Science.gov

Sample records for acid oxidation treatment

  1. 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 ...

  2. Oxidative acid treatment and characterization of new biocarbon from sustainable Miscanthus biomass.

    PubMed

    Anstey, Andrew; Vivekanandhan, Singaravelu; Rodriguez-Uribe, Arturo; Misra, Manjusri; Mohanty, Amar Kumar

    2016-04-15

    Oxidative acid treatments of biochar produced from Miscanthus were performed in this study using nitric acid, sulfuric acid, and a mixture of both. The structural and morphological changes of the acid-treated biochar were investigated using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Raman spectroscopy, organic elemental analysis and energy-dispersive X-ray spectroscopy (EDS). Improved surface functionality of the treated biochars was observed in their respective FT-IR spectra through the presence of nitro and carboxylic acid functional groups. SEM-EDS and elemental analysis revealed a large increase in the oxygen to carbon ratio in the biochar, which was evidence of chemical oxidation from the acid treatment. Further, TGA study showed the reduced thermal stability of acid-treated biochar over 200°C due to the increased oxygen content. Acid treatments also influenced the graphitic structure of the biochar, as observed in the Raman spectra. The results suggest that biochar can be successfully functionalized for composite applications and provide a sustainable alternative to petroleum-based carbon additives.

  3. A photoelectron spectroscopy study on the indium tin oxide treatment by acids and bases

    NASA Astrophysics Data System (ADS)

    Nüesch, F.; Rothberg, L. J.; Forsythe, E. W.; Le, Quoc Toan; Gao, Yongli

    1999-02-01

    We report on the chemical adsorption of acids and bases on indium tin oxide (ITO). Ultraviolet photoelectron spectroscopy was used to measure the work function of the treated ITO and atomic surface concentrations were determined by x-ray photoelectron spectroscopy. The acid treatments yield work-function shifts as high as 0.7 eV compared to the nontreated ITO. Huge shifts in the work function are also obtained for the treatments with bases and are opposite to those obtained with the acids. These dramatic shifts are indicative of a double ionic surface layer. The importance of an appropriate plasma treatment prior to the chemical adsorption of acids or bases is discussed in terms of surface acido-basicity.

  4. Apelin Treatment Increases Complete Fatty Acid Oxidation, Mitochondrial Oxidative Capacity, and Biogenesis in Muscle of Insulin-Resistant Mice

    PubMed Central

    Attané, Camille; Foussal, Camille; Le Gonidec, Sophie; Benani, Alexandre; Daviaud, Danièle; Wanecq, Estelle; Guzmán-Ruiz, Rocío; Dray, Cédric; Bezaire, Veronic; Rancoule, Chloé; Kuba, Keiji; Ruiz-Gayo, Mariano; Levade, Thierry; Penninger, Josef; Burcelin, Rémy; Pénicaud, Luc; Valet, Philippe; Castan-Laurell, Isabelle

    2012-01-01

    Both acute and chronic apelin treatment have been shown to improve insulin sensitivity in mice. However, the effects of apelin on fatty acid oxidation (FAO) during obesity-related insulin resistance have not yet been addressed. Thus, the aim of the current study was to determine the impact of chronic treatment on lipid use, especially in skeletal muscles. High-fat diet (HFD)-induced obese and insulin-resistant mice treated by an apelin injection (0.1 μmol/kg/day i.p.) during 4 weeks had decreased fat mass, glycemia, and plasma levels of triglycerides and were protected from hyperinsulinemia compared with HFD PBS-treated mice. Indirect calorimetry experiments showed that apelin-treated mice had a better use of lipids. The complete FAO, the oxidative capacity, and mitochondrial biogenesis were increased in soleus of apelin-treated mice. The action of apelin was AMP-activated protein kinase (AMPK) dependent since all the effects studied were abrogated in HFD apelin-treated mice with muscle-specific inactive AMPK. Finally, the apelin-stimulated improvement of oxidative capacity led to decreased levels of acylcarnitines and enhanced insulin-stimulated glucose uptake in soleus. Thus, by promoting complete lipid use in muscle of insulin-resistant mice through mitochondrial biogenesis and tighter matching between FAO and the tricarboxylic acid cycle, apelin treatment could contribute to insulin sensitivity improvement. PMID:22210322

  5. Mixed Acid Oxidation

    SciTech Connect

    Pierce, R.A.

    1999-10-26

    Several non-thermal processes have been developed to destroy organic waste compounds using chemicals with high oxidation potentials. These efforts have focused on developing technologies that work at low temperatures, relative to incineration, to overcome many of the regulatory issues associated with obtaining permits for waste incinerators. One such technique with great flexibility is mixed acid oxidation. Mixed acid oxidation, developed at the Savannah River Site, uses a mixture of an oxidant (nitric acid) and a carrier acid (phosphoric acid). The carrier acid acts as a non-volatile holding medium for the somewhat volatile oxidant. The combination of acids allows appreciable amounts of the concentrated oxidant to remain in the carrier acid well above the oxidant''s normal boiling point.

  6. Effects on temperature and acidic pre-treatment on Fenton-driven oxidation of MTBE-spent granular activated carbon

    EPA Science Inventory

    Temperature-dependent mechanisms in the Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was investigated. Prior to iron (Fe) amendment to the GAC, acid-treatment altered the surface chemistry of the GAC and lowered the p...

  7. Effects of Temperature and Acidic Pre-Treatment on Fenton-Driven Oxidation of MTBE-Spent Granular Activated Carbon

    EPA Science Inventory

    Temperature-dependent mechanisms in the Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was investigated. Prior to iron (Fe) amendment to the GAC, acid-treatment altered the surface chemistry of the GAC and lowered the pH ...

  8. Influence of pH-control in phosphoric acid treatment of titanium oxide and their powder properties

    SciTech Connect

    Onoda, Hiroaki Matsukura, Aki

    2015-06-15

    Highlights: • The photocatalytic activity was suppressed by phosphoric acid treatment. • The obtained pigment had small particles with sub-micrometer size. • By phosphoric acid treatment, the smoothness of samples improved. - Abstract: Titanium oxide that has the photocatalytic activity is used as a white pigment for cosmetics. A certain degree of sebum on the skin is decomposed by the ultraviolet radiation in sunlight. In this work, titanium oxide was shaken with phosphoric acid at various pH to synthesize a novel white pigment for cosmetics. Their chemical composition, powder properties, photocatalytic activity, color phase, and smoothness were studied. The obtained materials indicated XRD peaks of titanium oxide, however, these peak intensity became weak by phosphoric acid treatment. These samples without heating and heated at 100 °C included the small particles with sub-micrometer size. The photocatalytic activity of the obtained powders became weak by phosphoric acid treatment at pH 4 and 5 to protect the sebum on the skin.

  9. Population dynamics of iron-oxidizing communities in pilot plants for the treatment of acid mine waters

    SciTech Connect

    Elke Heinzel; Eberhard Janneck; Franz Glombitza; Michael Schlmann; Jana Seifert

    2009-08-15

    The iron-oxidizing microbial community in two pilot plants for the treatment of acid mine water was monitored to investigate the influence of different process parameters such as pH, iron concentration, and retention time on the stability of the system to evaluate the applicability of this treatment technology on an industrial scale. The dynamics of the microbial populations were followed using T-RFLP (terminal restriction fragment length polymorphism) over a period of several months. For a more precise quantification, two TaqMan assays specific for the two prominent groups were developed and the relative abundance of these taxa in the iron-oxidizing community was verified by real-time PCR. The investigations revealed that the iron-oxidizing community was clearly dominated by two groups of Betaproteobacteria affiliated with the poorly known and not yet recognized species 'Ferrovum myxofaciens' and with strains related to Gallionella ferruginea, respectively. These taxa dominated the microbial community during the whole investigation period and accelerated the oxidation of ferrous iron despite the changing characteristics of mine waters flowing into the plants. Thus, it is assumed that the treatment technology can also be applied to other mine sites and that these organisms play a crucial role in such treatment systems. 32 refs., 4 figs. 1 tab.

  10. Fatty acid-induced mitochondrial uncoupling in adipocytes is not a promising target for treatment of insulin resistance unless adipocyte oxidative capacity is increased.

    PubMed

    Frayn, K N; Langin, D; Karpe, F

    2008-03-01

    The release of fatty acids from white adipose tissue is regulated at several levels. We have examined the suggestion that fatty acid release might be diminished by upregulation of mitochondrial fatty acid oxidation in the adipocyte, through increasing mitochondrial uncoupling. The intrinsic oxidative capacity of white adipose tissue is low, and older studies suggest that there is little fatty acid oxidation in white adipocytes, human or rodent. We have examined data on fatty acid metabolism and O(2) consumption in human white adipose tissue in vivo, and conclude that increasing fatty acid oxidation within the oxidative capacity of the tissue would produce only small changes (a few percent) in fatty acid release. The major locus of control of fatty acid release beyond the stimulation of lipolysis is the pathway of fatty acid esterification, already probably targeted by the thiazolidinedione insulin-sensitising agents. An alternative approach would be to upregulate the mitochondrial capacity of the adipocyte. We review proof-of-concept studies in which the phenotype of the white adipocyte has been changed to resemble that of the brown adipocyte by expression of peroxisome proliferator-activated receptor coactivator-1alpha. This increases oxidative capacity and also leads to fatty acid retention through upregulation of glycerol-3-phosphate production, and hence increased fatty acid re-esterification. We conclude that prevention or treatment of insulin resistance through alteration of adipocyte fatty acid handling will require more than a simple alteration of the activity of mitochondrial beta-oxidation within normal limits.

  11. Study on Treatment of acidic and highly concentrated fluoride waste water using calcium oxide-calcium chloride

    NASA Astrophysics Data System (ADS)

    Ren, T.; Gao, X. R.; Zheng, T.; Wang, P.

    2016-08-01

    There are problems with treating acidic waste water containing high concentration fluorine by chemical precipitation, including the low sludge setting velocity and the high difficulty of reaching the criterion. In Heilongjiang province, a graphite factory producing high-purity graphite generates acidic waste water with a high concentration of fluorine. In this paper, the effect of removals on the concentration of fluoride with the combined treatment of calcium oxide and calcium chloride were discussed with regard to acid waste water. The study improved the sludge characteristics by using polyacrylamide (PAM) and polymeric aluminum chloride (PAC). The effect of different coagulants on sludge was evaluated by the sludge settlement ratio (SV), sludge volume index (SVI) and sludge moisture content. The results showed that the optimal combination for 100 ml waste water was calcium oxide addition amount of 14 g, a calcium chloride addition amount of 2.5 g, a PAM addition amount of 350 mg/L, and the effluent fluoride concentration was below 6 mg/L. PAM significantly improved the sludge settling velocity. The sludge settlement ratio reduced from 87.6% to 60%. The process for wastewater treatment was easily operated and involved low expenditure.

  12. Fatty acids oxidation and alternative energy sources detected in Taenia crassiceps cysticerci after host treatment with antihelminthic drugs.

    PubMed

    Fraga, Carolina Miguel; Costa, Tatiane Luiza; Bezerra, José Clecildo Barreto; de Souza Lino Junior, Ruy; Vinaud, Marina Clare

    2012-05-01

    Human cysticercosis caused by Taenia crassiceps is rare however it is considered of zoonotic risk. The treatment of the infected patients was successful when using albendazole or praziquantel. The active forms of albendazole inhibit the glucose uptake and the active forms of praziquantel alter glycogen levels and nutrients absorption. The aim of this study was to analyze the production of organic acids that indicate the oxidation of fatty acids and the use of alternative energy sources from T. crassiceps cysticerci removed from the peritoneal cavity of mice treated with low dosages of albendazole (5.75 and 11.5mg/kg) or praziquantel (3.83 and 7.67 mg/kg). The beta-hydroxibutyrate production was higher by the larval stage cysticerci in all treated groups and the propionate production was higher in final stage cysticerci treated with 11.5mg/kg of albendazole when compared to the control group. The larval stages of cysticerci from the groups treated with 5.75 mg/kg of albendazole and 3.83 mg/kg of praziquantel produced more urea than the initial and final stages which indicate amino acids breakdown. We conclude that it was possible to detect the fatty acid oxidation and amino acids breakdown which indicate the use of alternative energy production sources as the used dosages only cause a partial blockage of the glucose uptake and leads to metabolic alterations in the cysticerci. The metabolic behavior observed after host treatment was different from former descriptions of the in vitro one which indicates great host-parasite interaction.

  13. The influence of treatment temperature on the acidity of MWCNT oxidized by HNO 3 or a mixture of HNO 3/H 2SO 4

    NASA Astrophysics Data System (ADS)

    Saleh, Tawfik A.

    2011-06-01

    The nature of multi-walled carbon nanotubes (MWCNTs) varies with the change in oxidation conditions. In this work, the effect of treatment temperatures on the acidity of MWCNTs was studied. Oxidation was performed by refluxing the MWCNTs in nitric acid or mixtures of sulfuric acid and nitric acid at different temperatures. After oxidative treatment, a quantitative characterization of o-MWCNTs has been performed using acid-base titrations which show that the number of surface acidic functional groups increased by increasing the treatment temperatures. Energy dispersive X-ray (EDX) measurements show that the oxygen content increased with increasing treatment temperatures. Fourier transform infrared absorption spectroscopy (FTIR) was used for qualitative characterization. It has been demonstrated that the acidity is a function of the type of oxidizing agent used and the treatment temperatures. Due to the importance in attachment strategies and functionalization, this study adds to the global discussion of the possibility of controlling the MWCNTs' surface chemistry which plays a crucial role in determining its reactivity.

  14. Nickel inhibits mitochondrial fatty acid oxidation.

    PubMed

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

    2015-08-01

    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 h), 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.

  15. ASCORBIC ACID TREATMENT TO REDUCE RESIDUAL HALOGEN-BASED OXIDANTS PRIOR TO THE DETERMINATION OF HALOGENATED DISINFECTION BYPRODUCTS IN POTABLE WATER

    EPA Science Inventory

    Treatment of potable water samples with ascorbic acid has been investigated as a means for reducing residual halogen-based oxidants (disinfectants)i.e., HOCl, Cl2, Brw and BrCl, prior to determination of EPA Method 551.1A and 551.1B analytes. These disinfection byproducts include...

  16. 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

  17. Effect of neutralized solid waste generated in lime neutralization on the ferrous ion bio-oxidation process during acid mine drainage treatment.

    PubMed

    Liu, Fenwu; Zhou, Jun; Zhou, Lixiang; Zhang, Shasha; Liu, Lanlan; Wang, Ming

    2015-12-15

    Bio-oxidation of ferrous ions prior to lime neutralization exhibits great potential for acid mine drainage (AMD) treatment, while slow ferrous ion bio-oxidation or total iron precipitation is a bottleneck in this process. In this study, neutralized solid waste (NSW) harvested in an AMD lime neutralization procedure was added as a crystal seed in AMD for iron oxyhydroxysulfate bio-synthesis. The effect of this waste on ferrous ion oxidation efficiency, total iron precipitation efficiency, and iron oxyhydroxysulfate minerals yield during ferrous ion bio-oxidation by Acidithiobacillus ferrooxidans was investigated. Ferrous ion oxidation efficiency was greatly improved by adding NSW. After 72 h incubation, total iron precipitation efficiency in treatment with 24 g/L of NSW was 1.74-1.03 times higher than in treatment with 0-12 g/L of NSW. Compared with the conventional treatment system without added NSW, the iron oxyhydroxysulfate minerals yield was increased by approximately 21.2-80.9% when 3-24 g/L of NSW were added. Aside from NSW, jarosite and schwertmannite were the main precipitates during ferrous ion bio-oxidation with NSW addition. NSW can thus serve as the crystal seed for iron oxyhydroxysulfate mineral bio-synthesis in AMD, and improve ferrous ion oxidation and total iron precipitation efficiency significantly.

  18. Influence of wastewater sludge treatment using combined peroxyacetic acid oxidation and inorganic coagulants re-flocculation on characteristics of extracellular polymeric substances (EPS).

    PubMed

    Zhang, Weijun; Cao, Bingdi; Wang, Dongsheng; Ma, Teng; Xia, Hua; Yu, Dehong

    2016-01-01

    Extracellular polymeric substances (EPS) are highly hydrated biopolymers and play important roles in bioflocculation, floc stability, and solid-water separation processes. Destroying EPS structure will result in sludge reduction and release of trapped water. In this study, the effects of combined process of peracetic acid (PAA) pre-oxidation and chemical re-flocculation on morphological properties and distribution and composition of EPS of the resultant sludge flocs were investigated in detail to gain insights into the mechanism involved in sludge treatment. It was found that sludge particles were effectively solubilized and protein-like substances were degraded into small molecules after PAA oxidation. A higher degradation of protein-like substances was observed at acid environments under PAA oxidation. Microscopic analysis revealed that no integral sludge floc was observed after oxidation with PAA at high doses. The floc was reconstructed with addition of inorganic coagulants (polyaluminium chloride (PACl) and ferric chloride (FeCl3)) and PACl performed better in flocculation due to its higher charge neutralization and bridging ability. Combined oxidative lysis and chemical re-flocculation provide a novel solution for sludge treatment.

  19. Influence of wastewater sludge treatment using combined peroxyacetic acid oxidation and inorganic coagulants re-flocculation on characteristics of extracellular polymeric substances (EPS).

    PubMed

    Zhang, Weijun; Cao, Bingdi; Wang, Dongsheng; Ma, Teng; Xia, Hua; Yu, Dehong

    2016-01-01

    Extracellular polymeric substances (EPS) are highly hydrated biopolymers and play important roles in bioflocculation, floc stability, and solid-water separation processes. Destroying EPS structure will result in sludge reduction and release of trapped water. In this study, the effects of combined process of peracetic acid (PAA) pre-oxidation and chemical re-flocculation on morphological properties and distribution and composition of EPS of the resultant sludge flocs were investigated in detail to gain insights into the mechanism involved in sludge treatment. It was found that sludge particles were effectively solubilized and protein-like substances were degraded into small molecules after PAA oxidation. A higher degradation of protein-like substances was observed at acid environments under PAA oxidation. Microscopic analysis revealed that no integral sludge floc was observed after oxidation with PAA at high doses. The floc was reconstructed with addition of inorganic coagulants (polyaluminium chloride (PACl) and ferric chloride (FeCl3)) and PACl performed better in flocculation due to its higher charge neutralization and bridging ability. Combined oxidative lysis and chemical re-flocculation provide a novel solution for sludge treatment. PMID:26584344

  20. Wet oxidation of salicylic acid solutions.

    PubMed

    Collado, Sergio; Garrido, Laura; Laca, Adriana; Diaz, Mario

    2010-11-15

    Salicylic acid is a frequent pollutant in several industrial wastewaters. Uncatalyzed wet air oxidation, which is a promising technique for the treatment of phenolic effluents, has not been analyzed yet for the removal of salicylic acid. The effect of different conditions of pH (1.3-12.3), pressure (1.0-4.1 MPa), temperature (413-443 K), and initial concentrations (1.45-14.50 mM) on the wet oxidation of salicylate/salicylic acid solutions have here been investigated. The pH value of the reaction media was found to be a key parameter for the rate of the oxidation process with an optimum at pH 3.1, when the concentrations of salicylic acid and salicylate were similar. The oxidation reaction followed pseudofirst-order kinetics with respect to salicylic acid and 0.82 order with respect to dissolved oxygen. Additionally, the evolution of the color during the wet oxidation was analyzed and discussed in relation with the formation of intermediate compounds. Then, a reaction pathway for the noncatalytic wet oxidation of the salicylic acid was proposed.

  1. Long-Term Effects of Irbesartan Treatment and Smoking on Nucleic Acid Oxidation in Patients With Type 2 Diabetes and Microalbuminuria

    PubMed Central

    Broedbaek, Kasper; Henriksen, Trine; Weimann, Allan; Petersen, Morten; Andersen, Jon T.; Afzal, Shoaib; Jimenez-Solem, Espen; Persson, Frederik; Parving, Hans-Henrik; Rossing, Peter; Poulsen, Henrik E.

    2011-01-01

    OBJECTIVE We tested whether long-term treatment with the angiotensin II receptor antagonist irbesartan reduces nucleic acid oxidation in patients with type 2 diabetes and microalbuminuria. RESEARCH DESIGN AND METHODS The Irbesartan in Patients With Type 2 Diabetes and Microalbuminuria (IRMA 2) study was a 2-year multicenter randomized double-blind trial comparing irbesartan (150 and 300 mg once daily) with placebo. We studied a subgroup of 50 patients where urine samples were available for analysis of albumin and the oxidatively modified guanine nucleosides 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo). RESULTS During the 2-year trial, no significant differences in 8-oxodG and 8-oxoGuo excretions between placebo and irbesartan treatment were seen. 8-oxodG and albumin excretion decreased with time (P = 0.0004 and P < 0.0001, respectively), whereas treatment-related differences were shown for albumin excretion (P = 0.0008) only, as previously reported. Important secondary findings were significant associations between changes in 8-oxodG excretion and changes in albumin excretion and glycated hemoglobin (HbA1c). During the study period, 8-oxodG excretion decreased by 3 and 26% in smokers and nonsmokers, respectively (P = 0.015), and urinary albumin excretion decreased 22% in smokers and 58% in nonsmokers (P = 0.011). CONCLUSIONS Irbesartan treatment was not significantly more effective than placebo in reducing nucleic acid oxidation. The results indicate that DNA oxidation in diabetes patients is reduced by various components in the treatment of diabetes where glycemic control seems to be important and addition of angiotensin II receptor antagonists does not lead to any substantial additional reduction. Furthermore, the reductions in DNA oxidation and albumin excretion seem to be counteracted by smoking. PMID:21454798

  2. Enhanced conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) film by acid treatment for indium tin oxide-free organic solar cells

    NASA Astrophysics Data System (ADS)

    Lin, Chun-Chiao; Huang, Chih-Kuo; Hung, Yu-Chieh; Chang, Mei-Ying

    2016-08-01

    An acid treatment is used in the enhancement of the conductivity of the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin film, which is often used as the anode in organic solar cells. There are three types of acid treatment for PEDOT:PSS thin film: hydrochloric, sulfuric, and phosphoric acid treatments. In this study, we examine and compare these three ways with each other for differences in conductivity. Hydrochloric acid results in the highest conductivity enhancement, from 0.3 to 1109 S/cm. We also discuss the optical transmittance, conductivity, surface roughness, surface morphology, and stability, as well as the factors that can influence device efficiency. The devices are fabricated using an acid-treated PEDOT:PSS thin film as the anode. The highest power conversion efficiency was 1.32%, which is a large improvement over that of the unmodified organic solar cell (0.21%). It is comparable to that obtained when using indium tin oxide (ITO) as an electrode, ca. 1.46%.

  3. Resveratrol prevents oxidative damage and loss of sperm motility induced by long-term treatment with valproic acid in Wistar rats.

    PubMed

    Ourique, Giovana M; Pês, Tanise S; Saccol, Etiane M H; Finamor, Isabela A; Glanzner, Werner G; Baldisserotto, Bernardo; Pavanato, Maria A; Gonçalves, Paulo B D; Barreto, Kátia P

    2016-09-01

    Valproic acid (VPA) is a drug widely use for the treatment of epilepsy in both children and adults. Evidence suggests that long-term use of VPA may lead to an impairment in the male reproductive function. Oxidative stress is considered to play a major role in VPA associated toxicity. In the present work, we demonstrated that the natural antioxidant compound resveratrol (RSV) can be use to prevent VPA oxidative damage. Wistar rats treated with VPA (400mgkg(-1)) by gavage for 28days showed decrease in sperm motility accompanied by increase in oxidative damage to lipids and proteins. Additionally, VPA administration leaded to depletion of reduced glutathione and decrease in total antioxidant potential in testes and epididymides of Wistar rats. The co-administration of RSV (10mgkg(-1)) efficiently prevented VPA pro-oxidant effects. In summary, RSV was shown to protect the reproductive system from the damage induced by VPA. Altogether, our data strongly suggests that RSV administration might be a valuable strategy to minimize reproductive impairment in patients requiring long-term VPA treatment.

  4. Resveratrol prevents oxidative damage and loss of sperm motility induced by long-term treatment with valproic acid in Wistar rats.

    PubMed

    Ourique, Giovana M; Pês, Tanise S; Saccol, Etiane M H; Finamor, Isabela A; Glanzner, Werner G; Baldisserotto, Bernardo; Pavanato, Maria A; Gonçalves, Paulo B D; Barreto, Kátia P

    2016-09-01

    Valproic acid (VPA) is a drug widely use for the treatment of epilepsy in both children and adults. Evidence suggests that long-term use of VPA may lead to an impairment in the male reproductive function. Oxidative stress is considered to play a major role in VPA associated toxicity. In the present work, we demonstrated that the natural antioxidant compound resveratrol (RSV) can be use to prevent VPA oxidative damage. Wistar rats treated with VPA (400mgkg(-1)) by gavage for 28days showed decrease in sperm motility accompanied by increase in oxidative damage to lipids and proteins. Additionally, VPA administration leaded to depletion of reduced glutathione and decrease in total antioxidant potential in testes and epididymides of Wistar rats. The co-administration of RSV (10mgkg(-1)) efficiently prevented VPA pro-oxidant effects. In summary, RSV was shown to protect the reproductive system from the damage induced by VPA. Altogether, our data strongly suggests that RSV administration might be a valuable strategy to minimize reproductive impairment in patients requiring long-term VPA treatment. PMID:27432062

  5. Radiofrequency-oxidation treatment of sewage sludge.

    PubMed

    Srinivasan, Asha; Young, Chris; Liao, Ping H; Lo, Kwang V

    2015-12-01

    A novel thermal-chemical treatment technology using radiofrequency heating and oxidants (hydrogen peroxide, ozone and a combination of both) was used for the treatment of sewage sludge. This was to evaluate the process effectiveness on cell disintegration and nutrient release of sludge, physical property changes such as particle size distribution, dewaterability and settleability, and their inter-relationships. The effectiveness of treatment processes was in the following order, from the most to least: thermal-oxidation process, oxidation process and thermal process. The thermal-oxidation process greatly increased cell disintegration and nutrient release, improved settleability, and decreased particle sizes. The treatment scheme involving ozone addition followed by hydrogen peroxide and radiofrequency heating yielded the highest soluble chemical oxygen demand, volatile fatty acids, ammonia and metals, while proffering the shortest capillary suction time and excellent settling properties. PMID:26233925

  6. Effect of calcium oxide on the efficiency of ferrous ion oxidation and total iron precipitation during ferrous ion oxidation in simulated acid mine drainage treatment with inoculation of Acidithiobacillus ferrooxidans.

    PubMed

    Liu, Fenwu; Zhou, Jun; Jin, Tongjun; Zhang, Shasha; Liu, Lanlan

    2016-01-01

    Calcium oxide was added into ferrous ion oxidation system in the presence of Acidithiobacillus ferrooxidans at concentrations of 0-4.00 g/L. The pH, ferrous ion oxidation efficiency, total iron precipitation efficiency, and phase of the solid minerals harvested from different treatments were investigated during the ferrous ion oxidation process. In control check (CK) system, pH of the solution decreased from 2.81 to 2.25 when ferrous ions achieved complete oxidation after 72 h of Acidithiobacillus ferrooxidans incubation without the addition of calcium oxide, and total iron precipitation efficiency reached 20.2%. Efficiency of ferrous ion oxidation and total iron precipitation was significantly improved when the amount of calcium oxide added was ≤1.33 g/L, and the minerals harvested from systems were mainly a mixture of jarosite and schwertmannite. For example, the ferrous ion oxidation efficiency reached 100% at 60 h and total iron precipitation efficiency was increased to 32.1% at 72 h when 1.33 g/L of calcium oxide was added. However, ferrous ion oxidation and total iron precipitation for jarosite and schwertmannite formation were inhibited if the amount of calcium oxide added was above 2.67 g/L, and large amounts of calcium sulfate dihydrate were generated in systems.

  7. 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)

  8. BACTERIAL OXIDATION OF DIPICOLINIC ACID I.

    PubMed Central

    Arima, Kei; Kobayashi, Yasuo

    1962-01-01

    Arima, Kei (University of Tokyo, Tokyo, Japan) and Yasuo Kobayashi. Bacterial oxidation of dipicolinic acid. I. Isolation of microorganisms, their culture conditions, and end products. J. Bacteriol. 84:759–764. 1962.—In a study of the metabolic pathway(s) of dipicolinic acid (DPA) in microorganisms, 436 strains of soil microorganisms were isolated by use of an enrichment culture technique. Most of them were bacteria, and one of them, Achromobacter, which had the strongest DPA-oxidizing activity, was used for the following experiments. In DPA-free medium, the enzymes which oxidize DPA were not produced. The best culture condition for enzyme production and cell growth was: Nutrient Broth supplemented with 0.1% DPA, 30 C, and 20 hr of shake culture. End products were oxalic acid, NH3, and CO2. Oxalic acid was not oxidized further by this bacterium. The over-all reaction equation of DPA oxidation was determined. PMID:16561964

  9. 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

  10. Treatment of Amino Acid Metabolism Disorders

    MedlinePlus

    ... Treatment of amino acid metabolism disorders Treatment of amino acid metabolism disorders E-mail to a friend Please ... this page It's been added to your dashboard . Amino acid metabolism disorders are rare health conditions that affect ...

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

    MedlinePlus

    ... sheet (Medication Guide) when you begin treatment with sodium picosulfate, magnesium oxide, and anhydrous citric acid. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda. ...

  12. Acid mine treatment with open limestone channels

    SciTech Connect

    Ziemkiewicz, P.F.; Brant, D.L.; Skousen, J.G.

    1996-12-31

    Acid mine drainage (AMD) is often associated with mining of pyritic coal and metal deposits. Typical AMD associated with coal mines in the eastern US can have acidity and iron concentrations ranging from the teens to the thousands of mg/l. Aluminum and manganese can be present in concentrations ranging from zero to the low hundreds of mg/l. Much attention has been devoted to developing inexpensive, limestone (LS)-based systems for treating AMID with little or no maintenance. However, LS tends to coat with metal hydroxides when exposed to AMID in an oxidized state, a process known as {open_quotes}armoring{close_quotes}. It is generally assumed that once armored, LS ceases to neutralize acid. Another problem is that the hydroxides tend to settle into plug the pore spaces in LS beds forcing water to move around rather than through the LS. While both are caused by the precipitation of metal hydroxides, armoring and plugging are two different problems. Plugging of LS pores can be avoided by maintaining a high flushing rate through the LS bed. Armoring, however, occurs regardless of water velocity. This study investigated the influence of armoring on LS solubility and the implications of armoring and plugging on the construction of open (oxidizing) LS channels for treating AMD. We evaluated the AMID treatment performance of armored and unarmored LS in oxidizing environments both in laboratory and field studies.

  13. The Effects of Mary Rose Conservation Treatment on Iron Oxidation Processes and Microbial Communities Contributing to Acid Production in Marine Archaeological Timbers

    PubMed Central

    Preston, Joanne; Smith, Andrew D.; Schofield, Eleanor J.; Chadwick, Alan V.; Jones, Mark A.; Watts, Joy E. M.

    2014-01-01

    The Tudor warship the Mary Rose has reached an important transition point in her conservation. The 19 year long process of spraying with polyethylene glycol (PEG) has been completed (April 29th 2013) and the hull is air drying under tightly controlled conditions. Acidophilic bacteria capable of oxidising iron and sulfur have been previously identified and enriched from unpreserved timbers of the Mary Rose, demonstrating that biological pathways of iron and sulfur oxidization existed potentially in this wood, before preservation with PEG. This study was designed to establish if the recycled PEG spray system was a reservoir of microorganisms capable of iron and sulfur oxidization during preservation of the Mary Rose. Microbial enrichments derived from PEG impregnated biofilm collected from underneath the Mary Rose hull, were examined to better understand the processes of cycling of iron. X-ray absorption spectroscopy was utilised to demonstrate the biological contribution to production of sulfuric acid in the wood. Using molecular microbiological techniques to examine these enrichment cultures, PEG was found to mediate a shift in the microbial community from a co-culture of Stenotrophomonas and Brevunidimonas sp, to a co-culture of Stenotrophomonas and the iron oxidising Alicyclobacillus sp. Evidence is presented that PEG is not an inert substance in relation to the redox cycling of iron. This is the first demonstration that solutions of PEG used in the conservation of the Mary Rose are promoting the oxidation of ferrous iron in acidic solutions, in which spontaneous abiotic oxidation does not occur in water. Critically, these results suggest PEG mediated redox cycling of iron between valence states in solutions of 75% PEG 200 and 50% PEG 2000 (v/v) at pH 3.0, with serious implications for the future use of PEG as a conservation material of iron rich wooden archaeological artefacts. PMID:24586230

  14. Oxidative stability of fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of polyunsaturated fatty acids in poultry feeds follows the recent trend in the food industry to fortify processed foods with health promoting supplements. The chemical structure of these compounds presents a challenge to the feed formulator and producer that must contend with such unstable ...

  15. Impact of leachate composition on the advanced oxidation treatment.

    PubMed

    Oulego, Paula; Collado, Sergio; Laca, Adriana; Díaz, Mario

    2016-01-01

    Advanced oxidation processes (AOPs) are gaining importance as an alternative to the biological or physicochemical treatments for the management of leachates. In this work, it has been studied the effect of the characteristics of the leachate (content in humic acids, landfill age and degree of stabilization) on the wet oxidation process and final quality of the treated effluent. A high concentration of humic acids in the leachate had a positive effect on the COD removal because this fraction is more easily oxidizable. Additionally, it has been demonstrated that the simultaneous presence of humic acid and the intermediates generated during the oxidation process improved the degradation of this acid, since such intermediates are stronger initiators of free radicals than the humic acid itself. Similar values of COD removals (49% and 51%) and biodegradability indices (0.30 and 0.35) were observed, after 8 h of wet oxidation, for the stabilised leachate (biologically pretreated) and the raw one, respectively. Nevertheless, final colour removal was much higher for the stabilised leachate, achieving values up to 91%, whereas for the raw one only 56% removal was attained for the same reaction time. Besides, wet oxidation treatment was more efficient for the young leachate than for the old one, with final COD conversions of 60% and 37%, respectively. Eventually, a triangular "three-lump" kinetic model, which considered direct oxidation to CO2 and partial oxidation through intermediate compounds, was here proposed.

  16. 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.

  17. 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.

  18. The interaction of carboxylic acids with aluminium oxides: journeying from a basic understanding of alumina nanoparticles to water treatment for industrial and humanitarian applications.

    PubMed

    Barron, Andrew R

    2014-06-14

    Carboxylic acids are found to react with aluminium oxides via a topotactic reaction such that the carboxylate acts as a bridging ligand. This reaction allows for carboxylate-functionalized alumina nanoparticles to be prepared directly from boehmite (AlOOH). Understanding the structural relationship between molecular and surface species allows for the rationalization/prediction of suitable alternative ligands as well as alternative oxide surfaces. The identity of the carboxylate substituent controls the pH stability of a nanoparticle as well as the porosity and processability of ceramics prepared by thermolysis. Through the choice of functional groups on the carboxylic acid the properties of the alumina surface or alumina nanoparticle can be tailored. For example, the solubility/miscibility of nanoparticles can be tuned to the solvent/matrix, and the wettability to be varied from hydrophobic to super hydrophilic. The choice Zwitter ionic substituents on alumina micro-/ultra-filtration membranes are found to enhance the flux and limit fouling while allowing for the facile separation of organic compounds from water. Examples are presented of purification of frac and flow-back water from oil well production as well as providing drinking water from contaminated sources in underdeveloped regions.

  19. The interaction of carboxylic acids with aluminium oxides: journeying from a basic understanding of alumina nanoparticles to water treatment for industrial and humanitarian applications.

    PubMed

    Barron, Andrew R

    2014-06-14

    Carboxylic acids are found to react with aluminium oxides via a topotactic reaction such that the carboxylate acts as a bridging ligand. This reaction allows for carboxylate-functionalized alumina nanoparticles to be prepared directly from boehmite (AlOOH). Understanding the structural relationship between molecular and surface species allows for the rationalization/prediction of suitable alternative ligands as well as alternative oxide surfaces. The identity of the carboxylate substituent controls the pH stability of a nanoparticle as well as the porosity and processability of ceramics prepared by thermolysis. Through the choice of functional groups on the carboxylic acid the properties of the alumina surface or alumina nanoparticle can be tailored. For example, the solubility/miscibility of nanoparticles can be tuned to the solvent/matrix, and the wettability to be varied from hydrophobic to super hydrophilic. The choice Zwitter ionic substituents on alumina micro-/ultra-filtration membranes are found to enhance the flux and limit fouling while allowing for the facile separation of organic compounds from water. Examples are presented of purification of frac and flow-back water from oil well production as well as providing drinking water from contaminated sources in underdeveloped regions. PMID:24728503

  20. Effects of oxidative treatments on human hair keratin films.

    PubMed

    Fujii, T; Ito, Y; Watanabe, T; Kawasoe, T

    2012-01-01

    The effects of hydrogen peroxide and commercial bleach on hair and human hair keratin films were examined by protein solubility, scanning electron microscopy (SEM), immunofluorescence microscopy, immunoblotting, and Fourier-transform infrared spectroscopy. Protein solubility in solutions containing urea decreased when the keratin films were treated with hydrogen peroxide or bleach. Oxidative treatments promoted the urea-dependent morphological change by turning films from opaque to transparent in appearance. Immunofluorescence microscopy and immunoblotting showed that the oxidation of amino acids and proteins occurred due to the oxidative treatments, and such occurrence was more evident in the bleach-treated films than in the hydrogen peroxide-treated films. Compared with hair samples, the formation of cysteic acid was more clearly observed in the keratin films after the oxidative treatments.

  1. Effects of oxidative treatments on human hair keratin films.

    PubMed

    Fujii, T; Ito, Y; Watanabe, T; Kawasoe, T

    2012-01-01

    The effects of hydrogen peroxide and commercial bleach on hair and human hair keratin films were examined by protein solubility, scanning electron microscopy (SEM), immunofluorescence microscopy, immunoblotting, and Fourier-transform infrared spectroscopy. Protein solubility in solutions containing urea decreased when the keratin films were treated with hydrogen peroxide or bleach. Oxidative treatments promoted the urea-dependent morphological change by turning films from opaque to transparent in appearance. Immunofluorescence microscopy and immunoblotting showed that the oxidation of amino acids and proteins occurred due to the oxidative treatments, and such occurrence was more evident in the bleach-treated films than in the hydrogen peroxide-treated films. Compared with hair samples, the formation of cysteic acid was more clearly observed in the keratin films after the oxidative treatments. PMID:22487448

  2. Acetylsalicylic acid and acetaminophen protect against oxidative neurotoxicity.

    PubMed

    Maharaj, H; Maharaj, D S; Daya, S

    2006-09-01

    Due to the implication of oxidative stress in neurodegenerative disorders we decided to investigate the antioxidant properties of acetylsalicylic acid and acetaminophen either alone or in combination. The thiobarbituric acid assay (TBA) and the nitroblue tetrazolium (NBT) assay were used to investigate quinolinic acid (QA)-induced: lipid peroxidation and superoxide anion generation in the rat hippocampus, in vivo. The study also shows, using cresyl violet staining, the preservation of structural integrity of neuronal cells following treatment with acetylsalicylic acid and acetaminophen in QA-lesioned rat hippocampus. Furthermore the study sought to determine whether these agents have any effect on endogenous (QA) formation. This study shows that acetylsalicylic acid and acetaminophen inhibit QA-induced superoxide anion generation, lipid peroxidation and cell damage, in vivo, in the rat hippocampus. In addition these agents inhibit the enzyme, 3-hydroxyanthranilic acid oxygenase (3-HAO), responsible for the synthesis of endogenous QA.

  3. 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.

  4. Treatment of aqueous streams containing strong oxidants using bituminous coal

    SciTech Connect

    Doyle, F.M.; Bodine, D.L.

    1995-12-31

    Certain oxidizing contaminants, notably Cr(VI) and Mn(VII), are attenuated by reduction and sorption on organic matter in soils. Coals have some chemical similarity with this organic matter, and might be used on an industrial scale to treat effluents. We have studied the ability of acidic KMnO{sub 4} to oxidize Upper Freeport, bituminous coal with concurrent sorption of the resulting Mn(IV) and Mn(II). The oxidizing ability of Cr(VI) was briefly investigated. The ability of the oxidized coal to sorb Cu{sup 2+} and Cd{sup 2+} was then studied, and compared with coal oxidized by hydrogen peroxide. The effect of oxidation treatment, metal ion concentration, and solution pH on metal uptake kinetics and coal loading was investigated. Potential applications for treating effluents containing oxidizing ions are discussed.

  5. Germanium oxide removal by citric acid and thiol passivation from citric acid-terminated Ge(100).

    PubMed

    Collins, Gillian; Aureau, Damien; Holmes, Justin D; Etcheberry, Arnaud; O'Dwyer, Colm

    2014-12-01

    Many applications of germanium (Ge) are underpinned by effective oxide removal and surface passivation. This important surface treatment step often requires H-X (X = Cl, Br, I) or HF etchants. Here, we show that aqueous citric acid solutions are effective in the removal of GeOx. The stability of citric acid-treated Ge(100) is compared to HF and HCl treated surfaces and analyzed by X-ray photoelectron spectroscopy. Further Ge surface passivation was investigated by thiolation using alkane monothiols and dithiols. The organic passivation layers show good stability with no oxide regrowth observed after 3 days of ambient exposure.

  6. Fast and efficient benign oxidation of native wheat starch by acidic bromate under microwave activation.

    PubMed

    Komulainen, Sanna; Diaz, Estibaliz; Pursiainen, Jouni; Lajunen, Marja

    2013-02-15

    A simple oxidation of starch in water by bromate was substantially improved by microwave activation. In the oxidation of native wheat starch its advantages were the highly reduced need of oxidant from 1.05 to 0.1-0.25 equiv, shortened reaction time from 2 to 5.5h to 10 min, and moderate or high yields of oxidation content (degree of oxidation 0.22-0.55) of water-soluble products. Acidic treatment before the oxidation reaction promoted the carbonyl formation yielding higher contents of oxidized products (degree of oxidation 0.43-0.55) than without it (degree of oxidation 0.22-0.28). The pretreatment did not have similar effect on the amount of carboxyl groups. The oxidation route of acidic bromate oxidation of starch is discussed.

  7. Electrochemical oxidation for landfill leachate treatment

    SciTech Connect

    Deng, Yang Englehardt, James D.

    2007-07-01

    This paper aims at providing an overview of electrochemical oxidation processes used for treatment of landfill leachate. The typical characteristics of landfill leachate are briefly reviewed, and the reactor designs used for electro-oxidation of leachate are summarized. Electrochemical oxidation can significantly reduce concentrations of organic contaminants, ammonia, and color in leachate. Pretreatment methods, anode materials, pH, current density, chloride concentration, and other additional electrolytes can considerably influence performance. Although high energy consumption and potential chlorinated organics formation may limit its application, electrochemical oxidation is a promising and powerful technology for treatment of landfill leachate.

  8. Treatment of Radioactive Organic Wastes by an Electrochemical Oxidation

    SciTech Connect

    Kim, K.H.; Ryue, Y.G.; Kwak, K.K.; Hong, K.P.; Kim, D.H.

    2007-07-01

    A waste treatment system by using an electrochemical oxidation (MEO, Mediated Electrochemical Oxidation) was installed at KAERI (Korea Atomic Energy Research Institute) for the treatment of radioactive organic wastes, especially EDTA (Ethylene Diamine Tetraacetic Acid) generated during the decontamination activity of nuclear installations. A cerium and silver mediated electrochemical oxidation technique method has been developed as an alternative for an incineration process. An experiment to evaluate the applicability of the above two processes and to establish the conditions to operate the pilot-scale system has been carried out by changing the concentration of the catalyst and EDTA, the operational current density, the operating temperature, and the electrolyte concentration. As for the results, silver mediated oxidation was more effective in destructing the EDTA wastes than the cerium mediated oxidation process. For a constant volume of the EDTA wastes, the treatment time for the cerium-mediated oxidation was 9 hours and its conversion ratio of EDTA to water and CO{sub 2} was 90.2 % at 80 deg. C, 10 A, but the treatment time for the silver-mediated oxidation was 3 hours and its conversion ratio was 89.2 % at 30 deg. C, 10 A. (authors)

  9. 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

  10. A simple screening test for fatty acid oxidation defects using whole-blood palmitate oxidation.

    PubMed

    Seargeant, L E; Balachandra, K; Mallory, C; Dilling, L A; Greenberg, C R

    1999-08-01

    We report that measurement of whole-blood palmitate oxidation is a rapid and inexpensive screening test for fatty acid oxidation defects. The assay has been adapted from published assays using cultured fibroblasts or isolated white blood cells. Micro whole-blood samples are incubated with tritiated palmitic acid as substrate. The tritiated water produced is proportional to the mitochondrial beta-oxidation of palmitic acid. Patients with confirmed beta-oxidation defects show low whole-blood palmitate oxidation.

  11. Efficient, chemical-catalytic approach to the production of 3-hydroxypropanoic acid by oxidation of biomass-derived levulinic acid with hydrogen peroxide.

    PubMed

    Wu, Linglin; Dutta, Saikat; Mascal, Mark

    2015-04-13

    3-Hydroxypropanoic acid (HPA), a precursor to acrylic acid, can be produced in high yield by oxidation of the biomass-derived platform chemical levulinic acid. While treatment of levulinic acid with H2 O2 under acidic conditions gives predominantly succinic acid, a remarkable reversal of selectivity is observed under basic conditions, leading either directly to HPA or, under modified conditions, initially to 3-(hydroperoxy)propanoic acid, which can be quantitatively hydrogenated to HPA. PMID:25736835

  12. Treatment of Bile Acid Amidation Defects with Glycocholic Acid

    PubMed Central

    Heubi, James E.; Setchell, Kenneth D.R.; Jha, Pinky; Buckley, Donna; Zhang, Wujuan; Rosenthal, Philip; Potter, Carol; Horslen, Simon; Suskind, David

    2014-01-01

    Bile acid amidation defects were predicted to present with fat/fat soluble vitamin malabsorption with minimal cholestasis. We identified and treated 5 patients (1 male/4 females) from 4 families with defective bile acid amidation due to a genetically confirmed deficiency in bile acid CoA:amino acid N-acyl transferase (BAAT) with the conjugated bile acid, glycocholic acid (GCA). Fast atom bombardment-mass spectrometry analysis of urine and bile at baseline revealed predominantly unconjugated cholic acid and absence of the usual glycine and taurine conjugated primary bile acids. Treatment with 15 mg/kg GCA resulted in total duodenal bile acid concentrations of 23.3 ± 19.1 mmol/L (mean ± SD) and 63.5 ± 4.0% of the bile acids were secreted in bile in the conjugated form of which GCA represented 59.6 ± 9.3% of the total biliary bile acids. Unconjugated cholic acid continued to be present in high concentrations in bile because of partial intestinal deconjugation of orally administered GCA. Serum total bile acid concentrations did not significantly differ between pretreatment and post-treatment samples and serum contained predominantly unconjugated cholic acid. These findings confirmed efficient intestinal absorption, hepatic extraction and biliary secretion of the administered GCA. Oral tolerance tests for vitamin D2 (1000 IU vitamin D2/kg) and tocopherol (100 IU/kg tocopherol acetate) demonstrated improvement in fat-soluble vitamin absorption after GCA treatment. Growth improved in 3/3 growth-delayed prepubertal patients. Conclusions: Oral glycocholic acid therapy is safe and effective in improving growth and fat-soluble vitamin absorption in children and adolescents with inborn errors of bile acid metabolism due to amidation defects. PMID:25163551

  13. Oxidative particle mixtures for groundwater treatment

    DOEpatents

    Siegrist, Robert L.; Murdoch, Lawrence C.

    2000-01-01

    The invention is a method and a composition of a mixture for degradation and immobilization of contaminants in soil and groundwater. The oxidative particle mixture and method includes providing a material having a minimal volume of free water, mixing at least one inorganic oxidative chemical in a granular form with a carrier fluid containing a fine grained inorganic hydrophilic compound and injecting the resulting mixture into the subsurface. The granular form of the inorganic oxidative chemical dissolves within the areas of injection, and the oxidative ions move by diffusion and/or advection, therefore extending the treatment zone over a wider area than the injection area. The organic contaminants in the soil and groundwater are degraded by the oxidative ions, which form solid byproducts that can sorb significant amounts of inorganic contaminants, metals, and radionuclides for in situ treatment and immobilization of contaminants. The method and composition of the oxidative particle mixture for long-term treatment and immobilization of contaminants in soil and groundwater provides for a reduction in toxicity of contaminants in a subsurface area of contamination without the need for continued injection of treatment material, or for movement of the contaminants, or without the need for continuous pumping of groundwater through the treatment zone, or removal of groundwater from the subsurface area of contamination.

  14. Nitric-phosphoric acid treatment of TRU wastes

    SciTech Connect

    Smith, J.R.; Pierce, R.A.; Sturcken, E.F.

    1993-09-30

    A general process is being developed for the treatment of solid TRU and hazardous organic waste. Experimental data indicates that 100 lb/hr of aliphatic organic (plastics) and 1,000 lb/hr of non-aliphatic organic compounds can be quantitatively oxidized in a 1,000 gallon reaction vessel. The process uses dilute nitric acid in a concentrated phosphoric acid media as the main oxidant for the organic compounds. Phosphoric acid allows oxidation at temperatures up to 200{degrees}C and is relatively non-corrosive on 304-L stainless steel, especially at room temperature. Many organic materials have been completely oxidized to CO{sub 2}, CO, and inorganic acids in a 0.1M HNO{sub 3}/14.8M H{sub 3}PO{sub 4} solution. Addition of 0.001M Pd{sup 2+} reduces the CO to near 1% of the released carbon gases. To accomplish complete oxidation the solution temperature must be maintained above 130--150{degrees}C. Organic materials quantitatively destroyed include neoprene, cellulose, EDTA, TBP, tartaric acid, and nitromethane. The oxidation is usually complete in a few hours for soluble organic materials. The oxidation rate for non-aliphatic organic solids is moderately fast and surface area dependent. Polyethylene is quantitatively oxidized in 1.0M HNO{sub 3}/13.8M H{sub 3}PO{sub 4} solution while contained in pressure vessels heated with microwave energy. This is probably due to the high concentrations of NO{sub 2}{center_dot} obtained in the reaction environment.

  15. Acid mine water treatment using engineered wetlands

    NASA Astrophysics Data System (ADS)

    Kleinmann, Robert L. P.

    1990-03-01

    During the last two decades, the United States mining industry has greatly increased the amount it spends on pollution control. The application of biotechnology to mine water can reduce the industry's water treatment costs (estimated at over a million dollars a day) and improve water quality in streams and rivers adversely affected by acidic mine water draining from abandoned mines. Biological treatment of mine waste water is typically conducted in a series of small excavated ponds that resemble, in a superficial way, a small marsh area. The ponds are engineered to first facilitate bacterial oxidation of iron; ideally, the water then flows through a composted organic substrate that supports a population of sulfate-reducing bacteria. The latter process raises the pH. During the past four years, over 400 wetland water treatment systems have been built on mined lands as a result of research by the U.S. Bureau of Mines. In general, mine operators find that the wetlands reduce chemical treatment costs enough to repay the cost of wetland construction in less than a year. Actual rates of iron removal at field sites have been used to develop empirical sizing criteria based on iron loading and pH. If the pH is 6 or above, the wetland area (m2) required is equivalent to the iron load (grams/day) divided by 10. Theis requirement doubles at a pH of 4 to 5. At a pH below 4, the iron load (grams/day) should be divided by 2 to estimate the area required (m2).

  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. 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.

  18. 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...

  19. Electrometallurgical treatment of oxide spent fuel.

    SciTech Connect

    Karell, E. J.

    1999-06-08

    The Department of Energy (DOE) inventory of spent nuclear fuel contains a wide variety of oxide fuel types that may be unsuitable for direct repository disposal in their current form. The molten-salt electrometallurgical treatment technique developed by Argonne National Laboratory (ANL) has the potential to simplify preparing and qualifying these fuels for disposal by converting them into three uniform product streams: uranium metal, a metal waste form, and a ceramic waste form. This paper describes the major steps in the electrometallurgical treatment process for oxide fuels and provides the results of recent experiments performed to develop and scale up the process.

  20. 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.

  1. Acid peptic diseases: pharmacological approach to treatment

    PubMed Central

    Mejia, Alex; Kraft, Walter K

    2011-01-01

    Acid peptic disorders are the result of distinctive, but overlapping pathogenic mechanisms leading to either excessive acid secretion or diminished mucosal defense. They are common entities present in daily clinical practice that, owing to their chronicity, represent a significant cost to healthcare. Key elements in the success of controlling these entities have been the development of potent and safe drugs based on physiological targets. The histamine-2 receptor antagonists revolutionized the treatment of acid peptic disorders owing to their safety and efficacy profile. The proton-pump inhibitors (PPIs) represent a further therapeutic advance due to more potent inhibition of acid secretion. Ample data from clinical trials and observational experience have confirmed the utility of these agents in the treatment of acid peptic diseases, with differential efficacy and safety characteristics between and within drug classes. Paradigms in their speed and duration of action have underscored the need for new chemical entities that, from a single dose, would provide reliable duration of acid control, particularly at night. Moreover, PPIs reduce, but do not eliminate, the risk of ulcers in patients taking NSAIDs, reflecting untargeted physiopathologic pathways and a breach in the ability to sustain an intragastric pH of more than 4. This review provides an assessment of the current understanding of the physiology of acid production, a discussion of medications targeting gastric acid production and a review of efficacy in specific acid peptic diseases, as well as current challenges and future directions in the treatment of acid-mediated diseases. PMID:21822447

  2. Lignor process for acidic rock drainage treatment.

    PubMed

    Zhuang, J M; Walsh, T

    2004-09-01

    The process using lignosulfonates for acidic rock drainage (ARD) treatment is referred to as the Lignor process. Lignosulfonates are waste by-products produced in the sulfite pulping process. The present study has shown lignosulfonates are able to protect lime from developing an external surface coating, and hence to favor its dissociation. Further, the addition of lignosulfonates to ARD solutions increased the dotting and settling rate of the formed sludge. The capability of lignosulfonates to form stable metal-lignin complexes makes them very useful in retaining metal ions and thus improving the long-term stability of the sludge against leaching. The Lignor process involves metal sorption with lignosulfonates, ARD neutralization by lime to about pH 7, pH adjustment with caustic soda to 9.4 - 9.6, air oxidation to lower the pH to a desired level, and addition of a minimum amount of FeCl3 for further removal of dissolved metals. The Lignor process removes all concerned metals (especially Al and Mn) from the ARD of the Britannia Mine (located at Britannia Beach, British Columbia, Canada) to a level lower than the limits of the B.C. Regulations. Compared with the high-density sludge (HDS) process, the Lignor process has many advantages, such as considerable savings in lime consumption, greatly reduced sludge volume, and improved sludge stability. PMID:15515269

  3. Treatment of Escherichia coli O157:H7 with lactic acid, neutralized electrolyzed oxidizing water and chlorine dioxide followed by growth under sub-optimal conditions of temperature, pH and modified atmosphere.

    PubMed

    Smigic, Nada; Rajkovic, Andreja; Antal, Eszter; Medic, Helga; Lipnicka, Barbara; Uyttendaele, Mieke; Devlieghere, Frank

    2009-09-01

    The utilization of sub-lethal decontamination treatments gains more and more interest due to the increased consumers' demand for fresh, minimally processed and convenient food products. These products rely on cold chain and hurdle (combination) technology to provide microbiological safety and quality during their shelf life. To investigate the ability of surviving cells to resuscitate and grow in a food simulating environment, sub-lethal decontamination treatments were coupled with subsequent storage under sub-optimal growth conditions. For this purpose chlorine dioxide (ClO2) and neutralized electrolyzed oxidizing water (NEW)-treated cultures of Escherichia coli O157:H7 were inoculated in TSB-YE of pH 5.8 and aw 0.99, and stored at 10 degrees C, 12.5 degrees C and 15 degrees C, under four different atmospheres (0%, 30% and 60% CO2 balanced with N2, and air). Due to the severity of injury, lactic acid-treated cells were inoculated in TSB-YE pH 7.0. Data obtained reveal that the fraction of sub-lethally injured E. coli O157:H7 undergoes an additional inhibitory effect during the storage period under of sub-optimal conditions. Observed extension in the lag growth phase was a direct consequence prior sub-lethal injury. The effects of liquid ClO2 and NEW were less pronounced in comparison to lactic acid. The current study signifies the potential utilization of appropriate combination of different extrinsic and intrinsic factors in the elimination or growth inhibition of food-borne pathogens.

  4. Microwave oxidation treatment of sewage sludge.

    PubMed

    Lo, Kwang V; Srinivasan, Asha; Liao, Ping H; Bailey, Sam

    2015-01-01

    Microwave-oxidation treatment of sewage sludge using various oxidants was studied. Two treatment schemes with a combination of hydrogen peroxide and ozone were examined: hydrogen peroxide and ozone were introduced into the sludge simultaneously, followed by microwave heating. The other involved the ozonation first, and then the resulting solution was subjected to microwave and hydrogen peroxide treatment. The set with ozonation followed by hydrogen peroxide plus microwave heating yielded higher soluble materials than those of the set with hydrogen peroxide plus ozone first and then microwave treatment. No settling was observed for all treatments in the batch operation, except ozone/microwave plus hydrogen peroxide set at 120°C. The pilot-scale continuous-flow 915 MHz microwave study has demonstrated that microwave-oxidation process is feasible for real-time industrial application. It would help in providing key data for the design of a full-scale system for treating sewage sludge and the formulation of operational protocols.

  5. '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

  6. Effect of ascorbic acid on blood oxidative stress in experimental chronic arsenicosis in rodents.

    PubMed

    Rana, Tanmoy; Bera, Asit Kumar; Das, Subhashree; Pan, Diganta; Bandyopadhyay, Subhasish; Bhattacharya, Debasis; De, Sumanta; Sikdar, Sourav; Das, Subrata Kumar

    2010-04-01

    Ascorbic acid is a sugar acid and an essential vital food nutrient found mainly in fruits and vegetables. The purpose of this study was to investigate the effects of ascorbic acid against arsenic induced oxidative stress in blood of rat. In rat, treatment with ascorbic acid prevented the increased serum enzymatic activity of AST, ALT, ALP, ACP and LDH. In addition, treatment with ascorbic acid prevented elevated production of LPO, PC and NO and restored the depletion of reduced SOD and CAT activities. Interestingly, ascorbic acid markedly upregulated lymphocytes relative mRNA expression of lymphocytes SOD2 gene corresponding to GAPDH, house keeping candidate gene in arsenic-treated rat, which might provide anti-oxidative activity in the blood. PMID:20122981

  7. Effect of ascorbic acid on blood oxidative stress in experimental chronic arsenicosis in rodents.

    PubMed

    Rana, Tanmoy; Bera, Asit Kumar; Das, Subhashree; Pan, Diganta; Bandyopadhyay, Subhasish; Bhattacharya, Debasis; De, Sumanta; Sikdar, Sourav; Das, Subrata Kumar

    2010-04-01

    Ascorbic acid is a sugar acid and an essential vital food nutrient found mainly in fruits and vegetables. The purpose of this study was to investigate the effects of ascorbic acid against arsenic induced oxidative stress in blood of rat. In rat, treatment with ascorbic acid prevented the increased serum enzymatic activity of AST, ALT, ALP, ACP and LDH. In addition, treatment with ascorbic acid prevented elevated production of LPO, PC and NO and restored the depletion of reduced SOD and CAT activities. Interestingly, ascorbic acid markedly upregulated lymphocytes relative mRNA expression of lymphocytes SOD2 gene corresponding to GAPDH, house keeping candidate gene in arsenic-treated rat, which might provide anti-oxidative activity in the blood.

  8. Mitochondrial Fatty Acid Oxidation in Obesity

    PubMed Central

    Serra, Dolors; Mera, Paula; Malandrino, Maria Ida; Mir, Joan Francesc

    2013-01-01

    Abstract Significance: Current lifestyles with high-energy diets and little exercise are triggering an alarming growth in obesity. Excess of adiposity is leading to severe increases in associated pathologies, such as insulin resistance, type 2 diabetes, atherosclerosis, cancer, arthritis, asthma, and hypertension. This, together with the lack of efficient obesity drugs, is the driving force behind much research. Recent Advances: Traditional anti-obesity strategies focused on reducing food intake and increasing physical activity. However, recent results suggest that enhancing cellular energy expenditure may be an attractive alternative therapy. Critical Issues: This review evaluates recent discoveries regarding mitochondrial fatty acid oxidation (FAO) and its potential as a therapy for obesity. We focus on the still controversial beneficial effects of increased FAO in liver and muscle, recent studies on how to potentiate adipose tissue energy expenditure, and the different hypotheses involving FAO and the reactive oxygen species production in the hypothalamic control of food intake. Future Directions: The present review aims to provide an overview of novel anti-obesity strategies that target mitochondrial FAO and that will definitively be of high interest in the future research to fight against obesity-related disorders. Antioxid. Redox Signal. 19, 269–284. PMID:22900819

  9. Enhanced arsenite removal through surface-catalyzed oxidative coagulation treatment.

    PubMed

    Li, Yue; Bland, Garret D; Yan, Weile

    2016-05-01

    Arsenic being a naturally-occurring groundwater contaminant is subject to stringent water quality regulations. Coagulation and adsorption are widely used methods to treat arsenic-contaminated water, however, these treatments have been reported to be less efficient for the removal of arsenite (As(III)) than arsenate (As(V)). In this study, the feasibility of in situ oxidation of As(III) during coagulation was investigated in two systems: Fe(II) or H2O2-assisted oxidative coagulation treatment using ferric chloride as the coagulant. This setup exploits the catalytic property of the fresh formed Fe(III) hydroxide colloids in coagulation suspension to mediate the production of reactive oxidants capable of As(III) oxidation. Fe(II)-assisted coagulation brought about small improvements in As(III) removal compared to treatment with Fe(III) coagulant alone, however, its arsenic removal efficiency is strongly dependent on pH (observed optimal pH = 7-9). Addition of H2O2 together with ferric chloride led to a significant enhancement in arsenic retention at pH 6-8, with final arsenic concentrations well below the U.S.EPA regulatory limit (10 μg/L). H2O2-assisted oxidative coagulation can attain reliable As(III) removal over a broad pH range of 4-9. Radical quenching experiments reveal the participation of superoxide radical in As(III) removal in the oxidative coagulation systems. Phosphate (at > 0.1 mM) strongly suppresses As(III) removal efficiency, whereas carbonate and humic acid pose a minor impact. Overall, the results suggest that a low dose addition of H2O2 along with ferric coagulant is a feasible method for the existing water treatment facilities to achieve improved As(III) removal efficiency. PMID:26897520

  10. Treatment of waste containing EDTA by chemical oxidation

    SciTech Connect

    Tucker, M.D.; Barton, L.L.; Thomson, B.M.; Wagener, B.M.; Aragon, A.

    1999-07-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent that has been extensively used to enhance the solubilization of heavy metal cations and release of EDTA contributes to environmental problems. EDTA is recalcitrant to microbial metabolism and chemical oxidation is considered a possible method of remedial treatment. The use of the commercially available process of MIOX Corporation generates mixed oxidants on site and this solution is markedly effective in the destruction of the chelating characteristic and the decarboxylation of EDTA. When measuring the release of C-14 from carboxyl labeled EDTA, the mixed oxidant solution was comparable to the Fenton's reaction over a broad pH range. The presence of Mn{sup 2+}, Cr{sup 3+}, or Fe{sup 3+} at levels equal to that of EDTA stimulated the rate of EDTA decomposition; however, the rate of EDTA breakdown was inhibited when the concentration of Cr{sup 3+} or Mn{sup 2+} exceeded the concentration of EDTA. The treatment of Co{sup 2+} -EDTA or Cu{sup 2+} -EDTA with mixed oxidants in the presence of ultra violet light resulted in the loss of chelation ability of EDTA. In the absence of chelated metals, over 75% of the chelation property of a 70 nM EDTA solution was destroyed in 45 min. The reaction products resulting from the use of mixed oxidants added to EDTA were non-toxic to bacteria and should not contribute to additional environmental problems.

  11. Treatment of broiler litter with organic acids.

    PubMed

    Ivanov, I E

    2001-04-01

    Experiments for treatment of contaminated broiler litter with citric, tartaric and salicylic acids were performed. At days 2 and 6 after the treatment, pH values (using a pH-meter), the ammonia concentrations (titration with 0.1 N HCl) and the microbial cells counts were determined in both experimental and control specimens of litter. The cost of acidification of litter was also determined. Our studies showed that the treatment of the contaminated litter with 5 per cent citric acid, 4 per cent tartaric acid and 1.5 per cent salicylic acid created an acid medium with pH under 5.0 and thus reduced the microbial counts to 2.2 x 10(3)colony forming units per gram manure litter. The treatment reduced the content of ammonia in the litter and in the air under the hygienic limits, i.e. 25-50 ppm. The cost of acidification of litter with these organic acids amounted to 0.1 $ per bird and 1.5 $ per 15 birds on one square metre in a growth period of 50 days. PMID:11356097

  12. Oxidative stress and nucleic acid oxidation in patients with chronic kidney disease.

    PubMed

    Sung, Chih-Chien; Hsu, Yu-Chuan; Chen, Chun-Chi; Lin, Yuh-Feng; Wu, Chia-Chao

    2013-01-01

    Patients with chronic kidney disease (CKD) have high cardiovascular mortality and morbidity and a high risk for developing malignancy. Excessive oxidative stress is thought to play a major role in elevating these risks by increasing oxidative nucleic acid damage. Oxidative stress results from an imbalance between reactive oxygen/nitrogen species (RONS) production and antioxidant defense mechanisms and can cause vascular and tissue injuries as well as nucleic acid damage in CKD patients. The increased production of RONS, impaired nonenzymatic or enzymatic antioxidant defense mechanisms, and other risk factors including gene polymorphisms, uremic toxins (indoxyl sulfate), deficiency of arylesterase/paraoxonase, hyperhomocysteinemia, dialysis-associated membrane bioincompatibility, and endotoxin in patients with CKD can inhibit normal cell function by damaging cell lipids, arachidonic acid derivatives, carbohydrates, proteins, amino acids, and nucleic acids. Several clinical biomarkers and techniques have been used to detect the antioxidant status and oxidative stress/oxidative nucleic acid damage associated with long-term complications such as inflammation, atherosclerosis, amyloidosis, and malignancy in CKD patients. Antioxidant therapies have been studied to reduce the oxidative stress and nucleic acid oxidation in patients with CKD, including alpha-tocopherol, N-acetylcysteine, ascorbic acid, glutathione, folic acid, bardoxolone methyl, angiotensin-converting enzyme inhibitor, and providing better dialysis strategies. This paper provides an overview of radical production, antioxidant defence, pathogenesis and biomarkers of oxidative stress in patients with CKD, and possible antioxidant therapies.

  13. Acetic Acid bacteria: physiology and carbon sources oxidation.

    PubMed

    Mamlouk, Dhouha; Gullo, Maria

    2013-12-01

    Acetic acid bacteria (AAB) are obligately aerobic bacteria within the family Acetobacteraceae, widespread in sugary, acidic and alcoholic niches. They are known for their ability to partially oxidise a variety of carbohydrates and to release the corresponding metabolites (aldehydes, ketones and organic acids) into the media. Since a long time they are used to perform specific oxidation reactions through processes called "oxidative fermentations", especially in vinegar production. In the last decades physiology of AAB have been widely studied because of their role in food production, where they act as beneficial or spoiling organisms, and in biotechnological industry, where their oxidation machinery is exploited to produce a number of compounds such as l-ascorbic acid, dihydroxyacetone, gluconic acid and cellulose. The present review aims to provide an overview of AAB physiology focusing carbon sources oxidation and main products of their metabolism.

  14. 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.

  15. Lagoons and oxidation ponds. [Wastewater treatment

    SciTech Connect

    George, D.B.

    1982-06-01

    A review of the literature on waste stabilization pond systems is presented. Factors such as wastewater temperature, and levels of heavy metals that affect the stability of the lagoons and oxidation ponds, and methods to upgrade stabilization pond effluent to meet state and federal effluent requirements are discussed. Model simulations utilized to predict the treatment efficiency of various waste stabilization pond geometries, and inlet and outlet configurations are reviewed. (KRM)

  16. Nitrous oxide emissions from wastewater treatment processes

    PubMed Central

    Law, Yingyu; Ye, Liu; Pan, Yuting; Yuan, Zhiguo

    2012-01-01

    Nitrous oxide (N2O) emissions from wastewater treatment plants vary substantially between plants, ranging from negligible to substantial (a few per cent of the total nitrogen load), probably because of different designs and operational conditions. In general, plants that achieve high levels of nitrogen removal emit less N2O, indicating that no compromise is required between high water quality and lower N2O emissions. N2O emissions primarily occur in aerated zones/compartments/periods owing to active stripping, and ammonia-oxidizing bacteria, rather than heterotrophic denitrifiers, are the main contributors. However, the detailed mechanisms remain to be fully elucidated, despite strong evidence suggesting that both nitrifier denitrification and the chemical breakdown of intermediates of hydroxylamine oxidation are probably involved. With increased understanding of the fundamental reactions responsible for N2O production in wastewater treatment systems and the conditions that stimulate their occurrence, reduction of N2O emissions from wastewater treatment systems through improved plant design and operation will be achieved in the near future. PMID:22451112

  17. Catalytic wet air oxidation of carboxylic acids on TiO{sub 2}-supported ruthenium catalysts

    SciTech Connect

    Beziat, J.C.; Besson, M.; Gallezot, P.; Durecu, S.

    1999-02-15

    The total oxidation of aqueous solutions of carboxylic acids by air was studied in a slurry reactor over the temperature range 180--100 C and oxygen partial pressure of 0.3--1.8 MPa in the presence of a 2.8%Ru/TiO{sub 2} catalyst. The influence of various parameters is presented: the catalytic wet air oxidation of succinic acid is 0 order with respect to succinic acid; the order with respect to oxygen pressure is 0.4, and the activation energy is ca. 125 kJ/mol. It was found that acetic acid, which is one of the intermediates, and CO{sub 2} have no retarding effect on the total organic carbon abatement rate of succinic acid. Substitution of one hydrogen atom of the methyl group in acetic acid by Cl, OH, or NH{sub 2} gives an increase of the oxidation rate. However, it was proposed that the low activity of acetic acid oxidation is due not only to the difficulty to oxidize the methyl group, but also to the low adsorption coefficient of acetic acid on ruthenium surface. Inorganic salts, such as sodium chloride, only slightly decrease the oxidation rate of acetic acid. The absence of metal ions (Ru, Ti) in the effluents after reaction and the absence of particle sintering indicate also a high stability of the catalyst under the conditions employed. The catalyst can be recycled without loss of activity after the second run. The activity becomes stable after the attainment of a steady-state coverage of the Ru particles by oxygen. The study of the effect of reduction-oxidation treatments of the catalyst showed that the activity depends on the oxidation state of the surface.

  18. Enrichment of amino acid-oxidizing, acetate-reducing bacteria.

    PubMed

    Ato, Makoto; Ishii, Masaharu; Igarashi, Yasuo

    2014-08-01

    In anaerobic condition, amino acids are oxidatively deaminated, and decarboxylated, resulting in the production of volatile fatty acids. In this process, excess electrons are produced and their consumption is necessary for the accomplishment of amino acid degradation. In this study, we anaerobically constructed leucine-degrading enrichment cultures from three different environmental samples (compost, excess sludge, and rice field soil) in order to investigate the diversity of electron-consuming reaction coupled to amino acid oxidation. Constructed enrichment cultures oxidized leucine to isovalerate and their activities were strongly dependent on acetate. Analysis of volatile fatty acids (VFAs) profiles and community structure analysis during batch culture of each enrichment indicated that Clostridium cluster I coupled leucine oxidation to acetate reduction in the enrichment from the compost and the rice field soil. In these cases, acetate was reduced to butyrate. On the other hand, Clostridium cluster XIVb coupled leucine oxidation to acetate reduction in the enrichment from the excess sludge. In this case, acetate was reduced to propionate. To our surprise, the enrichment from rice field soil oxidized leucine even in the absence of acetate and produced butyrate. The enrichment would couple leucine oxidation to reductive butyrate synthesis from CO2. The coupling reaction would be achieved based on trophic link between hydrogenotrophic acetogenic bacteria and acetate-reducing bacteria by sequential reduction of CO2 and acetate. Our study suggests anaerobic degradation of amino acids is achieved yet-to-be described reactions. PMID:24630616

  19. Chemical oxidation of phenolic acids by soil iron and manganese oxides

    SciTech Connect

    Lehmann, R.G.

    1986-01-01

    The oxidation of six phenolic acids by soil Fe and Mn oxides was demonstrated by changes in phenolic acid extractability from soil with time, by production of Fe(II) and soluble Mn from the oxidation reaction, by quantitative recoveries of added phenolic acids from soil pretreated with dithionite-citrate to remove Fe and Mn oxides, and by the reactivity of phenolic acids in the presence of pure Mn and Fe oxides. The reactivities of phenolic acids were associated with the structures of the chemicals. Increasing methoxy substitution on the aromatic ring increased reactivity, and cinnamic acid derivatives were more reactive than benzoic acid derivatives. Oxidation products of /sup 14/C labeled ferulic acid were sorbed to MnO/sub 2/ within minutes and were unextractable by organic solvents unless the mineral was pretreated with 6 M HCl or 0.5 M NaOH. The oxidation rate of ferulic acid by MnO/sub 2/ approached zero after four days even with a surplus of reactants.

  20. [Treatment of Petrochemical Treatment Plant Secondary Effluent by Fenton Oxidation].

    PubMed

    Wang, Yi; Wu, Chang-yong; Zhou, Yue-xi; Zhang, Xue; Dong, Bo; Chen, Xue-min

    2015-07-01

    Fenton oxidation was applied to treat the petrochemical treatment plant secondary effluent by the continuous flow configuration. The effect of Fenton agent dosage on the COD and phosphorus removal and the variation of the dissolved organic matter characteristics during the treatment process were investigated. The results showed the average COD and PO(4)3- -P concentrations were 64.8 mg.L-1 and 0. 79 mg.L-1, respectively. When the dosage of H2O (30%), FeSO4.7H2O and PAM were 0. 4 mL.L-1, 0. 8 mg.L-1 and 0. 9 mg.L-1 and the residence time was 30 min, the average removal rate of COD and PO(4)3- -P were 24. 3% and 95. 5% respectively. The effluent COD was lower than 50 mg.L-1. The percentage of dissolved organic matters with molecular weight less than 1 x 10(3) was 80. 4% in the raw wastewater, however, the percentage increased to 95. 6% when treated by Fenton oxidation. Three-dimensional fluorescence analysis showed that the Fenton oxidation can effectively remove protein and phenols. GC-MS results showed that there were about 117 kinds of organic matters detected in the secondary effluent, while the number reduced to 27 after oxidation by Fenton. The organics containing unsaturated bond had a better removal than those of other types of organics. Fenton oxidation can be used in the advanced treatment of petrochemical secondary effluent.

  1. 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.

  2. 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.

  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. 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.

  5. Bacterial Cyanuric Acid Hydrolase for Water Treatment

    PubMed Central

    Yeom, Sujin; Mutlu, Baris R.; Aksan, Alptekin

    2015-01-01

    Di- and trichloroisocyanuric acids are widely used as water disinfection agents, but cyanuric acid accumulates with repeated additions and must be removed to maintain free hypochlorite for disinfection. This study describes the development of methods for using a cyanuric acid-degrading enzyme contained within nonliving cells that were encapsulated within a porous silica matrix. Initially, three different bacterial cyanuric acid hydrolases were compared: TrzD from Acidovorax citrulli strain 12227, AtzD from Pseudomonas sp. strain ADP, and CAH from Moorella thermoacetica ATCC 39073. Each enzyme was expressed recombinantly in Escherichia coli and tested for cyanuric acid hydrolase activity using freely suspended or encapsulated cell formats. Cyanuric acid hydrolase activities differed by only a 2-fold range when comparing across the different enzymes with a given format. A practical water filtration system is most likely to be used with nonviable cells, and all cells were rendered nonviable by heat treatment at 70°C for 1 h. Only the CAH enzyme from the thermophile M. thermoacetica retained significant activity under those conditions, and so it was tested in a flowthrough system simulating a bioreactive pool filter. Starting with a cyanuric acid concentration of 10,000 μM, more than 70% of the cyanuric acid was degraded in 24 h, it was completely removed in 72 h, and a respike of 10,000 μM cyanuric acid a week later showed identical biodegradation kinetics. An experiment conducted with water obtained from municipal swimming pools showed the efficacy of the process, although cyanuric acid degradation rates decreased by 50% in the presence of 4.5 ppm hypochlorite. In total, these experiments demonstrated significant robustness of cyanuric acid hydrolase and the silica bead materials in remediation. PMID:26187963

  6. Bacterial Cyanuric Acid Hydrolase for Water Treatment.

    PubMed

    Yeom, Sujin; Mutlu, Baris R; Aksan, Alptekin; Wackett, Lawrence P

    2015-10-01

    Di- and trichloroisocyanuric acids are widely used as water disinfection agents, but cyanuric acid accumulates with repeated additions and must be removed to maintain free hypochlorite for disinfection. This study describes the development of methods for using a cyanuric acid-degrading enzyme contained within nonliving cells that were encapsulated within a porous silica matrix. Initially, three different bacterial cyanuric acid hydrolases were compared: TrzD from Acidovorax citrulli strain 12227, AtzD from Pseudomonas sp. strain ADP, and CAH from Moorella thermoacetica ATCC 39073. Each enzyme was expressed recombinantly in Escherichia coli and tested for cyanuric acid hydrolase activity using freely suspended or encapsulated cell formats. Cyanuric acid hydrolase activities differed by only a 2-fold range when comparing across the different enzymes with a given format. A practical water filtration system is most likely to be used with nonviable cells, and all cells were rendered nonviable by heat treatment at 70°C for 1 h. Only the CAH enzyme from the thermophile M. thermoacetica retained significant activity under those conditions, and so it was tested in a flowthrough system simulating a bioreactive pool filter. Starting with a cyanuric acid concentration of 10,000 μM, more than 70% of the cyanuric acid was degraded in 24 h, it was completely removed in 72 h, and a respike of 10,000 μM cyanuric acid a week later showed identical biodegradation kinetics. An experiment conducted with water obtained from municipal swimming pools showed the efficacy of the process, although cyanuric acid degradation rates decreased by 50% in the presence of 4.5 ppm hypochlorite. In total, these experiments demonstrated significant robustness of cyanuric acid hydrolase and the silica bead materials in remediation. PMID:26187963

  7. Bacterial Cyanuric Acid Hydrolase for Water Treatment.

    PubMed

    Yeom, Sujin; Mutlu, Baris R; Aksan, Alptekin; Wackett, Lawrence P

    2015-10-01

    Di- and trichloroisocyanuric acids are widely used as water disinfection agents, but cyanuric acid accumulates with repeated additions and must be removed to maintain free hypochlorite for disinfection. This study describes the development of methods for using a cyanuric acid-degrading enzyme contained within nonliving cells that were encapsulated within a porous silica matrix. Initially, three different bacterial cyanuric acid hydrolases were compared: TrzD from Acidovorax citrulli strain 12227, AtzD from Pseudomonas sp. strain ADP, and CAH from Moorella thermoacetica ATCC 39073. Each enzyme was expressed recombinantly in Escherichia coli and tested for cyanuric acid hydrolase activity using freely suspended or encapsulated cell formats. Cyanuric acid hydrolase activities differed by only a 2-fold range when comparing across the different enzymes with a given format. A practical water filtration system is most likely to be used with nonviable cells, and all cells were rendered nonviable by heat treatment at 70°C for 1 h. Only the CAH enzyme from the thermophile M. thermoacetica retained significant activity under those conditions, and so it was tested in a flowthrough system simulating a bioreactive pool filter. Starting with a cyanuric acid concentration of 10,000 μM, more than 70% of the cyanuric acid was degraded in 24 h, it was completely removed in 72 h, and a respike of 10,000 μM cyanuric acid a week later showed identical biodegradation kinetics. An experiment conducted with water obtained from municipal swimming pools showed the efficacy of the process, although cyanuric acid degradation rates decreased by 50% in the presence of 4.5 ppm hypochlorite. In total, these experiments demonstrated significant robustness of cyanuric acid hydrolase and the silica bead materials in remediation.

  8. Precipitation of plutonium from acidic solutions using magnesium oxide

    SciTech Connect

    Jones, S.A.

    1994-12-05

    Magnesium oxide will be used as a neutralizing agent for acidic plutonium-containing solutions. It is expected that as the magnesium oxide dissolves, the pH of the solution will rise, and plutonium will precipitate. The resulting solid will be tested for suitability to storage. The liquid is expected to contain plutonium levels that meet disposal limit requirements.

  9. 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

  10. 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

  11. 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.

  12. 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…

  13. Recovery of iron oxides from acid mine drainage and their application as adsorbent or catalyst.

    PubMed

    Flores, Rubia Gomes; Andersen, Silvia Layara Floriani; Maia, Leonardo Kenji Komay; José, Humberto Jorge; Moreira, Regina de Fatima Peralta Muniz

    2012-11-30

    Iron oxide particles recovered from acid mine drainage represent a potential low-cost feedstock to replace reagent-grade chemicals in the production of goethite, ferrihydrite or magnetite with relatively high purity. Also, the properties of iron oxides recovered from acid mine drainage mean that they can be exploited as catalysts and/or adsorbents to remove azo dyes from aqueous solutions. The main aim of this study was to recover iron oxides with relatively high purity from acid mine drainage to act as a catalyst in the oxidation of dye through a Fenton-like mechanism or as an adsorbent to remove dyes from an aqueous solution. Iron oxides (goethite) were recovered from acid mine drainage through a sequential precipitation method. Thermal treatment at temperatures higher than 300 °C produces hematite through a decrease in the BET area and an increase in the point of zero charge. In the absence of hydrogen peroxide, the solids adsorbed the textile dye Procion Red H-E7B according to the Langmuir model, and the maximum amount adsorbed decreased as the temperature of the thermal treatment increased. The decomposition kinetics of hydrogen peroxide is dependent on the H(2)O(2) concentration and iron oxides dosage, but the second-order rate constant normalized to the BET surface area is similar to that for different iron oxides tested in this and others studies. These results indicate that acid mine drainage could be used as a source material for the production of iron oxide catalysts/adsorbents, with comparable quality to those produced using analytical-grade reagents.

  14. A review of wet air oxidation and Thermal Hydrolysis technologies in sludge treatment.

    PubMed

    Hii, Kevin; Baroutian, Saeid; Parthasarathy, Raj; Gapes, Daniel J; Eshtiaghi, Nicky

    2014-03-01

    With rapid world population growth and strict environmental regulations, increasingly large volumes of sludge are being produced in today's wastewater treatment plants (WWTP) with limited disposal routes. Sludge treatment has become an essential process in WWTP, representing 50% of operational costs. Sludge destruction and resource recovery technologies are therefore of great ongoing interest. Hydrothermal processing uses unique characteristics of water at elevated temperatures and pressures to deconstruct organic and inorganic components of sludge. It can be broadly categorized into wet oxidation (oxidative) and thermal hydrolysis (non-oxidative). While wet air oxidation (WAO) can be used for the final sludge destruction and also potentially producing industrially useful by-products such as acetic acid, thermal hydrolysis (TH) is mainly used as a pre-treatment method to improve the efficiency of anaerobic digestion. This paper reviews current hydrothermal technologies, roles of wet air oxidation and thermal hydrolysis in sludge treatment, and challenges faced by these technologies.

  15. Amelioration of cyclophosphamide induced myelosuppression and oxidative stress by cinnamic acid.

    PubMed

    Patra, Kartick; Bose, Samadrita; Sarkar, Shehnaz; Rakshit, Jyotirmoy; Jana, Samarjit; Mukherjee, Avik; Roy, Abhishek; Mandal, Deba Prasad; Bhattacharjee, Shamee

    2012-02-01

    Cinnamic acid (C9H8O2), is a major constituent of the oriental Ayurvedic plant Cinnamomum cassia (Family: Lauraceae). This phenolic acid has been reported to possess various pharmacological properties of which its antioxidant activity is a prime one. Therefore it is rational to hypothesize that it may ameliorate myelosuppression and oxidative stress induced by cyclophosphamide, a widely used chemotherapeutic agent. Commercial cyclophosphamide, Endoxan, was administered intraperitoneally to Swiss albino mice (50mg/kg) pretreated with 15, 30 and 60mg/kg doses of cinnamic acid orally at alternate days for 15days. Cinnamic acid pre-treatment was found to reduce cyclophosphamide induced hypocellularity in the bone marrow and spleen. This recovery was also reflected in the peripheral blood count. Amelioration of hypocellularity could be correlated with the modulation of cell cycle phase distribution. Cinnamic acid pre-treatment reduced bone marrow and hepatic oxidative stress as evident by lipid peroxidation and activity assays of antioxidant enzymes such as superoxide dismutase, catalase and glutathione-S-transferase. The present study indicates that cinnamic acid pretreatment has protective influence on the myelosuppression and oxidative stress induced by cyclophosphamide. This investigation is an attempt and is the first of its kind to establish cinnamic acid as an agent whose consumption provides protection to normal cells from the toxic effects of a widely used anti-cancer drug.

  16. Lipid oxidation stability of omega-3- and conjugated linoleic acid-enriched sous vide chicken meat.

    PubMed

    Narciso-Gaytán, C; Shin, D; Sams, A R; Keeton, J T; Miller, R K; Smith, S B; Sánchez-Plata, M X

    2011-02-01

    Lipid oxidation is known to occur rather rapidly in cooked chicken meat containing relatively high amounts of polyunsaturated fatty acids. To assess the lipid oxidation stability of sous vide chicken meat enriched with n-3 and conjugated linoleic acid (CLA) fatty acids, 624 Cobb × Ross broilers were raised during a 6-wk feeding period. The birds were fed diets containing CLA (50% cis-9, trans-11 and 50% trans-10, cis-12 isomers), flaxseed oil (FSO), or menhaden fish oil (MFO), each supplemented with 42 or 200 mg/kg of vitamin E (dl-α-tocopheryl acetate). Breast or thigh meat was vacuum-packed, cooked (74°C), cooled in ice water, and stored at 4.4°C for 0, 5, 10, 15, and 30 d. The lipid oxidation development of the meat was estimated by quantification of malonaldehyde (MDA) values, using the 2-thiobarbituric acid reactive substances analysis. Fatty acid, nonheme iron, moisture, and fat analyses were performed as well. Results showed that dietary CLA induced deposition of cis-9, trans-11 and trans-10, cis-12 CLA isomers, increased the proportion of saturated fatty acids, and decreased the proportions of monounsaturated and polyunsaturated fatty acids. Flaxseed oil induced higher deposition of C18:1, C18:2, C18:3, and C20:4 fatty acids, whereas MFO induced higher deposition of n-3 fatty acids, eicosapentaenoic acid (C20:5), and docosahexaenoic acid (C22:6; P < 0.05). Meat lipid oxidation stability was affected by the interaction of either dietary oil or vitamin E with storage day. Lower (P < 0.05) MDA values were found in the CLA treatment than in the MFO and FSO treatments. Lower (P < 0.05) MDA values were detected in meat samples from the 200 mg/kg of vitamin E than in meat samples from the 42 mg/kg of vitamin E. Nonheme iron values did not affect (P > 0.05) lipid oxidation development. In conclusion, dietary CLA, FSO, and MFO influenced the fatty acid composition of chicken muscle and the lipid oxidation stability of meat over the storage time. Supranutritional

  17. Lipid oxidation stability of omega-3- and conjugated linoleic acid-enriched sous vide chicken meat.

    PubMed

    Narciso-Gaytán, C; Shin, D; Sams, A R; Keeton, J T; Miller, R K; Smith, S B; Sánchez-Plata, M X

    2011-02-01

    Lipid oxidation is known to occur rather rapidly in cooked chicken meat containing relatively high amounts of polyunsaturated fatty acids. To assess the lipid oxidation stability of sous vide chicken meat enriched with n-3 and conjugated linoleic acid (CLA) fatty acids, 624 Cobb × Ross broilers were raised during a 6-wk feeding period. The birds were fed diets containing CLA (50% cis-9, trans-11 and 50% trans-10, cis-12 isomers), flaxseed oil (FSO), or menhaden fish oil (MFO), each supplemented with 42 or 200 mg/kg of vitamin E (dl-α-tocopheryl acetate). Breast or thigh meat was vacuum-packed, cooked (74°C), cooled in ice water, and stored at 4.4°C for 0, 5, 10, 15, and 30 d. The lipid oxidation development of the meat was estimated by quantification of malonaldehyde (MDA) values, using the 2-thiobarbituric acid reactive substances analysis. Fatty acid, nonheme iron, moisture, and fat analyses were performed as well. Results showed that dietary CLA induced deposition of cis-9, trans-11 and trans-10, cis-12 CLA isomers, increased the proportion of saturated fatty acids, and decreased the proportions of monounsaturated and polyunsaturated fatty acids. Flaxseed oil induced higher deposition of C18:1, C18:2, C18:3, and C20:4 fatty acids, whereas MFO induced higher deposition of n-3 fatty acids, eicosapentaenoic acid (C20:5), and docosahexaenoic acid (C22:6; P < 0.05). Meat lipid oxidation stability was affected by the interaction of either dietary oil or vitamin E with storage day. Lower (P < 0.05) MDA values were found in the CLA treatment than in the MFO and FSO treatments. Lower (P < 0.05) MDA values were detected in meat samples from the 200 mg/kg of vitamin E than in meat samples from the 42 mg/kg of vitamin E. Nonheme iron values did not affect (P > 0.05) lipid oxidation development. In conclusion, dietary CLA, FSO, and MFO influenced the fatty acid composition of chicken muscle and the lipid oxidation stability of meat over the storage time. Supranutritional

  18. 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.

  19. DEMONSTRATION BULLETIN: PEROX-PURE CHEMICAL OXIDATION TREATMENT

    EPA Science Inventory

    Technology Description: The perox-pure™ chemical oxidation treatment technology was developed by Peroxidation Systems, Inc. (PSI), to destroy dissolved organic contaminants in water. The technology uses ultraviolet (UV) radiation and hydrogen peroxide to oxidize organic co...

  20. Retinol oxidation to retinoic acid in human thyroid glandular cells.

    PubMed

    Taibi, Gennaro; Gueli, Maria Concetta; Nicotra, Concetta M A; Cocciadiferro, Letizia; Carruba, Giuseppe

    2014-12-01

    Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its ability to oxidize xanthine to uric acid and its sensitivity to the inhibitory effect of oxypurinol. The evidence of XDH-driven formation of retinoic acid in HTGC cultures further corroborates the potential role of XDH in retinoic acid biosynthesis in the epithelia. PMID:24506204

  1. Melatonin protects against oxidative stress caused by delta-aminolevulinic acid: implications for cancer reduction.

    PubMed

    Karbownik, Małgorzata; Reiter, Russel J

    2002-01-01

    delta-Aminolevulinic acid (ALA) is a precursor of haem. The increased concentration of ALA is typically related to acute intermittent porphyria, hereditary tyrosinemia, and lead poisoning. delta-Aminolevulinic acid produced in excess accumulates in a number of organs, causes oxidative damage, and often leads to cancer. Melatonin (N-acetyl-5-methoxytryptamine) is a well-known antioxidant, free radical scavenger, and exhibits anticarcinogenic properties. It protects DNA, lipids, and proteins from oxidative damage. The protective effects of melatonin against ALA-induced oxidation of guanine bases, lipid peroxidation, and alterations in membrane fluidity in several organs have been documented. There is an inverse relationship between melatonin and ALA concentrations in both experimental and clinical conditions of porphyria. The marked efficacy of melatonin in protecting against ALA-related oxidative stress, its oncostatic properties, and low toxicity constitute reasons to consider the use of this indoleamine as a co-treatment in patients suffering from disturbances related to ALA accumulation.

  2. Acidic properties of oxides containing niobia on silica and niobia in silica

    SciTech Connect

    Burke, P.A.; Ko E.I. )

    1991-05-01

    A series of composite oxides containing niobia (Nb{sub 2}O{sub 5}) and silica (SiO{sub 2}) was prepared by either incipient wetness impregnation to form surface phase oxides or by coprecipitation to form mixed oxides. At low Nb{sub 2}O{sub 5} concentrations, both the surface phase and mixed oxides showed strong Lewis acidity as determined by thermogravimetric and infrared studies of adsorbed pyridine. A surface phase oxide containing 0.25 monolayer of Nb{sub 2}O{sub 5} on SiO{sub 2} further showed strong Broensted acidity. With increasing Nb{sub 2}O{sub 5} concentration and/or treatment temperature, Nb{sub 2}O{sub 5} in these composite oxides became more bulk-like and showed a corresponding decrease in acid strength. These acidic properties are discussed in terms of proposed structural models which contain tetrahedral niobia, octahedral niobia, and Nb=O bonds as basic building blocks.

  3. Induction of carnitine palmitoyl transferase 1 and fatty acid oxidation by retinoic acid in HepG2 cells.

    PubMed

    Amengual, Jaume; Petrov, Petar; Bonet, M Luisa; Ribot, Joan; Palou, Andreu

    2012-11-01

    The vitamin A derivative retinoic acid (RA) is an important regulator of mammalian adiposity and lipid metabolism, primarily acting at the gene expression level through nuclear receptors of the RA receptor (RAR) and retinoid X receptor (RXR) subfamilies. Here, we studied cell-autonomous effects of RA on fatty acid metabolism, particularly fatty acid oxidation, in human hepatoma HepG2 cells. Exposure to all-trans RA (ATRA) up-regulated the expression of carnitine palmitoyl transferase-1 (CPT1-L) in HepG2 cells in a dose- and time-dependent manner, and increased cellular oxidation rate of exogenously added radiolabeled palmitate. The effect of ATRA on gene expression of CPT1-L was: dependent on ongoing transcription, reproduced by both 9-cis RA and a pan-RXR agonist (but not a pan-RAR agonist) and abolished following RXRα partial siRNA-mediated silencing. CPT1-L gene expression was synergistically induced in HepG2 cells simultaneously exposed to ATRA and a selective peroxisome proliferator-activated receptor α agonist. We conclude that ATRA treatment enhances fatty acid catabolism in hepatocytes through RXR-mediated mechanisms that likely involve the transactivation of the PPARα:RXR heterodimer. Knowledge of agents and nutrient-derivatives capable of enhancing substrate oxidation systemically and specifically in liver, and their mechanisms of action, may contribute to new avenues of prevention and treatment of fatty liver, obesity and other metabolic syndrome-related disorders. PMID:22871568

  4. A comparative study of stearic and lignoceric acid oxidation by human skin fibroblasts.

    PubMed

    Singh, H; Poulos, A

    1986-10-01

    Sensitive assays were developed for long chain and very long chain fatty acid oxidation in human skin fibroblast homogenates. Stearic and lignoceric acids were degraded by the fibroblasts by the beta-oxidation pathway. The cofactor requirements for stearic and lignoceric acid beta-oxidation were very similar but not identical. For example, appreciable lignoceric acid oxidation could be demonstrated only in the presence of alpha-cyclodextrin and was inhibited by Triton X-100. In Zellweger's syndrome, stearic acid beta-oxidation was partially reduced whereas lignoceric acid beta-oxidation was reduced dramatically (less than 12% activity compared to the controls). The results presented suggest that stearic acid beta-oxidation occurs in mitochondria as well as in peroxisomes, but lignoceric acid oxidation occurs entirely in the peroxisomes. We suggest that the beta-oxidation systems for stearic acid and lignoceric acid may be different.

  5. Chemoselective Conversion from α-Hydroxy Acids to α-Keto Acids Enabled by Nitroxyl-Radical-Catalyzed Aerobic Oxidation.

    PubMed

    Furukawa, Keisuke; Inada, Haruki; Shibuya, Masatoshi; Yamamoto, Yoshihiko

    2016-09-01

    The chemoselective oxidation of α-hydroxy acids to α-keto acids catalyzed by 2-azaadamantane N-oxyl (AZADO), a nitroxyl radical catalyst, is described. Although α-keto acids are labile and can easily release CO2 under oxidation conditions, the use of molecular oxygen as a cooxidant enables the desired chemoselective oxidation. PMID:27533283

  6. Protective effects of gallic acid against spinal cord injury-induced oxidative stress.

    PubMed

    Yang, Yong Hong; Wang, Zao; Zheng, Jie; Wang, Ran

    2015-08-01

    The present study aimed to investigate the role of gallic acid in oxidative stress induced during spinal cord injury (SCI). In order to measure oxidative stress, the levels of lipid peroxide, protein carbonyl, reactive oxygen species and nitrates/nitrites were determined. In addition, the antioxidant status during SCI injury and the protective role of gallic acid were investigated by determining glutathione levels as well as the activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione-S-transferase. Adenosine triphophatase (ATPase) enzyme activities were determined to evaluate the role of gallic acid in SCI-induced deregulation of the activity of enzymes involved in ion homeostasis. The levels of inflammatory markers such as nuclear factor (NF)-κB and cycloxygenase (COX)-2 were determined by western blot analysis. Treatment with gallic acid was observed to significantly mitigate SCI-induced oxidative stress and the inflammatory response by reducing the oxidative stress, decreasing the expression of NF-κB and COX-2 as well as increasing the antioxidant status of cells. In addition, gallic acid modulated the activity of ATPase enzymes. Thus the present study indicated that gallic acid may have a role as a potent antioxidant and anti-inflammatory agent against SCI.

  7. Advanced oxidation treatment of physico-chemically pre-treated olive mill industry effluent.

    PubMed

    Gomec, Cigdem Y; Erdim, Esra; Turan, Ilknur; Aydin, Ali F; Ozturk, Izzet

    2007-08-01

    In this study, the applicability of physico-chemical methods was investigated for the pre-treatment of the olive mill effluents prior to the discharge into the common sewerage ending with a municipal wastewater treatment plant. The samples were taken from an olive oil industry operated as three-phase process located in Turkey. Various pre-treatment methods including acid craking, polyelectrolyte and lime additions were applied. Advanced oxidation study using Fenton's process was also investigated following pre-treatment by acid cracking and cationic polyelectrolyte. Acid cracking alone gave satisfactory treatment efficiencies and polyelectrolite additions to the acid-cracked samples enhanced treatment efficiency. Since a complete treatment plant is available at the end of the sewer system, results indicated that the effluents of the investigated industry could be discharged into the municipal sewerage in the case of total chemical oxygen demand (COD(tot)), suspended solid (SS) and volatile suspended solid (VSS) concentrations according to the Turkish Water Pollution Control Regulation after pre-treatment with 5 ppm anionic polyelectrolyte following acid cracking. The minimum COD(tot), SS and VSS removals were observed when raw wastewater was pre-treated with lime and the discharge standards to the municipal sewer system could not be met. Advanced oxidation with Fenton's process was applied after acid cracking and cationic polyelectrolyte treatment in order to investigate further reduction in chemical oxygen demand (COD) concentration for minimizing the influence of this industrial discharge on the existing municipal wastewater treatment plant. Results indicated that COD(tot) removal increased up to 89% from 74% after Fenton's oxidation for the acid cracked samples in which cationic polyelectrolite (10 ppm) was added.

  8. 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.

  9. Low-molecular-weight carboxylic acids produced from hydrothermal treatment of organic wastes.

    PubMed

    Quitain, Armando T; Faisal, Muhammad; Kang, Kilyoon; Daimon, Hiroyuki; Fujie, Koichi

    2002-07-22

    This article reports production of low-molecular-weight carboxylic acids from the hydrothermal treatment of representative organic wastes and compounds (i.e. domestic sludge, proteinaceous, cellulosic and plastic wastes) with or without oxidant (H(2)O(2)). Organic acids such as acetic, formic, propionic, succinic and lactic acids were obtained in significant amounts. At 623 K (16.5 MPa), acetic acid of about 26 mg/g dry waste fish entrails was obtained. This increased to 42 mg/g dry waste fish entrails in the presence of H(2)O(2). Experiments on glucose to represent cellulosic wastes were also carried out, getting acetic acid of about 29 mg/g glucose. The study was extended to terephthalic acid and glyceraldehyde, reaction intermediates of hydrothermal treatment of polyethylene terephthalate (PET) plastic wastes and glucose, respectively. In addition, production of lactic acid, one of the interesting low-molecular-weight carboxylic acids, was discussed on the viewpoint of resources recovery. Studies on temperature dependence of formation of organic acids showed thermal stability of acetic acid, whereas, formic acid decomposed readily under hydrothermal conditions. In general, results demonstrated that the presence of oxidants favored formation of organic acids with acetic acid being the major product.

  10. Effect of Acid Oxidation on the Dispersion Property of Multiwalled Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Goh, P. S.; Ismail, A. F.; Aziz, M.

    2009-06-01

    A means of dispersion of multiwalled carbon nanotube (MWCNT) via mixed acid (HNO3 and H2SO4) oxidation with different treatment durations was investigated through the solubility study of the treated carbon nanotubes in some common solvents. Fourier transformed infrared (FTIR) characterization of the reaction products revealed that the surface of MWCNTs was successfully functionalized with surface acidic groups. The acid-base titration demonstrated that the amount of surface acidic groups increased in parallel with the refluxing duration. The acid modified MWCNTs were found to be well dispersed in polar solvents, such as ethanol and water due to the presence of the hydrophilic acid functional groups on the surface of raw MWCNTs. Such chemical modification of carbon nanotube properties will pave the way towards the realistic applications in the nanotechnology world.

  11. 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.

  12. Cilostazol induces mitochondrial fatty acid β-oxidation in C2C12 myotubes.

    PubMed

    Wang, Bo; Zhu, Liping; Sui, Shaohua; Sun, Caixia; Jiang, Haiping; Ren, Donghui

    2014-05-01

    Cilostazol is a drug licensed for the treatment of intermittent claudication. Its main action is to elevate intracellular levels of cyclic monophosphate (cAMP) by inhibiting the activity of type III phosphodiesterase, a cAMP-degrading enzyme. The effects of cilostazol on fatty acid oxidation (FAO) are as yet unknown. In this study, we report that cilostazol can elevate complete FAO and decrease both triacylglycerol (TAG) accumulation and TAG secretion. This use of cilostazol treatment increases expression of PGC-1α and, subsequently, its target genes, such as ERRα, NOR1, CD36, CPT1, MCAD, and ACO. Expression of these factors is linked to fatty acid β-oxidation but this effect is inhibited by H-89, a specific inhibitor of the PKA/CREB pathway. Importantly, knockdown of PGC-1α using siRNA abolished the effects of cilostazol in fatty acid oxidation (FAO) and TAG metabolism. These findings suggested that the PKA/CREB/PGC-1α pathway plays a critical role in cilostazol-induced fatty acid oxidation and TAG metabolism.

  13. Fatty Acid Oxidation by Spores of Penicillium roqueforti

    PubMed Central

    Gehrig, R. F.; Knight, S. G.

    1963-01-01

    When 1 μm sodium octanoate was the substrate for spores, most of the molecule was recovered as CO2 and no ketone was produced. However, when larger concentrations (20 μm) were used as substrate, part of the molecule was converted to methyl ketone and part was completely oxidized. Optimal conditions for the production of 2-heptanone were determined because of the importance of this compound in giving aroma and flavor to mold-ripened cheeses. Optimal ketone formation was not dependent upon the temperature and length of time at which the spores were stored. The spore suspensions were stored for over 36 months at 4 C without losing their ability to convert octanoic acid to 2-heptanone. The oxidation of octanoic acid was inhibited by cyanide, carbon monoxide, mercury, 2,3-dimercapto-1-propanol, and α, α-dipyridyl. No ketone was produced under anaerobic conditions. Although no intermediates of fatty acid oxidation were isolated, since an active cell-free preparation could not be obtained, this investigation has yielded some evidence for the beta oxidation of the fatty acids by spores of Penicillium roqueforti. PMID:13947000

  14. Profiling protein thiol oxidation in tumor cells using sulfenic acid-specific antibodies.

    PubMed

    Seo, Young Ho; Carroll, Kate S

    2009-09-22

    Hydrogen peroxide (H2O2) functions as a second messenger that can activate cell proliferation through chemoselective oxidation of cysteine residues in signaling proteins. The connection between H2O2 signaling, thiol oxidation, and activation of growth pathways has emerged as fertile ground for the development of strategies for cancer treatment. Central to achieving this goal is the development of tools and assays that facilitate characterization of the molecular events associated with tumorigenesis and evaluation of patient response to therapy. Here we report on the development of an immunochemical method for detecting sulfenic acid, the initial oxidation product that results when a thiolate reacts with H2O2. For this approach, the sulfenic acid is derivatized with a chemical tag to generate a unique epitope for recognition. The elicited antibody is exquisitely specific, context-independent, and capable of visualizing sulfenic acid formation in cells. Applying this approach to several systems, including cancer cell lines, shows it can be used to monitor differences in thiol redox status and reveals a diverse pattern of sulfenic acid modifications across different subtypes of breast tumors. These studies demonstrate a general strategy for producing antibodies against a specific oxidation state of cysteine and show the utility of these reagents for profiling thiol oxidation associated with pathological conditions such as breast cancer.

  15. Role of ellagic acid against cisplatin-induced nephrotoxicity and oxidative stress in rats.

    PubMed

    Ateşşahín, Ahmet; Ceríbaşi, Ali Osman; Yuce, Abdurrauf; Bulmus, Ozgür; Cikim, Gürkan

    2007-02-01

    The aim of this study was to investigate the possible protective role of antioxidant treatment with ellagic acid on cisplatin-induced nephrotoxicity using biochemical and histopatological approaches. Adult male Sprague-Dawley rats were randomly divided into four groups. The control group received 0.9% saline; animals in the ellagic acid group received only ellagic acid (10 mg/kg); animals in the cisplatin group received only cisplatin (7 mg/kg); animals in the cisplatin + ellagic acid group received ellagic acid for 10 days after cisplatin. The effects of ellagic acid on cisplatin-induced nephrotoxicity were evaluated by plasma creatinine, urea, sodium and calcium concentrations; kidney tissue malondialdehyde, reduced glutathione (GSH), glutathione peroxidase (GSH peroxidase) and catalase activities and histopatological examinations. Administration of cisplatin to rats induced a marked renal failure, characterized by significant increases in plasma creatinine, urea and calcium concentrations. Cisplatin also induced oxidative stress, as indicated by increased kidney tissue concentrations of malondialdehyde, and reduced activities of GSH peroxidase and catalase. Furthermore, treatment with cisplatin caused a marked tubular necrosis, degeneration and desquamation, luminal cast formation, karyomegaly, tubular dilatation, interstitial mononuclear cell infiltration and inter-tubular haemorrhagia. Ellagic acid markedly reduced elevated plasma creatinine, urea and calcium levels and counteracted the deleterious effects of cisplatin on oxidative stress markers. In the same way, ellagic acid ameliorated cisplatin-induced pathological changes including tubular necrosis, degeneration, karyomegaly, tubular dilatation when compared to the cisplatin alone group. These results indicate that the antioxidant ellagic acid might have a protective effect against cisplatin-induced nephrotoxicity and oxidative stress in rat, but not enough to inhibit cisplatin-induced renal dysfunction.

  16. 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

  17. Characterization of oxide coatings formed on tantalum by plasma electrolytic oxidation in 12-tungstosilicic acid

    NASA Astrophysics Data System (ADS)

    Petković, M.; Stojadinović, S.; Vasilić, R.; Zeković, Lj.

    2011-10-01

    Oxide coatings were formed on tantalum by plasma electrolytic oxidation (PEO) process in 12-tungstosilicic acid. The PEO process can be divided into three stages with respect to change of the voltage-time response. The contribution of electron current density in total current density during anodization results in the transformation of the slope of voltage-time curve. The surface morphology, chemical and phase composition of oxide coatings were investigated by AFM, SEM-EDX, XRD and Raman spectroscopy. Oxide coating morphology is strongly dependent of PEO time. The elemental components of PEO coatings are Ta, O, Si and W. The oxide coatings are partly crystallized and mainly composed of WO 3, Ta 2O 5 and SiO 2. Raman spectroscopy showed that the outer layer of oxide coatings formed during the PEO process is silicate tungsten bronze.

  18. Arachidonic acid-induced oxidative injury to cultured spinal cord neurons.

    PubMed

    Toborek, M; Malecki, A; Garrido, R; Mattson, M P; Hennig, B; Young, B

    1999-08-01

    Spinal cord trauma can cause a marked release of free fatty acids, in particular, arachidonic acid (AA), from cell membranes. Free fatty acids, and AA by itself, may lead to secondary damage to spinal cord neurons. To study this hypothesis, cultured spinal cord neurons were exposed to increasing concentrations of AA (0.01-10 microM). AA-induced injury to spinal cord neurons was assessed by measurements of cellular oxidative stress, intracellular calcium levels, activation of nuclear factor-KB (NF-kappaB), and cell viability. AA treatment increased intracellular calcium concentrations and decreased cell viability. Oxidative stress increased significantly in neurons exposed to 1 and 10 microM AA. In addition, AA treatment activated NF-kappaB and decreased levels of the inhibitory subunit, IKB. It is interesting that manganese superoxide dismutase protein levels and levels of intracellular total glutathione increased in neurons exposed to this fatty acid for 24 h, consistent with a compensatory response to increased oxidative stress. These results strongly support the hypothesis that free fatty acids contribute to the tissue injury observed following spinal cord trauma. PMID:10428065

  19. Nucleic acid oxidation: an early feature of Alzheimer's disease.

    PubMed

    Bradley-Whitman, Melissa A; Timmons, Michael D; Beckett, Tina L; Murphy, Michael P; Lynn, Bert C; Lovell, Mark A

    2014-01-01

    Studies of oxidative damage during the progression of Alzheimer's disease (AD) suggest its central role in disease pathogenesis. To investigate levels of nucleic acid oxidation in both early and late stages of AD, levels of multiple base adducts were quantified in nuclear and mitochondrial DNA from the superior and middle temporal gyri (SMTG), inferior parietal lobule (IPL), and cerebellum (CER) of age-matched normal control subjects, subjects with mild cognitive impairment, preclinical AD, late-stage AD, and non-AD neurological disorders (diseased control; DC) using gas chromatography/mass spectrometry. Median levels of multiple DNA adducts in nuclear and mitochondrial DNA were significantly (p ≤ 0.05) elevated in the SMTG, IPL, and CER in multiple stages of AD and in DC subjects. Elevated levels of fapyguanine and fapyadenine in mitochondrial DNA suggest a hypoxic environment early in the progression of AD and in DC subjects. Overall, these data suggest that oxidative damage is an early event not only in the pathogenesis of AD but is also present in neurodegenerative diseases in general. Levels of oxidized nucleic acids in nDNA and mtDNA were found to be significantly elevated in mild cognitive impairment (MCI), preclinical Alzheimer's disease (PCAD), late-stage AD (LAD), and a pooled diseased control group (DC) of frontotemporal dementia (FTD) and dementia with Lewy bodies (DLB) subjects compared to normal control (NC) subjects. Nucleic acid oxidation peaked early in disease progression and remained elevated. The study suggests nucleic acid oxidation is a general event in neurodegeneration.

  20. 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.

  1. 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

  2. Lipidomic profiling reveals protective function of fatty acid oxidation in cocaine-induced hepatotoxicity[S

    PubMed Central

    Shi, Xiaolei; Yao, Dan; Gosnell, Blake A.; Chen, Chi

    2012-01-01

    During cocaine-induced hepatotoxicity, lipid accumulation occurs prior to necrotic cell death in the liver. However, the exact influences of cocaine on the homeostasis of lipid metabolism remain largely unknown. In this study, the progression of subacute hepatotoxicity, including centrilobular necrosis in the liver and elevation of transaminase activity in serum, was observed in a three-day cocaine treatment, accompanying the disruption of triacylglycerol (TAG) turnover. Serum TAG level increased on day 1 of cocaine treatment but remained unchanged afterwards. In contrast, hepatic TAG level was elevated continuously during three days of cocaine treatment and was better correlated with the development of hepatotoxicity. Lipidomic analyses of serum and liver samples revealed time-dependent separation of the control and cocaine-treated mice in multivariate models, which was due to the accumulation of long-chain acylcarnitines together with the disturbances of many bioactive phospholipid species in the cocaine-treated mice. An in vitro function assay confirmed the progressive inhibition of mitochondrial fatty acid oxidation after the cocaine treatment. Cotreatment of fenofibrate significantly increased the expression of peroxisome proliferator-activated receptor α (PPARα)-targeted genes and the mitochondrial fatty acid oxidation activity in the cocaine-treated mice, resulting in the inhibition of cocaine-induced acylcarnitine accumulation and other hepatotoxic effects. Overall, the results from this lipidomics-guided study revealed that the inhibition of fatty acid oxidation plays an important role in cocaine-induced liver injury. PMID:22904346

  3. 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

  4. 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.

  5. Towards energy positive wastewater treatment by sludge treatment using free nitrous acid.

    PubMed

    Wang, Qilin; Hao, Xiaodi; Yuan, Zhiguo

    2016-02-01

    Free nitrous acid (FNA i.e. HNO2) was revealed to be effective in enhancing biodegradability of secondary sludge. Also, nitrite-oxidizing bacteria were found to be more susceptible to FNA than ammonium-oxidizing bacteria. Based on these findings, a novel FNA-based sludge treatment technology is proposed to enhance energy recovery from wastewater/sludge. Energy analysis indicated that the FNA-based technology would make wastewater treatment become an energy generating process (yielding energy at 4 kWh/PE/y; kWh/PE/y: kilowatt hours per population equivalent per year), rather than being a large energy consumer that it is today (consuming energy at 24 kWh/PE/y). Importantly, FNA required for the sludge treatment could be produced as a by-product of wastewater treatment. This proposed FNA-based technology is economically and environmentally attractive, and can be easily implemented in any wastewater treatment plants. It only involves the installation of a simple sludge mixing tank. This article presents the concept of the FNA-based technology.

  6. Towards energy positive wastewater treatment by sludge treatment using free nitrous acid.

    PubMed

    Wang, Qilin; Hao, Xiaodi; Yuan, Zhiguo

    2016-02-01

    Free nitrous acid (FNA i.e. HNO2) was revealed to be effective in enhancing biodegradability of secondary sludge. Also, nitrite-oxidizing bacteria were found to be more susceptible to FNA than ammonium-oxidizing bacteria. Based on these findings, a novel FNA-based sludge treatment technology is proposed to enhance energy recovery from wastewater/sludge. Energy analysis indicated that the FNA-based technology would make wastewater treatment become an energy generating process (yielding energy at 4 kWh/PE/y; kWh/PE/y: kilowatt hours per population equivalent per year), rather than being a large energy consumer that it is today (consuming energy at 24 kWh/PE/y). Importantly, FNA required for the sludge treatment could be produced as a by-product of wastewater treatment. This proposed FNA-based technology is economically and environmentally attractive, and can be easily implemented in any wastewater treatment plants. It only involves the installation of a simple sludge mixing tank. This article presents the concept of the FNA-based technology. PMID:26539712

  7. Microwave treatment of naphthenic acids in water.

    PubMed

    Mishra, Sabyasachi; Meda, Venkatesh; Dalai, Ajay K; Headley, John V; Peru, Kerry M; McMartin, Dena W

    2010-08-01

    Naphthenic acids (NAs) are natural constituents of bitumen and crude oil. These compounds are concentrated as part of the oil sands process water (OSPW) during petroleum refining and separation from oil sands. NAs are considered among the major water contaminants in OSPW due to their toxicity and environmental recalcitrance. A laboratory scale microwave system was developed and experiments were conducted to determine the efficiency of NA degradation during microwave treatment. The effects of water source and quality (deionized lab water and river water) and of TiO(2) catalyst in the degradation process were also investigated. Degradation kinetic parameters for both total NAs and individual z-family were calculated. The microwave system degraded OSPW NAs and commercial Fluka NAs in river water in the presence of TiO(2) rapidly, producing half-life values of 3.32 and 3.61 hours, respectively. Toxicity assessments of the NA samples pre-and post-treatment indicated that the microwave system reduced overall toxicity of water containing Fluka NAs from high (5 min. IC(50) v/v = 15.85%) to moderate (5 min. IC(50) v/v = 36.45%) toxicity levels. However, a slight increase in toxicity was noted post-treatment in OSPW NAs.

  8. Treatment of trichlorophenol by catalytic oxidation process.

    PubMed

    Chu, W; Law, C K

    2003-05-01

    The oxidation of 2,4,6-trichlorophenol (TCP) by ferrous-catalyzed hydrogen peroxide was quantified and modeled in the study. TCP was effectively degraded by hydroxyl radicals that were generated by Fe(II)/H(2)O(2) in the oxidation process. The oxidation capacity (OC) of the process depends on the concentrations of oxidant (hydrogen peroxide) and oxidative catalyst (ferrous ion). Up to 99.6% of TCP removal can be achieved in the process, provided the doses of Fe(II) and H(2)O(2) are selected correctly. The OC of the process was successfully predicted through a kinetic approach in a two-stage model with some simple and measurable parameters, which makes the model useful for predicting, controlling and optimizing the catalyzed oxidation process in the degradation of TCP. PMID:12727243

  9. Air-nitric acid destructive oxidation of organic wastes

    SciTech Connect

    Smith, J.R.

    1993-09-01

    Many organic materials have been completely oxidized to CO{sub 2}, CO, and inorganic acids in a 0.1M HNO{sub 3}/14.8M H{sub 3}PO{sub 4} solution with air sparging. Addition of 0.001M Pd{sub +2} reduces the CO to near 1% of the released carbon gases. To accomplish complete oxidation the solution temperature must be maintained above 130--150{degrees}C. Organic materials quantitatively destroyed include neoprene, cellulose, EDTA, TBP, tartaric acid, and nitromethane. The oxidation is usually complete in a few hours for soluble organic materials. The oxidation rate for non-aliphatic organic solids is moderately fast and surface area dependent. The rate for aliphatic organic compounds (polyethylene, PVC, and n-dodecane) is relatively very slow. This is due to the large energy required to abstract a hydrogen atom from these compounds, 99 kcal/mole. The combination of NO{sub 2}{center_dot} and H{center_dot} to produce HNO{sub 2} releases only 88 kcal/mole. Under conditions of high NO{sub 2}{center_dot} concentration it should be possible to oxidize these aliphatic compounds.

  10. The active component of vanadium-molybdenum catalysts for the oxidation of acrolein to acrylic acid

    SciTech Connect

    Andrushkevich, T.V.; Kuznetsova, T.G.

    1986-12-01

    The catalytic properties of the vanadium-molybdenum oxide system were investigated in the oxidation of acrolein to acrylic acid. The active component of the catalyst is the compound VMo/sub 3/O/sub 11/, the maximum amount of which is observed at a content of 7-15 mole% V/sub 2/O/sub 4/. The compound VMo/sub 3/O/sub 11/ is formed in the thermodecomposition of silicomolybdovanadium heteropoly acids or isopoly compounds, reduced with respect to vanadium, and contains V/sup 4 +/ and Mo/sup 6 +/. The optimum treatment for the formation of this compound is treatment in the reaction mixture at 400 degrees C.

  11. Bond energies in polyunsaturated acids and kinetics of co-oxidation of protiated and deuterated acids

    NASA Astrophysics Data System (ADS)

    Andrianova, Z. S.; Breslavskaya, N. N.; Pliss, E. M.; Buchachenko, A. L.

    2016-10-01

    A computational program specially designed to analyze co-oxidation of substances in mixtures is suggested. The rigorous kinetic scheme of 32 reactions describing co-oxidation of isotope differing polyunsaturated fatty acids was computed to enlighten experimentally detected enormously large H/D isotope effects. The latter were shown to depend on the kinetic chain length and exhibit two extreme regimes of short and long chains which characterize isotope effects on the initiation and propagation chain reactions of hydrogen (deuterium) atom abstraction. No protective effect of deuterated polyunsaturated acids on the oxidation of protiated acids was detected. Protective effect of the deuterated compounds on the biologically important processes seems to be induced by the low yield of products formed in the chain termination reactions due to the low rate of initiation by deuterated compounds.

  12. Refsum disease, peroxisomes and phytanic acid oxidation: a review.

    PubMed

    Wanders, R J; Jansen, G A; Skjeldal, O H

    2001-11-01

    Refsum disease was first recognized as a distinct disease entity by Sigvald Refsum in the 1940s. The discovery of markedly elevated levels of the branched-chain fatty acid phytanic acid in certain patients marked Refsum disease as a disorder of lipid metabolism. Although it was immediately recognized that the accumulation of phytanic acid is due to its deficient breakdown in Refsum disease patients, the true enzymatic defect remained mysterious until recently. A major breakthrough in this respect was the resolution of the mechanism of phytanic acid alpha-oxidation in humans. In this review we describe the many aspects of Refsum disease from the clinical signs and symptoms to the enzyme and molecular defect plus the recent identification of genetic heterogeneity in Refsum disease.

  13. Removal of nitric oxide from exhaust gas with cyanuric acid--

    SciTech Connect

    Siebers, D.L. . Combustion Research Faclity); Caton, J.A. . Dept. of Mechanical Engineering)

    1990-01-01

    Addition of gaseous isocyanic acid (HNCO) to the exhaust of combustion systems or chemical process is proposed as a method for reducing nitric oxide (NO) emissions. The HNCO selectively reduces NO in the exhaust through a multistep chemical reaction mechanism. This article presents an experimental investigation of the proposed NO reduction process using cyanuric acid as the source of HNCO. At elevated temperature cyanuric acid decomposes and forms HNCO. The effects of temperature, exhaust gas composition, cyanuric acid concentration (i.e., HNCO concentration), and surfaces were examined. The experiments were conducted in an electrically heated quartz flow reactor using either exhaust from a diesel engine or simulated exhaust gas. The results demonstrate that gas phase NO reduction approaching 100% can be obtained.

  14. Omega 3 Fatty Acids Supplementation and Oxidative Stress in HIV-Seropositive Patients. A Clinical Trial.

    PubMed

    Amador-Licona, Norma; Díaz-Murillo, Teresa A; Gabriel-Ortiz, Genaro; Pacheco-Moises, Fermín P; Pereyra-Nobara, Texar A; Guízar-Mendoza, Juan M; Barbosa-Sabanero, Gloria; Orozco-Aviña, Gustavo; Moreno-Martínez, Sandra C; Luna-Montalbán, Rafael; Vázquez-Valls, Eduardo

    2016-01-01

    HIV-seropositive patients show high incidence of coronary heart disease and oxidative stress has been described as relevant key in atherosclerosis development. The aim of this study was to assess the effect of omega 3 fatty acids on different markers of oxidative stress in HIV-seropositive patients. We performed a randomized parallel controlled clinical trial in The Instituto Mexicano del Seguro Social, a public health hospital. 70 HIV-seropositive patients aged 20 to 55 on clinical score A1, A2, B1 or B2 receiving highly active antiretroviral therapy (HAART) were studied. They were randomly assigned to receive omega 3 fatty acids 2.4 g (Zonelabs, Marblehead MA) or placebo for 6 months. At baseline and at the end of the study, anthropometric measurements, lipid profile, glucose and stress oxidative levels [nitric oxide catabolites, lipoperoxides (malondialdehyde plus 4-hydroxialkenals), and glutathione] were evaluated. Principal HAART therapy was EFV/TDF/FTC (55%) and AZT/3TC/EFV (15%) without difference between groups. Treatment with omega 3 fatty acids as compared with placebo decreased triglycerides (-0.32 vs. 0.54 mmol/L; p = 0.04), but oxidative stress markers were not different between groups.

  15. Omega 3 Fatty Acids Supplementation and Oxidative Stress in HIV-Seropositive Patients. A Clinical Trial.

    PubMed

    Amador-Licona, Norma; Díaz-Murillo, Teresa A; Gabriel-Ortiz, Genaro; Pacheco-Moises, Fermín P; Pereyra-Nobara, Texar A; Guízar-Mendoza, Juan M; Barbosa-Sabanero, Gloria; Orozco-Aviña, Gustavo; Moreno-Martínez, Sandra C; Luna-Montalbán, Rafael; Vázquez-Valls, Eduardo

    2016-01-01

    HIV-seropositive patients show high incidence of coronary heart disease and oxidative stress has been described as relevant key in atherosclerosis development. The aim of this study was to assess the effect of omega 3 fatty acids on different markers of oxidative stress in HIV-seropositive patients. We performed a randomized parallel controlled clinical trial in The Instituto Mexicano del Seguro Social, a public health hospital. 70 HIV-seropositive patients aged 20 to 55 on clinical score A1, A2, B1 or B2 receiving highly active antiretroviral therapy (HAART) were studied. They were randomly assigned to receive omega 3 fatty acids 2.4 g (Zonelabs, Marblehead MA) or placebo for 6 months. At baseline and at the end of the study, anthropometric measurements, lipid profile, glucose and stress oxidative levels [nitric oxide catabolites, lipoperoxides (malondialdehyde plus 4-hydroxialkenals), and glutathione] were evaluated. Principal HAART therapy was EFV/TDF/FTC (55%) and AZT/3TC/EFV (15%) without difference between groups. Treatment with omega 3 fatty acids as compared with placebo decreased triglycerides (-0.32 vs. 0.54 mmol/L; p = 0.04), but oxidative stress markers were not different between groups. PMID:27015634

  16. Omega 3 Fatty Acids Supplementation and Oxidative Stress in HIV-Seropositive Patients. A Clinical Trial

    PubMed Central

    Amador-Licona, Norma; Díaz-Murillo, Teresa A.; Pereyra-Nobara, Texar A.; Guízar-Mendoza, Juan M.; Barbosa-Sabanero, Gloria; Orozco-Aviña, Gustavo; Moreno-Martínez, Sandra C.; Luna-Montalbán, Rafael; Vázquez-Valls, Eduardo

    2016-01-01

    HIV-seropositive patients show high incidence of coronary heart disease and oxidative stress has been described as relevant key in atherosclerosis development. The aim of this study was to assess the effect of omega 3 fatty acids on different markers of oxidative stress in HIV-seropositive patients. We performed a randomized parallel controlled clinical trial in The Instituto Mexicano del Seguro Social, a public health hospital. 70 HIV-seropositive patients aged 20 to 55 on clinical score A1, A2, B1 or B2 receiving highly active antiretroviral therapy (HAART) were studied. They were randomly assigned to receive omega 3 fatty acids 2.4 g (Zonelabs, Marblehead MA) or placebo for 6 months. At baseline and at the end of the study, anthropometric measurements, lipid profile, glucose and stress oxidative levels [nitric oxide catabolites, lipoperoxides (malondialdehyde plus 4-hydroxialkenals), and glutathione] were evaluated. Principal HAART therapy was EFV/TDF/FTC (55%) and AZT/3TC/EFV (15%) without difference between groups. Treatment with omega 3 fatty acids as compared with placebo decreased triglycerides (-0.32 vs. 0.54 mmol/L; p = 0.04), but oxidative stress markers were not different between groups. Trial Registration ClinicalTrials.gov NCT02041520 PMID:27015634

  17. VASP Increases Hepatic Fatty Acid Oxidation by Activating AMPK in Mice

    PubMed Central

    Tateya, Sanshiro; Rizzo-De Leon, Norma; Handa, Priya; Cheng, Andrew M.; Morgan-Stevenson, Vicki; Ogimoto, Kayoko; Kanter, Jenny E.; Bornfeldt, Karin E.; Daum, Guenter; Clowes, Alexander W.; Chait, Alan; Kim, Francis

    2013-01-01

    Activation of AMP-activated protein kinase (AMPK) signaling reduces hepatic steatosis and hepatic insulin resistance; however, its regulatory mechanisms are not fully understood. In this study, we sought to determine whether vasodilator-stimulated phosphoprotein (VASP) signaling improves lipid metabolism in the liver and, if so, whether VASP’s effects are mediated by AMPK. We show that disruption of VASP results in significant hepatic steatosis as a result of significant impairment of fatty acid oxidation, VLDL-triglyceride (TG) secretion, and AMPK signaling. Overexpression of VASP in hepatocytes increased AMPK phosphorylation and fatty acid oxidation and reduced hepatocyte TG accumulation; however, these responses were suppressed in the presence of an AMPK inhibitor. Restoration of AMPK phosphorylation by administration of 5-aminoimidazole-4-carboxamide riboside in Vasp−/− mice reduced hepatic steatosis and normalized fatty acid oxidation and VLDL-TG secretion. Activation of VASP by the phosphodiesterase-5 inhibitor, sildenafil, in db/db mice reduced hepatic steatosis and increased phosphorylated (p-)AMPK and p-acetyl CoA carboxylase. In Vasp−/− mice, however, sildendafil treatment did not increase p-AMPK or reduce hepatic TG content. These studies identify a role of VASP to enhance hepatic fatty acid oxidation by activating AMPK and to promote VLDL-TG secretion from the liver. PMID:23349495

  18. Physical and oxidative removal of organics during Fenton treatment of mature municipal landfill leachate.

    PubMed

    Deng, Yang

    2007-07-19

    Municipal landfill leachate, especially mature leachate, may disrupt the performance of moderately-sized municipal activated sludge wastewater treatment plants, and likewise tend to be recalcitrant to biological pretreatment. Recently, Fenton methods have been investigated for chemical treatment or pre-treatment of mature leachate. In this paper, the results of laboratory tests to determine the roles of oxidation and coagulation in reducing the organic content of mature leachate during Fenton treatment are presented. The efficiencies of chemical oxygen demand (COD) oxidation and coagulation were tested, and the ratio of COD removal by oxidation to that by coagulation was assessed, under various operating conditions. Low initial pH, appropriate relative and absolute Fenton reagent dosages, aeration, and stepwise addition of reagents increased COD removal by oxidation and the importance of oxidation relative to coagulation. Simultaneous aeration and stepwise reagent addition allowed comparable treatment without initial acidification pH, due to the generation of acidic organic intermediates and the continuous input of CO2. On the other hand, high COD oxidation efficiency and low ferrous dosage inhibited COD removal by coagulation. At significantly high oxidation efficiency, overall COD reduction decrease slightly due to low coagulation efficiency. Under the most favorable conditions (initial pH 3, molar ratio [H(2)O(2)]/[Fe2+]=3, [H2O2]=240 mM, and six dosing steps), 61% of the initial COD was removed, and the ratio of COD removal oxidation to coagulation was 0.75. Results highlighted the synergistic roles of oxidation and coagulation in Fenton treatment of mature leachate, and the role of oxidation in controlling the efficiency of removal of COD by coagulation. PMID:17208367

  19. Heterogeneous OH Oxidation of Two Structure Isomers of Dimethylsuccinic Acid Aerosol: Reactivity and Oxidation Products

    NASA Astrophysics Data System (ADS)

    Chan, M. N.; Cheng, C. T.; Wilson, K. R.

    2014-12-01

    Organic aerosol contribute a significant mass fraction of ambient aerosol carbon and can continuously undergo oxidation by colliding with gas phase OH radicals. Although heterogeneous oxidation plays a significant role in the chemical transformation of organic aerosol, the effect of molecular structure on the reactivity and oxidation products remains unclear. We investigate the effect of branched methyl groups on the reactivity of two dimethylsuccinic acids (2,2-dimethylsuccinic acid (2,2-DMSA) and 2,3-dimethylsuccinic acid (2,3-DMSA)) toward gas phase OH radicals in an atmospheric pressure aerosol flow tube reactor. The oxidation products formed upon oxidation is characterized in real time by the Direct Analysis in Real Time (DART), an ambient soft ionization source. The 2,2-DMSA and 2,3-DMSA are structural isomers with the same oxidation state (OSC = -0.33) and carbon number (NC = 6), but different branching characteristics (2,2-DMSA has one secondary carbon and 2,3-DMSA has two tertiary carbons). The difference in molecular distribution of oxidation products observed in these two structural isomers would allow one to assess the sensitivity of kinetics and chemistry to the position of branched methyl group in the DMSA upon oxidation. We observe that the reactivity of 2,3-DMSA toward OH radicals is about 2 times faster than that of 2,2-DMSA. This difference in OH reactivity may attribute to the stability of the carbon-centered radical generated after hydrogen abstraction because an alkyl radical formed from the hydrogen abstraction on a tertiary carbon in 2,3-DMSA is more stable than on a secondary carbon in 2,2-DMSA. For both 2,2-DMSA and 2,3-DMSA, the molecular distribution and evolution of oxidation products is characterized by a predominance of functionalization products at the early oxidation stages. When the oxidation further proceeds, the fragmentation becomes more favorable and the oxidation mainly leads to the reduction of the carbon chain length through

  20. Oxidized fatty acids as inter-kingdom signaling molecules.

    PubMed

    Pohl, Carolina H; Kock, Johan L F

    2014-01-20

    Oxylipins or oxidized fatty acids are a group of molecules found to play a role in signaling in many different cell types. These fatty acid derivatives have ancient evolutionary origins as signaling molecules and are ideal candidates for inter-kingdom communication. This review discusses examples of the ability of organisms from different kingdoms to "listen" and respond to oxylipin signals during interactions. The interactions that will be looked at are signaling between animals and plants; between animals and fungi; between animals and bacteria and between plants and fungi. This will aid in understanding these interactions, which often have implications in ecology, agriculture as well as human and animal health.

  1. 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.

  2. Omega-3 fatty acids alter behavioral and oxidative stress parameters in animals subjected to fenproporex administration.

    PubMed

    Model, Camila S; Gomes, Lara M; Scaini, Giselli; Ferreira, Gabriela K; Gonçalves, Cinara L; Rezin, Gislaine T; Steckert, Amanda V; Valvassori, Samira S; Varela, Roger B; Quevedo, João; Streck, Emilio L

    2014-03-01

    Studies have consistently reported the participation of oxidative stress in bipolar disorder (BD). Evidences indicate that omega-3 (ω3) fatty acids play several important roles in brain development and functioning. Moreover, preclinical and clinical evidence suggests roles for ω3 fatty acids in BD. Considering these evidences, the present study aimed to investigate the effects of ω3 fatty acids on locomotor behavior and oxidative stress parameters (TBARS and protein carbonyl content) in brain of rats subjected to an animal model of mania induced by fenproporex. The fenproporex treatment increased locomotor behavior in saline-treated rats under reversion and prevention model, and ω3 fatty acids prevented fenproporex-related hyperactivity. Moreover, fenproporex increased protein carbonyls in the prefrontal cortex and cerebral cortex, and the administration of ω3 fatty acids reversed this effect. Lipid peroxidation products also are increased in prefrontal cortex, striatum, hippocampus and cerebral after fenproporex administration, but ω3 fatty acids reversed this damage only in the hippocampus. On the other hand, in the prevention model, fenproporex increased carbonyl content only in the cerebral cortex, and administration of ω3 fatty acids prevented this damage. Additionally, the administration of fenproporex resulted in a marked increased of TBARS in the prefrontal cortex, hippocampus, striatum and cerebral cortex, and prevent this damage in the prefrontal cortex, hippocampus and striatum. In conclusion, we are able to demonstrate that fenproporex-induced hyperlocomotion and damage through oxidative stress were prevented by ω3 fatty acids. Thus, the ω3 fatty acids may be important adjuvant therapy of bipolar disorder. PMID:24385143

  3. Oxidation of PAHs in a simplified system using peroxy-acid and glass beads: Identification of oxidizing species.

    PubMed

    Alderman, Norman S; Nyman, Marianne C

    2009-09-01

    Polycyclic aromatic hydrocarbons (PAHs) are organic contaminants of concern due to their ubiquity, persistence in the natural environment and adverse health effects. Numerous studies have looked into the removal and treatment of these contaminants, with mixed results. High molecular weight PAHs have been particularly problematic due to their hydrophobicity and high affinity for organics, resulting in mass transfer limitations for even the fastest advanced oxidation processes (AOPs). The peroxy-acid process has been used to successfully treat PAH contaminated matrices. Experiments were conducted on benzo[a]pyrene contaminated glass beads in order to elucidate the reaction mechanisms responsible for the effectiveness of this process. For the first time peracetic acid (PAA) was identified as the important oxidant in this reaction. Different v/v/v ratios of hydrogen peroxide/acetic acid/DI water were studied which illustrated the importance of reaction ratio on oxidant concentration and rate of formation. Approximately 60% degradation of benzo[a]pyrene was achieved in 24 hours with 1.7% PAA. Observations of the reaction kinetics suggest that the slow desorption/dissolution of benzo[a]pyrene limits the efficiency of the peroxy-acid process. Modifications of the reaction setup supported this observation as treatment efficiencies increased with reactive surface area, and an increase in system agitation. These limitations were also overcome by increasing the concentration of PAA delivered to the contaminated matrix. Greater than 80% degradation of benzo[a]pyrene was achieved in 24 hours with approximately 9.2% PAA. PMID:19847697

  4. 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

  5. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethylene oxide adduct of fatty acid... 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)...

  6. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethylene oxide adduct of fatty acid... 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)...

  7. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethylene oxide adduct of fatty acid... 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)...

  8. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethylene oxide adduct of fatty acid... 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)...

  9. 40 CFR 721.3680 - Ethylene oxide adduct of fatty acid ester with pentaerythritol.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethylene oxide adduct of fatty acid... 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)...

  10. 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.

  11. Sulfuric acid intercalated graphite oxide for graphene preparation.

    PubMed

    Hong, Yanzhong; Wang, Zhiyong; Jin, Xianbo

    2013-12-06

    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.

  12. 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.

  13. 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

  14. Effect of ammonia plasma treatment on graphene oxide LB monolayers

    SciTech Connect

    Singh, Gulbagh; Botcha, V. Divakar; Narayanam, Pavan K.; Sutar, D. S.; Talwar, S. S.; Major, S. S.; Srinivasa, R. S.

    2013-02-05

    Graphene oxide monolayer sheets were transferred on Si and SiO{sub 2}/Si substrates by Langmuir-Blodgett technique and were exposed to ammonia plasma at room temperature. The monolayer character of both graphene oxide and plasma treated graphene oxide sheets were ascertained by atomic force microscopy. X-ray photoelectron spectroscopy and Raman spectroscopy revealed that ammonia plasma treatment results in enhancement of graphitic carbon content along with the incorporation of nitrogen. The conductivity of graphene oxide monolayers, which was in the range of 10{sup -6}-10{sup -7} S/cm, increased to 10{sup -2}-10{sup -3} S/cm after the ammonia plasma treatment. These results indicate that the graphene oxide was simultaneously reduced and N-doped during ammonia plasma treatment, without affecting the morphological stability of sheets.

  15. 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.

  16. 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

  17. Nitrogen oxides and methane treatment by non-thermal plasma

    NASA Astrophysics Data System (ADS)

    Alva, E.; Pacheco, M.; Colín, A.; Sánchez, V.; Pacheco, J.; Valdivia, R.; Soria, G.

    2015-03-01

    Non thermal plasma was used to treat nitrogen oxides (NOx) and methane (CH4), since they are important constituents of hydrocarbon combustion emissions processes and, both gases, play a key role in the formation of tropospheric ozone. These gases are involved in environmental problems like acid rain and some diseases such as bronchitis and pneumonia. In the case of methane is widely known its importance in the global climate change, and currently accounts for 30% of global warming. There is a growing concern for methane leaks, associated with a rapid expansion of unconventional oil and gas extraction techniques as well as a large-scale methane release from Arctic because of ice melting and the subsequent methane production of decaying organic matter. Therefore, methane mitigation is a key to avoid dangerous levels of global warming. The research, here reported, deals about the generation of non-thermal plasma with a double dielectric barrier (2DBD) at atmospheric pressure with alternating current (AC) for NOx and CH4 treatment. The degradation efficiencies and their respective power consumption for different reactor configurations (cylindrical and planar) are also reported. Qualitative and quantitative analysis of gases degradation are reported before and after treatment with cold plasma. Experimental and theoretical results are compared obtaining good removal efficiencies, superior to 90% and to 20% respectively for NOx and CH4.

  18. PASSIVE TREATMENT OF ACID ROCK DRAINAGE FROM A SUBSURFACE MINE

    EPA Science Inventory

    Acidic, metal-contaminated drainages are a critical problem facing many areas of the world. Acid rock drainage results when metal sulfide minerals, particularly pyrite, are oxidized by exposure to oxygen and water. The deleterious effects of these drainages on receiving streams a...

  19. Microbial As(III) Oxidation in Water Treatment Plant Filters

    EPA Science Inventory

    Arsenic exists in two oxidation states in water - arsenite [As(III)] and arsenate [As(V)]. As(III) is relatively mobile in water and difficult to remove by arsenic-removal treatment processes. Source waters that contain As(III) must add a strong oxidant such as free chlorine or p...

  20. Sinapic Acid Prevents Hypertension and Cardiovascular Remodeling in Pharmacological Model of Nitric Oxide Inhibited Rats

    PubMed Central

    Silambarasan, Thangarasu; Manivannan, Jeganathan; Krishna Priya, Mani; Suganya, Natarajan; Chatterjee, Suvro; Raja, Boobalan

    2014-01-01

    Objectives Hypertensive heart disease is a constellation of abnormalities that includes cardiac fibrosis in response to elevated blood pressure, systolic and diastolic dysfunction. The present study was undertaken to examine the effect of sinapic acid on high blood pressure and cardiovascular remodeling. Methods An experimental hypertensive animal model was induced by L-NAME intake on rats. Sinapic acid (SA) was orally administered at a dose of 10, 20 and 40 mg/kg body weight (b.w.). Blood pressure was measured by tail cuff plethysmography system. Cardiac and vascular function was evaluated by Langendorff isolated heart system and organ bath studies, respectively. Fibrotic remodeling of heart and aorta was assessed by histopathologic analyses. Oxidative stress was measured by biochemical assays. mRNA and protein expressions were assessed by RT-qPCR and western blot, respectively. In order to confirm the protective role of SA on endothelial cells through its antioxidant property, we have utilized the in vitro model of H2O2-induced oxidative stress in EA.hy926 endothelial cells. Results Rats with hypertension showed elevated blood pressure, declined myocardial performance associated with myocardial hypertrophy and fibrosis, diminished vascular response, nitric oxide (NO) metabolites level, elevated markers of oxidative stress (TBARS, LOOH), ACE activity, depleted antioxidant system (SOD, CAT, GPx, reduced GSH), aberrant expression of TGF-β, β-MHC, eNOS mRNAs and eNOS protein. Remarkably, SA attenuated high blood pressure, myocardial, vascular dysfunction, cardiac fibrosis, oxidative stress and ACE activity. Level of NO metabolites, antioxidant system, and altered gene expression were also repaired by SA treatment. Results of in vitro study showed that, SA protects endothelial cells from oxidative stress and enhance the production of NO in a concentration dependent manner. Conclusions Taken together, these results suggest that SA may have beneficial role in the

  1. Importance of acid-base equilibrium in electrocatalytic oxidation of formic acid on platinum.

    PubMed

    Joo, Jiyong; Uchida, Taro; Cuesta, Angel; Koper, Marc T M; Osawa, Masatoshi

    2013-07-10

    Electro-oxidation of formic acid on Pt in acid is one of the most fundamental model reactions in electrocatalysis. However, its reaction mechanism is still a matter of strong debate. Two different mechanisms, bridge-bonded adsorbed formate mechanism and direct HCOOH oxidation mechanism, have been proposed by assuming a priori that formic acid is the major reactant. Through systematic examination of the reaction over a wide pH range (0-12) by cyclic voltammetry and surface-enhanced infrared spectroscopy, we show that the formate ion is the major reactant over the whole pH range examined, even in strong acid. The performance of the reaction is maximal at a pH close to the pKa of formic acid. The experimental results are reasonably explained by a new mechanism in which formate ion is directly oxidized via a weakly adsorbed formate precursor. The reaction serves as a generic example illustrating the importance of pH variation in catalytic proton-coupled electron-transfer reactions.

  2. Treatment of NASH with ursodeoxycholic acid: pro.

    PubMed

    Ratziu, Vlad

    2012-09-01

    Ursodeoxycholic acid (UDCA) is one of hepatologists'oldest friends, always ready to help, throughout the years, in numerous and various liver and biliary tract diseases. On paper, it has had an impeccable track record of cytoprotection in vitro and in vivo due to its pleiotropic effects on many pathways leading to cell injury. Most of its hepatoprotective effects demonstrated under experimental conditions proved able to counteract pathogenic mechanisms involved in the transition from steatosis to steatohepatitis, and early clinical studies suggested a potentially beneficial effect in non-alcoholic steatohepatitis (NASH) as well. Yet, only scant data on the efficacy of UDCA specifically in experimental models of steatosis/NASH are available, and the few available randomized controlled clinical studies have substantial methodological issues and are discussed in this review. Thus, at this point, there is not enough evidence to either confirm or reject the efficacy of UDCA in NASH, although many NASH patients clearly experience biochemical improvements with prolonged UDCA treatment. Also, a few new UDCA derivatives have shown promising activity in preclinical models and may be worth testing in clinical trials. PMID:23141893

  3. The effect of limestone treatments on the rate of acid generation from pyritic mine gangue.

    PubMed

    Burt, R A; Caruccio, F T

    1986-09-01

    Surface water enters the Haile Gold Mine, Lancaster County, South Carolina by means of a small stream and is ponded behind a dam and in an abandoned pit. This water is affected by acidic drainage. In spite of the large exposures of potentially acid producing pyritic rock, the flux of acid to the water is relatively low. Nevertheless, the resulting pH values of the mine water are low (around 3.5) due to negligible buffering capacity. In view of the observed low release of acidity, the potential for acid drainage abatement by limestone ameliorants appears feasible.This study investigated the effects of limestone treatment on acid generation rates of the Haile mine pyritic rocks through a series of leaching experiments. Below a critical alkalinity threshold value, solutions of dissolved limestone were found consistently to accelerate the rate of pyrite oxidation by varying degrees. The oxidation rates were further accelerated by admixing solid limestone with the pyritic rock. However, after a period of about a month, the pyrite oxidation rate of the admixed samples declined to a level lower than that of untreated pyrite. Leachates produced by the pyrite and limestone mixtures contained little if any iron. Further, in the mixtures, an alteration of the pyrite surface was apparent.The observed behaviour of the treated pyrite appears to be related to the immersion of the pyrite grains within a high alkalinity/high pH environment. The high pH increases the rate of oxidation of ferrous iron which results in a higher concentration of ferric iron at the pyrite surface. This, in turn, increases the rate of pyrite oxidation. Above a threshold alkalinity value, the precipitation of hydrous iron oxides at the pyrite surface eventually outpaces acid generation and coats the pyrite surface, retarding the rate of pyrite oxidation. PMID:24214013

  4. Protective effect of arjunolic acid against arsenic-induced oxidative stress in mouse brain.

    PubMed

    Sinha, Mahua; Manna, Prasenjit; Sil, Parames C

    2008-02-01

    Arsenic, a notoriously poisonous metalloid, is ubiquitous in the environment, and it affects nearly all organ systems of animals including humans. The present study was designed to investigate the preventive role of a triterpenoid saponin, arjunolic acid against arsenic-induced oxidative damage in murine brain. Sodium arsenite was selected as a source of arsenic for this study. The free-radical-scavenging activity and the in vivo antioxidant power of arjunolic acid were determined from its 2,2-diphenyl-1-picryl hydrazyl radical scavenging ability and ferric reducing/antioxidant power assay, respectively. Oral administration of sodium arsenite at a dose of 10 mg/kg body weight for 2 days significantly decreased the activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase and glutathione peroxidase, the level of cellular metabolites, reduced glutathione, total thiols and increased the level of oxidized glutathione. In addition, it enhanced the levels of lipid peroxidation end products and protein carbonyl content. Treatment with arjunolic acid at a dose of 20 mg/kg body weight for 4 days prior to arsenic administration almost normalized above indices. Histological findings due to arsenic intoxication and arjunolic acid treatment supported the other biochemical changes in murine brains. Results of 2,2-diphenyl-1-picryl hydrazyl radical scavenging and ferric reducing/antioxidant power assays clearly showed the in vitro radical scavenging as well as the in vivo antioxidant power of arjunolic acid, respectively. The effect of a well-established antioxidant, vitamin C, has been included in the study as a positive control. Combining all, results suggest that arjunolic acid possessed the ability to ameliorate arsenic-induced oxidative insult in murine brain and is probably due to its antioxidant activity.

  5. 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

  6. Effects of alkali or acid treatment on the isomerization of amino acids.

    PubMed

    Ohmori, Taketo; Mutaguchi, Yuta; Doi, Katsumi; Ohshima, Toshihisa

    2012-10-01

    The effect of alkali treatment on the isomerization of amino acids was investigated. The 100×D/(D+L) values of amino acids from peptide increased with increase in the number of constituent amino acid residues. Furthermore, the N-terminal amino acid of a dipeptide was isomerized to a greater extent than the C-terminal residue.

  7. Acetic acid enhances endurance capacity of exercise-trained mice by increasing skeletal muscle oxidative properties.

    PubMed

    Pan, Jeong Hoon; Kim, Jun Ho; Kim, Hyung Min; Lee, Eui Seop; Shin, Dong-Hoon; Kim, Seongpil; Shin, Minkyeong; Kim, Sang Ho; Lee, Jin Hyup; Kim, Young Jun

    2015-01-01

    Acetic acid has been shown to promote glycogen replenishment in skeletal muscle during exercise training. In this study, we investigated the effects of acetic acid on endurance capacity and muscle oxidative metabolism in the exercise training using in vivo mice model. In exercised mice, acetic acid induced a significant increase in endurance capacity accompanying a reduction in visceral adipose depots. Serum levels of non-esterified fatty acid and urea nitrogen were significantly lower in acetic acid-fed mice in the exercised mice. Importantly, in the mice, acetic acid significantly increased the muscle expression of key enzymes involved in fatty acid oxidation and glycolytic-to-oxidative fiber-type transformation. Taken together, these findings suggest that acetic acid improves endurance exercise capacity by promoting muscle oxidative properties, in part through the AMPK-mediated fatty acid oxidation and provide an important basis for the application of acetic acid as a major component of novel ergogenic aids.

  8. 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.

  9. Combined Low-Intensity Exercise and Ascorbic Acid Attenuates Kainic Acid-Induced Seizure and Oxidative Stress in Mice.

    PubMed

    Kim, Hee-Jae; Song, Wook; Jin, Eun Hee; Kim, Jongkyu; Chun, Yoonseok; An, Eung Nam; Park, Sok

    2016-05-01

    Physical exercise and vitamins such as ascorbic acid (ASC) have been recognized as an effective strategy in neuroprotection and neurorehabilitatioin. However, there is a need to find an efficient treatment regimen that includes ASC and low-intensity exercise to diminish the risk of overtraining and nutritional treatment by attenuating oxidative stress. In the present study, we investigated the combined effect of low-intensity physical exercise (EX) and ASC on kainic acid (KA)-induced seizure activity and oxidative stress in mice. The mice were randomly assigned into groups as follows: "KA only" (n = 11), "ASC + KA" (n = 11), "Ex + KA" (n = 11), "ASC + Ex + KA" (n = 11). In the present study, low intensity of swimming training period lasted 8 weeks and consisted of 30-min sessions daily (three times per week) without tail weighting. Although no preventive effect of low-intensity exercise or ASC on KA seizure occurrence was evident, there was a decrease of seizure activity, seizure development (latency to first seizures), and mortality in "ASC + Ex + KA" compared to "ASC + KA", "Ex + KA", and "KA only" group. In addition, a preventive synergistic coordination of low-intensity exercise and ASC was evident in glutathione peroxidase and superoxide dismutase activity compared to separate treatment. These results suggest that low-intensity exercise and ASC treatment have preventive effects on seizure activity and development with alternation of oxidative status. PMID:26646003

  10. Salicylic Acid Induction of Flavonoid Biosynthesis Pathways in Wheat Varies by Treatment

    PubMed Central

    Gondor, Orsolya K.; Janda, Tibor; Soós, Vilmos; Pál, Magda; Majláth, Imre; Adak, Malay K.; Balázs, Ervin; Szalai, Gabriella

    2016-01-01

    Salicylic acid is a promising compound for the reduction of stress sensitivity in plants. Although several biochemical and physiological changes have been described in plants treated with salicylic acid, the mode of action of the various treatments has not yet been clarified. The present work reports a detailed comparative study on the effects of different modes of salicylic acid application at the physiological, metabolomic, and transcriptomic levels. Seed soaking and hydroponic treatments were found to induce various changes in the protective mechanisms of wheat plants. The possible involvement of the flavonoid metabolism in salicylic acid-related stress signaling was also demonstrated. Different salicylic acid treatments were shown to induce different physiological and biochemical processes, with varying responses in the leaves and roots. Hydroponic treatment enhanced the level of oxidative stress, the expression of genes involved in the flavonoid metabolism and the amount of non-enzymatic antioxidant compounds, namely ortho-hydroxycinnamic acid and the flavonol quercetin in the leaves, while it decreased the ortho-hydroxycinnamic acid and flavonol contents and enhanced ascorbate peroxidase activity in the roots. In contrast, seed soaking only elevated the gene expression level of phenylalanine ammonia lyase in the roots and caused a slight increase in the amount of flavonols. These results draw attention to the fact that the effects of exogenous salicylic acid application cannot be generalized in different experimental systems and that the flavonoid metabolism may be an important part of the action mechanisms induced by salicylic acid. PMID:27733857

  11. Antioxidant activities of a polyglucuronic acid sodium salt obtained from TEMPO-mediated oxidation of xanthan.

    PubMed

    Delattre, C; Pierre, G; Gardarin, C; Traikia, M; Elboutachfaiti, R; Isogai, A; Michaud, P

    2015-02-13

    A xanthouronic acid sodium salt called xanthouronan was produced from xanthan by regioselective oxidation with NaOCl/NaBr using 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) as catalyst. The efficiency of the one pot TEMPO-mediated oxidation was confirmed by HPAEC-PAD, (13)C NMR, and FT-IR. The oxidation degree was close to 98% and the mass yield of this new polyglucuronic acid was higher than 90% (w/w). The macromolecular characterization of xanthouronan using SEC-MALLS showed a molecular size reduced by a third due to the oxidation treatment and the degree of polymerization (DP) of the xanthouronan form was about 665. The evaluation of the enzymatic degradation of this C-6 carboxylated xanthan by various polysaccharide hydrolases and one polysaccharide lyase showed its high resistant to biodegradation. The antioxidant activity of xanthouronan was also tested by using the 2,2'-diphenyl-1-picrylhydrazyle (DPPH) and hydroxyl radical procedures. At 1 g/L, xanthouronan presented 75% of the ascorbic acid antioxidant activity.

  12. The association between low-grade inflammation, iron status and nucleic acid oxidation in the elderly

    PubMed Central

    Broedbaek, Kasper; Siersma, Volkert; Andersen, Jon T.; Petersen, Morten; Afzal, Shoaib; Hjelvang, Brian; Weimann, Allan; Semba, Richard D.; Ferrucci, Luigi; Poulsen, Henrik E.

    2016-01-01

    This study applied a case-control approach to investigate the association between low-grade inflammation, defined by high values within the normal range of C-reactive protein (CRP) and interleukin-6 (IL-6), and urinary markers of nucleic acid oxidation. No differences in excretion of urinary markers of nucleic acid oxidation between cases and controls were found and multivariable linear regression analysis showed no association between urinary markers of nucleic acid oxidation and inflammatory markers. Post-hoc multivariable linear regression analysis showed significant associations between nucleic acid oxidation and various iron status markers and especially a close relationship between nucleic acid oxidation and ferritin. This study shows no association between low-grade inflammation and urinary markers of nucleic acid oxidation in a population of elderly Italian people. The results suggest that low-grade inflammation only has a negligible impact on whole body nucleic acid oxidation, whereas iron status seems to be of great importance. PMID:21275071

  13. Omega-3 fatty acid oxidation products prevent vascular endothelial cell activation by coplanar polychlorinated biphenyls

    SciTech Connect

    Majkova, Zuzana; Layne, Joseph; Sunkara, Manjula; Morris, Andrew J.; Toborek, Michal; Hennig, Bernhard

    2011-02-15

    Coplanar polychlorinated biphenyls (PCBs) may facilitate development of atherosclerosis by stimulating pro-inflammatory pathways in the vascular endothelium. Nutrition, including fish oil-derived long-chain omega-3 fatty acids, such as docosahexaenoic acid (DHA, 22:6{omega}-3), can reduce inflammation and thus the risk of atherosclerosis. We tested the hypothesis that cyclopentenone metabolites produced by oxidation of DHA can protect against PCB-induced endothelial cell dysfunction. Oxidized DHA (oxDHA) was prepared by incubation of the fatty acid with the free radical generator 2,2-azo-bis(2-amidinopropane) dihydrochloride (AAPH). Cellular pretreatment with oxDHA prevented production of superoxide induced by PCB77, and subsequent activation of nuclear factor-{kappa}B (NF-{kappa}B). A{sub 4}/J{sub 4}-neuroprostanes (NPs) were identified and quantitated using HPLC ESI tandem mass spectrometry. Levels of these NPs were markedly increased after DHA oxidation with AAPH. The protective actions of oxDHA were reversed by treatment with sodium borohydride (NaBH{sub 4}), which concurrently abrogated A{sub 4}/J{sub 4}-NP formation. Up-regulation of monocyte chemoattractant protein-1 (MCP-1) by PCB77 was markedly reduced by oxDHA, but not by un-oxidized DHA. These protective effects were proportional to the abundance of A{sub 4}/J{sub 4} NPs in the oxidized DHA sample. Treatment of cells with oxidized eicosapentaenoic acid (EPA, 20:5{omega}-3) also reduced MCP-1 expression, but less than oxDHA. Treatment with DHA-derived cyclopentenones also increased DNA binding of NF-E2-related factor-2 (Nrf2) and downstream expression of NAD(P)H:quinone oxidoreductase (NQO1), similarly to the Nrf-2 activator sulforaphane. Furthermore, sulforaphane prevented PCB77-induced MCP-1 expression, suggesting that activation of Nrf-2 mediates the observed protection against PCB77 toxicity. Our data implicate A{sub 4}/J{sub 4}-NPs as mediators of omega-3 fatty acid-mediated protection against the

  14. Composition of acid tars from sulfuric acid treatment of petroleum oils

    SciTech Connect

    Frolov, A.F.; Denisova, T.L.; Karpova, I.V.; Titova, T.S.

    1986-01-01

    This paper examines the composition of freshly produced acid tars and pond tars, gives an analysis of the acid part of the tars, and obtains data on the change in composition of the acid tar in the course of storage--data that are needed in developing methods for utilizing the tar. The acid-pond tars consist of a mixture of hydrocarbons with a very low content of acids, whereas the freshly produced acid tars consist mainly of sulfuric acid, sulfonic acids, and carboxylic acids. In the course of storage, hardening of acid tars in the volume proceeds through reactions of polymerization, condensation, and oxidation of the surface layer that is in contact with air.

  15. Pretreatment with anti-oxidants sensitizes oxidatively stressed human cancer cells to growth inhibitory effect of suberoylanilide hydroxamic acid (SAHA)

    PubMed Central

    Mahlum, Amy; Mehraein-Ghomi, Farideh; Kegel, Stacy J.; Guo, Song; Peters, Noel R.; Wilding, George

    2013-01-01

    Purpose Most prostate, colon and breast cancer cells are resistant to growth inhibitory effects of suberoylanilide hydroxamic acid (SAHA). We have examined whether the high oxidative stress in these cells causes a loss of SAHA activity and if so, whether pretreatment with an anti-oxidant can sensitize these cells to SAHA. Methods A DNA-Hoechst dye fluorescence measured cell growth and dichlorfluorescein-diacetate (DCF-DA) dye fluorescence measured reactive oxygen species (ROS). Growth inhibitory and ROS-generating activities of SAHA in androgen-treated or untreated LNCaP cells and PC-3 prostate cancer cells, HT-29 and HCT-115 colon cancer cells, MDA-MB231 breast cancer cells and A549 and NCI-H460 lung cancer cells with or without pretreatment with an anti-oxidant Vitamin E was determined. SAHA activity against LNCaP cells treated with another anti-oxidant N-acetyl cysteine (NAC) was also determined. Liquid chromatography–mass spectrometry (LC–MS) was used to determine intracellular SAHA level. Results SAHA treatment markedly inhibits LNCaP cell growth, when the cells are at a low ROS level. SAHA is, however, inactive against the same cell line, when the cells are at a high ROS level. A significant decrease in SAHA level was observed in LNCaP cells with high ROS after 24-and 72-h treatment when compared to cells with low ROS. Vitamin E pretreatment that reduces cellular ROS, synergistically sensitizes oxidatively stressed LNCaP, PC-3, HT-29, HCT-115 and MDA-MB231 cells, but not the A-549 and NCI-H460 cells with low ROS to SAHA. NAC treatment also sensitized androgen-treated LNCaP cells to the growth inhibitory effects of SAHA. Conclusion Response to SAHA could be improved by combining anti-oxidants such as Vitamin E with SAHA for the treatment of oxidatively stressed human malignancies that are otherwise resistant to SAHA. PMID:20512578

  16. 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

  17. Development of procedures for determining the amino acid requirements of chickens by the indicator amino acid oxidation method.

    PubMed

    Ewing, H P; Pesti, G M; Bakalli, R I

    2001-02-01

    To better understand the amino acid requirements of chickens, a method is needed to determine a point estimate of the requirement. A method developed to determine the amino acid requirements of piglets and human infants by using the oxidation rate of an indicator amino acid as the test parameter was adapted for use in growing chickens. Polycarbonate chambers measuring 30 x 40 x 30 (L x W x H) were constructed to house one small mature chicken or several small immature chickens and to trap exhaled CO2. In the first experiment, 10-d-old chicks (250 to 300 g each) were feed deprived for 12 h and given 1 g of a methionine-deficient diet (gavage) with L-[1-C14]phenylalanine. Peak oxidation of L-[1-C14]phenylalanine occurred between 30 and 90 min (-200 dpm/g). A linear rate of oxidation (slope = -1.84; r2 = 0.96) was achieved by 120 min after feeding until after 180 min, when oxidation stabilized at a low rate. The second experiment tested different chambers and chicks with the same treatment to show repeatability. There were four chicks (250 to 300 g each) in each of three apparently identical chambers. Chicks were given two meals labeled with L-[1-C14]phenylalanine, 2 h apart. The CV for the 0- and 30-min collections were 17 and 10%, respectively. The CV for the remaining collections remained at <4%. These data supported a system of two feedings, 2 h apart to reduce variability and a collection period that included up to 3 h after the second feeding.

  18. Mitochondrial free fatty acid β-oxidation supports oxidative phosphorylation and proliferation in cancer cells.

    PubMed

    Rodríguez-Enríquez, Sara; Hernández-Esquivel, Luz; Marín-Hernández, Alvaro; El Hafidi, Mohammed; Gallardo-Pérez, Juan Carlos; Hernández-Reséndiz, Ileana; Rodríguez-Zavala, José S; Pacheco-Velázquez, Silvia C; Moreno-Sánchez, Rafael

    2015-08-01

    Oxidative phosphorylation (OxPhos) is functional and sustains tumor proliferation in several cancer cell types. To establish whether mitochondrial β-oxidation of free fatty acids (FFAs) contributes to cancer OxPhos functioning, its protein contents and enzyme activities, as well as respiratory rates and electrical membrane potential (ΔΨm) driven by FFA oxidation were assessed in rat AS-30D hepatoma and liver (RLM) mitochondria. Higher protein contents (1.4-3 times) of β-oxidation (CPT1, SCAD) as well as proteins and enzyme activities (1.7-13-times) of Krebs cycle (KC: ICD, 2OGDH, PDH, ME, GA), and respiratory chain (RC: COX) were determined in hepatoma mitochondria vs. RLM. Although increased cholesterol content (9-times vs. RLM) was determined in the hepatoma mitochondrial membranes, FFAs and other NAD-linked substrates were oxidized faster (1.6-6.6 times) by hepatoma mitochondria than RLM, maintaining similar ΔΨm values. The contents of β-oxidation, KC and RC enzymes were also assessed in cells. The mitochondrial enzyme levels in human cervix cancer HeLa and AS-30D cells were higher than those observed in rat hepatocytes whereas in human breast cancer biopsies, CPT1 and SCAD contents were lower than in human breast normal tissue. The presence of CPT1 and SCAD in AS-30D mitochondria and HeLa cells correlated with an active FFA utilization in HeLa cells. Furthermore, the β-oxidation inhibitor perhexiline blocked FFA utilization, OxPhos and proliferation in HeLa and other cancer cells. In conclusion, functional mitochondria supported by FFA β-oxidation are essential for the accelerated cancer cell proliferation and hence anti-β-oxidation therapeutics appears as an alternative promising approach to deter malignant tumor growth.

  19. 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.

  20. Nordihydroguaiaretic Acid Attenuates the Oxidative Stress-Induced Decrease of CD33 Expression in Human Monocytes

    PubMed Central

    Guzmán-Beltrán, Silvia; Pedraza-Chaverri, José; Gonzalez-Reyes, Susana; Juarez-Figueroa, Ulises E.; Gonzalez, Yolanda

    2013-01-01

    Nordihydroguaiaretic acid (NDGA) is a natural lignan with recognized antioxidant and beneficial properties that is isolated from Larrea tridentata. In this study, we evaluated the effect of NDGA on the downregulation of oxidant stress-induced CD33 in human monocytes (MNs). Oxidative stress was induced by iodoacetate (IAA) or hydrogen peroxide (H2O2) and was evaluated using reactive oxygen species (ROS) production, and cell viability. NDGA attenuates toxicity, ROS production and the oxidative stress-induced decrease of CD33 expression secondary to IAA or H2O2 in human MNs. It was also shown that NDGA (20 μM) attenuates cell death in the THP-1 cell line that is caused by treatment with either IAA or H2O2. These results suggest that NDGA has a protective effect on CD33 expression, which is associated with its antioxidant activity in human MNs. PMID:23533689

  1. Sulfur Oxidation, Microbes And Acidity In A Mine Tailings Lake

    NASA Astrophysics Data System (ADS)

    Warren, L. A.; Bernier, L.

    2003-12-01

    Disposal of tailings (waste rock) aqueously is a common approach at mine sites to minimize oxidation of the associated sulfur minerals (pyrrhotite, pyrite) and the associated generation of acidity that accompanies this process. The study site, Moose Lake, receives tailings runoff at a nickel mine in Northern Ontario, which has rendered the lake highly acidic (surface pH values less than 3.5) with high metal loads and on-going acid export to off-site, downstream systems. To investigate the potential influence of microbial processes for acid generation, as well as characterizing any attendant influences for metal behaviour, the biogeochemistry of Moose Lake was characterized on a seasonal and a diel basis during the summer of 2002. Physico-chemical profiles were used to identify the area of strong redox gradient across the thermocline (typically 1 to 2 metres across this zone) on each sampling day. Samples at five depths within this redox gradient, were then collected for Fe3+/Fe2+, SO42-/H2S, metal and microbial samples, in addition to more highly resolved Hydrolab profiling. Samples were collected both during the lighted portion of the day (10am-12pm) and at dusk (6pm-8pm) to evaluate any contributions to S and Fe cycling attributed to photosynthetic activity. Results indicate a clear seasonal increase in acidity in the upper waters of the lake: pH values dropped from 3.19 in May to 2.90 in September. Further, a strong diel trend of increasing acidity (lower pH) from mid morning to dusk was also observed for each sampling period. Biotic control on S processes appears to be important associated with the thermocline region of the lake, whilst surficial processes occurring in the upper one to three meters are more consistent with a dominant abiotic control. Both pathways contribute to acidity generation, however the controls and rates differ. These results and implications for mitigation strategies will be presented.

  2. 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

  3. Efficacy of trans-2-hydroxycinnamic Acid against trichlorfon-induced oxidative stress in wistar rats.

    PubMed

    Sharma, Poonam; Singh, Rambir

    2012-09-01

    Trichlorfon is an organophosphate insecticide used to control cockroaches, crickets, silverfish, bedbugs, fleas, cattle grubs, flies, ticks, leaf miners, and leaf-hoppers. It is also used to treat domestic animals for control of internal parasites. Trans-2-hydroxycinnamic acid (T2HCA) is a hydroxyl derivative of cinnamic acid. The present study highlights trichlorofon-induced toxicity and the protective role of T2HCA in the liver, kidney, and brain of female Wistar rats. The rats were given a single dose of trichlorofon (150 mg / kg bw) and pre- and post-treatment T2HCA (50 mg / kg bw) for seven days. Trichlorofon enhanced oxidative stress in liver, kidney, and brain of the rats, which was evident from the elevation of lipid peroxidation (LPO). The reduced level of non-enzymatic antioxidant glutathione (GSH) also indicated the presence of an oxidative insult. The activity of enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx) was significantly decreased on trichlorfon administration. Pre and post treatment with T2HCA decreased the LPO level and increased SOD, CAT, GST, GR, GPx, and GSH in the brain, liver, and kidney. Trichlorfon-induced reduction in acelylcholinestrase was also ameliorated with T2HCA treatment. In conclusion, trichlorfon-mediated induction in the reactive oxygen species and disturbance in the antioxidant enzymes' defense system was moderately ameliorated by antioxidant trans-2-hydroxycinnamic acid. PMID:23293469

  4. Efficacy of Trans-2-Hydroxycinnamic Acid Against Trichlorfon-Induced Oxidative Stress in Wistar Rats

    PubMed Central

    Sharma, Poonam; Singh, Rambir

    2012-01-01

    Trichlorfon is an organophosphate insecticide used to control cockroaches, crickets, silverfish, bedbugs, fleas, cattle grubs, flies, ticks, leaf miners, and leaf-hoppers. It is also used to treat domestic animals for control of internal parasites. Trans-2-hydroxycinnamic acid (T2HCA) is a hydroxyl derivative of cinnamic acid. The present study highlights trichlorofon-induced toxicity and the protective role of T2HCA in the liver, kidney, and brain of female Wistar rats. The rats were given a single dose of trichlorofon (150 mg / kg bw) and pre- and post-treatment T2HCA (50 mg / kg bw) for seven days. Trichlorofon enhanced oxidative stress in liver, kidney, and brain of the rats, which was evident from the elevation of lipid peroxidation (LPO). The reduced level of non-enzymatic antioxidant glutathione (GSH) also indicated the presence of an oxidative insult. The activity of enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx) was significantly decreased on trichlorfon administration. Pre and post treatment with T2HCA decreased the LPO level and increased SOD, CAT, GST, GR, GPx, and GSH in the brain, liver, and kidney. Trichlorfon-induced reduction in acelylcholinestrase was also ameliorated with T2HCA treatment. In conclusion, trichlorfon-mediated induction in the reactive oxygen species and disturbance in the antioxidant enzymes’ defense system was moderately ameliorated by antioxidant trans-2-hydroxycinnamic acid. PMID:23293469

  5. Vanillic acid prevents the deregulation of lipid metabolism, endothelin 1 and up regulation of endothelial nitric oxide synthase in nitric oxide deficient hypertensive rats.

    PubMed

    Kumar, Subramanian; Prahalathan, Pichavaram; Saravanakumar, Murugesan; Raja, Boobalan

    2014-11-15

    Hypertension is one of the main factors causing cardiovascular diseases. The present study was designed to evaluate the protective effect of vanillic acid against nitric oxide deficient rats. Hypertension was induced in adult male albino rats of Wistar strain, weighing 180-220g, by oral administration of N(ω)-nitro-l arginine methyl ester (l-NAME) 40mg/kg in drinking water for 4 weeks. Vanillic acid was administered orally at a dose of 50mg/kg b.w. Nitric oxide deficient rats showed increased levels of mean arterial pressure (MAP), heart rate (HR) and decreased heart nitric oxide metabolites (NOx). A significant increase in the levels of plasma cholesterol, low density lipoprotein-cholesterol (LDL-C), very low density lipoprotein-cholesterol (VLDL-C), triglycerides (TG), free fatty acids (FFA), phospholipids (PL), 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase in the plasma, liver and kidney and decreased level of high density lipoprotein-cholesterol (HDL-C) are observed, whereas there is a decrease in the activities of plasma lipoprotein lipase (LPL) and lecithin cholesterol acyl transferase (LCAT) in nitric oxide deficient rats. l-NAME rats also showed an increase in TC, TG, FFA and PL levels in the liver and kidney tissues. Vanillic acid treatment brought the above parameters towards near normal level. Moreover the down regulated endothelial nitric oxide synthase (eNOS) and up regulated expression of endothelin 1 (ET1) components was also attenuated by vanillic acid treatment. All the above outcomes were confirmed by the histopathological examination. These results suggest that vanillic acid has enough potential to attenuate hypertension, dyslipidemia and hepatic and renal damage in nitric oxide deficient rats. PMID:25239071

  6. Titania nanotubes from weak organic acid electrolyte: fabrication, characterization and oxide film properties.

    PubMed

    Munirathinam, Balakrishnan; Neelakantan, Lakshman

    2015-04-01

    In this study, TiO2 nanotubes were fabricated using anodic oxidation in fluoride containing weak organic acid for different durations (0.5h, 1h, 2h and 3h). Scanning electron microscope (SEM) micrographs reveal that the morphology of titanium oxide varies with anodization time. Raman spectroscopy and X-ray diffraction (XRD) results indicate that the as-formed oxide nanotubes were amorphous in nature, yet transform into crystalline phases (anatase and rutile) upon annealing at 600°C. Wettability measurements show that both as-formed and annealed nanotubes exhibited hydrophilic behavior. The electrochemical behavior was ascertained by DC polarization and AC electrochemical impedance spectroscopy (EIS) measurements in 0.9% NaCl solution. The results suggest that the annealed nanotubes showed higher impedance (10(5)-10(6)Ωcm(2)) and lower passive current density (10(-7)Acm(-2)) than the as-formed nanotubes. In addition, we investigated the influence of post heat treatment on the semiconducting properties of the oxides by capacitance measurements. In vitro bioactivity test in simulated body fluid (SBF) showed that precipitation of Ca/P is easier in crystallized nanotubes than the amorphous structure. Our study uses a simple strategy to prepare nano-structured titania films and hints the feasibility of tailoring the oxide properties by thermal treatment, producing surfaces with better bioactivity.

  7. Medium-chain fatty acids undergo elongation before {beta}-oxidation in fibroblasts

    SciTech Connect

    Jones, Patricia M. . E-mail: Patti.Jones@childrens.com; Butt, Yasmeen; Messmer, Bette; Boriak, Richard; Bennett, Michael J.

    2006-07-21

    Although mitochondrial fatty acid {beta}-oxidation (FAO) is considered to be well understood, further elucidation of the pathway continues through evaluation of patients with FAO defects. The FAO pathway can be examined by measuring the 3-hydroxy-fatty acid (3-OHFA) intermediates. We present a unique finding in the study of this pathway: the addition of medium-chain fatty acids to the culture media of fibroblasts results in generation of 3-OHFAs which are two carbons longer than the precursor substrate. Cultured skin fibroblasts from normal and LCHAD-deficient individuals were grown in media supplemented with various chain-length fatty acids. The cell-free medium was analyzed for 3-OHFAs by stable-isotope dilution gas-chromatography/mass-spectrometry. Our finding suggests that a novel carbon chain-length elongation process precedes the oxidation of medium-chain fatty acids. This previously undescribed metabolic step may have important implications for the metabolism of medium-chain triglycerides, components in the dietary treatment of a number of disorders.

  8. Mesoporous Nb and Ta Oxides: Synthesis, Characterization and Applications in Heterogeneous Acid Catalysis

    NASA Astrophysics Data System (ADS)

    Rao, Yuxiang Tony

    In this work, a series of mesoporous Niobium and Tantalum oxides with different pore sizes (C6, C12, C18 , ranging from 12A to 30 A) were synthesized using the ligand-assisted templating approach and investigated for their activities in a wide range of catalytic applications including benzylation, alkylation and isomerization. The as-synthesized mesoporous materials were characterized by nitrogen adsorption, powder X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), and solid-state Nuclear magnetic resonance (NMR) techniques. In order to probe into the structural and coordination geometry of mesoporous Nb oxide and in efforts to make meaningful comparisons of mesoporous niobia prepared by the amine-templating method with the corresponding bulk sol-gel prepared Nb2O5 phase, 17O magic-angle-spinning solid-state NMR studies were conducted. The results showed a very high local order in the mesoporous sample. The oxygen atoms are coordinated only as ONb 2 in contrast with bulk phases in which the oxygen atoms are always present in a mixture of ONb2 and ONb3 coordination environments. To enhance their surface acidities and thus improve their performance as solid acid catalysts in the acid-catalyzed reactions mentioned above, pure mesoporous Nb and Ta oxides were further treated with 1M sulfuric acid or phosphoric acid. Their surface acidities before and after acid treatment were measured by Fourier transform infraRed (FT IR), amine titration and temperature programmed desorption of ammonia (NH3-TPD). Results obtained in this study showed that sulfated mesoporous Nb and Ta oxides materials possess relative high surface areas (up to 612 m 2/g) and amorphous wormhole structure. These mesoporous structures are thus quite stable to acid treatment. It was also found that Bronsted (1540 cm-1) and Lewis (1450 cm-1) acid sites coexist in a roughly 50:50 mixture

  9. Tracking the oxidative kinetics of carbohydrates, amino acids and fatty acids in the house sparrow using exhaled 13CO2.

    PubMed

    McCue, M D; Sivan, O; McWilliams, S R; Pinshow, B

    2010-03-01

    Clinicians commonly measure the (13)CO(2) in exhaled breath samples following administration of a metabolic tracer (breath testing) to diagnose certain infections and metabolic disorders. We believe that breath testing can become a powerful tool to investigate novel questions about the influence of ecological and physiological factors on the oxidative fates of exogenous nutrients. Here we examined several predictions regarding the oxidative kinetics of specific carbohydrates, amino acids and fatty acids in a dietary generalist, the house sparrow (Passer domesticus). After administering postprandial birds with 20 mg of one of seven (13)C-labeled tracers, we measured rates of (13)CO(2) production every 15 min over 2 h. We found that sparrows oxidized exogenous amino acids far more rapidly than carbohydrates or fatty acids, and that different tracers belonging to the same class of physiological fuels had unique oxidative kinetics. Glycine had a mean maximum rate of oxidation (2021 nmol min(-1)) that was significantly higher than that of leucine (351 nmol min(-1)), supporting our prediction that nonessential amino acids are oxidized more rapidly than essential amino acids. Exogenous glucose and fructose were oxidized to a similar extent (5.9% of dose), but the time required to reach maximum rates of oxidation was longer for fructose. The maximum rates of oxidation were significantly higher when exogenous glucose was administered as an aqueous solution (122 nmol min(-1)), rather than as an oil suspension (93 nmol min(-1)), supporting our prediction that exogenous lipids negatively influence rates of exogenous glucose oxidation. Dietary fatty acids had the lowest maximum rates of oxidation (2-6 nmol min(-1)), and differed significantly in the extent to which each was oxidized, with 0.73%, 0.63% and 0.21% of palmitic, oleic and stearic acid tracers oxidized, respectively.

  10. Degradation of trans-ferulic acid in acidic aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton.

    PubMed

    Flores, Nelly; Sirés, Ignasi; Garrido, José Antonio; Centellas, Francesc; Rodríguez, Rosa María; Cabot, Pere Lluís; Brillas, Enric

    2016-12-01

    Solutions of pH 3.0 containing trans-ferulic acid, a phenolic compound in olive oil mill wastewater, have been comparatively degraded by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Trials were performed with a BDD/air-diffusion cell, where oxidizing OH was produced from water discharge at the BDD anode and/or in the solution bulk from Fenton's reaction between cathodically generated H2O2 and added catalytic Fe(2+). The substrate was very slowly removed by AO-H2O2, whereas it was very rapidly abated by EF and PEF, at similar rate in both cases, due to its fast reaction with OH in the bulk. The AO-H2O2 process yielded a slightly lower mineralization than EF, which promoted the accumulation of barely oxidizable products like Fe(III) complexes. In contrast, the fast photolysis of these latter species under irradiation with UVA light in PEF led to an almost total mineralization with 98% total organic carbon decay. The effect of current density and substrate concentration on the performance of all treatments was examined. Several solar PEF (SPEF) trials showed its viability for the treatment of wastewater containing trans-ferulic acid at larger scale. Four primary aromatic products were identified by GC-MS analysis of electrolyzed solutions, and final carboxylic acids like fumaric, acetic and oxalic were detected by ion-exclusion HPLC. A reaction sequence for trans-ferulic acid mineralization involving all the detected products is finally proposed. PMID:26691522

  11. Degradation of trans-ferulic acid in acidic aqueous medium by anodic oxidation, electro-Fenton and photoelectro-Fenton.

    PubMed

    Flores, Nelly; Sirés, Ignasi; Garrido, José Antonio; Centellas, Francesc; Rodríguez, Rosa María; Cabot, Pere Lluís; Brillas, Enric

    2016-12-01

    Solutions of pH 3.0 containing trans-ferulic acid, a phenolic compound in olive oil mill wastewater, have been comparatively degraded by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Trials were performed with a BDD/air-diffusion cell, where oxidizing OH was produced from water discharge at the BDD anode and/or in the solution bulk from Fenton's reaction between cathodically generated H2O2 and added catalytic Fe(2+). The substrate was very slowly removed by AO-H2O2, whereas it was very rapidly abated by EF and PEF, at similar rate in both cases, due to its fast reaction with OH in the bulk. The AO-H2O2 process yielded a slightly lower mineralization than EF, which promoted the accumulation of barely oxidizable products like Fe(III) complexes. In contrast, the fast photolysis of these latter species under irradiation with UVA light in PEF led to an almost total mineralization with 98% total organic carbon decay. The effect of current density and substrate concentration on the performance of all treatments was examined. Several solar PEF (SPEF) trials showed its viability for the treatment of wastewater containing trans-ferulic acid at larger scale. Four primary aromatic products were identified by GC-MS analysis of electrolyzed solutions, and final carboxylic acids like fumaric, acetic and oxalic were detected by ion-exclusion HPLC. A reaction sequence for trans-ferulic acid mineralization involving all the detected products is finally proposed.

  12. 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.

  13. 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

  14. 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)...

  15. 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)...

  16. Monoclinic hafnium oxynitride supported on reduced graphene oxide to catalyse the oxygen reduction reaction in acidic media.

    PubMed

    Chisaka, M; Sasaki, H; Muramoto, H

    2014-10-14

    Monoclinic HfO2 nanoparticles were doped with nitrogen via hydrothermal treatment that avoided high-cost pyrolysis with NH3 gas in order to develop a novel oxygen reduction reaction catalyst for use in acidic media. Catalyst size reduction was achieved using a reduced graphene oxide support, and activity above 0.8 V was obtained.

  17. Acid pre-treatment method for in situ ore leaching

    DOEpatents

    Mallon, R.G.; Braun, R.L.

    1975-10-28

    An acid leaching method is described for the recovery of a desired element from a subterranean rubblized body of primary ore containing the element and also having associated therewith a carbonate mineral wherein the rubblized ore body is flooded with an aqueous acidic solution in order to release carbon dioxide from the associated carbonate mineral. After a substantial portion of the available carbon dioxide is released and removed from the ore body, as by venting to the atmosphere, an oxidizing gas is introduced into the flooded, rubblized ore to oxidize the ore and form an acid leach solution effective in the presence of the dissolved oxidizing gas to dissolve the ore and cause the desired element to go into solution. The leach solution is then circulated to the surface where the metal values are recovered therefrom.

  18. Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

    SciTech Connect

    Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi; Sakamoto, Tomoya; Takahashi, Nobuyuki; Kawada, Teruo

    2011-04-22

    Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a human adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected

  19. Increasing mitochondrial muscle fatty acid oxidation induces skeletal muscle remodeling toward an oxidative phenotype.

    PubMed

    Hénique, Carole; Mansouri, Abdelhak; Vavrova, Eliska; Lenoir, Véronique; Ferry, Arnaud; Esnous, Catherine; Ramond, Elodie; Girard, Jean; Bouillaud, Frédéric; Prip-Buus, Carina; Cohen, Isabelle

    2015-06-01

    Adult skeletal muscle is a dynamic, remarkably plastic tissue, which allows myofibers to switch from fast/glycolytic to slow/oxidative types and to increase mitochondrial fatty acid oxidation (mFAO) capacity and vascularization in response to exercise training. mFAO is the main muscle energy source during endurance exercise, with carnitine palmitoyltransferase 1 (CPT1) being the key regulatory enzyme. Whether increasing muscle mFAO affects skeletal muscle physiology in adulthood actually remains unknown. To investigate this, we used in vivo electrotransfer technology to express in mouse tibialis anterior (TA), a fast/glycolytic muscle, a mutated CPT1 form (CPT1mt) that is active but insensitive to malonyl-CoA, its physiologic inhibitor. In young (2-mo-old) adult mice, muscle CPT1mt expression enhanced mFAO (+40%), but also increased the percentage of oxidative fibers (+28%), glycogen content, and capillary-to-fiber density (+45%). This CPT1mt-induced muscle remodeling, which mimicked exercise-induced oxidative phenotype, led to a greater resistance to muscle fatigue. In the context of aging, characterized by sarcopenia and reduced oxidative capacity, CPT1mt expression in TAs from aged (20-mo-old) mice partially reversed aging-associated sarcopenia and fiber-type transition, and increased muscle capillarity. These findings provide evidence that mFAO regulates muscle phenotype and may be a potential target to combat age-related decline in muscle function. PMID:25713059

  20. BACE1 activity impairs neuronal glucose oxidation: rescue by beta-hydroxybutyrate and lipoic acid

    PubMed Central

    Findlay, John A.; Hamilton, David L.; Ashford, Michael L. J.

    2015-01-01

    Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer's disease (AD) pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y) cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD. PMID:26483636

  1. ω-Alkynyl Lipid Surrogates for Polyunsaturated Fatty Acids: Free Radical and Enzymatic Oxidations

    PubMed Central

    2015-01-01

    Lipid and lipid metabolite profiling are important parameters in understanding the pathogenesis of many diseases. Alkynylated polyunsaturated fatty acids are potentially useful probes for tracking the fate of fatty acid metabolites. The nonenzymatic and enzymatic oxidations of ω-alkynyl linoleic acid and ω-alkynyl arachidonic acid were compared to that of linoleic and arachidonic acid. There was no detectable difference in the primary products of nonenzymatic oxidation, which comprised cis,trans-hydroxy fatty acids. Similar hydroxy fatty acid products were formed when ω-alkynyl linoleic acid and ω-alkynyl arachidonic acid were reacted with lipoxygenase enzymes that introduce oxygen at different positions in the carbon chains. The rates of oxidation of ω-alkynylated fatty acids were reduced compared to those of the natural fatty acids. Cyclooxygenase-1 and -2 did not oxidize alkynyl linoleic but efficiently oxidized alkynyl arachidonic acid. The products were identified as alkynyl 11-hydroxy-eicosatetraenoic acid, alkynyl 11-hydroxy-8,9-epoxy-eicosatrienoic acid, and alkynyl prostaglandins. This deviation from the metabolic profile of arachidonic acid may limit the utility of alkynyl arachidonic acid in the tracking of cyclooxygenase-based lipid oxidation. The formation of alkynyl 11-hydroxy-8,9-epoxy-eicosatrienoic acid compared to alkynyl prostaglandins suggests that the ω-alkyne group causes a conformational change in the fatty acid bound to the enzyme, which reduces the efficiency of cyclization of dioxalanyl intermediates to endoperoxide intermediates. Overall, ω-alkynyl linoleic acid and ω-alkynyl arachidonic acid appear to be metabolically competent surrogates for tracking the fate of polyunsaturated fatty acids when looking at models involving autoxidation and oxidation by lipoxygenases. PMID:25034362

  2. Improved oxides for production of lead/acid battery plates

    NASA Astrophysics Data System (ADS)

    Boden, D. P.

    For many years, the plates of lead/acid batteries have been produced from leady oxide, a mixture of finely divided lead (`free-lead') and lead monoxide. Although this material is generally satisfactory, it suffers from the disadvantages that it is variable in composition and requires complicated and lengthy processing after pasting to remove the residual free-lead. Plates made from leady oxide also require cycling before they achieve their full performance, and this can result in either depressed initial capacity or additional processing cost. There is a growing trend towards the use of pure lead monoxide ( β-PbO) for the production of positive plates. This material is particularly valuable in valve-regulated batteries where cell-to-cell uniformity is essential for proper control of battery performance. It also reduces processing cost since it does not require time-consuming curing to remove free-lead. Red lead (Pb 3O 4) is also being more widely used in industrial batteries since it reduces formation time, and improves initial and high-rate performance. The methods of production of leady oxide, β-PbO and red lead are briefly reviewed and the characteristics of battery-grade materials are described. Particular emphasis is placed on optimum particle-size distribution, and how this can affect the battery performance. The benefits in processing and performance are described together with information on how pure litharge and red lead are used in battery plates.

  3. 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.

  4. 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

  5. Caffeic acid-coated multifunctional magnetic nanoparticles for the treatment and bimodal imaging of tumours.

    PubMed

    Lee, Jun; Kim, Kyoung Sub; Na, Kun

    2016-07-01

    Accurate theragnosis of tumour is essential for improving the life rate of tumour patients. Superparamagnetic iron oxide nanoparticles (SPIONs) have been used as both diagnostic and therapeutic agents. However, their application is often limited because of a lack of water solubility, lack of cancer treatment efficacy, and ineffective targeting of tumour cells. In this report, a double ligand (caffeic acid-polyethylene glycol-folic acid; FA-PEG-CA, caffeic acid-polyethylene glycol-pheophorbide-a; PheoA-PEG-CA) coated iron oxide nanoparticle has been fabricated that overcomes the limitations of conventional SPION. Photosensitizer and tumour targeting ligands were coated on SPION using a ligand-substitution method. We confirmed the successful substitution of oleic acid ligands with FA-PEG-CA and PheoA-PEG-CA ligands by FT-IR spectroscopy. The caffeic acid coated iron oxide nanoparticles (CAMNPs) also demonstrated high water solubility in an aqueous environment and folate-mediated active tumour targeting. The water solubility of CAMNPs was evaluated by DLS measurement and TEM images. The cytotoxicity of CAMNPs increased two-fold in MDA-MB-231 cells at a laser irradiation condition. The fabricated CAMNPs retained their ability to function as both MRI diagnostic and tumour-selective therapeutic agents. These results suggest that these efficient characteristics of CAMNPs can be incorporated into applications, thus enhancing the efficacy of clinical cancer treatment. PMID:27107705

  6. 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

  7. Relief of delayed oxidative stress by ascorbic acid can suppress radiation-induced cellular senescence in mammalian fibroblast cells.

    PubMed

    Kobashigawa, Shinko; Kashino, Genro; Mori, Hiromu; Watanabe, Masami

    2015-03-01

    Ionizing radiation-induced cellular senescence is thought to be caused by nuclear DNA damage that cannot be repaired. However, here we found that radiation induces delayed increase of intracellular oxidative stress after irradiation. We investigated whether the relief of delayed oxidative stress by ascorbic acid would suppress the radiation-induced cellular senescence in Syrian golden hamster embryo (SHE) cells. We observed that the level of oxidative stress was drastically increased soon after irradiation, then declined to the level in non-irradiated cells, and increased again with a peak on day 3 after irradiation. We found that the inductions of cellular senescence after X-irradiation were reduced along with suppression of the delayed induction of oxidative stress by treatment with ascorbic acid, but not when oxidative stress occurred immediately after irradiation. Moreover, treatment of ascorbic acid inhibited p53 accumulation at 3 days after irradiation. Our data suggested a delayed increase of intracellular oxidative stress levels plays an important role in the process of radiation-induced cellular senescence by p53 accumulation.

  8. 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

  9. Acid mine water aeration and treatment system

    DOEpatents

    Ackman, Terry E.; Place, John M.

    1987-01-01

    An in-line system is provided for treating acid mine drainage which basically comprises the combination of a jet pump (or pumps) and a static mixer. The jet pump entrains air into the acid waste water using a Venturi effect so as to provide aeration of the waste water while further aeration is provided by the helical vanes of the static mixer. A neutralizing agent is injected into the suction chamber of the jet pump and the static mixer is formed by plural sections offset by 90 degrees.

  10. Oxidized Docosahexaenoic Acid Species and Lipid Peroxidation Products Increase Amyloidogenic Amyloid Precursor Protein Processing.

    PubMed

    Grimm, Marcus O W; Haupenthal, Viola J; Mett, Janine; Stahlmann, Christoph P; Blümel, Tamara; Mylonas, Nadine T; Endres, Kristina; Grimm, Heike S; Hartmann, Tobias

    2016-01-01

    One of the main characteristics of Alzheimer's disease (AD) is the β-amyloid peptide (Aβ) generated by β- and γ-secretase processing of the amyloid precursor protein (APP). Previously it has been demonstrated that polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), are associated with a reduced risk of AD caused by decreased Aβ production. However, in epidemiological studies and nutritional approaches, the outcomes of DHA-dependent treatment were partially controversial. PUFAs are very susceptible to reactive oxygen species and lipid peroxidation, which are increased during disease pathology. In line with published results, lipid peroxidation was elevated in human postmortem AD brains; especially 4-hydroxy-nonenal (HNE) was increased. To investigate whether lipid peroxidation is only a consequence or might also influence the processes leading to AD, we analyzed 7 different oxidized lipid species including 5 oxidized DHA derivatives and the lipid peroxidation products of ω-3 and ω-6 PUFAs, HNE and 4-hydroxy-hexenal, in human neuroblastoma cells and mouse mixed cortical neurons. In the presence of oxidized lipids Aβ and soluble β-secreted APP levels were elevated, whereas soluble α-secreted APP was decreased, suggesting a shift from the nonamyloidogenic to the amyloidogenic pathway of APP processing. Furthermore, β- and γ-secretase activity was increased by oxidized lipids via increased gene expression and additionally by a direct effect on β-secretase activity. Importantly, only 1% oxidized DHA was sufficient to revert the protective effect of DHA and to significantly increase Aβ production. Therefore, our results emphasize the need to prevent DHA from oxidation in nutritional approaches and might help explain the divergent results of clinical DHA studies. PMID:26642316

  11. 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

  12. 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.

  13. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress.

    PubMed

    Martinez, Vicente; Mestre, Teresa C; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A; Mittler, Ron; Rivero, Rosa M

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance.

  14. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress

    PubMed Central

    Martinez, Vicente; Mestre, Teresa C.; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A.; Mittler, Ron; Rivero, Rosa M.

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance. PMID:27379130

  15. Accumulation of Flavonols over Hydroxycinnamic Acids Favors Oxidative Damage Protection under Abiotic Stress.

    PubMed

    Martinez, Vicente; Mestre, Teresa C; Rubio, Francisco; Girones-Vilaplana, Amadeo; Moreno, Diego A; Mittler, Ron; Rivero, Rosa M

    2016-01-01

    Efficient detoxification of reactive oxygen species (ROS) is thought to play a key role in enhancing the tolerance of plants to abiotic stresses. Although multiple pathways, enzymes, and antioxidants are present in plants, their exact roles during different stress responses remain unclear. Here, we report on the characterization of the different antioxidant mechanisms of tomato plants subjected to heat stress, salinity stress, or a combination of both stresses. All the treatments applied induced an increase of oxidative stress, with the salinity treatment being the most aggressive, resulting in plants with the lowest biomass, and the highest levels of H2O2 accumulation, lipid peroxidation, and protein oxidation. However, the results obtained from the transcript expression study and enzymatic activities related to the ascorbate-glutathione pathway did not fully explain the differences in the oxidative damage observed between salinity and the combination of salinity and heat. An exhaustive metabolomics study revealed the differential accumulation of phenolic compounds depending on the type of abiotic stress applied. An analysis at gene and enzyme levels of the phenylpropanoid metabolism concluded that under conditions where flavonols accumulated to a greater degree as compared to hydroxycinnamic acids, the oxidative damage was lower, highlighting the importance of flavonols as powerful antioxidants, and their role in abiotic stress tolerance. PMID:27379130

  16. Influence of Endodontic Treatment on Systemic Oxidative Stress

    PubMed Central

    Inchingolo, Francesco; Marrelli, Massimo; Annibali, Susanna; Cristalli, Maria Paola; Dipalma, Gianna; Inchingolo, Alessio Danilo; Palladino, Antonio; Inchingolo, Angelo Michele; Gargari, Marco; Tatullo, Marco

    2014-01-01

    Introduction: An increased production of oxidizing species related to reactive oral diseases, such as chronic apical periodontitis, could have systemic implications such as an increase in cardiovascular morbidity. Based on this consideration, we conducted a prospective study to assess whether subjects affected by chronic periodontitis presented with higher values of oxidative stress than reference values before endodontic treatment, and whether endodontic treatment can reduce the oxidative imbalance and bring it back to normal in these subjects. Materials and methods: The authors recruited 2 groups of patients from private studies and dental clinics: these patients were recruited randomly. The oxidative balance in both patients with chronic apical periodontitis (CAP) and healthy control patients was determined by measuring the oxidant status, using an identification of the reactive oxygen metabolites (d-ROMs) test, while the antioxidant status in these patients was determined using a biological antioxidant potential (BAP) test. Both these tests were carried on plasma samples taken from enrolled patients. Values were measured both before the endodontic treatment of the patients with chronic apical periodontitis, and 30 and 90 days after treatment, and compared to those obtained from healthy control patients. Results: It was found that, on recruitment, the patients with chronic apical periodontitis exhibited significantly higher levels of oxidative stress than control patients, as determined by the d-ROMs and BAP tests. Furthermore, the d-ROMs test values were shown to decrease and the BAP test values to increase over time in patients with chronic apical periodontitis following endodontic therapy. As the levels of oxidative stress in these patients tended to reduce and return to normal by 90 days following treatment. Conclusions: This study has demonstrated a positive association between chronic apical periodontitis and oxidative stress. Subjects affected by chronic

  17. Parallel activation of mitochondrial oxidative metabolism with increased cardiac energy expenditure is not dependent on fatty acid oxidation in pigs

    PubMed Central

    Zhou, Lufang; Cabrera, Marco E; Huang, Hazel; Yuan, Celvie L; Monika, Duda K; Sharma, Naveen; Bian, Fang; Stanley, William C

    2007-01-01

    Steady state concentrations of ATP and ADP in vivo are similar at low and high cardiac workloads; however, the mechanisms that regulate the activation of substrate metabolism and oxidative phosphorylation that supports this stability are poorly understood. We tested the hypotheses that (1) there is parallel activation of mitochondrial and cytosolic dehydrogenases in the transition from low to high workload, which increases NADH/NAD+ ratio in both compartments, and (2) this response does not require an increase in fatty acid oxidation (FAO). Anaesthetized pigs were subjected to either sham treatment, or an abrupt increase in cardiac workload for 5 min with dobutamine infusion and aortic constriction. Myocardial oxygen consumption and FAO were increased 3- and 2-fold, respectively, but ATP and ADP concentrations did not change. NADH-generating pathways were rapidly activated in both the cytosol and mitochondria, as seen in a 40% depletion in glycogen stores, a 3.6-fold activation of pyruvate dehydrogenase, and a 50% increase in tissue NADH/NAD+. Simulations from a multicompartmental computational model of cardiac energy metabolism predicted that parallel activation of glycolysis and mitochondrial metabolism results in an increase in the NADH/NAD+ ratio in both cytosol and mitochondria. FAO was blocked by 75% in a third group of pigs, and a similar increase in and the NAHD/NAD+ ratio was observed. In conclusion, in the transition to a high cardiac workload there is rapid parallel activation of substrate oxidation that results in an increase in the NADH/NAD+ ratio. PMID:17185335

  18. 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.

  19. Degradation of azo dyes by oxidative processes--laccase and ultrasound treatment.

    PubMed

    Tauber, Michael M; Gübitz, Georg M; Rehorek, Astrid

    2008-07-01

    Azo dyes are of synthetic origin and their environmental fate is not well understood. They are resistant to direct aerobic bacterial degradation and form potentially carcinogenic aromatic amines by reduction of the azo group. This study shows that applying the oxidative processes of enzymatic treatment with laccase and ultrasound treatment, both alone and in combination, leads to dye degradation. Laccase treatment degraded both Acid Orange and Direct Blue dyes within 1-5 h but failed in the case of Reactive dyes, whereas ultrasound degraded all the dyes investigated (3-15 h). When applied as multi-stage combinations the treatments showed synergistic effects for dye degradation compared with individual treatments. Bulk light absorption (UV-Vis) and ion pairing HPLC were used for process monitoring. Additionally, mass spectrometry was used to elucidate the structures of intermediates arising from ultrasound treatment.

  20. Iron sulfide oxidation and the chemistry of acid generation

    SciTech Connect

    Sullivan, P.J.; Yelton, J.L. ); Reddy, K.J. )

    1988-06-01

    Acid mine drainage, produced from the oxidation of iron sulfides, often contains elevated levels of dissolved aluminum (Al), iron (Fe), and sulfate (SO{sub 4}) 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% pyrite) and a Chattanooga Shale (1.5% pyrite) were used. 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 Fe{sup 3+}, Fe{sup 2+}, Al{sup 3+}, and SO{sub 4}{sup 2{minus}} 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 Fe{sup 3+} and Fe{sup 2+} activities appeared to be controlled by amorphous Fe(OH){sub 3} solid phase above a pH of 6.0 and below pe + pH 11.0. The Fe{sup 3+}, Fe{sup 2+}, and SO{sub 4}{sup 2{minus}} activities reached saturation with respect to FeOHSO{sub 4} 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, Fe{sup 2+}, Fe{sup 3+}, and SO{sub 4}{sup 2{minus}} activities are supported by FeSO{sub 4}{center dot}7H{sub 2}O solid phase. Above a pH of 6.0, the Al{sup 3+} activity showed an equilibrium with amorphous Al(OH){sub 3} solid phase. Below pH 6.0, Al{sup 3+} and SO{sub 4}{sup 2{minus}} activities are regulated by the AlOHSO{sub 4} 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.

  1. Changes of turbidity during the phenol oxidation by photo-Fenton treatment.

    PubMed

    Villota, Natalia; Camarero, Luis M; Lomas, Jose M; Perez, Jonatan

    2014-11-01

    Turbidity presented by phenol solutions oxidized with Fenton reagent shows the tendency of a first order intermediate kinetics. Thus, turbidity can be considered a representative parameter of the presence of intermediate oxidation species, which are generated along the decomposition of toxic and reluctant contaminants, such as phenol. Moreover, that parameter presents a linear dependence with the catalyst dosage, but is also determined by the initial contaminant load. When analyzing the oxidation mechanism of phenol, it is found that the maximum turbidity occurs when the treatment is carried out at oxidant to phenol molar ratios R = 4.0. These oxidation conditions correspond to the presence of a reaction mixture mainly composed of dihydroxylated rings, precursors of the muconic acid formation. The oxidation via "para" comprises the formation reactions of charge transfer complexes (quinhydrone), between the para-dihydroxylated intermediates (hydroquinone) and the para-substituted quinones (p-benzoquinone), which are quite unstable and reactive species, quickly decomposed into hydroxyhydroquinones. Working with oxidant ratios up to R = 6.0, the maximum observed value of turbidity in the oxidized solutions is kept almost constant. It is found that, in these conditions, the pyrogallol formation is maximal, what is generated through the degradation of ortho-species (catechol and ortho-benzoquinone) and meta-substituted (resorcinol). Operating with ratios over R = 6.0, these intermediates are decomposed into biodegradable acids, generating lower turbidity in the solution. Then, the residual turbidity is a function of the molar ratio of the ferrous ions vs. moles of oxidant utilized in the essays, that lets to estimate the stoichiometric dosage of catalyst as 20 mg/L at pH = 3.0, whereas operating in stoichiometric conditions, R = 14.0, the residual turbidity of water results almost null.

  2. Mineralization of salicylic acid in acidic aqueous medium by electrochemical advanced oxidation processes using platinum and boron-doped diamond as anode and cathodically generated hydrogen peroxide.

    PubMed

    Guinea, Elena; Arias, Conchita; Cabot, Pere Lluís; Garrido, José Antonio; Rodríguez, Rosa María; Centellas, Francesc; Brillas, Enric

    2008-01-01

    Solutions containing 164 mg L(-1) salicylic acid of pH 3.0 have been degraded by electrochemical advanced oxidation processes such as anodic oxidation, anodic oxidation with electrogenerated H(2)O(2), electro-Fenton, photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Their oxidation power has been comparatively studied in a one-compartment cell with a Pt or boron-doped diamond (BDD) anode and a graphite or O(2)-diffusion cathode. In the three latter procedures, 0.5mM Fe(2+) is added to the solution to form hydroxyl radical (()OH) from Fenton's reaction between Fe(2+) and H(2)O(2) generated at the O(2)-diffusion cathode. Total mineralization is attained for all methods with BDD and for photoelectro-Fenton and solar photoelectro-Fenton with Pt. The poor decontamination achieved in anodic oxidation and electro-Fenton with Pt is explained by the slow removal of most pollutants by ()OH formed from water oxidation at the Pt anode in comparison to their quick destruction with ()OH produced at BDD. ()OH generated from Fenton's reaction oxidizes rapidly all aromatic pollutants, but it cannot destroy final Fe(III)-oxalate complexes. Solar photoelectro-Fenton treatments always yield quicker degradation rate due to the very fast photodecarboxylation of these complexes by UVA irradiation supplied by solar light. The effect of current density on the degradation rate, efficiency and energy cost of all methods is examined. The salicylic acid decay always follows a pseudo-first-order kinetics. 2,3-Dihydroxybenzoic, 2,5-dihydroxybenzoic, 2,6-dihydroxybenzoic, alpha-ketoglutaric, glycolic, glyoxylic, maleic, fumaric, malic, tartronic and oxalic acids are detected as oxidation products. A general reaction sequence for salicylic acid mineralization considering all these intermediates is proposed.

  3. 300 Area waste acid treatment system closure plan. Revision 1

    SciTech Connect

    1996-03-01

    This section provides a description of the Hanford Site, identifies the proposed method of 300 Area Waste Acid Treatment System (WATS) closure, and briefly summarizes the contents of each chapter of this plan.

  4. 15. INTERIOR MIDDLE BAY DETAIL VIEW, FACING WEST. ACID TREATMENT, ...

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

    15. INTERIOR MIDDLE BAY DETAIL VIEW, FACING WEST. ACID TREATMENT, CUTTING EQUIPMENT, LOCKERS ABANDONED ON SITE. TRACKS FOR MOVEMENT OF MATERIALS VISIBLE HANGING FROM CEILING. - NASA Industrial Plant, Missile Research Laboratory, 12214 Lakewood Boulevard, Downey, Los Angeles County, CA

  5. 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.

  6. [Advances in the research of treatment of hydrofluoric acid burn].

    PubMed

    Wang, Xin-gang; Zhang, Yuan-hai; Han, Chun-mao

    2013-08-01

    Hydrofluoric acid (HF) is one of the most common inorganic acids used widely in industrial circle. HF not only causes cutaneous burn, but also induces systemic toxicity by its unique injury mechanism. Accurate and timely diagnosis and treatment are critical after HF burns. To date, the strategies for treating HF burns have been developed, mainly including topical treatments and systematic support. However, there is no standard treatment strategy with wide acceptance in the world. This paper presents a comprehensive overview of the advances in the research of strategies for the treatment of HF burns.

  7. The effect of acid-base properties of supported molybdenum oxide in propylene oxidation

    SciTech Connect

    Desikan, A.N.; Zhang, W.; Oyama, S.T.

    1995-12-01

    Samples of molybdenum oxide supported on SiO{sub 2}, Al{sub 2}O{sub 3}, and TiO{sub 2} were used to study the effect of loading and support on propylene oxidation. The samples were characterized by oxygen chemisorption, temperature programmed reduction (TPR), and temperature programmed surface reaction (TPSR) of adsorbed ethanol. Oxygen chemisorption and TPR results indicated that the molybdenum oxide-support interaction increased in the order SiO{sub 2} < Al{sub 2}O{sub 3} < TiO{sub 2}. TPSR of adsorbed ethanol was used to characterize the acid-base properties of the catalysts. These properties played an important role in the surface reactions of the highly dispersed low-loading samples and resulted in the formation of oxidation products depending on the supports (acrolein on MoO{sub 3}/SiO{sub 2}, acetaldehyde on MoO{sub 3}/Al{sub 2}O{sub 3}, and acetone on MoO{sub 3}/TiO{sub 2}). In higher loading samples these differences were reduced as support effects became less important. 80 refs., 9 figs., 1 tab.

  8. Omega-3 fatty acids in the treatment of psychiatric disorders.

    PubMed

    Peet, Malcolm; Stokes, Caroline

    2005-01-01

    The importance of omega-3 fatty acids for physical health is now well recognised and there is increasing evidence that omega-3 fatty acids may also be important to mental health. The two main omega-3 fatty acids in fish oil, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have important biological functions in the CNS. DHA is a major structural component of neuronal membranes, and changing the fatty acid composition of neuronal membranes leads to functional changes in the activity of receptors and other proteins embedded in the membrane phospholipid. EPA has important physiological functions that can affect neuronal activity. Epidemiological studies indicate an association between depression and low dietary intake of omega-3 fatty acids, and biochemical studies have shown reduced levels of omega-3 fatty acids in red blood cell membranes in both depressive and schizophrenic patients. Five of six double-blind, placebo-controlled trials in schizophrenia, and four of six such trials in depression, have reported therapeutic benefit from omega-3 fatty acids in either the primary or secondary statistical analysis, particularly when EPA is added on to existing psychotropic medication. Individual clinical trials have suggested benefits of EPA treatment in borderline personality disorder and of combined omega-3 and omega-6 fatty acid treatment for attention-deficit hyperactivity disorder. The evidence to date supports the adjunctive use of omega-3 fatty acids in the management of treatment unresponsive depression and schizophrenia. As these conditions are associated with increased risk of coronary heart disease and diabetes mellitus, omega-3 fatty acids should also benefit the physical state of these patients. However, as the clinical research evidence is preliminary, large, and definitive randomised controlled trials similar to those required for the licensing of any new pharmacological treatment are needed.

  9. Treatment of effluents from uranium oxide production.

    PubMed

    Ladeira, A C Q; Gonçalves, J S; Morais, C A

    2011-01-01

    The nuclear fuel cycle comprises a series of industrial processes which involve the production of electricity from uranium in nuclear power reactors. In Brazil the conversion of uranium hexafluoride (UF6) into uranium dioxide (UO2) takes place in Resende (RJ) at the Nuclear Fuel Factory (FCN). The process generates liquid effluents with significant concentrations of uranium, which might be treated before being discharged into the environment. This study investigates the recovery of uranium from three distinct liquid effluents: one with a high carbonate content and the other with an elevated fluoride concentration. This paper also presents a study on carbonate removal from an effluent that consists of a water-methanol solution generated during the filtration of the yellow cake (ammonium uranyl tricarbonate). The results showed that: (1) the uranium from the carbonated solution can be recovered through the ion exchange technique using the strong base anionic resin IRA 910-U, as the carbonate has been removed as CO2 after heating; (2) the most suitable technique to recover uranium from the fluoride solution is its precipitation as (NH4)2UO4F2 (ammonium fluorouranate peroxide), (3) the solution free of carbonate can be added to the fluoride solution and the uranium from the final solution can be recovered by precipitation as ammonium fluorouranate peroxide as well; (4) the carbonate from the water-methanol solution can be recovered as calcium carbonate through the addition of calcium chloride, or it can be recovered as ammonium sulphate through the addition of sulphuric acid. The ammonium sulphate product can be used as a fertilizer.

  10. 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.

  11. [Recommendations for inhaled nitric oxide treatment in the newborn diseases].

    PubMed

    2001-09-01

    The recommendations in this document highlight current indications for inhaled nitric oxide (iNO) treatment in the newborn by clearly differentiating between those that are supported by scientific evidence and those for which evidence is still lacking. However, the use of this treatment in preterm infants and in those with congenital heart disease has not yet been scientifically approved. We discuss the methodology, dosage and adverse effects of iNO administration, as well as the reasons for its ineffectiveness.

  12. 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

  13. 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

  14. 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.

  15. 300 Area waste acid treatment system closure plan

    SciTech Connect

    LUKE, S.N.

    1999-05-17

    The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOERL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion includes closure plan documentation submitted for individual, treatment, storage, and/or disposal units undergoing closure, such as the 300 Area Waste Acid Treatment System. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Whenever appropriate, 300 Area Waste Acid Treatment System documentation makes cross-reference to the General Information Portion, rather than duplicating text. This 300 Area Waste Acid Treatment System Closure Plan (Revision 2) includes a Hanford Facility Dangerous Waste Permit Application, Part A, Form 3. Information provided in this closure plan is current as of April 1999.

  16. Analysis of iron oxide precipitates in constructed mine wastewater treatments

    SciTech Connect

    Partezana, J.M.

    1996-10-01

    The purpose or this research project is to characterize iron oxide precipitates collected from abandoned mine drainage (AMD) treatment facilities in order to determine whether these precipitates have possible commercial value. The treatment facilities use constructed wetlands to raise pH levels to near neutral levels and to remove iron and other heavy metals from AMD polluted water. The main commercial value of interest is in the use of pigments in products such as paints, clay and brick. The precipitates arc characterized for composition and quality against natural and synthetic commercial pigment products. Various processing techniques were developed for sample preparation. Analysis tests include: general pigment tests, heavy metals, anions, particle size, and particle composition. Results show that the iron oxide precipitates are chemically similar to the commercial iron oxide but will require additional processing to meet pigment qualifications.

  17. The Effects of Ferulic Acid Against Oxidative Stress and Inflammation in Formaldehyde-Induced Hepatotoxicity.

    PubMed

    Gerin, Fethullah; Erman, Hayriye; Erboga, Mustafa; Sener, Umit; Yilmaz, Ahsen; Seyhan, Hatice; Gurel, Ahmet

    2016-08-01

    This study was designed to elucidate the protective effects of ferulic acid (FA) on formaldehyde-induced hepatotoxicity by measuring some routine biochemical parameters, cytokine levels, and oxidative stress-related parameters in addition to YKL-40 in male Wistar albino rats. Tissue superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activities, and tissue malondialdehyde (MDA) levels were measured. Also, serum YKL-40, TNF-α, IL-6, IL-1β, IL-8, total protein, albumin, total bilirubin concentrations, and AST, ALT, ALP, and LDH activities were measured. Histological specimens were examined in light microscopy. Formaldehyde significantly increased tissue MDA, and serum cytokine levels and also decreased activities of antioxidant enzymes. FA treatment decreased MDA and cytokine levels and increased activities of antioxidant enzymes. FA also alleviated degeneration due to formaldehyde toxicity. We suggested that FA can be used as a promising hepatoprotective agent against formaldehyde toxicity because of the obvious beneficial effects on oxidative stress parameters.

  18. Precipitation of plutonium from acidic solutions using magnesium oxide

    SciTech Connect

    Jones, S.A.

    1994-09-06

    Plutonium (IV) is only marginally soluble in alkaline solution. Precipitation of plutonium using sodium or potassium hydroxide to neutralize acidic solutions produces a gelatinous solid that is difficult to filter and an endpoint that is difficult to control. If the pH of the solution is too high, additional species precipitate producing an increased volume of solids separated. The use of magnesium oxide as a reagent has advantages. It is added as a solid (volume of liquid waste produced is minimized), the pH is self-limiting (pH does not exceed about 8.5), and the solids precipitated are more granular (larger particle size) than those produced using KOH or NaOH. Following precipitation, the raffinate is expected to meet criteria for disposal to tank farms. The solid will be heated in a furnace to dry it and convert any hydroxide salts to the oxide form. The material will be cooled in a desiccator. The material is expected to meet vault storage criteria.

  19. Advanced oxidation processes with coke plant wastewater treatment.

    PubMed

    Krzywicka, A; Kwarciak-Kozłowska, A

    2014-01-01

    The aim of this study was to determine the most efficient method of coke wastewater treatment. This research examined two processes - advanced oxidation with Fenton and photo-Fenton reaction. It was observed that the use of ultraviolet radiation with Fenton process had a better result in removal of impurities.

  20. Detection of oxidative hair treatment using fluorescence microscopy.

    PubMed

    Witt, Silvana; Wunder, Cora; Paulke, Alexander; Verhoff, Marcel A; Schubert-Zsilavecz, Manfred; Toennes, Stefan W

    2016-08-01

    In assessing abstinence from drug or alcohol abuse, hair analysis plays an important role. Cosmetic hair treatment influences the content of deposited drugs which is not always detectable during analysis. Since oxidation of melanin leads to an increase in fluorescence, a microscopic method was developed to distinguish natural from cosmetically treated hair. For validation, natural hair samples were treated with different types of cosmetics and inspected by fluorescence microscopy. Hair samples from 20 volunteers with documented cosmetic treatment and as a proof of concept 100 hair samples from forensic cases were analyzed by this method. Apart from autofluorescence with excitation at 365 nm, no obvious fluorescence was observed in untreated hair samples. Tinting and a natural plant product had no influence on fluorescence, but dyeing procedures including oxidation led to a marked increase in fluorescence. Proof of cosmetic treatment was achieved in hair samples from the 20 volunteers. In 100 forensic cases, 13 samples were characterized as oxidatively treated, which was in accordance with the respective disclosure except for one case where treatment was not admitted. This fluorescence microscopic procedure proved to be fast, easy, and reliable to identify oxidatively treated hair samples, which must be considered especially in evaluating cases of negative drug results. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26359937

  1. Photochemical oxidation of chloride ion by ozone in acid aqueous solution.

    PubMed

    Levanov, Alexander V; Isaykina, Oksana Ya; Amirova, Nazrin K; Antipenko, Ewald E; Lunin, Valerii V

    2015-11-01

    The experimental investigation of chloride ion oxidation under the action of ozone and ultraviolet radiation with wavelength 254 nm in the bulk of acid aqueous solution at pH 0-2 has been performed. Processes of chloride oxidation in these conditions are the same as the chemical reactions in the system O3 - OH - Cl(-)(aq). Despite its importance in the environment and for ozone-based water treatment, this reaction system has not been previously investigated in the bulk solution. The end products are chlorate ion ClO3(-) and molecular chlorine Cl2. The ions of trivalent iron have been shown to be catalysts of Cl(-) oxidation. The dependencies of the products formation rates on the concentrations of O3 and H(+) have been studied. The chemical mechanism of Cl(-) oxidation and Cl2 emission and ClO3(-) formation has been proposed. According to the mechanism, the dominant primary process of chloride oxidation represents the complex interaction with hydroxyl radical OH with the formation of Cl2(-) anion-radical intermediate. OH radical is generated on ozone photolysis in aqueous solution. The key subsequent processes are the reactions Cl2(-) + O3 → ClO + O2 + Cl(-) and ClO + H2O2 → HOCl + HO2. Until the present time, they have not been taken into consideration on mechanistic description and modelling of Cl(-) oxidation. The final products are formed via the reactions 2ClO → Cl2O2, Cl2O2 + H2O → 2H(+) + Cl(-) + ClO3(-) and HOCl + H(+) + Cl(-) ⇄ H2O + Cl2. Some portion of chloride is oxidized directly by O3 molecule with the formation of molecular chlorine in the end.

  2. Photochemical oxidation of chloride ion by ozone in acid aqueous solution.

    PubMed

    Levanov, Alexander V; Isaykina, Oksana Ya; Amirova, Nazrin K; Antipenko, Ewald E; Lunin, Valerii V

    2015-11-01

    The experimental investigation of chloride ion oxidation under the action of ozone and ultraviolet radiation with wavelength 254 nm in the bulk of acid aqueous solution at pH 0-2 has been performed. Processes of chloride oxidation in these conditions are the same as the chemical reactions in the system O3 - OH - Cl(-)(aq). Despite its importance in the environment and for ozone-based water treatment, this reaction system has not been previously investigated in the bulk solution. The end products are chlorate ion ClO3(-) and molecular chlorine Cl2. The ions of trivalent iron have been shown to be catalysts of Cl(-) oxidation. The dependencies of the products formation rates on the concentrations of O3 and H(+) have been studied. The chemical mechanism of Cl(-) oxidation and Cl2 emission and ClO3(-) formation has been proposed. According to the mechanism, the dominant primary process of chloride oxidation represents the complex interaction with hydroxyl radical OH with the formation of Cl2(-) anion-radical intermediate. OH radical is generated on ozone photolysis in aqueous solution. The key subsequent processes are the reactions Cl2(-) + O3 → ClO + O2 + Cl(-) and ClO + H2O2 → HOCl + HO2. Until the present time, they have not been taken into consideration on mechanistic description and modelling of Cl(-) oxidation. The final products are formed via the reactions 2ClO → Cl2O2, Cl2O2 + H2O → 2H(+) + Cl(-) + ClO3(-) and HOCl + H(+) + Cl(-) ⇄ H2O + Cl2. Some portion of chloride is oxidized directly by O3 molecule with the formation of molecular chlorine in the end. PMID:26077317

  3. Palladium nanoparticles synthesized by reducing species generated during a successive acidic/alkaline treatment of sucrose

    NASA Astrophysics Data System (ADS)

    Amornkitbamrung, Lunjakorn; Pienpinijtham, Prompong; Thammacharoen, Chuchaat; Ekgasit, Sanong

    2014-03-01

    Uniform spherical palladium nanoparticles with an average particle size of 4.3 ± 0.5 nm were successfully synthesized by reducing H2PdCl4 with intermediates in situ generated during a successive acidic/alkaline treatment of sucrose. A successive acidic/alkaline treatment plays an important role on converting the non-reducing sucrose into efficient reducing species containing aldehyde functionality. The Benedict's test corroborates the development and vanishing of the in situ generated reducing species upon prolonged degradation. An increase in alkalinity drastically improves the reduction efficiency. ATR FT-IR spectroscopy indicated spontaneous development of carboxylate after the alkaline treatment. Under the employed condition, small organic species with carbonyl groups (aldehyde, acid, and acid salt) were generated through the sucrose degradation before being oxidized to carbonate after an hour of the treatment. Sucrose was completely decomposed into carbonate after a 24-h successive acidic/alkaline treatment. The synthesized palladium nanoparticles express a good catalytic activity in the decolorization process of Congo red by sodium borohydride.

  4. Palladium nanoparticles synthesized by reducing species generated during a successive acidic/alkaline treatment of sucrose.

    PubMed

    Amornkitbamrung, Lunjakorn; Pienpinijtham, Prompong; Thammacharoen, Chuchaat; Ekgasit, Sanong

    2014-03-25

    Uniform spherical palladium nanoparticles with an average particle size of 4.3±0.5 nm were successfully synthesized by reducing H2PdCl4 with intermediates in situ generated during a successive acidic/alkaline treatment of sucrose. A successive acidic/alkaline treatment plays an important role on converting the non-reducing sucrose into efficient reducing species containing aldehyde functionality. The Benedict's test corroborates the development and vanishing of the in situ generated reducing species upon prolonged degradation. An increase in alkalinity drastically improves the reduction efficiency. ATR FT-IR spectroscopy indicated spontaneous development of carboxylate after the alkaline treatment. Under the employed condition, small organic species with carbonyl groups (aldehyde, acid, and acid salt) were generated through the sucrose degradation before being oxidized to carbonate after an hour of the treatment. Sucrose was completely decomposed into carbonate after a 24-h successive acidic/alkaline treatment. The synthesized palladium nanoparticles express a good catalytic activity in the decolorization process of Congo red by sodium borohydride. PMID:24309181

  5. Influence of nitric acid treatment in different media on X-ray structural parameters of coal

    SciTech Connect

    Sudip Maity; Ashim Choudhury

    2008-11-15

    The treatment of coal with nitric acid in aqueous and non-aqueous media introduces changes in the chemical and spatial structure of the organic mass. Four coals of different rank have been treated with nitric acid in aqueous and glacial acetic acid media for assessing the changes in the structural parameters by the X-ray diffraction (XRD) technique. Slow-scan XRD has been performed for the raw and treated coals, and X-ray structural parameters (d002, Lc, and Nc) and aromaticity (fa) have been determined by profile-fitting software. Considerable variation of the structural parameters has been observed with respect to the raw coals. The d002 values have decreased in aqueous medium but increased in acetic acid medium; however, Lc, Nc, and fa values have increased in aqueous medium but decreased in acetic acid medium. It is also observed that considerable oxidation takes place during nitric acid treatment in aqueous medium, but nitration is the predominant phenomenon in acetic acid medium. Disordering of the coal structure increases in acetic acid medium, but a reverse trend is observed in the aqueous medium. As a result, structurally modified coals (SMCs) are derived as new coal-derived substances. 15 refs., 6 figs., 3 tabs.

  6. Mycogenic Mn(II) oxidation promotes remediation of acid mine drainage and other anthropogenically impacted environments

    NASA Astrophysics Data System (ADS)

    Santelli, C. M.; Chaput, D.; Hansel, C. M.; Burgos, W. D.

    2014-12-01

    Manganese is a pollutant in worldwide environments contaminated with metals and organics, such as acid mine drainage (AMD), freshwater ponds, and agricultural waste storage sites. Microorganisms contribute to the removal of dissolved Mn compounds in the environment by promoting Mn(II) oxidation reactions. The oxidation of Mn(II) results in the precipitation of sparingly soluble Mn(IV) oxide minerals, effectively removing the metal from the aqueous milieu (e.g., groundwater or wastewater streams). In recent years, our research has identified a diversity of Mn(II)-oxidizing fungi inhabiting these polluted environments, however their overall contribution to the remediation process in situ remains poorly understood. Here we present results of culture-based and Next Generation Sequencing (NGS) studies in AMD treatment systems actively remediating Mn and other metals where we profile the bacterial, fungal, algal and archaeal communities to determine the overall community diversity and to establish the relative abundance of known Mn(II) oxidizers. A variety of treatment systems with varying Mn-removal efficiencies were sampled to understand the relationship between remediation efficiency and microbial community composition and activity. Targeted-amplicon sequencing of DNA and RNA of the 16S rRNA genes (bacteria and archaea), 23S rRNA genes (algae) and ITS region (fungi) was performed using both 454 pyrosequencing and Illumina platforms. Results showed that only the fungal taxonomic profiles significantly differed between sites that removed the majority of influent Mn and those that did not. Specifically, Ascomycota (which include known Mn(II) oxidizers isolated from these treatment systems) dominated greater efficiency systems whereas less efficient systems were dominated by Basidiomycota. Furthermore, known Mn(II) oxidizers accounted for only a minor proportion of bacterial sequences but a far greater proportion of fungal sequences. These culture-independent studies lend

  7. Ameliorative effects of oleanolic acid on fluoride induced metabolic and oxidative dysfunctions in rat brain: Experimental and biochemical studies.

    PubMed

    Sarkar, Chaitali; Pal, Sudipta; Das, Niranjan; Dinda, Biswanath

    2014-04-01

    Beneficial effects of oleanolic acid on fluoride-induced oxidative stress and certain metabolic dysfunctions were studied in four regions of rat brain. Male Wistar rats were treated with sodium fluoride at a dose of 20 mg/kg b.w./day (orally) for 30 days. Results indicate marked reduction in acidic, basic and neutral protein contents due to fluoride toxicity in cerebrum, cerebellum, pons and medulla. DNA, RNA contents significantly decreased in those regions after fluoride exposure. Activities of proteolytic enzymes (such as cathepsin, trypsin and pronase) were inhibited by fluoride, whereas transaminase enzyme (GOT and GPT) activities increased significantly in brain tissue. Fluoride appreciably elevated brain malondialdehyde level, free amino acid nitrogen, NO content and free OH radical generation. Additionally, fluoride perturbed GSH content and markedly reduced SOD, GPx, GR and CAT activities in brain tissues. Oral supplementation of oleanolic acid (a plant triterpenoid), at a dose of 5mg/kgb.w./day for last 14 days of fluoride treatment appreciably ameliorated fluoride-induced alteration of brain metabolic functions. Appreciable counteractive effects of oleanolic acid against fluoride-induced changes in protein and nucleic acid contents, proteolytic enzyme activities and other oxidative stress parameters indicate that oleanolic acid has potential antioxidative effects against fluoride-induced oxidative brain damage.

  8. Cytoprotective mechanism of ferulic acid against high glucose-induced oxidative stress in cardiomyocytes and hepatocytes

    PubMed Central

    Song, Yuan; Wen, Luona; Sun, Jianxia; Bai, Weibin; Jiao, Rui; Hu, Yunfeng; Peng, Xichun; He, Yong; Ou, Shiyi

    2016-01-01

    Background Ferulic acid (FA), a phenolic acid, is a potential therapy for diabetes mellitus. FA has been shown to protect against hepatic and myocardial injury and oxidative stress in obese rats with late-stage diabetes, but the mechanism of the antioxidative activity of FA is still unclear. Objective The aim of this study was to elucidate whether FA can prevent damage to cardiomyocytes and hepatocytes caused by high glucose (HG)-induced oxidative stress and whether the protection effects of FA on these cells are related to the Keap1-Nrf2-ARE signaling pathways. Design Cells were divided into four groups: a control group (cultured with normal medium), an HG group (medium containing 80 mmol/L glucose), an FA+HG group (medium containing 80 mmol/L glucose and 1, 5, or 10 µg/mL FA), and a dimethylbiguanide (DMBG)+HG group (medium containing 80 mmol/L glucose and 50 µg/mL DMBG). Results FA treatment significantly increased cell viability and significantly decreased cell apoptosis compared with the HG-treated group. Moreover, FA down-regulated the expression of Keap1 protein and up-regulated the expression of Nrf2 protein and gene transcription of HO-1 and glutathione S-transferase (GST) in a dose-dependent manner. Conclusion FA alleviated the HG-induced oxidative stress and decreased cell apoptosis in hepatocytes and cardiomyocytes. These effects were associated with the Keap1-Nrf2-ARE signaling pathway. PMID:26869273

  9. 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.

  10. Influence of cyclopropane fatty acids on heat, high pressure, acid and oxidative resistance in Escherichia coli.

    PubMed

    Chen, Yuan Yao; Gänzle, Michael G

    2016-04-01

    Heat and high pressure resistant strains of Escherichia coli are a challenge to food safety. This study investigated effects of cyclopropane fatty acids (CFAs) on stress tolerance in the heat- and pressure-resistant strain E. coli AW1.7 and the sensitive strain E. coli MG1655. The role of CFAs was explored by disruption of cfa coding for CFA synthase with an in-frame, unmarked deletion method. Both wild-type strains consumed all the unsaturated fatty acids (C16:1 and C18:1) that were mostly converted to CFAs and a low proportion to saturated fatty acid (C16:0). Moreover, E. coli AW1.7 contained a higher proportion of membrane C19:0 cyclopropane fatty acid than E. coli MG1655 (P<0.05). The Δcfa mutant strains did not produce CFAs, and the corresponding substrates C16:1 and C18:1 accumulated in membrane lipids. The deletion of cfa did not alter resistance to H2O2 but increased the lethality of heat, high pressure and acid treatments in E. coli AW1.7, and E. coli MG1655. E. coli AW1.7 and its Δcfa mutant were more resistant to pressure and heat but less resistant to acid stress than E. coli MG1655. Heat resistance of wild-type strains and their Δcfa mutant was also assessed in beef patties grilled to an internal temperature of 71 °C. After treatment, cell counts of wild type strains were higher than those of the Δcfa mutant strains. In conclusion, CFA synthesis in E. coli increases heat, high pressure and acid resistance, and increases heat resistance in food. This knowledge on mechanisms of stress resistance will facilitate the design of intervention methods for improved pathogen control in food production.

  11. Fumaric acid esters: an alternative systemic treatment for psoriasis.

    PubMed

    Ameen, M; Russell-Jones, R

    1999-09-01

    We report the successful clearance of severe chronic plaque psoriasis following treatment with fumaric acid esters (FAE) in two patients who had failed previous systemic therapy. FAE is gaining increasing acceptance for the treatment of psoriasis in countries such as Germany and the Netherlands, but at present remains unlicensed in Britain.

  12. Induction of Arabidopsis tryptophan pathway enzymes and camalexin by amino acid starvation, oxidative stress, and an abiotic elicitor.

    PubMed Central

    Zhao, J; Williams, C C; Last, R L

    1998-01-01

    The tryptophan (Trp) biosynthetic pathway leads to the production of many secondary metabolites with diverse functions, and its regulation is predicted to respond to the needs for both protein synthesis and secondary metabolism. We have tested the response of the Trp pathway enzymes and three other amino acid biosynthetic enzymes to starvation for aromatic amino acids, branched-chain amino acids, or methionine. The Trp pathway enzymes and cytosolic glutamine synthetase were induced under all of the amino acid starvation test conditions, whereas methionine synthase and acetolactate synthase were not. The mRNAs for two stress-inducible enzymes unrelated to amino acid biosynthesis and accumulation of the indolic phytoalexin camalexin were also induced by amino acid starvation. These results suggest that regulation of the Trp pathway enzymes under amino acid deprivation conditions is largely a stress response to allow for increased biosynthesis of secondary metabolites. Consistent with this hypothesis, treatments with the oxidative stress-inducing herbicide acifluorfen and the abiotic elicitor alpha-amino butyric acid induced responses similar to those induced by the amino acid starvation treatments. The role of salicylic acid in herbicide-mediated Trp and camalexin induction was investigated. PMID:9501110

  13. 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

  14. Traumatic Acid Reduces Oxidative Stress and Enhances Collagen Biosynthesis in Cultured Human Skin Fibroblasts.

    PubMed

    Jabłońska-Trypuć, Agata; Pankiewicz, Walentyn; Czerpak, Romuald

    2016-09-01

    Traumatic acid (TA) is a plant hormone (cytokinin) that in terms of chemical structure belongs to the group of fatty acids derivatives. It was isolated from Phaseolus vulgaris. TA activity and its influence on human cells and organism has not previously been the subject of research. The aim of this study was to examine the effects of TA on collagen content and basic oxidative stress parameters, such as antioxidative enzyme activity, reduced glutathione, thiol group content, and lipid peroxidation in physiological conditions. The results show a stimulatory effect of TA on tested parameters. TA caused a decrease in membrane phospholipid peroxidation and exhibited protective properties against ROS production. It also increases protein and collagen biosynthesis and its secretion into the culture medium. The present findings reveal that TA exhibits multiple and complex activity in fibroblast cells in vitro. TA, with its activity similar to unsaturated fatty acids, shows antioxidant and stimulatory effects on collagen biosynthesis. It is a potentially powerful agent with applications in the treatment of many skin diseases connected with oxidative stress and collagen biosynthesis disorders. PMID:27423205

  15. Chronic intake of proanthocyanidins and docosahexaenoic acid improves skeletal muscle oxidative capacity in diet-obese rats.

    PubMed

    Casanova, Ester; Baselga-Escudero, Laura; Ribas-Latre, Aleix; Cedó, Lídia; Arola-Arnal, Anna; Pinent, Montserrat; Bladé, Cinta; Arola, Lluís; Salvadó, M Josepa

    2014-10-01

    Obesity has become a worldwide epidemic. The cafeteria diet (CD) induces obesity and oxidative-stress-associated insulin resistance. Polyunsaturated fatty acids and polyphenols are dietary compounds that are intensively studied as products that can reduce the health complications related to obesity. We evaluate the effects of 21 days of supplementation with grape seed proanthocyanidins extract (GSPE), docosahexaenoic-rich oil (DHA-OR) or both compounds (GSPE+DHA-OR) on skeletal muscle metabolism in diet-obese rats. The supplementation with different treatments did not reduce body weight, although all groups used more fat as fuel, particularly when both products were coadministered; muscle β-oxidation was activated, the mitochondrial functionality and oxidative capacity were higher, and fatty acid uptake gene expressions were up-regulated. In addition to these outcomes shared by all treatments, GSPE reduced insulin resistance and improved muscle status. Both treatments increased 5'-AMP-activated protein kinase (AMPK) phosphorylation, which was consistent with higher plasma adiponectin levels. Moreover, AMPK activation by DHA-OR was also correlated with an up-regulation of peroxisome proliferator-activated receptor alpha (Pparα). GSPE+DHA-OR, in addition to activating AMPK and enhancing fatty acid oxidation, increased the muscle gene expression of uncoupling protein 2 (Ucp2). In conclusion, GSPE+DHA-OR induced modifications that improved muscle status and could counterbalance the deleterious effects of obesity, and such modifications are mediated, at least in part, through the AMPK signaling pathway.

  16. Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes.

    PubMed

    Park, Kyoung Sik

    2010-10-01

    Raspberry ketone (RK) is a natural phenolic compound of the red raspberry. The dietary administration of RK to male mice has been reported to prevent high-fat diet-induced elevation in body weight and to increase lipolysis in white adipocytes. To elucidate a possible mechanism for the antiobesity action of RK, its effects on the expression and the secretion of adiponectin, lipolysis, and fatty acid oxidation in 3T3-L1 were investigated. Treatment with 10 µM of RK increased lipolysis significantly in differentiated 3T3-L1 cells. An immunoassay showed that RK increased both the expression and the secretion of adiponectin, an adipocytokine mainly expressed and secreted by adipose tissue. In addition, treatment with 10 µM of RK increased the fatty acid oxidation and suppressed lipid accumulation in 3T3-L1 adipocytes. These findings suggest that RK holds great promise as an herbal medicine since its biological activities alter the lipid metabolism in 3T3-L1 adipocytes.

  17. A novel method for determining peroxisomal fatty acid β-oxidation.

    PubMed

    Morita, Masashi; Matsumoto, Shun; Okazaki, Airi; Tomita, Kaito; Watanabe, Shiro; Kawaguchi, Kosuke; Minato, Daishiro; Matsuya, Yuji; Shimozawa, Nobuyuki; Imanaka, Tsuneo

    2016-09-01

    The purpose of this study is to establish an assay method to screen for chemical compounds that stimulate peroxisomal fatty acid β-oxidation activity in X-linked adrenoleukodystropy (X-ALD) fibroblasts. In this investigation, we used 12-(1-pyrene)dodecanoic acid (pyrene-C12:0), a fluorescent fatty acid analog, as a substrate for fatty acid β-oxidation. When human skin fibroblasts were incubated with pyrene-C12:0, β-oxidation products such as pyrene-C10:0 and pyrene-C8:0 were generated time-dependently. These β-oxidation products were scarcely detected in the fibroblasts from patients with Zellweger syndrome, a peroxisomal biogenesis disorder. In contrast, in fibroblasts with mitochondrial carnitine-acylcarnitine translocase deficiency, the β-oxidation products were detected at a level similar to control fibroblasts. These results indicate that the β-oxidation of pyrene-C12:0 takes place in peroxisomes, but not mitochondria, so pyrene-C12:0 is useful for measuring peroxisomal fatty acid β-oxidation activity. In X-ALD fibroblasts, the β-oxidation activity for pyrene-C12:0 was approximately 40 % of control fibroblasts, which is consistent with previous results using [1-(14)C]lignoceric acid as the substrate. The present study provides a convenient procedure for screening chemical compounds that stimulate the peroxisomal fatty acid β-oxidation in X-ALD fibroblasts.

  18. Removal and transformation products of ibuprofen obtained during ozone- and ultrasound-based oxidative treatment.

    PubMed

    Yargeau, Viviane; Danylo, Félix

    2015-01-01

    The oxidation of ibuprofen (IBP) in water was evaluated using oxidative treatments: ozonation, sonication, hydrogen peroxide addition and combinations of these processes. After 20 minutes of treatment, ozone coupled with hydrogen peroxide at pH 7, 15 °C, an ozone dose of 16 mg/L and a hydrogen peroxide concentration of 7.1 mg/L was found to have the highest IBP (95%) and chemical oxygen demand (COD) (41%) removals. A synergistic effect was observed for the combined ozonation/sonication process, which might be explained by an improved mass transfer of ozone in the solution due to the presence of ultrasonic pressure waves. Transformation products were detected in the treated solutions. The nature of five of these products was confirmed by liquid chromatography-mass spectrometry (LC-MS), including 4-isobutylacetophenone (4-IBAP), oxo-IBP, 4-acetylbenzoic acid, 4-ethybenzaldehyde and oxalic acid. In addition, COD analyses for each experiment showed that the ratio of %COD removal to %IBP removal was highest with sonication; suggesting that this oxidative process offers other mechanisms of removal which may lead to further degradation of products formed. This study presents the first data on removal of IBP by sonication coupled to ozonation and provides some insight into the potential of this combined treatment approach for the removal of contaminants of emerging concern. PMID:26204083

  19. 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

  20. 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

  1. 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

    2011-10-19

    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.

  2. 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…

  3. 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…

  4. 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

  5. A Combined Supplementation of Omega-3 Fatty Acids and Micronutrients (Folic Acid, Vitamin B12) Reduces Oxidative Stress Markers in a Rat Model of Pregnancy Induced Hypertension

    PubMed Central

    Kemse, Nisha G.; Kale, Anvita A.; Joshi, Sadhana R.

    2014-01-01

    Objectives Our earlier studies have highlighted that an altered one carbon metabolism (vitamin B12, folic acid, and docosahexaenoic acid) is associated with preeclampsia. Preeclampsia is also known to be associated with oxidative stress and inflammation. The current study examines whether maternal folic acid, vitamin B12 and omega-3 fatty acid supplementation given either individually or in combination can ameliorate the oxidative stress markers in a rat model of pregnancy induced hypertension (PIH). Materials and Methods Pregnant Wistar rats were assigned to control and five treatment groups: PIH; PIH + vitamin B12; PIH + folic acid; PIH + Omega-3 fatty acids and PIH + combined micronutrient supplementation (vitamin B12 + folic acid + omega-3 fatty acids). L-Nitroarginine methylester (L-NAME; 50 mg/kg body weight/day) was used to induce hypertension during pregnancy. Blood Pressure (BP) was recorded during pregnancy and dams were dissected at d20 of gestation. Results Animals from the PIH group demonstrated higher (p<0.01 for both) systolic and diastolic BP; lower (p<0.01) pup weight; higher dam plasma homocysteine (p<0.05) and dam and offspring malondialdehyde (MDA) (p<0.01), lower (p<0.05) placental and offspring liver DHA and higher (p<0.01) tumor necrosis factor–alpha (TNF–ά) levels as compared to control. Individual micronutrient supplementation did not offer much benefit. In contrast, combined supplementation lowered systolic BP, homocysteine, MDA and placental TNF-ά levels in dams and liver MDA and protein carbonyl in the offspring as compared to PIH group. Conclusion Key constituents of one carbon cycle (folic acid, vitamin B12 and DHA) may play a role in reducing oxidative stress and inflammation in preeclampsia. PMID:25405347

  6. Anodic Oxidative Modification of Egg White for Heat Treatment.

    PubMed

    Takahashi, Masahito; Handa, Akihiro; Yamaguchi, Yusuke; Kodama, Risa; Chiba, Kazuhiro

    2016-08-31

    A new functionalization of egg white was achieved by an electrochemical reaction. The method involves electron transfer from thiol groups of egg white protein to form disulfide bonds. The oxidized egg white produced less hydrogen sulfide during heat treatment; with sufficient application of electricity, almost no hydrogen sulfide was produced. In addition, gels formed by heating electrochemically oxidized egg white exhibited unique properties, such as a lower gelation temperature and a softened texture, presumably due to protein aggregation and electrochemically mediated intramolecular disulfide bond formation. PMID:27518910

  7. Piroxicam attenuates 3-nitropropionic acid-induced brain oxidative stress and behavioral alteration in mice.

    PubMed

    C, Jadiswami; H M, Megha; Dhadde, Shivsharan B; Durg, Sharanbasappa; Potadar, Pandharinath P; B S, Thippeswamy; V P, Veerapur

    2014-12-01

    3-Nitropropionic acid (3-NP) is a fungal toxin that produces Huntington's disease like symptoms in both animals and humans. Piroxicam, a non-selective cyclooxygenase (COX) inhibitor, used as anti-inflammatory agent and also known to decrease free oxygen radical production. In this study, the effect of piroxicam was evaluated against 3-NP-induced brain oxidative stress and behavioral alteration in mice. Adult male Swiss albino mice were injected with vehicle/piroxicam (10 and 20 mg/kg, i.p.) 30 min before 3-NP challenge (15 mg/kg, i.p.) regularly for 14 days. Body weights of the mice were measured on alternative days of the experiment. At the end of the treatment schedule, mice were evaluated for behavioral alterations (movement analysis, locomotor test, beam walking test and hanging wire test) and brain homogenates were used for the estimation of oxidative stress markers (lipid peroxidation, reduced glutathione and catalase). Administration of 3-NP significantly altered the behavioral activities and brain antioxidant status in mice. Piroxicam, at both the tested doses, caused a significant reversal of 3-NP-induced behavioral alterations and oxidative stress in mice. These findings suggest piroxicam protects the mice against 3-NP-induced brain oxidative stress and behavioral alteration. The antioxidant properties of piroxicam may be responsible for the observed beneficial actions. PMID:25191831

  8. Ascorbic acid enhances oxidative stress tolerance and biological control efficacy of Pichia caribbica against postharvest blue mold decay of apples.

    PubMed

    Li, Chaolan; Zhang, Hongyin; Yang, Qiya; Komla, Mahunu Gustav; Zhang, Xiaoyun; Zhu, Shuyun

    2014-07-30

    The effect of ascorbic acid (VC) on improving oxidative stress tolerance of Pichia caribbica and biocontrol efficacy against blue mold caused by Penicillium expansum on apples was investigated. P. caribbica showed susceptibility to the oxidative stress in vitro test, and 250 μg/mL VC treatment improved its oxidative stress tolerance. The higher viability exhibited by VC-treated yeast was associated with a lower intracellular ROS level. The activities of antioxidant enzymes of P. caribbica were improved by VC treatment, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX). Additionally, VC-treated yeast exhibited greater biocontrol activity against P. expansum and faster growth when stored at 25 and 4 °C, respectively, compared to the performance of the non-VC-treated yeast. In response to the VC treatment under oxidative stress, several differentially expressed proteins were identified in P. caribbica, and most of the poteins were confirmed to be related to basic metabolism. Therefore, the application of ascorbic acid is a useful approach to improve oxidative stress tolerance of P. caribbica and its biocontrol efficacy on apples. PMID:25029482

  9. Ascorbic acid enhances oxidative stress tolerance and biological control efficacy of Pichia caribbica against postharvest blue mold decay of apples.

    PubMed

    Li, Chaolan; Zhang, Hongyin; Yang, Qiya; Komla, Mahunu Gustav; Zhang, Xiaoyun; Zhu, Shuyun

    2014-07-30

    The effect of ascorbic acid (VC) on improving oxidative stress tolerance of Pichia caribbica and biocontrol efficacy against blue mold caused by Penicillium expansum on apples was investigated. P. caribbica showed susceptibility to the oxidative stress in vitro test, and 250 μg/mL VC treatment improved its oxidative stress tolerance. The higher viability exhibited by VC-treated yeast was associated with a lower intracellular ROS level. The activities of antioxidant enzymes of P. caribbica were improved by VC treatment, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX). Additionally, VC-treated yeast exhibited greater biocontrol activity against P. expansum and faster growth when stored at 25 and 4 °C, respectively, compared to the performance of the non-VC-treated yeast. In response to the VC treatment under oxidative stress, several differentially expressed proteins were identified in P. caribbica, and most of the poteins were confirmed to be related to basic metabolism. Therefore, the application of ascorbic acid is a useful approach to improve oxidative stress tolerance of P. caribbica and its biocontrol efficacy on apples.

  10. Verapamil reverses PTH- or CRF-induced abnormal fatty acid oxidation in muscle

    SciTech Connect

    Perna, A.F.; Smogorzewski, M.; Massry, S.G.

    1988-12-01

    Chronic renal failure (CRF) is associated with impaired long chain fatty acids (LCFA) oxidation by skeletal muscle mitochondria. This is due to reduced activity of carnitine palmitoyl transferase (CPT). These derangements were attributed to the secondary hyperparathyroidism of CRF, since prior parathyroidectomy in CRF rats reversed these abnormalities and PTH administration to normal rats reproduced them. It was proposed that these effects of PTH are mediated by its ionophoric property leading to increased entry of calcium into skeletal muscle. A calcium channel blocker may, therefore, correct these derangements. The present study examined the effects of verapamil on LCFA oxidation, CPT activity by skeletal muscle mitochondria, and /sup 45/Ca uptake by skeletal muscle obtained from CRF rats and normal animals treated with PTH with and without verapamil. Both four days of PTH administration and 21 days of CRF produced significant (P less than 0.01) reduction in LCFA oxidation and CPT activity of skeletal muscle mitochondria, and significant (P less than 0.01) increment in /sup 45/Ca uptake by skeletal muscle. Simultaneous treatment with verapamil corrected all these derangements. Administration of verapamil alone to normal rats did not cause a significant change in any of these parameters. The data are consistent with the proposition that the alterations in LCFA in CRF or after PTH treatment are related to the ionophoric action of the hormone and could be reversed by a calcium channel blocker.

  11. Protective effect of alpha-lipoic acid on cypermethrin-induced oxidative stress in Wistar rats.

    PubMed

    Mignini, F; Nasuti, C; Fedeli, D; Mattioli, L; Cosenza, M; Artico, M; Gabbianelli, R

    2013-01-01

    Cypermethrin (CY), a class II pyrethroid pesticide, is globally used to control insects in the household and in agriculture. Despite beneficial roles, its uncontrolled and repetitive application leads to unintended effects in non-target organisms. In light of the relevant anti-oxidant properties of alpha-lipoic acid (ALA), in the work described herein we tested the effect of a commercially available ALA formulation on cypermethrin CY)-induced oxidative stress in Wistar rats. The rats were orally administered with 53.14 mg/kg of ALA and 35.71 mg/kg of CY for 60 days. The treatment with CY did not induce changes in either locomotor activities or in body weight. Differences were observed on superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation that were re-established by ALA treatment at similar levels of the placebo group. Furthermore, ALA formulation increased glutathione (GSH) level and glutathione peroxidase (GPx) activity. Because of the widespread use of CY, higher amounts of pesticide residues are present in food, and a diet supplementation with ALA could be an active free radical scavenger protecting against diseases associated with oxidative stress.

  12. 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.

  13. Impact of ultrasound application on oxidative desulphurization of diesel fuel and on treatment of resulting wastewater.

    PubMed

    Margeta, Dunja; Grčić, Ivana; Papić, Sanja; Sertić-Bionda, Katica; Foglar, Lucija

    2016-01-01

    The ultrasound-assisted oxidative desulphurization (UAOD) process of diesel fuel has gained growing attention due to the strict regulation of sulphur content in the fuel. The goal of the present study was to investigate the impact of ultrasound (US) application for oxidative desulphurization (ODS) of hydrocarbon fuels and for the subsequent treatment of produced wastewater, since sonochemical processes are a new and interesting area of research with wide application in the field of environmental engineering. For that purpose, the model diesel fuel with initial sulphur concentration of 1220-3976 mg l(-1) was used for ODS and UAOD tests, and hydrogen peroxide/acetic acid was applied as the oxidant/catalyst system, respectively. The comparison of the process performance revealed that US significantly reduced the oxidation reaction time. The conversions of dibenzothiophene during 30 min of ODS and UAOD tests were 36% and 87%, respectively. Moreover, subsequent extraction with acetonitrile resulted in the final sulphur removal of 96.5%. The obtained results clearly indicated that UAOD process is beneficial for effective sulphur removal from the model diesel fuel. Furthermore, subsequent experiments included the application of the sono-Fenton process for resulting wastewater treatment. Monitoring of dibenzothiophene sulphone concentration and total organic carbon during the sono-Fenton treatment of wastewater revealed the decrease of 70-75% and 53-66%, respectively. The hypothesis on the possibility of degradation of dibenzothiophene sulphone by •OH radicals was confirmed by observed generation of benzoic acid and aliphatic carboxylic acids during experiments. Accordingly, the wastewater was purified to a satisfactory degree, enabling the reuse of treated water.

  14. Impact of ultrasound application on oxidative desulphurization of diesel fuel and on treatment of resulting wastewater.

    PubMed

    Margeta, Dunja; Grčić, Ivana; Papić, Sanja; Sertić-Bionda, Katica; Foglar, Lucija

    2016-01-01

    The ultrasound-assisted oxidative desulphurization (UAOD) process of diesel fuel has gained growing attention due to the strict regulation of sulphur content in the fuel. The goal of the present study was to investigate the impact of ultrasound (US) application for oxidative desulphurization (ODS) of hydrocarbon fuels and for the subsequent treatment of produced wastewater, since sonochemical processes are a new and interesting area of research with wide application in the field of environmental engineering. For that purpose, the model diesel fuel with initial sulphur concentration of 1220-3976 mg l(-1) was used for ODS and UAOD tests, and hydrogen peroxide/acetic acid was applied as the oxidant/catalyst system, respectively. The comparison of the process performance revealed that US significantly reduced the oxidation reaction time. The conversions of dibenzothiophene during 30 min of ODS and UAOD tests were 36% and 87%, respectively. Moreover, subsequent extraction with acetonitrile resulted in the final sulphur removal of 96.5%. The obtained results clearly indicated that UAOD process is beneficial for effective sulphur removal from the model diesel fuel. Furthermore, subsequent experiments included the application of the sono-Fenton process for resulting wastewater treatment. Monitoring of dibenzothiophene sulphone concentration and total organic carbon during the sono-Fenton treatment of wastewater revealed the decrease of 70-75% and 53-66%, respectively. The hypothesis on the possibility of degradation of dibenzothiophene sulphone by •OH radicals was confirmed by observed generation of benzoic acid and aliphatic carboxylic acids during experiments. Accordingly, the wastewater was purified to a satisfactory degree, enabling the reuse of treated water. PMID:26166709

  15. Alpha-oxidation of fatty acids in fasted or diabetic rats.

    PubMed

    Takahashi, T; Takahashi, H; Takeda, H; Shichiri, M

    1992-05-01

    Induction of alpha-oxidation, a possible gluconeogenic process, which should produce odd-chain fatty acids from even-chain fatty acids, was studied in rats fasted or made diabetic with streptozotocin. When a omega-phenylated even-chain fatty acid, phenylbutyric acid (1.2 mmol/kg), was administered to rats under these conditions, a significant increase in the urinary excretion of benzoic acid, the metabolic end-product of omega-phenylated odd-chain fatty acids, was observed in fasted (3.54 +/- 0.46 mumol/day) and diabetic (6.73 +/- 2.10) rats (control, 0.58 +/- 0.43; P less than 0.001). Phenylated longer chain fatty acids, phenylhexanoic and phenyldecanoic acid, did not produce significantly more benzoic acid than did phenylbutyric acid. Although the rate of alpha-oxidation was very low compared to that of beta-oxidation, these results suggested that alpha-oxidation of fatty acids was induced under fasting or diabetic conditions, and that alpha-oxidation might take place at the butyric acid stage. PMID:1600847

  16. Stimulation of polyunsaturated fatty acid oxidation in myocytes by regulating its cellular uptake

    SciTech Connect

    Abdel-aleem, S.; Frangakis, C. ); Badr, M. )

    1991-01-01

    In order to investigate the regulation of polyunsaturated fatty acid oxidation in the heart, the effect of the phosphodiesterase inhibitor enoximone on the oxidation of (1-{sup 14}C) arachidonic acid, and (1-{sup 14}C) arachidonyl-CoA, were studied in adult rat myocytes, and isolated rat heart mitochondria. Enoximone stimulated arachidonate oxidation by 94%, at a concentration of 0.25 mM. The apparent Vmax value of archidonate oxidation in the presence of enoximone was approximately 75% higher than the value observed with the control in isolated myocytes. Also, enoximone stimulated arachidonate uptake by 27% at a concentration of 0.25 mM. On the other hand, enoximone had no effect on the oxidation of (1-{sup 14}C) arachidonyl-CoA in isolated rat heart mitochondria. These results suggest that the oxidation of polyunsaturated fatty acids in myocytes is regulated by the rate of uptake of these acids across sarcolemmal membranes.

  17. Evaluating and predicting the oxidative stability of vegetable oils with different fatty acid compositions.

    PubMed

    Li, Hongyan; Fan, Ya-wei; Li, Jing; Tang, Liang; Hu, Jiang-ning; Deng, Ze-yuan

    2013-04-01

    The aim of this research was to evaluate the oxidative stabilities and qualities of different vegetable oils (almond, blend 1-8, camellia, corn, palm, peanut, rapeseed, sesame, soybean, sunflower, and zanthoxylum oil) based on peroxide value (PV), vitamin E content, free fatty acid, and fatty acid composition. The vegetable oils with different initial fatty acid compositions were studied under accelerated oxidation condition. It showed that PV and n-3 polyunsaturated fatty acid (PUFA) changed significantly during 21 d accelerated oxidation storage. Based on the changes of PV and fatty acid composition during the oxidation process, mathematical models were hypothesized and the models were simulated by Matlab to generate the proposed equations. These equations were established on the basis of the different PUFA contents as 10% to 28%, 28% to 46%, and 46% to 64%, respectively. The simulated models were proven to be validated and valuable for assessing the degree of oxidation and predicting the shelf life of vegetable oils.

  18. KetoABNO/NOx Cocatalytic Aerobic Oxidation of Aldehydes to Carboxylic Acids and Access to α-Chiral Carboxylic Acids via Sequential Asymmetric Hydroformylation/Oxidation.

    PubMed

    Miles, Kelsey C; Abrams, M Leigh; Landis, Clark R; Stahl, Shannon S

    2016-08-01

    A method for aerobic oxidation of aldehydes to carboxylic acids has been developed using organic nitroxyl and NOx cocatalysts. KetoABNO (9-azabicyclo[3.3.1]nonan-3-one N-oxyl) and NaNO2 were identified as the optimal nitroxyl and NOx sources, respectively. The mildness of the reaction conditions enables sequential asymmetric hydroformylation of alkenes/aerobic aldehyde oxidation to access α-chiral carboxylic acids without racemization. The scope, utility, and limitations of the oxidation method are further evaluated with a series of achiral aldehydes bearing diverse functional groups.

  19. Enzymology of the branched-chain amino acid oxidation disorders: the valine pathway.

    PubMed

    Wanders, Ronald J A; Duran, Marinus; Loupatty, Ference J

    2012-01-01

    Valine is one of the three branched-chain amino acids which undergoes oxidation within mitochondria. In this paper, we describe the current state of knowledge with respect to the enzymology of the valine oxidation pathway and the different disorders affecting oxidation.

  20. 21 CFR 178.3770 - Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyhydric alcohol esters of oxidatively refined... SANITIZERS Certain Adjuvants and Production Aids § 178.3770 Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids. Polyhydric alcohol esters of oxidatively refined (Gersthofen...

  1. 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

  2. A "Green" route to adipic acid: direct oxidation of cyclohexenes with 30 percent hydrogen peroxide

    PubMed

    Sato; Aoki; Noyori

    1998-09-11

    Currently, the industrial production of adipic acid uses nitric acid oxidation of cyclohexanol or a cyclohexanol/cyclohexanone mixture. The nitrous oxide emission from this process measurably contributes to global warming and ozone depletion. Therefore, the development of an adipic acid production process that is less damaging to the environment is an important subject in chemical research. Cyclohexene can now be oxidized directly to colorless crystalline adipic acid with aqueous 30 percent hydrogen peroxide under organic solvent- and halide-free conditions, which could provide an ideal solution to this serious problem.

  3. Hydrothermal acid treatment for sugar extraction from Golenkinia sp.

    PubMed

    Choi, Sun-A; Choi, Won-Il; Lee, Jin-Suk; Kim, Seung Wook; Lee, Gye-An; Yun, Jihyun; Park, Ji-Yeon

    2015-08-01

    In this study, hydrothermal acid treatment for efficient recovery of sugar from Golenkinia sp. was investigated. The initial glucose and XMG (xylose, mannose, and galactose) contents of a prepared Golenkinia sp. solution (40g/L) were 15.05 and 5.24g/L, respectively. The microalgal cell walls were hydrolyzed, for sugar recovery, by enzymatic saccharification and/or hydrothermal acid treatment. Among the various hydrothermal acid treatment conditions, the most optimal were the 2.0% H2SO4 concentration at 150°C for 15min, under which the glucose- and XMG-extraction yields were 71.7% and 64.9%, respectively. By pH 4.8, 50°C enzymatic hydrolysis after optimal hydrothermal acid treatment, the glucose- and XMG-extraction yields were additionally increased by 8.3% and 0.8%, respectively. After hydrothermal acid treatment, the combination with the enzymatic hydrolysis process improved the total sugar yield of Golenkinia sp. to 75.4%.

  4. 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.

  5. Mitochondrial fatty acid oxidation alterations in heart failure, ischaemic heart disease and diabetic cardiomyopathy

    PubMed Central

    Fillmore, N; Mori, J; Lopaschuk, G D

    2014-01-01

    Heart disease is a leading cause of death worldwide. In many forms of heart disease, including heart failure, ischaemic heart disease and diabetic cardiomyopathies, changes in cardiac mitochondrial energy metabolism contribute to contractile dysfunction and to a decrease in cardiac efficiency. Specific metabolic changes include a relative increase in cardiac fatty acid oxidation rates and an uncoupling of glycolysis from glucose oxidation. In heart failure, overall mitochondrial oxidative metabolism can be impaired while, in ischaemic heart disease, energy production is impaired due to a limitation of oxygen supply. In both of these conditions, residual mitochondrial fatty acid oxidation dominates over mitochondrial glucose oxidation. In diabetes, the ratio of cardiac fatty acid oxidation to glucose oxidation also increases, although primarily due to an increase in fatty acid oxidation and an inhibition of glucose oxidation. Recent evidence suggests that therapeutically regulating cardiac energy metabolism by reducing fatty acid oxidation and/or increasing glucose oxidation can improve cardiac function of the ischaemic heart, the failing heart and in diabetic cardiomyopathies. In this article, we review the cardiac mitochondrial energy metabolic changes that occur in these forms of heart disease, what role alterations in mitochondrial fatty acid oxidation have in contributing to cardiac dysfunction and the potential for targeting fatty acid oxidation to treat these forms of heart disease. LINKED ARTICLES This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue-8 PMID:24147975

  6. Fatigue and Oxidative Stress in Children Undergoing Leukemia Treatment.

    PubMed

    Rodgers, Cheryl; Sanborn, Chelse; Taylor, Olga; Gundy, Patricia; Pasvogel, Alice; Moore, Ida M Ki; Hockenberry, Marilyn J

    2016-10-01

    Fatigue is a frequent and distressing symptom in children undergoing leukemia treatment; however, little is known about factors influencing this symptom. Antioxidants such as glutathione can decrease symptom severity in adult oncology patients, but no study has evaluated antioxidants' effects on symptoms in pediatric oncology patients. This study describes fatigue patterns and associations of fatigue with antioxidants represented by reduced glutathione (GSH) and the reduced/oxidized glutathione (GSH/GSSG) ratio among children receiving leukemia treatment. A repeated measures design assessed fatigue and antioxidants among 38 children from two large U.S. cancer centers. Fatigue was assessed among school-age children and by parent proxy among young children. Antioxidants (GSH and GSH/GSSG ratio) were assessed from cerebrospinal fluid at four phases during leukemia treatment. Young children had a steady decline of fatigue from the end of induction treatment through the continuation phase of treatment, but no significant changes were noted among the school-age children. Mean antioxidant scores varied slightly over time; however, the GSH/GSSG ratios in these children were significantly lower than the normal ratio. Mean GSH/GSSG ratios significantly correlated to fatigue scores of the school-age children during early phases of treatment. Children with low mean GSH/GSSG ratios demonstrated oxidative stress. The low ratios noted early in therapy were significantly correlated with higher fatigue scores during induction and postinduction treatment phases. This finding suggests that increased oxidative stress during the more intensive phases of therapy may explain the experience of fatigue children report.

  7. Simple quantification of surface carboxylic acids on chemically oxidized multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Gong, Hyejin; Kim, Seong-Taek; Lee, Jong Doo; Yim, Sanggyu

    2013-02-01

    The surface of multi-walled carbon nanotube (MWCNT) was chemically oxidized using nitric acid and sulfuric-nitric acid mixtures. Thermogravimetric analysis, transmission electron microscopy and infrared spectroscopy revealed that the use of acid mixtures led to higher degree of oxidation. More quantitative identification of surface carboxylic acids was carried out using X-ray photoelectron spectroscopy (XPS) and acid-base titration. However, these techniques are costly and require very long analysis times to promptly respond to the extent of the reaction. We propose a much simpler method using pH measurements and pre-determined pKa value in order to estimate the concentration of carboxylic acids on the oxidized MWCNT surfaces. The results from this technique were consistent with those obtained from XPS and titration, and it is expected that this simple quantification method can provide a cheap and fast way to monitor and control the oxidation reaction of MWCNT.

  8. Ascorbic acid: Chemistry, biology and the treatment of cancer☆

    PubMed Central

    Du, Juan; Cullen, Joseph J.; Buettner, Garry R.

    2013-01-01

    Since the discovery of vitamin C, the number of its known biological functions is continually expanding. Both the names ascorbic acid and vitamin C reflect its antiscorbutic properties due to its role in the synthesis of collagen in connective tissues. Ascorbate acts as an electron-donor keeping iron in the ferrous state thereby maintaining the full activity of collagen hydroxylases; parallel reactions with a variety of dioxygenases affect the expression of a wide array of genes, for example via the HIF system, as well as via the epigenetic landscape of cells and tissues. In fact, all known physiological and biochemical functions of ascorbate are due to its action as an electron donor. The ability to donate one or two electrons makes AscH− an excellent reducing agent and antioxidant. Ascorbate readily undergoes pH-dependent autoxidation producing hydrogen peroxide (H2O2). In the presence of catalytic metals this oxidation is accelerated. In this review, we show that the chemical and biochemical nature of ascorbate contribute to its antioxidant as well as its prooxidant properties. Recent pharmacokinetic data indicate that intravenous (i.v.) administration of ascorbate bypasses the tight control of the gut producing highly elevated plasma levels; ascorbate at very high levels can act as prodrug to deliver a significant flux of H2O2 to tumors. This new knowledge has rekindled interest and spurred new research into the clinical potential of pharmacological ascorbate. Knowledge and understanding of the mechanisms of action of pharmacological ascorbate bring a rationale to its use to treat disease especially the use of i.v. delivery of pharmacological ascorbate as an adjuvant in the treatment of cancer. PMID:22728050

  9. Plasma-chemical waste treatment of acid gases

    SciTech Connect

    Harkness, J.B.L.; Doctor, R.D.; Daniels, E.J.

    1993-09-01

    The research to date has shown that a H{sub 2}S waste-treatment process based on plasma-chemical dissociation technology is compatible with refinery and high-carbon-oxide acid-gas streams. The minor amounts of impurities produced in the plasma-chemical reactor should be treatable by an internal catalytic reduction step. Furthermore, the plasma-chemical technology appears to be more efficient and more economical than the current technology. The principal key to achieving high conversions with relatively low energies of dissociation is the concept of the high-velocity, cyclonic-flow pattern in the plasma reaction zone coupled with the recycling of unconverted hydrogen sulfide. Future work will include testing the effects of components that might be carried over to the plasma reactor by ``upset`` conditions in the amine purification system of a plant and testing the plasma-chemical process on other industrial wastes streams that contain potentially valuable chemical reagents. The strategy for the commercialization of this technology is to form a Cooperative Research and Development Agreement with the Institute of Hydrogen Energy and Plasma Technology of the Russian Scientific Center/Kurchatov Institute and with an American start-up company to develop an ``American`` version of the process and to build a commercial-scale demonstration unit in the United States. The timetable proposed would involve building a ``field test`` facility which would test the plasma-chemical reactor and sulfur recovery unit operations on an industrial hydrogen sulfide waste s at a scale large enough to obtain the energy and material balance data required for a final analysis of the commercial potential of this technology. The field test would then be followed by construction of a commercial demonstration unit in two to three years. The commercial demonstration unit would be a fully integrated plant consisting of one commercial-scale module.

  10. Impact of citric acid on the tenderness, microstructure and oxidative stability of beef muscle.

    PubMed

    Ke, Shuming; Huang, Yan; Decker, Eric A; Hultin, Herbert O

    2009-05-01

    Acidification of meat can improve texture however it also increases susceptibility to lipid oxidation. The effect of injection and marination of citric acid to acidify and sodium carbonate or sodium tri-polyphosphate to increase pH of beef on tenderness, microstructure and oxidative stability was determined. Water-holding capacity and tenderness of beef semitendinosus muscle increased significantly at pH 3.52 upon addition of citric acid and returned to the level of untreated sample after pH was increased (pH ∼5.26) by sodium tri-polyphosphate. The microstructure of the muscle was lost upon acidification but reformed upon increasing muscle pH. Lipid oxidation was inhibited in cooked beef blocks and ground muscle acidified with citric acid. Lipid oxidation was also inhibited in citric acid acidified beef that was readjustment to pH values equal to or greater than the raw beef muscle with sodium tri-polyphosphate or sodium carbonate. In addition, citric acid that was adjusted to the pH of the raw beef so that it did not alter the pH of the beef also inhibited lipid oxidation. These results indicate that citric acid and not sodium tri-polyphosphate or pH adjustment was responsible for inhibiting lipid oxidation in beef. These results suggest that the best acid marination technique for beef would be citric acid since it is effective at both improving texture and inhibiting lipid oxidation.

  11. Arsenite treatment induces oxidative stress, upregulates antioxidant system, and causes phytochelatin synthesis in rice seedlings.

    PubMed

    Mishra, Shruti; Jha, A B; Dubey, R S

    2011-07-01

    The effects of arsenite treatment on generation of reactive oxygen species, induction of oxidative stress, response of antioxidative system, and synthesis of phytochelatins were investigated in two indica rice (Oryza sativa L.) cvs. Malviya-36 and Pant-12 grown in sand cultures for a period of 5-20 days. Arsenite (As(2)O(3); 25 and 50 μM) treatment resulted in increased formation of superoxide anion (O (2) (.-) ), elevated levels of H(2)O(2) and thiobarbituric acid reactive substances, showing enhanced lipid peroxidation. An enhanced level of ascorbate (AA) and glutathione (GSH) was observed irrespective of the variation in the level of dehydroascorbate (DHA) and oxidized glutathione (GSSG) which in turn influenced redox ratios AA/DHA and GSH/GSSG. With progressive arsenite treatment, synthesis of total acid soluble thiols and phytochelatins (PC) increased in the seedlings. Among antioxidative enzymes, the activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), total ascorbate peroxidase (APX, EC 1.11.1.11), chloroplastic ascorbate peroxidase, guaiacol peroxidase (EC 1.11.1.7), monodehydroascorbate reductase (EC 1.6.5.4), and glutathione reductase (EC 1.6.4.2) increased in arsenite treated seedlings, while dehyroascorbate reductase (EC 1.8.5.1) activity declined initially during 5-10 days and increased thereafter. Results suggest that arsenite treatment causes oxidative stress in rice seedlings, increases the levels of many enzymatic and non-enzymatic antioxidants, and induces synthesis of thiols and PCs, which may serve as important components in mitigating arsenite-induced oxidative damage.

  12. Oxidation kinetics of antibiotics during water treatment with potassium permanganate.

    PubMed

    Hu, Lanhua; Martin, Heather M; Strathmann, Timothy J

    2010-08-15

    The ubiquitous occurrence of antibiotics in aquatic environments raises concerns about potential adverse effects on aquatic ecology and human health, including the promotion of increased antibiotic resistance. This study examined the oxidation of three widely detected antibiotics (ciprofloxacin, lincomycin, and trimethoprim) by potassium permanganate [KMnO(4); Mn(VII)]. Reaction kinetics were described by second-order rate laws, with apparent second-order rate constants (k(2)) at pH 7 and 25 degrees C in the order of 0.61 +/- 0.02 M(-1) s(-1) (ciprofloxacin) < 1.6 +/- 0.1 M(-1) s(-1) (trimethoprim) < 3.6 +/- 0.1 M(-1) s(-1) (lincomycin). Arrhenius temperature dependence was observed with apparent activation energies (E(a)) ranging from 49 kJ mol(-1) (trimethoprim) to 68 kJ mol(-1) (lincomycin). Rates of lincomycin and trimethoprim oxidation exhibited marked pH dependences, whereas pH had only a small effect on rates of ciprofloxacin oxidation. The effects of pH were quantitatively described by considering parallel reactions between KMnO(4) and individual acid-base species of the target antibiotics. Predictions from a kinetic model that included temperature, KMnO(4) dosage, pH, and source water oxidant demand as input parameters agreed reasonably well with measurements of trimethoprim and lincomycin oxidation in six drinking water utility sources. Although Mn(VII) reactivity with the antibiotics was lower than that reported for ozone and free chlorine, its high selectivity and stability suggests a promising oxidant for treating sensitive micropollutants in organic-rich matrices (e.g., wastewater).

  13. Localization of nervonic acid beta-oxidation in human and rodent peroxisomes: impaired oxidation in Zellweger syndrome and X-linked adrenoleukodystrophy.

    PubMed

    Sandhir, R; Khan, M; Chahal, A; Singh, I

    1998-11-01

    Studies with purified subcellular organelles from rat liver indicate that nervonic acid (C24:1) is beta-oxidized preferentially in peroxisomes. Lack of effect by etomoxir, inhibitor of mitochondrial beta-oxidation, on beta-oxidation of lignoceric acid (C24:0), a peroxisomal function, and that of nervonic acid (24:1) compared to the inhibition of palmitic acid (16:0) oxidation, a mitochondrial function, supports the conclusion that nervonic acid is oxidized in peroxisomes. Moreover, the oxidation of nervonic and lignoceric acids was deficient in fibroblasts from patients with defects in peroxisomal beta-oxidation [Zellweger syndrome (ZS) and X-linked adrenoleukodystrophy (X-ALD)]. Similar to lignoceric acid, the activation and beta-oxidation of nervonic acid was deficient in peroxisomes isolated from X-ALD fibroblasts. Transfection of X-ALD fibroblasts with human cDNA encoding for ALDP (X-ALD gene product) restored the oxidation of both nervonic and lignoceric acids, demonstrating that the same molecular defect may be responsible for the abnormality in the oxidation of nervonic as well as lignoceric acid. Moreover, immunoprecipitation of activities for acyl-CoA ligase for both lignoceric acid and nervonic acid indicate that saturated and monoenoic very long chain (VLC) fatty acids may be activated by the same enzyme. These results clearly demonstrate that similar to saturated VLC fatty acids (e.g., lignoceric acid), VLC monounsaturated fatty acids (e.g., nervonic acid) are oxidized preferentially in peroxisomes and that this activity is impaired in X-ALD. In view of the fact that the oxidation of unsaturated VLC fatty acids is defective in X-ALD patients, the efficacy of dietary monoene therapy, "Lorenzo's oil," in X-ALD needs to be evaluated.

  14. Amoxycillin and clavulanic acid in the treatment of urinary infection.

    PubMed Central

    Al Roomi, L G; Sutton, A M; Cockburn, F; McAllister, T A

    1984-01-01

    The pharmacokinetics and clinical efficacy of amoxycillin combined with clavulanic acid in the treatment of 32 children with urinary tract infection were studied. Twenty one (80%) of 26 children with proved urinary tract infection showed a favourable clinical and bacteriological response. Fifteen of these children had amoxycillin resistant organisms and were treated successfully. In 20 children the serum and urine concentrations of amoxycillin and clavulanic acid were measured after the first oral dose. PMID:6712275

  15. Effect of omega-3 fatty acid on oxidative stress in patients on hemodialysis.

    PubMed

    Tayyebi-Khosroshahi, Hamid; Houshyar, Jalil; Tabrizi, Ali; Vatankhah, Amir-Mansour; Razzagi Zonouz, Neda; Dehghan-Hesari, Reza

    2010-10-01

    INTRODUCTION. Oxidative stress in patients with chronic kidney failure, particularly in hemodialysis patients, has been suggested to have a major role in the pathogenesis of atherosclerosis. We evaluated omega-3 fatty acids supplementation effects on oxidative and antioxidant factors in hemodialysis patients. MATERIALS AND METHODS. In a clinical trial, patients on hemodialysis were divided into 2 groups in order to receive either omega-3 fatty aid capsule, 1 g 3 times a day, or placebo for 2 months. The two groups were comparable in terms of sex distribution, age, medications, diabetes mellitus, hemoglobin level, serum ferritin, and serum albumin. Blood samples taken from patients before and at the end of the study period were examined for oxidative stress markers including malondialdehyde, glutathione peroxidase, superoxide dismutase, and ferric reducing antioxidant power. RESULTS. Seventy-five hemodialysis patients were divided into the omega-3 group (n = 37) and the control group (n = 38). Before the treatment period, the two groups were comparable in the malondialdehyde, glutathione peroxidase, superoxide dismutase, and ferric reducing antioxidant power levels. In the patients who received omega-3 fatty acids, antioxidant factors including glutathione peroxidase, superoxide dismutase, and ferric reducing antioxidant power were significantly increased after two months (P = .02, P = .02, and P = .01, respectively); however, there was no significant changes in the control group in these markers. Malondialdehyde levels were significantly reduced after the study period only in the omega-3 group (P = .007). CONCLUSIONS. The present study revealed that the supplementation with omega-3 fatty acids may result in better antioxidation status in patients on maintenance hemodialysis.

  16. Hexanoic acid protects tomato plants against Botrytis cinerea by priming defence responses and reducing oxidative stress.

    PubMed

    Finiti, Ivan; de la O Leyva, María; Vicedo, Begonya; Gómez-Pastor, Rocío; López-Cruz, Jaime; García-Agustín, Pilar; Real, Maria Dolores; González-Bosch, Carmen

    2014-08-01

    Treatment with the resistance priming inducer hexanoic acid (Hx) protects tomato plants from Botrytis cinerea by activating defence responses. To investigate the molecular mechanisms underlying hexanoic acid-induced resistance (Hx-IR), we compared the expression profiles of three different conditions: Botrytis-infected plants (Inf), Hx-treated plants (Hx) and Hx-treated + infected plants (Hx+Inf). The microarray analysis at 24 h post-inoculation showed that Hx and Hx+Inf plants exhibited the differential expression and priming of many Botrytis-induced genes. Interestingly, we found that the activation by Hx of other genes was not altered by the fungus at this time point. These genes may be considered to be specific targets of the Hx priming effect and may help to elucidate its mechanisms of action. It is noteworthy that, in Hx and Hx+Inf plants, there was up-regulation of proteinase inhibitor genes, DNA-binding factors, enzymes involved in plant hormone signalling and synthesis, and, remarkably, the genes involved in oxidative stress. Given the relevance of the oxidative burst occurring in plant-pathogen interactions, the effect of Hx on this process was studied in depth. We showed by specific staining that reactive oxygen species (ROS) accumulation in Hx+Inf plants was reduced and more restricted around infection sites. In addition, these plants showed higher ratios of reduced to oxidized glutathione and ascorbate, and normal levels of antioxidant activities. The results obtained indicate that Hx protects tomato plants from B. cinerea by regulating and priming Botrytis-specific and non-specific genes, preventing the harmful effects of oxidative stress produced by infection.

  17. Combination of omega-3 Fatty acids, lithium, and aripiprazole reduces oxidative stress in brain of mice with mania.

    PubMed

    Arunagiri, Pandiyan; Rajeshwaran, Krishnamoorthy; Shanthakumar, Janakiraman; Tamilselvan, Thangavel; Balamurugan, Elumalai

    2014-09-01

    Manic episode in bipolar disorder (BD) was evaluated in the present study with supplementation of omega-3 fatty acids in combination with aripiprazole and lithium on methylphenidate (MPD)-induced manic mice model. Administration of MPD 5 mg/kg bw intraperitoneally (i.p.) caused increase in oxidative stress in mice brain. To retract this effect, supplementation of omega-3 fatty acids 1.5 ml/kg (p.o.), aripiprazole 1.5 mg/kg bw (i.p.), and lithium 50 mg/kg bw (p.o) were given to mice. Omega-3 fatty acids alone and in combination with aripiprazole- and lithium-treated groups significantly reduced the levels of superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation products (thiobarbituric acid reactive substances) in the brain. MPD treatment significantly decreased the reduced glutathione (GSH) level and glutathione peroxidase (GPx) activity, and they were restored by supplementation of omega-3 fatty acids with aripiprazole and lithium. There is no remarkable difference in the effect of creatine kinase (CK) activity between MPD-induced manic model and the treatment groups. Therefore, our results demonstrate that oxidative stress imbalance and mild insignificant CK alterations induced by administration of MPD can be restored back to normal physiological levels through omega-3 fatty acids combined with lithium and aripiprazole that attributes to effective prevention against mania in adult male Swiss albino mice.

  18. Hepatic oleate regulates adipose tissue lipogenesis and fatty acid oxidation.

    PubMed

    Burhans, Maggie S; Flowers, Matthew T; Harrington, Kristin R; Bond, Laura M; Guo, Chang-An; Anderson, Rozalyn M; Ntambi, James M

    2015-02-01

    Hepatic steatosis is associated with detrimental metabolic phenotypes including enhanced risk for diabetes. Stearoyl-CoA desaturases (SCDs) catalyze the synthesis of MUFAs. In mice, genetic ablation of SCDs reduces hepatic de novo lipogenesis (DNL) and protects against diet-induced hepatic steatosis and adiposity. To understand the mechanism by which hepatic MUFA production influences adipose tissue stores, we created two liver-specific transgenic mouse models in the SCD1 knockout that express either human SCD5 or mouse SCD3, that synthesize oleate and palmitoleate, respectively. We demonstrate that hepatic de novo synthesized oleate, but not palmitoleate, stimulate hepatic lipid accumulation and adiposity, reversing the protective effect of the global SCD1 knockout under lipogenic conditions. Unexpectedly, the accumulation of hepatic lipid occurred without induction of the hepatic DNL program. Changes in hepatic lipid composition were reflected in plasma and in adipose tissue. Importantly, endogenously synthesized hepatic oleate was associated with suppressed DNL and fatty acid oxidation in white adipose tissue. Regression analysis revealed a strong correlation between adipose tissue lipid fuel utilization and hepatic and adipose tissue lipid storage. These data suggest an extrahepatic mechanism where endogenous hepatic oleate regulates lipid homeostasis in adipose tissues.

  19. Evaluation of advanced oxidation process for the treatment of groundwater

    SciTech Connect

    Garland, S.B. II ); Peyton, G.R. ); Rice, L.E. . Kansas City Div.)

    1990-01-01

    An advanced oxidation process utilizing ozone, ultraviolet radiation, and hydrogen peroxide was selected for the removal of chlorinated hydrocarbons, particularly trichlorethene and 1,2-dichlorethene, from groundwater underlying the US Department of Energy Kansas City Plant. Since the performance of this process for the removal of organics from groundwater is not well-documented, an evaluation was initiated to determine the performance of the treatment plant, document the operation and maintenance costs experience, and evaluate contaminant removal mechanisms. 11 refs., 3 figs.

  20. Quercetin Treatment Ameliorates Systemic Oxidative Stress in Cirrhotic Rats

    PubMed Central

    Vieira, Emanuelle Kerber; Bona, Silvia; Di Naso, Fábio Cangeri; Porawski, Marilene; Tieppo, Juliana; Marroni, Norma Possa

    2011-01-01

    Our aim was to investigate whether the antioxidant quercetin protects against liver injury and ameliorates the systemic oxidative stress in rats with common bile duct ligation. Secondary biliary cirrhosis was induced through 28 days of bile duct obstruction. Animals received quercetin (Q) after 14 days of obstruction. Groups of control (CO) and cirrhotic (CBDL) animals received a daily 50 mg/kg body weight i.p. injection of quercetin (CO + Q; CBDL + Q) or vehicle (CO; CBDL). Quercetin corrected the reduction in superoxide dismutase (SOD), catalase CAT, and glutathione peroxidase GPx activities and prevented the increase of thiobarbituric acid reactive substances (TBARS), aminotransferases, and alkaline phosphatase in cirrhotic animals. Quercetin administration also corrected the reduced total nitrate concentration in the liver and prevented liver fibrosis and necrosis. These effects suggest that quercetin might be a useful agent to preserve liver function and prevent systemic oxidative stress. PMID:21991520

  1. Treatment of oxide spent fuel using the lithium reduction process

    SciTech Connect

    Karell, E.J.; Pierce, R.D.; Mulcahey, T.P.

    1996-05-01

    The wide variety in the composition of DOE spent nuclear fuel complicates its long-term disposition because of the potential requirement to individually qualify each type of fuel for repository disposal. Argonne National Laboratory (ANL) has developed the electrometallurgical treatment technique to convert all of these spent fuel types into a single set of disposal forms, simplifying the qualification process. While metallic fuels can be directly processed using the electrometallurgical treatment technique, oxide fuels must first be reduced to the metallic form. The lithium reduction process accomplishes this pretreatment. In the lithium process the oxide components of the fuel are reduced using lithium at 650 C in the presence of molten LiCl, yielding the corresponding metals and Li{sub 2}O. The reduced metal components are then separated from the LiCl salt phase and become the feed material for electrometallurgical treatment. A demonstration test of the lithium reduction process was successfully conducted using a 10-kg batch of simulated oxide spent fuel and engineering-scale equipment specifically constructed for that purpose. This paper describes the lithium process, the equipment used in the demonstration test, and the results of the demonstration test.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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.

  7. Theobromine Inhibits Uric Acid Crystallization. A Potential Application in the Treatment of Uric Acid Nephrolithiasis

    PubMed Central

    Grases, Felix; Rodriguez, Adrian; Costa-Bauza, Antonia

    2014-01-01

    Purpose To assess the capacity of methylxanthines (caffeine, theophylline, theobromine and paraxanthine) to inhibit uric acid crystallization, and to evaluate their potential application in the treatment of uric acid nephrolithiasis. Materials and Methods The ability of methylxathines to inhibit uric acid nucleation was assayed turbidimetrically. Crystal morphology and its modification due to the effect of theobromine were evaluated by scanning electron microscopy (SEM). The ability of theobromine to inhibit uric acid crystal growth on calculi fragments resulting from extracorporeal shock wave lithotripsy (ESWL) was evaluated using a flow system. Results The turbidimetric assay showed that among the studied methylxanthines, theobromine could markedly inhibit uric acid nucleation. SEM images showed that the presence of theobromine resulted in thinner uric acid crystals. Furthermore, in a flow system theobromine blocked the regrowth of post-ESWL uric acid calculi fragments. Conclusions Theobromine, a natural dimethylxanthine present in high amounts in cocoa, acts as an inhibitor of nucleation and crystal growth of uric acid. Therefore, theobromine may be clinically useful in the treatment of uric acid nephrolithiasis. PMID:25333633

  8. Oxidation of organic contaminants by manganese oxide geomedia for passive urban stormwater treatment systems.

    PubMed

    Grebel, Janel E; Charbonnet, Joseph A; Sedlak, David L

    2016-01-01

    To advance cost-effective strategies for removing trace organic contaminants from urban runoff, the feasibility of using manganese oxides as a geomedia amendment in engineered stormwater infiltration systems to oxidize organic contaminants was evaluated. Ten representative organic chemicals that have previously been detected in urban stormwater were evaluated for reactivity in batch experiments with birnessite. With respect to reactivity, contaminants could be classified as: highly reactive (e.g., bisphenol A), moderately reactive (e.g., diuron) and unreactive (e.g., tris(2-chloro-1-propyl)phosphate). Bisphenol A and diuron reacted with birnessite to produce a suite of products, including ring-cleavage products for bisphenol A and partially dechlorinated products for diuron. Columns packed with manganese oxide-coated sand were used evaluate design parameters for an engineered infiltration system, including necessary contact times for effective treatment, as well as the impacts of stormwater matrix variables, such as solution pH, concentration of natural organic matter and major anions and cations. The manganese oxide geomedia exhibited decreased reactivity when organic contaminants were oxidized, especially in the presence of divalent cations, bicarbonate, and natural organic matter. Under typical conditions, the manganese oxides are expected to retain their reactivity for 25 years.

  9. Effect of feeding fresh forage and marine algae on the fatty acid composition and oxidation of milk and butter.

    PubMed

    Glover, K E; Budge, S; Rose, M; Rupasinghe, H P V; Maclaren, L; Green-Johnson, J; Fredeen, A H

    2012-06-01

    This study evaluated the effects of feeding fresh forage either as pasture plus a concentrate (PAS) or as a silage-based total mixed ration (TMR), combined with either a ruminally inert lipid supplement high in saturated fatty acids (-) or a ruminally protected microalgae containing 22 g of docosahexaenoic acid (DHA)/100 g of fatty acids (+) on the fatty acid (FA) composition and oxidation of milk and butter. For the 8 mid-lactation Holstein cows in this study, milk yield was not significantly affected by treatment, averaging 32.3 ± 1.28 kg/d. Milk fat content was higher for PAS⁻, averaging 5.05 compared with 4.10 ± 0.17% for the mean of other treatments, and was significantly depressed with microalgae supplementation (3.97 vs. 4.69 ± 0.17%). The saturated fatty acid level in the milk of cows fed TMR⁻ was significantly higher than that of the other treatments (66.9 vs. 61.2 g/100 g of FA). The level of monounsaturated FA was lowered by feeding TMR⁻ (27.4 vs. 32.0 g/100 g of FA), whereas levels of polyunsaturated FA were elevated by feeding PAS+ compared with the mean of the other treatments (6.54 vs. 5.07 g/100 g of FA). Feeding the rumen-protected microalgae increased the DHA content of milk more than 4-fold (0.06 to 0.26 g/100g of FA) with the PAS treatment. The conjugated linoleic acid content of milk was highest for PAS+ compared with the other treatments (4.18 vs. 3.41 g/100g of FA). In general, the fatty acid composition of butter followed that of milk. Overall, feeding the TMR supplemented with the rumen-protected microalgae increased the levels of volatile products of oxidation in milk and butter. No effect of forage type or microalgae supplementation was observed on the oxidative stability or antioxidant capacity of milk, although the oxidative stability of butter exposed to UV was reduced with microalgae supplementation, particularly with TMR, as assessed by using the ferric reducing ability of plasma assay.

  10. Intratumoral iron oxide nanoparticle hyperthermia and radiation cancer treatment

    NASA Astrophysics Data System (ADS)

    Hoopes, P. J.; Strawbridge, R. R.; Gibson, U. J.; Zeng, Q.; Pierce, Z. E.; Savellano, M.; Tate, J. A.; Ogden, J. A.; Baker, I.; Ivkov, R.; Foreman, A. R.

    2007-02-01

    The potential synergism and benefit of combined hyperthermia and radiation for cancer treatment is well established, but has yet to be optimized clinically. Specifically, the delivery of heat via external arrays /applicators or interstitial antennas has not demonstrated the spatial precision or specificity necessary to achieve appropriate a highly positive therapeutic ratio. Recently, antibody directed and possibly even non-antibody directed iron oxide nanoparticle hyperthermia has shown significant promise as a tumor treatment modality. Our studies are designed to determine the effects (safety and efficacy) of iron oxide nanoparticle hyperthermia and external beam radiation in a murine breast cancer model. Methods: MTG-B murine breast cancer cells (1 x 106) were implanted subcutaneous in 7 week-old female C3H/HeJ mice and grown to a treatment size of 150 mm3 +/- 50 mm3. Tumors were then injected locally with iron oxide nanoparticles and heated via an alternating magnetic field (AMF) generator operated at approximately 160 kHz and 400 - 550 Oe. Tumor growth was monitored daily using standard 3-D caliper measurement technique and formula. specific Mouse tumors were heated using a cooled, 36 mm diameter square copper tube induction coil which provided optimal heating in a 1 cm wide region in the center of the coil. Double dextran coated 80 nm iron oxide nanoparticles (Triton Biosystems) were used in all studies. Intra-tumor, peri-tumor and rectal (core body) temperatures were continually measured throughout the treatment period. Results: Preliminary in vivo nanoparticle-AMF hyperthermia (167 KHz and 400 or 550 Oe) studies demonstrated dose responsive cytotoxicity which enhanced the effects of external beam radiation. AMF associated eddy currents resulted in nonspecific temperature increases in exposed tissues which did not contain nanoparticles, however these effects were minor and not injurious to the mice. These studies also suggest that iron oxide nanoparticle

  11. In situ generation of o-iodoxybenzoic acid (IBX) and the catalytic use of it in oxidation reactions in the presence of Oxone as a co-oxidant.

    PubMed

    Thottumkara, Arun P; Bowsher, Michael S; Vinod, Thottumkara K

    2005-07-01

    [structure: see text] Catalytic use of o-iodoxybenzoic acid (IBX) in the presence of Oxone as a co-oxidant is demonstrated for the oxidation of primary and secondary alcohols in user- and eco-friendly solvent mixtures. Also demonstrated is the in situ (re)oxidation of 2-iodosobenzoic acid (IBA) and even commercially available 2-iodobenzoic acid (2IBAcid) by Oxone to IBX allowing one to use these less hazardous reagents, in place of potentially explosive IBX, as catalytic oxidants.

  12. 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.

  13. UPR in palmitate-treated pancreatic beta-cells is not affected by altering oxidation of the fatty acid

    PubMed Central

    2011-01-01

    Background Elevated levels of lipids are detrimental for beta-cell function and mass. One of the mechanisms of how fatty acids induce apoptosis is development of the unfolded protein response (UPR). It is still far from understood how fatty acids activate the UPR, however. Methods We examined how palmitate-induced activation of the UPR was affected by altering the metabolism of the fatty acid in insulin-secreting INS-1E and MIN6 cell lines and intact human islets. To increase oxidation, we used low glucose (5.5 mM) or AICAR; and to reduce oxidation, we used high glucose (25 mM) or etomoxir. UPR was measured after 3, 24 and 48 hours of palmitate treatment. Results Modulation of palmitate oxidation by either glucose or the pharmacological agents did not affect palmitate-induced UPR activation. Conclusion Our finding suggests that other factors than oxidation of palmitate play a role in the activation of UPR in fatty acid-treated beta-cells. PMID:21978671

  14. Chloroperoxidase-catalyzed enantioselective oxidation of methyl phenyl sulfide with dihydroxyfumaric acid/oxygen or ascorbic acid/oxygen as oxidants.

    PubMed

    Pasta; Carrea; Monzani; Gaggero; Colonna

    1999-02-01

    The chloroperoxidase catalyzed oxidation of methyl phenyl sulfide to (R)-methyl phenyl sulfoxide was investigated, both in batch and membrane reactors, using as oxidant H2O2, or O2 in the presence of either dihydroxyfumaric acid or ascorbic acid. The effects of pH and nature and concentration of the oxidants on the selectivity, stability, and productivity of the enzyme were evaluated. The highest selectivity was displayed by ascorbic acid/O2, even though the activity of chloroperoxidase with this system was lower than that obtained with the others. When the reaction was carried out in a membrane reactor, it was possible to reuse the enzyme for several conversion cycles. The results obtained with ascorbic acid/O2 and dihydroxyfumaric acid/O2 as oxidants do not seem to be compatible with either a mechanism involving hydroxyl radicals as the active species or with the hypothesis that oxidation occurs through the initial formation of H2O2. Copyright 1999 John Wiley & Sons, Inc.

  15. The hepatoprotection of caffeic acid and rosmarinic acid, major compounds of Perilla frutescens, against t-BHP-induced oxidative liver damage.

    PubMed

    Yang, Sung-Yong; Hong, Chung-Oui; Lee, Gung Pyo; Kim, Cheong-Tae; Lee, Kwang-Won

    2013-05-01

    Perilla frutescens leaves are often used in East Asian gourmet food. In this study, we investigated the hepatoprotective effects of caffeic acid (CA), rosmarinic acid (RA), and their combination. P. frutescens contains 1.32μg CA/mg dry material (DM) and 26.84μg RA/mg DM analyzed by HPLC-DAD and HPLC-MS. CA remarkably reduced the oxidative damage than rosmarinic acid in an in vitro study. Oral intubation with CA or RA alone for five days was conducted prior to treatment with a single dose of tert-butyl hydroperoxide (0.5mmol/kg b.w., i.p.), which led to a significant reduction of indicators of hepatic toxicity, such as aspartate aminotransferase, alanine aminotransferase, oxidized glutathione, lipid peroxidation and enzyme activities related to antioxidant such as catalase, glutathione peroxidase and superoxide dismutase. Interestingly, compared to treatment with CA or RA alone, a combination of both compounds more increased the endogenous antioxidant enzymes and glutathione (GSH) and decreased lipid peroxidation in livers. These results suggest that CA from perilla leaves plays a role in the increased hepatic GSH concentration, and shows an additive hepatic protection with RA against oxidative hepatic damage.

  16. 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

  17. 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

  18. Treatment of facial molluscum contagiosum with trichloroacetic acid.

    PubMed

    Bard, Susan; Shiman, Michael I; Bellman, Betty; Connelly, Elizabeth Alvarez

    2009-01-01

    Molluscum contagiosum (MC) virus is a common cutaneous infection in the pediatric population, most commonly affecting school-aged children. Spontaneous clearing of lesions usually occurs over time; however, treatment is often sought due to cosmetic significance, pruritus, or concerns of transmission and autoinoculation. Chemical destruction with cantharidin, which is derived from blister beetle extract, is very safe and highly effective, making it the treatment of choice in the pediatric population. However, treatment of facial lesions or those in the diaper area are not recommended with this agent. Trichloroacetic acid is a safe and effective agent frequently utilized in dermatologic practice, most commonly in the treatment of verrucae. We have successfully used topical trichloroacetic acid to treat facial molluscum contagiousum and present the following technique for proper application. PMID:19689517

  19. [The importance of γ-linolenic acid in the prevention and treatment].

    PubMed

    Białek, Małgorzata; Rutkowska, Jarosława

    2015-01-01

    The etiology of diet-related disorders is closely associated with dietary factors. A special role is attributed to intake of fat and fatty acid profile, both quantitative and qualitative. For prevention and treatment of the abovementioned diseases a proper supply of unsaturated fatty acids plays a significant role, because of their particular importance to health. γ-Linolenic acid (GLA), with three double bonds in the carbon chain, also known as all-cis 6,9,12-octadecatrienoic acid, belongs to the n-6 family of fatty acids. It plays biologically important functions in the human body, such as being a substrate for eicosanoids synthesis, involvement in the transport and oxidation of cholesterol, and being one of the components of lipid membrane. Its inadequate dietary intake or impaired formation is the cause of many inflammatory and degenerative diseases. A rich source of this fatty acid is vegetable oils, until recently used mainly in folk medicine. Nowadays, studies conducted both in animal models and in humans suggest its health-promoting properties in the prevention and treatment of atopic dermatitis, cardiovascular diseases, diabetes, cancers and rheumatoid arthritis. PMID:26270516

  20. 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

  1. 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.

  2. Selective Production of Formic Acid by Hydrothermal Alkaline Oxidation of Carbohydrates

    NASA Astrophysics Data System (ADS)

    Yun, J.; Li, G.; Enomoto, H.; Jin, F.

    2007-03-01

    Formic acid is a familiar product in hydrothermal oxidation of carbohydrates and is an important organic compound. In this study, the production of formic acid from the hydrothermal oxidation of glucose with and without the addition of alkali was investigated with temperature varying from 250 to 300°C, reaction time varying from 30 s to 240 s, and oxygen supply varying from 60 % to 140 %. Results showed that the highest yield of formic acid was only about 24 % in hydrothermal oxidation of glucose without the addition of alkali. It is very interest that the oxidation of glucose with the addition of alkali showed a high selective and effective for the production of formic acid. An excellent formic acid yield of about 74 % was achieved, which occurred at 250°C for 60 s with 120 % oxygen supply and the KOH concentration of 1.25 M.

  3. 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.

  4. Arsenic-induced oxidative myocardial injury: protective role of arjunolic acid.

    PubMed

    Manna, Prasenjit; Sinha, Mahua; Sil, Parames C

    2008-03-01

    Arsenic, one of the most harmful metalloids, is ubiquitous in the environment. The present study has been carried out to investigate the protective role of a triterpenoid saponin, arjunolic acid (AA) against arsenic-induced cardiac oxidative damage. In the study, NaAsO2 was chosen as the source of arsenic. The free radical scavenging activity and the effect of AA on the intracellular antioxidant power were determined from its 2,2-diphenyl-1-picryl hydrazyl radical scavenging ability and ferric reducing/antioxidant power assay, respectively. Oral administration of NaAsO2 at a dose of 10 mg/kg body weight for 2 days caused significant accumulation of arsenic in cardiac tissues of the experimental mice in association with the reduction in cardiac antioxidant enzymes activities, namely superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase and glutathione peroxidase. Arsenic intoxication also decreased the cardiac glutathione (GSH) and total thiol contents and increased the levels of oxidized glutathione (GSSG), lipid peroxidation end products and protein carbonyl content. Treatment with AA at a dose of 20 mg/kg body weight for 4 days prior to NaAsO2 intoxication protected the cardiac tissue from arsenic-induced oxidative impairment. In addition to oxidative stress, arsenic administration increased total cholesterol level as well as the reduced high-density lipoprotein cholesterol level in the sera of the experimental mice. AA pretreatment, however, could prevent this hyperlipidemia. Histological studies on the ultrastructural changes in cardiac tissue supported the protective activity of AA also. Combining all, results suggest that AA could protect cardiac tissues against arsenic-induced oxidative stress probably due to its antioxidant property. PMID:18197399

  5. Arsenic-induced oxidative myocardial injury: protective role of arjunolic acid.

    PubMed

    Manna, Prasenjit; Sinha, Mahua; Sil, Parames C

    2008-03-01

    Arsenic, one of the most harmful metalloids, is ubiquitous in the environment. The present study has been carried out to investigate the protective role of a triterpenoid saponin, arjunolic acid (AA) against arsenic-induced cardiac oxidative damage. In the study, NaAsO2 was chosen as the source of arsenic. The free radical scavenging activity and the effect of AA on the intracellular antioxidant power were determined from its 2,2-diphenyl-1-picryl hydrazyl radical scavenging ability and ferric reducing/antioxidant power assay, respectively. Oral administration of NaAsO2 at a dose of 10 mg/kg body weight for 2 days caused significant accumulation of arsenic in cardiac tissues of the experimental mice in association with the reduction in cardiac antioxidant enzymes activities, namely superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase and glutathione peroxidase. Arsenic intoxication also decreased the cardiac glutathione (GSH) and total thiol contents and increased the levels of oxidized glutathione (GSSG), lipid peroxidation end products and protein carbonyl content. Treatment with AA at a dose of 20 mg/kg body weight for 4 days prior to NaAsO2 intoxication protected the cardiac tissue from arsenic-induced oxidative impairment. In addition to oxidative stress, arsenic administration increased total cholesterol level as well as the reduced high-density lipoprotein cholesterol level in the sera of the experimental mice. AA pretreatment, however, could prevent this hyperlipidemia. Histological studies on the ultrastructural changes in cardiac tissue supported the protective activity of AA also. Combining all, results suggest that AA could protect cardiac tissues against arsenic-induced oxidative stress probably due to its antioxidant property.

  6. Peroxisomal beta-oxidation of branched chain fatty acids in rat liver. Evidence that carnitine palmitoyltransferase I prevents transport of branched chain fatty acids into mitochondria.

    PubMed

    Singh, H; Beckman, K; Poulos, A

    1994-04-01

    Fatty acid beta-oxidation was investigated in highly purified mitochondrial and peroxisomal preparations from rat liver. Under isotonic conditions, pristanic and homophytanic acid beta-oxidation in purified peroxisomes was severalfold greater compared to the oxidation in purified mitochondria. Branched chain fatty acid beta-oxidation in purified mitochondria was very low, and the oxidation was not stimulated by exogenous L-carnitine or L-malate. In contrast, stearic acid beta-oxidation by purified mitochondria depended upon exogenous L-carnitine, and the oxidation was stimulated by L-malate. Both mitochondrial and peroxisomal beta-oxidation of branched chain fatty acids was strongly inhibited by fatty acid-free bovine serum albumin, whereas stearic acid oxidation was either unaffected or slightly inhibited by bovine serum albumin. The results presented clearly indicate that branched chain fatty acids are mainly degraded in peroxisomes in rat liver. Branched chain fatty acids were efficiently converted to coenzyme A thioesters by purified mitochondria, peroxisomes, and microsomes. Although pristanic and phytanic acids were rapidly converted to pristanoyl-CoA and phytanoyl-CoA, respectively, they were not converted to carnitine esters by mitochondrial outer membranes. The results indicate that acyl-CoA synthetase and carnitine acyltransferase located at the mitochondrial outer membranes regulate entry of branched chain fatty acids into mitochondria. Mitochondrial carnitine acyltransferase I appears to be highly specific for straight chain fatty acids and restricts entry of branched chain fatty acids into mitochondria. Thus, branched chain fatty acids which cannot be transported across the mitochondrial membranes via the carnitine acyltransferase system are directed to peroxisomes for beta-oxidation. The results reported indicate that phytanic acid, the fatty acid which can be initially degraded by alpha-oxidation due to the presence of a beta-methyl group in the

  7. Foraging at wastewater treatment works affects brown adipose tissue fatty acid profiles in banana bats

    PubMed Central

    Hill, Kate; van Aswegen, Sunet; Schoeman, M. Corrie; Claassens, Sarina; Jansen van Rensburg, Peet; Naidoo, Samantha; Vosloo, Dalene

    2016-01-01

    ABSTRACT In this study we tested the hypothesis that the decrease in habitat quality at wastewater treatment works (WWTW), such as limited prey diversity and exposure to the toxic cocktail of pollutants, affect fatty acid profiles of interscapular brown adipose tissue (iBrAT) in bats. Further, the antioxidant capacity of oxidative tissues such as pectoral and cardiac muscle may not be adequate to protect those tissues against reactive molecules resulting from polyunsaturated fatty acid auto-oxidation in the WWTW bats. Bats were sampled at two urban WWTW, and two unpolluted reference sites in KwaZulu-Natal, South Africa. Brown adipose tissue (BrAT) mass was lower in WWTW bats than in reference site bats. We found lower levels of saturated phospholipid fatty acids and higher levels of mono- and polyunsaturated fatty acids in WWTW bats than in reference site bats, while C18 desaturation and n-6 to n-3 ratios were higher in the WWTW bats. This was not associated with high lipid peroxidation levels in pectoral and cardiac muscle. Combined, these results indicate that WWTW bats rely on iBrAT as an energy source, and opportunistic foraging on abundant, pollutant-tolerant prey may change fatty acid profiles in their tissue, with possible effects on mitochondrial functioning, torpor and energy usage. PMID:26740572

  8. Photolytic degradation of chlorophenols from industrial wastewaters by organic oxidants peroxy acetic acid, para nitro benzoic acid and methyl ethyl ketone peroxide: identification of reaction products.

    PubMed

    Sharma, Swati; Mukhopadhyay, Mausumi; Murthy, Zagabathuni Venkata Panchakshari

    2014-01-01

    In this investigation, chlorophenol (CP) containing industrial wastewater was remediated by ultraviolet irradiation in conjunction with organic oxidants, peroxy acetic acid (PAA); para nitro benzoic acid (PNBA); and methyl ethyl ketone peroxide (MEKP). CP mineralization was studied with regard to chemical oxygen demand (COD) and chloride ion release under identical test conditions. COD depletion to the extent of 81% by PAA, 66% by PNBA, and 67% by MEKP was noted along with an upwardly mobile trend of chloride ion release upon irradiation of samples at 254 nm. A 90-99% decrease in CP concentration (as per high pressure liquid chromatography (HPLC) analysis) was achieved with an additional 15.0 ml of organic oxidant in all cases. Gas chromatography high resolution mass spectroscopy (GC-HRMS) results also indicated the formation of such reaction products as are free from chlorine substitutions. This treatment also leads to total decolorization of the collected samples. PMID:24647192

  9. Cements containing syringic acid esters -- o-ethoxybenzoic acid and zinc oxide.

    PubMed

    Brauer, G M; Stansbury, J W

    1984-02-01

    Fissure caries is reduced when syringic acid is incorporated into a cariogenic diet of rats. It was therefore of interest to synthesize n-hexyl and 2-ethylhexyl syringate and to evaluate the properties of cements with these compounds as ingredients. Liquids containing the esters dissolved in o-ethoxybenzoic acid (EBA) - when mixed with powders made up from zinc oxide, aluminum oxide, and hydrogenated rosin - hardened in from four to nine min. Properties of the cements were determined, when possible, according to ANSI/ADA specification tests. Depending on the powder-liquid ratio employed, we obtained compositions with varying physical properties desirable for different dental applications. The syringate cements, compared with the commonly used ZOE materials, have improved compressive and tensile strength, lower water solubility, do not inhibit polymerization, and are compatible with acrylic monomers. These cements pass, and mostly greatly exceed, the requirements for ZOE-type restorative materials. They also bond significantly to resins, composites, and non-precious metals. The bond strength is somewhat less than that of n-hexyl vanillate-EBA cement, but greatly exceeds the adhesion to various substrates of ZOE luting agents. Cements containing n-hexyl syringate were somewhat brittle. Best results were obtained with liquid compositions containing 5% 2-ethylhexyl syringate, 7% n-hexyl vanillate, and 88% EBA, which yielded non-brittle materials. These cements, because of the syringate ingredient, may possess caries-reducing properties. Thus, perhaps in conjunction with fluoride additives, they would be useful as insulating bases, pulp capping agents, root canal sealers, soft tissue packs, or intermediate restoratives.

  10. Refsum disease: a defect in the alpha-oxidation of phytanic acid in peroxisomes.

    PubMed

    Singh, I; Pahan, K; Singh, A K; Barbosa, E

    1993-10-01

    The oxidation of phytanic acid to pristanic acid was previously demonstrated to be deficient in monolayer cultures of skin fibroblasts (Herndon et al. 1969. J. Clin. Invest. 48: 1017-1032). However, identification of subcellular organelle with deficient enzyme activity has not been established. To define the subcellular organelle with deficient enzyme activity in the catabolism of phytanic acid, we measured the oxidation of [1-14C] phytanic acid to 14CO2 and pristanic acid in different subcellular organelles isolated from cultured skin fibroblasts from control and Refsum patients. The rates of oxidation of phytanic acid in peroxisomes, mitochondria, and endoplasmic reticulum were 37.1 +/- 2.65, 1.9 +/- 0.3, and 0.4 +/- 0.07 pmol/h per mg protein, respectively, from control fibroblasts. The phytanic acid oxidation activity in mitochondria (2.04 +/- 0.7 pmol/h per mg protein) and endoplasmic reticulum (0.43 +/- 0.2 pmol/h per mg protein) from Refsum fibroblasts was similar to control fibroblasts. However, phytanic acid oxidation in peroxisomes from Refsum fibroblasts was not detected at all the protein concentrations tested. On the other hand, the peroxisomes from Refsum fibroblasts had normal rates of activation and oxidation of palmitic and lignoceric acids, suggesting that the peroxisomes isolated from Refsum fibroblasts were metabolically active. The phytanoyl-CoA ligase, the first enzyme in the alpha-oxidation pathway, had activity similar to that in peroxisomes from control (9.86 +/- 0.09 nmol/h per mg protein) and Refsum (10.25 +/- 0.31 nmol/h per mg protein) fibroblasts. The data described here clearly demonstrate that pathognomonic accumulation of phytanic acid in patients with Refsum disease is due to the deficient activity of peroxisomal alpha-oxidation enzyme system.

  11. Fluorescence analysis of NOM degradation by photocatalytic oxidation and its potential to mitigate membrane fouling in drinking water treatment.

    PubMed

    Nerger, Bryan A; Peiris, Ramila H; Moresoli, Christine

    2015-10-01

    This study examined the photocatalytic oxidation of natural organic matter (NOM) as a method to mitigate membrane fouling in drinking water treatment. ZnO and TiO2 photocatalysts were tested in concentrations ranging from 0.05 g L(-1) to 0.5 g L(-1). Fluorescence peaks were used as the primary method to characterize the degradation of three specific NOM components - fulvic acid-like humic substances, humic acid-like humic substances, and protein-like substances during photocatalytic oxidation. Fluorescence peaks and Liquid Chromatography-Organic Carbon Detection (LC-OCD) analysis indicated that higher NOM degradation was obtained by photocatalytic oxidation with ZnO than with TiO2. Treatment of the feed water by ZnO photocatalytic oxidation was successful in reducing considerably the extent of hydraulically reversible and irreversible membrane fouling during ultrafiltration (UF) compared to feed water treatment with TiO2. Fouling during UF of water subjected to photocatalytic oxidation appeared to be caused by low molecular weight constituents of NOM generated during photocatalytic oxidation.

  12. Ascorbic acid ameliorates oxidative stress and inflammation in dextran sulfate sodium-induced ulcerative colitis in mice

    PubMed Central

    Yan, Haiyan; Wang, Hongjuan; Zhang, Xiaoli; Li, Xiaoqin; Yu, Jing

    2015-01-01

    Ascorbic acid (AA) has been shown to exert beneficial effects, including mitigating oxidative stress and inhibiting inflammation. However, the preventative effect of vitamin C in chronic inflammatory diseases such as inflammatory bowel disease (IBD) remains unclear. In our study, we investigated the anti-inflammatory effects of AA and possible mechanism involved in inhibiting dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. Male C57BL/6 mice were randomly divided to three groups: control group, DSS group, and DSS plus ascorbic acid treated group. Several clinical and inflammatory parameters as well as oxidative stress were evaluated. The results demonstrated that ascorbic acid significantly reduced clinical signs, inflammatory cytokines, myeloperoxidase (MPO) and malonaldehyde (MDA) activities, whereas the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were increased in DSS-induced mice. In addition, ascorbic acid was capable of inhibiting NF-κB, COX-2 and iNOS expression in the colonic. Taken together, these findings suggest that ascorbic acid contributes to the reduction of oxidative stress and inflammatory response in DSS-induced colitis and exerts the potential to prevent and clinical treatment of inflammatory bowel disease. PMID:26884937

  13. Neridronic acid for the treatment of bone metabolic diseases.

    PubMed

    Gatti, Davide; Viapiana, Ombretta; Idolazzi, Luca; Fracassi, Elena; Adami, Silvano

    2009-10-01

    Neridronic acid (6-amino-1-idroxyesilidene-1,1-bisphosphonate) is a nitrogen-containing bisphosphonate licensed in Italy for the treatment of osteogenesis imperfecta and Paget's disease of bone. The pharmacodynamic profile is similar to that of other nitrogen-containing bisphosphonates and is characterized by its high affinity for bone tissue particularly at sites undergoing a process of remodeling. In growing children affected by osteogenesis imperfect, neridronic acid rapidly increases bone mineral density as measured by dual X-ray absortiometry and this is associated with a significant decrease in fracture cumulative number. Similar results have been obtained also in newborns (< 12 month old) and in adult patients. In Paget's disease of bone, 200 mg intravenous neridronic acid is associated with a 65% rate of full remission and a biochemical response (decrease of > 75% of bone turnover markers) in 95% of the patients. Neridronic acid treatment has been reported to be effective also in other skeletal diseases such as osteoporosis, algodystrophy, hypercalcemia of malignancy and bone metastasis. Neridronic acid has been developed only for parenteral use, and it is the only one used as intramuscular injection. This avoids all the limitations of oral bisphosphonates and may be offered for a home treatment with simple nursing assistance. PMID:19761412

  14. Myotoxic reactions to lipid-lowering therapy are associated with altered oxidation of fatty acids.

    PubMed

    Phillips, Paul S; Ciaraldi, Theodore P; Kim, Dong-Lim; Verity, M Anthony; Wolfson, Tanya; Henry, Robert R

    2009-02-01

    Despite exceptional efficacy and safety, fear of muscle toxicity remains a major reason statins are underutilized. Evidence suggests that statin muscle toxicity may be mediated by abnormalities in lipid metabolism. To test the hypothesis that myotubes from patients intolerant of lipid-lowering therapies have abnormal fatty acid oxidation (FAO) responses we compared muscle from 11 subjects with statin intolerance (Intolerant) with muscle from seven statin-naive volunteers undergoing knee arthroplasty (Comparator). Gross muscle pathology was graded and skeletal muscle cell cultures were produced from each subject. FAO was assessed following treatment with increasing statin concentrations. There was no difference in muscle biopsy myopathy scores between the groups. Basal octanoate oxidation was greater in Intolerant than in Comparator subjects (P = 0.03). Lovastatin-stimulated palmitate oxidation tended to be greater for Intolerant compared to Control subjects' myotubes (P = 0.07 for 5 microM and P = 0.06 for 20 microM lovastatin). In conclusion abnormalities in FAO of Intolerant subjects appear to be an intrinsic characteristic of these subjects that can be measured in their cultured myotubes.

  15. Ferrates: greener oxidants with multimodal action in water treatment technologies.

    PubMed

    Sharma, Virender K; Zboril, Radek; Varma, Rajender S

    2015-02-17

    CONSPECTUS: One of the biggest challenges for humanity in the 21st century is easy access to purified and potable water. The presence of pathogens and toxins in water causes more than two million deaths annually, mostly among children under the age of five. Identifying and deploying effective and sustainable water treatment technologies is critical to meet the urgent need for clean water globally. Among the various agents used in the purification and treatment of water, iron-based materials have garnered particular attention in view of their special attributes such as their earth-abundant and environmentally friendly nature. In recent years, higher-valent tetraoxy iron(VI) (Fe(VI)O4(2-), Fe(VI)), commonly termed, ferrate, is being explored for a broad portfolio of applications, including a greener oxidant in synthetic organic transformations, a water oxidation catalyst, and an efficient agent for abatement of pollutants in water. The use of Fe(VI) as an oxidant/disinfectant and further utilization of the ensuing iron(III) oxides/hydroxide as coagulants are other additional attributes of ferrate for water treatment. This multimodal action and environmentally benign character of Fe(VI) are key advantages over other commonly used oxidants (e.g., chlorine, chlorine dioxide, permanganate, hydrogen peroxide, and ozone). This Account discusses current state-of-the-art applications of Fe(VI) and the associated unique chemistry of these high-valence states of iron. The main focus centers around the description and salient properties of ferrate species involving various electron transfer and oxygen-atom transfer pathways in terms of presently accepted mechanisms. The mechanisms derive the number of electron equivalents per Fe(VI) (i.e., oxidation capacity) in treating various contaminants. The role of pH in the kinetics of the reactions and in determining the removal efficiency of pollutants is highlighted; the rates of competing reactions of Fe(VI) with itself, water, and

  16. Ferrates: greener oxidants with multimodal action in water treatment technologies.

    PubMed

    Sharma, Virender K; Zboril, Radek; Varma, Rajender S

    2015-02-17

    CONSPECTUS: One of the biggest challenges for humanity in the 21st century is easy access to purified and potable water. The presence of pathogens and toxins in water causes more than two million deaths annually, mostly among children under the age of five. Identifying and deploying effective and sustainable water treatment technologies is critical to meet the urgent need for clean water globally. Among the various agents used in the purification and treatment of water, iron-based materials have garnered particular attention in view of their special attributes such as their earth-abundant and environmentally friendly nature. In recent years, higher-valent tetraoxy iron(VI) (Fe(VI)O4(2-), Fe(VI)), commonly termed, ferrate, is being explored for a broad portfolio of applications, including a greener oxidant in synthetic organic transformations, a water oxidation catalyst, and an efficient agent for abatement of pollutants in water. The use of Fe(VI) as an oxidant/disinfectant and further utilization of the ensuing iron(III) oxides/hydroxide as coagulants are other additional attributes of ferrate for water treatment. This multimodal action and environmentally benign character of Fe(VI) are key advantages over other commonly used oxidants (e.g., chlorine, chlorine dioxide, permanganate, hydrogen peroxide, and ozone). This Account discusses current state-of-the-art applications of Fe(VI) and the associated unique chemistry of these high-valence states of iron. The main focus centers around the description and salient properties of ferrate species involving various electron transfer and oxygen-atom transfer pathways in terms of presently accepted mechanisms. The mechanisms derive the number of electron equivalents per Fe(VI) (i.e., oxidation capacity) in treating various contaminants. The role of pH in the kinetics of the reactions and in determining the removal efficiency of pollutants is highlighted; the rates of competing reactions of Fe(VI) with itself, water, and

  17. The rationale for preventing cancer cachexia: targeting excessive fatty acid oxidation.

    PubMed

    Qian, Chao-Nan

    2016-07-21

    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.

  18. Hydrochloric acid-pumice treatment of fluorosis-stained enamel.

    PubMed

    Jagger, R G; al Rayes, S A

    1990-02-01

    The management of dark staining of teeth caused by dental fluorosis is discussed. The results of treatment of 20 patients with dental fluorosis by a hydrochloric acid-pumice technique are described. All patients showed considerable improvement in colour which was maintained for review periods of (up to) two years.

  19. DEVELOPMENT OF SRB TREATMENT SYSTEMS FOR ACID MINE DRAINAGE

    EPA Science Inventory

    Over the past decade, significant advances have been made in the development of sulfate- reducing bacteria (SRB) technology to treat acid mine drainage (AMD), Bench-scale testing, field demonstrations, and engineered applications of SRBs for the treatment of AMD will be presented...

  20. Treatment of real industrial wastewater using the combined approach of advanced oxidation followed by aerobic oxidation.

    PubMed

    Ramteke, Lokeshkumar P; Gogate, Parag R

    2016-05-01

    Fenton oxidation and ultrasound-based pretreatment have been applied to improve the treatment of real industrial wastewater based on the use of biological oxidation. The effect of operating parameters such as Fe(2+) loading, contact time, initial pH, and hydrogen peroxide loading on the extent of chemical oxygen demand (COD) reduction and change in biochemical oxygen demand (BOD5)/COD ratio has been investigated. The optimum operating conditions established for the pretreatment were initial pH of 3.0, Fe(2+) loading of 2.0, and 2.5 g L(-1) for the US/Fenton/stirring and Fenton approach, respectively, and temperature of 25 °C with initial H2O2 loading of 1.5 g L(-1). The use of pretreatment resulted in a significant increase in the BOD5/COD ratio confirming the production of easily digestible intermediates. The effect of the type of sludge in the aerobic biodegradation was also investigated based on the use of primary activated sludge (PAS), modified activated sludge (MAS), and activated sludge (AS). Enhanced removal of the pollutants as well as higher biomass yield was observed for MAS as compared to PAS and AS. The use of US/Fenton/stirring pretreatment under the optimized conditions followed by biological oxidation using MAS resulted in maximum COD removal at 97.9 %. The required hydraulic retention time for the combined oxidation system was also significantly lower as compared to only biological oxidation operation. Kinetic studies revealed that the reduction in the COD followed a first-order kinetic model for advanced oxidation and pseudo first-order model for biodegradation. The study clearly established the utility of the combined technology for the effective treatment of real industrial wastewater.

  1. Oxidation of linoleic acid encapsulated with gum arabic or maltodextrin by spray-drying.

    PubMed

    Minemoto, Y; Hakamata, K; Adachi, S; Matsuno, R

    2002-01-01

    Linoleic acid was emulsified with gum arabic or maltodextrin at various weight ratios of the acid to the polysaccharide in the presence or absence of a small-molecule emulsifier. The emulsions were spray-dried to produce microcapsules. Emulsions prepared with gum arabic were smaller in droplet size and more stable than those prepared with maltodextrin, and linoleic acid in a gum arabic-based microcapsule was also most resistant to oxidation than that in a maltodextrin-based microcapsule. Although the oil droplet size in the emulsion with maltodextrin decreased and the emulsion stability was improved by addition of a small-molecule emulsifier to linoleic acid, the oxidative stability of the encapsulated linoleic acid was not significantly improved. Encapsulated linoleic acid of small droplet size oxidized more slowly than that of large droplet size.

  2. 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.

  3. 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.

  4. Taurine treatment protects against chronic nicotine-induced oxidative changes.

    PubMed

    Sener, Göksel; Ozer Sehirli, A; Ipçi, Yeşim; Cetinel, Sule; Cikler, Esra; Gedik, Nursal; Alican, Inci

    2005-04-01

    Experiments have shown that chronic nicotine administration caused oxidative damage in various organs by increasing lipid peroxidation products and decreasing the activity of endogenous antioxidants. The aim of this study was to investigate the effects of taurine treatment on nicotine-induced oxidative changes in rat thoracic aorta and heart and to explore the possible mechanisms of action. Male Wistar albino rats (200-250 g) were injected with nicotine hydrogen bitartrate (0.6 mg/kg; i.p.) or saline for 21 days. Taurine was administered (50 mg/kg; i.p.) alone or along with nicotine injections. After decapitation, the thoracic aorta and heart tissues were excised. The aorta was used for in vitro contractility studies or stored along with the heart samples for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Tissue samples were also examined histologically. Serum samples were stored for the measurement of MDA, GSH and lactate dehydrogenase (LDH) activity. Chronic nicotine treatment impaired both the contraction and relaxation responses of the aortic rings to phenylephrine and acetylcholine, respectively. It increased lipid peroxidation, MPO levels and tissue collagen content of both aorta and heart samples. Taurine supplementation to nicotine-treated animals reversed the contractile dysfunction and restored the endogenous GSH levels and decreased high lipid peroxidation and MPO activities in both tissues. These data suggest that taurine supplementation effectively attenuates the oxidative damage because of chronic nicotine administration possibly by its antioxidant effects.

  5. Folic acid and melatonin ameliorate carbon tetrachloride-induced hepatic injury, oxidative stress and inflammation in rats

    PubMed Central

    2013-01-01

    This study investigated the protective effects of melatonin and folic acid against carbon tetrachloride (CCl4)-induced hepatic injury in rats. Oxidative stress, liver function, liver histopathology and serum lipid levels were evaluated. The levels of protein kinase B (Akt1), interferon gamma (IFN-γ), programmed cell death-receptor (Fas) and Tumor necrosis factor-alpha (TNF-α) mRNA expression were analyzed. CCl4 significantly elevated the levels of lipid peroxidation (MDA), cholesterol, LDL, triglycerides, bilirubin and urea. In addition, CCl4 was found to significantly suppress the activity of both catalase and glutathione (GSH) and decrease the levels of serum total protein and HDL-cholesterol. All of these parameters were restored to their normal levels by treatment with melatonin, folic acid or their combination. An improvement of the general hepatic architecture was observed in rats that were treated with the combination of melatonin and folic acid along with CCl4. Furthermore, the CCl4-induced upregulation of TNF-α and Fas mRNA expression was significantly restored by the three treatments. Melatonin, folic acid or their combination also restored the baseline levels of IFN-γ and Akt1 mRNA expression. The combination of melatonin and folic acid exhibited ability to reduce the markers of liver injury induced by CCl4 and restore the oxidative stability, the level of inflammatory cytokines, the lipid profile and the cell survival Akt1 signals. PMID:23374533

  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. Parallel electrochemical treatment system and application for identifying acid-stable oxygen evolution electrocatalysts.

    PubMed

    Jones, Ryan J R; Shinde, Aniketa; Guevarra, Dan; Xiang, Chengxiang; Haber, Joel A; Jin, Jian; Gregoire, John M

    2015-02-01

    Many energy technologies require electrochemical stability or preactivation of functional materials. Due to the long experiment duration required for either electrochemical preactivation or evaluation of operational stability, parallel screening is required to enable high throughput experimentation. Imposing operational electrochemical conditions to a library of materials in parallel creates several opportunities for experimental artifacts. We discuss the electrochemical engineering principles and operational parameters that mitigate artifacts in the parallel electrochemical treatment system. We also demonstrate the effects of resistive losses within the planar working electrode through a combination of finite element modeling and illustrative experiments. Operation of the parallel-plate, membrane-separated electrochemical treatment system is demonstrated by exposing a composition library of mixed-metal oxides to oxygen evolution conditions in 1 M sulfuric acid for 2 h. This application is particularly important because the electrolysis and photoelectrolysis of water are promising future energy technologies inhibited by the lack of highly active, acid-stable catalysts containing only earth abundant elements.

  8. Involvement of Nitric Oxide on Calcium Mobilization and Arachidonic Acid Pathway Activation during Platelet Aggregation with different aggregating agonists

    PubMed Central

    Banerjee, Debipriya; Mazumder, Sahana; Kumar Sinha, Asru

    2016-01-01

    Platelet aggregation by different aggregating agonists is essential in the normal blood coagulation process, the excess of which caused acute coronary syndrome (ACS). In all cases, the activation of arachidonic acid by cycloxygenase was needed for the synthesis of thromboxane A2 (TXA2) but the mechanism of arachidonic acid release in platelets remains obscure. Studies were conducted to determine the role of nitric oxide (NO), if any, on the release of arachidonic acid in platelets. The cytosolic Ca2+ was visualized and quantitated by fluorescent spectroscopy by using QUIN-2. NO was measured by methemoglobin method. Arachidonic acid was determined by HPLC. TXA2 was measured as ThromboxaneB2 (TXB2) by ELISA. Treatment of platelets in platelet-rich plasma (PRP) with different aggregating agents resulted in the inhibition of nitric oxide synthase (NOS) which inhibited the production of NO synthesis and increased TXA2 synthesis. Furthermore, the treatment of washed PRP with different platelet aggregating agents resulted in the increase of [Ca2+] in nM ranges. In contrast, the pre-treatment of washed PRP with aspirin increased platelet NO level and inhibited the Ca2+ mobilization and TXA2 synthesis. These results indicated that the aggregation of platelets by different aggregating agonists was caused by the cytosolic Ca2+ mobilization due to the inhibition of NOS. PMID:27127451

  9. Comparison of clindamycin 1% and benzoyl peroxide 5% gel to a novel composition containing salicylic acid, capryloyl salicylic acid, HEPES, glycolic acid, citric acid, and dioic acid in the treatment of acne vulgaris.

    PubMed

    Baumann, Leslie S; Oresajo, Christian; Yatskayer, Margarita; Dahl, Amanda; Figueras, Kristian

    2013-03-01

    This study evaluated the tolerance and efficacy of 2 facial skin products in subjects with acne using the following acne treatments: 1) treatment A, a combination of salicylic acid, capryloyl salicylic acid, HEPES, glycolic acid, citric acid, and dioic acid, and 2) treatment B (BenzaClin®, clindamycin 1% and benzoyl peroxide 5% gel). The treatment design included the split-face application of treatment A and treatment B and the full-face application of the cleanser, moisturizer, and sunscreen. Data were collected through physician visual assessments, subject irritation questionnaires and assessments, along with clinical photography. Results showed similar tolerance and efficacy for both treatments.

  10. 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

  11. 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

  12. 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.

  13. The study of leachate treatment by using three advanced oxidation process based wet air oxidation

    PubMed Central

    2013-01-01

    Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was put under a 10-bar pressure, at temperatures of 100, 200, and 300° as well as three retention times of 30, 60, and 90 minutes. The sample was placed at 18 stages of leachate storage ponds in Isfahan Compost Plant with the volume of 20 liters, using three WPO, WAO methods and a combination of WAO/GAC for leachate pre-treatment. Thirty percent of pure oxygen and hydrogen peroxide were applied as oxidation agents. The COD removal efficiency in WAO method is 7.8-33.3%, in BOD is 14.7-50.6%, the maximum removal percentage (efficiency) for NH4-N is 53.3% and for NO3-N is 56.4-73.9%. The removal efficiency of COD and BOD5 is 4.6%-34 and 24%-50 respectively in WPO method. Adding GAC to the reactor, the removal efficiency of all parameters was improved. The maximum removal efficiency was increased 48% for COD, 31%-43.6 for BOD5 by a combinational method, and the ratio of BOD5/COD was also increased to 90%. In this paper, WAO and WPO process was used for Leachate pre-treatment and WAO/GAC combinational process was applied for improving the organic matter removal and leachate treatment; it was also determined that the recent process is much more efficient in removing resistant organic matter. PMID:23369258

  14. Toxicogenomic response of Mycobacterium bovis BCG to peracetic acid and a comparative analysis of the M. bovis BCG response to three oxidative disinfectants.

    PubMed

    Nde, Chantal W; Toghrol, Freshteh; Jang, Hyeung-Jin; Bentley, William E

    2011-04-01

    Tuberculosis is a leading cause of death worldwide and infects thousands of Americans annually. Mycobacterium bovis causes tuberculosis in humans and several animal species. Peracetic acid is an approved tuberculocide in hospital and domestic environments. This study presents for the first time the transcriptomic changes in M. bovis BCG after treatment with 0.1 mM peracetic acid for 10 and 20 min. This study also presents for the first time a comparison among the transcriptomic responses of M. bovis BCG to three oxidative disinfectants: peracetic acid, sodium hypochlorite, and hydrogen peroxide after 10 min of treatment. Results indicate that arginine biosynthesis, virulence, and oxidative stress response genes were upregulated after both peracetic acid treatment times. Three DNA repair genes were downregulated after 10 and 20 min and cell wall component genes were upregulated after 20 min. The devR-devS signal transduction system was upregulated after 10 min, suggesting a role in the protection against peracetic acid treatment. Results also suggest that peracetic acid and sodium hypochlorite both induce the expression of the ctpF gene which is upregulated in hypoxic environments. Further, this study reveals that in M. bovis BCG, hydrogen peroxide and peracetic acid both induce the expression of katG involved in oxidative stress response and the mbtD and mbtI genes involved in iron regulation/virulence. PMID:21152916

  15. Effects of uncoated and citric acid coated cerium oxide nanoparticles, bulk cerium oxide, cerium acetate, and citric acid on tomato plants.

    PubMed

    Barrios, Ana Cecilia; Rico, Cyren M; Trujillo-Reyes, Jesica; Medina-Velo, Illya A; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2016-09-01

    Little is known about the physiological and biochemical responses of plants exposed to surface modified nanomaterials. In this study, tomato (Solanum lycopersicum L.) plants were cultivated for 210days in potting soil amended with uncoated and citric acid coated cerium oxide nanoparticles (nCeO2, CA+nCeO2) bulk cerium oxide (bCeO2), and cerium acetate (CeAc). Millipore water (MPW), and citric acid (CA) were used as controls. Physiological and biochemical parameters were measured. At 500mg/kg, both the uncoated and CA+nCeO2 increased shoot length by ~9 and ~13%, respectively, while bCeO2 and CeAc decreased shoot length by ~48 and ~26%, respectively, compared with MPW (p≤0.05). Total chlorophyll, chlo-a, and chlo-b were significantly increased by CA+nCeO2 at 250mg/kg, but reduced by bCeO2 at 62.5mg/kg, compared with MPW. At 250 and 500mg/kg, nCeO2 increased Ce in roots by 10 and 7 times, compared to CA+nCeO2, but none of the treatments affected the Ce concentration in above ground tissues. Neither nCeO2 nor CA+nCeO2 affected the homeostasis of nutrient elements in roots, stems, and leaves or catalase and ascorbate peroxidase in leaves. CeAc at 62.5 and 125mg/kg increased B (81%) and Fe (174%) in roots, while at 250 and 500mg/kg, increased Ca in stems (84% and 86%, respectively). On the other hand, bCeO2 at 62.5 increased Zn (152%) but reduced P (80%) in stems. Only nCeO2 at 62.5mg/kg produced higher total number of tomatoes, compared with control and the rest of the treatments. The surface coating reduced Ce uptake by roots but did not affect its translocation to the aboveground organs. In addition, there was no clear effect of surface coating on fruit production. To our knowledge, this is the first study comparing the effects of coated and uncoated nCeO2 on tomato plants.

  16. Effects of uncoated and citric acid coated cerium oxide nanoparticles, bulk cerium oxide, cerium acetate, and citric acid on tomato plants.

    PubMed

    Barrios, Ana Cecilia; Rico, Cyren M; Trujillo-Reyes, Jesica; Medina-Velo, Illya A; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2016-09-01

    Little is known about the physiological and biochemical responses of plants exposed to surface modified nanomaterials. In this study, tomato (Solanum lycopersicum L.) plants were cultivated for 210days in potting soil amended with uncoated and citric acid coated cerium oxide nanoparticles (nCeO2, CA+nCeO2) bulk cerium oxide (bCeO2), and cerium acetate (CeAc). Millipore water (MPW), and citric acid (CA) were used as controls. Physiological and biochemical parameters were measured. At 500mg/kg, both the uncoated and CA+nCeO2 increased shoot length by ~9 and ~13%, respectively, while bCeO2 and CeAc decreased shoot length by ~48 and ~26%, respectively, compared with MPW (p≤0.05). Total chlorophyll, chlo-a, and chlo-b were significantly increased by CA+nCeO2 at 250mg/kg, but reduced by bCeO2 at 62.5mg/kg, compared with MPW. At 250 and 500mg/kg, nCeO2 increased Ce in roots by 10 and 7 times, compared to CA+nCeO2, but none of the treatments affected the Ce concentration in above ground tissues. Neither nCeO2 nor CA+nCeO2 affected the homeostasis of nutrient elements in roots, stems, and leaves or catalase and ascorbate peroxidase in leaves. CeAc at 62.5 and 125mg/kg increased B (81%) and Fe (174%) in roots, while at 250 and 500mg/kg, increased Ca in stems (84% and 86%, respectively). On the other hand, bCeO2 at 62.5 increased Zn (152%) but reduced P (80%) in stems. Only nCeO2 at 62.5mg/kg produced higher total number of tomatoes, compared with control and the rest of the treatments. The surface coating reduced Ce uptake by roots but did not affect its translocation to the aboveground organs. In addition, there was no clear effect of surface coating on fruit production. To our knowledge, this is the first study comparing the effects of coated and uncoated nCeO2 on tomato plants. PMID:26672385

  17. Post-treatment of anaerobic reactor effluent using coagulation/oxidation followed by double filtration.

    PubMed

    Cavallini, Grasiele Soares; de Sousa Vidal, Carlos Magno; de Souza, Jeanette Beber; de Campos, Sandro Xavier

    2016-04-01

    This study evaluates the efficacy of a sanitary sewage treatment system, proposing post-treatment of the effluent generated by the upflow anaerobic sludge blanket UASB reactor, through a Fenton coagulation/oxidation ((ferric chloride (FC) or ferrous sulfate (FS) and peracetic acid (PAA)), followed by a double filtration system, composed of a gravel ascending drainage filter and a sand descending filter. Following the assessment of treatability, the system efficiency was evaluated using physicochemical and microbiological parameters. In all treatments performed in the pilot unit, total suspended solids (TSS) were completely removed, leading to a decrease in turbidity greater than 90% and close to 100% removal of total phosphorous. In the FC and PAA combination, the effluent was oxygenated prior to filtration, enabling a more significant removal of biochemical oxygen demand (BOD), which characterizes aerobic degradation even in a quick sand filter. The treatments carried out in the presence of the PAA oxidizing agent showed a more significant bleaching of the effluent. Concerning the microbiological parameters, the simultaneous use of PAA and FC contributed to the partial inactivation of the assessed microorganisms. A 65% recovery of the effluent was obtained with the proposed treatment system, considering the volume employed in filter backwashing. PMID:26611629

  18. 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.

  19. Astaxanthin improves behavioral disorder and oxidative stress in prenatal valproic acid-induced mice model of autism.

    PubMed

    Al-Amin, Md Mamun; Rahman, Md Mahbubur; Khan, Fazlur Rahman; Zaman, Fahmida; Mahmud Reza, Hasan

    2015-06-01

    Prenatal exposure to valproic acid on gestational day 12.5 may lead to the impaired behavior in the offspring, which is similar to the human autistic symptoms. To the contrary, astaxanthin shows neuroprotective effect by its antioxidant mechanism. We aimed to (i) develop mice model of autism and (ii) investigate the effect of astaxanthin on such model animals. Valproic acid (600 mg/kg) was administered intraperitoneally to the pregnant mice on gestational day 12.5. Prenatal valproic acid-exposed mice were divided into 2 groups on postnatal day 25 and astaxanthin (2mg/kg) was given to the experimental group (VPA_AST, n=10) while saline was given to the control group (VPA, n=10) for 4 weeks. Behavioral test including social interaction, open field and hot-plate were conducted on postnatal day 25 and oxidative stress markers such as lipid peroxidation, advanced protein oxidation product, nitric oxide, glutathione, and activity of superoxide dismutase and catalase were estimated on postnatal day 26 to confirm mice model of autism and on postnatal day 56 to assess the effect of astaxanthin. On postnatal day 25, prenatal valproic acid-exposed mice exhibited (i) delayed eye opening (ii) longer latency to respond painful stimuli, (iii) poor sociability and social novelty and (iv) high level of anxiety. In addition, an increased level of oxidative stress was found by determining different oxidative stress markers. Treatment with astaxanthin significantly (p<0.05) improved the behavioral disorder and reduced the oxidative stress in brain and liver. In conclusion, prenatal exposure to valproic day in pregnant mice leads to the development of autism-like features. Astaxanthin improves the impaired behavior in animal model of autism presumably by its antioxidant activity.

  20. Astaxanthin improves behavioral disorder and oxidative stress in prenatal valproic acid-induced mice model of autism.

    PubMed

    Al-Amin, Md Mamun; Rahman, Md Mahbubur; Khan, Fazlur Rahman; Zaman, Fahmida; Mahmud Reza, Hasan

    2015-06-01

    Prenatal exposure to valproic acid on gestational day 12.5 may lead to the impaired behavior in the offspring, which is similar to the human autistic symptoms. To the contrary, astaxanthin shows neuroprotective effect by its antioxidant mechanism. We aimed to (i) develop mice model of autism and (ii) investigate the effect of astaxanthin on such model animals. Valproic acid (600 mg/kg) was administered intraperitoneally to the pregnant mice on gestational day 12.5. Prenatal valproic acid-exposed mice were divided into 2 groups on postnatal day 25 and astaxanthin (2mg/kg) was given to the experimental group (VPA_AST, n=10) while saline was given to the control group (VPA, n=10) for 4 weeks. Behavioral test including social interaction, open field and hot-plate were conducted on postnatal day 25 and oxidative stress markers such as lipid peroxidation, advanced protein oxidation product, nitric oxide, glutathione, and activity of superoxide dismutase and catalase were estimated on postnatal day 26 to confirm mice model of autism and on postnatal day 56 to assess the effect of astaxanthin. On postnatal day 25, prenatal valproic acid-exposed mice exhibited (i) delayed eye opening (ii) longer latency to respond painful stimuli, (iii) poor sociability and social novelty and (iv) high level of anxiety. In addition, an increased level of oxidative stress was found by determining different oxidative stress markers. Treatment with astaxanthin significantly (p<0.05) improved the behavioral disorder and reduced the oxidative stress in brain and liver. In conclusion, prenatal exposure to valproic day in pregnant mice leads to the development of autism-like features. Astaxanthin improves the impaired behavior in animal model of autism presumably by its antioxidant activity. PMID:25732953

  1. Impact of L-FABP and glucose on polyunsaturated fatty acid induction of PPARα-regulated β-oxidative enzymes.

    PubMed

    Petrescu, Anca D; Huang, Huan; Martin, Gregory G; McIntosh, Avery L; Storey, Stephen M; Landrock, Danilo; Kier, Ann B; Schroeder, Friedhelm

    2013-02-01

    Liver fatty acid binding protein (L-FABP) is the major soluble protein that binds very-long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) in hepatocytes. However, nothing is known about L-FABP's role in n-3 PUFA-mediated peroxisome proliferator activated receptor-α (PPARα) transcription of proteins involved in long-chain fatty acid (LCFA) β-oxidation. This issue was addressed in cultured primary hepatocytes from wild-type, L-FABP-null, and PPARα-null mice with these major findings: 1) PUFA-mediated increase in the expression of PPARα-regulated LCFA β-oxidative enzymes, LCFA/LCFA-CoA binding proteins (L-FABP, ACBP), and PPARα itself was L-FABP dependent; 2) PPARα transcription, robustly potentiated by high glucose but not maltose, a sugar not taken up, correlated with higher protein levels of these LCFA β-oxidative enzymes and with increased LCFA β-oxidation; and 3) high glucose altered the potency of n-3 relative to n-6 PUFA. This was not due to a direct effect of glucose on PPARα transcriptional activity nor indirectly through de novo fatty acid synthesis from glucose. Synergism was also not due to glucose impacting other signaling pathways, since it was observed only in hepatocytes expressing both L-FABP and PPARα. Ablation of L-FABP or PPARα as well as treatment with MK886 (PPARα inhibitor) abolished/reduced PUFA-mediated PPARα transcription of these genes, especially at high glucose. Finally, the PUFA-enhanced L-FABP distribution into nuclei with high glucose augmentation of the L-FABP/PPARα interaction reveals not only the importance of L-FABP for PUFA induction of PPARα target genes in fatty acid β-oxidation but also the significance of a high glucose enhancement effect in diabetes.

  2. Geochemical Niches of Iron-Oxidizing Acidophiles in Acidic Coal Mine Drainage

    PubMed Central

    Kohl, Courtney; Grettenberger, Christen; Larson, Lance N.; Burgos, William D.

    2014-01-01

    A legacy of coal mining in the Appalachians has provided a unique opportunity to study the ecological niches of iron-oxidizing microorganisms. Mine-impacted, anoxic groundwater with high dissolved-metal concentrations emerges at springs and seeps associated with iron oxide mounds and deposits. These deposits are colonized by iron-oxidizing microorganisms that in some cases efficiently remove most of the dissolved iron at low pH, making subsequent treatment of the polluted stream water less expensive. We used full-cycle rRNA methods to describe the composition of sediment communities at two geochemically similar acidic discharges, Upper and Lower Red Eyes in Somerset County, PA, USA. The dominant microorganisms at both discharges were acidophilic Gallionella-like organisms, “Ferrovum” spp., and Acidithiobacillus spp. Archaea and Leptospirillum spp. accounted for less than 2% of cells. The distribution of microorganisms at the two sites could be best explained by a combination of iron(II) concentration and pH. Populations of the Gallionella-like organisms were restricted to locations with pH >3 and iron(II) concentration of >4 mM, while Acidithiobacillus spp. were restricted to pH <3 and iron(II) concentration of <4 mM. Ferrovum spp. were present at low levels in most samples but dominated sediment communities at pH <3 and iron(II) concentration of >4 mM. Our findings offer a predictive framework that could prove useful for describing the distribution of microorganisms in acid mine drainage, based on readily accessible geochemical parameters. PMID:25501473

  3. Parameters affecting the formation of perfluoroalkyl acids during wastewater treatment.

    PubMed

    Guerra, P; Kim, M; Kinsman, L; Ng, T; Alaee, M; Smyth, S A

    2014-05-15

    This study examined the fate and behaviour of perfluoroalkyl acids (PFAAs) in liquid and solid samples from five different wastewater treatment types: facultative and aerated lagoons, chemically assisted primary treatment, secondary aerobic biological treatment, and advanced biological nutrient removal treatment. To the best of our knowledge, this is the largest data set from a single study available in the literature to date for PFAAs monitoring study in wastewater treatment. Perfluorooctanoic acid (PFOA) was the predominant PFAA in wastewater with levels from 2.2 to 150ng/L (influent) and 1.9 to 140ng/L (effluent). Perfluorooctanesulfonic acid (PFOS) was the predominant compound in primary sludge, waste biological sludge, and treated biosolids with concentrations from 6.4 to 2900ng/g dry weight (dw), 9.7 to 8200ng/gdw, and 2.1 to 17,000ng/gdw, respectively. PFAAs were formed during wastewater treatment and it was dependant on both process temperature and treatment type; with higher rates of formation in biological wastewater treatment plants (WWTPs) operating at longer hydraulic retention times and higher temperatures. PFAA removal by sorption was influenced by different sorption tendencies; median log values of the solid-liquid distribution coefficient estimated from wastewater biological sludge and final effluent were: PFOS (3.73)>PFDA (3.68)>PFNA (3.25)>PFOA (2.49)>PFHxA (1.93). Mass balances confirmed the formation of PFAAs, low PFAA removal by sorption, and high PFAA levels in effluents. PMID:24691135

  4. Treatment of hydraulic fracturing wastewater by wet air oxidation.

    PubMed

    Wang, Wei; Yan, Xiuyi; Zhou, Jinghui; Ma, Jiuli

    2016-01-01

    Wastewater produced by hydraulic fracturing for oil and gas production is characterized by high salinity and high chemical oxygen demand (COD). We applied a combination of flocculation and wet air oxidation technology to optimize the reduction of COD in the treatment of hydraulic fracturing wastewater. The experiments used different values of flocculant, coagulant, and oxidizing agent added to the wastewater, as well as different reaction times and treatment temperatures. The use of flocculants for the pretreatment of fracturing wastewater was shown to improve treatment efficiency. The addition of 500 mg/L of polyaluminum chloride (PAC) and 20 mg/L of anionic polyacrylamide (APAM) during pretreatment resulted in a COD removal ratio of 8.2% and reduced the suspended solid concentration of fracturing wastewater to 150 mg/L. For a solution of pretreated fracturing wastewater with 12 mL of added H2O2, the COD was reduced to 104 mg/L when reacted at 300 °C for 75 min, and reduced to 127 mg/L when reacted at the same temperature for 45 min while using a 1 L autoclave. An optimal combination of these parameters produced treated wastewater that met the GB 8978-1996 'Integrated Wastewater Discharge Standard' level I emission standard. PMID:26942530

  5. 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

  6. Unravelling the surface chemistry of metal oxide nanocrystals, the role of acids and bases.

    PubMed

    De Roo, Jonathan; Van den Broeck, Freya; De Keukeleere, Katrien; Martins, José C; Van Driessche, Isabel; Hens, Zeger

    2014-07-01

    We synthesized HfO2 nanocrystals from HfCl4 using a surfactant-free solvothermal process in benzyl alcohol and found that the resulting nanocrystals could be transferred to nonpolar media using a mixture of carboxylic acids and amines. Using solution (1)H NMR, FTIR, and elemental analysis, we studied the details of the transfer reaction and the surface chemistry of the resulting sterically stabilized nanocrystals. As-synthesized nanocrystals are charge-stabilized by protons, with chloride acting as the counterion. Treatment with only carboxylic acids does not lead to any binding of ligands to the HfO2 surface. On the other hand, we find that the addition of amines provides the basic environment in which carboxylic acids can dissociate and replace chloride. This results in stable, aggregate-free dispersions of HfO2 nanocrystals, sterically stabilized by carboxylate ligands. Moreover, titrations with deuterated carboxylic acid show that the charge on the carboxylate ligands is balanced by coadsorbed protons. Hence, opposite from the X-type/nonstoichiometric nanocrystals picture prevailing in literature, one should look at HfO2/carboxylate nanocrystals as systems where carboxylic acids are dissociatively adsorbed to bind to the nanocrystals. Similar results were obtained with ZrO2 NCs. Since proton accommodation on the surface is most likely due to the high Brønsted basicity of oxygen, our model could be a more general picture for the surface chemistry of metal oxide nanocrystals with important consequences on the chemistry of ligand exchange reactions.

  7. Protective effect of rosmarinic acid against oxidative stress biomarkers in liver and kidney of strepotozotocin-induced diabetic rats.

    PubMed

    Mushtaq, Nadia; Schmatz, Roberta; Ahmed, Mushtaq; Pereira, Luciane Belmonte; da Costa, Pauline; Reichert, Karine Paula; Dalenogare, Diéssica; Pelinson, Luana Paula; Vieira, Juliano Marchi; Stefanello, Naiara; de Oliveira, Lizielle Souza; Mulinacci, Nadia; Bellumori, Maria; Morsch, Vera Maria; Schetinger, Maria Rosa

    2015-12-01

    In the present study, we investigated the efficiency of rosmarinic acid (RA) in preventing the alteration of oxidative parameters in the liver and kidney of diabetic rats induced by streptozotocin (STZ). The animals were divided into six groups (n = 8): control, ethanol, RA 10 mg/kg, diabetic, diabetic/ethanol, and diabetic/RA 10 mg/kg. After 3 weeks of treatment, we found that TBARS levels in liver and kidney were significantly increased in the diabetic/saline group and the administration of RA prevented this increase in the liver and kidney (P < 0.05). Diabetes caused a significant decrease in the activity of superoxide dismutase (SOD) and catalase (CAT) in the diabetes/saline group (P < 0.05). However, the treatment with 10 mg/kg RA (antioxidant) prevented this alteration in SOD and CAT activity in the diabetic RA group (P < 0.05). In addition, RA reverses the decrease in ascorbic acid and non-protein-thiol (NPSH) levels in diabetic rats. The treatment with RA also prevented the decrease in the Delta-aminolevulinic acid dehydratase (ALA-D) activity in the liver and kidney of diabetic rats. Furthermore, RA did not have any effect on glycemic levels. These results indicate that RA effectively reduced the oxidative stress induced by STZ, suggesting that RA is a potential candidate for the prevention and treatment of pathological conditions in diabetic models.

  8. Protective effect of rosmarinic acid against oxidative stress biomarkers in liver and kidney of strepotozotocin-induced diabetic rats.

    PubMed

    Mushtaq, Nadia; Schmatz, Roberta; Ahmed, Mushtaq; Pereira, Luciane Belmonte; da Costa, Pauline; Reichert, Karine Paula; Dalenogare, Diéssica; Pelinson, Luana Paula; Vieira, Juliano Marchi; Stefanello, Naiara; de Oliveira, Lizielle Souza; Mulinacci, Nadia; Bellumori, Maria; Morsch, Vera Maria; Schetinger, Maria Rosa

    2015-12-01

    In the present study, we investigated the efficiency of rosmarinic acid (RA) in preventing the alteration of oxidative parameters in the liver and kidney of diabetic rats induced by streptozotocin (STZ). The animals were divided into six groups (n = 8): control, ethanol, RA 10 mg/kg, diabetic, diabetic/ethanol, and diabetic/RA 10 mg/kg. After 3 weeks of treatment, we found that TBARS levels in liver and kidney were significantly increased in the diabetic/saline group and the administration of RA prevented this increase in the liver and kidney (P < 0.05). Diabetes caused a significant decrease in the activity of superoxide dismutase (SOD) and catalase (CAT) in the diabetes/saline group (P < 0.05). However, the treatment with 10 mg/kg RA (antioxidant) prevented this alteration in SOD and CAT activity in the diabetic RA group (P < 0.05). In addition, RA reverses the decrease in ascorbic acid and non-protein-thiol (NPSH) levels in diabetic rats. The treatment with RA also prevented the decrease in the Delta-aminolevulinic acid dehydratase (ALA-D) activity in the liver and kidney of diabetic rats. Furthermore, RA did not have any effect on glycemic levels. These results indicate that RA effectively reduced the oxidative stress induced by STZ, suggesting that RA is a potential candidate for the prevention and treatment of pathological conditions in diabetic models. PMID:26452500

  9. Rapid acid treatment of Escherichia coli: transcriptomic response and recovery

    PubMed Central

    Kannan, Geetha; Wilks, Jessica C; Fitzgerald, Devon M; Jones, Brian D; BonDurant, Sandra S; Slonczewski, Joan L

    2008-01-01

    Background Many E. coli genes show pH-dependent expression during logarithmic growth in acid (pH 5–6) or in base (pH 8–9). The effect of rapid pH change, however, has rarely been tested. Rapid acid treatment could distinguish between genes responding to external pH, and genes responding to cytoplasmic acidification, which occurs transiently following rapid external acidification. It could reveal previously unknown acid-stress genes whose effects are transient, as well as show which acid-stress genes have a delayed response. Results Microarray hybridization was employed to observe the global gene expression of E. coli K-12 W3110 following rapid acidification of the external medium, from pH 7.6 to pH 5.5. Fluorimetric observation of pH-dependent tetR-YFP showed that rapid external acidification led to a half-unit drop in cytoplasmic pH (from pH 7.6 to pH 6.4) which began to recover within 20 s. Following acid treatment, 630 genes were up-regulated and 586 genes were down-regulated. Up-regulated genes included amino-acid decarboxylases (cadA, adiY, gadA), succinate dehydrogenase (sdhABCD), biofilm-associated genes (bdm, gatAB, and ymgABC), and the Gad, Fur and Rcs regulons. Genes with response patterns consistent with cytoplasmic acid stress were revealed by addition of benzoate, a membrane-permeant acid that permanently depresses cytoplasmic pH without affecting external pH. Several genes (yagU, ygiN, yjeI, and yneI) were up-regulated specifically by external acidification, while other genes (fimB, ygaC, yhcN, yhjX, ymgABC, yodA) presented a benzoate response consistent with cytoplasmic pH stress. Other genes (the nuo operon for NADH dehydrogenase I, and the HslUV protease) showed delayed up-regulation by acid, with expression rising by 10 min following the acid shift. Conclusion Transcriptomic profiling of E. coli K-12 distinguished three different classes of change in gene expression following rapid acid treatment: up-regulation with or without recovery, and

  10. Bio-based nitriles from the heterogeneously catalyzed oxidative decarboxylation of amino acids.

    PubMed

    Claes, Laurens; Matthessen, Roman; Rombouts, Ine; Stassen, Ivo; De Baerdemaeker, Trees; Depla, Diederik; Delcour, Jan A; Lagrain, Bert; De Vos, Dirk E

    2015-01-01

    The oxidative decarboxylation of amino acids to nitriles was achieved in aqueous solution by in situ halide oxidation using catalytic amounts of tungstate exchanged on a [Ni,Al] layered double hydroxide (LDH), NH4 Br, and H2 O2 as the terminal oxidant. Both halide oxidation and oxidative decarboxylation were facilitated by proximity effects between the reactants and the LDH catalyst. A wide range of amino acids was converted with high yields, often >90 %. The nitrile selectivity was excellent, and the system is compatible with amide, alcohol, and in particular carboxylic acid, amine, and guanidine functional groups after appropriate neutralization. This heterogeneous catalytic system was applied successfully to convert a protein-rich byproduct from the starch industry into useful bio-based N-containing chemicals.

  11. 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.

  12. 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.

  13. 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.

  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.

  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. Fusaric acid induction of programmed cell death modulated through nitric oxide signalling in tobacco suspension cells.

    PubMed

    Jiao, Jiao; Zhou, Benguo; Zhu, Xiaoping; Gao, Zhengliang; Liang, Yuancun

    2013-10-01

    Fusaric acid (FA) is a nonhost-selective toxin mainly produced by Fusarium oxysporum, the causal agent of plant wilt diseases. We demonstrate that FA can induce programmed cell death (PCD) in tobacco suspension cells and the FA-induced PCD is modulated by nitric oxide (NO) signalling. Cells undergoing cell death induced by FA treatment exhibited typical characteristics of PCD including cytoplasmic shrinkage, chromatin condensation, DNA fragmentation, membrane plasmolysis, and formation of small cytoplasmic vacuoles. In addition, caspase-3-like activity was activated upon the FA treatment. The process of FA-induced PCD was accompanied by a rapid accumulation of NO in a FA dose-dependent manner. Pre-treatment of cells with NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) or NO synthase inhibitor N(G)-monomethyl-arginine monoacetate (L-NMMA) significantly reduced the rate of FA-induced cell death. Furthermore, the caspase-3-like activity and the expression of PAL and Hsr203J genes were alleviated by application of cPTIO or L-NMMA to FA-treated tobacco cells. This indicates that NO is an important factor involved in the FA-induced PCD. Our results also show that pre-treatment of tobacco cells with a caspase-3-specific inhibitor, Ac-DEVD-CHO, can reduce the rate of FA-induced cell death. These results demonstrate that the FA-induced cell death is a PCD and is modulated by NO signalling through caspase-3-like activation. PMID:23838885

  17. The effect of conjugated linoleic acid supplements on oxidative and antioxidative status of dairy cows.

    PubMed

    Hanschke, N; Kankofer, M; Ruda, L; Höltershinken, M; Meyer, U; Frank, J; Dänicke, S; Rehage, J

    2016-10-01

    Dairy cows develop frequently negative energy balance around parturition and in early lactation, resulting in excessive mobilization of body fat and subsequently in increased risk of ketosis and other diseases. Dietary conjugated linoleic acid (CLA) supplements are used in dairy cows mainly for their depressing effect on milk fat content, but are also proposed to have antioxidative properties. As negative energy balance is associated with oxidative stress, which is also assumed to contribute to disease development, the present study was conducted to examine effects of CLA on oxidative and antioxidative status of lactating dairy cows. German Holstein cows (primiparous n=13, multiparous n=32) were divided into 3 dietary treatment groups receiving 100g/d of control fat supplement, containing 87% stearic acid (CON; n=14), 50g/d of control fat supplement and 50g/d of CLA supplement (CLA 50; n=15), or 100g/d of CLA supplement (CLA 100; n=16). The CLA supplement was lipid-encapsulated and contained 12% of trans-10,cis-12 CLA and cis-9,trans-11 CLA each. Supplementation took place between d1 and 182 postpartum; d 182 until 252 postpartum served as a depletion period. Blood was sampled at d -21, 1, 21, 70, 105, 140, 182, 224, and 252 relative to calving. The antioxidative status was determined using the ferric-reducing ability of plasma, α-tocopherol, α-tocopherol-to-cholesterol mass ratio, and retinol. For determination of oxidative status concentrations of hydroperoxides, thiobarbituric acid-reactive substances (TBARS), N'-formylkynurenine, and bityrosine were measured. Mixed models of fixed and random effects with repeated measures were used to evaluate period 1 (d -21 to 140) and 2 (d182-252) separately. Cows showed increased oxidative stress and lipid peroxidation during the periparturient period in terms of increased serum concentrations of hydroperoxides and TBARS, which decreased throughout lactation. During period 1, the supplemented cows had lower TBARS

  18. The effect of conjugated linoleic acid supplements on oxidative and antioxidative status of dairy cows.

    PubMed

    Hanschke, N; Kankofer, M; Ruda, L; Höltershinken, M; Meyer, U; Frank, J; Dänicke, S; Rehage, J

    2016-10-01

    Dairy cows develop frequently negative energy balance around parturition and in early lactation, resulting in excessive mobilization of body fat and subsequently in increased risk of ketosis and other diseases. Dietary conjugated linoleic acid (CLA) supplements are used in dairy cows mainly for their depressing effect on milk fat content, but are also proposed to have antioxidative properties. As negative energy balance is associated with oxidative stress, which is also assumed to contribute to disease development, the present study was conducted to examine effects of CLA on oxidative and antioxidative status of lactating dairy cows. German Holstein cows (primiparous n=13, multiparous n=32) were divided into 3 dietary treatment groups receiving 100g/d of control fat supplement, containing 87% stearic acid (CON; n=14), 50g/d of control fat supplement and 50g/d of CLA supplement (CLA 50; n=15), or 100g/d of CLA supplement (CLA 100; n=16). The CLA supplement was lipid-encapsulated and contained 12% of trans-10,cis-12 CLA and cis-9,trans-11 CLA each. Supplementation took place between d1 and 182 postpartum; d 182 until 252 postpartum served as a depletion period. Blood was sampled at d -21, 1, 21, 70, 105, 140, 182, 224, and 252 relative to calving. The antioxidative status was determined using the ferric-reducing ability of plasma, α-tocopherol, α-tocopherol-to-cholesterol mass ratio, and retinol. For determination of oxidative status concentrations of hydroperoxides, thiobarbituric acid-reactive substances (TBARS), N'-formylkynurenine, and bityrosine were measured. Mixed models of fixed and random effects with repeated measures were used to evaluate period 1 (d -21 to 140) and 2 (d182-252) separately. Cows showed increased oxidative stress and lipid peroxidation during the periparturient period in terms of increased serum concentrations of hydroperoxides and TBARS, which decreased throughout lactation. During period 1, the supplemented cows had lower TBARS

  19. Effect of acid concentration and treatment time on acid-alcohol modified jackfruit seed starch properties.

    PubMed

    Dutta, Himjyoti; Paul, Sanjib Kumar; Kalita, Dipankar; Mahanta, Charu Lata

    2011-09-15

    The properties of starch extracted from jackfruit (Artocarpus heterophyllus Lam.) seeds, collected from west Assam after acid-alcohol modification by short term treatment (ST) for 15-30min with concentrated hydrochloric acid and long term treatment (LT) for 1-15days with 1M hydrochloric acid, were investigated. Granule density, freeze thaw stability, solubility and light transmittance of the treated starches increased. A maximum decrease in the degree of polymerisation occurred in ST of 30min (2607.6). Jackfruit starch had 27.1±0.04% amylose content (db), which in ST initially decreased and then increased with the severity of treatment; in LT the effect was irregular. The pasting profile and granule morphology of the treated samples were severely modified. Native starch had the A-type crystalline pattern and crystalline structure increased on treatment. FTIR spectra revealed slight changes in bond stretching and bending. Colour measurement indicated that whiteness increased on treatment. Acid modified jackfruit seed starch can have applications in the food industry.

  20. Effect of acid concentration and treatment time on acid-alcohol modified jackfruit seed starch properties.

    PubMed

    Dutta, Himjyoti; Paul, Sanjib Kumar; Kalita, Dipankar; Mahanta, Charu Lata

    2011-09-15

    The properties of starch extracted from jackfruit (Artocarpus heterophyllus Lam.) seeds, collected from west Assam after acid-alcohol modification by short term treatment (ST) for 15-30min with concentrated hydrochloric acid and long term treatment (LT) for 1-15days with 1M hydrochloric acid, were investigated. Granule density, freeze thaw stability, solubility and light transmittance of the treated starches increased. A maximum decrease in the degree of polymerisation occurred in ST of 30min (2607.6). Jackfruit starch had 27.1±0.04% amylose content (db), which in ST initially decreased and then increased with the severity of treatment; in LT the effect was irregular. The pasting profile and granule morphology of the treated samples were severely modified. Native starch had the A-type crystalline pattern and crystalline structure increased on treatment. FTIR spectra revealed slight changes in bond stretching and bending. Colour measurement indicated that whiteness increased on treatment. Acid modified jackfruit seed starch can have applications in the food industry. PMID:25212133

  1. Ecosystem-specific selection of microbial ammonia oxidizers in an acid soil

    NASA Astrophysics Data System (ADS)

    Saiful Alam, M.; Ren, G.; Lu, L.; Zheng, Y.; Peng, X.; Jia, Z.

    2013-01-01

    The function of ammonia-oxidizing archaea (AOA) and bacteria (AOB) depends on the availability of ammonia substrate and the supply of oxygen. The interactions and evolutions of AOA and AOB communities along ecological gradients of substrate availability in complex environment have been much debated, but rarely tested. In this study, two ecosystems of maize and rice crops under different fertilization regimes were selected to investigate the community diversification of soil AOA and AOB in response to long-term field fertilization and flooding management in an acid soil. Real-time quantitative PCR of amoA genes demonstrated that the abundance of AOA was significantly stimulated after conversion of upland to paddy soils, while slight decline of AOB populations was observed. DGGE fingerprints of amoA genes further revealed remarkable changes in community compositions of AOA in paddy soil when compared to upland soil. Sequencing analysis revealed that upland soil was dominated by AOA within the soil group 1.1b lineage, while the marine group 1.1a lineage predominated AOA communities in paddy soils. Irrespective of upland and paddy soils, long-term field fertilizations led to higher abundance of amoA genes of AOA and AOB than control treatment that received no fertilization, whereas archaeal amoA gene abundances outnumbered their bacterial counterpart in all samples. Phylogenetic analyses of amoA genes showed that Nitrosospira cluster 3-like AOB dominated bacterial ammonia oxidizers in both paddy and upland soils, regardless of fertilization treatments. The results of this study suggest that the marine group 1.1a AOA could be better adapted to low-oxygen environment than AOA ecotypes of the soil group 1.1b lineage, and implicate that long-term flooding as the dominant selective force driving the community diversification of AOA populations in the acid soil tested.

  2. Use of sulfate reducing bacteria in acid mine drainage treatment

    SciTech Connect

    Powers, T.J.

    1995-10-01

    The environmental impacts caused by Acid Mine Drainage (AMD) were first recorded in 1556 by Georgius Agricola. In the United States 10,000 miles of streams and 29,000 surface acres of impoundments are estimated to be seriously affected by AMD. Abandoned surface mines are estimated to contribute about 15% of the drainage, while active mines (40%) and shaft and drift mines (45%) contribute the remainder. AMD results when metal sulfide minerals, particularly pyrite (FeS{sub 2}), come in contact with oxygen and water. Acid generation occurs when metal sulfide minerals are oxidized according to the Initiator Reaction: FeS{sub 2}(pyrite) + 3 1/2O{sub 2} + H{sub 2}O {yields} Fe{sup 2+} + 2SO{sub 4}{sup 2-} + 2H{sup +}. This reaction is one of many that results in increased metal mobility and increased acidity (lowered pH) of the mine water. The oxidation of ferrous sulfate is accelerated by bacterial action of Thiobacillus ferrooxidans, a naturally occurring bacterium that at pH 3.5 or less, can rapidly accelerate the conversion of dissolved Fe{sup 2+} (ferrous iron) to Fe{sup 3+} (ferric iron), and can act as an oxidant for the oxidation of pyrite. Ferric ions, as well as other metal ions, and the sulfuric acid have a deleterious influence on the biota of streams receiving AMD. The Lilly/Orphan Boy Mine, located in the Elliston Mining District of Powell County, Montana, was selected as the Sulfate Reducing Bacteria (SRB) technology demonstration site. The mine is situated on a patented claim on Deerlodge National Forest Land about 11 miles south of Elliston, Montana. This abandoned mining operation consists of a 250-foot shaft, four horizontal workings, and some stopping. The shaft is flooded with AMD to the 74-foot level and is discharging about 3 gallons per minute (gpm) at a pH of 3.0 from the adit associated with this level.

  3. Anaerobic ammonium oxidation for treatment of ammonium-rich wastewaters*

    PubMed Central

    Zhang, Lei; Zheng, Ping; Tang, Chong-jian; Jin, Ren-cun

    2008-01-01

    The concept of anaerobic ammonium oxidation (ANAMMOX) is presently of great interest. The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists. Meanwhile, the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters. Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite (CANON) have been developed, and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control. Successful full-scale practice in the Netherlands will accelerate application of the process in future. This review introduces the microbiology and more focuses on application of the ANAMMOX process. PMID:18500782

  4. Oxidative Stress to the Cornea, Changes in Corneal Optical Properties, and Advances in Treatment of Corneal Oxidative Injuries

    PubMed Central

    Cejka, Cestmir; Cejkova, Jitka

    2015-01-01

    Oxidative stress is involved in many ocular diseases and injuries. The imbalance between oxidants and antioxidants in favour of oxidants (oxidative stress) leads to the damage and may be highly involved in ocular aging processes. The anterior eye segment and mainly the cornea are directly exposed to noxae of external environment, such as air pollution, radiation, cigarette smoke, vapors or gases from household cleaning products, chemical burns from splashes of industrial chemicals, and danger from potential oxidative damage evoked by them. Oxidative stress may initiate or develop ocular injury resulting in decreased visual acuity or even vision loss. The role of oxidative stress in the pathogenesis of ocular diseases with particular attention to oxidative stress in the cornea and changes in corneal optical properties are discussed. Advances in the treatment of corneal oxidative injuries or diseases are shown. PMID:25861412

  5. Oxidative stress to the cornea, changes in corneal optical properties, and advances in treatment of corneal oxidative injuries.

    PubMed

    Cejka, Cestmir; Cejkova, Jitka

    2015-01-01

    Oxidative stress is involved in many ocular diseases and injuries. The imbalance between oxidants and antioxidants in favour of oxidants (oxidative stress) leads to the damage and may be highly involved in ocular aging processes. The anterior eye segment and mainly the cornea are directly exposed to noxae of external environment, such as air pollution, radiation, cigarette smoke, vapors or gases from household cleaning products, chemical burns from splashes of industrial chemicals, and danger from potential oxidative damage evoked by them. Oxidative stress may initiate or develop ocular injury resulting in decreased visual acuity or even vision loss. The role of oxidative stress in the pathogenesis of ocular diseases with particular attention to oxidative stress in the cornea and changes in corneal optical properties are discussed. Advances in the treatment of corneal oxidative injuries or diseases are shown. PMID:25861412

  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. 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.

  8. Impact of ultrasound treatment on lipid oxidation of Cheddar cheese whey.

    PubMed

    Torkamani, Amir Ehsan; Juliano, Pablo; Ajlouni, Said; Singh, Tanoj Kumar

    2014-05-01

    Ultrasound (US) has been suggested for many whey processing applications. This study examined the effects of ultrasound treatment on the oxidation of lipids in Cheddar cheese whey. Freshly pasteurized whey (0.86 L) was ultrasonicated in a contained environment at the same range of frequencies and energies for 10 and 30 min at 37°C. The US reactor used was characterized by measuring the generation of free radicals in deionized water at different frequencies (20-2000 kHz) and specific energies (8.0-390 kJ/kg). Polar lipid (PL), free and bound fatty acids and lipid oxidation derived compounds were identified and quantified before and after US processing using high performance liquid chromatography equipped with an evaporative light scattering detector (HPLC-ELSD), methylation followed by gas chromatography flame ionized detector (GC-FID) and solid phase micro-extraction gas chromatography mass spectrometry (SPME-GCMS), respectively. The highest concentration of hydroxyl radical formation in the sonicated whey was found between 400 and 1000 kHz. There were no changes in phospholipid composition after US processing at 20, 400, 1000 and 2000 kHz compared to non-sonicated samples. Lipid oxidation volatile compounds were detected in both non-sonicated and sonicated whey. Lipid oxidation was not promoted at any tested frequency or specific energy. Free fatty acid concentration was not affected by US treatment per se. Results revealed that US can be utilized in whey processing applications with no negative impact on whey lipid chemistry. PMID:24360841

  9. Synergistic interaction between oxides of copper and iron for production of fatty alcohols from fatty acids

    DOE PAGES

    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

  10. 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.

  11. 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

  12. Effect of 82% Lactic Acid in Treatment of Melasma

    PubMed Central

    Singh, Rashmi; Goyal, Sapna; Ahmed, Qazi Rais; Gupta, Narendra; Singh, Sujata

    2014-01-01

    Melasma is an acquired, chronic, and symmetrical hypermelanosis, characterized by brown patches of variable darkness on sun exposed areas of body. There are numerous modalities of treatment currently in use for this disease, of which the chemical peeling is very commonly used. Therefore, the present work was done to see the effect of 82% lactic acid peel in the treatment of melasma. A total number of 20 patients of either sex attending the OPD of dermatology department with clinically evident melasma were included in the study. 82% Lactic acid peel was applied on the face for 12 weeks in each patient. Patients were evaluated clinically and photographically at various intervals and in follow-up till 24 weeks. Assessment of patient satisfaction and side effects were also noted. All the subjects completed the study. Application of this peel for 12 weeks significantly decreased the melasma area severity index score and also melasma severity scale score. Patient and physician analogue scales also showed the improvement by the treatment. Regarding the adverse effects, burning sensation was the only side effect noted in our study. In conclusion, 82% lactic acid peel is well tolerated and can be used for the treatment of melasma. PMID:27355080

  13. Prolonged treatment with ursodeoxycholic acid for primary biliary cirrhosis.

    PubMed

    Crippa, G; Cagnoni, C; Castelli, A; Concesi, C; Girometta, S; Pancotti, D; Sverzellati, E; Tacchini, G; Pierfranceschi, M G; Carrara, G C

    1995-05-01

    Eighteen patients affected with biopsy-proved primary biliary cirrhosis (PBC) (histological stage III and IV) received ursodeoxicholic acid (UDCA) 600 mg for 1 year. Signs and symptoms and biochemical tests (glutamic and oxalcetic transaminase, glutamic and pyruvic transaminase, bilirubine, gamma-glutamyl transpeptidase, alkaline phosphatase, leucine aminopeptidase, bile acids, plasma proteins electrophoresis, immunoglubulins A, G and M) and antimitochondrial antibodies were evaluated before the treatment and every four months during the treatment. The results were compared with those obtained in 8 untreated patients affected PBC. The control group of patients were comparable (as far as age, histological stage, biochemical tests are concerned) to the group who received UDCA. Bilirubine, ALP, gamma-GT and LAP decreased during the treatment with UDCA and remained lower than baseline values until the end of the observation (12 months), while no changes occurred in the untreated patients. Both in the treated and untreated group plasma protein electrophoresis, serum immunoglubulins A, G and M remained unchanged, as well as anti-mitochondrial antibody. A moderate reduction of transaminases and bile acids was observed in the group of patients receiving UDCA but it did not reach statistical significance. In 16 out of the 18 treated patients pruritus disappeared and resulted diminished in the remaining 2 patients. No significant amelioration of pruritus was observed in the patients who did not receive UDCA. In conclusion, our data show that prolonged treatment with UDCA drastically reduces pruritus and improves cholestasis biochemical tests in patients affected with symptomatic PBC.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. A dielectric barrier discharge terminally inactivates RNase A by oxidizing sulfur-containing amino acids and breaking structural disulfide bonds

    NASA Astrophysics Data System (ADS)

    Lackmann, J.-W.; Baldus, S.; Steinborn, E.; Edengeiser, E.; Kogelheide, F.; Langklotz, S.; Schneider, S.; Leichert, L. I. O.; Benedikt, J.; Awakowicz, P.; Bandow, J. E.

    2015-12-01

    RNases are among the most stable proteins in nature. They even refold spontaneously after heat inactivation, regaining full activity. Due to their stability and universal presence, they often pose a problem when experimenting with RNA. We investigated the capabilities of nonthermal atmospheric-pressure plasmas to inactivate RNase A and studied the inactivation mechanism on a molecular level. While prolonged heating above 90 °C is required for heat inactivating RNase A, direct plasma treatment with a dielectric barrier discharge (DBD) source caused permanent inactivation within minutes. Circular dichroism spectroscopy showed that DBD-treated RNase A unfolds rapidly. Raman spectroscopy indicated methionine modifications and formation of sulfonic acid. A mass spectrometry-based analysis of the protein modifications that occur during plasma treatment over time revealed that methionine sulfoxide formation coincides with protein inactivation. Chemical reduction of methionine sulfoxides partially restored RNase A activity confirming that sulfoxidation is causal and sufficient for RNase A inactivation. Continued plasma exposure led to over-oxidation of structural disulfide bonds. Using antibodies, disulfide bond over-oxidation was shown to be a general protein inactivation mechanism of the DBD. The antibody’s heavy and light chains linked by disulfide bonds dissociated after plasma exposure. Based on their ability to inactivate proteins by oxidation of sulfur-containing amino acids and over-oxidation of disulfide bonds, DBD devices present a viable option for inactivating undesired or hazardous proteins on heat or solvent-sensitive surfaces.

  15. ACTIVATION OF VASCULAR ENDOTHELIAL NITRIC OXIDE SYNTHASE AND HEME OXYGENASE-1 EXPRESSION BY ELECTROPHILIC NITRO-FATTY ACIDS

    PubMed Central

    Khoo, Nicholas K.H.; Rudolph, Volker; Cole, Marsha P.; Golin-Bisello, Franca; Schopfer, Francisco J.; Woodcock, Steven R.; Batthyany, Carlos; Freeman, Bruce A.

    2010-01-01

    Reactive oxygen species mediate a decrease in nitric oxide (NO) bioavailability and endothelial dysfunction, with secondary oxidized and nitrated byproducts of these reactions contributing to the pathogenesis of numerous vascular diseases. While oxidized lipids and lipoproteins exacerbate inflammatory reactions in the vasculature, in stark contrast the nitration of polyunsaturated fatty acids and complex lipids yield electrophilic products that exhibit pluripotent anti-inflammatory signaling capabilities acting via both cGMP-dependent and -independent mechanisms. Herein we report that nitro-oleic acid (OA-NO2) treatment increases expression of endothelial nitric oxide synthase (eNOS) and heme oxygenase 1 (HO-1) in the vasculature, thus transducing vascular protective effects associated with enhanced NO production. Administration of OA-NO2 via osmotic pump results in a significant increase in eNOS and HO-1 mRNA in mouse aortas. Moreover, HPLC-MS/MS analysis showed that NO2-FAs are rapidly metabolized in cultured endothelial cells (ECs) and treatment with NO2-FAs stimulated the phosphorylation of eNOS at Ser1179. These post-translational modifications of eNOS, in concert with elevated eNOS gene expression, contributed to an increase in endothelial NO production. In aggregate, OA-NO2-induced eNOS and HO-1 expression by vascular cells can induce beneficial effects on endothelial function and provide a new strategy for treating various vascular inflammatory and hypertensive disorders. PMID:19857569

  16. Oxidation of nonplasma fatty acids during exercise is increased in women with abdominal obesity.

    PubMed

    Horowitz, J F; Klein, S

    2000-12-01

    We evaluated plasma fatty acid availability and plasma and whole body fatty acid oxidation during exercise in five lean and five abdominally obese women (body mass index = 21 +/- 1 vs. 38 +/- 1 kg/m(2)), who were matched on aerobic fitness, to test the hypothesis that obesity alters the relative contribution of plasma and nonplasma fatty acids to total energy production during exercise. Subjects exercised on a recumbent cycle ergometer for 90 min at 54% of their peak oxygen consumption. Stable isotope tracer methods ([(13)C]palmitate) were used to measure fatty acid rate of appearance in plasma and the rate of plasma fatty acid oxidation, and indirect calorimetry was used to measure whole body substrate oxidation. During exercise, palmitate rate of appearance increased progressively and was similar in obese and lean groups between 60 and 90 min of exercise [3.9 +/- 0.4 vs. 4.0 +/- 0.3 micromol. kg fat free mass (FFM)(-1). min(-1)]. The rate of plasma fatty acid oxidation was also similar in obese and lean subjects (12.8 +/- 1.7 vs. 14.5 +/- 1.8 micromol. kg FFM(-1). min(-1); P = not significant). However, whole body fatty acid oxidation during exercise was 25% greater in obese than in lean subjects (21.9 +/- 1.2 vs. 17.5 +/- 1.6 micromol. kg FFM(-1). min(-1); P < 0.05). These results demonstrate that, although plasma fatty acid availability and oxidation are similar during exercise in lean and obese women, women with abdominal obesity use more fat as a fuel by oxidizing more nonplasma fatty acids.

  17. 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

  18. Utilization of hydrogen sulfide from acidic gases produced in treatment with amines

    SciTech Connect

    Lunin, A.F.; Hussein, A.H.; Burdeinaya, T.N.

    1994-07-01

    Treatment with amines is the basic method for removing hydrogen sulfide from gases. When such treatment is used, there is a problem in utilizing the acidic regeneration gases, which consist of carbon dioxide, hydrogen sulfide, and C{sub 1}-C{sub 4} hydrocarbons. If the concentration of hydrogen sulfide in these gases is below 20%, it is best removed by direct oxidation by oxygen to form sulfur or sulfur dioxide, over solid or liquid catalysts. Here we are reporting on an investigation of the activity and selectivity of commercial oxide catalysts in this reaction. Commercial catalysts were used in the direct oxidation of gas containing hydrogen sulfide (2-4% hydrogen sulfide, 1-4% C{sub 1}-C{sub 4} hydrocarbons, remainder carbon dioxide) in a laboratory flow unit with a fixed bed of catalyst. The compositions of the feed and the reaction products were determined by gas-liquid chromatography. The oxidation of hydrogen sulfide may proceed with the formation of either sulfur dioxide or sulfur. Catalyst activity was rated on the basis of the total conversion of hydrogen sulfide, the percentage conversions to elemental sulfur and sulfur dioxide, and the selectivity for the formation of elemental sulfur. The catalyst activities were investigated at temperatures of 170-270{degrees}C, space velocity of feed 300 h{sup -1}, hydrogen sulfide concentration 2-4%, and O{sub 2}: H{sub 2}S ratio 1.

  19. Remediation of TCE-contaminated groundwater using acid/BOF slag enhanced chemical oxidation.

    PubMed

    Tsai, T T; Kao, C M; Wang, J Y

    2011-04-01

    The objective of this study was to evaluate the potential of applying acid/H(2)O(2)/basic oxygen furnace slag (BOF slag) and acid/S(2)O(8)(2-)/BOF slag systems to enhance the chemical oxidation of trichloroethylene (TCE)-contaminated groundwater. Results from the bench-scale study indicate that TCE oxidation via the Fenton-like oxidation process can be enhanced with the addition of BOF slag at low pH (pH=2-5.2) and neutral (pH=7.1) conditions. Because the BOF slag has iron abundant properties (14% of FeO and 6% of Fe(2)O(3)), it can be sustainably reused for the supplement of iron minerals during the Fenton-like or persulfate oxidation processes. Results indicate that higher TCE removal efficiency (84%) was obtained with the addition of inorganic acid for the activation of Fenton-like reaction compared with the experiments with organic acids addition (with efficiency of 10-15% lower) (BOF slag=10gL(-1); initial pH=5.2). This could be due to the fact that organic acids would compete with TCE for available oxidants. Results also indicate that the pH value had a linear correlation with the observed first-order decay constant of TCE, and thus, lower pH caused a higher TCE oxidation rate.

  20. Oxidative Radical Addition-Cyclization of Sulfonyl Hydrazones with Simple Olefins by Binary Acid Catalysis.

    PubMed

    Zhong, Xingren; Lv, Jian; Luo, Sanzhong

    2016-07-01

    An unprecedented binary acid accelerated oxidative radical annulation of sulfonyl hydrazones with simple olefins is described. Notably, this method provides a novel oxidative radical cycloaddition for the construction of six-member heterocycles. It offers a rapid and efficient approach to tetrahydropyridazines which are key structural motifs in pharmaceutically active compounds.

  1. 21 CFR 178.3770 - Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyhydric alcohol esters of oxidatively refined... Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids. Polyhydric alcohol... following prescribed conditions: (a) The polyhydric alcohol esters identified in this paragraph may be...

  2. 21 CFR 178.3770 - Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyhydric alcohol esters of oxidatively refined... Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids. Polyhydric alcohol... following prescribed conditions: (a) The polyhydric alcohol esters identified in this paragraph may be...

  3. 21 CFR 178.3770 - Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyhydric alcohol esters of oxidatively refined... Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids. Polyhydric alcohol... following prescribed conditions: (a) The polyhydric alcohol esters identified in this paragraph may be...

  4. 21 CFR 178.3770 - Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyhydric alcohol esters of oxidatively refined... Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids. Polyhydric alcohol... following prescribed conditions: (a) The polyhydric alcohol esters identified in this paragraph may be...

  5. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

  6. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

  7. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

  8. 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

  9. Alpinia protocatechuic acid protects against oxidative damage in vitro and reduces oxidative stress in vivo.

    PubMed

    Shi, Gui-Fang; An, Li-Jia; Jiang, Bo; Guan, Shui; Bao, Yong-Ming

    2006-08-01

    In this study, the neuroprotective effects of Alpinia protocatechuic acid (PCA), a phenolic compound isolated from the dried fruits of Alpinia Oxyphylla Miq. was found. The protective effect of Alpinia PCA against H2O2-induced oxidative damage on PC12 cells was investigated by measuring cell viability via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Rats were injected intraperitoneally with Alpinia PCA at a dose of 5mg/kg per day for 7 days, behavioral testing was performed in Y-maze. In order to make clear the neuroprotective mechanism of Alpinia PCA, the activities of endogenous antioxidants and the content of lipid peroxide in brain were assayed. The results proved that Alpinia PCA significantly prevented the H2O2-induced reduction in cell survival, improved the cognition of aged rats, reduced the content of lipid peroxide, increased the activity of glutathione peroxidase and superoxide dismutase. All these suggested that Alpinia PCA was a potential neuroprotective agent and its neuroprotective effects were achieved at least partly by promoting endogenous antioxidant enzymatic activities and inhibiting free radical generation.

  10. Anchoring Transitions of Liquid Crystals for Optical Amplification of Phospholipid Oxidation Inhibition by Ascorbic Acid.

    PubMed

    Zhang, Minmin; Jang, Chang-Hyun

    2015-01-01

    There is considerable evidence that the antioxidant property of ascorbic acid (AH) is effective for reducing oxidative stress of phospholipids. Herein, a liquid crystals (LCs)-based method was developed for the optical amplification of resistance to phospholipid oxidation by AH. Phospholipid peroxidation initiated by free radicals was monitored from a homeotropic-to-planar anchoring transition of LCs via polarized optical microscopy. Alternatively, consistent homeotropic anchoring of LCs was observed when the oxidation caused by free radicals was blocked by AH.

  11. Oxidative metabolism of 5-o-caffeoylquinic acid (chlorogenic acid), a bioactive natural product, by metalloporphyrin and rat liver mitochondria.

    PubMed

    dos Santos, Michel D; Martins, Patrícia R; dos Santos, Pierre A; Bortocan, Renato; Iamamoto, Y; Lopes, Norberto P

    2005-09-01

    Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimic the various reactions of cytochrome P450 enzymes systems in the oxidation and oxygenation of various drugs and biologically active compounds. This paper reports an HPLC-MS-MS investigation of chlorogenic acid (CGA) oxidation by iodosylbenzene using iron(III) tetraphenylporphyrin chloride as catalyst. The oxidation products have been detected by sequential MS analyses. In addition, CGA was submitted to an in vitro metabolism assay employing isolated rat liver mitochondria. The single oxidized product obtained from mitochondrial metabolism corresponds to the major product formed by the metalloporphyrin-catalyzed reaction. These results indicate that biomimetic oxidation reactions, in addition to in vitro metabolism assays employing isolated organs/organelles, could replace some in vivo metabolism studies, thus minimizing the problems related to the use of a large number of living animals in experimental research.

  12. Myeloperoxidase-derived oxidants modify apolipoprotein A-I and generate dysfunctional high-density lipoproteins: comparison of hypothiocyanous acid (HOSCN) with hypochlorous acid (HOCl).

    PubMed

    Hadfield, Katrina A; Pattison, David I; Brown, Bronwyn E; Hou, Liming; Rye, Kerry-Anne; Davies, Michael J; Hawkins, Clare L

    2013-01-15

    Oxidative modification of HDLs (high-density lipoproteins) by MPO (myeloperoxidase) compromises its anti-atherogenic properties, which may contribute to the development of atherosclerosis. Although it has been established that HOCl (hypochlorous acid) produced by MPO targets apoA-I (apolipoprotein A-I), the major apolipoprotein of HDLs, the role of the other major oxidant generated by MPO, HOSCN (hypothiocyanous acid), in the generation of dysfunctional HDLs has not been examined. In the present study, we characterize the structural and functional modifications of lipid-free apoA-I and rHDL (reconstituted discoidal HDL) containing apoA-I complexed with phospholipid, induced by HOSCN and its decomposition product, OCN- (cyanate). Treatment of apoA-I with HOSCN resulted in the oxidation of tryptophan residues, whereas OCN- induced carbamylation of lysine residues to yield homocitrulline. Tryptophan residues were more readily oxidized on apoA-I contained in rHDLs. Exposure of lipid-free apoA-I to HOSCN and OCN- significantly reduced the extent of cholesterol efflux from cholesterol-loaded macrophages when compared with unmodified apoA-I. In contrast, HOSCN did not affect the anti-inflammatory properties of rHDL. The ability of HOSCN to impair apoA-I-mediated cholesterol efflux may contribute to the development of atherosclerosis, particularly in smokers who have high plasma levels of SCN- (thiocyanate). PMID:23088652

  13. Effect of treatment with the antioxidant alpha-lipoic (thioctic) acid on heart and kidney microvasculature in spontaneously hypertensive rats.

    PubMed

    Tayebati, Seyed Khosrow; Tomassoni, Daniele; Di Cesare Mannelli, Lorenzo; Amenta, Francesco

    2016-01-01

    Endothelial cells represent an important vascular site of signaling and development of damage during ischemia, inflammation and other pathological conditions. Excessive reactive oxygen species production causes pathological activation of endothelium including exposure of cell to adhesion molecules. Intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) are members of the immunoglobulin super-family which are present on the surface of endothelial cells. These molecules represent important markers of endothelial inflammation. The present study was designed to investigate, with immunochemical and immunohistochemical techniques, the effect of treatment with (+/-)-alpha lipoic (thioctic) acid and its enantiomers on heart and kidney endothelium in spontaneously hypertensive rats (SHR). Arterial hypertension is accompanied by an increased oxidative stress status in the heart characterized by thiobarbituric acid reactive substances (TBARS) and nucleic acid oxidation increase. The higher oxidative stress also modifies adhesion molecules expression. In the heart VCAM-1, which was higher than ICAM-1 and PECAM-1, was increased in SHR. ICAM-1, VCAM-1 and PECAM-1 expression was significantly greater in the renal endothelium of SHR. (+/-)-Alpha lipoic acid and (+)-alpha lipoic acid treatment significantly decreased TBARS levels, the nucleic acid oxidation and prevented adhesion molecules expression in cardiac and renal vascular endothelium. These data suggest that endothelial molecules may be used for studying the mechanisms of vascular injury on target organs of hypertension. The effects observed after treatment with (+)-alpha lipoic acid could open new perspectives for countering heart and kidney microvascular injury which represent a common feature in hypertensive end-organs damage.

  14. Effect of treatment with the antioxidant alpha-lipoic (thioctic) acid on heart and kidney microvasculature in spontaneously hypertensive rats.

    PubMed

    Tayebati, Seyed Khosrow; Tomassoni, Daniele; Di Cesare Mannelli, Lorenzo; Amenta, Francesco

    2016-01-01

    Endothelial cells represent an important vascular site of signaling and development of damage during ischemia, inflammation and other pathological conditions. Excessive reactive oxygen species production causes pathological activation of endothelium including exposure of cell to adhesion molecules. Intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) are members of the immunoglobulin super-family which are present on the surface of endothelial cells. These molecules represent important markers of endothelial inflammation. The present study was designed to investigate, with immunochemical and immunohistochemical techniques, the effect of treatment with (+/-)-alpha lipoic (thioctic) acid and its enantiomers on heart and kidney endothelium in spontaneously hypertensive rats (SHR). Arterial hypertension is accompanied by an increased oxidative stress status in the heart characterized by thiobarbituric acid reactive substances (TBARS) and nucleic acid oxidation increase. The higher oxidative stress also modifies adhesion molecules expression. In the heart VCAM-1, which was higher than ICAM-1 and PECAM-1, was increased in SHR. ICAM-1, VCAM-1 and PECAM-1 expression was significantly greater in the renal endothelium of SHR. (+/-)-Alpha lipoic acid and (+)-alpha lipoic acid treatment significantly decreased TBARS levels, the nucleic acid oxidation and prevented adhesion molecules expression in cardiac and renal vascular endothelium. These data suggest that endothelial molecules may be used for studying the mechanisms of vascular injury on target organs of hypertension. The effects observed after treatment with (+)-alpha lipoic acid could open new perspectives for countering heart and kidney microvascular injury which represent a common feature in hypertensive end-organs damage. PMID:26207883

  15. 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.

  16. Oleic acid, hydroxytyrosol and n-3 fatty acids collectively modulate colitis through reduction of oxidative stress and IL-8 synthesis; in vitro and in vivo studies.

    PubMed

    Reddy, K Vijay Kumar; Naidu, K Akhilender

    2016-06-01

    Our recent study has demonstrated that medium chain triglycerides (MCT) and monounsaturated fatty acids potentiate the beneficial effects of fish oil on risk factors of cardiovascular disease. In the present study, we have investigated the influence of MCT or olive oil on the protective and mucosal healing ability of fish oil in ulcerative colitis using cell simulation and animal models. Caco-2 cells grown in medium chain fatty acids enriched medium has exaggerated t-butyl hydroperoxide induced cell damage, GSH depletion, and IL-1β induced IL-8 synthesis, compared to the cells grown in oleic acid & hydroxytyrosol (OT) enriched medium. Further, combined treatment of cells with eicosapentaenoic acid, docosahexaenoic acid, and OT has remarkably attenuated the cell damage, and IL-8 synthesis, compared to individual treatments. To evaluate the effect of these lipid formulations in vivo, adult Wistar rats were fed diet enriched with high amount of medium chain triglycerides (MCT), virgin olive oil, or their combination with fish oil. Colitis was induced in rats using dextran sulfate sodium (DSS) for 7days followed by 10-days of recovery period. Rats of MCT group exhibit severe disease activity, higher levels of inflammatory cytokines in the colon compared to the olive oil group. Furthermore, there was persistent body weight loss, loose stools, higher levels of inflammatory cytokines in the rats of MCT group, even after DSS was withdrawn from drinking water. Conversely, fish oil has remarkably attenuated the DSS induced alterations in both MCT and olive oil diet groups with significantly greater effect in the olive oil group. Thus, MCT increase the susceptibility to colitis through oxidative damage and IL-8 synthesis in intestinal epithelial cells. The beneficial effects of virgin olive oil could be partially attributed to hydroxytyrosol. Combined treatment of hydroxytyrosol, oleic acid and n-3 fatty acids exhibit huge therapeutic benefits in colitis. PMID:27016717

  17. Oleic acid, hydroxytyrosol and n-3 fatty acids collectively modulate colitis through reduction of oxidative stress and IL-8 synthesis; in vitro and in vivo studies.

    PubMed

    Reddy, K Vijay Kumar; Naidu, K Akhilender

    2016-06-01

    Our recent study has demonstrated that medium chain triglycerides (MCT) and monounsaturated fatty acids potentiate the beneficial effects of fish oil on risk factors of cardiovascular disease. In the present study, we have investigated the influence of MCT or olive oil on the protective and mucosal healing ability of fish oil in ulcerative colitis using cell simulation and animal models. Caco-2 cells grown in medium chain fatty acids enriched medium has exaggerated t-butyl hydroperoxide induced cell damage, GSH depletion, and IL-1β induced IL-8 synthesis, compared to the cells grown in oleic acid & hydroxytyrosol (OT) enriched medium. Further, combined treatment of cells with eicosapentaenoic acid, docosahexaenoic acid, and OT has remarkably attenuated the cell damage, and IL-8 synthesis, compared to individual treatments. To evaluate the effect of these lipid formulations in vivo, adult Wistar rats were fed diet enriched with high amount of medium chain triglycerides (MCT), virgin olive oil, or their combination with fish oil. Colitis was induced in rats using dextran sulfate sodium (DSS) for 7days followed by 10-days of recovery period. Rats of MCT group exhibit severe disease activity, higher levels of inflammatory cytokines in the colon compared to the olive oil group. Furthermore, there was persistent body weight loss, loose stools, higher levels of inflammatory cytokines in the rats of MCT group, even after DSS was withdrawn from drinking water. Conversely, fish oil has remarkably attenuated the DSS induced alterations in both MCT and olive oil diet groups with significantly greater effect in the olive oil group. Thus, MCT increase the susceptibility to colitis through oxidative damage and IL-8 synthesis in intestinal epithelial cells. The beneficial effects of virgin olive oil could be partially attributed to hydroxytyrosol. Combined treatment of hydroxytyrosol, oleic acid and n-3 fatty acids exhibit huge therapeutic benefits in colitis.

  18. Acetylsalicylic acid treatment improves differentiation and immunomodulation of SHED.

    PubMed

    Liu, Y; Chen, C; Liu, S; Liu, D; Xu, X; Chen, X; Shi, S

    2015-01-01

    Stem cells from exfoliated deciduous teeth (SHED) possess multipotent differentiation and immunomodulatory properties. They have been used for orofacial bone regeneration and autoimmune disease treatment. In this study, we show that acetylsalicylic acid (ASA) treatment is able to significantly improve SHED-mediated osteogenic differentiation and immunomodulation. Mechanistically, ASA treatment upregulates the telomerase reverse transcriptase (TERT)/Wnt/β-catenin cascade, leading to improvement of SHED-mediated bone regeneration, and also upregulates TERT/FASL signaling, leading to improvement of SHED-mediated T-cell apoptosis and ameliorating disease phenotypes in dextran sodium sulfate-induced colitis mice. These data indicate that ASA treatment is a practical approach to improving SHED-based cell therapy.

  19. [Characteristics of acid red 3R wastewater treatment by ozone microbubbles].

    PubMed

    Zhang, Jing; Du, Ya-Wei; Liu, Xiao-Jing; Zhou, Yu-Wen; Liu, Chun; Yang, Jing-Liang; Zhang, Lei

    2015-02-01

    The application of microbubble technology for ozonation wastewater treatment could enhance ozone mass transfer, improve ozonation performance and increase ozone utilization efficiency. The ozone microbubbles were used to treat synthetic acid red 3R wastewater in the present study, and compared to ozone conventional bubbles. The ozone mass transfer and ozonation characteristics of acid red 3R were investigated when ozone microbubbles and ozone conventional bubbles were applied. The results confirmed the enhanced ozone mass transfer using microbubbles. The ozone mass transfer coefficient using microbubbles was 3.6 times higher than that using conventional bubbles under the same conditions. Simultaneously, the ozone decomposition coefficient using microbubbles was 6.2 times higher than that using conventional bubbles, which would be favorable for *OH generation. The ozonation rate and mineralization efficiency of acid red 3R could be improved significantly using ozone microbubbles. A TOC removal efficiency of 78.0% was achieved using ozone microbubbles, which was about 2 times higher than that using ozone conventional bubbles. The ozone utilization efficiency using microbubbles was much higher that using conventional bubbles during ozonation treatment of acid red 3R. The average ozone utilization efficiencies were 97.8% and 69.3% when microbubbles and conventional bubbles were used, respectively. The oxidative ability of ozone microbubbles could be increased by enhancing *OH generation, and as a result, the oxidative reaction of degradation intermediates was accelerated by ozone microbubbles. Especially, the mineralization ability of small organic acid intermediates using ozone microbubbles was about 1.6 times higher than that using ozone conventional bubbles.

  20. Label-free amino acid detection based on nanocomposites of graphene oxide hybridized with gold nanoparticles.

    PubMed

    Zhang, Qian; Zhang, Diming; Lu, Yanli; Xu, Gang; Yao, Yao; Li, Shuang; Liu, Qingjun

    2016-03-15

    Nanocomposites of graphene oxide and gold nanoparticles (GO/GNPs) were synthesized for label-free detections of amino acids. Interactions between the composites and amino acids were investigated by both naked-eye observation and optical absorption spectroscopy. The GO/GNPs composites displayed apparent color changes and absorption spectra changes in presences of amino acids including glutamate, aspartate, and cysteine. The interaction mechanisms of the composites and amino acids were discussed and explored with sulfhydryl groups and non-α-carboxylic groups on the amino acids. Sensing properties of the composites were tested, while pure gold particles were used as the control. The results suggested that the GO/GNPs composites had better linearity and stability in dose-dependent responses to the amino acids than those of the particles, especially in detections for acidic amino acids. Therefore, the nanocomposites platform can provide a convenient and efficient approach for label-free optical detections of important molecules such as amino acids.

  1. Usnic acid protects LPS-induced acute lung injury in mice through attenuating inflammatory responses and oxidative stress.

    PubMed

    Su, Zu-Qing; Mo, Zhi-Zhun; Liao, Jin-Bin; Feng, Xue-Xuan; Liang, Yong-Zhuo; Zhang, Xie; Liu, Yu-Hong; Chen, Xiao-Ying; Chen, Zhi-Wei; Su, Zi-Ren; Lai, Xiao-Ping

    2014-10-01

    Usnic acid is a dibenzofuran derivative found in several lichen species, which has been shown to possess several activities, including antiviral, antibiotic, antitumoral, antipyretic, analgesic, antioxidative and anti-inflammatory activities. However, there were few reports on the effects of usnic acid on LPS-induced acute lung injury (ALI). The aim of our study was to explore the effect and possible mechanism of usnic acid on LPS-induced lung injury. In the present study, we found that pretreatment with usnic acid significantly improved survival rate, pulmonary edema. In the meantime, protein content and the number of inflammatory cells in bronchoalveolar lavage fluid (BALF) significantly decreased, and the levels of MPO, MDA, and H2O2 in lung tissue were markedly suppressed after treatment with usnic acid. Meanwhile, the activities of SOD and GSH in lung tissue significantly increased after treatment with usnic acid. Additionally, to evaluate the anti-inflammatory activity of usnic acid, the expression of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and anti-inflammatory cytokine IL-10, and chemokines interleukin-8 (IL-8) and macrophage inflammatory protein-2 (MIP-2) in BALF were studied. The results in the present study indicated that usnic acid attenuated the expression of TNF-α, IL-6, IL-8 and MIP-2. Meanwhile, the improved level of IL-10 in BALF was observed. In conclusion, these data showed that the protective effect of usnic acid on LPS-induced ALI in mice might relate to the suppression of excessive inflammatory responses and oxidative stress in lung tissue. Thus, it was suggested that usnic acid might be a potential therapeutic agent for ALI.

  2. Usefulness of retinoic acid in the treatment of melasma.

    PubMed

    Pathak, M A; Fitzpatrick, T B; Kraus, E W

    1986-10-01

    Melasma is a circumscribed brown macular hypermelanosis of the areas of the face and neck that are exposed to light. Clinical trials with various depigmenting formulations containing hydroquinone were conducted to determine the ideal concentration of hydroquinone, retinoic acid, and corticosteroids for the treatment of melasma. The compounds were tested with and without the concomitant use of topical sunscreen preparations. Based on the results of the trials and our earlier clinical experience, we conclude that treatment of melasma should involve the following: avoidance of sun exposure, constant use of broad-spectrum sunscreens, and topical application of a cream or lotion containing 2% hydroquinone and 0.05% to 0.1% retinoic acid (tretinoin). Patients should suspend use of oral contraceptives and other agents that promote skin pigmentation. The monobenzyl ether of hydroquinone should never be used in melasma therapy.

  3. Removal of coagulant aluminum from water treatment residuals by acid.

    PubMed

    Okuda, Tetsuji; Nishijima, Wataru; Sugimoto, Mayo; Saka, Naoyuki; Nakai, Satoshi; Tanabe, Kazuyasu; Ito, Junki; Takenaka, Kenji; Okada, Mitsumasa

    2014-09-01

    Sediment sludge during coagulation and sedimentation in drinking water treatment is called "water treatment residuals (WTR)". Polyaluminum chloride (PAC) is mainly used as a coagulant in Japan. The recycling of WTR has been desired; one method for its reuse is as plowed soil. However, WTR reuse in this way is inhibited by the aluminum from the added PAC, because of its high adsorption capacity for phosphate and other fertilizer components. The removal of such aluminum from WTR would therefore be advantageous for its reuse as plowed soil; this research clarified the effect of acid washing on aluminum removal from WTR and on plant growth in the treated soil. The percentage of aluminum removal from raw WTR by sulphuric acid solution was around 90% at pH 3, the percentage decreasing to 40% in the case of a sun-dried sample. The maximum phosphate adsorption capacity was decreased and the available phosphorus was increased by acid washing, with 90% of aluminum removal. The enhancement of Japanese mustard spinach growth and the increased in plant uptake of phosphates following acid washing were observed.

  4. 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...

  5. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.3700 Fatty acid, ester with styrenated phenol... chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

  6. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.3700 Fatty acid, ester with styrenated phenol... chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

  7. Acid strength of silica-supported oxide catalysts studied by microcalorimetric measurements of pyridine adsorption

    SciTech Connect

    Cardona-Martinez, N.; Dumesic, J.A. )

    1991-02-01

    Microcalorimetric measurements of the differential heat of pyridine adsorption were used to probe the distribution of acid strength on a series of silica-supported oxide catalysts. Depositing oxides of the following cations onto silica increased the acid strength of the catalyst: Ga{sup 3{plus}}, Zn{sup 2{plus}}, Al{sup 3{plus}}, Fe{sup 3{plus}}, Fe{sup 2{plus}}, Mg{sup 2{plus}}, and Sc{sup 3{plus}}. The acid strength distribution curves for the supported oxide samples showed either two or three regions of constant heat of adsorption while silica had an energetically homogeneous surface. The Ga, Al, and Sc samples were found to have both Bronsted and Lewis acidity while the remaining samples showed only Lewis acidity. Incremental adsorption of pyridine indicated that the initial region of highest heat corresponds to strong Lewis acidity while intermediate heats seemed to be due to weaker Lewis acid sites or a combination of Lewis and Bronsted acid sites. The final region of lowest heat was due to H-bonded pyridine on silica. Estimates of the entropies of adsorption were determined, providing information about the mobility of the adsorbed pyridine molecules. The initial differential heat of adsorption increases proportionally to the Sanderson electronegativity of the added oxide.

  8. Hydroxyapatite formation on graphene oxide modified with amino acids: arginine versus glutamic acid.

    PubMed

    Tavafoghi, M; Brodusch, N; Gauvin, R; Cerruti, M

    2016-01-01

    Hydroxyapatite (HA, Ca5(PO4)3OH) is the main inorganic component of hard tissues, such as bone and dentine. HA nucleation involves a set of negatively charged phosphorylated proteins known as non-collagenous proteins (NCPs). These proteins attract Ca(2+) and PO4(3-) ions and increase the local supersaturation to a level required for HA precipitation. Polar and charged amino acids (AAs) are highly expressed in NCPs, and seem to be responsible for the mineralizing effect of NCPs; however, the individual effect of these AAs on HA mineralization is still unclear. In this work, we investigate the effect of a negatively charged (Glu) and positively charged (Arg) AA bound to carboxylated graphene oxide (CGO) on HA mineralization in simulated body fluids (SBF). Our results show that Arg induces HA precipitation faster and in larger amounts than Glu. We attribute this to the higher stability of the complexes formed between Arg and Ca(2+) and PO4(3-) ions, and also to the fact that Arg exposes both carboxyl and amino groups on the surface. These can electrostatically attract both Ca(2+) and PO4(3-) ions, thus increasing local supersaturation more than Glu, which exposes carboxyl groups only.

  9. Activated carbon electrodes: electrochemical oxidation coupled with desalination for wastewater treatment.

    PubMed

    Duan, Feng; Li, Yuping; Cao, Hongbin; Wang, Yi; Crittenden, John C; Zhang, Yi

    2015-04-01

    The wastewater usually contains low-concentration organic pollutants and some inorganic salts after biological treatment. In the present work, the possibility of simultaneous removal of them by combining electrochemical oxidation and electrosorption was investigated. Phenol and sodium chloride were chosen as representative of organic pollutants and inorganic salts and a pair of activated carbon plate electrodes were used as anode and cathode. Some important working conditions such as oxygen concentration, applied potential and temperature were evaluated to reach both efficient phenol removal and desalination. Under optimized 2.0 V of applied potential, 38°C of temperature, and 500 mL min(-1) of oxygen flow, over 90% of phenol, 60% of TOC and 20% of salinity were removed during 300 min of electrolysis time. Phenol was removed by both adsorption and electrochemical oxidation, which may proceed directly or indirectly by chlorine and hypochlorite oxidation. Chlorophenols were detected as degradation intermediates, but they were finally transformed to carboxylic acids. Desalination was possibly attributed to electrosorption of ions in the pores of activated carbon electrodes. The charging/regeneration cycling experiment showed good stability of the electrodes. This provides a new strategy for wastewater treatment and recycling.

  10. Possible nitric oxide modulation in protective effect of FK-506 against 3-nitropropionic acid-induced behavioral, oxidative, neurochemical, and mitochondrial alterations in rat brain.

    PubMed

    Kumar, Puneet; Kalonia, Harikesh; Kumar, Anil

    2010-10-01

    FK-506 is an immunosuppressant being widely used for allograft rejection cases in the present clinical scenario. Recently, the neuroprotective effect of FK-506 has also been reported against a number of neurodegenerative diseases in rodents. This study was designed to explore the possible protective effect of FK-506 and its interaction with nitric-oxide modulators against 3-nitropropionic acid (3-NP)-induced behavioural, biochemical, neurochemical, and mitochondrial alterations in striatum, cortex, and hippocampus regions of the brain. Systemic administration of 3-nitropropionic acid produces Huntington-like symptoms in rats. 3-NP (10 mg/kg) treatment for 14 days impaired locomotor activity, grip strength, and body weight. 3-NP treatment significantly raised malondialdehyde, nitrite concentration, depleted antioxidant enzymes (SOD and catalase), and levels of bioamines (dopamine and norepinephrine) in striatum, cortex, and hippocampus areas of rat brain. Significant alterations in mitochondrial enzyme complexes (I, II, and IV) activities and mitochondrial redox activity have also been altered significantly by 3-NP. Pretreatment with FK-506 (0.5, 1, and 2 mg/kg) significantly reversed these behavioral, biochemical, and cellular alterations. L-arginine treatment with a subeffective dose FK-506 (1 mg/kg) reversed the protective effect of FK-506. However, L-NAME pretreatment with FK-506 (1 mg/kg) potentiated the protective effect of FK-506. The present study shows that FK-506 attenuates 3-NP-induced neurotoxicity and nitric-oxide modulation might be involved in its protective action. PMID:20550427

  11. Monocarboxylic acids from oxidation of acyclic isoprenoid alkanes by Mycobacterium fortuitum

    NASA Technical Reports Server (NTRS)

    Cox, R. E.; Maxwell, J. R.; Myers, R. N.

    1976-01-01

    Mycobacterium fortuitum utilizes certain stereoisomeric mixtures of individual multimethyl branched alkanes as sole carbon source, including 2,6(R), 10(S), 14(RS)-tetramethylhexadecane; 2,6(R), 10(S), 14(RS)-tetramethylheptadecane; 2,6(RS), 10(RS)-trimethyltetradecane, and 2,6(R), 10(S)-trimethylpentadecane. Products of oxidation isolated from the bacterial lipids were acids derived predominantly from oxidation of the isopropyl terminus of each alkane, except in the case of 2,6(RS), 10(RS)-trimethyltetradecane. With the latter, acids from oxidation at either terminus were detected in comparable proportions.

  12. Effect of single amino acid substitution on oxidative modifications of the Parkinson's disease-related protein, DJ-1.

    PubMed

    Madian, Ashraf G; Hindupur, Jagadish; Hulleman, John D; Diaz-Maldonado, Naomi; Mishra, Vartika R; Guigard, Emmanuel; Kay, Cyril M; Rochet, Jean-Christophe; Regnier, Fred E

    2012-02-01

    Mutations in the gene encoding DJ-1 have been identified in patients with familial Parkinson's disease (PD) and are thought to inactivate a neuroprotective function. Oxidation of the sulfhydryl group to a sulfinic acid on cysteine residue C106 of DJ-1 yields the "2O " form, a variant of the protein with enhanced neuroprotective function. We hypothesized that some familial mutations disrupt DJ-1 activity by interfering with conversion of the protein to the 2O form. To address this hypothesis, we developed a novel quantitative mass spectrometry approach to measure relative changes in oxidation at specific sites in mutant DJ-1 as compared with the wild-type protein. Treatment of recombinant wild-type DJ-1 with a 10-fold molar excess of H(2)O(2) resulted in a robust oxidation of C106 to the sulfinic acid, whereas this modification was not detected in a sample of the familial PD mutant M26I exposed to identical conditions. Methionine oxidized isoforms of wild-type DJ-1 were depleted, presumably as a result of misfolding and aggregation, under conditions that normally promote conversion of the protein to the 2O form. These data suggest that the M26I familial substitution and methionine oxidation characteristic of sporadic PD may disrupt DJ-1 function by disfavoring a site-specific modification required for optimal neuroprotective activity. Our findings indicate that a single amino acid substitution can markedly alter a protein's ability to undergo oxidative modification, and they imply that stimulating the conversion of DJ-1 to the 2O form may be therapeutically beneficial in familial or sporadic PD. PMID:22104028

  13. Do fish oil omega-3 fatty acids enhance antioxidant capacity and mitochondrial fatty acid oxidation in human atrial myocardium via PPARγ activation?

    PubMed

    Anderson, Ethan J; Thayne, Kathleen A; Harris, Mitchel; Shaikh, Saame Raza; Darden, Timothy M; Lark, Daniel S; Williams, John Mark; Chitwood, W Randolph; Kypson, Alan P; Rodriguez, Evelio

    2014-09-10

    Abstract Studies in experimental models suggest that n-3 polyunsaturated fatty acids (PUFAs) improve metabolic and anti-inflammatory/antioxidant capacity of the heart, although the mechanisms are unclear and translational evidence is lacking. In this study, patients ingested a moderately high dose of n-3 PUFAs (3.4 g/day eicosapentaenoic (EPA) and doxosahexaenoic acid (DHA) ethyl-esters) for a period of 2-3 weeks before having elective cardiac surgery. Blood was obtained before treatment and at the time of surgery, and myocardial tissue from the right atrium was also dissected during surgery. Blood EPA levels increased and myocardial tissue EPA and DHA levels were significantly higher in n-3 PUFA-treated patients compared with untreated, standard-of-care control patients. Interestingly, n-3 PUFA patients had greater nuclear transactivation of peroxisome proliferator-activated receptor-γ (PPARγ), fatty acid metabolic gene expression, and enhanced mitochondrial respiration supported by palmitoyl-carnitine in the atrial myocardium, despite no difference in mitochondrial content. Myocardial tissue from n-3 PUFA patients also displayed greater expression and activity of key antioxidant/anti-inflammatory enzymes. These findings lead to our hypothesis that PPARγ activation is a mechanism by which fish oil n-3 PUFAs enhance mitochondrial fatty acid oxidation and antioxidant capacity in human atrial myocardium, and that this preoperative therapeutic regimen may be optimal for mitigating oxidative/inflammatory stress associated with cardiac surgery.

  14. Do Fish Oil Omega-3 Fatty Acids Enhance Antioxidant Capacity and Mitochondrial Fatty Acid Oxidation in Human Atrial Myocardium via PPARγ Activation?

    PubMed Central

    Thayne, Kathleen A.; Harris, Mitchel; Shaikh, Saame Raza; Darden, Timothy M.; Lark, Daniel S.; Williams, John Mark; Chitwood, W. Randolph; Kypson, Alan P.; Rodriguez, Evelio

    2014-01-01

    Abstract Studies in experimental models suggest that n-3 polyunsaturated fatty acids (PUFAs) improve metabolic and anti-inflammatory/antioxidant capacity of the heart, although the mechanisms are unclear and translational evidence is lacking. In this study, patients ingested a moderately high dose of n-3 PUFAs (3.4 g/day eicosapentaenoic (EPA) and doxosahexaenoic acid (DHA) ethyl-esters) for a period of 2–3 weeks before having elective cardiac surgery. Blood was obtained before treatment and at the time of surgery, and myocardial tissue from the right atrium was also dissected during surgery. Blood EPA levels increased and myocardial tissue EPA and DHA levels were significantly higher in n-3 PUFA-treated patients compared with untreated, standard-of-care control patients. Interestingly, n-3 PUFA patients had greater nuclear transactivation of peroxisome proliferator-activated receptor-γ (PPARγ), fatty acid metabolic gene expression, and enhanced mitochondrial respiration supported by palmitoyl-carnitine in the atrial myocardium, despite no difference in mitochondrial content. Myocardial tissue from n-3 PUFA patients also displayed greater expression and activity of key antioxidant/anti-inflammatory enzymes. These findings lead to our hypothesis that PPARγ activation is a mechanism by which fish oil n-3 PUFAs enhance mitochondrial fatty acid oxidation and antioxidant capacity in human atrial myocardium, and that this preoperative therapeutic regimen may be optimal for mitigating oxidative/inflammatory stress associated with cardiac surgery. Antioxid. Redox Signal. 21, 1156–1163. PMID:24597798

  15. Cardiac fatty acid oxidation in heart failure associated with obesity and diabetes.

    PubMed

    Fukushima, Arata; Lopaschuk, Gary D

    2016-10-01

    Obesity and diabetes are major public health problems, and are linked to the development of heart failure. Emerging data highlight the importance of alterations in cardiac energy metabolism as a major contributor to cardiac dysfunction related to obesity and diabetes. Increased rates of fatty acid oxidation and decreased rates of glucose utilization are two prominent changes in cardiac energy metabolism that occur in obesity and diabetes. This metabolic profile is probably both a cause and consequence of a prominent cardiac insulin resistance, which is accompanied by a decrease in both cardiac function and efficiency, and by the accumulation of potentially toxic lipid metabolites in the heart that can further exaggerate insulin resistance and cardiac dysfunction. The high cardiac fatty acid oxidation rates seen in obesity and diabetes are attributable to several factors, including: 1) increased fatty acid supply and uptake into the cardiomyocyte, 2) increased transcription of fatty acid metabolic enzymes, 3) decreased allosteric control of mitochondrial fatty acid uptake and fatty acid oxidation, and 4) increased post-translational acetylation control of various fatty acid oxidative enzymes. Emerging evidence suggests that therapeutic approaches aimed at switching the balance of cardiac energy substrate preference from fatty acid oxidation to glucose use can prevent cardiac dysfunction associated with obesity and diabetes. Modulating acetylation control of fatty acid oxidative enzymes is also a potentially attractive strategy, although presently this is limited to precursors of nicotinamide adenine or nonspecific activators of deacetylation such as resveratrol. This review will focus on the metabolic alterations in the heart that occur in obesity and diabetes, as well as on the molecular mechanisms controlling these metabolic changes. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk. PMID:26996746

  16. Cardiac fatty acid oxidation in heart failure associated with obesity and diabetes.

    PubMed

    Fukushima, Arata; Lopaschuk, Gary D

    2016-10-01

    Obesity and diabetes are major public health problems, and are linked to the development of heart failure. Emerging data highlight the importance of alterations in cardiac energy metabolism as a major contributor to cardiac dysfunction related to obesity and diabetes. Increased rates of fatty acid oxidation and decreased rates of glucose utilization are two prominent changes in cardiac energy metabolism that occur in obesity and diabetes. This metabolic profile is probably both a cause and consequence of a prominent cardiac insulin resistance, which is accompanied by a decrease in both cardiac function and efficiency, and by the accumulation of potentially toxic lipid metabolites in the heart that can further exaggerate insulin resistance and cardiac dysfunction. The high cardiac fatty acid oxidation rates seen in obesity and diabetes are attributable to several factors, including: 1) increased fatty acid supply and uptake into the cardiomyocyte, 2) increased transcription of fatty acid metabolic enzymes, 3) decreased allosteric control of mitochondrial fatty acid uptake and fatty acid oxidation, and 4) increased post-translational acetylation control of various fatty acid oxidative enzymes. Emerging evidence suggests that therapeutic approaches aimed at switching the balance of cardiac energy substrate preference from fatty acid oxidation to glucose use can prevent cardiac dysfunction associated with obesity and diabetes. Modulating acetylation control of fatty acid oxidative enzymes is also a potentially attractive strategy, although presently this is limited to precursors of nicotinamide adenine or nonspecific activators of deacetylation such as resveratrol. This review will focus on the metabolic alterations in the heart that occur in obesity and diabetes, as well as on the molecular mechanisms controlling these metabolic changes. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.

  17. Pharmacologic suppression of oxidative damage and dendritic degeneration following kainic acid-induced excitotoxicity in mouse cerebrum.

    PubMed

    Zaja-Milatovic, Snjezana; Gupta, Ramesh C; Aschner, Michael; Montine, Thomas J; Milatovic, Dejan

    2008-07-01

    Intense seizure activity associated with status epilepticus and excitatory amino acid (EAA) imbalance initiates oxidative damage and neuronal injury in CA1 of the ventral hippocampus. We tested the hypothesis that dendritic degeneration of pyramidal neurons in the CA1 hippocampal area resulting from seizure-induced neurotoxicity is modulated by cerebral oxidative damage. Kainic acid (KA, 1 nmol/5 microl) was injected intracerebroventricularly to C57Bl/6 mice. F2-isoprostanes (F2-IsoPs) and F4-neuroprostanes (F4-NeuroPs) were used as surrogate measures of in vivo oxidative stress and biomarkers of lipid peroxidation. Nitric oxide synthase (NOS) activity was quantified by evaluating citrulline level and pyramidal neuron dendrites and spines were evaluated using rapid Golgi stains and a Neurolucida system. KA produced severe seizures in mice immediately after its administration and a significant (p<0.001) increase in F2-IsoPs, F4-NeuroPs and citrulline levels were seen 30 min following treatment. At the same time, hippocampal pyramidal neurons showed significant (p<0.001) reduction in dendritic length and spine density. In contrast, no significant change in neuronal dendrite and spine density or F2-IsoP, F4-NeuroPs and citrulline levels were found in mice pretreated with vitamin E (alpha-tocopherol, 100mg/kg, i.p.) for 3 days, or with N-tert-butyl-alpha-phenylnitrone (PBN, 200mg/kg, i.p.) or ibuprofen (inhibitors of cyclooxygenase, COX, 14 microg/ml of drinking water) for 2 weeks prior to KA treatment. These findings indicate novel interactions among free radical-induced generation of F2-IsoPs and F4-NeuroPs, nitric oxide and dendritic degeneration, closely associate oxidative damage to neuronal membranes with degeneration of the dendritic system, and point to possible interventions to limit severe damage in acute neurological disorders.

  18. Hydrofluoric-nitric-sulphuric-acid surface treatment of tungsten for carbon fibre-reinforced composite hybrids in space applications

    NASA Astrophysics Data System (ADS)

    Kanerva, M.; Johansson, L.-S.; Campbell, J. M.; Revitzer, H.; Sarlin, E.; Brander, T.; Saarela, O.

    2015-02-01

    Hybrid material systems, such as combinations of tungsten foils and carbon fibre-reinforced plastic (CFRP), are replacing metal alloy concepts in spacecraft enclosures. However, a good adhesion between the tungsten oxide scale and the epoxy resin used is required. Here, the effects of a hydrofluoric-nitric-sulphuric-acid (HFNS) treatment on tungsten oxides and subsequent adhesion to CFRP are analysed using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fracture testing. The work shows that HFNS treatment results in decreased oxygen content, over 50% thinner tungsten trioxide (WO3) layer and increased nano-roughness on thin tungsten foils. Fracture testing established a 39% increase in the average critical strain for tungsten-CFRP specimens after HFNS treatment was carried out on tungsten. The effect of the oxide scale modification regarding the critical strain energy release rate was ΔGc≈ 8.4 J/m2.

  19. In-situ treatment of acid mine waters using fluidized bed ash: Field study

    SciTech Connect

    Everett, J.W.; Canty, G.A.

    1999-07-01

    A slurry of mine water and fluidized bed ash (FBA) was injected into an abandoned coal mine in eastern Oklahoma in July 1997. Oil-field technology was used to inject 1.8 Gg (418 tons) of FBA through five wells in 15 hours. Prior to injection the seep water had a pH of 4.4, was net acidic (acidity over 400 mg/L as CaCO{sub 3}), and had relatively high metal concentrations (in mg/L: Fe-200; Mn-7; and Al-6). After injection, during the period of effective treatment, the seep water had a pH above 6.0, less net acidity, and had lower metals concentrations (in mg/L: Fe-120; Mn-5; and Al-{lt}PQL). When the treated seep water exited the mine, the dissolved metals oxidized and hydrolyzed. As the metals precipitated, the alkalinity introduced by the FBA was consumed and the pH dropped. However, the seep water characteristics upon entering the receiving stream were improved, compared to pre-injection. The resulting seep water quality is such that it is more amenable to further treatment by passive treatment methods, such as anoxic limestone drains or wetlands. Alkaline injection is a finite treatment process. Eventually, the added alkalinity is exhausted, at which time the seep returns to pre-injection conditions, necessitating another injection of ash. For the study discussed in this paper, the treatment lasted approximately 15 months. While the amount of alkalinity added to the mine could have potentially treated much more than a year's volume of seep water, it is believed that much of the injected alkalinity was unavailable in backwater areas in the mine. This alkalinity contributed little, if any, to the treatment of water flowing through the mine. Mine hydrology, especially during injection are crucial to treatment longevity.

  20. Preparation of silicate tungsten bronzes on aluminum by plasma electrolytic oxidation process in 12-tungstosilicic acid

    NASA Astrophysics Data System (ADS)

    Petković, M.; Stojadinović, S.; Vasilić, R.; Belča, I.; Nedić, Z.; Kasalica, B.; Mioč, U. B.

    2011-09-01

    The growth of silicate tungsten bronzes on aluminum by plasma electrolytic oxidation in 12-tungstosilicic acid is experimentally investigated and discussed. Real time imaging and optical emission spectroscopy characterization of plasma electrolytic oxidation show that spatial density of microdischarges is the highest in the early stage of the process, while the percentage of oxide coating area covered by active discharge sites decreases slowly with time. Emission spectrum of microdischarges has several intensive band peaks originating either from aluminum electrode or from the electrolyte. Surface roughness of obtained oxide coatings increases with prolonged time of plasma electrolytic oxidation, as their microhardness decreases. Raman spectroscopy and energy dispersive X-ray spectroscopy are employed to confirm that the outer layer of oxide coatings formed during the plasma electrolytic oxidation process is silicate tungsten bronze

  1. Silver-catalyzed arylation of (hetero)arenes by oxidative decarboxylation of aromatic carboxylic acids.

    PubMed

    Kan, Jian; Huang, Shijun; Lin, Jin; Zhang, Min; Su, Weiping

    2015-02-01

    A long-standing challenge in Minisci reactions is achieving the arylation of heteroarenes by oxidative decarboxylation of aromatic carboxylic acids. To address this challenge, the silver-catalyzed intermolecular Minisci reaction of aromatic carboxylic acids was developed. With an inexpensive silver salt as a catalyst, this new reaction enables a variety of aromatic carboxylic acids to undergo decarboxylative coupling with electron-deficient arenes or heteroarenes regardless of the position of the substituents on the aromatic carboxylic acid, thus eliminating the need for ortho-substituted aromatic carboxylic acids, which were a limitation of previously reported methods.

  2. Ferrous iron oxidation by molecular oxygen under acidic conditions: The effect of citrate, EDTA and fulvic acid

    NASA Astrophysics Data System (ADS)

    Jones, Adele M.; Griffin, Philippa J.; Waite, T. David

    2015-07-01

    In this study, the rates of Fe(II) oxidation by molecular oxygen in the presence of citrate, ethylenediaminetetraacetic acid (EDTA) and Suwannee River fulvic acid (SRFA) were determined over the pH range 4.0-5.5 and, for all of the ligands investigated, found to be substantially faster than oxidation rates in the absence of any ligand. EDTA was found to be particularly effective in enhancing the rate of Fe(II) oxidation when sufficient EDTA was available to complex all Fe(II) present in solution, with a kinetic model of the process found to adequately describe all results obtained. When Fe(II) was only partially complexed by EDTA, reactions with reactive oxygen species (ROS) and heterogeneous Fe(II) oxidation were found to contribute significantly to the removal rate of iron from solution at different stages of oxidation. This was possible due to the rapid rate at which EDTA enhanced Fe(II) oxidation and formed ROS and Fe(III). The rapid rate of Fe(III) generation facilitated the formation of free ferric ion activities in excess of those required for ferric oxyhydroxide precipitation following Fe(III)-EDTA dissociation. In comparison, the rate of Fe(II) oxidation was slower in the presence of citrate, and therefore the concentrations of free Fe(III) able to form in the initial stages of Fe(II) oxidation were much lower than those formed in the presence of EDTA, despite the resultant Fe(III)-citrate complex being less stable than that of Fe(III)-EDTA. The slower rate of citrate enhanced oxidation also resulted in slower rates of ROS generation, and, as such, oxidation of the remaining inorganic Fe(II) species by ROS was negligible. Overall, this study demonstrates that organic ligands may substantially enhance the rate of Fe(II) oxidation. Even under circumstances where the ligand is not present at sufficient concentrations to complex all of the Fe(II) in solution, ensuing oxidative processes may sustain an enhanced rate of Fe(II) oxidation relative to that of

  3. 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

  4. Effects of Fe oxide on N transformations in subtropical acid soils

    NASA Astrophysics Data System (ADS)

    Jiang, Xianjun; Xin, Xiaoping; Li, Shiwei; Zhou, Junchao; Zhu, Tongbin; Müller, Christopher; Cai, Zucong; Wright, Alan L.

    2015-02-01

    Subtropical ecosystems are often characterized by high N cycling rates, but net nitrification rates are often low in subtropical acid soils. NO3--N immobilization into organic N may be a contributing factor to understand the observed low net nitrification rates in these acid soils. The effects of Fe oxide and organic matter on soil N transformations were evaluated using a 15N tracing study. Soil net nitrification was low for highly acidic yellow soil (Ferralsols), but gross ammonia oxidation was 7 times higher than net nitrification. In weakly acidic purple soil (Cambisols), net nitrification was 8 times higher than in Ferralsols. The addition of 5% Fe oxide to Cambisols, reduced the net nitrification rate to a negative rate, while NO3--N immobilization rate increased 8 fold. NO3--N immobilization was also observed in Ferralsols which contained high Fe oxides levels. A possible mechanism for these reactions could be stimulation of NO3--N immobilization by Fe oxide which promoted the abiotic formation of nitrogenous polymers, suggesting that the absence of net nitrification in some highly acid soils may be due to high rates of NO3--N immobilization caused by high Fe oxide content rather than a low pH.

  5. Effects of Fe oxide on N transformations in subtropical acid soils

    PubMed Central

    Jiang, Xianjun; Xin, Xiaoping; Li, Shiwei; Zhou, Junchao; Zhu, Tongbin; Müller, Christopher; Cai, Zucong; Wright, Alan L.

    2015-01-01

    Subtropical ecosystems are often characterized by high N cycling rates, but net nitrification rates are often low in subtropical acid soils. NO3−-N immobilization into organic N may be a contributing factor to understand the observed low net nitrification rates in these acid soils. The effects of Fe oxide and organic matter on soil N transformations were evaluated using a 15N tracing study. Soil net nitrification was low for highly acidic yellow soil (Ferralsols), but gross ammonia oxidation was 7 times higher than net nitrification. In weakly acidic purple soil (Cambisols), net nitrification was 8 times higher than in Ferralsols. The addition of 5% Fe oxide to Cambisols, reduced the net nitrification rate to a negative rate, while NO3−-N immobilization rate increased 8 fold. NO3−-N immobilization was also observed in Ferralsols which contained high Fe oxides levels. A possible mechanism for these reactions could be stimulation of NO3−-N immobilization by Fe oxide which promoted the abiotic formation of nitrogenous polymers, suggesting that the absence of net nitrification in some highly acid soils may be due to high rates of NO3−-N immobilization caused by high Fe oxide content rather than a low pH. PMID:25722059

  6. Suberoylanilide hydroxamic acid radiosensitizes tumor hypoxic cells in vitro through the oxidation of nitroxyl to nitric oxide.

    PubMed

    Samuni, Yuval; Wink, David A; Krishna, Murali C; Mitchell, James B; Goldstein, Sara

    2014-08-01

    The pharmacological effects of hydroxamic acids are partially attributed to their ability to serve as HNO and/or NO donors under oxidative stress. Previously, it was concluded that oxidation of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) by the metmyoglobin/H2O2 reaction system releases NO, which was based on spin trapping of NO and accumulation of nitrite. Reinvestigation of this system demonstrates the accumulation of N2O, which is a marker of HNO formation, at similar rates under normoxia and anoxia. In addition, the yields of nitrite that accumulated in the absence and the presence of O2 did not differ, implying that the source of nitrite is other than autoxidation of NO. In this system metmyoglobin is instantaneously and continuously converted into compound II, leading to one-electron oxidation of SAHA to its respective transient nitroxide radical. Studies using pulse radiolysis show that one-electron oxidation of SAHA (pKa=9.56 ± 0.04) yields the respective nitroxide radical (pKa=9.1 ± 0.2), which under all experimental conditions decomposes bimolecularly to yield HNO. The proposed mechanism suggests that compound I oxidizes SAHA to the respective nitroxide radical, which decomposes bimolecularly in competition with its oxidation by compound II to form HNO. Compound II also oxidizes HNO to NO and NO to nitrite. Given that NO, but not HNO, is an efficient hypoxic cell radiosensitizer, we hypothesized that under an oxidizing environment SAHA might act as a NO donor and radiosensitize hypoxic cells. Preincubation of A549 and HT29 cells with 2.5 μM SAHA for 24h resulted in a sensitizer enhancement ratio at 0.01 survival levels (SER0.01) of 1.33 and 1.59, respectively. Preincubation of A549 cells with oxidized SAHA had hardly any effect and, with 2mM valproic acid, which lacks the hydroxamate group, resulted in SER0.01=1.17. Preincubation of HT29 cells with SAHA and Tempol, which readily oxidizes HNO to NO, enhanced the

  7. Micromechanical properties of intercalated compounds of graphite oxide with dodecahydro- closо-dodecaboric acid

    NASA Astrophysics Data System (ADS)

    Karpenko, A. A.; Saldin, V. I.

    2016-08-01

    The micromechanical properties (Young's modulus, deformation, and adhesion) of the intercalated compound of graphite oxide with dodecahydro- closo-dodecaboric acid were studied by atomic force microscopy, transmission electron microscopy, and Raman spectroscopy and compared with the same characteristics of the starting graphite oxide. The significant difference in the micromechanical properties of the materials under study is dictated by differences in the topography and properties of their film surface, which, in turn, can be determined by their chemical composition. The introduction of dodecahydro- closo-dodecaboric acid in the interplanar space of graphite oxide affects the structuring of the latter. A considerable increase in the adhesion of the intercalated compound relative to that of oxide graphite is explained by high adhesive properties of the introduced acid, the Young's modulus of graphite oxide being higher than that of the intercalated compound. This was attributed to the high hydrophilicity of dodecahydro- closo-dodecaboric acid and the difficulty of water removal from the interplanar space; water plasticizes the material, which becomes softer than graphite oxide. The difference in the structure of the coating of the intercalated compounds and the starting graphite oxide was found to be also reflected by their Raman spectra, namely, by the increased intensity of the D line with the preserved position of the G line, which points to the impurity nature of the intercalate and the unchanged hexagonal lattice of graphite.

  8. Micromechanical properties of intercalated compounds of graphite oxide with dodecahydro- closo-dodecaboric acid

    NASA Astrophysics Data System (ADS)

    Karpenko, A. A.; Saldin, V. I.

    2016-08-01

    The micromechanical properties (Young's modulus, deformation, and adhesion) of the intercalated compound of graphite oxide with dodecahydro- closo-dodecaboric acid were studied by atomic force microscopy, transmission electron microscopy, and Raman spectroscopy and compared with the same characteristics of the starting graphite oxide. The significant difference in the micromechanical properties of the materials under study is dictated by differences in the topography and properties of their film surface, which, in turn, can be determined by their chemical composition. The introduction of dodecahydro- closo-dodecaboric acid in the interplanar space of graphite oxide affects the structuring of the latter. A considerable increase in the adhesion of the intercalated compound relative to that of oxide graphite is explained by high adhesive properties of the introduced acid, the Young's modulus of graphite oxide being higher than that of the intercalated compound. This was attributed to the high hydrophilicity of dodecahydro- closo-dodecaboric acid and the difficulty of water removal from the interplanar space; water plasticizes the material, which becomes softer than graphite oxide. The difference in the structure of the coating of the intercalated compounds and the starting graphite oxide was found to be also reflected by their Raman spectra, namely, by the increased intensity of the D line with the preserved position of the G line, which points to the impurity nature of the intercalate and the unchanged hexagonal lattice of graphite.

  9. Copper-catalyzed tandem phosphination-decarboxylation-oxidation of alkynyl acids with H-phosphine oxides: a facile synthesis of β-ketophosphine oxides.

    PubMed

    Zhang, Pengbo; Zhang, Liangliang; Gao, Yuzhen; Xu, Jian; Fang, Hua; Tang, Guo; Zhao, Yufen

    2015-05-01

    The general method for the tandem phosphination-decarboxylation-oxidation of alkynyl acids under aerobic conditions has been developed. In the presence of CuSO4·5H2O and TBHP, the reactions provide a novel access to β-ketophosphine oxides in good to excellent yields. This transformation allows the direct formation of a P-C bond and the construction of a keto group in one reaction.

  10. Potential for in situ chemical oxidation of acid extractable organics in oil sands process affected groundwater.

    PubMed

    Sohrabi, V; Ross, M S; Martin, J W; Barker, J F

    2013-11-01

    The process of bitumen extraction from oil sands in Alberta, Canada leads to an accumulation of toxic acid-extractable organics (AEOs) in oil sands process water (OSPW). Infiltration of OSPW from tailings ponds and from their retaining sand dykes and subsequent transport towards surface water has occurred. Given the apparent lack of significant natural attenuation of AEOs in groundwater, remediation may be required. This laboratory study evaluates the potential use of unactivated persulfate and permanganate as in situ oxidation agents for remediation of AEOs in groundwater. Naphthenic acids (NAs; CnH2n+zO2), which are a component of the acutely toxic AEOs, were degraded by both oxidants in OSPW samples. Permanganate oxidation yielded some residual dissolved organic carbon (DOC) whereas persulfate mineralized the AEO compounds with less residual DOC. Acid-extractable organics from oxidized OSPW had essentially no Microtox toxicity.

  11. Streptozotocin induced activation of oxidative stress responsive splenic cell signaling pathways: Protective role of arjunolic acid

    SciTech Connect

    Manna, Prasenjit; Ghosh, Jyotirmoy; Das, Joydeep

    2010-04-15

    Present study investigates the beneficial role of arjunolic acid (AA) against the alteration in the cytokine levels and simultaneous activation of oxidative stress responsive signaling pathways in spleen under hyperglycemic condition. Diabetes was induced by injection of streptozotocin (STZ) (at a dose of 70 mg/kg body weight, injected in the tail vain). STZ administration elevated the levels of IL-2 as well as IFN-gamma and attenuated the level of TNF-alpha in the sera of diabetic animals. In addition, hyperglycemia is also associated with the increased production of intracellular reactive intermediates resulting with the elevation in lipid peroxidation, protein carbonylation and reduction in intracellular antioxidant defense. Investigating the oxidative stress responsive cell signaling pathways, increased expressions (immunoreactive concentrations) of phosphorylated p65 as well as its inhibitor protein phospho IkappaBalpha and phosphorylated mitogen activated protein kinases (MAPKs) have been observed in diabetic spleen tissue. Studies on isolated splenocytes revealed that hyperglycemia caused disruption of mitochondrial membrane potential, elevation in the concentration of cytosolic cytochrome c as well as activation of caspase 3 leading to apoptotic cell death. Histological examination revealed that diabetic induction depleted the white pulp scoring which is in agreement with the reduced immunological response. Treatment with AA prevented the hyperglycemia and its associated pathogenesis in spleen tissue. Results suggest that AA might act as an anti-diabetic and immunomodulatory agent against hyperglycemia.

  12. On the role of catalase in the oxidation of tissue fatty acids

    SciTech Connect

    Crane, D.; Masters, C.

    1984-02-15

    The role of catalase in lipid metabolism has been studied by means of a comparison of the turnover characteristics of the major lipid classes in the normal mouse with those of animals in which the catalase activity had been inhibited and blocked by aminotriazole and allylisopropylacetamide. Double isotope ratios were determined in the lipid fractions of several tissues following the injection of labeled glycerol, and a number of significant differences were identified between these treatments. Since catalase is recognized as an integral component of the peroxisomal pathway of fatty acid oxidation, these results may be taken as indicating that interruption of the process of peroxisomal beta-oxidation in this manner cause extensive perturbations of lipid metabolism in the living animal, and these perturbations extend well beyond those tissues where the predominant localization of these organelles occurs. The concept which derives from these data--that of a significant regulatory role of peroxisomes in relation to the overall balance of lipid metabolism in the animal body--is described and discussed.

  13. Photo-oxidation of gaseous ethanol on photocatalyst prepared by acid leaching of titanium oxide/hydroxyapatite composite

    SciTech Connect

    Ono, Y.; Rachi, T.; Yokouchi, M.; Kamimoto, Y.; Nakajima, A.; Okada, K.

    2013-06-01

    Highlights: ► Photocatalyst powder was prepared by acid leaching of TiO{sub 2}/apatite composite. ► The photocatalytic activity was evaluated from in situ FT-IR study using ethanol. ► Apatite in the composite had positive effect for the photo-oxidation of ethanol. ► The enhanced oxidation rate was explained by the difference in deactivation rate. - Abstract: Highly active photocatalysts were synthesized by leaching of heat-treated titanium dioxide (TiO{sub 2})/hydroxyapatite (HAp) powder with hydrochloric acid at 0.25, 0.50, 0.75 mol/l, and their photocatalytic activities were evaluated from in situ Fourier transform infrared (FT-IR) study of photo-oxidation of gaseous ethanol. By changing the acid concentration, the TiO{sub 2}/HAp composite had different atomic ratios of Ca/Ti (0.0–2.8) and P/Ti (0.3–2.1). It was found that phosphate group remained on the surface of TiO{sub 2} particle even in the sample treated with concentrated acid (0.75 mol/l). These acid-treated samples showed higher rates for ethanol photo-oxidation than the commercial TiO{sub 2} powder, Degussa P25. The highest rate was obtained in the TiO{sub 2}/HAp composite treated with the dilute (0.25 mol/l) acid in spite of its low content of TiO{sub 2} photocatalyst. This enhanced photocatalytic activity was attributed to the result that the deactivation with repeated injections of ethanol gas was suppressed in the TiO{sub 2}/HAp composites compared with the TiO{sub 2} powders.

  14. From thiol to sulfonic acid: modeling the oxidation pathway of protein thiols by hydrogen peroxide.

    PubMed

    van Bergen, Laura A H; Roos, Goedele; De Proft, Frank

    2014-08-01

    Hydrogen peroxide is a natural oxidant that can oxidize protein thiols (RSH) via sulfenic acid (RSOH) and sulfinic acid (RSO2H) to sulfonic acid (RSO3H). In this paper, we study the complete anionic and neutral oxidation pathway from thiol to sulfonic acid. Reaction barriers and reaction free energies for all three oxidation steps are computed, both for the isolated substrates and for the substrates in the presence of different model ligands (CH4, H2O, NH3) mimicking the enzymatic environment. We found for all three barriers that the anionic thiolate is more reactive than the neutral thiol. However, the assistance of the environment in the neutral pathway in a solvent-assisted proton-exchange (SAPE) mechanism can lower the reaction barrier noticeably. Polar ligands can decrease the reaction barriers, whereas apolar ligands do not influence the barrier heights. The same holds for the reaction energies: they decrease (become more negative) in the presence of polar ligands whereas apolar ligands do not have an influence. The consistently negative consecutive reaction energies for the oxidation in the anionic pathway when going from thiolate over sulfenic and sulfinic acid to sulfonic acid are in agreement with biological reversibility.

  15. Inhibitory effects of indole α-lipoic acid derivatives on nitric oxide production in LPS/IFNγ activated RAW 264.7 macrophages.

    PubMed

    Karabay, Arzu Zeynep; Koc, Aslı; Gurkan-Alp, A Selen; Buyukbingol, Zeliha; Buyukbingol, Erdem

    2015-04-01

    Alpha-lipoic acid (α-lipoic acid) is a potent antioxidant compound that has been shown to possess anti-inflammatory effects. RAW 264.7 macrophages produce various inflammatory mediators such as nitric oxide, IL-1β, IL-6 and TNF-alpha upon activation with LPS (Lipopolysaccharide) and IFNγ (interferon gamma). In this study, the effect of 12 synthetic indole α-lipoic acid derivatives on nitric oxide production and iNOS (inducible nitric oxide synthase) protein expression in LPS/IFNγ activated RAW 264.7 macrophages was determined. Cell proliferation, nitric oxide levels and iNOS protein expression were examined with thiazolyl blue tetrazolium blue test, griess assay and western blot, respectively. Our results showed that all of the indole α-lipoic acid derivatives showed significant inhibitory effects on nitric oxide production and iNOS protein levels (p < 0.05). The most active compounds were identified as compound I-4b, I-4e and II-3b. In conclusion, these indole α-lipoic acid derivatives may have the potential for treatment of inflammatory conditions related with high nitric oxide production.

  16. Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules.

    PubMed

    Schobesberger, Siegfried; Junninen, Heikki; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

    2013-10-22

    Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molecules and then form growing clusters of one to three sulfuric acid molecules plus one to four oxidized organics. Most of these organic compounds retain 10 carbon atoms, and some of them are remarkably highly oxidized (oxygen-to-carbon ratios up to 1.2). The average degree of oxygenation of the organic compounds decreases while the clusters are growing. Our measurements therefore connect oxidized organics directly, and in detail, with the very first steps of new particle formation and their growth between 1 and 2 nm in a controlled environment. Thus, they confirm that oxidized organics are involved in both the formation and growth of particles under ambient conditions.

  17. Empirical Modeling of Iron Oxide Dissolution in Sulphuric and Hydrochloric Acid

    NASA Astrophysics Data System (ADS)

    Hemmelmann, Jan C.; Xu, Hao; Krumm, Wolfgang

    2013-10-01

    A new approach is presented to an empirical modeling of chemical pickling processes, based on the activation energy of oxide dissolution in hydrochloric acid (HCl) and sulfuric acid (H2SO4). The model allows us to calculate pickling times as a function of definite parameters. The main oxide layers on hot-rolled materials are magnetite (Fe3O4), hematite (Fe2O3), and wustite (FeO). On the laboratory scale, the activation energy of each oxide has been determined. FeO is a metastable oxide and has been produced based on magnetite powder in a H2/H2O atmosphere. The oxide powders used for the experimental procedure have been analyzed by X-ray powder diffraction to insure the proper stoichiometry and composition. The model allows us to calculate the time of oxide dissolution based on the parameters temperature, acid concentration, and the composition of the oxide layer. Calculated values are verified by surface potential measurement on industrial oxide layers. The hot-rolled material used for verification is low carbon steel. A comparison between calculated pickling times and experimental data will be presented.

  18. The enzymic oxidation of chlorogenic acid and some reactions of the quinone produced

    PubMed Central

    Pierpoint, W. S.

    1966-01-01

    1. Partially purified preparations of tobacco-leaf o-diphenol oxidase (o-quinol–oxygen oxidoreductase; EC 1.10.3.1) oxidize chlorogenic acid to brown products, absorbing, on average, 1·6atoms of oxygen/mol. oxidized, and evolving a little carbon dioxide. 2. The effect of benzenesulphinic acid on the oxidation suggests that the first stage is the formation of a quinone; the solution does not go brown, oxygen uptake is restricted to 1 atom/mol. oxidized, and a compound is produced whose composition corresponds to that of a sulphone of the quinone derived from chlorogenic acid. 3. Several other compounds that react with quinones affect the oxidation of chlorogenic acid. The colour of the products formed and the oxygen absorbed in their formation suggest that the quinone formed in the oxidation reacts with these compounds in the same way as do simpler quinones. 4. Some compounds that are often used to prevent the oxidation of polyphenols were tested to see if they act by inhibiting o-diphenol oxidase, by reacting with quinone intermediates, or both. 5. Ascorbate inhibits the enzyme and also reduces the quinone. 6. Potassium ethyl xanthate, diethyldithiocarbamate and cysteine inhibit the enzyme to different extents, and also react with the quinone. The nature of the reaction depends on the relative concentrations of inhibitor and chlorogenic acid. Excess of inhibitor prevents the solution from turning brown and restricts oxygen uptake to 1 atom/mol. of chlorogenic acid oxidized; smaller amounts do not prevent browning and slightly increase oxygen uptake. 7. 2-Mercaptobenzothiazole inhibits the enzyme, and also probably reacts with the quinone; inhibited enzyme is reactivated as if the inhibitor is removed as traces of quinone are produced. 8. Thioglycollate and polyvinylpyrrolidone inhibit the enzyme. Thioglycollate probably reduces the quinone to a small extent. PMID:5941350

  19. [Oregano essential oil as an inhibitor of higher fatty acid oxidation].

    PubMed

    Terenina, M B; Misharina, T A; Krikunova, N I; Alinkina, E S; Fatkulina, L D; Vorob'eva, A K

    2011-01-01

    Inhibition of the oxidation of fatty acids methyl esters by oregano essential oil was studied using capillary gas chromatography. A mixture of fatty acids which contained saturated, mono-, di-, and polyunsaturated acids with 16-24 carbon atoms was extracted from mice brain. Changes in the composition of esters in hexane solutions both in the presence of oregano essential oil and without it were examined during their autooxidation in light for 1 year. It was found that the oxidation rate of unsaturated fatty acids increases with increasing degree of their unsaturation. Oregano essential oil inhibited the oxidation process. Antioxidant activity of the oil increased with increase of its concentration. It was shown that carvacrol and thymol are the main antioxidant components of oregano oil. PMID:21950127

  20. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    PubMed

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters.

  1. Oxidation and hydrolysis of lactic acid in near-critical water

    SciTech Connect

    Li, L.; Vallejo, D.; Gloyna, E.F.; Portela, J.R.

    1999-07-01

    Hydrothermal reactions (oxidation and hydrolysis) involving lactic acid (LA) were studied at temperatures ranging from 300 to 400 C and a nominal pressure of 27.6 MPa. Kinetic models were developed with respect to concentrations of LA and total organic carbon (TOC), respectively. On the basis of identified liquid and gaseous products, pathways for hydrothermal reactions involving lactic acid were proposed. Acetic acid and acetaldehyde were confirmed as the major liquid intermediates for oxidation and hydrolysis reactions, respectively. Carbon monoxide and methane were identified as the major gaseous byproducts from these reactions. These results demonstrate the potential of completely oxidizing, as well as converting, lactic acid into other organic products, in high-temperature water.

  2. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    PubMed

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters. PMID:26506263

  3. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  4. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  5. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  6. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  7. 40 CFR 60.52b - Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... metals, acid gases, organics, and nitrogen oxides. 60.52b Section 60.52b Protection of Environment... § 60.52b Standards for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a... (total mass), corrected to 7 percent oxygen. (d) The limits for nitrogen oxides are specified...

  8. Growth behavior of anodic oxide formed by aluminum anodizing in glutaric and its derivative acid electrolytes

    NASA Astrophysics Data System (ADS)

    Nakajima, Daiki; Kikuchi, Tatsuya; Natsui, Shungo; Suzuki, Ryosuke O.

    2014-12-01

    The growth behavior of anodic oxide films formed via anodizing in glutaric and its derivative acid solutions was investigated based on the acid dissociation constants of electrolytes. High-purity aluminum foils were anodized in glutaric, ketoglutaric, and acetonedicarboxylic acid solutions under various electrochemical conditions. A thin barrier anodic oxide film grew uniformly on the aluminum substrate by glutaric acid anodizing, and further anodizing caused the film to breakdown due to a high electric field. In contrast, an anodic porous alumina film with a submicrometer-scale cell diameter was successfully formed by ketoglutaric acid anodizing at 293 K. However, the increase and decrease in the temperature of the ketoglutaric acid resulted in non-uniform oxide growth and localized pitting corrosion of the aluminum substrate. An anodic porous alumina film could also be fabricated by acetonedicarboxylic acid anodizing due to the relatively low dissociation constants associated with the acid. Acid dissociation constants are an important factor for the fabrication of anodic porous alumina films.

  9. 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.

  10. Oxidative diversification of amino acids and peptides by small-molecule iron catalysis

    NASA Astrophysics Data System (ADS)

    Osberger, Thomas J.; Rogness, Donald C.; Kohrt, Jeffrey T.; Stepan, Antonia F.; White, M. Christina

    2016-09-01

    Secondary metabolites synthesized by non-ribosomal peptide synthetases display diverse and complex topologies and possess a range of biological activities. Much of this diversity derives from a synthetic strategy that entails pre- and post-assembly oxidation of both the chiral amino acid building blocks and the assembled peptide scaffolds. The vancomycin biosynthetic pathway is an excellent example of the range of oxidative transformations that can be performed by the iron-containing enzymes involved in its biosynthesis. However, because of the challenges associated with using such oxidative enzymes to carry out chemical transformations in vitro, chemical syntheses guided by these principles have not been fully realized in the laboratory. Here we report that two small-molecule iron catalysts are capable of facilitating the targeted C-H oxidative modification of amino acids and peptides with preservation of α-centre chirality. Oxidation of proline to 5-hydroxyproline furnishes a versatile intermediate that can be transformed to rigid arylated derivatives or flexible linear carboxylic acids, alcohols, olefins and amines in both monomer and peptide settings. The value of this C-H oxidation strategy is demonstrated in its capacity for generating diversity: four ‘chiral pool’ amino acids are transformed to twenty-one chiral unnatural amino acids representing seven distinct functional group arrays; late-stage C-H functionalizations of a single proline-containing tripeptide furnish eight tripeptides, each having different unnatural amino acids. Additionally, a macrocyclic peptide containing a proline turn element is transformed via late-stage C-H oxidation to one containing a linear unnatural amino acid.

  11. Oxidative diversification of amino acids and peptides by small-molecule iron catalysis

    NASA Astrophysics Data System (ADS)

    Osberger, Thomas J.; Rogness, Donald C.; Kohrt, Jeffrey T.; Stepan, Antonia F.; White, M. Christina

    2016-09-01

    Secondary metabolites synthesized by non-ribosomal peptide synthetases display diverse and complex topologies and possess a range of biological activities. Much of this diversity derives from a synthetic strategy that entails pre- and post-assembly oxidation of both the chiral amino acid building blocks and the assembled peptide scaffolds. The vancomycin biosynthetic pathway is an excellent example of the range of oxidative transformations that can be performed by the iron-containing enzymes involved in its biosynthesis. However, because of the challenges associated with using such oxidative enzymes to carry out chemical transformations in vitro, chemical syntheses guided by these principles have not been fully realized in the laboratory. Here we report that two small-molecule iron catalysts are capable of facilitating the targeted C–H oxidative modification of amino acids and peptides with preservation of α-centre chirality. Oxidation of proline to 5-hydroxyproline furnishes a versatile intermediate that can be transformed to rigid arylated derivatives or flexible linear carboxylic acids, alcohols, olefins and amines in both monomer and peptide settings. The value of this C–H oxidation strategy is demonstrated in its capacity for generating diversity: four ‘chiral pool’ amino acids are transformed to twenty-one chiral unnatural amino acids representing seven distinct functional group arrays; late-stage C–H functionalizations of a single proline-containing tripeptide furnish eight tripeptides, each having different unnatural amino acids. Additionally, a macrocyclic peptide containing a proline turn element is transformed via late-stage C–H oxidation to one containing a linear unnatural amino acid.

  12. 7-deoxyloganetic acid synthase catalyzes a key 3 step oxidation to form 7-deoxyloganetic acid in Catharanthus roseus iridoid biosynthesis.

    PubMed

    Salim, Vonny; Wiens, Brent; Masada-Atsumi, Sayaka; Yu, Fang; De Luca, Vincenzo

    2014-05-01

    Iridoids are key intermediates required for the biosynthesis of monoterpenoid indole alkaloids (MIAs), as well as quinoline alkaloids. Although most iridoid biosynthetic genes have been identified, one remaining three step oxidation required to form the carboxyl group of 7-deoxyloganetic acid has yet to be characterized. Here, it is reported that virus-induced gene silencing of 7-deoxyloganetic acid synthase (7DLS, CYP76A26) in Catharanthus roseus greatly decreased levels of secologanin and the major MIAs, catharanthine and vindoline in silenced leaves. Functional expression of this gene in Saccharomyces cerevisiae confirmed its function as an authentic 7DLS that catalyzes the 3 step oxidation of iridodial-nepetalactol to form 7-deoxyloganetic acid. The identification of CYP76A26 removes a key bottleneck for expression of iridoid and related MIA pathways in various biological backgrounds.

  13. 7-deoxyloganetic acid synthase catalyzes a key 3 step oxidation to form 7-deoxyloganetic acid in Catharanthus roseus iridoid biosynthesis.

    PubMed

    Salim, Vonny; Wiens, Brent; Masada-Atsumi, Sayaka; Yu, Fang; De Luca, Vincenzo

    2014-05-01

    Iridoids are key intermediates required for the biosynthesis of monoterpenoid indole alkaloids (MIAs), as well as quinoline alkaloids. Although most iridoid biosynthetic genes have been identified, one remaining three step oxidation required to form the carboxyl group of 7-deoxyloganetic acid has yet to be characterized. Here, it is reported that virus-induced gene silencing of 7-deoxyloganetic acid synthase (7DLS, CYP76A26) in Catharanthus roseus greatly decreased levels of secologanin and the major MIAs, catharanthine and vindoline in silenced leaves. Functional expression of this gene in Saccharomyces cerevisiae confirmed its function as an authentic 7DLS that catalyzes the 3 step oxidation of iridodial-nepetalactol to form 7-deoxyloganetic acid. The identification of CYP76A26 removes a key bottleneck for expression of iridoid and related MIA pathways in various biological backgrounds. PMID:24594312

  14. The effect of nitrous oxide plasma treatment on the bias temperature stress of metal oxide thin film transistors with high mobility

    NASA Astrophysics Data System (ADS)

    Tseng, Wei-Hao; Fang, Shao-Wei; Lu, Chia-Yang; Chuang, Hung-Yang; Chang, Fan-Wei; Lin, Guan-Yu; Chen, Tsu-Wei; Ma, Kang-Hung; Chen, Hong-Syu; Chen, Teng-Ke; Chen, Yu-Hung; Lee, Jen-Yu; Shih, Tsung-Hsiang; Ting, Hung-Che; Chen, Chia-Yu; Lin, Yu-Hsin; Hong, Hong-Jye

    2015-01-01

    In this work, the effects of nitrous oxide plasma treatment on the negative bias temperature stress of indium tin zinc oxide (ITZO) and indium gallium zinc oxide (IGZO) thin film transistors (TFTs) were reported. ITZO TFTs were more suitable for the back channel etched-type device structure because they could withstand both Al- and Cu-acid damage. The initial threshold voltage range could be controlled to within 1 V. The root cause of poor negative bias temperature stress for ITZO was likely due to a higher mobility (∼3.3 times) and more carbon related contamination bonds (∼5.9 times) relative to IGZO. Finally, 65″ active-matrix organic light-emitting diode televisions using the ITZO and IGZO TFTs were fabricated.

  15. Nitric-phosphoric acid oxidation of solid and liquid organic materials

    SciTech Connect

    Pierce, R.A.; Smith, J.R.; Poprik, D.C.

    1995-02-01

    Nitric-phosphoric acid oxidation has been developed specifically to address issues that face the Savannah River Site, other defense-related facilities, private industry, and small-volume generators such as university and medical laboratories. Initially tested to destroy and decontaminate SRS solid, Pu-contaminated job-control waste, the technology has also exhibited potential for remediating hazardous and mixed-hazardous waste forms. The process is unique to Savannah River and offers a valuable alternative to other oxidation processes that require extreme temperatures and/or elevated pressures. To address the broad categories of waste, many different organic compounds which represent a cross-section of the waste that must be treated have been successfully oxidized. Materials that have been quantitatively oxidized at atmospheric pressure below 180{degrees}C include neoprene, cellulose, EDTA, tributylphosphate, and nitromethane. More stable compounds such as benzoic acid, polyethylene, oils, and resins have been completely decomposed below 200{degrees}C and 10 psig. The process uses dilute nitric acid in a concentrated phosphoric acid media as the main oxidant for the organic compounds. Phosphoric acid allow nitric acid to be retained in solution well above its normal boiling point. The reaction forms NOx vapors which can be reoxidized and recycled using air and water. The addition of 0.001M Pd(II) reduces CO generation to near 1% of the released carbon gases. The advantages of this process are that it is straightforward, uses relatively inexpensive reagents, operates at relatively low temperature and pressure, and produces final solutions which are compatible with stainless steel equipment. For organic wastes, all carbon, hydrogen, and nitrogen are converted to gaseous products. If interfaced with an acid recovery system which converts NOx back to nitric acid, the net oxidizer would be oxygen from air.

  16. Extraction of benzene and naphthalene carboxylic acids using quaternary ammonium salts as a model study for the separation of coal oxidation products

    SciTech Connect

    Kawamura, K.; Nagano, H.; Okuwaki, A.

    2005-07-01

    The ion-pair solvent extraction of benzene- and naphthalene-carboxylic acids has been investigated as a model study for the separation of coal oxidation products, which are formed by treatment with alkaline solutions at high temperatures. It was possible that benzene- and naphthalene-dicarboxylic acids are extracted into several types of organic solvents with quaternary ammonium ions. The extraction equilibrium constants (K{sub ex}) for benzoic acid, 1,2-benzenedicarboxylic acid, 1,3-benzenedicarboxylic acid, 1-naphthoic acid, 2-naphthoic acid, 2,3-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid into chloroform were determined at 20{sup o}C. The difference of K{sub ex} among the aromatic acids was sufficiently large for designing a separation method for these aromatic acids. It was unexpected that the extraction of dicarboxylic acids was slower than that of monocarboxylic acids, although the ion-pair formation of aromatic carboxylate ion with quaternary ammonium ion is normally considered as a diffusion control reaction in aqueous phase. Thus, this fact suggests that the phase transfer of the ion-pair from aqueous to organic phase is the rate-determining step. Liner-free-energy relationship was observed for the monocarboxylic acids using different quaternary ammonium salts while that was ambiguous for the dicarboxylic acids. This is due to the steric influence of the counter ions for the magnitude of K{sub ex}.

  17. Protective effect of oleanolic acid on oxidized-low density lipoprotein induced endothelial cell apoptosis.

    PubMed

    Cao, Jianhua; Li, Guanghui; Wang, Meizhi; Li, Hui; Han, Zhiwu

    2015-10-01

    Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a naturally-occurring triterpenoid with various promising pharmacological properties. The present study was conducted to determine the protective effects of OA against oxidized low-density lipoprotein (ox-LDL) induced endothelial cell apoptosis and the possible underlying mechanisms. Our results showed that ox-LDL significantly decreased cell viability and induced apoptosis in human umbilical vein endothelial cells (HUVECs). OA in the co-treatment showed a protective effect against ox-LDL induced loss in cell viability and an increase in apoptosis, which was associated with the modulating effect of OA on ox-LDL induced hypoxia-inducible factor 1α(HIF-1α) expression. Moreover, our results showed that the modulating effect of OA against ox-LDL induced HIF-1α expression was obtained via inhibition of lipoprotein receptor 1 (LOX-1)/reactive oxygen species (ROS) signaling. Collectively, we suggested that the protective effect of OA against ox-LDL induced HUVEC apoptosis might, at least in part, be obtained via inhibition of the LOX-1/ROS/HIF-1α signaling pathway. PMID:26559024