). Further characterization of these models has potential for therapeutic benefit. PMID:24862761

Bailey, Kate M.; Wojtkowiak, Jonathan W.; Cornnell, Heather H.; Ribeiro, Maria C.; Balagurunathan, Yoganand; Hashim, Arig Ibrahim; Gillies, Robert J.

2014-01-01

145

Memory access buffering in multiprocessors  

Microsoft Academic Search

In highly-pipelined machines, instructions and data are prefetched and buffered in both the processor and the cache. This is done to reduce the average memory access latency and to take advantage of memory interleaving. Lock-up free caches are designed to avoid processor blocking on a cache miss. Write buffers are often included in a pipelined machine to avoid processor waiting

Michel Dubois; Christoph Scheurich; Faye A. Briggs

1986-01-01

146

Sodium bicarbonate reduces postharvest decay development on melons  

Microsoft Academic Search

Sodium bicarbonate (SBC) inhibited in vitro mycelial growth of A. alternata, Fusarium spp. and R. stolonifer. SBC action was fungistatic rather than fungicidal. Coating commercially harvested ‘Galia’ and ‘Ein-Dor’ melons with wax containing 2% SBC reduced decay incidence after storage and shelf life simulation by four to seven-fold, to a commercially acceptable level of 6–7%, compared to untreated or waxed-treated

Y. Aharoni; E. Fallik; A. Copel; M. Gil; S. Grinberg; J. D. Klein

1997-01-01

147

Sodium bicarbonate ingestion improves performance in interval swimming  

Microsoft Academic Search

Summary  In an effort to determine the effects of bicarbonate (NaHCO3) ingestion on exercise performance, ten male college swimmers were studied during five different trials. Each trial consisted of five 91.4m (100-yd) front crawl swims with a two-minute rest interval between each bout. The trials consisted of two NaHCO3 treatments, two placebo trials and one test with no-drink. One hour before

Jiaping Gao; David L. Costill; Craig A. Horswill; Sung H. Park

1988-01-01

148

Bicarbonate dependence of ion current in damaged bone.  

PubMed

The aim of this work was to characterize the ion current that enters mouse metatarsal bones following damage to the cortex. We assessed both the spatial distribution of this current and its dependence on the presence of bicarbonate in the medium. We used a voltage-sensitive probe system vibrating in two dimensions and recorded the signal as function of the position of the probe with respect to the site of damage and of ion substitutions in the medium. When the cortex was damaged (50 microm cylindrical hole penetrating into the marrow cavity), we recorded a steady state net inward electrical current directed toward the site of damage. In nonbicarbonate media, the density of the current was maximal near the center of the hole and ranged from 6 to 18 microA/cm2. As the probe was moved off the center of the hole, measured current density decreased in a manner consistent with the hypothesis that the source of the inward current is localized to the hole. After changing bicarbonate concentration in the medium from 0 to 42 mM, the current density nearly doubled, then decayed back to its original level exponentially over 35 minutes. When the diaphysis of living bone was left intact the current density was close to background level either in the presence or absence of bicarbonate in the medium. Damaged dead bone did not drive any current higher than background level. We conclude that the vibrating probe technique is a powerful tool to characterize ion currents in injured bone, helping to understand the physiology of bone-plasma interface and the bone healing processes. The current density transiently doubled upon addition of bicarbonate, indicating that this ion may carry the electrical current in damaged bone, probably by pump-leak mechanisms operating at the bone-plasma interface. PMID:8661484

Rubinacci, A; De Ponti, A; Shipley, A; Samaja, M; Karplus, E; Jaffe, L F

1996-06-01

149

Ring Buffered Network Bus  

NASA Technical Reports Server (NTRS)

This report describes the research effort to demonstrate the integration of a data sharing technology, Ring Buffered Network Bus, in development by Dryden Flight Research Center, with an engine simulation application, the Java Gas Turbine Simulator, in development at the University of Toledo under a grant from the Glenn Research Center. The objective of this task was to examine the application of the RBNB technologies as a key component in the data sharing, health monitoring and system wide modeling elements of the NASA Aviation Safety Program (AVSP) [Golding, 1997]. System-wide monitoring and modeling of aircraft and air safety systems will require access to all data sources which are relative factors when monitoring or modeling the national airspace such as radar, weather, aircraft performance, engine performance, schedule and planning, airport configuration, flight operations, etc. The data sharing portion of the overall AVSP program is responsible for providing the hardware and software architecture to access and distribute data, including real-time flight operations data, among all of the AVSP elements. The integration of an engine code capable of numerically "flying" through recorded flight paths and weather data using a software tool that allows for distributed access of data to this engine code demonstrates initial steps toward building a system capable of monitoring and modeling the National Airspace.

1997-01-01

150

Sodium bicarbonate treatment extends life of formerly acid lake  

SciTech Connect

For the second time, researchers have used a familiar home remedy to restore the balance of a once acid lake. On September 29, Wolf Pond, in New York's Adirondack State Park, was treated with sodium bicarbonate to adjust alkalinity and keep pH at normal levels at least into the 1990's. Since it was first treated with bicarbonate in 1984, Wolf Pond has recovered and stabilized enough to sustain fish life once again. Repeated dosing is necessary because acid rain and runoff gradually deplete alkalinity in the lake over a period of years. Wolf Pond was selected for study because it has very little outflow and its major source of replenishment is rain. As the 1986 study explained, sodium bicarbonate was chosen for this application because it provides four advantages: (1) it is very soluble; (2) it cannot raise pH above 8.5; (3) it is easy to handle and apply; and (4) it is safe enough to be a common ingredient of many pharmaceuticals and foods.

Not Available

1988-02-01

151

Bicarbonate\\/chloride antiport in Vero cells: II. Mechanisms for bicarbonate-dependent regulation of intracellular pH  

Microsoft Academic Search

The rates of bicarbonate-dependent uptake and efflux of ²²Na\\/sup +\\/ in Vero cells were studied and compared with the uptake and efflux of ³⁶Cl⁻. Both processes were strongly inhibited by DIDS. Whereas the transport of chloride increased approximately ten-fold when the internal pH was increased over a narrow range around neutrality, the uptake of Na\\/sup +\\/ was much less affected

Sjur Olsnes; Jannikke Ludt; T. I. Tonnessen; Kirsten Sandvig

1987-01-01

152

Cyclo­hexyl­ammonium nitrate  

PubMed Central

In the title salt, C6H14N+·NO3 ?, the cyclo­hexyl ring adopts a chair conformation. The ammonium group occupies an equatorial position and the crystal struture is stabilized by inter­molecular N—H?O hydrogen-bonding inter­actions, resulting in a three-dimensional network. PMID:24764971

Bagabas, Abdulaziz A.; Aboud, Mohamed F. A.; Shemsi, Ahsan M.; Addurihem, Emad S.; Al-Othman, Zeid A.; Chidan Kumar, C. S.; Fun, Hoong-Kun

2014-01-01

153

21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2011-04-01

154

21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2010-04-01

155

21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2012-04-01

156

Electrodialysis operation with buffer solution  

DOEpatents

A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.

Hryn, John N. (Naperville, IL); Daniels, Edward J. (Orland Park, IL); Krumdick, Greg K. (Crete, IL)

2009-12-15

157

Extraction of urea and ammonium ion  

NASA Technical Reports Server (NTRS)

Water purification system keeps urea and ammonium ion concentration below toxic limits in recirculated water of closed loop aquatic habitat. Urea is first converted to ammonium ions and carbon dioxide by enzygmatic action. Ammonium ions are removed by ion exchange. Bioburden is controlled by filtration through 0.45 micron millipore filters.

Anselmi, R. T.; Husted, R. R.; Schulz, J. R.

1977-01-01

158

Influence of Heterogeneous Ammonium Availability on Bacterial  

E-print Network

primarily focused on nitrification by ammonium-oxidizing bacteria, the role of nitrate as an electronInfluence of Heterogeneous Ammonium Availability on Bacterial Community Structure and the Expression of Nitrogen Fixation and Ammonium Transporter Genes during in Situ Bioremediation of Uranium

Lovley, Derek

159

Development and evaluation of acid-buffering bioadhesive vaginal tablet for mixed vaginal infections.  

PubMed

An acid-buffering bioadhesive vaginal tablet was developed for the treatment of genitourinary tract infections. From the bioadhesion experiment and release studies it was found that polycarbophil and sodium carboxymethylcellulose is a good combination for an acid-buffering bioadhesive vaginal tablet. Sodium monocitrate was used as a buffering agent to provide acidic pH (4.4), which is an attribute of a healthy vagina. The effervescent mixture (citric acid and sodium bicarbonate) along with a superdisintegrant (Ac-Di-sol) was used to enhance the swellability of the bioadhesive tablet. The drugs clotrimazole (antifungal) and metronidazole (antiprotozoal as well as an antibacterial) were used in the formulation along with Lactobacillus acidophilus spores to treat mixed vaginal infections. From the ex vivo retention study it was found that the bioadhesive polymers hold the tablet for more than 24 hours inside the vaginal tube. The hardness of the acid-buffering bioadhesive vaginal tablet was optimized, at 4 to 5 kg hardness the swelling was found to be good and the cumulative release profile of the developed tablet was matched with a marketed conventional tablet (Infa-V). The in vitro spreadability of the swelled tablet was comparable to the marketed gel. In the in vitro antimicrobial study it was found that the acid-buffering bioadhesive tablet produces better antimicrobial action than marketed intravaginal drug delivery systems (Infa-V, Candid-V and Canesten 1). PMID:18181530

Alam, Mohd Aftab; Ahmad, Farhan Jalees; Khan, Zeenat Iqbal; Khar, Roop Krishen; Ali, Mushir

2007-01-01

160

Effect of a buffering sugar-free lozenge on intraoral pH and electrochemical action.  

PubMed

Two double-blind crossover studies were performed to test a sugar-free lozenge containing bicarbonate and phosphate buffers (Profylin). The studies were performed in groups of 20 and 13 individuals. In Study I active buffering or placebo lozenge (not buffered) was given, and the pH of plaque and saliva was measured after 2, 5, 10, 20, and 30 min. In study II the lozenges were given 10 min after a sucrose rinse, and both the pH and the potential and polarization of amalgam restorations that made contact in the oral cavity were measured. In study I both lozenges increased the pH of plaque and saliva, but the values after sucking on the active lozenge were significantly higher than after placebo. In study II a pH recovery of plaque and saliva after the sucrose rinse was recorded for both types of lozenge, but it was most pronounced for the active, buffering lozenge. A statistically significant difference was, however, found only 5 min after sucking on the lozenge. No influence on the current magnitude was observed. The results thus indicate that the buffering sugar-free lozenge raises the pH of plaque and saliva and accelerates the pH recovery after a sucrose rinse but seems to have no influence on the galvanic current magnitude of amalgam restorations in contact. PMID:1803847

Nilner, K; Vassilakos, N; Birkhed, D

1991-10-01

161

The effect of sodium bicarbonate and sodium citrate ingestion on anaerobic power during intermittent exercise  

Microsoft Academic Search

Summary  The effect of sodium bicarbonate and sodium citrate ingestion on cycling performance in three 30 s Wingate Anaerobic Tests\\u000a separated by 6 min recovery periods has been studied using 6 male subjects. Subjects ingested either sodium bicarbonate (B),\\u000a sodium bicarbonate plus sodium citrate (BC), sodium citrate (C) or sodium chloride (P) 2.5 h prior to exercise in a dose of

M. Parry-Billings; D. P. M. MacLaren

1986-01-01

162

Anion?exchange membrane, water, and sodium bicarbonate extractions as soil tests for phosphorus  

Microsoft Academic Search

Three techniques were evaluated as soil P tests for western Canadian soils: anion?exchange membrane (AEM), water, and bicarbonate extraction. The AEM, water, and bicarbonate?extractable total P represented novel approaches to compare to the widely used bicarbonate?extractable inorganic P (traditional Olsen) soil test. In a range of Saskatchewan soils, similar trends in predicted relative P availability were observed for AEM, water

J. J. Schoenau; W. Z. Huang

1991-01-01

163

Molecular Cloning of a New Sodium Bicarbonate Cotransporter cDNA from Human Retina  

Microsoft Academic Search

Sodium bicarbonate cotransport is an electrogenic process and a principal regulator of pH. A recently cloned sodium bicarbonate cotransporter (NBC1) is predominantly expressed in kidney. The presence of several isoforms is suggested from functional studies. We have cloned a new member of this family from human retina, which was named hNBC2 (for human sodium bicarbonate cotransporter 2). The hNBC2 has

Kenichi Ishibashi; Sei Sasaki; Fumiaki Marumo

1998-01-01

164

49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.  

Code of Federal Regulations, 2012 CFR

...nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

2012-10-01

165

49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.  

Code of Federal Regulations, 2010 CFR

...nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

2010-10-01

166

49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.  

...nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

2014-10-01

167

49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.  

Code of Federal Regulations, 2013 CFR

...nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

2013-10-01

168

49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.  

Code of Federal Regulations, 2011 CFR

...nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 ...nitrates, and certain ammonium nitrate fertilizers. (a) Except as provided in...Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than 70%...

2011-10-01

169

The Potential Role of Systemic Buffers in Reducing Intratumoral Extracellular pH and Acid-Mediated Invasion  

PubMed Central

A number of studies have shown that the extracellular pH (pHe) in cancers is typically lower than that in normal tissue and that an acidic pHe promotes invasive tumor growth in primary and metastatic cancers. Here, we investigate the hypothesis that increased systemic concentrations of pH buffers reduce intratumoral and peritumoral acidosis and, as a result, inhibit malignant growth. Computer simulations are used to quantify the ability of systemic pH buffers to increase the acidic pHe of tumors in vivo and investigate the chemical specifications of an optimal buffer for such purpose. We show that increased serum concentrations of the sodium bicarbonate (NaHCO3) can be achieved by ingesting amounts that have been used in published clinical trials. Furthermore, we find that consequent reduction of tumor acid concentrations significantly reduces tumor growth and invasion without altering the pH of blood or normal tissues. The simulations also show that the critical parameter governing buffer effectiveness is its pKa. This indicates that NaHCO3, with a pKa of 6.1, is not an ideal intratumoral buffer and that greater intratumoral pHe changes could be obtained using a buffer with a pKa of ~7. The simulations support the hypothesis that systemic pH buffers can be used to increase the tumor pHe and inhibit tumor invasion. PMID:19276380

Silva, Ariosto S.; Yunes, Jose A.; Gillies, Robert J.; Gatenby, Robert A.

2013-01-01

170

Regulation and roles of bicarbonate transporters in cancer  

PubMed Central

A unifying feature of solid tumors is a markedly altered pH profile compared to normal tissues. This reflects that solid tumors, despite completely different origins, often share several phenotypic properties with implications for intra- and extracellular pH. These include: a metabolic shift in most cancer cells toward more acid-producing pathways, reflecting both oncogenic signaling and the development of hypoxia in poorly perfused regions of the tumors; the poorly perfused and often highly dense tumor microenvironment, reducing the diffusive flux of acid equivalents compared to that in normal tissues; and the markedly altered regulation of the expression and activity of pH-regulatory transport proteins in cancer cells. While some of these properties of tumors have been well described in recent years, the great majority of the research in this clinically important area has focused on proton transport, in particular via the Na+/H+ exchanger 1 (SLC9A1, NHE1) and various H+ ATPases. We have, however, recently demonstrated that at least under some conditions, including in vitro models of HER2 positive breast cancer, and measurements obtained directly in freshly dissected human mammary carcinomas, bicarbonate transporters such as the electroneutral Na+, HCO?3 cotransporter (SLC4A7, NBCn1), are upregulated and play central roles in pH regulation. In this review, we summarize and discuss the current knowledge regarding the regulation and roles of bicarbonate transporters in cancer. Furthermore, we present new analyses of publicly available expression data demonstrating widely altered expression levels of SLC4- and SLC26 family transporters in breast-, lung-, and colon cancer patients, and we hypothesize that bicarbonate transporter dysregulation may have both diagnostic and therapeutic potential in cancer treatment. PMID:24795638

Gorbatenko, Andrej; Olesen, Christina W.; Boedtkjer, Ebbe; Pedersen, Stine F.

2014-01-01

171

Regulation and roles of bicarbonate transporters in cancer.  

PubMed

A unifying feature of solid tumors is a markedly altered pH profile compared to normal tissues. This reflects that solid tumors, despite completely different origins, often share several phenotypic properties with implications for intra- and extracellular pH. These include: a metabolic shift in most cancer cells toward more acid-producing pathways, reflecting both oncogenic signaling and the development of hypoxia in poorly perfused regions of the tumors; the poorly perfused and often highly dense tumor microenvironment, reducing the diffusive flux of acid equivalents compared to that in normal tissues; and the markedly altered regulation of the expression and activity of pH-regulatory transport proteins in cancer cells. While some of these properties of tumors have been well described in recent years, the great majority of the research in this clinically important area has focused on proton transport, in particular via the Na(+)/H(+) exchanger 1 (SLC9A1, NHE1) and various H(+) ATPases. We have, however, recently demonstrated that at least under some conditions, including in vitro models of HER2 positive breast cancer, and measurements obtained directly in freshly dissected human mammary carcinomas, bicarbonate transporters such as the electroneutral Na(+), HCO(-) 3 cotransporter (SLC4A7, NBCn1), are upregulated and play central roles in pH regulation. In this review, we summarize and discuss the current knowledge regarding the regulation and roles of bicarbonate transporters in cancer. Furthermore, we present new analyses of publicly available expression data demonstrating widely altered expression levels of SLC4- and SLC26 family transporters in breast-, lung-, and colon cancer patients, and we hypothesize that bicarbonate transporter dysregulation may have both diagnostic and therapeutic potential in cancer treatment. PMID:24795638

Gorbatenko, Andrej; Olesen, Christina W; Boedtkjer, Ebbe; Pedersen, Stine F

2014-01-01

172

Iron Oxide Removal from Soils and Clays by a Dithionite-Citrate System Buffered with Sodium Bicarbonate  

Microsoft Academic Search

The oxidation potential of dithionite (Na~S204) increases from 0.37 V to 0.73 V with increase in pH from 6 to 9, because hydroxyl is consumed during oxidation of dithionite. At tile same time the amount of iron oxide dissolved in 15 minutes falls off (from 100 percent to less than 1 percent extracted) with increase in pH from 6 to

O. P. MEdinA; M. L. JACKSO

1958-01-01

173

Hemodialysis for extracorporeal bicarbonate/CO2 removal (ECBicCO2R) and apneic oxygenation for respiratory failure in the newborn. Theory and preliminary results in animal experiments.  

PubMed

Extracorporeal techniques for respiratory support in the newborn are feasible, as the growth of neonatal extracorporeal membrane oxygenation (ECMO) has demonstrated. It has been shown, however, that even in severely damaged lungs, sufficient oxygenation and gas exchange can be maintained only by removing CO2 in an extracorporeal circuit, i.e., extracorporeal CO2 removal (ECCO2R). To demonstrate the effectiveness of CO2 removal in a bicarbonate-free hemodialysis procedure, CO2 removal was measured during routine acetate hemodialysis in 22 patients on renal replacement therapy for end-stage renal disease. By comparison of predialyzer and postdialyzer total CO2, an overall CO2 removal of 79.1 +/- 15.1 ml/min was measured in the blood and 77.0 +/- 19.5 ml/min in the dialysate; this was approximately one third of the entire metabolic CO2 production and probably accounted for the secondary hypoxia during acetate hemodialysis. To use bicarbonate-free hemodialysis for total metabolic CO2 removal, acetate dialysate was modified with lactate, phosphate buffer, and sodium hydroxide to compensate for the bicarbonate loss. In sheep, apneic oxygenation could be achieved with blood flow rates as low as 10-15 ml/kg/min for 4-6 hours. These preliminary data suggest that a hemodialysis procedure for bicarbonate and CO2 elimination (ECBicCO2R) could be an efficient method for CO2 removal requiring much lower blood flow rates than techniques presently in use. PMID:2499349

Nolte, S H; Jonitz, W J; Grau, J; Roth, H; Assenbaum, E R

1989-01-01

174

Triethyl­ammonium hydrogen chloranilate  

PubMed Central

In the crystal structure of the title compound (systematic name: triethyl­ammonium 2,5-dichloro-4-hy­droxy-3,6-dioxo­cyclo­hexa-1,4-dien-1-olate), C6H16N+·C6HCl2O4 ?, two hydrogen chloranilate anions are connected by a pair of bifurcated O—H?O hydrogen bonds into a dimeric unit. The triethyl­ammonium cations are linked on both sides of the dimer via bifurcated N—H?O hydrogen bonds into a centrosymmetric 2:2 aggregate. The 2:2 aggregates are further linked by inter­molecular C—H?O hydrogen bonds. PMID:21589539

Gotoh, Kazuma; Maruyama, Shinpei; Ishida, Hiroyuki

2010-01-01

175

Manganese complexes with bicarbonate and sulfate in natural water  

USGS Publications Warehouse

The association constant for the dissolved species MnHCO3+ was experimentally determined to be 63. From this value and a published constant for the species MNSO4 aq., a diagram was prepared showing per cent of dissolved manganese complexed in the presence of 10 to 10,000 p.p.m. bicarbonate and 1.0 to 10,000 p.p.m. sulfate. The rate of oxidation of Mn+2 in aerated water is greatly increased by increasing pH, and is retarded when SO4-2and HCO3- are present.

Hem, J.D.

1963-01-01

176

Effects of Oral Sodium Bicarbonate in Patients with CKD  

PubMed Central

Summary Background and objectives Metabolic acidosis contributes to muscle breakdown in patients with CKD, but whether its treatment improves functional outcomes is unknown. The choice of dose and tolerability of high doses remain unclear. In CKD patients with mild acidosis, this study evaluated the dose–response relationship of alkali with serum bicarbonate, its side effect profile, and its effect on muscle strength. Design, setting, participants, & measurements In this single-blinded pilot study from March of 2009 to August of 2010, 20 adults with estimated GFR 15–45 ml/min per 1.73 m2 and serum bicarbonate 20–24 mEq/L were treated during successive 2-week periods with placebo followed by escalating oral NaHCO3 doses (0.3, 0.6, and 1.0 mEq/kg per day). At each visit, handgrip strength and time required to complete 5 and 10 repetitions of a sit-to-stand test were measured. Results Each 0.1 mEq/kg per day increase in dose produced a 0.33 mEq/L (95% confidence interval=0.23–0.43 mEq/L) higher serum bicarbonate. Sit-to-stand time improved after 6 weeks of oral NaHCO3 (23.8±1.4 versus 22.2±1.6 seconds for 10 repetitions, P=0.002), and urinary nitrogen excretion decreased (?0.70 g/g creatinine [95% confidence interval=?1.11 to ?0.30] per 0.1 mEq/kg per day higher dose). No statistically significant change was seen in handgrip strength (29.5±9.6 versus 28.4±9.4 kg, P=0.12). Higher NaHCO3 doses were not associated with increased BP or greater edema. Conclusions NaHCO3 supplementation produces a dose-dependent increase in serum bicarbonate and improves lower extremity muscle strength after a short-term intervention in CKD patients with mild acidosis. Long-term studies are needed to determine if this finding translates into improved functional status. PMID:23393105

Melamed, Michal L.; Bauer, Carolyn; Raff, Amanda C.; Hostetter, Thomas H.

2013-01-01

177

Free flow cell electrophoresis using zwitterionic buffer  

NASA Technical Reports Server (NTRS)

Studies of a zwitterionic buffer formulated for cell electrophoresis were done using the McDonnell-Douglas Continuous Flow Electrophoresis System. Standard buffers were analyzed for their stability in the electrical field and the results showed that both buffers tested were inherently unstable. Further, titration studies showed that the standards buffers buffered poorly at the pH employed for electrophoresis. The zwitterionic buffer buffered well at its nominal pH and was shown to be stable in the electrical field. Comparative studies of the buffer with standard cell separation buffers using formalin fixed rabbit and goose red blood cells showed that the zwitterionic buffer gave better resolution of the fixed cells. Studies with viable hybridoma cells showed that buffer Q supported cell viability equal to Hank's Balanced Salt Solution and that hybridoma cells in different stages of the growth cycle demonstrated reproducible differences in electrophoretic mobility.

Rodkey, R. Scott

1990-01-01

178

Buffer Gas Acquisition and Storage  

NASA Technical Reports Server (NTRS)

The acquisition and storage of buffer gases (primarily argon and nitrogen) from the Mars atmosphere provides a valuable resource for blanketing and pressurizing fuel tanks and as a buffer gas for breathing air for manned missions. During the acquisition of carbon dioxide (CO2), whether by sorption bed or cryo-freezer, the accompanying buffer gases build up in the carbon dioxide acquisition system, reduce the flow of CO2 to the bed, and lower system efficiency. It is this build up of buffer gases that provide a convenient source, which must be removed, for efficient capture Of CO2 Removal of this buffer gas barrier greatly improves the charging rate of the CO2 acquisition bed and, thereby, maintains the fuel production rates required for a successful mission. Consequently, the acquisition, purification, and storage of these buffer gases are important goals of ISRU plans. Purity of the buffer gases is a concern e.g., if the CO, freezer operates at 140 K, the composition of the inert gas would be approximately 21 percent CO2, 50 percent nitrogen, and 29 percent argon. Although there are several approaches that could be used, this effort focused on a hollow-fiber membrane (HFM) separation method. This study measured the permeation rates of CO2, nitrogen (ND, and argon (Ar) through a multiple-membrane system and the individual membranes from room temperature to 193K and 10 kpa to 300 kPa. Concentrations were measured with a gas chromatograph that used a thermoconductivity (TCD) detector with helium (He) as the carrier gas. The general trend as the temperature was lowered was for the membranes to become more selective, In addition, the relative permeation rates between the three gases changed with temperature. The end result was to provide design parameters that could be used to separate CO2 from N2 and Ar.

Parrish, Clyde F.; Lueck, Dale E.; Jennings, Paul A.; Callahan, Richard A.; Delgado, H. (Technical Monitor)

2001-01-01

179

ZnS/Zn(O,OH)S-based buffer layer deposition for solar cells  

DOEpatents

The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.

Bhattacharya, Raghu N. (Littleton, CO)

2009-11-03

180

Neurogenic regulation of proximal bicarbonate and chloride reabsorption.  

PubMed

Although a change in renal nerve activity is known to alter proximal reabsorption, it is unclear whether reabsorption of NaHCO3 or NaCl or both are affected. Sprague-Dawley rats (n = 10) were studied using free-flow micropuncture techniques during euvolemia and following acute ipsilateral denervation. Glomerular filtration rate and single nephron glomerular filtration rate were stable. Absolute proximal bicarbonate reabsorption fell following denervation (933 +/- 40 to 817 +/- 30 pmol/min) with a parallel reduction in chloride reabsorption (1,643 +/- 116 to 1,341 +/- 129 peq/min). Urinary sodium, potassium, bicarbonate, and chloride excretion all increased significantly. To further assess the physiological significance of neurogenic modulation of proximal transport, other rats (n = 6) were subjected to acute unilateral nephrectomy (AUN). There is evidence that AUN induces a contralateral natriuresis (renorenal reflex) at least partially by causing inhibition of efferent renal nerve traffic. AUN caused significant changes in proximal NaHCO3 and NaCl reabsorption as well as in whole kidney electrolyte excretion in the same pattern as had denervation. Prior denervation of the remaining kidney prevented the proximal and whole kidney response to AUN (n = 6). In conclusion, depression of renal nerve activity inhibits both NaHCO3 and NaCl reabsorption in the rat superficial proximal convoluted tubule. The data are consistent with the hypothesis that changes in renal nerve activity modify whole kidney electrolyte excretion under physiological conditions at least partially by regulating proximal transport. PMID:3942224

Cogan, M G

1986-01-01

181

Conductance Regulator Bicarbonate Conductance and pH Regulatory Capability of Cystic Fibrosis Transmembrane  

E-print Network

Conductance Regulator Bicarbonate Conductance and pH Regulatory Capability of Cystic Fibrosis Bicarbonate conductance and pH regulatory capability of cystic fibrosis transmembrane conductance regulator J0 of California, Berkeley, CA 94720 Communicated by Hans H. Ussing, February 28, 1994 ABSTRACT The cystic fibrosis

Machen, Terry E.

182

SODIUM BENTONITE OR SODIUM BICARBONATE AS AIDS IN FEEDING HIGH-CONCENTRATE DIETS TO LAMBS 1  

Microsoft Academic Search

SUMMARY Studies were conducted to compare bento- nite and sodium bicarbonate as dietary aids in adaptation and subsequent performance of lambs fed high-concentrate diets under various conditions of protein supplementation. Three protein variations, including no supplemental protein (NSP), soybean meal (SBM) or urea, were factored with a control, 2% or 4% sodium bentonite, and 2% or 4% sodium bicarbonate in

G. B. Huntington; R. J. Emerick; L. B. Embry

2010-01-01

183

High sodium bicarbonate and acetate hemodialysis: Double-blind crossover comparison of hemodynamic and ventilatory effects  

Microsoft Academic Search

High sodium bicarbonate and acetate hemodialysis: Double-blind crossover comparison of hemodynamic and ventilatory effects. The superiority of bicarbonate dialysis (Bi HD) over acetate dialysis (Ac HD) using a high sodium dialysate has not been established to our knowledge. We compared Bi HD to Ac HD over 6 weeks each in ten stable patients using a double-blind crossover design and a

William L Henrich; Terry D Woodard; Barry D Meyer; Timothy R Chappell; Lewis J Rubin

1983-01-01

184

Approach to the hemodialysis patient with an abnormal serum bicarbonate concentration.  

PubMed

We present a patient receiving hemodialysis with a persistently high serum bicarbonate concentration to illustrate the evaluation and management issues for patients with both high (>25 mEq/L) and low (<20 mEq/L) pretreatment values. Patients with high serum bicarbonate concentrations typically are malnourished and have low rates of endogenous acid production. Evaluation should begin with assessment of whether an acute and potentially reversible cause of metabolic alkalosis is present. If not, management should be directed at treating malnutrition. By contrast, patients with low predialysis serum bicarbonate concentrations, in the absence of an acute and reversible cause, may benefit from increasing the level by an adjustment in dialysate bicarbonate concentration. However, the level at which one should intervene and to what extent serum bicarbonate concentration should be increased are unresolved issues. Whether such an intervention will reduce mortality risk has not been determined. PMID:24731739

Lisawat, Panupong; Gennari, F John

2014-07-01

185

Influence of bicarbonate ions on the deterioration of mortar bars in sulfate solutions  

SciTech Connect

This work investigates the influence of bicarbonate ions on the deterioration of cementitious material exposed to sulfate ions. Mortars based on a CEM I and on a CEM III/B cement were investigated. Experimental investigations were compared to thermodynamic modeling and phase characterization to understand the differences in deterioration. The presence of bicarbonate ions significantly reduced the expansion of the CEM I mortars. Thermodynamic modeling showed that at high concentrations of bicarbonate ettringite and gypsum become unstable. Microstructural characterization combined with information from thermodynamic modeling suggests that conditions of high supersaturation with respect to ettringite are unlikely in the samples exposed in solutions containing bicarbonate. Consequently, expansive forces are not generated by the crystallization pressure of ettringite. There was little expansion of the CEM III/B sample even in the sodium sulfate solution. In the bicarbonate solution this mortar showed a highly leached zone at the surface in which calcite was observed.

Kunther, W., E-mail: Wolfgang.Kunther@empa.ch [Empa, Laboratory for Concrete and Construction Chemistry, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Lothenbach, B. [Empa, Laboratory for Concrete and Construction Chemistry, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)] [Empa, Laboratory for Concrete and Construction Chemistry, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Scrivener, K. [EPFL, Laboratory of Construction Materials, CH-1015 Lausanne (Switzerland)] [EPFL, Laboratory of Construction Materials, CH-1015 Lausanne (Switzerland)

2013-02-15

186

Stimulation of amphibian gastroduodenal bicarbonate secretion by sucralfate and aluminium: role of local prostaglandin metabolism.  

PubMed Central

The present studies were designed to explore the possible mode of protective and ulcer healing actions of sucralfate by examining its effect on gastroduodenal bicarbonate secretion by isolated amphibian mucosa. Luminal sucralfate (0.5 g/l) significantly increased bicarbonate secretion by fundic and antral mucosa without influencing transmucosal potential difference. Significant stimulation of duodenal bicarbonate secretion occurred only at 1.0 g/l without change in potential difference. Aluminium, a component of sucralfate, produced similar increases in bicarbonate secretion, while the sucrose and sulphate components were without effect. Pretreatment of mucosae with the cyclooxygenase inhibitor, indomethacin (10 5M) did not abolish the secretory response to sucralfate or aluminium. The results suggest that stimulation of gastroduodenal bicarbonate secretion, possibly by the aluminium moiety of sucralfate, may play a role in its protective and ulcer healing actions. PMID:3260886

Crampton, J R; Gibbons, L C; Rees, W D

1988-01-01

187

Decline of acid-sensitive plant species in heathland can be attributed to ammonium toxicity in combination with low pH.  

PubMed

The effects of increasing ammonium concentrations in combination with different pH levels were studied on five heathland plant species to determine whether their occurrence and decline could be attributed to ammonium toxicity and/or pH levels. Plants were grown in growth media amended with four different ammonium concentrations (10, 100, 500 and 1000 micromol l(-1)) and two pH levels resembling acidified (pH 3.5 or 4) and weakly buffered (pH 5 or 5.5) situations. Survival of Antennaria dioica and Succisa pratensis was reduced by low pH in combination with high ammonium concentrations. Biomass decreased with increased ammonium concentrations and decreasing pH levels. Internal pH of the plants decreased with increasing ammonium concentrations. Survival of Calluna vulgaris, Deschampsia flexuosa and Gentiana pneumonanthe was not affected by ammonium. Moreover, biomass increased with increasing ammonium concentrations. Biomass production of G. pneumonanthe reduced at low pH levels. A decline of acid-sensitive species in heathlands was attributed to ammonium toxicity effects in combination with a low pH. PMID:15819917

van den Berg, Leon J L; Dorland, Edu; Vergeer, Philippine; Hart, Miron A C; Bobbink, Roland; Roelofs, Jan G M

2005-05-01

188

Statistical evaluation of effects of riparian buffers on nitrate and ground water quality  

USGS Publications Warehouse

A study was conducted to statistically evaluate the effectiveness of riparian buffers for decreasing nitrate concentrations in ground water and for affecting other chemical constituents. Values for pH, specific conductance, alkalinity, dissolved organic carbon (DOC), silica, ammonium, phosphorus, iron, and manganese at 28 sites in the Contentnea Creek Basin were significantly higher (p 20 yr) discharging ground water draining areas with riparian buffers compared with areas without riparian buffers. No differences in chloride, nitrate nitrogen, calcium, sodium, and dssolved oxygen concentrations in old ground water between buffer and nonbuffer areas were detected. Comparison of samples of young (20 yr) discharging ground water draining areas with riparian buffers compared with areas without riparian buffers. No differences in chloride, nitrate nitrogen, calcium, sodium, and dissolved oxygen concentrations in old ground water between buffer and nonbuffer areas were detected. Comparison of samples of young (<20 yr) discharging ground water samples from buffer and nonbuffer areas indicated significantly higher specific conductance, calcium, chloride, and nitrate nitrogen in nonbuffer areas. Riparian buffers along streams can affect the composition of the hyporheic zone by providing a source of organic carbon to the streambed, which creates reducing geochemical conditions that consequently can affect the chemical quality of old ground water discharging through it. Buffer zones between agricultural fields and streams facilitate dilution of conservative chemical constituents in young ground water that originate from fertilizer applications and also allow denitrification in ground water by providing an adequate source of organic carbon generated by vegetation in the buffer zone. Based on the median chloride and nitrate values for young ground water in the Contentnea Creek Basin, nitrate was 95% lower in buffer areas compared with nonbuffer areas, with a 30 to 35% reduction estimated to be due to dilution and 65 to 70% due to reduction and/or denitrification.Using data derived from a study area located in the Contentnea Creek Drainage Basin in North Carolina, the presence of riparian buffers 30-m wide or more and composed of lowland hardwood vegetation was assessed statistically in terms of nitrate-nitrogen concentrations in discharging groundwater passing beneath the buffers. The groundwater and surface-water sampling sites were selected by overlaying a digital coverage of a ma

Spruill, T.B.

2000-01-01

189

Physiological aspects of ammonium and nitrate fertilization  

Microsoft Academic Search

Various physiological effects of ammonium, nitrate and mixed ammonium?nitrate nutrition of plants have been studied in this laboratory during the last years. Some of the characteristic distinctions observed between plants growing on these nitrogen sources are described and discussed. Biomass production of ammonium?grown plants increased with K concentration in the nutrient medium between 0.1 to 3 mM , while nitrate?fed

S. H. Lips; E. O. Leidi; M. Silberbush; M. I. M. Soares; O. E. M. Lewis

1990-01-01

190

Sodium bicarbonate in chemical flooding. Project OE6. [Viscosities of chemical slugs  

SciTech Connect

In this report we are presenting the results of our investigation in 3 areas: (1) the use of low pH alkaline chemicals for wettability alteration; (2) the development of a correlation between interfacial shear viscosity and water breakout for oil-brine macroemulsions; and (3) the evaluation of bicarbonate as a chemical for use in oil recovery. The main objective of our work is to develop an understanding of the mechanisms involved in bicarbonate flooding and to make specific recommendations for its potential use in enhanced oil recovery. To evaluate the use of bicarbonate as an emulsion destabilizer, emulsification and coalescence test results were compared with interfacial shear viscosities. In two of the three systems studied an inverse relationship was found between the maximum rate of water breakout and interfacial shear viscosity. Temperature and aging of the interface was a major factor affecting these results. Sodium bicarbonate and sodium carbonate were used to determine their effect on rock wettability. Sodium bicarbonate was found to change the wettability of Berea sandstone toward the water-wet state more effectively than sodium carbonate for the low acid oil, Noone crude. Highly acidic crude oils appeared to react with bicarbonate creating highly absorbed surfactants. This caused Berea sandstone to become more oil-wet. The major mechanisms of oil recovery using sodium bicarbonate include wettability alteration, emulsification followed by coalescence, and lowered interfacial shear viscosity. These mechanisms alone did not cause significant recovery of the low acid oil, Noone crude. Previous oil displacement tests indicate that bicarbonate is more effective when using acidic crude oils. The range of oils that can be recovered using bicarbonate can be extended by adding small amounts of surfactants to the bicarbonate slug. 18 refs., 3 figs., 6 tabs.

Peru, D.A.

1986-05-01

191

Chloride-bicarbonate exchange in human red cells measured using a stopped flow apparatus.  

PubMed Central

1. A new stopped-flow apparatus has been used to measure the exchange of intracellular chloride and extracellular bicarbonate across the human erythrocyte membrane at 37 degrees C. 2. The concentration dependence of the activation of the anion exchange system by extracellular bicarbonate was consistent with the existence of a saturable membrane-carrier. Analysis of the results assuming Michaelis--Menten kinetics indicated a Vmax for chloride--bicarbonate exchange of 73 . 4 +/- 14 . 4 mol. (3 x 10(13) cells.min)-1 and Km for bicarbonate of 11 . 1 +/- 2 . 8 mM at 37 degrees C (pH 7 . 1). 3. Correction of the directly computed values of Vmax for incomplete saturation of the carrier by intracellular chloride and the inhibitory effects of intracellular bicarbonate and extracellular chloride gave a Vmax of 157 +/- 43 . 8 mol (3 x 10(13) cells.min)-1 and a Km of 15 . 5 +/- 5 . 2 mM-bicarbonate at 37 degrees C. 4. Comparison of Vmax obtained at 37 and 10 degrees C indicates that the activation energy for chloride--bicarbonate exchange in this temperature range is 18 . 7 --19 . 6 kcal.mol-1 depending on whether corrected or uncorrected values are used. 5. Extracellular furosemide inhibited chloride--bicarbonate exchange with a KI of 0 . 12 microM assuming competition between furosemide and bicarbonate and 0 . 17 microM assuming non-competitive inhibition. 6. Extracellular chloride also inhibited chloride--bicarbonate exchange but the kinetics of inhibition were complex. PMID:7463368

Lambert, A; Lowe, A G

1980-01-01

192

75 FR 55991 - Ammonium Formate; Exemption from the Requirement of a Tolerance  

Federal Register 2010, 2011, 2012, 2013

...Ammonium formate breaks down into ammonium and formate ions. Ammonium ions are a toxic waste product of the metabolism in animals...Ammonium formate breaks down into ammonium and formate ions. Ammonium ions are ubiquitous in the natural...

2010-09-15

193

Ammonium assmilation in spruce ectomycorrhizas  

SciTech Connect

Assimilation of labelled NH{sub 4}{sup +} into amino acids has been followed in ectomycorrhizal roots of spruce. Over an 18 h period of NH{sub 4}{sup +} feeding, Gln, Glu and Ala became the most abundant amino acids. Gln was also the most highly labelled amino acid during the experiment, followed by Glu and Ala. This result indicates that Gln synthesis is an important ammonium utilization reaction in spruce mycorrhizas. Addition of MSX to NH{sub 4}{sup +} fed mycorrhizas caused an inhibition of Gln accumulation with a corresponding increase in Glu, Ala and Asn levels. The supply of MSX induced a sharp diminution of {sup 15}N enrichment in both amino and amido groups of glutamine. In contrast, the {sup 15}N incorporation into Glu and derivatives (Ala and Asp) remained very high. This study demonstrates that the fungal glutamate dehydrogenase is quite operative in spruce ectomycorrhizas since it is able to sustain ammonium assimilation when glutamine synthetase is inhibited.

Chalot, M.; Brun, A.; Botton, B. (Univ. of nancy, Vandoeuvre-les-Nancy (France)); Stewart, G. (University College, London (England))

1990-05-01

194

Structural study of ammonium metatungstate  

SciTech Connect

Several techniques have been used to study the structure of the Keggin-type polyoxometalate salt ammonium metatungstate (AMT)-(NH{sub 4}){sub 6}[H{sub 2}W{sub 12}O{sub 40}]*nH{sub 2}O, a potential fuel cell catalyst. The dehydrated salt is comprised of a mixture of crystallites of different unit cells in a centered eutactic cubic configuration, with an average unit cell of a{approx_equal}12.295. Varied orientations of the Keggin ions in the cubic arrangement create the differences, and orientational variation within each unit cell size represents an energy well. Progressive hydration of each crystallite leads to expansion of the lattice, with the degree of expansion depending on the locations of the water added in relation to the Keggin ion, which is influenced by cation location and hydrogen bonding. The structural hypothesis is supported by electron diffraction of single and multicrystal samples, by powder density measurements, X-ray powder diffraction studies, synchrotron powder X-ray diffraction, and a priori structural modeling studies. Based on the structure, projected active site densities are compared with nanostructured platinum catalysts for fuel cell application. - Graphical abstract: The structure of ammonium metatungstate powders are highly dependent on hydration and POM molecule rotation, with cation and hydrogen bonding forces directing a mixture of structures that have been studied with bulk and single-crystal methods. The illustration shows Monte Carlo simulated anion structural disorder for the fully dehydrated form of the title compound.

Christian, Joel B. [OSRAM SYLVANIA Global Tungsten and Powders, Towanda, PA 18848 (United States); SUNY at Binghamton, Materials Science Program, Binghamton, NY 13902 (United States)], E-mail: joel.christian@sylvania.com; Whittingham, M. Stanley [SUNY at Binghamton, Materials Science Program, Binghamton, NY 13902 (United States)

2008-08-15

195

Mitral and mitro-aortic valve replacement with Sorin Bicarbon valves compared with St. Jude Medical valves  

Microsoft Academic Search

Objective: We assessed the clinical results of two bileaflet mechanical valves: the St. Jude Medical (SJM) and the Sorin Bicarbon (Sorin Bicarbon) used either in single mitral valve replacement (MVR) or in double, aortic and mitral, valve replacement (DVR).Methods: Between September 1990 and November 1995, 217 patients received either a St. Jude Medical (n=134) or a Sorin Bicarbon (n=86): 136

L. F Camilleri; P Bailly; B. J Legault; B Miguel; M.-C D'Agrosa-Boiteux; C. M de Riberolles

2001-01-01

196

The origin of high bicarbonate and fluoride concentrations in waters of the Main Ethiopian Rift Valley, East African Rift system  

Microsoft Academic Search

Thermal waters in the Main Ethiopian Rift Valley are characterized by high Na, bicarbonate and fluoride concentrations, and near-neutral to alkaline pH. Sodium, bicarbonate and fluoride are positively correlated in the waters. The principal reason for the bicarbonate in the area is the high rate of carbon dioxide outgassing. This, combined with acid volcanics, geothermal heating, low Ca and low

Berhanu Gizaw

1996-01-01

197

The origin of high sodium bicarbonate waters in the Atlantic and Gulf Coastal Plains  

USGS Publications Warehouse

Some sodium bicarbonate waters at depth in the Atlantic and Gulf Coastal Plains have the same bicarbonate content as the shallower calcium bicarbonate waters in the same formation and appear to be the result of replacement of calcium by sodium through the action of base-exchange minerals. Others, however, contain several hundred parts per million more of bicarbonate than any of the calcium bicarbonate waters and much more bicarbonate than can be attributed to solution of calcium carbonate through the action of carbon dioxide derived from the air and soil. As the waters in the Potomac group (Cretaceous) are all low in sulphate and as the environmental conditions under which the sediments of the Potomac group were deposited do not indicate that large amounts of sulphate are available for solution, it does not seem probable that carbon dioxide generated by chemical or biochemical breakdown of sulphate is responsible for the high sodium bicarbonate waters in this area. Sulphate as a source of oxygen is not necessary for the generation of carbon dioxide by carbonaceous material. Oxygen is an important constituent of carbonaceous material and carbon dioxide is a characteristic decomposition product of such material-as, for example, peat and lignite. Experimental work showed that distilled water, calcium bicarbonate water, and sodium bicarbonate water, after contact with lignite, calcium carbonate, and permutite (a base-exchange material), had all increased greatly in sodium bicarbonate content and had become similar in chemical character and in mineral content to high sodium bicarbonate waters found in the Coastal Plain. The tests indicated that carbonaceous material can act as a source of carbon dioxide, which, when dissolved in water, enables it to take into solution more calcium carbonate. If base-exchange materials are also present to replace calcium with sodium, a still greater amount of bicarbonate can be held in solution. The presence of carbonaceous material, together with calcium carbonate and base-exchange minerals in a formation is, therefore, sufficient to account for the occurrence in it of high sodium bicarbonate waters. ?? 1950.

Foster, M.D.

1950-01-01

198

SOW STERIOTYPIC BEHAVIOUR IN RELATION TO DIETARY SODIUM BICARBONATE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Stereotypies performed by confined sows have been implicated as indicating poor welfare. There is evidence in horses that oral stereotypies serve to buffer pH and reduce gastric ulceration. Gastric ulceration is prevalent in sows and a weak link with stereotypies has been established. The objective ...

199

Supercritical water oxidation of ammonium picrate  

Microsoft Academic Search

This study demonstrates the feasibility of using supercritical water oxidation to destroy ammonium picrate. Analyses of reactor effluent composition at various temperatures, residence times, and oxidant concentrations were used to design an improved reactor configuration for achieving destruction with minimum corrosion. The engineering evaluation reactor, a room-sized laboratory scale reactor, was reconfigured to incorporate this design change. Destruction of ammonium

C. A. LaJeunesse; B. E. Mills; B. G. Brown

1994-01-01

200

21 CFR 558.340 - Maduramicin ammonium.  

Code of Federal Regulations, 2010 CFR

... 6 2010-04-01 2010-04-01 false Maduramicin ammonium. 558.340 Section 558.340 Food and Drugs FOOD...Animal Drugs for Use in Animal Feeds § 558.340 Maduramicin ammonium. (a) Approvals. Type A medicated articles:...

2010-04-01

201

Ammonium nonanoate broadcast application over onions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ammonium nonanoate occurs in nature and is primarily formed from biodegradation of higher fatty acids. Racer (40% ammonium nonaoate) is a potential contact herbicide for weed control in organic crop production. Field research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determin...

202

Biodegradation of rocket propellant waste, ammonium perchlorate  

NASA Technical Reports Server (NTRS)

The short term effects of ammonium perchlorate on selected organisms were studied. A long term experiment was also designed to assess the changes incurred by ammonium perchlorate on the nitrogen and chloride contents of soil within a period of 3 years. In addition, an attempt was made to produce methane gas from anaerobic fermentation of the aquatic weed, Alternanthera philoxeroides.

Naqvi, S. M. Z.; Latif, A.

1975-01-01

203

Winter Wheat Fertilization: Post Ammonium Nitrate  

Microsoft Academic Search

Summary The potential for overwinter losses of nitrogen by denitrification and leaching have led to the recommendation that nitrogen fertilization of winter wheat be done using ammonium nitrate broadcast in the spring. However, spring broadcast application of urea can result in significant loss of nitrogen by volatilization and immobilization by surface residues. Since prilled ammonium nitrate is not available for

R. Byron Irvine; Guy Lafond; Randy Kutcher

204

Quaternary Ammonium Compounds as Water Channel Blockers  

E-print Network

, West Mains Road, EH9 3JJ Scotland, United Kingdom Excessive water uptake through Aquaporins (AQP) canQuaternary Ammonium Compounds as Water Channel Blockers SPECIFICITY, POTENCY, AND SITE OF ACTION, potency, and binding site of tetraethyl- ammonium (TEA) to block Aquaporin water permeability. Using

de Groot, Bert

205

Dietary Acid, Age, and Serum Bicarbonate Levels among Adults in the United States  

PubMed Central

Summary Background and objectives Greater dietary acid has been associated with lower serum bicarbonate levels in patients with CKD. Whether this association extends to the general population and if it is modified by age are unknown. Design, setting, participants, & measurements This study examined the association of the dietary acid load, estimated by net endogenous acid production, with serum bicarbonate levels in adult participants in the National Health and Nutrition Examination Survey 1999–2004. Results The mean serum bicarbonate was 24.9 mEq/L (SEM=0.1), and the mean estimated net endogenous acid production was 57.4 mEq/d (SEM=0.4). Serum bicarbonate was linearly associated with age, such that the oldest participants had the highest serum bicarbonate levels. After multivariable adjustment, participants in the highest quartile of net endogenous acid production had 0.40 mEq/L (95% confidence interval, ?0.55 to ?0.26) lower serum bicarbonate and a 33% (95% confidence interval, 3 to 72) higher likelihood of acidosis compared with those participants in the lowest quartile. There was a significant interaction by age of the association of net endogenous acid production with serum bicarbonate (P=0.005). Among participants 20–39, 40–59, and ?60 years old, those participants in the highest net endogenous acid production quartile had 0.26 (95% confidence interval, ?0.49 to ?0.03), 0.60 (95% confidence interval, ?0.92 to ?0.29), and 0.49 (95% confidence interval, ?0.84 to ?0.14) mEq/L lower serum bicarbonate, respectively, compared with participants in the lowest quartile. Conclusion Greater dietary acid is associated with lower serum bicarbonate in the general US population, and the magnitude of this association is greater among middle-aged and elderly persons than younger adults. PMID:24052219

Amodu, Afolarin

2013-01-01

206

Bicarbonate impact on U(VI) bioreduction in a shallow alluvial aquifer  

NASA Astrophysics Data System (ADS)

Field-scale biostimulation and desorption tracer experiments conducted in a uranium (U) contaminated, shallow alluvial aquifer have provided insight into the coupling of microbiology, biogeochemistry, and hydrogeology that control U mobility in the subsurface. Initial experiments successfully tested the concept that Fe-reducing bacteria such as Geobacter sp. could enzymatically reduce soluble U(VI) to insoluble U(IV) during in situ electron donor amendment (Anderson et al., 2003; Williams et al., 2011). In parallel, in situ desorption tracer tests using bicarbonate amendment demonstrated rate-limited U(VI) desorption (Fox et al., 2012). These results and prior laboratory studies underscored the importance of enzymatic U(VI)-reduction and suggested the ability to combine desorption and bioreduction of U(VI). Here we report the results of a new field experiment in which bicarbonate-promoted uranium desorption and acetate amendment were combined and compared to an acetate amendment-only experiment in the same experimental plot. Results confirm that bicarbonate amendment to alluvial aquifer sediments desorbs U(VI) and increases the abundance of Ca-uranyl-carbonato complexes. At the same time, the rate of acetate-promoted enzymatic U(VI) reduction was greater in the presence of added bicarbonate in spite of the increased dominance of Ca-uranyl-carbonato aqueous complexes. A model-simulated peak rate of U(VI) reduction was ?3.8 times higher during acetate-bicarbonate treatment than under acetate-only conditions. Lack of consistent differences in microbial community structure between acetate-bicarbonate and acetate-only treatments suggest that a significantly higher rate of U(VI) reduction in the bicarbonate-impacted sediment may be due to a higher intrinsic rate of microbial reduction induced by elevated concentrations of the bicarbonate oxyanion. The findings indicate that bicarbonate amendment may be useful in improving the engineered bioremediation of uranium in aquifers.

Long, Philip E.; Williams, Kenneth H.; Davis, James A.; Fox, Patricia M.; Wilkins, Michael J.; Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.; Berman, Elena S. F.; Gupta, Manish; Chandler, Darrell P.; Murray, Chris; Peacock, Aaron D.; Giloteaux, Ludovic; Handley, Kim M.; Lovley, Derek R.; Banfield, Jillian F.

2015-02-01

207

Stacked Switched Capacitor Energy Buffer Architecture  

E-print Network

Electrolytic capacitors are often used for energy buffering applications, including buffering between single-phase ac and dc. While these capacitors have high energy density compared to film and ceramic capacitors, their ...

Chen, Minjie

208

Stacked switched capacitor energy buffer architecture  

E-print Network

Electrolytic capacitors are often used for energy buffering applications, including buffering between single-phase ac and dc. While these capacitors have high energy density compared to film and ceramic capacitors, their ...

Chen, Minjie, S.M. Massachusetts Institute of Technology

2012-01-01

209

Effect of ammonium nitrate on precipitation of Ammonium Di-Uranate (ADU) and its characteristics  

NASA Astrophysics Data System (ADS)

Effect of ammonium nitrate on precipitation of Ammonium Di-Uranate (ADU) from nitric acid medium via gaseous ammonia route had been investigated. Studies on effect of ammonium nitrate on precipitation time, particle size, shape, surface morphology, flowability, oxygen/uranium (O/U) ratio and tap density of calcined ADU were carried out at various ammonium nitrate concentrations. It was observed that, the presence of excess ammonium nitrate influences the precipitation time, particle size distribution and surface morphology of the ADU. ADU and uranium oxide were characterized with Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). Presence of ammonium nitrate during precipitation leads to the formation of bigger, porous and uniform particles as compared to the ADU prepared without ammonium nitrate additions.

Paik, Shrishma; Biswas, S.; Bhattacharya, S.; Roy, S. B.

2013-09-01

210

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2012-04-01

211

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2013-04-01

212

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2011-04-01

213

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2010-04-01

214

21 CFR 182.1127 - Aluminum ammonium sulfate.  

...2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2014-04-01

215

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2012-04-01

216

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2009-04-01 true Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2010-04-01

217

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2011-04-01

218

21 CFR 582.1127 - Aluminum ammonium sulfate.  

...2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2014-04-01

219

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2013-04-01

220

40 CFR 721.4095 - Quaternary ammonium alkyltherpropyl trialkylamine halides.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Quaternary ammonium alkyltherpropyl trialkylamine halides...Substances § 721.4095 Quaternary ammonium alkyltherpropyl trialkylamine halides...substances identified generically as quaternary ammonium alkyltherpropyl trialkylamine...

2010-07-01

221

21 CFR 172.165 - Quaternary ammonium chloride combination.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 true Quaternary ammonium chloride combination. 172.165 ...Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride combination, may be...

2010-04-01

222

40 CFR 721.4467 - Quaternary ammonium hydroxide.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Quaternary ammonium hydroxide. 721.4467 Section 721...Substances § 721.4467 Quaternary ammonium hydroxide. (a) Chemical substance...identified generically as a quaternary ammonium hydroxide (PMN P-95-1806)...

2010-07-01

223

40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.  

Code of Federal Regulations, 2010 CFR

... false Ethoxylated alkyl quaternary ammonium compound. 721.655 Section 721...655 Ethoxylated alkyl quaternary ammonium compound. (a) Chemical substance...generically as an ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is...

2010-07-01

224

40 CFR 721.10099 - Dialkyl dimethyl ammonium carbonate (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Dialkyl dimethyl ammonium carbonate (generic). 721.10099...Substances § 721.10099 Dialkyl dimethyl ammonium carbonate (generic). (a) Chemical...identified generically as dialkyl dimethyl ammonium carbonate (1:1) (PMN...

2010-07-01

225

40 CFR 721.10511 - Quaternary ammonium salts (generic).  

...2014-07-01 false Quaternary ammonium salts (generic). 721.10511 Section 721...Substances § 721.10511 Quaternary ammonium salts (generic). (a) Chemical substance...identified generically as quaternary ammonium salts (PMNs P-07-320,...

2014-07-01

226

40 CFR 721.10302 - Zinc ammonium phosphate (generic).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Zinc ammonium phosphate (generic). 721...Specific Chemical Substances § 721.10302 Zinc ammonium phosphate (generic). ...chemical substance identified generically as zinc ammonium phosphate (PMN...

2012-07-01

227

40 CFR 721.10302 - Zinc ammonium phosphate (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Zinc ammonium phosphate (generic). 721...Specific Chemical Substances § 721.10302 Zinc ammonium phosphate (generic). ...chemical substance identified generically as zinc ammonium phosphate (PMN...

2013-07-01

228

40 CFR 721.10302 - Zinc ammonium phosphate (generic).  

...2014-07-01 2014-07-01 false Zinc ammonium phosphate (generic). 721...Specific Chemical Substances § 721.10302 Zinc ammonium phosphate (generic). ...chemical substance identified generically as zinc ammonium phosphate (PMN...

2014-07-01

229

78 FR 32690 - Certain Ammonium Nitrate From Ukraine  

Federal Register 2010, 2011, 2012, 2013

...731-TA-894 (Review)] Certain Ammonium Nitrate From Ukraine Determination On...antidumping duty order on certain ammonium nitrate from Ukraine would be likely...May 2013), entitled Certain Ammonium Nitrate from Ukraine:...

2013-05-31

230

40 CFR 721.655 - Ethoxylated alkyl quaternary ammonium compound.  

Code of Federal Regulations, 2011 CFR

...Ethoxylated alkyl quaternary ammonium compound. 721.655 Section 721.655 ...Ethoxylated alkyl quaternary ammonium compound. (a) Chemical substance and significant...ethoxylated alkyl quaternary ammonium compound (PMN P-96-573) is subject...

2011-07-01

231

RESEARCH NEEDS IN RIPARIAN BUFFER RESTORATION  

EPA Science Inventory

Riparian buffer restorations are used as management tools to produce favorable water quality impacts; moreover, the basis for riparian buffers as an instrument of water quality restoration rests on a relatively firm foundation. However, the extent to which buffers can restore rip...

232

Doped LZO buffer layers for laminated conductors  

DOEpatents

A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the substrate, the biaxially textured buffer layer comprising LZO and a dopant for mitigating metal diffusion through the LZO, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.

Paranthaman, Mariappan Parans (Knoxville, TN) [Knoxville, TN; Schoop, Urs (Westborough, MA) [Westborough, MA; Goyal, Amit (Knoxville, TN) [Knoxville, TN; Thieme, Cornelis Leo Hans (Westborough, MA) [Westborough, MA; Verebelyi, Darren T. (Oxford, MA) [Oxford, MA; Rupich, Martin W. (Framingham, MA) [Framingham, MA

2010-03-23

233

Optimal Offline TCP Sender Buffer Management Strategy  

Microsoft Academic Search

The transmission control protocol (TCP) uses a sliding window in order to enforce flow control. The receiver advertises its available buffer space to the sender, which cannot transmit more data than the advertised space. Transmitted data is first copied from application buffers into TCP buffers and from there it is sent through the network. In this paper we propose a

Mugurel Ionut Andreica; Nicolae Tapus

2008-01-01

234

40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.  

...glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...hydroxymethylphosphinyl)propanoic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

2014-07-01

235

40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.  

Code of Federal Regulations, 2013 CFR

...glufosinate ammonium, butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...hydroxymethylphosphinyl)propanoic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

2013-07-01

236

40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.  

Code of Federal Regulations, 2010 CFR

...glufosinate-ammonium (butanoic acid, 2-amino-4-(hydroxymethylphosphinyl...3-methylphosphinico-propionic acid, expressed as 2-amino-4-(hydroxymethylphosphinyl...glufosinate ammonium, butanoic acid,...

2010-07-01

237

Joint Buffer & Server Allocation Van Woensel et al. Buffer and Server Allocation in General  

E-print Network

Joint Buffer & Server Allocation Van Woensel et al. Buffer and Server Allocation in General Multi-Server Abstract -- This paper deals with the joint optimization of the number of buffers and servers, an important issue since buffers and servers represent a significant amount of investment for many companies

Cruz, Frederico

238

Stress corrosion cracking of X-60 line pipe steel in a carbonate-bicarbonate solution  

SciTech Connect

An experimental system was developed to reproduce stress corrosion cracking (SCC) of API X-60 line pipe steels in highly alkaline (pH = 10) carbonate-bicarbonate (1 N sodium carbonate [Na[sub 2]CO[sub 3

Pilkey, A.K.; Lambert, S.B.; Plumtree, A. (Univ. of Waterloo, Ontario (Canada). Dept. of Mechanical Engineering)

1995-02-01

239

The Structure and Spectroscopy of Cyanate and Bicarbonate Ions. Astrophysical Implications  

NASA Astrophysics Data System (ADS)

Cyanate and bicarbonate are two ions that play active roles in many fields of physics and chemistry, including biological sciences and astrochemistry. We present here a comprehensive study of these species covering a range of phases and methodologies. We have performed theoretical calculations on the isolated ions and their hydrates with one to four water molecules, and in clusters with 15 water molecules. The predicted infrared spectra are compared with observed spectra from experiments where liquid droplets of their solutions are frozen at 14 K on a substrate, to mimic some astrophysical conditions. Crystals of cyanate and bicarbonate sodium and potassium salts are also studied experimental and theoretically. As well, the spontaneous decomposition of cyanate into bicarbonate is documented from the spectra of an aged solution. Finally, the possible astrophysical observation of bicarbonate in water-containing particles is discussed.

Moreno, M. A.; Maté, B.; Rodríguez-Lazcano, Y.; Gálvez, O.; Gómez, P. C.; Herrero, V. J.; Escribano, R.

2013-10-01

240

The structure and spectroscopy of cyanate and bicarbonate ions. Astrophysical implications.  

PubMed

Cyanate and bicarbonate are two ions that play active roles in many fields of physics and chemistry, including biological sciences and astrochemistry. We present here a comprehensive study of these species covering a range of phases and methodologies. We have performed theoretical calculations on the isolated ions and their hydrates with one to four water molecules, and in clusters with 15 water molecules. The predicted infrared spectra are compared with observed spectra from experiments where liquid droplets of their solutions are frozen at 14 K on a substrate, to mimic some astrophysical conditions. Crystals of cyanate and bicarbonate sodium and potassium salts are also studied experimental and theoretically. As well, the spontaneous decomposition of cyanate into bicarbonate is documented from the spectra of an aged solution. Finally, the possible astrophysical observation of bicarbonate in water-containing particles is discussed. PMID:23360125

Moreno, M A; Maté, B; Rodríguez-Lazcano, Y; Gálvez, O; Gómez, P C; Herrero, V J; Escribano, R

2013-10-01

241

Redox interaction of Mn–bicarbonate complexes with reaction centres of purple bacteria  

PubMed Central

It is found that dark reduction of photooxidized primary electron donor P870+ in reaction centres from purple anoxygenic bacteria (two non-sulphur Fe-oxidizing Rhodovulum iodosum and Rhodovulum robiginosum, Rhodobacter sphaeroides R-26 and sulphur alkaliphilic Thiorhodospira sibirica) is accelerated upon the addition of Mn2+ jointly with bicarbonate (30–75?mM). The effect is not observed if Mn2+ and HCO3? have been replaced by Mg2+ and HCO2?, respectively. The dependence of the effect on bicarbonate concentration suggests that formation of Mn2+–bicarbonate complexes, Mn(HCO3)+ and/or Mn(HCO3)2, is required for re-reduction of P870+ with Mn2+. The results are considered as experimental evidence for a hypothesis on possible participation of Mn–bicarbonate complexes in the evolutionary origin of oxygenic photosynthesis in the Archean era. PMID:17971330

Khorobrykh, A.A; Terentyev, V.V; Zharmukhamedov, S.K; Klimov, V.V

2007-01-01

242

Bicarbonate of soda paint stripping process validation and material characterization  

NASA Technical Reports Server (NTRS)

The Aircraft Production Division at San Antonio Air Logistics Center has conducted extensive investigation into the replacement of hazardous chemicals in aircraft component cleaning, degreasing, and depainting. One of the most viable solutions is process substitution utilizing abrasive techniques. SA-ALC has incorporated the use of Bicarbonate of Soda Blasting as one such substitution. Previous utilization of methylene chloride based chemical strippers and carbon removal agents has been replaced by a walk-in blast booth in which we remove carbon from engine nozzles and various gas turbine engine parts, depaint cowlings, and perform various other functions on a variety of parts. Prior to implementation of this new process, validation of the process was performed, and materials and waste stream characterization studies were conducted. These characterization studies examined the effects of the blasting process on the integrity of the thin-skinned aluminum substrates, the effects of the process on both air emissions and effluent disposal, and the effects on the personnel exposed to the process.

Haas, Michael N.

1995-01-01

243

Primers on molecular pathways: bicarbonate transport by the pancreas.  

PubMed

The pancreas has both endocrine and exocrine functions. As an endocrine organ, stimulation of the pancreatic ?-cells results in insulin secretion to control systemic glucose levels. The exocrine function of the pancreas and the need for alkaline pancreatic secretion (pH 8.0-8.5) have been appreciated for more than 40 years. Yet, our knowledge of the cellular mechanisms (signaling, transporters and channels) which accomplish these critical functions has evolved greatly. In the mid-1990s, basolateral Na-bicarbonate (HCO(3)(-)) uptake by NBCe1 (Slc4a4) was shown to be critical for the generation of approximately 75% of stimulated HCO(3)(-) secretion. In the last 10 years, several new HCO(3)(-) transporters in the Slc26 family and their interaction with the cystic fibrosis transmembrane conductance regulator-chloride channel have elucidated the HCO(3)(-) exit step at the ductal lumen. Most recently, both IRBIT (inositol 1,4,5-trisphosphate receptor-binding protein) and WNK [with no lysine (K)] kinase have been implicated as additional HCO(3)(-) secretory controllers. and IAP. PMID:21242704

Sin?i?, Aleksandra; Sussman, Caroline R; Romero, Michael F

2010-01-01

244

Rheogenic sodium-bicarbonate cotransport in the peritubular cell membrane of rat renal proximal tubule  

Microsoft Academic Search

The mechanism of bicarbonate transport across the peritubular cell membrane was investigated in rat kidney proximal tubules in situ by measuring cell pH and cell Na+ activity in response to sudden reduction of peritubular Na+ and\\/or HCO3-. The following observations were made: 1. sudden peritubular reduction of either ion concentration produced the same transient depolarizing potential response; 2. bicarbonate efflux

K. Yoshitomi; B.-Ch. Burckhardt; E. Frömter

1985-01-01

245

Urease-independent chemotactic responses of Helicobacter pylori to urea, urease inhibitors, and sodium bicarbonate.  

PubMed Central

Helicobacter pylori CPY3401 and an isogenic urease-negative mutant, HPT73, showed chemotactic responses to urea, flurofamide (a potent urease inhibitor), and sodium bicarbonate. Since urea and sodium bicarbonate are secreted through the gastric epithelial surface and hydrolysis of urea by urease on the bacterial surface is essential for colonization, the chemotactic response of H. pylori may be crucial for its colonization and persistence in the stomach. PMID:9119496

Mizote, T; Yoshiyama, H; Nakazawa, T

1997-01-01

246

Reduction in cardiovascular risk by sodium-bicarbonated mineral water in moderately hypercholesterolemic young adults.  

PubMed

The effects of drinking sodium-bicarbonated mineral water on cardiovascular risk in young men and women with moderate cardiovascular risk were studied. Eighteen young volunteers (total cholesterol levels >5.2 mmol/L) without any disease participated. The study consisted of two 8-week intervention periods. Subjects consumed, as supplement to their usual diet, 1 L/day control low mineral water, followed by 1 L/day bicarbonated mineral water (48 mmol/L sodium, 35 mmol/L bicarbonate and 17 mmol/L chloride). Determinations were performed at the end of the control water period and on Weeks 4 and 8 of the bicarbonated water period. Body weight, body mass index (BMI), blood pressure, dietary intake, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, apolipoprotein (Apo) A-I, Apo B, triacylgycerols, glucose, insulin, adiponectin, high-sensitivity C-reactive protein (hs-CRP), soluble adhesion molecules [soluble intercellular adhesion molecule (sICAM) and soluble vascular adhesion molecule (sVCAM)], sodium and chloride urinary excretion, and urine pH were measured. Dietary intake, body weight and BMI showed no significant variations. Systolic blood pressure decreased significantly after 4 weeks of bicarbonated water consumption, without significant differences between Weeks 4 and 8. After bicarbonated water consumption, significant reductions in total cholesterol (by 6.3%; P=.012), LDL cholesterol (by 10%; P=.001), total/HDL cholesterol (P=.004), LDL/HDL cholesterol (P=.001) and Apo B (P=.017) were observed. Serum triacylglycerol, Apo A-I, sICAM-1, sVCAM-1 and hs-CRP levels did not change. Serum glucose values tended to decrease during the bicarbonated water intervention (P=.056), but insulin levels did not vary. This sodium-bicarbonated mineral water improves lipid profile in moderately hypercholesterolemic young men and women and could therefore be applied in dietary interventions to reduce cardiovascular risk. PMID:19954956

Pérez-Granados, Ana M; Navas-Carretero, Santiago; Schoppen, Stefanie; Vaquero, M Pilar

2010-10-01

247

Acetate and Bicarbonate Assimilation and Metabolite Formation in Chlamydomonas reinhardtii: A 13C-NMR Study  

PubMed Central

Cellular metabolite analyses by 13C-NMR showed that C. reinhardtii cells assimilate acetate at a faster rate in heterotrophy than in mixotrophy. While heterotrophic cells produced bicarbonate and CO2aq, mixotrophy cells produced bicarbonate alone as predominant metabolite. Experiments with singly 13C-labelled acetate (13CH3-COOH or CH3-13COOH) supported that both the 13C nuclei give rise to bicarbonate and CO2aq. The observed metabolite(s) upon further incubation led to the production of starch and triacylglycerol (TAG) in mixotrophy, whereas in heterotrophy the TAG production was minimal with substantial accumulation of glycerol and starch. Prolonged incubation up to eight days, without the addition of fresh acetate, led to an increased TAG production at the expense of bicarbonate, akin to that of nitrogen-starvation. However, such TAG production was substantially high in mixotrophy as compared to that in heterotrophy. Addition of mitochondrial un-coupler blocked the formation of bicarbonate and CO2aq in heterotrophic cells, even though acetate uptake ensued. Addition of PSII-inhibitor to mixotrophic cells resulted in partial conversion of bicarbonate into CO2aq, which were found to be in equilibrium. In an independent experiment, we have monitored assimilation of bicarbonate via photoautotrophy and found that the cells indeed produce starch and TAG at a much faster rate as compared to that in mixotrophy and heterotrophy. Further, we noticed that the accumulation of starch is relatively more as compared to TAG. Based on these observations, we suggest that acetate assimilation in C. reinhardtii does not directly lead to TAG formation but via bicarbonate/CO2aq pathways. Photoautotrophic mode is found to be the best growth condition for the production of starch and TAG and starch in C. reinhardtii. PMID:25207648

Singh, Himanshu; Shukla, Manish R.; Chary, Kandala V. R.; Rao, Basuthkar J.

2014-01-01

248

Haemodynamic consequences of changing bicarbonate and calcium concentrations in haemodialysis fluids  

PubMed Central

Background. In a previous study we demonstrated that mild metabolic alkalosis resulting from standard bicarbonate haemodialysis induces hypotension. In this study, we have further investigated the changes in systemic haemodynamics induced by bicarbonate and calcium, using non-invasive procedures. Methods. In a randomized controlled trial with a single-blind, crossover design, we sequentially changed the dialysate bicarbonate and calcium concentrations (between 26 and 35?mmol/l for bicarbonate and either 1.25 or 1.50?mmol/l for calcium). Twenty-one patients were enrolled for a total of 756 dialysis sessions. Systemic haemodynamics was evaluated using pulse wave analysers. Bioimpedance and BNP were used to compare the fluid status pattern. Results. The haemodynamic parameters and the pre-dialysis BNP using either a high calcium or bicarbonate concentration were as follows: systolic blood pressure (+5.6 and ?4.7?mmHg; P < 0.05 for both), stroke volume (+12.3 and +5.2?ml; P < 0.05 and ns), peripheral resistances (?190 and ?171 dyne s cm?5; P < 0.05 for both), central augmentation index (+1.1% and ?2.9%; ns and P < 0.05) and BNP (?5 and ?170?ng/l; ns and P < 0.05). The need of staff intervention was similar in all modalities. Conclusions. Both high bicarbonate and calcium concentrations in the dialysate improve the haemodynamic pattern during dialysis. Bicarbonate reduces arterial stiffness and ameliorates the heart tolerance for volume overload in the interdialytic phase, whereas calcium directly increases stroke volume. The slight hypotensive effect of alkalaemia should motivate a probative reduction of bicarbonate concentration in dialysis fluid for haemodynamic reasons, only in the event of failure of classical tools to prevent intradialytic hypotension. PMID:18842671

Gabutti, Luca; Bianchi, Giorgia; Soldini, Davide; Marone, Claudio; Burnier, Michel

2009-01-01

249

Remediation of uranium contaminated soils with bicarbonate extraction and microbial U(VI) reduction  

Microsoft Academic Search

Summary A process for concentrating uranium from contaminated soils in which the uranium is first extracted with bicarbonate and then the extracted uranium is precipitated with U(VI)-reducing microorganisms was evaluated for a variety of uranuum-contaminated soils. Bicarbonate (100 mM) extracted 20–94% of the uranium that was extracted with nitric acid. The U(VI)-reducing microorganism,Desulfovibrio desulfuricans reduced the U(VI) to U(IV) in

Elizabeth J. P. Phillips; Edward R. Landa; Derek R. Lovley

1995-01-01

250

The Structure of a Cyanobacterial Bicarbonate Transport Protein, CmpA  

SciTech Connect

Cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of the food chain by fixing carbon and nitrogen into cellular biomass. To compensate for the low selectivity of Rubisco for CO? over O?, Cyanobacteria have developed highly efficient CO?concentrating machinery of which the ABC transport system CmpABCD from Synechocystis PCC 6803 is one component. Here we describe the structure of the bicarbonate binding protein, CmpA, in the absence and presence of bicarbonate and carbonic acid. CmpA is highly homologous to the nitrate transport protein, NrtA. CmpA binds carbonic acid at the entrance to the ligand-binding pocket whereas bicarbonate binds in nearly an identical location compared to nitrate binding to NrtA. Unexpectedly, bicarbonate binding is accompanied by a metal ion, identified as Ca²? via inductively coupled plasma optical emission spectrometry. The binding of bicarbonate and metal is highly cooperative and suggests that CmpA co-transports bicarbonate and calcium.

Koropatkin, Nicole M.; Koppenaal, David W.; Pakrasi, Himadri B.; Smith, Thomas J.

2007-01-26

251

Phase diagram of ammonium nitrate  

SciTech Connect

Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N{sub 2}, N{sub 2}O, and H{sub 2}O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV{sup ?} transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

Dunuwille, Mihindra; Yoo, Choong-Shik, E-mail: csyoo@wsu.edu [Department of Chemistry and Institute for Shock Physics, Washington State University, Pullman, Washington 99164 (United States)] [Department of Chemistry and Institute for Shock Physics, Washington State University, Pullman, Washington 99164 (United States)

2013-12-07

252

Substrate specificity of Rhbg: ammonium and methyl ammonium transport.  

PubMed

Rhbg is a nonerythroid membrane glycoprotein belonging to the Rh antigen family. In the kidney, Rhbg is expressed at the basolateral membrane of intercalated cells of the distal nephron and is involved in NH4+ transport. We investigated the substrate specificity of Rhbg by comparing transport of NH3/NH4+ with that of methyl amine (hydrochloride) (MA/MA+), often used to replace NH3/NH4+, in oocytes expressing Rhbg. Methyl amine (HCl) in solution exists as neutral methyl amine (MA) in equilibrium with the protonated methyl ammonium (MA+). To assess transport, we used ion-selective microelectrodes and voltage-clamp experiments to measure NH3/NH4+- and MA/MA+-induced intracellular pH (pH(i)) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pH(i) consistent with electrogenic NH4+ transport. These changes were significantly larger than in H2O-injected oocytes. The NH3/NH4+-induced current was not inhibited in the presence of barium or in the absence of Na+. In Rhbg oocytes, MA/MA+ caused an inward current but an increase (rather than a decrease) in pH(i). MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pH(i) increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pH(i) in oocytes expressing Rhbg but had no effect on control oocytes. These results indicate that MA/MA+ is transported by Rhbg but differently than NH3/NH4+. The protonated MA+ is likely a direct substrate whose transport resembles that of NH4+. Transport of electroneutral MA is also enhanced by expression of Rhbg. PMID:20592240

Nakhoul, Nazih L; Abdulnour-Nakhoul, Solange M; Boulpaep, Emile L; Rabon, Edd; Schmidt, Eric; Hamm, L Lee

2010-09-01

253

Biodegradation of rocket propellent waste, ammonium perchlorate  

NASA Technical Reports Server (NTRS)

The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

Naqui, S. M. Z.

1975-01-01

254

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2010 CFR

... ). It is prepared by the sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard, white or translucent mass. (b) The ingredient meets the specifications of the Food Chemicals...

2010-04-01

255

Buffered Electrochemical Polishing of Niobium  

SciTech Connect

The standard preparation of superconducting radio-frequency (SRF) cavities made of pure niobium include the removal of a 'damaged' surface layer, by buffered chemical polishing (BCP) or electropolishing (EP), after the cavities are formed. The performance of the cavities is characterized by a sharp degradation of the quality factor when the surface magnetic field exceeds about 90 mT, a phenomenon referred to as 'Q-drop'. In cavities made of polycrystalline fine grain (ASTM 5) niobium, the Q-drop can be significantly reduced by a low-temperature ({approx} 120 C) 'in-situ' baking of the cavity if the chemical treatment was EP rather than BCP. As part of the effort to understand this phenomenon, we investigated the effect of introducing a polarization potential during buffered chemical polishing, creating a process which is between the standard BCP and EP. While preliminary results on the application of this process to Nb cavities have been previously reported, in this contribution we focus on the characterization of this novel electrochemical process by measuring polarization curves, etching rates, surface finish, electrochemical impedance and the effects of temperature and electrolyte composition. In particular, it is shown that the anodic potential of Nb during BCP reduces the etching rate and improves the surface finish.

Gianluigi Ciovati, Hui Tian, Sean Corcoran

2011-03-01

256

Electrochemically and bioelectrochemically induced ammonium recovery.  

PubMed

Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made. This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems. PMID:25651406

Gildemyn, Sylvia; Luther, Amanda K; Andersen, Stephen J; Desloover, Joachim; Rabaey, Korneel

2015-01-01

257

Ammonium and urea removal by Spirulina platensis  

Microsoft Academic Search

Different concentrations either of ammonium chloride or urea were used in batch and fed-batch cultivations of Spirulina platensis to evaluate the possibility of substituting nitrate by cheaper reduced nitrogen sources in wastewaters biotreatment. The\\u000a maximum nitrogen concentration able to sustain the batch growth of this microalga without inhibition was 1.7 mM in both cases.\\u000a Ammonium chloride was limiting for the growth

A. Converti; S. Scapazzoni; A. Lodi; J. C. M. Carvalho

2006-01-01

258

The influence of ammonium on nitrate reduction in wheat seedlings  

Microsoft Academic Search

Ammonium markedly inhibited nitrate absorption by nitrogenstarved wheat seedlings but did not decrease the proportion of absorbed nitrate that was reduced. Seedlings high in nitrate (absorbed prior to the experimental periods) reduced similar amounts of this nitrate regardless of whether or not ammonium was present and being absorbed during the period of measurement. Ammonium or products of ammonium assimilation did

P. L. Minotti; Doris Craig Williams; W. A. Jackson

1969-01-01

259

Thermal decomposition of sodium bicarbonate and its effect on the reaction of sodium bicarbonate and sulfur dioxide in a simulated flue gas  

SciTech Connect

The effect of thermally decomposing sodium bicarbonate while simultaneously reacting with SO/sub 2/, was studied. The study was performed by quantitatively determining the rate of thermal decomposition as a function of particle size in an SO/sub 2/ free gas stream. The rate of reaction of sodium carbonate (product of the thermal decomposition) with SO/sub 2/ was then studied, and the data applied to a pore-plugging model which accounts for the loss in reactivity with increased reaction time. The reaction of sodium bicarbonate with SO/sub 2/ was then studied and the results compared to that for sodium carbonate. From the analysis of the data, the activation energy for the thermal decomposition reaction, the SO/sub 2/ sodium carbonate and SO/sub 2/ sodium bicarbonate reaction were derived. The thermal decomposition reaction of sodium biocarbonate was found to be similar to that of calcium carbonate below the point where heat transfer is rate limiting. The degree of conversion of sodium bicarbonate was found to be 12-17 times greater (depending on particle size) than that of sodium carbonate in the temperature range 250/sup 0/-350/sup 0/F (120/sup 0/-177/sup 0/C). This greater conversion was qualitatively explained by hypothesizing the formation of an activated species during thermal decomposition which would be more chemically reactive.

Keener, T.C.

1982-01-01

260

Bicarbonate Increases Tumor pH and Inhibits Spontaneous Metastases  

PubMed Central

The external pH of solid tumors is acidic as a consequence of increased metabolism of glucose and poor perfusion. Acid pH has been shown to stimulate tumor cell invasion and metastasis in vitro and in cells before tail vein injection in vivo. The present study investigates whether inhibition of this tumor acidity will reduce the incidence of in vivo metastases. Here, we show that oral NaHCO3 selectively increased the pH of tumors and reduced the formation of spontaneous metastases in mouse models of metastatic breast cancer. This treatment regimen was shown to significantly increase the extracellular pH, but not the intracellular pH, of tumors by 31P magnetic resonance spectroscopy and the export of acid from growing tumors by fluorescence microscopy of tumors grown in window chambers. NaHCO3 therapy also reduced the rate of lymph node involvement, yet did not affect the levels of circulating tumor cells, suggesting that reduced organ metastases were not due to increased intravasation. In contrast, NaHCO3 therapy significantly reduced the formation of hepatic metastases following intrasplenic injection, suggesting that it did inhibit extravasation and colonization. In tail vein injections of alternative cancer models, bicarbonate had mixed results, inhibiting the formation of metastases from PC3M prostate cancer cells, but not those of B16 melanoma. Although the mechanism of this therapy is not known with certainty, low pH was shown to increase the release of active cathepsin B, an important matrix remodeling protease. PMID:19276390

Robey, Ian F.; Baggett, Brenda K.; Kirkpatrick, Nathaniel D.; Roe, Denise J.; Dosescu, Julie; Sloane, Bonnie F.; Hashim, Arig Ibrahim; Morse, David L.; Raghunand, Natarajan; Gatenby, Robert A.; Gillies, Robert J.

2010-01-01

261

Bicarbonate permeability of the outwardly rectifying anion channel.  

PubMed

Single anion-selective channels have been studied in cultured human epithelial cells using the patch-clamp technique. Three cell types were used as models for different anion transport systems: (i) PANC-1, a cell line derived from the pancreatic duct, (ii) T84, a Cl-secreting colonic cell line, and (iii) primary cultures of sweat duct epithelium. Outwardly rectifying anion-selective channels were observed in all three preparations and were indistinguishable with respect to conductance, selectivity and gating. Striking similarities between HCO3- and Cl-secreting epithelia, and the high density of outward rectifiers in pancreatic cells prompted us to study HCO3 permeation through this channel. HCO3 permeability was significant when channels were bathed in symmetrical 150 mM HCO3 solutions, Cl-HCO3 mixtures, and under bi-ionic conditions with outwardly and inwardly directed HCO3 gradients. Permeability ratios (PHCO3/PCl) estimated from bi-ionic reversal potentials ranged from 0.50 to 0.64, although conductance ratios greater than 1.2 were observed with high extracellular pH. Chloride did not inhibit HCO3 permeation noticeably but rather had a small stimulatory effect when present on the opposite side of the membrane. The prevalence of outward rectifiers in PANC-1 and their permeability to bicarbonate suggests the channel may have a dual role in HCO3 secretion; to allow Cl recycling at the apical membrane and to mediate some of the HCO3 flux. Defective modulation of this channel in cystic fibrosis might provide a common basis for dysfunction in epithelia having very different anion transport properties (e.g., HCO3 secretion, Cl secretion and Cl absorption. PMID:2482894

Tabcharani, J A; Jensen, T J; Riordan, J R; Hanrahan, J W

1989-12-01

262

Determination of antibacterial quaternary ammonium compounds in lozenges by capillary electrophoresis.  

PubMed

A method for the specific determination of three quaternary ammonium compounds, benzalkonium chloride, cetylpyridinium chloride and dequalinium chloride, used as antibacterial agents in candy-based lozenges, is described based on capillary zone electrophoresis. It is shown that, following optimisation of buffer composition with respect to organic modifier concentration. pH and buffer concentration together with the inclusion of sodium dodecylsulphate as an ion-pairing agent in the case of dequalinium chloride, these analytes migrate in less than 5 min. The resultant electrophoretic peaks are sharp and readily quantified. The individual alkyl components of benzalkonium chloride can be resolved as can related impurities in dequalinium chloride lozenges. The quantitative characteristics of the assay method, based on peak areas normalised with respect to migration times, are reported and the method is compared with a previously published method based on liquid chromatography. PMID:9542144

Taylor, R B; Toasaksiri, S; Reid, R G

1998-03-01

263

Base excess or buffer base (strong ion difference) as measure of a non-respiratory acid-base disturbance.  

PubMed

Stewart in 1983 (Can J Physiol Pharmacol 1983: 61: 1444) reintroduced plasma buffer base under the name "strong ion difference" (SID). Buffer base was originally introduced by Singer and Hastings in 1948 (Medicine (Baltimore) 1948: 27: 223). Plasma buffer base, which is practically equal to the sum of bicarbonate and albuminate anions, may be increased due to an excess of base or due to an increased albumin concentration. Singer and Hastings did not consider changes in albumin as acid-base disorders and therefore used the base excess, i.e., the actual buffer base minus the buffer base at normal pH and pCO2, as measure of a non-respiratory acid-base disturbance. Stewart and followers, however, consider changes in albumin concentration to be acid-base disturbances: a patient with normal pH, pCO2, and base excess but with increased plasma buffer base due to increased plasma albumin concentration get the diagnoses metabolic (strong ion) alkalosis (because plasma buffer base is increased) combined with metabolic hyperalbuminaemic acidosis. Extrapolating to whole blood, anaemia and polycytaemia should represent types of metabolic alkalosis and acidosis, respectively. This reveals that the Stewart approach is absurd and anachronistic in the sense that an increase or decrease in any anion is interpreted as indicating an excess or deficit of a specific acid. In other words, a return to the archaic definitions of acids and bases as being the same as anions and cations. We conclude that the acid-base status (the hydrogen ion status) of blood and extracellular fluid is described in terms of the arterial pH, the arterial pCO2, and the extracellular base excess. It is measured with a modern pH-blood gas analyser. The electrolyte status of the plasma is a description of the most important electrolytes, usually measured in venous blood with a dedicated electrolyte analyser, i.e., Na+, Cl-, HCO3-, and K+. Albumin anions contribute significantly to the anions, but calculation requires measurement of pH in addition to albumin and is usually irrelevant. The bicarbonate concentration may be used as a screening parameter of a nonrespiratory acid-base disturbance when respiratory disturbances are taken into account. A disturbance in the hydrogen ion status automatically involves a disturbance in the electrolyte status, whereas the opposite need not be the case. PMID:8599264

Siggaard-Andersen, O; Fogh-Andersen, N

1995-01-01

264

Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men.  

PubMed

Creatine and sodium bicarbonate supplementation independently increase exercise performance, but it remains unclear whether combining these 2 supplements is more beneficial on exercise performance. The purpose of this study was to evaluate the impact of combining creatine monohydrate and sodium bicarbonate supplementation on exercise performance. Thirteen healthy, trained men (21.1 ± 0.6 years, 23.5 ± 0.5 kg·m(-2), 66.7 ± 5.7 ml·(kg·m)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 g·kg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 g·kg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 g·kg(-1) sodium bicarbonate). Each condition consisted of supplementation for 2 days followed by a 3-week washout. Peak power, mean power, relative peak power, and bicarbonate concentrations were assessed during six 10-second repeated Wingate sprint tests on a cycle ergometer with a 60-second rest period between each sprint. Compared with Pl, relative peak power was significantly higher in Cr (4%) and Cr + Sb (7%). Relative peak power was significantly lower in sprints 4-6, compared with that in sprint 1, in both Pl and Cr. However, in Cr + Sb, sprint 6 was the only sprint significantly lower compared with sprint 1. Pre-Wingate bicarbonate concentrations were significantly higher in Cr + Sb (10%), compared with in Pl and Cr, and mean concentrations remained higher after sprint 6, although not significantly. Combining creatine and sodium bicarbonate supplementation increased peak and mean power and had the greatest attenuation of decline in relative peak power over the 6 repeated sprints. These data suggest that combining these 2 supplements may be advantageous for athletes participating in high-intensity, intermittent exercise. PMID:23254493

Barber, James J; McDermott, Ann Y; McGaughey, Karen J; Olmstead, Jennifer D; Hagobian, Todd A

2013-01-01

265

Buffers Strips, Common-Sense Conservation  

NSDL National Science Digital Library

This recent publication from the Natural Resources Conservation Service (NRCS) and the National Conservation Buffer Team focuses on the practices, agricultural programs, and national programs that promote conservation buffers -- "strips or small areas of land in permanent vegetation" to help control potential pollutants and other environmental concerns. NRCS outlines specific programs and educational initiatives for many different types of "filter strips, field borders, grassed waterways, field windbreaks, shelterbelts, contour grass strips, and riparian (streamside) buffers."

266

Melatonin: Buffering the Immune System  

PubMed Central

Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed. PMID:23609496

Carrillo-Vico, Antonio; Lardone, Patricia J.; Álvarez-Sánchez, Nuria; Rodríguez-Rodríguez, Ana; Guerrero, Juan M.

2013-01-01

267

All-optical buffering for DPSK packets  

NASA Astrophysics Data System (ADS)

Advanced modulation formats, such as DPSK, DQPSK, QAM, have become the mainstream technologies in the optical network over 40Gb/s, the DPSK format is the fundamental of all advanced modulation formats. Optical buffers, as a key element for temporarily storing packets in order to synchronization or contention resolution in optical nodes, must be adapted to this new requirement. Different from other current buffers to store the NRZ or RZ format, an all-optical buffer of storing DPSK packets based on nonlinear polarization rotation in SOA is proposed and demonstrated. In this buffer, a section of PMF is used as fiber delay line to maintain the polarization states unchanged, the driver current of SOA is optimized, and no amplifier is required in the fiber loop. A packet delay resolution of 400ns is obtained and storage for tens rounds is demonstrated without significant signal degradation. Using proposed the new tunable DPSK demodulator, bit error rate has been measured after buffering for tens rounds for 10Gb/s data payload. Configurations for First-in First-out (FIFO) buffer or First-in Last-out (FILO) buffer are proposed based on this buffer. The buffer is easy control and suitable for integration. The terminal contention caused by different clients can be mitigated by managing packets delays in future all-optical network, such as optical packet switching network and WDM switching network.

Liu, Guodong; Wu, Chongqing; Liu, Lanlan; Wang, Fu; Mao, Yaya; Sun, Zhenchao

2013-12-01

268

SODR Memory Control Buffer Control ASIC  

NASA Technical Reports Server (NTRS)

The Spacecraft Optical Disk Recorder (SODR) is a state of the art mass storage system for future NASA missions requiring high transmission rates and a large capacity storage system. This report covers the design and development of an SODR memory buffer control applications specific integrated circuit (ASIC). The memory buffer control ASIC has two primary functions: (1) buffering data to prevent loss of data during disk access times, (2) converting data formats from a high performance parallel interface format to a small computer systems interface format. Ten 144 p in, 50 MHz CMOS ASIC's were designed, fabricated and tested to implement the memory buffer control function.

Hodson, Robert F.

1994-01-01

269

Renal ammonium excretion after an acute acid load: blunted response in uric acid stone formers but not in patients with type 2 diabetes  

PubMed Central

Idiopathic uric acid nephrolithiasis is characterized by elevated urinary net acid excretion and insufficient buffering by ammonium, resulting in excessively acidic urine and titration of the relatively soluble urate anion to insoluble uric acid. Patients with type 2 diabetes have similar changes in urinary pH, net acid excretion, and ammonium in 24-h urine collections at baseline, even after controlling for dietary factors, and are at increased risk for uric acid nephrolithiasis. However, not all patients with type 2 diabetes develop kidney stones, suggesting that uric acid stone formers may have additional urinary defects, perhaps not apparent at baseline. We performed a metabolic study of 14 patients with idiopathic uric acid nephrolithiasis, 13 patients with type 2 diabetes, and 8 healthy control subjects of similar body mass index. After equilibration on a fixed diet for 5 days, subjects were given a single oral acid load (50 meq ammonium chloride), and urine was collected hourly for 4 h. Uric acid stone formers had a lower ammonium excretory response to acute acid loading compared with diabetic and nondiabetic nonstone formers, suggesting that an ammonium excretory defect unique to uric acid stone formers was unmasked by the acid challenge. The Zucker diabetic fatty rat also did not show impaired urinary ammonium excretion in response to acute acid challenge. A blunted renal ammonium excretory response to dietary acid loads may contribute to the pathogenesis of idiopathic uric acid nephrolithiasis. PMID:24026180

Bobulescu, I. Alexandru; Maalouf, Naim M.; Capolongo, Giovanna; Adams-Huet, Beverley; Rosenthal, Tara R.; Moe, Orson W.

2013-01-01

270

BuffersA guide for the preparation and use of buffers in biological systems  

E-print Network

, an affiliate of Merck KGaA, Darmstadt, Germany. All rights reserved. Buffers #12;ii A word to our valued, Marketing #12;iii Table of Contents: Why does Calbiochem® Biochemicals Publish a Booklet on Buffers

Lebendiker, Mario

271

Corrosion Behavior of Carbon Steel for Overpack in Groundwater Containing Bicarbonate Ions  

NASA Astrophysics Data System (ADS)

Carbon steel is considered in Japan the candidate material for overpacks in high-level radioactive waste disposal. Effects of bicarbonate solutions on the corrosion behavior and corrosion products of carbon steel were investigated by electrochemical measurements, FT-IR and XRD analyses. The anodic polarization measurements showed that bicarbonate ions (HCO3-) accelerated the anodic dissolution and the outer layer film formation of carbon steel in the case of high concentrations, on the other hand, it inhibited these processes in the case of low concentrations. The FT-IR and XRD analyses of the anodized film showed that siderite (FeCO3) was formed in 0.5 to 1.0mol/L bicarbonate solution, and Fe2(OH)2CO3 in 0.1 to 0.2mol/L bicarbonate solution, while Fe6(OH)12CO3 was formed in 0.02 to 0.05mol/L bicarbonate solutions. The stability of these corrosion products was able to be explained by using the actual potential-pH diagrams for the Fe-H2O-CO2 system.

Nishimura, Toshiyasu; Dong, Junpha

272

Role of the Na+/H+ antiporter in rat proximal tubule bicarbonate absorption.  

PubMed Central

Amiloride and the more potent amiloride analog, 5-(N-t-butyl) amiloride (t-butylamiloride), were used to examine the role of the Na+/H+ antiporter in bicarbonate absorption in the in vivo microperfused rat proximal convoluted tubule. Bicarbonate absorption was inhibited 29, 46, and 47% by 0.9 mM or 4.3 mM amiloride, or 1 mM t-butylamiloride, respectively. Sensitivity of the Na+/H+ antiporter to these compounds in vivo was examined using fluorescent measurements of intracellular pH with (2', 7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein (BCECF). Amiloride and t-butylamiloride were shown to be as potent against the antiporter in vivo as in brush border membrane vesicles. A model of proximal tubule bicarbonate absorption was used to correct for changes in the luminal profiles for pH and inhibitor concentration, and for changes in luminal flow rate in the various series. We conclude that the majority of apical membrane proton secretion involved in transepithelial bicarbonate absorption is mediated by the Na+-dependent, amiloride-sensitive Na+H+ antiporter. However, a second mechanism of proton secretion contributes significantly to bicarbonate absorption. This mechanism is Na+-independent and amiloride-insensitive. PMID:2888788

Preisig, P A; Ives, H E; Cragoe, E J; Alpern, R J; Rector, F C

1987-01-01

273

Radiolysis of Bicarbonate and Carbonate Aqueous Solutions: Product Analysis and Simulation of Radiolytic Processes  

SciTech Connect

An understanding of the radiation-induced effects in groundwater is essential to evaluate the safe geological disposal of spent fuel. In groundwater, the bicarbonate ion is the predominant and common anion; this work investigated radiation-induced chemical reactions of (bi)carbonate aqueous solutions with steady-state irradiation and pulse radiolysis methods. Aqueous solutions of sodium (bi)carbonate as high as 50 mmol.dm{sup -3} were used. The formation of formate, oxalate, and H{sub 2}O{sub 2} were measured under different conditions. A complete set of reaction steps and reliable kinetic data for the radiolysis of (bi)carbonate aqueous solutions at ionic strength close to the groundwater were proposed. Kinetic calculations were completed based on the proposed reaction steps and the kinetic data obtained in the present work. The results from the calculation are in good agreement with the experimental results. With these proposed reaction steps and kinetic data, computer simulation can be performed to predict the yield of radiolytic products of (bi)carbonate aqueous solutions as a function of irradiation time and used to evaluate the safety of geological disposal options of spent fuel.

Cai Zhongli; Li Xifeng; Katsumura, Yosuke; Urabe, Osamu [University of Tokyo (Japan)

2001-11-15

274

Effects of bicarbonate ion on serotonin binding to rat frontal cortex membranes.  

PubMed

Several factors are known to regulate ligand binding to 5-hydroxytryptamine (5-HT) receptors. In the present experiments we have investigated the mechanism by which bicarbonate ion modify central 5-HT receptor sensitivity in rats. Mn(2+) (10(?6)-10(?3)M) increased specific [(3)H]5-HT binding to 5-HT(1) receptor sites (+60-70%), this effect being further enhanced by the addition of HCO(?)(3) (+300-400%), while the binding of [(3)H]spiperone binding to 5-HT(2) receptor sites was not affected by Mn(2+) and HCO(?)(3). The effect of other divalent cations, Mg(2+), Cu(2+), Ca(2+) and Fe(2+), however, were not enhanced by the addition of HCO(?)(3). Scatchard analysis indicated that the effect of bicarbonate ion was associated with increase in the number of high affinity binding sites and appearance of low affinity binding sites. This effect of bicarbonate ion was characterized by decreased dissociation rate of the specific binding, was temperature-dependent, reduced by N-ethylmaleimide and iodoacetamide, and was completely inhibited by ascorbate, dithiothreitol and 2-mercaptoethanol. The effect was not influenced by GTP or GppNHp but it was significantly inhibited by ATP. Pretreatment of membranes with Triton X-100 (0.1%) increased the effect of bicarbonate ion. From these results, it is suggested that bicarbonate ion specifically interacts with Mn(2+) and selectively increases [(3)H]5-HT binding. PMID:20493052

Fujita, M; Seo, T; Nishio, H; Segawa, T

1986-01-01

275

The use of sodium bicarbonate in oral hygiene products and practice.  

PubMed

Early dentifrices contained natural ingredients, mostly in coarse particle form, and were quite abrasive. Salts, either sodium chloride, sodium bicarbonate, or a mixture of both, have also been used for tooth cleaning because of their ready availability and low cost. Because of both their relatively low intrinsic hardness and their high solubility, another advantage is low abrasivity. Their biggest disadvantage is a salty, unpalatable taste. Many modern dentifrices that contain sodium bicarbonate, either as the sole abrasive or one of several, disguise the saltiness with flavoring and sweetening agents. An almost inverse relationship exists between the percentage of baking soda in a dentifrice and its abrasivity. Sodium bicarbonate has no anticaries activity per se but is compatible with fluoride. In high concentrations, sodium bicarbonate is bactericidal against most periodontal pathogens. Most clinical studies have not found significant differences in periodontal response to baking soda as compared with other commercial dentifrices, probably because of its rapid clearance from the gingival sulcus. Sodium bicarbonate may not be the "magic bullet" for curing dental diseases, but its safety (if ingested), low abrasivity, low cost, and compatibility with fluoride make it a consummate dentifrice ingredient. PMID:11524863

Newbrun, E

1996-01-01

276

The use of sodium bicarbonate in oral hygiene products and practice.  

PubMed

Early dentifrices contained natural ingredients, mostly in coarse particle form, and were quite abrasive. Salts, either sodium chloride, sodium bicarbonate, or a mixture of both, have also been used for tooth cleaning because of their ready availability and low cost. Because of both their relatively low intrinsic hardness and their high solubility, another advantage is low abrasivity. Their biggest disadvantage is a salty, unpalatable taste. Many modern dentifrices that contain sodium bicarbonate, either as the sole abrasive or one of several, disguise the saltiness with flavoring and sweetening agents. An almost inverse relationship exists between the percentage of baking soda in a dentifrice and its abrasivity. Sodium bicarbonate has no anticaries activity per se but is compatible with fluoride. In high concentrations, sodium bicarbonate is bactericidal against most periodontal pathogens. Most clinical studies have not found significant differences in periodontal response to baking soda as compared with other commercial dentifrices, probably because of its rapid clearance from the gingival sulcus. Sodium bicarbonate may not be the "magic bullet" for curing dental diseases, but its safety (if ingested), low abrasivity, low cost, and compatibility with fluoride make it a consummate dentifrice ingredient. PMID:12017930

Newbrun, E

1997-01-01

277

Crystallization characteristics of ammonium uranyl carbonate (AUC) in ammonium carbonate solutions  

NASA Astrophysics Data System (ADS)

Ammonium carbonate solutions with an excessive amount of NH 3 were produced in a commercial AUC (ammonium uranyl carbonate) conversion plant. In this study the AUC crystals, precipitated with uranyl nitrate and ammonium carbonate solutions prepared in the laboratory, were characterized to determine the feasibility of recycling ammonium carbonate solution. The AUC crystals were easily agglomerated with the increasing concentration of CO 32- and mole ratio of {NH 4+}/{CO 32-} in ammonium carbonate solution. Effects of a mixing system for the solution in the AUC crystallizer and the feed location of the solution on the agglomeration of AUC crystals were also studied along with the effects of agglomerated AUC powders on UO 2 powders. Finally, the feasibility of manufacturing UO 2 fuel with a sintered pellet density of 10.52 g/cm 3, using the AUC powders generated in this experiment, was demonstrated.

Tae-Joon, Kim; Kyung-Chai, Jeong; Jin-Ho, Park; In-Soon, Chang; Cheong-Song, Choi

1994-05-01

278

Calcium sulphate in ammonium sulphate solution  

USGS Publications Warehouse

Calcium sulphate, at 25?? C., is two-thirds as soluble in dilute (o.i mol per liter) and twice as soluble in concentrated (3 mois per liter) ammonium sulphate solution as in water. The specific electric conductivity of concentrated ammonium sulphate solutions is lessened by saturating with calcium sulphate. Assuming that dissociation of ammonium sulphate takes place into 2NH4?? and SO4" and of calcium sulphate into Ca and SO4" only, and that the conductivity is a measure of such dissociation, the solubility of calcium sulphate in dilute ammonium sulphate solutions is greater than required by the mass-law. The conductivity of the dilute mixtures may be accurately calculated by means of Arrhenius' principle of isohydric solutions. In the data obtained in these calculations, the concentration of non-dissociated calcium sulphate decreases with increasing ammonium sulphate. The work as a whole is additional evidence of the fact that we are not yet in possession of all the factors necessary for reconciling the mass-law to the behavior of electrolytes. The measurements above described were made in the chemical laboratory of the University of Michigan.

Sullivan, E.C.

1905-01-01

279

Benchmark binding energies of ammonium and alkyl-ammonium ions interacting with water. Are ammonium-water hydrogen bonds strong?  

NASA Astrophysics Data System (ADS)

Alkyl-ammonium ion/water interactions are investigated using high level quantum computations, yielding thermodynamics data in good agreement with gas-phase experiments. Alkylation and hydration lead to weaken the NHsbnd O hydrogen bonds. Upon complete hydration by four water molecules, their main features are close to those of the OHsbnd O bond in the isolated water dimer. Energy decomposition analyses indicate that hydration of alkyl-ammonium ions are mainly due to electrostatic/polarization effects, as for hard monoatomic cations, but with a larger effect of dispersion.

Vallet, Valérie; Masella, Michel

2015-01-01

280

Resilience to suicidality: The buffering hypothesis  

Microsoft Academic Search

Recent years have seen a growing interest into resilience to suicidality, which has been described as a perception or set of beliefs which buffer individuals from suicidality in the face of stressors. The current review extends this research by introducing the buffering hypothesis, a framework for the investigation of resilience to suicidality. The key proposal of this is that psychological

Judith Johnson; Alex M. Wood; Patricia Gooding; Peter J. Taylor; Nicholas Tarrier

2011-01-01

281

Color image quantization for frame buffer display  

Microsoft Academic Search

Algorithms for adaptive, tapered quantization of color images are described. The research is motivated by the desire to display high-quality reproductions of color images with small frame buffers. It is demonstrated that many color images which would normally require a frame buffer having 15 bits per pixel can be quantized to 8 or fewer bits per pixel with little subjective

Paul Heckbert

1982-01-01

282

METAMORPHIC VIRUSES WITH BUILT BUFFER OVERFLOW  

E-print Network

METAMORPHIC VIRUSES WITH BUILT BUFFER OVERFLOW The Faculty of the Department of Computer Science of the Requirements for the Degree METAMORPHIC VIRUSES WITH BUILT BUFFER OVERFLOW A Research Project Presented of the Requirements for the Degree Master of Computer Science by Ronak Shah Spring 2010 METAMORPHIC VIRUSES WITH BUILT

Stamp, Mark

283

Understanding the Science Behind Riparian Forest Buffers  

E-print Network

a Understanding the Science Behind Riparian Forest Buffers: Effects on Water Quality #12;b *Faculty Cheatham Hall, Blacksburg, VA 24061 Understanding the Science Behind Riparian Forest Buffers: Effects on Water Quality by Julia C. Klapproth and James E. Johnson* The riparian area is that area of land located

Liskiewicz, Maciej

284

Understanding the Science Behind Riparian Forest Buffers  

E-print Network

Understanding the Science Behind Riparian Forest Buffers: Planning, Establishment, and Maintenance Riparian Forest Buffers: Planning, Establishment, and Maintenance by Julia C. Klapproth and James E. Johnson* The riparian area is that area of land located immediately adjacent to streams, lakes, or other

Liskiewicz, Maciej

285

Understanding the Science Behind Riparian Forest Buffers  

E-print Network

a Understanding the Science Behind Riparian Forest Buffers: Effects on Plant and Animal Communities, Virginia Tech, 324 Cheatham Hall, Blacksburg, VA 24061 Understanding the Science Behind Riparian Forest Buffers: Effects on Plant and Animal Communities by Julia C. Klapproth and James E. Johnson* The riparian

Liskiewicz, Maciej

286

Understanding the Science Behind Riparian Forest Buffers  

E-print Network

Understanding the Science Behind Riparian Forest Buffers: Factors Influencing Adoption #12;*Faculty Cheatham Hall, Blacksburg, VA 24061 Understanding the Science Behind Riparian Forest Buffers: Factors Influencing Adoption by Julia C. Klapproth and James E. Johnson* The riparian area is that area of land

Liskiewicz, Maciej

287

The buffer capacity of airway epithelial secretions  

PubMed Central

The pH of airway epithelial secretions influences bacterial killing and mucus properties and is reduced by acidic pollutants, gastric reflux, and respiratory diseases such as cystic fibrosis (CF). The effect of acute acid loads depends on buffer capacity, however the buffering of airway secretions has not been well characterized. In this work we develop a method for titrating micro-scale (30 ?l) volumes and use it to study fluid secreted by the human airway epithelial cell line Calu-3, a widely used model for submucosal gland serous cells. Microtitration curves revealed that HCO?3 is the major buffer. Peak buffer capacity (?) increased from 17 to 28 mM/pH during forskolin stimulation, and was reduced by >50% in fluid secreted by cystic fibrosis transmembrane conductance regulator (CFTR)-deficient Calu-3 monolayers, confirming an important role of CFTR in HCO?3 secretion. Back-titration with NaOH revealed non-volatile buffer capacity due to proteins synthesized and released by the epithelial cells. Lysozyme and mucin concentrations were too low to buffer Calu-3 fluid significantly, however model titrations of porcine gastric mucins at concentrations near the sol-gel transition suggest that mucins may contribute to the buffer capacity of ASL in vivo. We conclude that CFTR-dependent HCO?3 secretion and epithelially-derived proteins are the predominant buffers in Calu-3 secretions. PMID:24917822

Kim, Dusik; Liao, Jie; Hanrahan, John W.

2014-01-01

288

The buffer capacity of airway epithelial secretions.  

PubMed

The pH of airway epithelial secretions influences bacterial killing and mucus properties and is reduced by acidic pollutants, gastric reflux, and respiratory diseases such as cystic fibrosis (CF). The effect of acute acid loads depends on buffer capacity, however the buffering of airway secretions has not been well characterized. In this work we develop a method for titrating micro-scale (30 ?l) volumes and use it to study fluid secreted by the human airway epithelial cell line Calu-3, a widely used model for submucosal gland serous cells. Microtitration curves revealed that HCO(-) 3 is the major buffer. Peak buffer capacity (?) increased from 17 to 28 mM/pH during forskolin stimulation, and was reduced by >50% in fluid secreted by cystic fibrosis transmembrane conductance regulator (CFTR)-deficient Calu-3 monolayers, confirming an important role of CFTR in HCO(-) 3 secretion. Back-titration with NaOH revealed non-volatile buffer capacity due to proteins synthesized and released by the epithelial cells. Lysozyme and mucin concentrations were too low to buffer Calu-3 fluid significantly, however model titrations of porcine gastric mucins at concentrations near the sol-gel transition suggest that mucins may contribute to the buffer capacity of ASL in vivo. We conclude that CFTR-dependent HCO(-) 3 secretion and epithelially-derived proteins are the predominant buffers in Calu-3 secretions. PMID:24917822

Kim, Dusik; Liao, Jie; Hanrahan, John W

2014-01-01

289

Multicommodity Flow Algorithms for Buffered Global Routing  

E-print Network

Multicommodity Flow Algorithms for Buffered Global Routing Christoph Albrecht, Andrew B. Kahng, Ion on a multicommodity flow formulation for the buffered global routing problem. Multicommodity flow based global routing to be a distinct advantage of multicommodity flow based methods over all other approaches to global routing

Zelikovsky, Alexander

290

Deletion of the anion exchanger Slc26a4 (pendrin) decreases apical Cl(-)/HCO3(-) exchanger activity and impairs bicarbonate secretion in kidney collecting duct.  

PubMed

The anion exchanger Pendrin, which is encoded by SLC26A4 (human)/Slc26a4 (mouse) gene, is localized on the apical membrane of non-acid-secreting intercalated (IC) cells in the kidney cortical collecting duct (CCD). To examine its role in the mediation of bicarbonate secretion in vivo and the apical Cl(-)/HCO(3)(-) exchanger in the kidney CCD, mice with genetic deletion of pendrin were generated. The mutant mice show the complete absence of pendrin expression in their kidneys as assessed by Northern blot hybridization, Western blot, and immunofluorescence labeling. Pendrin knockout (KO) mice display significantly acidic urine at baseline [pH 5.20 in KO vs. 6.01 in wild type (WT); P < 0.0001] along with elevated serum HCO(3)(-) concentration (27.4 vs. 24 meq/l in KO vs. WT, respectively; P < 0.02), consistent with decreased bicarbonate secretion in vivo. The urine chloride excretion was comparable in WT and KO mice. For functional studies, CCDs were microperfused and IC cells were identified by their ability to trap the pH fluorescent dye BCECF. The apical Cl(-)/HCO(3)(-) exchanger activity in B-IC and non-A, non-B-IC cells, as assessed by intracellular pH monitoring, was significantly reduced in pendrin-null mice. The basolateral Cl(-)/HCO(3)(-) exchanger activity in A-IC cells and in non-A, non-B-IC cells, was not different in pendrin KO mice relative to WT animals. Urine NH(4)(+) (ammonium) excretion increased significantly, consistent with increased trapping of NH(3) in the collecting duct in pendrin KO mice. We conclude that Slc26a4 (pendrin) deletion impairs the secretion of bicarbonate in vivo and reduces apical Cl(-)/HCO(3)(-) exchanger activity in B-IC and non-A, non-B-IC cells in CCD. Additional apical Cl(-)/HCO(3)(-) exchanger(s) is (are) present in the CCD. PMID:20375274

Amlal, Hassane; Petrovic, Snezana; Xu, Jie; Wang, Zhaohui; Sun, Xuming; Barone, Sharon; Soleimani, Manoocher

2010-07-01

291

Effects of Cathodic Potential, Bicarbonate, and Chloride Ions on SCC of X70 Pipeline Steel  

NASA Astrophysics Data System (ADS)

This is an investigation on the stress corrosion cracking (SCC) behavior of X70 pipeline steel in high pH carbonate-bicarbonate solutions with different concentrations of bicarbonate and chloride ions and at cathodic potential of -1100 mV versus saturated calomel electrode (SCE) using slow strain rate testing. Electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy were used to investigate the electrochemical behavior of X70 pipeline steel in solutions with different concentrations. X70 pipeline steel fracture surface morphology in these different solutions was also studied by scanning electron microscopy (SEM). The results suggested that the susceptibility to SCC for X70 pipeline steel decreased in the most dilute carbonate-bicarbonate solution in the absence of the chloride ion. Also, at potential of -1100 mV versus SCE, all fracture surfaces showed semi-brittle behavior with transgranular cracks.

Shahriari, A.; Shahrabi, T.; Oskuie, A. A.

2013-05-01

292

Crystal structure of human soluble adenylate cyclase reveals a distinct, highly flexible allosteric bicarbonate binding pocket.  

PubMed

Soluble adenylate cyclases catalyse the synthesis of the second messenger cAMP through the cyclisation of ATP and are the only known enzymes to be directly activated by bicarbonate. Here, we report the first crystal structure of the human enzyme that reveals a pseudosymmetrical arrangement of two catalytic domains to produce a single competent active site and a novel discrete bicarbonate binding pocket. Crystal structures of the apo protein, the protein in complex with ?,?-methylene adenosine 5'-triphosphate (AMPCPP) and calcium, with the allosteric activator bicarbonate, and also with a number of inhibitors identified using fragment screening, all show a flexible active site that undergoes significant conformational changes on binding of ligands. The resulting nanomolar-potent inhibitors that were developed bind at both the substrate binding pocket and the allosteric site, and can be used as chemical probes to further elucidate the function of this protein. PMID:24616449

Saalau-Bethell, Susanne M; Berdini, Valerio; Cleasby, Anne; Congreve, Miles; Coyle, Joseph E; Lock, Victoria; Murray, Christopher W; O'Brien, M Alistair; Rich, Sharna J; Sambrook, Tracey; Vinkovic, Mladen; Yon, Jeff R; Jhoti, Harren

2014-04-01

293

Survival after an amniotic fluid embolism following the use of sodium bicarbonate.  

PubMed

Amniotic fluid embolism (AFE) is a rare and potentially fatal complication of pregnancy. In this case report, we highlight the successful use of sodium bicarbonate in a patient with an AFE. We present a case of a 38-year-old mother admitted for an elective caesarean section. Following the delivery of her baby, the mother suffered a cardiac arrest. Following a protracted resuscitation, transoesophageal echocardiography demonstrated evidence of acute pulmonary hypertension, with an empty left ventricle and an over-distended right ventricle. In view of these findings and no improvement noted from on-going resuscitation, sodium bicarbonate was infused as a pulmonary vasodilator. Almost instantaneous return of spontaneous circulation was noted, with normalisation of cardiac parameters. We propose that in patients suspected with AFE and who have been unresponsive to advance cardiac life support measures, and where right ventricular failure is present with acidosis and/or hypercarbia, the use of sodium bicarbonate should be considered. PMID:24879737

Evans, Sorcha; Brown, Brigid; Mathieson, Matthew; Tay, Stan

2014-01-01

294

Tetra­methyl­ammonium hydrogen terephthalate  

PubMed Central

The asymmetric unit of the title salt, C4H12N+·C8H5O4 ?, contains one half of a tetra­methyl­ammonium cation and one half of a hydrogen terephthalate monoanion. The N atom of the ammonium cation lies on a twofold rotation axis and the centre of mass of the terephthalate anion is on a centre of inversion. In the crystal, the centrosymmetric terephthalate ions are linked by a very short symmetric O—H?O hydrogen bond [O?O = 2.4610?(19)?Å] into a one-dimensional polymeric chain along [1-12]. The tetra­methyl­ammonium cations and terephthalate anions are then connected through a pair of bifurcated acceptor C—H?O hydrogen bonds, generating a three-dimensional supra­molecular network. The carboxyl­ate groups at both ends of the terephthalate anion are charge-shared with an equal probability of 0.5. PMID:23125785

Dolatyari, Leila; Shoghpour Bayraq, Samad; Sharifi, Sara; Ramazani, Ali; Morsali, Ali; Amiri Rudbari, Hadi

2012-01-01

295

[Mechanical buffering characteristics of feline paw pads].  

PubMed

In the long time of natural evolution, the bodies of some animals, such as feline, that live in the wild and complicate surroundings have evolved to possess outstanding buffering characteristics, which make the animals adapt to the environment perfectly. These animals generally have well-developed paw pads under their soles to play an important role in attenuating the intensity of impact when they land on the ground. Investigating the buffering characteristics of these animals' paw pads could help us to design "bionic" buffering and energy-absorption devices. In this paper, based on observations of animal jumping test, a simple mass-spring-buffer model was proposed to explore the buffering characteristics of the animals' paw pads. By analytically solving the differential equations of this model, the parameters concerned with paw pads functions were discussed and some significant results were obtained. PMID:23469538

Zhang, Xiaopeng; Yang, Jialing; Yu, Hui

2012-12-01

296

Bicarbonate kinetics and predicted energy expenditure in critically ill children2  

PubMed Central

Background: To determine nutrient requirements by the carbon oxidation techniques, it is necessary to know the fraction of carbon dioxide produced during the oxidative process but not excreted. This fraction has not been described in critically ill children. By measuring the dilution of 13C infused by metabolically produced carbon dioxide, the rates of carbon dioxide appearance can be estimated. Energy expenditure can be determined by bicarbonate dilution kinetics if the energy equivalents of carbon dioxide (food quotient) from the diet ingested are known. Objective: We conducted a 6-h, primed, continuous tracer infusion of NaH13CO3 in critically ill children fed parenterally or enterally or receiving only glucose and electrolytes, to determine bicarbonate fractional recovery, bicarbonate rates of appearance, and energy expenditure. Design: Thirty-one critically ill children aged 1 mo–20 y who were admitted to a pediatric intensive care unit at a tertiary-care center were studied. Patients were stratified by age, BMI, and severity score (PRISM III). Results: Fractional bicarbonate recovery was 0.69, 0.70, and 0.63, respectively, for the parenterally fed, enterally fed, and glucose-electrolytes groups, and it correlated with the severity of disease in the parenteral (P < 0.01) and glucose-electrolytes (P < 0.05) groups. Rates of appearance varied between 0.17 and 0.19 ?mol · kg?1 · h?1 With these data and estimates of the energy equivalents of carbon dioxide (a surrogate for respiratory quotient), energy expenditure was determined. Conclusions: The 2001 World Health Organization and Schofield predictive equations overestimated and underestimated, respectively, energy requirements compared with those obtained by bicarbonate dilution kinetics. Bicarbonate kinetics allows accurate determination of energy needs in critically ill children. PMID:18689369

Sy, Jama; Gourishankar, Anand; Gordon, William E; Griffin, Debra; Zurakowski, David; Roth, Rachel M; Coss-Bu, Jorge; Jefferson, Larry; Heird, William; Castillo, Leticia

2008-01-01

297

Supercritical water oxidation of ammonium picrate  

SciTech Connect

This study demonstrates the feasibility of using supercritical water oxidation to destroy ammonium picrate. Analyses of reactor effluent composition at various temperatures, residence times, and oxidant concentrations were used to design an improved reactor configuration for achieving destruction with minimum corrosion. The engineering evaluation reactor, a room-sized laboratory scale reactor, was reconfigured to incorporate this design change. Destruction of ammonium picrate with minimized corrosion was demonstrated on this reconfigured reactor. Factors that must be considered in scaling up to pilot plant size are discussed.

LaJeunesse, C.A.; Mills, B.E.; Brown, B.G.

1994-11-01

298

Eutectic composite explosives containing ammonium nitrate  

SciTech Connect

The eutectic of ammonium nitrate (AN), the ammonium salt of 3,5-dinitro-1,2,4-triazole was prepared and its sensitivity and performance were studied. It was found that this AN formulation was unusual in that it performed ideally at small diameter, which indicated that it was a monomolecular explosive. Sensitivity tests included type 12 impact, Henkin thermal and wedge tests, and performance tests included rate stick/plate dent, cylinder, and aquarium tests. Results were compared with calculations, standard explosives, and another eutectic, ethylendiamine dinitrate (EDD)/AN.

Stinecipher, M.M.

1981-01-01

299

On the evaporation of ammonium sulfate solution  

SciTech Connect

Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 {+-} 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor-liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly.

Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

2009-07-16

300

On the evaporation of ammonium sulfate solution  

PubMed Central

Aqueous evaporation and condensation kinetics are poorly understood, and uncertainties in their rates affect predictions of cloud behavior and therefore climate. We measured the cooling rate of 3 M ammonium sulfate droplets undergoing free evaporation via Raman thermometry. Analysis of the measurements yields a value of 0.58 ± 0.05 for the evaporation coefficient, identical to that previously determined for pure water. These results imply that subsaturated aqueous ammonium sulfate, which is the most abundant inorganic component of atmospheric aerosol, does not affect the vapor–liquid exchange mechanism for cloud droplets, despite reducing the saturation vapor pressure of water significantly. PMID:19861551

Drisdell, Walter S.; Saykally, Richard J.; Cohen, Ronald C.

2009-01-01

301

Aluminium transfer in bicarbonate dialysis using a sorbent regenerative system: an in vitro study.  

PubMed

Because of the known presence of aluminium oxide in the Redy cartridge and the increased solubility of aluminium (A1) in alkaline solution, an in vitro study was performed to measure the release of A1 from the Redy cartridge and its potential transfer across a dialyser membrane. The use of bicarbonate rinsed Redy cartridges was associated with significant release of A1 and its subsequent transfer across the cellulose acetate membrane. Bicarbonate dialysis with the Redy system is not recommended for maintenance haemodialysis. PMID:7243771

Branger, B; Ramperez, P; Marigliano, N; Mion, H; Shaldon, S; Mion, C

1980-01-01

302

High temperature attack of ores by means of a liquor essentially containing a soluble bicarbonate  

SciTech Connect

A process for the oxidizing attack at high temperature of ores containing at least one metal belonging to the group formed by uranium, vanadium and molybdenum, by means of an aqueous liquor containing a majority of sodium bicarbonate and a minority of sodium carbonate according to a ratio by weight of sodium bicarbonate to sodium carbonate of at least 1.5, in the presence of free oxygen injected into the reaction medium, this medium being maintained at a temperature of between 160/sup 0/C and 300/sup 0/C. For at most six hours.

Bosca, B.; Maurel, P.; Nicolas, F.

1981-10-20

303

Association of Serum Bicarbonate Levels With Gait Speed and Quadriceps Strength in Older Adults  

PubMed Central

BACKGROUND Metabolic acidosis is associated with skeletal muscle proteolysis, and alkali supplementation has demonstrated improvements in lean body mass and urinary nitrogen wasting in several studies. However, the association of acidosis with functional outcomes has not been examined on a population-based level. STUDY DESIGN Cross-sectional study. SETTING & PARTICIPANTS 2,675 nationally representative adults 50 years of age and older in the National Health and Nutrition Examination Survey 1999 – 2002. FACTOR Serum bicarbonate level. OUTCOMES Low gait speed (gait speed) and low peak torque (peak torque) were defined as being in the lowest sex-specific quartile of gait speed and peak torque, respectively. MEASUREMENTS Serum bicarbonate was measured in all participants. gait speed was determined from a 20-foot timed walk. peak torque was calculated using peak isokinetic knee extensor force. RESULTS Serum bicarbonate <23 mEq/L was present in 22.7% of the cohort. Compared to participants with bicarbonate ?23 mEq/L, those with bicarbonate <23 mEq/L had higher body-mass index and serum albumin, were more likely to have low socioeconomic status, a diagnosis of diabetes mellitus, or glomerular filtration rate <60 mL/min/1.73 m2, and were less likely to use diuretics. Serum bicarbonate <23 mEq/L, compared with ?23 mEq/L, was associated with low gait speed (OR, 1.43; 95% confidence interval (CI), 1.04 – 1.95) and low peak torque (OR, 1.36; 95% CI, 1.07 – 1.74) after multivariable adjustment. The association with low peak torque was modified by race/ethnicity among women but not men (ORs of 1.52 (95% CI 1.08 – 2.13) for men, 2.33 (95% CI 1.23 – 4.44) for non- white women, and 0.93 (95% CI 0.47 – 1.82) for white women). LIMITATIONS Cross-sectional study using a single measurement of bicarbonate. CONCLUSIONS Lower serum bicarbonate levels are associated with slower gait speed and reduced quadriceps strength in older adults. Further studies should examine the effect of alkali therapy on functional outcomes. PMID:21354683

Abramowitz, Matthew K.; Hostetter, Thomas H.; Melamed, Michal L.

2011-01-01

304

40 CFR 415.240 - Applicability; description of the ammonium chloride production subcategory.  

Code of Federal Regulations, 2010 CFR

... Applicability; description of the ammonium chloride production subcategory. 415...MANUFACTURING POINT SOURCE CATEGORY Ammonium Chloride Production Subcategory § 415.240 Applicability; description of the ammonium chloride production subcategory....

2010-07-01

305

21 CFR 180.37 - Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin.  

...false Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. 180...37 Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. ...additives saccharin, ammonium saccharin, calcium saccharin, and sodium...

2014-04-01

306

21 CFR 180.37 - Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin.  

Code of Federal Regulations, 2013 CFR

...false Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. 180...37 Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. ...additives saccharin, ammonium saccharin, calcium saccharin, and sodium...

2013-04-01

307

21 CFR 180.37 - Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin.  

Code of Federal Regulations, 2012 CFR

...false Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. 180...37 Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin. ...additives saccharin, ammonium saccharin, calcium saccharin, and sodium...

2012-04-01

308

Erythrocyte lysis in isotonic solution of ammonium chloride: theoretical modeling and experimental verification.  

PubMed

A mathematical model of erythrocyte lysis in isotonic solution of ammonium chloride is presented in frames of a statistical approach. The model is used to evaluate several parameters of mature erythrocytes (volume, surface area, hemoglobin concentration, number of anionic exchangers on membrane, elasticity and critical tension of membrane) through their sphering and lysis measured by a scanning flow cytometer (SFC). SFC allows measuring the light-scattering pattern (indicatrix) of an individual cell over the angular range from 10 degrees to 60 degrees . Comparison of the experimentally measured and theoretically calculated light scattering patterns allows discrimination of spherical from non-spherical erythrocytes and evaluation of volume and hemoglobin concentration for individual spherical cells. Three different processes were applied for erythrocytes sphering: (1) colloid osmotic lysis in isotonic solution of ammonium chloride, (2) isovolumetric sphering in the presence of sodium dodecyl sulphate and albumin in neutrally buffered isotonic saline, and (3) osmotic fragility test in hypotonic media. For the hemolysis in ammonium chloride, the evolution of distributions of sphered erythrocytes on volume and hemoglobin content was monitored in real-time experiments. The analysis of experimental data was performed in the context of a statistical approach, taking into account that parameters of erythrocytes vary from cell to cell. PMID:18083194

Chernyshev, Andrey V; Tarasov, Peter A; Semianov, Konstantin A; Nekrasov, Vyacheslav M; Hoekstra, Alfons G; Maltsev, Valeri P

2008-03-01

309

Transcriptional Responses of a Bicarbonate-Tolerant Monocot, Puccinellia tenuiflora, and a Related Bicarbonate-Sensitive Species, Poa annua, to NaHCO3 Stress.  

PubMed

Puccinellia tenuiflora is an alkaline salt-tolerant monocot found in saline-alkali soil in China. To identify the genes which are determining the higher tolerance of P. tenuiflora compared to bicarbonate sensitive species, we examined the responses of P. tenuiflora and a related bicarbonate-sensitive Poeae plant, Poa annua, to two days of 20 mM NaHCO3 stress by RNA-seq analysis. We obtained 28 and 38 million reads for P. tenuiflora and P. annua, respectively. For each species, the reads of both unstressed and stressed samples were combined for de novo assembly of contigs. We obtained 77,329 contigs for P. tenuiflora and 115,335 contigs for P. annua. NaHCO3 stress resulted in greater than two-fold absolute expression value changes in 157 of the P. tenuiflora contigs and 1090 of P. annua contigs. Homologs of the genes involved in Fe acquisition, which are important for the survival of plants under alkaline stress, were up-regulated in P. tenuiflora and down-regulated in P. annua. The smaller number of the genes differentially regulated in P. tenuiflora suggests that the genes regulating bicarbonate tolerance are constitutively expressed in P. tenuiflora. PMID:25551599

Kobayashi, Shio; Satone, Hina; Tan, Engkong; Kurokochi, Hiroyuki; Asakawa, Shuichi; Liu, Shenkui; Takano, Tetsuo

2014-01-01

310

Transcriptional Responses of a Bicarbonate-Tolerant Monocot, Puccinellia tenuiflora, and a Related Bicarbonate-Sensitive Species, Poa annua, to NaHCO3 Stress  

PubMed Central

Puccinellia tenuiflora is an alkaline salt-tolerant monocot found in saline-alkali soil in China. To identify the genes which are determining the higher tolerance of P. tenuiflora compared to bicarbonate sensitive species, we examined the responses of P. tenuiflora and a related bicarbonate-sensitive Poeae plant, Poa annua, to two days of 20 mM NaHCO3 stress by RNA-seq analysis. We obtained 28 and 38 million reads for P. tenuiflora and P. annua, respectively. For each species, the reads of both unstressed and stressed samples were combined for de novo assembly of contigs. We obtained 77,329 contigs for P. tenuiflora and 115,335 contigs for P. annua. NaHCO3 stress resulted in greater than two-fold absolute expression value changes in 157 of the P. tenuiflora contigs and 1090 of P. annua contigs. Homologs of the genes involved in Fe acquisition, which are important for the survival of plants under alkaline stress, were up-regulated in P. tenuiflora and down-regulated in P. annua. The smaller number of the genes differentially regulated in P. tenuiflora suggests that the genes regulating bicarbonate tolerance are constitutively expressed in P. tenuiflora. PMID:25551599

Kobayashi, Shio; Satone, Hina; Tan, Engkong; Kurokochi, Hiroyuki; Asakawa, Shuichi; Liu, Shenkui; Takano, Tetsuo

2014-01-01

311

Control of Citrus Green Mold by Carbonate and Bicarbonate Salts and the Influence of Commercial Postharvest Practices on Their Efficacy  

Microsoft Academic Search

Smilanick, J. L., Margosan, D. A., Mlikota, F., Usall, J., and Michael, I. F. 1999. Control of citrus green mold by carbonate and bicarbonate salts and the influence of commercial posthar- vest practices on their efficacy. Plant Dis. 83: 139-145. The toxicity to Penicillium digitatum and practical use of carbonate and bicarbonate salts to control green mold were determined. The

Joseph L. Smilanick; Dennis A. Margosan; Franka Mlikota; Josep Usall; Ibrahim F. Michael

1999-01-01

312

416 Biochimica et Biophysica Aeta, 766 (1984) 416 -423 EVIDENCE FROM THERMOLUMINESCENCE FOR BICARBONATE ACTION ON THE  

E-print Network

THERMOLUMINESCENCE FOR BICARBONATE ACTION ON THE RECOMBINATION REACTIONS INVOLVING THE SECONDARY QUINONE ELECTRON) (Received March 12th, 1984) Key words: Thermoluminescence; Photosynthesis; Photosystem II; Bicarbonate on thermoluminescence from isolated thylakoids to probe the recombination reactions of S2 (or possibly $3) with Q~ or QA

Govindjee

313

Lower serum bicarbonate and a higher anion gap are associated with lower cardiorespiratory fitness in young adults  

PubMed Central

Lower levels of serum bicarbonate and a higher anion gap have been associated with insulin resistance and hypertension in the general population. Whether these associations extend to other cardiovascular disease risk factors is unknown. To clarify this, we examined the association of serum bicarbonate and anion gap with cardiorespiratory fitness in 2714 adults aged 20–49 years in the 1999–2004 National Health and Nutrition Examination Survey. The mean serum bicarbonate was 24.6 mEq/L and the mean anion gap was 10.26 mEq/L, with fitness determined by submaximal exercise testing. After multivariable adjustment, gender, length of fasting, soft drink consumption, systolic blood pressure, serum phosphate, and hemoglobin were independently associated with both the serum bicarbonate and the anion gap. Low fitness was most prevalent among those in the lowest quartile of serum bicarbonate or highest quartile of anion gap. After multivariable adjustment, a one standard deviation higher serum bicarbonate or anion gap was associated with an odds ratio for low fitness of 0.80 (95% CI 0.70–0.91) and 1.30 (95% CI 1.15–1.48), respectively. The association of bicarbonate with fitness may be mediated by differences in lean body mass. Thus, lower levels of serum bicarbonate and higher levels of anion gap are associated with lower cardiorespiratory fitness in adults aged 20–49 years in the general population. PMID:22297677

Abramowitz, Matthew K.; Hostetter, Thomas H.; Melamed, Michal L.

2012-01-01

314

Permeation of ammonia across bilayer lipid membranes studied by ammonium ion selective microelectrodes.  

PubMed Central

Ammonium ion and proton concentration profiles near the surface of a planar bilayer lipid membrane (BLM) generated by an ammonium ion gradient across the BLM are studied by means of microelectrodes. If the concentration of the weak base is small compared with the buffer capacity of the medium, the experimental results are well described by the standard physiological model in which the transmembrane transport is assumed to be limited by diffusion across unstirred layers (USLs) adjacent to the membrane at basic pH values (pH > pKa) and by the permeation across the membrane itself at acidic pH values. In a poorly buffered medium, however, these predictions are not fulfilled. A pH gradient that develops within the USL must be taken into account under these conditions. From the concentration distribution of ammonium ions recorded at both sides of the BLM, the membrane permeability for ammonia is determined for BLMs of different lipid composition (48 x 10(-3) cm/s in the case of diphytanoyl phosphatidylcholine). A theoretical model of weak electrolyte transport that is based on the knowledge of reaction and diffusion rates is found to describe well the experimental profiles under any conditions. The microelectrode technique can be applied for the study of the membrane permeability of other weak acids or bases, even if no microsensor for the substance under study is available, because with the help of the theoretical model the membrane permeability values can be estimated from pH profiles alone. The accuracy of such measurements is limited, however, because small changes in the equilibrium constants, diffusion coefficients, or concentrations used for computations create a systematic error. PMID:9129821

Antonenko, Y N; Pohl, P; Denisov, G A

1997-01-01

315

Electrophoretic mobilities of erythrocytes in various buffers  

NASA Technical Reports Server (NTRS)

The calibration of space flight equipment depends on a source of standard test particles, this test particle of choice is the fixed erythrocyte. Erythrocytes from different species have different electrophoretic mobilities. Electrophoretic mobility depends upon zeta potential, which, in turn depends upon ionic strength. Zeta potential decreases with increasing ionic strength, so cells have high electrophoretic mobility in space electrophoresis buffers than in typical physiological buffers. The electrophoretic mobilities of fixed human, rat, and rabbit erythrocytes in 0.145 M salt and buffers of varying ionic strength, temperature, and composition, to assess the effects of some of the unique combinations used in space buffers were characterized. Several effects were assessed: glycerol or DMSO (dimethylsulfoxide) were considered for use as cryoprotectants. The effect of these substances on erythrocyte electrophoretic mobility was examined. The choice of buffer depended upon cell mobility. Primary experiments with kidney cells established the choice of buffer and cryoprotectant. A nonstandard temperature of EPM in the suitable buffer was determined. A loss of ionic strength control occurs in the course of preparing columns for flight, the effects of small increases in ionic strength over the expected low values need to be evaluated.

Plank, L. D.; Kunze, M. E.; Todd, P. W.

1985-01-01

316

A novel structure of optical buffer  

NASA Astrophysics Data System (ADS)

Optical buffers are critical for low packet-loss probability in future photonic packet-switched networks. In particular, they would be required to store packets during rate conversion and header processing, and to overcome the receiver's bottleneck. They would be required for queuing packets while transmitters await access to the network. In this paper, we present a novel structure of optical buffer with compact size. This kind of optical buffer is based on a collinear 3x3 fiber coupler in which three fibers are completely in the same plane and weakly coupled. A SOA is used as its nonlinear element as well as an amplifier in it.The experiment result will be also given in the paper. Storage results obtained with this novel structure optical buffer at 100Mb/s will be presented first and then its capacity is extended to higher data rates of 2.5Gb/s, more compatible with present optical networks. Storage has been observed for time up to 1.568ms(more than 32 circulations) in both cases without obvious degration. The novel structure of optical buffer could be a more compact device which makes it possible to be integrated in a chip. SOA in the buffer is used as a nonlinear element as well as an amplifier to compensate loss in the buffer loop. The buffer needs low control power for switch operation. It is easy to control 'write' and 'erase' operation because the same TOAD switch in the buffer can be used for both 'write' and 'erase' operation.

Liu, AiMing; Wu, Chongqing; Gao, Huali; Gong, Yandong; Shum, Ping

2005-02-01

317

Near infrared detection of ammonium minerals.  

USGS Publications Warehouse

Diagnostic near-infrared spectral features have been identified for minerals with ammonium (NH4+) bound in the crystal structure. Near-infrared detection of NH4-bearing minerals may provide useful information for prospecting for certain ore deposits and may provide a better understanding of the nitrogen cycle within geologic environments.-from Authors

Krohn, M.D.; Altaner, S.P.

1987-01-01

318

Diamond Head Revisited with Ammonium Dichromate.  

ERIC Educational Resources Information Center

The classroom demonstration using ammonium dichromate to simulate a volcanic eruption can be modified into a more dramatic and accurate representation of the geologic processes involved in the formation of a volcanic crater. The materials, demonstration setup, safety procedures, and applications to instruction are presented. (Author/WB)

Arrigoni, Edward

1981-01-01

319

Mixed Crystals of Ice and Ammonium Fluoride  

Microsoft Academic Search

THE ``inability of forming solid solutions with any compound'' was attributed to water two years ago by Mironov and Bergman1, who refuted previous reports by Giguere and Maass2 and by Kubaschewski and Weber3 of the solubility of hydrogen peroxide in ice. Yet Kathleen Lonsdale4 directed attention to the fact that ice and ammonium fluoride are not only isomorphous but also

R. Brill; S. Zaromb

1954-01-01

320

MECHANISM BY WHICH AMMONIUM FERTILIZERS KILL LARKSPUR  

Technology Transfer Automated Retrieval System (TEKTRAN)

Environmental concerns of using pesticides on public lands have greatly reduced the use of herbicides to control tall larkspur (Delphinium barbeyi). Alternative methods of control have used ammonium sulfate placed in the crown of individual plants to kill larkspur. The objective of this study was ...

321

76 FR 46907 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...CBSNews.com, Fertilizer Used in Terror Bombs (Apr. 14, 2004), http...ammonium nitrate can be effectively used in bomb-making. By proposing to include a mixture...under this rule mixtures that terrorist bomb-makers would be most interested in...

2011-08-03

322

Ceric ammonium nitrate promoted oxidation of oxazoles.  

PubMed

The ceric ammonium nitrate promoted oxidations of 4,5-diphenyloxazoles and oxazoles with various substitution patterns have been investigated. This transformation results in the formation of the corresponding imide in good yield and tolerates a wide variety of functional groups and substituents on the oxazole moiety. [reaction: see text]. PMID:17107099

Evans, David A; Nagorny, Pavel; Xu, Risheng

2006-11-23

323

21 CFR 73.1298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2011 CFR

...The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing under acidic conditions with sodium...The oxidized product is filtered, washed, and dried. The pigment consists principally of ferric ammonium ferrocyanide...

2011-04-01

324

21 CFR 73.1298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2012 CFR

...The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing under acidic conditions with sodium...The oxidized product is filtered, washed, and dried. The pigment consists principally of ferric ammonium ferrocyanide...

2012-04-01

325

21 CFR 73.1298 - Ferric ammonium ferrocyanide.  

...The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing under acidic conditions with sodium...The oxidized product is filtered, washed, and dried. The pigment consists principally of ferric ammonium ferrocyanide...

2014-04-01

326

21 CFR 73.1298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2013 CFR

...The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing under acidic conditions with sodium...The oxidized product is filtered, washed, and dried. The pigment consists principally of ferric ammonium ferrocyanide...

2013-04-01

327

21 CFR 73.1298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2010 CFR

...The color additive ferric ammonium ferrocyanide is the blue pigment obtained by oxidizing under acidic conditions with sodium...The oxidized product is filtered, washed, and dried. The pigment consists principally of ferric ammonium ferrocyanide...

2010-04-01

328

40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.  

Code of Federal Regulations, 2011 CFR

...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium salt...equivalent of 2-amino-4-(hydroxymethylphosphinyl)butanoic acid, in or on the commodity...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium...

2011-07-01

329

40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.  

Code of Federal Regulations, 2012 CFR

...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium salt...equivalent of 2-amino-4-(hydroxymethylphosphinyl)butanoic acid, in or on the commodity...glufosinate ammonium, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid monoammonium...

2012-07-01

330

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.  

Code of Federal Regulations, 2012 CFR

...false Ammonium nitrate-phosphate fertilizers. 148.220 Section 148.220 ...220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to...phosphate or nitrogen/potash type fertilizers, or complete fertilizers of...

2012-10-01

331

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.  

Code of Federal Regulations, 2011 CFR

...false Ammonium nitrate-phosphate fertilizers. 148.220 Section 148.220 ...220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to...phosphate or nitrogen/potash type fertilizers, or complete fertilizers of...

2011-10-01

332

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.  

...false Ammonium nitrate-phosphate fertilizers. 148.220 Section 148.220 ...220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to...phosphate or nitrogen/potash type fertilizers, or complete fertilizers of...

2014-10-01

333

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.  

Code of Federal Regulations, 2013 CFR

...false Ammonium nitrate-phosphate fertilizers. 148.220 Section 148.220 ...220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to...phosphate or nitrogen/potash type fertilizers, or complete fertilizers of...

2013-10-01

334

PREFERENTIAL AMMONIUM UPTAKE DURING GROWTH CYCLE AND IDENTIFICATION OF AMMONIUM TRANSPORTER GENES IN YOUNG PEAR TREES  

Microsoft Academic Search

Five sequences showing homology with gene coding for ammonium (NH 4) transporters of the subfamily AMT1 (AMT1 genes) involved in the nitrogen (N) uptake process were identified in 2-year-old ‘Rocha’ pear\\/BA29 through reverse transcription polymerase chain reaction (RT-PCR) analysis. Multiple AMT1 genes were expressed in each phase of the growth cycle and results suggest that ammonium uptake is conducted by

Mariana Mota; Cláudia B. Neto; António A. Monteiro; Cristina M. Oliveira

2011-01-01

335

Effects of amounts and types of sodium bicarbonate in wheat flour tortillas  

E-print Network

The effects of different types and amounts of sodium bicarbonate (NBC) were evaluated during the processing of flour tortillas. Fat encapsulated NBC, BS199, BS195, BS193, BS180, BS184, HM50 and HM70, and different particle-sized, non...

Garza Casso, Jessica Beatriz

2007-04-25

336

Calcium and bicarbonate effects on the growth and nutrient uptake of burley tobacco seedlings: Hydroponic culture  

Microsoft Academic Search

In soilless production systems, water quality can have a major impact on the growth of plants. It has become evident that moderately alkaline water is a problem for tobacco transplant growers in some regions of Kentucky. To determine the level of bicarbonate (HCO3 ) alkalinity, which is detrimental to burley tobacco transplants, and to better understand the effect of calcium

Robert C. Pearce; Yongmei Li; Lowell P. Bush

1999-01-01

337

Photosystem II and the unique role of bicarbonate: A historical perspective Dmitriy Shevela a,  

E-print Network

Accepted 6 April 2012 Available online xxxx Keywords: Bicarbonate (hydrogen carbonate) effect Electron years ago, Otto Heinrich Warburg discovered a unique stimulatory role of CO2 in the Hill reaction (i not include any carbon fixation pathway; Warburg used this discovery to support his idea that O2

Govindjee

338

Control of blue mold of apple by combining controlled atmosphere, antagonist mixtures and sodium bicarbonate  

Technology Transfer Automated Retrieval System (TEKTRAN)

'Golden Delicious' apples were wound-inoculated with Penicillium expansum, treated with various combinations of sodium bicarbonate and two antagonists, and stored in air or controlled atmosphere (1.4% O2, 3% CO2). The fruit were stored for 2 or 4 months at 1°C. The antagonists survived and their p...

339

CONTROL OF BLUE MOLD OF APPLE BY COMBINING CONTROLLED ATMOSPHERE, ANTAGONIST MIXTURES, AND SODIUM BICARBONATE  

Technology Transfer Automated Retrieval System (TEKTRAN)

'Golden Delicious' apples were wound-inoculated with Penicillium expansum treated with various combinations of sodium bicarbonate and two antagonists, and stored in air or controlled atmosphere (1.4% O2, 3% CO fruit were stored for 4 months at 1ºC. The antagonists survived and their populations inc...

340

Synergistic effect of calcium and bicarbonate in enhancing arsenate release from ferrihydrite  

NASA Astrophysics Data System (ADS)

Many groundwater systems contain anomalously high arsenic concentrations, associated with less than expected retention of As by adsorption to iron (hydr)oxides. Although carbonates are ubiquitous in aquifers, their relationship to arsenate mobilization is not well characterized. This research examines arsenate release from poorly crystalline iron hydroxides in abiotic systems containing calcium and magnesium with bicarbonate under conditions of static and dynamic flow (pH 7.5-8). Aqueous arsenic levels remained low when arsenate-bearing ferrihydrite was equilibrated with artificial groundwater solution containing Ca, Mg, and HCO 3-. In batch titrations in which a solution of Ca and HCO 3- was added repeatedly, the ferrihydrite surface became saturated with adsorbed Ca and HCO 3-, and aqueous As levels increased by 1-2 orders of magnitude. In columns containing Ca or Mg and HCO 3-, As solubility initially mimicked titrations, but then rapidly increased by an additional order of magnitude (reaching 12 ?M As). Separately, calcium chloride and other simple salts did not induce As release, although sodium bicarbonate and lactate facilitated minor As release under flow. Results indicate that adsorption of calcium or magnesium with bicarbonate leads to As desorption from ferrihydrite, to a degree greater than expected from competitive effects alone, especially under dynamic flow. This desorption may be an important mechanism of As mobilization in As-impacted, circumneutral aquifers, especially those undergoing rapid mineralization of organic matter, which induces calcite dissolution and the production of dissolved calcium and bicarbonate.

Saalfield, Samantha L.; Bostick, Benjamin C.

2010-09-01

341

Growth Rate of Marine Microalgal Species using Sodium Bicarbonate for Biofuels  

E-print Network

bicarbonate (NaHCO_(3)) in the growth media as an alternative carbon source to bubbling CO_(2) into the cultures. The second part examined if NaHCO_(3) could act as a lipid trigger in higher (10.0 g/L) concentrations. The microalgae species Dunaliella...

Gore, Matthew

2013-08-05

342

Effect of Prepartum Energy, Body Condition, and Sodium Bicarbonate on Production of Cows in Early Lactation  

Microsoft Academic Search

In trial 1, the effects of dietary energy (102, 131 or 162% of requirement) in the dry period and of sodium bicarbonate (0 or .75% of diet dry matter) in early lactation were assessed with 31 cows in a 3 × 2 factorial arrangement of treatments. Body condition and weight increased linearly with prepartum energy. Dry matter intake and milk

Y. Boisclair; D. G. Grieve; J. B. Stone; O. B. Allen; G. K. Macleod

1986-01-01

343

Experimental Tricyclic Antidepressant Toxicity: A Randomized, Controlled Comparison of Hypertonic Saline Solution, Sodium Bicarbonate, and Hyperventilation  

Microsoft Academic Search

Study objective: We sought to compare the effects of hypertonic sodium chloride solution (HTS), sodium bicarbonate solution, and hyperventilation (HV) on severe tricyclic antidepressant (TCA) toxicity in a swine model. Methods: Twenty-four mixed-breed, domestic swine of either sex were given an intravenous infusion of nortriptyline (NT) until development of both a QRS duration longer than 120 ms and a systolic

James L McCabe; Daniel J Cobaugh; James J Menegazzi; John Fata

1998-01-01

344

A kinetic study of autohydrogenotrophic denitrification at the optimum pH and sodium bicarbonate dose.  

PubMed

In this study the kinetics of autohydrogenotrophic denitrification was studied under optimum solution pH and bicarbonate concentration. The optimal pH and bicarbonate concentration were firstly obtained using a design of experiment (DOE) methodology. For this purpose a total of 11 experiments were carried out. Sodium bicarbonate concentrations ranging of 20-2000 mg/L and pH values from 6.5 to 8.5 were used in the optimization runs. It was found that the pH has a more pronounced effect on the denitrification process as compared to the bicarbonate dose. The developed quadratic model predicted the optimum conditions at pH 8 and 1100 mg NaHCO(3)/L. Using these optimal conditions, the kinetics of denitrification for nitrate and nitrite degradation were investigated in separate experiments. Both processes were found to follow a zero order kinetic model. The ultimate specific degradation rates for nitrate and nitrite remediation were 29.60 mg NO(3)(-)-N/g MLVSS/L and 34.85 mg NO(3)(-)-N/g MLVSS/L respectively, when hydrogen was supplied every 0.5h. PMID:20015639

Ghafari, Shahin; Hasan, Masitah; Aroua, Mohamed Kheireddine

2010-04-01

345

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2010 CFR

...carbon dioxide test system. 862.1160 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Clinical Chemistry Test Systems § 862.1160 Bicarbonate...carbon dioxide test system is a device intended...associated with changes in body acid-base...

2010-04-01

346

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2011 CFR

...carbon dioxide test system. 862.1160 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Clinical Chemistry Test Systems § 862.1160 Bicarbonate...carbon dioxide test system is a device intended...associated with changes in body acid-base...

2011-04-01

347

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2012 CFR

...carbon dioxide test system. 862.1160 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Clinical Chemistry Test Systems § 862.1160 Bicarbonate...carbon dioxide test system is a device intended...associated with changes in body acid-base...

2012-04-01

348

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

...carbon dioxide test system. 862.1160 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Clinical Chemistry Test Systems § 862.1160 Bicarbonate...carbon dioxide test system is a device intended...associated with changes in body acid-base...

2014-04-01

349

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2013 CFR

...carbon dioxide test system. 862.1160 Section...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...Clinical Chemistry Test Systems § 862.1160 Bicarbonate...carbon dioxide test system is a device intended...associated with changes in body acid-base...

2013-04-01

350

Evolutionary aspects of intestinal bicarbonate secretion in fish Josi R. Taylor , Martin Grosell  

E-print Network

Evolutionary aspects of intestinal bicarbonate secretion in fish Josi R. Taylor , Martin Grosell January 2006; accepted 16 January 2006 Abstract Experiments compared intestinal HCO3 - secretion in the intestine of marine teleost Gulf toadfish, Opsanus beta, to representatives of early chondrostean

Grosell, Martin

351

Bicarbonate Ion Transport: A Mechanism for the Acidification of Urine in the Turtle  

Microsoft Academic Search

The uricotelic turtle Pseudemys scripta acidifies the urine to a pH as low as 4 in the urinary bladder. Data in this report show that the mechanism of acidification in this bladder is the transport of bicarbonate ion from lumen to serosa, and that the temperature to which the turtles are adapted prior to the in vitro experiment largely determines

Theodore P. Schilb

1978-01-01

352

40 CFR 721.10430 - Tetra alkyl ammonium salt (generic).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Tetra alkyl ammonium salt (generic). 721.10430 Section 721... § 721.10430 Tetra alkyl ammonium salt (generic). (a) Chemical substance...identified generically as tetra alkyl ammonium salt (PMN P-97-823) is subject to...

2013-07-01

353

21 CFR 172.430 - Iron ammonium citrate.  

...Drugs 3 2014-04-01 2014-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

2014-04-01

354

21 CFR 573.560 - Iron ammonium citrate.  

Code of Federal Regulations, 2012 CFR

...Drugs 6 2012-04-01 2012-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

2012-04-01

355

21 CFR 172.430 - Iron ammonium citrate.  

Code of Federal Regulations, 2012 CFR

...Drugs 3 2012-04-01 2012-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

2012-04-01

356

21 CFR 573.560 - Iron ammonium citrate.  

Code of Federal Regulations, 2013 CFR

...Drugs 6 2013-04-01 2013-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

2013-04-01

357

21 CFR 172.430 - Iron ammonium citrate.  

Code of Federal Regulations, 2010 CFR

...Drugs 3 2010-04-01 2009-04-01 true Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

2010-04-01

358

21 CFR 573.560 - Iron ammonium citrate.  

...Drugs 6 2014-04-01 2014-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

2014-04-01

359

21 CFR 172.430 - Iron ammonium citrate.  

Code of Federal Regulations, 2013 CFR

...Drugs 3 2013-04-01 2013-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

2013-04-01

360

21 CFR 172.430 - Iron ammonium citrate.  

Code of Federal Regulations, 2011 CFR

...Drugs 3 2011-04-01 2011-04-01 false Iron ammonium citrate. 172.430 Section 172.430...HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in...

2011-04-01

361

21 CFR 573.560 - Iron ammonium citrate.  

Code of Federal Regulations, 2011 CFR

...Drugs 6 2011-04-01 2011-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

2011-04-01

362

21 CFR 573.560 - Iron ammonium citrate.  

Code of Federal Regulations, 2010 CFR

...Drugs 6 2010-04-01 2010-04-01 false Iron ammonium citrate. 573.560 Section 573.560...OF ANIMALS Food Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal...

2010-04-01

363

40 CFR 721.6070 - Alkyl phosphonate ammonium salts.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Alkyl phosphonate ammonium salts. 721.6070 Section 721.6070 ...721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant...generically as alkyl phosphonate ammonium salts (PMNs P-93-725 and...

2012-07-01

364

40 CFR 721.6070 - Alkyl phosphonate ammonium salts.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Alkyl phosphonate ammonium salts. 721.6070 Section 721.6070 ...721.6070 Alkyl phosphonate ammonium salts. (a) Chemical substances and significant...generically as alkyl phosphonate ammonium salts (PMNs P-93-725 and...

2010-07-01

365

75 FR 14082 - Ammonium Salts of Fatty Acids (C8  

Federal Register 2010, 2011, 2012, 2013

...EPA-HQ-OPP-2008-0652; FRL-8809-6] Ammonium Salts of Fatty Acids (C 8 -C 18 Saturated...of a tolerance for residues of ammonium salts of fatty acids (C 8 -C 18 saturated...permissible level for residues of ammonium salts of fatty acids (C 8 -C...

2010-03-24

366

STUDIES ON THE EFFECT OF AMMONIUM SULFATE ON CARCINOGENESIS  

EPA Science Inventory

The project was designed to evaluate the health effects of ammonium sulfate (Nh4)2 SO4 inhalation using experimental animals. The questions studied were: (1) Is inhaled ammonium sulfate co-carcinogenic. (2) What are the deposition and clearance patterns of inhaled ammonium sulfat...

367

Thermal Dissociation Kinetics of Solid and Liquid Ammonium Nitrate  

E-print Network

Thermal Dissociation Kinetics of Solid and Liquid Ammonium Nitrate Sergey Vyazovkin,* Jacalyn S and liquid ammonium nitrate. Model-fitting and model-free kinetic methods have been applied to the sets/vaporization. Introduction Ammonium nitrate (AN) finds a widespread applica- tion as both fertilizer and energetic material

Utah, University of

368

Original article Ionic adsorption of ammonium and nitrate on some  

E-print Network

Original article Ionic adsorption of ammonium and nitrate on some animal litters and their role -- Two experiments were carried out to determine the adsorption of ammonium and nitrate on litters (Exp added to the tubes which were incubated for 24 h. Ammonium and nitrate concentrations, and pH, were

Paris-Sud XI, Université de

369

Conversion of Fogwater and Aerosol Organic Nitrogen to Ammonium,  

E-print Network

Conversion of Fogwater and Aerosol Organic Nitrogen to Ammonium, Nitrate, and NOx during Exposure in a slow net loss. Ammonium and nitrate were formed at initial rates on the order of a few micromolar per. Although the formation rates of ammonium and nitrate were relatively small as compared to their initial

Zhang, Qi

370

Competitive Parallel Disk Prefetching and Buffer Management  

E-print Network

We provide a competitive analysis framework for online prefetching and buffer management algorithms in parallel I/O systems, using a read-once model of block references. This has widespread applicability to key I/O-bound applications...

Barve, Rakesh; Kallahalla, Mahesh; Varman, Peter J.; Vitter, Jeffrey Scott

2000-01-01

371

Regulation of Anterior Chamber Drainage by Bicarbonate-sensitive Soluble Adenylyl Cyclase in the Ciliary Body*  

PubMed Central

Glaucoma is a leading cause of blindness affecting as many as 2.2 million Americans. All current glaucoma treatment strategies aim to reduce intraocular pressure (IOP). IOP results from the resistance to drainage of aqueous humor (AH) produced by the ciliary body in a process requiring bicarbonate. Once secreted into the anterior chamber, AH drains from the eye via two pathways: uveoscleral and pressure-dependent or conventional outflow (Ct). Modulation of “inflow” and “outflow” pathways is thought to occur via distinct, local mechanisms. Mice deficient in the bicarbonate channel bestrophin-2 (Best2), however, exhibit a lower IOP despite an increase in AH production. Best2 is expressed uniquely in nonpigmented ciliary epithelial (NPE) cells providing evidence for a bicarbonate-dependent communicative pathway linking inflow and outflow. Here, we show that bicarbonate-sensitive soluble adenylyl cyclase (sAC) is highly expressed in the ciliary body in NPE cells, but appears to be absent from drainage tissues. Pharmacologic inhibition of sAC in mice causes a significant increase in IOP due to a decrease in Ct with no effect on inflow. In mice deficient in sAC IOP is elevated, and Ct is decreased relative to wild-type mice. Pharmacologic inhibition of sAC did not alter IOP or Ct in sAC-deficient mice. Based on these data we propose that the ciliary body can regulate Ct and that sAC serves as a critical sensor of bicarbonate in the ciliary body regulating the secretion of substances into the AH that govern outflow facility independent of pressure. PMID:21994938

Lee, Yong S.; Tresguerres, Martin; Hess, Kenneth; Marmorstein, Lihua Y.; Levin, Lonny R.; Buck, Jochen; Marmorstein, Alan D.

2011-01-01

372

/GaAs (001) Metamorphic Buffer Layers  

NASA Astrophysics Data System (ADS)

The design of metamorphic buffer layers for semiconductor devices with reduced defect densities requires control of lattice relaxation and dislocation dynamics. Graded layers are beneficial for the design of these buffers because they reduce the threading dislocation density by (1) allowing the distribution of the misfit dislocations throughout the buffer layer therefore reducing pinning interactions, and (2) enhancing mobility from the high built-in surface strain which helps to sweep out threading arms. In this work, we considered heterostructures involving a linearly-graded (type A) or step-graded (type B) buffer grown on a GaAs (001) substrate. For each structure type, we studied the equilibrium configuration and the kinetically-limited lattice relaxation and non-equilibrium threading dislocations by utilizing a dislocation dynamics model. In this work, we have also considered heterostructures involving a constant composition ZnS y Se1- y device layer grown on top of a GaAs (001) substrate with an intermediate buffer layer of linearly-graded (type C) or step-graded (type D) ZnS y Se1- y . For each structure type, we studied the requirements on the thickness and compositional profile in the buffer layer for the elimination of all mobile threading dislocations from the device layer by the dislocation compensation mechanism.

Kujofsa, T.; Ayers, J. E.

2014-08-01

373

Liquid-liquid phase separation in particles containing organics mixed with ammonium sulfate, ammonium bisulfate, ammonium nitrate or sodium chloride  

NASA Astrophysics Data System (ADS)

As the relative humidity varies from high to low values in the atmosphere, particles containing organic species and inorganic salts may undergo liquid-liquid phase separation. The majority of the laboratory work on this subject has used ammonium sulfate as the inorganic salt. In the following we studied liquid-liquid phase separation in particles containing organics mixed with the following salts: ammonium sulfate, ammonium bisulfate, ammonium nitrate and sodium chloride. In each experiment one organic was mixed with one inorganic salt and the liquid-liquid phase separation relative humidity (SRH) was determined. Since we studied 23 different organics mixed with four different salts, a total of 92 different particle types were investigated. Out of the 92 types, 49 underwent liquid-liquid phase separation. For all the inorganic salts, liquid-liquid phase separation was never observed when the oxygen-to-carbon elemental ratio (O : C) ≥ 0.8 and was always observed for O : C < 0.5. For 0.5 ≤ O : C < 0.8, the results depended on the salt type. Out of the 23 organic species investigated, the SRH of 20 organics followed the trend: (NH4)2SO4 ≥ NH4HSO4 ≥ NaCl ≥ NH4NO3. This trend is consistent with previous salting out studies and the Hofmeister series. Based on the range of O : C values found in the atmosphere and the current results, liquid-liquid phase separation is likely a frequent occurrence in both marine and non-marine environments.

You, Y.; Renbaum-Wolff, L.; Bertram, A. K.

2013-12-01

374

Low noise buffer amplifiers and buffered phase comparators for precise time and frequency measurement and distribution  

NASA Technical Reports Server (NTRS)

Extremely low noise, high performance, wideband buffer amplifiers and buffered phase comparators were developed. These buffer amplifiers are designed to distribute reference frequencies from 30 KHz to 45 MHz from a hydrogen maser without degrading the hydrogen maser's performance. The buffered phase comparators are designed to intercompare the phase of state of the art hydrogen masers without adding any significant measurement system noise. These devices have a 27 femtosecond phase stability floor and are stable to better than one picosecond for long periods of time. Their temperature coefficient is less than one picosecond per degree C, and they have shown virtually no voltage coefficients.

Eichinger, R. A.; Dachel, P.; Miller, W. H.; Ingold, J. S.

1982-01-01

375

Oxidation of ammonium sulfite in aqueous solutions using ozone technology  

NASA Astrophysics Data System (ADS)

How to deal with unstable ammonium sulfite, the byproduct of flue gas desulfuration by ammonia absorption methods, has been a difficult problem in recent years. Oxidation of ammonium sulfite in aqueous solutions using ozone produced by a surface discharge system was investigated in the paper. The oxidation efficiency of ammonium sulfite by ozone and traditional air aeration were compared, and the factors including ozone concentration, gas flow rate, initial concentration of ammonium sulfite solution and reaction temperature were discussed. The results show that the oxidation efficiency of ammonium sulfite by ozone technology reached nearly 100% under the optimum conditions, which had a significant increase compared with that by air aeration.

Li, Yue; Shang, Kefeng; Lu, Na; Li, Jie; Wu, Yan

2013-03-01

376

Bidirectional diffusion of ammonium and sodium cations in forward osmosis: role of membrane active layer surface chemistry and charge.  

PubMed

Systematic fundamental understanding of mass transport in osmosis-driven membrane processes is important for further development of this emerging technology. In this work, we investigate the role of membrane surface chemistry and charge on bidirectional solute diffusion in forward osmosis (FO). In particular, bidirectional diffusion of ammonium (NH4(+)) and sodium (Na(+)) is examined using FO membranes with different materials and surface charge characteristics. Using an ammonium bicarbonate (NH4HCO3) draw solution, we observe dramatically enhanced cation fluxes with sodium chloride feed solution compared to that with deionized water feed solution for thin-film composite (TFC) FO membrane. However, the bidirectional diffusion of cations does not change, regardless of the type of feed solution, for cellulose triacetate (CTA) FO membrane. We relate this phenomenon to the membrane fixed surface charge by employing different feed solution pH to foster different protonation conditions for the carboxyl groups on the TFC membrane surface. Membrane surface modification is also carried out with the TFC membrane using ethylenediamine to alter carboxyl groups into amine groups. The modified TFC membrane, with less negatively charged groups, exhibits a significant decrease in the bidirectional diffusion of cations under the same conditions employed with the pristine TFC membrane. Based on our experimental observations, we propose Donnan dialysis as a mechanism responsible for enhanced bidirectional diffusion of cations in TFC membranes. PMID:25418020

Lu, Xinglin; Boo, Chanhee; Ma, Jun; Elimelech, Menachem

2014-12-16

377

Effects of sodium bicarbonate and 1,25-dihydroxy-cholecalciferol on calcium and phosphorus balances in the rat  

SciTech Connect

Metabolic balance studies were undertaken to determine whether sodium bicarbonate (NaHCO/sub 3/) supplements (4.5 mmol/day) altered 7-day cumulative calcium (Ca) phosphorus (P) balances in growing rats consuming either a basal diet providing 0.6% Ca and 0.3% P, or this diet plus 1,25-dihydroxycholecalciferol (40 ng 1,25(OH)/sub 2/D/sub 3//day). Feeding bicarbonate lowered urinary Ca but raised fecal Ca so that Ca balance became less positive. However, 1,25(OH)/sub 2/D/sub 3/ increased net absorption of Ca and P to the same degree when given to control rats and rats consuming bicarbonate. Nevertheless, bicarbonate-fed rats had lower net Ca absorption than controls, even when treated with high doses of 1,25(OH)/sub 2/D/sub 3/. Changes in net Ca absorption induced by bicarbonate may occur at a point in the gut distal to the duodenum since duodenal /sup 45/Ca absorption was decreased by bicarbonate feeding. The present results show that bicarbonate consumption depressed net Ca absorption in the rat. The effect appears to be independent of changes in 1,25(OH)/sub 2/D/sub 3/ metabolism because it is manifest in animals receiving high doses of 1,25(OH)/sub 2/D/sub 3/, which stimulate alimentary Ca absorption maximally, and because bicarbonate-fed rats are able to respond normally to exogenous 1,25(OH)/sub 2/D/sub 3/ by increasing their net absorption of Ca and P. In view of this demonstration that NaHCO/sub 3/ supplements elevate fecal Ca loss in the rat, it is suggested that studies should be undertaken to determine whether bicarbonate exerts similar adverse effects on Ca balance in humans.

Goulding, A.; McIntosh, J.; Campbell, D.

1984-04-01

378

Key Physiology of Anaerobic Ammonium Oxidation  

PubMed Central

The physiology of anaerobic ammonium oxidizing (anammox) aggregates grown in a sequencing batch reactor was investigated quantitatively. The physiological pH and temperature ranges were 6.7 to 8.3 and 20 to 43°C, respectively. The affinity constants for the substrates ammonium and nitrite were each less than 0.1 mg of nitrogen per liter. The anammox process was completely inhibited by nitrite concentrations higher than 0.1 g of nitrogen per liter. Addition of trace amounts of either of the anammox intermediates (1.4 mg of nitrogen per liter of hydrazine or 0.7 mg of nitrogen per liter of hydroxylamine) restored activity completely. PMID:10388731

Strous, Marc; Kuenen, J. Gijs; Jetten, Mike S. M.

1999-01-01

379

Detonation Properties of Ammonium Dinitramide (ADN)  

NASA Astrophysics Data System (ADS)

Ammonium Dinitramide, ADN, has a potential as an oxidizer for underwater high explosives. Pure ADN has a large reaction-zone length and shows a strong non-ideal behaviour. The work presented here is an extension of previous work.(Sensitivity and Performance Characterization of Ammonium Dinitramide (ADN). Presented at 11th International Detonation Symposium, Snowmass, CO, 1998.) Experiments for determining the detonation velocity as a function of inverse charge radius and density, reaction-zone length and curvature, and the detonation pressure are presented. Measurements of pressure indicates that no, or weak von-Neumann spike exists, suggesting an immediate chemical decomposition. Experimental data are compared with predicted using thermochemical codes and ZND-theory.

Wätterstam, A.; Östmark, H.; Helte, A.; Karlsson, S.

1999-06-01

380

Bis(tri­ethyl­ammonium) chloranilate  

PubMed Central

In the crystal structure of the title compound [systematic name: bis­(tri­ethyl­ammonium) 2,5-di­chloro-3,6-dioxo­cyclo­hexa-1,4-diene-1,4-diolate], 2C6H16N+·C6Cl2O4 2?, the chloranilate anion lies on an inversion center. The tri­ethyl­ammonium cations are linked on both sides of the anion via bifurcated N—H?(O,O) and weak C—H?O hydrogen bonds to give a centrosymmetric 2:1 aggregate. The 2:1 aggregates are further linked by C—H?O hydrogen bonds into a zigzag chain running along [01-1]. PMID:24427039

Gotoh, Kazuma; Maruyama, Shinpei; Ishida, Hiroyuki

2013-01-01

381

Corrosion and repairs of ammonium carbamate decomposers  

SciTech Connect

Corrosion-erosion problems occurred in the carbon steel base metal of the ammonium carbamate decomposers in an urea extraction process lined with type 316L (UNS S31603) urea grade stainless steel. The cladding was replaced by weld overlay using a semiautomatic gas metal arc welding process. The first layer was alloy 25%Cr-15%Ni-2%Mo (UNS W30923); the second layer was alloy 25%Cr-22%Ni-2%Mo (UNS W31020).

De Romero, M.F.; Galban, J.P. [Pequivan S.A., Maracaibo (Venezuela)

1996-05-01

382

Optical constants of concentrated aqueous ammonium sulfate.  

NASA Technical Reports Server (NTRS)

Using experimental data obtained from applying spectroscopy to a 39-wt-% aqueous ammonium sulfate solution, it is shown that, even though specific aerosol optical constants appear quite accurate, spectral variations may exist as functions of material composition or concentration or both. Prudent users of optical constant data must then include liberal data error estimates when performing calculations or in interpreting spectroscopic surveys of collected aerosol material.

Remsberg, E. E.

1973-01-01

383

Ammonium uptake by nitrogen fixing bacteria  

Microsoft Academic Search

Both the changes in the activities of nitrogenase, glutamine synthetase and glutamate dehydrogenase and in the extracellular and intracellular NH4+ concentrations were investigated during the transition from an NH4+ free medium to one containing NH4+ ions for a continuous culture of Azotobacter vinelandii. If added in amounts causing 80–100% repression of nitrogenase, ammonium acetate, lactate and phosphate are absorbed completely,

D. Kleiner; Lehrstuhl Biochemie

1975-01-01

384

Acclimation and toxicity of high ammonium concentrations to unicellular algae.  

PubMed

A literature review on the effects of high ammonium concentrations on the growth of 6 classes of microalgae suggests the following rankings. Mean optimal ammonium concentrations were 7600, 2500, 1400, 340, 260, 100 ?M for Chlorophyceae, Cyanophyceae, Prymnesiophyceae, Diatomophyceae, Raphidophyceae, and Dinophyceae respectively and their tolerance to high toxic ammonium levels was 39,000, 13,000, 2300, 3600, 2500, 1200 ?M respectively. Field ammonium concentrations <100 ?M would not likely reduce the growth rate of most microalgae. Chlorophytes were significantly more tolerant to high ammonium than diatoms, prymnesiophytes, dinoflagellates, and raphidophytes. Cyanophytes were significantly more tolerant than dinoflagellates which were the least tolerant. A smaller but more complete data set was used to estimate ammonium EC?? values, and the ranking was: Chlorophyceae>Cyanophyceae, Dinophyceae, Diatomophyceae, and Raphidophyceae. Ammonia toxicity is mainly attributed to NH? at pHs >9 and at pHs <8, toxicity is likely associated with the ammonium ion rather than ammonia. PMID:24533997

Collos, Yves; Harrison, Paul J

2014-03-15

385

Allocation of buffers to serial production lines with bottlenecks  

Microsoft Academic Search

The optimal placement of a predetermined amount of buffer capacity in balanced serial production lines is a well-understood problem: in lines with moderate variability, the optimal allocation involves equal numbers of buffers at each site; in lines with severe variability, the equal allocation is modified slightly to place more buffers toward the center of the line. Buffering unbalanced lines is

STEPHEN G. POWELL; DAVID F. PYKE

1996-01-01

386

Pain of Local Anesthetics: Rate of Administration and Buffering  

Microsoft Academic Search

Study objective: To determine the impact of administration rate and buffering on the pain associated with subcutaneous infiltration of lidocaine. Methods: Forty-two adult volunteers employed at a tertiary care center participated in this prospective, single-blinded study. Each subject received four lidocaine injections prepared and administered as follows: slow, buffered (SB); slow, unbuffered (SU); rapid, buffered (RB); rapid, unbuffered (RU). Buffering

Richard J Scarfone; Melinda Jasani; Edward J Gracely

1998-01-01

387

Undergraduate Chemistry Students' Perceptions of and Misconceptions about Buffers and Buffer Problems  

ERIC Educational Resources Information Center

Both upper- and lower-level chemistry students struggle with understanding the concept of buffers and with solving corresponding buffer problems. While it might be reasonable to expect general chemistry students to struggle with this abstract concept, it is surprising that upper-level students in analytical chemistry and biochemistry continue to…

Orgill, MaryKay; Sutherland, Aynsley

2008-01-01

388

Comparative effects of added sodium chloride, ammonium chloride, or potassium bicarbonate in the drinking water of broilers, and feed restriction, on the development of the ascites syndrome.  

PubMed

A hypothesis that the ionic composition of drinking water might affect development of the ascites syndrome in broilers was investigated in two trials. The first trial comprised four groups of 650 male chicks. A control treatment was normal tap water and the other three treatments comprised the addition to the tap water of 1,000 mg/L sodium as NaCl, 5,000 mg/L NH4Cl, or 5,000 mg/L KHCO3, supplied from age 2 to 47 d. At Day 28, equally sized subsets of these groups were moved to individual cages, where they received a severe exposure to ambient cold. The development of the ascites syndrome was monitored by measurements of hematocrit and arterial blood oxygen saturation (PaO2) by oximetry, body weight, and examination of dead birds for cause of death. Mortality from ascites in cold-exposed birds from Days 28 to 47 was 28, 48, 40, and 16% in the tap water, NaCl, NH4Cl, and KHCO3 groups, respectively; only the NaCl mortality was significantly different from the tap water mortality. The KHCO3 treatment increased PaO2 (compared with tap water treatment) at Day 28 by 5.5% and at Day 35 by 10.5%, but not at Day 42. The KHCO3 caused a reduction in body weight, which was 13% less than the tap water group at Day 42, probably due to a chronic toxicity. The second trial specifically examined the same parameters with lower water levels of KHCO3 (3,000 and 1,000 mg/L), in comparison to a 10% feed restriction protocol, in order to clarify whether the increased PaO2 was due to a specific effect of the KHCO3 or was a metabolic manifestation of a reduced growth rate. The 3,000 mg/L KHCO3 treatment had no effect on PaO2, but the 1,000 mg/L treatment augmented PaO2 by 5.3% at Day 35 (but not at Days 28 or 42), without reducing the final body weight. The feed restriction group showed an elevated PaO2 of 5.4% at Day 35 (but not at Days 28 or 42), with no reduction in the final body weight. The inclusion of 1,000 mg/L of KHCO3 into the drinking water of broilers or a temporary 10% feed restriction may be means to augment PaO2. PMID:9733114

Shlosberg, A; Bellaiche, M; Berman, E; Ben David, A; Deeb, N; Cahaner, A

1998-09-01

389

Preparation of Buffers. An Experiment for Quantitative Analysis Laboratory  

NASA Astrophysics Data System (ADS)

In our experience, students who have a solid grounding in the theoretical aspects of buffers, buffer preparation, and buffering capacity are often at a loss when required to actually prepare a buffer in a research setting. However, there are very few published laboratory experiments pertaining to buffers. This laboratory experiment for the undergraduate quantitative analysis lab gives students hands-on experience in the preparation of buffers. By preparing a buffer to a randomly chosen pH value and comparing the theoretical pH to the actual pH, students apply their theoretical understanding of the Henderson-Hasselbalch equation, activity coefficients, and the effect of adding acid or base to a buffer. This experiment gives students experience in buffer preparation for research situations and helps them in advanced courses such as biochemistry where a fundamental knowledge of buffer systems is essential.

Buckley, P. T.

2001-10-01

390

Transformation of sodium bicarbonate and CO2 into sodium formate over NiPd nanoparticle catalyst  

PubMed Central

The present research systematically investigated, for the first time, the transformation of sodium bicarbonate and CO2 into sodium formate over a series of Ni based metal nanoparticles (NPs). Ni NPs and eight NiM (M stands for a second metal) NPs were prepared by a facile wet chemical process and then their catalytic performance were evaluated in sodium bicarbonate hydrogenation. Bimetallic NiPd NPs with a composition of 7:3 were found to be superior for this reaction, which are more active than both pure Ni and Pd NPs. Hot filtration experiment suggested the NPs to be the truly catalytic active species and kinetic analysis indicated the reaction mechanism to be different than most homogeneous catalysts. The enhanced activity of the bimetallic nanoparticles may be attributed to their smaller size and improved stability. PMID:24790945

Wang, Mengnan; Zhang, Jiaguang; Yan, Ning

2013-01-01

391

Methane production from bicarbonate and acetate in an anoxic marine sediment  

NASA Technical Reports Server (NTRS)

Methane production from C-14 labeled bicarbonate and acetate was measured over the top 28 cm of anoxic Cape Lookout Bight sediments during the summer of 1983. The depth distribution and magnitude of summed radioisotopically determined rates compare well with previous measurements of total methane production and the sediment-water methane flux. Methane production from CO2 reduction and acetate fermentation accounts for greater than 80 percent of the total production rate and sediment-water flux. Methane production from bicarbonate was found to occur in all depth intervals sampled except those in the top 2 cm, whereas significant methane production from acetate only occurred at depths below 10 cm where sulfate was exhausted. Acetate provided 20 to 29 percent of the measured methane production integrated over the top 30 cm of the sediments.

Crill, P. M.; Martens, C. S.

1986-01-01

392

Riparian forests buffer panel final report  

SciTech Connect

The Chesapeake Executive Council adopted Directive 94-1 which called upon the Chesapeake Bay Program to develop a set of goals and actions to increase the focus on riparian stewardship and enhance efforts to conserve and restore riparian forest buffers. The Council appointed a panel to recommend a set of policies, recommend an accepted definition of forest buffers, and suggest quantifiable goals. The Panel was a diverse group of thirty-one members, comprised of federal, state, and local government representatives, scientists, land managers, citizens, and farming, development, forest industry, and environmental interests. This report contains our principal findings and recommendations.

NONE

1996-10-01

393

Use of bicarbonate ions as a source of carbon in photosynthesis by Callitriche hermaphroditica  

Microsoft Academic Search

Previous studies on four amphibious species of Callitriche have shown photosynthesis to be restricted to CO2 as an external carbon source. In contrast, we found that C. hermaphroditica, an obligately submerged species, is able to use bicarbonate ions in addition to CO2 as an external source of inorganic carbon for photosynthesis. In pH-drift experiments, the final concentration of CO2 was

Stephen C. Maberly; Tom V. Madsen

2002-01-01

394

Evidence for coupled transport of bicarbonate and sodium in cultured bovine corneal endothelial cells  

Microsoft Academic Search

Summary Usin gintracellular microelectrode technique, the response of the voltageV across the plasma membrane of cultured bovine corneal endothelial cells to changes in sodium and bicarbonate concentrations was investigated. (1) The electrical response to changes in [HCO3-]o(depolarization upon lowering and hyperpolarization upon raising [HCO3-]o) was dependent on sodium. Lithium could fairly well be substituted for sodium, whereas potassium or choline

Thomas J. Jentsch; Svea K. Keller; Marianne Koch; Michael Wiederholt

1984-01-01

395

Anion dependence of electrical effects of bicarbonate and sodium on cultured bovine corneal endothelial cells  

Microsoft Academic Search

Using intracellular microelectrode technique, the effect of anion substitution on the voltage responses to extracellular bicarbonate and sodium was explored in cultured bovine corneal endothelial cells.1.The overall amplitude of voltage changes induced by periodic changes of [HCO3-]0 (depolarization upon removal of HCO3- and hyperpolarization upon readdition) was reduced when Cl- was replaced by organic anions (cyclamate, methylsulfate, benzenesulfonate) or by

Thomas J. Jentsch; Harald Matthes; Svea K. Keller; Michael Wiederholt

1985-01-01

396

The Sorin Bicarbon over 15 years clinical outcomes: multicentre experience in 1704 patients  

Microsoft Academic Search

Objectives: To present the results of a 15-year follow-up of the Sorin Bicarbon prosthesis (SBP) from a European multicentre study. Methods: From 1990 to 1996, a total of 1900 SBPs were implanted in 1704 patients, with a mean age of 59±13 years, as aortic (AVR, 922 patients), mitral (MVR, 586) or mitro-aortic (DVR, 196) valve replacement. Most patients received an

Kasra Azarnoush; François Laborde; Charles de Riberolles

2010-01-01

397

Bicarbonate and phosphate ions protect transferrin from myeloperoxidase-mediated damage  

Microsoft Academic Search

Exposure to hypoehlorous acid (HOd), the main product of the reaction of neutrophil myeloperoxi- dase (MPO), H202, and C1, reportedly decreases apotransferrin's iron binding capacity. Optimal transfer- rin iron binding requires the coexistent binding of anions such as bicarbonate (HC03) near the protein's two iron binding sites. Recently, we found that if HC03 was also present during HOC1 exposure, apotransferrin

Brman L. Edeker; George T. Rasmussen; Bradley E. Brmtmgan

398

Sodium bicarbonate supplementation prevents skilled tennis performance decline after a simulated match  

Microsoft Academic Search

The supplementation of sodium bicarbonate (NaHCO3) could increase performance or delay fatigue in intermittent high-intensity exercise. Prolonged tennis matches result in fatigue, which impairs skilled performance. The aim of this study was to investigate the effect of NaHCO3 supplementation on skilled tennis performance after a simulated match. Nine male college tennis players were recruited for this randomized cross-over, placebo-controlled, double-blind

Ching-Lin Wu; Mu-Chin Shih; Chia-Cheng Yang; Ming-Hsiang Huang; Chen-Kang Chang

2010-01-01

399

Effect of cimetidine and sodium bicarbonate on pancreatic replacement therapy in cystic fibrosis  

Microsoft Academic Search

Fifteen patients with cystic fibrosis and pancreatic insufficiency were studied during four randomised seven day treatment periods in which they received only pancreatic supplement (Pancrelipase, 27 capsules per day) or supplement plus cimetidine (20 mg\\/kg body weight\\/24 h) or sodium bicarbonate (15 g\\/m2\\/24 h) alone or in combination. Dietary intake was not fixed but was restricted to foods of known

P R Durie; L Bell; W Linton; M L Corey; G G Forstner

1980-01-01

400

Epinephrine and sodium bicarbonate during CPR following asphyxial cardiac arrest in rats  

Microsoft Academic Search

Although high-dose epinephrine during CPR improves coronary perfusion pressure (CoPP) and rate of return of spontaneous circulation (ROSC) in some models, its impact on long term outcome (? 72 h) has not been evaluated. Previous studies of sodium bicarbonate (NaHCO3) therapy during CPR indicate that beneficial effects may be dependent on epinephrine (EPI) dose. We hypothesized that EPI and NaHCO3

Robert W. Neumar; Nicholas G. Bircher; Ka Ming Sim; Fung Xiao; Kathy Swales Zadach; Ann Radovsky; Laurence Katz; Ewe Ebmeyer; Peter Safar

1995-01-01

401

Electrochemical behaviour of 1024 mild steel in slightly alkaline bicarbonate solutions  

Microsoft Academic Search

The electrochemical behaviour of 1024 mild steel electrodes is investigated in the presence of 0.05–0.5 M sodium bicarbonate in aqueous solution at pH 8.9 and 25°C. Voltammograms are obtained with a rotating gold ring-mild steel electrode and the effect of the NaHCO3 concentration, the potential limits and the rotation speed of the disc electrode is considered. The voltammograms display an

S. SIMARD; M. DROGOWSKA; H. ME´NARD; L. BROSSARD

1997-01-01

402

The electrochemical behaviour of polycrystalline nickel electrodes in different carbonate-bicarbonate ion-containing solutions  

Microsoft Academic Search

The dissolution and passivation of polycrystalline nickel in carbonate-bicarbonate ion-containing solutions covering wide ranges of pH and electrolyte concentration were investigated by employing voltammetric, galvanostatic and potentiostatic transient techniques. Results obtained with a rotating disc electrode allow the competing reactions related to the active-passive transition to be distinguished through the influence of the potential sweep rate and the rotation speed

A. E. Bohé; J. R. Vilche; A. J. Arvia

1990-01-01

403

Effect of Feeding Sodium and Potassium Bicarbonate on Milk Fat, Rumen pH, and Volatile Fatty Acid Production1  

Microsoft Academic Search

SUM~M:ARY Sodium or potassium bicarbonates (1 lb\\/day) were added to the rations of cows fed grain to appetite and 2 lb. of long or pelleted hay. These bicarbonates prevented the decline in milk fat percentage frequently associated with such rations. The pH of the rumen contents was increased, but the molar proportion of the acids was not appreciably altered. The

R. S. Emery; L. D. Brown

1961-01-01

404

Influence of Dietary Sodium and Potassium Bicarbonate and Total Potassium on Heat-Stressed Lactating Dairy Cows1  

Microsoft Academic Search

Objectives were to study effects of heat stress, 0 or .85% sodium bicarbonate, 0 or 1.0% potassium bicarbonate, and 1.0 or 1.5% total dietary potassium on production and physiological responses of dairy cows. Eighteen lactating Holsteins were assigned to shade (control) or no shade (heat stress) lots continuously for three consecutive 35-day periods and to different dietary treatments each period.

P. L. Schneider; D. K. Beede; C. J. Wilcox; R. J. Collier

1984-01-01

405

A new role for bicarbonate secretion in cervico-uterine mucus release  

PubMed Central

Cervical mucus thinning and release during the female reproductive cycle is thought to rely mainly on fluid secretion. However, we now find that mucus released from the murine reproductive tract critically depends upon concurrent bicarbonate (HCO3?) secretion. Prostaglandin E2 (PGE2)- and carbachol-stimulated mucus release was severely inhibited in the absence of serosal HCO3?, HCO3? transport, or functional cystic fibrosis transmembrane conductance regulator (CFTR). In contrast to mucus release, PGE2- and carbachol-stimulated fluid secretion was not dependent on bicarbonate or on CFTR, but was completely blocked by niflumic acid. We found stimulated mucus release was severely impaired in the cystic fibrosis ?F508 reproductive tract, even though stimulated fluid secretion was preserved. Thus, CFTR mutations and/or poor bicarbonate secretion may be associated with reduced female fertility associated with abnormal mucus and specifically, may account for the increased viscosity and lack of cyclical changes in cervical mucus long noted in women with cystic fibrosis. PMID:20478977

Muchekehu, Ruth W; Quinton, Paul M

2010-01-01

406

Differential responses in pear and quince genotypes induced by Fe deficiency and bicarbonate.  

PubMed

Most of the studies carried out on Fe deficiency condition in arboreous plants have been performed, with the exception of those carried out on plants grown in the field, in hydroponic culture utilizing a total iron depletion growth condition. This can cause great stress to plants. By introducing Fe deficiency induced by the presence of bicarbonate, we found significant differences between Pyrus communis L. cv. Conference and Cydonia oblonga Mill. BA29 and MA clones, characterized by different levels of tolerance to chlorosis. Pigment content and the main protein-pigment complexes were investigated by HPLC and protein gel blot analysis, respectively. While similar changes in the structural organization of photosystems (PSs) were observed in both species under Fe deficiency, a different reorganization of the photosynthetic apparatus was found in the presence of bicarbonate between tolerant and susceptible genotypes, in agreement with the photosynthetic electron transport rate measured in isolated thylakoids. In order to characterize the intrinsic factors determining the efficiency of iron uptake in a tolerant genotype, the main mechanisms induced by Fe deficiency in Strategy I species, such as Fe3+-chelate reductase (EC 1.16.1.7) and H+-ATPase (EC 3.6.3.6) activities, were also investigated. We demonstrate that physiological and biochemical root responses in quince and pear are differentially affected by iron starvation and bicarbonate supply, and we show a high correlation between tolerance and Strategy I activation. PMID:19269060

Donnini, Silvia; Castagna, Antonella; Ranieri, Annamaria; Zocchi, Graziano

2009-07-15

407

Pilot scale-SO{sub 2} control by dry sodium bicarbonate injection and an electrostatic precipitator  

SciTech Connect

A 500 actual cubic feet gas per minute (acfm) pilot-scale SO{sub 2} control study was undertaken to investigate flue gas desulfurization (FGD) by dry sodium sorbents in 400{sup o}F (204.5{sup o}C) flue gases emitted from a coal fired boiler with flue gas concentrations between 350 and 2500 ppm SO{sub 2}. Powdered sodium alkaline reagents were injected into the hot flue gas downstream of the air preheater and the spent reagents were collected using an electrostatic precipitator. Three different sorbents were used: processed sodium bicarbonate of two particle sizes; solution mined sodium bicarbonate, and processed sodium sesquicarbonate. SO{sub 2} concentrations were measured upstream of the reagent injection, 25-ft (7.62 m) downstream of the injection point, and downstream of the electrostatic precipitator. SO{sub 2} collection efficiencies ranged from 40 to 80% using sodium bicarbonate stoichiometric ratios from 0.5 to 3.0. Much of the in-duct SO{sub 2} removal occurred during the first second of reagent reaction time, indicating that the sulfur dioxide-sodium reaction rates may be faster than have been measured for fixed bed measurements reported in the literature.

Pliat, M.J.; Wilder, J.M. [University of Washington, Seattle, WA (United States). Dept. of Civil & Environmental Engineering

2007-10-15

408

Bicarbonate-based Integrated Carbon Capture and Algae Production System with alkalihalophilic cyanobacterium.  

PubMed

An extremely alkalihalophilic cyanobacteria Euhalothece ZM001 was tested in the Bicarbonate-based Integrated Carbon Capture and Algae Production System (BICCAPS), which utilize bicarbonate as carbon source for algae culture and use the regenerated carbonate to absorb CO2. Culture conditions including temperature, inoculation rate, medium composition, pH, and light intensity were investigated. A final biomass concentration of 4.79 g/L was reached in tissue flask culture with 1.0 M NaHCO3/Na2CO3. The biomass productivity of 1.21 g/L/day was achieved under optimal conditions. When pH increased from 9.55 to 10.51, 0.256 M of inorganic carbon was consumed during the culture process. This indicated sufficient carbon can be supplied as bicarbonate to the culture. This study proved that a high biomass production rate can be achieved in a BICCAPS. This strategy can also lead to new design of photobioreactors that provides an alternative supply of CO2 to sparging. PMID:23455223

Chi, Zhanyou; Xie, Yuxiao; Elloy, Farah; Zheng, Yubin; Hu, Yucai; Chen, Shulin

2013-04-01

409

The sodium bicarbonate cotransporter (NBCe1) is essential for normal development of mouse dentition.  

PubMed

Proximal renal tubular acidosis (pRTA) is a syndrome caused by abnormal proximal tubule reabsorption of bicarbonate resulting in metabolic acidosis. Patients with mutations to the SLC4A4 gene (coding for the sodium bicarbonate cotransporter NBCe1), have pRTA, growth delay, ocular defects, and enamel abnormalities. In an earlier report, we provided the first evidence that enamel cells, the ameloblasts, express NBCe1 in a polarized fashion, thereby contributing to trans-cellular bicarbonate transport. To determine whether NBCe1 plays a critical role in enamel development, we studied the expression of NBCe1 at various stages of enamel formation in wild-type mice and characterized the biophysical properties of enamel in NBCe1(-/-) animals. The enamel of NBCe1(-/-) animals was extremely hypomineralized and weak with an abnormal prismatic architecture. The expression profile of amelogenin, a known enamel-specific gene, was not altered in NBCe1(-/-) animals. Our results show for the first time that NBCe1 expression is required for the development of normal enamel. This study provides a mechanistic model to account for enamel abnormalities in certain patients with pRTA. PMID:20529845

Lacruz, Rodrigo S; Nanci, Antonio; White, Shane N; Wen, Xin; Wang, Hongjun; Zalzal, Sylvia F; Luong, Vivian Q; Schuetter, Verna L; Conti, Peter S; Kurtz, Ira; Paine, Michael L

2010-08-01

410

Uranium(VI) interactions with mackinawite in the presence and absence of bicarbonate and oxygen  

USGS Publications Warehouse

Mackinawite, Fe(II)S, samples loaded with uranium (10-5, 10-4, and 10-3 mol U/g FeS) at pH 5, 7, and 9, were characterized using X-ray absorption spectroscopy and X-ray diffraction to determine the effects of pH, bicarbonate, and oxidation on uptake. Under anoxic conditions, a 5 g/L suspension of mackinawite lowered 5 × 10-5 M uranium(VI) to below 30 ppb (1.26 × 10-7 M) U. Between 82 and 88% of the uranium removed from solution by mackinawite was U(IV) and was nearly completely reduced to U(IV) when 0.012 M bicarbonate was added. Near-neighbor coordination consisting of uranium–oxygen and uranium-uranium distances indicates the formation of uraninite in the presence and absence of bicarbonate, suggesting reductive precipitation as the dominant removal mechanism. Following equilibration in air, mackinawite was oxidized to mainly goethite and sulfur and about 76% of U(IV) was reoxidized to U(VI) with coordination of uranium to axial and equatorial oxygen, similar to uranyl. Additionally, uranium-iron distances, typical of coprecipitation of uranium with iron oxides, and uranium-sulfur distances indicating bidentate coordination of U(VI) to sulfate were evident. The affinity of mackinawite and its oxidation products for U(VI) provides impetus for further study of mackinawite as a potential reactive medium for remediation of uranium-contaminated water.

Gallegos, Tanya J.; Fuller, Christopher C.; Webb, Samuel M.; Betterton, William J.

2013-01-01

411

Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium  

PubMed Central

Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss1. However, percentage of total nitrate transformed through complete denitrification accounted for <0–72% of the pore water nitrate reduced. Here, we show that up to 99% of nitrate removal in mangrove sediments is routed through dissimilatory nitrate reduction to ammonium (DNRA). The DNRA process was 2x higher at the relatively pristine site Tuvem compared to the anthropogenically-influenced Divar mangrove ecosystem. In systems receiving low extraneous nutrient inputs, this mechanism effectively conserves and re-circulates N minimizing nutrient loss that would otherwise occur through denitrification. In a global context, the occurrence of DNRA in mangroves has important implications for maintaining N levels and sustaining ecosystem productivity. For the first time, this study also highlights the significance of DNRA in buffering the climate by modulating the production of the greenhouse gas nitrous oxide. PMID:22639727

Fernandes, Sheryl Oliveira; Bonin, Patricia C.; Michotey, Valérie D.; Garcia, Nicole; LokaBharathi, P. A.

2012-01-01

412

Quaternized chitosan (QCS) nanoparticles as a novel delivery system for ammonium glycyrrhizinate.  

PubMed

The aim of this study was to generate a new type of nanoparticles made of quaternized chitosan (QCS) and poly(aspartic acid) via the ionotropic gelation technique and to evaluate their potential for the association and delivery of ammonium glycyrrhizinate (GLA). The effects of the pH value of nanoparticles, QCS molecular weight (Mw) and poly(aspartic acid) concentration on GLA encapsulation were studied. Suitably pH value of nanoparticles, moderate QCS MW, optimal concentration ratio of poly(aspartic acid) and QCS favored higher GLA encapsulation efficiency. The release of GLA from nanoparticles was pH-dependent. Fast release occurred in 0.1 M phosphate buffer solution (PBS, pH = 7.4), while the release was slow in 0.1 M HCl (pH = 1.2). The results showed that the new QCS/poly(aspartic acid) nanoparticles have a promising potential in GLA delivery system. PMID:21137945

Wang, Tie wei; Xu, Qing; Wu, Yan; Zeng, Ai jun; Li, Mingjun; Gao, Hongxia

2010-11-01

413

The design and implementation of the buffer manager for an experimental relational database management system  

E-print Network

buffer management and conventional operating system buffer management are discussed. The main requirements and functions of the buffer manager are described; the buffer set model, the data structures, and the algorithms used to support buffer management...

Li, Zaichun

1994-01-01

414

Ammonium release from a blanket peatland into headwater stream systems.  

PubMed

Hydrochemical sampling of South Pennine (UK) headwater streams draining eroded upland peatlands demonstrates these systems are nitrogen saturated, with significant leaching of dissolved inorganic nitrogen (DIN), particularly ammonium, during both stormflow and baseflow conditions. DIN leaching at sub-catchment scale is controlled by geomorphological context; in catchments with low gully densities ammonium leaching dominates whereas highly gullied catchments leach ammonium and nitrate since lower water tables and increased aeration encourages nitrification. Stormflow flux calculations indicate that: approximately equivalent amounts of nitrate are deposited and exported; ammonium export significantly exceeds atmospheric inputs. This suggests two ammonium sources: high atmospheric loadings; and mineralisation of organic nitrogen stored in peat. Downstream trends indicate rapid transformation of leached ammonium into nitrate. It is important that low-order headwater streams are adequately considered when assessing impacts of atmospheric loads on the hydrochemistry of stream networks, especially with respect to erosion, climate change and reduced precipitation. PMID:22285801

Daniels, S M; Evans, M G; Agnew, C T; Allott, T E H

2012-04-01

415

Comparison of the Kinetic Rate Law Parameters for the Dissolution of Natural and Synthetic Autunite in the Presence of Aqueous Bicarbonate Ions  

SciTech Connect

Bicarbonate is one of the most significant components within the uranium geochemical cycle. In aqueous solutions, bicarbonate forms strong complexes with uranium. As such, aqueous bicarbonate may significantly increase the rate of uranium release from uranium minerals. Quantifying the relationship of aqueous bicarbonate concentration to the rate of uranium release during dissolution is critical to understanding the long-term fate of uranium within the environment. Single-pass flow-through (SPTF) experiments were conducted to estimate the rate of uranium release from Na meta-autunite as a function of bicarbonate (0.0005-0.003 M) under the pH range of 6-11 and a temperature range of 5-60oC. Consistent with the results of previous investigation, the rate of uranium release exhibited minimal dependency on temperature; but were strongly dependent on pH. Increasing aqueous bicarbonate concentrations afforded comparable increases in the rate of release of uranium. Most notably under low pH conditions the aqueous bicarbonate resulted in up to 370 fold increases in the rate of uranium release in relative to the rate of uranium release in the absence of bicarbonate. However, the effect of aqueous bicarbonate on the release of uranium was significantly less under higher pH conditions. It is postulated that at high pH values, surface sites are saturated with carbonate, thus the addition of more bicarbonate would have less effect on uranium release.

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn M.; Idarraga, Melina; Lagos, Leonel; Tansel, Berrin

2013-08-02

416

Parks, Buffer Zones, and Costly Enforcement  

Microsoft Academic Search

The reality of protected area management is that enforcing forest and park boundaries is costly and so most likely incomplete, due in part to the pressures exerted on the boundaries by local people who often have traditionally relied on the park resources. Buffer zones are increasingly being proposed and implemented to protect both forest resources and livelihoods. Developing a spatially-explicit

Elizabeth J. Z. Robinson; Heidi J. Albers

2006-01-01

417

Buffer placement improves when topography is considered  

Technology Transfer Automated Retrieval System (TEKTRAN)

Best Management Practices (BMPs) protect streams by excluding cattle from streambanks and by filtering the run-off flowing from animal heavy use areas like feeding and watering stations. Conservation standards recommend placing buffers and filter strips downslope from heavy use areas, but do not exp...

418

How tendons buffer energy dissipation by muscle  

PubMed Central

To decelerate the body and limbs, muscles actively lengthen to dissipate energy. During rapid energy-dissipating events, tendons buffer the work done on muscle by temporarily storing elastic energy, then releasing this energy to do work on the muscle. This elastic mechanism may reduce the risk of muscle damage by reducing peak forces and lengthening rates of active muscle. PMID:23873133

Roberts, Thomas J.; Konow, Nicolai

2013-01-01

419

Understanding the Science Behind Riparian Forest Buffers  

E-print Network

Understanding the Science Behind Riparian Forest Buffers: Resources for Virginia Landowners #12 Tech, 324 Cheatham Hall, Blacksburg, VA 24061; respectively Understanding the Science Behind Riparian* The riparian area is that area of land located immediately adjacent to streams, lakes, or other surface waters

Liskiewicz, Maciej

420

Virtual Memory o translation lookaside buffer (TLB)  

E-print Network

Virtual Memory o translation lookaside buffer (TLB) o cache o translation is called table walking o table walking done by MMU hardware o may take up to 4 memory reads (plus the actual access) for each virtual memory access o locality makes caching

Biagioni, Edoardo S.

421

Buffer layers on biaxially textured metal substrates  

DOEpatents

A method is disclosed for forming a biaxially textured buffer layer on a biaxially oriented metal substrate by using a sol-gel coating technique followed by pyrolyzing/annealing in a reducing atmosphere. This method is advantageous for providing substrates for depositing electronically active materials thereon.

Shoup, Shara S. (Woodstock, GA); Paranthamam, Mariappan (Knoxville, TN); Beach, David B. (Knoxville, TN); Kroeger, Donald M. (Knoxville, TN); Goyal, Amit (Knoxville, TN)

2001-01-01

422

Understanding the Science Behind Riparian Forest Buffers  

E-print Network

Riparian forests are found adjacent to streams, lakes, and other surface waters. They are characterizedUnderstanding the Science Behind Riparian Forest Buffers: Benefits to Communities and Landowners, Virginia Tech, 324 Cheatham Hall, Blacksburg, VA 24061 Understanding the Science Behind Riparian Forest

Liskiewicz, Maciej

423

Evidence for ammonium-bearing minerals in Ceres  

NASA Technical Reports Server (NTRS)

Evidence for ammonium-bearing minerals was found on the surface of the largest asteroid Ceres. The presence of ammonium-bearing clays suggests that Ceres has experienced a period of alteration by substantial amounts of an ammonium-bearing fluid. The presence of the ammonium-bearing clays does not preclude Ceres maintaining a volatile inventory in the core or in a volatile-rich zone at some distance below the surface. Telescopic observations of Ceres, using the 3.0 meter NASA Infrared telescope facility prompted this reevaluation of its surface mineralogy.

King, T. V. V.; Clark, R. N.; Calvin, W. M.; Sherman, D. M.; Swayze, G. A.; Brown, R. H.

1991-01-01

424

Mutational Analysis of the Candida albicans Ammonium Permease Mep2p Reveals Residues Required for Ammonium Transport and Signaling  

Microsoft Academic Search

The ammonium permease Mep2p mediates ammonium uptake and also induces filamentous growth in the human-pathogenic yeast Candida albicans in response to nitrogen limitation. The C-terminal cytoplasmic tail of Mep2p contains a signaling domain that is not required for ammonium transport but is essential for Mep2p-dependent morphogenesis. Progressive C-terminal truncations showed Y433 to be the last amino acid that is essential

Neelam Dabas; Sabrina Schneider; Joachim Morschhauser

2009-01-01

425

Ammonium removal from concentrated waste streams with the anaerobic ammonium oxidation (Anammox) process in different reactor configurations  

Microsoft Academic Search

Many concentrated wastewater streams produced in food and agro-industry are treated using sludge digestion. The effluent from sludge digestors frequently contains ammonium in high concentrations (up to 2 kg m?3). This ammonium-rich effluent is usually treated by a normal wastewater treatment plant (WWTP). When ammonium removal from this concentrated stream is considered, steam stripping or a combination of two biological

Marc Strous; Eric Van Gerven; Ping Zheng; J. Gijs Kuenen; Mike S. M. Jetten

1997-01-01

426

How does glutamine synthetase activity determine plant tolerance to ammonium?  

PubMed

The wide range of plant responses to ammonium nutrition can be used to study the way ammonium interferes with plant metabolism and to assess some characteristics related with ammonium tolerance by plants. In this work we investigated the hypothesis of plant tolerance to ammonium being related with the plants' capacity to maintain high levels of inorganic nitrogen assimilation in the roots. Plants of several species (Spinacia oleracea L., Lycopersicon esculentum L., Lactuca sativa L., Pisum sativum L. and Lupinus albus L.) were grown in the presence of distinct concentrations (0.5, 1.5, 3 and 6 mM) of nitrate and ammonium. The relative contributions of the activity of the key enzymes glutamine synthetase (GS; under light and dark conditions) and glutamate dehydrogenase (GDH) were determined. The main plant organs of nitrogen assimilation (root or shoot) to plant tolerance to ammonium were assessed. The results show that only plants that are able to maintain high levels of GS activity in the dark (either in leaves or in roots) and high root GDH activities accumulate equal amounts of biomass independently of the nitrogen source available to the root medium and thus are ammonium tolerant. Plant species with high GS activities in the dark coincide with those displaying a high capacity for nitrogen metabolism in the roots. Therefore, the main location of nitrogen metabolism (shoots or roots) and the levels of GS activity in the dark are an important strategy for plant ammonium tolerance. The relative contribution of each of these parameters to species tolerance to ammonium is assessed. The efficient sequestration of ammonium in roots, presumably in the vacuoles, is considered as an additional mechanism contributing to plant tolerance to ammonium nutrition. PMID:16292661

Cruz, C; Bio, A F M; Domínguez-Valdivia, M D; Aparicio-Tejo, P M; Lamsfus, C; Martins-Loução, M A

2006-04-01

427

Buffer optimization in network-on-chip through flow regulation  

E-print Network

buffers is an essential task since buffers are a major source of cost and power consumption. This paper proposes flow regulation and has defined a regulation spectrum as a means for system-on-chip architects to control delay and backlog bounds. The regulation is performed per flow for its peak rate and burstiness. However, many flows may have conflicting regulation requirements due to interferences with each other. Based on the regulation spectrum, this paper optimizes the regulation parameters aiming for buffer optimization. Three timing-constrained buffer optimization problems are formulated, namely, buffer size minimization, buffer variance minimization, and multiobjective optimization, which has both buffer size and variance as minimization objectives. Minimizing buffer variance is also important because it affects the modularity of routers and network interfaces. A realistic case study exhibits 62.8 % reduction of total buffers, 84.3 % reduction of total latency, and 94.4 % reduction on the sum of variances of buffers. Likewise, the experimental results demonstrate similar improvements in the case of synthetic traffic patterns. The optimization algorithm has low run-time complexity, enabling quick exploration of large design spaces. This paper concludes that optimal flow regulation can be a highly valuable instrument for buffer optimization in NoC designs. Index Terms—Buffer size, buffer variance, interior point method, network-on-chip (NoC), optimization problem. I.

Fahimeh Jafari; Zhonghai Lu; Axel Jantsch; Mohammad Hossein Yaghmaee

2010-01-01

428

Quantification of Kinetic Rate Law Parameters of Uranium Release from Sodium Autunite as a Function of Aqueous Bicarbonate Concentrations  

SciTech Connect

ABSTRACT: Hydrogen carbonate is one of the most significant components within the uranium geochemical cycle. In aqueous solutions, hydrogen carbonate forms strong complexes with uranium. As such, aqueous bicarbonate may significantly increase the rate of uranium release from uranium minerals. Quantifying the relationship of aqueous hydrogen carbonate solutions to the rate of uranium release during dissolution is critical to understanding the long-term fate of uranium within the environment. Single-pass flow-through (SPTF) experiments were conducted to estimate the rate of uranium release from Na meta-autunite as a function of bicarbonate solutions (0.0005-0.003 M) under the pH range of 6-11 and temperatures of 5-60oC. Consistent with the results of previous investigation, the rate of uranium release from sodium autunite exhibited minimal dependency on temperature; but were strongly dependent on pH and increasing concentrations of bicarbonate solutions. Most notably at pH 7, the rate of uranium release exhibited 370 fold increases relative to the rate of uranium release in the absence of bicarbonate. However, the effect of increasing concentrations of bicarbonate solutions on the release of uranium was significantly less under higher pH conditions. It is postulated that at high pH values, surface sites are saturated with carbonate, thus the addition of more bicarbonate would have less effect on uranium release. Results indicate the activation energies were unaffected by temperature and bicarbonate concentration variations, but were strongly dependent on pH conditions. As pH increased from 6 to 11, activation energy values were observed to decrease from 29.94 kJ mol-1 to 13.07 kJ mol-1. The calculated activation energies suggest a surface controlled dissolution mechanism.

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn M.; Lagos, Leonel; Tansel, Berrin

2013-09-05

429

Altered cell wall properties are responsible for ammonium-reduced aluminum accumulation in rice roots.  

PubMed

The phytotoxicity of aluminum (Al) ions can be alleviated by ammonium (NH4 (+) ) in rice and this effect has been attributed to the decreased Al accumulation in the roots. Here, the effects of different nitrogen forms on cell wall properties were compared in two rice cultivars differing in Al tolerance. An in vitro Al-binding assay revealed that neither NH4 (+) nor NO3 (-) altered the Al-binding capacity of cell walls, which were extracted from plants not previously exposed to N sources. However, cell walls extracted from NH4 (+) -supplied roots displayed lower Al-binding capacity than those from NO3 (-) -supplied roots when grown in non-buffered solutions. Fourier-transform infrared microspectroscopy analysis revealed that, compared with NO3 (-) -supplied roots, NH4 (+) -supplied roots possessed fewer Al-binding groups (-OH and COO-) and lower contents of pectin and hemicellulose. However, when grown in pH-buffered solutions, these differences in the cell wall properties were not observed. Further analysis showed that the Al-binding capacity and properties of cell walls were also altered by pHs alone. Taken together, our results indicate that the NH4 (+) -reduced Al accumulation was attributed to the altered cell wall properties triggered by pH decrease due to NH4 (+) uptake rather than direct competition for the cell wall binding sites between Al(3+) and NH4 (+) . PMID:25444246

Wang, Wei; Zhao, Xue Qiang; Chen, Rong Fu; Dong, Xiao Ying; Lan, Ping; Ma, Jian Feng; Shen, Ren Fang

2014-12-01

430

Compatibility of buffered uranium carbides with tungsten.  

NASA Technical Reports Server (NTRS)

Results of compatibility tests between tungsten and hyperstoichiometric uranium carbide alloys run at 1800 C for 1000 and 2500 hours. These tests compared tungsten-buffered uranium carbide with tungsten-buffered uranium-zirconium carbide. The zirconium carbide addition appeared to widen the homogeneity range of the uranium carbide, making additional carbon available for reaction. Reaction layers could be formed by either of two diffusion paths, one producing UWC2, while the second resulted in the formation of W2C. UWC2 acts as a diffusion barrier for carbon and slows the growth of the reaction layer with time, while carbon diffusion is relatively rapid in W2C, allowing equilibrium to be reached in less than 2500 hours at a temperature of 1800 C.

Phillips, W. M.

1971-01-01

431

META-ANALYSIS OF NITROGEN REMOVAL IN RIPARIAN BUFFERS  

EPA Science Inventory

Riparian buffer zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Riparian buffer width may be positively related to nitrogen removal effectiveness by influencing nitrog...

432

Detecting buffer overflows using testcase synthesis and code instrumentation  

E-print Network

The research presented in this thesis aims to improve existing approaches to dynamic buffer overflow detection by developing a system that utilizes code instrumentation and adaptive test case synthesis to find buffer ...

Zhivich, Michael A

2005-01-01

433

Efficient buffer design algorithms for production line profit maximization  

E-print Network

A production line is a manufacturing system where machines are connected in series and separated by buffers. The inclusion of buffers increases the average production rate of the line by limiting the propagation of ...

Shi, Chuan, Ph. D. Massachusetts Institute of Technology

2012-01-01

434

THE MASS ACCOMMODATION COEFFICIENT OF AMMONIUM NITRATE AEROSOL. (R823514)  

EPA Science Inventory

The mass transfer rate of pure ammonium nitrate between the aerosol and gas phases was quantified experimentally by the use of the tandem differential mobility analyzer/scanning mobility particle sizer (TDMA/SMPS) technique. Ammonium nitrate particles 80-220 nm in diameter...

435

AMMONIUM SULFATE AND BISULFATE FORMATION IN AIR PREHEATERS  

EPA Science Inventory

The overall goal of this study was to investigate the problems which result from deposition of ammonium sulfates in an air preheater. More specifically, the study had three major objectives. The first was to determine the conditions under which ammonium sulfates are expected to f...

436

Ammonium removal from wastewaters using natural New Zealand zeolites  

Microsoft Academic Search

Ammoniacal nitrogen (ammonia and ammonium) in agricultural wastewaters can promote eutrophication of receiving waters and be potentially toxic to fish and other aquatic life. Zeolites, which are hydrated aluminum?silicate minerals, have an affinity for ammonium ions (NH4 ) and are, therefore, potentially useful in removing this contaminant from wastewaters. The major objectives of this study were to evaluate the capacity

M. L. Nguyen; C. C. Tanner

1998-01-01

437

Evaporation of Ammonium Nitrate Aerosol in a Heated Nephelometer  

E-print Network

Evaporation of Ammonium Nitrate Aerosol in a Heated Nephelometer: Implications for Field scattering coefficient of ammonium nitrate aerosol due to evaporation in a heated nephelometer. Changes in the aerosol scattering coefficient due to evaporation agree with measurements to within 10%. Application

438

Ammonium determination in soil extracts by the salicylate method  

Microsoft Academic Search

An ammonium determination, based on formation of a substituted indophenol with sodiumsalicylate as phenolic reagent, has been reexamined. An increase of 70% in absorbancy compared with existing salicylate methods in soil science, and an increase in reproducibility compared with pre?existing equivalent methods in other disciplines were obtained. The method can be applied satisfactorily for ammonium in 2M KCl soil extracts

A. J. Kempers; A. Zweers

1986-01-01

439

Hydrothermal oxidation of organic wastes using reclaimed ammonium nitrate  

SciTech Connect

Ammonium nitrate is being studied as an alternative for ammonium perchlorate as an oxidizing agent in Department of Defense 1.1 and 1.3 rocket propellants. Use of ammonium nitrate would eliminate the HCl produced by ammonium perchlorate upon thermal decomposition. To stabilize the ammonium nitrate, which suffers from phase instability, potassium dinitramide (KDN) is added. This increased use of ammonium nitrate will ultimately create a need for environmentally responsible processes to reuse ammonium nitrate extracted from demilitarized rocket motors. Ammonium Nitrate was investigated as an oxidizing agent for methanol, acetic acid and phenol. High removal of organic, ammonia and nitrate was achieved at stoichiometric concentrations. The oxidation of ammonia by nitrate was much faster than the oxidation of either methanol or acetic acid. Phenol, however, was in strong competition with ammonia for the oxidizer (nitrate). Nitrogen products included N{sub 2}, N{sub 2}O, NO{sub 2{sup {minus}}} as well as toxic NO and trace amounts of NO{sub 2}. Carbon products were CO{sub 2}, HCO{sub 3{sup {minus}}}, CO{sub 3}{sup 2{minus}}, and CO.

Proesmans, P.I.; Luan, L.; Buelow, S.J.

1996-04-01

440

21 CFR 184.1296 - Ferric ammonium citrate.  

Code of Federal Regulations, 2013 CFR

...of 16.5 to 18.5 percent iron, approximately 9 percent ammonia, and 65 percent citric acid and occurs as reddish brown or garnet red scales or granules or as a brownish-yellowish powder. (2) Ferric ammonium citrate (iron (III) ammonium...

2013-04-01

441

21 CFR 184.1296 - Ferric ammonium citrate.  

...of 16.5 to 18.5 percent iron, approximately 9 percent ammonia, and 65 percent citric acid and occurs as reddish brown or garnet red scales or granules or as a brownish-yellowish powder. (2) Ferric ammonium citrate (iron (III) ammonium...

2014-04-01

442

Racer (Ammonium Nonanoate) weed control evaluation for onions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Racer has been labeled as a herbicide for food use and is currently under consideration as an organic herbicide for organically grown food crops. The main component (40%) of Racer is ammonium nonanoate (ammonium pelargonate), which occurs in nature and primarily formed from biodegradation of higher...

443

Ammonium assimilation in Proteus vulgaris, Bacillus pasteurii , and Sporosarcina ureae  

Microsoft Academic Search

No active uptake of ammonium was detected in Proteus vulgaris, Bacillus pasteurii, and Sporosarcina ureae, which indicates that these bacteria depend on the passive diffusion of ammonia across the cell membrane. In P. vulgaris the glutamine synthetase-glutamate synthase (GS-GOGAT) pathway and glutamate dehydrogenase (GDH) were present, and these enzymes exhibited high affinities for ammonium. In B. pasteurii and S. ureae,

Gerhard Miirsdorf; Heinrich Kaltwasser

1989-01-01

444

Surface Micellization Patterns of Quaternary Ammonium Surfactants on Mica  

E-print Network

Surface Micellization Patterns of Quaternary Ammonium Surfactants on Mica Heather N. Patrick equilibrium structures of adsorbed films of quaternary ammonium surfactants on mica have been investigated never been reported on graphite. Mica is a model hydrophilic surface and has been previously used

Aksay, Ilhan A.

445

Low-temperature hydrothermal reduction of ammonium paratungstate  

NASA Astrophysics Data System (ADS)

Ammonium paratungstate has been found to reduce to an ammonium tungsten bronze when hydrothermally treated at 200°C in nonaqueous solvents, such as acetic acid. It has the hexagonal bronze structure with lattice parameters similar to the high-temperature preparations.

Reis, Kenneth P.; Ramanan, A.; Whittingham, M. Stanley

1991-04-01

446

Ultracompact optical buffers on a silicon chip  

Microsoft Academic Search

On-chip optical buffers based on waveguide delay lines might have significant implications for the development of optical interconnects in computer systems. Silicon-on-insulator (SOI) submicrometre photonic wire waveguides are used, because they can provide strong light confinement at the diffraction limit, allowing dramatic scaling of device size. Here we report on-chip optical delay lines based on such waveguides that consist of

Fengnian Xia; Lidija Sekaric; Yurii Vlasov

2007-01-01

447

Cd free buffer layers for solar cells  

Microsoft Academic Search

CdS layers obtained by chemical bath deposition (CBD) are usually used as buffer layer in chalcogenide based thin film solar cells. However, if good results are obtained, cadmium is toxic for the environment while the break of the physical vapour deposition (PVD) cycle, needed for CBD-CdS, constitutes a bottleneck in the process. Therefore many attempts are under way, all over

J. C. Bernede; M. Zoaeter; S. Marsillak; N. Barreauk; C. Oukld El Moctark; K. Benchouk; A. Khelil

2000-01-01

448

Modeling the decay of ammonium oxidizing bacteria.  

PubMed

A bench-scale sequencing batch reactor was used to study factors affecting the endogenous decay of the ammonium oxidizing biomass (AOB) in different operating conditions. AOB decay was very sensitive to oxygen concentration, and increased up to 0.4 d(-1) for oxygen concentration of 7 mg O(2) L(-1). The decay in anaerobic conditions was shown to be very low (0.03 d(-1)) when compared to literature data. The effect of nitrite and nitrate on AOB decay was also studied. The correlation was quite weak suggesting that both nitrate and nitrite absence had little impact on decay which is contrary to what is typically assumed in some of the existing process models. A simple expression for the decay of AOB was proposed, calibrated and validated using the results of batch kinetic tests and of the continuous sequencing batch reactor monitoring. PMID:20933252

Munz, Giulio; Lubello, Claudio; Oleszkiewicz, Jan A

2011-01-01

449

sup 14 C fixation by leaves and leaf cell protoplasts of the submerged aquatic angiosperm Potamogeton lucens: Carbon dioxide or bicarbonate  

SciTech Connect

Protoplasts were isolated from leaves of the aquatic angiosperm Potamogeton lucens L. The leaves utilize bicarbonate as a carbon source for photosynthesis, and show polarity; that is acidification of the periplasmic space of the lower, and alkalinization of the space near the upper leaf side. At present there are two models under consideration for this photosynthetic bicarbonate utilization process: conversion of bicarbonate into free carbon dioxide as a result of acidification and, second, a bicarbonate-proton symport across the plasma membrane. Carbon fixation of protoplasts was studied at different pH values and compared with that in leaf strips. Using the isotopic disequilibrium technique, it was established that carbon dioxide and not bicarbonate was the form in which DIC actually crossed the plasma membrane. It is concluded that there is probably no true bicarbonate transport system at the plasma membrane of these cells and that bicarbonate utilization in this species apparently rests on the conversion of bicarbonate into carbon dioxide. Experiments with acetazolamide, an inhibitor of periplasmic carbonic anhydrase, and direct measurements of carbonic anhydrase activity in intact leaves indicate that in this species the role of this enzyme for periplasmic conversion of bicarbonate into carbon dioxide is insignificant.

Staal, M.; Elzenga, J.T.M.; Prins, H.B.A. (Univ. of Groningen, Haren (Netherlands))

1989-07-01

450

How Close Is Safe? Buffer Zone Development  

NSDL National Science Digital Library

The effects of volcanoes on both the environment and people are the focus of this investigation. Students are introduced to the term "buffer" and are tasked with creating a possible buffer zone around Mount St. Helens. Students begin by assigning 32 pre-written statements related to volcanoes into categories of cause, effect and human responses. The chart, along with true-color and false-color LandSat images from 1980 and 1999, are used to study the eruption of Mount St. Helens to determine that possible buffer zone. The URL opens to the investigation directory, with links to teacher and student materials, lesson extensions, resources, teaching tips, and assessment strategies. As the first investigation in this module entitled, "Volcanoes- Local Hazard, Global Issue," the teacher's guide will begin with a two-page module overview and list of all standards addressed. This is Investigation 1 of three found in the Grades 5-8 Module 1 of Mission Geography. The Mission Geography curriculum integrates data and images from NASA missions with the National Geography Standards. Each of the three investigations in Module 1, while related, can be done independently.

451

IL-17A Induces Pendrin Expression and Chloride-Bicarbonate Exchange in Human Bronchial Epithelial Cells  

PubMed Central

The epithelium plays an active role in the response to inhaled pathogens in part by responding to signals from the immune system. Epithelial responses may include changes in chemokine expression, increased mucin production and antimicrobial peptide secretion, and changes in ion transport. We previously demonstrated that interleukin-17A (IL-17A), which is critical for lung host defense against extracellular bacteria, significantly raised airway surface pH in vitro, a finding that is common to a number of inflammatory diseases. Using microarray analysis of normal human bronchial epithelial (HBE) cells treated with IL-17A, we identified the electroneutral chloride-bicarbonate exchanger Pendrin (SLC26A4) as a potential mediator of this effect. These data were verified by real-time, quantitative PCR that demonstrated a time-dependent increase in Pendrin mRNA expression in HBE cells treated with IL-17A up to 48 h. Using immunoblotting and immunofluorescence, we confirmed that Pendrin protein expression is increased in IL-17 treated HBE cells and that it is primarily localized to the mucosal surface of the cells. Functional studies using live-cell fluorescence to measure intracellular pH demonstrated that IL-17A induced chloride-bicarbonate exchange in HBE cells that was not present in the absence of IL-17A. Furthermore, HBE cells treated with short interfering RNA against Pendrin showed substantially reduced chloride-bicarbonate exchange. These data suggest that Pendrin is part of IL-17A-dependent epithelial changes and that Pendrin may therefore be a therapeutic target in IL-17A-dependent lung disease. PMID:25141009

Adams, Kelly M.; Abraham, Valsamma; Spielman, Daniel; Kolls, Jay K.; Rubenstein, Ronald C.; Conner, Gregory E.; Cohen, Noam A.; Kreindler, James L.

2014-01-01

452

Effect of Bicarbonate Supplementation on Renal Function and Nutritional Indices in Predialysis Advanced Chronic Kidney Disease  

PubMed Central

Current practice guidelines recommend alkali therapy in patients with chronic kidney disease (CKD) and metabolic acidosis to prevent complications. This study aims to investigate the effect of oral sodium bicarbonate supplementation on the progression of renal function and nutritional indices in patients with predialysis advanced CKD. Forty patients with predialysis stage 5 CKD(estimated glomerular filtration rate, eGFR <15mL/min per 1.73m2) and 40 patients with stage 4 CKD (eGFR 15 to 30mL/min per 1.73m2) who had a total CO2 less than 22mEq/L were assigned into the bicarbonate treatment group or control group for 12 months. In stage 4 CKD, there were significant differences in the changes of eGFR during the study between the treatment group and the control group (-2.30±4.49 versus -6.58±6.32mL/min/1.73m2, p<0.05). However, in stage 5 CKD, there were no significant differences in the change of eGFR during the study between the two groups (-2.10±2.06 versus -3.23±1.95mL/min/1.73 m2).There were no significant differences in the changes of nutritional indices such as albumin, prealbumin, transferrin, total lymphocyte count (TLC), and Ondodera's prognostic nutritional index (OPNI) during the study between the two groups. In stage 5 CKD, there were significant differences in the changes of TLC and OPNI between the two groups. In conclusion, our results demonstrate that bicarbonate supplementation slows the rate of decline of renal function in stage 4 CKD and improves nutritional indices in stage 5 CKD. Alkali therapy in advanced CKD may have beneficial effect on renal function and malnutrition. PMID:25606047

Jeong, Jiwon; Kwon, Soon Kil

2014-01-01

453

Effect of carbohydrate or sodium bicarbonate ingestion on performance during a validated basketball simulation test.  

PubMed

Current recommendations for nutritional interventions in basketball are largely extrapolated from laboratory-based studies that are not sport-specific. We therefore adapted and validated a basketball simulation test relative to competitive basketball games using well-trained basketball players (n = 10), then employed this test to evaluate the effects of two common preexercise nutritional interventions on basketball-specific physical and skilled performance. Specifically, in a randomized and counterbalanced order, participants ingested solutions providing either 75 g carbohydrate (sucrose) 45 min before exercise (Study A; n = 10) or 2 × 0.2 g·kg-1 sodium bicarbonate (NaHCO3) 90 and 20 min before exercise (Study B; n = 7), each relative to appropriate placebos (H2O and 2 × 0.14 g·kg-1 NaCl, respectively). Heart rate, sweat rate, pedometer count, and perceived exertion did not systematically differ between the 60-min basketball simulation test and competitive basketball, with a strong positive correlation in heart rate response (r = .9, p < .001). Preexercise carbohydrate ingestion resulted in marked hypoglycemia (< 3.5 mmol·l-1) throughout the first quarter, coincident with impaired sprinting (+0.08 ± 0.05 second; p = .01) and layup shooting performance (8.5/11 versus 10.3/11 baskets; p < .01). However, ingestion of either carbohydrate or sodium bicarbonate before exercise offset fatigue such that sprinting performance was maintained into the final quarter relative to placebo (Study A: -0.07 ± 0.04 second; p < .01 and Study B: -0.08 ± 0.05 second; p = .02), although neither translated into improved skilled (layup shooting) performance. This basketball simulation test provides a valid reflection of physiological demands in competitive basketball and is sufficiently sensitive to detect meaningful changes in physical and skilled performance. While there are benefits of preexercise carbohydrate or sodium bicarbonate ingestion, these should be balanced against potential negative side effects. PMID:24901305

Afman, Gregg; Garside, Richard M; Dinan, Neal; Gant, Nicholas; Betts, James A; Williams, Clyde

2014-12-01

454

Uranium(VI) interactions with mackinawite in the presence and absence of bicarbonate and oxygen.  

PubMed

Mackinawite, Fe(II)S, samples loaded with uranium (10(-5), 10(-4), and 10(-3) mol U/g FeS) at pH 5, 7, and 9, were characterized using X-ray absorption spectroscopy and X-ray diffraction to determine the effects of pH, bicarbonate, and oxidation on uptake. Under anoxic conditions, a 5 g/L suspension of mackinawite lowered 5 × 10(-5) M uranium(VI) to below 30 ppb (1.26 × 10(-7) M) U. Between 82 and 88% of the uranium removed from solution by mackinawite was U(IV) and was nearly completely reduced to U(IV) when 0.012 M bicarbonate was added. Near-neighbor coordination consisting of uranium-oxygen and uranium-uranium distances indicates the formation of uraninite in the presence and absence of bicarbonate, suggesting reductive precipitation as the dominant removal mechanism. Following equilibration in air, mackinawite was oxidized to mainly goethite and sulfur and about 76% of U(IV) was reoxidized to U(VI) with coordination of uranium to axial and equatorial oxygen, similar to uranyl. Additionally, uranium-iron distances, typical of coprecipitation of uranium with iron oxides, and uranium-sulfur distances indicating bidentate coordination of U(VI) to sulfate were evident. The affinity of mackinawite and its oxidation products for U(VI) provides impetus for further study of mackinawite as a potential reactive medium for remediation of uranium-contaminated water. PMID:23742708

Gallegos, Tanya J; Fuller, Christopher C; Webb, Samuel M; Betterton, William

2013-07-01

455

Effect of bicarbonate supplementation on renal function and nutritional indices in predialysis advanced chronic kidney disease.  

PubMed

Current practice guidelines recommend alkali therapy in patients with chronic kidney disease (CKD) and metabolic acidosis to prevent complications. This study aims to investigate the effect of oral sodium bicarbonate supplementation on the progression of renal function and nutritional indices in patients with predialysis advanced CKD. Forty patients with predialysis stage 5 CKD(estimated glomerular filtration rate, eGFR <15mL/min per 1.73m(2)) and 40 patients with stage 4 CKD (eGFR 15 to 30mL/min per 1.73m(2)) who had a total CO2 less than 22mEq/L were assigned into the bicarbonate treatment group or control group for 12 months. In stage 4 CKD, there were significant differences in the changes of eGFR during the study between the treatment group and the control group (-2.30±4.49 versus -6.58±6.32mL/min/1.73m(2), p<0.05). However, in stage 5 CKD, there were no significant differences in the change of eGFR during the study between the two groups (-2.10±2.06 versus -3.23±1.95mL/min/1.73 m(2)).There were no significant differences in the changes of nutritional indices such as albumin, prealbumin, transferrin, total lymphocyte count (TLC), and Ondodera's prognostic nutritional index (OPNI) during the study between the two groups. In stage 5 CKD, there were significant differences in the changes of TLC and OPNI between the two groups. In conclusion, our results demonstrate that bicarbonate supplementation slows the rate of decline of renal function in stage 4 CKD and improves nutritional indices in stage 5 CKD. Alkali therapy in advanced CKD may have beneficial effect on renal function and malnutrition. PMID:25606047

Jeong, Jiwon; Kwon, Soon Kil; Kim, Hye-Young

2014-12-01

456

Intraoral evaluation of mineralization of cosmetic defects by a toothpaste containing calcium, fluoride, and sodium bicarbonate.  

PubMed

New dual-phase fluoride toothpastes that contain soluble calcium, phosphate, and baking soda have recently been introduced into the market. These toothpastes are designed to fill in small surface defects in tooth enamel and thereby enhance tooth esthetics such as gloss. This two-part study was designed to assess these superficial mineralizing effects from using one of these products compared with an experimental calcium-containing, bicarbonate-free formulation and a conventional fluoride toothpaste using an intraoral model. Enamel specimens with 4 types of defects were mounted into an intraoral appliance and placed in the mouths of volunteers for 1 month. The four types of defects were whitening toothpaste abrasion, coarse abrasion, natural dimpling, and acid etching. Before and after intraoral exposure, scanning electron microscope photographs of the specimens were made. The surface microhardness of the acid-etched specimens also was determined. The volunteers brushed their specimens twice daily with one of three randomly assigned toothpastes. The toothpastes were a two-phase, calcium-containing, bicarbonate-based toothpaste; an experimental, two-phase, calcium-containing, bicarbonate-free toothpaste; and a conventional toothpaste. Only the calcium-containing toothpastes showed unequivocal signs of mineral deposition into surface defects, leading to smoothing of the enamel. All three products significantly increased the hardness of the etched enamel, presumably because of fluoride. However, only the two calcium-containing toothpastes gave significantly greater hardness increases than the conventional toothpaste; the specimens treated with a conventional toothpaste were indistinguishable from those treated with saliva. PMID:15645904

Litkowski, Leonard J; Quinlan, Kathleen B; Ross, David R; Ghassemi, Annahita; Winston, Anthony; Charig, Andrew; Flickinger, Mark; Vorwerk, Linda

2004-09-01

457

Chitosan nanoparticles as a novel delivery system for ammonium glycyrrhizinate.  

PubMed

The ammonium glycyrrhizinate-loaded chitosan nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate anions (TPP). The particle size and zeta potential of nanoparticles were determined, respectively, by dynamic light scattering (DLS) and a zeta potential analyzer. The effects, including chitosan molecular weight, chitosan concentration, ammonium glycyrrhizinate concentration and polyethylene glycol (PEG) on the physicochemical properties of the nanoparticles were studied. These nanoparticles have ammonium glycyrrhizinate loading efficiency. The encapsulation efficiency decreased with the increase of ammonium glycyrrhizinate concentration and chitosan concentration. The introduction of PEG can decrease significantly the positive charge of particle surface. These studies showed that chitosan can complex TPP to form stable cationic nanoparticles for subsequent ammonium glycyrrhizinate loading. PMID:15848008

Wu, Yan; Yang, Wuli; Wang, Changchun; Hu, Jianhua; Fu, Shoukuan

2005-05-13

458

Serum bicarbonate may independently predict acute kidney injury in critically ill patients: An observational study  

PubMed Central

AIM: To explore whether serum bicarbonate at admission to intensive care unit (ICU) predicted development of acute kidney injury (AKI). METHODS: We studied all patients admitted to our ICU over a 2 year period (February 2010 to 2012). The ICU has a case mix of medical and surgical patients excluding cardiac surgical, trauma and neurosurgical patients. We analysed 2035 consecutive patients admitted to ICU during the study period. Data were collected by two investigators independently and in duplicate using a standardised spread sheet to ensure accuracy. Ambiguous data were checked for accuracy where indicated. AKI was defined using the Kidney Disease Improving Global Outcomes criteria. Patients were divided into two groups; patients who developed AKI or those who did not, in order to compare the baseline characteristics, and laboratory and physiologic data of the two cohorts. Regression analysis was used to identify if serum bicarbonate on admission predicted the development of AKI. RESULTS: Of 2036 patients 152 (7.5%) were excluded due to missing data. AKI developed in 43.1% of the patients. The AKI group, compared to the non-AKI group, was sicker based on their lower systolic, diastolic and mean arterial pressures and a higher acute physiology and chronic health evaluation (APACHE) III and SAPS II scores. Moreover, patients who developed AKI had more co-morbidities and a higher proportion of patients who developed AKI required mechanical ventilation. The multi-regression analysis of independent variables showed that serum bicarbonate on admission (OR = 0.821; 95%CI: 0.796-0.846; P < 0.0001), APACHE III (OR = 1.011; 95%CI: 1.007-1.015; P < 0.0001), age (OR = 1.016; 95%CI: 1.008-1.024; P < 0.0001) and presence of sepsis at ICU admission (OR = 2.819; 95%CI: 2.122-23.744; P = 0.004) were each significant independent predictors of AKI. The area under the ROC curve was 0.8 (95%CI: 0.78-0.83), thereby demonstrating that the predictive model has relatively good discriminating power for predicting AKI. CONCLUSION: Serum bicarbonate on admission may independently be used to make a diagnosis of AKI.

Gujadhur, Anuksha; Tiruvoipati, Ravindranath; Cole, Elizabeth; Malouf, Saada; Ansari, Erum Sahid; Wong, Kim

2015-01-01

459

Responses of two ecotypes of Medicago ciliaris to direct and bicarbonate-induced iron deficiency conditions  

Microsoft Academic Search

Our study investigates the effect of iron deficiency on morpho-physiological and biochemical parameters of two Medicago ciliaris ecotypes (Mateur TN11.11 and Soliman TN8.7). Iron deficiency was imposed by making plants grow, either in an iron free or\\u000a by the addition of CaCO3\\/NaHCO3 to the Hoagland nutrient solution. Our results showed that both true and bicarbonate Fe-deficiency induced the characteristic\\u000a iron-chlorosis

Wissal M’sehli; Marta Dell’Orto; Patrizia De Nisi; Silvia Donnini; Chedly Abdelly; Graziano Zocchi; Mohamed Gharsalli

2009-01-01

460

Diphenhydramine Overdose with Intraventricular Conduction Delay Treated with Hypertonic Sodium Bicarbonate and IV Lipid Emulsion.  

PubMed

Diphenhydramine toxicity commonly manifests with antimuscarinic features, including dry mucous membranes, tachycardia, urinary retention, mydriasis, tachycardia, and encephalopathy. Severe toxicity can include seizures and intraventricular conduction delay. We present here a case of a 23-year-old male presenting with recurrent seizures, hypotension and wide complex tachycardia who had worsening toxicity despite treatment with sodium bicarbonate. The patient was ultimately treated with intravenous lipid emulsion therapy that was temporally associated with improvement in the QRS duration. We also review the current literature that supports lipid use in refractory diphenhydramine toxicity. PMID:25493135

Abdi, Amin; Rose, Emily; Levine, Michael

2014-11-01

461

The thermodynamics and kinetics of uranophane dissolution in bicarbonate test solutions  

Microsoft Academic Search

The thermodynamic and kinetic properties of a synthetic uranophane (Ca(H3O)2(UO2)2(SiO4)2 · 3H2O) have been determined from dissolution experiments in test solutions of different bicarbonate concentrations at 25°C. The experiments were performed using batch and continuously stirred tank flow-through reactors. From the experimental data obtained with the batch reactor the solubility constant for the reaction: Ca(H3O)2(UO2)2(SiO4)2 · 3H2O + 6H3O+ ?

Isabel Pérez; Ignasi Casas; Maria Mart??n; Jordi Bruno

2000-01-01

462

40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).  

Code of Federal Regulations, 2010 CFR

...Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section...Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical...polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (PMN P-03-197) is...

2010-07-01

463

40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides...Substances § 721.10154 Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides...chemical substance identified as quaternary ammonium compounds, dicoco...

2010-07-01

464

40 CFR 721.10100 - Dialkyl dimethyl ammonium carbonate (2:1) (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Dialkyl dimethyl ammonium carbonate (2:1) (generic). 721...Substances § 721.10100 Dialkyl dimethyl ammonium carbonate (2:1) (generic). ...identified generically as dialkyl dimethyl ammonium carbonate (2:1) (PMN...

2010-07-01

465

21 CFR 520.310 - Caramiphen ethanedisulfonate and ammonium chloride tablets.  

Code of Federal Regulations, 2010 CFR

...false Caramiphen ethanedisulfonate and ammonium chloride tablets. 520.310 Section...310 Caramiphen ethanedisulfonate and ammonium chloride tablets. (a) Specifications...ethanedisulfonate and 80 milligrams of ammonium chloride.1 1 These...

2010-04-01

466

40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).  

Code of Federal Regulations, 2013 CFR

...polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721...polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance...polyalkylarylphenylether sulfate ammonium salt (PMN P-03-197) is subject to...

2013-07-01

467

40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Quaternary ammonium salt of fluorinated alkylaryl amide. 721...Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl amide. ...identified generically as quaternary ammonium salt of fluorinated alkylaryl amide...

2010-07-01

468

40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).  

Code of Federal Regulations, 2012 CFR

...polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721...polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance...polyalkylarylphenylether sulfate ammonium salt (PMN P-03-197) is subject to...

2012-07-01

469

40 CFR 721.10170 - Polyoxyethylene polyalkylarylphenylether sulfate ammonium salt (generic).  

Code of Federal Regulations, 2011 CFR

...polyalkylarylphenylether sulfate ammonium salt (generic). 721.10170 Section 721...polyalkylarylphenylether sulfate ammonium salt (generic). (a) Chemical substance...polyalkylarylphenylether sulfate ammonium salt (PMN P-03-197) is subject to...

2011-07-01

470

40 CFR 721.10443 - Ethoxylated alkylphenol sulfate, ammonium salt (generic).  

...Ethoxylated alkylphenol sulfate, ammonium salt (generic). 721.10443 Section 721...Ethoxylated alkylphenol sulfate, ammonium salt (generic). (a) Chemical substance...ethoxylated alkylphenol sulfate, ammonium salt (PMN P-01-470) is subject to...

2014-07-01

471

40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Quaternary ammonium salt of fluorinated alkylaryl amide. 721...Substances § 721.9075 Quaternary ammonium salt of fluorinated alkylaryl amide. ...identified generically as quaternary ammonium salt of fluorinated alkylaryl amide...

2011-07-01

472

40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the ammonium nitrate subcategory. 418.40 Section...MANUFACTURING POINT SOURCE CATEGORY Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The...

2010-07-01

473

77 FR 59377 - Solid Agricultural Grade Ammonium Nitrate from Ukraine: Final Results of the Expedited Second...  

Federal Register 2010, 2011, 2012, 2013

...A-823-810] Solid Agricultural Grade Ammonium Nitrate from Ukraine: Final Results...on solid agricultural grade ammonium nitrate from Ukraine. The Department...on solid agricultural grade ammonium nitrate from Ukraine, pursuant to...

2012-09-27

474

78 FR 35258 - Solid Agricultural Grade Ammonium Nitrate from Ukraine: Continuation of Antidumping Duty Order  

Federal Register 2010, 2011, 2012, 2013

...A-823-810] Solid Agricultural Grade Ammonium Nitrate from Ukraine: Continuation...on solid agricultural grade ammonium nitrate from Ukraine would likely lead...Order: Solid Agricultural Grade Ammonium Nitrate from Ukraine, 66 FR...

2013-06-12

475

77 FR 21527 - Ammonium Nitrate From Russia: Correction to Notice of Opportunity To Request Administrative Review  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-821-811] Ammonium Nitrate From Russia: Correction to...orders and inadvertently omitted Ammonium Nitrate from Russia, POR 5/2/2011-3...a correction to include the Ammonium Nitrate from Russia administrative...

2012-04-10

476

40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.  

Code of Federal Regulations, 2012 CFR

...Applicability; description of the ammonium nitrate subcategory. 418.40 Section...MANUFACTURING POINT SOURCE CATEGORY Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The...

2012-07-01

477

40 CFR 721.10154 - Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides, reaction products with silica.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides... § 721.10154 Quaternary ammonium compounds, dicoco alkyldimethyl, chlorides...substance identified as quaternary ammonium compounds, dicoco alkyldimethyl,...

2011-07-01

478

PERFORMANCE ANALYSIS OF NETWORKS OF OPEN ZERO-BUFFER  

E-print Network

to another continuously, without any waiting or buffering of work-in-process, since such waiting would result-in-process inventory and the product must never wait between two operations. As a last example, third generation mobile: A serial zero-buffer queuing network We are interested in zero-buffer multi-server general queueing

Cruz, Frederico

479

Groundwater nitrate following installation of a vegetated riparian buffer  

Technology Transfer Automated Retrieval System (TEKTRAN)

Buffers are often planted along streams to reduce nutrient loss from fields. The purpose of this study was to determine if a vegetated buffer could significantly decrease groundwater nitrate-nitrogen (NO3) concentrations. During 2000 and 2001, a three-part buffer was planted adjacent to a first-ord...

480

Use of GIS to Evaluate Riparian Buffers for Water Quality  

E-print Network

1 1 Use of GIS to Evaluate Riparian Buffers for Water Quality Improvements on a Campus Stream has little to no riparian buffers ­ The several transportation corridors are located throughout riparian buffer along the stream would significantly improved water quality within the stream

Clark, Shirley E.

481

Ammonium metabolism enzymes aid Helicobacter pylori acid resistance.  

PubMed

The gastric pathogen Helicobacter pylori possesses a highly active urease to support acid tolerance. Urea hydrolysis occurs inside the cytoplasm, resulting in the production of NH3 that is immediately protonated to form NH4 (+). This ammonium must be metabolized or effluxed because its presence within the cell is counterproductive to the goal of raising pH while maintaining a viable proton motive force (PMF). Two compatible hypotheses for mitigating intracellular ammonium toxicity include (i) the exit of protonated ammonium outward via the UreI permease, which was shown to facilitate diffusion of both urea and ammonium, and/or (ii) the assimilation of this ammonium, which is supported by evidence that H. pylori assimilates urea nitrogen into its amino acid pools. We investigated the second hypothesis by constructing strains with altered expression of the ammonium-assimilating enzymes glutamine synthetase (GS) and glutamate dehydrogenase (GDH) and the ammonium-evolving periplasmic enzymes glutaminase (Ggt) and asparaginase (AsnB). H. pylori strains expressing elevated levels of either GS or GDH are more acid tolerant than the wild type, exhibit enhanced ammonium production, and are able to alkalize the medium faster than the wild type. Strains lacking the genes for either Ggt or AsnB are acid sensitive, have 8-fold-lower urea-dependent ammonium production, and are more acid sensitive than the parent. Additionally, we found that purified H. pylori GS produces glutamine in the presence of Mg(2+) at a rate similar to that of unadenylated Escherichia coli GS. These data reveal that all four enzymes contribute to whole-cell acid resistance in H. pylori and are likely important for assimilation and/or efflux of urea-derived ammonium. PMID:24936052

Miller, Erica F; Maier, Robert J

2014-09-01

482

PULMONARY FUNCTION IN ELASTASE-TREATED GUINEA PIGS AND RATS EXPOSED TO AMMONIUM SULFATE OR AMMONIUM NITRATE AEROSOLS  

EPA Science Inventory

Three weeks following intratracheal instillations of elastase dissolved in saline, or saline alone, guinea pigs and rats were exposed for 5 or 20 days, 6 hr/day, 5 days/week to filtered room air, 1 mg/cu.m. ammonium sulfate ((NH4)2SO4) or 1 mg/cu.m. ammonium nitrate (NH4NO3) aero...

483

Concentrated Flow through a Riparian Buffer: A Case Study  

NASA Astrophysics Data System (ADS)

Riparian buffers are often used for in-situ treatment of agricultural runoff. Although the benefits of riparian buffers are well recongized, concentration of flow can restrict the efficiency of contaminant removal. This study evaluates flow concentration at a agricultural site near Manhattan, Kansas. Manual and automated GIS analyses of a high-resolution digital elevation model were used to determine the fraction of runoff contributing to each buffer segment. Subsequent simulation of the system in WEPP (Water Erosion and Prediction Project) demonstrates the extent to which flow concentration affects buffer efficiency. Recommendations are presented for the design of adaptive-width buffers.

Young, C. B.; Nogues, J. P.; Hutchinson, S. L.

2005-05-01

484

Metabolic alkalosis in the rat. Evidence that reduced glomerular filtration rather than enhanced tubular bicarbonate reabsorption is responsible for maintaining the alkalotic state.  

PubMed Central

Maintenance of chronic metabolic alkalosis might occur by a reduction in glomerular filtration rate (GFR) without increased bicarbonate reabsorption or, alternatively, by augmentation of bicarbonate reabsorption with a normal GFR. To differentiate these possibilities, free-flow micropuncture was performed in alkalotic Munich-Wistar rats with a glomerular ultrafiltrate total CO2 concentration of 46.5 +/- 0.9 mM (vs. 27.7 +/- 0.9 mM in controls). Alkalotic animals had a markedly reduced single nephron GFR compared with controls (27.4 +/- 1.5 vs. 51.6 +/- 1.6 nl/min) and consequently unchanged filtered load of bicarbonate. Absolute proximal bicarbonate reabsorption in alkalotic animals was similar to controls (981 +/- 49 vs. 1,081 +/- 57 pmol/min), despite a higher luminal bicarbonate concentration, contracted extracellular volume, and potassium depletion. When single nephron GFR during alkalosis was increased toward normal by isohydric volume expansion or in another group by isotonic bicarbonate loading, absolute proximal bicarbonate reabsorption was not substantially augmented and bicarbonaturia developed. To confirm that a fall in GFR occurs during metabolic alkalosis, additional clearance studies were performed. Awake rats were studied before and after induction of metabolic alkalosis associated with varying amounts of potassium and chloride depletion. In all cases, the rise in blood bicarbonate concentration was inversely proportional to a reduction in GFR; filtered bicarbonate load remained normal. In conclusion, a reduction in GFR is proposed as being critical for maintaining chronic metabolic alkalosis in the rat. Constancy of the filtered bicarbonate load allows normal rates of renal bicarbonate reabsorption to maintain the alkalotic state. Images PMID:6853706

Cogan, M G; Liu, F Y

1983-01-01

485

Rapid multislice imaging of hyperpolarized 13C pyruvate and bicarbonate in the heart.  

PubMed

Hyperpolarization of spins via dynamic nuclear polarization (DNP) has been explored as a method to non-invasively study real-time metabolic processes occurring in vivo using (13)C-labeled substrates. Recently, hyperpolarized (13)C pyruvate has been used to characterize in vivo cardiac metabolism in the rat and pig. Conventional 3D spectroscopic imaging methods require in excess of 100 excitations, making it challenging to acquire a full cardiac-gated, breath-held, whole-heart volume. In this article, the development of a rapid multislice cardiac-gated spiral (13)C imaging pulse sequence consisting of a large flip-angle spectral-spatial excitation RF pulse combined with a single-shot spiral k-space trajectory for rapid imaging of cardiac metabolism is described. This sequence permits whole-heart coverage (6 slices, 8.8-mm in-plane resolution) in any plane, allowing imaging of the metabolites of interest, [1-(13)C] pyruvate, [1-(13)C] lactate, and (13)C bicarbonate, within a single breathhold. Pyruvate and bicarbonate cardiac volumes were acquired, while lactate images were not acquired due to low lactate levels in the animal model studied. The sequence was demonstrated with phantom experiments and in vivo testing in a pig model. PMID:20574989

Lau, Angus Z; Chen, Albert P; Ghugre, Nilesh R; Ramanan, Venkat; Lam, Wilfred W; Connelly, Kim A; Wright, Graham A; Cunningham, Charles H

2010-11-01

486

Corrosion-fatigue durability of pipe steel in carbonate-bicarbonate medium  

SciTech Connect

Analysis of the operating conditions of gas mains shows that, along with the static stress, a pipe is subjected to cyclically varying stress with a wide frequency spectrum. These stresses consisting of low and high frequency oscillations may result in small cycle corrosion fatigue of pipes. Carbonate corrosion cracking appears under the specific influence of a carbonate-bicarbonate medium, under the periodic shift of the potential of cathodic polarization in the positive direction, and under stresses statically applied to pipeline areas with damaged insulation. Examination of the fracture hearths caused by carbonate corrosion cracking shows that the cracks are not attached to the stress concentrators, although both types of fractures are topographically similar. Corrosion-fatigue tests were carried out in a carbonate-bicarbonate solution and found that the solution slows down the growth of the corrosion-fatigue cracks, apparently because the crack tip is dulled due to the electrochemical dissolution of metal. The authors conclude that carbonate corrosion cracking is an independent phenonmenon separate from small cycle corrosion cracking.

Abdullin, I.G.; Gareev, A.G.

1994-03-01

487

Bicarbonate content of groundwater in carbonate rock in eastern North America  

USGS Publications Warehouse

In carbonate-rock terrane the most effective solution occurs where soil and vegetative cover facilitate biogenic production and storage of CO2 in the soil until part of it is carried downward in percolating water. Bicarbonate data for groundwater in eastern North America are examined in the light of these conditions, of the CO2 content of soil gas, and of the timing of groundwater recharge relative to seasonal changes in soil temperature. There appears to be no well-marked relation between latitude and bicarbonate content of groundwater in this region. Interplay of all the factors listed above, and of lithology and soil types, is evidently such that under optimum conditions the amount of solution of carbonate rock is roughly comparable, per unit of groundwater recharge, over the region from Ohio to Florida (and, perhaps, to Puerto Rico and Yucatan). Relatively low HCO3 concentrations observed in much of the southern United States are attributed to low production and storage of CO2 in sandy soil that is poor in organic matter. On the other hand, concentrations observed in Ontario, New York and Michigan are markedly higher than is to be expected from interrelations of the factors considered. These high values, apparently anomalous, are attributed in part to solution of granular glacial drift derived largely from carbonate rock. ?? 1976.

Trainer, F.W.; Heath, R.C.

1976-01-01

488

Population of Nitrifying Bacteria and Nitrification in Ammonium Saturated Clinoptilolite  

NASA Technical Reports Server (NTRS)

As humans begin to spend longer periods of time in space, plants will be incorporated into life support systems. Ammonium saturated clinoptilolite is one plant growth substrate but a balance between ammonium and nitrate is needed. A laboratory study was conducted to determine effects of nitrifying bacteria on ammonium concentrations and kinetics of nitrification. Columns containing clinoptilolite substrate amended with nitrifying bacteria obtained from soil enrichment were analyzed weekly for a 90 day period. The enrichment culture initially contained 1 x 10(exp 5) ammonium oxidizing bacteria and 1 x 10(exp 2) nitrite oxidizing bacteria per gram of substrate. Populations of ammonium oxidizing bacteria increased to 1 x 10(exp 6) and nitrite oxidizing bacteria increased to 1 x 10(exp 3) per gram of substrate. The nitrification rate was approximately 0.25mg NO3(-)-N/kg.hr. Experiments were also conducted to enumerate nitrifying bacteria in a clinoptilolite substrate used to grow wheat (Triticum aestivum L.). Seventy days following the initial inoculation with an unknown number of commercial nitrifying bacteria, 1 x 10(exp 5) ammonium oxidizing bacteria per gram of substrate were present. The number of nitrite oxidizing bacteria was between 1 x 10(exp 3) to 10(exp 4) per gram of substrate as measured by the most probable number method. Nitrification rates were approximately 0.20mg NO3(-)-N/kg.hr. Clinoptilolite readily exchanged sufficient concentrations of ammonium to support nitrifying bacteria and they survived well in this medium.

McGilloway, R. L.; Weaver, R. W.; Ming, Douglas W.; Gruener, J.

1999-01-01

489

Soil acidification from atmospheric ammonium sulphate in forest canopy throughfall  

NASA Astrophysics Data System (ADS)

Acid rain commonly has high concentrations of dissolved SO2-4, NH+4 and NO-3. Sulphuric and nitric acids are usually considered to be the acidic components, whereas ammonium has a tendency to increase the pH of rainwater1. Ammonium can be transformed to nitric acid in soil but this source of acidity is generally less important than wet and dry deposition of free acids2,3. Here we describe the occurrence of high concentrations of ammonium in canopy throughfall (rainwater falling through the tree canopy) and stemflow in woodland areas in the Netherlands, resulting in acid inputs to soils two to five times higher than those previously described for acid atmospheric deposition2-5. The ammonium is present as ammonium sulphate, which probably forms by interaction of ammonia (volatilized from manure) with sulphur dioxide (from fossil fuels), on the surfaces of vegetation. After leaching by rainwater the ammonium sulphate reaching the soil oxidizes rapidly to nitric and sulphuric acid, producing extremely low pH values (2.8-3.5) and high concentrations of dissolved aluminium in the non-calcareous soils studied. Deposition of ammonium sulphate on the surfaces of vegetation and its environmental consequences are probably most important in areas with intensive animal husbandry.

van Breemen, N.; Burrough, P. A.; Velthorst, E. J.; van Dobben, H. F.; de Wit, Toke; Ridder, T. B.; Reijnders, H. F. R.

1982-10-01

490

Electrogenic ammonium transport by renal Rhbg.  

PubMed

The recently cloned, non-erythrocyte Rh glycoproteins (Rhbg and Rhcg) are expressed in the intercalated cells of the renal collecting duct. The apical Rhcg and the basolateral Rhbg are likely involved in NH3 and/or NH4+ transport, yet the characteristics of this transport are not yet certain. In this study we investigated the mechanism of NH4+ transport by Rhbg and Rhcg expressed in Xenopus oocytes. We used a two-electrode voltage-clamp and ion-selective microelectrodes to measure NH4+-induced currents (I(NH4)) and changes in pHi, respectively. In oocytes expressing Rhcg, exposure to bath [NH4+] of 2.5-20 mM induced inward currents that were slightly more than those in H2O-injected (control) oocytes. I-V plots in the presence of NH4+ showed a small increase in slope conductance only at positive potentials. On the other hand, in oocytes expressing Rhbg, 5 mM NH4+ induced an inward I(NH4) of -79 nA, decreased pHi (DeltapHi) by 0.13 at a rate (dpHi/dt) of -2 7 x 10(-4) pH/s and depolarized the cell by 45 mV. These changes were significantly more than those in control oocytes. I-V plots in the presence of NH4+ showed substantial increase in conductance. Amiloride (1 mM) inhibited I(NH4), DeltapHi and dpHi/dt in oocytes expressing Rhbg but not in control oocytes. Raising bath [NH4+] in increments from 1 to 20 mM elicited a faster dpHi/dt, a larger decrease in pHi and a larger depolarization. Net NH4+ flux by Rhbg (estimated from dpHi/dt) was proportional to [NH4+] gradient and followed saturation kinetics with an apparent Km of 2.3 mM. Methyl ammonium (5 mM) induced a current of -63 nA in Rhbg oocytes but did not cause any change in control oocytes. These data indicate that: 1) Rhbg transport of NH4+ is electrogenic. 2) Methyl ammonium is transported by Rhbg. 3) NH4+ transport by Rhbg is saturated at high concentrations with Michaelis-Menten kinetics. PMID:16580864

Nakhoul, N L; Schmidt, E; Abdulnour-Nakhoul, S-M; Hamm, L L

2006-01-01

491

Calcium balance and acid-base status of women as affected by increased protein intake and by sodium bicarbonate ingestion13  

Microsoft Academic Search

Six women, aged 38 to 62 yr. participated in a 40-day metabolic study to investigate the effect of level of protein intake and of sodium bicarbonate ingestion on urinary calcium, net calcium balance, net renal acid excretion, and arterialized venous blood pH and bicarbonate ion concentration. The diet contained 44 g protein during the first 16 days and 102 g

Josephine Lutz

492

Channel constituents in synthetic beryl: ammonium  

NASA Astrophysics Data System (ADS)

The infrared spectra and electron paramagnetic resonance (EPR) of channel constituents in beryls synthesized hydrothermally in the presence of NH4Cl were investigated. Two forms of ammonium ion were observed to be incorporated into the c-channel. IR-spectra show the double band at 3295 and 3232cm-1 and two broad bands between 2600 and 3000cm-1 which were assigned to the NH3 molecule and NH4+ ion, respectively. Similar N-H stretching vibrations are also observed in Regency hydrothermal synthetic beryls and can be used to separate these synthetic beryls from their natural counterparts. After ?-irradiation of hydrothermally grown samples at 77 K, the EPR of the NH3+(I) radical was observed. The NH3+(II) radical replaces the NH3+(I) radical when the sample is heated to room temperature. Both the NH3 molecule and the NH3+ radical have their C3 symmetry axes perpendicular to the crystal c-axis. The spin Hamiltonian parameters of the NH3+(I) are axial-symmetric due to the rapid rotation of the radical about the c-axis. The NH3+(II) radical has a low symmetry and shows a hindered rotation because of its shift from the c-axis position and an interaction with the proton in the near neighbourhood. Possible models for the paramagnetic centres are discussed.

Mashkovtsev, R. I.; Solntsev, V. P.

493

Contamination of Ammonium-Based Nutrient Solutions by Nitrifying Organisms and the Conversion of Ammonium to Nitrate.  

PubMed

Conversion of ammonium to nitrate and contamination by nitrifying organisms are often assumed not to be significant in ammonium-based nutrient solutions. To assess this assumption, maize (Zea mays) and pea (Pisum sativum) were grown under greenhouse conditions in aeroponic, hydroponic, and sand-culture systems containing 2 mM ammonium chloride as the sole nitrogen source and evaluated for the activity of contaminating nitrifying organisms. In all three culture systems, root colonization by nitrifying organisms was detected within 5 d, and nitrate was detected in the nutrient solution within 10 d after seedling transfer. In sand culture, solution nitrate concentration reached 0.35 mM by the end of the 17-d experiment. Consistent with the microbial ammonium oxidation sequence, nitrite was detected earlier than nitrate and remained at lower levels throughout the experiment. Nitrate was found in significant quantities in root and shoot tissues from seedlings grown in ammonium-based nutrient solutions in all of the solution culture systems. Maize seedlings grown in an ammonium-based hydroponic system contained nitrate concentrations at 40% of that found in plants grown in nitrate-based solution. Determination of nitrate (or nitrite) levels in the nutrient solution was the weakest indicator of the activity of nitrifying organisms. A bioassay for the presence of nitrifying organisms in combination with tissue analysis for nitrate was a better indicator of microbial conversion of ammonium to nitrate in nutrient solution culture. The results have implications for the use of ammonium-based nutrient solutions to obtain plants suitable for research on induction of nitrate uptake and reduction or for research using solution culture to compare ammonium versus nitrate fertilization. PMID:12231673

Padgett, P. E.; Leonard, R. T.

1993-01-01

494

Convergent Geometry Foam Buffered Direct Drive Experiments*  

NASA Astrophysics Data System (ADS)

A serious concern for directly driven ICF implosions is the asymmetry imparted to the capsule by laser drive non-uniformities, particularly the ``early time imprint'' remaining despite the use of random phase plates and smoothing with spectral dispersion. The use of a foam buffer has been proposed as a means to reduce this imprint. Two types of convergent geometry tests of the technique to correct static nonuniformities have been studied to date; cylindrical implosions at the Trident and Vulcan lasers, and spherical implosions at the NOVA laser, all using 527 nm laser drive. Cylindrical implosions used end on x-ray backlighter imaging of inner surface disruption due an intentional hole in the drive footprint, using 50 mg/cc acyrlate foam with a thin Au preheat layer. Spherical implosions used 50 mg/cc polystyrene foam plus Au to study yield and imploded core symmetry of capsules with and without a foam buffer, in comparison to ``clean 1D'' calculations. For thick enough layers, all cases showed improvement. Details of the experiments and theoretical unpinnings will be shown. *Work performed under US DOE Contract No. W-7405-Eng-36.

Watt, R. G.; Wilson, D. C.; Hollis, R. V.; Gobby, P. L.; Chrien, R. E.; Mason, R. J.; Kopp, R. A.; Willi, O.; Iwase, A.; Barringer, L. H.; Gaillard, R.; Kalantar, D. H.; Lerche, R. A.; MacGowan, B.; Nelson, M.; Phillips, T.; Knauer, J. P.; McKenty, P. W.

1996-11-01

495

Gas migration in MX80 buffer bentonite  

SciTech Connect

Controlled flow-rate gas injection experiments have been performed on pre-compacted samples of KBS-3 specification Mx80 buffer bentonite using helium as a safe replacement for hydrogen. By simultaneously applying a confining pressure and backpressure, specimens were isotropically-consolidated and fully water-saturated under pre-determined effective stress conditions, before injecting gas using a syringe pump. Ingoing and outgoing gas fluxes were monitored. All tests exhibited a conspicuous threshold pressure for breakthrough, somewhat larger than the sum of the swelling pressure and the backpressure. All tests showed a post-peak negative transient leading to steady-state gas flow. Using a stepped history of flow rate, the flow law was shown to be nonlinear. With the injection pump stationary (i.e., zero applied flow rate), gas pressure declined with time to a finite value. When gas flow was reestablished, the threshold value for gas breakthrough was found to be significantly lower than in virgin clay. There is strong evidence to suggest that the capillary pressure for the penetration of interparticle pore space of buffer bentonite is of such a magnitude that normal two-phase flow is impossible. Gas entry and breakthrough is therefore accompanied by the development of microcracks which propagate through the clay from gas source to sink. The experiments suggest that these pathways open under high gas pressure conditions and partially close if gas pressure falls, providing a possible explanation of the nonlinearity of the flow law.

Horseman, S.T.; Harrington, J.F. [British Geological Survey, Nottingham, (United Kingdom). Fluid Process Group; Sellin, P. [Svensk Kaerbraenslehantering AB, Stockholm (Sweden)

1997-12-31

496

Manganese(II) catalyzes the bicarbonate-dependent oxidation of amino acids by hydrogen peroxide and the amino acid-facilitated dismutation of hydrogen peroxide.  

PubMed Central

In bicarbonate/CO2 buffer, Mn(II) and Fe(II) catalyze the oxidation of amino acids by H2O2 and the dismutation of H2O2. As the Mn(II)/Fe(II) ratio is increased, the yield of carbonyl compounds per mole of leucine oxidized is essentially constant, but the ratio of alpha-ketoisocaproate to isovaleraldehyde formed increases, and the fraction of H2O2 converted to O2 increases. In the absence of Fe(II), the rate of Mn(II)-catalyzed leucine oxidation is directly proportional to the H2O2, Mn(II), and amino acid concentrations and is proportional to the square of the HCO3- concentration. The rate of Mn(II)-catalyzed O2 production in the presence of 50 mM alanine or leucine is about 4-fold the rate observed in the absence of amino acids and accounts for about half of the H2O2 consumed; the other half of the H2O2 is consumed in the oxidation of the amino acids. In contrast, O2 production is increased nearly 18-fold by the presence of alpha-methylalanine and accounts for about 90% of the H2O2 consumed. The data are consistent with the view that H2O2 decomposition is an inner sphere (cage-like) process catalyzed by a Mn coordination complex of the composition Mn(II), amino acid, (HCO3-)2. Oxidation o