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Sample records for bestrophin-2 mediates bicarbonate

  1. Lineage-specific expression of bestrophin-2 and bestrophin-4 in human intestinal epithelial cells

    DEFF Research Database (Denmark)

    Ito, Go; Okamoto, Ryuichi; Murano, Tatsuro

    2013-01-01

    Intestinal epithelial cells (IECs) regulate the absorption and secretion of anions, such as HCO3(-) or Cl(-). Bestrophin genes represent a newly identified group of calcium-activated Cl(-) channels (CaCCs). Studies have suggested that, among the four human bestrophin-family genes, bestrophin-2...... (BEST2) and bestrophin-4 (BEST4) might be expressed within the intestinal tissue. Consistently, a study showed that BEST2 is expressed by human colonic goblet cells. However, their precise expression pattern along the gastrointestinal tract, or the lineage specificity of the cells expressing these genes...

  2. Lineage-specific expression of bestrophin-2 and bestrophin-4 in human intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Go Ito

    Full Text Available Intestinal epithelial cells (IECs regulate the absorption and secretion of anions, such as HCO3(- or Cl(-. Bestrophin genes represent a newly identified group of calcium-activated Cl(- channels (CaCCs. Studies have suggested that, among the four human bestrophin-family genes, bestrophin-2 (BEST2 and bestrophin-4 (BEST4 might be expressed within the intestinal tissue. Consistently, a study showed that BEST2 is expressed by human colonic goblet cells. However, their precise expression pattern along the gastrointestinal tract, or the lineage specificity of the cells expressing these genes, remains largely unknown. Here, we show that BEST2 and BEST4 are expressed in vivo, each in a distinct, lineage-specific manner, in human IECs. While BEST2 was expressed exclusively in colonic goblet cells, BEST4 was expressed in the absorptive cells of both the small intestine and the colon. In addition, we found that BEST2 expression is significantly down-regulated in the active lesions of ulcerative colitis, where goblet cells were depleted, suggesting that BEST2 expression is restricted to goblet cells under both normal and pathologic conditions. Consistently, the induction of goblet cell differentiation by a Notch inhibitor, LY411575, significantly up-regulated the expression of not BEST4 but BEST2 in MUC2-positive HT-29 cells. Conversely, the induction of absorptive cell differentiation up-regulated the expression of BEST4 in villin-positive Caco-2 cells. In addition, we found that the up- or down-regulation of Notch activity leads to the preferential expression of either BEST4 or BEST2, respectively, in LS174T cells. These results collectively confirmed that BEST2 and BEST4 could be added to the lineage-specific genes of humans IECs due to their abilities to clearly identify goblet cells of colonic origin and a distinct subset of absorptive cells, respectively.

  3. Dynamic volume changes in astrocytes are an intrinsic phenomenon mediated by bicarbonate ion flux.

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    Clare M Florence

    Full Text Available 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 (HCO(3- ions as swelling was significantly decreased when the influx of HCO(3- was reduced. We found: 1 in HCO(3- 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 HCO(3- efflux is known to occur through the γ-amino-butyric acid (GABA channel, we performed a series of experiments to determine if astrocytes were capable of HCO(3- mediated volume shrinkage with GABA channel activation. Astrocytes were found to shrink -7.7±0.5% of control in response to the GABA(A channel agonist muscimol. Astrocyte shrinkage from GABA(A 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.

  4. A host defense mechanism involving CFTR-mediated bicarbonate secretion in bacterial prostatitis.

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    Chen Xie

    Full Text Available BACKGROUND: Prostatitis is associated with a characteristic increase in prostatic fluid pH; however, the underlying mechanism and its physiological significance have not been elucidated. METHODOLOGY/PRINCIPAL FINDINGS: In this study a primary culture of rat prostatic epithelial cells and a rat prostatitis model were used. Here we reported the involvement of CFTR, a cAMP-activated anion channel conducting both Cl(- and HCO(3(-, in mediating prostate HCO(3(- secretion and its possible role in bacterial killing. Upon Escherichia coli (E. coli-LPS challenge, the expression of CFTR and carbonic anhydrase II (CA II, along with several pro-inflammatory cytokines was up-regulated in the primary culture of rat prostate epithelial cells. Inhibiting CFTR function in vitro or in vivo resulted in reduced bacterial killing by prostate epithelial cells or the prostate. High HCO(3(- content (>50 mM, rather than alkaline pH, was found to be responsible for bacterial killing. The direct action of HCO(3(- on bacterial killing was confirmed by its ability to increase cAMP production and suppress bacterial initiation factors in E. coli. The relevance of the CFTR-mediated HCO(3(- secretion in humans was demonstrated by the upregulated expression of CFTR and CAII in human prostatitis tissues. CONCLUSIONS/SIGNIFICANCE: The CFTR and its mediated HCO(3(- secretion may be up-regulated in prostatitis as a host defense mechanism.

  5. Bicarbonate Test

    Science.gov (United States)

    ... bicarbonate in the blood). They also help monitor treatment until acid-base balance is restored. ^ Back to top When is it ... basic metabolic panels are commonly used to monitor treatment of certain problems, including ... maintaining its acid-base balance , either by failing to remove carbon dioxide through ...

  6. CFTR mediates bicarbonate-dependent activation of miR-125b in preimplantation embryo development

    Institute of Scientific and Technical Information of China (English)

    Yong Chao Lu; Alvin Chun Hang Ma; Anskar Yu Hung Leung; He Feng Huang; Hsiao Chang Chan; Hui Chen; Kin Lam Fok; Lai Ling Tsang; Mei Kuen Yu; Xiao Hu Zhang; Jing Chen; Xiaohua Jiang; Yiu Wa Chung

    2012-01-01

    Although HCO3-is known to be required for early embryo development,its exact role remains elusive.Here we report that HCO3-acts as an environmental cue in regulating miR-125b expression through CFTR-mediated influx during preimplantation embryo development.The results show that the effect of HCO3-on preimplantation embryo development can be suppressed by interfering the function of a HCO3--conducting channel,CFTR,by a specific inhibitor or gene knockout.Removal of extracellular HCO3-or inhibition of CFTR reduces miR-125b expression in 2 cell-stage mouse embryos.Knockdown of miR-125b mimics the effect of HCO3-removal and CFTR inhibition,while injection of miR-125b precursor reverses it.Downregulation of miR-125b upregulates p53 cascade in both human and mouse embryos.The activation of miR-125b is shown to be mediated by sAC/PKA-dependent nuclear shuttling of NF-KB.These results have revealed a critical role of CFTR in signal transduction linking the environmental HCO3-to activation of miR-125b during preimplantation embryo development and indicated the importance of ion channels in regulation of miRNAs.

  7. Effects of sodium bicarbonate and ammonium chloride pre-treatments on PEPT2 (SLC15A2) mediated renal clearance of cephalexin in healthy subjects.

    Science.gov (United States)

    Liu, Rui; Tang, Audrey May Yi; Tan, Yen Ling; Limenta, Lie Michael George; Lee, Edmund Jon Deoon

    2011-01-01

    PEPT2 mediates the H(+) gradient-driving reabsorption of di- and tri-peptides, and various peptidomimetic compounds in the kidney. This study examines the influence of urinary pH modification through sodium bicarbonate and ammonium chloride pre-treatments on the function of PEPT2 in healthy subjects, using cephalexin as the probe drug. Sixteen male subjects received a single oral dose of 1000 mg cephalexin under ammonium chloride and sodium bicarbonate treatment, respectively, with a wash-out period of one week. The study subjects were genotyped for PEPT2 polymorphic variants. Cephalexin concentrations in plasma and urine were determined by high performance liquid chromatography. The mean renal clearance of cephalexin was significantly higher under ammonium chloride treatment than that under sodium bicarbonate treatment (P < 0.01). This difference was significant for PEPT2*2/*2 (P = 0.017) but not for PEPT2*1/*1 (P = 0.128). No differences were observed for other pharmacokinetic parameters. The findings of this study suggest that urinary pH changes may alter the pharmacokinetics of PEPT2's substrates. This effect was more obvious for the PEPT2*2/*2.

  8. Regulation of anterior chamber drainage by bicarbonate-sensitive soluble adenylyl cyclase in the ciliary body.

    Science.gov (United States)

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

    2011-12-02

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

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

    Science.gov (United States)

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

    2011-01-01

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

  10. Cholangiocyte anion exchange and biliary bicarbonate excretion

    Institute of Scientific and Technical Information of China (English)

    Jesús M Banales; Jesús Prieto; Juan F Medina

    2006-01-01

    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. Theexcretion 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.

  11. Bicarbonate kinetics in Indian males

    Indian Academy of Sciences (India)

    T Raj; R Kuriyan; A V Kurpad

    2006-06-01

    Measurement of rates of in vivo substrate oxidation such as that of glucose, fatty acids and amino acids, are based on tracer (14C or 13C) data, and often depend on the isotopic content of expired CO2. The recovery of tracer-labelled CO2 generated from the oxidation of 13C labelled substrates may not be 100% over short term. This can lead to underestimation of oxidation rate of substrates, and consequently a correction for the incomplete recovery of tracer has to be applied by the determination of the recovery of 13CO2 in the breath during tracer bicarbonate infusions. We have studied the recovery of tracer-labelled bicarbonate using a bolus administration model, and further characterized kinetics of bicarbonate using a three-compartment model, to assess which compartmental fluxes changed during the change from a fasted state to fed state. Recovery of bicarbonate was lower at 69% and 67% (fasted and fed state) than the value of 71% and 74% found during earlier longer term of continuous infusions. During feeding, there was a 20-fold increase in the flux of bicarbonate between the central compartment and the compartment that was equivalent to the viscera. This study shows that the difference between the fasted and fed state recovery of tracer bicarbonate similar to that obtained with continuous infusions, and that bicarbonate fluxes show large changes between different compartments in the body depending on metabolic state.

  12. Apparent Bicarbonate Space in Children

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    Horacio A. Repetto

    2006-01-01

    Full Text Available The amount needed to change the concentration of a solute requires the knowledge of its volume of distribution in the solution. Electrolytes that do not participate in active metabolic reactions have a fixed volume of distribution that corresponds to the volume of water in which they solubilize. Bicarbonate infusion is used to correct hyperchloremic metabolic acidosis. Its volume of distribution (bicarbonate space changes with its participation in the blood buffer systems. In other words, it is not a fixed physical volume, like that of other solutes. In this paper, we shall review experimental studies that supported evidence for this knowledge and analyze the basic hypothesis to explain the phenomena. Since we have not found clinical studies in children, we shall report our experience in a group of patients with metabolic acidosis treated with bicarbonate infusion in whom apparent bicarbonate space was measured and compared with data in adults from the literature. Guidelines for amount of bicarbonate needed to increase its concentration according to baseline bicarbonate concentration will be suggested.

  13. Involvement of CFTR in Uterine Bicarbonate Secretion and the Fertilizing Capacity of Sperm

    Institute of Scientific and Technical Information of China (English)

    WangXiao,Fei; ZhouChen-Xi; ShiQi-Xian; YuanYu-Ying; YuMei-Kuen; LouisChukwuemekaAjonuma

    2005-01-01

    Cystic fibrosis transmembrane conductance regulator (CFFR)is a cAMP-activated chloride channel expressed in a wide variety of epithelial cells,mutations of which are responsible for the hallmark defective chloride secretion observed in cystic fibrosis(CF).Although CFTR has been implicated in bicarbonate secretion,its ability to directly mediate bicarbonate secretion of any physiological significance has not been shown.We demonstrate here that endometriaI epithelial ceils possess a CFTR-mediated bicarbonate transport mechanism.Co-culture of sperm with endometrial ceils treated with antisense oligonucleotide against CFTR,or with bicarbonate secretion-defective CF epithelial cells,resulted in lower sperm capacitation and egg-fertilizing ability.These results are consistent with a critical role of CFTR in controlling uterine bicarbonate secretion and the fertilizing capacity of sperm,providing a link between defective CFTR and lower female fertility in CF.

  14. Intestinal Bicarbonate Secretion in Cystic Fibrosis Mice

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    Clarke LL

    2001-07-01

    Full Text Available Gene-targeted disruption of the cystic fibrosis transmembrane conductance regulator (CFTR in mice results in an intestinal disease phenotype that is remarkably similar to bowel disease in cystic fibrosis patients. In the intestinal segment downstream from the stomach (i.e., the duodenum, CFTR plays an important role in bicarbonate secretion that protects the epithelium from acidic gastric effluent. In this report, we examine the role of CFTR in cAMP-stimulated bicarbonate secretion in the murine duodenum and the mechanisms of acid-base transport that are revealed in CFTR knockout (CF mice. Ion substitution, channel blocker and pH stat studies comparing duodena from wild-type and CF mice indicate that CFTR mediates a HCO(3(- conductance across the apical membrane of the epithelium. In the presence of a favorable cell-to-lumen HCO(3(- gradient, the CFTR-mediated HCO(3(- current accounts for about 80% of stimulated HCO(3(- secretion. Exposure of the duodenal mucosa to acidic pH reveals another role of CFTR in facilitating HCO(3(- secretion via an electroneutral, 4,4'-diisothiocyanato-stilbene-2,2' disulfonic acid (DIDS sensitive Cl(-/HCO(3(- exchange process. In CF duodenum, other apical membrane acid-base transporters retain function, thereby affording limited control of transepithelial pH. Activity of a Cl(--dependent anion exchanger provides near-constant HCO(3(- secretion in CF intestine, but under basal conditions the magnitude of secretion is lessened by simultaneous activity of a Na(+/H(+ exchanger (NHE. During cAMP stimulation of CF duodenum, a small increase in net base secretion is measured but the change results from cAMP inhibition of NHE activity rather than increased HCO(3(- secretion. Interestingly, a small inward current that is sensitive to the anion channel blocker, 5-nitro-2(3-phenylpropyl amino-benzoate (NPPB, is also activated during cAMP stimulation of the CFTR-null intestine but the identity of the current is yet to be

  15. Critical role of bicarbonate and bicarbonate transporters in cardiac function

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

    Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H+, HCO3- is generated from CO2 and H2 O, 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 SLC4 A and SLC26 A families in heart. We also present RNA Seq analysis of their cardiac mRNA expression levels. These studies indicate that slc4a3(AE3) is the major Cl-/HCO3- exchanger and plays a protective role in heart failure, and that Slc4a4(NBCe1) is the major Na+/HCO3- cotransporter and affects action potential duration. In addition, previous studies show that HCO3- has a positive inotropic effect in the perfused heart that is largely independent of effects on intracellular Ca2+. The importance of HCO3- in the regulation of contractility is supported by experiments showing that isolated cardiomyocytes exhibit sharply enhanced contractility, with no change in Ca2+ transients, when switched from Hepes-buffered to HCO3-- buffered solutions. These studies demonstrate that HCO3- and HCO3--handling proteins play important roles in the regulation of cardiac function.

  16. Sodium-Coupled Bicarbonate Transporters

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    Boron WF

    2001-07-01

    Full Text Available Together, the Na(+-coupled HCO(3(- transporters and the AE family of anion exchangers (i.e., Cl-HCO3 exchangers comprise the bicarbonate transporter (BT superfamily. Virtually all BTs are important for the regulation of intracellular pH (pH(i in cells throughout the body. Specific BTs also play roles in cell-volume regulation, as well as for the transport of salt and/or acid-base equivalents across many epithelia. Electrogenic Na/HCO3 cotransporters (NBCe's play key roles in HCO(3(- reabsorption by the renal proximal tubule, and HCO(3(- secretion by the pancreatic duct. Electroneutral NBC's (NBCn's regulate pH(i in vascular smooth muscle and are present in/near axons in the brain. Finally, the Na(+-driven Cl-HCO3 exchanger (NDCBE's appear to be the major pH(i regulators in CNS neurons. A characteristic of most, but not all, BT's is that they are inhibited rather effectively by 4,4'-diisothiocyanostilbene-4,4'-disulfonate (DIDS.

  17. Bicarbonate is a recycling substrate for cyanase.

    Science.gov (United States)

    Johnson, W V; Anderson, P M

    1987-07-01

    Cyanase is an inducible enzyme in Escherichia coli that catalyzes bicarbonate-dependent decomposition of cyanate to ammonia and bicarbonate. Previous studies provided evidence that carbamate is an initial product and that the kinetic mechanism is rapid equilibrium random (bicarbonate serving as substrate as opposed to activator); the following mechanism was proposed (Anderson, P. M. (1980) Biochemistry 19, 2282-2888; Anderson, P. M., and Little, R. M. (1986) Biochemistry 25, 1621-1626). (formula; see text) Direct evidence for this mechanism was obtained in this study by 1) determining whether CO2 or HCO3- serves as substrate and is formed as product, 2) identifying the products formed from [14C]HCO3- and [14C] OCN-, 3) identifying the products formed from [13C] HCO3- and [12C]OCN- in the presence of [18O]H2O, and 4) determining whether 18O from [18O]HCO3- is incorporated into CO2 derived from OCN-. Bicarbonate (not CO2) is the substrate. Carbon dioxide (not HCO3-) is produced in stoichiometric amounts from both HCO3- and OCN-. 18O from [18O]H2O is not incorporated into CO2 formed from either HCO3- or OCN-. Oxygen-18 from [18O]HCO3- is incorporated into CO2 derived from OCN-. These results support the above mechanism, indicating that decomposition of cyanate catalyzed by cyanase is not a hydrolysis reaction and that bicarbonate functions as a recycling substrate.

  18. Bicarbonate-Regulated Soluble Adenylyl Cyclase

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    Wuttke MS

    2001-07-01

    Full Text Available Soluble adenylyl cyclase (sAC represents a novel form of mammalian adenylyl cyclase structurally, molecularly, and biochemically distinct from the G protein-regulated, transmembrane adenylyl cyclases (tmACs. sAC possesses no transmembrane domains and is insensitive to classic modulators of tmACs, such as heterotrimeric G proteins and P site ligands. Thus, sAC defines an independently regulated cAMP signaling system within mammalian cells. sAC is directly stimulated by bicarbonate ion both in vivo in heterologously expressing cells and in vitro using purified protein. sAC appears to be the predominant form of adenylyl cyclase (AC in mammalian sperm, and its direct activation by bicarbonate provides a mechanism for generating the cAMP required to complete the bicarbonate-induced processes necessary for fertilization, including hyperactivated motility, capacitation, and the acrosome reaction. Immunolocalization studies reveal sAC is also abundantly expressed in other tissues which respond to bicarbonate or carbon dioxide levels suggesting it may function as a general bicarbonate/CO(2 sensor throughout the body.

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

    Science.gov (United States)

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

    2009-07-01

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

  20. Pancreatic bicarbonate secretion involves two proton pumps

    DEFF Research Database (Denmark)

    Novak, Ivana; Wang, Jing; Henriksen, Katrine L.

    2011-01-01

    Pancreas secretes fluid rich in digestive enzymes and bicarbonate. The alkaline secretion is important in buffering of acid chyme entering duodenum and for activation of enzymes. This secretion is formed in pancreatic ducts, and studies to date show that plasma membranes of duct epithelium expres...

  1. Intestinal bicarbonate secretion by marine teleost fish - why and how?

    DEFF Research Database (Denmark)

    Wilson, Rod W.; Wilson, Jonathan M.; Grosell, Martin Hautopp

    2002-01-01

    Calcium, Precipitation, Osmoregulation, pH-stat titration, Water absorption, Chloride-bicarbonate exchange......Calcium, Precipitation, Osmoregulation, pH-stat titration, Water absorption, Chloride-bicarbonate exchange...

  2. Biofiltration with bicarbonate as dialysate buffer.

    Science.gov (United States)

    Rizzelli, S; Alfonso, L; Corlianò, C; Patruno, P; Sozzo, E; Mastrangelo, F

    1986-12-01

    The biofiltration with bicarbonate as dialysate buffer (BiBF) was used in 10 patients on RDT: the patients were treated for 10 months on standard BF and for 10 months on BiBF. The amount of fluid infused varied between 3 and 5 liters and Na-bicarbonate (100 mEq/h) was infused during BF. The dialytic protocol was 3 hours every other day. Cardiovascular stability, waste molecules and acid-base balance were investigated. No differences in vascular stability and no significant changes in the waste-molecules concentrations were found. Both protocols correct the metabolic acidosis; however, in standard BF 50% of patients showed acute hypocapnia at the end of dialysis.

  3. Regulators of Slc4 bicarbonate transporter activity

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    Ian M. Thornell

    2015-06-01

    Full Text Available The Slc4 family of transporters is comprised of anion exchangers (AE1-4, Na-coupled bicarbonate transporters (NCBTs including electrogenic Na/bicarbonate cotransporters (NBCe1 and NBCe2, electroneutral Na/bicarbonate cotransporters (NBCn1 and NBCn2, and the electroneutral Na-driven Cl-bicarbonate exchanger (NDCBE, as well as a borate transporter (BTR1. These transporters regulate intracellular pH (pHi and contribute to steady-state pHi, but are also involved in other physiological processes including CO2 carriage by red blood cells and solute secretion/reabsorption across epithelia. Acid-base transporters function as either acid extruders or acid loaders, with the Slc4 proteins moving HCO3– either into or out of cells. According to results from both molecular and functional studies, multiple Slc4 proteins and/or associated splice variants with similar expected effects on pHi are often found in the same tissue or cell. Such apparent redundancy is likely to be physiologically important. In addition to regulating pHi, a HCO3– transporter contributes to a cell’s ability to fine tune the intracellular regulation of the cotransported/exchanged ion(s (e.g., Na+ or Cl–. In addition, functionally similar transporters or splice variants with different regulatory profiles will optimize pH physiology and solute transport under various conditions or within subcellular domains. Such optimization will depend on activated signaling pathways and transporter expression profiles. In this review, we will summarize and discuss both classical and more recently identified regulators of the Slc4 proteins. Some of these regulators include traditional second messengers, lipids, binding proteins, autoregulatory domains, and less conventional regulators. The material presented will provide insight into the diversity and physiological significance of multiple members within the Slc4 gene family.

  4. Impaired Pancreatic Ductal Bicarbonate Secretion in Cystic Fibrosis

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    Soleimani M

    2001-07-01

    Full Text Available Patients with cystic fibrosis demonstrate a defect in HCO(3(- secretion by their pancreatic duct cells. However, attempts toward understanding or correcting this defect have been hampered by a lack of knowledge regarding the cellular and molecular mechanisms mediating HCO(3(- transport in these cells. Recent functional and molecular studies indicate a major role for a basolateral electrogenically-driven Na(+:HCO(3(- cotransporter (NBC1 in mediating the transport of HCO(3(- into the duct cells. The HCO(3(- exits at the lumen predominantly via two recently discovered apical HCO(3(- transporters. cAMP, which mediates the stimulatory effect of secretin on pancreatic ductal HCO(3(- secretion, potentiates the basolateral Na(+:HCO(3(- cotransporter due to generation of a favorable electrogenic gradient as a result of membrane depolarization by Cl(--secreting cystic fibrosis transmembrane conductance regulator (CFTR. Two apical HCO(3(- transporters drive the secretion of bicarbonate into the pancreatic duct lumen. Molecular and functional studies indicate that CFTR upregulates the expression of these two apical HCO(3(- transporters. In addition, CFTR may also upregulate the expression of certain water channels and facilitate the secretion of fluid into the duct lumen. In brief, current research suggests that the defect in pancreatic HCO(3(- secretion in patients with cystic fibrosis is multifactorial and involves the alteration in the function/expression of transporters at the basolateral and luminal membrane domains of the duct cells.

  5. Reappraisal of bicarbonate secretion by the human oesophagus

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K

    1997-01-01

    BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosal bicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophageal bicarbonate secretion...... with either 60 mg/day omeprazole for three days and 80 mg intravenous omeprazole before perfusion or 600 mg/day ranitidine for three days and 50 mg/h intravenously during the perfusion. Saliva and samples of aspirate from the perfused oesophagus and stomach were collected and bicarbonate concentrations were...... measured. RESULTS: The median rates (95% confidence intervals) of intrinsic oesophageal bicarbonate secretion, corrected for contaminating salivary and gastric bicarbonate, were 89 (33-150) and 121 (63-203) mumol/h/10 cm (p > 0.5) in omeprazole and ranitidine treated subjects respectively. Salivary...

  6. Reappraisal of bicarbonate secretion by the human oesophagus.

    OpenAIRE

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, K; Rask-Madsen, J

    1997-01-01

    BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosal bicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophageal bicarbonate secretion and thus contribute to the therapeutic efficacy of the drug in gastro-oesophageal reflux disease. SUBJECTS AND METHODS: In nine healthy volunteers, oesophageal "steady state" perfusion of a 10 cm open segm...

  7. Gram-scale solution-phase synthesis of selective sodium bicarbonate Co-transport Inhibitor S0859

    DEFF Research Database (Denmark)

    Larsen, Ann Møller; Krogsgaard-Larsen, Niels; Lauritzen, Gitte

    2012-01-01

    Na+-coupled HCO3- transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast...

  8. Peptic ulcer pathophysiology: acid, bicarbonate, and mucosal function

    DEFF Research Database (Denmark)

    Højgaard, L; Mertz Nielsen, A; Rune, S J

    1996-01-01

    . Bicarbonate secretion is inhibited by atropine, muscarinic antagonists, alpha-adrenoceptor agonists, indomethacin, bile acids, tobacco smoking, and probably also by infection by Helicobacter pylori. Apart from mucus and bicarbonate, the mucosal defence is supported by a hydrophobic epithelial lining, rapid...

  9. Sodium bicarbonate therapy in patients with metabolic acidosis.

    Science.gov (United States)

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

    2014-01-01

    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.

  10. Reappraisal of bicarbonate secretion by the human oesophagus

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, Klaus

    1997-01-01

    BACKGROUND AND AIMS: Administration of omeprazole to healthy volunteers was recently reported to increase proximal duodenal mucosalbicarbonate secretion. As human oesophagus also secretes bicarbonate, the hypothesis was tested that omeprazole may stimulate oesophagealbicarbonate secretion and thus....../day omeprazole for three days and 80 mg intravenous omeprazole before perfusionor 600 mg/day ranitidine for three days and 50 mg/h intravenously during the perfusion. Saliva and samples of aspirate from the perfusedoesophagus and stomach were collected and bicarbonate concentrations were measured. RESULTS......: The median rates (95% confidence intervals)of intrinsic oesophageal bicarbonate secretion, corrected for contaminating salivary and gastric bicarbonate, were 89 (33-150) and 121 (63-203)mumol/h/10 cm (p > 0.5) in omeprazole and ranitidine treated subjects respectively. Salivary and gastric bicarbonate...

  11. Sodium bicarbonate ingestion and boxing performance.

    Science.gov (United States)

    Siegler, Jason C; Hirscher, Kristian

    2010-01-01

    Boxing is a sport that consists of multiple high-intensity bouts separated by minimal recovery time and may benefit from a pre-exercise alkalotic state. The purpose of this study was to observe the ergogenic potential of sodium bicarbonate (NaHCO3) ingestion on boxing performance. Ten amateur boxers volunteered to participate in 2 competitive sparring bouts. The boxers were prematched for weight and boxing ability and consumed either 0.3 g.kg(-1) body weight (BW) of NaHCO3 (BICARB) or 0.045 g.kg(-1) BW of NaCl placebo (PLAC) mixed in diluted low calorie-flavored cordial. The sparring bouts consisted of four 3-minute rounds, each separated by 1-minute seated recovery. Blood acid-base (pH, bicarbonate [HCO3(-)], base excess [BE]), and performance (rates of perceived exertion [RPE], heart rate [HR] [HR(ave) and HR(max)], total punches landed successfully) profiles were analyzed before (where applicable) and after sparring. The results indicated a significant interaction effect for HCO3(-) (p < or = 0.001) and BE (p < 0.001), but not for pH (p = 0.48). Post hoc analysis revealed higher presparring HCO3(-) and BE for the BICARB condition, but no differences between the BICARB and PLAC conditions postsparring. There was a significant increase in punches landed during the BICARB condition (p < 0.001); however, no significant interaction effects for HRave (p = 0.15), HRmax (p = 0.32), or RPE (p = 0.38). The metabolic alkalosis induced by the NaHCO3 loading elevated before and after sparring blood buffering capacity. In practical application, the findings suggest that a standard NaHCO3 loading dose (0.3 g.kg(-1)) improves punch efficacy during 4 rounds of sparring performance.

  12. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans.

    Science.gov (United States)

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, K; Rask-Madsen, J

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n = 17) and after pretreatment with high dose omeprazole (n = 17) and ranitidine (n = 9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid secretion (pH 6.9 v 6.8; p > 0.05). Omeprazole caused higher rates of basal (mean (SEM)) (597 (48) v 351 (39) mumol/h; p 0.05) duodenal bicarbonate secretion compared with control experiments. Also the combination of omeprazole and ranitidine increased (p = 0.05) duodenal bicarbonate secretion, while ranitidine alone caused no change in either basal or stimulated secretion. In the stomach basal as well as vagally stimulated bicarbonate secretion was independent of the means of acid inhibition. These results show that the proton pump inhibitor, omeprazole, promotes proximal duodenal mucosal bicarbonate secretion apparently independent of its gastric acid inhibitory effect. The mechanism of action remains speculative.

  13. Bicarbonate is a recycling substrate for cyanase

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, W.V.; Anderson, P.M.

    1987-05-01

    Cyanase catalyzes HCO/sub 3//sup -/-dependent decomposition of cyanate to NH/sub 4//sup +/ and HCO/sub 3//sup -/. Previous studies provided evidence that carbamate is an initial product and that the kinetic mechanism is rapid equilibrium random (HCO/sub 3//sup -/ serving as substrate as opposed to activator). Direct evidence for this mechanism was obtained in this study by (1) identifying the products formed from (/sup 14/C)HCO/sub 3//sup -/ or (/sup 14/C)OCN/sup -/, (2) identifying the products formed from (/sup 13/C)HCO/sub 3//sup -/ in the presence of (/sup 18/O)H/sub 2/O, and (3) determining whether CO/sub 2/ or HCO/sub 3//sup -/ serve as substrate and are formed as product. Carbon dioxide (not HCO/sub 3//sup -/) is produced in stoichiometric amounts from both HCO/sub 3//sup -/ and OCN/sup -/. Bicarbonate (not CO/sub 2/) is the substrate. Oxygen-18 from (/sup 18/O)H/sub 2/O is not incorporated into CO/sub 2/ formed from either HCO/sub 3//sup -/ or OCN/sup -/. These results indicate that decomposition of cyanate is not a hydrolysis reaction and that HCO/sub 3//sup -/ functions as a substrate.

  14. BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL PAINTING

    Science.gov (United States)

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

  15. Combined creatine and sodium bicarbonate supplementation enhances interval swimming.

    Science.gov (United States)

    Mero, Antti A; Keskinen, Kari L; Malvela, Marko T; Sallinen, Janne M

    2004-05-01

    This study examined the effect of simultaneous supplementation of creatine and sodium bicarbonate on consecutive maximal swims. Sixteen competitive male and female swimmers completed, in a randomized order, 2 different treatments (placebo and a combination of creatine and sodium bicarbonate) with 30 days of washout period between treatments in a double-blind crossover procedure. Both treatments consisted of placebo or creatine supplementation (20 g per day) in 6 days. In the morning of the seventh day, there was placebo or sodium bicarbonate supplementation (0.3 g per kg body weight) during 2 hours before a warm-up for 2 maximal 100-m freestyle swims that were performed with a passive recovery of 10 minutes in between. The first swims were similar, but the increase in time of the second versus the first 100-m swimming time was 0.9 seconds less (p creatine and sodium bicarbonate enhances performance in consecutive maximal swims.

  16. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans.

    OpenAIRE

    Mertz-Nielsen, A; Hillingsø, J; Bukhave, K; Rask-Madsen, J

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate...

  17. MICROWAVE-ASSISTED SURFACE MODIFICATION OF CALCIUM BICARBONATE

    Institute of Scientific and Technical Information of China (English)

    Jing Ye; Xiaofei Zhang

    2004-01-01

    Surface modification of calcium bicarbonate powder with isopropyl triisostearoyl titanate (TTS) by microwave-assisted heating was studied in the present work. The features of microwave treated powder show obvious superiority to those of powder samples treated by traditional surface modification method and of untreated calcium bicarbonate - in suspension turbidity, suction potential, contact angle with water, and mechanical properties of their composites with PVC resin.

  18. Carbonate and Bicarbonate Ion Transport in Alkaline Anion Exchange Membranes

    Science.gov (United States)

    2013-06-25

    Bicarbonate Ion Transport in Alk Block 13: Supplementary Note © 2013 . Published in Journal of the Electrochemical Society , Vol. Ed. 0 160, (9) (2013...for public release; distribution is unlimited. ... 60325.7-CH-II F994 Journal of The Electrochemical Society , 160 (9) F994-F999 (2013) 0013-4651/2013...160(9)/F994/6/$31.00 © The Electrochemical Society Carbonate and Bicarbonate Ion Transport in Alkaline Anion Exchange Membranes Andrew M. Kiss,a

  19. Practical considerations for bicarbonate loading and sports performance.

    Science.gov (United States)

    Burke, Louise M

    2013-01-01

    Consumption of sodium bicarbonate (300 mg/kg 1-2 h before exercise) can temporarily increase blood bicarbonate concentrations, enhancing extracellular buffering of hydrogen ions which accumulate and efflux from the working muscle. Such 'bicarbonate loading' provides an ergogenic strategy for sporting events involving high rates of anaerobic glycolysis which are otherwise limited by the body's capacity to manage the progressive increase in intracellular acidity. Studies show that bicarbonate loading strategies have a moderate positive effect on the performance of sports involving 1-7 min of sustained strenuous exercise, and may also be useful for prolonged sports involving intermittent or sustained periods of high-intensity work rates. This potential to enhance sports performance requires further investigation using appropriate research design, but may be limited by practical considerations such as gut discomfort or the logistics of the event. The effect of chronic use of bicarbonate supplementation prior to high-intensity workouts to promote better training performance and adaptations is worthy of further investigation. While this relatively simple dietary strategy has been studied and used by sports people for over 80 years, it is likely that there are still ways in which further benefits from bicarbonate supplementation can be developed and individualized for specific athletes or specific events.

  20. Sodium bicarbonated mineral water decreases postprandial lipaemia in postmenopausal women compared to a low mineral water

    OpenAIRE

    S. Schoppen; Pérez Granados, Ana M.; Carbajal, A.; Sarriá, Beatriz; Sánchez-Muniz, F. J.; J. A. Gómez-Gerique; Vaquero, M. Pilar

    2005-01-01

    The role of bicarbonated mineral waters on lipid metabolism and lipoprotein concentrations in man has scarcely been investigated. The present study aimed to investigate whether drinking sodium bicarbonated mineral water affects postprandial cholesterol and triacylglycerol metabolism in postmenopausal women. In a three-way, randomised, crossover study, eighteen healthy postmenopausal women consumed two sodium bicarbonated mineral waters (bicarbonated mineral water 1 and bicarbonated mineral wa...

  1. Intestinal GPS: bile and bicarbonate control cyclic di-GMP to provide Vibrio cholerae spatial cues within the small intestine

    OpenAIRE

    Koestler, Benjamin J.; Waters, Christopher M.

    2015-01-01

    The second messenger cyclic di-GMP (c-di-GMP) regulates numerous phenotypes in response to environmental stimuli to enable bacteria to transition between different lifestyles. Here we discuss our recent findings that the human pathogen Vibrio cholerae recognizes 2 host-specific signals, bile and bicarbonate, to regulate intracellular c-di-GMP. We have demonstrated that bile acids increase intracellular c-di-GMP to promote biofilm formation. We have also shown that this bile-mediated increase ...

  2. Role of calcium signaling in epithelial bicarbonate secretion.

    Science.gov (United States)

    Jung, Jinsei; Lee, Min Goo

    2014-06-01

    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.

  3. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans

    DEFF Research Database (Denmark)

    Mertz-Nielsen, Anette; Hillingsø, J; Bukhave, Klaus

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H-2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether...... this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n=17) and after pretreatment with high...... dose omeprazole (n=17) and ranitidine (n=9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid secretion (p...

  4. Omeprazole promotes proximal duodenal mucosal bicarbonate secretion in humans

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, Jens; Bukhave, K

    1996-01-01

    The proton pump inhibitor, omeprazole, surprisingly resulted in higher rates of proximal duodenal mucosal bicarbonate secretion than previously reported using an H2 receptor antagonist for gastric acid inhibition. Gastroduodenal perfusions were performed in healthy volunteers to evaluate whether...... this incidental finding is explained by more potent gastric acid inhibition by omeprazole or might be caused by the different mode of drug action. Basal and stimulated gastric and duodenal bicarbonate secretion rates were measured in the same subjects in control experiments (n = 17) and after pretreatment...... with high dose omeprazole (n = 17) and ranitidine (n = 9), respectively, by use of a technique permitting simultaneous measurements. Concentrations of bicarbonate were measured in the respective effluents by the method of back titration. Both omeprazole and ranitidine completely inhibited gastric acid...

  5. Bicarbonate produced from carbon capture for algae culture.

    Science.gov (United States)

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

    2011-11-01

    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.

  6. Intestinal GPS: bile and bicarbonate control cyclic di-GMP to provide Vibrio cholerae spatial cues within the small intestine.

    Science.gov (United States)

    Koestler, Benjamin J; Waters, Christopher M

    2014-01-01

    The second messenger cyclic di-GMP (c-di-GMP) regulates numerous phenotypes in response to environmental stimuli to enable bacteria to transition between different lifestyles. Here we discuss our recent findings that the human pathogen Vibrio cholerae recognizes 2 host-specific signals, bile and bicarbonate, to regulate intracellular c-di-GMP. We have demonstrated that bile acids increase intracellular c-di-GMP to promote biofilm formation. We have also shown that this bile-mediated increase of intracellular c-di-GMP is negated by bicarbonate, and that this interaction is dependent on pH, suggesting that V. cholerae uses these 2 environmental cues to sense and adapt to its relative location in the small intestine. Increased intracellular c-di-GMP by bile is attributed to increased c-di-GMP synthesis by 3 diguanylate cyclases (DGCs) and decreased expression of one phosphodiesterase (PDE) in the presence of bile. The molecular mechanisms by which bile controls the activity of the 3 DGCs and the regulators of bile-mediated transcriptional repression of the PDE are not yet known. Moreover, the impact of varying concentrations of bile and bicarbonate at different locations within the small intestine and the response of V. cholerae to these cues remains unclear. The native microbiome and pharmaceuticals, such as omeprazole, can impact bile and pH within the small intestine, suggesting these are potential unappreciated factors that may alter V. cholerae pathogenesis.

  7. Role of bicarbonate at the acceptor side of photosystem II

    NARCIS (Netherlands)

    Rensen, van J.J.S.

    2002-01-01

    Besides being the substrate for the carboxylation reaction of photosynthesis, CO2 (bicarbonate) is required for the activity of Photosystem II (water plastoquinone oxido-reductase). It plays a role on the electron donor side as well as the electron acceptor side. In this contribution, attention will

  8. Undisplayed Bicarbonate ion Concentration in Arterial Blood Gas Analysis

    OpenAIRE

    2013-01-01

    Blood bicarbonate ion concentration (BcHCO3-) is a vital parameter in the management of acid base disorders. In an arterial blood gas (ABG) analyzer, the BcHCO3- is calculated from the values of pH and pCO2.

  9. Use of Sodium Bicarbonate in Diabetic Hyperglycemic Emergencies

    Directory of Open Access Journals (Sweden)

    Diana Machado Ramírez

    2013-09-01

    Full Text Available Background: diabetic ketoacidosis and hyperosmolar hyperglycemic nonketotic state are two of the major metabolic emergencies that may occur. These conditions are not always treated properly.Objective: to describe the metabolic hyperglycemic emergencies in diabetic patients treated in the Intensive Care Unit, and to assess the use of sodium bicarbonate. Methods: a descriptive, cross-sectional study was conducted including 52 patients admitted to the Intensive Care Unit of the Enrique Cabrera Hospital from 2000 through 2007. The following variables were analyzed: type of diabetes mellitus, type of acute complication, use or not of sodium bicarbonate, blood gases, ionogram and progress of patients. Kitabchi criteria were used for the diagnosis of diabetic ketoacidosis and its severity and for the diagnosis of the hyperglycemic state as well. Criteria proposed by an Expert Committee of the American Diabetes Association and a World Health Organization Expert Committee were adopted for the diagnosis of diabetes and its classification. Results: diabetic ketoacidosis was confirmed in 57,5 % of type 1 diabetic patients and in 42,5 % of those with type 2 diabetes. Hyperosmolar hyperglycemic nonketotic state was observed in 23,0 % of type 2 diabetics. There was not any death among patients with diabetic ketoacidosis who did not use sodium bicarbonate whereas 80,0 % of patients with hyperglycemic state who used it died. Conclusions: diabetic ketoacidosis was the most common complication. Mortality due to ketoacidosis and hyperosmolar hyperglycemic nonketotic state was high. Sodium bicarbonate was not properly used.

  10. Regulation of Photosystem II Electron transport by Bicarbonate

    NARCIS (Netherlands)

    Rensen, van J.J.S.

    2012-01-01

    In oxygenic photosynthesis, carbon dioxide is fixed by ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and further reduced to carbohydrates. However, CO2, in the form of carbonate or bicarbonate, is also directly involved in the “light reactions” through structural and regulatory roles wit

  11. Bicarbonate exporting transporters in the ovine ruminal epithelium.

    Science.gov (United States)

    Bilk, S; Huhn, K; Honscha, K U; Pfannkuche, H; Gäbel, G

    2005-07-01

    In order to stabilize the intraruminal pH, bicarbonate secretion by the ruminal epithelium seems to be an important prerequisite. The present study therefore focussed on the characterization of bicarbonate exporting systems in ruminal epithelial cells. Intracellular pH (pH(i)) was measured spectrofluorometrically in primary cultured ruminal epithelial cells loaded with the pH-sensitive fluorescent dye, 2,7-bis(carboxyethyl)-5(6')-carboxyfluorescein acetomethyl ester. Switching from CO2/HCO3- -buffered to HEPES-buffered solution caused a rapid intracellular alkalinization followed by a counter-regulation towards initial pH(i). The recovery of pH(i) was dependent upon extracellular chloride, but independent of extracellular sodium. Adding 500 microM H2DIDS significantly reduced the increase of pH(i). For further characterization of the bicarbonate exporting systems, we tested the ability to reverse the direction from HCO3- export to import in the absence of sodium and chloride. Under sodium and chloride-free conditions, counter-regulation after CO2-induced pH(i) decrease did not differ from pH(i) recovery in the presence of sodium and chloride. Existence of bicarbonate exporting systems in cultured ruminal epithelial cells and intact ruminal epithelium was verified by reverse transcription polymerase chain reaction (RT-PCR). Using RT-PCR and subsequent sequencing, expression of mRNA encoding for AE2, DRA and PAT1 could be found. Bicarbonate exporting systems could therefore be detected both on the functional and structural level.

  12. Addition of sodium bicarbonate to complete pelleted diets fed to dairy calves.

    Science.gov (United States)

    Wheeler, T B; Wangsness, P J; Muller, L D; Griel, L C

    1980-11-01

    During two trials, 35 and 27 Holstein calves were fed ad libitum complete, pelleted diets containing either 35% alfalfa (Trial 1) or 35% grass (Trial 2) hay from birth to 12 wk of age. Calves in Trial 1 were fed one of the following diets: control, control + 3.5% sodium chloride, or control + 5% sodium bicarbonate. In Trial 2, diets were: control, control + 5% sodium bicarbonate, or control + 5% sodium bicarbonate + loose, chopped grass hay. Intake of dry matter, gain in body weight, ruminal pH, or fecal starch did not differ. Calves fed sodium bicarbonate in Trial 1 but not 2 had a reduced feed efficiency compared with control and supplemented diets. In Trial 1 added sodium bicarbonate did not alter intake or digestible energy. Addition of sodium bicarbonate increased concentration of ruminal acetate and butyrate and decreased propionate in both trials. Fecal pH was elevated in calves fed sodium bicarbonate diets during both trials. Sodium chloride increased water intake in Trial 1, and sodium bicarbonate increased water indigestible energy. Addition of sodium bicarbonate increased concentration of ruminal acetate and butyrate and decreased propionate in both trials. Fecal pH was elevated in calves fed sodium bicarbonate diets during both trials. Sodium chloride increased water intake in Trial 1, and sodium bicarbonate increased water indigestible energy. Addition of sodium bicarbonate increased concentration of ruminal acetate and butyrate and decreased propionate in both trials. Fecal pH was elevated in calves fed sodium bicarbonate diets during both trials. Sodium chloride increased water intake in Trial 1, and sodium bicarbonate increased water intake in Trial 2. Incidence of free-gas bloat was higher in calves fed sodium bicarbonate in both trials. Addition of sodium bicarbonate to complete pelleted diets containing 35% alfalfa or 35% grass hay appeared to have no benefit for young, growing dairy calves in performance and health.

  13. Type-1 cannabinoid receptors reduce membrane fluidity of capacitated boar sperm by impairing their activation by bicarbonate.

    Directory of Open Access Journals (Sweden)

    Barbara Barboni

    Full Text Available BACKGROUND: Mammalian spermatozoa acquire their full fertilizing ability (so called capacitation within the female genital tract, where they are progressively exposed to inverse gradients of inhibiting and stimulating molecules. METHODOLOGY/PRINCIPAL FINDINGS: In the present research, the effect on this process of anandamide, an endocannabinoid that can either activate or inhibit cannabinoid receptors depending on its concentration, and bicarbonate, an oviductal activatory molecule, was assessed, in order to study the role exerted by the type 1 cannabinoid receptor (CB1R in the process of lipid membrane remodeling crucial to complete capacitation. To this aim, boar sperm were incubated in vitro under capacitating conditions (stimulated by bicarbonate in the presence or in the absence of methanandamide (Met-AEA, a non-hydrolysable analogue of anandamide. The CB1R involvement was studied by using the specific inhibitor (SR141716 or mimicking its activation by adding a permeable cAMP analogue (8Br-cAMP. By an immunocytochemistry approach it was shown that the Met-AEA inhibits the bicarbonate-dependent translocation of CB1R from the post-equatorial to equatorial region of sperm head. In addition it was found that Met-AEA is able to prevent the bicarbonate-induced increase in membrane disorder and the cholesterol extraction, both preliminary to capacitation, acting through a CB1R-cAMP mediated pathway, as indicated by MC540 and filipin staining, EPR spectroscopy and biochemical analysis on whole membranes (CB1R activity and on membrane enriched fraction (C/P content and anisotropy. CONCLUSIONS/SIGNIFICANCE: Altogether, these data demonstrate that the endocannabinoid system strongly inhibits the process of sperm capacitation, acting as membrane stabilizing agent, thus increasing the basic knowledge on capacitation-related signaling and potentially opening new perspectives in diagnostics and therapeutics of male infertility.

  14. Metabolic Acidosis as a Complication of Bicarbonate Haemodialysis

    OpenAIRE

    Irshad Ahmad Sinval, Bassam Bernieh, Ahdulrahman Osman Mohamad, Mohamed Adnan Abbadi,Mossadeque Ahmed, Ahmad Abdelwahab AItabakh

    1999-01-01

    Twelve episodes ofsevere metabolic acidosis were observed among 10 maintenance dialysis patientsusing Bicarbonate Haemodialysis (HDB). Patients were stable at the start of haemodialysis (HO)and became sick during or following the procedure. The main clinical features observed wereabdominal pain and vomiting, hypotension or shock, and CNS manifestations. Laboratoryinvestigations revealed severe metabolic acidosis in all and hyperkalemia in 4 patients. On fouroccasions, dialysate fluid sample a...

  15. Oligomeric structure and minimal functional unit of the electrogenic sodium bicarbonate cotransporter NBCe1-A.

    Science.gov (United States)

    Kao, Liyo; Sassani, Pakan; Azimov, Rustam; Pushkin, Alexander; Abuladze, Natalia; Peti-Peterdi, Janos; Liu, Weixin; Newman, Debra; Kurtz, Ira

    2008-09-26

    The electrogenic sodium bicarbonate cotransporter NBCe1-A mediates the basolateral absorption of sodium and bicarbonate in the proximal tubule. In this study the oligomeric state and minimal functional unit of NBCe1-A were investigated. Wild-type (wt) NBCe1-A isolated from mouse kidney or heterologously expressed in HEK293 cells was predominantly in a dimeric state as was shown using fluorescence energy transfer, pulldown, immunoprecipitation, cross-linking experiments, and nondenaturing perfluorooctanoate-PAGE. NBCe1-A monomers were found to be covalently linked by S-S bonds. When each of the 15 native cysteine residues were individually removed on a wt-NBCe1-A backbone, dimerization of the cotransporter was not affected. In experiments involving multiple native cysteine residue removal, both Cys(630) and Cys(642) in extracellular loop 3 were shown to mediate S-S bond formation between NBCe1-A monomers. When native NBCe1-A cysteine residues were individually reintroduced into a cysteineless NBCe1-A mutant backbone, the finding that a Cys(992) construct that lacked S-S bonds functioned normally indicated that stable covalent linkage of NBCe1-A monomers was not a necessary requirement for functional activity of the cotransporter. Studies using concatameric constructs of wt-NBCe1-A, whose activity is resistant to methanesulfonate reagents, and an NBCe1-A(T442C) mutant, whose activity is completely inhibited by methanesulfonate reagents, confirmed that NBCe1-A monomers are functional. Our results demonstrate that wt-NBCe1-A is predominantly a homodimer, dependent on S-S bond formation that is composed of functionally active monomers.

  16. Bicarbonate-dependent secretion and proteolytic processing of recombinant myocilin.

    Directory of Open Access Journals (Sweden)

    José-Daniel Aroca-Aguilar

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

  17. Physiological carbon dioxide, bicarbonate, and pH sensing.

    Science.gov (United States)

    Tresguerres, Martin; Buck, Jochen; Levin, Lonny R

    2010-11-01

    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.

  18. Manganese complexes with bicarbonate and sulfate in natural water

    Science.gov (United States)

    Hem, J.D.

    1963-01-01

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

  19. Is bicarbonate stable in and on the calcite surface?

    DEFF Research Database (Denmark)

    Andersson, Martin Peter; Rodriguez Blanco, Juan Diego; Stipp, Susan Louise Svane

    2016-01-01

    We have used density functional theory with the COSMO-RS implicit solvent model to predict the pKa for the deprotonation of bicarbonate to carbonate, i.e. HCO3− CO32− + H+, when HCO3− is included in, and adsorbed on, a calcite surface. We have used cluster models (80–100 atoms) to represent...... the flat {10.4} surface, acute steps, obtuse steps, two types of kinks on the acute step and two types of kinks on the obtuse steps. Based on the predicted pKa values, which range from −6.0 to 2.4 depending on the surface site, we conclude that bicarbonate deprotonates to carbonate when it is in calcite...... even when pH in solution is very low. This is true for all surface sites, even for solutions where 2.4 calcite, the predicted pKa for deprotonation is 7.5, which is ∼3 pH units lower than in aqueous solution...

  20. Photosynthetic bicarbonate utilization in Porphyra haitanensis Bangiales,Rhodophyta

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The activities of carbonic anhydrase (CA) and photosynthesis of Porphyra haitanensis were investigated in order to see its photosynthetic utilization of inorganic carbon source. Both intra- and extra-cellular CA activities existed in the thallus. CA inhibitors, acetazolamide (AZ) and ethoxyzolamide (EZ), remarkably depressed the photosynthetic oxygen evolution in seawater of pH 8.2 and 10.0, and EZ showed stronger inhibition than AZ. The observed net photosynthetic rate in seawater of pH 8.2 was much higher than that of CO2 supply theoretically derived from spontaneous dehydration of HCO3-. P. haitanensis also showed a rather high pH compensation point (9.9). The results demonstrated that P. haitanensis could utilize bicarbonate as the external inorganic carbon source for photosynthesis. The bicarbonate utilization was closely associated with dehydration catalyzed by extracellular CA activity. The inorganic carbon composition in seawater could well saturate the photosynthesis of P. haitanensis. The low Km value and compensation points for inorganic carbon reflected the existence of CO2- concentrating mechanism in this alga.

  1. Pancreatic ductal bicarbonate secretion: challenge of the acinar acid load

    Directory of Open Access Journals (Sweden)

    Peter eHegyi

    2011-07-01

    Full Text Available Acinar and ductal cells of the exocrine pancreas form a close functional unit. Although most studies contain data either on acinar or ductal cells, an increasing number of evidence highlights the importance of the pancreatic acinar-ductal functional unit. One of the best examples for this functional unit is the regulation of luminal pH by both cell types. Protons co-released during exocytosis from acini cause significant acidosis, whereas, bicarbonate secreted by ductal cells cause alkalization in the lumen. This suggests that the first and probably one of the most important role of bicarbonate secretion by pancreatic ductal cells is not only to neutralize the acid chyme entering into the duodenum from the stomach, but to neutralize acidic content secreted by acinar cells. To accomplish this role, it is more than likely that ductal cells have physiological sensing mechanisms which would allow them to regulate luminal pH. To date, four different classes of acid-sensing ion channels have been identified in the gastrointestinal tract (transient receptor potential ion channels, two-pore domain potassium channel, ionotropic purinoceptor and acid-sensing ion channel, however, none of these have been studied in pancreatic ductal cells. In this mini-review, we summarize our current knowledge of these channels and urge scientists to characterize ductal acid-sensing mechanisms and also to investigate the challenge of the acinar acid load on ductal cells.

  2. Is Sodium Bicarbonate Therapy Still Up To Date?

    Directory of Open Access Journals (Sweden)

    Hüseyin Kurt

    2015-12-01

    Full Text Available Sodium bicarbonate (SB, which has a vital role in the regulation of acid-base balance of all tissues and organs, is one of the most important buffering systems of the body. SB plays an important role in the treatment of poisoning caused by numerous agents including mainly salicylate and tricyclic antidepressants. In metabolic acidosis (MA occurred in patient with systemic and metabolic diseases, first, the primary disease should be treated and in the case of low bicarbonate levels such as diarrhea and renal tubular acidosis, missing SB should be recovered. As the kidney has an important role in acid-base balance, SB is widely used in the treatment of acute and chronic renal failure. Although there is no conclusive evidence to prevent contrast nephropathy, SB comes to the fore compared to other agents. SB is used due to MA and its effects occurring in acute renal failure. In addition, SB treatment applied to reduce the increased acid levels in chronic kidney failure may reduce mortality. While SB can be used as individualized in lactic acidosis and cardiac arrest cases, it can be used safely as a performance enhancer for athletes. SB is used widely in gastrointestinal tract diseases due to its antacid effects and its routine use is not recommended in diabetic ketoacidosis. These data demonstrate that SB is still popular and it will retain its popularity in the near future.

  3. Regulation and roles of bicarbonate transport in cancer

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    Andrej eGorbatenko

    2014-04-01

    Full Text Available 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 towards 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 the 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 tumors, bicarbonate transporters such as the electroneutral Na+,HCO3--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 transport in cancer.

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

    Science.gov (United States)

    Kendra, Paul E; Montgomery, Wayne S; Epsky, Nancy D; Heath, Robert R

    2009-08-01

    At present, the most effective synthetic lures for pest Anastrepha fruit flies are multicomponent blends that include ammonia and the diamine synergist putrescine (1,4-diaminobutane). Both chemicals generally have been regarded as protein cues that result in female-biased attraction. Using electroantennography (EAG) and flight tunnel bioassays, this study evaluated response of the Caribbean fruit fly, Anastrepha suspensa (Loew) to vapors released from commercial lure formulations of ammonium bicarbonate and putrescine. Over a range of doses tested, EAG response to ammonium bicarbonate was equivalent for both sexes, but female response was significantly greater than male response to putrescine and to a 1:1 mixture of ammonium bicarbonate and putrescine. Amplitude of EAG response to the mixture was approximately equal to the summation of responses to the individual substrates. Using a fixed dose of substrate, EAG measurements from females 1-14 d old indicated that antennal sensitivity to both lures varied according to physiological state of the fly. Peak response to ammonium bicarbonate was recorded from immature females, peak response to putrescine from sexually mature females. In bioassays, more females were captured with ammonium bicarbonate plus putrescine than with ammonium bicarbonate alone. This difference was not observed in males, resulting in a higher female to male ratio in captures with ammonium bicarbonate plus putreseine (3:1) versus ammonium bicarbonate alone (1:1). Results suggest that separate olfactory receptors are involved in detection of the two semiochemicals, and that the putrescine component is primarily responsible for the female-biased attraction.

  5. Epoxidation of Alkenes with Aqueous Hydrogen Peroxide and Quaternary Ammonium Bicarbonate Catalysts

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Kegnæs, Søren

    2013-01-01

    A range of solid and liquid catalysts containing bicarbonate anions were synthesised and tested for the epoxidation of alkenes with aqueous hydrogen peroxide. The combination of bicarbonate anions and quaternary ammonium cations opens up for new catalytic systems that can help to overcome challen...

  6. Treatment with Potassium Bicarbonate Lowers Calcium Excretion and Bone Resorption in Older Men and Women

    Science.gov (United States)

    Bicarbonate has been implicated in bone health in older subjects on acid-producing diets in short-term studies. The objective of this study was to determine the effects of potassium bicarbonate and its components on changes in bone resorption and calcium excretion over 3 months in older men and wom...

  7. Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men

    DEFF Research Database (Denmark)

    Krustrup, Peter; Ermidis, Georgios; Mohr, Magni

    2015-01-01

    Background Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery level 2 test perfor...

  8. Intrahypothalamic corticotropin-releasing factor elevates gastric bicarbonate and inhibits stress ulcers in rats.

    Science.gov (United States)

    Gunion, M W; Kauffman, G L; Taché, Y

    1990-01-01

    The effects of intrahyopthalamic microinfusions of corticotropin-releasing factor (CRF) on gastric bicarbonate, acid, and pepsin content and on cold restraint-induced gastric lesion formation were tested in three experiments. Bilateral microinfusions of CRF into the hypothalamic ventromedial nucleus (0.86 nmol/rat) significantly increased both gastric bicarbonate concentration and total bicarbonate output. These effects were observed irrespective of whether rats were pretreated with the acid antisecretory drug omeprazole. In nonomeprazole-pretreated rats, CRF microinfusions also significantly reduced acid secretion and raised pH. The increase in bicarbonate content accounted for half of the observed decrease in acid output, suggesting that CRF microinfusions activated separable bicarbonate-stimulating and acid-inhibiting hypothalamic systems. In non-omeprazole-pretreated rats, CRF microinfusions significantly increased serum gastrin, whereas pepsin output was unchanged. Gastric mucosal damage produced by 4 h of cold restraint was significantly diminished by CRF microinfusion into the ventromedial hypothalamus. These data demonstrate that ventromedial hypothalamic microinfusions of CRF increase bicarbonate content, decrease gastric acid content, and confer protection against cold restraint-induced gastric mucosal damage. Hypothalamic CRF neuronal terminals and receptors may be involved in the central regulation of gastric bicarbonate secretion as well as acid secretion.

  9. Bicarbonate Secretion in the Murine Gallbladder - Lessons for the Treatment of Cystic Fibrosis

    Directory of Open Access Journals (Sweden)

    Cuthbert AW

    2001-07-01

    Full Text Available The epithelium lining the gallbladder of mammalian species has absorptive and secretory functions. An important function is the secretion of a bicarbonate rich fluid that helps neutralise stomach acid and provides an appropriate environment for intestinal enzymes. In cystic fibrosis (CF this secretory function is lost. This study concerns the bicarbonate secreting activity of murine gallbladders in vitro using wild type and CF mice and four main questions are considered as follows: a Does the murine gallbladder secrete bicarbonate electrogenically and is this prevented in CF? b Can the secretory activity in CF gallbladders be restored by gene therapy or pharmacologically? c How is the cystic fibrosis transmembrane conductance regulator (CFTR involved in bicarbonate secretion? d Does the data offer prospects for the treatment of CF?. Work from both the author's laboratory and the literature will be reviewed. Consideration of the currently available data indicates that the wild type murine gallbladder does secrete bicarbonate electrogenically and that this is absent in CF mice. Further it has been demonstrated that bicarbonate secretory activity can be restored by both gene therapy and by the use of drugs. The role of CFTR in bicarbonate secretion remains equivocal. Much evidence suggests that CFTR can act as a channel for HCO(3(- ions as well as Cl(- ions, while others propose a parallel arrangement of CFTR with a Cl(-/HCO(3(- exchanger is necessary. The matter is further complicated by the regulatory role of CFTR on other transporting activities. Opportunities for possible application to man are discussed.

  10. Toward an in vivo dissolution methodology: a comparison of phosphate and bicarbonate buffers.

    Science.gov (United States)

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

    2009-01-01

    The purpose of this research was 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. The intrinsic dissolution rates of ketoprofen and indomethacin were experimentally measured using a rotating disk method at 37 degrees 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. Experimental results show that the intrinsic dissolution rates of ketoprofen and indomethacin in USP and FaSSIF phosphate buffers are 1.5-3.0 times that in the 15 mM bicarbonates. Theoretical analysis demonstrates that the buffer differential is largely dependent on the drug pK(a) and second on solubility, and weakly dependent on the drug diffusivity. Further, in accordance with the drug pK(a), solubility and diffusivity, a 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. 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

  11. Bicarbonate Impact on U(VI) Bioreduction in a Shallow Alluvial Aquifer

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-01

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

  12. Detection of OXA-48-type carbapenemase-producing Enterobacteriaceae in diagnostic laboratories can be enhanced by addition of bicarbonates to cultivation media or reaction buffers.

    Science.gov (United States)

    Studentova, Vendula; Papagiannitsis, Costas C; Izdebski, Radoslaw; Pfeifer, Yvonne; Chudackova, Eva; Bergerova, Tamara; Gniadkowski, Marek; Hrabak, Jaroslav

    2015-03-01

    Carbapenemase-mediated resistance to carbapenems in Enterobacteriaceae has become the main challenge in the treatment and prevention of infections recently. The partially unnoticed spread of OXA-48-type carbapenemase producers is usually assigned to low minimum inhibitory concentrations (MICs) of carbapenems that OXA-48-producing isolates often display. Therefore, there is an urgent need of specific and sensitive methods for isolation and detection of OXA-48 producers in clinical microbiology diagnostics. The influence of bicarbonates on carbapenem MICs against carbapenemase-producing Enterobacteriaceae was tested. We also checked whether the addition of bicarbonates to liquid media supplemented with meropenem may facilitate the selective enrichment of various carbapenemase producers in cultures. Furthermore, the sensitivity of carbapenemase confirmation by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) and spectrophotometric hydrolysis assays upon the addition of NH4HCO3 was examined. The addition of NaHCO3 significantly increased MICs of ertapenem and meropenem for OXA-48 producers. Furthermore, liquid media supplemented with NaHCO3 and meropenem were reliable for the selective enrichment of carbapenemase producers. The presence of NH4HCO3 in buffers used in the spectrophotometric and MALDI-TOF MS carbapenemase detection increased the sensitivity of that assay. Our results demonstrate that bicarbonates in media or reaction buffers can enhance the sensitivity of screening methods and diagnostic tests for carbapenemase producers.

  13. Heterotrophic bicarbonate assimilation is the main process of de novo organic carbon synthesis in hadal zone of the Hellenic Trench, the deepest part of Mediterranean Sea.

    Science.gov (United States)

    Yakimov, Michail M; La Cono, Violetta; Smedile, Francesco; Crisafi, Francesca; Arcadi, Erika; Leonardi, Marcella; Decembrini, Franco; Catalfamo, Maurizio; Bargiela, Rafael; Ferrer, Manuel; Golyshin, Peter N; Giuliano, Laura

    2014-12-01

    Ammonium-oxidizing chemoautotrophic members of Thaumarchaea are proposed to be the key players in the assimilation of bicarbonate in the dark (ABD). However, this process may also involve heterotrophic metabolic pathways, such as fixation of carbon dioxide (CO2) via various anaplerotic reactions. We collected samples from the depth of 4900 m at the Matapan-Vavilov Deep (MVD) station (Hellenic Trench, Eastern Mediterranean) and used the multiphasic approach to study the ABD mediators in this deep-sea ecosystem. At this depth, our analysis indicated the occurrence of actively CO2-fixing heterotrophic microbial assemblages dominated by Gammaproteobacteria with virtually no Thaumarchaea present. [14C]-bicarbonate incorporation experiments combined with shotgun [14C]-proteomic analysis identified a series of proteins of gammaproteobacterial origin. More than quarter of them were closely related with Alteromonas macleodii ‘deep ecotype’ AltDE, the predominant organism in the microbial community of MVD. The present study demonstrated that in the aphotic/hadal zone of the Mediterranean Sea, the assimilation of bicarbonate is associated with both chemolithoauto- and heterotrophic ABD. In some deep-sea areas, the latter may predominantly contribute to the de novo synthesis of organic carbon which points at the important and yet underestimated role heterotrophic bacterial populations can play the in global carbon cycle/sink in the ocean interior.

  14. Central functions of bicarbonate in S-type anion channel activation and OST1 protein kinase in CO 2 signal transduction in guard cell

    KAUST Repository

    Xue, Shaowu

    2011-03-18

    Plants respond to elevated CO(2) via carbonic anhydrases that mediate stomatal closing, but little is known about the early signalling mechanisms following the initial CO(2) response. It remains unclear whether CO(2), HCO(3)(-) or a combination activates downstream signalling. Here, we demonstrate that bicarbonate functions as a small-molecule activator of SLAC1 anion channels in guard cells. Elevated intracellular [HCO(3)(-)](i) with low [CO(2)] and [H(+)] activated S-type anion currents, whereas low [HCO(3)(-)](i) at high [CO(2)] and [H(+)] did not. Bicarbonate enhanced the intracellular Ca(2+) sensitivity of S-type anion channel activation in wild-type and ht1-2 kinase mutant guard cells. ht1-2 mutant guard cells exhibited enhanced bicarbonate sensitivity of S-type anion channel activation. The OST1 protein kinase has been reported not to affect CO(2) signalling. Unexpectedly, OST1 loss-of-function alleles showed strongly impaired CO(2)-induced stomatal closing and HCO(3)(-) activation of anion channels. Moreover, PYR/RCAR abscisic acid (ABA) receptor mutants slowed but did not abolish CO(2)/HCO(3)(-) signalling, redefining the convergence point of CO(2) and ABA signalling. A new working model of the sequence of CO(2) signalling events in gas exchange regulation is presented.

  15. Metabolomic Responses of Guard Cells and Mesophyll Cells to Bicarbonate.

    Science.gov (United States)

    Misra, Biswapriya B; de Armas, Evaldo; Tong, Zhaohui; Chen, Sixue

    2015-01-01

    Anthropogenic CO2 presently at 400 ppm is expected to reach 550 ppm in 2050, an increment expected to affect plant growth and productivity. Paired stomatal guard cells (GCs) are the gate-way for water, CO2, and pathogen, while mesophyll cells (MCs) represent the bulk cell-type of green leaves mainly for photosynthesis. We used the two different cell types, i.e., GCs and MCs from canola (Brassica napus) to profile metabolomic changes upon increased CO2 through supplementation with bicarbonate (HCO3-). Two metabolomics platforms enabled quantification of 268 metabolites in a time-course study to reveal short-term responses. The HCO3- responsive metabolomes of the cell types differed in their responsiveness. The MCs demonstrated increased amino acids, phenylpropanoids, redox metabolites, auxins and cytokinins, all of which were decreased in GCs in response to HCO3-. In addition, the GCs showed differential increases of primary C-metabolites, N-metabolites (e.g., purines and amino acids), and defense-responsive pathways (e.g., alkaloids, phenolics, and flavonoids) as compared to the MCs, indicating differential C/N homeostasis in the cell-types. The metabolomics results provide insights into plant responses and crop productivity under future climatic changes where elevated CO2 conditions are to take center-stage.

  16. Metabolomic Responses of Guard Cells and Mesophyll Cells to Bicarbonate.

    Directory of Open Access Journals (Sweden)

    Biswapriya B Misra

    Full Text Available Anthropogenic CO2 presently at 400 ppm is expected to reach 550 ppm in 2050, an increment expected to affect plant growth and productivity. Paired stomatal guard cells (GCs are the gate-way for water, CO2, and pathogen, while mesophyll cells (MCs represent the bulk cell-type of green leaves mainly for photosynthesis. We used the two different cell types, i.e., GCs and MCs from canola (Brassica napus to profile metabolomic changes upon increased CO2 through supplementation with bicarbonate (HCO3-. Two metabolomics platforms enabled quantification of 268 metabolites in a time-course study to reveal short-term responses. The HCO3- responsive metabolomes of the cell types differed in their responsiveness. The MCs demonstrated increased amino acids, phenylpropanoids, redox metabolites, auxins and cytokinins, all of which were decreased in GCs in response to HCO3-. In addition, the GCs showed differential increases of primary C-metabolites, N-metabolites (e.g., purines and amino acids, and defense-responsive pathways (e.g., alkaloids, phenolics, and flavonoids as compared to the MCs, indicating differential C/N homeostasis in the cell-types. The metabolomics results provide insights into plant responses and crop productivity under future climatic changes where elevated CO2 conditions are to take center-stage.

  17. Treatment of metabolic acidosis in patients with stage 3 chronic kidney disease with fruits and vegetables or oral bicarbonate reduces urine angiotensinogen and preserves glomerular filtration rate.

    Science.gov (United States)

    Goraya, Nimrit; Simoni, Jan; Jo, Chan-Hee; Wesson, Donald E

    2014-11-01

    Alkali therapy of metabolic acidosis in patients with chronic kidney disease (CKD) with plasma total CO2 (TCO2) below 22 mmol/l per KDOQI guidelines appears to preserve estimated glomerular filtration rate (eGFR). Since angiotensin II mediates GFR decline in partial nephrectomy models of CKD and even mild metabolic acidosis increases kidney angiotensin II in animals, alkali treatment of CKD-related metabolic acidosis in patients with plasma TCO2 over 22 mmol/l might preserve GFR through reduced kidney angiotensin II. To test this, we randomized 108 patients with stage 3 CKD and plasma TCO2 22-24 mmol/l to Usual Care or interventions designed to reduce dietary acid by 50% using sodium bicarbonate or base-producing fruits and vegetables. All were treated to achieve a systolic blood pressure below 130 mm Hg with regimens including angiotensin converting enzyme inhibition and followed for 3 years. Plasma TCO2 decreased in Usual Care but increased with bicarbonate or fruits and vegetables. By contrast, urine excretion of angiotensinogen, an index of kidney angiotensin II, increased in Usual Care but decreased with bicarbonate or fruits and vegetables. Creatinine-calculated and cystatin C-calculated eGFR decreased in all groups, but loss was less at 3 years with bicarbonate or fruits and vegetables than Usual Care. Thus, dietary alkali treatment of metabolic acidosis in CKD that is less severe than that for which KDOQI recommends therapy reduces kidney angiotensin II activity and preserves eGFR.

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

    Directory of Open Access Journals (Sweden)

    Lonny R. Levin

    2011-02-01

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

  19. Serum Bicarbonate And Survival In Peritoneal Dialysis (Pd: Comparison With Hemodialysis (Hd

    Directory of Open Access Journals (Sweden)

    Tania Sharma

    2012-06-01

    Full Text Available Correction of metabolic acidosis is one of the goals of effective dialysis. The KDOQI guidelines recommend serum bicarbonate >22 meq/L irrespective of dialysis modality. Since the measured bicarbonate reflects the steady state in PD patients and the lowest inter-dialytic value in HD patients, we compared the survival predictability of serum bicarbonate 10,400 PD and 110,951 HD patients treated in DaVita facilities from 7/2001-6/2006 with follow-up through 6/2007. PD patients were substantially less likely to have lower serum bicarbonate (adjusted odds, 22 meq/L for all end-stage renal disease irrespective of dialysis modality.fx1

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

    Science.gov (United States)

    Philips , Elizabeth J.P.; Landa, Edward R.; Lovely, Derek R.

    1995-01-01

    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 the bicarbonate extracts. In some instances unidentified dissolved extracted components, presumably organics, gave the extract a yellow color and inhibited U(VI) reduction and/or the precipitation of U(IV). Removal of the dissolved yellow material with the addition of hydrogen peroxide alleviated this inhibition. These results demonstrate that bicarbonate extraction of uranium from soil followed by microbial U(VI) reduction might be an effective mechanism for concentrating uranium from some contaminated soils.

  1. Role of bicarbonate/CO2 in the inhibition of Escherichia coli growth by cyanate.

    Science.gov (United States)

    Kozliak, E I; Fuchs, J A; Guilloton, M B; Anderson, P M

    1995-06-01

    Cyanase is an inducible enzyme in Escherichia coli that catalyzes the reaction of cyanate with bicarbonate to give two CO2 molecules. The gene for cyanase is part of the cyn operon, which includes cynT and cynS, encoding carbonic anhydrase and cyanase, respectively. Carbonic anhydrase functions to prevent depletion of cellular bicarbonate during cyanate decomposition (the product CO2 can diffuse out of the cell faster than noncatalyzed hydration back to bicarbonate). Addition of cyanate to the culture medium of a delta cynT mutant strain of E. coli (having a nonfunctional carbonic anhydrase) results in depletion of cellular bicarbonate, which leads to inhibition of growth and an inability to catalyze cyanate degradation. These effects can be overcome by aeration with a higher partial CO2 pressure (M. B. Guilloton, A. F. Lamblin, E. I. Kozliak, M. Gerami-Nejad, C. Tu, D. Silverman, P. M. Anderson, and J. A. Fuchs, J. Bacteriol. 175:1443-1451, 1993). The question considered here is why depletion of bicarbonate/CO2 due to the action of cyanase on cyanate in a delta cynT strain has such an inhibitory effect. Growth of wild-type E. coli in minimal medium under conditions of limited CO2 was severely inhibited, and this inhibition could be overcome by adding certain Krebs cycle intermediates, indicating that one consequence of limiting CO2 is inhibition of carboxylation reactions. However, supplementation of the growth medium with metabolites whose syntheses are known to depend on a carboxylation reaction was not effective in overcoming inhibition related to the bicarbonate deficiency induced in the delta cynT strain by addition of cyanate. Similar results were obtained with a deltacyn strain (since cyanase is absent, this strain does not develop a bicarbonate deficiency when cyanate is added); however, as with the deltacynT strain, a higher partial CO(2) pressure in the aerating gas or expression of carbonic anhydrase activity (which contributes to a higher intercellular

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

    OpenAIRE

    Mizote, T; Yoshiyama, H; T. Nakazawa

    1997-01-01

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

  3. Acetate and bicarbonate assimilation and metabolite formation in Chlamydomonas reinhardtii: a 13C-NMR study.

    Directory of Open Access Journals (Sweden)

    Himanshu Singh

    Full Text Available Cellular metabolite analyses by (13C-NMR showed that C. reinhardtii cells assimilate acetate at a faster rate in heterotrophy than in mixotrophy. While heterotrophic cells produced bicarbonate and CO2aq, mixotrophy cells produced bicarbonate alone as predominant metabolite. Experiments with singly (13C-labelled acetate ((13CH(3-COOH or CH(3-(13COOH supported that both the (13C nuclei give rise to bicarbonate and CO2(aq. The observed metabolite(s upon further incubation led to the production of starch and triacylglycerol (TAG in mixotrophy, whereas in heterotrophy the TAG production was minimal with substantial accumulation of glycerol and starch. Prolonged incubation up to eight days, without the addition of fresh acetate, led to an increased TAG production at the expense of bicarbonate, akin to that of nitrogen-starvation. However, such TAG production was substantially high in mixotrophy as compared to that in heterotrophy. Addition of mitochondrial un-coupler blocked the formation of bicarbonate and CO2(aq in heterotrophic cells, even though acetate uptake ensued. Addition of PSII-inhibitor to mixotrophic cells resulted in partial conversion of bicarbonate into CO2(aq, which were found to be in equilibrium. In an independent experiment, we have monitored assimilation of bicarbonate via photoautotrophy and found that the cells indeed produce starch and TAG at a much faster rate as compared to that in mixotrophy and heterotrophy. Further, we noticed that the accumulation of starch is relatively more as compared to TAG. Based on these observations, we suggest that acetate assimilation in C. reinhardtii does not directly lead to TAG formation but via bicarbonate/CO2(aq pathways. Photoautotrophic mode is found to be the best growth condition for the production of starch and TAG and starch in C. reinhardtii.

  4. Carbonic Anhydrase: In the Driver's Seat for Bicarbonate Transport

    Directory of Open Access Journals (Sweden)

    Sterling D

    2001-07-01

    Full Text Available Carbonic anhydrases are a widely expressed family of enzymes that catalyze the reversible reaction: CO(2 + H(2O = HCO(3(- + H(+. These enzymes therefore both produce HCO(3(- for transport across membranes and consume HCO(3(- that has been transported across membranes. Thus these enzymes could be expected to have a key role in driving the transport of HCO(3(- across cells and epithelial layers. Plasma membrane anion exchange proteins (AE transport chloride and bicarbonate across most mammalian membranes in a one-for-one exchange reaction and act as a model for our understanding of HCO(3(- transport processes. Recently it was shown that AE1, found in erythrocytes and kidney, binds carbonic anhydrase II (CAII via the cytosolic C-terminal tail of AE1. To examine the physiological consequences of the interaction between CAII and AE1, we characterized Cl(-/HCO(3(- exchange activity in transfected HEK293 cells. Treatment of AE1-transfected cells with acetazolamide, a CAII inhibitor, almost fully inhibited anion exchange activity, indicating that endogenous CAII activity is essential for transport. Further experiments to examine the role of the AE1/CAII interaction will include measurements of the transport activity of AE1 following mutation of the CAII binding site. In a second approach a functionally inactive CA mutant, V143Y, will be co-expressed with AE1 in HEK293 cells. Since over expression of V143Y CAII would displace endogenous wild-type CAII from AE1, a loss of transport activity would be observed if binding to the AE1 C-terminus is required for transport.

  5. Intravenous bicarbonate and sodium chloride both prolong endurance during intense cycle ergometer exercise.

    Science.gov (United States)

    Mitchell, T H; Abraham, G; Wing, S; Magder, S A; Cosio, M G; Deschamps, A; Marliss, E B

    1990-08-01

    To determine the effects of neutralizing exercise systemic acidosis via the intravenous route upon endurance and metabolic responses, eight lean, normal, postabsorptive men exercised to exhaustion at about 80% of their VO2 max (69 +/- 3%, mean +/- SEM, of maximum power output) on a cycle ergometer. Exercise studies were performed either with no infusion (control) or with a total infusion volume of about 1.5 L, mainly as 1.3% sodium bicarbonate or as 0.9% sodium chloride (NaCl), infused (double-blind) throughout exercise. The sodium bicarbonate was to prevent acid-base change, the sodium chloride was as a control for the volume infused. Arterialized venous blood and breath-by-breath analysis of expired gases were obtained. [H+] (nmol.L-1) and [HCO3-] (mmol.L-1) at exhaustion were similar in control and NaCl (46.5 +/- 1.8, 19.9 +/- 0.9), but remained unchanged from rest values with bicarbonate (38.4 +/- 0.9, 24.8 +/- 1.5, p less than 0.005 vs control and NaCl). At exhaustion, VO2, VCO2, RER, heart rate, and systolic BP as well as FFA, glycerol, alanine, insulin, norepinephrine, and epinephrine did not differ among protocols. Endurance was markedly prolonged (p less than 0.01) with bicarbonate (31.9 +/- 5.8 min) and NaCl (31.8 +/- 4.1 min) compared with the control (19.0 +/- 2.9 min) condition. Plasma glucose at exhaustion was higher (p less than 0.025) in the control compared to bicarbonate and NaCl experiments, while lactate was higher (p less than 0.025) in the bicarbonate than in the control and NaCl experiments. Thus, the prolonged endurance with sodium bicarbonate infusion could not be explained either by its effect of maintaining blood acid-base equilibrium or concomitant metabolic changes.

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

    Science.gov (United States)

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

    2013-01-01

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

  7. Regulation of duodenal bicarbonate secretion during stress by corticotropin-releasing factor and beta-endorphin.

    Science.gov (United States)

    Lenz, H J

    1989-02-01

    Proximal duodenal mucosal bicarbonate secretion is an important factor in the pathogenesis of duodenal ulcer disease. To examine the central nervous system regulation of duodenal bicarbonate secretion, an animal model was developed that allowed cerebroventricular and intravenous injections as well as collection of duodenal perfusates in awake, freely moving rats. The hypothalamic peptide corticotropin-releasing factor (CRF) and stress (physical restraint) significantly stimulated duodenal bicarbonate secretion. These responses were abolished by pretreatment of the animals with the CRF receptor antagonist alpha-helical CRF-(9-41), hypophysectomy, and naloxone. In contrast, blockade of autonomic efferents by surgical and pharmacological means did not prevent the stimulatory effects of stress and CRF. Intravenous, but not cerebroventricular, administration of beta-endorphin that produced plasma concentrations of beta-endorphin that were similar to those produced by exogenous CRF and stress significantly stimulated duodenal bicarbonate secretion. These results indicate that endogenous CRF released during stress and exogenously administered CRF stimulate duodenal bicarbonate secretion by release of beta-endorphin from the pituitary, thus, demonstrating a functional hypothalamus-pituitary-gut axis.

  8. Interactive Effects of the Carbon Paper, Sodium Bicarbonate and Oral Contraceptive Pills on Morphine Urine Test

    Directory of Open Access Journals (Sweden)

    Solhi, H

    2010-01-01

    Full Text Available Background and objectives: A major problem for labs. esp. medicolegal centers is drug test false positive and negative results. Using carbonpaper, sodium bicarbonate or oral contraceptive pills (OCP are commonamong addict people to make the results negative. Therefore, we decidedto evaluate the effect of carbon paper, sodium bicarbonate or OCP onmorphine urine test.Material and Methods: We performed this pre-experimental study onthe urine samples of all people referred to narcotic drug laboratory ofMarkazi province during May of 2005. Of 2110 urine samples, theMorphine Rapid Test of 208 samples was positive. Then by means ofTLC method, we confirmed the presence of morphine metabolites in 150urine samples. After that, we divided these samples into three equalgroups for adding carbon paper, sodium bicarbonate or OCP.Results: The results show that in carbon paper group, 41 cases arepositive and nine cases unclear. In sodium bicarbonate group, 45 samplesare positive and 5 cases unclear. In estrogen conjugate group, all 50samples are positive.Conclusion: According to this study, adding carbon paper, sodiumbicarbonate or oral contraceptive pills cannot make negative theMorphine Rapid Test result.Key words: Morphine Rapid Test, Carbon paper, Sodium bicarbonate,Oral contraceptive pill.

  9. Mechanisms behind changes in gastric acid and bicarbonate outputs during the human interdigestive motility cycle.

    Science.gov (United States)

    Dalenbäck, J; Fändriks, L; Olbe, L; Sjövall, H

    1996-01-01

    Human gastric interdigestive acid and bicarbonate outputs vary cyclically in association with the migrating motor complex (MMC). These phenomena were studied in 26 healthy volunteers by constant-flow gastric perfusion, with continuous recording of pH and Pco2 in mixed gastric effluent and concomitant open-tip manometry of gastroduodenal motility. Stable acid and bicarbonate outputs were registered during less than 50% of the MMC cycle. Acid secretion started to increase 71 +/- 3% into the cycle, with maximum output during antral phase III. Bicarbonate output increased biphasically 1) 40 +/- 5% into the cycle, coinciding with reflux of bile, and 2) at the end of duodenal phase III when the aspirate was devoid of bile. The bicarbonate peak associated with phase III was abolished by atropine (0.01 mg/kg iv, n = 8) and by pyloric occlusion (n = 9) but remained unchanged after omeprazole (n = 10). The acid peak was abolished by both atropine and omeprazole. It is concluded that the MMC-related changes in acid and alkaline outputs represent two different and independent phenomena. Acid secretion cyclicity is due to periodical variations in cholinergic stimulation of the parietal cells. In contrast, the phase III-associated increase in bicarbonate output is due to duodenogastric reflux.

  10. Sulphate-bicarbonate mineral waters in the treatment of biliary and digestive tract diseases.

    Science.gov (United States)

    Fraioli, A; Menunni, G; Petraccia, L; Fontana, M; Nocchi, S; Grassi, M

    2010-01-01

    The authors point out the therapeutic properties of sulphate-bicarbonate mineral waters. After summarizing the general mechanism of action of mineral waters, the main indications of such waters in thermal treatment are examined including: biliary sand, biliary dyskinesia, functional dyspepsia, irritable colon, chronic primitive constipation. The dysfunctions of biliary and digestive tracts are growing, mainly in the affluent world, because of the increase for stress, dietary habits, modern life style. Now they affect from 2,4% of general population to 7% of men and 20% of women, according to different studies. Mineral waters can improve symptoms and care some physiopathological underlying mechanisms. Authors stress the efficacy of sulphate-bicarbonate mineral waters in the therapy of biliary dyskinesias, namely gallbladder hypokinesia and Oddi's sphincter spasm, caused by their content in SO4 = anion and Mg++ cation and related effects on paracrine-endocrine gastrointestinal system. In addition, they report the effects of sulphate-bicarbonate mineral waters in the lithogenic bile (sand bile), because of their diluting and washing activity. Among the sulphate-bicarbonate mineral waters, the Authors outline the well-documented therapeutic activity of Acqua Santa and Fucoli of Chianciano Terme. Acqua Santa has stimulating effect on cholecystis's motility, as proved by controlled clinical trials. Finally, the therapeutic use of sulphate-bicarbonate mineral water is discussed in functional dyspepsia, chronic primitive constipation and irritable bowel syndrome.

  11. Bicarbonate increases binding affinity of Vibrio cholerae ToxT to virulence gene promoters.

    Science.gov (United States)

    Thomson, Joshua J; Withey, Jeffrey H

    2014-11-01

    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.

  12. [Involvement of carbonate/bicarbonate ions in the superoxide-generating reaction of adrenaline autoxidation].

    Science.gov (United States)

    Sirota, T V

    2015-01-01

    An important role of carbonate/bicarbonate ions has been recognized in the superoxide generating reaction of adrenaline autooxidation in an alkaline buffer (a model of quinoid adrenaline oxidation in the body). It is suggested that these ions are directly involved not only in formation of superoxide anion radical (О(2)(-)) but also other radicals derived from the carbonate/bicarbonate buffer. Using various buffers it was shown that the rate of accumulation of adrenochrome, the end product of adrenaline oxidation, and the rate of О(2)(-)· formation depend on concentration of carbonate/bicarbonate ions in the buffer and that these ions significantly accelerate adrenaline autooxidation thus demonstrating prooxidant properties. The detectable amount of diformazan, the product of nitro blue tetrazolium (NBT) reduction, was significantly higher than the amount of adrenochrome formed; taking into consideration the literature data on О(2)(-)· detection by NBT it is suggested that adrenaline autooxidation is accompanied by one-electron reduction not only of oxygen dissolved in the buffer and responsible for superoxide formation but possible carbon dioxide also dissolved in the buffer as well as carbonate/bicarbonate buffer components leading to formation of corresponding radicals. The plots of the dependence of the inhibition of adrenochrome and diformazan formation on the superoxide dismutase concentration have shown that not only superoxide radicals are formed during adrenaline autooxidation. Since carbonate/bicarbonate ions are known to be universally present in the living nature, their involvement in free radical processes proceeding in the organism is discussed.

  13. Differential Responses of Two Lactuca sativa Varieties to Bicarbonate-Induced Iron Deficiency

    Directory of Open Access Journals (Sweden)

    Mohamed Chebbi

    2013-11-01

    Full Text Available Iron chlorosis induced by bicarbonate is very common in calcareous soils, where bicarbonate (HCO3- ions are present at high concentrations. In this study, morpho-physiological and biochemical responses of two Lactuca sativa varieties (Romaine and Vista to bicarbonate induced iron deficiency were investigated. The culture was conducted on nutrient solution containing 5 µM Fe and 10 mM NaHCO3, in a growth chamber with controlled conditions. After 14 days of bicarbonate treatment, the two varieties seedling showed a slight yellowing of young leaves associated with a significant decline of plant biomass, leaf number and area. Furthermore, the concentrations of the nutrient elements (potassium, magnesium, iron and calcium in leaves and roots of two lettuce varieties were modified. In roots of bicarbonate treated plants, the Fe-chelate reductase activity was increased as compared to control in both varieties. PEPC activity was enhanced only in Vista variety. Moreover, Fe deficiency induced a small change in the photosynthetic parameters and chlorophyll fluorescence, especially in Romaine variety. These changes are accompanied by decreases in ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco activity. These findings indicated that Vista variety could survive at low iron supply.

  14. Exchange equilibria between bicarbonate, carbonate, chloride and bromide on dowex 1 x 8.

    Science.gov (United States)

    Lundström, U; Olin, A

    1984-07-01

    The exchange reaction 2R(+)HCO(3)(2-) + CO(3)(2-) right harpoon over left harpoon R(2)(+) CO(3)(2-) + 2HCO(3)(2-) has been studied on Dowex 1 x 8 in the presence of bicarbonate solution in equilibrium with atmospheric carbon dioxide (open system). The experiments showed, as theory predicts, that the composition of the resin phase is independent of the concentration of the bicarbonate solution. The mole fraction of carbonate at equilibrium is about 0.4 and the equilibrium constant is 0.15M at 20 degrees . With this value of the constant, the composition of the ion-exchanger for various bicarbonate concentrations has been calculated for a closed system. At [HCO(3)(-)] Chromatographie enrichment of bromide from fresh water.

  15. A Literature Review of the Use of Sodium Bicarbonate for the Treatment of QRS Widening.

    Science.gov (United States)

    Bruccoleri, Rebecca E; Burns, Michele M

    2016-03-01

    Sodium bicarbonate is a well-known antidote for tricyclic antidepressant (TCA) poisoning. It has been used for over half a century to treat toxin-induced sodium channel blockade as evidenced by QRS widening on the electrocardiogram (ECG). The purpose of this review is to describe the literature regarding electrophysiological mechanisms and clinical use of this antidote after poisoning by tricyclic antidepressants and other agents. This article will also address the literature supporting an increased serum sodium concentration, alkalemia, or the combination of both as the responsible mechanism(s) for sodium bicarbonate's antidotal properties. While sodium bicarbonate has been used as a treatment for cardiac sodium channel blockade for multiple other agents including citalopram, cocaine, flecainide, diphenhydramine, propoxyphene, and lamotrigine, it has uncertain efficacy with bupropion, propranolol, and taxine-containing plants.

  16. Isotope composition of bicarbonate carbon in bed waters of oil and gas deposits

    Energy Technology Data Exchange (ETDEWEB)

    Golyshev, S.I.; Cherepnin, A.V.; Ivanov, V.G.; Manylova, L.S.

    1981-01-01

    A study is made of the isotope composition of bicarbonate carbon in bed waters of the Jurassic water complex in southeast West Siberia. It has been established that waters of empty and transcontour structures have isotope composition of carbon 5/sup 0//oo, while in waters which contact the hydrocarbon formations, the isotope composition of carbon is lighter on the average by 5-8/sup 0//oo. The isotope composition of bicarbonate carbon in bed waters reflects both the conditions for primary sedimentation, and secondary processes associated with organic matter transformation.

  17. Effect of sodium bicarbonate administration on mortality in patients with lactic acidosis: a retrospective analysis.

    Directory of Open Access Journals (Sweden)

    Hyun Jeong Kim

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

  18. Highly efficient hydrogen storage system based on ammonium bicarbonate/formate redox equilibrium over palladium nanocatalysts.

    Science.gov (United States)

    Su, Ji; Yang, Lisha; Lu, Mi; Lin, Hongfei

    2015-03-01

    A highly efficient, reversible hydrogen storage-evolution process has been developed based on the ammonium bicarbonate/formate redox equilibrium over the same carbon-supported palladium nanocatalyst. This heterogeneously catalyzed hydrogen storage system is comparable to the counterpart homogeneous systems and has shown fast reaction kinetics of both the hydrogenation of ammonium bicarbonate and the dehydrogenation of ammonium formate under mild operating conditions. By adjusting temperature and pressure, the extent of hydrogen storage and evolution can be well controlled in the same catalytic system. Moreover, the hydrogen storage system based on aqueous-phase ammonium formate is advantageous owing to its high volumetric energy density.

  19. Electroencephalogram investigations of the disequilibrium syndrome during bicarbonate and acetate dialysis.

    Science.gov (United States)

    Hampl, H; Klopp, H W; Michels, N; Mahiout, A; Schilling, H; Wolfgruber, M; Schiller, R; Hanefeld, F; Kessel, M

    1983-01-01

    Continuous long-time electroencephalographic (EEG) monitoring was performed during acetate and bicarbonate dialysis in 20 patients. Persisting normal basic activity of the EEG without neurological symptoms was found only during the course of bicarbonate dialysis. However, in acetate dialysis, during the decrease of arterial CO2 tension (PaCO2), we registered EEG disturbances with moderate to severe slowing, dysrhythmic activity and high voltage discharges. The decrease in PaCO2 and the deterioration in EEG activity in the patients during acetate dialysis was concomitant with severe neurological alterations, e.g. the typical symptoms of so-called 'disequilibrium' causing a cessation of dialysis in three patients.

  20. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise

    DEFF Research Database (Denmark)

    Marriott, Matthaus; Krustrup, Peter; Mohr, Magni

    2015-01-01

    intermittent exercise performance and metabolic markers under exercise-induced acidification, intense arm-cranking exercise was performed prior to intense intermittent running after intake of placebo, caffeine and sodium bicarbonate. METHODS: Male team-sports athletes (n = 12) ingested sodium bicarbonate (Na...

  1. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise

    DEFF Research Database (Denmark)

    Marriott, Matthaus; Krustrup, Peter; Mohr, Magni

    2015-01-01

    BACKGROUND: Caffeine and sodium bicarbonate ingestion have been suggested to improve high-intensity intermittent exercise, but it is unclear if these ergogenic substances affect performance under provoked metabolic acidification. To study the effects of caffeine and sodium bicarbonate on intense ...

  2. The Use of Sodium Bicarbonate in the Treatment of Acidosis in Sepsis: A Literature Update on a Long Term Debate

    Directory of Open Access Journals (Sweden)

    Dimitrios Velissaris

    2015-01-01

    Full Text Available Introduction. Sepsis and its consequences such as metabolic acidosis are resulting in increased mortality. Although correction of metabolic acidosis with sodium bicarbonate seems a reasonable approach, there is ongoing debate regarding the role of bicarbonates as a therapeutic option. Methods. We conducted a PubMed literature search in order to identify published literature related to the effects of sodium bicarbonate treatment on metabolic acidosis due to sepsis. The search included all articles published in English in the last 35 years. Results. There is ongoing debate regarding the use of bicarbonates for the treatment of acidosis in sepsis, but there is a trend towards not using bicarbonate in sepsis patients with arterial blood gas pH>7.15. Conclusions. Routine use of bicarbonate for treatment of severe acidemia and lactic acidosis due to sepsis is subject of controversy, and current opinion does not favor routine use of bicarbonates. However, available evidence is inconclusive, and more studies are required to determine the potential benefit, if any, of bicarbonate therapy in the sepsis patient with acidosis.

  3. Decreased cerebral blood flow after administration of sodium bicarbonate in the distressed newborn infant

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Fris-Hansen, B

    1978-01-01

    with 1 to 8 meqs of sodium bicarbonate in seven distressed newborn infants. The 133 Xe clearance technique was used. The results showed in six of the seven cases a decrease in cerebral blood flow, which in most cases was reduced to 14 to 22 ml/100 g/min, which is about half the value prior...

  4. The anaerobic conversion of methanol under thermophilic conditions: pH and bicarbonate dependence

    NARCIS (Netherlands)

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

    2003-01-01

    The thermophilic (55degreesC) anaerobic conversion of methanol was studied in an unbuffered medium (pH 4 +/- 0.2) and in a phosphate buffered medium (pH 6.4 +/- 0.1), in both cases without bicarbonate addition. Our cultivated sludge consortium was unable to degrade methanol under acidic conditions.

  5. Radiolysis of aqueous solutions of ammonium bicarbonate over a large dose range

    DEFF Research Database (Denmark)

    Draganic, Z.D.; Negrón-Mendoza, A.; Sehested, K.;

    1991-01-01

    Oxygen-free aqueous solutions of 0.05 mol dm-3 ammonium and sodium bicarbonate were studied after receiving various doses of Co-60 gammas (0.01-400 kGy) or 0.5-20 Gy pulses of 10 Mev electrons. Formate and oxalate were found to be the main radiolytic products, in addition to trace amounts of form...

  6. EFFECTS OF SODIUM BICARBONATE INGESTION ON SWIM PERFORMANCE IN YOUTH ATHLETES

    Directory of Open Access Journals (Sweden)

    Jozef Langfort

    2009-03-01

    Full Text Available 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 1st minute passive rest interval twice, on two occasions: after ingestion of bicarbonate or placebo, 72 hours apart, at the same time of the day. Blood samples were drawn from the finger tip three times during each trial; upon arrival to the laboratory, 60 min after ingestion of placebo or the sodium bicarbonate solution and after the 4 x 50m test, during the 1st min of recovery. Plasma lactate concentration, blood pH, standard bicarbonate and base excess were evaluated. The total time of the 4 x 50 m test trial improved from 1.54.28 to 1.52.85s, while statistically significant changes in swimming speed were recorded only during the first 50m sprint (1.92 vs. 1.97 m·s-1, p < 0.05. Resting blood concentration of HCO-3 increased following the ingestion of sodium bicarbonate from 25.13 to 28.49 mM (p < 0.05. Sodium bicarbonate intake had a statistically significant effect on resting blood pH (7.33 vs. 7.41, p < .05 as well as on post exercise plasma lactate concentration (11.27 vs. 13.06 mM, p < 0.05. Collectively, these data demonstrate that the ingestion of sodium bicarbonate in youth athletes is an effective buffer during high intensity interval swimming and suggest that such a procedure can be used in youth athletes to increase training intensity as well as swimming performance in competition at distances from 50 to 200 m

  7. Long-term oral sodium bicarbonate supplementation does not improve serum albumin levels in hemodialysis patients.

    Science.gov (United States)

    Bossola, Maurizio; Giungi, Stefania; Tazza, Luigi; Luciani, Giovanna

    2007-01-01

    Metabolic acidosis, a frequent event in hemodialysis patients, has been implicated as a potential cause of protein-energy malnutrition. Unfortunately, correction of metabolic acidosis by means of high bicarbonate concentration in the dialysate does not seem to lead to significant changes in nutritional parameters. The project was a single-arm, open-label, 12-month pilot study at a university-based tertiary care center aimed at evaluating whether correction of metabolic acidosis through long-term oral sodium bicarbonate supplementation improves serum albumin levels and other nutritional parameters in patients undergoing maintenance hemodialysis. Twenty highly acidotic hemodialysis patients patients were invited to consume an oral supplementation of sodium bicarbonate (1 g, thrice daily), for 12 months. Patients were followed at baseline and every month, until month 12. At each follow-up visit, dry body weight, BMI, blood pressure, presence of edema, venous bicarbonate, and serum albumin were measured. Total lymphocyte count, fasting total cholesterol and C-reactive protein were assessed every 2 months. At baseline and at 12 months, the subjective global assessment of nutritional status and the protein equivalent of nitrogen appearance normalized to actual body weight were determined. Plasma bicarbonate level rose from 18.1 +/- 2.7 to 22.1 +/- 4.5 mmol/l after 10 months (p = 0.001). Mean serum albumin levels were 3.8 +/- 0.2 mg/dl at baseline and 3.9 +/- 0.2 at the end of the study. Repeated measure ANOVA showed that there was no significant effect of bicarbonate treatment on serum albumin levels (p = 0.29), dry weight (p = 0.1), serum total cholesterol (p = 0.97), total lymphocyte count (p = 0.69), or C-reactive protein (p = 0.85). Mean subjective global assessment score was 4.53 +/- 0.37 at baseline and 4.58 +/- 0.54 at 12 months (p = 0.1). Mean nPNA (g/kg/day) was 0.86 +/- 0.05 at baseline and 0.85 +/- 0.08 at month 12. The present study demonstrates that long

  8. The effect of sodium bicarbonate on cytokine secretion in CKD patients with metabolic acidosis.

    Science.gov (United States)

    Ori, Yaacov; Zingerman, Boris; Bergman, Michael; Bessler, Hanna; Salman, Hertzel

    2015-04-01

    The incidence of acidosis increases with the progression of chronic kidney disease (CKD). Correction of acidosis by sodium bicarbonate may slow CKD deterioration. Inflammation, which is common in CKD, may be related to acidosis. Whether the slower rate of GFR decline following the correction of acidosis is related to changes in inflammatory markers is unknown. The current study examined whether correcting CKD-acidosis affected inflammatory cytokines secretion. Thirteen patients with CKD 4-5 and acidosis were tested for cytokines secretion from peripheral-blood mononuclear cells at baseline and after one month of oral sodium bicarbonate. Following treatment with sodium bicarbonate there was no change in weight, blood pressure, serum creatinine, albumin, sodium, calcium, phosphate, PTH, hemoglobin and CRP. Serum urea decreased (134±10-116±8 mg/dl, P=0.002), potassium decreased (5.1±0.4-4.8±0.1 mequiv./l, P=0.064), pH increased (7.29±0.01-7.33±0.01, P=0.008), and serum bicarbonate increased (18.6±0.4 mequiv./l to 21.3±0.3 mequiv./l, P=0.001). The secretion of the anti-inflammatory cytokine IL-10 decreased (2.75±0.25 ng/ml to 2.29±0.21 ng/ml, P=0.041). There was no significant change in the secretion of the other pro-inflammatory and anti-inflammatory cytokines, including IL-1β, IL-2, IL-6, TNFα, IFNγ, IL-1ra. Thus, correcting acidosis in CKD with bicarbonate decreases IL-10 secretion. Its significance needs to be further investigated.

  9. A low serum bicarbonate concentration as a risk factor for mortality in peritoneal dialysis patients.

    Directory of Open Access Journals (Sweden)

    Tae Ik Chang

    Full Text Available BACKGROUND AND AIM: Metabolic acidosis is common in patients with chronic kidney disease and is associated with increased mortality in hemodialysis patients. However, this relationship has not yet been determined in peritoneal dialysis (PD patients. METHODS: This prospective observational study included a total of 441 incident patients who started PD between January 2000 and December 2005. Using time-averaged serum bicarbonate (TA-Bic levels, we aimed to investigate whether a low serum bicarbonate concentration can predict mortality in these patients. RESULTS: Among the baseline parameters, serum bicarbonate level was positively associated with hemoglobin level and residual glomerular filtration rate (GFR, while it was negatively associated with albumin, C-reactive protein (CRP levels, peritoneal Kt/V urea, and normalized protein catabolic rate (nPCR in a multivariable linear regression analysis. During a median follow-up of 34.8 months, 149 deaths were recorded. After adjustment for age, diabetes, coronary artery disease, serum albumin, ferritin, CRP, residual GFR, peritoneal Kt/V urea, nPCR, and percentage of lean body mass, TA-Bic level was associated with a significantly decreased risk of mortality (HR per 1 mEq/L increase, 0.83; 95% CI, 0.76-0.91; p < 0.001. In addition, compared to patients with a TA-Bic level of 24-26 mEq/L, those with a TA-Bic level < 22 and between 22-24 mEq/L conferred a 13.10- and 2.13-fold increased risk of death, respectively. CONCLUSIONS: This study showed that a low serum bicarbonate concentration is an independent risk factor for mortality in PD patients. This relationship between low bicarbonate levels and adverse outcome could be related to enhanced inflammation and a more rapid loss of RRF associated with metabolic acidosis. Large randomized clinical trials to correct acidosis are warranted to confirm our findings.

  10. Sodium bicarbonate-based hydration prevents contrast-induced nephropathy: a meta-analysis

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    Tamhane Umesh

    2009-05-01

    Full Text Available Abstract Background Contrast-induced nephropathy is the leading cause of in-hospital acute renal failure. This side effect of contrast agents leads to increased morbidity, mortality, and health costs. Ensuring adequate hydration prior to contrast exposure is highly effective at preventing this complication, although the optimal hydration strategy to prevent contrast-induced nephropathy still remains an unresolved issue. Former meta-analyses and several recent studies have shown conflicting results regarding the protective effect of sodium bicarbonate. The objective of this study was to assess the effectiveness of normal saline versus sodium bicarbonate for prevention of contrast-induced nephropathy. Methods The study searched MEDLINE, EMBASE, Cochrane databases, International Pharmaceutical Abstracts database, ISI Web of Science (until 15 December 2008, and conference proceedings for randomized controlled trials that compared normal saline with sodium bicarbonate-based hydration regimen regarding contrast-induced nephropathy. Random-effects models were used to calculate summary odds ratios. Results A total of 17 trials including 2,633 subjects were pooled. Pre-procedural hydration with sodium bicarbonate was associated with a significant decrease in the rate of contrast-induced nephropathy (odds ratios 0.52; 95% confidence interval 0.34–0.80, P = 0.003. Number needed to treat to prevent one case of contrast-induced nephropathy was 16 (95% confidence interval 10–34. No significant differences in the rates of post-procedure hemodialysis (P = 0.20 or death (P = 0.53 was observed. Conclusion Sodium bicarbonate-based hydration was found to be superior to normal saline in prevention of contrast-induced nephropathy in this updated meta-analysis.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-04-01

    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.

  12. Prevention of contrast induced nephropathy with sodium bicarbonate (the PROMEC study

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    John Fredy Nieto-Ríos

    2014-09-01

    Full Text Available Introduction: Contrast-induced nephropathy is a common complication of radiographic procedures. Different measures have been used to avoid this damage, but the evidence is controversial. New investigations are required to clarify it. We investigated the efficacy and safety of sodium bicarbonate solution compared with sodium chloride solution to prevent contrast induced nephropathy in patients with or at risk of renal dysfunction. Methods: A prospective, single-center, randomized clinical trial conducted from May 1, 2007 to February 8, 2008. Inpatients in a tertiary center, scheduled to undergo a procedure with the nonionic radiographic contrast agent iohexol. There were 220 patients with serum creatinine levels of at least 1.2 mg/dL (106.1 µmol/L and/or type 2 diabetics, who were randomized to receive an infusion of sodium chloride (n = 113 or sodium bicarbonate (n = 107 before and after contrast dye administration. The intervention were "A" group received 1 ml/kg/hour of normal saline solution, starting 12 hours before and continuing 12 hours after iohexol contrast. "B" group received 3 ml/kg of sodium bicarbonate solution (150 mEq/L one hour prior to procedure and then drip rate was decreased to 1 ml/kg/hour until 6 hours post procedure. Our main outcome measure was change in serum creatinine. Results: The mean creatinine value after the procedure was 1.26 mg/dL in the saline group and 1.22 mg/dL in the bicarbonate group (mean difference: 0.036; CI 95%: -0.16 to 0.23, p = 0.865. The diagnosis of contrast-induced nephropathy, defined by increase in serum creatinine on 25% or more within 2 days after administration of radiographic contrast, was done in twelve patients (12% in the bicarbonate group and eighth patients (7.1% in the saline group (RR: 1.68, CI 95%: 0.72 to 3.94. Conclusion: Our investigation showed that there were no differences between normal saline solution (extended infusion vs. bicarbonate solution for nephroprotection.

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

    Science.gov (United States)

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

    2012-01-01

    Introduction Lactic acidosis is a frequent cause of poor outcome in the intensive care settings. We set up an experimental model of lactic acid infusion in normoxic and normotensive rats to investigate the systemic effects of lactic acidemia per se without the confounding factor of an underlying organic cause of acidosis. Methodology Sprague Dawley rats underwent a primed endovenous infusion of L(+) lactic acid during general anesthesia. Normoxic and normotensive animals were then randomized to the following study groups (n = 8 per group): S) sustained infusion of lactic acid, S+B) sustained infusion+sodium bicarbonate, T) transient infusion, T+B transient infusion+sodium bicarbonate. Hemodynamic, respiratory and acid-base parameters were measured over time. Lactate pharmacokinetics and muscle phosphofructokinase enzyme's activity were also measured. Principal Findings Following lactic acid infusion blood lactate rose (P<0.05), pH (P<0.05) and strong ion difference (P<0.05) drop. Some rats developed hemodynamic instability during the primed infusion of lactic acid. In the normoxic and normotensive animals bicarbonate treatment normalized pH during sustained infusion of lactic acid (from 7.22±0.02 to 7.36±0.04, P<0.05) while overshoot to alkalemic values when the infusion was transient (from 7.24±0.01 to 7.53±0.03, P<0.05). When acid load was interrupted bicarbonate infusion affected lactate wash-out kinetics (P<0.05) so that blood lactate was higher (2.9±1 mmol/l vs. 1.0±0.2, P<0.05, group T vs. T+B respectively). The activity of phosphofructokinase enzyme was correlated with blood pH (R2 = 0.475, P<0.05). Conclusions pH decreased with acid infusion and rose with bicarbonate administration but the effects of bicarbonate infusion on pH differed under a persistent or transient acid load. Alkalization affected the rate of lactate disposal during the transient acid load. PMID:23029373

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

    Science.gov (United States)

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

    2011-12-01

    The aim of the present study was to examine the effect of sodium bicarbonate ingestion on consecutive "all out" sprint tests, analyzing the acid-base status and its influence on performance and perceived effort. Ten elite bicycle motocross (BMX) riders (20.7 ± 1.4 years, training experience 8-12 years) participated in this study which consisted of two trials. Each trial consisted of three consecutive Wingate tests (WTs) separated by 15 min recovery. Ninety minutes prior to exercise subjects ingested either NaHCO(3) (-) (0.3 g kg(-1) body weight) or placebo. Blood samples were collected for the assessment of blood acid-base status: bicarbonate concentration ([HCO(3) (-)]), pH, base excess (BE) and blood lactate concentration ([La(-)]). Performance variables of peak power (PP), mean power (MP), time to peak power and fatigue index were calculated for each sprint. Significant differences (p BMX cyclists.

  15. CRACK2. Modelling calcium carbonate deposition from bicarbonate solutions in cracks in concrete

    DEFF Research Database (Denmark)

    Brodersen, Knud Erik

    2003-01-01

    The numerical CRACK2 model simulates precipitation of calcite from calcium bicarbonate solution (e.g. groundwater) passing through cracks in concrete or other cementitious materials. A summary of experimental work is followed by a detailed description ofthe model. Hydroxyl ions are transported...... by diffusion in pore systems in columns of cementitious materials. The hydroxyl is precipitating calcite from a flow of bicarbonate solution in a crack connecting the ends of a row of such columns. Thecementitious material is simulated as calcium hydroxide mixed with inert material but with sodium hydroxide...... dissolved in the pore solution. Diffusive migration of cesium as radioactive isotope is also considered. Electrical interaction of the migratingions is taken into account. Example calculations demonstrate effects of parameter variations on distribution of precipitated calcite in the crack...

  16. Effect of bicarbonate supplementation on renal function and nutritional indices in predialysis advanced chronic kidney disease.

    Science.gov (United States)

    Jeong, Jiwon; Kwon, Soon Kil; Kim, Hye-Young

    2014-12-01

    Current practice guidelines recommend alkali therapy in patients with chronic kidney disease (CKD) and metabolic acidosis to prevent complications. This study aims to investigate the effect of oral sodium bicarbonate supplementation on the progression of renal function and nutritional indices in patients with predialysis advanced CKD. Forty patients with predialysis stage 5 CKD(estimated glomerular filtration rate, eGFR total lymphocyte count (TLC), and Ondodera's prognostic nutritional index (OPNI) during the study between the two groups. In stage 5 CKD, there were significant differences in the changes of TLC and OPNI between the two groups. In conclusion, our results demonstrate that bicarbonate supplementation slows the rate of decline of renal function in stage 4 CKD and improves nutritional indices in stage 5 CKD. Alkali therapy in advanced CKD may have beneficial effect on renal function and malnutrition.

  17. Transformation of Sodium Bicarbonate and CO2 into Sodium Formate over NiPd Nanoparticle Catalyst

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    Mengnan eWang

    2013-09-01

    Full Text Available 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.

  18. Caffeine, but not bicarbonate, improves 6 min maximal performance in elite rowers

    DEFF Research Database (Denmark)

    Christensen, Peter Møller; Petersen, Mads H; Friis, Signe N;

    2014-01-01

    This study examined the ergogenic effects in a 6 min maximal performance test (PT) on 12 elite rowers: 6 open-weight (mean ± SD; 25 ± 1 years, and 92 ± 3 kg) and 6 light-weight (25 ± 3 years, and 73 ± 6 kg), following supplementation with caffeine (CAF), sodium bicarbonate (SB), and the combination.......05) than in open-weight rowers (0.3% ± 0.8%; P > 0.05). No difference between interventions was observed for readiness and stomach comfort before PT and perceived exertion during PT. This study demonstrates that caffeine ingestion does improve performance in elite rowing. In contrast sodium bicarbonate...... does not appear to be ergogenic, but it does not abolish the ergogenic effect of caffeine....

  19. Temperature and Particle Size Dependence of Sodium Bicarbonate Inhibition of Methane/Air Flames.

    Science.gov (United States)

    1982-11-03

    43 7 Particle mess flow rate in fluidized bed feeder as a function of pressure drop in mercury manometer . . 46 8 Attenuated Us~e laser peak upon... mercury manometer , attached to the fluidized feeder housing, was used to find the value of mass flow rate on the calibration curve. Sodium bicarbonate was...front without further refinement. 45 3.2 Particle Feed Rate Measurements LI A mercury manometer was attached to the fluidized feeder housing and a

  20. SODIUM BICARBONATE INFUSION: TO PREVENT CARDIAC SURGERY - ASSOCIATED ACUTE KIDNEY INJURY

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    Ramesh

    2015-02-01

    Full Text Available OBJECTIVES: The incidence of cardiac surgery – associated acute kidney injury is 50% of patients and is associated with increased mortality and morbidity. This study aimed to determine if perioperative urinary and plasma alkalization with sodium bicarbonate infusion re duces the incidence of cardiac surgery – associated acute kidney injury. SETTING AND DESIGN: This study is double blind randomized control trial conducted at U N Mehta Institute of Cardiology and Research Center , India. METHOD S AND RESULT: A total of 140 pat ients scheduled to undergo elective cardiac surgery , who were at increased risk of development of cardiac surgery – associated acute kidney injury using recognized risk factors. Patients were randomly allocated to receive either sodium bicarbonate (n = 70 o r sodium chloride (n = 70 infusion , commencing at the start of anesthesia , in a dose of 4 mmol/kg over 24 hour. The primary outcome measure was the number of patients with development of CSA - AKI , defined as an increase in creatinine greater than 25% from baseline to peak value within the first three postoperative days. Significant differences among the groups in both plasma and urinary pH were achieved 6 hours after commencement of the infusion , and these changes persisted for more than 24 hours. A total o f 7 out of 70(10% patients in the sodium bicarbonate group and 16 out of 70(22.85% patients in the sodium chloride group developed acute kidney injury within the first three postoperative days with p value of 0.06 which is statistically not significant . There were also no significant differences in ventilation hours , ICU or hospital length of stay , or mortality. CONCLUSIONS: Perioperative alkalization of blood and urine using an infusion of sodium bicarbonate did not result in a decrease in the incidence of acute kidney injury in patients undergoing cardiac surgery. KEYWORDS: Acute kidney injury; Cardiac surgery; Cardiopulmonary bypass; Creatinine

  1. Bicarbonate-responsive “soluble” adenylyl cyclase defines a nuclear cAMP microdomain

    Science.gov (United States)

    Zippin, Jonathan H.; Farrell, Jeanne; Huron, David; Kamenetsky, Margarita; Hess, Kenneth C.; Fischman, Donald A.; Levin, Lonny R.; Buck, Jochen

    2004-01-01

    Bicarbonate-responsive “soluble” adenylyl cyclase resides, in part, inside the mammalian cell nucleus where it stimulates the activity of nuclear protein kinase A to phosphorylate the cAMP response element binding protein (CREB). The existence of this complete and functional, nuclear-localized cAMP pathway establishes that cAMP signals in intracellular microdomains and identifies an alternate pathway leading to CREB activation. PMID:14769862

  2. Bicarbonate-responsive “soluble” adenylyl cyclase defines a nuclear cAMP microdomain

    OpenAIRE

    2004-01-01

    Bicarbonate-responsive “soluble” adenylyl cyclase resides, in part, inside the mammalian cell nucleus where it stimulates the activity of nuclear protein kinase A to phosphorylate the cAMP response element binding protein (CREB). The existence of this complete and functional, nuclear-localized cAMP pathway establishes that cAMP signals in intracellular microdomains and identifies an alternate pathway leading to CREB activation.

  3. Ammonium Bicarbonate Transport in Anion Exchange Membranes for Salinity Gradient Energy

    KAUST Repository

    Geise, Geoffrey M.

    2013-09-17

    Many salinity gradient energy technologies such as reverse electrodialysis (RED) rely on highly selective anion transport through polymeric anion exchange membranes. While there is considerable interest in using thermolytic solutions such as ammonium bicarbonate (AmB) in RED processes for closed-loop conversion of heat energy to electricity, little is known about membrane performance in this electrolyte. The resistances of two commercially available cation exchange membranes in AmB were lower than their resistances in NaCl. However, the resistances of commercially available anion exchange membranes (AEMs) were much larger in AmB than in NaCl, which would adversely affect energy recovery. The properties of a series of quaternary ammonium-functionalized poly(phenylene oxide) and Radel-based AEMs were therefore examined to understand the reasons for increased resistance in AmB to overcome this performance penalty due to the lower mobility of bicarbonate, 4.59 × 10-4 cm2/(V s), compared to chloride, 7.90 × 10-4 cm2/(V s) (the dilute aqueous solution mobility ratio of HCO3 - to Cl- is 0.58). Most membrane resistances were generally consistent with the dilute solution mobilities of the anions. For a few key samples, however, increased water uptake in AmB solution reduced the ionic resistance of the polymer compared to its resistance in NaCl solution. This increased water uptake was attributed to the greater hydration of the bicarbonate ion compared to the chloride ion. The increased resistance due to the use of bicarbonate as opposed to chloride ions in AEMs can therefore be mitigated by designing polymers that swell more in AmB compared to NaCl solutions, enabling more efficient energy recovery using AmB thermolytic solutions in RED. © 2013 American Chemical Society.

  4. Influence of colostrum preservation and sodium bicarbonate on performance of dairy calves.

    Science.gov (United States)

    Jenny, B F; Hodge, S E; O'Dell, G D; Ellers, J E

    1984-02-01

    Forty-eight Holstein calves were fed one of four liquid diets from 3 to 30 days of age to compare sodium benzoate, propionic acid, and formaldehyde as preservatives for colostrum. Colostrum batches were fermented at temperatures of 20 degrees C or higher. Diets were 2.73 kg of 1) naturally fermented colostrum, or colostrum treated with 2) sodium benzoate (.5% by weight), 3) propionic acid (1.0% by weight), or 4) formaldehyde (.05% by weight). Colostrum diets were diluted with .91 kg water. Prior to feeding, 25 g. sodium bicarbonate was added to liquid diets of one-half the calves on each treatment. Liquid diets were fed once daily. Water and a 15% crude protein complete starter were offered for ad libitum consumption. Calves were weaned abruptly at 30 days of age and received only water and starter from 31 to 44 days of age. Daily gain from 0 to 4 wk and 0 to 6 wk favored calves fed colostrum treated with sodium benzoate or propionic acid. Gains from 0 to 6 wk were .33, .44, .45, and .32 kg/day for the four diets, and feed efficiencies (kg dry matter intake/kg gain) were 3.23, 2.36, 2.76, and 2.89 during the same period. Addition of sodium bicarbonate to colostrum diets improved intake during the 1st wk of feeding. Gain and feed efficiency were similar during wk 0 to 4 but favored slightly calves not receiving sodium bicarbonate during the overall study, wk 0 to 6. Daily gain and efficiencies during wk 0 to 6 were .41 and 2.53 for calves without .36 and 3.01 with sodium bicarbonate added to colostrum diets.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Interactions between bicarbonate, potassium, and magnesium, and sulfur-dependent induction of luminescence in Vibrio fischeri.

    Science.gov (United States)

    Tabei, Yosuke; Era, Mariko; Ogawa, Akane; Morita, Hiroshi

    2012-06-01

    In spite of its central importance in research efforts, the relationship between seawater compounds and bacterial luminescence has not previously been investigated in detail. Thus, in this study, we investigated the effect of cations (Na(+) , K(+) , NH(4) (+) , Mg(2+) , and Ca(2+) ) and anions (Cl(-) , HCO(3) (-) , CO(3) (2-) , and NO(3) (-) ) on the induction of both inorganic (sulfate, sulfite, and thiosulfate) and organic (L-cysteine and L-cystine) sulfur-dependent luminescence in Vibrio fischeri. We found that HCO(3) (-) (bicarbonate) and CO(3) (2-) (carbonate), in the form of various compounds, had a stimulatory effect on sulfur-dependent luminescence. The luminescence induced by bicarbonate was further promoted by the addition of magnesium. Potassium also increased sulfur-dependent luminescence when sulfate or thiosulfate was supplied as the sole sulfur source, but not when sulfite, L-cysteine, or L-cystine was supplied. The positive effect of potassium was accelerated by the addition of magnesium and/or calcium. Furthermore, the additional supply of magnesium improved the induction of sulfite- or L-cysteine-dependent luminescence, but not the l-cystine-dependent type. These results suggest that sulfur-dependent luminescence of V. fischeri under nutrient-starved conditions is mainly controlled by bicarbonate, carbonate, and potassium. In addition, our results indicate that an additional supply of magnesium is effective for increasing V. fischeri luminescence.

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

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    Thomas Stöggl

    2014-01-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2013-04-01

    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.

  8. Characterization of basolateral chloride/bicarbonate exchange in macula densa cells.

    Science.gov (United States)

    Komlosi, Peter; Frische, Sebastian; Fuson, Amanda L; Fintha, Attila; Zsembery, Akos; Peti-Peterdi, Janos; Bell, P Darwin

    2005-02-01

    Functional and immunohistological studies were performed to identify basolateral chloride/bicarbonate exchange in macula densa cells. Using the isolated, perfused thick ascending limb with attached glomerulus preparation dissected from rabbit kidney, macula densa intracellular pH (pH(i)) was measured with fluorescence microscopy and BCECF. For these experiments, basolateral chloride was reduced, resulting in reversible macula densa cell alkalinization. Anion exchange activity was assessed by measuring the maximal net base efflux on readdition of bath chloride. Anion exchange activity required the presence of bicarbonate, was independent of changes in membrane potential, did not require the presence of sodium, and was inhibited by high concentrations of DIDS. Inhibition of macula densa anion exchange activity by basolateral DIDS increased luminal NaCl concentration-induced elevations in pH(i). Immunohistochemical studies using antibodies against AE2 demonstrated expression of AE2 along the basolateral membrane of macula densa cells of rabbit kidney. These results suggest that macula densa cells functionally and immunologically express a chloride/bicarbonate exchanger at the basolateral membrane. This transporter likely participates in the regulation of pH(i) and might be involved in macula densa signaling.

  9. Gastric bicarbonate secretion, acid secretion, and mucosal blood flow during influence of pentagastrin and omeprazole in the cat.

    Science.gov (United States)

    Guttu, K; Røsok, B; Gislason, H; Fändriks, L; Svanes, K; Grønbech, J E

    1991-04-01

    In this study secretion of bicarbonate and acid and mucosal blood flow were determined simultaneously in cats. The gastric lumen of anesthetized cats was continuously perfused with isotonic saline. Secretion of HCO-3 and H+ was calculated from continuous measurements of pH and PCO2 in the perfusate. Mucosal blood was measured by means of radiolabeled microspheres. Under resting acid secretory conditions, bicarbonate secretion into the gastric lumen averaged 1.0 mumol/min. Somewhat surprising, both omeprazole (4 mg/kg as bolus) and pentagastrin (16 micrograms/kg.h intravenously) significantly reduced the HCO-3 secretion. Omeprazole did not influence mucosal blood flow, whereas corpus mucosal blood flow increased during pentagastrin stimulation. Under resting acid secretory conditions and during omeprazole treatment there was a close linear relationship between acid and bicarbonate secretion. No such relationship was found during pentagastrin stimulation of the mucosa. No consistent relationship was obtained between blood flow and bicarbonate secretion in normal gastric mucosa.

  10. Effects of Bicarbonate and High pH Conditions on Zinc and Other Nutrients Absorption in Rice

    Institute of Scientific and Technical Information of China (English)

    LU Zhong-xian; MENG Fan-hua; S. VILLAREAL; WEI You-zhang; YU Xiao-ping; YANG Xiao-e; K. L. HEONG; LIN Jian-jun; HU Cui; LIU Jian-xiang

    2004-01-01

    Zinc deficiency was widely observed in calcareous soil where bicarbonate and high pH were always related with low zinc availability. In a hydroponic experiment, one zinc-efficient rice (IR36) and one zinc-inefficient rice (IR26) genotypes were employed to investigate the effects of bicarbonate and high pH conditions on absorption, transport of zinc and other nutrients (P, K, Ca, Mg,Fe, Cu, Mn) in rice. As compared with the control, high pH inhibited absorption, translocation and accumulation of zinc and other nutrients in both rice genotypes. Bicarbonate had minor effect on zinc-efficient rice genotype (IR36) whereas it could decrease zinc and other nutrient absorption in zinc-inefficient rice genotype (IR26). These results implied that increasing rice tolerance to bicarbonate is one of the most important strategies to improve rice adaptation for zinc-deficit calcareous soil.

  11. Metabolic attributes, yield and stability of milk in Jersey cows fed diets containing sodium citrate and sodium bicarbonate

    OpenAIRE

    2013-01-01

    The objective of this work was to evaluate the inclusion of sodium citrate and sodium bicarbonate in the diet of lactating Jersey cows, and its effects on the metabolic attributes, productivity and stability of milk. We evaluated urinary pH, levels of glucose and urea in blood, body weight, body condition score, milk yield, milk stability (ethanol test), and milk physicochemical properties of 17 cows fed diets containing sodium citrate (100 g per cow per day), sodium bicarbonate (40 g per cow...

  12. Ergogenic effects of caffeine and sodium bicarbonate supplementation on intermittent exercise performance preceded by intense arm cranking exercise

    OpenAIRE

    Marriott, Matthaus; Krustrup, Peter; Mohr, Magni

    2015-01-01

    BACKGROUND: Caffeine and sodium bicarbonate ingestion have been suggested to improve high-intensity intermittent exercise, but it is unclear if these ergogenic substances affect performance under provoked metabolic acidification. To study the effects of caffeine and sodium bicarbonate on intense intermittent exercise performance and metabolic markers under exercise-induced acidification, intense arm-cranking exercise was performed prior to intense intermittent running after intake of placebo,...

  13. Na/K citrate versus sodium bicarbonate in prevention of contrast-induced nephropathy.

    Science.gov (United States)

    Abouzeid, Sameh Mohamed; ElHossary, Hossam E

    2016-05-01

    Contrast-induced nephropathy (CIN) is one of the important complications of radiographic procedures, especially in patients with chronic kidney disease. It is also one of the common causes of acute kidney injury. The pathogenesis is postulated to be the effect of oxygen- free radicals and hyperosmolar stress on the renal medulla. It is reported that the production of superoxide is most active at acid environment. K/Na citrate is well known as a urine alkalinization medium, and this has been evaluated earlier with standard hydration for reduction of CIN and was stated to be efficient. We aimed to determine the efficacy of Na/K citrate in reducing the frequency of CIN in comparison to sodium bicarbonate in patients after coronary angiography. Two hundred and ten patients with renal dysfunction [estimated glomerular filtration rate (eGFR), 60 mL/min/1.73 m(2) or less] who underwent elective or emergency coronary angiography (CAG) with/without percutaneous coronary intervention (PCI) at our institution were enrolled into the study. The patients were randomized into two groups, Group 1-Taking Na/K citrate and Group 2-Taking sodium bicarbonate. Radiographic contrast agent iohexol was used. Change in creatinine, percent change in creatinine, percent change in eGFR, change in serum potassium, and urine pH were all compared between the two groups. There was no significant difference for prevention of CIN when comparing the Na/K citrate with sodium bicarbonate solution in patients exposed to CAG with or without PCI. Mean absolute change in eGFR after 48 h after administration of contrast between sodium bicarbonate group and Na/K citrate group was -0.60 ± 1.58 versus -0.71 ± 1.38. Serum potassium decreased postprocedure in the sodium bicarbonate group than in the citrate group (3.90 ± 0.33 vs. 4.14 ± 0.39). Both agents are equally effective in reducing the incidence of CIN, but the citrate would possibly be a safer option for patients at risk of hypokalemia.

  14. Specific and efficient targeting of cyanobacterial bicarbonate transporters to the inner envelope membrane of chloroplasts in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Susumu eUehara

    2016-02-01

    Full Text Available Installation of cyanobacterial bicarbonate transporters to the inner envelope membrane (IEM of chloroplasts in C3 plants has been thought to improve photosynthetic performance. However, the method to deliver cyanobacterial bicarbonate transporters to the chloroplast IEM remains to be established. In this study, we provide evidence that the cyanobacterial bicarbonate transporters, BicA and SbtA, can be specifically installed into the chloroplast IEM using the chloroplast IEM targeting signal in conjunction with the transit peptide. We fused the transit peptide and the mature portion of Cor413im1, whose targeting mechanism to the IEM has been characterized in detail, to either BicA or SbtA isolated from Synechocystis sp. PCC6803. Among the seven chimeric constructs tested, we confirmed that four chimeric bicarbonate transporters, designated as BicAI, BicAII, SbtAII, and SbtAIII, were expressed in Arabidopsis. Furthermore, these chimeric transporters were specifically targeted to the chloroplast IEM. They were also resistant to alkaline extraction but can be solubilized by Triton X-100, indicating that they are integral membrane proteins in the chloroplast IEM. One of the transporters, BicA, could reside in the chloroplast IEM even after removal of the IEM targeting signal. Taken together, our results indicate that the addition of IEM targeting signal, as well as the transit peptide, to bicarbonate transporters allows us to efficiently target nuclear-encoded chimeric bicarbonate transporters to the chloroplast IEM.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-02

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

  16. Biosynthesis of the proteasome inhibitor syringolin A: the ureido group joining two amino acids originates from bicarbonate

    Directory of Open Access Journals (Sweden)

    Schellenberg Barbara

    2009-10-01

    Full Text Available Abstract Background Syringolin A, an important virulence factor in the interaction of the phytopathogenic bacterium Pseudomonas syringae pv. syringae B728a with its host plant Phaseolus vulgaris (bean, was recently shown to irreversibly inhibit eukaryotic proteasomes by a novel mechanism. Syringolin A is synthesized by a mixed non-ribosomal peptide synthetase/polyketide synthetase and consists of a tripeptide part including a twelve-membered ring with an N-terminal valine that is joined to a second valine via a very unusual ureido group. Analysis of sequence and architecture of the syringolin A synthetase gene cluster with the five open reading frames sylA-sylE allowed to formulate a biosynthesis model that explained all structural features of the tripeptide part of syringolin A but left the biosynthesis of the unusual ureido group unaccounted for. Results We have cloned a 22 kb genomic fragment containing the sylA-sylE gene cluster but no other complete gene into the broad host range cosmid pLAFR3. Transfer of the recombinant cosmid into Pseudomonas putida and P. syringae pv. syringae SM was sufficient to direct the biosynthesis of bona fide syringolin A in these heterologous organisms whose genomes do not contain homologous genes. NMR analysis of syringolin A isolated from cultures grown in the presence of NaH13CO3 revealed preferential 13C-labeling at the ureido carbonyl position. Conclusion The results show that no additional syringolin A-specific genes were needed for the biosynthesis of the enigmatic ureido group joining two amino acids. They reveal the source of the ureido carbonyl group to be bicarbonate/carbon dioxide, which we hypothesize is incorporated by carbamylation of valine mediated by the sylC gene product(s. A similar mechanism may also play a role in the biosynthesis of other ureido-group-containing NRPS products known largely from cyanobacteria.

  17. Association between Low Serum Bicarbonate Concentrations and Cardiovascular Disease in Patients in the End-Stage of Renal Disease

    Directory of Open Access Journals (Sweden)

    Vaia D. Raikou

    2016-11-01

    Full Text Available Background: Metabolic acidosis, a common condition particularly in the end-stage of renal disease patients, results in malnutrition, inflammation and oxidative stress. In this study, we focused on the association between low serum bicarbonate and cardiovascular disease in patients on intermittent dialysis. Methods: We studied 52 on-line-pre-dilution hemodiafiltration (on-l HDF patients, 32 males and 20 females, with a mean age of 58.01 ± 15.4 years old. Metabolic acidosis was determined by serum bicarbonate concentrations less than 22 mmol/L. Residual renal function (RRF was defined by interdialytic urine volume. Kaplan–Meier curves and Cox regression models were performed to predict coronary artery disease (CAD, defined by ejection fraction <50%, or diastolic dysfunction congestive heart failure (CHF and peripheral vascular disease (PVD. Results: Kaplan–Meier analyses showed that a lower or higher than 22 mmol/L serum bicarbonate metabolic acidosis status was significantly associated with both PVD and diastolic dysfunction (log-rank = 5.07, p = 0.02 and log-rank = 5.84, p = 0.01, respectively. A similar prevalence of serum bicarbonate on CAD or CHF by low ejection fraction was not shown. The RRF was associated with PVD event and serum bicarbonate less than 22 mmol/L (log-rank = 5.49, p = 0.01 and log-rank = 3.9, p = 0.04, respectively. Cox regression analysis revealed that serum bicarbonate and RRF were significant risk factors for PVD after adjustment for confounders. Furthermore, RRF adjusted for covariates was shown to be a significant risk factor for diastolic dysfunction. Conclusion: Low serum bicarbonate was associated with peripheral vascular disease and diastolic dysfunction in intermittent dialysis. The residual renal function may impact patients’ outcomes through its relationship with metabolic acidosis status, particularly for peripheral vascular disease manifestation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-05

    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.

  19. Addition of sodium bicarbonate to rations of pre- and postpartum dairy cows.

    Science.gov (United States)

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

    1980-12-01

    Sodium bicarbonate was added to complete mixed rations to evaluate the effect of buffer addition on adaptation to high-energy rations by dairy cows in elderly lactation. Forty-five Holstein cows were assigned to one of three treatment groups: control pre- and postpartum; control prepartum, buffer postpartum; and buffer pre- and postpartum. Rations consisted of 85% chopped grass hay: 15% concentrate prepartum and 60% corn silage:40% concentrate postpartum. On day 4 postpartum, cows were switched abruptly to the postpartum ration for 9 wk. Buffered rations contained .6% sodium bicarbonate prepartum and .7% postpartum. Daily dry matter intake as a percent of body weight for cows fed buffer postpartum (3.51%) was greater than for cows fed no buffer (3.04%) of buffer pre- and postpartum (3.14%). Average production of 4% fat-corrected milk was greater for cows fed buffer postpartum and buffer pre- and postpartum (31.9 kg/day and 31.7 kg/day) than for cows fed no buffer (28.9 kg/day). Milk fat tests were not different. Cows fed the buffered rations lost body weight between wk 1 and 9 as compared to a net gain for cows fed no buffer. Cows fed buffers consumed more dry matter during wk 1 than did cows fed no buffer. Samples of rumen fluid, feces, and serum showed few differences that could be attributed to treatments. Compared to controls, cows fed sodium bicarbonate adapted to rations more rapidly postpartum as indicated by increased feed intake during the first 2 wk and by increased milk production during the first 4 wk of the trial.

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

    Science.gov (United States)

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

    2013-01-01

    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.

  1. Water absorption and bicarbonate secretion in the intestine of the sea bream are regulated by transmembrane and soluble adenylyl cyclase stimulation.

    Science.gov (United States)

    Carvalho, Edison S M; Gregório, Sílvia F; Power, Deborah M; Canário, Adelino V M; Fuentes, Juan

    2012-12-01

    In the marine fish intestine luminal, HCO₃⁻ can remove divalent ions (calcium and magnesium) by precipitation in the form of carbonate aggregates. The process of epithelial HCO₃⁻ secretion is under endocrine control, therefore, in this study we aimed to characterize the involvement of transmembrane (tmACs) and soluble (sACs) adenylyl cyclases on the regulation of bicarbonate secretion (BCS) and water absorption in the intestine of the sea bream (Sparus aurata). We observed that all sections of sea bream intestine are able to secrete bicarbonate as measured by pH-Stat in Ussing chambers. In addition, gut sac preparations reveal net water absorption in all segments of the intestine, with significantly higher absorption rates in the anterior intestine that in the rectum. BCS and water absorption are positively correlated in all regions of the sea bream intestinal tract. Furthermore, stimulation of tmACs (10 μM FK + 500 μM IBMX) causes a significant decrease in BCS, bulk water absorption and short circuit current (Isc) in a region dependent manner. In turn, stimulation of sACs with elevated HCO₃⁻ results in a significant increase in BCS, and bulk water absorption in the anterior intestine, an action completely reversed by the sAC inhibitor KH7 (200 μM). Overall, the results reveal a functional relationship between BCS and water absorption in marine fish intestine and modulation by tmACs and sAC. In light of the present observations, it is hypothesized that the endocrine effects on intestinal BCS and water absorption mediated by tmACs are locally and reciprocally modulated by the action of sACs in the fish enterocyte, thus fine-tuning the process of carbonate aggregate production in the intestinal lumen.

  2. [ROLES OF CONSTITUTIVE SYNTHASES OF NITRIC OXIDE IN THE REGULATION OF GASTRIC BICARBONATE SECRETION INDUCED BY MILD IRRITATION OF THE MUCOSA].

    Science.gov (United States)

    Zolotarev, V A; Andreeva, Yu V; Vershinina, E A; Kropycheva, R P

    2015-04-01

    Roles of isoforms of constitutive synthase of nitric oxide, neuronal or endothelial (nNOS or eNOS), in control of gastric bicarbonate secretion induced by mild irritation of the gastric mucosa was assessed at the normoacid state or after blockade of gastric acid secretion with omeprazole. In anesthetized rats, the concentration of HCO3- in luminal perfusate was calculated basing on measurements of pH/PCO2. Mucosal irritation during 20 min with acidic hypertonic solution (1 M NaCl, pH 2.0) caused marked and omeprazole-independent increase of HCO-secretion. Selective blocker ofnNOS in vivo 7-nitroindazole (7-NI), and the nonselective blocker ofnNOS and eNOS, N(G)-nitro-L-arginine (L-NNA), were applied either intravenously (10 mg/kg), or locally via retrograde injection into the splenic artery (1 mg/kg). At the normo-acid state, the irritation-induced secretion of was suppressed by 7-NI, but was not affected by L-NNA. After administration of omeprazole, both 7-NI and L-NNA equally inhibited HCO3- output. The effect of 7-NI (but not L-NNA) was abolished by cyclooxygenase (COX) inhibitor, indomethacin, which by itself suppressed irritation-induced secretion of HCO3-. Additionally, bicarbonate output was substantially reduced by the blocker of soluble guanylate cyclase (GC), methylene blue. We conclude that irritation-induced secretion of HCO3- is largely mediated by intramural nNOS and depends on GC-COX interaction. As it was theoretically estimated, eNOS activity caused a reduction of HCO3- output in the normo-acid stomach. Omeprazole abolished the effect of eNOS.

  3. Nitric oxide content is associated with tolerance to bicarbonate-induced chlorosis in micropropagated Prunus explants.

    Science.gov (United States)

    Cellini, Antonio; Corpas, Francisco Javier; Barroso, Juan Bautista; Masia, Andrea

    2011-09-01

    Iron (Fe) chlorosis is a common nutritional deficiency in fruit trees grown in calcareous soils. Grafting on tolerant rootstocks is the most efficient practice to cope with it. In the present work, three Prunus hybrid genotypes, commonly used as peach rootstocks, and one peach cultivar were cultivated with bicarbonate in the growth medium. Parameters describing oxidative stress and the metabolism of reactive nitrogen species were studied. Lower contents of nitric oxide and a decreased nitrosoglutathione reductase activity were found in the most sensitive genotypes, characterized by higher oxidative stress and reduced antioxidant defense. In the peach cultivar, which behaved as a tolerant genotype, a specifically nitrated polypeptide was found.

  4. High serum bicarbonate level within the normal range prevents the progression of chronic kidney disease in elderly chronic kidney disease patients

    Directory of Open Access Journals (Sweden)

    Kanda Eiichiro

    2013-01-01

    Full Text Available Abstract Background Metabolic acidosis leads to chronic kidney disease (CKD progression. The guidelines recommend a lower limit of serum bicarbonate level, but no upper limit. For serum bicarbonate level to be clinically useful as a therapeutic target marker, it is necessary to investigate the target serum bicarbonate level within the normal range to prevent CKD progression. Methods One hundred and thirteen elderly CKD patients, whose serum bicarbonate level was controlled within the normal range, were enrolled in this retrospective cohort study in Ibaraki, Japan. Outcome was defined as a decrease of 25% or more in estimated glomerular filtration rate (eGFR or starting dialysis. We used Cox proportional hazard models adjusted for patients’ characteristics to examine the association between serum bicarbonate level and the outcome. Results Female patients were 36.3%: average age (SD, 70.4 (6.6 years; eGFR, 25.7 (13.6 ml/min/1.73 m2; serum bicarbonate level, 27.4 (3.2 mEq/l. Patients with the lowest quartile of serum bicarbonate levels [23.4 (1.8 mEq/l] showed a high risk of CKD progression compared with patients with high serum bicarbonate levels [28.8 (2.3 mEq/l]: adjusted hazard ratio (HR, 3.511 (95% CI, 1.342-9.186. A 1 mEq/l increase in serum bicarbonate level was associated with a low risk of CKD progression: adjusted HR, 0.791 [95% confidence interval (CI, 0.684-0.914]. Conclusions In elderly CKD patients, our findings suggest that serum bicarbonate level is independently associated with CKD progression, and that a high serum bicarbonate level is associated with a low risk of CKD progression. A high target serum bicarbonate level within the normal range may be effective for preventing CKD progression.

  5. Association between serum bicarbonate and pH with depression, cognition and sleep quality in hemodialysis patients.

    Science.gov (United States)

    Afsar, Baris; Elsurer, Rengin

    2015-07-01

    Metabolic acidosis is a common feature in chronic renal failure patients, worsening progressively as renal function declines. There are conflicting data in hemodialysis (HD) patients with regard to acidosis, alkalosis and mortality. In HD patients, cognitive impairment, depression, sleep disorders and impaired quality of life are very common. Besides, these conditions are related with increased morbidity and mortality. However, no previous study investigated the relationship between pH, venous bicarbonate and anion gap with depression, sleep problems and cognitive function in HD patients. In this study we investigated these relationships. In total, 65 HD patients were included. The demographic parameters and laboratory parameters including bicarbonate, pH and anion gap was measured for all patients. Depressive symptoms, sleep quality and cognitive function, were measured by Beck depression inventory, The Pittsburgh Sleep Quality Index and by Mini Mental State Examination, respectively. We found that, sleep quality but not cognitive function or depression was independently related with venous pH and bicarbonate. Anion gap has no independent relationship with sleep quality, cognitive function and depression. In conclusion, metabolic acidosis and bicarbonate levels were independently related with sleep quality in HD patients. However, there was no association between metabolic acidosis and bicarbonate levels with cognitive function and depression.

  6. Effect of vasoactive intestinal polypeptide and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1984-01-01

    The effect of VIP and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands was investigated in the rat. Vasoactive intestinal polypeptide infused in doses of 10 and 100 ng/kg/h significantly increased epidermal growth factor and bicarbonate output, but the co......The effect of VIP and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands was investigated in the rat. Vasoactive intestinal polypeptide infused in doses of 10 and 100 ng/kg/h significantly increased epidermal growth factor and bicarbonate output......, but the concentrations did not change. Somatostatin infused at doses of 1, 10, 100 and 1000 ng/kg/h against a background of VIP 100 ng/kg/h inhibited in dose-dependent fashion the stimulated epidermal growth factor and bicarbonate outputs from rat Brunner's gland pouches. Also basal secretion was inhibited...... by somatostatin. Infusion of antisomatostatin serum stimulated Brunner's gland secretion. By immunohistochemical studies of rat duodena, it was found that epidermal growth factor, is almost exclusively present in the secretory cells of Brunner's glands. It is concluded that VIP stimulates secretion of epidermal...

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

    Science.gov (United States)

    Xu, Aihua; Li, Xiaoxia; Xiong, Hui; Yin, Guochuan

    2011-02-01

    Bicarbonate anion is an efficient activator for hydrogen peroxide to generate many active oxygen species including peroxymonocarbonate (HCO(4)(-)), superoxide ion (O(2)(-)) and singlet oxygen ((1)O(2)). This study aims to understand the oxidative degradation of organic pollutants including methyl blue, methyl orange, rhodamine B, and 4-chlorophenol, with H(2)O(2) activated by sodium bicarbonate at room temperature. The obtained results indicate that such a method is apparently efficient in versatile pollutant degradation. Compared with using H(2)O(2) alone under similar pH conditions, the degradation rates of the pollutants were greatly enhanced through adding NaHCO(3). Through LC-MS, FT-IR and the TOC analysis, the degradation of methylene blue was revealed to proceed by the transformation of dimethylamino group in methylene blue to methylamino, aldehyde and nitro group, and the opening of phenyl ring into small molecular compounds and CO(2). The studies using the (1)O(2) scavenger sodium azide and the O(2)(-) indicator nitro blue tetrazolium suggest that the active O(2)(-) intermediate, generated from HCO(4)(-) decomposition, rather than (1)O(2) was involved in the pollutant degradation.

  8. Bicarbonate transporters in corals point towards a key step in the evolution of cnidarian calcification

    KAUST Repository

    Zoccola, Didier

    2015-06-04

    The bicarbonate ion (HCO3−) is involved in two major physiological processes in corals, biomineralization and photosynthesis, yet no molecular data on bicarbonate transporters are available. Here, we characterized plasma membrane-type HCO3− transporters in the scleractinian coral Stylophora pistillata. Eight solute carrier (SLC) genes were found in the genome: five homologs of mammalian-type SLC4 family members, and three of mammalian-type SLC26 family members. Using relative expression analysis and immunostaining, we analyzed the cellular distribution of these transporters and conducted phylogenetic analyses to determine the extent of conservation among cnidarian model organisms. Our data suggest that the SLC4γ isoform is specific to scleractinian corals and responsible for supplying HCO3− to the site of calcification. Taken together, SLC4γ appears to be one of the key genes for skeleton building in corals, which bears profound implications for our understanding of coral biomineralization and the evolution of scleractinian corals within cnidarians.

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

    Directory of Open Access Journals (Sweden)

    R. S. Pimenta

    2010-06-01

    Full Text Available 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.

  10. Caffeine, but not bicarbonate, improves 6 min maximal performance in elite rowers.

    Science.gov (United States)

    Christensen, Peter M; Petersen, Mads H; Friis, Signe N; Bangsbo, Jens

    2014-09-01

    This study examined the ergogenic effects in a 6 min maximal performance test (PT) on 12 elite rowers: 6 open-weight (mean ± SD; 25 ± 1 years, and 92 ± 3 kg) and 6 light-weight (25 ± 3 years, and 73 ± 6 kg), following supplementation with caffeine (CAF), sodium bicarbonate (SB), and the combination of both, in a double-blind randomized placebo (PLA) controlled design. PT was executed on 4 occasions, on separate days within a week, and in a non-fasted state, with standardized training being performed the day before PT. Protocols were as follows: (i) CAF, 3 mg/kg, 45 min prior to PT + calcium as SB-PLA; (ii) SB, 0.3 g/kg, 75 min prior to PT + dextrose as CAF-PLA; (iii) CAF + SB; and (iv) PLA; CAF-PLA + SB-PLA. The total distance in the CAF (1878 ± 97 m) and CAF + SB (1877 ± 97 m) was longer than in the PLA (1865 ± 104 m; P 0.05). No difference between interventions was observed for readiness and stomach comfort before PT and perceived exertion during PT. This study demonstrates that caffeine ingestion does improve performance in elite rowing. In contrast sodium bicarbonate does not appear to be ergogenic, but it does not abolish the ergogenic effect of caffeine.

  11. CRACK2 - Modelling calcium carbonate deposition from bicarbonate solution in cracks in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Brodersen, K

    2003-03-01

    The numerical CRACK2 model simulates precipitation of calcite from calcium bicarbonate solution (e.g. groundwater) passing through cracks in concrete or other cementitious materials. A summary of experimental work is followed by a detailed description of the model. Hydroxyl ions are transported by diffusion in pore systems in columns of cementitious materials. The hydroxyl is precipitating calcite from a flow of bicarbonate solution in a crack connecting the ends of a row of such columns. The cementitious material is simulated as calcium hydroxide mixed with inert material but with sodium hydroxide dissolved in the pore solution. Diffusive migration of cesium as radioactive isotope is also considered. Electrical interaction of the migrating ions is taken into account. Example calculations demonstrate effects of parameter variations on distribution of precipitated calcite in the crack and on the composition of the outflowing solution, which can be compared directly with experimental results. Leaching behavior of sodium can be used to tune the model to experimental observations. The calcite is mostly precipitated on top of the original crack surface and may under certain circumstances fill the crack. The produced thin layers of low porosity calcite act as a diffusion barrier limiting contact between cement and solution. Pore closure mechanisms in such layers are discussed. Implications for safety assessment of radioactive waste disposal are shortly mentioned. The model is also relevant for conventional uses of concrete. (au)

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

    Science.gov (United States)

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

    2010-01-01

    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

  13. Catalytic scavenging of peroxynitrite by lactoperoxidase in the absence and presence of bicarbonate.

    Science.gov (United States)

    Gebicka, Lidia; Didik, Joanna; Gebicki, Jerzy L

    2010-02-01

    The kinetics of the reaction of lactoperoxidase with peroxynitrite was studied under neutral and acidic pH. Lactoperoxidase catalyses peroxynitrite decay with the rate constant, k(c), increasing with decreasing pH. The values of k(c) obtained at pH 7.1, 6.1 and 5.1 are (1.9+/-0.1)x10(6), (5.0+/-0.1)x10(6) and (8.5+/-0.2)x10(6) M(-1)s(-1), respectively. This tendency means that peroxynitrous acid is the species involved in the reaction with the catalytic centre of lactoperoxidase. Lactoperoxidase is also able to scavenge peroxynitrite in the presence of bicarbonate with the rate constant identical, within experimental error, to that measured in the absence of bicarbonate. It is thus concluded that CO(3)-(.)/(.)NO(.2) radicals formed in the system do not inactivate LPO. The mechanism of the catalytic scavenging of peroxynitrite by LPO is proposed. The physiological relevance of this reaction is discussed.

  14. Effect of carbohydrate or sodium bicarbonate ingestion on performance during a validated basketball simulation test.

    Science.gov (United States)

    Afman, Gregg; Garside, Richard M; Dinan, Neal; Gant, Nicholas; Betts, James A; Williams, Clyde

    2014-12-01

    Current recommendations for nutritional interventions in basketball are largely extrapolated from laboratory-based studies that are not sport-specific. We therefore adapted and validated a basketball simulation test relative to competitive basketball games using well-trained basketball players (n = 10), then employed this test to evaluate the effects of two common preexercise nutritional interventions on basketball-specific physical and skilled performance. Specifically, in a randomized and counterbalanced order, participants ingested solutions providing either 75 g carbohydrate (sucrose) 45 min before exercise (Study A; n = 10) or 2 × 0.2 g · kg(-1) sodium bicarbonate (NaHCO3) 90 and 20 min before exercise (Study B; n = 7), each relative to appropriate placebos (H2O and 2 × 0.14 g · kg(-1) NaCl, respectively). Heart rate, sweat rate, pedometer count, and perceived exertion did not systematically differ between the 60-min basketball simulation test and competitive basketball, with a strong positive correlation in heart rate response (r = .9, p basketball simulation test provides a valid reflection of physiological demands in competitive basketball and is sufficiently sensitive to detect meaningful changes in physical and skilled performance. While there are benefits of preexercise carbohydrate or sodium bicarbonate ingestion, these should be balanced against potential negative side effects.

  15. Quantified pH imaging with hyperpolarized 13C‐bicarbonate

    DEFF Research Database (Denmark)

    Scholz, David Johannes; Janich, Martin A.; Köllisch, Ulrich

    2015-01-01

    Because pH plays a crucial role in several diseases, it is desirable to measure pH in vivo noninvasively and in a spatially localized manner. Spatial maps of pH were quantified in vitro, with a focus on method‐based errors, and applied in vivo. In vitro and in vivo 13C mapping were performed...... for various flip angles for bicarbonate (BiC) and CO2 with spectral‐spatial excitation and spiral readout in healthy Lewis rats in five slices. Acute subcutaneous sterile inflammation was induced with Concanavalin A in the right leg of Buffalo rats. pH and proton images were measured 2 h after induction....... After optimizing the signal to noise ratio of the hyperpolarized 13C‐bicarbonate, error estimation of the spectral‐spatial excited spectrum reveals that the method covers the biologically relevant pH range of 6 to 8 with low pH error (pH maps shows negligible impact...

  16. Metabolic attributes, yield and stability of milk in Jersey cows fed diets containing sodium citrate and sodium bicarbonate

    Directory of Open Access Journals (Sweden)

    Marcelo Tempel Stumpf

    2013-05-01

    Full Text Available The objective of this work was to evaluate the inclusion of sodium citrate and sodium bicarbonate in the diet of lactating Jersey cows, and its effects on the metabolic attributes, productivity and stability of milk. We evaluated urinary pH, levels of glucose and urea in blood, body weight, body condition score, milk yield, milk stability (ethanol test, and milk physicochemical properties of 17 cows fed diets containing sodium citrate (100 g per cow per day, sodium bicarbonate (40 g per cow per day or no additives. Assessments were made at the 28th and 44th days. Supply of sodium citrate or bicarbonate has no influence on the metabolic attributes, productivity, body weight, and body condition score of the cows, neither on the composition and stability of milk.

  17. Facile and Efficient Acetylation of Primary Alcohols and Phenols with Acetic Anhydride Catalyzed by Dried Sodium Bicarbonate

    Directory of Open Access Journals (Sweden)

    Fulgentius Nelson Lugemwa

    2013-12-01

    Full Text Available A variety of primary alcohols and phenols were reacted with acetic anhydride at room temperature in the presence of sodium bicarbonate to produce corresponding esters in good to excellent yields. The acetylation of 4-nitrobenzyl alcohol was also carried out using other bicarbonates and carbonates. The reaction in the presence of cesium bicarbonate and lithium carbonate gave 4-nitrobenzyl acetate in excellent yield, while in the presence of Na2CO3, K2CO3, Cs2CO3, or KHCO3 the yield was in the range of 80%–95%. Calcium carbonate and cobaltous carbonate did not promote the acetylation of 4-ntirobenzyl alcohol using acetic anhydride. The acetylation of 4-nitrobenzyl alcohol was carried out using ethyl acetate, THF, toluene, diethyl ether, dichloromethane and acetonitrile, and gave good yields ranging from 75%–99%. Toluene was the best solvent for the reaction, while diethyl ether was the poorest.

  18. Effect of Tris-Hydroxymethyl Aminomethane on intracellular pH depends on the extracellular non-bicarbonate buffering capacity.

    Science.gov (United States)

    Giunti, Carine; Priouzeau, Fabrice; Allemand, Denis; Levraut, Jacques

    2007-12-01

    The effect of Tris-Hydroxymethyl Aminomethane (THAM) on intracellular pH (pHi) is unknown. We previously demonstrated that the effect of sodium bicarbonate on pHi depends on the non-bicarbonate buffering system. First, human hepatocytes from hepatocytes cell culture (HepG2) were perfused with an acidotic artificial medium containing 5-mmol/L (H5) or 30-mmol/L (H30) concentrations of 4-(2-hydroxyethyl)-1-piperazineethane sulfonic acid (HEPES), a non-bicarbonate buffer. We studied the effect of THAM on the pHi in both conditions. We repeated the same protocol using an acidotic human blood with a 5% or 40% hematocrit. The pHi was measured with the pH-sensitive fluorescent dye bis-carboxyethyl carboxy-fluorescein (BCECF). Gas analysis was performed before and during the alkaline infusion. The results showed that THAM caused an intracellular alkalization that was higher when the non-bicarbonate buffer concentration was low (0.45 +/- 0.21 and 0.22 +/- 0.14 pH units with H5 and H30, respectively). A significant relationship was found between changes in pHi and changes in PCO(2). Similar results were obtained with the human blood. In conclusion, the intracellular alkalizing effect of THAM is caused by the induced decrease of PCO(2) linked to the extracellular non-bicarbonate buffer capacity: The smaller the concentration of extracellular non-bicarbonate buffer, the higher the PCO(2) decrease caused by THAM.

  19. Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

    Directory of Open Access Journals (Sweden)

    Wen Yicun

    2015-03-01

    Full Text Available The improved one-pot synthesis of dimethyl carbonate and propylene glycol from propylene oxide, supercritical carbon dioxide, and methanol with potassium bicarbonate as the catalyst has been reported in this paper. As far as we know, it is the first time to use potassium bicarbonate only as the catalyst in the production process which is simple and cheap. Satisfactory conversion rate of propylene oxide and yield of the products could be achieved at the optimized conditions with quite a small amount of by-products. Our new method offers an attractive choice for the production of dimethyl carbonate in large-scale industry efficiently and environmental friendly.

  20. Effect of Sodium bicarbonate on Fire behaviour of tilled E- Glass Reinforced Epoxy Composites

    Science.gov (United States)

    Girish, S.; Devendra, K.; Bharath, K. N.

    2016-09-01

    Composites such as fibre reinforced polymers give us the good mechanical properties, but their fire behaviour is not appreciable and needs to be improved. In this work, E- glass fiber is used as a reinforcement material and Epoxy resin is used as a matrix with particulate sodium bi-carbonate (NaHCO3) is used as additive. The hand lay-up technique is adopted for the development of composites by varying percentage of additive. All the tests were conducted according to ASTM standards to study the Fire behaviour of the developed composites. The different fire properties like Ignition time, mass loss rate and flame propagation rate of Fiber Reinforced Polymers (FRP) with NaHCO3 are compared with neat FRPs. It is found that the ignition time increases as the percentage of additive is increased.

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

    Science.gov (United States)

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

    2016-09-01

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

  2. [Hemodiafiltration with on-line production of bicarbonate infusate: 5 years of clinical experience].

    Science.gov (United States)

    Canaud, B; N'Guyen, Q V; Bouloux-Polito, C; Stec, F; Mion, C

    1992-01-01

    Despite its potential advantages HDF has not gained large clinical acceptance among nephrologist due to its technical complexity and to the large quantity of pharmaceutical substitution fluid needed. HDF with on-line production of substitution fluid from dialysate simplifies the procedure and reduces the cost of treatment session. We treated regularly 13 high risk and/or non-compliant patients (9 males, 4 females) with HDF for 46 +/- 17 months. HDF program consisted of 3 sessions weekly lasting 210 +/- 10 mn with blood flow rate 350 +/- 20 ml/mn and fluid volume exchange of 20 liters/session. High flux dialyzers (HF80, Filtral 16) were reused 6 to 13 times automatically on a Renatron machine with peroxyacetic acid solution as sole cleaning and disinfecting agent. Microbiologic quality of infusate was assessed by membrane filtration culturing method and LAL endotoxin determination. 3937 HDF sessions were performed. 57.140 I of substitution fluid were infused IV to patients. Eight pyrogenic reactions were observed: 2 due to septicemia related to catheter infection and 6 from unknown origin. Adequacy of program was achieved in all patients. Blood pressure control was satisfactorily obtained without antihypertensive medication in 12/13 patients. Effective weekly integrated urea clearances was 150 +/- 15 l/wk, KT/V index was 1.50 +/- 0.10, urea TAC 20 +/- 2 mM/l and protein catabolic rate 1.40 +/- 0.10 g/kg/24 h. We conclude that HDF with on-line production of bicarbonate substitution fluid is a safe and highly efficient method cost-competitive with bicarbonate HD, which offers an interesting alternative for renal replacement therapy.

  3. Identification of Bicarbonate as a Trigger and Genes Involved with Extracellular DNA Export in Mycobacterial Biofilms.

    Science.gov (United States)

    Rose, Sasha J; Bermudez, Luiz E

    2016-12-06

    Extracellular DNA (eDNA) is an integral biofilm matrix component of numerous pathogens, including nontuberculous mycobacteria (NTM). Cell lysis is the source of eDNA in certain bacteria, but the source of eDNA remains unidentified for NTM, as well as for other eDNA-containing bacterial species. In this study, conditions affecting eDNA export were examined, and genes involved with the eDNA export mechanism were identified. After a method for monitoring eDNA in real time in undisturbed biofilms was established, different conditions affecting eDNA were investigated. Bicarbonate positively influenced eDNA export in a pH-independent manner in Mycobacterium avium, M. abscessus, and M. chelonae The surface-exposed proteome of M. avium in eDNA-containing biofilms revealed abundant carbonic anhydrases. Chemical inhibition of carbonic anhydrases with ethoxzolamide significantly reduced eDNA export. An unbiased transposon mutant library screen for eDNA export in M. avium identified many severely eDNA-attenuated mutants, including one not expressing a unique FtsK/SpoIIIE-like DNA-transporting pore, two with inactivation of carbonic anhydrases, and nine with inactivation of genes belonging to a unique genomic region, as well as numerous mutants involved in metabolism and energy production. Complementation of nine mutants that included the FtsK/SpoIIIE and carbonic anhydrase significantly restored eDNA export. Interestingly, several attenuated eDNA mutants have mutations in genes encoding proteins that were found with the surface proteomics, and many more mutations are localized in operons potentially encoding surface proteins. Collectively, our data strengthen the evidence of eDNA export being an active mechanism that is activated by the bacterium responding to bicarbonate.

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

    Science.gov (United States)

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

    2013-12-01

    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.

  5. Chemical equilibrium of hydrogen and aqueous solutions of 1 : 1 bicarbonate and formate salts with a common cation

    NARCIS (Netherlands)

    Engel, D.C.; Versteeg, G.F.; Swaaij, W.P.M. van

    1997-01-01

    The chemical equilibrium of hydrogen and aqueous solutions of 1:1 bicarbonate and formate salts with a common cation has been investigated in an intensively stirred batch reactor: MHCO3(aq) + H2(aq) ↔ MOOCH(aq) + H2O(l) This was accomplished for the sodium (M = Na), potassium (M = K) and ammonium (M

  6. Effect of proton pump inhibitors on the secretion of bicarbonates and pepsinogen induced by chemical stimulation of the gastric mucosa.

    Science.gov (United States)

    Zolotarev, V A; Khropycheva, R P

    2013-02-01

    Proton pump inhibitors were shown to affect the sensitivity of the gastric mucosa to chemical agents. This effect is associated with inhibition of proton back-diffusion and increase in the permeability of the gastric epithelium. We studied the effect of omeprazole on gastric secretion of bicarbonates and pepsinogen induced by irritation of the gastric mucosa in narcotized rats with a hypertonic solution of high acidity (500 mM NaCl, pH 2.0). Irritation of the gastric mucosa increased the basal secretion of bicarbonates and potentiated the secretion of HCO3(-)and pepsinogen induced by electrostimulation of the vagus nerve. Omeprazole stimulated the prostaglandin-induced increase in the basal secretion of HCO3(-)and pepsinogen. By contrast, bicarbonate production in response to vagal stimulation was suppressed in the presence of omeprazole. Our results indicate that proton pump blockade has a modulatory effect on gastric secretion of bicarbonates and pepsinogen induced by chemical stimulation of the gastric mucosa.

  7. Bicarbonate utilization and pH polarity. The response of photosynthetic electron transport to carbon limitation in Potamogeton lucens leaves

    NARCIS (Netherlands)

    van Ginkel, LC; Prins, HBA

    1998-01-01

    By the process of pH polarity, several submersed angiosperms can use bicarbonate as carbon source for photosynthesis. Under conditions of relatively high light intensity and low CO2 availability, the pH of the apoplast and unstirred layer becomes acid at one side of the leaf and alkaline at the othe

  8. Evaluation of smear layer removal by bicarbonate soda, ethylenediamine tetraacetic acid with cetrimide and sodium hypochlorite with a new model.

    Science.gov (United States)

    Leow, Natalie; Abbott, Paul; Castro Salgado, Jacqueline; Firth, Laura

    2012-12-01

    Various methods are used to evaluate irrigants. The primary aim was to develop a model for preliminary testing of potential irrigants. The second aim was to investigate the effect of bicarbonate soda on smear layer by comparing it with ethylenediamine tetraacetic acid with cetrimide (EDTAC) and sodium hypochlorite (NaOCl). Extracted human single-canal teeth were halved, and a uniform filing method was used to create smear layer. The following solutions were then applied - distilled water (control), 1% NaOCl, 17% EDTAC and bicarbonate soda at concentrations of 1%, 5%, 10% and 15%. Some samples had multiple solutions in different sequences. Samples were examined by scanning electron microscopy. Representative images were scored based on the degree of smear layer remaining. Results were analysed with the SAS system, using the GENMOD procedure. Complete smear layer was found in samples treated with all solutions except EDTAC used alone. There were no significant differences between the sequences, EDTAC/NaOCl/EDTAC and NaOCl/EDTAC/NaOCl. There were no significant differences between groups with and without bicarbonate soda. In conclusion, the model was effective for testing chemical effects on solutions on smear layer. Bicarbonate soda did not remove smear layer and provided no additional cleaning effects after EDTAC and NaOCl.

  9. The interaction of quinones, herbicides and bicarbonate with their binding environment and the acceptor side of photosystem II in photosynthesis

    NARCIS (Netherlands)

    Vermaas, W.

    1984-01-01

    In this thesis experiments are described which are directed towards a further characterization of the interaction of the native bound plastoquinone Q B , artificial quinones, herbicides and bicarbonate with their binding environment at the acceptor side of Photosystem II in the thylakoid

  10. Analysis of ammonia-oxidizing bacteria dominating in lab-scale bioreactors with high ammonium bicarbonate loading

    NARCIS (Netherlands)

    Vejmelkova, D.; Sorokin, D.Y.; Abbas, B.; Kovaleva, O.L.; Kleerebezem, R.; Kampschreur, M.J.; Muyzer, G.; Van Loosdrecht, M.C.M.

    2011-01-01

    The ammonia-oxidizing bacterial community (AOB) was investigated in two types of laboratory-scale bioreactors performing partial oxidation of ammonia to nitrite or nitrate at high (80 mM) to extremely high (428 mM) concentrations of ammonium bicarbonate. At all conditions, the dominant AOB was affil

  11. Analysis of ammonia-oxidizing bacteria dominating in lab-scale bioreactors with high ammonium bicarbonate loading

    NARCIS (Netherlands)

    D. Vejmelkova; D.Y. Sorokin; B. Abbas; O.L. Kovaleva; R. Kleerebezem; M.J. Kampschreur; G. Muyzer; M.C.M. van Loosdrecht

    2012-01-01

    The ammonia-oxidizing bacterial community (AOB) was investigated in two types of laboratory-scale bioreactors performing partial oxidation of ammonia to nitrite or nitrate at high (80 mM) to extremely high (428 mM) concentrations of ammonium bicarbonate. At all conditions, the dominant AOB was affil

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

    Directory of Open Access Journals (Sweden)

    Jessica LaRusch

    2014-07-01

    Full Text Available 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

  13. Identification of wild soybean (Glycine soja) TIFY family genes and their expression profiling analysis under bicarbonate stress.

    Science.gov (United States)

    Zhu, Dan; Bai, Xi; Luo, Xiao; Chen, Qin; Cai, Hua; Ji, Wei; Zhu, Yanming

    2013-02-01

    Wild soybean (Glycine soja L. G07256) exhibits a greater adaptability to soil bicarbonate stress than cultivated soybean, and recent discoveries show that TIFY family genes are involved in the response to several abiotic stresses. A genomic and transcriptomic analysis of all TIFY genes in G. soja, compared with G. max, will provide insight into the function of this gene family in plant bicarbonate stress response. This article identified and characterized 34 TIFY genes in G. soja. Sequence analyses indicated that most GsTIFY proteins had two conserved domains: TIFY and Jas. Phylogenetic analyses suggested that these GsTIFY genes could be classified into two groups. A clustering analysis of all GsTIFY transcript expression profiles from bicarbonate stress treated G. soja showed that there were five different transcript patterns in leaves and six different transcript patterns in roots when the GsTIFY family responds to bicarbonate stress. Moreover, the expression level changes of all TIFY genes in cultivated soybean, treated with bicarbonate stress, were also verified. The expression comparison analysis of TIFYs between wild and cultivated soybeans confirmed that, different from the cultivated soybean, GsTIFY (10a, 10b, 10c, 10d, 10e, 10f, 11a, and 11b) were dramatically up-regulated at the early stage of stress, while GsTIFY 1c and 2b were significantly up-regulated at the later period of stress. The frequently stress responsive and diverse expression profiles of the GsTIFY gene family suggests that this family may play important roles in plant environmental stress responses and adaptation.

  14. Lack of the sodium-driven chloride bicarbonate exchanger NCBE impairs visual function in the mouse retina.

    Directory of Open Access Journals (Sweden)

    Gerrit Hilgen

    Full Text Available Regulation of ion and pH homeostasis is essential for normal neuronal function. The sodium-driven chloride bicarbonate exchanger NCBE (Slc4a10, a member of the SLC4 family of bicarbonate transporters, uses the transmembrane gradient of sodium to drive cellular net uptake of bicarbonate and to extrude chloride, thereby modulating both intracellular pH (pH(i and chloride concentration ([Cl(-](i in neurons. Here we show that NCBE is strongly expressed in the retina. As GABA(A receptors conduct both chloride and bicarbonate, we hypothesized that NCBE may be relevant for GABAergic transmission in the retina. Importantly, we found a differential expression of NCBE in bipolar cells: whereas NCBE was expressed on ON and OFF bipolar cell axon terminals, it only localized to dendrites of OFF bipolar cells. On these compartments, NCBE colocalized with the main neuronal chloride extruder KCC2, which renders GABA hyperpolarizing. NCBE was also expressed in starburst amacrine cells, but was absent from neurons known to depolarize in response to GABA, like horizontal cells. Mice lacking NCBE showed decreased visual acuity and contrast sensitivity in behavioral experiments and smaller b-wave amplitudes and longer latencies in electroretinograms. Ganglion cells from NCBE-deficient mice also showed altered temporal response properties. In summary, our data suggest that NCBE may serve to maintain intracellular chloride and bicarbonate concentration in retinal neurons. Consequently, lack of NCBE in the retina may result in changes in pH(i regulation and chloride-dependent inhibition, leading to altered signal transmission and impaired visual function.

  15. Enhanced U(VI) release from autunite mineral by aerobic Arthrobacter sp. in the presence of aqueous bicarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Katsenovich, Yelena; Carvajal, Denny A.; Wellman, Dawn M.; Lagos, Leonel

    2012-04-20

    The bacterial effect on U(VI) leaching from the autunite mineral (Ca[(UO{sub 2})(PO{sub 4})]{sub 2} {center_dot} 3H{sub 2}O) was investigated to provide a more comprehensive understanding into important microbiological processes affecting autunite stability within subsurface bicarbonate-bearing environments. Experiments were performed in a culture of G975 Arthrobacter oxydans strain, herein referred to as G975, a soil bacterium previously isolated from Hanford Site soil. 91 mg of autunite powder and 50 mL of phosphorus-limiting sterile media were amended with bicarbonate ranging between 1-10 mM in glass reactor bottles and inoculated with G975 strain after the dissolution of autunite was at steady state. SEM observations indicated G975 formed a biofilm on the autunite surface and penetrated the mineral cleavages. The mineral surface colonization by bacteria tended to increase concomitantly with bicarbonate concentrations. Additionally, a sterile cultureware with inserts was used in non-contact bioleaching experiments where autunite and bacteria cells were kept separately. The data suggest the G975 bacteria is able to enhance U(VI) leaching from autunite without the direct contact with the mineral. In the presence of bicarbonate, the damage to bacterial cells caused by U(VI) toxicity was reduced, yielding similar values for total organic carbon (TOC) degradation and cell density compared to U(VI)-free controls. The presence of active bacterial cells greatly enhanced the U(VI) bioleaching from autunite in bicarbonate-amended media.

  16. Enhanced U(VI) release from autunite mineral by aerobic Arthrobacter sp. in the presence of aqueous bicarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Katsenovich, Yelena P.; Carvajal, Denny A.; Wellman, Dawn M.; Lagos, Leonel E.

    2012-05-01

    The bacterial effect on U(VI) release from the autunite mineral (Ca[(UO2)(PO4)]2•3H2O) was investigated to provide a more comprehensive understanding of the important microbiological processes affecting autunite stability within subsurface bicarbonate-bearing environments. Experiments were performed in a culture of the Arthrobacter oxydans G975 strain, herein referred to as G975, a soil bacterium previously isolated from Hanford Site soil. 91 mg of autunite powder and 50 mL of phosphorous-limiting sterile media were amended with bicarbonate (ranging between 1 and 10 mM) in glass reactor bottles and inoculated with the G975 strain after the dissolution of autunite was at steady state. SEM observations indicated that G975 formed a biofilm on the autunite surface and penetrated the mineral cleavages. The mineral surface colonization by bacteria tended to increase concomitantly with bicarbonate concentrations. Additionally, a sterile culture-ware with inserts was used in non-contact dissolution experiments where autunite and bacteria cells were kept separately. The data suggest that G975 bacteria is able to enhance the release of U(VI) from autunite without direct contact with the mineral. In the presence of bicarbonate, the damage to bacterial cells caused by U(VI) toxicity was reduced, yielding similar values for total organic carbon (TOC) degradation and cell density compared to U(VI)-free controls. The presence of active bacterial cells greatly enhanced the release of U(VI) from autunite in bicarbonate-amended media.

  17. In Vivo Predictive Dissolution: Comparing the Effect of Bicarbonate and Phosphate Buffer on the Dissolution of Weak Acids and Weak Bases.

    Science.gov (United States)

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

    2015-09-01

    Bicarbonate is the main buffer in the small intestine and it is well known that buffer properties such as pKa can affect the dissolution rate of ionizable drugs. However, bicarbonate buffer is complicated to work with experimentally. Finding a suitable substitute for bicarbonate buffer may provide a way to perform more physiologically relevant dissolution tests. The dissolution of weak acid and weak base drugs was conducted in bicarbonate and phosphate buffer using rotating disk dissolution methodology. Experimental results were compared with the predicted results using the film model approach of (Mooney K, Mintun M, Himmelstein K, Stella V. 1981. J Pharm Sci 70(1):22-32) based on equilibrium assumptions as well as a model accounting for the slow hydration reaction, CO2 + H2 O → H2 CO3 . Assuming carbonic acid is irreversible in the dehydration direction: CO2 + H2 O ← H2 CO3 , the transport analysis can accurately predict rotating disk dissolution of weak acid and weak base drugs in bicarbonate buffer. The predictions show that matching the dissolution of weak acid and weak base drugs in phosphate and bicarbonate buffer is possible. The phosphate buffer concentration necessary to match physiologically relevant bicarbonate buffer [e.g., 10.5 mM (HCO3 (-) ), pH = 6.5] is typically in the range of 1-25 mM and is very dependent upon drug solubility and pKa .

  18. Role of CCK-A receptor in the regulation of pancreatic bicarbonate secretion in conscious rats: a study in naturally occurring CCK-A receptor gene knockout rats.

    Science.gov (United States)

    Miyasaka, K; Suzuki, S; Kanai, S; Masuda, M; Funakoshi, A

    1999-10-01

    Whether cholecystokinin (CCK) has a direct action on duct cells and the role of CCK-A receptor in bicarbonate secretion were examined by comparing the results obtained from OLETF (CCK-A receptor-deficient rats) and control (LETO) rats. Rats were prepared with cannulae for draining bile and pancreatic juice separately, with two duodenal cannulae and an external jugular vein cannula. The experiments were conducted without anesthesia. The responses of bicarbonate secretion to intravenous infusion of CCK, acetyl-beta-methylcholine (Ach), and 2-deoxy-D-glucose (2DG), and to intraduodenal infusion of HCl and a liquid meal were examined. To examine the synergistic effect between CCK and secretin, the effect of CCK during a background secretin infusion was examined in LETO rats. CCK did not stimulate bicarbonate secretion in either strain, nor in LETO rats with secretin infusion. When gastric acid secretion was prevented by administration of omeprazole, Ach did not increase bicarbonate secretion, but 2DG did in both strains. Intraduodenal infusion of HCI and a liquid meal significantly increased bicarbonate secretion in both strains; however, the responses were much less in OLETF than LETO rats. In conclusion, intravenous injection of CCK did not stimulate bicarbonate secretion, and the lack of CCK-A receptor decreased bicarbonate secretion in response to luminal stimulants.

  19. Beneficial effect of sulphate-bicarbonate-calcium water on gallstone risk and weight control

    Science.gov (United States)

    Corradini, Stefano Ginanni; Ferri, Flaminia; Mordenti, Michela; Iuliano, Luigi; Siciliano, Maria; Burza, Maria Antonella; Sordi, Bruno; Caciotti, Barbara; Pacini, Maria; Poli, Edoardo; Santis, Adriano De; Roda, Aldo; Colliva, Carolina; Simoni, Patrizia; Attili, Adolfo Francesco

    2012-01-01

    AIM: To investigate the effect of drinking sulphate-bicarbonate-calcium thermal water (TW) on risk factors for atherosclerosis and cholesterol gallstone disease. METHODS: Postmenopausal women with functional dyspepsia and/or constipation underwent a 12 d cycle of thermal (n = 20) or tap (n = 20) water controlled drinking. Gallbladder fasting volume at ultrasound, blood vitamin E, oxysterols (7-β-hydroxycholesterol and 7-ketocholesterol), bile acid (BA), triglycerides, total/low density lipoprotein and high density lipoprotein cholesterol were measured at baseline and at the end of the study. Food consumption, stool frequency and body weight were recorded daily. RESULTS: Blood lipids, oxysterols and vitamin E were not affected by either thermal or tap water consumption. Fasting gallbladder volume was significantly (P < 0.005) smaller at the end of the study than at baseline in the TW (15.7 ± 1.1 mL vs 20.1 ± 1.7 mL) but not in the tap water group (19.0 ± 1.4 mL vs 19.4 ± 1.5 mL). Total serum BA concentration was significantly (P < 0.05) higher at the end of the study than at baseline in the TW (5.83 ± 1.24 μmol vs 4.25 ± 1.00 μmol) but not in the tap water group (3.41 ± 0.46 μmol vs 2.91 ± 0.56 μmol). The increased BA concentration after TW consumption was mainly accounted for by glycochenodeoxycholic acid. The number of pasta (P < 0.001), meat (P < 0.001) and vegetable (P < 0.005) portions consumed during the study and of bowel movements per day (P < 0.05) were significantly higher in the TW than in the tap water group. Body weight did not change at the end of the study as compared to baseline in both groups. CONCLUSION: Sulphate-bicarbonate-calcium water consumption has a positive effect on lithogenic risk and intestinal transit and allows maintenance of a stable body weight despite a high food intake. PMID:22408352

  20. Beneficial effect of sulphate-bicarbonate-calcium water on gallstone risk and weight control

    Institute of Scientific and Technical Information of China (English)

    Stefano Ginanni Corradini; Edoardo Poli; Adriano De Santis; Aldo Roda; Carolina Colliva; Patrizia Simoni; Adolfo Francesco Attili; Flaminia Ferri; Michela Mordenti; Luigi Iuliano; Maria Siciliano; Maria Antonella Burza; Bruno Sordi; Barbara Caciotti; Maria Pacini

    2012-01-01

    AIM:To investigate the effect of drinking sulphate-bicarbonate-calcium thermal water (TW) on risk factors for atherosclerosis and cholesterol gallstone disease.METHODS:Postmenopausal women with functional dyspepsia and/or constipation underwent a 12 d cycle of thermal (n =20) or tap (n =20) water controlled drinking.Gallbladder fasting volume at ultrasound,blood vitamin E,oxysterols (7-β-hydroxycholesterol.and 7-ketocholesterol),bile acid (BA),triglycerides,total/low density lipoprotein and high density lipoprotein cholesterol were measured at baseline and at the end of the study.Food consumption,stool frequency and body weight were recorded daily.RESULTS:Blood lipids,oxysterols and vitamin E were not affected by either thermal or tap water consumption.Fasting gallbladder volume was significantly (P <0.005) smaller at the end of the study than at baseline in the TW (15.7 ± 1.1 mL vs 20.1 ± 1.7 mL) but not in the tap water group (19.0 ± 1.4 mL vs 19.4 ± 1.5 mL).Total serum BA concentration was significantly (P <0.05) higher at the end of the study than at baseline in the TW (5.83-1.24 μmol vs 4.25 ± 1.00 μmol) but not in the tap water group (3.41 ± 0.46 μmol vs 2.91 ± 0.56 μmol).The increased BA concentration after TW consumption was mainly accounted for by glycochenodeoxycholic acid.The number of pasta (P < 0.001),meat (P < 0.001) and vegetable (P < 0.005) portions consumed during the study and of bowel movements per day (P < 0.05) were significantly higher in the TW than in the tap water group.Body weight did not change at the end of the study as compared to baseline in both groups.CONCLUSION:Sulphate-bicarbonate-calcium water consumption has a positive effect on lithogenic risk and intestinal transit and allows maintenance of a stable body weight despite a high food intake.

  1. Variability of Acid-Base Status in Acetate-Free Biofiltration 84% versus Bicarbonate Dialysis

    Directory of Open Access Journals (Sweden)

    Harzallah Kais

    2008-01-01

    Full Text Available The ultimate goal of hemodialysis (HD treatment is to achieve the highest level of efficacy in the presence of maximal clinical tolerance. With an aim to offer good hemodynamic stability, as observed during the acetate-free biofiltration 14% (AFB 14% to patients who are intolerant to bicarbonate dialysis (BD and with less cost, we have developed since June 1994, a new HD technique, namely AFB 84%. This study was carried out to analyze acid-base variations during the AFB 84% in comparison to BD in hemodynamically stable patients on regular HD. This was a prospective randomized crossover study carried out on 12 patients (6 males and 6 females for a total of 144 HD sessions (72 BD and 72 AFB 84%. Patients with decompensated cardiomyopathy, respiratory diseases or uncontrolled hypertension were not included in the trial. All the patients were treated with BD or AFB 84%; the latter is characterized by the absence of acetate in the dialysate and a complete correction of buffer balance by post-dilutional infusion of bicarbonate-based replacement solution. The comparison of pre-dialysis arterial acid-base and blood-gas parameters revealed no significant differences of pH, HCO 3 - and paCO 2 levels between the two techniques. Analysis of post-dialysis parameters showed that, among patients dialyzed with BD, there was over correction of metabolic acidosis with a tendency towards metabolic alkalosis. In contrast, in patients dialyzed with AFB 84%, we observed a significant improvement in pH and HCO 3 - levels but the increase in paCO2 level was not significant. A comparison of these parameters between the two techniques showed statistically significant difference in pH, HCO3 - and paCO2 levels, but not for paO2 level. AFB 84% can offer some important advantages with the complete absence of acetate from the substitution fluids, and permits a better correction of metabolic acidosis than BD, without causing alkalosis.

  2. Evolution of a physiological pH 6.8 bicarbonate buffer system: application to the dissolution testing of enteric coated products.

    OpenAIRE

    Liu, Fang; Merchant, Hamid A.; Kulkarni, Rucha P.; Alkademi, Maram; Basit, Abdul W

    2011-01-01

    The use of compendial pH 6.8 phosphate buffer to assess dissolution of enteric coated products gives rise to poor in vitro-in vivo correlations because of the inadequacy of the buffer to resemble small intestinal fluids. A more representative and physiological medium, pH 6.8 bicarbonate buffer, was developed to evaluate the dissolution behaviour of enteric coatings. The bicarbonate system was evolved from pH7.4 Hanks balanced salt solution to produce a pH 6.8 bicarbonate buffer (modified Hank...

  3. Inhibition of cobalt active dissolution by benzotriazole in slightly alkaline bicarbonate aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Gallant, Danick [Departement de Chimie, Universite Laval, Quebec (Canada); Departement de Biologie, Chimie et Geographie, Universite du Quebec a Rimouski, 300, Allee des Ursulines, Rimouski, Quebec (Canada); E-mail: danick.gallant.1@ulaval.ca; Pezolet, Michel [Departement de Chimie, Universite Laval, Quebec (Canada)]. E-mail: michel.pezolet@chm.ulaval.ca; Simard, Stephan [Departement de Chimie, Universite Laval, Quebec (Canada); Departement de Biologie, Chimie et Geographie, Universite du Quebec a Rimouski, 300, Allee des Ursulines, Rimouski, Quebec (Canada); E-mail: stephan_simard@uqar.qc.ca

    2007-04-20

    The efficiency of benzotriazole as inhibiting agent for the corrosion of cobalt was probed at pH ranging from 8.3 to 10.2 in a sodium bicarbonate solution, chosen to simulate mild natural environments. From electrochemical, Raman spectroscopy, atomic force microscopy and ellipsometry experiments, we have demonstrated that benzotriazole markedly affects the electrodissolution reactions, which become modeled by the formation of a [Co(II)(BTA){sub 2}.H{sub 2}O] {sub n} film according to two different mechanisms. Surface-enhanced Raman spectroscopy has shown that the polarization of a cobalt electrode at cathodic potentials with respect to its potential of zero charge allows a mechanism of specific adsorption of the neutral form of benzotriazole to take place through a suspected metal-to-molecule electron transfer and which follows Frumkin's adsorption isotherms. At the onset of the anodic dissolution, some experimental evidence suggests that these adsorbed neutral benzotriazole molecules deprotonate to yield a very thin [Co(II)(BTA){sub 2}.H{sub 2}O] {sub n} polymer-like and water-insoluble protective film, responsible for the inhibition of active dissolution processes occurring at slightly more anodic potentials. In the anodic dissolution region, deprotonated benzotriazole species present in the bulk solution favors the formation of a multilayered [Co(II)(BTA){sub 2}.H{sub 2}O] {sub n} film, which also contributes to the inhibition of any further cobalt dissolution usually observed at higher electrode potentials.

  4. Alleviating versus stimulating effects of bicarbonate on the growth of Vallisneria natans under ammonia stress.

    Science.gov (United States)

    Dou, Yanyan; Wang, Baozhong; Chen, Liangyan; Yin, Daqiang

    2013-08-01

    Bicarbonate plays a crucial role in limiting the growth of submersed aquatic macrophytes in eutrophic lakes, and high ammonia is often toxic to macrophytes. In order to evaluate the combined effect of HCO3 (-) and total ammonia (i.e., the total of NH3 and NH4 (+)) on submersed macrophytes Vallisneria natans, the growth and physiological response of V. natans in the presence of HCO3 (-) and ammonia were studied. The results showed that with the increase of ammonia, morphological parameters of V. natans declined. In contrast, increased HCO3 (-) concentration stimulated the growth of V. natans, especially when the NH4 (+)-N/NO3 (-)-N ratio was 1:7. High ammonia concentration induced excess free amino acids (FAA) accumulation and soluble carbohydrates (SC) depletion in plant tissues. However, the elevated HCO3 (-) promoted the synthesis of SC and rendered the decrease of FAA/SC ratio. The results also suggested that HCO3 (-) could partially alleviate the stress of ammonia, as evidenced by the decrease of FAA/SC ratio and the growth enhancement of V. natans when the ammonia concentration was 0.58 mg L(-1). Given the fact that HCO3 (-) is probably the dominant available carbon source in most eutrophic lakes, the ability of V. natans to use HCO3 (-) for SC synthesis may explain the alleviating effect of HCO3 (-) on V. natans under ammonia stress.

  5. Preventive and therapeutic effects of sodium bicarbonate on melamine-induced bladder stones in mice.

    Science.gov (United States)

    Ren, Shu-Ting; Du, Yun-Xia; Xu, Chang-Fu; Zhang, Jiao-Jiao; Mo, Li-Ping; Sun, Ying; Gao, Xiao-Li

    2014-10-01

    The actual preventive and therapeutic effects of alkalinizing urine on melamine-induced bladder stones (cystolith) are not completely known. Using an ideal model, two experiments were conducted in Balb/c mice. The mice were fed a normal diet in controls and a melamine diet in the other groups. The first day was set as experiment-day 1. In "Experiment 1", either low-/mid-/high-dose sodium bicarbonate (SB) or sterile water was administered by intragastric perfusion (once daily) to the mice for 14 days. Relative to the model group, the mean pH of the urine in the SB groups was significantly elevated at 3 h after SB administration, with a significant decrease in cystolith incidence on experiment-day 14. In "Experiment 2", on experiment-day 12, the melamine diet was replaced by a normal diet in 4 groups with melamine withdrawal (MW). Meanwhile, either mid-/high-dose SB or sterile water was administered by intragastric perfusion (once) to the mice in the corresponding groups. On experiment-day 12, after an additional 8 h, the cystolith incidence was significantly reduced in the high-SB, MW + mid-SB and MW + high-SB groups than in the model group. In conclusion, low urinary pH is one of the main determinants of the formation of melamine-associated stones, urinary alkalinization can be achieved by a proper dose of oral SB, and SB acts to prevent and treat melamine-induced cystoliths in mice.

  6. Does bicarbonated mineral water rich in sodium change insulin sensitivity of postmenopausal women?

    Directory of Open Access Journals (Sweden)

    S. Schoppen

    Full Text Available Aim: To study the effects of drinking 0.5 L of two sodium-rich bicarbonated mineral waters (BMW-1 and 2, with a standard meal, on postprandial insulin and glucose changes. And to determine, if the effects vary depending on insulin resistance, measured by homeostasis model assessment (HOMA. Methods: In a 3-way randomized crossover study, 18 healthy postmenopausal women consumed two sodiumrich BMWs and a low-mineral water (LMW with a standard fat-rich meal. Fasting and postprandial blood samples were taken at 30, 60 and 120 min. Serum glucose, insulin, cholesterol and triacylglycerols were determined. Insulin resistance was estimated by HOMA and insulin sensitivity was calculated by quantitative insulin sensitivity check index (QUICKY. Results: Glucose levels did not change. HOMA and QUICKY values were highly inversely correlated (r = -1,000; p < 0.0001. Insulin concentrations showed a significant time effect (p < 0.0001 and a significant water x time interaction (p < 0.021. At 120 min insulin levels with BMW-1 were significantly lower than with LMW (p = 0.022. Postprandial insulin concentrations showed significantly different patterns of mineral water intake depending on HOMA n-tiles (p = 0.016. Conclusion: Results suggests an increase in insulin sensitivity after BMWs consumption. This effect is more marked in the women, who have higher HOMA values. These waters should be considered part of a healthy diet in order to prevent insulin resistance and cardiovascular disease.

  7. The Consumption of Bicarbonate-Rich Mineral Water Improves Glycemic Control

    Directory of Open Access Journals (Sweden)

    Shinnosuke Murakami

    2015-01-01

    Full Text Available Hot spring water and natural mineral water have been therapeutically used to prevent or improve various diseases. Specifically, consumption of bicarbonate-rich mineral water (BMW has been reported to prevent or improve type 2 diabetes (T2D in humans. However, the molecular mechanisms of the beneficial effects behind mineral water consumption remain unclear. To elucidate the molecular level effects of BMW consumption on glycemic control, blood metabolome analysis and fecal microbiome analysis were applied to the BMW consumption test. During the study, 19 healthy volunteers drank 500 mL of commercially available tap water (TW or BMW daily. TW consumption periods and BMW consumption periods lasted for a week each and this cycle was repeated twice. Biochemical tests indicated that serum glycoalbumin levels, one of the indexes of glycemic controls, decreased significantly after BMW consumption. Metabolome analysis of blood samples revealed that 19 metabolites including glycolysis-related metabolites and 3 amino acids were significantly different between TW and BMW consumption periods. Additionally, microbiome analysis demonstrated that composition of lean-inducible bacteria was increased after BMW consumption. Our results suggested that consumption of BMW has the possible potential to prevent and/or improve T2D through the alterations of host metabolism and gut microbiota composition.

  8. Geochemistry of fly ash from desulphurisation process performed by sodium bicarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Raclavska, Helena; Matysek, Dalibor; Raclavsky, Konstantin; Juchelkova, Dagmar [VSB - Technical University Ostrava, 17. listopadu 15, 708 33 Ostrava, Poruba (Czech Republic)

    2010-02-15

    The application of NEUTREC {sup registered} technology - desulphurisation by means of sodium bicarbonate - has been tested at the Trebovice coal-fired power plant (Ostrava, Czech Republic). This technology significantly influences the chemical composition of fly ash and the leachability of total dissolved substances (TDS), e.g., sulphates, fluorides and oxyanions (Se, Sb, Cr, As), which are monitored according to the Council of the European Union Decision 2003/33/EC. An increase of TDS in the water leachate from the fly ash obtained at 60% desulphurisation was influenced by sodium content, which is present in the form of Na{sup +} ions (85-90%). The percentages of sodium sulphate and sodium carbonate were between 5 and 10% of the total sodium content. In order to decrease the leachability of TDS, sodium, sulphates and oxyanion mixtures were prepared containing a sorbent (60% bentonite) and mixed with desulphurised and non-desulphurised fly ash in various ratios. The addition of CaO resulted in the formation of a new mineral phase, burkeite. None of the applied technologies tested for the processed fly ash resulted in the preparation of a water leachate which complied in all monitored parameters to the requirements of Council Decision 2003/33 EC for nonhazardous wastes. (author)

  9. Metabolic communication between astrocytes and neurons via bicarbonate-responsive soluble adenylyl cyclase.

    Science.gov (United States)

    Choi, Hyun B; Gordon, Grant R J; Zhou, Ning; Tai, Chao; Rungta, Ravi L; Martinez, Jennifer; Milner, Teresa A; Ryu, Jae K; McLarnon, James G; Tresguerres, Martin; Levin, Lonny R; Buck, Jochen; MacVicar, Brian A

    2012-09-20

    Astrocytes are proposed to participate in brain energy metabolism by supplying substrates to neurons from their glycogen stores and from glycolysis. However, the molecules involved in metabolic sensing and the molecular pathways responsible for metabolic coupling between different cell types in the brain are not fully understood. Here we show that a recently cloned bicarbonate (HCO₃⁻) sensor, soluble adenylyl cyclase (sAC), is highly expressed in astrocytes and becomes activated in response to HCO₃⁻ entry via the electrogenic NaHCO₃ cotransporter (NBC). Activated sAC increases intracellular cAMP levels, causing glycogen breakdown, enhanced glycolysis, and the release of lactate into the extracellular space, which is subsequently taken up by neurons for use as an energy substrate. This process is recruited over a broad physiological range of [K⁺](ext) and also during aglycemic episodes, helping to maintain synaptic function. These data reveal a molecular pathway in astrocytes that is responsible for brain metabolic coupling to neurons.

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

    Science.gov (United States)

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

    2010-01-05

    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 (HCO(3)(-)). We cloned the sAC ortholog from the dogfish, a shark that regulates blood A/B by absorbing and secreting protons (H(+)) and HCO(3)(-) at its gills. Similar to mammalian sAC, dogfish soluble adenylyl cyclase (dfsAC) is activated by HCO(3)(-) 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 HCO(3)(-) 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.

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

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.; Skaar, Don

    2014-01-01

    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 NaHCO3 rise to more than 1500 mg/L (also expressed as >1245 mg HCO3 (-) /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.

  12. Biohydrogen Fermentation from Sucrose and Piggery Waste with High Levels of Bicarbonate Alkalinity

    Directory of Open Access Journals (Sweden)

    Jeongdong Choi

    2015-03-01

    Full Text Available This study examined the influence of biohydrogen fermentation under the high bicarbonate alkalinity (BA and pH to optimize these critical parameters. When sucrose was used as a substrate, hydrogen was produced over a wide range of pH values (5–9 under no BA supplementation; however, BA affected hydrogen yield significantly under different initial pHs (5–10. The actual effect of high BA using raw piggery waste (pH 8.7 and BA 8.9 g CaCO3/L showed no biogas production or propionate/acetate accumulation. The maximum hydrogen production rate (0.32 L H2/g volatile suspended solids (VSS-d was observed at pH 8.95 and 3.18 g CaCO3/L. BA greater than 4 g CaCO3/L also triggered lactate-type fermentation, leading to propionate accumulation, butyrate reduction and homoacetogenesis, potentially halting the hydrogen production rate. These results highlight that the substrate with high BA need to amend adequately to maximize hydrogen production.

  13. Degradation of Organophosphorus Pesticides in Water during UV/H2O2 Treatment: Role of Sulphate and Bicarbonate Ions

    Directory of Open Access Journals (Sweden)

    Am Fadaei

    2012-01-01

    Full Text Available The photodegradation of two organophosphorus pesticides, malathian and diazinon, by sulfate radicals and bicarbonate radicals in aqueous solution were studied. The effect of the operational parameters such as pH, salt concentration, water type, H2O2 concentration and initial concentration of pesticides was studied. Gas chromatography mass spectroscopy (GC–MS was used for analyses of pesticides. When salt effect was studied, it was found that sodium bicarbonate was the most powerful inhibitor used, while sodium sulfate was the weakest one. The highest degradation in UV/H2O2 process for malathion was found in alkaline condition and for diazinon in acidic condition. The photodegradation in all waters used in this work exhibited first order kinetics. Photodegradation rate in distilled water was higher than real water. The degradation of pesticides increased with increasing of H2O2 concentration.

  14. The Effect of Bicarbonate on the Microbial Dissolution of Autunite Mineral in the Presence of Gram-Positive Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Sepulveda-Medina, Paola; Katsenovich, Yelena; Wellman, Dawn M.; Lagos, Leonel

    2015-06-01

    Bacteria are key players in the processes that govern fate and transport of contaminants. The uranium release from Na and Ca-autunite by Arthrobacter oxydans strain G968 was evaluated in the presence of bicarbonate ions. This bacterium was previously isolated from Hanford Site soil and in earlier prescreening tests demonstrated low tolerance to U(VI) toxicity compared to other A.oxydans isolates. Experiments were conducted using glass serum bottles as mixed bioreactors and sterile 6-well cell culture plates with inserts separating bacteria cells from mineral solids. Reactors containing phosphorus-limiting media were amended with bicarbonate ranging between 0-10 mM and metaautunite solids to provide a U(VI) concentration of 4.4 mmol/L. Results showed that in the presence of bicarbonate, A.oxydans G968 was able to enhance the release of U(VI) from Na and Ca autunite at the same capacity as other A.oxydans isolates with relatively high tolerance to U(VI). The effect of bacterial strains on autunite dissolution decreases as the concentration of bicarbonate increases. The results illustrate that direct interaction between the bacteria and the mineral is not necessary to result in U (VI) biorelease from autunite. The formation of secondary calcium-phosphate mineral phases on the surface of the mineral during the dissolution can ultimately reduce the natural autunite mineral contact area, which bacterial cells can access. This thereby reduces the concentration of uranium released into the solution. This study provides a better understanding of the interactions between meta-autunite and microbes in conditions mimicking arid and semiarid subsurface environments of western U.S.

  15. Sodium bicarbonate for the prevention of contrast induced nephropathy: A meta-analysis of published clinical trials

    Energy Technology Data Exchange (ETDEWEB)

    Kunadian, Vijayalakshmi, E-mail: kunadianvijay@aol.com [Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne Hospitals, NHS Foundation Trust/Newcastle University, Newcastle upon Tyne (United Kingdom); Zaman, Azfar, E-mail: Azfar.Zaman@nuth.nhs.uk [Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne Hospitals, NHS Foundation Trust/Newcastle University, Newcastle upon Tyne (United Kingdom); Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne (United Kingdom); Spyridopoulos, Ioakim [Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne Hospitals, NHS Foundation Trust/Newcastle University, Newcastle upon Tyne (United Kingdom); Institute of Human Genetics, Newcastle University, Newcastle upon Tyne (United Kingdom); Qiu, Weiliang [Channing Laboratory, Department of Medicine, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA, United States of America (United States)

    2011-07-15

    Background: Contrast induced nephropathy (CIN) is a serious but rare complication following contrast based procedures. Sodium bicarbonate (NaHCO{sub 3}) has been postulated to prevent CIN by various mechanisms. However, the outcomes following sodium bicarbonate administration to prevent CIN have been inconsistent. Methods: A meta-analysis of published randomized clinical trials to determine if the administration of sodium bicarbonate is superior to sodium chloride among patients with chronic renal failure undergoing catheterization and interventional procedures in preventing CIN was performed. Results: Data were combined across seven published clinical trials consisting of 1734 patients. There were no significant differences in the baseline characteristics between the NaHCO{sub 3} and NaCl groups except patients in the bicarbonate group were heavier (P = 0.04). The odds ratio (OR) for the development of contrast nephropathy for NaHCO{sub 3} versus NaCl was 0.33 (95% confidence interval [CI] 0.16-0.69; P = 0.003). Heterogeneity and publication bias were detectable with P-values 0.01 and 0.0005 respectively. There was no difference between the NaHCO{sub 3} group and the NaCl group in the occurrence of death [OR 0.6; 95% CI (0.26-1.41); P = 0.24], congestive heart failure [OR 0.85; 95% CI (0.32-2.24); P = 0.74] and the requirement for renal replacement therapy [OR 0.56; 95% CI (0.22-1.41); P = 0.22]. Conclusion: This meta-analysis demonstrates that based on currently available randomized trials, the administration of NaHCO{sub 3} is superior to the administration of NaCl alone in the prevention of CIN among patients with moderate to severe chronic kidney disease. However, further controlled clinical trials are needed due to significant study heterogeneity and publication bias.

  16. The Renal Sodium Bicarbonate Cotransporter NBCe2: Is It a Major Contributor to Sodium and pH Homeostasis?

    Science.gov (United States)

    Felder, Robin A; Jose, Pedro A; Xu, Peng; Gildea, John J

    2016-09-01

    The sodium bicarbonate cotransporter (NBCe2, aka NBC4) was originally isolated from the human testis and heart (Pushkin et al. IUBMB Life 50:13-19, 2000). Subsequently, NBCe2 was found in diverse locations where it plays a role in regulating sodium and bicarbonate transport, influencing intracellular, extracellular, interstitial, and ultimately plasma pH (Boron et al. J Exp Biol. 212:1697-1706, 2009; Parker and Boron, Physiol Rev. 93:803-959, 2013; Romero et al. Mol Asp Med. 34:159-182, 2013). NBCe2 is located in human and rodent renal-collecting duct and proximal tubule. While much is known about the two electrogenic sodium bicarbonate cotransporters, NBCe1 and NBCe2, in the regulation of sodium homeostasis and pH balance in the rodent kidney, little is known about their roles in human renal physiology. NBCe2 is located in the proximal tubule Golgi apparatus under basal conditions and then disperses throughout the cell, but particularly into the apical membrane microvilli, during various maneuvers that increase intracellular sodium. This review will summarize our current understanding of the distribution and function of NBCe2 in the human kidney and how genetic variants of its gene, SLC4A5, contribute to salt sensitivity of blood pressure.

  17. Bicarbonate Plays a Critical Role in the Generation of Cytotoxicity during SIN-1 Decomposition in Culture Medium

    Directory of Open Access Journals (Sweden)

    Kyo Shirai

    2012-01-01

    Full Text Available 3-Morpholinosydnonimine (SIN-1 is used as a donor of peroxynitrite (ONOO− in various studies. We demonstrated, however, that, the cell-culture medium remains cytotoxic to PC12 cells even after almost complete SIN-1 decomposition, suggesting that reaction product(s in the medium, rather than ONOO−, exert cytotoxic effects. Here, we clarified that significant cytotoxicity persists after SIN-1 decomposes in bicarbonate, a component of the culture medium, but not in NaOH. Cytotoxic SIN-1-decomposed bicarbonate, which lacks both oxidizing and nitrosating activities, degrades to innocuous state over time. The extent of SIN-1 cytotoxicity, irrespective of its fresh or decomposed state, appears to depend on the total number of initial SIN-1 molecules per cell, rather than its concentration, and involves oxidative/nitrosative stress-related cell damage. These results suggest that, despite its low abundance, the bicarbonate-dependent cytotoxic substance that accumulates in the medium during SIN-1 breakdown is the cytotoxic entity of SIN-1.

  18. [Effect of mild irritants on gastric outputs of bicarbonates and pepsinogen depends on the rate of acid secretion].

    Science.gov (United States)

    Zolotarev, V A; Andreeva, Iu V; Khropycheva, R P

    2012-06-01

    The aggressive luminal content in the stomach activates gastroprotective processes affecting exocrine and endocrine secretion of gastric glands and permeability of the pre-epithelial mucus layer. The aim of the study was to investigate effects of chemical irritants similar to physiological characteristics of digestion (pH 2.0 and/or 500 mM NaCl) on outputs of bicarbonates and pepsinogen as well as assess the role of endogenous acid production in control ofnon-parietal secretion during irritation of the gastric mucosa. In experiments on conscious rats with chronic gastric fistula as well as on anesthetized animals it was demonstrated that luminal infusion of acidic hyperosmotic solution of NaCl enhances basal secretions of bicarbonates and pepsinogen that was fully blocked by indomethacin. Suppression of gastric acid secretion by omeprazole potentiates the stimulative effect of mild irritants likely due to the reduction of pH gradient on the surface of gastric mucosa which causes the growth of sensitivity of the epithelium to chemical stimuli and the increase of synthesis ofprostaglandins. Additionally, mild irritation enhances secretion of HCO3(-) and pepsinogen induced by stimulation of the vagus nerve; and this response does not depend on the action ofprostaglandins. The enhancing effect of irritation on the vagally induced bicarbonate output was eliminated after the treatment with omeprazole.

  19. Role of the bicarbonate-responsive soluble adenylyl cyclase in pH sensing and metabolic regulation

    Directory of Open Access Journals (Sweden)

    Jung-Chin eChang

    2014-02-01

    Full Text Available The evolutionarily conserved soluble adenylyl cyclase (sAC, adcy10 was recently identified as a unique source of cAMP in the cytoplasm and the nucleus. Its activity is regulated by bicarbonate and fine-tuned by calcium. As such, and in conjunction with carbonic anhydrase (CA, sAC constitutes an HCO3-/CO¬2/pH sensor. In both alpha-intercalated cells of the collecting duct and the clear cells of the epididymis, sAC is expressed at significant level and involved in pH homeostasis via apical recruitment of vacuolar H+-ATPase (VHA in a PKA-dependent manner. In addition to maintenance of pH homeostasis, sAC is also involved in metabolic regulation such as coupling of Krebs cycle to oxidative phosphorylation via bicarbonate/CO2 sensing. Additionally, sAC also regulates CFTR channel and plays an important role in regulation of barrier function and apoptosis. These observations suggest that sAC, via bicarbonate-sensing, plays an important role in maintaining homeostatic status of cells against fluctuations in their microenvironment.

  20. Current Status of Sodium Bicarbonate in Coronary Angiography: An Updated Comprehensive Meta-Analysis and Systematic Review

    Directory of Open Access Journals (Sweden)

    Sadegh Ali-Hassan-Sayegh

    2015-01-01

    Full Text Available This systematic review with meta-analysis sought to determine comparison of efficacy and safety of hydration with sodium bicarbonate versus sodium chloride on contrast induced nephropathy and clinical outcomes. We searched major electronic databases for studies in randomized controlled trials. A value of P50% indicated significant heterogeneity between the studies. Literature search of all databases retrieved 650 studies. 29 studies enrolled in meta-analysis. Pooled analysis indicated about the incidence of CIN (OR of 0.718; 95% CI: 0.60 to 0.85; P=0.000, requirement of hemodialysis (OR of 1.00; 95% CI: 0.49 to 2.01; P=0.9, mean changes of serum creatinine (WMD of 2.321; 95% CI: 1.995 to 2.648; P=0.000, length of hospital stays (WMD of −0.774; 95% CI: −1.65 to 0.10; P=0.08, major adverse cardiovascular events (OR = 1.075, 95% CI: 0.59 to 1.95; P=0.8, and mortality (OR of 0.73; 95% CI: 0.42 to 1.26; P=0.2. Overall, hydration with sodium bicarbonate could significantly reduce CIN and the length of hospital stay compared to sodium chloride. In addition NAC added as a supplement to sodium bicarbonate could increase prophylactic effects against nephropathy.

  1. Effect of sodium bicarbonate air abrasive polishing on resistance to sliding during tooth alignment and leveling: An in vitro study

    Directory of Open Access Journals (Sweden)

    Jorge C. B. L. Filho

    2012-01-01

    Full Text Available Objective: The aim of this in vitro study was to evaluate the Resistance to Sliding (RS provided by metallic brackets and 3 types of orthodontic wires (TMA, SS and NiTi, before and after the use of sodium bicarbonate airborne particle abrasion, in an experimental model with 3 non leveled brackets. Materials and Methods: The bicarbonate airborne abrasion was applied perpendicularly to the bracket slots at a distance of 2 mm, for 5 seconds (T2 and 10 seconds (T3 on each bracket slot. In a universal testing machine, the wires were pulled through a set of 3 non leveled brackets at a cross head speed of 50 mm/min for a distance of 10 mm, and static and kinetic friction readings were registered at T1 (no airborne abrasion, T2 and T3. Results: For all tested wires, a significant RS increase between T1 and T3 (P<0.001 was seen. For SS and TMA wires, there was a statistically significant RS increase between T1 and T2 (P<0.001. Between T2 and T3, RS increase was significant for TMA (P<0.001 and NiTiwires (P<0.05. Conclusions: Sodium bicarbonate air abrasive polishing during orthodontic treatment is not recommended, once this procedure promoted a significant RS increase between the metallic brackets and all the three types of wires tested.

  2. Selection of microalgae and cyanobacteria strains for bicarbonate-based integrated carbon capture and algae production system.

    Science.gov (United States)

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

    2014-01-01

    Using microalgae to capture CO2 from flue gas is an ideal way to reduce CO2 emission, but this is challenged by the high cost of carbon capture and transportation. To address this problem, a bicarbonate-based integrated carbon capture and algae production system (BICCAPS) has been proposed, in which bicarbonate is used for algae culture, and the regenerated carbonate from this process can be used to capture more CO2. High-concentration bicarbonate is obligate for the BICCAPS. Thus, different strains of microalgae and cyanobacteria were tested in this study for their capability to grow in high-concentration NaHCO3. The highest NaHCO3 concentrations they are tolerant to were determined as 0.30 M for Synechocystis sp. PCC6803, 0.60 M for Cyanothece sp., 0.10 M for Chlorella sorokiniana, 0.60 M for Dunaliella salina, and 0.30 M for Dunaliella viridis and Dunaliella primolecta. In further study, biomass production from culture of D. primolecta in an Erlenmeyer flask with either 0.30 M NaHCO3 or 2 % CO2 bubbling was compared, and no significant difference was detected. This indicates BICCAPS can reach the same biomass productivity as regular CO2 bubbling culture, and it is promising for future application.

  3. Mechanisms involved in ketone body release by rat liver cells: influence of pH and bicarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Fafournoux, P.; Demigne, C.; Remesy, C.

    1987-02-01

    The aim of the present work is to study the intra- and extracellular concentration gradient of ketone bodies across the hepatic cell membrane, ketone bodies released by liver cells, and the effects of changes in acid-base status on these processes. Ketone bodies appeared to be released by liver cells against a concentration gradient both in vivo and in vitro. In vitro, a decrease in external pH and bicarbonate gradient measured with ( UC)- and (TH)-labelled compounds, and efflux rates. Analysis of the distribution ratio of ketone bodies as a function of pH across the cell membrane indicates that additional factors must be invoked to account for the observed distribution ratios. These data along with measurement of ketone body efflux are consistent with the existence of a system promoting the efflux of ketone bodies from liver cells, which is trans-stimulated by external bicarbonate. In vivo, ketogenesis was also inhibited by acidosis, and slightly enhanced by bicarbonate infusion, although this was not solely due to effects on transfer across the cell membrane. The study indicates that the hepatic release of ketone bodies might be auto-limited by ketoacidosis.

  4. Topology mapping to characterize cyanobacterial bicarbonate transporters: BicA (SulP/SLC26 family) and SbtA.

    Science.gov (United States)

    Price, G Dean; Howitt, Susan M

    2014-09-01

    This mini-review addresses advances in understanding the transmembrane topologies of two unrelated, single-subunit bicarbonate transporters from cyanobacteria, namely BicA and SbtA. BicA is a Na(+)-dependent bicarbonate transporter that belongs to the SulP/SLC26 family that is widespread in both eukaryotes and prokaryotes. Topology mapping of BicA via the phoA/lacZ fusion reporter method identified 12 transmembrane helices with an unresolved hydrophobic region just beyond helix 8. Re-interpreting this data in the light of a recent topology study on rat prestin leads to a consensus topology of 14 transmembrane domains with a 7+7 inverted repeat structure. SbtA is also a Na(+)-dependent bicarbonate transporter, but of considerably higher affinity (Km 2-5 μM versus >100 μM for BicA). Whilst SbtA is widespread in cyanobacteria and a few bacteria, it appears to be absent from eukaryotes. Topology mapping of SbtA via the phoA/lacZ fusion reporter method identified 10 transmembrane helices. The topology consists of a 5+5 inverted repeat, with the two repeats separated by a large intracellular loop. The unusual location of the N and C-termini outside the cell raises the possibility that SbtA forms a novel fold, not so far identified by structural and topological studies on transport proteins.

  5. Gastric bicarbonate secretion and release of prostaglandin E2 are increased in duodenal ulcer patients but not in Helicobacter pylori-positive healthy subjects

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Hillingsø, Jens; Frøkiaer, H;

    1996-01-01

    was present also in the stomach of DU patients. METHODS: Simultaneous determinations of gastric and duodenal bicarbonate secretion and luminal release of PGE2 were performed in 16 healthy volunteers (5 Helicobacter pylori-positive) and 8 inactive DU patients (all H. pylori-positive). RESULTS: In healthy...... volunteers the rates of gastroduodenal bicarbonate secretion and the release of PGE2 were not influenced by H. pylori status. In inactive DU patients the rates of basal (704 +/- 84 versus 356 +/- 40 mumol/h; mean +/- SEM) and vagally stimulated (modified sham feeding) (1724 +/- 376 versus 592 +/- 52 mumol...... for the abnormally high gastric secretion of bicarbonate in inactive DU patients. The defective duodenal secretion of bicarbonate observed in these patients may be a consequence of previous ulceration rather than the mere presence of H. pylori infection....

  6. Gastric bicarbonate secretion and release of prostaglandin E2 are increased in duodenal ulcer patients, but not in Helicobacter pylori positive healthy subjects

    DEFF Research Database (Denmark)

    A, Mertz-Nielsen; Hillingsø, Jens; Frøkiær, Hanne;

    1996-01-01

    was present also in the stomach of DU patients. Methods: Simultaneous determinations of gastric and duodenal bicarbonate secretion and luminal release of PGE(2) were performed in 16 healthy volunteers (5 Helicobacter pylori-positive) and 8 inactive DU patients (all H. pylori-positivr). Results: In healthy...... volunteers the rates of gastroduodenal bicarbonate secretion and the release of PGE(2), were not influenced by H. pylori status. In inactive DU patients the rates of basal (704 +/- 84 versus 356 +/- 40 mu mol/h: mean +/- SEM) and vagally stimulated (modified sham feeding) (1724 +/- 376 versus 592 +/- 52 mu...... be responsible for the abnormally high gastric secretion of bicarbonate in inactive DU patients. Th; defective duodenal secretion of bicarbonate observed in these patients may be a consequence of previous ulceration rather than the mere presence of H. pylori infection....

  7. Intercultural Mediation

    OpenAIRE

    Dragos Marian Radulescu; Denisa Mitrut

    2012-01-01

    The Intercultural Mediator facilitates exchanges between people of different socio-cultural backgrounds and acts as a bridge between immigrants and national and local associations, health organizations, services and offices in order to foster integration of every single individual. As the use mediation increases, mediators are more likely to be involved in cross-cultural mediation, but only the best mediators have the opportunity to mediate cross border business disputes or international poli...

  8. Effect of Chewing Bicarbonate-containing Sugar-free Gum on the Salivary pH: An in vivo Study.

    Science.gov (United States)

    Ballal, Raksha K; Bhat, Sham S; Ramdas, Shenoy Shailesh; Ballal, Shrinidhi

    2016-01-01

    The objective of the study was to evaluate the effect of chewing gum on the salivary pH and to compare the effect of chewing bicarbonate-containing sugar-free gum on salivary pH against that of standard sugar-free gum. The experiment was carried out on 30 volunteers aged 20-22 years (mean age = 21 years) who fulfilled the inclusion criteria. The test gum was sugar-free greenmint-flavored bicarbonate-containing gum and the standard control was sugar-free spearmint-flavored gum. The pH was measured immediately using pH strips. According to statistical analysis, the mean salivary pH of the bicarbonate gum at 0, 5, 10, 15 and 20 minutes is 6.9713, 6.5667, 6.4267, 6.3867 and 6.3233 respectively. There is decrease in pH from 0 to 20 minutes. According to Bonferroni, there was no significant difference in pH from 0 to 20 minutes, 10 to 20 minutes and 15 to 20 minutes, but there was a significant difference in salivary pH from 5 to 20 minutes (p = 0.014). The mean salivary pH of the standard gum at 0, 5, 10, 15 and 20 minutes is 6.8767, 6.6067, 6.4200, 6.4027 and 6.3000 respectively. There is decrease in pH from 0 to 20 minutes. According to Bonferroni, there was no significant difference in pH from 0 to 20 minutes, 5 to 20 minutes, 10 to 20 minutes and 15 to 20 minutes. Thus, the higher salivary pH achieved with chewing bicarbonate gum compared with a standard sugar-free gum may have important oral health implications. How to cite this article: Ballal RK, Bhat SS, Ramdas SS, Ballal S. Effect of Chewing Bicarbonate-containing Sugar-free Gum on the Salivary pH: An in vivo Study. Int J Clin Pediatr Dent 2016;9(1):35-38.

  9. Omeprazole/Antacid-powder suspension-Santarus: omeprazole/sodium bicarbonate powder-Santarus, SAN 05.

    Science.gov (United States)

    2004-01-01

    Santarus Inc. is developing an immediate-release formulation of omeprazole in combination with an antacid (sodium bicarbonate) as a powder for suspension, known as Acitreltrade mark [SAN 05] and also as Rapinex powder for oral suspension. This omeprazole powder suspension will be used to treat gastrointestinal haemorrhage, gastro-oesophageal reflux disease, heartburn and peptic ulcers. Acitreltrade mark is based on technology licensed from the University of Missouri. Santarus have also licensed technology from Tulane and North Carolina Universities relating to potential treatments for gastrointestinal (GI) diseases. Santarus has licensed exclusive, worldwide rights to patent applications covering specific combination formulations of proton pump inhibitors (PPIs) and antacids for treating various upper GI diseases and disorders. Santarus plans to license the development, distribution and marketing rights of omeprazole powder for oral suspension 20 mg outside the US, to one or more well established pharmaceutical companies. The US FDA has requested that Santarus pursue a name other than Rapinex for the product. Santarus is currently discussing potential alternative names for the product with the FDA. Santarus announced positive results in August 2003 from a phase III trial comparing oral Acitrel (Rapinex 40 mg) with intravenous cimetidine in preventing upper GI bleeding in 359 critically ill adult patients. Santarus has also completed an open-label clinical trial in 243 patients, including 97 patients with gastric ulcers, evaluating the safety of this omeprazole 40 mg powder suspension for an 8-week period. In connection with the NDA for omeprazole powder suspension 40 mg, Santarus provided notice to the NDA holder for Prilosec delayed-release capsules and related patent owners that omeprazole powder suspension 40 mg does not infringe currently listed patents for Prilosec or that those patents are invalid.

  10. Ion transport mechanisms linked to bicarbonate secretion in the esophageal submucosal glands.

    Science.gov (United States)

    Abdulnour-Nakhoul, Solange; Nakhoul, Hani N; Kalliny, Medhat I; Gyftopoulos, Alex; Rabon, Edd; Doetjes, Rienk; Brown, Karen; Nakhoul, Nazih L

    2011-07-01

    The esophageal submucosal glands (SMG) secrete HCO(3)(-) and mucus into the esophageal lumen, where they contribute to acid clearance and epithelial protection. This study characterized the ion transport mechanisms linked to HCO(3)(-) secretion in SMG. We localized ion transporters using immunofluorescence, and we examined their expression by RT-PCR and in situ hybridization. We measured HCO(3)(-) secretion by using pH stat and the isolated perfused esophagus. Using double labeling with Na(+)-K(+)-ATPase as a marker, we localized Na(+)-coupled bicarbonate transporter (NBCe1) and Cl(-)-HCO(3)(-) exchanger (SLC4A2/AE2) to the basolateral membrane of duct cells. Expression of cystic fibrosis transmembrane regulator channel (CFTR) was confirmed by immunofluorescence, RT-PCR, and in situ hybridization. We identified anion exchanger SLC26A6 at the ducts' luminal membrane and Na(+)-K(+)-2Cl(-) (NKCC1) at the basolateral membrane of mucous and duct cells. pH stat experiments showed that elevations in cAMP induced by forskolin or IBMX increased HCO(3)(-) secretion. Genistein, an activator of CFTR, which does not increase intracellular cAMP, also stimulated HCO(3)(-) secretion, whereas glibenclamide, a Cl(-) channel blocker, and bumetanide, a Na(+)-K(+)-2Cl(-) blocker, decreased it. CFTR(inh)-172, a specific CFTR channel blocker, inhibited basal HCO(3)(-) secretion as well as stimulation of HCO(3)(-) secretion by IBMX. This is the first report on the presence of CFTR channels in the esophagus. The role of CFTR in manifestations of esophageal disease in cystic fibrosis patients remains to be determined.

  11. Thermal Care of Functional Dyspepsia Based on Bicarbonate-Sulphate-Calcium Water: A Sequential Clinical Trial

    Directory of Open Access Journals (Sweden)

    Giuseppe Rocca

    2007-01-01

    Full Text Available Drug treatment of functional dyspepsia is often unsatisfactory. We assessed the efficacy of a bicarbonate-sulphate-calcium thermal water cycle of 12 days, in patients with functional dyspepsia. Patients with functional dyspepsia were sent by their general practitioners to 12 days of treatment with thermal water, 200–400 ml in the morning, at temperature of 33°C (91.4 F and were evaluated on a strict intention to treat basis. Four efficacy endpoints were analyzed as follows: (i reduction of the global symptoms score, (ii reduction of intensity to a level not interfering with everyday activities, (iii specific efficacy on ulcer-like or dysmotility-like dyspepsia and (iv esophageal or abdominal-associated symptoms. Statistical significance was reached for all three primary outcomes after the first 29 consecutive patients. Thermal water reduced the global symptom score, reduced intensity of symptoms to a level not interfering with everyday activity, but was unable to completely suppress all symptoms. A parallel effect emerged for ulcer-like and dyspepsia-like subgroups. The effect on heartburn and abdominal symptoms was not significant, suggesting a specific effect of the water on the gastric and duodenal wall. The Roma II criteria identify a natural kind of dyspepsia that improves with thermal water. Ulcer-like and dysmotility-like are not therapeutically distinguishable subgroups. Patients with dominant esophageal or abdominal symptoms should receive a different therapy. Sequential methods are very effective for the evaluation of traditional care practices and should be considered preliminary and integrative to randomized controlled trials in this context.

  12. Thermal Care of Functional Dyspepsia Based on Bicarbonate-Sulphate-Calcium Water: A Sequential Clinical Trial

    Science.gov (United States)

    Dioni, Federico; Rocca, Nadia; Oliveri, Filippo; Brunetto, Maurizia R; Bonino, Ferruccio

    2007-01-01

    Drug treatment of functional dyspepsia is often unsatisfactory. We assessed the efficacy of a bicarbonate-sulphate-calcium thermal water cycle of 12 days, in patients with functional dyspepsia. Patients with functional dyspepsia were sent by their general practitioners to 12 days of treatment with thermal water, 200–400 ml in the morning, at temperature of 33°C (91.4 F) and were evaluated on a strict intention to treat basis. Four efficacy endpoints were analyzed as follows: (i) reduction of the global symptoms score, (ii) reduction of intensity to a level not interfering with everyday activities, (iii) specific efficacy on ulcer-like or dysmotility-like dyspepsia and (iv) esophageal or abdominal-associated symptoms. Statistical significance was reached for all three primary outcomes after the first 29 consecutive patients. Thermal water reduced the global symptom score, reduced intensity of symptoms to a level not interfering with everyday activity, but was unable to completely suppress all symptoms. A parallel effect emerged for ulcer-like and dyspepsia-like subgroups. The effect on heartburn and abdominal symptoms was not significant, suggesting a specific effect of the water on the gastric and duodenal wall. The Roma II criteria identify a natural kind of dyspepsia that improves with thermal water. Ulcer-like and dysmotility-like are not therapeutically distinguishable subgroups. Patients with dominant esophageal or abdominal symptoms should receive a different therapy. Sequential methods are very effective for the evaluation of traditional care practices and should be considered preliminary and integrative to randomized controlled trials in this context. PMID:17965771

  13. Effects of sodium bicarbonate, caffeine, and their combination on repeated 200-m freestyle performance.

    Science.gov (United States)

    Pruscino, Cathryn L; Ross, Megan L R; Gregory, John R; Savage, Bernard; Flanagan, Troy R

    2008-04-01

    The purpose of this study was to investigate the effects of sodium bicarbonate (NaHCO(3)), caffeine, and their combination on repeated 200-m freestyle performance. Six elite male freestyle swimmers ingested NaHCO(3) (0.3 g/kg; B), caffeine (6.2 +/- 0.3 mg/kg; C), a combination of both (B+C), and placebo (P) on 4 separate occasions before completing 2 maximal 200-m freestyle time trials (TT1 and TT2) separated by 30 min. No significant differences (p = .06) were observed for performance in TT1 (B 2:03.01 +/- 0:03.68 min, C 2:02.42 +/- 0:03.17 min, B+C 2:01.69 +/- 0:03.19 min, P 2:03.77 +/- 0:03.21 min) or TT2 (B 2:02.62 +/- 0:04.16 min, C 2:03.90 +/- 0:03.58 min, B+C 2:01.70 +/- 0:02.84 min, P 2:04.22 +/- 0:03.75 min). The drop-off in performance time from TT1 to TT2, however, was significantly greater when C was ingested than with B (-1.5%, p = .002) or B+C (-1.2%, p = .024). This is likely because of the lower blood pH and slower recovery of blood HCO(3) post-TT1 after C ingestion. These findings suggest that the ergogenic benefit of taking C alone for repeated 200-m swimming performance appears limited. When combined with NaHCO(3), however, its negative impact on repeated maximal exercise performance is reversed.

  14. Salt sensitivity of blood pressure is associated with polymorphisms in the sodium-bicarbonate cotransporter.

    Science.gov (United States)

    Carey, Robert M; Schoeffel, Cynthia D; Gildea, John J; Jones, John E; McGrath, Helen E; Gordon, Lindsay N; Park, Min Jeong; Sobota, Rafal S; Underwood, Patricia C; Williams, Jonathan; Sun, Bei; Raby, Benjamin; Lasky-Su, Jessica; Hopkins, Paul N; Adler, Gail K; Williams, Scott M; Jose, Pedro A; Felder, Robin A

    2012-11-01

    Previous studies have demonstrated that single nucleotide polymorphisms (SNPs) of the sodium-bicarbonate co-transporter gene (SLC4A5) are associated with hypertension. We tested the hypothesis that SNPs in SLC4A5 are associated with salt sensitivity of blood pressure in 185 whites consuming an isocaloric constant diet with a randomized order of 7 days of low Na(+) (10 mmol/d) and 7 days of high Na(+) (300 mmol/d) intake. Salt sensitivity was defined as a ≥ 7-mm Hg increase in mean arterial pressure during a randomized transition between high and low Na(+) diet. A total of 35 polymorphisms in 17 candidate genes were assayed, 25 of which were tested for association. Association analyses with salt sensitivity revealed 3 variants that associated with salt sensitivity, 2 in SLC4A5 (P<0.001) and 1 in GRK4 (P=0.020). Of these, 2 SNPs in SLC4A5 (rs7571842 and rs10177833) demonstrated highly significant results and large effects sizes, using logistic regression. These 2 SNPs had P values of 1.0 × 10(-4) and 3.1 × 10(-4) with odds ratios of 0.221 and 0.221 in unadjusted regression models, respectively, with the G allele at both sites conferring protection. These SNPs remained significant after adjusting for body mass index and age (P=8.9 × 10(-5) and 2.6 × 10(-4) and odds ratios 0.210 and 0.286, respectively). Furthermore, the association of these SNPs with salt sensitivity was replicated in a second hypertensive population. Meta-analysis demonstrated significant associations of both SNPs with salt sensitivity (rs7571842 [P=1.2 × 10(-5)]; rs1017783 [P=1.1 × 10(-4)]). In conclusion, SLC4A5 variants are strongly associated with salt sensitivity of blood pressure in 2 separate white populations.

  15. The chronic toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2014-01-01

    Sodium bicarbonate (NaHCO3) is the principal salt in coal bed natural gas produced water from the Powder River Structural Basin, Wyoming, USA, and concentrations of up to 3000 mg NaHCO3/L have been documented at some locations. No adequate studies have been performed to assess the chronic effects of NaHCO3 exposure. The present study was initiated to investigate the chronic toxicity and define sublethal effects at the individual organism level to explain the mechanisms of NaHCO3 toxicity. Three chronic experiments were completed with fathead minnows (Pimephales promelas), 1 with white suckers (Catostomus commersoni), 1 with Ceriodaphnia dubia, and 1 with a freshwater mussel, (Lampsilis siliquoidea). The data demonstrated that approximately 500 mg NaHCO3/L to 1000 mg NaHCO3/L affected all species of experimental aquatic animals in chronic exposure conditions. Freshwater mussels were the least sensitive to NaHCO3 exposure, with a 10-d inhibition concentration that affects 20% of the sample population (IC20) of 952 mg NaHCO3/L. The IC20 for C. dubia was the smallest, at 359 mg NaHCO3/L. A significant decrease in sodium–potassium adenosine triphosphatase (Na+/K+ ATPase) together with the lack of growth effects suggests that Na+/K+ ATPase activity was shut down before the onset of death. Several histological anomalies, including increased incidence of necrotic cells, suggested that fish were adversely affected as a result of exposure to >450 mg NaHCO3/L.

  16. Bicarbonate blocks iron translocation from cotyledons inducing iron stress responses in Citrus roots.

    Science.gov (United States)

    Martínez-Cuenca, Mary-Rus; Legaz, Francisco; Forner-Giner, M Ángeles; Primo-Millo, Eduardo; Iglesias, Domingo J

    2013-07-01

    The effect of bicarbonate ion (HCO3(-)) on the mobilization of iron (Fe) reserves from cotyledons to roots during early growth of citrus seedlings and its influence on the components of the iron acquisition system were studied. Monoembryonic seeds of Citrus limon (L.) were germinated "in vitro" on two iron-deprived media, supplemented or not with 10mM HCO3(-) (-Fe+Bic and -Fe, respectively). After 21d of culture, Fe concentration in seedling organs was measured, as well as gene expression and enzymatic activities. Finally, the effect of Fe resupply on the above responses was tested in the presence and absence of HCO3(-) (+Fe+Bic or +Fe, respectively). -Fe+Bic seedlings exhibited lower Fe concentration in shoots and roots than -Fe ones but higher in cotyledons, associated to a significative inhibition of NRAMP3 expression. HCO3(-) upregulated Strategy I related genes (FRO1, FRO2, HA1 and IRT1) and FC-R and H(+)-ATPase activities in roots of Fe-starved seedlings. PEPC1 expression and PEPCase activity were also increased. When -Fe+Bic pre-treated seedlings were transferred to Fe-containing media for 15d, Fe content in shoots and roots increased, although to a lower extent in the +Fe+Bic medium. Consequently, the above-described root responses became markedly repressed, however, this effect was less pronounced in +Fe+Bic seedlings. In conclusion, it appears that HCO3(-) prevents Fe translocation from cotyledons to shoot and root, therefore reducing their Fe levels. This triggers Fe-stress responses in the root, enhancing the expression of genes related with Fe uptake and the corresponding enzymatic activities.

  17. Effect of preozonation on the characteristic transformation of fulvic acid and its subsequent trichloromethane formation potential: presence or absence of bicarbonate.

    Science.gov (United States)

    Li, Jing; Liu, Huijuan; Zhao, Xu; Qu, Jiuhui; Liu, Ruiping; Ru, Jia

    2008-04-01

    The effects of bicarbonate on the characteristic transformation of fulvic acid (FA) and its subsequent trichloromethane formation potential (TCMFP) were investigated in the process of preozonation. Dissolved organic carbon (DOC) removal rate and the residual aqueous ozone concentration during preozonation were measured with different bicarbonate concentration. The presence of bicarbonate inhibited DOC removal and decreased TCMFP yields in the initial oxidation period. In order to explain these phenomena, the molecular weight (MW) distribution (30 kDa) and corresponding TCMFP were investigated for FA and its subsequent oxidation products. Furthermore, transformation of molecular structure, based on MW distribution, was also characterized with Fourier transform infrared (FTIR) spectrum. Bicarbonate showed different inhibiting effects on TCMFP of organic species with different MW, and more significant TCMFP decrement was observed for the high MW fraction (>30 kDa) than for the low MW fractions. Preozonation led to obvious reduction on DOC and UV254 in most of MW fractions wherever bicarbonate was present or not, demonstrating that ozone contributed to both organics mineralization and structure variation, synchronously. As being indicated from the results of FTIR and gas chromatography-mass spectrometry, the functional groups such as alcohols, epoxides and phenols, the formation of which was promoted with hydroxyl radicals (.OH) and would be remarkably inhibited by bicarbonate, were responsible for the increment of TCM precursor's concentration during ozonation. Results of these studies confirmed low dosage bicarbonate affecting the ozonation pathways, influencing the intermediate species formation and impacting its subsequent TCMFP yields through inhibiting the .OH radicals reactions mainly occurred in high MW fractions.

  18. Magnesium bicarbonate and carbonate interactions in aqueous solutions: An infrared spectroscopic and quantum chemical study

    Science.gov (United States)

    Stefánsson, Andri; Lemke, Kono H.; Bénézeth, Pascale; Schott, Jacques

    2017-02-01

    The interaction of magnesium with bicarbonate and carbonate ions in aqueous solutions was studied using infrared spectroscopy and quantum chemical calculations. Using the infrared vibrational bands for HCO3- and CO32- at 1200-1450 cm-1 (δC-OH, vS and v3) together with their molar absorptivity (ε), the concentrations of the HCO3- and CO32- ions and the corresponding Mg ion pairs have been determined. In the absence of Mg2+, measured spectra were accurately reproduced assuming that only HCO3- and CO32- were present in solution. Upon addition of Mg2+ at fixed pH, infrared spectra were observed to shift indicating presence of the MgHCO3+ and MgCO3 (aq) ion pairs. From measurements, the second ionization constant of carbonic acid and the MgHCO3+ and MgCO3 (aq) ion pair formation constants have been obtained, these being logK2 = -10.34 ± 0.04, logKMgHCO3+ = 1.12 ± 0.11 and logKMgCO3 = 2.98 ± 0.06, respectively. To support our experimental infrared measurements and to gain further insight into the molecular nature of the ion pair formation, density functional theory (DFT) calculations with VPT2 anharmonic correction were conducted. The most stable geometries predicted for the MgHCO3+ and MgCO3 (aq) ion pairs were a bi-dentate [MgHCO3]+(H2O)n and a monodentate [MgHCO3]+(OH)(H2O)n complexes, respectively. The predicted frequencies for HCO3-, CO32- and MgHCO3+ were found to shift toward those experimentally measured with an increasing H2O solvation number where possible band shifts were predicted for MgCO3 (aq) relative to CO32-, this being dependent on the exact structure and hydration of the bulk MgCO3 (aq) ion pair. Experimentally, the ion pair formations were found to have insignificant effects on the δC-OH, vS and v3 vibrational frequencies. The speciation of dissolved inorganic carbon may be significantly influenced by ion pair formation, particularly in alkaline solutions where they may be the predominant species.

  19. The effect of sodium bicarbonate ingestion on back squat and bench press exercise to failure.

    Science.gov (United States)

    Duncan, Michael J; Weldon, Anthony; Price, Michael J

    2014-05-01

    This study examined the acute effects of NaHCO3 ingestion on repetitions to failure and rating of perceived exertion in the back squat and bench press in trained men. Eight resistance-trained men took part in this double-blind, randomized crossover experimental study whereby they ingested NaHCO3 (0.3 g·kg(-1) body mass) or placebo (sodium chloride NaCl: 0.045 g·kg(-1) body mass) solution 60 minutes before completing a bout of resistance exercise (3 sets of bench press and back squat exercise to failure at an intensity of 80% 1 repetition maximum). Experimental conditions were separated by at least 48 hours. Participants completed more repetitions to failure in the back squat after NaHCO3 ingestion (p = 0.04) but not for bench press (p = 0.679). Mean ± SD of total repetitions was 31.3 ± 15.3 and 24.6 ± 16.2 for back squat and 28.7 ± 12.2 and 26.7 ± 10.2 for bench press in NaHCO3 and placebo conditions, respectively. Repetitions to failure decreased as set increased for the back squat and bench press (p = 0.001, both). Rating of perceived exertion significantly increased with set for the back squat and bench press (p = 0.002, both). There was no significant change in blood lactate across time or between conditions. There were however treatment × time interactions for blood pH (p = 0.014) and blood HCO3 concentration (p = 0.001). After ingestion, blood pH and HCO3 (p = 0.008) concentrations were greater for the NaHCO3 condition compared with the placebo condition (p < 0.001). The results of this study suggest that sodium bicarbonate ingestion can enhance resistance exercise performance using a repetition to failure protocol in the first exercise in a resistance exercise session.

  20. In vitro dissolution of proton-pump inhibitor products intended for paediatric and geriatric use in physiological bicarbonate buffer.

    Science.gov (United States)

    Liu, Fang; Shokrollahi, Honaz

    2015-05-15

    Proton-pump inhibitor (PPI) products based on enteric coated multiparticulates are design to meet the needs of patients who cannot swallow tablets such as children and older adults. Enteric coated PPI preparations exhibit delays in in vivo absorption and onset of antisecretory effects, which is not reflected by the rapid in vitro dissolution in compendial pH 6.8 phosphate buffer commonly used for assessment of these products. A more representative and physiological medium, pH 6.8 mHanks bicarbonate buffer, was used in this study to evaluate the in vitro dissolution of enteric coated multiparticulate-based PPI products. Commercially available omeprazole, lansoprazole and esomeprazole products were subject to dissolution tests using USP-II apparatus in pH 4.5 phosphate buffer saline for 45 min (acid stage) followed by pH 6.8 phosphate buffer or pH 6.8 mHanks bicarbonate buffer. In pH 6.8 phosphate buffer, all nine tested products displayed rapid and comparable dissolution profiles meeting the pharmacopeia requirements for delayed release preparations. In pH 6.8 mHanks buffer, drug release was delayed and failed the pharmacopeia requirements from most enteric coated preparations. Despite that the same enteric polymer, methacrylic acid-ethyl acrylate copolymer (1:1), was applied to all commercial multiparticulate-based products, marked differences were observed between dissolution profiles of these preparations. The use of pH 6.8 physiological bicarbonate (mHanks) buffer can serve as a useful tool to provide realistic and discriminative in vitro release assessment of enteric coated PPI preparations and to assist rational formulation development of these products.

  1. Effect of Electrochemical Treatment in Aqueous Ammonium Bicarbonate on Surface Properties of PAN-based Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    曹海琳; 黄玉东; 张志谦; 孙举涛

    2004-01-01

    The surface properties of PAN-based carbon fibers electrochemically treated in aqueous ammonium bicarbonate before and after treatment were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Dynamic Contact Angle Analysis (DCAA). The results of characterization indicated that the oxygen and nitrogen contents in carbon fiber surface were significantly increased by electrochemical treatment, and amide groups was introduced onto it, which was related with the electrolyte. The AFM photographs illustrated that the roughness of the fiber surface was also increased. The wettibality of the fibers was improved after treatment because the surface energy especially the polar part of it was increased.

  2. Effects of sodium bicarbonate concentration on growth, photosynthesis, and carbonic anhydrase activity of macroalgae Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae (Gracilariales, Rhodophyta).

    Science.gov (United States)

    Zhou, Wei; Sui, Zhenghong; Wang, Jinguo; Hu, Yiyi; Kang, Kyoung Ho; Hong, Hye Ran; Niaz, Zeeshan; Wei, Huihui; Du, Qingwei; Peng, Chong; Mi, Ping; Que, Zhou

    2016-06-01

    There is potential for bicarbonate to improve crop yields and economic efficiency of marine algae. However, few studies have focused on the effect of bicarbonate on the growth, photosynthesis, and enzyme activity associated with carbon utilization, especially in commercial macroalgae. Here, the addition of bicarbonate (up to 420 mg L(-1)) to macroalgal cultures has been evaluated for Gracilariopsis lemaneiformis, Gracilaria vermiculophylla, and Gracilaria chouae with respect to growth rate, photosynthetic activity, carbonic anhydrase activity, and biochemical composition. The results showed that the effects of NaHCO3 on growth, chlorophyll a, phycoerythrin, photosynthetic oxygen evolution, photochemical parameters of PSI and PSII, carbonic anhydrase activity, and nitrogen content were significant (P 336 mg L(-1) for Gp. lemaneiformis and >420 mg L(-1) for the other two species). Moreover, species-specific differences induced by supplementation with bicarbonate were discovered during culture. Optimal concentrations of NaHCO3 used in this study were 252 mg L(-1) for Gp. lemaneiformis and 336 mg L(-1) for G. vermiculophylla and G. chouae. These results suggest that an adequate supplementation of sodium bicarbonate is a viable strategy for promoting growth and photosynthetic activity in some macroalgae as well as for improving biochemical composition. The study will help to accelerate the growth rate of algae and improve the quality of thalli, and will also be useful for enhancing the understanding of carbon utilization in macroalgae.

  3. Formate-Dependent Microbial Conversion of CO2 and the Dominant Pathways of methanogenesis in production water of high-temperature oil reservoirs amended with bicarbonate

    Directory of Open Access Journals (Sweden)

    Guang-Chao eYang

    2016-03-01

    Full Text Available CO2 sequestration in deep-subsurface formations including oil reservoirs is a potential measure to reduce the CO2 concentration in the atmosphere. However, the fate of the CO2 and the ecological influences in Carbon Dioxide Capture and Storage (CDCS facilities is not understood clearly. In the current study, the fate of CO2 (in bicarbonate form (0~90 mM with 10 mM of formate as electron donor and carbon source was investigated with high-temperature production water from oilfield in China. The isotope data showed that bicarbonate could be reduced to methane by methanogens and major pathway of methanogenesis could be syntrophic formate oxidation coupled with CO2 reduction and formate methanogenesis under the anaerobic conditions. The bicarbonate addition induced the shift of microbial community. Addition of bicarbonate and formate was associated with a decrease of Methanosarcinales, but promotion of Methanobacteriales in all treatments. Thermodesulfovibrio was the major group in all the samples and Thermacetogenium dominated in the high bicarbonate treatments. The results indicated that CO2 from CDCS could be transformed to methane and the possibility of microbial CO2 conversion for enhanced microbial energy recovery in oil reservoirs.

  4. Effects of some organic materials on bicarbonate extractable phosphate content of soils having different pH

    Directory of Open Access Journals (Sweden)

    Nutullah Özdemir

    2016-10-01

    Full Text Available This study was carried out to determine the effects of rice husk compost (RC, town waste compost (TW and tobacco waste (TB on bicarbonate extractable phosphate content (P in soils having different pH levels under greenhouse conditions. Soil samples used in this study were taken from surfaces (0-20 cm of agricultural fields around Samsun, Northern Anatolia. The experiment was conducted according to split plot design with four doses of organic matterials (0, 2.5, 5.0 and 7.5, %. After a month of mixing organic matterials into soils, lettuce were grown in the medias. According to the results, RC, TW and TB applications into acidic (Tepecik, neutral (Kampüs and alkaline (Çetinkaya soils increased extractable P content. It was observed that effectiveness of organic matterials changed depend on soil reaction, type and dose of organic matterials. All organic wastes were more effective on increment of bicarbonate extractable phosphate content in neutral soil pH when compared the other soil pH levels.

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

    KAUST Repository

    Hatzell, Marta C.

    2013-11-01

    Ammonium bicarbonate has recently been demonstrated to be an excellent thermolytic solution for energy generation in reverse electrodialysis (RED) stacks. However, operating RED stacks at room temperatures can promote gaseous bubble (CO2, NH3) accumulation within the stack, reducing overall system performance. The management and minimization of bubbles formed in RED flow fields is an important operational issue which has yet to be addressed. Flow fields with and without spacers in RED stacks were analyzed to determine how both fluid flow and the buildup and removal of bubbles affected performance. In the presence of a spacer, the membrane resistance increased by ~50Ω, resulting in a decrease in power density by 30% from 0.140Wm-2 to 0.093Wm-2. Shorter channels reduced concentration polarization affects, and resulted in 3-23% higher limiting current density. Gas accumulation was minimized through the use of short vertically aligned channels, and consequently the amount of the membrane area covered by bubbles was reduced from ~20% to 7% which caused a 12% increase in power density. As ammonium bicarbonate RED systems are scaled up, attention to channel aspect ratio, length, and alignment will enable more stable performance. © 2013 Elsevier B.V.

  6. Elucidation of the bicarbonate binding site and insights into the carboxylation mechanism of (N(5))-carboxyaminoimidazole ribonucleotide synthase (PurK) from Bacillus anthracis.

    Science.gov (United States)

    Tuntland, Micheal L; Santarsiero, Bernard D; Johnson, Michael E; Fung, Leslie W M

    2014-11-01

    Structures of (N(5))-carboxyaminoimidazole ribonucleotide synthase (PurK) from Bacillus anthracis with various combinations of ATP, ADP, Mg(2+), bicarbonate and aminoimidazole ribonucleotide (AIR) in the active site are presented. The binding site of bicarbonate has only been speculated upon previously, but is shown here for the first time. The binding involves interactions with the conserved residues Arg272, His274 and Lys348. These structures provide insights into each ligand in the active site and allow a possible mechanism to be proposed for the reaction that converts bicarbonate and AIR, in the presence of ATP, to produce (N(5))-carboxyaminoimidazole ribonucleotide. The formation of a carboxyphosphate intermediate through ATP phosphoryl transfer is proposed, followed by carboxylation of AIR to give the product, facilitated by a cluster of conserved residues and an active-site water network.

  7. Mechanisms of pH-gradient driven transport mediated by organic anion polypeptide transporters.

    Science.gov (United States)

    Leuthold, Simone; Hagenbuch, Bruno; Mohebbi, Nilufar; Wagner, Carsten A; Meier, Peter J; Stieger, Bruno

    2009-03-01

    Organic anion transporting polypeptides (humans OATPs, rodents Oatps) are expressed in most mammalian tissues and mediate cellular uptake of a wide variety of amphipathic organic compounds such as bile salts, steroid conjugates, oligopeptides, and a large list of drugs, probably by acting as anion exchangers. In the present study we aimed to investigate the role of the extracellular pH on the transport activity of nine human and four rat OATPs/Oatps. Furthermore, we aimed to test the concept that OATP/Oatp transport activity is accompanied by extrusion of bicarbonate. By using amphibian Xenopus laevis oocytes expressing OATPs/Oatps and mammalian cell lines stably transfected with OATPs/Oatps, we could demonstrate that in all OATPs/Oatps investigated, with the exception of OATP1C1, a low extracellular pH stimulated transport activity. This stimulation was accompanied by an increased substrate affinity as evidenced by lower apparent Michaelis-Menten constant values. OATP1C1 is lacking a highly conserved histidine in the third transmembrane domain, which was shown by site-directed mutagenesis to be critically involved in the pH dependency of OATPs/Oatps. Using online intracellular pH measurements in OATP/Oatp-transfected Chinese Hamster Ovary (CHO)-K1 cells, we could demonstrate the presence of a 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid-sensitive chloride/bicarbonate exchanger in CHO-K1 cells and that OATP/Oatp-mediated substrate transport is paralleled by bicarbonate efflux. We conclude that the pH dependency of OATPs/Oatps may lead to a stimulation of substrate transport in an acidic microenvironment and that the OATP/Oatp-mediated substrate transport into cells is generally compensated or accompanied by bicarbonate efflux.

  8. Successful recovery from iatrogenic severe hypernatremia and severe metabolic acidosis resulting from accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment

    Directory of Open Access Journals (Sweden)

    Guruprasad P Bhosale

    2015-01-01

    Full Text Available Bicarbonate dialysis is the treatment modality of choice for correction of metabolic acidosis in chronic renal failure. However, improper selection of dialysate concentrate can result in life-threatening human errors. We report a case of iatrogenic severe hypernatremia (sodium 207 mEq/L and severe metabolic acidosis (pH 6.65 that resulted due to accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment. There was successful recovery in this patient with no neurological sequelae. To the best of our knowledge, this is the first case report in adults of severe hypernatremia along with severe metabolic acidosis due to error in the preparation of dialysis fluid.

  9. Mediatized Humanitarianism

    DEFF Research Database (Denmark)

    Vestergaard, Anne

    2014-01-01

    The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts to legiti......The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts...... legitimation by accountancy, legitimation by institutionalization, and legitimation by compensation. The analysis relates these changes to a problem of trust associated with mediatization through processes of mediation....

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

    KAUST Repository

    Hatzell, Marta C.

    2014-01-01

    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.

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

    Science.gov (United States)

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

    2014-01-28

    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.

  12. The ethanol-induced stimulation of rat duodenal mucosal bicarbonate secretion in vivo is critically dependent on luminal Cl-.

    Directory of Open Access Journals (Sweden)

    Anna Sommansson

    Full Text Available Alcohol may induce metabolic and functional changes in gastrointestinal epithelial cells, contributing to impaired mucosal barrier function. Duodenal mucosal bicarbonate secretion (DBS is a primary epithelial defense against gastric acid and also has an important function in maintaining the homeostasis of the juxtamucosal microenvironment. The aim in this study was to investigate the effects of the luminal perfusion of moderate concentrations of ethanol in vivo on epithelial DBS, fluid secretion and paracellular permeability. Under thiobarbiturate anesthesia, a ∼30-mm segment of the proximal duodenum with an intact blood supply was perfused in situ in rats. The effects on DBS, duodenal transepithelial net fluid flux and the blood-to-lumen clearance of 51Cr-EDTA were investigated. Perfusing the duodenum with isotonic solutions of 10% or 15% ethanol-by-volume for 30 min increased DBS in a concentration-dependent manner, while the net fluid flux did not change. Pre-treatment with the CFTR inhibitor CFTRinh172 (i.p. or i.v. did not change the secretory response to ethanol, while removing Cl- from the luminal perfusate abolished the ethanol-induced increase in DBS. The administration of hexamethonium (i.v. but not capsazepine significantly reduced the basal net fluid flux and the ethanol-induced increase in DBS. Perfusing the duodenum with a combination of 1.0 mM HCl and 15% ethanol induced significantly greater increases in DBS than 15% ethanol or 1.0 mM HCl alone but did not influence fluid flux. Our data demonstrate that ethanol induces increases in DBS through a mechanism that is critically dependent on luminal Cl- and partly dependent on enteric neural pathways involving nicotinic receptors. Ethanol and HCl appears to stimulate DBS via the activation of different bicarbonate transporting mechanisms.

  13. Changes in the quality of life of patients with end-stage renal disease treated with high-efficiency bicarbonate hemodialysis in Mexico.

    Science.gov (United States)

    De Icaza, E; Arredondo, A; Calderon, C; Hernandez, G

    1997-01-01

    In accordance with the epidemiological changes in Mexico, the results of this study are intended to contribute to the evaluation of the end-stage renal disease (ESRD) program of the health services in Mexico. We measured the quality of life of 21 ESRD patients before and after 6 months of exposure to treatment with high-efficiency hemodialysis with bicarbonate (HEHD/bicarbonate). We cross-sectionally assessed the Quality Adjusted Life Year (QALY) index and the biochemical status of the subject pool. The QALY score for patients undergoing HEHD/bicarbonate after 6 months was significantly higher than with the previous dialysis modality (0.95 and 0.74, respectively, p = 0.02). The marked similarities of the biochemical status variables indicated there was little or no effect in the improvement of the quality of life of patients. Dialysis modality likely exerts an important influence on the quality of life of chronic dialysis patients; thus we believe HEHD/bicarbonate does offer greater benefits than hemodialysis alone. Longitudinal studies are needed to better ascertain the effect of the case mix, the treatment approach, and the characteristics of the dialysis in relation to the improvement of the quality of life of ESRD patients.

  14. Complex Mediation

    DEFF Research Database (Denmark)

    Bødker, Susanne; Andersen, Peter Bøgh

    2005-01-01

    This article has its starting point in a large number of empirical findings regarding computer-mediated work. These empirical findings have challenged our understanding of the role of mediation in such work; on the one hand as an aspect of communication and cooperation at work and on the other hand...... as an aspect of human engagement with instruments of work. On the basis of previous work in activity-theoretical and semiotic human—computer interaction, we propose a model to encompass both of these aspects. In a dialogue with our empirical findings we move on to propose a number of types of mediation...... that have helped to enrich our understanding of mediated work and the design of computer mediation for such work....

  15. Effects of gas composition in headspace and bicarbonate concentrations in media on gas and methane production, degradability, and rumen fermentation using in vitro gas production techniques.

    Science.gov (United States)

    Patra, Amlan Kumar; Yu, Zhongtang

    2013-07-01

    Headspace gas composition and bicarbonate concentrations in media can affect methane production and other characteristics of rumen fermentation in in vitro gas production systems, but these 2 important factors have not been evaluated systematically. In this study, these 2 factors were investigated with respect to gas and methane production, in vitro digestibility of feed substrate, and volatile fatty acid (VFA) profile using in vitro gas production techniques. Three headspace gas compositions (N2+ CO2+ H2 in the ratio of 90:5:5, CO2, and N2) with 2 substrate types (alfalfa hay only, and alfalfa hay and a concentrate mixture in a 50:50 ratio) in a 3×2 factorial design (experiment 1) and 3 headspace compositions (N2, N2 + CO2 in a 50:50 ratio, and CO2) with 3 bicarbonate concentrations (80, 100, and 120 mM) in a 3×3 factorial design (experiment 2) were evaluated. In experiment 1, total gas production (TGP) and net gas production (NGP) was the lowest for CO2, followed by N2, and then the gas mixture. Methane concentration in headspace gas after fermentation was greater for CO2 than for N2 and the gas mixture, whereas total methane production (TMP) and net methane production (NMP) were the greatest for CO2, followed by the gas mixture, and then N2. Headspace composition did not affect in vitro digestibility or the VFA profile, except molar percentages of propionate, which were greater for CO2 and N2 than for the gas mixture. Methane concentration in headspace gas, TGP, and NGP were affected by the interaction of headspace gas composition and substrate type. In experiment 2, increasing concentrations of CO2 in the headspace decreased TGP and NGP quadratically, but increased the concentrations of methane, NMP, and in vitro fiber digestibility linearly, and TMP quadratically. Fiber digestibility, TGP, and NGP increased linearly with increasing bicarbonate concentrations in the medium. Concentrations of methane and NMP were unaffected by bicarbonate concentration, but

  16. Enhanced short-cut nitrification in an airlift reactor by CaCO3 attachment on biomass under high bicarbonate condition.

    Science.gov (United States)

    Ali, Mohammad; Chai, Li-Yuan; Wang, Hai-Ying; Tang, Chong-Jian; Min, Xiao-Bo; Yan, Xu; Peng, Cong; Song, Yu-Xia; Zheng, Ping

    2016-06-01

    The short-cut nitrification (SCN) performance of an airlift reactor (ALR) was investigated under increasing bicarbonate condition. The sequential increase of bicarbonate from 2.5 to 7.0 g/L accelerated the nitrite accumulation and improved the NAP to 99 %. With the increase of bicarbonate dose to 11 g/L, the ammonium removal efficiency and the ammonium removal rate (ARR) were improved to 95.1 % and 0.57 kg/m(3)/day, respectively. However, the elevation of bicarbonate concentration from 11.0 to 14.0 g/L gradually depreciated the nitrite accumulation percentage to 62.5 %. Then, the reactor was operated in increasing ammonium strategy to increase the nitrogen loading rate (NLR) to 1.1 kg/m(3)/day under 700 mg/L influent ammonium concentration. The ARR and nitrite production rate were elevated to 1.1 and 0.9 kg/m(3)/day, respectively. The SCN performance was improved to 1.8 kg/m(3)/day (NLR) by the subsequent progressive shortening of HRT to 4.8 h at ammonium concentration of 350 mg/L, which was 1.6 times higher than that of the increasing ammonium strategy. Chemical analysis with EDS, FTIR and XRD confirmed the presence of CaCO3 precipitates on biomass surface during the long-term operation under high bicarbonate conditions. The attachment of precipitates to the SCN sludge helped to improve the biomass settleability and finally enhanced the SCN performance of the ALR.

  17. Cellular chloride and bicarbonate retention alters intracellular pH regulation in Cftr KO crypt epithelium.

    Science.gov (United States)

    Walker, Nancy M; Liu, Jinghua; Stein, Sydney R; Stefanski, Casey D; Strubberg, Ashlee M; Clarke, Lane L

    2016-01-15

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR), an anion channel providing a major pathway for Cl(-) and HCO3 (-) efflux across the apical membrane of the epithelium. In the intestine, CF manifests as obstructive syndromes, dysbiosis, inflammation, and an increased risk for gastrointestinal cancer. Cftr knockout (KO) mice recapitulate CF intestinal disease, including intestinal hyperproliferation. Previous studies using Cftr KO intestinal organoids (enteroids) indicate that crypt epithelium maintains an alkaline intracellular pH (pHi). We hypothesized that Cftr has a cell-autonomous role in downregulating pHi that is incompletely compensated by acid-base regulation in its absence. Here, 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein microfluorimetry of enteroids showed that Cftr KO crypt epithelium sustains an alkaline pHi and resistance to cell acidification relative to wild-type. Quantitative real-time PCR revealed that Cftr KO enteroids exhibit downregulated transcription of base (HCO3 (-))-loading proteins and upregulation of the basolateral membrane HCO3 (-)-unloader anion exchanger 2 (Ae2). Although Cftr KO crypt epithelium had increased Ae2 expression and Ae2-mediated Cl(-)/HCO3 (-) exchange with maximized gradients, it also had increased intracellular Cl(-) concentration relative to wild-type. Pharmacological reduction of intracellular Cl(-) concentration in Cftr KO crypt epithelium normalized pHi, which was largely Ae2-dependent. We conclude that Cftr KO crypt epithelium maintains an alkaline pHi as a consequence of losing both Cl(-) and HCO3 (-) efflux, which impairs pHi regulation by Ae2. Retention of Cl(-) and an alkaline pHi in crypt epithelium may alter several cellular processes in the proliferative compartment of Cftr KO intestine.

  18. 141 BOVINE EMBRYO DEVELOPMENT RATES ARE AFFECTED WHEN OOCYTES ARE MATURED IN DIFFERENT VIALS CONTAINING HEPES/BICARBONATE BUFFERED MEDIUM.

    Science.gov (United States)

    Hashem, N; Secher, J O; Pryor, J H; Long, C R; Looney, C R; Avery, B; Hyttel, P; Stroebech, L

    2016-01-01

    Laboratory ware for the in vitro-produced embryos is generally made from embryo-tested plastic instead of glass. The quality of the plastic is crucial for the outcome because plastic is often toxic to gametes (Nijs et al. 2009 Fertil. Steril. 92, 527-535). In addition, gas molecules permeate through the plastic at a rate that depends on a variety of factors, such as diffusion coefficient and thickness of the plastic. In an incubator with appropriate concentration of CO2 and vented culture vessels, the gas permeability of the plastic is not important. When oocytes are transported outside a controlled atmosphere, gas permeability, toxicity, and oocyte cumulus cell CO2 metabolism could perturb the outcome. Medium containing bicarbonate buffer increases pH outside of a controlled atmosphere within minutes, whereas medium buffered with HEPES maintains suitable pH for hours. Previously, we tested that gas permeability differs among plastic vials and glass vials with no cumulus-oocyte complexes (COC) by measuring pH after 2, 5, and 24h at the same temperature. The objective of this study was to compare pH post-maturation, blastocyst development rates on Day 8 post-IVF (Day 0=IVF) between 2 different 1.2-mL polypropylene cryovials (A: VWR DK, 479-1219; B: Sigma-Aldrich, St. Louis, MO, USA, CLS430289), glass vial (VWR DK, NSCAC4015-96), and 4-well plate (4WP) as control (Thermo Fisher Scientific, Waltham, MA, USA, 144444). A total of 1135 abattoir-derived COC in Exp. 1 and 133 in Exp. 2 were divided equally between the treatments (20-25 COC per vessel). Vials/4WP contained 0.8/0.5mL of BO-IVM HEPES, a HEPES/bicarbonate medium (IVF Bioscience; BO-HEPES-IVM, UK). Maturation lasted 22 to 24h at 38.8°C in an incubator with either a humidified atmosphere of 5.5% CO2 in air (Exp. 1) or with no CO2 contact (Exp. 2). In Exp. 1, oocyte vials were matured without a vial lid while in Exp. 2 vial lids were closed. Statistical analysis was performed with chi-square and mean±SD. In Exp

  19. Effect of glandular kallikrein on distal bicarbonate transport. Role of basolateral Cl-/HCO3- exchanger and vacuolar H(+)-ATPase.

    Science.gov (United States)

    Manucha, W; Vallés, P

    1999-12-01

    The luminal membrane of collecting duct cells, specially the intercalated cells, is normally exposed to active kallikrein. This is due to the specific localization of renal kallikrein in the connecting tubule cells. We have previously reported inhibition of distal bicarbonate secretion by renal kallikrein. The present study was performed to evaluate the participation of basolateral Cl-/HCO3- exchanger and luminal H(+)-ATPase activity of cortical collecting duct segments (CCD) in the mechanism involved in the inhibition of bicarbonate secretion induced by the enzyme. The effect of orthograde injections of 1 microgram/ml (250 U/6.3 mg) pig pancreatic kallikrein, in the absence and presence of 1 mM DIDS (stilbene-disulfonic acid) in the renal tubule system, was evaluated. Urine fractions were collected after two-minutes stop-flow. Changes in the urine fraction (Fr) related to those in free-flow urine samples (Ff) were related to the respective polyfructosan (Inutest) ratio. Renal kallikrein activity (Fr:Ff kallikrein/Fr:Ff polyfructosan) increased significantly in the first 120 microliters urine fraction collected after glandular 1 microgram/ml kallikrein, P Bicarbonate secretion rate (Fr:Ff HCO3-/Fr:Ff polyfructosan) of collecting ducts was significantly reduced in the first 120 microliters urine fraction collected, related to control, during the first and second stop-flow periods. No difference was shown in bicarbonate excretion between the first 120 microliters urine fractions collected after administration of glandular kallikrein and glandular kallikrein plus DIDS. To measure H(+)-ATPase activity, rat microdissected cortical collector tubules (CCD) were incubated in the presence of increasing glandular kallikrein doses (A: 93, B: 187 and C: 375 mU/200 microL) in the presence of ouabain (4 microM) and omeprazole (100 microM) to inhibit Na(+)-K(+)-ATPase and H(+)-K(+)-ATPase, respectively. In CCD, bafilomycin-sensitive H(+)-ATPase activity (pmol/mm/min) after

  20. Axion Mediation

    CERN Document Server

    Baryakhtar, Masha; March-Russell, John

    2013-01-01

    We explore the possibility that supersymmetry breaking is mediated to the Standard Model sector through the interactions of a generalized axion multiplet that gains a F-term expectation value. Using an effective field theory framework we enumerate the most general possible set of axion couplings and compute the Standard Model sector soft-supersymmetry-breaking terms. Unusual, non-minimal spectra, such as those of both natural and split supersymmetry are easily implemented. We discuss example models and low-energy spectra, as well as implications of the particularly minimal case of mediation via the QCD axion multiplet. We argue that if the Peccei-Quinn solution to the strong-CP problem is realized in string theory then such axion-mediation is generic, while in a field theory model it is a natural possibility in both DFSZ- and KSVZ-like regimes. Axion mediation can parametrically dominate gravity-mediation and is also cosmologically beneficial as the constraints arising from axino and gravitino overproduction ...

  1. Mediatized Parenthood

    DEFF Research Database (Denmark)

    Sonne Damkjær, Maja

    2017-01-01

    to parenthood? The dissertation explores this question on the basis of a synchronous study within an overall mediatization perspective. The first part of the dissertation focuses on a conceptualization of the relationship between digital media and parenting as well as an exploration of theoretical perspectives...... and methods that make it possible to study the interactions between the two. Concretely, the dissertation builds on a number of key studies within audience research, which have contributed knowledge about the media’s role in the family and the home. This is done by including three approaches to mediatization......) a family-oriented, b) a peer-oriented, c) an oppositional, and d) non-use. Secondary contribution: Based on qualitative audience research and mediatization theory, the dissertation contributes a conceptualization of the relationship between media and parenthood. This is carried out in a study design...

  2. Effects of sodium bicarbonate ingestion on performance and perceptual responses in a laboratory-simulated BMX cycling qualification series.

    Science.gov (United States)

    Zabala, Mikel; Requena, Bernardo; Sánchez-Muñoz, Cristóbal; González-Badillo, Juan José; García, Inmaculada; Oöpik, Vahur; Pääsuke, Mati

    2008-09-01

    The objective of this study was to examine the effect of sodium bicarbonate (NaHCO3-) ingestion on performance and perceptual responses in a laboratory-simulated bicycle motocross (BMX) qualification series. Nine elite BMX riders volunteered to participate in this study. After familiarization, subjects undertook two trials involving repeated sprints (3 x Wingate tests [WTs] separated by 30 minutes of recovery; WT1, WT2, WT3). Ninety minutes before each trial, subjects ingested either NaHCO3- or placebo in a counterbalanced, randomly assigned, double-blind manner. Each trial was separated by 4 days. Performance variables of peak power, mean power, time to peak power, and fatigue index were calculated for each sprint. Ratings of perceived exertion were obtained after each sprint, and ratings of perceived readiness were obtained before each sprint. No significant differences were observed in performance variables between successive sprints or between trials. For the NaHCO3- trial, peak blood lactate during recovery was greater after WT2 (p BMX qualification series, possibly because of the short duration of each effort and the long recovery time used between the three WTs. On the contrary, NaHCO3- ingestion improved perceived readiness before each WT.

  3. Physical and chemical properties of a durably efficacious ammonium bicarbonate as a fertilizer and its yield-increasing mechanism

    Institute of Scientific and Technical Information of China (English)

    张志明; 李继云; 冯元琦; 毕庶春; 伍蔚民

    1997-01-01

    A new fertilizer of cocrystal type,known as durably efficacious ammonium bicarbonate (DEAB),has been developed by adding a certain amount of dicyandiamide (DCD) as an ammonia-stabilizing agent to ammonium bearbenate(AB)during the process of its production.As compared with AB,DEAB was found to have a reduction of direct volatilization loss by 53%,a fertilizer availability period prolonged from 35-45 to 90-110 d,and an increase in the rate of nitrogen in fertilizer being utilized by 5.9%-10.2%,and a saving of the amount of fertilizer to be ap-phed by 20%-30% for the same level of yield,or an increase of the crop yield by over 10% for the same level of ni-tregen fertilization;in addition,it was found to show usually a function of promoting the crop to early mature.It can be apptied as basal dressing all in one time to soil and thus also used as a labour-saving and crop yield-increasing fertil-izer for is non-mtertillage,plastics film covering and water-saving agriculture

  4. Whey protein with potassium bicarbonate supplement attenuates the reduction in muscle oxidative capacity during 19 days of bed rest.

    Science.gov (United States)

    Bosutti, Alessandra; Salanova, Michele; Blottner, Dieter; Buehlmeier, Judith; Mulder, Edwin; Rittweger, Jörn; Yap, Moi Hoon; Ganse, Bergita; Degens, Hans

    2016-10-01

    The effectiveness of whey protein plus potassium bicarbonate-enriched diet (WP+KHCO3) in mitigating disuse-induced changes in muscle fiber oxidative capacity and capillarization was investigated in a 21-day crossover design bed rest study. Ten healthy men (31 ± 6 yr) once received WP+KHCO3 and once received a standardized isocaloric diet. Muscle biopsies were taken 2 days before and during the 19th day of bed rest (BR) from the soleus (SOL) and vastus lateralis (VL) muscle. Whole-body aerobic power (V̇o2 max), muscle fatigue, and isometric strength of knee extensor and plantar flexor muscles were monitored. Muscle fiber types and capillaries were identified by immunohistochemistry. Fiber oxidative capacity was determined as the optical density (OD) at 660 nm of succinate dehydrogenase (SDH)-stained sections. The product of fiber cross-sectional area and SDH-OD (integrated SDH) indicated the maximal oxygen consumption of that fiber. The maximal oxygen consumption supported by a capillary was calculated as the integrated SDH in its supply area. BR reduced isometric strength of knee extensor muscles (P capacity (P capacity in both muscles (P capacity is proportionally larger than the loss of capillaries. WP+KHCO3 appears to attenuate disuse-induced reductions in fiber oxidative capacity.

  5. Improvement in lipids extraction processes for biodiesel production from wet microalgal pellets grown on diammonium phosphate and sodium bicarbonate combinations.

    Science.gov (United States)

    Shah, Syed Hasnain; Raja, Iftikhar Ahmed; Mahmood, Qaisar; Pervez, Arshid

    2016-08-01

    Biomass productivity and growth kinetics for microalgae grown on sodium bicarbonate and diammonium phosphate were investigated. Different carbon and nitrogen ratios have shown different growth rates and biomass productivity and C:N ratio 50:10 as mgL(-1) has shown the best production than all. For effective lipids extraction from biomass thermolysis and sonolysis were carried out from wet biomass. Sonolysis at 2.3W intensity for 5min has released 8.58mg at neutral pH. More quantity of lipids was extracted when extraction was made at pH 4 and 10 which resulted 9mg and 9.28mg lipids respectively. Thermal treatment at 100°C for 10min has released 12.82mg lipid at neutral pH. In the same thermolysis at pH 4 and 10 more quantity of lipids was extracted which were 15.16mg and 14.81mg respectively. Finally transesterified lipids were analyzed through GC-MS for FAME composition analysis.

  6. Bicarbonate-sensing soluble adenylyl cyclase is present in the cell cytoplasm and nucleus of multiple shark tissues.

    Science.gov (United States)

    Roa, Jinae N; Tresguerres, Martin

    2017-01-01

    The enzyme soluble adenylyl cyclase (sAC) is directly stimulated by bicarbonate (HCO3(-)) to produce the signaling molecule cyclic adenosine monophosphate (cAMP). Because sAC and sAC-related enzymes are found throughout phyla from cyanobacteria to mammals and they regulate cell physiology in response to internal and external changes in pH, CO2, and HCO3(-), sAC is deemed an evolutionarily conserved acid-base sensor. Previously, sAC has been reported in dogfish shark and round ray gill cells, where they sense and counteract blood alkalosis by regulating the activity of V-type H(+)- ATPase. Here, we report the presence of sAC protein in gill, rectal gland, cornea, intestine, white muscle, and heart of leopard shark Triakis semifasciata Co-expression of sAC with transmembrane adenylyl cyclases supports the presence of cAMP signaling microdomains. Furthermore, immunohistochemistry on tissue sections, and western blots and cAMP-activity assays on nucleus-enriched fractions demonstrate the presence of sAC protein in and around nuclei. These results suggest that sAC modulates multiple physiological processes in shark cells, including nuclear functions.

  7. Measurement of Total Free Iron in Soils by H2S Chemisorption and Comparison with the Citrate Bicarbonate Dithionite Method

    Directory of Open Access Journals (Sweden)

    Shui-Sheng Fan

    2016-01-01

    Full Text Available Free iron is one of the major analytical items for soil basic properties. It is also an important indicator for understanding the genesis of soil, soil classification, and soil distribution behavior. In this study, an alternative analytical method (chemisorption based on thermodynamic knowledge was proposed for measurement of total free iron oxides in soils. Several representative soil samples belonging to alfisols, ultisols, inceptisols, and entisols were collected from Taiwan and tested by the chemisorption, and the estimated total free iron oxides were compared with those measured from the traditional citrate bicarbonate dithionite (CBD method. Experimental results showed that the optimal operating temperature was found to be at 773 K and the carbon monoxide (CO is the best gaseous reagent to promote the formation of FeS. The estimated total free iron oxides for soil samples determined from the chemisorption in the presence of CO were very close to those from the CBD technique. The result of regression indicates that the estimated total free iron is strongly correlated with the CBD-Fe content (R2=0.999 in the presence of CO.

  8. Evaluation of strength-enhancing factors of a ductile binder in direct compression of sodium bicarbonate and calcium carbonate powders.

    Science.gov (United States)

    Mattsson, S; Nyström, C

    2000-03-01

    This study evaluated the effectiveness of a ductile binder in direct compression of sodium bicarbonate and calcium carbonate powders. Properties associated with both the binder and the compound were studied. The addition of binder materials, such as polyethylene glycols (PEGs) of differing molecular weights or microcrystalline cellulose, generally resulted in an increase in the axial tensile strength of the corresponding compacts. The increase in tablet strength was generally greater with the PEGs than with microcrystalline cellulose. The results indicate that the improvement in tablet strength caused by the binder is dependent on properties of both the binder and the compound. By utilising different methods it was established that the fracture during tablet strength testing mainly occurred around the compound particles. As a consequence of this, it appears that the ability of the binder to fill the voids between the compound particles is a determinative factor for increasing tablet strength. The binder appeared to have less effect when added to compounds that fragmented during compaction. Characteristics of the binder resulting in the greatest decrease in porosity, and thus the greatest increase in the tensile strength of the compound, included a high degree of plastic deformation with a limited elastic component and a small particle size. Obviously, the amount of binder added to the mixture also affected the results.

  9. [Effect of treatments of hydrogen peroxide and sodium dithionite-citrate-bicarbonate on clay minerals of red earth sediments].

    Science.gov (United States)

    Li, Rong-Biao; Hong, Han-Lie; Yin, Ke; Wang, Chao-Wen; Gao, Wen-Peng; Han, Wen; Wu, Qing-Feng

    2013-04-01

    As classical procedures for pretreatment of soil sediments, hydrogen peroxide (H2O2) and sodium dithionite-citrate-bicarbonate (DCB) treatment methods are very important in removing the organic matter and iron oxides acting as cementing agents in the soils. However, both of these methods have less been focused on the effect on the clay minerals when separating. Here, we report the comparable methods between H2O2 and DCB to reveal their effect on clay minerals in red earth sediments using X-ray diffraction (XRD). The XRD results suggested that mineral particles can be totally decentralized by either H2O2 or DCB method in the soils and high purity clay minerals can be obtained by separating quartz and other impurities from clay minerals effectively. However, the XRD data were distorted by the DCB treatment owning to the cation exchange between Na+ and interlayer cation. On the contrary, the authentic data can be obtained by H2O2 treatment. Therefore, the H2O2 treatment seems to be a more appropriate method to obtain authentic information of clay mineralogy when separating of clay minerals from red earth sediments.

  10. Measurement of Total Free Iron in Soils by H2S Chemisorption and Comparison with the Citrate Bicarbonate Dithionite Method

    Science.gov (United States)

    Fan, Shui-Sheng; Chang, Feng-Hsiang

    2016-01-01

    Free iron is one of the major analytical items for soil basic properties. It is also an important indicator for understanding the genesis of soil, soil classification, and soil distribution behavior. In this study, an alternative analytical method (chemisorption) based on thermodynamic knowledge was proposed for measurement of total free iron oxides in soils. Several representative soil samples belonging to alfisols, ultisols, inceptisols, and entisols were collected from Taiwan and tested by the chemisorption, and the estimated total free iron oxides were compared with those measured from the traditional citrate bicarbonate dithionite (CBD) method. Experimental results showed that the optimal operating temperature was found to be at 773 K and the carbon monoxide (CO) is the best gaseous reagent to promote the formation of FeS. The estimated total free iron oxides for soil samples determined from the chemisorption in the presence of CO were very close to those from the CBD technique. The result of regression indicates that the estimated total free iron is strongly correlated with the CBD-Fe content (R2 = 0.999) in the presence of CO. PMID:28116218

  11. The effect of feeding on CO2 production and energy expenditure in ponies measured by indirect calorimetry and the 13C-bicarbonate technique

    DEFF Research Database (Denmark)

    Jensen, Rasmus Bovbjerg; Kyrstein, T. D.; Junghans, P

    2015-01-01

    and EE in the field. In this study, four Shetland ponies were used to explore the effect of feeding on CO(2) production and EE measured simultaneously by IC and (13)C-BT. The ponies were individually housed in respiration chambers and received either a single oral or intravenous (IV) bolus dose of (13)C......-labelled sodium bicarbonate (NaH(13)CO(3)). The ponies were fed haylage 3 h before (T(-3)), simultaneously with (T(0)) or 3 h after (T(+3)) administration of (13)C-bicarbonate. The CO(2) produced and O(2) consumed by the ponies were measured for 6 h with both administration routes of (13)C...

  12. Mediating Business

    DEFF Research Database (Denmark)

    "Mediating Business" is a study of the expansion of business journalism. Building on evidence from Denmark, Finland, Norway and Sweden, "Mediating Business" is a comparative and multidisciplinary study of one of the major transformations of the mass media and the realm of business - nationally...... and globally. The book explores the history of key innovations and innovators in the business press. It analyzes changes in the discourse of business journalism associated with the growth in business news and the development of new ways of framing business issues and events. Finally, it examines...... the organizational implications of the increased media visibility of business and, in particular, the development of corporate governance and media relations....

  13. Mediatized play

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    Children’s play must nowadays be understood as a mediatized field in society and culture. Media – understood in a very broad sense - holds severe explanatory power in describing and understanding the practice of play, since play happens both with, through and inspired by media of different sorts....... In this presentation the case of ‘playing soccer’ will be outlined through its different mediated manifestations, including soccer games and programs on TV, computer games, magazines, books, YouTube videos and soccer trading cards....

  14. Effects of an Ionophore Coccidiostat (Monensin or Salinomycin, Sodium or Potassium Bicarbonate, or Both, and Bacitracin Methylene Disalicylate in Broiler Chicken Diets

    Directory of Open Access Journals (Sweden)

    Hooge DM

    2000-01-01

    Full Text Available Peterson x Arbor Acres chicks were grown on used litter to 45 or 46 days of age in three pen trials. Coccidial inoculations were given by water at 14 days of age. Sodium bicarbonate (SBC; 0.20% or potassium bicarbonate (PBC; 0.14% was added to broiler chicken diets containing monensin (MON; 110 mg/kg or salinomycin (SAL; 66 mg/kg in Experiment 1. In Experiment 2, using SAL (55 mg/kg, three dietary bicarbonate treatments (SBC, 0.20%; PBC, 0.20%; or SBC + PBC 0.10% each were tested with or without BMD R (55 mg/kg. Diets differing in SAL, BMD R, and SBC levels were evaluated in Experiment 3. Beneficial interaction was found between ionophores and bicarbonates for mortality (lower when SBC or PBC and MON in Experiment 1. For main effects, in Experiment 1 PBC with MON or SAL improved body weight, feed conversion ratio and mortality. SAL improved weight, feed conversion ratio and mortality compared to MON. In Experiment 2, PBC with SAL improved weight, coccidial lesion score, feed conversion ratio and mortality across two levels of BMD R. The PBC and SBC were equally effective in Experiment 1, but PBC was about 0 to 40% as effective as SBC, depending on parameter in Experiment 2. Half levels of SBC plus PBC generally gave intermediate results between control and SBC. SBC with MON or SAL lowered mortalities, coccidial lesion scores, and feed conversion ratios (Experiments 1 and 2, and increased body weight (Experiment 2. In Experiment 3, BMD R in all feeds improved body weight and feed conversion versus in starter feed only, and SBC with SAL and BMD R improved all performance parameters.

  15. Intravenous Lipid Emulsion Therapy Does Not Improve Hypotension Compared to Sodium Bicarbonate for Tricyclic Antidepressant Toxicity: A Randomized, Controlled Pilot Study in a Swine Model

    Science.gov (United States)

    2014-11-01

    amitriptyline-induced hypotension. The objective was to determine if ILE improved hypotension (defined by a mean arterial pressure [MAP] < 60% baseline...more effective in improving hypotension (defined by a mean arterial pressure [MAP] < 60% baseline) compared to sodium bicarbon- ate for treatment of...amitriptyline overdose in a critically ill swine model. METHODS Study Design Using a porcine model of amitriptyline-induced hypo- tension , we used a

  16. Water Mediated Wittig Reactions of Aldehydes in the Teaching Laboratory: Using Sodium Bicarbonate for the in Situ Formation of Stabilized Ylides

    Science.gov (United States)

    Kelly, Michael J. B.; Fallot, Lucas B.; Gustafson, Jeffrey L.; Bergdahl, B. Mikael

    2016-01-01

    The synthesis of alkenes using the Wittig reaction is a traditional part of many undergraduate organic chemistry teaching laboratory curricula. The aqueous medium version of the Wittig reaction presented is a reliable adaptation of this alkene formation reaction as a very safe alternative in the introductory organic chemistry laboratory. The…

  17. Simultaneous measurement of pH and membrane potential in rat dorsal vagal motoneurons during normoxia and hypoxia: a comparison in bicarbonate and HEPES buffers.

    Science.gov (United States)

    Cowan, A I; Martin, R L

    1995-12-01

    1. The effects of oxygenated and hypoxic bicarbonate/CO2, 10 and 25 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES)-buffered artificial cerebrospinal fluid (ACSF) have been studied in a rat brain slice preparation. Double-barreled pH-selective microelectrodes were used to measure intracellular pH (pHi) and membrane potential in dorsal vagal motoneurons (DVMs) and to measure extracellular pH (pHe) in the dorsal vagal motonucleus. 2. In bicarbonate ACSF, pHi averaged 7.24 +/- 0.05 (mean +/- SE, n = 21) and ranged from 6.86 to 7.79 pH units. pHe averaged 7.13 +/- 0.08 (n = 10). 3. On changing from oxygenated bicarbonate ACSF to either 10 or 25 mM HEPES ACSF, pHi decreased by 0.13-0.15 units, and the membrane depolarized by 10-11 mV. pHe also decreased in 10 mM HEPES ACSF (pHe 6.89 +/- 0.02, n = 8) but not in 25 mM HEPES ACSF (pHe 7.15 +/- 0.06, n = 3). In most neurons changes in pHi preceded changes in membrane potential. 4. In bicarbonate ACSF and in 25 mM HEPES ACSF, there was a significant linear relationship between prehypoxic pHi and the direction and amplitude of the hypoxia-induced membrane potential change (either an hyperpolarization or a depolarization). 5. In 10 mM HEPES ACSF, hypoxia always induced a depolarization; there was no correlation between prehypoxic pHi and the membrane potential response. 6. In bicarbonate ACSF and in 10 and 25 mM HEPES ACSF, hypoxia resulted in intracellular and extracellular acidification. However, the extracellular acidification in hypoxic 10 mM HEPES buffer was most pronounced (pH 6.40 +/- 0.11, n = 8), reflecting a preexisting extracellular acidification in oxygenated 10 mM HEPES buffer. 7. Various hypotheses that could give rise to a relationship between changes in membrane potential and pH are discussed; arguments are presented in favor of the concept that modulation of ion channels by either pHi or pHe, or both, is responsible for the observed correlations.

  18. How Strong Is the Evidence for Sodium Bicarbonate to Prevent Contrast-Induced Acute Kidney Injury After Coronary Angiography and Percutaneous Coronary Intervention?

    Science.gov (United States)

    Dong, Yuhao; Zhang, Bin; Liang, Long; Lian, Zhouyang; Liu, Jing; Liang, Changhong; Zhang, Shuixing

    2016-01-01

    Abstract Hydration with sodium bicarbonate is one of the strategies to prevent contrast-induced acute kidney injury (CI-AKI). The purpose of this study was to determine how strong is the evidence for sodium bicarbonate to prevent CI-AKI after coronary angiography (CAG) and/or percutaneous coronary intervention (PCI). We conducted PubMed, EMBASE, and CENTRAL databases to search for randomized controlled trials (RCTs) comparing the efficacy of sodium bicarbonate with sodium chloride to prevent CI-AKI after CAG and/or PCI. Relative risk (RR), standardized mean difference (SMD), or weighted mean difference (WMD) with 95% confidence intervals (CIs) was calculated. Heterogeneity, publication bias, and study quality were evaluated, sensitivity analyses, cumulative analyses, and subgroup analyses were performed. The risk of random errors was assessed by trial sequential analysis (TSA). Sixteen RCTs (3537 patients) met the eligibility criteria. Hydration with sodium bicarbonate showed significant beneficial effects in preventing CI-AKI (RR 0.67; 95% CI: 0.47–0.96, P = 0.029), decreasing the change in serum creatinine (SCr) (SMD −0.31 95% CI: −0.55 to −0.07, P = 0.011) and estimated glomerular filtration rate (eGFR) (SMD −0.17 95% CI: −0.30 to −0.04, P = 0.013). But no significant differences were observed in the requirement for dialysis (RR 1.11; 95% CI: 0.60–2.07, P = 0.729), mortality (RR 0.71; 95% CI: 0.41–1.21, P = 0.204) and reducing the length of hospital stay (LHS) (WMD −1.47; 95% CI: −4.14 to 1.20, P = 0.279). The result of TSA on incidence of CI-AKI showed the required information size (RIS = 6614) was not reached and cumulative z curve did not cross TSA boundary. The result of TSA on the requirement for dialysis and mortality demonstrated the required information sizes (RIS = 170,510 and 19,516, respectively) were not reached, and the cumulative z-curve did not cross any boundaries. The evidence that sodium

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

    Directory of Open Access Journals (Sweden)

    Delgado Anca G

    2012-09-01

    Full Text Available Abstract 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

  20. Effectiveness of sodium bicarbonate combined with hydrogen peroxide and CPP-ACPF in whitening and microhardness of enamel

    Science.gov (United States)

    Hasanzadeh, Nadia; Rajabi, Omid; Forouzannejad, Zakiyeh

    2017-01-01

    Background This study investigated the effects of sodium bicarbonate (NaHCO3) combined with 1.5% hydrogen peroxide (H2O2) and casein phosphopeptide amorphous calcium phosphate fluoride (CPP-ACPF) on color and microhardness of enamel. Material and Methods Seventy-five bovine incisors were immersed in a tea solution for 7.5 days. The specimens were randomly divided into five groups according to the whitening agent applied: 1) 94% NaHCO3, 2) a blend of 94% NaHCO3 and CPP-ACPF, 3) a blend of 94% NaHCO3 and 1.5% H2O2, 4) a blend of 94% NaHCO3, 1.5% H2O2 and CPP-ACPF, 5) control. The whitening procedure was performed for 10 times over 10 days. At each day, the buccal surfaces were covered with whitening agents for 5 minutes and then brushed for 30 seconds. After the 10 days, the teeth were again immersed in a tea solution for 10 minutes. Color assessment was performed at baseline (T1), after the first staining process (T2), after the whitening procedure (T3), and after the second staining process (T4). Finally, the specimens were subjected to microhardness test. Results There was a statistically significant difference in the color change between T2 and T3 stages among the study groups (p<0.05), with the greatest improvement observed in group 4. Microhardness was significantly greater in groups 2 and 4, as compared to the other groups (p<0.05). Conclusions The combination of 94% NaHCO3, 1.5% H2O2 and CPP-ACPF was effective in improving color and microhardness of teeth with extrinsic stains and could be recommended in the clinical situation.

  1. Effect of 10% sodium bicarbonate on bond strength of enamel and dentin after bleaching with 38% hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Fernanda Medeiros Darzé

    Full Text Available AbstractIntroductionBy-products of hydrogen peroxide degradation released during dental bleaching influence the polymerization of adhesive systems and composite resins, causing a reduction in shear bond strength to the tooth.Objectivethe aim of this article was to evaluate the effect of 10% sodium bicarbonate (SB, applied for different lengths of time, on the shear bond strength to enamel and dentin after bleaching.Material and methodEnamel and dentin blocks were divided into groups (n=10: (1 control: no bleaching; (2 immediate: bleaching immediately followed by restoration; (3 14-day: bleaching, restoration 14 days later; (4 SB for 10 minutes: bleaching, SB gel for 10 minutes, immediately followed by restoration; (5 SB for 20 minutes: bleaching, SB gel for 20 minutes, immediately followed by restoration. A 38% hydrogen peroxide gel (Opalescence Boost/Ultradent was used. After application of the adhesive system, composite resin cylinders were mounted on the surface of the substrates in order to test shear bond strength. Result: ANOVA and Tukey tests showed significantly higher mean enamel bond strength values for the 14-day follow-up group and without significant differences for control group. Mean bond strength values obtained for the other groups were intermediate. When testing dentin, the Tukey test revealed a significantly higher mean bond strength value for the 14-day follow-up group when compared with application of SB for 20 minutes.ConclusionSB gel applied was unable to reverse the low bond strength to enamel and dentin after bleaching treatment.

  2. Structural modifications of the salivary conditioning film upon exposure to sodium bicarbonate: implications for oral lubrication and mouthfeel.

    Science.gov (United States)

    Ash, A; Wilde, P J; Bradshaw, D J; King, S P; Pratten, J R

    2016-03-14

    The salivary conditioning film (SCF) that forms on all surfaces in the mouth plays a key role in lubricating the oral cavity. As this film acts as an interface between tongue, enamel and oral mucosa, it is likely that any perturbations to its structure could potentially lead to a change in mouthfeel perception. This is often experienced after exposure to oral hygiene products. For example, consumers that use dentifrice that contain a high concentration of sodium bicarbonate (SB) often report a clean mouth feel after use; an attribute that is clearly desirable for oral hygiene products. However, the mechanisms by which SB interacts with the SCF to alter lubrication in the mouth is unknown. Therefore, saliva and the SCF was exposed to high ionic strength and alkaline solutions to elucidate whether the interactions observed were a direct result of SB, its high alkalinity or its ionic strength. Characteristics including bulk viscosity of saliva and the viscoelasticity of the interfacial salivary films that form at both the air/saliva and hydroxyapatite/saliva interfaces were tested. It was hypothesised that SB interacts with the SCF in two ways. Firstly, the ionic strength of SB shields electrostatic charges of salivary proteins, thus preventing protein crosslinking within the film and secondly; the alkaline pH (≈8.3) of SB reduces the gel-like structure of mucins present in the pellicle by disrupting disulphide bridging of the mucins via the ionization of their cysteine's thiol group, which has an isoelectric point of ≈8.3.

  3. The ergogenic effect of beta-alanine combined with sodium bicarbonate on high-intensity swimming performance.

    Science.gov (United States)

    Painelli, Vitor de Salles; Roschel, Hamilton; Jesus, Flávia de; Sale, Craig; Harris, Roger Charles; Solis, Marina Yázigi; Benatti, Fabiana Braga; Gualano, Bruno; Lancha, Antonio Herbert; Artioli, Guilherme Giannini

    2013-05-01

    We investigated the effect of beta-alanine (BA) alone (study A) and in combination with sodium bicarbonate (SB) (study B) on 100- and 200-m swimming performance. In study A, 16 swimmers were assigned to receive either BA (3.2 g·day(-1) for 1 week and 6.4 g·day(-1) for 4 weeks) or placebo (PL; dextrose). At baseline and after 5 weeks of supplementation, 100- and 200-m races were completed. In study B, 14 were assigned to receive either BA (3.2 g·day(-1) for 1 week and 6.4 g·day(-1) for 3 weeks) or PL. Time trials were performed once before and twice after supplementation (with PL and SB), in a crossover fashion, providing 4 conditions: PL-PL, PL-SB, BA-PL, and BA-SB. In study A, BA supplementation improved 100- and 200-m time-trial performance by 2.1% (p = 0.029) and 2.0% (p = 0.0008), respectively. In study B, 200-m time-trial performance improved in all conditions, compared with presupplementation, except the PL-PL condition (PL-SB, +2.3%; BA-PL, +1.5%; BA-SB, +2.13% (p supplementation. The probability of BA having a positive effect was 65.2%; when SB was added to BA, the probability was 71.8%. BA and SB supplementation improved 100- and 200-m swimming performance. The coingestion of BA and SB induced a further nonsignificant improvement in performance.

  4. The potential effects of sodium bicarbonate, a major constituent from coalbed natural gas production, on aquatic life

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2012-01-01

    The production water from coalbed natural gas (CBNG) extraction contains many constituents. The U.S. Environmental Protection Agency has established aquatic life criteria for some of these constituents, and it is therefore possible to evaluate their risk to aquatic life. However, of the major ions associated with produced waters, chloride is the only one with an established aquatic life criterion (U.S. Environmental Protection Agency, 1988). The focus of this research was NaHCO3, a compound that is a major constituent of coalbed natural gas produced waters in the Tongue and Powder River Basins. This project included laboratory experiments, field in situ experiments, a field mixing zone study, and a fishery presence/absence assessment. Though this investigation focuses on the Tongue and Powder River Basins, the information is applicable to other watersheds where sodium bicarbonate is a principle component of product water either from CBNG or from traditional or unconventional oil and gas development. These data can also be used to separate effects of saline discharges from those potentially posed by other constituents. Finally, this research effort and the additional collaboration with USGS Water Resources and Mapping, Bureau of Land Management, US Environmental Protection Agency, State of Montana, State of Wyoming, Montana State University, University of Wyoming, and others as part of a Powder River Aquatic Task Group, can be used as a model for successful approaches to studying landscapes with energy development. The laboratory acute toxicity experiments were completed with a suite of organisms, including 7 species of fish, 5 species of invertebrates, and 1 amphibian species. Experiments performed on these multiple species resulted in LC50s that ranged from 1,120 to greater than (>) 8,000 milligrams sodium bicarbonate per liter (mg NaHCO3/L) (also defined as 769 to >8,000 milligrams bicarbonate per liter (mg HCO3-/L) or total alkalinity expressed as 608 to >4

  5. The potential effects of sodium bicarbonate, a major constituent from coalbed natural gas production, on aquatic life

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2012-01-01

    The production water from coalbed natural gas (CBNG) extraction contains many constituents. The U.S. Environmental Protection Agency has established aquatic life criteria for some of these constituents, and it is therefore possible to evaluate their risk to aquatic life. However, of the major ions associated with produced waters, chloride is the only one with an established aquatic life criterion (U.S. Environmental Protection Agency, 1988). The focus of this research was NaHCO3, a compound that is a major constituent of coalbed natural gas produced waters in the Tongue and Powder River Basins. This project included laboratory experiments, field in situ experiments, a field mixing zone study, and a fishery presence/absence assessment. Though this investigation focuses on the Tongue and Powder River Basins, the information is applicable to other watersheds where sodium bicarbonate is a principle component of product water either from CBNG or from traditional or unconventional oil and gas development. These data can also be used to separate effects of saline discharges from those potentially posed by other constituents. Finally, this research effort and the additional collaboration with USGS Water Resources and Mapping, Bureau of Land Management, US Environmental Protection Agency, State of Montana, State of Wyoming, Montana State University, University of Wyoming, and others as part of a Powder River Aquatic Task Group, can be used as a model for successful approaches to studying landscapes with energy development. The laboratory acute toxicity experiments were completed with a suite of organisms, including 7 species of fish, 5 species of invertebrates, and 1 amphibian species. Experiments performed on these multiple species resulted in LC50s that ranged from 1,120 to greater than (>) 8,000 milligrams sodium bicarbonate per liter (mg NaHCO3/L) (also defined as 769 to >8,000 milligrams bicarbonate per liter (mg HCO3-/L) or total alkalinity expressed as 608 to >4

  6. The impact of seawater saturation state and bicarbonate ion concentration on calcification by new recruits of two Atlantic corals

    Science.gov (United States)

    de Putron, S. J.; McCorkle, D. C.; Cohen, A. L.; Dillon, A. B.

    2011-06-01

    Rising concentrations of atmospheric CO2 are changing the carbonate chemistry of the oceans, a process known as ocean acidification (OA). Absorption of this CO2 by the surface oceans is increasing the amount of total dissolved inorganic carbon (DIC) and bicarbonate ion (HCO3 -) available for marine calcification yet is simultaneously lowering the seawater pH and carbonate ion concentration ([CO3 2-]), and thus the saturation state of seawater with respect to aragonite (Ωar). We investigated the relative importance of [HCO3 -] versus [CO3 2-] for early calcification by new recruits (primary polyps settled from zooxanthellate larvae) of two tropical coral species, Favia fragum and Porites astreoides. The polyps were reared over a range of Ωar values, which were manipulated by both acid-addition at constant pCO2 (decreased total [HCO3 -] and [CO3 2-]) and by pCO2 elevation at constant alkalinity (increased [HCO3 -], decreased [CO3 2-]). Calcification after 2 weeks was quantified by weighing the complete skeleton (corallite) accreted by each polyp over the course of the experiment. Both species exhibited the same negative response to decreasing [CO3 2-] whether Ωar was lowered by acid-addition or by pCO2 elevation—calcification did not follow total DIC or [HCO3 -]. Nevertheless, the calcification response to decreasing [CO3 2-] was nonlinear. A statistically significant decrease in calcification was only detected between Ωar = <2.5 and Ωar = 1.1-1.5, where calcification of new recruits was reduced by 22-37% per 1.0 decrease in Ωar. Our results differ from many previous studies that report a linear coral calcification response to OA, and from those showing that calcification increases with increasing [HCO3 -]. Clearly, the coral calcification response to OA is variable and complex. A deeper understanding of the biomineralization mechanisms and environmental conditions underlying these variable responses is needed to support informed predictions about future OA

  7. Comparative transcriptional profiling of Bacillus cereus sensu lato strains during growth in CO2-bicarbonate and aerobic atmospheres.

    Directory of Open Access Journals (Sweden)

    Karla D Passalacqua

    Full Text Available BACKGROUND: Bacillus species are spore-forming bacteria that are ubiquitous in the environment and display a range of virulent and avirulent phenotypes. This range is particularly evident in the Bacillus cereus sensu lato group; where closely related strains cause anthrax, food-borne illnesses, and pneumonia, but can also be non-pathogenic. Although much of this phenotypic range can be attributed to the presence or absence of a few key virulence factors, there are other virulence-associated loci that are conserved throughout the B. cereus group, and we hypothesized that these genes may be regulated differently in pathogenic and non-pathogenic strains. METHODOLOGY/PRINCIPAL FINDINGS: Here we report transcriptional profiles of three closely related but phenotypically unique members of the Bacillus cereus group--a pneumonia-causing B. cereus strain (G9241, an attenuated strain of B. anthracis (Sterne 34F(2, and an avirulent B. cereus strain (10987--during exponential growth in two distinct atmospheric environments: 14% CO(2/bicarbonate and ambient air. We show that the disease-causing Bacillus strains undergo more distinctive transcriptional changes between the two environments, and that the expression of plasmid-encoded virulence genes was increased exclusively in the CO(2 environment. We observed a core of conserved metabolic genes that were differentially expressed in all three strains in both conditions. Additionally, the expression profiles of putative virulence genes in G9241 suggest that this strain, unlike Bacillus anthracis, may regulate gene expression with both PlcR and AtxA transcriptional regulators, each acting in a different environment. CONCLUSIONS/SIGNIFICANCE: We have shown that homologous and even identical genes within the genomes of three closely related members of the B. cereus sensu lato group are in some instances regulated very differently, and that these differences can have important implications for virulence. This study

  8. A synergistic effect in controlling plum postharvest diseases occurs by applying UV-C light to sodium bicarbonate treated fruit.

    Science.gov (United States)

    D'Hallewin, G; Cubaiu, L; Ladu, G; Venditti, T

    2013-01-01

    The effectiveness of ultraviolet-C light (UV-C; 254 nm) alone at 0, 3, 6 and 12 kJm(-2), or combined with 0.0 or 0.5% (w7v) sodium bicarbonate (SBC), to control plum (Prunus domestica cv Stanley) postharvest decay caused by Penicillium expansum L. and Botrytis cinerea was investigated. First, fruit was sanitized and in one experiment plums were artificially wound-inoculated 24 h before treatments and afterwards kept at 25 degrees C with 90% RH for 7 days. In the second experiment, treatments were applied before fruit was spray-contaminated with conidia and then stored for 4 weeks at 5 degrees C and 90% RH (storage conditions). In both experiments, the highest degree of decay caused by the two pathogens was monitored when fruit stayed untreated (control), and a negligible reduction was achieved by treating with the sole salt or with a 3 kJm(-2) UV-C light. Compared to control (89 +/- 3% decay), the treatment of wound-inoculated fruit with 6 kJm(-2) provided a 35 and 38% reduction of P. expansum and B. cinerea decay, respectively. Meanwhile, 12 kJm(-2) provided an additional decrease of 25 and 27%, respectively. In both experiments, the best control of decay was attained when treatments with SBC and UV-C light were combined and the efficacy depended upon the sequence of application. Synergistic effects were found by applying the salt before UV-C light. When 6 or 12 kJm(-2) were employed following the 2% SBC treatment, no disease symptoms developed for either pathogens in both experiments. The same combination with 3 kJm(-2) resulted in a nearly 5 fold increase of efficacy compared to the sole light treatment. The combined treatments controlled the two pathogens to valuable levels and, since no quality losses were observed during storage, they could be considered as a suitable approach to contain postharvest losses of this fruit.

  9. Infusing sodium bicarbonate suppresses hydrogen peroxide accumulation and superoxide dismutase activity in hypoxic-reoxygenated newborn piglets.

    Directory of Open Access Journals (Sweden)

    Jiang-Qin Liu

    Full Text Available BACKGROUND: The effectiveness of sodium bicarbonate (SB has recently been questioned although it is often used to correct metabolic acidosis of neonates. The aim of the present study was to examine its effect on hemodynamic changes and hydrogen peroxide (H(2O(2 generation in the resuscitation of hypoxic newborn animals with severe acidosis. METHODS: Newborn piglets were block-randomized into a sham-operated control group without hypoxia (n = 6 and two hypoxia-reoxygenation groups (2 h normocapnic alveolar hypoxia followed by 4 h room-air reoxygenation, n = 8/group. At 10 min after reoxygenation, piglets were given either i.v. SB (2 mEq/kg, or saline (hypoxia-reoxygenation controls in a blinded, randomized fashion. Hemodynamic data and blood gas were collected at specific time points and cerebral cortical H(2O(2 production was continuously monitored throughout experimental period. Plasma superoxide dismutase and catalase and brain tissue glutathione, superoxide dismutase, catalase, nitrotyrosine and lactate levels were assayed. RESULTS: Two hours of normocapnic alveolar hypoxia caused cardiogenic shock with metabolic acidosis (PH: 6.99 ± 0.07, HCO(3(-: 8.5 ± 1.6 mmol/L. Upon resuscitation, systemic hemodynamics immediately recovered and then gradually deteriorated with normalization of acid-base imbalance over 4 h of reoxygenation. SB administration significantly enhanced the recovery of both pH and HCO(3- recovery within the first hour of reoxygenation but did not cause any significant effect in the acid-base at 4 h of reoxygenation and the temporal hemodynamic changes. SB administration significantly suppressed the increase in H(2O(2 accumulation in the brain with inhibition of superoxide dismutase, but not catalase, activity during hypoxia-reoxygenation as compared to those of saline-treated controls. CONCLUSIONS: Despite enhancing the normalization of acid-base imbalance, SB administration during resuscitation did not provide any beneficial

  10. 碳酸氢铵为氮源对螺旋藻培养的影响%Effect of Ammonium Bicarbonate as Nitrogen Source on Spirulina platensis Cultivation

    Institute of Scientific and Technical Information of China (English)

    鲍亦璐; 刘明; 丛威; 卢运明; 宁正祥

    2012-01-01

    以碳酸氢铵作为氮源,研究在分批培养及流加培养条件下其对螺旋藻生长的影响。结果表明:当培养液中碳酸氢铵浓度小于5mmol/L时,螺旋藻生长正常;碳酸氢铵浓度超过5mmol/L时,螺旋藻生长受到抑制,解体死亡。采用生物量反馈补料的流加策略可以使培养液中螺旋藻生物量达到3.08g/L,产率达到0.26g/(L.d),藻体中蛋白质及叶绿素含量分别达到65.06%和13.37mg/g,结果证实了碳酸氢铵为氮源高密度培养螺旋藻的可行性。%The batch and fed-batch cultivations of Spirulina platensis were studied using ammonium bicarbonate as the nitrogen source. The results showed that Spirulinaplatensis could grow well when ammonium concentration in the medium was less than 5 mmol/L. However, when the concentration of ammonium bicarbonate was higher than 5 retool/L, cell growth was inhibited and disintegrated. The fed-batch cultivation using biomass-based feeding method could yield a dry cell concentration of 3.08 g/L, and a productivity of 0.26 g/(L· d). Moreover, the contents of protein and chlorophyll could reach up to 65.06% and 13.37 mg/g, respectively. Therefore, bicarbonate ammonium is a suitable nitrogen source for high cell density culture of Spirulina platensis.

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

    Science.gov (United States)

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

    2014-07-01

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

  12. Density functional theory studies on theelectronic, structural, phonon dynamicaland thermo-stability properties of bicarbonates MHCO3, M D Li, Na, K

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Yuhua; Zhang, Bo; Sorescu, Dan C.; Johnson, Karl; Majzoub, Eric H; Luebke, David R.

    2012-07-01

    The structural, electronic, phonon dispersion and thermodynamic properties of MHCO3 (M D Li, Na, K) solids were investigated using density functional theory. The calculated bulk properties for both their ambient and the high-pressure phases are in good agreement with available experimental measurements. Solid phase LiHCO3 has not yet been observed experimentally. We have predicted several possible crystal structures for LiHCO3 using crystallographic database searching and prototype electrostatic ground state modeling. Our total energy and phonon free energy .FPH/ calculations predict that LiHCO3 will be stable under suitable conditions of temperature and partial pressures of CO2 and H2O. Our calculations indicate that the HCO 3 groups in LiHCO3 and NaHCO3 form an infinite chain structure through O H O hydrogen bonds. In contrast, the HCO 3 anions form dimers, .HCO 3 /2, connected through double hydrogen bonds in all phases of KHCO3. Based on density functional perturbation theory, the Born effective charge tensor of each atom type was obtained for all phases of the bicarbonates. Their phonon dispersions with the longitudinal optical–transverse optical splitting were also investigated. Based on lattice phonon dynamics study, the infrared spectra and the thermodynamic properties of these bicarbonates were obtained. Over the temperature range 0–900 K, the FPH and the entropies (S) of MHCO3 (M D Li, Na, K) systems vary as FPH.LiHCO3/ > FPH.NaHCO3/ > FPH.KHCO3/ and S.KHCO3/ > S.NaHCO3/ > S.LiHCO3/, respectively, in agreement with the available experimental data. Analysis of the predicted thermodynamics of the CO2 capture reactions indicates that the carbonate/bicarbonate transition reactions for Na and K could be used for CO2 capture technology, in agreement with experiments.

  13. Acute toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters, to 13 aquatic species as defined in the laboratory

    Science.gov (United States)

    Harper, David D.; Farag, Aida M.; Skaar, Don

    2014-01-01

    Water produced during coal bed natural gas (CBNG) extraction in the Powder River Structural Basin of Wyoming and Montana (USA) may contain concentrations of sodium bicarbonate (NaHCO3) of more than 3000 mg/L. The authors evaluated the acute toxicity of NaHCO3, also expressed as bicarbonate (HCO3−), to 13 aquatic organisms. Of the 13 species tested, 7 had a median lethal concentration (LC50) less than 2000 mg/L NaHCO3, or 1300 mg/L HCO3−. The most sensitive species were Ceriodaphnia dubia, freshwater mussels (Lampsilis siliquoidea), pallid sturgeon (Scaphirhynchus albus), and shovelnose sturgeon (Scaphirhynchus platorynchus). The respective LC50s were 989 mg/L, 1120 mg/L, 1249 mg/L, and 1430 mg/L NaHCO3, or 699 mg/L, 844 mg/L, 831 mg/L, and 1038 mg/L HCO3−. Age affected the sensitivity of fathead minnows, even within life stage. Two days posthatch, fathead minnows were more sensitive to NaHCO3 and HCO3− compared with 4-d-old fish, even though fish up to 14 d old are commonly used for toxicity evaluations. The authors recommend that ion toxicity exposures be conducted with organisms less than 24 h posthatch to ensure that experiments document the most sensitive stage of development. The results of the present study, along with historical and current research regarding the toxicity of bicarbonate, may be useful to establish regulatory standards for HCO3−.

  14. Use of potassium bicarbonate (Armicarb) on the control of powdery mildew (Sphaerotheca mors-uvae) of gooseberry (Ribes uva-crispa).

    Science.gov (United States)

    Wenneker, M; Kanne, J

    2010-01-01

    Powdery mildew (Sphaerotheca mors-uvae) severely infects young shoots, stems and fruits of gooseberry (Ribes uva-crispa). Environmental friendly and biological control measures are being sought throughout the world. Especially in organic gooseberry growing effective control measures are needed, because powdery mildew infections may result in a total loss of the crop. In organic currant growing the number of adequate control methods is very limited. Sulphur as a fungicide against powdery mildew in e.g. gooseberry or table grape growing is not recommendable due to possible bleaching of berries and scorching of tender shoots. Various bicarbonate salts are suggested as a good option to control powdery mildew. In a field trial the effect of potassium bicarbonate (Armicarb) on the on the control of powdery mildew of gooseberry was evaluated. Four treatments; i.e. two preventive strategies and two curative strategies, were applied. PLants were sprayed until runoff. The percent of infected fruits and disease severity were assessed. In the unsprayed control plots very high disease incidences were observed; on average more than 90% of the berries were infected with powdery mildew. The weekly (preventive) spray applications with potassium carbonate reduced the disease incidences on fruits significantly. On average approximately 10% of the fruits were affected by powdery mildew. However, the number of spray applications was high. In conclusion, our results indicate that applications of potassium bicarbonate (as Armicarb) are effective in reducing the incidence and severity of American powdery mildew in gooseberry. Early spray applications are necessary to protect berries against powdery mildew infections. Future research will focus on reducing the number of applications, e.g. warning models based on powdery mildew of rose (Sphaerotheca pannosa).

  15. A randomized, crossover pharmacodynamic study of immediate‐release omeprazole/sodium bicarbonate and delayed‐release lansoprazole in healthy adult volunteers

    OpenAIRE

    Pratha, Vijayalakshmi S.; McGraw, Thomas; Tobin, William

    2016-01-01

    Abstract Proton pump inhibitors (PPIs) effectively block gastric acid secretion and are the treatment of choice for heartburn. PPIs differ, however, in onset of action and bioavailability. In this single‐center, open‐label, three‐way crossover study, onset of action of immediate‐release omeprazole 20 mg/sodium bicarbonate 1100 mg (IR‐OME) and delayed‐release (DR) lansoprazole 15 mg was evaluated in 63 healthy fasting adults. Subjects were randomized to once daily IR‐OME, or DR‐lansoprazole, o...

  16. Effect of sodium bicarbonate and varying concentrations of sodium chloride in brine on the liquid retention of fish (Pollachius virensL.) muscle

    DEFF Research Database (Denmark)

    Åsli, Magnus; Ofstad, Ragni; Böcker, Ulrike

    2016-01-01

    BACKGROUND Negative health effects associated with excessive sodium (Na) intake have increased the demand for tasty low-Na products (<2% NaCl) rather than traditional heavily salted fish products (∼20% NaCl). This study investigates the causes of improved yield and liquid retention of fish muscle...... in greater intracellular space at 30 and 60 g kg−1 NaCl. CONCLUSION Sodium bicarbonate addition to low-salt solutions can improve yield and flesh quality of fish muscle owing to altered water mobility and wider space between the muscle cells...

  17. A five way crossover human volunteer study to compare the pharmacokinetics of paracetamol following oral administration of two commercially available paracetamol tablets and three development tablets containing paracetamol in combination with sodium bicarbonate or calcium carbonate.

    Science.gov (United States)

    Grattan, T; Hickman, R; Darby-Dowman, A; Hayward, M; Boyce, M; Warrington, S

    2000-05-01

    This report concerns a single dose randomized five way crossover study to compare the pharmacokinetics of paracetamol from two commercially available paracetamol (500 mg) tablets and three different development paracetamol (500 mg) tablet formulations containing either sodium bicarbonate (400 mg), sodium bicarbonate (630 mg) or calcium carbonate (375 mg). The results demonstrated that addition of sodium bicarbonate (630 mg) to paracetamol tablets, increased the rate of absorption of paracetamol relative to conventional paracetamol tablets and soluble paracetamol tablets. Addition of sodium bicarbonate (400 mg) to paracetamol tablets increased the absorption rate of paracetamol relative to conventional paracetamol tablets, but there was no difference in the rate of absorption compared to soluble paracetamol tablets. Inclusion of calcium carbonate (375 mg) to paracetamol tablets had no effect on absorption kinetics compared to the conventional paracetamol tablet. The faster absorption observed for the sodium bicarbonate formulations may be as a result of an increase in gastric emptying rate leading to faster transport of paracetamol to the small intestine where absorption takes place.

  18. Suppression on plant-parasitic nematodes using a soil fumigation strategy based on ammonium bicarbonate and its effects on the nematode community.

    Science.gov (United States)

    Su, Lanxi; Ruan, Yunze; Yang, Xiujuan; Wang, Kang; Li, Rong; Shen, Qirong

    2015-12-01

    Banana production is severely hindered by plant-parasitic nematodes in acidic, sandy soil. This study investigated the possibility of applying a novel fumigation agent based on ammonium bicarbonate as a strategy for controlling plant-parasitic nematodes under sealed conditions. Moreover, its effects on the nematode community in pot and field experiments were also measured using morphology and feeding-habit based classification and the PCR-DGGE method. Results showed that a mixture (LAB) of lime (L) and ammonium bicarbonate (AB) in suitable additive amounts (0.857 g kg(-1) of L and 0.428 g kg(-1) of AB) showed stronger nematicidal ability than did the use of AB alone or the use of ammonium hydroxide (AH) and calcium cyanamide (CC) with an equal nitrogen amount. The nematode community was altered by the different fumigants, and LAB showed an excellent plant-parasitic nematicidal ability, especially for Meloidogyne and Rotylenchulus, as revealed by morphology and feeding-habit based classification, and for Meloidogyne, as revealed by the PCR-DGGE method. Fungivores and omnivore-predators were more sensitive to the direct effects of the chemicals than bacterivores. This study explored a novel fumigation agent for controlling plant-parasitic nematodes based on LAB and provides a potential strategy to ensure the worldwide development of the banana industry.

  19. Ménage-à-trois: The ratio of bicarbonate to CO2 and the pH regulate the capacity of neutrophils to form NETs

    Directory of Open Access Journals (Sweden)

    Christian Maueröder

    2016-12-01

    Full Text Available In this study we identified and characterized the potential of a high ratio of bicarbonate to CO2 and a moderately alkaline pH to render neutrophils prone to undergo neutrophil extracellular trap (NET formation. Both experimental settings increased the rate of spontaneous NET release and potentiated the NET-inducing capacity of phorbol esters (PMA, ionomycin, monosodium urate and LPS. In contrast, an acidic environment impaired neutrophil extracellular trap formation both spontaneous and induced. Our findings indicate that intracellular alkalinization of neutrophils in response to an alkaline environment leads to an increase of intracellular calcium and neutrophil activation. We further found that the anion channel blocker DIDS strongly reduced NET formation induced by bicarbonate. This finding suggests that the effects observed are due to a molecular program that renders neutrophils susceptible to neutrophil extracellular trap formation. Inflammatory foci are characterized by an acidic environment. Our data indicates that NET formation is favored by the higher pH at the border regions of inflamed areas. Moreover our findings highlight the necessity for strict pH control during assays of neutrophil extracellular trap formation.

  20. Influences of Temperature and pH Value on the Corrosion Behaviors of X80 Pipeline Steel in Carbonate/Bicarbonate Buffer Solution

    Institute of Scientific and Technical Information of China (English)

    LI,Jin-Bo; ZUO,Jian-E

    2008-01-01

    The joint effect of temperature and pH value on the corrosion behavior of X80 steel in carbonate/bicarbonate buffer solution was detected by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis. The results show that an unstable corrosion film will be formed on the X80 steel surface in low pH value solutions, and a better protective corrosion film can be formed on the X80 steel surface in high pH value solutions. On the whole, the corrosion film resistance and transfer resistance increase with the increment of pH value, and decrease with increase of solution temperature, which indicates that the protective effect of the corrosion film on X80 steel is enhanced with increasing pH value and decreasing the solution temperature. The corrosion film formed on X80 steel surface in carbonate/bicarbonate buffer solution has an n-type semi-conductive character, and the donor density decreases with increasing the pH value, and increases with increasing the solution temperature. The flat-band potential and pH value have a linear relationship with a positive slope.

  1. Bicarbonate as tracer for plant assimilated C and homogeneity of 14C and 15N distribution in ryegrass and white clover tissue by alternative labeling approaches

    DEFF Research Database (Denmark)

    Rasmussen, Jim; Kusliene, Gedrime; Jacobsen, Ole Stig;

    2013-01-01

    Aims: Application of carbon (C) and nitrogen (N) isotopes is an essential tool to study C and N flows in plant-soil-microorganisms systems. When targeting single plants in a community the tracers need to be added via e.g., leaf-labeling or stem-feeding approaches. In this study we: (i) investigated...... parts with high and low 14C activity were separated and analyzed for 15N enrichment. Results Bicarbonate applied by leaf-labeling efficiently introduced 14C into both white clover and ryegrass, although the 14C activity in particular for white clover was found predominantly in the labeled leaf. Using 14...... that 15N also had a heterogeneous distribution (up to two orders of magnitude). Conclusion Bicarbonate can efficiently be used to introduce 14C or 13C into plant via the leaf-labeling method. Both 14C and 15N showed heterogeneous distribution in the plant, although the distribution of 15N was more even...

  2. Suppression on plant-parasitic nematodes using a soil fumigation strategy based on ammonium bicarbonate and its effects on the nematode community

    Science.gov (United States)

    Su, Lanxi; Ruan, Yunze; Yang, Xiujuan; Wang, Kang; Li, Rong; Shen, Qirong

    2015-01-01

    Banana production is severely hindered by plant-parasitic nematodes in acidic, sandy soil. This study investigated the possibility of applying a novel fumigation agent based on ammonium bicarbonate as a strategy for controlling plant-parasitic nematodes under sealed conditions. Moreover, its effects on the nematode community in pot and field experiments were also measured using morphology and feeding-habit based classification and the PCR-DGGE method. Results showed that a mixture (LAB) of lime (L) and ammonium bicarbonate (AB) in suitable additive amounts (0.857 g kg−1 of L and 0.428 g kg−1 of AB) showed stronger nematicidal ability than did the use of AB alone or the use of ammonium hydroxide (AH) and calcium cyanamide (CC) with an equal nitrogen amount. The nematode community was altered by the different fumigants, and LAB showed an excellent plant-parasitic nematicidal ability, especially for Meloidogyne and Rotylenchulus, as revealed by morphology and feeding-habit based classification, and for Meloidogyne, as revealed by the PCR-DGGE method. Fungivores and omnivore-predators were more sensitive to the direct effects of the chemicals than bacterivores. This study explored a novel fumigation agent for controlling plant-parasitic nematodes based on LAB and provides a potential strategy to ensure the worldwide development of the banana industry. PMID:26621630

  3. A study of X100 pipeline steel passivation in mildly alkaline bicarbonate solutions using electrochemical impedance spectroscopy under potentiodynamic conditions and Mott-Schottky

    Science.gov (United States)

    Gadala, Ibrahim M.; Alfantazi, Akram

    2015-12-01

    The key steps involved in X100 pipeline steel passivation in bicarbonate-based simulated soil solutions from the pre-passive to transpassive potential regions have been analyzed here using a step-wise anodizing-electrochemical impedance spectroscopy (EIS) routine. Pre-passive steps involve parallel dissolution-adsorption in early stages followed by clear diffusion-adsorption control shortly before iron hydroxide formation. Aggressive NS4 chlorides/sulfate promote steel dissolution whilst inhibiting diffusion in pre-passive steps. Diffusive and adsorptive effects remain during iron hydroxide formation, but withdraw shortly thereafter during its removal and the development of the stable iron carbonate passive layer. Passive layer protectiveness is evaluated using EIS fitting, current density analysis, and correlations with semiconductive parameters, consistently revealing improved robustness in colder, bicarbonate-rich, chloride/sulfate-free conditions. Ferrous oxide formation at higher potentials results in markedly lower impedances with disordered behavior, and the involvement of the iron(III) valence state is observed in Mott-Schottky tests exclusively for 75 °C conditions.

  4. Factors affecting the synergy of thiabendazole, sodium bicarbonate, and heat to control postharvest green mold of citrus fruit.

    Science.gov (United States)

    Schirra, Mario; D'Aquino, Salvatore; Palma, Amedeo; Angioni, Alberto; Cabras, Paolo

    2008-11-26

    The efficacy of thiabendazole (TBZ) to control postharvest decay caused by Penicillium digitatum of citrus fruit can be enhanced by co-application with sodium bicarbonate (SBC) and/or heat treatment. The impact of these treatments was investigated in citrus fruit, as a function of TBZ and SBC concentration and temperature, and were related to the amount of TBZ residues in fruit (total residues), in fruit surface, in the cuticular wax, and in the inner fruit. The residue levels of TBZ were determined in 'Valencia' oranges following a 1 min dip in an aqueous mixture of SBC at 0.5, 1, or 2 wt %/vol and TBZ at 600 or 400 mg/L (active ingredient, a.i.) at 20 or 40 degrees C and after 0 and 20 days at 17 degrees C and 90% relative humidity. The influence of SBC and heat on the TBZ residue concentration on the fruit surface, in cuticular wax, and on the inner cuticle tissue was determined in 'Salustiana' oranges after a 1 or 3 min dip in TBZ alone at 600 mg/L and 20 or 50 degrees C or for 1 min in TBZ at 600 mg/L and SBC at 2% and 20 degrees C. The efficacy of heat treatments with water, SBC, and TBZ, applied separately or in combination, was investigated on artificially inoculated 'Nova' mandarins and 'Valencia' oranges for the control of postharvest green mold caused by a TBZ-sensitive (TBZ-s) or TBZ-resistant (TBZ-r) isolate of P. digitatum. The residue levels of TBZ in fruit, evaluated as total residues, were not affected by the co-application of SBC in most samples. While TBZ residues in the fruit surface were not significantly affected by the dip temperature or by co-application of SBC, the rates of diffusion and penetration of TBZ into cuticular wax markedly increased in the presence of SBC or when TBZ was applied in combination with heat. TBZ residues in the inner tissue of fruits treated at 20 degrees C were not dependent upon the dip time or by the presence of SBC and were similar to those found in fruit treated with TBZ at 50 degrees C for 1 min, whereas

  5. Evaluation of the oral 13C-bicarbonate technique for measurements of energy expenditure in dogs before and after body weight reduction

    DEFF Research Database (Denmark)

    Larsson, Caroline; Vitger, Anne; Jensen, Rasmus Bovbjerg

    2014-01-01

    BackgroundOverweight and obesity are the most common nutritional disorders in dogs and may lead to various secondary diseases and decreased lifespan. In obesity research, measurement of energy expenditure (EE) and determination of the energy requirements are essential. The objective with this study...... was to validate and evaluate the suitability of the oral 13C-bicarbonate technique (o13CBT) for measuring EE in dog obesity studies. A further objective was to investigate the impact of body weight (BW) reduction and changes in body composition on the EE when measured under conditions corresponding to the basal...... metabolic rate (BMR).ResultsThe EE in five privately owned, overweight dogs was measured simultaneously with the o13CBT and indirect calorimetry (IC) for comparison of the results. Two measurements per dog were performed under the same standardised conditions (i.e. fasted and resting state) at the start...

  6. Comparison of end-tidal carbon dioxide and arterial blood bicarbonate levels in patients with metabolic acidosis referred to emergency medicine

    Science.gov (United States)

    Taghizadieh, Ali; Pouraghaei, Mahboub; Moharamzadeh, Payman; Ala, Alireza; Rahmani, Farzad; Basiri Sofiani, Karim

    2016-01-01

    Introduction: The routine and gold standard method to diagnose of acid – base disturbance is arterial blood gas (ABG) sampling. Capnography could be used to measure the end-tidal carbon dioxide (ETCO2) levels and ETco2 has a close correlation with the PaCo2. The aim of this study was comparison the ETco2 and arterial blood bicarbonate levels in patients with metabolic acidosis. Methods: In a descriptive-analytical study that performed in Emergency Department of Emam Reza Medical Research and Training Hospital of Tabriz on patients with metabolic acidosis, ETco2 level and blood bicarbonate levels in 262 patients were evaluated. Results: Mean of ETco2 and Hco3 levels in patients with metabolic acidosis were 22.29 ± 4.15 and 12.78 ± 3.83, respectively. In all patients, the significant direct linear relationship was found between ETco2 with Hco3 (r = 0.553, P < 0.001). We had 4 groups of patients with metabolic acidosis, also there is a significant direct linear relationship between the ETCo2 and the Hco3 level of arterial blood in patients with renal failure (P < 0.001 and r = 0.551), sepsis (P < 0.001 and r = 0.431), drug toxicity (P < 0.001 and r = 0.856), and ketoacidosis (DKA) (P < 0.001 and r = 0.559). Conclusion: According to the results of this study, capnography can be used for primary diagnosis of metabolic acidosis in spontaneously breathing patients who referred to the emergency wards, however, the ABG must be considered as the gold standard tool for diagnosis and guiding the treatment. PMID:27777693

  7. Evaluation of stainless steel cathodes and a bicarbonate buffer for hydrogen production in microbial electrolysis cells using a new method for measuring gas production

    KAUST Repository

    Ambler, Jack R.

    2011-01-01

    Microbial electrolysis cells (MECs) are often examined for hydrogen production using non-sustainable phosphate buffered solutions (PBS), although carbonate buffers have been shown to work in other bioelectrochemical systems with a platinum (Pt) catalyst. Stainless steel (SS) has been shown to be an effective catalyst for hydrogen evolution in MECs, but it has not been tested with carbonate buffers. We evaluated the combined using of SS cathodes and a bicarbonate buffer (BBS) at the applied voltages of 0.5, 0.7 and 0.9 V using a new inexpensive method for measuring gas production called the gas bag method (GBM). This method achieved an average error of only 5.0% based on adding known volumes of gas to the bag. Using the GBM, hydrogen production with SS and a BBS was 26.6 ± 1.8 mL which compared well to 26.4 ± 2.8 mL using Pt and BBS, and 26.8 ± 2.5 mL with a Pt cathode and PBS. Electrical energy efficiency was highest with a SS cathode and BBS at 159 ± 17%, compared to 126 ± 14% for the Pt cathode and BBS, and 134 ± 17% for a Pt cathode and PBS. The main disadvantage of the SS was a lower gas production rate of 1.1 ± 0.3 m3 H2-m-3 d-1 with BBS and 1.2 ± 0.3 m3 H2-m-3 d -1 with PBS, compared to 1.7 ± 0.4 m3 H 2-m-3 d-1 with Pt and PBS. These results show that the GBM is an effective new method for measuring gas production of anaerobic gas production processes, and that SS and bicarbonate buffers can be used to effectively produce hydrogen in MECs. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

  8. Intraocular Irrigating Solutions. A Clinical Study of BSS Plus ® and Dextrose Bicarbonate Fortified BSS ® as an Infusate during Pars Plana Vitrectomy.

    Directory of Open Access Journals (Sweden)

    Samuel Michael

    2003-01-01

    Full Text Available Purpose: To compare the effect of Balanced Salt Solution Plus (BSS Plus, Alcon Laboratories, Fort Worth, Texas, USA and fortified regular BSS on the cornea and lens, when used for continuous irrigation in pars plana vitrectomy (PPV surgery. Methods: Prospective, investigator masked, randomised study. Forty patients were randomly assigned to undergo PPV using BSS Plus (n=20 or fortified BSS (n=20 [regular BSS, fortified with 10.5 cc. of dextrose in water (D5W and 13.1cc. of 8.4% sodium bicarbonate]. Intraoperative features of the corneal epithelium, postoperative changes in the corneal endothelial cell denstiy (ECD at 3 months, and clarity of the lens during surgery and postoperatively were evaluated. Results: Intraoperative epithelial changes were similar in both groups with 7 (35% of the cases having the epithelium removed in the BSS Plus group and 8 (40% in the BSS fortified group (P=0.23. The mean differences in ECD (3 months versus preoperative in the operated eyes when adjusted for changes in the control eye showed no difference with the type of BSS (P=0.98. Intraoperative lens changes were more significant (P=0.018 in the BSS fortified group. Postoperative lens status at 3 months was similar for both groups. Though there was a trend towards worse postoperative nuclear sclerosis change in the BSS fortified group, it was not significant (P=0.160. Conclusion: Standard BSS fortified with dextrose and bicarbonate is an efficacious infusion fluid during pars plana vitrectomy. Both solutions showed comparable effects on postoperative corneal endothelial cell density and corneal epithelial changes intraoperatively. BSS fortified has more lenticular changes intraoperatively than BSS Plus although no lens had to be removed in either group. The study implications are important since BSS fortified is significantly less expensive than BSS Plus.

  9. Dry process of smokes treatment with sodium bicarbonate and the recycling of sodic wastes; Proceso seco de depuracion de humos con bicarbonato sodico de reciclado de productos sodicos residuales

    Energy Technology Data Exchange (ETDEWEB)

    Catalan, X.

    1996-12-01

    The Neutrec process of Solvay for the acid emissions treatment by sodium bicarbonate is using in Belgium, France, Italy, The Netherland and Spain. there are 28 facilities for the smokes treatment. these smokes are coming from the urban, sanitary and hazardous wastes. The Neutrec process is using dry reactive for neutralizing the acid smoker. (Author)

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

    Science.gov (United States)

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

    2014-01-01

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

  11. Stimulation of gastric bicarbonate secretion by an analog of thyrotropin-releasing hormone, YM-14673, in the rat.

    Science.gov (United States)

    Takeuchi, K; Ueshima, K; Okabe, S

    1991-03-01

    The effects of YM-14673, a thyrotropin-releasing hormone analog, on gastric alkaline secretion were investigated in the anesthetized rat pretreated with omeprazole (60 mg/kg, intraperitoneally) by measuring the luminal pH, transmucosal PD and HCO3- output. The whole stomach was perfused at a flow rate of 0.7 ml/min with saline (pH 4.5) in the absence of acid secretion, the pH of the perfusate and PD were continuously monitored and the HCO3- output was measured as acid-neutralizing capacity by back-titration of the perfusate to pH 4.5. YM-14673, given intravenously at the doses (0.1-1 mg/kg) that stimulated acid secretion, increased the pH and HCO3- output in a dose-dependent fashion, but did not significantly affect the PD. Prostaglandin E2 (1 mg/kg) elevated the pH and HCO3- output with concomitant decrease in the PD, whereas carbachol (4 micrograms/kg), similar to YM-14673, produced an increase of the pH and HCO3- output with no change in the PD. The net HCO3- output (4.3 +/- 0.3 muEq) induced by 0.3 mg/kg of YM-14673 was about 60 and 150% of that induced by prostaglandin E2 and carbachol, respectively. The increased pH and HCO3- responses caused by YM-14673 were almost completely abolished by vagotomy, significantly inhibited by atropine (0.3 mg/kg, intravenously) and indomethacin (5 mg/kg, subcutaneously) but not affected by pirenzepine (1 mg/kg, intravenously). These results suggest that YM-14673, a thyrotropin-releasing hormone analog, produced vagally mediated HCO3- secretion in the rat stomach, and the mechanism may involve the cholinergic system, which is mediated with muscarinic M2 receptors and interacts with endogenous prostaglandins.

  12. Entry and exit pathways of CO2 in rat liver mitochondria respiring in a bicarbonate buffer system.

    Science.gov (United States)

    Balboni, E; Lehninger, A L

    1986-03-15

    The dynamics and pathways of CO2 movements across the membranes of mitochondria respiring in vitro in a CO2/HCO-3 buffer at concentrations close to that in intact rat tissues were continuously monitored with a gas-permeable CO2-sensitive electrode. O2 uptake and pH changes were monitored simultaneously. Factors affecting CO2 entry were examined under conditions in which CO2 uptake was coupled to electrophoretic influx of K+ (in the presence of valinomycin) or Ca2+. The role of mitochondrial carbonic anhydrase (EC 4.2.1.1) in CO2 entry was evaluated by comparison of CO2 uptake by rat liver mitochondria, which possess carbonic anhydrase, versus rat heart mitochondria, which lack carbonic anhydrase. Such studies showed that matrix carbonic anhydrase activity is essential for rapid net uptake of CO2 with K+ or Ca2+. Studies with acetazolamide (Diamox), a potent inhibitor of carbonic anhydrase, confirmed the requirement of matrix carbonic anhydrase for net CO2 uptake. It was shown that at pH 7.2 the major species leaving respiring mitochondria is dissolved CO2, rather than HCO-3 or H2CO3 suggested by earlier reports. Efflux of endogenous CO2/HCO-3 is significantly inhibited by inhibitors of the dicarboxylate and tricarboxylate transport systems of the rat liver inner membrane. The possibility that these anion carriers mediate outward transport of HCO-3 is discussed.

  13. mediation: R Package for Causal Mediation Analysis

    Directory of Open Access Journals (Sweden)

    Dustin Tingley

    2014-09-01

    Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.

  14. Bayesian Mediation Analysis

    Science.gov (United States)

    Yuan, Ying; MacKinnon, David P.

    2009-01-01

    In this article, we propose Bayesian analysis of mediation effects. Compared with conventional frequentist mediation analysis, the Bayesian approach has several advantages. First, it allows researchers to incorporate prior information into the mediation analysis, thus potentially improving the efficiency of estimates. Second, under the Bayesian…

  15. Mediation as Signal

    NARCIS (Netherlands)

    Holler, M.J.; Lindner, I.

    2004-01-01

    This paper analyzes mediation as a signal. Starting from a stylized case, a game theoretical model of one-sided incomplete information, taken from Cho and Kreps (1987), is applied to discuss strategic effects of mediation. It turns out that to reject mediation can be interpreted as a ”negative signa

  16. Sodium bicarbonate use and the risk of hypernatremia in thoracic aortic surgical patients with metabolic acidosis following deep hypothermic circulatory arrest

    Directory of Open Access Journals (Sweden)

    Kamrouz Ghadimi

    2016-01-01

    Full Text Available Objective: Metabolic acidosis after deep hypothermic circulatory arrest (DHCA for thoracic aortic operations is commonly managed with sodium bicarbonate (NaHCO 3 . The purpose of this study was to determine the relationships between total NaHCO 3 dose and the severity of metabolic acidosis, duration of mechanical ventilation, duration of vasoactive infusions, and Intensive Care Unit (ICU or hospital length of stay (LOS. Methods: In a single center, retrospective study, 87 consecutive elective thoracic aortic operations utilizing DHCA, were studied. Linear regression analysis was used to test for the relationships between the total NaHCO 3 dose administered through postoperative day 2, clinical variables, arterial blood gas values, and short-term clinical outcomes. Results: Seventy-five patients (86% received NaHCO 3 . Total NaHCO 3 dose averaged 136 ± 112 mEq (range: 0.0-535 mEq per patient. Total NaHCO 3 dose correlated with minimum pH (r = 0.41, P < 0.0001, minimum serum bicarbonate (r = −0.40, P < 0.001, maximum serum lactate (r = 0.46, P = 0.007, duration of metabolic acidosis (r = 0.33, P = 0.002, and maximum serum sodium concentrations (r = 0.29, P = 0.007. Postoperative hypernatremia was present in 67% of patients and peaked at 12 h following DHCA. Eight percent of patients had a serum sodium ≥ 150 mEq/L. Total NaHCO 3 dose did not correlate with anion gap, serum chloride, not the duration of mechanical ventilator support, vasoactive infusions, ICU or hospital LOS. Conclusion: Routine administration of NaHCO 3 was common for the management of metabolic acidosis after DHCA. Total dose of NaHCO 3 was a function of the severity and duration of metabolic acidosis. NaHCO 3 administration contributed to postoperative hypernatremia that was often severe. The total NaHCO 3 dose administered was unrelated to short-term clinical outcomes.

  17. Influence of bicarbonate and humic acid on effects of chronic waterborne lead exposure to the fathead minnow (Pimephales promelas).

    Science.gov (United States)

    Mager, Edward M; Brix, Kevin V; Grosell, Martin

    2010-01-31

    Historically, the USEPA has only considered water hardness when establishing acute and chronic water quality criteria (WQC) for lead (Pb) in freshwater. Yet, recent evidence suggests that hardness may not be protective during chronic Pb exposure and that other factors (e.g., dissolved organic carbon (DOC) and alkalinity) influence toxicity. In fact, we have recently shown that Ca(2+) (as CaSO(4)) does not protect against Pb accumulation in fathead minnows (Pimephales promelas) during chronic exposures whereas DOC as humic acid (HA) clearly does. To more clearly define the water chemistry parameters mediating chronic Pb toxicity we carried out 300 d exposures to study the influence of DOC and alkalinity on Pb accumulation and toxicity to fathead minnows at 2 different Pb concentrations (170 and 580 nM (35 and 120 microg/L)). Alkalinity was adjusted by addition of 500 microM NaHCO(3) and DOC by addition of 4 mg/L HA. Fish were collected at 4, 30, 150 and 300 d of exposure to measure growth and Pb accumulation. Breeding assays (21 d) were performed at the end of these exposures to assess reproductive and larval behavioral endpoints. To determine whether effects were acute or chronic, switched breeding exposures were performed in which control breeders were transferred to either high or low Pb conditions and Pb-exposed breeders transferred to tap water without Pb. Mortality and growth effects were observed primarily in the high Pb treatments and within the first 10 d of exposure. Strong protection against Pb accumulation was afforded by increased DOC at both Pb concentrations. Increased alkalinity also appeared to moderately reduce Pb accumulation although not to the level of statistical significance. Tissue distribution of Pb was analyzed at 300 d and was found to accumulate mostly in bone, gill, intestine and kidney. Unexpectedly, high Pb reduced total reproductive output and increased average egg mass in the HCO(3)(-) and DOC treatments but not in the control water

  18. Controlled leaching with prolonged activity for Co-LDH supported catalyst during treatment of organic dyes using bicarbonate activation of hydrogen peroxide.

    Science.gov (United States)

    Jawad, Ali; Li, Yibing; Lu, Xiaoyan; Chen, Zhuqi; Liu, Weidong; Yin, Guochuan

    2015-05-30

    The effluents from industries are commonly non-biodegradable and produce various hazardous intermediate products by chemical reactions that have direct impact on environment. In the present investigation, a series of Co-Mg/AL ternary LDH catalysts with fixed Mg/Al ratio were prepared by co-precipitation method. The effect of Co on the activity of the catalyst was monitored on the degradation of methylene blue (MB) as model compound at batch level using bicarbonate activation of H2O2 (BAP) system. On bench level, the best CoMgAl-4 catalyst can completely decolorize both methylene blue (MB) and methylene orange (MO) in short time, while in fixed bed, the catalyst was found stable for over 300 h with nearly 100% decolorization and excellent chemical oxygen demand (COD) removal. No leaching of Co was detected for the entire fixed experiment which may be accounted for long life stability and good activity of the catalyst. The ternary LDH catalysts were characterized by AES, XRD, FTIR, BET, and SEM for its compositional, phase structure, optical properties, textural, and surface morphology respectively. The XRD analysis confirmed characteristic pattern of hydrotalcite like structures without impurity phases. The formation of superoxide and hydroxyl radical as ROS was proposed with CoMgAl-4 by radical's scavengers.

  19. Scientific Opinion on the safety assessment of the active substances, sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulphate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, for use as active system in food contact materials

    OpenAIRE

    2014-01-01

    This scientific opinion of EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, used in mixture which is packed into sachets for absorbing oxygen/carbon dioxide emitting from/into the headspace surrounding packed food. All substances of this formulation have been e...

  20. 钆元素在碳酸钠、碳酸氢铵溶液中溶解性研究%Study of Solubility of Gadolinium in Sodium Carbonate and Ammonium Bicarbonate Solution

    Institute of Scientific and Technical Information of China (English)

    赵永志; 郝先库; 张瑞祥; 胡珊珊; 马显东; 许宗泽

    2013-01-01

    In this paper, the solubility of gadolinium in sodium carbonate and ammonium bicarbonate was studied. As a result, the solubility increased then decreased with reaction time. The solubility was improved by increasing carbonate concentration. With the increasing temperature, the solubility increased in sodium carbonate but decreased in ammonium bicarbonate solution. The solubility of gadolinium increased in anmmonium bicarbonate but decreased in sodium carbonate with addition of ammonium hydroxide.%研究了钆元素在碳酸钠、碳酸氢铵溶液中的溶解性.钆元素在碳酸钠、碳酸氢铵溶液中随着反应时间的延长溶解量先增大后减小;提高碳酸钠和碳酸氢铵浓度也可以增加钆元素的溶解量;反应温度对钆元素在碳酸钠和碳酸氢铵溶液中的溶解性影响不同,表现为温度升高,钆在碳酸氢铵溶液中的溶解量减小,在碳酸钠溶液中增大.在碳酸氢铵溶液中加入氨水可以增大钆的溶解量,而在碳酸钠溶液中加入氢氧化钠使钆的溶解量减小.

  1. The effect of low serum bicarbonate values on the onset of action of local anesthesia with vertical infraclavicular brachial plexus block in patients with End-stage renal failure

    Directory of Open Access Journals (Sweden)

    Al-mustafa Mahmoud

    2010-01-01

    Full Text Available Vertical infraclavicular brachial plexus block is utilized in patients with chronic renal failure at the time of creation of an arterio-venous fistula (AVF. The aim of this study is to test the effect of impaired renal function, with the resulting deranged serum electrolytes and blood gases, on the success rate and the onset of action of the local anesthetics used. In this prospective clinical study, we investigated the effect of the serum levels of sodium, potassium, urea, crea-tinine, pH, and bicarbonate on the onset of action of a mixture of lidocaine and bupivacaine administered to create infraclavicular brachial plexus block. A total of 31 patients were studied. The success rate of the block was 93.5 % (29 patients. The mean onset time for impaired or re-duced sensation was found to be 8.9 ± 4.7 mins and for complete loss of sensation, was 21.2 ± 6.7 mins. There was no significant association with serum sodium, potassium, urea, creatinine or the blood pH level (P> 0.05. The bivariate correlation between serum bicarbonate level and the partial and complete sensory loss was -0.714 and -0.433 respectively, with significant correlation (P= 0.00, 0.019. Our study suggests that infraclavicular block in patients with chronic renal failure carries a high success rate; the onset of the block is delayed in patients with low serum bicarbonate levels.

  2. Technology-Use Mediation

    DEFF Research Database (Denmark)

    Bansler, Jørgen P.; Havn, Erling C.

    2003-01-01

    This study analyzes how a group of ‘mediators’ in a large, multinational company adapted a computer-mediated communication technology (a ‘virtual workspace’) to the organizational context (and vice versa) by modifying features of the technology, providing ongoing support for users, and promoting...... of technology-use mediation is more complex and indeterminate than earlier literature suggests. In particular, we want to draw attention to the fact that advanced computer-mediated communication technologies are equivocal and that technology-use mediation consequently requires ongoing sensemaking (Weick 1995)....... appropriate conventions of use. Our findings corroborate earlier research on technology-use mediation, which suggests that such mediators can exert considerable influence on how a particular technology will be established and used in an organization. However, this study also indicates that the process...

  3. Bicarbonate concentration and osmolality are key determinants in the inhibition of CHO cell polysialylation under elevated pCO(2) or pH.

    Science.gov (United States)

    Zanghi, J A; Schmelzer, A E; Mendoza, T P; Knop, R H; Miller, W M

    1999-10-20

    Accumulation of CO(2) in animal cell cultures can be a significant problem during scale-up and production of recombinant glycoprotein biopharmaceuticals. By examining the cell-surface polysialic acid (PSA) content, we show that elevated CO(2) partial pressure (pCO(2)) can alter protein glycosylation. PSA is a high-molecular-weight polymer attached to several complex N-linked oligosaccharides on the neural cell adhesion molecule (NCAM), so that small changes in either core glycosylation or in polysialylation are amplified and easily measured. Flow-cytometric analysis revealed that PSA levels on Chinese hamster ovary (CHO) cells decrease with increasing pCO(2) in a dose-dependent manner, independent of any change in NCAM content. The results are highly pH-dependent, with a greater decrease in PSA at higher pH. By manipulating medium pH and pCO(2), we showed that decreases in PSA correlate well with bicarbonate concentration ([HCO(3)(-)]). In fact, it was possible to offset a 60% decrease in PSA content at 120 mm Hg pCO(2) by decreasing the pH from 7.3 to 6.9, such that [HCO(3)(-)] was lowered to that of control (38 mm Hg pCO(2)). When the increase in osmolality associated with elevated [HCO(3)(-)] was offset by decreasing the basal medium [NaCl], elevated [HCO(3)(-)] still caused a decrease in PSA, although less extensive than without osmolality control. By increasing [NaCl], we show that hyperosmolality alone decreases PSA content, but to a lesser extent than for the same osmolality increase due to elevated [NaHCO(3)]. In conclusion, we demonstrate the importance of pH and pCO(2) interactions, and show that [HCO(3)(-)] and osmolality can account for the observed changes in PSA content over a wide range of pH and pCO(2) values.

  4. Plant Protein Intake Is Associated with Fibroblast Growth Factor 23 and Serum Bicarbonate in Patients with CKD: The Chronic Renal Insufficiency Cohort Study

    Science.gov (United States)

    Scialla, Julia J.; Appel, Lawrence J; Wolf, Myles; Yang, Wei; Zhang, Xiaoming; Sozio, Stephen M.; Miller, Edgar R.; Bazzano, Lydia A.; Cuevas, Magdalena; Glenn, Melanie J.; Lustigova, Eva; Kallem, Radhakrishna R.; Porter, Anna C.; Townsend, Raymond R.; Weir, Matthew R.; Anderson, Cheryl A.M.

    2012-01-01

    Background Protein from plant, as opposed to animal, sources may be preferred in chronic kidney disease (CKD), due to lower bioavailability of phosphate and lower nonvolatile acid load. Study Design Observational cross-sectional study. Setting & Participants 2938 participants with chronic kidney disease and information on dietary intake at the baseline visit in the Chronic Renal Insufficiency Cohort Study. Predictors Percentage of total protein from plant sources (% plant protein) was determined by scoring individual food items from the National Cancer Institute Diet History Questionnaire (DHQ). Outcomes Metabolic parameters, including serum phosphate, bicarbonate (HCO3), potassium, and albumin, plasma fibroblast growth factor 23 (FGF23), and parathyroid hormone (PTH), and hemoglobin. Measurements We modeled the association between % plant protein and metabolic parameters using linear regression. Models were adjusted for age, sex, race, diabetes, body mass index, eGFR, income, smoking, total energy intake, total protein intake, 24 hour urinary sodium, use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers and use of diuretics. Results Higher % plant protein was associated with lower FGF23 (p=0.05) and higher HCO3 (p=0.01), but not with serum phosphate or PTH (p=0.9 and 0.5, respectively). Higher % plant protein was not associated with higher serum potassium (p=0.2), lower serum albumin (p=0.2) or lower hemoglobin (p=0.3). The associations of % plant protein with FGF23 and HCO3 did not differ by diabetes status, sex, race, CKD stage (2/3 vs. 4/5) or total protein intake (≤ 0.8 g/kg/d vs. >0.8 g/kg/d) (p-interaction > 0.10 for each). Limitations Cross-sectional study; Determination of % plant protein using the DHQ has not been validated. Conclusions Consumption of a higher percentage of protein from plant sources may lower FGF23 and raise HCO3 in patients with CKD. PMID:22480598

  5. A randomized, crossover pharmacodynamic study of immediate-release omeprazole/sodium bicarbonate and delayed-release lansoprazole in healthy adult volunteers.

    Science.gov (United States)

    Pratha, Vijayalakshmi S; McGraw, Thomas; Tobin, William

    2016-06-01

    Proton pump inhibitors (PPIs) effectively block gastric acid secretion and are the treatment of choice for heartburn. PPIs differ, however, in onset of action and bioavailability. In this single-center, open-label, three-way crossover study, onset of action of immediate-release omeprazole 20 mg/sodium bicarbonate 1100 mg (IR-OME) and delayed-release (DR) lansoprazole 15 mg was evaluated in 63 healthy fasting adults. Subjects were randomized to once daily IR-OME, or DR-lansoprazole, or no treatment for 7 days. The primary efficacy endpoint was the earliest time where a statistically significant difference was observed between IR-OME and DR-lansoprazole in median intragastric pH scores for three consecutive 5-min intervals on day 7. Secondary endpoints compared effects of active treatments on days 1 and 7 (e.g., time to sustained inhibition, percentage of time with pH >4). A significant difference in median intragastric pH favoring IR-OME was observed on day 7 starting at the 10- to 15-min interval postdosing (P = 0.024) and sustaining through the 115- to 120-min interval (P = 0.017). On day 1, IR-OME achieved sustained inhibition of intragastric acidity significantly faster than DR-lansoprazole. IR-OME maintained pH >4 significantly longer than DR-lansoprazole over a 24-h period (P = 0.007) on day 7. Overall, results of this study demonstrate IR-OME is safe and well tolerated and that treatment with IR-OME results in significantly faster onset of action and better gastric acid suppression at steady state than DR-lansoprazole.

  6. The role of aspartic acid residues 405 and 416 of the kidney isotype of sodium-bicarbonate cotransporter 1 in its targeting to the plasma membrane

    Science.gov (United States)

    Kucher, Volodymyr; Li, Emily Y.; Conforti, Laura; Zahedi, Kamyar A.

    2012-01-01

    The NH2 terminus of the sodium-bicarbonate cotransporter 1 (NBCe1) plays an important role in its targeting to the plasma membrane. To identify the amino acid residues that contribute to the targeting of NBCe1 to the plasma membrane, polarized MDCK cells were transfected with expression constructs coding for green fluorescent protein (GFP)-tagged NBCe1 NH2-terminal deletion mutants, and the localization of GFP-tagged proteins was analyzed by confocal microscopy. Our results indicate that the amino acids between residues 399 and 424 of NBCe1A contain important sequences that contribute to its localization to the plasma membrane. Site-directed mutagenesis studies showed that GFP-NBCe1A mutants D405A and D416A are retained in the cytoplasm of the polarized MDCK epithelial cells. Examination of functional activities of D405A and D416A reveals that their activities are reduced compared with the wild-type NBCe1A. Similarly, aspartic acid residues 449 and 460 of pancreatic NBCe1 (NBCe1B), which correspond to residues 405 and 416 of NBCe1A, are also required for its full functional activity and accurate targeting to the plasma membrane. In addition, while replacement of D416 with glutamic acid did not affect the targeting or functional activity of NBCe1A, substitution of D405 with glutamic acid led to the retention of the mutated protein in the intracellular compartment and impaired functional activity. These studies demonstrate that aspartic acid residues 405 and 416 in the NH2 terminus of NBCe1A are important in its accurate targeting to the plasma membrane. PMID:22442137

  7. Dynamic public service mediation

    NARCIS (Netherlands)

    Hofman, W.; Staalduinen, M. van

    2010-01-01

    This paper presents an approach to dynamic public service mediation. It is based on a conceptual model and the use of search and ranking algorithms. The conceptual model is based on Abstract State Machine theory. Requirements for dynamic service mediation were derived from a real-world case. The con

  8. Teaching Mediated Public Relations.

    Science.gov (United States)

    Kent, Michael L.

    2001-01-01

    Discusses approaches to teaching a mediated public relations course, emphasizing the World Wide Web. Outlines five course objectives, assignments and activities, evaluation, texts, and lecture topics. Argues that students mastering these course objectives will understand ethical issues relating to media use, using mediated technology in public…

  9. Ruimte voor mediation

    NARCIS (Netherlands)

    Combrink-Kuiters, L.; Niemeijer, E.; Voert, M. ter

    2003-01-01

    Dit onderzoek is samen met ADR en mediation Rechterlijke macht gepubliceerd. Het doel was enerzijds na te gaan of, en onder welke condities, mediation in de Nederlandse context een effectief en efficiënt alternatief is voor de gerechtelijke geschillenbeslechting. Anderzijds inzicht te verwerven in d

  10. Music, Radio, and Mediatization

    DEFF Research Database (Denmark)

    Krogh, Mads; Michelsen, Morten

    2016-01-01

    Mediatization has become a key concept for understanding the relations between media and other cultural and social fields. Contributing to the discussions related to the concept of mediatization, this article discusses how practices of radio and music(al life) influence each other. We follow Deacon......’s and Stanyer’s advice to supplement the concept of mediatization with ‘a series of additional concepts at lower levels of abstraction’ and suggest, in this respect, the notion of heterogeneous milieus of music– radio. Hereby, we turn away from the all-encompassing perspectives related to the concept...... of mediatization where media as such seem to be ascribed agency. Instead, we consider historical accounts of music–radio in order to address the complex non- linearity of concrete processes of mediatization as they take place in the multiple meetings between a decentred notion of radio and musical life....

  11. The Schizosaccharomyces pombe Mediator

    DEFF Research Database (Denmark)

    Venturi, Michela

    In the past several years great attention has been dedicated to the characterization of the Mediator complex in a different range of model organisms. Mediator is a conserved co-activator complex involved in transcriptional regulation and it conveys signals from regulatory transcription factors......+ is a nonessential gene, while deletion of med11+ resulted in unviable cells. These results are in line with those obtained in S. cerevisiae. Isolation of S. pombe Mediator by the tandem affinity purification method and Co-IP experiments lead to the conclusion that Med9 and Med11 might not belong to the Mediator...... complex, but our results did not exclude it completely either. Our attempts to demonstrate the presence of these two subunits in the Mediator complex remain inconclusive primarily due to the lack of proper expression of the tagged versions of the proteins. However, we have paved a way to further...

  12. 利用 13C NMR 技术探究叔胺溶液中%Investigation of formation of bicarbonate in tertiary amines using 13C NMR technique

    Institute of Scientific and Technical Information of China (English)

    张瑞; 李末霞; 罗潇; 梁志武

    2015-01-01

    The amount of bicarbonate is a very important factor for energy consumption in solvent regeneration in CO2 capture process. More bicarbonate in rich amines will lead to lower energy cost in CO2 desorption process. To get a preciously knowledge of the formation of bicarbonate in tertiary amines for design a better absorbent for CO2 capture, a series of tertiary amines such as N-diethylethanolamine (DEEA),1-dimethylamino-2-propanol (1DMA2P), 1-diethylamino-2-propanol (1DEA2P), 3-dimethyl-amino-1-propanol (3DMA1P), N-methyldiethanolamine (MDEA), dimethylmonoethanolamine (DMMEA) and triethanolamine (TEA) with various CO2 loading at 1 mol·L?1 were investigated using 13C NMR technology at 293.15 K. The amount of bicarbonate was calculated by the chemical shift of bicarboante/carboante in 13C NMR spectra. The results showed that the order of the amount of bicarbonate in those tertiary amines is DMMEA>MDEA>3DMA1P>1DMA2P>TEA>DEEA>1DEA2P. Considering the effects of electron density of nitrogen atom (N) and the steric hinderance in those tertiary amines to the formation of bicarbonate in those aqueous tertiary amines solution, it can be concluded that 1) the aqueous 3DMA1P solution produced more bicarbonate compared to DMMEA for its nearer distance of OH to N; 2) the less hydroxyalkyl and one more methyl in amine molecular structure connected to N in MDEA compared to TEA led to more bicarbonate generation; 3) a smaller alkyl connected to N in DMMEA molecular structure compare to DEEA resulted in more bicarbonate was generated in aqueous DMMEA solution; and 4) one more methyl branch existed in 1DMA2P and 1DEA2P molecular structures compared to 3DMA1P and DEEA, respectively, leading to less bicarbonate generation.%利用 13C NMR技术对CO2捕获叔胺溶剂进行了碳元素的定量研究,主要考察了对胺溶剂解吸热影响较大的3HCO?的生成规律.重点对叔胺分子结构中羟基官能团( OH)、羟烷基数目、烷基支链及氮原子(N)所连接烷

  13. [Mediation in health].

    Science.gov (United States)

    Decastello, Alice

    2008-02-10

    The author presents mediation as an alternative dispute resolution method. Mediation is a process where the parties are ready to settle their dispute out of court, by way of negotiation and with the involvement of an independent third person as mediator. In the mediation process the mediator shall not decide the dispute, nor examine the default or give legal advice or express his/her opinion - the mediator's duty is to help the parties bring their positions closer and come to a settlement agreement within a short time (120 days). The author gives a summary of the applications of the Hungarian Act on Mediation in Public Health and draws conclusions from the practical experience since entry into force of the legislation and illustrates the advantages of mediation over the court procedure (which may drag on for years). The primary advantages of mediation are that both the mediators and the parties are bound by the obligation of secrecy, the procedure is cheaper than the court proceedings, and the parties can "save their faces" because in mediation the winner-winner formula asserts itself - against lawsuits where the winner-loser positions are confronted. The author also analyses the specific data and information available so far. As for the future, the legislation needs to be amended at several points. It is particularly expedient to regulate the legal relationship between the insurance companies and the health service providers because the liability insurance may not cover the damages the courts adjudicate. And so some of the service providers may go bankrupt as the difference in excess of the upper limit of coverage - it might as well be up to HUF 5 million per case - shall be paid from own budget, to the charge of the upkeep costs. It is also required to review and amend the regulations on expert activities, just as it is inevitable to make data supply compulsory - otherwise it will be impossible to monitor the number of mediation procedures in health. At present

  14. General resonance mediation

    Energy Technology Data Exchange (ETDEWEB)

    McGarrie, Moritz

    2012-07-15

    We extend the framework of general gauge mediation to cases where the mediating fields have a nontrivial spectral function, as might arise from strong dynamics. We demonstrate through examples that this setup describes a broad class of possible models of gauge mediated supersymmetry breaking. A main emphasis is to give general formulas for cross sections for {sigma}(visible {yields} hidden) in these resonance models. We will also give formulas for soft masses, A-terms and demonstrate the framework with a holographic setup.

  15. Residue levels and efficacy of fludioxonil and thiabendazole in controlling postharvest green mold decay in citrus fruit when applied in combination with sodium bicarbonate.

    Science.gov (United States)

    D'Aquino, Salvatore; Palma, Amedeo; Angioni, Alberto; Schirra, Mario

    2013-01-16

    The curative and protective activity of sodium bicarbonate (SBC) at 1% alone or in combination with fludioxonil (FLU), thiabendazole (TBZ), or FLU and TBZ together, between 50 and 600 mg/L, was evaluated on fruit of different citrus species and cultivars. Fruits were either artificially inoculated with a resistant (TBZ-r) or sensitive (TBZ-s) strain of Penicillium digitatum or not inoculated and incubated at 20 °C and 90% relative humidity (RH) for 7 days (incubated fruit) or stored at 1.5 °C for 21 days plus 7 days of simulated marketing conditions at 20 °C and 60% RH. The effectiveness of these treatments was related with treatment-induced changes of epicuticular wax morphology, the mode of distribution of SBC, TBZ, and FLU on the fruit surface, and FLU and TBZ fruit residue levels. SBC alone showed a weak activity against both strains of P. digitatum. Both TBZ and FLU were very effective at all rates used, and their activity markedly increased when combined together or with SBC, even at concentrations of 50-150 mg/L. Fruit treated with SBC either alone or in combination with TBZ and/or FLU increased weight loss, although no treatment damage was detected. Residue levels of TBZ generally increased when TBZ was combined with FLU and/or SBC, whereas those of FLU slightly increased only in treatment where FLU was combined with TBZ and SBC. Initial residues of TBZ and FLU when applied at 600 mg/L were around 2 and 1 mg/kg, respectively, several times below the lowest MRLs set by most important citrus-producing countries. In treatments with SBC or SBC plus TBZ or FLU, SEM observation of the fruit surface showed a smoothing of cuticular wax platelets' surface, whereas ESEM micrographs showed irregular spots of salt deposits of roundish to irregular shape. The apparently uneven distribution of SBC or SBC plus TBZ or FLU or SBC plus TBZ and FLU on fruit might in part reduce the potential beneficial effects of SBC or of fungicide-SBC mixtures.

  16. Technology-Use Mediation

    DEFF Research Database (Denmark)

    Bansler, Jørgen P.; Havn, Erling C.

    2004-01-01

    Implementation of new computer-mediated communication (CMC) systems in organizations is a complex socio-technical endeavour, involving the mutual adaptation of technology and organization over time. Drawing on the analytic concept of sensemaking, this paper provides a theoretical perspective...... that deepens our understanding of how organizations appropriate new electronic communication media. The paper analyzes how a group of mediators in a large, multinational company adapted a new web-based CMC technology (a virtual workspace) to the local organizational context (and vice versa) by modifying...... features of the technology, providing ongoing support for users, and promoting appropriate conventions of use. We found that these mediators exerted considerable influence on how the technology was established and used in the organization. The mediators were not neutral facilitators of a well...

  17. Natural generalized mirage mediation

    CERN Document Server

    Baer, Howard; Serce, Hasan; Tata, Xerxes

    2016-01-01

    In the supersymmetric scenario known as mirage mediation (MM), the soft SUSY breaking terms receive comparable anomaly-mediation and moduli-mediation contributions leading to the phenomenon of mirage unification. The simplest MM SUSY breaking models which are consistent with the measured Higgs mass and sparticle mass constraints are strongly disfavoured by fine-tuning considerations. However, while MM makes robust predictions for gaugino masses, the scalar sector is quite sensitive to specific mechanisms for moduli stabilization and potential uplifting. We suggest here a broader setup of generalized mirage mediation (GMM), where heretofore discrete parameters are allowed as continuous to better parametrize these other schemes. We find that natural SUSY spectra consistent with both the measured value of m(h). as well as LHC lower bounds on superpartner masses are then possible. We explicitly show that models generated from natural GMM may be beyond the reach of even high-luminosity LHC searches. In such a case...

  18. DREDed Anomaly Mediation

    CERN Document Server

    Boyda, E; Pierce, A T; Boyda, Ed; Murayama, Hitoshi; Pierce, Aaron

    2002-01-01

    We offer a guide to dimensional reduction (DRED) in theories with anomaly mediated supersymmetry breaking. Evanescent operators proportional to epsilon arise in the bare Lagrangian when it is reduced from d=4 to d= (4-2 epsilon) dimensions. In the course of a detailed diagrammatic calculation, we show that inclusion of these operators is crucial. The evanescent operators conspire to drive the supersymmetry-breaking parameters along anomaly-mediation trajectories across heavy particle thresholds, guaranteeing the ultraviolet insensitivity.

  19. 关节镜下射频气化联合碳酸氢钠灌洗治疗膝痛风性关节炎%The Treatment of Knee Gouty Arthritis with Radio Frequency and Sodium Bicarbonate by Arthroscope

    Institute of Scientific and Technical Information of China (English)

    臧学慧; 高立华; 孙辉; 苗贵强

    2014-01-01

    目的:探讨关节镜下射频气化联合酸氢钠灌洗治疗膝痛风性关节炎的疗效。方法对56例痛风性关节炎患者,术前碳酸氢钠灌洗,利用关节镜下射频气化清理膝关节痛风结石。结果56例患者膝关节疼痛均消失,随访时间16~38(24±4)个月,无复发。根据Lysholm膝关节评分方法,术前评分平均43.6分;术后终末复查评分平均89.8分,两者相比,差异有显著性(<0.05)。结论关节镜下利用射频气化联合碳酸氢钠灌洗清除关节内痛风结晶,具有效率高、清除完全,是一种见效快、创伤小、效果确切的治疗方法。%Objective To explore the effect of radio frequency and sodium bicarbonate by arthroscope in treatment of knee gouty arthritis .Methods 56 patients with knee gouty arthritis were treated by sodium bicarbonate preoperatively and then gouty stone was cleared out with radio frequency and sodium bicarbonate by arthroscope.Results Pain in 56 patients was significantly alleviated postoperatively and no case recurred after fol owing up 16~38 (24±4)months . Lysholm score improved from 43.6 preoperatively to 89.8 postoperatively and the dif erence was statistical y significant ( <0.05).Conclusion That the treatment of knee gouty arthritis with radio frequency and sodium bicarbonate by arthroscope is rapid,micro-traumatic and effective for high ef iciency and completely clearing up.

  20. Caracterização por XPS de filmes passivos formados sobre aços de baixa liga em meio de bicarbonato XPS characterization of passive films formed on mild steels in bicarbonate medium

    Directory of Open Access Journals (Sweden)

    Valéria Almeida Alves

    2005-03-01

    Full Text Available Passive films formed in bicarbonate solutions on carbon steel, chromium steel and high speed steel have been characterized by XPS. The passive films formed on chromium and high speed steels showed superior protective properties than those formed on carbon steel. It was confirmed by XPS that the steel composition influences the passive film composition. Chromium oxide and hydroxide, as well as molybdenum and tungsten oxides and hydroxides are present in the passive film of chromium steel and high speed steel, respectively, besides iron oxide and hydroxide. The more complex composition of the oxide film on high speed steel explains its electrochemical behaviour and highest corrosion resistance.

  1. Polarized Solution Treatment and Sodium Bicarbonate on Hyperkalemia in Rabbits%极化液及纠正酸中毒对家兔高钾血症的治疗

    Institute of Scientific and Technical Information of China (English)

    杨黎黎; 金会艳; 余志诚; 李树清

    2011-01-01

    目的 探究一种稳定的高钾血症造模方法比较,极化液治疗及NaHCO3治疗对家兔实验性高钾血症的疗效并探讨其可能机制.方法 将30例家兔随机平均分成3组,运用“深静脉滴注法”造模成功后,分别进行生理盐水治疗,极化液治疗和碳酸氢钠治疗.结果 30例家兔通过颈外静脉滴注3%的氯化钾后均出现了典型的心电图变化,并且血清钾显著升高(P<0.01);分组治疗后,静脉滴注极化液和4%碳酸氢钠均可使心电图基本恢复正常血钾浓度明显下降(P<0.05).结论 深静脉滴注法是一种稳定可靠,易于操作的高钾血症模型复制方法,极化液和碳酸氢钠对高钾血症有抢救治疗作用.%Objective To investigate a steady way which named "intravenously guttae" of preparation of hyperkalemia in rabbit, and compare two different treatment methods polarized solution treatment and sodium bicarbonate treatment. Methods 30 rabbits were randomly divided into 3 groups: Saline group, polarized solution (glucose-insulin) group and sodium bicarbonate group (n = 10 in each group). All rabbits were injected with 3% KC1 and were treated with different ways. Results Typical ECG changes were found, and serum levels of [K+]were increased (P <0.05) in all 30 rabbits in three groups after injection of 3% KCL. After treatment, compared with Saline group, serum levels of [k+] were decreased significantly (P < 0.05) and ECG recovered to normal in glucose-insulin group and sodium bicarbonate group. Conclusion "Intravenously guttae is a simple and steady way of preparation of hyperkalemia model. Glucose-insulin and sodium bicarbonate are effective methods for the treatment of hyperkalemia.

  2. Metadata based mediator generation

    Energy Technology Data Exchange (ETDEWEB)

    Critchlow, T

    1998-03-01

    Mediators are a critical component of any data warehouse, particularly one utilizing partially materialized views; they transform data from its source format to the warehouse representation while resolving semantic and syntactic conflicts. The close relationship between mediators and databases, requires a mediator to be updated whenever an associated schema is modified. This maintenance may be a significant undertaking if a warehouse integrates several dynamic data sources. However, failure to quickly perform these updates significantly reduces the reliability of the warehouse because queries do not have access to the m current data. This may result in incorrect or misleading responses, and reduce user confidence in the warehouse. This paper describes a metadata framework, and associated software designed to automate a significant portion of the mediator generation task and thereby reduce the effort involved in adapting the schema changes. By allowing the DBA to concentrate on identifying the modifications at a high level, instead of reprogramming the mediator, turnaround time is reduced and warehouse reliability is improved.

  3. Study on the Dissolution of Omeprazole Sodium Bicarbonate Magnesium Hydroxyl Tablets by HPLC%HPLC法测定奥美拉唑碳酸氢钠氢氧化镁片溶出度

    Institute of Scientific and Technical Information of China (English)

    彭东明; 王福东; 卢茂芳; 刘艳飞

    2012-01-01

    目的:建立奥美拉唑碳酸氢钠氢氧化镁片溶出度测定方法.方法:以水为溶出介质,采用高效液相色谱法测定奥美拉唑碳酸氢钠氢氧化镁片的溶出度.结果:奥美拉唑线性方程为A =5.45×105C -7.58×104 (r =0.999 9)线性范围:4.0~40.0μg·ml-1.平均回收率为99.86%;RSD为0.42%.结论:本法可用于奥美拉唑碳酸氢钠氢氧化镁片溶出度测定.%Objective; To establish a dissolution determination method for omeprazole sodium bicarbonate magnesium hydroxyl tablets. Method; The dissolution was determined by HPLC using water as the dissolution medium. Result; A good linear relationship was within the range of 4.0 ~40.0 jig Ml'' (r = 0.999 1, r = 0.999 8). The average recovery was 99. 86% ( RSD = 0.42% ). Conclusion; The method can be used in the dissolution determination of omeprazole sodium bicarbonate magnesium hydroxyl tablets.

  4. Scientific Opinion on the safety assessment of the active substances, sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulphate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, for use as active system in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-02-01

    Full Text Available This scientific opinion of EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, used in mixture which is packed into sachets for absorbing oxygen/carbon dioxide emitting from/into the headspace surrounding packed food. All substances of this formulation have been evaluated and approved for use as additives in plastic food contact materials or as food additives. No migration of calcium, iron and sodium ions was detected. No volatile organic compounds other than carbon dioxide were detected at the limit of detection of 0.5 μg/l. The CEF Panel concluded that the use of the substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water does not raise a safety concern when used in oxygen absorber/carbon dioxide emitter systems, in sachets that prevent the physical release of their contents into the food. The sachets are to be placed in the headspace of the packaging and as such may come into occasional contact with the food, e.g. during handling. The sachet should not come into direct contact with liquid foods or foods that have and external aqueous liquid phase on the surface (liquid or exudates.

  5. Fashion, Mediations & Method Assemblages

    DEFF Research Database (Denmark)

    Sommerlund, Julie; Jespersen, Astrid Pernille

    of handling multiple, fluid realities with multiple, fluid methods. Empirically, the paper works with mediation in fashion - that is efforts the active shaping of relations between producer and consumer through communication, marketing and PR. Fashion mediation is by no means simple, but organise complex...... Modern. New York, Harvester-Wheatsheaf. Law, J. (2004). After Method - mess in social science research. London and New York, Routledge......., it is an important ambition of this paper to go into a methodological discussion of how "that which effectively happens" can be approached. To this end, the paper will combine Hennion's term of the "mediator" with John Laws methodological term of "method assemblages". Method assemblages is a suggested as a way...

  6. The Strategic Mediator

    DEFF Research Database (Denmark)

    Rossignoli, Cecilia; Carugati, Andrea; Mola, Lapo

    2009-01-01

    The last 10 years have witnessed the emergence of electronic marketplaces as players that leverage new technologies to facilitate B2B internet-mediated collaborative business. Nowadays these players are augmenting their services from simple intermediation to include new inter-organizational relat......The last 10 years have witnessed the emergence of electronic marketplaces as players that leverage new technologies to facilitate B2B internet-mediated collaborative business. Nowadays these players are augmenting their services from simple intermediation to include new inter......-marketplace assumes the paradoxical role of strategic mediator: an agent who upholds and heightens the fences of the transactions instead of leveling them. The results have implication in shaping how we see the role of technology as strategic or commoditized....

  7. Models as Mediators

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    from laboratory studies, (Latour 1979; Lynch 1985; Sommerlund 2004 (2007); Sommerlund 2006) and is complemented by the attention paid to the "mediator" by Hennion (1989; 1997; 2005). The empirical focus will be on a central - but overlooked - actor of branding and advertising; the model. The model has...... solely been theorized within cultural studies (Craik 1994) as feminine spectacle, but has been neglected as mediator and actor. This paper will argue that models are co-producers of brands, and vice versa. Empirically, the paper will present interviews with models, model-scouts, agents, and advertisers...

  8. Mediated intimacy in families

    DEFF Research Database (Denmark)

    Stougaard, Malthe Kirkhoff

    2006-01-01

    Mediating intimacy between children and their parents is still limited investigated and at the same time, we find that, emerging technologies are about to change and affect the way we interact with each other. In this paper, we report from an empirical study where we investigated the social...... with other types of intimate relations such as strong-tie intimacy (couples cohabiting). However, we also identified several issues of intimacy unique to the special relation between children and their parents. These unique acts of intimacy propose challenges when designing technologies for mediated intimacy...

  9. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to carbonate and bicarbonate salts of sodium and potassium and maintenance of normal bone (ID 331, 1402) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health...... claims in relation to carbonate and bicarbonate salts of sodium and potassium and maintenance of normal bone. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member...... States or directly from stakeholders. The food constituents that are the subject of the health claim are carbonate and bicarbonate salts of sodium and potassium. The Panel considers that carbonate and bicarbonate salts of sodium and potassium are sufficiently characterised. The claimed effects are “acid...

  10. Teachers as mediators

    DEFF Research Database (Denmark)

    Dorf, Hans; Kelly, Peter; Hohmann, Ulrike

    2012-01-01

    Within the context of lower secondary English teaching in South West England, this study identifies in broad terms the competing goals between which English teachers mediate and the explicit and hidden tensions that result. To understand the interactions of competing goals, teachers’ goal...

  11. Mediatization and Government Communication

    DEFF Research Database (Denmark)

    Laursen, Bo; Valentini, Chiara

    2015-01-01

    in the light of mediatization and government communication theories. Without one pan-European public sphere, the European Parliament, like the other European Union (EU) institutions, competes with national actors for the news media’s attention in the EU’s twenty-eight national public spheres, where EU affairs...

  12. Expanding mediation theory

    NARCIS (Netherlands)

    Verbeek, P.P.C.C.

    2012-01-01

    In his article In Between Us, Yoni van den Eede expands existing theories of mediation into the realm of the social and the political, focusing on the notions of opacity and transparency. His approach is rich and promising, but two pitfalls should be avoided. First, his concept of ‘in-between’ runs

  13. Mediation and Automatization.

    Science.gov (United States)

    Hutchins, Edwin

    This paper discusses the relationship between the mediation of task performance by some structure that is not inherent in the task domain itself and the phenomenon of automatization, in which skilled performance becomes effortless or phenomenologically "automatic" after extensive practice. The use of a common simple explicit mediating…

  14. Thermally favourable gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Dalianis, Ioannis, E-mail: Ioannis.Dalianis@fuw.edu.p [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Hoza 69, Warsaw (Poland); Lalak, Zygmunt, E-mail: Zygmunt.Lalak@fuw.edu.p [Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Hoza 69, Warsaw (Poland)

    2011-03-14

    We discuss the thermal evolution of the spurion and messenger fields of ordinary gauge mediation models taking into account the Standard Model degrees of freedom. It is shown that for thermalized messengers the metastable susy breaking vacuum becomes thermally selected provided that the susy breaking sector is sufficiently weakly coupled to messengers or to any other observable field.

  15. Natural generalized mirage mediation

    Science.gov (United States)

    Baer, Howard; Barger, Vernon; Serce, Hasan; Tata, Xerxes

    2016-12-01

    In the supersymmetric scenario known as mirage mediation (MM), the soft supersymmetry (SUSY) breaking terms receive comparable anomaly-mediation and moduli-mediation contributions leading to the phenomenon of mirage unification. The simplest MM SUSY breaking models which are consistent with the measured Higgs mass and sparticle mass constraints are strongly disfavored by fine-tuning considerations. However, while MM makes robust predictions for gaugino masses, the scalar sector is quite sensitive to specific mechanisms for moduli stabilization and potential uplifting. We suggest here a broader setup of generalized mirage mediation (GMM), where heretofore discrete parameters are allowed as continuous to better parametrize these other schemes. We find that natural SUSY spectra consistent with both the measured value of mh as well as LHC lower bounds on superpartner masses are then possible. We explicitly show that models generated from natural GMM may be beyond the reach of even high-luminosity LHC searches. In such a case, the proposed International Linear e+e- Collider will be required for natural SUSY discovery via higgsino pair production reactions. We also outline prospects for detection of higgsino-like WIMPs from natural GMM.

  16. The Regulatory Role of Rolipram on Inflammatory Mediators and Cholinergic/Adrenergic Stimulation-Induced Signals in Isolated Primary Mouse Submandibular Gland Cells

    Directory of Open Access Journals (Sweden)

    Dong Un Lee

    2016-01-01

    Full Text Available Exposure to bacterial lipopolysaccharides (LPS induces inflammatory signals in salivary glands. We investigated the regulatory role of phosphodiesterase 4 (PDE4 inhibitor rolipram on inflammatory mediators and cholinergic/adrenergic stimulation-induced intracellular Ca2+ signaling in salivary acinar and ductal cells. Submandibular gland (SMG expressed PDE4A through 4D mRNA and PDE4 was localized in the luminal membrane of SMG. LPS induced Ca2+ signaling and ROS production in SMG. Treatment with rolipram blocked LPS-induced Ca2+ increase and ROS production. The application of histamine evoked Ca2+ signals and ROS production, which were attenuated by rolipram in SMG cells. Moreover, LPS-induced NLRP3 inflammasome and cleaved caspase-1 were inhibited by rolipram. The inhibitory role of rolipram in ROS-induced Ca2+ signaling was mainly observed in acinar cells and not in ductal cells. Rolipram also protected SMG acinar but not ductal cells from LPS-induced cell membrane damage. In the case of cholinergic/adrenergic stimulation, carbachol/isoproterenol-induced Ca2+ signals were upregulated by the treatment of rolipram in SMG. In the case of cAMP-dependent ductal bicarbonate secretion by rolipram, no effect was observed on the modulation of ductal chloride/bicarbonate exchange activity. Rolipram could suppress the inflammatory signals and could be a potential therapeutic strategy against LPS-induced inflammation to protect the salivary gland cells.

  17. The Regulatory Role of Rolipram on Inflammatory Mediators and Cholinergic/Adrenergic Stimulation-Induced Signals in Isolated Primary Mouse Submandibular Gland Cells

    Science.gov (United States)

    Lee, Dong Un; Shin, Dong Min; Hong, Jeong Hee

    2016-01-01

    Exposure to bacterial lipopolysaccharides (LPS) induces inflammatory signals in salivary glands. We investigated the regulatory role of phosphodiesterase 4 (PDE4) inhibitor rolipram on inflammatory mediators and cholinergic/adrenergic stimulation-induced intracellular Ca2+ signaling in salivary acinar and ductal cells. Submandibular gland (SMG) expressed PDE4A through 4D mRNA and PDE4 was localized in the luminal membrane of SMG. LPS induced Ca2+ signaling and ROS production in SMG. Treatment with rolipram blocked LPS-induced Ca2+ increase and ROS production. The application of histamine evoked Ca2+ signals and ROS production, which were attenuated by rolipram in SMG cells. Moreover, LPS-induced NLRP3 inflammasome and cleaved caspase-1 were inhibited by rolipram. The inhibitory role of rolipram in ROS-induced Ca2+ signaling was mainly observed in acinar cells and not in ductal cells. Rolipram also protected SMG acinar but not ductal cells from LPS-induced cell membrane damage. In the case of cholinergic/adrenergic stimulation, carbachol/isoproterenol-induced Ca2+ signals were upregulated by the treatment of rolipram in SMG. In the case of cAMP-dependent ductal bicarbonate secretion by rolipram, no effect was observed on the modulation of ductal chloride/bicarbonate exchange activity. Rolipram could suppress the inflammatory signals and could be a potential therapeutic strategy against LPS-induced inflammation to protect the salivary gland cells. PMID:27143817

  18. Computational modeling reveals dendritic origins of GABA(A-mediated excitation in CA1 pyramidal neurons.

    Directory of Open Access Journals (Sweden)

    Naomi Lewin

    Full Text Available GABA is the key inhibitory neurotransmitter in the adult central nervous system, but in some circumstances can lead to a paradoxical excitation that has been causally implicated in diverse pathologies from endocrine stress responses to diseases of excitability including neuropathic pain and temporal lobe epilepsy. We undertook a computational modeling approach to determine plausible ionic mechanisms of GABA(A-dependent excitation in isolated post-synaptic CA1 hippocampal neurons because it may constitute a trigger for pathological synchronous epileptiform discharge. In particular, the interplay intracellular chloride accumulation via the GABA(A receptor and extracellular potassium accumulation via the K/Cl co-transporter KCC2 in promoting GABA(A-mediated excitation is complex. Experimentally it is difficult to determine the ionic mechanisms of depolarizing current since potassium transients are challenging to isolate pharmacologically and much GABA signaling occurs in small, difficult to measure, dendritic compartments. To address this problem and determine plausible ionic mechanisms of GABA(A-mediated excitation, we built a detailed biophysically realistic model of the CA1 pyramidal neuron that includes processes critical for ion homeostasis. Our results suggest that in dendritic compartments, but not in the somatic compartments, chloride buildup is sufficient to cause dramatic depolarization of the GABA(A reversal potential and dominating bicarbonate currents that provide a substantial current source to drive whole-cell depolarization. The model simulations predict that extracellular K(+ transients can augment GABA(A-mediated excitation, but not cause it. Our model also suggests the potential for GABA(A-mediated excitation to promote network synchrony depending on interneuron synapse location - excitatory positive-feedback can occur when interneurons synapse onto distal dendritic compartments, while interneurons projecting to the perisomatic

  19. Expression and/or activity of the SVCT2 ascorbate transporter may be decreased in many aggressive cancers, suggesting potential utility for sodium bicarbonate and dehydroascorbic acid in cancer therapy.

    Science.gov (United States)

    McCarty, Mark F

    2013-10-01

    rendering them less aggressive. Indeed, several published studies have concluded that parenteral DHA--sometimes in quite modest doses--can retard the growth of transplanted tumors in rodents. As an alternative or adjunctive strategy, oral administration of sodium bicarbonate, by normalizing the extracellular pH of tumors, has the potential to boost the activity of SCTV2 in tumor cells, thereby promoting increased ascorbate uptake. Indeed, the utility of oral sodium bicarbonate for suppressing metastasis formation in nude mice xenografted with a human breast cancer has been reported. Hence, oral sodium bicarbonate and intravenous DHA may have the potential to blunt the aggressiveness of certain cancers in which suboptimal intracellular ascorbate levels contribute to elevated HIF-1 activity.

  20. Efficacy of sodium bicarbonate and fluconazole in the treatment of fungal otitis externa%碳酸氢钠联合氟康唑注射液治疗真菌性外耳道炎35例

    Institute of Scientific and Technical Information of China (English)

    沈莉

    2016-01-01

    Objective To explore the clinical efficacy of sodium bicarbonate combined with fluconazole in the treatment of fungal otitis externa.Methods Using random parallel control method,105 patients with fungal otitis externa were divided into three groups:the treatment group (ear bath with sodium bicarbonate plus fluconazole injection);control group 1 (ear bath with fluconazole injection);control group 2 (ear bath with 2%salicylic acid alcohol),with 35 cases in each group.The treatment lasted for 10 days.The patients were followed up for one year to observe the curative effect.Results The total effective rate of the 3 groups were 91.43%,85.71%,and 77.14%.The efficacy of the treatment group was better than that of the control groups (P<0.05).Conclusion Sodium bicarbonate combined with fluconazole is better than 2% salicylic acid alcohol or fluconazole alone in the treatment of fungal otitis externa.%目的:探讨碳酸氢钠联合氟康唑注射液治疗真菌性外耳道炎的疗效。方法使用随机平行对照方法,将真菌性外耳道炎患者105例,分为治疗组(碳酸氢钠联合氟康唑注射液耳浴);对照一组(氟康唑注射液耳浴);对照二组(2%水杨酸酒精耳浴),每组35例,连用10 d为一疗程,随访一年观察疗效。结果3个组的总有效率分别为91.43%、85.71%、77.14%,治疗组疗效优于2个对照组(P<0.05)。结论碳酸氢钠联合氟康唑注射液治疗真菌性外耳道炎的疗效优于单独采用氟康唑注射液或2%水杨酸酒精。

  1. Influence of bicarbonate on organic acid of glutamic acid-producing bacteria under oxygen deprivation%碳酸盐对谷氨酸产生菌在缺氧条件下产有机酸的影响

    Institute of Scientific and Technical Information of China (English)

    于芳; 郑璞; 倪晔; 董晋军; 王兴林; 孙志浩

    2011-01-01

    考察谷氛酸产生菌在缺氧条件下积累L-乳酸和琥珀酸的情况.结果表明:在缺氧条件下,嗜乙酰乙酸棒杆菌(Corynebacterium acetoacidophilum)ATCC 13870积累有机酸的浓度随菌体密度的增大而增加,其中琥珀酸和乳酸积累的最适pH分别为7.5和8.0,最高质量浓度分别为22.5和60g/L.碳酸盐是影响产酸与有机酸分布的主要因素.比较ATCC 13870在NaHC03浓度为40和400mmol/L时的代谢通量,发现后者合成琥珀酸的代谢通量比前者提高了214.1%,合成乳酸的代谢通量降低了61.8%,说明PEP节点处的代谢通量分配明显受NaHCO3浓度的影响,而PYR节点受环境因素的影响不明显.%Succinic acid and lactic acid accumulation by L-glutamic acid-producing bacteria under oxygen deprivation were investigated. Results showed that Corynebacterium acetoacidophilum ATCC 13870 could accumulate notable concentration of organic acid, in which the yield of organic acid increased with its cell density. The optimal pH values for succinic acid and lactic acid generation by C. Acetoacidophilum ATCC 13870 were 7.5 and 8.0, respectively, at which the concentrations of succinic acid and lactic acid reached to 22. 5 and 60. 0 g/L, correspondingly. Bicarbonate was the key factor influencing organic acid synthesis more than glucose. The metabolic flux to the succinic acid synthesis pathway increased by 214. 1% , while the flux to the lactic acid synthesis pathway decreased by 61. 8% with increasing sodium bicarbonate concentration from 40 mmol/L to 400 mmol/L. This indicated that PEP node was evidently influenced by sodium bicarbonate concentration but the influence of PYR node was less.

  2. Nanofluids mediating surface forces.

    Science.gov (United States)

    Pilkington, Georgia A; Briscoe, Wuge H

    2012-11-01

    Fluids containing nanostructures, known as nanofluids, are increasingly found in a wide array of applications due to their unique physical properties as compared with their base fluids and larger colloidal suspensions. With several tuneable parameters such as the size, shape and surface chemistry of nanostructures, as well as numerous base fluids available, nanofluids also offer a new paradigm for mediating surface forces. Other properties such as local surface plasmon resonance and size dependent magnetism of nanostructures also present novel mechanisms for imparting tuneable surface interactions. However, our fundamental understanding, experimentally and theoretically, of how these parameters might affect surface forces remains incomplete. Here we review recent results on equilibrium and dynamic surface forces between macroscopic surfaces in nanofluids, highlighting the overriding trends in the correlation between the physical parameters that characterise nanofluids and the surface forces they mediate. We also discuss the challenges that confront existing surface force knowledge as a result of this new paradigm.

  3. The mediatization of journalism

    Directory of Open Access Journals (Sweden)

    Aske Kammer

    2014-06-01

    Full Text Available Proposing an explanation of current macro-sociological changes and institutional transformations in journalism, this article argues that journalism is currently undergoing a process of mediatization. Drawing upon the international research literature as well as statements from interviews with news workers working on Danish news websites, the article examines four current trends in journalism that are closely connected to the rise of news on the web, namely the use of the affordances of news websites, radical commercialization, increased audience participation in news production, and the increased multi-skilling and simultaneous de-skilling of journalists. Taken together, these trends reflect a process through which journalism increasingly subsumes itself to the logic of the media, suggesting mediatization as an adequate explanatory framework. One implication of such a process is that journalism seems to be transforming from an occupational profession into an organizational one.

  4. [Healthcare mediation model for nerologists].

    Science.gov (United States)

    Ando, Tetsuo

    2011-11-01

    Mediation offers a process by which two parties work towards an agreement with the aid of a neutral third party. Physicians and nurses can apply healthcare mediation model to ordinary medical practice for preventing conflict. Communication using mediation skills improves patient-physician relationship, and prevents medical malpractice and conflict.

  5. Surface Mediated Photocatalysis.

    Science.gov (United States)

    1987-12-01

    Bipolar Photoelectrodes," M.A. Fox, Nouv. J. Chim. 1987, II, 129. 4. "Effect of Cosolvent Additives on Relative Rates of Photooxidation on...Semiconductor Surfaces," D.D. Sackett, M.A. Fox, J. Phys. Org. Chem, 19_8, in press. 5. "Selectivity in the Semiconductor-Mediated Photooxidation of Polyols ...surfaced properties of the heteropolytungstates were varied. The conceptual mechanistic picture involved in the heteropolyoxo induced photooxidations

  6. Endothelium-derived hyperpolarizing factor mediated relaxations in pig coronary arteries do not involve Gi/o proteins

    Institute of Scientific and Technical Information of China (English)

    Kwok Fu Jacobus NG; Susan Wai Sum LEUNG; Picky Ying Keung MAN; Paul M VANHOUTTE

    2008-01-01

    Aim: Endothelium-dependent relaxations to certain neurohumoral substances are mediated by pertussis toxin-sensitive Gi/o protein. Our experiments were designed to determine the role, if any, of pertussis toxin-sensitive G-proteins in relaxations attributed to endothelium-derived hyperpolarizing factor (EDHF). Methods: Pig coronary arterial rings with endothelia were suspended in organ chambers filled with Krebs-Ringer bicarbonate solution maintained at 37℃ and continuously aerated with 95%O2 and 5% CO2. Isometric tension was measured during contractions to prostaglandin F2, in the presence of indomethacin and Nω-nitro-L-arginine methyl ester (L-NAME). Results: Thrombin, the thrombin re-ceptor-activating peptide SFLLRN, bradykinin, substance P, and calcimycin pro-duced dose-dependent relaxations. These relaxations were not inhibited by prior incubation with pertussis toxin, but were abolished upon the addition of charyb-dotoxin plus apamin. Relaxations to the α2-adrenergic agonist UK14304 and those to serotonin were abolished in the presence of indomethacin and L-NAME. Conclusion: Unlike nitric oxide-mediated relaxations, EDHF-mediated relax-ations of pig coronary arteries do not involve pertussis toxin-sensitive pathways and are Gi/o protein independent.

  7. Extração de ferro de esmectita brasileira com emprego do método ditionito-citrato-bicarbonato Iron extraction from Brazilian smectite by dithionite-citrate-bicarbonate method

    Directory of Open Access Journals (Sweden)

    Sidnei Quezada M. Leite

    2000-06-01

    Full Text Available A natural clay from Campina Grande region (Paraíba, Brazil, with 8.57% of Fe2O3, was used to study the most appropriate condition to carry out the iron extraction, without altering the clay structure in a significant way. Samples were treated with the Dithionite-Citrate-Bicarbonate method (DCB for 30 and 120 minutes (pH=9.1, and also with citric acid (pH=1.8; time=15min, at 75°C. Conductivity measurements, X-ray fluorescence, X-ray diffraction, energy-dispersive spectrometry, electron-diffraction with transmission electron microscopy and textural evaluation by nitrogen adsorption were done. The treatment in a basic medium was more selective for iron removal than in acid condition. The time of 30 minutes, with 1.6 g Na2S2O4/10 g clay, was the best condition for the iron extraction.

  8. Complex application of sodium bicarbonate hydrogen peroxide and nystatin in denture stomatitis therapy%碳酸氢钠、双氧水、制霉菌素联合治疗义齿性口炎的探讨

    Institute of Scientific and Technical Information of China (English)

    宋雅能

    2012-01-01

      Objective To survey the complex application of sodium bicarbonate hydrogen peroxide and nystatin in denture stomatitis therapy and provide a feasible method in denture stomatitis therapy. Methods 56 cases of denture stomatitis patients were separated into two groups randomly, group control 28 cases, gargle with sodium bicarbonate solution three times a day, take off denture before sleep, dip in clean water; experimental group 28 cases, gargle with sodium bicarbonate solution three times a day, smear nystatin on denture surface, put on dentures, take off denture before sleep and dip it in hydrogen peroxide, compare therapy effect after 15 and 30 days. Results After 15 days therapy effect was group control 35.71%, experimental group 71.43%(χ2=7.18, P<0.01), after 30 days of therapy group control 57.14%, experimental group 89.29%, effect rate of experimental group was significantly higher than group control(χ2=7.38, P<0.01). Conclusion Complex therapy with sodium bicarbonate hydrogen peroxide and nystatin may cure denture stomatitis effectively.%  目的探讨碳酸氢钠、双氧水、制霉菌素联合治疗义齿性口炎的疗效,为义齿性口炎患者提供一种简便易行的治疗方法.方法将56例义齿性口炎患者随机分成两组,对照组28人采用传统方法,以碳酸氢钠漱口,3次/d,睡前摘掉义齿,置于清水中浸泡;实验组28人以碳酸氢钠漱口,3次/d,义齿上涂抹制霉菌素,戴上义齿,睡前摘掉义齿,浸于双氧水中.于15d、30d观察治疗效果.结果治疗15d,实验组治愈率71.43%,高于对照组的35.71%(χ2=7.18,P<0.01),治疗30d,实验组治愈率89.29%,高于对照组的57.14%(χ2=7.38,P<0.01).结论使用碳酸氢钠、双氧水、制霉菌素联合治疗义齿性口炎,简单易行,较传统方法能明显提高治愈率.

  9. Clinical application of natrium bicarbonate solution as a humidification agent in artificial airway of mechanically ventilated patients%碳酸氢钠作为机械通气患者气道湿化剂的临床研究

    Institute of Scientific and Technical Information of China (English)

    王晓慧; 郑俊波; 王希臻; 赵士宏; 高春兴; 王孝艳; 于凯江

    2011-01-01

    Objective To explore the effects of sodium bicarbonate solution as a humidification agent in artificial airway so as to provide references of artificial airway nursing. Methods A total of 200 patients with artificial airway were enrolled. 2. 5% natrium bicarbonicum and 0. 9% saline liquid were used as airway instillation solution before suction respectively in every patient. Blood pressure,heart rate,blood gas analysis and the condition of sputum were collected before and after suction. Results There were statistically significant differences in characteristics of sputum, before and after instillation of two kinds of airway humidiflcation fluid in airway. BE and HCO3- had statistically significance before and after instillation of sodium bicarbonate in airway (P <0.05),but the blood pressure and heart rate had no effect (P >0.05). Conclusion Application of sodium bicarbonate solution as a humidification agent in artificial airway can dilute sputum and is beneficial for sputum suction. At the same time, it has no effect on heart rate and blood pressure, but it can act on BE and HCO3 . So sodium bicarbonate solution should be cautious to use as humidifier in artificial airway management.%目的 探讨碳酸氢钠作为人工气道湿化液的效果,为人工气道护理提供依据.方法 采用自身前后对照,对200例人工气道应用机械通气患者,分别应用0.9%生理盐水和2.5%碳酸氢钠气道滴入吸痰,比较吸痰前后血压、心率、血气分析结果及痰液性状的变化.结果 气道滴入两种气道湿化液吸痰前后痰液性状差异有统计学意义(P<0.05);气道滴人碳酸氢钠后剩余碱值及碳酸氢根值差异有统计学意义(P<0.05),而对血压、心率无影响(p>0.05).结论 应用碳酸氢钠气道滴入后可以稀释痰液利于痰液吸出,同时对患者的血压、心率无影响,但是能够影响剩余碱值及碳酸氢根值,因此临床上应谨慎使用碳酸氢钠作为人工气道湿化液.

  10. What carries a mediation process? Configural analysis of mediation.

    Science.gov (United States)

    von Eye, Alexander; Mun, Eun Young; Mair, Patrick

    2009-09-01

    Mediation is a process that links a predictor and a criterion via a mediator variable. Mediation can be full or partial. This well-established definition operates at the level of variables even if they are categorical. In this article, two new approaches to the analysis of mediation are proposed. Both of these approaches focus on the analysis of categorical variables. The first involves mediation analysis at the level of configurations instead of variables. Thus, mediation can be incorporated into the arsenal of methods of analysis for person-oriented research. Second, it is proposed that Configural Frequency Analysis (CFA) can be used for both exploration and confirmation of mediation relationships among categorical variables. The implications of using CFA are first that mediation hypotheses can be tested at the level of individual configurations instead of variables. Second, this approach leaves the door open for different types of mediation processes to exist within the same set. Using a data example, it is illustrated that aggregate-level analysis can overlook mediation processes that operate at the level of individual configurations.

  11. Hidratação com bicarbonato de sódio não previne a nefropatia de contraste: ensaio clínico multicêntrico Hydration with sodium bicarbonate does not prevent contrast nephropathy: a multicenter clinical trial

    Directory of Open Access Journals (Sweden)

    Vitor O. Gomes

    2012-12-01

    Full Text Available FUNDAMENTO: A exposição ao meio de contraste radiográfico pode causar comprometimento agudo da função renal. Há evidências limitadas e conflitantes de que a hidratação com bicarbonato de sódio previne a Nefropatia Induzida por Contraste (NIC em pacientes submetidos a cateterismo cardíaco. OBJETIVO: O presente estudo teve como objetivo determinar se o bicarbonato de sódio é superior à hidratação com soro fisiológico para evitar a nefropatia em pacientes de risco submetidos a cateterismo cardíaco. MÉTODOS: Trezentos e um pacientes submetidos a intervenção coronariana percutânea ou angiografia coronariana com creatinina sérica > 1,2 mg/dL ou Taxa de Filtração Glomerular (TFG BACKGROUND: Radiographic contrast media exposition can cause acute renal function impairment. There is limited and conflicting evidence that hydration with sodium bicarbonate prevents contrast-induced nephropathy (CIN in patients undergoing cardiac catheterization. OBJECTIVE: The present study was aimed at determining whether sodium bicarbonate is superior to hydration with saline to prevent nephropathy in patients at risk undergoing cardiac catheterization. METHODS: Three hundred and one patients undergoing coronary angiography or percutaneous coronary intervention with serum creatinine > 1.2mg/dL or glomerular filtration rate (GFR < 50ml/min were randomized to receive hydration with sodium bicarbonate starting 1 hour before the procedure and 6 hours after the procedure, or hydration with 0.9% saline. CIN was defined as an increase of 0.5mg/dL in creatinine in 48h RESULTS: Eighteen patients (5.9% developed contrast induced nephropathy: 9 patients in the bicarbonate group (6.1% and 9 patients in the saline group (6.0%, p = 0.97. The change in serum creatinine was similar in both groups, 0.01 ± 0.26 mg/dL in the bicarbonate group and 0.01 ± 0.35 mg/dL in the saline group, p = 0.9. No statistical difference was observed between the change in glomerular

  12. Hidratação com bicarbonato de sódio não previne a nefropatia de contraste: ensaio clínico multicêntrico Hydration with sodium bicarbonate does not prevent contrast nephropathy: a multicenter clinical trial

    Directory of Open Access Journals (Sweden)

    Vitor O. Gomes

    2012-01-01

    Full Text Available FUNDAMENTO: A exposição ao meio de contraste radiográfico pode causar comprometimento agudo da função renal. Há evidências limitadas e conflitantes de que a hidratação com bicarbonato de sódio previne a Nefropatia Induzida por Contraste (NIC em pacientes submetidos a cateterismo cardíaco. OBJETIVO: O presente estudo teve como objetivo determinar se o bicarbonato de sódio é superior à hidratação com soro fisiológico para evitar a nefropatia em pacientes de risco submetidos a cateterismo cardíaco. MÉTODOS: Trezentos e um pacientes submetidos a intervenção coronariana percutânea ou angiografia coronariana com creatinina sérica > 1,2 mg/dL ou Taxa de Filtração Glomerular (TFG BACKGROUND: Radiographic contrast media exposition can cause acute renal function impairment. There is limited and conflicting evidence that hydration with sodium bicarbonate prevents contrast-induced nephropathy (CIN in patients undergoing cardiac catheterization. OBJECTIVE: The present study was aimed at determining whether sodium bicarbonate is superior to hydration with saline to prevent nephropathy in patients at risk undergoing cardiac catheterization. METHODS: Three hundred and one patients undergoing coronary angiography or percutaneous coronary intervention with serum creatinine > 1.2mg/dL or glomerular filtration rate (GFR < 50ml/min were randomized to receive hydration with sodium bicarbonate starting 1 hour before the procedure and 6 hours after the procedure, or hydration with 0.9% saline. CIN was defined as an increase of 0.5mg/dL in creatinine in 48h RESULTS: Eighteen patients (5.9% developed contrast induced nephropathy: 9 patients in the bicarbonate group (6.1% and 9 patients in the saline group (6.0%, p = 0.97. The change in serum creatinine was similar in both groups, 0.01 ± 0.26 mg/dL in the bicarbonate group and 0.01 ± 0.35 mg/dL in the saline group, p = 0.9. No statistical difference was observed between the change in glomerular

  13. Inhibition of the Na/bicarbonate cotransporter NBCe1-A by diBAC oxonol dyes relative to niflumic acid and a stilbene.

    Science.gov (United States)

    Liu, Xiaofen; Williams, Jennifer B; Sumpter, Brandon R; Bevensee, Mark O

    2007-02-01

    Na/HCO(3) cotransporters (NBCs) are important regulators of intracellular pH (pH(i) in a variety of organ systems where acid-base status is critical for tissue function. To characterize the pharmacology of NBCs in more detail, we used the two-electrode voltage-clamp technique to examine the effect of previously identified inhibitors of anion exchanger 1 (AE1) on the activity of rat NBCe1-A expressed in Xenopus laevis oocytes. NBC-expressing oocytes voltage-clamped at -60 mV and exposed to a 5% CO(2)/33 mM HCO(3)(-) solution displayed NBC-mediated outward currents that were inhibited by either niflumic acid or one of the two bis-oxonol dyes diBA(3)C4 and diBA(5)C4. NBCe1-A was less sensitive to niflumic acid (apparent K(i) of 100 microM) than 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS, apparent K(i) of 36 microM) but more sensitive to the diBAC dyes (apparent K(i) of approximately 10 microM). Based on current-voltage relationships, the diBAC dyes inhibited HCO(3)(-) -induced NBCe1-mediated inward currents more so than outward currents. NBCe1 sensitivity to the dyes was (1) lower in the presence of 40 microM DIDS, (2) unaffected by changes in external HCO(3)(-) concentration and (3) only modestly higher at an external Na(+) concentration of 5, but not 15 or 33, mM. Therefore, the diBAC dyes compete with DIDS but not appreciably with Na(+) or HCO(3)(-) for binding. The mechanism of diBAC inhibition of NBCe1 appears similar to that previously reported for AE1.

  14. Urban Songlines as Mediator

    DEFF Research Database (Denmark)

    Corlin, Anne

    2016-01-01

    The aim of this paper is to present an investigation of the method The Urban Songlines Book and how it works as a mediator for mapping the experienced space. The method contains a combination of aerial maps, photographs, and interviews as a way to understand the respondent´s use, relations...... and experiences of their neighborhood and the city. Through a presentation of the origin of the method, a description of the conducted study, and an analysis of the process in relation to theories about participatory design, social design, ANT and architectural sociology, the paper reveals how this method...

  15. Sociocultural mediators of remembering

    DEFF Research Database (Denmark)

    Wagoner, Brady; Gillespie, Alex

    2014-01-01

    , questioning and deferring contribute to the transformation and conventionalization of the material. These diverse sociocultural mediators are integrated into a partially coherent recollection by participants self-reflecting, or as Bartlett termed it, turning around upon their schemas. We demonstrate...... that this self-reflection is both a social and a psychological process, occurring because participants are responding to their own utterances in the same way that they respond to the utterances of other people. These empirical findings are used to make a case for using discursive data to look not only...

  16. Mediatization and Government Communication

    DEFF Research Database (Denmark)

    Laursen, Bo; Valentini, Chiara

    2015-01-01

    in the light of mediatization and government communication theories. Without one pan-European public sphere, the European Parliament, like the other European Union (EU) institutions, competes with national actors for the news media’s attention in the EU’s twenty-eight national public spheres, where EU affairs......, and particularly into the thinking that guides the efforts of these European Parliament officials to increase European citizens’ awareness of, and support for, the European Parliament that is meant to voice the citizens’ concerns in political processes at the EU level....

  17. Computer Mediated Communication

    Science.gov (United States)

    Fano, Robert M.

    1984-08-01

    The use of computers in organizations is discussed in terms of its present and potential role in facilitating and mediating communication between people. This approach clarifies the impact that computers may have on the operation of organizations and on the individuals comprising them. Communication, which is essential to collaborative activities, must be properly controlled to protect individual and group privacy, which is equally essential. Our understanding of the human and organizational aspects of controlling communication and access to information presently lags behind our technical ability to implement the controls that may be needed.

  18. Holographic Gauge Mediation

    Energy Technology Data Exchange (ETDEWEB)

    Benini, Francesco; /Princeton U.; Dymarsky, Anatoly; /Stanford U., ITP; Franco, Sebastian; /Santa Barbara, KITP; Kachru, Shamit; Simic, Dusan; /Stanford U., ITP /SLAC; Verlinde, Herman; /Princeton, Inst. Advanced Study

    2009-06-19

    We discuss gravitational backgrounds where supersymmetry is broken at the end of a warped throat, and the SUSY-breaking is transmitted to the Standard Model via gauginos which live in (part of) the bulk of the throat geometry. We find that the leading effect arises from splittings of certain 'messenger mesons,' which are adjoint KK-modes of the D-branes supporting the Standard Model gauge group. This picture is a gravity dual of a strongly coupled field theory where SUSY is broken in a hidden sector and transmitted to the Standard Model via a relative of semi-direct gauge mediation.

  19. Surface-Mediated Photocatalysis

    Science.gov (United States)

    1992-02-04

    Photocatalysis 6. AUTHOR(S) DIMarye Anne Fox E -LECTE ’ / 7. PERFORMING ORGANIZATION NAME(S) AND AD ES). 8. PERFORMING ORGANIZATION REPORT NUMBER University of...Form 298 (Rev 2-89) Prescr d bv ANJ std Z39.1s 291-102 j Final Report on Surface-Mediated Photocatalysis "a,. . ARO Proposal No. 28298-CH u - Work from...Produced by Anodic Oxidation and by Photoelectrochemical Activation of TiO2 ," Marye Anne Fox and Karl L. Worthen, Chem. Mater. 1991, 3, 253. "Surface

  20. 45 CFR 16.18 - Mediation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Mediation. 16.18 Section 16.18 Public Welfare... BOARD § 16.18 Mediation. (a) In cases pending before the Board. If the Board decides that mediation... mediation techniques and will provide or assist in selecting a mediator. The mediator may take any...

  1. Mediation Revisited: The Interactive Organization of Mediation in Learning Environments

    OpenAIRE

    Pekarek Doehler, Simona

    2013-01-01

    This article is concerned with the social organization of mediation in learning environments. It seeks to further articulate the sociocultural notion of mediation in sociointeractional terms, combining insights from the sociocultural approach to cognition and the microinteractionist, especially ethnomethodological approach to social activities. A microanalysis of mediation in communicative 2nd-language classroom activities where the task at hand is the management of interaction itself is pres...

  2. Magnetically mediated thermoacoustic imaging

    Science.gov (United States)

    Feng, Xiaohua; Gao, Fei; Zheng, Yuanjin

    2014-03-01

    In this paper, alternating magnetic field is explored for inducing thermoacoustic effect on dielectric objects. Termed as magnetically mediated thermo-acoustic (MMTA) effect that provides a contrast in conductivity, this approach employs magnetic resonance for delivering energy to a desired location by applying a large transient current at radio frequency below 50MHz to a compact magnetically resonant coil. The alternating magnetic field induces large electric field inside conductive objects, which then undergoes joule heating and emanates acoustic signal thermo-elastically. The magnetic mediation approach with low radio frequency can potentially provide deeper penetration than microwave radiation due to the non-magnetic nature of human body and therefore extend thermoacoustic imaging to deep laid organs. Both incoherent time domain method that applies a pulsed radio frequency current and coherent frequency domain approach that employs a linear chirp signal to modulate the envelop of the current are discussed. Owing to the coherent processing nature, the latter approach is capable of achieving much better signal to noise ratio and therefore potential for portable imaging system. Phantom experiments are carried out to demonstrate the signal generation together with some preliminary imaging results. Ex-vivo tissue studies are also investigated.

  3. Mediating Trust in Terrorism Coverage

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    crisis. While the framework is presented in the context of television coverage of a terror-related crisis situation, it can equally be used in connection with all other forms of mediated trust. Key words: National crisis, risk communication, crisis management, television coverage, mediated trust.......Mass mediated risk communication can contribute to perceptions of threats and fear of “others” and/or to perceptions of trust in fellow citizens and society to overcome problems. This paper outlines a cross-disciplinary holistic framework for research in mediated trust building during an acute...

  4. When Memories are Mediated

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth; Bjerregaard, Mette

    2013-01-01

    and political contexts and media platforms take place and become contexts for audience reception. This paper explores two examples of narratives that construct memories of acts of mass violence: “Gzim Rewind” (Sweden, 2011, director Knutte Wester) about 1990’s Kosovo, and “The Act of Killing” (Denmark, 2012......Acts of mass violence, including murder on civilians, genocide, oppression and wars, can mobilize memories of the involved persons and following generations in a certain historical situation. Acts of mass violence can also create a sort of looking glass of culturally dominant memories...... that are mediated through stories: told and retold as oral stories through generations, as myths or sagas, or remediated as contemporary documentary film accounts or more fictional film accounts. In these processes of retelling acts of violence, transformations of meanings across time, cultural, social...

  5. Neutrino assisted gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Do; Mo, Doh Young; Seo, Min-Seok [Seoul National University, Department of Physics and Astronomy and Center for Theoretical Physics, Seoul (Korea, Republic of)

    2013-06-15

    Recent observation shows that the Higgs mass is at around 125 GeV while the prediction of the minimal supersymmetric standard model is below 120 GeV for stop mass lighter than 2 TeV unless the top squark has a maximal mixing. We consider the right-handed neutrino supermultiplets as messengers in addition to the usual gauge mediation to obtain sizeable trilinear soft parameters A{sub t} needed for the maximal stop mixing. Neutrino messengers can explain the observed Higgs mass for stop mass around 1 TeV. Neutrino assistance can also generate charged lepton flavor violation including {mu}{yields}e {gamma} as a possible signature of the neutrino messengers. We consider the S{sub 4} discrete flavor model and show the relation of the charged lepton flavor violation, {theta} {sub 13} of neutrino oscillation and the muon's g-2. (orig.)

  6. The mediation procedure in Romania

    Directory of Open Access Journals (Sweden)

    Alexandrina Zaharia

    2009-06-01

    Full Text Available The mediation activity as an alternative way of solving conflicts occupies an important place in modernsociety. Currently, the mediation reached its maturity worldwide being adopted without reservations.The future of solving conflicts is undoubtedly closely related to mediation. XXth century is the century of solvingconflicts amiably outside the court room. In Romania and the mediation profession were regulated by the Law no.192/2006, on the basis of the idea that mediation is one of the major themes of the reform strategy of the judicialsystem 2005-2007. By adopting the mentioned law it was followed the idea of reducing the volume of activitycourts, and therefore, relieve them of as many cases, with the direct effect on the quality of justice. Mediation is avoluntary process in which the parties with a neutral and impartial third party, without power of decision - themediator - who is qualified to assist the parties to negotiate, facilitating the communication between them andhelping them to reach a unanimous effective and sustainable agreement. The parties may resort to mediation beforeor after triggering a trial. Mediation can be applied, in principle, on any type of conflict. However, theRomanian legislator has established special stipulations on conflict mediation in criminal, civil and familylaw. Although not expressly provided, the stipulations regarding the civil conflicts and also apply to commercialconflicts. Therefore, the mediation is applicable to most types of lawsuits, except those relating to personalrights. As a "win- win" principle, the mediation does not convert any of the parties defeated or victorious; allthose involved have gained by applying this procedure.

  7. Theorizing with/out "Mediators".

    Science.gov (United States)

    Roth, Wolff-Michael; Jornet, Alfredo

    2017-01-05

    Mediation is one of the most often cited concepts in current cultural-historical theory literature, in which cultural actions and artifacts are often characterized as mediators standing between situational stimuli and behavioral responses. Most often presented as a means to overcome Cartesian dualism between subject and object, and between individual and society, some scholars have nonetheless raised criticism suggesting that such mediators are problematic for a dialectical psychology that takes a unit analysis (monist) approach. In fact, Spinoza develops a monist theory of mind and body that goes without and even excludes every form of mediation. In this study, we follow up on the latter criticisms and explore what we consider to be problematic uses of the notion of mediation as an analytical construct in the literature. We elaborate an empirically grounded discussion on the ways the concept of mediation may lead to dualistic readings; and we offer an alternative account where the notion of mediator is not needed. We conclude discussing prospects for and implications of a cultural-historical theory where the notion of mediation no longer is invoked to account for human action and development.

  8. Anomaly mediation deformed by axion

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Kazunori, E-mail: kazunori@hep-th.phys.s.u-tokyo.ac.jp [Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa 277-8583 (Japan); Yanagida, Tsutomu T. [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa 277-8583 (Japan)

    2013-05-13

    We show that in supersymmetric axion models the axion supermultiplet obtains a sizable F-term due to a non-supersymmetric dynamics and it generally gives the gaugino masses comparable to the anomaly mediation contribution. Thus the gaugino mass relation predicted by the anomaly mediation effect can be significantly modified in the presence of axion to solve the strong CP problem.

  9. Practical Guide to Civil Mediation

    CERN Multimedia

    2006-01-01

    The Permanent Mission of Switzerland has informed CERN that the Département des Institutions of the Republic and Canton of Geneva and the Groupement suisse des Magistrats pour la médiation (GEMME) - Swiss Association of Magistrates for Mediation have published a multilingual Practical Guide to Civil Mediation (including English). In this context, the Swiss Mission has underlined the benefits of resorting to mediation, especially for the personnel of International Organizations, and which the Secretary-General of the GEMME has summarised as follows: it is a private process not requiring the waiver of the parties' immunities; the confidentiality of the mediation process is guaranteed both by the mediator and the parties to it; the search for an amicable settlement does not need to be determined by reference to law (provided that public order is respected); the process is faster (2 to 3 sessions), less costly and more flexible than civil or arbitration procedures; in order to reinforce the agreem...

  10. Practical Guide to Civil Mediation

    CERN Multimedia

    2006-01-01

    The Permanent Mission of Switzerland has informed CERN that the Département des Institutions of the Republic and Canton of Geneva and the Groupement suisse des Magistrats pour la médiation (GEMME) - Swiss Association of Magistrates for Mediation have published a multilingual Practical Guide to Civil Mediation (including English). In this context, the Swiss Mission has underlined the benefits of resorting to mediation, especially for the personnel of international organizations, and which the Secretary-General of the GEMME has summarised as follows: it is a private process not requiring the waiver of the parties' immunities; the confidentiality of the mediation process is guaranteed both by the mediator and the parties to it; the search for an amicable settlement does not need to be determined by reference to law (provided that public order is respected); the process is faster (2 to 3 sessions), less costly and more flexible than civil or arbitration procedures; in order to reinforce the agreeme...

  11. Microbially mediated mineral carbonation

    Science.gov (United States)

    Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2010-12-01

    Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O → (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily

  12. 29 CFR 1203.1 - Mediation services.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Mediation services. 1203.1 Section 1203.1 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD APPLICATIONS FOR SERVICE § 1203.1 Mediation services. Applications for the mediation services of the National Mediation Board under section 5, First, of the...

  13. 29 CFR 1202.1 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Mediation. 1202.1 Section 1202.1 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD RULES OF PROCEDURE § 1202.1 Mediation. The mediation..., or where conferences are refused. The National Mediation Board may proffer its services in case...

  14. 22 CFR 143.33 - Mediation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Mediation. 143.33 Section 143.33 Foreign... Mediation. (a) Referral of complaints for mediation. The agency will refer to the Federal Mediation and... participate in the mediation process to the extent necessary to reach an agreement or make an...

  15. 34 CFR 81.13 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Mediation. 81.13 Section 81.13 Education Office of the... Mediation. (a) Voluntary mediation is available for proceedings that are pending before the OALJ. (b) A... mediation by filing a motion with the ALJ assigned to the case. The OALJ arranges for a mediator if...

  16. 24 CFR 3288.35 - Mediation.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Mediation. 3288.35 Section 3288.35...-Administered States § 3288.35 Mediation. (a) Mediator. The dispute resolution provider will provide for the... identifies any other party that should be included in the mediation, the mediator will contact the...

  17. 29 CFR 35.32 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Mediation. 35.32 Section 35.32 Labor Office of the Secretary... Mediation. (a) Referral to mediation. CRC will promptly refer to the Federal Mediation and Conciliation Service or the mediation agency designated by the Secretary of Health and Human Services under 45 CFR...

  18. 44 CFR 7.942 - Mediation.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Mediation. 7.942 Section 7..., Conciliation, and Enforcement Procedures § 7.942 Mediation. (a) FEMA will promptly refer to a mediation agency... participate in the mediation process to the extent necessary to reach an agreement or for the mediator to...

  19. 32 CFR 776.38 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Mediation. 776.38 Section 776.38 National... Professional Conduct § 776.38 Mediation. (a) Mediation: (1) A covered attorney may act as a mediator between... mediation, including the advantages and risks involved, and the effect on the...

  20. Thai and U.S. Community Mediation

    Science.gov (United States)

    Callister, Ronda Roberts; Wall, James A., Jr.

    2004-01-01

    The approaches of 111 Thai and a matched set of 111 U.S. community mediators are investigated. Results show that Thai mediators are more apt to be assertive in their mediations; they put disputants together, demand concessions, criticize disputants, and threaten them more frequently than do U.S. mediators. Thai mediators more frequently seek…

  1. Chloride Accumulators NKCC1 and AE2 in Mouse GnRH Neurons: Implications for GABAA Mediated Excitation.

    Directory of Open Access Journals (Sweden)

    Carol Taylor-Burds

    Full Text Available A developmental "switch" in chloride transporters occurs in most neurons resulting in GABAA mediated hyperpolarization in the adult. However, several neuronal cell subtypes maintain primarily depolarizing responses to GABAA receptor activation. Among this group are gonadotropin-releasing hormone-1 (GnRH neurons, which control puberty and reproduction. NKCC1 is the primary chloride accumulator in neurons, expressed at high levels early in development and contributes to depolarization after GABAA receptor activation. In contrast, KCC2 is the primary chloride extruder in neurons, expressed at high levels in the adult and contributes to hyperpolarization after GABAA receptor activation. Anion exchangers (AEs are also potential modulators of responses to GABAA activation since they accumulate chloride and extrude bicarbonate. To evaluate the mechanism(s underlying GABAA mediated depolarization, GnRH neurons were analyzed for 1 expression of chloride transporters and AEs in embryonic, pre-pubertal, and adult mice 2 responses to GABAA receptor activation in NKCC1-/- mice and 3 function of AEs in these responses. At all ages, GnRH neurons were immunopositive for NKCC1 and AE2 but not KCC2 or AE3. Using explants, calcium imaging and gramicidin perforated patch clamp techniques we found that GnRH neurons from NKCC1-/- mice retained relatively normal responses to the GABAA agonist muscimol. However, acute pharmacological inhibition of NKCC1 with bumetanide eliminated the depolarization/calcium response to muscimol in 40% of GnRH neurons from WT mice. In the remaining GnRH neurons, HCO3- mediated mechanisms accounted for the remaining calcium responses to muscimol. Collectively these data reveal mechanisms responsible for maintaining depolarizing GABAA mediated transmission in GnRH neurons.

  2. Caspases: An apoptosis mediator

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Palai

    2015-03-01

    Full Text Available The process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energy - dependent biochemical mechanisms. Apoptosis is a widely conserved phenomenon helping many processes, including normal cell turnover, proper development and functioning of the immune system, hormone dependent atrophy etc. Inappropriate apoptosis (either low level or high level leads to many developmental abnormalities like, neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer. To use cells for therapeutic purposes through generating cell lines, it is critical to study the cell cycle machinery and signalling pathways that controls cell death and apoptosis. Apoptotic pathways provide a fundamental protective mechanism that decreases cellular sensitivity to damaging events and allow proper developmental process in multi-cellular organisms. Major mediator of apoptosis is a family of proteins known as caspases. There are mainly fourteen types of caspases but out of them only ten caspasese have got essential role in controlling the process of apoptosis. These ten caspases have been categorized into either initiator caspases (caspase 2, 8, 9, 10 or executioner caspases (caspase 3, 6, 7. Although various types of caspases have been identified so far, the exact mechanisms of action of these groups of proteins is still to be fully understood. The aim of this review is to provide a detail overview of role of different caspases in regulating the process of apoptosis.

  3. Relativistic Radiation Mediated Shocks

    CERN Document Server

    Budnik, Ran; Sagiv, Amir; Waxman, Eli

    2010-01-01

    The structure of relativistic radiation mediated shocks (RRMS) propagating into a cold electron-proton plasma is calculated and analyzed. A qualitative discussion of the physics of relativistic and non relativistic shocks, including order of magnitude estimates for the relevant temperature and length scales, is presented. Detailed numerical solutions are derived for shock Lorentz factors $\\Gamma_u$ in the range $6\\le\\Gamma_u\\le30$, using a novel iteration technique solving the hydrodynamics and radiation transport equations (the protons, electrons and positrons are argued to be coupled by collective plasma processes and are treated as a fluid). The shock transition (deceleration) region, where the Lorentz factor $ \\Gamma $ drops from $ \\Gamma_u $ to $ \\sim 1 $, is characterized by high plasma temperatures $ T\\sim \\Gamma m_ec^2 $ and highly anisotropic radiation, with characteristic shock-frame energy of upstream and downstream going photons of a few~$\\times\\, m_ec^2$ and $\\sim \\Gamma^2 m_ec^2$, respectively.P...

  4. Anomaly Mediation and Cosmology

    CERN Document Server

    Basboll, A; Jones, D R T

    2011-01-01

    We consider an extension of the MSSM wherein anomaly mediation is the source of supersymmetry-breaking, and the tachyonic slepton problem is solved by a Fayet-Iliopoulos (FI) $D$-term associated with an additional $U(1)$ symmetry, which also facilitates the see-saw mechanism for neutrino masses and a natural source for the Higgs $\\mu$-term. We explore the cosmological consequences of the model, showing that the model naturally produces a period of hybrid inflation, terminating in the production of cosmic strings. In spite of the presence of a $U(1)$ with an FI term, inflation is effected by the $F$-term, with a $D$-flat tree potential (the FI term being cancelled by non-zero squark and slepton fields). Calculating the 1-loop corrections to the inflaton potential, we estimate the constraints on the parameters of the model from Cosmic Microwave Background data. We briefly discuss the mechanisms for baryogenesis via conventional leptogenesis, the out-of-equilibrium production of neutrinos from the cosmic strings...

  5. Acid Inhibitory Effect of a Combination of Omeprazole and Sodium Bicarbonate (CDFR0209) Compared With Delayed-Release Omeprazole 40 mg Alone in Healthy Adult Male Subjects.

    Science.gov (United States)

    Kim, Kyu-Nam; Yang, Sung-Won; Kim, Hyunil; Kwak, Seong Shin; Kim, Young-Sang; Cho, Doo-Yeoun

    2017-01-23

    CDFR0209, a combination of an immediate-release formulation of omeprazole 40 mg and sodium bicarbonate 1100 mg, has been developed to treat acid-related disorders. We compared the acid inhibitory effects of CDFR0209 and delayed-release omeprazole (omeprazole-DR, Losec 40 mg) after repeated dosing in Helicobacter pylori-negative healthy adult male subjects. In this 2-period crossover study, 30 subjects were randomized to CDFR0209 or omeprazole-DR daily for 7 days. An ambulatory continuous 24-hour intragastric pH recording was performed at baseline and on days 1 and 7 of each administration period. Integrated gastric acidity was calculated from time-weighted average hydrogen ion concentrations at each hour of the 24-hour record. An analysis of variance model was used to test the pharmacodynamic equivalence of CDFR0209 and omeprazole-DR, using the natural logarithmic transformation of the percent decrease from baseline in integrated gastric acidity for the 24-hour interval after the seventh dose of each omeprazole formulation. The geometric least-squares mean ratios (CDFR0209/omeprazole-DR) of the percent decrease from baseline in integrated gastric acidity was 0.98 (90%CI, 0.93-1.07). Both CDFR0209 and omeprazole-DR are equally effective in decreasing integrated gastric acidity at steady state.

  6. Mediation of information and educational mediation: conceptual discussions

    Directory of Open Access Journals (Sweden)

    Helena Célia de Souza Sacerdote

    2016-04-01

    Full Text Available Introduction: This is systematization of theoretical and methodological contributions related to the concepts of mediation information and pedagogical mediation in the literature. Objective: To understand possible intersection of information science and Online Education with regard to these concepts to check that both can be considered as analogous in its essence and practice. Methodology: Literature review based on literature by consulting the scientific productions selected in search of SciELO.ORG databases and EBSCO Host, the portal of CAPES / MEC and Google Scholar. Results: The most cited concepts in information science and education were de Almeida Junior (2009 and Masetto (2013, respectively. Conclusion: It is observed that the concept of mediation can move interchangeably between both areas. This is because the evidence found in the productions of the last five years indicate that the concept of information of mediation seems to have found its bases in education (educational psychology.

  7. Assay of mast cell mediators

    DEFF Research Database (Denmark)

    Rådinger, Madeleine; Jensen, Bettina M; Swindle, Emily

    2015-01-01

    Mediator release from activated mast cells is a major initiator of the symptomology associated with allergic disorders such as anaphylaxis and asthma. Thus, methods to monitor the generation and release of such mediators have widespread applicability in studies designed to understand the processes...... regulating mast cell activation and for the identification of therapeutic approaches to block mast cell-driven disease. In this chapter, we discuss approaches used for the determination of mast cell degranulation, lipid-derived inflammatory mediator production, and cytokine/chemokine gene expression as well...

  8. Doing statistical mediation and moderation

    CERN Document Server

    Jose, Paul E

    2013-01-01

    Written in a friendly, conversational style, this book offers a hands-on approach to statistical mediation and moderation for both beginning researchers and those familiar with modeling. Starting with a gentle review of regression-based analysis, Paul Jose covers basic mediation and moderation techniques before moving on to advanced topics in multilevel modeling, structural equation modeling, and hybrid combinations, such as moderated mediation. User-friendly features include numerous graphs and carefully worked-through examples; ""Helpful Suggestions"" about procedures and pitfalls; ""Knowled

  9. The mediatization of ethical consumption

    Directory of Open Access Journals (Sweden)

    Mikkel Fugl Eskjær

    2013-03-01

    Full Text Available Over the years, mediatization studies have investigated the influence of media in numerous sections of contemporary society. One area that has received limited attention is the mediatization of consumption, particularly issues concerning ethical consumption. This article presents a study of how mediatization is transforming modern consumption and contributing to the mainstreaming of ethical consumption. Based on a study of a Danish online eco-store, the article argues that modern ethical consumption increasingly depends on new media practices to present sustainable consumption as practical and fashionable while effacing underlying processes of rationalisation and commercialisation.

  10. The mediatization of ethical consumption

    DEFF Research Database (Denmark)

    Eskjær, Mikkel Fugl

    2013-01-01

    Over the years, mediatization studies have investigated the influence of media in numerous sections of contemporary society. One area that has received limited attention is the mediatization of consumption, particularly issues concerning ethical consumption. This article presents a study of how...... mediatization is transforming modern consumption and contributing to the mainstreaming of ethical consumption. Based on a study of a Danish online eco-store, the article argues that modern ethical consumption increasingly depends on new media practices to present sustainable consumption as practical...

  11. Gauge Mediation in String Theory

    OpenAIRE

    Kawano, Teruhiko; Ooguri, Hirosi; Ookouchi, Yutaka

    2007-01-01

    We show that a large class of phenomenologically viable models for gauge mediation of supersymmetry breaking based on meta-stable vacua can be realized in local Calabi–Yau compactifications of string theory.

  12. 重碳酸盐碱度对电吸附脱盐效果的影响研究%Research on the Influence of Bicarbonate Alkalinity on Desalination Effect of Electro - sorption.

    Institute of Scientific and Technical Information of China (English)

    石文忠; 孙英战; 谢海燕

    2012-01-01

    为了解重碳酸盐碱度对电吸附设备脱盐效果的影响,以乌鲁木齐高新区北区再生水厂的出水作为原水,对不同HCO3^-浓度情况下电吸附设备连续运行的脱盐效果进行了研究。结果表明,进水HCO3^-浓度为170、260和440mg/L三种工况下,电吸附设备连续运行6个周期,除第1周期对TDS、氯离子和总硬度的去除率较低外,其余5个周期对三者及HCO3^-的去除率均呈逐渐下降的趋势,在HCO3^-浓度为440mg/L时,去除率下降最为明显;与其他离子不同的是,进水HCO3^-浓度越高,HCO3^-去除率越高,且第1周期去除率最高。分析认为在高重碳酸盐碱度工况下,HCO3^-与钙等硬度离子相互作用,导致电极板结垢,从而影响电吸附设备的脱盐效果。另外,在极板结垢的基础上,对原水中的重碳酸盐进行酸化吹脱,在进水HCO3^-浓度为100mg/L条件下设备连续运行,结果发现进水HCO3^-浓度较低时,可改善电吸附设备的脱盐效果。%To recognize the influence of bicarbonate alkalinity on desalination effect of electro - sorption, this article using the resurgent water of North district recycling plant of Urumqi High - teeh Zone as raw water, researches on desalination effect of electro - sorption equipment continuous operation under the different concentration of HCO3 The result shows that, the influent HCO3 - concentration is controlled in three conditions which are 170 mg/L, 260 mg/L and 440 mg/L. Electro - sorption equipment continuous runs for 6 cycles, in addition to TDS, Cl^ - and total bardhess removal rates are low in the first cycle, removal rates of three ions and HCO3 - are gradually downtrend in the re- maining 5 cycles. Qhen HCO3 - concentration is 440 mg/L, the removal rate decreases significantly. The difference with other ions is that the higher the concentration of influent HCO3 ^-, the higher the removal rate of HCO3^- , and the highest rate of

  13. Evaluation of the controlling Pomacea canaliculata with calcium oxide, ammonium bicarbonate, Camellia oleifera powder and tea saponin%茶皂素、生石灰等防治稻田福寿螺的效果评估

    Institute of Scientific and Technical Information of China (English)

    王志高; 谭济才; 刘军; 王卫国

    2011-01-01

    Abstract: Pomacea canaliculata (Lamarck) is one of the most serious pests to the rice production area in southern China. In order to solve the problem caused by synthetic chemical molluscicides which are extremely toxic to the environment and agricultural products, we studied the efficiency of controlling P. canaliculata with four kinds of substitutes, calcium oxide, ammonium bicarbonate, Camellia oleifera powder and tea saponin, in laboratory and plot. The results indicated that the better control efficiency achieved using tea saponin, C. oleifera powder and calcium oxide. The mortality of snails achieved to 100% when the concentration of tea saponin was 40 mg/L and 50 mg/L, and treated for 48 h in laborato- ry. In the plot, mortality of snails were 100% using tea saponin at 6.0 g/m^2 with 4 days or 1.5 g/m^2 lasted 16 days. The quick-acting and lasting effect were better than those of other substitutes. Control efficiencies of C. oleifera powder at 30 g/m^2 and 45 g/m^2 and calcium oxide treatment at 45 g/m^2 are over 80% after 15 days. In addition, these three kinds of substitutes can control the Echirtochloa crusgalli (L.) Beauv effectively in the rice paddy. Ammonium bicarbonate was less effective on controlling P. canaliculata, and can promote the occurrence of E. crusgaUi. We concluded that tea saponin, C. oleifera powder and calcium oxide can be used as the substitutes of synthetic chemical molluscicides for contro- lling P. canaliculata in the rice paddy.%福寿螺已成为我国南方局部稻区严重危害水稻的有害生物,为解决常用的化学杀螺剂污染环境和农产品的问题,分别在室内和大田环境下研究了生石灰、碳酸氢铵、茶麸和茶皂素4种替代物质防治福寿螺的效果。茶皂素、茶麸和生石灰对稻田福寿螺有很好的防治作用。在室内试验中40 mg/L和50mg/L茶皂素处理在48h即达到了100%的防效;在大田试验中茶皂素6.0g/m^2的处理在第4天、1.5g/m^2

  14. 14 CFR 1252.402 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Mediation. 1252.402 Section 1252.402... Procedures § 1252.402 Mediation. (a) Referral of complaints for mediation. NASA will refer to the Federal Mediation and Conciliation Service all complaints that: (1) Fall within the jurisdiction of the Act...

  15. Mediation in Schools: Tapping the Potential

    Science.gov (United States)

    Hendry, Richard

    2010-01-01

    This article explores the developing role of mediation as a conflict resolution process in schools. It gives an accepted definition and clarifies the purposes of mediation, outlining the range of contexts in and beyond schools in which mediation is already offered as a formal intervention. The typical process of mediation itself is described. The…

  16. 45 CFR 91.43 - Mediation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Mediation. 91.43 Section 91.43 Public Welfare... Enforcement Procedures § 91.43 Mediation. (a) HHS will promptly refer to a mediation agency designated by the... mediation process to the extent necessary to reach an agreement or make an informed judgment that...

  17. 38 CFR 18.543 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Mediation. 18.543 Section... Enforcement Procedures § 18.543 Mediation. (a) Referral of complaints for mediation. VA will refer to the Federal Mediation and Conciliation Service all complaints that: (1) Fall within the jurisdiction of...

  18. Mediation and Counseling Services: A Viable Partnership

    Science.gov (United States)

    Hodges, Shannon

    2009-01-01

    Mediation has become common in many areas of society, including marital dissolution, community disputes, governmental agencies, and business and industry. Though higher education has been slower than society to adopt mediation services, campus mediation is becoming increasingly more common. This article explains why mediation is a viable…

  19. 45 CFR 1156.16 - Mediation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Mediation. 1156.16 Section 1156.16 Public Welfare... Procedures § 1156.16 Mediation. (a) Referral of complaints for mediation. The Endowment will promptly refer all complaints to the agency designated by the Secretary of HHS to manage the mediation process...

  20. 15 CFR 923.54 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Mediation. 923.54 Section 923.54... Mediation. (a) Section 307(h) of the Act provides for mediation of serious disagreement between any Federal... cases, mediation by the Secretary, with the assistance of the Executive Office of the President, may...

  1. 15 CFR 20.12 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Mediation. 20.12 Section 20.12... Procedures § 20.12 Mediation. (a) DOC will refer to a mediation service designated by the Secretary all... further processing. (b) Both the complainant and the recipient shall participate in the mediation...

  2. 24 CFR 146.35 - Mediation.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Mediation. 146.35 Section 146.35... ASSISTANCE Investigation, Settlement, and Enforcement Procedures § 146.35 Mediation. (a) HUD shall refer to the Federal Mediation and Conciliation Service, a mediation agency designated by the Secretary...

  3. 10 CFR 1040.89-6 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Mediation. 1040.89-6 Section 1040.89-6 Energy DEPARTMENT... Enforcement Procedures § 1040.89-6 Mediation. (a) Referral of complaints for mediation. DOE will refer to the Federal Mediation and Conciliation Service, in accordance with 45 CFR 90.43(c)(3), all complaints that:...

  4. 43 CFR 17.332 - Mediation.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Mediation. 17.332 Section 17.332 Public..., and Enforcement Procedures § 17.332 Mediation. (a) Referral of complaints for mediation. DOI will... participate in the mediation process to the extent necessary to reach an agreement or make an...

  5. 7 CFR 614.11 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Mediation. 614.11 Section 614.11 Agriculture... AGRICULTURE CONSERVATION OPERATIONS NRCS APPEAL PROCEDURES § 614.11 Mediation. (a) A participant who wishes to pursue mediation must file request for mediation under this part with the NRCS official designated in...

  6. 22 CFR 218.33 - Mediation.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Mediation. 218.33 Section 218.33 Foreign... § 218.33 Mediation. (a) Referral of complaints for mediation. The agency will refer to the Federal Mediation and Conciliation Service all complaints that: (1) fall within the jurisdiction of...

  7. 15 CFR 930.111 - OCRM mediation.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false OCRM mediation. 930.111 Section 930... FEDERAL CONSISTENCY WITH APPROVED COASTAL MANAGEMENT PROGRAMS Secretarial Mediation § 930.111 OCRM mediation. The availability of mediation does not preclude use by the parties of alternative means...

  8. 10 CFR 4.333 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Mediation. 4.333 Section 4.333 Energy NUCLEAR REGULATORY... Investigation, Conciliation, and Enforcement Procedures § 4.333 Mediation. (a) Referral of complaints for mediation. NRC will refer to a mediation agency designated by the Secretary of the Department of Health...

  9. 7 CFR 780.9 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Mediation. 780.9 Section 780.9 Agriculture Regulations... PROGRAMS APPEAL REGULATIONS § 780.9 Mediation. (a) Any request for mediation must be submitted after... once: (1) If resolution of an adverse decision is not achieved in mediation, a participant may...

  10. Uso de bicarbonato e lactato-L para correção da acidose metabólica sistêmica em bovinos com acidose láctica ruminal aguda Use of bicarbonate and lactate L for correction of systemic metabolic acidosis in cattle with acute rumen lactic acidosis

    Directory of Open Access Journals (Sweden)

    M.L.R. Leal

    2007-08-01

    Full Text Available Foram utilizados seis novilhos, providos de cânula ruminal, em delineamento experimental cross-over, para comparar a eficiência de soluções de bicarbonato de sódio e lactato-L de sódio na correção da acidose metabólica sistêmica (AMS, causada pela acidose láctica ruminal (ALR. Vinte horas após, quando apresentavam intensa AMS, os animais foram distribuídos aleatoriamente e tratados com cinco litros de 150mMol/l de bicarbonato de sódio ou de lactato-L de sódio, infundidas por via intravenosa, nas quatro horas seguintes. Amostras de sangue, para hemogasometria, foram coletadas no decorrer da infusão a zero, 1, 2, 3, 4, 6 e 8 horas. Ambos os tratamentos elevaram o pH sangüíneo já na primeira hora pós-infusão, corrigindo adequadamente a AMS. O tratamento com lactato-L de sódio aumentou as concentrações de bicarbonato, TCO2 e EAB sangüíneos já na segunda hora pós-infusão; com o bicarbonato essa elevação ocorreu a partir da terceira hora. Não houve diferenças entre tratamentos para pH sangüíneo, bicarbonato, TCO2 e excesso de base. Vinte e quatro horas após o tratamento todos os novilhos apresentaram plena recuperação. O lactato-L pode substituir o bicarbonato na correção da AMS em novilhos com ALR.The efficiency of sodium bicarbonate or l-lactate for correcting systemic metabolic acidosis (SMA caused by rumen lactic acidosis (RLA was evaluated using six rumen-cannulated steers in a cross-over experimental design. RLA was induced by administration of sucrose, intraruminally. Twenty hours later when the animals developed an intense SMA, the steers were randomly distributed and treated intravenously either with 5l of 15 mMol/l sodium bicarbonate or L-lactate solution, infused throughout 4h. Blood samples were colleted throughout the infusion at zero, 1, 2, 3, 4, 6 and 8h, for blood gas analysis. After 1hour, both sodium bicarbonate and L-lactate solutions increased blood pH and corrected adequately the SMA. Blood

  11. Rescue of the temperature-sensitive, autosomal-recessive mutation R298S in the sodium-bicarbonate cotransporter NBCe1-A characterized by a weakened dimer and abnormal aggregation

    Science.gov (United States)

    Gill, Harindarpal S.; Choi, Kun-Young; Kammili, Lakshmi; Popratiloff, Anastas

    2015-01-01

    Background Band keratopathy, an ocular disease that is characterized by hypercalcemia and opaque bands across the cornea, has been associated with kidney disease. Type-II renal tubular acidosis (RTA), a condition in which the kidneys fail to recover bicarbonate (HCO3−) in the proximal tubule of the nephron, results in HCO3− wastage in the urine and low blood pH. The development of these diseases is associated with autosomal-recessive mutations in the Na+-coupled HCO3− cotransporter NBCe1-A located at the basolateral membranes of either cell type. Methods We provide insight into the devastating R298S mutation found in type-II RTA-afflicted individuals using confocal-microscopy imaging of fluorescently-tagged NBCe1-A and NBCe1-A-R298S molecules expressed in human corneal endothelial and proximal tubule cells and from in-depth biophysical studies of their cytoplasmic N-terminal domains (Nt and Nt-R298S), including Nt crystal structure, melting-temperature, and homodimer dissociation constant (KD) analyses. Results We illuminate and rescue trafficking defects of the R298S mutation of NBCe1-A. The KD for Nt monomer-dimer equilibrium is established. The KD for Nt-R298S is significantly higher, but immeasurable due to environmental factors (pH, temperature, concentration) that result in dimer instability leading to precipitation. The crystal structure of Nt-dimer shows that R298 is part of a putative substrate conduit and resides near the dimer interface held together by hydrogen-bond networks. Conclusions The R298S is a temperature-sensitive mutation in Nt that results in instability of the colloidal system leading to abnormal aggregation. General significance Our findings provide new perspectives to the aberrant mechanism of certain ocular pathologies and type-II RTA associated with the R298S mutation. PMID:25743102

  12. EST Table: FS829498 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available FS829498 E_FL_fmgV_32C07_R_0 10/09/28 34 %/210 aa ref|XP_001656347.1| bestrophin 2,...3,4 [Aedes aegypti] gb|EAT45610.1| bestrophin 2,3,4 [Aedes aegypti] 10/09/10 32 %/234 aa FBpp0113082|Best1-P

  13. EST Table: FS735977 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available FS735977 E_FL_bmmt_04J24_R_0 11/12/09 n.h 10/09/28 36 %/182 aa ref|XP_001865897.1| best...rophin 2,3,4 [Culex quinquefasciatus] gb|EDS42461.1| bestrophin 2,3,4 [Culex quinquefasciatus] 10/09/03

  14. EST Table: FY748702 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available FY748702 E_FL_famL_39P03_F_0 11/11/04 79 %/157 aa ref|XP_001656347.1| bestrophin 2,...3,4 [Aedes aegypti] gb|EAT45610.1| bestrophin 2,3,4 [Aedes aegypti] 11/11/04 63 %/157 aa FBpp0251679|DwilGK2

  15. Mediation in Legal English Teaching

    Directory of Open Access Journals (Sweden)

    Chovancová Barbora

    2016-06-01

    Full Text Available Mediation is a language activity that has been unjustly neglected when preparing law students for their future professional careers. When trained in a professional context, students need to develop and improve complex communicative skills. These include not only the traditional language skills such as reading, writing, listening and speaking, but also more advanced skills such as summarizing, providing definitions, changing registers etc. All these are involved in the students’ acquisition of ‘soft skills’ that are particularly important for students of law since much of their future work involves interpersonal lawyer-client interaction. This article argues that mediation is a crucial (though previously underestimated skill and that law-oriented ESP instruction should provide training aimed at developing this skill. Showing a practical application of this approach, the paper demonstrates that mediation can be successfully integrated in the legal English syllabus and make the learning of legal English more effective.

  16. Assistive Technology and Affective Mediation

    Directory of Open Access Journals (Sweden)

    Nestor Garay

    2006-01-01

    Full Text Available The lack of attention towards affective communication in assistive technology and disability research can be potentially overcome thanks to the development of affective computing and affective mediation areas. This document describes the main impairments and disorders that may involve affective communication deficits. We also present several affective mediation technologies that are being applied or may be integrated in assistive technologies in order to improve affective communication for a range of disabilities. Finally, we describe our experience with Gestele, an application that incorporates multimodal elements of affective mediation for people with mobility impairments, as well as the results of an empirical study conducted to evaluate the application’s validity in communication via telephone.

  17. Three tasks for mediatization research

    DEFF Research Database (Denmark)

    Ekstrøm, Mats; Fornäs, Johan; Jansson, André;

    2016-01-01

    Based on the interdisciplinary experience of a Swedish research committee, this article discusses critical conceptual issues raised by the current debate on mediatization – a concept that holds great potential to constitute a space for synthesized understandings of media-related social...... that mediatization researchers have sometimes formulated too grand claims as to mediatization’s status as a unitary approach, a meta-theory or a paradigm. Such claims have led to problematic confusions around the concept and should be abandoned in favour of a more open agenda. In line with such a call for openness...... transformations. In contrast to other, more metaphorical constructions, mediatization can be studied empirically in systematic ways through various sub-processes that together provide a complex picture of how culture and everyday life evolve in times of media saturation. The first part of this article argues...

  18. Nursing as textually mediated reality.

    Science.gov (United States)

    Cheek, J; Rudge, T

    1994-11-01

    Nursing and nursing practice both construct and are in turn constructed by the context in which they operate. Texts plays a central part in that construction. As such, nursing and nursing practice can be considered to represent a reality that is textually mediated. This paper explores the notion of nursing as a textually mediated reality and offers the reader the possibility of engaging in reflection on what implications this has for nursing and their own nursing practice. The analyses provided draw on aspects of the work of both Foucault and Derrida. Foucault's notion of discourse provides a vehicle for the exploration of nursing as textually mediated, as does Derrida's concept of binary oppositions. The paper thus illustrates some of the possibilities afforded nursing by poststructural analyses. In particular it does this by exploring one of the central textual constructions, impacting on the way that nursing and nursing practice are conceptualized, the mind/body binary opposition.

  19. Dynamical Messengers for Gauge Mediation

    Energy Technology Data Exchange (ETDEWEB)

    Hook, Anson; Torroba, Gonzalo; /SLAC /Stanford U., Phys. Dept.

    2011-08-17

    We construct models of indirect gauge mediation where the dynamics responsible for breaking supersymmetry simultaneously generates a weakly coupled subsector of messengers. This provides a microscopic realization of messenger gauge mediation where the messenger and hidden sector fields are unified into a single sector. The UV theory is SQCD with massless and massive quarks plus singlets, and at low energies it flows to a weakly coupled quiver gauge theory. One node provides the primary source of supersymmetry breaking, which is then transmitted to the node giving rise to the messenger fields. These models break R-symmetry spontaneously, produce realistic gaugino and sfermion masses, and give a heavy gravitino.

  20. Secure mediated certificateless signature scheme

    Institute of Scientific and Technical Information of China (English)

    YANG Chen; MA Wen-ping; WANG Xin-mei

    2007-01-01

    Ju et al proposed a certificateless signature scheme with instantaneous revocation by introducing security mediator (SEM) mechanism. This article presents a detailed cryptoanalysis of this scheme and shows that, in their proposed scheme, once a valid signature has been produced, the signer can recover his private key information and the instantaneous revocation property will be damaged. Furthermore, an improved mediated signature scheme, which can eliminate these disadvantages, is proposed, and security proof of the improved scheme under elliptic curve factorization problem (ECFP) assumption and bilinear computational diffie-hellman problem (BCDH) assumption is also proposed.

  1. Should Lawyers Act as Mediators?

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    On September 1, the Henan Provincial Department of Justice and the Henan Higher People’s Court jointly issued a document. It suggests lawyers do as much as possible to mediate between litigants involved in lawsuits of civil disputes and misdemeanor lawsuits, in order to help them

  2. Three tasks for mediatization research

    DEFF Research Database (Denmark)

    Ekstrøm, Mats; Fornäs, Johan; Jansson, André

    2016-01-01

    Based on the interdisciplinary experience of a Swedish research committee, this article discusses critical conceptual issues raised by the current debate on mediatization – a concept that holds great potential to constitute a space for synthesized understandings of media-related social transforma......Based on the interdisciplinary experience of a Swedish research committee, this article discusses critical conceptual issues raised by the current debate on mediatization – a concept that holds great potential to constitute a space for synthesized understandings of media-related social...... transformations. In contrast to other, more metaphorical constructions, mediatization can be studied empirically in systematic ways through various sub-processes that together provide a complex picture of how culture and everyday life evolve in times of media saturation. The first part of this article argues...... that mediatization researchers have sometimes formulated too grand claims as to mediatization’s status as a unitary approach, a meta-theory or a paradigm. Such claims have led to problematic confusions around the concept and should be abandoned in favour of a more open agenda. In line with such a call for openness...

  3. Mediated Encryption: Analysis and Design

    Directory of Open Access Journals (Sweden)

    I. Elashry1

    2015-01-01

    Full Text Available Boneh, Ding and Tsudik presented identity-based mediated RSA encryption and signature systems in which the users are not allowed to decrypt/sign messages without the authorisation of a security mediator.We show that ID-MRSA is not secure and we present a secure modified version of it which is as efficient as the original system. We also propose a generic mediated encryption that translates any identity based encryption to a mediated version of this IBE. It envelops an IBE encrypted message using a user’s identity into an IBE envelope using the identity of the SEM. We present two security models based on the role of the adversary whether it is a revoked user or a hacked SEM. We prove that GME is as secure as the SEM’s IBE against a revoked user and as secure as the user’s IBE against a hacked SEM. We also present two implementations of GME based on Boneh-Franklin FullIBE system which is a pairing-based system and Boneh, Gentry and Hamburg (BGH system which is pairing-free system.

  4. Eicosanoids mediate insect hemocyte migration

    Science.gov (United States)

    Hemocyte chemotaxis toward infection and wound sites is an essential component of insect defense reactions, although the biochemical signal mechanisms responsible for mediating chemotaxis in insect cells are not well understood. Here we report on the outcomes of experiments designed to test the hyp...

  5. Anomaly mediation in superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Conlon, J.P. [Rudolf Peierls Center for Theoretical Physics, 1 Keble Road, Oxford, OX1 3NP (United Kingdom); Balliol College, Oxford, OX1 3BJ (United Kingdom); Kavli Institute of Theoretical Physics, Kohn Hall, University of California, Santa Barbara CA 93106-4030 (United States); Goodsell, M. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22603 Hamburg (Germany); Palti, E. [Centre de Physique Theorique, Ecole Polytechnique, CNRS, 91128 Palaiseau (France)

    2011-01-15

    We study anomaly mediated supersymmetry breaking in type IIB string theory and use our results to test the supergravity formula for anomaly mediated gaugino masses. We compute 1-loop gaugino masses for models of D3-branes on orbifold singularities with 3-form fluxes by calculating the annulus correlator of 3-form flux and two gauginos in the zero momentum limit. Consistent with supergravity expectations we find both anomalous and running contributions to 1-loop gaugino masses. For background Neveu-Schwarz H-flux we find an exact match with the supergravity formula. For Ramond-Ramond flux there is an off-shell ambiguity that precludes a full matching. The anomaly mediated gaugino masses, while determined by the infrared spectrum, arise from an explicit sum over UV open string winding modes. We also calculate brane-to-brane tree-level gravity mediated gaugino masses and show that there are two contributions coming from the dilaton and from the twisted modes, which are suppressed by the full T{sup 6} volume and the untwisted T{sup 2} volume respectively. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Anomaly mediation in superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Conlon, Joseph P. [Rudolf Peierls Center for Theoretical Physics, Oxford (United Kingdom); Balliol College, Oxford (United Kingdom); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Palti, Eran [Centre de Physique Theoretique, Ecole Polytechnique, CNRS, Palaiseau (France)

    2010-08-15

    We study anomaly mediated supersymmetry breaking in type IIB string theory and use our results to test the supergravity formula for anomaly mediated gaugino masses. We compute 1-loop gaugino masses for models of D3-branes on orbifold singularities with 3-form fluxes by calculating the annulus correlator of 3-form flux and two gauginos in the zero momentum limit. Consistent with supergravity expectations we find both anomalous and running contributions to 1-loop gaugino masses. For background Neveu-Schwarz H-flux we find an exact match with the supergravity formula. For Ramond-Ramond flux there is an off-shell ambiguity that precludes a full matching. The anomaly mediated gaugino masses, while determined by the infrared spectrum, arise from an explicit sum over UV open string winding modes. We also calculate brane-to-brane tree-level gravity mediated gaugino masses and show that there are two contributions coming from the dilaton and from the twisted modes, which are suppressed by the full T{sup 6} volume and the untwisted T{sup 2} volume respectively. (orig.)

  7. Duodenal Intracellular Bicarbonate and the 'CF Paradox'

    Directory of Open Access Journals (Sweden)

    Kaunitz JD

    2001-07-01

    Full Text Available HCO(3(- secretion, which is believed to neutralize acid within the mucus gel, is the most studied duodenal defense mechanism. In general, HCO(3(- secretion rate and mucosal injury susceptibility correlate closely. Recent studies suggest that luminal acid can lower intracellular pH (pH(i of duodenal epithelial cells and that HCO(3(- secretion is unchanged during acid stress. Furthermore, peptic ulcers are rare in cystic fibrosis (CF, although, with impaired HCO(3(- secretion, increased ulcer prevalence is predicted, giving rise to the 'CF Paradox'. We thus tested the hypothesis that duodenal epithelial cell protection occurs as the result of pH(i regulation rather than by neutralization of acid by HCO(3(- in the pre-epithelial mucus. Cellular acidification during luminal acid perfusion, and unchanged HCO(3(- secretion during acid stress are inconsistent with pre-epithelial acid neutralization by secreted HCO(3(-. Furthermore, inhibition of HCO(3(- secretion by 5-nitro-2-(3-phenylpropylamino benzoic acid (NPPB despite preservation of pH(i and protection from acid-induced injury further question the pre-epithelial acid neutralization hypothesis. This decoupling of HCO(3(- secretion and injury susceptibility by NPPB (and possibly by CF further suggest that cellular buffering, rather than HCO(3(- exit into the mucus, is of primary importance for duodenal mucosal protection, and may account for the lack of peptic ulceration in CF patients.

  8. Lubiprostone Stimulates Duodenal Bicarbonate Secretion in Rats

    OpenAIRE

    Mizumori, Misa; Akiba, Yasutada; Kaunitz, Jonathan D.

    2009-01-01

    Background Lubiprostone, a bicyclic fatty acid, is used for the treatment of chronic constipation. No published study has addressed the effect of lubiprostone on intestinal ion secretion in vivo. Aim The aim of this study was to test the hypothesis that lubiprostone augments duodenal HCO3 − secretion (DBS). Methods Rat proximal duodenal loops were perfused with pH 7.0 Krebs, control vehicle (medium-chain triglycerides), or lubiprostone (0.1–10 μM). We measured DBS with flow-through pH and CO2...

  9. In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate Eficiência antimicrobiana in vitro de um enxaguatório bucal contendo triclosan/gantrez e bicarbonato de sódio

    Directory of Open Access Journals (Sweden)

    Juliana Rico Pires

    2007-12-01

    Full Text Available Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis. Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC. The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers’ saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.Diversas substâncias antisépticas têm sido utilizadas como adjuntos aos procedimentos mecânicos rotineiros de higiene oral, com base em seus efeitos antimicrobianos. O objetivo deste estudo foi avaliar, in vitro, a eficiência antimicrobiana de um enxaguatório bucal contendo Triclosan/Gantrez e bicarbonato de sódio, em comparação a controles positivos e negativos. Linhagens padrão de Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus e Bacillus subtilis foram utilizadas. Amostras de Streptococcus mutans e Bacilos Gram-negativos foram coletadas de 20 voluntários (10 com um periodonto clinicamente saudável e 10 com gengivite associada à presença de biofilme. A avaliação da atividade antimicrobiana foi

  10. Pathogen identification and pathogenic biology of sclerotiniose blight of rice stem rot in sodium bicarbonate soils%苏打盐碱地水稻秆腐菌核病病原鉴定及其生物学特性

    Institute of Scientific and Technical Information of China (English)

    张佳环; 刘巍; 潘姣; 邵玺文; 王志春; 敖振超; 柳建; 刘畅; 马周杰

    2015-01-01

    对苏打盐碱地水稻秆腐菌核病病原进行了分离、鉴定和生物学特性的研究。结果表明,该病原菌菌核黑色圆球状,表面凸凹形态,直径164~309μm,内部褐色拟薄壁组织;分生孢子淡褐色,1~3个隔膜,大小为(32~76)μm ×(5~22)μm;无性世代为 Nakataea sigmoidea ,有性世代为 Magnaporthe salvinii 。病原菌在25~30℃时生长较好,利用鼠李糖(P <0.05)、硝酸钙(P <0.05)和硫酸锌(P <0.01)能力最强,在利用碳氮源和微量元素方面,与弱酸性和寒冷地水稻秆腐菌核病病原存在差异。%The biological characteristics of the pathogen causing sclerotiniose blight of rice stem rot was isolated,i-dentified,and studied.The results showed that the pathogenic fungus sclerotia was black,knaggy,globular out-side,1 64-309 μm in diameter,and brown inside,and the pathogenic conidia were light brown,1 -3 septates, and (32-76)μm×(5-22)μm in size.The pathogenic asexual generation was Nakataea sigmoidea ,and the sexual generation was Magnaporthe salvinii .The optimum temperature was from 25 ℃ to 30 ℃ for growth of the patho-gen.Rhamnose (P <0.05 ),calcium nitrate (P < 0.05 ),and zinc sulfate (P < 0.01 )had significant promoting effect on the growth of the mycelia.The pathogen showed difference in the utilization of carbon source,nitrogen source,and microelements from the pathogens from non-sodium bicarbonate soils.

  11. 磷石膏-碳铵-氨水球磨制备硫酸铵和碳酸钙%Ammonium Sulfate and Calcium Carbonate Prepared by Ball-milling from Phosphogypsum-Ammonium Bicarbonate-Ammonia Water

    Institute of Scientific and Technical Information of China (English)

    李娜; 邓跃全; 董发勤; 罗绍东; 李珊珊; 彭宝瑶

    2013-01-01

    Ammonium sulfate and calcium carbonate were prepared using phosphogypsum, ammonium bicarbonate and ammonia water as raw materials by ball-milling technique. The optimum conditions were explored through orthogonal test, the major elements and phase composition of two kinds of products were analyzed by XRF and XRD, and the grain size distribution and poisonous elements of calcium carbonate were determined using laser particle size analyzer and ICP. The analysis results showed that the optimum technological conditions were as follows: the liquid-solid ratio was 0.5, the response time was 45 min, the ball-material ratio was 3:1, rotational speed was 600 r/min, and the average conversion reaction was up to 97.95%; the product quality of ammonium sulfate reached the standard of byproduct ammonium sulfate, poisonous and harmful elements contents of calcium carbonate were far lower than quality criteria of soil environment allows. Preparation of ammonium sulfate and calcium carbonate from phosphogypsum by ball-milling achieved the purpose of effectively using phosphogypsum.%  以磷石膏、碳酸氢铵和氨水为原料,采用球磨工艺制备硫酸铵和碳酸钙.通过正交试验设计,探索磷石膏球磨制备硫酸铵和碳酸钙的最佳工艺条件,采用 XRF 和 XRD 分析了2种产物的化学组成及物相组成,采用激光粒度仪和 ICP 分别测定了碳酸钙的粒度分布及有毒有害元素含量.结果表明,球磨制备硫酸铵和碳酸钙适宜的工艺条件为:液固比0.5,反应时间45 min,球料比3∶1,转速600 r/min,反应的平均转化率达97.95%;硫酸铵产品质量达到了副产硫酸铵标准,碳酸钙中有毒有害元素的含量远低于土壤环境质量标准要求.磷石膏球磨制备硫酸铵和碳酸钙,实现了磷石膏的高效利用.

  12. Dissolution experiments of commercial PWR (52 MWd/kgU) and BWR (53 MWd/kgU) spent nuclear fuel cladded segments in bicarbonate water under oxidizing conditions. Experimental determination of matrix and instant release fraction

    Science.gov (United States)

    González-Robles, E.; Serrano-Purroy, D.; Sureda, R.; Casas, I.; de Pablo, J.

    2015-10-01

    The denominated instant release fraction (IRF) is considered in performance assessment (PA) exercises to govern the dose that could arise from the repository. A conservative definition of IRF comprises the total inventory of radionuclides located in the gap, fractures, and the grain boundaries and, if present, in the high burn-up structure (HBS). The values calculated from this theoretical approach correspond to an upper limit that likely does not correspond to what it will be expected to be instantaneously released in the real system. Trying to ascertain this IRF from an experimental point of view, static leaching experiments have been carried out with two commercial UO2 spent nuclear fuels (SNF): one from a pressurized water reactor (PWR), labelled PWR, with an average burn-up (BU) of 52 MWd/kgU and fission gas release (FGR) of 23.1%, and one from a boiling water reactor (BWR), labelled BWR, with an average BU of and 53 MWd/kgU and FGR of 3.9%. One sample of each SNF, consisting of fuel and cladding, has been leached in bicarbonate water during one year under oxidizing conditions at room temperature (25 ± 5)°C. The behaviour of the concentration measured in solution can be divided in two according to the release rate. All radionuclides presented an initial release rate that after some days levels down to a slower second one, which remains constant until the end of the experiment. Cumulative fraction of inventory in aqueous phase (FIAPc) values has been calculated. Results show faster release in the case of the PWR SNF. In both cases Np, Pu, Am, Cm, Y, Tc, La and Nd dissolve congruently with U, while dissolution of Zr, Ru and Rh is slower. Rb, Sr, Cs and Mo, dissolve faster than U. The IRF of Cs at 10 and 200 days has been calculated, being (3.10 ± 0.62) and (3.66 ± 0.73) for PWR fuel, and (0.35 ± 0.07) and (0.51 ± 0.10) for BWR fuel.

  13. Electrochemical properties of the 304 and 316L stainless steel in different sodium bicarbonate solution%基于碳酸氢钠溶液的304与316L不锈钢电化学试验研究

    Institute of Scientific and Technical Information of China (English)

    俞树荣; 陈科丰

    2013-01-01

    采用电化学噪声、动电位极化和电容测量方法研究了304、316L不锈钢在不同NaHCO3溶液中的电化学行为及生成钝化膜的半导体性质.在NaHCO3溶液中,304、316L不锈钢存在明显相近的钝化区间;点蚀电位、零电流电位随着NaHCO3浓度的增大而减小.在0.5V电位形成钝化膜的Mott-Schottky曲线表明,304、316L不锈钢在NaHCO3溶液中生成的钝化膜为双层结构,具有相近的成膜特性.但随着NaHCO3溶液浓度变化所生成钝化膜的性质也不同,304不锈钢形成的表面膜稳定性稍好于316L.%Tha methods of electrochemical noise,potentiodynamic polarization and capacitance measurement have been employed to explore the electrochemical properties of the 304 and 316L stainless steel in different sodium bicarbonate solution and the semiconductor properties of passive formation.The 304 and 316L stainless steel hold an approximate passive area in the NaHCO3 solution.The pitting electric potential and the zero current electric potential decline with the increase of the NaHCO3 concentration.The passive Mott-Schottky curve in 0.5v showed that the passive films of the 304 and 306L stainless steel formed in the NaHCO3 solution are double-layer,both of which had the similar films forming characteristics.However,the passive film properties changed with the different NaHCO3 concentration.Furthermore,the surface film formed on 304 stainless steel exhibits a little better stability than that of 316L.

  14. Treatment of sodium bicarbonate combined with extracorporeal shock wave lithotripsy for renal uric acid stone and review of the literature%碳酸氢钠联合ESWL治疗双J管末端尿酸结石1例报告并文献复习

    Institute of Scientific and Technical Information of China (English)

    李浩勇; 梁培育; 周治彦; 宋鹏; 彭晓晖; 颜毅; 刘继红

    2012-01-01

    目的:探讨采用1.5%碳酸氢钠溶液联合ESWL治疗尿酸结石的疗效.方法:采用ESWL联合输尿管导管逆行插管后持续灌注1.5%碳酸氢钠溶石治疗1例43岁双肾尿酸结石男性患者.结果:治疗1周后,尿酸结石完全消失,双J管顺利拔出,无逆行感染.结论:1.5%碳酸氢钠溶液联合ESWL治疗尿酸结石疗程短,费用低,疗效确切,是一种治疗尿酸结石快速、安全和有效的治疗方法.%Objective:To investigate the treatment effects of 1. 5% sodium bicarbonate combined with extracorporeal shock wave lithotripsy(ESWL) for renal uric acid stone. Method: A single case of renal uric acid stone was report, a 43-year-old male patients with bilateral renal uric acid stone, and extremity of bilateral double J tube formed uric stone. Patient was treated by ESWL and 1. 5% sodium bicarbonate dissolution therapy. Result: All uric acid stone disappeared without any retrograde infection, bilateral double J tube were extracted successfully after a week. Conclusion:This method is perfect for renal uric acid stone. It might also served as an optimal treat procedure of sodium bicarbonate combined with ESWL for renal uric acid stone.

  15. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to sodium bicarbonate and maintenance of normal blood pressure (ID 1404) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health...... claims in relation to sodium bicarbonate and maintenance of normal blood pressure. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from...

  16. Parameter space of general gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Rajaraman, Arvind [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: arajaram@uci.edu; Shirman, Yuri [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: yshirman@uci.edu; Smidt, Joseph [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: jsmidt@uci.edu; Yu, Felix [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: felixy@uci.edu

    2009-07-27

    We study a subspace of General Gauge Mediation (GGM) models which generalize models of gauge mediation. We find superpartner spectra that are markedly different from those of typical gauge and gaugino mediation scenarios. While typical gauge mediation predictions of either a neutralino or stau next-to-lightest supersymmetric particle (NLSP) are easily reproducible with the GGM parameters, chargino and sneutrino NLSPs are generic for many reasonable choices of GGM parameters.

  17. Notion of Mediators in Human Interaction

    OpenAIRE

    Josip Stepanic

    2003-01-01

    Many types of human interaction are mediated processes. However, regarding the details of human description, the mediating unit structure and dynamics is not developed appropriately. The explicit concentration on mediators contributes to understanding of interplay between value sets governing interaction, interaction roles in regular activities and interaction design for purpose. This article is a contribution to development of a concept of mediated human interaction through structuring of me...

  18. Introduction: Mediating and Remediating Death

    DEFF Research Database (Denmark)

    Christensen, Dorthe Refslund; Sandvik, Kjetil

    2014-01-01

    In this second volume we explore how people, groups and institutions deal with death through processes of mediation (the presentation of something through media), remediation (the representation of one medium in another, see below) and mediatization (the process through which core elements...... of a social or cultural activity assume media form, see below). The volume presents a wide variety of ethnographies of death from Norway, Finland, Sweden, the US, Papua New Guinea, Bosnia and Hercegovina, Libya, Tibet, Uganda and Denmark as well as a number of online sites and social media material....... These are analyzed through a vast number of theoretical and analytical perspectives in order to investigate how very diverse practices surrounding death and dying - mourning and commemoration, ritualization, politicization, re-enactment, traditionalization, activism or documentarism: private or public, offline...

  19. Vernalization-mediated chromatin changes.

    Science.gov (United States)

    Zografos, Brett R; Sung, Sibum

    2012-07-01

    Proper flowering time is vital for reproductive fitness in flowering plants. In Arabidopsis, vernalization is mediated primarily through the repression of a MADS box transcription factor, FLOWERING LOCUS C (FLC). The induction of a plant homeodomain-containing protein, VERNALIZATION INSENSITIVE 3 (VIN3), by vernalizing cold is required for proper repression of FLC. One of a myriad of changes that occurs after VIN3 is induced is the establishment of FLC chromatin at a mitotically repressed state due to the enrichment of repressive histone modifications. VIN3 induction by cold is the earliest known event during the vernalization response and includes changes in histone modifications at its chromatin. Here, the current understanding of the vernalization-mediated chromatin changes in Arabidopsis is discussed, with a focus on the roles of shared chromatin-modifying machineries in regulating VIN3 and FLC gene family expression during the course of vernalization.

  20. On Anomaly Mediated SUSY Breaking

    CERN Document Server

    de Alwis, S P

    2008-01-01

    A discrepancy between the Anomaly Mediated Supersymmetry Breaking (AMSB) gaugino mass calculated from the work of Kaplunovsky and Louis (hep-th/9402005) (KL) and other calculations in the literature is explained, and it is argued that the KL expression is the correct one relevant to the Wilsonian action. Furthermore it is argued that the AMSB contribution to the squark and slepton masses should be replaced by the contribution pointed out by Dine and Seiberg (DS) which has nothing to do with Weyl anomalies. This is not in general equivalent to the AMSB expression, and it is shown that there are models in which the usual AMSB expression would vanish but the DS one is non-zero. In fact the latter has aspects of both AMSB and gauge mediated SUSY breaking. In particular like the latter, it gives positive squared masses for sleptons.

  1. Mediatization: a concept, multiple voices

    Directory of Open Access Journals (Sweden)

    Pedro Gilberto GOMES

    2016-12-01

    Full Text Available Mediatization has become increasingly a key concept, fundamental, essential to describe the present and the history of media and communicative change taking place. Thus, it became part of a whole, one can not see them as a separate sphere. In this perspective, the media coverage is used as a concept to describe the process of expansion of the different technical means and consider the interrelationships between the communicative change, means and sociocultural change. However, although many researchers use the concept of mediatization, each gives you the meaning that best suits your needs. Thus, the concept of media coverage is treated with multiple voices. This paper discusses this problem and present a preliminary pre-position on the matter.

  2. Cell-mediated immune response

    DEFF Research Database (Denmark)

    Meyer, Sonja Izquierdo; Fuglsang, Katrine; Blaakaer, Jan

    2014-01-01

    OBJECTIVE: This clinical review aims to assess the efficacy of human papillomavirus 16/18 (HPV16/18) vaccination on the cell-mediated immune response in women with existing cervical intraepithelial neoplasia or cervical cancer induced by HPV16 or HPV18. DATA SOURCES AND STUDY SELECTION: A focused...... and thorough literature search conducted in five different databases found 996 publications. Six relevant articles were chosen for further review. In total, 154 patients (>18 years of age) were enrolled in prospective study trials with 3-15 months of follow up. The vaccine applications were administered two...... triggered a detectable cell-mediated immune response, some of which were statistically significant. Correlations between immunological response and clinical outcome (histopathology) were not significant, so neoplasms may not be susceptible to vaccine-generated cytotoxic T cells (CD8(+)). CONCLUSIONS...

  3. General Gauge Mediation and Deconstruction

    CERN Document Server

    McGarrie, Moritz

    2010-01-01

    We locate a supersymmetry breaking hidden sector and supersymmetric standard model on different lattice points of an orbifold moose. The hidden sector is encoded in a set of current correlators and the effects of the current correlators are mediated by the lattice site gauge groups with "lattice hopping" functions and through the bifundamental matter that links the lattice sites together. We show how the gaugino mass, scalar mass and Casimir energy of the lattice can be computed for a general set of current correlators and then give specific formulas when the hidden sector is specified to be a generalised messenger sector coupled to a supersymmetry breaking spurion. The results reproduce the effect of five dimensional gauge mediation from a purely four dimensional construction.

  4. Mediational Competencies for Online Education

    Directory of Open Access Journals (Sweden)

    María Elena Chan Núñez

    2005-11-01

    Full Text Available Addressed in the article is a position taken within and in favor of education and virtuality, considering the importance of training constructors of the digital environment. The competencies needed by actors of educational processes, the same which are necessary for their construction, are conceptualized as mediational. Because these are not usually the competencies most visibly when teachers and students are trained for online education, we found it of interest to present part of a research project on this type of competencies. The work starts out from an axiological position on virtual education, the recognition of the way the technologies model educational interactions on line. It follows with the notion of mediation and meditational competency, and comes to a design model that would consider these competencies in the development of learning environments. The article closes with reflections about the interdisciplinary integration necessary for a technological and educational development based on a communicative paradigm.

  5. Methods for Mediation Analysis with Missing Data

    Science.gov (United States)

    Zhang, Zhiyong; Wang, Lijuan

    2013-01-01

    Despite wide applications of both mediation models and missing data techniques, formal discussion of mediation analysis with missing data is still rare. We introduce and compare four approaches to dealing with missing data in mediation analysis including list wise deletion, pairwise deletion, multiple imputation (MI), and a two-stage maximum…

  6. Mediatized Extreme Right Activism and Discourse

    DEFF Research Database (Denmark)

    Peters, Rikke Alberg

    2015-01-01

    and mediatized activism. In order to analyse of the protest form, the visual aesthetics and the discourse of ‘The Immortals’, the paper mobilises two concepts from media and communication studies: mediation and mediatization. It will be argued that that the current transformation of the extreme right: that is...

  7. 7 CFR 900.109 - Mediation agreement.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Mediation agreement. 900.109 Section 900.109 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Mediation agreement. An agreement arrived at by mediation shall not become effective until approved by...

  8. 34 CFR 300.506 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Mediation. 300.506 Section 300.506 Education... DISABILITIES Procedural Safeguards Due Process Procedures for Parents and Children § 300.506 Mediation. (a... due process complaint, to resolve disputes through a mediation process. (b) Requirements....

  9. 45 CFR 617.10 - Mediation.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Mediation. 617.10 Section 617.10 Public Welfare... OF AGE IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE FROM NSF § 617.10 Mediation. (a) NSF will refer to the Federal Mediation and Conciliation Service all complaints that fall...

  10. Causal Mediation Analysis: Warning! Assumptions Ahead

    Science.gov (United States)

    Keele, Luke

    2015-01-01

    In policy evaluations, interest may focus on why a particular treatment works. One tool for understanding why treatments work is causal mediation analysis. In this essay, I focus on the assumptions needed to estimate mediation effects. I show that there is no "gold standard" method for the identification of causal mediation effects. In…

  11. 34 CFR 303.419 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Mediation. 303.419 Section 303.419 Education... DISABILITIES Procedural Safeguards Mediation and Due Process Procedures for Parents and Children § 303.419 Mediation. (a) General. Each State shall ensure that procedures are established and implemented to...

  12. 7 CFR 205.663 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Mediation. 205.663 Section 205.663 Agriculture... PROVISIONS NATIONAL ORGANIC PROGRAM Administrative Compliance § 205.663 Mediation. Any dispute with respect... acceptance by the certifying agent. Mediation shall be requested in writing to the applicable...

  13. 41 CFR 101-8.717 - Mediation.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Mediation. 101-8.717... FINANCIAL ASSISTANCE 8.7-Discrimination Prohibited on the Basis of Age § 101-8.717 Mediation. (a) GSA promptly refers to the mediation agency designated by the Secretary, HHS, all sufficient complaints...

  14. 7 CFR 400.94 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Mediation. 400.94 Section 400.94 Agriculture... AGRICULTURE GENERAL ADMINISTRATIVE REGULATIONS Appeal Procedure § 400.94 Mediation. For adverse decisions only: (a) Appellants have the right to seek mediation or other forms of alternative dispute resolution...

  15. 13 CFR 117.12 - Mediation.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Mediation. 117.12 Section 117.12... Mediation. (a) SBA shall, after ensuring that the complaint falls within the coverage of this Act and all... clearly within an exception, promptly refer the complaint to the Federal Mediation and...

  16. Single-Level and Multilevel Mediation Analysis

    Science.gov (United States)

    Tofighi, Davood; Thoemmes, Felix

    2014-01-01

    Mediation analysis is a statistical approach used to examine how the effect of an independent variable on an outcome is transmitted through an intervening variable (mediator). In this article, we provide a gentle introduction to single-level and multilevel mediation analyses. Using single-level data, we demonstrate an application of structural…

  17. Agents Which Mediate Pulmonary Edema

    Science.gov (United States)

    1990-12-01

    directly the effect of mediators in the lavage on pulmonary vascular endothelium using endothelial cell line methods, as well as isolated perfused lungs...inte;wvention and/or protection from pathological chang6s. 8 1 MATERIALS AND METHODS Bronchoalveolar Lavage: The lavage procedure was performed through...have changed our 14 I technique to the following: 1 ) animals are lightly anesthetized with 30 mg/kg sodium arnytal and a #7.5 - 8 F polyvinyl

  18. Mediating states in 180Ta

    OpenAIRE

    Alexa, Petr

    2002-01-01

    Possible theoretical electromagnetic paths between the ground state and the isomeric state at 75.3 keV in 180Ta are discussed in the framework of the two-quasiparticle-plus-phonon model and the standard axially-symmetric rotor model including Coriolis mixing. Experimental transition rates from the isomeric state to the ground state via observed mediating states are compared to the theoretical ones.

  19. SIRT1-mediated acute cardioprotection

    OpenAIRE

    Nadtochiy, Sergiy M; Yao, Hongwei; McBurney, Michael W.; Gu, Wei; Guarente, Leonard; Rahman, Irfan; Paul S. Brookes

    2011-01-01

    Overexpression studies have revealed a role for silent information regulator of transcription 1 (SIRT1) lysine deacetylase in cardioprotection against ischemia-reperfusion injury via long-term transcriptional effects. However, short-term SIRT1-mediated lysine deacetylation, within the context of acute cardioprotection, is poorly understood. In this study, the role of SIRT1 in the acute cardioprotective paradigm of first window ischemic preconditioning (IPC) was studied using SIRT1-deficient (...

  20. CELLULAR INTERACTIONS MEDIATED BY GLYCONECTIDS

    OpenAIRE

    Popescu, O.; Sumanovski, L. T.; I. Checiu; Elisabeta Popescu; G. N. Misevic

    1999-01-01

    Cellular interactions involve many types of cell surface molecules and operate via homophilic and/or heterophilic protein-protein and protein-carbohydrate binding. Our investigations in different model-systems (marine invertebrates and mammals) have provided direct evidence that a novel class of primordial proteoglycans, named by us gliconectins, can mediate cell adhesion via a new alternative molecular mechanism of polyvalent carbohydrate-carbohydrate binding. Biochemical characterization of...

  1. Substrate mediated enzyme prodrug therapy.

    Directory of Open Access Journals (Sweden)

    Betina Fejerskov

    Full Text Available In this report, we detail Substrate Mediated Enzyme Prodrug Therapy (SMEPT as a novel approach in drug delivery which relies on enzyme-functionalized cell culture substrates to achieve a localized conversion of benign prodrug(s into active therapeutics with subsequent delivery to adhering cells or adjacent tissues. For proof-of-concept SMEPT, we use surface adhered micro-structured physical hydrogels based on poly(vinyl alcohol, β-glucuronidase enzyme and glucuronide prodrugs. We demonstrate enzymatic activity mediated by the assembled hydrogel samples and illustrate arms of control over rate of release of model fluorescent cargo. SMEPT was not impaired by adhering cells and afforded facile time - and dose - dependent uptake of the in situ generated fluorescent cargo by hepatic cells, HepG2. With the use of a glucuronide derivative of an anticancer drug, SN-38, SMEPT afforded a decrease in cell viability to a level similar to that achieved using parent drug. Finally, dose response was achieved using SMEPT and administration of judiciously chosen concentration of SN-38 glucuronide prodrug thus revealing external control over drug delivery using drug eluting surface. We believe that this highly adaptable concept will find use in diverse biomedical applications, specifically surface mediated drug delivery and tissue engineering.

  2. Mediation With Muscle: Understanding When Mediators Commit Resources to Civil War Negotiations

    Science.gov (United States)

    2015-12-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited MEDIATION WITH MUSCLE...UNDERSTANDING WHEN MEDIATORS COMMIT RESOURCES TO CIVIL WAR NEGOTIATIONS by Michael D. Caplan December 2015 Thesis Advisor: T. Camber Warren Second Reader...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE MEDIATION WITH MUSCLE: UNDERSTANDING WHEN MEDIATORS COMMIT RESOURCES TO CIVIL WAR

  3. Construction mediation as a developmental process

    Directory of Open Access Journals (Sweden)

    Julian Sidoli del Ceno

    2013-02-01

    Full Text Available This paper seeks to argue that mediation has been hitherto conceived in the construction industry, and indeed by practitioners in other related disciplines such as property management, as largely a ‘problem-solving’ mechanism. Whilst this is clearly an aim of mediation there is also the appended danger that the value of mediation is conceived in these terms alone. If this is the case, then its value, or success, is conceived very narrowly. The aim of this paper is, then, to argue that there are wider values to mediation in a construction setting. These values can be considered as a ‘family’ of related attitudes, skills and perceptions that can positively affect the persons involved. By affecting growth in individuals an organisational change may follow. This, in turn, can result in a significant cultural change in the industry, and associated professions as a whole, as well as having a positive impact on construction education. The paper begins by an overview of the development of mediation and proceeds to consider its current use of mediation in construction. It then considers the question of how mediation success is conceived. The paper argues that both the current practice of construction mediation and the way in which its success is measured are too narrow. It argues that a wider approach to construction mediation is required. Finally, drawing from the literature on ‘idealist’ mediation an account of mediation as a developmental process is developed.

  4. Mediation et violences conjugales Mediation and Domestic Violence

    Directory of Open Access Journals (Sweden)

    Jacques Faget

    2009-11-01

    Full Text Available Ce travail analyse  les potentialités et les limites du recours à la médiation en matière de régulation des violences conjugales.S’appuyant sur une étude empirique de sa mise en œuvre en France et sur la littérature scientifique existante il révèle l’existence de deux modèles de pratique reflétant deux conceptions de la médiation et plus généralement de l’articulation entre régulations pénales et sociales.This paper analyzes the potential and limits of recourse to mediation for regulating domestic violence. On the basis of an empirical study of its implementation in France and of the existing academic literature, it shows the existence of two types of practices reflecting two conceptions of mediation and more generally, two conceptions of the articulation between social and penal regulation. Full Text

  5. Does bicarbonated mineral water rich in sodium change insulin sensitivity of postmenopausal women? ¿Modifica el agua mineral bicarbonatada rica en sodio la sensibilidad a la insulina de las mujeres postmenopáusicas?

    Directory of Open Access Journals (Sweden)

    S. Schoppen

    2007-10-01

    Full Text Available Aim: To study the effects of drinking 0.5 L of two sodium-rich bicarbonated mineral waters (BMW-1 and 2, with a standard meal, on postprandial insulin and glucose changes. And to determine, if the effects vary depending on insulin resistance, measured by homeostasis model assessment (HOMA. Methods: In a 3-way randomized crossover study, 18 healthy postmenopausal women consumed two sodiumrich BMWs and a low-mineral water (LMW with a standard fat-rich meal. Fasting and postprandial blood samples were taken at 30, 60 and 120 min. Serum glucose, insulin, cholesterol and triacylglycerols were determined. Insulin resistance was estimated by HOMA and insulin sensitivity was calculated by quantitative insulin sensitivity check index (QUICKY. Results: Glucose levels did not change. HOMA and QUICKY values were highly inversely correlated (r = -1,000; p Objetivo: Estudiar los efectos de la ingesta de 0.5L de dos aguas minerales bicarbonatadas ricas en sodio (BMW-1 y 2, junto con una comida estándar, sobre los cambios en la insulina y la glucosa postprandial; y determinar si los posibles efectos varían en función de la resistencia a la insulina evaluada a través del modelo homeostático (HOMA. Métodos: 18 mujeres postmenopáusicas sanas participaron en un estudio triple cruzado aleatorizado, en el que bebieron 2 aguas minerales bicarbonatadas ricas en sodio (BMW-1 y 2 y un agua mineral débil (LMW junto con una comida estándar rica en grasa. Se tomaron muestras de sangre en ayunas y postprandiales a los 30, 60 y 120 min. Se determinó glucosa, insulina, colesterol y triglicéridos en suero. La resistencia a la insulina fue estimada a través del HOMA y la sensibilidad a la insulina se calculó mediante el índice de sensibilidad cuantitativa a la insulina (QUICKY. Resultados: Los niveles de glucosa no presentaron cambios. Los valores de HOMA y QUICKY presentaron una fuerte correlación inversa (r = -1,000; p < 0,0001. Las concentraciones de insulina

  6. 尿素、碳酸氢铵/添加剂同时脱硫脱硝试验研究%Experimental investigation on simultaneous removal of SO2 and NOx by solutions of urea and ammonium bicarbonate/additives

    Institute of Scientific and Technical Information of China (English)

    史占飞; 熊源泉; 谢红银; 张吉超

    2011-01-01

    Experimental research of simultaneous removal of NOx and SO2 with aqueous urea and ammonium bicarbonate/additives solution was carried out in a bubbling reactor, where the effects of two different aqueous ( urea and ammonium bicarbonate) on the NOx removal characteristics were investigated. A series of experimentations were carried out to study the effect of operation parameters,such as liquid level, sorbent composition and SO2 concentration. The results show that liquid level,mass ratio of urea and annonium bicarbonate in mixed solution and SO2 concentration have a significant effect on the removal efficiency of NOx. Two absorbents have the highest denitrification efficiency when liquid level reaches 459 mm. Increasing the proportion of ammonium bicarbonate in multiple solvent is unfavorable to NOx removal. The average denitrification efficiency with solution of 5% urea + 5% ammonium bicarbonate/triethanolamine(0. 015% ) reduces by only 9% compared with 10% urea/triethanolamine(0. 015% ), and the removal efficiencies of NOx and SO2 can still reach 63% and 97% respectively, while the costs of absorbent decrease by nearly 30%. The existence of SO2 has synergistic effect on the absorption of NOx, the sulfite ions play reductive role on NOx which make the denitrification efficiencies of two absorbents increase about 3 %.%在鼓泡反应装置上进行了尿素、碳酸氢铵/三乙醇胺溶液同时脱硫脱硝的试验研究,比较尿素和碳酸氢铵的脱硫脱硝性能,试验分别对液位、吸收剂组成以及SO2体积分数等参数对脱硝效率的影响规律进行了研究.结果表明:液位、吸收液中尿素/碳酸氢铵的比例及SO2入口浓度对NOx的脱除效率均有重要的影响,液位在459 mm时2种吸收液的脱硝效率最高;增加多元溶剂中碳酸氢铵质量浓度不利于NOx的脱除,而5%尿素、5%碳酸氢铵/三乙醇胺(0.015%)多元溶剂的脱硝效率仅比10%的尿素/三乙醇胺(0.015%)

  7. Universality in pure gravity mediation

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Jason L.; Olive, Keith A. [University of Minnesota, William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, Minneapolis, MN (United States); Ibe, Masahiro [University of Tokyo, ICRR, Kashiwa (Japan); University of Tokyo, Kavli IPMU, TODIAS, Kashiwa (Japan); Yanagida, Tsutomu T. [University of Tokyo, Kavli IPMU, TODIAS, Kashiwa (Japan)

    2013-07-15

    If low-energy supersymmetry is realized in nature, the apparent discovery of a Higgs boson with mass around 125 GeV suggests a supersymmetric mass spectrum in the TeV or multi-TeV range. Multi-TeV scalar masses are a necessary component of supersymmetric models with pure gravity mediation or in any model with strong moduli stabilization. Here, we show that full scalar mass universality remains viable as long as the ratio of Higgs vevs, tan{beta}, is relatively small (

  8. Hemichannel-mediated and pH-based feedback from horizontal cells to cones in the vertebrate retina.

    Directory of Open Access Journals (Sweden)

    Iris Fahrenfort

    Full Text Available BACKGROUND: Recent studies designed to identify the mechanism by which retinal horizontal cells communicate with cones have implicated two processes. According to one account, horizontal cell hyperpolarization induces an increase in pH within the synaptic cleft that activates the calcium current (Ca(2+-current in cones, enhancing transmitter release. An alternative account suggests that horizontal cell hyperpolarization increases the Ca(2+-current to promote transmitter release through a hemichannel-mediated ephaptic mechanism. METHODOLOGY/PRINCIPAL FINDINGS: To distinguish between these mechanisms, we interfered with the pH regulating systems in the retina and studied the effects on the feedback responses of cones and horizontal cells. We found that the pH buffers HEPES and Tris partially inhibit feedback responses in cones and horizontal cells and lead to intracellular acidification of neurons. Application of 25 mM acetate, which does not change the extracellular pH buffer capacity, does lead to both intracellular acidification and inhibition of feedback. Because intracellular acidification is known to inhibit hemichannels, the key experiment used to test the pH hypothesis, i.e. increasing the extracellular pH buffer capacity, does not discriminate between a pH-based feedback system and a hemichannel-mediated feedback system. To test the pH hypothesis in a manner independent of artificial pH-buffer systems, we studied the effect of interfering with the endogenous pH buffer, the bicarbonate/carbonic anhydrase system. Inhibition of carbonic anhydrase allowed for large changes in pH in the synaptic cleft of bipolar cell terminals and cone terminals, but the predicted enhancement of the cone feedback responses, according to the pH-hypothesis, was not observed. These experiments thus failed to support a proton mediated feedback mechanism. The alternative hypothesis, the hemichannel-mediated ephaptic feedback mechanism, was therefore studied

  9. Transporter-mediated biofuel secretion.

    Science.gov (United States)

    Doshi, Rupak; Nguyen, Tuan; Chang, Geoffrey

    2013-05-07

    Engineering microorganisms to produce biofuels is currently among the most promising strategies in renewable energy. However, harvesting these organisms for extracting biofuels is energy- and cost-intensive, limiting the commercial feasibility of large-scale production. Here, we demonstrate the use of a class of transport proteins of pharmacological interest to circumvent the need to harvest biomass during biofuel production. We show that membrane-embedded transporters, better known to efflux lipids and drugs, can be used to mediate the secretion of intracellularly synthesized model isoprenoid biofuel compounds to the extracellular milieu. Transporter-mediated biofuel secretion sustainably maintained an approximate three- to fivefold boost in biofuel production in our Escherichia coli test system. Because the transporters used in this study belong to the ubiquitous ATP-binding cassette protein family, we propose their use as "plug-and-play" biofuel-secreting systems in a variety of bacteria, cyanobacteria, diatoms, yeast, and algae used for biofuel production. This investigation showcases the potential of expressing desired membrane transport proteins in cell factories to achieve the export or import of substances of economic, environmental, or therapeutic importance.

  10. Legal and Psychological Aspects of Mediation

    Directory of Open Access Journals (Sweden)

    Dobrokhotova E. N.

    2016-01-01

    Full Text Available The article focuses on gradual innovation of mediation into the practice of social conflict resolution in the light of legal and psychological means of mediation. While mediation is perceived as a conflictological concept and is more widely used in dispute settlement and resolution, a new interdisciplinary field of theoretical knowledge with its own conceptual framework as well as a new professional and practical field are beginning to form both in Russia and in other countries. As theoretical and practical aspects of innovation in mediation require consolidation not only for its national development but also for the guaranteed international cooperation, the article touches upon some of the particular theoretical issues of the topic in question: terminological consistency, consolidation of the system of mediation principles, the phenomenon of juridisation of mediation and its limits.

  11. Integrating Mediators and Moderators in Research Design

    OpenAIRE

    MacKinnon, David P.

    2011-01-01

    The purpose of this article is to describe mediating variables and moderating variables and provide reasons for integrating them in outcome studies. Separate sections describe examples of moderating and mediating variables and the simplest statistical model for investigating each variable. The strengths and limitations of incorporating mediating and moderating variables in a research study are discussed as well as approaches to routinely including these variables in outcome research. The rout...

  12. Focus point supersymmetry in extended gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Ran [School of Physics, Nankai University,Tianjin 300071 (China); Li, Tianjun [State Key Laboratory of Theoretical Physics and Kavli Institute for Theoretical Physics (KITPC),Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Physical Electronics, University of Electronic Science and Technology of China,Chengdu 610054 (China); Staub, Florian [Bethe Center for Theoretical Physics & Physikalisches Institut der Universität Bonn,Nußallee 12, 53115 Bonn (Germany); Zhu, Bin [School of Physics, Nankai University,Tianjin 300071 (China)

    2014-03-27

    We propose a small extension of the minimal gauge mediation through the combination of extended gauge mediation and conformal sequestering. We show that the focus point supersymmetry can be realized naturally, and the fine tuning is significantly reduced compared to the minimal gauge mediation and extended gauge mediation without focus point. The Higgs boson mass is around 125 GeV, the gauginos remain light, and the gluino is likely to be detected at the next run of the LHC. However, the multi-TeV squarks is out of the reach of the LHC. The numerical calculation for fine-tuning shows that this model remains natural.

  13. Parental mediation and cyberbullying - a longitudinal study.

    Science.gov (United States)

    Chng, Grace S; Liau, Albert; Khoo, Angeline; Li, Dongdong

    2014-01-01

    Parents use active and restrictive mediation strategies to guide and regulate children's online participation and the online risks they encounter. However, changes in parental mediation do occur over time and the effectiveness of these strategies on cyberbullying demands for further empirical investigation. The current study addresses these issues with a sample of 1084 students (49% girls) in a longitudinal, three-wave design. Gender differences were tested via multi-group analyses. Longitudinal growth models showed that parental use of both active and restrictive mediation decreased over time. For both types of mediation, the mean rate of change had a significant effect on boys' engagement in cyberbullying, but not for girls. Initial levels of restrictive mediation, but not active mediation, were found to be significantly predictive of cyberbullying in both genders. Girls had higher initial levels of both parental mediation types in comparison to boys. The results reveal that the effectiveness of active and restrictive mediation in relation to students' cyberbullying differs and informs us on gender differences. The implications of these results for parental education in online mediation are discussed.

  14. Phenomenological aspects of mirage mediation

    Energy Technology Data Exchange (ETDEWEB)

    Loewen, Valeri

    2009-07-15

    We consider the possibility that string theory vacua with spontaneously broken supersymmetry and a small positive cosmological constant arise due to hidden sector matter interactions, known as F-uplifting/F-downlifting. We analyze this procedure in a model-independent way in the context of type IIB and heterotic string theory. Our investigation shows that the uplifting/downlifting sector has very important consequences for the resulting phenomenology. Not only does it adjust the vacuum energy, but it can also participate in the process of moduli stabilization. In addition, we find that this sector is the dominant source of supersymmetry breaking. It leads to a hybrid mediation scheme and its signature is a relaxed mirage pattern of the soft supersymmetry breaking terms. The low energy spectra exhibit distinct phenomenological properties and di er from conventional schemes considered so far. (orig.)

  15. Lepton-Flavor Violating Mediators

    CERN Document Server

    Galon, Iftah; Tanedo, Philip

    2016-01-01

    We present a framework where dark matter interacts with the Standard Model through a light, spin-0 mediator that couples chirally to pairs of different-flavor leptons. This flavor violating final state weakens bounds on new physics coupled to leptons from terrestrial experiments and cosmic-ray measurements. As an example, we apply this framework to construct a model for the Fermi-LAT excess of GeV $\\gamma$-rays from the galactic center. We comment on the viability of this portal for self-interacting dark matter explanations of small scale structure anomalies and embeddings in flavor models. Models of this type are shown to be compatible with the muon anomalous magnetic moment anomaly. We review current experimental constraints and identify possible future theoretical and experimental directions.

  16. Palladium-mediated intracellular chemistry

    Science.gov (United States)

    Yusop, Rahimi M.; Unciti-Broceta, Asier; Johansson, Emma M. V.; Sánchez-Martín, Rosario M.; Bradley, Mark

    2011-03-01

    Many important intracellular biochemical reactions are modulated by transition metals, typically in the form of metalloproteins. The ability to carry out selective transformations inside a cell would allow researchers to manipulate or interrogate innumerable biological processes. Here, we show that palladium nanoparticles trapped within polystyrene microspheres can enter cells and mediate a variety of Pd0-catalysed reactions, such as allylcarbamate cleavage and Suzuki-Miyaura cross-coupling. The work provides the basis for the customization of heterogeneous unnatural catalysts as tools to carry out artificial chemistries within cells. Such in cellulo synthesis has potential for a plethora of applications ranging from cellular labelling to synthesis of modulators or inhibitors of cell function.

  17. Protooncogenes as mediators of apoptosis.

    Science.gov (United States)

    Teng, C S

    2000-01-01

    Apoptosis has been well established as a vital biological phenomenon that is important in the maintenance of cellular homeostasis. Three major protooncogene families and their encoded proteins function as mediators of apoptosis in various cell types and are the subject of this chapter. Protooncogenic proteins such as c-Myc/Max, c-Fos/c-Jun, and Bcl-2/Bax utilize a synergetic effect to enhance their roles in the pro- or antiapoptotic action. These family members activate and repress the expression of their target genes, control cell cycle progression, and execute programmed cell death. Repression or overproduction of these protooncogenic proteins induces apoptosis, which may vary as a result of either cell type specificity or the nature of the apoptotic stimuli. The proapoptotic and antiapoptotic proteins exert their effects in the membrane of cellular organelles. Here they generate cell-type-specific signals that activate the caspase family of proteases and their regulators for the execution of apoptosis.

  18. Integrins mediating bone signal transduction

    Institute of Scientific and Technical Information of China (English)

    HE Chuanglong; WANG Yuanliang; YANG Lihua; ZHANG Jun

    2004-01-01

    Integrin-mediated adhesions play critical roles in diverse cell functions. Integrins offers a platform on which mechanical stimuli, cytoskeletal organization, biochemical signals can concentrate. Mechanical stimuli transmitted by integrins influence the cytoskeleton, in turn, the cytoskeleton influences cell adhesion via integrins, then cell adhesion results in a series of signal transduction cascades. In skeleton, integrins also have a key role for bone resoption by osteoclasts and reformation by osteoblasts. In present review, the proteins involved in integrin signal transduction and integrin signal transduction pathways were discussed, mainly on the basic mechanisms of integrin signaling and the roles of integrins in bone signal transduction, which may give insight into new therapeutic agents to all kinds of skeletal diseases and new strategies for bone tissue engineering.

  19. Mediatization Theory and Digital Media

    DEFF Research Database (Denmark)

    Finnemann, Niels Ole

    2011-01-01

    of application.  In Section Two the paper discusses different conceptualizations. It is argued that even if they bring new insights, they cannot be unified into one concept, and that they also lack a consistent definition of digital media. Section three provides a definition of digital media in order to identify...... new trajectories made possible by these media, which have led into a new media matrix built around the internet and mobile devices. It will be argued that the new media matrix cannot be understood from a point of view defined by the framework of 20th century mass media because digital media open new......In the 20th century, the term "media logic" was introduced to denote the influence of independent mass media on political systems and other institutions. In recent years the idea has been reworked and labelled "mediatization" to widen the framework by including new media and new areas...

  20. Gout Decoction Combined with Celebrex and Sodium Bicarbonate Treat Gout Arthritis 32 Cases%痛风方联合西乐葆及碳酸氢钠治疗痛风性关节炎32例疗效观察

    Institute of Scientific and Technical Information of China (English)

    罗琦

    2012-01-01

    [目的]观察自拟痛风方联合西药西乐葆及碳酸氢钠治疗痛风性关节炎的临床疗效.[方法]将2008年10月至2011年10月我院门诊就诊的64例痛风性关节炎患者随机分成2组,对照组32例在基础治疗上口服西乐葆胶囊和碳酸氢钠片;治疗组32例在对照组治疗的基础上,加服自拟痛风方,治疗4周后判定疗效.[结果]治疗组临床痊愈7例,显效12例,有效12例,无效1例,总有效率为96.88%;与对照组总有效率为75.0%比较,差异有统计学意义(P<0.05).[结论]自拟痛风方联合西药西乐葆及碳酸氢钠治疗痛风性关节炎可明显增强疗效,减少痛风复发和西药的副作用.降低血尿酸及血沉水平.%[Objective] To observe the clinical effect of Gout Decoction combined with Celebrex and Sodium Bicarbonate on gout arthritis. [Method] Randomly divide 64 cases into 2 groups; control one takes Celebrex and Sodium Bicarbonate; other group was added with Gout Decoction; observe their effects after 4w. [Result] In treatment group, 7 cases were cured, 12 had marked effect, 12 were effective, 1 failed, total effective rate was 96.88%; while the total effective rate 75.0% for other group, the difference was of statistical meaning. [Conclusion] The self-made Gout Decoction combined with Celebrex and Sodium Bicarbonate can strengthen cure effect, reduce the side effects of western medicine and recurrence of gout, and also decrease UA and ESR.

  1. Forms of Mediation: The Case of Interpreter-Mediated Interactions in Medical Systems

    Science.gov (United States)

    Baraldi, Claudio

    2009-01-01

    This paper analyses the forms of mediation in interlinguistic interactions performed in Italian healthcare services and in contexts of migration. The literature encourages dialogic transformative mediation, empowering participants' voices and changing cultural presuppositions in social systems. It may be doubtful, however, whether mediation can…

  2. Designing business rules for mediation : a process towards agent-mediated business coordination

    NARCIS (Netherlands)

    Zhao, Z.; Dignum, M.V.; Dignum, F.P.M.

    2008-01-01

    Business process integration is a very active research area, in which mediation is one of the fundamental architectural choices. Mediators have difficulties to design mediation services that meet the requirements of the different stakeholders. Business rules play an important role in the decision pr

  3. 饲粮添加碳酸氢钠对蛋鸡生产性能和血液学指标的影响%Effects of Dietary Sodium Bicarbonate on Performance and Hymnological Indices of Laying Hens

    Institute of Scientific and Technical Information of China (English)

    罗爱琼; 杨俊花; 刘丹; 谢晶; 缪德年; 赵志辉

    2013-01-01

    This study was conducted to investigate the effects of dietary NaHCO3 on performance, hematologi-cal indices, serum biochemical parameters and blood gas indices of laying hens, and to identify the safe dose range of sodium bicarbonate (NaHCO3) in the diets of laying hens. Nine hundred 21-week-old Hy-Line brown laying hens were randomly assigned to 5 groups with 6 replicates per group and 30 birds per replicate. Laying hens were fed a basal diet with 0 (control group) , 1, 5, 25 and 50 g/kg NaHCO3 for 10 weeks, respectively. The results showed as follows: the performance of laying hens was not influenced by dietary NaHCO3 supplemental level at ≤5 g/kg (P >0. 05) , but the laying rate, egg mass, feed intake, and average egg weight were significantly reduced (P 0.05). Moreover, the supplementation of NaHCO3 did not affect the number of red blood cells and white blood cells, the activities of alkaline phosphatase, glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase and the concentrations of total protein, albumin, total bilirubin in serum of laying hens (P > 0. 05). However, blood hematocrit and the concentrations of hemoglobin in blood, creatinine and usea nitrogen in serum (P < 0. 05 or P < 0. 01) were markedly increased and the concentration of blood glucose in serum (P <0. 05) was also significantly decreased by the supplementation of 25 to 50 g/kg NaHCO3. Furthermore, the number of platelet in blood of laying hens in 50 g/kg NaHCO3 group was notably lower than that in the other groups (P <0. 05). It is concluded that excessive supplementation of NaHCO3 (≥25 g/kg) can cause the decrease of performance, change of blood gas indices, and disorder of physiological functions of laying hens. However, the supplementation of NaHCO3 at <5 g/kg can support the performance and assistant to maintain hematological levels in the physiological ranges of laying hens. Therefore, it is suggested that the safe dose of NaHCO3 in diets of laying hens should be lower

  4. Interaction intensity and pollinator-mediated selection.

    Science.gov (United States)

    Trunschke, Judith; Sletvold, Nina; Ågren, Jon

    2017-02-27

    In animal-pollinated plants, the opportunity for selection and the strength of pollinator-mediated selection are expected to increase with the degree of pollen limitation. However, whether differences in pollen limitation can explain variation in pollinator-mediated and net selection among animal-pollinated species is poorly understood. In the present study, we quantified pollen limitation, variance in relative fitness and pollinator-mediated selection on five traits important for pollinator attraction (flowering start, plant height, flower number, flower size) and pollination efficiency (spur length) in natural populations of 12 orchid species. Pollinator-mediated selection was quantified by subtracting estimates of selection gradients for plants receiving supplemental hand-pollination from estimates obtained for open-pollinated control plants. Mean pollen limitation ranged from zero to 0.96. Opportunity for selection, pollinator-mediated selection and net selection were all positively related to pollen limitation, whereas nonpollinator-mediated selection was not. Opportunity for selection varied five-fold, strength of pollinator-mediated selection varied three-fold and net selection varied 1.5-fold among species. Supplemental hand-pollination reduced both opportunity for selection and selection on floral traits. The results show that the intensity of biotic interactions is an important determinant of the selection regime, and indicate that the potential for pollinator-mediated selection and divergence in floral traits is particularly high in species that are strongly pollen-limited.

  5. Mediating Social Conflict: A Ford Foundation Report.

    Science.gov (United States)

    Ford Foundation, New York, NY.

    Third-party intervention is increasingly recognized as an effective means of settling social, institutional, community, and interpersonal disputes. Traditionally, mediation efforts have been directed toward conflicts involving labor/management relations. Since the 1960s, however, mediation efforts have also been applied to situations involving…

  6. Semiotic Mediation within an AT Frame

    Science.gov (United States)

    Maracci, Mirko; Mariotti, Maria Alessandra

    2013-01-01

    This article is meant to present a specific elaboration of the notion of mediation in relation to the use of artefacts to enhance mathematics teaching and learning: the elaboration offered by the Theory of Semiotic Mediation. In particular, it provides an explicit model--consistent with the activity-actions-operations framework--of the actions…

  7. Integrating Mediators and Moderators in Research Design

    Science.gov (United States)

    MacKinnon, David P.

    2011-01-01

    The purpose of this article is to describe mediating variables and moderating variables and provide reasons for integrating them in outcome studies. Separate sections describe examples of moderating and mediating variables and the simplest statistical model for investigating each variable. The strengths and limitations of incorporating mediating…

  8. Parent Mediation Empowers Sibling Conflict Resolution

    Science.gov (United States)

    Ross, Hildy S.; Lazinski, Marysia J.

    2014-01-01

    Research Findings: For the current study, formal mediation procedures were adapted for families and parents were trained and asked to mediate their children's disputes; control group parents intervened as they normally would. Conflict negotiations with parents and their children (ages 3½-11 years) occurring 3 and 7 weeks following training, and…

  9. Intercultural Conflict and Mediation: An Intergroup Perspective

    Science.gov (United States)

    Rubenfeld, Sara; Clement, Richard

    2012-01-01

    This study investigates the role of components of intercultural competence in the use of intercultural mediation behaviors. Through the use of the Revised Intercultural Mediation Measure, an instrument revised by the authors, 291 Anglophone and 161 Francophone participants in Canada were asked to indicate their likelihood of employing various…

  10. Sociocultural Theory and the Mediated Learning Experience.

    Science.gov (United States)

    Kozulin, Alex

    2002-01-01

    Discusses the two theories that have contributed most to the development of the mediational approach to learning, Vygotskian sociocultural theory and Feuerstein's theory of Mediated Learning Experience. Both theories emphasize the importance of sociocultural forces in shaping a child's development and learning, and have generated a number of…

  11. Elaborative Retrieval: Do Semantic Mediators Improve Memory?

    Science.gov (United States)

    Lehman, Melissa; Karpicke, Jeffrey D.

    2016-01-01

    The elaborative retrieval account of retrieval-based learning proposes that retrieval enhances retention because the retrieval process produces the generation of semantic mediators that link cues to target information. We tested 2 assumptions that form the basis of this account: that semantic mediators are more likely to be generated during…

  12. A Conceptual Framework for Mediated Environments

    Science.gov (United States)

    Childs, Mark

    2010-01-01

    Background: Immersive virtual worlds are one of a range of different platforms that can be grouped under the concept of mediated environments, i.e. environments that create a metaphorical space in which participants can position themselves and be embodied. Synthesising the literatures concerning the various mediated environment technologies…

  13. On Mediation in Virtual Learning Environments.

    Science.gov (United States)

    Davies, Larry; Hassan, W. Shukry

    2001-01-01

    Discusses concepts of mediation and focuses on the importance of implementing comprehensive virtual learning environments. Topics include education and technology as they relate to cultural change, social institutions, the Internet and computer-mediated communication, software design and human-computer interaction, the use of MOOs, and language.…

  14. The Mediator Role in Social Work Practice.

    Science.gov (United States)

    Parsons, Ruth J.

    1991-01-01

    Notes that mediation as problem-solving intervention in social work became widely used in child custody and divorce cases, child-parent conflicts, and family disputes. Argues that mediator role is inherent in social work, and examines context for and assumptions underlying it. Discusses nature of conflicts, issue of neutrality within social work…

  15. Integrating Mediators and Moderators in Research Design.

    Science.gov (United States)

    Mackinnon, David P

    2011-11-01

    The purpose of this article is to describe mediating variables and moderating variables and provide reasons for integrating them in outcome studies. Separate sections describe examples of moderating and mediating variables and the simplest statistical model for investigating each variable. The strengths and limitations of incorporating mediating and moderating variables in a research study are discussed as well as approaches to routinely including these variables in outcome research. The routine inclusion of mediating and moderating variables holds the promise of increasing the amount of information from outcome studies by generating practical information about interventions as well as testing theory. The primary focus is on mediating and moderating variables for intervention research but many issues apply to nonintervention research as well.

  16. Meta-data based mediator generation

    Energy Technology Data Exchange (ETDEWEB)

    Critchlaw, T

    1998-06-28

    Mediators are a critical component of any data warehouse; they transform data from source formats to the warehouse representation while resolving semantic and syntactic conflicts. The close relationship between mediators and databases requires a mediator to be updated whenever an associated schema is modified. Failure to quickly perform these updates significantly reduces the reliability of the warehouse because queries do not have access to the most current data. This may result in incorrect or misleading responses, and reduce user confidence in the warehouse. Unfortunately, this maintenance may be a significant undertaking if a warehouse integrates several dynamic data sources. This paper describes a meta-data framework, and associated software, designed to automate a significant portion of the mediator generation task and thereby reduce the effort involved in adapting to schema changes. By allowing the DBA to concentrate on identifying the modifications at a high level, instead of reprogramming the mediator, turnaround time is reduced and warehouse reliability is improved.

  17. 制霉菌素联合碳酸氢钠与氟康唑治疗口腔白色念珠菌感染临床疗效比较%Nystatin Combined Treatment of Oral Sodium Bicarbonate and Candida Albicans Fluconazole Clinical Effects of Infection

    Institute of Scientific and Technical Information of China (English)

    邵荣静

    2013-01-01

    目的观察制霉菌素联合碳酸氢钠注射与氟康唑治疗口腔白色念珠菌感染临床疗效比较,为临床治疗口腔念珠菌的感染用药选择提供指导。方法将64例口腔白色念珠菌感染患者随机分为两组,制霉菌素组采用制霉菌素联合碳酸氢钠注射液(2.5%碳酸氢钠溶口腔护理后,制霉菌素研粉口腔内涂沫),氟康唑组采用氟康唑胶囊(100 mg/次,1次/d,午餐后服),5d后比较两组的效果,口腔体征改善的情况。结果制霉菌素组治疗总有效率81.25%,氟康唑组治疗总有效率87.5%,统计学分析显示两组疗效无显著差异。(P>0.05)。结论制霉菌素联合碳酸氢钠注射液与氟康唑治疗口腔白色念珠菌病疗效相近,可以根据患者经济状况、不良反应、患者耐药性等具体情况选择用药。%Objective To observe the combined nystatin and fluconazole treatment of oral sodium bicarbonate injection of Candida albicans clinical ef ects of infection for the clinical treatment of oral Candida infections to guide drug choice. Methods 64 cases of oral Candida albicans infection were randomly divided into two groups, group nystatin were treated with nystatin combined with injection of sodium bicarbonate (2.5%sodium bicarbonate solution after oral care,oral smear powdered nystatin), fluconazole group were treated with fluconazole capsules (each 100 mg,1 day,after lunch service),5 days after the results were compared, signs of improvement in the oral cavity. Results nystatin group total ef ective rate was 81.25%,fluconazole treatment group 87.5%,statistical analysis showed no significant dif erence between two groups. (P>0.05). Conclusion nystatin combined sodium bicarbonate injection and treatment of oral candidiasis fluconazole similar ef icacy,based on economic status of patients,side ef ects,patient specific conditions such as choice of drug resistance drug.

  18. Atomic Force Microscope Mediated Chromatography

    Science.gov (United States)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a

  19. Elder mediation in theory and practice: study results from a national caregiver mediation demonstration project.

    Science.gov (United States)

    Crampton, Alexandra

    2013-01-01

    Mediation is a process through which a third party facilitates discussion among disputing parties to help them identify interests and ideally reach an amicable solution. Elder mediation is a growing subspecialty to address conflicts involving older adults, primarily involving caregiving or finances. Mediation is theorized to empower participants but critics argue that it can exacerbate power imbalances among parties and coerce consensus. These contested claims are examined through study of a national caregiver mediation demonstration project. Study implications underscore the importance of gerontological social work expertise to ensure the empowerment of vulnerable older adults in mediation sessions.

  20. 7 CFR 785.5 - Fees for mediation services.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Fees for mediation services. 785.5 Section 785.5... AGRICULTURE SPECIAL PROGRAMS CERTIFIED STATE MEDIATION PROGRAM § 785.5 Fees for mediation services. A requirement that non-USDA parties who elect to participate in mediation pay a fee for mediation services...