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1

21 CFR 184.1135 - Ammonium bicarbonate.  

Code of Federal Regulations, 2011 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...

2011-04-01

2

21 CFR 184.1135 - Ammonium bicarbonate.  

...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...

2014-04-01

3

Sodium bicarbonate and Alkaten as buffers in beef cattle diets  

E-print Network

SODIUM BICARBONATE AND ALKATEN AS BUFFERS IN BEEF CATTLE DIETS A Thesis by BENED ICT JOSEP H BOERNER Submitted to the Graduate College of Texas A8M University im partial fulfillment of the requirements for the degree of MASTER OF SC IENCE... August 1985 Major Subject: Nutrition SODIUM BICARBONATE AND ALKATEN AS BUFFERS IN BEEF CATTLE DIETS A thesis by BENEDICT JOSEPH BOERNER Approved as to style and content by: Flo M. Byers (Chairma of Committee) ~r( Gerald T. Schelling (Member...

Boerner, Benedict Joseph

2012-06-07

4

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

5

Toward an In Vivo Dissolution Methodology: A Comparison of Phosphate and Bicarbonate Buffers  

PubMed Central

Purpose To evaluate the difference between the pharmaceutical phosphate buffers and the gastrointestinal bicarbonates in dissolution of ketoprofen and indomethacin, to illustrate the dependence of buffer differential on biopharmaceutical properties of BCS II weak acids, and to recommend phosphate buffers equivalent to bicarbonates. Methods The intrinsic dissolution rates of, ketoprofen and indomethacin, were experimentally measured using rotating disk method at 37°C in USP SIF/FaSSIF and various concentrations of bicarbonates. Theoretical models including an improved reaction plane model and a film model were applied to estimate the surrogate phosphate buffers equivalent to the bicarbonates. Results Experimental results show that the intrinsic dissolution rates of ketoprofen and indomethacin, in USP and FaSSIF phosphate buffers are 1.5–3.0 times of that in the 15 mM bicarbonates. Theoretical analysis demonstrates that the buffer differential is largely dependent on the drug pKa and secondly on solubility, and weakly dependent on the drug diffusivity. Further, in accordance with the drug pKa, solubility and diffusivity, simple phosphate surrogate was proposed to match an average bicarbonate value (15 mM) of the upper gastrointestinal region. Specifically, phosphate buffers of 13–15 mM and 3–4 mM were recommended for ketoprofen and indomethacin, respectively. For both ketoprofen and indomethacin, the intrinsic dissolution using the phosphate surrogate buffers closely approximated the 15 mM bicarbonate buffer. Conclusions This work demonstrates the substantial difference between pharmaceutical phosphates and physiological bicarbonates in determining the drug intrinsic dissolution rates of BCS II weak acids, such as ketoprofen and indomethacin. Surrogate phosphates were recommended in order to closely reflect the in vivo dissolution of ketoprofen and indomethacin in gastrointestinal bicarbonates, which has significant implications for defining buffer systems for BCS II weak acids in developing in vitro bioequivalence dissolution methodology. PMID:19183104

Sheng, Jennifer J.; McNamara, Daniel P.; Amidon, Gordon L.

2011-01-01

6

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

E-print Network

Author's personal copy Evaluation of stainless steel cathodes and a bicarbonate buffer for hydrogen: Biohydrogen Bioenergy Gas bag Buffer Electrohydrogenesis a b s t r a c t Microbial electrolysis cells (MECs) are often examined for hydrogen production using non- sustainable phosphate buffered solutions (PBS

7

Bicarbonate/lactate- and bicarbonate-buffered peritoneal dialysis fluids improve ex vivo peritoneal macrophage TNFalpha secretion.  

PubMed

Peritoneal macrophage (PMO) function was examined ex vivo after their in vivo exposure to either acidic, lactate-buffered solutions (PD4; 40 mM lactate, pH 5.2), bicarbonate/lactate-buffered solution (TBL; 25 mM/15 mM bicarbonate/lactate, pH 7.3), or bicarbonate-buffered solution (TB; 38 mM bicarbonate, pH 7.3), containing either 1.36 or 3.86% glucose. Initial experiments demonstrated that tumor necrosis factor-alpha (TNFalpha) release (assessed by TNF-direct immunoassay [DIA]) from PMO isolated from the peritoneal cavities of patients exposed to conventional fluid (PD4 1.36% glucose) was lowest after 30 min of intraperitoneal dwell (3591+/-1200 versus 28,946+/-9359 for 240-min dwell [pg/ml], n=5, P < 0.05). Five patients were exposed on 3 successive days to PD4, TBL, and TB for 30-min acute dwells containing 1.36% glucose in the first week and 3.86% glucose during the second. PMO TNFalpha release was assessed after ex vitro exposure to lipopolysaccharide (LPS). Exposure of PMO to TBL or TB (1.36% glucose) resulted in a significant increase in the generation of TNFalpha (pg/2 X 10(6) PMO) compared with PD4. TBL: 68,659+/-35,633, TB: 53,682+/-26,536 versus PD4 17,107+/-8996 (LPS 1.0 ng/ml, n=5 patients, P=0.043 versus PD4 for both). PMO that were recovered from PD4 and TB dwells (3.86% glucose) showed no significant difference in TNFalpha secretion (21,661+/-6934 and 23,923+/-9147, respectively). In contrast, exposure to TBL resulted in a significant increase (41,846+/-11,471) compared with PD4 (LPS 1.0 ng/ml, n=5 patients, P=0.043). These data demonstrate enhanced PMO function after in vivo exposure to bicarbonate- and bicarbonate/lactate-buffered solutions. This response was sustained in TBL alone at the highest glucose concentrations. These results suggest that the newer solutions, and particularly bicarbonate/lactate, might improve host defense status in peritoneal dialysis patients. PMID:9697673

MacKenzie, R K; Holmes, C J; Moseley, A; Jenkins, J P; Williams, J D; Coles, G A; Faict, D; Topley, N

1998-08-01

8

Ammonium bicarbonate as a replacement for carbon dioxide in Transgrow bottles for primary isolation of Neisseria gonorrhoeae.  

PubMed Central

Transgrow bottles with medium containing ammonium bicarbonate and Transgrow bottles gassed with 10% carbon dioxide performed equally well in detecting Neisseria gonorrhoeae in 434 clinical specimens. It appears that incorporation of ammonium bicarbonate into the medium increased the efficiency of the manufacturing process while maintaining the effectiveness of the medium. PMID:6417163

Potter, L D; Lewis, J S; Wentworth, B B; Larsen, E H

1983-01-01

9

In vivo exposure to bicarbonate/lactate- and bicarbonate-buffered peritoneal dialysis fluids improves ex vivo peritoneal macrophage function.  

PubMed

The impact on peritoneal macrophage (PMO) function of acidic lactate-buffered (Lac-PDF [PD4]; 40 mmol/L of lactate; pH 5.2) and neutral-pH, bicarbonate-buffered (TB; 38 mmol/L of bicarbonate; pH 7. 3) and bicarbonate/lactate-buffered (TBL; 25 mmol/L of bicarbonate/15 mmol/L of lactate; pH 7.3) peritoneal dialysis fluids (PDFs) was compared during a study of continuous therapy with PD4, TB, or TBL. During a run-in phase of 6 weeks when all patients (n = 15) were treated with their regular dialysis regimen with Lac-PDF, median PMO tumor necrosis factor alpha (TNFalpha) release values were 203.6, 89.9, and 115.5 pg TNFalpha/10(6) PMO in the patients subsequently randomized to the PD4, TB, and TBL treatment groups, respectively. Median stimulated TNFalpha values (serum-treated zymosan [STZ], 10 microgram/mL) were 1,894.6, 567.3, and 554.5 pg TNFalpha/10(6) PMO in the same groups, respectively. During the trial phase of 12 weeks, when the three groups of patients (n = 5 per group) were randomized to continuous treatment with PD4, TB, or TBL, median constitutive TNFalpha release values were 204.7, 131.4, and 155.4 pg TNFalpha/10(6) PMO, respectively. Stimulated TNFalpha values (STZ, 10 microgram/mL) were 1,911, 1,832, and 1,378 pg TNFalpha/10(6) PMO in the same groups, respectively. Repeated-measures analysis of variance comparing the run-in phase with the trial phase showed that PMO TNFalpha release was significantly elevated in patients treated with both TB (P = 0.040) and TBL (P = 0.014) but not in patients treated with Lac-PDF (P = 0. 795). These data suggest that patients continuously exposed to bicarbonate- and bicarbonate/lactate-buffered PDFs might have better preserved PMO function and thus improved host defense status. PMID:10620552

Mackenzie, R K; Jones, S; Moseley, A; Holmes, C J; Argyle, R; Williams, J D; Coles, G A; Pu, K; Faict, D; Topley, N

2000-01-01

10

Biocompatibility and tolerability of a purely bicarbonate-buffered peritoneal dialysis solution  

Microsoft Academic Search

BACKGROUND: Novel peritoneal dialysis solutions are characterized by a minimal content of glucose degradation products and a neutral pH. Many studies have shown the biocompatibility of neutral lactate-buffered solutions; however, until now, the effect of purely bicarbonate-buffered solutions has not been intensively studied in vivo. METHODS: This study was an open label, prospective, crossover multicenter trial to investigate the biocompatibility

L. Weiss; B. Stegmayr; G. Malmsten; M. Tejde; H. Hadimeri; C. E. Siegert; J. Ahlmen; R. Larsson; B. Ingman; O. Simonsen; H. W. van Hamersvelt; A. C. Johansson; B. Hylander; M. Mayr; P. H. Nilsson; P. O. Andersson; T. De Los Rios

2009-01-01

11

Manganese-dependent disproportionation of hydrogen peroxide in bicarbonate buffer.  

PubMed

At physiological concentrations of HCO3- and CO2, Mn(II) catalyzes disproportionation of H2O2. This catalase-like activity is directly proportional to the concentrations of Mn(II) and H2O2, and it increases exponentially with increases in pH. The effect of increasing pH is almost completely attributable to the concomitant increase in HCO3- concentration. The rate is proportional to the third power of the HCO3- concentration, suggesting that 3 equivalents of HCO3- combine with 1 equivalent of Mn(II) to form the catalytic complex. It is presumed that the redox potential of the Mn(II) in equilibrium with Mn(III) couple in such a complex permits H2O2 to carry out facile reactions with Mn(II) comparable to those that occur with Fe(III) and Cu(II) chelate complexes, in which OH. and O2-. are established intermediates. The Mn-catalyzed disproportionation of H2O2 does not occur at physiological pH in the absence of HCO3-. Hepes, inorganic phosphate, and inorganic pyrophosphate inhibit the reaction catalyzed by the Mn/HCO3- system. These results are similar to those of Sychev et al. [Sychev, A.Y., Pfannmeller, U. & Isak, V.G. (1983) Russ. J. Phys. Chem. 57, 1690-1693]. The catalase-like activity of Mn(II)-bicarbonate complexes reported here, together with the superoxide dismutase activity of Mn complexes demonstrated by Archibald and Fridovich [Archibald, F.S. & Fridovich, I. (1982) Arch. Biochem. Biophys. 214, 452-463], strengthen the proposition that Mn may play an important role in the protection of cells against oxygen radical-mediated damage. PMID:2296593

Stadtman, E R; Berlett, B S; Chock, P B

1990-01-01

12

In Vivo Predictive Dissolution: Transport Analysis of the CO2 , Bicarbonate In Vivo Buffer System.  

PubMed

Development of an oral in vivo predictive dissolution medium for acid drugs with a pKa in the physiological range (e.g., Biopharmaceutics Classification System Class IIa) requires transport analysis of the complex in vivo CO2 /bicarbonate buffering system. In this report, we analyze this buffer system using hydrodynamically defined rotating disk dissolution. Transport analysis of drug flux was predicted using the film model approach of Mooney et al based on equilibrium assumptions as well as accounting for the slow hydration reaction, CO2 + H2 O ? H2 CO3 . The accuracy of the models was compared with experimentally determined results using the rotating disk dissolution of ibuprofen, indomethacin, and ketoprofen. The equilibrium and slow hydration reaction rate models predict significantly different dissolution rates. The experimental results are more accurately predicted by accounting for the slow hydration reaction under a variety of pH and hydrodynamic conditions. Although the complex bicarbonate buffering system requires further consideration given its dynamic nature in vivo, a simplifying irreversible reaction (IRR) transport analysis accurately predicts in vitro rotating disk dissolution rates of several carboxylic acid drugs. This IRR transport model provides further insight into bicarbonate buffer and can be useful in developing more physiologically relevant buffer systems for dissolution testing. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3473-3490, 2014. PMID:25212721

Krieg, Brian J; Taghavi, Seyed Mohammad; Amidon, Gordon L; Amidon, Gregory E

2014-11-01

13

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

14

In vitro effects of bicarbonate and bicarbonate-lactate buffered peritoneal dialysis solutions on mesothelial and neutrophil function.  

PubMed

The inclusion of bicarbonate in the formulation of peritoneal dialysis solutions may avoid the in vitro impairment of certain cell functions seen with acidic lactate-based fluids. The supranormal physiological levels of HCO3- and PCO2 inherent in such formulations may, however, not be biocompatible. This study compared the in vitro biocompatibility of a pH 5.2 lactate-based formulation with formulations containing either 40 mM lactate at pH 7.4, 38 mM HCO3- at pH 6.8 (PCO2 at approximately 240 mm Hg) or 7.4 (PCO2 at approximately 60 mm Hg), and 25 mM HCO3- plus 15 mM lactate at pH 6.8 (PCO2 at approximately 160 mm Hg) or 7.4 (PCO2 at approximately 40 mm Hg). Significant release of lactate dehydrogenase or decreases in ATP content by human peritoneal mesothelial cells (HPMC) and human peripheral polymorphonuclear leukocytes (PMN) after a 30-min exposure to each test solution was only seen with the pH 5.2 lactate-based fluid. The ATP content of HPMC exposed to this fluid returned to control levels after 30 min of recovery in M199 control medium but showed a trend toward decreasing ATP content at 240 min. Similarly, interleukin (IL)-1 beta-induced IL-6 synthesis by HPMC was also only significantly reduced by the pH 5.2 lactate solution. PMN chemiluminescence was unaffected by 30-min exposure to all test solutions except for the pH 5.2 lactate formulation. Staphylococcus epidermidis phagocytosis was reduced to between 46 to 57% of control with all test solutions except the pH 5.2 lactate solution, which further suppressed the chemiluminescence response to 17% of control. These data suggest that short exposure to supranormal physiological levels of HCO3- and PCO2 does not impair HPMC or PMN viability and function. Furthermore, neutral pH lactate-containing solutions show equivalent biocompatibility to bicarbonate-based ones. PMID:8785390

Topley, N; Kaur, D; Petersen, M M; Jörres, A; Williams, J D; Faict, D; Holmes, C J

1996-02-01

15

The in vitro biocompatibility performance of a 25 mmol\\/L bicarbonate\\/10 mmol\\/L lactate-buffered peritoneal dialysis fluid  

Microsoft Academic Search

The in vitro biocompatibility performance of a 25 mmol\\/L bicarbonate\\/10 mmol\\/L lactate-buffered peritoneal dialysis fluid.Background. The biocompatibility profile of a new peritoneal dialysis (PD) solution (Physioneal 35) was determined using a selection of in vitro assay systems. Physioneal 35 is buffered by a combination of 25 mmol\\/L bicarbonate and 10 mmol\\/L lactate, thereby providing a solution with a total of

LINE SKOUFOS; NICHOLAS TOPLEY; LAURINDA COOKER; ANNE DAWNAY; David J. Millar; Clifford J. Holmes; DIRK FAICT

2003-01-01

16

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. PMID:15485574

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

17

Comparison of hydrogen production and electrical power generation for energy capture in closed-loop ammonium bicarbonate reverse electrodialysis systems.  

PubMed

Currently, there is an enormous amount of energy available from salinity gradients, which could be used for clean hydrogen production. Through the use of a favorable oxygen reduction reaction (ORR) cathode, the projected electrical energy generated by a single pass ammonium bicarbonate reverse electrodialysis (RED) system approached 78 W h m(-3). However, if RED is operated with the less favorable (higher overpotential) hydrogen evolution electrode and hydrogen gas is harvested, the energy recovered increases by as much ~1.5× to 118 W h m(-3). Indirect hydrogen production through coupling an RED stack with an external electrolysis system was only projected to achieve 35 W h m(-3) or ~1/3 of that produced through direct hydrogen generation. PMID:24322796

Hatzell, Marta C; Ivanov, Ivan; Cusick, Roland D; Zhu, Xiuping; Logan, Bruce E

2014-01-28

18

Bicarbonate and other buffer systems can enhance the rate of H+ diffusion through mucus in vitro.  

PubMed

The effect of various diffusible buffers on mucus H+ permeability, and in particular the potency of the HCO3-/CO2 buffer system relative to other selected buffers is reported here. The diffusional resistance of mucus and water was demonstrated to be dependent on buffer concentration, and the contrast between the two types of layer was most pronounced for low DH+ values near neutrality. This concentration dependence was most marked with mucus layers in the buffer systems investigated. Furthermore, the nature and pKa values of the diffusible buffer systems used in this study had a profound effect on measured DH+. The effect was particularly striking in the case of HCO3- buffer with mucus. Possible implications of these in vitro findings in mucosal protection from acid are discussed. PMID:1311604

Desai, M A; Vadgama, P M

1992-03-01

19

Role of bicarbonate as a pH buffer and electron sink in microbial dechlorination of chloroethenes  

PubMed Central

Background Buffering to achieve pH control is crucial for successful trichloroethene (TCE) anaerobic bioremediation. Bicarbonate (HCO3?) is the natural buffer in groundwater and the buffer of choice in the laboratory and at contaminated sites undergoing biological treatment with organohalide respiring microorganisms. However, HCO3? also serves as the electron acceptor for hydrogenotrophic methanogens and hydrogenotrophic homoacetogens, two microbial groups competing with organohalide respirers for hydrogen (H2). We studied the effect of HCO3? as a buffering agent and the effect of HCO3?-consuming reactions in a range of concentrations (2.5-30 mM) with an initial pH of 7.5 in H2-fed TCE reductively dechlorinating communities containing Dehalococcoides, hydrogenotrophic methanogens, and hydrogenotrophic homoacetogens. Results Rate differences in TCE dechlorination were observed as a result of added varying HCO3? concentrations due to H2-fed electrons channeled towards methanogenesis and homoacetogenesis and pH increases (up to 8.7) from biological HCO3? consumption. Significantly faster dechlorination rates were noted at all HCO3? concentrations tested when the pH buffering was improved by providing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) as an additional buffer. Electron balances and quantitative PCR revealed that methanogenesis was the main electron sink when the initial HCO3? concentrations were 2.5 and 5 mM, while homoacetogenesis was the dominant process and sink when 10 and 30 mM HCO3? were provided initially. Conclusions Our study reveals that HCO3? is an important variable for bioremediation of chloroethenes as it has a prominent role as an electron acceptor for methanogenesis and homoacetogenesis. It also illustrates the changes in rates and extent of reductive dechlorination resulting from the combined effect of electron donor competition stimulated by HCO3? and the changes in pH exerted by methanogens and homoacetogens. PMID:22974059

2012-01-01

20

Better preservation of peritoneal morphologic features and defense in rats after long-term exposure to a bicarbonate/lactate-buffered solution.  

PubMed

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 products 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. The omentum, peritoneum, and mesothelial cell layer were screened for morphologic changes. In addition, the bacterial clearing capacity of the peritoneal cells was studied. Significantly more milky spots and blood vessels were observed in the omenta of animals treated with standard solution (P < 0.03 for both parameters). Electron-microscopic analysis demonstrated dramatic changes in the appearance of the vascular endothelial cells of the milky spots and a severely damaged or even absent mesothelium on the peritoneal membrane of the standard solution-treated animals. In contrast, the mesothelium was still present in the bicarbonate/lactate-buffered solution group, although the cells lost microvilli. Both peritoneal dialysis fluids significantly increased the density of mesothelial cells (per square millimeter) on the surface of the liver and the thickness of the submesothelial extracellular matrix of the peritoneum (both P < 0.04 for both fluids versus control). A significantly better ex vivo bacterial clearing capacity was observed with peritoneal cells from the bicarbonate/lactate-buffered solution group, compared with the standard solution group (P < 0.05 in both experiments). These results demonstrate that instillation of bicarbonate/lactate-buffered solution into rats for 9 to 10 wk preserves both morphologic and immune parameters much more effectively, compared with standard solution. These findings may be of considerable clinical importance. PMID:11729248

Hekking, L H; Zareie, M; Driesprong, B A; Faict, D; Welten, A G; de Greeuw, I; Schadee-Eestermans, I L; Havenith, C E; van den Born, J; ter Wee, P M; Beelen, R H

2001-12-01

21

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

PubMed Central

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

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

2013-01-01

22

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. PMID:21897712

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

2011-01-01

23

Shallow ground water nitrate-N and ammonium-N in cropland and riparian buffers  

Microsoft Academic Search

The extent of nutrient reduction in shallow ground water flow between cropland and riparian buffers in the Northeast is not well established, yet there is an increasing need to quantify such reductions. A four-year project was initiated in 2002 to determine the relative effectiveness of riparian buffers on reducing nutrients in soil water and shallow ground water flow from adjacent

Eric O. Young; Russell D. Briggs

2005-01-01

24

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

PubMed

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 approximately 3 is separated from a bicarbonate (25 mmol/L)-lactate (15 mmol/L) buffer during heat sterilization permits PD fluids with lower GDP to be delivered to the patient at neutral pH. To establish the possible benefit of two-chambered bag PD fluids on peripheral blood mononuclear cell (PBMC) and polymorphonuclear (PMN) cell function, we compared conventional 1.5% Dianeal (1.5%D) with 1.5% two-chambered bag bicarbonate-lactate (1.5%D-B), and conventional 4.25% Dianeal (4.25%D) with 4.25% two-chambered bag bicarbonate-lactate (4.25%D-B). Furthermore, to study the effect of the sterilization process on PBMC and PMN function, we compared filter-sterilized 4.25%D (4.25%D-F) with 4.25%D and 4.25%D-B. PBMC were harvested by Ficoll-Hypaque separation, and 2.5 x 10(6) cells in RPMI were incubated with an equal volume of the test fluids for 4 hours, pelleted, and resuspended in RPMI containing 10 ng endotoxin for a further 20 hours. Tumor necrosis factor alpha (TNF-alpha) production by endotoxin-stimulated PBMC was not significantly different (P = 0.10) between 1.5%D-B and 1.5%D, but was significantly higher (P = 0.01) with 4.25%D-B compared with 4.25%D. PBMC exposed to filter-sterilized fluid (4.25%D-F) showed significantly higher endotoxin-stimulated TNF-alpha production compared with 4.25%D (P = 0.02), but was not significantly different from 4.25%D-B (P = 0.40). PMN were harvested by Ficoll-Hypaque separation and 10 x 10(6) cells incubated with test fluids for 30 minutes. After incubation, phagocytosis (phagocytosis index) was determined by the uptake of 14C-labeled Staphylococcus aureus, oxidative burst by reduction of ferricytochrome C to ferrocytochrome C on stimulation with PMA, and enzyme release by measurement of endotoxin-stimulated bactericidal/permeability increasing protein (BPI). Bicarbonate-lactate two-chambered fluids of similar osmolality and glucose concentration conferred a significant improvement in phagocytosis (P = 0.02 for 1.5%D-B and P < 0.001 for 4.25%D-B). Oxidative burst and BPI release were significantly higher in 4.25%D-B compared with 4.25%D (P < 0.001). Filter-sterilized 4.25%D-F conferred a significant improvement in phagocytosis and oxidative burst compared with 4.25%D (P < 0.001) or 4.25%D-B (P < 0.001). Furthermore, conventional 4.25%D was associated with significantly lower BPI release compared with 4.25%D-F (P = 0.01). GDP's acetaldehyde and 5-HMF were analyzed in 4.25%D-B, 4.25%D, and 4.25%D-F. Acetaldehyde was below the lower limit (0.79 ppm) of the standard curve in 4.25%D-B and 4.25%D-F fluids but was detected (3.76 to 5.12 ppm) in all of the 4.25%D fluids. Relative levels of 5-HMF in the 4.25%D-B (0.032 to 0.041 Abs @ 284 nm) and 4.25%D (0.031 to 0.036 Abs @ 284 nm) were similar. The lowest levels (0.001 Abs @ 284 nm) were observed in the filter-sterilized 4.25%D-F. The beneficial effects of two-chambered bicarbonate lactate-buffered PD fluids on PBMC and PMN function are probably related to reduction of GDP from heat sterilization of glucose in a separate chamber at a lower pH. This improvement in biocompatibility could have a beneficial affect on peritoneal defenses. PMID:9370184

Sundaram, S; Cendoroglo, M; Cooker, L A; Jaber, B L; Faict, D; Holmes, C J; Pereira, B J

1997-11-01

25

Bicarbonate transport in health and disease.  

PubMed

Bicarbonate (HCO3 (-) ) has a central place in human physiology as the waste product of mitochondrial energy production and for its role in pH buffering throughout the body. Because bicarbonate is impermeable to membranes, bicarbonate transport proteins are necessary to enable control of bicarbonate levels across membranes. In humans, 14 bicarbonate transport proteins, members of the SLC4 and SLC26 families, function by differing transport mechanisms. In addition, some anion channels and ZIP metal transporters contribute to bicarbonate movement across membranes. Defective bicarbonate transport leads to diseases, including systemic acidosis, brain dysfunction, kidney stones, and hypertension. Altered expression levels of bicarbonate transporters in patients with breast, colon, and lung cancer suggest an important role of these transporters in cancer. © 2014 IUBMB Life, 66(9):596-615, 2014. PMID:25270914

Alka, Kumari; Casey, Joseph R

2014-09-01

26

Critical role of bicarbonate and bicarbonate transporters in cardiac function.  

PubMed

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

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

2014-08-26

27

Isolation of bicarbonate from equine urine for isotope ratio mass spectrometry  

Microsoft Academic Search

Sodium bicarbonate administration to horses prior to competition in order to enhance the buffer capacity of the organism is considered as a doping offence. The analysis of the isotopic composition of urinary bicarbonate\\/CO2 (TCO2) may help to identify an exogenous bicarbonate source, as technical sodium bicarbonate exhibits elevated ?C values compared with urinary total carbon. The isolation of TCO2 from

Frank Hülsemann; Ulrich Flenker; Marc Machnik; Wilhelm Schänzer

2007-01-01

28

Sodium Bicarbonate Therapy in Patients with Metabolic Acidosis  

PubMed Central

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

Adeva-Andany, Maria M.; Fernandez-Fernandez, Carlos; Mourino-Bayolo, David; Castro-Quintela, Elvira; Dominguez-Montero, Alberto

2014-01-01

29

A Modified o-Phthalaldehyde Fluorometric Analytical Method for Ultratrace Ammonium in Natural Waters Using EDTA-NaOH as Buffer  

PubMed Central

In the existence of appropriate amount of disodium ethylenediaminetetraacetate (EDTA), precipitation would not occur in seawater and other natural waters even if the sample solution was adjusted to strong basicity, and the NH3-OPA-sulfite reaction at the optimal pH range could be used to determine ammonium in natural waters. Based on this, a modified o-phthalaldehyde fluorometric analytical method has been established to determine ultratrace ammonium in natural waters. Experimental parameters, including reagent concentration, pH, reaction time, and effect of EDTA, were optimized throughout the experiments based on univariate experimental design. The results showed that the optimal pH range was between 10.80 and 11.70. EDTA did not obviously affect the fluorometric intensity. The linearity range of the proposed method was 0.032–0.500?µmol/L, 0.250–3.00?µmol/L, and 1.00–20.0?µmol/L at the excitation/emission slit of 3?nm/5?nm, 3?nm/3?nm, and 1.5?nm/1.5?nm, respectively. The method detection limit was 0.0099?µmol/L. Compared to the classical OPA method, the proposed method had the advantage of being more sensitive and could quantify ultratrace ammonium without enrichment.

Hu, Hongzhi; Li, Shuo; Guo, Qing; Wu, Chancui

2014-01-01

30

Sodium bicarbonate: basically useless therapy.  

PubMed

Common clinical practices often are unsupported by experimental evidence. One example is the administration of sodium bicarbonate to neonates. Despite a long history of widespread use, objective evidence that administration of sodium bicarbonate improves outcomes for patients in cardiopulmonary arrest or with metabolic acidosis is lacking. Indeed, there is evidence that this therapy is detrimental. This review examines the history of sodium bicarbonate use in neonatology and the evidence that refutes the clinical practice of administering sodium bicarbonate during cardiopulmonary resuscitation or to treat metabolic acidosis in the NICU. PMID:18829808

Aschner, Judy L; Poland, Ronald L

2008-10-01

31

DIETHANOLAMINE-CARBON DIOXIDE BUFFER PRODUCES ETHYLENE  

EPA Science Inventory

Carbon dioxide concentrates in containers are frequently controlled by using a diethanolamine-bicarbonate buffer. Current studies show that this buffer produces ethylene and that the production increases with increasing pH and/or time in the incubation vessel. Ethylene is not pro...

32

Mis-trafficking of bicarbonate transporters: implications to human diseases.  

PubMed

Bicarbonate is a waste product of mitochondrial respiration and one of the main buffers in the human body. Thus, bicarbonate transporters play an essential role in maintaining acid-base balance but also during fetal development as they ensure tight regulation of cytosolic and extracellular environments. Bicarbonate transporters belong to two gene families, SLC4A and SLC26A. Proteins from these two families are widely expressed, and thus mutations in their genes result in various diseases that affect bones, pancreas, reproduction, brain, kidneys, eyes, heart, thyroid, red blood cells, and lungs. In this minireview, we discuss the current state of knowledge regarding the effect of SLC4A and SLC26A mutants, with a special emphasis on mutants that have been studied in mammalian cell lines and how they correlate with phenotypes observed in mice models. PMID:21455268

Almomani, Ensaf Y; Chu, Carmen Y S; Cordat, Emmanuelle

2011-04-01

33

Buffer Therapy for Cancer  

PubMed Central

Oral administration of pH buffers can reduce the development of spontaneous and experimental metastases in mice, and has been proposed in clinical trials. Effectiveness of buffer therapy is likely to be affected by diet, which could contribute or interfere with the therapeutic alkalinizing effect. Little data on food pH buffering capacity was available. This study evaluated the pH and buffering capacity of different foods to guide prospective trials and test the effect of the same buffer (lysine) at two different ionization states. Food groups were derived from the Harvard Food Frequency Questionnaire. Foods were blended and pH titrated with acid from initial pH values until 4.0 to determine “buffering score”, in mmol H+/pH unit. A “buffering score” was derived as the mEq H+ consumed per serving size to lower from initial to a pH 4.0, the postprandial pH of the distal duodenum. To differentiate buffering effect from any metabolic byproduct effects, we compared the effects of oral lysine buffers prepared at either pH 10.0 or 8.4, which contain 2 and 1 free base amines, respectively. The effect of these on experimental metastases formation in mice following tail vein injection of PC-3M prostate cancer cells were monitored with in vivo bioluminescence. Carbohydrates and dairy products’ buffering score varied between 0.5 and 19. Fruits and vegetables showed a low to zero buffering score. The score of meats varied between 6 and 22. Wine and juices had negative scores. Among supplements, sodium bicarbonate and Tums® had the highest buffering capacities, with scores of 11 and 20 per serving size, respectively. The “de-buffered” lysine had a less pronounced effect of prevention of metastases compared to lysine at pH 10. This study has demonstrated the anti-cancer effects of buffer therapy and suggests foods that can contribute to or compete with this approach to manage cancer. PMID:24371544

Ribeiro, Maria de Lourdes C; Silva, Ariosto S.; Bailey, Kate M.; Kumar, Nagi B.; Sellers, Thomas A.; Gatenby, Robert A.; Ibrahim-Hashim, Arig; Gillies, Robert J.

2013-01-01

34

Transepithelial Bicarbonate Secretion: Lessons from the Pancreas  

PubMed Central

Many cystic fibrosis transmembrane conductance regulator (CFTR)-expressing epithelia secrete bicarbonate (HCO3?)-containing fluids. Recent evidence suggests that defects in epithelial bicarbonate secretion are directly involved in the pathogenesis of cystic fibrosis, in particular by building up hyperviscous mucus in the ductal structures of the lung and pancreas. Pancreatic juice is one of the representative fluids that contain a very high concentration of bicarbonate among bodily fluids that are secreted from CFTR-expressing epithelia. We introduce up-to-date knowledge on the basic principles of transepithelial bicarbonate transport by showing the mechanisms involved in pancreatic bicarbonate secretion. The model of pancreatic bicarbonate secretion described herein may also apply to other exocrine epithelia. As a central regulator of bicarbonate transport at the apical membrane, CFTR plays an essential role in both direct and indirect bicarbonate secretion. The major role of CFTR in bicarbonate secretion would be variable depending on the tissue and cell type. For example, in epithelial cells that produce a low concentration of bicarbonate-containing fluid (up to 80 mm), either CFTR-dependent Cl?/HCO3? exchange or CFTR anion channel with low bicarbonate permeability would be sufficient to generate such fluid. However, in cells that secrete high-bicarbonate-containing fluids, a highly selective CFTR bicarbonate channel activity is required. Therefore, understanding the molecular mechanism of transepithelial bicarbonate transport and the role of CFTR in each specific epithelium will provide therapeutic strategies to recover from epithelial defects induced by hyposecretion of bicarbonate in cystic fibrosis. PMID:23028131

Park, Hyun Woo; Lee, Min Goo

2012-01-01

35

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

Federal Register 2010, 2011, 2012, 2013

...are then combined with the food consumption rate, as extracted...USDA Continuing Survey for Food Intake by Individuals (CSFII) consumption...the toxicological endpoint to determine risk to those consuming foods that have come into...

2012-08-22

36

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

Microsoft Academic Search

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

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

1998-01-01

37

Clinoptilolite: a possible support material for nitrifying biofilms for effective control of ammonium effluent quality?  

PubMed

Ammonium selective natural zeolite clinoptilolite is suggested as a possible support material for nitrifying biofilms to help improve effluent ammonium quality through its high capacity of ammonium removal in the process of ion exchange. This will especially be helpful in cases where the biofilter receives peak or variable loads routinely or occasionally. At the time of peak loads or shocks of ammonium, ion exchange capacity will provide a buffer for the effluent ammonium quality. Data to support this suggestion is presented. PMID:16114618

Inan, H; Beler Baykal, B

2005-01-01

38

[Technical and economic aspects of bicarbonate hemodialysis].  

PubMed

The bicarbonate haemodialysis which is better tolerated by the patient is accompanied by a series of technical and economical problems. The insolubility of bicarbonate in the usual dialysis concentrates demands the production of an additional concentrate which is added to the irrigation solution. Furthermore, the evaporation of CO2 may lead to the change of the composition of the solution. The special production of the concentrates, particular criteria of storage as well as the necessity of additional monitors for the control of the irrigation solution for dialysis leads to an increase of the cost. The devices for the bicarbonate dialysis being sold now are judged and classified in their efficiency. PMID:3114991

Vanholder, R; Ringoir, S

1987-04-01

39

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

40

Native small airways secrete bicarbonate.  

PubMed

Since the discovery of Cl(-) impermeability in cystic fibrosis (CF) and the cloning of the responsible channel, CF pathology has been widely attributed to a defect in epithelial Cl(-) transport. However, loss of bicarbonate (HCO3(-)) transport also plays a major, possibly more critical role in CF pathogenesis. Even though HCO3(-) transport is severely affected in the native pancreas, liver, and intestines in CF, we know very little about HCO3(-) secretion in small airways, the principle site of morbidity in CF. We used a novel, mini-Ussing chamber system to investigate the properties of HCO3(-) transport in native porcine small airways (? 1 mm ?). We assayed HCO3(-) transport across small airway epithelia as reflected by the transepithelial voltage, conductance, and equivalent short-circuit current with bilateral 25-mM HCO3(-) plus 125-mM NaGlu Ringer's solution in the presence of luminal amiloride (10 ?M). Under these conditions, because no major transportable anions other than HCO3(-) were present, we took the equivalent short-circuit current to be a direct measure of active HCO3(-) secretion. Applying selective agonists and inhibitors, we show constitutive HCO3(-) secretion in small airways, which can be stimulated significantly by ?-adrenergic- (cAMP) and purinergic (Ca(2+)) -mediated agonists, independently. These results indicate that two separate components for HCO3(-) secretion, likely via CFTR- and calcium-activated chloride channel-dependent processes, are physiologically regulated for likely roles in mucus clearance and antimicrobial innate defenses of small airways. PMID:24224935

Shamsuddin, A K M; Quinton, Paul M

2014-04-01

41

Buffered Routing Tree Construction under Buffer  

E-print Network

1 Buffered Routing Tree Construction under Buffer Placement Blockages Wei Chen, Massoud Pedram Dept;2 Previous Work Insert buffers into a pre-determined net topology Van Ginneken '90 Insert buffers while generating the net topology (using a set of buffer stations) Two-pin nets: Zhou '99, Jagannathan '00 Multi

Pedram, Massoud

42

Enhancement of cerulenin production by a natural zeolite, an ammonium ion-trapping agent.  

PubMed

Addition of a natural zeolite, a known ammonium ion-trapping agent, to a complex medium resulted in a several fold increase in cerulenin production by Cephalosporium caerulens. In the presence of zeolite, ammonium ion in the medium decreased, while mycelial growth increased to a small extent, and pH values remained constant. Small amounts of ammonium bicarbonate inhibited cerulenin production without affecting mycelial growth and pH values. It is thus assumed that zeolite stimulated cerulenin production by releasing the biosynthesis from the suppression by ammonium ions in C. caerulens. PMID:6292149

Masuma, R; Tanaka, Y; Omura, S

1982-09-01

43

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

PubMed

A randomized, double-blind, cross-over study was undertaken to determine the effects of novel bicarbonate (38 mM) and bicarbonate (25 mM)/lactate (15 mM) containing peritoneal dialysis (PD) solutions on infusion pain in patients who experienced inflow pain with conventional lactate (40 mM) solution. Pain was assessed using a verbal rating scale and the validated McGill Pain Questionnaire (MPQ). Eighteen patients were recruited to the study. Both novel solutions resulted in highly statistically significant reductions in inflow pain compared to the control lactate solution, as assessed with both the verbal rating scale and the MPQ. For all pain variables assessed, the bicarbonate/lactate solution was more effective than the bicarbonate solution in alleviating pain. In conclusion, both solutions reduced the infusion pain experienced with control solution, but the bicarbonate/lactate solution appears to be the most effective. In contrast to the most widespread current treatment, which is the manual injection of sodium bicarbonate, the bicarbonate/lactate solution does not have the associated increased risk of peritonitis. PMID:9551418

Mactier, R A; Sprosen, T S; Gokal, R; Williams, P F; Lindbergh, M; Naik, R B; Wrege, U; Gröntoft, K C; Larsson, R; Berglund, J; Tranaeus, A P; Faict, D

1998-04-01

44

Cholangiocyte anion exchange and biliary bicarbonate excretion  

PubMed Central

Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. The excretion of bicarbonate at both the canaliculi and the bile ducts is an important contributor to the generation of the so-called bile-salt independent flow. Bicarbonate is secreted from hepatocytes and cholangiocytes through parallel mechanisms which involve chloride efflux through activation of Cl- channels, and further bicarbonate secretion via AE2/SLC4A2-mediated Cl-/HCO3- exchange. Glucagon and secretin are two relevant hormones which seem to act very similarly in their target cells (hepatocytes for the former and cholangiocytes for the latter). These hormones interact with their specific G protein-coupled receptors, causing increases in intracellular levels of cAMP and activation of cAMP-dependent Cl- and HCO3- secretory mechanisms. Both hepatocytes and cholangiocytes appear to have cAMP-responsive intracellular vesicles in which AE2/SLC4A2 colocalizes with cell specific Cl- channels (CFTR in cholangiocytes and not yet determined in hepatocytes) and aquaporins (AQP8 in hepatocytes and AQP1 in cholangiocytes). cAMP-induced coordinated trafficking of these vesicles to either canalicular or cholangiocyte lumenal membranes and further exocytosis results in increased osmotic forces and passive movement of water with net bicarbonate-rich hydrocholeresis. PMID:16773707

Banales, Jesús M; Prieto, Jesús; Medina, Juan F

2006-01-01

45

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

46

BUFFER OVERFLOW -Eswar Balasubramanian  

E-print Network

BUFFER OVERFLOW -Eswar Balasubramanian ECE578 #12;Precursor How serious is this BO? n Number the stack n Exploit n Prevention #12;Buffer Overflow n Copying more data into a buffer than it could hold and ebp adjusted accordingly /* vulnerable.c */ int main() { char buffer[500]; gets(buffer); return 0

47

Seawater bicarbonate removal during hydrothermal circulation  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

48

Electrofocusing in Buffers.  

National Technical Information Service (NTIS)

Methods of electrofocusing in amphoteric or non-amphoteric buffers is disclosed. In such methods, buffers are employed as carrier constituents, and optionally as anolyte and catholyte. Using a buffer electrofocusing system, stability with time has been ac...

A. Chrambach, N. Y. Nguyen

1977-01-01

49

Effects of Bicarbonate\\/Lactate Dialysis Solution on the Inflammatory Response of Spontaneous Peritonitis in Rats Undergoing Chronic Peritoneal Dialysis  

Microsoft Academic Search

Background: We evaluated the incidence of spontaneous peritonitis as well as the local inflammatory response and macroscopic changes in the peritoneum during the use of a bicarbonate\\/lactate-buffered (P) solution in comparison to conventional (D) solutions in rats on chronic peritoneal dialysis. Methods: Sixty-three male Wistar rats were implanted with peritoneal catheters. After 7 days, the animals were randomly divided into

Krzysztof Pawlaczyk; Clifford J. Holmes; Stanislaw Czekalski; Andrzej Breborowicz; Bengt Lindholm

2009-01-01

50

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

51

Bicarbonate-form anion exchange: affinity, regeneration, and stoichiometry.  

PubMed

Magnetic ion exchange (MIEX) is an effective process for removing dissolved organic carbon (DOC) from natural waters, but its implementation has been limited due to production of waste sodium chloride solution (i.e., brine) from the regeneration process. Chloride is of concern because elevated concentrations can have adverse effects on engineered and natural systems. The goal of this research was to explore the efficacy of using anion exchange resin with bicarbonate as the mobile counter ion, which would produce a non-chloride regeneration solution. It was found that bicarbonate-form MIEX resin had a similar affinity as chloride-form MIEX resin for sulfate, nitrate, DOC, and ultraviolet-absorbing substances. Both bicarbonate-form and chloride-form MIEX resins showed the greatest removal efficiencies as fresh resin, and removal efficiency decreased with multiple regeneration cycles. Nevertheless, sodium bicarbonate solution was as effective as sodium chloride solution at regenerating MIEX resin. Regeneration of the bicarbonate-form MIEX resin was illustrated by sparging carbon dioxide gas in a water/resin slurry. This regeneration process would eliminate the need for the addition of salts such as sodium chloride or sodium bicarbonate. The stoichiometry of the bicarbonate-form resin revealed that the bicarbonate was deprotonating within the resin matrix leading to a mixture of both carbonate and bicarbonate mobile counter ions. This work makes an important contribution to ion exchange applications for water treatment by evaluating the affinity, regeneration, and stoichiometry of bicarbonate-form anion exchange. PMID:21056451

Rokicki, Christopher A; Boyer, Treavor H

2011-01-01

52

Comparison of in vitro AGE formation between standard PD fluid and a novel bicarbonate/lactate formulation.  

PubMed

Peritoneal advanced glycation end-product (AGE) formation may be accelerated by glucose degradation products produced as a consequence of heat sterilization of peritoneal dialysis (PD) fluid. The formation of these degradation products is reduced if the glucose is separated from the buffers during heat sterilization. This pilot study compared in vitro AGE formation in PD fluid (1.36% and 3.86% glucose) heat sterilized in a two-compartment bag (bicarbonate/lactate buffer) with that in a standard, single-compartment bag (lactate buffer, Dianeal). Peritoneal dialysis fluids were incubated with human serum albumin (HSA, 1 g/L), as a model protein, at 37 degrees C for 0, 5, and 20 days. Formation of AGEs was assessed by measuring fluorescence at each time point. Advanced glycation end-product formation was greater in lactate PD fluid compared with bicarbonate/lactate PD fluid of equivalent glucose strength. Advanced glycation end-product formation in the lactate PD fluid containing 1.36% glucose was comparable to that in the bicarbonate/lactate PD fluid containing 3.86% glucose. The rate of increase in fluorescence per day was greater in the first 5 days of incubation than in the subsequent 15 days. These results are compatible with the presence of greater amounts of glucose-degradation products in the standard single-compartment bag resulting in enhanced AGE formation. PMID:10649722

Millar, D J; Holmes, C; Faict, D; Dawnay, A

1998-01-01

53

Synchronous Optical Packet Buffers  

Microsoft Academic Search

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

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

2010-01-01

54

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. PMID:7085880

Buerkert, John; Martin, Daniel; Trigg, David

1982-01-01

55

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

56

Ammonium nitrate explosive systems  

SciTech Connect

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.

Coburn, M.D.; Stinecipher, M.M.

1981-11-17

57

Single Simulation Buffer Optimization  

NASA Astrophysics Data System (ADS)

The performance of manufacturing systems can be adjusted by allocation buffer into the manufacturing system. Buffer will improve the performance of manufacturing systems by improving the utilization of the constraints; yet buffer will also increase the makespan and the work in progress. Due to the complex nature of the systems, buffer allocation is usually difficult to optimize. This paper presents a prediction model of the effect of buffer based on the shifting bottleneck detection and a blocking and starving analysis. The prediction model is used to optimize the buffer allocation using only a single simulation.

Roser, Christoph; Nakano, Masaru; Tanaka, Minoru

58

Molecular Structure of Ammonium ion  

NSDL National Science Digital Library

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

2002-09-10

59

Octafluorocalix[4]pyrrole: a chloride/bicarbonate antiport agent.  

PubMed

meso-Octamethyloctafluorocalixpyrrole, a simple tetrapyrrolic macrocycle, has been shown to function as both a chloride/nitrate and a chloride/bicarbonate antiport agent for lipid bilayer transmembrane anion transport. This is the first example of a synthetic macrocyclic pyrrole-based receptor capable of transmembrane bicarbonate transport. PMID:20163121

Gale, Philip A; Tong, Christine C; Haynes, Cally J E; Adeosun, Olubukunola; Gross, Dustin E; Karnas, Elizabeth; Sedenberg, Elaine M; Quesada, Roberto; Sessler, Jonathan L

2010-03-17

60

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

PubMed Central

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

Burgess, W. Patrick; Walker, Phillip J.

2014-01-01

61

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

62

Buffer strips trap contaminants  

E-print Network

ater Buffer strips trap contaminants Three research and demonstration projects seek to determine ideal width for riparian buffer strips in Midwest. They trap sediment, nutrients and pesticides. That ma kes riparian buffer strips a valuable tool in preventing nonpo int sour ce pollution, according

Nebraska-Lincoln, University of

63

Manganese-catalyzed epoxidations of alkenes in bicarbonate solutions.  

PubMed

This paper describes a method, discovered and refined by parallel screening, for the epoxidation of alkenes. It uses hydrogen peroxide as the terminal oxidant, is promoted by catalytic amounts (1.0-0.1 mol %) of manganese(2+) salts, and must be performed using at least catalytic amounts of bicarbonate buffer. Peroxymonocarbonate, HCO(4)(-), forms in the reaction, but without manganese, minimal epoxidation activity is observed in the solvents used for this research, that is, DMF and (t)BuOH. More than 30 d-block and f-block transition metal salts were screened for epoxidation activity under similar conditions, but the best catalyst found was MnSO(4). EPR studies show that Mn(2+) is initially consumed in the catalytic reaction but is regenerated toward the end of the process when presumably the hydrogen peroxide is spent. A variety of aryl-substituted, cyclic, and trialkyl-substituted alkenes were epoxidized under these conditions using 10 equiv of hydrogen peroxide, but monoalkyl-alkenes were not. To improve the substrate scope, and to increase the efficiency of hydrogen peroxide consumption, 68 diverse compounds were screened to find additives that would enhance the rate of the epoxidation reaction relative to a competing disproportionation of hydrogen peroxide. Successful additives were 6 mol % sodium acetate in the (t)BuOH system and 4 mol % salicylic acid in the DMF system. These additives enhanced the rate of the desired epoxidation reaction by 2-3 times. Reactions performed in the presence of these additives require less hydrogen peroxide and shorter reaction times, and they enhance the yields obtained from less reactive alkene substrates. Possible mechanisms for the reaction are discussed. PMID:12358539

Lane, Benjamin S; Vogt, Matthew; DeRose, Victoria J; Burgess, Kevin

2002-10-01

64

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

Microsoft Academic Search

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

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

1994-01-01

65

Mobility of arsenic in aquifer sediments at Datong Basin, northern China: Effect of bicarbonate and phosphate  

E-print Network

Mobility of arsenic in aquifer sediments at Datong Basin, northern China: Effect of bicarbonate 2012 Available online xxxx Keywords: Arsenic Aquifer sediment Column leaching Phosphate Bicarbonate Datong Basin Effects of phosphate and bicarbonate concentration on mobilization of arsenic in aquifer

Hu, Qinhong "Max"

66

VIRTUAL FRAME BUFFER INTERFACE  

NASA Technical Reports Server (NTRS)

Large image processing systems use multiple frame buffers with differing architectures and vendor supplied user interfaces. This variety of architectures and interfaces creates software development, maintenance, and portability problems for application programs. The Virtual Frame Buffer Interface program makes all frame buffers appear as a generic frame buffer with a specified set of characteristics, allowing programmers to write code which will run unmodified on all supported hardware. The Virtual Frame Buffer Interface converts generic commands to actual device commands. The virtual frame buffer consists of a definition of capabilities and FORTRAN subroutines that are called by application programs. The virtual frame buffer routines may be treated as subroutines, logical functions, or integer functions by the application program. Routines are included that allocate and manage hardware resources such as frame buffers, monitors, video switches, trackballs, tablets and joysticks; access image memory planes; and perform alphanumeric font or text generation. The subroutines for the various "real" frame buffers are in separate VAX/VMS shared libraries allowing modification, correction or enhancement of the virtual interface without affecting application programs. The Virtual Frame Buffer Interface program was developed in FORTRAN 77 for a DEC VAX 11/780 or a DEC VAX 11/750 under VMS 4.X. It supports ADAGE IK3000, DEANZA IP8500, Low Resolution RAMTEK 9460, and High Resolution RAMTEK 9460 Frame Buffers. It has a central memory requirement of approximately 150K. This program was developed in 1985.

Wolfe, T. L.

1994-01-01

67

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

68

An economical new process for incenter bicarbonate dialysate production: comparison with acetate in a large dialysis population.  

PubMed

It is generally agreed that bicarbonate dialysate is preferable to acetate dialysate, but the major limiting factors of high cost and technical difficulty in maintaining its stability for prolonged periods preclude its widespread use. The procedure developed by the authors stabilizes bicarbonate dialysate for up to 4 days, rendering bicarbonate dialysate feasible for routine out-patient use. HCO3 dialysate is produced in our dialysis unit after an initial investment of $10,000.00, at a cost per 4-h treatment of $1.22 at a dialysate flow of 500 cc/min. One hundred fifty-one chronic dialysis patients participated in an 18-week study to evaluate clinical symptomatology when bicarbonate was substituted for acetate as the dialysis base buffer. Evaluation of each dialysis treatment (total of 8,183 treatments) consisted of both subjective and objective criteria (vomiting, angina, cramps, hypotension, and frequency of use of mannitol, hypertonic saline, and nitroglycerine). The patients were unaware of the change in dialysate solutions. There was a significant reduction (p less than 0.001) in the incidence of vomiting, cramps, hypotension, nausea, flushing, and the use of mannitol and hypertonic saline during bicarbonate dialysate treatment compared with acetate dialysate. Shortness of breath, angina, mental confusion, and paresthesias were not statistically changed. Although the method of HCO3 dialysate production is associated with occasional higher bacterial count than currently recommended by AAMI standards, no adverse reactions were observed in patients treated with standard efficiency dialyzers. It is concluded that the process for incenter HCO3 production is safe, economical, and better tolerated than acetate dialysate. PMID:2803052

Oettinger, C W; Oliver, J C

1989-10-01

69

Effect of sodium bicarbonate on rate of passage and degradation of soybean meal in postpartum dairy cows.  

PubMed

Effects of sodium bicarbonate on rate of passage and disappearance of soybean meal from the rumen were determined in a change-over experiment with eight cows. Experimental diets containing 50 or 60% roughage were fed over five 21-day periods with four cows per diet. Sodium bicarbonate at 1.0 and 2.5% (diet dry matter) were changed over in periods 2 and 4, whereas periods 1, 3, and 5 served as control. Rate of passage of soybean meal was measured with chromium-mordanted soybean meal and rate of disappearance by nylon bag technique. Effects of diet were similar for all responses. Response to the two percents of buffer was similar for dry matter intake, milk yield, milk fat, and protein. Percent buffer fed was associated positively with ruminal pH and with disappearance of nitrogen from nylon bags. The 0, 1, and 2.5% of buffer resulted in turnover rates of mordanted soybean meal of 8.22, 9.80, and 10.52%/h, but degradation of protein remained relatively constant at 36.0, 38.4, and 38.2%. The influence of rate of passage on ruminal degradability is discussed. PMID:6308076

Okeke, G C; Buchanan-Smith, J G; Grieve, D G

1983-05-01

70

Organellar calcium buffers.  

PubMed

Ca(2+) is an important intracellular messenger affecting many diverse processes. In eukaryotic cells, Ca(2+) storage is achieved within specific intracellular organelles, especially the endoplasmic/sarcoplasmic reticulum, in which Ca(2+) is buffered by specific proteins known as Ca(2+) buffers. Ca(2+) buffers are a diverse group of proteins, varying in their affinities and capacities for Ca(2+), but they typically also carry out other functions within the cell. The wide range of organelles containing Ca(2+) and the evidence supporting cross-talk between these organelles suggest the existence of a dynamic network of organellar Ca(2+) signaling, mediated by a variety of organellar Ca(2+) buffers. PMID:21421925

Prins, Daniel; Michalak, Marek

2011-03-01

71

Effects of bicarbonate on lithium transport in human red cells  

PubMed Central

Lithium influx into human erythrocytes increased 12-fold, when chloride was replaced with bicarbonate in a 150 mM lithium medium (38 degrees C. pH 7.4). The increase was linearly related to both lithium- and bicarbonate concentration, and was completely eliminated by the amino reagent 4, 4'- diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). DIDS binds to an integral membrane protein (mol wt approximately 10(5) dalton) involved in anion exchange. Inhibition of both anion exchange and of bicarbonate-stimulated lithium influx was linearly related to DIDS binding. 1.1 X 10(6) DIDS molecules per cell caused complete inhibition of both processes. Both Cl- and Li+ can apparently be transported by the anion transport mechanism. The results support our previous proposal that bicarbonate-induced lithium permeability is due to transport of lithium-carbonate ion pairs (LiCO-3). DIDS-sensitive lithium influx had a high activation energy (24 kcal/mol), compatible with transport by the anion exchange mechanism. We have examined how variations of passive lithium permeability, induced by bicarbonate, affect the sodium-driven lithium counter-transport in human erythrocytes. The ability of the counter-transport system to establish a lithium gradient across the membrane decrease linearly with bicarbonate concentration in the medium. The counter-transport system was unaffected by DIDS treatement. At a plasma bicarbonate concentration of 24 mM, two-thirds of the lithium influx is mediated by the bicarbonate-stimulated pathway, and the fraction will increase significantly in metabolic alkalosis. PMID:670928

1978-01-01

72

Responses of Arabidopsis thaliana to bicarbonate-induced iron deficiency  

Microsoft Academic Search

Morpho-physiological and biochemical responses of Arabidopsis thaliana (accession N1438) to bicarbonate-induced iron deficiency were investigated. Plants were grown in cabinet under controlled\\u000a conditions, in a nutrient solution containing 5 ?M Fe, added or not with 10 mM NaHCO3. After 30 days, bicarbonate-treated plants displayed significantly lower biomass, leaf number and leaf surface area as compared\\u000a to control plants, and slight yellowing of their

Najoua Msilini; Houneida Attia; Najoua Bouraoui; Sabah M’rah; Riadh Ksouri; Mokhtar Lachaâl; Zeineb Ouerghi

2009-01-01

73

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

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

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

74

Effects of sodium bicarbonate in canine hemorrhagic shock.  

PubMed

We studied the use of sodium bicarbonate administration in a canine model of hemorrhagic shock to determine its effect on hemodynamics, arterial and venous blood gases, respiratory gases, and blood lactate levels. Thirteen dogs were anesthetized, paralyzed, mechanically ventilated, and hemodynamically monitored. Hypotension was induced and maintained at a mean arterial pressure of 40 to 45 mm Hg using controlled hemorrhage and reinfusion. After 2.5 h of shock, the dogs were randomized into two groups: one group (n = 6) received NaCl infusion; the other (n = 7) received sodium bicarbonate (1 mEq/kg followed by a continuous infusion of 2.5 mEq/kg.h for 2.5 h). CO2 production was increased in the alkali group, but there was no statistically significant difference between groups in any measured hemodynamic, blood gas, or respiratory gas variable. These included heart rate, BP, cardiac output, arterial and venous pH, CO2 production, and bicarbonate levels. Blood lactate levels, however, in the bicarbonate treated animals were significantly (p less than .01) higher than in the group treated with NaCl alone (10.1 +/- 3.2 vs. 5.1 +/- 1.2 mEq/L). These results are similar to the effects of bicarbonate found in other models of lactic acidosis, and suggest that bicarbonate therapy may have limited usefulness in the treatment of lactic acidosis. PMID:2840243

Iberti, T J; Kelly, K M; Gentili, D R; Rosen, M; Katz, D P; Premus, G; Benjamin, E

1988-08-01

75

Manganese(II) Catalyzes the Bicarbonate-Dependent Oxidation of Amino Acids by Hydrogen Peroxide and the Amino Acid-Facilitated Dismutation of Hydrogen Peroxide  

Microsoft Academic Search

In bicarbonate\\/CO_2 buffer, Mn(II) and Fe(II) catalyze the oxidation of amino acids by H_2O_2 and the dismutation of H_2O_2. As the Mn(II)\\/Fe(II) ratio is increased, the yield of carbonyl compounds per mole of leucine oxidized is essentially constant, but the ratio of alpha-ketoisocaproate to isovaleraldehyde formed increases, and the fraction of H_2O_2 converted to O_2 increases. In the absence of

B. S. Berlett; P. B. Chock; M. B. Yim; E. R. Stadtman

1990-01-01

76

Role of calcium signaling in epithelial bicarbonate secretion.  

PubMed

Transepithelial bicarbonate secretion plays a key role in the maintenance of fluid and protein secretion from epithelial cells and the protection of the epithelial cell surface from various pathogens. Epithelial bicarbonate secretion is mainly under the control of cAMP and calcium signaling. While the physiological roles and molecular mechanisms of cAMP-induced bicarbonate secretion are relatively well defined, those induced by calcium signaling remain poorly understood in most epithelia. The present review summarizes the current status of knowledge on the role of calcium signaling in epithelial bicarbonate secretion. Specifically, this review introduces how cytosolic calcium signaling can increase bicarbonate secretion by regulating membrane transport proteins and how it synergizes with cAMP-induced mechanisms in epithelial cells. In addition, tissue-specific variations in the pancreas, salivary glands, intestines, bile ducts, and airways are discussed. We hope that the present report will stimulate further research into this important topic. These studies will provide the basis for future medicines for a wide spectrum of epithelial disorders including cystic fibrosis, Sjögren's syndrome, and chronic pancreatitis. PMID:24598807

Jung, Jinsei; Lee, Min Goo

2014-06-01

77

Hydrothermal synthesis of ammonium illite  

USGS Publications Warehouse

Synthetic gel and glass of illitic composition, natural kaolinite, and mixed-layer illite-smectite were used as starting materials for hydrothermal synthesis of ammonium illite. Ammonium illite was prepared from synthetic gel by hydrothermal treatment at 300??C. The onset of crystallization began within 3 h, and well-crystallized ammonium illite appeared at 24 h. Increasing reaction time (up to four weeks) led to many illite layers per crystal. In the presence of equivalent proportions of potassium and ammonium, the gel was transformed to illite with equimolar contents of K and NH4. In contrast, synthesis using glass under the same conditions resulted in a mixture of mixed-layer ammonium illite-smectite with large expandability and discrete illite. Hydrothermal treatments of the fine fractions of natural kaolinite and illite-smectite produced ammonium illite from kaolinite but the illite-smectite remained unchanged.

Sucha, V.; Elsass, F.; Eberl, D.D.; Kuchta, L'.; Madejova, J.; Gates, W.P.; Komadel, P.

1998-01-01

78

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

79

Bicarbonate produced from carbon capture for algae culture.  

PubMed

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

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

2011-11-01

80

Improving phosphate buffer-free cathode performance of microbial fuel cell based on biological nitrification.  

PubMed

To reduce the amount of phosphate buffer currently used in Microbial Fuel Cell's (MFC's), we investigated the role of biological nitrification at the cathode in the absence of phosphate buffer. The addition of a nitrifying mixed consortia (NMC) to the cathode compartment and increasing ammonium concentration in the catholyte resulted in an increase of cell voltage from 0.3 V to 0.567 V (external resistance of 100 Omega) and a decrease of catholyte pH from 8.8 to 7.05. A large fraction of ammonium was oxidized to nitrite, as indicated by an increase of nitrate-nitrogen (NO(3)(-)-N). An MFC inoculated with an NMC and supplied with 94.2 mgN/l ammonium to the catholyte could generate a maximum power of 2.1+/-0.14 mW (10.94+/-0.73 W/m(3)). This compared favorably to an MFC supplied with either buffered or non-buffered solution. The buffer-free NMC inoculated cathodic chamber showed the smallest polarization resistance, suggesting that nitrification resulted in improved cathode performance. The improved performances of the phosphate buffer-free cathode and cell are positively related to biological nitrification, in which we suggest additional protons produced from ammonium oxidation facilitated electrochemical reduction of oxygen at cathode. PMID:19502045

You, Shi-Jie; Ren, Nan-Qi; Zhao, Qing-Liang; Kiely, Patrick D; Wang, Jing-Yuan; Yang, Feng-Lin; Fu, Lei; Peng, Luo

2009-08-15

81

Effect of sodium bicarbonate and beta-alanine supplementation on maximal sprint swimming  

PubMed Central

Background This study examined the effect of simultaneous supplementation of extracellular buffer sodium bicarbonate (SB) and intracellular buffer beta-alanine (BA) on maximal sprint swimming. Methods Thirteen competitive male swimmers completed 4 different treatments (placebo [PL], SB, BA?+?PL, and BA + SB) in a crossover procedure. PL or SB supplementation (0.3 g/kg body weight) was ingested 60 min before two maximal 100-m freestyle swims that were performed with a passive recovery of 12-min between each swim. Because of the known long washout period for carnosine, four weeks of BA supplementation (4.8 g per day) was started after the first week of PL or SB supplementation and performance testing. Results The first maximal swims were similar, but the increase in time of the second versus the first 100-m swimming time was 1.5 s more (p < 0.05) in PL than in SB. Blood pH values were significantly (p < 0.05) greater in the SB and in the BA + SB groups compared to the PL and BA + PL values. There were no differences in peak blood lactate between the treatments. Conclusion Supplementing with SB prior to performing maximal sprint swimming with repetitions under 60 s improves performance. However, co-supplementation with SB and BA did not confer any added benefit on maximal swim performance. PMID:24215679

2013-01-01

82

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 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...

2012-10-01

83

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

84

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

85

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 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...

2011-10-01

86

REMOTE Shared Memory Buffer #2  

E-print Network

#12;#12;#12;#12;#12;#12;REMOTE Shared Memory Buffer #2 Computer or BackPlane #2 Computer or BackPlane #3 LOCAL Processes Processes #5 NML Server for Buffer #1 NML Server for Buffer #2 ProcessProcessProcess #4 #6 Process Process Process #3#2#1 Computer or BackPlane #1 Shared Memory Buffer #1 #12

87

Bicarbonate kinetics and predicted energy expenditure in critically ill  

Microsoft Academic Search

Background: To determine nutrient requirements by the carbon oxidation techniques, it is necessary to know the fraction of carbon dioxideproducedduringtheoxidativeprocessbutnotexcreted.This fraction has not been described in critically ill children. By measur- ing the dilution of 13C infused by metabolically produced carbon dioxide, the rates of carbon dioxide appearance can be estimated. Energy expenditure can be determined by bicarbonate dilution ki-

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

88

ORIGINAL RESEARCH Systematic family-wide analysis of sodium bicarbonate  

E-print Network

, Atlanta, Georgia, USA 3 Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, Atlanta, Georgia, USA Keywords Bicarbonate transporter, pH, protein interaction, SLC4A7, Xenopus oocyte, Atlanta, GA 30322, USA Tel: 404-712-2092 Fax: 404-727-2648 Email: ichoi@emory.edu Funding Information

Hall, Randy A

89

Buffering limits plasma HCO 3 ? dehydration when red blood cell anion exchange is inhibited  

Microsoft Academic Search

Theory suggests that HCO3? dehydration in the plasma of rainbow trout is limited by both the absence of carbonic anhydrase (CA) activity and the low non-bicarbonate buffer capacity of the plasma (?plasma). The potential for ?plasma to limit plasma HCO3? dehydration was assessed in rainbow trout in which HCO3? dehydration via the red blood cell (RBC) was inhibited using the

K. M. Gilmour; P. R. Desforges; S. F. Perry

2004-01-01

90

76 FR 70366 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...DHS-2008-0076] RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY: National Protection...rulemaking (NPRM), entitled ``Ammonium Nitrate Security Program,'' which was published...62311). Under the proposed Ammonium Nitrate Security Program, the DHS will...

2011-11-14

91

76 FR 47238 - Ammonium Nitrate From Russia  

Federal Register 2010, 2011, 2012, 2013

...731-TA-856; Second Review] Ammonium Nitrate From Russia Determination On the basis...the antidumping duty order on ammonium nitrate from Russia would be likely to lead to...4249 (August 2011), entitled Ammonium Nitrate from Russia: Investigation No....

2011-08-04

92

76 FR 11273 - Ammonium Nitrate From Russia  

Federal Register 2010, 2011, 2012, 2013

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

2011-03-01

93

The effects of acidosis and bicarbonate on action potential repolarization in canine cardiac Purkinje fibers  

PubMed Central

Studies were performed on canine cardiac Purkinje fibers to evaluate the effects of acidosis and bicarbonate (HCO3) on action potential repolarization. Extracellular pH (pHe) was reduced from 7.4 to 6.8 by increasing carbon dioxide (CO2) concentration from 4 to 15% in a HCO3- buffered solution or by NaOH titration in a Hepes-buffered solution. Both types of acidosis produced a slowing of the rate of terminal repolarization (i.e., period of repolarization starting at about -60 mV and ending at the maximum diastolic potential) with an attendant increase in action potential duration of 10--20 ms. This was accompanied by a reduction in the maximum diastolic potential of 2--8 mV. In contrast, if the same pH change was made by keeping CO2 concentration constant and lowering extracellular HCO3 from 23.7 to 6.0 mM, in addition to the slowing of terminal repolarization, the plateau was markedly prolonged resulting in an additional 50- to 80-ms increase in action potential duration. If pHe was held constant at 7.4 and HCO3 reduced from 23.7 mM to 0 (Hepes-buffered solution), the changes in repolarization were nearly identical to those seen in 6.0 mM HCO3 except that terminal repolarization was unchanged. This response was unaltered by doubling the concentration of Hepes. Reducing HCO3 to 12.0 mM produced changes in repolarization of about one-half the magnitude of those in 6.0 mM HCO3. These findings suggest that in Purkinje fibers, HCO3 either acts as a current that slows repolarization or modulates the ionic currents responsible for repolarization. PMID:438770

1979-01-01

94

Hydrothermally grown ZnO buffer layer for the growth of highly (4 wt%) Ga-doped ZnO epitaxial thin films on MgAl 2O 4 (1 1 1) substrates  

Microsoft Academic Search

Gallium (4wt%) doped ZnO (GZO) thin films were deposited on hydrothermally grown ZnO buffered and non-buffered MgAl2O4 (111) substrates by RF magnetron sputtering technique at a growth temperature of 250°C. The epitaxial ZnO buffer layer was deposited on the MgAl2O4 (111) substrate by a hydrothermal technique using aqueous solutions of zinc nitrate hexahydrate, ammonium nitrate and ammonium hydroxide at 90°C.

Seung Wook Shin; Ye Bin Kwon; A. V. Moholkar; Gi-Seok Heo; In Ok Jung; Jong-Ha Moon; Jin Hyeok Kim; Jeong Yong Lee

2011-01-01

95

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

2009-05-01

96

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

97

CCMR: Investigation of Potential Buffer Solutions and Concentrations for an Electrochemical Microfluidic Biosensor  

NSDL National Science Digital Library

Biosensors are analytical devices that are being used to detect a variety of analytes including pathogens via antibody recognition. Liposomes have been used in the Baeumner research group for signal generation and amplification. In one detection strategy, electrochemical signals are being reported by entrapping a redox couple in the inner cavity of the liposomes and releasing them upon detection of the pathogen. The main task of this research was the optimization of a buffer system that can be used for the entrapment of the redox couple and does not inhibit the oxidation and reduction reactions on a gold electrode. Potassium ferrihexacyanide and potassium ferrohexacyanide (ferri/ferrohexacyanide) were used as redox couple and dissolved in 0.01M bicarbonate buffer, pH 7.0; 0.01M and 0.1M sodium borate buffers, pH 7.0; and 0.01M and 0.1M phosphate buffers, pH 7.0. The current produced by flowing each of these solutions through a 500μm long by 50μm deep channel in polydimethylsiloxane (PDMS) over the interdigitated ultramicroelectrode array (IDUA) was measured using amperometry. The resulting signal peaks created by the redox cycling of ferri/ferrohexacyanide on the electrode were compared. A 10μM solution of ferri/ferrohexacyanide gave signals of 0.44nA in 0.01M phosphate buffer, 0.41nA in sodium borate, 0.37nA in sodium borate diluted in phosphate buffer, and 0.04nA in 0.01M bicarbonate. Since the phosphate buffer cannot be used for liposome synthesis, it was determined that the sodium borate buffer might be the best alternative.

Wiles, Laura K.

2009-08-15

98

Riparian Forest Buffer Restoration TRiparian Forest Buffer Restoration TRiparian Forest Buffer Restoration TRiparian Forest Buffer Restoration TRiparian Forest Buffer Restoration Targetingargetingargetingargetingargeting for the Yfor the Yfor the Yfor the  

E-print Network

1 Riparian Forest Buffer Restoration TRiparian Forest Buffer Restoration TRiparian Forest Buffer Restoration TRiparian Forest Buffer Restoration TRiparian Forest Buffer Restoration resource that protects water quality" (Riparian Forest Buffers, 1996). In addition to protecting water

99

Transplastomic integration of a cyanobacterial bicarbonate transporter into tobacco chloroplasts.  

PubMed

Improving global yields of agricultural crops is a complex challenge with evidence indicating benefits in productivity are achieved by enhancing photosynthetic carbon assimilation. Towards improving rates of CO2 capture within leaf chloroplasts, this study shows the versatility of plastome transformation for expressing the Synechococcus PCC7002 BicA bicarbonate transporter within tobacco plastids. Fractionation of chloroplast membranes from transplastomic tob(BicA) lines showed that ~75% of the BicA localized to the thylakoid membranes and ~25% to the chloroplast envelope. BicA levels were highest in young emerging tob(BicA) leaves (0.12 ?mol m(-2), ?7mg m(-2)) accounting for ~0.1% (w/w) of the leaf protein. In these leaves, the molar amount of BicA was 16-fold lower than the abundant thylakoid photosystem II D1 protein (~1.9 ?mol m(-2)) which was comparable to the 9:1 molar ratio of D1:BicA measured in air-grown Synechococcus PCC7002 cells. The BicA produced had no discernible effect on chloroplast ultrastructure, photosynthetic CO2-assimilation rates, carbon isotope discrimination, or growth of the tob(BicA) plants, implying that the bicarbonate transporter had little or no activity. These findings demonstrate the utility of plastome transformation for targeting bicarbonate transporter proteins into the chloroplast membranes without impeding growth or plastid ultrastructure. This study establishes the span of experimental measurements required to verify heterologous bicarbonate transporter function and location in chloroplasts and underscores the need for more detailed understanding of BicA structure and function to identify solutions for enabling its activation and operation in leaf chloroplasts. PMID:24965541

Pengelly, J J L; Förster, B; von Caemmerer, S; Badger, M R; Price, G D; Whitney, S M

2014-07-01

100

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

101

Influence of Carbohydrate Source and Buffer on Rumen Fermentation Characteristics, Milk Yield, and Milk Composition in Early-Lactation Holstein Cows  

Microsoft Academic Search

The effects of concentrate to forage ratio and sodium bicarbonate (buffer) supplementation on intake, rumi- nal fermentation characteristics, digestibility coeffi- cients, milk yield, and milk composition were examined in 4 cannulated Holstein cows (100 ± 20 d in milk). A 4 × 4 Latin square design with 2 × 2 factorial arrange- ment of treatments was implemented for 3-wk experi-

J. J. Kennelly; B. Robinson; G. R. Khorasani

1999-01-01

102

Deliquescence, Efflorescence, and Water Activity in Ammonium Nitrate and Mixed Ammonium Nitrate/Succinic Acid Microparticles  

E-print Network

Deliquescence, Efflorescence, and Water Activity in Ammonium Nitrate and Mixed Ammonium Nitrate of ammonium nitrate/water and mixed ammonium nitrate/succinic acid/water microparticles. The water activity of ammonium nitrate microparticles is determined as a function of composition down to 12% relative humidity

103

Segmental analysis of the renal tubule in buffer production and net acid formation.  

PubMed

Papillary and surface micropuncture in Munich-Wistar rats was used to assess the role of proximal segments of superficial and juxtamedullary (JM) nephrons, the distal tubule of superficial nephrons, and the terminal collecting duct in acid excretion. The relative role of these segments in ammonium production, bicarbonate reclamation, and net acid formation was assessed under hydropenic conditions and after a chronic acid load. In these two settings the proximal segment of both kinds of nephrons is the major site of ammonium production and bicarbonate reclamation. However, this segment's contribution to net acid formation was only significant during acidosis. On the other hand, segments beyond the distal tubule appear to be the major site of acid formation. In situ pH measurements were lower in these nephron segments and fell even more after the induction of an acidosis. Ammonia appears to enter fluid between the end of the distal tubule and the base of the collecting duct. In vivo pH measurements made near the bend of Henle's loop of JM nephrons were more alkaline than near the end of the proximal tubule of superficial nephrons. It is postulated that this difference in pH allows ammonium to dissociate, permitting the movement of ammonia out of the tubule lumen and into collecting duct fluid where it is protonated and, therefore, reentrapped. This process is enhanced by the ingestion of a chronic acid load. PMID:6837741

Buerkert, J; Martin, D; Trigg, D

1983-04-01

104

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

105

Grocery Store Baking SodaA Source of Sodium Bicarbonate in the Management of Chronic Metabolic Acidosis  

Microsoft Academic Search

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

Beverley E. Booth; Jay Gates; R. Curtis Morris

1984-01-01

106

Evaluation of flow fields on bubble removal and system performance in an ammonium bicarbonate reverse electrodialysis stack  

E-print Network

, stacks of alternating ion selective membranes are used to separate the high concentration solution increases which drives electrochemical redox reactions at electrodes and ultimately electricity generation

107

Using ammonium bicarbonate as pore former in activated carbon catalyst layer to enhance performance of air cathode microbial fuel cell  

NASA Astrophysics Data System (ADS)

The rolling catalyst layers in air cathode microbial fuel cells (MFCs) are prepared by introducing NH4HCO3 as pore former (PF) with four PF/activated carbon mass ratios of 0.1, 0.2, 0.3 and 1.0. The maximum power density of 892 ± 8 mW m-2 is obtained by cathodes with the mass ratio of 0.2, which is 33% higher than that of the control reactor (without PF, 671 ± 22 mW m-2). Pore analysis indicates the porosity increases by 38% and the major pore range concentrates between 0.5 ?m-0.8 ?m which likely facilitates to enrich the active reaction sites compared to 0.8 ?m-3.0 ?m in the control and other PF-cathodes. In addition, pore structure endows the cathode improved exchange current density by 2.4 times and decreased charge transfer resistance by 44%, which are the essential reasons to enhance the oxygen reduction. These results show that addition of NH4HCO3 proves an effective way to change the porosity and pore distribution of catalyst layers and then enhance the MFC performance.

Li, Da; Qu, Youpeng; Liu, Jia; He, Weihua; Wang, Haiman; Feng, Yujie

2014-12-01

108

Mail-System insert.remove.BUFFER  

E-print Network

Beispiel: Mail-System MS := (FILE j BUFFER[f FM ] j BUFFER[f MF ] j MAIL j DELIVER j BUFFER[f CM : insert 7! xy insert remove 7! xy remove empty 7! xy empty #12; BUFFER := insert.remove.BUFFER + empty.BUFFER.DELIVER) COLLECT := letter posted .cm insert.COLLECT #12; Beispiel: Mail-System FILE BUFFER[f MF ] BUFFER[f FM

Popeea, Corneliu - Chair for Foundations of Software Reliability and Theoretical Computer Science

109

Buffer capacity of the coelomic fluid in echinoderms.  

PubMed

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

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

2013-09-01

110

Regulation and roles of bicarbonate transporters in cancer  

PubMed Central

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

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

2014-01-01

111

Physiological carbon dioxide, bicarbonate, and pH sensing  

PubMed Central

In biological systems, carbon dioxide exists in equilibrium with bicarbonate and protons. The individual components of this equilibrium (i.e., CO2, HCO3?, and H+), which must be sensed to be able to maintain cellular and organismal pH, also function as signals to modulate multiple physiological functions. Yet, the molecular sensors for CO2/HCO3?/pH remained unknown until recently. Here, we review recent progress in delineating molecular and cellular mechanisms for sensing CO2, HCO3?, and pH. PMID:20683624

Tresguerres, Martin; Buck, Jochen

2010-01-01

112

Effects of Oral Sodium Bicarbonate in Patients with CKD  

PubMed Central

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

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

2013-01-01

113

Effect of ammonium and nitrate on net photosynthesis, flower formation, growth and yield of eggplants ( Solanum melongena L.)  

Microsoft Academic Search

Eggplants (Solanum melongena L. cv. Bonica) were grown in a glasshouse during summer under natural light with one unbranched shoot or one shoot with 3\\u000a to 4 branches and with or without fruit in quartz sand buffered and not buffered with 0.5% CaCO3 (w : v), respectively. Nutrient solutions supplied contained nitrate or ammonium as the sole nitrogen source.\\u000a \\u000a Compared

W. Claussen; F. Lenz

1995-01-01

114

Cyclo-hexyl-ammonium nitrate  

PubMed Central

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

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

2014-01-01

115

Virtual Frame Buffer Interface Program  

NASA Technical Reports Server (NTRS)

Virtual Frame Buffer Interface program makes all frame buffers appear as generic frame buffer with specified set of characteristics, allowing programmers to write codes that run unmodified on all supported hardware. Converts generic commands to actual device commands. Consists of definition of capabilities and FORTRAN subroutines called by application programs. Developed in FORTRAN 77 for DEC VAX 11/780 or DEC VAX 11/750 computer under VMS 4.X.

Wolfe, Thomas L.

1990-01-01

116

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

117

In vitro penetration of pig oocytes in a modified Tris-buffered medium: effect of BSA, caffeine and calcium  

Microsoft Academic Search

The effect of BSA, caffeine and calcium was studied on the penetration of pig oocytes by frozen-thawed spermatozoa in a modified Tris-buffered medium (mTBM) without added bicarbonate. Pig cumulus-oocyte complexes (COC) were cultured in BSA-free NCSU 23 medium containing porcine follicular fluid (10%), cysteine (0.1 mg\\/ml) and hormonal supplements (eCG and hCG: 10 IU\\/ml each) for 22 h. The COC

L. R. Abeydeera; B. N. Day

1997-01-01

118

Blood-brain barrier impairment by low pH buffer perfusion via the internal carotid artery in rat  

Microsoft Academic Search

Krebs-Ringer bicarbonate buffer (KRB) adjusted by lactic acid to low pH levels (6.6, 6.2, 6.0, 5.8, 5.5) was perfused via the internal carotid artery as a bolus into rat brain hemispheres. In one group of animals, the fluid phase tracer horseradish peroxidase (HRP) was perfused immediately following the low pH treatment. In the other group of animals, the brain hemispheres

Z. Nagy; M. Szabó; I. Hüttner

1985-01-01

119

21 CFR 184.1138 - Ammonium chloride.  

...sodium chloride and an ammonium salt in solution. The less soluble sodium salt...Ammonium chloride is crystallized from the solution. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed. (1981),...

2014-04-01

120

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

121

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2010 CFR

...Affirmed as GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4 )2 CO3 , CAS Reg. No. 8000-73-5...sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard,...

2010-04-01

122

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2013 CFR

...Affirmed as GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4 )2 CO3 , CAS Reg. No. 8000-73-5...sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard,...

2013-04-01

123

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2011 CFR

...Affirmed as GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4 )2 CO3 , CAS Reg. No. 8000-73-5...sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard,...

2011-04-01

124

21 CFR 184.1137 - Ammonium carbonate.  

Code of Federal Regulations, 2012 CFR

...Affirmed as GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4 )2 CO3 , CAS Reg. No. 8000-73-5...sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard,...

2012-04-01

125

21 CFR 184.1137 - Ammonium carbonate.  

...Affirmed as GRAS § 184.1137 Ammonium carbonate. (a) Ammonium carbonate ((NH4 )2 CO3 , CAS Reg. No. 8000-73-5...sublimation of a mixture of ammonium sulfate and calcium carbonate and occurs as a white powder or a hard,...

2014-04-01

126

Extraction of urea and ammonium ion  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

127

Ammonium content and buoyancy in midwater cephalopods  

E-print Network

Ammonium content and buoyancy in midwater cephalopods Brad A. Seibela,*, Shana K. Goffredib , Erik for neutral buoyancy. However, previous methods for measuring ammonium did not distinguish between NH4 Elsevier B.V. All rights reserved. Keywords: Buoyancy; Ammonium; Cephalopoda; Locomotion; Deep-sea; Pelagic

Thuesen, Erik V.

128

76 FR 62311 - Ammonium Nitrate Security Program  

Federal Register 2010, 2011, 2012, 2013

...DHS-2008-0076] RIN 1601-AA52 Ammonium Nitrate Security Program AGENCY: National Protection...rulemaking (NPRM), entitled ``Ammonium Nitrate Security Program,'' which was published...regulate the sale and transfer of ammonium nitrate pursuant to section 563 of the...

2011-10-07

129

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

130

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

131

Ring Buffered Network Bus  

NASA Technical Reports Server (NTRS)

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

1997-01-01

132

Association of Dialysate Bicarbonate Concentration With Mortality in the Dialysis Outcomes and Practice Patterns Study (DOPPS)  

PubMed Central

Background Most hemodialysis patients worldwide are treated with bicarbonate dialysis using sodium bicarbonate as the base. Few studies have assessed outcomes of patients treated with different dialysate bicarbonate levels, and the optimal concentration remains uncertain. Study Design The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective cohort study. Setting & Participants This study included 17,031 patients receiving thrice-weekly in-center hemodialysis from 11 DOPPS countries (2002–2011). Predictor Dialysate bicarbonate. Outcomes All-cause and cause-specific mortality and first hospitalization, using Cox regression to estimate the effects of dialysate bicarbonate concentration, adjusting for potential confounders. Measurements Demographics, comorbid conditions, laboratory values, and prescriptions were abstracted from medical records. Results Mean dialysate bicarbonate was 35.5 ± 2.7 (SD) mEq/L, ranging from 32.2 ± 2.3 mEq/L in Germany to 37.0 ± 2.6 mEq/L in the US. Prescription of high dialysate bicarbonate (?38 mEq/L) was most common in the US (45% of patients). Approximately 50% of DOPPS facilities used a single dialysate bicarbonate concentration. 3,913 patients (23%) died during follow-up. Dialysate bicarbonate concentration was positively associated with mortality (adjusted HR, 1.08 per 4 mEq/L higher [95% CI, 1.01–1.15]; HR for dialysate bicarbonate ?38 vs. 33–37 mEq/L, 1.07 [95% CI, 0.97–1.19]). Results were consistent across levels of pre-dialysis session serum bicarbonate and between facilities that used a single dialysate bicarbonate concentration and those that prescribed different concentrations to individual patients. The association of dialysis bicarbonate with mortality was stronger in patients with longer dialysis vintage. Limitations Due to the observational nature of the current study, we cannot rule out that the reported associations may be biased by unmeasured confounders. Conclusions High dialysate bicarbonate, especially prolonged exposure, may contribute to adverse outcomes, likely through development of post-dialysis metabolic alkalosis. Additional studies are warranted to identify the optimal dialysate bicarbonate concentration. PMID:23707043

Tentori, Francesca; Karaboyas, Angelo; Robinson, Bruce M.; Morgenstern, Hal; Zhang, Jinyao; Sen, Ananda; Ikizler, T. Alp; Rayner, Hugh; Fissell, Rachel B.; Vanholder, Raymond; Tomo, Tadashi; Port, Friedrich K.

2013-01-01

133

Phase diagram of ammonium nitrate  

NASA Astrophysics Data System (ADS)

Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

Dunuwille, M.; Yoo, C. S.

2014-05-01

134

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

Code of Federal Regulations, 2013 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2013-10-01

135

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

Code of Federal Regulations, 2012 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2012-10-01

136

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

Code of Federal Regulations, 2011 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2011-10-01

137

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

Code of Federal Regulations, 2010 CFR

...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415...Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate...

2010-10-01

138

Bicarbonate transport along the loop of Henle. I. Microperfusion studies of load and inhibitor sensitivity.  

PubMed Central

We microperfused the loop of Henle (LOH) to assess its contribution to urine acidification in vivo. Under control conditions (Na HCO3- = 13 mM, perfusion rate approximately 17 nl/min-1) net bicarbonate transport (JHCO3-) was unsaturated, flow- and concentration-dependent, and increased linearly until a bicarbonate load of 1,400 pmol.min-1 was reached. Methazolamide (2 x 10(-4) M) reduced JHCO3 by 70%; the amiloride analogue ethylisopropylamiloride (EIPA) (2 x 10(-4) M) reduced JHCO3 by 40%; neither methazolamide nor EIPA affected net water flux (Jv). The H(+)-ATPase inhibitor bafilomycin A1 (10(-5) M) reduced JHCO3 by 20%; the Cl- channel inhibitor 5-nitro-2'-(3-phenylpropylamino)-benzoate (2 x 10(-4) M) and the Cl(-)-base exchange inhibitor diisothiocyanato-2,2'-stilbenedisulfonate (5 x 10(-5) M), had no effect on fractional bicarbonate reabsorption. Bumetanide (10(-6) M) stimulated bicarbonate transport (net and fractional JHCO3-) by 20%, whereas furosemide (10(-4) M) had no effect on bicarbonate reabsorption; both diuretics reduced Jv. In summary: (a) the LOH contributes significantly to urine acidification. It normally reabsorbs an amount equivalent to 15% of filtered bicarbonate; (b) bicarbonate reabsorption is not saturated; (c) Na(+)-H+ exchange and an ATP-dependent proton pump are largely responsible for the bulk of LOH bicarbonate transport. PMID:1830889

Capasso, G; Unwin, R; Agulian, S; Giebisch, G

1991-01-01

139

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

E-print Network

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

Machen, Terry E.

140

The Effect of Bicarbonate on Photosynthetic Oxygen Evolution in Flashing Light in Chloroplast Fragments  

E-print Network

Fragments (photosynthesis/Hill reaction/photochemical reactions of system II) ALAN STEMLER, GERALD TThe Effect of Bicarbonate on Photosynthetic Oxygen Evolution in Flashing Light in Chloroplast-4683, December 1974 The Effect of Bicarbonate on Photosynthetic Oxygen Evolution in Flashing Light in Chloroplast

Govindjee

141

Bactericidal action of bicarbonate ion on selected periodontal pathogenic microorganisms.  

PubMed

Organisms representative of soil, skin and fecal flora and of supragingival and subgingival flora were tested for inhibition of growth and killing by various salts (NaHCO3, NaCl, MgSO4). The antimicrobial activities of KHCO3, NaF, sodium lauryl sulfate (SLS) and chloramine T were also compared with that of NaHCO3, and the rate at which NaHCO3 exerts its bactericidal effect was studied. Suspected periodontal pathogens were more susceptible to salts than were control non-oral bacteria. Supragingival plaque organisms showed intermediate susceptibility. Periodontal pathogens were more susceptible to NaHCO3 than to NaCl; NaHCO3 and KHCO3 showed similar activity against all strains tested. Accordingly, the antibacterial activity of NaHCO3 is not simply an osmotic effect and is due to the bicarbonate ion. NaF, SLS and chloramine T had greater antimicrobial activity than NaHCO3. Supragingival bacteria required at least 6-hour exposure to 1.0 M NaHCO3 to produce 99% lethality (decrease colony-forming units by 2 log10), whereas selected periodontal pathogens were killed more rapidly (30-120 minutes). The higher the concentration of bicarbonate, the faster the lethality. Morphologic examination by transmission electron microscopy of organisms exposed to bactericidal salt concentrations revealed marked fibrillar condensations within the cytoplasm and shrinkage of the cytoplasm from the outer membrane. For NaHCO3 to be clinically effective, a high concentration must be introduced into the periodontal pocket and maintained there long enough to kill periodontal pathogens. Furthermore, NaHCO3 must be reapplied often enough to prevent recolonization by these pathogens. An advantage of NaHCO3 over NaF, SLS and other antimicrobial agents is its safety, availability and low cost. PMID:6094783

Newbrun, E; Hoover, C I; Ryder, M I

1984-11-01

142

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

143

Message Buffering in Epidemic Data Dissemination  

E-print Network

Message Buffering in Epidemic Data Dissemination I. This work is supported in part by TUBITAK (The is the buffer space used by individual peers of the group. Our aim is to optimize the buffer space while and compare it with a hash- based approach for buffer management. The effect of short and long term buffering

Caglar, Mine

144

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

PubMed

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

Lisawat, Panupong; Gennari, F John

2014-07-01

145

Effects of sodium bicarbonate on butyric acid-induced epithelial cell damage in vitro.  

PubMed

Butyric acid is detected in periodontal pockets and is thought to be involved in the initiation and progression of periodontal disease. We examined the effects of sodium bicarbonate on the butyric acid-induced epithelial cell damage. The human gingival carcinoma cell line Ca9-22 was cultured in medium that contained butyric acid with or without sodium bicarbonate. The viability of cells treated with sodium bicarbonate was significantly higher than that of cells treated with butyric acid alone. The effects of butyric acid on ICAM-1 expression were significantly improved by sodium bicarbonate. Within the limitations of this in vitro study, sodium bicarbonate was indicated to be a useful therapeutic agent to reduce the butyric acid-induced periodontal tissue damage. PMID:19106468

Takigawa, Satoko; Sugano, Naoyuki; Ochiai, Kuniyasu; Arai, Noriyuki; Ota, Noriko; Ito, Koichi

2008-12-01

146

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 among athletes and is an expanding market in terms of product choice and availability. The purpose of this study was to examine the effects of 2 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 men (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-controlled design. Subjects ingested (a) 300 mg·kg-1 body mass NaHCO3 (BICARB), (b) 45 mg·kg-1 body mass sodium chloride (PL-BICARB) as the placebo for the NaHCO3 trial, (c) 1115 mg lactate (LACTATE), or (d) plain flour as the placebo for the lactate trial (PL-LACTATE) 60 minutes before exercise. There was no significant difference in performance between the 4 conditions (p > 0.05). Although 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 3 conditions. Neither NaHCO3 nor lactate supplementation seem 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 A; Vince, Rebecca V

2014-01-01

147

Effect of carbonic anhydrase inhibition on superficial and deep nephron bicarbonate reabsorption in the rat.  

PubMed Central

The nephron segment responsible for the acetazolamide-insensitive fraction of renal bicarbonate reabsorption has not been clearly delineated. This study compares superficial and deep nephron bicarbonate reabsorption before and after acetazolamide at two dose levels (20 and 50 mg/kg per h) in mutant Munich-Wistar rats employing both cortical and papillary micropuncture and microcalorimetry. Systemic acid-base balance and right whole kidney glomerular filtration rate were similar in all groups examined. The effects of the two doses of acetazolamide were indistinguishable and resulted in a significant increase in whole kidney bicarbonate excretion that compared favorably with the fraction delivered out of the left papillary tip. Acetazolamide inhibited superficial proximal bicarbonate reabsorption by 80.0%, whereas reabsorption up to the deep loop of Henle was decreased by only 52% (P less than 0.001). Bicarbonate reabsorption that was insensitive to acetazolamide occurred in the superficial and deep loop of Henle and between the distal tubule and base collecting duct. Because water reabsorption in these segments could serve to generate transepithelial bicarbonate concentration gradients favorable for reabsorption, we attempted to minimize water abstraction by combined administration of mannitol and acetazolamide. During this condition a significant increase in bicarbonate delivery up to the deep loop of Henle was noted (52 vs. 65%), whereas superficial nephron reabsorption was not altered. Furthermore, an outwardly directed bicarbonate concentration gradient from the deep loop of Henle to vasa recta was demonstrated during acetazolamide (delta tCO2 = 20.9 +/- 3.3 mM), but was abolished during combined mannitol and acetazolamide administration (delta tCO2 = 3.5 +/- 0.9 mM). It is concluded that carbonic anhydrase inhibition results in a disparate effect on nephron bicarbonate reabsorption when juxtamedullary and superficial nephron segments are compared. Our findings suggest that a mechanism for residual bicarbonate reabsorption during acetazolamide administration may be passive reabsorption driven by favorable transepithelial concentration gradients. Images PMID:6848559

DuBose, T D; Lucci, M S

1983-01-01

148

Understanding the Science Behind Riparian Forest Buffers  

E-print Network

Understanding the Science Behind Riparian Forest Buffers: Resources for Virginia Landowners #12 Forest Buffers: Resources for Virginia Landowners by Julia C. Klapproth and James E. Johnson forest buffers can provide many benefits to society through improved water quality, reduced flooding

Liskiewicz, Maciej

149

Ammonium Metabolism in the Green Hydra Symbiosis  

Microsoft Academic Search

Abstract. Inhibitors of enzymes,of ammonium,assimi- lation were used to test if assimilation of ammonium,in the green,hydra-Chlorella symbiosis,was,due,to host or symbionts. Both methionine sulphoximine (MSX, an in- hibitor of glutamine synthetase, found in both host and symbionts) and azaserine (AZS, an inhibitor of 2-oxoglu- tarate amido transferase, not found in the host) inhibited ammonium,uptake by the intact symbiosis. MSX was taken

P. J. Mcauley

1995-01-01

150

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

151

Quantitative assessment of intrinsic carbonic anhydrase activity and the capacity for bicarbonate oxidation in photosystem II.  

PubMed

On the basis of equilibrium isotopic distribution experiments using (18)O-labeled water, it is generally accepted that water is the sole substrate for O(2) production by photosystem II (PSII). Nevertheless, recent studies indicating a direct interaction between bicarbonate and the donor side of PSII have been used to hypothesize that bicarbonate may have been a physiologically important substrate for O(2) production during the evolution of PSII [Dismukes, G. C., Klimov, V. V., Baranov, S. V., Kozlov, Y. N., DasGupta, J., and Tyryshikin, A. (2001) Proc. Natl. Acad. Sci. U.S.A. 98, 2170-2175]. To test out this hypothesis and to determine whether contemporary oxygenic organisms have the capacity to oxidize bicarbonate, we employed special rapid-mixing isotopic experiments using (18)O/(13)C-labeled bicarbonate to quantify the inherent carbonic anhydrase activity in PSII samples and the potential flux of oxygen from bicarbonate into the photosynthetically produced O(2). The measurements were made on PSII samples prepared from spinach, Thermosynechococcus elongatus, and Arthrospira maxima. For the latter organism, a strain was used that grows naturally in an alkaline, high (bi)carbonate soda lake in Africa. The results reveal that bicarbonate is not the substrate for O(2) production in these contemporary oxygenic photoautotrophs when assayed under single turnover conditions. PMID:16475798

Hillier, Warwick; McConnell, Iain; Badger, Murray R; Boussac, Alain; Klimov, Vyacheslav V; Dismukes, G Charles; Wydrzynski, Tom

2006-02-21

152

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

...Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2014-07-01

153

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

Code of Federal Regulations, 2013 CFR

...Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2013-07-01

154

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

Code of Federal Regulations, 2011 CFR

...Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2011-07-01

155

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

Code of Federal Regulations, 2012 CFR

...Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2012-07-01

156

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

Code of Federal Regulations, 2010 CFR

...Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Ammonium nitrate, ammonium nitrate fertilizers, fertilizer mixtures, or nitro carbo nitrate; general provisions. 126.28 Section 126.28 Navigation and...

2010-07-01

157

Buffer Gas Acquisition and Storage  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

158

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

PubMed Central

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

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

2013-01-01

159

Bicarbonate of soda paint stripping process validation and material characterization  

NASA Technical Reports Server (NTRS)

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

Haas, Michael N.

1995-01-01

160

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2012 CFR

...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

161

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2013 CFR

...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...

2013-10-01

162

46 CFR 148.205 - Ammonium nitrate and ammonium nitrate fertilizers.  

Code of Federal Regulations, 2011 CFR

...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

163

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

DOEpatents

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

Bhattacharya, Raghu N. (Littleton, CO)

2009-11-03

164

Tri-benzyl-ammonium chloride.  

PubMed

Single crystals of the title salt, C21H21NH(+)·Cl(-), were isolated as a side product from the reaction involving [(C6H5CH2)3NH]2[HPO4] and Sn(CH3)3Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetra-hedral environment, with angles ranging from 107.7 to 111.16?(10)°. In the crystal, the tri-benzyl-ammonium cations and chloride anions are linked through N-H?Cl and C-H?Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin. PMID:24860409

Diallo, Waly; Diop, Libasse; Plasseraud, Laurent; Cattey, Hélène

2014-05-01

165

Tri-benzyl-ammonium chloride  

PubMed Central

Single crystals of the title salt, C21H21NH+·Cl?, were isolated as a side product from the reaction involving [(C6H5CH2)3NH]2[HPO4] and Sn(CH3)3Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetra­hedral environment, with angles ranging from 107.7 to 111.16?(10)°. In the crystal, the tri­benzyl­ammonium cations and chloride anions are linked through N—H?Cl and C—H?Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin. PMID:24860409

Diallo, Waly; Diop, Libasse; Plasseraud, Laurent; Cattey, Helene

2014-01-01

166

Buffer Tank Design for Acceptable Control Performance  

E-print Network

Buffer Tank Design for Acceptable Control Performance Audun Faanes and Sigurd Skogestad for the design of buffer tanks. We consider mainly the case where the objective of the buffer tank is to dampen-mail: skoge@chemeng.ntnu.no, Tel.: +47 73 59 41 54, Fax.: +47 73 59 40 80 1 #12;1 Introduction Buffer tanks

Skogestad, Sigurd

167

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

168

Ammonium repression of nitrate reductase formation in Lemna minor L  

Microsoft Academic Search

The presence of ammonium is shown to inhibit the nitrate-promoted formation of nitrate reductase in Lemna minor L. The ammonium inhibition does not result from an inhibition of nitrate accumulation. The kinetics of the ammonium inhibition suggest it is not a direct effect of ammonium. The inhibition could result from the build up of a product of ammonium assimilation or

T. O. Orebamjo; G. R. Stewart

1975-01-01

169

Biodegradation of rocket propellant waste, ammonium perchlorate  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

170

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

PubMed Central

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

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

2007-01-01

171

Redox interaction of Mn-bicarbonate complexes with reaction centres of purple bacteria.  

PubMed

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

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

2008-03-27

172

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

...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)...

2014-04-01

173

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

174

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2011 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)...

2011-04-01

175

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2012 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)...

2012-04-01

176

21 CFR 862.1160 - Bicarbonate/carbon dioxide test system.  

Code of Federal Regulations, 2010 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)...

2010-04-01

177

In Vitro EGF Receptor Autophosphorylation Buffers Needed  

E-print Network

1 In Vitro EGF Receptor Autophosphorylation Buffers Needed: Lysis Buffer: 25 mM HEPES, pH 7.2, 1 mM PMSF, 1 mM EDTA, 2 µg/ml leupeptin, 1 µg/ml pepstatin and 1 µg/ml 2-macroglobulin. Assay Buffer: 70 m buffered saline to remove serum proteins. 2. Approximately 3 to 5 ml lysis buffer is added to the plate

Pike, Linda J.

178

Haemodynamic consequences of changing bicarbonate and calcium concentrations in haemodialysis fluids  

PubMed Central

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

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

2009-01-01

179

Plasma secretin and pancreatic bicarbonate response to exogenous secretin in man  

Microsoft Academic Search

The dose response of duodenal bicarbonate production during synthetic porcine secretin infusions was studied in six healthy volunteers and related to plasma secretin immunoreactivity. Secretin was infused in each individual at four different doses from 0-1 to 2-7 CU\\/kg\\/h, each infusion lasting for 60 minutes. Mean maximal bicarbonate secretion was 33 +\\/- 4 mEq\\/h. The secretin plasma level for half

W H HACKI; S R Bloom; P Mitznegg; W Domschke; S Domschke; D Belohlavek; L Demling; E Wünsch

1977-01-01

180

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

181

Clinical experience with two physiologic bicarbonate\\/lactate peritoneal dialysis solutions in automated peritoneal dialysis  

Microsoft Academic Search

Clinical experience with two physiologic bicarbonate\\/lactate peritoneal dialysis solutions in automated peritoneal dialysis.Background. Patients on automated peritoneal dialysis (APD) usually receive larger volumes of dialysis solution and more frequent, shorter exchanges than patients on continuous ambulatory peritoneal dialysis (CAPD), and therefore are likely to derive greater benefit from more physiologic solutions.MethodsPeritoneal dialysis solutions containing 25 mmol\\/L bicarbonate and either 10

MAX DRATWA; MARTIN WILKIE; JEAN-PHILIPPE RYCKELYNCK; PM TER WEE; PETER RUTHERFORD; CATHERINE MICHEL; ALEXANDRA HOPWOOD; LYNNE CURTIS; NICOLAS DENYS; Jose C. Divino Filho; DIRK FAICT

2003-01-01

182

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. PMID:11748264

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

183

Buffered Routing Tree Construction Under Buffer Placement Interconnect delay has become a critical factor in  

E-print Network

1 Buffered Routing Tree Construction Under Buffer Placement Blockages Abstract Interconnect delay and buffering are powerful means of improving the circuit speed and correcting the timing violations after net topology construction and buffer insertion and sizing simultaneously under the given buffer

Pedram, Massoud

184

Frog striated muscle is permeable to hydroxide and buffer anions.  

PubMed

Hydroxide, bicarbonate and buffer anion permeabilities in semitendinosus muscle fibers of Rana pipiens were measured. In all experiments, the fibers were initially equilibrated in isotonic, high K2SO4 solutions at pHo = 7.2 buffered with phosphate. Two different methods were used to estimate permeabilities: (i) membrane potential changes were recorded in response to changes in external ion concentrations, and (ii) intracellular pH changes were recorded in response to changes in external concentrations of ions that alter intracellular pH. Constant field equations were used to calculate relative or absolute permeabilities. In the first method, to increase the size of the membrane potential change produced by a sudden change in anion entry, external K+ was replaced by Cs+ prior to changes of the anion under study. At constant external Cs+ activity, a hyperpolarization results from increasing external pH from 7.2 to 10.0 or higher, using either CAPS (3-[cyclohexylamino]-1-propanesulfonic acid) or CHES (2-[N-cyclohexylamino]-ethanesulfonic acid) as buffer. For each buffer, the protonated form is a zwitterion of zero net charge and the nonprotonated form is an anion. Using reported values of H+ permeability, calculations show that the reduction in [H+]o cannot account for the hyperpolarizations produced by alkaline solutions. Membrane hyperpolarization increases with increasing total external buffer concentration at constant external pH, and with increasing external pH at constant external buffer anion concentration. Taken together, these observations indicate that both OH- and buffer anions permeate the surface membrane. The following relative permeabilities were obtained at pHo = 10.0 +/- 0.3: (POH/PK) = 890 +/- 150, (PCAPS/PK) = 12 +/- 2, (PCHES/PK) = 5.3 +/- 0.9, and (PNO3/PK) = 4.7 +/- 0.5. PNO3/PK was independent of pHo up to 10.75. At pHo = 9.6, (PHCO3/PK) = 0.49 +/- 0.03; at pHo = 8.9, (PCl/PK) = 18 +/- 2 and at pHo = 7.1, (PHEPES/PK) = 20 +/- 2. In the second method, on increasing external pH from 7.2 to 10.0, using 2.5 mM CAPS (total buffer concentration), the internal pH increases linearly with time over the next 10 min. This alkalinization is due to the entry of OH- and the absorption of internal H+ by entering CAPS- anion. The rate of CAPS- entry was determined in experiments in which the external CAPS concentration was increased at constant external pH. Such increases invariably produced an increase in the rate of internal alkalinization, which was reversed when the CAPS concentration was reduced to its initial value.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8071988

Venosa, R A; Kotsias, B A; Horowicz, P

1994-04-01

185

40 CFR 721.6070 - Alkyl phosphonate ammonium salts.  

Code of Federal Regulations, 2011 CFR

... Alkyl phosphonate ammonium salts. 721.6070 Section 721... Alkyl phosphonate ammonium salts. (a) Chemical substances...as alkyl phosphonate ammonium salts (PMNs P-93-725 and P-93-726...uses are: (i) Release to water. Requirements as...

2011-07-01

186

40 CFR 721.6070 - Alkyl phosphonate ammonium salts.  

Code of Federal Regulations, 2013 CFR

... Alkyl phosphonate ammonium salts. 721.6070 Section 721... Alkyl phosphonate ammonium salts. (a) Chemical substances...as alkyl phosphonate ammonium salts (PMNs P-93-725 and P-93-726...uses are: (i) Release to water. Requirements as...

2013-07-01

187

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

188

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

189

78 FR 32690 - Certain Ammonium Nitrate From Ukraine  

Federal Register 2010, 2011, 2012, 2013

...731-TA-894 (Review)] Certain Ammonium Nitrate From Ukraine Determination On the basis...antidumping duty order on certain ammonium nitrate from Ukraine would be likely to lead to...May 2013), entitled Certain Ammonium Nitrate from Ukraine: Investigation No....

2013-05-31

190

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

191

Ammonium handling by superficial and juxtamedullary nephrons in the rat. Evidence for an ammonia shunt between the loop of Henle and the collecting duct.  

PubMed

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. PMID:7085880

Buerkert, J; Martin, D; Trigg, D

1982-07-01

192

Photosynthetic Utilization of Bicarbonate in Zostera marina Is Reduced by Inhibitors of Mitochondrial ATPase and Electron Transport1  

PubMed Central

When Zostera marina was irradiated after a period of darkness, initiation of photosynthetic O2 evolution occurred in two phases. During a lag phase, lasting 4 to 5 min, photosynthesis was supported by a diffusive entry of CO2. Photosynthesis then rapidly increased to its full rate. Tris buffer, at a concentration of 50 mm, completely inhibited this increase without affecting CO2-supported photosynthesis during the lag phase. These results verify that the increase in photosynthesis after the lag phase depended on an activation of bicarbonate (HCO3?) utilization through acid zones generated by proton pumps located to the outer cell membrane. In similar experiments, 6.25 ?m of the mitochondrial ATPase blocker oligomycin inhibited photosynthetic HCO3? utilization by more than 60%. Antimycin A, a selective blocker of mitochondrial electron transport, caused a similar inhibition of HCO3? utilization. Measurements at elevated CO2 concentrations verified that neither oligomycin nor antimycin interfered with linear photosynthetic electron transport or with CO2 fixation. Thus, a major part of the ATP used for the generation of acid zones involved in HCO3? utilization in Z. marina was derived from mitochondrial respiration. PMID:18434609

Carr, Herman; Axelsson, Lennart

2008-01-01

193

208 Biochimicaet BiophysicaActa, 936(1988)208-214 Kinetics of the bicarbonate effect and the number of bicarbonate-binding sites  

E-print Network

effect and the number of bicarbonate-binding sites in thylakoid membranes Danny J. Blubangh and Govindjee1988) Keywords: PhotosystemI1; Bicarbonateeffect;Carbondioxide;Electrontransport; Bindingsite;Thylakoid; (Spinach) In HCOf-depleted thylakoids in which the basal activity was less than 7% of the fully restored

Govindjee

194

Plasma exchange successfully treats central pontine myelinolysis after acute hypernatremia from intravenous sodium bicarbonate therapy  

PubMed Central

Background Osmotic demyelination syndrome (ODS) primarily occurs after rapid correction of severe hyponatremia. There are no proven effective therapies for ODS, but we describe the first case showing the successful treatment of central pontine myelinolysis (CPM) by plasma exchange, which occurred after rapid development of hypernatremia from intravenous sodium bicarbonate therapy. Case presentation A 40-year-old woman presented with general weakness, hypokalemia, and metabolic acidosis. The patient was treated with oral and intravenous potassium chloride, along with intravenous sodium bicarbonate. Although her bicarbonate deficit was 365 mEq, we treated her with an overdose of intravenous sodium bicarbonate, 480 mEq for 24 hours, due to the severity of her acidemia and her altered mental status. The next day, she developed hypernatremia with serum sodium levels rising from 142.8 mEq/L to 172.8 mEq/L. Six days after developing hypernatremia, she exhibited tetraparesis, drooling, difficulty swallowing, and dysarthria, and a brain MRI revealed high signal intensity in the central pons with sparing of the peripheral portion, suggesting CPM. We diagnosed her with CPM associated with the rapid development of hypernatremia after intravenous sodium bicarbonate therapy and treated her with plasma exchange. After two consecutive plasma exchange sessions, her neurologic symptoms were markedly improved except for mild diplopia. After the plasma exchange sessions, we examined the patient to determine the reason for her symptoms upon presentation to the hospital. She had normal anion gap metabolic acidosis, low blood bicarbonate levels, a urine pH of 6.5, and a calyceal stone in her left kidney. We performed a sodium bicarbonate loading test and diagnosed distal renal tubular acidosis (RTA). We also found that she had Sjögren’s syndrome after a positive screen for anti-Lo, anti-Ra, and after the results of Schirmer’s test and a lower lip biopsy. She was discharged and treated as an outpatient with oral sodium bicarbonate and potassium chloride. Conclusion This case indicates that serum sodium concentrations should be carefully monitored in patients with distal RTA receiving intravenous sodium bicarbonate therapy. We should keep in mind that acute hypernatremia and CPM can be associated with intravenous sodium bicarbonate therapy, and that CPM due to acute hypernatremia may be effectively treated with plasma exchange. PMID:24708786

2014-01-01

195

40 CFR 180.473 - Glufosinate ammonium; tolerances for residues.  

Code of Federal Regulations, 2012 CFR

...General . Tolerances are established for residues of the herbicide glufosinate ammonium, including its metabolites...are established for indirect or inadvertent residues of the herbicide glufosinate ammonium, including...

2012-07-01

196

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

2013-10-15

197

Phase diagram of ammonium nitrate  

SciTech Connect

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

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

2013-12-07

198

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. PMID:2621626

Brahm, J; Wimberley, P D

1989-01-01

199

21 CFR 184.1143 - Ammonium sulfate.  

Code of Federal Regulations, 2010 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...

2010-04-01

200

21 CFR 184.1143 - Ammonium sulfate.  

...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...

2014-04-01

201

Laser velocimeter (autocovariance) buffer interface  

NASA Technical Reports Server (NTRS)

A laser velocimeter (autocovariance) buffer interface (LVABI) was developed to serve as the interface between three laser velocimeter high speed burst counters and a minicomputer. A functional description is presented of the instrument and its unique features which allow the studies of flow velocity vector analysis, turbulence power spectra, and conditional sampling of other phenomena. Typical applications of the laser velocimeter using the LVABI are presented to illustrate its various capabilities.

Clemmons, J. I., Jr.

1981-01-01

202

Acute sodium bicarbonate loading has negligible effects on resting and exercise blood pressure but causes gastrointestinal distress  

PubMed Central

Oral ingestion of sodium bicarbonate (bicarbonate loading) has acute ergogenic effects on short-duration, high-intensity exercise. Because sodium bicarbonate is 27% sodium, ergogenic doses (i.e. 300 mg·kg?1) result in sodium intakes well above the Dietary Reference Intakes upper limit of 2300 mg/day. Therefore, it is conceivable that bicarbonate loading could have hypertensive effects. Therefore, we performed a double-blind cross-over trial to evaluate the hypothesis that bicarbonate loading increases resting and exercise blood pressure (BP). A secondary hypothesis was that bicarbonate loading causes gastrointestinal distress. Eleven endurance-trained men and women (exercise frequency, 4.6±0.4 sessions/wk; duration, 65±6 min/session) underwent testing on two occasions in random sequence: once after bicarbonate loading (300 mg·kg?1) and once after placebo ingestion. BP and heart rate (HR) were measured before bicarbonate or placebo consumption, 30 minutes after consumption, during 20 min of steady state submaximal cycling exercise, and during recovery. Bicarbonate loading did not affect systolic BP during rest, exercise, or recovery (p=0.38 for main treatment effect). However, it resulted in modestly higher diastolic BP (main treatment effect, +3.3±1.1 mmHg, p=0.01) and higher HR (main treatment effect, +10.1±2.4 bpm, p=0.002). Global ratings of gastrointestinal distress severity (0–10 scale) were greater after bicarbonate ingestion (5.1±0.5 vs. 0.5±0.2, p<0.0001). Furthermore, 10 of the 11 subjects (91%) experienced diarrhea, 64% experience bloating and thirst, and 45% experienced nausea after bicarbonate loading. In conclusion, although a single, ergogenic dose of sodium bicarbonate does not appear to have acute, clinically important effects on resting or exercise BP, it does cause substantial GI distress. PMID:23746564

Kahle, Laura E.; Kelly, Patrick V.; Eliot, Kathrin A.; Weiss, Edward P.

2013-01-01

203

Acute sodium bicarbonate loading has negligible effects on resting and exercise blood pressure but causes gastrointestinal distress.  

PubMed

Oral ingestion of sodium bicarbonate (bicarbonate loading) has acute ergogenic effects on short-duration, high-intensity exercise. Because sodium bicarbonate is 27% sodium, ergogenic doses (ie, 300 mg?kg?¹) result in sodium intakes well above the Dietary Reference Intakes upper limit of 2300 mg/day. Therefore, it is conceivable that bicarbonate loading could have hypertensive effects. Therefore, we performed a double-blind crossover trial to evaluate the hypothesis that bicarbonate loading increases resting and exercise blood pressure (BP). A secondary hypothesis was that bicarbonate loading causes gastrointestinal distress. Eleven endurance-trained men and women (exercise frequency, 4.6 ± 0.4 sessions/wk; duration, 65 ± 6 min/session) underwent testing on two occasions in random sequence: once after bicarbonate loading (300 mg?kg?¹) and once after placebo ingestion. BP and heart rate were measured before bicarbonate or placebo consumption, 30 minutes after consumption, during 20 min of steady state submaximal cycling exercise, and during recovery. Bicarbonate loading did not affect systolic BP during rest, exercise, or recovery (P = .38 for main treatment effect). However, it resulted in modestly higher diastolic BP (main treatment effect, +3.3 ± 1.1 mmHg, P = .01) and higher heart rate (main treatment effect, +10.1 ± 2.4 beats per minute, P = .002). Global ratings of gastrointestinal distress severity (0-10 scale) were greater after bicarbonate ingestion (5.1 ± 0.5 vs 0.5 ± 0.2, P < .0001). Furthermore, 10 of the 11 subjects (91%) experienced diarrhea, 64% experience bloating and thirst, and 45% experienced nausea after bicarbonate loading. In conclusion, although a single, ergogenic dose of sodium bicarbonate does not appear to have acute, clinically important effects on resting or exercise BP, it does cause substantial gastrointestinal distress. PMID:23746564

Kahle, Laura E; Kelly, Patrick V; Eliot, Kathrin A; Weiss, Edward P

2013-06-01

204

Bicarbonate Increases Binding Affinity of Vibrio cholerae ToxT to Virulence Gene Promoters.  

PubMed

The major Vibrio cholerae virulence gene transcription activator, ToxT, is responsible for the production of the diarrhea-inducing cholera toxin (CT) and the major colonization factor, toxin coregulated pilus (TCP). In addition to the two primary virulence factors mentioned, ToxT is responsible for the activation of accessory virulence genes, such as aldA, tagA, acfA, acfD, tcpI, and tarAB. ToxT activity is negatively modulated by bile and unsaturated fatty acids found in the upper small intestine. Conversely, previous work identified another intestinal signal, bicarbonate, which enhances the ability of ToxT to activate production of CT and TCP. The work presented here further elucidates the mechanism for the enhancement of ToxT activity by bicarbonate. Bicarbonate was found to increase the activation of ToxT-dependent accessory virulence promoters in addition to those that produce CT and TCP. Bicarbonate is taken up into the V. cholerae cell, where it positively affects ToxT activity by increasing DNA binding affinity for the virulence gene promoters that ToxT activates regardless of toxbox configuration. The increase in ToxT binding affinity in the presence of bicarbonate explains the elevated level of virulence gene transcription. PMID:25182489

Thomson, Joshua J; Withey, Jeffrey H

2014-11-15

205

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

PubMed

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

Newbrun, E

1997-01-01

206

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

PubMed

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

Newbrun, E

1996-01-01

207

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

NASA Astrophysics Data System (ADS)

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

Nishimura, Toshiyasu; Dong, Junpha

208

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

PubMed Central

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

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

1987-01-01

209

Ion-pair hollow-fiber liquid-phase microextraction of the quaternary ammonium surfactant dicocodimethylammonium chloride.  

PubMed

A two-phase hollow-fiber (HF) liquid-phase microextraction (LPME) method was developed for determination of a quaternary ammonium compound surfactant, dicocodimethylammonium chloride, in aqueous samples. The porous HF was fixed on a metal rod support and was impregnated with approximately 6.6 microL of organic extractant, which was immobilized in the HF pores. Surfactant extraction was facilitated by addition of carboxylic acid to the sample forming neutral ion pairs with the quaternary ammonium compound. After extraction, the analyte was transferred from the organic extractant in the fiber pores by dissolving the 1-octanol into 100 microL methanol. The methanol extract was analyzed by liquid chromatography-mass spectrometry. The method was optimized (with optimized parameters in brackets) with regard to type of organic extractant (1-octanol), fiber length (2 cm), choice and concentration of anionic carrier (600 microg L(-1) octanoate), procedure of transfer to methanol (15-min sonication), sample volume (250 mL), extraction time (17 h), pH (10), and ionic strength (50 mM carbonate). Aspects influencing repeatability in LPME of (quaternary ammonium) surfactants are discussed. The enrichment factor achieved in 250-mL carbonate buffer was around 400. Due to matrix effects, the enrichment factors achieved when industrial process water was analyzed were 120 or about 30% of that in carbonate buffer. Detection limits of 0.3 microg L(-1) in carbonate buffer and 0.9 microg L(-1) in industrial process water were obtained. If the studied compound is seen as a model substance representing quaternary dialkylated dimethylated ammonium surfactants in general, the developed method may be applied to other quaternary ammonium surfactants. PMID:19050857

Hultgren, Sofie; Larsson, Niklas; Nilsson, Bo F; Jönsson, Jan Ake

2009-02-01

210

Study of Buffer Size in Internet Routers.  

National Technical Information Service (NTIS)

In this report, we summarize the results of our small buffer project. The goals of the project were (1) to model the behavior of TCP in a network where the routers have very small buffers, (2) to determine a rule for sizing buffers in such networks, and (...

D. Towsley

2006-01-01

211

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

212

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...

213

Doped LZO buffer layers for laminated conductors  

DOEpatents

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

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

2010-03-23

214

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

215

Combined Input-Crosspoint Buffered Packet Switch with Flexible Access to Crosspoints Buffers  

E-print Network

1 Combined Input-Crosspoint Buffered Packet Switch with Flexible Access to Crosspoints Buffers by the adopted switch architecture. Combined input- crosspoint buffered (CICB) packet switches are being must be proportional to the number of ports and crosspoint buffer size, which is set by the distance

Rojas-Cessa, Roberto

216

Floor Buffer Guidelines Floor buffers can expose employees to noise, hazardous materials, and hazards related to  

E-print Network

Floor Buffer Guidelines Floor buffers can expose employees to noise, hazardous materials of asbestos fibers. 7. Do not operate a floor buffer with an abrasive pad on un-waxed or unfinished floors ppm while employees were operating buffers. No specific precautions are recommended. Carbon Monoxide

de Lijser, Peter

217

USDA Forest Service Gen. Tech. Rep. PSW-GTR-168. 1998. 71 Buffering the Buffer1  

E-print Network

USDA Forest Service Gen. Tech. Rep. PSW-GTR-168. 1998. 71 Buffering the Buffer1 Leslie M. Reid2 and Sue Hilton3 Abstract:Abstract:Abstract:Abstract:Abstract: Riparian buffer strips are a widely accepted in forested areas, but controversy persists over how wide a buffer strip is necessary. The physical integrity

Standiford, Richard B.

218

Multi-objective Buffer Allocation Cruz, van Woensel & Smith Buffer and throughput trade-offs in  

E-print Network

Multi-objective Buffer Allocation Cruz, van Woensel & Smith Buffer and throughput trade-offs in M. For example, one conflicting pair of objectives includes first minimizing the overall number of buffers and then maximizing throughput. In this paper, we present an original methodology to solve a buffer alloca- tion

Cruz, Frederico

219

An Time Algorithm for Optimal Buffer Insertion with b Buffer Types *  

E-print Network

An Time Algorithm for Optimal Buffer Insertion with b Buffer Types * Zhuo Dept. of Electrical Engineering Texas University College Station,Texas 77843,USA. zhuoli@ee.tamu.edu Abstract Buffer insertion is apopular technique to reduce the in- terconnect delay. The classic buffer insertion algorithm of van has

Paris-Sud XI, Université de

220

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

E-print Network

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

Cruz, Frederico

221

Networks, Buffer Allocation Problem typeset May 18, 2004 Smith & Cruz The Buffer Allocation Problem for  

E-print Network

Networks, Buffer Allocation Problem typeset May 18, 2004 Smith & Cruz The Buffer Allocation Problem for General Finite Buffer Queueing Networks J. MacGregor Smith F. R. B. Cruz e-mail: jmsmith@ecs.umass.edu e-mail: fcruz@ufmg.br May 18, 2004 Abstract -- The Buffer Allocation Problem (BAP) is a difficult stochastic

Cruz, Frederico

222

Buffered Communication Analysis in Distributed Multiparty Sessions  

NASA Astrophysics Data System (ADS)

Many communication-centred systems today rely on asynchronous messaging among distributed peers to make efficient use of parallel execution and resource access. With such asynchrony, the communication buffers can happen to grow inconsiderately over time. This paper proposes a static verification methodology based on multiparty session types which can efficiently compute the upper bounds on buffer sizes. Our analysis relies on a uniform causality audit of the entire collaboration pattern - an examination that is not always possible from each end-point type. We extend this method to design algorithms that allocate communication channels in order to optimise the memory requirements of session executions. From these analyses, we propose two refinements methods which respect buffer bounds: a global protocol refinement that automatically inserts confirmation messages to guarantee stipulated buffer sizes and a local protocol refinement to optimise asynchronous messaging without buffer overflow. Finally our work is applied to overcome a buffer overflow problem of the multi-buffering algorithm.

Deniélou, Pierre-Malo; Yoshida, Nobuko

223

Effect of reduced renal mass on ammonium handling and net acid formation by the superficial and juxtamedullary nephron of the rat. Evidence for impaired reentrapment rather than decreased production of ammonium in the acidosis of uremia.  

PubMed

Papillary and surface micropuncture were used to study the handling of ammonium and the formation of net acid by surface nephrons, deep nephrons, and the terminal segment of collecting duct (CD) after renal mass was reduced by two-thirds. Net acid excretion by the remnant kidney (RK) was significantly reduced, averaging 794+/-81 neq/min (SE) compared with 1,220+/-105 neq/min after sham operation (P < 0.001), due to a decrease in ammonium excretion (494+/-54 vs. 871+/-79 nmol/min in controls, P < 0.001). Urinary pH and titratable acid excretion were not different in the two groups of animals. After RK formation, ammonium delivery to the end of the proximal tubule increased nearly threefold and averaged 66.2+/-5.6 compared with 18.4+/-2.9 pmol/min in controls, (P < 0.001). This greater delivery of ammonium was primarily due to renal tubule entry rather than to changes in the filtered load and was only partially related to the differences in flow rate. Ammonium processing by deep nephrons was profoundly affected by a reduction in renal mass. Although absolute delivery of ammonium was greater to the bend of Henle's loop (BHL), the difference could be accounted for on the basis of an increase in nephron size. Thus, fractional delivery (FD(NH+4)) to this site was not different for the two groups of animals, averaging 1,567+/-180% in controls and 1,400+/-181% in the group with the RK. Hydrogen secretion in the proximal segments of deep and surface nephrons did not increase in proportion to the decrease in renal mass and as a consequence bicarbonate delivery to the end of the proximal tubule of surface nephrons and to the BHL of deep nephrons was increased. When renal mass was reduced FD(NH+4) to the base of the terminal CD doubled but did not change by the tip. In both groups FD(NH+4) to the base of the CD was greater than to the end of the distal tubule. However, the increase was the same. On the other hand, the increase in the net acid index between the end of the distal tubule and the base of the CD was profoundly greater in rats with an RK. This difference was primarily due to bicarbonate reabsorption rather than enhanced ammonium reentry. Indeed, >400% of the fractional ammonium delivered to the end of the proximal tubule was lost from the tubule fluid. The data suggest that the decrease in acid excretion by the RK is due to two factors. First, hydrogen secretion in the proximal segments of both nephron populations fails to increase in the proportion to the reduction in renal mass. Second, a reduced reentrapment of ammonia, rather than its impaired production, causes ammonium excretion to decrease. PMID:6863538

Buerkert, J; Martin, D; Trigg, D; Simon, E

1983-06-01

224

Effect of Beta-Alanine With and Without Sodium Bicarbonate on 2,000-m Rowing Performance.  

PubMed

Purpose: To examine the effect of beta-alanine only and beta-alanine with sodium bicarbonate supplementation on 2,000-m rowing performance. Methods: Twenty well-trained rowers (age 23 ± 4 y; height 1.85 ± 0.08 m; body mass 82.5 ± 8.9 kg) were assigned to either a placebo or beta-alanine (6.4 g·d-1 for 4 weeks) group. A 2,000-m rowing time trial (TT) was performed before supplementation (Baseline) and after 28 and 30 days of supplementation. The post supplementation trials involved supplementation with either maltodextrin or sodium bicarbonate in a double-blind, crossover design, creating four study conditions (placebo with maltodextrin; placebo with sodium bicarbonate; beta-alanine with maltodextrin; beta-alanine with sodium bicarbonate). Blood lactate, pH, bicarbonate, and base excess were measured pre-TT, immediately post-TT and at TT+5 min. Performance data were analyzed using magnitude based inferences. Results: Beta-alanine supplementation was very likely to be beneficial to 2,000-m rowing performance (6.4 ± 8.1 s effect compared with placebo), with the effect of sodium bicarbonate having a likely benefit (3.2 ± 8.8 s). There was a small (1.1 ± 5.6 s) but possibly beneficial additional effect when combining chronic beta-alanine supplementation with acute sodium bicarbonate supplementation compared with chronic beta-alanine supplementation alone. Sodium bicarbonate ingestion led to increases in plasma pH, base excess, bicarbonate, and lactate concentrations. Conclusions: Both chronic beta-alanine and acute sodium bicarbonate supplementation alone had positive effects on 2,000-m rowing performance. The addition of acute sodium bicarbonate to chronic beta-alanine supplementation may further enhance rowing performance. PMID:24172994

Hobson, Ruth M; Harris, Roger C; Martin, Dan; Smith, Perry; Macklin, Ben; Gualano, Bruno; Sale, Craig

2013-10-01

225

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

226

Buffered banks in multiprocessor systems  

SciTech Connect

A memory design based on logical banks is analyzed for shared memory multiprocessor systems. In this design, each physical bank is replaced by a logical bank consisting of a fast register and subbanks of slower memory. The subbanks are buffered by input and output queues which substantially reduce the effective cycle time when the reference rate is below saturation. The principal contribution of this work is the development of a simple analytical model which leads to scaling relationships among the efficiency, the bank cycle time, the number of processors, the size of the buffers, and the granularity of the banks. These scaling relationships imply that if the interconnection network has sufficient bandwidth to support efficient access using high-speed memory, then lower-speed memory can be substituted with little additional interconnection cost. The scaling relationships are shown to hold for a full datapath vector simulation based on the Cray Y-MP architecture. The model is used to develop design criteria for a system which supports 192 independent reference streams, and the performance of this system is evaluated by simulation over a range of loading conditions. 22 refs.

Robbins, K.A.; Robbins, S. [Univ. of Texas, San Antonio, TX (United States)] [Univ. of Texas, San Antonio, TX (United States)

1995-04-01

227

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

228

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

2007-02-01

229

Tetra-methyl-ammonium hydrogen terephthalate.  

PubMed

The asymmetric unit of the title salt, C(4)H(12)N(+)·C(8)H(5)O(4) (-), contains one half of a tetra-methyl-ammonium cation and one half of a hydrogen terephthalate monoanion. The N atom of the ammonium cation lies on a twofold rotation axis and the centre of mass of the terephthalate anion is on a centre of inversion. In the crystal, the centrosymmetric terephthalate ions are linked by a very short symmetric O-H?O hydrogen bond [O?O = 2.4610?(19)?Å] into a one-dimensional polymeric chain along [1-12]. The tetra-methyl-ammonium cations and terephthalate anions are then connected through a pair of bifurcated acceptor C-H?O hydrogen bonds, generating a three-dimensional supra-molecular network. The carboxyl-ate groups at both ends of the terephthalate anion are charge-shared with an equal probability of 0.5. PMID:23125785

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

2012-10-01

230

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

E-print Network

[2,3] before the latter exchanges with a PQ molecule [4]. On the electron donor side, four positive effect," Quinone," (Spinach chloroplasO In this paper, we present the first measurements, after bicarbonate depletion and its readdition. The effects of bicarbonate depletion on the S2Q ~ (or

Govindjee

231

Intestinal bicarbonate secretion by marine teleost fish--why and how? Rod W. Wilsona,*, Jonathan M. Wilsonb  

E-print Network

Intestinal fluids of most marine teleosts are alkaline (pH 8.4­9.0) and contain high levels of HCO3 � are discussed. One consequence of the luminal alkalinity and high bicarbonate concentrations is precipitation; Osmoregulation; pH-stat titration; Water absorption; Chloride­bicarbonate exchange 1. Introduction Marine teleost

Grosell, Martin

232

Optimization of buffer injection for the effective bioremediation of chlorinated solvents in aquifers  

NASA Astrophysics Data System (ADS)

Various techniques have been proposed to enhance biologically-mediated reductive dechlorination of chlorinated solvents in the subsurface, including the addition of fermentable organic substrate for the generation of H2 as an electron donor. One rate-limiting factor for enhanced dechlorination is the pore fluid pH. Organic acids and H+ ions accumulate in dechlorination zones, generating unfavorable conditions for microbial activity (pH < 6.5). The pH variation is a nonlinear function of the amount of reduced chlorinated solvents, and is affected by the organic material fermented, the chemical composition of the pore fluid and the soil's buffering capacity. Consequently, in some cases enhanced remediation schemes rely on buffer injection (e.g., bicarbonate) to alleviate this problem, particularly in the presence of solvent nonaqueous phase liquid (NAPL) source zones. However, the amount of buffer required - particularly in complex, evolving biogeochemical environments - is not well understood. To investigate this question, this work builds upon a geochemical numerical model (Robinson et al., Science of the Total Environment, submitted), which computes the amount of additional buffer required to maintain the pH at a level suitable for bacterial activity for batch systems. The batch model was coupled to a groundwater flow/solute transport/chemical reaction simulator to permit buffer optimization computations within the context of flowing systems exhibiting heterogeneous hydraulic, physical and chemical properties. A suite of simulations was conducted in which buffer optimization was examined within the bounds of the minimum concentration necessary to sustain a pH favorable to microbial activity and the maximum concentration to avoid excessively high pH values (also not suitable to bacterial activity) and mineral precipitation (e.g., calcite, which may lead to pore-clogging). These simulations include an examination of the sensitivity of this buffer concentration range to aquifer heterogeneity and groundwater velocity. This work is part of SABRE (Source Area BioREmediation), a collaborative international research project that aims to evaluate and improve enhanced bioremediation of chlorinated solvent source zones. In this context, numerical simulations are supporting the upscaling of the technique, including identifying the most appropriate buffer injection strategies for field applications

Brovelli, A.; Robinson, C.; Barry, A.; Kouznetsova, I.; Gerhard, J.

2008-12-01

233

On the evaporation of ammonium sulfate solution  

PubMed Central

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

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

2009-01-01

234

Supercritical water oxidation of ammonium picrate  

SciTech Connect

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

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

1994-11-01

235

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

236

Molecular doping of graphene with ammonium groups  

NASA Astrophysics Data System (ADS)

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.; Pantelides, S. T.

2012-04-01

237

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

238

Plant Physiol. (1973) 52, 119-123 Bicarbonate Ion as a Critical Factor in Photosynthetic  

E-print Network

, University of Illinois, Urbana, Illinois 61801 ABSTRACT Bicarbonate ion, not dissolved CO2 gas, is shown (Zea mays; single cross hybrid GSC50) plants were grown in vermiculite under artificial light (using effect much more consistent. After light treatment, the harvested leaves were cooled in ice water

Govindjee

239

Regulation of photosynthetic electronflow in isolated chloroplasts by bicarbonate, formate and herbicides  

Microsoft Academic Search

This thesis describes some efforts that were made to gain a better understanding of the processes involved in the regulation of photosynthetic electron flow by bicarbonate, formate and herbicides in chloroplasts. In the past decade a large amount of research has been devoted to get insight into the mechanism of herbicide action on electron flow at the acceptor side of

J. F. H. Snel

1985-01-01

240

Activity coefficients of bicarbonate, carbonate and calcium ions in sea water  

Microsoft Academic Search

Measurements of pH of sea water samples equilibrated with known partial pressures of CO 2 and with calcite and aragonite have enabled the determination of molal activity coefficient for bicarbonate, carbonate, and calcium ions in two sea water samples at 25°C and 1 atm total pressure. Results are: For standard artificial sea water (chlorinity = 19.0 , titration alkalinity =

Robert A. Berner

1965-01-01

241

A bicarbonate-alkaline mineral water protects from ethanol-induced hemorrhagic gastric lesions in mice.  

PubMed

Ingestion of elevated amounts of ethanol in humans and rodents induces hemorrhagic gastric lesions, at least in part by increasing oxidative stress. The present study was undertaken in order to evaluate the influence of a bicarbonate-alkaline mineral water (Uliveto on ethanol-induced hemorrhagic gastric lesions in mice. Lesions were evaluated by both macroscopic and microscopic analysis. In a first set of experiments, mice were allowed to drink Uliveto or reference water ad libitum until 3 h prior to intragastric (i.g.) ethanol (23 ml/kg) administration. Neither Uliveto nor reference water did afford any protection. In a second set of experiments, acute exposure to reference water (35 ml/kg, i.g.), given 30 min before ethanol, did not inhibit gastric lesions. However, administration of the same amount of Uliveto caused a remarkable reduction in ethanol-evoked gastric lesions. Ethanol administration increased 4-hydroxy-2-nonenal levels, a byproduct of oxidative stress, in the luminal part of the gastric mucosa. This response was substantially reduced by about 70% by Uliveto, but not by reference water. Reference water, added with the bicarbonate content, present in the Uliveto water, protected against ethanol-induced lesions. Thus, acute pre-exposure to bicarbonate-alkaline mineral water (Uliveto) protects from both oxidative stress and hemorrhagic gastric lesions caused by ethanol. The elevated bicarbonate content of Uliveto likely accounts for the protection against ethanol-induced gastric injury. PMID:20686225

Nassini, Romina; Andrè, Eunice; Gazzieri, David; De Siena, Gaetano; Zanasi, Alessandro; Geppetti, Pierangelo; Materazzi, Serena

2010-01-01

242

Effects of riparian forest buffers on in-stream nutrient retention in agricultural catchments.  

PubMed

In northeastern Austria, marshlands have been turned into the most productive arable land of the country. As a result, most headwater streams show structurally degraded channels, lacking riparian buffer zones, which are heavily loaded with nutrients from the surrounding crop fields. The present study examines whether longitudinally restricted riparian forest buffers can enhance the in-stream nutrient retention in nutrient-enriched headwater streams. We estimated nutrient uptake from pairwise, short-term addition experiments with NH, NH, PO, and NaCl within reaches with riparian forest buffers (RFB) and degraded reaches (DEG) of the same streams. Riparian forest buffers originated from the conservation of the pristine vegetation or from restoration measures. Hydrologic retention was calculated with the model OTIS-P on the basis of conductivity break-through curves from the salt injections. A significant increase in surface transient storage was revealed in pristine and restored RFB reaches compared with DEG reaches due to the longitudinal step-pool pattern and the frequent occurrence of woody debris on the channel bed. Ammonium uptake lengths were significantly shorter in RFB reaches than in DEG reaches, resulting from the higher hydrologic retention. Uptake velocities did not differ significantly between RFB and DEG reaches, indicating that riparian forest buffers did not affect the biochemical nutrient demand. Uptake of NH was mainly driven by autotrophs. Net PO uptake was not affected by riparian forest buffers. The study shows that the physical and biogeochemical effects of riparian forest buffers on the in-stream nutrient retention are limited in the case of highly eutrophic streams. PMID:22370399

Weigelhofer, Gabriele; Fuchsberger, Jennifer; Teufl, Bernadette; Welti, Nina; Hein, Thomas

2012-01-01

243

Melatonin: Buffering the Immune System  

PubMed Central

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

Carrillo-Vico, Antonio; Lardone, Patricia J.; Alvarez-Sanchez, Nuria; Rodriguez-Rodriguez, Ana; Guerrero, Juan M.

2013-01-01

244

Buffer strips in composites at elevated temperature  

NASA Technical Reports Server (NTRS)

The composite material 'buffer strip' concept is presently investigated at elevated temperatures for the case of graphite/polyimide buffer strip panels using a (45/0/45/90)2S layup, where the buffer strip material was 0-deg S-glass/polyimide. Each panel was loaded in tension until it failed, and radiographs and crack opening displacements were recorded during the tests to determine fracture onset, fracture arrest, and the extent of damage in the buffer strip after crack arrest. At 177 + or - 3 C, the buffer strips increased the panel strength by at least 40 percent in comparison with panels without buffer strips. Compared to similar panels tested at room temperature, those tested at elevated temperature had lower residual strengths, but higher failure strains.

Bigelow, C. A.

1983-01-01

245

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. PMID:3729341

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

1986-01-01

246

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."

247

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

2013-12-01

248

All-optical buffering for DPSK packets  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

249

Original article Ammonium assimilation and ureide metabolism  

E-print Network

during the vegeta- tive and two during the reproductive period. Salinity reduced plant dry weight by 25 2000; revised 17 July 2001; accepted 21 August 2001) Abstract ­ The effect of salinity on ammonium-assimilation enzymes, as well as on the enzymes of purine catabolism, was studied in root nodules of common bean plants

Paris-Sud XI, Université de

250

Third Order Elastic Constants of Ammonium Chloride  

Microsoft Academic Search

Sound velocities along several directions in ammonium chloride crystals have been measured under hydrostatic and uniaxial pressures by means of an ultrasonic method. Second order elastic constants and their pressure derivatives were evaluated in the vicinity of the phase transition point in disordered phase, and third order elastic constants were calculated from the data. It was found that the absolute

Haruyasu Yamashita; Itaru Tatsuzaki

1984-01-01

251

Diamond Head Revisited with Ammonium Dichromate.  

ERIC Educational Resources Information Center

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

Arrigoni, Edward

1981-01-01

252

Modelling Ammonium Transporters in Arbuscular Mycorrhiza Symbiosis  

E-print Network

Modelling Ammonium Transporters in Arbuscular Mycorrhiza Symbiosis Mario Coppo1 , Ferruccio Damiani, the most wide-spread plant-fungus symbiosis on earth. Inves- tigating this kind of symbiosis is considered), the most widespread symbiosis between plants and fungi, got into the focus of research because of its

Troina, Angelo

253

Effect of ammonium thilosulfate and dicyandiamide on residual ammonium in fertilizer bands  

Microsoft Academic Search

Ammonium thiosulfate (ATS, 12–0–0–26S) and dicyandiamide (DCD, 66–0–0) are fertilizer products that also inhibit nitrification. It has also been proposed that ATS can improve the nitrification inhibition properties of DCD. The purpose of this research was to compare the effects of ATS, DCD, and ATS\\/DCD mixtures on the nitrification of banded urea solution or urea?ammonium nitrate (UAN) under laboratory, field

R. J. Goos; B. E. Johnson

1992-01-01

254

Buffer Preparation (Gozani Lab) 1. 1 M Tris-HCl Buffers  

E-print Network

Buffer Preparation (Gozani Lab) 1. 1 M Tris-HCl Buffers pH Volume (L) TrisBase (g) HCl (ml) pH 7 by NaOH is essential for solubility. Autoclavable. 3. TAE DNA Electrophoresis Buffer (50 X) (2 M Tris, add 400 ml 50X buffer into 19.6 L ddH2O. 4. SDS-PAGE Gel Solutions Vol (L) Tris (g) HCl (ml) 10% SDS

Gozani, Or

255

Copper corrosion in buffered and non-buffered synthetic seawater: a comparative study  

Microsoft Academic Search

The electrochemical behaviour of copper in neutral buffered and non-buffered synthetic seawater and in pure chloride solutions has been studied by cyclic voltammetry, weight loss measurements, open circuit potential and scanning electron microscopy (SEM). Values of the repassivation potentials of Cu in non-buffered and buffered synthetic seawater, at 50 mV s -1, were 0.12 and 0.46 V vs. SCE, respectively. The sharpness, heights

JoãoPedro Ferreira; JoãoAlexandre Rodrigues; InêsTeodoraElias da Fonseca

2004-01-01

256

Muscarinic M1 receptor inhibition reduces gastroduodenal bicarbonate secretion and promotes gastric prostaglandin E2 synthesis in healthy volunteers.  

PubMed Central

The selective muscarinic M1 receptor antagonist, pirenzepine, considerably stimulates duodenal mucosal bicarbonate secretion in the rat and increases gastric luminal release of prostaglandin E2 (PGE2) in humans. This study, therefore, looked at the effect of pirenzepine on bicarbonate secretion and luminal output of PGE2 into the stomach and the duodenum of nine healthy volunteers using a new technique permitting simultaneous measurements. In the stomach modified sham feeding increased bicarbonate secretion from 382 (62) mumol/h (mean (SEM)) to 959 (224) mumol/h (p < 0.02). In the duodenum modified sham feeding and acid exposure (HCl 0.1 M; 20 ml; 5 min) of the duodenal bulb increased mucosal bicarbonate secretion from 191 (14) mumol/cm x h to 266 (27) mumol/cm x h (p < 0.02) and 634 (157) mumol/cm x h (p < 0.01), respectively. Pirenzepine (10 mg/h intravenously) reduced basal and vagally stimulated gastric and basal duodenal bicarbonate secretion by about 50% (p < 0.03). In the stomach, but not the duodenum, basal and vagally stimulated PGE2 output increased significantly (p < 0.05) in response to pirenzepine. In conclusion, human gastroduodenal mucosal bicarbonate secretion is regulated by a pirenzepine sensitive mechanism, which is probably cholinergic. The rise in gastric PGE2 output seen in response to M1 receptor inhibition by pirenzepine suggests the existence of a feed back loop secondary to the decrease seen in bicarbonate secretion. PMID:7737558

Mertz-Nielsen, A; Hillings?, J; Eskerod, O; Bukhave, K; Rask-Madsen, J

1995-01-01

257

Contribution of ammonium ions to the lethality and antimetamorphic effects of ammonium perchlorate.  

PubMed

Ammonium perchlorate (AP) is a widespread military waste product in the United States and is a potent thyroid function disruptor in all vertebrates tested thus far. To determine the relative contribution of ammonium ions to the toxicity of AP, we exposed embryonic and larval Xenopus laevis to various concentrations of sodium perchlorate (SP) or ammonium chloride (AC). Ammonium perchlorate was significantly more lethal than SP; 5-d LC50s were 83 and 2,780 mg/L, respectively. To determine whether ammonium ions contribute to the antithyroid effects of AP, we exposed embryonic and larval X. laevis to two sublethal, environmentally relevant concentrations of AP or identical concentrations of AC or SP. At the smaller concentration, only AP delayed metamorphosis and reduced hindlimb growth. Sodium perchlorate and AP, but not AC, prevented metamorphosis and reduced hindlimb growth at the greater concentration. Although AP was slightly more effective in reducing outward manifestations of thyroid disruption, both perchlorate salts, unlike AC, caused profound histopathologic changes in the thyroid. Exposure to the higher concentration of either perchlorate salt produced a feminizing effect, resulting in a skewed sex ratio. We conclude that ammonium ions contribute significantly to the toxicity of AP but not to the direct antithyroid effects of perchlorate. PMID:16629145

Goleman, Wanda L; Carr, James A

2006-04-01

258

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

PubMed Central

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

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

1997-01-01

259

Effects of ammonium compounds on the foliar activity of acifluorfen  

E-print Network

and ammonium sulfate increased the activity of dichlorprop on Stellaria m dia (L. ) Vill. (53) Picloram (4-amino-3, 5, 6-trichloro-2-pyridinecarboxylic acid) has also shown a response to inorganic salts. The addition of ammonium sulfate to picloram spray... and ammonium sulfate increased the activity of dichlorprop on Stellaria m dia (L. ) Vill. (53) Picloram (4-amino-3, 5, 6-trichloro-2-pyridinecarboxylic acid) has also shown a response to inorganic salts. The addition of ammonium sulfate to picloram spray...

Schaffers, William Clemens

2012-06-07

260

Buffer Management Simulation in ATM Networks  

NASA Technical Reports Server (NTRS)

This paper presents a simulation of a new dynamic buffer allocation management scheme in ATM networks. To achieve this objective, an algorithm that detects congestion and updates the dynamic buffer allocation scheme was developed for the OPNET simulation package via the creation of a new ATM module.

Yaprak, E.; Xiao, Y.; Chronopoulos, A.; Chow, E.; Anneberg, L.

1998-01-01

261

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

262

UNDERSTANDING, DERIVING, AND COMPUTING BUFFER CAPACITY  

EPA Science Inventory

Derivation and systematic calculation of buffer capacity is a topic that seems often to be neglected in chemistry courses and given minimal treatment in most texts. However, buffer capacity is very important in the chemistry of natural waters and potable water. It affects corro...

263

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

264

46 CFR 58.25-45 - Buffers.  

Code of Federal Regulations, 2012 CFR

... Shipping 2 2012-10-01 2012-10-01 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...

2012-10-01

265

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

266

46 CFR 58.25-45 - Buffers.  

Code of Federal Regulations, 2011 CFR

... Shipping 2 2011-10-01 2011-10-01 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...

2011-10-01

267

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

268

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

269

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

270

FIFO Buffer for Asynchronous Data Streams  

NASA Technical Reports Server (NTRS)

Variable-rate, asynchronous data signals from up to four measuring instruments or other sources combined in first-in/first-out (FIFO) buffer for transmission on single channel. Constructed in complementary metal-oxide-semiconductor (CMOS) logic, buffer consumes low power (only 125 mW at 5V) and conforms to aerospace standards of reliability and maintainability.

Bascle, K. P.

1985-01-01

271

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

272

The buffer capacity of airway epithelial secretions.  

PubMed

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

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

2014-01-01

273

Resilience to suicidality: The buffering hypothesis  

Microsoft Academic Search

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

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

2011-01-01

274

Hardware Loop Buffering Scott DiPasquale  

E-print Network

Hardware Loop Buffering Scott DiPasquale Khaled Elmeleegy C.J. Ganier Erik Swanson #12;Problem and Hypothesis n Compilers have more information about loops that they can exploit. n Hardware loop unrolling is highly complex. n Buffering loops reduces instruction count and improves performance with moderate

Rixner, Scott

275

Reconciling Buffer Management with Persistence Optimisations  

E-print Network

'. Object pinning conflicts with the buffer manager's freedom to evict objects from the buffer when, to minimise pinning vs object management conflicts. Optimisation of the write barrier additionally requires management and executing code in the presence of these optimisations and aims to show that collaboration

Hosking, Antony

276

The buffer capacity of airway epithelial secretions  

PubMed Central

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

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

2014-01-01

277

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

278

Ammonium inactivation of nitrate reductase in Lemna minor L  

Microsoft Academic Search

The addition of ammonium to nitrate induced plants of Lemna minor L. brings about a rapid loss in extractable nitrate reductase activity. This inactivation is reversible both in vivo and in vitro. Inhibitors of RNA and protein synthesis do not protect nitrate reductase against ammonium inactivation. It is suggested that factors, in addition to ammonium ions, are components of the

T. O. Orebamjo; G. R. Stewart

1975-01-01

279

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

280

Evaporation of Ammonium Nitrate Aerosol in a Heated Nephelometer  

E-print Network

Evaporation of Ammonium Nitrate Aerosol in a Heated Nephelometer: Implications for Field National Laboratory, Upon, New York, 11973-5000 Ammonium nitrate is a semivolatile aerosol component under scattering coefficient of ammonium nitrate aerosol due to evaporation in a heated nephelometer. Changes

281

Original article Ionic adsorption of ammonium and nitrate on some  

E-print Network

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

Paris-Sud XI, Université de

282

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220...Certain Materials § 148.220 Ammonium nitrate-phosphate fertilizers. (a...containing a maximum of 70 percent of ammonium nitrate and containing a maximum of 0.4...

2011-10-01

283

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220...Certain Materials § 148.220 Ammonium nitrate-phosphate fertilizers. (a...containing a maximum of 70 percent of ammonium nitrate and containing a maximum of 0.4...

2013-10-01

284

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220...Certain Materials § 148.220 Ammonium nitrate-phosphate fertilizers. (a...containing a maximum of 70 percent of ammonium nitrate and containing a maximum of 0.4...

2012-10-01

285

Estimation of bottom ammonium affinity in the New Caledonia lagoon  

Microsoft Academic Search

Ammonium affinity of New Caledonia lagoon benthic communities was measured during the course of 33 in situ enrichment experiments, in order to estimate the contribution of benthos to ammonium fluxes. Ammonium chloride was injected into enclosures pushed into the sediment, in order to obtain a concentration of 20–22 µmol l-1 in the enclosed water which approximated the interstitial water content.

G. Boucher; J. Clavier; C. Garrigue

1994-01-01

286

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

PubMed Central

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

Wang, Mengnan; Zhang, Jiaguang; Yan, Ning

2013-01-01

287

Methane production from bicarbonate and acetate in an anoxic marine sediment  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

288

The different effects of sodium bicarbonate and aluminium hydroxide on the absorption of indomethacin in man.  

PubMed Central

The influence of oral sodium bicarbonate and aluminium hydroxide on the absorption of indomethacin has been studied in normal volunteers. While sodium bicarbonate appeared to increase indomethacin absorption, aluminium hydroxide markedly reduced both the rate and extent of absorption. The buccal absorption of indomethacin over the pH range 5-9 was also studied in normal volunteers, and showed that the percentage absorption increased markedly as the pH was reduced. The clinical importance both of pH-partition and of adsorption are discussed in the context of antacid interactions. It is concluded that caution must be exercised when prescribing an antacid with other orally-administered drugs. PMID:16256

Garnham, J. C.; Kaspi, T.; Kaye, C. M.; Oh, V. M.

1977-01-01

289

Evaluation of ammonium and soluble salts on grass sod production in compost. I. Addition of ammonium or nitrate salts  

Microsoft Academic Search

Inhibitions in seed germination and in plant growth in some composts have been associated with high concentrations of ammonium or soluble salts in the media. This experiment was conducted to determine changes in ammonium and soluble salts in fertilizer?amended compost with time and their impacts on plant growth. Turfgrass (Lolium perenne L.) was seeded into an ammonium?depleted municipal solid waste

Tara A. OBrien; Allen V. Barker

1996-01-01

290

The use of sodium bicarbonate and hydrogen peroxide in periodontal therapy: a review.  

PubMed

The comparative benefits from the use of sodium bicarbonate and hydrogen peroxide over the use of a commercial dentifrice in periodontal therapy is controversial. The consensus of the clinical research indicates that application by patients of sodium bicarbonate and hydrogen peroxide offers no advantage over the preestablished, properly performed home oral hygiene procedures. Any improvements in clinical and microbial parameters generally were attributed to scaling and root planing. The studies that have reported beneficial results with sodium bicarbonate and hydrogen peroxide have used additional antimicrobial agents, concomitant professional application of these substances, and scaling and root planing. In one of these reports, inorganic salts and chloramine-T were delivered subgingivally throughout root-planing procedures, in addition to home application of inorganic salts. Most of these patients also received at least one course of systemic tetracycline therapy. Because this study had no control group, it is impossible to determine whether this program is more effective than are other periodontal therapy programs. A more controlled clinical study involving professional application of sodium bicarbonate, sodium chloride, hydrogen peroxide, and povidone-iodine has shown greater gains in clinical attachment and bone mass than has brushing with toothpaste and water. Again, subgingival scaling and root planing were necessary to attain these results. Because multiple topical agents were applied in both of these reports and systemic antimicrobial agents were used by the Keyes group, it is impossible to determine which agent was responsible for the improvements. Further, professional application may be the crucial factor.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3029203

Amigoni, N A; Johnson, G K; Kalkwarf, K L

1987-02-01

291

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

292

Evidence for a Detrimental Effect of Bicarbonate Therapy in Hypoxic Lactic Acidosis  

Microsoft Academic Search

Lactic acidosis, a clinical syndrome caused by the accumulation of lactic acid, is characterized by lactate concentration in blood greater than 5 mM. Therapy usually consists of intravenous sodium bicarbonate (NaHCO3), but resultant mortality is greater than 60 percent. The metabolic and systemic effects of NaHCO3 therapy of hypoxic lactic acidosis in dogs were studied and compared to the effects

Helmut Graf; William Leach; Allen I. Arieff

1985-01-01

293

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

294

Bicarbonate ingestion has no ergogenic effect on consecutive all out sprint tests in BMX elite cyclists  

Microsoft Academic Search

The aim of the present study was to examine the effect of sodium bicarbonate ingestion on consecutive “all out” sprint tests,\\u000a analyzing the acid–base status and its influence on performance and perceived effort. Ten elite bicycle motocross (BMX) riders\\u000a (20.7 ± 1.4 years, training experience 8–12 years) participated in this study which consisted of two trials. Each trial consisted\\u000a of three consecutive Wingate tests

Mikel Zabala; Ana B. Peinado; Francisco J. Calderón; Javier Sampedro; Manuel J. Castillo; Pedro J. Benito

295

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

Microsoft Academic Search

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

Stephen C. Maberly; Tom V. Madsen

2002-01-01

296

Research notes: Sodium bicarbonate supplementation in diets for guinea fowl raised at high environmental temperatures.  

PubMed

An experiment was designed to verify the effect of dietary NaHCO3 supplementation on performance of guinea fowl raised under high environmental temperatures (23.8 to 33.9 C) and average relative humidity of 78.7%. One hundred and forty guinea fowl in their final period of growth (56 to 84 d of age) were allotted to individual wire cages. Five isocaloric (3,000 kcal ME/kg) 16% CP diets based on corn and soybean meal and containing 0, 0.6, 1.2, 1.8, and 2.4% sodium bicarbonate were fed to the birds. The experiment followed a randomized block design with 28 birds per treatment (14 of each sex) with each bird being considered as one repetition. Results showed that weight gain, feed intake, feed conversion, mortality, blood pH, carcass yield, and carcass composition were not affected (P > 0.05) by dietary sodium bicarbonate supplementation. Weight gain, feed intake, feed conversion, carcass moisture, and fat content, however, were significantly (P < 0.05) affected by sex. Females showed 17.49% better weight gain, 7.16% greater feed intake, and 9.6% better feed conversion than males. These differences were exacerbated at supplementation levels of 1.2 and 1.8% sodium bicarbonate in the diet. Male birds showed carcass moisture values significantly (P < 0.05) greater than those of female birds; the opposite occurred with carcass fat levels. The use of sodium bicarbonate in levels up to 2.4% of the diet did not affect the performance of guinea fowl raised under the environmental conditions registered in this study. PMID:9603359

Fuentes, M F; Zapata, J F; Espíndola, G B; Freitas, E R; Santos, M G; Sousa, F M

1998-05-01

297

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

Microsoft Academic Search

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

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

1985-01-01

298

Water absorption in the proximal tubule: effect of bicarbonate, chloride gradient, and organic solutes.  

PubMed

Simultaneous in vivo capillary and luminal microperfusion studies were performed in the superficial proximal convoluted tubule of the rat to determine the effect of intraluminal bicarbonate, the imposition of a transepithelial chloride gradient, and the addition of organic solutes to the luminal perfusion solution on the rates of water absorption (Jv). The capillary perfusion solution contained NaCl, NaHCO3, and KCl. Perfusion of both capillary and lumen with the same solution resulted in a Jv of 3.01 +/- 0.24 nl/min/mm. Imposition of a transepithelial chloride gradient (equimolar substitution of NaCl for NaHCO3 in the luminal solution) resulted in a Jv of 3.18 +/- 0.21 nl/min/mm (P = NS). Addition of cyanide to both solutions in the presence of a chloride gradient resulted in a significantly lower Jv of 2.21 +/- 0.19 nl/min/mm. Luminal substitution of Na cyclamate for NaHCO3 resulted in a solution containing no bicarbonate and no chloride gradient. Jv averaged 0.34 +/- 0.08 nl/min/mm. Addition of cyanide to the solution totally inhibited Jv. The addition of D-glucose, L-alanine, or both, to luminal solutions containing bicarbonate or in the presence of a chloride gradient did not significantly affect Jv. Addition of both organic solutes to the NaCl-Na cyclamate luminal solution resulted in a significantly higher Jv of 0.77 +/- 0.14 nl/min/mm. These studies indicate that Jv in the rat superficial proximal tubule is influenced by active sodium transport, by the presence of bicarbonate in the lumen, and/or by the imposition of a transepithelial chloride gradient. The organic solutes D-glucose and L-alanine also influence water absorption, but this effect could only be demonstrated under some experimental conditions. PMID:6828448

Sansom, S C; Senekjian, H O; Knight, T F; Frommer, P; Weinman, E J

1983-01-01

299

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

300

Biochemical Responses to True and Bicarbonate-Induced Iron Deficiency in Grapevine Genotypes  

Microsoft Academic Search

Biochemical responses to direct or bicarbonate-induced iron (Fe) deficiency were compared in two Tunisian native grapevine varieties, Khamri (tolerant) and Balta4 (sensitive), and a tolerant rootstock, 140Ru. Woody cuttings of each genotype were irrigated with a nutrient solution containing one of the following: 20 ?M Fe (control), 1 ?M Fe (direct Fe-deficiency), or 20 ?M Fe + 10 mM HCO3

Riadh Ksouri; Sabah Mrah; Mohamed Gharsalli; Mokhtar Lachaâl

2006-01-01

301

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

302

Optimal Buffer Size for Wireless Mesh Networks! INTRODUCTION!  

E-print Network

Optimal Buffer Size for Wireless Mesh Networks! INTRODUCTION! Buffers are used to absorb transient traffic bursts. Very large buffers, which are common nowadays, lead to long queuing delays. On the other hand, very small buffers may result in network under-utilization. Our goal is to determine buffer size

Chaudhuri, Surajit

303

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

304

DETECTION OF THE AMMONIUM ION IN SPACE  

SciTech Connect

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 1{sub 0}-0{sub 0} line of the deuterated ammonium ion, NH{sub 3}D{sup +}. 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 NH{sub 3}D{sup +} as the electric field over the N nucleus is practically zero. Moreover, the feature is right at the predicted frequency for the 1{sub 0}-0{sub 0} transition of the ammonium ion, 262817 {+-} 6 MHz (3{sigma}), using rotational constants derived from new infrared data obtained in our laboratory in Madrid. The estimated column density is (1.1 {+-} 0.2) Multiplication-Sign 10{sup 12} cm{sup -2}. Assuming a deuterium enhancement similar to that of NH{sub 2}D, we derive N(NH{sub 4}{sup +}) {approx_equal} 2.6 Multiplication-Sign 10{sup 13} cm{sup -2}, i.e., an abundance for ammonium of a few 10{sup -11}.

Cernicharo, J.; Tercero, B. [Deparment of Astrophysics, CAB, INTA-CSIC, Crta Torrejon-Ajalvir Km 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Fuente, A. [Observatorio Astronomico Nacional, Apdo. 112, E-28803 Alcala de Henares (Spain); Domenech, J. L.; Cueto, M.; Carrasco, E.; Herrero, V. J.; Tanarro, I. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, E-28006 Madrid (Spain); Marcelino, N. [NRAO, 520 Edgemont Road, Charlottesville, VA 22902 (United States); Roueff, E. [Luth, Observatoire de Paris, CNRS UMR8102, Place J. Janssen F-92190 Meudon (France); Gerin, M. [LERMA, Observatoire de Paris, CNRS UMR8112 and Ecole Normale Superieure, 61 Avenue de lObservatoire, F-75014 Paris (France); Pearson, J., E-mail: jcernicharo@cab.inta-csic.es [Jet Propulsion Laboratory, 4800 Oak Grove Drive, MC 168-314, Pasadena, CA 91109 (United States)

2013-07-01

305

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

306

Repeated High Intensity Bouts with Long Recovery: Are Bicarbonate or Carbohydrate Supplements an Option?  

PubMed Central

The effects of varying recovery modes and the influence of preexercise sodium bicarbonate and carbohydrate ingestion on repeated high intensity performance, acid-base response, and recovery were analyzed in 12 well-trained males. They completed three repeated high intensity running bouts to exhaustion with intervening recovery periods of 25?min under the following conditions: sodium bicarbonate, active recovery (BIC); carbohydrate ingestion, active recovery (CHO); placebo ingestion, active recovery (ACTIVE); placebo ingestion, passive recovery (PASSIVE). Blood lactate (BLa), blood gases, heart rate, and time to exhaustion were collected. The three high intensity bouts had a duration of 138 ± 9, 124 ± 6, and 121 ± 6?s demonstrating a decrease from bout 1 to bout 3. Supplementation strategy had no effect on performance in the first bout, even with differences in pH and bicarbonate (HCO3?). Repeated sprint performance was not affected by supplementation strategy when compared to ACTIVE, while PASSIVE resulted in a more pronounced decrease in performance compared with all other interventions. BIC led to greater BLa, pH, and HCO3? values compared with all other interventions, while for PASSIVE the opposite was found. BLa recovery was lowest in PASSIVE; recovery in pH, and HCO3? was lower in PASSIVE and higher in BIC.

Stöggl, Thomas; Torres-Peralta, Rafael; Cetin, Ebru

2014-01-01

307

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

PubMed

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

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

2013-04-01

308

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

USGS Publications Warehouse

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

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

2013-01-01

309

Electrophoretic mobilities of erythrocytes in various buffers  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

310

Bedrock Nitrogen and Hydrothermal Ammonium in Yellowstone National Park, WY, USA  

NASA Astrophysics Data System (ADS)

High ammonium concentrations in some of the hot springs of Yellowstone National Park (up to 880 mg L-1 as N at Washburn Hot Springs) have been attributed to leaching of sedimentary rock by hydrothermal solutions. However, relatively little is known about the direct relationship between rock geochemistry in volcanic centers and nitrogen in thermal waters. For this study, a suite of core samples from US Geological Survey drill holes in Yellowstone National Park were characterized for nitrogen and carbon in different lithologies. These data were related to the aqueous geochemistry and ? 15N-NH4+ of thermal waters in different hot spring basins in the park to better understand the water-rock interactions. Core samples selected for study included tuff, water-reworked volcanic sediments, glacial sediment, lacustrine sedimentary rock, and marine sedimentary rock. Substantial amounts of nitrogen were present in all bedrock types, with the highest nitrogen concentrations measured in marine sedimentary rocks (430-830 mg N kg-1) from Y10, which is located at Mammoth Hot Springs. Although the underlying bedrock has elevated nitrogen concentrations, hydrothermal ammonium concentrations at Mammoth Hot Springs are relatively low (~1 mg L-1 as N). These solutions are buffered by carbonate (pH >8) and may have lost some N by volatilization as ammonia gas. Thermal waters in Norris Geyser Basin are acid to circumneutral with ammonium concentrations ranging from <0.03 to 80 mg L-1 as N. Nitrogen in tuffs (400-620 mg N kg-1) from drill holes Y9 and Y12 at Norris Geyser Basin may be present as a result of ammonium partitioning from solution to zeolites or other secondary minerals. Thermal waters sampled at Mammoth, Norris, and other geyser basins in the park varied widely in ammonium concentrations and isotopic compositions (? 15N), from <0.3 to 450 mg L-1 as N and -5 to +25‰ , respectively. The isotope data are interpreted to reflect multiple processes, including leaching of nitrogen from sedimentary sources, partitioning of ammonium from solution to secondary minerals, with fractionations resulting from boiling and steam distillation of ammonia gas.

Holloway, J. M.; Bohlke, J. K.; Nordstrom, D. K.

2003-12-01

311

THE EFFECTS OF 8 WEEKS OF LOW DOSE SUPPLEMENTATION OF CREATINE AND SODIUM BICARBONATE ON EXERCISE PERFORMANCE.  

E-print Network

?? Short-term (3-7 days), high doses of creatine (20g/d) and/or sodium bicarbonate (0.5g/kg body weight) supplementation increase exercise performance during short term high intensity activities;… (more)

Morris, Amanda Jessica

2013-01-01

312

Acclimation and toxicity of high ammonium concentrations to unicellular algae.  

PubMed

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

Collos, Yves; Harrison, Paul J

2014-03-15

313

Photosystem II and the unique role of bicarbonate: a historical perspective.  

PubMed

In photosynthesis, cyanobacteria, algae and plants fix carbon dioxide (CO(2)) into carbohydrates; this is necessary to support life on Earth. Over 50 years ago, Otto Heinrich Warburg discovered a unique stimulatory role of CO(2) in the Hill reaction (i.e., O(2) evolution accompanied by reduction of an artificial electron acceptor), which, obviously, does not include any carbon fixation pathway; Warburg used this discovery to support his idea that O(2) in photosynthesis originates in CO(2). During the 1960s, a large number of researchers attempted to decipher this unique phenomenon, with limited success. In the 1970s, Alan Stemler, in Govindjee's lab, perfected methods to get highly reproducible results, and observed, among other things, that the turnover of Photosystem II (PSII) was stimulated by bicarbonate ions (hydrogen carbonate): the effect would be on the donor or the acceptor, or both sides of PSII. In 1975, Thomas Wydrzynski, also in Govindjee's lab, discovered that there was a definite bicarbonate effect on the electron acceptor (the plastoquinone) side of PSII. The most recent 1.9Å crystal structure of PSII, unequivocally shows HCO(3)(-) bound to the non-heme iron that sits in-between the bound primary quinone electron acceptor, Q(A), and the secondary quinone electron acceptor Q(B). In this review, we focus on the historical development of our understanding of this unique bicarbonate effect on the electron acceptor side of PSII, and its mechanism as obtained by biochemical, biophysical and molecular biological approaches in many laboratories around the World. We suggest an atomic level model in which HCO(3)(-)/CO(3)(2-) plays a key role in the protonation of the reduced Q(B). In addition, we make comments on the role of bicarbonate on the donor side of PSII, as has been extensively studied in the labs of Alan Stemler (USA) and Vyacheslav Klimov (Russia). We end this review by discussing the uniqueness of bicarbonate's role in oxygenic photosynthesis and its role in the evolutionary development of O(2)-evolving PSII. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial. PMID:22521596

Shevela, Dmitriy; Eaton-Rye, Julian J; Shen, Jian-Ren; Govindjee

2012-08-01

314

Sodium bicarbonate in seminal plasma stimulates the motility of mammalian spermatozoa through direct activation of adenylate cyclase.  

PubMed

Recently, a low molecular weight factor, which specifically stimulates sperm adenylate cyclase, was found in porcine seminal plasma (Okamura, N., and Sugita, Y. (1983) J. Biol. Chem. 258, 13056-13062). The purified factor was analyzed by 1H NMR, 13C NMR, infrared spectroscopy, and elementary analysis and identified as sodium bicarbonate. The effects of sodium bicarbonate both on adenylate cyclase activity in porcine spermatozoa and on sperm motility have been studied. Sperm adenylate cyclase was found to be specifically activated by bicarbonate over the physiological concentration range. In contrast, the adenylate cyclase activity in other tissues was not affected. The same concentration range of bicarbonate which resulted in activation of adenylate cyclase also stimulated sperm motility. The motility and enzyme activity of spermatozoa in all species so far tested (human, bovine, rat, mouse, and dog) were found to be similarly sensitive to bicarbonate concentration. These results show that the bicarbonate-sensitive adenylate cyclase system regulates sperm motility and suggest that this system is common to all mammals. PMID:2991260

Okamura, N; Tajima, Y; Soejima, A; Masuda, H; Sugita, Y

1985-08-15

315

Competitive Parallel Disk Prefetching and Buffer Management  

E-print Network

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

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

2000-01-01

316

How Might New Neurons Buffer Against Stress?  

MedlinePLUS

How Might New Neurons Buffer Against Stress? Recent News Rapid Mood Lifter First Jump-starts Pleasure-seeking October 17, 2014 Groundbreaking ... Risks Rise Early in Psychosis October 8, 2014 New US Clinical Data on Mental Disorders October 8, ...

317

A MICROPROCESSOR ASCII CHARACTER BUFFERING SYSTEM  

EPA Science Inventory

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 laboratory automation co...

318

Soil Formation & Retention Stores and buffers  

E-print Network

Soil Formation & Retention· Stores and buffers soil nutrients · Stores water · Drives soil ecosystem #12;Flood control · Water filtration, retention and flow · Protection from tsunamis and hurricanes

Gottgens, Hans

319

Buffer assignment algorithms for data driven architectures  

E-print Network

BUFFER ASSIGNMENT ALGORITHMS FOR DATA DRIVEN ARCHITECTURES A Thesis by MITRA JIT CHATTERJEE Submitted to the OIIIce of Graduate Studies of Texas ASM University in partial ful611ment of the requirements for the degree of MASTER OF SCIENCE... August 1994 Major Subject: Computer Science BUFFER ASSIGNMENT ALGORITHMS FOR DATA DRIVEN ARCHITECTURES A Thesis by MITRAJIT CHATTERJEE Submitted to Texas ARM University in partial fulfillment of the requirements for the degree of MASTER...

Chatterjee, Mitrajit

2012-06-07

320

Buffer regulation of calcium puff sequences  

NASA Astrophysics Data System (ADS)

Puffs are localized Ca2 + signals that arise in oocytes in response to inositol 1,4,5-trisphosphate (IP3). They are the result of the liberation of Ca2 + from the endoplasmic reticulum through the coordinated opening of IP3 receptor/channels clustered at a functional release site. The presence of buffers that trap Ca2 + provides a mechanism that enriches the spatio-temporal dynamics of cytosolic calcium. The expression of different types of buffers along the cell's life provides a tool with which Ca2 + signals and their responses can be modulated. In this paper we extend the stochastic model of a cluster of IP3R-Ca2 + channels introduced previously to elucidate the effect of buffers on sequences of puffs at the same release site. We obtain analytically the probability laws of the interpuff time and of the number of channels that participate of the puffs. Furthermore, we show that under typical experimental conditions the effect of buffers can be accounted for in terms of a simple inhibiting function. Hence, by exploring different inhibiting functions we are able to study the effect of a variety of buffers on the puff size and interpuff time distributions. We find the somewhat counter-intuitive result that the addition of a fast Ca2 + buffer can increase the average number of channels that participate of a puff.

Fraiman, Daniel; Ponce Dawson, Silvina

2014-02-01

321

Distinct and additive effects of sodium bicarbonate and continuous mild heat stress on fiber type shift via calcineurin/NFAT pathway in human skeletal myoblasts.  

PubMed

Ingestion of sodium bicarbonate (NaHCO3) is known to enhance athletic performance, probably via increased extracellular buffering capacity. At present, little is known about the direct effects of NaHCO3 on myogenesis, especially in vitro. Here, we examined the effects of NaHCO3 and the combined effects of NaHCO3 and continuous mild heat stress (CMHS) at 39°C on the differentiation of human skeletal muscle myoblasts (HSMMs). Levels of myosin heavy chain (MyHC) type I mRNA increased with increasing NaHCO3 concentrations; in contrast, those of MyHC IIx decreased. The NaHCO3-induced fast-to-slow shift was additively enhanced by CMHS. Likewise, intracellular calcium levels and expression of three factors, nuclear factor of activated T cells c2 (NFATc2), NFATc4, and peroxisome-proliferator-activated receptor-? coactivator-1?, were upregulated with increasing NaHCO3 concentrations; moreover, these effects of NaHCO3 were additively enhanced by CMHS. Overexpression experiments and small interfering RNA-mediated knockdown experiments confirmed that NFATc2 and NFATc4 were involved in MyHC I regulation. The present study provided evidence that NaHCO3 and CMHS distinctly and additively induced a fast-to-slow fiber type shift through changes in intracellular calcium levels and the modulation of calcium signaling. PMID:23703530

Yamaguchi, Tetsuo; Omori, Maiko; Tanaka, Nobuho; Fukui, Naoshi

2013-08-01

322

Dimethyl-ammonium dichloridotriphenyl-stannate(IV)  

PubMed Central

The title salt, [(CH3)2NH2][Sn(C6H5)3Cl2], was obtained as a by-product of the reaction between bis­(dimethyl­ammonium) oxalate and triphenyl­tin chloride. In the stannate anion, the trigonal–bipyramidal coordination environment of the SnIV atom is defined by the phenyl groups in equatorial and the Cl atoms in axial positions. The cations are connected to adjacent anions through N—H?Cl and C—H?Cl hydrogen-bonding inter­actions, leading to a chain motif parallel to [100]. PMID:22807710

Sow, Yaya; Diop, Libasse; Kociok-Kohn, Gabriele; Molloy, Kieran C.

2012-01-01

323

Antibacterial activity of gemini quaternary ammonium salts.  

PubMed

A series of gemini quaternary ammonium salts (chlorides and bromides), with various hydrocarbon chain and spacer lengths, were tested. These compounds exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria and were not mutagenic. The strongest antibacterial effect was observed for TMPG-10 Cl (against Pseudomonas aeruginosa ATCC 27853) and TMPG-12 Br (against Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 11229 and clinical ESBL(+) isolate 434) surfactants. These compounds inhibited the adhesion of Staphylococcus epidermidis ATCC 35984 to a polystyrene surface and eradicated biofilm formed by P. aeruginosa PAO1. The activity of studied compounds was dependent on hydrocarbon chain length. PMID:24236547

Ob??k, Ewa; Piecuch, Agata; Guz-Regner, Katarzyna; Dworniczek, Ewa

2014-01-01

324

Ammonium Chloride and Ammonium Sulfate for Prevention of Parturient Paresis in Dairy Cows1  

Microsoft Academic Search

Forty-eight Holstein cows with two or more previous lactations and no history of parturient paresis were randomly assigned to one of four prepartum diets in a 2 x 2 factorial design to determine the effect of dietary supplementation with ammonium salts and Ca intake on serum Ca concentrations at calving. Four diets provided either 53 g total dietary Ca\\/d or

G. R. Oetzel; J. D. Olson; C. R. Curtis; M. J. Fettman

1988-01-01

325

Effect of bicarbonate on efficacy of oral rehydration therapy: studies in an experimental model of secretory diarrhoea.  

PubMed Central

In situ perfusion of rat intestine was used to evaluate the effect of bicarbonate on the efficacy of a low sodium (35 mmol/l) glucose-electrolyte oral rehydration solution in normal and cholera toxin-treated rat small intestine. In normal intestine, absorption of water was greater (108 (8.1) microliters/min/g; p less than 0.01) and sodium secretion less (-4.3 (0.3) mumol/min/g; p less than 0.01) from the oral rehydration solution containing bicarbonate than from the solution in which bicarbonate was replaced by chloride ions (59.5 (7.2) microliters/min/g and -7.8 (0.8) mumol/min/g, respectively). Glucose absorption in normal intestine was similar with both solutions. In the secreting intestine, both oral rehydration solutions reversed net water secretion to absorption, but inclusion of bicarbonate resulted in significantly less net absorption of both water (2.18 (6.9) microliters/min/g; p less than 0.05) and glucose (18.7 (2.1) mumol/min/g; p less than 0.001) compared with bicarbonate free oral rehydration solution (19.4 (3.9) microliters/min/g and 35.8 (3.7) mumol/min/g, respectively). Net sodium secretion occurred in normal and secreting intestine but was significantly less with the bicarbonate containing oral rehydration solution. These findings suggest that the demonstrable advantage of bicarbonate in promoting water absorption from this oral rehydration solution in normal rat intestine does not apply to cholera toxin treated secreting intestine. PMID:3410331

Elliott, E J; Watson, A J; Walker-Smith, J A; Farthing, M J

1988-01-01

326

Quantification of Kinetic Rate Law Parameters of Uranium Release from Sodium Autunite as a Function of Aqueous Bicarbonate Concentrations  

SciTech Connect

ABSTRACT: Hydrogen carbonate is one of the most significant components within the uranium geochemical cycle. In aqueous solutions, hydrogen carbonate forms strong complexes with uranium. As such, aqueous bicarbonate may significantly increase the rate of uranium release from uranium minerals. Quantifying the relationship of aqueous hydrogen carbonate solutions to the rate of uranium release during dissolution is critical to understanding the long-term fate of uranium within the environment. Single-pass flow-through (SPTF) experiments were conducted to estimate the rate of uranium release from Na meta-autunite as a function of bicarbonate solutions (0.0005-0.003 M) under the pH range of 6-11 and temperatures of 5-60oC. Consistent with the results of previous investigation, the rate of uranium release from sodium autunite exhibited minimal dependency on temperature; but were strongly dependent on pH and increasing concentrations of bicarbonate solutions. Most notably at pH 7, the rate of uranium release exhibited 370 fold increases relative to the rate of uranium release in the absence of bicarbonate. However, the effect of increasing concentrations of bicarbonate solutions on the release of uranium was significantly less under higher pH conditions. It is postulated that at high pH values, surface sites are saturated with carbonate, thus the addition of more bicarbonate would have less effect on uranium release. Results indicate the activation energies were unaffected by temperature and bicarbonate concentration variations, but were strongly dependent on pH conditions. As pH increased from 6 to 11, activation energy values were observed to decrease from 29.94 kJ mol-1 to 13.07 kJ mol-1. The calculated activation energies suggest a surface controlled dissolution mechanism.

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

2013-09-05

327

Infusion of sodium bicarbonate in experimentally induced metabolic acidosis does not provoke cerebrospinal fluid (CSF) acidosis in calves  

PubMed Central

In a crossover study, 5 calves were made acidotic by intermittent intravenous infusion of isotonic hydrochloric acid (HCl) over approximately 24 h. This was followed by rapid (4 h) or slow (24 h) correction of blood pH with isotonic sodium bicarbonate (NaHCO3) to determine if rapid correction of acidemia produced paradoxical cerebrospinal fluid (CSF) acidosis. Infusion of HCl produced a marked metabolic acidosis with respiratory compensation. Venous blood pH (mean ± Sx) was 7.362 ± 0.021 and 7.116 ± 0.032, partial pressure of carbon dioxide (Pco2, torr) 48.8 ± 1.3 and 34.8 ± 1.4, and bicarbonate (mmol/L), 27.2 ± 1.27 and 11 ± 0.96; CSF pH was 7.344 ± 0.031 and 7.240 ± 0.039, Pco2 42.8 ± 2.9 and 34.5 ± 1.4, and bicarbonate 23.5 ± 0.91 and 14.2 ± 1.09 for the period before the infusion of hydrochloric acid and immediately before the start of sodium bicarbonate correction, respectively. In calves treated with rapid infusion of sodium bicarbonate, correction of venous acidemia was significantly more rapid and increases in Pco2 and bicarbonate in CSF were also more rapid. However, there was no significant difference in CSF pH. After 4 h of correction, CSF pH was 7.238 ± 0.040 and 7.256 ± 0.050, Pco2 44.4 ± 2.2 and 34.2 ± 2.1, and bicarbonate 17.8 ± 1.02 and 14.6 ± 1.4 for rapid and slow correction, respectively. Under the conditions of this experiment, rapid correction of acidemia did not provoke paradoxical CSF acidosis. PMID:22754090

Abeysekara, Saman; Zello, Gordon A.; Lohmann, Katharina L.; Alcorn, Jane; Hamilton, Don L.; Naylor, Jonathan M.

2012-01-01

328

Intraoral evaluation of mineralization of cosmetic defects by a toothpaste containing calcium, fluoride, and sodium bicarbonate.  

PubMed

New dual-phase fluoride toothpastes that contain soluble calcium, phosphate, and baking soda have recently been introduced into the market. These toothpastes are designed to fill in small surface defects in tooth enamel and thereby enhance tooth esthetics such as gloss. This two-part study was designed to assess these superficial mineralizing effects from using one of these products compared with an experimental calcium-containing, bicarbonate-free formulation and a conventional fluoride toothpaste using an intraoral model. Enamel specimens with 4 types of defects were mounted into an intraoral appliance and placed in the mouths of volunteers for 1 month. The four types of defects were whitening toothpaste abrasion, coarse abrasion, natural dimpling, and acid etching. Before and after intraoral exposure, scanning electron microscope photographs of the specimens were made. The surface microhardness of the acid-etched specimens also was determined. The volunteers brushed their specimens twice daily with one of three randomly assigned toothpastes. The toothpastes were a two-phase, calcium-containing, bicarbonate-based toothpaste; an experimental, two-phase, calcium-containing, bicarbonate-free toothpaste; and a conventional toothpaste. Only the calcium-containing toothpastes showed unequivocal signs of mineral deposition into surface defects, leading to smoothing of the enamel. All three products significantly increased the hardness of the etched enamel, presumably because of fluoride. However, only the two calcium-containing toothpastes gave significantly greater hardness increases than the conventional toothpaste; the specimens treated with a conventional toothpaste were indistinguishable from those treated with saliva. PMID:15645904

Litkowski, Leonard J; Quinlan, Kathleen B; Ross, David R; Ghassemi, Annahita; Winston, Anthony; Charig, Andrew; Flickinger, Mark; Vorwerk, Linda

2004-09-01

329

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

PubMed

Mackinawite, Fe(II)S, samples loaded with uranium (10(-5), 10(-4), and 10(-3) mol U/g FeS) at pH 5, 7, and 9, were characterized using X-ray absorption spectroscopy and X-ray diffraction to determine the effects of pH, bicarbonate, and oxidation on uptake. Under anoxic conditions, a 5 g/L suspension of mackinawite lowered 5 × 10(-5) M uranium(VI) to below 30 ppb (1.26 × 10(-7) M) U. Between 82 and 88% of the uranium removed from solution by mackinawite was U(IV) and was nearly completely reduced to U(IV) when 0.012 M bicarbonate was added. Near-neighbor coordination consisting of uranium-oxygen and uranium-uranium distances indicates the formation of uraninite in the presence and absence of bicarbonate, suggesting reductive precipitation as the dominant removal mechanism. Following equilibration in air, mackinawite was oxidized to mainly goethite and sulfur and about 76% of U(IV) was reoxidized to U(VI) with coordination of uranium to axial and equatorial oxygen, similar to uranyl. Additionally, uranium-iron distances, typical of coprecipitation of uranium with iron oxides, and uranium-sulfur distances indicating bidentate coordination of U(VI) to sulfate were evident. The affinity of mackinawite and its oxidation products for U(VI) provides impetus for further study of mackinawite as a potential reactive medium for remediation of uranium-contaminated water. PMID:23742708

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

2013-07-01

330

Interaction of heavy metal ions with ammonium humates  

SciTech Connect

Sorption properties of ammonium humates with respect to Fe(III), Cu(II), Al(III), Ni(II), Pb(II), and Zn(II) are studied. The effect of the metal ion concentration on the ammonium humate consumption is examined and the corresponding dependences are analyzed using regression equations. The IR spectra of brown coal humic acids, ammonium humates, as well as Fe, Cu, Ni, Zn, Pb, and Al humates are presented.

Budaeva, A.D.; Zoltoev, E.V.; Tikhova, V.D.; Bodoev, N.V. [Russian Academy for Science, Buryatiya (Russian Federation)

2006-06-15

331

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

332

Ammonium bisulfate/water: a pseudobinary system.  

PubMed

We have studied the ammonium bisulfate/water system using thermal analysis (differential scanning calorimetry) and infrared spectroscopy of thin films. Our results for the melting points for ice and letovicite are in good agreement with other experimental work. However, we report here the first measurements of the ice/ammonium bisulfate/letovicite invariant point. We have used our observations and solubility data to construct a complete phase diagram for this system. Utilizing phase diagram theory and the Gibbs phase rule, we conclude that this system is not a true binary system but rather a pseudobinary system, which has a range of concentrations that cannot be represented by a simple binary phase diagram and thus must be viewed as part of the ternary system: H(2)SO(4)/(NH(4))(2)SO(4)/H(2)O. We also compared our results to the phase diagram predictions of the aerosol inorganics model and found the predicted melting points are in good agreement with experimental work over a limited concentration range, but the transitions predicted by the model at lower temperatures are not in agreement with experimental results. PMID:16737260

Beyer, Keith D; Bothe, Jameson

2006-06-01

333

Effect of Reduced Renal Mass on Ammonium Handling and Net Acid Formation by the Superficial and Juxtamedullary Nephron of the Rat  

PubMed Central

Papillary and surface micropuncture were used to study the handling of ammonium and the formation of net acid by surface nephrons, deep nephrons, and the terminal segment of collecting duct (CD) after renal mass was reduced by two-thirds. Net acid excretion by the remnant kidney (RK) was significantly reduced, averaging 794±81 neq/min (SE) compared with 1,220±105 neq/min after sham operation (P < 0.001), due to a decrease in ammonium excretion (494±54 vs. 871±79 nmol/min in controls, P < 0.001). Urinary pH and titratable acid excretion were not different in the two groups of animals. After RK formation, ammonium delivery to the end of the proximal tubule increased nearly threefold and averaged 66.2±5.6 compared with 18.4±2.9 pmol/min in controls, (P < 0.001). This greater delivery of ammonium was primarily due to renal tubule entry rather than to changes in the filtered load and was only partially related to the differences in flow rate. Ammonium processing by deep nephrons was profoundly affected by a reduction in renal mass. Although absolute delivery of ammonium was greater to the bend of Henle's loop (BHL), the difference could be accounted for on the basis of an increase in nephron size. Thus, fractional delivery (FDNH+4) to this site was not different for the two groups of animals, averaging 1,567±180% in controls and 1,400±181% in the group with the RK. Hydrogen secretion in the proximal segments of deep and surface nephrons did not increase in proportion to the decrease in renal mass and as a consequence bicarbonate delivery to the end of the proximal tubule of surface nephrons and to the BHL of deep nephrons was increased. When renal mass was reduced FDNH+4 to the base of the terminal CD doubled but did not change by the tip. In both groups FDNH+4 to the base of the CD was greater than to the end of the distal tubule. However, the increase was the same. On the other hand, the increase in the net acid index between the end of the distal tubule and the base of the CD was profoundly greater in rats with an RK. This difference was primarily due to bicarbonate reabsorption rather than enhanced ammonium reentry. Indeed, >400% of the fractional ammonium delivered to the end of the proximal tubule was lost from the tubule fluid. The data suggest that the decrease in acid excretion by the RK is due to two factors. First, hydrogen secretion in the proximal segments of both nephron populations fails to increase in the proportion to the reduction in renal mass. Second, a reduced reentrapment of ammonia, rather than its impaired production, causes ammonium excretion to decrease. PMID:6863538

Buerkert, John; Martin, Daniel; Trigg, David; Simon, Eric

1983-01-01

334

The ability of modified Krebs Ringer bicarbonate diluents to maintain stallion spermatozoa  

E-print Network

bicarbonate (KRB) extenders to maintain stallion spermatozoal motility and viability when spermatozoa were cultured at 37'C for . 5, 1. 5, 2. 5, and 4 h. Two KRB extenders contained either 3% bovine serum albumin (KRB-BSAm) or 10' fetal calf serum (KRB...&. 05) between tteatments through 1. 5 h of culture. However, after 2. 5 h of culture percent progressively motile spermatozoa (PMS) was highest (P&. 05) in KRB-FCS and lowest (P&. 05) in skim milk extender when compared with the PMS for all other...

Wright, Diane Lynne

2012-06-07

335

Ammonium removal from sanitary landfill leachate using natural Gördes clinoptilolite.  

PubMed

Removal of ammonium ion (NH(4)(+)) from leachate from Odayeri sanitary landfill, located in the European part of Istanbul, was examined using Gördes (Turkish) clinoptilolite. The effects of pH, flow rate, ammonium concentration and competitive cations on the removal efficiency were investigated in both batch and column studies. Thomas model were used to analyze the breakthrough data. Nonlinear least square method was applied for fitting the column data. The competitive effect was observed more effective in lower ammonium concentration and higher cation concentrations. Conditioning and regeneration using NaCl improved removal efficiency of ammonium from leachate. PMID:17868987

Karadag, Dogan; Tok, Sema; Akgul, Eda; Turan, Mustafa; Ozturk, Mustafa; Demir, Ahmet

2008-05-01

336

Effects of ammonium concentration and charge exchange on ammonium recovery from high strength wastewater using a microbial fuel cell.  

PubMed

Ammonium recovery using a two chamber microbial fuel cell (MFC) was investigated at high ammonium concentration. Increasing the ammonium concentration (from 0.07 to 4 g ammonium-nitrogen/L) by addition of ammonium chloride did not affect the performance of the MFC. The obtained current densities by DC-voltammetry were higher than 6A/m(2) for both operated MFCs. Also continuous operation at lower external resistance (250 ?) showed an increased current density (0.9A/m(2)). Effective ammonium recovery can be achieved by migrational ion flux through the cation exchange membrane to the cathode chamber, driven by the electron production from degradation of organic substrate. The charge transport was proportional to the concentration of ions. Nonetheless, a concentration gradient will influence the charge transport. Furthermore, a charge exchange process can influence the charge transport and therefore the recovery of specific ions. PMID:21277769

Kuntke, P; Geleji, M; Bruning, H; Zeeman, G; Hamelers, H V M; Buisman, C J N

2011-03-01

337

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

338

The Influence of Buffer Species and Strength on Diltiazem HC1 Release from Beads Coated with the Aqueous Cationic Polymer Dispersions, Eudragit RS, RL 30D  

Microsoft Academic Search

Purpose. Eudragit RL and RS 30D are pseudolatexes frequently used in the coating of solid dosage forms. They are based on cationic copolymers stabilized with quaternary ammonium groups (poly(ethylacrylate-methylmethacrylate-trimethylammonioethyl methacrylate chloride). A pH-independent drug release is expected because of the quaternary nature of the cationic groups. The objective was to explain a distinct “pH-dependent” drug release in various buffer media

Roland Bodmeier; Xiaodi Guo; Rafael E. Sarabia; Paul F. Skultety

1996-01-01

339

Distributed Utility-Optimal Scheduling with Finite Buffers  

E-print Network

Distributed Utility-Optimal Scheduling with Finite Buffers Dongyue Xue, Robert Murawski, Eylem algorithm for networks with single-hop transmissions that can guarantee finite buffer sizes and meet minimum with a tradeoff in the buffer sizes. The finite buffer property is not only important from an implementation

Paris-Sud XI, Université de

340

Buffered Resource Constraint: Algorithms and Christian Bessiere1  

E-print Network

Buffered Resource Constraint: Algorithms and Complexity Christian Bessiere1 , Emmanuel Hebrard2.walsh@nicta.com.au Abstract. The notion of buffered resource is useful in many problems. A buffer contains a finite set of items required by some activities, and changing the content of the buffer is costly. For instance

Paris-Sud XI, Université de

341

Fast Algorithms For Slew Constrained Minimum Cost Buffering  

E-print Network

Fast Algorithms For Slew Constrained Minimum Cost Buffering Shiyan Hu, Charles J. Alpert , Jiang demand for buffer- ing resources. This problem requires ultra-fast buffering techniques to handle large volume of nets, while also min- imizing buffering cost. This problem is intensively studied in this paper

Hu, Jiang

342

Formal But Lively Buffers in TLA+ Peter B. Ladkin  

E-print Network

Formal But Lively Buffers in TLA+ Peter B. Ladkin omitted. We specify in TLA a buffer implemented as an array, a dou- ble buffer implemented as two arrays in series, and an abstract buffer which uses a sequence. We prove, formally and rigorously

Ladkin, Peter B.

343

Formal But Lively Buffers in TLA + Peter B. Ladkin  

E-print Network

Formal But Lively Buffers in TLA + Peter B. Ladkin Universit¨at Bielefeld, Technische Fakult­ stood, our example needs only the trivial invariant, which is simply omitted. We specify in TLA a buffer implemented as an array, a dou­ ble buffer implemented as two arrays in series, and an abstract buffer which

Ladkin, Peter B.

344

Optimal buffer control during congestion in an ATM network node *  

E-print Network

Optimal buffer control during congestion in an ATM network node * Leandros Tassiulas Yaochung Hung the number of cells to be st,ored in the buffer exceeds the available buffer space, ccriaiii cells havea.y be dropped after they are already in the buffer. Ilel~endingon the control that we have

Panwar, Shivendra S.

345

Scheduling in Switches with Small Internal Buffers: Extended Version  

E-print Network

Scheduling in Switches with Small Internal Buffers: Extended Version Nikos Chrysos and Manolis://archvlsi.ics.forth.gr/bpbenes/ Abstract-- Unbuffered crossbars or switching fabrics contain no internal buffers, and function using only, during each time slot. Buffered crossbars, on the other hand, contain sufficient internal buffering (N2

Katevenis, Manolis G.H.

346

Small-Buffer Networks Mark Shifrin, Isaac Keslassy  

E-print Network

Small-Buffer Networks Mark Shifrin, Isaac Keslassy Department of Electrical Engineering, Technion buffers, which significantly increase their power consumption and design time. Re- cent models of large-buffer networks have suggested that these large buffers could be replaced with much smaller ones. Unfortunately

Keslassy, Isaac

347

Buffer sizing in 802.11 Wireless Mesh Networks  

E-print Network

Buffer sizing in 802.11 Wireless Mesh Networks Electrical Engineering Day Basem Shihada #12 `Bufferbloat' Large FTP 2 #12;Impact of large buffers · TCP cwnd grows to fill available (large) buffers ­ Impacts TCP stability ­ Increases queueing delays for other flows sharing the buffer 3 #12;Problem

Shihada, Basem

348

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

349

Buffer overflow bounds for multiplexed regulated traffic streams F. Guillemina  

E-print Network

1 Buffer overflow bounds for multiplexed regulated traffic streams F. Guillemina , N. Likhanovb , R in a common buffer. We derive bounds on the tail of the probability distribution function of the buffer of buffer overflow in the single input case. We then consider the case when the number of sources is large

Guillemin, Fabrice

350

LC\\/MS for the degradation profiling of cough–cold products under forced conditions  

Microsoft Academic Search

Heat, acid, base, UV radiation and oxidation stress methods were applied to study the stability of cough–cold products containing acetaminophen, phenylephrine or phenylpropanolamine hydrochloride and chlorpheniramine maleate. Liquid chromatography coupled with mass spectrometry was used to analyze the degraded samples and obtain molecular weights information. Different volatile buffers (ammonium bicarbonate and ammonium acetate) were assayed in LC\\/MS methods and retention

A. Mar??n; C. Barbas

2004-01-01

351

Long-term performance of bicarbonate-form anion exchange: Removal of dissolved organic matter and bromide from the St. Johns River, FL, USA  

Microsoft Academic Search

The goal of this research was to evaluate the long-term performance of magnetic ion exchange (MIEX) treatment using bicarbonate as the mobile counter ion (i.e., MIEX-HCO3) and sodium bicarbonate for regeneration. This work is important because there are many unknowns concerning the affinity and regeneration efficiency of bicarbonate-form anion exchange, whereas chloride-form anion exchange (i.e., MIEX-Cl resin) is well-studied. Raw

Krystal M. Walker; Treavor H. Boyer

2011-01-01

352

Bicarbonate transport along the loop of Henle. II. Effects of acid-base, dietary, and neurohumoral determinants.  

PubMed Central

The loop of Henle contributes to renal acidification by reabsorbing about 15% of filtered bicarbonate. To study the effects on loop of Henle bicarbonate transport (JHCO3) of acid-base disturbances and of several factors known to modulate sodium transport, these in vivo microperfusion studies were carried out in rats during: (a) acute and chronic metabolic acidosis, (b) acute and chronic (hypokalemic) metabolic alkalosis, (c) a control sodium diet, (d) a high-sodium diet, (e) angiotensin II (AII) intravenous infusion, (f) simultaneously intravenous infusion of both AII and the AT1 receptor antagonist DuP 753, (g) acute ipsilateral mechanicochemical renal denervation. Acute and chronic metabolic acidosis increased JHCO3; acute metabolic alkalosis significantly reduced JHCO3, whereas chronic hypokalemic alkalosis did not alter JHCO3. Bicarbonate transport increased in animals on a high-sodium intake and following AII administration, and the latter was inhibited by the AII (AT1) receptor antagonist DuP 753; acute renal denervation lowered bicarbonate transport. These data indicate that bicarbonate reabsorption along the loop of Henle in vivo is closely linked to systemic acid-base status and to several factors known to modulate sodium transport. Images PMID:8040339

Capasso, G; Unwin, R; Ciani, F; De Santo, N G; De Tommaso, G; Russo, F; Giebisch, G

1994-01-01

353

Investigating the Significance of Bicarbonate with the Corrosion of High-Strength Steel in CO2-Saturated Solutions  

NASA Astrophysics Data System (ADS)

This paper presents an electrochemical study on the corrosion behavior of API-X100 steel, heat-treated to have microstructures similar to those of the heat-affected zones (HAZs) of pipeline welding, in bicarbonate-CO2 saturated solutions. The corrosion reactions, onto the surface and through the passive films, are simulated by cyclic voltammetry. The interrelation between bicarbonate concentration and CO2 hydration is analyzed during the filming process at the open-circuit potentials. In dilute bicarbonate solutions, H2CO3 drives more dominantly the cathodic reduction and the passive films form slowly. In the concentrated solutions, bicarbonate catalyzes both the anodic and cathodic reactions, only initially, after which it drives a fast-forming thick passivation that inhibits the underlying dissolution and impedes the cathodic reduction. The significance of the substrate is as critical as that of passivation in controlling the course of the corrosion reactions in the dilute solutions. For fast-cooled (heat treatment) HAZs, its metallurgical significance becomes more comparable to that of slower-cooled HAZs as the bicarbonate concentration is higher.

Eliyan, Faysal Fayez; Alfantazi, Akram

2014-08-01

354

[Preparation and testing of buffers for fibrinogen].  

PubMed

Chloride-citrate-glucose solution was used in fibrinogen preparation for intravenous administration. Concentrated hydrochloric acid previously used for preparation of buffers for fibrinogen has been replaced by the diluted one enabling easier and more precise buffer pH regulation and faster fibrinogen dissolution. Procedure for spectrophotometric determination of the total citrate ion buffer system, sodium-citrate and citric acid was developed. Obtained results were within the prescribed limits but the ones obtained by officinal titration in non-aqueous medium were significantly decreased. Glucose was determined before sterilization by polymetric, and after sterilization by iodometric procedure. Chloride content was determined by coulometric titration and sodium content by flame photometry. Used analytic methods are simple and obtained results accurate and reproducible. PMID:8553608

Poprzen, V; Popovi?, R; Antunovi?, M

1994-01-01

355

14C Fixation by Leaves and Leaf Cell Protoplasts of the Submerged Aquatic Angiosperm Potamogeton lucens: Carbon Dioxide or Bicarbonate? 1  

PubMed Central

Protoplasts were isolated from leaves of the aquatic angiosperm Potamogeton lucens L. The leaves utilize bicarbonate as a carbon source for photosynthesis, and show polarity; that is, acidification of the periplasmic space of the lower, and alkalinization of the space near the upper leaf side. At present there are two models under consideration for this photosynthetic bicarbonate utilization process: conversion of bicarbonate into free carbon dioxide as a result of acidification and, second, a bicarbonate-proton symport across the plasma membrane. Carbon fixation of protoplasts was studied at different pH values and compared with that in leaf strips. Using the isotopic disequilibrium technique, it was established that carbon dioxide and not bicarbonate was the form in which DIC actually crossed the plasma membrane. It is concluded that there is probably no true bicarbonate transport system at the plasma membrane of these cells and that bicarbonate utilization in this species apparently rests on the conversion of bicarbonate into carbon dioxide. Experiments with acetazolamide, an inhibitor of periplasmic carbonic anhydrase, and direct measurements of carbonic anhydrase activity in intact leaves indicate that in this species the role of this enzyme for periplasmic conversion of bicarbonate into carbon dioxide is insignificant. PMID:16666848

Staal, Marten; Elzenga, J. Theo M.; Prins, Hidde B. A.

1989-01-01

356

Riparian forests buffer panel final report  

SciTech Connect

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

NONE

1996-10-01

357

Patterns in the Parathyroid Response to Sodium Bicarbonate Infusion Test in Healthy Volunteers  

PubMed Central

Background. The sodium bicarbonate infusion test evaluates the function of the parathyroid glands. The present study aims to evaluate the range of parathyroid response in healthy individuals and the potential influence of various factors. Methods. Fifty healthy volunteers were subjected to the test. Levels of vitamin D, calcium, albumin, and PTH were measured before infusion. PTH was measured at 3, 5, 10, 30, and 60 minutes after infusion. Results. A curve describing the response of parathyroids to the test was drawn. Twenty percent of the subjects had blunted PTH response. No significant difference was observed between normal and blunted responders concerning age, BMI, baseline PTH, or calcium levels. Nonetheless, there was a significant difference in vitamin D levels (P = 0.024). Interpretation. The test is easy to perform and may be used for everyday screening. It has to be clarified whether our observations are, at least partly, produced due to the presence of individuals with a constitutively blunted response or if low levels of vitamin D decrease the ability of the parathyroids to respond. Whichever the case, PTH response of normal individuals to sodium bicarbonate infusion test is more varied than previously thought and vitamin D levels influence it. PMID:24804234

Papavramidis, Theodossis S.; Anastasiou, Olympia E.; Pliakos, Ioannis; Triantafyllopoulou, Konstantina; Kokaraki, Georgia; Papavramidis, Spiros

2014-01-01

358

Integrated control of Penicillium digitatum by the predacious yeast Saccharomycopsis crataegensis and sodium bicarbonate on oranges.  

PubMed

Our investigation of integrated biological control (IBC) started with an assay testing activity of the predacious yeast Saccharomycopsis crataegensis UFMG-DC19.2 against Penicillium digitatum LCP 4354, a very aggressive fungus that causes postharvest decay in oranges. Under unfavourable environmental conditions, the yeast showed a high potential for control (39.9% disease severity reduction) of this fungus. This result was decisive for the next step, in which S. crataegensis was tested in association with sodium bicarbonate salt, a generally regarded as safe (GRAS) substance. The yeast was able to survive at different concentrations of the salt (1%, 2% and 5%), and continued to grow for a week at the wound site, remaining viable at high population for 14 days on the fruit surface. The yeast alone reduced the severity of decay by 41.7% and sodium bicarbonate alone reduced severity of decay by 19.8%, whereas the application of both led to a delay in the development of symptoms from 2 to 10 days. Ingredients of the formulations were not aggressive to fruits since no lesions were produced in control experiments. PMID:24031511

Pimenta, R S; Silva, J F M; Coelho, C M; Morais, P B; Rosa, C A; Corrêa, A

2010-04-01

359

Integrated control of Penicillium digitatum by the predacious yeast Saccharomycopsis crataegensis and sodium bicarbonate on oranges  

PubMed Central

Our investigation of integrated biological control (IBC) started with an assay testing activity of the predacious yeast Saccharomycopsis crataegensis UFMG-DC19.2 against Penicillium digitatum LCP 4354, a very aggressive fungus that causes postharvest decay in oranges. Under unfavourable environmental conditions, the yeast showed a high potential for control (39.9% disease severity reduction) of this fungus. This result was decisive for the next step, in which S. crataegensis was tested in association with sodium bicarbonate salt, a generally regarded as safe (GRAS) substance. The yeast was able to survive at different concentrations of the salt (1%, 2% and 5%), and continued to grow for a week at the wound site, remaining viable at high population for 14 days on the fruit surface. The yeast alone reduced the severity of decay by 41.7% and sodium bicarbonate alone reduced severity of decay by 19.8%, whereas the application of both led to a delay in the development of symptoms from 2 to 10 days. Ingredients of the formulations were not aggressive to fruits since no lesions were produced in control experiments. PMID:24031511

Pimenta, R. S.; Silva, J. F. M.; Coelho, C. M.; Morais, P. B.; Rosa, C. A.; Correa Jr, A.

2010-01-01

360

Evaluation of powder mixtures and hydrophilic gastroretentive drug delivery systems containing zinc acetate and sodium bicarbonate.  

PubMed

The aim of this study was to develop and study floating controlled drug delivery systems consisting of a model drug (zinc acetate dihydrate), different forms of a matrix-forming polymer (Metolose 90 SH) and sodium bicarbonate as an effervescent component. The proportions of Metolose and bicarbonate were varied, and the effects of the different ratios on the properties of the resulting powders and tablets were determined. The water uptakes of different powder mixtures were initially evaluated. These tests indicated the interaction of the active and effervescent agent, this phenomenon leading to an unpredicted increase in the amount of liquid taken up. This interaction was evaluated as concerns the degradation of the hydrophilic matrix system. The disintegration of tablets with different compositions revealed that this interaction increases the time required for the disintegration of these systems. The study demonstrated that the interaction of the components induced significant changes in the parameters of this new sensitive delivery system. In the last steps, the buoyancy and dissolution properties of tablets that appeared appropriate for the formulation of a controlled drug delivery system were investigated. PMID:21109379

Baki, Gabriella; Bajdik, János; Pintye-Hódi, Klára

2011-03-25

361

The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of some ammonium salts  

Microsoft Academic Search

Vapour pressures of water over saturated solutions of ammonium bromide, ammonium dihydrogen phosphate, ammonium thiosulfate, ammonium persulfate, ammonium acetate, ammonium oxalate and ammonium tartrate were determined as a function of temperature. These vapour pressures were used to evaluate the water activities, osmotic coefficients and molar enthalpies of vaporization. Molar enthalpies of solution of ammonium bromide ?solHm(NH4Br, T=293.97K, m=0.1030mol·kg?1)=(17.4±0.5)kJ·mol?1; ammonium hydrogen

Alexander Apelblat; Eli Korin

2003-01-01

362

boxcar, width, [buffer, /decimate] Boxcar smoothing clip, datamin, datamax, [buffer, /blank] Truncate spectrum to a min and max data value  

E-print Network

Other boxcar, width, [buffer, /decimate] Boxcar smoothing clip, datamin, datamax, [buffer, /blank] Truncate spectrum to a min and max data value decimate, [nchan, startat, buffer, ok] Decimate the spectrum by paring channels gconvol, kernel, [scale_factor, buffer, ok, /normalize, /center, Convolve the spectrum

Groppi, Christopher

363

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

2013-12-14

364

Solubilities in the ammonium thiosulfate-urea-ammonium nitrate-water system at 0°C  

Microsoft Academic Search

Solubilities in the system CO(NH2)2-NH4NO3-(NH4)2S2O3-H2O were obtained at 0°C and pH values between 6.12 and 7.33. The new composition of matter, (NH4)6(S2O3)2(NO3)2·CO(NH2)2, was identified and characterized chemically and microscopically. Stable high-analyses solution fertilizers can be produced at 0°C utilizing waste ammonium thiosulfate solutions with standard ammonium nitrate and urea fertilizer materials. A 31-0-0-5.6S grade (%N-%P2O5-%K2O-Other) fertilizer solution can be formed

A. W. Frazier; Y. K. Kim; C. L. Griffin

1990-01-01

365

AMMONIUM SULFATE AND BISULFATE FORMATION IN AIR PREHEATERS  

EPA Science Inventory

The overall goal of this study was to investigate the problems which result from deposition of ammonium sulfates in an air preheater. More specifically, the study had three major objectives. The first was to determine the conditions under which ammonium sulfates are expected to f...

366

Anaerobic ammonium oxidation by anammox bacteria in the Black Sea  

Microsoft Academic Search

The availability of fixed inorganic nitrogen (nitrate, nitrite and ammonium) limits primary productivity in many oceanic regions. The conversion of nitrate to N2 by heterotrophic bacteria (denitrification) is believed to be the only important sink for fixed inorganic nitrogen in the ocean. Here we provide evidence for bacteria that anaerobically oxidize ammonium with nitrite to N2 in the world's largest

Marcel M. M. Kuypers; A. Olav Sliekers; Gaute Lavik; Markus Schmid; Bo Barker Jørgensen; J. Gijs Kuenen; Jaap S. Sinninghe Damsté; Marc Strous; Mike S. M. Jetten

2003-01-01

367

Ammonium determination in soil extracts by the salicylate method  

Microsoft Academic Search

An ammonium determination, based on formation of a substituted indophenol with sodiumsalicylate as phenolic reagent, has been reexamined. An increase of 70% in absorbancy compared with existing salicylate methods in soil science, and an increase in reproducibility compared with pre?existing equivalent methods in other disciplines were obtained. The method can be applied satisfactorily for ammonium in 2M KCl soil extracts

A. J. Kempers; A. Zweers

1986-01-01

368

Ammonium assimilation in Proteus vulgaris, Bacillus pasteurii , and Sporosarcina ureae  

Microsoft Academic Search

No active uptake of ammonium was detected in Proteus vulgaris, Bacillus pasteurii, and Sporosarcina ureae, which indicates that these bacteria depend on the passive diffusion of ammonia across the cell membrane. In P. vulgaris the glutamine synthetase-glutamate synthase (GS-GOGAT) pathway and glutamate dehydrogenase (GDH) were present, and these enzymes exhibited high affinities for ammonium. In B. pasteurii and S. ureae,

Gerhard Miirsdorf; Heinrich Kaltwasser

1989-01-01

369

Response of anaerobic ammonium-oxidizing bacteria to hydroxylamine  

Microsoft Academic Search

Anaerobic ammonium oxidation is a recent addition to the microbial nitrogen cycle, and its metabolic pathway, including the production and conversion of its intermediate hydrazine, is not well understood. Therefore, the effect of hydroxylamine addition on the hydrazine metabolism of anaerobic ammonium-oxidizing (anammox) bacteria was studied both experimentally and by mathematical modeling. It was observed that hydroxylamine was disproportionated biologically

Maarten J. Van De Graaf; Boran Kartal; Cristian Picioreanu; Mike S. M. Jetten

2008-01-01

370

Microbial ammonium cycling in the Mississippi River plume during  

E-print Network

Microbial ammonium cycling in the Mississippi River plume during the drought spring of 2000 FRANK J of ammonium (NH4 + ) were studied along a salinity gradient (salinities 0.2­34.4) in the Mississippi River of Mexico are influenced by riverine freshwater inputs from the Mississippi River, which introduces

Jochem, Frank J.

371

Hybrid organic-inorganic crystals based on ammonium dihydrogen phosphate and ammonium salicylate  

NASA Astrophysics Data System (ADS)

ADP-NH 4Sal hybrid crystals are grown from aqueous solutions. The influence of the acidity of the mixed solution on the conditions of co-crystallization of the components is studied. The spectral and scintillation characteristics are determined. Co-crystallization of ammonium salicylate (NH 4Sal) and ammonium dihydrogen phosphate (ADP, NH 4H 2PO 4) is shown to be feasible, the structure of the doping addition being defined by the solution ??. In basic and weak acidic media the hybrid crystals ADP:NH 4Sal are formed in which salicylate anions are located in the interplanar space between the {110}-type planes in the lattice of ADP. The luminescence spectra contain an emission band maximum with ? max=360 nm. In acidic solutions there are ADP:HSal crystals in which salicylic acid molecules captured by the growth macrosteps are located in the interplanar space of the prismatic {100} and pyramidal {101} growth sectors. The luminescence band undergoes bathochromic shift to ?max=400 nm. The sensitivity of ADP:NH 4Sal scintillation crystals to fast neutrons depends on the concentration of ammonium salicylate in ADP matrix. The highest neutron sensitivity is characteristic of the co-doped ADP:NH 4Sal/Tl scintillation crystals.

Voronov, A. P.; Salo, V. I.; Puzikov, V. M.; Babenko, G. N.; Roshal, A. D.; Tkachenko, V. F.

2011-11-01

372

Variable Packet Size Buffered Crossbar (CICQ) Switches  

E-print Network

-Packet-Size BufXbars are even better · no SAR no speedup higher line rate · no output queues lower cost w. SAR: one-iteration iSLIP, 64-byte segments #12;A VPS Buffered Crossbar Chip Design · 32x32 ports, in Verilog ­ Core only, no pads & transceivers · Fully verified: Verilog versus C++ performance simulator

Katevenis, Manolis G.H.

373

A Discovery Chemistry Experiment on Buffers  

ERIC Educational Resources Information Center

The Holy Cross Chemistry Department has designed and implemented an experiment on buffers as part of our Discovery Chemistry curriculum. The pedagogical philosophy of Discovery Chemistry is to make the laboratory the focal point of learning for students in their first two years of undergraduate instruction. We first pose questions in prelaboratory…

Kulevich, Suzanne E.; Herrick, Richard S.; Mills, Kenneth V.

2014-01-01

374

Throughput Region of Finite-Buffered Networks  

E-print Network

the Internet, are packet switched networks. One of the main reasons behind the success of packet switched--Queuing theory, flow-controlled networks, scheduling, packet switching, buffered crossbars. Ã? 1 INTRODUCTION MOST of the current communication networks are packet switched networks. A prominent feature of packet networks

375

A Scheme of Predictor Based Stream Buffers  

E-print Network

Data Cache Misses In Superscalar � Redesign RF-Cache-DRAM memory hierarchy � Addition of L2 and L3 is a modified standard stream buffer. � A group of predictors with each predictor responsible for prediction � Implementation of PC-coupled predictors and compare with current performance. � Redesign the structure of stream

Rixner, Scott

376

Body Buffer Zone and Proxemics in Blocking.  

ERIC Educational Resources Information Center

This paper investigates the effect of personal body buffer zones on compositional arrangements staged by novice directors. Relationships between directors' concepts of personal space and their projection of its dimensions into staging are studied through the use of a variety of proximity measures--distance, area angles of approach, and physical…

Stockwell, John C.; Bahs, Clarence W.

377

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

378

Design and synthesis of novel isoelectric buffers  

E-print Network

made by attaching an isoelectric buffer of a welldefined pI value (such as iminodiacetic acid, IDA, aspartic acid, ASP or glutamic acid, GLU) to the PVA backbone and crosslinking the PVA strands, in situ. The pH in these membranes does not change...

Lalwani, Sanjiv Kumar Shankerdass

2006-04-12

379

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

380

COS Science Data Buffer Check/Self-Tests for CS Buffer RAM and DIB RAM  

NASA Astrophysics Data System (ADS)

The COS Science Buffer RAM is checked for bit flips during SAA passages. This is followed by a Control Section {CS} self-test consisting of writing/reading a specified bit pattern from each memory location in Buffer RAM and a similar test for DIB RAM. The DIB must be placed in BOOT mode for its self-test. The CS Buffer RAM self-test as well as the bit flip tests are all done with the CS in Operate.Supports Activity COS-03

Welty, Alan

2009-07-01

381

The effect of buffer species on hydration and mechanical properties of polymeric films prepared from aqueous colloidal cationic polymer dispersions  

SciTech Connect

Aqueous colloidal acrylic polymer dispersions have been used to formulate oral controlled drug delivery systems in the form of coated solid dosage forms. The hydration and mechanical properties of polymeric films prepared from Eudragit RS 30D (poly(ethylacrylate-methylmethacrylate-trimethylammonia ethyl methacrylate chloride) copolymers with ratios of 1:2:0.1) were studied in different buffer systems as a function of time. The buffer species which act as counterions to the quaternary ammonium groups in the polymer strongly affected the hydration and mechanical properties of the polymeric films. The mechanical properties of hydrated polymeric films were related to the water uptake of the films. The rate and extent of hydration determined the drug release pattern from coated dosage forms.

Guo, X.D.; Bodmeier, R. [Univ. of Texas, Austin, TX (United States); Sarabia, R.; Skultety, P. [Marion Merrell Dow Inc., Kansas City, MO (United States)

1993-12-31

382

Baroreflex buffering and susceptibility to vasoactive drugs  

NASA Technical Reports Server (NTRS)

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 and responses to vasoactive drugs in patients with idiopathic orthostatic intolerance, patients with essential hypertension, patients with monogenic hypertension and brachydactyly, patients with multiple system atrophy, and control subjects. We used phenylephrine sensitivity during ganglionic blockade as a measure of baroreflex buffering. Phenylephrine (25 microg) increased systolic blood pressure 6+/-1.6 mm Hg in control subjects, 6+/-1.1 mm Hg in orthostatic intolerance patients, 18+/-3.9 mm Hg in patients with essential hypertension, 31+/-3.4 mm Hg in patients with monogenic hypertension, and 25+/-3.4 mm Hg in patients with multiple system atrophy. Similar differences in sensitivities between groups were observed with nitroprusside. The sensitivity to vasoactive drugs was highly correlated with baroreflex buffering function and to a lesser degree with baroreflex control of heart rate. In control subjects, sensitivities to nitroprusside and phenylephrine infusions were correlated with baroreflex heart rate control and sympathetic nerve traffic. CONCLUSIONS: Our findings are consistent with an important effect of baroreflex blood pressure buffering on the sensitivity to vasoactive drugs. They suggest that even moderate changes in baroreflex function may have a substantial effect on the sensitivity to vasoactive medications.

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

2002-01-01

383

Nitrogen dynamics among cropland and riparian buffers: soil-landscape influences.  

PubMed

Nitrate (NO3-) leaching to ground water poses water quality concerns in some settings. Riparian buffers have been advocated to reduce excess ground water NO3- concentrations. We characterized inorganic N in soil solution and shallow ground water for 16 paired cropland-riparian plots from 2003 to 2005. The sites were located at two private dairy farms in Central New York on silt and gravelly silt loam soils (Aeric Endoaqualfs, Fluvaquentic Endoaquepts, Fluvaquentic Eutrudepts, Glossaquic Hapludalfs, and Glossic Hapludalfs). It was hypothesized that cropland N inputs and soil-landscape variability would jointly affect NO3- leaching and transformations in ground water. Results showed that well and moderately well drained fields had consistently higher ground water NO3- compared to more imperfectly drained fields receiving comparable N inputs. Average 50-cm depth soil solution NO3- and ground water dissolved oxygen (DO) explained 64% of average cropland ground water NO3- variability. Cropland ground water with an average DO of <3 mg L(-1) tended to have <4 mg L(-1) of NO3- with a water table depth (WTD) of buffers. More poorly drained buffers had low ground water NO3- and DO, a shallow WTD, and higher ground water ammonium and soil organic matter. Chloride patterns indicated that dilution was minor in most buffers, suggesting that denitrification losses were important. Soil-landscape factors strongly influenced NO3- behavior and suggest the importance of accurately characterizing soil variability along cropland-riparian zones. PMID:17485712

Young, Eric O; Briggs, Russell D

2007-01-01

384

Transferrins. Hen ovo-transferrin, interaction with bicarbonate and iron uptake.  

PubMed

Fe(III) uptake by the iron-delivery and iron-scavenging protein, hen ovotransferrin has been investigated in vitro between pH 6.5 and 9. In the absence of any ferric chelate, apo-ovotransferrin loses two protons with K1a = 50 +/- 1 nM and K2a = 4.0 +/- 0.1 nM. These acid-base equilibria are independent of the interaction of the protein with bicarbonate. The interaction with bicarbonate occurs with two different affinity constants, KC = 9.95 +/- 0.15 mM and KN = 110 +/- 10 mM. FeNAc3 exchanges its Fe(III) with the C-site of the protein in interaction with bicarbonate, direct rate constants k1 = 650 +/- 25 M-1 s-1, reverse rate constant k-1 = (6.0 +/- 0.1) x 10(3) M-1 s-1 and equilibrium constant K1 = 0.11 +/- 0.01. This iron-protein intermediate loses then a single proton, K3a = 3.50 +/- 0.35 nM, and undergoes a first change in conformation followed by a two or three proton loss, first order rate constant k2 = 0.30 +/- 0.01 s-1. This induces a new modification in conformation followed by the loss of one or two protons, first order rate constant k3 = (1.50 +/- 0.05) x 10(-2) s-1. These modifications in the monoferric protein conformation are essential for iron uptake by the N-site of the protein. In the last step, the monoferric and diferric proteins attain their final state of equilibrium in about 15,000 s. The overall mechanism of iron uptake by ovotransferrin is similar but not identical to those of serum transferrin and lactoferrin. The rates involved are, however, closer to lactoferrin than serum transferrin, whereas the affinities for Fe(III) are lower than those of serum transferrin and lactoferrin. Does this imply that the metabolic function transferrins is more related to kinetics than to thermodynamics? PMID:9990321

Bou Abdallah, F; el Hage Chahine, J M

1998-12-15

385

40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.  

Code of Federal Regulations, 2012 CFR

... false Quaternary ammonium salt of fluorinated alkylaryl amide...9075 Quaternary ammonium salt of fluorinated alkylaryl amide...generically as quaternary ammonium salt of fluorinated alkylaryl...f). (ii) Release to water. Requirements as...

2012-07-01

386

40 CFR 721.9075 - Quaternary ammonium salt of fluorinated alkylaryl amide.  

Code of Federal Regulations, 2013 CFR

... false Quaternary ammonium salt of fluorinated alkylaryl amide...9075 Quaternary ammonium salt of fluorinated alkylaryl amide...generically as quaternary ammonium salt of fluorinated alkylaryl...f). (ii) Release to water. Requirements as...

2013-07-01

387

40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.  

Code of Federal Regulations, 2011 CFR

...Applicability; description of the ammonium nitrate subcategory. 418.40 Section...MANUFACTURING POINT SOURCE CATEGORY Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions...

2011-07-01

388

40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the ammonium nitrate subcategory. 418.40 Section...MANUFACTURING POINT SOURCE CATEGORY Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions...

2013-07-01

389

40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.  

Code of Federal Regulations, 2012 CFR

...Applicability; description of the ammonium nitrate subcategory. 418.40 Section...MANUFACTURING POINT SOURCE CATEGORY Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions...

2012-07-01

390

40 CFR 418.40 - Applicability; description of the ammonium nitrate subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the ammonium nitrate subcategory. 418.40 Section...MANUFACTURING POINT SOURCE CATEGORY Ammonium Nitrate Subcategory § 418.40 Applicability; description of the ammonium nitrate subcategory. The provisions...

2010-07-01

391

78 FR 35258 - Solid Agricultural Grade Ammonium Nitrate from Ukraine: Continuation of Antidumping Duty Order  

Federal Register 2010, 2011, 2012, 2013

...A-823-810] Solid Agricultural Grade Ammonium Nitrate from Ukraine: Continuation of Antidumping...on solid agricultural grade ammonium nitrate from Ukraine would likely lead to continuation...Order: Solid Agricultural Grade Ammonium Nitrate from Ukraine, 66 FR 47451...

2013-06-12

392

Population of Nitrifying Bacteria and Nitrification in Ammonium Saturated Clinoptilolite  

NASA Technical Reports Server (NTRS)

As humans begin to spend longer periods of time in space, plants will be incorporated into life support systems. Ammonium saturated clinoptilolite is one plant growth substrate but a balance between ammonium and nitrate is needed. A laboratory study was conducted to determine effects of nitrifying bacteria on ammonium concentrations and kinetics of nitrification. Columns containing clinoptilolite substrate amended with nitrifying bacteria obtained from soil enrichment were analyzed weekly for a 90 day period. The enrichment culture initially contained 1 x 10(exp 5) ammonium oxidizing bacteria and 1 x 10(exp 2) nitrite oxidizing bacteria per gram of substrate. Populations of ammonium oxidizing bacteria increased to 1 x 10(exp 6) and nitrite oxidizing bacteria increased to 1 x 10(exp 3) per gram of substrate. The nitrification rate was approximately 0.25mg NO3(-)-N/kg.hr. Experiments were also conducted to enumerate nitrifying bacteria in a clinoptilolite substrate used to grow wheat (Triticum aestivum L.). Seventy days following the initial inoculation with an unknown number of commercial nitrifying bacteria, 1 x 10(exp 5) ammonium oxidizing bacteria per gram of substrate were present. The number of nitrite oxidizing bacteria was between 1 x 10(exp 3) to 10(exp 4) per gram of substrate as measured by the most probable number method. Nitrification rates were approximately 0.20mg NO3(-)-N/kg.hr. Clinoptilolite readily exchanged sufficient concentrations of ammonium to support nitrifying bacteria and they survived well in this medium.

McGilloway, R. L.; Weaver, R. W.; Ming, Douglas W.; Gruener, J.

1999-01-01

393

Effect of Beta alanine and sodium bicarbonate supplementation on repeated-sprint performance.  

PubMed

This study aimed to investigate if combining beta alanine (BA) and sodium bicarbonate (NaHCO3) supplementation could lead to enhanced repeated-sprint performance in team-sport athletes, beyond what is possible with either supplement alone. Participants (n = 24) completed duplicate trials of a repeated-sprint test (3 sets; 6 × 20 m departing every 25 seconds, 4 minutes active recovery between sets) and were then allocated into 4 groups as follows: BA only (n = 6; 28 days BA, acute sodium chloride placebo); NaHCO3 only (n = 6; 28 days glucose placebo, acute NaHCO3); BA/NaHCO3 (n = 6; 28 days BA, acute NaHCO3); placebo only (n = 6; 28 days glucose placebo, acute sodium chloride placebo), then completed duplicate trials postsupplementation. Sodium bicarbonate alone resulted in moderate effect size (d = 0.40-0.71) and "likely" and "very likely" benefit for overall total sprint times (TST) and for each individual set and for first sprint (sets 2 and 3) and best sprint time (sets 2 and 3). Combining BA and NaHCO3 resulted in "possible" to "likely" benefits for overall TST and for sets 2 and 3. First sprint (set 3) and best sprint time (sets 2 and 3) also showed "likely" benefit after this trial. The BA and placebo groups showed no differences in performance after supplementation. In conclusion, these results indicate that supplementation with acute NaHCO3 improved repeated-sprint performance more than either a combination of NaHCO3 and BA or BA alone. PMID:23524361

Ducker, Kagan J; Dawson, Brian; Wallman, Karen E

2013-12-01

394

Dynamic Volume Changes in Astrocytes Are an Intrinsic Phenomenon Mediated by Bicarbonate Ion Flux  

PubMed Central

Astrocytes, the major type of non-neuronal cells in the brain, play an important functional role in extracellular potassium ([K+]o) and pH homeostasis. Pathological brain states that result in [K+]o and pH dysregulation have been shown to cause astrocyte swelling. However, whether astrocyte volume changes occur under physiological conditions is not known. In this study we used two-photon imaging to visualize real-time astrocyte volume changes in the stratum radiatum of the hippocampus CA1 region. Astrocytes were observed to swell by 19.0±0.9% in response to a small physiological increase in the concentration of [K+]o (3 mM). Astrocyte swelling was mediated by the influx of bicarbonate (HCO3?) ions as swelling was significantly decreased when the influx of HCO3? was reduced. We found: 1) in HCO3? free extracellular solution astrocytes swelled by 5.4±0.7%, 2) when the activity of the sodium-bicarbonate cotransporter (NBC) was blocked the astrocytes swelled by 8.3±0.7%, and 3) in the presence of an extracellular carbonic anhydrase (CA) inhibitor astrocytes swelled by 11.4±0.6%. Because a significant HCO3? efflux is known to occur through the ?-amino-butyric acid (GABA) channel, we performed a series of experiments to determine if astrocytes were capable of HCO3? mediated volume shrinkage with GABA channel activation. Astrocytes were found to shrink ?7.7±0.5% of control in response to the GABAA channel agonist muscimol. Astrocyte shrinkage from GABAA channel activation was significantly decreased to ?5.0±0.6% of control in the presence of the membrane-permeant CA inhibitor acetazolamide (ACTZ). These dynamic astrocyte volume changes may represent a previously unappreciated yet fundamental mechanism by which astrocytes regulate physiological brain functioning. PMID:23226475

Florence, Clare M.; Baillie, Landon D.; Mulligan, Sean J.

2012-01-01

395

Bicarbonate Requirement for Elimination of the Lag Period of Hydrogenomonas eutropha  

PubMed Central

Carbon dioxide and oxygen concentrations have a profound effect on the lag period of chemoautotrophically grown Hydrogenomonas eutropha. Minimum lag periods and high growth rates were obtained in shaken flask cultures with a prepared gas mixture containing 70% H2, 20% O2, and 10% CO2. However, excessively long lag periods resulted when the same gas mixture was sparged through the culture. The lag period was shortened in sparged cultures by decreasing both the pO2 and the pCO2, indicating that gas medium equilibration had not occurred in shaken cultures. The lag period was completely eliminated at certain concentrations of O2 and CO2. The optimum pO2 was 0.05 atm, but the optimum pCO2 varied according to the pH of the medium and physiological age of the inoculum. At pH 6.4, the pCO2 required to obtain immediate growth of exponential, postexponential, and stationary phase inocula at equal specific rates was 0.02, 0.05, and 0.16 atm, respectively. With each 0.3-unit increase in the pH of the medium, a 50% decrease in the CO2 concentration was needed to permit growth to occur at the same rate. The pCO2 changes required to compensate for the pH changes of the medium had the net effect of maintaining a constant bicarbonate ion concentration. Initial growth of H. eutropha was therefore indirectly related to pCO2 and directly dependent upon a constant bicarbonate ion concentration. PMID:4999412

Repaske, Roy; Ambrose, Carol A.; Repaske, Anne C.; De Lacy, Margaret L.

1971-01-01

396

Root metabolic response of rice (Oryza sativa L.) genotypes with contrasting tolerance to zinc deficiency and bicarbonate excess.  

PubMed

Plants are routinely subjected to multiple environmental stresses that constrain growth. Zinc (Zn) deficiency and high bicarbonate are two examples that co-occur in many soils used for rice production. Here, the utility of metabolomics in diagnosing the effect of each stress alone and in combination on rice root function is demonstrated, with potential stress tolerance indicators identified through the use of contrasting genotypes. Responses to the dual stress of combined Zn deficiency and bicarbonate excess included greater root solute leakage, reduced dry matter production, lower monosaccharide accumulation and increased concentrations of hydrogen peroxide, phenolics, peroxidase and N-rich metabolites in roots. Both hydrogen peroxide concentration and root solute leakage were correlated with higher levels of citrate, allantoin and stigmasterol. Zn stress resulted in lower levels of the tricarboxylic acid (TCA) cycle intermediate succinate and the aromatic amino acid tyrosine. Bicarbonate stress reduced shoot iron (Fe) concentrations, which was reflected by lower Fe-dependent ascorbate peroxidase activity. Bicarbonate stress also favoured the accumulation of the TCA cycle intermediates malate, fumarate and succinate, along with the non-polar amino acid tyrosine. Genotypic differentiation revealed constitutively higher levels of D-gluconate, 2-oxoglutarate and two unidentified compounds in the Zn-efficient line RIL46 than the Zn-inefficient cultivar IR74, suggesting a possible role for these metabolites in overcoming oxidative stress or improving metal re-distribution. PMID:22526504

Rose, Michael T; Rose, Terry J; Pariasca-Tanaka, Juan; Yoshihashi, Tadashi; Neuweger, Heiko; Goesmann, Alexander; Frei, Michael; Wissuwa, Matthias

2012-10-01

397

Effect of sodium bicarbonate on aspirin-induced damage and potential difference changes in human gastric mucosa  

Microsoft Academic Search

Two aspirin tablets in 100 ml fluid will produce microscopical damage to the human stomach. A study was performed to determine whether a small amount of sodium bicarbonate (equivalent to one-third of a teaspoonful of baking soda) could protect against this damage. Sequential gastric biopsy specimens were taken from 15 healthy subjects before, during, and after intragastric instillation of one

Bruce K Bowen; William J Krause; Kevin J Ivey

1977-01-01

398

Buffer control technique for video coding  

NASA Astrophysics Data System (ADS)

In this work we develop an adaptive scheme for quantization of subband or transform coded frames in a typical video sequence coder. Using a simple statistical model for the subband or transform coefficients, we present a procedure to determine the optimum dead-zone quantizer for a given entropy of the quantizer output symbols. We find that, at low bit rates, the dead- zone quantizer offers better performance than the uniform quantizer. The model is used to develop an adaptive procedure to update the quantizer parameters on the basis of the state of a channel buffer with constant output rate and variable input rate. Experimental results show that the model can be effectively used in a practical scheme for buffer control.

Calvagno, Giancarlo; Ghirardi, C.; Mian, Gian A.; Rinaldo, R.

1995-02-01

399

Spacecraft optical disk recorder memory buffer control  

NASA Technical Reports Server (NTRS)

This paper discusses the research completed under the NASA-ASEE summer faculty fellowship program. The project involves development of an Application Specific Integrated Circuit (ASIC) to be used as a Memory Buffer Controller (MBC) in the Spacecraft Optical Disk System (SODR). The SODR system has demanding capacity and data rate specifications requiring specialized electronics to meet processing demands. The system is being designed to support Gigabit transfer rates with Terabit storage capability. The complete SODR system is designed to exceed the capability of all existing mass storage systems today. The ASIC development for SODR consist of developing a 144 pin CMOS device to perform format conversion and data buffering. The final simulations of the MBC were completed during this summer's NASA-ASEE fellowship along with design preparations for fabrication to be performed by an ASIC manufacturer.

Hodson, Robert F.

1993-01-01

400

Mechanisms of CFTR functional variants that impair regulated bicarbonate permeation and increase risk for pancreatitis but not for cystic fibrosis.  

PubMed

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p?=?0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system. PMID:25033378

LaRusch, Jessica; Jung, Jinsei; General, Ignacio J; Lewis, Michele D; Park, Hyun Woo; Brand, Randall E; Gelrud, Andres; Anderson, Michelle A; Banks, Peter A; Conwell, Darwin; Lawrence, Christopher; Romagnuolo, Joseph; Baillie, John; Alkaade, Samer; Cote, Gregory; Gardner, Timothy B; Amann, Stephen T; Slivka, Adam; Sandhu, Bimaljit; Aloe, Amy; Kienholz, Michelle L; Yadav, Dhiraj; Barmada, M Michael; Bahar, Ivet; Lee, Min Goo; Whitcomb, David C

2014-07-01

401

Mechanisms of CFTR Functional Variants That Impair Regulated Bicarbonate Permeation and Increase Risk for Pancreatitis but Not for Cystic Fibrosis  

PubMed Central

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p?=?0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system. PMID:25033378

Lewis, Michele D.; Park, Hyun Woo; Brand, Randall E.; Gelrud, Andres; Anderson, Michelle A.; Banks, Peter A.; Conwell, Darwin; Lawrence, Christopher; Romagnuolo, Joseph; Baillie, John; Alkaade, Samer; Cote, Gregory; Gardner, Timothy B.; Amann, Stephen T.; Slivka, Adam; Sandhu, Bimaljit; Aloe, Amy; Kienholz, Michelle L.; Yadav, Dhiraj; Barmada, M. Michael; Bahar, Ivet; Lee, Min Goo; Whitcomb, David C.

2014-01-01

402

How Close Is Safe? Buffer Zone Development  

NSDL National Science Digital Library

The effects of volcanoes on both the environment and people are the focus of this investigation. Students are introduced to the term "buffer" and are tasked with creating a possible buffer zone around Mount St. Helens. Students begin by assigning 32 pre-written statements related to volcanoes into categories of cause, effect and human responses. The chart, along with true-color and false-color LandSat images from 1980 and 1999, are used to study the eruption of Mount St. Helens to determine that possible buffer zone. The URL opens to the investigation directory, with links to teacher and student materials, lesson extensions, resources, teaching tips, and assessment strategies. As the first investigation in this module entitled, "Volcanoes- Local Hazard, Global Issue," the teacher's guide will begin with a two-page module overview and list of all standards addressed. This is Investigation 1 of three found in the Grades 5-8 Module 1 of Mission Geography. The Mission Geography curriculum integrates data and images from NASA missions with the National Geography Standards. Each of the three investigations in Module 1, while related, can be done independently.

403

Separation of Trivalent Actinides from Lanthanides in an Acetate Buffer Solution Using Cyanex 301  

SciTech Connect

The separation of trivalent actinides from the lanthanides using the active extractant in the Cyanex 301 reagent, bis(2,4,4-trimethylpentyl)dithiophosphinic acid, was studied. Specifically, the extractant was studied for an ammonium acetate/acetic acid buffered feed that would result from a transuranic separation process utilizing an ammonium acetate strip solution. Separation factors of 241Am from 154Eu with this extractant, as a function of total acetate concentration and pH, have been measured. Additionally, the extraction behavior of stable La, Ce, Pr, Nd, Sm, and Eu was measured. Separation factors were typically very high for Am from Eu at a pH ranging from 3.8 to 5.8 and a total acetate concentration ranging from 0.2 M to 1.0 M. However, separation factors across the lanthanide series varied considerably and resulted in separation of the lighter lanthanides from the heavier lanthanides at the higher pH’s.

Jack D. Law; Dean R. Peterman; Terry A. Todd; Richard D. Tillotson

2006-05-01

404

META-ANALYSIS OF NITROGEN REMOVAL IN RIPARIAN BUFFERS  

EPA Science Inventory

Riparian buffer zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Riparian buffer width may be positively related to nitrogen removal effectiveness by influencing nitrog...

405

Sizing Multiple Buffer Pools for A thesis submitted to the  

E-print Network

objects to buffer pools and the setting the size for each of the buffer pools, is crucial for achieving wife, Jie Lu, for their love, support, and encouragement in these years. #12;iii Contents Abstract

406

Efficient buffer design algorithms for production line profit maximization  

E-print Network

A production line is a manufacturing system where machines are connected in series and separated by buffers. The inclusion of buffers increases the average production rate of the line by limiting the propagation of ...

Shi, Chuan, Ph. D. Massachusetts Institute of Technology

2012-01-01

407

Detecting buffer overflows using testcase synthesis and code instrumentation  

E-print Network

The research presented in this thesis aims to improve existing approaches to dynamic buffer overflow detection by developing a system that utilizes code instrumentation and adaptive test case synthesis to find buffer ...

Zhivich, Michael A

2005-01-01

408

Contamination of Ammonium-Based Nutrient Solutions by Nitrifying Organisms and the Conversion of Ammonium to Nitrate.  

PubMed Central

Conversion of ammonium to nitrate and contamination by nitrifying organisms are often assumed not to be significant in ammonium-based nutrient solutions. To assess this assumption, maize (Zea mays) and pea (Pisum sativum) were grown under greenhouse conditions in aeroponic, hydroponic, and sand-culture systems containing 2 mM ammonium chloride as the sole nitrogen source and evaluated for the activity of contaminating nitrifying organisms. In all three culture systems, root colonization by nitrifying organisms was detected within 5 d, and nitrate was detected in the nutrient solution within 10 d after seedling transfer. In sand culture, solution nitrate concentration reached 0.35 mM by the end of the 17-d experiment. Consistent with the microbial ammonium oxidation sequence, nitrite was detected earlier than nitrate and remained at lower levels throughout the experiment. Nitrate was found in significant quantities in root and shoot tissues from seedlings grown in ammonium-based nutrient solutions in all of the solution culture systems. Maize seedlings grown in an ammonium-based hydroponic system contained nitrate concentrations at 40% of that found in plants grown in nitrate-based solution. Determination of nitrate (or nitrite) levels in the nutrient solution was the weakest indicator of the activity of nitrifying organisms. A bioassay for the presence of nitrifying organisms in combination with tissue analysis for nitrate was a better indicator of microbial conversion of ammonium to nitrate in nutrient solution culture. The results have implications for the use of ammonium-based nutrient solutions to obtain plants suitable for research on induction of nitrate uptake and reduction or for research using solution culture to compare ammonium versus nitrate fertilization. PMID:12231673

Padgett, P. E.; Leonard, R. T.

1993-01-01

409

The A -buffer, an antialiased hidden surface method  

Microsoft Academic Search

The A-buffer (anti-aliased, area-averaged, accumulation buffer) is a general hidden surface mechanism suited to medium scale virtual memory computers. It resolves visibility among an arbitrary collection of opaque, transparent, and intersecting objects. Using an easy to compute Fourier window (box filter), it increases the effective image resolution many times over the Z-buffer, with a moderate increase in cost. The A-buffer

Loren Carpenter

1984-01-01

410

21 CFR 73.2298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2010 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive ferric ammonium ferrocyanide...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2010-04-01

411

Dry process fluorination of uranium dioxide using ammonium bifluoride  

E-print Network

An experimental study was conducted to determine the practicality of various unit operations for fluorination of uranium dioxide. The objective was to prepare ammonium uranium fluoride double salts from uranium dioxide and ...

Yeamans, Charles Burnett, 1978-

2003-01-01

412

Formation of urea and guanidine by irradiation of ammonium cyanide.  

NASA Technical Reports Server (NTRS)

Aqueous solutions of ammonium cyanide yield urea, cyanamide and guanidine when exposed to sunlight or an unfiltered 254 nm ultraviolet source. The prebiotic significance of these results is discussed.

Lohrmann, R.

1972-01-01

413

Wastewater purification to remove ammonium ions by the oxidation method  

Microsoft Academic Search

Wastewater purification to remove ammonium ions and carbamide by oxidation with hypochlorites of alkali and alkaline-earth\\u000a metals was studied. The effect of various factors on the degree of purification was examined experimentally.

S. A. Lobanov; V. Z. Poilov; A. V. Sofronova

2006-01-01

414

21 CFR 73.2298 - Ferric ammonium ferrocyanide.  

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive ferric ammonium ferrocyanide...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2014-04-01

415

21 CFR 73.2298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2012 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive ferric ammonium ferrocyanide...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2012-04-01

416

21 CFR 73.2298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2013 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive ferric ammonium ferrocyanide...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2013-04-01

417

21 CFR 73.2298 - Ferric ammonium ferrocyanide.  

Code of Federal Regulations, 2011 CFR

...GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION...specifications. The color additive ferric ammonium ferrocyanide...amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture...

2011-04-01

418

Direct esterification of ammonium salts of carboxylic acids  

DOEpatents

A non-catalytic process for producing esters, the process comprising reacting an ammonium salt of a carboxylic acid with an alcohol and removing ammonia from the reaction mixture. Selectivities for the desired ester product can exceed 95 percent.

Halpern, Yuval (Skokie, IL)

2003-06-24

419

Ammonium ylides for the diastereoselective synthesis of glycidic amides†  

PubMed Central

A highly trans-selective protocol for the synthesis of glycidic amides was developed. This approach gave access to oxiranes by reacting stabilised ammonium ylides bearing an ?-carbonyl group and aromatic aldehydes in moderate to good yields. PMID:21180720

Waser, Mario; Herchl, Richard; Muller, Norbert

2014-01-01

420

On Buffer Limited Congestion Window Dynamics and Packet Loss  

Microsoft Academic Search

The central result of this paper is an analytic formula describing the packet loss probability in a buffer as a function of the length of the buffer and the probability of external packet loss. This formula makes it possible to calculate the total loss along a multi-buffer, multi-link route. Also, new types of congestion win- dow distributions are discovered when

A. Fekete; G. Vattay

2001-01-01

421

Centralized Buffer Router with Elastic Links and Bubble Flow Control  

E-print Network

Centralized Buffer Router with Elastic Links and Bubble Flow Control Syed Minhaj Hassan Georgia: sudha@ece.gatech.edu Abstract--While router buffers have been used as performance multipliers elastic bubble router - a router micro-architecture based on the use of centralized buffers (CB

Lee, Hsien-Hsin "Sean"

422

Energy management using buffer memory for streaming data  

Microsoft Academic Search

This work presents a new approach for energy management by inserting data buffers. The buffers are managed using the concept of inventory control by treating energy as cost and computation as production. The data stored in the buffers are considered as merchandise. Our method provides a mathematical framework to develop general strategies managing the energy consumption in computers. The approach

Le Cai; Yung-hsiang Lu

2005-01-01

423

CS281: Systems Programming Programming Lab Assignment: The Buffer Bomb  

E-print Network

CS281: Systems Programming Programming Lab Assignment: The Buffer Bomb Introduction This assignment You can obtain your buffer bomb by pointing your Web browser at: http the following three executable files: bufbomb: The buffer bomb program you will attack. 1 #12;makecookie

Kretchmar, R. Matthew

424

Delineation of Preventative Landslide Buffers Along Steep Streamside Slopes in  

E-print Network

213 Delineation of Preventative Landslide Buffers Along Steep Streamside Slopes in Northern Co (GDRCo) applies tree retention buffers to steep slopes along fish bearing (Class I) and non with timber harvest plans. These Steep Streamside Slope (SSS) buffers were designed to reduce the amount

Standiford, Richard B.

425

Buffer block planning for interconnect-driven floorplanning  

Microsoft Academic Search

This paper studies buffer block planning for interconnect-driven floorplanning in deep submicron designs. We first introduce the concept of feasible region (FR) for buffer insertion, and derive closed-form formula for FR. We observe that the FR for a buffer is quite large in general even under fairly tight delay constraint. Therefore, FR gives us a lot of flexibility to plan

Jason Cong; Tianming Kong; David Zhigang Pan

1999-01-01

426

Box Calculus with High-Level Buffers Ccile Bui Thanh  

E-print Network

Box Calculus with High-Level Buffers Cécile Bui Thanh LACL, Université Paris 12 61 avenue du: Process algebra, handshake/buffered commu- nication, structured operational semantics, coloured Petri nets both handshake and buffered communication. This allows a sim- ple and compositional expression

Paris-Sud XI, Université de

427

Exact Analysis of Single-Wavelength Optical Buffers With Feedback  

E-print Network

Exact Analysis of Single-Wavelength Optical Buffers With Feedback Markov Fluid Queues Huseyin Emre Kankaya and Nail Akar Abstract--Optical buffering via fiber delay lines is used for contention resolution the blocking probabili- ties in an asynchronous single-wavelength optical buffer. Packet lengths are assumed

Akar, Nail

428

PERFORMANCE ANALYSIS OF NETWORKS OF OPEN ZERO-BUFFER  

E-print Network

PERFORMANCE ANALYSIS OF NETWORKS OF OPEN ZERO-BUFFER MULTI-SERVER QUEUES Frederico R. B. Cruz (UFMG) fcruz@est.ufmg.br In this paper we aim to accurately evaluate the performance of open zero-buffer multi to 09 October - 2009 #12;2 1. Introduction and Motivation Networks of finite queues without buffers

Cruz, Frederico

429

Predicting buffer hit ratios with neural networks Uli Harder  

E-print Network

Predicting buffer hit ratios with neural networks Uli Harder and Tim MacLeod September 18, 2003 Abstract A neural network is used to predict the buffer hit ratio in an Oracle database, given the access pattern and buffer size. 1 Introduction Neural networks have come and gone into fashion several times over

Imperial College, London

430

Quantification of the Effects of Organic and Carbonate Buffers on  

E-print Network

Quantification of the Effects of Organic and Carbonate Buffers on Arsenate and Phosphate Adsorption evaluation of their adsorptive capacities. Here, we systematically investigate the effects of buffer (HEPES as a buffer. At low aqueous arsenate and phosphate concentration (1.3 µM), however

Sverjensky, Dimitri A.

431

Optimizing buffer sizes for pipeline workflow scheduling with setup times  

E-print Network

Optimizing buffer sizes for pipeline workflow scheduling with setup times Anne Benoit1, Jean and homogeneous buffers are available for the storage of intermediate results. In this kind of applications, several computation stages are interconnected as a linear application graph, and each stage holds a buffer

Benoit, Anne

432

Buffer Layer Assisted Laser Patterning of Metals on Surfaces  

E-print Network

Buffer Layer Assisted Laser Patterning of Metals on Surfaces Gabriel Kerner and Micha Asscher, variable width metallic wires. By employing laser desorption of a physisorbed buffer gas, a grating of gold controlled metallic clusters via buffer layer assisted growth (BLAG).9-11 To create clusters, the metal

Asscher, Micha

433

Optimal Buffer Management Policies for Delay Tolerant Networks  

E-print Network

Optimal Buffer Management Policies for Delay Tolerant Networks Amir Krifa, Chadi Barakat proposed the use of store-carry-and-forward protocols: there, a node may store a message in its buffer). Thus, efficient buffer manage- ment policies are necessary to decide which messages should be discarded

Paris-Sud XI, Université de

434

PointGuardTM: Protecting Pointers From Buffer Overflow Vulnerabilities  

Microsoft Academic Search

Despite numerous security technologies crafted to resist buffer overflow vulnerabilities, buffer overflows continue to be the dominant form of software security vulnerability. This is because most buffer overflow defenses provide only partial coverage, and the attacks have adapted to exploit problems that are not well-defended, such as heap over- flows. This paper presents PointGuard, a compiler technique to defend against

Crispin Cowan; Steve Beattie; John Johansen; Perry Wagle

2003-01-01

435

Optimal Buffer Allocation in Production Lines Using an Automata Search  

E-print Network

Optimal Buffer Allocation in Production Lines Using an Automata Search Tolga Tezcan Abhijit Gosavi, to solve the optimal buffer allocation problem in production lines. We have incorporated the search optimization problems. In this paper, we use an LA based search technique for finding the optimal buffer sizes

Gosavi, Abhijit

436

On the performance of greedy algorithms in packet buffering  

Microsoft Academic Search

We study a basic buffer management problem that arises in network switches. Consider m input ports, each of which is equipped with a buffer (queue) of limited capacity. Data packets arrive online and can be stored in the buffers if space permits; otherwise packet loss occurs. In each time step the switch can transmit one packet from one of the

Susanne Albers; Markus Schmidt

2004-01-01

437

A fair queueing architecture for ATM switches with input buffers  

Microsoft Academic Search

The available bit rate (ABR) and unspecified bit rate (UBR) are reservationless service categories at the ATM layer. ATM switches are required to have large cell buffers to provide such services. A new queueing architecture named Kago for the large input buffer switch is proposed. Kago provides per-VC fair scheduling among the multiple input buffers. The mechanism is divided among

Yosliiniitsu Shimojo; Toshiba Corp

1996-01-01

438

Meta-Analysis of Nitrogen Removal in Riparian Buffers  

Microsoft Academic Search

Riparian buffers, the vegetated region adjacent to streams and wet- lands, are thought to be effective at intercepting and reducing nitrogen loads entering water bodies. Riparian buffer width is thought to be positively related to nitrogen removal effectiveness by influencing nitrogen retention or removal. We surveyed the scientific literature containing data on riparian buffers and nitrogen concentration in streams and

Paul M. Mayer; Steven K. Reynolds; Marshall D. McCutchen; Timothy J. Canfield

2007-01-01

439

Methods to Stabilize and Destabilize Ammonium Borohydride  

SciTech Connect

Ammonium borohydride, NH4BH4, has a high hydrogen content of ?m = 24.5 wt% H2 and releases 18 wt% H2 below T = 160 °C. However, the half-life of bulk NH4BH4 at ambient temperatures, ~6 h, is insufficient for practical applications. The decomposition of NH4BH4 (ABH2) was studied at variable hydrogen and argon back pressures to investigate possible pressure mediated stabilization effects. The hydrogen release rate from solid ABH2 at ambient temperatures is reduced by ~16 % upon increasing the hydrogen back pressure from 5 to 54 bar. Similar results were obtained using argon pressure and the observed stabilization may be explained by a positive volume of activation in the transition state leading to hydrogen release. Nanoconfinement in mesoporous silica, MCM-41, was investigated as alternative means to stabilize NH4BH4. However, other factors appear to significantly destabilize NH4BH4 and it rapidly decomposes at ambient temperatures into [(NH3)2BH2][BH4] (DADB) in accordance with the bulk reaction scheme. The hydrogen desorption kinetics from nanoconfined [(NH3)2BH2][BH4] is moderately enhanced as evidenced by a reduction in the DSC decomposition peak temperature of ?T = -13 °C as compared to the bulk material. Finally, we note a surprising result, storage of DADB at temperature < -30 °C transformed, reversibly, the [(NH3)2BH2][BH4] into a new low temperature polymorph as revealed by both XRD and solid state MAS 11B MAS NMR. TA & AK are thankful for support from the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. A portion of the research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle.

Nielsen, Thomas K.; Karkamkar, Abhijeet J.; Bowden, Mark E.; Besenbacher, Fleming; Jensen, Torben R.; Autrey, Thomas

2013-01-21

440

Thermal Decomposition Behavior of Ammonium Perchlorate and of an Ammonium-Perchlorate-Based Composite Propellant  

NASA Technical Reports Server (NTRS)

The thermal decomposition of ammonium perchlorate (AP) and ammonium-perchlorate-based composite propellants is studied using the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) technique. The main objective of the present work is to evaluate whether the STMBMS can provide new data on these materials that will have sufficient detail on the reaction mechanisms and associated reaction kinetics to permit creation of a detailed model of the thermal decomposition process. Such a model is a necessary ingredient to engineering models of ignition and slow-cookoff for these AP-based composite propellants. Results show that the decomposition of pure AP is controlled by two processes. One occurs at lower temperatures (240 to 270 C), produces mainly H2O, O2, Cl2, N2O and HCl, and is shown to occur in the solid phase within the AP particles. 200(micro) diameter AP particles undergo 25% decomposition in the solid phase, whereas 20(micro) diameter AP particles undergo only 13% decomposition. The second process is dissociative sublimation of AP to NH3 + HClO4 followed by the decomposition of, and reaction between, these two products in the gas phase. The dissociative sublimation process occurs over the entire temperature range of AP decomposition, but only becomes dominant at temperatures above those for the solid-phase decomposition. AP-based composite propellants are used extensively in both small tactical rocket motors and large strategic rocket systems.

Behrens, R.; Minier, L.

1998-01-01

441

ATS (ammonium thiosulfate) Claus tail-gas cleanup process  

Microsoft Academic Search

The ATS (ammonium thiosulfate) Claus tail-gas cleanup process was developed by the Pritchard Corp. and installed for Colorado Interstate Gas Corp. (CIG) and Wycon Chemical Co. at CIG's Table Rock, Wyo., natural gas-treatment plant to process tail gas from an 80 ton\\/day Claus plant. The new unit will produce 18,140 tons\\/yr of ammonium thiosulfate fertilizer solution. In the first, absorption

A. Zey; S. White; D. Johnson

1980-01-01

442

Nitric oxide controls nitrate and ammonium assimilation in Chlamydomonas reinhardtii.  

PubMed

Nitrate and ammonium are major inorganic nitrogen sources for plants and algae. These compounds are assimilated by means of finely regulated processes at transcriptional and post-translational levels. In Chlamydomonas, the expression of several genes involved in high-affinity ammonium (AMT1.1, AMT1.2) and nitrate transport (NRT2.1) as well as nitrate reduction (NIA1) are downregulated by ammonium through a nitric oxide (NO)-dependent mechanism. At the post-translational level, nitrate/nitrite uptake and nitrate reductase (NR) are also inhibited by ammonium, but the mechanisms implicated in this regulation are scarcely known. In this work, the effect of NO on nitrate assimilation and the high-affinity ammonium uptake was addressed. NO inhibited the high-affinity uptake of ammonium and nitrate/nitrite, as well as the NR activity, in a reversible form. In contrast, nitrite reductase and glutamine synthetase activities were not affected. The in vivo and in vitro studies suggested that NR enzyme is inhibited by NO in a mediated process that requires the cell integrity. These data highlight a role of NO in inorganic nitrogen assimilation and suggest that this signalling molecule is an important regulator for the first steps of the pathway. PMID:23918969

Sanz-Luque, Emanuel; Ocaña-Calahorro, Francisco; Llamas, Angel; Galvan, Aurora; Fernandez, Emilio

2013-08-01

443

Anaerobic ammonium oxidation by anammox bacteria in the Black Sea  

NASA Astrophysics Data System (ADS)

The availability of fixed inorganic nitrogen (nitrate, nitrite and ammonium) limits primary productivity in many oceanic regions. The conversion of nitrate to N2 by heterotrophic bacteria (denitrification) is believed to be the only important sink for fixed inorganic nitrogen in the ocean. Here we provide evidence for bacteria that anaerobically oxidize ammonium with nitrite to N2 in the world's largest anoxic basin, the Black Sea. Phylogenetic analysis of 16S ribosomal RNA gene sequences shows that these bacteria are related to members of the order Planctomycetales performing the anammox (anaerobic ammonium oxidation) process in ammonium-removing bioreactors. Nutrient profiles, fluorescently labelled RNA probes, 15N tracer experiments and the distribution of specific `ladderane' membrane lipids indicate that ammonium diffusing upwards from the anoxic deep water is consumed by anammox bacteria below the oxic zone. This is the first time that anammox bacteria have been identified and directly linked to the removal of fixed inorganic nitrogen in the environment. The widespread occurrence of ammonium consumption in suboxic marine settings indicates that anammox might be important in the oceanic nitrogen cycle.

Kuypers, Marcel M. M.; Sliekers, A. Olav; Lavik, Gaute; Schmid, Markus; Jørgensen, Bo Barker; Kuenen, J. Gijs; Sinninghe Damsté, Jaap S.; Strous, Marc; Jetten, Mike S. M.

2003-04-01

444

Buffer insertion is an increasingly critical optimization for achieving timing closure, and the number of buffers required  

E-print Network

ABSTRACT Buffer insertion is an increasingly critical optimization for achieving timing closure, and the number of buffers required increases significantly with technology migration. It is imperative for an automated buffer insertion algorithm to be able to efficiently optimize tens of thousands of nets. One must

Hu, Jiang

445

Buffer for a gamma-insensitive optical sensor with gas and a buffer assembly  

DOEpatents

A buffer assembly for a gamma-insensitive gas avalanche focal plane array operating in the ultra-violet/visible/infrared energy wavelengths and using a photocathode and an avalanche gas located in a gap between an anode and the photocathode. The buffer assembly functions to eliminate chemical compatibility between the gas composition and the materials of the photocathode. The buffer assembly in the described embodiment is composed of two sections, a first section constructed of glass honeycomb under vacuum and a second section defining a thin barrier film or membrane constructed, for example, of Al and Be, which is attached to and supported by the honeycomb. The honeycomb section, in turn, is supported by and adjacent to the photocathode.

Kruger, Hans W. (Walnut Creek, CA)

1994-01-01

446

Buffer for a gamma-insensitive optical sensor with gas and a buffer assembly  

DOEpatents

A buffer assembly is disclosed for a gamma-insensitive gas avalanche focal plane array operating in the ultra-violet/visible/infrared energy wavelengths and using a photocathode and an avalanche gas located in a gap between an anode and the photocathode. The buffer assembly functions to eliminate chemical compatibility between the gas composition and the materials of the photocathode. The buffer assembly in the described embodiment is composed of two sections, a first section constructed of glass honeycomb under vacuum and a second section defining a thin barrier film or membrane constructed, for example, of Al and Be, which is attached to and supported by the honeycomb. The honeycomb section, in turn, is supported by and adjacent to the photocathode. 7 figures.

Kruger, H.W.

1994-05-10

447

Hybrid Silicon AWG Lasers and Buffers  

NASA Astrophysics Data System (ADS)

Silicon photonics promises the low cost integration of optical components with CMOS electronics thus enabling optical interconnects in future generation processors. The hybrid silicon platform (HSP) is one approach to make optically active components on silicon. While many optical components on the HSP have been demonstrated, few photonic integrated circuits (PICs), consisting of multiple elements, have been demonstrated. In this dissertation, two Hybrid Silicon PICs and their building blocks will be presented. The first PIC to be presented is a multiwavelength laser based on an AWG. It consists of Fabry-Perot cavities integrated with hybrid silicon amplifiers and an intracavity filter in the form of an AWG with a channel spacing of 360 GHz. Four-channel lasing operation is shown. Single-sided fiber-coupled output powers as high as 35 µW are measured. The SMSR is as high as 35 dB. Various device characteristics are compromised as the AWG was attacked during the III-V process, thus showing the need to properly protect passive components during III-V processing. The second PIC to be presented is a fully integrated optical buffer. The device consists of a hybrid silicon switch, a 1.1 m long silicon waveguide, and cascaded hybrid silicon amplifiers. The passive delay line is protected by dielectric layers to limit passive losses to 0.5 dB/cm. Noise filters in the form of saturable absorbers are integrated in the buffer to allow for a larger number of recirculations in the delay line compared to a delay without filters. Tapers are used to transition the mode from the passive region to the hybrid region with losses as low as 0.22 dB per transition and reflectivities below -35 dB. Error free operation of the hybrid silicon switch is demonstrated in all four paths. The integrated buffer failed due to low yield, showing the current limitations of the HSP.

Kurczveil, Geza

448

Spacecraft optical disk recorder memory buffer control  

NASA Technical Reports Server (NTRS)

The goal of this project is to develop an Application Specific Integrated Circuit (ASIC) for use in the control electronics of the Spacecraft Optical Disk Recorder (SODR). Specifically, this project is to design an extendable memory buffer controller ASIC for rate matching between a system Input/Output port and the SODR's device interface. The aforementioned goal can be partitioned into the following sub-goals: (1) completion of ASIC design and simulation (on-going via ASEE fellowship); (2) ASIC Fabrication (at ASIC manufacturer); and (3) ASIC Testing (NASA/LaRC, Christopher Newport University).

Hodson, Robert F.

1992-01-01

449

Branch target buffer design and optimization  

NASA Technical Reports Server (NTRS)

Consideration is given to two major issues in the design of branch target buffers (BTBs), with the goal of achieving maximum performance for a given number of bits allocated to the BTB design. The first issue is BTB management; the second is what information to keep in the BTB. A number of solutions to these problems are reviewed, and various optimizations in the design of BTBs are discussed. Design target miss ratios for BTBs are developed, making it possible to estimate the performance of BTBs for real workloads.

Perleberg, Chris H.; Smith, Alan J.

1993-01-01

450

Seasonal buffering of atmospheric pressure on Mars  

NASA Technical Reports Server (NTRS)

An isothermal reservoir of carbon dioxide in gaseous contact with the Martian atmosphere would reduce the amplitude and advance the phase of global atmospheric pressure fluctuations caused by seasonal growth and decline of polar CO2 frost caps. Adsorbed carbon dioxide in the upper roughly 10 m of Martian regolith is sufficient to buffer the present atmosphere on a seasonal basis. Available observations and related polar cap models do not confirm or refute the operation of such a mechanism. Implications for the amplitude and phase of seasonal pressure fluctuations are subject to direct test by the upcoming Viking mission to Mars.

Dzurisin, D.; Ingersoll, A. P.

1975-01-01

451

A Buffer Management Issue in Designing SSDs for LFSs  

NASA Astrophysics Data System (ADS)

This letter introduces a buffer management issue in designing SSDs for log-structured file systems (LFSs). We implemented a novel trace-driven SSD simulator in SystemC language, and simulated several SSD architectures with the NILFS2 trace. From the results, we give two major considerations related to the buffer management as follows. (1) The write buffer is used as a buffer not a cache, since all write requests are sequential in NILFS2. (2) For better performance, the main architectural factor is the bus bandwidth, but 332MHz is enough. Instead, the read buffer makes a key role in performance improvement while caching data. To enhance SSDs, accordingly, it is an effective way to make efficient read buffer management policies, and one of the examples is tracking the valid data zone in NILFS2, which can increase the data hit ratio in read buffers significantly.

Kim, Jaegeuk; Seol, Jinho; Maeng, Seungryoul

452

A sensitive negative-ion electrospray ionization mass spectrometry detection for metallothionein in tris(hydroxymethyl)aminomethane acetate buffer  

NASA Astrophysics Data System (ADS)

Although positive-ion (PI) electrospray ionisation mass spectrometry (ESI-MS) has been usually applied for the analysis of native metallothioneins (MT) isoforms binding with metal ions, it suffers from the lack of insensitivity under neural conditions because of the low efficiency of protonation during ESI process. In this study, multiply deprotonated metallothionein (Zn7-MT-2a), produced from tris(hydroxymethyl)aminomethane (TRIS) acetate solutions under near neutral condition, was analyzed by negative-ion (NI) ESI-MS. Compared with the ammonium acetate buffer system which has been normally used for ESI-MS experiments, the use of TRIS acetate buffer results in the formation of more abundant ions and higher charge states of MT-2a, and consequently higher intensity is attained. The sensitivity enhancement of the system could be explained by the high gas-phase proton affinity, small molecular volume of the anion (acetate), and the high hydrogen consumption by TRIS in the buffer system, which would all favor the deprotonation of the analyte during NI-ESI process. Factors that may affect the NI-ESI responses, such as acid added in buffer, pH and concentration of TRIS acetate had been evaluated, and the result showed that using acetic acid, lower pH under the pH range evaluated, higher concentration of TRIS acetate all favored the MS detection of MT-2a. Our finding sheds light on a buffer system that may offer substantial sensitivity advantages in the studying of weakly bound, non-covalent complexes such as metal binding MTs, which are usually analyzed under near neutral conditions.

Shen, Jin-Can; Lu, Su-Ge; Zhuang, Zhi-Xia; Wang, Xiao-Ru; Lee, Frank S. C.

2005-05-01

453

Bicarbonate-sensing soluble adenylyl cyclase is an essential sensor for acid/base homeostasis  

PubMed Central

pH homeostasis is essential for life, yet it remains unclear how animals sense their systemic acid/base (A/B) status. Soluble adenylyl cyclase (sAC) is an evolutionary conserved signaling enzyme that produces the second messenger cAMP in response to bicarbonate ions (HCO3?). We cloned the sAC ortholog from the dogfish, a shark that regulates blood A/B by absorbing and secreting protons (H+) and HCO3? at its gills. Similar to mammalian sAC, dogfish soluble adenylyl cyclase (dfsAC) is activated by HCO3? and can be inhibited by two structurally and mechanistically distinct small molecule inhibitors. dfsAC is expressed in the gill epithelium, where the subset of base-secreting cells resides. Injection of inhibitors into animals under alkaline stress confirmed that dfsAC is essential for maintaining systemic pH and HCO3? levels in the whole organism. One of the downstream effects of dfsAC is to promote the insertion of vacuolar proton pumps into the basolateral membrane to absorb H+ into the blood. sAC orthologs are present throughout metazoans, and mammalian sAC is expressed in A/B regulatory organs, suggesting that systemic A/B sensing via sAC is widespread in the animal kingdom. PMID:20018667

Tresguerres, Martin; Parks, Scott K.; Salazar, Eric; Levin, Lonny R.; Goss, Greg G.; Buck, Jochen

2009-01-01

454

Enzymatic Conversion of CO2 to Bicarbonate in Functionalized Mesoporous Silica  

SciTech Connect

We report here that carbonic anhydrase (CA), the fastest enzyme that can covert carbon dioxide to bicarbonate, can be spontaneously entrapped in functionalized mesoporous silica (FMS) with super-high loading density (up to 0.5 mg of protein/mg of FMS) due to the dominant electrostatic interaction. The binding of CA to HOOC-FMS can result in the protein’s conformational change comparing to the enzyme free in solution, but can be overcome with increased protein loading density. The higher the protein loading density, the less conformational change, hence the higher enzymatic activity and the higher enzyme immobilization efficiency. The electrostatically bound CA can be released by changing pH. The released enzyme still displayed the native conformational structure and the same high enzymatic activity as that prior to the enzyme entrapment. This work opens up a new approach converting carbon dioxide to biocarbonate in a biomimetic nanoconfiguration that can be integrated with the other part of biosynthesis process for the assimilation of carbon dioxide.

Yu, Yuehua; Chen, Baowei; Qi, Wen N.; Li, Xiaolin; Shin, Yongsoon; Lei, Chenghong; Liu, Jun

2012-05-01

455

Angiopoietin-1, Angiopoietin-2 and Bicarbonate as Diagnostic Biomarkers in Children with Severe Sepsis  

PubMed Central

Severe pediatric sepsis continues to be associated with high mortality rates in children. Thus, an important area of biomedical research is to identify biomarkers that can classify sepsis severity and outcomes. The complex and heterogeneous nature of sepsis makes the prospect of the classification of sepsis severity using a single biomarker less likely. Instead, we employ machine learning techniques to validate the use of a multiple biomarkers scoring system to determine the severity of sepsis in critically ill children. The study was based on clinical data and plasma samples provided by a tertiary care center's Pediatric Intensive Care Unit (PICU) from a group of 45 patients with varying sepsis severity at the time of admission. Canonical Correlation Analysis with the Forward Selection and Random Forests methods identified a particular set of biomarkers that included Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), and Bicarbonate (HCO) as having the strongest correlations with sepsis severity. The robustness and effectiveness of these biomarkers for classifying sepsis severity were validated by constructing a linear Support Vector Machine diagnostic classifier. We also show that the concentrations of Ang-1, Ang-2, and HCO enable predictions of the time dependence of sepsis severity in children. PMID:25255212

Wang, Kun; Bhandari, Vineet; Giuliano, John S.; O?Hern, Corey S.; Shattuck, Mark D.; Kirby, Michael

2014-01-01

456

Effects of a chewable sodium bicarbonate oral composition on plaque and gingivitis.  

PubMed

The purpose of this pilot study was to evaluate the effects of an effervescent sodium bicarbonate based oral composition on plaque and gingivitis. Subjects selected for this study presented at screening with moderate plaque and American Academy of Periodontology (AAP) Type I/II periodontal status. At baseline, subjects were allocated to one of two groups by simple randomization; placebo (n=16) and active (n=16). During the study two subjects withdrew due to non-compliance and one because of a death in the family. Data were collected at baseline, day 14, and day 28. The Plaque Index (PI) of Silness and Loe was used to quantify the amount of supragingival plaque surrounding six selected teeth (3,14,8,19,24,30), and the Gingival Index (GI) of Loe and Silness was used to assess bleeding tendencies and visual appearance on the same six teeth. A soft tissue oral assessment was completed at each visit. Subjects were asked to perform study treatment three times a day, after meals, and continue with normal oral hygiene procedures. Subjects were requested to complete a 28-day diary to assess compliance. Data were analyzed using repeated measures analysis of variance. There were no statistically significant differences between the placebo and the active product groups and no statistical significant interaction between product and location within the mouth or visit for either the plaque or gingival scores. Results reveal the product was safe to oral tissues and was well accepted by subjects. PMID:12167942

McCombs, G B; Green, M L; Root, J

2001-02-15

457

Investigation of sodium carbonate, sodium bicarbonate and water systems for saturated solar ponds. Final report  

SciTech Connect

The overall objective of this study was to gather relevant data primarily from the published literature to investigate the technical feasibility of using a Na/sub 2/CO/sub 3/-NaHCO/sub 3/ mixture for a saturated solar pond. This objective was accomplished by a literature search and review of existing chemical information and by performing simple chemistry experiments in the laboratory. Information on density, solubility, phase diagram, equilibrium compositions, reaction rate constant, equilibrium constant, diffusion coefficient, vapor pressure and potentially useful additives is compiled. It is concluded that even though both the saturation density and solubility increase with temperature for trona, it is not chemically stable either at room temperature or higher temperatures (80/sup 0/C). Therefore, as is, trona is not suitable for use in a saturated solar pond. From the literature it has been found that sugar and gum can retard the decomposition of bicarbonate to carbonate in the mixture. Nevertheless, trona is a very attractive solute for an unsaturated solar pond. A laboratory unsaturated pond with a stable density gradient has worked without any problems for about two months at InterTechnology/Solar Corporation.

None

1980-03-28

458

In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate.  

PubMed

Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO(3) rise to more than 1500?mg/L (also expressed as >1245?mg HCO(3) (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800?m to 1200?m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed. PMID:24909548

Farag, Aïda M; Harper, David D; Skaar, Don

2014-09-01

459

Isolation and Bicarbonate Transport of Chloroplast Envelope Membranes from Species of Differing Net Photosynthetic Efficiency  

PubMed Central

A three-phase discontinuous sucrose gradient yielded two fractions of chloroplast envelope membranes from spinach (Spinacia oleracea L.), sunflower (Helianthus annuus L.), and maize (Zea mays L., mesophyll and undifferentiated chloroplasts). These species were selected to represent plants with fast photorespiration and slow net photosynthesis, fast photorespiration yet fast net photosynthesis, and slow photorespiration and fast net photosynthesis, respectively. Buoyant densities were 1.08 and 1.11 g cm-3. The light fraction contained primarily single (incomplete) membrane vesicles and the heavy fraction double (complete) ones. Enzymic, chemical, and electron microscopic examination of the complete envelope membranes showed a lack of microbial, microsomal, mitochondrial, and lamellar membrane contamination as well as stromal contamination. Envelope membranes for all species examined were found to contain 2 to 4% of the total chloroplast protein and yields of about 0.2 to 0.4 mg of protein were obtained from 40 g leaves. An Mg2+-dependent nonlatent ATPase, a marker enzyme for chloroplast envelope membranes, had the following activities (?moles of phosphate released/hr-1 mg protein-1): spinach, 77; sunflower, 163; old maize, 126; and young maize, 87. Bicarbonate transport was directly correlated with levels of ATPase activity in spinach and sunflower envelope membranes. Transport of HCO3? with sunflower envelope membranes approached that of young maize. Images PMID:16659477

Poincelot, Raymond P.; Day, Peter R.

1976-01-01

460

Decarboxylation without CO2: Why Bicarbonate Forms Directly as Trichloroacetate Is Converted to Chloroform.  

PubMed

Patterns in the observed catalysis of decarboxylation reactions required us to conclude that these reactions involve initial hydration of the carboxylate and subsequent loss of bicarbonate. This raises the important and general question of why CO2 is not formed directly. Reaction profiles for the direct decarboxylation of trichloroacetate were generated with DFT calculations and show no significant barrier to the recombination of the incipient trichloromethide and CO2. In contrast, cleavage of the C-C bond from the hydrated intermediate shows a substantial barrier to recombination that allows separation of the products. The free energy of the transition state for C-C bond cleavage following hydration is higher than the free energy for formation of the hydrate and is comparable to the free energy of activation for direct decarboxylation. Thus, we conclude that the advantage of the hydrolytic pathway is that it provides a means to overcome the problems of separation and solvation that hinder the direct loss of CO2. The resulting concepts are readily extended to explicating the mechanisms of processes in enzymic catalysis as well as providing a basis for producing C-C bonds by the addition of derivatives of carbanions to carbonates. PMID:25340631

Howe, Graeme W; Kluger, Ronald

2014-11-21

461

Normal mouse intestinal mucus release requires cystic fibrosis transmembrane regulator-dependent bicarbonate secretion  

PubMed Central

The mechanisms underlying mucus-associated pathologies in cystic fibrosis (CF) remain obscure. However, recent studies indicate that CF transmembrane conductance regulator (CFTR) is required for bicarbonate (HCO3–) transport and that HCO3– is critical for normal mucus formation. We therefore investigated the role of HCO3– in mucus secretion using mouse small intestine segments ex vivo. Basal rates of mucus release in the presence or absence of HCO3– were similar. However, in the absence of HCO3–, mucus release stimulated by either PGE2 or 5-hydroxytryptamine (5-HT) was approximately half that stimulated by these molecules in the presence of HCO3–. Inhibition of HCO3– and fluid transport markedly reduced stimulated mucus release. However, neither absence of HCO3– nor inhibition of HCO3– transport affected fluid secretion rates, indicating that the effect of HCO3– removal on mucus release was not due to decreased fluid secretion. In a mouse model of CF (mice homozygous for the most common human CFTR mutation), intestinal mucus release was minimal when stimulated with either PGE2 or 5-HT in the presence or absence of HCO3–. These data suggest that normal mucus release requires concurrent HCO3– secretion and that the characteristically aggregated mucus observed in mucin-secreting organs in individuals with CF may be a consequence of defective HCO3– transport. PMID:19726884

Garcia, Mary Abigail S.; Yang, Ning; Quinton, Paul M.

2009-01-01

462

The effects of sodium bicarbonate (NaHCO3) ingestion on high intensity cycling capacity.  

PubMed

Ten healthy, non-cycling trained males (age: 21.2 ± 2.2 years, body mass: 75.9 ± 13.4 kg, height: 178 ± 6 cm, [Vdot]O2PEAK: 46 ± 10 ml · kg(-1) · min(-1)) performed a graded incremental exercise test, two familiarisation trials and six experimental trials. Experimental trials consisted of cycling to volitional exhaustion at 100%, 110% and 120% WPEAK, 60 min after ingesting either 0.3 g · kg(-1) body mass sodium bicarbonate (NaHCO3) or 0.1 g · kg(-1) body mass sodium chloride (placebo). NaHCO3 ingestion increased cycling capacity by 17% at 100% WPEAK (327 vs. 383 s; P = 0.02) although not at 110% WPEAK (249 vs. 254 s; P = 0.66) or 120% WPEAK (170 vs. 175 s; P = 0.60; placebo and NaHCO3 respectively). Heart rate (P = 0.02), blood lactate (P = 0.001), pH (P < 0.001), [HCO3 (-)], (P < 0.001), and base excess (P < 0.001) were greater in all NaHCO3 trials. NaHCO3 attenuated localised ratings of perceived exertion (RPEL) to a greater extent than placebo only at 100% WPEAK (P < 0.02). Ratings of abdominal discomfort and gut fullness were mild but higher for NaHCO3. NaHCO3 ingestion significantly improves continuous constant load cycling at 100% WPEAK due to, in part, attenuation of RPEL. PMID:23323673

Higgins, Matthew F; James, Rob S; Price, Mike J

2013-01-01

463

Putative interaction of brush cells with bicarbonate secreting cells in the proximal corpus mucosa  

PubMed Central

The gastric epithelium is protected from the highly acidic luminal content by alkaline mucus which is secreted from specialized epithelial cells. In the stomach of mice strong secretion of alkaline fluid was observed at the “gastric groove,” the border between corpus and fundus mucosa. Since this region is characterized by numerous brush cells it was proposed that these cells might secrete alkaline solution as suggested for brush cells in the bile duct. In fact, it was found that in this region multiple cells express elements which are relevant for the secretion of bicarbonate, including carbonic anhydrase (CAII), the cystic fibrosis transmembrane conductance regulator (CFTR) and the Na+/H+ exchanger (NHE1). However, this cell population was distinct from brush cells which express the TRP-channel TRPM5 and are considered as putative sensory cells. The location of both cell populations in close proximity implies the possibility for a paracrine interaction. This view was substantiated by the finding that brush cells express prostaglandin synthase-1 (COX-1) and the neighboring cells a specific receptor type for prostaglandins. The notion that brush cells may be able to sense a local acidification was supported by the observation that they express the channel PKD1L3 which contributes to the acid responsiveness of gustatory sensory cells. The results support the concept that brush cells may sense the luminal content and influence via prostaglandins the secretion of alkaline solution. PMID:23874305

Eberle, Julia Anna-Maria; Muller-Roth, Kai L.; Widmayer, Patricia; Chubanov, Vladimir; Gudermann, Thomas; Breer, Heinz

2013-01-01

464

Impaired mucin synthesis and bicarbonate secretion in the colon of NHE8 knockout mice.  

PubMed

Sodium/hydrogen exchanger 8 (NHE8), the newest member of the SLC9 family, is expressed at the apical membrane of the epithelial cells in the intestine and the kidney. Although NHE8 has been shown to be an important player for intestinal sodium absorption early in development, its physiological role in the intestine remains unclear. Here, we successfully created a NHE8 knockout (NHE8(-/-)) mouse model to study the function of this transporter in the intestinal tract. Embryonic stem cells containing interrupted NHE8 gene were injected into mouse blastocyst to produce NHE8(+/-) chimeras. NHE8(-/-) mice showed no lethality during embryonic and fetal development. These mice had normal serum sodium levels and no signs of diarrhea. Apically expressed NHE2 and NHE3 were increased in the small intestine of the NHE8(-/-) mice in compensation. The number of goblet cells and mucin (MUC)-positive cells in the colon was reduced in NHE8(-/-) mice along with mucosal pH, MUC2 expression as well as downregulated in adenoma (DRA) expression. Therefore, the role of NHE8 in the intestine involves both sodium absorption and bicarbonate secretion. PMID:22575219

Xu, Hua; Zhang, Bo; Li, Jing; Wang, Chunhui; Chen, Huacong; Ghishan, Fayez K

2012-08-01

465

Buffers in daphnid culture and bioassay  

SciTech Connect

When an algal diet is employed, or precipitation of dissolved inorganics during autoclaving is likely, or test circumstances introduce pH changes, addition of a buffer to daphnid culture or bioassay media is appropriate. Glycylglycine, employed in this research for 20 years, is unsuitable for general use because it required microbe-free cultures. In contrast, n-hydroxyethyl piperazine-n-2-propane sulfonic acid (HEPPSO) and N-2-hydroxyethyl piperazine-N{prime}-2-ethane sulfonic acid (HEPES) offer safe and effective pH control at 300 ppm for animals, 400 ppm for algae (weight excludes Na), with no requirement for microbe-free cultures. No negative effects on fecundity, monitored in both single and multigeneration tests, or on vigor, measured by acute bioassay performance, were observed. The 48-h LC50 for glycylglycine is approximately 4,500 ppm. No deaths occur at or below 10,000 ppm of either HEPES or HEPPSO. When bioassayed against zinc (as chloride), animals reared in cultures buffered by HEPES, HEPPSO, or glycylglycine and tested in unfed acute bioassays performed similarly, allowing 100% survival in 1,000 ppb in 48 h with an CL50 of approximately 1,750 ppb.

Keating, K.I.; Caffrey, P.B.; Dagbusan, B.C. [Rutgers-the State Univ., New Brunswick, NJ (United States). Dept. of Environmental Science

1996-03-01

466

Conversion of sugarcane bagasse to carboxylic acids under thermophilic conditions  

E-print Network

batch hot-lime-water-treated bagasse/chicken manure fermentations with calcium carbonate???.. 217 8-32 The CPDM ?map? for 80 wt% hot-lime-water-treated bagasse/20 wt% chicken manure countercurrent fermentation with calcium carbonate buffer (124 g VS/L...-lime-water-treated bagasse/chicken manure fermentations with ammonium bicarbonate.... 225 8-39 The CPDM ?map? for 80 wt% hot-lime-water-treated bagasse/20 wt% chicken manure countercurrent fermentation with ammonium bicarbonate buffer (130 g VS/L liquid...

Fu, Zhihong

2009-05-15

467

Preferential leaching of cobalt, nickel and copper from cobalt-rich ferromanganese crusts with ammoniacal solutions using ammonium thiosulfate and ammonium sulfite as reducing agents  

Microsoft Academic Search

Preferential ammoniacal leaching of Co, Ni and Cu from cobalt-rich ferromanganese crusts under reducing conditions was performed using ammonium thiosulfate and ammonium sulfite as reducing agents. The effects of reducing agent concentration, initial pH, leaching time, temperature and the combined concentration of ammonium thiosulfate and ammonium sulfite on the extraction of Mn, Fe, Co, Ni and Cu were investigated.The extraction

M. Niinae; N. Komatsu; Y. Nakahiro; T. Wakamatsu; J. Shibata

1996-01-01

468

Effects of bicarbonate alkalinity and calcium on the acute toxicity of copper to juvenile channel catfish (Ictalurus punctatus)  

Microsoft Academic Search

Abstract Three experiments ,were conducted ,to evaluate ,the relative importance ,of calcium ,hardness and bicarbonate alkalinity to the acute response of juvenile channel catfish (Ictalurus punctatus) exposed to a toxic concentration of copper sulfate. A preliminary bioassay ,revealed 28 mg·l, CaC03, copper related catfish mortalities displayed high variability and means ranged,from 6.7 to 60%. Mortalities decreased ,as calcium, concentrations ,increased.

William A. Wurts; Peter W. Perschbacher

1994-01-01

469