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Sample records for acid oxidation capacity

  1. Large discharge capacity from carbon electrodes in sulfuric acid with oxidant

    NASA Astrophysics Data System (ADS)

    Inagaki, M.; Iwashita, N.

    The discharge performance of the graphite intercalation compounds in sulfuric acid containing nitric acid (H 2SO 4-GICs) was studied by focusing on the effects of oxidant and carbon nanotexture. A large discharge capacity from H 2SO 4-GICs synthesized by using an excess amount of HNO 3, more than 150 times of the theoretical value (93 mAh/g carbon), was obtained depending on the amount of oxidant added, the discharge current, and the nanotexture of carbon electrode. The experimental results are explained in terms of competition between the de-intercalation of sulfuric acid due to galvanostatic reduction and the re-intercalation due to chemical oxidation by HN03 during discharging. However, a subsidiary reaction decreases the effective amount of HNO 3 on the discharge by a small current and also on the cycle of chemical charging and electrochemical discharging. The oxidant KMnO 4 gave only a little larger capacity for discharge than the theoretical one, because it was reduced to the manganese oxide precipitates during the oxidation of the carbon electrode.

  2. Improvement of Pro-Oxidant Capacity of Protocatechuic Acid by Esterification

    PubMed Central

    Zeraik, Maria Luiza; Petrônio, Maicon S.; Coelho, Dyovani; Regasini, Luis Octavio; Silva, Dulce H. S.; da Fonseca, Luiz Marcos; Machado, Sergio A. S.; Bolzani, Vanderlan S.; Ximenes, Valdecir F.

    2014-01-01

    Pro-oxidant effects of phenolic compounds are usually correlated to the one-electron redox potential of the phenoxyl radicals. Here we demonstrated that, besides their oxidizability, hydrophobicity can also be a decisive factor. We found that esterification of protocatechuic acid (P0) provoked a profound influence in its pro-oxidant capacity. The esters bearing alkyl chains containing two (P2), four (P4) and seven (P7) carbons, but not the acid precursor (P0), were able to exacerbate the oxidation of trolox, α-tocopherol and rifampicin. This effect was also dependent on the catechol moiety, since neither gallic acid nor butyl gallate showed any pro-oxidant effects. A comparison was also made with apocynin, which is well-characterized regarding its pro-oxidant properties. P7 was more efficient than apocynin regarding co-oxidation of trolox. However, P7 was not able to co-oxidize glutathione and NADH, which are targets of the apocynin radical. A correlation was found between pro-oxidant capacity and the stability of the radicals, as suggested by the intensity of the peak current in the differential pulse voltammetry experiments. In conclusion, taking into account that hydroquinone and related moieties are frequently found in biomolecules and quinone-based chemotherapeutics, our demonstration that esters of protocatechuic acid are specific and potent co-catalysts in their oxidations may be very relevant as a pathway to exacerbate redox cycling reactions, which are usually involved in their biological and pharmacological mechanisms of action. PMID:25340774

  3. Improvement of pro-oxidant capacity of protocatechuic acid by esterification.

    PubMed

    Zeraik, Maria Luiza; Petrônio, Maicon S; Coelho, Dyovani; Regasini, Luis Octavio; Silva, Dulce H S; da Fonseca, Luiz Marcos; Machado, Sergio A S; Bolzani, Vanderlan S; Ximenes, Valdecir F

    2014-01-01

    Pro-oxidant effects of phenolic compounds are usually correlated to the one-electron redox potential of the phenoxyl radicals. Here we demonstrated that, besides their oxidizability, hydrophobicity can also be a decisive factor. We found that esterification of protocatechuic acid (P0) provoked a profound influence in its pro-oxidant capacity. The esters bearing alkyl chains containing two (P2), four (P4) and seven (P7) carbons, but not the acid precursor (P0), were able to exacerbate the oxidation of trolox, α-tocopherol and rifampicin. This effect was also dependent on the catechol moiety, since neither gallic acid nor butyl gallate showed any pro-oxidant effects. A comparison was also made with apocynin, which is well-characterized regarding its pro-oxidant properties. P7 was more efficient than apocynin regarding co-oxidation of trolox. However, P7 was not able to co-oxidize glutathione and NADH, which are targets of the apocynin radical. A correlation was found between pro-oxidant capacity and the stability of the radicals, as suggested by the intensity of the peak current in the differential pulse voltammetry experiments. In conclusion, taking into account that hydroquinone and related moieties are frequently found in biomolecules and quinone-based chemotherapeutics, our demonstration that esters of protocatechuic acid are specific and potent co-catalysts in their oxidations may be very relevant as a pathway to exacerbate redox cycling reactions, which are usually involved in their biological and pharmacological mechanisms of action. PMID:25340774

  4. Reduced capacity for fatty acid oxidation in rats with inherited susceptibility to diet-induced obesity.

    PubMed

    Ji, Hong; Friedman, Mark I

    2007-08-01

    High-fat, energy-dense diets promote weight gain and obesity in humans and other animals, but the mechanisms underlying such diet-induced obesity remain elusive. To determine whether a reduced capacity to oxidize fat is involved in the etiology of diet-induced obesity, we examined different measures of fatty acid oxidation in rats selectively bred for susceptibility (DIO) or resistance (DR) to dietary obesity before and after they were fed a high-fat diet and became obese. DIO rats eating a low-fat diet oxidized less dietary fatty acid in vivo and had lower levels of plasma ketone bodies during fasting compared with DR rats. Lean DIO rats fed a low-fat diet showed reduced liver messenger RNA expression of CD36, which transports fatty acids across cell membranes, and long-chain acyl-coenzyme A dehydrogenase (ACADL), which catalyzes the first step in the mitochondrial beta-oxidation of fatty acids. The deficit in CD36 and ACADL messenger RNA expression was also seen in obese DIO rats that had been eating a high-fat diet and, in addition, was accompanied by reduced expression of liver carnitine palmitoyl transferase I, the enzyme that mediates transport of long-chain fatty acids into mitochondria. No differences were found in the expression of liver enzymes involved in fat synthesis; however, in muscle, DIO rats fed the low-fat, but not high-fat, diet showed greater expression of diacylglycerol O-acyltransferase 1 and lipoprotein lipase than did DR rats. Expression of muscle enzymes involved in fatty acid oxidation was similar in the 2 groups. These findings provide a metabolic mechanism for the development of diet-induced obesity and thus suggest potential targets for intervention strategies to treat or prevent it. PMID:17618960

  5. Dietary fatty acid composition changes mitochondrial phospholipids and oxidative capacities in rainbow trout red muscle.

    PubMed

    Guderley, H; Kraffe, E; Bureau, W; Bureau, D P

    2008-03-01

    Dietary conditioning of juvenile trout changed the acyl chain composition of mitochondrial phospholipids and the oxidative capacities of muscle mitochondria. Trout were fed three diets differing only in fatty acid (FA) composition. The highly unsaturated 22:6 n-3 (DHA) accounted for 0.4, 14, and 30% of fatty acids in Diets 1, 2 and 3. After 10 weeks of growth, the dietary groups differed markedly in FA composition of mitochondrial phospholipids, with significant dietary effects for virtually all FA. Mean mitochondrial DHA levels were 19, 40 and 33% in trout fed Diets 1, 2 and 3. Mitochondrial oxidative capacities changed with diet, while mitochondrial concentrations of cytochromes and of the adenylate nucleotide translocase (nmol mg(1) protein) did not. Mitochondria from fish fed Diet 1 had higher non-phosphorylating (state 4) rates at 5 degrees C than those fed other diets. When phosphorylating (state 3) rates differed between dietary groups, rates at 5 and 15 degrees C were higher for fish fed the more unsaturated diets. Stepwise multiple regressions indicated that FA composition could explain much (42-70%) of the variability of state 4 rates, particularly at 5 degrees C. At 15 degrees C, FA composition explained 16-42% of the variability of states 3 and 4 rates. Similar conclusions were obtained for the complete data set (trout fed diets 1, 2 and 3) and for the data from trout achieving similar growth rates (e.g. those fed Diets 1 and 2). Neither general characteristics of membrane FA, such as % saturates, unsaturation index, n-3, n-6 or n-3/n-6 nor levels of abundant unsaturated FA such as DHA or 18:1(n-9 + n-7), were systematically correlated with mitochondrial capacities even though they differed considerably between trout fed the different diets. Relatively minor FA (20:5n-3, 20:0, 18:2n-6, 18:3n-3, 18:0 and 15:0) showed better correlations with mitochondrial oxidative capacities. This supports the concept that acyl chain composition modulates mitochondrial

  6. Eicosapentaenoic acid but not docosahexaenoic acid restores skeletal muscle mitochondrial oxidative capacity in old mice

    PubMed Central

    Johnson, Matthew L; Lalia, Antigoni Z; Dasari, Surendra; Pallauf, Maximilian; Fitch, Mark; Hellerstein, Marc K; Lanza, Ian R

    2015-01-01

    Mitochondrial dysfunction is often observed in aging skeletal muscle and is implicated in age-related declines in physical function. Early evidence suggests that dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) improve mitochondrial function. Here, we show that 10 weeks of dietary eicosapentaenoic acid (EPA) supplementation partially attenuated the age-related decline in mitochondrial function in mice, but this effect was not observed with docosahexaenoic acid (DHA). The improvement in mitochondrial function with EPA occurred in the absence of any changes in mitochondrial abundance or biogenesis, which was evaluated from RNA sequencing, large-scale proteomics, and direct measurements of muscle mitochondrial protein synthesis rates. We find that EPA improves muscle protein quality, specifically by decreasing mitochondrial protein carbamylation, a post-translational modification that is driven by inflammation. These results demonstrate that EPA attenuated the age-related loss of mitochondrial function and improved mitochondrial protein quality through a mechanism that is likely linked with anti-inflammatory properties of n-3 PUFAs. Furthermore, we demonstrate that EPA and DHA exert some common biological effects (anticoagulation, anti-inflammatory, reduced FXR/RXR activation), but also exhibit many distinct biological effects, a finding that underscores the importance of evaluating the therapeutic potential of individual n-3 PUFAs. PMID:26010060

  7. Moderate carnitine depletion and long-chain fatty acid oxidation, exercise capacity, and nitrogen balance in the rat.

    PubMed

    Heinonen, O J; Takala, J

    1994-09-01

    Carnitine plays a central role in lipid metabolism by transporting long-chain fatty acids into the mitochondria for beta-oxidation. Reduction of carnitine concentration does not automatically imply that functional carnitine deficiency exists with direct consequences on energy metabolism. In our experimental model, we reduced tissue concentrations of carnitine to levels that are comparable to those in patients with various metabolic disorders with secondary carnitine deficiency and did a study on the in vivo effects of moderate carnitine depletion on palmitate oxidation, exercise capacity, and nitrogen balance. Thirty rats were divided into a carnitine-depleted group (group I) and pair-fed controls (group II). Carnitine depletion resulting in a 48% reduction of tissue carnitine concentrations was induced by feeding ad libitum a carnitine-free oral diet consisting of parenteral nutrition solutions. Palmitate oxidation was measured by collecting expired 14CO2 after an intraperitoneal injection of [1-14C]palmitate, and exercise capacity was determined by having the rats swim to exhaustion. Despite the 48% depletion of carnitine in serum, muscle, and liver, there were no differences in cumulative palmitate oxidation in 3 h (group I, 40 +/- 7%; group II, 37 +/- 9% of injected activity), swimming time to exhaustion (group I, 8.1 +/- 2.8 h; group II, 7.7 +/- 3.6 h), or nitrogen balance (group I, 1.1 +/- 0.5 g of nitrogen/kg/d; group II, 1.2 +/- 0.5 g of nitrogen/kg/d). We conclude that carnitine depletion of 48% has no effect on palmitate oxidation, exercise capacity, or nitrogen balance in the rats studied. PMID:7808823

  8. High fatty acid oxidation capacity and phosphorylation control despite elevated leak and reduced respiratory capacity in northern elephant seal muscle mitochondria.

    PubMed

    Chicco, Adam J; Le, Catherine H; Schlater, Amber; Nguyen, Alex; Kaye, Spencer; Beals, Joseph W; Scalzo, Rebecca L; Bell, Christopher; Gnaiger, Erich; Costa, Daniel P; Crocker, Daniel E; Kanatous, Shane B

    2014-08-15

    Northern elephant seals (Mirounga angustirostris) are extreme, hypoxia-adapted endotherms that rely largely on aerobic metabolism during extended breath-hold dives in near-freezing water temperatures. While many aspects of their physiology have been characterized to account for these remarkable feats, the contribution of adaptations in the aerobic powerhouses of muscle cells, the mitochondria, are unknown. In the present study, the ontogeny and comparative physiology of elephant seal muscle mitochondrial respiratory function was investigated under a variety of substrate conditions and respiratory states. Intact mitochondrial networks were studied by high-resolution respirometry in saponin-permeabilized fiber bundles obtained from primary swimming muscles of pup, juvenile and adult seals, and compared with fibers from adult human vastus lateralis. Results indicate that seal muscle maintains a high capacity for fatty acid oxidation despite a progressive decrease in total respiratory capacity as animals mature from pups to adults. This is explained by a progressive increase in phosphorylation control and fatty acid utilization over pyruvate in adult seals compared with humans and seal pups. Interestingly, despite higher indices of oxidative phosphorylation efficiency, juvenile and adult seals also exhibit a ~50% greater capacity for respiratory 'leak' compared with humans and seal pups. The ontogeny of this phenotype suggests it is an adaptation of muscle to the prolonged breath-hold exercise and highly variable ambient temperatures experienced by mature elephant seals. These studies highlight the remarkable plasticity of mammalian mitochondria to meet the demands for both efficient ATP production and endothermy in a cold, oxygen-limited environment. PMID:24902742

  9. Immunoenhancing effect of trans-10, cis-12 conjugated linoleic acid on the phagocytic capacity and oxidative burst activity of canine peripheral blood phagocytes.

    PubMed

    Cho, Min-Haeng; Kang, Ji-Houn; Yang, Mhan-Pyo

    2008-10-01

    The effect of trans-10, cis-12 conjugated linoleic acid (t10c12-CLA) on the phagocytic capacity and oxidative burst activity (OBA) of canine peripheral blood phagocytes was examined. t10c12-CLA did not directly affect the phagocytic capacity and OBA of peripheral blood mononuclear cells (PBMC), monocytes or polymorphonuclear cells (PMN). However, the phagocytic capacity of PMN and monocytes was enhanced by the culture supernatant from t10c12-CLA-treated PBMC. This supernatant enhanced the latex bead-induced OBA of PMN and monocytes. t10c12-CLA also increased TNF-alpha production by PBMC. Recombinant canine (rc) TNF-alpha also increased the phagocytic capacity and OBA of PMN and monocytes. The ability of the culture supernatant from t10c12-CLA-treated PBMC to stimulate the phagocytic capacity and OBA of phagocytes was inhibited by anti-rcTNF-alpha pAb. These results suggest that t10c12-CLA has an immunoenhancing effect on the phagocytic capacity and OBA of phagocytes, and this effect may be mediated by TNF-alpha released from t10c12-CLA-treated PBMC. PMID:18234254

  10. An electrochemical sensor for gallic acid based on Fe₂O₃/electro-reduced graphene oxide composite: Estimation for the antioxidant capacity index of wines.

    PubMed

    Gao, Feng; Zheng, Delun; Tanaka, Hidekazu; Zhan, Fengping; Yuan, Xiaoning; Gao, Fei; Wang, Qingxiang

    2015-12-01

    A highly sensitive electrochemical sensor for gallic acid (GA), an important polyphenolic compound, was fabricated using the hybrid material of chitosan (CS), fishbone-shaped Fe2O3 (fFe2O3), and electrochemically reduced graphene oxide (ERGO) as the sensing matrix. The electrochemical characterization experiments showed that the CS-fFe2O3-ERGO modified glassy carbon electrode (CS-fFe2O3-ERGO/GCE) had large surface area, excellent electronic conductivity and high stability. The GA presented a superior electrochemical response on CS-fFe2O3-ERGO/GCE in comparison with the single-component modified electrode. The electrochemical mechanism and optimal test conditions of GA on the electrode surface were carefully investigated. Under the optimal conditions, the oxidation peak currents in differential pulse voltammetry (DPV) experiments exhibited a good linear relationship with the logarithmic values of GA concentration over the range from 1.0×10(-6)M to 1.0×10(-4)M. Based on signal-to-noise (S/N) characteristic of 3, the detection limit was estimated to be 1.5×10(-7)M. The proposed sensor has also been applied for estimating the antioxidant capacity index of real samples of red and white wines. PMID:26354265

  11. Changes in mitochondrial oxidative capacities during thermal acclimation of rainbow trout Oncorhynchus mykiss: roles of membrane proteins, phospholipids and their fatty acid compositions.

    PubMed

    Kraffe, Edouard; Marty, Yanic; Guderley, Helga

    2007-01-01

    Changes in the properties of mitochondria from oxidative muscle of rainbow trout Oncorhynchus mykiss were examined during warm (5 degrees C to 15 degrees C) acclimation. Trout were studied shortly after the initial thermal change and after 8 weeks acclimation to 15 degrees C. To identify potential mechanisms by which oxidative capacities change, the modifications of phospholipid composition, membrane proteins and functional capacities of red muscle mitochondria were examined. Marked functional changes of isolated muscle mitochondria during warm acclimation of rainbow trout were reflected by a host of modifications in phospholipid composition, but by few shifts in protein components. Shortly after transfer of trout from 5 degrees C to 15 degrees C, the maximal oxidative capacity of mitochondria measured at 15 degrees C increased slightly, but rates at both assay temperatures (5 degrees C and 15 degrees C) decreased markedly after warm acclimation. The increase in capacity in short-term warm exposed trout was most pronounced when rates at 15 degrees C were expressed relative to cytochrome a and c(1) levels. Non-phosphorylating (State 4) rates of oxygen uptake increased with short-term warm exposure before returning to initial levels after warm acclimation. Cytochrome c oxidase (CCO) activity in the mitochondrial preparations decreased with warm acclimation. The thermal sensitivity of the ADP affinity was markedly modified during short-term warm exposure, when the ADP/O ratio increased, but warm acclimation returned these values to those observed initially. ADP affinity increased after warm acclimation. Changes in the mitochondrial content of cytochromes and adenine nucleotide translocase (ANT) could not explain these patterns. On the other hand, changes in the proportions of the lipid classes and in the acyl chain composition of certain phospholipid classes mirror the modifications in functional properties. Short-term exposure to 15 degrees C decreased the ratio of

  12. Effects of abdominal surgery on thiobarbituric acid reactive substances and plasma anti-oxidative capacity in dairy cows.

    PubMed

    Mudron, P; Herzog, K; Höltershinken, M; Rehage, J

    2007-10-01

    The present investigation was undertaken to study the effects of surgical stress on thiobarbituric acid reactive substances (TBARS) and ferric reducing ability of plasma (FRAP) in dairy cows. Ten Holstein-Friesian dairy cows, mean age 5.26 years, admitted for treatment of left abomasal displacement (omentopexy), were used in our study. Blood samples were collected from the jugular vein prior to surgery, immediately and then 15, 30, 60, 90 min, and 2, 5, 10, and 24 h after reposition of abomasum. Surgical stress resulted in a significant increase in plasma cortisol concentrations (P < 0.001) with the highest mean levels 15 min after surgery (32.4 +/- 18.1 microg/l) as well as in serum levels of glucose (P < 0.001) and non-esterified fatty acids (P < 0.001). Similarly, surgery transiently enhanced the plasma levels of TBARS (P < 0.001). The highest TBARS plasma levels (0.91 +/- 0.18 micromol/l) were recognized 60 min after reposition of abomasums. There were no significant differences in FRAP in dairy cows before and after reposition of abomasum. In conclusion, these data indicate that stress reaction caused by surgical correction of left displacement of abomasum can be associated with higher production of TBARS. PMID:17877587

  13. Adaptability of the oxidative capacity of motoneurons

    NASA Technical Reports Server (NTRS)

    Chalmers, G. R.; Roy, R. R.; Edgerton, V. R.

    1992-01-01

    Previous studies have demonstrated that a chronic change in neuronal activation can produce a change in soma oxidative capacity, suggesting that: (i) these 2 variables are directly related in neurons and (ii) ion pumping is an important energy requiring activity of a neuron. Most of these studies, however, have focused on reduced activation levels of sensory systems. In the present study the effect of a chronic increase or decrease in motoneuronal activity on motoneuron oxidative capacity and soma size was studied. In addition, the effect of chronic axotomy was studied as an indicator of whether cytoplasmic volume may also be related to the oxidative capacity of motoneurons. A quantitative histochemical assay for succinate dehydrogenase activity was used as a measure of motoneuron oxidative capacity in experimental models in which chronic electromyography has been used to verify neuronal activity levels. Spinal transection reduced, and spinal isolation virtually eliminated lumbar motoneuron electrical activity. Functional overload of the plantaris by removal of its major synergists was used to chronically increase neural activity of the plantaris motor pool. No change in oxidative capacity or soma size resulted from either a chronic increase or decrease in neuronal activity level. These data indicate that the chronic modulation of ionic transport and neurotransmitter turnover associated with action potentials do not induce compensatory metabolic responses in the metabolic capacity of the soma of lumbar motoneurons. Soma oxidative capacity was reduced in the axotomized motoneurons, suggesting that a combination of axoplasmic transport, intracellular biosynthesis and perhaps neurotransmitter turnover represent the major energy demands on a motoneuron. While soma oxidative capacity may be closely related to neural activity in some neural systems, e.g. visual and auditory, lumbar motoneurons appear to be much less sensitive to modulations in chronic activity levels.

  14. Oxidation-reduction capacities of aquifer solids

    SciTech Connect

    Barcelona, M.J.; Holm, T.R.

    1991-01-01

    Oxidation-reduction processes play a major role in the mobility, transport, and fate of inorganic and organic chemical constituents in natural waters. Therefore, the manipulation of redox conditions in natural and treated water systems is assumed to be a common option for the control of contaminant concentrations. Measurements of the oxidation (i.e., of aqueous Cr(2+)) and reduction (i.e., of aqueous Cr2O7(2-) and H2O2) capacities of aquifer solids and groundwater have been made on samples from a sand-and-gravel aquifer. The groundwater contributed less than 1% of the system oxidation or reduction poising capacity. Reduction capacities averaged 0.095, 0.111, and 0.136 mequiv/g of dry solids for oxic, transitional, and reducing Eh conditions, respectively. Measured oxidation capacities averaged 0.4 mequiv/g of dry solids over the range of redox intensity conditions. These capacities represent considerable resistance to the adjustment of redox conditions even at uncontaminated sites. Hydrogen peroxide reduction by aquifer solid samples proceeds rapidly relative to microbially mediated decomposition. The study indicates the need for closer scrutiny of the predictability and cost effectiveness of attempts to manipulate redox conditions in poorly poised aquifer systems.

  15. OXIDATION-REDUCTION CAPACITIES OF AQUIFER SOLIDS

    EPA Science Inventory

    Measurements of the oxidation (i.e., of aqueous Cr2+) and reduction (i.e., of aqueous Cr2O72- and H202) capacities of aquifer solids and groundwater have been made on samples from a sand-and-gravel aquifer. The gro...

  16. Long-chain acyl-CoA synthetase 2 knockdown leads to decreased fatty acid oxidation in fat body and reduced reproductive capacity in the insect Rhodnius prolixus.

    PubMed

    Alves-Bezerra, Michele; Klett, Eric L; De Paula, Iron F; Ramos, Isabela B; Coleman, Rosalind A; Gondim, Katia C

    2016-07-01

    Long-chain acyl-CoA esters are important intermediates in lipid metabolism and are synthesized from fatty acids by long-chain acyl-CoA synthetases (ACSL). The hematophagous insect Rhodnius prolixus, a vector of Chagas' disease, produces glycerolipids in the midgut after a blood meal, which are stored as triacylglycerol in the fat body and eggs. We identified twenty acyl-CoA synthetase genes in R. prolixus, two encoding ACSL isoforms (RhoprAcsl1 and RhoprAcsl2). RhoprAcsl1 transcripts increased in posterior midgut on the second day after feeding, and RhoprAcsl2 was highly transcribed on the tenth day. Both enzymes were expressed in Escherichia coli. Recombinant RhoprACSL1 and RhoprACSL2 had broad pH optima (7.5-9.5 and 6.5-9.5, respectively), were inhibited by triacsin C, and were rosiglitazone-insensitive. Both showed similar apparent Km for palmitic and oleic acid (2-6 μM), but different Km for arachidonic acid (0.5 and 6 μM for RhoprACSL1-Flag and RhoprACSL2-Flag, respectively). The knockdown of RhoprAcsl1 did not result in noticeable phenotypes. However, RhoprACSL2 deficient insects exhibited a 2.5-fold increase in triacylglycerol content in the fat body, and 90% decrease in fatty acid β-oxidation. RhoprAcsl2 knockdown also resulted in 20% increase in lifespan, delayed digestion, 30% reduced oviposition, and 50% reduction in egg hatching. Laid eggs and hatched nymphs showed remarkable alterations in morphology. In summary, R. prolixus ACSL isoforms have distinct roles on lipid metabolism. Although RhoprACSL1 functions remain unclear, we propose that RhoprACSL2 is the main contributor for the formation of the intracellular acyl-CoA pool channeled for β-oxidation in the fat body, and is also required for normal reproduction. PMID:27091636

  17. Treatment of Fatty Acid Oxidation Disorders

    MedlinePlus

    ... of fatty acid oxidation disorders Treatment of fatty acid oxidation disorders E-mail to a friend Please ... page It's been added to your dashboard . Fatty acid oxidation disorders are rare health conditions that affect ...

  18. BACTERIAL OXIDATION OF DIPICOLINIC ACID

    PubMed Central

    Kobayashi, Yasuo; Arima, Kei

    1962-01-01

    Kobayashi, Yasuo (University of Tokyo, Tokyo, Japan) and Kei Arima. Bacterial oxidation of dipicolinic acid. II. Identification of α-ketoglutaric acid and 3-hydroxydipicolinic acid and some properties of cell-free extracts. J. Bacteriol. 84:765–771. 1962—When a dipicolinic acid (DPA)-decomposing bacterium, Achromobacter strain 1–2, was incubated at 30 C with shaking in a DPA solution containing 10−3m arsenite, a keto acid was accumulated. The 2,4-dinitrophenylhydrazone of this acid was synthesized and identified as α-ketoglutaric acid by paper chromatography, visible absorption spectrum, infrared analysis, elemental analysis, and mixed melting point. During this incubation, oxalic acid equivalent to the consumed dipicolinic acid was produced. A fluorescent material was also isolated from culture fluid and identified as 3-hydroxydipicolinic acid by paper chromatography and the ultraviolet absorption spectrum. Further, cell-free extracts were prepared by sonic oscillation. Ferrous ion and a reduced di- or triphosphopyridine nucleotide-generating system were proven to be required for enzymic oxidation of DPA. And 3-hydroxydipicolinic acid was also oxidized by this preparation. From the results obtained, a possible metabolic pathway of dipicolinic acid was proposed. PMID:14033954

  19. Heat capacities of amino acids, peptides and proteins.

    PubMed

    Makhatadze, G I

    1998-04-20

    The heat capacity is one of the fundamental parameters describing thermodynamic properties of a system. It has wide applications in a number of areas such as polymer chemistry, protein folding and DNA stability. To aid the scientific community in the analysis of such data, I have compiled a database on the experimentally measured heat capacities of amino acids, polyamino acids, peptides, and proteins in solid state and in aqueous solutions. PMID:9648205

  20. Substrate oxidation capacity in rodent skeletal muscle: effects of exposure to zero gravity

    NASA Technical Reports Server (NTRS)

    Baldwin, K. M.; Herrick, R. E.; McCue, S. A.

    1993-01-01

    A study was conducted, as part of the integrated National Aeronautics and Space Administration Space Life Sciences 1 mission flown in June of 1991, to ascertain the effects of 9 days of exposure to zero gravity on the capacity of rodent skeletal muscle fiber types to oxidize either [14C]pyruvate or [14C]palmitate under state 3 metabolic conditions, i.e., nonlimiting amounts of substrate and cofactors. In addition, activity levels of marker enzymes of the tricarboxylic acid cycle, malate shuttle, and beta-oxidation were measured. Results showed that significant differences in muscle weight occurred in both the predominantly slow vastus intermedius and predominantly fast vastus lateralis of flight vs. control groups (P < 0.05). Total protein content of the muscle samples was similar between groups. Both pyruvate oxidation capacity and the marker oxidative enzymes were not altered in the flight relative to control animals. However, the capacity to oxidize long-chain fatty acids was significantly reduced by 37% in both the high- and low-oxidative regions of the vastus muscle (P < 0.05). Although these findings of a selective reduction in fatty acid oxidation capacity in response to spaceflight are surprising, they are consistent with previous findings showing 1) an increased capacity to take up glucose and upregulate glucose transporter proteins and 2) a marked accumulation of triglycerides in the skeletal muscles of rats subjected to states of unloading. Thus, skeletal muscle of animals exposed to non-weight-bearing environments undergo subcellular transformations that may preferentially bias energy utilization to carbohydrates.

  1. Chemical composition, oxidative stability and antioxidant capacity of oil extracted from roasted seeds of Sacha-inchi (Plukenetia volubilis L.).

    PubMed

    Cisneros, Fausto H; Paredes, Daniel; Arana, Adrian; Cisneros-Zevallos, Luis

    2014-06-01

    The effect of roasting of Sacha-inchi (Plukenetia volubilis L.) seeds on the oxidative stability and composition of its oil was investigated. The seeds were subjected to light, medium and high roasting intensities. Oil samples were subjected to high-temperature storage at 60 °C for 30 days and evaluated for oxidation (peroxide value and p-anisidine), antioxidant activity (total phenols and DPPH assay), and composition (tocopherol content and fatty acid profile). Results showed that roasting partially increased oil oxidation and its antioxidant capacity, slightly decreased tocopherol content, and did not affect the fatty acid profile. During storage, oxidation increased for all oil samples, but at a slower rate for oils from roasted seeds, likely due to its higher antioxidant capacity. Also, tocopherol content decreased significantly, and a slight modification of the fatty acid profile suggested that α-linolenic acid oxidized more readily than other fatty acids present. PMID:24823227

  2. Human mitochondrial oxidative capacity is acutely impaired following burn trauma

    PubMed Central

    Cree, Melanie G.; Fram, Ricki Y.; Herndon, David N.; Qian, Ting; Angel, Carlos; Green, Justin M.; Mlcak, Ronald; Aarsland, Asle; Wolfe, Robert R.

    2008-01-01

    Background Mitochondrial proteins and genes are damaged after burn injury in animals but have not previously been assessed in human burn patients. Methods The rates of maximal muscle mitochondrial oxidative capacity(ATP production) and uncoupled oxidation(heat production) for both palmitate and pyruvate were measured in muscle biopsies from 40 children sustaining burns >40% body surface area and from 13 healthy children controls. Results Maximal mitochondrial oxidation of pyruvate and palmitate were reduced in burn patients compared to controls (4.0±0.2:1.9±0.1 µmolO2/citrate synthase activity/mg protein/min pyruvate; Control:Burn;P<0.001 and 3.0±0.1:0.9±0.03 µmolO2/citrate synthase activity/mg protein/min palmatyl CoA; Control:Burn;P=0.003). Uncoupled oxidation was the same between groups. Conclusions The maximal coupled mitochondrial oxidative capacity is severely impaired after burn injury, although there are no alterations in the rate of uncoupled oxidative capacity. It may be that the ratio of these indicates that a larger portion of energy production in trauma patients is wasted through uncoupling, rather than used for healing. PMID:18639661

  3. Antioxidant capacity of foods for scavenging reactive oxidants and inhibition of plasma lipid oxidation induced by multiple oxidants.

    PubMed

    Niki, Etsuo

    2016-05-18

    Unregulated oxidation of biological molecules induced by multiple oxidants has been implicated in the pathogenesis of various diseases. Consequently, the effects of antioxidants contained in foods, beverages and supplements on the maintenance of health and prevention of diseases have attracted much attention of the public as well as scientists. However, recent human studies have shown inconsistent results and failed to demonstrate the beneficial effects of antioxidants. The mechanisms and dynamics of antioxidant action and assessment of antioxidant capacity have been the subject of extensive studies and arguments. In the present article, the antioxidant capacity has been reviewed focusing on two main issues: the capacity of antioxidants to scavenge multiple reactive oxidants and to inhibit plasma lipid oxidation induced by different biological oxidants. It is emphasized that the capacity of antioxidants to scavenge reactive oxidants does not always correlate linearly with the capacity to inhibit lipid oxidation and that it is necessary to specify the oxidant to assess the efficacy of antioxidants, since multiple oxidants contribute to oxidative damage in vivo and the effects of antioxidants depend on the nature of oxidants. A convenient and rapid method using a microplate reader is discussed for assessing the antioxidant capacity against plasma lipid oxidation induced by multiple oxidants including peroxyl radicals, peroxynitrite, hypochlorite, 15-lipoxygenase, and singlet oxygen. PMID:27090496

  4. Atmospheric oxidation capacity sustained by a tropical forest.

    PubMed

    Lelieveld, J; Butler, T M; Crowley, J N; Dillon, T J; Fischer, H; Ganzeveld, L; Harder, H; Lawrence, M G; Martinez, M; Taraborrelli, D; Williams, J

    2008-04-10

    Terrestrial vegetation, especially tropical rain forest, releases vast quantities of volatile organic compounds (VOCs) to the atmosphere, which are removed by oxidation reactions and deposition of reaction products. The oxidation is mainly initiated by hydroxyl radicals (OH), primarily formed through the photodissociation of ozone. Previously it was thought that, in unpolluted air, biogenic VOCs deplete OH and reduce the atmospheric oxidation capacity. Conversely, in polluted air VOC oxidation leads to noxious oxidant build-up by the catalytic action of nitrogen oxides (NO(x) = NO + NO2). Here we report aircraft measurements of atmospheric trace gases performed over the pristine Amazon forest. Our data reveal unexpectedly high OH concentrations. We propose that natural VOC oxidation, notably of isoprene, recycles OH efficiently in low-NO(x) air through reactions of organic peroxy radicals. Computations with an atmospheric chemistry model and the results of laboratory experiments suggest that an OH recycling efficiency of 40-80 per cent in isoprene oxidation may be able to explain the high OH levels we observed in the field. Although further laboratory studies are necessary to explore the chemical mechanism responsible for OH recycling in more detail, our results demonstrate that the biosphere maintains a remarkable balance with the atmospheric environment. PMID:18401407

  5. INFLUENCE OF AQUEOUS ALUMINUM AND ORGANIC ACIDS ON MEASUREMENT OF ACID NEUTRALIZING CAPACITY IN SURFACE WATERS

    EPA Science Inventory

    Acid neutralizing capacity (ANC) is used to quantify the acid-base status of surface waters. Acidic waters have bean defined as having ANC values less than zero, and acidification is often quantified by decreases in ANC. Measured and calculated values of ANC generally agree, exce...

  6. Skeletal Muscle Oxidative Capacity in Patients with Cystic Fibrosis

    PubMed Central

    Erickson, Melissa L.; Seigler, Nichole; McKie, Kathleen T.; McCully, Kevin K.; Harris, Ryan A.

    2016-01-01

    Introduction Exercise intolerance predicts mortality in patients with cystic fibrosis (CF); however, the mechanisms have yet to be fully elucidated. Using near infrared spectroscopy (NIRS), this study compared skeletal muscle oxidative capacity in patients with CF to healthy controls. Methods Thirteen patients and 16 demographically-matched controls participated in this study. NIRS was utilized to measure the recovery rate of oxygen consumption (musVO2max) of the vastus lateralis muscle after 15 s of electrical stimulation (4 Hz) and subsequent repeated transient arterial occlusions. Results musVO2max was reduced in patients with CF (1.82 ± 0.4 min−1) compared to controls (2.13 ± 0.5 min−1, p = 0.04). A significant inverse relationship between age and musVO2max was observed in patients (r = −0.676, p = 0.011), but not controls (r = −0.291, p = 0.274). Discussion Patients with CF exhibit a reduction in skeletal muscle oxidative capacity compared to controls. It appears as the reduced skeletal muscle oxidative capacity is accelerated by age and could likely contribute to exercise intolerance in patients with CF. PMID:25758606

  7. Maximal oxidative capacity during exercise is associated with skeletal muscle fuel selection and dynamic changes in mitochondrial protein acetylation

    PubMed Central

    Overmyer, Katherine A.; Evans, Charles R.; Qi, Nathan R.; Minogue, Catherine E.; Carson, Joshua J.; Chermside-Scabbo, Christopher J.; Koch, Lauren G.; Britton, Steven L.; Pagliarini, David J.; Coon, Joshua J.; Burant, Charles F.

    2015-01-01

    Summary Maximal exercise-associated oxidative capacity is strongly correlated with health and longevity in humans. Rats selectively bred for high running capacity (HCR) have improved metabolic health and are longer-lived than their low capacity counterparts (LCR). Using metabolomic and proteomic profiling, we show that HCR efficiently oxidize fatty acids (FA) and branched-chain amino acid (BCAA), sparing glycogen and reducing accumulation of short- and medium-chain acylcarnitines. HCR mitochondria have reduced acetylation of mitochondrial proteins within oxidative pathways at rest, and there is rapid protein deacetylation with exercise, which is greater in HCR than LCR. Fluxomic analysis of valine degradation with exercise demonstrates a functional role of differential protein acetylation in HCR and LCR. Our data suggest efficient FA and BCAA utilization contribute to high intrinsic exercise capacity and the health and longevity benefits associated with enhanced fitness. PMID:25738461

  8. An Acidity Scale for Binary Oxides.

    ERIC Educational Resources Information Center

    Smith, Derek W.

    1987-01-01

    Discusses the classification of binary oxides as acidic, basic, or amphoteric. Demonstrates how a numerical scale for acidity/basicity of binary oxides can be constructed using thermochemical data for oxoacid salts. Presents the calculations derived from the data that provide the numeric scale values. (TW)

  9. Acid neutralisation capacity of accelerated carbonated stainless steel slag.

    PubMed

    Johnson, D C; MacLeod, C L; Hills, C D

    2003-05-01

    The acid neutralisation capacity test is widely used to assess the long-term performance of waste materials prior to disposal. Samples of fixed mass are exposed to increasing additions of nitric add in sealed containers and the resultant pH is plotted as a titration curve. In this work, the add neutralisation capacity test was used in the assessment of an accelerated carbonated stainless steel slag. Difficulties arose in applying the test procedure to this material. This was largely because of the raised pressure from significant volumes of released carbon dioxide trapped in the sealed sample containers, causing an alteration to leachate pH values. Consequently, the add neutralisation capacity test was modified to enable testing of samples in equilibrium with the atmosphere. No adverse effects on the results from testing of a carbonate free material were recorded. PMID:12803247

  10. Total oxidant scavenging capacity of Euterpe oleracea Mart. (açaí) seeds and identification of their polyphenolic compounds.

    PubMed

    Rodrigues, Roberta B; Lichtenthäler, Ramona; Zimmermann, Benno F; Papagiannopoulos, Menelaos; Fabricius, Heinz; Marx, Friedhelm; Maia, José G S; Almeida, Ossalin

    2006-06-14

    The antioxidant capacity of methanol and ethanol seed extracts from Euterpe oleracea Mart. (açaí) against the reactive oxygen species (ROS) peroxyl radicals, peroxynitrite, and hydroxyl radicals was studied with the total oxidant scavenging capacity (TOSC) assay in a modified and automated version. Cold methanol digestion was the most efficient extraction method with respect to the antioxidant capacity. The extracts exhibit good antioxidant capacity against peroxyl radicals, similar to the capacity of the pulp. The antioxidant capacity against peroxynitrite and hydroxyl radicals is even higher. The main antioxidants identified by HPLC-MS and HPLC-CEAD are five different procyanidins (di- through pentamers); furthermore, protocatechuic acid and epicatechin were identified as minor compounds. Determination of TOSC values of HPLC seed extract fractions indicates that the procyanidins contribute substantially to the overall antioxidant capacity. In addition, however, other compounds that have not yet been identified are responsible for a large part of the observed antioxidant capacity. PMID:16756342

  11. Heat capacity, enthalpy and entropy of ternary bismuth tantalum oxides

    SciTech Connect

    Leitner, J.; Jakes, V.; Sofer, Z.; Sedmidubsky, D.; Ruzicka, K.; Svoboda, P.

    2011-02-15

    Heat capacity and enthalpy increments of ternary bismuth tantalum oxides Bi{sub 4}Ta{sub 2}O{sub 11}, Bi{sub 7}Ta{sub 3}O{sub 18} and Bi{sub 3}TaO{sub 7} were measured by the relaxation time method (2-280 K), DSC (265-353 K) and drop calorimetry (622-1322 K). Temperature dependencies of the molar heat capacity in the form C{sub pm}=445.8+0.005451T-7.489x10{sup 6}/T{sup 2} J K{sup -1} mol{sup -1}, C{sub pm}=699.0+0.05276T-9.956x10{sup 6}/T{sup 2} J K{sup -1} mol{sup -1} and C{sub pm}=251.6+0.06705T-3.237x10{sup 6}/T{sup 2} J K{sup -1} mol{sup -1} for Bi{sub 3}TaO{sub 7}, Bi{sub 4}Ta{sub 2}O{sub 11} and for Bi{sub 7}Ta{sub 3}O{sub 18}, respectively, were derived by the least-squares method from the experimental data. The molar entropies at 298.15 K, S{sup o}{sub m}(298.15 K)=449.6{+-}2.3 J K{sup -1} mol{sup -1} for Bi{sub 4}Ta{sub 2}O{sub 11}, S{sup o}{sub m}(298.15 K)=743.0{+-}3.8 J K{sup -1} mol{sup -1} for Bi{sub 7}Ta{sub 3}O{sub 18} and S{sup o}{sub m}(298.15 K)=304.3{+-}1.6 J K{sup -1} mol{sup -1} for Bi{sub 3}TaO{sub 7}, were evaluated from the low-temperature heat capacity measurements. -- Graphical Abstract: Temperature dependence of {Delta}{sub ox}C{sub pm} for bismuth tantalum mixed oxides. Display Omitted Research highlights: > Heat capacity, enthalpy and entropy of ternary bismuth tantalum oxides Bi{sub 4}Ta{sub 2}O{sub 11}, Bi{sub 7}Ta{sub 3}O{sub 18} and Bi{sub 3}TaO{sub 7}. > Heat capacity by DSC calorimetry and heat-pulsed calorimetry. > Enthalpy increments by drop calorimetry. > Einstein-Debye model for low-temperature dependence of the heat capacity. > Application of Neumann-Kopp rule.

  12. Surface and bulk modified high capacity layered oxide cathodes with low irreversible capacity loss

    NASA Technical Reports Server (NTRS)

    Manthiram, Arumugam (Inventor); Wu, Yan (Inventor)

    2010-01-01

    The present invention includes compositions, surface and bulk modifications, and methods of making of (1-x)Li[Li.sub.1/3Mn.sub.2/3]O.sub.2.xLi[Mn.sub.0.5-yNi.sub.0.5-yCo.sub.2- y]O.sub.2 cathode materials having an O3 crystal structure with a x value between 0 and 1 and y value between 0 and 0.5, reducing the irreversible capacity loss in the first cycle by surface modification with oxides and bulk modification with cationic and anionic substitutions, and increasing the reversible capacity to close to the theoretical value of insertion/extraction of one lithium per transition metal ion (250-300 mAh/g).

  13. Surface and bulk modified high capacity layered oxide cathodes with low irreversible capacity loss

    DOEpatents

    Manthiram, Arumugam; Wu, Yan

    2010-03-16

    The present invention includes compositions, surface and bulk modifications, and methods of making of (1-x)Li[Li.sub.1/3Mn.sub.2/3]O.sub.2.xLi[Mn.sub.0.5-yNi.sub.0.5-yCo.sub.2- y]O.sub.2 cathode materials having an O3 crystal structure with a x value between 0 and 1 and y value between 0 and 0.5, reducing the irreversible capacity loss in the first cycle by surface modification with oxides and bulk modification with cationic and anionic substitutions, and increasing the reversible capacity to close to the theoretical value of insertion/extraction of one lithium per transition metal ion (250-300 mAh/g).

  14. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    PubMed Central

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  15. Effect Of Oxidation On Chromium Leaching And Redox Capacity Of Slag-Containing Waste Forms

    SciTech Connect

    Almond, P. M.; Stefanko, D. B.; Langton, C. A.

    2013-03-01

    (III) in solution) performed on depth discrete samples could not be correlated with the amount of chromium leached from the depth discrete subsamples or with the oxidation front inferred from soluble chromium (i.e., effective Cr oxidation front). Exposure to oxygen (air or oxygen dissolved in water) results in the release of chromium through oxidation of Cr(III) to highly soluble chromate, Cr(VI). Residual reduction capacity in the oxidized region of the test samples indicates that the remaining reduction capacity is not effective in re-reducing Cr(VI) in the presence of oxygen. Consequently, this method for determining reduction capacity may not be a good indicator of the effective contaminant oxidation rate in a relatively porous solid (40 to 60 volume percent porosity). The chromium extracted in depth discrete samples ranged from a maximum of about 5.8 % at about 5 mm (118 day exposure) to about 4 % at about 10 mm (302 day exposure). The use of reduction capacity as an indicator of long-term performance requires further investigation. The carbonation front was also estimated to have advanced to at least 28 mm in 302 days based on visual observation of gas evolution during acid addition during the reduction capacity measurements. Depth discrete sampling of materials exposed to realistic conditions in combination with short term leaching of crushed samples has potential for advancing the understanding of factors influencing performance and will support conceptual model development.

  16. Acid monolayer functionalized iron oxide nanoparticle catalysts

    NASA Astrophysics Data System (ADS)

    Ikenberry, Myles

    Superparamagnetic iron oxide nanoparticle functionalization is an area of intensely active research, with applications across disciplines such as biomedical science and heterogeneous catalysis. This work demonstrates the functionalization of iron oxide nanoparticles with a quasi-monolayer of 11-sulfoundecanoic acid, 10-phosphono-1-decanesulfonic acid, and 11-aminoundecanoic acid. The carboxylic and phosphonic moieties form bonds to the iron oxide particle core, while the sulfonic acid groups face outward where they are available for catalysis. The particles were characterized by thermogravimetric analysis (TGA), transmission electron microscopy (TEM), potentiometric titration, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectrometry (XPS), and dynamic light scattering (DLS). The sulfonic acid functionalized particles were used to catalyze the hydrolysis of sucrose at 80° and starch at 130°, showing a higher activity per acid site than the traditional solid acid catalyst Amberlyst-15, and comparing well against results reported in the literature for sulfonic acid functionalized mesoporous silicas. In sucrose catalysis reactions, the phosphonic-sulfonic nanoparticles (PSNPs) were seen to be incompletely recovered by an external magnetic field, while the carboxylic-sulfonic nanoparticles (CSNPs) showed a trend of increasing activity over the first four recycle runs. Between the two sulfonic ligands, the phosphonates produced a more tightly packed monolayer, which corresponded to a higher sulfonic acid loading, lower agglomeration, lower recoverability through application of an external magnetic field, and higher activity per acid site for the hydrolysis of starch. Functionalizations with 11-aminoundecanoic acid resulted in some amine groups binding to the surfaces of iron oxide nanoparticles. This amine binding is commonly ignored in iron oxide

  17. Oxidative stress and antioxidant capacity of a terrestrially hibernating hatchling turtle.

    PubMed

    Baker, Patrick J; Costanzo, Jon P; Lee, Richard E

    2007-11-01

    Hatchlings of the painted turtle, Chrysemys picta, hibernate terrestrially and can survive subfreezing temperatures by supercooling or by tolerating the freezing of their tissues. Whether supercooled or frozen, an ischemic hypoxia develops because tissue perfusion is limited by low temperature and/or freezing. Oxidative stress can occur if hatchlings lack sufficient antioxidant defenses to minimize or prevent damage by reactive oxygen species. We examined the antioxidant capacity and indices of oxidative damage in hatchling C. picta following survivable, 48 h bouts of supercooling (-6 degrees C), freezing (-2.5 degrees C), or hypoxia (4 degrees C). Samples of plasma, brain, and liver were collected after a 24 h period of recovery (4 degrees C) and assayed for Trolox-equivalent antioxidant capacity (TEAC), thiobarbituric acid reactive substances (TBARS), and carbonyl proteins. Antioxidant capacity did not vary among treatments in any of the tissues studied. We found a significant increase in TBARS in plasma, but not in the brain or liver, of frozen/thawed hatchlings as compared to untreated controls. No changes were found in the concentration of TBARS or carbonyl proteins in supercooled or hypoxia-exposed hatchlings. Our results suggest that hatchling C. picta have a well-developed antioxidant defense system that minimizes oxidative damage during hibernation. PMID:17639415

  18. Humic acids as electron acceptors for anaerobic microbial oxidation of vinyl chloride and dichloroethene

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.; Lovley, D.R.

    1998-01-01

    Anaerobic oxidation of [1,2-14C]vinyl chloride and [1,2- 14C]dichloroethene to 14CO2 under humic acid-reducing conditions was demonstrated. The results indicate that waterborne contaminants can be oxidized by using humic acid compounds as electron acceptors and suggest that natural aquatic systems have a much larger capacity for contaminant oxidation than previously thought.

  19. Humic acids as electron acceptors for anaerobic microbial oxidation of vinyl chloride and dichloroethane

    SciTech Connect

    Bradley, P.M.; Chapelle, F.H.; Lovley, D.R.

    1998-08-01

    Anaerobic oxidation of [1,2-{sup 14}C]vinyl chloride and [1,2-{sup 14}C]dichloroethene to {sup 14}CO{sub 2} under humic acid-reducing conditions was demonstrated. The results indicate that waterborne contaminants can be oxidized by using humic acid compounds as electron acceptors and suggest that natural aquatic systems have a much larger capacity for contaminant oxidation than previously thought.

  20. Seasonal cycles of mitochondrial ADP sensitivity and oxidative capacities in trout oxidative muscle.

    PubMed

    Guderley, H; St Pierre, J

    1999-10-01

    Mitochondria from red myotomal muscle of rainbow trout, Oncorhynchus mykiss, showed seasonal cycles of their maximal rates of substrate oxidation (nmol.min-1 mg-1 mitochondrial protein) and their apparent ADP affinity (Kmapp), as well as in the thermal sensitivity of these properties. Increases in the maximal capacity of pyruvate oxidation were sufficient to compensate for seasonal changes in temperature, except during the winter months when rates at habitat temperature were depressed relative to other periods. The ADP affinity of isolated mitochondria was highest during cold months. Thus, the Kmapp for ADP at habitat temperature showed less seasonal variation than the ADP Kmapp at a given temperature. A loss in ADP affinity with decreasing temperature occurred through much of the year, and only was definitively suppressed in December and July. Both the ADP affinity and the maximal oxidative capacities of muscle mitochondria seem to be regulated parameters. PMID:10595316

  1. Fatty acid oxidation and ketogenesis in astrocytes

    SciTech Connect

    Auestad, N.

    1988-01-01

    Astrocytes were derived from cortex of two-day-old rat brain and grown in primary culture to confluence. The metabolism of the fatty acids, octanoate and palmitate, to CO{sub 2} in oxidative respiration and to the formation of ketone bodies was examined by radiolabeled tracer methodology. The net production of acetoacetate was also determined by measurement of its mass. The enzymes in the ketogenic pathway were examined by measuring enzymic activity and/or by immunoblot analyses. Labeled CO{sub 2} and labeled ketone bodies were produced from the oxidation of fatty acids labeled at carboxy- and {omega}-terminal carbons, indicating that fatty acids were oxidized by {beta}-oxidation. The results from the radiolabeled tracer studies also indicated that a substantial proportion of the {omega}-terminal 4-carbon unit of the fatty acids bypassed the {beta}-ketothiolase step of the {beta}-oxidation pathway. The ({sup 14}C)acetoacetate formed from the (1-{sup 14}C)labeled fatty acids, obligated to pass through the acetyl-CoA pool, contained 50% of the label at carbon 3 and 50% at carbon 1. In contrast, the ({sup 14}C)acetoacetate formed from the ({omega}-1)labeled fatty acids contained 90% of the label at carbon 3 and 10% at carbon 1.

  2. Evaluation of the total oxidant scavenging capacity of saponins isolated from Platycodon grandiflorum.

    PubMed

    Ryu, Chang Seon; Kim, Chung Hyeon; Lee, Sang Yoon; Lee, Kye Sook; Choung, Kyu Jin; Song, Gyu Yong; Kim, Bong-Hee; Ryu, Shi Yong; Lee, Hyun Sun; Kim, Sang Kyum

    2012-05-01

    The antioxidant activity of saponins isolated from Platycodon grandiflorum (PG; Balloon flower) was determined using the total oxidant-scavenging capacity (TOSC) assay. Platycodigenin, polygalacic acid, platycodin D, platycoside E and deapioplatycoside E were isolated and their structures were characterised based on their physical and spectral properties and by comparison of these results with similar data in the literature. Platycodin D showed the greatest TOSC value against peroxyl radicals, followed (in decreasing order) by polygalacic acid, platycodigenin, deapioplatycosides E and platycoside E. Although the TOSC value of the saponins against peroxyl radicals was less than that of glutathione (GSH) and Trolox used as positive controls. However, TOSC value of platycodigenin, deapioplatycoside E, platycodin D or platycoside E against peroxynitrite was 2.35-, 1.27-, 1.02- or 0.75-fold of GSH, respectively, while polygalacic acid exhibited no scavenging capacity of peroxynitrites. These results suggest importance of the presence of hydroxyl group at carbon 24 in platycodigenin in peroxynitrite scavenging. As the number of attached sugar residues in the saponin glycosides is increased, the scavenging capacity of peroxyl radical, but not peroxynitrite was significantly decreased. These results showed that PG saponins have potent antioxidant activities, which is different according to the structure of aglycones and the number of attached sugar residues. PMID:26434298

  3. Potential impact of microbial activity on the oxidant capacity and organic carbon budget in clouds.

    PubMed

    Vaïtilingom, Mickael; Deguillaume, Laurent; Vinatier, Virginie; Sancelme, Martine; Amato, Pierre; Chaumerliac, Nadine; Delort, Anne-Marie

    2013-01-01

    Within cloud water, microorganisms are metabolically active and, thus, are expected to contribute to the atmospheric chemistry. This article investigates the interactions between microorganisms and the reactive oxygenated species that are present in cloud water because these chemical compounds drive the oxidant capacity of the cloud system. Real cloud water samples with contrasting features (marine, continental, and urban) were taken from the puy de Dôme mountain (France). The samples exhibited a high microbial biodiversity and complex chemical composition. The media were incubated in the dark and subjected to UV radiation in specifically designed photo-bioreactors. The concentrations of H(2)O(2), organic compounds, and the ATP/ADP ratio were monitored during the incubation period. The microorganisms remained metabolically active in the presence of ()OH radicals that were photo-produced from H(2)O(2). This oxidant and major carbon compounds (formaldehyde and carboxylic acids) were biodegraded by the endogenous microflora. This work suggests that microorganisms could play a double role in atmospheric chemistry; first, they could directly metabolize organic carbon species, and second, they could reduce the available source of radicals through their oxidative metabolism. Consequently, molecules such as H(2)O(2) would no longer be available for photochemical or other chemical reactions, which would decrease the cloud oxidant capacity. PMID:23263871

  4. Potential impact of microbial activity on the oxidant capacity and organic carbon budget in clouds

    NASA Astrophysics Data System (ADS)

    Vaïtilingom, Mickael; Deguillaume, Laurent; Vinatier, Virginie; Sancelme, Martine; Amato, Pierre; Chaumerliac, Nadine; Delort, Anne-Marie

    2013-01-01

    Within cloud water, microorganisms are metabolically active and, thus, are expected to contribute to the atmospheric chemistry. This article investigates the interactions between microorganisms and the reactive oxygenated species that are present in cloud water because these chemical compounds drive the oxidant capacity of the cloud system. Real cloud water samples with contrasting features (marine, continental, and urban) were taken from the puy de Dôme mountain (France). The samples exhibited a high microbial biodiversity and complex chemical composition. The media were incubated in the dark and subjected to UV radiation in specifically designed photo-bioreactors. The concentrations of H2O2, organic compounds, and the ATP/ADP ratio were monitored during the incubation period. The microorganisms remained metabolically active in the presence of ●OH radicals that were photo-produced from H2O2. This oxidant and major carbon compounds (formaldehyde and carboxylic acids) were biodegraded by the endogenous microflora. This work suggests that microorganisms could play a double role in atmospheric chemistry; first, they could directly metabolize organic carbon species, and second, they could reduce the available source of radicals through their oxidative metabolism. Consequently, molecules such as H2O2 would no longer be available for photochemical or other chemical reactions, which would decrease the cloud oxidant capacity.

  5. Acid-permanganate oxidation of potassium tetraphenylboron

    SciTech Connect

    Smith, J.R.

    1993-02-01

    Scoping experiments have been performed which show that potassium tetraphenylboron (KTPB) is rapidly oxidized by permanganate in acidic solutions at room temperature. The main Products are CO{sub 2}, highly oxidized organic compounds related to tartaric and tartronic acids, boric acid, and potassium phosphate (when phosphoric acid is used as the source of acid). One liter of 0.6M NaMnO{sub 4}/2.5M H{sub 3}PO{sub 4} solution will destroy up to 8 grams of KTPB. The residual benzene concentration has been measured to be less than the RCRA limit of 0.5 ppm. Approximately 30% of the organic material is released as CO{sub 2} (trace CO) and 0.16% as benzene vapor. The reaction is well behaved, no foaming or spattering. Tests were performed from .15M to near 1M permanganate. The phosphoric acid concentration was maintained at a concentration at least three times that of the permanganate since an excess of acid was desired and this is the ratio that these two reagents are consumed in the oxidation.

  6. Acid-permanganate oxidation of potassium tetraphenylboron

    SciTech Connect

    Smith, J.R.

    1993-02-01

    Scoping experiments have been performed which show that potassium tetraphenylboron (KTPB) is rapidly oxidized by permanganate in acidic solutions at room temperature. The main Products are CO[sub 2], highly oxidized organic compounds related to tartaric and tartronic acids, boric acid, and potassium phosphate (when phosphoric acid is used as the source of acid). One liter of 0.6M NaMnO[sub 4]/2.5M H[sub 3]PO[sub 4] solution will destroy up to 8 grams of KTPB. The residual benzene concentration has been measured to be less than the RCRA limit of 0.5 ppm. Approximately 30% of the organic material is released as CO[sub 2] (trace CO) and 0.16% as benzene vapor. The reaction is well behaved, no foaming or spattering. Tests were performed from .15M to near 1M permanganate. The phosphoric acid concentration was maintained at a concentration at least three times that of the permanganate since an excess of acid was desired and this is the ratio that these two reagents are consumed in the oxidation.

  7. Abnormal skeletal muscle oxidative capacity after lung transplantation by 31P-MRS.

    PubMed

    Evans, A B; Al-Himyary, A J; Hrovat, M I; Pappagianopoulos, P; Wain, J C; Ginns, L C; Systrom, D M

    1997-02-01

    Although lung transplantation improves exercise capacity by removal of a ventilatory limitation, recipients' postoperative maximum oxygen uptake (VO2max) remains markedly abnormal. To determine if abnormal skeletal muscle oxidative capacity contributes to this impaired aerobic capacity, nine lung transplant recipients and eight healthy volunteers performed incremental quadriceps exercise to exhaustion with simultaneous measurements of pulmonary gas exchange, minute ventilation, blood lactate, and quadriceps muscle pH and phosphorylation potential by 31P-magnetic resonance spectroscopy (31P-MRS). Five to 38 mo after lung transplantation, peak VO2 was decreased compared with that of normal control subjects (6.7 +/- 0.4 versus 12.3 +/- 1.0 ml/min/kg, p < 0.001), even after accounting for differences in age and lean body weight. Neither ventilation, arterial O2 saturation nor mild anemia could account for the decrease in aerobic capacity. Quadriceps muscle intracellular pH (pH(i)) was more acidic at rest (7.07 +/- 0.01 versus 7.12 +/- 0.01 units, p < 0.05) and fell during exercise from baseline values at a lower metabolic rate (282 +/- 21 versus 577 +/- 52 ml/min, p < 0.001). Regressions for pH(i) versus VO2, phosphocreatine/inorganic phosphate ratio (PCr/Pi) versus VO2, and blood lactate versus pH(i) were not different. Among transplant recipients, the metabolic rate at which pH(i) fell correlated closely with VO2max (r = 0.87, p < 0.01). The persistent decrease in VO2max after lung transplantation may be related to abnormalities of skeletal muscle oxidative capacity. PMID:9032203

  8. Synthesis and Evaluation of the Anti-Oxidant Capacity of Curcumin Glucuronides, the Major Curcumin Metabolites

    PubMed Central

    Choudhury, Ambar K.; Raja, Suganya; Mahapatra, Sanjata; Nagabhushanam, Kalyanam; Majeed, Muhammed

    2015-01-01

    Curcumin metabolites namely curcumin monoglucuronide and curcumin diglucuronide were synthesized using an alternative synthetic approach. The anti-oxidant potential of these curcumin glucuronides was compared with that of curcumin using DPPH scavenging method and Oxygen Radical Absorbance Capacity (ORAC) assay. The results show that curcumin monoglucuronide exhibits 10 fold less anti-oxidant activity (DPPH method) and the anti-oxidant capacity of curcumin diglucuronide is highly attenuated compared to the anti-oxidant activity of curcumin. PMID:26783957

  9. Combined atmospheric oxidant capacity and increased levels of exhaled nitric oxide

    NASA Astrophysics Data System (ADS)

    Yang, Changyuan; Li, Huichu; Chen, Renjie; Xu, Wenxi; Wang, Cuicui; Tse, Lap Ah; Zhao, Zhuohui; Kan, Haidong

    2016-07-01

    Nitrogen dioxide and ozone are two interrelated oxidative pollutants in the atmosphere. Few studies have evaluated the health effects of combined oxidant capacity (O x ). We investigated the short-term effects of O x on fractional exhaled nitric oxide (FeNO), a well-established biomarker for airway inflammation, in a group of chronic obstructive pulmonary disease patients. Real-time concentrations of O x were obtained by calculating directly the sum of nitrogen dioxide and ozone. Linear mixed-effect models were applied to explore the acute effects of O x on FeNO levels. Short-term exposure to Ox was significantly associated with elevated FeNO. This effect was strongest in the first 24 h after exposure, and was robust to the adjustment of PM2.5. A 10 μg m‑3 increase in 24 h average concentrations of O x was associated with 4.28% (95% confidence interval: 1.19%, 7.37%) increase in FeNO. The effect estimates were statistically significant only among males, elders, and those with body mass index ≥24 kg m‑2, a comorbidity, higher educational attainment, or moderate airflow limitation. This analysis demonstrated an independent effect of O x on respiratory inflammation, and suggested that a single metric O x might serve as a preferable indicator of atmospheric oxidative capacity in further air pollution epidemiological studies.

  10. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    EPA Science Inventory

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2•6H2O functionalization of zeolite. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The adsorption capacity of the adsorbents at 21...

  11. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    EPA Science Inventory

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2•6H2O functionalization of zeolite. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The adsorption capacity of the adsorbents ...

  12. Antioxidant capacity and stability of liposomes containing a triglyceride derivative of lipoic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The multi-functional nutritional agent lipoic acid offers numerous beneficial effects to oxidatively stressed tissues. Lipoic acid was enzymatically incorporated into a triglyceride in conjunction with oleic acid, creating lipoyl dioleoylglycerol, and then chemically reduced to form dihydrolipoyl d...

  13. Reference electrode for strong oxidizing acid solutions

    DOEpatents

    Rigdon, Lester P.; Harrar, Jackson E.; Bullock, Sr., Jack C.; McGuire, Raymond R.

    1990-01-01

    A reference electrode for the measurement of the oxidation-reduction potentials of solutions is especially suitable for oxidizing solutions such as highly concentrated and fuming nitric acids, the solutions of nitrogen oxides, N.sub.2 O.sub.4 and N.sub.2 O.sub.5, in nitric acids. The reference electrode is fabricated of entirely inert materials, has a half cell of Pt/Ce(IV)/Ce(III)/70 wt. % HNO.sub.3, and includes a double-junction design with an intermediate solution of 70 wt. % HNO.sub.3. The liquid junctions are made from Corning No. 7930 glass for low resistance and negligible solution leakage.

  14. Nitro-linolenic acid is a nitric oxide donor.

    PubMed

    Mata-Pérez, Capilla; Sánchez-Calvo, Beatriz; Begara-Morales, Juan C; Carreras, Alfonso; Padilla, María N; Melguizo, Manuel; Valderrama, Raquel; Corpas, Francisco J; Barroso, Juan B

    2016-07-01

    Nitro-fatty acids (NO2-FAs), which are the result of the interaction between reactive nitrogen species (RNS) and non-saturated fatty acids, constitute a new research area in plant systems, and their study has significantly increased. Very recently, the endogenous presence of nitro-linolenic acid (NO2-Ln) has been reported in the model plant Arabidopsis thaliana. In this regard, the signaling role of this molecule has been shown to be key in setting up a defense mechanism by inducing the chaperone network in plants. Here, we report on the ability of NO2-Ln to release nitric oxide (NO) in an aqueous medium with several approaches, such as by a spectrofluorometric probe with DAF-2, the oxyhemoglobin oxidation method, ozone chemiluminescence, and also by confocal laser scanning microscopy in Arabidopsis cell cultures. Jointly, this ability gives NO2-Ln the potential to act as a signaling molecule by the direct release of NO, due to its capacity to induce different changes mediated by NO or NO-related molecules such as nitration and S-nitrosylation or by the electrophilic capacity of these molecules through a nitroalkylation mechanism. PMID:27164295

  15. Assessment of the antioxidant capacity and oxidative stability of esterified phenolic lipids in selected edible oils.

    PubMed

    Aziz, Sarya; Kermasha, Selim

    2014-04-01

    The research work was aimed at the determination of the antioxidant capacity (AOC) and the oxidative stability of phenolic lipids (PLs), obtained by lipase-catalyzed transesterification of phenolic acids (PAs) with selected edible oils (EOs), including flaxseed (FSO), fish liver (FO), and krill (KO) oils. The statistical analyses (Tukey's test at P < 0.05) revealed that the difference in AOC between that of the esterified FSO (EFSO) and the esterified krill oil (EKO) containing PLs and their control trials of EOs was significant (P < 0.05). To evaluate the storage stability, the EOs and their esterified products were subjected to 2 oxidation treatments. The experimental findings showed that the esterified EOs had higher oxidative stability when they were subjected to light, oxygen, and agitation at 50 °C as compared to that of the EOs; however, only the esterified fish oil (EFO) showed a significant difference in its peroxide value, when the esterified EOs were placed in the dark at 25 °C. Overall, the phenolic mono- and diacyglycerols present in the EOs have shown to be potential antioxidants in improving the oxidative stability of the oil and enhancing its AOC. PMID:24611943

  16. Sodium Picosulfate, Magnesium Oxide, and Anhydrous Citric Acid

    MedlinePlus

    ... picosulfate, magnesium oxide, and anhydrous citric acid combination powder is used to empty the colon (large intestine, ... oxide and anhydrous citric acid combine when the powder is mixed with water to form a medication ...

  17. Buffer capacities of podzolic and peat gleyic podzolic soils to sulfuric and nitric acids

    NASA Astrophysics Data System (ADS)

    Kuznetsov, N. B.; Alekseeva, S. A.; Shashkova, G. V.; Dronova, T. Ya.; Sokolova, T. A.

    2007-04-01

    Soil samples from the main genetic horizons of pale podzolic and peat gleyic podzolic soils from the Central Forest Reserve were subjected to a continuous potentiometric titration by sulfuric and nitric acids. The sulfate sorption capacity was determined in soil mineral horizons. The buffer capacity of mineral horizons of both soils to sulfuric acid was found to be higher than that to the nitric acid. This is explained by the sorption of sulfates via the mechanism of ligand exchange with the release of hydroxyl groups from the surfaces of Fe and Al hydroxide particles and edge faces of clay crystallites. The buffer capacity of organic horizons of the pale podzolic soil to sulfuric acid proved to be higher than that to nitric acid; in organic horizons of the peat gleyic podzolic soil, the buffer capacity to sulfuric acid was lower than that to nitric acid. The reasons for this phenomenon have yet to be investigated.

  18. Antioxidant capacity of hydrolyzed animal by-products and relation to amino acid composition and peptide size distribution.

    PubMed

    Damgaard, Trine; Lametsch, René; Otte, Jeanette

    2015-10-01

    The antioxidative capacity of six different tissue hydrolysates (porcine colon, heart and neck and bovine lung, kidney and pancreas) were tested by three different assays monitoring iron chelation, ABTS radical scavenging and inhibition of lipid oxidation in emulsions, respectively. The hydrolysates were also investigated with respect to amino acid composition and peptide size distribution. The hydrolysates contained peptides ranging from 20 kDa to below 100 Da with a predominance of peptides with low molecular weight (53.8 to 89.0 % below 3 kDa). All hydrolysates exhibited antioxidant activity as assessed with all three methods; inhibition of lipid oxidation ranging from 72 to 88 % (at a final protein concentration of 7 mg/mL), iron chelation capacity from 23 to 63 % (at 1.1 mg/mL), and ABTS radical scavenging from 38 to 50 % (at 10 μg /mL). The antioxidant activity did not correlate with the proportion of low molecular weight peptides in the hydrolysed tissues, but with the content of specific amino acid residues. The ABTS radical scavenging capacity of the tissues was found to correlate with the content of Trp, Tyr, Met and Arg, whereas the ability to inhibit the oxidation of lineoleic acid correlated with the content of Glu and His. The chosen animal by-products thus represent a natural source of antioxidants with potential for food application. PMID:26396396

  19. Influence of extractable soil manganese on oxidation capacity of different soils in Korea

    NASA Astrophysics Data System (ADS)

    Chon, Chul-Min; Kim, Jae Gon; Lee, Gyoo Ho; Kim, Tack Hyun

    2008-08-01

    We examined the relationship between soil oxidation capacity and extractable soil manganese, iron oxides, and other soil properties. The Korean soils examined in this study exhibited low to medium Cr oxidation capacities, oxidizing 0.00-0.47 mmol/kg, except for TG-4 soils, which had the highest capacity for oxidizing added Cr(III) [>1.01 mmol/kg of oxidized Cr(VI)]. TG and US soils, with high Mn contents, had relatively high oxidation capacities. The Mn amounts extracted by dithionite-citrate-bicarbonate (DCB) (Mnd), NH2OH·HCl (Mnh), and hydroquinone (Mnr) were generally very similar, except for the YS1 soils, and were well correlated. Only small proportions of either total Mn or DCB-extractable Mn were extracted by NH2OH·HCl and hydroquinone in the YS1 soils, suggesting inclusion of NH2OH·HCl and hydroquinone-resistant Mn oxides, because these extractants are weaker reductants than DCB. No Cr oxidation test results were closely related to total Mn concentrations, but Mnd, Mnh, and Mnr showed a relatively high correlation with the Cr tests ( r = 0.655-0.851; P < 0.01). The concentrations of Mnd and Mnh were better correlated with the Cr oxidation tests than was the Mnr concentration, suggesting that the oxidation capacity of our soil samples can be better explained by Mnd and Mnh than by Mnr. The first component in principal components analysis indicated that extractable soil Mn was a main factor controlling net Cr oxidation in the soils. Total soil Mn, Fe oxides, and the clay fraction are crucial for predicting the mobility of pollutants and heavy metals in soils. The second principal component indicated that the presence of Fe oxides in soils had a significant relationship with the clay fraction and total Mn oxide, and was also related to heavy-metal concentrations (Zn, Cd, and Cu, but not Pb).

  20. Effect of oxidation level on the inclusion capacity and solution stability of oxidized amylose in aqueous solution.

    PubMed

    Zhou, Ying; Li, Xinying; Lv, Yongbo; Shi, Yifeng; Zeng, Yu; Li, Defu; Mu, Changdao

    2016-03-15

    The oxidized amyloses with high oxidation level and carboxyl content were successfully prepared through a two-step oxidation method using hydrogen peroxide as the oxidant and copper sulfate as the catalyst. The results showed that oxidation would prevent the oxidized product to crystallize and induce depolymerization of amylose molecules. Accordingly, the helices and inclusion capacity of oxidized amylose molecules were reduced. However, the solubility of oxidized amyloses in water was highly improved due to the introduced carboxyl groups. The solution stability of oxidized amylose-guest inclusion complexes in aqueous solution was efficiently improved to a large extent. The result suggested that the two-step oxidation method was an efficient way to highly broaden the applications of amylose-guest inclusion complexes in water environment. PMID:26794736

  1. Observations on the methane oxidation capacity of landfill soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field data and two independent models indicate that landfill cover methane (CH4) oxidation should not be considered as a constant 10% or any other single value. Percent oxidation is a decreasing exponential function of the total methane flux rate into the cover and is also dependent on climate and c...

  2. Subclinical mastitis causes alterations in nitric oxide, total oxidant and antioxidant capacity in cow milk.

    PubMed

    Atakisi, Onur; Oral, Hasan; Atakisi, Emine; Merhan, Oguz; Metin Pancarci, S; Ozcan, Ayla; Marasli, Saban; Polat, Bulent; Colak, Armagan; Kaya, Semra

    2010-08-01

    The aim of this study was to investigate total antioxidant (TAC), and oxidant capacity (TOC) and nitric oxide (NO) levels in milk of cows with subclinical mastitis. Brown Swiss and Holstein breed cows were screened with California Mastitis Test (CMT) to determine mammary glands with subclinical mastitis. Moreover, somatic cell counts (SCC) were determined electronically in all milk samples. Mammary quarters were classified as healthy (n=25) or subclinical mastitis (n=35) based on CMT scores and somatic cell count (SCC: < or =200,000/ml or >200,000/ml) in milk. Nitric oxide, TOC and SCC levels were significantly higher (p<0.001, p<0.005 and p<0.001, respectively) in milk from mammary quarters with subclinical mastitis compared to those from healthy mammary quarters. In conclusion, subclinical mastitis results in higher NO concentrations, TOC and SCC, and NO and TOC were positively correlated with SCC. Moreover, alterations in NO levels and TOC in milk could be used as an alternative diagnostic tool to screen for subclinical mastitis. PMID:20132956

  3. Fatty acid oxidation: systems analysis and applications.

    PubMed

    Cintolesi, Angela; Rodríguez-Moyá, María; Gonzalez, Ramon

    2013-01-01

    Fatty acids (FAs) are essential components of cellular structure and energy-generating routes in living organisms. They exist in a variety of chemical configurations and functionalities and are catabolized by different oxidative routes, according to their structure. α- and ω-Oxidation are minor routes that occur only in eukaryotes, while β-oxidation is the major degradation route in eukaroytes and prokaryotes. These pathways have been characterized and engineered from different perspectives for industrial and biomedical applications. The severity of FA oxidation disorders in humans initially guided the study of FA metabolism at a molecular-level. On the other hand, recent advances in metabolic engineering and systems biology have powered the study of FA biosynthetic and catabolic routes in microorganisms at a systems-level. Several studies have proposed these pathways as platforms for the production of fuels and chemicals from biorenewable sources. The lower complexity of microbial systems has allowed a more comprehensive study of FA metabolism and has opened opportunities for a wider range of applications. Still, there is a need for techniques that facilitate the translation of high-throughput data from microorganisms to more complex eukaryotic systems in order to aid the development of diagnostic and treatment strategies for FA oxidation disorders. In addition, further systems biology analyses on human systems could also provide valuable insights on oxidation disorders. This article presents a comparison of the three main FA oxidative routes, systems biology analyses that have been used to study FA metabolism, and engineering efforts performed on microbial systems. PMID:23661533

  4. Preparation of surface modified zinc oxide nanoparticle with high capacity dye removal ability

    SciTech Connect

    Mahmoodi, Niyaz Mohammad; Najafi, Farhood

    2012-07-15

    Highlights: ► Amine-functionalized zinc oxide nanoparticle (AFZON) was synthesized. ► Isotherm and kinetics data followed Langmuir isotherm and pseudo-second order kinetic model, respectively. ► Q{sub 0} of ZON for AB25, DR23 and DR31 was 20, 12 and 15 mg/g, respectively. ► Q{sub 0} of AFZON for AB25, DR23 and DR31 was 1250, 1000 and 1429 mg/g, respectively. ► AFZON was regenerated at pH 12. -- Abstract: In this paper, the surface modification of zinc oxide nanoparticle (ZON) by amine functionalization was studied to prepare high capacity adsorbent. Dye removal ability of amine-functionalized zinc oxide nanoparticle (AFZON) and zinc oxide nanoparticle (ZON) was also investigated. The physical characteristics of AFZON were studied using Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Acid Blue 25 (AB25), Direct Red 23 (DR23) and Direct Red 31 (DR31) were used as model compounds. The effect of operational parameters such as dye concentration, adsorbent dosage, pH and salt on dye removal was evaluated. The isotherm and kinetic of dye adsorption were studied. The maximum dye adsorption capacity (Q{sub 0}) was 20 mg/g AB25, 12 mg/g DR23 and 15 mg/g DR31 for ZON and 1250 mg/g AB25, 1000 mg/g DR23 and 1429 mg/g DR31 for AFZON. It was found that dye adsorption followed Langmuir isotherm. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% AB25, 86% for DR23 and 90% for DR31 were achieved in aqueous solution at pH 12. Based on the data of the present investigation, it can be concluded that the AFZON being an adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored aqueous solutions.

  5. Resistance exercise training and in vitro skeletal muscle oxidative capacity in older adults.

    PubMed

    Flack, Kyle D; Davy, Brenda M; DeBerardinis, Martin; Boutagy, Nabil E; McMillan, Ryan P; Hulver, Matthew W; Frisard, Madlyn I; Anderson, Angela S; Savla, Jyoti; Davy, Kevin P

    2016-07-01

    Whether resistance exercise training (RET) improves skeletal muscle substrate oxidative capacity and reduces mitochondrial production of reactive oxygen species in older adults remains unclear. To address this, 19 older males (≥60 years) were randomized to a RET (n = 11) or to a waitlist control group (n = 8) that remained sedentary for 12 weeks. RET was comprised of three upper body and four lower body movements on resistance machines. One set of 8-12 repetitions to failure of each movement was performed on three nonconsecutive days/week. Improvements in chest press and leg press strength were assessed using a three-repetition maximum (3 RM). Body composition was assessed via dual energy X-ray absorptiometry. Muscle biopsies were obtained from the vastus lateralis muscle at baseline and at both 3 weeks and 12 weeks. Palmitate and pyruvate oxidation rates were measured from the (14)CO2 produced from [1-(14)C] palmitic acid and [U-(14)C] pyruvate, respectively, during incubation of muscle homogenates. PGC-1α, TFAM, and PPARδ levels were quantified using qRT-PCR Citrate synthase (CS) and β-HAD activities were determined spectrophotometrically. Mitochondrial production of reactive oxygen species (ROS) were assessed using the Amplex Red Hydrogen Peroxide/Peroxidase assay. There were no significant changes in body weight or body composition following the intervention. Chest press and leg press strength (3RM) increased ~34% (both P < 0.01) with RET There were no significant changes in pyruvate or fatty acid oxidation or in the expression of target genes with the intervention. There was a modest increase (P < 0.05) in βHAD activity with RET at 12 weeks but the change in CS enzyme activity was not significant. In addition, there were no significant changes in ROS production in either group following RET Taken together, the findings of this study suggest that 12 weeks of low volume RET does not increase skeletal muscle oxidative capacity or reduce ROS

  6. Observations on the methane oxidation capacity of landfill soils.

    PubMed

    Chanton, Jeffrey; Abichou, Tarek; Langford, Claire; Spokas, Kurt; Hater, Gary; Green, Roger; Goldsmith, Doug; Barlaz, Morton A

    2011-05-01

    The objective of this study was to determine the role of CH(4) loading to a landfill cover in the control of CH(4) oxidation rate (gCH(4)m(-2)d(-1)) and CH(4) oxidation efficiency (% CH(4) oxidation) in a field setting. Specifically, we wanted to assess how much CH(4) a cover soil could handle. To achieve this objective we conducted synoptic measurements of landfill CH(4) emission and CH(4) oxidation in a single season at two Southeastern USA landfills. We hypothesized that percent oxidation would be greatest at sites of low CH(4) emission and would decrease as CH(4) emission rates increased. The trends in the experimental results were then compared to the predictions of two differing numerical models designed to simulate gas transport in landfill covers, one by modeling transport by diffusion only and the second allowing both advection and diffusion. In both field measurements and in modeling, we found that percent oxidation is a decreasing exponential function of the total CH(4) flux rate (CH(4) loading) into the cover. When CH(4) is supplied, a cover's rate of CH(4) uptake (gCH(4)m(-2)d(-2)) is linear to a point, after which the system becomes saturated. Both field data and modeling results indicate that percent oxidation should not be considered as a constant value. Percent oxidation is a changing quantity and is a function of cover type, climatic conditions and CH(4) loading to the bottom of the cover. The data indicate that an effective way to increase the % oxidation of a landfill cover is to limit the amount of CH(4) delivered to it. PMID:20889326

  7. SHORT-TERM CHANGES IN THE BASE NEUTRALIZING CAPACITY OF AN ACID ADIRONDACK LAKE, NEW YORK

    EPA Science Inventory

    Concern and controversy over the effects of acidic deposition on low ionic strength surface wa ters has led to much discussion on the nature and extent of proton transformations within acid sensitive ecosystems. The source of base neutralizing capacity(BNC) within acid surface wa...

  8. Obese humans as economically designed feed converters: symmorphosis and low oxidative capacity skeletal muscle.

    PubMed

    Hudson, Nicholas J; Lehnert, Sigrid A; Harper, Gregory S

    2008-01-01

    Human obesity is considered a consequence of a thrifty or economic metabolism. In this hypothesis, we apply an established economic design theory, called symmorphosis, to help explain the known association between obesity and low oxidative capacity skeletal muscle. Symmorphosis reflects an engineering principle, and predicts that physiological systems are most economically designed when unnecessary spare capacity is eliminated. This is because the structural/functional adaptations accounting for spare capacity themselves bear energetic costs of construction, maintenance and load. As oxidation of feed energy occurs in mitochondria, and because skeletal muscle accounts for 30% of resting metabolism, we focus on skeletal muscle mitochondria. In the same way that the most economically designed elevator is supported by a cable that is strong enough, but not too strong, symmorphosis predicts that the most economically designed feed converters should have enough, but not too much mitochondrial oxidative (fuel burning) capacity. While ATP demand is clearly more efficiently met by oxidative (38 molecules of ATP) rather than glycolytic (2 molecules of ATP) metabolism, symmorphosis predicts that having excess oxidative capacity actually reduces feed efficiency. This inefficiency is manifest by having to maintain, ultimately using feed energy, the expensive inner mitochondrial proton gradient in the superfluous mitochondria. On this basis, we predict that established molecular controllers of mitochondrial biogenesis and oxidative capacity such as eNOS, SIN3 co-repressor, TFAM and PPARgamma may yield useful DNA markers and therapeutic targets for issues relating to frugal energetics, namely predisposition to obesity and starvation resilience. PMID:17664046

  9. Proteomic analysis reveals perturbed energy metabolism and elevated oxidative stress in hearts of rats with inborn low aerobic capacity

    PubMed Central

    Burniston, Jatin G.; Kenyani, Jenna; Wastling, Jonathan M.; Burant, Charles F.; Qi, Nathan R.; Koch, Lauren G.; Britton, Steven L.

    2012-01-01

    Selection on running capacity has created rat phenotypes of high capacity runners (HCR) that have enhanced cardiac function and low capacity runners (LCR) that exhibit risk factors of metabolic syndrome. We analysed hearts of HCR and LCR from generation 22 of selection using DIGE and identified proteins from MS database searches. The running capacity of HCR was 6-fold greater than LCR. DIGE resolved 957 spots and proteins were unambiguously identified in 369 spots. Protein expression profiling detected 67 statistically significant (P<0.05; false discovery rate <10 %, calculated using q-values) differences between HCR and LCR. Hearts of HCR rats exhibited robust increases in the abundance of each enzyme of the beta-oxidation pathway. In contrast, LCR hearts were characterised by the modulation of enzymes associated with ketone body or amino acid metabolism. LCR also exhibited enhanced expression of antioxidant enzymes such as catalase and greater phosphorylation of alpha B-crystallin at serine 59, which is a common point of convergence in cardiac stress signalling. Thus proteomic analysis revealed selection on low running capacity is associated with perturbations in cardiac energy metabolism and provided the first evidence that the LCR cardiac proteome is exposed to greater oxidative stress. PMID:21751351

  10. Imaging of myocardial fatty acid oxidation.

    PubMed

    Mather, Kieren J; DeGrado, Timothy R

    2016-10-01

    Myocardial fuel selection is a key feature of the health and function of the heart, with clear links between myocardial function and fuel selection and important impacts of fuel selection on ischemia tolerance. Radiopharmaceuticals provide uniquely valuable tools for in vivo, non-invasive assessment of these aspects of cardiac function and metabolism. Here we review the landscape of imaging probes developed to provide non-invasive assessment of myocardial fatty acid oxidation (MFAO). Also, we review the state of current knowledge that myocardial fatty acid imaging has helped establish of static and dynamic fuel selection that characterizes cardiac and cardiometabolic disease and the interplay between fuel selection and various aspects of cardiac function. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. PMID:26923433

  11. Analysis of the mineral acid-base components of acid-neutralizing capacity in Adirondack Lakes

    NASA Astrophysics Data System (ADS)

    Munson, R. K.; Gherini, S. A.

    1993-04-01

    Mineral acids and bases influence pH largely through their effects on acid-neutralizing capacity (ANC). This influence becomes particularly significant as ANC approaches zero. Analysis of data collected by the Adirondack Lakes Survey Corporation (ALSC) from 1469 lakes throughout the Adirondack region indicates that variations in ANC in these lakes correlate well with base cation concentrations (CB), but not with the sum of mineral acid anion concentrations (CA). This is because (CA) is relatively constant across the Adirondacks, whereas CB varies widely. Processes that supply base cations to solution are ion-specific. Sodium and silica concentrations are well correlated, indicating a common source, mineral weathering. Calcium and magnesium also covary but do not correlate well with silica. This indicates that ion exchange is a significant source of these cations in the absence of carbonate minerals. Iron and manganese concentrations are elevated in the lower waters of some lakes due to reducing conditions. This leads to an ephemeral increase in CB and ANC. When the lakes mix and oxic conditions are restored, these ions largely precipitate from solution. Sulfate is the dominant mineral acid anion in ALSC lakes. Sulfate concentrations are lowest in seepage lakes, commonly about 40 μeq/L less than in drainage lakes. This is due in part to the longer hydraulic detention time in seepage lakes, which allows slow sulfate reduction reactions more time to decrease lake sulfate concentration. Nitrate typically influences ANC during events such as snowmelt. Chloride concentrations are generally low, except in lakes impacted by road salt.

  12. Increased Brown Adipose Tissue Oxidative Capacity in Cold-Acclimated Humans

    PubMed Central

    Blondin, Denis P.; Labbé, Sébastien M.; Tingelstad, Hans C.; Noll, Christophe; Kunach, Margaret; Phoenix, Serge; Guérin, Brigitte; Turcotte, Éric E.; Carpentier, André C.

    2014-01-01

    Context: Recent studies examining brown adipose tissue (BAT) metabolism in adult humans have provided convincing evidence of its thermogenic potential and role in clearing circulating glucose and fatty acids under acute mild cold exposure. In contrast, early indications suggest that BAT metabolism is defective in obesity and type 2 diabetes, which may have important pathological and therapeutic implications. Although many mammalian models have demonstrated the phenotypic flexibility of this tissue through chronic cold exposure, little is known about the metabolic plasticity of BAT in humans. Objective: Our objective was to determine whether 4 weeks of daily cold exposure could increase both the volume of metabolically active BAT and its oxidative capacity. Design: Six nonacclimated men were exposed to 10°C for 2 hours daily for 4 weeks (5 d/wk), using a liquid-conditioned suit. Using electromyography combined with positron emission tomography with [11C]acetate and [18F]fluorodeoxyglucose, shivering intensity and BAT oxidative metabolism, glucose uptake, and volume before and after 4 weeks of cold acclimation were examined under controlled acute cold-exposure conditions. Results: The 4-week acclimation protocol elicited a 45% increase in BAT volume of activity (from 66 ± 30 to 95 ± 28 mL, P < .05) and a 2.2-fold increase in cold-induced total BAT oxidative metabolism (from 0.725 ± 0.300 to 1.591 ± 0.326 mL·s−1, P < .05). Shivering intensity was not significantly different before compared with after acclimation (2.1% ± 0.7% vs 2.0% ± 0.5% maximal voluntary contraction, respectively). Fractional glucose uptake in BAT increased after acclimation (from 0.035 ± 0.014 to 0.048 ± 0.012 min−1), and net glucose uptake also trended toward an increase (from 163 ± 60 to 209 ± 50 nmol·g−1·min−1). Conclusions: These findings demonstrate that daily cold exposure not only increases the volume of metabolically active BAT but also increases its oxidative

  13. Effect of sinter fracture and ohmic resistance on capacity retention in the nickel oxide electrode

    NASA Technical Reports Server (NTRS)

    Lanzi, Oscar; Landau, Uziel

    1991-01-01

    The lifetime of batteries which utilize the nickel oxide electrode is often limited because this electrode loses a significant portion of its capacity as it is cycled. It is asserted that this capacity loss may often be attributed to cracking or separation of the conductive nickel sinter in the electrode, which forces electronic current to pass through the poorly conducting hydrated oxide and thus imposes a significant ohmic resistance. The model indicates that the oxide develops a nearly insulating layer which prevents complete discharge in the cycled electrode at usable rates. The capacity retention can be improved by reducing the cyclic stresses or strengthening the current collecting structure, redistributing it to provide a shorter current path through the solid phase, or by increasing the conductivity of the oxide to delay the formation of an insulating layer.

  14. Factors Affecting Nickel-oxide Electrode Capacity in Nickel-hydrogen Cells

    NASA Technical Reports Server (NTRS)

    Ritterman, P. F.

    1984-01-01

    The nickel-oxide electrode common to the nickel hydrogen and nickel cadmium cell is by design the limiting or capacity determining electrode on both charge and discharge. The useable discharge capacity from this electrode, and since it is the limiting electrode, the useable discharge capacity of the cell as well, can and is optimized by rate of charge, charge temperature and additives to electrode and electrolyte. Recent tests with nickel hydrogen cells and tests performed almost 25 years ago with nickel cadmium cells indicate an improvement of capacity as a result of using increased electrolyte concentration.

  15. The Iron-Catalyzed Oxidation of Hydrazine by Nitric Acid

    SciTech Connect

    Karraker, D.G.

    2001-07-17

    To assess the importance of iron to hydrazine stability, the study of hydrazine oxidation by nitric acid has been extended to investigate the iron-catalyzed oxidation. This report describes those results.

  16. Lipidomics of oxidized polyunsaturated fatty acids

    PubMed Central

    Massey, Karen A.; Nicolaou, Anna

    2013-01-01

    Lipid mediators are produced from the oxidation of polyunsaturated fatty acids through enzymatic and free radical-mediated reactions. When subject to oxygenation via cyclooxygenases, lipoxygenases, and cytochrome P450 monooxygenases, polyunsaturated fatty acids give rise to an array of metabolites including eicosanoids, docosanoids, and octadecanoids. These potent bioactive lipids are involved in many biochemical and signaling pathways, with inflammation being of particular importance. Moreover, because they are produced by more than one pathway and substrate, and are present in a variety of biological milieus, their analysis is not always possible with conventional assays. Liquid chromatography coupled to electrospray mass spectrometry offers a versatile and sensitive approach for the analysis of bioactive lipids, allowing specific and accurate quantitation of multiple species present in the same sample. Here we explain the principles of this approach to mediator lipidomics and present detailed protocols for the assay of enzymatically produced oxygenated metabolites of polyunsaturated fatty acids that can be tailored to answer biological questions or facilitate assessment of nutritional and pharmacological interventions. PMID:22940496

  17. HBOC Vasoactivity: Interplay Between Nitric Oxide Scavenging and Capacity to Generate Bioactive Nitric Oxide Species

    PubMed Central

    Friedman, Joel M.

    2013-01-01

    Abstract Significance: Despite many advances in blood substitute research, the development of materials that are effective in maintaining blood volume and oxygen delivery remains a priority for emergency care and trauma. Clinical trials on hemoglobin (Hb)-based oxygen carriers (HBOCs) have not provided information on the mechanism of toxicity, although all commercial formulations have safety concerns. Specifically, it is important to reconcile the different hypotheses of Hb toxicity, such as nitric oxide (NO) depletion and oxidative reactions, to provide a coherent molecular basis for designing a safe HBOC. Recent Advances: HBOCs with different sizes often exhibit differences in the degree of HBOC-induced vasoactivity. This has been attributed to differences in the degree of NO scavenging and in the extent of Hb extravasation. Additionally, it is appears that Hb can undergo reactions that compensate for NO scavenging by generating bioactive forms of NO. Critical Issues: Engineering modifications to enhance bioactive NO production can result in diminished oxygen delivery by virtue of increased oxygen affinity. This strategy can prevent the HBOC from fulfilling the intended goal on preserving oxygenation; however, the NO production effects will increase perfusion and oxygen transport. Future Directions: Hb modifications influence NO scavenging and the capacity of certain HBOCs to compensate for NO scavenging through nitrite-mediated reactions that generate bioactive NO. Based on the current understanding of these NO-related factors, possible synthetic strategies are presented that address how HBOC formulations can be prepared that: (i) effectively deliver oxygen, (ii) maintain tissue perfusion, and (iii) limit/reverse underlying inflammation within the vasculature. Antioxid. Redox Signal. 18, 2284–2297. PMID:23249305

  18. Effects of an 8-weeks erythropoietin treatment on mitochondrial and whole body fat oxidation capacity during exercise in healthy males.

    PubMed

    Guadalupe-Grau, Amelia; Plenge, Ulla; Helbo, Signe; Kristensen, Marianne; Andersen, Peter Riis; Fago, Angela; Belhage, Bo; Dela, Flemming; Helge, Jørn Wulff

    2015-01-01

    The present investigation was performed to elucidate if the non-erythropoietic ergogenic effect of a recombinant erythropoietin treatment results in an impact on skeletal muscle mitochondrial and whole body fatty acid oxidation capacity during exercise, myoglobin concentration and angiogenesis. Recombinant erythropoietin was administered by subcutaneous injections (5000 IU) in six healthy male volunteers (aged 21 ± 2 years; fat mass 18.5 ± 2.3%) over 8 weeks. The participants performed two graded cycle ergometer exercise tests before and after the intervention where VO2max and maximal fat oxidation were measured. Biopsies of the vastus lateralis muscle were obtained before and after the intervention. Recombinant erythropoietin treatment increased mitochondrial O2 flux during ADP stimulated state 3 respiration in the presence of complex I and II substrates (malate, glutamate, pyruvate, succinate) with additional electron input from β-oxidation (octanoylcarnitine) (from 60 ± 13 to 87 ± 24 pmol · s(-1) · mg(-1) P < 0.01). β-hydroxy-acyl-CoA-dehydrogenase activity was higher after treatment (P < 0.05), whereas citrate synthase activity also tended to increase (P = 0.06). Total myoglobin increased by 16.5% (P < 0.05). Capillaries per muscle area tended to increase (P = 0.07), whereas capillaries per fibre as well as the total expression of vascular endothelial growth factor remained unchanged. Whole body maximal fat oxidation was not increased after treatment. Eight weeks of recombinant erythropoietin treatment increases mitochondrial fatty acid oxidation capacity and myoglobin concentration without any effect on whole body maximal fat oxidation. PMID:25259652

  19. High-Capacity, High-Voltage Composite Oxide Cathode Materials

    NASA Technical Reports Server (NTRS)

    Hagh, Nader M.

    2015-01-01

    This SBIR project integrates theoretical and experimental work to enable a new generation of high-capacity, high-voltage cathode materials that will lead to high-performance, robust energy storage systems. At low operating temperatures, commercially available electrode materials for lithium-ion (Li-ion) batteries do not meet energy and power requirements for NASA's planned exploration activities. NEI Corporation, in partnership with the University of California, San Diego, has developed layered composite cathode materials that increase power and energy densities at temperatures as low as 0 degC and considerably reduce the overall volume and weight of battery packs. In Phase I of the project, through innovations in the structure and morphology of composite electrode particles, the partners successfully demonstrated an energy density exceeding 1,000 Wh/kg at 4 V at room temperature. In Phase II, the team enhanced the kinetics of Li-ion transport and electronic conductivity at 0 degC. An important feature of the composite cathode is that it has at least two components that are structurally integrated. The layered material is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated and deliver a large amount of energy with stable cycling.

  20. Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.

    ERIC Educational Resources Information Center

    Donahue, Craig J.; Panek, Mary G.

    1985-01-01

    Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

  1. The effect of valinomycin in fibroblasts from patients with fatty acid oxidation disorders

    SciTech Connect

    Ndukwe Erlingsson, Uzochi Chimdinma; Iacobazzi, Francesco; Liu, Aiping; Ardon, Orly; Pasquali, Marzia; Longo, Nicola

    2013-08-09

    Highlights: •Valinomycin can cause mitochondrial stress and stimulate fatty acid oxidation. •Cells with VLCAD deficiency fail to increase fatty acid oxidation in response to valinomycin. •Response to valinomycin can help in the diagnosis of VLCAD deficiency. -- Abstract: Disorders of the carnitine cycle and of the beta oxidation spiral impair the ability to obtain energy from fats at time of fasting and stress. This can result in hypoketotic hypoglycemia, cardiomyopathy, cardiac arrhythmia and other chronic medical problems. The in vitro study of fibroblasts from patients with these conditions is impaired by their limited oxidative capacity. Here we evaluate the capacity of valinomycin, a potassium ionophore that increases mitochondrial respiration, to increase the oxidation of fatty acids in cells from patients with inherited fatty acid oxidation defects. The addition of valinomycin to fibroblasts decreased the accumulation of the lipophilic cation tetraphenylphosphonium (TPP{sup +}) at low concentrations due to the dissipation of the mitochondrial membrane potential. At higher doses, valinomycin increased TPP{sup +} accumulation due to the increased potassium permeability of the plasma membrane and subsequent cellular hyperpolarization. The incubation of normal fibroblasts with valinomycin increased [{sup 14}C]-palmitate oxidation (measured as [{sup 14}C]O{sub 2} release) in a dose-dependent manner. By contrast, valinomycin failed to increase palmitate oxidation in fibroblasts from patients with very long chain acyl CoA dehydrogenase (VLCAD) deficiency. This was not observed in fibroblasts from patients heterozygous for this condition. These results indicate that valinomycin can increase fatty acid oxidation in normal fibroblasts and could be useful to differentiate heterozygotes from patients affected with VLCAD deficiency.

  2. Potential Impact of Microbial Activity on the Oxidant Capacity and the Organic Carbon Budget in Clouds (Invited)

    NASA Astrophysics Data System (ADS)

    Delort, A.

    2013-12-01

    Within cloud water, microorganisms are metabolically active; so they are suspected to contribute to atmospheric chemistry. This paper is focused on the interactions between microorganisms and Reactive Oxygenated Species present in cloud water since these chemical compounds are driving the oxidant capacity of the cloud system. For this, real cloud waters with contrasting features (marine, continental, urban) were sampled at the puy de Dôme mountain (France). They exhibit high microbial biodiversity and complex chemical composition. These media were incubated in the dark and subjected to UV-light radiation in specifically designed photo-bio-reactors. The concentrations of hydrogen peroxide (H2O2), organic compounds and the ATP/ADP ratio were monitored during the incubation period. Microorganisms remained metabolically active in the presence of hydroxyl radicals photo-produced from H2O2. This oxidant and major carbon compounds (formaldehyde and carboxylic acids) were biodegraded by the endogenous microflora. This work suggests that microorganisms could play a double role in atmospheric chemistry: first, they could directly metabolize organic carbon species; second they could reduce the available source of radicals due to their oxidative metabolism. Consequently, molecules such as H2O2 would be no longer available for photochemical or other chemical reactions, decreasing the cloud oxidant capacity.

  3. OXIDATIVE DEGRADATION OF ORGANIC ACIDS CONJUGATED WITH SULFITE OXIDATION IN FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The report gives results of a study of organic acid degradation conjugated with sulfite oxidation under flue gas desulfurization (FGD) conditions. The oxidative degradation constant, k12, is defined as the ratio of organic acid degradation rate and sulfite oxidation rate times th...

  4. High-capacity push-pickling lines and acid recovery systems

    SciTech Connect

    Braun, E.; Groessl, C. )

    1993-07-01

    High-capacity, 1.2 million ton/year, pushing-pickling lines capable of processing strip up to 76 in. wide in gages between 0.060 and 0.500 in. are a viable alternative in replacing older continuous pickling lines: space requirements are less (up to 40%) and capital costs lower (up to 60%). Installation of an acid regeneration plant provides major reductions in acid purchases as well as minimizing waste acid and rinse water disposal costs.

  5. Erythrocyte Sialic Acid Content during Aging in Humans: Correlation with Markers of Oxidative Stress

    PubMed Central

    Mehdi, Mohammad Murtaza; Singh, Prabhakar; Rizvi, Syed Ibrahim

    2012-01-01

    Sialic acids are substituted neuraminic acid derivatives which are typically found at the outermost end of glycan chains on the membrane in all cell types. The role of erythrocyte membrane sialic acids during aging has been established however the relationship between sialic acid and oxidative stress is not fully understood. The present work was undertaken to analyze the relationship between erythrocyte membrane sialic acid with its plasma level, membrane and plasma lipid hydroperoxide levels and plasma total antioxidant capacity. Results show that sialic acid content decreases significantly (P < 0.001) in RBC membrane (r = −0.901) and increases in plasma (r = 0.860) as a function of age in humans. Lipid peroxidation measured in the form of hydroperoxides increases significantly (P < 0.001) in plasma (r = 0.830) and RBC membranes (r = 0.875) with age in humans. The Trolox Equivalent Total Antioxidant Capacity (TETAC) of plasma was found to be significantly decreased (P < 0.001, r = −0.844). We observe significant correlations between decrease of erythrocyte membrane sialic acid and plasma lipid hydroperoxide and TETAC. Based on the observed correlations, we hypothesize that increase in oxidative stress during aging may influence the sialic acid decomposition from membrane thereby altering the membrane configuration affecting many enzymatic and transporter activities. Considering the importance of plasma sialic acid as a diagnostic parameter, it is important to establish age-dependent reference. PMID:22377734

  6. Salivary and Urinary Total Antioxidant Capacity as Biomarkers of Oxidative Stress in Humans

    PubMed Central

    Peluso, Ilaria; Raguzzini, Anna

    2016-01-01

    Total Antioxidant Capacity (TAC) is a biomarker often used in order to investigate oxidative stress in many pathological conditions. Saliva and urine can be collected noninvasively and represent attractive diagnostic fluids for detecting biomarkers of various pathological conditions. The reviewed case-control and intervention studies that measured salivary or urinary TAC revealed that diseases, antioxidant foods, or supplements and age, gender, and lifestyle factors influenced salivary or urinary TAC. Salivary and urinary TAC were particularly affected by oral or renal status, respectively, as well as by infection; therefore these factors must be taken into account in both case-control and intervention studies. Furthermore, some considerations on sample collection and normalization strategies could be made. In particular, unstimulated saliva could be the better approach to measure salivary TAC, whereas 24 h or spontaneous urine collection should be chosen on the basis of the study outcome and of the creatinine clearance. Finally, the uric acid-independent TAC could be the better approach to evaluate red-ox status of body, in particular after nutritional interventions and in diseases associated with hyperuricaemia. PMID:26966611

  7. Salivary and Urinary Total Antioxidant Capacity as Biomarkers of Oxidative Stress in Humans.

    PubMed

    Peluso, Ilaria; Raguzzini, Anna

    2016-01-01

    Total Antioxidant Capacity (TAC) is a biomarker often used in order to investigate oxidative stress in many pathological conditions. Saliva and urine can be collected noninvasively and represent attractive diagnostic fluids for detecting biomarkers of various pathological conditions. The reviewed case-control and intervention studies that measured salivary or urinary TAC revealed that diseases, antioxidant foods, or supplements and age, gender, and lifestyle factors influenced salivary or urinary TAC. Salivary and urinary TAC were particularly affected by oral or renal status, respectively, as well as by infection; therefore these factors must be taken into account in both case-control and intervention studies. Furthermore, some considerations on sample collection and normalization strategies could be made. In particular, unstimulated saliva could be the better approach to measure salivary TAC, whereas 24 h or spontaneous urine collection should be chosen on the basis of the study outcome and of the creatinine clearance. Finally, the uric acid-independent TAC could be the better approach to evaluate red-ox status of body, in particular after nutritional interventions and in diseases associated with hyperuricaemia. PMID:26966611

  8. Acid-base properties of titanium-antimony oxides catalysts

    SciTech Connect

    Zenkovets, G.A.; Paukshtis, E.A.; Tarasova, D.V.; Yurchenko, E.N.

    1982-06-01

    The acid-base properties of titanium-antimony oxide catalysts were studied by the methods of back titration and ir spectroscopy. The interrelationship between the acid-base and catalytic properties in the oxidative ammonolysis of propylene was discussed. 3 figures, 1 table.

  9. Assessing the Oxidative Capacity of the Atmosphere: MCMA-2003 as a Case Study

    NASA Astrophysics Data System (ADS)

    Sheehy, P. M.; Volkamer, R. M.; Velasco, E.; Alexander, M.; Jobson, T.; Lamb, B.; Molina, L. T.

    2006-12-01

    The current understanding of oxidative capacity is assessed in the polluted atmosphere, using the Mexico City Metropolitan Area (MCMA) as a case study. Measurements from the MCMA-2003 field campaign are used to constrain a photochemical box model in order to study the impact of primary HOx} radical production and ROx} radical cycling on photochemical ozone and the oxidation of VOCs that is relevant for secondary organic aerosol (SOA) formation. Time-resolved HOx} (OH and HO2) radical fluxes were experimentally quantified from the photolysis of nitrous acid (HONO), formaldehyde (HCHO), ozone (O3), acetaldehyde (CCHO), glyoxal (CHOCHO) and the reaction of alkenes with O3. The Master Chemical Mechanism (MCMv3.1), constrained for these primary HOx} radical fluxes and radical sinks (103 VOC, NO, NO2, CO, and SO2), is used to calculate primary HOx} radical fluxes from other closed shell molecules, i.e. that form as VOC oxidation products. HCHO is found to be the most important source, dominating the overall HOx} radical flux shortly after sunrise. HOx} radical production from HCHO is matched only by O3 photolysis during "high O3" days (and HONO in the early morning); photolysis of secondary products is estimated to contribute some 30% to primary HOx} radical fluxes at noontime. MCMv3.1 is used to identify the VOC precursors of photochemical HCHO. Noontime concentrations of HONO reached 120 ppt on some days, indicating a substantial source of daytime HONO is operative in Mexico City. HONO formation is separated into dark-, daytime- and photo-stationary steady state (PSS) sources. MCMv3.1 is also used to predict OH, HO2, RO2, and RO concentrations (in sum termed ROx}). Measured and modeled concentrations are compared for the following case studies: HOx}-unconstrained, OH-constrained, HO2-constrained, HOx}-constrained. For the HOx}-unconstrained case, a significant under-prediction of OH and HO2 radicals is observed in the early morning. This "missing reactivity" is highest

  10. The capacity of biochar made from common reeds to neutralise pH and remove dissolved metals in acid drainage.

    PubMed

    Mosley, Luke M; Willson, Philip; Hamilton, Benjamin; Butler, Greg; Seaman, Russell

    2015-10-01

    We tested the capacity of biochar (made at 450 °C from a common reed species) to neutralise pH and remove metals in two acid drainage waters (pH 2.6 and 4.6) using column leaching and batch mixing experiments. In the column experiments, the acid drainage water was neutralised upon passage through the biochar with substantial increases (4-5 pH units) in the leachate pH. In the batch experiments, the leachate pH remained above 6.5 when the drainage:biochar ratio was less than approximately 700:1 (L acid drainage:kg biochar) and 20:1 for the pH 4.6 and pH 2.6 drainage waters, respectively. Dissolved metal concentrations were reduced by 89-98 % (Fe ≈ Al > Ni ≈ Zn > Mn) in the leachate from the biochar. A key mechanism of pH neutralisation appears to be solid carbonate dissolution as calcite (CaCO3) was identified (via X-ray diffraction) in the biochar prior to contact with acid drainage, and dissolved alkalinity and Ca was observed in the leachate. Proton and metal removal by cation exchange, direct binding to oxygen-containing functional groups, and metal oxide precipitation also appears important. Further evaluation of the treatment capacity of other biochars and field trials are warranted. PMID:26004563

  11. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues

    SciTech Connect

    Reinecke, D. )

    1989-04-01

    Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O{sub 2}, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with {sup 14}C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA.

  12. Reduced Skeletal Muscle Oxidative Capacity and Elevated Ceramide but not Diacylglycerol Content in Severe Obesity

    PubMed Central

    Coen, P.M.; Hames, K.C.; Leachman, E.M.; DeLany, J.P.; Ritov, V.B.; Menshikova, E.V.; Dubé, J.J.; Stefanovic-Racic, M.; Toledo, F.G.S.; Goodpaster, B.H.

    2014-01-01

    Objective The link between a reduced capacity for skeletal muscle mitochondrial fatty acid oxidation (FAO) and lipotoxicity in human insulin resistance has been the subject of intense debate. The objective of this study was to investigate whether reduced FAO is associated with elevated acyl CoA, ceramide, and diacylglycerol (DAG) in severely obese insulin resistant subjects. Design and Methods Muscle biopsies were conducted in lean (L, 22.6 ± 0.5 kg/m2, n = 8), Class I (CI, 32.1 ± 0.4 kg/m2, n = 7) and Class II&III obese (CII&III, 45.6 ± 1.1 kg/m2, n = 15) women for acyl CoA, sphingolipid and DAG profiling. Intramyocellular triglyceride (IMTG) content was determined by histology. FAO was assessed by incubating muscle homogenates with [1–14C]palmitate and measuring 14CO2 production. Cardiolipin content was quantified as an index of mitochondrial content. Lipid metabolism proteins, DGAT1, PLIN5, and PNPLA2 were quantified in biopsy samples by western blot. Results CII&III were more insulin resistant (HOMA-IR: 4.5 ± 0.5 vs. 1.1 ± 0.1, P < 0.001), and had lower FAO (~58%, P = 0.007) and cardiolipin content (~31%, P = 0.013) compared to L. IMTG was elevated in CI (P = 0.04) and CII&III (P = 0.04) compared to L. Sphingolipid content was higher in CII&III compared to L (13.6 ± 1.1 vs. 10.3 ± 0.5 pmol/mg, P = 0.031) whereas DAG content was not different among groups. DGAT1 was elevated in CII&III, and PLIN5 was elevated in CI compared to L. Conclusions Severe obesity is associated with reduced muscle oxidative capacity and occurs concomitantly with elevated IMTG, ceramide and insulin resistance. PMID:23512750

  13. Spatial variability of soil gas concentration and methane oxidation capacity in landfill covers.

    PubMed

    Röwer, Inga Ute; Geck, Christoph; Gebert, Julia; Pfeiffer, Eva-Maria

    2011-05-01

    In order to devise design criteria for biocovers intended to enhance the microbial oxidation of landfill methane it is critical to understand the factors influencing gas migration and methane oxidation in landfill cover soils. On an old municipal solid waste landfill in north-western Germany soil gas concentrations (10, 40, 90 cm depth), topsoil methane oxidation capacity and soil properties were surveyed at 40 locations along a 16 m grid. As soil properties determine gas flow patterns it was hypothesized that the variability in soil gas composition and the subsequent methanotrophic activity would correspond to the variability of soil properties. Methanotrophic activity was found to be subject to high spatial variability, with values ranging between 0.17 and 9.80 g CH(4)m(-2)h(-1)(.) Considering the current gas production rate of 0.03 g CH(4)m(-2)h(-1), the oxidation capacity at all sampled locations clearly exceeded the flux to the cover, and can be regarded as an effective instrument for mitigating methane fluxes. The methane concentration in the cover showed a high spatial heterogeneity with values between 0.01 and 0.32 vol.% (10 cm depth), 22.52 vol.% (40 cm), and 36.85 vol.% (90 cm). The exposure to methane raised the oxidation capacity, suggested by a statistical correlation to an increase in methane concentration at 90 cm depth. Methane oxidation capacity was further affected by the methanotroph bacteria pH optimum and nutrient availability, and increased with decreasing pH towards neutrality, and increased with soluble ion concentration). Soil methane and carbon dioxide concentration increased with lower flow resistance of the cover, as represented by the soil properties of a reduced bulk density, increase in air capacity and in relative ground level. PMID:20943363

  14. Carnitine transport and fatty acid oxidation.

    PubMed

    Longo, Nicola; Frigeni, Marta; Pasquali, Marzia

    2016-10-01

    Carnitine is essential for the transfer of long-chain fatty acids across the inner mitochondrial membrane for subsequent β-oxidation. It can be synthesized by the body or assumed with the diet from meat and dairy products. Defects in carnitine biosynthesis do not routinely result in low plasma carnitine levels. Carnitine is accumulated by the cells and retained by kidneys using OCTN2, a high affinity organic cation transporter specific for carnitine. Defects in the OCTN2 carnitine transporter results in autosomal recessive primary carnitine deficiency characterized by decreased intracellular carnitine accumulation, increased losses of carnitine in the urine, and low serum carnitine levels. Patients can present early in life with hypoketotic hypoglycemia and hepatic encephalopathy, or later in life with skeletal and cardiac myopathy or sudden death from cardiac arrhythmia, usually triggered by fasting or catabolic state. This disease responds to oral carnitine that, in pharmacological doses, enters cells using the amino acid transporter B(0,+). Primary carnitine deficiency can be suspected from the clinical presentation or identified by low levels of free carnitine (C0) in the newborn screening. Some adult patients have been diagnosed following the birth of an unaffected child with very low carnitine levels in the newborn screening. The diagnosis is confirmed by measuring low carnitine uptake in the patients' fibroblasts or by DNA sequencing of the SLC22A5 gene encoding the OCTN2 carnitine transporter. Some mutations are specific for certain ethnic backgrounds, but the majority are private and identified only in individual families. Although the genotype usually does not correlate with metabolic or cardiac involvement in primary carnitine deficiency, patients presenting as adults tend to have at least one missense mutation retaining residual activity. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler

  15. A new equation for the limiting capacity of the lead/acid cell

    NASA Astrophysics Data System (ADS)

    Compagnone, N. F.

    As an alternative to the empirical Peukert equation, whose validity is restricted to intermediate discharge rates, a new equation for the limiting capacity of the lead/acid cell is proposed, formally derived from an approximate closed form solution of a two finite compartment diffusion problem. The four parameters of the equation are evaluated through a non-linear least-squares method. The resulting capacity curve fits the typically undulating experimental data closely throughout their range.

  16. Changes in oxidative properties of Kalanchoe blossfeldiana leaf mitochondria during development of Crassulacean acid metabolism.

    PubMed

    Rustin, P; Queiroz-Claret, C

    1985-06-01

    Kalanchoe blossfeldiana plants grown under long days (16 h light) exhibit a C3-type photosynthetic metabolism. Switching to short days (9 h light) leads to a gradual development of Crassulacean acid metabolism (CAM). Under the latter conditions, dark CO2 fixation produces large amounts of malate. During the first hours of the day, malate is rapidly decarboxylated into pyruvate through the action of a cytosolic NADP(+)-or a mitochondrial NAD(+)-dependent malic enzyme. Mitochondria were isolated from leaves of plants grown under long days or after treatment by an increasing number of short days. Tricarboxylic acid cycle intermediates as well as exogenous NADH and NADPH were readily oxidized by mitochondria isolated from the two types of plants. Glycine, known to be oxidized by C3-plant mitochondria, was still oxidized after CAM establishment. The experiments showed a marked parallelism in the increase of CAM level and the increase in substrate-oxidation capacity of the isolated mitochondria, particularly the capacity to oxidize malate in the presence of cyanide. These simultaneous variations in CAM level and in mitochondrial properties indicate that the mitochondrial NAD(+)-malic enzyme could account at least for a part of the oxidation of malate. The studies of whole-leaf respiration establish that mitochondria are implicated in malate degradation in vivo. Moreover, an increase in cyanide resistance of the leaf respiration has been observed during the first daylight hours, when malate was oxidized to pyruvate by cytosolic and mitochondrial malic enzymes. PMID:24249613

  17. Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials.

    PubMed

    Rachor, Ingke; Gebert, Julia; Gröngröft, Alexander; Pfeiffer, Eva-Maria

    2011-05-01

    The microbial oxidation of methane in engineered cover soils is considered a potent option for the mitigation of emissions from old landfills or sites containing wastes of low methane generation rates. A laboratory column study was conducted in order to derive design criteria that enable construction of an effective methane oxidising cover from the range of soils that are available to the landfill operator. Therefore, the methane oxidation capacity of different soils was assessed under simulated landfill conditions. Five sandy potential landfill top cover materials with varying contents of silt and clay were investigated with respect to methane oxidation and corresponding soil gas composition over a period of four months. The soils were compacted to 95% of their specific proctor density, resulting in bulk densities of 1.4-1.7 g cm(-3), reflecting considerably unfavourable conditions for methane oxidation due to reduced air-filled porosity. The soil water content was adjusted to field capacity, resulting in water contents ranging from 16.2 to 48.5 vol.%. The investigated inlet fluxes ranged from 25 to about 100g CH(4)m(-2)d(-1), covering the methane load proposed to allow for complete oxidation in landfill covers under Western European climate conditions and hence being suggested as a criterion for release from aftercare. The vertical distribution of gas concentrations, methane flux balances as well as stable carbon isotope studies allowed for clear process identifications. Higher inlet fluxes led to a reduction of the aerated zone, an increase in the absolute methane oxidation rate and a decline of the relative proportion of oxidized methane. For each material, a specific maximum oxidation rate was determined, which varied between 20 and 95 g CH(4)m(-2)d(-1) and which was positively correlated to the air-filled porosity of the soil. Methane oxidation efficiencies and gas profile data imply a strong link between oxidation capacity and diffusive ingress of

  18. Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials

    SciTech Connect

    Rachor, Ingke; Gebert, Julia; Groengroeft, Alexander; Pfeiffer, Eva-Maria

    2011-05-15

    The microbial oxidation of methane in engineered cover soils is considered a potent option for the mitigation of emissions from old landfills or sites containing wastes of low methane generation rates. A laboratory column study was conducted in order to derive design criteria that enable construction of an effective methane oxidising cover from the range of soils that are available to the landfill operator. Therefore, the methane oxidation capacity of different soils was assessed under simulated landfill conditions. Five sandy potential landfill top cover materials with varying contents of silt and clay were investigated with respect to methane oxidation and corresponding soil gas composition over a period of four months. The soils were compacted to 95% of their specific proctor density, resulting in bulk densities of 1.4-1.7 g cm{sup -3}, reflecting considerably unfavourable conditions for methane oxidation due to reduced air-filled porosity. The soil water content was adjusted to field capacity, resulting in water contents ranging from 16.2 to 48.5 vol.%. The investigated inlet fluxes ranged from 25 to about 100 g CH{sub 4} m{sup -2} d{sup -1}, covering the methane load proposed to allow for complete oxidation in landfill covers under Western European climate conditions and hence being suggested as a criterion for release from aftercare. The vertical distribution of gas concentrations, methane flux balances as well as stable carbon isotope studies allowed for clear process identifications. Higher inlet fluxes led to a reduction of the aerated zone, an increase in the absolute methane oxidation rate and a decline of the relative proportion of oxidized methane. For each material, a specific maximum oxidation rate was determined, which varied between 20 and 95 g CH{sub 4} m{sup -2} d{sup -1} and which was positively correlated to the air-filled porosity of the soil. Methane oxidation efficiencies and gas profile data imply a strong link between oxidation capacity

  19. Estrogen-related receptor gamma is a key regulator of muscle mitochondrial activity and oxidative capacity.

    PubMed

    Rangwala, Shamina M; Wang, Xiaomei; Calvo, Jennifer A; Lindsley, Loren; Zhang, Yunyu; Deyneko, Galina; Beaulieu, Valerie; Gao, Jiaping; Turner, Gordon; Markovits, Judit

    2010-07-16

    Estrogen-related receptor gamma (ERRgamma) regulates the perinatal switch to oxidative metabolism in the myocardium. We wanted to understand the significance of induction of ERRgamma expression in skeletal muscle by exercise. Muscle-specific VP16ERRgamma transgenic mice demonstrated an increase in exercise capacity, mitochondrial enzyme activity, and enlarged mitochondria despite lower muscle weights. Furthermore, peak oxidative capacity was higher in the transgenics as compared with control littermates. In contrast, mice lacking one copy of ERRgamma exhibited decreased exercise capacity and muscle mitochondrial function. Interestingly, we observed that increased ERRgamma in muscle generates a gene expression profile that closely overlays that of red oxidative fiber-type muscle. We further demonstrated that a small molecule agonist of ERRbeta/gamma can increase mitochondrial function in mouse myotubes. Our data indicate that ERRgamma plays an important role in causing a shift toward slow twitch muscle type and, concomitantly, a greater capacity for endurance exercise. Thus, the activation of this nuclear receptor provides a potential node for therapeutic intervention for diseases such as obesity, which is associated with reduced oxidative metabolism and a lower type I fiber content in skeletal muscle. PMID:20418374

  20. Estrogen-related Receptor γ Is a Key Regulator of Muscle Mitochondrial Activity and Oxidative Capacity

    PubMed Central

    Rangwala, Shamina M.; Wang, Xiaomei; Calvo, Jennifer A.; Lindsley, Loren; Zhang, Yunyu; Deyneko, Galina; Beaulieu, Valerie; Gao, Jiaping; Turner, Gordon; Markovits, Judit

    2010-01-01

    Estrogen-related receptor γ (ERRγ) regulates the perinatal switch to oxidative metabolism in the myocardium. We wanted to understand the significance of induction of ERRγ expression in skeletal muscle by exercise. Muscle-specific VP16ERRγ transgenic mice demonstrated an increase in exercise capacity, mitochondrial enzyme activity, and enlarged mitochondria despite lower muscle weights. Furthermore, peak oxidative capacity was higher in the transgenics as compared with control littermates. In contrast, mice lacking one copy of ERRγ exhibited decreased exercise capacity and muscle mitochondrial function. Interestingly, we observed that increased ERRγ in muscle generates a gene expression profile that closely overlays that of red oxidative fiber-type muscle. We further demonstrated that a small molecule agonist of ERRβ/γ can increase mitochondrial function in mouse myotubes. Our data indicate that ERRγ plays an important role in causing a shift toward slow twitch muscle type and, concomitantly, a greater capacity for endurance exercise. Thus, the activation of this nuclear receptor provides a potential node for therapeutic intervention for diseases such as obesity, which is associated with reduced oxidative metabolism and a lower type I fiber content in skeletal muscle. PMID:20418374

  1. Ligand-enhanced electrokinetic remediation of metal-contaminated marine sediments with high acid buffering capacity.

    PubMed

    Masi, Matteo; Iannelli, Renato; Losito, Gabriella

    2016-06-01

    The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments with high acid buffering capacity was investigated. Laboratory-scale electrokinetic remediation experiments were carried out by applying two different voltage gradients to the sediment (0.5 and 0.8 V/cm) while circulating water or two different chelating agents at the electrode compartments. Tap water, 0.1 M citric acid and 0.1 M ethylenediaminetetraacetic acid (EDTA) solutions were used respectively. The investigated metals were Zn, Pb, V, Ni and Cu. In the unenhanced experiment, the acid front could not propagate due to the high acid buffering capacity of the sediments; the production of OH(-) ions at the cathode resulted in a high-pH environment causing the precipitation of CaCO3 and metal hydroxides. The use of citric acid prevented the formation of precipitates, but solubilisation and mobilisation of metal species were not sufficiently achieved. Metal removal was relevant when EDTA was used as the conditioning agent, and the electric potential was raised up to 0.8 V/cm. EDTA led to the formation of negatively charged complexes with metals which migrated towards the anode compartment by electromigration. This result shows that metal removal from sediments with high acid buffering capacity may be achieved by enhancing the electrokinetic process by EDTA addition when the acidification of the medium is not economically and/or environmentally sustainable. PMID:26490900

  2. Effects of acute creatine supplementation on iron homeostasis and uric acid-based antioxidant capacity of plasma after wingate test

    PubMed Central

    2012-01-01

    Background Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 ± 5.8 years old) immediately before and 5 and 60 min after the exhaustive Wingate test. Results Maximum anaerobic power was improved by acute creatine supplementation (10.5 %), but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP), leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. Conclusions Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent) and inherent antioxidant activity of creatine. PMID:22691230

  3. Perm1 enhances mitochondrial biogenesis, oxidative capacity, and fatigue resistance in adult skeletal muscle.

    PubMed

    Cho, Yoshitake; Hazen, Bethany C; Gandra, Paulo G; Ward, Samuel R; Schenk, Simon; Russell, Aaron P; Kralli, Anastasia

    2016-02-01

    Skeletal muscle mitochondrial content and oxidative capacity are important determinants of muscle function and whole-body health. Mitochondrial content and function are enhanced by endurance exercise and impaired in states or diseases where muscle function is compromised, such as myopathies, muscular dystrophies, neuromuscular diseases, and age-related muscle atrophy. Hence, elucidating the mechanisms that control muscle mitochondrial content and oxidative function can provide new insights into states and diseases that affect muscle health. In past studies, we identified Perm1 (PPARGC1- and ESRR-induced regulator, muscle 1) as a gene induced by endurance exercise in skeletal muscle, and regulating mitochondrial oxidative function in cultured myotubes. The capacity of Perm1 to regulate muscle mitochondrial content and function in vivo is not yet known. In this study, we use adeno-associated viral (AAV) vectors to increase Perm1 expression in skeletal muscles of 4-wk-old mice. Compared to control vector, AAV1-Perm1 leads to significant increases in mitochondrial content and oxidative capacity (by 40-80%). Moreover, AAV1-Perm1-transduced muscles show increased capillary density and resistance to fatigue (by 33 and 31%, respectively), without prominent changes in fiber-type composition. These findings suggest that Perm1 selectively regulates mitochondrial biogenesis and oxidative function, and implicate Perm1 in muscle adaptations that also occur in response to endurance exercise. PMID:26481306

  4. Influence of phosphate ions on buffer capacity of soil humic acids

    NASA Astrophysics Data System (ADS)

    Boguta, P.; Sokołowska, Z.

    2012-02-01

    The object of this study was to determine change of natural buffer capacity of humic acids by strong buffering agents, which were phosphate ions. Studies were carried out on the humic acids extracted from peat soils. Additional information was obtained by determination of water holding capacity, density, ash and pH for peats and optical parameter Q4/6 for humic acids. Humic acid suspensions exhibited the highest buffer properties at low pH and reached maximum at pH ~ 4. Phosphates possessed buffer properties in the pH range from 4.5 to 8.0. The maximum of buffering was at pH~6.8 and increased proportionally with an increase in the concentration of phosphate ions. The study indicated that the presence of phosphate ions may strongly change natural buffer capacity of humic acids by shifting buffering maximum toward higher pH values. Significant correlations were found for the degree of the secondary transformation with both the buffer capacity and the titrant volume used during titration.

  5. Defective (U-14 C) palmitic acid oxidation in Duchenne muscular dystrophy

    SciTech Connect

    Carroll, J.E.; Norris, B.J.; Brooke, M.H.

    1985-01-01

    Compared with normal skeletal muscle, muscle from patients with Duchenne dystrophy had decreased (U-14 C) palmitic acid oxidation. (1-14 C) palmitic acid oxidation was normal. These results may indicate a defect in intramitochondrial fatty acid oxidation.

  6. Total oxidant scavenging capacities of common European fruit and vegetable juices.

    PubMed

    Lichtenthäler, Ramona; Marx, Friedhelm

    2005-01-12

    The total oxidant scavenging capacity (TOSC) assay in a modified and automated version was applied for a comparative and detailed survey of the antioxidant capacities of 14 common European fruit and vegetable juices (ACE, apple, beetroot, blueberry, carrot, elderberry, lemon, lingonberry, multivitamin, orange, pink grapefruit, sauerkraut, and tomato juices as well as sour cherry nectar). The juices were ranked according to their scavenging capacity against the three reactive oxygen species (ROS) peroxyl and hydroxyl radicals and peroxynitrite. These ROS are of physiological and technological relevance and cover a broad range of reactivity. Nonlinear correlations between concentrations of all studied samples and antioxidant capacity were taken into account for the assessment of the results. Due to the more complex assay design, results are only partially in accordance with those of the literature. Because of its outstanding TOSC values against two of the three ROS, lingonberry juice deserves special attention. PMID:15631516

  7. Stream chemistry in the eastern United States. 2. Current sources of acidity in acidic and low acid-neutralizing-capacity streams

    SciTech Connect

    Herlihy, A.T.; Kaufmann, P.R.; Mitch, M.E.

    1991-01-01

    The authors examined anion composition in National Stream Survey (NSS) data in order to evaluate the most probable sources of current acidity in acidic and low acid neutralizing capacity (ANC) streams in the eastern United States. Acidic streams that had almost no organic influence (less than 10% of total anions) and sulfate and nitrate concentrations indicative of evaporative concentration of atmospheric deposition were classified as acidic due to acidic deposition. These acidic streams were located in small forested watersheds in the Mid-Atlantic Highlands (an estimated 1950 km of stream length) and in the Mid-Atlantic Coastal Plain (1250 km). Acidic streams affected primarily by acidic deposition but also influenced by naturally occurring organic anions accounted for another 1180 km of acidic stream length and were located in the New Jersey Pine Barrens, plateau tops in the Mid-Atlantic and Southeast Highlands, and the Florida Panhandle. The total length of streams acidic due to acid mine drainage in the NSS (4590 km) was about the same as the total length of acidic streams likely affected by acidic deposition (4380 km). Acidic streams whose acid anion composition was dominated by organics were located in Florida and the Mid-Atlantic Coastal Plain. In Florida, most of the acidic streams were organic dominated, whereas about half of the streams in the Mid-Atlantic Coastal Plain were organic dominated. Organic-dominated acidic streams were not observed in the Mid-Atlantic and Southeast Highlands.

  8. Stream chemistry in the eastern United States, 2, Current sources of acidity in acidic and low acid-neutralizing capacity streams

    NASA Astrophysics Data System (ADS)

    Herlihy, Alan T.; Kaufmann, Philip R.; Mitch, Mark E.

    1991-04-01

    We examined anion composition in National Stream Survey (NSS) data in order to evaluate the most probable sources of current acidity in acidic and low acid-neutralizing capacity (ANC) streams in the eastern United States. Acidic streams that had almost no organic influence (less than 10% of total anions) and sulfate and nitrate concentrations indicative of evaporative concentration of atmospheric deposition were classified as acidic due to acidic deposition. These acidic streams were located in small (<30 km2) forested watersheds in the Mid-Atlantic Highlands (an estimated 1950 km of stream length) and in the Mid-Atlantic Coastal Plain (1250 km). Acidic streams affected primarily by acidic deposition but also influenced by naturally occurring organic anions accounted for another 1180 km of acidic stream length and were located in the New Jersey Pine Barrens, plateau tops in the Mid-Atlantic and Southeast Highlands, and the Florida Panhandle. The total length of streams acidic due to acid mine drainage in the NSS (4590 km) was about the same as the total length of acidic streams likely affected by acidic deposition (4380 km). Acidic streams whose acid anion composition was dominated by organics were located in Florida and the Mid-Atlantic Coastal Plain. In Florida, most of the acidic streams were organic dominated, whereas about half of the streams in the Mid-Atlantic Coastal Plain were organic dominated. Organic-dominated acidic streams were not observed in the Mid-Atlantic and Southeast Highlands.

  9. Mild Hyperbaric Oxygen Improves Decreased Oxidative Capacity of Spinal Motoneurons Innervating the Soleus Muscle of Rats with Type 2 Diabetes.

    PubMed

    Takemura, Ai; Ishihara, Akihiko

    2016-09-01

    Rats with type 2 diabetes exhibit decreased oxidative capacity, such as reduced oxidative enzyme activity, low-intensity staining for oxidative enzymes in fibers, and no high-oxidative type IIA fibers, in the skeletal muscle, especially in the soleus muscle. In contrast, there are no data available concerning the oxidative capacity of spinal motoneurons innervating skeletal muscle of rats with type 2 diabetes. This study examined the oxidative capacity of motoneurons innervating the soleus muscle of non-obese rats with type 2 diabetes. In addition, this study examined the effects of mild hyperbaric oxygen at 1.25 atmospheres absolute with 36 % oxygen for 10 weeks on the oxidative capacity of motoneurons innervating the soleus muscle because mild hyperbaric oxygen improves the decreased oxidative capacity of the soleus muscle in non-obese rats with type 2 diabetes. Spinal motoneurons innervating the soleus muscle were identified using nuclear yellow, a retrograde fluorescent neuronal tracer. Thereafter, the cell body sizes and succinate dehydrogenase activity of identified motoneurons were analyzed. Decreased succinate dehydrogenase activity of small-sized alpha motoneurons innervating the soleus muscle was observed in rats with type 2 diabetes. The decreased succinate dehydrogenase activity of these motoneurons was improved by mild hyperbaric oxygen. Therefore, we concluded that rats with type 2 diabetes have decreased oxidative capacity in motoneurons innervating the soleus muscle and this decreased oxidative capacity is improved by mild hyperbaric oxygen. PMID:27220333

  10. Peroxisomal fatty acid oxidation and inhibitors of the mitochondrial carnitine palmitoyltransferase I in isolated rat hepatocytes.

    PubMed Central

    Skorin, C; Necochea, C; Johow, V; Soto, U; Grau, A M; Bremer, J; Leighton, F

    1992-01-01

    Fatty acid oxidation was studied in the presence of inhibitors of carnitine palmitoyltransferase I (CPT I), in normal and in peroxisome-proliferated rat hepatocytes. The oxidation decreased in mitochondria, as expected, but in peroxisomes it increased. These two effects were seen, in variable proportions, with (+)-decanoylcarnitine, 2-tetradecylglycidic acid (TDGA) and etomoxir. The decrease in mitochondrial oxidation (ketogenesis) affected saturated fatty acids with 12 or more carbon atoms, whereas the increase in peroxisomal oxidation (H2O2 production) affected saturated fatty acids with 8 or more carbon atoms. The peroxisomal increase was sensitive to chlorpromazine, a peroxisomal inhibitor. To study possible mechanisms, palmitoyl-, octanoyl- and acetyl-carnitine acyltransferase activities were measured, in homogenates and in subcellular fractions from control and TDGA-treated cells. The palmitoylcarnitine acyltransferase was inhibited, as expected, but the octanoyltransferase activity also decreased. The CoA derivative of TDGA was synthesized and tentatively identified as being responsible for inhibition of the octanoylcarnitine acyltransferase. These results show that inhibitors of the mitochondrial CPT I may also inhibit the peroxisomal octanoyl transferase; they also support the hypothesis that the octanoyltransferase has the capacity to control or regulate peroxisomal fatty acid oxidation. PMID:1736904

  11. Phenolic acids and antioxidant capacity of distillers dried grains with solubles (DDGS) as compared with corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three sets of ground corn and the corresponding distillers dried grains with solubles (DDGS) were collected from three commercial plants and analyzed for individual phenolic acids by high performance liquid chromatography coupled with diode array and/or mass spectrometry and for antioxidant capacity...

  12. Reversible anionic redox chemistry in high-capacity layered-oxide electrodes.

    PubMed

    Sathiya, M; Rousse, G; Ramesha, K; Laisa, C P; Vezin, H; Sougrati, M T; Doublet, M-L; Foix, D; Gonbeau, D; Walker, W; Prakash, A S; Ben Hassine, M; Dupont, L; Tarascon, J-M

    2013-09-01

    Li-ion batteries have contributed to the commercial success of portable electronics and may soon dominate the electric transportation market provided that major scientific advances including new materials and concepts are developed. Classical positive electrodes for Li-ion technology operate mainly through an insertion-deinsertion redox process involving cationic species. However, this mechanism is insufficient to account for the high capacities exhibited by the new generation of Li-rich (Li(1+x)Ni(y)Co(z)Mn(1-x-y-z)O₂) layered oxides that present unusual Li reactivity. In an attempt to overcome both the inherent composition and the structural complexity of this class of oxides, we have designed structurally related Li₂Ru(1-y)Sn(y)O₃ materials that have a single redox cation and exhibit sustainable reversible capacities as high as 230 mA h g(-1). Moreover, they present good cycling behaviour with no signs of voltage decay and a small irreversible capacity. We also unambiguously show, on the basis of an arsenal of characterization techniques, that the reactivity of these high-capacity materials towards Li entails cumulative cationic (M(n+)→M((n+1)+)) and anionic (O(2-)→O₂(2-)) reversible redox processes, owing to the d-sp hybridization associated with a reductive coupling mechanism. Because Li₂MO₃ is a large family of compounds, this study opens the door to the exploration of a vast number of high-capacity materials. PMID:23852398

  13. Reversible anionic redox chemistry in high-capacity layered-oxide electrodes

    NASA Astrophysics Data System (ADS)

    Sathiya, M.; Rousse, G.; Ramesha, K.; Laisa, C. P.; Vezin, H.; Sougrati, M. T.; Doublet, M.-L.; Foix, D.; Gonbeau, D.; Walker, W.; Prakash, A. S.; Ben Hassine, M.; Dupont, L.; Tarascon, J.-M.

    2013-09-01

    Li-ion batteries have contributed to the commercial success of portable electronics and may soon dominate the electric transportation market provided that major scientific advances including new materials and concepts are developed. Classical positive electrodes for Li-ion technology operate mainly through an insertion-deinsertion redox process involving cationic species. However, this mechanism is insufficient to account for the high capacities exhibited by the new generation of Li-rich (Li1+xNiyCozMn(1-x-y-z)O2) layered oxides that present unusual Li reactivity. In an attempt to overcome both the inherent composition and the structural complexity of this class of oxides, we have designed structurally related Li2Ru1-ySnyO3 materials that have a single redox cation and exhibit sustainable reversible capacities as high as 230 mA h g-1. Moreover, they present good cycling behaviour with no signs of voltage decay and a small irreversible capacity. We also unambiguously show, on the basis of an arsenal of characterization techniques, that the reactivity of these high-capacity materials towards Li entails cumulative cationic (Mn+→M(n+1)+) and anionic (O2-→O22-) reversible redox processes, owing to the d-sp hybridization associated with a reductive coupling mechanism. Because Li2MO3 is a large family of compounds, this study opens the door to the exploration of a vast number of high-capacity materials.

  14. Rev-erb-α modulates skeletal muscle oxidative capacity by regulating mitochondrial biogenesis and autophagy

    PubMed Central

    Woldt, Estelle; Sebti, Yasmine; Solt, Laura A.; Duhem, Christian; Lancel, Steve; Eeckhoute, Jérôme; Hesselink, Matthijs K.C.; Paquet, Charlotte; Delhaye, Stéphane; Shin, Youseung; Kamenecka, Theodore M.; Schaart, Gert; Lefebvre, Philippe; Nevière, Rémi; Burris, Thomas P.; Schrauwen, Patrick; Staels, Bart; Duez, Hélène

    2013-01-01

    The nuclear receptor Rev-erb-α modulates hepatic lipid and glucose metabolism, adipogenesis and the inflammatory response in macrophages. We show here that Rev-erb-α is highly expressed in oxidative skeletal muscle and plays a role in mitochondrial biogenesis and oxidative function, in gain- and loss-of function studies. Rev-erb-α-deficiency in skeletal muscle leads to reduced mitochondrial content and oxidative function, resulting in compromised exercise capacity. This phenotype was recapitulated in isolated fibers and in muscle cells upon Rev-erbα knock-down, while Rev-erb-α over-expression increased the number of mitochondria with improved respiratory capacity. Rev-erb-α-deficiency resulted in deactivation of the Stk11–Ampk–Sirt1–Ppargc1-α signaling pathway, whereas autophagy was up-regulated, resulting in both impaired mitochondrial biogenesis and increased clearance. Muscle over-expression or pharmacological activation of Rev-erb-α increased respiration and exercise capacity. This study identifies Rev-erb-α as a pharmacological target which improves muscle oxidative function by modulating gene networks controlling mitochondrial number and function. PMID:23852339

  15. TWEAK promotes exercise intolerance by decreasing skeletal muscle oxidative phosphorylation capacity

    PubMed Central

    2013-01-01

    Background Proinflammatory cytokine tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and its receptor Fn14 are the major regulators of skeletal muscle mass in many catabolic conditions. However, their role in muscle metabolism remains largely unknown. In the present study, we investigated the role of TWEAK on exercise capacity and skeletal muscle mitochondrial content and oxidative metabolism. Methods We employed wild-type and TWEAK-knockout (KO) mice and primary myotube cultures and performed biochemical, bioenergetics, and morphometric assays to evaluate the effects of TWEAK on exercise tolerance and muscle mitochondrial function and angiogenesis. Results TWEAK-KO mice showed improved exercise tolerance compared to wild-type mice. Electron microscopy analysis showed that the abundance of subsarcolemmal and intermyofibrillar mitochondria is significantly increased in skeletal muscle of TWEAK-KO mice compared to wild-type mice. Furthermore, age-related loss in skeletal muscle oxidative capacity was rescued in TWEAK-KO mice. Expression of a key transcriptional regulator peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and several other molecules involved in oxidative metabolism were significantly higher in skeletal muscle of TWEAK-KO mice. Moreover, treatment of primary myotubes with soluble TWEAK inhibited the expression of PGC-1α and mitochondrial genes and decreased mitochondrial respiratory capacity. Deletion of TWEAK also improved angiogenesis and transcript levels of vascular endothelial growth factor in skeletal muscle of mice. Conclusions These results demonstrate that TWEAK decreases mitochondrial content and oxidative phosphorylation and inhibits angiogenesis in skeletal muscle. Neutralization of TWEAK is a potential approach for improving exercise capacity and oxidative metabolism in skeletal muscle. PMID:23835416

  16. Total oxidant status, total antioxidant capacity and ischemia modified albumin levels in children with celiac disease.

    PubMed

    Sayar, Ersin; Özdem, Sebahat; Uzun, Gülbahar; İşlek, Ali; Yılmaz, Aygen; Artan, Reha

    2015-01-01

    In our study, we aimed to investigate ischemia modified albumin (IMA) as an oxidative stress marker, as well as other oxidant and antioxidant markers that have not been evaluated in children with celiac disease. A total of 37 pediatric patients who were diagnosed with celiac disease (CD) and 29 healthy children were enrolled in this prospective study. We evaluated the IMA, total oxidant status, total antioxidant capacity, sulfhydryl, and advanced oxidation protein products in all of the subjects. We also compared the levels at the time of the diagnosis, and following a gluten-free diet (GFD) in the children with CD. While the IMA and the other oxidant marker levels were significantly higher in the patient group compared to the control group, the antioxidant marker levels were found to be significantly lower in the patient group, compared to the control group. We also determined that the tissue transglutaminase IgA showed a highly positive correlation, and that the IMA showed a moderately positive correlation with the Marsh-Oberhuber histopathological stage. Additionally, the IMA and other oxidant marker levels were significantly lower, while the antioxidant marker levels were significantly higher after the GFD, compared to the pre-diet period. We detected that oxidative stress played a role in the pathogenesis of CD, and that this could be evaluated using oxidative stress markers, which would regress after the GFD. We also detected that IMA is a marker that shows a correlation with the histopathological stage, and may be used in the diagnosis. PMID:27411418

  17. Enhanced exercise and regenerative capacity in a mouse model that violates size constraints of oxidative muscle fibres.

    PubMed

    Omairi, Saleh; Matsakas, Antonios; Degens, Hans; Kretz, Oliver; Hansson, Kenth-Arne; Solbrå, Andreas Våvang; Bruusgaard, Jo C; Joch, Barbara; Sartori, Roberta; Giallourou, Natasa; Mitchell, Robert; Collins-Hooper, Henry; Foster, Keith; Pasternack, Arja; Ritvos, Olli; Sandri, Marco; Narkar, Vihang; Swann, Jonathan R; Huber, Tobias B; Patel, Ketan

    2016-01-01

    A central tenet of skeletal muscle biology is the existence of an inverse relationship between the oxidative fibre capacity and its size. However, robustness of this relationship is unknown. We show that superimposition of Estrogen-related receptor gamma (Errγ) on the myostatin (Mtn) mouse null background (Mtn(-/-)/Errγ(Tg/+)) results in hypertrophic muscle with a high oxidative capacity thus violating the inverse relationship between fibre size and oxidative capacity. We also examined the canonical view that oxidative muscle phenotype positively correlate with Satellite cell number, the resident stem cells of skeletal muscle. Surprisingly, hypertrophic fibres from Mtn(-/-)/Errγ(Tg/+) mouse showed satellite cell deficit which unexpectedly did not affect muscle regeneration. These observations 1) challenge the concept of a constraint between fibre size and oxidative capacity and 2) indicate the important role of the microcirculation in the regenerative capacity of a muscle even when satellite cell numbers are reduced. PMID:27494364

  18. Storage capacity and oxygen mobility in mixed oxides from transition metals promoted by cerium

    NASA Astrophysics Data System (ADS)

    Perdomo, Camilo; Pérez, Alejandro; Molina, Rafael; Moreno, Sonia

    2016-10-01

    The oxygen mobility and storage capacity of Ce-Co/Cu-MgAl or Ce-MgAl mixed oxides, obtained by hydrotalcite precursors, were evaluated using Toluene-temperature-programmed-reaction, 18O2 isotopic exchange and O2-H2 titration. The presence of oxygen vacancies-related species was evaluated by means of Electron Paramagnetic Resonance. A correlation was found between the studied properties and the catalytic activity of the oxides in total oxidation processes. It was evidenced that catalytic activity depends on two related processes: the facility with which the solid can be reduced and its ability to regenerate itself in the presence of molecular oxygen in the gas phase. These processes are enhanced by Cu-Co cooperative effect in the mixed oxides. Additionally, the incorporation of Ce in the Co-Cu catalysts improved their oxygen transport properties.

  19. Rapid Detection of Neutrophil Oxidative Burst Capacity is Predictive of Whole Blood Cytokine Responses

    PubMed Central

    Vernon, Philip J.; Schaub, Leasha J.; Dallelucca, Jurandir J.; Pusateri, Anthony E.; Sheppard, Forest R.

    2015-01-01

    Background Maladaptive immune responses, particularly cytokine and chemokine-driven, are a significant contributor to the deleterious inflammation present in many types of injury and infection. Widely available applications to rapidly assess individual inflammatory capacity could permit identification of patients at risk for exacerbated immune responses and guide therapy. Here we evaluate neutrophil oxidative burst (NOX) capacity measured by plate reader to immuno-type Rhesus Macaques as an acute strategy to rapidly detect inflammatory capacity and predict maladaptive immune responses as assayed by cytokine array. Methods Whole blood was collected from anesthetized Rhesus Macaques (n = 25) and analyzed for plasma cytokine secretion (23-plex Luminex assay) and NOX capacity. For cytokine secretion, paired samples were either unstimulated or ex-vivo lipopolysaccharide (LPS)-stimulated (100μg/mL/24h). NOX capacity was measured in dihydrorhodamine-123 loaded samples following phorbol 12-myristate 13-acetate (PMA)/ionomycin treatment. Pearson’s test was utilized to correlate NOX capacity with cytokine secretion, p<0.05 considered significant. Results LPS stimulation induced secretion of the inflammatory molecules G-CSF, IL-1β, IL-1RA, IL-6, IL-10, IL-12/23(p40), IL-18, MIP-1α, MIP-1β, and TNFα. Although values were variable, several cytokines correlated with NOX capacity, p-values≤0.0001. Specifically, IL-1β (r = 0.66), IL-6 (r = 0.74), the Th1-polarizing cytokine IL-12/23(p40) (r = 0.78), and TNFα (r = 0.76) were strongly associated with NOX. Conclusion NOX capacity correlated with Th1-polarizing cytokine secretion, indicating its ability to rapidly predict inflammatory responses. These data suggest that NOX capacity may quickly identify patients at risk for maladaptive immune responses and who may benefit from immuno-modulatory therapies. Future studies will assess the in-vivo predictive value of NOX in animal models of immune-mediated pathologies. PMID

  20. Sodium Picosulfate, Magnesium Oxide, and Anhydrous Citric Acid

    MedlinePlus

    Sodium picosulfate, magnesium oxide, and anhydrous citric acid combination powder is used to empty the colon (large intestine, bowel) before a colonoscopy (examination of the inside of the colon to check ...

  1. UNDERSTANDING REGIONAL OXIDATION CAPACITY BY COMPREHENSIVE OBSERVATIONS TO CONSTRAIN HYDROXYL RADICAL SOURCES AND SINKS DURING THE SOUTHERN OXIDANT AEROSOL STUDY (SOAS)

    EPA Science Inventory

    The proposed field measurements and data analysis will provide an important constraint to understand oxidation capacity in the Southeastern U.S. that determines SOA and photochemical ozone formation. Unexpectedly high levels of OH determining oxidation capacity have been co...

  2. Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid and sodium lauryl sulfate

    SciTech Connect

    Onysko, S.J.

    1984-07-01

    Acid mine drainage is formed by the weathering or oxidation of pyritic material exposed during coal mining. The rate of pyritic material oxidation can be greatly accelerated by certain acidophilic bacteria such as Thiobacillus ferrooxidans which catalyse the oxidation of ferrous to ferric iron. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage micro-organisms. Sodium lauryl sulphate (SLS), an anionic surfactant has proved effective in this respect. Benzoic acid, sorbic acid and SLS at low concentrations, each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of T. ferrooxidans. The rate of chemical oxidation of ferrous iron in low pH, sterile, batch reactors was not substantially affected at the tested concentrations of any of the compounds.

  3. The anodic oxidation of p-benzoquinone and maleic acid

    SciTech Connect

    Bock, C.; MacDougall, B.

    1999-08-01

    The oxidation of organics, in particular of p-benzoquinone and maleic acid, at high anodic potentials has been studied using a range of anode materials such as noble-metal-based oxides and antimony-doped tin oxides. The influence of the current density was also investigated showing that the oxidation rate of p-benzoquinone increased only slightly with increasing current density. The efficiency of the p-benzoquinone oxidation was found to depend on several properties of the anode material, not just its chemical nature. Furthermore, efficiencies for the partial oxidation of p-benzoquinone using specially prepared noble-metal-oxide-based anodes were found to be only somewhat smaller or even as high as those observed for PbO{sub 2} or antimony-doped tin oxide anodes, respectively. The anodic electrolysis of maleic acid solutions was found to decrease the activity of IrO{sub 2} for the oxidation of organic compounds. This was not observed when PbO{sup 2} was employed for the oxidation of maleic acid.

  4. Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid, and sodium lauryl sulfate

    SciTech Connect

    Onysko, S.J.; Kleinmann, R.L.P.; Erickson, P.M.

    1984-07-01

    Thiobacillus ferrooxidans promote indirect oxidation of pyrite through the catalysis of the oxidation of ferrous iron to ferric iron, which is an effective oxidant of pyrite. These bacteria also may catalyze direct oxidation of pyrite by oxygen. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous iron to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage microorganisms. In this study, benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds.

  5. A method for measuring fatty acid oxidation in C. elegans.

    PubMed

    Elle, Ida Coordt; Rødkær, Steven Vestergaard; Fredens, Julius; Færgeman, Nils Joakim

    2012-01-01

    The nematode C. elegans has during the past decade proven to be a valuable model organism to identify and examine molecular mechanisms regulating lipid storage and metabolism. While the primary approach has been to identify genes and pathways conferring alterations in lipid accumulation, only a few recent studies have recognized the central role of fatty acid degradation in cellular lipid homeostasis. In the present study, we show how complete oxidation of fatty acids can be determined in live C. elegans by examining oxidation of tritium-labeled fatty acids to tritiated H2O that can be measured by scintillation counting. Treating animals with sodium azide, an inhibitor of the electron transport chain, reduced (3)H2O production to approximately 15%, while boiling of animals prior to assay completely blocked the production of labeled water. We demonstrate that worms fed different bacterial strains exhibit different fatty acid oxidation rates. We show that starvation results in increased fatty acid oxidation, which is independent of the transcription factor NHR-49. On the contrary, fatty acid oxidation is reduced to approximately 70% in animals lacking the worm homolog of the insulin receptor, DAF-2. Hence, the present methodology can be used to delineate the role of specific genes and pathways in the regulation of β-oxidation in C. elegans. PMID:24058820

  6. Oxidation of oleic acid monolayers at air/liquid interfaces

    NASA Astrophysics Data System (ADS)

    Voss, L. F.; Bazerbashi, M. F.; Beekman, C. P.; Hadad, C. M.; Allen, H. C.

    2006-12-01

    Field studies of marine and continental aerosols find that fatty acid films form on aqueous tropospheric aerosols. Oxidation of the acyl chains is thought to be key to aerosol growth. Oxidation of oleic acid monolayers by ozone was studied to understand the fate of fat-coated aerosols from both fresh and salt water sources. Using vibrational sum frequency generation spectroscopy and reflection absorption infrared spectroscopy, we present a molecular-level investigation of fatty acid monolayers at the air-water and air- sodium chloride solution interface and explore reactions with atmospheric oxidants by these model systems. Using sum frequency generation spectroscopy coupled with a Langmuir trough, concurrent spectroscopic and thermodynamic data were collected to obtain a molecular picture of the monolayers. No substantial difference was observed between oxidation of monolayers spread on water and on 0.6 molar sodium chloride solutions. Results indicate that depending on the size of the aerosol and the extent of oxidation, the subsequent oxidation products may not remain at the surface of these films, but instead be dissolved in the aqueous sub-phase of the aerosol particle. Results also indicate that oxidation of oleic acid could produce monolayers containing species that have no oxidized acyl chains.

  7. The Nitric Acid Oxidation of Selected Alcohols and Ketones.

    ERIC Educational Resources Information Center

    Field, Kurt W.; And Others

    1985-01-01

    Shows that nitric acid can be used as a rapid, versatile, and economical oxidant for selected organic substances. The experiments (with background information, procedures, and results provided) require one three-hour laboratory period but could serve as open-ended projects since substrates not described could be oxidized. (JN)

  8. Acetic acid oxidation and hydrolysis in supercritical water

    SciTech Connect

    Meyer, J.C.; Marrone, P.A.; Tester, J.W.

    1995-09-01

    Acetic acid (CH{sub 3}COOH) hydrolysis and oxidation in supercritical water were examined from 425--600 C and 246 bar at reactor residence times of 4.4 to 9.8 s. Over the range of conditions studied, acetic acid oxidation was globally 0.72 {+-} 0.15 order in acetic acid and 0.27 {+-} 0.15 order in oxygen to a 95% confidence level, with an activation energy of 168 {+-} 21 kJ/mol, a preexponential factor of 10{sup 9.9{+-}1.7}, and an induction time of about 1.5 s at 525 C. Isothermal kinetic measurements at 550 C over the range 160 to 263 bar indicated that pressure or density did not affect the rate of acetic acid oxidation as much as was previously observed in the oxidation of hydrogen or carbon monoxide in supercritical water. Major products of acetic acid oxidation in supercritical water are carbon dioxide, carbon monoxide, methane, and hydrogen. Trace amounts of propenoic acid were occasionally detected. Hydrolysis or hydrothermolysis in the absence of oxygen resulted in approximately 35% conversion of acetic acid at 600 C, 246 bar, and 8-s reactor residence time. Regression of the limited hydrolysis runs assuming a reaction rate first-order in organic gave a global rate expression with a preexponential factor of 10{sup 4.4{+-}1.1} and an activation energy of 94 {+-} 17 kJ/mol.

  9. Ghrelin reduces hepatic mitochondrial fatty acid beta oxidation.

    PubMed

    Rigault, C; Le Borgne, F; Georges, B; Demarquoy, J

    2007-04-01

    Ghrelin is a 28-amino-acid peptide secreted during starvation by gastric cells. Ghrelin physiologically induces food intake and seems to alter lipid and glucid metabolism in several tissues such as adipose tissue and liver. Liver has a key position in lipid metabolism as it allows the metabolic orientation of fatty acids between oxidation and esterification. We investigated the effects of peripheral ghrelin administration on 2 crucial parameters of fatty acid oxidation: the levocarnitine (L-carnitine)-dependent entry of the fatty acids in the mitochondria and the mitochondrial fatty acid oxidation. Ghrelin was either given to rats prior to the hepatocyte preparation and culture or used to treat hepatocytes prepared from control animals. Direct incubation of ghrelin to raw hepatocytes did not induce any change in the studied parameters. In hepatocytes prepared from 3 nmol ghrelin-treated rats, a 44% reduction of the mitochondrial fatty acid oxidation while no alteration of the L-carnitine-related parameters were observed. These results suggested (a) that ghrelin has no direct effect on liver, and (b) that when administrated to a whole organism, ghrelin may alter the lipid metabolism and the energy balance through a marked decrease in liver fatty acid oxidation. PMID:17556859

  10. Hindlimb unloading increases oxidative stress and disrupts antioxidant capacity in skeletal muscle

    NASA Technical Reports Server (NTRS)

    Lawler, John M.; Song, Wook; Demaree, Scott R.; Bloomfield, S. A. (Principal Investigator)

    2003-01-01

    Skeletal muscle disuse with space-flight and ground-based models (e.g., hindlimb unloading) results in dramatic skeletal muscle atrophy and weakness. Pathological conditions that cause muscle wasting (i.e., heart failure, muscular dystrophy, sepsis, COPD, cancer) are characterized by elevated "oxidative stress," where antioxidant defenses are overwhelmed by oxidant production. However, the existence, cellular mechanisms, and ramifications of oxidative stress in skeletal muscle subjected to hindlimb unloading are poorly understood. Thus we examined the effects of hindlimb unloading on hindlimb muscle antioxidant enzymes (e.g., superoxide dismutase, catalase, glutathione peroxidase), nonenzymatic antioxidant scavenging capacity (ASC), total hydroperoxides, and dichlorohydrofluorescein diacetate (DCFH-DA) oxidation, a direct indicator of oxidative stress. Twelve 6 month old Sprague Dawley rats were divided into two groups: 28 d of hindlimb unloading (n = 6) and controls (n = 6). Hindlimb unloading resulted in a small decrease in Mn-superoxide dismutase activity (10.1%) in the soleus muscle, while Cu,Zn-superoxide dismutase increased 71.2%. In contrast, catalase and glutathione peroxidase, antioxidant enzymes that remove hydroperoxides, were significantly reduced in the soleus with hindlimb unloading by 54.5 and 16.1%, respectively. Hindlimb unloading also significantly reduced ASC. Hindlimb unloading increased soleus lipid hydroperoxide levels by 21.6% and hindlimb muscle DCFH-DA oxidation by 162.1%. These results indicate that hindlimb unloading results in a disruption of antioxidant status, elevation of hydroperoxides, and an increase in oxidative stress.

  11. Extracorporeal membrane oxygenation promotes long chain fatty acid oxidation in the immature swine heart in vivo

    SciTech Connect

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

    2013-09-01

    Extracorporeal membrane oxygenation (ECMO) supports infants and children with severe cardiopulmonary compromise. Nutritional support for these children includes provision of medium- and long-chain fatty acids (FAs). However, ECMO induces a stress response, which could limit the capacity for FA oxidation. Metabolic impairment could induce new or exacerbate existing myocardial dysfunction. Using a clinically relevant piglet model, we tested the hypothesis that ECMO maintains the myocardial capacity for FA oxidation and preserves myocardial energy state. Provision of 13-Carbon labeled medium-chain FA (octanoate), longchain free FAs (LCFAs), and lactate into systemic circulation showed that ECMO promoted relative increases in myocardial LCFA oxidation while inhibiting lactate oxidation. Loading of these labeled substrates at high dose into the left coronary artery demonstrated metabolic flexibility as the heart preferentially oxidized octanoate. ECMO preserved this octanoate metabolic response, but also promoted LCFA oxidation and inhibited lactate utilization. Rapid upregulation of pyruvate dehydrogenase kinase-4 (PDK4) protein appeared to participate in this metabolic shift during ECMO. ECMO also increased relative flux from lactate to alanine further supporting the role for pyruvate dehydrogenase inhibition by PDK4. High dose substrate loading during ECMO also elevated the myocardial energy state indexed by phosphocreatine to ATP ratio. ECMO promotes LCFA oxidation in immature hearts, while maintaining myocardial energy state. These data support the appropriateness of FA provision during ECMO support for the immature heart.

  12. Evidence of Preserved Oxidative Capacity and Oxygen Delivery in the Plantar Flexor Muscles With Age.

    PubMed

    Hart, Corey R; Layec, Gwenael; Trinity, Joel D; Liu, Xin; Kim, Seong-Eun; Groot, H Jonathan; Le Fur, Yann; Sorensen, Jacob R; Jeong, Eun-Kee; Richardson, Russell S

    2015-09-01

    Studies examining the effect of aging on skeletal muscle oxidative capacity have yielded equivocal results; however, these investigations may have been confounded by differences in oxygen (O(2)) delivery, physical activity, and small numbers of participants. Therefore, we evaluated skeletal muscle oxidative capacity and O(2) delivery in a relatively large group (N = 40) of young (22 ± 2 years) and old (73 ± 7 years) participants matched for physical activity. After submaximal dynamic plantar flexion exercise, phosphocreatine (PCr) resynthesis ((31)P magnetic resonance spectroscopy), muscle reoxygenation (near-infrared spectroscopy), and popliteal artery blood flow (Doppler ultrasound) were measured. The phosphocreatine recovery time constant (Tau) (young: 33 ± 16; old: 30 ± 11 seconds), maximal rate of adenosine triphosphate (ATP) synthesis (young: 25 ± 9; old: 27 ± 8 mM/min), and muscle reoxygenation rates determined by the deoxyhemoglobin/myoglobin recovery Tau (young: 48 ± 5; old: 47 ± 9 seconds) were similar between groups. Similarly, although tending to be higher in the old, there were no significant age-related differences in postexercise popliteal blood flow (area under the curve: young: 1,665 ± 227 vs old: 2,404 ± 357 mL, p = .06) and convective O(2) delivery (young: 293 ± 146 vs old: 404 ± 191 mL, p = .07). In conclusion, when physical activity and O(2) delivery are similar, oxidative capacity in the plantar flexors is not affected by aging. These findings reveal that diminished skeletal muscle oxidative capacity is not an obligatory accompaniment to the aging process. PMID:25165028

  13. The Oxidation of Hydrazine by Nitric Acid

    SciTech Connect

    Karraker, D.G.

    2001-07-02

    Hydrazine nitrate-nitric acid solutions are used in the ion exchange process for separating Pu-238 and Np-237 and have been found to dissolve plutonium metal in a manner advantageous to SRP metal recovery operations. Laboratory tests on the stability of hydrazine in nitric acid solutions were performed to obtain accurate data, and the results of these tests are reported here. These tests provide sufficient information to specify temperature control for hydrazine-nitric acid solutions in plant processes.

  14. Effect of propionic acid on fatty acid oxidation and ureagenesis.

    PubMed

    Glasgow, A M; Chase, H P

    1976-07-01

    Propionic acid significantly inhibited 14CO2 production from [1-14C] palmitate at a concentration of 10 muM in control fibroblasts and 100 muM in methylmalonic fibroblasts. This inhibition was similar to that produced by 4-pentenoic acid. Methylmalonic acid also inhibited 14CO2 production from [1-14C] palmitate, but only at a concentration of 1 mM in control cells and 5 mM in methylmalonic cells. Propionic acid (5 mM) also inhibited ureagenesis in rat liver slices when ammonia was the substrate but not with aspartate and citrulline as substrates. Propionic acid had no direct effect on either carbamyl phosphate synthetase or ornithine transcarbamylase. These findings may explain the fatty degeneration of the liver and the hyperammonemia in propionic and methylmalonic acidemia. PMID:934734

  15. Phosphorus-doped tin oxides/carbon nanofibers webs as lithium-ion battery anodes with enhanced reversible capacity

    NASA Astrophysics Data System (ADS)

    Liu, Xiaowei; Teng, Donghua; Li, Ting; Yu, Yunhua; Shao, Xiaohong; Yang, Xiaoping

    2014-12-01

    Phosphorus-doped tin oxides/carbon nanofibers (P-SnOx/CNFs) composite materials are prepared via electrospinning of a mixed solution composed of polyacrylonitrile (PAN), N,N-dimethyl formamide (DMF), tin tetrachloride, ethylene glycol and phosphoric acid as well as subsequent thermal treatments. The P-SnOx/CNFs samples with tunable P-doping contents are directly used as anodes for lithium-ion batteries without any binders and conductors, exhibiting enhanced reversible capacities and cycling stabilities in comparison with pristine undoped SnOx/CNFs (0P-SnOx/CNFs). In a controlled experiment, the 0.25P-SnOx/CNFs anode with the atomic ratio of P:Sn = 0.25:1 shows the highest specific reversible capacity of 676 mA h g-1 at 200 mA g-1 after 100 cycles. Even at a higher current density of 2000 mA g-1, it still maintains a superior specific reversible capacity of 288 mA h g-1. The improved electrochemical performances are attributed to the P-doping effects such as inducement of a stable structural protection for tin particles, and enhancement of lithium ion diffusion coefficient and electron kinetics of electrode materials.

  16. Isoniazid cocrystals with anti-oxidant hydroxy benzoic acids

    NASA Astrophysics Data System (ADS)

    Mashhadi, Syed Muddassir Ali; Yunus, Uzma; Bhatti, Moazzam Hussain; Tahir, Muhammad Nawaz

    2014-11-01

    Isoniazid is the primary constituent of “triple therapy” used to effectively treat tuberculosis. In tuberculosis and other diseases, tissue inflammation and free radical burst from macrophages results in oxidative stress. These free radicals cause pulmonary inflammation if not countered by anti-oxidants. Therefore, in the present study cocrystals of isoniazid with four anti-oxidant hydroxy benzoic acids have been reported. Gallic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, and 3-hydroxybenzoic acid resulted in the formation of cocrystals when reacted with isoniazid. Cocrystal structure analysis confirmed the existence of pyridine-carboxylic acid synthon in the cocrystals of isoniazid with Gallic acid, 2,3-dihydroxybenzoic acid and 3-hydroxybenzoic acid. While cocrystal of 3,5-dihydroxybenzoic acid formed the pyridine-hydroxy group synthon. Other synthons of different graph sets are formed between hydrazide group of isoniazid and coformers involving Nsbnd H⋯O and Osbnd H⋯N bonds. All the cocrystals were in 1:1 stoichiometric ratio.

  17. The effects of ketogenic diet on oxidative stress and antioxidative capacity markers of Taekwondo athletes.

    PubMed

    Rhyu, Hyun-Seung; Cho, Su-Youn; Roh, Hee-Tae

    2014-12-01

    The purpose of this study was to investigate the effects of the ketogenic diet through 3 weeks on oxidative stress and antioxidative capacity markers in Taekwondo athletes. The participants selected for this research were 18 high school taekwondo contestants aged 15-18 who had at least 5 yr of career as contestant. The subjects were randomly assigned to the ketogenic diet (KD) group and the Non ketogenic diet (NDK) group. Body composition and oxidative stress and antioxidative capacity markers (LDH, MDA, ROS, HDL, and SOD) were analysed before and after 3 weeks of ketogenic diet. No significant difference was found between the groups in body composition, ROS and SOD level. The KD group showed an elevated HDL level and NKD group showed an elevated LDH and MDA level after ketogenic diet by 3 weeks. This result suggests that weight loss by 3 weeks of calorie restriction and exercise can cause oxidative stress, and that ketogenic diet can be effective for preventing it. It could also be inferred that ketogenic diet can be effective for increasing blood antioxidative capacity. PMID:25610820

  18. The effects of ketogenic diet on oxidative stress and antioxidative capacity markers of Taekwondo athletes

    PubMed Central

    Rhyu, Hyun-seung; Cho, Su-Youn; Roh, Hee-Tae

    2014-01-01

    The purpose of this study was to investigate the effects of the ketogenic diet through 3 weeks on oxidative stress and antioxidative capacity markers in Taekwondo athletes. The participants selected for this research were 18 high school taekwondo contestants aged 15–18 who had at least 5 yr of career as contestant. The subjects were randomly assigned to the ketogenic diet (KD) group and the Non ketogenic diet (NDK) group. Body composition and oxidative stress and antioxidative capacity markers (LDH, MDA, ROS, HDL, and SOD) were analysed before and after 3 weeks of ketogenic diet. No significant difference was found between the groups in body composition, ROS and SOD level. The KD group showed an elevated HDL level and NKD group showed an elevated LDH and MDA level after ketogenic diet by 3 weeks. This result suggests that weight loss by 3 weeks of calorie restriction and exercise can cause oxidative stress, and that ketogenic diet can be effective for preventing it. It could also be inferred that ketogenic diet can be effective for increasing blood antioxidative capacity. PMID:25610820

  19. Photocatalytic Oxidation of Sulfurous Acid in an Aqueous Medium

    ERIC Educational Resources Information Center

    Romero, Alicia; Hernandez, Willie; Suarez, Marco F.

    2005-01-01

    The effect of some parameters on sulfurous acid and sulfur oxidation kinetics such as initial concentration of sulfurous acid, oxygen, TiO[2] crystalline concentration, the power of black light, and quantity of TiO[2] is investigated. The experiments can be performed in an undergraduate physical chemistry laboratory with an inexpensive…

  20. Pulsed sonication for alumina coatings on high-capacity oxides: Performance in lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Pol, Vilas G.; Li, Yan; Dogan, Fulya; Secor, Ethan; Thackeray, Michael M.; Abraham, Daniel P.

    2014-07-01

    High-capacity xLi2MnO3·(1 - x)LiMO2 (M = Ni, Mn, Co) oxides show relatively rapid performance degradation when cycled at voltages >4.5 V vs. Li/Li+. Previous research has indicated that modifying the oxide surfaces with coatings, such as alumina, reduces cell impedance rise and improves capacity retention. In this article, we demonstrate pulsed-sonication as a rapid and effective approach for coating alumina on Li1.2Ni0.175Mn0.525Co0.1O2 (0.5Li2MnO3·0.5LiNi0.44Mn0.31Co0.25O2) particles. Oxide integrity and morphology is maintained after the sonochemical process and subsequent heat-treatment. Energy dispersive spectroscopy (EDS) X-ray elemental maps show uniform coating of all secondary particles. 27Al Magic Angle Spinning (MAS) NMR data confirm the presence of alumina and mainly indicate octahedral aluminum occupancy in a six-coordinate environment with oxygen. Full cells containing electrodes with the alumina-coated particles demonstrate lower initial impedance rise and better capacity retention during extended cycling to high voltages. However, the coating has a negligible effect on the voltage hysteresis and voltage fade behavior displayed by these oxides. The various data indicate that the pulsed sonochemical technique is a viable approach for coating oxide particles. The methodology described herein can easily be extended beyond alumina to include coatings such as AlF3, MgO, and MgF2.

  1. Oxidation of oleic acid monolayers at air/liquid interfaces

    NASA Astrophysics Data System (ADS)

    Voss, Laura

    2008-03-01

    Field studies of marine and continental aerosols find that fatty acid films form on aqueous tropospheric aerosols. Oxidation of oleic acid monolayers by ozone was studied to understand the fate of fat-coated aerosols from both fresh and salt water sources. Using vibrational sum frequency generation spectroscopy and reflection absorption infrared spectroscopy, we present a molecular-level investigation of fatty acid monolayers at the air-water and air-sodium chloride solution interface and explore reactions with atmospheric oxidants by these model systems. Coupling sum frequency generation spectroscopy with a Langmuir trough, concurrent spectroscopic and thermodynamic data were collected to obtain a molecular picture of the monolayers. No substantial difference was observed between oxidation of monolayers spread on water and on 0.6 molar sodium chloride solutions. Results indicate that depending on the size of the aerosol and the extent of oxidation, the subsequent oxidation products may not remain at the surface of these films, but instead be dissolved in the aqueous sub-phase of the aerosol particle. Results also indicate that oxidation of oleic acid could produce monolayers containing species that have no oxidized acyl chains.

  2. Effects of the conversion of cropland to forest on the CH4 oxidation capacity in soils.

    NASA Astrophysics Data System (ADS)

    Bárcena, Teresa G.; D'Imperio, Ludovica; Priemé, Anders; Gundersen, Per; Vesterdal, Lars; Christiansen, Jesper R.

    2013-04-01

    As the second most important greenhouse gas (GHG) in the atmosphere, methane (CH4) plays a central role in global warming. Diverse types of soil have been reported as potential CH4 sinks due to the activity of methane oxidizing bacteria (MOB), underlining the importance of this functional group of microorganisms on a global basis. Agricultural practices are known to negatively affect CH4 oxidation in soil, while afforestation of former agricultural soils has been shown to enhance CH4 oxidation over time. However, knowledge is scarce with regard to the mechanisms driving the process of CH4 oxidation in different land uses. Our aim was to study the changes in CH4 uptake capacity in soils along a land-use change gradient from cropland to forest. We performed an incubation experiment to study the CH4 oxidation capacity of the top mineral soil (0-5 cm and 5-15 cm depth) for sites representing the transition from agriculture to afforestation based on monoculture of three tree species with different stand ages: pedunculate oak (4, 19, 42 and >200 years old), European larch (22 and 41 years old) and Norway spruce (15 and 43 years old). Main soil parameters were also measured to determine differences in soil properties between sites. Methane oxidation rates were related to the abundance of the soil methanotrophic community based on quantitative PCR (qPCR). In addition, we also estimated the abundance of ammonia-oxidizing bacteria (AOB) and archaea (AOA), in order to investigate the link between these two similar functional groups. Although present, the abundance of AOB was under detection limit. The effects and interactions among all measured variables were summarized by Principal Component Analysis (PCA). Along the gradient, CH4 oxidation increased with increasing stand age in both soil layers (ranging from 0-1.3 nmol g-1dw d-1). However, we detected significant differences, in particular between oak and spruce, suggesting a possible tree species effect on the CH4

  3. A stencil printed, high energy density silver oxide battery using a novel photopolymerizable poly(acrylic acid) separator.

    PubMed

    Braam, Kyle; Subramanian, Vivek

    2015-01-27

    A novel photopolymerized poly(acrylic acid) separator is demonstrated in a printed, high-energy-density silver oxide battery. The printed battery demonstrates a high capacity of 5.4 mA h cm(-2) at a discharge current density of 2.75 mA cm(-2) (C/2 rate) while delivering good mechanical flexibility and robustness. PMID:25475759

  4. Activating HSP72 in rodent skeletal muscle increases mitochondrial number and oxidative capacity and decreases insulin resistance.

    PubMed

    Henstridge, Darren C; Bruce, Clinton R; Drew, Brian G; Tory, Kálmán; Kolonics, Attila; Estevez, Emma; Chung, Jason; Watson, Nadine; Gardner, Timothy; Lee-Young, Robert S; Connor, Timothy; Watt, Matthew J; Carpenter, Kevin; Hargreaves, Mark; McGee, Sean L; Hevener, Andrea L; Febbraio, Mark A

    2014-06-01

    Induction of heat shock protein (HSP)72 protects against obesity-induced insulin resistance, but the underlying mechanisms are unknown. Here, we show that HSP72 plays a pivotal role in increasing skeletal muscle mitochondrial number and oxidative metabolism. Mice overexpressing HSP72 in skeletal muscle (HSP72Tg) and control wild-type (WT) mice were fed either a chow or high-fat diet (HFD). Despite a similar energy intake when HSP72Tg mice were compared with WT mice, the HFD increased body weight, intramuscular lipid accumulation (triacylglycerol and diacylglycerol but not ceramide), and severe glucose intolerance in WT mice alone. Whole-body VO2, fatty acid oxidation, and endurance running capacity were markedly increased in HSP72Tg mice. Moreover, HSP72Tg mice exhibited an increase in mitochondrial number. In addition, the HSP72 coinducer BGP-15, currently in human clinical trials for type 2 diabetes, also increased mitochondrial number and insulin sensitivity in a rat model of type 2 diabetes. Together, these data identify a novel role for activation of HSP72 in skeletal muscle. Thus, the increased oxidative metabolism associated with activation of HSP72 has potential clinical implications not only for type 2 diabetes but also for other disorders where mitochondrial function is compromised. PMID:24430435

  5. Stimulation of mitochondrial oxidative capacity in white fat independent of UCP1: a key to lean phenotype.

    PubMed

    Flachs, Pavel; Rossmeisl, Martin; Kuda, Ondrej; Kopecky, Jan

    2013-05-01

    We are facing a revival of the strategy to counteract obesity and associated metabolic disorders by inducing thermogenesis mediated by mitochondrial uncoupling protein-1 (UCP1). Thus, the main focus is on the adaptive non-shivering thermogenesis occurring both in the typical depots of brown adipose tissue (BAT) and in UCP1-containing cells that could be induced in white adipose tissue (WAT). Because contribution of WAT to resting metabolic rate is relatively small, the possibility to reduce adiposity by enhancing energy expenditure in classical white adipocytes is largely neglected. However, several pieces of evidence support a notion that induction of energy expenditure based on oxidation of fatty acids (FA) in WAT may be beneficial for health, namely: (i) studies in both humans and rodents document negative association between oxidative capacity of mitochondria in WAT and obesity; (ii) pharmacological activation of AMPK in rats as well as cold-acclimation of UCP1-ablated mice results in obesity resistance associated with increased oxidative capacity in WAT; and (iii) combined intervention using long-chain n-3 polyunsaturated FA (omega 3) and mild calorie restriction exerted synergism in the prevention of obesity in mice fed a high-fat diet; this was associated with strong hypolipidemic and insulin-sensitizing effects, as well as prevention of inflammation, and synergistic induction of mitochondrial oxidative phosphorylation (OXPHOS) and FA oxidation, specifically in epididymal WAT. Importantly, these changes occurred without induction of UCP1 and suggested the involvement of: (i) futile substrate cycle in white adipocytes, which is based on lipolysis of intracellular triacylglycerols and re-esterification of FA, in association with the induction of mitochondrial OXPHOS capacity, β-oxidation, and energy expenditure; (ii) endogenous lipid mediators (namely endocannabinoids, eicosanoids, prostanoids, resolvins, and protectins) and their cognate receptors; and (iii

  6. Stream chemistry in the eastern United States. 2. Current sources of acidity in acidic and low acid-neutralizing capacity streams

    SciTech Connect

    Herlihy, A.T.; Kaufmann, P.R.; Mitch, M.E. )

    1991-04-01

    The authors examined anion composition in National Stream Survey (NSS) data in order to evaluate the most probably sources of current acidity in acidic and low acid-neutralizing capacity (ANC) streams in the eastern US. Acidic streams that had almost no organic influence (less than 10% of total anions) and sulfate and nitrate concentrations indicative of evaporative concentration of atmospheric deposition were classified as acidic due to acidic deposition. These acidic streams were located in small (<30 km{sup 2}) forested watersheds in the Mid-Atlantic Highlands (an estimated 1,950 km of stream length) and in the Mid-Atlantic Coastal Plain (1,250 km). Acidic streams affected primarily by acidic deposition but also influenced by naturally occurring organic anions accounted for another 1,180 km of acidic stream length, and were located in the New Jersey Pine Barrens, plateau tops in the Mid-Atlantic and Southeast Highlands, and the Florida Panhandle. The total length of streams acidic due to acid mine drainage in the NSS (4,590 km) was about the same as the total length of acidic streams likely affected by acidic deposition (4,380 km). Acidic streams whose acid anion composition was dominated by organics were located in Florida and the Mid-Atlantic Coastal Plain. In Florida, most of the acidic streams were organic dominated, whereas about half of the streams in the Mid-Atlantic Coastal Plain were organic dominated. Organic-dominated acidic streams were not observed in the Mid-Atlantic and Southeast Highlands.

  7. Mitochondrial reserve capacity in endothelial cells: the impact of nitric oxide and reactive oxygen species

    PubMed Central

    Dranka, Brian P.; Hill, Bradford G.; Darley-Usmar, Victor M.

    2010-01-01

    The endothelium is not considered to be a major energy requiring organ, but nevertheless endothelial cells have an extensive mitochondrial network. This suggests that mitochondrial function may be important in response to stress and signaling in these cells. In this study, we used extracellular flux analysis to measure mitochondrial function in adherent bovine aortic endothelial cells (BAEC). Under basal conditions, BAEC use only ~35% of their maximal respiratory capacity. We calculate that this represents an intermediate respiratory State between States 3 and 4 which we define as Stateapparent equal to 3.64. Interestingly, the apparent respiratory control ratio (maximal mitochondrial oxygen consumption/non-ADP linked respiration) in these cells is on the order of 23 which is substantially higher than that which is frequently obtained with isolated mitochondria. These results suggest that mitochondria in endothelial cells are highly coupled and possess a considerable bioenergetic reserve. Since endothelial cells are exposed to both reactive oxygen and nitrogen species (ROS/RNS) in the course of vascular disease, we hypothesized that this reserve capacity is important in responding to oxidative stress. To test this, we exposed BAEC to NO or ROS alone or in combination. We found that exposure to non-toxic concentrations of NO or low levels of hydrogen peroxide generated from 2,3-dimethoxy-1,4-napthoquinone (DMNQ) had little impact on basal mitochondrial function but both treatments reversibly decreased mitochondrial reserve capacity. However, combined NO and DMNQ treatment resulted in an irreversible loss of reserve capacity and was associated with cell death. These data are consistent with a critical role of mitochondrial reserve capacity in endothelial cells in responding to oxidative stress. PMID:20093177

  8. Influence of organic acids on the pH and acid-neutralizing capacity of Adirondack Lakes

    NASA Astrophysics Data System (ADS)

    Munson, R. K.; Gherini, S. A.

    1993-04-01

    Past approaches for evaluating the effects of organic acids on the acid-base characteristics of surface waters have typically treated them solely as weak acids. Analysis of data collected by the Adirondack Lakes Survey Corporation (ALSC) from 1469 lakes throughout the Adirondack region shows that this approach is not valid. While the data indicate that natural organics contain a continuum of acid functional groups, many of which display weak acid characteristics, a significant fraction of the organic acid is strong (pKa < 3). Dissolved organic carbon (DOC) contributes 4.5-5 μeq/mg DOC of strong acid to solution. The associated anions make a negative contribution to Gran acid-neutralizing capacity (ANC). Because organic anions can produce negative Gran ANC values, the common practice of considering negative values of Gran ANC evidence of acidification solely by mineral acids is not valid. The strength of organic acids also influences the observed deviation between Gran ANC values and ANC values calculated as the difference between base cation and mineral acid anion concentrations (CB - CA). Ninety percent of the deviation is due to the presence of strong organics while the remaining 10% is due to DOC-induced curvature in the F1 Gran function. Organic acids can also strongly influence pH. Their largest effects were found in the 0-50 μeq/L Gran ANC range where they depressed pH by up to 1.5 units. In addition, a method for predicting changes in pH in response to changes in mineral acidity, DOC, or both without having to rely on inferred thermodynamic constants and the uncertainties associated with them has been developed. Using the predictive method, the response of representative lakes from four sensitive lake classes to a 15-μeq/L decrease in mineral acidity ranged from +0.17 to +0.38 pH units. If concurrent increases in DOC are considered, the pH changes would be even smaller.

  9. Bile acid binding capacity of fish protein hydrolysates from discard species of the West Mediterranean Sea.

    PubMed

    Pérez-Gálvez, Raúl; García-Moreno, Pedro J; Morales-Medina, Rocío; Guadix, Antonio; Guadix, Emilia M

    2015-04-01

    Fish protein hydrolysates (FPH), produced from the six main discard species from the West Mediterranean Sea (sardine, horse mackerel, axillary seabream, bogue, small-spotted catshark and blue whiting) were tested for their bile acid binding capacity. This capacity is directly linked to the ability to inhibit bile reabsorption in the ileum and therefore to lower cholesterol levels in the bloodstream. From each species, FPH were obtained by three different enzymatic treatments employing two serine endoproteases (subtilisin and trypsin) sequentially or in combination. The results show statistically significant differences among the fish species, attaining interesting average values of bile acid binding capacity for blue whiting (27.32% relative to cholestyramine on an equal protein basis) and horse mackerel (27.42% relative to cholestyramine on an equal protein basis). The enzymatic treatments did not significantly affect the ability of a given species to bind bile acids. These results are similar to other protein sources, such as soy protein or casein, of proven hypocholesterolemic effect. It can be concluded that fish protein hydrolysates from these discard species are suitable as ingredients in the formulation of cholesterol-lowering supplements. PMID:25756593

  10. Oxidized amino acids: culprits in human atherosclerosis and indicators of oxidative stress.

    PubMed

    Heinecke, Jay W

    2002-06-01

    Oxidized low-density lipoprotein (LDL) is implicated in atherogenesis, but the mechanisms that oxidize LDL in the human artery wall have proven difficult to identify. A powerful investigative approach is mass spectrometric quantification of the oxidized amino acids that are left in proteins by specific oxidation reactions. Comparison of these molecular fingerprints in biological samples with those produced in proteins by various in vitro oxidation systems can indicate which biochemical pathway has created damage in vivo. For example, the pattern of oxidized amino acids in proteins isolated from atherosclerotic lesions implicates reactive intermediates generated by myeloperoxidase, a major phagocyte enzyme. These intermediates include hypochlorous acid, tyrosyl radical, and reactive nitrogen species, each of which generates a different pattern of stable end products. Despite this strong evidence that myeloperoxidase promotes LDL oxidation in vivo, the antioxidant that has been tested most extensively in clinical trials, vitamin E, fails to inhibit myeloperoxidase pathways in vitro. Because the utility of an antioxidant depends critically on the nature of the pathway that inflicts tissue damage, interventions that specifically inhibit myeloperoxidase or other physiologically relevant pathways would be more logical candidates for the prevention of cardiovascular disease. Moreover, levels of oxidized amino acids in urine and plasma might reflect those in tissues and therefore identify individuals with high levels of oxidative stress. Trials with such subjects would seem more likely to uncover effective antioxidant therapies than trials involving the general population. PMID:12031894

  11. Studies on the oxidation of hexamethylbenzene 1: Oxidation of hexamethylbenzene with nitric acid

    NASA Technical Reports Server (NTRS)

    Chiba, K.; Tomura, S.; Mizuno, T.

    1986-01-01

    The oxidative reaction of hexamethylbenzene (HMB) with nitric acid was studied, and the hitherto unknown polymethylbenzenepolycarboxylic acids were isolated: tetramethylphthalic anhydride, tetramethylisophthalic acid, 1,3,5-, 1,2,4- and 1,2,3-trimethylbenzenetricarboxylic acids. When HMB was warmed with 50% nitric acid at about 80 C, tetramethylphthalic anhydride and tetramethylisophthalic acid were initially produced. The continued reaction led to the production of trimethylbenzenetricarboxylic acids, but only slight amounts of dimethylbenzenetetracarboxylic acids were detected in the reaction mixture. Whereas tetramethylphthalic anydride and tetramethylisophthalic acid were obtained, pentamethylbenzoic acid, a possible precursor of them, was scarcely produced. On the other hand, a yellow material extracted with ether from the initial reaction mixture contained bis-(nitromethyl)prehnitene (CH3)4C6(CH2NO2)2, which was easily converted into the phthalic anhydride.

  12. Antioxidant capacity of oat (Avena sativa L.) extracts. 1. Inhibition of low-density lipoprotein oxidation and oxygen radical absorbance capacity.

    PubMed

    Handelman, G J; Cao, G; Walter, M F; Nightingale, Z D; Paul, G L; Prior, R L; Blumberg, J B

    1999-12-01

    Milled oat groat pearlings, trichomes, flour, and bran were extracted with methanol and the fractions tested in vitro for antioxidant capacity against low-density lipoprotein (LDL) oxidation and R-phycoerythrin protein oxidation in the oxygen radical absorbance capacity (ORAC) assay. The oxidative reactions were generated by 2,2'-azobis(2-amidinopropane) HCl (AAPH) or Cu(2+) in the LDL assay and by AAPH or Cu(2+) + H(2)O(2) in the ORAC assay and calibrated against a Trolox standard to calculate Trolox equivalents (1 Trolox equivalent = 1 TE = activity of 1 micromol of Trolox). The antioxidant capacity of the oat fractions was generally consistent with a potency rank of pearlings (2.89-8.58 TE/g) > flour (1.00-3.54 TE/g) > trichome (1.74 TE/g) = bran (1.02-1.62 TE/g) in both LDL and ORAC assays regardless of the free radical generator employed. A portion of the oat antioxidant constituents may be heat labile as the greatest activity was found among non-steam-treated pearlings. The contribution of oat tocols from the fractions accounted for <5% of the measured antioxidant capacity. AAPH-initiated oxidation of LDL was inhibited by the oat fractions in a dose-dependent manner, although complete suppression was not achieved with the highest doses tested. In contrast, Cu(2+)-initiated oxidation of LDL stimulated peroxide formation with low oat concentrations but completely inhibited oxidation with higher doses. Thus, oats possess antioxidant capacity most of which is likely derived from polar phenolic compounds in the aleurone. PMID:10606548

  13. DNA damage and oxidative stress induced by acetylsalicylic acid in Daphnia magna.

    PubMed

    Gómez-Oliván, Leobardo Manuel; Galar-Martínez, Marcela; Islas-Flores, Hariz; García-Medina, Sandra; SanJuan-Reyes, Nely

    2014-08-01

    Acetylsalicylic acid is a nonsteroidal anti-inflammatory widely used due to its low cost and high effectiveness. This compound has been found in water bodies worldwide and is toxic to aquatic organisms; nevertheless its capacity to induce oxidative stress in bioindicators like Daphnia magna remains unknown. This study aimed to evaluate toxicity in D. magna induced by acetylsalicylic acid in water, using oxidative stress and DNA damage biomarkers. An acute toxicity test was conducted in order to determine the median lethal concentration (48-h LC50) and the concentrations to be used in the subsequent subacute toxicity test in which the following biomarkers were evaluated: lipid peroxidation, oxidized protein content, activity of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, and level of DNA damage. Lipid peroxidation level and oxidized protein content were significantly increased (p<0.05), and antioxidant enzymes significantly altered with respect to controls; while the DNA damage were significantly increased (p<0.05) too. In conclusion, acetylsalicylic acid induces oxidative stress and DNA damage in D. magna. PMID:24747829

  14. Oxidation of oleic acid at air/liquid interfaces

    NASA Astrophysics Data System (ADS)

    Voss, Laura F.; Bazerbashi, Mohamad F.; Beekman, Christopher P.; Hadad, Christopher M.; Allen, Heather C.

    2007-03-01

    Oxidation of oleic acid monolayers by ozone was studied to understand the fate of fat-coated aerosols from both freshwater and saltwater sources. Oleic acid monolayers at the air/water interface and at the air/sodium chloride solution interface were investigated using surface-specific, broad-bandwidth, sum frequency generation spectroscopy. Complementary techniques of infrared reflection adsorption spectroscopy and surface pressure measurements taken during monolayer oxidation confirmed the sum frequency results. Using this nonlinear optical technique coupled with a Langmuir trough, concurrent spectroscopic and thermodynamic data were collected to obtain a molecular picture of the monolayers. No substantial difference was observed between oxidation of monolayers spread on water and on 0.6 M sodium chloride solutions. Results indicate that depending on the size of the aerosol and the extent of oxidation, the subsequent oxidation products may not remain at the surface of these films, but instead be dissolved in the aqueous subphase of the aerosol particle. Results also indicate that oxidation of oleic acid could produce monolayers containing species that have no oxidized acyl chains.

  15. Oxidative damage to RPA limits the nucleotide excision repair capacity of human cells

    PubMed Central

    Guven, Melisa; Brem, Reto; Macpherson, Peter; Peacock, Matthew; Karran, Peter

    2015-01-01

    Nucleotide excision repair (NER) protects against sunlight-induced skin cancer. Defective NER is associated with photosensitivity and a high skin cancer incidence. Some clinical treatments that cause photosensitivity can also increase skin cancer risk. Among these, the immunosuppressant azathioprine and the fluoroquinolone antibiotics ciprofloxacin and ofloxacin, interact with UVA radiation to generate reactive oxygen species (ROS) that diminish NER capacity by causing protein damage. The RPA DNA binding protein plays a pivotal role in DNA metabolism and is an essential component of NER. The relationship between protein oxidation and NER inhibition was investigated in cultured human cells expressing different levels of RPA. We show here that RPA is limiting for NER and that oxidative damage to RPA compromises NER capability. Our findings reveal that cellular RPA is surprisingly vulnerable to oxidation and we identify oxidized forms of RPA that are associated with impaired NER. The vulnerability of NER to inhibition by oxidation provides a connection between cutaneous photosensitivity, protein damage and increased skin cancer risk. Our findings emphasize that damage to DNA repair proteins, as well as to DNA itself is likely to be an important contributor to skin cancer risk. PMID:26134950

  16. [Investigation on Inhibitory Capacities of Seventeen Herbal Extracts on Oxidative Stress using Ultraviolet and Fluorescence Spectroscopy].

    PubMed

    Hou, Guang-yue; Zheng, Zhong; Song, Feng-rui; Liu, Zhi-qiang; Zhao, Bing

    2015-03-01

    Diabetic patients usually suffer from complications and the long-term secondary complications are the main cause of morbidity and mortality. The hyperglycemia-induced oxidative stress is one of the important pathogenesis of diabetic complications, while the oxidative stress is associated with the lipid peroxidation reaction and the formation of advanced glycation end products (AGEs). Our study was focus on the pathogenesis of diabetic complications and based on the oxidative stress reaction. In this research, the oxidative stress inhibiting effects of seventeen herbal extracts were studied based on spectroscopic methodology. The capacities of herbal extracts against the lipid peroxidation reaction of rat liver in vitro were investigated using spectrophotometric method. It showed that the inhibitory activity of Radix Scutellariae and Flos Sophorae Immaturus were better than other herbal extracts. Additionally, the herbal extracts rich in flavonoids, alkaloids and lignanoids showed good inhibitory activities on the lipid peroxidation reaction. On the contrary, the saponin-rich herbal extracts possessed weak inhibitory effects. We applied the BSA/glucose (fructose) system combined with fluorescent spectroscopy to determine the inhibitory activities of herbal extracts in glycation model reactions. The results showed that the AGEs formation inhibitory activity of Flos Sophorae Immaturus, Radix Scutellariae and Rhizoma Anemarrhenae were better than others in the BSA/glucose (fructose) system by fluorescene analysis. The results demonstrated that the herbal extracts rich in flavonoids were found to be more effective than that of those herbal extracts as alkaloids and terpenoids class in inhibiting oxidative stress, while the saponin-rich herbal extracts showed weak inhibitory activities against oxidative stress. The Flos Sophorae Immaturus and Radix Scutellariae extracts had better inhibitory activity to the oxidative stress, so their pharmacological activity could be

  17. Biomarkers of oxidative damage and antioxidant defense capacity in Caiman latirostris blood.

    PubMed

    Poletta, Gisela L; Simoniello, María Fernanda; Mudry, Marta D

    2016-01-01

    Several xenobiotics, and among them pesticides, can produce oxidative stress, providing a mechanistic basis for their observed toxicity. Chronic oxidative stress induces deleterious modifications to DNA, lipids and proteins that are used as effective biomarkers to study pollutant-mediated oxidative stress. No previous report existed on the application of oxidative damage and antioxidant defense biomarkers in Caiman latirostris blood, while few studies reported in other crocodilians were done in organs or muscles of dead animals. The aim of this study was to characterize a new set of oxidative stress biomarkers in C. latirostris blood, through the modification of conventional techniques: 1) damage to lipids by thiobarbituric acid reactive substances (TBARS), 2) damage to DNA by comet assay modified with the enzymes FPG and Endo III, and 3) antioxidant defenses: catalase, superoxide dismutase and glutathione; in order to apply them in future biomonitoring studies. We successfully adapted standard procedures for CAT, SOD, GSH and TBARS determination in C. latirostris blood. Calibration curves for FPG and Endo III showed that the three dilutions tested were appropriate to conduct the modified comet assay for the detection of oxidized bases in C. latirostris erythrocytes. One hour of incubation allowed a complete repair of the damage generated. The incorporation of these biomarkers in biomonitoring studies of caiman populations exposed to xenobiotics is highly important considering that this species has recovered from a serious endangered state through the implementation of sustainable use programs in Argentina, and represents nowadays a relevant economic resource for many human communities. PMID:26299575

  18. Actovegin, a non-prohibited drug increases oxidative capacity in human skeletal muscle.

    PubMed

    Søndergård, Stine D; Dela, Flemming; Helge, Jørn W; Larsen, Steen

    2016-10-01

    Actovegin, a deproteinized haemodialysate of calf blood, is suggested to have ergogenic properties, but this potential effect has never been investigated in human skeletal muscle. To investigate this purported ergogenic effect, we measured the mitochondrial respiratory capacity in permeabilized human skeletal muscle fibres acutely exposed to Actovegin in a low and in a high dose. We found that Actovegin, in the presence of complex I-linked substrates increased the oxidative phosphorylation (OXPHOS) capacity significantly in a concentration-dependent manner (19 ± 3, 31 ± 4 and 45 ± 4 pmol/mg/s). Maximal OXPHOS capacity with complex I and II-linked substrate was increased when the fibres were exposed to the high dose of Actovegin (62 ± 6 and 77 ± 6 pmol/mg/s) (p < .05). The respiratory capacity of the electron transfer system as well as Vmax and Km were also increased in a concentration-dependent manner after Actovegin exposure (70 ± 6, 79 ± 6 and 88 ± 7 pmol/mg/s; 13 ± 2, 25 ± 3 and 37 ± 4 pmol/mg/s; 0.08 ± 0.02, 0.21 ± 0.03 and 0.36 ± 0.03 mM, respectively) (p < .05). In summary, we report for the first time that Actovegin has a marked effect on mitochondrial oxidative function in human skeletal muscle. Mitochondrial adaptations like this are also seen after a training program in human subjects. Whether this improvement translates into an ergogenic effect in athletes and thus reiterates the need to include Actovegin on the World Anti-Doping Agency's active list remains to be investigated. PMID:26744809

  19. Responses of soil buffering capacity to acid treatment in three typical subtropical forests.

    PubMed

    Jiang, Jun; Wang, Ying-Ping; Yu, Mengxiao; Li, Kun; Shao, Yijing; Yan, Junhua

    2016-09-01

    Elevated anthropogenic acid deposition can significantly affect forest ecosystem functioning by changing soil pH, nutrient balance, and chemical leaching and so on. These effects generally differ among different forests, and the dominant mechanisms for those observed responses often vary, depending on climate, soil conditions and vegetation types. Using soil monoliths (0-40cm) from pine forest (pioneer), coniferous and broadleaved mixed forest (transitional) and broadleaved forest (mature) in southern China, we conducted a leaching experiment with acid treatments at different pH levels (control: pH≈4.5; pH=3.5; pH=2.5). We found that pH3.5 treatment significantly reduced dissolved organic carbon (DOC) concentrations in leachate from the pioneer forest soil. pH2.5 treatment significantly increased concentrations of NO3(-), SO4(2-), Ca(2+), Mg(2+), Al(3+), Fe(3+) and DOC in leachate from the pioneer forest soil, and also concentrations of NO3(-), SO4(2-), Mg(2+), Al(3+), Fe(3+) and DOC in leachate from the transitional forest soil. All acid treatments had no significant effects on concentrations of these chemicals in leachate from the mature forest soil. The responses can be explained by the changes in soil pH, acid neutralizing capacity (ANC) and concentrations of Al and Fe. Our results showed that acid buffering capacity of the pioneer or transitional forest soil was lower than that of the mature forest soil. Therefore preserving mature forests in southern China is important for reducing the adverse impacts of high acid deposition on stream water quality at present and into the future. PMID:27185346

  20. Maximal oxygen uptake is proportional to muscle fiber oxidative capacity, from chronic heart failure patients to professional cyclists.

    PubMed

    van der Zwaard, Stephan; de Ruiter, Jo C; Noordhof, Dionne A; Sterrenburg, Renske; Bloemers, Frank W; de Koning, Jos J; Jaspers, Richard T; van der Laarse, Willem J

    2016-09-01

    V̇o2 max during whole body exercise is presumably constrained by oxygen delivery to mitochondria rather than by mitochondria's ability to consume oxygen. Humans and animals have been reported to exploit only 60-80% of their mitochondrial oxidative capacity at maximal oxygen uptake (V̇o2 max). However, ex vivo quantification of mitochondrial overcapacity is complicated by isolation or permeabilization procedures. An alternative method for estimating mitochondrial oxidative capacity is via enzyme histochemical quantification of succinate dehydrogenase (SDH) activity. We determined to what extent V̇o2 max attained during cycling exercise differs from mitochondrial oxidative capacity predicted from SDH activity of vastus lateralis muscle in chronic heart failure patients, healthy controls, and cyclists. V̇o2 max was assessed in 20 healthy subjects and 28 cyclists, and SDH activity was determined from biopsy cryosections of vastus lateralis using quantitative histochemistry. Similar data from our laboratory of 14 chronic heart failure patients and 6 controls were included. Mitochondrial oxidative capacity was predicted from SDH activity using estimated skeletal muscle mass and the relationship between ex vivo fiber V̇o2 max and SDH activity of isolated single muscle fibers and myocardial trabecula under hyperoxic conditions. Mitochondrial oxidative capacity predicted from SDH activity was related (r(2) = 0.89, P < 0.001) to V̇o2 max measured during cycling in subjects with V̇o2 max ranging from 9.8 to 79.0 ml·kg(-1)·min(-1) V̇o2 max measured during cycling was on average 90 ± 14% of mitochondrial oxidative capacity. We conclude that human V̇o2 max is related to mitochondrial oxidative capacity predicted from skeletal muscle SDH activity. Mitochondrial oxidative capacity is likely marginally limited by oxygen supply to mitochondria. PMID:27445298

  1. [Investigation on mechanism of pyrite oxidation in acidic solutions].

    PubMed

    Wang, Nan; Yi, Xiao-Yun; Dang, Zhi; Liu, Yun

    2012-11-01

    The mechanism of pyrite oxidation in acidic solutions was investigated by electrochemical analysis methods, such as open-circuit potential, cyclic voltammetry, Tafel polarization curve and anodic polarization curve, using a pyrite-carbon paste electrode as working electrode. The results showed that the oxidation process of pyrite in acidic solutions was via a two-step reaction: the first step was the dissolution of iron moiety and formation of a passivation film composed of elemental sulphur, metal-deficient sulfide and polysulfide; the second step was the further oxidation of these intermediate products to SO4(2-). The final reaction products of pyrite oxidation were Fe3+ and SO4(2-) in acidic solutions. In addition, the open-circuit potential and corrosion potential were positively shifted, the peak current and the corrosion current were increased with the increase in concentration of H2SO4 solutions. This indicated that increased acidity of the system was advantageous to the oxidation of pyrite. PMID:23323425

  2. Fatty Acid Beta-Oxidation Disorders: A Brief Review

    PubMed Central

    Vishwanath, Vijay A.

    2016-01-01

    Background Mitochondrial fatty acid β-oxidation disorders (FAODs) are a heterogeneous group of defects in fatty acid transport and mitochondrial β-oxidation. They are inherited as autosomal recessive disorders and have a wide range of clinical presentations. Summary The background information and case report provide important insight into mitochondrial FAODs. The article provides a wealth of information describing the scope of these disorders. Key Messages This article presents a typical case of medium chain acyl-CoA dehydrogenase deficiency and summarizes the pathophysiology, clinical presentation, diagnosis and treatment of mitochondrial FAODs.

  3. Wound repair and anti-oxidative capacity is regulated by ITGB4 in airway epithelial cells.

    PubMed

    Liu, Chi; Liu, Hui-jun; Xiang, Yang; Tan, Yu-rong; Zhu, Xiao-lin; Qin, Xiao-qun

    2010-08-01

    Integrin beta 4 (ITGB4) is a structural adhesion molecule which engages in maintaining the integrity of airway epithelial cells. Its specific cytomembrane structural feature strongly indicates that ITGB4 may engage in many signaling pathways and physiologic processes. However, in addition to adhesion, the specific biologic significance of ITGB4 in airway epithelial cells is almost unknown. In this article, we investigated the expression and functional properties of ITGB4 in airway epithelial cells in vivo and in vitro. Human bronchial epithelial cell line (16HBE14O-cells) and primary rat tracheal epithelial cells (RTE cells) were used to determine ITGB4 expression under ozone tress or mechanical damage, respectively. An ovalbumin (OVA)-challenged asthma model was used to investigate ITGB4 expression after antigen exposure in vivo. In addition, an ITGB4 overexpression vector and ITGB4 silence virus vector were constructed and transfected into RTE cells. Then, wound repair ability and anti-oxidation capacity was evaluated. Our results demonstrated that, on the edge of mechanically wounded cell areas, ITGB4 expression was increased after mechanical injury. After ozone stress, upregulation expression of ITGB4 was also detected. In the OVA-challenged asthma model, ITGB4 expression was decreased on airway epithelial cells accompanying with structural disruption and damage of anti-oxidation capacity. Besides, our study revealed that upregulation of ITGB4 promotes wound repair ability and anti-oxidative ability, while such abilities were blocked when ITGB4 was silenced. Taken together, these results showed that ITGB4 was a new interesting molecule involved in the regulation of wound repair and anti-oxidation processes for airway epithelial cells. PMID:20364299

  4. Biomarkers of oxidative stress and its association with the urinary reducing capacity in bus maintenance workers

    PubMed Central

    2011-01-01

    Background Exposure to particles (PM) induces adverse health effects (cancer, cardiovascular and pulmonary diseases). A key-role in these adverse effects seems to be played by oxidative stress, which is an excess of reactive oxygen species relative to the amount of reducing species (including antioxidants), the first line of defense against reactive oxygen species. The aim of this study was to document the oxidative stress caused by exposure to respirable particles in vivo, and to test whether exposed workers presented changes in their urinary levels for reducing species. Methods Bus depot workers (n = 32) exposed to particles and pollutants (respirable PM4, organic and elemental carbon, particulate metal content, polycyclic aromatic hydrocarbons, NOx, O3) were surveyed over two consecutive days. We collected urine samples before and after each shift, and quantified an oxidative stress biomarker (8-hydroxy-2'-deoxyguanosine), the reducing capacity and a biomarker of PAH exposure (1-hydroxypyrene). We used a linear mixed model to test for associations between the oxidative stress status of the workers and their particle exposure as well as with their urinary level of reducing species. Results Workers were exposed to low levels of respirable PM4 (range 25-71 μg/m3). However, urinary levels of 8-hydroxy-2'-deoxyguanosine increased significantly within each shift and between both days for non-smokers. The between-day increase was significantly correlated (p < 0.001) with the concentrations of organic carbon, NOx, and the particulate copper content. The within-shift increase in 8OHdG was highly correlated to an increase of the urinary reducing capacity (Spearman ρ = 0.59, p < 0.0001). Conclusions These findings confirm that exposure to components associated to respirable particulate matter causes a systemic oxidative stress, as measured with the urinary 8OHdG. The strong association observed between urinary 8OHdG with the reducing capacity is suggestive of protective

  5. Selective oxidation of glycerol under acidic conditions using gold catalysts

    SciTech Connect

    Villa, Alberto; Veith, Gabriel M; Prati, Laura

    2010-01-01

    H-mordenite-supported PtAu nanoparticles are highly active and selective in the oxidation of glycerol under acidic conditions, which allows the direct preparation of free acids (see picture). The high selectivity for C{sub 3} compounds results from the negligible formation of H{sub 2}O{sub 2}, in contrast to PtAu nanoparticles supported on activated carbon.

  6. Oxidative cleavage of erucic acid for the synthesis of brassylic acid

    SciTech Connect

    Mohammed J. Nasrullah; Pooja Thapliyal; Erica N. Pfarr; Nicholas S. Dusek; Kristofer L. Schiele; James A. Bahr

    2010-10-29

    The main focus of this work is to synthesize Brassylic Acid (BA) using oxidative cleavage of Erucic Acid (EA). Crambe (Crambe abyssinica) is an industrial oilseed grown in North Dakota. Crambe has potential as an industrial fatty acid feedstock as a source of Erucic acid (EA). It has approximately 50-60 % of EA, a C{sub 22} monounsaturated fatty acid. Oxidative cleavage of unsaturated fatty acids derived from oilseeds produces long chain (9, 11, and 13 carbon atoms) dibasic and monobasic acids. These acids are known commercial feedstocks for the preparation of nylons, polyesters, waxes, surfactants, and perfumes. Other sources of EA are Rapeseed seed oil which 50-60 % of EA. Rapeseed is grown outside USA. The oxidative cleavage of EA was done using a high throughput parallel pressure reactor system. Kinetics of the reaction shows that BA yields reach a saturation at 12 hours. H{sub 2}WO{sub 4} was found to be the best catalyst for the oxidative cleavage of EA. High yields of BA were obtained at 80 C with bubbling of O{sub 2} or 10 bar of O{sub 2} for 12 hours.

  7. CUEDC2 modulates cardiomyocyte oxidative capacity by regulating GPX1 stability.

    PubMed

    Jian, Zhao; Liang, Bing; Pan, Xin; Xu, Guang; Guo, Sai-Sai; Li, Ting; Zhou, Tao; Xiao, Ying-Bin; Li, Ai-Ling

    2016-01-01

    The irreversible loss of cardiomyocytes due to oxidative stress is the main cause of heart dysfunction following ischemia/reperfusion (I/R) injury and ageing-induced cardiomyopathy. Here, we report that CUEDC2, a CUE domain-containing protein, plays a critical role in oxidative stress-induced cardiac injury. Cuedc2(-/-) cardiomyocytes exhibited a greater resistance to oxidative stress-induced cell death. Loss of CUEDC2 enhanced the antioxidant capacity of cardiomyocytes, promoted reactive oxygen species (ROS) scavenging, and subsequently inhibited the redox-dependent activation of signaling pathways. Notably, CUEDC2 promoted E3 ubiquitin ligases tripartite motif-containing 33 (TRIM33)-mediated the antioxidant enzyme, glutathione peroxidase 1 (GPX1) ubiquitination, and proteasome-dependent degradation. Ablation of CUEDC2 upregulated the protein level of GPX1 in the heart significantly. Strikingly, in vivo, the infarct size of Cuedc2(-/-) heart was significantly decreased after I/R injury, and aged Cuedc2(-/-) mice preserved better heart function as the overall ROS levels in their hearts were significantly lower. Our results demonstrated a novel role of CUEDC2 in cardiomyocyte death regulation. Manipulating CUEDC2 level might be an attractive therapeutic strategy for promoting cardiomyocyte survival following oxidative stress-induced cardiac injury. PMID:27286733

  8. Impact of lipid oxidation-derived aldehydes and ascorbic acid on the antioxidant activity of model melanoidins.

    PubMed

    Kitrytė, Vaida; Adams, An; Venskutonis, Petras Rimantas; De Kimpe, Norbert

    2012-12-01

    As the heat-induced formation of antioxidants throughout the Maillard reaction is known, this study was undertaken to evaluate the impact of lipid oxidation-derived aldehydes and ascorbic acid in Maillard model systems on the resulting antioxidant activity. For this purpose, various fractions of melanoidin-like polycondensation products were obtained from mixtures of amino acids (glycine, lysine, arginine) and lipid oxidation-derived aldehydes (hexanal, (E)-2-hexenal), in the presence or absence of glucose or ascorbic acid. All fractions showed a significant radical scavenging capacity (DPPH assay) and ferric reducing power (FRAP assay). The activity varied according to the composition of the model system tested, although some similar trends were discovered in both assays applied. The presence of lipid oxidation products in the browning products augmented the antioxidant activity in specific cases. For instance, the combined presence of arginine, hexanal and glucose in heated model systems resulted in a significantly higher antioxidant capacity. With an exception of ascorbic acid-containing model systems, melanoidin-like polycondensation products possessed significantly stronger antioxidant activities than the corresponding unheated initial reactant mixtures. Water-soluble high molecular weight (>12kDa) and nonsoluble fractions comprised the major part of the antioxidants derived from amino acid/lipid oxidation product model systems, with or without glucose or ascorbic acid. PMID:22953854

  9. Effect of surface acidity and basicity of aluminas on asphaltene adsorption and oxidation.

    PubMed

    Nassar, Nashaat N; Hassan, Azfar; Pereira-Almao, Pedro

    2011-08-01

    This study investigates the effect of surface acidity and basicity of aluminas on asphaltene adsorption followed by air oxidation. Equilibrium batch adsorption experiments were conducted at 25°C with solutions of asphaltenes in toluene at concentrations ranging from 100 to 3000 g/L using three conventional alumina adsorbents with different surface acidity. Data were found to better fit to the Freundlich isotherm model showing a multilayer adsorption. Results showed that asphaltene adsorption is strongly affected by the surface acidity, and the adsorption capacities of asphaltenes onto the three aluminas followed the order acidic>basic and neutral. Asphaltenes adsorbed over aluminas were subjected to oxidation in air up to 600°C in a thermogravimetric analyzer to study the catalytic effect of aluminas with different surface acidity. A correlation was found between Freundlich affinity constant (1/n) and the catalytic activity. Basic alumina that has the lowest 1/n value, depicting strongest interactions, has the highest catalytic activity, followed by neutral and acidic aluminas, respectively. PMID:21571295

  10. Evaluating ion exchange resin efficiency and oxidative capacity for the separation of uranium(IV) and uranium(VI)

    PubMed Central

    2013-01-01

    Background Previously described methods to separate dissolved U(IV) from dissolved U(VI) under acidic anoxic conditions prior to laboratory analysis were ineffective with materials currently available commercially. Three strong anion exchange resins were examined for their efficiency in separating, recovering, and preserving both redox states during separation. Results Under oxic conditions, recovery of U(VI) from three exchange resins (Bio-Rad AG® 1x8 Poly-Prep® prefilled columns, Bio-Rad AG® 1x8 powder, and Dowex® 1x8 powder) ranged from 72% to 100% depending on the dosed mass, eluent volume, and resin selected. Dowex® 1x8 resin was the only resin found to provide 100% recovery of U(VI) with fewer than 5 bed volumes of eluent. Under anoxic conditions, all three resins oxidized U(IV) in aqueous solutions with relatively low U(IV) concentrations (<3x10-6 M). Resin-induced oxidation was observed visually using a leuco dye, safranin-o. Oxidants associated with the resin were irreversibly reduced by the addition of Ti(III). After anoxic resin pre-treatment, a series of U(IV)/U(VI) mixtures at micro-molar levels were prepared and separated using the Dowex® 1x8 resin with 100% recovery of both U(IV) and U(VI) with no resin-induced changes in oxidation state. Conclusions Currently available anion exchange resins with apparently identical physical properties were found to have significantly different recoveries for hexavalent uranium at micro-molar concentrations. A novel qualitative technique was developed to visually assess oxidative capacities of anion exchange resins under acidic anoxic conditions. A protocol was developed for pre-treatment and use of currently available anion exchange resins to achieve quantitative separation of U(IV) and U(VI) in aqueous solutions with low U(IV) concentrations. This method can be applied to future work to quantitatively assess dissolved U(IV) and U(VI) concentrations in both laboratory and field samples. PMID:23363052

  11. Rare earth element partitioning between hydrous ferric oxides and acid mine water during iron oxidation

    USGS Publications Warehouse

    Verplanck, P.L.; Nordstrom, D.K.; Taylor, H.E.; Kimball, B.A.

    2004-01-01

    Ferrous iron rapidly oxidizes to Fe (III) and precipitates as hydrous Fe (III) oxides in acid mine waters. This study examines the effect of Fe precipitation on the rare earth element (REE) geochemistry of acid mine waters to determine the pH range over which REEs behave conservatively and the range over which attenuation and fractionation occur. Two field studies were designed to investigate REE attenuation during Fe oxidation in acidic, alpine surface waters. To complement these field studies, a suite of six acid mine waters with a pH range from 1.6 to 6.1 were collected and allowed to oxidize in the laboratory at ambient conditions to determine the partitioning of REEs during Fe oxidation and precipitation. Results from field experiments document that even with substantial Fe oxidation, the REEs remain dissolved in acid, sulfate waters with pH below 5.1. Between pH 5.1 and 6.6 the REEs partitioned to the solid phases in the water column, and heavy REEs were preferentially removed compared to light REEs. Laboratory experiments corroborated field data with the most solid-phase partitioning occurring in the waters with the highest pH. ?? 2004 Elsevier Ltd. All rights reserved.

  12. Vitamins, fatty acids, and antioxidant capacity stability during storage of freeze-dried human milk.

    PubMed

    Lozano, Blanca; Castellote, Ana Isabel; Montes, Rosa; López-Sabater, M Carmen

    2014-09-01

    Although freezing is the most common method used to preserve human milk, nutritional and immunological components may be lost during storage. Freeze-drying could increase the shelf life of human milk, while preserving its original characteristics. Seventy-two samples of freeze-dried human milk were stored for different periods of time, up to a maximum of 3 months, at 4 °C or 40 °C. Vitamin C, tocopherols, antioxidant capacity, and fatty acids composition were analyzed. A new HILIC-UHPLC method improving vitamin C determination was also validated. Ascorbic acid and total vitamin C concentrations significantly decreased at both temperatures, while antioxidant capacity only decreased at 40 °C. Fatty acids composition and both γ-tocopherol and δ-tocopherol contents remained unaltered. The stability after storage of freeze-dried milk was higher than that reported for frozen or fresh milk indicating that freeze-drying is a promising option to improve the preservation of human milk in banks. PMID:24840090

  13. Effects of tocotrienol-rich fraction on exercise endurance capacity and oxidative stress in forced swimming rats.

    PubMed

    Lee, Shu-Ping; Mar, Guang-Yuan; Ng, Lean-Teik

    2009-11-01

    The present study aimed to examine the effects of tocotrienol-rich fraction (TRF) on exercise endurance and oxidative stress in forced swimming rats. Rats fed on isocaloric diet were orally given 25 (TRF-25) and 50 (TRF-50) mg/kg of TRF, or 25 mg/kg D-alpha-tocopherol (T-25) whilst the control group received only the vehicle for 28 days, followed by being forced to undergo swimming endurance tests, with measurements taken of various biochemical parameters, including blood glucose, lactate and urea nitrogen, glycogen, total antioxidant capacity, antioxidant enzymes, thiobarbituric acid-reactive substances (TBARS), and protein carbonyl. Results showed that the TRF-treated animals (268.0 +/- 24.1 min for TRF-25 and 332.5 +/- 24.3 min for TRF-50) swam significantly longer than the control (135.5 +/- 32.9 min) and T-25-treated (154.1 +/- 36.4 min) animals, whereas there was no difference in the performance between the T-25 and control groups. The TRF-treated rats also showed significantly higher concentrations of liver glycogen, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as of muscle glycogen and SOD than the control and the T-25-treated animals, but lower levels in blood lactate, plasma and liver TBARS, and liver and muscle protein carbonyl. Taken together, these results suggest that TRF is able to improve the physiological condition and reduce the exercise-induced oxidative stress in forced swimming rats. PMID:19705143

  14. Magnetic properties, acid neutralization capacity, and net acid production of rocks in the Animas River Watershed Silverton, Colorado

    USGS Publications Warehouse

    McCafferty, Anne E.; Yager, Douglas B.; Horton, Radley M.; Diehl, Sharon F.

    2006-01-01

    Federal land managers along with local stakeholders in the Upper Animas River watershed near Silverton, Colorado are actively designing and implementing mine waste remediation projects to mitigate the effects of acid mine drainage from several abandoned hard rock metal mines and mills. Local source rocks with high acid neutralization capacity (ANC) within the watershed are of interest to land managers for use in these remediation projects. A suite of representative samples was collected from propylitic to weakly sericitic-altered volcanic and plutonic rocks exposed in outcrops throughout the watershed. Acid-base accounting laboratory methods coupled with mineralogic and geochemical characterization provide insight into lithologies that have a range of ANC and net acid production (NAP). Petrophysical lab determinations of magnetic susceptibility converted to estimates for percent magnetite show correlation with the environmental properties of ANC and NAP for many of the lithologies. A goal of our study is to interpret watershed-scale airborne magnetic data for regional mapping of rocks that have varying degrees of ANC and NAP. Results of our preliminary work are presented here.

  15. Local capillary supply in muscle is not determined by local oxidative capacity.

    PubMed

    Bosutti, Alessandra; Egginton, Stuart; Barnouin, Yoann; Ganse, Bergita; Rittweger, Jörn; Degens, Hans

    2015-11-01

    It is thought that the prime determinant of global muscle capillary density is the mean oxidative capacity. However, feedback control during maturational growth or adaptive remodelling of local muscle capillarisation is likely to be more complex than simply matching O2 supply and demand in response to integrated tissue function. We tested the hypothesis that the maximal oxygen consumption (MO2,max) supported by a capillary is relatively constant, and independent of the volume of tissue supplied (capillary domain). We demonstrate that local MO2,max assessed by succinate dehydrogenase histochemistry: (1) varied more than 100-fold between individual capillaries and (2) was positively correlated to capillary domain area in both human vastus lateralis (R=0.750, P<0.001) and soleus (R=0.697, P<0.001) muscles. This suggests that, in contrast to common assumptions, capillarisation is not primarily dictated by local oxidative capacity, but rather by factors such as fibre size, or consequences of differences in fibre size such as substrate delivery and metabolite removal. PMID:26385326

  16. Fish Oil Contaminated with Persistent Organic Pollutants Reduces Antioxidant Capacity and Induces Oxidative Stress without Affecting Its Capacity to Lower Lipid Concentrations and Systemic Inflammation in Rats123

    PubMed Central

    Hong, Mee Young; Lumibao, Jan; Mistry, Prashila; Saleh, Rhonda; Hoh, Eunha

    2015-01-01

    Background: Numerous studies have investigated the benefits of fish, fish oil, and ω-3 (n–3) polyunsaturated fatty acids against cardiovascular diseases. However, concern surrounding contamination with persistent organic pollutants (POPs) prompts caution in the recommendation to consume fish and fish oil. Objective: The present study compared the effects of fish oil contaminated with polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) on serum lipid profiles, inflammation, and oxidative stress. Methods: Twenty eight-day-old male Sprague-Dawley rats (n = 30) consumed diets of unmodified fish oil (FO) consisting of 15% fat by weight, persistent organic pollutant–contaminated fish oil (POP FO) (PCBs at 2.40 μg/g; OCs at 3.80 μg/g FO), or corn oil (control; CO) for 9 wk. Lipid profiles and C-reactive protein concentrations were assessed. Hepatic gene expression related to lipid metabolism was determined by real time quantitative polymerase chain reaction analysis. Results: After 9 wk of feeding, accumulation of PCBs and OCs in the fat tissue of the POP FO group compared with the other 2 groups was confirmed (P < 0.01). Both fish oil groups showed greater HDL cholesterol (FO 53 ± 5.3 and POP FO 55 ± 7.7 vs. CO 34 ± 2.3 mg/dL), but lower triglycerides (24 ± 2.8 and 22 ± 3.0 vs. 43 ± 5.6 mg/dL), LDL cholesterol (38 ± 14 and 34 ± 9.2 vs. 67 ± 4.4 mg/dL), and C-reactive protein (113 ± 20 and 120 ± 26 vs. 189 ± 22 μg/dL) compared with the CO group (P < 0.05). Gene expression of fatty acid synthase in both fish oil groups was also less than in the CO group (P < 0.05). However, the POP FO group showed greater lipid peroxidation (5.1 ± 0.7 vs. 2.9 ± 0.9 and 2.6 ± 0.6 μM) and less antioxidant capacity (0.08 ± 0.06 vs. 0.5 ± 0.1 and 0.4 ± 0.1 mM) than the CO and FO groups (P < 0.05). Conclusions: These findings indicate that, despite exhibiting benefits on serum lipid concentrations and inflammation, contamination with PCBs and OCs

  17. An in vitro study on the antioxidant capacity of usnic acid on human erythrocytes and molecular models of its membrane.

    PubMed

    Suwalsky, M; Jemiola-Rzeminska, M; Astudillo, C; Gallardo, M J; Staforelli, J P; Villena, F; Strzalka, K

    2015-11-01

    Usnic acid (UA) has been associated with chronic diseases through its antioxidant action. Its main target is the cell membrane; however, its effect on that of human erythrocytes has been scarcely investigated. To gain insight into the molecular mechanisms of the interaction between UA and cell membranes human erythrocytes and molecular models of its membrane have been utilized. Dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE) were chosen as representative of phospholipid classes located in the outer and inner monolayers of the erythrocyte membrane, respectively. Results by X-ray diffraction showed that UA produced structural perturbations on DMPC and DMPE bilayers. DSC studies have indicated that thermotropic behavior of DMPE was most strongly distorted by UA than DMPC, whereas the latter is mainly affected on the pretransition. Scanning electron (SEM) and defocusing microscopy (DM) showed that UA induced alterations to erythrocytes from the normal discoid shape to echinocytes. These results imply that UA molecules were located in the outer monolayer of the erythrocyte membrane. Results of its antioxidant properties showed that UA neutralized the oxidative capacity of HClO on DMPC and DMPE bilayers; SEM, DM and hemolysis assays demonstrated the protective effect of UA against the deleterious oxidant effects of HClO upon human erythrocytes. PMID:26299817

  18. Humic Acid-Oxidizing, Nitrate-Reducing Bacteria in Agricultural Soils

    PubMed Central

    Van Trump, J. Ian; Wrighton, Kelly C.; Thrash, J. Cameron; Weber, Karrie A.; Andersen, Gary L.; Coates, John D.

    2011-01-01

    ABSTRACT This study demonstrates the prevalence, phylogenetic diversity, and physiology of nitrate-reducing microorganisms capable of utilizing reduced humic acids (HA) as electron donors in agricultural soils. Most probable number (MPN) enumeration of agricultural soils revealed large populations (104 to 106 cells g−1 soil) of microorganisms capable of reducing nitrate while oxidizing the reduced HA analog 2,6-anthrahydroquinone disulfonate (AH2DS) to its corresponding quinone. Nitrate-dependent HA-oxidizing organisms isolated from agricultural soils were phylogenetically diverse and included members of the Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Advective up-flow columns inoculated with corn plot soil and amended with reduced HA and nitrate supported both HA oxidation and enhanced nitrate reduction relative to no-donor or oxidized HA controls. The additional electron donating capacity of reduced HA could reasonably be attributed to the oxidation of reduced functional groups. Subsequent 16S rRNA gene-based high-density oligonucleotide microarray (PhyloChip) indicated that reduced HA columns supported the development of a bacterial community enriched with members of the Acidobacteria, Firmicutes, and Betaproteobacteria relative to the no-donor control and initial inoculum. This study identifies a previously unrecognized role for HA in stimulating denitrification processes in saturated soil systems. Furthermore, this study indicates that reduced humic acids impact soil geochemistry and the indigenous bacterial community composition. PMID:21750120

  19. Excessive fatty acid oxidation induces muscle atrophy in cancer cachexia.

    PubMed

    Fukawa, Tomoya; Yan-Jiang, Benjamin Chua; Min-Wen, Jason Chua; Jun-Hao, Elwin Tan; Huang, Dan; Qian, Chao-Nan; Ong, Pauline; Li, Zhimei; Chen, Shuwen; Mak, Shi Ya; Lim, Wan Jun; Kanayama, Hiro-Omi; Mohan, Rosmin Elsa; Wang, Ruiqi Rachel; Lai, Jiunn Herng; Chua, Clarinda; Ong, Hock Soo; Tan, Ker-Kan; Ho, Ying Swan; Tan, Iain Beehuat; Teh, Bin Tean; Shyh-Chang, Ng

    2016-06-01

    Cachexia is a devastating muscle-wasting syndrome that occurs in patients who have chronic diseases. It is most commonly observed in individuals with advanced cancer, presenting in 80% of these patients, and it is one of the primary causes of morbidity and mortality associated with cancer. Additionally, although many people with cachexia show hypermetabolism, the causative role of metabolism in muscle atrophy has been unclear. To understand the molecular basis of cachexia-associated muscle atrophy, it is necessary to develop accurate models of the condition. By using transcriptomics and cytokine profiling of human muscle stem cell-based models and human cancer-induced cachexia models in mice, we found that cachectic cancer cells secreted many inflammatory factors that rapidly led to high levels of fatty acid metabolism and to the activation of a p38 stress-response signature in skeletal muscles, before manifestation of cachectic muscle atrophy occurred. Metabolomics profiling revealed that factors secreted by cachectic cancer cells rapidly induce excessive fatty acid oxidation in human myotubes, which leads to oxidative stress, p38 activation and impaired muscle growth. Pharmacological blockade of fatty acid oxidation not only rescued human myotubes, but also improved muscle mass and body weight in cancer cachexia models in vivo. Therefore, fatty acid-induced oxidative stress could be targeted to prevent cancer-induced cachexia. PMID:27135739

  20. Machine learning and hurdle models for improving regional predictions of stream water acid neutralizing capacity

    NASA Astrophysics Data System (ADS)

    Povak, Nicholas A.; Hessburg, Paul F.; Reynolds, Keith M.; Sullivan, Timothy J.; McDonnell, Todd C.; Salter, R. Brion

    2013-06-01

    In many industrialized regions of the world, atmospherically deposited sulfur derived from industrial, nonpoint air pollution sources reduces stream water quality and results in acidic conditions that threaten aquatic resources. Accurate maps of predicted stream water acidity are an essential aid to managers who must identify acid-sensitive streams, potentially affected biota, and create resource protection strategies. In this study, we developed correlative models to predict the acid neutralizing capacity (ANC) of streams across the southern Appalachian Mountain region, USA. Models were developed using stream water chemistry data from 933 sampled locations and continuous maps of pertinent environmental and climatic predictors. Environmental predictors were averaged across the upslope contributing area for each sampled stream location and submitted to both statistical and machine-learning regression models. Predictor variables represented key aspects of the contributing geology, soils, climate, topography, and acidic deposition. To reduce model error rates, we employed hurdle modeling to screen out well-buffered sites and predict continuous ANC for the remainder of the stream network. Models predicted acid-sensitive streams in forested watersheds with small contributing areas, siliceous lithologies, cool and moist environments, low clay content soils, and moderate or higher dry sulfur deposition. Our results confirmed findings from other studies and further identified several influential climatic variables and variable interactions. Model predictions indicated that one quarter of the total stream network was sensitive to additional sulfur inputs (i.e., ANC < 100 µeq L-1), while <10% displayed much lower ANC (<50 µeq L-1). These methods may be readily adapted in other regions to assess stream water quality and potential biotic sensitivity to acidic inputs.

  1. How Is the Oxidative Capacity of the Cloud Aqueous Phase Modified By Bacteria?

    NASA Astrophysics Data System (ADS)

    Deguillaume, L.; Mouchel-Vallon, C.; Passananti, M.; Wirgot, N.; Joly, M.; Sancelme, M.; Bianco, A.; Cartier, N.; Brigante, M.; Mailhot, G.; Delort, A. M.; Chaumerliac, N. M.

    2014-12-01

    The aqueous phase photochemical reactions of constituents present in atmospheric water like H2O2, NO3-, NO2- and Fe(III) aqua-complexes or organic complexes can form radicals such as the hydroxyl radical HO within the water drop. However, the literature lacks of data precising the rate of HO formation and the relative contribution of the photochemical sources of HO. The production of radicals in cloud aqueous phase drives the oxidative capacity of the cloud medium and the efficiency of organic matter oxidation. The oxidation of organic compounds is suspected to lead to oxygenated species that could contribute to secondary organic aerosol (SOA) mass (Ervens et al., 2011). In current cloud chemistry models, HO concentrations strongly depend on the organic and iron amount. For high concentrations of organic compounds, this radical is efficiently consumed during the day due to the oxidation process. When iron concentrations are typical from continental cloud, the photolysis of Fe(III) complexes and the Fenton reaction drive the HO concentrations in the cloud models. The concept of biocatalysed reactions contributing to atmospheric chemistry as an alternative route to photochemistry is quite new (Vaïtilingom et al., 2013); it emerged from the recent discovery of metabolically active microorganisms in clouds. Microorganisms are well-known to degrade organic matter but they could also interact with oxidant species such as H2O2 (or their precursors) thanks to their oxidative and nitrosative stress metabolism that will act directly on these species and on their interactions with iron (metalloproteins and siderophores). For the moment, biological impact on radical chemistry within cloud has not been yet considered in cloud chemistry models. Bacterial activity will be introduced as catalysts in a multiphase cloud chemistry model using degradation rates measured in the laboratory. For example, biodegradation rates of the oxidants H2O2 by model bacteria will be tested in the

  2. Lycopene synergistically inhibits LDL oxidation in combination with vitamin E, glabridin, rosmarinic acid, carnosic acid, or garlic.

    PubMed

    Fuhrman, B; Volkova, N; Rosenblat, M; Aviram, M

    2000-01-01

    Several lines of evidence suggest that oxidatively modified low-density lipoprotein (LDL) is atherogenic, and that atherosclerosis can be attenuated by natural antioxidants, which inhibit LDL oxidation. This study was conducted to determine the effect of tomato lycopene alone, or in combination with other natural antioxidants, on LDL oxidation. LDL (100 microg of protein/ml) was incubated with increasing concentrations of lycopene or of tomato oleoresin (lipid extract of tomatoes containing 6% lycopene, 0.1% beta-carotene, 1% vitamin E, and polyphenols), after which it was oxidized by the addition of 5 micromol/liter of CuSO4. Tomato oleoresin exhibited superior capacity to inhibit LDL oxidation in comparison to pure lycopene, by up to five-fold [97% vs. 22% inhibition of thiobarbituric acid reactive substances (TBARS) formation, and 93% vs. 27% inhibition of lipid peroxides formation, respectively]. Because tomato oleoresin also contains, in addition to lycopene, vitamin E, flavonoids, and phenolics, a possible cooperative interaction between lycopene and such natural antioxidants was studied. A combination of lycopene (5 micromol/liter) with vitamin E (alpha-tocopherol) in the concentration range of 1-10 micromol/liter resulted in an inhibition of copper ion-induced LDL oxidation that was significantly greater than the expected additive individual inhibitions. The synergistic antioxidative effect of lycopene with vitamin E was not shared by gamma-to-cotrienol. The polyphenols glabridin (derived from licorice), rosmarinic acid or carnosic acid (derived from rosemary), as well as garlic (which contains a mixture of natural antioxidants) inhibited LDL oxidation in a dose-dependent manner. When lycopene (5 micromol/liter) was added to LDL in combination with glabridin, rosmarinic acid, carnosic acid, or garlic, synergistic antioxidative effects were obtained against LDL oxidation induced either by copper ions or by the radical generator AAPH. Similar interactive

  3. Uranyl ion uptake capacity of poly (N-isopropylacrylamide/maleic acid) copolymeric hydrogels prepared by gamma rays

    NASA Astrophysics Data System (ADS)

    Kam, Erol; Taşdelen, Betul; Osmanlioglu, A. Erdal

    2012-06-01

    The effect of gel composition, absorbed dose and pH of the solution on the uranyl ion uptake capacity of N-isopropylacrylamide/maleic acid copolymeric hydrogels containing 0-3 mol% of maleic acid at 48 kGy have been investigated. Uranyl uptake capacity of hydrogels are found to increase from 18.5 to 94.8 mg [UO22+]/g dry gel as the mole % of maleic acid content in the gel structure increased from 0 to 3. The percent swelling, equilibrium swelling and diffusion coefficient values have been evaluated for poly(N-isopropylacrylamide/maleic acid) hydrogels at 500 ppm of uranyl nitrate solution.

  4. Limited capacity for glucose oxidation in fetal sheep with intrauterine growth restriction.

    PubMed

    Brown, Laura D; Rozance, Paul J; Bruce, Jennifer L; Friedman, Jacob E; Hay, William W; Wesolowski, Stephanie R

    2015-10-15

    Intrauterine growth-restricted (IUGR) fetal sheep, produced by placental insufficiency, have lower oxygen concentrations, higher lactate concentrations, and increased hepatic glucose production that is resistant to suppression by insulin. We hypothesized that increased lactate production in the IUGR fetus results from reduced glucose oxidation, during basal and maximal insulin-stimulated conditions, and is used to support glucose production. To test this, studies were performed in late-gestation control (CON) and IUGR fetal sheep under basal and hyperinsulinemic-clamp conditions. The basal glucose oxidation rate was similar and increased by 30-40% during insulin clamp in CON and IUGR fetuses (P < 0.005). However, the fraction of glucose oxidized was 15% lower in IUGR fetuses during basal and insulin-clamp periods (P = 0.05). IUGR fetuses also had four-fold higher lactate concentrations (P < 0.001) and lower lactate uptake rates (P < 0.05). In IUGR fetal muscle and liver, mRNA expression of pyruvate dehydrogenase kinase (PDK4), an inhibitor of glucose oxidation, was increased over fourfold. In IUGR fetal liver, but not skeletal muscle, mRNA expression of lactate dehydrogenase A (LDHA) was increased nearly fivefold. Hepatic expression of the gluconeogenic genes, phosphoenolpyruvate carboxykinase (PCK)1, and PCK2, was correlated with expression of PDK4 and LDHA. Collectively, these in vivo and tissue data support limited capacity for glucose oxidation in the IUGR fetus via increased PDK4 in skeletal muscle and liver. We speculate that lactate production also is increased, which may supply carbon for glucose production in the IUGR fetal liver. PMID:26224688

  5. Effect of Dietary n − 3 Polyunsaturated Fatty Acids on Oxidant/Antioxidant Status in Macrosomic Offspring of Diabetic Rats

    PubMed Central

    Guermouche, B.; Soulimane-Mokhtari, N. A.; Bouanane, S.; Merzouk, H.; Merzouk, S.; Narce, M.

    2014-01-01

    The aim of this work was to determine the effect of dietary n − 3 PUFA on oxidant/antioxidant status, in vitro very low and low density lipoprotein (VLDL-LDL), and VLDL-LDL-fatty acid composition in macrosomic pups of diabetic mothers. We hypothesized that n − 3 PUFA would improve oxidative stress in macrosomia. Diabetes was induced in female Wistar rats fed with the ISIO diet (control) or with the EPAX diet (enriched in n − 3 PUFAs), by streptozotocin. The macrosomic pups were killed at birth (day 0) and at adulthood (day 90). Lipid parameters and VLDL-LDL-fatty acid composition were investigated. The oxidant/antioxidant status was determined by measuring plasma oxygen radical absorbance capacity (ORAC), hydroperoxides, carbonyl proteins, and VLDL-LDL oxidation. Macrosomic rats of ISIO fed diabetic mothers showed an increase in plasma and VLDL-LDL-triglycerides and VLDL-LDL-cholesterol levels and altered VLDL-LDL-fatty acid composition. Plasma ORAC was low with high hydroperoxide and carbonyl protein levels. The in vitro oxidizability of VLDL-LDL was enhanced in these macrosomic rats. The EPAX diet corrected lipid parameters and improved oxidant/antioxidant status but increased VLDL-LDL susceptibility to oxidation. Macrosomia is associated with lipid abnormalities and oxidative stress. n − 3 PUFA exerts favorable effects on lipid metabolism and on the oxidant/antioxidant status of macrosomic rats. However, there are no evident effects on VLDL-LDL oxidation. PMID:24987679

  6. Endothelial cytoprotection from oxidized LDL by some crude Melanesian plant extracts is not related to their antioxidant capacity.

    PubMed

    Owen, Patrick L; Matainaho, Teatulohi; Sirois, Martin; Johns, Timothy

    2007-01-01

    Habitual consumption of some Melanesian medicinal and food plants may influence atherosclerosis development via their antioxidant capacity at the endothelial level. Areca nut (AN; Areca catechu), piper inflorescence (PBI; Piper betle), betel quid (BQ), guava buds (GB; Psidium guajava), the leaves (NL), juice (NJ), fruit (NF), and root (NR) of noni (Morinda citrifolia), the propagules of raw (MBR), and cooked (MBC) mangrove (Bruguiera gymnorrhiza) were evaluated for their ability to scavenge the 1,1-diphenyl-2-picryl-hydrazyle (DPPH) radical, to protect human low-density lipoprotein (LDL) from Cu2+-catalyzed oxidation and to protect cultured bovine aortal endothelial cells (BAEC) from oxidized LDL (oxLDL)-induced cytotoxicity. Polyphenol-rich extracts AN, PBI, and BQ were potent DPPH scavengers, having similar activity to quercetin and able to protect LDL from oxidation in a dose-dependent manner at concentrations higher than 10 microg/mL, but were pro-oxidants at lower concentrations. These extracts were cytotoxic to BAEC at concentrations above 10 microg/mL and were unable to prevent oxLDL endotheliopathy. GB and NR at 10 mug/mL displayed both the ability to delay LDL oxidation and prevent oxLDL cytotoxicity, although the latter lacked the ability to scavenge the DPPH radical. At higher concentrations, however, both were cytotoxic in themselves. The remaining noni extracts NF, NJ, NL, and both mangrove extracts MBC and MBR were unable to protect LDL from oxidation at all tested concentrations, but were effective cytoprotective agents at 50 microg/mL. All extracts were able to prevent an oxLDL-mediated increase in intracellular aldehyde generation but had little effect on extracellular peroxidation as measured by thiobarbituric acid reactive substances (TBARS). On the basis of this model system, we conclude that the antioxidant benefits of AN, PBI, and BQ may be offset by their enhancement of their cytotoxic effects of oxLDL toward BAEC, whereas GB and low

  7. Stemflow acid neutralization capacity in a broadleaved deciduous forest: the role of edge effects.

    PubMed

    Shiklomanov, Alexey N; Levia, Delphis F

    2014-10-01

    Atmospheric deposition is an important pathway for moisture, nutrient, and pollutant exchange among the atmosphere, forest, and soils. Previous work has shown the importance of proximity to the forest edge to chemical fluxes in throughfall, but far less research has considered stemflow. This study examined the difference in acid neutralization capacity (ANC) of stemflow of nineteen Liriodendron tulipifera L. (yellow poplar) trees between the forest edge and interior in a rural area of northeastern Maryland. We measured ANC directly via potentiometric titration. Stemflow from trees at the forest edge was found to have significantly higher and more variable pH and ANC than in the forest interior (p < 0.01). No mathematical trend between ANC and distance to the forest edge was observed, indicating the importance of individual tree characteristics in stemflow production and chemistry. These results reaffirm the importance of stemflow for acid neutralization by deciduous tree species. PMID:25005886

  8. Chapter A6. Section 6.6. Alkalinity and Acid Neutralizing Capacity

    USGS Publications Warehouse

    Rounds, Stewart A.; Wilde, Franceska D.

    2002-01-01

    Alkalinity (determined on a filtered sample) and Acid Neutralizing Capacity (ANC) (determined on a whole-water sample) are measures of the ability of a water sample to neutralize strong acid. Alkalinity and ANC provide information on the suitability of water for uses such as irrigation, determining the efficiency of wastewater processes, determining the presence of contamination by anthropogenic wastes, and maintaining ecosystem health. In addition, alkalinity is used to gain insights on the chemical evolution of an aqueous system. This section of the National Field Manual (NFM) describes the USGS field protocols for alkalinity/ANC determination using either the inflection-point or Gran function plot methods, including calculation of carbonate species, and provides guidance on equipment selection.

  9. Amino Acid Degradations Produced by Lipid Oxidation Products.

    PubMed

    Hidalgo, Francisco J; Zamora, Rosario

    2016-06-10

    Differently to amino acid degradations produced by carbohydrate-derived reactive carbonyls, amino acid degradations produced by lipid oxidation products are lesser known in spite of being lipid oxidation a major source of reactive carbonyls in food. This article analyzes the conversion of amino acids into Strecker aldehydes, α-keto acids, and amines produced by lipid-derived free radicals and carbonyl compounds, as well as the role of lipid oxidation products on the reactions suffered by these compounds: the formation of Strecker aldehydes and other aldehydes from α-keto acids; the formation of Strecker aldehydes and olefins from amines; the formation of shorter aldehydes from Strecker aldehydes; and the addition reactions suffered by the olefins produced from the amines. The relationships among all these reactions and the effect of reaction conditions on them are discussed. This knowledge should contribute to better control food processing in order to favor the formation of desirable beneficial compounds and to inhibit the production of compounds with deleterious properties. PMID:25748518

  10. Antioxidant capacity and fatty acid composition of different parts of Adenocarpus complicatus (Fabaceae) from Turkey.

    PubMed

    Berber, Adnan; Zengin, Gokhan; Aktumsek, Abdurrahman; Sanda, Murad Aydin; Uysal, Tuna

    2014-03-01

    Adenocarpus complicatus is distributed throughout the Anatolian peninsula and is widely used for human and animal nutrition. The purpose of this work was to study the antioxidant properties and fatty acid composition of different parts of this plant (fruits and mixed materials). The species was collected from Golyuzu village of the Seydisehir district near Konya province, Turkey. Fruit and mixed parts obtained from this species were ground and a 15g sample was used to prepare methanolic extracts. Powdered plant samples were extracted with 100mL methanol in a mechanical shaker. The obtained extracts were filtered and concentrated to dryness under reduced pressure and were subsequently stored at -20 degrees C. Antioxidant components, namely total phenolic and flavonoid content, were detected for each extract using spectrophotometric methods. Antioxidant capacity was evaluated by various assays including phosphomolybdenum, DPPH free radical scavenging capacity, metal chelating activity, and ferric and cupric ion reducing power. The fatty acid profiles of plant parts were also determined by using gas chromatography. The total phenolic content of fruit (36.21mgGAE/g) was higher than that of mixed materials (13.79mgGAE/g). The methanolic extract of mixed material had higher amounts of flavonoid than fruit extract. The free radical scavenging activity of extracts was expressed as IC50 value (microg/mL) (amount required to inhibit DPPH radical formation by 50%). The lower IC50 value reflects better free radical scavenging action. The radical scavenging activity of the samples was compared with BHT, it showed the mixed material to be almost two times more potent than the fruit extract. However, BHT is an excellent free radical scavenger with an IC50 of 34.061 microg/mL. The ferric and cupric reducing power potentials of the extracts were expressed as EC50 value (the effective concentration at which the absorbance was 0.5). Fruit extract exhibited strong ferric reducing

  11. Acidic Ultrafine Tungsten Oxide Molecular Wires for Cellulosic Biomass Conversion.

    PubMed

    Zhang, Zhenxin; Sadakane, Masahiro; Hiyoshi, Norihito; Yoshida, Akihiro; Hara, Michikazu; Ueda, Wataru

    2016-08-22

    The application of nanocatalysis based on metal oxides for biomass conversion is of considerable interest in fundamental research and practical applications. New acidic transition-metal oxide molecular wires were synthesized for the conversion of cellulosic biomass. The ultrafine molecular wires were constructed by repeating (NH4 )2 [XW6 O21 ] (X=Te or Se) along the length, exhibiting diameters of only 1.2 nm. The nanowires dispersed in water and were observed using high-angle annular dark-field scanning transmission electron microscopy. Acid sites were created by calcination without collapse of the molecular wire structure. The acidic molecular wire exhibited high activity and stability and promoted the hydrolysis of the glycosidic bond. Various biomasses including cellulose were able to be converted to hexoses as main products. PMID:27482857

  12. Oxidative degradation of organic acids conjugated with sulfite oxidation in flue gas desulfurization

    SciTech Connect

    Lee, Y.I.

    1986-01-01

    Organic acid degradation conjugated with sulfite oxidation has been studied under flue gas desulfurization (EGD) conditions. The oxidative degradation constant, k/sub 12/, is defined as the ratio of organic acid degradation rate and sulfite oxidation rate after being normalized by the concentrations of organic acid and dissolved S(IV). K/sub 12/, not significantly affected by pH or dissolved oxygen, is around 10/sup -3/ in the absence of manganese or iron. However, k/sub 12/ is increased by certain transition metals such as Co, Ni, and Fe and is decreased by Mn and halides. Lower dissolved S(IV) magnified these effects. No k/sub 12/ greater than 4 x 10/sup -3/ or smaller than 0.1 x 10/sup -3/ has been observed. A free radical mechanism was proposed to describe the kinetics: (1) sulfate free radical is the major radical responsible to the degradation of organic acid; (2) ferrous generates sulfate radical by reacting with monoxypersulfate to enhance k/sub 12/; (3) manganous consumes sulfate radical to decrease k/sub 12/; (4) dissolved S(IV) competes with ferrous for monoxypersulfate and with manganous for sulfate radical to demonstrate the effects of dissolved S(IV) on k/sub 12/. Hydroxy and sulfonated carboxylic acids degrade approximately three times slower than saturated dicarboxylic acids; while maleic acid, an unsaturated dicarboxylic acid, degraded an order of magnitude faster. A wide spectrum of degradation products of adipic acid were found, including carbon dioxide - the major product, glutaric semialdehyde - the major retained product with low manganese, glutaric acid and valeric acids - the major retained product with high manganese, lower molecular weight mono- and dicarboxylic acids, other carbonyl compounds, and hydrocarbons.

  13. Brain capacity for repair of oxidatively damaged DNA and preservation of neuronal function.

    PubMed

    Englander, Ella W

    2008-01-01

    Accumulation of oxidative DNA damage in the human brain has been implicated in etiologies of post-traumatic and age-associated declines in neuronal function. In neurons, because of high metabolic rates and prolonged life span, exposure to free radicals is intense and risk for accumulation of damaged DNA is amplified. While data indicate that the brain is equipped to repair nuclear and mitochondrial DNA, it is unclear whether repair is executed by distinct subsets of the DNA-repair machinery. Likewise, there are no firm assessments of brain capacity for accurate DNA repair under normal and more so compromised conditions. Consequently, the scope of DNA repair in the brain and the impact of resolution of oxidative lesions on neuronal survival and function remain largely unknown. This review considers evidences for brain levels and activities of the base excision repair (BER) pathway in the context of newly available, comprehensive in situ hybridization analyses of genes encoding repair enzymes. These analyses suggest that not all subsets of BER are equally represented in the brain. Because BER is the major repair process for oxidatively damaged DNA, to what extent parsimonious BER may contribute to development of neuronal dysfunction and brain injury under compromised conditions, is discussed. PMID:18374390

  14. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid.

    PubMed

    Wang, Lingling; Han, Changseok; Nadagouda, Mallikarjuna N; Dionysiou, Dionysios D

    2016-08-01

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2·6H2O functionalization of zeolite 4A. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The synthesized materials were characterized by porosimetry analysis, scanning electron microscopy, X-Ray diffraction analysis, and high resolution transmission electron microscopy. The maximum adsorption capacity of the adsorbents at 21±1°C was about 60mgCg(-1). The results showed that the positive charge density of ZnO-coated zeolite adsorbents was proportional to the amount of ZnO coated on zeolite and thus, ZnO-coated zeolite adsorbents exhibited a greater affinity for negatively charged ions. Furthermore, the adsorption capacity of ZnO-coated zeolite adsorbents increased markedly after acid modification. Adsorption experiments demonstrated ZnO-coated zeolite adsorbents possessed high adsorption capacity to remove HA from aqueous solutions mainly due to strong electrostatic interactions between negative functional groups of HA and the positive charges of ZnO-coated zeolite adsorbents. PMID:27135170

  15. Enhanced antiinflammatory capacity of a Lactobacillus plantarum mutant synthesizing modified teichoic acids

    PubMed Central

    Grangette, Corinne; Nutten, Sophie; Palumbo, Emmanuelle; Morath, Siegfried; Hermann, Corinna; Dewulf, Joelle; Pot, Bruno; Hartung, Thomas; Hols, Pascal; Mercenier, Annick

    2005-01-01

    Teichoic acids (TAs), and especially lipoteichoic acids (LTAs), are one of the main immunostimulatory components of pathogenic Gram-positive bacteria. Their contribution to the immunomodulatory properties of commensal bacteria and especially of lactic acid bacteria has not yet been investigated in detail. To evaluate the role of TAs in the interaction between lactic acid bacteria and the immune system, we analyzed the antiinflammatory properties of a mutant of Lactobacillus plantarum NCIMB8826 affected in the TA biosynthesis pathway both in vitro (mononuclear cells stimulation) and in vivo (murine model of colitis). This Dlt- mutant was found to incorporate much less d-Ala in its TAs than the WT strain. This defect significantly impacted the immunomodulation reactions induced by the bacterium, as shown by a dramatically reduced secretion of proinflammatory cytokines by peripheral blood mononuclear cells and monocytes stimulated by the Dlt- mutant as compared with the parental strain. Concomitantly, a significant increase in IL-10 production was stimulated by the Dlt- mutant in comparison with the WT strain. Moreover, the proinflammatory capacity of L. plantarum-purified LTA was found to be Toll-like receptor 2-dependent. Consistent with the in vitro results, the Dlt- mutant was significantly more protective in a murine colitis model than its WT counterpart. The results indicated that composition of LTA within the whole-cell context of L. plantarum can modulate proinflammatory or antiinflammatory immune responses. PMID:15985548

  16. Biochemical properties of porcine white adipose tissue mitochondria and relevance to fatty acid oxidation.

    PubMed

    Koekemoer, T C; Oelofsen, W

    2001-07-01

    The capacity of white adipose tissue mitochondria to support a high beta-oxidative flux was investigated by comparison to liver mitochondria. Based on marker enzyme activities and electron microscopy, the relative purity of the isolated mitochondria was similar thus allowing a direct comparison on a protein basis. The results confirm the comparable capacity of adipose tissue and liver mitochondria for palmitoyl-carnitine oxidation. Relative to liver, both citrate synthase and alpha-ketoglutarate dehydrogenase were increased 7.87- and 10.38-fold, respectively. In contrast, adipose tissue NAD-isocitrate dehydrogenase was decreased (2.85-fold). Such modifications in the citric acid cycle are expected to severely restrict citrate oxidation in porcine adipose tissue. Except for cytochrome c oxidase, activities of the enzyme complexes comprising the electron transport chain were not significantly different. The decrease in adipose cytochrome c oxidase activity could partly be attributed to a decreased inner membrane as suggested by lipid and enzyme analysis. In addition, Western blotting indicated that adipose and liver mitochondria possess similar quantities of cytochrome c oxidase protein. Taken together these results indicate that not only is the white adipose tissue protoplasm relatively rich in mitochondria, but that these mitochondria contain comparable enzymatic machinery to support a relatively high beta-oxidative rate. PMID:11435134

  17. Phytic acid prevents oxidative stress in seeds: evidence from a maize (Zea mays L.) low phytic acid mutant.

    PubMed

    Doria, Enrico; Galleschi, Luciano; Calucci, Lucia; Pinzino, Calogero; Pilu, Roberto; Cassani, Elena; Nielsen, Erik

    2009-01-01

    A maize mutant defective in the synthesis of phytic acid during seed maturation was used as a tool to study the consequences of the lack of this important reserve substance on seed survival. Data on germinability, free iron level, free radical relative abundance, protein carbonylation level, damage to DNA, degree of lipid peroxidation, alpha- and gamma-tocopherol amount and antioxidant capacity were recorded on seeds of maize B73 and of an isogenic low phytic acid mutant (lpa1-241), either unaged or incubated for 7 d in accelerated ageing conditions (46 degrees C and 100% relative humidity). The lpa1-241 mutant, compared to wild type (wt), showed a lower germination capacity, which decreased further after accelerated ageing. Whole lpa1-241 mutant kernels contained about 50% more free or weakly bound iron than wt ones and showed a higher content of free radicals, mainly concentrated in embryos; in addition, upon accelerated ageing, lpa1-241 seed proteins were more carbonylated and DNA was more damaged, whereas lipids did not appear to be more peroxidated, but the gamma-tocopherol content was decreased by about 50%. These findings can be interpreted in terms of previously reported but never proven antioxidant activity of phytic acid through iron complexation. Therefore, a novel role in plant seed physiology can be assigned to phytic acid, that is, protection against oxidative stress during the seed's life span. As in maize kernels the greater part of phytic acid (and thus of metal ions) is concentrated in the embryo, its antioxidant action may be of particular relevance in this crop. PMID:19204030

  18. Effect of sulfonylureas on hepatic fatty acid oxidation

    SciTech Connect

    Patel, T.B.

    1986-08-01

    In isolated rat livers perfused with oleic acid (0.1 mM), infusion of tolbutamide or glyburide decreased the rate of ketogenesis in a dose-dependent manner. The inhibition of fatty acid oxidation was maximal at 2.0 mM and 10 M concentrations of tolbutamide and glyburide, respectively. Neither tolbutamide nor glyburide inhibited ketogenesis in livers perfused with octanoate. The inhibition of hepatic ketogenesis by sulfonylureas was independent of perfusate oleic acid concentration. Additionally, in rat livers perfused with oleic acid in the presence of L-(-)-carnitine (10 mM), submaximal concentrations of tolbutamide and glyburide did not inhibit hepatic ketogenesis. Finally, glyburide infusion into livers perfused with (U- $C)oleic acid (0.1 mM) increased the rate of UC label incorporation into hepatic triglycerides by 2.5-fold. These data suggest that both tolbutamide and glyburide inhibit long-chain fatty acid oxidation by inhibition the key regulatory enzyme, carnitine palmitoyltransferase I, most probably by competing with L-(-)-carnitine.

  19. Surface oxide growth on platinum electrode in aqueous trifluoromethanesulfonic acid.

    PubMed

    Furuya, Yoshihisa; Mashio, Tetsuya; Ohma, Atsushi; Dale, Nilesh; Oshihara, Kenzo; Jerkiewicz, Gregory

    2014-10-28

    Platinum in the form of nanoparticles is the key and most expensive component of polymer electrolyte membrane fuel cells, while trifluoromethanesulfonic acid (CF3SO3H) is the smallest fluorinated sulfonic acid. Nafion, which acts as both electrolyte and separator in fuel cells, contains -CF2SO3H groups. Consequently, research on the electrochemical behaviour of Pt in aqueous CF3SO3H solutions creates important background knowledge that can benefit fuel cell development. In this contribution, Pt electro-oxidation is studied in 0.1 M aqueous CF3SO3H as a function of the polarization potential (E(p), 1.10 ≤ E(p) ≤ 1.50 V), polarization time (t(p), 10(0) ≤ t(p) ≤ 10(4) s), and temperature (T, 278 ≤ T ≤ 333 K). The critical thicknesses (X1), which determines the applicability of oxide growth theories, is determined and related to the oxide thickness (d(ox)). Because X1 > d(ox) for the entire range of E(p), t(p), and T values, the formation of Pt surface oxide follows the interfacial place-exchange or the metal cation escape mechanism. The mechanism of Pt electro-oxidation is revised and expanded by taking into account possible interactions of cations, anions, and water molecules with Pt. A modified kinetic equation for the interfacial place exchange is proposed. The application of the interfacial place-exchange and metal cation escape mechanisms leads to an estimation of the Pt(δ+)-O(δ-) surface dipole (μ(PtO)), and the potential drop (V(ox)) and electric field (E(ox)) within the oxide. The Pt-anion interactions affect the oxidation kinetics by indirectly influencing the electric field within the double layer and the surface oxide. PMID:25362330

  20. Surface oxide growth on platinum electrode in aqueous trifluoromethanesulfonic acid

    NASA Astrophysics Data System (ADS)

    Furuya, Yoshihisa; Mashio, Tetsuya; Ohma, Atsushi; Dale, Nilesh; Oshihara, Kenzo; Jerkiewicz, Gregory

    2014-10-01

    Platinum in the form of nanoparticles is the key and most expensive component of polymer electrolyte membrane fuel cells, while trifluoromethanesulfonic acid (CF3SO3H) is the smallest fluorinated sulfonic acid. Nafion, which acts as both electrolyte and separator in fuel cells, contains -CF2SO3H groups. Consequently, research on the electrochemical behaviour of Pt in aqueous CF3SO3H solutions creates important background knowledge that can benefit fuel cell development. In this contribution, Pt electro-oxidation is studied in 0.1 M aqueous CF3SO3H as a function of the polarization potential (Ep, 1.10 ≤ Ep ≤ 1.50 V), polarization time (tp, 100 ≤ tp ≤ 104 s), and temperature (T, 278 ≤ T ≤ 333 K). The critical thicknesses (X1), which determines the applicability of oxide growth theories, is determined and related to the oxide thickness (dox). Because X1 > dox for the entire range of Ep, tp, and T values, the formation of Pt surface oxide follows the interfacial place-exchange or the metal cation escape mechanism. The mechanism of Pt electro-oxidation is revised and expanded by taking into account possible interactions of cations, anions, and water molecules with Pt. A modified kinetic equation for the interfacial place exchange is proposed. The application of the interfacial place-exchange and metal cation escape mechanisms leads to an estimation of the Ptδ+-Oδ- surface dipole (μPtO), and the potential drop (Vox) and electric field (Eox) within the oxide. The Pt-anion interactions affect the oxidation kinetics by indirectly influencing the electric field within the double layer and the surface oxide.

  1. Protective effect of vitamin E on sperm motility and oxidative stress in valproic acid treated rats.

    PubMed

    Ourique, Giovana M; Saccol, Etiane M H; Pês, Tanise S; Glanzner, Werner G; Schiefelbein, Sun Hee; Woehl, Viviane M; Baldisserotto, Bernardo; Pavanato, Maria A; Gonçalves, Paulo B D; Barreto, Kátia P

    2016-09-01

    Long-term administration of valproic acid (VPA) is known to promote reproductive impairment mediated by increase in testicular oxidative stress. Vitamin E (VitE) is a lipophilic antioxidant known to be essential for mammalian spermatogenesis. However, the capacity of this vitamin to abrogate the VPA-mediated oxidative stress has not yet been assessed. In the current study, we evaluated the protective effect of VitE on functional abnormalities related to VPA-induced oxidative stress in the male reproductive system. VPA (400 mg kg(-1)) was administered by gavage and VitE (50 mg kg(-1)) intraperitoneally to male Wistar rats for 28 days. Analysis of spermatozoa from the cauda epididymides was performed. The testes and epididymides were collected for measurement of oxidative stress biomarkers. Treatment with VPA induced a decrease in sperm motility accompanied by an increase in oxidative damage to lipids and proteins, depletion of reduced glutathione and a decrease in total reactive antioxidant potential on testes and epididymides. Co-administration of VitE restored the antioxidant potential and prevented oxidative damage on testes and epididymides, restoring sperm motility. Thus, VitE protects the reproductive system from the VPA-induced damage, suggesting that it may be a useful compound to minimize the reproductive impairment in patients requiring long-term treatment with VPA. PMID:27424124

  2. Determination of total antioxidant capacity of humic acids using CUPRAC, Folin-Ciocalteu, noble metal nanoparticle- and solid-liquid extraction-based methods.

    PubMed

    Karadirek, Şeyda; Kanmaz, Nergis; Balta, Zeynep; Demirçivi, Pelin; Üzer, Ayşem; Hızal, Jülide; Apak, Reşat

    2016-06-01

    Total antioxidant capacity (TAC) of humic acid (HA) samples was determined using CUPRAC (CUPric Reducing Antioxidant Capacity), FC (Folin-Ciocalteu), QUENCHER-CUPRAC, QUENCHER-FC, Ag-NP (Silver nanoparticle)‒ and Au-NP (Gold nanoparticle)‒based methods. Conventional FC and modified FC (MFC) methods were applied to solid samples. Because of decreased solubility of Folin-Ciocalteu's phenol reagent in organic solvents, solvent effect on TAC measurement was investigated using QUENCHER-CUPRAC assay by using ethanol:distilled water and dimethyl sulfoxide:distilled water with varying ratios. To see the combined effect of solubilization (leaching) and TAC measurement of humic acids simultaneously, QUENCHER experiments were performed at 25°C and 50°C; QUENCHER-CUPRAC and QUENCHER-FC methods agreed well and had similar precision in F-statistics. Although the Gibbs free energy change (ΔG°) of the oxidation of HA dihydroxy phenols with the test reagents were negative, the ΔG° was positive only for the reaction of CUPRAC reagent with isolated monohydric phenols, showing CUPRAC selectivity toward polyphenolic antioxidants. This is the first work on the antioxidant capacity measurement of HA having a sparingly soluble matrix where enhanced solubilization of bound phenolics is achieved with coupled oxidation by TAC reagents. PMID:27130098

  3. Hepatic Fatty Acid Oxidation Restrains Systemic Catabolism during Starvation.

    PubMed

    Lee, Jieun; Choi, Joseph; Scafidi, Susanna; Wolfgang, Michael J

    2016-06-28

    The liver is critical for maintaining systemic energy balance during starvation. To understand the role of hepatic fatty acid β-oxidation on this process, we generated mice with a liver-specific knockout of carnitine palmitoyltransferase 2 (Cpt2(L-/-)), an obligate step in mitochondrial long-chain fatty acid β-oxidation. Fasting induced hepatic steatosis and serum dyslipidemia with an absence of circulating ketones, while blood glucose remained normal. Systemic energy homeostasis was largely maintained in fasting Cpt2(L-/-) mice by adaptations in hepatic and systemic oxidative gene expression mediated in part by Pparα target genes including procatabolic hepatokines Fgf21, Gdf15, and Igfbp1. Feeding a ketogenic diet to Cpt2(L-/-) mice resulted in severe hepatomegaly, liver damage, and death with a complete absence of adipose triglyceride stores. These data show that hepatic fatty acid oxidation is not required for survival during acute food deprivation but essential for constraining adipocyte lipolysis and regulating systemic catabolism when glucose is limiting. PMID:27320917

  4. Enhanced exercise and regenerative capacity in a mouse model that violates size constraints of oxidative muscle fibres

    PubMed Central

    Omairi, Saleh; Matsakas, Antonios; Degens, Hans; Kretz, Oliver; Hansson, Kenth-Arne; Solbrå, Andreas Våvang; Bruusgaard, Jo C; Joch, Barbara; Sartori, Roberta; Giallourou, Natasa; Mitchell, Robert; Collins-Hooper, Henry; Foster, Keith; Pasternack, Arja; Ritvos, Olli; Sandri, Marco; Narkar, Vihang; Swann, Jonathan R; Huber, Tobias B; Patel, Ketan

    2016-01-01

    A central tenet of skeletal muscle biology is the existence of an inverse relationship between the oxidative fibre capacity and its size. However, robustness of this relationship is unknown. We show that superimposition of Estrogen-related receptor gamma (Errγ) on the myostatin (Mtn) mouse null background (Mtn-/-/ErrγTg/+) results in hypertrophic muscle with a high oxidative capacity thus violating the inverse relationship between fibre size and oxidative capacity. We also examined the canonical view that oxidative muscle phenotype positively correlate with Satellite cell number, the resident stem cells of skeletal muscle. Surprisingly, hypertrophic fibres from Mtn-/-/ErrγTg/+ mouse showed satellite cell deficit which unexpectedly did not affect muscle regeneration. These observations 1) challenge the concept of a constraint between fibre size and oxidative capacity and 2) indicate the important role of the microcirculation in the regenerative capacity of a muscle even when satellite cell numbers are reduced. DOI: http://dx.doi.org/10.7554/eLife.16940.001 PMID:27494364

  5. Antioxidant capacities of flavones and benefits in oxidative-stress related diseases.

    PubMed

    Catarino, Marcelo D; Alves-Silva, Jorge M; Pereira, Olivia R; Cardoso, Susana M

    2015-01-01

    Flavonoids, a group of secondary metabolites widely distributed in the plant kingdom, have been acknowledged for their interesting medicinal properties. Among them, natural flavones, as well as some of their synthetic derivatives, have been shown to exhibit several biological activities, including antioxidant, anti-inflammatory, antitumor, anti-allergic, neuroprotective, cardioprotective and antimicrobial. The antioxidant properties of flavones allow them to demonstrate potential application as preventive and attenuating agents in oxidative stress, i.e., a biological condition that is closely associated to aging process and several diseases. Some flavones interfere in distinct oxidative-stress related events by directly reducing the levels of intracellular free radicals (hydroxyl, superoxide and nitric oxide) and/or of reactive species (e.g. hydrogen peroxide, peroxynitrite and hypochlorous acid) thus preventing their amplification and the consequent damage of other biomolecules such as lipids, proteins and DNA. Flavones can also hinder the activity of central free radical-producing enzymes, such as xanthine oxidase and nicotinamide adenine dinucleotide phosphate oxidase (NADPH-oxidase) or inducible nitric oxide synthase (iNOS) and can even modulate the intracellular levels of pro-oxidant and/or antioxidant enzymes. The evaluation of flavones antioxidant ability has been extensively determined in chemical or biological in vitro models, but in vivo therapy with individual flavones or with flavones-enriched extracts has also been reported. The present manuscript revises relevant studies focusing the preventive effects of flavones on stress-related diseases, namely the neurological and cardiovascular diseases, and diabetes and its associated complications. PMID:25547095

  6. Holocene Concentrations of Methane in the Atmosphere are in Part Proportional to Concentrations of Sulfur Dioxide and Inversely Proportional to the Oxidizing Capacity of the Atmosphere

    NASA Astrophysics Data System (ADS)

    Ward, P. L.

    2008-12-01

    The atmosphere cleans itself by oxidizing pollutants. The primary oxidant is the hydroxyl radical (OH) formed by photodissociation of ozone in the near ultra-violet. Ozone and OH are in limited supply. Sulfur dioxide (SO2) absorbs near ultraviolet light limiting production of OH and reacts immediately with any available OH, forming sulfuric acid. Methane reacts more slowly with OH and will typically not be oxidized until there is little SO2. Thus a high concentration of methane indicates low oxidizing capacity. The rate at which SO2 is injected into the atmosphere controls oxidizing capacity and climate change in four ways: 1. Moderate rate: Large volcanic eruptions (VEI >=6) lower global temperatures for a few years when they are separated by years to decades so the oxidizing capacity of the atmosphere can fully recover. In 1991, Pinatubo volcano in the Philippines erupted 20 Mt SO2 and 491 Mt H2O, the largest volcanic eruption since 1912. The SO2 was oxidized primarily by OH to form a 99% pure aerosol of sulfuric acid and water at an elevation of 20-23 km. This aerosol reflected sunlight, lowering the world's temperature on average 0.4°C for three years. Ozone levels were reduced by 10%. Methane increased by 15 ppb for a year. The e-folding time for SO2 was 35 days. 2. High rate: When large eruptions occur once to several times per year, there is insufficient oxidizing capacity leading to increases in methane and other greenhouse gases and global warming. There were 15 times in the Holocene when large volcanoes erupted on average at least every year for 7 to 21 years. Man is now putting as much SO2 from burning fossil fuels into the atmosphere every year as one large volcano, causing current global warming. The two previous times were from 818-838 AD, the onset of the Medieval Warming Period, and from 180-143 BC, the onset of the Roman Warm Period. 3. Low rate: When there are no large eruptions for decades, the oxidizing capacity can catch up, cleaning the

  7. Detection and characterization of oxidizing acids in the Atacama Desert using the Mars Oxidation Instrument

    NASA Astrophysics Data System (ADS)

    Quinn, R. C.; Zent, A. P.; Grunthaner, F. J.; Ehrenfreund, P.; Taylor, C. L.; Garry, J. R. C.

    2005-11-01

    We have performed field experiments to further develop and validate the Mars Oxidation Instrument (MOI) as well as measurement strategies for the in situ characterization of oxidation mechanisms, kinetics, and carbon cycling on Mars. Using the Atacama Desert as a test site for the current dry conditions on Mars, we characterized the chemical reactivity of surface and near-surface atmosphere in the dry core of the Atacama. MOI is a chemiresistor-based sensor array that measures the reaction rates of chemical films that are sensitive to particular types of oxidants or that mimic chemical characteristics of pre-biotic and biotic materials. With these sensors, the chemical reactivity of a planetary environment is characterized by monitoring the resistance of the film as a function of time. Our instrumental approach correlates reaction rates with dust abundance, UV flux, humidity, and temperature, allowing discrimination between competing hypotheses of oxidant formation and organic decomposition. The sensor responses in the Atacama are consistent with an oxidative attack by strong acids triggered by dust accumulation, followed by transient wetting due to an increase in relative humidity during the night. We conclude that in the Atacama Desert, and perhaps on Mars, low pH resulting from acid accumulation, combined with limited water availability and high oxidation potential, can result in oxidizing acid reactions on dust and soil surfaces during low-moisture transient wetting events (i.e. thin films of water). These soil acids are expected to play a significant role in the oxidizing nature of the soils, the formation of mineral surface coatings, and the chemical modification of organics in the surface material.

  8. Oxidation of hypotaurine and cysteine sulphinic acid by peroxynitrite

    PubMed Central

    2005-01-01

    Peroxynitrite mediates the oxidation of the sulphinic group of both HTAU (hypotaurine) and CSA (cysteine sulphinic acid), producing the respective sulphonates, TAU (taurine) and CA (cysteic acid). The reaction is associated with extensive oxygen uptake, suggesting that HTAU and CSA are oxidized by the one-electron transfer mechanism to sulphonyl radicals, which may initiate an oxygen-dependent radical chain reaction with the sulphonates as final products. Besides the one-electron mechanism, HTAU and CSA can be oxidized by the two-electron pathway, leading directly to sulphonate formation without oxygen consumption. The apparent second-order rate constants for the direct reaction of peroxynitrite with HTAU and CSA at pH 7.4 and 25 °C are 77.4±5 and 76.4±9 M−1·s−1 respectively. For both sulphinates, the apparent second-order rate constants increase sharply with decrease in pH, and the sigmoidal curves obtained are consistent with peroxynitrous acid as the species responsible for sulphinate oxidation. The kinetic data, together with changes in oxygen uptake, sulphinate depletion, sulphonate production, and product distribution of nitrite and nitrate, suggest that oxidation of sulphinates by peroxynitrite may take place by the two reaction pathways whose relative importance depends on reagent concentrations and pH value. In the presence of bicarbonate, the direct reaction of sulphinates with peroxynitrite is inhibited and the oxidative reaction probably involves only the radicals •NO2 and CO3•−, generated by decomposition of the peroxynitrite-CO2 adduct. PMID:15740460

  9. Influence of transition metal electronegativity on the oxygen storage capacity of perovskite oxides.

    PubMed

    Liu, Lu; Taylor, Daniel D; Rodriguez, Efrain E; Zachariah, Michael R

    2016-08-16

    The selection of highly efficient oxygen carriers (OCs) is a key step necessary for the practical development of chemical looping combustion (CLC). In this study, a series of ABO3 perovskites, where A = La, Ba, Sr, Ca and B = Cr, Mn, Fe, Co, Ni, Cu, are synthesized and tested in a fixed bed reactor for reactivity and stability as OCs with CH4 as the fuel. We find that the electronegativity of the transition metal on the B-site (λB), is a convenient descriptor for oxygen storage capacity (OSC) of our perovskite samples. By plotting OSC for total methane oxidation against λB, we observe an inverted volcano plot relationship. These results could provide useful guidelines for perovskite OC design and their other energy related applications. PMID:27478888

  10. Suppression of irreversible capacity loss in Li-rich layered oxide by fluorine doping

    NASA Astrophysics Data System (ADS)

    Song, Jay Hyok; Kapylou, Andrei; Choi, Hee Sung; Yu, Byong Yong; Matulevich, Evegeniya; Kang, Sun Ho

    2016-05-01

    Li[Li1/6Ni1/6Co1/6Mn1/2]O2-xFx (x = 0.00 to 0.07) materials were synthesized with low temperature heat treatment (700 °C) and their electrochemical performances were evaluated. With the addition of fluorine, the reversible capacity significantly increased as the irreversibility was suppressed during the first cycle. The reduction of irreversibility was mainly attributed to the enhanced first cycle efficiency of Li2MnO3-like component after the fluorine addition. By combining results of the X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), In-situ X-ray absorption spectroscopy (XAS) analyses, and first principle calculations, it was proposed that the presence of fluorine facilitated the reduction of cobalt and manganese ions in Li-rich layered oxide, and that the reduced transition metal (TM) ions suppressed structural changes.

  11. Surface acidity of silica-titania mixed oxides

    SciTech Connect

    Odenbrand, C.U.I.; Brandin, J.G.M. ); Busca, G. )

    1992-06-01

    A study of the acidity of coprecipitated SiO[sub 2]-TiO[sub 2] oxides is presented. The amount of acidity has been determined by ammonia adsorption at 150 C. The acidity was also characterized by TPD of adsorbed ammonia and by infrared spectroscopy of various adsorbed probes, such as pivalonitrile, pyridine, ammonia, and n-butylamine. From the quantitative measurements of adsorption of ammonia and from TPD it was concluded that the SiO[sub 2]-TiO[sub 2] mixture can be regarded as a mechanical mixture of silica and titania. However, the IR investigation showed that Ti enters in small amounts into the silica framework. This results in formation of very strong Lewis acid sites, caused by incomplete tetrahedral coordination of Ti[sup 4[minus

  12. Influence of exercise training on the oxidative capacity of rat abdominal muscles

    NASA Technical Reports Server (NTRS)

    Uribe, J. M.; Stump, C. S.; Tipton, C. M.; Fregosi, R. F.

    1992-01-01

    Our purpose was to determine if endurance exercise training would increase the oxidative capacity of the abdominal expiratory muscles of the rat. Accordingly, 9 male rats were subjected to an endurance training protocol (1 h/day, 6 days/week, 9 weeks) and 9 litter-mates served as controls. Citrate synthase (CS) activity was used as an index of oxidative capacity, and was determined in the following muscles: soleus, plantaris, costal diaphragm, crural diaphragm, and in all four abdominal muscles: rectus abdominis, transversus abdominis, external oblique, and internal oblique. Compared to their non-trained litter-mates, the trained rats had higher peak whole body oxygen consumption rates (+ 16%) and CS activities in plantaris (+34%) and soleus (+36%) muscles. Thus, the training program caused substantial systemic and locomotor muscle adaptations. The CS activity of costal diaphragm was 20% greater in the trained animals, but no difference was observed in crural diaphragm. The CS activity in the abdominal muscles was less than one-half of that in locomotor and diaphragm muscles, and there were no significant changes with training except in the rectus abdominis where a 26% increase was observed. The increase in rectus abdominis CS activity may reflect its role in postural support and/or locomotion, as none of the primary expiratory pumping muscles adapted to the training protocol. The relatively low levels of CS activity in the abdominal muscles suggests that they are not recruited frequently at rest, and the lack of an increase with training indicates that these muscles do not contribute significantly to the increased ventilatory activity accompanying exercise in the rat.

  13. Nitroaromatic amino acids as inhibitors of neuronal nitric oxide synthase.

    PubMed

    Cowart, M; Kowaluk, E A; Daanen, J F; Kohlhaas, K L; Alexander, K M; Wagenaar, F L; Kerwin, J F

    1998-07-01

    Nitric oxide (NO.) is an important biomodulator of many physiological processes. The inhibition of inappropriate production of NO. by the isoforms of nitric oxide synthase (NOS) has been proposed as a therapeutic approach for the treatment of stroke, inflammation, and other processes. In this study, certain 2-nitroaryl-substituted amino acid analogues were discovered to inhibit NOS. Analogues bearing a 5-methyl substituent on the aromatic ring demonstrated maximal inhibitory potency. For two selected inhibitors, investigation of the kinetics of the enzyme showed the inhibition to be competitive with l-arginine. Additionally, functional NOS inhibition in tissue preparations was demonstrated. PMID:9651169

  14. Increased muscle fatty acid oxidation in dairy cows with intensive body fat mobilization during early lactation.

    PubMed

    Schäff, C; Börner, S; Hacke, S; Kautzsch, U; Sauerwein, H; Spachmann, S K; Schweigel-Röntgen, M; Hammon, H M; Kuhla, B

    2013-10-01

    The beginning of lactation requires huge metabolic adaptations to meet increased energy demands for milk production of dairy cows. One of the adaptations is the mobilization of body reserves mainly from adipose tissue as reflected by increased plasma nonesterified fatty acid (NEFA) concentrations. The capacity of the liver for complete oxidation of NEFA is limited, leading to an increased formation of ketone bodies, reesterification, and accumulation of triglycerides in the liver. As the skeletal muscle also may oxidize fatty acids, it may help to decrease the fatty acid load on the liver. To test this hypothesis, 19 German Holstein cows were weekly blood sampled from 7 wk before until 5 wk after parturition to analyze plasma NEFA concentrations. Liver biopsies were obtained at d 3, 18, and 30 after parturition and, based on the mean liver fat content, cows were grouped to the 10 highest (HI) and 9 lowest (LO). In addition, muscle biopsies were obtained at d -17, 3, and 30 relative to parturition and used to quantify mRNA abundance of genes involved in fatty acid degradation. Plasma NEFA concentrations peaked after parturition and were 1.5-fold higher in HI than LO cows. Muscle carnitine palmitoyltransferase 1α and β mRNA was upregulated in early lactation. The mRNA abundance of muscle peroxisome proliferator-activated receptor γ (PPARG) increased in early lactation and was higher in HI than in LO cows, whereas the abundance of PPARA continuously decreased after parturition. The mRNA abundance of muscle PPARD, uncoupling protein 3, and the β-oxidative enzymes 3-hydroxyacyl-coenzyme A (CoA) dehydrogenase, very long-chain acyl-CoA dehydrogenase, and 3-ketoacyl-CoA was greatest at d 3 after parturition, whereas the abundance of PPARγ coactivator 1α decreased after parturition. Our results indicate that around parturition, oxidation of fatty acids in skeletal muscle is highly activated, which may contribute to diminish the fatty acid load on the liver. The

  15. Synthesis of docosahexaenoic acid from eicosapentaenoic acid in retina neurons protects photoreceptors from oxidative stress.

    PubMed

    Simón, María Victoria; Agnolazza, Daniela L; German, Olga Lorena; Garelli, Andrés; Politi, Luis E; Agbaga, Martin-Paul; Anderson, Robert E; Rotstein, Nora P

    2016-03-01

    Oxidative stress is involved in activating photoreceptor death in several retinal degenerations. Docosahexaenoic acid (DHA), the major polyunsaturated fatty acid in the retina, protects cultured retina photoreceptors from apoptosis induced by oxidative stress and promotes photoreceptor differentiation. Here, we investigated whether eicosapentaenoic acid (EPA), a metabolic precursor to DHA, had similar effects and whether retinal neurons could metabolize EPA to DHA. Adding EPA to rat retina neuronal cultures increased opsin expression and protected photoreceptors from apoptosis induced by the oxidants paraquat and hydrogen peroxide (H2 O2 ). Palmitic, oleic, and arachidonic acids had no protective effect, showing the specificity for DHA. We found that EPA supplementation significantly increased DHA percentage in retinal neurons, but not EPA percentage. Photoreceptors and glial cells expressed Δ6 desaturase (FADS2), which introduces the last double bond in DHA biosynthetic pathway. Pre-treatment of neuronal cultures with CP-24879 hydrochloride, a Δ5/Δ6 desaturase inhibitor, prevented EPA-induced increase in DHA percentage and completely blocked EPA protection and its effect on photoreceptor differentiation. These results suggest that EPA promoted photoreceptor differentiation and rescued photoreceptors from oxidative stress-induced apoptosis through its elongation and desaturation to DHA. Our data show, for the first time, that isolated retinal neurons can synthesize DHA in culture. Docosahexaenoic acid (DHA), the major polyunsaturated fatty acid in retina photoreceptors, and its precursor, eicosapentaenoic acid (EPA) have multiple beneficial effects. Here, we show that retina neurons in vitro express the desaturase FADS2 and can synthesize DHA from EPA. Moreover, addition of EPA to these cultures protects photoreceptors from oxidative stress and promotes their differentiation through its metabolization to DHA. PMID:26662863

  16. Oxidative removal of bisphenol A using zero valent aluminum-acid system.

    PubMed

    Liu, Wanpeng; Zhang, Honghua; Cao, Beipei; Lin, Kunde; Gan, Jay

    2011-02-01

    Bisphenol A (BPA), a controversial endocrine disruptor, is ubiquitous in the aquatic environment. In this study, the oxidative degradation of BPA and its mechanism using zero valent aluminum (ZVAl)-acid system under air-equilibrated conditions was investigated. Under pH <3.5 acidic conditions, ZVAl demonstrated an excellent capacity to remove BPA. More than 75% of BPA was eliminated within 12 h in pH 1.5 reaction solutions initially containing 4.0 g/L aluminum and 2.0 mg/L BPA at 25 ± 1 °C. The removal of BPA was further accelerated with increasing aluminum loadings. Higher temperature and lower initial pH also facilitated BPA removal. The addition of Fe(2+) into the ZVAl-acid system significantly accelerated the reaction likely due to the enhancing transformation of H(2)O(2) to HO via Fenton reaction. Furthermore, the primary products or intermediates including monohydroxylated BPA, hydroquinone, 2-(4-hydroxyphenyl)propane and 4-isopropenylphenol, were identified and a possible reaction scheme was proposed. The remarkable capacity of the ZVAl-acid system in removing BPA displays its potential application in the treatment of organic compound-contaminated water. PMID:21185583

  17. Adsorption kinetics and thermodynamics of acid Bordeaux B from aqueous solution by graphene oxide/PAMAMs.

    PubMed

    Zhang, Fan; He, Shengfu; Zhang, Chen; Peng, Zhiyuan

    2015-01-01

    Graphene oxide/polyamidoamines dendrimers (GO/PAMAMs) composites were synthesized via modifying GO with 2.0 G PAMAM. The adsorption behavior of the GO/PAMAMs for acid Bordeaux B (ABB) was studied and the effects of media pH, adsorption time and initial ABB concentration on adsorption capacity of the adsorbent were investigated. The optimum pH value of the adsorption of ABB onto GO/PAMAMs was 2.5. The maximum adsorption capacity increased from 325.78 to 520.83 mg/g with the increase in temperature from 298 to 328 K. The equilibrium data followed the Langmuir isotherm model better than the Freundlich model. The kinetic study illustrated that the adsorption of ABB onto GO/PAMAMs fit the pseudo-second-order model. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process. PMID:26398038

  18. Cytoprotective effect of preparations from various parts of Punica granatum L. fruits in oxidatively injured mammalian cells in comparison with their antioxidant capacity in cell free systems.

    PubMed

    Sestili, Piero; Martinelli, Chiara; Ricci, Donata; Fraternale, Daniele; Bucchini, Anahi; Giamperi, Laura; Curcio, Rosanna; Piccoli, Giovanni; Stocchi, Vilberto

    2007-07-01

    Pomegranate (Punica granatum L.) juice (PJ) is being increasingly proposed as a nutritional supplement to prevent atherosclerosis in humans. This therapeutically valuable potential has been attributed to PJ antioxidant capacity which has been mostly tested by means of cell-free assays: indeed, to the best of our knowledge, no study has focused on the direct antioxidant capacity of PJ in cultured cells. Here, the antioxidant capacity in cell free-systems of preparations from various parts of pomegranate has been compared with their cytoprotective -bona fide antioxidant--activity in cultured human cells (U937 promonocytes and HUVEC endothelial cells) exposed to an array of oxidizing agents. Pomegranate derivatives were PJ, arils only juice (AJ) and aqueous rinds extract (RE). In cell-free assays--1,1-diphenyl-2-picrylhydrazyl (DPPH), chemiluminescence luminol/xanthine/xanthine oxidase and lipoxygenase assays--all the preparations displayed good antioxidant capacity, the relative potency order being RE>PJ>AJ. On the contrary, only RE was capable of preventing the deleterious effects--cytotoxicity, DNA damage and depletion of non-protein sulphydrils (NPSH) pool--caused by treatment of cells with H(2)O(2), tert-butylhydroperoxide (tB-OOH) or oxidized lipoproteins (Ox-LDL) via a mechanism which is likely to involve both direct scavenging of radical species and iron chelation. Surprisingly, AJ and PJ slightly sensitized cells to the cytotoxic effects of the three agents. Then it would appear that AJ, the major and tasty part of PJ, does not contain ellagic acid and punicalagin (i.e. the polyphenols highly represented in RE which are reputed to be responsible for the antioxidant capacity) in amounts sufficient to exert cytoprotection in oxidatively injured, living cells. Based on these results, the development and evaluation of rinds-only based derivatives for antiatherogenic preventive purposes in humans should be encouraged. PMID:17376699

  19. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells

    PubMed Central

    Song, Eun Ah; Kim, Hyeyoung

    2016-01-01

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells’ molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies. PMID:27527148

  20. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells.

    PubMed

    Song, Eun Ah; Kim, Hyeyoung

    2016-01-01

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells' molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies. PMID:27527148

  1. Leady oxide for lead/acid battery positive plates: scope for improvement?

    NASA Astrophysics Data System (ADS)

    Mayer, M. G.; Rand, D. A. J.

    Among the many factors that determine and influence the performance of lead/acid batteries, one of the most important, and as yet not fully developed, is how to make the positive active mass more electrochemically reactive. The inherent characteristics of this active mass are the cumulative result of the four precursor stages of its production, namely, the leady oxide, paste mixing, curing and formation procedures. There is evidence to suggest that the method of pasting itself is also influential. Many recent studies have reported progress on techniques to increase active-material utilization, to improve plate conditioning, and to solve the vexagious problem of premature capacity loss. The purpose of this discussion is to focus attention on the role and the importance of leady oxide on battery design and performance. At present, the battery industry makes leady oxide by either the ball-mill or the Barton-pot process. It is difficult to conclude which of the two methods gives the best leady oxide. Each type of leady oxide has its champions but, in general, ball-mill and Barton-pot product both make effective automotive batteries. For deep-cycle batteries, however, many battery companies (especially in Europe and Japan) prefer ball-mill oxide; in North America, the Barton-pot variety is favoured. This investigation examines the present procedures for making leady oxide, the desirable properties of leady oxide, and the influence of the oxide on battery performance. Analysis shows that there is scope for the production of improved leady oxide—by using existing production techniques and/or by the development of new processing technology.

  2. Origin of voltage decay in high-capacity layered oxide electrodes

    NASA Astrophysics Data System (ADS)

    Sathiya, M.; Abakumov, A. M.; Foix, D.; Rousse, G.; Ramesha, K.; Saubanère, M.; Doublet, M. L.; Vezin, H.; Laisa, C. P.; Prakash, A. S.; Gonbeau, D.; Vantendeloo, G.; Tarascon, J.-M.

    2015-02-01

    Although Li-rich layered oxides (Li1+xNiyCozMn1-x-y-zO2 > 250 mAh g-1) are attractive electrode materials providing energy densities more than 15% higher than today’s commercial Li-ion cells, they suffer from voltage decay on cycling. To elucidate the origin of this phenomenon, we employ chemical substitution in structurally related Li2RuO3 compounds. Li-rich layered Li2Ru1-yTiyO3 phases with capacities of ~240 mAh g-1 exhibit the characteristic voltage decay on cycling. A combination of transmission electron microscopy and X-ray photoelectron spectroscopy studies reveals that the migration of cations between metal layers and Li layers is an intrinsic feature of the charge-discharge process that increases the trapping of metal ions in interstitial tetrahedral sites. A correlation between these trapped ions and the voltage decay is established by expanding the study to both Li2Ru1-ySnyO3 and Li2RuO3; the slowest decay occurs for the cations with the largest ionic radii. This effect is robust, and the finding provides insights into new chemistry to be explored for developing high-capacity layered electrodes that evade voltage decay.

  3. An unexpected large capacity of ultrafine manganese oxide as a sodium-ion battery anode.

    PubMed

    Weng, Yu-Ting; Huang, Tzu-Yang; Lim, Chek-Hai; Shao, Pei-Sian; Hy, Sunny; Kuo, Chao-Yen; Cheng, Ju-Hsiang; Hwang, Bing-Joe; Lee, Jyh-Fu; Wu, Nae-Lih

    2015-12-21

    MnO2 is shown for the first time to be electrochemically active as a conversion anode for Na-ion batteries (NIBs). Space-confined ultrafine (UF)-MnO2, with an average crystal size of 4 nm, synthesized using a porous silicon dioxide templated hydrothermal process exhibits a high reversible sodiation capacity of 567 mA h g(-1), in contrast to the negligible activity shown by the aggregates of larger (14 nm) MnO2 nanocrystallites. The remarkably enhanced sodiation activity of the UF-MnO2 is attributable to its greatly reduced crystal size, which facilitates diffusion of Na ions, along with high surface energy arising from extensive heterogeneous interfacial bonding with the SiO2 surrounding. The UF-MnO2 anode exhibits an exceptional rate and cycle performance, exhibiting >70% capacity retention after 500 cycles. In operando synchrotron X-ray absorption near-edge structural analysis reveals combined charge-storage mechanisms involving conversion reaction between Mn(III) and Mn(II) oxides, Mn(III)-O1.5 + Na(+) + e(-)- ↔ 1/2Na2O + Mn(II)-O, and non-Mn-centered redox reactions. The finding suggests a new strategy for "activating" the potential electrochemical electrode materials that appear inactive in the bulk form. PMID:26567463

  4. Interactions of humic acid with nanosized inorganic oxides.

    PubMed

    Yang, Kun; Lin, Daohui; Xing, Baoshan

    2009-04-01

    Adsorption of natural organic matter (NOM) on nanoparticles (NPs) is important for evaluating their transport, transfer, and fate in the environment, which will also affect sorption of hydrophobic organic compounds (HOCs) by NPs and thereby potentially alter the toxicity of NPs and the fate, transport, and bioavailability of HOCs in the environment. Therefore, the adsorption behavior of humic acids (HA) by four types of nano-oxides (i.e., TiO2, SiO2, Al2O3, and ZnO) was examined in this study to explore their interaction mechanisms using techniques including Fourier transform infrared (FTIR) spectroscopy and elemental, zeta potential, and surface area analyses. Adsorption of HA was observed on nanosized TiO2, Al2O3, and ZnO but not on nano-SiO2. Furthermore, HA adsorption was pH-dependent. HA adsorption by nano-oxides was mainly induced by electrostatic attraction and ligand exchange between HA and nano-oxide surfaces. Surface hydrophilicity and negative charges of nano-oxides affected their adsorption of HA. However, the maxima of HA adsorption on nano-oxides were limited by the surface area of nano-oxides. HA phenolic OH and COOH groups were responsible for its ligand exchange with nano-TiO2 and nano-ZnO, respectively, while either HA COOH or HA phenolic/aliphatic OH was responsible for its ligand exchange with nano-Al2O3. HA adsorption decreased the micropore surface area of nano-oxides but not the external surface area because of the micropore blockage. HA adsorption also decreased the zeta potential of nano-oxides, indicating that HA-coated nano-oxides could be more easily dispersed and suspended and more stable in solution than uncoated ones because of their enhanced electrostatic repulsion. PMID:19708146

  5. Hepatic alpha-oxidation of phytanic acid. A revised pathway.

    PubMed

    Van Veldhoven, P P; Mannaerts, G P; Casteels, M; Croes, K

    1999-01-01

    Synthetic 3-methyl-branched chain fatty acids were used to decipher the breakdown of phytanic acid. Based on results obtained in intact or permeabilized rat hepatocytes, rat liver homogenates or subcellular fractions, a revised alpha-oxidation pathway is proposed which appears to be functioning in man as well. In a first step, the 3-methyl-branched chain fatty acid is activated by an acyl-CoA synthetase. This reaction requires CoA, ATP and Mg2+. Subsequently, the acyl-CoA ester is hydroxylated at position 2 by a peroxisomal dioxygenase. This step is dependent on alpha-oxoglutarate, ascorbate (or glutathione), Fe2+ and O2. The 2-hydroxy-3-methylacyl-CoA intermediate is cleaved by a peroxisomal lyase to formyl-CoA and a 2-methyl-branched fatty aldehyde. Formyl-CoA is (partly enzymically) hydrolyzed to formate, which is then converted, most likely in the cytosol, to CO2. In the presence of NAD+, the aldehyde is dehydrogenated to a 2-methyl-branched fatty acid, presumably by a peroxisomal aldehyde dehydrogenase. This acid can--after activation--be degraded via a D-specific peroxisomal beta-oxidation system. PMID:10709654

  6. Stemflow Acid Neutralization Capacity in a Broadleaved Deciduous Forest: The Role of Edge Effects

    NASA Astrophysics Data System (ADS)

    Levia, D. F., Jr.; Shiklomanov, A.

    2014-12-01

    The fragmentation of forests is occurring at an accelerated rate in parts of the United States. Forest fragmentation creates edge habitat that affects the biogeochemistry of forests. Atmospheric deposition is known to increase at the forest edge in comparison to the forest interior. Past research has demonstrated the critical role of edge effects on throughfall chemistry but no known work has examined the relationship between stemflow chemistry and edge effects. To fill this data gap, we quantified the stemflow acid neutralization capacity (ANC) of nineteen Liriodendron tulipifera L. (yellow poplar) trees between forest edge and interior locations in the Piedmont of the mid-Atlantic USA. ANC was measured directly by potentiometric titration. Both stemflow pH and ANC were higher for L. tulipifera trees on the forest edge as opposed to those in interior locations (p < 0.01), although marked variability was observed among individual trees. It is critical to note that the ANC of stemflow of edge trees is almost certainly contextual, depending on geographic locality. This is to say that stemflow from edge trees may neutralize acid inputs in some locations (as in our case) but lead to enhanced acidification of aqueous inputs to forest soils in other locales where the dry deposition of acid anions is high. The experimental results have ramifications for forest management schema seeking to increase or decrease the extent of edge habitat in forest fragments.

  7. Enhanced formic acid oxidation on Cu-Pd nanoparticles

    NASA Astrophysics Data System (ADS)

    Dai, Lin; Zou, Shouzhong

    Developing catalysts with high activity and high resistance to surface poisoning remains a challenge in direct formic acid fuel cell research. In this work, copper-palladium nanoparticles were formed through a galvanic replacement process. After electrochemically selective dissolution of surface Cu, Pd-enriched Cu-Pd nanoparticles were formed. These particles exhibit much higher formic acid oxidation activities than that on pure Pd nanoparticles, and they are much more resistant to the surface poisoning. Possible mechanisms of catalytic activity enhancement are briefly discussed.

  8. Roles of urea production, ammonium excretion, and amino acid oxidation in acid-base balance.

    PubMed

    Mackenzie, W

    1986-02-01

    Atkinson and colleagues recently proposed several concepts that contrast with traditional views: first, that acid-base balance is regulated chiefly by the reactions leading to urea production in the liver; second, that ammonium excretion by the kidney plays no role in acid-base homeostasis; and third, that ammonium does not stimulate ureagenesis (except indirectly). To examine these concepts, plasma ions other than bicarbonate are categorized as 1) fixed cations (Na+, K+, Ca2+, and Mg2+, symbolized M+) and anions (Cl-), 2) buffer anions (A-), 3) other anions (X-), and 4) ammonium plus charged amino groups (N+). Since electroneutrality dictates that M+ + N+ = Cl- + HCO3- + A- + X-, it follows that delta HCO3- = delta(M+ - Cl-) - delta A- - delta X- + delta N+. Therefore acid-base disturbances (changes in HCO3-) can be categorized as to how they affect bodily content and hence plasma concentration of each of these four types of ions. The stoichiometry of ureagenesis, glutamine hydrolysis, ammonium and titratable acid excretion, oxidation of neutral, acidic, and basic amino acids, and oxidation of methionine, phosphoserine, and protein are examined to see how they alter these quantities. It is concluded that 1) although ureagenesis is pH dependent and also counteracts a tendency of amino acid oxidation to cause alkalosis, this tendency is inherently limited by the hyperammonemia (delta N+) that necessarily accompanies it, 2) ammonium excretion is equivalent to hydrogen excretion in its effects on acid-base balance if, and only if, it occurs in exchange for sodium or is accompanied by chloride excretion and only when the glutamate generated by glutamine hydrolysis is oxidized.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3511732

  9. Biological reactivity and biomarkers of the neutrophil oxidant, hypochlorous acid.

    PubMed

    Winterbourn, Christine C

    2002-12-27

    Free radicals or reactive oxygen species are thought to contribute to the pathology of many diseases. These include inflammatory conditions, where neutrophils accumulate in large numbers and are stimulated to produce superoxide and other reactive oxidants. Hypochlorous acid (HOCl), produced by myeloperoxidase-catalysed oxidation of chloride by hydrogen peroxide, is the major strong oxidant generated by these cells. Neutrophil-mediated injury may also be important in toxicology when an initial insult is followed by an inflammatory response. It is important to characterize the inflammatory component of such injury and the extent to which it involves reactive oxidants. On the one hand, this requires an understanding of how neutrophil oxidants react with cells and tissue constituents. On the other, specific biomarkers are needed so that oxidative damage can be quantified in clinical material and related to disease severity. This presentation considers biologically relevant reactions of HOCl and the biomarker assays that can be applied to probing the pathological role of myeloperoxidase and its products. PMID:12505315

  10. Oxide for valve-regulated lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Lam, L. T.; Lim, O. V.; Haigh, N. P.; Rand, D. A. J.; Manders, J. E.; Rice, D. M.

    In order to meet the increasing demand for valve-regulated lead-acid (VRLA) batteries, a new soft lead has been produced by Pasminco Metals. In this material, bismuth is increased to a level that produces a significant improvement in battery cycle life. By contrast, other common impurities, such as arsenic, cobalt, chromium, nickel, antimony and tellurium, that are known to be harmful to VRLA batteries are controlled to very low levels. A bismuth (Bi)-bearing oxide has been manufactured (Barton-pot method) from this soft lead and is characterized in terms of phase composition, particle size distribution, BET surface area, and reactivity. An investigation is also made of the rates of oxygen and hydrogen evolution on pasted electrodes prepared from the Bi-bearing oxide. For comparison, the characteristics and performance of a Bi-free (Barton-pot) oxide, which is manufactured in the USA, are also examined. Increasing the level of bismuth and lowering those of the other impurities in soft lead produces no unusual changes in either the physical or the chemical properties of the resulting Bi-bearing oxide compared with Bi-free oxide. This is very important because there is no need for battery manufacturers to change their paste formulae and paste-mixing procedures on switching to the new Bi-bearing oxide. There is little difference in the rates of oxygen and hydrogen evolution on pasted electrodes prepared from Bi-bearing or Bi-free oxides. On the other hand, these rates increase on the former electrodes when the levels of all the other impurities are made to exceed (by deliberately adding the impurities as oxide powders) the corresponding, specified values for the Bi-bearing oxide. The latter behaviour is particularly noticeable for hydrogen evolution, which is enhanced even further when a negative electrode prepared from Bi-bearing oxide is contaminated through the deposition of impurities added to the sulfuric acid solution. The effects of impurities in the positive

  11. Atmospheric Hydroperoxides in West Antarctica: Links to Stratospheric Ozone and Atmospheric Oxidation Capacity

    NASA Technical Reports Server (NTRS)

    Frey, Markus M.; Stewart, Richard W.; McConnell, Joseph R.; Bales, Roger C.

    2005-01-01

    The troposphere above the West Antarctic Ice Sheet (WAIS) was sampled for hydroperoxides at 21 locations during 2-month-long summer traverses from 2000 to 2002, as part of US ITASE (International Transantarctic Scientific Expedition). First time quantitative measurements using an HPLC method showed that methylhydroperoxide (MHP) is the only important organic hydroperoxide occurring in the Antarctic troposphere, and that it is found at levels ten times those previously predicted by photochemical models. During three field seasons, means and standard deviations for hydrogen peroxide (H2O2) were 321+/-158 pptv, 650+/-176 pptv and 330+/-147 pptv. While MHP was detected, but not quantified in December 2000, levels in summer 2001 and 2002 were 317+128 pptv and 304+/-172.2 pptv. Results from firn air experiments and diurnal variability of the two species showed that atmospheric H2O2 is significantly impacted by a physical snow pack source between 76 and 90degS, whereas MHP is not. We show strong evidence of a positive feedback between stratospheric ozone and H2O2 at the surface. Between November-27 and December-12 in 2001, when ozone column densities dropped below 220 DU (means in 2000 and 2001 were 318 DU and 334 DU, respectively), H2O2 was 1.7 times that observed in the same period in 2000 and 2002, while MHP was only 80% of the levels encountered in 2002. Photochemical box model runs suggest that NO and OH levels on WAIS are closer to coastal values, while Antarctic Plateau levels are higher, confirming that region to be a highly oxidizing environment. The modeled sensitivity of H2O2 and particularly MHP to NO offers the potential to use atmospheric hydroperoxides to constrain the NO background and thus estimate the past oxidation capacity of the remote atmosphere. Index Terms: 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry; 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 1610 Global Change: Atmosphere (03

  12. Distinct composition of human fetal HDL attenuates its anti-oxidative capacity.

    PubMed

    Sreckovic, Ivana; Birner-Gruenberger, Ruth; Obrist, Britta; Stojakovic, Tatjana; Scharnagl, Hubert; Holzer, Michael; Scholler, Monika; Philipose, Sonia; Marsche, Gunther; Lang, Uwe; Desoye, Gernot; Wadsack, Christian

    2013-04-01

    In human high-density lipoprotein (HDL) represents the major cholesterol carrying lipoprotein class in cord blood, while cholesterol is mainly carried by low-density lipoprotein in maternal serum. Additionally, to carrying cholesterol, HDL also associates with a range of proteins as cargo. We tested the hypothesis that fetal HDL carries proteins qualitatively and quantitatively different from maternal HDL. These differences then contribute to distinct HDL functionality in both circulations. Shotgun proteomics and biochemical analyses were used to assess composition/function of fetal and maternal HDL isolated from uncomplicated human pregnancies at term of gestation. The pattern of analyzed proteins that were statistically elevated in fetal HDL (apoE, proteins involved in coagulation, transport processes) suggests a particle characteristic for the light HDL2 sub-fraction. In contrast, proteins that were enriched in maternal HDL (apoL, apoF, PON1, apoD, apoCs) have been described almost exclusively in the dense HDL3 fraction and relevant to its anti-oxidative function and role in innate immunity. Strikingly, PON1 mass and activity were 5-fold lower (p<0.01) in the fetus, which was accompanied by attenuation of anti-oxidant capacity of fetal HDL. Despite almost equal quantity of CETP in maternal and fetal HDL, its enzymatic activity was 55% lower (p<0.001) in the fetal circulation, whereas LCAT activity was not altered. These findings indicate that maternally derived HDL differs from fetal HDL with respect to its proteome, size and function. Absence of apoA-1, apoL and PON1 on fetal HDL is associated with decreased anti-oxidative properties together with deficiency in innate immunity collectively indicating distinct HDLs in fetuses. PMID:23321267

  13. Local atomic structure modulations activate metal oxide as electrocatalyst for hydrogen evolution in acidic water

    PubMed Central

    Li, Yu Hang; Liu, Peng Fei; Pan, Lin Feng; Wang, Hai Feng; Yang, Zhen Zhong; Zheng, Li Rong; Hu, P.; Zhao, Hui Jun; Gu, Lin; Yang, Hua Gui

    2015-01-01

    Modifications of local structure at atomic level could precisely and effectively tune the capacity of materials, enabling enhancement in the catalytic activity. Here we modulate the local atomic structure of a classical but inert transition metal oxide, tungsten trioxide, to be an efficient electrocatalyst for hydrogen evolution in acidic water, which has shown promise as an alternative to platinum. Structural analyses and theoretical calculations together indicate that the origin of the enhanced activity could be attributed to the tailored electronic structure by means of the local atomic structure modulations. We anticipate that suitable structure modulations might be applied on other transition metal oxides to meet the optimal thermodynamic and kinetic requirements, which may pave the way to unlock the potential of other promising candidates as cost-effective electrocatalysts for hydrogen evolution in industry. PMID:26286479

  14. Local atomic structure modulations activate metal oxide as electrocatalyst for hydrogen evolution in acidic water.

    PubMed

    Li, Yu Hang; Liu, Peng Fei; Pan, Lin Feng; Wang, Hai Feng; Yang, Zhen Zhong; Zheng, Li Rong; Hu, P; Zhao, Hui Jun; Gu, Lin; Yang, Hua Gui

    2015-01-01

    Modifications of local structure at atomic level could precisely and effectively tune the capacity of materials, enabling enhancement in the catalytic activity. Here we modulate the local atomic structure of a classical but inert transition metal oxide, tungsten trioxide, to be an efficient electrocatalyst for hydrogen evolution in acidic water, which has shown promise as an alternative to platinum. Structural analyses and theoretical calculations together indicate that the origin of the enhanced activity could be attributed to the tailored electronic structure by means of the local atomic structure modulations. We anticipate that suitable structure modulations might be applied on other transition metal oxides to meet the optimal thermodynamic and kinetic requirements, which may pave the way to unlock the potential of other promising candidates as cost-effective electrocatalysts for hydrogen evolution in industry. PMID:26286479

  15. Formation of phenol under conditions of the reaction of oxidative carbonylation of benzene to benzoic acid

    SciTech Connect

    Kalinovsky, I.O.; Leshcheva, A.N.; Pogorelov, V.V.; Gelbshtein, A.I.

    1993-12-31

    This paper describes conditions for the oxidation of benzene to phenol. It is shown that a reaction mixture of water, carbon monoxide, and oxygen are essential to the oxidation. The oxidation is a side reaction found to occur during the oxidative carbonylation of benzene to benzoic acid in a medium of trifluoroacetic acid.

  16. All-trans retinoic acid induces oxidative phosphorylation and mitochondria biogenesis in adipocytes[S

    PubMed Central

    Tourniaire, Franck; Musinovic, Hana; Gouranton, Erwan; Astier, Julien; Marcotorchino, Julie; Arreguin, Andrea; Bernot, Denis; Palou, Andreu; Bonet, M. Luisa; Ribot, Joan; Landrier, Jean-François

    2015-01-01

    A positive effect of all-trans retinoic acid (ATRA) on white adipose tissue (WAT) oxidative and thermogenic capacity has been described and linked to an in vivo fat-lowering effect of ATRA in mice. However, little is known about the effects of ATRA on mitochondria in white fat. Our objective has been to characterize the effect of ATRA on mitochondria biogenesis and oxidative phosphorylation (OXPHOS) capacity in mature white adipocytes. Transcriptome analysis, oxygraphy, analysis of mitochondrial DNA (mtDNA), and flow cytometry-based analysis of mitochondria density were performed in mature 3T3-L1 adipocytes after 24 h incubation with ATRA (2 µM) or vehicle. Selected genes linked to mitochondria biogenesis and function and mitochondria immunostaining were analyzed in WAT tissues of ATRA-treated as compared with vehicle-treated mice. ATRA upregulated the expression of a large set of genes linked to mtDNA replication and transcription, mitochondrial biogenesis, and OXPHOS in adipocytes, as indicated by transcriptome analysis. Oxygen consumption rate, mtDNA content, and staining of mitochondria were increased in the ATRA-treated adipocytes. Similar results were obtained in WAT depots of ATRA-treated mice. We conclude that ATRA impacts mitochondria in adipocytes, leading to increased OXPHOS capacity and mitochondrial content in these cells. PMID:25914170

  17. Humic substances and trace metals associated with Fe and Al oxides deposited in an acidic mountain stream

    USGS Publications Warehouse

    McKnight, Diane M.; Wershaw, R. L.; Bencala, K.E.; Zellweger, G.W.; Feder, G.L.

    1992-01-01

    Hydrous iron and aluminum oxides are deposited on the streambed in the confluence of the Snake River and Deer Creek, two streams in the Colorado Rocky Mountains. The Snake River is acidic and has high concentrations of dissolved Fe and Al. These metals precipitate at the confluence with the pristine, neutral pH, Deer Creek because of the greater pH (4.5-6.0) in the confluence. The composition of the deposited oxides changes consistently with distance downstream, with the most upstream oxide samples having the greatest Fe and organic carbon content. Fulvic acid accounts for most of the organic content of the oxides. Results indicate that streambed oxides in the confluence are not saturated with respect to their capacity to sorb dissolved humic substances from streamwater. The contents of several trace metals (Mn, Zn, Cu, Pb, Ni and Co) also decrease with distance downstream and are correlated with both the Fe and organic carbon contents. Strong metal-binding sites associated with the sorbed fulvic acid are more than sufficient to account for the trace metal content of the oxides. Complexation of trace metals by sorbed fulvic acid may explain the observed downstream decrease in trace metal content.

  18. Sulfuric Acid Intercalated Graphite Oxide for Graphene Preparation

    NASA Astrophysics Data System (ADS)

    Hong, Yanzhong; Wang, Zhiyong; Jin, Xianbo

    2013-12-01

    Graphene has shown enormous potential for innovation in various research fields. The current chemical approaches based on exfoliation of graphite via graphite oxide (GO) are potential for large-scale synthesis of graphene but suffer from high cost, great operation difficulties, and serious waste discharge. We report a facile preparation of graphene by rapid reduction and expansion exfoliation of sulfuric acid intercalated graphite oxide (SIGO) at temperature just above 100°C in ambient atmosphere, noting that SIGO is easily available as the immediate oxidation descendent of graphite in sulfuric acid. The oxygenic and hydric groups in SIGO are mainly removed through dehydration as catalyzed by the intercalated sulfuric acid (ISA). The resultant consists of mostly single layer graphene sheets with a mean diameter of 1.07 μm after dispersion in DMF. This SIGO process is reductant free, easy operation, low-energy, environmental friendly and generates graphene with low oxygen content, less defect and high conductivity. The provided synthesis route from graphite to graphene via SIGO is compact and readily scalable.

  19. Sulfuric Acid Intercalated Graphite Oxide for Graphene Preparation

    PubMed Central

    Hong, Yanzhong; Wang, Zhiyong; Jin, Xianbo

    2013-01-01

    Graphene has shown enormous potential for innovation in various research fields. The current chemical approaches based on exfoliation of graphite via graphite oxide (GO) are potential for large-scale synthesis of graphene but suffer from high cost, great operation difficulties, and serious waste discharge. We report a facile preparation of graphene by rapid reduction and expansion exfoliation of sulfuric acid intercalated graphite oxide (SIGO) at temperature just above 100°C in ambient atmosphere, noting that SIGO is easily available as the immediate oxidation descendent of graphite in sulfuric acid. The oxygenic and hydric groups in SIGO are mainly removed through dehydration as catalyzed by the intercalated sulfuric acid (ISA). The resultant consists of mostly single layer graphene sheets with a mean diameter of 1.07 μm after dispersion in DMF. This SIGO process is reductant free, easy operation, low-energy, environmental friendly and generates graphene with low oxygen content, less defect and high conductivity. The provided synthesis route from graphite to graphene via SIGO is compact and readily scalable. PMID:24310650

  20. High glucose levels reduce fatty acid oxidation and increase triglyceride accumulation in human placenta.

    PubMed

    Visiedo, Francisco; Bugatto, Fernando; Sánchez, Viviana; Cózar-Castellano, Irene; Bartha, Jose L; Perdomo, Germán

    2013-07-15

    Placentas of women with gestational diabetes mellitus (GDM) exhibit an altered lipid metabolism. The mechanism by which GDM is linked to alterations in placental lipid metabolism remains obscure. We hypothesized that high glucose levels reduce mitochondrial fatty acid oxidation (FAO) and increase triglyceride accumulation in human placenta. To test this hypothesis, we measured FAO, fatty acid esterification, de novo fatty acid synthesis, triglyceride levels, and carnitine palmitoyltransferase activities (CPT) in placental explants of women with GDM or no pregnancy complication. In women with GDM, FAO was reduced by ~30% without change in mitochondrial content, and triglyceride content was threefold higher than in the control group. Likewise, in placental explants of women with no complications, high glucose levels reduced FAO by ~20%, and esterification increased linearly with increasing fatty acid concentrations. However, de novo fatty acid synthesis remained unchanged between high and low glucose levels. In addition, high glucose levels increased triglyceride content approximately twofold compared with low glucose levels. Furthermore, etomoxir-mediated inhibition of FAO enhanced esterification capacity by ~40% and elevated triglyceride content 1.5-fold in placental explants of women, with no complications. Finally, high glucose levels reduced CPT I activity by ~70% and phosphorylation levels of acetyl-CoA carboxylase by ~25% in placental explants of women, with no complications. We reveal an unrecognized regulatory mechanism on placental fatty acid metabolism by which high glucose levels reduce mitochondrial FAO through inhibition of CPT I, shifting flux of fatty acids away from oxidation toward the esterification pathway, leading to accumulation of placental triglycerides. PMID:23673156

  1. Description of urolithin production capacity from ellagic acid of two human intestinal Gordonibacter species.

    PubMed

    Selma, María V; Beltrán, David; García-Villalba, Rocío; Espín, Juan C; Tomás-Barberán, Francisco A

    2014-08-01

    Ellagitannin and ellagic acid metabolism to urolithins in the gut shows a large human interindividual variability and this has been associated with differences in the colon microbiota. In the present study we describe the isolation of one urolithin-producing strain from the human faeces of a healthy volunteer and the ellagic acid transformation to different urolithin metabolites by two species of intestinal bacteria. The isolate belongs to a new species described as Gordonibacter urolithinfaciens, sp. nov. The type strain of the Gordonibacter genus, Gordonibacter pamelaeae DSM 19378(T), was also demonstrated to produce urolithins. Both human intestinal bacteria grew similarly in the presence and absence of ellagic acid at 30 μM concentration. Ellagic acid catabolism and urolithin formation occurred during the stationary phase of the growth of the bacteria under anaerobic conditions. The HPLC-MS analyses showed the sequential production of pentahydroxy-urolithin (urolithin M-5), tetrahydroxy-urolithin (urolithin M-6) and trihydroxy-urolithin (urolithin C), while dihydroxy-urolithins (urolithin A and isourolithin A), and monohydroxy-urolithin (urolithin B) were not produced in pure cultures. Consequently, either other bacteria from the gut or the physiological conditions found in vivo are necessary for completing metabolism until the final urolithins (dihydroxy and monohydroxy urolithins) are produced. This is the first time that the urolithin production capacity of pure strains has been demonstrated. The identification of the urolithin-producing bacteria is a relevant outcome as urolithin implication in health (cardiovascular protection, anti-inflammatory and anticarcinogenic properties) has been supported by different bioassays and urolithins can be used in the development of functional foods and nutraceuticals. This study represents an initial work that opens interesting possibilities of describing enzymatic activities involved in urolithin production that can

  2. Capacity and peak power degradation of lead-acid battery under simulated electric vehicle operations

    NASA Astrophysics Data System (ADS)

    Lee, J.; Tummillo, A. F.; Miller, J. F.; Hornstra, F.; Christianson, C. C.

    In a program supported by the Electric Power Research Institute, controlled laboratory tests were conducted at Argonne to evaluate the effects of selected EV application factors on the performance and life of the EV-2300 lead-acid battery. These application factors included simulated driving profile discharges with different levels of peak power demands for vehicle acceleration, long rest times after charge or discharge, and different methods of recharging. The performance and life variations among cells and modules in a full-scale battery pack were also examined. Statistical methods were used to analyze the laboratory test data. The key factors affecting the performance and life of the battery were identified, and the rates of capacity and power degradation were quantified using multiple regression techniques. The analyses show that the most significant factors were peak power demand levels and cell location within the six-cell modules. The effects of charge method and rest times were found to be small.

  3. Influence of oxidation on fulvic acids composition and biodegradability.

    PubMed

    Kozyatnyk, Ivan; Świetlik, Joanna; Raczyk-Stanisławiak, Ursula; Dąbrowska, Agata; Klymenko, Nataliya; Nawrocki, Jacek

    2013-08-01

    Oxidation is well-known process of transforming natural organic matter during the treatment of drinking water. Chlorine, ozone, and chlorine dioxide are common oxidants used in water treatment technologies for this purpose. We studied the influence of different doses of these oxidants on by-products formation and changes in biodegradable dissolved organic carbon (BDOC) and molecular weight distribution (MWD) of fulvic acids (FA) with different BDOC content. Chlorination did not significantly change the MWD of FA and disinfection by-products formation. However, higher molecular weight compounds, than those in the initial FA, were formed. It could be a result of chlorine substitution into the FA structure. Chlorine dioxide oxidized FA stronger than chlorine. During ozonation of FA, we found the highest increase of BDOD due to the formation of a high amount of organic acids and aldehydes. FA molecules were transformed into a more biodegradable form. Ozonation is the most preferable process among those observed for pre-treatment of FA before biofiltration. PMID:23746389

  4. Aflatoxin B1 binding capacity of autochthonous strains of lactic acid bacteria.

    PubMed

    Fazeli, Mohammad R; Hajimohammadali, M; Moshkani, Azamossadat; Samadi, Nasrin; Jamalifar, Hossein; Khoshayand, Mohammad R; Vaghari, Elham; Pouragahi, Samieh

    2009-01-01

    Some foods are prone to contamination with aflatoxins, with detrimental effect on human health. Lactic acid bacteria have been reported to bind aflatoxins and remove them from foods and feeds. Reduction of aflatoxin B1 (AFB1) from the liquid media by the autochthonous lactic acid bacteria (Lactobacillus casei, Lactobacillus plantarum, and Lactobacillus fermentum) isolated from traditional Iranian sourdough and dairy products is reported in the current study. The effect of incubation time on the binding capacity of the strains to AFB1 was also investigated. Duplicates of individual bacteria with population equivalent to 2 X 10(10) CFU/ml were incubated in the presence of AFB1 at 37 degrees C for a period of 72 h, and the amounts of unbound AFB1 were quantitated by reverse-phase high-performance liquid chromatography. All the strains were capable of removal of AFB1, and the reduction of AFB1 ranged from 25 to 61% throughout the incubation period. Removal of AFB1 was a rapid process, with approximately 61 and 56% of the toxin taken instantly by L. fermentum and L. plantarum, respectively. Binding was of a reversible nature, and some of the bound AFB1 was released into the media by the repeated centrifugation and resuspension of the cell pellets. The stability of the bacteria-toxin complex was strain dependent, and L. casei was a stronger binder of AFB1 compared with the other bacteria. No toxin release was observed after 24 h. These findings tend to suggest that certain novel probiotic bacteria with high aflatoxin binding capacity could be selected for detoxification of foods. PMID:19205485

  5. Hemolytic activity and solubilizing capacity of raffinose and melezitose fatty acid monoesters prepared by enzymatic synthesis.

    PubMed

    Carvalho, Luis; Morales, Juan C; Pérez-Victoria, José M; Pérez-Victoria, Ignacio

    2015-05-01

    The hemolytic activity and solubilizing capacity of two families of non-reducing trisaccharide fatty acid monoesters have been studied to assess their usefulness as surfactants for pharmaceutical applications. The carbohydrate-based surfactants investigated included homologous series of raffinose and melezitose monoesters bearing C10 to C18 acyl chains prepared by lipase-catalyzed synthesis in organic media. The hemolytic activity was determined in vitro using a static method based on the addition of the surfactants to an erythrocyte suspension and subsequent spectrophotometric determination of the released hemoglobin. The effect of the carbohydrate head group, the acyl chain length and the regioisomeric purity was investigated. In all cases, the carbohydrate monoester surfactants decreased their hemolytic activity (with respect to their critical micelle concentration) when increasing the length of the acyl chain. A very similar behaviour was observed either the carbohydrate head-group (raffinose and melezitose) or regardless of the regioisomeric purity. Interestingly, decanoyl (C10) and lauroyl (C12) monoesters were just marginally hemolytic at their critical micelle concentrations while the longer palmitoyl (C16) and (C18) stearoyl monoesters become hemolytic at concentrations much higher than their respective cmc. The palmitoyl and stearoyl monoesters also displayed higher solubilization capacity than the shorter acyl chain monoesters in a solubilization assay of a hydrophobic dye as a model drug mimic. These results suggest that raffinose and melezitose monoesters with long-chain fatty acids (C16 to C18) are promising surfactants for pharmaceutical applications and could be an alternative to the use of current commercial nonionic polyoxyethylene-based surfactants in parenteral formulations. PMID:25753196

  6. Polysialic acid sustains cancer cell survival and migratory capacity in a hypoxic environment

    PubMed Central

    Elkashef, Sara M.; Allison, Simon J.; Sadiq, Maria; Basheer, Haneen A.; Ribeiro Morais, Goreti; Loadman, Paul M.; Pors, Klaus; Falconer, Robert A.

    2016-01-01

    Polysialic acid (polySia) is a unique carbohydrate polymer expressed on the surface of NCAM (neuronal cell adhesion molecule) in a number of cancers where it modulates cell-cell and cell-matrix adhesion, migration, invasion and metastasis and is strongly associated with poor clinical prognosis. We have carried out the first investigation into the effect of polySia expression on the behaviour of cancer cells in hypoxia, a key source of chemoresistance in tumours. The role of polysialylation and associated tumour cell migration and cell adhesion were studied in hypoxia, along with effects on cell survival and the potential role of HIF-1. Our findings provide the first evidence that polySia expression sustains migratory capacity and is associated with tumour cell survival in hypoxia. Initial mechanistic studies indicate a potential role for HIF-1 in sustaining polySia-mediated migratory capacity, but not cell survival. These data add to the growing body of evidence pointing to a crucial role for the polysialyltransferases (polySTs) in neuroendocrine tumour progression and provide the first evidence to suggest that polySia is associated with an aggressive phenotype in tumour hypoxia. These results have significant potential implications for polyST inhibition as an anti-metastatic therapeutic strategy and for targeting hypoxic cancer cells. PMID:27611649

  7. Dasatinib accelerates valproic acid-induced acute myeloid leukemia cell death by regulation of differentiation capacity.

    PubMed

    Heo, Sook-Kyoung; Noh, Eui-Kyu; Yoon, Dong-Joon; Jo, Jae-Cheol; Park, Jae-Hoo; Kim, Hawk

    2014-01-01

    Dasatinib is a compound developed for chronic myeloid leukemia as a multi-targeted kinase inhibitor against wild-type BCR-ABL and SRC family kinases. Valproic acid (VPA) is an anti-epileptic drug that also acts as a class I histone deacetylase inhibitor. The aim of this research was to determine the anti-leukemic effects of dasatinib and VPA in combination and to identify their mechanism of action in acute myeloid leukemia (AML) cells. Dasatinib was found to exert potent synergistic inhibitory effects on VPA-treated AML cells in association with G1 phase cell cycle arrest and apoptosis induction involving the cleavage of poly (ADP-ribose) polymerase and caspase-3, -7 and -9. Dasatinib/VPA-induced cell death thus occurred via caspase-dependent apoptosis. Moreover, MEK/ERK and p38 MAPK inhibitors efficiently inhibited dasatinib/VPA-induced apoptosis. The combined effect of dasatinib and VPA on the differentiation capacity of AML cells was more powerful than the effect of each drug alone, being sufficiently strong to promote AML cell death through G1 cell cycle arrest and caspase-dependent apoptosis. MEK/ERK and p38 MAPK were found to control dasatinib/VPA-induced apoptosis as upstream regulators, and co-treatment with dasatinib and VPA to contribute to AML cell death through the regulation of differentiation capacity. Taken together, these results indicate that combined dasatinib and VPA treatment has a potential role in anti-leukemic therapy. PMID:24918603

  8. High-capacity magnetic hollow porous molecularly imprinted polymers for specific extraction of protocatechuic acid.

    PubMed

    Li, Hui; Hu, Xin; Zhang, Yuping; Shi, Shuyun; Jiang, Xinyu; Chen, Xiaoqin

    2015-07-24

    Magnetic hollow porous molecularly imprinted polymers (HPMIPs) with high binding capacity, fast mass transfer, and easy magnetic separation have been fabricated for the first time. In this method, HPMIPs was firstly synthesized using protocatechuic acid (PCA) as template, 4-vinylpyridine (4-VP) as functional monomer, glycidilmethacrylate (GMA) as co-monomer, and MCM-48 as sacrificial support. After that, epoxide ring of GMA was opened for chemisorbing Fe3O4 nanoparticles to prepare magnetic HPMIPs. The results of characterization indicated that magnetic HPMIPs exhibited large surface area (548m(2)/g) with hollow porous structure and magnetic sensitivity (magnetic saturation at 2.9emu/g). The following adsorption characteristics investigation exhibited surprisingly higher adsorption capacity (37.7mg/g), and faster kinetic binding (25min) than any previously reported PCA imprinted MIPs by traditional or surface imprinting technology. The equilibrium data fitted well to Langmuir equation and the adsorption process could be described by pseudo-second order model. The selective recognition experiments also demonstrated the high selectivity of magnetic HPMIPs towards PCA over analogues. The results of the real sample analysis confirmed the superiority of the proposed magnetic HPMIPs for selective and efficient enrichment of trace PCA from complex matrices. PMID:26044378

  9. Polysialic acid sustains cancer cell survival and migratory capacity in a hypoxic environment.

    PubMed

    Elkashef, Sara M; Allison, Simon J; Sadiq, Maria; Basheer, Haneen A; Ribeiro Morais, Goreti; Loadman, Paul M; Pors, Klaus; Falconer, Robert A

    2016-01-01

    Polysialic acid (polySia) is a unique carbohydrate polymer expressed on the surface of NCAM (neuronal cell adhesion molecule) in a number of cancers where it modulates cell-cell and cell-matrix adhesion, migration, invasion and metastasis and is strongly associated with poor clinical prognosis. We have carried out the first investigation into the effect of polySia expression on the behaviour of cancer cells in hypoxia, a key source of chemoresistance in tumours. The role of polysialylation and associated tumour cell migration and cell adhesion were studied in hypoxia, along with effects on cell survival and the potential role of HIF-1. Our findings provide the first evidence that polySia expression sustains migratory capacity and is associated with tumour cell survival in hypoxia. Initial mechanistic studies indicate a potential role for HIF-1 in sustaining polySia-mediated migratory capacity, but not cell survival. These data add to the growing body of evidence pointing to a crucial role for the polysialyltransferases (polySTs) in neuroendocrine tumour progression and provide the first evidence to suggest that polySia is associated with an aggressive phenotype in tumour hypoxia. These results have significant potential implications for polyST inhibition as an anti-metastatic therapeutic strategy and for targeting hypoxic cancer cells. PMID:27611649

  10. Oxidative degradation of nalidixic acid by nano-magnetite via Fe2+/O2-mediated reactions.

    PubMed

    Ardo, Sandy G; Nélieu, Sylvie; Ona-Nguema, Georges; Delarue, Ghislaine; Brest, Jessica; Pironin, Elsa; Morin, Guillaume

    2015-04-01

    Organic pollution has become a critical issue worldwide due to the increasing input and persistence of organic compounds in the environment. Iron minerals are potentially able to degrade efficiently organic pollutants sorbed to their surfaces via oxidative or reductive transformation processes. Here, we explored the oxidative capacity of nano-magnetite (Fe3O4) having ∼ 12 nm particle size, to promote heterogeneous Fenton-like reactions for the removal of nalidixic acid (NAL), a recalcitrant quinolone antibacterial agent. Results show that NAL was adsorbed at the surface of magnetite and was efficiently degraded under oxic conditions. Nearly 60% of this organic contaminant was eliminated after 30 min exposure to air bubbling in solution in the presence of an excess of nano-magnetite. X-ray diffraction (XRD) and Fe K-edge X-ray absorption spectroscopy (XANES and EXAFS) showed a partial oxidation of magnetite to maghemite during the reaction, and four byproducts of NAL were identified by liquid chromatography-mass spectroscopy (UHPLC-MS/MS). We also provide evidence that hydroxyl radicals (HO(•)) were involved in the oxidative degradation of NAL, as indicated by the quenching of the degradation reaction in the presence of ethanol. This study points out the promising potentialities of mixed valence iron oxides for the treatment of soils and wastewater contaminated by organic pollutants. PMID:25756496

  11. Pro-oxidant actions of alpha-lipoic acid and dihydrolipoic acid.

    PubMed

    Cakatay, Ufuk

    2006-01-01

    There is strong accumulating evidence that a alpha-lipoic acid (LA) supplement is good insurance, and would markedly improve human health. LA is readily absorbed from the diet, transported to cells and reduced to dihydrolipoic acid (DHLA). Of the two compounds, DHLA evidently has greater antioxidant activity. Much research has focused on the antioxidant properties of these compounds. Aside from its antioxidant role, in vitro and in vivo studies suggest that LA and its reduced form DHLA also act as a pro-oxidant properties. Limited number of studies concerning the pro-oxidant potential of LA and DHLA were performed only in recent years. The ability of LA and/or DHLA to function as either anti- or pro-oxidants, at least in part, is determined by the type of oxidant stress and the physiological circumstances. These pro-oxidant actions suggest that LA and DHLA act by multiple mechanisms, many of which are only now being explored. LA has been reported to have a number of potentially beneficial effects in both prevention and treatment of oxygen-related diseases. Selection of appropriate pharmacological doses of LA for use in oxygen-related diseases is critical. On the other hand, much of the discussion in clinical studies has been devoted to the pro-oxidant role of LA. This aspect remains to be elucidated. In further studies, careful evaluation will be necessary for the decision in the biological system whether LA administration is beneficial or harmful. PMID:16165311

  12. Oxidation in Acidic Medium of Lignins from Agricultural Residues

    NASA Astrophysics Data System (ADS)

    Labat, Gisele Aparecida Amaral; Gonçalves, Adilson Roberto

    Agricultural residues as sugarcane straw and bagasse are burned in boilers for generation of energy in sugar and alcohol industries. However, excess of those by-products could be used to obtain products with higher value. Pulping process generates cellulosic pulps and lignin. The lignin could be oxidized and applied in effluent treatments for heavy metal removal. Oxidized lignin presents very strong chelating properties. Lignins from sugarcane straw and bagasse were obtained by ethanol-water pulping. Oxidation of lignins was carried out using acetic acid and Co/Mn/Br catalytical system at 50, 80, and 115 °C for 5 h. Kinetics of the reaction was accomplished by measuring the UV-visible region. Activation energy was calculated for lignins from sugarcane straw and bagasse (34.2 and 23.4 kJ mol-1, respectively). The first value indicates higher cross-linked formation. Fourier-transformed infrared spectroscopy data of samples collected during oxidation are very similar. Principal component analysis applied to spectra shows only slight structure modifications in lignins after oxidation reaction.

  13. Properties of nanocellulose isolated from corncob residue using sulfuric acid, formic acid, oxidative and mechanical methods.

    PubMed

    Liu, Chao; Li, Bin; Du, Haishun; Lv, Dong; Zhang, Yuedong; Yu, Guang; Mu, Xindong; Peng, Hui

    2016-10-20

    In this work, nanocellulose was extracted from bleached corncob residue (CCR), an underutilized lignocellulose waste from furfural industry, using four different methods (i.e. sulfuric acid hydrolysis, formic acid (FA) hydrolysis, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation, and pulp refining, respectively). The self-assembled structure, morphology, dimension, crystallinity, chemical structure and thermal stability of prepared nanocellulose were investigated. FA hydrolysis produced longer cellulose nanocrystals (CNCs) than the one obtained by sulfuric acid hydrolysis, and resulted in high crystallinity and thermal stability due to its preferential degradation of amorphous cellulose and lignin. The cellulose nanofibrils (CNFs) with fine and individualized structure could be isolated by TEMPO-mediated oxidation. In comparison with other nanocellulose products, the intensive pulp refining led to the CNFs with the longest length and the thickest diameter. This comparative study can help to provide an insight into the utilization of CCR as a potential source for nanocellulose production. PMID:27474618

  14. Phenolic composition, ascorbic acid content, and antioxidant capacity of Spanish jujube (Ziziphus jujube Mill.) fruits.

    PubMed

    Wojdyło, Aneta; Carbonell-Barrachina, Ángel A; Legua, Pilar; Hernández, Francisca

    2016-06-15

    The interest in Ziziphus jujube is growing because it is an excellent source of nutrients and phytochemicals, and can contribute to a healthy diet. Nutritional compounds (phenolic compounds and L-ascorbic acid), and antioxidant capacity of 4 Spanish jujube cultivars were studied. Polyphenols were identified by LC-MS-QTof and quantified by UPLC-PDA-FL. A total of 25 polyphenolic compounds were identified and classified as 10 flavan-3-ols, 13 flavonols, 1 flavanone, and 1 dihydrochalcone. The content of total polyphenols (TP) ranged from 1442 to 3432 mg/100 g dry matter (dm) in fruits of the cultivars 'DAT' and 'PSI', respectively. Flavan-3-ols, the major group of polyphenols in jujube represented ∼92% of the TP content, whereas flavonols only amounted for about ∼8% each. The content of L-ascorbic acid was very high and took values in the range of 387-555 mg/100 g fresh weight (fw). Some Spanish jujube cultivars, especially 'PSI' and 'MSI', may be selected to promote the growth of cultivars with valuable nutritional and phytochemical beneficial effects on human health. PMID:26868581

  15. Factors contributing to differences in acid-neutralizing capacity among lakes in the western United States

    SciTech Connect

    Eilers, J.M.; Landers, D.H.; Brakke, D.F.; Linthurst, R.A.

    1987-09-01

    A survey of lakes in mountainous areas of the Western United States was conducted in fall 1985 by the US Environmental Protection Agency (EPA) in cooperation with the USDA - Forest Service. Of the 719 probability sample lakes, only one was acidic; 99% of the lakes were estimated to have pH>6.0. However, acid-neutralizing capacity (ANC) was < or = 50 microeq L-1 for an estimated 16.8% of the lakes in the study area. Of the five subregions in the West, California had the highest proportion of lakes with ANC < or = 50 microeq L-1 (36.7%) and the Southern Rocky Mountains had the lowest proportion (4.6%). The lakes in the West were post-stratified into geomorphic units corresponding to major mountain ranges. Watershed factors, including watershed area, lake area, watershed area: lake area ratio, lake depth, watershed slope, percent exposed bedrock, elevation, and hydraulic residence time, were examined within six geomorphic units in order to evaluate their relationship to lake ANC. These watershed variables had poor predictive capability with respect to ANC. The results suggest that higher-resolution information for factors such as mineralogy and hydrology are required for prediction of lake ANC within a given geomorphic unit.

  16. An unexpected large capacity of ultrafine manganese oxide as a sodium-ion battery anode

    NASA Astrophysics Data System (ADS)

    Weng, Yu-Ting; Huang, Tzu-Yang; Lim, Chek-Hai; Shao, Pei-Sian; Hy, Sunny; Kuo, Chao-Yen; Cheng, Ju-Hsiang; Hwang, Bing-Joe; Lee, Jyh-Fu; Wu, Nae-Lih

    2015-11-01

    MnO2 is shown for the first time to be electrochemically active as a conversion anode for Na-ion batteries (NIBs). Space-confined ultrafine (UF)-MnO2, with an average crystal size of 4 nm, synthesized using a porous silicon dioxide templated hydrothermal process exhibits a high reversible sodiation capacity of 567 mA h g-1, in contrast to the negligible activity shown by the aggregates of larger (14 nm) MnO2 nanocrystallites. The remarkably enhanced sodiation activity of the UF-MnO2 is attributable to its greatly reduced crystal size, which facilitates diffusion of Na ions, along with high surface energy arising from extensive heterogeneous interfacial bonding with the SiO2 surrounding. The UF-MnO2 anode exhibits an exceptional rate and cycle performance, exhibiting >70% capacity retention after 500 cycles. In operando synchrotron X-ray absorption near-edge structural analysis reveals combined charge-storage mechanisms involving conversion reaction between Mn(iii) and Mn(ii) oxides, Mn(iii)-O1.5 + Na+ + e-- <--> 1/2Na2O + Mn(ii)-O, and non-Mn-centered redox reactions. The finding suggests a new strategy for ``activating'' the potential electrochemical electrode materials that appear inactive in the bulk form.MnO2 is shown for the first time to be electrochemically active as a conversion anode for Na-ion batteries (NIBs). Space-confined ultrafine (UF)-MnO2, with an average crystal size of 4 nm, synthesized using a porous silicon dioxide templated hydrothermal process exhibits a high reversible sodiation capacity of 567 mA h g-1, in contrast to the negligible activity shown by the aggregates of larger (14 nm) MnO2 nanocrystallites. The remarkably enhanced sodiation activity of the UF-MnO2 is attributable to its greatly reduced crystal size, which facilitates diffusion of Na ions, along with high surface energy arising from extensive heterogeneous interfacial bonding with the SiO2 surrounding. The UF-MnO2 anode exhibits an exceptional rate and cycle performance

  17. Ferrate(VI) oxidation of weak-acid dissociable cyanides.

    PubMed

    Yngard, Ria A; Sharma, Virender K; Filip, Jan; Zboril, Radek

    2008-04-15

    Cyanide is commonly found in electroplating, mining, coal gasification, and petroleum refining effluents, which require treatment before being discharged. Cyanide in effluents exists either as free cyanide or as a metal complex. The kinetics of the oxidation of weak-acid dissociable cyanides by an environmentally friendly oxidant, ferrate(VI) (Fe(VI)O4(2-), Fe(VI)), were studied as a function of pH (9.1-10.5) and temperature (15-45 degrees C) using a stopped-flow technique. The weak-acid dissociable cyanides were Cd(CN)4(2-) and Ni(CN)4(2-), and the rate-laws for the oxidation may be -d[Fe(VI)]/dt = k[Fe(VI)][M(CN)4(2-)]n where n = 0.5 and 1 for Cd(CN)4(2-) and Ni(CN)4(2-), respectively. The rates decreased with increasing pH and were mostly related to a decrease in concentration of the reactive protonated Fe(VI) species, HFeO4(-). The stoichiometries with Fe(VI) were determined to be: 4HFeO4(-) + M(CN)4(2-) + 6H2O --> 4Fe(OH)3 + M(2+) + 4NCO(-) + O2 + 4OH(-). Mechanisms are proposed that agree with the observed reaction rate-laws and stoichiometries of the oxidation of weak-acid dissociable cyanides by Fe(VI). Results indicate that Fe(VI) is effective in removing cyanide in coke oven plant effluent, where organics are also present. PMID:18497158

  18. Ferrate(VI) oxidation of weak-acid dissociable cyanides

    SciTech Connect

    Ria A. Yngard; Virender K. Sharma; Jan Filip; Radek Zboril

    2008-04-15

    Cyanide is commonly found in electroplating, mining, coal gasification, and petroleum refining effluents, which require treatment before being discharged. Cyanide in effluents exists either as free cyanide or as a metal complex. The kinetics of the oxidation of weak-acid dissociable cyanides by an environmentally friendly oxidant, ferrate, were studied as a function of pH (9.1-10.5) and temperature (15-45{sup o}C) using a stopped-flow technique. The weak-acid dissociable cyanides were Cd(CN){sub 4}{sup 2-} and Ni(CN){sub 4}{sup 2-}, and the rate-laws for the oxidation may be -d(Fe(VI))/dt = k (Fe(VI))(M(CN){sub 4}{sup 2-}){sup n} where n = 0.5 and 1 for Cd(CN){sub 4}{sup 2-} and Ni(CN){sub 4}{sup 2-}, respectively. The rates decreased with increasing pH and were mostly related to a decrease in concentration of the reactive protonated Fe(VI) species, HFeO{sub 4}{sup -}. The stoichiometries with Fe(VI) were determined to be: 4HFeO{sub 4}{sup -} + M(CN){sub 4}{sup 2-} + 6H{sub 2}O {yields} 4Fe(OH){sub 3} + M{sup 2+} + 4NCO{sup -} + O{sub 2} + 4OH{sup -}. Mechanisms are proposed that agree with the observed reaction rate-laws and stoichiometries of the oxidation of weak-acid dissociable cyanides by Fe(VI). Results indicate that Fe(VI) is effective in removing cyanide in coke oven plant effluent, where organics are also present. 27 refs., 3 figs., 2 tabs.

  19. Lung diffusing capacity for nitric oxide as a marker of fibrotic changes in idiopathic interstitial pneumonias.

    PubMed

    Barisione, Giovanni; Brusasco, Claudia; Garlaschi, Alessandro; Baroffio, Michele; Brusasco, Vito

    2016-05-01

    Lung diffusing capacity for carbon monoxide (DLCO) is decreased in both usual interstitial pneumonia-idiopathic pulmonary fibrosis (UIP-IPF) and nonspecific interstitial pneumonia (NSIP), but is moderately related to computed tomography (CT)-determined fibrotic changes. This may be due to the relative insensitivity of DLCO to changes in alveolar membrane diffusive conductance (DMCO). The purpose of this study was to determine whether measurement of lung diffusing capacity for nitric oxide (DLNO) better reflects fibrotic changes than DLCO DLNO-DLCO were measured simultaneously in 30 patients with UIP-IPF and 30 with NSIP. Eighty-one matched healthy subjects served as a control group. The amount of pulmonary fibrosis was estimated by CT volumetric analysis of visually bounded areas showing reticular opacities and honeycombing. DMCO and pulmonary capillary volume (VC) were calculated. DLNO was below the lower limit of normal in all patients irrespective of extent and nature of disease, whereas DLCO was within the normal range in a nonnegligible number of patients. Both DLNO and DLCO were significantly correlated with visual assessment of fibrosis but DLNO more closely than DLCO DMCO was also below the lower limit of normal in all UIP-IPF and NSIP patients and significantly correlated with fibrosis extent in both diseases, whereas VC was weakly correlated with fibrosis in UIP-IPF and uncorrelated in NSIP, with normal values in half of patients. In conclusion, measurement of DLNO may provide a more sensitive evaluation of fibrotic changes than DLCO in either UIP-IPF or NSIP, because it better reflects DMCO. PMID:26893034

  20. n-Alkane assimilation and tert-butyl alcohol (TBA) oxidation capacity in Mycobacterium austroafricanum strains.

    PubMed

    Lopes Ferreira, Nicolas; Mathis, Hugues; Labbé, Diane; Monot, Frédéric; Greer, Charles W; Fayolle-Guichard, Françoise

    2007-06-01

    Mycobacterium austroafricanum IFP 2012, which grows on methyl tert-butyl ether (MTBE) and on tert-butyl alcohol (TBA), the main intermediate of MTBE degradation, also grows on a broad range of n-alkanes (C2 to C16). A single alkB gene copy, encoding a non-heme alkane monooxygenase, was partially amplified from the genome of this bacterium. Its expression was induced after growth on n-propane, n-hexane, n-hexadecane and on TBA but not after growth on LB. The capacity of other fast-growing mycobacteria to grow on n-alkanes (C1 to C16) and to degrade TBA after growth on n-alkanes was compared to that of M. austroafricanum IFP 2012. We studied M. austroafricanum IFP 2012 and IFP 2015 able to grow on MTBE, M. austroafricanum IFP 2173 able to grow on isooctane, Mycobacterium sp. IFP 2009 able to grow on ethyl tert-butyl ether (ETBE), M. vaccae JOB5 (M. austroaafricanum ATCC 29678) able to degrade MTBE and TBA and M. smegmatis mc2 155 with no known degradation capacity towards fuel oxygenates. The M. austroafricanum strains grew on a broad range of n-alkanes and three were able to degrade TBA after growth on propane, hexane and hexadecane. An alkB gene was partially amplified from the genome of all mycobacteria and a sequence comparison demonstrated a close relationship among the M. austroafricanum strains. This is the first report suggesting the involvement of an alkane hydroxylase in TBA oxidation, a key step during MTBE metabolism. PMID:17347817

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

    SciTech Connect

    Grimes, Travis Shane; Mincher, Bruce Jay; Schmitt, Nicholas C

    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.

  2. 'Low-acid' sulfide oxidation using nitrate-enriched groundwater

    NASA Astrophysics Data System (ADS)

    Donn, Michael; Boxall, Naomi; Reid, Nathan; Meakin, Rebecca; Gray, David; Kaksonen, Anna; Robson, Thomas; Shiers, Denis

    2016-04-01

    Acid drainage (AMD/ARD) is undoubtedly one of the largest environmental, legislative and economic challenges facing the mining industry. In Australia alone, at least 60m is spent on AMD related issues annually, and the global cost is estimated to be in the order of tens of billions US. Furthermore, the challenge of safely and economically storing or treating sulfidic wastes will likely intensify because of the trend towards larger mines that process increasingly higher volumes of lower grade ores and the associated sulfidic wastes and lower profit margins. While the challenge of managing potentially acid forming (PAF) wastes will likely intensify, the industrial approaches to preventing acid production or ameliorating the effects has stagnated for decades. Conventionally, PAF waste is segregated and encapsulated in non-PAF tips to limit access to atmospheric oxygen. Two key limitations of the 'cap and cover' approach are: 1) the hazard (PAF) is not actually removed; only the pollutant linkage is severed; and, 2) these engineered structures are susceptible to physical failure in short-to-medium term, potentially re-establishing that pollutant linkage. In an effort to address these concerns, CSIRO is investigating a passive, 'low-acid' oxidation mechanism for sulfide treatment, which can potentially produce one quarter as much acidity compared with pyrite oxidation under atmospheric oxygen. This 'low-acid' mechanism relies on nitrate, rather than oxygen, as the primary electron accepter and the activity of specifically cultured chemolithoautotrophic bacteria and archaea communities. This research was prompted by the observation that, in deeply weathered terrains of Australia, shallow (oxic to sub-oxic) groundwater contacting weathering sulfides are commonly inconsistent with the geochemical conditions produced by ARD. One key characteristic of these aquifers is the natural abundance of nitrate on a regional scale, which becomes depleted around the sulfide bodies, and

  3. KINEMATIC VARIABLES AND BLOOD ACID-BASE STATUS IN THE ANALYSIS OF COLLEGIATE SWIMMERS’ ANAEROBIC CAPACITY

    PubMed Central

    Bielec, G.; Makar, P.; Laskowski, R.

    2013-01-01

    Short duration repeated maximal efforts are often used in swimming training to improve lactate tolerance, which gives swimmers the ability to maintain a high work rate for a longer period of time. The aim of the study was to examine the kinematics of swimming and its relation to the changes in blood acid-base status and potassium level. Seven collegiate swimmers, with at least 6 years of training experience, volunteered to participate in the study. The test consisted of 8 x 25 m front crawl performed with maximum effort. The rest period between repetitions was set to five seconds. Blood samples were taken from the fingertip at rest, after warm-up and in the 3rd minute after completion of the test. The swimming was recorded with a video recorder, for later analysis of time, velocity and technique (stroke index). Based on the swimming velocity results, the obtained curve can be divided into rapid decrease of velocity and relatively stable velocities. The breaking point of repetition in swimming velocity was assumed as the swimming velocity threshold and it was highly correlated with the decrease of the blood acid-base status (pH r=0.82, BE r=0.87, HCO3 - r=0.76; p<0.05 in all cases). There was no correlation between stroke index or fatigue index and blood acid-base status. Analysis of the swimming speed in the 8 x 25 m test seems to be helpful in evaluation of lactate tolerance (anaerobic capacity) in collegiate swimmers. PMID:24744491

  4. Evidence for an increase in the oxidative capacity of the atmosphere in the late twentieth century

    NASA Astrophysics Data System (ADS)

    Newland, Mike; Martinerie, Patricia; Witrant, Emmanuel; Helmig, Detlev; Worton, David; Hogan, Chris; Sturges, Bill; Reeves, Claire

    2016-04-01

    The hydroxyl radical, OH, is the dominant sink for the majority of trace gases in the troposphere. Thus, it plays a major role in controlling atmospheric chemical composition. However despite this importance there remains much uncertainty as to whether concentrations of OH have changed in the background atmosphere in recent decades. It has previously been reported that recent levels of OH in the troposphere (1997-2008) are well buffered against changes in atmospheric composition (Montzka et al., 2011). We present two independent records that suggest that there was a significant increase in concentrations of the OH radical in the northern hemisphere during the last two decades of the twentieth century. Measurements from Greenland firn air of the changing ratios of n-butane, iso-butane, n-pentane and iso-pentane were compared using a photochemical clock method. Using these changing ratios we calculate an increase in the chemical processing of the air (i.e. [OH].t) between 1980 and 2000. Assuming t to be constant this provides a semi-quantitative historic record of OH concentrations. Furthermore, measurements of three alkyl nitrates (also from Greenland firn air), secondary oxidation products of the alkanes, suggest an increase in the [NO]/[HO2] ratio in the background atmosphere. This could be indicative of increasing NOx concentrations during this period, which would be consistent with increasing [OH]. These two records are further corroborated by comparison with the long term trend in increasing ozone mixing ratios from background European sites. Knowledge of historic changes to the oxidative capacity of the atmosphere is fundamental to understanding the atmospheric records of trace gases and to determining historic trace gas emissions using top-down approaches. The results presented here have profound implications for our understanding of atmospheric composition in the past, the present and for predicting the future evolution of the atmosphere.

  5. Pecans acutely increase plasma postprandial antioxidant capacity and catechins and decrease LDL oxidation in humans.

    PubMed

    Hudthagosol, Chatrapa; Haddad, Ella Hasso; McCarthy, Katie; Wang, Piwen; Oda, Keiji; Sabaté, Joan

    2011-01-01

    Bioactive constituents of pecan nuts such as γ-tocopherol and flavan-3-ol monomers show antioxidant properties in vitro, but bioavailability in humans is not known. We examined postprandial changes in plasma oxygen radical absorbance capacity (ORAC) and in concentrations of tocopherols, catechins, oxidized LDL, and malondialdehyde (MDA) in response to pecan test meals. Sixteen healthy men and women (23-44 y, BMI 22.7 ± 3.4) were randomly assigned to 3 sequences of test meals composed of whole pecans, blended pecans, or an isocaloric meal of equivalent macronutrient composition but formulated of refined ingredients in a crossover design with a 1-wk washout period between treatments. Blood was sampled at baseline and at intervals up to 24 h postingestion. Following the whole and blended pecan test meals, plasma concentrations of γ-tocopherols doubled at 8 h (P < 0.001) and hydrophilic- and lipophilic-ORAC increased 12 and 10% at 2 h, respectively. Post whole pecan consumption, oxidized LDL decreased 30, 33, and 26% at 2, 3, and 8 h, respectively (P < 0.05), and epigallocatechin-3-gallate concentrations at 1 h (mean ± SEM; 95.1 ± 30.6 nmol/L) and 2 h (116.3 ± 80.5 nmol/L) were higher than at baseline (0 h) and after the control test meal at 1 h (P < 0.05). The postprandial molar ratio of MDA:triglycerides decreased by 37, 36, and 40% at 3, 5, and 8 h, respectively (P < 0.05), only when whole and blended pecan data were pooled. These results show that bioactive constituent of pecans are absorbable and contribute to postprandial antioxidant defenses. PMID:21106921

  6. Kolaviron and L-Ascorbic Acid Attenuate Chlorambucil-Induced Testicular Oxidative Stress in Rats

    PubMed Central

    2014-01-01

    Chlorambucil (4-[4-[bis(2-chloroethyl)amino]phenyl]butanoic acid) is an alkylating agent, indicated in chronic lymphocytic leukaemia. Kolaviron (KV), a biflavonoid complex from Garcinia kola, and L-ascorbic acid (AA) are known to protect against oxidative damage in vivo. This study evaluates the protective capacity of KV and AA on chlorambucil-induced oxidative stress in the testes of rat. Twenty male Wistar rats (180–200 g) were randomized into four groups: I: control, II: chlorambucil (0.2 mg/kg b.w.), III: 0.2 mg/kg chlorambucil and 100 mg/kg KV, and IV: 0.2 mg/kg chlorambucil and 100 mg/kg AA. After 14 days of treatments, results indicated that chlorambucil caused significant reduction (P < 0.05) in testicular vitamin C and glutathione by 32% and 39%, respectively, relative to control. Similarly, activities of testicular GST, SOD, and CAT reduced significantly by 48%, 47%, and 49%, respectively, in chlorambucil-treated rats relative to control. Testicular MDA and activities of ALP, LDH, and ACP were increased significantly by 53%, 51%, 64%, and 70%, respectively, in the chlorambucil-treated rat. However, cotreatment with KV and AA offered protection and restored the levels of vitamin C, GSH, and MDA as well as SOD, CAT, GST, ACP, ALP, and LDH activities. Overall, kolaviron and L-ascorbic acid protected against chlorambucil-induced damage in the testes of the rat. PMID:25309592

  7. The available capacity computation model based on artificial neural network for lead-acid batteries in electric vehicles

    NASA Astrophysics Data System (ADS)

    Chan, C. C.; Lo, E. W. C.; Weixiang, Shen

    The available capacity computation model based on the artificial neural network (ANN) for lead-acid batteries in an electric vehicle (EV) is presented. Comparing with the methods based on the Peukert equation, which is often used for the calculation of the available capacity for lead-acid batteries in EVs, this model is more accurate. The results of the experiment have proven the accuracy of the proposed model; the computation values are in good agreement with experimental data, the associated error has been considered acceptable from an engineering point of view.

  8. Oxidative stability of omega-3 polyunsaturated fatty acids enriched eggs.

    PubMed

    Ren, Yuan; Perez, Tulia I; Zuidhof, Martin J; Renema, Robert A; Wu, Jianping

    2013-11-27

    Omega-3 polyunsaturated fatty acids (n-3 PUFA) enriched eggs have a growing market share in the egg industry. This study examined the stability of n-3 PUFA enriched eggs fortified with antioxidants (vitamin E or organic Selenium [Sel-Plex] or both) following cooking and storage. The total fat content was not affected by cooking or simulated retail storage conditions, whereas, n-3 fatty acids were reduced. The content of n-3 fatty acids in boiled eggs was higher than in fried eggs. Lipid oxidation was significantly affected by the different cooking methods. Fried eggs contained higher levels of malondialdehyde (MDA, 2.02 μg/kg) and cholesterol oxidation products (COPs, 13.58 μg/g) compared to boiled (1.44 and 10.15 μg/kg) and raw eggs (0.95 and 9.03 μg/kg, respectively, for MDA and COPs). Supplementation of antioxidants reduced the formation of MDA by 40% and COPs by 12% in fried eggs. Although the content of MDA was significantly increased after 28 days of storage, COPs were not affected by storage. Our study indicated that the n-3 PUFA in enriched eggs was relatively stable during storage and home cooking in the presence of antioxidants. PMID:24164329

  9. Refractory Oxide Coatings on Titanium for Nitric Acid Applications

    NASA Astrophysics Data System (ADS)

    Ravi Shankar, A.; Kamachi Mudali, U.

    2014-07-01

    Tantalum and Niobium have good corrosion resistance in nitric acid as well as in molten chloride salt medium encountered in spent fuel nuclear reprocessing plants. Commercially, pure Ti (Cp-Ti) exhibits good corrosion resistance in nitric acid medium; however, in vapor condensates of nitric acid, significant corrosion was observed. In the present study, a thermochemical diffusion method was pursued to coat Ta2O5, Nb2O5, and Ta2O5 + Nb2O5 on Ti to improve the corrosion resistance and enhance the life of critical components in reprocessing plants. The coated samples were characterized by XRD, SEM, EDX, profilometry, micro-scratch test, and ASTM A262 Practice-C test in 65 pct boiling nitric acid. The SEM micrograph of the coated samples showed that uniform dense coating containing Ta2O5 and/or Nb2O5 was formed. XRD patterns indicated the formation of TiO2, Ta2O5/Nb2O5, and mixed oxide/solid solution phase on coated Ti samples. ASTM A262 Practice-C test revealed reproducible outstanding corrosion resistance of Ta2O5-coated sample in comparison to Nb2O5- and Ta2O5 + Nb2O5-coated sample. The hardness of the Ta2O5-coated Cp-Ti sample was found to be twice that of uncoated Cp-Ti. The SEM and XRD results confirmed the presence of protective oxide layer (Ta2O5, rutile TiO2, and mixed phase) on coated sample which improved the corrosion resistance remarkably in boiling liquid phase of nitric acid compared to uncoated Cp-Ti and Ti-5Ta-1.8Nb alloy. Three phase corrosion test conducted on Ta2O5-coated samples in boiling 11.5 M nitric acid showed poor corrosion resistance in vapor and condensate phases of nitric acid due to poor adhesion of the coating. The adhesive strength of the coated samples needs to be optimized in order to improve the corrosion resistance in vapor and condensate phases of nitric acid.

  10. Removal of arsenious acid from sulfuric acidic solution using ultrasound oxidation and goethite

    NASA Astrophysics Data System (ADS)

    Okawa, Hirokazu; Yoshikawa, Tomohiro; Hosokawa, Ryota; Hangui, Shinji; Kawamura, Youhei; Sugawara, Katsuyasu

    2015-07-01

    We investigated the properties of synthetic goethite for the adsorption of As from strongly acidic solutions in ambient atmosphere under ultrasound irradiation. The goethite was successfully synthesized from iron-containing sulfuric acidic solution (1271 ppm) using an autoclave apparatus for 1 h at 0.12 MPa and 121 °C. The ratio of the iron eluted from the synthetic goethite to the acidic solution was only 0.58% at pH 2.1. Ultrasound irradiation (200 kHz, 200 W) was applied to oxidize 10 ppm of As(III) to As(V) at pH 2.2 for 60 min under various atmospheric conditions. Remarkably, the oxidation ratio of As(III) to As(V) is quite high (89.7%) at pH 2.2 in ambient atmosphere and is close to those obtained for Ar (95.3%) and O2 (95.9%) atmospheres. The As(III) removal ratio reached 94.5% after 60 min of irradiation. Therefore, goethite is a promising material for As adsorption using ultrasound oxidation in the acidic region in ambient atmosphere.

  11. Nrf2-Mediated HO-1 Induction Coupled with the ERK Signaling Pathway Contributes to Indirect Antioxidant Capacity of Caffeic Acid Phenethyl Ester in HepG2 Cells

    PubMed Central

    Kim, Jin-Kyoung; Jang, Hae-Dong

    2014-01-01

    The objective of this study is to investigate the contributing effect of the nuclear transcription factor-erythroid 2-related factor 2 (Nrf2)-mediated signaling pathway on the indirect antioxidant capacity of caffeic acid phenethyl ester (CAPE) against oxidative stress in HepG2 cells. The result of an antioxidant response element (ARE)-luciferase assay showed that CAPE stimulated ARE promoter activity resulting in increased transcriptional and translational activities of heme oxygenase-1 (HO-1). In addition, CAPE treatment enhanced Nrf2 accumulation in the nucleus and the post-translational phosphorylation level of extracellular signal-regulated kinase (ERK) among several protein kinases tested. Treatment with ERK inhibitor U126 completely suppressed CAPE-induced ERK phosphorylation and HO-1 expression, but it only partly inhibited CAPE-induced Nrf2 accumulation and ARE promoter. Using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) method, the cellular antioxidant capacity of CAPE against 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)- or H2O2-induced oxidative stress also was shown to be partially suppressed by the ERK inhibitor. From the overall results it is proposed that the indirect antioxidant activity of CAPE against oxidative stress in HepG2 cells is partially attributed to induction of HO-1, which is regulated by Kelch-like erythroid-cell-derived protein with CNC homology (ECH)-associated protein 1 (Keap1)-independent Nrf2 activation relying on post-translational phosphorylation of ERK. PMID:25007817

  12. Short-duration intermittent hypoxia enhances endurance capacity by improving muscle fatty acid metabolism in mice.

    PubMed

    Suzuki, Junichi

    2016-04-01

    This study was designed to (1) investigate the effects of acute short-duration intermittent hypoxia on musclemRNAand microRNAexpression levels; and (2) clarify the mechanisms by which short-duration intermittent hypoxia improves endurance capacity. Experiment-1: Male mice were subjected to either acute 1-h hypoxia (12% O2), acute short-duration intermittent hypoxia (12% O2for 15 min, room air for 10 min, 4 times, Int-Hypo), or acute endurance exercise (Ex). The expression of vascular endothelial growth factor-AmRNAwas significantly greater than the control at 0 h post Ex and 6 h post Int-Hypo in the deep red region of the gastrocnemius muscle. miR-16 expression levels were significantly lower at 6 and 10 h post Int-Hypo. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)mRNAlevels were significantly greater than the control at 3 h post Ex and 6 h post Int-Hypo. miR-23a expression levels were lower than the control at 6-24 h post Int-Hypo. Experiment-2: Mice were subjected to normoxic exercise training with or without intermittent hypoxia for 3 weeks. Increases in maximal exercise capacity were significantly greater by training with short-duration intermittent hypoxia (IntTr) than without hypoxia. Both 3-Hydroxyacyl-CoA-dehydrogenase and total carnitine palmitoyl transferase activities were significantly enhanced in IntTr. Peroxisome proliferator-activated receptor delta andPGC-1α mRNAlevels were both significantly greater in IntTr than in the sedentary controls. These results suggest that exercise training under normoxic conditions with exposure to short-duration intermittent hypoxia represents a beneficial strategy for increasing endurance performance by enhancing fatty acid metabolism in skeletal muscle. PMID:27044851

  13. Acid Ceramidase (ASAH1) Is a Global Regulator of Steroidogenic Capacity and Adrenocortical Gene Expression

    PubMed Central

    Lucki, Natasha C.; Bandyopadhyay, Sibali; Wang, Elaine; Merrill, Alfred H.

    2012-01-01

    In H295R human adrenocortical cells, ACTH rapidly activates ceramide (Cer) and sphingosine (SPH) turnover with a concomitant increase in SPH-1-phosphate secretion. These bioactive lipids modulate adrenocortical steroidogenesis, primarily by acting as second messengers in the protein kinase A/cAMP-dependent pathway. Acid ceramidase (ASAH1) directly regulates the intracellular balance of Cer, SPH, and SPH-1-phosphate by catalyzing the hydrolysis of Cer into SPH. ACTH/cAMP signaling stimulates ASAH1 transcription and activity, supporting a role for this enzyme in glucocorticoid production. Here, the role of ASAH1 in regulating steroidogenic capacity was examined using a tetracycline-inducible ASAH1 short hairpin RNA H295R human adrenocortical stable cell line. We show that ASAH1 suppression increases the transcription of multiple steroidogenic genes, including Cytochrome P450 monooxygenase (CYP)17A1, CYP11B1/2, CYP21A2, steroidogenic acute regulatory protein, hormone-sensitive lipase, 18-kDa translocator protein, and the melanocortin-2 receptor. Induced gene expression positively correlated with enhanced histone H3 acetylation at target promoters. Repression of ASAH1 expression also induced the expression of members of the nuclear receptor nuclear receptor subfamily 4 (NR4A) family while concomitantly suppressing the expression of dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1. ASAH1 knockdown altered the expression of genes involved in sphingolipid metabolism and changed the cellular amounts of distinct sphingolipid species. Finally, ASAH1 silencing increased basal and cAMP-dependent cortisol and dehydroepiandrosterone secretion, establishing ASAH1 as a pivotal regulator of steroidogenic capacity in the human adrenal cortex. PMID:22261821

  14. High fat intake lowers hepatic fatty acid synthesis and raises fatty acid oxidation in aerobic muscle in Shetland ponies.

    PubMed

    Geelen, S N; Blázquez, C; Geelen, M J; Sloet van Oldruitenborgh-Oosterbaan, M M; Beynen, A C

    2001-07-01

    The metabolic effects of feeding soyabean oil instead of an isoenergetic amount of maize starch plus glucose were studied in ponies. Twelve adult Shetland ponies were given a control diet (15 g fat/kg DM) or a high-fat diet (118 g fat/kg DM) according to a parallel design. The diets were fed for 45 d. Plasma triacylglycerol (TAG) concentrations decreased by 55 % following fat supplementation. Fat feeding also reduced glycogen concentrations significantly by up to 65 % in masseter, gluteus and semitendinosus muscles (P < 0.05 and P < 0.01 and P < 0.01 respectively). The high-fat diet significantly increased the TAG content of semitendinosus muscle by 80 % (P < 0.05). Hepatic acetyl-CoA carboxylase and fatty acid synthase activities were 53 % (P < 0.01) and 56 % (P < 0.01) lower respectively in the high-fat group, but diacylglycerol acyltransferase activity was unaffected. Although carnitine palmitoyltransferase-I (CPT-I) activity in liver mitochondria was not influenced, fat supplementation did render CPT-I less sensitive to inhibition by malonyl-CoA. There was no significant effect of diet on the activity of phosphofructokinase in the different muscles. The activity of citrate synthase was raised significantly (by 25 %; P < 0.05) in the masseter muscle of fat-fed ponies, as was CPT-I activity (by 46 %; P < 0.01). We conclude that fat feeding enhances both the transport of fatty acids through the mitochondrial inner membrane and the oxidative capacity of highly-aerobic muscles. The higher oxidative ability together with the depressed rate of de novo fatty acid synthesis in liver may contribute to the dietary fat-induced decrease in plasma TAG concentrations in equines. PMID:11432762

  15. Phosphonic Acids for Interfacial Engineering of Transparent Conductive Oxides.

    PubMed

    Paniagua, Sergio A; Giordano, Anthony J; Smith, O'Neil L; Barlow, Stephen; Li, Hong; Armstrong, Neal R; Pemberton, Jeanne E; Brédas, Jean-Luc; Ginger, David; Marder, Seth R

    2016-06-22

    Transparent conducting oxides (TCOs), such as indium tin oxide and zinc oxide, play an important role as electrode materials in organic-semiconductor devices. The properties of the inorganic-organic interface-the offset between the TCO Fermi level and the relevant transport level, the extent to which the organic semiconductor can wet the oxide surface, and the influence of the surface on semiconductor morphology-significantly affect device performance. This review surveys the literature on TCO modification with phosphonic acids (PAs), which has increasingly been used to engineer these interfacial properties. The first part outlines the relevance of TCO surface modification to organic electronics, surveys methods for the synthesis of PAs, discusses the modes by which they can bind to TCO surfaces, and compares PAs to alternative organic surface modifiers. The next section discusses methods of PA monolayer deposition, the kinetics of monolayer formation, and structural evidence regarding molecular orientation on TCOs. The next sections discuss TCO work-function modification using PAs, tuning of TCO surface energy using PAs, and initiation of polymerizations from TCO-tethered PAs. Finally, studies that examine the use of PA-modified TCOs in organic light-emitting diodes and organic photovoltaics are compared. PMID:27227316

  16. Measurements of the acid-binding capacity of ingredients used in pig diets

    PubMed Central

    2005-01-01

    Some feed ingredients bind more acid in the stomach than others and for this reason may be best omitted from pig starter foods if gastric acidity is to be promoted. The objective of this study was to measure the acid-binding capacity (ABC) of ingredients commonly used in pig starter foods. Ingredients were categorised as follows: (i) milk products (n = 6), (ii) cereals (n = 10), (iii) root and pulp products (n = 5), (iv) vegetable proteins (n = 11), (v) meat and fish meal (n = 2), (vi) medication (n = 3), (vii) amino acids (n = 4), (viii) minerals (n = 16), (ix) acid salts (n = 4), (x) acids (n = 10). A 0.5 g sample of food was suspended in 50 ml distilled de-ionised water with continuous stirring. This suspension was titrated with 0.1 mol/L HCl or 0.1 mol/L NaOH so that approximately 10 additions of titrant was required to reach pH 3.0. The pH readings after each addition were recorded following equilibration for three minutes. ABC was calculated as the amount of acid in milliequivalents (meq) required to lower the pH of 1 kg food to (a) pH 4.0 (ABC-4) and (b) pH 3.0 (ABC-3). Categories of food had significantly different (P < 0.01) ABC values. Mean ABC-4 and ABC-3 values of the ten categories were: (i) 623 (s.d. 367.0) and 936 (s.d. 460.2), (ii) 142 (s.d. 79.2) and 324 (s.d. 146.4), (iii) 368 (s.d. 65.3) and 804 (s.d. 126.7), (iv) 381 (s.d. 186.1) and 746 (s.d. 227.0), (v) 749 (s.d. 211.6) and 1508 (s.d. 360.8), (vi) 120 (s.d. 95.6) and 261 (s.d. 163.2), (vii) 177 (s.d. 60.7) and 1078 (s.d. 359.0), (viii) 5064 (s.d. 5525.1) and 7051 (s.d. 5911.6), (ix) 5057 (s.d. 1336.6) and 8945 (s.d. 2654.1) and (x) -5883 (s.d. 4220.5) and -2591 (s.d. 2245.4) meq HCl per kg, respectively. Within category, ABC-3 and ABC- 4 values were highly correlated: R2 values of 0.80 and greater for food categories i, iv, v, vi, vii and viii. The correlation between predicted and observed ABC values of 34 mixed diets was 0.83 for ABC-4 and 0.71 for ABC-3. It was concluded that complete diets

  17. Preparation and characterization of a composite hydrogel with graphene oxide as an acid catalyst.

    PubMed

    Jiang, Ting; Sui, Zhu-Yin; Yang, Quan-Sheng; Zhang, Xuetong; Han, Bao-Hang

    2015-04-28

    In this study, a facile method for synthesizing a novel graphene oxide/pyrrole-formaldehyde (GOP-1) composite hydrogel was developed via in situ polymerization of pyrrole and formaldehyde in the presence of graphene oxide sheets without any additional catalyst. During the polymerization, graphene oxide can act as a two-dimensional template to regulate the aggregation state of polymer and as an acid catalyst to accelerate the reaction rate of pyrrole and formaldehyde. The morphology and microstructure were investigated by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction, respectively. The chemical properties were analyzed via X-ray photoelectron spectroscopy, infrared spectroscopy, and Raman spectroscopy. The freeze-dried GOP-1 composite hydrogel exhibited a large specific surface area, high nitrogen content, and three-dimensional network structure. Based on the above features, the freeze-dried GOP-1 composite hydrogel used as a gas adsorbent showed a high carbon dioxide uptake capacity at 1.0 bar and 273 K (11.1 wt%), in sharp contrast to that of graphene oxide (7.4 wt%). Furthermore, the as-prepared composite hydrogel may possess attractive potential in the fields of electrode material, tissue engineering, and water treatment. PMID:25760407

  18. Reactivation of a commercial diesel oxidation catalyst by acid washing.

    PubMed

    Galisteo, Francisco Cabello; Mariscal, Rafael; Granados, Manuel López; Fierro, José Luis García; Brettes, Pilar; Salas, Oscar

    2005-05-15

    The catalytic activity of samples taken from an oxidation catalyst mounted on diesel-driven automobiles and aged under road conditions was recovered to a significant extent by washing with a dilute solution of citric acid. The characterization of samples arising from a fresh, a vehicle-aged, and a regenerated catalyst was carried out by scanning electron microscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Relatively high levels of S and P, in the form of aluminum sulfate and phosphate, respectively, together with contaminant Si were detected in the used catalyst. Washing of the vehicle-aged catalytic oxidation converter revealed high efficiency in the extraction of the main contaminants detected (S and P) by this nondestructive methodology. The results of the experiments reported here should encourage the development of a technology based on this reactivation procedure for the rejuvenation of the catalytic device mounted on diesel exhaust pipes. PMID:15952394

  19. Influence of Amino Acid Compositions and Peptide Profiles on Antioxidant Capacities of Two Protein Hydrolysates from Skipjack Tuna (Katsuwonus pelamis) Dark Muscle.

    PubMed

    Chi, Chang-Feng; Hu, Fa-Yuan; Wang, Bin; Li, Zhong-Rui; Luo, Hong-Yu

    2015-05-01

    Influence of amino acid compositions and peptide profiles on antioxidant capacities of two protein hydrolysates from skipjack tuna (Katsuwonus pelamis) dark muscle was investigated. Dark muscles from skipjack tuna were hydrolyzed using five separate proteases, including pepsin, trypsin, Neutrase, papain and Alcalase. Two hydrolysates, ATH and NTH, prepared using Alcalase and Neutrase, respectively, showed the strongest antioxidant capacities and were further fractionated using ultrafiltration and gel filtration chromatography. Two fractions, Fr.A3 and Fr.B2, isolated from ATH and NTH, respectively, showed strong radical scavenging activities toward 2,2-diphenyl-1-picrylhydrazyl radicals (EC50 1.08% ± 0.08% and 0.98% ± 0.07%), hydroxyl radicals (EC50 0.22% ± 0.03% and 0.48% ± 0.05%), and superoxide anion radicals (EC50 1.31% ± 0.11% and 1.56% ± 1.03%) and effectively inhibited lipid peroxidation. Eighteen peptides from Fr.A3 and 13 peptides from Fr.B2 were isolated by reversed-phase high performance liquid chromatography, and their amino acid sequences were determined. The elevated antioxidant activity of Fr.A3 might be due to its high content of hydrophobic and aromatic amino acid residues (181.1 and 469.9 residues/1000 residues, respectively), small molecular sizes (3-6 peptides), low molecular weights (524.78 kDa), and amino acid sequences (antioxidant score 6.11). This study confirmed that a smaller molecular size, the presence of hydrophobic and aromatic amino acid residues, and the amino acid sequences were the key factors that determined the antioxidant activities of the proteins, hydrolysates and peptides. The results also demonstrated that the derived hydrolysates and fractions from skipjack tuna (K. pelamis) dark muscles could prevent oxidative reactions and might be useful for food preservation and medicinal purposes. PMID:25923316

  20. Influence of Amino Acid Compositions and Peptide Profiles on Antioxidant Capacities of Two Protein Hydrolysates from Skipjack Tuna (Katsuwonus pelamis) Dark Muscle

    PubMed Central

    Chi, Chang-Feng; Hu, Fa-Yuan; Wang, Bin; Li, Zhong-Rui; Luo, Hong-Yu

    2015-01-01

    Influence of amino acid compositions and peptide profiles on antioxidant capacities of two protein hydrolysates from skipjack tuna (Katsuwonus pelamis) dark muscle was investigated. Dark muscles from skipjack tuna were hydrolyzed using five separate proteases, including pepsin, trypsin, Neutrase, papain and Alcalase. Two hydrolysates, ATH and NTH, prepared using Alcalase and Neutrase, respectively, showed the strongest antioxidant capacities and were further fractionated using ultrafiltration and gel filtration chromatography. Two fractions, Fr.A3 and Fr.B2, isolated from ATH and NTH, respectively, showed strong radical scavenging activities toward 2,2-diphenyl-1-picrylhydrazyl radicals (EC50 1.08% ± 0.08% and 0.98% ± 0.07%), hydroxyl radicals (EC50 0.22% ± 0.03% and 0.48% ± 0.05%), and superoxide anion radicals (EC50 1.31% ± 0.11% and 1.56% ± 1.03%) and effectively inhibited lipid peroxidation. Eighteen peptides from Fr.A3 and 13 peptides from Fr.B2 were isolated by reversed-phase high performance liquid chromatography, and their amino acid sequences were determined. The elevated antioxidant activity of Fr.A3 might be due to its high content of hydrophobic and aromatic amino acid residues (181.1 and 469.9 residues/1000 residues, respectively), small molecular sizes (3–6 peptides), low molecular weights (524.78 kDa), and amino acid sequences (antioxidant score 6.11). This study confirmed that a smaller molecular size, the presence of hydrophobic and aromatic amino acid residues, and the amino acid sequences were the key factors that determined the antioxidant activities of the proteins, hydrolysates and peptides. The results also demonstrated that the derived hydrolysates and fractions from skipjack tuna (K. pelamis) dark muscles could prevent oxidative reactions and might be useful for food preservation and medicinal purposes. PMID:25923316

  1. Iron Photoreduction and Oxidation in an Acidic Mountain Stream

    NASA Astrophysics Data System (ADS)

    McKnight, D. M.; Kimball, B. A.; Bencala, K. E.

    1988-04-01

    In a small mountain stream in Colorado that receives acidic mine drainage, photoreduction of ferric iron results in a well-defined increase in dissolved ferrous iron during the day. To quantify this process, an instream injection of a conservative tracer was used to measure discharge at the time that each sample was collected. Daytime production of ferrous iron by photoreduction was almost four times as great as nighttime oxidation of ferrous iron. The photoreduction process probably involves dissolved or colloidal ferric iron species and limited interaction with organic species because concentrations of organic carbon are low in this stream.

  2. In situ electrocatalytic oxidation of acid violet 12 dye effluent.

    PubMed

    Mohan, N; Balasubramanian, N

    2006-08-21

    Electrochemical treatment of organic pollutants is a promising treatment technique for substances which are recalcitrant to biodegradation. Experiments were carried out to treat acid violet 12 dye house effluent using electrochemical technique for removal color and COD reduction covering wide range in operating conditions. Ruthenium/lead/tin oxide coated titanium and stainless steel were used as anode and cathode, respectively. The influence of effluent initial concentration, pH, supporting electrolyte and the electrode material on rate of degradation has been critically examined. The results indicate that the electrochemical method can be used to treat dye house effluents. PMID:16730894

  3. Low molecular weight carboxylic acids in oxidizing porphyry copper tailings.

    PubMed

    Dold, Bernhard; Blowes, David W; Dickhout, Ralph; Spangenberg, Jorge E; Pfeifer, Hans-Rudolf

    2005-04-15

    The distribution of low molecular weight carboxylic acids (LMWCA) was investigated in pore water profiles from two porphyry copper tailings impoundments in Chile (Piuquenes at La Andina and Cauquenes at El Teniente mine). The objectives of this study were (1) to determine the distribution of LMWCA, which are interpreted to be the metabolic byproducts of the autotroph microbial community in this low organic carbon system, and (2) to infer the potential role of these acids in cycling of Fe and other elements in the tailings impoundments. The speciation and mobility of iron, and potential for the release of H+ via hydrolysis of the ferric iron, are key factors in the formation of acid mine drainage in sulfidic mine wastes. In the low-pH oxidation zone of the Piuquenes tailings, Fe(III) is the dominant iron species and shows high mobility. LMWCA, which occur mainly between the oxidation front down to 300 cm below the tailings surface at both locations (e.g., max concentrations of 0.12 mmol/L formate, 0.17 mmol/L acetate, and 0.01 mmol/L pyruvate at Piuquenes and 0.14 mmol/L formate, 0.14 mmol/L acetate, and 0.006 mmol/L pyruvate at Cauquenes), are observed at the same location as high Fe concentrations (up to 71.2 mmol/L Fe(II) and 16.1 mmol/L Fe(III), respectively). In this zone, secondary Fe(III) hydroxides are depleted. Our data suggest that LMWCA may influence the mobility of iron in two ways. First, complexation of Fe(III), through formation of bidentate Fe(III)-LMWCA complexes (e.g., pyruvate, oxalate), may enhance the dissolution of Fe(III) (oxy)hydroxides or may prevent precipitation of Fe(III) (oxy)hydroxides. Soluble Fe(III) chelate complexes which may be mobilized downward and convert to Fe(II) by Fe(III) reducing bacteria. Second, monodentate LMWCA (e.g., acetate and formate) can be used by iron-reducing bacteria as electron donors (e.g., Acidophilum spp.), with ferric iron as the electron acceptor. These processes may, in part, explain the low abundances

  4. Co-oxidation of the sulfur-containing amino acids in an autoxidizing lipid system

    USGS Publications Warehouse

    Wedemeyer, G.A.; Dollar, A.M.

    1963-01-01

    Oxidation of the sulfur amino acids by autoxidizing lipids was studied in a model system consisting of an amino acid dispersed in cold-pressed, molecularly distilled menhaden oil (20–80% w/w). Under all conditions investigated, cysteine was oxidized completely to cystine. Preliminary results suggest that at 110°C the oxidation follows first-order kinetics for at least the first 8 hr. A specific reaction rate constant of 0.25 per hour was calculated. When fatty acids were added to the system, cystine was oxidized to its thiosulfinate ester. When the fatty acid-cystine ratio was 1:2, oxidation of cystine was a maximum. No oxidation of cystine occurred unless either a fatty acid, volatile organic acid, or ethanol was added. Under the conditions investigated, methionine was not oxidized to either its sulfoxide or its sulfone.

  5. Impact of trolox, quercetin, genistein and gallic acid on the oxidative damage to myofibrillar proteins: the carbonylation pathway.

    PubMed

    Utrera, Mariana; Estévez, Mario

    2013-12-15

    The carbonylation pathway involves the oxidative deamination of lysine residues to yield a carbonyl compound (α-aminoadipic semialdehyde) that can be further oxidised to α-aminoadipic acid and form Schiff bases structures. The effect of trolox and other phenolic compounds (PhC) (namely genistein, quercetin and gallic acid) on the protein carbonylation pathway occurred during the oxidation of myofibrillar proteins (MP) catalysed by a Fe(3+)/H2O2 system was studied. Trolox and PhC can exert either antioxidant or pro-oxidant capacities depending on their concentration, the oxidation conditions and the target in proteins. In general, quercetin and genistein showed an antioxidant activity towards lipid oxidation and the carbonylation pathway at different concentrations under the analysed conditions. Plausible mechanisms for the antioxidant and pro-oxidant effects of trolox and PhC on MP are discussed. Further research is needed to shed light on the effect of PhC mixtures on both lipid and protein oxidation. PMID:23993577

  6. 40 CFR 721.10529 - Cobalt iron manganese oxide, carboxylic acid-modified (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Cobalt iron manganese oxide... Significant New Uses for Specific Chemical Substances § 721.10529 Cobalt iron manganese oxide, carboxylic acid... substance identified generically as cobalt iron manganese oxide, carboxylic acid-modified (PMN P-12-35)...

  7. 40 CFR 721.10529 - Cobalt iron manganese oxide, carboxylic acid-modified (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Cobalt iron manganese oxide... Significant New Uses for Specific Chemical Substances § 721.10529 Cobalt iron manganese oxide, carboxylic acid... substance identified generically as cobalt iron manganese oxide, carboxylic acid-modified (PMN P-12-35)...

  8. Ditetraalkylammonium amino acid ionic liquids as CO₂ absorbents of high capacity.

    PubMed

    Ma, Jing-Wen; Zhou, Zheng; Zhang, Feng; Fang, Cheng-Gang; Wu, You-Ting; Zhang, Zhi-Bing; Li, Ai-Min

    2011-12-15

    By grafting butyl or ethyl onto tetramethylethylenediamine, quaternary ammonium salts with two positive charge centers were formed at the first step. Metathesis with Ag(2)O followed. Through neutralization with glycine, l-alanine, or valine, a series of new ditetraalkylammonium amino acid ionic liquids (DILs) for CO(2) capture were generated. The structures of DILs, as shown in Figure 1, were verified by using (1)H NMR and EA. These DILs were found to be of quite high viscosity which militated against their industrial application in CO(2) removal. Drawing on the experience of mixed amines' aqueous solutions, these DILs were blended with water or N-methyldiethanolamine (MDEA) aqueous solutions to act as special absorbents of CO(2). Using a Double-Tank Absorption System, the absorption performance of these DIL solutions was investigated in detail. The experimental results indicated that among the three aqueous solutions of DILs (20%, 40%, and 80 wt %), the solution of 40% DIL had a higher absorption rate of CO(2) than the other two, demonstrating the different effects of concentration and viscosity on the absorption. The solution of 40% DIL or the 15% DIL + 15% MDEA had much higher capacity for CO(2) than the corresponding monocation tetraalkylammonium AAILs, due to the special structure of the dication which could influence the solubility of CO(2) in the aqueous solution. PMID:22066493

  9. Combined defects in oxidative phosphorylation and fatty acid β-oxidation in mitochondrial disease

    PubMed Central

    Nsiah-Sefaa, Abena; McKenzie, Matthew

    2016-01-01

    Mitochondria provide the main source of energy to eukaryotic cells, oxidizing fats and sugars to generate ATP. Mitochondrial fatty acid β-oxidation (FAO) and oxidative phosphorylation (OXPHOS) are two metabolic pathways which are central to this process. Defects in these pathways can result in diseases of the brain, skeletal muscle, heart and liver, affecting approximately 1 in 5000 live births. There are no effective therapies for these disorders, with quality of life severely reduced for most patients. The pathology underlying many aspects of these diseases is not well understood; for example, it is not clear why some patients with primary FAO deficiencies exhibit secondary OXPHOS defects. However, recent findings suggest that physical interactions exist between FAO and OXPHOS proteins, and that these interactions are critical for both FAO and OXPHOS function. Here, we review our current understanding of the interactions between FAO and OXPHOS proteins and how defects in these two metabolic pathways contribute to mitochondrial disease pathogenesis. PMID:26839416

  10. Techno-functional properties and in vitro bile acid-binding capacities of tamarillo (Solanum betaceum Cav.) hydrocolloids.

    PubMed

    Gannasin, Sri Puvanesvari; Adzahan, Noranizan Mohd; Mustafa, Shuhaimi; Muhammad, Kharidah

    2016-04-01

    Hydrocolloids were extracted from seed mucilage and the pulp fractions from red tamarillo (Solanum betaceum Cav.) mesocarp, and characterisation of their techno-functional properties and in vitro bile acid-binding capacities was performed. The seed mucilage hydrocolloids that were extracted, using either 1% citric acid (THC) or water (THW), had a good foaming capacity (32-36%), whereas the pulp hydrocolloids that were extracted, using 72% ethanol (THE) or 20mM HEPES buffer (THH), had no foaming capacity. The pulp hydrocolloid, however, possessed high oil-holding and water-holding capacities in the range of 3.3-3.6 g oil/g dry sample and 25-27 g water/g dry sample, respectively. This enabled the pulp hydrocolloid to entrap more bile acids (35-38% at a hydrocolloid concentration of 2%) in its gelatinous network in comparison to commercial oat fibre and other hydrocolloids studied. The exceptional emulsifying properties (80-96%) of both hydrocolloids suggest their potential applications as food emulsifiers and bile acid binders. PMID:26593571

  11. Effects of trimetazidine in ethanol- and acetic acid-induced colitis: oxidant/anti-oxidant status.

    PubMed

    Girgin; Karaoglu; Tüzün; Erkus; Ozütemiz; Dinçer; Batur; Tanyalçin

    1999-11-01

    There is overwhelming evidence in favour of a significant role of reactive oxygen metabolites (ROM) in the pathophysiology of inflammatory bowel disease (IBD) in man and in experimental animal models. This study was undertaken to investigate the possible protective effects of pretreatment with trimetazidine (TMZ) on the oxidant-anti-oxidant balance in ethanol- and acetic acid-induced colonic damage in rats. TMZ was chosen because of its various cytoprotective features (preserving cellular ATP levels, limiting intracellular acidosis and limiting inorganic phosphate, Na(+) and Ca(2+) accumulation) and anti-oxy characteristics which were previously reported. A total of 80 rats were randomized into eight major groups each consisting of 10 animals. Animals in groups 1, 2 and 3 served as models of ethanol-induced colitis (0.25 ml of 30% (v/v) ethanol), while group 4 served as their control. Animals in groups 5, 6 and 7 served as models of acetic acid-induced colitis (1 ml of 4% (v/v) acetic acid), while group 8 served as their control. TMZ was administered 5 mg/kg by intrarectal (i.r.) and intraperitoneal (i.p.) routes to groups 1, 2, 5 and 6. Intraperitoneal administration of TMZ was used in order to evaluate its systemic effect while i.r. administration was used to determine its local effect. After decapitation, colon mucosa samples were obtained and evaluated macroscopically and microscopically. Myeloperoxidase (MPO) activities as markers for inflammation, malondialdehyde (MDA) levels as markers for oxidant stress and reduced glutathione (GSH) and oxidized glutathione (GSSG) levels as markers for anti-oxidant status were determined. Acute colitis was observed in macroscopic and microscopic evaluation in ethanol- and acetic acid-administered groups compared with controls (P = 0.000). The macroscopic and microscopic scores in colitis groups were correlated with MPO activities (r = 0.5365, P = 0.000 and r = 0.5499, P = 0.000, respectively). MDA

  12. Evaluating the Capacity to Generate and Preserve Nitric Oxide Bioactivity in Highly Purified Earthworm Erythrocruorin

    PubMed Central

    Roche, Camille J.; Talwar, Abhinav; Palmer, Andre F.; Cabrales, Pedro; Gerfen, Gary; Friedman, Joel M.

    2015-01-01

    The giant extracellular hemoglobin (erythrocruorin) from the earth worm (Lumbricus terrestris) has shown promise as a potential hemoglobin-based oxygen carrier (HBOC) in in vivo animal studies. An important beneficial characteristic of this hemoglobin (LtHb) is the large number of heme-based oxygen transport sites that helps overcome issues of osmotic stress when attempting to provide enough material for efficient oxygen delivery. A potentially important additional property is the capacity of the HBOC either to generate nitric oxide (NO) or to preserve NO bioactivity to compensate for decreased levels of NO in the circulation. The present study compares the NO-generating and NO bioactivity-preserving capability of LtHb with that of human adult hemoglobin (HbA) through several reactions including the nitrite reductase, reductive nitrosylation, and still controversial nitrite anhydrase reactions. An assignment of a heme-bound dinitrogen trioxide as the stable intermediate associated with the nitrite anhydrase reaction in both LtHb and HbA is supported based on functional and EPR spectroscopic studies. The role of the redox potential as a factor contributing to the NO-generating activity of these two proteins is evaluated. The results show that LtHb undergoes the same reactions as HbA and that the reduced efficacy for these reactions for LtHb relative to HbA is consistent with the much higher redox potential of LtHb. Evidence of functional heterogeneity in LtHb is explained in terms of the large difference in the redox potential of the isolated subunits. PMID:25371199

  13. Seasonal dependence of the oxidation capacity of the city of Santiago de Chile

    NASA Astrophysics Data System (ADS)

    Elshorbany, Y. F.; Kleffmann, J.; Kurtenbach, R.; Lissi, E.; Rubio, M.; Villena, G.; Gramsch, E.; Rickard, A. R.; Pilling, M. J.; Wiesen, P.

    2010-12-01

    The oxidation capacity of the highly polluted urban area of Santiago de Chile has been evaluated during a winter measurement campaign from May 25 to June 07, 2005, with the results compared and contrasted with those previously evaluated during a summer campaign from March 8 to 20, 2005. The OH radical budget was evaluated in both campaigns employing a simple quasi-photostationary state model (PSS) constrained with simultaneous measurements of HONO, HCHO, O 3, NO, NO 2, j(O 1D), j(NO 2), 13 alkenes and meteorological parameters. In addition, a zero dimensional photochemical box model based on the Master Chemical Mechanism (MCMv3.1) has been used for the analysis of the radical budgets and concentrations of OH, HO 2 and RO 2. Besides the above parameters, the MCM model has been constrained by the measured CO and other volatile organic compounds (VOCs) including alkanes and aromatics. Total production and destruction rates of OH and HO 2 in winter are about two times lower than that during summer. Simulated OH levels by both PSS and MCM models are similar during the daytime for both winter and summer indicating that the primary OH sources and sinks included in the simple PSS model are predominant. On a 24 h basis, HONO photolysis was shown to be the most important primary OH radical source comprising 81% and 52% of the OH initiation rate during winter and summer, respectively followed by alkene ozonolysis (12.5% and 29%), photolysis of HCHO (6.1% and 15%), and photolysis of O 3 (<1% and 4%), respectively. During both winter and summer, there was a balance between the OH secondary production (HO 2 + NO) and destruction (OH + VOCs) showing that initiation sources of RO 2 and HO 2 are no net OH initiation sources. This result was found to be fulfilled also for all other studies investigated. Seasonal impacts on the radical budgets are also discussed.

  14. Arsenate removal with 3-mercaptopropanoic acid-coated superparamagnetic iron oxide nanoparticles.

    PubMed

    Morillo, D; Uheida, A; Pérez, G; Muhammed, M; Valiente, M

    2015-01-15

    In the present work, superparamagnetic iron oxide nanoparticles (SPION) surface-coated with 3-mercaptopropanoic acid (3-MPA) were prepared and their feasibility for the removal of arsenate from dilute aqueous solutions was demonstrated. The synthesized 3-MPA-coated SPION was characterized using transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infra-red spectrometry (FTIR). Separation efficiency of the coated nanoparticles and the equilibrium isotherm of arsenate adsorption were investigated. The obtained results reveal the arsenate adsorption to be highly pH-dependent, and the maximum adsorption was attained in less than 60 min. The resulting increase of 3-MPA-coated SPION adsorption capacity to twice the adsorption capacity of SPION alone under the same conditions is attributed to the increase of active adsorption sites. An adsorption reaction is proposed. On the other hand, efficient recovery of arsenate from the loaded nanoparticles was achieved using nitric acid (HNO3) solution, which also provides a concentration over the original arsenate solution. PMID:25454446

  15. Fluorine-Doped Tin Oxide Nanocrystal/Reduced Graphene Oxide Composites as Lithium Ion Battery Anode Material with High Capacity and Cycling Stability.

    PubMed

    Xu, Haiping; Shi, Liyi; Wang, Zhuyi; Liu, Jia; Zhu, Jiefang; Zhao, Yin; Zhang, Meihong; Yuan, Shuai

    2015-12-16

    Tin oxide (SnO2) is a kind of anode material with high theoretical capacity. However, the volume expansion and fast capability fading during cycling have prevented its practical application in lithium ion batteries. Herein, we report that the nanocomposite of fluorine-doped tin oxide (FTO) and reduced graphene oxide (RGO) is an ideal anode material with high capacity, high rate capability, and high stability. The FTO conductive nanocrystals were successfully anchored on RGO nanosheets from an FTO nanocrystals colloid and RGO suspension by hydrothermal treatment. As the anode material, the FTO/RGO composite showed high structural stability during the lithiation and delithiation processes. The conductive FTO nanocrystals favor the formation of stable and thin solid electrolyte interface films. Significantly, the FTO/RGO composite retains a discharge capacity as high as 1439 mAhg(-1) after 200 cycles at a current density of 100 mAg(-1). Moreover, its rate capacity displays 1148 mAhg(-1) at a current density of 1000 mAg(-1). PMID:26606370

  16. A novel method for the determination of ascorbic acid and antioxidant capacity in Opuntia ficus indica using in vivo microdialysis.

    PubMed

    Pretti, L; Bazzu, G; Serra, P A; Nieddu, G

    2014-03-15

    A simple and rapid method was developed for in vivo simultaneous determination of ascorbic-acid and antioxidant capacity in microdialysates from cladodes of Opuntia ficus-indica (L.) Miller. The method is verified in water-stressed plants, as compared with a well-watered test controls. The microdialysis probe construction and insertion procedure was specifically developed to minimise the tissue trauma of the plant and to obtain optimal dialysis performance. Microdialysis was performed using a flow rate of 3 μL/min and the samples were analysed by HPLC coupled to electrochemical detection of ascorbic-acid and DPPH-determined antioxidant capacity. Our data indicate exponential decay of the concentrations of the analysed compounds as a function of microdialysis sampling time. Water-stressed Opuntia show decreased ascorbic acid levels and increased the others antioxidants. PMID:24206696

  17. Genetic Variation of Fatty Acid Oxidation and Obesity, A Literature Review

    PubMed Central

    Freitag Luglio, Harry

    2016-01-01

    Modulation of fat metabolism is an important component of the etiology of obesity as well as individual response to weight loss program. The influence of lipolysis process had receives many attentions in recent decades. Compared to that, fatty acid oxidation which occurred after lipolysis seems to be less exposed. There are limited publications on how fatty acid oxidation influences predisposition to obesity, especially the importance of genetic variations of fatty acid oxidation proteins on development of obesity. The aim of this review is to provide recent knowledge on how polymorphism of genes related fatty acid oxidation is obtained. Studies in human as well as animal model showed that disturbance of genes related fatty acid oxidation process gave impact on body weight and risks to obesity. Several polymorphisms on CD36, CPT, ACS and FABP had been shown to be related to obesity either by regulating enzymatic activity or directly influence fatty acid oxidation process. PMID:27127449

  18. The relationship of nitric oxide synthesis capacity, oxidative stress, and albumin-to-creatinine ratio in black and white men: the SABPA study.

    PubMed

    Mels, Catharina M C; Huisman, Hugo W; Smith, Wayne; Schutte, Rudolph; Schwedhelm, Edzard; Atzler, Dorothee; Böger, Rainer H; Ware, Lisa J; Schutte, Aletta E

    2016-02-01

    Inadequate substrate availability and increased nitric oxide synthase inhibitor levels attenuate nitric oxide (NO) synthesis, whereas increased vascular oxidative stress may lead to inactivation of NO. We compared markers of NO synthesis capacity and oxidative stress in a bi-ethnic male population. Inter-relationships of ambulatory blood pressure and urinary albumin-to-creatinine ratio with NO synthesis capacity and oxidative stress markers were investigated. NO synthesis capacity markers (L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA)) and oxidative stress markers (serum peroxides, total glutathione, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), and catalase) were measured. Black men displayed higher blood pressure and albumin-to-creatinine ratio (all p < 0.001), while NO synthesis capacity was more favorable (higher L-arginine and lower ADMA (p ≤ 0.003)). Antioxidant enzyme activities were similar except for the redox status markers (GR activity and GR/GPx ratio), which were upregulated in black men (p < 0.001). In black men, ADMA was inversely related to GPx activity (R (2) = 0.15; β = -0.20; p = 0.050) and GPx/SOD ratio (R (2) = 0.24; β = -0.37; p < 0.001), but none of these markers related to blood pressure or albumin-to-creatinine ratio. In white men, albumin-to-creatinine ratio was positively associated with ADMA (R (2) = 0.18; β = 0.39; p < 0.001) while ADMA was inversely related to GR activity (R (2) = 0.26; β = -0.29; p = 0.002) and GR/GPx ratio (R (2) = 0.25; β = -0.28; p = 0.003). Black men with elevated blood pressure and albumin-to-creatinine ratio displayed a favorable NO synthesis capacity. This may be counteracted by increased inactivation of NO, although it was not linked to vascular or renal phenotypes. In white men, reduced NO synthesis capacity may lower NO bio-availability, thereby influencing the albumin

  19. Lewis acid catalysis and Green oxidations: sequential tandem oxidation processes induced by Mn-hyperaccumulating plants.

    PubMed

    Escande, Vincent; Renard, Brice-Loïc; Grison, Claude

    2015-04-01

    Among the phytotechnologies used for the reclamation of degraded mining sites, phytoextraction aims to diminish the concentration of polluting elements in contaminated soils. However, the biomass resulting from the phytoextraction processes (highly enriched in polluting elements) is too often considered as a problematic waste. The manganese-enriched biomass derived from native Mn-hyperaccumulating plants of New Caledonia was presented here as a valuable source of metallic elements of high interest in chemical catalysis. The preparation of the catalyst Eco-Mn1 and reagent Eco-Mn2 derived from Grevillea exul exul and Grevillea exul rubiginosa was investigated. Their unusual polymetallic compositions allowed to explore new reactivity of low oxidative state of manganese-Mn(II) for Eco-Mn1 and Mn(IV) for Eco-Mn2. Eco-Mn1 was used as a Lewis acid to catalyze the acetalization/elimination of aldehydes into enol ethers with high yields; a new green and stereoselective synthesis of (-)-isopulegol via the carbonyl-ene cyclization of (+)-citronellal was also performed with Eco-Mn1. Eco-Mn2 was used as a mild oxidative reagent and controlled the oxidation of aliphatic alcohols into aldehydes with quantitative yields. Oxidative cleavage was interestingly noticed when Eco-Mn2 was used in the presence of a polyol. Eco-Mn2 allowed direct oxidative iodination of ketones without using iodine, which is strongly discouraged by new environmental legislations. Finally, the combination of the properties in the Eco-Mn catalysts and reagents gave them an unprecedented potential to perform sequential tandem oxidation processes through new green syntheses of p-cymene from (-)-isopulegol and (+)-citronellal; and a new green synthesis of functionalized pyridines by in situ oxidation of 1,4-dihydropyridines. PMID:25263417

  20. Comparative Oxidative Stability of Fatty Acid Alkyl Esters by Accelerated Methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several fatty acid alkyl esters were subjected to accelerated methods of oxidation, including EN 14112 (Rancimat method) and pressurized differential scanning calorimetry (PDSC). Structural trends elucidated from both methods that improved oxidative stability included decreasing the number of doubl...

  1. Respiratory and eye irritation from boron oxide and boric acid dusts

    SciTech Connect

    Garabrant, D.H.; Bernstein, L.; Peters, J.M.; Smith, T.J.

    1984-08-01

    Boron oxide has been shown in animals to irritate the respiratory mucosa and conjuctiva. The present study was undertaken to determine whether exposures to boron oxide and its hydration product, boric acid, cau

  2. Characterization of phosphonic acid binding to zinc oxide

    SciTech Connect

    Hotchkiss, Peter J.; Malicki, Michał; Giordano, Anthony J.; Armstrong, Neal R.; Marder, Seth R.

    2011-01-24

    Radio Frequency (RF) sputter-deposited zinc oxide (ZnO) films have been modified with alkylphosphonic acids in order to study both the binding of the phosphonic acid (PA) group to the ZnO surface and the packing of the alkyl chain. The characterization of these PA-modified ZnO substrates by X-ray photoelectron spectroscopy (XPS), infrared reflection-absorption spectroscopy (IRRAS), atomic force microscopy (AFM) and contact angle measurements is presented herein. The surface modification procedure is straightforward and was adapted from earlier work. XPS analysis shows that oxygen plasma (OP) treatment creates reactive oxygen species on the surface of ZnO, allowing for a more robust binding of PAs to the ZnO surface. IRRAS analysis indicates that octadecylphosphonic acid binds to the ZnO surface in a predominantly tridentate fashion, forming dense, well-packed monolayers with alkyl chains in a fully anti-conformation. AFM and contact angle measurements indicate good surface coverage of the PAs with little to no multilayer formation.

  3. Lack of phosphatidylethanolamine N-methyltransferase in mice does not promote fatty acid oxidation in skeletal muscle.

    PubMed

    Tasseva, Guergana; van der Veen, Jelske N; Lingrell, Susanne; Jacobs, René L; Vance, Dennis E; Vance, Jean E

    2016-02-01

    Phosphatidylethanolamine N-methyltransferase (PEMT) converts phosphatidylethanolamine (PE) to phosphatidylcholine (PC) in the liver. Mice lacking PEMT are protected from high-fat diet-induced obesity and insulin resistance, and exhibit increased whole-body energy expenditure and oxygen consumption. Since skeletal muscle is a major site of fatty acid oxidation and energy utilization, we determined if rates of fatty acid oxidation/oxygen consumption in muscle are higher in Pemt(-/-) mice than in Pemt(+/+) mice. Although PEMT is abundant in the liver, PEMT protein and activity were undetectable in four types of skeletal muscle. Moreover, amounts of PC and PE in the skeletal muscle were not altered by PEMT deficiency. Thus, we concluded that any influence of PEMT deficiency on skeletal muscle would be an indirect consequence of lack of PEMT in liver. Neither the in vivo rate of fatty acid uptake by muscle nor the rate of fatty acid oxidation in muscle explants and cultured myocytes depended upon Pemt genotype. Nor did PEMT deficiency increase oxygen consumption or respiratory function in skeletal muscle mitochondria. Thus, the increased whole body oxygen consumption in Pemt(-/-) mice, and resistance of these mice to diet-induced weight gain, are not primarily due to increased capacity of skeletal muscle for utilization of fatty acids as an energy source. PMID:26603903

  4. Catalytic air oxidation of biomass-derived carbohydrates to formic acid.

    PubMed

    Li, Jiang; Ding, Dao-Jun; Deng, Li; Guo, Qing-Xiang; Fu, Yao

    2012-07-01

    An efficient catalytic system for biomass oxidation to form formic acid was developed. The conversion of glucose to formic acid can reach up to 52% yield within 3 h when catalyzed by 5 mol% of H(5)PV(2)Mo(10)O(40) at only 373 K using air as the oxidant. Furthermore, the heteropolyacid can be used as a bifunctional catalyst in the conversion of cellulose to formic acid (yield=35%) with air as the oxidant. PMID:22499553

  5. Gallic acid decreases hepatitis C virus expression through its antioxidant capacity

    PubMed Central

    GOVEA-SALAS, MAYELA; RIVAS-ESTILLA, ANA MARIA; RODRÍGUEZ-HERRERA, RAUL; LOZANO-SEPÚLVEDA, SONIA A.; AGUILAR-GONZALEZ, CRISTOBAL N.; ZUGASTI-CRUZ, ALEJANDRO; SALAS-VILLALOBOS, TANYA B.; MORLETT-CHÁVEZ, JESUS ANTONIO

    2016-01-01

    Gallic acid (GA) is a natural phenolic compound that possesses various biological effects, including antioxidant, anti-inflammatory, antibiotic, anticancer, antiviral and cardiovascular protection activities. In addition, numerous studies have reported that antioxidants possess antiviral activities. Hepatitis C virus (HCV) is one of the most important causes of chronic liver diseases worldwide, but until recently, only a small number of antiviral agents had been developed against HCV. Therefore, the present study investigated whether GA exhibits an anti-HCV activity. The effects of GA on HCV expression were examined using a subgenomic HCV replicon cell culture system that expressed HCV nonstructural proteins (NSs). In addition, GA cytotoxicity was evaluated at concentrations between 100–600 mg/ml using an MTT assay. Huh-7 replicon cells were incubated with 300 mg/ml GA for different times, and the HCV-RNA and protein levels were measured by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Pyrrolidine dithiocarbamate (PDTC) was used as an antioxidant control and reactive oxygen species (ROS) production was measured during the exposure. The results indicated that GA did not produce a statistically significant cytotoxicity in parental and HCV replicon cells. Furthermore, GA downregulated the expression levels of NS5A-HCV protein (~55%) and HCV-RNA (~50%) in a time-dependent manner compared with the levels in untreated cells. Notably, GA treatment decreased ROS production at the early time points of exposure in cells expressing HCV proteins. Similar results were obtained upon PDTC exposure. These findings suggest that the antioxidant capacity of GA may be involved in the downregulation of HCV replication in hepatoma cells. PMID:26893656

  6. Interaction of polyacrylic acid coated and non-coated iron oxide nanoparticles with human neutrophils.

    PubMed

    Couto, Diana; Freitas, Marisa; Vilas-Boas, Vânia; Dias, Irene; Porto, Graça; Lopez-Quintela, M Arturo; Rivas, José; Freitas, Paulo; Carvalho, Félix; Fernandes, Eduarda

    2014-02-10

    Iron oxide nanoparticles (ION), with different coatings and sizes, have attracted extensive interest in the last years to be applied in drug delivery, cancer therapy and as contrast agents in imagiologic techniques such as magnetic resonance imaging. However, the safety of these nanoparticles is still not completely established, particularly to host defense systems that are usually recruited for their clearance from the body. In this paper, given the importance of neutrophils in the immune response of the organism to nanoparticles, the effect of polyacrylic acid (PAA)-coated and non-coated ION on human neutrophils was evaluated in vitro, namely their capacity to activate the oxidative burst and to modify their lifespan. The obtained results showed that the studied PAA-coated and non-coated ION triggered neutrophils' oxidative burst in a NADPH oxidase dependent manner, and that PAA-coated ION increased - while non-coated ION prevented - apoptotic signaling and apoptosis. These effects may have important clinical implications in biomedical applications of ION. PMID:24291037

  7. Evaluation of oxidant-antioxidant balance and total antioxidant capacity of serum in children with urinary tract infection

    PubMed Central

    Soleimani, Gholamreza; Sadeghi-Bojd, Simin; Teimouri, Alireza; Nakhaee, Alireza; Sheikhhosseini, Alireza

    2016-01-01

    Background: Urinary tract infection (UTI) is the most common bacterial infections in children. This studyaimed to investigate the oxidative and antioxidate status of plasma in patients with UTI and to compare them with those of the controls. Methods: This case–control study of 50–75 children in the given order was performed in 2013 at the Pediatric Clinic of infections in Zahedan Hospital of Ali Ibn Abi Talib. The antioxidative status of plasma were evaluated by measuring the total antioxidant capacity (TAC) The oxidative status of samples was assessed by measuring the total peroxide and the oxidative stress index (OSI) levels. The means of the parameters were compared and the relationship among them was determined. Data were analyzed using SPSS 20 (IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp). Student's t-test and Mann–Whitney U-test were applied in various situations of our questions; 95% confidence interval was considered for the level of significance. Results: The results showed that total oxidant serum status in UTI patients was higher compared to controls when total antioxidant serum was lower. The balance of oxidant-antioxidant serum was in favor of oxidant serum and this term was confirmed by OSI. Conclusion: Our results showed that the plasma levels of TAC in patients with UTI were decreased compared to controls, and oxidant-antioxidant balance and OSI caused increased OS in patients. PMID:27226686

  8. Effects of standtime on the available capacity of lead-acid and nickel/iron electric vehicle batteries

    SciTech Connect

    DeLuca, W.H.; Tummillo, A.F.; Biwer, R.L.; Yao, N.P.

    1984-01-01

    In electric vehicle (EV) applications, the battery load typically contains interruptions of various time durations. These standtimes affect the battery's available capacity and must be understood in order to predict and optimize vehicle operation. Laboratory tests were conducted to measure the impact of various standtimes (0-4 h) at different depth-of-discharge (DOD) and state-of-charge (SOC) levels on the capacity retention of both improved lead-acid and nickel/iron (Ni/Fe) EV batteries. The results showed that the Ni/Fe system exhibits a self-discharge capacity loss immediately after charging that increases with both standtime and SOC. Fortunately, the self-discharge rate decreases rapidly with standtime and discharging. Standtimes after charging also decrease the available capacity of the lead-acid system due to reduced battery temperatures. However, standtimes at DOD levels > 50% provide an increase in battery capacity by allowing for the relaxation of electrolyte concentration gradients. This paper describes the test procedures used, presents the test data, and discusses the results.

  9. Age-related changes in oxidative capacity differ between locomotory muscles and are associated with physical activity behavior

    PubMed Central

    Larsen, Ryan G.; Callahan, Damien M.; Foulis, Stephen A.; Kent-Braun, Jane A.

    2013-01-01

    There is discrepancy in the literature regarding the degree to which old age affects muscle bioenergetics. These discrepancies are likely influenced by several factors, including variations in physical activity (PA) and differences in the muscle group investigated. To test the hypothesis that age may affect muscles differently, we quantified oxidative capacity of tibialis anterior (TA) and vastus lateralis (VL) muscles in healthy, relatively sedentary younger (8 YW, 8 YM; 21–35 years) and older (8 OW, 8 OM; 65–80 years) adults. To investigate the effect of physical activity on muscle oxidative capacity in older adults, we compared older sedentary women to older women with mild-to-moderate mobility impairment and lower physical activity (OIW, n = 7), and older sedentary men with older active male runners (OAM, n = 6). Oxidative capacity was measured in vivo as the rate constant, kPCr, of postcontraction phosphocreatine recovery, obtained by 31P magnetic resonance spectroscopy following maximal isometric contractions. While kPCr was higher in TA of older than activity-matched younger adults (28%; p = 0.03), older adults had lower kPCr in VL (23%; p = 0.04). In OIW compared with OW, kPCr was lower in VL (~45%; p = 0.01), but not different in TA. In contrast, OAM had higher kPCr than OM (p = 0.03) in both TA (41%) and VL (54%). In older adults, moderate-to-vigorous PA was positively associated with kPCr in VL (r = 0.65, p < 0.001) and TA (r = 0.41, p = 0.03). Collectively, these results indicate that age-related changes in oxidative capacity vary markedly between locomotory muscles, and that altered PA behavior may play a role in these changes. PMID:22236246

  10. Fatty Acid Composition as a Predictor for the Oxidation Stability of Korean Vegetable Oils with or without Induced Oxidative Stress

    PubMed Central

    Yun, Jung-Mi; Surh, Jeonghee

    2012-01-01

    This study was designed to investigate whether the fatty acid composition could make a significant contribution to the oxidation stability of vegetable oils marketed in Korea. Ten kinds, 97 items of vegetable oils that were produced in either an industrialized or a traditional way were collected and analyzed for their fatty acid compositions and lipid oxidation products, in the absence or presence of oxidative stress. Peroxidability index (PI) calculations based on the fatty acid composition ranged from 7.10 to 111.87 with the lowest value found in olive oils and the highest in perilla oils. In the absence of induced oxidative stress, malondialdehyde (MDA), the secondary lipid oxidation product, was generated more in the oils with higher PI (r=0.890), while the tendency was not observed when the oils were subjected to an oxidation-accelerating system. In the presence of the oxidative stress, the perilla oils produced in an industrialized manner generated appreciably higher amounts of MDA than those produced in a traditional way, although both types of oils presented similar PIs. The results implicate that the fatty acid compositions could be a predictor for the oxidation stability of the vegetable oils at the early stage of oil oxidation, but not for those at a later stage of oxidation. PMID:24471078

  11. Investigation of Metal Oxide/Carbon Nano Material as Anode for High Capacity Lithium-ion Cells

    NASA Technical Reports Server (NTRS)

    Wu, James Jianjun; Hong, Haiping

    2014-01-01

    NASA is developing high specific energy and high specific capacity lithium-ion battery (LIB) technology for future NASA missions. Current state-of-art LIBs have issues in terms of safety and thermal stability, and are reaching limits in specific energy capability based on the electrochemical materials selected. For example, the graphite anode has a limited capability to store Li since the theoretical capacity of graphite is 372 mAh/g. To achieve higher specific capacity and energy density, and to improve safety for current LIBs, alternative advanced anode, cathode, and electrolyte materials are pursued under the NASA Advanced Space Power System Project. In this study, the nanostructed metal oxide, such as Fe2O3 on carbon nanotubes (CNT) composite as an LIB anode has been investigated.

  12. Iron sulfide oxidation and the chemistry of acid generation

    NASA Astrophysics Data System (ADS)

    Sullivan, Patrick J.; Yelton, Jennifer L.; Reddy, K. J.

    1988-06-01

    Acid mine drainage, produced from the oxidation of iron sulfides, often contains elevated levels of dissolved aluminum (AI), iron (Fe), and sulfate (SO4) and low pH. Understanding the interactions of these elements associated with acid mine drainage is necessary for proper solid waste management planning. Two eastern oil shales were leached using humidity cell methods. This study used a New Albany Shale (4.6 percent pyrite) and a Chattanooga Shale (1.5 percent pyrite). The leachates from the humidity cells were filtered, and the filtrates were analyzed for total concentrations of cations and anions. After correcting for significant solution species and complexes, ion activities were calculated from total concentrations. The results show that the activities of Fe3+, Fe2+, Al3+, and SO4 2- increased due to the oxidation of pyrite. Furthermore, the oxidation of pyrite resulted in a decreased pH and an increased pe+pH (redox-potential). The Fe3+ and Fe2+ activities appeared to be controlled by amorphous Fe(OH)3 solid phase above a pH of 6.0 and below pe+pH 11.0. The Fe3+, Fe2+, and SO4 2- activities reached saturation with respect to FeOHSO4 solid phase between pH 3.0 and 6.0 and below pe+pH 11.0 Below a pH of 3.0 and above a pe+pH of 11.0, Fe2+, Fe3+, and SO4 2- activities are supported by FeSO4·7H2O solid phase. Above a pH of 6.0, the Al3+ activity showed an equilibrium with amorphous Al(OH)3 solid phase. Below pH 6.0, Al3+ and SO4 2- activities are regulated by the AlOHSO4 solid phase, irrespective of pe+pH. The results of this study suggest that under oxidizing conditions with low to high leaching potential, activities of Al and Fe can be predicted on the basis of secondary mineral formation over a wide range of pH and redox. As a result, the long-term chemistry associated with disposal environments can be largely predicted (including trace elements).

  13. The transcriptional coactivator PGC-1α is essential for maximal and efficient cardiac mitochondrial fatty acid oxidation and lipid homeostasis

    PubMed Central

    Lehman, John J.; Boudina, Sihem; Banke, Natasha Hausler; Sambandam, Nandakumar; Han, Xianlin; Young, Deanna M.; Leone, Teresa C.; Gross, Richard W.; Lewandowski, E. Douglas; Abel, E. Dale; Kelly, Daniel P.

    2008-01-01

    High-capacity mitochondrial ATP production is essential for normal function of the adult heart, and evidence is emerging that mitochondrial derangements occur in common myocardial diseases. Previous overexpression studies have shown that the inducible transcriptional coactivator peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α is capable of activating postnatal cardiac myocyte mitochondrial biogenesis. Recently, we generated mice deficient in PGC-1α (PGC-1α−/− mice), which survive with modestly blunted postnatal cardiac growth. To determine if PGC-1α is essential for normal cardiac energy metabolic capacity, mitochondrial function experiments were performed on saponin-permeabilized myocardial fibers from PGC-1α−/− mice. These experiments demonstrated reduced maximal (state 3) palmitoyl-l-carnitine respiration and increased maximal (state 3) pyruvate respiration in PGC-1α−/− mice compared with PGC-1α+/+ controls. ATP synthesis rates obtained during maximal (state 3) respiration in permeabilized myocardial fibers were reduced for PGC-1α−/− mice, whereas ATP produced per oxygen consumed (ATP/O), a measure of metabolic efficiency, was decreased by 58% for PGC-1α−/− fibers. Ex vivo isolated working heart experiments demonstrated that PGC-1α−/− mice exhibited lower cardiac power, reduced palmitate oxidation, and increased reliance on glucose oxidation, with the latter likely a compensatory response. 13C NMR revealed that hearts from PGC-1α−/− mice exhibited a limited capacity to recruit triglyceride as a source for lipid oxidation during β-adrenergic challenge. Consistent with reduced mitochondrial fatty acid oxidative enzyme gene expression, the total triglyceride content was greater in hearts of PGC-1α−/− mice relative to PGC-1α+/+ following a fast. Overall, these results demonstrate that PGC-1α is essential for the maintenance of maximal, efficient cardiac mitochondrial fatty acid oxidation, ATP

  14. Exposure assessment of oxidant gases and acidic aerosols

    SciTech Connect

    Lioy, P.J.

    1989-01-01

    Clearly the presence of high ozone and acidic species in North America is primarily dependent upon photochemical air pollution. Evidence shows, however, that high acid exposures may occur in specific types of areas of high sulfur fuel use during the winter. At the present time, our concerns about exposure to local populations and regional populations should be directed primarily toward the outdoor activity patterns of individuals in the summer, and how those activity patterns relate to the location, duration, and concentrations of ozone and acid aerosol in photochemical air pollution episodes. Lioy Dyba and Mage et al have examined the activity patterns of children in summer camps. Because they spend more time outside than the normal population, these children form an important group of exercising individuals subject to photochemical pollution exposures. The dose of ozone inhaled by the children in the two camps was within 50% and 25% of the dose inhaled by adults in controlled clinical situations that produced clinically significant decrements in pulmonary function and increased the symptoms after 6.6 hr exposure in a given day. The chamber studies have used only ozone, whereas in the environment this effect may be enhanced by the presence of a complex mixture. The work of Lioy et al in Mendham, New Jersey found that hydrogen ion seemed to play a role in the inability of the children to return immediately to their normal peak expiratory flow rate after exposure. The camp health study conducted in Dunsville, Ontario suggested that children participating in a summer camp where moderate levels of ozone (100 ppb) but high levels of acid (46 micrograms/m3) occurred during an episode had a similar response. Thus, for children or exercising adults who are outdoors for at least one hour or more during a given day, the presence and persistence of oxidants in the environment are of particular concern. 63 references.

  15. Fatty Acids Profile, Phenolic Compounds and Antioxidant Capacity in Elicited Callus ofThevetia peruviana (Pers.) K. Schum.

    PubMed

    Rincón-Pérez, Jack; Rodríguez-Hernández, Ludwi; Ruíz-Valdiviezo, Víctor Manuel; Abud-Archila, Miguel; Luján-Hidalgo, María Celina; Ruiz-Lau, Nancy; González-Mendoza, Daniel; Gutiérrez-Miceli, Federico Antonio

    2016-04-01

    The aim of this study was analyze the effect of jasmonic acid (JA) and abscisic acid (ABA) as elicitors on fatty acids profile (FAP), phenolic compounds (PC) and antioxidant capacity (AC) in callus of Thevetia peruviana. Schenk & Hildebrandt (SH) medium, supplemented with 2 mg/L 2, 4-dichlorophenoxyacetic (2, 4-D) and 0.5 mg/L kinetin (KIN) was used for callus induction. The effect of JA (50, 75 and 100 μM) and ABA (10, 55 and 100 μM) on FAP, PC and AC were analyzed using a response surface design. A maximum of 2.8 mg/g of TPC was obtained with 100 plus 10 µM JA and ABA, respectively, whereas AC maximum (2.17 μg/mL) was obtained with 75 plus 100 µM JA and ABA, respectively. The FAP was affected for JA but not for ABA. JA increased cis-9, cis-12-octadecadienoic acid and decreased dodecanoic acid. Eight fatty acids were identified by GC-MS analysis and cis-9-octadecenoic acid (18:1) was the principal fatty acid reaching 76 % in treatment with 50 μM JA plus 55 μM ABA. In conclusion, JA may be used in T. peruviana callus culture for obtain oil with different fatty acids profile. PMID:26972464

  16. [The influence of panthotenic acid mitochondrial oxidation and oxidative phosphorylation in liver of rats with alimentary obesity].

    PubMed

    Naruta, E E; Egorov, A I; Omel'ianchik, C N; Buko, V U

    2004-01-01

    Alimentary obesity induced by the long-term feeding of rats by high-fat diet results the reducing of rate and efficiency of oxidative phosphorylation in liver mitochondria when NAD-dependent substrates are used. The treatment of the obese rats with panthotenic acid derivatives (phosphopantotenate, panthetin, panthenol) enhanced oxidative phosphorylation of pyruvate and fatty acid carnitine esters. Among investigated compounds panthenol activated respiratory control and phosphorylation rate more effectively. Moreover, panthenol, but not phosphopanthotenate nor panthetine, increased the activity of carnitine palmitoyltransferase 1 that confirms the preferable usage of fatty acids for mitochondrial oxidation under the influence of this compound. PMID:15460980

  17. The role of oxygen vacancies and defects on Lithium intercalation capacity of composite vanadium-titanium oxide thin films

    NASA Astrophysics Data System (ADS)

    Sahana, M. B.; Sudakar, C.; Thapa, C.; Lawes, G.; Padmanabhan, K. R.; Naik, R.; Auner, G.; Naik, V. M.

    2008-03-01

    Composite films of vanadium-titanium oxides have been recognized as promising cathode materials for lithium ion batteries. While there is a consensus agreement that the cycling stability of the mixed V/Ti-oxide system is improved compared to V2O5 thin films, there are different findings on the Li+ intercalation capacity of V2O5 with the addition of TiO2. To understand the difference we have carried out a systematic semi quantitative investigations on the defect and oxygen vacancy concentration as determined using Raman and UV-visible spectroscopy and transmission electron microscopy of V2O5 and 5%Ti doped V2O5 films prepared by spin coating using two precursors: a metalorganic and a organic sol gel precursor. We observe that a critical concentration of defects and oxygen vacancies is important to have high capacity. With 5% Ti doping the capacity in films prepared using solgel precursor increases, but the capacity decreases in films prepared with the metalorganic precursor. We attribute this to the different concentrations of oxygen vacancy defects in the two samples.

  18. Dietary lipid quality and mitochondrial membrane composition in trout: responses of membrane enzymes and oxidative capacities.

    PubMed

    Martin, N; Bureau, D P; Marty, Y; Kraffe, E; Guderley, H

    2013-04-01

    To examine whether membrane fatty acid (FA) composition has a greater impact upon specific components of oxidative phosphorylation or on overall properties of muscle mitochondria, rainbow trout (Oncorhynchus mykiss) were fed two diets differing only in FA composition. Diet 1 was enriched in 18:1n-9 and 18:2n-6 while Diet 2 was enriched in 22:6n-3. The FA composition of mitochondrial phospholipids was strongly affected by diet. 22:6n-3 levels were twice as high (49%) in mitochondrial phospholipids of fish fed Diet 2 than in those fed Diet 1. 18:2n-6 content of the phospholipids also followed the diets, whereas 18:1n-9 changed little. All n-6 FA, most notably 22:5n-6, were significantly higher in fish fed Diet 1. Nonetheless, total saturated FA, total monounsaturated FA and total polyunsaturated FA in mitochondrial phospholipids varied little. Despite a marked impact of diet on specific FA levels in mitochondrial phospholipids, only non-phosphorylating (state 4) rates were higher in fish fed Diet 2. Phosphorylating rates (state 3), oxygen consumption due to flux through the electron transport chain complexes as well as the corresponding spectrophotometric activities did not differ with diet. Body mass affected state 4 rates and cytochrome c oxidase and F 0 F 1 ATPase activities while complex I showed a diet-specific effect of body mass. Only the minor FA that were affected by body mass were correlated with functional properties. The regulated incorporation of dietary FA into phospholipids seems to allow fish to maintain critical membrane functions even when the lipid quality of their diets varies considerably, as is likely in their natural environment. PMID:23052948

  19. Sacha inchi (Plukenetia volubilis): a seed source of polyunsaturated fatty acids, tocopherols, phytosterols, phenolic compounds and antioxidant capacity.

    PubMed

    Chirinos, Rosana; Zuloeta, Gledy; Pedreschi, Romina; Mignolet, Eric; Larondelle, Yvan; Campos, David

    2013-12-01

    Fatty acids (FA), phytosterols, tocopherols, phenolic compounds, total carotenoids and hydrophilic and lipophilic ORAC antioxidant capacities were evaluated in 16 cultivars of Sacha inchi (SI) seeds with the aim to valorise them and offer more information on the functional properties of SI seeds. A high α linolenic (α-Ln) fatty acid content was found in all cultivars (ω3, 12.8-16.0 g/100 g seed), followed by linoleic (L) fatty acid (ω6, 12.4-14.1g/100g seed). The ratio ω6/ω3 was within the 0.83-1.09 range. γ- and δ-tocopherols were the most important tocopherols, whereas the most representative phytosterols were β-sitosterol and stigmasterol. Contents of total phenolics, total carotenoids and hydrophilic and lipophilic antioxidant capacities ranged from 64.6 to 80 mg of gallic acid equivalent/100g seed; from 0.07 to 0.09 mg of β-carotene equivalent/100g of seed; from 4.3 to 7.3 and, from 1.0 to 2.8 μmol of Trolox equivalent/g of seed, respectively, among the evaluated SI cultivars. Results showed significant differences (p<0.05) among the evaluated SI cultivars in the contents of ω3, ω6, antioxidant capacities and other evaluated phytochemicals. SI seeds should be considered as an important dietary source of health promoting phytochemicals. PMID:23870885

  20. Polyphenols: well beyond the antioxidant capacity: gallic acid and related compounds as neuroprotective agents: you are what you eat!

    PubMed

    Daglia, Maria; Di Lorenzo, Arianna; Nabavi, Seyed F; Talas, Zeliha S; Nabavi, Seyed M

    2014-01-01

    Gallic acid (3,4,5-trihydroxybenzoic acid) is a phenolic acid widely distributed in many different families of higher plants, both in free state, and as a part of more complex molecules, such as ester derivatives or polymers. In nature, gallic acid and its derivatives are present in nearly every part of the plant, such as bark, wood, leaf, fruit, root and seed. They are present in different concentrations in common foodstuffs such as blueberry, blackberry, strawberry, plums, grapes, mango, cashew nut, hazelnut, walnut, tea, wine and so on. After consumption, about 70% of gallic acid is adsorbed and then excreted in the urine as 4-O-methylgallic acid. Differently, the ester derivatives of gallic acid, such as catechin gallate ester or gallotannins, are hydrolyzed to gallic acid before being metabolized to methylated derivatives. Gallic acid is a well known antioxidant compounds which has neuroprotective actions in different models of neurodegeneration, neurotoxicity and oxidative stress. In this review, we discuss about the neuroprotective actions of gallic acid and derivatives and their potential mechanisms of action. PMID:24938889

  1. An injectable oxidated hyaluronic acid/adipic acid dihydrazide hydrogel as a vitreous substitute.

    PubMed

    Su, Wen-Yu; Chen, Ko-Hua; Chen, Yu-Chun; Lee, Yen-Hsien; Tseng, Ching-Li; Lin, Feng-Huei

    2011-01-01

    Vitrectomy is a common procedure for treating ocular-related diseases. The surgery involves removing the vitreous humor from the center of the eye, and vitreous substitutes are needed to replace the vitreous humor after vitrectomy. In the present study, we developed a colorless, transparent and injectable hydrogel with appropriate refractive index as a vitreous substitute. The hydrogel is formed by oxidated hyaluronic acid (oxi-HA) cross-linked with adipic acid dihydrazide (ADH). Hyaluronic acid (HA) was oxidized by sodium periodate to create aldehyde functional groups, which could be cross-linked by ADH. The refractive index of this hydrogel ranged between 1.3420 and 1.3442, which is quite similar to human vitreous humor (1.3345). The degradation tests demonstrated that the hydrogel could maintain the gel matrix over 35 days, depending on the ADH concentration. In addition, the cytotoxicity was evaluated on retina pigmented epithelium (RPE) cells cultivated following the ISO standard (tests for in vitro cytotoxicity), and the hydrogel was found to be non-toxic. In a preliminary animal study, the oxi-HA/ADH hydrogel was injected into the vitreous cavity of rabbit eyes. The evaluations of slit-lamp observation, intraocular pressure, cornea thickness and histological examination showed no significant abnormal biological reactions for 3 weeks. This study suggests that the injectable oxi-HA/ADH hydrogel should be a potential vitreous substitute. PMID:20843434

  2. Injectable oxidized hyaluronic acid/adipic acid dihydrazide hydrogel for nucleus pulposus regeneration.

    PubMed

    Su, Wen-Yu; Chen, Yu-Chun; Lin, Feng-Huei

    2010-08-01

    Injectable hydrogel allows irregular surgical defects to be completely filled, lessens the risk of implant migration, and minimizes surgical defects due to the solution-gel state transformation. Here, we first propose a method for preparing oxidized hyaluronic acid/adipic acid dihydrazide (oxi-HA/ADH) injectable hydrogel by chemical cross-linking under physiological conditions. Fourier transform infrared spectrometry and trinitrobenzene sulfonate assay were used to confirm the oxidation of hyaluronic acid. Rheological properties were measured to evaluate the working ability of the hydrogel for further clinical application. The oxi-HA/ADH in situ forming hydrogel can transform from liquid form into a gel-like matrix within 3-8 min, depending on the operational temperature. Furthermore, hydrogel degradation and cell assessment is also a concern for clinical application. Injectable oxi-HA/ADH8 hydrogel can maintain its gel-like state for at least 5 weeks with a degradation percentage of 40%. Importantly, oxi-HA/ADH8 hydrogel can assist in nucleus pulposus cell synthesis of type II collagen and aggrecan mRNA gene expression according to the results of real-time PCR analysis, and shows good biocompatibility based on cell viability and cytotoxicity assays. Based on the results of the current study, oxi-HA/ADH hydrogel may possess several advantages for future application in nucleus pulposus regeneration. PMID:20193782

  3. The effect and mechanism of bismuth doped lead oxide on the performance of lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Chen, H. Y.; Wu, L.; Ren, C.; Luo, Q. Z.; Xie, Z. H.; Jiang, X.; Zhu, S. P.; Xia, Y. K.; Luo, Y. R.

    Flooded automotive and motorcycle lead-acid batteries were manufactured from three kinds of lead oxides including electrolyzed pure lead (99.99 wt.% Pb) oxide, electrolyzed pure lead oxide doped with Bi 2O 3 (0.02 wt.% Bi 2O 3) and bismuth-bearing refined lead (0.02 wt.% Bi) oxide. The first cranking and cold cranking curves of the automotive batteries show that there is no obvious difference among the above lead oxides. Bismuth in lead oxide does not affect the water loss of flooded batteries. However, bismuth results in the improvement of capacity and charge-acceptance capability. In discharge, the positive voltage versus cadmium of plates with bismuth decreases more slowly than that of plates without bismuth. In order to investigate the mechanism of the function of bismuth, three other kinds of test electrodes were prepared from electrolyzed pure lead (99.99 wt.% Pb) oxide, electrolyzed pure lead oxide doped 0.02 wt.% Bi 2O 3 and electrolyzed pure lead oxide doped 0.06 wt.% Bi 2O 3. The cyclic voltammetry curve shows that bismuth has no significant influence on the electrochemical behavior of the positive active-material. There is an opposite result concerning the cathodic polarization curves between bismuth doped in the electrode and Bi 3+ ion doped in the electrolyte. Bismuth doped in the electrode results in a decrease of the hydrogen overpotential. Conversely, Bi 3+ ion doped in the electrolyte results is an increase. The chemical analysis confirms that a trace of Bi 3+ ion exists in sulfuric acid solution (e.g. plates soaking, after formation, after cycling). A higher porosity is observed in the positive active-material containing bismuth by SEM technique. SEM morphology shows that needle-like crystals begin to occur after a few cycles. X-ray diffraction phase analysis proves that the amount of α-PbO 2 is increased by doping bismuth in to lead oxide. The existing forms, chemical characteristics and electrochemical reactions of bismuth during manufacture

  4. Triiodothyronine activates lactate oxidation without impairing fatty acid oxidation and improves weaning from extracorporeal membrane oxygenation

    SciTech Connect

    Kajimoto, Masaki; Ledee, Dolena R.; Xu, Chun; Kajimoto, Hidemi; Isern, Nancy G.; Portman, Michael A.

    2014-01-01

    Background: Extracorporeal membrane oxygenation (ECMO) provides a rescue for children with severe cardiac failure. We previously showed that triiodothyronine (T3) improves cardiac function by modulating pyruvate oxidation during weaning. This study was focused on fatty acid (FA) metabolism modulated by T3 for weaning from ECMO after cardiac injury. Methods: Nineteen immature piglets (9.1-15.3 kg) were separated into 3 groups with ECMO (6.5 hours) and wean: normal circulation (Group-C);transient coronary occlusion (10 minutes) followed by ECMO (Group-IR); and IR with T3 supplementation (Group-IR-T3). 13-Carbon labeled lactate, medium-chain and long-chain FAs were infused as oxidative substrates. Substrate fractional contribution to the citric acid cycle (FC) was analyzed by 13-Carbon nuclear magnetic resonance. Results: ECMO depressed circulating T3 levels to 40% baseline at 4 hours and were restored in Group-IR-T3. Group-IR decreased cardiac power, which was not fully restorable and 2 pigs were lost because of weaning failure. Group-IR also depressed FC-lactate, while the excellent contractile function and energy efficiency in Group-IR-T3 occurred along with a marked FC-lactate increase and [ATP]/[ADP] without either decreasing FC-FAs or elevating myocardial oxygen consumption over Group-C or -IR. Conclusions: T3 releases inhibition of lactate oxidation following ischemia-reperfusion injury without impairing FA oxidation. These findings indicate that T3 depression during ECMO is maladaptive, and that restoring levels improves metabolic flux and enhances contractile function during weaning.

  5. Lewis Acid Catalysis in the Oxidative Cycloaddition of Thiophenes(1).

    PubMed

    Li, Yuanqiang; Thiemann, Thies; Sawada, Tsuyoshi; Mataka, Shuntaro; Tashiro, Masashi

    1997-11-14

    Thiophenes 1 were treated with m-chloroperbenzoic acid (m-CPBA) under BF(3).Et(2)O catalysis to afford thiophene S-monoxides. These could be reacted in situ as intermediary species with a number of dienophiles to provide arenes (with alkynes as dienophiles) or 7-thiabicyclo[2.2.1]hept-2-ene 7-oxides (with alkenes as dienophiles). It was also possible to isolate thiophene S-monoxides in solution and to cycloadd them in a second step. In either way it could be shown that the use of BF(3).Et(2)O enhances the yields of the oxidative cycloaddition of thiophenes considerably. Moreover a greater variety of dienophiles (29a, 29b, 29c) could be reacted with thiophenes than in the case of the noncatalyzed reaction. All cycloadditions catalyzed by BF(3).Et(2)O give only a single diastereoisomer as cycloadduct. The reactions show a high pi-facial selectivity, a fact that can be explained by the Cieplak-effect. Without added dienophiles, 2-methylthiophene (1e) gave a single dimer (36) of 2-methylthiophene S-monoxide, whereas 2,5-dimethylthiophene (1a) gave three dimers (32a-c). In the case of tetrasubstituted thiophenes, thiophene S-monoxides (e.g., 31b and 31c) could be isolated in substance. PMID:11671894

  6. Influence of rutin and ascorbic acid in colour, plum anthocyanins and antioxidant capacity stability in model juices.

    PubMed

    Hernández-Herrero, J A; Frutos, M J

    2015-04-15

    Model juices at pH 3.7 were prepared with different combinations of ascorbic acid, rutin (quercetin 3-rutinoside) and concentrated anthocyanin extract of plums (cv. Black Gold). The anthocyanins in the concentrated extract were cyanidin 3-glucoside and cyanidin 3-rutinoside, in a proportion of 76% and 24% respectively. The model juices were stored during 17 weeks in darkness at 20 °C. The colour stability was improved by the presence of rutin and strongly damaged by the ascorbic acid. The fortification of anthocyanin model juices with ascorbic acid originated the degradation of most of anthocyanins. However, anthocyanins improved ascorbic acid stability during storage. The copigmentation of anthocyanin and rutin showed a beneficial effect on colour stability from the 5 weeks of storage. In model juices prepared exclusively with purified plum extract a high correlation (R(2)=0.881) between anthocyanins and antioxidant capacity was found. PMID:25466051

  7. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    NASA Technical Reports Server (NTRS)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  8. Effects of standtime on the available capacity of lead-acid and nickel/iron electric vehicle batteries

    SciTech Connect

    DeLuca, W.H.; Biwer, R.L.; Tummillo, A.F.; Yao, N.P.

    1984-08-01

    In electric vehicle (EV) applications, the battery load typically contains interruptions of various time durations. These standtimes affect the battery's available capacity and must be understood in order to predict and optimize vehicle operation. Laboratory tests were conducted to measure the impact of various standtimes (0-4 h) at different depth-of-discharge (DOD) and state-of-charge (SOC) levels on the capacity retention of both improved lead-acid and nickel/iron (Ni/Fe) EV batteries. The results showed that the Ni/Fe system exhibits a self-discharge capacity loss immediately after charging that increases with both standtime and SOC. Fortunately, the self-discharge rate decreases rapidly with standtime and discharging.

  9. Pressurized water extraction of β-glucan enriched fractions with bile acids-binding capacities obtained from edible mushrooms.

    PubMed

    Palanisamy, Marimuthu; Aldars-García, Laila; Gil-Ramírez, Alicia; Ruiz-Rodríguez, Alejandro; Marín, Francisco R; Reglero, Guillermo; Soler-Rivas, Cristina

    2014-01-01

    A pressurized water extraction (PWE) method was developed in order to extract β-glucans with bile acids-binding capacities from cultivated mushrooms (Agaricus bisporus, Lentinula edodes, and Pleurotus ostreatus) to be used as supplements to design novel foods with hypocholesterolemic properties. Extraction yields were higher in individual than sequential extractions being the optimal extraction parameters: 200°C, 5 cycles of 5 min each at 10.3 MPa. The crude polysaccharide (PSC) fractions, isolated from the PWE extracts contained mainly β-glucans (including chitooligosaccharides deriving from chitin hydrolysis), α-glucans, and other PSCs (hetero-/proteo-glucans) depending on the extraction temperature and mushroom strain considered. The observed bile acids-binding capacities of some extracts were similar to a β-glucan enriched fraction obtained from cereals. PMID:24399760

  10. Myrrh attenuates oxidative and inflammatory processes in acetic acid-induced ulcerative colitis

    PubMed Central

    Fatani, Amal Jamil; Alrojayee, Fatima Salih; Parmar, Mihir Yogeshkumar; Abuohashish, Hatem Mustafa; Ahmed, Mohammed Mahboobuddin; Al-Rejaie, Salim Salih

    2016-01-01

    The pathogenesis of ulcerative colitis (UC) has been associated with a weakened antioxidant capacity and increased inflammatory processes. Myrrh is traditionally used for the treatment of inflammatory diseases due to its antioxidant and anti-inflammatory properties. The present study aimed to evaluate the effects of myrrh on an experimental rat model of UC. UC was induced in rats using acetic acid (AA) after pre-treatment with myrrh (125, 250 or 500 mg/kg/day) or mesalazine (MES; 300 mg/kg/day) for 7 days. The levels of various inflammatory cytokines, prostaglandin E2 (PGE2) and nitric oxide (NO) in the rat colon tissues were assessed. In addition, the colonic levels of thiobarbituric acid reactive substances (TBARS) and non-protein sulfhydryl groups (NP-SH), as well as the activities of superoxide dismutase (SOD) and catalase (CAT), were estimated. Furthermore, total protein (TP) contents and the levels of DNA and RNA were measured, and histopathological changes in colonic tissues were analyzed. The results indicated that the levels of pro-inflammatory cytokines, PGE2, NO and TBARS were markedly increased. By contrast, the levels of interleukin-10, NP-SH, TP and nucleic acids, and the enzymatic activities of SOD and CAT were significantly decreased in the AA model group. In addition, pretreatment with myrrh and MES was able to attenuate the impaired oxidative stress response and upregulation of inflammatory biomarkers. Furthermore, the enzymatic activities of SOD and CAT were near to normal in the myrrh and MES pretreated groups. The ability of myrrh to protect against UC was further confirmed by histopathological analysis, and the high dose of myrrh exerted an effect comparable to MES. In conclusion, the results of the present study suggested that myrrh has potent therapeutic value in the amelioration of experimental colitis in laboratory animals by downregulating the expression of proinflammatory mediators and improving endogenous antioxidative activities. PMID

  11. The influence of temperature on the discharge capacity of positive lead—acid battery plates. Theory and experiments

    NASA Astrophysics Data System (ADS)

    Micka, K.; Koudelka, V.

    1981-10-01

    A theoretical expression has been derived for the dependence of the discharge capacity, C, of the positive plate of the lead—acid battery, on the temperature, T, in the form dln C/d T = ( k - 1)(dlnκ/d T + 1/ T), where k is the coefficient of Peukert's equation and κ is the specific conductivity of the electrolyte. This formula was confirmed by measurements on SLI battery positive plates.

  12. Reversing and nonreversing heat capacity of poly(lactic acid) in the glass transition region by TMDSC

    SciTech Connect

    Pyda, Marek {nmn}; Wunderlich, Bernhard {nmn}

    2005-11-01

    A study of the glass transition of an amorphous and a semicrystalline poly(lactic acid) (PLA) is performed with adiabatic calorimetry, differential scanning calorimetry (DSC), and temperature-modulated DSC (TMDSC). The reversing, total, and nonreversing apparent heat capacities of samples with different contents of L- and D-lactic acid and with various thermal histories were evaluated. Different modes of TMDSC analyses of amorphous and semicrystalline PLA were compared to the total heat capacity from standard DSC. The enthalpy relaxation and the cold crystallization in the glass transition region are largely irreversible. The melting is largely irreversible, but a 100% reversing fraction is observed at low temperatures from 375 to 420 K, which becomes small inside the major melting peak at about 440 K. From the TMDSC of amorphous PLA, the combined information on endothermic and exothermic enthalpy relaxation and glass transition were deconvoluted into the reversing and nonreversing components. The glass transition temperature from the reversing heat capacity and the enthalpy relaxation peaks from the nonreversing component shift to higher temperature for increasingly annealed PLA. The relaxation times for aging decrease on cooling until the glass transition is reached and then increase. This behavior is linked to cooperativity. All quantitative thermal analyses are based on the heat capacity of the solid and liquid, evaluated earlier with the advanced thermal analysis system (ATHAS).

  13. Oxidative capacity of the Mexico City atmosphere - Part 1: A radical source perspective

    NASA Astrophysics Data System (ADS)

    Volkamer, R.; Sheehy, P. M.; Molina, L. T.; Molina, M. J.

    2007-04-01

    A detailed analysis of OH, HO2 and RO2 radical sources is presented for the near field photochemical regime inside the Mexico City Metropolitan Area (MCMA). During spring of 2003 (MCMA-2003 field campaign) an extensive set of measurements was collected to quantify time resolved ROx (sum of OH, HO2, RO2) radical production rates from day- and nighttime radical sources. The Master Chemical Mechanism (MCMv3.1) was constrained by measurements of (1) concentration time-profiles of photosensitive radical precursors, i.e., nitrous acid (HONO), formaldehyde (HCHO), ozone (O3), glyoxal (CHOCHO), and other oxygenated volatile organic compounds (OVOCs); (2) respective photolysis-frequencies (J-values); (3) concentration time-profiles of alkanes, alkenes, and aromatic VOCs (103 compound are treated) and oxidants, i.e., OH- and NO3 radicals, O3; and (4) NO, NO2, meteorological and other parameters. The ROx production rate was calculated directly from these observations; MCM was used to estimate further ROx production from unconstrained sources, and express overall ROx production as OH-equivalents (i.e., taking into account the propagation efficiencies of RO2 and HO2 radicals into OH radicals). Daytime radical production is found to be about 10-25 times higher than at night; it does not track the abundance of sunlight. 12-h average daytime contributions of individual sources are: HCHO and O3 photolysis, each about 20%; O3/alkene reactions and HONO photolysis, each about 15%; unmeasured sources about 30%. While the direct contribution of O3/alkene reactions appears to be moderately small, source-apportionment of ambient HCHO and HONO identifies O3/alkene reactions as being largely responsible for jump-starting photochemistry about one hour after sunrise. The peak radical production is found to be higher than in any other urban influenced environment studied to date; further, differences exist in the timing of radical production. Our measurements and analysis comprise a database

  14. Autotrophic, sulfur-oxidizing actinobacteria in acidic environments.

    PubMed

    Norris, Paul R; Davis-Belmar, Carol S; Brown, Carly F; Calvo-Bado, Leonides A

    2011-03-01

    Some novel actinobacteria from geothermal environments were shown to grow autotrophically with sulfur as an energy source. These bacteria have not been formally named and are referred to here as "Acidithiomicrobium" species, as the first of the acidophilic actinobacteria observed to grow on sulfur. They are related to Acidimicrobium ferrooxidans with which they share a capacity for ferrous iron oxidation. Ribulose bisphosphate carboxylase/oxygenase (RuBisCO) is active in CO(2) fixation by Acidimicrobium ferrooxidans, which appears to have acquired its RuBisCO-encoding genes from the proteobacterium Acidithiobacillus ferrooxidans or its ancestor. This lateral transfer of RuBisCO genes between a proteobacterium and an actinobacterium would add to those noted previously among proteobacteria, between proteobacteria and cyanobacteria and between proteobacteria and plastids. "Acidithiomicrobium" has RuBisCO-encoding genes which are most closely related to those of Acidimicrobium ferrooxidans and Acidithiobacillus ferrooxidans, and has additional RuBisCO genes of a different lineage. 16S rRNA gene sequences from "Acidithiomicrobium" species dominated clone banks of the genes extracted from mixed cultures of moderate thermophiles growing on copper sulfide and polymetallic sulfide ores in ore leaching columns. PMID:21308384

  15. Comparison of Total Antioxidant Capacity Oxidative Stress and Blood Lipoprotein Parameters in Volleyball Players and Sedentary

    ERIC Educational Resources Information Center

    Gokhan, Ismail

    2013-01-01

    This study aims to measure, then compare sedentary blood lipoproteins, oxidant- antioxidant state and oxidative stress index in volleyball players. The experimental group of the research consists of regularly practising 20 boys between the ages of 12 and 17, and the control group comprises 32 children practising no particular sports branch, 12 of…

  16. Reducing Capacity, Chlorogenic Acid Content and Biological Activity in a Collection of Scarlet (Solanum aethiopicum) and Gboma (S. macrocarpon) Eggplants

    PubMed Central

    Plazas, Mariola; Prohens, Jaime; Cuñat, Amparo Noelia; Vilanova, Santiago; Gramazio, Pietro; Herraiz, Francisco Javier; Andújar, Isabel

    2014-01-01

    Scarlet (Solanum aethiopicum) and gboma (S. macrocarpon) eggplants are important vegetables in Sub-Saharan Africa. Few studies have been made on these crops regarding the diversity of phenolic content and their biological activity. We have studied the reducing activity, the chlorogenic acid and other phenolic acid contents in a collection of 56 accessions of scarlet eggplant, including the four cultivated groups (Aculeatum, Gilo, Kumba, Shum) and the weedy intermediate S. aethiopicum-S. anguivi types, as well as in eight accessions of gboma eggplant, including the cultivated S. macrocarpon and its wild ancestor, S. dasyphyllum. A sample of the accessions evaluated in this collection has been tested for inhibition of nitric oxide (NO) using macrophage cell cultures. The results show that there is a great diversity in both crops for reducing activity, chlorogenic acid content and chlorogenic acid peak area (% of total phenolic acids). Heritability (H2) for these traits was intermediate to high in both crops. In all samples, chlorogenic acid was the major phenolic acid and accounted for more than 50% of the chromatogram peak area. Considerable differences were found among and within groups for these traits, but the greatest values for total phenolics and chlorogenic acid content were found in S. dasyphyllum. In most groups, reducing activity was positively correlated (with values of up to 0.904 in the Aculeatum group) with chlorogenic acid content. Inhibition of NO was greatest in samples having a high chlorogenic acid content. The results show that both crops are a relevant source of chlorogenic acid and other phenolic acids. The high diversity found also indicates that there are good prospects for breeding new scarlet and gboma eggplant cultivars with improved content in phenolics and bioactive properties. PMID:25264739

  17. Carboxylic acids in secondary aerosols from oxidation of cyclic monoterpenes by ozone

    SciTech Connect

    Glasius, M.; Lahaniati, M.; Calogirou, A.; Di Bella, D.; Jensen, N.R.; Hjorth, J.; Kotzias, D.; Larsen, B.R.

    2000-03-15

    A series of smog chamber experiments have been conducted in which five cyclic monoterpenes were oxidized by ozone. The evolved secondary aerosol was analyzed by GC-MS and HPLC-MS for nonvolatile polar oxidation products with emphasis on the identification of carboxylic acids. Three classes of compounds were determined at concentration levels corresponding to low percentage molar yields: i.e., dicarboxylic acids, oxocarboxylic acids, and hydroxyketocarboxylic acids. Carboxylic acids are highly polar and have lower vapor pressures than their corresponding aldehydes and may thus play an important role in secondary organic aerosol formation processes. The most abundant carboxylic acids were the following: cis-pinic acid AB1(cis-3-carboxy-2,2-dimethylcyclobutylethanoic acid) from {alpha} and {beta}-pinene; cis-pinonic acid A3 (cis-3-acetyl-2,2-dimethylcyclobutylethanoic acid) and cis-10-hydroxypinonic acid Ab6 (cis-2,2-dimethyl-3-hydroxyacetylcyclobutyl-ethanoic acid) from {alpha}-pinene and {beta}-pinene; cis-3-caric acid C1 (cis-2,2-dimethyl-1,3-cyclopropyldiethanoic acid), cis-3-caronic acid C3 (2,2-dimethyl-3-(2-oxopropyl)cyclopropanylethanoic acid), and cis-10-hydroxy-3-caronic acid C6 (cis-2,2-dimethyl-3(hydroxy-2-oxopropyl)cyclopropanylethanoic acid) from 3-carene; cis-sabinic acid S1 (cis-2-carboxy-1-isopropylcyclopropylethanoic acid) from sabinene; limonic acid L1 (3-isopropenylhexanedioic acid), limononic acid L3 (3-isopropenyl-6-oxo-heptanoic acid), 7-hydroxy-limononic acid L6 (3-isopropenyl-7-hydroxy-6-oxoheptanoic acid), and 7-hydroxylimononic acid Lg{prime} (7-hydroxy-3-isopropenyl-6-oxoheptanoic acid) from limonene.

  18. Neuropsychological Outcomes in Fatty Acid Oxidation Disorders: 85 Cases Detected by Newborn Screening

    ERIC Educational Resources Information Center

    Waisbren, Susan E.; Landau, Yuval; Wilson, Jenna; Vockley, Jerry

    2013-01-01

    Mitochondrial fatty acid oxidation disorders include conditions in which the transport of activated acyl-Coenzyme A (CoA) into the mitochondria or utilization of these substrates is disrupted or blocked. This results in a deficit in the conversion of fat into energy. Most patients with fatty acid oxidation defects are now identified through…

  19. Oxidase-peroxidase enzymes of Datura innoxia. Oxidation of formylphenylacetic acid ethyl ester.

    PubMed Central

    Kalyanaraman, V S; Mahadevan, S; Kumar, S A

    1975-01-01

    An enzyme system from Datura innoxia roots oxidizing formylphenylacetic acid ethyl ester was purified 38-fold by conventional methods such as (NH4)2SO4 fractionation, negative adsorption on alumina Cy gel and chromatography on DEAE-cellulose. The purified enzyme was shown to catalyse the stoicheiometric oxidation of formylphenylacetic acid ethyl ester to benzoylformic acid ethyl ester and formic acid, utilizing molecular O2. Substrate analogues such as phenylacetaldehyde and phenylpyruvate were oxidized at a very low rate, and formylphenylacetonitrile was an inhilating agents, cyanide, thiol compounds and ascorbic acid. This enzyme was identical with an oxidase-peroxidase isoenzyme. Another oxidase-peroxidase isoenzyme which separated on DEAE-chromatography also showed formylphenylacetic acid ethyl ester oxidase activity, albeit to a lesser extent. The properties of the two isoenzymes of the oxidase were compared and shown to differ in their oxidation and peroxidation properties. The oxidation of formylphenylacetic acid ethyl ester was also catalysed by horseradish peroxidase. The Datura isoenzymes exhibited typical haemoprotein spectra. The oxidation of formylphenylacetic acid ethyl ester was different from other peroxidase-catalysed reactions in not being activated by either Mn2+ or monophenols. The oxidation was inhibited by several mono- and poly-phenols and by catalase. A reaction mechanism for the oxidation is proposed. PMID:997

  20. The Baeyer-Villiger Oxidation with Trifluoroacetic Acid and Household Sodium Percarbonate

    ERIC Educational Resources Information Center

    Kjonaas, Richard A.; Clemons, Anthony E.

    2008-01-01

    A method for carrying out the Baeyer-Villiger oxidation of cyclopentanone to [delta]-valerolactone in a large-section introductory organic chemistry laboratory course is reported. The oxidizing agent is trifluoroperoxyacetic acid generated in situ from trifluoroacetic acid and household sodium percarbonate such as OxiClean, Oxi Magic, or…

  1. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ester with pentaerythritol. 721.3680 Section 721.3680 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with... identified generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN P-91-442)...

  2. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ester with pentaerythritol. 721.3680 Section 721.3680 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.3680 Ethylene oxide adduct of fatty acid ester with... identified generically as ethylene oxide adduct of fatty acid ester with pentaerythritol (PMN P-91-442)...

  3. Activation of Nrf2-mediated oxidative stress response in macrophages by hypochlorous acid

    SciTech Connect

    Pi Jingbo Zhang Qiang; Woods, Courtney G.; Wong, Victoria; Collins, Sheila; Andersen, Melvin E.

    2008-02-01

    Hypochlorous acid (HOCl), a potent oxidant generated when chlorine gas reacts with water, is important in the pathogenesis of many disorders. Transcription factor Nrf2-mediated antioxidant response represents a critical cellular defense mechanism that serves to maintain intracellular redox homeostasis and limit oxidative damage. In the present study, the effect of HOCl on Nrf2 activation was investigated in macrophages, one of the target cells of chlorine gas exposure. Exposure of RAW 264.7 macrophages to HOCl resulted in increased protein levels of Nrf2 in nuclear extractions, as well as a time- and dose-dependent increase in the expression of Nrf2 target genes, including heme oxygenase-1, NAD(P)H:quinone oxidoreductase 1 (NQO-1), glutamate cysteine ligase catalytic subunit (GCLC), and glutathione synthetase (GS). Additionally, intracellular glutathione (GSH), which is the prime scavenger for HOCl in cells, decreased within the first hour of HOCl exposure. The decline was followed by a GSH rebound that surpassed the initial basal levels by up to 4-fold. This reversal in GSH levels closely correlated with the gene expression profile of GCLC and GS. To study the mechanisms of Nrf2 activation in response to HOCl exposure, we examined the effects of several antioxidants on Nrf2-mediated response. Pretreatment with cell-permeable catalase, N-acetyl-L-cysteine or GSH-monoethyl ester markedly reduced expression of NQO-1 and GCLC under HOCl challenge conditions, suggesting intracellular ROS-scavenging capacity affects HOCl-induced Nrf2 activation. Importantly, pre-activation of Nrf2 with low concentrations of pro-oxidants protected the cells against HOCl-induced cell damage. Taken together, we provide direct evidence that HOCl activates Nrf2-mediated antioxidant response, which protects cells from oxidative damage.

  4. 3-Nitropropionic acid induces ovarian oxidative stress and impairs follicle in mouse.

    PubMed

    Zhang, Jia-Qing; Shen, Ming; Zhu, Cheng-Cheng; Yu, Feng-Xiang; Liu, Ze-Qun; Ally, Nazim; Sun, Shao-Chen; Li, Kui; Liu, Hong-Lin

    2014-01-01

    Oxidative stress induces many serious reproductive diseases in female mammals and thus poses a serious threat to reproductive health. However, the relationship between reactive oxygen species (ROS)-induced oxidative stress and follicular development, oocyte and embryo quality is not clear. The aim of this study was to investigate the effect of ovarian oxidative stress on the health of follicle and oocyte development. Female ICR mice were dosed with 3-nitropropionic acid (3-NPA) at three different concentrations (6.25, 12.5 and 25 mg/kg) and saline (control) via continuous intraperitoneal injection for 7 days. The treatment with 12.5 mg/kg reduced the weight of mouse ovaries, and significantly increased ROS levels and the activities of antioxidant enzymes--total superoxide dismutase (T-SOD), glutathione peroxidase (GPx) and catalase (CAT)--in granulosa cells and ovarian tissues, but not in other tissues (brain, liver, kidney and spleen). The same treatment significantly increased the percentage of atretic large follicles, and reduced the number of large follicles, the number of ovulated oocytes, and the capacity for early embryonic development compared with controls. It also significantly decreased the ratio of Bcl-2 to Bax, while causing an increase in the mRNA expression of (SOD2, CAT and GP X) and ROS levels in granulosa cells. Collectively, these data indicate that 3-NPA induces granulosa cell apoptosis, large follicle atresia, and an increase of ROS levels in the ovary. Therefore, we have established an in vivo model of ovarian oxidative stress for studying the mechanism of resulting damage induced by free radicals and for the screening of novel antioxidants. PMID:24505260

  5. 3-Nitropropionic Acid Induces Ovarian Oxidative Stress and Impairs Follicle in Mouse

    PubMed Central

    Zhang, Jia-Qing; Shen, Ming; Zhu, Cheng-Cheng; Yu, Feng-Xiang; Liu, Ze-Qun; Ally, Nazim; Sun, Shao-Chen; Li, Kui; Liu, Hong-Lin

    2014-01-01

    Oxidative stress induces many serious reproductive diseases in female mammals and thus poses a serious threat to reproductive health. However, the relationship between reactive oxygen species (ROS)—induced oxidative stress and follicular development, oocyte and embryo quality is not clear. The aim of this study was to investigate the effect of ovarian oxidative stress on the health of follicle and oocyte development. Female ICR mice were dosed with 3-nitropropionic acid (3-NPA) at three different concentrations (6.25, 12.5 and 25 mg/kg) and saline (control) via continuous intraperitoneal injection for 7 days. The treatment with 12.5 mg/kg reduced the weight of mouse ovaries, and significantly increased ROS levels and the activities of antioxidant enzymes—total superoxide dismutase (T-SOD), glutathione peroxidase (GPx) and catalase (CAT) — in granulosa cells and ovarian tissues, but not in other tissues (brain, liver, kidney and spleen). The same treatment significantly increased the percentage of atretic large follicles, and reduced the number of large follicles, the number of ovulated oocytes, and the capacity for early embryonic development compared with controls. It also significantly decreased the ratio of Bcl-2 to Bax, while causing an increase in the mRNA expression of (SOD2, CAT and GPX) and ROS levels in granulosa cells. Collectively, these data indicate that 3-NPA induces granulosa cell apoptosis, large follicle atresia, and an increase of ROS levels in the ovary. Therefore, we have established an in vivo model of ovarian oxidative stress for studying the mechanism of resulting damage induced by free radicals and for the screening of novel antioxidants. PMID:24505260

  6. Measurement of β-oxidation capacity of biological samples by respirometry: a review of principles and substrates.

    PubMed

    Ojuka, Edward; Andrew, Brittany; Bezuidenhout, Nicole; George, Siddiqah; Maarman, Gerald; Madlala, Hlengiwe P; Mendham, Amy; Osiki, Prisca Ofure

    2016-05-01

    Oxidation of fatty acids is a major source of energy in the heart, liver, and skeletal muscle. It can be measured accurately using respirometry in isolated mitochondria, intact cells, and permeabilized cells or tissues. This technique directly measures the rate of oxygen consumption or flux at various respiratory states when appropriate substrates, uncouplers, and inhibitors are used. Acylcarnitines such as palmitoylcarnitine or octanoylcarnitine are the commonly used substrates. The β-oxidation pathway is prone to feedforward inhibition resulting from accumulation of short-chain acyl-CoA and depletion of CoA, but inclusion of malate or carnitine prevents accumulation of these intermediaries and CoA depletion. PMID:26908505

  7. Effect of low glycemic index food and postprandial exercise on blood glucose level, oxidative stress and antioxidant capacity

    PubMed Central

    KASUYA, NORIAKI; OHTA, SHOICHIRO; TAKANAMI, YOSHIKAZU; KAWAI, YUKARI; INOUE, YUTAKA; MURATA, ISAMU; KANAMOTO, IKUO

    2015-01-01

    Low glycemic index (GI) food and postprandial exercise are non-drug therapies for improving postprandial hyperglycemia. The present randomized, crossover study investigated the effect of low GI food combined with postprandial exercise on postprandial blood glucose level, oxidative stress and antioxidant capacity. A total of 13 healthy subjects were each used in four experiments: i) rice only (control), ii) salad prior to rice (LGI), iii) exercise following rice (EX) and iv) salad prior to rice and exercise following rice (MIX). The blood glucose level, oxidative stress and antioxidant capacity were then measured. At 60 min after the meal, the blood glucose level was observed to be increased in the MIX group compared with that in the LGI group. Furthermore, at 180 min, the antioxidant capacity was found to be reduced in the MIX group compared with those of the LGI and EX groups. These findings suggest that low GI food combined with postprandial exercise does not improve postprandial hyperglycemia. It may be necessary to establish optimal timing and intensity when combining low GI food with postprandial exercise to improve postprandial hyperglycemia. PMID:25780409

  8. In vitro binding capacities of three dietary fibers and their mixture for four toxic elements, cholesterol, and bile acid.

    PubMed

    Zhang, Ning; Huang, Caihuan; Ou, Shiyi

    2011-02-15

    Water-soluble dietary fibers from apple peels and water-insoluble dietary fibers from wheat bran and soybean-seed hull were used to evaluate their binding capacities for four toxic elements (Pb, Hg, Cd, and As), lard, cholesterol, and bile acids. The water-soluble dietary fibers showed a higher binding capacity for three toxic cations, cholesterol, and sodium cholate; and a lower binding capacity for lard, compared to the water-insoluble ones. A mixture of the dietary fibers from all samples - apple peels, wheat bran, and soybean-seed hull - in the ratio 2:4:4 (w/w) significantly increased the binding capacity of water-insoluble dietary fibers for the three toxic cations, cholesterol, and sodium cholate; moreover, the mixture could lower the concentrations of Pb(2+) and Cd(+) in the tested solutions to levels lower than those occurring in rice and vegetables grown in polluted soils. However, all the tested fibers showed a low binding capacity for the toxic anion, AsO(3)(3-). PMID:21095057

  9. Hepatic drug-oxidizing enzyme systems and urinary D-glucaric acid excretion in patients with congestive heart failure.

    PubMed Central

    Tokola, O; Pelkonen, O; Karki, N T; Luoma, P

    1975-01-01

    Drug-oxidizing enzyme systems in liver biopsy samples and the urinary excretion of D-glucaric acid were studied in two different groups of patients with cardiac insufficiency. 2. In one group of six patients, the activities of drug-metabolizing enzymes had decreased considerably as compared with the control values, but in four liver samples from patients treated with oral hypoglycaemic agents for their diabetes, activities were higher than in control samples from ten patients. 3. In the other group of seven patients, the urinary excretion of D-glucaric acid (isolated by ion-exchange chromatography) was 60% lower than in the control group of nine humans, whereas in four patients taking antiepileptic agents excretion rate was higher than control values. 4. Because the age distribution was markedly different between cardiac insufficiency and control groups, it is difficult to conclude, if the impairment of drug metabolism was a consequence of the old age or of the disease process. However, drug-oxidizing enzyme systems seem to be inducible also in old age. 5. The results support further the opinion that the urinary excretion of D-glucaric acid may be one useful index in assessing an individual's capacity to metabolize foreign compounds especially in the patients with lowered drug metabolizing capacity. PMID:786355

  10. Cimicifuga racemosa impairs fatty acid β-oxidation and induces oxidative stress in livers of ovariectomized rats with renovascular hypertension.

    PubMed

    Campos, Lilian Brites; Gilglioni, Eduardo Hideo; Garcia, Rosângela Fernandes; Brito, Márcia do Nascimento; Natali, Maria Raquel Marçal; Ishii-Iwamoto, Emy Luiza; Salgueiro-Pagadigorria, Clairce Luzia

    2012-08-15

    The aim of this work was to evaluate the effects of therapeutic doses of Cimicifuga racemosa on cardiovascular parameters and on liver lipid metabolism and redox status in an animal model of estrogen deficiency associated with hypertension, a condition that could make the liver more vulnerable to drug-induced injuries. Female Wistar rats were subjected to the surgical procedures of bilateral ovariectomy (OVX) and induction of renovascular hypertension (two-kidneys, one-clip; 2K1C). These animals (OVX + 2K1C) were treated with daily doses of a C. racemosa extract, using a dose that is similar to that recommended to postmenopausal women (0.6 mg/kg), over a period of 15 days. The results were compared to those of untreated OVX + 2K1C, OVX, and control rats. The treatment with C. racemosa caused a significant reduction in blood pressure. In the liver, treatment did not prevent the development of steatosis, and it reduced the mitochondrial and peroxisomal capacity to oxidize octanoyl-CoA compared to the untreated animals. In addition, C. racemosa caused numerous undesirable effects on the liver redox status: it increased the mitochondrial reactive oxygen species generation, an event that was not accompanied by an increase in the activity of superoxide dismutase, and it induced a decrease in peroxisomal catalase activity. Although the reduced glutathione content had not been affected, a phenomenon that probably reflected the restoration of glucose-6-phosphate dehydrogenase activity by C. racemosa, oxidative damage was evidenced by the elevated level of thiobarbituric acid-reactive substances found in the liver of treated animals. PMID:22684021

  11. Aerobic bacterial pyrite oxidation and acid rock drainage during the Great Oxidation Event.

    PubMed

    Konhauser, Kurt O; Lalonde, Stefan V; Planavsky, Noah J; Pecoits, Ernesto; Lyons, Timothy W; Mojzsis, Stephen J; Rouxel, Olivier J; Barley, Mark E; Rosìere, Carlos; Fralick, Phillip W; Kump, Lee R; Bekker, Andrey

    2011-10-20

    The enrichment of redox-sensitive trace metals in ancient marine sedimentary rocks has been used to determine the timing of the oxidation of the Earth's land surface. Chromium (Cr) is among the emerging proxies for tracking the effects of atmospheric oxygenation on continental weathering; this is because its supply to the oceans is dominated by terrestrial processes that can be recorded in the Cr isotope composition of Precambrian iron formations. However, the factors controlling past and present seawater Cr isotope composition are poorly understood. Here we provide an independent and complementary record of marine Cr supply, in the form of Cr concentrations and authigenic enrichment in iron-rich sedimentary rocks. Our data suggest that Cr was largely immobile on land until around 2.48 Gyr ago, but within the 160 Myr that followed--and synchronous with independent evidence for oxygenation associated with the Great Oxidation Event (see, for example, refs 4-6)--marked excursions in Cr content and Cr/Ti ratios indicate that Cr was solubilized at a scale unrivalled in history. As Cr isotope fractionations at that time were muted, Cr must have been mobilized predominantly in reduced, Cr(III), form. We demonstrate that only the oxidation of an abundant and previously stable crustal pyrite reservoir by aerobic-respiring, chemolithoautotrophic bacteria could have generated the degree of acidity required to solubilize Cr(III) from ultramafic source rocks and residual soils. This profound shift in weathering regimes beginning at 2.48 Gyr ago constitutes the earliest known geochemical evidence for acidophilic aerobes and the resulting acid rock drainage, and accounts for independent evidence of an increased supply of dissolved sulphate and sulphide-hosted trace elements to the oceans around that time. Our model adds to amassing evidence that the Archaean-Palaeoproterozoic boundary was marked by a substantial shift in terrestrial geochemistry and biology. PMID:22012395

  12. The smoking-associated oxidant hypothiocyanous acid induces endothelial nitric oxide synthase dysfunction.

    PubMed

    Talib, Jihan; Kwan, Jair; Suryo Rahmanto, Aldwin; Witting, Paul K; Davies, Michael J

    2014-01-01

    Smokers have an elevated risk of cardiovascular disease but the origin(s) of this increased risk are incompletely defined. Considerable evidence supports an accumulation of the oxidant-generating enzyme MPO (myeloperoxidase) in the inflamed artery wall, and smokers have high levels of SCN(-), a preferred MPO substrate, with this resulting in HOSCN (hypothiocyanous acid) formation. We hypothesized that this thiol-specific oxidant may target the Zn(2+)-thiol cluster of eNOS (endothelial nitric oxide synthase), resulting in enzyme dysfunction and reduced formation of the critical signalling molecule NO•. Decreased NO• bioavailability is an early and critical event in atherogenesis, and HOSCN-mediated damage to eNOS may contribute to smoking-associated disease. In the present study it is shown that exposure of isolated eNOS to HOSCN or MPO/H2O2/SCN(-) decreased active dimeric eNOS levels, and increased inactive monomer and Zn(2+) release, compared with controls, HOCl (hypochlorous acid)- or MPO/H2O2/Cl(-)-treated samples. eNOS activity was increasingly compromised by MPO/H2O2/Cl(-) with increasing SCN(-) concentrations. Exposure of HCAEC (human coronary artery endothelial cell) lysates to pre-formed HOSCN, or MPO/H2O2/Cl(-) with increasing SCN(-), increased eNOS monomerization and Zn(2+) release, and decreased activity. Intact HCAECs exposed to HOCl and HOSCN had decreased eNOS activity and NO2(-)/NO3(-) formation (products of NO• decomposition), and increased free Zn(2+). Exposure of isolated rat aortic rings to HOSCN resulted in thiol loss, and decreased eNOS activity and cGMP levels. Overall these data indicate that high SCN(-) levels, as seen in smokers, can increase HOSCN formation and enhance eNOS dysfunction in human endothelial cells, with this potentially contributing to increased atherogenesis in smokers. PMID:24112082

  13. Hydrogen peroxide use to increase oxidant capacity for in situ bioremediation of contaminated soils and aquifers: A review

    NASA Astrophysics Data System (ADS)

    Pardieck, Daniel L.; Bouwer, Edward J.; Stone, Alan T.

    1992-03-01

    Biotransformation of organic pollutants is often most effective and complete under oxic or oxidant-rich conditions. Dissolved oxygen availability is frequently limiting the biotransformation of these organic compounds in the subsurface due to the limited aqueous solubility of oxygen, the relatively slow rate of re-aeration of groundwater in the saturated zone, and the significant biological oxygen demand exerted during aerobic metabolism. Addition of hydrogen peroxide (H 2O 2) can augment the oxidant capacity of the aquifer. This paper reviews several reactions pertinent to remediating contaminated groundwaters via H 2O 2 addition. H 2O 2 is disproportioned by the action of microbial catalase and several inorganic catalysts such as iron oxide species to give 0.5 mol O 2 per mole of H 2O 2 consumed. The resulting dissolved oxygen should then be available for microbial respiration. If disproportionation occurs too quickly, evolution of oxygen gas can form bubles that lower aquifer permeability. Another type of reaction is direct oxidation of organic compounds by H 2O 2 in the presence of enzymes (peroxidases) or metal oxide catalysts. Molecular oxygen is not evolved as a result of this type of H 2O 2-consuming reaction. Modifications in treatment strategy may also be necessary to minimize H 2O 2 toxicity as H 2O 2 is known to be toxic at a concentration within the cell of 0.1 m M.

  14. Soil Oxidation-Reduction Potential and Plant Photosynthetic Capacity in the Northern Pantanal of Mato Grosso, Brazil

    NASA Astrophysics Data System (ADS)

    Lathuilliere, M. J.; Johnson, M. S.; Dalmagro, H. J.; Pinto Junior, O. B.; Couto, E. G.

    2013-12-01

    Plant communities of the Pantanal wetland are able to survive long periods of climatic and physiological stress in the dry and wet seasons. During inundation, soil oxygen demand increases dramatically as reducing soil conditions create stress in the root system with possible impacts on photosynthetic capacity of plants. We look at inundation cycles of a tree island (locally known as a cordilheira) in the Northern Pantanal near Poconé, Mato Grosso, and relate soil oxidation-reduction potential and soil oxygen depletion to the photosynthetic capacity of two plant communities of flooded scrub forest (Vochysia divergens and Curatela americana). Results show a drop in soil oxidation-reduction potential of over 400 mV, to levels below the absolute value of -200 mV, following inundation around the tree island. Both plant species showed increased carbon assimilation at highest soil oxygen demand despite a change in stomatal conductance, suggesting adaptation to the inundated environment. Absolute values of soil oxidation-reduction potential also allow for the determination of specific soil chemical reactions characteristic of the tree island environment, namely the reduction of iron(III), or carbon dioxide which in turn produces methane. Our combined analysis of soil chemistry with plant ecophysiology allows for a better understanding of soil-plant interactions in the Pantanal, specifically the drivers of biogeochemical processes between inundation periods.

  15. Contrasts in spatial and temporal variability of oxidative capacity and elemental composition in moxibustion, indoor and outdoor environments in Beijing.

    PubMed

    Huang, Jian; Lim, Min Yee; Hwang, Chaxi; Zhao, Baixiao; Shao, Longyi

    2015-07-01

    Moxibustion is a traditional Chinese medicine therapy that burns moxa floss which produces a substantial amount of PM10 into the environment, thus spawning safety concerns about health impacts of the smoke. We compared the oxidative capacity and elemental composition of moxibustion-derived and ambient PM10 in summer and winter to provide a source-, spatial- and temporal-comparison of PM10 biological responses. The PM10 oxidative capacity was 2.04 and 1.45 fold lower, and dose-dependent slope gradient was 2.36 and 1.76 fold lower in moxibustion environment than indoor or outdoor. Oxidative damage was highly correlated with iron, cesium, aluminum and cobalt in indoor, but moxibustion environment displayed low associations. The total elemental concentration was also lower in moxibustion environment than indoor (2.28 fold) or outdoor (2.79 fold). The source-to-dose modeling and slope gradient analysis in this study can be used as a model for future source-, spatial- and temporal-related moxibustion safety evaluation studies. PMID:25818086

  16. Effect of Cattle Breed on Meat Quality, Muscle Fiber Characteristics, Lipid Oxidation and Fatty Acids in China

    PubMed Central

    Xie, Xiangxue; Meng, Qingxiang; Cui, Zhenliang; Ren, Liping

    2012-01-01

    The objective was to compare meat quality, muscle fiber characteristics, lipid oxidation and fatty acids of Limousin (LIM), Simmtental (SIM), Luxi (LX), Qinchuan (QC) and Jinnan (JN) offered the same diet in China. After finishing, eight bulls from each breed were randomly selected for slaughter at 18.5 months old. Longissimus dorsi (ld) muscle was taken from the carcass for meat quality evaluations. Breed had little effect on most of meat and fat color parameters except for Hue and b* in which QC had lower values. LIM showed higher pH (24 h) and better water holding capacity than other breeds. LIM showed the lowest dry matter content but the highest crude protein. LX and LIM had higher percentage and density of red muscle fiber than other breeds. Lipid oxidations were significantly lower in LIM than in QC, with the LX, SIM and JN having the intermediate values. Compared to other four breeds, QC provided the highest values of polyunsaturated fatty acids (PUFA), n-6 fatty acids and n-3 fatty acids. In conclusion, LIM scored better on most of meat quality characteristics; however, local breeds such as LX and QC also had better muscle fiber characteristics and better fatty acids composition. PMID:25049633

  17. Protective Effect of Folic Acid on Oxidative DNA Damage

    PubMed Central

    Guo, Xiaojuan; Cui, Huan; Zhang, Haiyang; Guan, Xiaoju; Zhang, Zheng; Jia, Chaonan; Wu, Jia; Yang, Hui; Qiu, Wenting; Zhang, Chuanwu; Yang, Zuopeng; Chen, Zhu; Mao, Guangyun

    2015-01-01

    Abstract Although previous reports have linked DNA damage with both transmissions across generations as well as our own survival, it is unknown how to reverse the lesion. Based on the data from a Randomized, Double-blind, Placebo Controlled Clinical Trial, this study aimed to assess the efficacy of folic acid supplementation (FAS) on DNA oxidative damage reversal. In this randomized clinical trial (RCT), a total of 450 participants were enrolled and randomly assigned to 3 groups to receive folic acid (FA) 0.4 mg/day (low-FA), 0.8 mg/day (high-FA), or placebo (control) for 8 weeks. The urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG) and creatinine (Cr) concentration at pre- and post-FAS were measured with modified enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), respectively. A multivariate general linear model was applied to assess the individual effects of FAS and the joint effects between FAS and hypercholesterolemia on oxidative DNA damage improvement. This clinical trial was registered with ClinicalTrials.gov, number NCT02235948. Of the 438 subjects that received FA fortification or placebo, the median (first quartile, third quartile) of urinary 8-OHdG/Cr for placebo, low-FA, and high-FA groups were 58.19 (43.90, 82.26), 53.51 (38.97, 72.74), 54.73 (39.58, 76.63) ng/mg at baseline and 57.77 (44.35, 81.33), 51.73 (38.20, 71.30), and 50.65 (37.64, 76.17) ng/mg at the 56th day, respectively. A significant decrease of urinary 8-OHdG was observed after 56 days FA fortification (P < 0.001). Compared with the placebo, after adjusting for some potential confounding factors, including the baseline urinary 8-OHdG/Cr, the urinary 8-OHdG/Cr concentration significantly decreased after 56 days FAS [β (95% confidence interval) = −0.88 (−1.62, −0.14) and P = 0.020 for low-FA; and β (95% confidence interval) = −2.68 (−3.42, −1.94) and P < 0.001 for high-FA] in a dose-response fashion (Ptrend

  18. Influence of fatty acid on lipase-catalyzed synthesis of ascorbyl esters and their free radical scavenging capacity.

    PubMed

    Stojanović, Marija; Carević, Milica; Mihailović, Mladen; Veličković, Dušan; Dimitrijević, Aleksandra; Milosavić, Nenad; Bezbradica, Dejan

    2015-01-01

    Fatty acid (FA) ascorbyl esters are recently emerging food, cosmetic, and pharmaceutical additives, which can be prepared in an eco-friendly way by using lipases as catalysts. Because they are amphiphilic molecules, which possess high free radical scavenging capacity, they can be applied as liposoluble antioxidants as well as emulsifiers and biosurfactants. In this study, the influence of a wide range of acyl donors on ester yield in lipase-catalyzed synthesis and ester antioxidant activity was examined. Among saturated acyl donors, higher yields and antioxidant activities of esters were achieved when short-chain FAs were used. Oleic acid gave the highest yield overall and its ester exhibited a high antioxidant activity. Optimization of experimental factors showed that the highest conversion (60.5%) in acetone was achieved with 5 g L(-1) of lipase, 50 mM of vitamin C, 10-fold molar excess of oleic acid, and 0.7 mL L(-1) of initial water. Obtained results showed that even short- and medium-chain ascorbyl esters could be synthesized with high yields and retained (or even exceeded) free radical scavenging capacity of l-ascorbic acid, indicating prospects of broadening their application in emulsions and liposomes. PMID:25224149

  19. Interference by morpholine ethanesulfonic acid (MES) and related buffers in phenolic oxidation by peroxidase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While characterizing the kinetic parameters of apoplastic phenolic oxidation by peroxidase, we found anomalies caused by the 4-morpholine ethanesulfonic acid (MES) buffer being used. In the presence of MES, certain phenolics appeared not to be oxidized by peroxidase, yet the oxidant, H2O2, was uti...

  20. YME1L degradation reduces mitochondrial proteolytic capacity during oxidative stress

    PubMed Central

    Rainbolt, T Kelly; Saunders, Jaclyn M; Wiseman, R Luke

    2015-01-01

    Mitochondrial proteostasis is maintained by a network of ATP-dependent quality control proteases including the inner membrane protease YME1L. Here, we show that YME1L is a stress-sensitive mitochondrial protease that is rapidly degraded in response to acute oxidative stress. This degradation requires reductions in cellular ATP and involves the activity of the ATP-independent protease OMA1. Oxidative stress-dependent reductions in YME1L inhibit protective YME1L-dependent functions and increase cellular sensitivity to oxidative insult. Collectively, our results identify stress-induced YME1L degradation as a biologic process that attenuates protective regulation of mitochondrial proteostasis and promotes cellular death in response to oxidative stress. PMID:25433032

  1. The mechanisms governing low denitrification capacity and high nitrogen oxide gas emissions in subtropical forest soils in China

    NASA Astrophysics Data System (ADS)

    Zhang, Jinbo; Yu, Yongjie; Zhu, Tongbin; Cai, Zucong

    2014-08-01

    Previous studies have demonstrated that denitrification rates are low in subtropical forest soils. However, the mechanisms governing this process are not well known. This study seeks to identify the mechanisms responsible for the low denitrification capacity and high nitrogen oxide gas ratio in subtropical forest soils in China. The denitrification capacity and nitric oxide (NO), nitrous oxide (N2O), and dinitrogen (N2) emission rates were measured using the acetylene inhibition method under conditions of added nitrate and anoxia. The abundance of nitrate reductase (narG), nitrite reductase (nirK), nitric oxide reductase (cnorB), and nitrous oxide reductase (nosZ) was measured using real-time, quantitative polymerase chain reaction, and sequencing of the nirK and norB products was performed to analyze the population structure of denitrifying bacteria. These results showed that the denitrification capacity in subtropical forest soils was lower than in temperate forest soils (p < 0.05). Multiple regression analysis showed that redox potential at the start of incubation (Ehi), rather than soil pH or soil organic C, was the key soil variable influencing denitrification, and Ehi alone could explain 68% of the variations in denitrification capacity. The high Ehi in subtropical soils led to a low abundance of nirK and significant differences in the population structure of denitrifying bacteria between subtropical and temperate soils. Therefore, Ehi was responsible for the low denitrification capacity in subtropical forest soils. The ratio of NO to total denitrification gas products (p < 0.01) and the ratio of NO and N2O to total denitrification gas products (p < 0.05) were significantly higher in subtropical forest soils than in temperate forest soils, while the reverse trend was observed for the ratio of N2 to total denitrification gas products (p < 0.05). A high Ehi reduced the specific reduction activity of each nosZ copy and, in turn, resulted in a large ratio of NO

  2. Current issues regarding treatment of mitochondrial fatty acid oxidation disorders.

    PubMed

    Spiekerkoetter, Ute; Bastin, Jean; Gillingham, Melanie; Morris, Andrew; Wijburg, Frits; Wilcken, Bridget

    2010-10-01

    Treatment recommendations in mitochondrial fatty acid oxidation (FAO) defects are diverse. With implementation of newborn screening and identification of asymptomatic patients, it is necessary to define whom to treat and how strictly. We here discuss critical questions that are currently under debate. For some asymptomatic long-chain defects, long-chain fat restriction plays a minor role, and a normal diet may be introduced. For patients presenting only with myopathic symptoms, e.g., during exercise, treatment may be adapted to energy demand. As a consequence, patients with exercise-induced myopathy may be able to return to normal activity when provided with medium-chain triglycerides (MCT) prior to exercise. There is no need to limit participation in sports. Progression of retinopathy in disorders of the mitochondrial trifunctional protein complex is closely associated with hydroxyacylcarnitine accumulation. A strict low-fat diet with MCT supplementation is recommended to slow or prevent progression of chorioretinopathy. Additional docosahexanoic acid does not prevent the decline in retinal function but does promote nonspecific improvement in visual acuity and is recommended. There is no evidence that L-carnitine supplementation is beneficial. Thus, supplementation with L-carnitine in a newborn identified by screening with either a medium-chain or long-chain defect is not supported. With respect to the use of the odd-chain medium-chain triglyceride triheptanoin in myopathic phenotypes, randomized trials are needed to establish whether triheptanoin is more effective than even-chain MCT. With increasing pathophysiological knowledge, new treatment options have been identified and are being clinically evaluated. These include the use of bezafibrates in myopathic long-chain defects. PMID:20830526

  3. Effect of day length on oxidative capacities of mitochondria from red muscle of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Martin, Nicolas; Kraffe, Edouard; Guderley, Helga

    2009-04-01

    In nature, seasons may be more reliably announced by changes in photoperiod than in temperature. To evaluate the role of day length in setting oxidative capacities of trout muscle mitochondria, we acclimated trout to summer (15 degrees C, 16L:8D), winter (5 degrees C, 8L:16D) and mixed conditions (15 degrees C, 8L:16D). Maximal oxidative capacities of isolated mitochondria at 5 and 15 degrees C were higher in mixed than summer conditions and higher again in winter conditions. At 5 degrees C, state 4 rates changed little with acclimation state whereas at 15 degrees C state 4 rates were lower in summer than in mixed or winter conditions. Using concentrations of the adenylate nucleotide translocase as the denominator for these rates gave much the same conclusions. By using inhibitors to block flux at specific points in the electron transport chain, we found that flux through Complexes II-IV was lowest in summer acclimated trout, increased upon acclimation to mixed and to winter conditions. Flux through complex IV was similar in trout acclimated to summer and mixed conditions, but increased significantly with acclimation to winter conditions. Flux through complex IV was 1.5 fold higher than state 3 rates for summer-acclimated trout but was similar to state 3 rates in trout acclimated to mixed or winter conditions. Our results indicate that a reduction in day length initiates increases in mitochondrial oxidative capacity typically associated with cold acclimation and that acclimation to both cold temperatures and short day lengths enhanced these changes. The overall similarity of the responses of state 3, of flux through complexes II-IV and of flux through complex IV suggests that a generalised mechanism such as changes in the phospholipid composition of the inner mitochondrial membrane may coordinate these changes. PMID:19256041

  4. Oxidative capacity of the Mexico City atmosphere - Part 1: A radical source perspective

    NASA Astrophysics Data System (ADS)

    Volkamer, R.; Sheehy, P.; Molina, L. T.; Molina, M. J.

    2010-07-01

    A detailed analysis of OH, HO2 and RO2 radical sources is presented for the near field photochemical regime inside the Mexico City Metropolitan Area (MCMA). During spring of 2003 (MCMA-2003 field campaign) an extensive set of measurements was collected to quantify time-resolved ROx (sum of OH, HO2, RO2) radical production rates from day- and nighttime radical sources. The Master Chemical Mechanism (MCMv3.1) was constrained by measurements of (1) concentration time-profiles of photosensitive radical precursors, i.e., nitrous acid (HONO), formaldehyde (HCHO), ozone (O3), glyoxal (CHOCHO), and other oxygenated volatile organic compounds (OVOCs); (2) respective photolysis-frequencies (J-values); (3) concentration time-profiles of alkanes, alkenes, and aromatic VOCs (103 compound are treated) and oxidants, i.e., OH- and NO3 radicals, O3; and (4) NO, NO2, meteorological and other parameters. The ROx production rate was calculated directly from these observations; the MCM was used to estimate further ROx production from unconstrained sources, and express overall ROx production as OH-equivalents (i.e., taking into account the propagation efficiencies of RO2 and HO2 radicals into OH radicals). Daytime radical production is found to be about 10-25 times higher than at night; it does not track the abundance of sunlight. 12-h average daytime contributions of individual sources are: Oxygenated VOC other than HCHO about 33%; HCHO and O3 photolysis each about 20%; O3/alkene reactions and HONO photolysis each about 12%, other sources <3%. Nitryl chloride photolysis could potentially contribute ~15% additional radicals, while NO2* + water makes - if any - a very small contribution (~2%). The peak radical production of ~7.5 107 molec cm-3 s-1 is found already at 10:00 a.m., i.e., more than 2.5 h before solar noon. O3/alkene reactions are indirectly responsible for ~33% of these radicals. Our measurements and analysis comprise a database that enables testing of the representation of

  5. NOVEL POLY-GLUTAMIC ACID FUNCTIONALIZED MICROFILTRATION MEMBRANES FOR SORPTION OF HEAVY METALS AT HIGH CAPACITY

    EPA Science Inventory

    Various sorbent/ion exchange materials have been reported in the literature for metal ion entrapment. We have developed a highly innovative and new approach to obtain high metal pick-up utilizing poly-amino acids (poly-L-glutamic acid, 14,000 MW) covalently attached to membrane p...

  6. Reduction of hydrogen peroxide stress derived from fatty acid beta-oxidation improves fatty acid utilization in Escherichia coli.

    PubMed

    Doi, Hidetaka; Hoshino, Yasushi; Nakase, Kentaro; Usuda, Yoshihiro

    2014-01-01

    Fatty acids are a promising raw material for substance production because of their highly reduced and anhydrous nature, which can provide higher fermentation yields than sugars. However, they are insoluble in water and are poorly utilized by microbes in industrial fermentation production. We used fatty acids as raw materials for L-lysine fermentation by emulsification and improved the limited fatty acid-utilization ability of Escherichia coli. We obtained a fatty acid-utilizing mutant strain by laboratory evolution and demonstrated that it expressed lower levels of an oxidative-stress marker than wild type. The intracellular hydrogen peroxide (H₂O₂) concentration of a fatty acid-utilizing wild-type E. coli strain was higher than that of a glucose-utilizing wild-type E. coli strain. The novel mutation rpsA(D210Y) identified in our fatty acid-utilizing mutant strain enabled us to promote cell growth, fatty-acid utilization, and L-lysine production from fatty acid. Introduction of this rpsA(D210Y) mutation into a wild-type strain resulted in lower H₂O₂ concentrations. The overexpression of superoxide dismutase (sodA) increased intracellular H₂O₂ concentrations and inhibited E. coli fatty-acid utilization, whereas overexpression of an oxidative-stress regulator (oxyS) decreased intracellular H₂O₂ concentrations and promoted E. coli fatty acid utilization and L-lysine production. Addition of the reactive oxygen species (ROS) scavenger thiourea promoted L-lysine production from fatty acids and decreased intracellular H₂O₂ concentrations. Among the ROS generated by fatty-acid β-oxidation, H₂O₂ critically affected E. coli growth and L-lysine production. This indicates that the regression of ROS stress promotes fatty acid utilization, which is beneficial for fatty acids used as raw materials in industrial production. PMID:24169950

  7. Quantitative analysis of amino acid oxidation and related gluconeogenesis in humans.

    PubMed

    Jungas, R L; Halperin, M L; Brosnan, J T

    1992-04-01

    Significant gaps remain in our knowledge of the pathways of amino acid catabolism in humans. Further quantitative data describing amino acid metabolism in the kidney are especially needed as are further details concerning the pathways utilized for certain amino acids in liver. Sufficient data do exist to allow a broad picture of the overall process of amino acid oxidation to be developed along with approximate quantitative assessments of the role played by liver, muscle, kidney, and small intestine. Our analysis indicates that amino acids are the major fuel of liver, i.e., their oxidative conversion to glucose accounts for about one-half of the daily oxygen consumption of the liver, and no other fuel contributes nearly so importantly. The daily supply of amino acids provided in the diet cannot be totally oxidized to CO2 in the liver because such a process would provide far more ATP than the liver could utilize. Instead, most amino acids are oxidatively converted to glucose. This results in an overall ATP production during amino acid oxidation very nearly equal to the ATP required to convert amino acid carbon to glucose. Thus gluconeogenesis occurs without either a need for ATP from other fuels or an excessive ATP production that could limit the maximal rate of the process. The net effect of the oxidation of amino acids to glucose in the liver is to make nearly two-thirds of the total energy available from the oxidation of amino acids accessible to peripheral tissues, without necessitating that peripheral tissues synthesize the complex array of enzymes needed to support direct amino acid oxidation. As a balanced mixture of amino acids is oxidized in the liver, nearly all carbon from glucogenic amino acids flows into the mitochondrial aspartate pool and is actively transported out of the mitochondria via the aspartate-glutamate antiport linked to proton entry. In the cytoplasm the aspartate is converted to fumarate utilizing urea cycle enzymes; the fumarate flows via

  8. Visualization of O-O peroxo-like dimers in high-capacity layered oxides for Li-ion batteries.

    PubMed

    McCalla, Eric; Abakumov, Artem M; Saubanère, Matthieu; Foix, Dominique; Berg, Erik J; Rousse, Gwenaelle; Doublet, Marie-Liesse; Gonbeau, Danielle; Novák, Petr; Van Tendeloo, Gustaaf; Dominko, Robert; Tarascon, Jean-Marie

    2015-12-18

    Lithium-ion (Li-ion) batteries that rely on cationic redox reactions are the primary energy source for portable electronics. One pathway toward greater energy density is through the use of Li-rich layered oxides. The capacity of this class of materials (>270 milliampere hours per gram) has been shown to be nested in anionic redox reactions, which are thought to form peroxo-like species. However, the oxygen-oxygen (O-O) bonding pattern has not been observed in previous studies, nor has there been a satisfactory explanation for the irreversible changes that occur during first delithiation. By using Li2IrO3 as a model compound, we visualize the O-O dimers via transmission electron microscopy and neutron diffraction. Our findings establish the fundamental relation between the anionic redox process and the evolution of the O-O bonding in layered oxides. PMID:26680196

  9. Oxidative degradation of bis (2,4,4-trimethylpentyl) dithiophosphinic acid in nitric acid studied by electrospray ionization mass spectrometry

    SciTech Connect

    G. S. Groenewold; D. R. Peterman

    2012-10-01

    Samples of bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex-301) were analyzed using direct infusion electrospray ionization mass spectrometry. Positive ion spectra of standard and stereo-pure acids displayed ions typical of the unmodified compound, cationized monomeric and dimeric cluster ion species. In addition, a significant ions 2 u less than the dimeric clusters were seen, that correspond to an oxidatively coupled species designated Cyx2 that is observed as H- or Na-cationized species in the electrospray analyses. Based on uncorrected ion intensities, Cyx2 is estimated to account for about 20% of the total in the standard materials. When samples that were contacted with 3 M HNO3 were analyzed, the positive ion spectrum consisted nearly entirely of ions derived from the oxidatively coupled product, indicating that the acid promotes coupling. The negative ion spectra of the standard acids consisted nearly entirely of the conjugate base that is formed by deprotonation of the acids, and cluster ions containing multiple acid molecules. The negative spectra of the HNO3-contacted samples also contained the conjugate base of the unmodified acid, but also two other species that correspond to the dioxo- and perthio- derivatives. It is concluded that HNO3 contact causes significant oxidation, forming at least three major products, Cyx2, the perthio-acid, and the dioxo-acid.

  10. Oxalic acid capped iron oxide nanorods as a sensing platform.

    PubMed

    Sharma, Anshu; Baral, Dinesh; Bohidar, H B; Solanki, Pratima R

    2015-08-01

    A label free impedimetric immunosensor has been fabricated using protein bovine serum albumin (BSA) and monoclonal antibodies against Vibrio cholerae (Ab) functionalized oxalic acid (OA) capped iron oxide (Fe3O4) nanorods for V. cholerae detection. The structural and morphological studies of Fe3O4 and OA-Fe3O4, were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS) techniques. The average crystalline size of Fe3O4, OA-Fe3O4 nanorods were obtained as about 29±1 and 39±1nm, respectively. The hydrodynamic radius of nanorods is found as 116nm (OA-Fe3O4) and 77nm (Fe3O4) by DLS measurement. Cytotoxicity of Fe3O4 and OA-Fe3O4 nanorods has been investigated in the presence of human epithelial kidney (HEK) cell line 293 using MTT assay. The cell viability and proliferation studies reveal that the OA-Fe3O4 nanorods facilitate cell growth. The results of electrochemical response studies of the fabricated BSA/Ab/OA-Fe2O3/ITO immunosensor exhibits good linearity in the range of 12.5-500ng mL(-1) with low detection limit of 0.5ng mL(-1), sensitivity 0.1Ωng(-1)ml(-1)cm(-2) and reproducibility more than 11 times. PMID:26048074

  11. Reduction of a phosphorus oxide and acid reaction set

    SciTech Connect

    Twarowski, A.

    1995-07-01

    It has been predicted for some time that hypersonic aircraft will suffer from diminished fuel efficiency due to the slow speed of radical recombination in the nozzle of the aircraft and the consequent expulsion of high-energy fragments during high Mach number flight. The addition of small amounts of phosphine combustion products (phosphorus oxides and acids) to water vapor has been found to result in a faster relaxation rate of OH to its equilibrium density following H{sub 2}O photolysis. This article describes the systematic construction of a reaction model of 162 phosphorus reactions among 17 phosphorus-containing species. Those reactions that contribute to the reestablishment of equilibrium following the perturbation of the system by H{sub 2}O photolysis or by an increase in temperature are identified. A thermodynamic free energy function is used to quantify the rate of system relaxation back to equilibrium for a series of 36 reaction conditions covering a temperature range of 1,500 to 3,000 K, a gas density range of 5 {times} 10{sup {minus}7} to 5 {times} 10{sup {minus}5} mol/cm{sup 3} and a fuel equivalence ratio of 0.8 to 1.2.

  12. Oxidation reaction of high molecular weight carboxylic acids in supercritical water.

    PubMed

    Jin, Fangming; Moriya, Takehiko; Enomoto, Heiji

    2003-07-15

    Stearic acid, being a model compound of high molecular weight carboxylic acids, was oxidized in a batch reactor by changing the oxygen supply with an insufficient oxygen supply at a constant reaction time at 420 degrees C. On the basis of the intermediate products identified by GC/MS, NMR, and HPLC analyses and the free-radical reaction mechanism, the oxidation pathways of high molecular weight carboxylic acids in supercritical water are discussed. The reaction of carboxylic acids in supercritical water proceeds with the consecutive oxidation of higher molecular weight carboxylic acids to lower molecular weight carboxylic acids through several major pathways. The attack of the hydroxyl radical occurs not only at the carbons in alpha-, beta-, gamma-positions to a --COOH group but also at the carbons ((omega-1)-carbon and/or omega-carbon) far in the alkyl chain from a --COOH group, which may lead to the formation of dicarboxylic acids. PMID:12901673

  13. Acidic properties of supported niobium oxide catalysts: An infrared spectroscopy investigation

    SciTech Connect

    Datka, J.; Turek, A.M.; Jehng, J.M.; Wachs, I.E. )

    1992-05-01

    Chemisorption of pyridine was applied as a method for studying the acidic properties of niobium pentoxide supported on silica, magnesia, alumina, titania, and zirconia. The infrared spectra of adsorbed pyridine were used to evaluate the concentration and the relative strength of Broensted and Lewis acid sites. Lewis acidity was found in all the supported niobium oxide systems, while Broensted acid sites were only detected for niobia supported on the alumina and silica supports. The origin and characteristics of the surface acid sites present in supported niobium oxide catalysts are discussed in the present study.

  14. Simultaneous determination of cation exchange capacity and surface area of acid activated bentonite powders by methylene blue sorption

    NASA Astrophysics Data System (ADS)

    Yener, Nilgün; Biçer, Cengiz; Önal, Müşerref; Sarıkaya, Yüksel

    2012-01-01

    To distinguish the ion exchanged and physically adsorbed methylene blue cations (MB+) on ionic surfaces, acid activated bentonite samples were used as porous adsorbents. A natural calcium bentonite (CaB) sample from Enez/Edirne, Turkey, was acid activated at 90 °C for 16 h with various HCl/CaB ratios. The irreversible exchange and physical adsorption of MB+ cations on the ionic solids have simultaneously occurred. The ion exchanged (mex) and physically adsorbed (mad) MB+ contents were obtained as the values of sorption capacity at c = 0 and the increase to a plateaus of adsorption isotherms, respectively. The mad value was taken to be monolayer adsorption capacity. Cation exchange capacity (CEC) and specific surface area (SMB) for each sample were calculated from the mex and mad values, respectively. Also, the BET specific surface areas (SBET) and pore size distribution were determined from low temperature nitrogen adsorption/desorption data. A linear correlation between the SMB and SBET values was found.

  15. Micelle-assisted signaling of peracetic acid by the oxidation of pyreneboronic acid via monomer-excimer switching.

    PubMed

    Choi, Jiyoung; Lee, Hyo Jin; Cho, Min Jeoung; Chang, Suk-Kyu

    2015-08-15

    A simple fluorescent probe for the industrial oxidant peracetic acid (PAA) was investigated. PAA-assisted oxidative conversion of pyrene-1-boronic acid into 1-hydroxypyrene was used as the signaling tool. Pyreneboronic acid was found to display selective signaling behavior, being more responsive to PAA than to other commonly used practical oxidants such as H2O2 and HOCl. The changes in pyrene monomer fluorescence to excimer were used in the quantitative analysis of PAA. When using the surfactant hexadecyltrimethylammonium bromide as a micellar additive, the signaling of PAA was markedly enhanced. Selective fluorescence signaling of PAA by pyrene-1-boronic acid with a detection limit of 1.5×10(-6)M in aqueous environment was successfully achieved. PMID:25966389

  16. Growth at Elevated Ozone or Elevated Carbon Dioxide Concentration Alters Antioxidant Capacity and Response to Acute Oxidative Stress in Soybean (Glycine max)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to test the hypothesis that atmospheric environment alters total antioxidant capacity of plants and their capacity to respond to acute oxidative stress, soybeans were grown under at elevated carbon dioxide concentration ([CO2]) or elevated ozone concentration ([O3]), and then exposed to an ...

  17. Cationic poly(lactic-co-glycolic acid) iron oxide microspheres for nucleic acid detection

    NASA Astrophysics Data System (ADS)

    Pandey, Chandra Mouli; Sharma, Aditya; Sumana, Gajjala; Tiwari, Ida; Malhotra, Bansi Dhar

    2013-04-01

    Herein, we envisage the possibility of preparing stable cationic poly(lactic-co-glycolic acid) (PLGA) microspheres encapsulating the iron oxide nanoparticles (IONPs; 8-12 nm). The IONPs are incorporated into PLGA in organic phase followed by microsphere formation and chitosan coating in aqueous medium via nano-emulsion technique. The average size of the microspheres, as determined by dynamic light scattering are about 310 nm, while the zeta potential for the composite remains near 35 mV at pH 4.0. These microspheres are electrophoretically deposited onto indium tin oxide (ITO)-coated glass substrate used as cathode and parallel platinum plate as the counter electrode. This platform is utilized to fabricate a DNA biosensor, by immobilizing a probe sequence specific to Escherichia coli. The bioelectrode shows a surface-controlled electrode reaction with the electron transfer coefficient (α) of 0.64 and charge transfer rate constant (ks) of 61.73 s-1. Under the optimal conditions, this biosensor shows a detection limit of 8.7 × 10-14 M and is found to retain about 81% of the initial activity after 9 cycles of use.Herein, we envisage the possibility of preparing stable cationic poly(lactic-co-glycolic acid) (PLGA) microspheres encapsulating the iron oxide nanoparticles (IONPs; 8-12 nm). The IONPs are incorporated into PLGA in organic phase followed by microsphere formation and chitosan coating in aqueous medium via nano-emulsion technique. The average size of the microspheres, as determined by dynamic light scattering are about 310 nm, while the zeta potential for the composite remains near 35 mV at pH 4.0. These microspheres are electrophoretically deposited onto indium tin oxide (ITO)-coated glass substrate used as cathode and parallel platinum plate as the counter electrode. This platform is utilized to fabricate a DNA biosensor, by immobilizing a probe sequence specific to Escherichia coli. The bioelectrode shows a surface-controlled electrode reaction with the

  18. Pulsed-current charging of lead/acid batteries — a possible means for overcoming premature capacity loss?

    NASA Astrophysics Data System (ADS)

    Lam, L. T.; Ozgun, H.; Lim, O. V.; Hamilton, J. A.; Vu, L. H.; Vella, D. G.; Rand, D. A. J.

    A pulsed-current technique is evaluated for the rapid charging of lead/acid cells that are prepared with either low-antimony or lead-calcium-tin grids. For comparative purposes, these cells are subjected to repetitive reserve-capacity cycling under either pulsed-current or conventional, invariant-current recharge. Although the latter charging is recommended by the manufacturers of the respective grids, it invokes premature capacity loss when combined with the high-rate discharge of the reserve-capacity test. Two significant benefits are found with the pulsed-current technique, namely, a reduction in recharging time by an order of magnitude (i.e., from ˜10 to ˜1 h), and an increase in cycle life by a factor of three to four. Temperature effects play only a minor role in prolonging battery endurance under pulsed-charging conditions. The technique also has the ability to recover the capacity of cycled cells. As expected, premature capacity loss occurs in both PbSb and PbCaSn cells cycled under invariant-current charging. The phenomenon is more acute in PbCa-based cells. The decline in capacity of PbSb cells is associated with a progressive change in the nature of the positive active material, i.e., from low crystallinity in the precursor material to a more defined crystallinity in the cycled mass. This behaviour reduces both the available surface area and the reactivity of the active material with the battery acid. By contrast, the capacity loss in PbCaSn cells is related to both a progressive increase in the crystallization of the active material during cycling (i.e., development of small crystals) and to the growth of a resistive 'PbO' layer immediately adjacent to the grid member. The latter phenomenon is the more dominant. Pulsed-current charging is found to be an effective means for delaying the crystallization process in the active material, as well as for minimizing the development of the 'PbO' layer during cycling. Thus, pulsed charging

  19. The effect of copper deficiency on fetal growth and liver anti-oxidant capacity in the Cohen diabetic rat model

    SciTech Connect

    Ergaz, Zivanit; Shoshani-Dror, Dana; Guillemin, Claire; Neeman-azulay, Meytal; Fudim, Liza; Weksler-Zangen, Sarah; Stodgell, Christopher J.; Miller, Richard K.; Ornoy, Asher

    2012-12-01

    High sucrose low copper diet induces fetal growth restriction in the three strains of the Cohen diabetic rats: an inbred copper deficient resistant (CDr), an inbred copper deficient sensitive (CDs that become diabetic on high sucrose low copper diet -HSD) and an outbred Wistar derived Sabra rats. Although those growth restricted fetuses also exhibit increased oxidative stress, antioxidants do not restore normal growth. In the present study, we evaluated the role of copper deficiency in the HSD induced fetal growth restriction by adding to the drinking water of the rats 1 ppm or 2 ppm of copper throughout their pregnancy. Fetal and placental growth in correlation with fetal liver copper content and anti-oxidant capacity was evaluated on day 21 of pregnancy. HSD compared to regular chow induced fetal growth restriction, which was most significant in the Cohen diabetic sensitive animals. The addition of 1 ppm and 2 ppm copper to the drinking water normalized fetal growth in a dose dependent manner and reduced the degree of hyperglycemia in the diabetes sensitive rats. The CDs fetuses responded to the HSD with lower catalase like activity, and less reduced superoxide dismutase levels compared to the Sabra strain, and had high malondialdehyde levels even when fed regular chow. Immunostaining was higher for nitrotyrosine among the CDr and higher for hypoxia factor 1 α among the CDs. We conclude that in our model of dietary-induced fetal growth restriction, copper deficiency plays a major etiologic role in the decrease of fetal growth and anti-oxidant capacity. -- Highlights: ► High sucrose low copper diet restricted fetal growth in the Cohen diabetic rat model ► Maternal copper blood levels directly correlated with fetal liver copper content ► Copper supplementation decreased embryonic resorption in the inbred strains ► Copper supplementation reduced hyperglycemia in the sucrose sensitive inbred strain ► Copper supplementation alleviated growth restriction and

  20. A novel system combining biocatalytic dephosphorylation of L-ascorbic acid 2-phosphate and electrochemical oxidation of resulting ascorbic acid.

    PubMed

    Kuwahara, Takashi; Homma, Toshimasa; Kondo, Mizuki; Shimomura, Masato

    2011-03-15

    An enzyme electrode was prepared with acid phosphatase (ACP) for development of a new electric power generation system using ascorbic acid 2-phosphate (AA2P) as a fuel. The properties of the electrode were investigated with respect to biocatalytic dephosphorylation of AA2P and electrochemical oxidation of resulting ascorbic acid (AA). The enzyme electrode was fabricated by immobilization of ACP through amide linkage onto a self-assembled monolayer of 3-mercaptopropionic acid on a gold electrode. AA2P was not oxidized on a bare gold electrode in the potential sweep range from -0.1 to +0.5 V vs. Ag/AgCl. However, the enzyme electrode gave an oxidation current in citric buffer solution of pH 5 containing 10 mM of AA2P. The oxidation current began to increase at +0.2V, and reached to 5.0 μA cm(-2) at +0.5 V. The potential +0.2 V corresponded to the onset of oxidation of ascorbic acid (AA). These results suggest that the oxidation current observed with the enzyme electrode is due to AA resulting from dephosphorylation of AA2P. The oxidation current increased with increasing concentration of AA2P and almost leveled off at around the concentration of 5mM. Thus the enzyme electrode brought about biocatalytic conversion of AA2P to AA, followed by electrochemical oxidation of the AA. The oxidation current is likely to be controlled by the biocatalytic reaction. PMID:21247749

  1. Syntheses of hydroxamic acid-containing bicyclic β-lactams via palladium-catalyzed oxidative amidation of alkenes.

    PubMed

    Jobbins, Maria O; Miller, Marvin J

    2014-02-21

    Palladium-catalyzed oxidative amidation has been used to synthesize hydroxamic acid-containing bicyclic β-lactam cores. Oxidative cleavage of the pendant alkene provides access to the carboxylic acid in one step. PMID:24483144

  2. The Use of Ascorbate as an Oxidation Inhibitor in Prebiotic Amino Acid Synthesis: A Cautionary Note

    NASA Astrophysics Data System (ADS)

    Kuwahara, Hideharu; Eto, Midori; Kawamoto, Yukinori; Kurihara, Hironari; Kaneko, Takeo; Obayashi, Yumiko; Kobayashi, Kensei

    2012-12-01

    It is generally thought that the terrestrial atmosphere at the time of the origin of life was CO2-rich and that organic compounds such as amino acids would not have been efficiently formed abiotically under such conditions. It has been pointed out, however, that the previously reported low yields of amino acids may have been partially due to oxidation by nitrite/nitrate during acid hydrolysis. Specifically, the yield of amino acids was found to have increased significantly (by a factor of several hundred) after acid hydrolysis with ascorbic acid as an oxidation inhibitor. However, it has not been shown that CO2 was the carbon source for the formation of the amino acids detected after acid hydrolysis with ascorbic acid. We therefore reinvestigated the prebiotic synthesis of amino acids in a CO2-rich atmosphere using an isotope labeling experiment. Herein, we report that ascorbic acid does not behave as an appropriate oxidation inhibitor, because it contributes amino acid contaminants as a consequence of its reactions with the nitrogen containing species and formic acid produced during the spark discharge experiment. Thus, amino acids are not efficiently formed from a CO2-rich atmosphere under the conditions studied.

  3. The effect of the thermal reduction temperature on the structure and sorption capacity of reduced graphene oxide materials

    NASA Astrophysics Data System (ADS)

    Dolbin, Alexandr V.; Khlistyuck, Maria V.; Esel'son, Valentin B.; Gavrilko, Viktor G.; Vinnikov, Nikolay A.; Basnukaeva, Razet M.; Maluenda, Irene; Maser, Wolfgang K.; Benito, Ana M.

    2016-01-01

    The influence of reduction temperatures on the structure and the sorption capacity of thermally reduced graphene (TRGO) has been investigated systematically. A set of TRGO materials were prepared by thermal treatment of parent graphene oxide (GO) at five temperatures (T = 200, 300, 500, 700, and 900 °C). Investigations of these materials by X-ray diffraction, Raman spectroscopy and X-ray photoemission spectroscopy methods have shown that both the structure and the residual oxygen functional groups on the TRGO surface can be controlled by varying the temperature of the thermal treatment. The data on the sorption and desorption of 4He, H2, N2, Ne and Kr gases in the temperature interval T = 2-290 K clearly demonstrate that the sorption capacity of TRGO is closely related to the structural changes induced by the treatment temperatures. It is important that the sorption capacities of TRGOs treated at 300 °C and at 900 °C significantly increase for all the gases used. The prominent increase in the sorption capacity at 300 °C is attributed to the structural disorder and liberation of the pores caused by the removal of intercalated water and labile oxygen functional groups (oFGs) favored at this temperature. At 900 °C the sorption capacity increases due to the generation of new defects on the TRGO surface, which provide additional access to the internal space between the folds and sheets of the TRGO structure. By tailoring the structural properties we emphasize the potential of TRGO as a highly efficient sorbent.

  4. Divergent role of nitric oxide in insulin-stimulated aortic vasorelaxation between low- and high-intrinsic aerobic capacity rats.

    PubMed

    Crissey, Jacqueline M; Padilla, Jaume; Vieira-Potter, Victoria J; Thorne, Pamela K; Koch, Lauren G; Britton, Steven L; Thyfault, John P; Laughlin, M Harold

    2015-07-01

    Low-intrinsic aerobic capacity is associated with increased risk for cardiovascular and metabolic diseases and is a strong predictor of early mortality. The effects of intrinsic aerobic capacity on the vascular response to insulin are largely unknown. We tested the hypothesis that rats selectively bred for a low capacity to run (LCR) exhibit vascular dysfunction and impaired vascular reactivity to insulin compared to high capacity running (HCR) rats. Mature female LCR (n = 21) and HCR (n = 17) rats were maintained under sedentary conditions, and in vitro thoracic aortic vascular function was assessed. LCR exhibited greater body mass (13%), body fat (35%), and subcutaneous, perigonadal, and retroperitoneal adipose tissue mass, than HCR. During an intraperitoneal glucose tolerance test, glucose area under the curve (AUC) was not different but insulin AUC was 2-fold greater in LCR than HCR. Acetylcholine and insulin-stimulated aortic vasorelaxation was significantly greater in LCR (65.2 ± 3.8%, and 32.7 ± 4.1%) than HCR (55.0 ± 3.3%, and 16.7 ± 2.8%). Inhibition of nitric oxide synthase (NOS) with L-NAME entirely abolished insulin-mediated vasorelaxation in the aorta of LCR, with no effect in HCR. LCR rats exhibited greater expression of Insulin Receptor protein, lower Endothelin Receptor-A protein, a down-regulation of transcripts for markers of immune cell infiltration (CD11C, CD4, and F4/80) and up-regulation of pro-atherogenic inflammatory genes (VCAM-1 and MCP-1) in the aorta wall. Contrary to our hypothesis, low-aerobic capacity was associated with enhanced aortic endothelial function and NO-mediated reactivity to insulin, despite increased adiposity and evidence of whole body insulin resistance. PMID:26197933

  5. Generation of organic acids and monosaccharides by hydrolytic and oxidative transformation of food processing residues.

    PubMed

    Fischer, Klaus; Bipp, Hans-Peter

    2005-05-01

    Carbohydrate-rich biomass residues, i.e. sugar beet molasses, whey powder, wine yeast, potato peel sludge, spent hops, malt dust and apple marc, were tested as starting materials for the generation of marketable chemicals, e.g. aliphatic acids, sugar acids and mono-/disaccharides. Residues were oxidized or hydrolyzed under acidic or alkaline conditions applying conventional laboratory digestion methods and microwave assisted techniques. Yields and compositions of the oxidation products differed according to the oxidizing agent used. Main products of oxidation by 30% HNO(3) were acetic, glucaric, oxalic and glycolic acids. Applying H(2)O(2)/CuO in alkaline solution, the organic acid yields were remarkably lower with formic, acetic and threonic acids as main products. Gluconic acid was formed instead of glucaric acid throughout. Reaction of a 10% H(2)O(2) solution with sugar beet molasses generated formic and lactic acids mainly. Na(2)S(2)O(8) solutions were very inefficient at oxidizing the residues. Glucose, arabinose and galactose were formed during acidic hydrolysis of malt dust and apple marc. The glucose content reached 0.35 g per gram of residue. Important advantages of the microwave application were lower reaction times and reduced reagent demands. PMID:15607197

  6. Stannous sulfate as an electrolyte additive for lead acid battery made from a novel ultrafine leady oxide

    NASA Astrophysics Data System (ADS)

    Wang, Qin; Liu, Jianwen; Yang, Danni; Yuan, Xiqing; Li, Lei; Zhu, Xinfeng; Zhang, Wei; Hu, Yucheng; Sun, Xiaojuan; Liang, Sha; Hu, Jingping; Kumar, R. Vasant; Yang, Jiakuan

    2015-07-01

    The effects of SnSO4 as an electrolyte additive on the microstructure of positive plate and electrochemical performance of lead acid battery made from a novel leady oxide are investigated. The novel leady oxide is synthesized through leaching of spent lead paste in citric acid solution. The novel leady oxides are used to prepare working electrode (WE) subjected to electrochemical cyclic voltammetry (CV) tests. Moreover, the novel leady oxides are used as active materials of positive plate assembled as a testing battery of 1.85 A h capacity. In CV tests, SEM/EDX results show that the major crystalline phase of the paste in WE after CV cycles is PbSO4. The larger column-shaped PbSO4 crystals easily generate in the paste of WE without an electrolyte additive of SnSO4. However, PbSO4 crystals significantly become smaller with the addition of SnSO4 in the electrolyte. In batteries testing, SEM results show that an electrolyte additive of SnSO4 could effectively decrease PbO2 particle size in the positive active materials of the teardown battery at the end of charging procedure. It is indicated that an electrolyte additive of SnSO4 could have a positive influence on restraining larger particles of irreversible sulfation in charge/discharge cycles of battery testing.

  7. Modulation of FadR binding capacity for acyl-CoA fatty acids through structure-guided mutagenesis.

    PubMed

    Bacik, John-Paul; Yeager, Chris M; Twary, Scott N; Martí-Arbona, Ricardo

    2015-10-01

    FadR is a versatile global regulator in Escherichia coli that controls fatty acid metabolism and thereby modulates the ability of this bacterium to grow using fatty acids or acetate as the sole carbon source. FadR regulates fatty acid metabolism in response to intra-cellular concentrations of acyl-CoA lipids. The ability of FadR to bind acyl-CoA fatty acids is thus of significant interest for the engineering of biosynthetic pathways for the production of lipid-based biofuels and commodity chemicals. Based on the available crystal structure of E. coli bound to myristoyl-CoA, we predicted amino acid positions within the effector binding pocket that would alter the ability of FadR to bind acyl-CoA fatty acids without affecting DNA binding. We utilized fluorescence polarization to characterize the in vitro binding properties of wild type and mutant FadR. We found that a Leu102Ala mutant enhanced binding of the effector, likely by increasing the size of the binding pocket for the acyl moiety of the molecule. Conversely, the elimination of the guanidine side chain (Arg213Ala and Arg213Met mutants) of the CoA moiety binding site severely diminished the ability of FadR to bind the acyl-CoA effector. These results demonstrate the ability to fine tune FadR binding capacity. The validation of an efficient method to fully characterize all the binding events involved in the specific activity (effector and DNA operator binding) of FadR has allowed us to increase our understanding of the role of specific amino acids in the binding and recognition of acyl-CoA fatty acids and will greatly facilitate efforts aimed at engineering tunable FadR regulators for synthetic biology. PMID:26385696

  8. Modulation of FadR Binding Capacity for Acyl-CoA Fatty Acids Through Structure-Guided Mutagenesis

    DOE PAGESBeta

    Bacik, John-Paul; Yeager, Chris M.; Twary, Scott N.; Martí-Arbona, Ricardo

    2015-09-18

    FadR is a versatile global regulator in Escherichia coli that controls fatty acid metabolism and thereby modulates the ability of this bacterium to grow using fatty acids or acetate as the sole carbon source. FadR regulates fatty acid metabolism in response to intra-cellular concentrations of acyl-CoA lipids. The ability of FadR to bind acyl-CoA fatty acids is hence of significant interest for the engineering of biosynthetic pathways for the production of lipid-based biofuels and commodity chemicals. Based on the available crystal structure of E. coli bound to myristoyl- CoA, we predicted amino acid positions within the effector binding pocket thatmore » would alter the ability of FadR to bind acyl-CoA fatty acids without affecting DNA binding. We utilized fluorescence polarization to characterize the in-vitro binding properties of wild type and mutant FadR. We found that a Leu102Ala mutant enhanced binding of the effector, likely by increasing the size of the binding pocket for the acyl moiety of the molecule. Conversely, the elimination of the guanidine side chain (Arg213Ala and Arg213Met mutants) of the CoA moiety binding site severely diminished the ability of FadR to bind the acyl-CoA effector. These results demonstrate the ability to fine tune FadR binding capacity. The validation of an efficient method to fully characterize all the binding events involved in the specific activity (effector and DNA operator binding) of FadR has allowed us to increase our understanding of the role of specific amino acids in the binding and recognition of acyl-CoA fatty acids and will greatly facilitate efforts aimed at engineering tunable FadR regulators for synthetic biology.« less

  9. Modulation of FadR Binding Capacity for Acyl-CoA Fatty Acids Through Structure-Guided Mutagenesis

    SciTech Connect

    Bacik, John-Paul; Yeager, Chris M.; Twary, Scott N.; Martí-Arbona, Ricardo

    2015-09-18

    FadR is a versatile global regulator in Escherichia coli that controls fatty acid metabolism and thereby modulates the ability of this bacterium to grow using fatty acids or acetate as the sole carbon source. FadR regulates fatty acid metabolism in response to intra-cellular concentrations of acyl-CoA lipids. The ability of FadR to bind acyl-CoA fatty acids is hence of significant interest for the engineering of biosynthetic pathways for the production of lipid-based biofuels and commodity chemicals. Based on the available crystal structure of E. coli bound to myristoyl- CoA, we predicted amino acid positions within the effector binding pocket that would alter the ability of FadR to bind acyl-CoA fatty acids without affecting DNA binding. We utilized fluorescence polarization to characterize the in-vitro binding properties of wild type and mutant FadR. We found that a Leu102Ala mutant enhanced binding of the effector, likely by increasing the size of the binding pocket for the acyl moiety of the molecule. Conversely, the elimination of the guanidine side chain (Arg213Ala and Arg213Met mutants) of the CoA moiety binding site severely diminished the ability of FadR to bind the acyl-CoA effector. These results demonstrate the ability to fine tune FadR binding capacity. The validation of an efficient method to fully characterize all the binding events involved in the specific activity (effector and DNA operator binding) of FadR has allowed us to increase our understanding of the role of specific amino acids in the binding and recognition of acyl-CoA fatty acids and will greatly facilitate efforts aimed at engineering tunable FadR regulators for synthetic biology.

  10. Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

    SciTech Connect

    Frei, B. )

    1991-12-01

    The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

  11. Impact of Dry Solids and Bile Acid Concentrations on Bile Acid Binding Capacity of Extruded Oat Cereals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extruded breakfast cereals (EBC), processed from two oat lines, N979-5-2-4 (N979) and ‘Jim’, with beta-glucan concentrations of 8.7 and 4.9%, respectively, were used to determine the impact of dry solids (DS) and bile acid (BA) concentrations on in vitro BA binding efficiency. A full fractional fact...

  12. Use of Sodium Butyrate as an Alternative to Dietary Fiber: Effects on the Embryonic Development and Anti-Oxidative Capacity of Rats

    PubMed Central

    Lin, Yan; Fang, Zheng-feng; Che, Lian-qiang; Xu, Sheng-yu; Wu, De; Wu, Cai-mei; Wu, Xiu-qun

    2014-01-01

    In this study, we evaluated the effect of replacing dietary fiber with sodium butyrate on reproductive performance and antioxidant defense in a high fat diet during pregnancy by using a rat model. Eighty virgin female Sprague Dawley rats were fed one of four diets—(1) control diet (C group), (2) high fat + high fiber diet (HF group), (3) high-fat +5% sodium butyrate diet (SB group), and (4) HF diet + α-cyano-4-hydroxy cinnamic acid (CHC group)—intraperitoneally on days 8, 10, 12, 14, and 16 of gestation. SB and dietary fiber had similar effects on improving fetal number and reducing the abortion rate; however, the anti-oxidant capacity of maternal serum, placenta, and fetus was superior in the HF group than in the SB group. In comparison, CHC injection decreased reproductive performance and antioxidant defense. Both dietary fiber (DF) and SB supplementation had a major but different effect on the expression of anti-oxidant related genes and nutrient transporters genes. In summary, our data indicate that SB and DF showed similar effect on reproductive performance, but SB cannot completely replace the DF towards with respect to redox regulation in high-fat diet; and SB might influence offspring metabolism and health differently to DF. PMID:24852604

  13. [Changes in antioxidant capacity of the guinea pig exposed to noise and the protective effect of alpha-lipoic acid against acoustic trauma].

    PubMed

    Diao, Ming-Fang; Liu, Hai-Ying; Zhang, Yan-Min; Gao, Wen-Yuan

    2003-12-25

    The study was aimed at exploring the effect of noise on total antioxidant capacity (TAC) in serum, nitric oxide (NO) level in the cochlea and the protective action of alpha-lipoic acid against noise-induced hearing loss (NIHL). Sixty guinea pigs (350-400 g) were divided randomly into three groups (control group, noise+saline group and noise+alpha-lipoic acid group). Serum and cochlear tissue were treated immediately after noise exposure (4-kHz octave band, 115 dB SPL 5 h) to determine the level of TAC and NO, respectively. Auditory brainstem responses (ABRs) were measured before and immediately after exposure. The threshold of hearing in the control group was relatively stable, while the hearing threshold in the noise+saline group was significantly higher than those in the noise+alpha-lipoic acid group (P<0.05). TAC level of the noise+saline group was significantly lower than that of the control group P<0.05 . TAC level of the noise+alpha-lipoic acid group was significantly higher than that of the noise+saline group P<0.05 , while there was no significant difference in the levels between the noise+alpha-lipoic acid group and the control group (P>0.05). The NO level of the cochlear tissue in the noise+saline group was significantly higher than that of the control group (P<0.05). Cochlear NO level in the noise+alpha-lipoic acid group was significantly lower than that of the noise+saline group (P<0.05), while there was no significant difference in cochlear NO levels between the noise+alpha-lipoic acid group and the control group (P>0.05). The results obtained indicate that noise exposure causes a decrease in serum TAC and an increase in NO in cochlea. alpha-Lipoid acid exerts a protective effect against hearing loss in acoustic trauma through its antioxidant effects. PMID:14695484

  14. Impact of acid and oxidative modifications, single or dual, of sorghum starch on biodegradable films.

    PubMed

    Biduski, Bárbara; Silva, Francine Tavares da; Silva, Wyller Max da; Halal, Shanise Lisie de Mello El; Pinto, Vania Zanella; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2017-01-01

    The objective of this study was to evaluate the effects of acid and oxidation modifications on sorghum starch, as well as the effect of dual modification of starch on the physical, morphological, mechanical, and barrier properties of biodegradable films. The acid modification was performed with 3% lactic acid and the oxidation was performed with 1.5% active chlorine. For dual modification, the acid modification was performed first, followed by oxidation under the same conditions as above. Both films of the oxidized starches, single and dual, had increased stiffness, providing a higher tensile strength and lower elongation when compared to films based on native and single acid modified starches. However, the dual modification increased the water vapor permeability of the films without changing their solubility. The increase in sorghum starch concentration in the filmogenic solution increased the thickness, water vapor permeability, and elongation of the films. PMID:27507447

  15. Regulation of skeletal muscle oxidative capacity and muscle mass by SIRT3

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously reported that the expression of mitochondrial deacetylase SIRT3 is high in the slow oxidative muscle and that the expression of muscle SIRT3 level is increased by dietary restriction or exercise training. To explore the function of SIRT3 in skeletal muscle, we report here the esta...

  16. Metal ion adsorption to complexes of humic acid and metal oxides: Deviations from the additivity rule

    SciTech Connect

    Vermeer, A.W.P.; McCulloch, J.K.; Van Riemsdijk, W.H.; Koopal, L.K.

    1999-11-01

    The adsorption of cadmium ions to a mixture of Aldrich humic acid and hematite is investigated. The actual adsorption to the humic acid-hematite complex is compared with the sum of the cadmium ion adsorptivities to each of the isolated components. It is shown that the sum of the cadmium ion adsorptivities is not equal to the adsorption to the complex. In general, the adsorption of a specific metal ion to the complex can be understood and qualitatively predicted using the adsorptivities to each of the pure components and taking into account the effect of the pH on the interaction between humic acid and iron oxide on the metal ion adsorption. Due to the interaction between the negatively charged humic acid and the positively charged iron oxide, the adsorption of metal ions on the mineral oxide in the complex will increase as compared to that on the isolated oxide, whereas the adsorption to the humic acid will decrease as compared to that on the isolated humic acid. As a result, the overall adsorption of a specific metal ion to the complex will be smaller than predicted by the additivity rule when this metal ion has a more pronounced affinity for the humic acid than for the mineral oxide, whereas it will be larger than predicted by the additivity rule when the metal ion has a higher affinity for the oxide than for the humic acid.

  17. Mitochondrial coupling and capacity of oxidative phosphorylation in skeletal muscle of Inuit and Caucasians in the arctic winter.

    PubMed

    Gnaiger, E; Boushel, R; Søndergaard, H; Munch-Andersen, T; Damsgaard, R; Hagen, C; Díez-Sánchez, C; Ara, I; Wright-Paradis, C; Schrauwen, P; Hesselink, M; Calbet, J A L; Christiansen, M; Helge, J W; Saltin, B

    2015-12-01

    During evolution, mitochondrial DNA haplogroups of arctic populations may have been selected for lower coupling of mitochondrial respiration to ATP production in favor of higher heat production. We show that mitochondrial coupling in skeletal muscle of traditional and westernized Inuit habituating northern Greenland is identical to Danes of western Europe haplogroups. Biochemical coupling efficiency was preserved across variations in diet, muscle fiber type, and uncoupling protein-3 content. Mitochondrial phenotype displayed plasticity in relation to lifestyle and environment. Untrained Inuit and Danes had identical capacities to oxidize fat substrate in arm muscle, which increased in Danes during the 42 days of acclimation to exercise, approaching the higher level of the Inuit hunters. A common pattern emerges of mitochondrial acclimatization and evolutionary adaptation in humans at high latitude and high altitude where economy of locomotion may be optimized by preservation of biochemical coupling efficiency at modest mitochondrial density, when submaximum performance is uncoupled from VO2max and maximum capacities of oxidative phosphorylation. PMID:26589126

  18. Total Antioxidant Capacity and Total Oxidant Status in Saliva of Periodontitis Patients in Relation to Bacterial Load

    PubMed Central

    Zhang, Taowen; Andrukhov, Oleh; Haririan, Hady; Müller-Kern, Michael; Liu, Shutai; Liu, Zhonghao; Rausch-Fan, Xiaohui

    2016-01-01

    The detection of salivary biomarkers has a potential application in early diagnosis and monitoring of periodontal inflammation. However, searching sensitive salivary biomarkers for periodontitis is still ongoing. Oxidative stress is supposed to play an important role in periodontitis progression and tissue destruction. In this cross-sectional study, we investigated total antioxidant capacity (TAC) and total oxidant status (TOS) in saliva of periodontitis patients compared to healthy controls and their relationship with periodontopathic bacteria and periodontal disease severity. Unstimulated saliva was collected from 45 patients with generalized severe periodontitis and 37 healthy individuals and the TAC/TOS were measured. In addition, salivary levels of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum in saliva were measured. Salivary TAC was lower in periodontitis patients compared to healthy controls. Moreover, a significant negative correlation of salivary TAC with clinical attachment loss was observed in periodontitis patients. No significant difference in the salivary TOS was observed between periodontitis patients and healthy controls. Bacterial load was enhanced in periodontitis patients and exhibited correlation with periodontal disease severity but not with salivary TAC/TOS. Our data suggest that changes in antioxidant capacity in periodontitis patients are not associated with increased bacterial load and are probably due to a dysregulated immune response. PMID:26779448

  19. Oxidation-Resistant Coating For Bipolar Lead/Acid Battery

    NASA Technical Reports Server (NTRS)

    Bolstad, James J.

    1993-01-01

    Cathode side of bipolar substrate coated with nonoxidizable conductive layer. Coating prepared as water slurry of aqueous dispersion of polyethylene copolymer plus such conductive fillers as tin oxide, titanium, tantalum, or tungsten oxide. Applied easily to substrate of polyethylene carbon plastic. As slurry dries, conductive, oxidation-resistant coating forms on positive side of substrate.

  20. Peroxisomal and mitochondrial fatty acid oxidation in human hepatoma cells (HEP-G2)

    SciTech Connect

    Watkins, P.A.; Blake, D.C. Jr.; Pedersen, J.I.

    1987-05-01

    Hep-G2 cells oxidize (1-/sup 14/C)palmitic acid (C16) and (1-/sup 14/C) lignoceric acid (C24) via beta-oxidation to /sup 14/CO/sub 2/ and water-soluble (WS) products. After perchloric acid precipitation and chloroform-methanol extraction, the WS fraction contained labelled oxidation products as well as fatty acyl CoA's, thus, measurement of WS radioactivity is an overestimate of Hep-G2 beta-oxidation. Alkaline hydrolysis of fatty acyl CoA's prior to measurement of WS radioactivity permits more accurate assessment of beta-oxidation. Using this method, the optimal pH for oxidation of each fatty acid to WS products by Hep-G2 cells was 9.0, while /sup 14/CO/sub 2/ production was maximal at pH 7.0. To determine the subcellular location of beta-oxidation, mitochondria (M) were partially separated from peroxisomes (P) on linear Nycodenz gradients. In Hep-G2 cells, oxidation of both C16 and C24 was observed mainly in fractions enriched in succinate dehydrogenase, an M marker enzyme. In contrast, both P and M of rat liver oxidized these fatty acids. However, when Hep-G2 cells were fractionated on discontinuous sucrose gradients, C16 and C24 were oxidized by both P and M fractions. They conclude that beta-oxidation of both long (C16) and very long (C24) chain fatty acids occurs in P as well as in M of Hep-G2 cells, and the present method reflects a more accurate and sensitive measurement of oxidation rates.

  1. Kinetics and Products of Heterogeneous Oxidation of Oleic acid, Linoleic acid and Linolenic acid in Aerosol Particles by Hydroxyl radicals

    NASA Astrophysics Data System (ADS)

    Nah, T.; Leone, S. R.; Wilson, K. R.

    2010-12-01

    A significant mass fraction of atmospheric aerosols is composed of a variety of oxidized organic compounds with varying functional groups that may affect the rate at which they chemically age. Here we study the heterogeneous reaction of OH radicals with different sub-micron, alkenoic acid particles: Oleic acid (OA), Linoleic acid (LA), and Linolenic acid (LNA), in the presence of H2O2 and O2. This research explores how OH addition reactions initiate chain reactions that rapidly transform the chemical composition of an organic particle. Particles are chemically aged in a photochemical flow tube reactor where they are exposed to OH radicals (~ 1011 molecule cm-3 s) that are produced by the photolysis of H2O2 at 254 nm. The aerosols are then sized and their composition analyzed via Atmospheric Pressure Chemical Ionization (APCI). Detailed kinetic measurements show that the reactive uptake coefficient is larger than 1, indicating the presence of secondary chemistry occurring in the condensed phase. Reactive uptake coefficient is found to scale linearly with the number of double bonds present in the molecule. In addition, the reactive uptake coefficient is found to depend sensitively upon the concentrations of O2 in the photochemical flow tube reactor, indicating that O2 plays a role in secondary chemistry. In the absence of O2 the reactive uptake coefficient increases to ~ 8, 5 and 3 for LNA, LA, and OA, respectively. The reactive uptake coefficient approaches values of 6, 4 and 2 for LNA, LA, and OA respectively when 18% of the total nitrogen flow is replaced with O2. Mechanistic pathways and products will also be presented herein.

  2. Caffeic Acid Phenethyl Ester as a Protective Agent against Nephrotoxicity and/or Oxidative Kidney Damage: A Detailed Systematic Review

    PubMed Central

    Akyol, Sumeyya; Ugurcu, Veli; Altuntas, Aynur; Hasgul, Rukiye; Cakmak, Ozlem

    2014-01-01

    Caffeic acid phenethyl ester (CAPE), an active component of propolis, has been attracting the attention of different medical and pharmaceutical disciplines in recent years because of its antioxidant, anti-inflammatory, antiproliferative, cytotoxic, antiviral, antifungal, and antineoplastic properties. One of the most studied organs for the effects of CAPE is the kidney, particularly in the capacity of this ester to decrease the nephrotoxicity induced by several drugs and the oxidative injury after ischemia/reperfusion (I/R). In this review, we summarized and critically evaluated the current knowledge regarding the protective effect of CAPE in nephrotoxicity induced by several special medicines such as cisplatin, doxorubicin, cyclosporine, gentamycin, methotrexate, and other causes leading to oxidative renal injury, namely, I/R models and senility. PMID:25003138

  3. The rationale for preventing cancer cachexia: targeting excessive fatty acid oxidation.

    PubMed

    Qian, Chao-Nan

    2016-01-01

    Cachexia commonly occurs at the terminal stage of cancer and has largely unclear molecular mechanisms. A recent study published in Nature Medicine, entitled "Excessive fatty acid oxidation induces muscle atrophy in cancer cachexia," reveals that cachectic cancer cells can secrete multiple cytokines that induce excessive fatty acid oxidation, which is responsible for muscle loss in cancer cachexia. Inhibition of fatty acid oxidation using etomoxir can increase muscle mass and body weight in cancer cachexia animal models. The usage of stable cachexia animal models is also discussed in this research highlight. PMID:27443316

  4. Evaluation of Humic Acid and Tannic Acid Fouling in Graphene Oxide-Coated Ultrafiltration Membranes.

    PubMed

    Chu, Kyoung Hoon; Huang, Yi; Yu, Miao; Her, Namguk; Flora, Joseph R V; Park, Chang Min; Kim, Suhan; Cho, Jaeweon; Yoon, Yeomin

    2016-08-31

    Three commercially available ultrafiltration (UF) membranes (poly(ether sulfone), PES) that have nominal molecular weight cut-offs (5, 10, and 30 kDa) were coated with graphene oxide (GO) nanosheets. Field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, confocal laser scanning microscopy, water contact angle measurements, and X-ray photoelectron spectroscopy were employed to determine the changed physicochemical properties of the membranes after GO coating. The water permeability and single-solute rejection of GO-coated (GOC) membranes for humic acid (HA) molecules were significantly higher by approximately 15% and 55%, respectively, compared to those of pristine UF membranes. However, the GOc membranes for single-solute tannic acid (TA) rejection showed similar trends of higher flux decline versus pristine PES membranes, because the relatively smaller TA molecules were readily adsorbed onto the membrane pores. When the mixed-solute of HA and TA rejection tests were performed, in particular, the adsorbed small TA molecules resulted in irreversible membrane fouling due to cake formation and membrane pore blocking on the membrane surface for the HA molecules. Although both membranes showed significantly higher flux declines for small molecules rejection, the GOc membranes showed better performance than the pristine UF membranes in terms of the rejection of various mixed-solute molecules, due to higher membrane recovery and antifouling capabilities. PMID:27517308

  5. Recent new additives for electric vehicle lead-acid batteries for extending the cycle life and capacity

    SciTech Connect

    Kozawa, A.; Sato, A.; Fujita, K.; Brodd, D.

    1997-12-01

    An electrochemically prepared colloidal graphite was found to be an excellent additive for lead-acid batteries. The new additive extends the capacity and cycle life of new and old batteries and can regenerate old, almost dead, batteries. The colloidal graphite is stable in aqueous solution and the extremely fine particles are adsorbed mainly on the positive electrode. This additive has been given the name, {alpha}-Pholon. The amount required is very small: only 6% to 10% of volume of the {alpha}-Pholon solution (about 2% colloidal graphite in water solution). The beneficial effect of the new additive was demonstrated with motorcycle batteries and forklift batteries.

  6. Oxidation of L-ascorbic acid to dehydroascorbic acid on the surface of the red blood cell

    SciTech Connect

    Wagner, E.; Jennings, M.; Bennett, K.

    1986-05-01

    L-ascorbic acid-1-/sup 14/C when incubated with human blood did not bind irreversibly to any of the protein components of plasma but did migrate irreversibly into erythrocytes. Isolation and characterization via IR of the moiety trapped within the cell established its identity as apparently, unchanged L-ascorbic acid. When dehydroascorbic acid-1-/sup 14/C was incubated with human blood, the results were identical including the identity of the entrapped moiety, L-ascorbic acid. It was found that L-ascorbic acid was enzymatically oxidized on the surface of the red blood cell to dehydroascorbic acid which diffused through the lipid soluble portion of the cell membrane and was enzymatically reduced back to ascorbic acid within the cell.

  7. Effects of dietary n-3 highly unsaturated fatty acids (HUFAs) on growth, fatty acid profiles, antioxidant capacity and immunity of sea cucumber Apostichopus japonicus (Selenka).

    PubMed

    Yu, Haibo; Gao, Qinfeng; Dong, Shuanglin; Zhou, Jishu; Ye, Zhi; Lan, Ying

    2016-07-01

    The present study was conducted to understand the effects of dietary n-3 highly unsaturated fatty acids (HUFAs) on growth, fatty acid profiles, antioxidant capacity and the immunity of sea cucumber Apostichopus japonicus (Selenka). Five experimental diets were prepared, containing graded levels of n-3 HUFAs (0.46%, 0.85%, 1.25%, 1.61% and 1.95%, respectively), and the 0.46% group was used as control group. The specific growth rates, fatty acid profiles, activities and gene expression of antioxidative enzymes and lysozyme of the sea cucumbers that were fed with the 5 experimental diets were determined. The results showed that the specific growth rate of sea cucumbers in all the treatment groups significantly increased compared to the control group (P < 0.05), indicating the positive effects of n-3 HUFAs on the growth of sea cucumbers. The contents of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) in the body wall of the sea cucumbers gradually increased with the increasing levels of n-3 HUFAs in the diets. The suitable supplement of n-3 HUFAs in diets improved the activities of superoxide dismutase (SOD) and catalase (CAT) of sea cucumbers by up-regulating the expression of SOD and CAT mRNA in sea cucumbers. However, excess n-3 HUFAs in diets caused lipid peroxidation, inhibited the expression of lysozyme (LSZ) mRNA and decreased the activities of LSZ in sea cucumbers. In summary, the suitable supplement levels of n-3 HUFAs in diets of sea cucumbers A. japonicus were estimated between 0.85% and 1.25% considering the growth performance, cost and the indicators of antioxidant capacity and immunity. PMID:27079426

  8. Very-long-chain fatty acids restrict regeneration capacity by confining pericycle competence for callus formation in Arabidopsis.

    PubMed

    Shang, Baoshuan; Xu, Chongyi; Zhang, Xixi; Cao, Huifen; Xin, Wei; Hu, Yuxin

    2016-05-01

    The already differentiated organs in plants have a remarkable capacity to regenerate new individuals under culture conditions. Plant in vitro regeneration practically starts with the induction of a pluripotent cell mass, the callus, from detached organs on auxin-rich callus-inducing medium (CIM), which is generally required for subsequent regeneration of new bodies. Recent studies show that CIM-induced callus formation occurs from the pericycle or pericycle-like cells through a root developmental pathway, whereas the signals involved in governing callus-forming capacity of pericycle cells remain unknown. Here we report that very-long-chain fatty acids (VLCFAs) play a critical role in confining the pericycle competence for callus formation and thus the regeneration capacity of Arabidopsis By genetic screening, we identified the callus formation-related 1 (cfr1) mutant, which bypasses the inhibition of callus-forming capacity in roots by solitary-root (slr/iaa14). We show that CFR1 encodes 3-ketoacyl-CoA synthase 1 (KCS1), which catalyzes a rate-limiting step of VLCFA biosynthesis. Our biochemical and genetic analyses demonstrate that VLCFAs restrict the pericycle competence for callus formation, at least in part, by regulating the transcription of Aberrant Lateral Root Formation 4 (ALF4). Moreover, we provide evidence that VLCFAs act as cell layer signals to mediate the pericycle competence for callus formation. Taken together, our results identify VLCFAs or their derivatives as the confining signals for mediating the pericycle competence for callus formation and thus the regeneration capacity of plant organs. PMID:27092001

  9. Asphaltene adsorption onto acidic/basic metal oxide nanoparticles toward in situ upgrading of reservoir oils by nanotechnology.

    PubMed

    Hosseinpour, Negahdar; Khodadadi, Abbas Ali; Bahramian, Alireza; Mortazavi, Yadollah

    2013-11-19

    The effects of surface acidity and basicity of metal oxide nanoparticles on the thermodynamics of asphaltene adsorption were studied. Three different categories of metal oxides/salts with acidic (WO3 and NiO), amphoteric (Fe2O3 and ZrO2), and basic (MgO and CaCO3) surfaces were synthesized, and their textural, structural, and acid-base properties were characterized. Asphaltenes were extracted from a dead oil sample and characterized by X-ray powder diffraction and Fourier transform infrared spectroscopy. The acid and base numbers of the asphaltenes were measured. The nanoparticles were added to the asphaltene-toluene solutions, and the amount of adsorbed asphaltene was obtained through centrifugation followed by UV-vis spectroscopy of the supernatant liquid and temperature-programmed oxidation analysis of the precipitated solid. The concentrations of organic acid and base groups in the asphaltenes are 2.75 and 12.34 mg of KOH/g, respectively, indicating that the asphaltenes are more basic in nature. Isotherms of the asphaltene adsorption onto the six metal oxides/salts fit the Langmuir model closely. The asphaltene adsorption capacity of the nanoparticles is 1.23-3.67 mg/m(2) and decreases in the order of NiO > Fe2O3 > WO3 > MgO > CaCO3 > ZrO2, concomitant with the synergetic effects of acidity and the net charge of the surfaces. High-resolution transmission electron microscopy illustrates that the asphaltenes are spread out over the surfaces with no short-range/long-range order. The adsorption of the asphaltenes onto the six samples is exothermic and spontaneous with the Gibbs energy change of -27.80 to -28.79 kJ/mol at 25 °C. The absolute value of the enthalpy change of the adsorption is calculated to be within the range of 5-20 kJ/mol. Acid-base interaction and electrostatic attraction seem to be the dominant forces contributing to the adsorption of the asphaltenes onto the metal oxide/salt surfaces. PMID:24131407

  10. Activated Persulfate Oxidation of Perfluorooctanoic Acid (PFOA) in Groundwater under Acidic Conditions.

    PubMed

    Yin, Penghua; Hu, Zhihao; Song, Xin; Liu, Jianguo; Lin, Na

    2016-01-01

    Perfluorooctanoic acid (PFOA) is an emerging contaminant of concern due to its toxicity for human health and ecosystems. However, successful degradation of PFOA in aqueous solutions with a cost-effective method remains a challenge, especially for groundwater. In this study, the degradation of PFOA using activated persulfate under mild conditions was investigated. The impact of different factors on persulfate activity, including pH, temperature (25 °C-50 °C), persulfate dosage and reaction time, was evaluated under different experimental conditions. Contrary to the traditional alkaline-activated persulfate oxidation, it was found that PFOA can be effectively degraded using activated persulfate under acidic conditions, with the degradation kinetics following the pseudo-first-order decay model. Higher temperature, higher persulfate dosage and increased reaction time generally result in higher PFOA degradation efficiency. Experimental results show that a PFOA degradation efficiency of 89.9% can be achieved by activated persulfate at pH of 2.0, with the reaction temperature of 50 °C, molar ratio of PFOA to persulfate as 1:100, and a reaction time of 100 h. The corresponding defluorination ratio under these conditions was 23.9%, indicating that not all PFOA decomposed via fluorine removal. The electron paramagnetic resonance spectrometer analysis results indicate that both SO₄(-)• and •OH contribute to the decomposition of PFOA. It is proposed that PFOA degradation occurs via a decarboxylation reaction triggered by SO₄(-)•, followed by a HF elimination process aided by •OH, which produces one-CF₂-unit-shortened perfluoroalkyl carboxylic acids (PFCAs, Cn-1F2n-1COOH). The decarboxylation and HF elimination processes would repeat and eventually lead to the complete mineralization all PFCAs. PMID:27322298

  11. Activated Persulfate Oxidation of Perfluorooctanoic Acid (PFOA) in Groundwater under Acidic Conditions

    PubMed Central

    Yin, Penghua; Hu, Zhihao; Song, Xin; Liu, Jianguo; Lin, Na

    2016-01-01

    Perfluorooctanoic acid (PFOA) is an emerging contaminant of concern due to its toxicity for human health and ecosystems. However, successful degradation of PFOA in aqueous solutions with a cost-effective method remains a challenge, especially for groundwater. In this study, the degradation of PFOA using activated persulfate under mild conditions was investigated. The impact of different factors on persulfate activity, including pH, temperature (25 °C–50 °C), persulfate dosage and reaction time, was evaluated under different experimental conditions. Contrary to the traditional alkaline-activated persulfate oxidation, it was found that PFOA can be effectively degraded using activated persulfate under acidic conditions, with the degradation kinetics following the pseudo-first-order decay model. Higher temperature, higher persulfate dosage and increased reaction time generally result in higher PFOA degradation efficiency. Experimental results show that a PFOA degradation efficiency of 89.9% can be achieved by activated persulfate at pH of 2.0, with the reaction temperature of 50 °C, molar ratio of PFOA to persulfate as 1:100, and a reaction time of 100 h. The corresponding defluorination ratio under these conditions was 23.9%, indicating that not all PFOA decomposed via fluorine removal. The electron paramagnetic resonance spectrometer analysis results indicate that both SO4−• and •OH contribute to the decomposition of PFOA. It is proposed that PFOA degradation occurs via a decarboxylation reaction triggered by SO4−•, followed by a HF elimination process aided by •OH, which produces one-CF2-unit-shortened perfluoroalkyl carboxylic acids (PFCAs, Cn−1F2n−1COOH). The decarboxylation and HF elimination processes would repeat and eventually lead to the complete mineralization all PFCAs. PMID:27322298

  12. Formic-acid-induced depolymerization of oxidized lignin to aromatics

    NASA Astrophysics Data System (ADS)

    Rahimi, Alireza; Ulbrich, Arne; Coon, Joshua J.; Stahl, Shannon S.

    2014-11-01

    Lignin is a heterogeneous aromatic biopolymer that accounts for nearly 30% of the organic carbon on Earth and is one of the few renewable sources of aromatic chemicals. As the most recalcitrant of the three components of lignocellulosic biomass (cellulose, hemicellulose and lignin), lignin has been treated as a waste product in the pulp and paper industry, where it is burned to supply energy and recover pulping chemicals in the operation of paper mills. Extraction of higher value from lignin is increasingly recognized as being crucial to the economic viability of integrated biorefineries. Depolymerization is an important starting point for many lignin valorization strategies, because it could generate valuable aromatic chemicals and/or provide a source of low-molecular-mass feedstocks suitable for downstream processing. Commercial precedents show that certain types of lignin (lignosulphonates) may be converted into vanillin and other marketable products, but new technologies are needed to enhance the lignin value chain. The complex, irregular structure of lignin complicates chemical conversion efforts, and known depolymerization methods typically afford ill-defined products in low yields (that is, less than 10-20wt%). Here we describe a method for the depolymerization of oxidized lignin under mild conditions in aqueous formic acid that results in more than 60wt% yield of low-molecular-mass aromatics. We present the discovery of this facile C-O cleavage method, its application to aspen lignin depolymerization, and mechanistic insights into the reaction. The broader implications of these results for lignin conversion and biomass refining are also considered.

  13. Nitric oxide and salicylic acid signaling in plant defense

    PubMed Central

    Klessig, Daniel F.; Durner, Jörg; Noad, Robert; Navarre, Duroy A.; Wendehenne, David; Kumar, Dhirendra; Zhou, Jun Ma; Shah, Jyoti; Zhang, Shuqun; Kachroo, Pradeep; Trifa, Youssef; Pontier, Dominique; Lam, Eric; Silva, Herman

    2000-01-01

    Salicylic acid (SA) plays a critical signaling role in the activation of plant defense responses after pathogen attack. We have identified several potential components of the SA signaling pathway, including (i) the H2O2-scavenging enzymes catalase and ascorbate peroxidase, (ii) a high affinity SA-binding protein (SABP2), (iii) a SA-inducible protein kinase (SIPK), (iv) NPR1, an ankyrin repeat-containing protein that exhibits limited homology to IκBα and is required for SA signaling, and (v) members of the TGA/OBF family of bZIP transcription factors. These bZIP factors physically interact with NPR1 and bind the SA-responsive element in promoters of several defense genes, such as the pathogenesis-related 1 gene (PR-1). Recent studies have demonstrated that nitric oxide (NO) is another signal that activates defense responses after pathogen attack. NO has been shown to play a critical role in the activation of innate immune and inflammatory responses in animals. Increases in NO synthase (NOS)-like activity occurred in resistant but not susceptible tobacco after infection with tobacco mosaic virus. Here we demonstrate that this increase in activity participates in PR-1 gene induction. Two signaling molecules, cGMP and cyclic ADP ribose (cADPR), which function downstream of NO in animals, also appear to mediate plant defense gene activation (e.g., PR-1). Additionally, NO may activate PR-1 expression via an NO-dependent, cADPR-independent pathway. Several targets of NO in animals, including guanylate cyclase, aconitase, and mitogen-activated protein kinases (e.g., SIPK), are also modulated by NO in plants. Thus, at least portions of NO signaling pathways appear to be shared between plants and animals. PMID:10922045

  14. Formic-acid-induced depolymerization of oxidized lignin to aromatics.

    PubMed

    Rahimi, Alireza; Ulbrich, Arne; Coon, Joshua J; Stahl, Shannon S

    2014-11-13

    Lignin is a heterogeneous aromatic biopolymer that accounts for nearly 30% of the organic carbon on Earth and is one of the few renewable sources of aromatic chemicals. As the most recalcitrant of the three components of lignocellulosic biomass (cellulose, hemicellulose and lignin), lignin has been treated as a waste product in the pulp and paper industry, where it is burned to supply energy and recover pulping chemicals in the operation of paper mills. Extraction of higher value from lignin is increasingly recognized as being crucial to the economic viability of integrated biorefineries. Depolymerization is an important starting point for many lignin valorization strategies, because it could generate valuable aromatic chemicals and/or provide a source of low-molecular-mass feedstocks suitable for downstream processing. Commercial precedents show that certain types of lignin (lignosulphonates) may be converted into vanillin and other marketable products, but new technologies are needed to enhance the lignin value chain. The complex, irregular structure of lignin complicates chemical conversion efforts, and known depolymerization methods typically afford ill-defined products in low yields (that is, less than 10-20wt%). Here we describe a method for the depolymerization of oxidized lignin under mild conditions in aqueous formic acid that results in more than 60wt% yield of low-molecular-mass aromatics. We present the discovery of this facile C-O cleavage method, its application to aspen lignin depolymerization, and mechanistic insights into the reaction. The broader implications of these results for lignin conversion and biomass refining are also considered. PMID:25363781

  15. Reduced clearance of triazolam in old age: relation to antipyrine oxidizing capacity.

    PubMed Central

    Greenblatt, D J; Divoll, M; Abernethy, D R; Moschitto, L J; Smith, R B; Shader, R I

    1983-01-01

    Thirty-three healthy male and female volunteers aged 21 to 87 years received a single 0.5 mg oral dose of triazolam. Plasma triazolam concentrations were measured in multiple samples drawn during 24 h after the dose. Mean triazolam elimination half-life was not significantly different between young and elderly men (3.0 vs 4.6 h), nor between young and elderly women (2.7 vs 3.2 h). However, apparent oral clearance of triazolam was significantly reduced in elderly as compared to young groups of both sexes, leading to higher peak plasma concentrations and increased total area under the curve. Values of half-life and clearance of antipyrine, a low-extraction hepatically oxidized compound, were poorly correlated with those of triazolam (r = 0.34 and 0.44, respectively), suggesting different mechanisms controlling age-related changes in clearance of these two hepatically oxidized drugs. PMID:6133545

  16. Thermodynamic Modeling of Sulfide Capacity of Na2O-Containing Oxide Melts

    NASA Astrophysics Data System (ADS)

    Moosavi-Khoonsari, Elmira; Jung, In-Ho

    2016-07-01

    Thermodynamic modeling of the sulfide dissolution in the Na2O-FetO-CaO-MgO-MnO-Al2O3-SiO2 multicomponent slags was performed to investigate the desulfurization of hot metal using Na2O-containing fluxes. The dissolution behavior of sulfur in the melts was modeled using the modified quasi-chemical model in the quadruplet approximation. This model can take into account the short-range ordering and the reciprocal exchange reaction of cations and anions in oxy-sulfide slags. Experimental sulfide capacity data were well predicted from the model with only three model parameters.

  17. Functional characterization of the oxidative capacity of mitochondria and glycolytic assessment in benthic aquatic organisms.

    PubMed

    Atlante, A; Basset, A; Bobba, A; Lassandro, R; Mastrototaro, F; Vignes, F

    2016-06-01

    The metabolism of benthic aquatic invertebrates, populating transitional water ecosystems, is influenced by both physiological and environmental factors, thus involving an adjustment of physiological processes which has a metabolic cost. In order to discover changes in metabolic pathways in response to specific factors, it's firstly necessary characterizing the principal cellular metabolic activities of the small benthic aquatic organisms. We approach here the bioenergetic state issue of two benthic organisms, i.e. Lekanesphaera monodi and Gammarus insensibilis, evidencing that no apparent and statistically significative differences between them in aerobic as well in glycolytic capacities are detected, except for COX activity. PMID:26847717

  18. Regional Variations of Antioxidant Capacity and Oxidative Stress Responses in HIV-1 Transgenic Rats With and Without Methamphetamine Administration

    PubMed Central

    Pang, Xiaosha; Panee, Jun; Liu, Xiangqian; Berry, Marla J.; Chang, Sulie L.; Chang, Linda

    2013-01-01

    HIV infection and methamphetamine (Meth) abuse both may lead to oxidative stress. This study used HIV-1 transgenic (HIV-1Tg) rats to investigate the independent and combined effects of HIV viral protein expression and low dose repeated Meth exposure on the glutathione (GSH)-centered antioxidant system and oxidative stress in the brain. Total GSH content, gene expression and/or enzymatic activities of glutamylcysteine synthetase (GCS), gamma-glutamyltransferase (GGT), glutathione reductase (GR), glutathione peroxidase (GPx), glutaredoxin (Glrx), and glutathione-s-transferase (GST) were measured. The protein expression of cystine transporter (xCT) and oxidative stress marker 4-hydroxynonenal (HNE) were also analyzed. Brain regions studied include thalamus, frontal and remainder cortex, striatum, cerebellum and hippocampus. HIV-1Tg rats and Meth exposure showed highly regional specific responses. In the F344 rats, the thalamus had the highest baseline GSH concentration and potentially higher GSH recycle rate. HIV-1Tg rats showed high transcriptional responses to GSH depletion in the thalamus. Both HIV-1Tg and Meth resulted in decreased GR activity in thalamus, and decreased Glrx activity in frontal cortex. However, the increased GR and Glrx activities synergized with increased GSH concentration, which might have partially prevented Meth-induced oxidative stress in striatum. Interactive effects between Meth and HIV-1Tg were observed in thalamus on the activities of GCS and GGT, and in thalamus and frontal cortex on Glrx activity and xCT protein expression. Findings suggest that HIV viral protein and low dose repeated Meth exposure have separate and combined effects on the brain’s antioxidant capacity and the oxidative stress response that are regional specific. PMID:23546885

  19. Dinuclear copper(II) octaazamacrocyclic complex in a PVC coated GCE and graphite as a voltammetric sensor for determination of gallic acid and antioxidant capacity of wine samples.

    PubMed

    Petković, B B; Stanković, D; Milčić, M; Sovilj, S P; Manojlović, D

    2015-01-01

    A novel efficient differential pulse voltammetric (DPV) method for determination gallic acid (GA) was developed by using an electrochemical sensor based on [Cu2tpmc](ClO4)4 immobilized in PVC matrix and coated on graphite (CGE) or classy carbon rod (CGCE). The proposed method is based on the gallic acid oxidation process at formed [Cu2tpmcGA](3+) complex at the electrode surface. The complexation was explored by molecular modeling and DFT calculations. Voltammograms for both sensors, recorded in a HNO3 as a supporting electrolyte at pH 2 and measured in 2.5×10(-7) to 1.0×10(-4) M of GA, resulted with two linear calibration curves (for higher and lower GA concentration range). The detection limit at CGE was 1.48×10(-7) M, while at CGCE was 4.6×10(-6) M. CGE was successfully applied for the determination of the antioxidant capacity based on GA equivalents for white, rosé and red wine samples. PMID:25476338

  20. Black Conductive Titanium Oxide High-Capacity Materials for Battery Electrodes

    SciTech Connect

    Han, W.

    2011-05-18

    Stoichiometric titanium dioxide (TiO{sub 2}) is one of the most widely studied transitionmetal oxides because of its many potential applications in photoelectrochemical systems, such as dye-sensitized TiO{sub 2} electrodes for photovoltaic solar cells, and water-splitting catalysts for hydrogen generation, and in environmental purification for creating or degrading specific compounds. However, TiO{sub 2} has a wide bandgap and high electrical resistivity, which limits its use as an electrode. A set of non-stoichiometric titanium oxides called the Magneli phases, having a general formula of Ti{sub n}O{sub 2n-1} with n between 4 and 10, exhibits lower bandgaps and resistivities, with the highest electrical conductivities reported for Ti{sub 4}O{sub 7}. These phases have been formulated under different conditions, but in all reported cases the resulting oxides have minimum grain sizes on the order of micrometers, regardless of the size of the starting titanium compounds. In this method, nanoparticles of TiO{sub 2} or hydrogen titanates are first coated with carbon using either wet or dry chemistry methods. During this process the size and shape of the nanoparticles are 'locked in.' Subsequently the carbon-coated nanoparticles are heated. This results in the transformation of the original TiO{sub 2} or hydrogen titanates to Magneli phases without coarsening, so that the original size and shape of the nanoparticles are maintained to a precise degree. People who work on batteries, fuel cells, ultracapacitors, electrosynthesis cells, electro-chemical devices, and soil remediation have applications that could benefit from using nanoscale Magneli phases of titanium oxide. Application of these electrode materials may not be limited to substitution for TiO{sub 2} electrodes. Combining the robustness and photosensitivity of TiO{sub 2} with higher electrical conductivity may result in a general electrode material.

  1. OXIDATION OF NITROPYRIN TO 6-CHOLORPICOLINIC ACID BY THE AMMONIA-OXIDIZING BACTERIUM NOSTROSOMAS EUROPAEA

    EPA Science Inventory

    Suspensions of Nitrosomonas europaea catalyzed the oxidation of the commercial nitrification inhibitor nitrapyrin [2-chloro-6-(trichloromethyl)-pyridine]. apid oxidation of nitrapyrin (at a concentration of 10 uM) required the concomitant oxidation of ammonia, hydroxylamine, or h...

  2. High capacity tin-iron oxide-carbon nanostructured anode for advanced lithium ion battery

    NASA Astrophysics Data System (ADS)

    Verrelli, Roberta; Hassoun, Jusef

    2015-12-01

    A novel nanostructured Sn-Fe2O3-C anode material, prepared by high-energy ball milling, is here originally presented. The anode benefits from a unique morphology consisting in Fe2O3 and Sn active nanoparticles embedded in a conductive buffer carbon matrix of micrometric size. Furthermore, the Sn metal particles, revealed as amorphous according to X-ray diffraction measurement, show a size lower than 10 nm by transmission electron microscopy. The optimal combination of nano-scale active materials and micrometric electrode configuration of the Sn-Fe2O3-C anode reflects into remarkable electrochemical performances in lithium cell, with specific capacity content higher than 900 mAh g-1 at 1C rate (810 mA g-1) and coulombic efficiency approaching 100% for 100 cycles. The anode, based on a combination of lithium conversion, alloying and intercalation reactions, exhibits exceptional rate-capability, stably delivering more than 400 mAh g-1 at the very high current density of 4 A g-1. In order to fully confirm the suitability of the developed Sn-Fe2O3-C material as anode for lithium ion battery, the electrode is preliminarily studied in combination with a high voltage LiNi0.5Mn1.5O4 cathode in a full cell stably and efficiently operating with a 3.7 V working voltage and a capacity exceeding 100 mAh g-1.

  3. Biomass Burning and Natural Emissions in the Amazon Rainforest: Impact on the Oxidative Capacity of the Atmosphere

    NASA Astrophysics Data System (ADS)

    dos Santos, F. C.; Guenther, A. B.; Longo, K.; Freitas, S. R.; Moreira, D. S.; Flávio, L.; Braz, R.; Brito, J.; Oram, D.; Forster, G.; Lee, J. D.; Bauguitte, S.

    2015-12-01

    Terrestrial vegetation, especially tropical forests, releases large amounts of biogenic volatile organic compounds (BVOC) into the atmosphere. The global emissions of BVOC (~1000 Tg C/year) are dominant in relation to anthropogenic volatile organic compounds (~100 Tg C/year), with biomass burning contributing close to 10 - 50 Tg C/year. Tropical trees cover about 18% of the global land surface but are estimated to be responsible for approximately 80% of terpenoid and 50% of other BVOCs emissions. Considering the importance of these emissions, the SAMBBA (South American Biomass Burning Analysis) experiment, which occurred during the dry season (September 2012) in the Amazon Rainforest, provided information about the chemical composition of the atmosphere through measurements on the aircraft FAAM BAE-146. Although primarily focused on biomass burning flights, the SAMBBA project carried out other flights providing indirect oxidative capacity data in different environments: natural emission dominated flights and biomass burning flights with fresh plumes (< 2 hours) and aged plumes (> 2 hours). Calculation of the [MVK+MACR]/[Isoprene] ratio enabled investigation of the impact of biomass burning on surface oxidation in comparison to the natural emission flights. During the morning (altitude < 500m), the [MVK+MACR]/[Isoprene] values for natural emission flights (1.0±0.4), fresh plume (1.9±0.6) and aged plume (1.4±0.6) suggest that biomass burning enhances BVOC oxidation in relation to the lifetime of the air mass. This study aims to improve the knowledge about the oxidative capacity of the atmosphere, which depends not only on chemical composition, but also other factors like the history of the air mass trajectories influencing the availability of these compounds, the NOx dependence of isoprene oxidation and whether the chemistry is dominated by OH or O3. A synergistic approach integrating observation and modeling, using 3D numerical model of chemical transport (CCATT

  4. Modification of vital wheat gluten with phosphoric acid to produce high free-solution capacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat gluten reacts with phosphoric acid to produce natural superabsorbent gels. The gel properties are defined by Fourier Transform Infra-red (FTIR) spectroscopy, 2-dimensional gel electrophoresis (2DE), and uptake of water, salt solutions, and aqueous ethanol. Temperatures above 120'C and dry cond...

  5. Modification of vital wheat gluten with phosphoric acid to produce high free solution capacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat gluten reacts with phosphoric acid in the presence of urea to produce natural superabsorbent gels. Fourier Transform Infra-red (FT-IR) spectroscopy and two-dimensional gel electrophoresis (2DE) reveal chemical changes from the reaction. Temperatures above 120°C and dry conditions create the op...

  6. [Chemico-physical property and bile acid binding capacity of several antacids].

    PubMed

    Salvioli, G; Tambara, E; Gaetti, E; Lugli, R

    1989-01-01

    Liquid alginate (Gaviscon) binds small amount of bile acids. At pH 7 its viscosity (at low shear rate) is higher than that of other antiacids. High viscosity reduces the diffusion rate of bile salts and glucose and this property can play a role in the treatment of gastro-esophageal and duodeno-gastric refluxes. PMID:2548124

  7. Trace H2 O2 -Assisted High-Capacity Tungsten Oxide Electrochromic Batteries with Ultrafast Charging in Seconds.

    PubMed

    Zhao, Jinxiong; Tian, Yuyu; Wang, Zhen; Cong, Shan; Zhou, Di; Zhang, Qingzhu; Yang, Mei; Zhang, Weikun; Geng, Fengxia; Zhao, Zhigang

    2016-06-13

    A recent technological trend in the field of electrochemical energy storage is to integrate energy storage and electrochromism functions in one smart device, which can establish efficient user-device interactions based on a friendly human-readable output. This type of newly born energy storage technology has drawn tremendous attention. However, there is still plenty of room for technological and material innovation, which would allow advancement of the research field. A prototype Al-tungsten oxide electrochromic battery with interactive color-changing behavior is reported. With the assistance of trace amount of H2 O2 , the battery exhibits a specific capacity almost seven times that for the reported electrochromic batteries, up to 429 mAh g(-1) . Fast decoloration of the reduced tungsten oxide affords a very quick charging time of only eight seconds, which possibly comes from an intricate combination of structure and valence state changes of tungsten oxide. This unique combination of features may further advance the development of smart energy storage devices with suitability for user-device interactions. PMID:27159245

  8. Fluorine-Doped and Partially Oxidized Tantalum Carbides as Nonprecious Metal Electrocatalysts for Methanol Oxidation Reaction in Acidic Media.

    PubMed

    Yue, Xin; He, Chunyong; Zhong, Chengyong; Chen, Yuanping; Jiang, San Ping; Shen, Pei Kang

    2016-03-16

    A nonprecious metal electrocatalyst based on fluorine-doped tantalum carbide with an oxidative surface on graphitized carbon (TaCx FyOz/(g)C) is developed by using a simple one-pot in situ ion exchange and adsorption method, and the TaCxFyOz/(g)C shows superior performance and durability for methanol oxidation reaction and extreme tolerance to CO poisoning in acidic media. PMID:26779940

  9. Changes in lipid composition, fatty acid profile and lipid oxidative stability during Cantonese sausage processing.

    PubMed

    Qiu, Chaoying; Zhao, Mouming; Sun, Weizheng; Zhou, Feibai; Cui, Chun

    2013-03-01

    Lipid composition, fatty acid profile and lipid oxidative stability were evaluated during Cantonese sausage processing. Free fatty acids increased with concomitant decrease of phospholipids. Total content of free fatty acids at 72 h in muscle and adipose tissue was 7.341 mg/g and 3.067 mg/g, respectively. Total amount of saturated, monounsaturated and polyunsaturated fatty acids (SFA, MUFA, and PUFA) in neutral lipid exhibited a little change during processing, while the proportion of PUFA significantly decreased in the PL fraction. The main triacylglycerols were POO+SLO+OOO, PSO (P = palmitic acid, O = oleic acid, L = linoleic acid, S = stearic acid), and a preferential hydrolysis of palmitic, oleic and linoleic acid was observed. Phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the main components of phospholipids and PE exhibited the most significant degradation during processing. Thiobarbituric acid values (TBARS) increased while peroxide values and hexanal contents varied during processing. PMID:23273460

  10. Ozonization of humic acids in brown coal oxidized in situ

    SciTech Connect

    S.A. Semenova; Yu.F. Patrakov; M.V. Batina

    2008-10-15

    The effect of the ozonization of humic acids in chloroform and glacial acetic acid media on the yield and component composition of the resulting products was studied. The high efficiency of ozonization in acetic acid was found. Water-soluble low-molecular-weight substances were predominant among the ozonization products.

  11. Protective effect of curcumin on cyclosporin A-induced endothelial dysfunction, antioxidant capacity, and oxidative damage.

    PubMed

    Sagiroglu, Tamer; Kanter, Mehmet; Yagci, Mehmet Ali; Sezer, Atakan; Erboga, Mustafa

    2014-05-01

    Cyclosporin A (CsA) is the most widely used immunosuppressive drug for preventing graft rejection and autoimmune disease. However, the therapeutic treatment induces several side effects such as nephrotoxicity, cardiotoxicity, hypertension, and hepatotoxicity. Curcumin has been successfully used as a potent antioxidant against many pathophysiological states. This experimental study was performed to test, during CsA treatment, the alterations of curcumin antioxidant properties against CsA-induced endothelial dysfunction. Rats were divided into four groups: control, curcumin alone, CsA, and CsA + curcumin; each group containing eight animals. The animals in the CsA + curcumin group were treated with CsA (10 days, 25 mg/kg, orally) and curcumin (15 days, 200 mg/kg, orally, starting 5 days before CsA administration). At the end of the treatments, the animals were killed; serum and aorta tissue were treated for biochemical and morphological analyses. The results indicate that CsA-induced aortic endothelial dysfunction was characterized by morphological and ultrastructural alterations in tissue architecture, changes in malondialdehyde and ferric reducing/antioxidant power levels, and increase in endothelial nitric oxide synthase and terminal-deoxynucleotidyl-transferase mediated dUTP nick end labeling (TUNEL) expression. In conclusion, our data suggest that the imbalance between production of free oxygen radicals and antioxidant defence systems, due to CsA administration, is a mechanism responsible for oxidative stress. Moreover, we show that curcumin plays a protective action against CsA-induced endothelial dysfunction and oxidative stress, as supported by biochemical, ultrastructural, immunohistochemical, and TUNEL results. PMID:22903178

  12. Preparation of mesoporous poly (acrylic acid)/SiO2 composite nanofiber membranes having adsorption capacity for indigo carmine dye

    NASA Astrophysics Data System (ADS)

    Xu, Ran; Jia, Min; Li, Fengting; Wang, Hongtao; Zhang, Bingru; Qiao, Junlian

    2012-03-01

    Mesoporous poly (acrylic acid)/SiO2 (PAA/SiO2) composite nanofiber membranes functionalized with mercapto groups were fabricated by a sol-gel electrospinning method, and their adsorption capacity for indigo carmine was investigated. The membranes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray powder diffraction (XRD), and nitrogen adsorption-desorption measurement. SEM and TEM observation results showed that the PAA/SiO2 fibers had diameters between 400-800 nm and mesopores with an average pore size of 3.88 nm. The specific surface area of the mesoporous nanofiber membranes was 514.89 m2/g. The characteristic peaks for mercapto group vibration in FTIR and Raman spectra demonstrated that the mercapto groups have been incorporated into the silica skeleton. The adsorption isotherm data of indigo carmine on the membranes fit well with Redlich-Peterson model, and the maximum adsorption capacity calculated was 523.11 mg/g. It was found that the removal rate of indigo carmine by the membranes reached a maximum of 98% in 90 min and the adsorption kinetics followed a pseudo-second-order model. The high adsorption capacity of PAA/SiO2 nanofiber membrane makes it a promising adsorbent for indigo carmine removal from the wastewater.

  13. Mesoporous biocompatible and acid-degradable magnetic colloidal nanocrystal clusters with sustainable stability and high hydrophobic drug loading capacity.

    PubMed

    Luo, Bin; Xu, Shuai; Luo, An; Wang, Wen-Rui; Wang, Shi-Long; Guo, Jia; Lin, Yao; Zhao, Dong-Yuan; Wang, Chang-Chun

    2011-02-22

    Fabrication of magnetic particles (MPs) with high magnetization and large surface area simultaneously is critical for the application of MPs in bioseparation and drug delivery but remains a challenge. In this article, we describe an unprecedented approach to synthesize mesoporous magnetic colloidal nanocrystal clusters (MCNCs) stabilized by poly(γ-glutamic acid) (PGA) with high magnetization, large surface area (136 m(2)/g) and pore volume (0.57 cm(3)/g), excellent colloidal stability, prominent biocompatibility, and acid degradability. This result provides the important step toward the construction of a new family of MCNCs and demonstrates its capacity in a "magnetic motor" drug delivery system. Here, as an example, we explore the applicability of as-prepared mesoporous MCNCs as hydrophobic drug delivery vehicles (paclitaxel as model drug), and the resultant loading capacity is as high as 35.0 wt %. The antitumor efficacy measured by MTT assay is significantly enhanced, compared with free drugs. Thus, combined with their inherent high magnetization, the mesoporous MCNCs pave the way for applying magnetic targeting drug carriers in antitumor therapeutics. PMID:21284377

  14. Iron Catalysis for Room-Temperature Aerobic Oxidation of Alcohols to Carboxylic Acids.

    PubMed

    Jiang, Xingguo; Zhang, Jiasheng; Ma, Shengming

    2016-07-13

    Oxidation from alcohols to carboxylic acids, a class of essential chemicals in daily life, academic laboratories, and industry, is a fundamental reaction, usually using at least a stoichiometric amount of an expensive and toxic oxidant. Here, an efficient and practical sustainable oxidation technology of alcohols to carboxylic acids using pure O2 or even O2 in air as the oxidant has been developed: utilizing a catalytic amount each of Fe(NO3)3·9H2O/TEMPO/MCl, a series of carboxylic acids were obtained from alcohols (also aldehydes) in high yields at room temperature. A 55 g-scale reaction was demonstrated using air. As a synthetic application, the first total synthesis of a naturally occurring allene, i.e., phlomic acid, was accomplished. PMID:27304226

  15. Fatty acids and oxidative stability of meat from lambs fed carob-containing diets.

    PubMed

    Gravador, Rufielyn S; Luciano, Giuseppe; Jongberg, Sisse; Bognanno, Matteo; Scerra, Manuel; Andersen, Mogens L; Lund, Marianne N; Priolo, Alessandro

    2015-09-01

    Male Comisana lambs were individually stalled and, for 56 days, were fed concentrates with 60% barley (n = 8 lambs), or concentrates in which barley was partially replaced by 24% or 35% carob pulp (n = 9 lambs in each group). The intramuscular fatty acids were analyzed and the color stability, lipid and protein oxidation were measured in fresh meat overwrapped with polyvinyl chloride film at 0, 3 or 6 days of storage at 4 °C in the dark. Carob pulp increased the concentration of polyunsaturated fatty acids (PUFA) in muscle, including the rumenic acid (P < 0.01), and reduced the saturated fatty acids (P < 0.01) and the n-6/n-3 PUFA ratio (P = 0.01). The meat did not undergo extensive oxidative deterioration and the diet did not affect the oxidative stability parameters. Therefore, carob in lamb diet could increase PUFA in muscle without compromising meat oxidative stability. PMID:25842304

  16. Isotope composition of sulphate in acid mine drainage as measure of bacterial oxidation

    USGS Publications Warehouse

    Taylor, B.E.; Wheeler, M.C.; Nordstrom, D.K.

    1984-01-01

    The formation of acid waters by oxidation of pyrite-bearing ore deposits, mine tailing piles, and coal measures is a complex biogeochemical process and is a serious environmental problem. We have studied the oxygen and sulphur isotope geochemistry of sulphides, sulphur, sulphate and water in the field and in experiments to identify sources of oxygen and reaction mechanisms of sulphate formation. Here we report that the oxygen isotope composition of sulphate in acid mine drainage shows a large variation due to differing proportions of atmospheric- and water-derived oxygen from both chemical and bacterially-mediated oxidation. 18O-enrichment of sulphate results from pyrite oxidation facilitated by Thiobacillus ferrooxidans in aerated environments. Oxygen isotope analysis may therefore be useful in monitoring the effectiveness of abatement programmes designed to inhibit bacterial oxidation. Sulphur isotopes show no significant fractionation between pyrite and sulphate, indicating the quantitative insignificance of intermediate oxidation states of sulphur under acid conditions. ?? 1984 Nature Publishing Group.

  17. Electrochemical oxidation of 2,4,5-trichlorophenoxyacetic acid by metal-oxide-coated Ti electrodes.

    PubMed

    Maharana, Dusmant; Xu, Zesheng; Niu, Junfeng; Rao, Neti Nageswara

    2015-10-01

    Electrochemical oxidation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) over metal-oxide-coated Ti anodes, i.e., Ti/SnO2-Sb/Ce-PbO2, Ti/SnO2-Sb and Ti/RuO2, was examined. The degradation efficiency of over 90% was attained at 20 min at different initial concentrations (0.5-20 mg L(-1)) and initial pH values (3.1-11.2). The degradation efficiencies of 2,4,5-T on Ti/SnO2-Sb/Ce-PbO2, Ti/SnO2-Sb and Ti/RuO2 anodes were higher than 99.9%, 97.2% and 91.5% at 30 min, respectively, and the respective total organic carbon removal ratios were 65.7%, 54.6% and 37.2%. The electrochemical degradation of 2,4,5-T in aqueous solution followed pseudo-first-order kinetics. The compounds, i.e., 2,5-dichlorohydroquinone and 2,5-dihydroxy-p-benzoquinone, have been identified as the main aromatic intermediates by liquid chromatography-mass spectrometry. The results showed that the energy efficiencies of 2,4,5-T (20 mg L(-1)) degradation with Ti/SnO2-Sb/Ce-PbO2 anode at the optimal current densities from 2 to 16 mA cm(-2) ranged from 8.21 to 18.73 kWh m(-3). PMID:25981800

  18. Evidence for Physical Association of Mitochondrial Fatty Acid Oxidation and Oxidative Phosphorylation Complexes

    PubMed Central

    Wang, Yudong; Mohsen, Al-Walid; Mihalik, Stephanie J.; Goetzman, Eric S.; Vockley, Jerry

    2010-01-01

    Fatty acid β-oxidation (FAO) and oxidative phosphorylation (OXPHOS) are key pathways involved in cellular energetics. Reducing equivalents from FAO enter OXPHOS at the level of complexes I and III. Genetic disorders of FAO and OXPHOS are among the most frequent inborn errors of metabolism. Patients with deficiencies of either FAO or OXPHOS often show clinical and/or biochemical findings indicative of a disorder of the other pathway. In this study, the physical and functional interactions between these pathways were examined. Extracts of isolated rat liver mitochondria were subjected to blue native polyacrylamide gel electrophoresis (BNGE) to separate OXPHOS complexes and supercomplexes followed by Western blotting using antisera to various FAO enzymes. Extracts were also subjected to sucrose density centrifugation and fractions analyzed by BNGE or enzymatic assays. Several FAO enzymes co-migrated with OXPHOS supercomplexes in different patterns in the gels. When palmitoyl-CoA was added to the sucrose gradient fractions containing OXPHOS supercomplexes in the presence of potassium cyanide, cytochrome c was reduced. Cytochrome c reduction was completely blocked by myxothiazol (a complex III inhibitor) and 3-mercaptopropionate (an inhibitor of the first step of FAO), but was only partially inhibited by rotenone (a complex I inhibitor). Although palmitoyl-CoA and octanoyl-CoA provided reducing equivalents to OXPHOS-containing supercomplex fractions, no accumulation of their intermediates was detected. In contrast, short branched acyl-CoA substrates were not metabolized by OXPHOS-containing supercomplex fractions. These data provide evidence of a multifunctional FAO complex within mitochondria that is physically associated with OXPHOS supercomplexes and promotes metabolic channeling. PMID:20663895

  19. A 9-wk docosahexaenoic acid-enriched supplementation improves endurance exercise capacity and skeletal muscle mitochondrial function in adult rats.

    PubMed

    Le Guen, Marie; Chaté, Valérie; Hininger-Favier, Isabelle; Laillet, Brigitte; Morio, Béatrice; Pieroni, Gérard; Schlattner, Uwe; Pison, Christophe; Dubouchaud, Hervé

    2016-02-01

    Decline in skeletal muscle mass and function starts during adulthood. Among the causes, modifications of the mitochondrial function could be of major importance. Polyunsaturated fatty (ω-3) acids have been shown to play a role in intracellular functions. We hypothesize that docosahexaenoic acid (DHA) supplementation could improve muscle mitochondrial function that could contribute to limit the early consequences of aging on adult muscle. Twelve-month-old male Wistar rats were fed a low-polyunsaturated fat diet and were given DHA (DHA group) or placebo (control group) for 9 wk. Rats from the DHA group showed a higher endurance capacity (+56%, P < 0.05) compared with control animals. Permeabilized myofibers from soleus muscle showed higher O2 consumptions (P < 0.05) in the DHA group compared with the control group, with glutamate-malate as substrates, both in basal conditions (i.e., state 2) and under maximal conditions (i.e., state 3, using ADP), along with a higher apparent Km for ADP (P < 0.05). Calcium retention capacity of isolated mitochondria was lower in DHA group compared with the control group (P < 0.05). Phospho-AMPK/AMPK ratio and PPARδ mRNA content were higher in the DHA group compared with the control group (P < 0.05). Results showed that DHA enhanced endurance capacity in adult animals, a beneficial effect potentially resulting from improvement in mitochondrial function, as suggested by our results on permeabilized fibers. DHA supplementation could be of potential interest for the muscle function in adults and for fighting the decline in exercise tolerance with age that could imply energy-sensing pathway, as suggested by changes in phospho-AMPK/AMPK ratio. PMID:26646102

  20. Phagocytosis of hybrid molecular nanosomal compositions containing oxidized dextrans conjugated with isonicotinic acid hydrazide by macrophages.

    PubMed

    Shkurupy, V A; Arkhipov, S A; Troitsky, A V; Luzgina, N G; Zaikovskaja, M V; Ufimceva, E G; Iljine, D A; Akhramenko, E S; Gulyaeva, E P; Bistrova, T N

    2009-12-01

    We studied phagocytic activity of macrophages towards hybrid molecular nanosomal compositions consisting of 150-800-nm nanoliposomes containing oxidized dextrans with a molecular weight of 35 and 60 kDa obtained by chemical ("permanganate") and radiochemical oxidation of dextran conjugated with isonicotinic acid hydrazide (dextrazides, intracellular prolonged antituberculous drugs). Phagocytic activity of macrophages towards hybrid molecular nanosomal compositions containing dextrazides obtained by chemical oxidation of dextrans is higher than activity towards hybrid molecular nanosomal compositions containing dextrazides prepared by radiochemical oxidation and depends on the size of hybrid molecular nanosomal compositions and molecular weight of oxidized dextrans. PMID:21116494

  1. Versatile Redox Chemistry Complicates Antioxidant Capacity Assessment: Flavonoids as Milieu-Dependent Antiand Pro-Oxidants

    PubMed Central

    Chobot, Vladimir; Kubicova, Lenka; Bachmann, Gert; Hadacek, Franz

    2013-01-01

    Some antioxidants have been shown to possess additional pro-oxidant effects. Diverse methodologies exist for studying redox properties of synthetic and natural chemicals. The latter are substantial components of our diet. Exploration of their contribution to life-extending or -compromising effects is mandatory. Among reactive oxygen species (ROS), hydroxyl radical (•OH) is the most damaging species. Due to its short half-life, the assay has to contain a specific generation system. Plants synthesize flavonoids, phenolic compounds recognized as counter-agents to coronary heart disease. Their antioxidant activities are affected by their hydroxylation patterns. Moreover, in the plant, they mainly occur as glycosides. We chose three derivatives, quercetin, luteolin, and rutin, in attempts to explore their redox chemistry in contrasting hydrogen peroxide environments. Initial addition of hydrogen peroxide in high concentration or gradual development constituted a main factor affecting their redox chemical properties, especially in case of quercetin. Our study exemplifies that a combination of a chemical assay (deoxyribose degradation) with an electrochemical method (square-wave voltammetry) provides insightful data. The ambiguity of the tested flavonoids to act either as anti- or pro-oxidant may complicate categorization, but probably contributed to their evolution as components of a successful metabolic system that benefits both producer and consumer. PMID:23736691

  2. Novel amino acids: synthesis of furoxan and sydnonimine containing amino acids and peptides as potential nitric oxide releasing motifs.

    PubMed

    Nortcliffe, Andrew; Botting, Nigel P; O'Hagan, David

    2013-07-28

    The incorporation of furoxan and sydnonimine ring systems into amino acid side chains is demonstrated with the preparation of four novel amino acids which carry these nitric oxide-releasing motifs. N-((4-Nitrophenoxy)carbonyl)-3-phenylsydnonimine 9 and bis(phenylsulfonyl)furoxan 10 are the key intermediates for introducing the heterocycle side chains onto appropriate amine and alcohol functionalities respectively. Furoxan 5 and 7 both displayed NO release based on determination of nitrite production. Orthogonal amino acid protecting group strategies were deployed to demonstrate that the amino acids could be incorporated into peptide frameworks. By way of demonstration the amino acids were placed centrally into several tripeptide motifs. Griess test assays showed that these amino acids released NO in the presence of γ-glutathione (GST). PMID:23753002

  3. Omega-3 fatty acids differentially modulate enzymatic anti-oxidant systems in skeletal muscle cells.

    PubMed

    da Silva, E P; Nachbar, R T; Levada-Pires, A C; Hirabara, S M; Lambertucci, R H

    2016-01-01

    During physical activity, increased reactive oxygen species production occurs, which can lead to cell damage and in a decline of individual's performance and health. The use of omega-3 polyunsaturated fatty acids as a supplement to protect the immune system has been increasing; however, their possible benefit to the anti-oxidant system is not well described. Thus, the aim of this study was to evaluate whether the omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) can be beneficial to the anti-oxidant system in cultured skeletal muscle cells. C2C12 myocytes were differentiated and treated with either eicosapentaenoic acid or docosahexaenoic acid for 24 h. Superoxide content was quantified using the dihydroethidine oxidation method and superoxide dismutase, catalase, and glutathione peroxidase activity, and expression was quantified. We observed that the docosahexaenoic fatty acids caused an increase in superoxide production. Eicosapentaenoic acid induced catalase activity, while docosahexaenoic acid suppressed superoxide dismutase activity. In addition, we found an increased protein expression of the total manganese superoxide dismutase and catalase enzymes when cells were treated with eicosapentaenoic acid. Taken together, these data indicate that the use of eicosapentaenoic acid may present both acute and chronic benefits; however, the treatment with DHA may not be beneficial to muscle cells. PMID:26386577

  4. Relationship between antioxidant capacity, oxidative stress, and feed efficiency in beef steers.

    PubMed

    Russell, J R; Sexten, W J; Kerley, M S; Hansen, S L

    2016-07-01

    Feed efficiency (FE) can vary between individuals but sources of variation are not well characterized. Oxidative stress is among the biological mechanisms believed to contribute to variation. The objective of this study was to evaluate the relationship between FE, antioxidant activity, and oxidative stress in feedlot steers representing phenotypic extremes for FE. Crossbred beef steers ( = 181) fed 70-d growing phase (GP) whole-shell corn-based (G-Corn) or rye baleage and soybean hull-based (G-Rough) diets in GrowSafe bunks at the University of Missouri were shipped to Iowa State University where the 12 most feed efficient (HFE) and 12 least feed efficient (LFE) steers from each diet (n = 48; 467 kg [SD 51]) were selected for evaluation. Steers received diets similar to GP diets, and 3 d after arrival, blood was sampled to evaluate antioxidant activity and oxidative stress markers for the GP following transit. Steers were transitioned to finishing phase (FP) cracked corn-based (F-Corn) or dried distillers' grains and soybean hull-based (F-Byp) diets, and on FP d 97, blood samples for the FP were collected. Data for the GP were analyzed as a 2 × 2 factorial, and data for the FP were analyzed as a 2 × 2 × 2 factorial using PROC MIXED of SAS. No GP diet × FP diet, FP diet × FE group, or 3-way interactions were noted ( ≥ 0.11) for FP measures. Steers fed the G-Rough diet had greater ( = 0.04) GP plasma protein carbonyl concentrations. During the GP, HFE steers had greater ( ≤ 0.04) protein carbonyl and ratio of oxidized:reduced blood lysate glutathione concentrations than LFE steers. There were GP diet × FE group interactions ( ≤ 0.03) during the GP and FP. During the GP, total blood lysate superoxide dismutase (SOD) activity was greater ( ≤ 0.03) in G-Rough/LFE steers than in G-Rough/HFE and G-Corn/LFE steers; G-Corn/HFE steers were intermediate. The G-Rough/LFE steers had greater ( < 0.04) glutathione peroxidase (GPX) activity than other groups and

  5. Investigations of the oxidation capacities of polar atmospheres with multiple oxygen isotopes

    NASA Astrophysics Data System (ADS)

    McCabe, Justin R.

    This study provides new perspectives on the atmospheric chemistry in Polar Regions using multiple oxygen isotopes of nitrate and sulfate. Despite their remote locations, these unique environments play an important role in the present state of global climate and contain invaluable clues to observing past relationships between earth's atmosphere and surface temperature. With current temperatures and greenhouse gas concentrations rising rapidly as a result of human activities, continued investigation of the effects on polar environments will elucidate their relationship to the global climate system. Three studies are presented here to constrain the oxidation pathways of nitrogen and sulfur compounds in polar atmospheres. These findings provide a new means to observe current and past oxidation conditions of tropospheric and stratospheric polar atmospheres. Currently, two uncertain aspects of climate are the projected changes in tropospheric and stratospheric oxidation chemistry and the role of aerosols in cloud formation and the global radiation budget. Because the levels of oxidants in the atmosphere directly influence greenhouse gas concentrations and aerosol distribution, the following work presents results implicit to improving knowledge of the climate system. The results presented in this dissertation include measurements of oxygen isotopes (delta17O, delta18O, and Delta 17O) in nitrate and sulfate from South Pole, Antarctica and Alert, Canada, respectively. In addition, a photochemistry experiment was conducted to measure the effects of ultraviolet (UV) irradiation on oxygen isotopes of nitrate in water and ice. Chapter 2 compares oxygen isotopes in sulfate aerosol collected at Alert, Canada over the course of one year (July 1999--June 2000) to a chemical transport model describing sulfate formation. Chapter 3 presents the results from the nitrate photochemistry experiments conducted at California Institute of Technology in Pasadena, California. Chapter 4

  6. Measurement of Fatty Acid Oxidation Rates in Animal Tissues and Cell Lines

    PubMed Central

    Huynh, Frank K.; Green, Michelle F.; Koves, Timothy R.; Hirschey, Matthew D.

    2014-01-01

    While much oncological research has focused on metabolic shifts in glucose and amino acid oxidation, recent evidence suggests that fatty acid oxidation (FAO) may also play an important role in the metabolic reprogramming of cancer cells. Here, we present a simple method for measuring FAO rates using radiolabeled palmitate, common laboratory reagents, and standard supplies. This protocol is broadly applicable for measuring FAO rates in cultured cancer cells as well as in both malignant and nontransformed animal tissues. PMID:24862277

  7. Aerosol Disinfection Capacity of Slightly Acidic Hypochlorous Acid Water Towards Newcastle Disease Virus in the Air: An In Vivo Experiment.

    PubMed

    Hakim, Hakimullah; Thammakarn, Chanathip; Suguro, Atsushi; Ishida, Yuki; Nakajima, Katsuhiro; Kitazawa, Minori; Takehara, Kazuaki

    2015-12-01

    Existence of bioaerosol contaminants in farms and outbreaks of some infectious organisms with the ability of transmission by air increase the need for enhancement of biosecurity, especially for the application of aerosol disinfectants. Here we selected slightly acidic hypochlorous acid water (SAHW) as a candidate and evaluated its virucidal efficacy toward a virus in the air. Three-day-old conventional chicks were challenged with 25 doses of Newcastle disease live vaccine (B1 strain) by spray with nebulizer (particle size <3 μm in diameter), while at the same time reverse osmosis water as the control and SAHW containing 50 or 100 parts per million (ppm) free available chlorine in pH 6 were sprayed on the treated chicks with other nebulizers. Exposed chicks were kept in separated cages in an isolator and observed for clinical signs. Oropharyngeal swab samples were collected from 2 to 5 days postexposure from each chick, and then the samples were titrated with primary chicken kidney cells to detect the virus. Cytopathic effects were observed, and a hemagglutination test was performed to confirm the result at 5 days postinoculation. Clinical signs (sneezing) were recorded, and the virus was isolated from the control and 50 ppm treatment groups, while no clinical signs were observed in and no virus was isolated from the 100 ppm treatment group. The virulent Newcastle disease virus (NDV) strain Sato, too, was immediately inactivated by SAHW containing 50 ppm chlorine in the aqueous phase. These data suggest that SAHW containing 100 ppm chlorine can be used for aerosol disinfection of NDV in farms. PMID:26629621

  8. Lichen acids as uncouplers of oxidative phosphorylation of mouse-liver mitochondria.

    PubMed

    Abo-Khatwa, A N; al-Robai, A A; al-Jawhari, D A

    1996-01-01

    Three lichen acids-namely, (+)usnic acid, vulpinic acid, and atranorin-were isolated from three lichen species (Usnea articulata, Letharia vulpina, and Parmelia tinctorum, respectively). The effects of these lichen products on mice-liver mitochondrial oxidative functions in various respiratory states and on oxidative phosphorylation were studied polarographically in vitro. The lichen acids exhibited characteristics of the 2,4-dinitrophenol (DNP), a classical uncoupler of oxidative phosphorylation. Thus, they released respiratory control and oligomycin inhibited respiration, hindered ATP synthesis, and enhanced Mg(+2)-ATPase activity. (+)Usnic acid at a concentration of 0.75 microM inhibited ADP/O ratio by 50%, caused maximal stimulation of both state-4 respiration (100%) and ATPase activity (300%). Atranorin was the only lichen acid with no significant effect on ATPase. The uncoupling effect was dose-dependent in all cases. The minimal concentrations required to cause complete uncoupling of oxidative phosphorylation were as follows: (+)usnic acid (1 microM), vulpinic acid, atranorin (5 microM) and DNP (50 microM). It was postulated that the three lichen acids induce uncoupling by acting on the inner mitochondrial membrane through their lipophilic properties and protonophoric activities. PMID:8726330

  9. Biological implications of oxidation and unidirectional chiral inversion of D-amino acids.

    PubMed

    Wang, Yong-Xiang; Gong, Nian; Xin, Yan-Fei; Hao, Bin; Zhou, Xiang-Jun; Pang, Catherine C Y

    2012-03-01

    Recent progress in chiral separation of D- and L-amino acids by chromatography ascertained the presence of several free Damino acids in a variety of mammals including humans. Unidirectional chiral inversion of many D-amino acid analogs such as exogenous NG-nitro-D-arginine (D-NNA), endogenous D-leucine, D-phenylanine and D-methionine have been shown to take place with inversion rates of 4-90%, probably dependent on various species D-amino acid oxidase (DAAO) enzymatic activities. DAAO is known to catalyze the oxidative deamination of neutral and basic D-amino acids to their corresponding α-keto acids, hydrogen peroxide and ammonia, and is responsible for the chiral inversion. This review provides an overview of recent research in this area: 1) oxidation and chiral inversion of several D-amino acid analogs in the body; 2) the indispensable but insufficient role of DAAO particularly in the kidneys and brain for the oxidation and chiral inversion of D-amino acids analogs; and 3) unidentified transaminase(s) responsible for the second step of chiral inversion. The review also discusses the physiological significance of oxidation and chiral inversion of D-amino acids, which is still a subject of dispute. PMID:22304623

  10. The influence of oxidation with nitric acid on the preparation and properties of active carbon enriched in nitrogen

    NASA Astrophysics Data System (ADS)

    Pietrzak, Robert; Nowicki, Piotr; Wachowska, Helena

    2009-01-01

    The effect of oxidation by 20% nitric acid on the properties and performance of active carbons enriched with nitrogen by means of the reaction with urea in the presence of air has been studied. The study has been made on demineralised orthocoking coal and the carbonisates obtained from it at 600 or 700 °C, subjected to the processes of nitrogenation, oxidation and activation with KOH in different sequences. The amount of nitrogen introduced into the carbon with the aid of urea has been found to depend on the stage at which the process of nitrogenation was performed. The process of oxidation of the demineralised coal and the active carbon obtained from the former has been found to favour nitrogen introduction into the carbon structure. In the process of nitrogenation of the carbonisates the amount of nitrogen introduced has inversely depended on the temperature of carbonisation. The modifications of the processes permitted obtaining materials of different textural parameters, different acid-base character of the surface and different iodine sorption capacity.

  11. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    NASA Technical Reports Server (NTRS)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

  12. Phytoagents for Cancer Management: Regulation of Nucleic Acid Oxidation, ROS, and Related Mechanisms

    PubMed Central

    Shyur, Lie-Fen

    2013-01-01

    Accumulation of oxidized nucleic acids causes genomic instability leading to senescence, apoptosis, and tumorigenesis. Phytoagents are known to reduce the risk of cancer development; whether such effects are through regulating the extent of nucleic acid oxidation remains unclear. Here, we outlined the role of reactive oxygen species in nucleic acid oxidation as a driving force in cancer progression. The consequential relationship between genome instability and cancer progression highlights the importance of modulation of cellular redox level in cancer management. Current epidemiological and experimental evidence demonstrate the effects and modes of action of phytoagents in nucleic acid oxidation and provide rationales for the use of phytoagents as chemopreventive or therapeutic agents. Vitamins and various phytoagents antagonize carcinogen-triggered oxidative stress by scavenging free radicals and/or activating endogenous defence systems such as Nrf2-regulated antioxidant genes or pathways. Moreover, metal ion chelation by phytoagents helps to attenuate oxidative DNA damage caused by transition metal ions. Besides, the prooxidant effects of some phytoagents pose selective cytotoxicity on cancer cells and shed light on a new strategy of cancer therapy. The “double-edged sword” role of phytoagents as redox regulators in nucleic acid oxidation and their possible roles in cancer prevention or therapy are discussed in this review. PMID:24454991

  13. Phytoagents for cancer management: regulation of nucleic acid oxidation, ROS, and related mechanisms.

    PubMed

    Lee, Wai-Leng; Huang, Jing-Ying; Shyur, Lie-Fen

    2013-01-01

    Accumulation of oxidized nucleic acids causes genomic instability leading to senescence, apoptosis, and tumorigenesis. Phytoagents are known to reduce the risk of cancer development; whether such effects are through regulating the extent of nucleic acid oxidation remains unclear. Here, we outlined the role of reactive oxygen species in nucleic acid oxidation as a driving force in cancer progression. The consequential relationship between genome instability and cancer progression highlights the importance of modulation of cellular redox level in cancer management. Current epidemiological and experimental evidence demonstrate the effects and modes of action of phytoagents in nucleic acid oxidation and provide rationales for the use of phytoagents as chemopreventive or therapeutic agents. Vitamins and various phytoagents antagonize carcinogen-triggered oxidative stress by scavenging free radicals and/or activating endogenous defence systems such as Nrf2-regulated antioxidant genes or pathways. Moreover, metal ion chelation by phytoagents helps to attenuate oxidative DNA damage caused by transition metal ions. Besides, the prooxidant effects of some phytoagents pose selective cytotoxicity on cancer cells and shed light on a new strategy of cancer therapy. The "double-edged sword" role of phytoagents as redox regulators in nucleic acid oxidation and their possible roles in cancer prevention or therapy are discussed in this review. PMID:24454991

  14. Synergistic interaction between oxides of copper and iron for production of fatty alcohols from fatty acids

    DOE PAGESBeta

    Kandel, Kapil; Chaudhary, Umesh; Nelson, Nicholas C.; Slowing, Igor I.

    2015-10-08

    In this study, the selective hydrogenation of fatty acids to fatty alcohols can be achieved under moderate conditions (180 °C, 30 bar H2) by simultaneously supporting copper and iron oxides on mesoporous silica nanoparticles. The activity of the cosupported oxides is significantly higher than that of each supported metal oxide and of a physical mixture of both individually supported metal oxides. A strong interaction between both metal oxides is evident from dispersion, XRD, TPR, and acetic acid TPD measurements, which is likely responsible for the synergistic behavior of the catalyst. Copper oxide is reduced in situ to its metallic formmore » and thereby activates hydrogen.« less

  15. Synergistic interaction between oxides of copper and iron for production of fatty alcohols from fatty acids

    SciTech Connect

    Kandel, Kapil; Chaudhary, Umesh; Nelson, Nicholas C.; Slowing, Igor I.

    2015-10-08

    In this study, the selective hydrogenation of fatty acids to fatty alcohols can be achieved under moderate conditions (180 °C, 30 bar H2) by simultaneously supporting copper and iron oxides on mesoporous silica nanoparticles. The activity of the cosupported oxides is significantly higher than that of each supported metal oxide and of a physical mixture of both individually supported metal oxides. A strong interaction between both metal oxides is evident from dispersion, XRD, TPR, and acetic acid TPD measurements, which is likely responsible for the synergistic behavior of the catalyst. Copper oxide is reduced in situ to its metallic form and thereby activates hydrogen.

  16. Maternal dietary fat affects milk fatty acid profile and impacts on weight gain and thermogenic capacity of suckling rats.

    PubMed

    Priego, Teresa; Sánchez, Juana; García, Ana Paula; Palou, Andreu; Picó, Catalina

    2013-05-01

    We aimed to assess the effects of maternal supplementation with the main fat sources used in the human Western diet (olive oil, butter, margarine) on milk FA composition and on plasma FA profile of offspring, and to determine whether it may influence body-weight-gain (BWG) and adiposity of offspring during the suckling period. Wistar rats were supplemented with the different fat sources from day 14 of gestation and throughout lactation. Olive oil-supplemented dams showed the highest proportion of oleic-acid in milk, with no changes in plasma. Their offspring also showed the highest proportion of this FA in plasma, lower BWG during the suckling period, and higher levels of UCP1 in brown adipose tissue (BAT) at weaning. Margarine-supplemented dams showed the highest percentage of PUFA in milk, and a similar tendency was found in plasma of their offspring. Butter-supplemented dams displayed higher proportion of saturated FA (SFA) in milk compared to other fat-supplemented dams, but lower than controls. Control offspring also showed higher proportion of SFA in plasma and greater BWG during the suckling period than fat-supplemented groups. Significant correlations were found between the relative content of some milk FA and BWG of offspring, in particular, oleic-acid levels correlated negatively with BWG and positively with UCP1 levels. These results show that maternal dietary source of fat affects milk FA composition and circulating FA profile, as could be expected, but also BWG and thermogenic capacity of offspring during the suckling period. An effect of oleic-acid stimulating BAT thermogenic capacity of suckling pups is proposed. PMID:23417844

  17. Method of dissolving metal oxides with di- or polyphosphonic acid and a redundant

    DOEpatents

    Horwitz, Earl P.; Chiarizia, Renato

    1996-01-01

    A method of dissolving metal oxides using a mixture of a di- or polyphosphonic acid and a reductant wherein each is present in a sufficient amount to provide a synergistic effect with respect to the dissolution of metal oxides and optionally containing corrosion inhibitors and pH adjusting agents.

  18. Graphene oxide as an acid catalyst for the room temperature ring opening of epoxides.

    PubMed

    Dhakshinamoorthy, Amarajothi; Alvaro, Mercedes; Concepción, Patricia; Fornés, Vicente; Garcia, Hermenegildo

    2012-06-01

    The minute amount of hydrogen sulfate groups introduced into the graphene oxide (GO) obtained by Hummers oxidation of graphite renders this material as a highly efficient, recyclable acid catalyst for the ring opening of epoxides with methanol and other primary alcohols as nucleophile and solvent. PMID:22534622

  19. SALICYLIC ACID- AND NITRIC OXIDE-MEDIATED SIGNAL TRANSDUCTION IN DISEASE RESISTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current advances in plant defense signaling is discussed, with emphasis on the role of nitric oxide and salicylic acid in the development of disease resistance. Nitric Oxide has recently been shown to have an important role in plant disease resistance. We show an increase in NOS-like activity in TMV...

  20. Augmenting antifungal activity of oxidizing agent with kojic acid: Control of Penicillium strains infecting crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative treatment is a strategy for preventing Penicillium contamination in foods or crops. Antifungal efficacy of oxidant [hydrogen peroxide (H2O2)], biotic effector [kojic acid (KA)] and abiotic stress (heat), alone or in combination, was investigated in Penicillium. The levels of antifungal int...

  1. Oxidative decarboxylation of free and peptide-linked amino acids in phagocytizing guinea pig granulocytes.

    PubMed Central

    Adeniyi-Jones, S K; Karnovsky, M L

    1981-01-01

    The oxidative decarboxylation of amino acids by a system consisting of myeloperoxidase-hydrogen peroxide-chloride has been demonstrated previously by others and the process has been considered to be part of the microbicidal armamentarium of some phagocytic leukocytes. We were able to translate these earlier observations, made on model systems, to intact guinea pig granulocytes. We could demonstrate differences in the cellular handling of peptide-linked amino acids as particles, compared with free amino acids. Specific inhibitors were used to explore two routes of oxidative decarboxylation: (a) the myeloperoxidase-catalyzed direct decarboxylation-deamination reaction, and (b) oxidation of alpha-keto acids after transamination of amino acids. These inhibitors were cyanide, azide, and tapazole for the former pathway, and amino-oxyacetate for the latter. Amino-oxyacetate profoundly inhibited the decarboxylation of free 14C-amino acids (alanine and aspartate) in both resting and stimulated cells, but had only a minimal effect on 14CO2 production from ingested insoluble 14C-protein. On the other hand, the peroxidase inhibitors cyanide, azide, and tapazole dramatically inhibited the production of 14CO2 from ingested particulate 14C-protein, but had only small effects on the decarboxylation of free amino acid. Soluble, uniformly labeled 14C-protein was not significantly converted to 14CO2 even in the presence of phagocytizable polystyrene beads. These observation suggest that the amino acids taken up by phagocytosis (e.g., as denatured protein particles) are oxidatively decarboxylated and deaminated in the phagosomes by the myeloperoxidase-hydrogen peroxide-chloride system; soluble free amino acids that enter the cytoplasm by diffusion or transport are oxidatively decarboxylated after transamination by the normal cellular amino acid oxidative pathway. PMID:6267101

  2. Carboxymethyl chitosan-mediated synthesis of hyaluronic acid-targeted graphene oxide for cancer drug delivery.

    PubMed

    Yang, Huihui; Bremner, David H; Tao, Lei; Li, Heyu; Hu, Juan; Zhu, Limin

    2016-01-01

    In order to enhance the efficiency and specificity of anticancer drug delivery and realize intelligently controlled release, a new drug carrier was developed. Graphene oxide (GO) was first modified with carboxymethyl chitosan (CMC), followed by conjugation of hyaluronic acid (HA) and fluorescein isothiocyanate (FI). The resulting GO-CMC-FI-HA conjugate was characterized and used as a carrier to encapsulate the anticancer drug doxorubicin (DOX) to study in vitro release behavior. The drug loading capacity is as high as 95% and the drug release rate under tumor cell microenvironment of pH 5.8 is significantly higher than that under physiological conditions of pH 7.4. Cell uptake studies show that the GO-CMC-FI-HA/DOX complex can specifically target cancer cells, which are over-expressing CD44 receptors and effectively inhibit their growth. The above results suggest that the functionalized graphene-based material has potential applications for targeted delivery and controlled release of anticancer drugs. PMID:26453853

  3. Effect of aniline on cadmium adsorption by sulfanilic acid-grafted magnetic graphene oxide sheets.

    PubMed

    Hu, Xin-jiang; Liu, Yun-guo; Zeng, Guang-ming; Wang, Hui; Hu, Xi; Chen, An-wei; Wang, Ya-qin; Guo, Yi-Mming; Li, Ting-ting; Zhou, Lu; Liu, Shao-heng; Zeng, Xiao-xia

    2014-07-15

    Cd(II) has posed severe health risks worldwide. To remove this contaminant from aqueous solution, the sulfanilic acid-grafted magnetic graphene oxide sheets (MGOs/SA) were prepared and characterized. The mutual effects of Cd(II) and aniline adsorption on MGOs/SA were studied. The effects of operating parameters such as pH, ionic strength, contact time and temperature on the Cd(II) enrichment, as well as the adsorption kinetics and isotherm were also investigated. The results demonstrated that MGOs/SA could effectively remove Cd(II) and aniline from the aqueous solution and the two adsorption processes were strongly dependent on solution pH. The Cd(II) adsorption was reduced by the presence of aniline at pH<5.4 but was improved at pH>5.4. The presence of Cd(II) diminished the adsorption capacity for aniline at pH<7.8 but enhanced the aniline adsorption at pH>7.8. The decontamination of Cd(II) by MGOs/SA was influenced by ionic strength. Besides, the adsorption process could be well described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that the intraparticle diffusion was not the only rate-limiting step for the adsorption process. Moreover, the experimental data of isotherm followed the Freundlich isotherm model. PMID:24863786

  4. Mechanically stable thermally crosslinked poly(acrylic acid)/reduced graphene oxide aerogels.

    PubMed

    Ha, Heonjoo; Shanmuganathan, Kadhiravan; Ellison, Christopher J

    2015-03-25

    Graphene oxide (GO) aerogels, high porosity (>99%) low density (∼3-10 mg cm(-3)) porous materials with GO pore walls, are particularly attractive due to their lightweight, high surface area, and potential use in environmental remediation, superhydrophobic and superoleophilic materials, energy storage, etc. However, pure GO aerogels are generally weak and delicate which complicates their handling and potentially limits their commercial implementation. The focus of this work was to synthesize highly elastic, mechanically stable aerogels that are robust and easy to handle without substantially sacrificing their high porosity or low density. To overcome this challenge, a small amount of readily available and thermally cross-linkable poly(acrylic acid) (PAA) was intermixed with GO to enhance the mechanical integrity of the aerogel without disrupting other desirable characteristic properties. This method is a simple straightforward procedure that does not include multistep or complicated chemical reactions, and it produces aerogels with mass densities of about 4-6 mg cm(-3) and >99.6% porosity that can reversibly support up to 10,000 times their weight with full recovery of their original volume. Finally, pressure sensing capabilities were demonstrated and their oil absorption capacities were measured to be around 120 g oil per g aerogel(-1) which highlights their potential use in practical applications. PMID:25714662

  5. Benzoic Acid Interactions Affect Aquatic Properties and Toxicity of Copper Oxide Nanoparticles.

    PubMed

    Wang, Zhuang; Fang, Hao; Wang, Se

    2016-08-01

    Effects of benzoic acid (BA) on physicochemical properties and ecotoxicities of CuO nanoparticles (CuONPs) in model aqueous media were studied. The CuONPs had larger hydrodynamic sizes and higher surface zeta potentials during 96 h of settling in the presence of BA than when the BA were not present. BA interaction with CuONPs is shown to promote dissolved Cu release from CuONPs in a dose-dependent manner. The contribution of free Cu(2+)-ions to growth inhibition toxicity of the CuONP suspensions at a toxicologically relevant concentration for the green alga Scenedesmus obliquus was around 22 %, indicating that dissolved fraction was not the major source of toxicity of CuONPs. The toxicity of CuONPs increased as the BA concentration increased. BA significantly altered total antioxidant capacity of CuONPs-exposed algal cells. The mechanism of the BA effect on the CuONPs toxicity may be mainly associated with degree of agglomeration, dissolved Cu, and particle-induced oxidative stress. PMID:27098254

  6. Enhancing hepatic mitochondrial fatty acid oxidation stimulates eating in food-deprived mice

    PubMed Central

    Mansouri, Abdelhak; Pacheco-López, Gustavo; Ramachandran, Deepti; Arnold, Myrtha; Leitner, Claudia; Prip-Buus, Carina; Langhans, Wolfgang

    2014-01-01

    Hepatic fatty acid oxidation (FAO) has long been implicated in the control of eating. Nevertheless, direct evidence for a causal relationship between changes in hepatic FAO and changes in food intake is still missing. Here we tested whether increasing hepatic FAO via adenovirus-mediated expression of a mutated form of the key regulatory enzyme of mitochondrial FAO carnitine palmitoyltransferase 1A (CPT1mt), which is active but insensitive to inhibition by malonyl-CoA, affects eating and metabolism in mice. CPT1mt expression increased hepatocellular CPT1 protein levels. This resulted in an increase in circulating ketone body levels in fasted CPT1mt-expressing mice, suggesting an increase in hepatic FAO. These mice did not show any significant changes in cumulative food intake, energy expenditure, or respiratory quotient after 4-h food deprivation. After 24-h food deprivation, however, the CPT1mt-expressing mice displayed increased food intake. Thus expression of CPT1mt in the liver increases hepatic FAO capacity, but does not inhibit eating. Rather, it may even stimulate eating after prolonged food deprivation. These data do not support the hypothesis that an increase in hepatic FAO decreases food intake. PMID:25427767

  7. Associations between daily mortality in London and combined oxidant capacity, ozone and nitrogen dioxide.

    PubMed

    Williams, M L; Atkinson, R W; Anderson, H R; Kelly, F J

    2014-01-01

    Both nitrogen dioxide (NO2) and ozone (O3) are powerful oxidants in ambient air that are intimately linked through atmospheric chemistry and which continuously interchange over very short timescales. Based upon atmospheric chemistry alone, there is a strong, a priori, reason for considering O3 and NO2 together in epidemiological studies, rather than either of the two pollutants separately in single-pollutant models. This paper compares two approaches to this, using Ox, defined as O3 + NO2, as a single metric and also using O3 and NO2 together in two-pollutant models. We hypothesised that the magnitude of the association between Ox and daily mortality would be greater than for NO2 and O3 individually. Using collocated hourly measurements for O3 and NO2 in London, from 2000 to 2005, we carried out a time series analysis of daily mortality. We investigated O3, NO2 and Ox individually in single-pollutant Poisson regression models and NO2 and O3 jointly in two-pollutant models in both all-year and season-specific analyses. We observed larger associations for mean 24-h concentrations of Ox (1.30 % increase in mortality per 10 ppb) than for O3 (0.87 %) and NO2 (0 %) individually. However, when analysed jointly in two-pollutant models, associations for O3 (1.54 %) and NO2 (1.07 %) were comparable to the Ox association. Season-specific analyses broadly followed this pattern irrespective of whether the Ox concentrations were driven by O3 production (summer) or depletion (winter). This novel approach in air pollution epidemiology captures the simultaneous impact of both oxidants whilst avoiding many of the statistical issues associated with two-pollutant models and potentially simplifies health impact calculations. PMID:25431629

  8. The Capacity of Red Blood Cells to Reduce Nitrite Determines Nitric Oxide Generation under Hypoxic Conditions

    PubMed Central

    Fens, Marcel H.; Larkin, Sandra K.; Oronsky, Bryan; Scicinski, Jan; Morris, Claudia R.; Kuypers, Frans A.

    2014-01-01

    Nitric oxide (NO) is a key regulator of vascular tone. Endothelial nitric oxide synthase (eNOS) is responsible for NO generation under normoxic conditions. Under hypoxia however, eNOS is inactive and red blood cells (RBC) provide an alternative NO generation pathway from nitrite to regulate hypoxic vasodilation. While nitrite reductase activity of hemoglobin is well acknowledged, little is known about generation of NO by intact RBC with physiological hemoglobin concentrations. We aimed to develop and apply a new approach to provide insights in the ability of RBC to convert nitrite into NO under hypoxic conditions. We established a novel experimental setup to evaluate nitrite uptake and the release of NO from RBC into the gas-phase under different conditions. NO measurements were similar to well-established clinical measurements of exhaled NO. Nitrite uptake was rapid, and after an initial lag phase NO release from RBC was constant in time under hypoxic conditions. The presence of oxygen greatly reduced NO release, whereas inhibition of eNOS and xanthine oxidoreductase (XOR) did not affect NO release. A decreased pH increased NO release under hypoxic conditions. Hypothermia lowered NO release, while hyperthermia increased NO release. Whereas fetal hemoglobin did not alter NO release compared to adult hemoglobin, sickle RBC showed an increased ability to release NO. Under all conditions nitrite uptake by RBC was similar. This study shows that nitrite uptake into RBC is rapid and release of NO into the gas-phase continues for prolonged periods of time under hypoxic conditions. Changes in the RBC environment such as pH, temperature or hemoglobin type, affect NO release. PMID:25007272

  9. PGC1α Expression Defines a Subset of Human Melanoma Tumors with Increased Mitochondrial Capacity and Resistance to Oxidative Stress

    PubMed Central

    Vazquez, Francisca; Lim, Ji-Hong; Chim, Helen; Bhalla, Kavita; Girnun, Geoff; Pierce, Kerry; Clish, Clary B.; Granter, Scott R.; Widlund, Hans R.; Spiegelman, Bruce M.; Puigserver, Pere

    2013-01-01

    SUMMARY Cancer cells reprogram their metabolism using different strategies to meet energy and anabolic demands to maintain growth and survival. Understanding the molecular and genetic determinants of these metabolic programs is critical to successfully exploit them for therapy. Here, we report that the oncogenic melanocyte lineage-specification transcription factor MITF drives PGC1α (PPARGC1A) overexpression in a subset of human melanomas and derived cell lines. Functionally, PGC1α positive melanoma cells exhibit increased mitochondrial energy metabolism and ROS detoxification capacities that enables survival under oxidative stress conditions. Conversely, PGC1α negative melanoma cells are more glycolytic and sensitive to ROS-inducing drugs. These results demonstrate that differences in PGC1α levels in melanoma tumors have a profound impact in their metabolism, biology and drug sensitivity. PMID:23416000

  10. FABP4 reversed the regulation of leptin on mitochondrial fatty acid oxidation in mice adipocytes

    PubMed Central

    Gan, Lu; Liu, Zhenjiang; Cao, Weina; Zhang, Zhenzhen; Sun, Chao

    2015-01-01

    Fatty acid binding protein 4 (FABP4), plays key role in fatty acid transportation and oxidation, and increases with leptin synergistically during adipose inflammation process. However, the regulation mechanism between FABP4 and leptin on mitochondrial fatty acid oxidation remains unclear. In this study, we found that FABP4 reduced the expression of leptin, CPT-1 and AOX1 in mice adipocytes. Conversely, FABP4 was down-regulated in a time-dependent manner by leptin treatment. Additionally, forced expression of FABP4 attenuated the expression of PGC1-α, UCP2, CPT-1, AOX1 and COX2 compared with leptin incubation. Moreover, mitochondrial membrane potential, fatty acid oxidation enzyme medium-chain acyl-CoA dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD) and Cyt C levels were reduced in response to the overexpression of FABP4. These reductions correspond well with the reduced release of free fatty acid and the inactivation of mitochondrial complexes I and III by FABP4 overexpression. Furthermore, addition of the Akt/mTOR pathway-specific inhibitor (MK2206) blocked the mitochondrial fatty acid oxidation and respiration factors, whereas interference of FABP4 overcame these effects. Taken together, FABP4 could reverse the activation of the leptin-induced mitochondrial fatty acid oxidation, and the inhibition of Akt/mTOR signal pathway played a key role in this process. PMID:26310911

  11. Stereoselective and nonstereoselective effects of ibuprofen enantiomers on mitochondrial beta-oxidation of fatty acids

    SciTech Connect

    Freneaux, E.; Fromenty, B.; Berson, A.; Labbe, G.; Degott, C.; Letteron, P.; Larrey, D.; Pessayre, D. , Hopital Beaujon, Clichy )

    1990-11-01

    The effects of the R-(-) and S-(+)ibuprofen enantiomers were first studied in vitro with mouse liver mitochondria incubated in the presence of various concentrations of exogenous coenzyme A. In the presence of a low concentration of coenzyme A (2.5 microM), the R-(-)enantiomer (which forms an acylcoenzyme A) inhibited stereoselectively the beta oxidation of (1-{sup 14}C)palmitic acid but not that of (1-{sup 14}C)palmitoyl-L-carnitine (which can directly enter the mitochondria). In the presence, however, of a concentration of coenzyme A (50 microM) reproducing that present in liver cell cytosol, both enantiomers (2 mM) slightly inhibited the beta oxidation of (1-{sup 14}C)palmitic acid and markedly inhibited the beta oxidation of (1-{sup 14}C)octanoic acid and (1-{sup 14}C)butyric acid. In vivo, both enantiomers (1 mmol.kg-1) similarly inhibited the formation of ({sup 14}C)CO{sub 2} from (1-{sup 14}C)fatty acids. Both enantiomers similarly decreased plasma ketone bodies. Both similarly increased hepatic triglycerides, and both produced mild microvesicular steatosis of the liver. We conclude that both ibuprofen enantiomers inhibit beta oxidation of fatty acids in vitro and in vivo. In addition, the R-(-)enantiomer may stereoselectively sequester coenzyme A; at low concentrations of coenzyme A in vitro, this may stereoselectively inhibit the mitochondrial uptake and beta oxidation of long chain fatty acids.

  12. Factors affecting acid neutralizing capacity in the Adirondack region of New York: a solute mass balance approach.

    PubMed

    Ito, Mari; Mitchell, Myron J; Driscoll, Charles T; Roy, Karen M

    2005-06-01

    High rates of acidic deposition in the Adirondack region of New York have accelerated acidification of soils and surface waters. Annual input-output budgets for major solutes and acid-neutralizing capacity (ANC) were estimated for 43 drainage lake-watersheds in the Adirondacks from 1998 to 2000. Sulfate was the predominant anion on an equivalent basis in both precipitation and drainage export. Calcium ion had the largest cation drainage export, followed by Mg2+. While these watersheds showed net nitrogen (N) retention, the drainage losses of SO4(2-), Cl-, base cations, and ANC exceeded their respective inputs from precipitation. Land cover (forest type and wetlands) affected the export of SO4(2-), N solutes, and dissolved organic carbon (DOC). The relationships of solute export with elevation (negative for base cations and Cl-, positive for NO3- and H+) suggest the importance of the concomitant changes of biotic and abiotic watershed characteristics associated with elevational gradients. The surface water ANC increased with the sum of base cations and was greatest in the lakes with watersheds characterized by thick deposits of glacial till. The surface water ANC was also higher in the lake-watersheds with lower DOC export. Some variation in lake ANC was associated with variability in acidic deposition. Using a classification system previously developed for Adirondack lakes on the basis primarily of surficial geology, lake-watersheds were grouped into five classes. The calculated ANC fluxes based on the major sinks and sources of ANC were comparable with measured ANC for the thick-till (I) and the medium-till lake-watersheds with low DOC (II). The calculated ANC was overestimated for the medium-till with high DOC (III) and the thin-till with high DOC (V) lake-watersheds, suggesting the importance of naturally occurring organic acids as an ANC sink, which was not included in the calculations. The lower calculated estimates than the measured ANC for the thin-till lake