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Sample records for reductive tricarboxylic acid

  1. Origin of the Reductive Tricarboxylic Acid (rTCA Cycle-Type CO2 Fixation: A Perspective

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    Norio Kitadai

    2017-10-01

    Full Text Available The reductive tricarboxylic acid (rTCA cycle is among the most plausible candidates for the first autotrophic metabolism in the earliest life. Extant enzymes fixing CO2 in this cycle contain cofactors at the catalytic centers, but it is unlikely that the protein/cofactor system emerged at once in a prebiotic process. Here, we discuss the feasibility of non-enzymatic cofactor-assisted drive of the rTCA reactions in the primitive Earth environments, particularly focusing on the acetyl-CoA conversion to pyruvate. Based on the energetic and mechanistic aspects of this reaction, we propose that the deep-sea hydrothermal vent environments with active electricity generation in the presence of various sulfide catalysts are a promising setting for it to progress. Our view supports the theory of an autotrophic origin of life from primordial carbon assimilation within a sulfide-rich hydrothermal vent.

  2. Cofactor balance by nicotinamide nucleotide transhydrogenase (NNT) coordinates reductive carboxylation and glucose catabolism in the tricarboxylic acid (TCA) cycle.

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    Gameiro, Paulo A; Laviolette, Laura A; Kelleher, Joanne K; Iliopoulos, Othon; Stephanopoulos, Gregory

    2013-05-03

    Cancer and proliferating cells exhibit an increased demand for glutamine-derived carbons to support anabolic processes. In addition, reductive carboxylation of α-ketoglutarate by isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) was recently shown to be a major source of citrate synthesis from glutamine. The role of NAD(P)H/NAD(P)(+) cofactors in coordinating glucose and glutamine utilization in the tricarboxylic acid (TCA) cycle is not well understood, with the source(s) of NADPH for the reductive carboxylation reaction remaining unexplored. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial enzyme that transfers reducing equivalents from NADH to NADPH. Here, we show that knockdown of NNT inhibits the contribution of glutamine to the TCA cycle and activates glucose catabolism in SkMel5 melanoma cells. The increase in glucose oxidation partially occurred through pyruvate carboxylase and rendered NNT knockdown cells more sensitive to glucose deprivation. Importantly, knocking down NNT inhibits reductive carboxylation in SkMel5 and 786-O renal carcinoma cells. Overexpression of NNT is sufficient to stimulate glutamine oxidation and reductive carboxylation, whereas it inhibits glucose catabolism in the TCA cycle. These observations are supported by an impairment of the NAD(P)H/NAD(P)(+) ratios. Our findings underscore the role of NNT in regulating central carbon metabolism via redox balance, calling for other mechanisms that coordinate substrate preference to maintain a functional TCA cycle.

  3. Cofactor Balance by Nicotinamide Nucleotide Transhydrogenase (NNT) Coordinates Reductive Carboxylation and Glucose Catabolism in the Tricarboxylic Acid (TCA) Cycle*♦

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    Gameiro, Paulo A.; Laviolette, Laura A.; Kelleher, Joanne K.; Iliopoulos, Othon; Stephanopoulos, Gregory

    2013-01-01

    Cancer and proliferating cells exhibit an increased demand for glutamine-derived carbons to support anabolic processes. In addition, reductive carboxylation of α-ketoglutarate by isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) was recently shown to be a major source of citrate synthesis from glutamine. The role of NAD(P)H/NAD(P)+ cofactors in coordinating glucose and glutamine utilization in the tricarboxylic acid (TCA) cycle is not well understood, with the source(s) of NADPH for the reductive carboxylation reaction remaining unexplored. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial enzyme that transfers reducing equivalents from NADH to NADPH. Here, we show that knockdown of NNT inhibits the contribution of glutamine to the TCA cycle and activates glucose catabolism in SkMel5 melanoma cells. The increase in glucose oxidation partially occurred through pyruvate carboxylase and rendered NNT knockdown cells more sensitive to glucose deprivation. Importantly, knocking down NNT inhibits reductive carboxylation in SkMel5 and 786-O renal carcinoma cells. Overexpression of NNT is sufficient to stimulate glutamine oxidation and reductive carboxylation, whereas it inhibits glucose catabolism in the TCA cycle. These observations are supported by an impairment of the NAD(P)H/NAD(P)+ ratios. Our findings underscore the role of NNT in regulating central carbon metabolism via redox balance, calling for other mechanisms that coordinate substrate preference to maintain a functional TCA cycle. PMID:23504317

  4. Oxaloacetate-to-malate conversion by mineral photoelectrochemistry: implications for the viability of the reductive tricarboxylic acid cycle in prebiotic chemistry

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    Guzman, Marcelo I.; Martin, Scot T.

    2008-10-01

    The carboxylic acids produced by the reductive tricarboxylic acid (rTCA) cycle are possibly a biosynthetic core of initial life, although several steps such as the reductive kinetics of oxaloacetate (OAA) to malate (MA) are problematic by conventional chemical routes. In this context, we studied the kinetics of this reaction as promoted by ZnS mineral photoelectrochemistry. The quantum efficiency φMA of MA production from the photoelectrochemical reduction of OAA followed φMA=0.13 [OAA] (2.1×10-3+[OAA])-1 and was independent of temperature (5 to 50°C). To evaluate the importance of this forward rate under a prebiotic scenario, we also studied the temperature-dependent rate of the backward thermal decarboxylation of OAA to pyruvate (PA), which followed an Arrhenius behavior as log (k-2)=11.74 4956/T, where k-2 is in units of s-1. These measured rates were employed in conjunction with the indirectly estimated carboxylation rate of PA to OAA to assess the possible importance of mineral photoelectrochemistry in the conversion of OAA to MA under several scenarios of prebiotic conditions on early Earth. As an example, our analysis shows that there is 90% efficiency with a forward velocity of 3 yr/cycle for the OAA→MA step of the rTCA cycle at 280 K. Efficiency and velocity both decrease for increasing temperature. These results suggest high viability for mineral photoelectrochemistry as an enzyme-free engine to drive the rTCA cycle through the early aeons of early Earth, at least for the investigated OAA→MA step.

  5. Rewiring the reductive tricarboxylic acid pathway and L-malate transport pathway of Aspergillus oryzae for overproduction of L-malate.

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    Liu, Jingjing; Xie, Zhipeng; Shin, Hyun-Dong; Li, Jianghua; Du, Guocheng; Chen, Jian; Liu, Long

    2017-07-10

    Aspergillus oryzae finds wide application in the food, feed, and wine industries, and is an excellent cell factory platform for production of organic acids. In this work, we achieved the overproduction of L-malate by rewiring the reductive tricarboxylic acid (rTCA) pathway and L-malate transport pathway of A. oryzae NRRL 3488. First, overexpression of native pyruvate carboxylase and malate dehydrogenase in the rTCA pathway improved the L-malate titer from 26.1gL -1 to 42.3gL -1 in shake flask culture. Then, the oxaloacetate anaplerotic reaction was constructed by heterologous expression of phosphoenolpyruvate carboxykinase and phosphoenolpyruvate carboxylase from Escherichia coli, increasing the L-malate titer to 58.5gL -1 . Next, the export of L-malate from the cytoplasm to the external medium was strengthened by overexpression of a C4-dicarboxylate transporter gene from A. oryzae and an L-malate permease gene from Schizosaccharomyces pombe, improving the L-malate titer from 58.5gL -1 to 89.5gL -1 . Lastly, guided by transcription analysis of the expression profile of key genes related to L-malate synthesis, the 6-phosphofructokinase encoded by the pfk gene was identified as a potential limiting step for L-malate synthesis. Overexpression of pfk with the strong sodM promoter increased the L-malate titer to 93.2gL -1 . The final engineered A. oryzae strain produced 165gL -1 L-malate with a productivity of 1.38gL -1 h -1 in 3-L fed-batch culture. Overall, we constructed an efficient L-malate producer by rewiring the rTCA pathway and L-malate transport pathway of A. oryzae NRRL 3488, and the engineering strategy adopted here may be useful for the construction of A. oryzae cell factories to produce other organic acids. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Metabolism: Part II. The Tricarboxylic Acid (TCA), Citric Acid, or Krebs Cycle.

    Science.gov (United States)

    Bodner, George M.

    1986-01-01

    Differentiates the tricarboxylic acid (TCA) cycle (or Krebs cycle) from glycolysis, and describes the bridge between the two as being the conversion of pyruvate into acetyl coenzyme A. Discusses the eight steps in the TCA cycle, the results of isotopic labeling experiments, and the net effects of the TCA cycle. (TW)

  7. Characterization of novel di- and tricarboxylic acids in fine tropical aerosols

    Czech Academy of Sciences Publication Activity Database

    Zdráhal, Zbyněk; Vermeylen, R.; Claeys, M.; Maenhaut, W.; Guyon, P.; Artaxo, P.

    2001-01-01

    Roč. 36, č. 4 (2001), s. 403-416 ISSN 1076-5174 Institutional research plan: CEZ:AV0Z4031919 Keywords : dicarboxylic acids * tricarboxylic acids * gas chromatography/mass spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.685, year: 2001

  8. Attachment of di- and tricarboxylic acids to the starting structure of kukersite kerogen

    Energy Technology Data Exchange (ETDEWEB)

    Pobul, L; Mannik, A

    1974-01-01

    Oxidation of the kerogen of kukersite by alkaline permanganate at 50/sup 0/C gave a product containing straight-chain dicarboxylic acids (up to 80%), among which C/sub 4/-C/sub 10/ acids predominated (over 70%). Tricarboxylic acids (15 to 20%) and ..cap alpha..-methyl dicarboxylic acids (4 to 10%) were present. Straight-chain monocarboxylic acids, their isomers, and phenyl derivatives contributed less than 1%. Probably, ..cap alpha..-methyl dicarboxylic and tricarboxylic acids were original structural units of the kerogen. Similar oxidations of Baltic shale indicated that kerogens of different combustible shales differ in chemical composition, but the content of polymers of fatty acids was characteristic. Oxidation of the polymeric acids gave straight-chain mono- and dicarboxylic acids.

  9. Use of triammonium salt of aurin tricarboxylic acid as risk mitigant for aluminum hydride

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    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2017-08-08

    A process and a resulting product by process of an aluminum hydride which is modified with by physically combining in a ball milling process an aluminum hydride with a triammonium salt of aurin tricarboxylic acid. The resulting product is an aluminum hydride which is resistant to air, ambient moisture, and liquid water while maintaining useful hydrogen storage and release kinetics.

  10. Alteration of tricarboxylic acid cycle metabolism in rat brain slices by halothane

    International Nuclear Information System (INIS)

    Cheng, S.C.; Brunner, E.A.

    1978-01-01

    Metabolism of [2- 14 C] pyruvate, [1- 14 C] acetate and [5- 14 C] citrate in rat cerebral cortex slices was studied in the presence of halothane. Metabolites assayed include acetylcholine (ACh), citrate, glutamate, glutamineγ-aminobutyrate (GABA) and aspartate. The trichloroacetic acid soluble extract, the trichloracetic acid insoluble precipitate and its lipid extract were also studied. In control experiments, pyruvate preferentially labelled ACh, citrate, glutamate, GABA and aspartate. Acetate labelled ACh, but to a lesser extent than pyruvate. Acetate also labelled lipids and glutamine. Citrate labelled lipids but not ACh and served as a preferential precursor for glutamine. These data support a three-compartment model for cerebral tricarboxylic acid cycle metabolism. Halothane caused increases in GABA and aspartate contents and a decrease in ACh content. It has no effect on the contents of citrate, glutamate and glutamine. Halothane preferentially inhibited the metabolic transfer of radioactivity from pyruvate into almost all metabolites, an effect probably not related to pyruvate permeability. This is interpreted as halothane depression of the large metabolic compartment which includes the nerve endings. Halothane increased the metabolic transfer of radioactivity from acetate into lipids but did not alter such a transfer into the trichloroacetic acid extract. Halothane increased the metabolic transfer of radioactivity from citrate into the trichloroacetic acid precipitate, lipids and especially glutamine. Transfer of citrate radioactivity into GABA was somewhat decreased. The differential effects of halothane on acetate and citrate utilization suggest that the small metabolic compartment should be subdivided. Therefore, at least three metabolic compartments are demonstrated. Halothane did not interfere with the dicarboxylic acid portion of the tricarboxylic acid cycle. (author)

  11. Genetic Investigation of Tricarboxylic Acid Metabolism during the Plasmodium falciparum Life Cycle

    Directory of Open Access Journals (Sweden)

    Hangjun Ke

    2015-04-01

    Full Text Available New antimalarial drugs are urgently needed to control drug-resistant forms of the malaria parasite Plasmodium falciparum. Mitochondrial electron transport is the target of both existing and new antimalarials. Herein, we describe 11 genetic knockout (KO lines that delete six of the eight mitochondrial tricarboxylic acid (TCA cycle enzymes. Although all TCA KOs grew normally in asexual blood stages, these metabolic deficiencies halted life-cycle progression in later stages. Specifically, aconitase KO parasites arrested as late gametocytes, whereas α-ketoglutarate-dehydrogenase-deficient parasites failed to develop oocysts in the mosquitoes. Mass spectrometry analysis of 13C-isotope-labeled TCA mutant parasites showed that P. falciparum has significant flexibility in TCA metabolism. This flexibility manifested itself through changes in pathway fluxes and through altered exchange of substrates between cytosolic and mitochondrial pools. Our findings suggest that mitochondrial metabolic plasticity is essential for parasite development.

  12. Genetic investigation of tricarboxylic acid metabolism during the Plasmodium falciparum life cycle.

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    Ke, Hangjun; Lewis, Ian A; Morrisey, Joanne M; McLean, Kyle J; Ganesan, Suresh M; Painter, Heather J; Mather, Michael W; Jacobs-Lorena, Marcelo; Llinás, Manuel; Vaidya, Akhil B

    2015-04-07

    New antimalarial drugs are urgently needed to control drug-resistant forms of the malaria parasite Plasmodium falciparum. Mitochondrial electron transport is the target of both existing and new antimalarials. Herein, we describe 11 genetic knockout (KO) lines that delete six of the eight mitochondrial tricarboxylic acid (TCA) cycle enzymes. Although all TCA KOs grew normally in asexual blood stages, these metabolic deficiencies halted life-cycle progression in later stages. Specifically, aconitase KO parasites arrested as late gametocytes, whereas α-ketoglutarate-dehydrogenase-deficient parasites failed to develop oocysts in the mosquitoes. Mass spectrometry analysis of (13)C-isotope-labeled TCA mutant parasites showed that P. falciparum has significant flexibility in TCA metabolism. This flexibility manifested itself through changes in pathway fluxes and through altered exchange of substrates between cytosolic and mitochondrial pools. Our findings suggest that mitochondrial metabolic plasticity is essential for parasite development. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. A Functional Tricarboxylic Acid Cycle Operates during Growth of Bordetella pertussis on Amino Acid Mixtures as Sole Carbon Substrates.

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    Marie Izac

    Full Text Available It has been claimed that citrate synthase, aconitase and isocitrate dehydrogenase activities are non-functional in Bordetella pertussis and that this might explain why this bacterium's growth is sometimes associated with accumulation of polyhydroxybutyrate (PHB and/or free fatty acids. However, the sequenced genome includes the entire citric acid pathway genes. Furthermore, these genes were expressed and the corresponding enzyme activities detected at high levels for the pathway when grown on a defined medium imitating the amino acid content of complex media often used for growth of this pathogenic microorganism. In addition, no significant PHB or fatty acids could be detected. Analysis of the carbon balance and stoichiometric flux analysis based on specific rates of amino acid consumption, and estimated biomass requirements coherent with the observed growth rate, clearly indicate that a fully functional tricarboxylic acid cycle operates in contrast to previous reports.

  14. A plant pathogenic bacterium exploits the tricarboxylic acid cycle metabolic pathway of its insect vector

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    Nehela, Yasser; Hijaz, Faraj; Vincent, Christopher I.

    2018-01-01

    ABSTRACT Huanglongbing in citrus is caused by a phloem-limited, uncultivable, gram-negative α-proteobacterium, Candidatus Liberibacter asiaticus (CLas). CLas is transmitted by the phloem-sucking insect, Diaphorina citri (Hemiptera: Liviidae), in a persistent, circulative, and propagative manner. In this study, we investigated the metabolomic and respiration rates changes in D. citri upon infection with CLas using gas chromatography-mass spectrometry (GC-MS) and gas exchange analysis. The level of glycine, L-serine, L-threonine, and gamma-amino butyric acid were higher in CLas-infected D. citri, while L-proline, L-aspartic acid, and L-pyroglutamic acid were lower in CLas-infected D. citri compared with the control. Citric acid was increased in CLas-infected D. citri, whereas malic and succinic acids were reduced. Interestingly, most of the reduced metabolites such as malate, succinate, aspartate, and L-proline are required for the growth of CLas. The increase in citric acid, serine, and glycine indicated that CLas induced glycolysis and the tricarboxylic acid cycle (TCA) in its vector. In agreement with the GC-MS results, the gene expression results also indicated that glycolysis and TCA were induced in CLas-infected D. citri and this was accompanied with an increases in respiration rate. Phosphoric acid and most of the sugar alcohols were higher in CLas-infected D. citri, indicating a response to the biotic stress or cell damage. Only slight increases in the levels of few sugars were observed in CLas-infected D. citri, which indicated that sugars are tightly regulated by D. citri. Our results indicated that CLas induces nutrient and energetic stress in its host insect. This study may provide some insights into the mechanism of colonization of CLas in its vector. PMID:28594267

  15. Interconnection between tricarboxylic acid cycle and energy generation in microbial fuel cell performed by desulfuromonas acetoxidans IMV B-7384

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    Vasyliv, Oresta M.; Maslovska, Olga D.; Ferensovych, Yaroslav P.; Bilyy, Oleksandr I.; Hnatush, Svitlana O.

    2015-05-01

    Desulfuromonas acetoxidans IMV B-7384 is exoelectrogenic obligate anaerobic sulfur-reducing bacterium. Its one of the first described electrogenic bacterium that performs complete oxidation of an organic substrate with electron transfer directly to the electrode in microbial fuel cell (MFC). This bacterium is very promising for MFC development because of inexpensive cultivation medium, high survival rate and selective resistance to various heavy metal ions. The size of D. acetoxidans IMV B-7384 cells is comparatively small (0.4-0.8×1-2 μm) that is highly beneficial while application of porous anode material because of complete bacterial cover of an electrode area with further significant improvement of the effectiveness of its usage. The interconnection between functioning of reductive stage of tricarboxylic acid (TCA) cycle under anaerobic conditions, and MFC performance was established. Malic, pyruvic, fumaric and succinic acids in concentration 42 mM were separately added into the anode chamber of MFC as the redox agents. Application of malic acid caused the most stabile and the highest power generation in comparison with other investigated organic acids. Its maximum equaled 10.07±0.17mW/m2 on 136 hour of bacterial cultivation. Under addition of pyruvic, succinic and fumaric acids into the anode chamber of MFC the maximal power values equaled 5.80±0.25 mW/m2; 3.2±0.11 mW/m2, and 2.14±0.19 mW/m2 respectively on 40, 56 and 32 hour of bacterial cultivation. Hence the malic acid conversion via reductive stage of TCA cycle is shown to be the most efficient process in terms of electricity generation by D. acetoxidans IMV B-7384 in MFC under anaerobic conditions.

  16. Coulometric bioelectrocatalytic reactions based on NAD-dependent dehydrogenases in tricarboxylic acid cycle

    International Nuclear Information System (INIS)

    Fukuda, Jun; Tsujimura, Seiya; Kano, Kenji

    2008-01-01

    This paper describes the characterization of mediated electro-enzymatic electrolysis systems based on NAD-dependent dehydrogenase reactions in the tricarboxylic acid (TCA) cycle. A micro-bulk electrolysis system with a carbon felt anode immersed in an electrolysis solution with a value of about 10 μL was constructed for coulometric analysis of the substrate oxidation. Diaphorase (DI) was used to couple the NAD-dependent dehydrogenase reaction with the anode reaction of a suitable redox mediator. We focused on three types of NAD-dependant dehydrogenases reactions in this research: (1) isocitrate oxidation, in which the standard Gibbs energy change (ΔG o ') is negative; (2) α-ketoglutarate oxidation, which involves an electrochemically active coenzyme A (CoA); and (3) malate oxidation, which is thermodynamically unfavorable because of a large positive ΔG o ' value. The complete electrolysis of isocitrate was easily achieved, supporting the effective re-oxidation of NADH in the diaphorase-catalyzed electrochemical reaction. CoA was unfavorably oxidized at the electrodes in the presence of some mediators. The electrocatalytic oxidation of CoA was suppressed and the quantitative electrochemical oxidation of α-ketoglutarate was achieved by selecting a suitable mediator with negligibly slow electron transfer kinetics with CoA. The uphill malate oxidation was susceptible to product inhibition in the bioelectrochemical system, although NADH generated in the malate dehydrogenase reaction was immediately oxidized in the electrochemical system. The inhibition was successfully suppressed by linking citrate synthase to quench oxaloacetate and to make the total ΔG o ' value negative

  17. Coulometric bioelectrocatalytic reactions based on NAD-dependent dehydrogenases in tricarboxylic acid cycle

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Jun [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Tsujimura, Seiya [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: seiya@kais.kyoto-u.ac.jp; Kano, Kenji [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: kkano@kais.kyoto-u.ac.jp

    2008-12-30

    This paper describes the characterization of mediated electro-enzymatic electrolysis systems based on NAD-dependent dehydrogenase reactions in the tricarboxylic acid (TCA) cycle. A micro-bulk electrolysis system with a carbon felt anode immersed in an electrolysis solution with a value of about 10 {mu}L was constructed for coulometric analysis of the substrate oxidation. Diaphorase (DI) was used to couple the NAD-dependent dehydrogenase reaction with the anode reaction of a suitable redox mediator. We focused on three types of NAD-dependant dehydrogenases reactions in this research: (1) isocitrate oxidation, in which the standard Gibbs energy change ({delta}G{sup o}') is negative; (2) {alpha}-ketoglutarate oxidation, which involves an electrochemically active coenzyme A (CoA); and (3) malate oxidation, which is thermodynamically unfavorable because of a large positive {delta}G{sup o}' value. The complete electrolysis of isocitrate was easily achieved, supporting the effective re-oxidation of NADH in the diaphorase-catalyzed electrochemical reaction. CoA was unfavorably oxidized at the electrodes in the presence of some mediators. The electrocatalytic oxidation of CoA was suppressed and the quantitative electrochemical oxidation of {alpha}-ketoglutarate was achieved by selecting a suitable mediator with negligibly slow electron transfer kinetics with CoA. The uphill malate oxidation was susceptible to product inhibition in the bioelectrochemical system, although NADH generated in the malate dehydrogenase reaction was immediately oxidized in the electrochemical system. The inhibition was successfully suppressed by linking citrate synthase to quench oxaloacetate and to make the total {delta}G{sup o}' value negative.

  18. The antidiabetic drug metformin decreases mitochondrial respiration and tricarboxylic acid cycle activity in cultured primary rat astrocytes

    DEFF Research Database (Denmark)

    Hohnholt, Michaela C; Blumrich, Eva-Maria; Waagepetersen, Helle S

    2017-01-01

    , and malate, as well as the MCL of the TCA cycle intermediate-derived amino acids glutamate, glutamine, and aspartate. In addition to the total molecular 13 C labeling, analysis of the individual isotopomers of TCA cycle intermediates confirmed a severe decline in labeling and a significant lowering in TCA...... tricarboxylic acid (TCA) cycle metabolism in astrocytes are unknown. We investigated this by mapping 13 C labeling in TCA cycle intermediates and corresponding amino acids after incubation of primary rat astrocytes with [U-13 C]glucose. The presence of metformin did not compromise the viability of cultured...

  19. The tricarboxylic acid cycle activity in cultured primary astrocytes is strongly accelerated by the protein tyrosine kinase inhibitor tyrphostin 23

    DEFF Research Database (Denmark)

    Hohnholt, Michaela C; Blumrich, Eva-Maria; Waagepetersen, Helle S

    2017-01-01

    production. In addition, T23-treatment strongly increased the molecular carbon labeling of the TCA cycle intermediates citrate, succinate, fumarate and malate, and significantly increased the incorporation of (13)C-labelling into the amino acids glutamate, glutamine and aspartate. These results clearly......Tyrphostin 23 (T23) is a well-known inhibitor of protein tyrosine kinases and has been considered as potential anti-cancer drug. T23 was recently reported to acutely stimulate the glycolytic flux in primary cultured astrocytes. To investigate whether T23 also affects the tricarboxylic acid (TCA...

  20. Effect of tricarboxylic acid cycle regulator on carbon retention and organic component transformation during food waste composting.

    Science.gov (United States)

    Lu, Qian; Zhao, Yue; Gao, Xintong; Wu, Junqiu; Zhou, Haixuan; Tang, Pengfei; Wei, Qingbin; Wei, Zimin

    2018-05-01

    Composting is an environment friendly method to recycling organic waste. However, with the increasing concern about greenhouse gases generated in global atmosphere, it is significant to reduce the emission of carbon dioxide (CO 2 ). This study analyzes tricarboxylic acid (TCA) cycle regulators on the effect of reducing CO 2 emission, and the relationship among organic component (OC) degradation and transformation and microorganism during composting. The results showed that adding adenosine tri-phosphate (ATP) and nicotinamide adenine dinucleotide (NADH) could enhance the transformation of OC and increase the diversity of microorganism community. Malonic acid (MA) as a competitive inhibitor could decrease the emission of CO 2 by inhibiting the TCA cycle. A structural equation model was established to explore effects of different OC and microorganism on humic acid (HA) concentration during composting. Furthermore, added MA provided an environmental benefit in reducing the greenhouse gas emission for manufacture sustainable products. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Abnormalities in the tricarboxylic acid (TCA) cycle in the brains of schizophrenia patients.

    Science.gov (United States)

    Bubber, P; Hartounian, V; Gibson, G E; Blass, J P

    2011-03-01

    Images of brain metabolism and measurements of activities of components of the electron transport chain support earlier studies that suggest that brain glucose oxidation is inherently abnormal in a significant proportion of persons with schizophrenia. Therefore, we measured the activities of enzymes of the tricarboxylic (TCA) cycle in dorsolateral-prefrontal-cortex from schizophrenia patients (N=13) and non-psychiatric disease controls (N=13): the pyruvate dehydrogenase complex (PDHC), citrate synthase (CS), aconitase, isocitrate dehydrogenase (ICDH), the alpha-ketoglutarate dehydrogenase complex (KGDHC), succinate thiokinase (STH), succinate dehydrogenase (SDH), fumarase and malate dehydrogenase (MDH). Activities of aconitase (18.4%, pTCA cycle, were lower, but SDH (18.3%, pTCA cycle and cognitive function, age or choline acetyl transferase activity, except for aconitase activity which decreased slightly with age (r=0.55, p=003). The increased activities of dehydrogenases in the second half of the TCA cycle may reflect a compensatory response to reduced activities of enzymes in the first half. Such alterations in the components of TCA cycle are adequate to alter the rate of brain metabolism. These results are consistent with the imaging studies of hypometabolism in schizophrenia. They suggest that deficiencies in mitochondrial enzymes can be associated with mental disease that takes the form of schizophrenia. Copyright © 2010 Elsevier B.V. and ECNP. All rights reserved.

  2. Poly(3-hydroxybutyrate) fuels the tricarboxylic acid cycle and de novo lipid biosynthesis during Bacillus anthracis sporulation.

    Science.gov (United States)

    Sadykov, Marat R; Ahn, Jong-Sam; Widhelm, Todd J; Eckrich, Valerie M; Endres, Jennifer L; Driks, Adam; Rutkowski, Gregory E; Wingerd, Kevin L; Bayles, Kenneth W

    2017-06-01

    Numerous bacteria accumulate poly(3-hydroxybutyrate) (PHB) as an intracellular reservoir of carbon and energy in response to imbalanced nutritional conditions. In Bacillus spp., where PHB biosynthesis precedes the formation of the dormant cell type called the spore (sporulation), the direct link between PHB accumulation and efficiency of sporulation was observed in multiple studies. Although the idea of PHB as an intracellular carbon and energy source fueling sporulation was proposed several decades ago, the mechanisms underlying PHB contribution to sporulation have not been defined. Here, we demonstrate that PHB deficiency impairs Bacillus anthracis sporulation through diminishing the energy status of the cells and by reducing carbon flux into the tricarboxylic acid (TCA) cycle and de novo lipid biosynthesis. Consequently, this metabolic imbalance decreased biosynthesis of the critical components required for spore integrity and resistance, such as dipicolinic acid (DPA) and the spore's inner membrane. Supplementation of the PHB deficient mutant with exogenous fatty acids overcame these sporulation defects, highlighting the importance of the TCA cycle and lipid biosynthesis during sporulation. Combined, the results of this work reveal the molecular mechanisms of PHB contribution to B. anthracis sporulation and provide valuable insight into the metabolic requirements for this developmental process in Bacillus species. © 2017 John Wiley & Sons Ltd.

  3. Spheroid cancer stem cells display reprogrammed metabolism and obtain energy by actively running the tricarboxylic acid (TCA) cycle.

    Science.gov (United States)

    Sato, Masakazu; Kawana, Kei; Adachi, Katsuyuki; Fujimoto, Asaha; Yoshida, Mitsuyo; Nakamura, Hiroe; Nishida, Haruka; Inoue, Tomoko; Taguchi, Ayumi; Takahashi, Juri; Eguchi, Satoko; Yamashita, Aki; Tomio, Kensuke; Wada-Hiraike, Osamu; Oda, Katsutoshi; Nagamatsu, Takeshi; Osuga, Yutaka; Fujii, Tomoyuki

    2016-05-31

    The Warburg effect is a metabolic hallmark of cancer cells; cancer cells, unlike normal cells, exclusively activate glycolysis, even in the presence of enough oxygen. On the other hand, intratumoral heterogeneity is currently of interest in cancer research, including that involving cancer stem cells (CSCs). In the present study, we attempted to gain an understanding of metabolism in CSCs that is distinct from that in non-CSCs. After forming spheroids from the OVTOKO (ovarian clear cell adenocarcinoma) and SiHa (cervical squamous cell carcinoma) cell lines, the metabolites of these cells were compared with the metabolites of cancer cells that were cultured in adherent plates. A principle components analysis clearly divided their metabolic features. Amino acids that participate in tricarboxylic acid (TCA) cycle reactions, such as serine and glutamine, were significantly increased in the spheroids. Indeed, spheroids from each cell line contained more total adenylates than did their corresponding cells in adherent cultures. This study demonstrated that cancer metabolism is not limited to aerobic glycolysis (i.e. the Warburg effect), but is flexible and context-dependent. In addition, activation of TCA cycles was suggested to be a metabolic feature of CSCs that was distinct from non-CSCs. The amino acid metabolic pathways discussed here are already considered as targets for cancer therapy, and they are additionally proposed as potential targets for CSC treatment.

  4. Submolecular regulation of cell transformation by deuterium depleting water exchange reactions in the tricarboxylic acid substrate cycle.

    Science.gov (United States)

    Boros, László G; D'Agostino, Dominic P; Katz, Howard E; Roth, Justine P; Meuillet, Emmanuelle J; Somlyai, Gábor

    2016-02-01

    The naturally occurring isotope of hydrogen ((1)H), deuterium ((2)H), could have an important biological role. Deuterium depleted water delays tumor progression in mice, dogs, cats and humans. Hydratase enzymes of the tricarboxylic acid (TCA) cycle control cell growth and deplete deuterium from redox cofactors, fatty acids and DNA, which undergo hydride ion and hydrogen atom transfer reactions. A model is proposed that emphasizes the terminal complex of mitochondrial electron transport chain reducing molecular oxygen to deuterium depleted water (DDW); this affects gluconeogenesis as well as fatty acid oxidation. In the former, the DDW is thought to diminish the deuteration of sugar-phosphates in the DNA backbone, helping to preserve stability of hydrogen bond networks, possibly protecting against aneuploidy and resisting strand breaks, occurring upon exposure to radiation and certain anticancer chemotherapeutics. DDW is proposed here to link cancer prevention and treatment using natural ketogenic diets, low deuterium drinking water, as well as DDW production as the mitochondrial downstream mechanism of targeted anti-cancer drugs such as Avastin and Glivec. The role of (2)H in biology is a potential missing link to the elusive cancer puzzle seemingly correlated with cancer epidemiology in western populations as a result of excessive (2)H loading from processed carbohydrate intake in place of natural fat consumption. Published by Elsevier Ltd.

  5. Mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation links the tricarboxylic acid (TCA) cycle with methionine metabolism and nuclear DNA methylation.

    Science.gov (United States)

    Lozoya, Oswaldo A; Martinez-Reyes, Inmaculada; Wang, Tianyuan; Grenet, Dagoberto; Bushel, Pierre; Li, Jianying; Chandel, Navdeep; Woychik, Richard P; Santos, Janine H

    2018-04-18

    Mitochondrial function affects many aspects of cellular physiology, and, most recently, its role in epigenetics has been reported. Mechanistically, how mitochondrial function alters DNA methylation patterns in the nucleus remains ill defined. Using a cell culture model of induced mitochondrial DNA (mtDNA) depletion, in this study we show that progressive mitochondrial dysfunction leads to an early transcriptional and metabolic program centered on the metabolism of various amino acids, including those involved in the methionine cycle. We find that this program also increases DNA methylation, which occurs primarily in the genes that are differentially expressed. Maintenance of mitochondrial nicotinamide adenine dinucleotide reduced (NADH) oxidation in the context of mtDNA loss rescues methionine salvage and polyamine synthesis and prevents changes in DNA methylation and gene expression but does not affect serine/folate metabolism or transsulfuration. This work provides a novel mechanistic link between mitochondrial function and epigenetic regulation of gene expression that involves polyamine and methionine metabolism responding to changes in the tricarboxylic acid (TCA) cycle. Given the implications of these findings, future studies across different physiological contexts and in vivo are warranted.

  6. Dynamics and regulation of glycolysis-tricarboxylic acid metabolism in the midgut of Spodoptera litura during metamorphosis.

    Science.gov (United States)

    Hu, D; Luo, W; Fan, L F; Liu, F L; Gu, J; Deng, H M; Zhang, C; Huang, L H; Feng, Q L

    2016-04-01

    Significant changes usually take place in the internal metabolism of insects during metamorphosis. The glycolysis-tricarboxylic acid (glycolysis-TCA) pathway is important for energy metabolism. To elucidate its dynamics, the mRNA levels of genes involved in this pathway were examined in the midgut of Spodoptera litura during metamorphosis, and the pyruvate content was quantified. The expression patterns of these genes in response to starvation were examined, and the interaction between protein phosphatase 1 (PP1) and phosphofructokinase (PFK) was studied. The results revealed that the expression or activities of most glycolytic enzymes was down-regulated in prepupae and then recovered in some degree in pupae, and all TCA-related genes were remarkably suppressed in both the prepupae and pupae. Pyruvate was enriched in the pupal midgut. Taken together, these results suggest that insects decrease both glycolysis and TCA in prepupae to save energy and then up-regulate glycolysis but down-regulate TCA in pupae to increase the supply of intermediates for construction of new organs. The expression of all these genes were down-regulated by starvation, indicating that non-feeding during metamorphosis may be a regulator of glycolysis-TCA pathway in the midgut. Importantly, interaction between PP1 and PFK was identified and is suggested to be involved in the regulation of glycolysis. © 2015 The Royal Entomological Society.

  7. The antidiabetic drug metformin decreases mitochondrial respiration and tricarboxylic acid cycle activity in cultured primary rat astrocytes.

    Science.gov (United States)

    Hohnholt, Michaela C; Blumrich, Eva-Maria; Waagepetersen, Helle S; Dringen, Ralf

    2017-11-01

    Metformin is an antidiabetic drug that is used daily by millions of patients worldwide. Metformin is able to cross the blood-brain barrier and has recently been shown to increase glucose consumption and lactate release in cultured astrocytes. However, potential effects of metformin on mitochondrial tricarboxylic acid (TCA) cycle metabolism in astrocytes are unknown. We investigated this by mapping 13 C labeling in TCA cycle intermediates and corresponding amino acids after incubation of primary rat astrocytes with [U- 13 C]glucose. The presence of metformin did not compromise the viability of cultured astrocytes during 4 hr of incubation, but almost doubled cellular glucose consumption and lactate release. Compared with control cells, the presence of metformin dramatically lowered the molecular 13 C carbon labeling (MCL) of the cellular TCA cycle intermediates citrate, α-ketoglutarate, succinate, fumarate, and malate, as well as the MCL of the TCA cycle intermediate-derived amino acids glutamate, glutamine, and aspartate. In addition to the total molecular 13 C labeling, analysis of the individual isotopomers of TCA cycle intermediates confirmed a severe decline in labeling and a significant lowering in TCA cycling ratio in metformin-treated astrocytes. Finally, the oxygen consumption of mitochondria isolated from metformin-treated astrocytes was drastically reduced in the presence of complex I substrates, but not of complex II substrates. These data demonstrate that exposure to metformin strongly impairs complex I-mediated mitochondrial respiration in astrocytes, which is likely to cause the observed decrease in labeling of mitochondrial TCA cycle intermediates and the stimulation of glycolytic lactate production. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Metabolic regulation at the tricarboxylic acid and glyoxylate cycles of the lignin-degrading basidiomycete Phanerochaete chrysosporium against exogenous addition of vanillin.

    Science.gov (United States)

    Shimizu, Motoyuki; Yuda, Naoki; Nakamura, Tomofumi; Tanaka, Hiroo; Wariishi, Hiroyuki

    2005-10-01

    A proteomic differential display technique was utilized to study cellular responses of Phanerochaete chrysosporium exposed to vanillin, one of the key intermediates found during lignin biodegradation. Intracellular proteins were resolved by 2-DE and target protein spots were identified using MALDI-MS after in-gel tryptic digestions. Upon addition of vanillin to P. chrysosporium, up-regulation of homogentisate 1,2-dioxygenase, 1,4-benzoquinone reductases, aldehyde dehydrogenase, and aryl-alcohol dehydrogenase, which seem to play roles in vanillin metabolism, was observed. Furthermore, enzymes involved in glycolysis, the tricarboxylic acid cycle, the pentose-phosphate cycle, and heme biosynthesis were also activated. Up-regulation of extracellular peroxidase was also observed. One of the most unique phenomena against exogenous vanillin was a switch from the glyoxylate cycle to the tricarboxylic acid cycle, where a drastic increase in isocitrate dehydrogenase activity was observed. The exogenous addition of other aromatic compounds also caused an increase in its activity, which in turn triggered NAD(P)H production via the action of dehydrogenases in the tricarboxylic acid cycle, heme biosynthesis via the action of aminolevulinic acid synthase on succinyl-CoA, and energy production via activation of the mitochondrial electron transfer system. These metabolic shifts seem to be required for activating a metabolic system for aromatic compounds.

  9. Down-regulation of tricarboxylic acid (TCA) cycle genes blocks progression through the first mitotic division in Caenorhabditis elegans embryos.

    Science.gov (United States)

    Rahman, Mohammad M; Rosu, Simona; Joseph-Strauss, Daphna; Cohen-Fix, Orna

    2014-02-18

    The cell cycle is a highly regulated process that enables the accurate transmission of chromosomes to daughter cells. Here we uncover a previously unknown link between the tricarboxylic acid (TCA) cycle and cell cycle progression in the Caenorhabditis elegans early embryo. We found that down-regulation of TCA cycle components, including citrate synthase, malate dehydrogenase, and aconitase, resulted in a one-cell stage arrest before entry into mitosis: pronuclear meeting occurred normally, but nuclear envelope breakdown, centrosome separation, and chromosome condensation did not take place. Mitotic entry is controlled by the cyclin B-cyclin-dependent kinase 1 (Cdk1) complex, and the inhibitory phosphorylation of Cdk1 must be removed in order for the complex to be active. We found that following down-regulation of the TCA cycle, cyclin B levels were normal but CDK-1 remained inhibitory-phosphorylated in one-cell stage-arrested embryos, indicative of a G2-like arrest. Moreover, this was not due to an indirect effect caused by checkpoint activation by DNA damage or replication defects. These observations suggest that CDK-1 activation in the C. elegans one-cell embryo is sensitive to the metabolic state of the cell, and that down-regulation of the TCA cycle prevents the removal of CDK-1 inhibitory phosphorylation. The TCA cycle was previously shown to be necessary for the development of the early embryo in mammals, but the molecular processes affected were not known. Our study demonstrates a link between the TCA cycle and a specific cell cycle transition in the one-cell stage embryo.

  10. Gluconeogenesis is associated with high rates of tricarboxylic acid and pyruvate cycling in fasting northern elephant seals.

    Science.gov (United States)

    Champagne, Cory D; Houser, Dorian S; Fowler, Melinda A; Costa, Daniel P; Crocker, Daniel E

    2012-08-01

    Animals that endure prolonged periods of food deprivation preserve vital organ function by sparing protein from catabolism. Much of this protein sparing is achieved by reducing metabolic rate and suppressing gluconeogenesis while fasting. Northern elephant seals (Mirounga angustirostris) endure prolonged fasts of up to 3 mo at multiple life stages. During these fasts, elephant seals maintain high levels of activity and energy expenditure associated with breeding, reproduction, lactation, and development while maintaining rates of glucose production typical of a postabsorptive mammal. Therefore, we investigated how fasting elephant seals meet the requirements of glucose-dependent tissues while suppressing protein catabolism by measuring the contribution of glycogenolysis, glycerol, and phosphoenolpyruvate (PEP) to endogenous glucose production (EGP) during their natural 2-mo postweaning fast. Additionally, pathway flux rates associated with the tricarboxylic acid (TCA) cycle were measured specifically, flux through phosphoenolpyruvate carboxykinase (PEPCK) and pyruvate cycling. The rate of glucose production decreased during the fast (F(1,13) = 5.7, P = 0.04) but remained similar to that of postabsorptive mammals. The fractional contributions of glycogen, glycerol, and PEP did not change with fasting; PEP was the primary gluconeogenic precursor and accounted for ∼95% of EGP. This large contribution of PEP to glucose production occurred without substantial protein loss. Fluxes through the TCA cycle, PEPCK, and pyruvate cycling were higher than reported in other species and were the most energetically costly component of hepatic carbohydrate metabolism. The active pyruvate recycling fluxes detected in elephant seals may serve to rectify gluconeogeneic PEP production during restricted anaplerotic inflow in these fasting-adapted animals.

  11. PTCA (1H-pyrrole-2,3,5-tricarboxylic acid) as a marker for oxidative hair treatment.

    Science.gov (United States)

    Petzel-Witt, Silvana; Meier, Sylvia I; Schubert-Zsilavecz, Manfred; Toennes, Stefan W

    2018-04-01

    Hair analysis for the assessment of alcohol or drug abstinence has become a routine procedure in forensic toxicology. Hair coloration leading to loss of incorporated xenobiotics and to false negative results has turned out to be a major problem. Currently only colored extracts provide hints of manipulations but not bleaching. A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed and validated to determine 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA), a major oxidation product of melanin. PTCA was determined in natural hair samples (n = 21) after treatment with 3% hydrogen peroxide (H 2 O 2 ) for 30 or 40 minutes with concentrations up to 12% for 40 minutes. In another series, 12 natural hair samples were submitted to different coloration procedures (henna, tinting, semi-permanent and permanent dyeing, bleaching) and the changes in PTCA content were determined. A significant increase in the PTCA content was found for both incubation times and increasing H 2 O 2 concentrations. Coloration with henna or tinting had no influence on PTCA levels detected, but a significant increase was observed after semi-permanent and permanent dyeing and bleaching. As PTCA concentrations in natural hair were found to be in a range of <2.1-16.4 ng/mg (8.4 ± 3.8 ng/mg, mean ± SD, n = 33), a cut-off of 20 ng/mg is recommended for the distinction between natural vs. excessively oxidized hair. In case of naturally low melanin content (light-blond or white hair), no marked increase in PTCA may occur. The present study demonstrated that PTCA is formed during oxidative treatment of melanin in hair, which can be used to detect previous hair coloration including oxidation. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Tricarboxylic acid cycle activity measured by 13C magnetic resonance spectroscopy in rats subjected to the kaolin model of obstructed hydrocephalus

    DEFF Research Database (Denmark)

    Melø, Torun M; Håberg, Asta K; Risa, Øystein

    2011-01-01

    in the amounts of glutamate, alanine and taurine. In addition, the concentration of the neuronal marker N-acetyl aspartate was decreased. (13)C Labelling of most amino acids derived from [1,6-(13)C]glucose was unchanged 2 weeks after hydrocephalus induction. The only indication of astrocyte impairment......Evaluating early changes in cerebral metabolism in hydrocephalus can help in the decision making and the timing of surgical intervention. This study was aimed at examining the tricarboxylic acid (TCA) cycle rate and (13)C label incorporation into neurotransmitter amino acids and other compounds 2...

  13. Localisation of gluconeogenesis and tricarboxylic acid (TCA)-cycle enzymes and first functional analysis of the TCA cycle in Toxoplasma gondii.

    Science.gov (United States)

    Fleige, Tobias; Pfaff, Nils; Gross, Uwe; Bohne, Wolfgang

    2008-08-01

    The apicomplexan parasite Toxoplasma gondii displays some unusual localisations of carbohydrate converting enzymes, which is due to the presence of a vestigial, non-photosynthetic plastid, referred to as the apicoplast. It was recently demonstrated that the single pyruvate dehydrogenase complex (PDH) in T. gondii is exclusively localised inside the apicoplast but absent in the mitochondrion. This raises the question about expression, localisation and function of enzymes for the tricarboxylic acid (TCA)-cycle, which normally depends on PDH generated acetyl-CoA. Based on the expression and localisation of epitope-tagged fusion proteins, we show that all analysed TCA cycle enzymes are localised in the mitochondrion, including both isoforms of malate dehydrogenase. The absence of a cytosolic malate dehydrogenase suggests that a typical malate-aspartate shuttle for transfer of reduction equivalents is missing in T. gondii. We also localised various enzymes which catalyse the irreversible steps in gluconeogenesis to a cellular compartment and examined mRNA expression levels for gluconeogenesis and TCA cycle genes between tachyzoites and in vitro bradyzoites. In order to get functional information on the TCA cycle for the parasite energy metabolism, we created a conditional knock-out mutant for the succinyl-CoA synthetase. Disruption of the sixth step in the TCA cycle should leave the biosynthetic parts of the cycle intact, but prevent FADH2 production. The succinyl-CoA synthetase depletion mutant displayed a 30% reduction in growth rate, which could be restored by supplementation with 2 microM succinate in the tissue culture medium. The mitochondrial membrane potential in these parasites was found to be unaltered. The lack of a more severe phenotype suggests that a functional TCA cycle is not essential for T. gondii replication and for maintenance of the mitochondrial membrane potential.

  14. The cellular and compartmental profile of mouse retinal glycolysis, tricarboxylic acid cycle, oxidative phosphorylation, and ~P transferring kinases.

    Science.gov (United States)

    Rueda, Elda M; Johnson, Jerry E; Giddabasappa, Anand; Swaroop, Anand; Brooks, Matthew J; Sigel, Irena; Chaney, Shawnta Y; Fox, Donald A

    2016-01-01

    The homeostatic regulation of cellular ATP is achieved by the coordinated activity of ATP utilization, synthesis, and buffering. Glucose is the major substrate for ATP synthesis through glycolysis and oxidative phosphorylation (OXPHOS), whereas intermediary metabolism through the tricarboxylic acid (TCA) cycle utilizes non-glucose-derived monocarboxylates, amino acids, and alpha ketoacids to support mitochondrial ATP and GTP synthesis. Cellular ATP is buffered by specialized equilibrium-driven high-energy phosphate (~P) transferring kinases. Our goals were twofold: 1) to characterize the gene expression, protein expression, and activity of key synthesizing and regulating enzymes of energy metabolism in the whole mouse retina, retinal compartments, and/or cells and 2) to provide an integrative analysis of the results related to function. mRNA expression data of energy-related genes were extracted from our whole retinal Affymetrix microarray data. Fixed-frozen retinas from adult C57BL/6N mice were used for immunohistochemistry, laser scanning confocal microscopy, and enzymatic histochemistry. The immunoreactivity levels of well-characterized antibodies, for all major retinal cells and their compartments, were obtained using our established semiquantitative confocal and imaging techniques. Quantitative cytochrome oxidase (COX) and lactate dehydrogenase (LDH) activity was determined histochemically. The Affymetrix data revealed varied gene expression patterns of the ATP synthesizing and regulating enzymes found in the muscle, liver, and brain. Confocal studies showed differential cellular and compartmental distribution of isozymes involved in glucose, glutamate, glutamine, lactate, and creatine metabolism. The pattern and intensity of the antibodies and of the COX and LDH activity showed the high capacity of photoreceptors for aerobic glycolysis and OXPHOS. Competition assays with pyruvate revealed that LDH-5 was localized in the photoreceptor inner segments. The

  15. Metabonomics Indicates Inhibition of Fatty Acid Synthesis, β-Oxidation, and Tricarboxylic Acid Cycle in Triclocarban-Induced Cardiac Metabolic Alterations in Male Mice.

    Science.gov (United States)

    Xie, Wenping; Zhang, Wenpeng; Ren, Juan; Li, Wentao; Zhou, Lili; Cui, Yuan; Chen, Huiming; Yu, Wenlian; Zhuang, Xiaomei; Zhang, Zhenqing; Shen, Guolin; Li, Haishan

    2018-02-14

    Triclocarban (TCC) has been identified as a new environmental pollutant that is potentially hazardous to human health; however, the effects of short-term TCC exposure on cardiac function are not known. The aim of this study was to use metabonomics and molecular biology techniques to systematically elucidate the molecular mechanisms of TCC-induced effects on cardiac function in mice. Our results show that TCC inhibited the uptake, synthesis, and oxidation of fatty acids, suppressed the tricarboxylic acid (TCA) cycle, and increased aerobic glycolysis levels in heart tissue after short-term TCC exposure. TCC also inhibited the nuclear peroxisome proliferator-activated receptor α (PPARα), confirming its inhibitory effects on fatty acid uptake and oxidation. Histopathology and other analyses further confirm that TCC altered mouse cardiac physiology and pathology, ultimately affecting normal cardiac metabolic function. We elucidate the molecular mechanisms of TCC-induced harmful effects on mouse cardiac metabolism and function from a new perspective, using metabonomics and bioinformatics analysis data.

  16. Effects of continuous triiodothyronine infusion on the tricarboxylic acid cycle in the normal immature swine heart under extracorporeal membrane oxygenation in vivo.

    Science.gov (United States)

    Kajimoto, Masaki; Priddy, Colleen M O'Kelly; Ledee, Dolena R; Xu, Chun; Isern, Nancy; Olson, Aaron K; Portman, Michael A

    2014-04-15

    Extracorporeal membrane oxygenation (ECMO) is frequently used in infants with postoperative cardiopulmonary failure. ECMO also suppresses circulating triiodothyronine (T3) levels and modifies myocardial metabolism. We assessed the hypothesis that T3 supplementation reverses ECMO-induced metabolic abnormalities in the immature heart. Twenty-two male Yorkshire pigs (age: 25-38 days) with ECMO received [2-(13)C]lactate, [2,4,6,8-(13)C4]octanoate (medium-chain fatty acid), and [U-(13)C]long-chain fatty acids as metabolic tracers either systemically (totally physiological intracoronary concentration) or directly into the coronary artery (high substrate concentration) for the last 60 min of each protocol. NMR analysis of left ventricular tissue determined the fractional contribution of these substrates to the tricarboxylic acid cycle. Fifty percent of the pigs in each group received intravenous T3 supplement (bolus at 0.6 μg/kg and then continuous infusion at 0.2 μg·kg(-1)·h(-1)) during ECMO. Under both substrate loading conditions, T3 significantly increased the fractional contribution of lactate with a marginal increase in the fractional contribution of octanoate. Both T3 and high substrate provision increased the myocardial energy status, as indexed by phosphocreatine concentration/ATP concentration. In conclusion, T3 supplementation promoted lactate metabolism to the tricarboxylic acid cycle during ECMO, suggesting that T3 releases the inhibition of pyruvate dehydrogenase. Manipulation of substrate utilization by T3 may be used therapeutically during ECMO to improve the resting energy state and facilitate weaning.

  17. Urinary Loss of Tricarboxylic Acid Cycle Intermediates As Revealed by Metabolomics Studies: An Underlying Mechanism to Reduce Lipid Accretion by Whey Protein Ingestion?

    Science.gov (United States)

    2015-01-01

    Whey protein intake is associated with the modulation of energy metabolism and altered body composition both in human subjects and in animals, but the underlying mechanisms are not yet elucidated. We fed obesity-prone C57BL/6J mice high-fat diets with either casein (HF casein) or whey (HF whey) for 6 weeks. At equal energy intake and apparent fat and nitrogen digestibility, mice fed HF whey stored less energy as lipids, evident both as lower white adipose tissue mass and as reduced liver lipids, compared with HF-casein-fed mice. Explorative analyses of 48 h urine, both by 1H NMR and LC–MS metabolomic platforms, demonstrated higher urinary excretion of tricarboxylic acid (TCA) cycle intermediates citric acid and succinic acid (identified by both platforms), and cis-aconitic acid and isocitric acid (identified by LC–MS platform) in the HF whey, relative to in the HF-casein-fed mice. Targeted LC–MS analyses revealed higher citric acid and cis-aconitic acid concentrations in fed state plasma, but not in liver of HF-whey-fed mice. We propose that enhanced urinary loss of TCA cycle metabolites drain available substrates for anabolic processes, such as lipogenesis, thereby leading to reduced lipid accretion in HF-whey-fed compared to HF-casein-fed mice. PMID:24702026

  18. Development of a LC-MS/MS Method for the Simultaneous Detection of Tricarboxylic Acid Cycle Intermediates in a Range of Biological Matrices

    Directory of Open Access Journals (Sweden)

    Omar Al Kadhi

    2017-01-01

    Full Text Available It is now well-established that perturbations in the tricarboxylic acid (TCA cycle play an important role in the metabolic transformation occurring in cancer including that of the prostate. A method for simultaneous qualitative and quantitative analysis of TCA cycle intermediates in body fluids, tissues, and cultured cell lines of human origin was developed using a common C18 reversed-phase column by LC-MS/MS technique. This LC-MS/MS method for profiling TCA cycle intermediates offers significant advantages including simple and fast preparation of a wide range of human biological samples. The analytical method was validated according to the guideline of the Royal Society of Chemistry Analytical Methods Committee. The limits of detection were below 60 nM for most of the TCA intermediates with the exception of lactic and fumaric acids. The calibration curves of all TCA analytes showed linearity with correlation coefficients r2>0.9998. Recoveries were >95% for all TCA analytes. This method was established taking into consideration problems and limitations of existing techniques. We envisage that its application to different biological matrices will facilitate deeper understanding of the metabolic changes in the TCA cycle from in vitro, ex vivo, and in vivo studies.

  19. Metabolomic profiling reveals distinct patterns of tricarboxylic acid disorders in blood stasis syndrome associated with coronary heart disease.

    Science.gov (United States)

    Wang, Yong; Li, Chun; Chang, Hong; Lu, Ling-Hui; Qiu, Qi; Ouyang, Yu-Lin; Yu, Jun-da; Guo, Shu-Zhen; Han, Jing; Wang, Wei

    2016-08-01

    To investigate the underlying metabolomic profifiling of coronary heart disease (CHD) with blood stasis syndrome (BSS). CHD model was induced by a nameroid constrictor in Chinese miniature swine. Fifteen miniature swine were randomly divided into a model group (n=9) and a control group (n=6), respectively according to arandom number table. After 4 weeks, plasma hemorheology was detected by automatic hemorheological analyzer, indices including hematocrit, plasma viscosity, blood viscosity, rigidity index and erythrocyte sedimentation rate; cardiac function was assessed by echocardiograph to detect left ventricular end-systolic diameter (LVED), left ventricular end-diastolic diameter (LVEDd), ejection fraction (EF), fractional shortening (FS) and other indicators. Gas chromatography coupled with mass spectrometry (GC-MS) and bioinformatics were applied to analyze spectra of CHD plasma with BSS. The results of hemorheology analysis showed signifificant changes in viscosity, with low shear whole blood viscosity being lower and plasma viscosity higher in the model group compared with the control group. Moreover, whole blood reduction viscosity at high shear rate and whole blood reduction viscosity at low shear rate increased signifificantly (P patterns involved were associated with dysfunction of energy metabolism including glucose and lipid disorders, especially in glycolysis/gluconeogenesis, galactose metabolism and adenosine-triphosphate-binding cassette transporters. Glucose metabolism and lipid metabolism disorders were the major contributors to the syndrome classifification of CHD with BSS.

  20. Contribution of the tricarboxylic acid (TCA) cycle and the glyoxylate shunt in Saccharomyces cerevisiae to succinic acid production during dough fermentation.

    Science.gov (United States)

    Rezaei, Mohammad N; Aslankoohi, Elham; Verstrepen, Kevin J; Courtin, Christophe M

    2015-07-02

    Succinic acid produced by yeast during bread dough fermentation can significantly affect the rheological properties of the dough. By introducing mutations in the model S288C yeast strain, we show that the oxidative pathway of the TCA cycle and the glyoxylate shunt contribute significantly to succinic acid production during dough fermentation. More specifically, deletion of ACO1 and double deletion of ACO1 and ICL1 resulted in a 36 and 77% decrease in succinic acid levels in fermented dough, respectively. Similarly, double deletion of IDH1 and IDP1 decreased succinic acid production by 85%, while also affecting the fermentation rate. By contrast, double deletion of SDH1 and SDH2 resulted in a two-fold higher succinic acid accumulation compared to the wild-type. Deletion of fumarate reductase activity (FRD1 and OSM1) in the reductive pathway of the TCA cycle did not affect the fermentation rate and succinic acid production. The changes in the levels of succinic acid produced by mutants Δidh1Δidp1 (low level) and Δsdh1Δsdh2 (high level) in fermented dough only resulted in small pH differences, reflecting the buffering capacity of dough at a pH of around 5.1. Moreover, Rheofermentometer analysis using these mutants revealed no difference in maximum dough height and gas retention capacity with the dough prepared with S288C. The impact of the changed succinic acid profile on the organoleptic or antimicrobial properties of bread remains to be demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Comparison of Optimal Thermodynamic Models of the Tricarboxylic Acid Cycle from Heterotrophs, Cyanobacteria, and Green Sulfur Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Dennis G.; Jaramillo Riveri, Sebastian I.; Baxter, Douglas J.; Cannon, William R.

    2014-12-15

    We have applied a new stochastic simulation approach to predict the metabolite levels, energy flow, and material flux in the different oxidative TCA cycles found in E. coli and Synechococcus sp. PCC 7002, and in the reductive TCA cycle typical of chemolithoautotrophs and phototrophic green sulfur bacteria such as Chlorobaculum tepidum. The simulation approach is based on equations of state and employs an assumption similar to that used in transition state theory. The ability to evaluate the thermodynamics of metabolic pathways allows one to understand the relationship between coupling of energy and material gradients in the environment and the selforganization of stable biological systems, and it is shown that each cycle operates in the direction expected due to its environmental niche. The simulations predict changes in metabolite levels and flux in response to changes in cofactor concentrations that would be hard to predict without an elaborate model based on the law of mass action. In fact, we show that a thermodynamically unfavorable reaction can still have flux in the forward direction when it is part of a reaction network. The ability to predict metabolite levels, energy flow and material flux should be significant for understanding the dynamics of natural systems and for understanding principles for engineering organisms for production of specialty chemicals, such as biofuels.

  2. Comparison of Optimal Thermodynamic Models of the Tricarboxylic Acid Cycle from Heterotrophs, Cyanobacteria, and Green Sulfur Bacteria.

    Science.gov (United States)

    Thomas, Dennis G; Jaramillo-Riveri, Sebastian; Baxter, Douglas J; Cannon, William R

    2014-12-26

    We have applied a new stochastic simulation approach to predict the metabolite levels, material flux, and thermodynamic profiles of the oxidative TCA cycles found in E. coli and Synechococcus sp. PCC 7002, and in the reductive TCA cycle typical of chemolithoautotrophs and phototrophic green sulfur bacteria such as Chlorobaculum tepidum. The simulation approach is based on modeling states using statistical thermodynamics and employs an assumption similar to that used in transition state theory. The ability to evaluate the thermodynamics of metabolic pathways allows one to understand the relationship between coupling of energy and material gradients in the environment and the self-organization of stable biological systems, and it is shown that each cycle operates in the direction expected due to its environmental niche. The simulations predict changes in metabolite levels and flux in response to changes in cofactor concentrations that would be hard to predict without an elaborate model based on the law of mass action. In fact, we show that a thermodynamically unfavorable reaction can still have flux in the forward direction when it is part of a reaction network. The ability to predict metabolite levels, energy flow, and material flux should be significant for understanding the dynamics of natural systems and for understanding principles for engineering organisms for production of specialty chemicals.

  3. Anticonvulsant activity of a mGlu(4alpha) receptor selective agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid.

    Science.gov (United States)

    Chapman, A G; Talebi, A; Yip, P K; Meldrum, B S

    2001-07-20

    The metabotropic Group III agonist, (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid (ACPT-1), selective for the mGlu(4alpha) receptor, suppresses sound-induced seizures in DBA/2 mice following its intracerebroventricular (i.c.v.) administration (ED(50) 5.6 [2.9-10.7], nmol i.c.v., 15 min, clonic phase) and in genetically epilepsy-prone (GEP) rats following focal administration into the inferior colliculus (ED(50) 0.08 [0.01-0.50], nmol, 60 min, clonic phase). ACPT-1 also protects against clonic seizures induced in DBA/2 mice by the Group I agonist, (RS)-3,5-dihydroxyphenylglycine (3,5-DHPG) (ED(50) 0.60 [0.29-1.2], nmol i.c.v.) and by the Group III antagonist, (RS)-alpha-methylserine-O-phosphate (MSOP) (ED(50) 49.3 [37.9-64.1], nmol i.c.v.). Another Group III agonist, (RS)-4-phosphonophenyl-glycine (PPG), preferentially activating the mGlu(8) receptor, previously shown to protect against sound-induced seizures in DBA/2 mice and GEP rats, also protects against seizures induced in DBA/2 by 3,5-DHPG (ED(50) 3.7 [2.4-5.7], nmol i.c.v.) and by the Group III antagonist, MSOP (ED(50) 40.2 [21.0-77.0], nmol i.c.v.). At very high doses (500 nmol i.c.v. and above), Group III antagonists have pro-convulsant and convulsant activity. The anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(4) receptor agonist ACPT-1, is partially reversed by the co-administration of the Group III antagonists, MSOP, (RS)-alpha-methyl-4-phosphonophenylglycine (MPPG) or (S)-2-amino-2-methyl-4-phosphonobutanoic acid (MAP4), in the 20-50 nmol dose range. At doses of 50-200 nmol, MPPG and MAP4 cause further reversal of the ACPT-1 anticonvulsant protection, while the MSOP effect on ACPT-1 protection is abolished at higher doses. In contrast, the anticonvulsant protection against sound-induced seizures in DBA/2 mice provided by a fully protective dose (20 nmol, i.c.v.) of the mGlu(8) receptor agonist PPG, is not

  4. Plasma acylcarnitine profiling indicates increased fatty acid oxidation relative to tricarboxylic acid cycle capacity in young, healthy low birth weight men

    DEFF Research Database (Denmark)

    Ribel-Madsen, Amalie; Ribel-Madsen, Rasmus; Brøns, Charlotte

    2016-01-01

    We hypothesized that an increased, incomplete fatty acid beta‐oxidation in mitochondria could be part of the metabolic events leading to insulin resistance and thereby an increased type 2 diabetes risk in low birth weight (LBW) compared with normal birth weight (NBW) individuals. Therefore, we...... measured fasting plasma levels of 45 acylcarnitine species in 18 LBW and 25 NBW men after an isocaloric control diet and a 5‐day high‐fat, high‐calorie diet. We demonstrated that LBW men had higher C2 and C4‐OH levels after the control diet compared with NBW men, indicating an increased fatty acid beta...

  5. FecB, a periplasmic ferric-citrate transporter from E. coli, can bind different forms of ferric-citrate as well as a wide variety of metal-free and metal-loaded tricarboxylic acids.

    Science.gov (United States)

    Banerjee, Sambuddha; Paul, Subrata; Nguyen, Leonard T; Chu, Byron C H; Vogel, Hans J

    2016-01-01

    The Escherichia coli Fec system, consisting of an outer membrane receptor (FecA), a periplasmic substrate binding protein (FecB) and an inner membrane permease-ATPase type transporter (FecC/D), plays an important role in the uptake and transport of Fe(3+)-citrate. Although several FecB sequences from various organisms have been reported, there are no biophysical or structural data available for this protein to date. In this work, using isothermal titration calorimetry (ITC), we report for the first time the ability of FecB to bind different species of Fe(3+)-citrate as well as other citrate complexes with trivalent (Ga(3+), Al(3+), Sc(3+) and In(3+)) and a representative divalent metal ion (Mg(2+)) with low μM affinity. Interestingly, ITC experiments with various iron-free di- and tricarboxylic acids show that FecB can bind tricarboxylates with μM affinity but not biologically relevant dicarboxylates. The ability of FecB to bind with metal-free citrate is also observed in (1)H,(15)N HSQC-NMR titration experiments reported here at two different pH values. Further, differential scanning calorimetry (DSC) experiments indicate that the ligand-bound form of FecB has greater thermal stability than ligand-free FecB under all pH and ligand conditions tested, which is consistent with the idea of domain closure subsequent to ligand binding for this type of periplasmic binding proteins.

  6. In Folio Respiratory Fluxomics Revealed by {sup 13}C Isotopic Labeling and H/D Isotope Effects Highlight the Non-cyclic Nature of the Tricarboxylic Acid 'Cycle' in Illuminated Leaves

    Energy Technology Data Exchange (ETDEWEB)

    Tcherkez, G.; Mahe, A.; Gauthier, P.; Hodges, M. [Institut de Biotechnologie des Plantes, Plateforme Metabolisme-Metabolome IFR87, Batiment 630, Universite Paris-Sud 11, 91405 Orsay cedex (France); Tcherkez, G.; Mauve, C.; Cornic, G. [Laboratoire d' Ecophysiologie Vegetale, Ecologie Systematique Evolution (G.C.), Batiment 630, Universite Paris-Sud 11, 91405 Orsay cedex (France); Gout, E.; Bligny, R. [Laboratoire de Physiologie Cellulaire Vegetale, Commissariat a l' Energie Atomique-Grenoble, 38054 Grenoble cedex 9 (France)

    2009-07-01

    While the possible importance of the tricarboxylic acid (TCA) cycle reactions for leaf photosynthesis operation has been recognized, many uncertainties remain on whether TCA cycle biochemistry is similar in the light compared with the dark. It is widely accepted that leaf day respiration and the metabolic commitment to TCA decarboxylation are down-regulated in illuminated leaves. However, the metabolic basis (i.e. the limiting steps involved in such a down-regulation) is not well known. Here, we investigated the in vivo metabolic fluxes of individual reactions of the TCA cycle by developing two isotopic methods, {sup 13}C tracing and fluxomics and the use of H/D isotope effects, with Xanthium strumarium leaves. We provide evidence that the TCA 'cycle' does not work in the forward direction like a proper cycle but, rather, operates in both the reverse and forward directions to produce fumarate and glutamate, respectively. Such a functional division of the cycle plausibly reflects the compromise between two contrasted forces: (1) the feedback inhibition by NADH and ATP on TCA enzymes in the light, and (2) the need to provide pH-buffering organic acids and carbon skeletons for nitrate absorption and assimilation. (authors)

  7. In Folio Respiratory Fluxomics Revealed by 13C Isotopic Labeling and H/D Isotope Effects Highlight the Non-cyclic Nature of the Tricarboxylic Acid 'Cycle' in Illuminated Leaves

    International Nuclear Information System (INIS)

    Tcherkez, G.; Mahe, A.; Gauthier, P.; Hodges, M.; Tcherkez, G.; Mauve, C.; Cornic, G.; Gout, E.; Bligny, R.

    2009-01-01

    While the possible importance of the tricarboxylic acid (TCA) cycle reactions for leaf photosynthesis operation has been recognized, many uncertainties remain on whether TCA cycle biochemistry is similar in the light compared with the dark. It is widely accepted that leaf day respiration and the metabolic commitment to TCA decarboxylation are down-regulated in illuminated leaves. However, the metabolic basis (i.e. the limiting steps involved in such a down-regulation) is not well known. Here, we investigated the in vivo metabolic fluxes of individual reactions of the TCA cycle by developing two isotopic methods, 13 C tracing and fluxomics and the use of H/D isotope effects, with Xanthium strumarium leaves. We provide evidence that the TCA 'cycle' does not work in the forward direction like a proper cycle but, rather, operates in both the reverse and forward directions to produce fumarate and glutamate, respectively. Such a functional division of the cycle plausibly reflects the compromise between two contrasted forces: (1) the feedback inhibition by NADH and ATP on TCA enzymes in the light, and (2) the need to provide pH-buffering organic acids and carbon skeletons for nitrate absorption and assimilation. (authors)

  8. In Folio Respiratory Fluxomics Revealed by {sup 13}C Isotopic Labeling and H/D Isotope Effects Highlight the Non-cyclic Nature of the Tricarboxylic Acid 'Cycle' in Illuminated Leaves

    Energy Technology Data Exchange (ETDEWEB)

    Tcherkez, G; Mahe, A; Gauthier, P; Hodges, M [Institut de Biotechnologie des Plantes, Plateforme Metabolisme-Metabolome IFR87, Batiment 630, Universite Paris-Sud 11, 91405 Orsay cedex (France); Tcherkez, G; Mauve, C; Cornic, G [Laboratoire d' Ecophysiologie Vegetale, Ecologie Systematique Evolution (G.C.), Batiment 630, Universite Paris-Sud 11, 91405 Orsay cedex (France); Gout, E; Bligny, R [Laboratoire de Physiologie Cellulaire Vegetale, Commissariat a l' Energie Atomique-Grenoble, 38054 Grenoble cedex 9 (France)

    2009-07-01

    While the possible importance of the tricarboxylic acid (TCA) cycle reactions for leaf photosynthesis operation has been recognized, many uncertainties remain on whether TCA cycle biochemistry is similar in the light compared with the dark. It is widely accepted that leaf day respiration and the metabolic commitment to TCA decarboxylation are down-regulated in illuminated leaves. However, the metabolic basis (i.e. the limiting steps involved in such a down-regulation) is not well known. Here, we investigated the in vivo metabolic fluxes of individual reactions of the TCA cycle by developing two isotopic methods, {sup 13}C tracing and fluxomics and the use of H/D isotope effects, with Xanthium strumarium leaves. We provide evidence that the TCA 'cycle' does not work in the forward direction like a proper cycle but, rather, operates in both the reverse and forward directions to produce fumarate and glutamate, respectively. Such a functional division of the cycle plausibly reflects the compromise between two contrasted forces: (1) the feedback inhibition by NADH and ATP on TCA enzymes in the light, and (2) the need to provide pH-buffering organic acids and carbon skeletons for nitrate absorption and assimilation. (authors)

  9. In Folio Respiratory Fluxomics Revealed by 13C Isotopic Labeling and H/D Isotope Effects Highlight the Noncyclic Nature of the Tricarboxylic Acid “Cycle” in Illuminated Leaves1[W

    Science.gov (United States)

    Tcherkez, Guillaume; Mahé, Aline; Gauthier, Paul; Mauve, Caroline; Gout, Elizabeth; Bligny, Richard; Cornic, Gabriel; Hodges, Michael

    2009-01-01

    While the possible importance of the tricarboxylic acid (TCA) cycle reactions for leaf photosynthesis operation has been recognized, many uncertainties remain on whether TCA cycle biochemistry is similar in the light compared with the dark. It is widely accepted that leaf day respiration and the metabolic commitment to TCA decarboxylation are down-regulated in illuminated leaves. However, the metabolic basis (i.e. the limiting steps involved in such a down-regulation) is not well known. Here, we investigated the in vivo metabolic fluxes of individual reactions of the TCA cycle by developing two isotopic methods, 13C tracing and fluxomics and the use of H/D isotope effects, with Xanthium strumarium leaves. We provide evidence that the TCA “cycle” does not work in the forward direction like a proper cycle but, rather, operates in both the reverse and forward directions to produce fumarate and glutamate, respectively. Such a functional division of the cycle plausibly reflects the compromise between two contrasted forces: (1) the feedback inhibition by NADH and ATP on TCA enzymes in the light, and (2) the need to provide pH-buffering organic acids and carbon skeletons for nitrate absorption and assimilation. PMID:19675152

  10. 13C NMR study of effects of fasting and diabetes on the metabolism of pyruvate in the tricarboxylic acid cycle and of the utilization of pyruvate and ethanol in lipogenesis in perfused rat liver

    International Nuclear Information System (INIS)

    Cohen, S.M.

    1987-01-01

    13 C NMR has been used to study the competition of pyruvate dehydrogenase with pyruvate carboxylase for entry of pyruvate into the tricarboxylic acid (TCA) cycle in perfused liver from streptozotocin-diabetic and normal donor rats. The relative proportion of pyruvate entering the TCA cycle by these two routes was estimated from the 13 C enrichments at the individual carbons of glutamate when [3- 13 C]alanine was the only exogenous substrate present. In this way, the proportion of pyruvate entering by the pyruvate dehydrogenase route relative to the pyruvate carboxylase route was determined to be 1:1.2 +/- 0.1 in liver from fed controls, 1:7.7 +/- 2 in liver from 24-fasted controls, and 1:2.6 +/- 0.3 in diabetic liver. Pursuant to this observation that conversion of pyruvate to acetyl coenzyme A (acetyl-CoA) was greatest in perfused liver from fed controls, the incorporation of 13 C label into fatty acids was monitored in this liver preparation. With the exception of the repeating methylene carbons, fatty acyl carbons labeled by [1- 13 C]acetyl-CoA (from [2- 13 C]pyruvate) gave rise to resonances distinguishable on the basis of chemical shift from those observed when label was introduced by [3- 13 C]alanine plus [2- 13 C]ethanol, which are converted to [2- 13 C]acetyl-CoA. Thus, measurement of 13 C enrichment at several specific sites in the fatty acyl chains in time-resolved spectra of perfused liver offers a novel way of monitoring the kinetics of the biosynthesis of fatty acids. In addition to obtaining the rate of lipogenesis, it was possible to distinguish the contributions of chain elongation from those of the de novo synthesis pathway and to estimate the average chain length of the 13 C-labeled fatty acids produced

  11. Crystal structure of [1,1':3',1''-ter-phenyl]-2',3,3''-tri-carb-oxy-lic acid.

    Science.gov (United States)

    Decato, Daniel A; Berryman, Orion B

    2015-09-01

    The asymmetric unit of the title compound, C21H14O6, com-prises two symmetrically independent mol-ecules that form a locally centrosymmetric hydrogen-bonded dimer, with the planes of the corresponding carb-oxy-lic acid groups rotated by 15.8 (1) and 17.5 (1)° relative to those of the adjacent benzene rings. The crystal as a whole, however, exhibits a noncentrosymmetric packing, described by the polar space group Pca21. The dimers form layers along the ab plane, being inter-connected by hydrogen bonds involving the remaining carb-oxy-lic acid groups. The plane of the central carb-oxy-lic acid group forms dihedral angles of 62.5 (1) and 63.0 (1)° with those of the adjacent benzene rings and functions as a hydrogen-bond donor and acceptor. As a donor, it inter-connects adjacent layers, while as an acceptor it stabilizes the packing within the layers. The 'distal' carb-oxy-lic acid groups are nearly coplanar with the planes of the adjacent benzene rings, forming dihedral angles of 1.8 (1) and 7.1 (1)°. These groups also form intra- and inter-layer hydrogen bonds, but with 'reversed' functionality, as compared with the central carb-oxy-lic acid groups.

  12. Crystal structure of [1,1′:3′,1′′-terphenyl]-2′,3,3′′-tricarboxylic acid

    Directory of Open Access Journals (Sweden)

    Daniel A. Decato

    2015-09-01

    Full Text Available The asymmetric unit of the title compound, C21H14O6, comprises two symmetrically independent molecules that form a locally centrosymmetric hydrogen-bonded dimer, with the planes of the corresponding carboxylic acid groups rotated by 15.8 (1 and 17.5 (1° relative to those of the adjacent benzene rings. The crystal as a whole, however, exhibits a noncentrosymmetric packing, described by the polar space group Pca21. The dimers form layers along the ab plane, being interconnected by hydrogen bonds involving the remaining carboxylic acid groups. The plane of the central carboxylic acid group forms dihedral angles of 62.5 (1 and 63.0 (1° with those of the adjacent benzene rings and functions as a hydrogen-bond donor and acceptor. As a donor, it interconnects adjacent layers, while as an acceptor it stabilizes the packing within the layers. The `distal' carboxylic acid groups are nearly coplanar with the planes of the adjacent benzene rings, forming dihedral angles of 1.8 (1 and 7.1 (1°. These groups also form intra- and inter-layer hydrogen bonds, but with `reversed' functionality, as compared with the central carboxylic acid groups.

  13. Isotopomer profiling of Leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth.

    Science.gov (United States)

    Saunders, Eleanor C; Ng, William W; Chambers, Jennifer M; Ng, Milica; Naderer, Thomas; Krömer, Jens O; Likic, Vladimir A; McConville, Malcolm J

    2011-08-05

    Leishmania parasites proliferate within nutritionally complex niches in their sandfly vector and mammalian hosts. However, the extent to which these parasites utilize different carbon sources remains poorly defined. In this study, we have followed the incorporation of various (13)C-labeled carbon sources into the intracellular and secreted metabolites of Leishmania mexicana promastigotes using gas chromatography-mass spectrometry and (13)C NMR. [U-(13)C]Glucose was rapidly incorporated into intermediates in glycolysis, the pentose phosphate pathway, and the cytoplasmic carbohydrate reserve material, mannogen. Enzymes involved in the upper glycolytic pathway are sequestered within glycosomes, and the ATP and NAD(+) consumed by these reactions were primarily regenerated by the fermentation of phosphoenolpyruvate to succinate (glycosomal succinate fermentation). The initiating enzyme in this pathway, phosphoenolpyruvate carboxykinase, was exclusively localized to the glycosome. Although some of the glycosomal succinate was secreted, most of the C4 dicarboxylic acids generated during succinate fermentation were further catabolized in the TCA cycle. A high rate of TCA cycle anaplerosis was further suggested by measurement of [U-(13)C]aspartate and [U-(13)C]alanine uptake and catabolism. TCA cycle anaplerosis is apparently needed to sustain glutamate production under standard culture conditions. Specifically, inhibition of mitochondrial aconitase with sodium fluoroacetate resulted in the rapid depletion of intracellular glutamate pools and growth arrest. Addition of high concentrations of exogenous glutamate alleviated this growth arrest. These findings suggest that glycosomal and mitochondrial metabolism in Leishmania promastigotes is tightly coupled and that, in contrast to the situation in some other trypanosomatid parasites, the TCA cycle has crucial anabolic functions.

  14. Integration of the tricarboxylic acid (TCA cycle with cAMP signaling and Sfl2 pathways in the regulation of CO2 sensing and hyphal development in Candida albicans.

    Directory of Open Access Journals (Sweden)

    Li Tao

    2017-08-01

    Full Text Available Morphological transitions and metabolic regulation are critical for the human fungal pathogen Candida albicans to adapt to the changing host environment. In this study, we generated a library of central metabolic pathway mutants in the tricarboxylic acid (TCA cycle, and investigated the functional consequences of these gene deletions on C. albicans biology. Inactivation of the TCA cycle impairs the ability of C. albicans to utilize non-fermentable carbon sources and dramatically attenuates cell growth rates under several culture conditions. By integrating the Ras1-cAMP signaling pathway and the heat shock factor-type transcription regulator Sfl2, we found that the TCA cycle plays fundamental roles in the regulation of CO2 sensing and hyphal development. The TCA cycle and cAMP signaling pathways coordinately regulate hyphal growth through the molecular linkers ATP and CO2. Inactivation of the TCA cycle leads to lowered intracellular ATP and cAMP levels and thus affects the activation of the Ras1-regulated cAMP signaling pathway. In turn, the Ras1-cAMP signaling pathway controls the TCA cycle through both Efg1- and Sfl2-mediated transcriptional regulation in response to elevated CO2 levels. The protein kinase A (PKA catalytic subunit Tpk1, but not Tpk2, may play a major role in this regulation. Sfl2 specifically binds to several TCA cycle and hypha-associated genes under high CO2 conditions. Global transcriptional profiling experiments indicate that Sfl2 is indeed required for the gene expression changes occurring in response to these elevated CO2 levels. Our study reveals the regulatory role of the TCA cycle in CO2 sensing and hyphal development and establishes a novel link between the TCA cycle and Ras1-cAMP signaling pathways.

  15. Integration of the tricarboxylic acid (TCA) cycle with cAMP signaling and Sfl2 pathways in the regulation of CO2 sensing and hyphal development in Candida albicans.

    Science.gov (United States)

    Tao, Li; Zhang, Yulong; Fan, Shuru; Nobile, Clarissa J; Guan, Guobo; Huang, Guanghua

    2017-08-01

    Morphological transitions and metabolic regulation are critical for the human fungal pathogen Candida albicans to adapt to the changing host environment. In this study, we generated a library of central metabolic pathway mutants in the tricarboxylic acid (TCA) cycle, and investigated the functional consequences of these gene deletions on C. albicans biology. Inactivation of the TCA cycle impairs the ability of C. albicans to utilize non-fermentable carbon sources and dramatically attenuates cell growth rates under several culture conditions. By integrating the Ras1-cAMP signaling pathway and the heat shock factor-type transcription regulator Sfl2, we found that the TCA cycle plays fundamental roles in the regulation of CO2 sensing and hyphal development. The TCA cycle and cAMP signaling pathways coordinately regulate hyphal growth through the molecular linkers ATP and CO2. Inactivation of the TCA cycle leads to lowered intracellular ATP and cAMP levels and thus affects the activation of the Ras1-regulated cAMP signaling pathway. In turn, the Ras1-cAMP signaling pathway controls the TCA cycle through both Efg1- and Sfl2-mediated transcriptional regulation in response to elevated CO2 levels. The protein kinase A (PKA) catalytic subunit Tpk1, but not Tpk2, may play a major role in this regulation. Sfl2 specifically binds to several TCA cycle and hypha-associated genes under high CO2 conditions. Global transcriptional profiling experiments indicate that Sfl2 is indeed required for the gene expression changes occurring in response to these elevated CO2 levels. Our study reveals the regulatory role of the TCA cycle in CO2 sensing and hyphal development and establishes a novel link between the TCA cycle and Ras1-cAMP signaling pathways.

  16. ARUM -- Acid reduction using microbiology

    International Nuclear Information System (INIS)

    Kalin, M.; Fyson, A.; Smith, M.P.

    1993-01-01

    The main objective of the ARUM process is to optimize this mineralization in sediments created in mining waste management areas. The most important parameter driving ARUM (or the remineralization process) is the flux of organic carbon from the water column to the microbial communities in the sediment. Various organic materials have been tested as sources of carbon for ARUM in AMD from base metal and coal operations. Carbon availability from materials such as peat, sawdust or Typha leaves depends on decomposition which is extremely limited in acidic, anoxic conditions where ARUM can occur. Weight loss from decomposition bags and sequential nutritional analysis were used to assess decomposition of test organic materials after prolonged exposure (up to two years) in AMD in ponds, lake enclosures (limnocorrals) or constructed ARUM test cells. The results indicate that decomposition can occur in the reducing conditions associated with ARUM and that of all the materials tested, peat is the most promising and sawdust the least promising ARUM substrate

  17. A two-dimensional ZnII coordination polymer constructed from benzene-1,2,3-tricarboxylic acid and N,N'-bis[(pyridin-4-yl)methylidene]hydrazine.

    Science.gov (United States)

    Wang, Xiangfei; Yang, Fang; Tang, Meng; Yuan, Limin; Liu, Wenlong

    2015-07-01

    The hydrothermal synthesis of the novel complex poly[aqua(μ4-benzene-1,2,3-tricarboxylato)[μ2-4,4'-(hydrazine-1,2-diylidenedimethanylylidene)dipyridine](μ3-hydroxido)dizinc(II)], [Zn(C9H3O6)(OH)(C12H10N4)(H2O)]n, is described. The benzene-1,2,3-tricarboxylate ligand connects neighbouring Zn4(OH)2 secondary building units (SBUs) producing an infinite one-dimensional chain. Adjacent one-dimensional chains are connected by the N,N'-bis[(pyridin-4-yl)methylidene]hydrazine ligand, forming a two-dimensional layered structure. Adjacent layers are stacked to generate a three-dimensional supramolecular architecture via O-H...O hydrogen-bond interactions. The thermal stability of this complex is described and the complex also appears to have potential for application as a luminescent material.

  18. No reduction using sublimination of cyanuric acid

    Science.gov (United States)

    Perry, Robert A.

    1996-01-01

    A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of cyanuric acid, said amount and temperature being effective for the resultant lowering of the NO content of the gas stream, said cyanuric acid being particulate and having a particle size of less than 90 .mu.m.

  19. NO reduction using sublimation of cyanuric acid

    Science.gov (United States)

    Perry, R.A.

    1996-05-21

    A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of cyanuric acid, said amount and temperature being effective for the resultant lowering of the NO content of the gas stream, said cyanuric acid being particulate and having a particle size of less than 90 {micro}m. 1 fig.

  20. Waste volume reduction by acid digestion

    International Nuclear Information System (INIS)

    Lerch, R.E.; Divine, J.R.

    1975-06-01

    Acid digestion is a process being developed at the Hanford Engineering Development Laboratory (HEDL) in Richland, Washington, to reduce the volume of alpha-contaminated combustible waste by converting it into a non-combustible residue. Typical waste materials such as polyvinylchloride (PVC), polyethylene, paper and other cellulosic materials, ion exchange resin, all types of rubber, etc., are digested in hot (230 0 C--270 0 C) concentrated sulfuric acid containing nitric acid oxidant to form inert residues generally having less than four percent of their original volume and less than twenty-five percent of their original mass. The process is currently being tested using non-radioactive waste in an Acid Digestion Test Unit (ADTU) with all glass equipment. Engineering tests to date have shown acid digestion to be a potentially attractive method for treating combustible waste materials. Based on results of the engineering tests, an acid digestion pilot unit capable of treating radioactive wastes is being designed and constructed. Design capacity of the pilot unit for radioactive waste will be 100 kg of waste per day. (U.S.)

  1. Coupling of subcritical methanol with acidic ionic liquids for the acidity reduction of naphthenic acids

    Directory of Open Access Journals (Sweden)

    Zafar Faisal

    2017-09-01

    Full Text Available The presence of naphthenic acids (NAs in crude oil is the major cause of corrosion in the refineries and its processing equipment. The goal of this study is to reduce the total acid number (TAN of NAs by treating them with subcritical methanol in the presence of acidic ionic liquid (AIL catalysts. Experiments were carried out in an autoclave batch reactor and the effect of different reaction parameters was investigated. It was observed that TAN reduction was positively dependent on the temperature and concentration of the AIL whereas excess of methanol has a negative effect. Approximately 90% TAN reduction was achieved under the optimized reaction conditions using [BMIM]HSO4 as catalyst. It was also perceived from the experimental results that the AILs with longer alkyl chain exhibited higher catalytic activity. The activity and stability of AIL showed that they can be promising catalyst to esterify NAs under subcritical methanol.

  2. Green reduction of graphene oxide by ascorbic acid

    Science.gov (United States)

    Khosroshahi, Zahra; Kharaziha, Mahshid; Karimzadeh, Fathallah; Allafchian, Alireza

    2018-01-01

    Graphene, a single layer of sp2-hybridized carbon atoms in a hexagonal (two-dimensional honey-comb) lattice, has attracted strong scientific and technological interest due to its novel and excellent optical, chemical, electrical, mechanical and thermal properties. The solution-processable chemical reduction of Graphene oxide (GO is considered as the most favorable method regarding mass production of graphene. Generally, the reduction of GO is carried out by chemical approaches using different reductants such as hydrazine and sodium borohydride. These components are corrosive, combustible and highly toxic which may be dangerous for personnel health and the environment. Hence, these reducing agents are not promising choice for reducing of graphene oxide (GO). As a consequence, it is necessary for further development and optimization of eco-friendly, natural reducing agent for clean and effective reduction of GO. Ascorbic acid, an eco-friendly and natural reducing agents, having a mild reductive ability and nontoxic property. So, the aim of this research was to green synthesis of GO with ascorbic acid. For this purpose, the required amount of NaOH and ascorbic acid were added to GO solution (0.5 mg/ml) and were heated at 95 °C for 1 hour. According to the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and electrochemical results, GO were reduced with ascorbic acid like hydrazine with better electrochemical properties and ascorbic acid is an ideal substitute for hydrazine in the reduction of graphene oxide process.

  3. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  4. Effect of reaction products on cathodic reduction of iodic acid

    International Nuclear Information System (INIS)

    Shtejnberg, G.V.; Urisson, N.A.; Revina, A.A.; Volod'ko, V.L.

    1988-01-01

    The effect of reaction products on kinetics of iodic acid reduction is investigated; reaction products are identified by the optical method. It is shown that although being similar from the qualitative viewpoint the effect on HIO 3 reduction of dissolved crystal and ''reduced'' iodine, certain quantitative differences take place, which are explained by the difference in their surface concentration. Explanation of certain sections of complex lgI, E-curve of HIO 3 reduction is given, in particular, advanced wave is related to the reduction from solution of unstable electroactive complex HIO 3 ) x (I 1 ) y or (HIO 3 ) x (I 2 ) y

  5. Mechanism of nitric acid reduction and kinetic modelling

    International Nuclear Information System (INIS)

    Sicsic, David; Balbaud-Celerier, Fanny; Tribollet, Bernard

    2014-01-01

    In France, the recycling of nuclear waste fuels involves the use of hot concentrated nitric acid. The understanding and prediction of the behaviour of the structural materials (mainly austenitic stainless steels) requires the determination and modelling of the nitric acid reduction process. Nitric acid is indirectly reduced by an autocatalytic mechanism depending on the cathodic overpotential and acid concentration. This mechanism has been widely studied. All the authors agree on its autocatalytic nature, characterized by the predominant role of the reduction products. It is also generally admitted that neither nitric acid nor the nitrate ion is the electro-active species. However, the nature of the electro-active species, the place where the catalytic species regenerates and the thermodynamic and kinetic behaviour of the reaction intermediates remain uncertain. The aim of this study was to clarify some of these uncertainties by performing an electrochemical investigation of the reduction of 4 M nitric acid at 40 C at an inert electrode (platinum or gold). An inert electrode was chosen as the working electrode in a first step to avoid its oxidation and focus the research on the reduction mechanism. This experimental work enabled us to suggest a coherent sequence of electrochemical and chemical reactions. Kinetic modelling of this sequence was then carried out for a gold rotating disk electrode. A thermodynamic study at 25 C allowed the composition of the liquid and gaseous phases of nitric acid solutions in the concentration range 0.5-22 M to be evaluated. The kinetics of the reduction of 4 M nitric acid was investigated by cyclic voltammetry and chrono-amperometry at an inert electrode at 40 C. The coupling of chrono-amperometry and FTIR spectroscopy in the gaseous phase led to the identification of the gaseous reduction products as a function of the cathodic overpotential. The results showed that the reduction process is autocatalytic for potentials between 0

  6. 40 CFR 747.200 - Triethanolamine salt of tricarboxylic acid.

    Science.gov (United States)

    2010-07-01

    ... import for commercial purposes, manufacture solely for export, manufacturer, new chemical substance... (—NO) to a secondary or tertiary amine to form the corresponding nitrosamine. (c) Use limitations. (1) Any person producing a metalworking fluid, or a product which could be used in or as a metalworking...

  7. Significant thermal energy reduction in lactic acid production process

    International Nuclear Information System (INIS)

    Mujtaba, Iqbal M.; Edreder, Elmahboub A.; Emtir, Mansour

    2012-01-01

    Lactic acid is widely used as a raw material for the production of biodegradable polymers and in food, chemical and pharmaceutical industries. The global market for lactic acid is expected to reach 259 thousand metric tons by the year 2012. For batch production of lactic acid, the traditional process includes the following steps: (i) esterification of impure lactic acid with methanol in a batch reactor to obtain methyl lactate (ester), (ii) separation of the ester in a batch distillation, (iii) hydrolysis of the ester with water in a batch reactor to produce lactic acid and (iv) separation of lactic acid (in high purity) in a batch distillation. Batch reactive distillation combines the benefit of both batch reactor and batch distillation and enhances conversion and productivity (Taylor and Krishna, 2000 ; Mujtaba and Macchietto, 1997 ). Therefore, the first and the last two steps of the lactic acid production process can be combined together in batch reactive distillation () processes. However, distillation (batch or continuous) is an energy intensive process and consumes large amount of thermal energy (via steam). This paper highlights how significant (over 50%) reduction in thermal energy consumption can be achieved for lactic acid production process by carefully controlling the reflux ratio but without compromising the product specification. In this paper, only the simultaneous hydrolysis of methyl lactate ester and the separation of lactic acid using batch reactive distillation is considered.

  8. Reduction of Tetravalent Plutonium in the Presence of Acetohydroxamic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Tkac, Peter [Radiation Center, Oregon State University, Corvallis, OR (United States); Precek, Martin [Department of Chemistry, Oregon State University, Corvallis, OR (United States); Paulenova, Alena [Department of Nuclear Engineering and Radiation Health Physics, Oregon State University, Corvallis, OR (United States)

    2009-06-15

    Acetohydroxamic acid (AHA) has been proposed as a salt-free stripping reagent in the modified PUREX process for the spent nuclear fuel re-processing. AHA is a capable reductant of Np(VI) and Pu(VI) and a strong complexant for tetravalent neptunium and plutonium; hence, its behavior must be studied in detail. For better characterization of the all relevant chemical processes and successful design of the future separation flowsheets it is important to predict the speciation and partitioning of Pu between the organic and aqueous phases in the proposed extraction systems containing acetohydroxamic acid. The hydrolytic instability of hydroxamic group under acidic conditions causes a slow degradation of AHA followed by formation of acetic acid and hydroxylamine which also acts as a reductant of Pu(IV). The complexes of Pu(IV) with AHA are very strong; however, under acidic conditions, the chelate ring prevents the acidic hydrolysis only temporarily. The decomposition of Pu-aceto-hydroxamate complex and reduction of Pu(IV) to Pu(III) observed for these systems was investigated in the present paper. Reduction of Pu(IV) in the presence of AHA was monitored by Vis-NIR spectroscopy in the range of 400-700 nm. All complexes between Pu(IV) and AHA have a very intense absorption in this region; therefore, for a better resolution of spectra, all experiments were performed under low AHA:Pu ratios, where only two species, non-complexed Pu(IV) and Pu(IV)-mono-aceto-hydroxamate complex, are initially present in relevant concentrations. To characterize the rate and the reaction mechanism, spectra were collected as a function of time for different initial concentrations of reactants and analyzed at several wavelengths using the data on extinction coefficients for all absorbing species. The extinction coefficient for Pu(IV)-AHA complex was resolved by fitting the absorption spectra with the chemical equilibrium modeling software FITEQL 4.0. The analysis of the experimental data obtained

  9. Reduction of nitrobenzene with alkaline ascorbic acid: Kinetics and pathways

    International Nuclear Information System (INIS)

    Liang, Chenju; Lin, Ya-Ting; Shiu, Jia-Wei

    2016-01-01

    Highlights: • Alkaline ascorbic acid (a.k.a. vitamin C) is capable of reductively degrading NB. • The pH above the pK_a_2 of ascorbic acid increases reductive electron transfer to NB. • The rate equation for the reactions between NB and AA is determined. • NSB, AZOXY, and AZO are identified as intermediates and aniline as a final product. • Alkaline pH is essential for AA remediation of NB contaminated soils. - Abstract: Alkaline ascorbic acid (AA) exhibits the potential to reductively degrade nitrobenzene (NB), which is the simplest of the nitroaromatic compounds. The nitro group (NO_2"−) of NB has a +III oxidation state of the N atom and tends to gain electrons. The effect of alkaline pH ranging from 9 to 13 was initially assessed and the results demonstrated that the solution pH, when approaching or above the pK_a_2 of AA (11.79), would increase reductive electron transfer to NB. The rate equation for the reactions between NB and AA at pH 12 can be described as r = ((0.89 ± 0.11) × 10"−"4 mM"1"−"("a "+ "b") h"−"1) × [NB]"a "= "1"."3"5 "± "0"."1"0[AA]"b "= "0"."8"9 "± "0"."0"1. The GC/MS analytical method identified nitrosobenzene, azoxybenzene, and azobenzene as NB reduction intermediates, and aniline (AN) as a final product. These experimental results indicate that the alkaline AA reduction of NB to AN mainly proceeds via the direct route, consisting of a series of two-electron or four-electron transfers, and the condensation reaction plays a minor route. Preliminary evaluation of the remediation of spiked NB contaminated soils revealed that maintenance of alkaline pH and a higher water to soil ratio are essential for a successful alkaline AA application.

  10. Sucrose tricarboxylate by sonocatalysed TEMPO-mediated oxidation.

    Science.gov (United States)

    Lemoine, S; Thomazeau, C; Joannard, D; Trombotto, S; Descotes, G; Bouchu, A; Queneau, Y

    2000-06-16

    Oxidation of sucrose by the NaOCl/TEMPO system provided sucrose tricarboxylate without the addition of sodium bromide as co-catalyst when high-frequency (500 kHz) ultrasound was applied, in contrast to very limited conversion without sonication. In the presence of sodium bromide, sonication also caused acceleration of the oxidation. The rate increase due to sonication of the oxidant system prior to sucrose addition suggests that ultrasound acts at the level of the formation of the nitrosonium ion, the active oxidising species in the catalytic cycle.

  11. Reduction of nitrobenzene with alkaline ascorbic acid: Kinetics and pathways

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chenju, E-mail: cliang@nchu.edu.tw [Department of Environmental Engineering, National Chung Hsing University 250, Kuo-kuang Road, Taichung 402, Taiwan (China); Lin, Ya-Ting [Department of Environmental Engineering, Chung Yuan Christian University, 200 Chung Pei Road, Chung Li District, Taoyuan City 320, Taiwan (China); Shiu, Jia-Wei [Department of Environmental Engineering, National Chung Hsing University 250, Kuo-kuang Road, Taichung 402, Taiwan (China)

    2016-01-25

    Highlights: • Alkaline ascorbic acid (a.k.a. vitamin C) is capable of reductively degrading NB. • The pH above the pK{sub a2} of ascorbic acid increases reductive electron transfer to NB. • The rate equation for the reactions between NB and AA is determined. • NSB, AZOXY, and AZO are identified as intermediates and aniline as a final product. • Alkaline pH is essential for AA remediation of NB contaminated soils. - Abstract: Alkaline ascorbic acid (AA) exhibits the potential to reductively degrade nitrobenzene (NB), which is the simplest of the nitroaromatic compounds. The nitro group (NO{sub 2}{sup −}) of NB has a +III oxidation state of the N atom and tends to gain electrons. The effect of alkaline pH ranging from 9 to 13 was initially assessed and the results demonstrated that the solution pH, when approaching or above the pK{sub a2} of AA (11.79), would increase reductive electron transfer to NB. The rate equation for the reactions between NB and AA at pH 12 can be described as r = ((0.89 ± 0.11) × 10{sup −4} mM{sup 1−(a} {sup +} {sup b)} h{sup −1}) × [NB]{sup a} {sup =} {sup 1.35} {sup ±} {sup 0.10}[AA]{sup b} {sup =} {sup 0.89} {sup ±} {sup 0.01}. The GC/MS analytical method identified nitrosobenzene, azoxybenzene, and azobenzene as NB reduction intermediates, and aniline (AN) as a final product. These experimental results indicate that the alkaline AA reduction of NB to AN mainly proceeds via the direct route, consisting of a series of two-electron or four-electron transfers, and the condensation reaction plays a minor route. Preliminary evaluation of the remediation of spiked NB contaminated soils revealed that maintenance of alkaline pH and a higher water to soil ratio are essential for a successful alkaline AA application.

  12. Lewis Acid Assisted Nitrate Reduction with Biomimetic Molybdenum Oxotransferase Complex.

    Science.gov (United States)

    Elrod, Lee Taylor; Kim, Eunsuk

    2018-03-05

    The reduction of nitrate (NO 3 - ) to nitrite (NO 2 - ) is of significant biological and environmental importance. While Mo IV (O) and Mo VI (O) 2 complexes that mimic the active site structure of nitrate reducing enzymes are prevalent, few of these model complexes can reduce nitrate to nitrite through oxygen atom transfer (OAT) chemistry. We present a novel strategy to induce nitrate reduction chemistry of a previously known catalyst Mo IV (O)(SN) 2 (2), where SN = bis(4- tert-butylphenyl)-2-pyridylmethanethiolate, that is otherwise incapable of achieving OAT with nitrate. Addition of nitrate with the Lewis acid Sc(OTf) 3 (OTf = trifluoromethanesulfonate) to 2 results in an immediate and clean conversion of 2 to Mo VI (O) 2 (SN) 2 (1). The Lewis acid additive further reacts with the OAT product, nitrite, to form N 2 O and O 2 . This work highlights the ability of Sc 3+ additives to expand the reactivity scope of an existing Mo IV (O) complex together with which Sc 3+ can convert nitrate to stable gaseous molecules.

  13. Sodium borohydride reduction of aromatic carboxylic acids via ...

    Indian Academy of Sciences (India)

    Unknown

    using a sodium borohydride–THF–methanol system. The alcohols ... rature using ethanol or methanol as solvent. Although, .... acids, phenylacetic acids, phenylpropanoic acid and cinnamic ... excess of reagent in water or alcohol, involved a.

  14. Optimization of conditions to produce nitrous gases by electrochemical reduction of nitric acid

    International Nuclear Information System (INIS)

    Lemaire, M.; CEA Centre d'Etudes de la Vallee du Rhone, 30 -Marcoule

    1996-01-01

    Gaseous nitrogen oxides (NO and NO 2 ) involved as oxidizing agents in nuclear fuel reprocessing can be an produced by electrochemical reduction of nitric acid. This could be an interesting alternative to the usual process because no wastes are generated. Voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0.05 V S HE and 0.3 V S HE and O.5 V S HE and 1 V S HE. The highest potential region reduction mechanism was studies by: classical micro-electrolysis methods; macro-electrolysis methods; infra-red spectroscopy couplet to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric acid reduction can also be explained by an other chemical reaction. In the potential value of platinum electrode is above 0.8 V S HE, products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author)

  15. Optimization of the nitrous vapors experimental conditions production by nitric acid electrochemical reduction

    International Nuclear Information System (INIS)

    Lemaire, M.

    1996-01-01

    Gaseous nitrogen oxides (NO and NO 2 ) involved as oxidizing agents in nuclear fuel reprocessing can be produced by electrochemical reduction of nitric acid. This is an interesting alternative to the existing process because no wastes are generated. voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0,05 V SHE and between 0,5 V SHE and 1 V SHE . The highest potential region reduction mechanism was studied by: classical micro-electrolysis methods, macro-electrolysis methods, infrared spectroscopy coupled to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric reduction can also explained by an other chemical reaction. If the potential value of platinum electrode is above 0,8 V SHE , products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author)

  16. Utilizing ultrasonic energy for reduction of free fatty acids in crude ...

    African Journals Online (AJOL)

    Ultrasonic energy was used for the reduction of FFA in CPO. FFA content was measured at different sonication intervals, and the optimum time was determined. Hydrochloric acid showed the highest catalytic activity in the reduction of FFA content in CPO, as well as in converting FFA to fatty acid methyl ester (FAME).

  17. [KDy(Hptc3(H3ptc]n·2n(Hbipy·5n(H2O, a Layered Coordination Polymer Containing DyO6N3 Tri-Capped Trigonal Prisms (H3ptc = Pyridine 2,4,6-Tricarboxylic Acid, C8H5NO6; Bipy = 2,2'-Bipyridine, C10H8N2

    Directory of Open Access Journals (Sweden)

    Shoaib Anwar

    2012-08-01

    Full Text Available The synthesis, structure and properties of the bimetallic layered coordination polymer, [KDy(C8H3NO63(C8H5NO6]n·2n(C10H9N2·5n(H2O = [KDy(Hptc3(H3ptc]n·2n(Hbipy·5n(H2O, are described. The Dy3+ ion is coordinated by three O,N,O-tridentate doubly-deprotonated pyridine tri-carboxylate (Hptc ligands to generate a fairly regular DyO6N3 tri-capped trigonal prism, with the N atoms acting as the caps. The potassium ion is coordinated by an O,N,O-tridentate H3ptc molecule as well as monodentate and bidentate Hptc ligands to result in an irregular KNO9 coordination geometry. The ligands bridge the metal-atom nodes into a bimetallic, layered, coordination polymer, which extends as corrugated layers in the (010 plane, with the mono-protonated bipyridine cations and water molecules occupying the inter-layer regions: Unlike related structures, there are no dysprosium–water bonds. Many O–HLO and N–HLO hydrogen bonds consolidate the structure. Characterization and bioactivity data are described. Crystal data: C52H42DyKN8O29, Mr = 1444.54, triclinic,  (No. 2, Z = 2, a = 9.188(2 Å, b = 15.7332(17 Å, c = 19.1664(19 Å, α = 92.797(6°, β = 92.319(7°, γ = 91.273(9°, V = 2764.3(7 Å3, R(F = 0.029, wR(F2 = 0.084.

  18. Reduction of NO adlayers on Pt(110) and Pt(111) in acidic media: evidence for adsorption site-specific reduction

    NARCIS (Netherlands)

    Rosca, V.; Beltramo, G.L.; Koper, M.T.M.

    2005-01-01

    We present a combined in situ Fourier transform infrared reflection-absorption spectroscopy and voltammetric study of the reduction of saturated and subsaturated NO adlayers on Pt(111) and Pt(110) single-crystal surfaces in acidic media. The stripping voltammetry experiments and the associated

  19. Exploring the reductive capacity of Pyrococcus furiosus : the reduction of carboxylic acids and pyridine nucleotides

    NARCIS (Netherlands)

    Ban, van den E.C.D.

    2001-01-01

    This Ph.D. project started in 1997 and its main goal was to obtain insight in the reductive capacity of the hyperthermophilic archaeon Pyrococcus furiosus . The research was focused on the biocatalytic reduction of carboxylic

  20. Microemulsion formulation of clonixic acid: solubility enhancement and pain reduction.

    Science.gov (United States)

    Lee, Jung-Mi; Park, Kyung-Mi; Lim, Soo-Jeong; Lee, Mi-Kyung; Kim, Chong-Kook

    2002-01-01

    Clonixic acid is currently marketed as a salt form because of its poor water-solubility. However, the commercial dosage form causes severe pain after intramuscular or intravenous injection. To improve the solubility of clonixic acid and to reduce pain on injection, clonixic acid was incorporated into oil-in-water microemulsions prepared from pre-microemulsion concentrate composed of varying ratios of oil and surfactant mixture. As an oil phase for drug incorporation, up to 14% castor oil could be included in the pre-microemulsion concentrate without a significant increase in droplet size. Both drug contents and droplet size increased as the weight ratio of Tween 20 to Tween 85 decreased. Taken together, when microemulsions were prepared from pre-microemulsion concentrate composed of 5:12:18 weight ratio of castor oil:Tween 20:Tween 85, clonixic acid could be incorporated at 3.2 mg mL(-1) in the microemulsion with a droplet size of less than 120 nm. The osmotic pressure of this microemulsion was remarkably lower than the commercial formulation, irrespective of the dilution ratios. The rat paw-lick test was used to compare pain responses among formulations. The microemulsion formulation significantly reduced the number of rats licking their paws as well as the total licking time, suggesting less pain induction by the microemulsion formulation. The pharmacokinetic parameters of clonixic acid after intravenous administration of the clonixic acid microemulsion to rats were not significantly different from those of the commercial formulation, lysine clonixinate. The present study suggests that microemulsion is an alternative formulation for clonixic acid with improved characteristics.

  1. Kinetics and mechanism of reduction of cerium(IV) by ascorbic acid

    International Nuclear Information System (INIS)

    Bhatt, K.; Nand, K.C.

    1979-01-01

    The reduction of cerium(IV) has been studied in sulfuric acid medium using ascorbic acid as the reductant. The rate is found to be function of both Ce(IV) and AH 2 concentrations. Sulfuric acid retards the rate and the inverse order with respect to sulfuric acid is unity. The addition of chloride, bisulfate and sulfate of sodium show negative salt effect and an increase in the dielectric constant of the medium shows an accelerating effect on the reaction rate. Arrhenius parameters have been evaluated. A mechanism involving intermediate formation of ascorbate radical (AH) is proposed and the derived rate law agrees well with the experimental observations. (author)

  2. Sulfate Reduction at Low Ph To Remediate Acid Mine Drainage

    NARCIS (Netherlands)

    Sánchez-Andrea, I.; Sanz, J.L.; Bijmans, M.F.M.; Stams, A.J.M.

    2014-01-01

    Industrial activities and the natural oxidation of metallic sulfide-ores produce sulfate-rich waters with low pH and high heavy metals content, generally termed acid mine drainage (AMD). This is of great environmental concern as some heavy metals are highly toxic. Within a number of possibilities,

  3. System for NO reduction using sublimation of cyanuric acid

    Science.gov (United States)

    Perry, R.A.

    1989-01-24

    An arrangement for reducing the NO content of a gas stream comprises contacting the gas stream with HNCO at a temperature effective for heat induced decomposition of HNCO and for resultant lowering of the NO content of the gas stream. Preferably, the HNCO is generated by sublimation of cyanuric acid. 1 fig.

  4. Acid-catalyzed reductive amination of aldoses with 8-aminopyrene-1,3,6-trisulfonate.

    Science.gov (United States)

    Evangelista, R A; Guttman, A; Chen, F T

    1996-02-01

    The reductive amination of monosaccharides with 8-aminopyrene-1,3,6-trisulfonate (APTS) in seven different organic acids including the commonly used acetic acid was investigated by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. The correlation between the yields of the saccharide-APTS adducts and pKa of the organic acid catalyst is consistent with general acid catalysis of the rate-determining step of the reductive amination reaction. Derivatization in the presence of organic acids of higher strength than acetic acid produced substantially higher yields of APTS-sugar adducts, an effect which is more pronounced for N-acetylamino sugars. Optimum yields were obtained using citric acid as a catalyst. Conversion of a few nanomoles of neutral saccharides to the APTS derivatives is achieved at 75 degrees C in less than 60 min.

  5. Efficacy of lactic acid bacteria in the reduction of trimethylamine ...

    African Journals Online (AJOL)

    P. acidilactici cell coat reduced 40 mg% of TMA-N, 47.66 mg% of FFA, 97 mg% of PV and 97 mg% of PV when compared with control. The TMA-N content was reduced to 20 mg% by S. thermophilus cell coat on the treated fish when compared with control, while no reduction was observed on TVB-N. Out of the seven LAB ...

  6. Noise reduction methods for nucleic acid and macromolecule sequencing

    Science.gov (United States)

    Schuller, Ivan K.; Di Ventra, Massimiliano; Balatsky, Alexander

    2018-05-08

    Methods, systems, and devices are disclosed for processing macromolecule sequencing data with substantial noise reduction. In one aspect, a method for reducing noise in a sequential measurement of a macromolecule comprising serial subunits includes cross-correlating multiple measured signals of a physical property of subunits of interest of the macromolecule, the multiple measured signals including the time data associated with the measurement of the signal, to remove or at least reduce signal noise that is not in the same frequency and in phase with the systematic signal contribution of the measured signals.

  7. The influence of nitrate concentrations and acidity on the electrocatalytic reduction of nitrate on platinum

    NARCIS (Netherlands)

    Groot, de M.T.; Koper, M.T.M.

    2004-01-01

    A study was performed to determine the influence of nitrate concentration and acidity on the reaction rate and selectivity of the electrocatalytic nitrate reduction on platinum. There are two different nitrate reduction mechanisms on platinum: a direct mechanism (0.4–0.1 V vs. SHE) and an indirect

  8. Study of the mechanism and kinetics of the reduction of uranyl ions in phosphoric acid solutions

    International Nuclear Information System (INIS)

    El Kacemi, K.; Tyburce, B.; Belcadi, S.

    1982-01-01

    The electrochemical reduction of uranyl ions in 0.1 to 9 M phosphoric acid has been investigated by polarography, cyclic voltammetry, chronopotentiometry and potentiostatic coulometry. In concentrated phosphoric acid solutions (H 3 PO 4 3 PO 4 concentrations. So, when the concentration of U(VI) increases and/or that of H 3 PO 4 reduces, the system becomes reversible. (author)

  9. Asymmetric synthesis of α-amino acids by reduction of N-tert-butanesulfinyl ketimine esters.

    Science.gov (United States)

    Reddy, Leleti Rajender; Gupta, Aditya P; Liu, Yugang

    2011-05-06

    A highly regio- and diastereoselective reduction of various N-tert-butanesulfinyl ketimine esters with L-Selectride resulting in the formation of α-amino acids is reported. This method is quite general and also practical for the preparation of both enantiomers of aryl or aliphatic α-amino acids in high yields. © 2011 American Chemical Society

  10. Primary oxidation and reduction products in x-irradiated aspartic acid

    International Nuclear Information System (INIS)

    Adams, S.M.; Budzinski, E.E.; Box, H.C.

    1976-01-01

    The primary reduction products identified by ESR--ENDOR spectroscopy in single crystals of DL-aspartic acid hydrochloride irradiated at 4.2degreeK are anions formed by addition of an electron to the carbonyl oxygen atoms of the carboxylic acid groups. The main consequence of the oxidation process is to produce a hole centered mainly on atomic chlorine

  11. Reduction of trace quantities of chromium(VI by strong acids

    Directory of Open Access Journals (Sweden)

    Pezzin Sérgio H

    2004-01-01

    Full Text Available The chemical behavior of Cr(VI at low concentrations (10-4 to 10-7 mol L-1 in several strong acids was studied using high specific activity 51Cr(VI as a tracer. The speciation of the products from these systems was carried out by ion exchange chromatography with stepwise elution. The results show that trace quantities of Cr(VI, monitored by means of radiochromium (51Cr, are reduced in the presence of mineral acids such as perchloric, hydrochloric, hydrofluoric, sulfuric, nitric and trifluoromethanesulfonic acids, even in the absence of conventional reducing agents, producing different measureable Cr(III species, depending on the acid anion. Detailed studies of the reduction of low concentrations of Cr(VI with nitric acid have shown that the relative rate of reduction increases as the concentration of the acid increases or as the concentration of the Cr(VI decreases.

  12. WASTE REDUCTION IN CARMINIC ACID PRODUCTION BY APPLYING PINCH TECHNOLOGY

    OpenAIRE

    Erazo E., Raymundo; Cárdenas R., Jorge L.; Woolcott H., Juan C.

    2014-01-01

    An integrated approach to the design and analisis of heat exchanger networrks (HEN) Is outlined. A case study is used, carminic acid,, to illustrate this integrated approach, to emphasize the economy of 60% energy with respect to convectional process. Se esbozó un análisis de integración de energía por aproximación para el diseño y análisis de una red de transferencia de calor (HEN). Se utilizó un caso estudio, ácido carmínico, para ilustrar esta vía de integración por aproximación y resal...

  13. Fumaric acid production in Saccharomyces cerevisiae by simultaneous use of oxidative and reductive routes.

    Science.gov (United States)

    Xu, Guoqiang; Chen, Xiulai; Liu, Liming; Jiang, Linghuo

    2013-11-01

    In this study, the simultaneous use of reductive and oxidative routes to produce fumaric acid was explored. The strain FMME003 (Saccharomyces cerevisiae CEN.PK2-1CΔTHI2) exhibited capability to accumulate pyruvate and was used for fumaric acid production. The fum1 mutant FMME004 could produce fumaric acid via oxidative route, but the introduction of reductive route derived from Rhizopus oryzae NRRL 1526 led to lower fumaric acid production. Analysis of the key factors associated with fumaric acid production revealed that pyruvate carboxylase had a low degree of control over the carbon flow to malic acid. The fumaric acid titer was improved dramatically when the heterologous gene RoPYC was overexpressed and 32 μg/L of biotin was added. Furthermore, under the optimal carbon/nitrogen ratio, the engineered strain FMME004-6 could produce up to 5.64 ± 0.16 g/L of fumaric acid. These results demonstrated that the proposed fermentative method is efficient for fumaric acid production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Dissolution of magnetite in a dilute chemical decontaminant formulation containing gallic acid as a reductant

    International Nuclear Information System (INIS)

    Kishore, Kamal; Rajesh, Puspalata; Dey, G.R.

    2000-01-01

    Gallic acid (GA) was tried as a reductant in place of ascorbic acid in dilute chemical decontaminant (DCD) formulations. Dissolution of magnetite in GA based DCD formulations was studied at 50 deg as well as 80 degC. It was found to be a good substitute for ascorbic acid in EDTA/ascorbic acid/citric acid i.e. EAC formulation. The efficiency of EDTA/GA/CA formulation was as good as that of EAC formulation. 2.8 was found to be the optimum pH for this formulation and dissolution decreased at lower as well as higher pHs. The ion-exchange behaviour of GA is also appropriate for using it in a regenerating type of formulation. Being an aromatic compound, gallic acid has inherent stability against radiation degradation. (author)

  15. A dilute chemical decontaminant formulation containing gallic acid as a reductant

    International Nuclear Information System (INIS)

    Kishore, K.; Rajesh, P.; Kumbhar, A.G.

    2001-01-01

    Gallic acid (GA) was tried as a reductant in place of ascorbic acid in dilute chemical decontaminant (DCD) formulations. Dissolution of magnetite in GA based DCD formulations was studied at 50 C as well as 80 C. It was found to be a good substitute for ascorbic acid in EDTA/ascorbic acid/citric acid, i.e., EAC formulation. The efficiency of EDTA/GA/CA formulation was as good as that of EAC formulation. 2.8 was found to be the optimum pH for this formulation and dissolution decreased at lower as well as higher pHs. The ion exchange behaviour of GA is also appropriate for using it in a regenerating type of formulation. Being an aromatic compound, Gallic acid has inherent stability against radiation degradation. (orig.)

  16. Gastric acid reduction leads to an alteration in lower intestinal microflora

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, Takayuki [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Matsuki, Takahiro [Yakult Central Institute for Microbiological Research, Tokyo (Japan); Oka, Masashi; Utsunomiya, Hirotoshi [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Inada, Kenichi [First Department of Pathology, Fujita Health University School of Medicine, Aichi (Japan); Magari, Hirohito; Inoue, Izumi; Maekita, Takao; Ueda, Kazuki; Enomoto, Shotaro; Iguchi, Mikitaka; Yanaoka, Kimihiko; Tamai, Hideyuki [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Akimoto, Shigeru [Department of Microbiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan); Nomoto, Koji; Tanaka, Ryuichiro [Yakult Central Institute for Microbiological Research, Tokyo (Japan); Ichinose, Masao, E-mail: ichinose@wakayama-med.ac.jp [Department of Gastroenterology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-city, Wakayama 641-0012 (Japan)

    2009-04-17

    To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.

  17. Gastric acid reduction leads to an alteration in lower intestinal microflora

    International Nuclear Information System (INIS)

    Kanno, Takayuki; Matsuki, Takahiro; Oka, Masashi; Utsunomiya, Hirotoshi; Inada, Kenichi; Magari, Hirohito; Inoue, Izumi; Maekita, Takao; Ueda, Kazuki; Enomoto, Shotaro; Iguchi, Mikitaka; Yanaoka, Kimihiko; Tamai, Hideyuki; Akimoto, Shigeru; Nomoto, Koji; Tanaka, Ryuichiro; Ichinose, Masao

    2009-01-01

    To clarify the alterations in lower intestinal microflora induced by gastric acid reduction, the dynamics of 12 major genera or groups of bacteria comprising the microflora in feces and colonic contents were examined by quantitative real-time PCR in proton pump inhibitor-treated rats and in asymptomatic human subjects with hypochlorhydria. In both rat and human experiments, most genera or groups of intestinal microflora (facultative and obligate anaerobes) proliferated by gastric acid reduction, and marked and significant increases in the Lactobacilli group and Veillonella, oropharyngeal bacteria, were observed. In rats, potent gastric acid inhibition led to a marked and significant increase of intestinal bacteria, including the Bacteroidesfragilis group, while Bifidobacterium, a beneficial bacterial species, remained at a constant level. These results strongly indicate that the gastric acid barrier not only controls the colonization and growth of oropharyngeal bacteria, but also regulates the population and composition of lower intestinal microflora.

  18. Determination of Decimal Reduction Time of Peracetic Acid Used in Brewery Industry for Disinfection Purposes

    OpenAIRE

    , N. Lajçi; , X. Lajçi; , B. Baruti

    2016-01-01

    Disinfection operation is of great importance within the beer processing industry for beer safety reasons. Microbiological risk management is essential in the production of high-quality beer since quality defects may lead to substantial economic losses. The objective of this research was to investigate the effect of commercial peracetic acid (PAA) concentration for disinfection and the resistance of microorganisms in beer based on the decimal reduction time (D-value), and reduction 6-log10 of...

  19. Acidogenesis driven by hydrogen partial pressure towards bioethanol production through fatty acids reduction

    International Nuclear Information System (INIS)

    Sarkar, Omprakash; Butti, Sai Kishore; Venkata Mohan, S.

    2017-01-01

    H 2 partial pressure drives the reduction of carboxylic acid (short chain fatty acids) formed as primary metabolites in acidogenic fermentation to form bioalcohols. Microbial catalysis under the influence of H 2 partial pressure was evaluated in comparison with a reactor operated at atmospheric pressure under identical conditions. Carboxylic acid reduction gets regulated selectively by the influence of elevated pressures and redox conditions, resulting in the formation of alcohols. The non-equilibrium of the intra and extracellular H 2 ions causes the anaerobic bacteria to alter their pathways as a function of interspecies H 2 transfer. Ethanol production was quantified, as acetic acid was the major carboxylic acid synthesised during acidogenesis. H 2 pressure influenced the electrochemical activity which was reflected in the distinct variation of the electron transfer rates and the catalytic activity of redox mediators (NAD + /NADH, flavoproteins and iron-sulphur clusters). The bioprocess depicted in this communication depicted a non-genetic regulation of product formation, understanding the acidogenic metabolism and alternate route for alcohol production. - Highlights: • H 2 partial pressure in HPR aided in the reduction of carboxylic acids to alcohols. • Production and consumption rate of VFAs were correlating with alcohol formation. • Metabolic shift was evident with bioelectrochical analysis. • NADH/NAD + ratio and H 2 partial pressure coupled in enhanced solventogenesis.

  20. Optimization of the nitrous vapors experimental conditions production by nitric acid electrochemical reduction; Optimisation des conditions operatoires de production de vapeurs nitreuses par reduction electrochimique d`acide nitrique

    Energy Technology Data Exchange (ETDEWEB)

    Lemaire, M.

    1996-11-22

    Gaseous nitrogen oxides (NO and NO{sub 2}) involved as oxidizing agents in nuclear fuel reprocessing can be produced by electrochemical reduction of nitric acid. This is an interesting alternative to the existing process because no wastes are generated. voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0,05 V{sub SHE} and between 0,5 V{sub SHE} and 1 V{sub SHE}. The highest potential region reduction mechanism was studied by: classical micro-electrolysis methods, macro-electrolysis methods, infrared spectroscopy coupled to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric reduction can also explained by an other chemical reaction. If the potential value of platinum electrode is above 0,8 V{sub SHE}, products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author). 91 refs.

  1. Novel metal-organic and supramolecular 3D frameworks constructed from flexible biphenyl-2,5,3‧-tricarboxylate blocks: Synthesis, structural features and properties

    Science.gov (United States)

    You, Ao; Li, Yu; Zhang, Ze-Min; Zou, Xun-Zhong; Gu, Jin-Zhong; Kirillov, Alexander M.; Chen, Jin-Wei; Chen, Yun-Bo

    2017-10-01

    Biphenyl-2,5,3‧-tricarboxylic acid (H3L) was selected as an unexplored tricarboxylate building block and applied for the hydrothermal synthesis of three novel coordination compounds, namely a 0D tetramer [Co4(HL)2(μ3-HL)2(phen)6(H2O)2]·3H2O (1) and two 3D metal-organic frameworks (MOFs) [Cd3(μ5-L)(μ6-L)(py)(μ-H2O)2(H2O)]n·H2O (2) and [Zn3(μ4-L)2(2,2‧-bpy)(μ-4,4‧-bpy)]n·2H2O (3). These products were easily generated in aqueous medium from the corresponding metal(II) chlorides, H3L, and various N-donor ancillary ligands, selected from 1,10-phenanthroline (phen), pyridine (py), 2,2‧-bipyridine (2,2‧-bpy), and 4,4‧-bipyridine (4,4‧-bpy). Compounds 1-3 were isolated as stable crystalline solids and were fully characterized by IR and UV-vis spectroscopy, elemental, thermogravimetric (TGA), powder (PXRD) and single-crystal X-ray diffraction analyses. Compound 1 possesses a discrete tetracobalt(II) structure, which is extended into a 3D H-bonded network with the pcu topology. In contrast, MOF 2 discloses a very complex trinodal 4,5,12-connected net with an undocumented topology, while MOF 3 features the nce/I topological framework. The magnetic (for 1) and luminescence (for 2 and 3) properties were also studied and discussed. The present study thus widens a still very limited family of metal-organic and supramolecular frameworks driven by flexible biphenyl-2,5,3‧-tricarboxylate building blocks.

  2. Effect of a reduction in uric acid on renal outcomes during losartan treatment

    DEFF Research Database (Denmark)

    Miao, Yan; Ottenbros, Stefan A; Laverman, Goos D

    2011-01-01

    Emerging data show that increased serum uric acid (SUA) concentration is an independent risk factor for end-stage renal disease. Treatment with the antihypertensive drug losartan lowers SUA. Whether reductions in SUA during losartan therapy are associated with renoprotection is unclear. We...

  3. Theoretical Insight into the Trends that Guide the Electrochemical Reduction of Carbon Dioxide to Formic Acid

    DEFF Research Database (Denmark)

    Yoo, J.S.; Christensen, Rune; Vegge, Tejs

    2016-01-01

    The electrochemical reduction (electroreduction) of CO2 to formic acid (HCOOH) and its competing reactions, that is, the electroreduction of CO2 to CO and the hydrogen evolution reaction (HER), on twenty-seven different metal surfaces have been investigated using density functional theory (DFT) c...

  4. Regulation of acidity and reduction of turbidity in the clarified pomegranate juice production

    OpenAIRE

    ESHMATOV FOZIL KHIDIROVICH; MAKSUMOVA DILRABO KUCHKAROVNA; DODAEVA LAYLO KUCHKAROVNA

    2016-01-01

    Regulation of acidity and reduction of turbidity in the clarified pomegranate juice production. From sour varieties of pomegranates may obtain normal natural pomegranate juice by anion-exchange resin. There are determined problems quantity of precipitate and unstable color in the pomegranate juice and concentrate by experimentally.

  5. Reduction of Acid-Fast and Non-Acid-Fast Bacteria by Point of Use Coagulation-Flocculation-Disinfection

    Directory of Open Access Journals (Sweden)

    Lisa M. Casanova

    2015-11-01

    Full Text Available Point of use (POU household water treatment is increasingly being adopted as a solution for access to safe water. Non-tuberculous Mycobacteria (NTM are found in water, but there is little research on whether NTM survive POU treatment. Mycobacteria may be removed by multi-barrier treatment systems that combine processes such as coagulation, settling and disinfection. This work evaluated removal of a non-tuberculous Mycobacterium (Mycobaterium terrae and a Gram-negative non-acid-fast environmental bacterium (Aeromonas hydrophila by combined coagulation-flocculation disinfection POU treatment. Aeromonas hydrophila showed 7.7 log10 reduction in demand free buffer, 6.8 log10 in natural surface water, and 4 log10 reduction in fecally contaminated surface water. Turbidity after treatment was <1 NTU. There was almost no reduction in levels of viable M. terrae by coagulant-flocculant-disinfectant in natural water after 30 minutes. The lack of Mycobacteria reduction was similar for both combined coagulant-flocculant-disinfectant and hypochlorite alone. A POU coagulant-flocculant-disinfectant treatment effectively reduced A. hydrophila from natural surface waters but not Mycobacteria. These results reinforce previous findings that POU coagulation-flocculation-disinfection is effective against gram-negative enteric bacteria. POU treatment and safe storage interventions may need to take into account risks from viable NTM in treated stored water and consider alternative treatment processes to achieve NTM reductions.

  6. Radiation-induced reductive modifications of sulfur-containing amino acids within peptides and proteins.

    Science.gov (United States)

    Chatgilialoglu, Chryssostomos; Ferreri, Carla; Torreggiani, Armida; Salzano, Anna Maria; Renzone, Giovanni; Scaloni, Andrea

    2011-10-19

    The complex scenario of radical stress reactions affecting peptides/proteins can be better elucidated through the design of biomimetic studies simulating the consequences of the different free radicals attacking amino acids. In this context, ionizing radiations allowed to examine the specific damages caused by H-atoms and electrons coupled with protons, thus establishing the molecular basis of reductive radical stress. This is an innovative concept that complements the well-known oxidative stress also in view of a complete understanding of the global consequences of radical species reactivities on living systems. This review summarizes the knowledge of the chemical changes present in sulfur-containing amino acids occurring in polypeptides under reductive radical conditions, in particular the transformation of Met and Cys residues into α-amino butyric acid and alanine, respectively. Reductive radical stress causing a desulfurization process, is therefore coupled with the formation of S-centered radicals, which in turn can diffuse apart and become responsible of the damage transfer from proteins to lipids. These reductive modifications assayed in different peptide/protein sequences constitute an integration of the molecular inventories that up to now take into account only oxidative transformations. They can be useful to achieve an integrated vision of the free radical reactivities in a multifunctional system and, overall, for wider applications in the redox proteomics field. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Thermodynamic and kinetic modelling of the reduction of concentrated nitric acid

    International Nuclear Information System (INIS)

    Sicsic, David

    2011-01-01

    This research thesis aimed at determining and quantifying the different stages of the reduction mechanism in the case of concentrated nitric acid. After having reported the results of a bibliographical study on the chemical and electrochemical behaviour of concentrated nitric media (generalities, chemical equilibriums, NOx reactivity, electrochemical reduction of nitric acid), the author reports the development and discusses the results of a thermodynamic simulation of a nitric environment at 25 C. This allowed the main species to be identified in the liquid and gaseous phases of nitric acid solutions. The author reports an experimental electrochemical investigation coupled with analytic techniques (infrared and UV-visible spectroscopy) and shows that the reduction process depends on the cathodic overvoltage, and identifies three potential areas. A kinetic modelling of the stationary state and of the impedance is then developed in order to better determine, discuss and quantify the reduction process. The application of this kinetic model to the preliminary results of an electrochemical study performed on 304 L steel is then discussed [fr

  8. Kinetics study on the reduction of trace plutonium (IV) by hydroxylamine in nitric acid media

    International Nuclear Information System (INIS)

    Fei Hongcheng; Luo Longjun

    1998-01-01

    Reaction kinetics of trace Pu(IV) (c(Pu(IV)≤10 -5 mol/L) with hydroxylamine in nitric acid solution is investigated. The effects of concentrations of Pu(IV), Pu(III), NO 3 - , H + and hydroxylamine on the reduction rate of trace Pu(IV) are examined. The rate law of reaction of trace Pu(IV) with hydroxylamine is obtained. The reduction rate of Pu(IV) increases obviously with increasing temperature and the apparent activation energy with k' 0 is equal to 147 kJ/mol. The reaction mechanism of trace Pu(IV) with hydroxylamine is discussed

  9. Optimization of conditions to produce nitrous gases by electrochemical reduction of nitric acid; Optimisation des conditions operatoires de production de vapeurs nitreuses par reduction electrochimique d`acide nitrique

    Energy Technology Data Exchange (ETDEWEB)

    Lemaire, M. [CEA Centre d`Etudes Nucleaires de Saclay, 91 -Gif-sur-Yvette (France)]|[CEA Centre d`Etudes de la Vallee du Rhone, 30 -Marcoule (France). Direction du Cycle du Combustible

    1996-11-22

    Gaseous nitrogen oxides (NO and NO{sub 2}) involved as oxidizing agents in nuclear fuel reprocessing can be an produced by electrochemical reduction of nitric acid. This could be an interesting alternative to the usual process because no wastes are generated. Voltammetric studies on a platinum electrode show that two reduction potential regions are observed in concentrated nitric acid solutions, between 0.05 V{sub S}HE and 0.3 V{sub S}HE and O.5 V{sub S}HE and 1 V{sub S}HE. The highest potential region reduction mechanism was studies by: classical micro-electrolysis methods; macro-electrolysis methods; infra-red spectroscopy couplet to electrochemistry. It was determined that the origin of nitric acid reduction is the electrochemical reduction of nitrous acid in nitric oxide which chemically reduces nitric acid. This reaction produces nitrous acid back which indicate an auto-catalytic behaviour of nitric acid reduction mechanism. Nitrogen dioxide evolution during nitric acid reduction can also be explained by an other chemical reaction. In the potential value of platinum electrode is above 0.8 V{sub S}HE, products of the indirect nitric acid reduction are nitrous acid, nitrogen oxide and nitrogen dioxide. Below this value nitric oxide can be reduced in nitrous oxide. Thus the potential value is the most important parameter for the nitrogen oxides production selectivity. However, owing to the auto-catalytic character of the reduction mechanism, potential value can be controlled during intentiostatic industrial electrolysis. (author). 91 refs.

  10. Voluntary reduction of trans-fatty acids in Latin America and the Caribbean: current situation.

    Science.gov (United States)

    Monge-Rojas, Rafael; Colón-Ramos, Uriyoán; Jacoby, Enrique; Mozaffarian, Dariush

    2011-02-01

    As part of the Pan American Health Organization/World Health Organization Trans-Fat-Free Americas initiative, 12 representatives from food industries in Latin America and the Caribbean signed a declaration stating their intention to voluntarily eliminate industrially produced trans-fatty acids (TFA) from the Americas. A year later, in order to document the extent of the voluntary reduction, each declarant was asked to describe all reformulations and reductions in the TFA content of their products. After up to six requests for data, only three declarants provided such information in detail, and three others offered an overall summary of their reformulations. Additionally, three declarants reported the barriers that limit this process: availability of oil substitutes, cost, and consumers' sensory acceptance. The content of TFA and saturated fat in the food supply in the Americas should be regulated and strictly monitored in order to adequately evaluate a reduction of TFA in the region.

  11. Selective rhodium-catalyzed reduction of tertiary amides in amino acid esters and peptides.

    Science.gov (United States)

    Das, Shoubhik; Li, Yuehui; Bornschein, Christoph; Pisiewicz, Sabine; Kiersch, Konstanze; Michalik, Dirk; Gallou, Fabrice; Junge, Kathrin; Beller, Matthias

    2015-10-12

    Efficient reduction of the tertiary amide bond in amino acid derivatives and peptides is described. Functional group selectivity has been achieved by applying a commercially available rhodium precursor and bis(diphenylphosphino)propane (dppp) ligand together with phenyl silane as a reductant. This methodology allows for specific reductive derivatization of biologically interesting peptides and offers straightforward access to a variety of novel peptide derivatives for chemical biology studies and potential pharmaceutical applications. The catalytic system tolerates a variety of functional groups including secondary amides, ester, nitrile, thiomethyl, and hydroxy groups. This convenient hydrosilylation reaction proceeds at ambient conditions and is operationally safe because no air-sensitive reagents or highly reactive metal hydrides are needed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Limiting Current of Oxygen Reduction on Gas-Diffusion Electrodes for Phosphoric Acid Fuel Cells

    DEFF Research Database (Denmark)

    Li, Qingfeng; Gang, Xiao; Hjuler, Hans Aage

    1994-01-01

    on polytetrafluorine-ethyl bonded gas-diffusion electordes in phosphoric acid with and without fluorinated additives. This provides an alternative to estimate the film thickness by combining it with the acid-adsorption measurements and the porosity analysis of the catalyst layer. It was noticed that the limiting......Various models have been devoted to the operation mechanism of porous diffusion electrodes. They are, however, suffering from the lack of accuracy concerning the acid-film thickness on which they are based. In the present paper the limiting current density has been measured for oxygen reduction...... current density can be accomplished either by gas-phase diffusion or liquid-phase diffusion, and it is the latter that can be used in the film-thickness estimation. It is also important to mention that at such a limiting condition, both the thin-film model and the filmed agglomerate model reach the same...

  13. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A., E-mail: jimfield@email.arizona.edu

    2016-11-05

    Highlights: • Algal biomass can serve as an electron donor to drive reduction of sulfate to sulfide. • Biogenic sulfide precipitates Cu{sup 2+} as stable sulfide mineral. • Cu{sup +2} removal in sulfidogenic bioreactors amended with algal biomass exceeded 99.5%. • Acidity in synthetic acid rock drainage was consumed by sulfate reduction. - Abstract: This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H{sub 2}SO{sub 4} and Cu{sup 2+}. Sulfate, sulfide, Cu{sup 2+} and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO{sub 4}{sup 2−} d{sup −1}) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu{sup 2+} removal were observed in the endogenous control. In algae amended-columns, Cu{sup 2+} was precipitated with biogenic H{sub 2}S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.

  14. Electrochemical studies on the reduction of uranyl ions in nitric acid-hydrazine media at platinum electrode

    International Nuclear Information System (INIS)

    Mishra, Satyabrata; Sini, K.; Mallika, C.; Kamachi Mudali, U.; Jagadeeswara Rao, Ch.

    2015-01-01

    Production of uranous nitrate with good conversion efficiency is one of the major steps in the aqueous reprocessing of spent fuels of nuclear reactors, as U(IV) is used for the separation of Pu from U by the selective reduction of Pu(IV) into practically non-extractable Pu(III) in aqueous streams. Electro-reduction of uranyl ions has the advantage of not introducing corrosive chemicals into the process stream. High current efficiency with maximum conversion of U(VI) to U(IV) can be achieved in continuous as well as batch mode electro-reduction, if the process is voltage-controlled rather than current controlled. As potentiostatic studies reveal the mechanism of reduction of uranyl ions in potential controlled electrolysis, the reduction behavior of uranyl ions (UO 2 2+ ) in nitric acid and nitric acid-hydrazine media were investigated by Cyclic Voltammetric (CV) and Chronopotentiometric (CP) techniques using platinum working electrode at 298 K. Heterogeneous electron transfer rate constant (ks) for uranyl reduction was estimated at a very low concentration of nitric acid (0.05 M) using Klinger and Kochi equation. Values of the diffusion coefficients were determined as a function of acidity with and without hydrazine. Reduction of uranyl ions was found to be under kinetic as well as diffusion control when the concentration of nitric acid was 0.05 M and in the absence of hydrazine. However, as the acidity of the supporting electrolyte increased, the reduction was purely under kinetic control. (author)

  15. 1,4-Dihydroxy fatty acids: Artifacts by reduction of di- and polyunsaturated fatty acids with sodium borohydride

    Science.gov (United States)

    Thiemt, Simone; Spiteller, Gerhard

    1997-01-01

    In an effort to detect lipid peroxidation products in human blood plasma, samples were treated with NaBH4 to reduce the reactive hydroperoxides to hydroxy compounds. After saponification of the lipids, the free fatty acid fraction obtained by extraction was methylated and separated by TLC. The fractions containing polar compounds were trimethylsilylated and subjected to gas chromatography-mass spectrometry (GC/MS). Mass spectra allowed us to detect previously unknown 1,4-dihydroxy fatty acids due to their typical fragmentation pattern. If the reduction was carried out with NaBD4 instead of NaBH4, incorporation of two deuterium atoms was observed (appropriate mass shift). The two oxygen atoms of the hydroxyl groups were incorporated from air as shown by an experiment in 18O2 atmosphere. The reaction required the presence of free acids, indicating that BH3 was liberated, added to a 1,4-pentadiene system, and finally produced 1,4-diols by air oxidation.

  16. Threshold changes in rat brain docosahexaenoic acid incorporation and concentration following graded reductions in dietary alpha-linolenic acid

    Science.gov (United States)

    Taha, Ameer Y.; Chang, Lisa; Chen, Mei

    2016-01-01

    Background This study tested the dietary level of alpha-linolenic acid (α-LNA, 18:3n-3) sufficient to maintain brain 14C-Docosahexaenoic acid (DHA, 22:6n-3) metabolism and concentration following graded α-LNA reduction. Methods 18–21 day male Fischer-344 (CDF) rats were randomized to the AIN-93G diet containing as a % of total fatty acids, 4.6% (“n-3 adequate”), 3.6%, 2.7%, 0.9% or 0.2% (“n-3 deficient”) α-LNA for 15 weeks. Rats were intravenously infused with 14C-DHA to steady state for 5 minutes, serial blood samples collected to obtain plasma and brains excised following microwave fixation. Labeled and unlabeled DHA concentrations were measured in plasma and brain to calculate the incorporation coefficient, k*, and incorporation rate, Jin. Results Compared to 4.6% α-LNA controls, k* was significantly increased in ethanolamine glycerophospholipids in the 0.2% α-LNA group. Circulating unesterified DHA and brain incorporation rates (Jin) were significantly reduced at 0.2% α-LNA. Brain total lipid and phospholipid DHA concentrations were reduced at or below 0.9% α-LNA. Conclusion Threshold changes for brain DHA metabolism and concentration were maintained at or below 0.9% dietary α-LNA, suggesting the presence of homeostatic mechanisms to maintain brain DHA metabolism when dietary α-LNA intake is low. PMID:26869088

  17. Volatile fatty acids as substrates for iron and sulfate reduction in Arctic marine sediments, Svalbard

    Science.gov (United States)

    Finke, N.; Vandieken, V.; Jorgensen, B. B.

    2006-12-01

    Anaerobic degradation of complex organic material in aquatic systems is a multi-step process. The metabolic products of fermentative bacteria serve as electron donors for the terminal oxidizing bacteria. In marine sediments, iron reduction and sulfate reduction are generally the most important terminal oxidation processes in the upper anoxic zone [1]. Microorganisms that reduce iron and sulfate may use a broad range of electron donors, yet the list of potential substrates provides little information about the substrates used in situ by these organisms. Investigations on the electron donors for sulfate reducers in marine sediments have shown that volatile fatty acids (VFA), and in particular acetate, together with hydrogen are the major substrates (e.g. [2-4]). Similar investigations for iron reduction or simultaneous iron and sulfate reduction are lacking for marine sediments. Furthermore, most of these studies were made in temperate sediments and little is known about the substrates for sulfate reducers in permanently cold sediments, which account for >90% of the ocean floor [5]. We investigated the relative contributions of iron reduction and sulfate reduction to the terminal oxidation of organic carbon and the importance of acetate, lactate, propionate, and isobutyrate as electron donors for iron and sulfate reduction in permanently cold, Arctic sediments from Svalbard. In the surface layer (0-2 cm) sulfate reduction accounted for 2/3 of the organic carbon oxidation (determined as DIC production), the remaining 1/3 were attributed to iron reduction. In the 5-9 cm layer sulfate reduction was the sole important terminal oxidation step. The contribution of acetate to terminal oxidation was determined by radiotracer incubation as well as from the accumulation after the inhibition of sulfate reduction by selenate. The rates determined with the two methods varied by less than 20%. Acetate turnover, determined with the tracer incubations, accounted for 10 and 40% of

  18. Cloning and properties of the Salmonella typhimurium tricarboxylate transport operon in Escherichia coli

    International Nuclear Information System (INIS)

    Widenhorn, K.A.; Boos, W.; Somers, J.M.; Kay, W.W.

    1988-01-01

    The tricarboxylate transport operon (tctI) was cloned in Escherichia coli as a 12-kilobase (kb) fragment from an EcoRI library of the Salmonella typhimurium chromosome in λgtWES. It was further subcloned as a 12-kb fragment into pACYC184 and as an 8-kb fragment into pBR322. By insertional mutagenesis mediated by λTn5, restriction mapping, and phenotypic testing, the tctI operon was localized to a 4.5-kb region. The tctC gene which encodes a periplasmic binding protein (C-protein) was located near the center of the insert. E. coli/tctI clones on either multicopy or single-copy vectors grew on the same tricarboxylates as S. typhimurium, although unusually long growth lags were observed. E. coli/tctI clones exhibited similar [ 14 C] fluorocitrate transport kinetics to those of S. typhimurium, whereas E. coli alone was virtually impermeable to [ 14 C] fluorocitrate. The periplasmic C proteins (C1 and C2 isoelectric forms) were produced in prodigious quantities from the cloned strains. Motile E. coli/tctI clones were not chemotactic toward citrate, whereas tctI deletion mutants of S. typhimurium were. Taken together, these observations indicate that tctI is not an operon involved in chemotaxis

  19. Microbial sulfate reduction under sequentially acidic conditions in an upflow anaerobic packed bed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Jong, T.; Parry, D.L. [Charles Darwin University, Darwin, NT (Australia). Faculty for Educational Health & Science

    2006-07-15

    The aim of this study was to operate an upflow anaerobic packed bed reactor (UAPB) containing sulfate reducing bacteria (SRB) under acidic conditions similar to those found in acid mine drainage (AMD). The UAPB was filled with sand and operated under continuous flow at progressively lower pH and was shown to be capable of supporting sulfate reduction at pH values of 6.0, 5.0, 4.5, 4.0 and 3.5 in a synthetic medium containing 53.5 mmol l{sup -1} lactate. Sulfate reduction rates of 553-1052 mmol m{sup -3} d{sup -1} were obtained when the influent solution pH was progressively lowered from pH 6.0 to 4.0, under an optimal flow rate of 2.61 ml min{sup -1}. When the influent pH was further lowered to pH 3.5, sulfate reduction was substantially reduced with only about 1% sulfate removed at a rate of 3.35 mmol m{sup -3} d{sup -1} after 20 days of operation. However, viable SRB were recovered from the column, indicating that the SRB population was capable of surviving and metabolizing at low levels even at pH 3.5 conditions for at least 20 days. The changes in conductivity in the SRB column did not always occur with changes in pH and redox potential, suggesting that conductivity measurements may be more sensitive to SRB activity and could be used as an additional tool for monitoring SRB activity. The bioreactor containing SRB was able to reduce sulfate and generate alkalinity even when challenged with influent as low as pH 3.5, indicating that such treatment systems have potential for bioremediating highly acidic, sulfate contaminated waste waters.

  20. Reductive cleavage of chlorine from 6-chloronicotinic acid on mercury electrodes

    International Nuclear Information System (INIS)

    Ruiz Montoya, M.; Pintado, S.; Rodriguez Mellado, J.M.

    2011-01-01

    Highlights: → Dissociation constants (as pK) of 6 chloronicotinic acid (6CNA) obtained by UV-vis spectroscopy: -0.80 ± 0.05 (-COOH group) and 3.2 ± 0.1 (pyridinic nitrogen). → Electrolysis of 6CNA evidenced the reductive cleavage of chlorine from the molecule. → Kinetic parameters (Tafel slopes and reaction orders) determined at the foot of the waves. → Reduction pathways have been proposed. - Abstract: This paper presents polarographic (direct current, dc, and differential pulse, DP) and voltammetric (linear-sweep cyclic voltammetry) studies on the electroreduction of 6-chloronicotinic acid (6CNA) on mercury electrodes. In order to obtain the dissociation constants of 6CNA, UV-vis spectra were recorded as a function of pH. pK values of -0.80 ± 0.05 (-COOH group) and 3.2 ± 0.1 (pyridinic nitrogen) were obtained. The electrochemical studies were performed in the acidity range 6 M H 2 SO 4 to pH 8. Above the last pH value no signals were obtained. Electrolysis made at potentials corresponding to the limiting current of the first wave indicates that there is a reductive cleavage of chlorine from the molecule. This was confirmed by dc and DP polarografic results and also by voltammetric results. Kinetic parameters such as Tafel slopes and electrochemical reaction orders have been determined at potentials corresponding to the foot of the waves. From these results, together with those obtained by cyclic voltammetry, a reaction pathway is proposed, in which the rate-determining step of the process is the release of a chloride ion from the radical formed after the uptake of a H + ion and an electron.

  1. Reductive cleavage of chlorine from 6-chloronicotinic acid on mercury electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Montoya, M., E-mail: mmontoya@uhu.e [Departamento de Ingenieria Quimica, Quimica Fisica y Quimica Organica, Universidad de Huelva, Campus El Carmen, Facultad de Ciencias Experimentales, E-21071 Huelva (Spain); Pintado, S., E-mail: q02pibes@uco.e [Departamento de Quimica Fisica y Termodinamica Aplicada, Universidad de Cordoba, Campus Universitario de Rabanales, edificio ' Marie Curie' ., E-14014 Cordoba (Spain); Rodriguez Mellado, J.M., E-mail: jmrodriguez@uco.e [Departamento de Quimica Fisica y Termodinamica Aplicada, Universidad de Cordoba, Campus Universitario de Rabanales, edificio ' Marie Curie' ., E-14014 Cordoba (Spain)

    2011-04-30

    Highlights: Dissociation constants (as pK) of 6 chloronicotinic acid (6CNA) obtained by UV-vis spectroscopy: -0.80 {+-} 0.05 (-COOH group) and 3.2 {+-} 0.1 (pyridinic nitrogen). Electrolysis of 6CNA evidenced the reductive cleavage of chlorine from the molecule. Kinetic parameters (Tafel slopes and reaction orders) determined at the foot of the waves. Reduction pathways have been proposed. - Abstract: This paper presents polarographic (direct current, dc, and differential pulse, DP) and voltammetric (linear-sweep cyclic voltammetry) studies on the electroreduction of 6-chloronicotinic acid (6CNA) on mercury electrodes. In order to obtain the dissociation constants of 6CNA, UV-vis spectra were recorded as a function of pH. pK values of -0.80 {+-} 0.05 (-COOH group) and 3.2 {+-} 0.1 (pyridinic nitrogen) were obtained. The electrochemical studies were performed in the acidity range 6 M H{sub 2}SO{sub 4} to pH 8. Above the last pH value no signals were obtained. Electrolysis made at potentials corresponding to the limiting current of the first wave indicates that there is a reductive cleavage of chlorine from the molecule. This was confirmed by dc and DP polarografic results and also by voltammetric results. Kinetic parameters such as Tafel slopes and electrochemical reaction orders have been determined at potentials corresponding to the foot of the waves. From these results, together with those obtained by cyclic voltammetry, a reaction pathway is proposed, in which the rate-determining step of the process is the release of a chloride ion from the radical formed after the uptake of a H{sup +} ion and an electron.

  2. Photochemical Study of Silver Nanoparticles Formed from the Reduction of Silver Ions by Humic Acid

    Science.gov (United States)

    Leslie, Renee M.

    This study focuses on the ability of silver ions and humic acid to form silver nanoparticles in the presence of UV and visible light. Silver nanoparticles have a number of industrial applications due primarily to their antimicrobial properties, but these properties pose an environmental threat. Silver nanoparticles can directly disrupt sensitive ecosystems by harming bacteria. Consumption of silver nanoparticles results in silver ions and silver nanoparticles entering waterways; the presence of silver ions raises the question of whether nanoparticles can reform in environmental waters. As our data show, silver nanoparticles can form from the reduction of silver ions by humic acid after irradiation with UV and visible light. In order to better understand the mechanism of these naturally synthesized silver nanoparticles, we investigated the effects of reactant concentration, experimental conditions and presence of ions/reactive species. We monitored silver nanoparticle growth with UV-visible spectroscopy. The evolution in time of nanoparticle size was monitored by dynamic light scattering (DLS).

  3. Kinetics of oxygen reduction reaction at electrochemically fabricated tin-palladium bimetallic electrocatalyst in acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Miah, Md. Rezwan, E-mail: mrmche@yahoo.co [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Mail Box G1-5, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Masud, Jahangir [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Mail Box G1-5, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Ohsaka, Takeo, E-mail: ohsaka@echem.titech.ac.j [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Mail Box G1-5, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)

    2010-12-15

    In the present article, oxygen reduction reaction (ORR) at electrochemically fabricated tin-palladium (Sn-Pd) bimetallic electrocatalyst-modified glassy carbon (GC) electrode (Sn-Pd/GC electrode) in acidic media is addressed. Hydrodynamic voltammetric measurements were employed with a view to evaluating various kinetic parameters of the ORR at the Sn-Pd/GC electrode. The obtained results obviously demonstrated that the Sn-Pd bimetallic electrocatalyt substantially promoted the activity of the GC electrode and drove the ORR through an exclusive one-step four-electron pathway forming H{sub 2}O as the final product.

  4. Kinetics of oxygen reduction reaction at electrochemically fabricated tin-palladium bimetallic electrocatalyst in acidic media

    International Nuclear Information System (INIS)

    Miah, Md. Rezwan; Masud, Jahangir; Ohsaka, Takeo

    2010-01-01

    In the present article, oxygen reduction reaction (ORR) at electrochemically fabricated tin-palladium (Sn-Pd) bimetallic electrocatalyst-modified glassy carbon (GC) electrode (Sn-Pd/GC electrode) in acidic media is addressed. Hydrodynamic voltammetric measurements were employed with a view to evaluating various kinetic parameters of the ORR at the Sn-Pd/GC electrode. The obtained results obviously demonstrated that the Sn-Pd bimetallic electrocatalyt substantially promoted the activity of the GC electrode and drove the ORR through an exclusive one-step four-electron pathway forming H 2 O as the final product.

  5. Poly(N-isopropylacrylamide-co-methacrylic acid microgel stabilized copper nanoparticles for catalytic reduction of nitrobenzene

    Directory of Open Access Journals (Sweden)

    Farooqi Zahoor H.

    2015-09-01

    Full Text Available Poly(N-isopropylacrylamide-co-methacrylic acid microgels [p(NIPAM-co-MAAc] were synthesized by precipitation polymerization of N-isopropylacrylamide and methacrylic acid in aqueous medium. These microgels were characterized by dynamic light scattering and Fourier transform infrared spectroscopy. These microgels were used as micro-reactors for in situ synthesis of copper nanoparticles using sodium borohydride (NaBH4 as reducing agent. The hybrid microgels were used as catalysts for the reduction of nitrobenzene in aqueous media. The reaction was performed with different concentrations of cat­alyst and reducing agent. A linear relationship was found between apparent rate constant (kapp and amount of catalyst. When the amount of catalyst was increased from 0.13 to 0.76 mg/mL then kapp was increased from 0.03 to 0.14 min-1. Activation parameters were also determined by performing reaction at two different temperatures. The catalytic process has been discussed in terms of energy of activation, enthalpy of activation and entropy of activation. The synthesized particles were found to be stable even after 14 weeks and showed catalytic activity for the reduction of nitrobenzene.

  6. Microbial sulfate reduction and metal attenuation in pH 4 acid mine water

    Directory of Open Access Journals (Sweden)

    Alpers Charles N

    2007-10-01

    Full Text Available Abstract Sediments recovered from the flooded mine workings of the Penn Mine, a Cu-Zn mine abandoned since the early 1960s, were cultured for anaerobic bacteria over a range of pH (4.0 to 7.5. The molecular biology of sediments and cultures was studied to determine whether sulfate-reducing bacteria (SRB were active in moderately acidic conditions present in the underground mine workings. Here we document multiple, independent analyses and show evidence that sulfate reduction and associated metal attenuation are occurring in the pH-4 mine environment. Water-chemistry analyses of the mine water reveal: (1 preferential complexation and precipitation by H2S of Cu and Cd, relative to Zn; (2 stable isotope ratios of 34S/32S and 18O/16O in dissolved SO4 that are 2–3 ‰ heavier in the mine water, relative to those in surface waters; (3 reduction/oxidation conditions and dissolved gas concentrations consistent with conditions to support anaerobic processes such as sulfate reduction. Scanning electron microscope (SEM analyses of sediment show 1.5-micrometer, spherical ZnS precipitates. Phospholipid fatty acid (PLFA and denaturing gradient gel electrophoresis (DGGE analyses of Penn Mine sediment show a high biomass level with a moderately diverse community structure composed primarily of iron- and sulfate-reducing bacteria. Cultures of sediment from the mine produced dissolved sulfide at pH values near 7 and near 4, forming precipitates of either iron sulfide or elemental sulfur. DGGE coupled with sequence and phylogenetic analysis of 16S rDNA gene segments showed populations of Desulfosporosinus and Desulfitobacterium in Penn Mine sediment and laboratory cultures.

  7. Microbial sulfate reduction and metal attenuation in pH 4 acid mine water

    Science.gov (United States)

    Church, C.D.; Wilkin, R.T.; Alpers, Charles N.; Rye, R.O.; Blaine, R.B.

    2007-01-01

    Sediments recovered from the flooded mine workings of the Penn Mine, a Cu-Zn mine abandoned since the early 1960s, were cultured for anaerobic bacteria over a range of pH (4.0 to 7.5). The molecular biology of sediments and cultures was studied to determine whether sulfate-reducing bacteria (SRB) were active in moderately acidic conditions present in the underground mine workings. Here we document multiple, independent analyses and show evidence that sulfate reduction and associated metal attenuation are occurring in the pH-4 mine environment. Water-chemistry analyses of the mine water reveal: (1) preferential complexation and precipitation by H2S of Cu and Cd, relative to Zn; (2) stable isotope ratios of 34S/32S and 18O/16O in dissolved SO4 that are 2-3 ??? heavier in the mine water, relative to those in surface waters; (3) reduction/oxidation conditions and dissolved gas concentrations consistent with conditions to support anaerobic processes such as sulfate reduction. Scanning electron microscope (SEM) analyses of sediment show 1.5-micrometer, spherical ZnS precipitates. Phospholipid fatty acid (PLFA) and denaturing gradient gel electrophoresis (DGGE) analyses of Penn Mine sediment show a high biomass level with a moderately diverse community structure composed primarily of iron- and sulfate-reducing bacteria. Cultures of sediment from the mine produced dissolved sulfide at pH values near 7 and near 4, forming precipitates of either iron sulfide or elemental sulfur. DGGE coupled with sequence and phylogenetic analysis of 16S rDNA gene segments showed populations of Desulfosporosinus and Desulfitobacterium in Penn Mine sediment and laboratory cultures. ?? 2007 Church et al; licensee BioMed Central Ltd.

  8. Kinetics modelling of the concentrated nitric acid reduction on 304L stainless steel

    International Nuclear Information System (INIS)

    Benoit, Marie

    2016-01-01

    In France, the spent nuclear fuel reprocessing involves the use of nitric acid at various concentrations and temperatures. The corrosiveness of these nitric mixtures leads to the use of corrosion resistant materials such as austenitic stainless steels (SS), which naturally forms a protective oxide layer under those conditions. The goal of this work is to study the influence of the passive layer on the mechanism and kinetics of concentrated nitric acid reduction reaction (NRR). We firstly focused on a single step in the reduction reaction (Fe(III)/Fe(II) couple in acidic solution) on passivated zirconium with different oxide layer thicknesses. The electrochemical impedance spectroscopy can lead to estimate the semiconducting properties of the film: the space charge capacitance (from the Mott-Schottky equation) allowed to estimate the number of charge carriers in the oxide. We experimentally compare the NRR on gold (on which no passive layer is formed) and SS, respectively. The chemical composition (chromium enrichment) and thickness of the SS passive layer are characterized by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS), and the mechanism and kinetics of NRR are studied by chrono-amperometry and EIS. On gold electrode, two mechanisms occur successively as a function of cathodic overpotential. at lower over potentials (0.85≤E/SHE≤1.15 V) we propose that NRR follows the Vetter's mechanism, whereas at higher over potentials (0.65≤E/ESH≤ 0.85 V), Schmid's mechanism may occur. On SS, the presence of the passive layer slows down the NRR by a factor 10"4. Moreover, depending on the experimental conditions (4 M to 8 M, 40 C to 100 C) Schmid's mechanism may occur or not in the potential range investigated. Finally, based on the EIS results, we propose a quantitative modelling of the NRR mechanism on stainless steel electrodes. (author) [fr

  9. Sulfate reduction at low pH to remediate acid mine drainage

    International Nuclear Information System (INIS)

    Sánchez-Andrea, Irene; Sanz, Jose Luis; Bijmans, Martijn F.M.; Stams, Alfons J.M.

    2014-01-01

    Highlights: • Acid mine drainage (AMD) is an important environmental concern. • Remediation through biological sulfate reduction and metal recovery can be applied for AMD. • Microbial community composition has a major impact on the performance of bioreactors to treat AMD. • Acidophilic SRB are strongly influenced by proton, sulfide and organic acids concentration. - Abstract: Industrial activities and the natural oxidation of metallic sulfide-ores produce sulfate-rich waters with low pH and high heavy metals content, generally termed acid mine drainage (AMD). This is of great environmental concern as some heavy metals are highly toxic. Within a number of possibilities, biological treatment applying sulfate-reducing bacteria (SRB) is an attractive option to treat AMD and to recover metals. The process produces alkalinity, neutralizing the AMD simultaneously. The sulfide that is produced reacts with the metal in solution and precipitates them as metal sulfides. Here, important factors for biotechnological application of SRB such as the inocula, the pH of the process, the substrates and the reactor design are discussed. Microbial communities of sulfidogenic reactors treating AMD which comprise fermentative-, acetogenic- and SRB as well as methanogenic archaea are reviewed

  10. Sulfate reduction at low pH to remediate acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Andrea, Irene, E-mail: irene.sanchezandrea@wur.nl [Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen (Netherlands); Sanz, Jose Luis [Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Bijmans, Martijn F.M. [Wetsus, Centre of Sustainable Water Technology, P.O. Box 1113, 8900 CC Leeuwarden (Netherlands); Stams, Alfons J.M. [Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen (Netherlands); IBB – Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga (Portugal)

    2014-03-01

    Highlights: • Acid mine drainage (AMD) is an important environmental concern. • Remediation through biological sulfate reduction and metal recovery can be applied for AMD. • Microbial community composition has a major impact on the performance of bioreactors to treat AMD. • Acidophilic SRB are strongly influenced by proton, sulfide and organic acids concentration. - Abstract: Industrial activities and the natural oxidation of metallic sulfide-ores produce sulfate-rich waters with low pH and high heavy metals content, generally termed acid mine drainage (AMD). This is of great environmental concern as some heavy metals are highly toxic. Within a number of possibilities, biological treatment applying sulfate-reducing bacteria (SRB) is an attractive option to treat AMD and to recover metals. The process produces alkalinity, neutralizing the AMD simultaneously. The sulfide that is produced reacts with the metal in solution and precipitates them as metal sulfides. Here, important factors for biotechnological application of SRB such as the inocula, the pH of the process, the substrates and the reactor design are discussed. Microbial communities of sulfidogenic reactors treating AMD which comprise fermentative-, acetogenic- and SRB as well as methanogenic archaea are reviewed.

  11. Fatty Acid Biosynthesis Inhibition Increases Reduction Potential in Neuronal Cells under Hypoxia

    Directory of Open Access Journals (Sweden)

    Stephen A Brose

    2016-11-01

    Full Text Available Recently, we have reported a novel neuronal specific pathway for adaptation to hypoxia through increased fatty acid (FA biosynthesis (FAS followed by esterification into lipids. However, the biological role of this pathway under hypoxia remains to be elucidated. In the presented study, we have tested our hypothesis that activation of FAS maintains reduction potential and reduces lactoacidosis in neuronal cells under hypoxia. To address this hypothesis, we measured the effect of FAS inhibition on NADH2+/NAD+ and NADPH2+/NADP+ ratios, and lactic acid levels in neuronal SH-SY5Y cells exposed to normoxic and hypoxic conditions. FAS inhibitors, TOFA (inhibits Acetyl-CoA carboxylase and cerulenin (inhibits FA synthase, increased NADH2+/NAD+ and NADPH2+/NADP+ ratios under hypoxia. Further, FAS inhibition increased lactic acid under both normoxic and hypoxic conditions, and caused cytotoxicity under hypoxia but not normoxia. These results indicate that FA may serve as hydrogen acceptors under hypoxia, thus supporting oxidation reactions including anaerobic glycolysis. These findings may help to identify a radically different approach to attenuate hypoxia related pathophysiology in the nervous system including stroke.

  12. Fatty Acid Biosynthesis Inhibition Increases Reduction Potential in Neuronal Cells under Hypoxia.

    Science.gov (United States)

    Brose, Stephen A; Golovko, Svetlana A; Golovko, Mikhail Y

    2016-01-01

    Recently, we have reported a novel neuronal specific pathway for adaptation to hypoxia through increased fatty acid (FA) biosynthesis followed by esterification into lipids. However, the biological role of this pathway under hypoxia remains to be elucidated. In the presented study, we have tested our hypothesis that activation of FA synthesis maintains reduction potential and reduces lactoacidosis in neuronal cells under hypoxia. To address this hypothesis, we measured the effect of FA synthesis inhibition on [Formula: see text]/NAD + and [Formula: see text]/NADP + ratios, and lactic acid levels in neuronal SH-SY5Y cells exposed to normoxic and hypoxic conditions. FA synthesis inhibitors, TOFA (inhibits Acetyl-CoA carboxylase) and cerulenin (inhibits FA synthase), increased [Formula: see text]/NAD + and [Formula: see text]/NADP + ratios under hypoxia. Further, FA synthesis inhibition increased lactic acid under both normoxic and hypoxic conditions, and caused cytotoxicity under hypoxia but not normoxia. These results indicate that FA may serve as hydrogen acceptors under hypoxia, thus supporting oxidation reactions including anaerobic glycolysis. These findings may help to identify a radically different approach to attenuate hypoxia related pathophysiology in the nervous system including stroke.

  13. Thin layer spectroelectrochemical studies of pertechnetate reduction on the gold electrodes in acidic media

    International Nuclear Information System (INIS)

    Chotkowski, M.; Czerwiński, A.

    2014-01-01

    The electroreduction of pertechnetate ions has been examined in sulfuric acid solutions (0.5 M ÷ 4 M H 2 SO 4 ) using rotating disc electrodes (Au-RDE) and optically transparent thin layer spectroelectrochemical cells (Au/RVC-OTTLE). Soluble Tc(III,IV) species with absorption bands at 502 nm were found to be formed during the reduction of TcO 4 − . The hydrodynamic experiments (Au-RDE) have shown the influence of the acidity of the solution on the activation energy of the electroreduction of the pertechnetate ions to technetium(III,IV) species. The value of the activation energy calculated for limiting current was found to increase from 12.6 ± 1.1 kJ mol −1 for 4 M H 2 SO 4 to 20.1 ± 0.8 kJ mol −1 for 0.5 M H 2 SO 4 . Such an effect suggests an influence of the acid concentration on the structure of obtained products, which are soluble or insoluble Tc species. Thin layer spectroelectrochemical experiments allowed calculation of the redox standard potentials for Tc 2 O 2 3+ /TcO(OH) (aq) system which was found to be equal to 0.255 V vs. Ag,AgCl (KClsat.)

  14. Conjugated linoleic acid supplementation caused reduction of perilipin1 and aberrant lipolysis in epididymal adipose tissue

    International Nuclear Information System (INIS)

    Cai, Demin; Li, Hongji; Zhou, Bo; Han, Liqiang; Zhang, Xiaomei; Yang, Guoyu; Yang, Guoqing

    2012-01-01

    Highlights: ► Conjugated linoleic acid supplementation suppresses perilipin1 in epididymal fat. ► Conjugated linoleic acid inhibits promoter activity of perilipin1 in 3T3-L1 cells. ► Conjugated linoleic acids elevate basal but blunt hormone-stimulated lipolysis. -- Abstract: Perilipin1, a coat protein of lipid droplet, plays a key role in adipocyte lipolysis and fat formation of adipose tissues. However, it is not clear how the expression of perilipin1 is affected in the decreased white adipose tissues (WAT) of mice treated with dietary supplement of conjugated linoleic acids (CLA). Here we obtained lipodystrophic mice by dietary administration of CLA which exhibited reduced epididymal (EPI) WAT, aberrant adipocytes and decreased expression of leptin in this tissue. We found both transcription and translation of perilipin1 was suppressed significantly in EPI WAT of CLA-treated mice compared to that of control mice. The gene expression of negative regulator tumor necrosis factor α (TNFα) and the positive regulator Peroxisome Proliferator-Activated Receptor-γ (PPARγ) of perilipin1 was up-regulated and down-regulated, respectively. In cultured 3T3-L1 cells the promoter activity of perilipin1 was dramatically inhibited in the presence of CLA. Using ex vivo experiment we found that the basal lipolysis was elevated but the hormone-stimulated lipolysis blunted in adipose explants of CLA-treated mice compared to that of control mice, suggesting that the reduction of perilipin1 in white adipose tissues may at least in part contribute to CLA-mediated alternation of lipolysis of WAT.

  15. Conjugated linoleic acid supplementation caused reduction of perilipin1 and aberrant lipolysis in epididymal adipose tissue

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Demin [College of Animal Sciences and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, Henan Province, People' s Republic of China (China); Li, Hongji [Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou 450002, Henan Province, People' s Republic of China (China); Zhou, Bo [College of Animal Sciences and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, Henan Province, People' s Republic of China (China); Han, Liqiang [Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou 450002, Henan Province, People' s Republic of China (China); Zhang, Xiaomei [College of Animal Sciences and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, Henan Province, People' s Republic of China (China); Yang, Guoyu, E-mail: haubiochem@163.com [Key Laboratory of Animal Biochemistry and Nutrition, Ministry of Agriculture, Henan Agricultural University, Zhengzhou 450002, Henan Province, People' s Republic of China (China); Yang, Guoqing, E-mail: gqyang@yeah.net [College of Animal Sciences and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, Henan Province, People' s Republic of China (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Conjugated linoleic acid supplementation suppresses perilipin1 in epididymal fat. Black-Right-Pointing-Pointer Conjugated linoleic acid inhibits promoter activity of perilipin1 in 3T3-L1 cells. Black-Right-Pointing-Pointer Conjugated linoleic acids elevate basal but blunt hormone-stimulated lipolysis. -- Abstract: Perilipin1, a coat protein of lipid droplet, plays a key role in adipocyte lipolysis and fat formation of adipose tissues. However, it is not clear how the expression of perilipin1 is affected in the decreased white adipose tissues (WAT) of mice treated with dietary supplement of conjugated linoleic acids (CLA). Here we obtained lipodystrophic mice by dietary administration of CLA which exhibited reduced epididymal (EPI) WAT, aberrant adipocytes and decreased expression of leptin in this tissue. We found both transcription and translation of perilipin1 was suppressed significantly in EPI WAT of CLA-treated mice compared to that of control mice. The gene expression of negative regulator tumor necrosis factor {alpha} (TNF{alpha}) and the positive regulator Peroxisome Proliferator-Activated Receptor-{gamma} (PPAR{gamma}) of perilipin1 was up-regulated and down-regulated, respectively. In cultured 3T3-L1 cells the promoter activity of perilipin1 was dramatically inhibited in the presence of CLA. Using ex vivo experiment we found that the basal lipolysis was elevated but the hormone-stimulated lipolysis blunted in adipose explants of CLA-treated mice compared to that of control mice, suggesting that the reduction of perilipin1 in white adipose tissues may at least in part contribute to CLA-mediated alternation of lipolysis of WAT.

  16. Organics Characterization Of DWPF Alternative Reductant Simulants, Glycolic Acid, And Antifoam 747

    Energy Technology Data Exchange (ETDEWEB)

    White, T. L. [Savannah River Site (SRS), Aiken, SC (United States); Wiedenman, B. J. [Savannah River Site (SRS), Aiken, SC (United States); Lambert, D. P. [Savannah River Site (SRS), Aiken, SC (United States); Crump, S. L. [Savannah River Site (SRS), Aiken, SC (United States); Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States); Papathanassiu, A. E. [Catholic University of America Vitreous State Laboratory, Washington, DC (United States); Kot, W. K. [Catholic University of America Vitreous State Laboratory, Washington, DC (United States); Pegg, I. L. [Catholic University of America Vitreous State Laboratory, Washington, DC (United States)

    2013-10-01

    The present study examines the fate of glycolic acid and other organics added in the Chemical Processing Cell (CPC) of the Defense Waste Processing Facility (DWPF) as part of the glycolic alternate flowsheet. Adoption of this flowsheet is expected to provide certain benefits in terms of a reduction in the processing time, a decrease in hydrogen generation, simplification of chemical storage and handling issues, and an improvement in the processing characteristics of the waste stream including an increase in the amount of nitrate allowed in the CPC process. Understanding the fate of organics in this flowsheet is imperative because tank farm waste processed in the CPC is eventually immobilized by vitrification; thus, the type and amount of organics present in the melter feed may affect optimal melt processing and the quality of the final glass product as well as alter flammability calculations on the DWPF melter off gas. To evaluate the fate of the organic compounds added as the part of the glycolic flowsheet, mainly glycolic acid and antifoam 747, samples of simulated waste that was processed using the DWPF CPC protocol for tank farm sludge feed were generated and analyzed for organic compounds using a variety of analytical techniques at the Savannah River National Laboratory (SRNL). These techniques included Ion Chromatography (IC), Gas Chromatography-Mass Spectrometry (GC-MS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), and Nuclear Magnetic Resonance (NMR) Spectroscopy. A set of samples were also sent to the Catholic University of America Vitreous State Laboratory (VSL) for analysis by NMR Spectroscopy at the University of Maryland, College Park. Analytical methods developed and executed at SRNL collectively showed that glycolic acid was the most prevalent organic compound in the supernatants of Slurry Mix Evaporator (SME) products examined. Furthermore, the studies suggested that commercially available glycolic acid contained minor amounts

  17. Organics Characterization Of DWPF Alternative Reductant Simulants, Glycolic Acid, And Antifoam 747

    International Nuclear Information System (INIS)

    White, T. L.; Wiedenman, B. J.; Lambert, D. P.; Crump, S. L.; Fondeur, F. F.; Papathanassiu, A. E.; Kot, W. K.; Pegg, I. L.

    2013-01-01

    The present study examines the fate of glycolic acid and other organics added in the Chemical Processing Cell (CPC) of the Defense Waste Processing Facility (DWPF) as part of the glycolic alternate flowsheet. Adoption of this flowsheet is expected to provide certain benefits in terms of a reduction in the processing time, a decrease in hydrogen generation, simplification of chemical storage and handling issues, and an improvement in the processing characteristics of the waste stream including an increase in the amount of nitrate allowed in the CPC process. Understanding the fate of organics in this flowsheet is imperative because tank farm waste processed in the CPC is eventually immobilized by vitrification; thus, the type and amount of organics present in the melter feed may affect optimal melt processing and the quality of the final glass product as well as alter flammability calculations on the DWPF melter off gas. To evaluate the fate of the organic compounds added as the part of the glycolic flowsheet, mainly glycolic acid and antifoam 747, samples of simulated waste that was processed using the DWPF CPC protocol for tank farm sludge feed were generated and analyzed for organic compounds using a variety of analytical techniques at the Savannah River National Laboratory (SRNL). These techniques included Ion Chromatography (IC), Gas Chromatography-Mass Spectrometry (GC-MS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), and Nuclear Magnetic Resonance (NMR) Spectroscopy. A set of samples were also sent to the Catholic University of America Vitreous State Laboratory (VSL) for analysis by NMR Spectroscopy at the University of Maryland, College Park. Analytical methods developed and executed at SRNL collectively showed that glycolic acid was the most prevalent organic compound in the supernatants of Slurry Mix Evaporator (SME) products examined. Furthermore, the studies suggested that commercially available glycolic acid contained minor amounts

  18. Field-scale modeling of acidity production and remediation efficiency during in situ reductive dechlorination

    Science.gov (United States)

    Brovelli, A.; Robinson, C. E.; Barry, D. A.; Gerhard, J.

    2009-12-01

    Enhanced reductive dechlorination is a viable technology for in situ remediation of chlorinated solvent DNAPL source areas. Although in recent years increased understanding of this technology has led to more rapid dechlorination rates, complete dechlorination can be hindered by unfavorable conditions. Hydrochloric acid produced from dechlorination and organic acids generated from electron donor fermentation can lead to significant groundwater acidification. Adverse pH conditions can inhibit the activity of dehalogenating microorganisms and thus slow or stall the remediation process. The extent of acidification likely to occur at a contaminated site depends on a number of factors including (1) the extent of dechlorination, (2) the pH-sensitivity of dechlorinating bacteria, and (3) the geochemical composition of the soil and water, in particular the soil’s natural buffering capacity. The substantial mass of solvents available for dechlorination when treating DNAPL source zones means that these applications are particularly susceptible to acidification. In this study a reactive transport biogeochemical model was developed to investigate the chemical and physical parameters that control the build-up of acidity and subsequent remediation efficiency. The model accounts for the site water chemistry, mineral precipitation and dissolution kinetics, electron donor fermentation, gas phase formation, competing electron-accepting processes (e.g., sulfate and iron reduction) and the sensitivity of microbial processes to pH. Confidence in the model was achieved by simulating a well-documented field study, for which the 2-D field scale model was able to reproduce long-term variations of pH, and the concurrent build up of reaction products. Sensitivity analyses indicated the groundwater flow velocity is able to reduce acidity build-up when the rate of advection is comparable or larger than the rate of dechlorination. The extent of pH change is highly dependent on the presence of

  19. Enhanced succinic acid production in Aspergillus saccharolyticus by heterologous expression of fumarate reductase from Trypanosoma brucei

    DEFF Research Database (Denmark)

    Yang, Lei; Lübeck, Mette; Ahring, Birgitte K.

    2015-01-01

    production medium as well as the complete medium, but the measured enzyme activities were different depending on the media. Furthermore, a soluble NADH-dependent fumarate reductase gene (frd) from Trypanosoma brucei was inserted and expressed in A. saccharolyticus. The expression of the frd gene led......Aspergillus saccharolyticus exhibits great potential as a cell factory for industrial production of dicarboxylic acids. In the analysis of the organic acid profile, A. saccharolyticus was cultivated in an acid production medium using two different pH conditions. The specific activities...... of the enzymes, pyruvate carboxylase (PYC), malate dehydrogenase (MDH), and fumarase (FUM), involved in the reductive tricarboxylic acid (rTCA) branch, were examined and compared in cells harvested from the acid production medium and a complete medium. The results showed that ambient pH had a significant impact...

  20. Kinetics and mechanism of reduction of diazonium salts with hypophosphorous acid

    International Nuclear Information System (INIS)

    Levit, A.F.; Kiprianova, L.A.; Gragerov, I.P.

    1975-01-01

    A kinetic study has been made of reduction of a series of diazonium salts n-XC 6 H 4 N 2 + BF 4 - (X=OCH 3 , CH 3 , H, Cl, Br, NO 2 ) by subphosphorus acid using the NMR technique. The intensity of NMR signals has been used to measure the rate of formation of the reaction products-benzene or substituted benzenes. The reaction with phenyldiazonium has been studied in the most detailed way. Under conditions when propagation stages are suppressed (in the presence of benzoquinone) chemical polarization of nuclei is observed in benzene which is formed at the initiation stage. The polarization indicates the formation of C 6 H 5 radicals in this stage. It is interesting as the first observation of the chemical polarization of nuclei in the initiation stage of chain reactions

  1. Reduction of 3 alpha-hydroxy-5 beta-chol-6-en-24-oic acid to lithocholic acid in rats

    International Nuclear Information System (INIS)

    Kimura, K.; Ogura, M.

    1988-01-01

    After [24- 14 C]delta 6-lithocholic acid was injected into the cecum of rats, [ 14 C]lithocholic acid was identified as a metabolite in feces. When the labeled delta 6-bile acid was injected intraperitoneally into bile-fistula rats, radioactivity excreted in bile was contained most abundantly in the taurine-conjugated fraction of bile acids. In the fraction, taurine conjugate of [ 14 C]delta 6-lithocholic acid but of neither [ 14 C]lithocholic acid nor other bile acids was found. The results showed that [24- 14 C]delta 6-lithocholic acid was reduced to [ 14 C]lithocholic acid by the intestinal flora but not by the liver, which, however, was capable of conjugating delta 6-lithocholic acid with taurine

  2. Bioelectrochemical reduction of volatile fatty acids in anaerobic digestion effluent for the production of biofuels.

    Science.gov (United States)

    Kondaveeti, Sanath; Min, Booki

    2015-12-15

    This study proves for the first time the feasibility of biofuel production from anaerobic digestion effluent via bioelectrochemical cell operation at various applied cell voltages (1.0, 1.5 and 2.0 V). An increase in cell voltage from 1 to 2 V resulted in more reduction current generation (-0.48 to -0.78 mA) at a lowered cathode potential (-0.45 to -0.84 mV vs Ag/AgCl). Various alcohols were produced depending on applied cell voltages, and the main products were butanol, ethanol, and propanol. Hydrogen and methane production were also observed in the headspace of the cell. A large amount of lactic acid was unexpectedly formed at all conditions, which might be the primary cause of the limited biofuel production. The addition of neutral red (NR) to the system could increase the cathodic reduction current, and thus more biofuels were produced with an enhanced alcohol formation compared to without a mediator. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage.

    Science.gov (United States)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A

    2016-11-05

    This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu(2+). Sulfate, sulfide, Cu(2+) and pH were monitored throughout the experiment of 123d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7mg SO4(2-) d(-1)) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu(2+) removal were observed in the endogenous control. In algae amended-columns, Cu(2+) was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Substantial Humic Acid Adsorption to Activated Carbon Air Cathodes Produces a Small Reduction in Catalytic Activity.

    Science.gov (United States)

    Yang, Wulin; Watson, Valerie J; Logan, Bruce E

    2016-08-16

    Long-term operation of microbial fuel cells (MFCs) can result in substantial degradation of activated carbon (AC) air-cathode performance. To examine a possible role in fouling from organic matter in water, cathodes were exposed to high concentrations of humic acids (HA). Cathodes treated with 100 mg L(-1) HA exhibited no significant change in performance. Exposure to 1000 mg L(-1) HA decreased the maximum power density by 14% (from 1310 ± 30 mW m(-2) to 1130 ± 30 mW m(-2)). Pore blocking was the main mechanism as the total surface area of the AC decreased by 12%. Minimization of external mass transfer resistances using a rotating disk electrode exhibited only a 5% reduction in current, indicating about half the impact of HA adsorption was associated with external mass transfer resistance and the remainder was due to internal resistances. Rinsing the cathodes with deionized water did not restore cathode performance. These results demonstrated that HA could contribute to cathode fouling, but the extent of power reduction was relatively small in comparison to large mass of humics adsorbed. Other factors, such as biopolymer attachment, or salt precipitation, are therefore likely more important contributors to long-term fouling of MFC cathodes.

  5. Theoretical Insight into the Trends that Guide the Electrochemical Reduction of Carbon Dioxide to Formic Acid.

    Science.gov (United States)

    Yoo, Jong Suk; Christensen, Rune; Vegge, Tejs; Nørskov, Jens K; Studt, Felix

    2016-02-19

    The electrochemical reduction (electroreduction) of CO2 to formic acid (HCOOH) and its competing reactions, that is, the electroreduction of CO2 to CO and the hydrogen evolution reaction (HER), on twenty-seven different metal surfaces have been investigated using density functional theory (DFT) calculations. Owing to a strong linear correlation between the free energies of COOH* and H*, it seems highly unlikely that the electroreduction of CO2 to HCOOH via the COOH* intermediate occurs without a large fraction of the current going to HER. On the other hand, the selective electroreduction of CO2 to HCOOH seems plausible if the reaction occurs via the HCOO* intermediate, as there is little correlation between the free energies of HCOO* and H*. Lead and silver surfaces are found to be the most promising monometallic catalysts showing high faradaic efficiencies for the electroreduction of CO2 to HCOOH with small overpotentials. Our methodology is widely applicable, not only to metal surfaces, but also to other classes of materials enabling the computational search for electrocatalysts for CO2 reduction to HCOOH. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Plasma Jet Printing and in Situ Reduction of Highly Acidic Graphene Oxide.

    Science.gov (United States)

    Dey, Avishek; Krishnamurthy, Satheesh; Bowen, James; Nordlund, Dennis; Meyyappan, M; Gandhiraman, Ram P

    2018-05-23

    Miniaturization of electronic devices and the advancement of Internet of Things pose exciting challenges to develop technologies for patterned deposition of functional nanomaterials. Printed and flexible electronic devices and energy storage devices can be embedded onto clothing or other flexible surfaces. Graphene oxide (GO) has gained much attention in printed electronics due its solution processability, robustness, and high electrical conductivity in the reduced state. Here, we introduce an approach to print GO films from highly acidic suspensions with in situ reduction using an atmospheric pressure plasma jet. Low-temperature plasma of a He and H 2 mixture was used successfully to reduce a highly acidic GO suspension (pH < 2) in situ during deposition. This technique overcomes the multiple intermediate steps required to increase the conductivity of deposited GO. X-ray spectroscopic studies confirmed that the reaction intermediates and the concentration of oxygen functionalities bonded to GO have been reduced significantly by this approach without any additional steps. Moreover, the reduced GO films showed enhanced conductivity. Hence, this technique has a strong potential for printing conducting patterns of GO for a range of large-scale applications.

  7. Catalyst evaluation for oxygen reduction reaction in concentrated phosphoric acid at elevated temperatures

    Science.gov (United States)

    Hu, Yang; Jiang, Yiliang; Jensen, Jens Oluf; Cleemann, Lars N.; Li, Qingfeng

    2018-01-01

    Phosphoric acid is the common electrolyte for high-temperature polymer electrolyte fuel cells (HT-PEMFCs) that have advantages such as enhanced CO tolerance and simplified heat and water management. The currently used rotating disk electrode technique is limited to tests in dilute solutions at low temperatures and hence is not suitable for catalyst evaluation for HT-PEMFCs. In this study, we have designed and constructed a half-cell setup to measure the intrinsic activities of catalysts towards the oxygen reduction reaction (ORR) in conditions close to HT-PEMFC cathodes. By optimization of the hydrophobic characteristics of electrodes and the catalyst layer thickness, ORR activities of typical Pt/C catalysts are successfully measured in concentrated phosphoric acid at temperatures above 100 °C. In terms of mass-specific activities, the catalyst exhibits about two times higher activity in the half-cell electrode than that observed in fuel cells, indicating the feasibility of the technique as well as the potential for further improvement of fuel cell electrode performance.

  8. Overview of ATX-101 (Deoxycholic Acid Injection): A Nonsurgical Approach for Reduction of Submental Fat.

    Science.gov (United States)

    Dayan, Steven H; Humphrey, Shannon; Jones, Derek H; Lizzul, Paul F; Gross, Todd M; Stauffer, Karen; Beddingfield, Frederick C

    2016-11-01

    In 2015, ATX-101 (deoxycholic acid injection; Kybella in the United States and Belkyra in Canada; Kythera Biopharmaceuticals, Inc., Westlake Village, CA [an affiliate of Allergan plc, Dublin, Ireland]) was approved as a first-in-class injectable drug for improvement in the appearance of moderate to severe convexity or fullness associated with submental fat. ATX-101 has been evaluated in a clinical development program that included 18 Phase 1 to 3 studies supporting the current indication. Since 2007, the toxicity and safety profiles of ATX-101 have been characterized in numerous preclinical studies, its pharmacokinetics, pharmacodynamics, and optimal treatment paradigm have been defined in multiple Phase 1 and 2 studies, and its efficacy and clinical safety have been confirmed in 4 large Phase 3 trials (2 conducted in Europe and 2 in the United States and Canada [REFINE-1 and REFINE-2]). As subcutaneous injection of deoxycholic acid has been shown to cause adipocytolysis, the reduction in submental fat achieved after ATX-101 treatment is expected to be long lasting. This prediction is confirmed by data from long-term follow-up studies of up to 4 years after last treatment with ATX-101, which demonstrate that the treatment response is maintained over time in most subjects. ATX-101 offers a durable, minimally invasive alternative to liposuction and surgery for addressing submental fullness.

  9. Acid Rock Drainage or Not—Oxidative vs. Reductive Biofilms—A Microbial Question

    Directory of Open Access Journals (Sweden)

    Margarete Kalin

    2018-05-01

    Full Text Available Measures to counteract Acid Rock Drainage (ARD generation need to start at the mineral surface, inhibiting mineral-oxidizing, acidophilic microbes. Laboratory and long-term field tests with pyrite-containing mining wastes—where carbonaceous phosphate mining waste (CPMW was added—resulted in low acidity and near neutral drainage. The effect was reproducible and confirmed by several independent research groups. The improved drainage was shown to involve an organic coating, likely a biofilm. The biofilm formation was confirmed when CPMW was added to lignite coal waste with an initial pH of 1. Forty-five days after the addition, the coal waste was dominated by heterotrophic microorganisms in biofilms. Reviewing the scientific literature provides ample support that CPMW has physical and chemical characteristics which can induce a strong inhibitory effect on sulphide oxidation by triggering the formation of an organic coating, a biofilm, over the mineral surface. CPMW characteristics provide the cornerstone of a new technology which might lead to reduction of sulphide oxidation in mine wastes. A hypothesis for testing this technology is presented. The use of such a technology could result in an economical and sustainable approach to mine waste and water management.

  10. Simultaneous Reduction and Functionalization of Graphene Oxide by 4-Hydrazinobenzenesulfonic Acid for Polymer Nanocomposites

    Directory of Open Access Journals (Sweden)

    Song-Jie Qiao

    2016-02-01

    Full Text Available Graphene oxide (GO was functionalized and reduced simultaneously by a new reductant, 4-hydrazinobenzenesulfonic acid (HBS, with a one-step and environmentally friendly process. The hydrophilic sulfonic acid group in HBS was grafted onto the surface of GO through a covalent bond. The successful preparation of HBS reduced GO (HBS-rGO was testified by scanning electron microscope (SEM, X-ray diffraction (XRD, Raman spectroscopy, Fourier transform infrared spectra (FTIR, X-ray photoelectron spectroscopic (XPS and thermogravimetric analysis (TGA. The interlayer space of HBS-rGO was increased to 1.478 nm from 0.751 nm for GO, resulting in a subdued Van der Waals’ force between layers and less possibility to form aggregations. The aqueous dispersibility of graphene was improved to 13.49 mg/mL from 0.58 mg/mL after the functionalization. The viscosity of the epoxy resin based HBS-rGO composite could be regulated by an adjustment of the content of HBS-rGO. This study provides a new and applicable approach for the preparation of hydrophilic functionalized graphene, and makes it possible for the application of graphene in some functional polymer nanocomposites, such as specialty water-based coatings.

  11. Temporary reduction of radiation does not permanently reduce flavonoid glycosides and phenolic acids in red lettuce.

    Science.gov (United States)

    Becker, Christine; Kläring, Hans-Peter; Kroh, Lothar W; Krumbein, Angelika

    2013-11-01

    Applying transparent daytime screens in greenhouses in cool seasons reduces the amount of energy needed for heating, but also the solar radiation available for crops. This can reduce yield and product quality of leafy vegetables because of constrained photosynthesis and altered biosynthesis. To study this, we cultivated five-week old red leaf lettuce (Lactuca sativa L.) for four weeks in growth chambers under a photosynthetic photon flux density (PPFD) of 225 and 410 μmol m(-2) s(-1), respectively. Some plants were exchanged between radiation intensities after two weeks. We investigated the concentration of five flavonoid glycosides, three caffeic acid derivatives, reducing sugars as well as plant growth. Remarkably, no significant influence of radiation intensity on the concentration of phenolic acids or anthocyanin glycosides was observed. In contrast, quercetin and luteolin glycoside concentration was between 14 and 34% lower in plants growing under lower compared to higher PPFD. Already after two weeks of cultivation, plants grown under lower PPFD contained less quercetin and luteolin glycosides but they completely compensated if subsequently transferred to higher PPFD until harvest. Hence, marketable lettuce heads which experienced temporary shading followed by an unshaded phase did not contain lower concentrations of flavonoid glycosides or phenolic acids. Also, there was no reduction of head mass in this variant. Our results suggest that saving energy in early growth stages is feasible without losses in yield or health promoting phenolic substances. In addition, there was a close correlation between the concentration of reducing sugars and some flavonoid glycosides, indicating a close metabolic connection between their biosynthesis and the availability of carbohydrates. Copyright © 2013 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

  12. Single Atomic Iron Catalysts for Oxygen Reduction in Acidic Media: Particle Size Control and Thermal Activation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hanguang; Hwang, Sooyeon; Wang, Maoyu; Feng, Zhenxing; Karakalos, Stavros; Luo, Langli; Qiao, Zhi; Xie, Xiaohong; Wang, Chongmin; Su, Dong; Shao, Yuyan; Wu, Gang (BNL); (Oregon State U.); (SC); (PNNL); (Buffalo)

    2017-09-26

    It remains a grand challenge to replace platinum group metal (PGM) catalysts with earth-abundant materials for the oxygen reduction reaction (ORR) in acidic media, which is crucial for large-scale deployment of proton exchange membrane fuel cells (PEMFCs). Here, we report a high-performance atomic Fe catalyst derived from chemically Fe-doped zeolitic imidazolate frameworks (ZIFs) by directly bonding Fe ions to imidazolate ligands within 3D frameworks. Although the ZIF was identified as a promising precursor, the new synthetic chemistry enables the creation of well-dispersed atomic Fe sites embedded into porous carbon without the formation of aggregates. The size of catalyst particles is tunable through synthesizing Fe-doped ZIF nanocrystal precursors in a wide range from 20 to 1000 nm followed by one-step thermal activation. Similar to Pt nanoparticles, the unique size control without altering chemical properties afforded by this approach is able to increase the number of PGM-free active sites. The best ORR activity is measured with the catalyst at a size of 50 nm. Further size reduction to 20 nm leads to significant particle agglomeration, thus decreasing the activity. Using the homogeneous atomic Fe model catalysts, we elucidated the active site formation process through correlating measured ORR activity with the change of chemical bonds in precursors during thermal activation up to 1100 °C. The critical temperature to form active sites is 800 °C, which is associated with a new Fe species with a reduced oxidation number (from Fe3+ to Fe2+) likely bonded with pyridinic N (FeN4) embedded into the carbon planes. Further increasing the temperature leads to continuously enhanced activity, linked to the rise of graphitic N and Fe–N species. The new atomic Fe catalyst has achieved respectable ORR activity in challenging acidic media (0.5 M H2SO4), showing a half-wave potential of 0.85 V vs RHE and leaving only a 30 mV gap with Pt/C (60 μgPt/cm2). Enhanced stability

  13. ESR study of /sup 99/Tc(II) complex formed by reduction of ammonium pertechnetate with ascorbic acid in concentrated hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, T; Tsuchihashi, N; Ogata, T

    1987-07-30

    Paramagnetic /sup 99/Tc complex formed by the reduction of ammonium pertechnetate by ascorbic acid with excess sodium nitrite in concentrated hydrochloric acid was investigated by ESR technique. This complex had total electron spin S=1/2 and the obtained ESR parameters are 2.032, 2.043; and 264, 108 gauss, respectively. It was concluded that the formed species was low spin /sup 99/Tc(II) complex. (author) 13 refs.

  14. Moessbauer spectroscopic evidence for iron(III) complexation and reduction in acidic aqueous solutions of indole-3-butyric acid

    International Nuclear Information System (INIS)

    Kovacs, K.; Kuzmann, E.; Vertes, A.; Kamnev, A.A.; Shchelochkov, A.G.; Medzihradszky-Schweiger, H.; Mink, J.; Hungarian Academy of Sciences, Budapest

    2004-01-01

    Moessbauer spectroscopic studies were carried out in acidic (pH 2.3) 57 Fe III nitrate containing aqueous solutions of indole-3-butyric acid (IBA), rapidly frozen in liquid nitrogen at various periods of time after mixing the reagents. The data obtained show that in solution in the presence of IBA, iron(III) forms a complex with a dimeric structure characterised by a quadrupole doublet, whereas without IBA under similar conditions iron(III) exhibits a broad spectral feature due to a slow paramagnetic spin relaxation which, at liquid nitrogen temperature, results in a large anomalous line broadening (or, at T = 4.2 K, in a hyperfine magnetic splitting). The spectra of 57 Fe III +IBA solutions, kept at ambient temperature under aerobic conditions for increasing periods of time before freezing, contained a gradually increasing contribution of a component with a higher quadrupole splitting. The Moessbauer parameters for that component are typical for iron(II) aquo complexes, thus showing that under these conditions gradual reduction of iron(III) occurs, so that the majority (85%) of dissolved iron(III) is reduced within 2 days. The Moessbauer parameters for the iron(III)-IBA complex in aqueous solution and in the solid state (separated from the solution by filtration) were found to be similar, which may indicate that the dissolved and solid complexes have the same composition and/or iron(III) coordination environment. For the solid complex, the data of elemental analysis suggest the following composition of the dimer: [L 2 Fe-(OH) 2 -FeL 2 ] (where L is indole-3-butyrate). This structure is also in agreement with the data of infrared spectroscopic study of the complex reported earlier, with the side-chain carboxylic group in indole-3-butyrate as a bidentate ligand. The Moessbauer parameters for the solid 57 Fe III -IBA complex at T = 80 K and its acetone solution rapidly frozen in liquid nitrogen were virtually identical, which indicates that the complex retains its

  15. Fluoxetine prevents the memory deficits and reduction in hippocampal cell proliferation caused by valproic acid.

    Science.gov (United States)

    Welbat, Jariya Umka; Sangrich, Preeyanuch; Sirichoat, Apiwat; Chaisawang, Pornthip; Chaijaroonkhanarak, Wunnee; Prachaney, Parichat; Pannangrong, Wanassanun; Wigmore, Peter

    2016-12-01

    Valproic acid (VPA), a commonly used antiepileptic drug, has been reported to cause cognitive impairments in patients. In a previous study, using a rodent model, we showed that VPA treatment impaired cognition which was associated with a reduction in the cell proliferation required for hippocampal neurogenesis. The antidepressant fluoxetine has been shown to increase hippocampal neurogenesis and to reverse the memory deficits found in a number of pathological conditions. In the present study we investigated the protective effects of fluoxetine treatment against the impairments in memory and hippocampal cell proliferation produced by VPA. Male Sprague Dawley rats received daily treatment with fluoxetine (10mg/kg) by oral gavage for 21days. Some rats were co-administered with VPA (300mg/kg, twice daily i.p. injections) for 14days from day 8 to day 21 of the fluoxetine treatment. Spatial memory was tested using the novel object location (NOL) test. The number of proliferating cells present in the sub granular zone of the dentate gyrus was quantified using Ki67 immunohistochemistry at the end of the experiment. Levels of the receptor Notch1, the neurotrophic factor BDNF and the neural differentiation marker DCX were determined by Western blotting. VPA-treated rats showed memory deficits, a decrease in the number of proliferating cells in the sub granular zone and decreases in the levels of Notch1 and BDNF but not DCX compared to control animals. These changes in behavior, cell proliferation and Notch1 and BDNF were prevented in animals which had received both VPA and fluoxetine. Rats receiving fluoxetine alone did not show a significant difference in the number of proliferating cells or behavior compared to controls. These results demonstrated that the spatial memory deficits and reduction of cell proliferation produced by VPA can be ameliorated by the simultaneous administration of the antidepressant fluoxetine. Crown Copyright © 2016. Published by Elsevier B

  16. Abscisic Acid Induces Rapid Reductions in Mesophyll Conductance to Carbon Dioxide.

    Directory of Open Access Journals (Sweden)

    Giuseppe Sorrentino

    Full Text Available The rate of photosynthesis (A of plants exposed to water deficit is a function of stomatal (gs and mesophyll (gm conductance determining the availability of CO2 at the site of carboxylation within the chloroplast. Mesophyll conductance often represents the greatest impediment to photosynthetic uptake of CO2, and a crucial determinant of the photosynthetic effects of drought. Abscisic acid (ABA plays a fundamental role in signalling and co-ordination of plant responses to drought; however, the effect of ABA on gm is not well-defined. Rose, cherry, olive and poplar were exposed to exogenous ABA and their leaf gas exchange parameters recorded over a four hour period. Application with ABA induced reductions in values of A, gs and gm in all four species. Reduced gm occurred within one hour of ABA treatment in three of the four analysed species; indicating that the effect of ABA on gm occurs on a shorter timescale than previously considered. These declines in gm values associated with ABA were not the result of physical changes in leaf properties due to altered turgor affecting movement of CO2, or caused by a reduction in the sub-stomatal concentration of CO2 (Ci. Increased [ABA] likely induces biochemical changes in the properties of the interface between the sub-stomatal air-space and mesophyll layer through the actions of cooporins to regulate the transport of CO2. The results of this study provide further evidence that gm is highly responsive to fluctuations in the external environment, and stress signals such as ABA induce co-ordinated modifications of both gs and gm in the regulation of photosynthesis.

  17. Reductive glutamine metabolism by IDH1 mediates lipogenesis under hypoxia

    Science.gov (United States)

    Metallo, Christian M.; Gameiro, Paulo A.; Bell, Eric L.; Mattaini, Katherine R.; Yang, Juanjuan; Hiller, Karsten; Jewell, Christopher M.; Johnson, Zachary R.; Irvine, Darrell J.; Guarente, Leonard; Kelleher, Joanne K.; Vander Heiden, Matthew G.; Iliopoulos, Othon; Stephanopoulos, Gregory

    2013-01-01

    Acetyl coenzyme A (AcCoA) is the central biosynthetic precursor for fatty acid synthesis and protein acetylation. In the conventional view of mammalian cell metabolism, AcCoA is primarily generated from glucose-derived pyruvate through the citrate shuttle and adenosine triphosphate citrate lyase (ACL) in the cytosol1-3. However, proliferating cells that exhibit aerobic glycolysis and those exposed to hypoxia convert glucose to lactate at near stoichiometric levels, directing glucose carbon away from the tricarboxylic acid cycle (TCA) and fatty acid synthesis4. Although glutamine is consumed at levels exceeding that required for nitrogen biosynthesis5, the regulation and utilization of glutamine metabolism in hypoxic cells is not well understood. Here we show that human cells employ reductive metabolism of alpha-ketoglutarate (αKG) to synthesize AcCoA for lipid synthesis. This isocitrate dehydrogenase 1 (IDH1) dependent pathway is active in most cell lines under normal culture conditions, but cells grown under hypoxia rely almost exclusively on the reductive carboxylation of glutamine-derived αKG for de novo lipogenesis. Furthermore, renal cell lines deficient in the von Hippel-Lindau (VHL) tumor suppressor protein preferentially utilize reductive glutamine metabolism for lipid biosynthesis even at normal oxygen levels. These results identify a critical role for oxygen in regulating carbon utilization in order to produce AcCoA and support lipid synthesis in mammalian cells. PMID:22101433

  18. Single Atomic Iron Catalysts for Oxygen Reduction in Acidic Media: Particle Size Control and Thermal Activation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hanguang [Department; Hwang, Sooyeon [Center; Wang, Maoyu [School; Feng, Zhenxing [School; Karakalos, Stavros [Department; Luo, Langli [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Qiao, Zhi [Department; Xie, Xiaohong [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Wang, Chongmin [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Su, Dong [Center; Shao, Yuyan [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Wu, Gang [Department

    2017-09-26

    To significantly reduce the cost of proton exchange membrane (PEM) fuel cells, current Pt must be replaced by platinum-metal-group (PGM)-free catalysts for the oxygen reduction reaction (ORR) in acid. We report here a new class of high-performance atomic iron dispersed carbon catalysts through controlled chemical doping of iron ions into zinc-zeolitic imidazolate framework (ZIF), a type of metal-organic framework (MOF). The novel synthetic chemistry enables accurate size control of Fe-doped ZIF catalyst particles with a wide range from 20 to 1000 nm without changing chemical properties, which provides a great opportunity to increase the density of active sites that is determined by the particle size. We elucidated the active site formation mechanism by correlating the chemical and structural changes with thermal activation process for the conversion from Fe-N4 complex containing hydrocarbon networks in ZIF to highly active FeNx sites embedded into carbon. A temperature of 800oC was identified as the critical point to start forming pyridinic nitrogen doping at the edge of the graphitized carbon planes. Further increasing heating temperature to 1100oC leads to increase of graphitic nitrogen, generating possible synergistic effect with FeNx sites to promote ORR activity. The best performing catalyst, which has well-defined particle size around 50 nm and abundance of atomic FeNx sites embedded into carbon structures, achieve a new performance milestone for the ORR in acid including a half-wave potential of 0.85 V vs RHE and only 20 mV loss after 10,000 cycles in O2 saturated H2SO4 electrolyte. The new class PGM-free catalyst with approaching activity to Pt holds great promise for future PEM fuel cells.

  19. The reduction of plutonium (IV) and neptunium (VI) ions by N,N-ethyl (hydroxyethyl) hydroxylamine in nitric acid

    International Nuclear Information System (INIS)

    Koltunov, V.S.; Baranov, S.M.; Mezhov, E.A.; Taylor, R.J.; May, I.

    1999-01-01

    The kinetics of the reduction of neptunium (VI) and plutonium (IV) ions in nitric acid solution by a new rapid salt free reductant, N,N-ethyl (hydroxyethyl) hydroxylamine, have been studied and rate equations determined. Under equivalent conditions, both Np(VI) and Pu(IV) are reduced faster than by the related reagent, N,N-diethyl hydroxylamine, and it is suggested that this is due to the introduction of the hydroxy group into the reductant molecule. Possible reaction mechanisms have been suggested to account for the observed reaction stoichiometry. (orig.)

  20. Reductive Leaching Kinetics of Low Grade Manganese Deposits in H2SO4 Solution Using Malonic Acid as Reducing Agent

    OpenAIRE

    Taysser Lasheen; S. A. Abu Elenein; W. A. Saleh; A. H Orabi; D. A Ismaiel

    2014-01-01

    A leaching process was developed to extract manganese and metal values from Alloga manganese concentrate. The preferential leaching process was achieved through reductive leaching in dilute sulfuric acid medium with malonic acid as the reducing agent. Leaching parameters were optimized as 1.0 M H2SO4, 10% malonic acid in solid/liquid ratio 1:10 for 90 min at 80 C and using ore ground to – 74 µm. Under these conditions, the leaching efficiency of manganese reaches 97%, whilst iron dissolution ...

  1. Kinetics and mechanism of reduction of iron(iii) kojic acid complex by hydroquinone and l-cysteine

    International Nuclear Information System (INIS)

    Hussain, Z.; Perviaz, M.; Kazmi, S.A.; Johnson, A.S.; Offiong, O.E.

    2014-01-01

    The effect of pH on the kinetics of reduction of iron(III) kojic acid complex by hydroquinone (H/sub 2/Q) and L-cysteine (L-Cys) was studied in the pH range of 2.34 - 4.03 for H/sub 2/Q and 3.04 - 5.5 for L-cysteine at ionic strength of 0.5 M and at 35 degree C. The pseudo-first order rate constants for the reduction of Fe(KA)3 by L-cysteine and hydroquinone increase linearly with increasing reductant concentration, indicating first-order kinetics in reductant concentration. However, whereas the rate of reduction by H2Q increases with increasing pH, an opposite trend was observed in the case of reduction by L-cysteine. Plausible rate laws and mechanisms have been proposed in line with these observations. Activation parameters (delta H no and delta S no) were evaluated for the reduction of iron (III) kojic acid complex by cysteine and the values obtained are 35.25 kJmol-1, -141.4 JK-1mol-1 and 28.14 kJmol-1 , 161.2 JK-1mol-1 for pH 4.5 and 3.52 respectively. (author)

  2. Mucus reduction promotes acetyl salicylic acid-induced small intestinal mucosal injury in rats.

    Science.gov (United States)

    Suyama, Yosuke; Handa, Osamu; Naito, Yuji; Takayama, Shun; Mukai, Rieko; Ushiroda, Chihiro; Majima, Atsushi; Yasuda-Onozawa, Yuriko; Higashimura, Yasuki; Fukui, Akifumi; Dohi, Osamu; Okayama, Tetsuya; Yoshida, Naohisa; Katada, Kazuhiro; Kamada, Kazuhiro; Uchiyama, Kazuhiko; Ishikawa, Takeshi; Takagi, Tomohisa; Konishi, Hideyuki; Itoh, Yoshito

    2018-03-25

    Acetyl salicylic acid (ASA) is a useful drug for the secondary prevention of cerebro-cardiovascular diseases, but it has adverse effects on the small intestinal mucosa. The pathogenesis and prophylaxis of ASA-induced small intestinal injury remain unclear. In this study, we focused on the intestinal mucus, as the gastrointestinal tract is covered by mucus, which exhibits protective effects against various gastrointestinal diseases. ASA was injected into the duodenum of rats, and small intestinal mucosal injury was evaluated using Evans blue dye. To investigate the importance of mucus, Polysorbate 80 (P80), an emulsifier, was used before ASA injection. In addition, rebamipide, a mucus secretion inducer in the small intestine, was used to suppress mucus reduction in the small intestine of P80-administered rats. The addition of P80 reduced the mucus and exacerbated the ASA-induced small intestinal mucosal injury. Rebamipide significantly suppressed P80-reduced small intestinal mucus and P80-increased intestinal mucosal lesions in ASA-injected rats, demonstrating that mucus is important for the protection against ASA-induced small intestinal mucosal injury. These results provide new insight into the mechanism of ASA-induced small intestinal mucosal injury. Mucus secretion-increasing therapy might be useful in preventing ASA-induced small intestinal mucosal injury. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. D-penicillamine-templated copper nanoparticles via ascorbic acid reduction as a mercury ion sensor.

    Science.gov (United States)

    Lin, Shu Min; Geng, Shuo; Li, Na; Li, Nian Bing; Luo, Hong Qun

    2016-05-01

    Mercury ion is one of the most hazardous metal pollutants that can cause deleterious effects on human health and the environment even at low concentrations. It is necessary to develop new mercury detection methods with high sensitivity, specificity and rapidity. In this study, a novel and green strategy for synthesizing D-penicillamine-capped copper nanoparticles (DPA-CuNPs) was successfully established by a chemical reduction method, in which D-penicillamine and ascorbic acid were used as stabilizing agent and reducing agent, respectively. The as-prepared DPA-CuNPs showed strong red fluorescence and had a large Stoke's shift (270nm). Scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, fluorescence spectroscopy, and ultraviolet-visible spectrophotometry were utilized to elucidate the possible fluorescence mechanism, which could be aggregation-induced emission effect. Based on the phenomenon that trace mercury ion can disperse the aggregated DPA-CuNPs, resulting in great fluorescence quench of the system, a sensitive and selective assay for mercury ion in aqueous solution with the DPA-CuNPs was developed. Under optimum conditions, this assay can be applied to the quantification of Hg(2+) in the 1.0-30μM concentration range and the detection limit (3σ/slope) is 32nM. The method was successfully applied to determine Hg(2+) in real water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Reduction Potentials and Acidity Constants of Mn Superoxide Dismutase Calculated by QM/MM Free-Energy Methods

    Czech Academy of Sciences Publication Activity Database

    Heimdal, J.; Kaukonen, M.; Srnec, Martin; Rulíšek, Lubomír; Ryde, U.

    2011-01-01

    Roč. 12, č. 17 (2011), s. 3337-3347 ISSN 1439-4235 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : acidity constants * enzymes * free-energy * perturbation * molecular modelling * reduction potentials Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.412, year: 2011

  5. Analysis of tellurium-silicon alloys. Part 1. Determination of tellurium by the reduction from perchloric acid solution

    International Nuclear Information System (INIS)

    Teperek, J.

    1977-01-01

    When 100-150 mg of tellurium is dissolved in the solution containing 20 cm 3 72 wt.% of perchloric acid, the reduction of tellurium to elementary form is possible only after adding 60-100 milimoles of HCl. The reduction is performed by adding 1 cm 3 of saturated sodium pyrosulphite solution (Na 2 S 2 O 5 ) and 10 cm 3 of 10 wt.% hydrazine hydrochloride solution (N 2 H 4 .2HCl) to 80-90 cm 3 of cold solution of Te in HClO 4 -HCl mixture. The reduction is completed after 3-5 min. of boiling. When 150-200 mg sample of Te-Si alloy is dissolved in 20 cm 3 of hot 72% per chloric acid, the separation of components is reached. Tellurium can be determinated in filtrate by proposed procedure with high accuracy and precision. (author)

  6. Low Temperature Selective Catalytic Reduction of Nitrogen Oxides in Production of Nitric Acid by the Use of Liquid

    Directory of Open Access Journals (Sweden)

    Kabljanac, Ž.

    2011-11-01

    Full Text Available This paper presents the application of low-temperature selective catalytic reduction of nitrous oxides in the tail gas of the dual-pressure process of nitric acid production. The process of selective catalytic reduction is carried out using the TiO2/WO3 heterogeneous catalyst applied on a ceramic honeycomb structure with a high geometric surface area per volume. The process design parameters for nitric acid production by the dual-pressure procedure in a capacity range from 75 to 100 % in comparison with designed capacity for one production line is shown in the Table 1. Shown is the effectiveness of selective catalytic reduction in the temperature range of the tail gas from 180 to 230 °C with direct application of liquid ammonia, without prior evaporation to gaseous state. The results of inlet and outlet concentrations of nitrous oxides in the tail gas of the nitric acid production process are shown in Figures 1 and 2. Figure 3 shows the temperature dependence of the selective catalytic reduction of nitrous oxides expressed as NO2in the tail gas of nitric acid production with the application of a constant mass flow of liquid ammonia of 13,0 kg h-1 and average inlet mass concentration of the nitrous oxides expressed as NO2of 800,0 mgm-3 during 100 % production capacity. The specially designed liquid-ammonia direct-dosing system along with the effective homogenization of the tail gas resulted in emission levels of nitrous oxides expressed as NO2 in tail gas ranging from 100,0 to 185,0 mg m-3. The applied low-temperature selective catalytic reduction of the nitrous oxides in the tail gases by direct use of liquid ammonia is shown in Figure 4. It is shown that low-temperature selective catalytic reduction with direct application of liquid ammonia opens a new opportunity in the reduction of nitrous oxide emissions during nitric acid production without the risk of dangerous ammonium nitrate occurring in the process of subsequent energy utilization of

  7. Reduction of water consumption in the dynamic acid leaching process of uranium

    International Nuclear Information System (INIS)

    Chocron, M.; Arias, M.J.; Avato, A.M.; Díaz, V.A.

    2013-01-01

    In 2006 the Argentine state announced a plan to reactivate the nuclear sector. As a result of this decision, the National Atomic Energy Commission (CNEA) resumed its research in uranium mining for Argentine deposits. The first step was the study of the leaching process, mainly the dynamic leaching. In this work the influence of the reduction of the water content in the dynamic leaching process in acid medium, at laboratory scale and under batch operating conditions, on the main operating parameters (concentration of the leaching reagent, the oxidizing reagent and The reaction temperature). The percentages of pulp solids studied in the dynamic leaching were 53% and 66% w / w. For the tests uranium-molybdenum ores of the sandstone type were used. Two different working schemes were used to study the different operating parameters. In the tests carried out with 53% of solid in pulp, the parameters were studied individually (varying one parameter at a time), while working with a pulp of 66% solids, the study of the parameters was performed by a Factorial design of two levels of three variables, which in addition to studying the dependence of the different parameters allowed to analyze how they influence each other. During the leaching tests with 66% solids content in pulp, changes in the geometric and dynamic conditions of the system were necessary because of the poor mixing observed when using the same agitation conditions used in the leaching tests with 53% solids in pulp. When comparing the tests for both solids content conditions (53% and 66% w / w), similar extraction yields were observed for both uranium and molybdenum (more than 90% for uranium and more than 80% for The molybdenum). As a final result, the process water consumption (380 liters of water per ton of ore) is reduced by more than 50% by working with pulps of 66% w / w of solids, obtaining acceptable extraction yields and, as an additional, reducing The consumption of the leaching reagent. (author)

  8. BP, Cardiovascular Disease, and Death in the Folic Acid for Vascular Outcome Reduction in Transplantation Trial

    Science.gov (United States)

    John, Alin; Weir, Matthew R.; Smith, Stephen R.; Hunsicker, Lawrence; Kasiske, Bertram L.; Kusek, John W.; Bostom, Andrew; Ivanova, Anastasia; Levey, Andrew S.; Solomon, Scott; Pesavento, Todd; Weiner, Daniel E.

    2014-01-01

    The optimal BP level in kidney transplant recipients remains uncertain. This post hoc analysis of the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial cohort assessed associations of BP with a pooled cardiovascular disease (CVD) outcome and with all-cause mortality. In 3474 prevalent kidney transplant patients, mean age was 52±9 years, 63% were men, 76% were white, 20% had a history of CVD, 40% had a history of diabetes mellitus, and the median time since transplant was 4.1 years (25th to 75th percentiles, 1.7–7.4); mean systolic BP was 136±20 mmHg and mean diastolic BP was 79±12 mmHg. There were 497 CVD events and 406 deaths. After adjustment for demographic and transplant characteristics and CVD risk factors, each 20-mmHg increase in baseline systolic BP associated with a 32% increase in subsequent CVD risk (hazard ratio [HR], 1.32; 95% confidence interval [95% CI], 1.19 to 1.46) and a 13% increase in mortality risk (HR, 1.13; 95% CI, 1.01 to 1.27). Similarly, after adjustment, at diastolic BP levels70 mmHg, there was no significant relationship between diastolic BP and outcomes. Higher systolic BP strongly and independently associated with increased risk of CVD and all-cause mortality, without evidence of a J shape, whereas only lower levels of diastolic BP associated with increased risk of CVD and death in this trial. PMID:24627349

  9. Dietary stearic acid leads to a reduction of visceral adipose tissue in athymic nude mice.

    Directory of Open Access Journals (Sweden)

    Ming-Che Shen

    Full Text Available Stearic acid (C18:0 is a long chain dietary saturated fatty acid that has been shown to reduce metastatic tumor burden. Based on preliminary observations and the growing evidence that visceral fat is related to metastasis and decreased survival, we hypothesized that dietary stearic acid may reduce visceral fat. Athymic nude mice, which are used in models of human breast cancer metastasis, were fed a stearic acid, linoleic acid (safflower oil, or oleic acid (corn oil enriched diet or a low fat diet ad libitum. Total body weight did not differ significantly between dietary groups over the course of the experiment. However visceral fat was reduced by ∼70% in the stearic acid fed group compared to other diets. In contrast total body fat was only slightly reduced in the stearic acid diet fed mice when measured by dual-energy x-ray absorptiometry and quantitative magnetic resonance. Lean body mass was increased in the stearic acid fed group compared to all other groups by dual-energy x-ray absorptiometry. Dietary stearic acid significantly reduced serum glucose compared to all other diets and increased monocyte chemotactic protein-1 (MCP-1 compared to the low fat control. The low fat control diet had increased serum leptin compared to all other diets. To investigate possible mechanisms whereby stearic acid reduced visceral fat we used 3T3L1 fibroblasts/preadipocytes. Stearic acid had no direct effects on the process of differentiation or on the viability of mature adipocytes. However, unlike oleic acid and linoleic acid, stearic acid caused increased apoptosis (programmed cell death and cytotoxicity in preadipocytes. The apoptosis was, at least in part, due to increased caspase-3 activity and was associated with decreased cellular inhibitor of apoptosis protein-2 (cIAP2 and increased Bax gene expression. In conclusion, dietary stearic acid leads to dramatically reduced visceral fat likely by causing the apoptosis of preadipocytes.

  10. Aerosol pH buffering in the southeastern US: Fine particles remain highly acidic despite large reductions in sulfate

    Science.gov (United States)

    Weber, R. J.; Guo, H.; Russell, A. G.; Nenes, A.

    2015-12-01

    pH is a critical aerosol property that impacts many atmospheric processes, including biogenic secondary organic aerosol formation, gas-particle phase partitioning, and mineral dust or redox metal mobilization. Particle pH has also been linked to adverse health effects. Using a comprehensive data set from the Southern Oxidant and Aerosol Study (SOAS) as the basis for thermodynamic modeling, we have shown that particles are currently highly acidic in the southeastern US, with pH between 0 and 2. Sulfate and ammonium are the main acid-base components that determine particle pH in this region, however they have different sources and their concentrations are changing. Over 15 years of network data show that sulfur dioxide emission reductions have resulted in a roughly 70 percent decrease in sulfate, whereas ammonia emissions, mainly link to agricultural activities, have been largely steady, as have gas phase ammonia concentrations. This has led to the view that particles are becoming more neutralized. However, sensitivity analysis, based on thermodynamic modeling, to changing sulfate concentrations indicates that particles have remained highly acidic over the past decade, despite the large reductions in sulfate. Furthermore, anticipated continued reductions of sulfate and relatively constant ammonia emissions into the future will not significantly change particle pH until sulfate drops to clean continental background levels. The result reshapes our expectation of future particle pH and implies that atmospheric processes and adverse health effects linked to particle acidity will remain unchanged for some time into the future.

  11. Reductive dechlorination of trichloroacetic acid (TCAA) by electrochemical process over Pd-In/Al_2O_3 catalyst

    International Nuclear Information System (INIS)

    Liu, Yanzhen; Mao, Ran; Tong, Yating; Lan, Huachun; Zhang, Gong; Liu, Huijuan; Qu, Jiuhui

    2017-01-01

    Highlights: • TCAA was efficiently removed by Pd-In/Al_2O_3 based electro-reductive process. • The active species for TCAA electroreduction involved electron (e"−) and atomic H*. • The atomic H* played a major contribution to TCAA removal. - Abstract: Electrochemical reduction treatment was found to be a promising method for dechlorination of Trichloroacetic acid (TCAA), and acceleration of electron transfer or enhancement of the concentration of atomic H* significantly improve the electrochemical dechlorination process. Bimetallic Pd-based catalysts have the unique property of simultaneously catalyzing the production of atomic H* and reducing target pollutants. Herein, a bimetallic Pd–In electrocatalyst with atomic ratio of 1:1 was evenly deposited on an Al_2O_3 substrate, and the bimetallic Pd-In structure was confirmed via X-ray photoelectron spectroscopy (XPS). Electrochemical removal of trichloroacetic acid (TCAA) by the Pd-In/Al_2O_3 catalyst was performed in a three-dimensional reactor. 94% of TCAA with the initial concentration of 500 μg L"−"1 could be degraded within 30 min under a relatively low current density (0.9 mA cm"−"2). In contrast to the presence of refractory intermediates (dichloroacetic acid (DCAA)) found in the Pd/Al_2O_3 system, TCAA could be thoroughly reduced to monochloroacetic acid (MCAA) using Pd-In/Al_2O_3 catalysts. According to scavenger experiments, an electron transfer process and atomic H* formation function both existed in the TCAA reduction process, and the enhanced indirect atomic H* reduction process (confirmed by ESR signals) played a chief role in the TCAA removal. Moreover, the synergistic effects of Pd and In were proven to be able to enhance both direct electron transfer and indirect atomic H* formation, indicating a promising prospect for bimetallic electrochemical reduction treatment.

  12. Application of Primary Abatement Technology for Reduction of N2O Emmision in Petrokemija Nitric Acid Production

    Directory of Open Access Journals (Sweden)

    Ćosić, L.

    2013-01-01

    Full Text Available Industrial nitric acid production by oxidation of gaseous ammonia with Ostwald procedure produces an unwanted by-product – colorless nitrous oxide, N2O. As emission of N2O represents a very serious problem due of its huge contribution to global warming, certain measures focused on its maximum reduction should be undertaken. Minimization of N2O emission in nitric acid production can be achieved in different parts of the process flow, depending on the applied available technologies. For the abatement of N2O emissions in Petrokemija's nitric acid production processes from the list of the best available technologies chosen were primary and secondary abatement technologies. The mentioned ensures reduction of N2O by use of improved selective heterogeneous catalysts in the step of gaseous ammonia oxidation. Precious metals in the shape of gauzes are used as selective heterogeneous catalyst in primary technology, while in the case of secondary technology the Fe2 O3 catalyst on Al2O3 support in the shape of spherical pellets is chosen. Shown is the application of primary technology for the abatement of N2O in both nitric acid production facilities and their comparison with classical heterogeneous catalyst and preparation for the installation of secondary selective catalyst. N2O emissions with the application of primary technology in both production facilities were reduced from 12 kg of N2O to 7 kg of N2O per ton of pure HNO3. With the primary reduction in N2O emissions the foundation was established for further reduction with the secondary technology to the final value of 0.7 kg of N2O per ton of pure HNO3, which represents mass concentration in the tail gas below 200 mg m-3 (at n. c.. With the applied technologies for the abatement of N2O emissions in Petrokemija's nitric acid production the future prescribed emission limit value will be satisfied.

  13. Role of dissimilatory sulfate reduction in wetlands constructed for acid coal mine drainage (AMD) treatment. Master's thesis

    International Nuclear Information System (INIS)

    Taddeo, F.J.

    1991-01-01

    Five constructed wetlands with different organic substrates were exposed to the same quantity/quality of acid mine drainage (AMD). During the 16-month exposure to AMD, all wetlands accumulated S in the forms of organic and reduced inorganic S and Fe in the form of iron sulfides. Iron sulfide and probably most of the organic S(C-bonded S) accumulation were end products of bacterial dissimilatory sulfate reduction. Results of study support the notion that sulfate reduction and accumulation of Fe sulfides contribute to Fe retention in wetlands exposed to AMD. Detailed information is provided

  14. Oxygen Reduction on Gas-Diffusion Electrodes for Phosphoric Acid Fuel Cells by a Potential Decay Method

    DEFF Research Database (Denmark)

    Li, Qingfeng; Gang, Xiao; Hjuler, Hans Aage

    1995-01-01

    The reduction of gaseous oxygen on carbon supported platinum electrodes has been studied at 150 degrees C with polarization and potential decay measurements. The electrolyte was either 100 weight percent phosphoric acid or that acid with a fluorinated additive, potassium perfluorohexanesulfonate ......6F13SO3K). The pseudo-Tafel curves of the overpotential vs. log (ii(L)/(i(L) - i)) show a two-slope behavior, probably due to different adsorption mechanisms. The potential relaxations as functions of log (t + tau) and log (-d eta/dt) have been plotted. The variations of these slopes...

  15. Heteropoly acid promoted Cu and Fe catalysts for the selective catalytic reduction of NO with ammonia

    DEFF Research Database (Denmark)

    Putluru, Siva Sankar Reddy; Mossin, Susanne L.; Riisager, Anders

    2011-01-01

    Cu/TiO2, Fe/TiO2 and heteropoly acid promoted Cu/TiO2, Fe/TiO2 catalysts were prepared and characterized by N2 physisorption, XRPD, NH3-TPD, H2-TPR and EPR. The catalysts exhibited only crystalline TiO2 phases with the active metals and promoters in highly dispersed state. The acidic properties...... activity and acidity was lower for promoted catalysts than for unpromoted catalysts. In the heteropoly acid promoted catalysts the SCR active Cu and Fe metals were protected from potassium poisons by bonding of the potassium to the Brønsted acid centres. Thus heteropoly acid promoted catalysts might...... be suitable for biomass fired power plant SCR applications....

  16. Dynamic mechanistic modeling of the multienzymatic one-pot reduction of dehydrocholic acid to 12-keto ursodeoxycholic acid with competing substrates and cofactors.

    Science.gov (United States)

    Sun, Boqiao; Hartl, Florian; Castiglione, Kathrin; Weuster-Botz, Dirk

    2015-01-01

    Ursodeoxycholic acid (UDCA) is a bile acid which is used as pharmaceutical for the treatment of several diseases, such as cholesterol gallstones, primary sclerosing cholangitis or primary biliary cirrhosis. A potential chemoenzymatic synthesis route of UDCA comprises the two-step reduction of dehydrocholic acid to 12-keto-ursodeoxycholic acid (12-keto-UDCA), which can be conducted in a multienzymatic one-pot process using 3α-hydroxysteroid dehydrogenase (3α-HSDH), 7β-hydroxysteroid dehydrogenase (7β-HSDH), and glucose dehydrogenase (GDH) with glucose as cosubstrate for the regeneration of cofactor. Here, we present a dynamic mechanistic model of this one-pot reduction which involves three enzymes, four different bile acids, and two different cofactors, each with different oxidation states. In addition, every enzyme faces two competing substrates, whereas each bile acid and cofactor is formed or converted by two different enzymes. First, the kinetic mechanisms of both HSDH were identified to follow an ordered bi-bi mechanism with EBQ-type uncompetitive substrate inhibition. Rate equations were then derived for this mechanism and for mechanisms describing competing substrates. After the estimation of the model parameters of each enzyme independently by progress curve analyses, the full process model of a simple batch-process was established by coupling rate equations and mass balances. Validation experiments of the one-pot multienzymatic batch process revealed high prediction accuracy of the process model and a model analysis offered important insight to the identification of optimum reaction conditions. © 2015 American Institute of Chemical Engineers.

  17. Study on reduction and back extraction of Pu(IV) by urea derivatives in nitric acid conditions

    International Nuclear Information System (INIS)

    Ye, G.A.; Xiao, S.T.; Yan, T.H.; Lin, R.S.; Zhu, Z.W.

    2013-01-01

    The reduction kinetics of Pu(IV) by hydroxyl-semicarbazide (HSC), hydroxyurea (HU) and di-hydroxyurea (DHU) in nitric acid solutions were investigated separately with adequate kinetic equations. In addition, counter-current cascade experiments were conducted for Pu split from U in nitric acid media using three kinds of reductant, respectively. The results show that urea derivatives as a kind of novel salt-free reductant can reduce Pu(IV) to Pu(III) rapidly in the nitric acid solutions. The stripping experimental results showed that Pu(IV) in the organic phase can be stripped rapidly to the aqueous phase by the urea derivatives, and the separation factors of plutonium /uranium can reach more than 10 4 . This indicates that urea derivatives is a kind of promising salt-free agent for uranium/plutonium separation. In addition, the complexing effect of HSC with Np(IV) was revealed, and Np(IV) can be back-extracted by HSC with a separation factor of about 20

  18. Study on reduction and back extraction of Pu(IV) by urea derivatives in nitric acid conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ye, G.A.; Xiao, S.T.; Yan, T.H.; Lin, R.S.; Zhu, Z.W. [China Institute of Atomic Energy, P.O.Box 275(26), Beijing 102413 (China)

    2013-07-01

    The reduction kinetics of Pu(IV) by hydroxyl-semicarbazide (HSC), hydroxyurea (HU) and di-hydroxyurea (DHU) in nitric acid solutions were investigated separately with adequate kinetic equations. In addition, counter-current cascade experiments were conducted for Pu split from U in nitric acid media using three kinds of reductant, respectively. The results show that urea derivatives as a kind of novel salt-free reductant can reduce Pu(IV) to Pu(III) rapidly in the nitric acid solutions. The stripping experimental results showed that Pu(IV) in the organic phase can be stripped rapidly to the aqueous phase by the urea derivatives, and the separation factors of plutonium /uranium can reach more than 10{sup 4}. This indicates that urea derivatives is a kind of promising salt-free agent for uranium/plutonium separation. In addition, the complexing effect of HSC with Np(IV) was revealed, and Np(IV) can be back-extracted by HSC with a separation factor of about 20.

  19. Probiotics Supplemented with Omega-3 Fatty Acids are More Effective for Hepatic Steatosis Reduction in an Animal Model of Obesity.

    Science.gov (United States)

    Kobyliak, Nazarii; Falalyeyeva, Tetyana; Bodnar, Petro; Beregova, Tetyana

    2017-06-01

    Today probiotics have been suggested as a treatment for the prevention of NAFLD. Omega-3 fatty acid supplementation may have beneficial effects in regulating hepatic lipid metabolism, adipose tissue function and inflammation. The present study was designed to determine whether probiotics plus omega-3 are superior to probiotics alone on the monosodium glutamate (MSG)-induced NAFLD model in rats. We included 60 rats divided into four groups, 15 animals in each. Rats of group I were intact. Newborn rats of groups II-IV were injected with MSG. The III (Symbiter) group received 2.5 ml/kg of multiprobiotic "Symbiter" containing concentrated biomass of 14 probiotic bacteria genera. The IV (Symbiter-Omega) groups received "Symbiter-Omega" combination of probiotic biomass supplemented with flax and wheat germ oil (250 mg of each, concentration of omega-3 fatty acids 1-5 %). In both interventional groups reduction in total NAS score was observed. Supplementation of alive probiotic mixture with omega-3 fatty acids lead to 20 % higher decrease in steatosis score (0.73 ± 0.11 vs 0.93 ± 0.22, p = 0.848) and reduction by 16.6 % of triglycerides content in liver as compared to probiotic alone. Our study demonstrated more pronounced reduction in hepatic steatosis and hepatic lipid accumulation after treatment with combination of alive probiotics and omega-3 as compared to probiotics alone.

  20. Waste acid/metal solution reduction and recovery by vacuum distillation

    International Nuclear Information System (INIS)

    Jones, E.O.; Wilcox, W.A.; Johnson, N.T.; Bowdish, F.W.

    1995-01-01

    Processes involving distillation under reduced pressure were developed at the Pacific Northwest Laboratory several years ago to recover spent acid solutions generated during the manufacture of nuclear fuel for the N-Reactor at the Hanford site. Following construction and testing of a pilot-plant, the technology was licensed to Viatec Recovery Systems, Inc. for commercialization. The technology developed included specialized distillation and rectification of volatile acids, removal of water and/or volatile acid from sulfuric acid, and precipitation of salts. A key feature of the Waste Acid Detoxification and Reclamation (WADR) technology is the development and use of advanced thermoplastic and fluoropolymer materials of construction in all critical process equipment. The technology was then expanded to include crystallization to recover metal salts for possible reuse. Economic and environmental advantages of the procedures include recovery of acids for reuse, simplification or elimination of the disposal of waste solutions, and possible recovery of metals. Industries expected to benefit from such applications include galvanizing, electroplating, sand leaching and any where metals are cleaned in acid solutions. Currently a modular system has been assembled for recovery of several different spent acid solutions

  1. Camelina sativa Oil Deodorization: Balance Between Free Fatty Acids and Color Reduction and Isomerized Byproducts Formation

    DEFF Research Database (Denmark)

    Hrastar, Robert; Cheong, Ling-Zhi; Xu, Xuebing

    2011-01-01

    parameters for bench-scale deodorization of camelina oil. The mathematical models generated described the effects of process parameters (temperature, steam flow, time) on several deodorization quality indicators: free fatty acids (FFA), trans fatty acids (TFA), color, and polymerized triglycerides (PTG...

  2. Alcohol production through volatile fatty acids reduction with hydrogen as electron donor by mixed cultures

    NARCIS (Netherlands)

    Steinbusch, K.J.J.; Hamelers, H.V.M.; Buisman, C.J.N.

    2008-01-01

    In this research we demonstrated a new method to produce alcohols. It was experimentally feasible to produce ethanol, propanol and butanol from solely volatile fatty acids (VFAs) with hydrogen as electron donor. In batch tests, VFAs such as acetic, propionic and butyric acids were reduced by mixed

  3. Preparation of a Carbon-Based Solid Acid Catalyst by Sulfonating Activated Carbon in a Chemical Reduction Process

    Directory of Open Access Journals (Sweden)

    Xiao-Yan Liu

    2010-10-01

    Full Text Available Sulfonated (SO3H-bearing activated carbon (AC-SO3H was synthesized by an aryl diazonium salt reduction process. The obtained material had a SO3H density of 0.64 mmol·g-1 and a specific surface area of 602 m2·g-1. The catalytic properties of AC-SO3H were compared with that of two commercial solid acid catalysts, Nafion NR50 and Amberlyst-15. In a 10-h esterification reaction of acetic acid with ethanol, the acid conversion with AC-SO3H (78% was lower than that of Amberlyst-15 (86%, which could be attributed to the fact that the SO3H density of the sulfonated carbon was lower than that of Amberlyst-15 (4.60 mmol·g-1. However, AC-SO3H exhibited comparable and even much higher catalytic activities than the commercial catalysts in the esterification of aliphatic acids with longer carbon chains such as hexanoic acid and decanoic acid, which may be due to the large specific surface area and mesoporous structures of the activated carbon. The disadvantage of AC-SO3H is the leaching of SO3H group during the reactions.

  4. Colloidal silver nanoparticles prepared by UV-light induced citrate reduction technique for the quantitative detection of uric acid

    Science.gov (United States)

    Maity, Anupam; Panda, Sovan Kumar

    2018-04-01

    Reddish-yellow color colloid consisting of silver nanoparticles (Ag NPs) has been synthesized by reducing aqueous AgNO3 solution by photo-induced citrate reduction technique under UV light. As prepared colloid exhibits single and intense plasmonic absorption peak in the violet region of the visible spectra with the peak centered at 405 nm. The NPs are fine and spherical with diameter ranging from 5 to 10 nm. These colloidal NPs have been used for the quantitative detection of uric acid by UV-VIS spectroscopy. A linear red shifting of the characteristics Plasmonic absorption peak of Ag NPs is observed with uric acid concentration. Uric acid can be detected by UV-VIS spectroscopy down to 5 nM limit using the prepared colloid.

  5. Bacterial Oxidation and Reduction of Iron in the Processes of Creation and Treatment of Acid Mining Waters

    Directory of Open Access Journals (Sweden)

    Daniel Kupka

    2004-12-01

    Full Text Available Acid mine drainages (AMDs arise at the weathering of sulphidic minerals. The occurrence of acidic streams is commonly associated with the human mining activities. Due to the disruption and excavation of sulphide deposits, the oxidation processes have initiated. Acidic products of sulphide oxidation accelerate the degradation of accompanying minerals. AMDs typically contain high concentrations of sulfuric acid and soluble metals and cause serious ecological problems due to the water pollution and the devastation of adjacent country. Microbial life in these extremely acidic environments may be considerably diverse. AMDs are abundant in bacteria capable to oxidize and/or to reduce iron. The rate of bacterial oxidation of ferrous iron released from pyrite surfaces is up to one million times faster than the chemical oxidation rate at low pH. Bacterial regeneration of ferric iron maintains the continuity of pyrite oxidation and the production of AMDs. Another group of microorganisms living in these environments are acidophilic ferric iron reducing bacteria. This group of microorganisms has been discovered only relatively recently. Acidophilic heterotrophic bacteria reduce ferric iron in either soluble or solid forms to ferrous iron. The reductive dissolution of ferric iron minerals brings about a mobilization of iron as well as associated heavy metals. The Bacterial oxidation and reduction of iron play an important role in the transformation of either crystalline or amorphous iron-containing minerals, including sulphides, oxides, hydroxysulfates, carbonates and silicates. This work discusses the role of acidophilic bacteria in the natural iron cycling and the genesis of acidic effluents. The possibilities of application of iron bacteria in the remediation of AMDs are also considered.

  6. Reductive dehalogenation of haloacetic acids by hemoglobin-loaded carbon nanotube electrode.

    Science.gov (United States)

    Li, Yu-Ping; Cao, Hong-Bin; Zhang, Yi

    2007-01-01

    Hemoglobin (Hb) was immobilized on carbon nanotube (CNT) electrode to catalyze the dehalogenation of haloacetic acids (HAAs). FTIR and UV measurements were performed to investigate the activity-keep of Hb after immobilization on CNT. The electrocatalytic behaviors of the Hb-loaded electrode for the dehalogenation of HAAs were studied by cyclic voltammmetry and constant-potential electrolysis technique. An Hb-loaded packed-bed flow reactor was also constructed for bioelectrocatalytic dehalogenation of HAAs. The results showed that Hb retained its nature, the essential features of its native secondary structure, and its biocatalytic activity after immobilization on CNT. Chloroacetic acids and bromoacetic acids could be dehalogenated completely with Hb catalysis through a stepwise dehalogenation process at -0.400V (vs. saturated calomel electrode (SCE)) and -0.200V (vs. SCE), respectively. The removal of 10.5mM trichloroacetic acid and dichloroacetic acid is ca. 97% and 63%, respectively, with electrolysis for 300min at -0.400V (vs. SCE) using the Hb-loaded packed-bed flow reactor, and almost 100% of tribromoacetic acid and dibromoacetic acid was removed with electrolysis for 40min at -0.200V (vs. SCE). The average current efficiency of Hb-catalytic dehalogenation almost reaches 100%.

  7. Reactions of clofibric acid with oxidative and reductive radicals—Products, mechanisms, efficiency and toxic effects

    International Nuclear Information System (INIS)

    Csay, Tamás; Rácz, Gergely; Salik, Ádám; Takács, Erzsébet; Wojnárovits, László

    2014-01-01

    The degradation of clofibric acid induced by hydroxyl radical, hydrated electron and O 2 −∙ /HO 2 ∙ reactive species was studied in aqueous solutions. Clofibric acid was decomposed more effectively by hydroxyl radical than by hydrated electron or O 2 −∙ /HO 2 ∙ . Various hydroxylated, dechlorinated and fragmentation products have been identified and quantified. A new LC–MS method was developed based on 18 O isotope labeling to follow the formation of hydroxylated derivatives of clofibric acid. Possible degradation pathways have been proposed. The overall degradation was monitored by determination of sum parameters like COD, TOC and AOX. It was found that the organic chlorine degrades very effectively prior to complete mineralization. After the treatment no toxic effect was found according to Vibrio fischeri tests. However, at early stages some of the reaction products were more harmful than clofibric acid. - Highlights: • Clofibric acid is effectively degraded by OH radical. • Main primary and secondary products are hydroxylated and dihydroxylated phenyl type derivatives of clofibric acid. • In air saturated aqueous solutions O 2 plays an important role in decomposition of the aromatic structure. • A new LC–MS method with 18 O-labeling was developed. • Early stage reaction products are more toxic to bacteria Vibrio fischeri than clofibric acid

  8. Reactions of clofibric acid with oxidative and reductive radicals-Products, mechanisms, efficiency and toxic effects

    Science.gov (United States)

    Csay, Tamás; Rácz, Gergely; Salik, Ádám; Takács, Erzsébet; Wojnárovits, László

    2014-09-01

    The degradation of clofibric acid induced by hydroxyl radical, hydrated electron and O2-•/HO2• reactive species was studied in aqueous solutions. Clofibric acid was decomposed more effectively by hydroxyl radical than by hydrated electron or O2-•/HO2•. Various hydroxylated, dechlorinated and fragmentation products have been identified and quantified. A new LC-MS method was developed based on 18O isotope labeling to follow the formation of hydroxylated derivatives of clofibric acid. Possible degradation pathways have been proposed. The overall degradation was monitored by determination of sum parameters like COD, TOC and AOX. It was found that the organic chlorine degrades very effectively prior to complete mineralization. After the treatment no toxic effect was found according to Vibrio fischeri tests. However, at early stages some of the reaction products were more harmful than clofibric acid.

  9. Catalytic role of Cu(II) in the reduction of Cr(VI) by citric acid under an irradiation of simulated solar light.

    Science.gov (United States)

    Li, Ying; Chen, Cheng; Zhang, Jing; Lan, Yeqing

    2015-05-01

    The catalytic role of Cu(II) in the reduction of Cr(VI) by citric acid with simulated solar light was investigated. The results demonstrated that Cu(II) could significantly accelerate Cr(VI) reduction and the reaction obeyed to pseudo zero-order kinetics with respect to Cr(VI). The removal of Cr(VI) was related to the initial concentrations of Cu(II), citric acid, and the types of organic acids. The optimal removal of Cr(VI) was achieved at pH 4, and the rates of Cu(II) photocatalytic reduction of Cr(VI) by organic acids were in the order: tartaric acid (two α-OH groups, two -COOH groups)>citric acid (one α-OH group, three -COOH groups)>malic acid (one α-OH group, two -COOH groups)>lactic acid (one α-OH group, one -COOH group)≫succinic acid (two -COOH groups), suggesting that the number of α-OH was the key factor for the reaction, followed by the number of -COOH. The formation of Cu(II)-citric acid complex could generate Cu(I) and radicals through a pathway of metal-ligand-electron transfer, promoting the reduction of Cr(VI). This study is helpful to fully understanding the conversion of Cr(VI) in the existence of both organic acids and Cu(II) with solar light in aquatic environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Reduction of Human Norovirus GI, GII, and Surrogates by Peracetic Acid and Monochloramine in Municipal Secondary Wastewater Effluent.

    Science.gov (United States)

    Dunkin, Nathan; Weng, ShihChi; Coulter, Caroline G; Jacangelo, Joseph G; Schwab, Kellogg J

    2017-10-17

    The objective of this study was to characterize human norovirus (hNoV) GI and GII reductions during disinfection by peracetic acid (PAA) and monochloramine in secondary wastewater (WW) and phosphate buffer (PB) as assessed by reverse transcription-qPCR (RT-qPCR). Infectivity and RT-qPCR reductions are also presented for surrogate viruses murine norovirus (MNV) and bacteriophage MS2 under identical experimental conditions to aid in interpretation of hNoV molecular data. In WW, RT-qPCR reductions were less than 0.5 log 10 for all viruses at concentration-time (CT) values up to 450 mg-min/L except for hNoV GI, where 1 log 10 reduction was observed at CT values of less than 50 mg-min/L for monochloramine and 200 mg-min/L for PAA. In PB, hNoV GI and MNV exhibited comparable resistance to PAA and monochloramine with CT values for 2 log 10 RT-qPCR reduction between 300 and 360 mg-min/L. Less than 1 log 10 reduction was observed for MS2 and hNoV GII in PB at CT values for both disinfectants up to 450 mg-min/L. Our results indicate that hNoVs exhibit genogroup dependent resistance and that disinfection practices targeting hNoV GII will result in equivalent or greater reductions for hNoV GI. These data provide valuable comparisons between hNoV and surrogate molecular signals that can begin the process of informing regulators and engineers on WW treatment plant design and operational practices necessary to inactivate hNoVs.

  11. Manganese Electrocatalysts with Bulky Bipyridine Ligands: Utilizing Lewis Acids To Promote Carbon Dioxide Reduction at Low Overpotentials.

    Science.gov (United States)

    Sampson, Matthew D; Kubiak, Clifford P

    2016-02-03

    Earth-abundant manganese bipyridine (bpy) complexes are well-established molecular electrocatalysts for proton-coupled carbon dioxide (CO2) reduction to carbon monoxide (CO). Recently, a bulky bipyridine ligand, 6,6'-dimesityl-2,2'-bipyridine (mesbpy), was utilized to significantly lower the potential necessary to access the doubly reduced states of these manganese catalysts by eliminating their ability to dimerize after one-electron reduction. Although this Mn mesbpy catalyst binds CO2 at very low potentials, reduction of a resulting Mn(I)-COOH complex at significantly more negative potentials is required to achieve fast catalytic rates. Without reduction of Mn(I)-COOH, catalysis occurs slowly via a alternate catalytic pathway-protonation of Mn(I)-COOH to form a cationic tetracarbonyl complex. We report the use of Lewis acids, specifically Mg(2+) cations, to significantly increase the rate of catalysis (by over 10-fold) at these low overpotentials (i.e., the same potential as CO2 binding). Reduction of CO2 occurs at one of the lowest overpotentials ever reported for molecular electrocatalysts (η = 0.3-0.45 V). With Mg(2+), catalysis proceeds via a reductive disproportionation reaction of 2CO2 + 2e(-) → CO and CO3(2-). Insights into the catalytic mechanism were gained by using variable concentration cyclic voltammetry, infrared spectroelectrochemistry, and bulk electrolysis studies. The catalytic Tafel behavior (log turnover frequency vs overpotential relationship) of [Mn(mesbpy)(CO)3(MeCN)](OTf) with added Mg(2+) is compared with those of other commonly studied CO2 reduction catalysts.

  12. Acidic bile salts induces mucosal barrier dysfunction through let-7a reduction during gastric carcinogenesis after Helicobacter pylori eradication

    Science.gov (United States)

    Takahashi, Yasushi; Uno, Kaname; Iijima, Katsunori; Abe, Yasuhiko; Koike, Tomoyuki; Asano, Naoki; Asanuma, Kiyotaka; Shimosegawa, Tooru

    2018-01-01

    Gastric cancer (GC) after eradication for Helicobacter pylori (H.pylori) increases, but its carcinogenesis is not elucidated. It is mainly found in acid non-secretion areas (ANA), as mucosal regeneration in acid secretory areas (AA) after eradication changes the acidity and bile toxicity of gastric juice. We aimed to clarify the role of barrier dysfunction of ANA by the stimulation of pH3 bile acid cocktail (ABC) during carcinogenesis. We collected 18 patients after curative endoscopic resection for GC, identified later than 24 months after eradication, and took biopsies by Congo-red chromoendoscopy to distinguish AA and ANA (UMIN00018967). The mucosal barrier function was investigated using a mini-Ussing chamber system and molecular biological methods. The reduction in mucosal impedance in ANA after stimulation was significantly larger than that in AA, 79.6% vs. 87.9%, respectively. The decrease of zonula occludens-1 (ZO-1) and let-7a and the increase of snail in ANA were significant compared to those in AA. In an in vitro study, the restoration of ZO-1 and let-7a as well as the induction of snail were observed after stimulation. High mobility group A2 (HMGA2)-snail activation, MTT proliferation, and cellular infiltration capacity were significantly increased in AGS transfected with let-7a inhibitor, and vice versa. Accordingly, using a mini-Ussing chamber system for human biopsy specimens followed by an in vitro study, we demonstrated for the first time that the exposure of acidic bile salts to ANA might cause serious barrier dysfunction through the let-7a reduction, promoting epithelial-mesenchymal transition during inflammation-associated carcinogenesis even after eradication. PMID:29719591

  13. Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Syeda Sara [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Sirajuddin, E-mail: drsiraj03@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Solangi, Amber Rehana [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Agheem, Mohammad Hassan [Center for Pure and Applied Geology, University of Sindh, Jamshoro 76080 (Pakistan); Junejo, Yasmeen; Kalwar, Nazar Hussain; Tagar, Zulfiqar Ali [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2011-06-15

    Highlights: {yields} Gold nanoparticles (AuNps) have been fabricated by a simple chemical method. {yields} AuNps were capped successfully in one step by mefenamic acid (MA). {yields} MA capped AuNps catalytically reduced the mixture of 3 dyes in just 15 s. {yields} AuNps were recovered by ionic liquid and reused for dye(s) reduction effectively. - Abstract: We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15 s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well.

  14. Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles

    International Nuclear Information System (INIS)

    Hassan, Syeda Sara; Sirajuddin; Solangi, Amber Rehana; Agheem, Mohammad Hassan; Junejo, Yasmeen; Kalwar, Nazar Hussain; Tagar, Zulfiqar Ali

    2011-01-01

    Highlights: → Gold nanoparticles (AuNps) have been fabricated by a simple chemical method. → AuNps were capped successfully in one step by mefenamic acid (MA). → MA capped AuNps catalytically reduced the mixture of 3 dyes in just 15 s. → AuNps were recovered by ionic liquid and reused for dye(s) reduction effectively. - Abstract: We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15 s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well.

  15. Heavy Metals and Radioactivity Reduction from Acid Mine Drainage Lime Neutralized Sludge

    Science.gov (United States)

    Mashifana, T.; Sithole, N.

    2018-03-01

    The worldwide known treatment processes of acid mine drainage result into the formation of hydrous ferric oxides that is amorphous, poorly crystalline and into the generation of hazardous voluminous sludge posing threat to the environment. Applicable treatment technologies to treat hazardous solid material and produce useful products are limited and in most cases nonexistence. A chemical treatment process utilizing different reagents was developed to treat hazardous acid mine drainage (AMD) sludge with the objectives to conduct radioactivity assessment of the sludge generated from lime treatment process and determine the reagent that provides the best results. Leaching with 0.5 M citric acid, 0.4 M oxalic acid, 0.5 M sodium carbonate and 0.5 M sodium bicarbonate was investigated. The leaching time applied was 24 hours at 25 °C. The characterization of the raw AMD revealed that the AMD sludge from lime treatment process is radioactive. The sludge was laden with radioactive elements namely, 238U, 214Pb, 226Ra, 232Th, 40K and 214Bi. 0.5 M citric acid provided the best results and the hazardous contaminants were significantly reduced. The constituents in the sludge after treatment revealed that there is a great potential for the sludge to be used for other applications such as building and construction.

  16. Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains.

    Science.gov (United States)

    Gupta, Raj Kishor; Gangoliya, Shivraj Singh; Singh, Nand Kumar

    2015-02-01

    More than half of the world populations are affected by micronutrient malnutrition and one third of world's population suffers from anemia and zinc deficiency, particularly in developing countries. Iron and zinc deficiencies are the major health problems worldwide. Phytic acid is the major storage form of phosphorous in cereals, legumes, oil seeds and nuts. Phytic acid is known as a food inhibitor which chelates micronutrient and prevents it to be bioavailabe for monogastric animals, including humans, because they lack enzyme phytase in their digestive tract. Several methods have been developed to reduce the phytic acid content in food and improve the nutritional value of cereal which becomes poor due to such antinutrient. These include genetic improvement as well as several pre-treatment methods such as fermentation, soaking, germination and enzymatic treatment of grains with phytase enzyme. Biofortification of staple crops using modern biotechnological techniques can potentially help in alleviating malnutrition in developing countries.

  17. Proton-coupled electron transfer promotes the reduction of ferrylmyoglobin by uric acid under physiological conditions

    DEFF Research Database (Denmark)

    de Zawadzki, Andressa; Cardoso, Daniel R.; Skibsted, Leif Horsfelt

    2017-01-01

    The hypervalent muscle pigment ferrylmyoglobin, MbFe(IV)]O, is not reduced by urate monoanions at physiological conditions despite a strong driving force of around 30 kJ mol1 while for low pH, uric acid was found to reduce protonated ferrylmyoglobin, MbFe(IV)]O,H+, efficiently in a bimolecular...... reaction with k1 ¼ 1.1 0.1 103 L mol1 s1, DH‡ ¼ 66.1 0.1 kJ mol1 and DS‡ ¼ 35.2 0.2 J mol1 K1. For intermediate pH, like for anaerobic muscles and for meat, proton-oupled electron transfer occurs in a transition state, {MbFe(IV)]O/H+/urate}‡, which is concluded to be formed from uric acid and Mb...... in uric acid concentration may serve as an inherent protection against radical formation by ferrylmyoglobin...

  18. Amino acid alphabet reduction preserves fold information contained in contact interactions in proteins.

    Science.gov (United States)

    Solis, Armando D

    2015-12-01

    To reduce complexity, understand generalized rules of protein folding, and facilitate de novo protein design, the 20-letter amino acid alphabet is commonly reduced to a smaller alphabet by clustering amino acids based on some measure of similarity. In this work, we seek the optimal alphabet that preserves as much of the structural information found in long-range (contact) interactions among amino acids in natively-folded proteins. We employ the Information Maximization Device, based on information theory, to partition the amino acids into well-defined clusters. Numbering from 2 to 19 groups, these optimal clusters of amino acids, while generated automatically, embody well-known properties of amino acids such as hydrophobicity/polarity, charge, size, and aromaticity, and are demonstrated to maintain the discriminative power of long-range interactions with minimal loss of mutual information. Our measurements suggest that reduced alphabets (of less than 10) are able to capture virtually all of the information residing in native contacts and may be sufficient for fold recognition, as demonstrated by extensive threading tests. In an expansive survey of the literature, we observe that alphabets derived from various approaches-including those derived from physicochemical intuition, local structure considerations, and sequence alignments of remote homologs-fare consistently well in preserving contact interaction information, highlighting a convergence in the various factors thought to be relevant to the folding code. Moreover, we find that alphabets commonly used in experimental protein design are nearly optimal and are largely coherent with observations that have arisen in this work. © 2015 Wiley Periodicals, Inc.

  19. Reduction of Pu(V) and Np(V) by leonardite humic acids and their quinonoid-enriched derivatives

    International Nuclear Information System (INIS)

    Shcherbina, N.S.; Kalmykov, St.N.; Perminova, I.V.; Kovalenko, A.N.

    2005-01-01

    Full text of publication follows: Humic substances (HS) are natural poly-electrolytes ubiquitous in aquatic environment responsible for complexation of metal ions. The presence of phenolic and quinonoid moieties in the structure of HS provide for their ability to take part in redox interactions. Capability of HS to reduce plutonium from higher oxidation states (Pu(V) and Pu(VI)) to tetravalent state was reported in several studies. However, the disparate results were reported for Np(V). The contradicting results on the redox behavior of HS could originate from the structural differences of the humic materials tested, in particular, from varying content of the redox-active quinonoid moieties. To test this hypothesis, the goal of this research was to evaluate reducing performance of leonardite humic acids and of their quinonoid-enriched derivatives with respect to Pu(V) and Np(V). The quinonoid-enriched humic derivatives were obtained using the reaction of formaldehyde co-poly-condensation between parent humic material - leonardite humic acid - and model dihydroxybenzenes - hydroquinone, catechol and 1,4-benzoquinone. The humic material: quinonoid monomer ration of 1 g per 250 mg was used. The reduction of Np(V) was studied at micro- and macro-concentration level: 10 -7 M and 10 -4 M, respectively. In case of Pu(V) the concentration was about 10 -10 M. The HS concentrations varied from 1 to 100 ppm, while ionic strength was zero. All experiments were conducted in anaerobic conditions and in the darkness. The kinetics of Pu(V) reduction was studied using solvent extraction (TTA in toluene); to monitor Np(V) reduction two independent techniques were used: solvent extraction and VIS-NIR spectrophotometry. The latter allows measuring absorbance of NpO 2 + and Np-humate complexes at 981.3 and 987.4 nm, respectively. Fast reduction of Pu(V) by the parent humic material was observed and the reduction rate increased with a decrease in pH. In case of Np(V), there was no

  20. REDUCTIVE DEHALOGENATION OF HEXACHLOROETHANE, CARBON TETRACHLORIDE, AND BROMOFORM BY ANTHRAHYDROQUINONE DISULFONATE AND HUMIC ACID

    Science.gov (United States)

    The reductive dehalogenation of hexachloroethane (CzCLj), carbon tetrachloride (CC14), and bromoform (CHBr3) was examined at 50 “C in aqueous solutions containing ei- ther (1) 500 pM of 2,6-anthrahydroquinone disulfonate (AHQDS), (2) 250 pM Fe2+, or (3) 250 pM HS-. The pH ranged ...

  1. Influence of chemical compositions and molecular weights of humic acids on Cr(VI) photo-reduction

    International Nuclear Information System (INIS)

    Chen, S.Y.; Huang, S.W.; Chiang, P.N.; Liu, J.C.; Kuan, W.H.; Huang, J.H.; Hung, J.T.; Tzou, Y.M.; Chen, C.C.; Wang, M.K.

    2011-01-01

    Highlights: ► Low molecular weights (M w ) of HA bear more polar and aromatic C in its structure. ► The polar sites of HA dominate the photo-reduction of Cr(VI). ► Low M w of HA exhibits greater photochemical efficiency for Cr(VI) reduction. ► Cr(VI) adsorption on HA is indiscernible, particularly on the small M w of HA. ► Upon Cr(VI) reduction by HA, most of Cr(III) are released into the solution. - Abstract: Humic acids (HA) strongly affect the fate of trace metals in soils and aquatic environments. One of the remarkable properties of HA is its ability to reduce Cr(VI), an extremely toxic anion. However, it is unclear which HA components are involved in Cr(VI) reduction and possess the photo-induced properties. In this study, an ultrafiltration technique was used to fractionate HAs into four fractions of different nominal molecular weights (M w ): >100, 50–100, 10–50 and w HA was enriched with polar and aromatic domains. These polar, including polar C in aliphatic region, and aromatic groups were the major sites for Cr(VI) reduction because they disappeared rapidly upon interaction with Cr(VI). As a result, low M w of HA exhibited greater efficiency of Cr(VI) reduction. Light induced the rapid transfer of electrons between chromate-phenol/carboxyl ester, or the formation of peroxide radicals or H 2 O 2 through the ready decay of peroxy radicals associated with polar substituents, explained the rapid scavenging of Cr(VI) on polar and aromatic groups of HAs under illumination.

  2. Catalyst evaluation for oxygen reduction reaction in concentrated phosphoric acid at elevated temperatures

    DEFF Research Database (Denmark)

    Hu, Yang; Jiang, Yiliang; Jensen, Jens Oluf

    2018-01-01

    Phosphoric acid is the common electrolyte for high-temperature polymer electrolyte fuel cells (HT-PEMFCs) that have advantages such as enhanced CO tolerance and simplified heat and water management. The currently used rotating disk electrode technique is limited to tests in dilute solutions at lo...

  3. 3-Methylindole-Based Tripodal Tetraphosphine Ruthenium Complexes in N2 Coordination and Reduction and Formic Acid Dehydrogenation

    Directory of Open Access Journals (Sweden)

    Fenna F. van de Watering

    2017-10-01

    Full Text Available The ruthenium(II complexes RuCl2L1H, RuCl2L1CF3, RuCl2L1OMe and RuCl2L2H were synthesized from [Ru(η6-benzeneCl(μ-Cl]2 and the corresponding tripodal tris-3-methylindolephosphine-based ligands L1H, L1CF3, L1OMe, and L2H. Stoichiometric reduction of these complexes with KC8 yielded the corresponding ruthenium(0 dinitrogen complexes. The latter complexes were studied in the N2 reduction with chlorosilanes and KC8, yielding stoichiometric amounts of the silylamines. The synthesized ruthenium(II complexes are also active catalysts for the formic acid dehydrogenation reaction.

  4. Gallic acid reduces cell growth by induction of apoptosis and reduction of IL-8 in HepG2 cells.

    Science.gov (United States)

    Lima, Kelly Goulart; Krause, Gabriele Catyana; Schuster, Aline Daniele; Catarina, Anderson Velasque; Basso, Bruno Souza; De Mesquita, Fernanda Cristina; Pedrazza, Leonardo; Marczak, Elisa Simon; Martha, Bianca Andrade; Nunes, Fernanda Bordignon; Chiela, Eduardo Cremonese Filippi; Jaeger, Natália; Thomé, Marcos Paulo; Haute, Gabriela Viegas; Dias, Henrique Bregolin; Donadio, Márcio Vinícius Fagundes; De Oliveira, Jarbas Rodrigues

    2016-12-01

    Hepatocellular carcinoma is the most prevalent primary liver tumor and is among the top ten cancer that affect the world population. Its development is related, in most cases, to the existence of chronic liver injury, such as in cirrhosis. The knowledge about the correlation between chronic inflammation and cancer has driven new researches with anti-inflammatory agents that have potential for the development of antitumor drugs. Gallic acid is a phenolic acid found in many natural products and have shown anti-inflammatory, anti-tumor, anti-mutagenic and antioxidant actions. The purpose of this study was to investigate the effect of gallic acid on acute and chronic cell proliferation and inflammatory parameters of hepatocellular carcinoma cells (HepG2), as well as to investigate the mechanisms involved. Results showed that the gallic acid decreased the proliferation of HepG2 cells in a dose-dependent manner (Trypan blue exclusion assay), without causing necrosis (LDH assay). We observed a significant increase in the percentage of small and regular nuclei (Nuclear Morphometric Analysis assay), a significant induction of apoptosis by Annexin V-FITC and PI assay and no interference with the cell cycle using the FITC BrdU Flow Kit. We observed a significant reduction in the levels of IL-8 and increased levels of IL-10 and IL-12 (Cytometric Bead Array Human Inflammation Assay). Furthermore, gallic acid caused no cancer cells regrowth at a long term (Cumulative Population Doubling assay). According to these results, gallic acid showed a strong potential as an anti-tumor agent in hepatocellular carcinoma cells. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. Indium-Catalyzed Reductive Dithioacetalization of Carboxylic Acids with Dithiols: Scope, Limitations, and Application to Oxidative Desulfurization.

    Science.gov (United States)

    Nishino, Kota; Minato, Kohei; Miyazaki, Takahiro; Ogiwara, Yohei; Sakai, Norio

    2017-04-07

    In this study an InI 3 -TMDS (1,1,3,3-tetramethyldisiloxane) reducing system effectively catalyzed the reductive dithioacetalization of a variety of aromatic and aliphatic carboxylic acids with 1,2-ethanedithiol or 1,3-propanedithiol leading to the one-pot preparation of either 1,3-dithiolane derivatives or a 1,3-dithiane derivative. Also, the intact indium catalyst continuously catalyzed the subsequent oxidative desulfurization of an in situ formed 1,3-dithiolane derivative, which led to the preparation of the corresponding aldehydes.

  6. Redox cycles of vitamin E: Hydrolysis and ascorbic acid dependent reduction of 8a-(alkyldioxy)tocopherones

    International Nuclear Information System (INIS)

    Liebler, D.C.; Kaysen, K.L.; Kennedy, T.A.

    1989-01-01

    Oxidation of the biological antioxidant α-tocopherol (vitamin E; TH) by peroxyl radicals yields 8a-(alkyldioxy)tocopherones, which either may hydrolyze to α-tocopheryl quinone (TQ) or may be reduced by ascorbic acid to regenerate TH. To define the chemistry of this putative two-electron TH redox cycle, we studied the hydrolysis and reduction of 8a-[(2,4-dimethyl-1-nitrilopent-2-yl)dioxyl]tocopherone (1) in acetonitrile/buffer mixtures and in phospholipid liposomes. TQ formation in acetonitrile/buffer mixtures, which was monitored spectrophotometrically, declined with increasing pH and could not be detected above pH 4. The rate of TQ formation from 1 first increased with time and then decreased in a first-order terminal phase. Rearrangement of 8a-hydroxy-α-tocopherone (2) to TQ displayed first-order kinetics identical with the terminal phase for TQ formation from 1. Both rate constants increased with decreasing pH. Hydrolysis of 1 in acetonitrile/H 2 18 O yielded [ 18 O]TQ. These observations suggest that 1 loses the 8a-(alkyldioxy) moiety to produce the tocopherone cation (T + ), which hydrolyzes to 2, the TQ-forming intermediate. Incubation of either 1 or 2 with ascorbic acid in acetonitrile/buffer yielded TH. Reduction of both 1 and 2 decreased with increasing pH. In phosphatidylcholine liposomes at pH 7, approximately 10% of the T + generated from 1 was reduced to TH by 5 mM ascorbic acid. The results collectively demonstrate that T + is the ascorbic acid reducible intermediate in a two-electron TH redox cycle, a process that probably would require biocatalysis to proceed in biological membranes

  7. Reductive Dehalogenation of Trichloroacetic Acid by Trichlorobacter thiogenes gen. nov., sp. nov.

    Science.gov (United States)

    De Wever, Helene; Cole, James R.; Fettig, Michael R.; Hogan, Deborah A.; Tiedje, James M.

    2000-01-01

    A bacterium able to grow via reductive dechlorination of trichloroacetate was isolated from anaerobic soil enrichments. The isolate, designated strain K1, is a member of the δ proteobacteria and is related to other known sulfur and ferric iron reducers. In anaerobic mineral media supplemented with acetate and trichloroacetate, its doubling time was 6 h. Alternative electron donor and acceptors were acetoin and sulfur or fumarate, respectively. Trichloroacetate dehalogenation activity was constitutively present, and the dechlorination product was dichloroacetate and chloride. Trichloroacetate conversion seemed to be coupled to a novel sulfur-sulfide redox cycle, which shuttled electrons from acetate oxidation to trichloroacetate reduction. In view of its unique physiological characteristics, the name Trichlorobacter thiogenes is suggested for strain K1. PMID:10831402

  8. Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

    International Nuclear Information System (INIS)

    Becker, Jan C.; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

    2006-01-01

    Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection

  9. Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Jan C [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Grosser, Nina [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Waltke, Christian [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Schulz, Stephanie [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Erdmann, Kati [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Domschke, Wolfram [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Schroeder, Henning [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Pohle, Thorsten [Department of Medicine B, University of Muenster, 48149 Muenster (Germany)

    2006-07-07

    Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

  10. Reduction of Burn Progression with Topical Delivery of (Antitumor Necrosis Factor-alpha )-Hyaluronic Acid Conjugates

    Science.gov (United States)

    2012-01-01

    antibody conjugation to HA The conjugation chemistry followed a method previously developed in our laboratory. Briefly, HA (12 mg) was modi - fied...Webster MW, McGill JB, Schwartz SL. Promotion and acceleration of diabetic ulcer healing by arginine-glycine-aspartic acid (RGD) peptide matrix. RGD...Study Group. Diabetes Care 1995; 18: 39–46. 32. Ho-Asjoe M, Chronnell CM, Frame JD, Leigh IM, Carver N. Immunohistochemical analysis of burn depth. J

  11. Iodide-photocatalyzed reduction of carbon dioxide to formic acid with thiols and hydrogen sulfide

    OpenAIRE

    Berton, Mateo Otao; Mello, Rossella C. C.; González Núñez, María Elena

    2016-01-01

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO2 capture coupled with H2S removal may have been relevant as a prebiotic carbon dioxide fixation.

  12. Reduction of dietary saturated fatty acids correlates with increased plasma lecithin cholesterol acyltransferase activity in humans.

    Science.gov (United States)

    Bérard, A M; Dabadie, H; Palos-Pinto, A; Dumon, M-F; Darmon, M

    2004-06-01

    Increased HDL-cholesterol (HDL-C) concentrations have been associated with lower coronary heart disease risk. On the other hand, dietary fats are known to influence the fatty acid profile of plasma lipids, including phospholipids that are substrates of lecithin cholesterol acyltransferase (LCAT), an important enzyme in HDL metabolism. The purpose of this study was to examine the association between the saturated fatty acid (SFA) intake and LCAT activity. An interventional study was performed in a monk community of 25 men. A French monk community, South West of France. The basal diet of the study cohort contained SFA in a proportion of 13.5% of their total energy intake (TEI). They were submitted to two experimental isocaloric diets containing either 8.4% of the TEI in SFA (diet A) or 11% (diet B), each lasting 5 weeks. The elevation of SFA in diet B was mainly obtained by decreasing carbohydrates. The only significant difference among total fats between diets A and B was the myristic acid content (0.6 and 1.2% of TEI, respectively). The elevation in SFA in diet B resulted in a significant increase of HDL-C (P<0.04), while plasma apo A-I concentration and LCAT activity both decreased (P<0.02). Altogether, these results are consistent with a negative effect of SFA on reverse cholesterol transport.

  13. Study on radiation-induced oxide-reduction of actinoid ions in acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Ishigure, Kenkichi; Katsumura, Yosuke; Hiroishi, Daisuke [Tokyo Univ. (Japan). Faculty of Engineering; and others

    1996-01-01

    Many studies have been made on the application of actinoid ion, especially UO{sub 2}{sup 2+} to change atomic valance but the mechanism of photoreduction has not yet been solved. In this study, the mechanism of photoreduction of UO{sub 2}{sup 2+} in acid solution was investigated. As functions of alcohol and acid concentrations, {phi}(U{sup IV}) was determined and photoreduction of UO{sub 2}{sup 2+} was investigated as well as NpO{sub 2}{sup 2+}. As an increase of alcohol content (EtOH, MtOH, iso-PrOH), {phi}(U{sup IV}) increased to reach a plateau ({approx}0.6). In addition, {phi}(U{sup IV}) increased linearly with an increase of acid content and the value became smaller in the order, H{sub 3}PO{sub 4}, H{sub 2}SO{sub 4}, HClO{sub 4} solution. Comparing with these results of UO{sub 2}{sup 2+}, photoreduction of NpO{sub 2}{sup 2+} was investigated. Only NpO{sub 2}{sup +} was produced as the final products, but not Np{sup IV} and NP{sup III}. Alcohol dependency of NpO{sub 2}{sup 2+} photoreduction was similar to that of UO{sub 2}{sup 2+} system but the plateau level of {phi} (NpO{sub 2}{sup 2+}) was lower ({approx}0.15) than the latter. (M.N.)

  14. The impact of serum uric acid reduction on renal function and blood pressure in chronic kidney disease patients with hyperuricemia.

    Science.gov (United States)

    Tsuji, Takayuki; Ohishi, Kazuhisa; Takeda, Asumi; Goto, Daiki; Sato, Taichi; Ohashi, Naro; Fujigaki, Yoshihide; Kato, Akihiko; Yasuda, Hideo

    2018-04-26

    Febuxostat is tolerable in chronic kidney disease (CKD) patients with hyperuricemia. However, the long-term effect of lowering uric acid with febuxostat on renal function and blood pressure has not been elucidated. This was a 2 years retrospective observational study. 86 CKD patients with hyperuricemia who continued with allopurinol (allopurinol group, n = 30), switched from allopurinol to febuxostat (switched group, n = 25), or were newly prescribed febuxostat (febuxostat group, n = 31) were included in this study. Serum uric acid, estimated glomerular filtration rate (eGFR), blood pressure, and urinary protein were analyzed. Moreover, the impact of serum uric acid reduction on renal function and blood pressure was assessed. Serum uric acid in the switched and febuxostat groups was significantly reduced at 6 months (switched group; 8.49 ± 1.32-7.19 ± 1.14 mg/dL, p uric acid was increased (6.86 ± 0.87-7.10 ± 0.85 mg/dL, p = 0.0213). eGFR was significantly increased (35.2 ± 12.8-37.3 ± 13.9 mL/min/1.73 m 2 , p = 0.0232), while mean arterial pressure (93.1 ± 10.8-88.2 ± 9.5 mmHg, p = 0.0039) was significantly decreased at 6 months in the febuxostat group, resulting in the retention of eGFR for 2 years. The impact of serum uric acid reduction might have beneficial effects on CKD progression and blood pressure. However, a large prospective study is needed to determine the long-term efficacy of febuxostat therapy in CKD patients with hyperuricemia.

  15. Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process.

    Science.gov (United States)

    Mingfei, Xing; Yaping, Wang; Jun, Li; Hua, Xu

    2016-03-15

    In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Notch stimulates growth by direct regulation of genes involved in the control of glycolysis and the tricarboxylic acid cycle

    Czech Academy of Sciences Publication Activity Database

    Slaninová, Věra; Krafčíková, M.; Perez-Gomez, R.; Steffal, P.; Trantírek, L.; Bray, S. J.; Krejčí, Alena

    2016-01-01

    Roč. 6, Feb 15 (2016), s. 150155 ISSN 2046-2441 R&D Projects: GA ČR(CZ) GAP305/11/0126; GA ČR(CZ) GA14-08583S Grant - others:EU program (FP7/2007-20013)(CZ) 316304; POSTDOC2(CZ) CZ.1.07/2.3.00/30.0049 Program:FP7 Institutional support: RVO:60077344 Keywords : metabolism * Notch targets * Warburg effect Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.481, year: 2016 http://rsob.royalsocietypublishing.org/content/royopenbio/6/2/150155.full.pdf

  17. Kinetics of oxygen reduction reaction at tin-adatoms-modified gold electrodes in acidic media

    International Nuclear Information System (INIS)

    Miah, Md. Rezwan; Ohsaka, Takeo

    2009-01-01

    In the present report, oxygen reduction reaction (ORR) at polycrystalline gold (Au (poly)) electrode in situ modified by the underpotential deposition (upd) of Sn-adatoms is addressed. The ORR was investigated at the Sn-adatoms-modified Au (poly) electrode by the hydrodynamic voltammetric technique with a view to evaluating the various related kinetic parameters. The results demonstrated that the underpotential deposited Sn-adatoms on the Au (poly) electrode substantially promoted the activity of the electrode towards an exclusive one-step four-electron ORR forming H 2 O as the final product.

  18. Kinetics of oxygen reduction reaction at tin-adatoms-modified gold electrodes in acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Miah, Md. Rezwan [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Mail Box G1-5, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)], E-mail: mrmche@yahoo.com; Ohsaka, Takeo [Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Mail Box G1-5, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)], E-mail: ohsaka@echem.titech.ac.jp

    2009-10-01

    In the present report, oxygen reduction reaction (ORR) at polycrystalline gold (Au (poly)) electrode in situ modified by the underpotential deposition (upd) of Sn-adatoms is addressed. The ORR was investigated at the Sn-adatoms-modified Au (poly) electrode by the hydrodynamic voltammetric technique with a view to evaluating the various related kinetic parameters. The results demonstrated that the underpotential deposited Sn-adatoms on the Au (poly) electrode substantially promoted the activity of the electrode towards an exclusive one-step four-electron ORR forming H{sub 2}O as the final product.

  19. Asymmetric Meerwein–Ponndorf–Verley reduction of long chain keto alkanoic acid methyl esters

    Directory of Open Access Journals (Sweden)

    AYE YUSUFOGLU

    2007-05-01

    Full Text Available 3-, 7- and 13-Monoketo tetradecanoic acid methyl esters carrying a ketogroup at the ends and at the middle of the chain with 14 carbon atoms were reduced by a Meerwein–Ponndorf–Verley reaction in the presence of R-(+-1,1'-binaphthalene-2,2'-diol, 1,2:5,6-D-di-O-isopropylidene-D-mannitol and L-(–-menthol. The highest enantiomeric purity of 65% ee was found for 13-hydroxy ester isomer. The enantiomeric excess was determined by 1H-NMR shift with Eu(tfc3 and by optical rotation.

  20. Iodide-Photocatalyzed Reduction of Carbon Dioxide to Formic Acid with Thiols and Hydrogen Sulfide.

    Science.gov (United States)

    Berton, Mateo; Mello, Rossella; González-Núñez, María Elena

    2016-12-20

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO 2 capture coupled with H 2 S removal may have been relevant as a prebiotic carbon dioxide fixation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Enzymatically and reductively degradable α-amino acid-based poly(ester amide)s: Synthesis, cell compatibility, and intracellular anticancer drug delivery

    NARCIS (Netherlands)

    Sun, H.; Cheng, Ru; Deng, Chao; Meng, Fenghua; Dias, Aylvin A.; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

    2015-01-01

    A novel and versatile family of enzymatically and reductively degradable α-amino acid-based poly(ester amide)s (SS-PEAs) were developed from solution polycondensation of disulfide-containing di-p-toluenesulfonic acid salts of bis-l-phenylalanine diesters (SS-Phe-2TsOH) with di-p-nitrophenyl adipate

  2. Reduction of acid rock drainage using steel slag in cover systems over sulfide rock waste piles.

    Science.gov (United States)

    de Almeida, Rodrigo Pereira; Leite, Adilson do Lago; Borghetti Soares, Anderson

    2015-04-01

    The extraction of gold, coal, nickel, uranium, copper and other earth-moving activities almost always leads to environmental damage. In metal and coal extraction, exposure of sulfide minerals to the atmosphere leads to generation of acid rock drainage (ARD) and in underground mining to acid mine drainage (AMD) due to contamination of infiltrating groundwater. This study proposes to develop a reactive cover system that inhibits infiltration of oxygen and also releases alkalinity to increase the pH of generated ARD and attenuate metal contaminants at the same time. The reactive cover system is constructed using steel slag, a waste product generated from steel industries. This study shows that this type of cover system has the potential to reduce some of the adverse effects of sulfide mine waste disposal on land. Geochemical and geotechnical characterization tests were carried out. Different proportions of sulfide mine waste and steel slag were studied in leachate extraction tests. The best proportion was 33% of steel slag in dry weight. Other tests were conducted as follows: soil consolidation, saturated permeability and soil water characteristic curve. The cover system was numerically modeled through unsaturated flux analysis using Vadose/w. The solution proposed is an oxygen transport barrier that allows rain water percolation to treat the ARD in the waste rock pile. The results showed that the waste pile slope is an important factor and the cover system must have 5 m thickness to achieve an acceptable effectiveness. © The Author(s) 2015.

  3. Cofactor and CO2 donor regulation involved in reductive routes for polymalic acid production by Aureobasidium pullulans CCTCC M2012223.

    Science.gov (United States)

    Zou, Xiang; Tu, Guangwei; Zan, Zhanquan

    2014-10-01

    Polymalic acid (PMA) is a water-soluble polyester with many attractive properties for biomedical application. Its monomer L-malic acid is widely used in the food industry and also a potential C4 platform chemical. Cofactor and CO2 donor involved in the reductive routes were investigated for PMA production by Aureobasidium pullulans. Biotin as the key cofactor of pyruvate carboxylase was favor for the PMA biosynthesis. Na2CO3 as CO2 donor can obviously improved PMA titer when compared with no CO2 supplier NaOH, and also exhibit more advantages than the other donor CaCO3 because of its water-soluble characteristic. A combinational process with addition of biotin 70 mg/L and Na2CO3 as the CO2 donor was scaled-up in 50 L fermentor, achieving the high product 34.3 g/L of PMA and productivity of 0.41 g/L h. This process provides an efficient and economical way for PMA and malic acid production, and is promising for industrial application.

  4. Influence of chemical compositions and molecular weights of humic acids on Cr(VI) photo-reduction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.Y.; Huang, S.W. [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung, 40227 Taiwan, ROC (China); Chiang, P.N. [The Experimental Forest, National Taiwan University, Nantou, 55743 Taiwan, ROC (China); Liu, J.C. [Agricultural Research Institute No. 189, Jhongjheng Rd., Wufong, Taichung County, 41301 Taiwan, ROC (China); Kuan, W.H. [Department of Safety, Health, and Environmental Engineering, Ming Chi University of Technology, Taishan, Taipei, 24301 Taiwan, ROC (China); Huang, J.H. [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung, 40227 Taiwan, ROC (China); Hung, J.T. [Department of Horticulture, National Taitung Junior College, Taitung, 95045 Taiwan, ROC (China); Tzou, Y.M., E-mail: ymtzou@dragon.nchu.edu.tw [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung, 40227 Taiwan, ROC (China); Chen, C.C. [Department of Life Science, National Taiwan Normal University, Taipei, 116 Taiwan, ROC (China); Wang, M.K. [Department of Agricultural Chemistry, National Taiwan University, Taipei, 10617 Taiwan, ROC (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Low molecular weights (M{sub w}) of HA bear more polar and aromatic C in its structure. Black-Right-Pointing-Pointer The polar sites of HA dominate the photo-reduction of Cr(VI). Black-Right-Pointing-Pointer Low M{sub w} of HA exhibits greater photochemical efficiency for Cr(VI) reduction. Black-Right-Pointing-Pointer Cr(VI) adsorption on HA is indiscernible, particularly on the small M{sub w} of HA. Black-Right-Pointing-Pointer Upon Cr(VI) reduction by HA, most of Cr(III) are released into the solution. - Abstract: Humic acids (HA) strongly affect the fate of trace metals in soils and aquatic environments. One of the remarkable properties of HA is its ability to reduce Cr(VI), an extremely toxic anion. However, it is unclear which HA components are involved in Cr(VI) reduction and possess the photo-induced properties. In this study, an ultrafiltration technique was used to fractionate HAs into four fractions of different nominal molecular weights (M{sub w}): >100, 50-100, 10-50 and <10 kDa. Each HA fraction was characterized by spectroscopic analyses followed by examining Cr(VI) removal on each fraction of HA at pH 1-5. Spectroscopic results indicated that low-M{sub w} HA was enriched with polar and aromatic domains. These polar, including polar C in aliphatic region, and aromatic groups were the major sites for Cr(VI) reduction because they disappeared rapidly upon interaction with Cr(VI). As a result, low M{sub w} of HA exhibited greater efficiency of Cr(VI) reduction. Light induced the rapid transfer of electrons between chromate-phenol/carboxyl ester, or the formation of peroxide radicals or H{sub 2}O{sub 2} through the ready decay of peroxy radicals associated with polar substituents, explained the rapid scavenging of Cr(VI) on polar and aromatic groups of HAs under illumination.

  5. Microbial Reduction of Fe(III) in Acidic Sediments: Isolation of Acidiphilium cryptum JF-5 Capable of Coupling the Reduction of Fe(III) to the Oxidation of Glucose

    OpenAIRE

    Küsel, Kirsten; Dorsch, Tanja; Acker, Georg; Stackebrandt, Erko

    1999-01-01

    To evaluate the microbial populations involved in the reduction of Fe(III) in an acidic, iron-rich sediment, the anaerobic flow of supplemental carbon and reductant was evaluated in sediment microcosms at the in situ temperature of 12°C. Supplemental glucose and cellobiose stimulated the formation of Fe(II); 42 and 21% of the reducing equivalents that were theoretically obtained from glucose and cellobiose, respectively, were recovered in Fe(II). Likewise, supplemental H2 was consumed by acid...

  6. Oxygen reduction reaction on carbon-supported CoSe2 nanoparticles in an acidic medium

    International Nuclear Information System (INIS)

    Feng Yongjun; He Ting; Alonso-Vante, Nicolas

    2009-01-01

    We investigated the effect of CoSe 2 /C nanoparticle loading rate on oxygen reduction reaction (ORR) activity and H 2 O 2 production using the rotating disk electrode and the rotating ring-disk electrode techniques. We prepared carbon-supported CoSe 2 nanoparticles with different nominal loading rates and evaluated these samples by means of powder X-ray diffraction. All the catalysts had an OCP value of 0.81 V vs. RHE. H 2 O 2 production during the ORR process decreased with an increase in catalytic layer thickness. This decrease was related to the CoSe 2 loading on the disk electrode. H 2 O 2 production also decreased with increasing catalytic site density, a phenomenon related to the CoSe 2 loading rate on the carbon substrate. The cathodic current density significantly increased with increasing catalytic layer thickness, but decreased with increasing catalytic site density. In the case of 20 wt% CoSe 2 /C nanoparticles at 22 μg cm -2 , we determined that the transfer process involves about 3.5 electrons.

  7. Investigations of Pd-Cu electrocatalyst for oxygen reduction reaction in acidic media with RDE method

    Energy Technology Data Exchange (ETDEWEB)

    Fouda-Onana, F.; Bah, S.; Savadogo, O. [Ecole Polytechnique de Montreal, Montreal, PQ (Canada). Laboratoire de nouveaux materiaux pour l' energie et l' electrochimie

    2008-07-01

    The kinetics of the oxygen reduction reaction (ORR) has been studied extensively with different platinum bi-metallic alloys such as Pt-Fe, Pt-Ni, Pt-Co. However, palladium-based bi-metallic alloys are being considered as a substitute for platinum in electrocatalysts. This paper reported on a study that investigated the ORR on bi-metallic Pd-Cu electrocatalyst. Different contents in Cu were analyzed and an optimal Cu composition leading to the highest ORR activity was found. A mechanism of the ORR kinetics for this catalyst was introduced based on the value of the Tafel slope. A smooth increase in surface area up to 50 per cent Cu was observed to a constant value of 23 cm{sup 2}. Such behaviour was due to the high dispersion of Pd as Cu increased and segregated. A volcano-shape was found between the kinetic current, activation energy and the Cu composition. The maximum exchange current density and the lowest activation energy were found for Pd50Cu50, which corresponded to the highest surface area. All Pd-Cu alloys presented a higher kinetic current than Pd alone. 3 refs., 1 tab., 3 figs.

  8. Test and data reduction algorithm for the evaluation of lead-acid battery packs

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, D.

    1986-01-15

    Experience from the DOE Electric Vehicle Demonstration Project indicated severe battery problems associated with driving electric cars in temperature extremes. The vehicle batteries suffered from a high module failure rate, reduced capacity, and low efficiency. To assess the nature and the extent of the battery problems encountered at various operating temperatures, a test program was established at the University of Alabama in Huntsville (UAH). A test facility was built that is based on Propel cycling equipment, the Hewlett Packard 3497A Data Acquisition System, and the HP85F and HP87 computers. The objective was to establish a cost effective facility that could generate the engineering data base needed for the development of thermal management systems, destratification systems, central watering systems and proper charge algorithms. It was hoped that the development and implementation of these systems by EV manufacturers and fleet operators of EVs would eliminate the most pressing problems that occurred in the DOE EV Demonstration Project. The data reduction algorithm is described.

  9. Laser enhanced reductions of uranium(VI) ion in aqueous phosphoric acid solutions

    International Nuclear Information System (INIS)

    Park, Y.Y.; Harada, M.; Tomiyasu, H.; Ikeda, Y.; Takashima, Y.

    1991-01-01

    Photochemical reactions of U(VI) ions with inorganic anions (I - , Br - , Cl - , NCS - ) and organic compounds (1-hexene, cyclohexene, pyridine) in phosphoric acid were studied for the purpose of finding an efficient method of adjusting the oxidation states of uranium ions in nuclear fuel reprocessing. The formation of U(IV) was observed in the photoreactions with I - , Br - and NCS - , but not with Cl - . The yield of U(VI) increased in the order, Br - - - . This order was the same as the quenching rate constants of the excited U(VI) ions with these anions, and the reverse of their standard redox potentials. The rates of the formation of U(IV) in the presence of Br - were measured spectrophotometrically. It was found that the rate equation was first order in both [U(VI)] and [Br - ]. The results were reasonably interpreted by a series of reaction processes involving U(V) and Br radical. With organic molecules, 1-hexene, cyclohexene, and pyridine, the formation of U(IV) were observed. The yield of U(IV) increased in the order pyridine < 1-hexene < cyclohexene. This order is the reverse of their vertical ionization potentials, suggesting an electron transfer mechanism between these organic molecules and excited U(VI). (author)

  10. Mode of action of alginic acid compound in the reduction of gastroesophageal reflux

    International Nuclear Information System (INIS)

    Malmud, L.S.; Charkes, N.D.; Littlefield, J.; Reilley, J.; Stern, H.; Rosenberg, R.; Fisher, R.S.

    1979-01-01

    This study was designed to evaluate quantitatively the mode of action of alginic acid compound (AAC) in the treatment of patients with symptomatic gastroesophageal reflux. Gastroesophageal scintigraphy using an orally administered Tc-99m sulfur colloid solution was used to demonstrate that AAC decreased significantly the gastroesophageal reflux index from (9.9 +- 1.3)% to (6.5 +- 0.8)% (p < 0.05). No alteration of lower esophageal sphincter pressure was observed. After AAC was suitably labeled with Sr-87m, a dual-nuclide scintigraphic technique was used to show that most (< 75%) of the AAC was located in the upper half of the stomach in both normal subjects and patients with gastroesophageal reflux. In those subjects in whom reflux did occur after treatment with AAC, the Sr-87m-AAC refluxed into the esophagus preferentially compared with the liquid containing Tc-99m sulfur colloid. These findings suggest that AAC diminishes gastroesophageal reflux by means of its foaming, floating, and viscous properties

  11. Study of oxidation-reduction reactions of plutonium and neptunium in sulphuric-phosphoric acid media

    International Nuclear Information System (INIS)

    Moiseev, I.V.; Kuperman, A.Ya.; Borodina, N.N.; Galkina, V.N.; Vinokurov, V.A.

    1976-01-01

    Potentiostatic, coulometric, potentiometric, and amperometric methods have been used for determining the rate constants of disproportionation (ksub(d)) of plutonium(5) and neptunium (5) and normal real redox potentials (Esub(0)sup(p)) of the following ion pairs in sulphur-phosphoric-acid media: PuOsub(2)sup(2)sup(+) (PuO 2 + , Pu 4+ /Pu 3+ , NpO 2 2+ /NpO 2 + , NpO 2 2+ /Np 4+ , NpO 2 + /Np 4+ , and Fe 3+ /Fe 2+ . The regularities have been shown of changing ksub(d) and Esub(o)sup(p) as a function of H 2 SO 4 and H 3 PO 4 concentration. It has been established that for plutonium and neptunium a linear correlation is observed between lg ksub(d) and Esub(o)sup(p) of the ion pairs NpO 2 2+ /NpO 2 + , NpO 2 2 /Np 4+ , NpO 2 + /Np 4+ and PuO 2 2+ /PuO 2 + in a wide range of their values. The correlation coefficient is close to unity in all cases (no less than 0.96). The results of investigations have made it possible to recommend optimum compositions of background electrolytes for performing continuous amperostatic coulometric titration of Pusup((6)) and Npsup((6)) up to four valent state by electrogenerated ions of iron (2)

  12. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

    2015-01-07

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

  13. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    International Nuclear Information System (INIS)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige; Chen, Xingguo

    2015-01-01

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe 3+ ion sensing by fluorescence quenching is developed. • The method for Fe 3+ sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe 3+ ) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe 3+ permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe 3+ in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%

  14. Plasma debrisoquin levels in the assessment of reduction of plasma homovanillic acid. The debrisoquin method.

    Science.gov (United States)

    Riddle, M A; Jatlow, P I; Anderson, G M; Cho, S C; Hardin, M T; Cohen, D J; Leckman, J F

    1989-06-01

    Plasma concentrations of unconjugated homovanillic acid (pHVA) reflect both central nervous system (CNS) and peripheral dopamine metabolism. Debrisoquin sulfate (DBQ) blocks peripheral, but not CNS, production of HVA from dopamine. Administration of DBQ has been used to decrease the proportion of peripherally produced HVA in pHVA measurements, making such measurements more reflective of CNS turnover of dopamine. We studied the relationships between DBQ dose, plasma DBQ (pDBQ) levels, and changes in pHVA in a group of 21 subjects (9 normal controls and 12 with Tourette's syndrome). DBQ dose was moderately correlated with pDBQ levels (r = 0.63, p = 0.002). Subjects (n = 8) with mean pDBQ levels above 60 ng/ml had a 48% to 66% decrease in mean pHVA levels; this may reflect nearly complete inhibition of peripheral HVA production. Subjects (n = 13) with mean pDBQ levels below 55 ng/ml had decreases in pHVA levels from 10% to 58%. No debrisoquin was detected in cerebrospinal fluid samples. These data suggest that pDBQ levels above 60 ng/ml are sufficient to assure substantial inhibition of peripheral HVA production and that monitoring pDBQ levels may be useful when employing this method for studying CNS metabolism.

  15. Reduction of aerobic and lactic acid bacteria in dairy desludge using an integrated compressed CO2 and ultrasonic process.

    Science.gov (United States)

    Overton, Tim W; Lu, Tiejun; Bains, Narinder; Leeke, Gary A

    Current treatment routes are not suitable to reduce and stabilise bacterial content in some dairy process streams such as separator and bactofuge desludges which currently present a major emission problem faced by dairy producers. In this study, a novel method for the processing of desludge was developed. The new method, elevated pressure sonication (EPS), uses a combination of low frequency ultrasound (20 kHz) and elevated CO 2 pressure (50 to 100 bar). Process conditions (pressure, sonicator power, processing time) were optimised for batch and continuous EPS processes to reduce viable numbers of aerobic and lactic acid bacteria in bactofuge desludge by ≥3-log fold. Coagulation of proteins present in the desludge also occurred, causing separation of solid (curd) and liquid (whey) fractions. The proposed process offers a 10-fold reduction in energy compared to high temperature short time (HTST) treatment of milk.

  16. Solar energy conversion and storage by using Rose Extract as natural dye and nitrilotriacetic acid as reductant in photogalvanic cell

    Science.gov (United States)

    Yadav, Sushil Kumar

    2018-05-01

    Photogalvanic effect was studied in Photogalvanic cell containing Rose Extract was used as Natural Dye (Photosensitizer), Nitrilotriacetic acid (NTA) as Reductant. The observed value of photopotential and photocurrent generated by this cell were 872 mV and 176 µA, respectively. The observed power at power point was 82.18 µW and the conversion efficiency was 0.79 %. The fill factor 0.4678 was experimentally determined at the power point of the cell. The photogalvanic cell can be used in dark for 42 min., showing the storage capacity of the cell against charging time was 200 min. The effect of different parameters on electrical output of the cell was observed and a mechanism has also been proposed for the generation of photocurrent in photogalvanic cell.

  17. Titrimetric determination of uranium in low-grade ores by the ferrous ion-phosphoric acid reduction method

    International Nuclear Information System (INIS)

    Hitchen, A.; Zechanowitsch, G.

    1980-01-01

    The modification and extension of the U.S.A.E.C. ferrous ion-phosphoric acid reduction method for the determination of uranium in high-grade or relatively pure material to a method for the determination of uranium with a high accuracy and precision, in ores containing 0.004 to 7% U is described. It is simple, rapid and requires no prior separations from elements that, in other methods, frequently interfere. For sample materials having very high concentrations of interfering elements, a prior concentration step using extraction with tri-n-octylphosphine oxide is described, but it is shown that, for most low-grade ores, this step is unnecessary. (author)

  18. Mechanistic insight into chromium(VI) reduction by oxalic acid in the presence of manganese(II)

    Energy Technology Data Exchange (ETDEWEB)

    Wrobel, Katarzyna; Corrales Escobosa, Alma Rosa; Gonzalez Ibarra, Alan Alexander; Mendez Garcia, Manuel; Yanez Barrientos, Eunice; Wrobel, Kazimierz, E-mail: kazimier@ugto.mx

    2015-12-30

    Over the past few decades, reduction of hexavalent chromium (Cr(VI)) has been studied in many physicochemical contexts. In this research, we reveal the mechanism underlying the favorable effect of Mn(II) observed during Cr(VI) reduction by oxalic acid using liquid chromatography with spectrophotometric diode array detector (HPLC–DAD), nitrogen microwave plasma atomic emission spectrometry (HPLC–MP-AES), and high resolution mass spectrometry (ESI–QTOFMS). Both reaction mixtures contained potassium dichromate (0.67 mM Cr(VI)) and oxalic acid (13.3 mM), pH 3, one reaction mixture contained manganese sulfate (0.33 mM Mn(II)). In the absence of Mn(II) only trace amounts of reaction intermediates were generated, most likely in the following pathways: (1) Cr(VI) → Cr(IV) and (2) Cr(VI) + Cr(IV) → 2Cr(V). In the presence of Mn(II), the active reducing species appeared to be Mn(II) bis-oxalato complex (J); the proposed reaction mechanism involves a one-electron transfer from J to any chromium compound containing Cr=O bond, which is reduced to Cr−OH, and the generation of Mn(III) bis-oxalato complex (K). Conversion of K to J was observed, confirming the catalytic role of Mn(II). Since no additional acidification was required, the results obtained in this study may be helpful in designing a new, environmentally friendly strategy for the remediation of environments contaminated with Cr(VI).

  19. Systematic review and meta-analyses of tranexamic acid use for bleeding reduction in prostate surgery.

    Science.gov (United States)

    Longo, Marcelo A; Cavalheiro, Bárbara T; de Oliveira Filho, Getúlio R

    2018-05-01

    Prostate cancer and benign prostatic hyperplasia have an increased incidence with aging. The most effective treatments are radical prostatectomy and transurethral resection of the prostate. To reduce perioperative bleeding in these surgeries, an approach is the use of tranexamic acid (TXA). Studies show that TXA is effective in reducing the blood loss and the need for transfusion in cardiac, orthopedic, and gynecological surgeries. In prostate surgeries, its efficacy and safety have not been established yet. To determine whether there are differences between TXA versus placebo in terms of intraoperative blood loss, transfusion requirements, hemoglobin levels and the incidence of thromboembolic events. Systematic review with meta-analyses. Anesthesia for prostate surgery. We searched the Medline, Cochrane, EBSCO, and Web of Science databases up to 2017 for randomized controlled trials that compared TXA administration with a control group in patients who submitted to prostate surgery. The primary outcomes were the intraoperative blood loss and transfusion rate. Data on hemoglobin levels and the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) were also collected. Nine comparative studies were included in the meta-analyses. The estimated blood loss and transfusion rate were lower in patients receiving TXA, with a standardized mean difference of -1.93 (95% CI = -2.81 to -1.05, I 2  = 96%), and a risk ratio of 0.61 (95% CI = 0.47 to 0.80, I 2  = 0%), respectively. The hemoglobin levels and the incidence of DVT and PE did not differ between the groups. TXA reduced intraoperative blood loss and the need for transfusion, without increasing the risk of DVT and PE in prostate surgeries. Due to the limited number of studies and the high heterogeneity of the results, more clinical trials with a large number of patients are necessary to confirm these findings. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Interleukin-2-induced survival of natural killer (NK) cells involving phosphatidylinositol-3 kinase-dependent reduction of ceramide through acid sphingomyelinase, sphingomyelin synthase, and glucosylceramide synthase.

    Science.gov (United States)

    Taguchi, Yoshimitsu; Kondo, Tadakazu; Watanabe, Mitsumasa; Miyaji, Michihiko; Umehara, Hisanori; Kozutsumi, Yasunori; Okazaki, Toshiro

    2004-11-15

    Interleukin 2 (IL-2) rescued human natural killer (NK) KHYG-1 cells from apoptosis along with a reduction of ceramide. Conversely, an increase of ceramide inhibited IL-2-rescued survival. IL-2 deprivation-induced activation of acid sphingomyelinase (SMase) and inhibition of glucosylceramide synthase (GCS) and sphingomyelin synthase (SMS) were normalized by IL-2 supplementation. A phosphatidyl inositol-3 (PI-3) kinase inhibitor, LY294002, inhibited IL-2-rescued survival, but a mitogen-activated protein kinase inhibitor, PD98059, and an inhibitor of Janus tyrosine kinase/signal transducer and activator of transcription pathway, AG490, did not. LY294002 inhibited IL-2-induced reduction of ceramide through activation of acid SMase and inhibition of GCS and SMS, suggesting the positive involvement of PI-3 kinase in ceramide reduction through enzymatic regulation. Indeed, a constitutively active PI-3 kinase enhanced growth rate and ceramide reduction through inhibition of acid SMase and activation of GCS and SMS. Further, LY294002 inhibited IL-2-induced changes of transcriptional level as well as mRNA and protein levels in acid SMase and GCS but did not affect the stability of the mRNAs. These results suggest that PI-3 kinase-dependent reduction of ceramide through regulation of acid SMase, GCS, and SMS plays a role in IL-2-rescued survival of NK cells.

  1. Chitinase Expression Due to Reduction in Fusaric Acid Level in an Antagonistic Trichoderma harzianum S17TH.

    Science.gov (United States)

    Sharma, Vivek; Bhandari, Pamita; Singh, Bikram; Bhatacharya, Amita; Shanmugam, Veerubommu

    2013-06-01

    To study the effect of reduction in phytotoxin level on fungal chitinases, antagonistic Trichoderma spp. were screened for their ability to reduce the level of fusaric acid (FA), the phytotoxin produced by Fusarium spp. A T. harzianum isolate S17TH was able to tolerate high levels of FA (up to 500 ppm) but was unable to reduce the toxin to a significant level (non-toxic) added to minimal synthetic broth (MSB). However, the isolate was able to reduce 400 ppm FA in the liquid medium after 7 days to a non-toxic level and displayed similar level of antagonism over the control (without FA). In studies of the effect of the reduction in FA (400 ppm) level on chitinase gene expression in PCR assays, nag1 was significantly repressed but ech42 expression was only slightly repressed. Chitinase activity was either reduced or absent in the extracellular proteins of MSB supplemented with 400 ppm FA, which could be attributed to the effect of residual FA or its breakdown products through unknown mechanisms. Selection of S17TH as a toxin insensitive isolate that could commensurate the negative effect on chitinase activity makes it a potential antagonist against Fusarium spp.

  2. Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles.

    Science.gov (United States)

    Hassan, Syeda Sara; Sirajuddin; Solangi, Amber Rehana; Agheem, Mohammad Hassan; Junejo, Yasmeen; Kalwar, Nazar Hussain; Tagar, Zulfiqar Ali

    2011-06-15

    We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Comparison of Two Methods of Bolus and Infusion of Tranexamic Acid in Reduction of Blood Loss in Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Mohammadreza Moshari

    2018-01-01

    Full Text Available AbstractBackground: So far, many studies have been performed to determine the optimal dose and regimen of tranexamic acid to reduce preoperative and postoperative blood loss in primary total knee arthroplasty. In the present study, two different methods of administration (bolus and infusion, were compared.Materials and Methods: Forty patients were randomized in the two groups (A and B of 20 patients each. All patients received 500 mg tranexamic acid before inflation of tourniquet. Group A (mean age, 64± 6.1 years received 500 mg tranexamic acid 10 minutes before loosening of tourniquet and group B (mean age, 63.5 ± 7.7 years received 500 mg tranexamic acid through IV infusion during 6 hours from the time of tourniquet loosening (total dose of TA, 1 g in both groups. Intraoperative blood loss,postoperative drainage (in 6 and 12 hours, blood transfusion (in 48 hours, and decrease in hematocrit and hemoglobin (6 and 12 hours later, were compared between the two groups.Results: The patients in group B had lower intra- and postoperative blood loss in 6 and 12 hours and also had lower decrease in hemoglobin, and their packed cell transfusion rate was significantly lower compared to the group A.Conclusion: The findings of this study indicated that infusion administration of tranexamic acid in primary total knee arthroplasty, was more effective in the reduction of perioperative blood loss as well as need for blood transfusion in 48 hours.

  4. Fundamental Mechanistic Understanding of Electrocatalysis of Oxygen Reduction on Pt and Non-Pt Surfaces: Acid versus Alkaline Media

    Directory of Open Access Journals (Sweden)

    Nagappan Ramaswamy

    2012-01-01

    Full Text Available Complex electrochemical reactions such as Oxygen Reduction Reaction (ORR involving multi-electron transfer is an electrocatalytic inner-sphere electron transfer process that exhibit strong dependence on the nature of the electrode surface. This criterion (along with required stability in acidic electrolytes has largely limited ORR catalysts to the platinum-based surfaces. New evidence in alkaline media, discussed here, throws light on the involvement of surface-independent outer-sphere electron transfer component in the overall electrocatalytic process. This surface non-specificity gives rise to the possibility of using a wide-range of non-noble metal surfaces as electrode materials for ORR in alkaline media. However, this outer-sphere process predominantly leads only to peroxide intermediate as the final product. The importance of promoting the electrocatalytic inner-sphere electron transfer by facilitation of direct adsorption of molecular oxygen on the active site is emphasized by using pyrolyzed metal porphyrins as electrocatalysts. A comparison of ORR reaction mechanisms between acidic and alkaline conditions is elucidated here. The primary advantage of performing ORR in alkaline media is found to be the enhanced activation of the peroxide intermediate on the active site that enables the complete four-electron transfer. ORR reaction schemes involving both outer- and inner-sphere electron transfer mechanisms are proposed.

  5. Effect of acid, steam explosion, and size reduction pretreatments on bio-oil production from sweetgum, switchgrass, and corn stover.

    Science.gov (United States)

    Wang, Hui; Srinivasan, Radhakrishnan; Yu, Fei; Steele, Philip; Li, Qi; Mitchell, Brian; Samala, Aditya

    2012-05-01

    Bio-oil produced from biomass by fast pyrolysis has the potential to be a valuable substitute for fossil fuels. In a recent work on pinewood, we found that pretreatment alters the structure and chemical composition of biomass, which influence fast pyrolysis. In this study, we evaluated dilute acid, steam explosion, and size reduction pretreatments on sweetgum, switchgrass, and corn stover feedstocks. Bio-oils were produced from untreated and pretreated feedstocks in an auger reactor at 450 °C. The bio-oil's physical properties of pH, water content, acid value, density, and viscosity were measured. The chemical characteristics of the bio-oils were determined by gas chromatography-mass spectrometry. The results showed that bio-oil yield and composition were influenced by the pretreatment method and feedstock type. Bio-oil yields of 52, 33, and 35 wt% were obtained from medium-sized (0.68-1.532 mm) untreated sweetgum, switchgrass, and corn stover, respectively, which were higher than the yields from other sizes. Bio-oil yields of 56, 46, and 51 wt% were obtained from 1% H(2)SO(4)-treated medium-sized sweetgum, switchgrass, and corn stover, respectively, which were higher than the yields from untreated and steam explosion treatments.

  6. Selective reductive leaching of cobalt and lithium from industrially crushed waste Li-ion batteries in sulfuric acid system.

    Science.gov (United States)

    Peng, Chao; Hamuyuni, Joseph; Wilson, Benjamin P; Lundström, Mari

    2018-06-01

    Recycling of valuable metals from secondary resources such as waste Li-ion batteries (LIBs) has recently attracted significant attention due to the depletion of high-grade natural resources and increasing interest in the circular economy of metals. In this article, the sulfuric acid leaching of industrially produced waste LIBs scraps with 23.6% cobalt (Co), 3.6% lithium (Li) and 6.2% copper (Cu) was investigated. The industrially produced LIBs scraps were shown to provide higher Li and Co leaching extractions compared to dissolution of corresponding amount of pure LiCoO 2 . In addition, with the addition of ascorbic acid as reducing agent, copper extraction showed decrease, opposite to Co and Li. Based on this, we propose a new method for the selective leaching of battery metals Co and Li from the industrially crushed LIBs waste at high solid/liquid ratio (S/L) that leaves impurities like Cu in the solid residue. Using ascorbic acid (C 6 H 8 O 6 ) as reductant, the optimum conditions for LIBs leaching were found to be T = 80 °C, t = 90 min, [H 2 SO 4 ] = 2 M, [C 6 H 8 O 6 ] = 0.11 M and S/L = 200 g/L. This resulted in leaching efficiencies of 95.7% for Li and 93.8% for Co, whereas in contrast, Cu extraction was only 0.7%. Consequently, the proposed leaching method produces a pregnant leach solution (PLS) with high Li (7.0 g/L) and Co (44.4 g/L) concentration as well as a leach residue rich in Cu (up to 12 wt%) that is suitable as a feed fraction for primary or secondary copper production. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Proteome-based systems biology analysis of the diabetic mouse aorta reveals major changes in fatty acid biosynthesis as potential hallmark in diabetes mellitus-associated vascular disease.

    Science.gov (United States)

    Husi, Holger; Van Agtmael, Tom; Mullen, William; Bahlmann, Ferdinand H; Schanstra, Joost P; Vlahou, Antonia; Delles, Christian; Perco, Paul; Mischak, Harald

    2014-04-01

    Macrovascular complications of diabetes mellitus are a major risk factor for cardiovascular morbidity and mortality. Currently, studies only partially described the molecular pathophysiology of diabetes mellitus-associated effects on vasculature. However, better understanding of systemic effects is essential in unraveling key molecular events in the vascular tissue responsible for disease onset and progression. Our overall aim was to get an all-encompassing view of diabetes mellitus-induced key molecular changes in the vasculature. An integrative proteomic and bioinformatics analysis of data from aortic vessels in the low-dose streptozotocin-induced diabetic mouse model (10 animals) was performed. We observed pronounced dysregulation of molecules involved in myogenesis, vascularization, hypertension, hypertrophy (associated with thickening of the aortic wall), and a substantial reduction of fatty acid storage. A novel finding is the pronounced downregulation of glycogen synthase kinase-3β (Gsk3β) and upregulation of molecules linked to the tricarboxylic acid cycle (eg, aspartate aminotransferase [Got2] and hydroxyacid-oxoacid transhydrogenase [Adhfe1]). In addition, pathways involving primary alcohols and amino acid breakdown are altered, potentially leading to ketone-body production. A number of these findings were validated immunohistochemically. Collectively, the data support the hypothesis that in this diabetic model, there is an overproduction of ketone-bodies within the vessels using an alternative tricarboxylic acid cycle-associated pathway, ultimately leading to the development of atherosclerosis. Streptozotocin-induced diabetes mellitus in animals leads to a reduction of fatty acid biosynthesis and an upregulation of an alternative ketone-body formation pathway. This working hypothesis could form the basis for the development of novel therapeutic intervention and disease management approaches.

  8. Advances in biotreatment of acid mine drainage and biorecovery of metals: 2. Membrane bioreactor system for sulfate reduction.

    Science.gov (United States)

    Tabak, Henry H; Govind, Rakesh

    2003-12-01

    Several biotreatmemt techniques for sulfate conversion by the sulfate reducing bacteria (SRB) have been proposed in the past, however few of them have been practically applied to treat sulfate containing acid mine drainage (AMD). This research deals with development of an innovative polypropylene hollow fiber membrane bioreactor system for the treatment of acid mine water from the Berkeley Pit, Butte, MT, using hydrogen consuming SRB biofilms. The advantages of using the membrane bioreactor over the conventional tall liquid phase sparged gas bioreactor systems are: large microporous membrane surface to the liquid phase; formation of hydrogen sulfide outside the membrane, preventing the mixing with the pressurized hydrogen gas inside the membrane; no requirement of gas recycle compressor; membrane surface is suitable for immobilization of active SRB, resulting in the formation of biofilms, thus preventing washout problems associated with suspended culture reactors; and lower operating costs in membrane bioreactors, eliminating gas recompression and gas recycle costs. Information is provided on sulfate reduction rate studies and on biokinetic tests with suspended SRB in anaerobic digester sludge and sediment master culture reactors and with SRB biofilms in bench-scale SRB membrane bioreactors. Biokinetic parameters have been determined using biokinetic models for the master culture and membrane bioreactor systems. Data are presented on the effect of acid mine water sulfate loading at 25, 50, 75 and 100 ml/min in scale-up SRB membrane units, under varied temperatures (25, 35 and 40 degrees C) to determine and optimize sulfate conversions for an effective AMD biotreatment. Pilot-scale studies have generated data on the effect of flow rates of acid mine water (MGD) and varied inlet sulfate concentrations in the influents on the resultant outlet sulfate concentration in the effluents and on the number of SRB membrane modules needed for the desired sulfate conversion in

  9. Solid-phase reduction of silico-12-molybdic acid H4SiMo12O40 by some organic oxygen containing compounds

    International Nuclear Information System (INIS)

    Chuvaev, V.F.; Pinchuk, I.N.; Spitsyn, V.I.

    1982-01-01

    A study is made on reduction reactions of anhydrous silico-12-molybdic acid by vapors of organic oxygen-containing compounds at 170 deg C: alcohols, simple carbonyl compounds. Methods of thermal analysis, electron paramagnetic resonance, paramagnetic resonance were used to established that depending on the nature of organic reagent and temperature, H 6 SiMo 2 5 Mo 10 6 O 40 two-electron or H 8 SiMo 4 5 Mo 8 6 O 40 four-electron flues form. It is shown that the increase of heterogeneous reduction temperature can lead to formation of anhydrous phases of SiMo 12 O 38 -(n/2), able to attach water reversibly with formation of corresponding blue. Characteristics of blues, prepared during solid-phase reduction of silico-12-molybdic acid and mixed valent forms with corresponding reduction degree, separated from water solutions, were compared

  10. REDUCTION OF EXCESS SLUDGE PRODUCTION IN AN ACTIVATED SLUDGE SYSTEM BASED ON LYSIS-CRYPTIC GROWTH, UNCOUPLING METABOLISM AND FOLIC ACID ADDITION

    Directory of Open Access Journals (Sweden)

    V. F. Velho

    Full Text Available Abstract The following sludge reduction alternatives were tested in wastewater biological reactors: oxic-settling-anaerobic (OSA-process; ultrasonic disintegration (UD; chlorination (CH; 3,3',4',5-tetrachlorosalicylanilide (TCS; and folic acid (FA. Compared to the control system, UD reduced 55% of the sludge production, and greater substrate and nutrient removal efficiency was achieved. CH worsened the sludge settleability and increased the SVI values; the system achieved 25% of sludge reduction. OSA showed 50% and 60% of sludge reduction after 16 and 10 hours under anaerobic conditions, respectively. The observed sludge yield during TCS addition was decreased by 40%, and the sludge settleability worsened. FA presented the highest sludge reduction (75%, and the system improved the nutrient removal efficiency by 30% compared to the control system and maintained the sludge properties. Acute toxicity conducted with Daphnia magna classified the effluent from the sludge reduction systems as non-toxic for discharge into water sources.

  11. Acidic electrolyzed water as a novel transmitting medium for high hydrostatic pressure reduction of bacterial loads on shelled fresh shrimp

    Directory of Open Access Journals (Sweden)

    Suping eDu

    2016-03-01

    Full Text Available Acidic electrolyzed water (AEW, a novel non-thermal sterilization technology, is widely used in the food industry. In this study, we firstly investigated the effect of AEW as a new pressure transmitting medium for high hydrostatic pressure (AEW-HHP processing on microorganisms inactivation on shelled fresh shrimp. The optimal conditions of AEW-HHP for Vibrio parahaemolyticus inactivation on sterile shelled fresh shrimp were obtained using response surface methodology: NaCl concentration to electrolysis 1.5 g/L, treatment pressure 400 MPa, treatment time 10 min. Under the optimal conditions mentioned above, AEW dramatically enhanced the efficiency of HHP for inactivating V. parahaemolyticus and Listeria monocytogenes on artificially contaminated shelled fresh shrimp, and the log reductions were up to 6.08 and 5.71 log10 CFU/g respectively, while the common HHP could only inactivate the two pathogens up to 4.74 and 4.31 log10 CFU/g respectively. Meanwhile, scanning electron microscopy (SEM showed the same phenomenon. For the naturally contaminated shelled fresh shrimp, AEW-HHP could also significantly reduce the micro flora when examined using plate count and PCR-DGGE. There were also no significant changes, histologically, in the muscle tissues of shrimps undergoing the AEW-HHP treatment. In summary, using AEW as a new transmitting medium for HHP processing is an innovative non thermal technology for improving the food safety of shrimp and other aquatic products.

  12. Acidic Electrolyzed Water as a Novel Transmitting Medium for High Hydrostatic Pressure Reduction of Bacterial Loads on Shelled Fresh Shrimp

    Science.gov (United States)

    Du, Suping; Zhang, Zhaohuan; Xiao, Lili; Lou, Yang; Pan, Yingjie; Zhao, Yong

    2016-01-01

    Acidic electrolyzed water (AEW), a novel non-thermal sterilization technology, is widely used in the food industry. In this study, we firstly investigated the effect of AEW as a new pressure transmitting medium for high hydrostatic pressure (AEW-HHP) processing on microorganisms inactivation on shelled fresh shrimp. The optimal conditions of AEW-HHP for Vibrio parahaemolyticus inactivation on sterile shelled fresh shrimp were obtained using response surface methodology: NaCl concentration to electrolysis 1.5 g/L, treatment pressure 400 MPa, treatment time 10 min. Under the optimal conditions mentioned above, AEW dramatically enhanced the efficiency of HHP for inactivating V. parahaemolyticus and Listeria monocytogenes on artificially contaminated shelled fresh shrimp, and the log reductions were up to 6.08 and 5.71 log10 CFU/g respectively, while the common HHP could only inactivate the two pathogens up to 4.74 and 4.31 log10 CFU/g respectively. Meanwhile, scanning electron microscopy (SEM) showed the same phenomenon. For the naturally contaminated shelled fresh shrimp, AEW-HHP could also significantly reduce the micro flora when examined using plate count and PCR-DGGE. There were also no significant changes, histologically, in the muscle tissues of shrimps undergoing the AEW-HHP treatment. In summary, using AEW as a new transmitting medium for HHP processing is an innovative non thermal technology for improving the food safety of shrimp and other aquatic products. PMID:27014228

  13. Proton conductive Pt-Co nanoparticles anchoring on citric acid functionalized graphene for efficient oxygen reduction reaction

    Science.gov (United States)

    Zhao, Yige; Liu, Jingjun; Wu, Yijun; Wang, Feng

    2017-08-01

    Designing highly efficient electro-catalysts for the oxygen reduction reaction (ORR) has been regarded as a demanding task in the development of renewable energy sources. However, little attention has been paid on improving Pt-based catalysts by promoting proton transfer from the electrolyte solutions to the catalyst layer at the cathode. Herein, we design proton conductive Pt-Co alloy nanoparticles anchoring on citric acid functionalized graphene (Pt-Co/CA-G) catalysts for efficient ORR. The facile modification approach for graphene can introduce oxygenated functional groups on the graphene surface to promote proton transfer as well as keeping the high electron conductivity without destroying the graphene original structure. The electrochemical results show that the Pt-Co/CA-G catalyst exhibits more excellent ORR activity and stability than the commercial Pt/C catalyst, which can be attributed to its improved proton transfer ability. The fast proton transfer comes from the hydrogen-bonding networks formed by the interaction between the oxygenated functional groups and water molecules. This work provides not only a novel and simple approach to modify graphene but also an effective strategy to improve Pt-based catalysts for the ORR.

  14. A novel method for synthesis of phosphomolybdic acid-modified Pd/C catalysts for oxygen reduction reaction

    Science.gov (United States)

    Zhu, Mingyuan; Gao, Xiaoling; Luo, Guangqin; Dai, Bin

    2013-03-01

    This manuscript reports a convenient method for immobilizing phosphomolybdic acid (HPMo) on polyaniline (PAN-) functionalized carbon supports. The obtained HPMo-PAN-C sample is used as the support to prepare a Pd/HPMo-PAN-C catalyst. The samples are characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray diffraction analysis. The results suggest that HPMo retains its Keggin structure and that the presence of HPMo reduces the average particle size of the Pd nano-particles in the obtained Pd/HPMo-PAN-C catalyst. Electro-chemical measurements in 0.5 M HClO4 solution reveal that the Pd/HPMo-PAN-C catalyst has higher catalytic activity for oxygen reduction reactions than does a Pd/C catalyst prepared using a similar procedure. The stability of the Pd/HPMo-PAN-C catalyst is evaluated by multiple-cycle voltammetry techniques; the mass catalytic activity decreases by only 10% after 100 scanning cycles.

  15. Plasma trans-fatty acid concentrations continue to be associated with metabolic syndrome among US adults after reductions in trans-fatty acid intake.

    Science.gov (United States)

    Zhang, Zefeng; Gillespie, Cathleen; Yang, Quanhe

    2017-07-01

    No study examined and compared the association between intake of trans-fatty acids (TFAs) and risk of metabolic syndrome before and after significant reduction of TFA intakes in the US population. We hypothesized that the relationship might remain significant after substantial reduction of TFA intakes in the population. We used data on 1442 and 2233 adults aged ≥20 years from the National Health and Nutrition Examination Survey 1999-2000 and 2009-2010, respectively. Multivariable logistic regression analysis was used to assess the association between plasma TFA concentrations and metabolic syndrome, including each of its 5 components. The median plasma TFA concentrations were reduced from 79.8 μmol/L in 1999-2000 to 36.9 μmol/L in 2009-2010. The fully adjusted prevalence ratios comparing the highest vs the lowest quintile of plasma TFA concentrations in 1999-2000 were 3.43 (95% confidence interval, 2.39-4.92) for metabolic syndrome, 1.72 (1.38-2.14) for large waistline, 8.25 (6.34-10.74) for high triglycerides, 1.96 (1.46-2.62) for low high-density lipoprotein cholesterol, 1.14 (0.85-1.55) for high blood pressure, and 1.48 (1.19-1.85) for high fasting glucose, respectively. The corresponding prevalence ratios in 2009-2010 were 2.93 (2.41-3.54), 1.62 (1.39-1.89), 14.93 (9.28-24.02), 3.09 (2.18-4.37), 1.27 (1.11-1.46), and 1.24 (1.06-1.46), respectively. The pattern of association between TFAs and metabolic syndrome and its components did not differ by cycles. The observed associations were consistent across the subgroups examined. Despite a 54% decline in plasma TFA concentrations from 1999-2000 to 2009-2010, it was positively associated with risk of metabolic syndrome and its individual components except for blood pressure in 1999-2000. Our findings support Food and Drug Administration initiatives to remove TFAs from the industrially-produced foods. Published by Elsevier Inc.

  16. Convergent synthesis of degradable dendrons based on L-malic acid

    DEFF Research Database (Denmark)

    Meyhoff, Ulrich; Riber, Ulla; Boas, Ulrik

    2015-01-01

    New degradable polyester dendrons based on the cellular tricarboxylic acid cycle component L-malic acid were synthesized up to the third generation by convergent synthesis. The dendron wedges could be introduced in a stepwise, highly regioselective fashion. HMBC-NMR revealed that the C1-carbonyl...

  17. Simulated solarlight catalytic reduction of Cr(VI) on microwave–ultrasonication synthesized flower-like CuO in the presence of tartaric acid

    International Nuclear Information System (INIS)

    Xu, Zhihui; Yu, Yaqun; Fang, Di; Liang, Jianru; Zhou, Lixiang

    2016-01-01

    In this study, flower-like CuO was successfully synthesized by a microwave–ultrasound assisted method and well characterized by X-ray diffractions, Fourier transform infrared spectrum, scanning electron microscopy, transmission electron microscopy, specific surface area, UV–vis diffused reflection spectra, X-ray photoelectron spectroscopy and point of zero charge. The photocatalytic performance of the as-prepared CuO was examined on the Cr(VI) reduction in the presence of tartaric acid under simulated solarlight irradiation. The results show that the developed CuO catalyst exhibited good photocatalytic activity with 100% reduction of Cr(VI) after irradiation of 30 min under the test condition of c(Cr(VI)) = 100 μM, catalyst loading = 400 mg/L, c(tartaric acid) = 4 mM and initial pH = 3. The reaction mechanism was proposed. The effects of test parameters, such as catalyst loading, tartaric acid concentration and initial pH, on Cr(VI) reduction efficiency were also investigated. It is worth mentioning that the developed catalyst can work at a relatively wide range of pH with quite high catalytic performance. - Highlights: • Flower-like CuO microstructure was prepared by MW-US assisted method. • The prepared CuO can catalyze the reduction Cr(VI) by tartaric acid under simulated solarlight. • The formation of ≡Cu(II)-tartaric acid complex play a key role in the reduction of Cr(VI). • The catalyst can operate effectively at a relatively wide range of pH.

  18. Randomized trial of amino acid mixture combined with physical activity promotion for abdominal fat reduction in overweight adults

    Directory of Open Access Journals (Sweden)

    Ueda K

    2018-02-01

    that in the placebo group (difference, 10.0 cm2; 95% confidence interval [CI]: 0.4–19.6 cm2; P=0.041. Comparable outcomes were obtained for the abdominal subcutaneous fat area (difference, 7.4 cm2; 95% CI: 0.1–14.7 cm2; P=0.047. No study-related unfavorable events occurred.Conclusion: A-mix supplementation in combination with physical activity promotion facilitated abdominal fat reduction in overweight adults. Keywords: amino acid supplementation, physical activity promotion, abdominal fat, randomized controlled trial

  19. Dissolution of Gold and Silver with Ammonium Thiosulfate from Mangano-Argentiferous Ores Treated in Acid-Reductive Conditions

    Science.gov (United States)

    Tiburcio Munive, G.; Encinas Romero, M. A.; Vazquez, V. M.; Valenzuela García, J. L.; Valenzuela Soto, A.; Coronado Lopez, J. H.

    2017-10-01

    A novel process was studied to extract economic metals from refractory ores that are difficult to leach with cyanide and ammonium thiosulfate, such as the well-known mangano argentiferous minerals, which are minerals of manganese, iron, and silver. The mineral under consideration originates from the tailings of the Monte del Favor, Hostotipaquillo Jalisco, Mexico. The sample was characterized by x-ray diffractometry, atomic absorption spectroscopy, scanning electron microscopy, and microanalysis by energy-dispersive x-ray spectroscopy. First, the material was passed through a 100-mesh screen, and then it was subjected to reductive leaching by varying the liquid-solid ( L/ S) ratio from 2:1 to 10:1 (observations were carried out at a ratio of 5:1, which yielded higher extraction of manganese). With H2SO4 and Na2SO3 as the reducing agents, manganese extraction of up to 96.05% was achieved during the first 3 h with a mineral head of manganese 3.58%, acid consumption of 90.74 g/L, and sulfite consumption of 25.8 g/L. The mineral was then filtered and proceeded to neutralize the acidity, reaching a pH of 8 with calcium hydroxide. Then, the material was subjected to a new leaching of gold and silver values with ammonium thiosulfate. The L/ S ratio was varied (1:1, 2:1, 3:1, 4:1), and the contact time and the concentration of ammonium thiosulfate was investigated, while controlling the pH using Ca(OH)2 and NH4Cl. An L/ S ratio of 2:1 showed the best extraction of silver (97.06%) and gold (86.66%), and the thiosulfate consumption was 10.36 g/L. The mineral head of gold and silver was 0.30 g/ton and 310 g/ton, respectively. The pH was maintained between 9.8 and 8.4, such that ammonium thiosulfate stabilized with lime, and ammonium chloride did not suffer any decomposition.

  20. U(VI) speciation and reduction in acid chloride fluids in hydrothermal conditions: from transport to deposition of uranium in unconformity-related deposits

    International Nuclear Information System (INIS)

    Dargent, Maxime

    2014-01-01

    Circulations of acidic chloride brines in the earth's crust are associated with several types of uranium deposits, particularly unconformity-related uranium (URU) deposits. The spectacular high grade combined with the large tonnage of these deposits is at the origin of the key questions concerning the geological processes responsible for U transport and precipitation. The aim of this work is to performed experimental studies of U(VI) speciation and its reduction to U(IV) subsequently precipitation to uraninite under hydrothermal condition. About uranium transport, the study of U(VI) speciation in acidic brines at high temperature is performed by Raman and XAS spectroscopy, showing the coexistence of several uranyl chloride complexes UO 2 Cl n 2-n (n = 0 - 5). From this study, complexation constants are proposed. The strong capability of chloride to complex uranyl is at the origin of the transport of U(VI) at high concentration in acidic chloride brines. Concerning uranium precipitation, the reactivity of four potential reductants under conditions relevant for URU deposits genesis is investigated: H 2 , CH 4 , Fe(II) and the C-graphite. The kinetics of reduction reaction is measured as a function of temperature, salinity, pH and concentration of reductant. H 2 , CH 4 , and the C-graphite are very efficient while Fe(II) is not able to reduce U(VI) in same conditions. The duration of the mineralizing event is controlled by (i) the U concentration in the ore-forming fluids and (ii) by the generation of gaseous reductants, and not by the reduction kinetics. These mobile and efficient gaseous reductant could be at the origin of the extremely focus and massive character of ore in URU deposits. Finally, first partition coefficients uraninite/fluid of trace elements are obtained. This last part opens-up new perspectives on (i) REE signatures interpretation for a given type of uranium deposit (ii) and reconstruction of mineralizing fluids composition. (author) [fr

  1. Understanding the complexity of trans fatty acid reduction in the American diet: American Heart Association Trans Fat Conference 2006: report of the Trans Fat Conference Planning Group.

    Science.gov (United States)

    Eckel, Robert H; Borra, Susan; Lichtenstein, Alice H; Yin-Piazza, Shirley Y

    2007-04-24

    A 2-day forum was convened to discuss the current status and future implications of reducing trans fatty acids without increasing saturated fats in the food supply while maintaining functionality and consumer acceptance of packaged, processed, and prepared foods. Attendees represented the agriculture and oilseed industry and oil processing, food manufacturing, food service, government, food technology, and health and nutrition disciplines. Presentations included food science behind fatty acid technology, the health science of dietary fatty acids, alternatives to trans fatty acids, and the use of alternatives in food manufacturing and food service. The reduction of trans fatty acids in the food supply is a complex issue involving interdependent and interrelated stakeholders. Actions to reduce trans fatty acids need to carefully consider both intended and unintended consequences related to nutrition and public health. The unintended consequence of greatest concern is that fats and oils high in saturated fats, instead of the healthier unsaturated fats, might be used to replace fats and oils with trans fatty acids. Many different options of alternative oils and fats to replace trans fatty acids are available or in development. Decisions on the use of these alternatives need to consider availability, health effects, research and development investments, reformulated food quality and taste, supply-chain management, operational modifications, consumer acceptance, and cost. The conference demonstrated the value of collaboration between the food industry and health and nutrition professionals, and this conference model should be used to address other food development, processing, and/or technology issues.

  2. Studies on the interference of hydrofluoric acid and phosphoric acid in the determination of uranium using Ti(III) reduction method-biamperometry end point

    International Nuclear Information System (INIS)

    Shiny, T.S.; Rajalakshmi, A.; Phal, D.G.; Charyulu, M.M.; Ramakumar, K.L.

    2007-01-01

    Accurate and precise determination of uranium in nuclear materials is necessary for chemical quality control as well as for nuclear material accounting purposes. Different types of uranium samples are received for the measurements. Depending upon the nature of the sample dissolution procedure is selected. Mixed oxide samples of uranium and plutonium, for example, are dissolved in nitric acid containing hydrofluoric acid under IR lamp. The fluoride ions are removed by repeated evaporation of the solution. However, some fluoride ions are left in the solutions depending on the conditions of evaporation. Uranium samples and alloy samples are dissolved in dilute hydrochloric acid. The rate of dissolution depends on concentration of acid. Sometimes a mixture of hydrochloric acid and hydrofluoric acid is used for the dissolution metal alloy samples, which may contain silica. Another method of dissolution of these samples is using a mixture of phosphoric acid and 1% hydrofluoric acid. It is necessary to study the interference of hydrofluoric acid and phosphoric acid on the determination of uranium

  3. Catalytic reduction of NH4NO3 by NO. Effects of solid acids and implications for low temperature DeNOx processes

    International Nuclear Information System (INIS)

    Savara, Aditya; Li, Mei-Jun; Sachtler, Wolfgang M.H.; Weitz, Eric

    2008-01-01

    Ammonium nitrate is thermally stable below 250 C and could potentially deactivate low temperature NO x reduction catalysts by blocking active sites. It is shown that NO reduces neat NH 4 NO 3 above its 170 C melting point, while acidic solids catalyze this reaction even at temperatures below 100 C. NO 2 , a product of the reduction, can dimerize and then dissociate in molten NH 4 NO 3 to NO + + NO 3 - , and may be stabilized within the melt as either an adduct or as HNO 2 formed from the hydrolysis of NO + or N 2 O 4 . The other product of reduction, NH 4 NO 2 , readily decomposes at ≤100 C to N 2 and H 2 O, the desired end products of DeNO x catalysis. A mechanism for the acid catalyzed reduction of NH 4 NO 3 by NO is proposed, with HNO 3 as an intermediate. These findings indicate that the use of acidic catalysts or promoters in DeNO x systems could help mitigate catalyst deactivation at low operating temperatures (<150 C). (author)

  4. The role of humic substances in the anaerobic reductive dechlorination of 2,4-dichlorophenoxyacetic acid by Comamonas koreensis strain CY01

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yibo [College of Life Sciences, South China Normal University, Guangdong Key Lab of Biotechnology for Plant Development, Guangzhou, 510631 (China)] [Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, 510650 (China)] [College of Life Science and Chemistry, Tianshui Normal University, Tianshui, 741000 (China); Wu Chunyuan [Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, 510650 (China); Wang Xiaojing, E-mail: wangyb02@163.com [College of Life Sciences, South China Normal University, Guangdong Key Lab of Biotechnology for Plant Development, Guangzhou, 510631 (China); Zhou Shungui, E-mail: sgzhou@soil.gd.cn [Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, 510650 (China)

    2009-05-30

    The role of the humic model compound, anthraquinone-2,6-disulfonate (AQDS), in the anaerobic reductive dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) by the Fe(III)- and humic substances (HS)-reducing bacterium, Comamonas koreensis strain CY01 was investigated. The results taken as a whole indicated that (i) strain CY01 could couple glucose oxidation to 2,4-D reductive dechlorination; (ii) reductive dechlorination of 2,4-D by strain CY01 was greatly stimulated by the addition of AQDS; (iii) the transfer of electrons from biogenic AH{sub 2}QDS to 2,4-D was an abiotic process which can take place in the absence of microorganisms; and (iv) AH{sub 2}QDS was reoxidized during the chemical reaction, AQDS can serve again as electron acceptor for microorganisms, thus acting as electron shuttles. All the results suggested that 2,4-D reductive dechlorination by CY01 strain was a biochemical process that oxidizes the electron donors and transfers the electron to the acceptors through redox mediator, AQDS. We proposed the possible mechanism for the HS dependent reduction of 2,4-D. Our results suggested that microbial reduction of HS and subsequent chemical reduction of organic pollutants represent an important path of electron flow in anoxic natural environments. This work is a necessary preliminary step for better understanding the biodegradation of 2,4-D in subsurface soil.

  5. Reduction-sensitive micelles self-assembled from amphiphilic chondroitin sulfate A-deoxycholic acid conjugate for triggered release of doxorubicin.

    Science.gov (United States)

    Liu, Hongxia; Wu, Shuqin; Yu, Jingmou; Fan, Dun; Ren, Jin; Zhang, Lei; Zhao, Jianguo

    2017-06-01

    Reduction-sensitive chondroitin sulfate A (CSA)-based micelles were developed. CSA was conjugated with deoxycholic acid (DOCA) via a disulfide linkage. The bioreducible conjugate (CSA-ss-DOCA) can form self-assembled micelles in aqueous medium. The critical micelle concentration (CMC) of CSA-ss-DOCA conjugate is 0.047mg/mL, and its mean diameter is 387nm. The anticancer drug doxorubicin (DOX) was chosen as a model drug, and was effectively encapsulated into the micelles with high loading efficiency. Reduction-sensitive micelles and reduction-insensitive control micelles displayed similar DOX release behavior in phosphate buffered saline (PBS, pH7.4). Notably, DOX release from the reduction-sensitive micelles in vitro was accelerated in the presence of 20mM glutathione-containing PBS environment. Moreover, DOX-loaded CSA-ss-DOCA (CSA-ss-DOCA/DOX) micelles exhibited intracellular reduction-responsive characteristics in human gastric cancer HGC-27 cells determined by confocal laser scanning microscopy (CLSM). Furthermore, CSA-ss-DOCA/DOX micelles demonstrated higher antitumor efficacy than reduction-insensitive control micelles in HGC-27 cells. These results suggested that reduction-sensitive CSA-ss-DOCA micelles had the potential as intracellular targeted carriers of anticancer drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A first principles study of interactions of CO{sub 2} with surfaces of a Cu(benzene‐1,3,5‐tricarboxylate) metal organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie, E-mail: jl3336@drexel.edu [Department of Materials Science & Engineering, Drexel University, Philadelphia, PA 19104 (United States); Zhu, Chenming [CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210 (China); Qiao, Zhen [Department of Chemistry, Drexel University, Philadelphia, PA 19104 (United States); Chen, Xinqing; Wei, Wei [CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210 (China); Ji, Haifeng [CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210 (China); Department of Chemistry, Drexel University, Philadelphia, PA 19104 (United States); Sohlberg, Karl [Department of Materials Science & Engineering, Drexel University, Philadelphia, PA 19104 (United States); Department of Chemistry, Drexel University, Philadelphia, PA 19104 (United States)

    2016-11-01

    Highlights: • DFT calculations are reported for a new Cu(benzene 1,3,5 tricarboxylate) MOF. • Neither of two low-index surfaces displays appreciable surface relaxation. • Strongest CO{sub 2} binding is to surface-exposed aryl groups. • Surface-exposed Cu atoms do not bind CO{sub 2} strongly, even if unsaturated. • Fitting the BET isotherm yields a binding energy in agreement with DFT calculations. - Abstract: Density functional theory is used to investigate the interaction of CO{sub 2} with the 100 and 010 surfaces of a Cu(benzene 1,3,5 tricarboxylate) metal organic framework. The calculation method is first validated by applying it to similar systems for which reliable results have been reported in literature and verifying that consistent results are obtained. The method is then applied to the Cu(benzene 1,3,5 tricarboxylate) system. The results show that neither the 100 or 010 surface undergoes major surface relaxation or surface reconstruction during structural optimization. CO{sub 2} adsorption calculations show that on the 100 surface, the CO{sub 2} molecule interacts with the surface benzene ring through π-π interaction. On the 010 surface, the interaction between the CO{sub 2} and the surface is again dominated by dispersion. Population analysis shows that a Cu atom on the 010 surface, even when nominally coordinatively unsaturated, is not electron deficient, which explains why CO{sub 2} does not bind to it chemically. Adsorption of multiple CO{sub 2} molecules on the 100 surface was also studied to investigate the dependence of the interaction on surface coverage. Least squares fitting of experimental adsorption versus pressure data to the BET isotherm model yields a binding energy in good agreement with the first-principles calculations.

  7. Microbial Reduction of Fe(III) in Acidic Sediments: Isolation of Acidiphilium cryptum JF-5 Capable of Coupling the Reduction of Fe(III) to the Oxidation of Glucose

    Science.gov (United States)

    Küsel, Kirsten; Dorsch, Tanja; Acker, Georg; Stackebrandt, Erko

    1999-01-01

    To evaluate the microbial populations involved in the reduction of Fe(III) in an acidic, iron-rich sediment, the anaerobic flow of supplemental carbon and reductant was evaluated in sediment microcosms at the in situ temperature of 12°C. Supplemental glucose and cellobiose stimulated the formation of Fe(II); 42 and 21% of the reducing equivalents that were theoretically obtained from glucose and cellobiose, respectively, were recovered in Fe(II). Likewise, supplemental H2 was consumed by acidic sediments and yielded additional amounts of Fe(II) in a ratio of approximately 1:2. In contrast, supplemental lactate did not stimulate the formation of Fe(II). Supplemental acetate was not consumed and inhibited the formation of Fe(II). Most-probable-number estimates demonstrated that glucose-utilizing acidophilic Fe(III)-reducing bacteria approximated to 1% of the total direct counts of 4′,6-diamidino-2-phenylindole-stained bacteria. From the highest growth-positive dilution of the most-probable-number series at pH 2.3 supplemented with glucose, an isolate, JF-5, that could dissimilate Fe(III) was obtained. JF-5 was an acidophilic, gram-negative, facultative anaerobe that completely oxidized the following substrates via the dissimilation of Fe(III): glucose, fructose, xylose, ethanol, glycerol, malate, glutamate, fumarate, citrate, succinate, and H2. Growth and the reduction of Fe(III) did not occur in the presence of acetate. Cells of JF-5 grown under Fe(III)-reducing conditions formed blebs, i.e., protrusions that were still in contact with the cytoplasmic membrane. Analysis of the 16S rRNA gene sequence of JF-5 demonstrated that it was closely related to an Australian isolate of Acidiphilium cryptum (99.6% sequence similarity), an organism not previously shown to couple the complete oxidation of sugars to the reduction of Fe(III). These collective results indicate that the in situ reduction of Fe(III) in acidic sediments can be mediated by heterotrophic Acidiphilium

  8. Microbial reduction of Fe(III) in acidic sediments: isolation of Acidiphilium cryptum JF-5 capable of coupling the reduction of Fe(III) to the oxidation of glucose.

    Science.gov (United States)

    Küsel, K; Dorsch, T; Acker, G; Stackebrandt, E

    1999-08-01

    To evaluate the microbial populations involved in the reduction of Fe(III) in an acidic, iron-rich sediment, the anaerobic flow of supplemental carbon and reductant was evaluated in sediment microcosms at the in situ temperature of 12 degrees C. Supplemental glucose and cellobiose stimulated the formation of Fe(II); 42 and 21% of the reducing equivalents that were theoretically obtained from glucose and cellobiose, respectively, were recovered in Fe(II). Likewise, supplemental H(2) was consumed by acidic sediments and yielded additional amounts of Fe(II) in a ratio of approximately 1:2. In contrast, supplemental lactate did not stimulate the formation of Fe(II). Supplemental acetate was not consumed and inhibited the formation of Fe(II). Most-probable-number estimates demonstrated that glucose-utilizing acidophilic Fe(III)-reducing bacteria approximated to 1% of the total direct counts of 4', 6-diamidino-2-phenylindole-stained bacteria. From the highest growth-positive dilution of the most-probable-number series at pH 2. 3 supplemented with glucose, an isolate, JF-5, that could dissimilate Fe(III) was obtained. JF-5 was an acidophilic, gram-negative, facultative anaerobe that completely oxidized the following substrates via the dissimilation of Fe(III): glucose, fructose, xylose, ethanol, glycerol, malate, glutamate, fumarate, citrate, succinate, and H(2). Growth and the reduction of Fe(III) did not occur in the presence of acetate. Cells of JF-5 grown under Fe(III)-reducing conditions formed blebs, i.e., protrusions that were still in contact with the cytoplasmic membrane. Analysis of the 16S rRNA gene sequence of JF-5 demonstrated that it was closely related to an Australian isolate of Acidiphilium cryptum (99.6% sequence similarity), an organism not previously shown to couple the complete oxidation of sugars to the reduction of Fe(III). These collective results indicate that the in situ reduction of Fe(III) in acidic sediments can be mediated by heterotrophic

  9. Continuous flow reduction of artemisinic acid utilizing multi-injection strategies-closing the gap towards a fully continuous synthesis of antimalarial drugs.

    Science.gov (United States)

    Pieber, Bartholomäus; Glasnov, Toma; Kappe, C Oliver

    2015-03-09

    One of the rare alternative reagents for the reduction of carbon-carbon double bonds is diimide (HN=NH), which can be generated in situ from hydrazine hydrate (N2H4⋅H2O) and O2. Although this selective method is extremely clean and powerful, it is rarely used, as the rate-determining oxidation of hydrazine in the absence of a catalyst is relatively slow using conventional batch protocols. A continuous high-temperature/high-pressure methodology dramatically enhances the initial oxidation step, at the same time allowing for a safe and scalable processing of the hazardous reaction mixture. Simple alkenes can be selectively reduced within 10-20 min at 100-120 °C and 20 bar O2 pressure. The development of a multi-injection reactor platform for the periodic addition of N2H4⋅H2O enables the reduction of less reactive olefins even at lower reaction temperatures. This concept was utilized for the highly selective reduction of artemisinic acid to dihydroartemisinic acid, the precursor molecule for the semisynthesis of the antimalarial drug artemisinin. The industrially relevant reduction was achieved by using four consecutive liquid feeds (of N2H4⋅H2O) and residence time units resulting in a highly selective reduction within approximately 40 min at 60 °C and 20 bar O2 pressure, providing dihydroartemisinic acid in ≥93% yield and ≥95% selectivity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Mitochondrial isocitrate dehydrogenase is inactivated upon oxidation and reactivated by thioredoxin-dependent reduction in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Keisuke eYoshida

    2014-09-01

    Full Text Available Regulation of mitochondrial metabolism is essential for ensuring cellular growth and maintenance in plants. Based on redox-proteomics analysis, several proteins involved in diverse mitochondrial reactions have been identified as potential redox-regulated proteins. NAD+-dependent isocitrate dehydrogenase (IDH, a key enzyme in the tricarboxylic acid cycle, is one such candidate. In this study, we investigated the redox regulation mechanisms of IDH by biochemical procedures. In contrast to mammalian and yeast counterparts reported to date, recombinant IDH in Arabidopsis mitochondria did not show adenylate-dependent changes in enzymatic activity. Instead, IDH was inactivated by oxidation treatment and partially reactivated by subsequent reduction. Functional IDH forms a heterodimer comprising regulatory (IDH-r and catalytic (IDH-c subunits. IDH-r was determined to be the target of oxidative modifications forming an oligomer via intermolecular disulfide bonds. Mass spectrometric analysis combined with tryptic digestion of IDH-r indicated that Cys128 and Cys216 are involved in intermolecular disulfide bond formation. Furthermore, we showed that mitochondria-localized o-type thioredoxin (Trx-o promotes the reduction of oxidized IDH-r. These results suggest that IDH-r is susceptible to oxidative stress, and Trx-o serves to convert oxidized IDH-r to the reduced form that is necessary for active IDH complex.

  11. Controllable size reduction of CdSe nanowires through the intermediate formation of Se-coated CdSe nanowires using acid and thermal treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lam, N S [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Wong, K W [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Li, Q [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Zheng, Z [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Lau, W M [Surface Science Western, University of Western Ontario, London, ON, N6A 5B7 (Canada)

    2007-10-17

    Thinning of CdSe nanowires (NWs) with controllable size was achieved by a simple acid treatment and subsequent annealing on thick CdSe NWs synthesized from vapour phase growth. During acid treatment, not only the undesired impurities such as native oxides of Cd and Se could be etched, but surface reactions of CdSe NWs were also observed, resulting in the formation of a layer of elemental Se around a thinner CdSe core. As a result, a heterostructure of Se - CdSe nanostructure formed after acid treatment of CdSe NWs. Upon thermal annealing, the Se shell was effectively removed and thinned stoichiometric single-crystalline CdSe NWs could be obtained. It was observed that NWs could be thinned by up to {approx}60% in diameter by acid treatment and subsequent Se thermal desorption. The degree of thinning was controllable by adjusting the duration of acid treatment. The success of the thinning of CdSe NWs by simple acid treatment and the annealing process reported here opens a new processing route for obtaining stoichiometric CdSe NWs with controllable size reduction and improved aspect ratio. This can undoubtedly broadly improve the range of applications of 1D CdSe nanostructures and allow more exploration of their uni-directional properties. A correction was made to the last paragraph of section 3 on 18 September 2007. The corrected electronic version is identical to the print version.

  12. Controllable size reduction of CdSe nanowires through the intermediate formation of Se-coated CdSe nanowires using acid and thermal treatment

    International Nuclear Information System (INIS)

    Lam, N S; Wong, K W; Li, Q; Zheng, Z; Lau, W M

    2007-01-01

    Thinning of CdSe nanowires (NWs) with controllable size was achieved by a simple acid treatment and subsequent annealing on thick CdSe NWs synthesized from vapour phase growth. During acid treatment, not only the undesired impurities such as native oxides of Cd and Se could be etched, but surface reactions of CdSe NWs were also observed, resulting in the formation of a layer of elemental Se around a thinner CdSe core. As a result, a heterostructure of Se - CdSe nanostructure formed after acid treatment of CdSe NWs. Upon thermal annealing, the Se shell was effectively removed and thinned stoichiometric single-crystalline CdSe NWs could be obtained. It was observed that NWs could be thinned by up to ∼60% in diameter by acid treatment and subsequent Se thermal desorption. The degree of thinning was controllable by adjusting the duration of acid treatment. The success of the thinning of CdSe NWs by simple acid treatment and the annealing process reported here opens a new processing route for obtaining stoichiometric CdSe NWs with controllable size reduction and improved aspect ratio. This can undoubtedly broadly improve the range of applications of 1D CdSe nanostructures and allow more exploration of their uni-directional properties. A correction was made to the last paragraph of section 3 on 18 September 2007. The corrected electronic version is identical to the print version

  13. Organic reactions for the electrochemical and photochemical production of chemical fuels from CO2--The reduction chemistry of carboxylic acids and derivatives as bent CO2 surrogates.

    Science.gov (United States)

    Luca, Oana R; Fenwick, Aidan Q

    2015-11-01

    The present review covers organic transformations involved in the reduction of CO2 to chemical fuels. In particular, we focus on reactions of CO2 with organic molecules to yield carboxylic acid derivatives as a first step in CO2 reduction reaction sequences. These biomimetic initial steps create opportunities for tandem electrochemical/chemical reductions. We draw parallels between long-standing knowledge of CO2 reactivity from organic chemistry, organocatalysis, surface science and electrocatalysis. We point out some possible non-faradaic chemical reactions that may contribute to product distributions in the production of solar fuels from CO2. These reactions may be accelerated by thermal effects such as resistive heating and illumination. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Reduction of inorganics from macroalgae Laminaria digitata and spent mushroom compost (SMC) by acid leaching and selective hydrothermal liquefaction

    DEFF Research Database (Denmark)

    Toor, Saqib Sohail; Jasiunas, Lukas; Xu, Chunbao (Charles)

    2018-01-01

    Hydrothermal liquefaction (HTL) is a promising route for producing bio-crude from various biomass feedstocks. However, high content of inorganic constituents in biomass like macroalgae Laminaria digitata and spent mushroom compost (SMC) affect the conversion process and the resulting fuel products....... This research studied the effects of different acid leaching treatments on such feedstocks, subsequent HTL, and bio-crude properties. Leaching treatments were performed using five different agents: deionized water, acetic acid, citric acid, sulfuric acid, and hydrochloric acid. Performance of leaching...... was evaluated by analyzing both leached biomass and HTL products by elemental analysis, ash content, inductively coupled plasma (ICP) analysis, and X-ray diffraction (XRD) analysis. Catalytic and non-catalytic HTL of both feedstocks before and after treatment were performed in a 10-mL microreactor at 400 °C...

  15. Removal of palladium precipitate from a simulated high-level radioactive liquid waste by reduction by ascorbic acid

    International Nuclear Information System (INIS)

    Kim, Eung Ho; Yoo, Jae Hyung; Choi, Cheong Song

    1998-01-01

    A study of the selective removal of Palladium from a simulated solution of high-level radioactive liquid waste (HLLW) was carried out. The simulated solution contained 7 representative elements (Pd 2+ , Cs + , Sr 2+ , Fe 3+ , MoO 2 2+ , Ru 4+ , and Nd 3+ ) typical of HLLW, ascorbic acid was added to the solution at room temperature. Pd 2+ in the simulated solution was easily reduced to Pd metal by the ascorbic acid and then the metal precipitate could be removed from the solution, whereas other elements remained mainly in solution. When the resulting Pd metal was left in solution, it was reoxidized to Pb 2+ ion and redissolved in a nitric acid medium. The oxidation rate of Pd 2+ depended on the presence of a transition metal such as ferric ion, and was also in proportion to the concentration of nitric acid and in inverse proportion to the concentration of ascrobic acid. (orig.)

  16. Brain mitochondrial metabolic dysfunction and glutamate level reduction in the pilocarpine model of temporal lobe epilepsy in mice

    Science.gov (United States)

    Smeland, Olav B; Hadera, Mussie G; McDonald, Tanya S; Sonnewald, Ursula; Borges, Karin

    2013-01-01

    Although certain metabolic characteristics such as interictal glucose hypometabolism are well established for temporal lobe epilepsy (TLE), its pathogenesis still remains unclear. Here, we performed a comprehensive study of brain metabolism in a mouse model of TLE, induced by pilocarpine–status epilepticus (SE). To investigate glucose metabolism, we injected mice 3.5–4 weeks after SE with [1,2-13C]glucose before microwave fixation of the head. Using 1H and 13C nuclear magnetic resonance spectroscopy, gas chromatography—mass spectrometry and high-pressure liquid chromatography, we quantified metabolites and 13C labeling in extracts of cortex and hippocampal formation (HF). Hippocampal levels of glutamate, glutathione and alanine were decreased in pilocarpine–SE mice compared with controls. Moreover, the contents of N-acetyl aspartate, succinate and reduced nicotinamide adenine dinucleotide (phosphate) NAD(P)H were decreased in HF indicating impairment of mitochondrial function. In addition, the reduction in 13C enrichment of hippocampal citrate and malate suggests decreased tricarboxylic acid (TCA) cycle turnover in this region. In cortex, we found reduced 13C labeling of glutamate, glutamine and aspartate via the pyruvate carboxylation and pyruvate dehydrogenation pathways, suggesting slower turnover of these amino acids and/or the TCA cycle. In conclusion, mitochondrial metabolic dysfunction and altered amino-acid metabolism is found in both cortex and HF in this epilepsy model. PMID:23611869

  17. Kinetic of the reduction of neptunium by hydrazine. Pt. 5. Reduction of Np(V) to Np(IV) in nitric acid media

    Energy Technology Data Exchange (ETDEWEB)

    Koltunov, V S; Tikhonov, M F; Shapovalov, M P

    1976-01-01

    The kinetics of the reaction between Np(V) and N/sub 2/H/sub 4/ in solutions of HNO/sub 3/+NaNO/sub 3/ was studied by a spectrophotometric method and an ionic strength ..mu..=4 in a broad range of N/sub 2/H/sub 4/ concentrations (0.01-1 M) at the temperatures 80 and 96/sup 0/C. It was shown that the order of the reaction with respect to Np(V) depends on the concentration of N/sub 2/H/sub 4/. At a low concentration (0.01-0.02 M), the reaction is second order with respect to Np(V), and its mechanism includes a slow step of disproportionation of NpO/sub 2//sup +/ ions. At a high concentration of N/sub 2/H/sub 4/ (1 M) the reaction is zero order with respect to Np(V), and its mechanism consists of the slow step of oxidation of N/sub 2/H/sub 4/ by nitric acid (by NO/sub 2//sup +/ ions) and the rapid steps of oxidation of the N/sub 2/H/sub 2/ radicals formed by NpO/sub 2//sup +/ ions and dimerization of radicals. A general kinetic equation was obtained for the reaction. Its parameters were determined with an electronic computer according to the results of experiments at ..mu..=4 and 90/sup 0/C: k/sub 2/=0.158+-0.017 M/sup -3/.min/sup -1/; k=(6.26+-1.79).10/sup -5/ M/sup -2/.min/sup -1/; K=(8.9+-39).10/sup -8/ M/sup -1/, and n=1.8+-0.4. The equation corresponds to the mechanism of the reaction.

  18. Particle size dependence on oxygen reduction reaction activity of electrodeposited TaOx catalysts in acidic media

    KAUST Repository

    Seo, J.; Cha, Dong Kyu; Takanabe, Kazuhiro; Kubota, J.; Domen, K.

    2013-01-01

    The size dependence of the oxygen reduction reaction activity was studied for TaOx nanoparticles electrodeposited on carbon black for application to polymer electrolyte fuel cells (PEFCs). Compared with a commercial Ta2O5 material, the ultrafine

  19. Relationships among oxidation-reduction and acid-base properties of the actinides in high oxidation states

    International Nuclear Information System (INIS)

    Morss, L.R.

    1992-01-01

    The first chemical identification of plutonium, its subsequent isolation on the macroscopic scale, and more recent chemical separation schemes were achieved by taking advantage of the differences among the oxidation states of uranium, neptunium, and plutonium. Many acid-base properties modify the relative stabilities of oxidation states of the actinides. In the solid state, strongly basic compounds such as Cs 2 O yield complex oxides with oxidation states of Np(VII), Pu(VI), and Am(VI) whereas more acidic compounds such as CsF yield complex fluorides with lower oxidation states. In aqueous solution, high basicity and strongly covalent complexes favor high oxidation states. In nonaqueous solvent systems, high acidity generally favors low oxidation states. This paper elucidates and attempts to interpret the effects of these acid-base properties in a systematic fashion

  20. Synthesis of high intrinsic loss power aqueous ferrofluids of iron oxide nanoparticles by citric acid-assisted hydrothermal-reduction route

    International Nuclear Information System (INIS)

    Behdadfar, Behshid; Kermanpur, Ahmad; Sadeghi-Aliabadi, Hojjat; Morales, Maria del Puerto; Mozaffari, Morteza

    2012-01-01

    Monodispersed aqueous ferrofluids of iron oxide nanoparticle were synthesized by hydrothermal-reduction route. They were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and dynamic light scattering. The results showed that certain concentrations of citric acid (CA) are required to obtain only magnetic iron oxides with mean particle sizes around 8 nm. CA acts as a modulator and reducing agent in iron oxide formation which controls nanoparticle size. The XRD, magnetic and heating measurements showed that the temperature and time of hydrothermal reaction can affect the magnetic properties of obtained ferrofluids. The synthesized ferrofluids were stable at pH 7. Their mean hydrodynamic size was around 80 nm with polydispersity index (PDI) of 0.158. The calculated intrinsic loss power (ILP) was 9.4 nHm 2 /kg. So this clean and cheap route is an efficient way to synthesize high ILP aqueous ferrofluids applicable in magnetic hyperthermia. - Graphical abstract: Monodispersed aqueous ferrofluids of iron oxide nanoparticles were synthesized by hydrothermal-reduction method with citric acid as reductant which is an efficient way to synthesize aqueous ferrofluids applicable in magnetic hyperthermia. Highlights: ► Aqueous iron oxide ferrofluids were synthesized by hydrothermal-reduction route. ► Citric acid acted as reducing agent and surfactant in the route. ► This is a facile, low energy and environmental friendly route. ► The aqueous iron oxide ferrofluids were monodispersed and stable at pH of 7. ► The calculated intrinsic loss power of the synthesized ferrofluids was very high.

  1. Microbial reduction of ferric iron oxyhydroxides as a way for remediation of grey forest soils heavily polluted with toxic metals by infiltration of acid mine drainage

    Science.gov (United States)

    Georgiev, Plamen; Groudev, Stoyan; Spasova, Irena; Nicolova, Marina

    2015-04-01

    The abandoned uranium mine Curilo is a permanent source of acid mine drainage (AMD) which steadily contaminated grey forest soils in the area. As a result, the soil pH was highly acidic and the concentration of copper, lead, arsenic, and uranium in the topsoil was higher than the relevant Maximum Admissible Concentration (MAC) for soils. The leaching test revealed that approximately half of each pollutant was presented as a reducible fraction as well as the ferric iron in horizon A was presented mainly as minerals with amorphous structure. So, the approach for remediation of the AMD-affected soils was based on the process of redoxolysis carried out by iron-reducing bacteria. Ferric iron hydroxides reduction and the heavy metals released into soil solutions was studied in the dependence on the source of organic (fresh or silage hay) which was used for growth and activity of soil microflora, initial soil pH (3.65; 4.2; and 5.1), and the ion content of irrigation solutions. The combination of limestone (2.0 g/ kg soil), silage addition (at rate of 45 g dry weight/ kg soil) in the beginning and reiterated at 6 month since the start of soil remediation, and periodical soil irrigation with slightly acidic solutions containing CaCl2 was sufficient the content of lead and arsenic in horizon A to be decreased to concentrations similar to the relevant MAC. The reducible, exchangeable, and carbonate mobile fractions were phases from which the pollutants was leached during the applied soil remediation. It determined the higher reduction of the pollutants bioavailability also as well as the process of ferric iron reduction was combined with neutralization of the soil acidity to pH (H2O) 6.2.

  2. Maternal dietary n-6 polyunsaturated fatty acid deprivation does not exacerbate post-weaning reductions in arachidonic acid and its mediators in the mouse hippocampus.

    Science.gov (United States)

    Alashmali, Shoug M; Kitson, Alex P; Lin, Lin; Lacombe, R J Scott; Bazinet, Richard P

    2017-09-13

    The present study examines how lowering maternal dietary n-6 polyunsaturated fatty acids (PUFA) (starting from pregnancy) compared to offspring (starting from post-weaning) affect the levels of n-6 and n-3 fatty acids in phospholipids (PL) and lipid mediators in the hippocampus of mice. Pregnant mice were randomly assigned to consume either a deprived or an adequate n-6 PUFA diet during pregnancy and lactation (maternal exposure). On postnatal day (PND) 21, half of the male pups were weaned onto the same diet as their dams, and the other half were switched to the other diet for 9 weeks (offspring exposure). At PND 84, upon head-focused high-energy microwave irradiation, hippocampi were collected for PL fatty acid and lipid mediator analyses. Arachidonic acid (ARA) concentrations were significantly decreased in both total PL and PL fractions, while eicosapentaenoic acid (EPA) concentrations were increased only in PL fractions upon n-6 PUFA deprivation of offspring, regardless of maternal exposure. Several ARA-derived eicosanoids were reduced, while some of the EPA-derived eicosanoids were elevated by n-6 PUFA deprivation in offspring. There was no effect of diet on docosahexaenoic acid (DHA) or DHA-derived docosanoids concentrations under either maternal or offspring exposure. These results indicate that the maternal exposure to dietary n-6 PUFA may not be as important as the offspring exposure in regulating hippocampal ARA and some lipid mediators. Results from this study will be helpful in the design of experiments aimed at testing the significance of altering brain ARA levels over different stages of life.

  3. Reconstruction of cytosolic fumaric acid biosynthetic pathways in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Xu Guoqiang

    2012-02-01

    Full Text Available Abstract Background Fumaric acid is a commercially important component of foodstuffs, pharmaceuticals and industrial materials, yet the current methods of production are unsustainable and ecologically destructive. Results In this study, the fumarate biosynthetic pathway involving reductive reactions of the tricarboxylic acid cycle was exogenously introduced in S. cerevisiae by a series of simple genetic modifications. First, the Rhizopus oryzae genes for malate dehydrogenase (RoMDH and fumarase (RoFUM1 were heterologously expressed. Then, expression of the endogenous pyruvate carboxylase (PYC2 was up-regulated. The resultant yeast strain, FMME-001 ↑PYC2 + ↑RoMDH, was capable of producing significantly higher yields of fumarate in the glucose medium (3.18 ± 0.15 g liter-1 than the control strain FMME-001 empty vector. Conclusions The results presented here provide a novel strategy for fumarate biosynthesis, which represents an important advancement in producing high yields of fumarate in a sustainable and ecologically-friendly manner.

  4. Detection and formation scenario of citric acid, pyruvic acid, and other possible metabolism precursors in carbonaceous meteorites

    Science.gov (United States)

    Cooper, George; Reed, Chris; Nguyen, Dang; Carter, Malika; Wang, Yi

    2011-01-01

    Carbonaceous meteorites deliver a variety of organic compounds to Earth that may have played a role in the origin and/or evolution of biochemical pathways. Some apparently ancient and critical metabolic processes require several compounds, some of which are relatively labile such as keto acids. Therefore, a prebiotic setting for any such individual process would have required either a continuous distant source for the entire suite of intact precursor molecules and/or an energetic and compact local synthesis, particularly of the more fragile members. To date, compounds such as pyruvic acid, oxaloacetic acid, citric acid, isocitric acid, and α-ketoglutaric acid (all members of the citric acid cycle) have not been identified in extraterrestrial sources or, as a group, as part of a “one pot” suite of compounds synthesized under plausibly prebiotic conditions. We have identified these compounds and others in carbonaceous meteorites and/or as low temperature (laboratory) reaction products of pyruvic acid. In meteorites, we observe many as part of three newly reported classes of compounds: keto acids (pyruvic acid and homologs), hydroxy tricarboxylic acids (citric acid and homologs), and tricarboxylic acids. Laboratory syntheses using 13C-labeled reactants demonstrate that one compound alone, pyruvic acid, can produce several (nonenzymatic) members of the citric acid cycle including oxaloacetic acid. The isotopic composition of some of the meteoritic keto acids points to interstellar or presolar origins, indicating that such compounds might also exist in other planetary systems. PMID:21825143

  5. Influence of NaCl and NaHCO/sub 3/ on reduction of phytic acid in red kidney bean

    International Nuclear Information System (INIS)

    Shahnawaz, M.; Khan, T.U.

    2007-01-01

    Influence of sodium chloride (NaCI) and sodium bicarbonate (NaHCO/sub 3/) was studied on phytic acid in Red kidney bean (phaseolus sp). Two varieties of Red Kidney bean VI (Orakzai Korkha) and V2 (Kurram Korkha) were obtained from NWFP Agriculture University, Peshawar. The amount of phytic acid in V1 and V2 of Red kidney bean was 10 mg and 9.80 mg, respectively. Red kidney-bean flour soaked for 6 and 12 hrs. in water and in pH4 and 6 solutions has significantly reduced (70%) amount of phytic acid. Solution of pH6 was found most effective, while pH4 and water was less effective in lowering the phytic acid in Red kidney bean. Mixed food additives (1% NaCI + 2% NaHCO/sub 3/) in water, and pH4 and 6 solutions, reduced the level of phytic acid in Red kidney bean to 40%, 54% and 58% for 6 hrs, and 50%, 57% and 70% for 12 hrs. in respective solutions. Results revealed that soaking Red kidney bean flour in pH6 solution with the presence of NaCI and NaHCO/sub 3/, the action of phytase enzyme was well activated to hydrolyze phytic acid. It has been observed that soaking of flour in the respective solutions is a simple inexpensive method of lowering phytic acid in bean. The treatment with such a sophisticated combination of food additives will improve the nutritional status of Red kidney bean, which is used in many food products. (author)

  6. Optimization of high free fatty acid reduction in mixed crude palm oils using circulation process through static mixer reactor and pilot-scale of two-step process

    International Nuclear Information System (INIS)

    Somnuk, Krit; Niseng, Suhdee; Prateepchaikul, Gumpon

    2014-01-01

    Highlights: • Reducing FFA in MCPO was circulated through static mixer alone in the lab-scale. • Methanol and sulfuric acid were varied in the esterification reaction. • RSM was employed to optimize the acid-catalyzed esterification in lab-scale. • 60 L of pilot-scale was designed on the basis of a simple operation and maintenance. - Abstract: High free fatty acid (FFA) reduction in mixed crude palm oil (MCPO) was performed with methanol (MeOH) and sulfuric acid (H 2 SO 4 ) as acid catalyst using the circulation process through static mixer reactor. In this study, the response surface methodology (RSM) was adopted to optimize the acid value in esterified oil after esterification process (first-step) in lab-scale. The results showed that acid value was reduced from 30 mgKOH g −1 to 2 mgKOH g −1 , when 19.8 vol.% MeOH, 2.0 vol.% H 2 SO 4 , reaction temperature 60 °C, 40 L h −1 of MCPO, 50 min reaction time, and 5-m of static mixer in length, were used in the lab-scale. This recommended condition was used to develop the pilot-scale process in which the scaling up of the FFA reduction from 5 L MCPO of lab-scale to 60 L MCPO of pilot-scale, which was designed on the basis of a simple operation and maintenance. In the pilot-scale process, the lower 1 mgKOH g −1 of acid value was achieved when it was conducted at the reaction time of 50 min. In the base-catalyzed transesterification (second-step) of pilot-scale process, the 98.65 wt.% of methyl ester purity was achieved when the following condition: 20 vol.% MeOH, 8 gKOH L −1 oil, and 60 min reaction time at 60 °C, was used to produce biodiesel

  7. One-pot syntheses of Li3V2(PO4)3/C cathode material for lithium ion batteries via ascorbic acid reduction approach

    International Nuclear Information System (INIS)

    Huang, J.S.; Yang, L.; Liu, K.Y.

    2011-01-01

    Highlights: → Ascorbic acid (C 6 H 8 O 6 ) was used as reducing agent and organic carbon source. → The strategy shortened the period of material preparation and lowered energy cost. → Li 3 V 2 (PO 4 ) 3 /C was obtained with enhanced electrochemical performance. → Effects of reagents on electrochemical performance of Li 3 V 2 (PO 4 ) 3 were evaluated. - Abstract: Monoclinic Li 3 V 2 (PO 4 ) 3 /C composite synthesized by ascorbic acid reduction method is examined as a cathode material for Li-ion batteries. Transmission electron microscopy (TEM) images show that the nano-size particles are obtained. The reversible capacity of Li 3 V 2 (PO 4 ) 3 /C prepared with LiOH and H 3 PO 4 is 141.2 mAh g -1 after 100 cycles at 1C discharge rate between 3 V and 4.8 V, and the retention rates of discharge capacity is 93.4%. Ascorbic acid plays not only as reduction reagent, but also as carbon sources. This strategy shortens the time of solid state reaction and facilitates the procedure of synthesis. Effects of different precursors materials on the performance of the Li 3 V 2 (PO 4 ) 3 /C are investigated.

  8. Comparison of Two Methods of Bolus and Infusion of Tranexamic Acid in Reduction of Blood Loss in Total Knee Arthroplasty

    OpenAIRE

    Mohammadreza Moshari; Bahman Malek; Mohammadreza Minator-Sajjadi; Maryam Vosoghian; Mastaneh Dahi; Mahshid Ghasemi; Razieh Shekari

    2018-01-01

    AbstractBackground: So far, many studies have been performed to determine the optimal dose and regimen of tranexamic acid to reduce preoperative and postoperative blood loss in primary total knee arthroplasty. In the present study, two different methods of administration (bolus and infusion), were compared.Materials and Methods: Forty patients were randomized in the two groups (A and B) of 20 patients each. All patients received 500 mg tranexamic acid before inflation of tourniquet. Group A (...

  9. Study of disulfide reduction and alkyl chloroformate derivatization of plasma sulfur amino acids using gas chromatography–mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Švagera, Z.; Hanzlíková, D.; Šimek, Petr; Hušek, Petr

    2012-01-01

    Roč. 402, č. 9 (2012), s. 2953-2963 ISSN 1618-2642 R&D Projects: GA MZd NS9755; GA ČR GAP206/10/2401; GA ČR GA203/09/2014 Institutional research plan: CEZ:AV0Z50070508 Keywords : plasma amino acids * disulfide-reducing agents * trichloroacetic acid deproteinization Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.659, year: 2012 http://www.springerlink.com/content/781wln3085q3v21r/

  10. The influence of ultrasound on the reduction of plutonium (4) by hydrazine and hydroxylamine in nitric acid and hydrochloric acid media

    International Nuclear Information System (INIS)

    Nikonov, M.V.; Shilov, V.P.

    1989-01-01

    Spectrophotometric method was used to study reduction of Pu(4) by hydrazine and hydroxylamine in HNO 3 and HCl solutions under the effect of ultrasonic waves at 18-20 deg C. It is shown that reaction of Pu(4) with hydrazine is accelerated in ultrasonic field approximately 10 times; ultrasound doesn't produce noticeable effect on behaviour of the actinoid in the case of hydroxylamine

  11. UPS and DFT investigation of the electronic structure of gas-phase trimesic acid

    Energy Technology Data Exchange (ETDEWEB)

    Reisberg, L., E-mail: rebban@ut.ee [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); Pärna, R. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); MAX IV Laboratory, Lund University, Fotongatan 2, 225 94 Lund (Sweden); Kikas, A.; Kuusik, I.; Kisand, V. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia); Hirsimäki, M.; Valden, M. [Surface Science Laboratory, Optoelectronics Research Centre, Tampere University of Technology, FIN-33101 Tampere (Finland); Nõmmiste, E. [Institute of Physics, University of Tartu, W. Oswaldi 1, EE-50411 Tartu (Estonia)

    2016-11-15

    Highlights: • In the current study outer valence band electronic structure of benzene-1,3,5-tricarboxylic acid was interpreted. • Experimental and calculated trimesic acid (TMA) spectrum were compared to ones of benzene and benzoic acid. • It is shown that similarities between MO energies and shapes for benzene and TMA exists. • Addition of carboxyl groups to the benzene ring clearly correlates with increasing binding energy of HOMO. - Abstract: Benzene-1,3,5-tricarboxylic acid (trimesic acid, TMA) molecules in gas-phase have been investigated by using valence band photoemission. The photoelectron spectrum in the binding energy region from 9 to 22 eV is interpreted by using density functional theory calculations. The electronic structure of TMA is compared with benzene and benzoic acid in order to demonstrate changes in molecular orbital energies induced by addition of carboxyl groups to benzene ring.

  12. Oxygen reduction reaction on a highly-alloyed Pt-Ni supported carbon electrocatalyst in acid solution

    CSIR Research Space (South Africa)

    Zheng, H

    2010-08-31

    Full Text Available Alloyed electrocatalysts such as PtNi/C[1-2], PtCo/C[3], PtCr/C[4], PtFe/C [5-6], and non-alloyed Pt-TiO2/C were reportedly investigated for methanol tolerance during Oxygen reduction reaction (ORR). The high methanol tolerance...

  13. Particle size dependence on oxygen reduction reaction activity of electrodeposited TaOx catalysts in acidic media

    KAUST Repository

    Seo, J.

    2013-11-13

    The size dependence of the oxygen reduction reaction activity was studied for TaOx nanoparticles electrodeposited on carbon black for application to polymer electrolyte fuel cells (PEFCs). Compared with a commercial Ta2O5 material, the ultrafine oxide nanoparticles exhibited a distinctively high onset potential different from that of the bulky oxide particles.

  14. Market Analysis DeN2O. Market potential for reduction of N2O emissions at nitric acid facilities

    International Nuclear Information System (INIS)

    Smit, A.W.; Gent, M.M.C.; Van den Brink, R.W.

    2001-05-01

    ECN has developed a technique for the removal of nitrous oxide (N2O) from the tail gases of a nitric acid plant. The aim of this project was to make an assessment of the market opportunities of this technique. To this end a study was made of the relevant international regulations and agreements on the field of climate policy. The formulation of an international greenhouse gas policy and concomitant flexible mechanisms is a prerequisite for the market introduction of any N2O abatement technique. The available techniques and techniques in development for N2O abatement in the nitric acid industry are described and the strengths and weaknesses are given. Furthermore, the costs per ton CO2 equivalents removed are estimated. Direct decomposition of N2O (either in the NH3 combustion reactor or downstream the absorber) are the most cost efficient techniques. Finally, the number and sizes of nitric acid plants in Europe and the developments in the fertiliser market are described. The current difficult fertiliser market makes the nitric acid producers reluctant to invest in N2O abatement technologies

  15. Electrocatalytic reduction of nitrate at low concentration on coinage and transition-metal electrodes in acid solutions

    NARCIS (Netherlands)

    Dima, G.E.; Vooys, de A.C.A.; Koper, M.T.M.

    2003-01-01

    A comparative study was performed to determine the reactivity of nitrate ions at 0.1 M on eight different polycrystalline electrodes (platinum, palladium, rhodium, ruthenium, iridium, copper, silver and gold) in acidic solution using cyclic voltammetry (CV), chronoamperometry and differential

  16. Solid-solution partitioning and thionation of diphenylarsinic acid in a flooded soil under the impact of sulfate and iron reduction

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Meng [Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Tu, Chen [Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Hu, Xuefeng; Zhang, Haibo [Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Lijuan [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Wei, Jing [Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Li, Yuan [Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Luo, Yongming, E-mail: ymluo@yic.ac.cn [Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Christie, Peter [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2016-11-01

    Diphenylarsinic acid (DPAA) is a major organic arsenic (As) compound derived from abandoned chemical weapons. The solid-solution partitioning and transformation of DPAA in flooded soils are poorly understood but are of great concern. The identification of the mechanisms responsible for the mobilization and transformation of DPAA may help to develop effective remediation strategies. Here, soil and Fe mineral incubation experiments were carried out to elucidate the partitioning and transformation of DPAA in anoxic (without addition of sulfate or sodium lactate) and sulfide (with the addition of sulfate and sodium lactate) soil and to examine the impact of sulfate and Fe(III) reduction on these processes. Results show that DPAA was more effectively mobilized and thionated in sulfide soil than in anoxic soil. At the initial incubation stages (0–4 weeks), 6.7–74.5% of the total DPAA in sulfide soil was mobilized likely by sorption competition with sodium lactate. At later incubation stage (4–8 weeks), DPAA was almost completely released into the solution likely due to the near-complete Fe(III) reduction. Scanning transmission X-ray microscopy (STXM) results provide further direct evidence of elevated DPAA release coupled with Fe(III) reduction in sulfide environments. The total DPAA fraction decreased significantly to 24.5% after two weeks and reached 3.4% after eight weeks in sulfide soil, whereas no obvious elimination of DPAA occurred in anoxic soil at the initial two weeks and the total DPAA fraction decreased to 10.9% after eight weeks. This can be explained in part by the enhanced mobilization of DPAA and sulfate reduction in sulfide soil compared with anoxic soil. These results suggest that under flooded soil conditions, Fe(III) and sulfate reduction significantly promote DPAA mobilization and thionation, respectively, and we suggest that it is essential to consider both sulfate and Fe(III) reduction to further our understanding of the environmental fate of

  17. l-Glutamic acid assisted eco-friendly one-pot synthesis of sheet-assembled platinum-palladium alloy networks for methanol oxidation and oxygen reduction reactions.

    Science.gov (United States)

    Shi, Ya-Cheng; Mei, Li-Ping; Wang, Ai-Jun; Yuan, Tao; Chen, Sai-Sai; Feng, Jiu-Ju

    2017-10-15

    In this work, bimetallic platinum-palladium sheet-assembled alloy networks (PtPd SAANs) were facilely synthesized by an eco-friendly one-pot aqueous approach under the guidance of l-glutamic acid at room temperature, without any additive, seed, toxic or organic solvent involved. l-Glutamic acid was served as the green shape-director and weak-stabilizing agent. A series of characterization techniques were employed to examine the morphology, structure and formation mechanism of the product. The architectures exhibited improved electrocatalytic activity and durable ability toward methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) in contrast with commercial Pt black and Pd black catalysts. This is ascribed to the unique structures of the obtained PtPd SAANs and the synergistic effects of the bimetals. These results demonstrate the potential application of the prepared catalyst in fuel cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. High-performance oxygen reduction catalysts in both alkaline and acidic fuel cells based on pre-treating carbon material and iron precursor

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ping; Barkholtz, Heather M.; Wang, Ying; Xu, Weilin; Liu, Dijia; Zhuang, Lin

    2017-12-01

    We demonstrate a new and simple method for pre-treating the carbon material and iron precursor to prepare oxygen reduction reaction (ORR) catalysts, which can produce super-high performance and stability in alkaline solution, with high performance in acid solution. This strategy using cheap materials is simply controllable. Moreover, it has achieved smaller uniform nanoparticles to exhibit high stability, and the synergetic effect of Fe and N offered much higher performance in ORR than commercial Pt/C, with high maximum power density in alkaline and acid fuel cell test. So it can make this kind of catalysts be the most promising alternatives of Pt-based catalysts with best performance/price.

  19. Reductive de-polymerization of kraft lignin for chemicals and fuels using formic acid as an in-situ hydrogen source.

    Science.gov (United States)

    Huang, Shanhua; Mahmood, Nubla; Tymchyshyn, Matthew; Yuan, Zhongshun; Xu, Chunbao Charles

    2014-11-01

    In this study, formic acid (FA) was employed as an in-situ hydrogen donor for the reductive de-polymerization of kraft lignin (KL). Under the optimum operating conditions, i.e., 300 °C, 1 h, 18.6 wt.% substrate concentration, 50/50 (v/v) water-ethanol medium with FA at a FA-to-lignin mass ratio of 0.7, KL (Mw∼10,000 g/mol) was effectively de-polymerized, producing de-polymerized lignin (DL, Mw 1270 g/mol) at a yield of ∼90 wt.% and polymerization of KL. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Reducing NO(x) emissions from a nitric acid plant of domestic petrochemical complex: enhanced conversion in conventional radial-flow reactor of selective catalytic reduction process.

    Science.gov (United States)

    Abbasfard, Hamed; Hashemi, Seyed Hamid; Rahimpour, Mohammad Reza; Jokar, Seyyed Mohammad; Ghader, Sattar

    2013-01-01

    The nitric acid plant of a domestic petrochemical complex is designed to annually produce 56,400 metric tons (based on 100% nitric acid). In the present work, radial-flow spherical bed reactor (RFSBR) for selective catalytic reduction of nitric oxides (NO(x)) from the stack of this plant was modelled and compared with the conventional radial-flow reactor (CRFR). Moreover, the proficiency of a radial-flow (water or nitrogen) membrane reactor was also compared with the CRFR which was found to be inefficient at identical process conditions. In the RFSBR, the space between the two concentric spheres is filled by a catalyst. A mathematical model, including conservation of mass has been developed to investigate the performance of the configurations. The model was checked against the CRFR in a nitric acid plant located at the domestic petrochemical complex. A good agreement was observed between the modelling results and the plant data. The effects of some important parameters such as pressure and temperature on NO(x) conversion were analysed. Results show 14% decrease in NO(x) emission annually in RFSBR compared with the CRFR, which is beneficial for the prevention of NO(x) emission, global warming and acid rain.

  1. Synthesis of aqueous ferrofluids of ZnxFe3−xO4 nanoparticles by citric acid assisted hydrothermal-reduction route for magnetic hyperthermia applications

    International Nuclear Information System (INIS)

    Behdadfar, Behshid; Kermanpur, Ahmad; Sadeghi-Aliabadi, Hojjat; Morales, Maria del Puerto; Mozaffari, Morteza

    2012-01-01

    Superparamagnetic and monodispersed aqueous ferrofluids of Zn substituted magnetite nanoparticles (Zn x Fe 3−x O 4 , x=0, 0.25, 0.3, 0.37 and 0.4) were synthesized via hydrothermal-reduction route in the presence of citric acid, which is a facile, low energy and environmental friendly method. The synthesized nanoparticles were characterized by X ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM and TEM) and the dynamic light scattering (DLS) method. The results showed that a certain amount of citric acid was required to obtain single phase Zn substituted magnetite nanoparticles. Citric acid acted as a modulator and reducing agent in the formation of spinel structure and controlled nanoparticle size and crystallinity. Mean particle sizes of the prepared nanoparticles were around 10 nm. The results that are obtained from XRD, magnetic and power loss measurements showed that the crystallinity, saturation magnetization (M S ) and loss power of the synthesized ferrofluids were all influenced by the substitution of Zn in the structure of magnetite. The Zn substituted magnetite nanoparticles obtained by this route showed a good stability in aqueous medium (pH 7) and hydrodynamic sizes below 100 nm and polydispersity indexes below 0.2. The calculated intrinsic loss power (ILP) for the sample x=0.3 (e.g. 2.36 nH m 2 /kg) was comparable to ILP of commercial ferrofluids with similar hydrodynamic sizes. - Highlights: ► We synthesized Zn substituted magnetite nanoparticles via hydrothermal-reduction route. ► We used citric acid as a reducing agent in this route. ► This route is a facile, low energy and environmental friendly method. ► The nanoparticles obtained by this route were superparamagnetic and stable in water. ► The calculated intrinsic loss power for the sample x=0.3 was 2.36 nH m 2 /kg.

  2. Reduction of As(V) to As(III) by commercial ZVI or As(0) with acid-treated ZVI

    International Nuclear Information System (INIS)

    Sun, Fenglong; Osseo-Asare, Kwadwo A.; Chen, Yongsheng; Dempsey, Brian A.

    2011-01-01

    Graphical abstract: Acid-treated ZVI (right) reduced As(V) to the less toxic As(0) while commercial ZVI reduced As(V) to As(III). There was no lag phase in either reaction when rigorously anoxic conditions were maintained. Highlights: ► Acid-treated ZVI reduced As(V) to the less toxic As(0). ► Commercial ZVI reduced As(V) to As(III), which was not released to solution. ► Magnetite/Fe(II) did not reduce As(V) even though the reaction is thermodynamically spontaneous. ► No lag phase was observed in any of the reactions, contrary to prior reports. ► Rigorously anoxic conditions seem necessary for observing these reactions. - Abstract: Zero-valent iron (ZVI) consists of an elemental iron core surrounded by a shell of corrosion products, especially magnetite. ZVI is used for in situ removal or immobilization of a variety of contaminants but the mechanisms for removal of arsenic remain controversial and the mobility of arsenic after reaction with ZVI is uncertain. These issues were addressed by separately studying reactions of As(V) with magnetite, commercial ZVI, and acid-treated ZVI. Strictly anoxic conditions were used. Adsorption of As(V) on magnetite was fast with pH dependence similar to previous reports using oxic conditions. As(V) was not reduced by magnetite and Fe(II) although the reaction is thermodynamically spontaneous. As(V) reactions with ZVI were also fast and no lag phase was observed which was contrary to previous reports. Commercial ZVI reduced As(V) to As(III) only when As(V) was adsorbed, i.e., for pH < 7. As(III) was not released to solution. Acid-treated ZVI reduced As(V) to As(0), shown using wet chemical analyses and XANES/EXAFS. Comparisons were drawn between reactivity of acid-treated ZVI and nano-ZVI; if true then acid-treated ZVI could provide similar reactive benefits at lower cost.

  3. Antifracture efficacy and reduction of mortality in relation to timing of the first dose of zoledronic acid after hip fracture

    DEFF Research Database (Denmark)

    Eriksen, Erik Fink; Lyles, Kenneth W; Colón-Emeric, Cathleen S

    2009-01-01

    undergone surgical repair of hip fracture. In this analysis, we examined whether timing of the first infusion of zoledronic acid study drug after hip fracture repair influenced the antifracture efficacy and mortality benefit observed in the study. A total of 2127 patients (1065 on active treatment and 1062...... was approximately 6 wk. Posthoc analyses were performed by dividing the study population into 2-wk intervals (calculated from time of first infusion in relation to surgical repair) to examine effects on BMD, fracture, and mortality. Analysis by 2-wk intervals showed a significant total hip BMD response......Annual infusions of zoledronic acid (5 mg) significantly reduced the risk of vertebral, hip, and nonvertebral fractures in a study of postmenopausal women with osteoporosis and significantly reduced clinical fractures and all-cause mortality in another study of women and men who had recently...

  4. Plan for injection of coal combustion byproducts into the Omega Mine for the reduction of acid mine drainage

    International Nuclear Information System (INIS)

    Gray, T.A.; Moran, T.C.; Broschart, D.W.; Smith, G.A.

    1998-01-01

    The Omega Mine Complex is located outside of Morgantown, West Virginia. The mine is in the Upper Freeport Coal, an acid-producing coal seam. The coal was mined in a manner that has resulted in acid mine drainage (AMD) discharges at multiple points. During the 1990's, the West Virginia Division of Environmental Protection (WVDEP) assumed responsibility for operating a collection and treatment system for the AMD. Collection and treatment costs are approximately $300,000 per year. Injecting grout into the mine workings to reduce AMD (and thus reducing treatment costs) is proposed. The procedure involves injecting grout mixes composed primarily of coal combustion byproducts (CCB's) and water, with a small quantity of cement. The intention of the injection program is to fill the mine voids in the north lobe of the Omega Mine (an area where most of the acidity is believed to be generated) with the grout, thus reducing the contact of air and water with potentially acidic material. The grout mix design consists of an approximate 1:1 ratio of fly ash to byproducts from fluidized bed combustion. Approximately 100 gallons of water per cubic yard of grout is used to achieve flowability. Observation of the mine workings via subsurface borings and downhole video camera confirmed that first-mined areas were generally open while second-mined areas were generally partially collapsed. The injection program was developed to account for this by utilizing closer injection hole spacing in second-mined areas. Construction began in January 1998, with grout injection expected to commence in mid-April 1998

  5. Reduction in uptake by rice and soybean of aromatic arsenicals from diphenylarsinic acid contaminated soil amended with activated charcoal

    International Nuclear Information System (INIS)

    Arao, Tomohito; Maejima, Yuji; Baba, Koji

    2011-01-01

    Activated charcoal (AC) amendment has been suggested as a promising method to immobilize organic contaminants in soil. We performed pot experiments with rice and soybean grown in agricultural soil polluted by aromatic arsenicals (AAs). The most abundant AA in rice grains and soybean seeds was methylphenylarsinic acid (MPAA). MPAA concentration in rice grains was significantly reduced to 2% and 3% in 0.2% AC treated soil compared to untreated soil in the first year of rice cultivation. In the second year, MPAA concentration in rice grains was significantly reduced to 15% in 0.2% AC treated soil compared to untreated soil. MPAA concentration in soybean seeds was significantly reduced to 44% in 0.2% AC treated soil compared to untreated soil. AC amendment was effective in reducing AAs in rice and soybean. - Highlights: → Pot experiments using agricultural soil contaminated with aromatic arsenicals (AAs). → Methylphenylarsinic acid (MPAA) was the most abundant AA in rice and soybean. → MPAA concentration in rice grains was dramatically reduced via 0.2% AC amendment. → MPAA concentration in soybean seeds was also reduced via 0.2% AC amendment. → AC amendment effectively reduced AAs in rice and soybean. - Activated charcoal amendment to soil contaminated with diphenylarsinic acid reduced aromatic arsenicals in rice and soybean.

  6. Reduction in uptake by rice and soybean of aromatic arsenicals from diphenylarsinic acid contaminated soil amended with activated charcoal

    Energy Technology Data Exchange (ETDEWEB)

    Arao, Tomohito, E-mail: arao@affrc.go.jp [National Institute for Agro-Environmental Sciences, Soil Environmental Division, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 (Japan); Maejima, Yuji; Baba, Koji [National Institute for Agro-Environmental Sciences, Soil Environmental Division, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 (Japan)

    2011-10-15

    Activated charcoal (AC) amendment has been suggested as a promising method to immobilize organic contaminants in soil. We performed pot experiments with rice and soybean grown in agricultural soil polluted by aromatic arsenicals (AAs). The most abundant AA in rice grains and soybean seeds was methylphenylarsinic acid (MPAA). MPAA concentration in rice grains was significantly reduced to 2% and 3% in 0.2% AC treated soil compared to untreated soil in the first year of rice cultivation. In the second year, MPAA concentration in rice grains was significantly reduced to 15% in 0.2% AC treated soil compared to untreated soil. MPAA concentration in soybean seeds was significantly reduced to 44% in 0.2% AC treated soil compared to untreated soil. AC amendment was effective in reducing AAs in rice and soybean. - Highlights: > Pot experiments using agricultural soil contaminated with aromatic arsenicals (AAs). > Methylphenylarsinic acid (MPAA) was the most abundant AA in rice and soybean. > MPAA concentration in rice grains was dramatically reduced via 0.2% AC amendment. > MPAA concentration in soybean seeds was also reduced via 0.2% AC amendment. > AC amendment effectively reduced AAs in rice and soybean. - Activated charcoal amendment to soil contaminated with diphenylarsinic acid reduced aromatic arsenicals in rice and soybean.

  7. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P. [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Gurinov, Andrey [Research Resources Center for Magnetic Resonance, Saint Petersburg State University, Universitetskij pr. 26, 198504 St. Petersburg (Russian Federation); Ortiz, Genaro Gabriel [Laboratorio Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano de Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Carbajal Arízaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.mx [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico)

    2015-03-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488 nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. - Highlights: • Hydroxyapatite functionalized with glucuronic acid reduced oxidative stress in rats. • Functionalization with folic acid reduced oxidative stress in rats. • Dysprosium doping does not affect the crystalline structure of hydroxyapatite. • Dysprosium doped particles are visible in fluorescent microscope. • Dysprosium doped particles act as MRI contrast agents.

  8. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids

    International Nuclear Information System (INIS)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P.; Gurinov, Andrey; Ortiz, Genaro Gabriel; Carbajal Arízaga, Gregorio Guadalupe

    2015-01-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488 nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. - Highlights: • Hydroxyapatite functionalized with glucuronic acid reduced oxidative stress in rats. • Functionalization with folic acid reduced oxidative stress in rats. • Dysprosium doping does not affect the crystalline structure of hydroxyapatite. • Dysprosium doped particles are visible in fluorescent microscope. • Dysprosium doped particles act as MRI contrast agents

  9. Effect of a sustained reduction in plasma free fatty acid concentration on insulin signalling and inflammation in skeletal muscle from human subjects.

    Science.gov (United States)

    Liang, Hanyu; Tantiwong, Puntip; Sriwijitkamol, Apiradee; Shanmugasundaram, Karthigayan; Mohan, Sumathy; Espinoza, Sara; Defronzo, Ralph A; Dubé, John J; Musi, Nicolas

    2013-06-01

    Free fatty acids (FFAs) have been implicated in the pathogenesis of insulin resistance. Reducing plasma FFA concentration in obese and type 2 diabetic (T2DM) subjects improves insulin sensitivity. However, the molecular mechanism by which FFA reduction improves insulin sensitivity in human subjects is not fully understood. In the present study, we tested the hypothesis that pharmacological FFA reduction enhances insulin action by reducing local (muscle) inflammation, leading to improved insulin signalling. Insulin-stimulated total glucose disposal (TGD), plasma FFA species, muscle insulin signalling, IBα protein, c-Jun phosphorylation, inflammatory gene (toll-like receptor 4 and monocyte chemotactic protein 1) expression, and ceramide and diacylglycerol (DAG) content were measured in muscle from a group of obese and T2DM subjects before and after administration of the antilipolytic drug acipimox for 7 days, and the results were compared to lean individuals. We found that obese and T2DM subjects had elevated saturated and unsaturated FFAs in plasma, and acipimox reduced all FFA species. Acipimox-induced reductions in plasma FFAs improved TGD and insulin signalling in obese and T2DM subjects. Acipimox increased IBα protein (an indication of decreased IB kinase-nuclear factor B signalling) in both obese and T2DM subjects, but did not affect c-Jun phosphorylation in any group. Acipimox also decreased inflammatory gene expression, although this reduction only occurred in T2DM subjects. Ceramide and DAG content did not change. To summarize, pharmacological FFA reduction improves insulin signalling in muscle from insulin-resistant subjects. This beneficial effect on insulin action could be related to a decrease in local inflammation. Notably, the improvements in insulin action were more pronounced in T2DM, indicating that these subjects are more susceptible to the toxic effect of FFAs.

  10. Deoxyribonucleic acid directed metallization of platinum nanoparticles on graphite nanofibers as a durable oxygen reduction catalyst for polymer electrolyte fuel cells

    Science.gov (United States)

    Peera, S. Gouse; Sahu, A. K.; Arunchander, A.; Nath, Krishna; Bhat, S. D.

    2015-11-01

    Effective surface functionalization to the hydrophobic graphite nanofibers (GNF) is performed with the biomolecule, namely deoxy-ribo-nucleic-acid (DNA) via π-π interactions. Pt nanoparticles are impregnated on GNF-DNA composite by ethylene glycol reduction method (Pt/GNF-DNA) and its effect on electro catalytic activity for oxygen reduction reaction (ORR) is systemically studied. Excellent dispersion of Pt nanoparticles over GNF-DNA surfaces with no evidence on particle aggregation is a remarkable achievement in this study. This result in higher electro chemical surface area of the catalyst, enhanced ORR behavior with significant enhancement in mass activity. The catalyst is validated in H2-O2 polymer electrolyte fuel cell (PEFC) and a peak power density of 675 mW cm-2 is achieved at a load current density of 1320 mA cm-2 with a minimal catalyst loading of 0.1 mg cm-2 at a cell temperature of 70 °C and 2 bar absolute pressure. Repeated potential cycling up to 10000 cycles in acidic media is also performed for this catalyst and found excellent stability with only 60 mV drop in the ORR half wave potential. The superior behavior of Pt/GNF-DNA catalyst is credited to the robust fibrous structure of GNF and its effective surface functionalization process via π-π interaction.

  11. Phytoproteins in green leaves as building blocks for photosynthesis of gold nanoparticles: An efficient electrocatalyst towards the oxidation of ascorbic acid and the reduction of hydrogen peroxide.

    Science.gov (United States)

    Megarajan, Sengan; Ayaz Ahmed, Khan Behlol; Rajendra Kumar Reddy, G; Suresh Kumar, P; Anbazhagan, Veerappan

    2016-02-01

    Herein, we present a simple and green method for the synthesis of gold nanoparticles (AuNPs) using the phytoproteins of spinach leaves. Under ambient sunlight irradiation, the isolated phytoprotein complex from spinach leaves reduces the gold chloride aqueous solution and stabilizes the formed AuNPs. As prepared nanoparticles were characterized by UV-visible spectroscopy, Fourier transform infra-red (FTIR) spectroscopy, zeta potential, transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDS). The surface plasmon resonance (SPR) maximum for AuNPs was observed at 520 nm. The zeta potential value estimated for the AuNPs is -27.0 mV, indicating that the NPs are well separated. Transmission electron micrographs revealed that the particles are spherical in nature with the size range from 10 to 15 nm. AuNPs act as a catalyst in the degradation of an azo dye, methyl orange in an aqueous environment. The reduction rate was determined to be pseudo-first order. Electrocatalytic efficiency of the synthesized AuNPs via this green approach was studied by chronoamperometry using ascorbic acid and hydrogen peroxide as a model compound for oxidation and reduction, respectively. Electrocatalytic studies indicate that the gold nanoparticles can be used to detect ascorbic acid and hydrogen peroxide in micromolar concentrations with response time less than 3s. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Exogenous retinoic acid induces digit reduction in opossums (Monodelphis domestica) by disrupting cell death and proliferation, and apical ectodermal ridge and zone of polarizing activity function.

    Science.gov (United States)

    Molineaux, Anna C; Maier, Jennifer A; Schecker, Teresa; Sears, Karen E

    2015-03-01

    Retinoic acid (RA) is a vitamin A derivative. Exposure to exogenous RA generates congenital limb malformations (CLMs) in species from frogs to humans. These CLMs include but are not limited to oligodactyly and long-bone hypoplasia. The processes by which exogenous RA induces CLMs in mammals have been best studied in mouse, but as of yet remain unresolved. We investigated the impact of exogenous RA on the cellular and molecular development of the limbs of a nonrodent model mammal, the opossum Monodelphis domestica. Opossums exposed to exogenous retinoic acid display CLMs including oligodactly, and results are consistent with opossum development being more susceptible to RA-induced disruptions than mouse development. Exposure of developing opossums to exogenous RA leads to an increase in cell death in the limb mesenchyme that is most pronounced in the zone of polarizing activity, and a reduction in cell proliferation throughout the limb mesenchyme. Exogenous RA also disrupts the expression of Shh in the zone of polarizing activity, and Fgf8 in the apical ectodermal ridge, and other genes with roles in the regulation of limb development and cell death. Results are consistent with RA inducing CLMs in opossum limbs by disrupting the functions of the apical ectodermal ridge and zone of polarizing activity, and driving an increase in cell death and reduction of cell proliferation in the mesenchyme of the developing limb. © 2015 Wiley Periodicals, Inc.

  13. Flexible graphene/carbon nanotube hybrid papers chemical-reduction-tailored by gallic acid for high-performance electrochemical capacitive energy storages

    Science.gov (United States)

    Yao, Lu; Zhou, Chao; Hu, Nantao; Hu, Jing; Hong, Min; Zhang, Liying; Zhang, Yafei

    2018-03-01

    Mechanically robust graphene papers with both high gravimetric and volumetric capacitances are desired for high-performance energy storages. However, it's still a challenge to tailor the structure of graphene papers in order to meet this requirement. In this work, a kind of chemical-reduction-tailored mechanically-robust reduced graphene oxide/carbon nanotube hybrid paper has been reported for high-performance electrochemical capacitive energy storages. Gallic acid (GA), as an excellent reducing agent, was used to reduce graphene oxide. Through vacuum filtration of gallic acid reduced graphene oxide (GA-rGO) and carboxylic multiwalled carbon nanotubes (MWCNTs) aqueous suspensions, mechanically robust GA-rGO/MWCNTs hybrid papers were obtained. The resultant hybrid papers showed high gravimetric capacitance of 337.6 F g-1 (0.5 A g-1) and volumetric capacitance of 151.2 F cm-3 (0.25 A cm-3). In addition, the assembled symmetric device based on the hybrid papers exhibited high gravimetric capacitance of 291.6 F g-1 (0.5 A g-1) and volumetric capacitance of 136.6 F cm-3 (0.25 A cm-3). Meanwhile, it exhibited excellent rate capability and cycling stability. Above all, this chemical reduction tailoring technique and the resultant high-performance GA-rGO/MWCNTs hybrid papers give an insight for designing high-performance electrodes and hold a great potential in the field of energy storages.

  14. Opportunities for cost reduction and improved environmental impact in the lead and lead/acid battery industries

    Science.gov (United States)

    Lewis, N.

    The opportunities for cost reduction through improved environmental performance exist in many companies, but often are not realized. This paper describes the efforts of a typical firm — Calder Industrial Materials (CIM) — that is experiencing ever-tighter environmental controls and profit erosion through the effects of new environmental legislation. At the same time, however, CIM sees opportunities to reduce its environmental burden and cut costs. As the story unfolds, readers may well discover many parallels with their own companies. It may even spur some into action, for remember, every £1000 saved requires ten times the turnover to generate the same profit.

  15. 2,3-Dihydroxybenzoic acid attenuates kanamycin-induced volume reduction in mouse utricular type I hair cells

    DEFF Research Database (Denmark)

    Severinsen, Stig Åvall; Kirkegaard, Mette; Nyengaard, Jens Randel

    2006-01-01

    injection. Total volume of the utricle, as well as total number of hair and supporting cells, were estimated on light microscopic sections. Total volume and mean volume of hair cell types I and II and supporting cells were estimated on digital transmission electron micrographs. Total volume of the utricular...... macula, hair cell type I and supporting cells decreased significantly in animals injected with kanamycin but not in animals co-treated with DHB. Hair and supporting cell numbers remained unchanged in all three groups. In conclusion, the kanamycin-induced volume reduction of type I hair cells...

  16. Enzymatically and reductively degradable α-amino acid-based poly(ester amide)s: synthesis, cell compatibility, and intracellular anticancer drug delivery.

    Science.gov (United States)

    Sun, Huanli; Cheng, Ru; Deng, Chao; Meng, Fenghua; Dias, Aylvin A; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

    2015-02-09

    A novel and versatile family of enzymatically and reductively degradable α-amino acid-based poly(ester amide)s (SS-PEAs) were developed from solution polycondensation of disulfide-containing di-p-toluenesulfonic acid salts of bis-l-phenylalanine diesters (SS-Phe-2TsOH) with di-p-nitrophenyl adipate (NA) in N,N-dimethylformamide (DMF). SS-PEAs with Mn ranging from 16.6 to 23.6 kg/mol were obtained, depending on NA/SS-Phe-2TsOH molar ratios. The chemical structures of SS-PEAs were confirmed by (1)H NMR and FTIR spectra. Thermal analyses showed that the obtained SS-PEAs were amorphous with a glass transition temperature (Tg) in the range of 35.2-39.5 °C. The in vitro degradation studies of SS-PEA films revealed that SS-PEAs underwent surface erosion in the presence of 0.1 mg/mL α-chymotrypsin and bulk degradation under a reductive environment containing 10 mM dithiothreitol (DTT). The preliminary cell culture studies displayed that SS-PEA films could well support adhesion and proliferation of L929 fibroblast cells, indicating that SS-PEAs have excellent cell compatibility. The nanoparticles prepared from SS-PEA with PVA as a surfactant had an average size of 167 nm in phosphate buffer (PB, 10 mM, pH 7.4). SS-PEA nanoparticles while stable under physiological environment undergo rapid disintegration under an enzymatic or reductive condition. The in vitro drug release studies showed that DOX release was accelerated in the presence of 0.1 mg/mL α-chymotrypsin or 10 mM DTT. Confocal microscopy observation displayed that SS-PEA nanoparticles effectively transported DOX into both drug-sensitive and -resistant MCF-7 cells. MTT assays revealed that DOX-loaded SS-PEA nanoparticles had a high antitumor activity approaching that of free DOX in drug-sensitive MCF-7 cells, while more than 10 times higher than free DOX in drug-resistant MCF-7/ADR cells. These enzymatically and reductively degradable α-amino acid-based poly(ester amide)s have provided an appealing platform for

  17. Bace1 activity impairs neuronal glucose metabolism: rescue by beta-hydroxybutyrate and lipoic acid

    Directory of Open Access Journals (Sweden)

    John A Findlay

    2015-10-01

    Full Text Available Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer’s disease (AD pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP cleaving enzyme 1 (BACE1, responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.

  18. Alternative substrates of bacterial sulphate reduction suitable for the biological-chemical treatment of acid mine drainage

    Directory of Open Access Journals (Sweden)

    Alena Luptakova

    2012-12-01

    Full Text Available The impacts of AMD pollution on biological systems are mostly severe and the problem may persist from many decadesto thousands of years. Consequently AMD prior to being released into the environment must be treated to meet government standardsfor the amount of metal and non-metal ions contained in the water. One of the best available technologies for the removal of metals fromAMD is precipitation as metal sulphides. SRB applications for AMD treatment involve a few principal stages. The first stageis the cultivation of SRB i.e. the bacterial sulphate reduction. At the laboratory conditions the sodium lactate is the energetic substratefor the growth of bacteria. Its price is not economic for the application in the practice and is needed investigate the alternativesubstitutes. The aim of this work was the cultivation of SRB using the selected energetic substrates such as: calcium lactate, ethanol,saccharose, glucose and whey. Experimental studies confirm that in the regard to the amount of reduced sulphates the calcium lactateand ethanol are the best alternative substrates for the bacterial sulphate-reduction.

  19. Green synthesis of gold and silver nanoparticles using gallic acid: catalytic activity and conversion yield toward the 4-nitrophenol reduction reaction

    Science.gov (United States)

    Park, Jisu; Cha, Song-Hyun; Cho, Seonho; Park, Youmie

    2016-06-01

    In the present report, gallic acid was used as both a reducing and stabilizing agent to synthesize gold and silver nanoparticles. The synthesized gold and silver nanoparticles exhibited characteristic surface plasmon resonance bands at 536 and 392 nm, respectively. Nanoparticles that were approximately spherical in shape were observed in high-resolution transmission electron microscopy and atomic force microscopy images. The hydrodynamic radius was determined to be 54.4 nm for gold nanoparticles and 33.7 nm for silver nanoparticles in aqueous medium. X-ray diffraction analyses confirmed that the synthesized nanoparticles possessed a face-centered cubic structure. FT-IR spectra demonstrated that the carboxylic acid functional groups of gallic acid contributed to the electrostatic binding onto the surface of the nanoparticles. Zeta potential values of -41.98 mV for the gold nanoparticles and -53.47 mV for the silver nanoparticles indicated that the synthesized nanoparticles possess excellent stability. On-the-shelf stability for 4 weeks also confirmed that the synthesized nanoparticles were quite stable without significant changes in their UV-visible spectra. The synthesized nanoparticles exhibited catalytic activity toward the reduction reaction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. The rate constant of the silver nanoparticles was higher than that of the gold nanoparticles in the catalytic reaction. Furthermore, the conversion yield (%) of 4-nitrophenol to 4-aminophenol was determined using reversed-phase high-performance liquid chromatography with UV detection at 254 nm. The silver nanoparticles exhibited an excellent conversion yield (96.7-99.9 %), suggesting that the synthesized silver nanoparticles are highly efficient catalysts for the 4-nitrophenol reduction reaction.

  20. Green synthesis of gold and silver nanoparticles using gallic acid: catalytic activity and conversion yield toward the 4-nitrophenol reduction reaction

    International Nuclear Information System (INIS)

    Park, Jisu; Cha, Song-Hyun; Cho, Seonho; Park, Youmie

    2016-01-01

    In the present report, gallic acid was used as both a reducing and stabilizing agent to synthesize gold and silver nanoparticles. The synthesized gold and silver nanoparticles exhibited characteristic surface plasmon resonance bands at 536 and 392 nm, respectively. Nanoparticles that were approximately spherical in shape were observed in high-resolution transmission electron microscopy and atomic force microscopy images. The hydrodynamic radius was determined to be 54.4 nm for gold nanoparticles and 33.7 nm for silver nanoparticles in aqueous medium. X-ray diffraction analyses confirmed that the synthesized nanoparticles possessed a face-centered cubic structure. FT-IR spectra demonstrated that the carboxylic acid functional groups of gallic acid contributed to the electrostatic binding onto the surface of the nanoparticles. Zeta potential values of −41.98 mV for the gold nanoparticles and −53.47 mV for the silver nanoparticles indicated that the synthesized nanoparticles possess excellent stability. On-the-shelf stability for 4 weeks also confirmed that the synthesized nanoparticles were quite stable without significant changes in their UV–visible spectra. The synthesized nanoparticles exhibited catalytic activity toward the reduction reaction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. The rate constant of the silver nanoparticles was higher than that of the gold nanoparticles in the catalytic reaction. Furthermore, the conversion yield (%) of 4-nitrophenol to 4-aminophenol was determined using reversed-phase high-performance liquid chromatography with UV detection at 254 nm. The silver nanoparticles exhibited an excellent conversion yield (96.7–99.9 %), suggesting that the synthesized silver nanoparticles are highly efficient catalysts for the 4-nitrophenol reduction reaction.

  1. A two-layer application of the MAGIC model to predict the effects of land use scenarios and reductions in deposition on acid sensitive soils in the UK

    Directory of Open Access Journals (Sweden)

    R. C. Helliwell

    1998-01-01

    Full Text Available A two-layer application of the catchment-based soil and surface water acidification model, MAGIC, was applied to 21 sites in the UK Acid Waters Monitoring Network (AWAMN, and the results were compared with those from a one-layer application of the model. The two-layer model represented typical soil properties more accurately by segregating the organic and mineral horizons into two separate soil compartments. Reductions in sulphur (S emissions associated with the Second S Protocol and different forestry (land use scenarios were modelled, and their effects on soil acidification evaluated. Soil acidification was assessed in terms of base saturation and critical loads for the molar ratio of base cations (CA2+ + MG 2+ + K+ to aluminium (Al in soil solution. The results of the two-layer application indicate that base saturation of the organic compartment was very responsive to changes in land use and deposition compared with the mineral soil. With the two- layer model, the organic soil compartment was particularly sensitive to acid deposition, which resulted in the critical load being predicted to be exceeded at eight sites in 1997 and two sites in 2010. These results indicate that further reductions in S deposition are necessary to raise the base cation (BC:Al ratio above the threshold which is harmful to tree roots. At forested sites BC:Al ratios were generally well below the threshold designated for soil critical loads in Europe and forecasts indicate that forest replanting can adversely affect the acid status of sensitive term objectives of protecting and sustaining soil and water quality. Policy formulation must seek to protect the most sensitive environmental receptor, in this case organic soils. It is clear, therefore, that simply securing protection of surface waters, via the critical loads approach, may not ensure adequate protection of low base status organic soils from the effects of acidification.

  2. Green synthesis of gold and silver nanoparticles using gallic acid: catalytic activity and conversion yield toward the 4-nitrophenol reduction reaction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jisu [Inje University, College of Pharmacy (Korea, Republic of); Cha, Song-Hyun; Cho, Seonho [Seoul National University, Department of Naval Architecture and Ocean Engineering (Korea, Republic of); Park, Youmie, E-mail: youmiep@inje.ac.kr [Inje University, College of Pharmacy (Korea, Republic of)

    2016-06-15

    In the present report, gallic acid was used as both a reducing and stabilizing agent to synthesize gold and silver nanoparticles. The synthesized gold and silver nanoparticles exhibited characteristic surface plasmon resonance bands at 536 and 392 nm, respectively. Nanoparticles that were approximately spherical in shape were observed in high-resolution transmission electron microscopy and atomic force microscopy images. The hydrodynamic radius was determined to be 54.4 nm for gold nanoparticles and 33.7 nm for silver nanoparticles in aqueous medium. X-ray diffraction analyses confirmed that the synthesized nanoparticles possessed a face-centered cubic structure. FT-IR spectra demonstrated that the carboxylic acid functional groups of gallic acid contributed to the electrostatic binding onto the surface of the nanoparticles. Zeta potential values of −41.98 mV for the gold nanoparticles and −53.47 mV for the silver nanoparticles indicated that the synthesized nanoparticles possess excellent stability. On-the-shelf stability for 4 weeks also confirmed that the synthesized nanoparticles were quite stable without significant changes in their UV–visible spectra. The synthesized nanoparticles exhibited catalytic activity toward the reduction reaction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. The rate constant of the silver nanoparticles was higher than that of the gold nanoparticles in the catalytic reaction. Furthermore, the conversion yield (%) of 4-nitrophenol to 4-aminophenol was determined using reversed-phase high-performance liquid chromatography with UV detection at 254 nm. The silver nanoparticles exhibited an excellent conversion yield (96.7–99.9 %), suggesting that the synthesized silver nanoparticles are highly efficient catalysts for the 4-nitrophenol reduction reaction.

  3. Study of disulfide reduction and alkyl chloroformate derivatization of plasma sulfur amino acids using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Svagera, Zdeněk; Hanzlíková, Dagmar; Simek, Petr; Hušek, Petr

    2012-03-01

    Four disulfide-reducing agents, dithiothreitol (DTT), 2,3-dimercaptopropanesulfonate (DMPS), and the newly tested 2-mercaptoethanesulfonate (MESNA) and Tris(hydroxypropyl)phosphine (THP), were investigated in detail for release of sulfur amino acids in human plasma. After protein precipitation with trichloroacetic acid (TCA), the plasma supernatant was treated with methyl, ethyl, or propyl chloroformate via the well-proven derivatization-extraction technique and the products were subjected to gas chromatographic-mass spectrometric (GC-MS) analysis. All the tested agents proved to be rapid and effective reducing agents for the assay of plasma thiols. When compared with DTT, the novel reducing agents DMPS, MESNA, and THP provided much cleaner extracts and improved analytical performance. Quantification of homocysteine, cysteine, and methionine was performed using their deuterated analogues, whereas other analytes were quantified by means of 4-chlorophenylalanine. Precise and reliable assay of all examined analytes was achieved, irrespective of the chloroformate reagent used. Average relative standard deviations at each analyte level were ≤6%, quantification limits were 0.1-0.2 μmol L(-1), recoveries were 94-121%, and linearity was over three orders of magnitude (r(2) equal to 0.997-0.998). Validation performed with the THP agent and propyl chloroformate derivatization demonstrated the robustness and reliability of this simple sample-preparation methodology.

  4. Mechanisms of Enzyme-Catalyzed Reduction of Two Carcinogenic Nitro-Aromatics, 3-Nitrobenzanthrone and Aristolochic Acid I: Experimental and Theoretical Approaches

    Directory of Open Access Journals (Sweden)

    Marie Stiborová

    2014-06-01

    Full Text Available This review summarizes the results found in studies investigating the enzymatic activation of two genotoxic nitro-aromatics, an environmental pollutant and carcinogen 3-nitrobenzanthrone (3-NBA and a natural plant nephrotoxin and carcinogen aristolochic acid I (AAI, to reactive species forming covalent DNA adducts. Experimental and theoretical approaches determined the reasons why human NAD(PH:quinone oxidoreductase (NQO1 and cytochromes P450 (CYP 1A1 and 1A2 have the potential to reductively activate both nitro-aromatics. The results also contributed to the elucidation of the molecular mechanisms of these reactions. The contribution of conjugation enzymes such as N,O-acetyltransferases (NATs and sulfotransferases (SULTs to the activation of 3-NBA and AAI was also examined. The results indicated differences in the abilities of 3-NBA and AAI metabolites to be further activated by these conjugation enzymes. The formation of DNA adducts generated by both carcinogens during their reductive activation by the NOQ1 and CYP1A1/2 enzymes was investigated with pure enzymes, enzymes present in subcellular cytosolic and microsomal fractions, selective inhibitors, and animal models (including knock-out and humanized animals. For the theoretical approaches, flexible in silico docking methods as well as ab initio calculations were employed. The results summarized in this review demonstrate that a combination of experimental and theoretical approaches is a useful tool to study the enzyme-mediated reaction mechanisms of 3-NBA and AAI reduction.

  5. Mechanisms of Enzyme-Catalyzed Reduction of Two Carcinogenic Nitro-Aromatics, 3-Nitrobenzanthrone and Aristolochic Acid I: Experimental and Theoretical Approaches

    Science.gov (United States)

    Stiborová, Marie; Frei, Eva; Schmeiser, Heinz H.; Arlt, Volker M.; Martínek, Václav

    2014-01-01

    This review summarizes the results found in studies investigating the enzymatic activation of two genotoxic nitro-aromatics, an environmental pollutant and carcinogen 3-nitrobenzanthrone (3-NBA) and a natural plant nephrotoxin and carcinogen aristolochic acid I (AAI), to reactive species forming covalent DNA adducts. Experimental and theoretical approaches determined the reasons why human NAD(P)H:quinone oxidoreductase (NQO1) and cytochromes P450 (CYP) 1A1 and 1A2 have the potential to reductively activate both nitro-aromatics. The results also contributed to the elucidation of the molecular mechanisms of these reactions. The contribution of conjugation enzymes such as N,O-acetyltransferases (NATs) and sulfotransferases (SULTs) to the activation of 3-NBA and AAI was also examined. The results indicated differences in the abilities of 3-NBA and AAI metabolites to be further activated by these conjugation enzymes. The formation of DNA adducts generated by both carcinogens during their reductive activation by the NOQ1 and CYP1A1/2 enzymes was investigated with pure enzymes, enzymes present in subcellular cytosolic and microsomal fractions, selective inhibitors, and animal models (including knock-out and humanized animals). For the theoretical approaches, flexible in silico docking methods as well as ab initio calculations were employed. The results summarized in this review demonstrate that a combination of experimental and theoretical approaches is a useful tool to study the enzyme-mediated reaction mechanisms of 3-NBA and AAI reduction. PMID:24918288

  6. Electrodeposited ultrafine NbOx, ZrOx, and TaO x nanoparticles on carbon black supports for oxygen reduction electrocatalysts in acidic media

    KAUST Repository

    Seo, Jeongsuk

    2013-09-06

    A remarkable electrocatalytic activity was obtained for the oxygen reduction reaction (ORR) in acidic solutions on ultrafine nano-oxide catalysts based on group IV or V elements. By potentiostatic electrodepostion in nonaqueous solutions at 298 K followed by heat treatment in H2 gas, highly dispersed fine nanoparticles of NbOx, ZrOx, and TaOx with sizes of less than 5 nm were prepared and deposited on carbon black (CB) loaded electrodes. These oxide nanoparticles showed high catalytic activities with high onset potentials of 0.96 VRHE (NbOx), 1.02 VRHE (ZrOx), and 0.93 V RHE (TaOx) for the ORR. Owing to the high chemical stability of group IV and V oxides, the catalysts were very stable during the ORR in acidic solutions. Surface characterization and chemical identification were performed using scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). All results clearly indicate the formation of nano-oxide electrocatalysts that show an outstanding ORR performance, whereas the bulk oxides are not active because of the absence of electronic conductivity. The present work demonstrates potential candidates for highly stable, non-noble-metal cathode catalysts for polymer electrolyte fuel cells (PEFCs), where the catalysts are exposed to highly acidic and oxidizing conditions. © 2013 American Chemical Society.

  7. Electrodeposited ultrafine NbOx, ZrOx, and TaO x nanoparticles on carbon black supports for oxygen reduction electrocatalysts in acidic media

    KAUST Repository

    Seo, Jeongsuk; Cha, Dong Kyu; Takanabe, Kazuhiro; Kubota, Jun; Domen, Kazunari

    2013-01-01

    A remarkable electrocatalytic activity was obtained for the oxygen reduction reaction (ORR) in acidic solutions on ultrafine nano-oxide catalysts based on group IV or V elements. By potentiostatic electrodepostion in nonaqueous solutions at 298 K followed by heat treatment in H2 gas, highly dispersed fine nanoparticles of NbOx, ZrOx, and TaOx with sizes of less than 5 nm were prepared and deposited on carbon black (CB) loaded electrodes. These oxide nanoparticles showed high catalytic activities with high onset potentials of 0.96 VRHE (NbOx), 1.02 VRHE (ZrOx), and 0.93 V RHE (TaOx) for the ORR. Owing to the high chemical stability of group IV and V oxides, the catalysts were very stable during the ORR in acidic solutions. Surface characterization and chemical identification were performed using scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). All results clearly indicate the formation of nano-oxide electrocatalysts that show an outstanding ORR performance, whereas the bulk oxides are not active because of the absence of electronic conductivity. The present work demonstrates potential candidates for highly stable, non-noble-metal cathode catalysts for polymer electrolyte fuel cells (PEFCs), where the catalysts are exposed to highly acidic and oxidizing conditions. © 2013 American Chemical Society.

  8. Performance and selectivity of PtxSn/C electro-catalysts for ethanol oxidation prepared by reduction with different formic acid concentrations

    International Nuclear Information System (INIS)

    Zignani, Sabrina C.; Baglio, Vincenzo; Linares, José J.; Monforte, Giuseppe; Gonzalez, Ernesto R.; Aricò, Antonino S.

    2012-01-01

    Carbon supported Pt–Sn catalysts were prepared by reduction of Pt and Sn precursors with formic acid and characterized in terms of structure, morphology and surface properties. The electrocatalytic activity for ethanol oxidation was studied in a direct ethanol fuel cell (DEFC) at 70 °C and 90 °C. Electrochemical and physico-chemical data indicated that a proper balance of Pt and Sn species in the near surface region was necessary to maximize the reaction rate. The best atomic surface composition, in terms of electrochemical performance, was Pt:Sn 65:35 corresponding to a bulk composition 75:25 namely Pt 3 Sn 1 /C. The reaction products of ethanol electro-oxidation in single cell and their distribution as a function of the nature of catalyst were determined. Essentially, acetaldehyde and acetic acid were detected as the main reaction products; whereas, a lower content of CO 2 was formed. The selectivity toward acetic acid vs. acetaldehyde increased with the increase of the Sn content and decreased by decreasing the concentration of the reducing agent used in the catalyst preparation. According to the recent literature, these results have been interpreted on the basis of ethanol adsorption characteristics and ligand effects occurring for Sn-rich electrocatalysts.

  9. Dietary protein reduction on microbial protein, amino acid digestibility, and body retention in beef cattle: 2. Amino acid intestinal absorption and their efficiency for whole-body deposition.

    Science.gov (United States)

    Mariz, L D S; Amaral, P M; Valadares Filho, S C; Santos, S A; Detmann, E; Marcondes, M I; Pereira, J M V; Silva Júnior, J M; Prados, L F; Faciola, A P

    2018-03-06

    The objective of this study was to determine the apparent and true intestinal digestibility of total and individual AA, and to estimate the efficiency of whole-body AA retention from individual and total absorbed AA. Four Nellore animals (241.3 kg initial BW) and four crossbred Angus × Nellore (263.4 kg initial BW) cannulated in rumen and ileum were randomly allocated in two 4 × 4 Latin squares. The experiment lasted four 17 d periods, with 10 d for adaptation to diets and another 7 d for data collection. The diets consisted of increasing CP levels: 100, 120, or 140 g/kg of DM offered ad libitum, and restricted intake diet with 120 g CP/kg DM (experiment 1). In experiment 2, forty-four bulls (22 Nellore and 22 crossbred F1 Angus × Nellore) with 8 months and initial shrunk BW 215.0 ± 15.0 kg (Nellore = 208.0 ± 12.78 kg; Angus × Nellore = 221.9 ± 14.16 kg) were used. Eight of those animals were slaughtered at the beginning of the experiment. The remaining 36 bulls were allocated in a completely randomized design with six replicates, in a 2 (genetic groups) × 3 (CP contents) factorial scheme. The amount of essential AA (EAA) and nonessential AA (NEAA) reaching the small intestine increased linearly (P digestibility of EAA was not affected (P > 0.05) by CP content, with exception for histidine (P = 0.07, linear effect), leucine (P = 0.01, linear effect), and methionine (P = 0.05, linear effect). Differences existed among AA when compared the apparent digestibility of NEAA. The apparent digestibility of alanine (P = 0.05), aspartic acid (P = 0.07), glutamic acid (P = 0.02), glycine (P = 0.05), proline (P = 0.02), and serine (P = 0.04) responded quadratically to CP content increase. However, the apparent digestibility of cystine and tyrosine was not affected (P > 0.05) by increasing dietary CP. The true intestinal digestibilities of total, essential, nonessential AA, lysine, and methionine were 75.0%, 77.0%, 74.0%, 77.0%, and 86%, respectively. The true

  10. Randomized trial of amino acid mixture combined with physical activity promotion for abdominal fat reduction in overweight adults.

    Science.gov (United States)

    Ueda, Keisuke; Sasai, Hiroyuki; Tsujimoto, Takehiko; Sanbongi, Chiaki; Ikegami, Shuji; Kobayashi, Hiroyuki; Shioya, Nobuhiko; Suzuki, Satoru; Nakata, Yoshio

    2018-01-01

    The purpose of this study was to test the efficacy of arginine, alanine, and phenylalanine mixture (A-mix) ingestion at 1,500 mg/day in combination with the promotion of physical activity for abdominal fat reduction in overweight adults. A placebo-controlled, double-blind, parallel-group, randomized trial for 12 weeks combined with a 4-week follow-up period was conducted at a single center in Minato-ku, Tokyo, Japan, between December 2016 and May 2017. Data were analyzed between June and August 2017. The study participants were 200 overweight adults within the age range of 20-64 years. The participants were randomly assigned to the A-mix group (n=100) or a placebo group (n=100) and were administered 500 mL of test beverage containing 1,500 or 0 mg of A-mix, respectively, for 12 weeks. All participants maintained a physically active lifestyle between week 0 and week 12 through monthly sessions of physical activity. The primary outcomes were the 12-week changes in the abdominal total, subcutaneous, and visceral fat areas, as assessed by computed tomography. Of the 200 enrolled participants, 199 (99%) accomplished the 12-week intervention and 4-week follow-up period. The per-protocol-based analysis for 194 participants demonstrated that the abdominal total fat area decreased significantly in the A-mix group compared with that in the placebo group (difference, 10.0 cm 2 ; 95% confidence interval [CI]: 0.4-19.6 cm 2 ; P =0.041). Comparable outcomes were obtained for the abdominal subcutaneous fat area (difference, 7.4 cm 2 ; 95% CI: 0.1-14.7 cm 2 ; P =0.047). No study-related unfavorable events occurred. A-mix supplementation in combination with physical activity promotion facilitated abdominal fat reduction in overweight adults.

  11. Reduction of unwanted submental fat with ATX-101 (deoxycholic acid), an adipocytolytic injectable treatment: results from a phase III, randomized, placebo-controlled study*

    Science.gov (United States)

    Rzany, B; Griffiths, T; Walker, P; Lippert, S; McDiarmid, J; Havlickova, B

    2014-01-01

    Summary Background Unwanted submental fat (SMF) is aesthetically unappealing, but methods of reduction are either invasive or lack evidence for their use. An injectable approach with ATX-101 (deoxycholic acid) is under investigation. Objectives To evaluate the efficacy and safety of ATX-101 for the reduction of unwanted SMF. Methods In this double-blind, placebo-controlled, phase III study, 363 patients with moderate/severe SMF were randomized to receive ATX-101 (1 or 2 mg cm−2) or placebo injections into their SMF at up to four treatment sessions ∽28 days apart, with a 12-week follow-up. The co-primary efficacy endpoints were the proportions of treatment responders [patients with ≥ 1-point improvement in SMF on the 5-point Clinician-Reported Submental Fat Rating Scale (CR-SMFRS)] and patients satisfied with their face and chin appearance on the Subject Self-Rating Scale (SSRS). Secondary endpoints included skin laxity, calliper measurements and patient-reported outcomes. Adverse events were monitored. Results Significantly more ATX-101 recipients met the primary endpoint criteria vs. placebo: on the clinician scale, 59·2% and 65·3% of patients treated with ATX-101 1 and 2 mg cm−2, respectively, were treatment responders vs. 23·0% for placebo (CR-SMFRS;P < 0·001); on the patient scale, 53·3% and 66·1%, respectively, vs. 28·7%, were satisfied with their face/chin appearance (SSRS;P < 0·001). Calliper measurements showed a significant reduction in SMF (P < 0·001), skin laxity was not worsened and patients reported improvements in the severity and psychological impact of SMF with ATX-101 vs. placebo. Most adverse events were transient and associated with the treatment area. Conclusions ATX-101 was effective and well tolerated for nonsurgical SMF reduction. What's already known about this topic? Unwanted submental fat (SMF) is considered aesthetically unappealing. Liposuction and face-lift are effective treatments for SMF reduction but are

  12. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids.

    Science.gov (United States)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P; Gurinov, Andrey; Ortiz, Genaro Gabriel; Carbajal Arízaga, Gregorio Guadalupe

    2015-03-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Impact of visual inspection with acetic acid plus cryotherapy "see and treat" approach on the reduction of the population burden of cervical preinvasive lesions in Southeast Nigeria.

    Science.gov (United States)

    Chigbu, C O; Onyebuchi, A K; Nnakenyi, E F; Egbuji, C C

    2017-02-01

    The aim of this study is to determine the impact of visual inspection with acetic acid (VIA) plus immediate cryotherapy on the prevalence of VIA-detected cervical squamous intraepithelial lesion (SIL). Women in four rural communities in Southeast Nigeria were screened with VIA. Women who tested positive to VIA were offered either immediate cryotherapy or large loop excision of the transformation zone based on predetermined eligibility criteria. Cervical biopsies were taken before cryotherapy and examined by consultant histopathologists. All participants were rescreened 1 year later. The main outcome measures were population prevalence of cervical precancers before and after intervention, cure rates, and over-treatment rates. A total of 653 women participated in the study. The prevalence of cervical SIL before the intervention was 8.9% (58/653). The prevalence 1 year later was 1.4% (9/649). This gave an 84.3% reduction in the population prevalence of SIL. The reduction in cervical SIL prevalence was statistically significant (P = 0.0001). The prevalence of high-grade SIL reduced significantly from 4.1% (27/653) preintervention to 0.5% (3/649) 1 year postintervention (P = 0.0001). This gave an 87.8% reduction in the population prevalence of high-grade SIL. Cryotherapy provided a cure rate of 87.9% (95% confidence interval: 76.82-94.33). Population cervical cancer prevention using VIA plus immediate cryotherapy leads to significant reduction in the population prevalence of cervical SIL. This has the potential of being an acceptable supplement to cervical cytology for cervical cancer prevention in low-income populations.

  14. Syntheses, structures, molecular and cationic recognitions and catalytic properties of two lanthanide coordination polymers based on a flexible tricarboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yu; Wang, Yan-Mei; Xu, Ji; Liu, Pan; Weththasinha, H.A.B.M.D.; Wu, Yun-Long; Lu, Xiao-Qing; Xie, Ji-Min, E-mail: xiejm391@sohu.com

    2014-11-15

    Two lanthanide coordination polymers, namely, ([La(TTTA)(H{sub 2}O){sub 2}]·2H{sub 2}O){sub n} (La-TTTA) and [Nd(TTTA)(H{sub 2}O){sub 2}]·2H{sub 2}O){sub n} (Nd-TTTA) have been hydrothermally synthesized through the reaction of lanthanide ions (La{sup 3+} and Nd{sup 3+}) with the flexible tripodal ligand 2,2′,2″-[1,3,5-triazine-2,4,6-triyltris(thio)]tris-acetic acid (H{sub 3}TTTA). La-TTTA and Nd-TTTA are isostructural and both show three dimensional structures. La-TTTA and Nd-TTTA show good recognition of amine molecules via quenching the luminescent intensities in amines emulsions. They can also recognize Fe{sup 3+}, Cu{sup 2+}, Mg{sup 2+}, Cr{sup 3+} and Co{sup 2+} ions with the quenching the peak around 361 nm when the compounds immersed in ionic solutions. The two compounds act as efficient Lewis acid catalysts for the cyanosilylation of benzaldehyde and derivatives in high yields shortly due to the strong Lewis acidity and the possible open sites of the lanthanide ions. - Graphical abstract: We have synthesized two isostructural 3D compounds based on H{sub 3}TTTA. They are chemical sensor of amine solvents and cations. They have higher yields and TOFs to catalyze cyanosilylation reactions. - Highlights: • The compounds show recognition of amine molecules via quenching luminescent intensities. • The compounds recognize Fe{sup 3+}, Cu{sup 2+}, Mg{sup 2+}, Cr{sup 3+} and Co{sup 2+} ions via quenching the peak around 361 nm. • They act as efficient Lewis acid catalysts for the cyanosilylation reactions in high yields.

  15. Synthesis of Fulvic Acid-Coated Magnetite (Fe3O4–FA and Its Application for the Reductive Adsorption of [AuCl4]–

    Directory of Open Access Journals (Sweden)

    Philip Anggo Krisbiantoro

    2017-11-01

    Full Text Available Fulvic acid-coated magnetite (Fe3O4–FA has been synthesized through coprecipitation method using NH4OH. Synthesis conducted by cheap and environmentally friendly preparation used iron salts and extracted fulvic acid (FA from Peat soil of Rawa Pening, Central Java, Indonesia. Characterization using FT–IR indicated that the coating of FA on Fe3O4 occurred through the formation of chemical bond between iron of Fe3O4 and carboxyl group of FA. The XRD measurement indicated that coated Fe3O4 successfully dispersed in smaller size than uncoated Fe3O4, i.e. from 16.67 to 14.84 nm for Fe3O4 and Fe3O4–FA, respectively. Synthesized Fe3O4–FA has pHPZC 6.37 and stable at pH > 3.0. The extracted FA has total acidity 866.61 cmol kg–1, –COOH content 229.77 cmol kg–1 and –OH content 636.84 cmol kg–1. Fe3O4–FA has total acidity 494.86 cmol kg–1, –COOH content 67.80 cmol kg–1 and –OH content 427.06 cmol kg–1. The adsorption rate constant (k of [AuCl4]– on Fe3O4–A according to the Ho kinetic model was 8006.53 g mol–1 min–1. The adsorption capacity (qmax according to Langmuir isotherm model was 1.24 × 10–4 mol g–1. The presence of reduction towards the adsorbed [AuCl4]– was shown by the appearance of peaks at 2θ: 37.41; 43.66; 64.25, and 76.67° in the XRD diffractogram.

  16. Nitrogen and sulfur co-doped porous carbon – is an efficient electrocatalyst as platinum or a hoax for oxygen reduction reaction in acidic environment PEM fuel cell?

    International Nuclear Information System (INIS)

    Sahoo, Madhumita; Ramaprabhu, S.

    2017-01-01

    Non-precious, heteroatom doped carbon is reported to replace commercial Pt/C in both alkaline and acidic half-cell rotating disc electrode study; however the real world full cell measurements with the metal-free electrocatalysts overcoming the practical troubles in acidic environment proton exchange membrane fuel cell (PEMFC) are almost negligible to confirm the claim. Nitrogen and sulfur co-doped porous carbon (DPC) was synthesized in a one step, high yield process from single source ionic liquid precursor using eutectic salt as porogens to achieve porosity. Structural characterization confirms 7.03% nitrogen and 1.68% sulfur doping into the high surface area, porous carbon structure. As the cathode oxygen reduction reaction (ORR) catalyst, metal-free DPC and Pt nanoparticles decorated DPC (Pt/DPC) shows stable and high exchange current density by four electron transfer pathway in acidic half–cell liquid environment due to the synergistic effect of nitrogen and sulfur doping and porous nature of DPC. In an actual solid state full cell measurement, Pt/DPC shows higher performance comparable to commercial Pt/C; however DPC failed to reciprocate the half-cell performance due to blockage of active sites in the membrane electrode assembly fabrication process. - Highlights: • Synthesis of N and S co-doped porous carbon (DPC) in simple one-pot technique. • High surface area DPC shows comparable activity for ORR in half-cell acidic PEMFC study. • Real-world performance of DPC gives 20 mW/cm 2 peak power density at 60 °C. • Homogeneous Pt nanoparticles decorated DPC (Pt/DPC) outperforms commercial Pt/C. • Pt/DPC shows maximum power density of 718 mW/cm 2 with lower 0.3 mg/cm 2 total Pt loading.

  17. Electrooxidations of ethanol, acetaldehyde and acetic acid using PtRuSn/C catalysts prepared by modified alcohol-reduction process

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Gang [Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Swaidan, Raja [Department of Chemical Engineering, Cooper Union, New York, NY 10003 (United States); Cui, Guofeng [School of Chemistry and Chemical Engineering, Sun-Yat Sen University, Guangzhou 510275 (China)

    2007-10-11

    Well-dispersed ternary PtRuSn catalysts of various atomic ratios (60:30:10, 60:20:20 and 60:10:30) were deposited onto carbon using modified alcohol-reduction process for electrochemical oxidation of ethanol. The alloy phase structure and surface morphology for each variation of the PtRuSn/C catalysts were determined by XRD and HRTEM. In order to evaluate the contributions of Ru and Sn in the different stages of ethanol oxidation, electrochemical oxidations of adsorbed CO, ethanol, acetaldehyde and acetic acid were performed on each PtRuSn/C catalyst. The results indicated that the Ru-rich PtRuSn/C catalyst (60:30:10) exhibited the lowest onset potential for the electrooxidations of adsorbed CO, ethanol and acetaldehyde, revealing that the removal through oxidation of the intermediate C{sub 1} and C{sub 2} species from Pt sites is primarily attributed to the Ru and Pt{sub 3}Sn alloy structures. However, for the overall oxidation of ethanol, the Sn-rich PtRuSn/C catalyst (60:10:30) containing PtSn phase and SnO{sub 2} structure is favorable for the activation of C-C bond breaking, thereby generating higher current density (mass activity) at higher potentials. Moreover, in the electrooxidation of acetic acid, a remarkable improvement for oxidizing acetic acid to C{sub 1} species was observed in the Sn-rich PtRuSn/C catalyst (60:10:30), while the Ru-rich PtRuSn/C catalyst (60:30:10) was almost incapable of breaking the C-C bond to further oxidize acetic acid. The possible reasons for the different reactivities on the studied PtRuSn/C catalysts were discussed based on the removal of intermediates and activation of the C-C bonds on the different surfaces. (author)

  18. Infectivity reduction efficacy of UV irradiation and peracetic acid-UV combined treatment on MS2 bacteriophage and murine norovirus in secondary wastewater effluent.

    Science.gov (United States)

    Weng, ShihChi; Dunkin, Nathan; Schwab, Kellogg J; McQuarrie, James; Bell, Kati; Jacangelo, Joseph G

    2018-09-01

    Peracetic acid (PAA) is a strong oxidant/bactericide that has been applied in various industries (e.g., food processing, pharmaceuticals, medical device sterilization, etc.) as a disinfectant. There is increasing interest in using PAA for wastewater disinfection because it does not form halogenated byproducts, and no post-treatment quenching is required. Previous studies have demonstrated good efficiency in controlling bacteria in wastewater, but limited information is available for viruses, especially those hosted by mammals (e.g., norovirus). Therefore, a study on the infectivity reduction of murine norovirus (MNV) was undertaken to evaluate the disinfection efficacy of PAA or UV alone and in combination with UV irradiation in undisinfected secondary effluent from a municipal wastewater reclamation facility (MWW) and phosphate buffer solution (PBS) at pH 7. Experiments employing MS2 bacteriophage were also performed in parallel for comparison purposes. MS2 infectivity reduction was found to be lower than MNV infectivity reduction for each condition studied - PAA, PAA + UV, and UV disinfection. These data suggest that MS2 may not be an appropriate surrogate to accurately predict the reduction of MNV infectivity. UV irradiation, in a dose range of 5-250 mJ/cm 2 , provided linear log inactivation (-log (N/N 0 )) with a regression slope (cm 2 mJ -1 ) of 0.031-0.034 and 0.165-0.202 for MS2 and MNV, respectively. UV irradiation provided similar inactivation for MS2 and MNV in both suspensions (PBS or MWW). Low infectivity reduction of MS2 was observed when PAA was used alone at a practical dose of 1.5 mg/L and below. A greater reduction of both MNV and MS2 was observed in PAA disinfection experiments using PBS as the microbial suspension medium, than in secondary effluent. Similar results were observed in PAA + UV experiments, in which greater synergistic effects were found in PBS than in MWW. Results of OH radical formation experiments suggest the presence of

  19. Utilization of subsurface microbial electrochemical systems to elucidate the mechanisms of competition between methanogenesis and microbial iron(III)/humic acid reduction in Arctic peat soils

    Science.gov (United States)

    Friedman, E. S.; Miller, K.; Lipson, D.; Angenent, L. T.

    2012-12-01

    High-latitude peat soils are a major carbon reservoir, and there is growing concern that previously dormant carbon from this reservoir could be released to the atmosphere as a result of continued climate change. Microbial processes, such as methanogenesis and carbon dioxide production via iron(III) or humic acid reduction, are at the heart of the carbon cycle in Arctic peat soils [1]. A deeper understanding of the factors governing microbial dominance in these soils is crucial for predicting the effects of continued climate change. In previous years, we have demonstrated the viability of a potentiostatically-controlled subsurface microbial electrochemical system-based biosensor that measures microbial respiration via exocellular electron transfer [2]. This system utilizes a graphite working electrode poised at 0.1 V NHE to mimic ferric iron and humic acid compounds. Microbes that would normally utilize these compounds as electron acceptors donate electrons to the electrode instead. The resulting current is a measure of microbial respiration with the electrode and is recorded with respect to time. Here, we examine the mechanistic relationship between methanogenesis and iron(III)- or humic acid-reduction by using these same microbial-three electrode systems to provide an inexhaustible source of alternate electron acceptor to microbes in these soils. Chamber-based carbon dioxide and methane fluxes were measured from soil collars with and without microbial three-electrode systems over a period of four weeks. In addition, in some collars we simulated increased fermentation by applying acetate treatments to understand possible effects of continued climate change on microbial processes in these carbon-rich soils. The results from this work aim to increase our fundamental understanding of competition between electron acceptors, and will provide valuable data for climate modeling scenarios. 1. Lipson, D.A., et al., Reduction of iron (III) and humic substances plays a major

  20. Reduction of the degradation activity of umami-enhancing purinic ribonucleotide supplement in miso by the targeted suppression of acid phosphatases in the Aspergillus oryzae starter culture.

    Science.gov (United States)

    Marui, Junichiro; Tada, Sawaki; Fukuoka, Mari; Wagu, Yutaka; Shiraishi, Yohei; Kitamoto, Noriyuki; Sugimoto, Tatsuya; Hattori, Ryota; Suzuki, Satoshi; Kusumoto, Ken-Ichi

    2013-09-02

    Miso (fermented soybean paste) is a traditional Japanese fermented food, and is now used worldwide. The solid-state culture of filamentous fungus, Aspergillus oryzae, grown on rice is known as rice-koji, and is important as a starter for miso fermentation because of its prominent hydrolytic enzyme activities. Recently, commercial miso products have been supplemented with purinic ribonucleotides, such as inosine monophosphate (IMP) and guanine monophosphate, to enhance the characteristic umami taste of glutamate in miso. Because the purinic ribonucleotides are degraded by enzymes such as acid phosphatases in miso, heat inactivation is required prior to the addition of these flavorings. However, heat treatment is a costly process and reduces the quality of miso. Therefore, an approach to lower acid phosphatase activities in koji culture is necessary. Transcriptional analysis using an A. oryzae KBN8048 rice-koji culture showed that eight of the 13 acid phosphatase (aph) genes were significantly down-regulated by the addition of phosphoric acid in the preparation of the culture in a concentration-dependent manner, while aphC expression was markedly up-regulated under the same conditions. The eight down-regulated genes might be under the control of the functional counterpart of the Saccharomyces cerevisiae transcriptional activator Pho4, which specifically regulates phosphatase genes in response to the ambient phosphate availability. However, the regulatory mechanism of aphC was not clear. The IMP dephosphorylation activities in rice-koji cultures of KBN8048 and the aphC deletion mutant (ΔaphC) were reduced by up to 30% and 70%, respectively, in cultures with phosphoric acid, while protease and amylase activity, which is important for miso fermentation, was minimally affected. The miso products fermented using the rice-koji cultures of KBN8048 and ΔaphC prepared with phosphoric acid had reductions in IMP dephosphorylation activity of 80% and 90%, respectively, without

  1. Separation and determination of some carboxylic acids by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Sladkov, V.; Fourest, B

    2006-07-01

    Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

  2. Separation and determination of some carboxylic acids by capillary electrophoresis

    International Nuclear Information System (INIS)

    Sladkov, V.; Fourest, B.

    2006-01-01

    Separation and determination of some organic acids, mono-carboxylic (formic and acetic), dicarboxylic (oxalic and tartaric), tricarboxylic (citric) acids and aromatic acids (phtalic, benzoic, mellitic and trimellitic), by capillary electrophoresis are reviewed. The method development parameters, such as separation and injection mode, are discussed. Special attention is paid to the comparison of different detection types (spectroscopic and electrochemical). The optimisation of the carrier electrolyte composition (choice of carrier electrolyte, effect of pH, ionic strength, electro-osmotic flow modifier) is treated. Different additives (alkali-earth and transition metal ions, cyclodextrins and alcohol), which are often used for improving organic acid separation, are also considered. (authors)

  3. Topical versus intravenous tranexamic acid as a blood conservation intervention for reduction of post-operative bleeding in hemiarthroplasty.

    Science.gov (United States)

    Emara, Walid Mohamed; Moez, Khaled K; Elkhouly, Abeer H

    2014-01-01

    This study was performed to test the effectiveness of topical tranexamic acid (TXA) in reducing blood loss in pelvic hemiarthoplasty surgeries compared with intravenous TXA, regarding the incidence of thromboembolic complications (deep vein thrombosis [DVT], pulmonary embolism (PE) and cerebrovascular stroke [CVS]). After obtaining institutional ethical approval 60 patients divided into three groups. Group A: Received intravenous TXA Group B: Received topical TXA Group C: Control group (placebo saline). All patients were received general anesthesia and post-operative bleeding, immediate and 24 h post-operatively, hemoglobin concentration, hematocrit, platelets and coagulation profile (prothrombin time, activated partial thromboplastin time and international normalized ratio) baseline, immediate and 24 h post-operatively. Thromboelastography was recorded baseline, immediate and 24 h post-operatively. Incidence of DVT, PE and CVS was recorded. There was statistical significant elevation hemoglobin concentration and hematocrit in both Groups A and B, significant increase in blood loss in Group C, significant increase in number of patients receiving blood in Group C, there was a significant decrease in "r" and "k" times and a significant increase in maximum amplitude and α-angle in Group A, statistically significant increase in the incidence of thromboembolic events in the form of DVT, PE and CVS in Group A. Topical TXA is effective in decreasing post-operative blood loss with possible side-effects of this route of administration.

  4. Quantifying solubility enhancement due to particle size reduction and crystal habit modification: case study of acetyl salicylic acid.

    Science.gov (United States)

    Hammond, Robert B; Pencheva, Klimentina; Roberts, Kevin J; Auffret, Tony

    2007-08-01

    The poor solubility of potential drug molecules is a significant problem in the design of pharmaceutical formulations. It is well known, however, that the solubility of crystalline materials is enhanced when the particle size is reduced to submicron levels and this factor can be expected to enhance drug product bioavailability. Direct estimation of solubility enhancement, as calculated via the Gibbs-Thompson relationship, demands reasonably accurate values for the particle/solution interfacial tension and, in particular, its anisotropy with respect to the crystal product's habit and morphology. In this article, an improved, more molecule-centered, approach is presented towards the calculation of solubility enhancement factors in which molecular modeling techniques are applied, and the effects associated with both crystal habit modification and solvent choice are examined. A case study for facetted, acetyl salicylic acid (aspirin) crystals in equilibrium with saturated aqueous ethanol solution reveals that their solubility will be enhanced in the range (7-58%) for a crystal size of 0.02 microm, with significantly higher enhancement for crystal morphologies in which the hydrophobic crystal faces are more predominant than the hydrophilic faces and for solvents in which the solubility is smaller. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

  5. Reduction of Pulmonary Air Leaks with a Combination of Polyglycolic Acid Sheet and Alginate Gel in Rats

    Directory of Open Access Journals (Sweden)

    Mari Matoba

    2018-01-01

    Full Text Available Postoperative air leaks remain a major cause of morbidity after lung resection. This study evaluated the effect of a combination of polyglycolic acid (PGA sheet and alginate gel on pulmonary air leaks in rats. Four pulmonary sealing materials were evaluated in lung injury: fibrin glue, combination of PGA sheet and fibrin glue, alginate gel, and combination of PGA sheet and alginate gel. With the airway pressure maintained at 20 cmH2O, a 2 mm deep puncture wound was created on the lung surface using a needle. Lowering the airway pressure to 5 cmH2O, each sealing material was applied. The lowest airway pressure that broke the seal was measured. The seal-breaking pressure in each experimental group was fibrin, 10.4±6.8 cmH2O; PGA + fibrin, 13.5±6.5 cmH2O; alginate gel, 10.3±4.9 cmH2O; and PGA + alginate, 35.8±11.9 cmH2O, respectively. The seal-breaking pressure was significantly greater in the PGA + alginate gel group than in the other groups (p<0.01. There were no significant differences among the other three groups. Alginate gel combined with a PGA sheet is a promising alternative to fibrin glue as a safe and low-cost material for air leak prevention in pulmonary surgery.

  6. Uric acid-derived Fe3C-containing mesoporous Fe/N/C composite with high activity for oxygen reduction reaction in alkaline medium

    Science.gov (United States)

    Ma, Jun; Xiao, Dejian; Chen, Chang Li; Luo, Qiaomei; Yu, Yue; Zhou, Junhao; Guo, Changding; Li, Kai; Ma, Jie; Zheng, Lirong; Zuo, Xia

    2018-02-01

    In this work, a category of Fe3C-containing Fe/N/C mesoporous material has been fabricated by carbonizing the mixture of uric acid, Iron (Ⅲ) chloride anhydrous and carbon support (XC-72) under different pyrolysis temperature. Of all these samples, pyrolysis temperature (800 °C) becomes the most crucial factor in forming Fe3C active sites which synergizes with high content of graphitic N to catalyze oxygen reduction reaction (ORR). X-ray absorption fine structure spectroscopy (XAFS) is used to exhibit that the space structure around Fe atoms in the catalyst. This kind of catalyst possesses comparable ORR properties with commercial 20% Pt/C (onset potential is 0 V vs. Ag/AgCl in 0.1 M KOH), the average transfer electron number is 3.84 reflecting the 4-electron process. Moreover, superior stability and methanol tolerance deserve to be mentioned.

  7. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    International Nuclear Information System (INIS)

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-01-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  8. Ursodeoxycholic acid counteracts celecoxib in reduction of duodenal polyps in patients with familial adenomatous polyposis: a multicentre, randomized controlled trial

    Science.gov (United States)

    2013-01-01

    Background Due to prophylactic colectomy, mortality in patients with familial adenomatous polyposis (FAP) has changed, with duodenal cancer currently being the main cause of death. Although celecoxib reduces duodenal polyp density in patients with FAP, its long-term use may increase the risk of cardiovascular events and alternatives need to be explored. Preclinical studies suggest that the combination of celecoxib with ursodeoxycholic acid (UDCA) is a potentially effective strategy. We performed a randomized, double-blind, placebo-controlled trial to investigate the effect of celecoxib and UDCA co-treatment on duodenal adenomatosis in patients with FAP. Methods Patients with FAP received celecoxib (400 mg twice daily) and UDCA (1000-2000 mg daily, ~20-30 mg/kg/day, n=19) or celecoxib and placebo (n=18) orally for 6 months. Primary outcome was drug efficacy, assessed by comparing duodenal polyp density at pre- and post-intervention by blinded review of endoscopic recordings. As secondary outcomes, cell proliferation, apoptosis, and COX-2 levels in normal duodenal mucosa were assessed by immunohistochemistry or real-time quantitative polymerase chain reaction. Results In intention-to-treat analysis, deceased polyp density was observed after celecoxib/placebo treatment (p=0.029), whereas increased polyp density was observed after celecoxib/UDCA treatment (p=0.014). The difference in change in duodenal polyp density was statistically significant between the groups (p=0.011). No changes in secondary outcomes were observed. Thirty patients (81%) reported one or more adverse events, 16 patients (84%, Common Toxicity Criteria for Adverse Events version 3.0 (CTCAE) grade 1–3) treated with celecoxib/UDCA and 14 patients (78%, CTCAE grade 1–2) treated with celecoxib/placebo. Nine patients (24%) discontinued intervention prematurely, 5 patients (26%) treated with celecoxib/UDCA and 4 patients (22%) treated with celecoxib/placebo. Conclusions Celecoxib reduces duodenal

  9. Intensive lifestyle intervention provides rapid reduction of serum fatty acid levels in women with severe obesity without lowering omega-3 to unhealthy levels.

    Science.gov (United States)

    Lin, C; Andersen, J R; Våge, V; Rajalahti, T; Mjøs, S A; Kvalheim, O M

    2016-08-01

    Serum fatty acid (FA) levels were monitored in women with severe obesity during intensive lifestyle intervention. At baseline, total FA levels and most individual FAs were elevated compared to a matching cohort of normal and overweight women (healthy controls). After 3 weeks of intensive lifestyle intervention, total level was only 11-12% higher than in the healthy controls and with almost all FAs being significantly lower than at baseline, but with levels of omega-3 being similar to the healthy controls. This is contrary to observations for patients subjected to bariatric surgery where omega-3 levels dropped to levels significantly lower than in the lifestyle patients and healthy controls. During the next 3 weeks of treatment, the FA levels in lifestyle patients were unchanged, while the weight loss continued at almost the same rate as in the first 3 weeks. Multivariate analysis revealed that weight loss and change of serum FA patterns were unrelated outcomes of the intervention for lifestyle patients. For bariatric patients, these processes were associated probably due to reduced dietary input and increased input from the patients' own fat deposits, causing a higher rate of weight loss and simultaneous reduction of the ratio of serum eicosapentaenoic to arachidonic acid. © 2016 World Obesity.

  10. Determination of carbon-reduction-cycle intermediates in leaves of Arbutus unedo L. suffering depressions in photosynthesis after application of abscisic acid or exposure to dry air.

    Science.gov (United States)

    Loske, D; Raschke, K

    1988-02-01

    Gas exchange and contents of photosynthetic intermediates of leaves of Arbutus unedo L. were determined with the aim of recognizing the mechanisms of inhibition that were responsible for the "midday depression" of photosynthesis following exposure to dry air, and the decline in photosynthetic capacity following application of abscisic acid (ABA). Rapidly killed (<0.1 s) leaf samples were taken when gas analysis showed reduced CO2 assimilation. Determination of the contents of 3-phosphoglyceric acid (PGA), ribulose 1,5-bisphosphate (RuBP), triose phosphates, fructose 1,6-bisphosphate and hexose phosphates in the samples showed that significant variation occurred only in the level of PGA. As a result, the ratio PGA/RuBP decreased with increasing inhibition of photosynthesis, particularly when application of ABA had been the cause. A comparison of metabolite patterns did not bring out qualitative differences that would have indicated that effects of ABA and of dry air had been caused by separate mechanisms. Depression of photosynthesis occurred in the presence of sufficient RuBP which indicated that the carboxylation reaction of the carbon-reduction-cycle was inhibited after application of ABA or exposure to dry air.

  11. Dechlorination of Trichloroacetic Acid Using a Noble Metal-Free Graphene-Cu Foam Electrode via Direct Cathodic Reduction and Atomic H.

    Science.gov (United States)

    Mao, Ran; Li, Ning; Lan, Huachun; Zhao, Xu; Liu, Huijuan; Qu, Jiuhui; Sun, Meng

    2016-04-05

    A three-dimensional graphene-copper (3D GR-Cu) foam electrode prepared by chemical vapor deposition method exhibited superior electrocatalytic activity toward the dechlorination of trichloroacetic acid (TCAA) as compared to the Cu foam electrode. The cyclic voltammetry and electrochemical impedance spectra analysis confirmed that GR accelerated the electron transfer from the cathode surface to TCAA. With the applied cathode potential of -1.2 V (vs SCE), 95.3% of TCAA (500 μg/L) was removed within 20 min at pH 6.8. TCAA dechlorination at the Cu foam electrode was enhanced at acidic pH, while a slight pH effect was observed at the GR-Cu foam electrode with a significant inhibition for Cu leaching. The electrocatalytic dechlorination of TCAA was accomplished via a combined stepwise and concerted pathway on both electrodes, whereas the concerted pathway was efficiently promoted on the GR-Cu foam electrode. The direct reduction by electrons was responsible for TCAA dechlorination at Cu foam electrode, while at GR-Cu foam electrode, the surface-adsorbed atomic H* also contributed to TCAA dechlorination owing to the chemical storage of hydrogen in the GR structure. Finally, the potential applicability of GR-Cu foam was revealed by its stability in the electrocatalytic dechlorination over 25 cycles.

  12. Solvothermal modification of BiOCl nanosheets with Bi nanoparticles using ascorbic acid as reductant and the superoxide radicals dominated photocatalytic performance

    Science.gov (United States)

    Cui, Zhankui; Gao, Keke; Ge, Suxiang; Fa, Wenjun

    2017-11-01

    BiOCl nanosheets were solvothermally modified with Bi nanoparticles (NPs) using ascorbic acid as the reductant. The structures of Bi/BiOCl composites were characterized by XRD, Raman spectroscopy, FTIR spectroscopy and SEM. The light absorption properties were measured by UV-vis-NIR spectroscopy. The photocatalytic performances were evaluated by photodegrading methyl orange (MO) and the photocatalytic mechanism was investigated using trapping experiments and a fluorescent probe method. The results show that Bi NPs are uniformly distributed on the surfaces of BiOCl nanosheets and the modification amount of Bi NPs could be well controlled because of the mild property of ascorbic acid as reducing agent. The photocatalytic activities for the composites are improved obviously and the best photocatalytic performance is obtained when the weight ratio of Bi and BiOCl is1:10 and the photochemical reaction rate is 3.5 times that of pure BiOCl nanosheets and 19.7 times of Bi powders. The enhanced photocatalytic efficiency is ascribed to the favorable formation of dominant \\cdot O2- radicals caused by the increased photoinduced electrons from both Bi NPs and BiOCl nanosheets.

  13. Scanning electrochemical microscopy. 47. Imaging electrocatalytic activity for oxygen reduction in an acidic medium by the tip generation-substrate collection mode.

    Science.gov (United States)

    Fernández, José L; Bard, Allen J

    2003-07-01

    The oxygen reduction reaction (ORR) in acidic medium was studied on different electrode materials by scanning electrochemical microscopy (SECM) operating in a new variation of the tip generation-substrate collection mode. An ultramicroelectrode tip placed close to the substrate electrode oxidizes water to oxygen at a constant current. The substrate is held at a potential where the tip-generated oxygen is reduced and the resulting substrate current is measured. By changing the substrate potential, it is possible to obtain a polarization (current-potential) curve, which depends on the electrocatalytic activity of the substrate material. The main difference between this mode and the classical feedback SECM mode of operation is that the feedback diffusion process is not required for the measurement, allowing its application for studying the ORR in acidic solutions. Activity-sensitive images of heterogeneous surfaces, e.g., with Pt and Au electrodes, were obtained from the substrate current when the x-y plane was scanned with the tip. The usefulness of this technique for imaging electrocatalytic activity of smooth metallic electrodes and of highly dispersed fuel cell-type electrocatalysts was demonstrated. The application of this method to the combinatorial chemical analysis of electrode materials and electrocatalysts is discussed.

  14. Application of Ganghwa Mugwort in Combination with Ascorbic Acid for the Reduction of Residual Nitrite in Pork Sausage during Refrigerated Storage

    Science.gov (United States)

    Hwang, Ko-Eun; Kim, Hyun-Wook; Song, Dong-Heon; Kim, Yong-Jae; Ham, Youn-Kyung; Lee, Choong-Hee; Choi, Yun-Sang; Kim, Cheon-Jei

    2014-01-01

    The application of ganghwa mugwort (GM), ascorbic acid (AC), and their combinations for reduction of residual nitrite contents was analyzed in pork sausages during storage of 28 d. Six treatments of pork sausages contained the following: Control (no antioxidant added), AC (0.05% AC), GM 0.1 (0.1% GM), GM 0.2 (0.2% GM), AC+GM 0.1 (0.05% AC + 0.1% GM) and AC+GM 0.2 (0.05% AC + 0.2% GM). Results showed that the mixture of 0.05% AC and 0.2% GM was most effective for reducing thiobarbituric acid reactive substances (TBARS) and residual nitrite contents than the control and GM added sausages alone (pcolor values of all treatments were significantly affected by adding GM (either alone or with AC). Additionally, the total color difference (ΔE) and hue angle (H°) values of treatments added with GM were higher than those of the control as the amount of GM increased (p0.05). Our results showed possible applications of antioxidant combination, for preventing the lipid oxidation and decreasing the residual nitrite levels of meat products. PMID:26760936

  15. Tricarboxylic acid cycle intermediates accumulate at the onset of intense exercise in man but are not essential for the increase in muscle oxygen uptake

    DEFF Research Database (Denmark)

    Bangsbo, Jens; Gibala, Martin J.; Howarth, Krista R.

    2006-01-01

    dichloroacetate (DCA) in an attempt to alter the level of TCAI. Five men performed strenuous leg kicking exercise (64+/-8 W) under noninfused control (CON) and DCA-supplemented conditions; biopsies (vastus lateralis) were obtained at rest and after 5, 15, and 180 s of exercise. In CON, the total concentration...... seconds of exercise; however, this increase is not essential for the contraction-induced increase in mitochondrial respiration....

  16. Synthesis of neurotransmitter GABA via the neuronal tricarboxylic acid cycle is elevated in rats with liver cirrhosis consistent with a high GABAergic tone in chronic hepatic encephalopathy

    DEFF Research Database (Denmark)

    Leke, Renata; Bak, Lasse Kristoffer; Iversen, Peter

    2011-01-01

    J. Neurochem. (2011) 117, 824-832. ABSTRACT: Hepatic encephalopathy (HE) is a neuropsychiatric complication to liver disease. It is known that ammonia plays a role in the pathogenesis of HE and disturbances in the GABAergic system have been related to HE. Synthesis of GABA occurs by decarboxylation...

  17. In Situ Scanning Tunneling Microscopy Topography Changes of Gold (111) in Aqueous Sulfuric Acid Produced by Electrochemical Surface Oxidation and Reduction and Relaxation Phenomena

    Science.gov (United States)

    Pasquale, M. A.; Nieto, F. J. Rodríguez; Arvia, A. J.

    The electrochemical formation and reduction of O-layers on gold (111) films in 1 m sulfuric acid under different potentiodynamic routines are investigated utilizing in situ scanning tunneling microscopy. The surface dynamics is interpreted considering the anodic and cathodic reaction pathways recently proposed complemented with concurrent relaxation phenomena occurring after gold (111) lattice mild disruption (one gold atom deep) and moderate disruption (several atoms deep). The dynamics of both oxidized and reduced gold topographies depends on the potentiodynamic routine utilized to form OH/O surface species. The topography resulting from a mild oxidative disruption is dominated by quasi-2D holes and hillocks of the order of 5 nm, involving about 500-600 gold atoms each, and their coalescence. A cooperative turnover process at the O-layer, in which the anion ad-layer and interfacial water play a key role, determines the oxidized surface topography. The reduction of these O-layers results in gold clusters, their features depending on the applied potential routine. A moderate oxidative disruption produces a surface topography of hillocks and holes several gold atoms high and deep, respectively. The subsequent reduction leads to a spinodal gold pattern. Concurrent coalescence appears to be the result of an Ostwald ripening that involves the surface diffusion of both gold atoms and clusters. These processes produce an increase in surface roughness and an incipient gold faceting. The dynamics of different topographies can be qualitatively explained employing the arguments from colloidal science theory. For 1.1 V ≤ E ≅ Epzc weak electrostatic repulsions favor gold atom/cluster coalescence, whereas for E < Epzc the attenuated electrostatic repulsions among gold surfaces stabilize small clusters over the substrate producing string-like patterns.

  18. Reduction of FFA in jatropha curcas oil via sequential direct-ultrasonic irradiation and dosage of methanol/sulfuric acid catalyst mixture on esterification process

    International Nuclear Information System (INIS)

    Andrade-Tacca, Cesar Augusto; Chang, Chia-Chi; Chen, Yi-Hung; Ji, Dar-Ren; Wang, Yi-Yu; Yen, Yue-Quen; Chang, Ching-Yuan

    2014-01-01

    Highlights: • Ultrasonic irradiation (UI) can auto-induce temperature rise. • Esterification at higher temperature (T) by UI offers greater reduction of acid value. • Sequential UI and catalyst dosing enhance esterification conversion efficiency (η). • UR of jatropha oil at higher T results in less water content on ester as product. • A 99.35% of η is achievable via sequential UI and dosing of 5 mL per dose. - Abstract: Production of jatropha-ester (JO-ester) from jatropha oil (JO) under sequential direct-ultrasonic irradiation (UI) with auto-induced temperature rise followed by adding a mixture of methanol/sulfuric-acid catalyst (M/C) dose between high temperature intervals was studied. Comparisons with various doses of 5, 10, 16.6 and 25 mL at different temperature intervals of 108.9–120 °C, 100–120 °C, 85–120 °C and 75–120 °C respectively were performed. System parameters examined include: esterification times (t E ) for UI, settling time (t S ) after esterification and temperature (T). Properties of acid value (AV), iodine value (IV), kinematic viscosity (kV), density (ρ LO ) and water content (m w ) of JO and JO-ester product were measured. The esterification conversion efficiencies (η) were determined and assessed. An η of 99.35% was obtained at temperature interval of 108.9–120 °C with 5 mL per dose for 20 doses and t E of 167.39 min (denoted as Process U 120-5 ), which is slightly higher than η of 98.87% at temperature interval of 75–120 °C with 25 mL per dose for 4 doses and t E of 108.79 min (noted as Process U 120-25 ). The JO-ester obtained via sequential UI with adding doses of 5 mL possess AV of 0.24 mg KOH/g, IV of 124.77 g I 2 /100 g, kV of 9.89 mm 2 /s, ρ LO of 901.73 kg/m 3 and m w of 0.3 wt.% showing that sequential UI and dose at higher temperature interval can give higher reduction of AV compared with 36.56 mg KOH/g of original oil. The effects of t S and t E on AV are of minor and moderate importance

  19. Flower abscission in Vitis vinifera L. triggered by gibberellic acid and shade discloses differences in the underlying metabolic pathways

    Directory of Open Access Journals (Sweden)

    Sara eDomingos

    2015-06-01

    Full Text Available Understanding abscission is both a biological and an agronomic challenge. Flower abscission induced independently by shade and gibberellic acid (GAc sprays was monitored in grapevine (Vitis vinifera L. growing under a soilless greenhouse system during two seasonal growing conditions, in an early and late production cycle. Physiological and metabolic changes triggered by each of the two distinct stimuli were determined. Environmental conditions exerted a significant effect on fruit set as showed by the higher natural drop rate recorded in the late production cycle with respect to the early cycle. Shade and GAc treatments increased the percentage of flower drop compared to the control, and at a similar degree, during the late production cycle. The reduction of leaf gas exchanges under shade conditions was not observed in GAc treated vines. The metabolic profile assessed in samples collected during the late cycle differently affected primary and secondary metabolisms and showed that most of the treatment-resulting variations occurred in opposite trends in inflorescences unbalanced in either hormonal or energy deficit abscission-inducing signals. Particularly concerning carbohydrates metabolism, sucrose, glucose, tricarboxylic acid (TCA metabolites and intermediates of the raffinose family oligosaccharides pathway were lower in shaded and higher in GAc samples. Altered oxidative stress remediation mechanisms and indolacetic acid (IAA concentration were identified as abscission signatures common to both stimuli. According to the global analysis performed, we report that grape flower abscission mechanisms triggered by GAc application and C-starvation are not based on the same metabolic pathways.

  20. Synthesis, Anti-HCV, Antioxidant and Reduction of Intracellular Reactive Oxygen Species Generation of a Chlorogenic Acid Analogue with an Amide Bond Replacing the Ester Bond.

    Science.gov (United States)

    Wang, Ling-Na; Wang, Wei; Hattori, Masao; Daneshtalab, Mohsen; Ma, Chao-Mei

    2016-06-08

    Chlorogenic acid is a well known natural product with important bioactivities. It contains an ester bond formed between the COOH of caffeic acid and the 3-OH of quinic acid. We synthesized a chlorogenic acid analogue, 3α-caffeoylquinic acid amide, using caffeic and quinic acids as starting materials. The caffeoylquinc acid amide was found to be much more stable than chlorogenic acid and showed anti-Hepatitis C virus (anti-HCV) activity with a potency similar to chlorogenic acid. The caffeoylquinc acid amide potently protected HepG2 cells against oxidative stress induced by tert-butyl hydroperoxide.

  1. The effects of ascorbic acid on diphtheria toxin and intoxicated hela cells

    International Nuclear Information System (INIS)

    Clark, C.E.; Smith, T.J.

    1976-01-01

    Ascorbic acid (vitamin C) prevented diphtheria toxin from inhibiting the incorporation of [U- 14 C]-alanine into trichloroacetic acid precipitable material in HeLa cells. Ascorbic acid did not exhibit an effect on the adenosine diphosphate-ribosylation of amino acyl transferase 2 nor did it separate fragment A from fragment B in ''nicked'' toxin. A non-specific reducing agent, para-methylaminophenol sulfate, exhibited an effect of HeLa cells very similar to the results of ascorbic acid. Citric acid, a tricarboxylic acid, had no effect on HeLa cells. (auth.)

  2. Reduction of unwanted submental fat with ATX-101 (deoxycholic acid), an adipocytolytic injectable treatment: results from a phase III, randomized, placebo-controlled study.

    Science.gov (United States)

    Rzany, B; Griffiths, T; Walker, P; Lippert, S; McDiarmid, J; Havlickova, B

    2014-02-01

    Unwanted submental fat (SMF) is aesthetically unappealing, but methods of reduction are either invasive or lack evidence for their use. An injectable approach with ATX-101 (deoxycholic acid) is under investigation. To evaluate the efficacy and safety of ATX-101 for the reduction of unwanted SMF. In this double-blind, placebo-controlled, phase III study, 363 patients with moderate/severe SMF were randomized to receive ATX-101 (1 or 2 mg cm(-2) ) or placebo injections into their SMF at up to four treatment sessions ~28 days apart, with a 12-week follow-up. The co-primary efficacy endpoints were the proportions of treatment responders [patients with ≥ 1-point improvement in SMF on the 5-point Clinician-Reported Submental Fat Rating Scale (CR-SMFRS)] and patients satisfied with their face and chin appearance on the Subject Self-Rating Scale (SSRS). Secondary endpoints included skin laxity, calliper measurements and patient-reported outcomes. Adverse events were monitored. Significantly more ATX-101 recipients met the primary endpoint criteria vs. placebo: on the clinician scale, 59·2% and 65·3% of patients treated with ATX-101 1 and 2 mg cm(-2) , respectively, were treatment responders vs. 23·0% for placebo (CR-SMFRS; P < 0·001); on the patient scale, 53·3% and 66·1%, respectively, vs. 28·7%, were satisfied with their face/chin appearance (SSRS; P < 0·001). Calliper measurements showed a significant reduction in SMF (P < 0·001), skin laxity was not worsened and patients reported improvements in the severity and psychological impact of SMF with ATX-101 vs. placebo. Most adverse events were transient and associated with the treatment area. ATX-101 was effective and well tolerated for nonsurgical SMF reduction. © 2013 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

  3. Electrochemical reduction of oxygen on small platinum particles supported on carbon in concentrated phosphoric acid. 2. Effects of teflon content in the catalyst layer and baking temperature of the electrode

    Energy Technology Data Exchange (ETDEWEB)

    Maoka, T.

    1988-03-01

    A relation between hydrophobicity (or wettability) of a porous gas diffusion electrode for use in a phosphoric acid fuel cell and its cathode performance (activity toward electrochemical oxygen reduction) was examined. The hydrophobicity of the gas diffusion electrode was regulated by changing either the amount of Teflon (PTFE) content in the catalyst layer or baking temperature of the electrode. The Tafel slope or electrochemical oxygen reduction became twice as high as that of the ordinary electrode when the wettability of electrode toward phosphoric acid was high. This fact supports a flooded agglomerate model as the mode of this type of porous gas diffusion electrode.

  4. The Krebs Uric Acid Cycle: A Forgotten Krebs Cycle.

    Science.gov (United States)

    Salway, Jack G

    2018-05-25

    Hans Kornberg wrote a paper entitled 'Krebs and his trinity of cycles' commenting that every school biology student knows of the Krebs cycle, but few know that Krebs discovered two other cycles. These are (i) the ornithine cycle (urea cycle), (ii) the citric acid cycle (tricarboxylic acid or TCA cycle), and (iii) the glyoxylate cycle that was described by Krebs and Kornberg. Ironically, Kornberg, codiscoverer of the 'glyoxylate cycle', overlooked a fourth Krebs cycle - (iv) the uric acid cycle. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Whey protein and essential amino acids promote the reduction of adipose tissue and increased muscle protein synthesis during caloric restriction-induced weight loss in elderly, obese individuals

    Directory of Open Access Journals (Sweden)

    Coker Robert H

    2012-12-01

    Full Text Available Abstract Background Excess adipose tissue and sarcopenia presents a multifaceted clinical challenge that promotes morbidity and mortality in the obese, elderly population. Unfortunately, the mortality risks of muscle loss may outweigh the potential benefits of weight loss in the elderly. We have previously demonstrated the effectiveness of whey protein and essential amino acids towards the preservation of lean tissue, even under the conditions of strict bedrest in the elderly. Methods In the context of caloric restriction-based weight loss, we hypothesized that a similar formulation given as a meal replacement (EAAMR would foster the retention of lean tissue through an increase in the skeletal muscle fractional synthesis rate (FSR. We also proposed that EAAMR would promote the preferential loss of adipose tissue through the increased energy cost of skeletal muscle FSR. We recruited and randomized 12 elderly individuals to an 8 week, caloric restriction diet utilizing equivalent caloric meal replacements (800 kcal/day: 1 EAAMR or a 2 competitive meal replacement (CMR in conjunction with 400 kcal of solid food that totaled 1200 kcal/day designed to induce 7% weight loss. Combined with weekly measurements of total body weight and body composition, we also measured the acute change in the skeletal muscle FSR to EAAMR and CMR. Results By design, both groups lost ~7% of total body weight. While EAAMR did not promote a significant preservation of lean tissue, the reduction in adipose tissue was greater in EAAMR compared to CMR. Interestingly, these results corresponded to an increase in the acute skeletal muscle protein FSR. Conclusion The provision of EAAMR during caloric restriction-induced weight loss promotes the preferential reduction of adipose tissue and the modest loss of lean tissue in the elderly population.

  6. Homocysteine-Lowering and Cardiovascular Disease Outcomes in Kidney Transplant Recipients: Primary Results from the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial

    Science.gov (United States)

    Bostom, Andrew G.; Carpenter, Myra A.; Kusek, John W.; Levey, Andrew S.; Hunsicker, Lawrence; Pfeffer, Marc A.; Selhub, Jacob; Jacques, Paul F.; Cole, Edward; Gravens-Mueller, Lisa; House, Andrew A.; Kew, Clifton; McKenney, Joyce L.; Pacheco-Silva, Alvaro; Pesavento, Todd; Pirsch, John; Smith, Stephen; Solomon, Scott; Weir, Matthew

    2015-01-01

    Background Kidney transplant recipients, like other patients with chronic kidney disease (CKD), experience excess risk of cardiovascular disease (CVD) and elevated total homocysteine (tHcy) concentrations. Observational studies of patients with CKD suggest increased homocysteine is a risk factor for CVD. The impact of lowering total homocysteine (tHcy) levels in kidney transplant recipients is unknown. Methods and Results In a double-blind controlled trial, we randomized 4110 stable kidney transplant recipients to a multivitamin that included either a high dose (n=2056) or low dose (n=2054) of folic acid, vitamin B6, and vitamin B12 to determine whether decreasing tHcy concentrations reduced the rate of the primary composite arteriosclerotic CVD outcome (myocardial infarction, stroke, CVD death, resuscitated sudden death, coronary artery or renal artery revascularization, lower extremity arterial disease, carotid endarterectomy or angioplasty, or abdominal aortic aneurysm repair). Mean follow-up was 4.0 years. Treatment with the high dose multivitamin reduced homocysteine but did not reduce the rates of the primary outcome (n= 547 total events; hazards ratio [95% confidence interval] = 0.99 [0.84–1.17]), or secondary outcomes of all-cause mortality (n=431 deaths; 1.04 [0.86–1.26]) or dialysis-dependent kidney failure (n=343 events; 1.15 [0.93–1.43]) compared to the low dose multivitamin. Conclusions Treatment with a high dose folic acid, B6, and B12 multivitamin in kidney transplant recipients did not reduce a composite cardiovascular disease outcome, all-cause mortality, or dialysis-dependent kidney failure despite significant reduction in homocysteine level. PMID:21482964

  7. Chemical evolution studies: the radiolysis and thermal decomposition of malonic acid

    International Nuclear Information System (INIS)

    Cruz-Castaneda, J.; Negron-Mendoza, A.; Heredia, A.; Ramos-Bernal, S.; Villafane-Barajas, S.; Frias, D.; Colin-Garcia, M.

    2015-01-01

    In the context of chemical evolution a simulation of a hydrothermal vent was performed. The thermolysis and radiolysis of malonic acid in aqueous solution were studied. The thermolysis was done by heating the samples (95 deg C) and radiolysis using gamma radiation. Products were identified by gas chromatography and gas chromatography-mass spectrometry. The thermal treatment produced acetic acid and CO 2 . The radiolysis experiments yield carbon dioxide, acetic acid, and di- and tricarboxylic acids. A theoretical model of the chemical process occurring under irradiation was developed; this was able to reproduce formation of products and the consumption of malonic acid. (author)

  8. Optimization of strawberry disinfection by fogging of a mixture of peracetic acid and hydrogen peroxide based on microbial reduction, color and phytochemicals retention.

    Science.gov (United States)

    Van de Velde, Franco; Vaccari, María Celia; Piagentini, Andrea Marcela; Pirovani, María Élida

    2016-09-01

    The fogging of strawberries using a environmentally friendly sanitizer mixture of peracetic acid (5%) and hydrogen peroxide (20%) was performed in a model chamber and modeled as a function of the concentration (3.4, 20.0, 60.0, 100.0 and 116.6 µL sanitizer L(-) (1) air chamber) and the treatment time (5.7, 15.0, 37.5, 60.0 and 69.3 min). The sanitizer fogging was adequate for reducing total mesophilic microbial and yeasts and moulds counts of fruits until seven days of storage at 2℃. However, sanitizer oxidant properties adversely affected the content of total anthocyanins, total phenolics, vitamin C, and antioxidant capacity to various degrees, with some deleterious changes in the fruits color, depending on the fogging conditions. A multiple numeric response optimization was developed based on 2.0 log microbiological reduction, maximum phytochemicals and antioxidant capacity retentions, with no changes in the fruits color, being the optimal fogging conditions achieved: 10.1 µL sanitizer L(-1) air chamber and 29.6 min. The fogging of strawberries at these conditions may represent a promising postharvest treatment option for extending their shelf-life without affecting their sensory quality and bioactive properties. © The Author(s) 2016.

  9. Porous carbon supported Fe-N-C composite as an efficient electrocatalyst for oxygen reduction reaction in alkaline and acidic media

    Science.gov (United States)

    Liu, Baichen; Huang, Binbin; Lin, Cheng; Ye, Jianshan; Ouyang, Liuzhang

    2017-07-01

    In recent years, non-precious metal electrocatalysts for oxygen reduction reaction (ORR) have attracted tremendous attention due to their high catalytic activity, long-term stability and excellent methanol tolerance. Herein, the porous carbon supported Fe-N-C catalysts for ORR were synthesized by direct pyrolysis of ferric chloride, 6-Chloropyridazin-3-amine and carbon black. Variation of pyrolysis temperature during the synthesis process leads to the difference in ORR catalytic activity. High pyrolysis temperature is beneficial to the formation of the "N-Fe" active sites and high electrical conductivity, but the excessive temperature will cause the decomposition of nitrogen-containing active sites, which are revealed by Raman, TGA and XPS. A series of synthesis and characterization experiments with/without nitrogen or iron in carbon black indicate that the coordination of iron and nitrogen plays a crucial role in achieving excellent ORR performances. Electrochemical test results show that the catalyst pyrolyzed at 800 °C (Fe-N-C-800) exhibits excellent ORR catalytic activity, better methanol tolerance and higher stability compared with commercial Pt/C catalyst in both alkaline and acidic conditions.

  10. Potential use of gypsum and lime rich industrial by-products for induced reduction of Pb, Zn and Ni leachability in an acid soil

    International Nuclear Information System (INIS)

    Rodriguez-Jorda, M.P.; Garrido, F.; Garcia-Gonzalez, M.T.

    2010-01-01

    This study evaluates the potential use of four industrial by-products (phosphogypsum (PG), red gypsum (RG), sugar foam (SF), and ashes from biomass combustion (ACB)), applied at two rates in single and combined amendments to reduce the mobility and availability of Pb, Zn and Ni in a metal-spiked acid soil. Leaching experiments were done to estimate leachability indexes and assess their effectiveness. Most of the treatments significantly reduced the metal leachability although only a few were effective for all metals. Based on principal component and cluster analysis, sugar foam (SF) and a mixture of RG and ACB (RG+ACB), both applied at high rate, were selected as first choices to reduce mobility and availability of the three metals. Metal sorption mechanisms involved in the reduction of their leachability were identified using scanning electron microscopy. In the SF-treated samples, the metals were found associated to amorphous Al-hydroxy polymers deposited on phyllosilicates and organic matter particles. In the (RG+ACB)-treated samples, Pb, Zn, and traces of Ni were found associated to Fe/Ti oxide phases with a significant concentration of S, suggesting the formation of metal-sulfate ternary complexes.

  11. Analysis of l-glutamic acid fermentation by using a dynamic metabolic simulation model of Escherichia coli

    OpenAIRE

    Nishio, Yousuke; Ogishima, Soichi; Ichikawa, Masao; Yamada, Yohei; Usuda, Yoshihiro; Masuda, Tadashi; Tanaka, Hiroshi

    2013-01-01

    Background Understanding the process of amino acid fermentation as a comprehensive system is a challenging task. Previously, we developed a literature-based dynamic simulation model, which included transcriptional regulation, transcription, translation, and enzymatic reactions related to glycolysis, the pentose phosphate pathway, the tricarboxylic acid (TCA) cycle, and the anaplerotic pathway of Escherichia coli. During simulation, cell growth was defined such as to reproduce the experimental...

  12. Cross-talk between branched-chain amino acids and hepatic mitochondria is compromised in nonalcoholic fatty liver disease

    OpenAIRE

    Sunny, Nishanth E.; Kalavalapalli, Srilaxmi; Bril, Fernando; Garrett, Timothy J.; Nautiyal, Manisha; Mathew, Justin T.; Williams, Caroline M.; Cusi, Kenneth

    2015-01-01

    Elevated plasma branched-chain amino acids (BCAA) in the setting of insulin resistance have been relevant in predicting type 2 diabetes mellitus (T2DM) onset, but their role in the etiology of hepatic insulin resistance remains uncertain. We determined the link between BCAA and dysfunctional hepatic tricarboxylic acid (TCA) cycle, which is a central feature of hepatic insulin resistance and nonalcoholic fatty liver disease (NAFLD). Plasma metabolites under basal fasting and euglycemic hyperin...

  13. Branched-Chain Amino Acid Levels Are Related with Surrogates of Disturbed Lipid Metabolism among Older Men

    OpenAIRE

    Urho M Kujala; Markku Peltonen; Merja K. Laine; Merja K. Laine; Jaakko Kaprio; Jaakko Kaprio; Jaakko Kaprio; Olli. J. Heinonen; Jouko Sundvall; Johan G. Eriksson; Johan G. Eriksson; Johan G. Eriksson; Antti Jula; Seppo Sarna; Heikki Kainulainen

    2016-01-01

    Aims/hypothesis Existing studies suggest that decreased branched-chain amino acid (BCAA) catabolism and thus elevated levels in blood are associated with metabolic disturbances. Based on such information we have developed a hypothesis how BCAA degradation mechanistically connects to tricarboxylic acid (TCA) cycle, intramyocellular lipid storage and oxidation thus allowing more efficient mitochondrial energy production from lipids as well as providing better metabolic health. We analyzed wheth...

  14. Metabolomic analysis of alterations in lipid oxidation, carbohydrate and amino acid metabolism in dairy goats caused by exposure to Aflotoxin B1.

    Science.gov (United States)

    Cheng, Jianbo; Huang, Shuai; Fan, Caiyun; Zheng, Nan; Zhang, Yangdong; Li, Songli; Wang, Jiaqi

    2017-11-01

    The purposes of this study were to investigate the systemic and characteristic metabolites in the serum of dairy goats induced by aflatoxin B1 (AFB1) exposure and to further understand the endogenous metabolic alterations induced by it. A nuclear magnetic resonance (NMR)-based metabonomic approach was used to analyse the metabolic alterations in dairy goats that were induced by low doses of AFB1 (50 µg/kg DM). We found that AFB1 exposure caused significant elevations of glucose, citrate, acetate, acetoacetate, betaine, and glycine yet caused reductions of lactate, ketone bodies (acetate, β-hydroxybutyrate), amino acids (citrulline, leucine/isoleucine, valine, creatine) and cell membrane structures (choline, lipoprotein, N-acetyl glycoproteins) in the serum. These data indicated that AFB1 caused endogenous metabolic changes in various metabolic pathways, including cell membrane-associated metabolism, the tricarboxylic acid cycle, glycolysis, lipids, and amino acid metabolism. These findings provide both a comprehensive insight into the metabolic aspects of AFB1-induced adverse effects on dairy goats and a method for monitoring dairy animals exposed to low doses of AFB1.

  15. The benefits of folic acid-modified gold nanoparticles in CT-based molecular imaging: radiation dose reduction and image contrast enhancement.

    Science.gov (United States)

    Beik, Jaber; Jafariyan, Maryam; Montazerabadi, Alireza; Ghadimi-Daresajini, Ali; Tarighi, Parastoo; Mahmoudabadi, Alireza; Ghaznavi, Habib; Shakeri-Zadeh, Ali

    2017-12-12

    X-ray computed tomography (CT) requires an optimal compromise between image quality and patient dose. While high image quality is an important requirement in CT, the radiation dose must be kept minimal to protect the patients from ionizing radiation-associated risks. The use of probes based on gold nanoparticles (AuNPs) along with active targeting ligands for specific recognition of cancer cells may be one of the balanced solutions. Herein, we report the effect of folic acid (FA)-modified AuNP as a targeted nanoprobe on the contrast enhancement of CT images as well as its potential for patient dose reduction. For this purpose, nasopharyngeal KB cancer cells overexpressing FA receptors were incubated with AuNPs with and without FA modification and imaged in a CT scanner with the following X-ray tube parameters: peak tube voltage of 130 KVp, and tube current-time products of 60, 90, 120, 160 and 250 mAs. Moreover, in order to estimate the radiation dose to which the patient was exposed during a head CT protocol, the CT dose index (CTDI) value was measured by an X-ray electrometer by changing the tube current-time product. Raising the tube current-time product from 60 to 250 mAs significantly increased the absorbed dose from 18 mGy to 75 mGy. This increase was not associated with a significant enhancement of the image quality of the KB cells. However, an obvious increase in image brightness and CT signal intensity (quantified by Hounsfield units [HU]) were observed in cells exposed to nanoparticles without any increase in the mAs product or radiation dose. Under the same Au concentration, KB cells exposed to FA-modified AuNPs had significantly higher HU and brighter CT images than those of the cells exposed to AuNPs without FA modification. In conclusion, FA-modified AuNP can be considered as a targeted CT nanoprobe with the potential for dose reduction by keeping the required mAs product as low as possible while enhancing image contrast.

  16. Unique catalytic properties of a butoxy chain-containing ruthenated porphyrin towards oxidation of uric acid and reduction of dioxygen for visible light-enhanced fuel cells

    International Nuclear Information System (INIS)

    Liu, Junchen; Wang, Yi; Deng, Qiang; Zhu, Licai; Chao, Hui; Li, Hong

    2016-01-01

    Highlights: • Ru(II)PTPP/CdS shows two Ru(II)-based oxidation peaks at 0.296 V and 0.830 V. • Photoelectrocatalytic oxidation of UA exhibits good linear responses. • The butoxy chain endows Ru(II)PTPP with multifunctional catalytic properties. • Ru(II)PTPP on CF electrode can remarkably promote the reduction of oxygen. • The assembled cell has I_S_C of 0.136 mA cm"−"2 and P_m_a_x of 31.50 μW cm"−"2. - Abstract: This paper reports the photoelectrocatalytic activities of a ruthenated porphyrin [Ru(phen)_2(IP-C_4O-TPP)]"2"+ (denoted as Ru(II)PTPP, phen = 1,10-phenanthroline, IP = imidazo[4,5-f][1,10]phenanthroline and TPP = 5,10,15,20-tetraphenylporphyrin) containing a covalently-linked butoxy chain (-C_4O-) between IP and TPP moieties by means of various electrochemical techniques in combination with absorption spectroscopy and scanning electronic microscopy. Ru(II)PTPP is assembled on the surface of CdS nanoparticles, showing two Ru(II)-based peaks at 0.296 V and 0.830 V, where uric acid (UA) can be photoelectrocatalytically oxidized in a linear range of 0.01-10.0 mmol L"−"1. The −C_4O- chain endows the Ru(II)PTPP/carbon felt (CF) electrode with favorable dioxygen (O_2) binding sites to achieve a couple of new redox peaks at −0.213 V, where O_2 involves electrocatalytic reduction reactions. While employing 5.0 mmol L"−"1 UA as fuel, and 60 mL min"−"1 O_2 as oxidant, the proposed photoelectrochemical fuel cell shows open-circuit photovoltage of 0.656 V, short-circuit photocurrent density of 0.136 mA cm"−"2, and maximum power density of 31.50 μW cm"−"2 at 0.497 V under visible-light illumination of 0.18 mW cm"−"2. The present study provides an interesting platform for the utilization of renewable energy sources.

  17. The effect of electrochemical CO annealing on platinum–cobalt nanoparticles in acid medium and their correlation to the oxygen reduction reaction

    International Nuclear Information System (INIS)

    Ciapina, Eduardo G.; Ticianelli, Edson A.

    2011-01-01

    Highlights: ► Modification of the surface properties of Pt 3 Co/C electrocatalyst. ► Electrochemical CO annealing in acid media generated a Pt-rich surface. ► In situ XAS revealed modifications in the Pt 5d band occupancy after CO annealing. ► The CO-annealed sample exhibited stronger interaction with oxygenated species. ► Increased Pt utilization in the CO-annealed Pt 3 Co/C electrocatalyst. - Abstract: This paper describes a modification of the surface properties of a carbon-supported Pt 3 Co catalyst resulting from an electrochemical cycling treatment in a 0.1 M HClO 4 and in a CO-saturated 0.1 M HClO 4 solution (electrochemical CO-annealing). The procedure generated a Pt-rich surface with electrochemical properties different from that presented by the as-received (untreated) sample. This was evidenced by a shift in the CO stripping peak to more positive potentials in the CO stripping voltammetry, and by an increased charge of H upd region and a modification of the oxide reduction peak observed in the base cyclic voltammogram. In situ X-ray absorption spectroscopy experiments conducted in the dispersive mode revealed differences in the electronic 5d band occupancy after the CO annealing, whereas the behavior of the intensity of the white-line as function of the potential for this material approached that found for pure Pt/C nanoparticles, in contrast to the small potential dependence profile exhibited by the as-received Pt 3 Co nanoparticles. Mass activities towards the oxygen reduction reaction measured by rotating disk experiments carried out at 1600 rpm in a O 2 -saturated solution at 25 °C increased from 0.10 A/mg of Pt to 0.19 A/mg of Pt, evidencing the higher Pt utilization in the CO-annealed Pt 3 Co/C electrocatalyst. The origin of the different electrochemical behavior is discussed.

  18. Determination of plutonium in nitric acid solutions - Method by oxidation by cerium(IV), reduction by iron(II) ammonium sulfate and amperometric back-titration with potassium dichromate

    International Nuclear Information System (INIS)

    1987-01-01

    This International Standard specifies a precise and accurate analytical method for determining plutonium in nitric acid solutions. Plutonium is oxidized to plutonium(VI) in a 1 mol/l nitric acid solution with cerium(IV). Addition of sulfamic acid prevents nitrite-induced side reactions. The excess of cerium(IV) is reduced by adding a sodium arsenite solution, catalysed by osmium tetroxide. A slight excess of arsenite is oxidized by adding a 0.2 mol/l potassium permanganate solution. The excess of permanganate is reduced by adding a 0.1 mol/l oxalic acid solution. Iron(III) is used to catalyse the reduction. A small excess of oxalic acid does not interfere in the subsequent plutonium determination. These reduction and oxidation stages can be followed amperometrically and the plutonium is left in the hexavalent state. The sulfuric acid followed by a measured amount of standardized iron(II) ammonium sulfate solution in excess of that required to reduce the plutonium(VI) to plutonium(IV) is added. The excess iron(II) and any plutonium(III) formed to produce iron(III) and plutonium(IV) is amperometrically back-titrated using a standard potassium dichromate solution. The method is almost specifically for plutonium. It is suitable for the direct determination of plutonium in materials ranging from pure product solutions, to fast reactor fuel solutions with a uranium/plutonium ratio of up to 10:1, either before or after irradiation

  19. Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid

    Science.gov (United States)

    Romo Vaquero, María; Yáñez-Gascón, María-Josefa; García Villalba, Rocío; Larrosa, Mar; Fromentin, Emilie; Ibarra, Alvin; Roller, Marc; Tomás-Barberán, Francisco; Espín de Gea, Juan Carlos; García-Conesa, María-Teresa

    2012-01-01

    Background Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. Methods and Principal Findings RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. Conclusions Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption. PMID:22745826

  20. Reduction of sodium and increment of calcium and ω-3 polyunsaturated fatty acids in dry fermented sausages: effects on the mineral content, lipid profile and sensory quality.

    Science.gov (United States)

    García-Íñiguez de Ciriano, Mikel; Berasategi, Izaskun; Navarro-Blasco, Iñigo; Astiasarán, Iciar; Ansorena, Diana

    2013-03-15

    A combined technological approach was applied in the development of healthier dry fermented sausages: a partial substitution of the pork back fat by pre-emulsified linseed oil and a partial replacement of sodium chloride with calcium ascorbate at two different levels, leading to low amounts of salt (14gSalt and 10gSalt, with 14 g and 10 g NaCl per kg of mixture, respectively). The developed products (14gSalt and 10gSalt) showed adequate results for a(w) (0.85 and 0.87) and pH (4.98 and 5.21), and low lipid oxidation values (1.4 × 10(-4) and 1.5 × 10(-5) g malondialdehyde (MDA) kg(-1)). The lipid modification led to a significantly higher supply of ω-3 (23.3 g kg(-1) ) compared to the control (3.2 g kg(-1) ). Simultaneously, reductions of 38% and 50% in sodium content and a calcium supply of 4 and 5.2 g kg(-1) were achieved in the 14gSalt and 10gSalt formulations, respectively, compared to the control products (26 g salt and 0.87 g kg(-1) Ca). Instrumental analysis of colour and texture and sensory studies demonstrated that the organoleptic quality of the new formulations was similar to that of traditional products. The developed dry fermented sausages showed healthier properties than traditional ones owing to their reduced sodium and higher calcium content and a significant supply of ω-3 fatty acids. © 2012 Society of Chemical Industry.

  1. Inhibition of gastric lipase as a mechanism for body weight and plasma lipids reduction in Zucker rats fed a rosemary extract rich in carnosic acid.

    Directory of Open Access Journals (Sweden)

    María Romo Vaquero

    Full Text Available BACKGROUND: Rosemary (Rosmarinus officinalis L. extracts (REs exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40% modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. METHODS AND PRINCIPAL FINDINGS: RE was administered for 64 days to lean (fa/+ and obese (fa/fa female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. CONCLUSIONS: Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption.

  2. Reduction of plasma homocyst(e)ine levels by breakfast cereal fortified with folic acid in patients with coronary heart disease.

    Science.gov (United States)

    Malinow, M R; Duell, P B; Hess, D L; Anderson, P H; Kruger, W D; Phillipson, B E; Gluckman, R A; Block, P C; Upson, B M

    1998-04-09

    The Food and Drug Administration (FDA) has recommended that cereal-grain products be fortified with folic acid to prevent congenital neural-tube defects. Since folic acid supplementation reduces levels of plasma homocyst(e)ine, or plasma total homocysteine, which are frequently elevated in arterial occlusive disease, we hypothesized that folic acid fortification might reduce plasma homocyst(e)ine levels. To test this hypothesis, we assessed the effects of breakfast cereals fortified with three levels of folic acid, and also containing the recommended dietary allowances of vitamins B6 and B12, in a randomized, double-blind, placebo-controlled, crossover trial in 75 men and women with coronary artery disease. Plasma folic acid increased and plasma homocyst(e)ine decreased proportionately with the folic acid content of the breakfast cereal. Cereal providing 127 microg of folic acid daily, approximating the increased daily intake that may result from the FDA's enrichment policy, increased plasma folic acid by 31 percent (P=0.045) but decreased plasma homocyst(e)ine by only 3.7 percent (P= 0.24). However, cereals providing 499 and 665 microg of folic acid daily increased plasma folic acid by 64.8 percent (Pine by 11.0 percent (Pine levels. Further clinical trials are required to determine whether folic acid fortification may prevent vascular disease. Until then, our results suggest that folic acid fortification at levels higher than that recommended by the FDA may be warranted.

  3. The Effect of Acidic and Redox Properties of V2O5/CeO2-ZrO2 Catalysts in Selective Catalytic Reduction of NO by NH3

    DEFF Research Database (Denmark)

    Putluru, Siva Sankar Reddy; Riisager, Anders; Fehrmann, Rasmus

    2009-01-01

    V2O5 supported ZrO2 and CeO2–ZrO2 catalysts were prepared and characterized by N2 physisorption, XRPD, TPR, and NH3-TPD methods. The influence of calcination temperature from 400 to 600 °C on crystallinity, acidic and redox properties were studied and compared with the catalytic activity...... in the selective catalytic reduction (SCR) of NO with ammonia. The surface area of the catalysts decreased gradually with increasing calcination temperature. The SCR activity of V2O5/ZrO2 catalysts was found to be related with the support crystallinity, whereas V2O5/CeO2–ZrO2 catalysts were also dependent...... on acidic and redox properties of the catalyst. The V2O5/CeO2–ZrO2 catalysts showed high activity and selectivity for reduction of NO with NH3....

  4. Reduction of the DNA damages, Hepatoprotective Effect and Antioxidant Potential of the Coconut Water, ascorbic and Caffeic Acids in Oxidative Stress Mediated by Ethanol

    Directory of Open Access Journals (Sweden)

    VANDERSON S. BISPO

    Full Text Available ABSTRACT Hepatic disorders such as steatosis and alcoholic steatohepatitis are common diseases that affect thousands of people around the globe. This study aims to identify the main phenol compounds using a new HPLC-ESI+-MS/MS method, to evaluate some oxidative stress parameters and the hepatoprotective action of green dwarf coconut water, caffeic and ascorbic acids on the liver and serum of rats treated with ethanol. The results showed five polyphenols in the lyophilized coconut water spiked with standards: chlorogenic acid (0.18 µM, caffeic acid (1.1 µM, methyl caffeate (0.03 µM, quercetin (0.08 µM and ferulic acid (0.02 µM isomers. In the animals, the activity of the serum γ-glutamyltranspeptidase (γ-GT was reduced to 1.8 I.U/L in the coconut water group, 3.6 I.U/L in the ascorbic acid group and 2.9 I.U/L in the caffeic acid groups, when compared with the ethanol group (5.1 I.U/L, p<0.05. Still in liver, the DNA analysis demonstrated a decrease of oxidized bases compared to ethanol group of 36.2% and 48.0% for pretreated and post treated coconut water group respectively, 42.5% for the caffeic acid group, and 34.5% for the ascorbic acid group. The ascorbic acid was efficient in inhibiting the thiobarbituric acid reactive substances (TBARS in the liver by 16.5% in comparison with the ethanol group. These data indicate that the green dwarf coconut water, caffeic and ascorbic acids have antioxidant, hepatoprotective and reduced DNA damage properties, thus decreasing the oxidative stress induced by ethanol metabolism.

  5. Is there in vivo evidence for amino acid shuttles carrying ammonia from neurons to astrocytes?

    Science.gov (United States)

    Rothman, Douglas L; De Feyter, Henk M; Maciejewski, Paul K; Behar, Kevin L

    2012-11-01

    The high in vivo flux of the glutamate/glutamine cycle puts a strong demand on the return of ammonia released by phosphate activated glutaminase from the neurons to the astrocytes in order to maintain nitrogen balance. In this paper we review several amino acid shuttles that have been proposed for balancing the nitrogen flows between neurons and astrocytes in the glutamate/glutamine cycle. All of these cycles depend on the directionality of glutamate dehydrogenase, catalyzing reductive glutamate synthesis (forward reaction) in the neuron in order to capture the ammonia released by phosphate activated glutaminase, while catalyzing oxidative deamination of glutamate (reverse reaction) in the astrocytes to release ammonia for glutamine synthesis. Reanalysis of results from in vivo experiments using (13)N and (15)N labeled ammonia and (15)N leucine in rats suggests that the maximum flux of the alanine/lactate or branched chain amino acid/branched chain amino acid transaminase shuttles between neurons and astrocytes are approximately 3-5 times lower than would be required to account for the ammonia transfer from neurons to astrocytes needed for glutamine synthesis (amide nitrogen) to sustain the glutamate/glutamine cycle. However, in the rat brain both the total ammonia fixation rate by glutamate dehydrogenase and the total branched chain amino acid transaminase activity are sufficient to support a branched chain amino acid/branched chain keto acid shuttle, as proposed by Hutson and coworkers, which would support the de novo synthesis of glutamine in the astrocyte to replace the ~20 % of neurotransmitter glutamate that is oxidized. A higher fraction of the nitrogen needs of total glutamate neurotransmitter cycling could be supported by hybrid cycles in which glutamate and tricarboxylic acid cycle intermediates act as a nitrogen shuttle. A limitation of all in vivo studies in animals conducted to date is that none have shown transfer of nitrogen for glutamine amide

  6. Comparative Efficacy of Amoxicillin/Clavulanic Acid and Levofloxacin in the Reduction of Postsurgical Sequelae After Third Molar Surgery: A Randomized, Double-Blind, Clinical Trial in a Nigerian University Teaching Hospital.

    Science.gov (United States)

    Ndukwe, Kizito Chioma; Braimah, Ramat Oyebunmi; Owotade, John Foluso; Aregbesola, Stephen Babatunde

    2016-01-01

    The most common sequelae after surgical removal of mandibular third molar are pain, trismus, swelling, and dysphagia. However, these symptoms can also signal the onset of surgical site infection and alveoli osteitis. The aim of this study was to evaluate the efficacy of prophylactic amoxicillin/clavulanic acid and levofloxacin and preemptive therapy of amoxicillin/clavulanic acid in the reduction of postinflammatory complications, surgical site infection, and alveolar osteitis following the third molar surgery. A total of 135 patients were randomized into three equal groups: Group A (preemptive therapy of amoxicillin/clavulanic acid) with preoperative dose of 875/125 mg amoxicillin/clavulanic acid followed by 500/125 mg amoxicillin/clavulanic acid 12 hourly for 5 days, Group B (amoxicillin/clavulanic acid prophylaxis) with a single preoperative dose of amoxicillin/clavulanic acid 875/125 mg tablets, and Group C (levofloxacin prophylaxis) with a single preoperative dose of levofloxacin 1000 mg tablets. All patients had ostectomy using surgical handpiece and burs and received same analgesics (tabs ibuprofen 400 mg 8 hourly for 3 days). No case of surgical site infection or alveoli osteitis was recorded in the study groups. There were no statistically significant differences between the treatment groups with regard to pain, mouth opening, postoperative facial dimension, and body temperature. Amoxicillin/clavulanic acid as a single preoperative bolus should be adequate for the prevention of postoperative wound infection and alveoli osteitis following the third molar extraction as there is no need for an extension of the antibiotic. Moreover, levofloxacin can be utilized as prophylaxis in patients undergoing mandibular third molar extraction if such patients are allergic to penicillins.

  7. Comparative efficacy of amoxicillin/clavulanic acid and levofloxacin in the reduction of postsurgical sequelae after third molar surgery: a randomized, double-blind, clinical trial in a Nigerian university teaching hospital

    Directory of Open Access Journals (Sweden)

    Kizito Chioma Ndukwe

    2016-01-01

    Full Text Available Background: The most common sequelae after surgical removal of mandibular third molar are pain, trismus, swelling, and dysphagia. However, these symptoms can also signal the onset of surgical site infection and alveoli osteitis. The aim of this study was to evaluate the efficacy of prophylactic amoxicillin/clavulanic acid and levofloxacin and preemptive therapy of amoxicillin/clavulanic acid in the reduction of postinflammatory complications, surgical site infection, and alveolar osteitis following the third molar surgery. Patients and Methods: A total of 135 patients were randomized into three equal groups: Group A (preemptive therapy of amoxicillin/clavulanic acid with preoperative dose of 875/125 mg amoxicillin/clavulanic acid followed by 500/125 mg amoxicillin/clavulanic acid 12 hourly for 5 days, Group B (amoxicillin/clavulanic acid prophylaxis with a single preoperative dose of amoxicillin/clavulanic acid 875/125 mg tablets, and Group C (levofloxacin prophylaxis with a single preoperative dose of levofloxacin 1000 mg tablets. All patients had ostectomy using surgical handpiece and burs and received same analgesics (tabs ibuprofen 400 mg 8 hourly for 3 days. Results: No case of surgical site infection or alveoli osteitis was recorded in the study groups. There were no statistically significant differences between the treatment groups with regard to pain, mouth opening, postoperative facial dimension, and body temperature. Conclusion: Amoxicillin/clavulanic acid as a single preoperative bolus should be adequate for the prevention of postoperative wound infection and alveoli osteitis following the third molar extraction as there is no need for an extension of the antibiotic. Moreover, levofloxacin can be utilized as prophylaxis in patients undergoing mandibular third molar extraction if such patients are allergic to penicillins.

  8. Simple one-pot synthesis of platinum-palladium nanoflowers with enhanced catalytic activity and methanol-tolerance for oxygen reduction in acid media

    International Nuclear Information System (INIS)

    Zheng, Jie-Ning; He, Li-Li; Chen, Fang-Yi; Wang, Ai-Jun; Xue, Meng-Wei; Feng, Jiu-Ju

    2014-01-01

    Graphical abstract: PtPd nanoflowers were fabricated by one-pot solvothermal co-reduction method in oleylamine system, which exhibited the improved electrocatalytic activity and higher methanol tolerance for oxygen reduction, compared with commercial Pt and Pd black catalysts. - Highlights: • Bimetallic alloyed PtPd nanoflowers are prepared by a simple one-pot solvothermal co-reduction method. • PtPd nanoflowers display high catalytic performance for ORR dominated by a four-electron pathway. • PtPd nanoflowers show good methanol tolerance for ORR. - Abstract: In this work, bimetallic alloyed platinum-palladium (PtPd) nanoflowers are fabricated by one-pot solvothermal co-reduction of Pt (II) acetylacetonate and Pd (II) acetylacetonate in oleylamine system. The as-prepared nanostructures show the enhanced electrocatalytic activity for oxygen reduction reaction (ORR), dominated by a four-electron pathway based on the Koutecky-Levich plots, mainly owing to the inhibition of the formation of Pt–OH ad via the downshift of d-band center for Pt. Meanwhile, PtPd nanoflowers display good methanol tolerance and improved stability for ORR. The chronoamperometry test reveals that the current of PtPd nanoflowers remains 45.9% of its original value within 6000 s, much higher than those of commercial Pt (36.7%) and Pd (32.2%) black catalysts. Therefore, PtPd nanoflowers with unique interconnected structures can be used as a promising cathode catalyst in direct methanol fuel cells

  9. Reduction redux.

    Science.gov (United States)

    Shapiro, Lawrence

    2018-04-01

    Putnam's criticisms of the identity theory attack a straw man. Fodor's criticisms of reduction attack a straw man. Properly interpreted, Nagel offered a conception of reduction that captures everything a physicalist could want. I update Nagel, introducing the idea of overlap, and show why multiple realization poses no challenge to reduction so construed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Intracellular synthesis of glutamic acid in Bacillus methylotrophicus SK19.001, a glutamate-independent poly(γ-glutamic acid)-producing strain.

    Science.gov (United States)

    Peng, Yingyun; Zhang, Tao; Mu, Wanmeng; Miao, Ming; Jiang, Bo

    2016-01-15

    Bacillus methylotrophicus SK19.001 is a glutamate-independent strain that produces poly(γ-glutamic acid) (γ-PGA), a polymer of D- and L-glutamic acids that possesses applications in food, the environment, agriculture, etc. This study was undertaken to explore the synthetic pathway of intracellular L- and D-glutamic acid in SK19.001 by investigating the effects of tricarboxylic acid cycle intermediates and different amino acids as metabolic precursors on the production of γ-PGA and analyzing the activities of the enzymes involved in the synthesis of L- and D-glutamate. Tricarboxylic acid cycle intermediates and amino acids could participate in the synthesis of γ-PGA via independent pathways in SK19.001. L-Aspartate aminotransferase, L-glutaminase and L-glutamate synthase were the enzymatic sources of L-glutamate. Glutamate racemase was responsible for the formation of D-glutamate for the synthesis of γ-PGA, and the synthetase had stereoselectivity for glutamate substrate. The enzymatic sources of L-glutamate were investigated for the first time in the glutamate-independent γ-PGA-producing strain, and multiple enzymatic sources of L-glutamate were verified in SK19.001, which will benefit efforts to improve production of γ-PGA with metabolic engineering strategies. © 2015 Society of Chemical Industry.

  11. Study of the oxidation-reduction kinetics involved in the Np(V) + Fe(II) in equilibrium Np(IV) + Fe(III) system in nitric acid solutions

    International Nuclear Information System (INIS)

    Jao, Y.

    1975-08-01

    Ferrous nitrate-hydrazine is one of the more attractive alternate reactants to the currently used reagent, ferrous sulfamate, for partitioning plutonium from neptunium and uranium. An understanding of the kinetics of the reduction of Np(VI) to Np(IV) by ferrous nitrate-hydrazine is needed before a satisfactory evaluation of the feasibility of this reductant in actinide element separations can be made. The purpose of this work was to study the kinetics and mechanisms of the reduction of Np(V) by Fe(II) and the oxidation of Np(IV) by Fe(III) in 1-2 M nitric acid solutions. The acid concentration range was chosen to include that typically used in the separation of plutonium from neptunium and uranium by solvent extraction with tributylphosphate. The forward and reverse rate constants, hydrogen ion dependence, temperature dependence, ionic strength effects and nitrate ion influence were determined. The proposed reaction mechanisms involve protonation of the NpO 2 + ions and hydroxyoxygenation of Np 4 + ions. (LK)

  12. Bio-inspired CO2 reduction by a rhenium tricarbonyl bipyridine-based catalyst appended to amino acids and peptidic platforms: incorporating proton relays and hydrogen-bonding functional groups.

    Science.gov (United States)

    Chabolla, S A; Machan, C W; Yin, J; Dellamary, E A; Sahu, S; Gianneschi, N C; Gilson, M K; Tezcan, F A; Kubiak, C P

    2017-06-02

    Herein, we report a new approach to bio-inspired catalyst design. The molecular catalyst employed in these studies is based on the robust and selective Re(bpy)(CO) 3 Cl-type (bpy = 2,2'-bipyridine) homogeneous catalysts, which have been extensively studied for their ability to reduce CO 2 electrochemically or photochemically in the presence of a photosensitizer. These catalysts can be highly active photocatalysts in their own right. In this work, the bipyridine ligand was modified with amino acids and synthetic peptides. These results build on earlier findings wherein the bipyridine ligand was functionalized with amide groups to promote dimer formation and CO 2 reduction by an alternate bimolecular mechanism at lower overpotential (ca. 250 mV) than the more commonly observed unimolecular process. The bio-inspired catalysts were designed to allow for the incorporation of proton relays to support reduction of CO 2 to CO and H 2 O. The coupling of amino acids tyrosine and phenylalanine led to the formation of two structurally similar Re catalyst/peptide catalysts for comparison of proton transport during catalysis. This article reports the synthesis and characterization of novel catalyst/peptide hybrids by molecular dynamics (MD simulations of structural dynamics), NMR studies of solution phase structures, and electrochemical studies to measure the activities of new bio-inspired catalysts in the reduction of CO 2.

  13. The isolation of [Pd{OC(O)H}(H)(NHC)(PR3)] (NHC = N-heterocyclic carbene) and its role in alkene and alkyne reductions using formic acid

    KAUST Repository

    Broggi, Julie

    2013-03-27

    The [Pd(SIPr)(PCy3)] complex efficiently promotes a tandem process involving dehydrogenation of formic acid and hydrogenation of C-C multiple bonds using H2 formed in situ. The isolation of a key catalytic hydridoformatopalladium species, [Pd{OC(O)H}(H)(IPr)(PCy 3)], is reported. The complex plays a key role in the Pd(0)-mediated formation of hydrogen from formic acid. Mechanistic and computational studies delineate the operational role of the palladium complex in this efficient tandem sequence. © 2013 American Chemical Society.

  14. The isolation of [Pd{OC(O)H}(H)(NHC)(PR3)] (NHC = N-heterocyclic carbene) and its role in alkene and alkyne reductions using formic acid

    KAUST Repository

    Broggi, Julie; Jurčí k, Vá clav; Songis, Olivier; Poater, Albert; Cavallo, Luigi; Slawin, Alexandra M. Z.; Cazin, Catherine S J

    2013-01-01

    The [Pd(SIPr)(PCy3)] complex efficiently promotes a tandem process involving dehydrogenation of formic acid and hydrogenation of C-C multiple bonds using H2 formed in situ. The isolation of a key catalytic hydridoformatopalladium species, [Pd{OC(O)H}(H)(IPr)(PCy 3)], is reported. The complex plays a key role in the Pd(0)-mediated formation of hydrogen from formic acid. Mechanistic and computational studies delineate the operational role of the palladium complex in this efficient tandem sequence. © 2013 American Chemical Society.

  15. Reduction of free fatty acids by acipimox enhances the growth hormone (GH) responses to GH-releasing peptide 2 in elderly men

    NARCIS (Netherlands)

    Smid, HEC; de Vries, WR; Niesink, M; Bolscher, E; Waasdorp, EJ; Dieguez, C; Casanueva, FF; Koppeschaar, HPF

    2000-01-01

    GH release is increased by reducing circulating free fatty acids (FFAs). Aging is associated with decreased plasma GH concentrations. We evaluated GH releasing capacity in nine healthy elderly men after administration of GH-releasing peptide 2 (GHRP-2), with or without pretreatment with the

  16. Salvianolic acid B, an antioxidant from Salvia miltiorrhiza, prevents A beta(25-35)-induced reduction in BPRP in PC12 cells

    NARCIS (Netherlands)

    Lin, Yan-Hua; Liu, Ai-Hua; Wu, Hong-Li; Westenbroek, Christel; Song, Qian-Liu; Yu, He-Ming; Ter Horst, Gert J.; Li, Xue-Jun; Li, Xiang-yi

    2006-01-01

    Several lines of evidence support that beta-amyloid (A beta)-induced neurotoxicity is mediated through the generation of reactive oxygen species (ROS) and elevation of intracellular calcium. Salvianolic acid B (Sal B), the major and most active anti-oxidant from Salvia miltiorrhiza. protects diverse

  17. Acid Blue dyes in polypyrrole synthesis: the control of polymer morphology at nanoscale in the promotion of high conductivity and the reduction of cytotoxicity

    Czech Academy of Sciences Publication Activity Database

    Bober, Patrycja; Li, Yu; Acharya, Udit; Panthi, Yadu Ram; Pfleger, Jiří; Humpolíček, P.; Trchová, Miroslava; Stejskal, Jaroslav

    2018-01-01

    Roč. 237, March (2018), s. 40-49 ISSN 0379-6779 R&D Projects: GA ČR(CZ) GA17-04109S Institutional support: RVO:61389013 Keywords : Acid Blue * conducting polymer * conductivity Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 2.435, year: 2016

  18. Impact of the oxygen defects and the hydrogen concentration on the surface of tetragonal and monoclinic ZrO2 on the reduction rates of stearic acid on Ni/ZrO2.

    Science.gov (United States)

    Foraita, Sebastian; Fulton, John L; Chase, Zizwe A; Vjunov, Aleksei; Xu, Pinghong; Baráth, Eszter; Camaioni, Donald M; Zhao, Chen; Lercher, Johannes A

    2015-02-02

    The role of the specific physicochemical properties of ZrO2 phases on Ni/ZrO2 has been explored with respect to the reduction of stearic acid. Conversion on pure m-ZrO2 is 1.3 times more active than on t-ZrO2 , whereas Ni/m-ZrO2 is three times more active than Ni/t-ZrO2 . Although the hydrodeoxygenation of stearic acid can be catalyzed solely by Ni, the synergistic interaction between Ni and the ZrO2 support causes the variations in the reaction rates. Adsorption of the carboxylic acid group on an oxygen vacancy of ZrO2 and the abstraction of the α-hydrogen atom with the elimination of the oxygen atom to produce a ketene is the key to enhance the overall rate. The hydrogenated intermediate 1-octadecanol is in turn decarbonylated to heptadecane with identical rates on all catalysts. Decarbonylation of 1-octadecanol is concluded to be limited by the competitive adsorption of reactants and intermediate. The substantially higher adsorption of propionic acid demonstrated by IR spectroscopy and the higher reactivity to O2 exchange reactions with the more active catalyst indicate that the higher concentration of active oxygen defects on m-ZrO2 compared to t-ZrO2 causes the higher activity of Ni/m-ZrO2 . © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Culture engineering examination and metabolism flux distribution system analysis for madding to convert into poly {beta}- hydroxybutyric acid (PHB) using the hydrogen bacteria of organic acid got in liquid-phase oxidation of lignite; Kattan no ekiso sanka de erareru yukisan wo suiso saikin wo riyoshite pori {beta}-hidorokishi rakusan(PHB) ni henkan saseru tameno baiyo kogakuteki kento to taisha ryusoku bunpu shisutemu kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, Kinko; Seki, Suito; Shimizu, Kazuyuki; Mae, Kazuhiro; Miura, Koichi

    1999-04-05

    The culture engineering examination for madding to convert into poly {beta} - hydroxy Wisteria (PHB) which glycolic acid. Acetic acid, ant acid, malonic acid got in liquid-phase oxidation of lignite are raw material of biodegradable plastic using hydrogen bacteria Alcaligenes eutrophus was carried out. It was proven that acetic acid was the most efficiently converted into the PHB as a result of cultivating these organic acid as a single carbon source. And, it was utilized to the bacterial cell at the order of ant acid, acetic acid, glycolic acid, when it was cultivated in mixing organic acid, and it was proven to convert into the PHB. Though the malonic acid was not utilized for the bacterial cell breeding, it was indicated that as the result which analyzed metabolism flow distribution by calculating using the culture data, the succinate dehydrogenase of the tricarboxylic acid (TCA) circuit received competitive inhibition, when this is added in culture middle point, and that the flux of griot lysyl acid route and gluconeogenesis route lowers. And, it was proven that it was utilized in the route which comes to the PHB synthesis from acetoacetyl CoA with the lowering of the ammonia concentration on NADPH produced from the isocitric acid, though it was prior consumed to the glutamic acid of tricarboxylic acid cycle in the route, if ammonia concentration is high. (translated by NEDO)

  20. On-line pre-reduction of pentavalent arsenicals by thioglycolic acid for speciation analysis by selective hydride generation-cryotrapping-atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Matoušek, Tomáš

    2008-01-01

    Roč. 63, č. 6 (2008), s. 685-691 ISSN 0584-8547 R&D Projects: GA AV ČR IAA400310507 Grant - others:NIH-FIRCA(US) 1 R03 TW007057-01 Institutional research plan: CEZ:AV0Z40310501 Keywords : HG-AAS * methylated arsenic species * on-line pre-reduction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.853, year: 2008

  1. Electroactivity of cobalt and nickel glyoximes with regard to the electro-reduction of protons into molecular hydrogen in acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Pantani, O.; Anxolabehere-Mallart, E.; Aukauloo, A. [Equipe de Chimie Inorganique, Institut de Chimie Moleculaire et des Materiaux d' Orsay, UMR 8182, Universite Paris Sud, bat 420, 91405 Orsay Cedex (France); Millet, P. [Equipe de Physico-Chimie de l' Etat Solide, Institut de Chimie Moleculaire et des Materiaux d' Orsay, UMR 8182, Universite Paris Sud, bat 420, 91405 Orsay Cedex (France)

    2007-01-15

    Water electrolysis is a key technological process for the production of hydrogen and the storage of intermittent and renewable energy sources. For domestic applications, the proton exchange membrane (PEM) process provides a safe and efficient way to split water into molecular hydrogen and oxygen but this technology, which requires platinum family electro-catalysts, remains too expensive. Molecular chemistry offers new opportunities for synthesizing alternative low-cost compounds, sufficiently stable in strong acidic media. In this paper, results obtained with different nickel and cobalt glyoximes are presented. They have been chemically (using UV-visible spectroscopy) and electrochemically (using cyclic voltammetry and spectro-electrochemistry) characterized. Their ability to electroreduce protons into molecular hydrogen from aqueous acidic solutions is discussed, the compounds being either dissolved in solution or immobilized at the surface of a solid electrode using recast Nafion{sup (R)} films in view of PEM applications. (author)

  2. Reduction of Inflammatory Responses and Enhancement of Extracellular Matrix Formation by Vanillin-Incorporated Poly(Lactic-co-Glycolic Acid) Scaffolds

    OpenAIRE

    Lee, Yujung; Kwon, Jeongil; Khang, Gilson; Lee, Dongwon

    2012-01-01

    Vanillin is one of the major components of vanilla, a commonly used flavoring agent and preservative and is known to exert potent antioxidant and anti-inflammatory activities. In this work, vanillin-incorporated poly(lactic-co-glycolic acid) (PLGA) films and scaffolds were fabricated to evaluate the effects of vanillin on the inflammatory responses and extracellular matrix (ECM) formation in vitro and in vivo. The incorporation of vanillin to PLGA films induced hydrophilic nature, resulting i...

  3. Intensive lifestyle intervention provides rapid reduction of serum fatty acid levels in women with severe obesity without lowering omega?3 to unhealthy levels?

    OpenAIRE

    Lin, C.; Andersen, J. R.; V?ge, V.; Rajalahti, T.; Mj?s, S. A.; Kvalheim, O. M.

    2016-01-01

    Summary Serum fatty acid (FA) levels were monitored in women with severe obesity during intensive lifestyle intervention. At baseline, total FA levels and most individual FAs were elevated compared to a matching cohort of normal and overweight women (healthy controls). After 3 weeks of intensive lifestyle intervention, total level was only 11?12% higher than in the healthy controls and with almost all FAs being significantly lower than at baseline, but with levels of omega?3 being similar to ...

  4. Aurintricarboxylic acid is a potent inhibitor of phosphofructokinase.

    Science.gov (United States)

    McCune, S A; Foe, L G; Kemp, R G; Jurin, R R

    1989-01-01

    Aurintricarboxylic acid (ATA) was found to be a very potent inhibitor of purified rabbit liver phosphofructokinase (PFK), giving 50% inhibition at 0.2 microM. The inhibition was in a manner consistent with interaction at the citrate-inhibitory site of the enzyme. The data suggest that inhibition of PFK by ATA was not due to denaturation of the enzyme or the irreversible binding of inhibitor, since the inhibition could be reversed by addition of allosteric activators of PFK, i.e. fructose 2,6-bisphosphate or AMP. Two other tricarboxylic acids, agaric acid and (-)-hydroxycitrate, were found to inhibit PFK. ATA at much higher concentrations (500 microM) was shown to inhibit fatty acid synthesis from endogenous glycogen in rat hepatocytes; however, protein synthesis was not altered. PMID:2525029

  5. Aldehydes, ketones, and carboxylic acids formed radiolytically in aqueous solutions of cyanides and simple nitriles

    International Nuclear Information System (INIS)

    Negron-Mendoza, A.; Draganic, Z.D.; Navarro-Gonzalez, R.; Graganic, I.G.

    1983-01-01

    A systematic search for aldehydes, ketones, and carboxylic acids was carried out in aqueous solutions of HCN, NH 4 CN, CH 3 CN, and C 2 H 4 CN, that had received multikilogray doses of 60 Co γ radiation. About 30 radiolytic products were identified, among them a large variety of dicarboxylic and tricarboxylic acids. Some of them might be of significant interest in molecular evolution studies of prebiotic processes. They originate in the free-radical-initiated chemical reactions where the additional oligomerization processes are particularly important. Most of the radiolytic products appear in both cyanides and nitriles and point to the importance of reactions involving the carbon-nitrogen triple bond

  6. The labeling of unsaturated γ-hydroxybutyric acid by heavy isotopes of hydrogen: iridium complex-mediated H/D exchange by C─H bond activation vs reduction by boro-deuterides/tritides.

    Science.gov (United States)

    Marek, Aleš; Pedersen, Martin H F; Vogensen, Stine B; Clausen, Rasmus P; Frølund, Bente; Elbert, Tomáš

    2016-10-01

    3-Hydroxycyclopent-1-ene-1-carboxylic acid (HOCPCA (1)) is a potent ligand for high-affinity γ-hydroxybutyric acid binding sites in the central nervous system. Various approaches to the introduction of a hydrogen label onto the HOCPCA skeleton are reported. The outcomes of the feasible C─H activation of olefin carbon (C-2) by iridium catalyst are compared with the reduction of the carbonyl group (C-3) by freshly prepared borodeuterides. The most efficient iridium catalysts proved to be Kerr bulky phosphine N-heterocyclic species providing outstanding deuterium enrichment (up to 91%) in a short period of time. The highest deuterium enrichment (>99%) was achieved through the reduction of ketone precursor 2 by lithium trimethoxyborodeuteride. Hence, analogical conditions were used for the tritiation experiment. [ 3 H]-HOCPCA selectively labeled on the position C-3 was synthetized with radiochemical purity >99%, an isolated yield of 637 mCi and specific activity = 28.9 Ci/mmol. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films

    Science.gov (United States)

    Hankins, Matthew G [Albuquerque, NM

    2009-10-06

    Etchant solutions comprising a redox buffer can be used during the release etch step to reduce damage to the structural layers of a MEMS device that has noble material films. A preferred redox buffer comprises a soluble thiophosphoric acid, ester, or salt that maintains the electrochemical potential of the etchant solution at a level that prevents oxidation of the structural material. Therefore, the redox buffer preferentially oxidizes in place of the structural material. The sacrificial redox buffer thereby protects the exposed structural layers while permitting the dissolution of sacrificial oxide layers during the release etch.

  8. Tolerance of citrus plants to the combination of high temperatures and drought is associated to the increase in transpiration modulated by a reduction in abscisic acid levels.

    Science.gov (United States)

    Zandalinas, Sara I; Rivero, Rosa M; Martínez, Vicente; Gómez-Cadenas, Aurelio; Arbona, Vicent

    2016-04-27

    In natural environments, several adverse environmental conditions occur simultaneously constituting a unique stress factor. In this work, physiological parameters and the hormonal regulation of Carrizo citrange and Cleopatra mandarin, two citrus genotypes, in response to the combined action of high temperatures and water deprivation were studied. The objective was to characterize particular responses to the stress combination. Experiments indicated that Carrizo citrange is more tolerant to the stress combination than Cleopatra mandarin. Furthermore, an experimental design spanning 24 h stress duration, heat stress applied alone induced higher stomatal conductance and transpiration in both genotypes whereas combined water deprivation partially counteracted this response. Comparing both genotypes, Carrizo citrange showed higher phostosystem-II efficiency and lower oxidative damage than Cleopatra mandarin. Hormonal profiling in leaves revealed that salicylic acid (SA) accumulated in response to individual stresses but to a higher extent in samples subjected to the combination of heat and drought (showing an additive response). SA accumulation correlated with the up-regulation of pathogenesis-related gene 2 (CsPR2), as a downstream response. On the contrary, abscisic acid (ABA) accumulation was higher in water-stressed plants followed by that observed in plants under stress combination. ABA signaling in these plants was confirmed by the expression of responsive to ABA-related gene 18 (CsRAB18). Modulation of ABA levels was likely carried out by the induction of 9-neoxanthin cis-epoxicarotenoid dioxygenase (CsNCED) and ABA 8'-hydroxylase (CsCYP707A) while conversion to ABA-glycosyl ester (ABAGE) was a less prominent process despite the strong induction of ABA O-glycosyl transferase (CsAOG). Cleopatra mandarin is more susceptible to the combination of high temperatures and water deprivation than Carrizo citrange. This is likely a result of a higher transpiration rate in

  9. Increased dissolved organic carbon (DOC) in Central European streams is driven by reductions in ionic strength rather than climate change or decreasing acidity.

    Science.gov (United States)

    Hruska, Jakub; Krám, Pavel; McDowell, William H; Oulehle, Filip

    2009-06-15

    Temporal trends in DOC concentration and flux were investigated at two geochemically distinct forested catchments in western Czech Republic. Mean discharge-weighted DOC concentrations averaged 18.8 mg L(-1) at the acidic Lysina catchment, and 20.2 mg L(-1) at base-rich and well-buffered Pluhuv Bor. Between 1993 and 2007 DOC in streamwater increased significantly in both catchments: the mean annual increase was 0.42 mg L(-1) yr(-1) (p DOC were correlated with only modest increases in stream pH in both catchments, but large declines in ionic strength (IS), that resulted from declining atmospheric deposition. Neither catchment has undergone changes in soil-water pH, yet DOC concentrations tripled in the soil-water of both catchments. We conclude that changes in ionic strength of soil-water and streamwater, rather than acidity, are the primary drivers of changes in streamwater DOC in this region. Temperature, precipitation and discharge show no statistically significant trends during the study period, suggesting that climate change has played no role in the changes in DOC that we have observed.

  10. Metabolic pathways regulated by abscisic acid, salicylic acid and γ-aminobutyric acid in association with improved drought tolerance in creeping bentgrass (Agrostis stolonifera).

    Science.gov (United States)

    Li, Zhou; Yu, Jingjin; Peng, Yan; Huang, Bingru

    2017-01-01

    Abscisic acid (ABA), salicylic acid (SA) and γ-aminobutyric acid (GABA) are known to play roles in regulating plant stress responses. This study was conducted to determine metabolites and associated pathways regulated by ABA, SA and GABA that could contribute to drought tolerance in creeping bentgrass (Agrostis stolonifera). Plants were foliar sprayed with ABA (5 μM), GABA (0.5 mM) and SA (10 μM) or water (untreated control) prior to 25 days drought stress in controlled growth chambers. Application of ABA, GABA or SA had similar positive effects on alleviating drought damages, as manifested by the maintenance of lower electrolyte leakage and greater relative water content in leaves of treated plants relative to the untreated control. Metabolic profiling showed that ABA, GABA and SA induced differential metabolic changes under drought stress. ABA mainly promoted the accumulation of organic acids associated with tricarboxylic acid cycle (aconitic acid, succinic acid, lactic acid and malic acid). SA strongly stimulated the accumulation of amino acids (proline, serine, threonine and alanine) and carbohydrates (glucose, mannose, fructose and cellobiose). GABA enhanced the accumulation of amino acids (GABA, glycine, valine, proline, 5-oxoproline, serine, threonine, aspartic acid and glutamic acid) and organic acids (malic acid, lactic acid, gluconic acid, malonic acid and ribonic acid). The enhanced drought tolerance could be mainly due to the enhanced respiration metabolism by ABA, amino acids and carbohydrates involved in osmotic adjustment (OA) and energy metabolism by SA, and amino acid metabolism related to OA and stress-defense secondary metabolism by GABA. © 2016 Scandinavian Plant Physiology Society.

  11. Analysis of aflatoxin M1 in milk and yogurt and AFM1 reduction by lactic acid bacteria used in Lebanese industry

    International Nuclear Information System (INIS)

    El Khoury, A.; Yaghi, J.; Atoui, A.

    2011-01-01

    In this study a screening survey was undertaken to determine the presence and levels of aflatoxin M1 (AFM1) in locally produced dairy products. For this purpose, a total of 138 dairy samples (milk and yogurt) were analyzed to quantify AFM1 levels in these products. Results obtained showed that AFM1 was found in 40.62% and 32.81% of milk and yogurt samples respectively. The range of contamination levels varied between lower and higher than European regulation limit. Lactic acid bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus) used in the Lebanese traditional industry were screened for their ability to reduce the level of AFM1. Due to the lack in data on the natural occurrence of AFM1 in Lebanese dairy products, the aim of this work was to report some information and to state these products according to EC regulations. (author)

  12. FY17-PDH-EVTest04 GodInput Impact of the Oxygen Defects1 FY17-PDH-EVTest04 Reduction Rates of Stearic AcidFY17-PDH-T04.

    Science.gov (United States)

    Foraita, Sebastian; Fulton, John L; Chase, Zizwe A; Vjunov, Aleksei; Xu, Pinghong; Baráth, Eszter; Camaioni, Donald M; Zhao, Chen; Lercher, Johannes A

    2016-08-10

    Test New Article1 GodEarlyview.Publish-on-load testing.The role of the specific physicochemical properties of ZrO 2 phases on Ni/ZrO 2 has been explored with respect to the reduction of stearic acid. Conversion on pure m?ZrO 2 is 1.3 times more active than on t?ZrO 2 , whereas Ni/m?ZrO 2 is three times more active than Ni/t?ZrO 2 . Although the hydrodeoxygenation of stearic acid can be catalyzed solely by Ni, the synergistic interaction between Ni and the ZrO 2 support causes the variations in the reaction rates. Adsorption of the carboxylic acid group on an oxygen vacancy of ZrO 2 and the abstraction of the ??hydrogen atom with the elimination of the oxygen atom to produce a ketene is the key to enhance the overall rate. The hydrogenated intermediate 1?octadecanol is in turn decarbonylated to heptadecane with identical rates on all catalysts. Decarbonylation of 1?octadecanol is concluded to be limited by the competitive adsorption of reactants and intermediate. The substantially higher adsorption of propionic acid demonstrated by IR spectroscopy and the higher reactivity to O 2 exchange reactions with the more active catalyst indicate that the higher concentration of active oxygen defects on m?ZrO 2 compared to t?ZrO 2 causes the higher activity of Ni/m?ZrO 2 . © 2015 WILEY?VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Microbial Production of Malic Acid from Biofuel-Related Coproducts and Biomass

    Directory of Open Access Journals (Sweden)

    Thomas P. West

    2017-04-01

    Full Text Available The dicarboxylic acid malic acid synthesized as part of the tricarboxylic acid cycle can be produced in excess by certain microorganisms. Although malic acid is produced industrially to a lesser extent than citric acid, malic acid has industrial applications in foods and pharmaceuticals as an acidulant among other uses. Only recently has the production of this organic acid from coproducts of industrial bioprocessing been investigated. It has been shown that malic acid can be synthesized by microbes from coproducts generated during biofuel production. More specifically, malic acid has been shown to be synthesized by species of the fungus Aspergillus on thin stillage, a coproduct from corn-based ethanol production, and on crude glycerol, a coproduct from biodiesel production. In addition, the fungus Ustilago trichophora has also been shown to produce malic acid from crude glycerol. With respect to bacteria, a strain of the thermophilic actinobacterium Thermobifida fusca has been shown to produce malic acid from cellulose and treated lignocellulosic biomass. An alternate method of producing malic acid is to use agricultural biomass converted to syngas or biooil as a substrate for fungal bioconversion. Production of poly(β-l-malic acid by strains of Aureobasidium pullulans from agricultural biomass has been reported where the polymalic acid is subsequently hydrolyzed to malic acid. This review examines applications of malic acid, metabolic pathways that synthesize malic acid and microbial malic acid production from biofuel-related coproducts, lignocellulosic biomass and poly(β-l-malic acid.

  14. Reduction of inflammatory responses and enhancement of extracellular matrix formation by vanillin-incorporated poly(lactic-co-glycolic acid) scaffolds.

    Science.gov (United States)

    Lee, Yujung; Kwon, Jeongil; Khang, Gilson; Lee, Dongwon

    2012-10-01

    Vanillin is one of the major components of vanilla, a commonly used flavoring agent and preservative and is known to exert potent antioxidant and anti-inflammatory activities. In this work, vanillin-incorporated poly(lactic-co-glycolic acid) (PLGA) films and scaffolds were fabricated to evaluate the effects of vanillin on the inflammatory responses and extracellular matrix (ECM) formation in vitro and in vivo. The incorporation of vanillin to PLGA films induced hydrophilic nature, resulting in the higher cell attachment and proliferation than the pure PLGA film. Vanillin also reduced the generation of reactive oxygen species (ROS) in cells cultured on the pure PLGA film and significantly inhibited the PLGA-induced inflammatory responses in vivo, evidenced by the reduced accumulation of inflammatory cells and thinner fibrous capsules. The effects of vanillin on the ECM formation were evaluated using annulus fibrous (AF) cell-seeded porous PLGA/vanillin scaffolds. PLGA/vanillin scaffolds elicited the more production of glycosaminoglycan and collagen than the pure PLGA scaffold, in a concentration-dependent manner. Based on the low level of inflammatory responses and enhanced ECM formation, vanillin-incorporated PLGA constructs make them promising candidates in the future biomedical applications.

  15. Reduction of Inflammatory Responses and Enhancement of Extracellular Matrix Formation by Vanillin-Incorporated Poly(Lactic-co-Glycolic Acid) Scaffolds

    Science.gov (United States)

    Lee, Yujung; Kwon, Jeongil; Khang, Gilson

    2012-01-01

    Vanillin is one of the major components of vanilla, a commonly used flavoring agent and preservative and is known to exert potent antioxidant and anti-inflammatory activities. In this work, vanillin-incorporated poly(lactic-co-glycolic acid) (PLGA) films and scaffolds were fabricated to evaluate the effects of vanillin on the inflammatory responses and extracellular matrix (ECM) formation in vitro and in vivo. The incorporation of vanillin to PLGA films induced hydrophilic nature, resulting in the higher cell attachment and proliferation than the pure PLGA film. Vanillin also reduced the generation of reactive oxygen species (ROS) in cells cultured on the pure PLGA film and significantly inhibited the PLGA-induced inflammatory responses in vivo, evidenced by the reduced accumulation of inflammatory cells and thinner fibrous capsules. The effects of vanillin on the ECM formation were evaluated using annulus fibrous (AF) cell-seeded porous PLGA/vanillin scaffolds. PLGA/vanillin scaffolds elicited the more production of glycosaminoglycan and collagen than the pure PLGA scaffold, in a concentration-dependent manner. Based on the low level of inflammatory responses and enhanced ECM formation, vanillin-incorporated PLGA constructs make them promising candidates in the future biomedical applications. PMID:22551555

  16. Keto analogues and amino acids supplementation induces a decrease of white blood cell counts and a reduction of muscle damage during intense exercise under thermoneutral conditions.

    Science.gov (United States)

    Lima, R C P; Camerino, S R A S; França, T C L; Rodrigues, D S A; Gouveia, M G S; Ximenes-da-Silva, A; Bassini, A; Prado, E S; Cameron, L C

    2017-04-19

    This study evaluated the acute effect of keto analogue and amino acid (AA-KAAA) supplementation on both white blood cell counts and the established biomarkers of muscle damage during exercise under thermoneutral conditions. Sixteen male cyclists received a ketogenic diet for two days and were divided into two equal groups: a group taking AA-KAAA (KA) or a control group (PL). The athletes performed a two hour cycling session followed by a maximum incremental test until voluntary exhaustion (VExh). Blood samples were obtained at rest and during exercise for further hematological and biochemical analyses. Exercise-induced ammonemia increased in the PL group at VExh (75%) but remained unchanged in the KA group. Both groups exhibited a significant increase in leukocyte and neutrophil counts of ∼85% (∼13 × 10 9 L -1 ), but the shape of the lymphocytes and the eosinophil counts suggest that AA-KAAA supplementation helps prevent lymphocytosis. AA-KAAA supplementation induced a decrease in creatine kinase and aspartate aminotransferase levels at VExh while showing a significant decrease in lactate dehydrogenase at 120 min. We found that AA-KAAA supplementation decreases both the lymphocyte count response in blood and the established biomarkers of muscle damage after intense exercise under a low heat stress environment.

  17. Poly-γ-Glutamic Acid Induces Apoptosis via Reduction of COX-2 Expression in TPA-Induced HT-29 Human Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Eun Ju Shin

    2015-04-01

    Full Text Available Poly-γ-glutamic acid (PGA is one of the bioactive compounds found in cheonggukjang, a fast-fermented soybean paste widely utilized in Korean cooking. PGA is reported to have a number of beneficial health effects, and interestingly, it has been identified as a possible anti-cancer compound through its ability to promote apoptosis in cancer cells, although the precise molecular mechanisms remain unclear. Our findings demonstrate that PGA inhibits the pro-proliferative functions of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA, a known chemical carcinogen in HT-29 human colorectal cancer cells. This inhibition was accompanied by hallmark apoptotic phenotypes, including DNA fragmentation and the cleavage of poly (ADP-ribose polymerase (PARP and caspase 3. In addition, PGA treatment reduced the expression of genes known to be overexpressed in colorectal cancer cells, including cyclooxygenase 2 (COX-2 and inducible nitric oxide synthase (iNOS. Lastly, PGA promoted activation of 5' adenosine monophosphate-activated protein (AMPK in HT-29 cells. Taken together, our results suggest that PGA treatment enhances apoptosis in colorectal cancer cells, in part by modulating the activity of the COX-2 and AMPK signaling pathways. These anti-cancer functions of PGA make it a promising compound for future study.

  18. Reduction corporoplasty.

    Science.gov (United States)

    Hakky, Tariq S; Martinez, Daniel; Yang, Christopher; Carrion, Rafael E

    2015-01-01

    Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism. Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement. The patient tolerated the procedure well and has resolution of his corporal disfigurement. Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement.

  19. Intra-articular injection of hyaluronic acid for the reduction in joint adhesion formation in a rabbit model of knee injury.

    Science.gov (United States)

    Wang, Min; Liu, Chao; Xiao, Wei

    2014-07-01

    Our purpose was to evaluate the effectiveness of intra-articular injections of hyaluronic acid (HA) into immobilized joints for reducing rigidity and formation of joint adhesions following surgery and prolonged joint immobilization. Twenty-four New Zealand white rabbits were randomly divided into experimental (n = 12) and control groups (n = 12). A model of knee injury was created in the right hind leg, and external plaster fixation was performed for 8 weeks. The experimental and control groups received weekly intra-articular injections of 0.3 mL HA solution or normal saline, respectively, in the knee joint. The degree of adhesions, range of motion (ROM), and collagen content of the synovium of the knee joint were observed after 8 weeks. At the end of 8 weeks, the experimental compared with control group had significantly higher mean ROM (70.3° ± 11.1° vs. 54.6° ± 11.2°, respectively; P = 0.002) and mean adhesion score. The experimental group compared with the control group had significantly lower mean adhesion score (2.2 ± 0.9 vs. 3.1 ± 0.7, respectively; P = 0.012) and collagen content (32.4 ± 4.7 vs. 39.0 ± 4.2 μg/mg, P = 0.001). In a rabbit model of knee injury, intra-articular injection of HA decreased adhesion formation and collagen content and increased ROM after prolonged immobilization. These results indicate that HA may be clinically useful to prevent adhesions and improve joint mobility in patients who require joint immobilization for up to 8 weeks.

  20. Superior reductions in hepatic steatosis and fibrosis with co-administration of a glucagon-like peptide-1 receptor agonist and obeticholic acid in mice.

    Science.gov (United States)

    Jouihan, Hani; Will, Sarah; Guionaud, Silvia; Boland, Michelle L; Oldham, Stephanie; Ravn, Peter; Celeste, Anthony; Trevaskis, James L

    2017-11-01

    Nonalcoholic steatohepatitis (NASH) is an unmet need associated with metabolic syndrome. There are no approved therapies for NASH; however, glucagon-like peptide-1 receptor (GLP-1R) and farnesoid-X receptor (FXR) agonists are promising drug targets. We investigated the therapeutic effects of co-administration of a GLP-1R agonist, IP118, with FXR agonist obeticholic acid (OCA) in mice. OCA and IP118 alone and in combination were sub-chronically administered to Lep ob /Lep ob mice with diet-induced NASH or diet-induced obese (DIO) mice. Metabolic (body weight and glucose) and liver (biochemical and histological) endpoints were assessed. NASH severity in Lep ob /Lep ob mice was graded using a customized integrated scoring system. OCA reduced liver weight and lipid in NASH mice (both by -17%) but had no effect on plasma ALT or AST levels. In contrast, IP118 significantly reduced liver weight (-21%), liver lipid (-15%), ALT (-29%), and AST (-27%). The combination of OCA + IP118 further reduced liver weight (-29%), liver lipid (-22%), ALT (-39%), and AST (-36%). Combination therapy was superior to monotherapies in reducing hepatic steatosis, inflammation, and fibrosis. Hepatic improvements with IP118 and OCA + IP118 were associated with reduced body weight (-4.3% and -3.5% respectively) and improved glycemic control in OCA + IP118-treated mice. In DIO mice, OCA + IP118 co-administration reduced body weight (-25.3%) to a greater degree than IP118 alone (-12.5%) and further improved glucose tolerance and reduced hepatic lipid. Our data suggest a complementary or synergistic therapeutic effect of GLP-1R and FXR agonism in mouse models of metabolic disease and NASH. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  1. Supplementation with antioxidant-rich extra virgin olive oil prevents hepatic oxidative stress and reduction of desaturation capacity in mice fed a high-fat diet: Effects on fatty acid composition in liver and extrahepatic tissues.

    Science.gov (United States)

    Rincón-Cervera, Miguel Angel; Valenzuela, Rodrigo; Hernandez-Rodas, María Catalina; Marambio, Macarena; Espinosa, Alejandra; Mayer, Susana; Romero, Nalda; Barrera M Sc, Cynthia; Valenzuela, Alfonso; Videla, Luis A

    2016-01-01

    The aim of this study was to assess the effect of dietary supplementation with extra virgin olive oil (EVOO) in mice on the reduction of desaturase and antioxidant enzymatic activities in liver, concomitantly with long-chain polyunsaturated fatty acids (LCPUFA) profiles in liver and extrahepatic tissues induced by a high-fat diet (HFD). Male mice C57 BL/6 J were fed with a control diet (CD; 10% fat, 20% protein, 70% carbohydrates) or an HFD (60% fat, 20% protein, 20% carbohydrates) for 12 wk. Animals were supplemented with 100 mg/d EVOO with different antioxidant contents (EVOO I, II, and III). After the intervention, blood and several tissues were analyzed. Dietary supplementation with EVOO with the highest antioxidant content and antioxidant capacity (EVOO III) significantly reduced fat accumulation in liver and the plasmatic metabolic alterations caused by HFD and produced a normalization of oxidative stress-related parameters, desaturase activities, and LCPUFA content in tissues. Data suggest that dietary supplementation with EVOO III may prevent oxidative stress and reduction of biosynthesis and accretion of ω-3 LCPUFA in the liver of HFD-fed mice. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Investigation on the effects of dietary protein reduction with constant ratio of digestible sulfur amino acids and threonine to lysine on performance, egg quality and protein retention in two strains of laying hens

    Directory of Open Access Journals (Sweden)

    Farhad Foroudi

    2013-01-01

    Full Text Available An experiment was conducted to determine the possibility of using various levels of crude protein (CP by providing laying hens with constant levels of digestible sulfur amino acid, threonine and lysine to improve performance and egg quality. The experiment was conducted as a completely randomized block design in a factorial arrangement (4 × 2 with 8 replicates of 10 hens in each. Factors included 4 levels of CP (18.5%, 17.5%, 16.5% and 15.5% and 2 strains (LSL and Hy-Line W-36 of laying hens. Hens were fed experimental diets from 25 to 33 weeks of age. Production performance was measured for eight weeks and egg quality characteristics were determined at 29 and 33 weeks of age. Protein reduction decreased egg weight, egg mass and hen body weight linearly (P≤0.01. Egg production was not affected by protein reduction but feed efficiency, and average daily feed intake increased significantly (P≤0.01. Lohmann Selected Leghorn laying hens showed significantly higher egg production, egg weight, egg mass, weight gain, feed efficiency and feed intake compared to the W-36 laying hens (P≤0.01. Shell thickness increased linearly as protein levels decreased (P≤0.05. There were significant differences between two strains on the egg quality characteristics (P≤0.01. Significant (P≤0.05 CP × strain interactions were observed for hen weight, albumen height, Haugh units, yolk and shell percentage. Based on the results of this experiment, a reduction in dietary protein level (from 18.5% to 15.5%, without any alteration in digestible TSAA and Thr: Lys ratio, led to inferior egg mass and feed conversion ratio during the peak production period.

  3. TiO{sub 2} modified with Ag nanoparticles synthesized via ultrasonic atomization-UV reduction and the use of kinetic models to determine the acetic acid photocatalytic degradation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yingcao, E-mail: xuyingcao@aliyun.com [State Key Laboratory of Urban Water Resource, Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China); Applied Chemistry Department, School of Science, Northeast Agriculture University, Harbin 150030 (China); You, Hong, E-mail: youhong@hit.edu.cn [State Key Laboratory of Urban Water Resource, Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2014-12-01

    Highlights: • The first use of ultrasonic atomization-UV reduction for modifying Ag on TiO{sub 2}. • The first use of kinetics models for the establishment of the photocatalytic degradation of acetic acid using a hyperbolic mathematical model and introducing the concentration factor (α) in the dynamic model. • Photocatalytic experiment design using double-sided TiO{sub 2} and a double-light source. - Abstract: TiO{sub 2} surfaces modified with noble metal nanoparticles have been found to effectively reduce the photogenerated carrier recombination rate and significantly extend the light absorption properties of TiO{sub 2}, thereby greatly increasing its photocatalytic activity. In this paper, highly ordered, double-sided TiO{sub 2} nanotube arrays were prepared using an anodic oxidation method in a home-made reactor using glycerol/water (volume ratio 2:1) and NH{sub 4}F (0.25 mol/L) as the electrolyte, titanium plates (10 cm × 2 cm × 0.5 mm) as the anode and graphite as the cathode at a constant voltage of 25 V. After a 2-h reaction, anatase TiO{sub 2} nanotubes were obtained upon calcination at 450 °C for 4 h. The Ag nanoparticles on the surfaces of the TiO{sub 2} were prepared via ultrasonic atomization-ultraviolet light reduction. First, a silver nitrate solution was sputtered into small droplets under ultrasonication. Then, the Ag{sup +} droplets were reduced to Ag nanoparticles. The surface morphologies, structures and elemental compositions were characterized using SEM, EDS, XRD and XPS. The photocatalytic activities were determined in acetic acid solutions (40–200 mg/L), and a mathematical model for catalytic degradation was established based on a hyperbolic model. The SEM results showed that the diameters of the as-prepared Ag/TiO{sub 2} are approximately 100 nm and that the lengths are approximately 1.8 μm. The XRD crystal structure analysis shows that the anatase phase of the TiO{sub 2} does not change during the Ag modification, and there was

  4. Reduction Corporoplasty

    Directory of Open Access Journals (Sweden)

    Tariq S. Hakky

    2015-04-01

    Full Text Available Objective Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism. Introduction Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. Materials and Methods: We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement. Results The patient tolerated the procedure well and has resolution of his corporal disfigurement. Conclusions Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement.

  5. Study of HKUST (Copper benzene-1,3,5-tricarboxylate, Cu-BTC MOF)-1 metal organic frameworks for CH4 adsorption: An experimental Investigation with GCMC (grand canonical Monte-carlo) simulation

    International Nuclear Information System (INIS)

    Sun, Baichuan; Kayal, Sibnath; Chakraborty, Anutosh

    2014-01-01

    We have measured the methane uptakes on HKUST (Copper benzene-1,3,5-tricarboxylate, Cu-BTC MOF)-1 MOF (metal organic framework) for the temperatures ranging from 120 K to 300 K and pressures up to 10 bar. The experimentally measured HKUST-1 + CH 4 isotherms data are compared with uptakes of various adsorbents and methane systems. We have also simulated the methane uptakes and its density distribution on HKUST-1 employing GCMC (grand canonical Monte-carlo) simulation and compare with experimental data. In this article, we also present an extensive study on characterization and property evaluation of HKUST-1 MOF for CH 4 adsorption characteristics employing XRD (X-ray diffraction), SEM (scanning electron microscope) and TGA (thermo gravimetric analysis). Employing GCMC and the thermodynamic property fields of HKUST-1 + CH 4 system, the isosteric heat of adsorption (Q st ) is calculated and Q st is presented in a T-s (temperature-entropy) diagram. - Highlights: • Characterization of HKUST-1 MOFs by XRD, SEM, N 2 adsorption and TGA. • Measurement of CH 4 uptakes on HKUST-1 by volumetric methods. • GCMC simulation of methane uptakes and its density distribution on HKUST-1. • Isosteric heat of adsorption in a T-s (temperature-entropy) diagram

  6. Thermochemical nitrate reduction

    International Nuclear Information System (INIS)

    Cox, J.L.; Lilga, M.A.; Hallen, R.T.

    1992-09-01

    A series of preliminary experiments was conducted directed at thermochemically converting nitrate to nitrogen and water. Nitrates are a major constituent of the waste stored in the underground tanks on the Hanford Site, and the characteristics and effects of nitrate compounds on stabilization techniques must be considered before permanent disposal operations begin. For the thermochemical reduction experiments, six reducing agents (ammonia, formate, urea, glucose, methane, and hydrogen) were mixed separately with ∼3 wt% NO 3 - solutions in a buffered aqueous solution at high pH (13); ammonia and formate were also mixed at low pH (4). Reactions were conducted in an aqueous solution in a batch reactor at temperatures of 200 degrees C to 350 degrees C and pressures of 600 to 2800 psig. Both gas and liquid samples were analyzed. The specific components analyzed were nitrate, nitrite, nitrous oxide, nitrogen, and ammonia. Results of experimental runs showed the following order of nitrate reduction of the six reducing agents in basic solution: formate > glucose > urea > hydrogen > ammonia ∼ methane. Airnmonia was more effective under acidic conditions than basic conditions. Formate was also effective under acidic conditions. A more thorough, fundamental study appears warranted to provide additional data on the mechanism of nitrate reduction. Furthermore, an expanded data base and engineering feasibility study could be used to evaluate conversion conditions for promising reducing agents in more detail and identify new reducing agents with improved performance characteristics

  7. Snubber reduction

    International Nuclear Information System (INIS)

    Olson, D.E.; Singh, A.K.

    1986-01-01

    Many safety-related piping systems in nuclear power plants have been oversupported. Since snubbers make up a large percentage of the pipe supports or restraints used in a plant, a plant's snubber population is much larger than required to adequately restrain the piping. This has resulted in operating problems and unnecessary expenses for maintenance and inservice inspections (ISIs) of snubbers. This paper presents an overview of snubber reduction, including: the incentives for removing snubbers, a historical perspective on how piping became oversupported, why it is possible to remove snubbers, and the costs and benefits of doing so

  8. Americium recovery from reduction residues

    Science.gov (United States)

    Conner, W.V.; Proctor, S.G.

    1973-12-25

    A process for separation and recovery of americium values from container or bomb'' reduction residues comprising dissolving the residues in a suitable acid, adjusting the hydrogen ion concentration to a desired level by adding a base, precipitating the americium as americium oxalate by adding oxalic acid, digesting the solution, separating the precipitate, and thereafter calcining the americium oxalate precipitate to form americium oxide. (Official Gazette)

  9. Synthesis and characterization of PdAg as a catalyst for oxygen reduction reaction in acid medium; Sintesis y caracterizacion de PdAg como catalizador para la reaccion de reduccion de oxigeno en medio acido

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Casillas, D. C.; Vazquez-Huerta, G.; Solorza-Feria, O. [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)]. E-mail: dcmartinez@cinvestav.mx

    2009-09-15

    This work presents the synthesis of the binary compound PdAg and the electrochemical characterization for oxygen reduction reaction (ORR) in acid medium. The catalyst is obtained from the reduction of Pd(NO{sub 3}){sub 2}·2H{sub 2}O and AgNO{sub 3} with NaBH{sub 4} in THF. The synthesized compound was physically characterized with transmission electron microscopy (TEM), sweep electron microscopy (SEM) and x-ray diffraction (XRD) of powder. Electrochemical studies were conducted to determine the catalytic activity and intrinsic properties of the PdAg material for the ORR in acid medium using cyclic voltamperometry (CV), rotary disc electrode (RDE) and electrochemical impedance spectroscopy (EIS) in a solution of H{sub 2}SO{sub 4} 0.5 M at 25 degrees Celsius. The electrochemical current-potential responses were compared to those of palladium and platinum. The kinetic results showed an increase in the performance of the bimetallic electrocatalyst containing Ag as compared to pure Pd, but less than that obtained with nanometric Pt. The Tafel slopes obtained are roughly120 mV dec-1, similar to that reported for Pt and Pd and for other Ru-based electrocatalysts. [Spanish] En este trabajo se presentan la sintesis del compuesto binario PdAg y su caracterizacion electroquimica para la reaccion de reduccion de oxigeno (RRO) en medio acido. El catalizador se obtuvo a partir de la reduccion de Pd(NO{sub 3}){sub 2}·2H{sub 2}O y AgNO{sub 3} con NaBH{sub 4} en THF. El compuesto sintetizado se caracterizo fisicamente por microscopia electronica de transmision (MET), microscopia electronica de barrido (MEB) y difraccion de rayos X (DRX) de polvos. Se realizaron estudios electroquimicos para determinar la actividad catalitica y las propiedades intrinsecas del material de PdAg para la reaccion de reduccion de oxigeno (RRO) en medio acido, utilizando las tecnicas de voltamperometria ciclica (VC), electrodo disco rotatorio (EDR) y espectroscopia de impedancia electroquimica (EIE), en

  10. Radon reduction

    International Nuclear Information System (INIS)

    Hamilton, M.A.

    1990-01-01

    During a radon gas screening program, elevated levels of radon gas were detected in homes on Mackinac Island, Mich. Six homes on foundations with crawl spaces were selected for a research project aimed at reducing radon gas concentrations, which ranged from 12.9 to 82.3 pCi/l. Using isolation and ventilation techniques, and variations thereof, radon concentrations were reduced to less than 1 pCi/l. This paper reports that these reductions were achieved using 3.5 mil cross laminated or 10 mil high density polyethylene plastic as a barrier without sealing to the foundation or support piers, solid and/or perforated plastic pipe and mechanical fans. Wind turbines were found to be ineffective at reducing concentrations to acceptable levels. Homeowners themselves installed all materials

  11. Aspartate protects Lactobacillus casei against acid stress.

    Science.gov (United States)

    Wu, Chongde; Zhang, Juan; Du, Guocheng; Chen, Jian

    2013-05-01

    The aim of this study was to investigate the effect of aspartate on the acid tolerance of L. casei. Acid stress induced the accumulation of intracellular aspartate in L. casei, and the acid-resistant mutant exhibited 32.5 % higher amount of aspartate than that of the parental strain at pH 4.3. Exogenous aspartate improved the growth performance and acid tolerance of Lactobacillus casei during acid stress. When cultivated in the presence of 50 mM aspartate, the biomass of cells increased 65.8 % compared with the control (without aspartate addition). In addition, cells grown at pH 4.3 with aspartate addition were challenged at pH 3.3 for 3 h, and the survival rate increased 42.26-fold. Analysis of the physiological data showed that the aspartate-supplemented cells exhibited higher intracellular pH (pHi), intracellular NH4 (+) content, H(+)-ATPase activity, and intracellular ATP pool. In addition, higher contents of intermediates involved in glycolysis and tricarboxylic acid cycle were observed in cells in the presence of aspartate. The increased contents of many amino acids including aspartate, arginine, leucine, isoleucine, and valine in aspartate-added cells may contribute to the regulation of pHi. Transcriptional analysis showed that the expression of argG and argH increased during acid stress, and the addition of aspartate induced 1.46- and 3.06-fold higher expressions of argG and argH, respectively, compared with the control. Results presented in this manuscript suggested that aspartate may protect L. casei against acid stress, and it may be used as a potential protectant during the production of probiotics.

  12. Adaptation to a high protein, carbohydrate-free diet induces a marked reduction of fatty acid synthesis and lipogenic enzymes in rat adipose tissue that is rapidly reverted by a balanced diet.

    Science.gov (United States)

    Brito, S M R C; Moura, M A F; Kawashita, N H; Festuccia, W T L; Garófalo, M A R; Kettelhut, I C; Migliorini, R H

    2005-06-01

    We have previously shown that in vivo lipogenesis is markedly reduced in liver, carcass, and in 4 different depots of adipose tissue of rats adapted to a high protein, carbohydrate-free (HP) diet. In the present work, we investigate the activity of enzymes involved in lipogenesis in the epididymal adipose tissue (EPI) of rats adapted to an HP diet before and 12 h after a balanced diet was introduced. Rats fed an HP diet for 15 days showed a 60% reduction of EPI fatty acid synthesis in vivo that was accompanied by 45%-55% decreases in the activities of pyruvate dehydrogenase complex, ATP-citrate lyase, acetyl-CoA carboxylase, glucose-6-phosphate dehydrogenase, and malic enzyme. Reversion to a balanced diet for 12 h resulted in a normalization of in vivo EPI lipogenesis, and in a restoration of acetyl-CoA carboxylase activity to levels that did not differ significantly from control values. The activities of ATP-citrate lyase and pyruvate dehydrogenase complex increased to about 75%-86% of control values, but the activities of glucose-6-phosphate dehydrogenase and malic enzyme remained unchanged 12 h after diet reversion. The data indicate that in rats, the adjustment of adipose tissue lipogenic activity is an important component of the metabolic adaptation to different nutritional conditions.

  13. Biochemistry of Catabolic Reductive Dehalogenation.

    Science.gov (United States)

    Fincker, Maeva; Spormann, Alfred M

    2017-06-20

    A wide range of phylogenetically diverse microorganisms couple the reductive dehalogenation of organohalides to energy conservation. Key enzymes of such anaerobic catabolic pathways are corrinoid and Fe-S cluster-containing, membrane-associated reductive dehalogenases. These enzymes catalyze the reductive elimination of a halide and constitute the terminal reductases of a short electron transfer chain. Enzymatic and physiological studies revealed the existence of quinone-dependent and quinone-independent reductive dehalogenases that are distinguishable at the amino acid sequence level, implying different modes of energy conservation in the respective microorganisms. In this review, we summarize current knowledge about catabolic reductive dehalogenases and the electron transfer chain they are part of. We review reaction mechanisms and the role of the corrinoid and Fe-S cluster cofactors and discuss physiological implications.

  14. Synthesis of Nickel (Ni) Doped HKUST-1 Using Solvotermal Method with Addition of Acetic Acid as Modulator

    OpenAIRE

    Safii, Farhan Fikri; Ediati, Ratna

    2015-01-01

    Hong Kong University of Science and Technology-1 (HKUST-1) is metal organic framework (MOF) that composed from ligand BTC (1,3,5-benzene tricarboxylic) and copper ions. The method used in this study is solvotermal with variations nickel ion doping and additions acetic acid as modulator. The purpose of this study is to increase the hydrogen storage capacity. The results obtained were characterized by XRD showed that the HKUST-1 and Ni-HKUST-1 has formed, showed by peaks at 2 theta = 6.7, 9.5, ...

  15. The effects of monovalent and divalent cations on the stability of silver nanoparticles formed from direct reduction of silver ions by Suwannee River humic acid/natural organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Akaighe, Nelson [Chemistry Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 (United States); Depner, Sean W.; Banerjee, Sarbajit [Department of Chemistry, 410 Natural Sciences Complex, University at Buffalo, The State University of New York, Buffalo, NY 14260-3000 (United States); Sharma, Virender K. [Chemistry Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 (United States); Sohn, Mary, E-mail: msohn@fit.edu [Chemistry Department, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901 (United States)

    2012-12-15

    The formation and characterization of AgNPs (silver nanoparticles) formed from the reduction of Ag{sup +} by SRNOM (Suwannee River natural organic matter) is reported. The images of SRNOM-formed AgNPs and the selected area electron diffraction (SAED) were captured by high resolution transmission electron microscopy (HRTEM). The colloidal and chemical stability of SRNOM- and SRHA (Suwannee River humic acid)-formed AgNPs in different ionic strength solutions of NaCl, KCl, CaCl{sub 2} and MgCl{sub 2} was investigated in an effort to evaluate the key fate and transport processes of these nanoparticles in natural aqueous environments. The aggregation state, stability and sedimentation rate of the AgNPs were monitored by Dynamic Light Scattering (DLS), zeta potential, and UV-vis measurements. The results indicate that both types of AgNPs are very unstable in high ionic strength solutions. Interestingly, the nanoparticles appeared more unstable in divalent cation solutions than in monovalent cation solutions at similar concentrations. Furthermore, the presence of SRNOM and SRHA contributed to the nanoparticle instability at high ionic strength in divalent metallic cation solutions, most likely due to intermolecular bridging with the organic matter. The results clearly suggest that changes in solution chemistry greatly affect nanoparticle long term stability and transport in natural aqueous environments. Highlights: Black-Right-Pointing-Pointer Formation of SRNOM-AgNPs under environmentally relevant conditions Black-Right-Pointing-Pointer Influence of monovalent versus divalent cations on SRHA- and SRNOM-AgNP stability Black-Right-Pointing-Pointer Effect of AgNPs on organic matter removal from water columns.

  16. Health economic potential of early nutrition programming: a model calculation of long-term reduction in blood pressure and related morbidity costs by use of long-chain polyunsaturated fatty acid-supplemented formula.

    Science.gov (United States)

    Straub, Niels; Grunert, Philipp; von Kries, Rüdiger; Koletzko, Berthold

    2011-12-01

    The reported effect sizes of early nutrition programming on long-term health outcomes are often small, and it has been questioned whether early interventions would be worthwhile in enhancing public health. We explored the possible health economic consequences of early nutrition programming by performing a model calculation, based on the only published study currently available for analysis, to evaluate the effects of supplementing infant formula with long-chain polyunsaturated fatty acids (LC-PUFAs) on lowering blood pressure and lowering the risk of hypertension-related diseases in later life. The costs and health effects of LC-PUFA-enriched and standard infant formulas were compared by using a Markov model, including all relevant direct and indirect costs based on German statistics. We assessed the effect size of blood pressure reduction from LC-PUFA-supplemented formula, the long-term persistence of the effect, and the effect of lowered blood pressure on hypertension-related morbidity. The cost-effectiveness analysis showed an increased life expectancy of 1.2 quality-adjusted life-years and an incremental cost-effectiveness ratio of -630 Euros (discounted to present value) for the LC-PUFA formula in comparison with standard formula. LC-PUFA nutrition was the superior strategy even when the blood pressure-lowering effect was reduced to the lower 95% CI. Breastfeeding is the recommended feeding practice, but infants who are not breastfed should receive an appropriate infant formula. Following this model calculation, LC-PUFA supplementation of infant formula represents an economically worthwhile prevention strategy, based on the costs derived from hypertension-linked diseases in later life. However, because our analysis was based on a single randomized controlled trial, further studies are required to verify the validity of this thesis.

  17. Reduction of Exudates (Browning) in Sugarcane Micro Propagation ...

    African Journals Online (AJOL)

    ... of this variety, ascorbic acid and citric acid was added as constituent of the media using MS and stock at different concentrations. The browning was reduced drastically at the addition of 0.1g/litre ascorbic acid and 0.15g/litre citric acid. Keywords: reduction, exudates browning, micro propagation, sugarcane. Nig J. Biotech.

  18. Process for the reduction of nitrogen oxides in an effluent

    Energy Technology Data Exchange (ETDEWEB)

    Epperly, W.R.; Sullivan, J.C.; Sprague, B.N.

    1989-07-04

    This patent describes a process for the reduction of the concentration of nitrogen oxides in the effluent from the combustion of a carbonaceous fuel. The process comprises introducing a treatment agent which comprises a composition selected from the group consisting of NH/sub 4/-lignosulfonate, calcium lignosulfonate, 2-furoic acid, 1,3 dioxolane, tetrahydrofuran, furfurylamine, furfurylalcohol, gluconic acid, citric acid, n-butyl acetate, 1,3 butylene glycol, methylal, tetrahydrofuryl alcohol, furan, fish oil, coumalic acid, furfuryl acetate, tetrahydrofuran 2,3,4,5-tetracarboxylic acid, tetrahydrofurylamine, furylacrylic acid, tetrahydropyran, 2,5-furandimethanol, mannitol, hexamethylenediamine, barbituric acid, acetic anhydride, oxalic acid, mucic acid and d-galactose.

  19. The Mitotic and Metabolic Effects of Phosphatidic Acid in the Primary Muscle Cells of Turbot (Scophthalmus maximus

    Directory of Open Access Journals (Sweden)

    Tingting Wang

    2018-05-01

    Full Text Available Searching for nutraceuticals and understanding the underlying mechanism that promote fish growth is at high demand for aquaculture industry. In this study, the modulatory effects of soy phosphatidic acids (PA on cell proliferation, nutrient sensing, and metabolic pathways were systematically examined in primary muscle cells of turbot (Scophthalmus maximus. PA was found to stimulate cell proliferation and promote G1/S phase transition through activation of target of rapamycin signaling pathway. The expression of myogenic regulatory factors, including myoD and follistatin, was upregulated, while that of myogenin and myostatin was downregulated by PA. Furthermore, PA increased intracellular free amino acid levels and enhanced protein synthesis, lipogenesis, and glycolysis, while suppressed amino acid degradation and lipolysis. PA also was found to increased cellular energy production through stimulated tricarboxylic acid cycle and oxidative phosphorylation. Our results identified PA as a potential nutraceutical that stimulates muscle cell proliferation and anabolism in fish.

  20. The labeling of unsaturated γ-hydroxybutyric acid by heavy isotopes of hydrogen: iridium complex-mediated H/D exchange by C─H bond activation vs reduction by boro-deuterides/tritides

    DEFF Research Database (Denmark)

    Marek, Ales; Pedersen, Martin Holst Friborg; Vogensen, Stine B.

    2016-01-01

    3-Hydroxycyclopent-1-ene-1-carboxylic acid (HOCPCA ( 1 )) is a potent ligand for high-affinity γ-hydroxybutyric acid binding sites in the central nervous system. Various approaches to the introduction of a hydrogen label onto the HOCPCA skeleton are reported. The outcomes of the feasible C...

  1. Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.

    Science.gov (United States)

    Andrés-Barrao, Cristina; Saad, Maged M; Chappuis, Marie-Louise; Boffa, Mauro; Perret, Xavier; Ortega Pérez, Ruben; Barja, François

    2012-03-16

    Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane. However, except for a few acetate-specific proteins, little is known about the global proteome responses to AcH. In this study, we used 2D-DIGE to compare the proteome of Acetobacter pasteurianus LMG 1262(T) when growing in glucose or ethanol and in the presence of acetic acid. Interesting protein spots were selected using the ANOVA p-value of 0.05 as threshold and 1.5-fold as the minimal level of differential expression, and a total of 53 proteins were successfully identified. Additionally, the size of AAB was reduced by approximately 30% in length as a consequence of the acidity. A modification in the membrane polysaccharides was also revealed by PATAg specific staining. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Finding optimal exact reducts

    KAUST Repository

    AbouEisha, Hassan M.

    2014-01-01

    The problem of attribute reduction is an important problem related to feature selection and knowledge discovery. The problem of finding reducts with minimum cardinality is NP-hard. This paper suggests a new algorithm for finding exact reducts

  3. "Click" synthesis of fatty acid derivatives as fast-degrading polyanhydride precursors.

    Science.gov (United States)

    Lluch, Cristina; Lligadas, Gerard; Ronda, Joan C; Galià, Marina; Cadiz, Virginia

    2011-09-01

    Fast-degrading linear and branched polyanhydrides are obtained by melt-condensation of novel di- and tri-carboxylic acid monomers based on oleic and undecylenic acid synthesized using photoinitiated thiol-ene click chemistry. (1)H NMR spectroscopy, size exclusion chromatography, differential scanning calorimetry, thermogravimetric analysis, and FT-IR spectroscopy have been used to fully characterize these polymers. The hydrolytic degradation of these polymers was studied by means of weight loss, anhydride bond loss, and changes in molecular weight, showing fast degrading properties. Drug release studies from the synthesized polyanhydrides have also been conducted, using rhodamine B as a hydrophobic model drug, to evaluate the potential of these polymers in biomedical applications. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Breast Reduction Surgery

    Science.gov (United States)

    ... considering breast reduction surgery, consult a board-certified plastic surgeon. It's important to understand what breast reduction surgery entails — including possible risks and complications — as ...

  5. S.1234: A bill to amend the Internal Revenue Code of 1986 to provide tax relief to utilities installing acid rain reduction equipment, introduced in the Senate of the United States, One Hundred Second Congress, First Session, June 6, 1991

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The bill would allow a tax credit of 6 2/3% of a taxpayer's investment in qualified acid rain control equipment for each of the three years beginning the year the equipment is placed in service. Additionally, a tax credit would be allowed during two years of construction progress, the amount being 6 2/3% of construction expenditures. The bill describes qualified acid rain property', tax-exempt financing of acid rain control property, tax credit for minerals used to reduce the sulfur in coal, coal cleaning minerals credit, exclusion from gross income of receipt of qualified Clean Air allowance and proceeds of disposition thereof, qualified Clean Air allowances, and amortization of acid rain control property

  6. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2014. Scientific Opinion on the evaluation of the safety and efficacy of peroxyacetic acid solutions for reduction of pathogens on poultry carcasses and meat

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    no concerns for environmental risk of peroxyacids, acetic acid and octanoic acid. On the basis of a conservative preliminary guideline for surface water quality, the emission of HEDP from a poultry plant into the environment could not be considered safe a priori. It was recommended that HACCP plans should...... include monitoring of the concentration of HEDP and of the decontaminating substance in the working solution and post-marketing surveillance for resistance in both pathogenic and commensal bacteria....

  7. Infinitary Combinatory Reduction Systems: Normalising Reduction Strategies

    NARCIS (Netherlands)

    Ketema, J.; Simonsen, Jakob Grue

    2010-01-01

    We study normalising reduction strategies for infinitary Combinatory Reduction Systems (iCRSs). We prove that all fair, outermost-fair, and needed-fair strategies are normalising for orthogonal, fully-extended iCRSs. These facts properly generalise a number of results on normalising strategies in

  8. Photochemical reduction of uranyl nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Duerksen, W.K.

    1993-10-20

    The photochemical reduction of uranyl nitrate solutions to tetravalent uranium was investigated as a means of producing uranium dioxide feed for the saltless direct oxide reduction (SDOR) process. At high uranium concentrations, reoxidation of U{sup +4} occurs rapidly. The kinetics of the nitric oxidation of tetravalent uranium depend on the concentrations of hydrogen ion, nitrate ion, nitrous acid, and tetravalent uranium in the same manner as was reported elsewhere for the nitrate oxidation of PU{sup +3}. Reaction rate data were successfully correlated with a mechanism in which nitrogen dioxide is the reactive intermediate. Addition of a nitrous acid scavenger suppresses the reoxidation reaction. An immersion reactor employing a mercury vapor lamp gave reduction times fast enough for routine production usage. Precipitation techniques for conversion of aqueous U(NO{sub 3}){sub 4} to hydrous UO{sub 2} were evaluated. Prolonged dewatering times tended to make the process time consuming. Use of 3- to 4-M aqueous NaOH gave the best dewatering times observed. Reoxidation of the UO{sub 2} by water of hydration was encountered, which required the drying process to be carried out under a reducing atmosphere.

  9. Wet SiO2 As a Suitable Media for Fast and Efficient Reduction of Carbonyl Compounds with NaBH3CN under Solvent-Free and Acid-Free Conditions

    International Nuclear Information System (INIS)

    Kouhkan, Mehri; Zeynizadeh, Behzad

    2010-01-01

    Reduction of carbonyl compounds such as aldehydes, ketones, α,β-unsaturated enals and enones, α-diketones and acyloins was carried out readily with NaBH 3 CN in the presence of wet SiO 2 as a neutral media. The reactions were performed at solvent-free conditions in oil bath (70 - 80 .deg. C) or under microwave irradiation (240 W) to give the product alcohols in high to excellent yields. Regioselective 1,2-reduction of conjugated carbonyl compounds took place in a perfect selectivity without any side product formation

  10. Wet SiO{sub 2} As a Suitable Media for Fast and Efficient Reduction of Carbonyl Compounds with NaBH{sub 3}CN under Solvent-Free and Acid-Free Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kouhkan, Mehri; Zeynizadeh, Behzad [Urmia University, Urmia (Iran, Islamic Republic of)

    2010-10-15

    Reduction of carbonyl compounds such as aldehydes, ketones, α,β-unsaturated enals and enones, α-diketones and acyloins was carried out readily with NaBH{sub 3}CN in the presence of wet SiO{sub 2} as a neutral media. The reactions were performed at solvent-free conditions in oil bath (70 - 80 .deg. C) or under microwave irradiation (240 W) to give the product alcohols in high to excellent yields. Regioselective 1,2-reduction of conjugated carbonyl compounds took place in a perfect selectivity without any side product formation.

  11. A metabolic switch in brain: glucose and lactate metabolism modulation by ascorbic acid.

    Science.gov (United States)

    Castro, Maite A; Beltrán, Felipe A; Brauchi, Sebastián; Concha, Ilona I

    2009-07-01

    In this review, we discuss a novel function of ascorbic acid in brain energetics. It has been proposed that during glutamatergic synaptic activity neurons preferably consume lactate released from glia. The key to this energetic coupling is the metabolic activation that occurs in astrocytes by glutamate and an increase in extracellular [K(+)]. Neurons are cells well equipped to consume glucose because they express glucose transporters and glycolytic and tricarboxylic acid cycle enzymes. Moreover, neuronal cells express monocarboxylate transporters and lactate dehydrogenase isoenzyme 1, which is inhibited by pyruvate. As glycolysis produces an increase in pyruvate concentration and a decrease in NAD(+)/NADH, lactate and glucose consumption are not viable at the same time. In this context, we discuss ascorbic acid participation as a metabolic switch modulating neuronal metabolism between rest and activation periods. Ascorbic acid is highly concentrated in CNS. Glutamate stimulates ascorbic acid release from astrocytes. Ascorbic acid entry into neurons and within the cell can inhibit glucose consumption and stimulate lactate transport. For this switch to occur, an ascorbic acid flow is necessary between astrocytes and neurons, which is driven by neural activity and is part of vitamin C recycling. Here, we review the role of glucose and lactate as metabolic substrates and the modulation of neuronal metabolism by ascorbic acid.

  12. Correlation between root respiration and the levels of biomass and glycyrrhizic acid in Glycyrrhiza uralensis.

    Science.gov (United States)

    Liu, Wenlan; Sun, Zhirong; Qu, Jixu; Yang, Chunning; Zhang, Xiaomin; Wei, Xinxin

    2017-09-01

    The aim of the present study was to investigate the correlation between root respiration and the levels of biomass and glycyrrhizic acid in Glycyrrhiza uralensis . Root respiration was determined using a biological oxygen analyzer. Respiration-related enzymes including glucose-6-phosphate dehydrogenase plus 6-phosphogluconate dehydrogenase, phosphohexose isomerase and succinate dehydrogenase, and respiratory pathways were evaluated. Biomass was determined by a drying-weighing method. In addition, the percentage of glycyrrhizic acid was detected using high-performance liquid chromatography. The association between root respiration and the levels of biomass and glycyrrhizic acid was investigated. The glycolysis pathway (EMP), tricarboxylic acid cycle (TCA) and pentose phosphate (PPP) pathway acted concurrently in the roots of G. uralensis . Grey correlation analysis showed that TCA had the strongest correlation (correlation coefficient, 0.8003) with biomass. Starch and acetyl coenzyme A had the closest association with above-ground biomass, while soluble sugar correlated less strongly with above-ground biomass. Grey correlation analysis between biochemical pathways and the intermediates showed that pyruvic acid had the strongest correlation with EMP, while acetyl coenzyme A correlated most strongly with TCA. Among the intermediates and pathways, pyruvic acid and EMP exhibited the greatest correlation with glycyrrhizic acid, while acetyl coenzyme A and TCA correlated with glycyrrhizic acid less closely. The results of this study may aid the cultivation of G. uralensis . However, these results require verification in further studies.

  13. Aspartic acid

    Science.gov (United States)

    ... we eat. Aspartic acid is also called asparaginic acid. Aspartic acid helps every cell in the body work. It ... release Normal nervous system function Plant sources of aspartic acid include: avocado, asparagus, and molasses. Animal sources of ...

  14. Low content of Pt supported on Ni-MoCx/carbon black as a highly durable and active electrocatalyst for methanol oxidation, oxygen reduction and hydrogen evolution reactions in acidic condition

    Science.gov (United States)

    Zhang, Yan; Zang, Jianbing; Jia, Shaopei; Tian, Pengfei; Han, Chan; Wang, Yanhui

    2017-08-01

    Nickel and molybdenum carbide modified carbon black (Ni-MoCx/C) was synthesized by a two-step microwave-assisted deposition/carbonthermal reduction method and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The as-prepared Ni-MoCx/C supported Pt (10 wt%) electrocatalyst (10Pt/Ni-MoCx/C) was synthesized through a microwave-assisted reduction method and 10Pt/Ni-MoCx/C exhibited high electrocatalytic activity for methanol oxidation, oxygen reduction and hydrogen evolution reactions. Results showed that 10Pt/Ni-MoCx/C electrocatalyst had better electrocatalytic activity and stability performance than 20 wt% Pt/C (20Pt/C) electrocatalyst. Among them, the electrochemical surface area of 10Pt/Ni-MoCx/C reached 68.4 m2 g-1, which was higher than that of 20Pt/C (63.2 m2 g-1). The enhanced stability and activity of 10Pt/Ni-MoCx/C electrocatalyst were attributed to: (1) an anchoring effect of Ni and MoCx formed during carbonthermal reduction process; (2) a synergistic effect among Pt, Ni, MoOx and MoCx. These findings indicated that 10Pt/Ni-MoCx/C was a promising electrocatalyst for direct methanol fuel cells.

  15. The labeling of unsaturated gamma-hydroxybutyric acid by heavy isotopes of hydrogen: iridium complex-mediated H/D exchange by C-H bond activation vs reduction by boro-deuterides/tritides

    Czech Academy of Sciences Publication Activity Database

    Marek, Aleš; Pedersen, M. H. F.; Vogensen, S. B.; Clausen, R. P.; Frolund, B.; Elbert, Tomáš

    2016-01-01

    Roč. 59, č. 12 (2016), s. 476-483 ISSN 0362-4803 Institutional support: RVO:61388963 Keywords : C-H activation * borotritides * hydrogen/deuterium exchange * iridium catalyst * tritium-labeled gamma-hydroxybutyric acid Subject RIV: CC - Organic Chemistry Impact factor: 1.745, year: 2016

  16. Metal Catalysis with Nanostructured Metals Supported Inside Strongly Acidic Cross-linked Polymer Frameworks: Influence of Reduction Conditions of AuIII-containing Resins on Metal Nanoclusters Formation in Macroreticular and Gel-Type Materials

    Czech Academy of Sciences Publication Activity Database

    Calore, L.; Cavinato, g.; Canton, P.; Peruzzo, L.; Banavali, R.; Jeřábek, Karel; Corain, B.

    2012-01-01

    Roč. 391, AUG 30 (2012), s. 114-120 ISSN 0020-1693 Institutional support: RVO:67985858 Keywords : strongly acidic cross-linked polymer * frameworks * gold(0) nanoclusters Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.687, year: 2012

  17. Hydroxytyrosol prevents reduction in liver activity of Δ-5 and Δ-6 desaturases, oxidative stress, and depletion in long chain polyunsaturated fatty acid content in different tissues of high-fat diet fed mice.

    Science.gov (United States)

    Valenzuela, Rodrigo; Echeverria, Francisca; Ortiz, Macarena; Rincón-Cervera, Miguel Ángel; Espinosa, Alejandra; Hernandez-Rodas, María Catalina; Illesca, Paola; Valenzuela, Alfonso; Videla, Luis A

    2017-04-11

    Eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (AA, C20:4n-6) are long-chain polyunsaturated fatty acids (LCPUFAs) with relevant roles in the organism. EPA and DHA are synthesized from the precursor alpha-linolenic acid (ALA, C18:3n-3), whereas AA is produced from linoleic acid (LA, C18:2n-6) through the action of Δ5 and Δ6-desaturases. High-fat diet (HFD) decreases the activity of both desaturases and LCPUFA accretion in liver and other tissues. Hydroxytyrosol (HT), a natural antioxidant, has an important cytoprotective effects in different cells and tissues. Male mice C57BL/6 J were fed a control diet (CD) (10% fat, 20% protein, 70% carbohydrates) or a HFD (60% fat, 20% protein, 20% carbohydrates) for 12 weeks. Animals were daily supplemented with saline (CD) or 5 mg HT (HFD), and blood and the studied tissues were analyzed after the HT intervention. Parameters studied included liver histology (optical microscopy), activity of hepatic desaturases 5 and 6 (gas-liquid chromatography of methyl esters derivatives) and antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase by spectrophotometry), oxidative stress indicators (glutathione, thiobarbituric acid reactants, and the antioxidant capacity of plasma), gene expression assays for sterol regulatory element-binding protein 1c (SREBP-1c) (qPCR and ELISA), and LCPUFA profiles in liver, erythrocyte, brain, heart, and testicle (gas-liquid chromatography). HFD led to insulin resistance and liver steatosis associated with SREBP-1c upregulation, with enhancement in plasma and liver oxidative stress status and diminution in the synthesis and storage of n-6 and n-3 LCPUFAs in the studied tissues, compared to animals given control diet. HT supplementation significantly reduced fat accumulation in liver and plasma as well as tissue metabolic alterations induced by HFD. Furthermore, a normalization of desaturase activities

  18. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to sugar-free chewing gum sweetened with xylitol and plaque acid neutralisation (ID 485), maintenance of tooth mineralisation (ID 486, 562, 1181), reduction of dental

    DEFF Research Database (Denmark)

    Tetens, Inge

    claims in relation to sugar-free chewing gum sweetened with xylitol and plaque acid neutralisation, maintenance of tooth mineralisation, reduction of dental plaque, and defence against pathogens in the middle ear. 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 that is the subject of the health claims is sugar-free chewing gum sweetened with xylitol. The Panel considers that sugar-free chewing gum sweetened with xylitol...

  19. Reduction in language testing

    DEFF Research Database (Denmark)

    Dimova, Slobodanka; Jensen, Christian

    2013-01-01

    /video recorded speech samples and written reports produced by two experienced raters after testing. Our findings suggest that reduction or reduction-like pronunciation features are found in tested L2 speech, but whenever raters identify and comment on such reductions, they tend to assess reductions negatively......This study represents an initial exploration of raters' comments and actual realisations of form reductions in L2 test speech performances. Performances of three L2 speakers were selected as case studies and illustrations of how reductions are evaluated by the raters. The analysis is based on audio...

  20. Combined metabolomic and correlation networks analyses reveal fumarase insufficiency altered amino acid metabolism.

    Science.gov (United States)

    Hou, Entai; Li, Xian; Liu, Zerong; Zhang, Fuchang; Tian, Zhongmin

    2018-04-01

    Fumarase catalyzes the interconversion of fumarate and l-malate in the tricarboxylic acid cycle. Fumarase insufficiencies were associated with increased levels of fumarate, decreased levels of malate and exacerbated salt-induced hypertension. To gain insights into the metabolism profiles induced by fumarase insufficiency and identify key regulatory metabolites, we applied a GC-MS based metabolomics platform coupled with a network approach to analyze fumarase insufficient human umbilical vein endothelial cells (HUVEC) and negative controls. A total of 24 altered metabolites involved in seven metabolic pathways were identified as significantly altered, and enriched for the biological module of amino acids metabolism. In addition, Pearson correlation network analysis revealed that fumaric acid, l-malic acid, l-aspartic acid, glycine and l-glutamic acid were hub metabolites according to Pagerank based on their three centrality indices. Alanine aminotransferase and glutamate dehydrogenase activities increased significantly in fumarase deficiency HUVEC. These results confirmed that fumarase insufficiency altered amino acid metabolism. The combination of metabolomics and network methods would provide another perspective on expounding the molecular mechanism at metabolomics level. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Differential impact of amino acids on OXPHOS system activity following carbohydrate starvation in Arabidopsis cell suspensions.

    Science.gov (United States)

    Cavalcanti, João Henrique F; Quinhones, Carla G S; Schertl, Peter; Brito, Danielle S; Eubel, Holger; Hildebrandt, Tatjana; Nunes-Nesi, Adriano; Braun, Hans-Peter; Araújo, Wagner L

    2017-12-01

    Plant respiration mostly depends on the activity of glycolysis and the oxidation of organic acids in the tricarboxylic acid cycle to synthesize ATP. However, during stress situations plant cells also use amino acids as alternative substrates to donate electrons through the electron-transfer flavoprotein (ETF)/ETF:ubiquinone oxidoreductase (ETF/ETFQO) complex to the mitochondrial electron transport chain (mETC). Given this, we investigated changes of the oxidative phosphorylation (OXPHOS) system in Arabidopsis thaliana cell culture under carbohydrate starvation supplied with a range of amino acids. Induction of isovaleryl-CoA dehydrogenase (IVDH) activity was observed under carbohydrate starvation which was associated with increased amounts of IVDH protein detected by immunoblotting. Furthermore, activities of the protein complexes of the mETC were reduced under carbohydrate starvation. We also observed that OXPHOS system activity behavior is differently affected by different amino acids and that proteins associated with amino acids catabolism are upregulated in cells following carbohydrate starvation. Collectively, our results support the contention that ETF/ETFQO is an essential pathway to donate electrons to the mETC and that amino acids are alternative substrates to maintain respiration under carbohydrate starvation. © 2017 Scandinavian Plant Physiology Society.

  2. Fumaric acid: an overlooked form of fixed carbon in Arabidopsis and other plant species

    International Nuclear Information System (INIS)

    Chia, D.W.; Yoder, T.J.; Reiter, W.D.; Gibson, S.I.

    2000-01-01

    Photoassimilates are used by plants for production of energy, as carbon skeletons and in transport of fixed carbon between different plant organs. Many studies have been devoted to characterizing the factors that. regulate photoassimilate concentrations in different plant species. Most studies examining photoassimilate concentrations in C(sub 3) plants have focused on analyzing starch and soluble sugars. However, work presented here demonstrates that a number of C(sub 3) plants, including the popular model organism Arabidopsis thaliana (L.) Heynh., and agriculturally important plants, such as soybean[Glycine ma (L.) Merr.], contain significant quantities of furnaric acid. In fact, furnaric acid can accumulate to levels of several mg per g fresh weight in A-abidopsis leaves, often exceeding starch and soluble sugar levels. Furnaric acid is a component of the tricarboxylic acid cycle and, like starch and soluble sugars, can be metabolized to yield energy and carbon skeletons for production of other compounds. Fumaric acid concentrations increase with plant age and light intensity in Arabidopsis leaves. Arabidopsis phloem exudates contain significant quantities of fumaric acid, raising the possibility that fumaric acid may function in carbon transport

  3. Glucose and amino acid metabolism in rat brain during sustained hypoglycemia

    International Nuclear Information System (INIS)

    Wong, K.L.; Tyce, G.M.

    1983-01-01

    The metabolism of glucose in brains during sustained hypoglycemia was studied. [U- 14 C]Glucose (20 microCi) was injected into control rats, and into rats at 2.5 hr after a bolus injection of 2 units of insulin followed by a continuous infusion of 0.2 units/100 g rat/hr. This regimen of insulin injection was found to result in steady-state plasma glucose levels between 2.5 and 3.5 mumol per ml. In the brains of control rats carbon was transferred rapidly from glucose to glutamate, glutamine, gamma-aminobutyric acid and aspartate and this carbon was retained in the amino acids for at least 60 min. In the brains of hypoglycemic rats, the conversion of carbon from glucose to amino acids was increased in the first 15 min after injection. After 15 min, the specific activity of the amino acids decreased in insulin-treated rats but not in the controls. The concentrations of alanine, glutamate, and gamma-amino-butyric acid decreased, and the concentration of aspartate increased, in the brains of the hypoglycemic rats. The concentration of pyridoxal-5'-phosphate, a cofactor in many of the reactions whereby these amino acids are formed from tricarboxylic acid cycle intermediates, was less in the insulin-treated rats than in the controls. These data provide evidence that glutamate, glutamine, aspartate, and GABA can serve as energy sources in brain during insulin-induced hypoglycemia

  4. Fumaric acid: an overlooked form of fixed carbon in Arabidopsis and other plant species

    Energy Technology Data Exchange (ETDEWEB)

    Chia, D.W.; Yoder, T.J.; Reiter, W.D.; Gibson, S.I.

    2000-10-01

    Photoassimilates are used by plants for production of energy, as carbon skeletons and in transport of fixed carbon between different plant organs. Many studies have been devoted to characterizing the factors that. regulate photoassimilate concentrations in different plant species. Most studies examining photoassimilate concentrations in C{sub 3} plants have focused on analyzing starch and soluble sugars. However, work presented here demonstrates that a number of C{sub 3} plants, including the popular model organism Arabidopsis thaliana (L.) Heynh., and agriculturally important plants, such as soybean [Glycine ma (L.) Merr.], contain significant quantities of furnaric acid. In fact, furnaric acid can accumulate to levels of several mg per g fresh weight in A-abidopsis leaves, often exceeding starch and soluble sugar levels. Furnaric acid is a component of the tricarboxylic acid cycle and, like starch and soluble sugars, can be metabolized to yield energy and carbon skeletons for production of other compounds. Fumaric acid concentrations increase with plant age and light intensity in Arabidopsis leaves. Arabidopsis phloem exudates contain significant quantities of fumaric acid, raising the possibility that fumaric acid may function in carbon transport.

  5. L-[4-11C]aspartic acid: enzymatic synthesis, myocardial uptake, and metabolism

    International Nuclear Information System (INIS)

    Barrio, J.R.; Egbert, J.E.; Henze, E.; Schelbert, H.R.; Baumgartner, F.J.

    1982-01-01

    Sterile, pyrogen-free L-[4- 11 C]aspartic acid was prepared from 11 CO 2 using phosphoenolpyruvate carboxylase and glutamic/oxaloacetic acid transaminase immobilized on Sepharose supports to determine if it is a useful indicator for in vivo, noninvasive determination of myocardial metabolism. An intracoronary bolus injection of L-[4- 11 C]aspartic acid into dog myocardium showed a triexponential clearance curve with maximal production of 11 CO 2 100 s after injection. Inactivation of myocardial transaminase activity modified the tracer clearance and inhibited the production of 11 CO 2 . Positron-computed tomography imaging showed that the 11 C activities retained in rhesus monkey myocardium are higher than those observed in dog heart after intravenous injection of L-[4- 11 C]aspartic acid. These findings demonstrated the rapid incorporation of the carbon skeleton of L-aspartic acid into the tricarboxylic acid cycle after enzymatic transamination in myocardium and suggested that L-[4- 11 C]aspartic acid could be of value for in vivo, noninvasive assessment of local myocardial metabolism

  6. SELECTION AND PRELIMINARY EVALUATION OF ALTERNATIVE REDUCTANTS FOR SRAT PROCESSING

    Energy Technology Data Exchange (ETDEWEB)

    Stone, M.; Pickenheim, B.; Peeler, D.

    2009-06-30

    Defense Waste Processing Facility - Engineering (DWPF-E) has requested the Savannah River National Laboratory (SRNL) to perform scoping evaluations of alternative flowsheets with the primary focus on alternatives to formic acid during Chemical Process Cell (CPC) processing. The reductants shown below were selected for testing during the evaluation of alternative reductants for Sludge Receipt and Adjustment Tank (SRAT) processing. The reductants fall into two general categories: reducing acids and non-acidic reducing agents. Reducing acids were selected as direct replacements for formic acid to reduce mercury in the SRAT, to acidify the sludge, and to balance the melter REDuction/OXidation potential (REDOX). Non-acidic reductants were selected as melter reductants and would not be able to reduce mercury in the SRAT. Sugar was not tested during this scoping evaluation as previous work has already been conducted on the use of sugar with DWPF feeds. Based on the testing performed, the only viable short-term path to mitigating hydrogen generation in the CPC is replacement of formic acid with a mixture of glycolic and formic acids. An experiment using glycolic acid blended with formic on an 80:20 molar basis was able to reduce mercury, while also targeting a predicted REDuction/OXidation (REDOX) of 0.2 expressed as Fe{sup 2+}/{Sigma}Fe. Based on this result, SRNL recommends performing a complete CPC demonstration of the glycolic/formic acid flowsheet followed by a design basis development and documentation. Of the options tested recently and in the past, nitric/glycolic/formic blended acids has the potential for near term implementation in the existing CPC equipment providing rapid throughput improvement. Use of a non-acidic reductant is recommended only if the processing constraints to remove mercury and acidify the sludge acidification are eliminated. The non-acidic reductants (e.g. sugar) will not reduce mercury during CPC processing and sludge acidification would

  7. MCNP variance reduction overview

    International Nuclear Information System (INIS)

    Hendricks, J.S.; Booth, T.E.

    1985-01-01

    The MCNP code is rich in variance reduction features. Standard variance reduction methods found in most Monte Carlo codes are available as well as a number of methods unique to MCNP. We discuss the variance reduction features presently in MCNP as well as new ones under study for possible inclusion in future versions of the code

  8. Modern Reduction Methods

    CERN Document Server

    Andersson, Pher G

    2008-01-01

    With its comprehensive overview of modern reduction methods, this book features high quality contributions allowing readers to find reliable solutions quickly and easily. The monograph treats the reduction of carbonyles, alkenes, imines and alkynes, as well as reductive aminations and cross and heck couplings, before finishing off with sections on kinetic resolutions and hydrogenolysis. An indispensable lab companion for every chemist.

  9. Metabotyping of docosahexaenoic acid - treated Alzheimer's disease cell model.

    Directory of Open Access Journals (Sweden)

    Priti Bahety

    Full Text Available BACKGROUND: Despite the significant amount of work being carried out to investigate the therapeutic potential of docosahexaenoic acid (DHA in Alzheimer's disease (AD, the mechanism by which DHA affects amyloid-β precursor protein (AβPP-induced metabolic changes has not been studied. OBJECTIVE: To elucidate the metabolic phenotypes (metabotypes associated with DHA therapy via metabonomic profiling of an AD cell model using gas chromatography time-of-flight mass spectrometry (GC/TOFMS. METHODS: The lysate and supernatant samples of CHO-wt and CHO-AβPP695 cells treated with DHA and vehicle control were collected and prepared for GC/TOFMS metabonomics profiling. The metabolic profiles were analyzed by multivariate data analysis techniques using SIMCA-P+ software. RESULTS: Both principal component analysis and subsequent partial least squares discriminant analysis revealed distinct metabolites associated with the DHA-treated and control groups. A list of statistically significant marker metabolites that characterized the metabotypes associated with DHA treatment was further identified. Increased levels of succinic acid, citric acid, malic acid and glycine and decreased levels of zymosterol, cholestadiene and arachidonic acid correlated with DHA treatment effect. DHA levels were also found to be increased upon treatment. CONCLUSION: Our study shows that DHA plays a role in mitigating AβPP-induced impairment in energy metabolism and inflammation by acting on tricarboxylic acid cycle, cholesterol biosynthesis pathway and fatty acid metabolism. The perturbations of these metabolic pathways by DHA in CHO-wt and CHO-AβPP695 cells shed further mechanistic insights on its neuroprotective actions.

  10. Catalyzed reduction of nitrate in aqueous solutions

    International Nuclear Information System (INIS)

    Haas, P.A.

    1994-08-01

    Sodium nitrate and other nitrate salts in wastes is a major source of difficulty for permanent disposal. Reduction of nitrate using aluminum metal has been demonstrated, but NH 3 , hydrazine, or organic compounds containing oxygen would be advantageous for reduction of nitrate in sodium nitrate solutions. Objective of this seed money study was to determine minimum conditions for reduction. Proposed procedure was batchwise heating of aqueous solutions in closed vessels with monitoring of temperatures and pressures. A simple, convenient apparatus and procedure were demonstrated for observing formation of gaseous products and collecting samples for analyses. The test conditions were 250 degree C and 1000 psi max. Any useful reduction of sodium nitrate to sodium hydroxide as the primary product was not found. The nitrate present at pHs 3 or NH 4 NO 3 is easily decomposed, and the effect of nitromethane at these low pHs was confirmed. When acetic acid or formic acid was added, 21 to 56% of the nitrate in sodium nitrate solutions was reduced by methanol or formaldehyde. With hydrazine and acetic acid, 73 % of the nitrate was decomposed to convert NaNO 3 to sodium acetate. With hydrazine and formic acid, 36% of the nitrate was decomposed. If these products are more acceptable for final disposal than sodium nitrate, the reagents are cheap and the conversion conditions would be practical for easy use. Ammonium acetate or formate salts did not significantly reduce nitrate in sodium nitrate solutions

  11. Low content of Pt supported on Ni-MoC{sub x}/carbon black as a highly durable and active electrocatalyst for methanol oxidation, oxygen reduction and hydrogen evolution reactions in acidic condition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Zang, Jianbing; Jia, Shaopei; Tian, Pengfei; Han, Chan; Wang, Yanhui, E-mail: diamond_wangyanhui@163.com

    2017-08-01

    Highlights: • Ni-MoC{sub x}/C catalyst support was synthesized by a two-step method. • 10Pt/Ni-MoC{sub x}/C was an active and durable low Pt catalyst for MOR, ORR and HER. • The high stability of 10Pt/Ni-MoC{sub x}/C was ascribed to the anchoring effect of MoC{sub x}. • High activity of 10Pt/Ni-MoC{sub x}/C was due to a synergistic of Pt, Ni, MoO{sub x} and MoC{sub x}. - Abstract: Nickel and molybdenum carbide modified carbon black (Ni-MoC{sub x}/C) was synthesized by a two-step microwave-assisted deposition/carbonthermal reduction method and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The as-prepared Ni-MoC{sub x}/C supported Pt (10 wt%) electrocatalyst (10Pt/Ni-MoC{sub x}/C) was synthesized through a microwave-assisted reduction method and 10Pt/Ni-MoC{sub x}/C exhibited high electrocatalytic activity for methanol oxidation, oxygen reduction and hydrogen evolution reactions. Results showed that 10Pt/Ni-MoC{sub x}/C electrocatalyst had better electrocatalytic activity and stability performance than 20 wt% Pt/C (20Pt/C) electrocatalyst. Among them, the electrochemical surface area of 10Pt/Ni-MoC{sub x}/C reached 68.4 m{sup 2} g{sup −1}, which was higher than that of 20Pt/C (63.2 m{sup 2} g{sup −1}). The enhanced stability and activity of 10Pt/Ni-MoC{sub x}/C electrocatalyst were attributed to: (1) an anchoring effect of Ni and MoC{sub x} formed during carbonthermal reduction process; (2) a synergistic effect among Pt, Ni, MoO{sub x} and MoC{sub x}. These findings indicated that 10Pt/Ni-MoC{sub x}/C was a promising electrocatalyst for direct methanol fuel cells.

  12. Reduction of plasma asymmetric dimethylarginine in obese patients with chronic kidney disease after three years of a low-protein diet supplemented with keto-amino acids: a randomized controlled trial.

    Science.gov (United States)

    Teplan, Vladimir; Schück, Otto; Racek, Jaroslav; Mareckova, Olga; Stollova, Milena; Hanzal, Vladimir; Malý, Jan

    2008-01-01

    Levels of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) are elevated in chronic kidney disease (CKD) and may contribute to vascular complications. In this study we tested the hypothesis that elevated ADMA can be reduced in obese CKD patients by long-term administration of a low-protein diet supplemented with keto-amino acids. In a long-term prospective double-blind placebo-controlled randomized trial, we evaluated for a period of 36 months a total of 111 CKD patients (54 men, 57 women) aged 22-76 years with obesity (BMI >or= 30 kg/m(2)) and an inulin clearance rate (C(in)) of 22-40 ml/min/1.73 m(2). All patients were on a low-protein diet containing 0.6 g protein/kg BW per day and 120-125 kJ/kg BW per day. The diet was randomly supplemented with keto-amino acids at a dosage of 100 mg/kg BW per day (66 patients, Group I); 65 patients received placebo (Group II). During the study period, the glomerular filtration rate decreased slightly in Group I (C(in) from 32.4 +/- 12.6 to 29.8 +/- 8.6 ml/min/1.73 m(2)) and more markedly in Group II (from 33.2 +/- 12.6 to 23.2 +/- 98.4 ml/min/1.73 m(2), P diet and keto-amino acids in CKD patients with obesity led to decreases of ADMA, visceral body fat and proteinuria. Concomitant decreases of glycated hemoglobin, LDL-cholesterol and pentosidine may also contribute to the delay in progression of renal failure.

  13. Crystalline amino acids and nitrogen emission

    NARCIS (Netherlands)

    Verstegen, M.W.A.; Jongbloed, A.W.

    2003-01-01

    Reductions in dietary protein level and supplementation with certain crystalline amino acids is a well-established method of formulating diets to achieve a more ideal amino acid pattern and to reduce nitrogen excretion. Up to 35% reduction in nitrogen excretion may be achieved by supplementing pig

  14. Photochemical reduction of uranyl ion with triphenylphosphine

    International Nuclear Information System (INIS)

    Brar, A.S.; Sidhu, M.S.; Sandhu, S.S.

    1981-01-01

    Photochemical reduction of uranyl ion with triphenylphosphine has been studied in acetone-water medium in the presence of sulphuric acid at 346nm, 400nm and 434nm wavelengths. The photochemical reduction is of second order and increases with increase in hydrogen ion concentration. Absorption spectra of uranyl ion in acidic medium and uranyl ion with triphenylphosphine do not show any ground state complex formation. The value of quantum yield increases with the wavelength of the radiation increase from 346 to 434nm. Plots of reciprocal of quantum yield for the formation of U(IV) versus reciprocal [triphenylphosphine] are linear. Products characterized by UV and visible, IR and TLC show the formation of U(IV) and triphenylphosphine oxide. On the basis of above observations mechanism of the photochemical reduction has been proposed. (author)

  15. Energetic and metabolic transient response of Saccharomyces cerevisiae to benzoic acid.

    Science.gov (United States)

    Kresnowati, M T A P; van Winden, W A; van Gulik, W M; Heijnen, J J

    2008-11-01

    Saccharomyces cerevisiae is known to be able to adapt to the presence of the commonly used food preservative benzoic acid with a large energy expenditure. Some mechanisms for the adaptation process have been suggested, but its quantitative energetic and metabolic aspects have rarely been discussed. This study discusses use of the stimulus response approach to quantitatively study the energetic and metabolic aspects of the transient adaptation of S. cerevisiae to a shift in benzoic acid concentration, from 0 to 0.8 mM. The information obtained also serves as the basis for further utilization of benzoic acid as a tool for targeted perturbation of the energy system, which is important in studying the kinetics and regulation of central carbon metabolism in S. cerevisiae. Using this experimental set-up, we found significant fast-transient (< 3000 s) increases in O(2) consumption and CO(2) production rates, of approximately 50%, which reflect a high energy requirement for the adaptation process. We also found that with a longer exposure time to benzoic acid, S. cerevisiae decreases the cell membrane permeability for this weak acid by a factor of 10 and decreases the cell size to approximately 80% of the initial value. The intracellular metabolite profile in the new steady-state indicates increases in the glycolytic and tricarboxylic acid cycle fluxes, which are in agreement with the observed increases in specific glucose and O(2) uptake rates.

  16. Indirect fluorescence detection of native amino acids in capillary zone electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Kuhr, W.G.; Yeung, E.S.

    1988-09-01

    Amino acids are but one of several important classes of small chemical compounds in biological chemistry that have an inherent lack of analytically useful physical properties. Amino acids, peptides, fatty acids, sugars, many mono-, di-, and tricarboxylic acids, and phosphorylated intermediates in glycolysis and metabolism show little, if any, UV or visible absorption, fluorescence, or electrochemical activity. As the emphasis of biochemical research shifts to smaller samples where, for example, picomolar quantities of amino acids are analyzed in gas phase protein sequencing or in microliter samples of the extracellular fluid of the mammalian brain, the analytical problem becomes even more challenging due to the small volume of sample available for analysis. In this work, laser-induced fluorescence spectroscopy is performed on-colum