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1

21 CFR 184.1135 - Ammonium bicarbonate.  

Code of Federal Regulations, 2013 CFR

...bicarbonate (NH4 HCO3 , CAS Reg. No. 1066-33-7) is prepared by reacting gaseous carbon dioxide with aqueous ammonia. Crystals of ammonium bicarbonate are precipitated from solution and subsequently washed and dried. (b) The ingredient...

2013-04-01

2

Respiration Quotient: Estimation During Batch Cultivation in Bicarbonate Buffered Media  

Microsoft Academic Search

The Respiration Quotient (RQ) is a key metabolic parameter for cell cultures and is usually determined from gas analysis only. In bicarbonate buffered media the carbon dioxide balance is affected by accumulation and hence the RQ can not directly be calculated from gas measurements. A Kalman Filter as software sensor that estimates the CER can cope with these buffering capacities

Ronald Neeleman

2001-01-01

3

Physical exercise after induced alkalosis (bicarbonate or Tris-buffer)  

Microsoft Academic Search

Summary  The influence of bicarbonate and Tris-buffer infusions on the performance capacity for maximal, brief exercise (400 m run) was studied using 10 normal males in their twenties. Run time, maximal lactate concentration and heart rate remained unchanged after the buffer infusions. As a result of the induced elevated buffering capacity, the average pH after exercise was about 0.1 unit higher.

W. Kindermann; J. Keul; G. Huber

1977-01-01

4

pH-metric determination of ammonium carbonate and bicarbonate in solutions containing ammonium vanadate  

SciTech Connect

Ammonium carbonate and bicarbonate and ammonium carbonate salts used in hydrometallurgy are characterized by low stability both in solid form and in solutions. The frequently used method of acid-base titration in the presence of a pH indicator is unsuitable in the presence of ions in solution that change color within the investigated pH range. The purpose of this paper is to develop a method of rapid determination of the concentration of ammonium carbonate and bicarbonate in solutions containing ammonium vanadate. The authors used a 0.1 M solution of hydrochloric acid, analytical grade ammonium vanadate, and ammonium carbonate salts, the composition of which approximates real technological solutions. An aliquot portion of the test solution (1-2 ml) is transferred to a 50-ml beaker, and 10 ml of distilled water is added. The electrodes of the pH meter are placed in the solution, and it is titrated with 0.1 M hydrochloric acid with constant mixing.

Fofanov, Al.A.; Yuorenko, V.V.; Kharlampieva, T.I.; Potapov, V.I.

1986-07-01

5

Biocompatibility and buffers: Effect of bicarbonate-buffered peritoneal dialysis fluids on peritoneal cell function  

Microsoft Academic Search

Biocompatibility and buffers: Effect of bicarbonate-buffered peritoneal dialysis fluids on peritoneal cell function.BackgroundConventional peritoneal dialysis fluids (PDF) have been shown to compromise the function of both leukocytes and human peritoneal mesothelial cells (HPMC). Various in vitro studies have identified the low initial pH in combination with high lactate content, as well as the hyperosmolality and high glucose concentration present in

Achim Jörres; Thorsten O Bender; André Finn; Janusz Witowski; Sibylle Fröhlich; Gerhard M Gahl; Ulrich Frei; Heiko Keck; Jutta Passlick-Deetjen

1998-01-01

6

Effects of ammonium bicarbonate on the electrospray mass spectra of proteins: evidence for bubble-induced unfolding.  

PubMed

Many protein investigations by electrospray ionization (ESI) mass spectrometry (MS) strive to ensure a "native" solvent environment, i.e., nondenaturing conditions up to the point of gas-phase ion formation. Ideally, these studies would employ a volatile pH buffer to mitigate changes in H(+) concentration that can occur during ESI. Ammonium acetate is a commonly used additive, despite its low buffering capacity at pH 7. Ammonium bicarbonate provides greatly improved pH stabilization, thus offering an interesting alternative. Surprisingly, protein analyses in bicarbonate at pH 7 tend to result in the formation of very high charge states, similar to those obtained when electrospraying unfolded proteins in a denaturing solvent. This effect has been reported previously (Sterling, H. J.; Cassou, C. A.; Susa, A. C.; Williams, E. R. Anal. Chem. 2012, 84, 3795), but its exact mechanistic origin remains unclear. ESI-mediated unfolding does not take place in acetate under otherwise identical conditions. We demonstrate that heating of protein-containing bicarbonate solutions results in extensive foaming, caused by CO2 outgassing. In contrast, acetate solutions do not generate foam. Protein denaturation caused by gas bubbles is a well-known phenomenon. Adsorption to the gas/liquid interface is accompanied by major conformational changes that allow the protein to act as a surfactant. The foaming of beer is a manifestation of this effect. Bubble formation in bicarbonate during ESI is facilitated by collisional and blackbody droplet heating. Our data imply that heat and bubbles act synergistically to cause unfolding during the electrospray process, while proteins reside in ESI droplets. Because of this effect we advise against the use of ammonium bicarbonate for native ESI-MS. Ammonium acetate represents a gentler droplet environment, despite its low buffering capacity. PMID:23724896

Hedges, Jason B; Vahidi, Siavash; Yue, Xuanfeng; Konermann, Lars

2013-06-18

7

Long-Term Ammonium Chloride or Sodium Bicarbonate Treatment in Two Models of Polycystic Kidney Disease  

Microsoft Academic Search

Administration of ammonium chloride aggravates, while short-term administration of sodium or potassium bicarbonate lessens the development of polycystic kidney disease in Han:SPRD rats. We have conducted studies to determine whether the protection afforded by the administration of sodium bicarbonate is sustained and prevents development of uremia during chronic administration and whether the effects of the administration of ammonium chloride and

Vicente E. Torres; Michael G. Branden; Izumi Yoshida; Vincent H. Gattone

2001-01-01

8

Influence of bicarbonate buffer on the methanogenetic pathway during thermophilic anaerobic digestion.  

PubMed

To investigate the influence of bicarbonate on the metabolic pathway of methanogenesis, different concentrations of bicarbonate (0-0.2 mol/L) were applied during thermophilic anaerobic digestion of 2.5 and 5 g/L glucose. The stable carbon isotopic results demonstrated that, as the bicarbonate concentration increased, the proportion of total CH4 generated from hydrogenotrophic methanogenesis generally increased. Furthermore, methane production rates and acetate degradation rates were seriously reduced under high levels of bicarbonate (0.15 and 0.2 mol/L). Meanwhile, carbon isotope fractionation was more prominent in treatments with 5 g/L glucose than that of 2.5 g/L glucose. Increased concentrations of bicarbonate altered the dominant methanogens and bacteria and increased the microbial diversity. The inhibitory effects of high concentrations of bicarbonate suggested that bicarbonate should be used cautiously as a buffer salt in anaerobic processes, especially when methanogenetic pathways were studied. PMID:23587826

Lin, Yucheng; Lü, Fan; Shao, Liming; He, Pinjing

2013-03-21

9

Estimation of the respiration quotient in a bicarbonate buffered batch cell cultivation  

Microsoft Academic Search

In bicarbonate buffered media the carbon dioxide balance is affected by accumulation and therefore the RQ can not directly be calculated from gas flow and gas concentration measurements. To cope with the buffering capacity of such media a Kalman Filter was designed as a software sensor to estimate the RQ. To eliminate the role of a priori knowledge of cell

R. Neeleman; E. J. van den End; A. J. B. van Boxtel

2000-01-01

10

Effect of ammonium carbonate and sodium bicarbonate on anthracnose of papaya  

Microsoft Academic Search

Colletotrichum gloeosporioides is the causal organism of anthracnose inCarica papaya L. (papaya, papaw). The effect of ammonium carbonate (3%) or sodium bicarbonate (2%) in aqueous solution or when incorporated\\u000a into a wax formulation on anthracnose severity in inoculated or naturally infected fruits was examined. Both salts had significant\\u000a effects, but that of ammonium carbonate was greater than that of sodium

D. Sivakumar; N. K. Hewarathgamagae; R. S. Wilson Wijeratnam; R. L. C. Wijesundera

2002-01-01

11

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

12

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

13

Power density enhancement of anion-exchange membrane-installed microbial fuel cell under bicarbonate-buffered cathode condition.  

PubMed

We introduce a high-performance microbial fuel cell (MFC) that was operated using a 0.1 M bicarbonate buffer as the cathodic electrolyte. The MFC had a 136.42 mW/m(2) maximum power density under continuous feeding of 5 mM acetate as fuel. Results of the electrode potential measurements showed that the cathode potential of the bicarbonate-buffered condition was higher than the phosphate-buffered condition, although the phosphate condition had less interfacial resistance between the membrane and electrolyte. Therefore, we posit here that the increased power of the bicarbonate-buffered MFC may be caused by the higher cathode potential rather than by the interfacial membrane-electrolyte resistance. PMID:23314365

Piao, Jingmei; An, Junyeong; Ha, Phuc Thi; Kim, Taeyoung; Jang, Jae Kyung; Moon, Hyunsoo; Chang, In Seop

2013-01-01

14

Ammonium carbonate and/or bicarbonate plus alkaline chlorate oxidant for recovery of uranium values  

SciTech Connect

In accordance with the present invention, uranium values are extracted from materials containing uranium in valence states lower than its hexavalent state by contacting the materials containing uranium with an aqueous alkaline leach solution containing an alkaline chlorate in an amount sufficient to oxidize at least a portion of the uranium in valence states lower than its hexavalent state to its hexavalent state. In a further embodiment of the present invention, the alkaline leach solution is an aqueous solution of a carbonate selected from the group consisting of ammonium carbonate, ammonium bicarbonate and mixtures thereof. In yet another embodiment of the present invention, at least one catalytic compound of a metal selected from the group consisting of copper, cobalt, iron, nickel, chromium and mixtures thereof adapted to assure the presence of the ionic species Cu/sup + +/, Co/sup + +/, Fe/sup + + +/, Ni/sup + +/, Cr/sup + + +/ and mixtures thereof, respectively, during the contacting of the material containing uranium with the alkaline leach solution and in an amount sufficient to catalyze the oxidation of at least a portion of the uranium in its lower valence states to its hexavalent state, is present.

Stapp, P.R.

1983-09-06

15

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

16

Ammonium bicarbonate reduction route to uniform gold nanoparticles and their applications in catalysis and surface-enhanced Raman scattering  

Microsoft Academic Search

A new protocol for the synthesis of nearly monodisperse gold nanoparticles with controllable size is described. The pathway\\u000a is based on the reduction of AuCl4? by ammonium bicarbonate in the presence of sodium stearate under hydrothermal conditions. The particle sizes could be easily\\u000a tuned by regulating the reaction conditions including precursor concentration, reaction temperature and growth time. A tentative\\u000a explanation

Feng Wu; Qing Yang

17

Better Preservation of Peritoneal Morphologic Features and Defense in Rats after Long-Term Exposure to a Bicarbonate\\/ Lactate-Buffered Solution  

Microsoft Academic Search

The long-term effects of a standard lactate-buffered dialysis fluid and a new, two-chamber, bicarbonate\\/lactate- buffered dialysis fluid (with fewer glucose degradation prod- ucts and a neutral pH) were compared in an in vivo peritoneal exposure model. Rats were given daily injections, via an access port, of 10 ml of standard solution or bicarbonate\\/lactate- buffered solution for 9 to 10 wk.

LIESBETH H. P. HEKKING; MOHAMMAD ZAREIE; BAS A. J. DRIESPRONG; DIRK FAICT; ANGELIQUE G. A. WELTEN; INGE DE GREEUW; INGE L. SCHADEE-EESTERMANS; CARIN E. G. HAVENITH; JACOB VAN DEN BORN; PIET M. TER WEE; ROBERT H. J. BEELEN

2001-01-01

18

BIOKID: Randomized controlled trial comparing bicarbonate and lactate buffer in biocompatible peritoneal dialysis solutions in children [ISRCTN81137991  

PubMed Central

Background Peritoneal dialysis (PD) is the preferred dialysis modality in children. Its major drawback is the limited technique survival due to infections and progressive ultrafiltration failure. Conventional PD solutions exert marked acute and chronic toxicity to local tissues. Prolonged exposure is associated with severe histopathological alterations including vasculopathy, neoangiogenesis, submesothelial fibrosis and a gradual loss of the mesothelial cell layer. Recently, more biocompatible PD solutions containing reduced amounts of toxic glucose degradation products (GDPs) and buffered at neutral pH have been introduced into clinical practice. These solutions contain lactate, bicarbonate or a combination of both as buffer substance. Increasing evidence from clinical trials in adults and children suggests that the new PD fluids may allow for better long-term preservation of peritoneal morphology and function. However, the relative importance of the buffer in neutral-pH, low-GDP fluids is still unclear. In vitro, lactate is cytotoxic and vasoactive at the concentrations used in PD fluids. The BIOKID trial is designed to clarify the clinical significance of the buffer choice in biocompatible PD fluids. Methods/design The objective of the study is to test the hypothesis that bicarbonate based PD solutions may allow for a better preservation of peritoneal transport characteristics in children than solutions containing lactate buffer. Secondary objectives are to assess any impact of the buffer system on acid-base status, peritoneal tissue integrity and the incidence and severity of peritonitis. After a run-in period of 2 months during which a targeted cohort of 60 patients is treated with a conventional, lactate buffered, acidic, GDP containing PD fluid, patients will be stratified according to residual renal function and type of phosphate binding medication and randomized to receive either the lactate-containing Balance solution or the bicarbonate-buffered Bicavera® solution for a period of 10 months. Patients will be monitored by monthly physical and laboratory examinations. Peritoneal equilibration tests, 24-h dialysate and urine collections will be performed 4 times. Peritoneal biopsies will be obtained on occasion of intraabdominal surgery. Changes in small solute transport rates, markers of peritoneal tissue turnover in the effluent, acid-base status and peritonitis rates and severity will be analyzed.

Nau, Barbara; Schmitt, Claus P; Almeida, Margarida; Arbeiter, Klaus; Ardissino, Gianluigi; Bonzel, Klaus E; Edefonti, Alberto; Fischbach, Michel; Haluany, Karin; Misselwitz, Joachim; Kemper, Markus J; Ronnholm, Kai; Wygoda, Simone; Schaefer, Franz

2004-01-01

19

Response to Metabolic (Ammonium Chloride) Acidosis at Sea Level and at High Altitude  

Microsoft Academic Search

Summary Ammonium chloride was intravenously infused in a group of sea-leve. residents and in a group of high-altitude natives living at 4300 m above sea level. Blood pH, and buffer base; plasma bicarbonate, chloride, sodium and potassium; and urine pH, ammonium and titratable acidity were determined before and after the ammonium infusion. Blood pH, pCO2 blood buffer base, serum bicarbonate

R. Lozano; C. Torres; C. Marchena; J. Whittembury; C. C. Monge

1969-01-01

20

Electrochemical and spectroscopic studies of uranium(IV), -(V), and -(VI) in carbonate-bicarbonate buffers  

Microsoft Academic Search

Recently a need for more detailed knowledge of the chemistry of actinide ions in basic media has arisen in connection with deducing their chemistry in the environment. In this work the results of polarographic, cyclic voltammetric, and spectroscopic studies of U(IV), -(V), and -(VI) in carbonate and bicarbonate media are reported. Polarographic studies were in excellent agreement with those reported

D. W. Wester; J. C. Sullivan

1980-01-01

21

An in vivo microperfusion study of distal tubule bicarbonate reabsorption in normal and ammonium chloride rats.  

PubMed

For many years it has been thought that distal nephron hydrogen ion secretion can be importantly modulated by factors such as sodium delivery, sodium avidity, and potassium stores. Free flow micropuncture studies have also indicated that the rate of bicarbonate delivery may also alter the rate of bicarbonate reabsorption. The present studies were undertaken to examine possible luminal influences on total CO2 reabsorption in microperfused distal tubules in the rat in vivo. Tubules from normal and acidotic rats were perfused with five solutions in a manner that induced changes in bicarbonate load, sodium and potassium fluxes (JNa, JK), and luminal sulfate concentration. in each collected perfusate, simultaneous analyses were undertaken to determine water reabsorption, Na, and K concentrations using graphite furnace atomic absorption spectroscopy and total CO2 by microcalorimetry. Using factorial analysis of covariance to account for confounding effects on total CO2 flux (JtCO2) such as water reabsorption, distal tubules of acidotic rats reabsorbed CO2 in the range of 50-112 pmol X min-1 X mm-1 X These JtCO2 values were not significantly correlated with HCO3 load, JNa, or JK despite changes in the latter from net reabsorption to net secretion. Distal tubules of rats with normal acid-base status had JtCO2 values which were neither significantly different from zero nor correlated with changes in JK and JNa. Further, doubling the load from 250-500 pmol/min (by doubling the perfusion rate of 25-mM HCO3 solutions) did not stimulate JtCO2 in these normal animals. Accordingly, these acute in vivo microperfusion studies indicate for the first time that neither load nor potassium or sodium fluxes are important modulators of distal tubule bicarbonate reabsorption. PMID:2982915

Levine, D Z

1985-02-01

22

Impact of Bicarbonate, Ammonium Chloride, and Acetazolamide on Hepatic and Renal SLC26A4 Expression  

Microsoft Academic Search

SLC26A4 encodes pendrin, a transporter exchanging anions such as chloride, bicarbonate, and iodide. Loss of function mutations of SLC26A4 cause Pendred syndrome characterized by hearing loss and enlarged vestibular aqueducts as well as variable hypothyroidism and goiter. In the kidney, pendrin is expressed in the distal nephron and accomplishes HCO3- secretion and Cl- reabsorption. Renal pendrin expression is regulated by

Ioana Alesutan; Arezoo Daryadel; Nilufar Mohebbi; Lisann Pelzl; Christina Leibrock; Jakob Voelkl; Soline Bourgeois; Silvia Dossena; Charity Nofziger; Markus Paulmichl; Carsten A. Wagner; Florian Lang

2011-01-01

23

Uranium value leaching with ammonium carbonate and/or bicarbonate plus nitrate oxidant and optionally oxidation-catalytic metal compounds  

SciTech Connect

In accordance with the present invention, uranium values are extracted from solid materials containing uranium in lower valence states than its hexavalent state comprising contacting the solid materials containing uranium with an alkaline leach solution containing the ionic species NH/sub 4//sup +/ and NO/sub 3//sup -/ in an amount sufficient to convert at least a portion of the uranium in valence states lower than its hexavalent state to its hexavalent state. In another embodiment of the present invention, the aqueous alkaline leach solution is an aqueous solution of a carbonate selected from the group consisting of ammonium carbonate, ammonium bicarbonate and mixtures thereof. In a further embodiment, ionic species NO/sub 3//sup -/ is supplied by an alkaline nitrate. In yet another embodiment of the present invention, the aqueous alkaline leach solution additionally contains at least one catalytic compound of a metal selected from the group consisting of copper, cobalt, iron, nickel, chromium and mixtures thereof adapted to assure the pesence of the ionic species Cu/sup + +/, Co/sup + +/, Fe/sup + + +/, Ni/sup + +/, Cr/sup + + +/ and mixtures thereof, respectively, is present during the contacting of the solid materials containing uranium with the aqueous alkaline leach solution in an amount sufficient to catalyze the oxidation of at least a part of the uranium in valence states lower than its hexavalent state to its hexavalent state.

Stapp, P.R.

1983-09-20

24

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

2012-12-19

25

Cost of producing UâOâ from ammonium bicarbonate in situ leach solution by the multiple-compartment ion-exchange system  

Microsoft Academic Search

The Bureau of Mines estimated the cost for a uranium ion-exchange recovery system using five grades of UâOâ leach solution producing 815,570 pounds of UâOâ per year from an ammonium bicarbonate in situ leach solution. The system flowsheet consisted of four unit operations: (1) Multiple-compartment ion-exchange (MCIX) absorption; (2) MCIX elution; (3) precipitation of the uranium as yellow cake, filtering,

M. Hayashi; H. Dolezal

1979-01-01

26

A Prospective, Randomized, Double-Blind Study of the Anesthetic Efficacy of Sodium Bicarbonate Buffered 2% Lidocaine With 1 : 100,000 Epinephrine in Inferior Alveolar Nerve Blocks  

PubMed Central

Abstract The authors, using a crossover design, randomly administered, in a double-blind manner, inferior alveolar nerve (IAN) blocks using a buffered 2% lidocaine with 1?:?100,000 epinephrine/sodium bicarbonate formulation and an unbuffered 2% lidocaine with 1?:?100,000 epinephrine formulation at 2 separate appointments spaced at least 1 week apart. An electric pulp tester was used in 4-minute cycles for 60 minutes to test for anesthesia of the first and second molars, premolars, and lateral and central incisors. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes, and the 80 reading was continuously sustained for 60 minutes. For the buffered 2% lidocaine with 1?:?100,000 epinephrine/sodium bicarbonate formulation, successful pulpal anesthesia ranged from 10–71%. For the unbuffered 2% lidocaine with 1?:?100,000 epinephrine formulation, successful pulpal anesthesia ranged from 10–72%. No significant differences between the 2 anesthetic formulations were noted. The buffered lidocaine formulation did not statistically result in faster onset of pulpal anesthesia or less pain during injection than did the unbuffered lidocaine formulation. We concluded that buffering a 2% lidocaine with 1?:?100,000 epinephrine with sodium bicarbonate, as was formulated in the current study, did not statistically increase anesthetic success, provide faster onset, or result in less pain of injection when compared with unbuffered 2% lidocaine with 1?:?100,000 epinephrine for an IAN block.

Whitcomb, Michael; Drum, Melissa; Reader, Al; Nusstein, John; Beck, Mike

2010-01-01

27

Role of bicarbonate\\/CO 2 buffer in the initiation of vesicle-mediated calcification: mechanisms of aortic calcification related to atherosclerosis  

Microsoft Academic Search

Calcifying vesicles play an important role in the mechanism of aortic calcification induced by dietary cholesterol interventions. This study was initiated to test the hypothesis that alterations in the ratio of bicarbonate\\/CO2, which is a main physiological buffer, could affect vesicle-mediated calcification. Using rabbits as a model, in vitro calcification of vesicles isolated from aortas was performed to study the

Howard H. T. Hsu; Benjamin G. Abbo

2004-01-01

28

Effect of two-chambered bicarbonate lactate-buffered peritoneal dialysis fluids on peripheral blood mononuclear cell and polymorphonuclear cell function in vitro  

Microsoft Academic Search

Low pH, high osmolality, increasing glucose concentration, and glucose degradation products (GDP) formed during heat sterilization of conventional peritoneal dialysis (PD) fluids have been shown to have a detrimental effect on cells involved in peritoneal host defense. The two-chambered PD fluid bag in which glucose at pH ? 3 is separated from a bicarbonate (25 mmol\\/L)-lactate (15 mmol\\/L) buffer during

Sumuk Sundaram; Miguel Cendoroglo; Laurinda A. Cooker; Bertrand L. Jaber; Dirk Faict; Clifford J. Holmes; Brian J. G. Pereira

1997-01-01

29

Batch culture growth response of a poultry Salmonella typhimurium isolate to ammonium salts  

Microsoft Academic Search

High ammonium levels have often been associated with poultry waste. In this study we chose to examine the effect of ammonium salt on growth of salmonellae. A nalidixic acid, novobiocin, resistant primary poultry Salmonella typhimurium isolate was grown at 37°C in bicarbonate buffered (60 mm) tryptic-soy broth containing either NH4Cl, NaCl, KCl, (NH4)2SO4, ammonium oxalate, ammonium acetate or NH4OH. Concentrations

S. C. Ricke; D. J. Nisbet; K. G. Maciorowski

1997-01-01

30

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

31

Different performances of soil phosphate tests for reflecting the effects of buffering capacity on uptake of native phosphate with time  

Microsoft Academic Search

The ability of two sodium bicarbonate (Colwell and Olsen) and two ammonium fluoride (Bray I and Bray II) soil tests to reflect the effect of phosphate buffering capacity of the soil on plant growth through time was studied on ten Argentine soils. The soils were divided into three groups (low, medium and high buffering capacity) according to a buffering index

R. E. Mendoza

1989-01-01

32

Proximal tubule specific knockout of the Na?/H? exchanger NHE3: effects on bicarbonate absorption and ammonium excretion.  

PubMed

The existing NHE3 knockout mouse has significant intestinal electrolyte absorption defects, making this model unsuitable for the examination of the role of proximal tubule NHE3 in pathophysiologic states in vivo. To overcome this problem, we generated proximal convoluted tubule-specific KO mice (NHE3-PT KO) by generating and crossing NHE3 floxed mice with the sodium-glucose transporter 2 Cre transgenic mice. The NHE3-PT KO mice have >80 % ablation of NHE3 as determined by immunofluorescence microscopy, western blot, and northern analyses, and show mild metabolic acidosis (serum bicarbonate of 21.2 mEq/l in KO vs. 23.7 mEq/l in WT, p?bicarbonate reabsorption (J HCO3?=?53.52?±?4.61 pmol/min/mm in KO vs. 83.09?±?9.73 in WT) and a ?27 % reduction in volume reabsorption (J v ?=?0.67?±?0.07 nl/min/mm in KO vs. 0.92?±?0.06 nl/min/mm in WT) in mutant mice. The NHE3-PT KO mice tolerated NH4Cl acid load well (added to the drinking water) and showed NH4 excretion rates comparable to WT mice at 2 and 5 days after NH4Cl loading without disproportionate metabolic acidosis after 5 days of acid load. Our results suggest that the Na(+)/H(+) exchanger NHE3 plays an important role in fluid and bicarbonate reabsorption in the proximal convoluted tubule but does not play an important role in NH4 excretion. PMID:23508938

Li, Hong C; Du, Zhaopeng; Barone, Sharon; Rubera, Isabelle; McDonough, Alicia A; Tauc, Michel; Zahedi, Kamyar; Wang, Tong; Soleimani, Manoocher

2013-03-19

33

Comparative anti-ulcerogenic study of pantoprazole formulation with and without sodium bicarbonate buffer on pyloric ligated rat  

PubMed Central

Objective: To compare the anti-ulcer activity of buffered pantoprazole tablet against plain pantoprazole in pyloric ligated rats. Materials and Methods: In vivo pyloric ligated ulcerogenesis model was used to assess the effect of buffered pantoprazole on the volume of the gastric content, pH, total and free acidity, and ulcerogenic lesion. Pantoprazole level in gastric content and concurrently in stomach tissue was assessed by High Performance Liquid Chromatography (HPLC) analysis. Results: Buffered tablet effectively increases the pH of the gastric content above 4 up to 6 h (P<0.001) protecting pantoprazole from acid degradation resulting in high concentration in the gastric content and stomach tissue. Conclusions: This study substantiates better, faster and prolonged bioavailability of pantoprazole-buffered tablet compared to plain pantoprazole.

Bigoniya, Papiya; Shukla, A.; Singh, C. S.; Gotiya, P.

2011-01-01

34

Ammonium bicarbonate as porogen to make tetracycline-loaded porous bioresorbable membranes for dental guided tissue regeneration: failure due to tetracycline instability.  

PubMed

The goal of this work was to manufacture a bioresorbable porous membrane aimed at both promoting osseous regeneration in oral surgery and delivering an antibiotic drug locally. The selected design consisted of a porous poly (D,L-lactic acid) matrix having a closed smooth face on one side to prevent inner migration of conjunctive and epithelial cells, and the rest of the membrane presenting open porosity to allow in-growth of osseous neotissue. The antibiotic drug was tetracycline because of its large antibacterial spectrum and its osteogenetic activity. Solvent casting/particulate leaching and gas foaming/salt leaching methods were selected to create the porosity, and ammonium bicarbonate was selected as thermosensitive water-soluble porogen because other studies reported that sodium chloride was difficult to remove totally. One-side-skinned, porous permeable membranes were successfully obtained. However, deleterious alterations of the drug were observed that were assigned to the basicity of the porogen, thus precluding any practical use in vivo. PMID:17260506

Nublat, Cyril; Braud, Christian; Garreau, Henri; Vert, Michel

2006-01-01

35

Hydroxyl radical generation: the effect of bicarbonate, dioxygen and buffer concentration on pH-dependent chemiluminescence.  

PubMed

Enhanced chemiluminescence (CL) induced by HO* was detected using the primary enhancers luminol (Lum), isoluminol (ILum) and lucigenin (Luc), in the absence of HCO3-, at pH 9.5, 10.0 and 10.5 but not between pH 4.0 and 9.0. This was confirmed using nine different HO* generators. FeCl3/NTA/H2O2 was the only HO* generator that was able to generate singular HO* which was obtained entirely from the Fenton reaction. However, this was so only at pH 10.0 since at all other pHs multiple ROS were produced. This was confirmed by the chemical detection of the fluorescent hydroxylated product of terephthalic acid in the absence of O2. No HO* Lum-CL pH optima coincided with the O2*- mediated Lum-CL optima found at pH 8.0 and 9.0. Bicarbonate had an enhancing effect on Lum-CL which was 70-2700% at pH 10.0 for the different HO* generators. This was due to the conversion of the radical-electron from HO* to CO3*-, making CL detection more efficient since less HO* were lost initially before detection. Methyl-cypridine-luciferin analogue (MCLA) elicited CL in the pH range 4.0-10.0 with the same set of generators in the absence of HCO3-. The iron-containing generators had their different MCLA-CL optima at pH 4.5, 5.0 or 6.0, excluding those overlapping with the O2(*-)-mediated CL optima. The two copper-containing generators had optima at the same pHs, viz, 7.0 and 10.5. Again, FeCl3/NTA/H2O2 was the only HO* generator able to produce singular HO* by the Fenton reaction. However, whereas Lum-CL was able to detect singular HO* only at pH 10.0, MCLA-CL detected it at pH 5.0 and 5.5. Therefore, MCLA is the most suitable CL enhancer for physiological assessments since it is the most sensitive enhancer and has HO* CL optima nearer to physiological pH than the other probes. The HCO3- enhancement of MCLA-CL was even greater than that of Lum-CL, since increases of 114-fold and 37-fold, respectively, were obtained at these HO*-specific pH optima for FeCl3/NTA/H2O2. Therefore, bicarbonate concentration is as important a parameter as pH when the enhanced CL of a non-cellular system is determined. Hydrogen peroxide was not able to elicit CL directly but, due to trace metal contamination, it produced artifactual CL due to HO* formation. High H2O2 levels, which prevent spontaneous O2*- dismutation, helped to establish the overlapping pH optima of CL mediated by O2*- and HO* which were artifactually produced either by O2*- via H2O2 and trace metals or by perferryl intermediates, respectively. Due to spontaneous dismutation to H2O2, only 22% of the O2*- produced by HX/XO could be detected by enhanced CL. PMID:11450981

Oosthuizen, M M; Greyling, D

2001-01-01

36

A semi-empirical mathematical model useful for describing the relationship between carbon dioxide, pH, lactate and base in a bicarbonate-buffered cell-culture process.  

PubMed

The purpose of the present study was to develop a quantitative relationship between the primary factors of state affecting pH control in a bicarbonate-buffered medium. Starting with the Henderson-Hasselbach equation, several assumptions led to the following equation: L = B(T)-s x dCO2 x 10(pH-pK) where L is the lactate concentration (mM), B(T) is the total amount of base added (mM), s is the solubility of CO(2) (mM/%), dCO(2) is the dissolved CO(2) concentration (%) and pK is the acid ionization constant for bicarbonate. This equation appropriately described the relationship of these factors when using bicarbonate, carbonate and HCl (as a lactic acid surrogate) in water. However, the equation required modification to describe the relationship in cell culture medium, due presumably to the presence of other buffers and components; the final form of the equation from an empirical fit in the absence of cells was: L = B(T)-0.88 x dCO2(0.79) x 10(pH-6038) This equation was tested against actual cell culture data, from inoculum preparation in a T-flask through a 10000-litre fed-batch bioreactor, by comparing the lactate concentration calculated from base, pH and dCO(2) data with that actually measured in the bioreactor using a YSI 8500 SELECT Biochemistry Analyzer (YSI Inc., Yellow Springs, OH, U.S.A.). In every case, the calculated and actual lactate concentrations were in good agreement. The equation was useful for isolating the mechanisms leading to varied base addition across 2-, 600- and 10 000-litre-scale bioreactors. This procedure enables a new approach for quantitatively evaluating and understanding factors associated with bioreactor pH control. PMID:17362203

Gramer, Michael J; Ogorzalek, Tad

2007-08-01

37

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2010 CFR

...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 occurs as a white powder or a hard, white or translucent...

2009-04-01

38

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2013 CFR

...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 occurs as a white powder or a hard, white or translucent...

2013-04-01

39

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2010 CFR

...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 occurs as a white powder or a hard, white or translucent...

2010-01-01

40

Use of Trialkyl Ammonium Phosphate (TAAP) Buffers in Reverse Phase HPLC for High Resolution and High Recovery of Peptides and Proteins  

Microsoft Academic Search

A new buffer system compatible with reverse phase high pressure liquid chromatography (RP -HPLC) column packings and giving high recoveries and high resolution for peptides and proteins is described. The TEAP buffer (triethylammonium phosphate), one of several TAAP buffers (trialkylammonium phosphate) compatible with RP-HPLC, gives high resolution and high recovery for closely related peptides or proteins as well as day

Jean E. Rivier

1978-01-01

41

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.

42

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

43

Control of red cell volume and pH in trout: Effects of isoproterenol, transport inhibitors, and extracellular pH in bicarbonate\\/carbon dioxide-buffered media  

Microsoft Academic Search

The effects of extracellular pH and beta-adrenergic stimula- tion on the volume and pH of rainbow trout red cells were studied in HC03-\\/ C02 buffered media. A decrease in extracellular pH caused an increase in red cell volume and a decrease in intracellular pH. The pH-induced changes in cell volume were inhibited by 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic acid, (DIDS), an inhibitor of the

Mikko Nikinmaa; John F. Steffensen; Bruce L. Tufts; David J. Randall

1987-01-01

44

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

45

Sodium bicarbonate and sodium citrate: ergogenic aids?  

PubMed

Numerous studies have used exogenous administration of sodium bicarbonate (NaHCO(3)) and sodium citrate (Na-citrate) in an attempt to enhance human performance. After ingestion of NaHCO(3) and Na-citrate, two observations have been made: (a) There was great individual variability in the ergogenic benefit reached, which can be attributed to the level of physical conditioning of the subjects and to their tolerance of the buffer substance; and (b) the subjects who had ingested NaHCO(3) and Na-citrate show higher levels of pH, bicarbonate, and lactate ions concentrations in their exercising blood than do the subjects who had ingested the placebo. A majority of the studies have suggested that the ingestion of both substances provides an ergogenic effect due to the establishment and maintenance of an elevated pH level during exercise. However, the exact mechanism by which the ergogenic effects occur has not been demonstrated conclusively. Sodium bicarbonate and Na-citrate seem to be effective in activities with a sufficient duration to generate a difference in the hydrogen ion gradient, characterized by a very high intensity and involving large muscular groups. However, in activities of equally high intensity, but with longer duration, the results obtained have been conflicting and inconclusive. PMID:15705037

Requena, Bernardo; Zabala, Mikel; Padial, Paulino; Feriche, Belén

2005-02-01

46

Effects of bicarbonate, citrate, and phosphate loading on performance.  

PubMed

Since the 1930s, scientists have attempted to determine if increasing the body's ability to buffer metabolic acids will enhance physical performance. The buffer of major interest has been bicarbonate; to a lesser degree, citrate and phosphate salts have been investigated. In theory, the buffers facilitate performance by decreasing the accumulation of hydrogen ions that would otherwise presumably inhibit glycolysis and interfere with energy production or impair cross-bridge formation between myofilaments and thereby reduce force production. Literature findings indicate variable results, but overall it appears that bicarbonate salts taken at dosages of 0.3 g.kg-1 may improve performance during repeated sprints or at the end of a progressively more intense exercise test. Athletes are advised of potential ill effects of bicarbonate ingestion, such as gastrointestinal distress. Prior to applying the agents in a competitive setting, athletes should test the effects of buffers on performance during training sessions and consider the sport governing body's stand on buffer usage. PMID:7550253

Horswill, C A

1995-06-01

47

Effects of media buffer systems on growth and electrophysiologic characteristics of cultured sweat duct cells  

Microsoft Academic Search

Summary  Primary cultures of human reabsorptive sweat duct cells were grown in MCDB 170 medium buffered with either HEPES, bicarbonate,\\u000a or a mixture of HEPES and bicarbonate buffers. Cultures grown in MCDB media containing bicarbonate seemed to differentiate\\u000a into a multilayered, keratinized epithelium and began senescing after 1 wk in culture. In contrast, cultures grown in media\\u000a containing HEPES as the

Cindy L. Bell; Paul M. Quinton

1991-01-01

48

Draft Guidance on Omeprazole Sodium Bicarbonate Active ...  

Center for Drug Evaluation (CDER)

Text VersionContains Nonbinding Recommendations Draft Guidance on Omeprazole Sodium Bicarbonate ... Active ingredient: Omeprazole Sodium Bicarbonate ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

49

BAM R70: Sodium Bicarbonate Solution, 10%  

Center for Food Safety and Applied Nutrition (CFSAN)

... BAM R70: Sodium Bicarbonate Solution, 10%. January 2001. Bacteriological Analytical Manual. R70 Sodium Bicarbonate Solution, 10%. ... More results from www.fda.gov/food/foodscienceresearch/laboratorymethods

50

Attractiveness to mexican fruit flies of combinations of acetic acid with ammonium\\/amino attractants with emphasis on effects of hunger  

Microsoft Academic Search

Ammonium acetate was more attractive than other ammonium salts to Mexican fruit flies (Anastrepha ludens) in an orchard test. We hypothesized that acetic acid enhanced the attractiveness of ammonia in the orchard test and that acetic acid may similarly enhance attractiveness of AMPu, an attractant consisting of a mixture of ammonium bicarbonate or ammonium carbonate, methylamine HCl, and putrescine. In

D. C. Robacker; D. S. Moreno; A. B. Demilo

1996-01-01

51

IMPROVED IN VITRO BIOCOMPATIBILITY OF BICARBONATE BUFFERED PERITONEAL DIALYSIS FLUID  

Microsoft Academic Search

? ? ? ? ? Background: Conventional peritoneal dialysis fluids (PDFs) have been shown to damage the mesothelial layer and are associated with the development of peritoneal fi- brosis and neoangiogenesis. New-generation PDFs have therefore been developed with physiological pH and reduced levels of glucose degradation products (GDPs), precursors of advanced glycation end products (AGEs). In this work, we evaluated

Nicolas Grossin; Marie-Paule Wautier; Jean-Luc Wautier; Pierre Gane; Redouane Taamma; Eric Boulanger

52

[Monitoring the stoichiometric relation of ammonium oxidation with the titrimetry of hydrogen ion variation].  

PubMed

A set of automatically titrimetric system to monitor the hydrogen ion variation during biological wastewater treatment process in a batch bioreactor was developed, which consists of a batch bioreactor, data auto-acquisition and preservation unit, and titrant autodosing unit. The accuracy of measurement for the system was evaluated by measuring the stoichiometric ratio of hydrogen ion production amount to ammonium consumption amount of ammonium oxidation in an activated sludge system. The ratios measured in a 1L bioreactor with NH4+ -N concentrations of 1.67, 3.33, 8.33, 16. 66 and 30.00 mg/L as N respectively were very close to the theoretical value, and the relative errors were among 2.09%-6.34%. However, the relative errors in bioreactors of 1, 2, 3 and 4 L with NH4+ -N concentration of 16.66 mg/L as N were among 2.09%- -18.57%, and increased significantly with accretion of the volume of bioreactor. The buffers of bicarbonate and the ammonium, especially the titrimetric dynamic effects in a larger bioreactor are the primarily factors resulting in errors. This study provides an important approach for monitoring hydrogen ion variation in the process of biological wastewater treatment by titrimetry. PMID:20825030

Zhang, Xin; Zhang, Dai-jun; Zhang, Wen-ge; Lu, Pei-li

2010-07-01

53

The rhesus protein RhCG: a new perspective in ammonium transport and distal urinary acidification.  

PubMed

Urinary acidification is a complex process requiring the coordinated action of enzymes and transport proteins and resulting in the removal of acid and the regeneration of bicarbonate. Proton secretion is mediated by luminal H(+)-ATPases and requires the parallel movement of NH?, and its protonation to NH?(+), to provide sufficient buffering. It has been long assumed that ammonia secretion is a passive process occurring by means of simple diffusion driven by the urinary trapping of ammonium. However, new data indicate that mammalian cells possess specific membrane proteins from the family of rhesus proteins involved in ammonia/?m permeability. Rhesus proteins were first identified in yeast and later also in plants, algae, and mammals. In rodents, RhBG and RhCG are expressed in the collecting duct, whereas in humans only RhCG was detected. Their expression increases with maturation of the kidney and accelerates after birth in parallel with other acid-base transport proteins. Deletion of RhBG in mice had no effect on renal ammonium excretion, whereas RhCG deficiency reduces renal ammonium secretion strongly, causes metabolic acidosis in acid-challenged mice, and impairs restoration of normal acid-base status. Microperfusion experiments or functional reconstitution in liposomes demonstrates that ammonia is the most likely substrate of RhCG. Similarly, crystal structures of human RhCG and the homologous bacterial AmtB protein suggest that these proteins may form gas channels. PMID:20927037

Wagner, Carsten A; Devuyst, Olivier; Belge, Hendrica; Bourgeois, Soline; Houillier, Pascal

2010-10-06

54

Effects of lactate-buffered and lactate-free dialysate in CAVHD patients with and without liver dysfunction  

Microsoft Academic Search

Effects of lactate-buffered and lactate-free dialysate in CAVHD patients with and without liver dysfunction.BackgroundContinuous modalities of renal replacement deplete patients of bicarbonate, which is traditionally replaced indirectly by lactate in dialysate or replacement fluids. We have compared a new lactate-free dialysate (unbuffered dialysate with separate bicarbonate replacement of dialytic bicarbonate loss) with standard lactate-buffered dialysate in terms of acid-base control,

Adam G. Mclean; Andrew Davenport; Dominic Cox; Paul Sweny

2000-01-01

55

Buffering the aqueous phase pH in water-in-CO{sub 2} microemulsions  

SciTech Connect

Water-in-oil (w/o) microemulsions have been exploited for use in a wide range of applications, including chemical and enzymatic reactions, protein and metal extraction, and the production of nanoparticles. Microemulsions are attractive systems for studying such applications because they have the ability to function as a universal solvent medium by solubilizing high concentrations of both polar and apolar molecules within their dispersed aqueous and continuous oil phases, respectively. The addition of organic and inorganic buffers to nanometer size water-in-CO{sub 2} microemulsion droplets stabilized by ammonium perfluoropolyether (PFPE-NH{sub 4}) results in an increase in pH from 3 to values of 5--7. The effects of temperature, pressure, buffer type, buffer concentration, ionic strength, and CO{sub 2} solubility on the pH inside water-in-CO{sub 2} microemulsions and on biphasic water-CO{sub 2} systems were measured by the hydrophilic indicator 4-nitrophenyl-2-sulfonate and were predicted accurately with thermodynamic models. In both systems, modest buffer loadings result in a steep pH jump from 2.5 pH units. Further increases in pH require large amounts of base to overcome buffering due to the carbonic acid-bicarbonate equilibrium. A pH approaching neutrality was obtained in w/c microemulsions with approximately 1.5 mol kg{sup {minus}1} NaOH. At high buffer loadings, the effects of temperature and pressure on pH values are negligible.

Holmes, J.D.; Ziegler, K.J.; Audriani, M.; Lee, C.T. Jr.; Bhargava, P.A.; Johnston, K.P. [Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering; Steytler, D.C. [Univ. of East Anglia, Norwich (United Kingdom). School of Chemical Sciences

1999-07-08

56

Comparison of buffers for extraction of mite allergen der p 1 from dust.  

PubMed

Der p 1 is the main allergen of house dust mite Dermatophagoides pteronyssinus, which has routinely been detected in residential dust. However, the procedure for extracting Der p 1 from reservoir dust has not been well defined. The aim of this study was to compare Der p 1 mass fractions in dust extracts prepared using the following extraction buffers: phosphate (pH 7.4), borate (pH 8.0), and ammonium bicarbonate (pH 8.0), all with 0.05 % Tween 20. Twenty-eight dust samples were divided into three aliquots and each portion was extracted with one of the three buffers at room temperature. Der p 1 mass fractions were measured in a total of 84 dust extracts using the enzyme immunoassay (range: 0.1 ?g g-1 to 7.53 ?g g-1). Statistical methods including intraclass correlation showed a high agreement between Der p 1 mass fractions irrespective of the extracting medium. Our results suggest that all three buffers are suitable for the extraction of mite allergens and routine Der p 1 analysis in dust. PMID:23152379

Prester, Ljerka; Kova?i?, Jelena; Macan, Jelena

2012-09-01

57

Effects of Potassium Carbonate and Sodium Bicarbonate on Rumen Function in Lactating Holstein Cows1  

Microsoft Academic Search

Twelve muhiparous lactating Holstein cows were used to compare effects of 1) no buffer, 2) 1.5% sodium bicarbonate, 3) 1.25% potassium carbonate, or 4) 1.85% potassium carbonate in total diet on tureen environment and liquid turn- over, dry matter intake and digestibility, milk yield and composition, and blood acid-base balance. Cows fed buffered diets had greater dry matter intake and

J. W. West; C. E. Coppock; D. H. Nave; J. M. Labore; L. W. Greene; T. W. Odom

1987-01-01

58

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

59

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

60

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

61

The effects of bicarbonate ions and external pH on the membrane potential and resistance of Nitella translucens  

Microsoft Academic Search

Summary The effects of bicarbonate ions on the membrane potential and resistance ofNitella translucens are shown to be primarily due to the change in pH produced by the bicarbonate acting as a buffer, and not due to the presence of an electrogenic anion pump. The mechanism by which pH affects the membrane potential is discussed in the context of recent

R. M. Spanswick

1970-01-01

62

Bicarbonate is an essential constituent of the water-oxidizing complex of photosystem II  

PubMed Central

It is shown that restoration of photoinduced electron flow and O2 evolution with Mn2+ in Mn-depleted photosystem II (PSII) membrane fragments isolated from spinach chloroplasts is considerably increased with bicarbonate in the region pH 5.0–8.0 in bicarbonate-depleted medium. In buffered solutions equilibrated with the atmosphere (nondepleted of bicarbonate), the bicarbonate effect is observed only at pH lower than the pK of H2CO3 dissociation (6.4), which indicates that HCO3? is the essential species for the restoration effect. The addition of just 2 Mn2+ atoms per one PSII reaction center is enough for the maximal reactivation when bicarbonate is present in the medium. Analysis of bicarbonate concentration dependence of the restoration effect reveals two binding sites for bicarbonate with apparent dissociation constant (Kd) of ?2.5 ?M and 20–34 ?M when 2,6-dichloro-p-benzoquinone is used as electron acceptor, while in the presence of silicomolybdate only the latter one remains. Similar bicarbonate concentration dependence of O2 evolution was obtained in untreated Mn-containing PSII membrane fragments. It is suggested that the Kd of 20–34 ?M is associated with the donor side of PSII while the location of the lower Kd binding site is not quite clear. The conclusion is made that bicarbonate is an essential constituent of the water-oxidizing complex of PSII, important for its assembly and maintenance in the functionally active state.

Allakhverdiev, S. I.; Yruela, I.; Picorel, R.; Klimov, V. V.

1997-01-01

63

Buffer Mass Test - Buffer Materials.  

National Technical Information Service (NTIS)

Commercial Na bentonite (MX-80) is the clay component of the buffer material in the heater holes as well of the tunnel backfill. Important characteristics are the clay content, liquid limit, X-ray diffraction pattern, water content, and degree of granulat...

R. Pusch L. Boergesson J. Nilsson

1982-01-01

64

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

2012-11-27

65

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

66

21 CFR 184.1736 - Sodium bicarbonate.  

Code of Federal Regulations, 2010 CFR

...AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3 , CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium...

2010-01-01

67

21 CFR 184.1736 - Sodium bicarbonate.  

Code of Federal Regulations, 2010 CFR

...AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1736 Sodium bicarbonate. (a) Sodium bicarbonate (NaHCO3 , CAS Reg. No. 144-55-8) is prepared by treating a sodium carbonate or a sodium carbonate and sodium...

2009-04-01

68

Bicarbonate Concentration by Synechocystis PCC6803 1  

PubMed Central

The ability of the cyanobacterium Synechocystis PCC6803 to transport inorganic carbon in the form of bicarbonate rapidly decreased following a shift from bicarbonate-limited growth to either excess bicarbonate supply or to photoheterotrophic growth on glucose. Nonmetabolizable analogs of glucose did not exert this effect. The rate at which the bicarbonate uptake rate declined was too rapid to be accounted for by dilution of the activity by culture growth and suggested that posttranslational modification may be involved. Several proteins that were unphosphorylated during bicarbonate-limited growth became phosphorylated during the shifts to high CO2 conditions and to photoheterotrophic growth. A similar alteration in the profile of phosphopolypeptides was observed following a shift into the dark. The changes in protein phosphorylation were not blocked by chloramphenicol or rifampicin. ImagesFigure 2Figure 3

Bloye, Stephen A.; Silman, Nigel J.; Mann, Nicholas H.; Carr, Noel G.

1992-01-01

69

Insensitive Ammonium Nitrate.  

National Technical Information Service (NTIS)

The danger of the accidental detonation of large masses of commercial ammonium nitrate during handling and storage under normal climatic conditions is reduced by replacing the ammonium nitrate with a solid solution of potassium nitrate in form III ammoniu...

C. Boyars

1978-01-01

70

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

71

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

72

Interaction of water activity and bicarbonate salts in the inhibition of growth and mycotoxin production by Fusarium and Aspergillus species of importance to corn  

Microsoft Academic Search

The combined effects of water activity (aw) and ammonium\\/sodium bicarbonate on growth and mycotoxin production in corn by Fusarium and Aspergillus species were investigated. Interaction was observed between the salts and aw on the colony growth rates and lag phase durations of all isolates. Growth stimulation at low salt levels was observed only for the Fusarium isolates as the fastest

S. Samapundo; F. Devlieghere; B. De Meulenaer; Y. Lamboni; D. Osei-Nimoh; J. M. Debevere

2007-01-01

73

DWPF ammonium ion analysis  

SciTech Connect

Ammonium nitrate production during the operation of the Defense Waste Processing Facility (DWPF) has been identified as a major problem. The accumulation of ammonium nitrate deposits in the vent system of the chemical processing cell has substantial safety implications and will require analysis of ammonium ions within DWPF process samples. As a part of the research and development of the DWPF at TNX, an ammonium analysis method developed by Dionex Corporation has been identified and confirmed to provide the required information. This memorandum describes the technical basis of the method, the accuracy and precision of the method, known interferences, and maintenance details.

Eibling, R.E.

1992-06-05

74

Effect of Buffered and Unbuffered Tricaine Methanesulfonate (MS222) at Different Concentrations on the Stress Responses of Channel Catfish, Ictalurus punctatus Rafinesque  

Microsoft Academic Search

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 MS-222 treatments were neutralized with sodium bicarbonate to bring the pH of exposure water to that of rearing water (pH ?7.0). Fish

Thomas L. Welker; Chhorn Lim; Mediha Yildirim-Aksoy; Phillip H. Klesius

2007-01-01

75

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

Code of Federal Regulations, 2012 CFR

...false Applicability; description of the sodium bicarbonate production subcategory...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory ...140 Applicability; description of the sodium bicarbonate production...

2012-07-01

76

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

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the sodium bicarbonate production subcategory...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Sodium Bicarbonate Production Subcategory ...140 Applicability; description of the sodium bicarbonate production...

2010-07-01

77

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

2009-07-01

78

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

79

Sodium bicarbonate supplementation and ingestion timing: does it matter?  

PubMed

Although a considerable amount of literature exists on the ergogenic potential of ingesting sodium bicarbonate (NaHCO3) before short-term, high-intensity exercise, very little exists on optimal loading times before exercise. The purpose of this study was to determine the influence of NaHCO3 supplementation timing on repeated sprint ability (RSA). Eight men completed 3 (randomized and counterbalanced) trials of ten 10-second sprints separated by 50 seconds of active recovery (1:5 work-to-rest) on a nonmotorized treadmill. Before each trial, the subjects ingested 0.3 g·kg(-1) body weight of NaHCO3 at 60 (H1), 120 (H2), or 180 (H3) minutes before exercise. Additionally, the subjects were assessed for any side effects (gastrointestinal [GI] discomfort) from the NaHCO3 ingestion via a visual analog scale (VAS). Blood buffering was assessed using a 2-way analysis of variance (ANOVA) with repeated measures, whereas repeated sprint performance and GI discomfort were assessed via a 1-way ANOVA with repeated measures. Blood-buffering capacity was not different at preexercise times (HCO3(-) [millimoles per liter] H1: 30.2 ± 0.4, H2: 30.9 ± 0.6, H3: 31.2 ± 0.6; p > 0.74). Average speed, average power, and total distance covered progressively declined over the 10 sprints; however, there was no difference between conditions (p > 0.22). The incidence of GI discomfort was significantly higher (p < 0.05) from preingestion at all time points with the exception of 180 minutes, whereas severity was only different between 90 and 180 minutes. Ingestion times (between 60 and 180 minutes) did not influence the blood buffering or the ergogenic potential of NaHCO3 as assessed by RSA. However, VAS scores indicated that at 180 minutes postingestion, an individual is less prone to experiencing significant GI discomfort. PMID:21964428

Siegler, Jason C; Marshall, Paul W M; Bray, James; Towlson, Chris

2012-07-01

80

Ammonium Handling by Superficial and Juxtamedullary Nephrons in the Rat  

PubMed Central

Papillary and surface micropuncture was used to assess the effects of a chronic metabolic acidosis on the renal tubular handling of ammonium by surface nephrons, juxtamedullary nephrons, and the terminal segment of collecting duct. Rats chronically fed ammonium chloride had an expected decline in arterial pH and bicarbonate concentration associated with a doubling in the amount of ammonium excreted and a decline in urine pH. The glomerular filtration rate and absolute delivery of water and sodium to micropuncture sites of surface and deep nephrons was not measurably altered. Ammonium delivery to the end of the proximal tubule increased from 853±102% to 1,197±142% (SE) of the filtered load of ammonium after the induction of metabolic acidosis. This increase was due to a rise in tubular fluid ammonium content from 2.31±0.23 to 4.06±0.28 mM/liter. After the induction of acidosis, absolute and fractional delivery of ammonium ion to the end of the distal tubule was less than to the end of the accessible portion of the proximal tubule. These findings indicate that ammonium is lost in the intervening segment. Ammonium handling by deep nephrons was profoundly affected by acid loading. Absolute delivery to the bend of the loop of Henle increased twofold while fractional delivery rose from 1,222±108% to 1,780±132% of the filtered ammonium. This was due to a marked increase in ammonia entry. During acidosis, ammonium delivery to the terminal segment of the collecting duct was doubled (709±137% in controls vs. 1,415±150% in acidosis, P < 0.005) but did not change between proximal and tip collecting duct sites. In both groups of animals delivery of ammonium to the terminal segment of the collecting duct was greater than to end distal tubular micropuncture sites suggesting that ammonia entry occurred between these two sites. The differences in delivery was greater after the induction of a metabolic acidosis (887±140% vs. 384±144%, P < 0.05). Thus, the present study indicates that deep nephrons contribute to the adaptive increase in ammonium excretion seen during the induction of metabolic acidosis. The data also suggest that ammonia leaves the nephrons at a site(s) along the loop of Henle to enter the collecting duct and that the induction of a metabolic acidosis enhances this reentry.

Buerkert, John; Martin, Daniel; Trigg, David

1982-01-01

81

Electrochemical Concentration and Purification of Spent Sodium Bicarbonate Blasting Media.  

National Technical Information Service (NTIS)

The feasibility and economics of recovering the spent blast media generated in sodium bicarbonate depainting operations has been investigated. In laboratory-scale tests, a saturated sodium bicarbonate solution was convened to sodium hydroxide in an electr...

R. D. Levy R. E. Hicks H. Gold

1995-01-01

82

Sodium Bicarbonate in Chemical Flooding: Part 1: Topical Report.  

National Technical Information Service (NTIS)

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 re...

D. A. Peru P. B. Lorenz

1987-01-01

83

Preparation of ethanol-enriched, bicarbonate-based hemodialysates.  

PubMed

We describe a method to produce bicarbonate-based dialysates containing approximately 100 mg/dl ethanol by introducing the alcohol into one of the dialysate concentrate solutions geared for the production of bicarbonate-based dialysates. PMID:10027893

Noghnogh, A A; Reid, R W; Nawab, Z M; Swartz, R D; Kjellstrand, C M; Ing, T S

1999-02-01

84

Influence of steady-state alterations in acid-base equilibrium on the fate of administered bicarbonate in the dog.  

PubMed Central

Previous workers have shown that metabolic acidosis increases the apparent space through which administered bicarbonate is distributed. This finding has been ascribed to the accompanying acidemia and to the consequent availability of a large quantity of hydrogen ion that accumulates on nonbicarbonate tissue buffers during the development of acidosis. To test this hypothesis, bicarbonate space was measured in dogs with a broad range of steady-state plasma [HCO-3] in association with alkalemia as well as with acidemia. Appropriate combinations of pH and plasma [HCO-3] were achieved by pretreating the animals to produce graded degrees of each of the four cardinal, chronic acid-base disorders. Metabolic acidosis (n = 15) was produced by prolonged HCl-feeding; metabolic alkalosis (n = 17) by diuretics and a chloride-free diet; and respiratory acidosis (n = 9) and alkalosis (n = 8) by means of an environmental chamber. Animals with normal acid-base status (n = 4) were also studied. Sodium bicarbonate (5 mmol/kg) was infused over 10 min to the unanesthetized animals; observations were carried out over 90 min. The results obtained from animals with metabolic acid-base disturbances demonstrated an inverse relationship between bicarbonate space and initial plasma pH, confirming the previous findings of others. By contrast, the results obtained in animals with respiratory acid-base disturbances demonstrated a direct relationship between bicarbonate space and initial plasma pH. The pooled data revealed that bicarbonate space is, in fact, quite independent of the initial pH but is highly correlated with the initial level of extracellular [HCO-3]; dogs with low extracellular [HCO-3] (congruent to 10 meq/liter) whether acidemic or alkalemic, have a bicarbonate space that is 25% larger than normal and some 50% larger than in dogs with high extracellular [HCO-3] (congruent to 50 meq/liter). We conclude from these results that the increased bicarbonate space in metabolic acidosis (and respiratory alkalosis) does not reflect the availability of more hydrogen ions for release during bicarbonate administration, but merely evidences the wider range of titration (delta pH) of nonbicarbonate buffers that occurs during alkali loading whenever plasma [HCO-3] is low.

Adrogue, H J; Brensilver, J; Cohen, J J; Madias, N E

1983-01-01

85

Sizing router buffers  

Microsoft Academic Search

All Internet routers contain buffers to hold packets during times of congestion. Today, the size of the buffers is determined by the dynamics of TCP's congestion control algorithm. In particular, the goal is to make sure that when a link is congested, it is busy 100% of the time; which is equivalent to making sure its buffer never goes empty.

Guido Appenzeller; Isaac Keslassy; Nick McKeown

2004-01-01

86

The Bicarbonate Transporter Is Essential for Bacillus anthracis Lethality  

PubMed Central

In the pathogenic bacterium Bacillus anthracis, virulence requires induced expression of the anthrax toxin and capsule genes. Elevated CO2/bicarbonate levels, an indicator of the host environment, provide a signal ex vivo to increase expression of virulence factors, but the mechanism underlying induction and its relevance in vivo are unknown. We identified a previously uncharacterized ABC transporter (BAS2714-12) similar to bicarbonate transporters in photosynthetic cyanobacteria, which is essential to the bicarbonate induction of virulence gene expression. Deletion of the genes for the transporter abolished induction of toxin gene expression and strongly decreased the rate of bicarbonate uptake ex vivo, demonstrating that the BAS2714-12 locus encodes a bicarbonate ABC transporter. The bicarbonate transporter deletion strain was avirulent in the A/J mouse model of infection. Carbonic anhydrase inhibitors, which prevent the interconversion of CO2 and bicarbonate, significantly affected toxin expression only in the absence of bicarbonate or the bicarbonate transporter, suggesting that carbonic anhydrase activity is not essential to virulence factor induction and that bicarbonate, and not CO2, is the signal essential for virulence induction. The identification of this novel bicarbonate transporter essential to virulence of B. anthracis may be of relevance to other pathogens, such as Streptococcus pyogenes, Escherichia coli, Borrelia burgdorferi, and Vibrio cholera that regulate virulence factor expression in response to CO2/bicarbonate, and suggests it may be a target for antibacterial intervention.

Wilson, Adam C.; Soyer, Magali; Hoch, James A.; Perego, Marta

2008-01-01

87

Correlation of coronary artery calcification with pre-hemodialysis bicarbonate levels in patients on hemodialysis.  

PubMed

Coronary artery calcification (CAC) leads to a significant increase in cardiovascular morbidity and mortality in hemodialysis (HD) patients. Metabolic acidosis, which is common in HD patients, promotes bone resorption in human and animals as a result of buffer function of bone, and calcium and phosphate elute from bone into blood stream. However, the effect of acidosis on CAC in HD patients has never been precisely investigated. This is a cross-sectional observational study performed in a single center. One hundred and seven prevalent HD patients (35 women and 72 men) underwent electron-beam computed tomography (EBCT) to evaluate CAC score (CACS), and then we evaluated associated factors of CACS with clinical and laboratory parameters including pre-HD pH and bicarbonate levels. Pre-HD pH and bicarbonate levels were 7.35 ± 0.04, and 17.6 ± 1.8 mmol/L, respectively. The pre-HD pH had no significant correlation to CACS (r = -0.025, P = 0.81). CACS was significantly negatively correlated with pre-HD bicarbonate levels (r = -0.329, P = 0.0009) and serum albumin levels (r = -0.298, P = 0.0467), while it was positively correlated with age (r = 0.319, P = 0.0008) and HD duration (r = 0.385, P = 0.0004). Serum levels of calcium, phosphorus, intact parathyroid hormone, and use of phosphorus binders were not related to CACS. Multivariate analysis indicated that plasma pre-HD bicarbonate level was independently associated with CACS. The present study showed that blood levels of pre-HD bicarbonate were significantly associated with CAC in HD patients. Further studies are needed to confirm these results and to determine whether correction of metabolic acidosis prevents the development of CAC, one of the features of accelerated atherosclerosis in HD patients. PMID:22607571

Oka, Machiko; Ohtake, Takayasu; Mochida, Yasuhiro; Ishioka, Kunihiro; Maesato, Kyoko; Moriya, Hidekazu; Hidaka, Sumi; Kobayashi, Shuzo

2012-03-05

88

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

PubMed Central

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 studied at baseline and after oral ingestion of 500 mg sodium bicarbonate. The same test was carried out one hour after intravenous injection of 100 mg ranitidine. A glass pH electrode for continuous gastric juice pH measurements and a Tonomitor catheter were placed 10 cm distally from the gastro-oesophageal junction. iPCO2 was measured in saline boluses, infused at 30 minute intervals in the balloon at the tip of the Tonomitor. Before ranitidine was given, basal iPCO2 (mean (SD)) was 8.40 (2.53) kPa, and increased to 19.20 (5.87) kPa after sodium bicarbonate (p < 0.001). After ranitidine, the gastric juice pH increased from 1.8 (0.9) to 5.6 (1.3) (p < 0.05), while basal iPCO2 was 5.60 (0.67) kPa (p < 0.01) and did not change after sodium bicarbonate (6.27 (2.67) kPa)). iPCO2 values after acid secretion suppression were similar to those in capillary blood (5.60 (0.40 kPa)). The difference between intragastric and blood PCO2 during normal acid secretion probably results from buffering of gastric acid by gastric bicarbonate, rather than by duodenogastric reflux or saliva entering the stomach. During acid secretion suppression, intragastric equals blood PCO2, even after oral ingestion of sodium bicarbonate. Hence, acid secretion inhibition is mandatory for proper assessment of iPCO2 and pHi as specific measures of the adequacy of gastric mucosal blood flow.

Kolkman, J J; Groeneveld, A B; Meuwissen, S G

1994-01-01

89

Influence of alkaline buffers on cytoplasmic pH in myocardial cells exposed to hypoxia  

Microsoft Academic Search

The fluorescent intracellular probe 2?,7?-bis-(carboxyethyl)-5,6-carboxyfluorescein acetoxymethyl ester was used in this experimental study to investigate the effects of different alkaline buffers on cytoplasmic pH in suspended myocardial cells under normal as well as hypoxic conditions. A dose-dependent intracellular acidification was achieved after addition of sodium bicarbonate or Tris buffer mixture (Tribonat®) to the myocardial cells under normal conditions. After this

Yu-Cai Li; Lars Wiklund; Gunnel Bjerneroth

1997-01-01

90

Influence of alkaline buffers on cytoplasmic pH in myocardial cells exposed to metabolic acidosis  

Microsoft Academic Search

The influence of different clinically used alkaline buffers on cytoplasmic pH in normal as well as acidotic rat myocardial cells was investigated in this study by means of the fluorescent intracellular probe 2?,7?-bis-(carboxyethyl)-5,6-carboxyfluorescein acetoxymethyl ester (BCECF-AM). It was shown that both sodium bicarbonate and Tris buffer mixture (Tribonat®) caused a significant and dose-dependent acidification of the cytoplasm of suspended myocardial

Yu-Cai Li; Lars Wiklund; Pekka Tarkkila; Gunnel Bjerneroth

1996-01-01

91

Buffering capacity of vertebrate muscle: Correlations with potentials for anaerobic function  

Microsoft Academic Search

Buffering capacities (ß), measured in slykes (µmoles of base required to titrate the pH of one gram wet weight of muscle by one pH unit, over the pH range of pH 6 to pH 7) due to non-bicarbonate buffers were measured in locomotory muscles from a variety of terrestrial and marine mammals and teleost fishes (Tables 1 and 2). The

Michael A. Castellini; George N. Somero

1981-01-01

92

Ammonium nitrate explosive systems  

DOEpatents

Novel explosives which comprise mixtures of ammonium nitrate and an ammonium salt of a nitroazole in desired ratios are disclosed. A preferred nitroazole is 3,5-dinitro-1,2,4-triazole. The explosive and physical properties of these explosives may readily be varied by the addition of other explosives and oxidizers. Certain of these mixtures have been found to act as ideal explosives.

Stinecipher, Mary M. (Los Alamos, NM); Coburn, Michael D. (Los Alamos, NM)

1981-01-01

93

Iron coordination in photosystem II: interaction between bicarbonate and the QB pocket studied by Fourier transform infrared spectroscopy.  

PubMed

The non heme iron environment of photosystem II is studied by light-induced infrared spectroscopy. A conclusion of previous work [Hienerwadel, R., and Berthomieu, C. (1995) Biochemistry 34, 16288-16297] is that bicarbonate is a bidendate ligand of the reduced iron and a monodentate ligand in the Fe(3+) state. In this work, the effects of bicarbonate replacement with lactate, glycolate, and glyoxylate, and of o-phenanthroline binding are investigated to determine the specific interactions of bicarbonate with the protein. Fe(2+)/Fe(3+) FTIR spectra recorded with (12)C- and (13)C(1)-labeled lactate indicate that lactate displaces bicarbonate by direct binding to the iron through one carboxylate oxygen and the hydroxyl group in both the Fe(2+) and Fe(3+) states. This different binding mode with respect to bicarbonate could explain the lower midpoint of the iron couple observed in the presence of this anion [Deligiannakis, Y., Petrouleas, V., and Diner, B. A. (1994) Biochim. Biophys. Acta 1188, 260-270]. In agreement with the -60 mV/pH unit dependence of the iron midpoint potential in the presence of bicarbonate, the proton release upon iron oxidation by photosystem II is directly measured to 0.95 +/- 0.05 by the comparison of infrared signals of phosphate buffer and ferrocyanide modes. This accurate method may be applied to the study of other redox reactions in proteins. The pH dependence of the iron couple is proposed to reflect the deprotonation of D1His215, a putative iron ligand located at the Q(B) pocket, since the signal at 1094 cm(-1) assigned to the nu(C-N) mode of a histidinate ligand in the Fe(3+) state is not observed in the presence of o-phenanthroline. Specific regulation of the pK(a) of D1His215 by bicarbonate is inferred from the absence of the band at 1094 cm(-1) in Fe(2+)/Fe(3+) spectra recorded with glycolate, glyoxylate, or lactate. A broad positive continuum, maximum at approximately 2550 cm(-1), observed in the presence of bicarbonate, but absent with o-phenanthroline or lactate, glycolate, and glyoxylate, indicates a hydrogen bond network from the non heme iron toward the Q(B) pocket involving bicarbonate and His D1-215. Proton release of about 1, measured upon iron oxidation at pH 6 with the latter anions, points to a proton release mechanism different from that involved in the presence of bicarbonate. PMID:11300785

Berthomieu, C; Hienerwadel, R

2001-04-01

94

The anaerobic oxidation of ammonium  

Microsoft Academic Search

From recent research it has become clear that at least two different possibilities for anaerobic ammonium oxidation exist in nature. `Aerobic' ammonium oxidizers like Nitrosomonas eutropha were observed to reduce nitrite or nitrogen dioxide with hydroxylamine or ammonium as electron donor under anoxic conditions. The maximum rate for anaerobic ammonium oxidation was about 2 nmol NH+4 min?1 (mg protein)?1 using

Mike S. M Jetten; Marc Strous; Katinka T van de Pas-Schoonen; Jos Schalk; Udo G. J. M van Dongen; Astrid A van de Graaf; Susanne Logemann; Gerard Muyzer; Mark C. M van Loosdrecht; J. Gijs Kuenen

1998-01-01

95

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 ...

96

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 ...

97

Fluoride Determination in Water: An Optimum Buffer System for Use With the Flouride-Selective Electrode  

Microsoft Academic Search

The departure from linear response which often occurs at dilute fluoride concentrations of the calibration curve reduces the sensitivity of the electrode. The linear portion of the standard curve may be extended to lower fluoride levels by dilution of the buffer itself. TISAB III M. tri-Ammonium citrate (TAC) is the superior of the eleven buffer systems examined in terms of

K. Nicholson; E. J. Duff

1981-01-01

98

Fluoride Determination in Water: An Optimum Buffer System for Use with the Flouride-Selective Electrode  

Microsoft Academic Search

The departure from linear response which often occurs at dilute fluoride concentrations of the calibration curve reduces the sensitivity of the electrode. The linear portion of the standard curve may be extended to lower fluoride levels by dilution of the buffer itself. TISAB III M. tri-Ammonium citrate (TAC) is the superior of the eleven buffer systems examined in terms of

K. Nicholson; E. J. Duff

1981-01-01

99

Depth buffer shadow algorithms  

SciTech Connect

The depth buffer (also called z-buffer) visible surface algorithm is frequently used for shadow simulation. This shadow algorithm is very powerful, but it suffers from several problems such as aliasing and incorrect self-shadowing of simple surfaces. New algorithms are presented which solve these problems for most cases without much additional computation. A family of depth buffer shadow algorithms is defined. Three main improvements are presented. First, replacing the z-buffer with a p-buffer (plane buffer) gives a more accurate representation of the visible surface across a pixel. Second, storing two surface in the shadow buffer the closest and the second surfaces to the light source, and averaging them to form an intermediate surface yields a much better defined illumination test. Third, considering the values of adjacent pixels in the shadow buffer helps to reduce some aliasing artifacts. These techniques preserve all the desirable properties of the depth buffer visible surface algorithm while yielding more accurate shadows. 12 refs., 17 figs.

Grant, C.W.; Allison, M.J.

1990-02-01

100

Organellar Calcium Buffers  

PubMed Central

Ca2+ is an important intracellular messenger affecting many diverse processes. In eukaryotic cells, Ca2+ storage is achieved within specific intracellular organelles, especially the endoplasmic/sarcoplasmic reticulum, in which Ca2+ is buffered by specific proteins known as Ca2+ buffers. Ca2+ buffers are a diverse group of proteins, varying in their affinities and capacities for Ca2+, but they typically also carry out other functions within the cell. The wide range of organelles containing Ca2+ and the evidence supporting cross-talk between these organelles suggest the existence of a dynamic network of organellar Ca2+ signaling, mediated by a variety of organellar Ca2+ buffers.

Prins, Daniel; Michalak, Marek

2011-01-01

101

Hemodialysis-associated cardiac arrhythmias: a lower risk with bicarbonate?  

PubMed

The role of hemodialysis (HD) as an arrhythmogenic event has recently been emphasized. We studied 18 patients by Holter monitoring, comparing the arrhythmogenic effect of acetate dialysis (AHD) and bicarbonate dialysis (BHD). The frequency of ventricular arrhythmias was 93 +/- 66/h in AHD and 32 +/- 26/h in BHD (p less than 0.005). According to the classification of Lown and Graboys, classes III and IV were more often to be found in AHD than in BHD and no patient on BHD was in class IVB and class V. Five patients affected with ischemic heart disease had more frequent and dangerous ventricular arrhythmias than the others; a significant difference between buffers was recorded in all cases but 1. Intradialytic changes in body weight, hematocrit, osmolarity, ionized calcium and potassium during AHD and BHD were similar. The two methods only differed in the quickness and degree of correction of acidosis, and this was related to a significant difference in intraerythrocytic potassium at the end of the session. The quicker and more regular correction of acidosis with BHD and the consequent difference in ionic flows between the intra- and extracellular spaces, as demonstrated by changes in intraerythrocytic potassium at the end of the session, could account for the seemingly less arrhythmogenic effect of BHD. PMID:1865978

Fantuzzi, S; Caico, S; Amatruda, O; Cervini, P; Abu-Turky, H; Baratelli, L; Donati, D; Gastaldi, L

1991-01-01

102

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

1999-05-01

103

Sodium acetate as a replacement for sodium bicarbonate in medical toxicology: a review.  

PubMed

Sodium bicarbonate is central to the treatment of many poisonings. When it was placed on the FDA drug shortage list in 2012, alternative treatment strategies to specific poisonings were considered. Many hospital pharmacies, poison centers, and medical toxicologists proposed sodium acetate as an adequate alternative, despite a paucity of data to support its use in medical toxicology. The intention of this review is to educate the clinician on the use of sodium acetate and to advise them on the potential adverse events when given in excess. We conducted a literature search focused on the pharmacology of sodium acetate, its use as a buffer in pathologic acidemia and dialysis baths, and potential adverse events associated with excess sodium acetate infusion. It appears safe to replace sodium bicarbonate infusion with sodium acetate on an equimolar basis. The metabolism of acetate, however, is more complex than bicarbonate. Future prospective studies will be needed to confirm the efficacy of sodium acetate in the treatment of the poisoned patient. PMID:23636658

Neavyn, Mark J; Boyer, Edward W; Bird, Steven B; Babu, Kavita M

2013-09-01

104

Bicarbonate contributes to GABAA receptor-mediated neuronal excitation in surgically resected human hypothalamic hamartomas.  

PubMed

The role of bicarbonate (HCO(3)(-)) in GABA(A) receptor-mediated depolarization of human hypothalamic hamartoma (HH) neurons was investigated using cellular electrophysiological and calcium imaging techniques. Activation of GABA(A) receptors with muscimol (30 microM) provoked neuronal excitation in over 70% of large (18-22 microM) HH neurons in HCO(3)(-) buffer. Subsequent perfusion of HCO(3)(-)-free HEPES buffer produced partial suppression of muscimol-induced excitation. Additionally, 53% of large HH neurons under HCO(3)(-)-free conditions exhibited reduced intracellular calcium accumulation by muscimol. These results suggest that HCO(3)(-) efflux through GABA(A) receptors on a subpopulation of large HH neurons may contribute to membrane depolarization and subsequent activation of L-type calcium channels. PMID:19022626

Kim, Do-Young; Fenoglio, Kristina A; Kerrigan, John F; Rho, Jong M

2008-11-20

105

Fiber loop optical buffer  

Microsoft Academic Search

Fiber loop optical buffers enable data storage for discrete time intervals and therefore appear suitable for applications in optical asynchronous transfer mode (OATM)-based networks where data are transmitted in cells of fixed length. In this paper, the feasibility and the limitations of optical data storage in a fiber loop optical buffer are studied theoretically and experimentally, A model of a

R. Langenhorst; M. Eiselt; W. Pieper; G. Grosskopf; R. Ludwig; L. Kuller; E. Dietrich; H. G. Weber

1996-01-01

106

Depth buffer shadow algorithms.  

National Technical Information Service (NTIS)

The depth buffer (also called z-buffer) visible surface algorithm is frequently used for shadow simulation. This shadow algorithm is very powerful, but it suffers from several problems such as aliasing and incorrect self-shadowing of simple surfaces. New ...

C. W. Grant M. J. Allison

1990-01-01

107

Effects of Ammonium Sulfate and Ammonium Phosphate on Flammability.  

National Technical Information Service (NTIS)

Ponderosa pine needle and aspen excelsior fuel beds were treated with various amounts of ammonium sulfate and ammonium phosphate and burned in a wind tunnel under controlled environmental conditions. The rate of fire spread, rate of weight loss (equivalen...

C. W. George A. D. Blakely

1972-01-01

108

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

109

Tri-State Buffer  

NSDL National Science Digital Library

This interactive presentation, created by Terry Bartelt and hosted by the Electromechanical Digital Library, discusses the tri-state buffer used in devices employing digital circuitry. A tri-state buffer is "one type of device that is used in digital circuits receiving two logic states but producing three different types of output signals." The presentation is filled with useful flash animations presenting the buffer's use. Furthermore, a series of slides presents the application of this device in different situations. Once complete, a short four-question quiz is provided to test the full understanding of the different concepts.

Bartelt, Terry L.

2009-04-20

110

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

111

Ring Buffered Network Bus.  

National Technical Information Service (NTIS)

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 de...

1997-01-01

112

Coastal Wetlands Buffer Delineation.  

National Technical Information Service (NTIS)

The New Jersey Coastal Management Program requires that development in the coastal zone incorporate a buffer to protect environmentally sensitive areas such as wetlands. The objectives of the present investigation were (a) to measure the levels of direct ...

J. K. Shisler R. A. Jordan R. N. Wargo

1987-01-01

113

A buffer diverter system  

NASA Astrophysics Data System (ADS)

The prevention of sympathetic detonations between donor and acceptor bombs, which are stored lying horizontally lying parallel to each other, is accomplished using a buffer diverter system. One example of a buffer diverter system is a pair of molded concrete bases, each supporting a horizontal bomb and conforming to the shape of its respective bomb up to its horizontal centerline. In the first example, the entire space between the two molded concrete bases and bombs is filled in with a buffer which has sufficient width to attenuate the shock of detonation down pressure levels below a pressure threshold needed to induce an acceptor bomb to sympathetically detonate. In another example of a buffer diverter system, the buffer is replaced with a diverter. The diverter is an I-beam which abuts each bomb at its horizontal centerline and runs the length of the two bombs. The I-beam has the same width as the buffer, but its surface area presented to each bomb is nearly the minimum required to deflect fragments from the silhouette of the acceptor bomb.

Foster, J. C., Jr.

1985-07-01

114

Effects of Potassium Buffers on Feed Intake in Lactating Dairy Cows and on Rumen Fermentation In Vivo and In Vitro1  

Microsoft Academic Search

Twenty-four Holstein cows were used to compare acceptance of concentrates and complete rations containing 1) no buffer, 2) 1.8% potassium bicarbonate, 3) 1.2% potassium carbonate, or 4) 1.5% sodium bicarbonate in the concentrate. When concentrate and a forage blend were offered separately (comparison period 1), concentrate intake did not dif- fer among treatments, but forage blend consumption and complete ration

J. W. West; C. E. Coppock; D. H. Nave; G. T. Schelling

1986-01-01

115

A Proton Buffering Role for Silica in Diatoms  

NASA Astrophysics Data System (ADS)

For 40 million years, diatoms have dominated the reverse weathering of silica on Earth. These photosynthetic protists take up dissolved silicic acid from the water and precipitate opaline silica to form their cell wall. We show that the biosilica of diatoms is an effective pH buffer, enabling the enzymatic conversion of bicarbonate to CO2, an important step in inorganic carbon acquisition by these organisms. Because diatoms are responsible for one-quarter of global primary production and for a large fraction of the carbon exported to the deep sea, the global cycles of Si and C may be linked mechanistically.

Milligan, Allen J.; Morel, François M. M.

2002-09-01

116

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

Code of Federal Regulations, 2010 CFR

... 2010-07-01 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...

2010-07-01

117

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

118

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

Code of Federal Regulations, 2010 CFR

... 2009-07-01 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...

2009-07-01

119

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

120

Heterogeneous reactions of alkylamines with ammonium sulfate and ammonium bisulfate.  

PubMed

The heterogeneous reactions between alkylamines and ammonium salts (ammonium sulfate and ammonium bisulfate) have been studied using a low-pressure fast flow reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS) at 293 ± 2 K. The uptake of three alkylamines, i.e., monomethylamine, dimethylamine, and trimethylamine, on ammonium sulfate shows a displacement reaction of ammonium by aminium, evidenced by the release of ammonia monitored using protonated acetone dimer as the reagent ion. For the three alkylamines, the initial uptake coefficients (?(0)) range from 2.6 × 10(-2) to 3.4 × 10(-2) and the steady-state uptake coefficients (?(ss)) range from 6.0 × 10(-3) to 2.3 × 10(-4) and decrease as the number of methyl groups on the alkylamine increases. A different reaction mechanism is observed for the uptake of the three alkylamines on ammonium bisulfate, which is featured by an acid-base reaction (neutralization) with irreversible alkylamine loss and no ammonia generation and occurs at a rate limited by diffusion of gaseous alkylamines to the ammonium bisulfate surface. Our results reveal that the reactions between alkylamines and ammonium salts contribute to particle growth and alter the composition of ammonium sulfate and bisulfate aerosols in the atmosphere. PMID:21539370

Qiu, Chong; Wang, Lin; Lal, Vinita; Khalizov, Alexei F; Zhang, Renyi

2011-05-03

121

The SVT Hit Buffer  

SciTech Connect

The Hit Buffer is part of the Silicon Vertex Tracker, a trigger processor dedicated to the reconstruction of particle trajectories in the Silicon Vertex Detector and the Central Tracking Chamber of the Collider Detector at Fermilab. The Hit Buffer is a high speed data-traffic node, where thousands of words are received in arbitrary order and simultaneously organized in an internal structured data base, to be later promptly retrieved and delivered in response to specific requests. The Hit Buffer is capable of processing data at a rate of 25 MHz, thanks to the use of special fast devices like Cache-Tag RAMs and high performance Erasable Programmable Logic Devices from the XILINX XC7300 family.

Belforte, S.; Dell`Orso, M.; Donati, S. [I.N.F.N., Pisa (Italy)] [and others

1996-06-01

122

A Multiaccess Frame Buffer Architecture  

Microsoft Academic Search

Many current graphical display systems are based around a memory array commonly known as a frame buffer. In these systems, the frame buffer contains the array of pixels currently being displayed. Updates to the display are accomplished by modifying the values in the frame buffer. The author demonstrates how the performance of frame buffer based systems can be improved by

David T. Harper III

1994-01-01

123

33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...  

Code of Federal Regulations, 2010 CFR

...ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...contamination such as flammable liquids, combustible liquids,...

2010-07-01

124

33 CFR 126.28 - Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...  

Code of Federal Regulations, 2010 CFR

...ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate...ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo...contamination such as flammable liquids, combustible liquids,...

2009-07-01

125

Replacement of forage or concentrate with combinations of soyhulls, sodium bicarbonate, or fat for lactating dairy cows.  

PubMed

A lactation study was performed from wk 4 to 19 of lactation to evaluate the ability of soyhulls with or without 1% sodium bicarbonate to replace corn silage and the ability of soyhulls, roasted soybeans, and rumen-inert fat to replace concentrate. All diets contained similar concentrations of NE(L) (tabular value), CP, and degradable protein. When forage NDF was reduced to 62.5% of total dietary NDF (32 to 36% NDF, depending on analytical method) with soyhulls, milk production and total tract nutrient digestibility were unaffected. Addition of sodium bicarbonate to the soyhull diet reduced milk production, but other production aspects were similar. As evaluated using body condition scoring, cows fed soyhulls with buffer appeared to lose less condition before the trial and to recondition earlier and more during the trial than did those fed soyhulls without buffer, which explains differences in milk production. Buffer did not increase digestibility of OM and NDF, perhaps because the high rate of passage of soyhulls limited digestibility more than did ruminal pH. Replacement of concentrate with soyhulls and fat tended to increase milk and FCM production, resulting in improved efficiency of milk production. However, fat fed to cows reduced the percentage of milk protein. As evaluated during the last 4 wk of a 6-wk posttreatment period, fat fed to cows had no residual effects on any production aspect measured. PMID:1331214

Firkins, J L; Eastridge, M L

1992-10-01

126

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

127

Effect of bicarbonate on neonatal serum ionized magnesium in vitro.  

PubMed

Sodium bicarbonate is used to treat metabolic acidosis, or to induce metabolic alkalosis in sick neonates. The aim of this study was to quantify the decrease in serum concentration of ionized magnesium ([Mg2+]) when sodium bicarbonate is added to neonatal serum in vitro. Sodium bicarbonate was added to 30 cord serum samples of term infants to reach incremental concentrations of 0 to 2.0 mEq/L and [Mg2+] was measured. Serum [Mg2+] decreased significantly with the addition of sodium bicarbonate. At incremental sodium bicarbonate concentrations of 1.0 to 2.0 mEq/L, which is within the range of the desired aim in the treatment of metabolic acidosis, the magnitude of the decrease in serum [Mg2+] was approximately 0.084 to 0.158 mmol/L (18% to 34%) from the average baseline value. The addition of sodium bicarbonate causes a significant decrease in [Mg2+]. From this in vitro study we speculate that fast infusion of sodium bicarbonate in human neonates may potentially cause a clinically significant decrease in serum [Mg2+]. PMID:15319140

Zaidenberg, Galit; Mimouni, Francis B; Dollberg, Shaul

2004-06-01

128

Stimulation of Guanylyl Cyclase-D by Bicarbonate  

PubMed Central

Guanylyl cyclases (GCs) catalyze the conversion of GTP to the second messenger cGMP. While some transmembrane GCs are receptors for extracellular ligands, other transmembrane GCs such as retinal-specific GC-E and GC-F are stimulated by cellular proteins. GC-D is expressed in a special group of olfactory sensory neurons. However, the direct regulatory mechanism of GC-D activity is not completely understood. Here we have demonstrated that bicarbonate directly increases the activity of purified GC-D. Bicarbonate also increases the cGMP levels in cells expressing GC-D. These results identify bicarbonate as a small molecule that regulates GC-D.

Guo, Dagang; Zhang, J. Jillian; Huang, Xin-Yun

2009-01-01

129

Active NaCl transport in the cortical thick ascending limb of Henle's loop of the mouse does not require the presence of bicarbonate  

Microsoft Academic Search

The aim of the present study was to investigate whether bicarbonate buffer (CO2 + HCO3-) is required to sustain maximal NaCl transport in the cortical thick ascending limb of Henle's loop (cTAL) of the mouse. Transepithelial Na+ and Cl- net fluxes (JNa, JCl, pmol min-1 mm-1), measured by electron microprobe analysis, were similar irrespective of the presence or absence of

A. Di Stefano; R. Greger; C. de Rouffignac; M. Wittner

1992-01-01

130

EFFECT OF SODIUM BICARBONATE AND TETRASODIUM PYROPHOSPHATE UPON UTILIZATION OF CONCENTRATE AND ROUGHAGE-BASED CATTLE DIETS: CATTLE STUDIES 1'2  

Microsoft Academic Search

Summary Sodium bicarbonate (NaHCO3) or tetra- sodium pyrophosphate (Na4P:07) was added at either 1.0 or 2.5% of dry matter to either high concentrate (trial I) or high roughage (trial II) based control diets in an attempt to under- stand the reasons for variable feedlot response when dietary buffers are fed in different kinds of diets. Following conclusion of the 70-d

Elvin E. Thomas; Matthew W. Hall

2010-01-01

131

New buffer pH method for rapid estimation of exchangeable acidity and lime requirement of soils  

Microsoft Academic Search

A new buffer pH method (BpH) for the rapid estimation of unbuffered salt?exchangeable acidity (ACe) and lime requirement (LR) has been developed. The buffer reagent, consisting of sodium glycerophosphate, acetic acid, trletlianolamine, ammonium chloride and barium chloride, was useful within the pH range 3.8 to 6.6. Delta values from BpH were converted into buffer pH acidity values (AC) and calibrated

A. Mehlich

1976-01-01

132

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

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation...176.410 Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. (a) This...

2009-10-01

133

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation...176.410 Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. (a) This...

2010-10-01

134

Ammonium diphosphitoindate(III)  

PubMed Central

The crystal structure of the title compound, NH4[In(HPO3)2], is built up from InIII cations (site symmetry 3m.) adopting an octa­hedral environment and two different phosphite anions (each with site symmetry 3m.) exhibiting a triangular–pyramidal geometry. Each InO6 octa­hedron shares its six apices with hydrogen phosphite groups. Reciprocally, each HPO3 group shares all its O atoms with three different metal cations, leading to [In(HPO3)2]? layers which propagate in the ab plane. The ammonium cation likewise has site symmetry 3m.. In the structure, the cations are located between the [In(HPO3)2]? layers of the host framework. The sheets are held together by hydrogen bonds formed between the NH4 + cations and the O atoms of the framework.

Hamchaoui, Farida; Rebbah, Houria; Le Fur, Eric

2013-01-01

135

Bicarbonate dosing: a tool to performance recovery of a thermophilic methanol-fed UASB reactor.  

PubMed

The thermophilic-anaerobic treatment of methanol-containing wastewater in an upflow anaerobic sludge blanket (UASB) reactor, was found to be quite sensitive to pH shocks, both acid and alkaline. The results of the recovery experiments of sludge exposed to an alkaline shock, indicated that the addition or deprivation of sodium bicarbonate (NaHCO3) in the medium, plays an important role in the competition of methanogens and (homo)acetogens for methanol. In addition, caution has to be taken when using NaHCO3 for buffering methanol-containing wastewaters, since its introduction in the system will favour (homo)acetogenesis when proper conditions are not established. Based on these results, a recovery strategy for methanogenesis was proposed where bicarbonate is supplied stepwise, and the reactor is operated in a batch mode. This strategy was found to be appropriate, i.e. the results revealed that the recovery of methanogenesis on methanol from a reactor upset or complete failure caused by pH shock is possible, even in systems where (homo)acetogens are outcompeting methanogens. The time and the number of feedings required will depend on the degree of deterioration of the sludge. PMID:14640205

Paulo, P L; van Lier, J B; Lettinga, G

2003-01-01

136

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 ...

137

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...

138

Ammonium Regulation in Aspergillus nidulans  

PubMed Central

l-Glutamate uptake, thiourea uptake, and methylammonium uptake and the intracellular ammonium concentration were measured in wild-type and mutant cells of Aspergillus nidulans held in various concentrations of ammonium and urea. The levels of l-glutamate uptake, thiourea uptake, nitrate reductase, and hypoxanthine dehydrogenase activity are determined by the extracellular ammonium concentration. The level of methylammonium uptake is determined by the intracellular ammonium concentration. The uptake and enzyme characteristics of the ammonium-derepressed mutants, meaA8, meaB6, DER3, amrA1, xprD1, and gdhA1, are described. The gdhA mutants lack normal nicotinamide adenine dinucleotide phosphate-glutamate dehydrogenase (NADP-GDH) activity and are derepressed with respect to both external and internal ammonium. The other mutant classes are derepressed only with respect to external ammonium. The mutants meaA8, DER3, amrA1, and xprD1 have low levels of one or more of the l-glutamate, thiourea, and methylammonium uptake systems. A model for ammonium regulation in A. nidulans is put forward which suggests: (i) NADP-GDH located in the cell membrane complexes with extracellular ammonium. This first regulatory complex determines the level of l-glutamate uptake, thiourea uptake, nitrate reductase, and xanthine dehydrogenase by repression or inhibition, or both. (ii) NADP-GDH also complexes with intracellular ammonium. This second and different form of regulatory complex determines the level of methylammonium uptake by repression or inhibition, or both.

Pateman, J. A.; Kinghorn, J. R.; Dunn, Etta; Forbes, E.

1973-01-01

139

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

140

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

141

Simultaneous routing and buffer insertion with restrictions on buffer locations  

Microsoft Academic Search

During the routing of global interconnects, macro blocks formuseful routing regions which allow wires to go through but forbidbuffers to be inserted. They give restrictions on bufferlocations. In this paper, we take these buffer location restrictionsinto consideration and solve the simultaneous mazerouting and buffer insertion problem. Given a block placementdefining buffer location restrictions and a pair of pins(a source and

Hai Zhou; D. F. Wong; I-Min Liu; Adnan Aziz

1999-01-01

142

Principles of database buffer management  

Microsoft Academic Search

This paper discusses the implementation of a database buffer manager as a component of a DBMS. The interface between calling components of higher system layers and the buffer manager is described; the principal differences between virtual memory paging and database buffer management are outlined; the notion of referencing versus addressing of database pages is introduced; and the concept of fixing

Wolfgang Effelsberg; Theo Haerder

1984-01-01

143

EnFET for urea determination in biological fluids using ammonium ion detection  

NASA Astrophysics Data System (ADS)

In this paper a method of urease immobilization on the surface of the Siloprene membrane of the ammonium ion sensitive ChemFET is presented. The usability of the sensor for determination of urea in solutions at pH typical for biological fluids (pH 6 to pH 7.5) has been investigated. Due to the fact that the sensor exhibits high sensitivity to samples of low buffer capacity, the method of preliminary sample treatment, consisting in addition of buffers at adequate buffer capacity was developed. The sensors were tested in dialysate and blood plasma.

Dawgul, Marek; Trybun, Tomasz; Pijanowska, Dorota G.; Torbicz, Wladyslaw

2003-09-01

144

Buffer Energy Nuclear Fusion  

NASA Astrophysics Data System (ADS)

A compact scheme of non-thermonuclear fusion is presented. Hydrogen ions are implanted directly from nonthermal discharge plasma or ion source into a surface of liquid Li metal at a buffer energy of a few tens keV where nuclear stopping occurs. The ions interact with Li atoms or mixed element atoms which are not being internally excited and tend towards the formation of united atoms at the minimum Gibbs free energy point. This leads to the enhanced rate of non-thermonuclear fusion of hydrogen ions due to cohesion in the liquid metal.

Ikegami, Hidetsugu

2001-10-01

145

Experimental studies on the chemiluminescence reaction mechanism of carbonate/bicarbonate and hydrogen peroxide in the presence of cobalt(II).  

PubMed

Chemiluminescence (CL) phenomena of carbonates or bicarbonates of potassium, sodium, or ammonium with hydrogen peroxide in the presence of cobalt sulfate were reported. After cobalt(II) solution was injected into the mixture of carbonate/bicarbonate and hydrogen peroxide, a CL signal was given out briefly. The CL conditions of these systems were optimized. The CL reaction mechanisms were studied experimentally by examining the spectrum emitted by the CL system and the effect of various free radical scavengers on CL emission intensity. The results showed that the maximal emission wavelengths of the CO32--H2O2-Co2+ and HCO3--H2O2-Co2+ systems were 440 and 490 nm, respectively. As a result, a radical scavenger of ascorbic acid, thiourea, and superoxide dismutase exhibited different effects on these CL systems. The different CL mechanisms involving the carbon dioxide dimer and the oxygen dimer were revealed, respectively. PMID:18173250

Liang, Shu-Xuan; Zhao, Li-Xia; Zhang, Bo-Tao; Lin, Jin-Ming

2008-01-04

146

The anaerobic oxidation of ammonium.  

PubMed

From recent research it has become clear that at least two different possibilities for anaerobic ammonium oxidation exist in nature. 'Aerobic' ammonium oxidizers like Nitrosomonas eutropha were observed to reduce nitrite or nitrogen dioxide with hydroxylamine or ammonium as electron donor under anoxic conditions. The maximum rate for anaerobic ammonium oxidation was about 2 nmol NH4+ min-1 (mg protein)-1 using nitrogen dioxide as electron acceptor. This reaction, which may involve NO as an intermediate, is thought to generate energy sufficient for survival under anoxic conditions, but not for growth. A novel obligately anaerobic ammonium oxidation (Anammox) process was recently discovered in a denitrifying pilot plant reactor. From this system, a highly enriched microbial community with one dominating peculiar autotrophic organism was obtained. With nitrite as electron acceptor a maximum specific oxidation rate of 55 nmol NH4+ min-1 (mg protein)-1 was determined. Although this reaction is 25-fold faster than in Nitrosomonas, it allowed growth at a rate of only 0.003 h-1 (doubling time 11 days). 15N labeling studies showed that hydroxylamine and hydrazine were important intermediates in this new process. A novel type of hydroxylamine oxidoreductase containing an unusual P468 cytochrome has been purified from the Anammox culture. Microsensor studies have shown that at the oxic/anoxic interface of many ecosystems nitrite and ammonia occur in the absence of oxygen. In addition, the number of reports on unaccounted high nitrogen losses in wastewater treatment is gradually increasing, indicating that anaerobic ammonium oxidation may be more widespread than previously assumed. The recently developed nitrification systems in which oxidation of nitrite to nitrate is prevented form an ideal partner for the Anammox process. The combination of these partial nitrification and Anammox processes remains a challenge for future application in the removal of ammonium from wastewater with high ammonium concentrations. PMID:9990725

Jetten, M S; Strous, M; van de Pas-Schoonen, K T; Schalk, J; van Dongen, U G; van de Graaf, A A; Logemann, S; Muyzer, G; van Loosdrecht, M C; Kuenen, J G

1998-12-01

147

AN AMINO ACID-BASED PERITONEAL DIALYSIS FLUID BUFFERED WITH BICARBONATE VERSUS GLUCOSE\\/BICARBONATE AND GLUCOSE\\/LACTATE SOLUTIONS: AN INTRAINDIVIDUAL RANDOMIZED STUDY  

Microsoft Academic Search

? ? ? ? ? Patients: Ten nondiabetic patients stable on continu- ous ambulatory peritoneal dialysis (time on dialysis, 42.5 ± 21.5 months) were treated and monitored with the test solutions over a 6-hour dwell. Three different study days followed in a randomized order for each patient (interval of 1 - 3 weeks). Blood and dialysate samples were taken at

Jörg Plum; Christine Erren; Claus Fieseler; Judith Kirchgessner; Jutta Passlick-Deetjen

148

Provably good global buffering using an available buffer block plan  

Microsoft Academic Search

To implement high-performance global interconnect without impacting the performance of existing blocks, the use of buffer blocks is increasingly popular in structured-custom and block-based ASIC\\/SOC methodologies. Recent works by Cong et al. [6] and Tang and Wong [25] give algorithms to solve the buffer block planning problem. In this paper we address the problem of how to perform buffering of

Feodor F. Dragan; Andrew B. Kahng; Ion I. Mandoiu; Sudhakar Muddu; Alexander Zelikovsky

2000-01-01

149

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

2009-05-18

150

Effects of Ammonium Metavanadate Treatment Upon Macrophage Glutathione Redox Cycle Activity, Superoxide Production, and Intracellular Glutathione Status  

Microsoft Academic Search

Female B6C3F1 mice were given intraperitoneal injections of ammonium metavanadate (2.5 or 10 mg V\\/Kg), ammonium chloride, or sodium phosphate buffer every 3 days for 6 weeks. Resident peritoneal macrophages were harvested, lysed by freeze-thawing, and the resulting cytolysate was assayed for total protein content and enzyme activities of glutathione reductase, giutathlone peroxidase, and glucose-6-phosphate dehydroge- nase. In addition, peritoneal

M. D. Cohen; C. I. Wei

151

Buffer capacity of biologics--from buffer salts to buffering by antibodies.  

PubMed

Controlling pH is essential for a variety of biopharmaceutical process steps. The chemical stability of biologics such as monoclonal antibodies is pH-dependent and slightly acidic conditions are favorable for stability in a number of cases. Since control of pH is widely provided by added buffer salts, the current study summarizes the buffer characteristics of acetate, citrate, histidine, succinate, and phosphate buffers. Experimentally derived values largely coincide with values calculated from a model that had been proposed in 1922 by van Slyke. As high concentrated protein formulations become more and more prevalent for biologics, the self-buffering potential of proteins becomes of relevance. The current study provides information on buffer characteristics for pH ranges down to 4.0 and up to 8.0 and shows that a monoclonal antibody at 50 mg/mL exhibits similar buffer capacity as 6 mM citrate or 14 mM histidine (pH 5.0-6.0). Buffer capacity of antibody solutions scales linearly with protein concentration up to more than 200 mg/mL. At a protein concentration of 220 mg/mL, the buffer capacity resembles the buffer capacity of 30 mM citrate or 50 mM histidine (pH 5.0-6.0). The buffer capacity of monoclonal antibodies is practically identical at the process relevant temperatures 5, 25, and 40°C. Changes in ionic strength of ?I=0.15, in contrast, can alter the buffer capacity up to 35%. In conclusion, due to efficient self-buffering by antibodies in the pH range of favored chemical stability, conventional buffer excipients could be dispensable for pH stabilization of high concentrated protein solutions. PMID:23296746

Karow, Anne R; Bahrenburg, Sven; Garidel, Patrick

2013-03-01

152

Anaerobic ammonium oxidation for treatment of ammonium-rich wastewaters.  

PubMed

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

2008-05-01

153

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

154

TREATMENT OF AMMONIUM NITRATE SOLUTIONS  

DOEpatents

The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.

Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.

1958-06-10

155

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

Code of Federal Regulations, 2013 CFR

...Exemptions From Tolerances § 180.1177 Potassium bicarbonate; exemption from the requirement of a tolerance. The biochemical pesticide potassium bicarbonate is exempted from the requirement of a tolerance in or on all raw agricultural...

2013-07-01

156

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

Code of Federal Regulations, 2013 CFR

... Exemptions From Tolerances § 180.1176 Sodium bicarbonate; exemption from the requirement of a tolerance. The biochemical pesticide sodium bicarbonate is exempted from the requirement of a tolerance in or on all raw agricultural...

2013-07-01

157

Ammonium metabolism and protection from urease mediated destruction in Helicobacter pylori infection.  

PubMed Central

AIM: To investigate further the intracellular ammonium metabolism of Helicobacter pylori and the mechanism of its urease mediated destruction. METHODS: The mechanism of the in vitro destruction of H pylori was investigated by incubating it in buffer solutions, at pH 6.0, containing isocitrate or alpha ketoglutarate in addition to urea concentrations which had previously been shown to destroy H pylori. RESULTS: The median (range) 5 minute survival of H pylori in 0.2 mol/l citrate buffer (pH 6.0) in the absence of urea was 88% (18-184%) and was similar to its survival in 0.2 mol/l isocitrate buffer in the absence of urea, median 88% (15-274%). In the presence of 50 mmol/l urea the survival of H pylori in the citrate buffer was reduced, 9.9% (0-146%), compared with its survival in isocitrate buffer with the same concentration of urea 37% (0-274%) (p < 0.01). A 72 hour preincubation of the organism with 10 mmol/l alpha ketoglutarate also increased the 5 minute survival of the organism in 0.2 mol/l citrate buffer containing 50 mmol/l urea to 36% (9-145%) compared with its survival in the same buffer but without preincubation with alpha ketoglutarate 0% (0-62%). CONCLUSION: The protection of H pylori from rapid destruction by the supply of compounds used in the intracellular metabolism of the ammonium shows that the urease mediated destruction of H pylori can be explained by intracellular depletion of alpha ketoglutarate as a result of over production of ammonium by uncontrolled urease activity.

Neithercut, W D; Williams, C; Hossack, M S; McColl, K E

1993-01-01

158

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

159

Buffering in optical packet switches  

Microsoft Academic Search

This paper consists of a categorization of optical buffering strategies for optical packet switches, and a comparison of the performance of these strategies both with respect to packet loss\\/delay and bit error rate (BER) performance. Issues surrounding optical buffer implementation are discussed, and representative architectures are introduced under different categories. Conclusions are drawn about packet loss and BER performance, and

David K. Hunter; Meow C. Chia; Ivan Andonovic

1998-01-01

160

THE INFLUENCE OF HENRY'S LAW ON BICARBONATE EQUILIBRIA  

Microsoft Academic Search

In a closed system, water saturated with sodium bicarbonate maintains a constant pH. But when the water contacts CO? in air, pH rises. It is possible to determine the ultimate pH of a water when it comes to equilibrium of the CO? in the atmosphere.

Jerome F. Thomas; R. Rhodes Trussell

1970-01-01

161

Relationship Between Bicarbonate Retention and Bone Characteristics in Broiler Chickens  

Microsoft Academic Search

Determination of the bicarbonate retention factor (BRF) is an important step during development of the indicator amino acid oxidation technique for use in a new model. A series of 4-h oxidation experiments were performed to determine the BRF of broilers aged 7, 14, 21, 28, 35, and 42 d using 4 birds per age group. A priming dose of 1.2

M. A. Leslie; R. A. Coleman; S. Moehn; R. O. Ball; D. R. Korver

162

EFFECTS OF SODIUM BICARBONATE ON REDUCING ACIDOSIS IN CATTLE  

Microsoft Academic Search

ABSTRACT A study was conducted to determine whether feeding sodium,bicarbonate (SB) reduces the risk of subacute acidosis (SARA) in cattle receiving high concentrate diets. Twelve Hereford cross heifers (Exp.1) and six ruminally cannulated animals (Exp. 2; three Jersey steers and three Holstein cows), previously adapted to a high concentrate diet, were used in 3 _ 3 Latin square designs to

LAURA JANE PATON

2005-01-01

163

Peripheral melatonin mediates neural stimulation of duodenal mucosal bicarbonate secretion  

PubMed Central

Melatonin is released from intestinal enterochromaffin cells and from the pineal gland, but its role in gastrointestinal function is largely unknown. Our aim was to study the involvement of intestinal and central nervous melatonin in the neurohumoral control of the duodenal mucosa-protective bicarbonate secretion. Working in anesthetized rats, we cannulated a 12-mm segment of duodenum with an intact blood supply and titrated the local bicarbonate secretion with pH-stat. Melatonin and receptor ligands were supplied to the duodenum by close intra-arterial infusion. Even at low doses, melatonin and the full agonist 2-iodo-N-butanoyl-5-methoxytryptamine increased duodenal bicarbonate secretion. Responses were inhibited by the predominantly MT2-selective antagonist luzindole but not by prazosin, acting at MT3 receptors. Also, luzindole almost abolished the marked rise in secretion induced by intracerebroventricular infusion of the adrenoceptor agonist phenylephrine. This response was also abolished by sublaryngeal ligation of all nerves around the carotid arteries. However, it was insensitive to truncal vagotomy alone or sympathectomy alone and was unaffected by removal of either the pineal gland or pituitary gland. Thus, melatonin stimulates duodenal bicarbonate secretion via action at enterocyte MT2-receptors and mediates neural stimulation of the secretion.

Sjoblom, Markus; Jedstedt, Gunilla; Flemstrom, Gunnar

2001-01-01

164

Improving Eggshell Quality at High Temperatures with Dietary Sodium Bicarbonate  

Microsoft Academic Search

Two experiments were conducted that confirmed the hypothesis that a dietary bicarbonate supplement will improve eggshell quality in hens at high temperatures as long as feed is consumed during the period of eggshell formation. End-of-lay hens were maintained on continuous light at temperatures of 30 and 35 C. Individual egg weights and shell quality measures for each hen were calculated

D. BALNAVE; S. K. MUHEEREZA

165

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

166

Effect of sampling depth on bicarbonate soil phosphorus test values  

Microsoft Academic Search

In three field experiments involving five levels of application of phosphorus (P) on three different lateritic ironstone gravel soils in south-western Australia, soil samples were collected from dry soil, one year after P application in one experiment or two years after in the other two experiments, to measure the amount of P extracted by sodium bicarbonate (soil test P). The

M. D. A. Bolland

1992-01-01

167

Removal of co-present chromate and arsenate by zero-valent iron in groundwater with humic acid and bicarbonate.  

PubMed

The interactions of co-present Cr(VI) and As(V), and the influences of humic acid and bicarbonate in the process of Cr(VI) and As(V) removal by Fe(0) were investigated in a batch setting using simulated groundwater with 5 mM NaCl, 1 mM Na(2)SO(4), and 0.8 mM CaCl(2) as background electrolytes at an initial pH value of 7. Cr(VI) and As(V) were observed to be subject to different impacts induced by co-existing As(V) or Cr(VI), humic acid and bicarbonate, originating from their distinct removal mechanisms by Fe(0). Cr(VI) removal is a reduction-dominated process, whereas As(V) removal principally involves adsorption onto iron corrosion products. Experimental results showed that Cr(VI) removal was not affected by the presence of As(V) and humic acid. However, As(V) removal appeared to be inhibited by co-present Cr(VI). When the Cr(VI) concentration was 2, 5, and 10 mg/L, in the absence of humic acid and bicarbonate, As(V) removal rate constants were decreased by 27.9%, 49.0%, and 61.2%, respectively, which probably resulted from competition between Cr(VI) and As(V) for adsorption sites of the iron corrosion products. Furthermore, the presence of humic acid significantly varied As(V) removal kinetics by delaying the formation and aggregation of iron hydroxides due to the formation of soluble Fe-humate complexes and stably dispersed fine iron hydroxides colloids. In the presence of bicarbonate, both Cr(VI) and As(V) removal was increased and the inhibitory effect of Cr(VI) on As(V) removal was suppressed, resulting from the buffering effects and the promoted iron corrosion induced by bicarbonate, and the formation of CaCO(3) in solution, which enhanced As(V) adsorption. PMID:19321187

Liu, Tongzhou; Rao, Pinhua; Mak, Mark S H; Wang, Peng; Lo, Irene M C

2009-03-12

168

Influence of ammonium nitrate on kinetics and mechanism of thermal decomposition of ammonium polyuranates  

SciTech Connect

The influence of ammonium nitrate on the mechanism and kinetics of dehydration and thermal decomposition of ammonium polyuranates was studied. An appreciable influence of the nitrate ion content in the samples of ammonium polyuranates on the development of thermal stability has been noted. The kinetic parameters of the thermal decomposition of ammonium polyuranates have been evaluated. A mechanism of the dehydration and thermal decomposition of ammonium polyuranates in the presence of ammonium nitrate has been proposed. It was shown that increase in the content of ammonium nitrate in the precipitate of ammonium polyuranates leads to a decrease in the specific surface of uranoso-uranic oxide.

Karelin, A.I.; Lobas, O.P.; Zhiganov, A.N.; Vasil'ev, K.F.; Zhiganova, A.A.

1988-05-01

169

Bench-to-bedside review: Treating acid–base abnormalities in the intensive care unit – the role of buffers  

Microsoft Academic Search

The recognition and management of acid–base disorders is a commonplace activity for intensivists. Despite the frequency with which non-bicarbonate-losing forms of metabolic acidosis such as lactic acidosis occurs in critically ill patients, treatment is controversial. This article describes the properties of several buffering agents and reviews the evidence for their clinical efficacy. The evidence supporting and refuting attempts to correct

Brian K Gehlbach; Gregory A Schmidt

2004-01-01

170

Effect of sodium bicarbonate in rats acutely poisoned with dichlorvos.  

PubMed

The development of effective antidotes against organophosphates such as dichlorvos has been a persistent challenge over the past decades. Therapy of organophosphate poisoning is based on the administration of atropine and oxime as standard antidotes. The present study was undertaken to evaluate the ability of sodium bicarbonate to improve protective effects of standard antidotes in rats poisoned with dichlorvos. The aim of this experiment was to establish the correlation between protective effects and biochemical parameters relevant for acid-base status. In order to examine the protective effect of both standard antidotes and their combinations, groups of experimental animals were poisoned subcutaneously with increasing doses of dichlorvos. Immediately thereafter, rats were treated with atropine 10 mg/kg intramuscularly, oximes 10 mg/kg intramuscularly and sodium bicarbonate 3 mmol/kg intraperitoneally. These antidotes were administered either as single doses or in combinations. In the biochemical part of the experiments, rats were poisoned with dichlorvos 1.3 LD(50) (10.64 mg/kg) subcutaneously and immediately thereafter treated with atropine 10 mg/kg intramuscularly, oximes (trimedoxime or obidoxime) 10 mg/kg intramuscularly and sodium bicarbonate 3 mmol/kg intraperitoneally either as single doses or in combinations. Parameters relevant for acid-base status were measured 10 minutes after the administration of antidotes. The results of our study indicate that addition of sodium bicarbonate to standard antidotes significantly improves protective effects of atropine, obidoxime and trimedoxime. Correlation between protection and biochemical outcome is clearly evident when sodium bicarbonate is being added to atropine. PMID:16445591

Stefanovic, Danka; Antonijevic, Biljana; Bokonjic, Dubravko; Stojiljkovic, Milos P; Milovanovic, Zoran A; Nedeljkovic, Mirjana

2006-02-01

171

Sodium bicarbonate-augmented stress thallium myocardial scintigraphy.  

PubMed

It is well known that sodium bicarbonate in pharmacological doses induces transient alkalosis, causing intracellular transport of serum potassium. The aims of this study were (a) to investigate whether, in humans, myocardial thallium-201 uptake can be augmented by pretreatment with a single bolus of sodium bicarbonate at a pharmacological dose, (b) to verify general safety aspects of the intervention and (c) to evaluate the clinical implications of augmentation of (201)Tl uptake, if any. Routine exercise myocardial scintigraphy was performed twice in eight adult volunteers (five normal and three abnormal), once without intervention and the second time (within a week) following intravenous administration of sodium bicarbonate (88 mEq in 50 ml) as a slow bolus 1 h prior to the injection of (201)Tl. Conventional myocardial thallium study was compared with sodium bicarbonate interventional myocardial scintigraphy with respect to myocardial uptake (counts per minute per mCi injected dose), washout patterns in normal and abnormal myocardial segments, and overall clinical interpretation based on planar and single-photon emission tomographic (SPET) images. All patients remained asymptomatic after the intervention. A mean increase of 53% in myocardial uptake of thallium was noted in post-exercise acquisitions after the intervention, confirming uptake of the tracer via the potassium-hydrogen pump and its augmentation by transient alkalosis. The washout pattern remained unchanged. The visual quality of planar and SPET images improved significantly after the intervention. Out of the five abnormal myocardial segments identified in three cases, four showed significant filling-in after the intervention, causing the diagnosis to be upgraded from "partial scar" to "ischaemia", or from "ischaemia" to "normal". The overall scan impression changed in two out of three such cases. Sodium bicarbonate augmentation may have significant implications for stress-thallium scintigraphy and may be a new parameter for defining myocardial viability. PMID:14673543

Sarin, Badal; Chugh, Pradeep Kumar; Kaushal, Dinesh; Soni, Nakse Lal; Sawroop, Kishan; Mondal, Anupam; Bhatnagar, Aseem

2003-12-12

172

Lipolysis, esterification and glucose oxidation by human omental isolated adipose cells: The effects of pH, buffer and epinephrine  

Microsoft Academic Search

The rates of glycerol productions, glucose oxidation and glucose conversion to glyceride-glycerol by human omental fat cells\\u000a were compared in vitro at pH’s from 7.0 to 8.4, with and without epinephrine, and in both Krebs-Ringer-bicarbonate and-phosphate\\u000a buffers. Basal glycerol production was not significantly altered by changes in pH, and was similar in each buffer. Epinephrine\\u000a markedly increased glycerol production at

B. C. E. Ashley; R. B. Goldrick

1970-01-01

173

Thermal analysis of ammonium diuranate  

Microsoft Academic Search

Thermogravimetric and thermodifferential analyses were used to characterize the behavior during heating of ammonium diuranate (ADU) powders and microspheres. On the basis of a proposed precipitating mechanism of ADU, the main conversion stages of ADU into UâOâ are taken into consideration determining the temperature intervals in which they take place. The approximate composition of intermediate products was also determined. The

C. N. Turcanu; R. Deju

1979-01-01

174

SOURCE ASSESSMENT: AMMONIUM NITRATE PRODUCTION  

EPA Science Inventory

The report describes a study of air pollutants emitted by the ammonium nitrate industry. The potential environmental effect of the source was evaluated. Representative processes and an average plant were defined for the purpose of establishing a base on which to determine the emi...

175

Analysis of Kjeldahl digests by the salicylate method: Optimizing pH and buffering improves both sensitivity and precision  

Microsoft Academic Search

Digest acidity can interfere strongly with ammonium analysis using salicylate?indophenol colorimetry, but many methods over?neutralize acids so that buffering capacity and sensitivity are reduced. To optimize analysis of acidic digests, we replaced the phosphate buffer with salicylate. Base was added stoichiometrically to neutralize acids and dissociate one?half the salicylate to reach the phenolic pKa (approx. 13). Sample flow was 20%

Allen P. Doyle; Joshua P. Schimel

1996-01-01

176

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

177

On the Precipitation of Ammonium Polyvanadate.  

National Technical Information Service (NTIS)

Comparatively few studies have been made on ammonium vanadates, especially ammonium polyvanadates, although they are important intermediates in the industrial production of vanadium pentoxide. The effects of crystallization conditions on the nature and pr...

U. M. Levanto

1969-01-01

178

Facilitation through Buffer Saturation: Constraints on Endogenous Buffering Properties  

PubMed Central

Synaptic facilitation (SF) is a ubiquitous form of short-term plasticity, regulating synaptic dynamics on fast timescales. Although SF is known to depend on the presynaptic accumulation of Ca2+, its precise mechanism is still under debate. Recently it has been shown that at certain central synapses SF results at least in part from the progressive saturation of an endogenous Ca2+ buffer (Blatow et al., 2003), as proposed by Klingauf and Neher (1997). Using computer simulations, we study the magnitude of SF that can be achieved by a buffer saturation mechanism (BSM), and explore its dependence on the endogenous buffering properties. We find that a high SF magnitude can be obtained either by a global saturation of a highly mobile buffer in the entire presynaptic terminal, or a local saturation of a completely immobilized buffer. A characteristic feature of BSM in both cases is that SF magnitude depends nonmonotonically on the buffer concentration. In agreement with results of Blatow et al. (2003), we find that SF grows with increasing distance from the Ca2+ channel cluster, and increases with increasing external Ca2+, [Ca2+]ext, for small levels of [Ca2+]ext. We compare our modeling results with the experimental properties of SF at the crayfish neuromuscular junction, and find that the saturation of an endogenous mobile buffer can explain the observed SF magnitude and its supralinear accumulation time course. However, we show that the BSM predicts slowing of the SF decay rate in the presence of exogenous Ca2+ buffers, contrary to experimental observations at the crayfish neuromuscular junction. Further modeling and data are required to resolve this aspect of the BSM.

Matveev, Victor; Zucker, Robert S.; Sherman, Arthur

2004-01-01

179

Preparation of immunoglobulin Y from egg yolk using ammonium sulfate precipitation and ion exchange chromatography.  

PubMed

The objective of this study was to develop an economical, simple, and large-scale separation method for IgY from egg yolk. Egg yolk diluted with 9 volumes of cold water was centrifuged after adjusting the pH to 5.0. The supernatant was added with 0.01% charcoal or 0.01% carrageenan and centrifuged at 2,800 x g for 30 min. The supernatant was filtered through a Whatman no. 1 filter paper and then the filtrate was concentrated to 20% original volume using ultrafiltration. The concentrated solution was further purified using either cation exchange chromatography or ammonium sulfate precipitation. For the cation exchange chromatography method, the concentrated sample was loaded onto a column equilibrated with 20 mM citrate-phosphate buffer at pH 4.8 and eluted with 200 mM citrate-phosphate buffer at pH 6.4. For the ammonium sulfate precipitation method, the concentrated sample was twice precipitated with 40% ammonium sulfate solution at pH 9.0. The yield and purity of IgY were determined by ELISA and electrophoresis. The yield of IgY from the cation exchange chromatography method was 30 to 40%, whereas that of the ammonium sulfate precipitation was 70 to 80%. The purity of IgY from the ammonium sulfate method was higher than that of the cation exchange chromatography. The cation exchange chromatography could handle only a small amount of samples, whereas the ammonium sulfate precipitation could handle a large volume of samples. This suggests that ammonium sulfate precipitation was a more efficient and useful purification method than cation exchange chromatography for the large-scale preparation of IgY from egg yolk. PMID:17234857

Ko, K Y; Ahn, D U

2007-02-01

180

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

181

Early Vegetative Growth of Tomato Plants in Media Containing Nitrogen Source as Nitrate, Ammonium, or Various Nitrate–Ammonium Mixtures with Bicarbonate Addition  

Microsoft Academic Search

The effect of various concentrations applied in media with , , or various mixtures of both on the accumulation of biomass and early vegetative growth of tomato (Lycopersicon esculentum Mill.) plants was tested in experiments carried out in hydroponics. The optimum concentration was 5 mM and was similar in all the combinations of the N source applied at 3 mM concentration. The

Jan Bialczyk; Zbigniew Lechowski; Andrzej Libik

2005-01-01

182

21 CFR 184.1133 - Ammonium alginate.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-04-01 true Ammonium alginate. 184.1133 Section 184.1133 Food and...Substances Affirmed as GRAS § 184.1133 Ammonium alginate. (a) Ammonium alginate (CAS Reg. No. 9005-34-9) is the...

2010-01-01

183

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

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Buffered penicillin powder, penicillin powder with buffered aqueous diluent. 520...FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered...

2009-04-01

184

Grocery store baking soda. A source of sodium bicarbonate in the management of chronic metabolic acidosis.  

PubMed

Oral sodium bicarbonate is used to treat metabolic acidosis in patients with renal tubular acidosis. Since infants and young children are unable to swallow tablets, those affected must ingest sodium bicarbonate in a powder or liquid form. Pharmacy-weighed sodium bicarbonate is expensive and inconvenient to obtain; some pharmacists are reluctant to provide it. We determined that the sodium bicarbonate contained in 8-oz boxes of Arm and Hammer Baking Soda was sufficiently constant in weight that, dissolved in water to a given volume, it yielded a quantitatively acceptable therapeutic solution of sodium bicarbonate at a cost of approximately 3 percent of that of pharmacy-weighed sodium bicarbonate. Grocery store baking soda can be a safe, economical, and convenient source of sodium bicarbonate for the treatment of chronic metabolic acidosis in infants and young children. PMID:6319065

Booth, B E; Gates, J; Morris, R C

1984-02-01

185

Hierarchical buffered routing tree generation  

Microsoft Academic Search

This paper presents a solution to the problem of per- formance-driven buffered routing tree generation for VLSI cir- cuits. Using a novel bottom-up construction algorithm and a local neighborhood search strategy, our polynomial time algorithm finds the optimum solution in an exponential-size solution sub- space. The final output is a buffered rectilinear Steiner routing tree that connects the driver of

Amir H. Salek; Jinan Lou; Massoud Pedram

2002-01-01

186

Hierarchical Z-buffer visibility  

Microsoft Academic Search

An ideal visibility algorithm should a) quickly reject most of thehidden geometry in a model and b) exploit the spatial and perhapstemporal coherence of the images being generated. Ray castingwith spatial subdivision does well on criterion (a), but poorly oncriterion (b). Traditional Z-buffer scan conversion does well oncriterion (b), but poorly on criterion (a). Here we present a hierarchicalZ-buffer scan-conversion

Ned Greene; Michael Kass; Gavin S. P. Miller

1993-01-01

187

Influence of calcium ions on the crystallization of sodium bicarbonate  

Microsoft Academic Search

In industrial crystallization of sodium bicarbonate (sodium hydrogenocarbonate), the presence of calcium ions in solutions is unavoidable due to the production process. The understanding of the Ca2+ role in NaHCO3 crystallization would be helpful for improving the quality of the final products.The influence of calcium ions on NaHCO3 crystallization was investigated in a 5-l mixed suspension mixed product removal crystallizer

Y. Zhu; Paul Demilie; Perrine Davoine; Thierry Cartage; Marie-Paule Delplancke-Ogletree

2005-01-01

188

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

189

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

190

pH stat studies on bicarbonate secretion in the isolated mouse ileum.  

PubMed

Bicarbonate secretion occurs in almost all segments of the gastrointestinal tract. This study examined HCO(3)(-) secretion in the ileum, since it is less understood than HCO(3)(-) secretion in other intestinal segments. Mouse ileal mucosa was mounted in vitro in Ussing chambers, and the mucosal alkalinization rate (J(OH)) was determined by pH stat titration, while the mucosal side was bathed with a buffer-free solution (100% O(2)) and the serosal side with a HCO(3)(-)/CO(2)-buffered solution. The transmural potential difference (PD) was recorded. The mucosal alkalinization rate (J(OH)) was higher in the presence of mucosal Cl(-) than in its absence. Forskolin, an activator of adenylate cyclase, enhanced J(OH) and PD in both the presence and absence of mucosal Cl(-). Mucosal SO(4)(2-) also caused an increase in J(OH), although the magnitude was smaller than that induced by Cl(-). Mucosal Cl(-)-dependent J(OH) was partially inhibited by acetazolamide, 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), tenidap and probably also by niflumic acid, but not by glibenclamide, DIDS or bumetanide. The forskolin-induced J(OH) value and PD were both inhibited by NPPB and probably also by tenidap. It is concluded that HCO(3)(-)- secretion in the ileum follows a mucosal Cl(-)-dependent pathway and a cAMP-activated pathway, each being distinct from each other. The Cl(-)-dependent pathway is probably mediated by the slc26a6 anion exchanger, and possibly also by the slc26a3 anion exchanger. The cAMP-activated HCO(3)(-) secretion is probably mediated by the cystic fibrosis transmembrane conductance regulator. PMID:18000336

Uchiyama, Hisakazu; Hayashi, Hisayoshi; Tanji, Ken-Ichi; Sugimoto, Osamu; Suzuki, Yuichi

2007-10-01

191

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

192

Bicarbonate-dependent secretion and proteolytic processing of recombinant myocilin.  

PubMed

Myocilin is an extracellular glycoprotein of poorly understood function. Mutations of this protein are involved in glaucoma, an optic neuropathy characterized by a progressive and irreversible visual loss and frequently associated with elevated intraocular pressure. We previously showed that recombinant myocilin undergoes an intracellular proteolytic processing by calpain II which cleaves the central region of the protein, releasing one N- and one C-terminal fragment. Myocilin cleavage is reduced by glaucoma mutations and it has been proposed to participate in intraocular pressure modulation. To identify possible factors regulating the proteolytic processing of recombinant myocilin, we used a cellular model in which we analyzed how different culture medium parameters (i.e., culture time, cell density, pH, bicarbonate concentration, etc.) affect the presence of the extracellular C-terminal fragment. Extracellular bicarbonate depletion associated with culture medium acidification produced a reversible intracellular accumulation of full-length recombinant myocilin and incremented its intracellular proteolytic processing, raising the extracellular C-terminal fragment percentage. It was also determined that myocilin intracellular accumulation depends on its N-terminal region. These data suggest that aqueous humor bicarbonate variations could also modulate the secretion and cleavage of myocilin present in ocular tissues. PMID:23342144

Aroca-Aguilar, José-Daniel; Martínez-Redondo, Francisco; Martín-Gil, Alba; Pintor, Jesús; Coca-Prados, Miguel; Escribano, Julio

2013-01-16

193

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

194

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%...

2009-10-01

195

Comparison of zwitterionic N-alkylaminomethanesulfonic acids to related compounds in the Good buffer series  

PubMed Central

Summary Several N-alkyl and N,N-dialkylaminomethanesulfonic acids were synthesized (as zwitterions and/or sodium salts) to be tested for utility as biological buffers at lower pH levels than existing Good buffer compounds (aminoalkanesulfonates with a minimum of two carbons between amine and sulfonic acid groups as originally described by Norman Good, and in common use as biological buffers). Our hypothesis was that a shorter carbon chain (one carbon) between the amino and sulfonic acid groups should lower the ammonium ion pK a values. The alkylaminomethanesulfonate compounds were synthesized in aqueous solution by reaction of primary or secondary amines with formaldehyde/sodium hydrogensulfite addition compound. The pK a values of the ammonium ions of this series of compounds (compared to existing Good buffers) was found to correlate well with the length of the carbon chain between the amino and sulfonate moeties, with a significant decrease in amine basicity in the aminomethanesulfonate compounds (pK a decrease of 2 units or more compared to existing Good buffers). An exception was found for the 2-hydroxypiperazine series which shows only a small pK a decrease, probably due to the site of protonation in this compound (as confirmed by X-ray crystal structure). X-ray crystallographic structures of two members of the series are reported. Several of these compounds have pK a values that would indicate potential utility for buffering at pH levels below the normal physiological range (pK a values in the range of 3 to 6 without aqueous solubility problems) – a range that is problematic for currently available Good buffers. Unfortunately, the alkylaminomethanesulfonates were found to degrade (with loss of their buffering ability) at pH levels below the pK a value and were unstable at elevated temperature (as when autoclaving) – thus limiting their utility.

Hilliard, Newton P; Chhatre, Suneel A; Timofeeva, Tatiana V; Yakovenko, Andrey A; Dei, Daniel K; Mensah, Enoch A

2010-01-01

196

Supplemental Data in Support of Bicarbonate of Soda Stripping, Phase 1, Volume 2. Fresh Sodium Bicarbonate Paint-Stripping Media, Titration Graphs and Data.  

National Technical Information Service (NTIS)

The data in this supplemental document is to support the Bicarbonate of Soda Stripping - Phase I report. This data was used to calculate the titration endpoints for the fresh and spent sodium bicarbonate paint-stripping media. This information was used to...

J. E. Findley K. L. Gering L. A. Polson M. D. Argyle T. L. Harris

1992-01-01

197

Determination of homologues of quaternary ammonium surfactants by capillary electrophoresis using indirect UV detection  

Microsoft Academic Search

This investigation describes the simultaneous separation of two major non-chromophoric quaternary ammonium surfactants, alkyltrimethyl- and dialkyldimethylammonium compounds (ATMACs and DADMACs, respectively), by capillary electrophoresis (CE) using indirect UV detection. The most effective separation conditions was 10mM phosphate buffer with 57.5% tetrahydrofuran and 3mM sodium dodecyl sulfate (SDS) at pH 4.3, and the sample hydrodynamic injection of up to 20s at

Hsueh-Ying Liu; Wang-Hsien Ding

2004-01-01

198

Bicarbonate assimilation by fresh-water charophytes and higher plants: I. Membrane transport of bicarbonate ions is not proven  

Microsoft Academic Search

Summary Although it is generally believed thatChara and some fresh-water angiosperms transport bicarbonate ions inwards across their plasma membranes, there has been no direct demonstration of such transport in these plants. The (indirect) arguments for their transporting HCO3- are arguments against the inward diffusion of CO2 at the observed rates. They rest on calculations of the equilibrium concentration of CO2

N. A. Walker; F. A. Smith; I. R. Cathers

1980-01-01

199

Electrochemical studies of anodic dissolution of mild steel in a carbonate-bicarbonate buffer under erosion-corrosion conditions  

Microsoft Academic Search

A Rotating Cylinder Electrode (RCE) system has been used to determine the corrosion kinetics of mild steel in the active dissolution potential range under erosion-corrosion conditions. The hydrodynamics of the rotating cylinder electrode were characterized by the mass transfer controlled oxygen reduction reaction on a copper electrode. The anodic dissolution current was measured at various potentials and velocities in de-aerated

S. Zhou; M. M. Stack; R. C. Newman

1996-01-01

200

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

201

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

2007-12-14

202

A robust method for ammonium nitrogen isotopic analysis in freshwater and seawater at natural abundance levels  

NASA Astrophysics Data System (ADS)

Natural ammonium N isotopic abundance has been increasingly used in studies of marine and freshwater biogeochemistry. However, current methods are time-consuming, subject to interference from DON, and not reliable at low concentrations. Our new method for determining the ?15N of ammonium overcomes these difficulties by employing the oxidation of ammonium to nitrite followed by conversion of nitrite to nitrous oxide. In the first step, ammonium is quantitatively oxidized by hypobromite at pH~12. After the addition of sodium arsenite to consume excess hypobromite, yield is verified by colorimetric NO2-measurement using sulfanilamide and naphthyl ethylenediamine (NED). Nitrite is further reduced to N2O by a 1:1 sodium azide and acetic acid buffer solution using previously established procedures. Buffer concentration can be varied according to sample matrix to ensure that a reaction pH between 2 and 4 is reached. The product nitrous oxide is then isotopically analyzed using a continuous flow purge and cryogenic trap system coupled to an isotope ratio mass spectrometer. Reliable ?15N values (±0.31‰) are obtained over a concentration range of 0.5 ?M to 20 ?M using 20 ml volumes of either fresh or seawater samples. Reagent blanks are very low, about 0.05 ?M. There is no interference from any of the nitrogen containing compounds tested except short chain aliphatic amino acid (i.e. glycine) which typically are not present at sufficiently high environmental concentrations to pose a problem.

Zhang, L.; Altabet, M. A.; Wu, T.; Hadas, O.

2006-12-01

203

Establishing conservation buffers using precision information  

Microsoft Academic Search

Conservation buffers, such as filter strips and riparian forest buffers, are widely prescribed to improve and protect water quality in agricultural landscapes. These buffers intercept field runoff and retain some of its pollutant load before it reaches a waterway. A buffer typically is designed to have uniform width along a field margin and to intercept runoff that flows uniformly to

M. G. Dosskey; D. E. Eisenhauer; M. J. Helmers

204

Wire segmenting for improved buffer insertion  

Microsoft Academic Search

Buffer insertion seeks to place buffers on the wires of a signal netto minimize delay. Van Ginneken [Buffer Placement in Distributed RC-tree Networks for Minimal Elmore Delay] proposed an optimal dynamicprogramming solution (with extensions proposed by [7] [8][9] [12]) such that at most one buffer can be placed on a singlewire. This constraint can hurt solution quality, but it may

Charles J. Alpert; Anirudh Devgan

1997-01-01

205

Investigation of crystallization kinetics of sodium bicarbonate in a continuous stirred tank crystallizer  

NASA Astrophysics Data System (ADS)

In our previous work [J. Crystal Growth 263 (2004) 459], a supersaturation determination method using a high-precision densimeter was designed and developed for monitoring sodium bicarbonate supersaturation in the sodium carbonate bicarbonate system, a two-component solution in equilibrium. In the present paper, we apply this method to the study of sodium bicarbonate continuous crystallization. It gives us access to the sodium bicarbonate supersaturation evolution. The sodium bicarbonate supersaturation evolution and their crystallization kinetics obtained in a continuous stirred tank crystallizer are investigated under different operational conditions, such as residence time, initial supersaturation and seeding. The induction time determined by density measurements is discussed. Mathematical modeling is used to interpret the supersaturation evolution. It is shown that measuring the density gives satisfying performances for studying the crystallization of a two-component solution in equilibrium, such as the sodium carbonate bicarbonate system.

Zhu, Yi; Haut, Benoît; Halloin, Veronique; Delplancke-Ogletree, Marie-Paule

2005-08-01

206

Improving Water Quality With Conservation Buffers  

Microsoft Academic Search

Conservation buffer technologies are new approaches that need wider application. In-field buffer practices work best when used in combination with other buffer types and other conservation practices. Vegetative barriers may be used in combination with edge-of-field buffers to protect and improve their function and longevity by dispersing runoff and encouraging sediment deposition upslope of the buffer. It's important to understand

R. Lowrance; S. Dabney; R. Schultz

2003-01-01

207

Impact of supplementation with bicarbonate on lower-extremity muscle performance in older men and women  

PubMed Central

Summary This study describes the impact of bicarbonate treatment for 3 months on net acid excretion (NAE), nitrogen excretion, and muscle performance in older men and women. Bicarbonate reduced NAE, and the decrement was associated with a decrease in nitrogen excretion. Treatment also improved muscle power and endurance in the women. Introduction Bicarbonate enhances muscle performance during strenuous exercise, but its effect on performance during normal activity in older subjects is unknown. Methods In this trial, healthy subjects age 50 and older were randomized to 67.5 mmol of bicarbonate or to no bicarbonate daily for 3 months. Changes in lower-extremity muscle power, endurance, urinary nitrogen, and NAE were compared across treatment groups in the 162 participants included in the analyses. Results In the men and the women, bicarbonate was well tolerated, and as expected, it significantly decreased NAE. The change in NAE correlated with change in nitrogen excretion in women (r=0.32, P=0.002) with a similar trend in men (r=0.23, P=0.052). In the women, bicarbonate increased double leg press power at 70% one repetition maximum by 13% (P=0.003) compared with no bicarbonate and improved other performance measures. Treatment with bicarbonate had no significant effect on muscle performance in the men. Conclusions Ingestion of bicarbonate decreased nitrogen excretion and improved muscle performance in healthy postmenopausal women. The bicarbonate-induced decline in NAE was associated with reduced nitrogen excretion in both men and women. These findings suggest that bicarbonate merits further evaluation as a safe, low-cost intervention that may attenuate age-related loss of muscle performance and mass in the elderly.

Castaneda-Sceppa, C.; Harris, S. S.; Palermo, N. J.; Cloutier, G.; Ceglia, L.; Dallal, G. E.

2010-01-01

208

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

209

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

210

Variability of acid-base status in acetate-free biofiltration 84% versus bicarbonate dialysis.  

PubMed

The ultimate goal of hemodialysis (HD) treatment is to achieve the highest level of efficacy in the presence of maximal clinical tolerance. With an aim to offer good hemodynamic stability, as observed during the acetate-free biofiltration 14% (AFB 14%) to patients who are intolerant to bicarbonate dialysis (BD) and with less cost, we have developed since June 1994, a new HD technique, namely AFB 84%. This study was carried out to analyze acid-base variations during the AFB 84% in comparison to BD in hemodynamically stable patients on regular HD. This was a prospective randomized crossover study carried out on 12 patients (6 males and 6 females) for a total of 144 HD sessions (72 BD and 72 AFB 84%). Patients with decompensated cardiomyopathy, respiratory diseases or uncontrolled hypertension were not included in the trial. All the patients were treated with BD or AFB 84%; the latter is characterized by the absence of acetate in the dialysate and a complete correction of buffer balance by post-dilutional infusion of bicarbonate-based replacement solution. The comparison of pre-dialysis arterial acid-base and blood-gas parameters revealed no significant differences of pH, HCO(3)(-) and paCO(2) levels between the two techniques. Analysis of post-dialysis parameters showed that, among patients dialyzed with BD, there was over correction of metabolic acidosis with a tendency towards metabolic alkalosis. In contrast, in patients dialyzed with AFB 84%, we observed a significant improvement in pH and HCO(3)(-) levels but the increase in paCO(2) level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO(3)(-) and paCO(2) levels, but not for paO(2) level. AFB 84% can offer some important advantages with the complete absence of acetate from the substitution fluids, and permits a better correction of metabolic acidosis than BD, without causing alkalosis. PMID:18310870

Harzallah, Kais; Hichri, Nourredine; Mazigh, Chakib; Tagorti, Mohamed; Hmida, Ahmed; Hmida, Jalel

2008-03-01

211

ANAEROBIC AMMONIUM OXIDATION IN THE MARINE ENVIRONMENT  

Microsoft Academic Search

Oceanographers noticed already many years ago that far less ammonium accumulated in anoxic fjords and basins, than would be\\u000a expected from the stoichiometry of heterotrophic denitrification. It was suggested that this ‘missing’ ammonium was oxidized\\u000a with nitrate to freeN2. Since then several otherworkers have argued based on chemical profiles that ammonium is oxidized anaerobically in oxygen\\u000a deficient marine sediments and

Marcel M. M. Kuypers; Gaute Lavik; Bo Thamdrup

212

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

213

Buffer Capacity in Aquatic Ecosystems.  

National Technical Information Service (NTIS)

Stream water quality and ecological balance can be substantially affected by pH changes. The change in the pH that one would otherwise expect to be induced by the influx of acidic or alkaline wastes can be significantly reduced by the buffering action of ...

F. G. Pohland W. R. Bolton

1974-01-01

214

Buffering New Information during Reading.  

ERIC Educational Resources Information Center

Describes two subject-paced reading experiments in which word-reading times were collected using the moving-window method. Finds that reading times of content words increase more steeply than reading times for function words. Discusses results in terms of buffer models of reading, the processing of different lexical classes, and hypotheses which…

Haberlandt, Karl; Graesser, Arthur C.

1989-01-01

215

Distributed communication via global buffer  

Microsoft Academic Search

Design and implementation of an inter-address-space communication mechanism for the SBN network computer are described. SBN's basic communication primitives appear in context of a new distributed systems programming language strongly supported by the network communication kernel. A model in which all communication takes place via a distributed global buffer results in simplicity, generality and power in the communication primitives. Implementation

David Gelernter; Arthur J. Bernstein

1982-01-01

216

[Buffer capacity of polyproton substances].  

PubMed

Mathematical analysis of protolytic properties of a polyelectrolite with arbitrary set of stepwise dissotiation constants is carried out, based on disintegration of summary titration curves and buffer capacity for basic functions. It is demonstrated, that in some cases (for example, investigation of biomembranes and their components) simplified disintegration variants can be used. Buffer titration curve of biopolymers and biomembranes is a "buffer spectrum", the position of bands on the pH scale, their intensity and half-width being determined by the nature of the object (the quantity and quality of hydrophilic groups and the set of its conformation states). Sharp peaks of the buffer spectrum correspond to the conformation transition of the object, and their half-width on the pH scale determines the cooperative degree of each conformation transition. The mathematical analysis described is not specific to the formation of polyprotonic complex, and it can be used in investigation of the complex formation with any monodentant ligand. It is concluded that the method described can be used in the investigation of complex biomembranes and different processes, in which these membranes participate. PMID:32925

Opanasenko, V K; Gerts, S M; Makarov, A D

1978-08-01

217

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

218

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

NASA Astrophysics Data System (ADS)

Scanning Electron Microscopic (SEM) images of ADU prepared with gaseous ammonia, (a) in presence of excess ammonium nitrate (80 g/L) as well as (b) in absence of excess ammonium nitrate at different magnification.

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

2013-09-01

219

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2012 CFR

...more than 70 percent of ammonium nitrate and a maximum of 0.4 percent combustible material; (2) Ammonium nitrate with calcium carbonate and/or dolomite, containing more than 80 percent but less than 90 percent of ammonium nitrate and a maximum...

2012-10-01

220

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2011 CFR

...more than 70 percent of ammonium nitrate and a maximum of 0.4 percent combustible material; (2) Ammonium nitrate with calcium carbonate and/or dolomite, containing more than 80 percent but less than 90 percent of ammonium nitrate and a maximum...

2011-10-01

221

Hemodynamic Effects of Peritoneal Dialysis Solutions on the Rat Peritoneal Membrane: Role of Acidity, Buffer Choice, Glucose Concentration, and Glucose Degradation Products  

Microsoft Academic Search

Conventional peritoneal dialysis fluids (PDF) are unphysiologic because of their hypertonicity, high glucose and lactate concentrations, acidic pH, and presence of glucose degradation products (GDP). Long-term exposure to conven- tional PDF may cause functional and structural alterations of the peritoneal membrane. New PDF have a neutral pH, a low GDP content, and contain bicarbonate or lactate as the buffer. Intravital

SISKA MORTIER; S. DE VRIESE; JOHAN VAN DE VOORDE; THOMAS P. SCHAUB; JUTTA PASSLICK-DEETJEN; NORBERT H. LAMEIRE

2002-01-01

222

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

223

Low Noise Buffer Amplifiers and Buffered Phase Comparators for Precise Time and Frequency Measurement and Distribution.  

National Technical Information Service (NTIS)

Extremely low noise, high performance, wideband buffer amplifiers and buffered phase comparators have been developed for the NASA Goddard Space Flight Center Atomic Hydrogen Standards Program. These buffer amplifiers are designed to distribute reference f...

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

1981-01-01

224

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

225

Serum Bicarbonate and Mortality in Stage 3 and Stage 4 Chronic Kidney Disease  

PubMed Central

Summary Background and objectives The incidence and prevalence of metabolic acidosis increase with declining kidney function. We studied the associations of both low and high serum bicarbonate levels with all-cause mortality among stage 3 and 4 chronic kidney disease (CKD) patients. Design, setting, participants, & measurements We examined factors associated with low (<23 mmol/L) and high (>32 mmol/L) serum bicarbonate levels using logistic regression models and associations between bicarbonate and all-cause mortality using Cox-proportional hazard models, Kaplan–Meier survival curves, and time-dependent analysis. Results Out of 41,749 patients, 13.9% (n = 5796) had low and 1.6% (n = 652) had high serum bicarbonate levels. After adjusting for relevant covariates, there was a significant association between low serum bicarbonate and all-cause mortality (hazard ratio [HR] 1.23, 95% CI 1.16, 1.31). This association was not statistically significant among patients with stage 4 CKD and diabetes. The time-dependent analysis demonstrated a significant mortality risk associated with a decline from normal to low bicarbonate level (HR 1.59, 95% CI 1.49, 1.69). High serum bicarbonate levels were associated with death irrespective of the level of kidney function (HR 1.74, 95% CI 1.52, 2.00). When serum bicarbonate was examined as a continuous variable, a J-shaped relationship was noted between serum bicarbonate and mortality. Conclusions Low serum bicarbonate levels are associated with increased mortality among stage 3 CKD patients and patients without diabetes. High serum bicarbonate levels are associated with mortality in both stage 3 and stage 4 CKD patients.

Schold, Jesse D.; Arrigain, Susana; Jolly, Stacey E.; Wehbe, Edgard; Raina, Rupesh; Simon, James F.; Srinivas, Titte R.; Jain, Anil; Schreiber, Martin J.; Nally, Joseph V.

2011-01-01

226

21 CFR 556.375 - Maduramicin ammonium.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES...of maduramicin ammonium in chickens as follows: (a) A tolerance...ammonium (marker residue) in chickens is 0.38 parts per million...residues in uncooked edible chicken tissues are: 0.24...

2013-04-01

227

Interaction of polyquaternary ammonium salt and persulfate  

Microsoft Academic Search

An interaction between poly(diallyldimethylammonium chloride) and ammonium persulfate in aqueous solutions has been detected and studied by methods of turbidimetry and viscometry. Investigations were carried out with the cationic polymer of different molecular weight. It was shown that association between low-molecular-weight polyquaternary ammonium salt polycations and persulfate anions was predominant over the chemical (redox) reaction with counterions Cl –. Appreciably

Edita Mazoniene; RimaJule Zemaitaitiene; Gintaras Buika; Algirdas Zemaitaitis

2004-01-01

228

Influence of ammonium uptake on bean nutrition  

Microsoft Academic Search

A glasshouse experiment was carried out in order to study the effect of ammonium supply [0 and 1.5 mmol L in the nutrient solution, whereas total nitrogen (N) concentration was 9.5 mmol L] on nutrient uptake, leaves, and xylem sap composition and growth of bean plants in sand culture. Ammonium supply caused higher nitrogen, phosphorus (P), potassium (K), and calcium

M. J. Sarro; J. M. Sánchez; J. M. Peñalosa

1998-01-01

229

Characteristics of Polarographic Catalytic Waves Observed with Bovine-Serum Albumin: Effects of Type of Buffers, pH, Ionic Strength, Calcium, and Tetraalkyl Salts  

Microsoft Academic Search

Brdicka currents observed with bovine-serum albumin in ammoniacal buffers with Co(III) and Co(II) as catalysts are identical only when the concentrations of ammonia and ammonium chloride are at least 0.5 M and 0.05 M, respectively. When these conditions are not fulfilled, and in all Tris and borate buffers, the pattern of Brdicka currents with Co(III) are quite different from those

I. M. Kolthoff; K. Yamashita; Tan Boen Hie

1974-01-01

230

Agglomeration of Sodium Bicarbonate in Vibrofluidized Bed: Process Analysis and Evaluation of CO2 Release  

Microsoft Academic Search

Agglomeration of sodium bicarbonate in a vibrofluidized bed using an aqueous polymeric suspension as binding agent was studied to determine the effects of vibration parameters (amplitude and frequency) and drying air temperature on process performance and product quality. Product quality was evaluated by determination and comparison of CO2 release from agglomerated and raw sodium bicarbonate. An experimental design was developed

S. C. S. Rocha; J. F. Nunes

2012-01-01

231

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

232

Regulation of Duodenal Bicarbonate Secretion during Stress by Corticotropin-Releasing Factor and beta -endorphin  

Microsoft Academic Search

Proximal duodenal mucosal bicarbonate secretion is an important factor in the pathogenesis of duodenal ulcer disease. To examine the central nervous system regulation of duodenal bicarbonate secretion, an animal model was developed that allowed cerebroventricular and intravenous injections as well as collection of duodenal perfusates in awake, freely moving rats. The hypothalamic peptide corticotropinreleasing factor (CRF) and stress (physical restraint)

H. Jurgen Lenz

1989-01-01

233

46 CFR 58.25-45 - Buffers.  

Code of Federal Regulations, 2012 CFR

...25-45 Buffers. For each vessel on an ocean, coastwise, or Great Lakes voyage, steering gear other than hydraulic must be designed with suitable buffering arrangements to relieve the gear from shocks to the...

2012-10-01

234

46 CFR 58.25-45 - Buffers.  

Code of Federal Regulations, 2011 CFR

...25-45 Buffers. For each vessel on an ocean, coastwise, or Great Lakes voyage, steering gear other than hydraulic must be designed with suitable buffering arrangements to relieve the gear from shocks to the...

2011-10-01

235

Understanding, Deriving, and Computing Buffer Capacity  

NASA Astrophysics Data System (ADS)

The concept of buffer capacity appears in varied disciplines, including bio-, geo-, analytical, and environmental chemistry, physiology, medicine, dentistry, and agriculture. Unfortunately, however, derivation and systematic calculation of buffer capacity is a topic that seems to be neglected in the undergraduate analytical chemistry curriculum. In this work, we give an account of the development of the buffer capacity concept and derive the buffer capacity contribution equations for buffer systems containing mono-, di-, and triprotic weak acids (and their conjugate bases) and aluminum(III), which undergoes hydrolysis. A brief review of pH is provided because pH is involved in applying buffer capacity to the real world. In addition, we discuss evaluation of the equations, numerical approximation of buffer capacity when an analytic solution is not derived, and the mathematical properties of the buffer capacity expressions.

Urbansky, Edward T.; Schock, Michael R.

2000-12-01

236

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Dialkyl dimethyl ammonium carbonate (generic). 721.10099...721.10099 Dialkyl dimethyl ammonium carbonate (generic). (a...generically as dialkyl dimethyl ammonium carbonate (1:1) (PMN...

2009-07-01

237

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Dialkyl dimethyl ammonium carbonate (generic). 721.10099...721.10099 Dialkyl dimethyl ammonium carbonate (generic). (a...generically as dialkyl dimethyl ammonium carbonate (1:1) (PMN...

2013-07-01

238

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...721.10099 Dialkyl dimethyl ammonium carbonate (generic). (a...generically as dialkyl dimethyl ammonium carbonate (1:1) (PMN...

2010-07-01

239

78 FR 32690 - Certain Ammonium Nitrate From Ukraine  

Federal Register 2010, 2011, 2012, 2013

...Review)] Certain Ammonium Nitrate From Ukraine Determination On the basis of the record...order on certain ammonium nitrate from Ukraine would be likely to lead to continuation...entitled Certain Ammonium Nitrate from Ukraine: Investigation No....

2013-05-31

240

A Toxicological Evaluation of Certain Heparin-Quaternary Ammonium Complexes.  

National Technical Information Service (NTIS)

Physical and chemical characterizations show that the heparin-quaternary ammonium salt complexes can be reproducibly prepared from a given lot of a quaternary ammonium salt. Local toxicity studies also indicate that both the tridodecyl methyl ammonium chl...

G. A. Grode J. P. Crowley R. D. Falb R. I. Leininger

1974-01-01

241

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

242

Modified Ammonium Perchlorate Incorporating Potassium, Permanganate, and Dichromate Dopants.  

National Technical Information Service (NTIS)

The present study of ammonium perchlorate which is grown as whisker crystals from porous glass by a recently discovered process is extended to doped ammonium perchlorate. The selection of dopants in whisker ammonium perchlorate is limited initially to tho...

A. Adicoff W. M. Ayres M. E. Hills W. R. McBride

1971-01-01

243

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2011 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

244

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2012 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

245

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Aluminum ammonium sulfate. 182.1127 Section 182.1127...Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of use....

2009-04-01

246

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Aluminum ammonium sulfate. 582.1127 Section 582.1127...Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions of use....

2009-04-01

247

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

248

Effect of lactate supplementation and sodium bicarbonate on 40 km cycling time trial performance.  

PubMed

The use of nutritional supplements to improve sporting performance and increase training adaptations is commonplace amongst athletes and is an expanding market in terms of product choice and availability. The purpose of this study was to examine the effects of two ergogenic aids with extracellular blood buffering potential, namely sodium bicarbonate (NaHCO3) and a lactate supplement, during a 40 km cycling time trial. Seven recreationally active males (age, 22.3 ± 3.3 years; height, 182.5 ± 6.5 cm; body mass, 79.2 ± 6.3 kg) completed five 40 km cycling time trials, including a familiarization trial in a randomized blind double placebo design. Subjects ingested either 1.) 300 mg per kg body mass NaHCO3 (BICARB), 2.) 45 mg per kg sodium chloride (PL-BICARB) as the placebo for the NaHCO3 trial, 3.) 21.5 mg per kg body mass lactate supplement (LACTATE) and 4.) plain flour as the placebo for the lactate trial (PL-LACTATE) 60 minutes before exercise. There was no significant difference in performance between the four conditions (p> 0.05). Whilst NaHCO3 ingestion induced significant changes in all the acid-base variables (all p< 0.05), no significant change was seen following lactate ingestion (p> 0.05). Subjects in the LACTATE condition did have a significantly higher heart rate (p< 0.05) without experiencing any greater perceived exertion (p> 0.05) than the other three conditions. Neither NaHCO3 nor lactate supplementation appear to improve 40 km cycling time trial performance. However the potential benefits following LACTATE regarding perceived exertion require further research. PMID:23660571

Northgraves, Matthew J; Peart, Daniel J; Jordan, Christian; Vince, Rebecca V

2013-05-01

249

Examining the Distribution of Buffer Protection  

Microsoft Academic Search

This paper examines the stochastic behavior of buffer protection (in-process inventory storage) in an 2V-machine single-buffer series system. The approach is specifically developed for unbalanced production lines (i.e., the minimum production rate of those machines preceding the buffer is different than the minimum production rate of those machines following the buffer). For the case of exponential uptimes and general downtimes,

Richard A. Murphy

1979-01-01

250

Legitimate Skew Clock Routing with Buffer Insertion  

Microsoft Academic Search

In this paper, we propose a new quick and effective legitimate skew clock routing with buffer insertion algorithm. We analyze\\u000a the optimal buffer position in the clock path, and conclude the sufficient condition and heuristic condition for buffer insertion\\u000a in clock net. During the routing process, this algorithm integrates buffer insertion and node merging together, and performs\\u000a them in parallel.

Xinjie Wei; Yici Cai; Meng Zhao; Xianlong Hong

2006-01-01

251

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.

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

1988-01-01

252

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...

253

Baroresistant buffer mixtures for biochemical analyses  

Microsoft Academic Search

Hydrostatic pressure is a useful tool in the study of varied fields such as protein aggregation, association, folding, ligand binding, and allostery. Application of pressure can have a significant effect on the pKa values of buffers commonly used for biochemical analysis. Consequently, cationic buffers, rather than neutral ones, are generally used to minimize pH effects; however, even with these buffers,

R. Jason Quinlan; Gregory D. Reinhart

2005-01-01

254

Buffer management in relational database systems  

Microsoft Academic Search

The hot-set model, characterizing the buffer requirements of relational queries, is presented. This model allows the system to determine the optimal buffer space to be allocated to a query; it can also be used by the query optimizer to derive efficient execution plans accounting for the available buffer space, and by a query scheduler to prevent thrashing. The hot-set model

Giovanni Maria Sacco; Mario Schkolnick

1986-01-01

255

Buffer sizing for congested Internet links  

Microsoft Academic Search

Packet buffers in router\\/switch interfaces constitute a central element of packet networks. The appropriate sizing of these buffers is an important and open research problem. Much of the previous work on buffer sizing modeled the traffic as an exogenous process, i.e., independent of the network state, ignoring the fact that the offered load from TCP flows depends on delays and

Amogh Dhamdhere; Hao Jiang; Constantinos Dovrolis

2005-01-01

256

Doped LZO buffer layers for laminated conductors  

SciTech Connect

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

2010-03-23

257

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

258

Ammonium assimilation by Candida albicans and other yeasts: evidence for activity of glutamate synthase.  

PubMed

Activities and properties of the ammonium assimilation enzymes NADP+-dependent glutamate dehydrogenase (GDH), glutamate synthase (GOGAT) and glutamine synthetase (GS) were determined in batch and continuous cultures of Candida albicans. NADP+-dependent GDH activity showed allosteric kinetics, with an S0.5 for 2-oxoglutarate of 7.5 mM and an apparent Km for ammonium of 5.0 mM. GOGAT activity was affected by the buffer used for extraction and assay, but in phosphate buffer, kinetics were hyperbolic, yielding Km values for glutamine of 750 microM and for 2-oxoglutarate of 65 microM. The enzymes GOGAT and NADP+-dependent GDH were also assayed in batch cultures of Saccharomyces cerevisiae and three other pathogenic Candida spp.: Candida tropicalis, Candida pseudotropicalis and Candida parapsilosis. Evidence is presented that GS/GOGAT is a major pathway for ammonium assimilation in Candida albicans and that this pathway is also significant in other Candida species. PMID:2575653

Holmes, A R; Collings, A; Farnden, K J; Shepherd, M G

1989-06-01

259

Glyphosate detection with ammonium nitrate and humic acids as potential interfering substances by pulsed voltammetry technique.  

PubMed

Pulsed voltammetry has been used to detect and quantify glyphosate on buffered water in presence of ammonium nitrate and humic substances. Glyphosate is the most widely used herbicide active ingredient in the world. It is a non-selective broad spectrum herbicide but some of its health and environmental effects are still being discussed. Nowadays, glyphosate pollution in water is being monitored but quantification techniques are slow and expensive. Glyphosate wastes are often detected in countryside water bodies where organic substances and fertilizers (commonly based on ammonium nitrate) may also be present. Glyphosate also forms complexes with humic acids so these compounds have also been taken into consideration. The objective of this research is to study the interference of these common pollutants in glyphosate measurements by pulsed voltammetry. The statistical treatment of the voltammetric data obtained lets us discriminate glyphosate from the other studied compounds and a mathematical model has been built to quantify glyphosate concentrations in a buffer despite the presence of humic substances and ammonium nitrate. In this model, the coefficient of determination (R(2)) is 0.977 and the RMSEP value is 2.96×10(-5) so the model is considered statistically valid. PMID:24054650

Martínez Gil, Pablo; Laguarda-Miro, Nicolas; Camino, Juan Soto; Peris, Rafael Masot

2013-06-25

260

21 CFR 172.165 - Quaternary ammonium chloride combination.  

Code of Federal Regulations, 2013 CFR

...FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.165 Quaternary ammonium chloride combination. The food additive, quaternary ammonium chloride...

2013-04-01

261

Storage of Anthropogenic Carbon Dioxide as Ocean Bicarbonate  

NASA Astrophysics Data System (ADS)

Fossil fuels will likely remain the world's primary energy source for the foreseeable future. Practical and safe means of lowering the associated CO2 emissions are therefore needed to avoid potentially catastrophic climate and environmental impacts. The ocean should not be ignored in assessing both CO2 effects and mitigation options. Accelerated weathering of limestone (AWL) is a candidate technology that could significantly contribute to lowering CO2 emissions as well as to chemically mitigating the effects of ocean acidification. Our research has shown that contacting flue gas (from fossil fuel combustion) with seawater and limestone presents a simple, low-tech way of spontaneously reacting CO2 out of waste gas streams to form a bicarbonate-rich solution via the reaction: CO2 + CaCO3 + H2O <--> Ca2+ + 2HCO3-. (An analogous seawater process is already commercially used in some locations to remove flue gas SOx.) Our modeling studies show that disposing of the resulting calcium bicarbonate-rich solution in the ocean would provide effective, long-term carbon sequestration. It would also add carbonate alkalinity, thus countering the effects of CO2-caused ocean acidification on corals, shellfish, and other calcifying marine organisms. AWL reactors could be optimized for carbon storage or for mitigation of ocean acidification. Experiments have shown that seawater can tolerate >18x saturation before calcium carbonate precipitation is chemically initiated. It is therefore unlikely that once AWL effluent is in the ocean that degassing of some residual CO2 would lead to a reversal of the above reaction and subsequent carbonate precipitation. It is proposed that the cost, safety, impacts, and effectiveness of AWL be further evaluated as a means of mitigating CO2 from point sources, and of reducing the loss of marine calcification.

Rau, G. H.; Caldeira, K.

2006-12-01

262

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 ...

263

Structural study of ammonium metatungstate  

NASA Astrophysics Data System (ADS)

Several techniques have been used to study the structure of the Keggin-type polyoxometalate salt ammonium metatungstate (AMT)—(NH4)6[H2W12O40]*nH2O, 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?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.

Christian, Joel B.; Whittingham, M. Stanley

2008-08-01

264

Chloride-Bicarbonate Exchange in Red Blood Cells: Physiology of Transport and Chemical Modification of Binding Sites  

Microsoft Academic Search

About 80% of the CO_2 formed by metabolism is transported from tissues to lungs as bicarbonate ions dissolved in the water phases of red cells and plasma. The catalysed hydration of CO_2 to bicarbonate takes place in the erythrocytes but most of the bicarbonate thus formed must be exchanged with extracellular chloride to make full use of the carbon dioxide

J. O. Wieth; O. S. Andersen; J. Brahm; P. J. Bjerrum; C. L. Borders Jr.

1982-01-01

265

Substrate specificity of Rhbg: ammonium and methyl ammonium transport  

PubMed Central

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 (pHi) changes and whole cell currents. Our data showed that in Rhbg oocytes, NH3/NH4+ caused an inward current and decrease in pHi 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 pHi. MA/MA+ did not cause any changes in H2O-injected oocytes. The MA/MA+-induced current and pHi increase were saturated at higher concentrations of MA/MA+. Amiloride inhibited MA/MA+-induced current and the increase in pHi 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.

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

2010-01-01

266

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

267

Improving Water Quality With Conservation Buffers  

NASA Astrophysics Data System (ADS)

Conservation buffer technologies are new approaches that need wider application. In-field buffer practices work best when used in combination with other buffer types and other conservation practices. Vegetative barriers may be used in combination with edge-of-field buffers to protect and improve their function and longevity by dispersing runoff and encouraging sediment deposition upslope of the buffer. It's important to understand how buffers can be managed to help reduce nutrient transport potential for high loading of nutrients from manure land application sites, A restored riparian wetland buffer retained or removed at least 59 percent of the nitrogen and 66 percent of the phosphorus that entered from an adjacent manure land application site. The Bear Creek National Restoration Demonstration Watershed project in Iowa has been the site of riparian forest buffers and filter strips creation; constructed wetlands to capture tile flow; stream-bank bioengineering; in-stream structures; and controlling livestock grazing. We need field studies that test various widths of buffers of different plant community compositions for their efficacy in trapping surface runoff, reducing nonpoint source pollutants in subsurface waters, and enhancing the aquatic ecosystem. Research is needed to evaluate the impact of different riparian grazing strategies on channel morphology, water quality, and the fate of livestock-associated pathogens and antibiotics. Integrating riparian buffers and other conservation buffers into these models is a key objective in future model development.

Lowrance, R.; Dabney, S.; Schultz, R.

2003-12-01

268

Microbially mediated clinoptilolite regeneration in a multifunctional permeable reactive barrier used to remove ammonium from landfill leachate contamination: laboratory column evaluation.  

PubMed

This study focuses on multifunctional permeable reactive barrier (multibarrier) technology, combining microbial degradation and abiotic ion exchange processes for removal of ammonium from landfill leachate contamination. The sequential multibarrier concept relies on the use of a clinoptilolite-filled buffer compartment to ensure a robust ammonium removal in case of temporary insufficient microbial activities. An innovative strategy was developed to allow in situ clinoptilolite regeneration. Laboratory-scale clinoptilolite-filled columns were first saturated with ammonium, using real landfill leachate as well as synthetic leachates as feed media. Other inorganic metal cations, typically present in landfill leachate, had a detrimental influence on the ammonium removal capacity by competing for clinoptilolite exchange sites. On the other hand, the metals had a highly favorable impact on regeneration of the saturated material. Feeding the columns with leachate deprived from ammonium (e.g., by microbial nitrification in an upgradient compartment), resulted in a complete release of the previously sorbed ammonium from the clinoptilolite, due to exchange with metal cations present in the leachate. The released ammonium is then available for microbial consumption in a downgradient compartment. The regeneration process resulted in a slightly increased ammonium exchange capacity afterward. The described strategy throws a new light on sustainable use of sorption materials for in situ groundwater remediation, by avoiding the need for material replacement and the use of external chemical regenerants. PMID:20387879

Nooten, Thomas Van; Diels, Ludo; Bastiaens, Leen

2010-05-01

269

Experimental acidification of two biogeochemically-distinct neotropical streams: buffering mechanisms and macroinvertebrate drift.  

PubMed

Research into the buffering mechanisms and ecological consequences of acidification in tropical streams is lacking. We have documented seasonal and episodic acidification events in streams draining La Selva Biological Station, Costa Rica. Across this forested landscape, the severity in seasonal and episodic acidification events varies due to interbasin groundwater flow (IGF). Streams that receive IGF have higher concentrations of solutes and more stable pH (~6) than streams that do not receive IGF (pH ~5). To examine the buffering capacity and vulnerability of macroinvertebrates to short-term acidification events, we added hydrochloric acid to acidify a low-solute, poorly buffered (without IGF) and a high-solute, well buffered stream (with IGF). We hypothesized that: 1) protonation of bicarbonate (HCO(3)(-)) would neutralize most of the acid added in the high-solute stream, while base cation release from the sediments would be the most important buffering mechanism in the low-solute stream; 2) pH declines would mobilize inorganic aluminum (Ali) from sediments in both streams; and 3) pH declines would increase macroinvertebrate drift in both streams. We found that the high-solute stream neutralized 745 ?eq/L (96% of the acid added), while the solute poor stream only neutralized 27.4 ?eq/L (40%). Protonation of HCO(3)(-) was an important buffering mechanism in both streams. Base cation, Fe(2+), and Ali release from sediments and protonation of organic acids also provided buffering in the low-solute stream. We measured low concentrations of Ali release in both streams (2-9 ?eq/L) in response to acidification, but the low-solute stream released double the amount Ali per 100 ?eq of acid added than the high solute stream. Macroinvertebrate drift increased in both streams in response to acidification and was dominated by Ephemeroptera and Chironomidae. Our results elucidate the different buffering mechanisms in tropical streams and suggest that low-solute poorly buffered streams might be particularly vulnerable to episodic acidification. PMID:23201647

Ardón, Marcelo; Duff, John H; Ramírez, Alonso; Small, Gaston E; Jackman, Alan P; Triska, Frank J; Pringle, Catherine M

2012-11-28

270

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

271

Effect of bicarbonate on the growth of Actinobacillus actinomycetemcomitans in anaerobic fructose-limited chemostat culture.  

PubMed

The effect of bicarbonate on the growth and product formation by a periodontopathic bacterium, Actinobacillus actinomycetemcomitans, was examined in an anaerobic chemostat culture with fructose as the limiting nutrient. The chemostat cultures were run at dilution rates between 0.04 and 0.25 h-1 and the maximum growth yield (Ymax fructose) was estimated to be 40.3 and 61.7 g dry wt (mol fructose)-1 in the absence and presence of bicarbonate, respectively. The major fermentation products in the absence of bicarbonate were formate, acetate, ethanol and succinate, with small amounts of lactate. The addition of bicarbonate to the medium resulted in a marked decrease in ethanol production and in a significant increase in succinate production. Washed cells possessed activity for the cleavage of formate to CO2 and H2, which seemed to play a role in supplying CO2 for the synthesis of succinate in the absence of bicarbonate. The study of enzyme activities in cell-free extracts suggested that fructose was fermented by the Embden-Meyerhof-Parnas pathway. The values of Ymax ATP and the efficiency of ATP generation (ATP-Eff) during fructose catabolism were estimated and higher values were obtained for the culture in the presence of bicarbonate: 20.2 g dry wt (mol ATP)-1 and 3.0 mol ATP (mol fructose)-1, respectively, versus Ymax ATP = 15.1 and ATP-Eff = 2.7 in the absence of bicarbonate. PMID:2517636

Ohta, H; Fukui, K; Kato, K

1989-12-01

272

76 FR 46907 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...Department of Homeland Security/NPPD'' in the subject line...by the minimal security benefit gained...ammonium nitrate in their products...recreational centers, schools, and other entities...while gaps in security of the...

2011-08-03

273

21 CFR 184.1138 - Ammonium chloride.  

Code of Federal Regulations, 2013 CFR

...Ammonium chloride is crystallized from the solution. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 20, which is incorporated by reference. Copies are available from the National Academy Press,...

2013-04-01

274

21 CFR 184.1143 - Ammonium sulfate.  

Code of Federal Regulations, 2013 CFR

...sulfate ((NH4 )2 SO4 , CAS Reg. No. 7783-20-2) occurs naturally and consists of colorless or white, odorless crystals or granules. It is prepared by the neutralization of sulfuric acid with ammonium hydroxide. (b) The...

2013-04-01

275

21 CFR 558.340 - Maduramicin ammonium.  

Code of Federal Regulations, 2013 CFR

...PRODUCTS NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS Specific New Animal Drugs for Use in Animal Feeds § 558.340 Maduramicin ammonium... (ii) Limitations. For broiler chickens only. Feed continuously as sole ration. Do not...

2013-04-01

276

Decomposition of Four Ammonium Nitrate Propellants.  

National Technical Information Service (NTIS)

The biodegradability of four ammonium nitrate propellants, trimethylammonium nitrate (TMAN), isopropylammonium nitrate (IPAN), triethanolammonium nitrate (TEAN), and hydroxylammonium nitrate (HAN) was assessed in batch and continuous cultures under a vari...

D. L. Kaplan D. J. Emerson P. A. Riley A. M. Kaplan

1983-01-01

277

Granulation of Uranium Trioxide and Ammonium Diuranate.  

National Technical Information Service (NTIS)

The possibilities of the granulation in small laboratory scale of the uranium trioxide and ammonium diuranate were examined. For the uranium trioxide it was stated, that the most advantageous results were obtained by means of the granulation with rotary p...

R. Wlodarski Z. Nowakowska

1975-01-01

278

Pore mutations in ammonium transporter AMT1 with increased electrogenic ammonium transport activity  

Microsoft Academic Search

AMT\\/Mep ammonium transporters mediate high affinity ammonium\\/ammonia uptake in bacteria, fungi, and plants. The Arabidopsis AMT1 proteins mediate uptake of the ionic form of ammonium. AMT transport activity is controlled allosterically via a highly conserved cytosolic C terminus that interacts with neighboring subunits in a trimer. The C terminus is thus capable of modulating the conductivity of the pore. To

D. Loqué; S. I. Mora; S. L. A. Andrade; O. Pantoja; W. B. Frommer

2009-01-01

279

Key Physiology of Anaerobic Ammonium Oxidation  

Microsoft Academic Search

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

MARC STROUS; J. GIJS KUENEN; MIKE S. M. JETTEN

1999-01-01

280

Consolidated bioprocessing of sugarcane bagasse and chicken manure to ammonium carboxylates by a mixed culture of marine microorganisms  

Microsoft Academic Search

The MixAlco process, an example of consolidated bioprocessing (CBP), was utilized for anaerobic fermentation of 80% lime-treated sugarcane bagasse\\/20% chicken manure at 55°C by a mixed culture of marine microorganisms. NH4HCO3 was recommended by this study to replace CaCO3 buffer to neutralize the produced carboxylic acids. The resulting ammonium carboxylates can be converted to gasoline or mixed alcohol fuels by

Zhihong Fu; Mark T. Holtzapple

2010-01-01

281

Determination of chromium(III) and chromium(VI) by ammonium pyrrolidinecarbodithioate-methyl isobutyl ketone furnace atomic absorption spectrometry  

Microsoft Academic Search

The solution conditions and other parameters affecting the ammonium pyrrolidinecarbodithioate-methyl isobutyl ketone (APCD-MIBK) extraction system for the graphite furnace atomic absorption spectrometric determination of Cr(III) and Cr(VI) have been studied in detail. The parameters studied include pH of the aqueous phase prior to extraction, concentration of APDC, concentration of the potassium hydrogen phthalate buffer, the length of time needed for

Kunnath S. Subramanian

1988-01-01

282

The effect of calcium bicarbonate on iron absorption and distribution by Chrysanthemum morifolium , (Ram.)  

Microsoft Academic Search

Summary  Plants grown for two weeks in high-bicarbonate nutrient solution with iron became chlorotic, absorbed less iron, and translocated\\u000a a lower percentage of absorbed iron than did green plants grown under low bicarbonate with iron. Chlorotic plants, pretreated\\u000a in low-bicarbonate solutions lacking iron, absorbed more iron and translocated a higher percentage to leaves than the green\\u000a plants.\\u000a \\u000a Plants induced to chlorosis

Rufus B. Rutland; M. J. Bukovac

1971-01-01

283

The carbonylation and covalent dimerization of human superoxide dismutase 1 caused by its bicarbonate-dependent peroxidase activity is inhibited by the radical scavenger tempol.  

PubMed

Tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl) reduces tissue injury in animal models of various diseases via mechanisms that are not completely understood. Recently, we reported that high doses of tempol moderately increased survival in a rat model of ALS (amyotrophic lateral sclerosis) while decreasing the levels of oxidized hSOD1 (human Cu,Zn-superoxide dismutase) in spinal cord tissues. To better understand such a protective effect in vivo, we studied the effects of tempol on hSOD1 oxidation in vitro. The chosen oxidizing system was the bicarbonate-dependent peroxidase activity of hSOD1 that consumes H2O2 to produce carbonate radical, which oxidizes the enzyme. Most of the experiments were performed with 30 ?M hSOD1, 25 mM bicarbonate, 1 mM H2O2, 0.1 mM DTPA (diethylenetriaminepenta-acetic acid) and 50 mM phosphate buffer at a final pH of 7.4. The results showed that tempol (5-75 ?M) does not inhibit hSOD1 turnover, but decreases its resulting oxidation to carbonylated and covalently dimerized forms. Tempol acted by scavenging the carbonate radical produced and by recombining with hSOD1-derived radicals. As a result, tempol was consumed nearly stoichiometrically with hSOD1 monomers. MS analyses of turned-over hSOD1 and of a related peptide oxidized by the carbonate radical indicated the formation of a relatively unstable adduct between tempol and hSOD1-Trp32•. Tempol consumption by the bicarbonate-dependent peroxidase activity of hSOD1 may be one of the reasons why high doses of tempol were required to afford protection in an ALS rat model. Overall, the results of the present study confirm that tempol can protect against protein oxidation and the ensuing consequences. PMID:23855710

Queiroz, Raphael F; Paviani, Verônica; Coelho, Fernando R; Marques, Emerson F; Di Mascio, Paolo; Augusto, Ohara

2013-10-01

284

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

285

A Bicarbonate Cofactor Modulates 1,4-Dihydroxy-2-naphthoyl-Coenzyme A Synthase in Menaquinone Biosynthesis of Escherichia coli*  

PubMed Central

1,4-Dihydroxy-2-naphthoyl coenzyme A (DHNA-CoA) synthase is a typical crotonase-fold protein catalyzing an intramolecular Claisen condensation in the menaquinone biosynthetic pathway. We have characterized this enzyme from Escherichia coli and found that it is activated by bicarbonate in a concentration-dependent manner. The bicarbonate binding site has been identified in the crystal structure of a virtually identical ortholog (96.8% sequence identity) from Salmonella typhimurium through comparison with a bicarbonate-insensitive orthologue. Kinetic properties of the enzyme and its site-directed mutants of the bicarbonate binding site indicate that the exogenous bicarbonate anion is essential to the enzyme activity. With this essential catalytic role, the simple bicarbonate anion is an enzyme cofactor, which is usually a small organic molecule derived from vitamins, a metal ion, or a metal-containing polyatomic anionic complex. This finding leads to classification of the DHNA-CoA synthases into two evolutionarily conserved subfamilies: type I enzymes that are bicarbonate-dependent and contain a conserved glycine at the bicarbonate binding site; and type II enzymes that are bicarbonate-independent and contain a conserved aspartate at the position similar to the enzyme-bound bicarbonate. In addition, the unique location of the enzyme-bound bicarbonate allows it to be proposed as a catalytic base responsible for abstraction of the ?-proton of the thioester substrate in the enzymatic reaction, suggesting a unified catalytic mechanism for all DHNA-CoA synthases.

Jiang, Ming; Chen, Minjiao; Guo, Zu-Feng; Guo, Zhihong

2010-01-01

286

Comparative shell buffering properties correlate with anoxia tolerance in freshwater turtles.  

PubMed

Freshwater turtles as a group are more resistant to anoxia than other vertebrates, but some species, such as painted turtles, for reasons not fully understood, can remain anoxic at winter temperatures far longer than others. Because buffering of lactic acid by the shell of the painted turtle is crucial to its long-term anoxic survival, we have tested the hypothesis that previously described differences in anoxia tolerance of five species of North American freshwater turtles may be explained at least in part by differences in their shell composition and buffering capacity. All species tested have large mineralized shells. Shell comparisons included 1) total shell CO2 concentration, 2) volume of titrated acid required to hold incubating shell powder at pH 7.0 for 3 h (an indication of buffer release from shell), and 3) lactate concentration of shell samples incubated to equilibrium in a standard lactate solution. For each measurement, the more anoxia-tolerant species (painted turtle, Chrysemys picta; snapping turtle, Chelydra serpentina) had higher values than the less anoxia-tolerant species (musk turtle, Sternotherus odoratus; map turtle, Graptemys geographica; red-eared slider, Trachemys scripta). We suggest that greater concentrations of accessible CO2 (as carbonate or bicarbonate) in the more tolerant species enable these species, when acidotic, to release more buffer into the extracellular fluid and to take up more lactic acid into their shells. We conclude that the interspecific differences in shell composition and buffering can contribute to, but cannot explain fully, the variations observed in anoxia tolerance among freshwater turtles. PMID:17008457

Jackson, Donald C; Taylor, Sarah E; Asare, Vivian S; Villarnovo, Dania; Gall, Jonathan M; Reese, Scott A

2006-09-28

287

Leaching kinetics of malachite in ammonium carbonate solutions  

NASA Astrophysics Data System (ADS)

Leaching of malachite was conducted with ammonium carbonate as lixiviant and with temperature, lixiviant concentration, and particle size as variables. Two stages of reaction were found. In Stage I, the initial dissolution of malachite proceeds rapidly, but after about 10 pct reaction the rate is reduced by surface blockage due to the presence of a needle-structured intermediate, presumably Cu(OH)2. Subsequently, malachite and the intermediate dissolve concurrently. In Stage II, after 90 pct reaction, essentially all of the malachite has dissolved and only the intermediate remains. It dissolves in Stage II. The activation energy is 64 kJ/mole (15.3 kcal/mole) for Stage I and 75 kJ/mole (18 kcal/mole) for Stage II. The rate of reaction in Stage I is proportional to the reciprocal of particle size and is 0.8 order with respect to the concentration of ammonium carbonate. The structures of leaching residues were studied using a scanning electron microscope. The kinetic data (activation energy and entropy), particle size and concentration dependence, residue morphology, and general leaching behavior evident from microscopic monitoring during leaching were used to develop the geometric equation for leaching in Stage I. The equation, based on a heterogeneous reaction with geometric rate control, is: 1 - (1 - ? 1/3 = K01/r0/[(NH4)2C03]0.8 exp(-64,000/RT)t. It was deduced that initial steps in reaction were: (1) release of Cu2+ from malachite; (2) initial complexing with ammonia to form Cu(NH3)2+; and (3) subsequent complexing to produce Cu(NH3){4/2+} which is stable in solution at pH 8.8, the buffered pH of reaction. Stage II appears to be a similar reaction except that the reaction obeys cylindrical geometry instead of spherical geometry as in Stage I.

Oudenne, Paul D.; Olson, Ferron A.

1983-03-01

288

Possible contribution of skeletal muscle buffers to enhanced anaerobic performance: a brief review.  

PubMed

Sprint-trained athletes demonstrate a remarkable ability to perform exercise which results in fatigue quickly. However, the mechanisms for these enhanced performance capabilities have not been fully elucidated. Elevation in glycolytic enzymes and increased fast-twitch fiber compositions which would result in an enhanced ability to produce ATP do not appear to be capable of accounting for the greatly enhanced performances. Associated with these performances are large accumulations of anaerobic end products which produce decrements in intracellular pH. Because intracellular pH decrements of sufficient magnitude have been shown to inhibit athletic performances, it has been postulated that sprint-trained athletes have an enhanced proton-sequestering capability which would ultimately alter the rate of pH decrement. This would delay the inhibition of the enzymatic and contractile machinery resulting in enhanced performances. The intracellular buffers that are capable of contributing to this enhanced buffering capacity were identified as inorganic phosphate, protein-bound histidine residues, the dipeptide carnosine, bicarbonate, and creatine phosphate. Thus, it has been suggested that increased buffer capacities within sprint-trained athletes may be a contributing factor to his/her enhanced anaerobic performance capacities. PMID:6092820

Parkhouse, W S; McKenzie, D C

1984-08-01

289

Antimicrobial activity of borate-buffered solutions.  

PubMed Central

A minimal salts medium adjusted to physiological pH and osmolality was buffered with either 0.3% phosphate or 1.2% borate and evaluated for antimicrobial activity. The borate-buffered medium, either with or without a carbon source, exhibited significant antimicrobial activity against 15 Pseudomonas strains, 12 strains of enteric bacteria, and 7 strains of staphylococci. The borate-buffered system appears suitable for use as a generic vehicle for ophthalmic pharmaceutical agents.

Houlsby, R D; Ghajar, M; Chavez, G O

1986-01-01

290

Potassium buffering in the central nervous system  

Microsoft Academic Search

Rapid changes in extracellular K+ concentration ([K+]o) in the mammalian CNS are counteracted by simple passive diffusion as well as by cellular mechanisms of K+ clearance. Buffering of [K+]o can occur via glial or neuronal uptake of K+ ions through transporters or K+-selective channels. The best studied mechanism for [K+]o buffering in the brain is called K+ spatial buffering, wherein

P. Kofuji; E. A. Newman

2004-01-01

291

Unit 8: Buffers for Biochemical Reactions  

NSDL National Science Digital Library

The last of an eight-unit teaching and training module from Promega, this "introductory buffers laboratory is for use in undergraduate or highschool courses that cover basic topics in molecular biology or biochemistry" and includes "laboratories to illustrate basic chemistry concepts related to buffers and their functions." This unit is math-intensive, aimed at helping students feel comfortable performing laboratory calculations. It includes a lecture presentation ("Buffers for Biological Systems") and a students' and instructors' laboratory protocol.

2013-07-05

292

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."

293

Bicarbonate activation of adenylyl cyclase via promotion of catalytic active site closure and metal recruitment  

PubMed Central

In an evolutionarily conserved signaling pathway, ‘soluble’ adenylyl cyclases (sACs) synthesize the ubiquitous second messenger cyclic adenosine 3?,5?-monophosphate (cAMP) in response to bicarbonate and calcium signals. Here, we present crystal structures of a cyanobacterial sAC enzyme in complex with ATP analogs, calcium and bicarbonate, which represent distinct catalytic states of the enzyme. The structures reveal that calcium occupies the first ion-binding site and directly mediates nucleotide binding. The single ion–occupied, nucleotide-bound state defines a novel, open adenylyl cyclase state. In contrast, bicarbonate increases the catalytic rate by inducing marked active site closure and recruiting a second, catalytic ion. The phosphates of the bound substrate analogs are rearranged, which would facilitate product formation and release. The mechanisms of calcium and bicarbonate sensing define a reaction pathway involving active site closure and metal recruitment that may be universal for class III cyclases.

Steegborn, Clemens; Litvin, Tatiana N; Levin, Lonny R; Buck, Jochen; Wu, Hao

2013-01-01

294

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

295

The ecophysiological significance of calcium bicarbonate in the urine of subterranean rodents: testing a hypothesis.  

PubMed

1. A comparative study of calcium and bicarbonate in the urine was carried out on the subterranean mole rat Cryptomys hottenttus and the terrestrial vlei rat Otomys irroratus. 2. The two species were kept on two different diets; carrots, a high calcium diet (41 mg/ 100 kg) or potatoes, a low calcium diet (14 mg/ 100g). 3. The results show that the urine of the mole rat contained high values of calcium bicarbonate on either diet. 4. The urine of the vlei rat showed high values of calcium bicarbonate only when kept on the high calcium diet. 5. From these results we assume that in subterranean rodents excretion of calcium bicarbonate is an adaptive mechanism to unload CO2 without increasing its concentration in the hypercapnic environment. PMID:14575039

Haim, A; Fairall, N; Prinsloo, P W

1985-01-01

296

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2013 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1160 Bicarbonate/carbon dioxide test system. (a)...

2013-04-01

297

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

298

Physiological Sensing of Carbon Dioxide/Bicarbonate/pH via Cyclic Nucleotide Signaling  

PubMed Central

Carbon dioxide (CO2) is produced by living organisms as a byproduct of metabolism. In physiological systems, CO2 is unequivocally linked with bicarbonate (HCO3?) and pH via a ubiquitous family of carbonic anhydrases, and numerous biological processes are dependent upon a mechanism for sensing the level of CO2, HCO3, and/or pH. The discovery that soluble adenylyl cyclase (sAC) is directly regulated by bicarbonate provided a link between CO2/HCO3/pH chemosensing and signaling via the widely used second messenger cyclic AMP. This review summarizes the evidence that bicarbonate-regulated sAC, and additional, subsequently identified bicarbonate-regulate nucleotidyl cyclases, function as evolutionarily conserved CO2/HCO3/pH chemosensors in a wide variety of physiological systems.

Buck, Jochen; Levin, Lonny R.

2011-01-01

299

Mixed Micellization of Anionic Ammonium Dodecyl Sulfate and Cationic Octadecyl Trimethyl Ammonium Chloride  

Microsoft Academic Search

In aqueous mixtures of cationic OTAC (octadecyl trimethyl ammonium chloride) and anionic ADS (ammonium dodecyl sulfate) surfactants, mixed micelles were formed at low (< 0.2 wt %) total surfactant concentrations. For these mixtures mixed micellization and interaction of surfactant molecules were examined. Mixed critical micelle concentration (CMC), thermodynamic potentials of micellization, and minimum area per surfactant molecule at the interface

Kye-Hong Kang; Hong-Un Kim; Kyung-Hee Lim; Noh-Hee Jeong

300

Method for flue gas conditioning with the decomposition products of ammonium sulfate or ammonium bisulfate  

Microsoft Academic Search

This patent describes a method for conditioning flue gas containing suspended fly ash. It comprises: diverting a slipstream of flue gas from a main flue gas stream at a point upstream from an air preheater located directly upstream of an electrostatic precipitator; introducing an aqueous solution of ammonium sulfate or ammonium bisulfate into the diverted flue gas slipstream thereby effecting

R. F. Altman; J. P. Gooch; E. B. Dismukes; E. C. Jr. Landham

1989-01-01

301

Application of anaerobic ammonium-oxidizing consortium to achieve completely autotrophic ammonium and sulfate removal  

Microsoft Academic Search

The simultaneous ammonium and sulfate removal was detected in an anammox reactor, consisted of ammonium oxidization with sulfate deoxidization, and subsequently traditional anammox process, in via of middle medium nitrite with solid sulfur and N2 as the terminal products. The pure anammox bacteria offered a great biotechnological potential for the completely autotrophic reaction indicated by batch tests. Denaturing gradient gel

Sitong Liu; Fenglin Yang; Zheng Gong; Fangang Meng; Huihui Chen; Yuan Xue; Kenji Furukawa

2008-01-01

302

A Mathematical Model of the Pancreatic Duct Cell Generating High Bicarbonate Concentrations in Pancreatic Juice  

Microsoft Academic Search

Objective: To develop a simple, physiologically based mathemati- cal model of pancreatic duct cell secretion using experimentally de- rived parameters that generates pancreatic fluid bicarbonate concen- trations of >140 mM after CFTR activation. Methods: A new mathematical model was developed simulating a duct cell within a proximal pancreatic duct and included a sodium-2- bicarbonate cotransporter (NBC) and sodium-potassium pump (NaK

David C. Whitcomb; G. Bard Ermentrout

2004-01-01

303

In vitro antifungal effects of potassium bicarbonate on Trichoderma sp. and Sclerotinia sclerotiorum  

Microsoft Academic Search

Bicarbonates are often utilized in the food industry to avoid fermentation and to improve pH, flavor, and texture. In the\\u000a same manner, bicarbonates have been demonstrated to control postharvest phytopathogens; however, there are no reports describing\\u000a the effects of these chemical compounds either on soil-borne pathogens such as Sclerotinia sclerotiorum or on antagonist fungi such as Trichoderma species. This study

Claudia Ordóñez-Valencia; Alejandro Alarcón; Ronald Ferrera-Cerrato; Laura Verónica Hernández-Cuevas

2009-01-01

304

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

305

Effect of Sodium Bicarbonate Administration on Mortality in Patients with Lactic Acidosis: A Retrospective Analysis  

PubMed Central

Background Lactic acidosis is a common cause of high anion gap metabolic acidosis. Sodium bicarbonate may be considered for an arterial pH <7.15 but paradoxically depresses cardiac performance and exacerbates acidosis by enhancing lactate production. This study aimed to evaluate the cause and mortality rate of lactic acidosis and to investigate the effect of factors, including sodium bicarbonate use, on death. Methods We conducted a single center analysis from May 2011 through April 2012. We retrospectively analyzed 103 patients with lactic acidosis among 207 patients with metabolic acidosis. We used SOFA and APACHE II as severity scores to estimate illness severity. Multivariate logistic regression analysis and Cox regression analysis models were used to identify factors that affect mortality. Results Of the 103 patients with a mean age of 66.1±11.4 years, eighty-three patients (80.6%) died from sepsis (61.4%), hepatic failure, cardiogenic shock and other causes. The percentage of sodium bicarbonate administration (p?=?0.006), catecholamine use, ventilator care and male gender were higher in the non-survival group than the survival group. The non-survival group had significantly higher initial and follow-up lactic acid levels, lower initial albumin, higher SOFA scores and APACHE II scores than the survival group. The mortality rate was significantly higher in patients who received sodium bicarbonate. Sodium bicarbonate administration (p?=?0.016) was associated with higher mortality. Independent factors that affected mortality were SOFA score (Exp (B)?=?1.72, 95% CI?=?1.12–2.63, p?=?0.013) and sodium bicarbonate administration (Exp (B)?=?6.27, 95% CI?=?1.10–35.78, p?=?0.039). Conclusions Lactic acidosis, which has a high mortality rate, should be evaluated in patients with metabolic acidosis. In addition, sodium bicarbonate should be prescribed with caution in the case of lactic acidosis because sodium bicarbonate administration may affect mortality.

Kim, Hyun Jeong; Son, Young Ki; An, Won Suk

2013-01-01

306

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

307

Efficient degradation of organic pollutants in aqueous solution with bicarbonate-activated hydrogen peroxide  

Microsoft Academic Search

Bicarbonate anion is an efficient activator for hydrogen peroxide to generate many active oxygen species including peroxymonocarbonate (HCO4-), superoxide ion (O2-) and singlet oxygen (1O2). This study aims to understand the oxidative degradation of organic pollutants including methyl blue, methyl orange, rhodamine B, and 4-chlorophenol, with H2O2 activated by sodium bicarbonate at room temperature. The obtained results indicate that such

Aihua Xu; Xiaoxia Li; Hui Xiong; Guochuan Yin

2011-01-01

308

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

309

Cellular bicarbonate protects rat duodenal mucosa from acid-induced injury  

PubMed Central

Secretion of bicarbonate from epithelial cells is considered to be the primary mechanism by which the duodenal mucosa is protected from acid-related injury. Against this view is the finding that patients with cystic fibrosis, who have impaired duodenal bicarbonate secretion, are paradoxically protected from developing duodenal ulcers. Therefore, we hypothesized that epithelial cell intracellular pH regulation, rather than secreted extracellular bicarbonate, was the principal means by which duodenal epithelial cells are protected from acidification and injury. Using a novel in vivo microscopic method, we have measured bicarbonate secretion and epithelial cell intracellular pH (pHi), and we have followed cell injury in the presence of the anion transport inhibitor DIDS and the Cl– channel inhibitor, 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB). DIDS and NPPB abolished the increase of duodenal bicarbonate secretion following luminal acid perfusion. DIDS decreased basal pHi, whereas NPPB increased pHi; DIDS further decreased pHi during acid challenge and abolished the pHi overshoot over baseline observed after acid challenge, whereas NPPB attenuated the fall of pHi and exaggerated the overshoot. Finally, acid-induced epithelial injury was enhanced by DIDS and decreased by NPPB. The results support the role of intracellular bicarbonate in the protection of duodenal epithelial cells from luminal gastric acid.

Akiba, Yasutada; Furukawa, Osamu; Guth, Paul H.; Engel, Eli; Nastaskin, Igor; Sassani, Pejvak; Dukkipatis, Ramanath; Pushkin, Alexander; Kurtz, Ira; Kaunitz, Jonathan D.

2001-01-01

310

Internephron heterogeneity for carbonic anhydrase-independent bicarbonate reabsorption in the rat.  

PubMed Central

The present experiments were designed to localize the sites of carbonic anhydrase-independent bicarbonate reabsorption in the rat kidney and to examine some of its mechanisms. Young Munich-Wistar rats were studied using standard cortical and papillary free-flow micropuncture techniques. Total CO2 (tCO2) was determined using microcalorimetry. In control rats both superficial and juxtamedullary proximal nephrons reabsorbed approximately 95% of the filtered load of bicarbonate. The administration of acetazolamide (20 mg/kg body weight [bw]/h) decreased proximal reabsorption to 65.6% of the filtered load in superficial nephrons (32% was reabsorbed by the proximal convoluted tubule while 31.7% was reabsorbed by the loop segment), and to 38.4% in juxtamedullary nephrons. Absolute reabsorption of bicarbonate was also significantly higher in superficial than in juxtamedullary nephrons after administration of acetazolamide (727 +/- 82 vs. 346 +/- 126 pmol/min; P less than 0.05). The infusion of amiloride (2.5 mg/kg bw/h) to acetazolamide-treated rats increased the fractional excretion of bicarbonate as compared with animals treated with acetazolamide alone (34.9 +/- 1.9 vs. 42.9 +/- 2.1%; P less than 0.01), and induced net addition of bicarbonate between the superficial early distal tubule and the final urine (34.8 +/- 3.0 vs. 42.9 +/- 2.1%; P less than 0.05). Amiloride at this dose did not affect proximal water or bicarbonate transport; our studies localize its site of action to the terminal nephron. Vasa recta (VR) plasma and loop of Henle (LH) tubular fluid tCO2 were determined in control and acetazolamide-treated rats in order to identify possible driving forces for carbonic anhydrase-independent bicarbonate reabsorption in the rat papilla. Control animals showed a tCO2 gradient favoring secretion (LH tCO2, 7.4 +/- 1.7 mM vs. VR tCO2, 19.1 +/- 2.3 mM; P less than 0.005). Acetazolamide administration reversed this chemical concentration gradient, inducing a driving force favoring reabsorption of bicarbonate (LH tCO2, 27.0 +/- 1.4 mM vs. VR tCO2, 20.4 +/- 1.0 mM; P less than 0.005). Our study shows that in addition to the superficial proximal convoluted tubule, the loop segment and the collecting duct show acetazolamide-insensitive bicarbonate reabsorption. No internephron heterogeneity for bicarbonate transport was found in controls. The infusion of acetazolamide, however, induced significant internephron heterogeneity for bicarbonate reabsorption, with superficial nephrons reabsorbing a higher fractional and absolute load of bicarbonate than juxtamedullary nephrons. We think that the net addition of bicarbonate induced by amiloride is secondary to inhibition of voltage-dependent, carbonic anhydrase-independent bicarbonate reabsorption at the level of the collecting duct, which uncovers a greater delivery of carbonate from deeper nephrons to the collecting duct. Finally, our results suggest that carbonic anhydrase-independent bicarbonate reabsorption is partly passive, driven by favorable chemical gradients in the papillary tubular structures, and partly voltage-dependent, in the collecting duct.

Frommer, J P; Laski, M E; Wesson, D E; Kurtzman, N A

1984-01-01

311

Buffer Asymptotics for Coding Over Networks  

Microsoft Academic Search

Traditionally, network buffer resources have been used at routers to queue transient packets to prevent packet drops. In contrast, we propose a scheme for large multihop networks where intermediate routers have no buffers for queueing transient packets. In the proposed scheme, network storage resources (memory) are used only at source and destination nodes to encode\\/decode packets using random linear coding

Sandeep Bhadra; Sanjay Shakkottai

2010-01-01

312

Box Calculus with High-Level Buffers  

Microsoft Academic Search

In this paper, we propose a high-level process algebra al- lowing to express the exchange of data values using both handshake and buffered communication. This allows a sim- ple and compositional expression of interprocess communi- cation; in particular the buffered one makes easy the repre- sentation of program variables, allowing a compact repre- sentation of large systems. The process terms

Cécile Bui Thanh; Hanna Klaudel; Franck Pommereau

313

Scheduling in switches with small internal buffers  

Microsoft Academic Search

Unbuffered crossbars or switching fabrics contain no internal buffers, and function using only input (VOQ) and possibly output queues. Schedulers for such switches are complex, and introduce increased delay at medium loads, because they have to admit at most one cell per input and per output, during each time slot. Buffered crossbars, on the other hand, contain Q sufficient internal

Nikos Chrysos; Manolis Katevenis

2005-01-01

314

Reducing State Changes with a Pipeline Buffer  

Microsoft Academic Search

A limiting factor in the performance of a render- ing system is the number of state changes, i.e., changes of the attributes material, texture, shader program, etc., in the stream of rendered primitives. We propose to include a small buffer between appli- cation and graphics hardware in the rendering sys- tem. This pipeline buffer is used to rearrange the incoming

Jens Krokowski; Harald Räcke; Christian Sohler; Matthias Westermann

2004-01-01

315

African American College Women's Suicide Buffers.  

ERIC Educational Resources Information Center

|To examine the relationships buffers may have with suicide ideation, 300 African American female college students completed measures of suicide ideation and buffers. Three variables accounted for a significant and unique portion of the variance in suicide ideation: family support, a view that suicide is unacceptable, and a collaborative religious…

Marion, Michelle S.; Range, Lillian M.

2003-01-01

316

African American College Women's Suicide Buffers.  

ERIC Educational Resources Information Center

To examine the relationships buffers may have with suicide ideation, 300 African American female college students completed measures of suicide ideation and buffers. Three variables accounted for a significant and unique portion of the variance in suicide ideation: family support, a view that suicide is unacceptable, and a collaborative religious…

Marion, Michelle S.; Range, Lillian M.

2003-01-01

317

Modeling buffer layer IGBTs for circuit simulation  

Microsoft Academic Search

The dynamic behavior of commercially available buffer layer IGBTs is described. It is shown that buffer layer IGBTs become much faster at high voltages than nonbuffer layer IGBTs with similar low voltage characteristics. Because the fall times specified in manufacturers' data sheets do not reflect the voltage dependence of switching speed, a new method of selecting devices for different circuit

1995-01-01

318

Buffer insertion for noise and delay optimization  

Microsoft Academic Search

Buffer insertion has successfully been applied to reduce delay in global interconnect paths; however, existing techniques only optimize delay and timing slack. With the increasing ratio of coupling to total capacitance and the use of aggressive dynamic logic circuit families, noise is becoming a major design bottleneck. We present comprehensive buffer insertion techniques for noise and delay optimization. Our experiments

Charles J. Alpert; Anirudh Devgan; Stephen T. Quay

1998-01-01

319

46 CFR 58.25-45 - Buffers.  

Code of Federal Regulations, 2010 CFR

... Shipping 2 2009-10-01 2009-10-01 false Buffers. 58.25-45 Section 58.25-45 Shipping COAST...MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-45 Buffers. For each vessel on an ocean, coastwise, or Great...

2009-10-01

320

46 CFR 58.25-45 - Buffers.  

Code of Federal Regulations, 2010 CFR

... Shipping 2 2010-10-01 2010-10-01 false Buffers. 58.25-45 Section 58.25-45 Shipping COAST...MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-45 Buffers. For each vessel on an ocean, coastwise, or Great...

2010-10-01

321

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

322

Buffer Management in a Packet Switch  

Microsoft Academic Search

Consider a single packet switch with a finite number of packet buffers shared between several output queues. An arriving packet is lost if no free buffer is available, as in the CIGALE network. It has been observed by simulation that if load increases too much, congestion may occur, i.e., throughput declines; it appears that the busiest link's queue tends to

MAREK I. IRLAND

1978-01-01

323

AUTOMATIC TRANSFER LINES WITH BUFFER STOCKS  

Microsoft Academic Search

The efficiency of an automatic transfer line can be increased by dividing the line into a number of stages and providing buffer stores between the stages.The results of a theoretical study of the effect of buffer stocks on automatic fixed cycle in line transfer machines are reported. It is shown how the improvement in efficiency depends on the number of

J. A. BUZACOTT

1967-01-01

324

Statically Detecting Likely Buffer Overflow Vulnerabilities  

Microsoft Academic Search

Buffer overflow attacks may be today's single most important security threat. This paper presents a new approach to mitigating buffer overflow vulnerabilities by detecting likely vulnerabilities through an analysis of the program source code. Our approach exploits information provided in semantic comments and uses lightweight and efficient static analyses. This paper describes an implementation of our approach that extends the

David Larochelle; David Evans

2001-01-01

325

Water Resource Protection by Riparian Buffer Zones  

Microsoft Academic Search

Growing switch-grass in a riparian buffer zone can be one of future best management practices in water resource protection. Switch-grass requires no fertilizers and less land and water. It was recently found to be a good source of biomass. In this study, Soil and Water Assessment Tool (SWAT) model was applied to a watershed to examine the effectiveness of buffer

Roy R. Gu; Mahesh K. Sahu

2010-01-01

326

Metal buffer layer inserted switchable mirrors  

Microsoft Academic Search

Thin buffer layers of hydrogen diffusive metals such as Ti, Nb, and V were inserted between a Mg4Ni thin film and a Pd top layer, which were prepared by DC magnetron sputtering. Their optical, electrochemical properties, and switching durability were investigated using both gasochromic and electrochromic switching methods. It has been proved that Ti, Nb, and V buffer layers can

S. Bao; K. Tajima; Y. Yamada; M. Okada; K. Yoshimura

2008-01-01

327

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.

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

328

Inhibition of shoot geotropism by neutral buffers.  

PubMed

Submerged hypocotyl sections from Helianthus have been used to test the effect of neutral buffers on shoot geotropism. When hypocotyls have been abraded, it is found that increasing the molarity (0.25 to 20 mm) of pH 6.8 K-phosphate buffer, as well as other buffering systems, results in a strong inhibition of geotropic curvature. Buffer strength has no such effect on the curvature of nonabraded segments. One possible explanation for these data is that asymmetric shoot growth following geostimulation may require the establishment of a proton gradient across the cell walls of the shoot. When neutral buffers have access to the wall space (i.e. in abraded segments), they may prevent the establishment of such a gradient. PMID:16662175

Wright, L Z; Rayle, D L

1982-01-01

329

Blood buffer values in mineral deficiency  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a The buffer values of serum obtained from normal and rachitic infants have been determined electrometrically for the entire\\u000a pH range.\\u000a \\u000a \\u000a \\u000a 2. \\u000a The blood buffer curves of normal and rachitic infants plotted against that of a non-buffered solution show the marked diminution\\u000a in the blood buffer capacity in rickets.\\u000a \\u000a \\u000a \\u000a 3. \\u000a The buffer action of blood is not constant but

I. Newton Kugelmass

1935-01-01

330

Optimization of protein buffer cocktails using Thermofluor.  

PubMed

The stability and homogeneity of a protein sample is strongly influenced by the composition of the buffer that the protein is in. A quick and easy approach to identify a buffer composition which increases the stability and possibly the conformational homogeneity of a protein sample is the fluorescence-based thermal-shift assay (Thermofluor). Here, a novel 96-condition screen for Thermofluor experiments is presented which consists of buffer and additive parts. The buffer screen comprises 23 different buffers and the additive screen includes small-molecule additives such as salts and nucleotide analogues. The utilization of small-molecule components which increase the thermal stability of a protein sample frequently results in a protein preparation of higher quality and quantity and ultimately also increases the chances of the protein crystallizing. PMID:23385769

Reinhard, Linda; Mayerhofer, Hubert; Geerlof, Arie; Mueller-Dieckmann, Jochen; Weiss, Manfred S

2013-01-31

331

Bacterial metabolism of quaternary ammonium compounds.  

PubMed Central

Of 10 quaternary ammonium compounds tested for biodegradation by the biological oxygen demand technique, only decyl- and hexadecyltrimethylammonium bromides were decomposed by organisms derived from sewage and soil. A mixture consisting of individual strains of Pseudomonas and Xanthomonas grew in solutions containing decyltrimethylammonium bromide as sole carbon source. The xanthomonad metabolized this quaternary ammonium compound in the presence of other organic molecules. The products of this activity included 9-carboxynomyl- and 7-carboxyheptyltrimethylammonium, suggesting that the terminal carbon of the decyl moiety is oxidized and the resulting carboxylic acid is subject to beta-oxidation.

Dean-Raymond, D; Alexander, M

1977-01-01

332

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

333

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.

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

2009-01-01

334

Molecular doping of graphene with ammonium groups  

SciTech Connect

Successful doping of an electronic material entails the existence of stable dopant configurations that cause a shift in the Fermi level without altering significantly the electronic states of the host system. The selection of chemical groups that satisfy these conditions when adsorbed on graphene is still an open challenge. Here we show with first-principles calculations that ammonium groups meet the criteria of stable physisorption and efficient doping of graphene. We also describe processes of deactivation of ammonium dopants through their dissociation over graphene impurities or nanoribbon edges. Finally, we show that carbon nanotubes can be used to spatially confine the dopants and avert their edge-related de-activation.

Tsetseris, L. [Vanderbilt University; Pantelides, Sokrates T [ORNL

2012-01-01

335

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

336

Evidence of ammonium ion-exchange properties of natural bentonite and application to ammonium detection.  

PubMed

Ammonium exchange with hybrid PVC-bentonite (mineral montmorillonite clay) thin film was revealed using FTIR spectroscopy, EDX, cyclic voltammetry and electrochemical impedance spectroscopy. The effect of ammonium exchange on the charge transfer resistance of PVC-bentonite hybrid thin film was attributed to a modification of the intersheet distance and hydration of bentonite crystals. The obtained impedimetric ammonium sensor shows a linear range of detection from 10(-4)M to 1M and a detection limit around 10(-6)M. PMID:24094228

Zazoua, A; Kazane, I; Khedimallah, N; Dernane, C; Errachid, A; Jaffrezic-Renault, N

2013-09-15

337

Ability of sat-1 to transport sulfate, bicarbonate, or oxalate under physiological conditions.  

PubMed

Tubular reabsorption of sulfate is achieved by the sodium-dependent sulfate transporter, NaSi-1, located at the apical membrane, and the sulfate-anion exchanger, sat-1, located at the basolateral membrane. To delineate the physiological role of rat sat-1, [(35)S]sulfate and [(14)C]oxalate uptake into sat-1-expressing oocytes was determined under various experimental conditions. Influx of [(35)S]sulfate was inhibited by bicarbonate, thiosulfate, sulfite, and oxalate, but not by sulfamate and sulfide, in a competitive manner with K(i) values of 2.7 +/- 1.3 mM, 101.7 +/- 9.7 microM, 53.8 +/- 10.9 microM, and 63.5 +/- 38.7 microM, respectively. Vice versa, [(14)C]oxalate uptake was inhibited by sulfate with a K(i) of 85.9 +/- 9.5 microM. The competitive type of inhibition indicates that these compounds are most likely substrates of sat-1. Physiological plasma bicarbonate concentrations (25 mM) reduced sulfate and oxalate uptake by more than 75%. Simultaneous application of sulfate, bicarbonate, and oxalate abolished sulfate as well as oxalate uptake. These data and electrophysiological studies using a two-electrode voltage-clamp device provide evidence that sat-1 preferentially works as an electroneutral sulfate-bicarbonate or oxalate-bicarbonate exchanger. In kidney proximal tubule cells, sat-1 likely completes sulfate reabsorption from the ultrafiltrate across the basolateral membrane in exchange for bicarbonate. In hepatocytes, oxalate extrusion is most probably mediated either by an exchange for sulfate or bicarbonate. PMID:19369292

Krick, Wolfgang; Schnedler, Nina; Burckhardt, Gerhard; Burckhardt, Birgitta C

2009-04-15

338

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

339

Measuring equilibrium bicarbonate concentrations directly in cellular mitochondria and in human serum using europium/terbium emission intensity ratios.  

PubMed

A series of Eu and Tb complexes of four different chiral ligands incorporating an azaxanthone sensitiser has been evaluated as probes for the bicarbonate anion. Their binding affinities were assessed at ambient pH with bicarbonate, lactate, citrate, phosphate and serum albumin. Binding was signalled by modulation of circularly polarised luminescence and apparent affinity constants were measured by examining changes in emission intensity ratios. Competition experiments show that with these species and ATP present at normal physiological values, bicarbonate can be determined selectively over the concentration range 10 to 35?mM. Bicarbonate levels are also reported by using a mixture of Eu and Tb complexes of a common ligand, examining the ratio of red/green emitted light. These methods have been adapted for the determination of bicarbonate in human serum and used for the assessment of mitochondrial levels of bicarbonate in several different cell types with confocal microscopy. PMID:22865800

Smith, David G; Pal, Robert; Parker, David

2012-08-02

340

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

341

40 CFR 418.60 - Applicability; description of the ammonium sulfate production subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the ammonium sulfate production subcategory. 418...MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production Subcategory § 418...Applicability; description of the ammonium sulfate production subcategory....

2010-07-01

342

40 CFR 418.60 - Applicability; description of the ammonium sulfate production subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the ammonium sulfate production subcategory. 418...MANUFACTURING POINT SOURCE CATEGORY Ammonium Sulfate Production Subcategory § 418...Applicability; description of the ammonium sulfate production subcategory....

2009-07-01

343

AMMONIUM DIURANATE PRECIPITATION WITH ANHYDROUS AMMONIA  

Microsoft Academic Search

Ammonium diuranate has been precipitated from nitric acid solutions by ; the addition of anhydrpus ammonia on both laboratory and production scales. This ; process produced more dense and morc rapidly filtered precipitates than those ; formed by the addition of aqueous amonia or slurried calcium hydroxide. Thc ; filtrates from the anhydrous ammonia process were lower in uranium content

L. C. Farrell; L. F. Grill

1959-01-01

344

Tunicate Eggs Utilize Ammonium Ions for Flotation  

Microsoft Academic Search

Unlike most solitary ascidians, Corella willmeriana retains its eggs and embryos well past hatching. The early stages float to the top of the enlarged atrium from which they cannot escape. Ammonium ions replace other more dense substances in the cell sap of the float cells surrounding the embryo. Energy derived from glycolysis but not mitochondrial processes supports this process.

Charles C. Lambert; Gretchen Lambert

1978-01-01

345

Ammonium ions determination with polypyrrole modified electrode  

Microsoft Academic Search

The present work relates the preparation of polypyrrole films (PPy) deposited on surfaces of glass carbon, nickel and ITO (tin oxide doped with indium) on PET plastic, in order to study the ammonium detection. The popypyrrole films were polymerized with dodecylbenzenesulfonate (DBSA) on the electrodes, at + 0,70 V vs. Ag\\/AgCl, based on a solution containing the pyrrole monomer and

Luciana T. S. Mendes; Luiz Henrique DallAntonia

346

Anticaking and antidusting composition for ammonium nitrate  

Microsoft Academic Search

An aqueous liquid anticaking and antidusting composition is described comprising, from 20 to 30 parts of a sodium naphthalene sulfonate, from 17 to 28 parts of an ammonium naphthalene sulfonate, the naphthalene of the aforesaid sulfonates being selected from naphthalene and methyl-substituted derivatives thereof, and from 30 to 80 parts of water, the composition being neutralized with acid to a

A. W. Newman; M. L. Bishop

1988-01-01

347

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 ...

348

Eliminating Cell Broadband Engine™ DMA Buffer Overflows  

NASA Astrophysics Data System (ADS)

This paper presents effective and efficient implementation techniques for DMA buffer overflow elimination on the Cell Broadband Engine™ (Cell/B.E.) processor. In the Cell/B.E. programming model, application developers manually issue DMA commands to transfer data from the system memory to the local memories of the Cell/B.E. cores. Although this allows us to eliminate cache misses or cache invalidation overhead, it requires careful management of the buffer arrays for DMA in the application programs to prevent DMA buffer overflows. To guard against DMA buffer overflows, we introduced safe DMA handling functions for the applications to use. To improve and minimize the performance overhead of buffer overflow prevention, we used three different optimization techniques that take advantage of SIMD operations: branch-hint-based optimizations, jump-table-based optimizations and self-modifying-based optimizations. Our optimized implementation prevents all DMA buffer overflows with minimal performance overhead, only 2.93% average slowdown in comparison to code without the buffer overflow protection.

Murase, Masana

349

Buffer-regulated biocorrosion of pure magnesium.  

PubMed

Magnesium (Mg) alloys are being actively investigated as potential load-bearing orthopaedic implant materials due to their biodegradability in vivo. With Mg biomaterials at an early stage in their development, the screening of alloy compositions for their biodegradation rate, and hence biocompatibility, is reliant on cost-effective in vitro methods. The use of a buffer to control pH during in vitro biodegradation is recognised as critically important as this seeks to mimic pH control as it occurs naturally in vivo. The two different types of in vitro buffer system available are based on either (i) zwitterionic organic compounds or (ii) carbonate buffers within a partial-CO(2) atmosphere. This study investigated the influence of the buffering system itself on the in vitro corrosion of Mg. It was found that the less realistic zwitterion-based buffer did not form the same corrosion layers as the carbonate buffer, and was potentially affecting the behaviour of the hydrated oxide layer that forms on Mg in all aqueous environments. Consequently it was recommended that Mg in vitro experiments use the more biorealistic carbonate buffering system when possible. PMID:22190196

Kirkland, Nicholas T; Waterman, Jay; Birbilis, Nick; Dias, George; Woodfield, Tim B F; Hartshorn, Richard M; Staiger, Mark P

2011-12-22

350

A New Fast Slew Buffering Algorithm Without Input Slew Assumptions  

Microsoft Academic Search

As VLSI technology moves to the nanoscale regime, an ultra-fast slew buffering technique to buffer large number of nets and minimize buffering cost is highly desirable. The existing method proposed in [1] is able to efficiently perform buffer insertion with a simplified assumption on buffer input slew, however, when handling more general cases without input slew assumptions, it becomes slow

Shiyan Hu; Jiang Hu

2007-01-01

351

Sodium bicarbonate supplementation improves hypertrophy-type resistance exercise performance.  

PubMed

The aim of the present study was to examine the effects of sodium bicarbonate (NaHCO(3)) administration on lower-body, hypertrophy-type resistance exercise (HRE). Using a double-blind randomized counterbalanced design, 12 resistance-trained male participants (mean ± SD; age = 20.3 ± 2 years, mass = 88.3 ± 13.2 kg, height = 1.80 ± 0.07 m) ingested 0.3 g kg(-1) of NaHCO(3) or placebo 60 min before initiation of an HRE regimen. The protocol employed multiple exercises: squat, leg press, and knee extension, utilizing four sets each, with 10-12 repetition-maximum loads and short rest periods between sets. Exercise performance was determined by total repetitions generated during each exercise, total accumulated repetitions, and a performance test involving a fifth set of knee extensions to failure. Arterialized capillary blood was collected via fingertip puncture at four time points and analyzed for pH, [HCO(3)(-)], base excess (BE), and lactate [Lac(-)]. NaHCO(3) supplementation induced a significant alkaline state (pH: NaHCO(3): 7.49 ± 0.02, placebo: 7.42 ± 0.02, P < 0.05; [HCO(3)(-)]: NaHCO(3): 31.50 ± 2.59, placebo: 25.38 ± 1.78 mEq L(-1), P < 0.05; BE: NaHCO(3): 7.92 ± 2.57, placebo: 1.08 ± 2.11 mEq L(-1), P < 0.05). NaHCO(3) administration resulted in significantly more total repetitions than placebo (NaHCO(3): 139.8 ± 13.2, placebo: 134.4 ± 13.5), as well as significantly greater blood [Lac(-)] after the exercise protocol (NaHCO(3): 17.92 ± 2.08, placebo: 15.55 ± 2.50 mM, P < 0.05). These findings demonstrate ergogenic efficacy for NaHCO(3) during HRE and warrant further investigation into chronic training applications. PMID:22941193

Carr, Benjamin M; Webster, Michael J; Boyd, Joseph C; Hudson, Geoffrey M; Scheett, Timothy P

2012-09-04

352

Chloride and bicarbonate transport in fetal red cells.  

PubMed Central

1. Chloride (JCl) and bicarbonate (JHCO3) self-exchange flux in fetal human red cells was studied at 0-38 degrees C as 36Cl- and [14C]HCO3- efflux. 2. Both at 0 and 38 degrees C JCl showed a bell-shaped pH dependence with a broad maximum at pH 7-8. JCl was 99.7% inhibited by the binding of 1.1 x 10(6) 4,4'-diisothiocyanostilbene-2,2'-disulphonate (DIDS) molecules per cell membrane. 3. By raising the temperature from 0 to 38 degrees C JCl, at external concentration (C0) = 150 mM, increased about 200 times to 5 x 10(-8) mol/(cm2 s), the half-time of the tracer efflux being 80 ms at 38 degrees C and pH 7.2. Under conditions where Co = (110 mM-Cl- + 25 mM-HCO3-), JCl also increased by about 200 times, while JHCO3 increased only about 100 times, as temperature was raised from 0 to 38 degrees C. 4. The apparent activation energy (EA) of Janion was not constant, but increased gradually with decreasing temperature. Assuming that the change of EA with temperature consists of two components JCl, under both experimental conditions, had average values of EA = 117-120 under and EA = 73-78 kJ/mol above a 'breaking' point at 15-20 degrees C, while JHCO3 showed an EA = 100 below and EA = 48 kJ/mol above 25 degrees C. 5. We conclude that the anion transport protein becomes built into the membrane at a very early stage of life, and that the kinetics of Janion in fetal red cells show characteristics that are similar to those of adult red cells. 6. Our results suggest that the CO2 transport capacity of the fetal blood can be exploited during rest nearly as efficiently as that of adult blood.

Brahm, J; Wimberley, P D

1989-01-01

353

Borate buffer equilibria in nickel refining electrolytes  

Microsoft Academic Search

Buffer capacity studies, carried out using pH titrations, demonstrated that electrolytes containing NiSO4 + H3BO3 + Na2SO4 buffer more effectively than in the presence of H3BO3 + Na2SO4. The increased buffer capacity is dependent on the concentration of both Ni2+ and H3BO3. Thermodynamic analysis of the pH titration data suggested the formation of a weak complex, Ni(H2BO3)2, (logK ~ 3.8

B. V. Tilak; A. S. GENDRONt; M. A. Mosoiu

1977-01-01

354

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

2007-10-22

355

40 CFR 721.6070 - Alkyl phosphonate ammonium salts.  

Code of Federal Regulations, 2010 CFR

... false Alkyl phosphonate ammonium salts. 721.6070 Section 721.6070 Protection of Environment ENVIRONMENTAL PROTECTION...New Uses for Specific Chemical Substances § 721.6070 Alkyl phosphonate ammonium salts. (a)...

2010-07-01

356

40 CFR 721.6070 - Alkyl phosphonate ammonium salts.  

Code of Federal Regulations, 2010 CFR

... false Alkyl phosphonate ammonium salts. 721.6070 Section 721.6070 Protection of Environment ENVIRONMENTAL PROTECTION...New Uses for Specific Chemical Substances § 721.6070 Alkyl phosphonate ammonium salts. (a)...

2009-07-01

357

21 CFR 73.1298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Ferric ammonium ferrocyanide. 73.1298 Section 73.1298 Food and Drugs FOOD AND DRUG ADMINISTRATION...ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1298 Ferric ammonium ferrocyanide. (a)...

2010-04-01

358

21 CFR 73.1298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Ferric ammonium ferrocyanide. 73.1298 Section 73.1298 Food and Drugs FOOD AND DRUG ADMINISTRATION...ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1298 Ferric ammonium ferrocyanide. (a)...

2009-04-01

359

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

360

Effects of sodium bicarbonate dentifrices on the levels of cariogenic bacteria in human saliva.  

PubMed

This investigation evaluated the efficacy of two bicarbonate-containing dentifrices (one with fluoride and one without) against one placebo dentifrice (containing neither fluoride nor bicarbonate) in vivo in a panel of human volunteers to determine whether or not sodium bicarbonate would affect salivary mutans streptococci and lactobacilli. Ten caries-inactive adults were divided randomly into three groups, each of which was exposed to all three dentifrices, in a crossover manner, during three 4-week test periods. Saliva samples were taken at 1-week intervals. Samples were stored on ice, and microbiological analyses were conducted. The statistical analyses showed that, over a 4-week period, there was a statistically significant (p < 0.05) reduction in numbers of mutans streptococci with the two bicarbonate dentifrices as compared with the placebo dentifrice. Although not statistically significant, a similar trend was observed with lactobacilli. Longer-term, large-scale studies need to be conducted to investigate the possible mechanisms of action of sodium bicarbonate on these organisms and to relate the results to possible cariostatic effects in humans. PMID:7728829

Legier-Vargas, K; Mundorff-Shrestha, S A; Featherstone, J D; Gwinner, L M

1995-01-01

361

Technology for processing ammonium rhodanide of coking plants into high-purity ammonium thiocyanate and thiourea  

SciTech Connect

The regularities of the reversible reaction of isomerization of ammonium thiocyanate (NH{sub 4}NCS) into thiourea (NH{sub 2}){sub 2}CS, and the reverse reaction, were analyzed. An ecologically clean and highly efficient method for the extraction, purification, separation, and production of isomers from the coal byproduct ammonium thiocyanate was developed based on the measured volatilities of NH{sub 4}NCS and (NH{sub 2}){sub 2}CS.

Urakaev, F.K. [Institute of Geology & Mineral SB RAS, Novosibirsk (Russian Federation)

2009-04-15

362

Ammonium tris-(tetra-ethyl-ammonium) hexa-cosa-oxidoocta-molybdate  

PubMed Central

The structure of the title compound, NH4(C8H20N)3[Mo8O26], is built up by discrete cations and anions, with two formula units in the asymmetric unit. The ?-octa­molybdate anions are linked to the ammonium cations via N—H?O hydrogen bonding involving terminal oxide groups and to the tetra­ethyl­ammonium cations via weak C—H?O inter­actions.

Zebiri, Ikram; Bencharif, Leila; Direm, Amani; Bencharif, Mustapha; Benali-Cherif, Nourredine

2008-01-01

363

Automatic initialisation of buffer composition estimation for on-line analysis of unknown buffer solutions.  

PubMed

An automatic initialisation procedure for extracting useful information about buffer composition from a titration experiment is presented in this paper. The initialisation procedure identifies which buffering components are present in the sample from a relatively long list of buffers expected in the system monitored. The procedure determines approximate pKa values of the buffers and evaluates their maximum and minimum concentrations. This information is then used to start an optimisation procedure to fit the model of the buffer components to the titration data and to accurately determine buffer concentrations and pKa values. The procedure has been integrated as a software layer around the buffer capacity optimum model builder (BOMB) that fits a buffer-capacity model to a measured buffer-capacity curve to estimate model properties (pKa values and concentrations). The reliability and robustness of the resulting buffer capacity software (BCS) were tested using a titrimetric analyser simulator (TAS). The BCS was then validated off-line and on-line. PMID:16184364

Zaher, Usama E; Vanrolleghem, Peter A

2005-10-19

364

A Microprocessor ASCII Character Buffering System.  

National Technical Information Service (NTIS)

A microprocessor buffering system (MBS) was developed at the Environmental Monitoring and Support Laboratory -Cincinnati (EMSL-CI) to provide an efficient transfer for serial ASCII information between intelligent instrument systema and a Data General NOVA...

J. M. Teuschler R. A. Jollis J. E. Kopke

1982-01-01

365

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

366

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

367

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

368

Removal of ammonium from greywater using natural zeolite  

Microsoft Academic Search

This paper focuses on the effectiveness of removing ammonium ion and the theoretical aspects of adsorption including adsorption isotherm, kinetics and thermodynamics as well as desorption–regeneration studies. Results have demonstrated that natural zeolite shows good performance with up to 97% for ammonium removal depending on contact time, zeolite loading, initial ammonium concentration and pH. The adsorption kinetics is best approximated

Nurul Widiastuti; Hongwei Wu; Ha Ming Ang; Dongke Zhang

2011-01-01

369

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

370

Control of nitrification rate by increasing ammonium concentration  

Microsoft Academic Search

Lysimeter experiments with maize and incubation experiments showed that increased ammonium concentrations in soil reduced nitrification rates. A modified Lees and Quastel kinetic model was proposed for predicting the relation between initial ammonium concentration in soil and nitrification rate. A term Mi strongly dependent on initial ammonium concentration ([NH40]) was introduced into the model which took the form: dy\\/dt =

A. Shaviv

1988-01-01

371

Ammonium fixation in cultivated and afforested alluvial soil  

Microsoft Academic Search

With the increased use of ammonium fertilizers a study of the absorption, retention and release of NH 4 by soil is gaining considerable importance. An ammonium saturated soil may hold NH 4 in three different forms, the free, the exchangeable and the fixed ammonium ion. The free NH 4 can be extracted from soil by water or alchohol; the exchangeable

B. P. Ghildyal; P. N. Singh

1961-01-01

372

Sediment ammonium availability and eelgrass ( Zostera marina ) growth  

Microsoft Academic Search

The interaction of sediment ammonium (NH4+) availability and eelgrass (Zostera marina L.) growth, biomass and photosynthesis was investigated using controlled environment and in-situ manipulations of pore water ammonium concentrations. Sediment diffusers were used to create pore water diffusion gradients to fertilize and deplete ammonium levels in sediments with intact eelgrass rhizospheres. Between October, 1982 and September, 1983 controlled environment experiments

W. C. Dennison; R. C. Aller; R. S. Alberte

1987-01-01

373

Temperature buffer test – design, instrumentation and measurements  

Microsoft Academic Search

The Temperature Buffer Test, TBT, is a heated full-scale field experiment carried out jointly by ANDRA and SKB at the SKB Äspö Hard Rock Laboratory in Southeast Sweden. An existing 8m deep, 1.8m diameter KBS-3-type deposition hole located at ?420m level has been selected for the test.The objectives are to improve the general understanding of Thermo-Hydro-Mechanical, THM, behavior of buffer

Torbjörn Sandén; Reza Goudarzi; Michel de Combarieu; Mattias Åkesson; Harald Hökmark

2007-01-01

374

Baroreflex Buffering and Susceptibility to Vasoactive Drugs  

Microsoft Academic Search

Background—The overall effect of vasoactive drugs on blood pressure is determined by a combination of the direct effect on vascular tone and an indirect baroreflex-mediated effect, a baroreflex buffering of blood pressure. Differences in baroreflex function affect the responsiveness to vasoactive medications, particularly baroreflex buffering of blood pressure; however, the magnitude is not known. Methods and Results—We characterized baroreflex function

Jens Jordan; Jens Tank; John R. Shannon; Andre Diedrich; Axel Lipp; Christoph Schröder; Guy Arnold; Arya M. Sharma; Italo Biaggioni; David Robertson; Friedrich C. Luft

375

32 taps digitally controlled buffered potentiometer  

Microsoft Academic Search

The paper presents a 32-tap digitally controlled buffered potentiometer designed in a 0.8 ?m CMOS process. An up\\/down counter determines which tap is connected to the output. Output settings are stored in nonvolatile memory. A rail-to-rail op amp is used as unity-gain buffer at the output in order to eliminate the errors given by the load

C. Stanescu; A. Tache; R. Iacob

2001-01-01

376

Comments on ``A Multiaccess Frame Buffer Architecture  

Microsoft Academic Search

D.T. Harper (see ibid., vol.43, no.10, p.618-22, 1994) introduced a storage scheme in a multiaccess frame buffer scenario and showed that the proposed architecture allows parallel access to constant area rectangles of the array of pixels stored in the frame buffer. These comments show that the claim may not be true. There are cases when parallel access is not possible

Bin Wei

1996-01-01

377

Implementing Virtual Buffer for Electric Power Grids  

Microsoft Academic Search

The electric power grid is a vital network for every aspect of our life. The lack of buffer between generation and consumption\\u000a makes the power grid unstable and fragile. While large scale power storage is not technically and economically feasible at\\u000a present stage, we argue that a virtual buffer could be effectively implemented through a demand side management strategy built

Rong Gao; Lefteri H. Tsoukalas

2007-01-01

378

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 organics 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) was ? 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 organics 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.

2013-07-01

379

Infinitely selective repair buffer for EUVL reticles  

NASA Astrophysics Data System (ADS)

The three-layer absorber stack for EUVL reticles currently consists of an absorber, repair buffer and etch stop layers. The repair buffer should exhibit high etch selectivity during the absorber etch processes (i.e. pattern transfer and focused ion beam (FIB) repair), be thermally and electrically conductive, optimally thin and have high etch selectivity to the silicon-capping layer over the Mo/Si multi-layer mirror. The absorber materials that have been studied in the past are TaSiN and Cr with SiON as the repair buffer on top of a Cr etch stop layer. The SiON repair buffer is insulating, exhibiting low thermal and electrical conductivity. Also, the required thickness for FIB repair is greater than 750 Angstroms using a standard 30-keV Ga+ FIB tool, while the etch selectivity to the silicon capping layer during pattern transfer is less than five to one necessitating a Cr etch stop. A sputtered carbon repair buffer exhibiting the required qualities has been studied. The carbon film is thermally and electrically conductive and exhibits extremely high reactive ion etch selectivity to the silicon-capping layer. Carbon also has the lowest sputter yield out of all the elements opening a larger FIB repair process window without using gas-assisted etching. A conductive repair buffer also prevents the possibility of static charge buildup on the mask that could damage patterns during an electrostatic discharge.

Wasson, James R.; Smith, Ken H.; Mangat, Pawitter J.; Hector, Scott D.

2001-08-01

380

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

381

Detection and Quantification of Bacteria Involved in Aerobic and Anaerobic Ammonium Oxidation in an Ammonium-Contaminated Aquifer  

Microsoft Academic Search

The aerobic and anaerobic ammonium-oxidizing bacterial guilds were studied from two multilevel samplers in an ammonium-contaminated aquifer in the UK. By end point polymerase chain reaction (PCR), the presence of betaproteobacterial ammonium-oxidizing bacteria and anaerobic ammonium-oxidizing (anammox) planctomycetes was demonstrated. The sequences of cloned anammox-specific PCR fragments had close relationships with known anammox strains. Real-time PCR was subsequently used to

Theo H. M. Smits; Arne Hüttmann; David N. Lerner; Christof Holliger

2009-01-01

382

Population pharmacodynamic model of bicarbonate response to acetazolamide in mechanically ventilated chronic obstructive pulmonary disease patients  

PubMed Central

Introduction Acetazolamide is commonly given to chronic obstructive pulmonary disease (COPD) patients with metabolic alkalosis. Little is known of the pharmacodynamics of acetazolamide in the critically ill. We undertook the pharmacodynamic modeling of bicarbonate response to acetazolamide in COPD patients under mechanical ventilation. Methods This observational, retrospective study included 68 invasively ventilated COPD patients who received one or multiple doses of 250 or 500 mg of acetazolamide during the weaning period. Among the 68 investigated patients, 207 time-serum bicarbonate observations were available for analysis. Population pharmacodynamics was modeled using a nonlinear mixedeffect model. The main covariates of interest were baseline demographic data, Simplified Acute Physiology Score II (SAPS II) at ICU admission, cause of respiratory failure, co-prescription of drugs interfering with the acid-base equilibrium, and serum concentrations of protein, creatinin, potassium and chloride. The effect of acetazolamide on serum bicarbonate levels at different doses and in different clinical conditions was subsequently simulated in silico. Results The main covariates interacting with acetazolamide pharmacodynamics were SAPS II at ICU admission (P = 0.01), serum chloride (P < 0.001) and concomitant administration of corticosteroids (P = 0.02). Co-administration of furosemide significantly decreased bicarbonate elimination. Acetazolamide induced a decrease in serum bicarbonate with a dose-response relationship. The amount of acetazolamide inducing 50% of the putative maximum effect was 117 ± 21 mg. According to our model, an acetazolamide dosage > 500 mg twice daily is required to reduce serum bicarbonate concentrations > 5 mmol/L in the presence of high serum chloride levels or coadministration of systemic corticosteroids or furosemide. Conclusions This study identified several covariates that influenced acetazolamide pharmacodynamics and could allow a better individualization of acetazolamide dosing when treating COPD patients with metabolic alkalosis.

2011-01-01

383

Bicarbonate therapy in the treatment of septic shock: a second look.  

PubMed

The use of supplemental sodium bicarbonate for the treatment of patients with septic shock and elevated blood lactate levels remains a controversial therapy. We conducted a retrospective study between March 2004 and February 2009 of 36 consecutive patients diagnosed with septic shock who received continuous infusion of bicarbonate therapy. A control group was matched 1:1 for age, site of infection, and predicted mortality by APACHE II. All patients were managed according to standard protocols. The median time until reversal of shock did not achieve statistical significance between the bicarbonate group (44.5 h [95% confidence interval [CI] 34-54] and the control group (55.0 h [95% CI 39-60] (p = 0.09). The median time to liberation of mechanical ventilation was significantly reduced in the bicarbonate group (10 days [95% CI 5.0-13.0] compared to the control group (14 days [95% CI 9.0-19.0], p = 0.02). The length of intensive care unit (ICU) stay was also shorter in the surviving patients who received bicarbonate compared to controls (median 11.5 days (95% CI 6.0-16.0) vs. 16.0 days (95% CI 13.5-19.0), respectively; p = 0.01). However, there was no difference in 28-day mortality between the two study groups (28%; 95% CI 14-45% vs. 33%; 95% CI 19-51%, respectively; p = 0.79). Infusion of sodium bicarbonate in septic patients with arterial hyperlactatemia may facilitate weaning from mechanical ventilation and reduce length of ICU stay. PMID:20169423

El-Solh, Ali A; Abou Jaoude, Philippe; Porhomayon, Jahan

2010-02-19

384

Bicarbonate disruption of the pulmonary endothelial barrier via activation of endogenous soluble adenylyl cyclase, isoform 10.  

PubMed

It is becoming increasingly apparent that cAMP signals within the pulmonary endothelium are highly compartmentalized, and this compartmentalization is critical to maintaining endothelial barrier integrity. Studies demonstrate that the exogenous soluble bacterial toxin, ExoY, and heterologous expression of the forskolin-stimulated soluble mammalian adenylyl cyclase (AC) chimera, sACI/II, elevate cytosolic cAMP and disrupt the pulmonary microvascular endothelial barrier. The barrier-disruptive effects of cytosolic cAMP generated by exogenous soluble ACs are in contrast to the barrier-protective effects of subplasma membrane cAMP generated by transmembrane AC, which strengthens endothelial barrier integrity. Endogenous soluble AC isoform 10 (AC10 or commonly known as sAC) lacks transmembrane domains and localizes within the cytosolic compartment. AC10 is uniquely activated by bicarbonate to generate cytosolic cAMP, yet its role in regulation of endothelial barrier integrity has not been addressed. Here we demonstrate that, within the pulmonary circulation, AC10 is expressed in pulmonary microvascular endothelial cells (PMVECs) and pulmonary artery endothelial cells (PAECs), yet expression in PAECs is lower. Furthermore, pulmonary endothelial cells selectively express bicarbonate cotransporters. While extracellular bicarbonate generates a phosphodiesterase 4-sensitive cAMP pool in PMVECs, no such cAMP response is detected in PAECs. Finally, addition of extracellular bicarbonate decreases resistance across the PMVEC monolayer and increases the filtration coefficient in the isolated perfused lung above osmolality controls. Collectively, these findings suggest that PMVECs have a bicarbonate-sensitive cytosolic cAMP pool that disrupts endothelial barrier integrity. These studies could provide an alternative mechanism for the controversial effects of bicarbonate correction of acidosis of acute respiratory distress syndrome patients. PMID:23686854

Obiako, Boniface; Calchary, Wendy; Xu, Ningyong; Kunstadt, Ryan; Richardson, Bianca; Nix, Jessica; Sayner, Sarah L

2013-05-17

385

A Buffer that Mimics the SMP Buffer for Determining Lime Requirement of Soil  

Microsoft Academic Search

The Shoemaker-McLean-Pratt (SMP) buffer used for determining lime requirement of soil contains chromium and p-nitrophenol, which classifies the solution as a hazardous waste. A buffer without hazard- ous chemicals producing the same pH as SMP buffer would eliminate hazardous waste and have no effect on agronomic interpretation. Chemicals chosen to replace chromium and p-nitrophenol were 2-(N- morpholino)ethanesulfonic acid monohydrate (MES)

F. J. Sikora

2006-01-01

386

Well-defined iron catalyst for improved hydrogenation of carbon dioxide and bicarbonate.  

PubMed

The most efficient, stable, and easy-to-synthesize non-noble metal catalyst system for the reduction of CO(2) and bicarbonates is presented. In the presence of the iron(II)-fluoro-tris(2-(diphenylphosphino)phenyl)phosphino]tetrafluoroborate complex 3, the hydrogenation of bicarbonates proceeds in good yields with high catalyst productivity and activity (TON > 7500, TOF > 750). High-pressure NMR studies of the hydrogenation of carbon dioxide demonstrate that the corresponding iron-hydridodihydrogen complex 4 is crucial in the catalytic cycle. PMID:23171468

Ziebart, Carolin; Federsel, Christopher; Anbarasan, Pazhamalai; Jackstell, Ralf; Baumann, Wolfgang; Spannenberg, Anke; Beller, Matthias

2012-12-11

387

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

388

Chaparral Conversion and Streamflow: Nitrate Increase Is Balanced Mainly by a Decrease in Bicarbonate  

NASA Astrophysics Data System (ADS)

Converting Arizona chaparral watersheds to grass by controlling the brush with herbicides increases water yield as subsurface runoff to streams. The increased stream discharge is accompanied by several hundredfold increases in the nitrate concentration of the stream water. Nitrate concentrations remained 46-69 fold above normal for 11 years or more. Nitrate ion concentration increases were balanced mainly by bicarbonate ion concentration decreases, with little change in the concentration of other anions or cations. One mechanism suggested to explain the decrease in bicarbonate that balances the increase in nitrate is the reaction of H+ NO3- with HCO3- to give carbon dioxide and water.

Davis, Edwin A.

1987-01-01

389

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

390

PROCESS FOR THE PRODUCTION OF AMMONIUM URANIUM FLUORIDE  

DOEpatents

This patent relates to the preparation of ammonium uranium fluoride. The process comprises adding a water soluble fluoride to an aqueous solution of a uranous compound containing an ammonium salt, and isolating the resulting precipitate. This patent relates to the manufacture of uranium tetnafluoride from ammonium uranium fluoride, NH/sub 4/UF/sub 5/. Uranium tetrafluoride is prepared by heating the ammonium uranium fluoride to a temperature at which dissociation occurs with liberation of ammonium fluoride. Preferably the process is carried out under reduced pressure, or in a current of an inert gas.

Ellis, A.S.; Mooney, R.B.

1953-08-25

391

Fluoridation of Hydroxyapatite Powder by Ammonium Hexafluorosilicate  

Microsoft Academic Search

Diamine silver fluoride [AgF: (NH3)2AgF] is a unique fluoride solution used clinically in Japan for primary teeth. AgF has been shown to reduce dental caries and dentine hypersensitivity. However, AgF also stains teeth black due to sulfide precipitation and thus is unacceptable for permanent teeth. In the present study, the potential value of ammonium hexafluorosilicate [SiF: (NH4)2SiF6], which has a

H. Murata; K. Ishikawa; S. Tenshin; S. Horiuchi; M. Nakanishi; K. Asaoka; T. Kawatai; T. T Yamamoto

1996-01-01

392

Modelling Ammonium Transporters in Arbuscular Mycorrhiza Symbiosis  

Microsoft Academic Search

\\u000a The Stochastic Calculus of Wrapped Compartments (SCWC) is a recently proposed variant of the Stochastic Calculus of Looping\\u000a Sequences (SCLS), a language for the representation and simulation of biological systems. In this work we apply SCWC to model\\u000a a newly discovered ammonium transporter. This transporter is believed to play a fundamental role for plant mineral acquisition,\\u000a which takes place in

Mario Coppo; Ferruccio Damiani; Maurizio Drocco; Elena Grassi; Mike Guether; Angelo Troina

393

Nitrification inhibitors ? Interaction with applied ammonium concentration  

Microsoft Academic Search

Soil samples of 50 g clay, clay loam and sandy loam were amended with ammonium sulphate giving 25, 50, 100, 200, and 400 mg nitrogen (N)\\/kg and with two nitrification inhibitors, Dicyandiamide (DCD) and N?Serve (N?S) each at two levels calculated relative to the N applied, 1 and 5%, and 0.5 and 1%, respectively. Water was added to moisture field

Jena Glasscock; Abraham Shaviv; Josef Hagin

1995-01-01

394

Anticaking and antidusting composition for ammonium nitrate  

SciTech Connect

An aqueous liquid anticaking and antidusting composition is described comprising, from 20 to 30 parts of a sodium naphthalene sulfonate, from 17 to 28 parts of an ammonium naphthalene sulfonate, the naphthalene of the aforesaid sulfonates being selected from naphthalene and methyl-substituted derivatives thereof, and from 30 to 80 parts of water, the composition being neutralized with acid to a pH of from about 5 to about 7.

Newman, A.W.; Bishop, M.L.

1988-01-05

395

Equation of State of Ammonium Nitrate  

NASA Astrophysics Data System (ADS)

Ammonium nitrate (AN) is a widely used fertilizer and mining explosive. AN is commonly used in ammonium nitrate-fuel oil (ANFO), which is a mixture of explosive-grade AN prills and fuel oil in a 94:6 ratio by weight. ANFO is a non-ideal explosive with measured detonation velocities around 4 km/s. The equation of state properties and known initiation behavior of neat AN are limited. We present the results of a series of gas gun-driven plate impact experiments on pressed neat ammonium nitrate at 1.72 g/cm3. No evidence of initiation was observed under shock loading to 22 GPa. High pressure x-ray diffraction experiments in diamond anvil cells provided insight into the high pressure phase behavior over the same pressure range (to 25 GPa), as well as a static isotherm at ambient temperature. From the isotherm and thermodynamic properties at ambient conditions, a preliminary unreacted equation of state (EOS) has been developed based on the Murnaghan isotherm and Helmholtz formalism [1], which compares favorably with the available experimental Hugoniot data on several densities of AN.

Robbins, David L.; Sheffield, Stephen A.; Dattelbaum, Dana M.; Velisavljevic, Nenad; Stahl, David B.

2009-12-01

396

Detection of the Ammonium Ion in Space  

NASA Astrophysics Data System (ADS)

We report on the detection of a narrow feature at 262816.73 MHz toward Orion and the cold prestellar core B1-bS which we attribute to the 10-00 line of the deuterated ammonium ion, NH3D+. The observations were performed with the IRAM 30 m radio telescope. The carrier has to be a light molecular species as it is the only feature detected over 3.6 GHz of bandwidth. The hyperfine structure is not resolved, indicating a very low value for the electric quadrupolar coupling constant of nitrogen which is expected for NH3D+ as the electric field over the N nucleus is practically zero. Moreover, the feature is right at the predicted frequency for the 10-00 transition of the ammonium ion, 262817 ± 6 MHz (3?), using rotational constants derived from new infrared data obtained in our laboratory in Madrid. The estimated column density is (1.1 ± 0.2) × 1012 cm-2. Assuming a deuterium enhancement similar to that of NH2D, we derive N(NH_4^+) ~= 2.6 × 1013 cm-2, i.e., an abundance for ammonium of a few 10-11. This work was based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain)

Cernicharo, J.; Tercero, B.; Fuente, A.; Domenech, J. L.; Cueto, M.; Carrasco, E.; Herrero, V. J.; Tanarro, I.; Marcelino, N.; Roueff, E.; Gerin, M.; Pearson, J.

2013-07-01

397

Temperature buffer test design, instrumentation and measurements  

NASA Astrophysics Data System (ADS)

The Temperature Buffer Test, TBT, is a heated full-scale field experiment carried out jointly by ANDRA and SKB at the SKB Äspö Hard Rock Laboratory in Southeast Sweden. An existing 8 m deep, 1.8 m diameter KBS-3-type deposition hole located at -420 m level has been selected for the test. The objectives are to improve the general understanding of Thermo-Hydro-Mechanical, THM, behavior of buffer materials submitted to severe thermal conditions with temperatures well over 100 °Cduring water uptake of partly saturated bentonite-based buffer materials,and to check, in due time, their properties after water saturation. The test includes two carbon steel heating canisters each 3 m high and 0.6 m diameter, surrounded by 0.6 m of buffer material. There is a 0.2 m thick sand shield between the upper heater and the surrounding bentonite, while the lower heater is surrounded by bentonite only. On top of the stack of bentonite blocks is a confining plug anchored to the rock. In the slot between buffer and rock wall is a sand filter equipped with pipes to control the water pressure at the boundary, which is seldom done with an EBS in situ experiment. Both heater mid-height planes are densely instrumented in order to follow, with direct or indirect methods, buffer THM evolution. Temperature, relative humidity, stress and pore pressure have been monitored since the test start in March 2003. Total water inflow is also monitored. Firstly, the present paper describes the test design, the instrumentation, the plug anchoring system and the system for water boundary pressure control. Second, having described the test, the paper shows different measurements that illustrate evolution of temperature, saturation, suction and swelling pressure in the upper and the lower buffer.

Sandén, Torbjörn; Goudarzi, Reza; de Combarieu, Michel; Åkesson, Mattias; Hökmark, Harald

398

A Proposed Mechanism for the Stimulatory Effect of Bicarbonate Ions on ATP Synthesis in Isolated Chloroplasts 1  

PubMed Central

The effect of bicarbonate ions on induction of Mg2+-ATPase activity, on the N-ethylmaleimide inhibition of phosphorylation and on energy-dependent adenine nucleotide exchange has been examined with pea seedling chloroplasts. Incubation of chloroplasts with N-ethylmaleimide in the presence of 15 millimolar bicarbonate in the light results in enhanced inhibition of ATP synthesis when the preillumination pH is maintained between 7.0 and 7.5. Bicarbonate also enhances Mg2+-ATPase activity when it is included in the light-triggering stage at pH 7.0. The conditions (medium pH, bicarbonate concentration, etc.) for demonstrating the bicarbonate-induced enhancement of the N-ethylmaleimide inhibition and ATPase activity are similar to those required for the direct effect of bicarbonate on phosphorylation. Bicarbonate, under the same conditions, does not affect adenine nucleotide exchange (binding or release). It is concluded that the stimulatory effect of bicarbonate on ATP synthesis may be related to its ability to alter directly the conformation of the chloroplast coupling factor under conditions (suboptimal pH) where the enzyme shows minimal activity.

Cohen, William S.; MacPeek, Wendy A.

1980-01-01

399

Practical experience with the use of Baking Powder (potassium bicarbonate) for the control of Apple Scab (Venturia ineaqualis)  

Microsoft Academic Search

In small plot trials, performed by several institutes in the past years, potassium bicarbonate proved to be a promising alternative to the use of copper for the control of apple scab in organic orchards. Feasibility, effectiveness, consequences, and side effects of the replacement of copper by bicarbonate under practical conditions are largely unknown. In 2007 Five Dutch organic apple growers

M. Trapman

400

Ammonium secretion by Malpighian tubules of Drosophila melanogaster: application of a novel ammonium-selective microelectrode.  

PubMed

Ammonia is a toxic nitrogenous waste product of amino acid metabolism that may accumulate to high levels in the medium ingested by larvae of the fruit fly Drosophila melanogaster. Here we report measurements of haemolymph NH4(+) concentration and the secretion of NH4(+) by the Malpighian (renal) tubules. Measurement of NH4(+) concentrations in secreted droplets is complicated either by the requirement for large sample volumes for enzymatic assays or by the inadequate selectivity of NH4(+)-selective microelectrodes based on nonactin. We have developed a novel liquid membrane NH4(+)-selective microelectrode based on a 19-membered crown compound (TD19C6), which has been used previously in ammonium-selective macroelectrodes. In conjunction with an improved technique for correcting for interference of potassium, NH4(+)-selective microelectrodes based on TD19C6 permit accurate measurement of ammonium concentration in haemolymph samples and nanolitre droplets of fluid secreted by the Malpighian tubules of D. melanogaster. The results indicate that active secretion of ammonium into the Malpighian tubule lumen is sufficient to maintain concentrations of ~1 mmol l(-1) ammonium in the haemolymph of larvae reared on diets containing 100 mmol l(-1) ammonium chloride. PMID:23821719

Browne, Austin; O'Donnell, Michael J

2013-07-02

401

Freezability of rat epididymal sperm induced by raffinose in modified Krebs-Ringer bicarbonate (mKRB) based extender solution.  

PubMed

The objective of this study was to develop an ideal freezing extender and method for rat epididymal sperm cryopreservation. Epididymal sperm collected from 30 Wistar males was frozen, and experiments were conducted to study its post-thaw characteristics when freezing with raffinose-free buffer or various concentrations of raffinose and egg yolk dissolved in distilled and deionised water, PBS, or modified Krebs-Ringer bicarbonate (mKRB)-based extender. Different concentrations of glycerol, Equex STM, or sodium dodecyl sulfate (SDS) dissolved in either PBS or mKRB containing egg yolk were also tested. Based on the data from these experiments, further experiments tested how different sugars such as raffinose, trehalose, lactose, fructose, and glucose dissolved in mKRB with Equex STM, SDS and egg yolk supplementation affected the post-thaw characteristics of cryopreserved sperm. Cryosurvival of frozen-thawed sperm were judged by microscopic assessment of the sperm motility index (SMI), and acrosome integrity was measured using FITC-PNA staining. Thawed sperm were subjected to 3h of a thermal resistance test. Beneficial effects on the post-thaw survival of sperm were obtained when 0.1M raffinose in mKRB was used with 0.75% Equex STM, 0.05% SDS, and 20% egg yolk. Sperm cryopreserved with this treatment exhibited a higher motility index and maintained greater SMI and acrosome integrity throughout incubation when compared to sperm frozen in various concentrations of other cryoprotectants and trehalose, lactose, fructose, glucose. In conclusion, cryopreservation in an extender solution of raffinose dissolved in mKRB containing Equex STM, SDS and egg yolk greatly enhances the freezability of rat epididymal sperm. PMID:17923121

Yamashiro, Hideaki; Han, Young-Joon; Sugawara, Atsushi; Tomioka, Ikuo; Hoshino, Yumi; Sato, Eimei

2007-09-08

402

Bicarbonate, NBCe1, NHE, and Carbonic Anhydrase Activity Enhance Lactate-H+ Transport in Bovine Corneal Endothelium  

PubMed Central

Purpose. To identify and localize the monocarboxylate transporters (MCTs) expressed in bovine corneal endothelial cells (BCEC) and to test the hypothesis that buffering contributed by HCO3?, sodium bicarbonate cotransporter (NBCe1), sodium hydrogen exchanger (NHE), and carbonic anhydrase (CA) activity facilitates lactate flux. Methods. MCT1–4 expression was screened by RT-PCR, Western blot analysis, and immunofluorescence. Endogenous lactate efflux and/or pHi were measured in BCEC in HCO3?-free or HCO3?-rich Ringer, with and without niflumic acid (MCT inhibitor), acetazolamide (ACTZ, a CA inhibitor), 5-(N-Ethyl-N-isopropyl)amiloride (EIPA) (Na+/H+ exchange blocker), disodium 4,4?-diisothiocyanatostilbene-2,2?-disulfonate (DIDS; anion transport inhibitor), or with NBCe1-specific small interfering (si) RNA-treated cells. Results. MCT1, 2, and 4 are expressed in BCEC. MCT1 was localized to the lateral membrane, MCT2 was lateral and apical, while MCT4 was apical. pHi measurements showed significant lactate-induced cell acidification (LIA) in response to 20-second pulses of lactate. Incubation with niflumic acid significantly reduced the rate of pHi change (dpHi/dt) and lactate-induced cell acidification. EIPA inhibited alkalinization after lactate removal. Lactate-dependent proton flux was significantly greater in the presence of HCO3? but was reduced by ACTZ. Efflux of endogenously produced lactate was significantly faster in the presence of HCO3?, was greater on the apical surface, was reduced on the apical side by ACTZ, as well as on the apical and basolateral side by NBCe1-specific siRNA, DIDS, or EIPA. Conclusions. MCT1, 2, and 4 are expressed in BCEC on both the apical and basolateral membrane (BL) surfaces consistent with niflumic acid-sensitive lactate-H+ transport. Lactate dependent proton flux can activate Na+/H+ exchange and be facilitated by maximizing intracellular buffering capacity through the presence of HCO3?, HCO3? transport, NHE and CA activity.

Nguyen, Tracy T.

2011-01-01

403

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

404

Prevention of Irinotecan-Induced Diarrhea by Oral Sodium Bicarbonate and Influence on Pharmacokinetics  

Microsoft Academic Search

Alkalization of the intestinal tract by oral administration of sodium bicarbonate has been reported to be a promising method for preventing delayed diarrhea, a dose-limiting toxicity in patients receiving chemotherapy with irinotecan hydrochloride. However, it is feared that this method may adversely affect the pharmacokinetics of irinotecan by inhibiting its intestinal absorption and that of its active metabolites. We compared

Takao Tamura; Koichi Yasutake; Hogara Nishisaki; Takatoshi Nakashima; Kazutugu Horita; Sigeya Hirohata; Arata Ishii; Kenichi Hamano; Nobuo Aoyama; Daisuke Shirasaka; Takashi Kamigaki; Masato Kasuga

2004-01-01

405

ROLE OF DISSOLVED ORGANIC MATTER, NITRATE, AND BICARBONATE IN THE PHOTOLYSIS OF AQUEOUS FIPRONIL  

Technology Transfer Automated Retrieval System (TEKTRAN)

A multivariate kinetic model of the photodegradation of aqueous fipronil was developed as a function of dissolved organic matter (DOM), bicarbonate, and nitrate at concentrations that bracket those commonly observed in natural waters (ca. 0-10 mg/L). Several pathways were available for fipronil pho...

406

Evidence for an Inhibitory Effect of Kallikrein on Collecting Duct Bicarbonate Secretion in Rats and Rabbits  

Microsoft Academic Search

The luminal membrane of collecting duct cells, especially the intercalated cells, is normally exposed to active kallikrein. This is the consequence of the specific localization of this renal enzyme in the connecting tubule cells and its principal route of secretion being into the tubular lumen. It is conceivable that kallikrein acts downstream on a transporter involved in distal bicarbonate handling.

Marcos Marin-Grez; Patricia Vallés

1994-01-01

407

The magnitude of metabolic acidosis is dependent on differences in bicarbonate assays  

Microsoft Academic Search

Metabolic acidosis has been recently recognized as an important comorbid event in the high mortality rates seen in patients with end-stage renal disease. The recognition of hypobicarbonatemia is dependent on a reliable assay for total carbon dioxide (TCO2). It is common practice for dialysis facilities to send blood samples for testing to remote laboratories, which may assay bicarbonate differently than

Susan H. Bray; Ru-Lin Tung; Edward R. Jones

1996-01-01

408

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

409

Oral Sodium Bicarbonate Improves Thyroid Function in Predialysis Chronic Kidney Disease  

Microsoft Academic Search

Background\\/Aims: Metabolic acidosis (MA) in chronic kidney disease (CKD) associates with protein energy malnutrition, osteoporosis, abnormal endocrine function and increased mortality. Oral sodium bicarbonate has been shown to improve nutritional status and preserve renal function in CKD. Depressed thyroid function has been described in CKD and was believed to be related to MA. This is a prospective randomized study that

Sinee Disthabanchong; Akarapong Treeruttanawanich

2010-01-01

410

Calcium and bicarbonate effects on the growth and nutrient uptake of burley tobacco seedlings: Float system  

Microsoft Academic Search

High levels of bicarbonate (HCO3 ) alkalinity have been shown to affect the growth and nutrient uptake of tobacco seedlings in solution culture. The objective of this study was to determine the effect of HCO3 on the nutrient uptake of burley tobacco seedlings grown in a float system. Float bays of a size to accommodate individual float trays were filled

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

1999-01-01

411

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

412

Adding Sodium Bicarbonate to Lidocaine Enhances the Depth of Epidural Blockade  

Microsoft Academic Search

It is controversial whether adding CO, or sodium bicar- bonate to local anesthetics enhances the depth of epi- dural blockade. Repeated electrical stimulation is a re- liable test for assessing epidural analgesia and evokes temporal summation. We used this test to investigate the analgesic effect of lidocaine, with or without CO, or bicarbonate. Twenty-four patients undergoing epi- dural blockade with

Michele Curatolo; Steen Petersen-Felix; Lars Arendt-Nielsen; Rolf Lauber; Henrik Hogstrom; Pasquale Scaramozzino; Martin Luginbiihl; Thomas J. Sieber; Alex M. Zbinden

1998-01-01

413

Combating inadequate anesthesia in periapical infections, with sodium bicarbonate: a clinical double blind study.  

PubMed

INTRODUCTION: Local anesthetics are generally much less effective when administered in inflamed tissues. PURPOSE: This study was conducted to validate the addition of sodium bicarbonate in local anesthetics to increase its effectiveness as local infiltrations in teeth associated with periapical infections. METHODS: Two hundred subjects requiring extraction of maxillary teeth with periapical infections were enrolled. These subjects were divided in two groups of 100 subjects each. One group received local infiltration with 2 % lignocaine and 1:80,000 adrenaline, and the other group received local infiltration with sodium bicarbonate as an adjunct to the above mentioned local anesthetic solution. All extractions were performed using a consistent intra-alveolar technique by a single operator. Both the patient and the operator were blinded to the contents of local anesthetic solution. Data related to the onset of action of local anesthesia, pain experienced by the patient while undergoing extraction on two scales-"the visual analog scale and the verbal response scale", and any requirement of repeated injections during the procedure was recorded. RESULTS: Clinical and statistical data confirmed that the addition of sodium bicarbonate in local anesthetics did increase the efficacy of local anesthesia in inflamed tissues. CONCLUSION: It has been observed in this study that the action of sodium bicarbonate in local anesthetics increases the pH levels of these solutions, thus possibly making them more effective in an acidic environment. PMID:23740399

Gupta, Savina; Mandlik, Geetanjali; Padhye, Mukul N; Kini, Yogesh K; Kakkar, Shruti; Hire, Abhinav Vijay

2013-06-01

414

Highly Catalytic Enantioselective Epoxidation of Enones with Weak Base Bicarbonate and Hydrogen Peroxide  

Microsoft Academic Search

The weak basic bicarbonate-activated hydrogen peroxide is applied to the catalytic asymmetric epoxidation of the enones, and the catalyst polyleucine cannot be deteriorated and can successfully be reused in this asymmetric reaction. The ee value of the optically active epoxidation product is up to 95%.

Chao-Shan Da; Jie Wei; Shou-Liang Dong; Zhuo-Qun Xin; Da-Xue Liu; Zhao-Qin Xu; Rui Wang

2003-01-01

415

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

416

Corrosion-fatigue durability of pipe steel in carbonate-bicarbonate medium  

Microsoft Academic Search

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

I. G. Abdullin; A. G. Gareev

1994-01-01

417

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...

418

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

419

Labview virtual instruments for calcium buffer calculations.  

PubMed

Labview VIs based upon the calculator programs of Fabiato and Fabiato (J. Physiol. Paris 75 (1979) 463) are presented. The VIs comprise the necessary computations for the accurate preparation of multiple-metal buffers, for the back-calculation of buffer composition given known free metal concentrations and stability constants used, for the determination of free concentrations from a given buffer composition, and for the determination of apparent stability constants from absolute constants. As implemented, the VIs can concurrently account for up to three divalent metals, two monovalent metals and four ligands thereof, and the modular design of the VIs facilitates further extension of their capacity. As Labview VIs are inherently graphical, these VIs may serve as useful templates for those wishing to adapt this software to other platforms. PMID:12468127

Reitz, Frederick B; Pollack, Gerald H

2003-01-01

420

Schemes for Implementing Buffer Sharing in Continuous-Media Systems  

Microsoft Academic Search

Buffer management in continuous-media systems is a frequently studied topic. One ofthe most interesting recent proposals is the idea of buffer sharing for concurrent streams. As analyzedin [6], by taking advantage of the temporal behaviour of concurrent streams, buffer sharing can leadto a 50% savings in total buffer space. In this paper, we study how to actually implement buffersharing. To

Dwight J. Makaroff; Raymond T. Ng

1995-01-01

421

Buffer Dimensioning for Delay and Loss-Sensitive Traffic  

Microsoft Academic Search

Multiplexing of delay- and loss-sensitive traffic requires a common analytical framework for buffer dimensioning, buffer sharing schemes, as well as buffer entry and exit priorities. This paper performs a relevant study by employing discrete-time queueing techniques, appropriate for the small buffer sizes envisaged in ATM technology. The model, solution method and relevant metrics are presented. The numerical results are critically

Kimon P Kontovassilis; John T Tsiligaridis; George I. Stassinopoulos

1995-01-01

422

Distributed scheduling based on due dates and buffer prioritization  

Microsoft Academic Search

The problem of scheduling a semiconductor manufacturing facility is addressed. Several buffer priority and due-date based scheduling policies for nonacyclic flow lines are studied. Not all buffer priority policies are stable, as is shown by a counterexample. However, the first buffer first serve and last buffer first serve policies are stable. Also, the earliest due data and least-slack policies are

C.-H. Lu; P. R. Kumar

1990-01-01

423

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.

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

2011-01-01

424

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

425

Grass buffers for playas in agricultural landscapes: an annotated bibliography  

USGS Publications Warehouse

This bibliography and associated literature synthesis (Melcher and Skagen, 2005) was developed for the Playa Lakes Joint Venture (PLJV). The PLJV sought compilation and annotation of the literature on grass buffers for protecting playas from runoff containing sediments, nutrients, pesticides, and other contaminants. In addition, PLJV sought information regarding the extent to which buffers may attenuate the precipitation runoff needed to fill playas, and avian use of buffers. We emphasize grass buffers, but we also provide information on other buffer types.

Melcher, Cynthia P.; Skagen, Susan K.

2005-01-01

426

Performance Analysis of Buffering Schemes on Wormhole Routers  

Microsoft Academic Search

Wormhole switched input-buffered and middle-buffered routers with virtual channels are analyzed in this paper. Middle buffering refers to the placement of virtual channels between the demultiplexers and multiplexers of a crossbar switch. An analytical model for multistage interconnection networks using middle-buffered switches is developed. In addition, extensive simulation is conducted to assess the performance of the two buffering techniques in

Younes M. Boura; Chita R. Das

1997-01-01

427

Detonation Properties of Powdered Ammonium Nitrate  

NASA Astrophysics Data System (ADS)

It was studied the parameters of detonation of Ammonium Nitrate (powder) The detonation properties of industrial explosive Ammonite 6 which is mixture of TNT 20% and AN 80% and THT powdered were compared. By using the known formula for detonation characteristic of the mixture of different HE it was estimated that the upper limit of detonation of AN by itself must be not less than 5 km per sec. The large-scale experiments with plane charges of AN with the thickness of layer of AN 200mm were made. The measured detonation velocity appeared to be 5 km per sec.

Deribas, Andrei A.; Simonov, Valery A.

1999-06-01

428

Benzyl-ammonium hexa-noate  

PubMed Central

A binary mixture of benzyl­amine and hexa­noic acid has been reacted to form the title salt, C7H10N+·C6H11O2 ?. This crystal has a 1:1 stoichiometry of acid- and amine-derived species which contrasts with other related species which can have a number of other integer ratios of acid and amine components. The diffraction data indicate complete transfer of a proton from the acid to the amine to give the salt, comprising a cation and anion combination, with the formation of three hydrogen bonds around each ammonium group. This contrasts with other related species.

Wood, Mary H.; Clarke, Stuart M.

2012-01-01

429

Systemic Buffers Inhibit Carcinogenesis in TRAMP Mice  

PubMed Central

Purpose Hypoxia and acidosis develop in in situ tumors as cellular expansion increases the diffusion distance of substrates and metabolites from blood vessels deep to the basement membrane. Prior studies of breast and cervical cancer revealed that cellular adaptation to microenvironmental hypoxia and acidosis is associated with the transition from in situ to invasive cancer. We hypothesized that decreased acidosis in intraductal tumors would alter environmental selection pressures for acid adapted phenotypes and delay or prevent evolution to invasive cancer. Materials and Methods A total of 37 C57BL/6 TRAMP mice were randomized to a control group or to 1 of 4 treatment groups. In the latter groups 200 mM sodium bicarbonate were added to drinking water starting between ages 4 and 10 weeks. Results In all 18 controls prostate cancer developed that was visible on 3-dimensional ultrasound at a mean age of 13 weeks. They died within 52 weeks (median 37). When sodium bicarbonate therapy commenced before age 6 weeks in 10 mice, all reached senescence (age 76 weeks) without radiographic evidence of prostate cancer. Histological sections of the prostates in this cohort showed hyperplasia but no cancer in 70% of mice and minimal well differentiated cancer in the remainder. When therapy commenced after age 6 weeks in 9 mice, prostate cancer development was no different from that in controls. Conclusions Immunohistochemical staining for carbonic anhydrase 9 in regions of ductal hyperplasia showed increased expression in controls vs the early treatment group. Regional pH perturbation in in situ tumors may be a simple, inexpensive and effective cancer prevention strategy.

Ibrahim-Hashim, Arig; Cornnell, Heather H.; Abrahams, Dominique; Lloyd, Mark; Bui, Marilyn; Gillies, Robert J.; Gatenby, Robert A.

2013-01-01

430

Post-harvest Riparian Buffer Response: Implications for Wood Recruitment Modeling and Buffer Design  

NASA Astrophysics Data System (ADS)

Despite the importance of riparian buffers in providing aquatic functions to forested streams, few studies have sought to capture key differences in ecological and geomorphic processes between buffered sites and forested conditions. This study examines post-harvest buffer conditions from 20 randomly selected harvest sites within a managed tree farm in the Cascade Mountains of western Washington. Post-harvest wind derived treefall rates in buffers up to three years post-harvest averaged 268 trees/km/year, 26 times greater than competition-induced mortality rate estimates. Treefall rates and stem breakage were strongly tied to tree species and relatively unaffected by stream direction. Observed treefall direction is strongly biased toward the channel, irrespective of channel or buffer orientation. Fall direction bias can deliver significantly more wood recruitment relative to randomly directed treefall, suggesting that models that utilize the random fall assumption will significantly underpredict recruitment. A simple estimate of post-harvest wood recruitment from buffers can be obtained from species specific treefall and breakage rates, combined with bias corrected recruitment probability as a function of source distance from the channel. Post-harvest wind effects may reduce the standing density of trees enough to significantly reduce or eliminate competition mortality and thus indirectly alter bank erosion rates, resulting in substantially different wood recruitment dynamics from buffers as compared to unmanaged forests.

Liquori, Michael K.

2006-02-01

431

Managing Buffer Stocks to Stabilize Wheat Prices.  

National Technical Information Service (NTIS)

A wheat buffer stock simulation model is used to add random deviations of wheat yields and exports to projected supply and demand conditions for 1976-82. The result is a useful analytical tool for policy analysis-especially for the analysis of questions a...

J. A. Sharples R. L. Walker R. W. Slaughter

1976-01-01

432

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

433

Specifying memory consistency of write buffer multiprocessors  

Microsoft Academic Search

Write buffering is one of many successful mechanisms that improves the performance and scalability of multiprocessors. However, it leads to more complex memory system behavior, which cannot be described using intuitive consistency models, such as Sequential Consistency. It is crucial to provide programmers with a specification of the exact behavior of such complex memories. This article presents a uniform framework

Lisa Higham; Lillanne Jackson; Jalal Kawash

2007-01-01

434

Lexical influences in graphemic buffer disorder  

Microsoft Academic Search

We report the case of patient BH, who misspelled about half of the words she attempted and showed the characteristic features of “graphemic buffer disorder” (an effect of letter length on spelling accuracy, errors involving the substitution, omission, addition, and movement of letters that affect the middles more than the ends of words). Speech comprehension and production were good. Reading

Karen Sage; Andrew W. Ellis

2004-01-01

435

The Graphemic Buffer and attentional mechanisms*1  

Microsoft Academic Search

Two patients with acquired dysgraphia were reported. The patients' performance in various written and oral spelling tasks converge in support of the hypothesis that they have selective damage, within the spelling system, to the Graphemic Buffer. Although the patients present with comparable patterns of error types, they differ in the distribution of errors as a function of letter position in

ARGYE E. HILLIS; ALFONSO CARAMAZZA

1989-01-01

436

How tendons buffer energy dissipation by muscle.  

PubMed

To decelerate the body and limbs, muscles lengthen actively to dissipate energy. During rapid energy-dissipating events, tendons buffer the work done on muscle by storing elastic energy temporarily, 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

2013-10-01

437

Buffer Size Requirements Under Longest Queue First  

Microsoft Academic Search

A model of a switching component in a packet switching network is considered. Packetsfrom several incoming channels arrive and must be routed to the appropriate outgoingport according to a service policy. A task confronting the designer of such a system is theselection of policy and the determination of the corresponding input buffer requirementswhich will prevent packet loss. One natural choice

H. Richard Gail; George A. Grover; Roch Guérin; Sidney L. Hantler; Zvi Rosberg; Moshe Sidi

1993-01-01

438

Stress, Social Support, and the Buffering Hypothesis  

Microsoft Academic Search

The purpose of this article is to determine whether the positive association between social support and well-being is attributable more to an overall beneficial effect of support (main- or direct-effect model) or to a process of support protecting persons from potentially adverse effects of stressful events (buffering model). The review of studies is organized according to (a) whether a measure

Sheldon Cohen; Thomas Ashby Wills

1985-01-01

439

Solid Solutions in the System Ammonium Nitrate-Potassium Nitrate  

Microsoft Academic Search

BY phase work on the system ammonium nitrate-potassium nitrate-water, Janëcke1,2 showed that below 23° C. two types of solid solution can exist: potassium nitrate dissolved in ammonium nitrate (form III) and ammonium nitrate in potassium nitrate (form II). At higher temperatures there is an increasing amount of another phase which is of a different crystalline form from any of the

R. V. Coates; J. M. Crewe

1961-01-01

440

Removal of Ammonium from Tannery Wastewater by Electrochemical Treatment  

Microsoft Academic Search

The removal of ammonium from coagulated tannery wastewaters was investigated by an electrochemical method using Ti\\/IrO2 as an anode. Operating variables including the current density, pH and chloride concentration were considered in order to determine their effect on the ammonium removal efficiency. A maximum ammonium removal rate of 78.9% was achieved after 30 min of electrochemical treatment with 4 A dm of current

Kyung-Sok Min; Jae-Jeong Yu; Young-Ju Kim; Zuwhan Yun

2004-01-01

441

Oxygen affects the ability of mouse blastocysts to regulate ammonium.  

PubMed

During embryo culture, ammonium is generated by amino acid metabolism and from the spontaneous deamination of amino acids at 37°C. Although ammonium has been shown to be embryo toxic, few studies have investigated the mechanism(s) by which the early embryo can regulate ammonium. Whilst 20% oxygen represents a source of stress to the developing embryo, it is not known how oxygen affects the physiology of the embryo in the presence of other sources of stress. The aim of this study was, therefore, to investigate possible pathways involved in ammonium sequestration in the preimplantation embryo and the effect of oxygen on the regulation of these pathways. Glutamine and alanine were investigated as possible ammonium sequestration pathways. Amino acid utilization by blastocysts was determined after culture from the postcompaction stage with 0, 150, or 300 ?M ammonium (in either 5% or 20% oxygen) and with or without 500 ?M L-methionine sulfoximine (MSO), an inhibitor of glutamine synthetase. In the presence of MSO, ammonium production was significantly increased and glutamate was no longer consumed. Glutamine synthetase inhibition with MSO significantly decreased glutamine formation. Ammonium and oxygen independently altered overall amino acid turnover. Together, 5% oxygen and ammonium promoted glutamine production, whereas in the presence of 20% oxygen and ammonium, glutamine was consumed. Data reveal that both oxygen and ammonium affect amino acid utilization by the developing embryo, however, 20% oxygen appears to have the greater impact. Mouse blastocysts can alleviate ammonium stress by its transamination to both glutamine and alanine, but only under physiological conditions. PMID:23803557

Wale, Petra L; Gardner, David K

2013-09-27

442

Surge ammonium uptake in macroalgae from a coral atoll  

Microsoft Academic Search

Surge (non-linear) uptake of ammonium, measured by incorporation of 15N, was investigated in three species of macroalgae (Ulva lactuca Linnaeus (Chlorophyta), Soliera robusta (Greville) Kylin (Rhodophyta) and Dictyota dichotoma (Hudson) Lamouroux (Phaeophyta)) from Kavaratti atoll (Lakshadweep, India). Addition of ammonium (up to 20 ?mol L?1) led to pronounced uptake within 4–6 min, with the amount of ammonium taken up during surge phase

Varsha Raikar; Mohideen Wafar

2006-01-01

443

Anaerobic ammonium oxidation discovered in a denitrifying fluidized bed reactor  

Microsoft Academic Search

Until now, oxidation of ammonium has only been known to proceed under aerobic conditions. Recently, we observed that NH4+ was disappearing from a denitrifying fluidized bed reactor treating effluent from a methanogenic reactor. Both nitrate and ammonium consumption increased with concomitant gas production. A maximum ammonium removal rate of 0.4 kg N · m?3 · d?1 (1.2 mM\\/h) was observed.

A. Mulder; A. A. van de Graaf; L. A. Robertson; J. G. Kuenen

1995-01-01

444

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

445

Molecular mechanism of anaerobic ammonium oxidation.  

PubMed

Two distinct microbial processes, denitrification and anaerobic ammonium oxidation (anammox), are responsible for the release of fixed nitrogen as dinitrogen gas (N(2)) to the atmosphere. Denitrification has been studied for over 100 years and its intermediates and enzymes are well known. Even though anammox is a key biogeochemical process of equal importance, its molecular mechanism is unknown, but it was proposed to proceed through hydrazine (N(2)H(4)). Here we show that N(2)H(4) is produced from the anammox substrates ammonium and nitrite and that nitric oxide (NO) is the direct precursor of N(2)H(4). We resolved the genes and proteins central to anammox metabolism and purified the key enzymes that catalyse N(2)H(4) synthesis and its oxidation to N(2). These results present a new biochemical reaction forging an N-N bond and fill a lacuna in our understanding of the biochemical synthesis of the N(2) in the atmosphere. Furthermore, they reinforce the role of nitric oxide in the evolution of the nitrogen cycle. PMID:21964329

Kartal, Boran; Maalcke, Wouter J; de Almeida, Naomi M; Cirpus, Irina; Gloerich, Jolein; Geerts, Wim; Op den Camp, Huub J M; Harhangi, Harry R; Janssen-Megens, Eva M; Francoijs, Kees-Jan; Stunnenberg, Hendrik G; Keltjens, Jan T; Jetten, Mike S M; Strous, Marc

2011-10-02

446

Ammonium nitrate: a promising rocket propellant oxidizer  

PubMed

Ammonium nitrate (AN) is extensively used in the area of fertilizers and explosives. It is present as the major component in most industrial explosives. Its use as an oxidizer in the area of propellants, however, is not as extensive as in explosive compositions or gas generators. With the growing demand for environmental friendly chlorine free propellants, many attempts have been made of late to investigate oxidizers producing innocuous combustion products. AN, unlike the widely used ammonium perchlorate, produces completely ecofriendly smokeless products. Besides, it is one of the cheapest and easily available compounds. However, its use in large rocket motors is restricted due to some of its adverse characteristics like hygroscopicity, near room temperature phase transformation involving a volume change, and low burning rate (BR) and energetics. The review is an attempt to consolidate the information available on the various issues pertaining to its use as a solid propellant oxidizer. Detailed discussions on the aspects relating to phase modifications, decomposition chemistry, and BR and energetics of AN-based propellants, are presented. To make the review more comprehensive brief descriptions of the history, manufacture, safety, physical and chemical properties and various other applications of the salt are also included. Copyright 1999 Elsevier Science B.V. PMID:10370180

Oommen; Jain

1999-06-30

447

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

PubMed

Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss. 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

2012-05-23

448

Diversity of ammonium-oxidizing bacteria in a granular sludge anaerobic ammonium-oxidizing (anammox) reactor.  

PubMed

The ammonium-oxidizing microbial community was investigated in a granular sludge anaerobic ammonium-oxidizing (anammox) reactor that was operated for about 1 year with high anaerobic ammonium oxidation activity (up to 0.8 kg NH(4)(+)-N m(-3) day(-1)). A Planctomycetales-specific 16S rRNA gene library was constructed to analyse the diversity of the anaerobic ammonium-oxidizing bacteria (AnAOB). Most of the specifically amplified sequences (15/16) were similar to each other (> 99%) but were distantly related to all of the previously recognized sequences (< 94%), with the exception of an unclassified anammox-related clone, KSU-1 (98%). An ammonia monooxygenase (amoA) gene library was also analysed to investigate the diversity of 'aerobic' ammonium-oxidizing bacteria (AAOB) from the beta-Proteobacteria. Most of the amoA gene fragments (53/55) clustered in the Nitrosomonas europaea-Nitrosococcus mobilis group which has been reported to prevail under oxygen-limiting conditions. The quantitative results from real-time polymerase chain reaction (PCR) amplification showed that the dominant AnAOB comprised approximately 50% of the total bacterial 16S rRNA genes in the reactor, whereas the AAOB of beta-Proteobacteria represented only about 3%. A large fragment (4008 bp) of the rRNA gene cluster of the dominant AnAOB (AS-1) in this reactor sludge was sequenced and compared with sequences of other Planctomycetales including four anammox-related candidate genera. The partial sequence of hydrazine-oxidizing enzyme (hzo) of dominant AnAOB was also identified using new designed primers. Based on this analysis, we propose to tentatively name this new AnAOB Candidatus'Jettenia asiatica'. PMID:18479446

Quan, Zhe-Xue; Rhee, Sung-Keun; Zuo, Jian-E; Yang, Yang; Bae, Jin-Woo; Park, Ja Ryeong; Lee, Sung-Taik; Park, Yong-Ha

2008-05-09

449

Sodium Bicarbonate Treatment during Transient or Sustained Lactic Acidemia in Normoxic and Normotensive Rats  

PubMed Central

Introduction Lactic acidosis is a frequent cause of poor outcome in the intensive care settings. We set up an experimental model of lactic acid infusion in normoxic and normotensive rats to investigate the systemic effects of lactic acidemia per se without the confounding factor of an underlying organic cause of acidosis. Methodology Sprague Dawley rats underwent a primed endovenous infusion of L(+) lactic acid during general anesthesia. Normoxic and normotensive animals were then randomized to the following study groups (n?=?8 per group): S) sustained infusion of lactic acid, S+B) sustained infusion+sodium bicarbonate, T) transient infusion, T+B transient infusion+sodium bicarbonate. Hemodynamic, respiratory and acid-base parameters were measured over time. Lactate pharmacokinetics and muscle phosphofructokinase enzyme's activity were also measured. Principal Findings Following lactic acid infusion blood lactate rose (P<0.05), pH (P<0.05) and strong ion difference (P<0.05) drop. Some rats developed hemodynamic instability during the primed infusion of lactic acid. In the normoxic and normotensive animals bicarbonate treatment normalized pH during sustained infusion of lactic acid (from 7.22±0.02 to 7.36±0.04, P<0.05) while overshoot to alkalemic values when the infusion was transient (from 7.24±0.01 to 7.53±0.03, P<0.05). When acid load was interrupted bicarbonate infusion affected lactate wash-out kinetics (P<0.05) so that blood lactate was higher (2.9±1 mmol/l vs. 1.0±0.2, P<0.05, group T vs. T+B respectively). The activity of phosphofructokinase enzyme was correlated with blood pH (R2?=?0.475, P<0.05). Conclusions pH decreased with acid infusion and rose with bicarbonate administration but the effects of bicarbonate infusion on pH differed under a persistent or transient acid load. Alkalization affected the rate of lactate disposal during the transient acid load.

Valenza, Franco; Pizzocri, Marta; Salice, Valentina; Chevallard, Giorgio; Fossali, Tommaso; Coppola, Silvia; Froio, Sara; Polli, Federico; Gatti, Stefano; Fortunato, Francesco; Comi, Giacomo P.; Gattinoni, Luciano

2012-01-01

450

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

451

Cleavage of the PO glycoprotein of the rat peripheral nerve myelin: Tentative identification of cleavage site and evidence for the precursor-product relationship  

Microsoft Academic Search

The incubation of sciatic nerve slices in Krebs Ringer bicarbonate (KRB) buffer (pH 7.4) at 37°C, or the incubation of freshly isolated myelin in ammonium bicarbonate buffer (pH 8), resulted in the generation of a 24kDa protein with a concomitant decrease of PO protein. The conversion of PO into 24kDa protein was blocked by heating isolated myelin at 100°C for

Harish C. Agrawal; Daya Agrawal; Arnold W. Strauss

1990-01-01

452

LEACHING OF URANIUM ORES USING ALKALINE CARBONATES AND BICARBONATES AT ATMOSPHERIC PRESSURE  

DOEpatents

A method of leaching uranium ores containing sulfides is described. The method consists of adding a leach solution containing alkaline carbonate and alkaline bicarbonate to the ore to form a slurry, passing the slurry through a series of agitators, passing an oxygen containing gas through the slurry in the last agitator in the series, passing the same gas enriched with carbon dioxide formed by the decomposition of bicarbonates in the slurry through the penultimate agitator and in the same manner passing the same gas increasingly enriched with carbon dioxide through the other agitators in the series. The conditions of agitation is such that the extraction of the uranium content will be substantially complete before the slurry reaches the last agitator.

Thunaes, A.; Brown, E.A.; Rabbits, A.T.; Simard, R.; Herbst, H.J.

1961-07-18

453

Buffered tungsten reference electrode for LWR applications  

SciTech Connect

An alternative reference electrode for electrochemical corrosion potential (ECP) measurements, consisting of tungsten metal in a saturated Ca(OH){sub 2} buffer solution, has been developed and tested under boiling water reactor (BWR) operating conditions as part of the Massachusetts Institute of Technology electric utility program research on coolant technology in support of light water reactor (LWR) operations. All major BWR vendors currently rely on internal Ag/AgCl reference electrodes for in-reactor ECP measurement. Although adequate performance has been achieved in normal water chemistry (NWC), their longevity is hampered by reduction of AgCl in hydrogen concentration. In summary, tungsten buffered by saturated Ca(OH){sub 2} solution appears to be a useful alternative reference electrode for use in LWR coolant. Further tests are planned, including characterization of the electrochemical reactions for this system. Development of a radiation-resistant version is also required.

Hwang, I.S.; Outwater, J.O.; Driscoll, M.J. (Massachusetts Inst. of Technology, Cambridge (United States))

1992-01-01

454

Simple buffers for 3D STORM microscopy  

PubMed Central

3D STORM is one of the leading methods for super-resolution imaging, with resolution down to 10 nm in the lateral direction, and 30–50 nm in the axial direction. However, there is one important requirement to perform this type of imaging: making dye molecules blink. This usually relies on the utilization of complex buffers, containing different chemicals and sensitive enzymatic systems, limiting the reproducibility of the method. We report here that the commercial mounting medium Vectashield can be used for STORM of Alexa-647, and yields images comparable or superior to those obtained with more complex buffers, especially for 3D imaging. We expect that this advance will promote the versatile utilization of 3D STORM by removing one of its entry barriers, as well as provide a more reproducible way to compare optical setups and data processing algorithms.

Olivier, Nicolas; Keller, Debora; Rajan, Vinoth Sundar; Gonczy, Pierre; Manley, Suliana

2013-01-01

455

Simple buffers for 3D STORM microscopy.  

PubMed

3D STORM is one of the leading methods for super-resolution imaging, with resolution down to 10 nm in the lateral direction, and 30-50 nm in the axial direction. However, there is one important requirement to perform this type of imaging: making dye molecules blink. This usually relies on the utilization of complex buffers, containing different chemicals and sensitive enzymatic systems, limiting the reproducibility of the method. We report here that the commercial mounting medium Vectashield can be used for STORM of Alexa-647, and yields images comparable or superior to those obtained with more complex buffers, especially for 3D imaging. We expect that this advance will promote the versatile utilization of 3D STORM by removing one of its entry barriers, as well as provide a more reproducible way to compare optical setups and data processing algorithms. PMID:23761850

Olivier, Nicolas; Keller, Debora; Rajan, Vinoth Sundar; Gönczy, Pierre; Manley, Suliana

2013-05-14

456

Bicarbonate dosing: a tool to performance recovery of a thermophilic methanol-fed UASB reactor  

Microsoft Academic Search

The thermophilic-anaerobic treatment of methanol-containing wastewater in an upflow anaerobic sludge blanket (UASB) reactor, was found to be quite sensitive to pH shocks, both acid and alkaline. The results of the recovery experiments of sludge exposed to an alkaline shock, indicated that the addition or deprivation of sodium bicarbonate (NaHCO3) in the medium, plays an important role in the competition

P. L. Paulo; Lier van J. B; G. Lettinga

2003-01-01

457

Chemical composition of xylem sap of tomato grown on bicarbonate containing medium  

Microsoft Academic Search

Incorporation of bicarbonate (HCO3 ) by the roots of tomato seedlings resulted in an increase in biomass production and changed the chemical composition of xylem sap. In the xylem sap of seedlings grown on a medium enriched with HCO3 (5.68 mM dm, series II) compared with the control (series I) the element content increased by about 27% and 33% for

J. Bialczyk; Z. Lechowsk

1995-01-01

458

Modulation of Chloride Secretion in the Rat Ileum by Intracellular Bicarbonate  

Microsoft Academic Search

Increasing intracellular bicarbonate concentration ([HCO3?]i) inhibits calcium-mediated Cl? secretion in rat distal colon and T84 cells. We investigated the effect of [HCO3?]i on Cl? secretion in rat ileum. Segments of intact ileum from Sprague–Dawley rats were studied in Ussing chambers and villus and crypt intracellular pH and [HCO3?]i were determined using BCECF. A range of crypt and villus [HCO3?]i from

Pierre C Dagher; Harminder Chawla; Jeffrey Michael; Richard W Egnor; Alan N Charney

1997-01-01

459

Effects of sodium bicarbonate ingestion on swim performance in youth athletes  

Microsoft Academic Search

The purpose of this study was to evaluate the effect of oral administration of sodium bicarbonate (300 mg·kg-1 b.w.) on swim performance in competitive, (training experience of 6.6±0.6 years) youth, (15.1±0.6 years) male swimmers. The subjects completed a test trial, in a double blind fashion, on separate days, consisting of 4 x 50m front crawl swims with a 1 minute

Adam Zajac; Jaroslaw Cholewa; Stanislaw Poprzecki

460

Kinetics of bicarbonate and chloride transport in human red cell membranes  

Microsoft Academic Search

Unidirectional (t4C)HCO; and ~CI- efflux from human red cells and ghosts was studied under self-exchange conditions at pH 7.8 and 0°C by means of the Millipore-Swinnex filtering technique. Control bicarbonate experiments showed that ~4CO~ loss from the cells to the efflux medium was insignificant. The anion flux was determined under (a) symmetric variations of the anion concentration (C ~i) --

PEDER K. GASBJERG; JESPER BRAHM

1991-01-01

461

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

462

CO2 consumption and bicarbonate fluxes by chemical weathering in North America  

Microsoft Academic Search

Cations released by chemical weathering are mainly counterbalanced by atmospheric\\/soil CO2 dissolved in water. Existing approaches to quantify CO2 consumption by chemical weathering are mostly based on the parameters runoff and lithology. Land cover is not implemented as predictor in existing regional or global scale models for atmospheric\\/soil CO2 consumption. Here, bicarbonate fluxes in North American rivers are quantified by

Nils Jansen; Jens Hartmann; Ronny Lauerwald

2010-01-01

463

A sodium bicarbonate-acid powered blow-gun syringe for remote injection of wildlife.  

PubMed

An automatic blow-gun syringe which uses carbon dioxide gas as the injecting force is described. Upon striking the animal, carbon dioxide gas is released by the chemical combination of sodium bicarbonate (baking soda) and acid (vinegar), within the blow-gun syringe. The syringe has been used successfully with captive collared peccaries (Dicotyles tajacu). It has the advantages of longer stability, dependable gas expansion, reduction of drug loss, and consistent drug injection. PMID:6302330

Lochmiller, R L; Grant, W E

1983-01-01

464

Bicarbonate therapy improves growth in children with incomplete distal renal tubular acidosis  

Microsoft Academic Search

Incomplete distal renal tubular acidosis (idRTA) has recently been associated with osteoporosis and growth retardation, attributed\\u000a to the mild persistent metabolic acidosis. We hypothesized a therapeutic benefit from bicarbonate therapy on growth parameters\\u000a in children with idRTA. In a study group of 40 surgically treated patients with posterior urethral valve (PUV) and normal\\u000a estimated glomerular filtration rate, we evaluated the

Ajay P. Sharma; Ram N. Singh; Connie Yang; Raj K. Sharma; Rakesh Kapoor; Guido Filler

2009-01-01

465

Combination of Kluyveromyces marxianus and sodium bicarbonate for controlling green mold of citrus fruit  

Microsoft Academic Search

Biocontrol efficacy of an antagonistic yeast Kluyveromyces marxianus was evaluated individually or in combination with sodium bicarbonate (SBC) against green mold of citrus fruit caused by Penicillium digitatum. Their effects on postharvest quality of citrus fruit were also investigated. The results indicated that the antagonistic activity of K. marxianus at 1×108CFU\\/mL on green mold of citrus fruit was enhanced by

Peng Geng; Shaohua Chen; Meiying Hu; Muhammad Rizwan-ul-Haq; Kaiping Lai; Fei Qu; Yanbo Zhang

2011-01-01

466

Integrated control of gray mould on apple using Bacillus spp. in combination with sodium bicarbonate  

Microsoft Academic Search

Bacillus subtilis isolates B2, B6 andBacillus brevis isolate EN63-1 were evaluated for control of apple gray mould caused byBotrytis mail isolate 20JR. These isolates were evaluated alone, or in combination with sodium bicarbonate on artificially inoculated Golden\\u000a Delicious apple cultivar. Treated fruit were stored at 4 and 20 °C for 30 and 14 days respectively. When applied alone, all\\u000a isolates

Mohammad Jamalizadeh; Hasan Reza Etebarian; Heshmatolah Aminian; Ali Alizadeh

2009-01-01

467

Reversal of flecainide-induced ventricular arrhythmia by hypertonic sodium bicarbonate in dogs  

Microsoft Academic Search

Flecainide occasionally produces incessant ventricular tachycardia that is difficult to treat. Reports of uncontrolled clinical studies have suggested a therapeutic role for hypertonic sodium bicarbonate (NaHCO3). To test this observation, spontaneous and pacing-induced arrhythmia canine models were designed. In the spontaneous model, flecainide was infused at 0.5 mg\\/kg\\/min until ventricular tachycardia occurred spontaneously. In the pacing-induced model, flecainide was infused

David M Salerno; Maryann M Murakami; Roland B Johnston; Daniel E Keyler; Paul R Pentel

1995-01-01

468

The bicarbonate effect, oxygen evolution, and the shadow of Otto Warburg  

Microsoft Academic Search

A short list of the twentieth century's dominant figures in photosynthesis would unquestionably include Otto Warburg. One\\u000a of his many discoveries, the `bicarbonate effect' remains a lasting puzzle to his heirs in the field. Recent developments\\u000a in this area of research have renewed interest and call for a re-examination of the ideas surrounding this controversial topic.\\u000a Focus here will be

Alan J. Stemler

2002-01-01

469

Effect of oral administration of sodium bicarbonate on surface EMG activity during repeated cycling sprints  

Microsoft Academic Search

The purpose of this study was to determine the effect of oral administration of sodium bicarbonate (NaHCO3) on surface electromyogram (SEMG) activity from the vastus lateralis (VL) during repeated cycling sprints (RCS). Subjects\\u000a performed two RCS tests (ten 10-s sprints) interspersed with both 30-s and 360-s recovery periods 1 h after oral administration\\u000a of either NaHCO3 (RCSAlk) or CaCO3 (RCSPla) in

Ryouta Matsuura; Takuma Arimitsu; Takehide Kimura; Takahiro Yunoki; Tokuo Yano

2007-01-01

470

A method of assessing solid state reactivity illustrated by thermal decomposition experiments on sodium bicarbonate  

Microsoft Academic Search

The thermal decomposition of sodium bicarbonate (NaHCO3) was studied under different atmospheres (dry nitrogen, air, and carbon dioxide), with various heating rates in order to characterize the substance. Various non-isothermal methods of kinetic analysis were employed in estimating the Arrhenius kinetic parameters, the activation energy and the frequency factor. All show that the most probable reaction mechanism under dry nitrogen

Pavan K. Heda; David Dollimore; Kenneth S. Alexander; Dun Chen; Emmeline Law; Paul Bicknell

1995-01-01

471

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

472

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

473

Guanylate cyclase-G, expressed in the Grueneberg ganglion olfactory subsystem, is activated by bicarbonate.  

PubMed

GC (guanylate cyclase)-G is the most recently identified member of the receptor GC family. However, the regulation of its activity and protein expression in the mammalian olfactory system remains unclear. In the present study, we used a GC-G-specific antibody to validate that the GC-G protein is expressed in Grueneberg ganglion neurons, a newly recognized olfactory subsystem co-expressing other cGMP signalling components such as the cGMP-regulated PDE2A (phosphodiesterase 2A) and the cGMP-gated ion channel CNGA3 (cyclic nucleotide-gated cation channel ?-3). Further molecular and biochemical analyses showed that heterologously expressed GC-G protein, specifically the C-terminal cyclase domain, was directly stimulated by bicarbonate in both in vivo cellular cGMP accumulation assays in human embryonic kidney-293T cells and in vitro GC assays with a purified recombinant protein containing the GC domain. In addition, overexpression of GC-G in NG108 neuronal cells resulted in a CO2-dependent increase in cellular cGMP level that could be blocked by treatment with acetazolamide, an inhibitor of carbonic anhydrases, which implies that the stimulatory effect of CO2 requires its conversion to bicarbonate. Together, our data demonstrate a novel CO2/bicarbonate-dependent activation mechanism for GC-G and suggest that GC-G may be involved in a wide variety of CO2/bicarbonate-regulated biological processes such as the chemosensory function in Grueneberg ganglion neurons. PMID:20738256

Chao, Ying-Chi; Cheng, Chien-Jui; Hsieh, Hsiu-Ting; Lin, Chih-Ching; Chen, Chien-Chang; Yang, Ruey-Bing

2010-12-01

474

A Sodium Bicarbonate Dosing Methodology for pH Management in Freshwater-Recirculating Aquaculture Systems  

Microsoft Academic Search

High-density water-recirculating aquaculture systems with hydraulic retention times above about 5 d must be monitored for alkalinity, and in the vast majority of cases, the alkalinity must be adjusted upwards to assure maintenance of desirable pH levels. Sodium bicarbonate is the preferred additive for increasing alkalinity because it is inexpensive, dissolves rapidly, and is safe for both personnel and fish.

J. Clay Loyless; Ronald F. Malone

1997-01-01

475

Acute and chronic loading of sodium bicarbonate in highly trained swimmers  

Microsoft Academic Search

In the present study, 200-m swim time in highly trained male swimmers was measured on two consecutive days (Trial 1 and Trial\\u000a 2) and under three conditions [(1) acute loading, AcL; (2) chronic loading, ChL; (3) Placebo, PLA]. No sodium bicarbonate (NaHCO3) was administered between Trial 1 and Trial 2 under each condition. Blood lactate concentration ([La?]), base excess of

Sarah Joyce; Clare Minahan; Megan Anderson; Mark Osborne

476

pH and salivary sodium bicarbonate in cancer patients: Correlation with seric concentration  

Microsoft Academic Search

Objective: To determine the correlation between pH and bicarbonate of soda in blood and saliva in child and adoles- cent patients during the administration of 3g\\/m2 of methotrexate. Method: A controlled clinical test was performed on 23 patients diagnosed with Acute Lymphoblastic Leukemia. Ages ranged from 4 to 18. The Spearman Correlation Coefficient was used to interpret the data. Results:

Thais Rojas-Morales; Rita Navas; Ninoska Viera; Carmen Julia Álvarez; Neira Chaparro

477

Efficient cellulose solvent: quaternary ammonium chlorides.  

PubMed

Pure quaternary tetraalkylammonium chlorides with one long alkyl chain dissolved in various organic solvents constitute a new class of cellulose solvents. The electrolytes are prepared in high yields and purity by Menshutkin quaternization, an inexpensive and easy synthesis route. The pure molten tetraalkylammonium chlorides dissolve up to 15 wt% of cellulose. Cosolvents, including N,N-dimethylacetamide (DMA), may be added in large excess, leading to a system of decreased viscosity. Contrary to the well-established solvent DMA/LiCl, cellulose dissolves in DMA/quaternary ammonium chlorides without any pretreatment. Thus, the use of the new solvent avoids some disadvantages of DMA/LiCl and ionic liquids, the most extensively employed solvents for homogeneous cellulose chemistry. PMID:24014114

Kostag, Marc; Liebert, Tim; El Seoud, Omar A; Heinze, Thomas

2013-09-09

478

Antifungal activity of gemini quaternary ammonium salts.  

PubMed

A series of gemini quaternary ammonium chlorides and bromides with various alkyl chain and spacer lengths was synthesized. The most active compounds against fungi were chlorides with 10 carbon atoms within the hydrophobic chain. Among these compounds were few with no hemolytic activity at minimal inhibitory concentrations. None of the tested compounds were cytotoxic and mutagenic. Cationic gemini surfactants poorly reduced the adhesion of microorganisms to the polystyrene plate, but inhibited the filamentation of Candida albicans. One of the tested compounds eradicated C. albicans and Rodotorula mucilaginosa biofilm, what could be important in overcoming catheter-associated infections. It was also shown that gemini surfactants enhanced the sensitivity of C. albicans to azoles and polyenes, thus they might be potentially used in combined therapy against fungi. PMID:23827647

Ob??k, Ewa; Piecuch, Agata; Krasowska, Anna; Luczy?ski, Jacek

2013-07-01

479

Wintering bird response to fall mowing of herbaceous buffers  

USGS Publications Warehouse

Herbaceous buffers are strips of herbaceous vegetation planted between working agricultural land and streams or wetlands. Mowing is a common maintenance practice to control woody plants and noxious weeds in herbaceous buffers. Buffers enrolled in Maryland's Conservation Reserve Enhancement Program (CREP) cannot be mowed during the primary bird nesting season between 15 April and 15 August. Most mowing of buffers in Maryland occurs in late summer or fall, leaving the vegetation short until the following spring. We studied the response of wintering birds to fall mowing of buffers. We mowed one section to 10-15 cm in 13 buffers and kept another section unmowed. Ninety-two percent of birds detected in buffers were grassland or scrub-shrub species, and 98% of all birds detected were in unmowed buffers. Total bird abundance, species richness, and total avian conservation value were significantly greater in unmowed buffers, and Savannah Sparrows (Passerculus sandwichensis), Song Sparrows (Melospiza melodia), and White-throated Sparrows (Zonotrichia albicollis) were significantly more abundant in unmowed buffers. Wintering bird use of mowed buffers was less than in unmowed buffers. Leaving herbaceous buffers unmowed through winter will likely provide better habitat for wintering birds. ?? 2011 by the Wilson Ornithological Society.

Blank, P. J.; Parks, J. R.; Dively, G. P.

2011-01-01

480

Smooth Nb surfaces fabricated by buffered electropolishing  

Microsoft Academic Search

It was demonstrated that smooth Nb surfaces could be obtained through buffered electropolishing (BEP) employing an electrolyte consisting of lactic, sulfuric, and hydrofluoric acids. Parameters that control the polishing process were optimized to achieve a smooth surface finish. The polishing rate of BEP was determined to be 0.646?m\\/min which was much higher than 0.381?m\\/min achieved by the conventional electropolishing (EP)

Andy T. Wu; John Mammosser; Larry Phillips; Jean Delayen; Charles Reece; Amy Wilkerson; David Smith; Robert Ike

2007-01-01