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Sample records for acid dibenzothiophene dbt

  1. Deep catalytic oxidative desulfurization (ODS) of dibenzothiophene (DBT) with oxalate-based deep eutectic solvents (DESs).

    PubMed

    Lü, Hongying; Li, Pengcheng; Deng, Changliang; Ren, Wanzhong; Wang, Shunan; Liu, Pan; Zhang, Han

    2015-07-01

    An oxalate-based DES with a tetrabutyl ammonium chloride and oxalate acid molar ratio of 1/2 (TBO1 : 2) exhibited high activity in oxidative desulfurization (ODS) of dibenzothiophene (DBT) under mild reaction conditions. It is potentially a promising and highly environmentally friendly approach for desulfurization of fuels. PMID:26051675

  2. Oxidation of dibenzothiophene (DBT) by Serratia marcescens UCP 1549 formed biphenyl as final product

    PubMed Central

    2012-01-01

    Background The desulphurization of dibenzothiophene (DBT), a recalcitrant thiophenic fossil fuel component by Serratia marcescens (UCP 1549) in order for reducing the Sulphur content was investigated. The Study was carried out establishing the growth profile using Luria Bertani medium to different concentrations of DBT during 120 hours at 28°C, and orbital Shaker at 150 rpm. Results The results indicated that concentrations of DBT 0.5, 1.0 and 2.0 mM do not affected the growth of the bacterium. The DBT showed similar Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MCB) (3.68 mM). The desulphurization of DBT by S. marcescens was used with 96 hours of growth on 2 mM of DBT, and was determined by gas chromatography (GC) and GC-mass spectrometry. In order to study the desulphurization process by S. marcescens was observed the presence of a sulfur-free product at 16 hours of cultivation. Conclusions The data suggests the use of metabolic pathway “4S” by S. marcescens (UCP 1549) and formed biphenyl. The microbial desulphurization process by Serratia can be suggest significant reducing sulphur content in DBT, and showed promising potential for reduction of the sulfur content in diesel oil. PMID:22583489

  3. Desulfurization of dibenzothiophene by Corynebacterium sp. strain SY1

    SciTech Connect

    Omori, Toshio; Monna, L.; Saiki, Yuko; Kodama, Tohru )

    1992-03-01

    Strain SY1, identified as a Corynebacterium sp., was isolated on the basis of the ability to utilize dibenzothiophene (DBT) as a sole source of sulfur. Strain SY1 could utilize a wide range of organic and inorganic sulfur compounds, such as DBT sulfone, dimethyl sulfide, dimethyl sulfoxide, dimethyl sulfone, CS{sub 2}, FeS{sub 2}, and even elemental sulfur. Strain SY1 metabolized DBT to dibenzothiophene-5-oxide, DBT sulfone, and 2-hydroxybiphenyl, which was subsequently nitrated to produce at least two different hydroxynitrobiphenyls during cultivation. These metabolites were separated by silica gel column chromatography and identified by nuclear magnetic resonance, UV, and mass spectral techniques. Resting cells of SY1 desulfurized toluenesulfonic acid and released sulfite anion. On the basis of these results, a new DBT degradation pathway is proposed.

  4. Aerobic biodegradation of 2,2'-dithiodibenzoic acid produced from dibenzothiophene metabolites

    SciTech Connect

    Young, R.F.; Cheng, S.M.; Fedorak, P.M.

    2006-01-15

    Dibenzothiophene is a sulfur heterocycle found in crude oils and coal. The biodegradation of dibenzothiophene through the Kodama pathway by Pseudomonas sp. strain BT1d leads to the formation of three disulfides: 2-oxo-2-(2-thiophenyl)ethanoic acid disulfide, 2-oxo-2-(2-thiophenyl)ethanoic acid-2-benzoic acid disulfide, and 2,2'-dithiodibenzoic acid. When provided as the carbon and sulfur source in liquid medium, 2,2'-dithiodibenzoic acid was degraded by soil enrichment cultures. Two bacterial isolates, designated strains RM1 and RM6, degraded 2,2'-dithiodibenzoic acid when combined in the medium. Isolate RM6 was found to have an absolute requirement for vitamin B{sub 12}, and it degraded 2,2'-dithiodibenzoic acid in pure culture when the medium was supplemented with this vitamin. Isolate RM6 also degraded 2,2'-dithiodibenzoic acid in medium containing sterilized supernatants from cultures of isolate RM1 grown on glucose or benzoate. Isolate RM6 was identified as a member of the genus Variovorax using the Biolog system and 16S rRNA gene analysis. Although the mechanism of disulfide metabolism could not be determined, benzoic acid was detected as a transient metabolite of 2,2'-dithiodibenzoic acid biodegradation by Variovorax sp. strain RM6. In pure culture, this isolate mineralized 2,2'-dithiodibenzoic acid, releasing 59% of the carbon as carbon dioxide and 88% of the sulfur as sulfate.

  5. Ultraviolet Treatment and Biodegradation of Dibenzothiophene: Identification and Toxicity of Products

    PubMed Central

    Cooper, Ellen M.; Stapleton, Heather M.; Matson, Cole W.; Di Giulio, Richard T.; Schuler, Andrew J.

    2011-01-01

    Biodegradation of pollutants often results in incomplete mineralization and formation of degradation products with unknown chemical and toxicological characteristics. Ultraviolet (UV) irradiation, a common technology used in water and wastewater treatment, may help reduce aqueous concentrations of degradation products produced during biological treatment and their associated hazard. Combined biological and UV transformations may be important in natural systems as well. We investigated the effects of UV irradiation (254 nm) on dibenzothiophene (DBT), a sulfur-containing polyaromatic hydrocarbon, in artificial seawater, and its effects on biodegradation products produced from mixed-community microbial transformations of DBT, including DBT sulfone, DBT sulfoxide, hydroxylated and carboxylated benzothiophenes, thiosalicylic acid, and others. Toxicity of solutions following UV exposure was monitored using bioluminescent bacteria (Vibrio fischeri) and by evaluating cardiac deformities in Fundulus heteroclitus embryos. The highest UV fluence reduced DBT concentration by 28% when DBT was present as the sole organic solute. In post-biodegradation solution, the same fluence reduced initial concentration of DBT by 81%, and 11 DBT biodegradation products to trace levels. Regardless of UV fluence, DBT by itself produced minimal effects in Fundulus embryos but was moderately toxic to V. fischeri. Post-biodegradation solutions were highly toxic to both test organisms. The highest UV fluence slightly reduced toxicity of post-biodegradation solution to V. fischeri, but exacerbated cardiac deformities in Fundulus embryos. Toxicity could not be attributed to specific products, and was likely a result of mixture effects. These results emphasize that toxicity can increase during remediation and that multiple assays may be necessary for evaluation. The novel approach of combined biodegradation/UV treatment is promising, although further research is needed to reduce toxicity in the case

  6. Importance of structural and chemical heterogeneity of activated carbon surfaces for adsorption of dibenzothiophene

    SciTech Connect

    Ania, C.O.; Bandosz, T.J.

    2005-08-16

    The performance of various activated carbons obtained from different carbon precursors (i.e., plastic waste, coal, and wood) as adsorbents for the desulfurization of liquid hydrocarbon fuels was evaluated. To increase surface heterogeneity, the carbon surface was modified by oxidation with ammonium persulfate. The results showed the importance of activated carbon pore sizes and surface chemistry for the adsorption of dibenzothiophene (DBT) from liquid phase. Adsorption of DBT on activated carbons is governed by two types of contributions: physical and chemical interactions. The former include dispersive interactions in the microporous network of the carbons. While the volume of micropores governs the amount physisorbed, mesopores control the kinetics of the process. On the other hand, introduction of surface functional groups enhances the performance of the activated carbons as a result of specific interactions between the acidic centers of the carbon and the basic structure of DBT molecule as well as sulfur-sulfur interactions.

  7. Sequence and molecular characterization of a DNA region encoding the dibenzothiophene desulfurization operon of Rhodococcus sp. strain IGTS8.

    PubMed Central

    Piddington, C S; Kovacevich, B R; Rambosek, J

    1995-01-01

    Dibenzothiophene (DBT), a model compound for sulfur-containing organic molecules found in fossil fuels, can be desulfurized to 2-hydroxybiphenyl (2-HBP) by Rhodococcus sp. strain IGTS8. Complementation of a desulfurization (dsz) mutant provided the genes from Rhodococcus sp. strain IGTS8 responsible for desulfurization. A 6.7-kb TaqI fragment cloned in Escherichia coli-Rhodococcus shuttle vector pRR-6 was found to both complement this mutation and confer desulfurization to Rhodococcus fascians, which normally is not able to desulfurize DBT. Expression of this fragment in E. coli also conferred the ability to desulfurize DBT. A molecular analysis of the cloned fragment revealed a single operon containing three open reading frames involved in the conversion of DBT to 2-HBP. The three genes were designated dszA, dszB, and dszC. Neither the nucleotide sequences nor the deduced amino acid sequences of the enzymes exhibited significant similarity to sequences obtained from the GenBank, EMBL, and Swiss-Prot databases, indicating that these enzymes are novel enzymes. Subclone analyses revealed that the gene product of dszC converts DBT directly to DBT-sulfone and that the gene products of dszA and dszB act in concert to convert DBT-sulfone to 2-HBP. PMID:7574582

  8. Effects of solvents on deep hydrodesulfurization of benzothiophene and dibenzothiophene

    SciTech Connect

    Ishihara, Atsushi; Itoh, Tetsuro; Hino, Takuo; Nomura, Masatoshi; Pingyen Qi; Kabe, Toshiaki )

    1993-03-01

    Solvent effects on hydrodesulfurization (HDS) of benzothiophene (BT) and dibenzothiophene (DBT) catalyzed by Co-Mo/Al[sub 2]O[sub 3] were investigated under deep hydrodesulfurization conditions. Data for BT and DBT are arranged by the Langmuir-Hinshelwood equation. Activation energies of HDS of BT and DBT were approximately 21 and 24 kcal/mol respectively, in every solvent. Heats of adsorption of BT and DBT are both estimated to be 22 kcal/mol. Significant solvent effects were found under deep desulfurization conditions, and the values of heat of adsorption for various solvents were estimated from the K[sub sol] obtained. 14 refs., 3 figs., 3 tabs.

  9. Oxidation of benzothiophene, dibenzothiophene, and methyl-dibenzothiophene by ferrate(VI).

    PubMed

    Al-Abduly, Abdullah; Sharma, Virender K

    2014-08-30

    The reduction of sulfur content in liquid fuel is of a high concern environmentally, and oxydesulfurization approaches have shown high efficiency for removing thiophene-containing compounds from the liquid fuels. The present paper investigates the oxidation of benzothiophene (BT), dibenzothiophene (DBT), and 4-methyl-dibenzothiophene (4-MDBT) by ferrate(VI). The effects of reaction conditions such as the reaction medium pH, solvent type, and adsorbent on the reactivity of ferrate(VI) with the thiophene-containing compounds were investigated. The oxidation of DBT in phosphate-acetonitrile medium was found to be highly sensitive toward the reaction pH, and the highest removal efficiency was observed at the pH 8.0. The complete conversion of BT and DBT to their corresponding sulfones by ferrate(VI) was achieved at room temperature and [ferrate(VI)]/[BT/DBT]∼7.5 while this molar ratio was found to be ∼8.5 for 4-MDBT. The addition of silica gel during the reaction was applied to enhance the oxidation of DBT by ferrate(VI). PMID:25072136

  10. Cometabolic Degradation of Dibenzofuran and Dibenzothiophene by a Newly Isolated Carbazole-Degrading Sphingomonas sp. Strain▿

    PubMed Central

    Gai, Zhonghui; Yu, Bo; Li, Li; Wang, Ying; Ma, Cuiqing; Feng, Jinhui; Deng, Zixin; Xu, Ping

    2007-01-01

    A carbazole-utilizing bacterium was isolated by enrichment from petroleum-contaminated soil. The isolate, designated Sphingomonas sp. strain XLDN2-5, could utilize carbazole (CA) as the sole source of carbon, nitrogen, and energy. Washed cells of strain XLDN2-5 were shown to be capable of degrading dibenzofuran (DBF) and dibenzothiophene (DBT). Examination of metabolites suggested that XLDN2-5 degraded DBF to 2-hydroxy-6-(2-hydroxyphenyl)-6-oxo-2,4-hexadienic acid and subsequently to salicylic acid through the angular dioxygenation pathway. In contrast to DBF, strain XLDN2-5 could transform DBT through the ring cleavage and sulfoxidation pathways. Sphingomonas sp. strain XLDN2-5 could cometabolically degrade DBF and DBT in the growing system using CA as a substrate. After 40 h of incubation, 90% of DBT was transformed, and CA and DBF were completely removed. These results suggested that strain XLDN2-5 might be useful in the bioremediation of environments contaminated by these compounds. PMID:17337542

  11. Interactions of selected bacterial isolates with DBT and solubilized coal

    SciTech Connect

    Key, D.H.; Fox, R.V.; Kase, R.S.; Willey, M.S.; Stoner, D.L.; Ward, T.E.

    1990-01-01

    We are studying the interactions of isolated bacteria with dibenzothiophene (DBT), a sulfur-containing model compound, and with a solubilized coal product derived from a high-organic-sulfur lignite. The sensitivity of the tetrazolium assay used to identify and study these strains was improved by substituting tetrazolium violet for triphenyltetrazolium. DBT metabolism by thirteen strains was investigated using qualitative and quantitative GC and GC-MS analyses. Growth medium and incubation time affect the extent of DBT degradation and the production of DBT metabolites. Under specific conditions, seven of the strains produce metabolites which elute close to the position of one or another of the biphenyl standards. However, when these samples are spiked with the standard compounds, the bacterial metabolites do not co-elute with the standards. The modification of solubilized high-organic-sulfur coal by six of these strains was also studied. No selective removal of sulfur relative to carbon was observed. 13 refs., 1 fig., 2 tabs.

  12. Exploring the nature of interactions among thiophene, thiophene sulfone, dibenzothiophene, dibenzothiophene sulfone and a pyridinium-based ionic liquid.

    PubMed

    Gu, Peng; Lü, Renqing; Liu, Dong; Lu, Yukun; Wang, Shutao

    2014-06-14

    In order to gain an understanding of the nature of the interactions among thiophene (TS), thiophene sulfone (TSO2), dibenzothiophene (DBT), dibenzothiophene sulfone (DBTO2) and the ionic liquid N-butylpyridinium hydrogen sulfate ([BPY][HSO4]), a systematic investigation has been carried out using ab initio methods. The most stable structures indicate that both [BPY](+) and [HSO4](-) play crucial roles in the interactions between TS, TSO2, DBT, DBTO2 and [BPY][HSO4]. Analyses of the most stable optimized structures suggest the occurrence of steric effects, π-π stacking effects, hydrogen bonds, and dihydrogen bonds. The π-π stacking effect in [BPY][HSO4]-TSO2/[BPY][HSO4]-DBTO2 is less significant than that in [BPY][HSO4]-TS/[BPY][HSO4]-DBT, as TSO2 and DBTO2 are more nucleophilic than TS and DBT, resulting in stronger interactions between [BPY][HSO4] and TSO2/DBTO2 than between [BPY][HSO4] and TS/DBT. Thermodynamical data also demonstrate that TSO2/DBTO2 are more prone to interact with [BPY][HSO4] compared with TS/DBT. PMID:24741670

  13. Use of ferric sulfate: acid media for the desulfurization of model compounds of coal. [Dibenzothiophene, diphenyl sulfide, di-n-butyl sulfide

    SciTech Connect

    Clary, L.R.; Vermeulen, T.; Lynn, S.

    1980-12-01

    The objective of this work has been to investigate the ability of ferric sulfate-acid leach systems to oxidize the sulfur in model compounds of coal. Ferric iron-acid leach systems have been shown to be quite effective at removal of inorganic sulfur in coal. In this study, the oxidative effect of ferric iron in acid-leach systems was studied using dibenzothiophene, diphenyl sulfide, and di-n-butyl sulfide as models of organic sulfur groups in coal. Nitrogen and oxygen, as well as various transition metal catalysts and oxidants, were utilized in this investigation. Dibenzothiophene was found to be quite refractory to oxidation, except in the case where metavanadate was added, where it appears that 40% oxidation to sulfone could have occurred per hour at 150/sup 0/C and mild oxygen pressure. Diphenyl sulfide was selectively oxidized to sulfoxide and sulfone in an iron and oxygen system. Approximately 15% conversion to sulfone occurred per hour under these conditions. Some of the di-n-butyl sulfide was cracked to 1-butene and 1-butanethiol under similar conditions. Zinc chloride and ferric iron were used at 200/sup 0/C in an attempt to desulfonate dibenzothiophene sulfone, diphenyl sulfone, and di-n-butyl sulfone. Di-n-butyl sulfone was completely desulfurized on one hour and fragmented to oxidized parafins, while dibenzothiophene sulfone and diphenyl sulfone were unaffected. These results suggest that an iron-acid leach process could only selectively oxidize aryl sulfides under mild conditions, representing only 20% of the organic sulfur in coal (8% of the total sulfur). Removal through desulfonation once selective sulfur oxidation had occurred was only demonstrated for alkyl sulfones, with severe oxidation of the fragmented paraffins also occurring in one hour.

  14. Surface chemistry and catalytic properties of VOX/Ti-MCM-41 catalysts for dibenzothiophene oxidation in a biphasic system

    NASA Astrophysics Data System (ADS)

    González, J.; Chen, L. F.; Wang, J. A.; Manríquez, Ma.; Limas, R.; Schachat, P.; Navarrete, J.; Contreras, J. L.

    2016-08-01

    A series of vanadium oxide supported on Ti-MCM-41 catalysts was synthesized via the incipient impregnation method by varying the vanadia loading from 5 wt% to 10, 15, 20 and 25 wt%. These catalysts were characterized by a variety of advanced techniques for investigating their crystalline structure, textural properties, and surface chemistry information including surface acidity, reducibility, vanadium oxidation states, and morphological features. The catalytic activities of the catalysts were evaluated in a biphasic reaction system for oxidative desulfurization (ODS) of a model diesel containing 300 ppm of dibenzothiophene (DBT) where acetonitrile was used as extraction solvent and H2O2 as oxidant. ODS activity was found to be proportional to the V5+/(V4+ + V5+) values of the catalysts, indicating that the surface vanadium pentoxide (V2O5) was the active phase. Reaction temperature would influence significantly the ODS efficiency; high temperature, i.e., 80 °C, would lead to low ODS reaction due to the partial decomposition of oxidant. All the catalysts contained both Lewis and Brønsted acid sites but the former was predominant. The catalysts with low vanadia loading (5 or 10 wt%V2O5) had many Lewis acid sites and could strongly adsorb DBT molecule via the electron donation/acceptance action which resulted in an inhibition for the reaction of DBT with the surface peroxometallic species. The catalyst with high vanadia loading (25wt%V2O5/Ti-MCM-41) showed the highest catalytic activity and could remove 99.9% of DBT at 60 °C within 60 min.

  15. Deep desulfurization of light oil. 3. Effects of solvents on hydrodesulfurization of dibenzothiophene

    SciTech Connect

    Ishihara, Atsushi; Kabe, Toshiaki )

    1993-04-01

    Solvent effects on hydrodesulfurization (HDS) of dibenzothiophene (DBT) catalyzed by Co-Mo/Al[sub 2]O[sub 3] were investigated under deep hydrodesulfurization conditions. It was found that type of solvent affects HDS of DBT into biphenyl (BP). By contrast, the formation of cyclohexylbenzene (CHB) was scarcely affected by solvent such as xylene, decalin, tetralin, and n-hexadecane. From this result, it was suggested that desulfurization and hydrogenation proceed on different catalytic sites and that cyclohexylbenzene would be formed by hydrodesulfurization of hexahydrodibenzothiophene as well as hydrogenation of biphenyl.

  16. SULFUR REDUCTION IN GASOLINE AND DIESEL FUELS BY EXTRACTION/ADSORPTION OF REFRACTORY DIBENZOTHIOPHENES

    SciTech Connect

    Robert J. Angelici

    2003-06-01

    Refractory 4,6-dimethyldibenzothiophene, which is difficult to remove from petroleum feedstocks, binds to the Ru in Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+} by displacing the H{sub 2}O ligand. Thiophene, benzothiophene and dibenzothiophene (DBT) also react with Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+} similarly. This binding ability of Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+} has been used to remove over 50% of the DBT in simulated petroleum feedstocks by a biphasic extraction process. The extraction phase is readily regenerated by air-oxidation thereby completing a cyclic process that removes DBT from petroleum feedstocks. Solid phase extractants consisting of Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+}, CpRu(CO){sub 2}(BF{sub 4}), CpFe(CO){sub 2}(C{sub 4}H{sub 8}){sup +} and AgX (where X = BF{sub 4}{sup -}, PF{sub 6}{sup -} or NO{sub 3}{sup -}) adsorbed on silica have also been used to remove DBT and 4,6-Me{sub 2}DBT from simulated petroleum feedstocks. The AgX/silica adsorbents remove 90% of the DBT and 4,6-Me{sub 2}DBT and can be regenerated and re-used for multiple extractions, which makes these adsorbents of potential industrial use for the removal of refractory dibenzothiophenes from petroleum feedstocks.

  17. Dibenzothiophene desulfurization capability and evolutionary divergence of newly isolated bacteria.

    PubMed

    Akhtar, Nasrin; Ghauri, Muhammad A; Akhtar, Kalsoom

    2016-08-01

    Metabolically microorganisms are diverse, and they are capable of transforming almost every known group of chemical compounds present in coal and oil in various forms. In this milieu, one of the important microbial metabolic processes is the biodesulfurization [cleavage of carbon-sulfur (C-S) bond] of thiophenic compounds, such as dibenzothiophene (DBT), which is the most abundant form of organic sulfur present in fossil fuels. In the current study, ten newly isolated bacterial isolates, designated as species of genera Gordonia, Amycolatopsis, Microbacterium and Mycobacterium, were enriched from different samples in the presence of DBT as a sole source of organic sulfur. The HPLC analysis of the DBT grown cultures indicated the consumption of DBT and accumulation of 2-hydroxybiphenyl (2-HBP). Detection of 2-HBP, a marker metabolite of 4S (sulfoxide-sulfone-sulfinate-sulfate) pathway, suggested that the newly isolated strains harbored metabolic activity for DBT desulfurization through the cleavage of C-S bond. The maximum 2-HBP formation rate was 3.5 µmol/g dry cell weight (DCW)/h. The phylogenetic analysis of the new isolates showed that they had diverse distribution within the phylogenetic tree and formed distinct clusters, suggesting that they might represent strains of already reported species or they were altogether new species. Estimates of evolutionary divergence showed high level of nucleotide divergence between the isolates within the same genus. The new isolates were able to use a range of heterocyclic sulfur compounds, thus making them suitable candidates for a robust biodesulfurization system for fossil fuels. PMID:26973057

  18. Dibenzothiophene Catabolism Proceeds via a Flavin-N5-oxide Intermediate.

    PubMed

    Adak, Sanjoy; Begley, Tadhg P

    2016-05-25

    The dibenzothiophene catabolic pathway converts dibenzothiophene to 2-hydroxybiphenyl and sulfite. The third step of the pathway, involving the conversion of dibenzothiophene sulfone to 2-(2-hydroxyphenyl)-benzenesulfinic acid, is catalyzed by a unique flavoenzyme DszA. Mechanistic studies on this reaction suggest that the C2 hydroperoxide of dibenzothiophene sulfone reacts with flavin to form a flavin-N5-oxide. The intermediacy of the flavin-N5-oxide was confirmed by LC-MS analysis, a co-elution experiment with chemically synthesized FMN-N5-oxide and (18)O2 labeling studies. PMID:27120486

  19. Purification and characterization of a carbon-sulfur lyase (aryl desulfinase) from rhodococcus Sp. IGTS8 involved in desulfurization of dibenzothiophene

    SciTech Connect

    Mrachko, G.T.; Gray, K.A.

    1996-12-31

    Biocatalysts are being developed at Energy BioSystems Corporation to remove sulfur from sulfur-containing organic molecules found in fossil fuel without decreasing the carbon content of the fuel. A metabolic pathway has been discovered in the Gram positive organism Rhodococcus sp IGTS8 consisting of four enzymes which converts dibenzothiophene (DBT), a major organosulfur constituent in middle distillate, to 2-hydroxybiphenyl (HBP) and sulfite. The final enzyme in this pathway (encoded by dszB) catalyzes a reaction of which there are few examples involving the formation of sulfite from 2-(2-hydroxyphenyl)benzene sulfuric acid to yield HBP. The desulfinase has been purified and characterized both kinetically and physically. We report on chemical modification and other enzyme mechanism studies of this protein. The reaction is presented in light of chemical precedents and the results are summarized in the form of a proposed enzyme reaction mechanism.

  20. SULFUR REDUCTION IN GASOLINE AND DIESEL FUELS BY EXTRACTION/ADSORPTION OF REFRACTORY DIBENZOTHIOPHENES

    SciTech Connect

    Robert J. Angelici; Scott G. McKinley; Celedonio Alvarez

    2001-10-01

    Using the classical coordination compound, Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+}, they have prepared a metal complex with a 4,6-dimenthyldibenzothiophene ligand. The compound Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+} also reacts with thiophene, benzothiophene and dibenzothiophene (DBT) at room temperature. They have found that Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+} removes over 50% of the DBT in simulated petroleum feedstocks by a biphasic extraction process. The extraction phase is readily generated by air-oxidation thereby completing a cyclic process that removes DBT from petroleum feedstocks.

  1. Enhanced dibenzothiophene biodesulfurization by immobilized cells of Brevibacterium lutescens in n-octane-water biphasic system.

    PubMed

    Dai, Yong; Shao, Rong; Qi, Gang; Ding, Bin-Bin

    2014-11-01

    In this study, it was the first report that the Brevibacterium lutescens CCZU12-1 was employed as a sulfur removing bacteria. Using dibenzothiophene (DBT) as the sole sulfur source, B. lutescens could selectively degrade DBT into 2-hydroxybiphenyl (2-HBP) via the "4S" pathway. In the basal salt medium (BSM) supplemented with 0.25 mM DBT and 0.5 g/L Tween-80, high desulfurization rate (100 %) was obtained by growth cells after 60 h. Furthermore, the n-octane-water (10:90, v/v) biphasic system was built for the biodesulfurization by resting cells. Moreover, a combination of magnetic nano Fe3O4 particles with calcium alginate immobilization was used for enhancing biodesulfurization. In this n-octane-water biphasic system, immobilized B. lutescens cells could be reused for not less than four times. Therefore, B. lutescens CCZU12-1 shows high potential in the biodesulfurization. PMID:25173674

  2. Drosophila DBT Autophosphorylation of Its C-Terminal Domain Antagonized by SPAG and Involved in UV-Induced Apoptosis.

    PubMed

    Fan, Jin-Yuan; Means, John C; Bjes, Edward S; Price, Jeffrey L

    2015-07-01

    Drosophila DBT and vertebrate CKIε/δ phosphorylate the period protein (PER) to produce circadian rhythms. While the C termini of these orthologs are not conserved in amino acid sequence, they inhibit activity and become autophosphorylated in the fly and vertebrate kinases. Here, sites of C-terminal autophosphorylation were identified by mass spectrometry and analysis of DBT truncations. Mutation of 6 serines and threonines in the C terminus (DBT(C/ala)) prevented autophosphorylation-dependent DBT turnover and electrophoretic mobility shifts in S2 cells. Unlike the effect of autophosphorylation on CKIδ, DBT autophosphorylation in S2 cells did not reduce its in vitro activity. Moreover, overexpression of DBT(C/ala) did not affect circadian behavior differently from wild-type DBT (DBT(WT)), and neither exhibited daily electrophoretic mobility shifts, suggesting that DBT autophosphorylation is not required for clock function. While DBT(WT) protected S2 cells and larvae from UV-induced apoptosis and was phosphorylated and degraded by the proteasome, DBT(C/ala) did not protect and was not degraded. Finally, we show that the HSP-90 cochaperone spaghetti protein (SPAG) antagonizes DBT autophosphorylation in S2 cells. These results suggest that DBT autophosphorylation regulates cell death and suggest a potential mechanism by which the circadian clock might affect apoptosis. PMID:25939385

  3. Dibenzothiophene adsorption at boron doped carbon nanoribbons studied within density functional theory

    SciTech Connect

    López-Albarrán, P.; Navarro-Santos, P.; Garcia-Ramirez, M. A.; Ricardo-Chávez, J. L.

    2015-06-21

    The adsorption of dibenzothiophene (DBT) on bare and boron-doped armchair carbon nanoribbons (ACNRs) is being investigated in the framework of the density functional theory by implementing periodic boundary conditions that include corrections from dispersion interactions. The reactivity of the ACNRs is characterized by using the Fukui functions as well as the electrostatic potential as local descriptors. Non-covalent adsorption mechanism is found when using the local Perdew-Becke-Ernzerhof functional, regardless of the DBT orientation and adsorption location. The dispersion interactions addition is a milestone to describe the adsorption process. The charge defects introduced in small number (i.e., by doping with B atoms), within the ACNRs increases the selectivity towards sulfur mainly due to the charge depletion at B sites. The DBT magnitude in the adsorption energy shows non-covalent interactions. As a consequence, the configurations where the DBT is adsorbed on a BC{sub 3} island increase the adsorption energy compared to random B arrangements. The stability of these configurations can be explained satisfactorily in terms of dipole interactions. Nevertheless, from the charge-density difference analysis and the weak Bader charge-distribution interactions cannot be ruled out completely. This is why the electronic properties of the ribbons are analyzed in order to elucidate the key role played by the B and DBT states in the adsorbed configurations.

  4. Crystallization and preliminary structural analysis of dibenzothiophene monooxygenase (DszC) from Rhodococcus erythropolis

    PubMed Central

    Duan, Xiaolu; Zhang, Liang; Zhou, Daming; Ji, Kaihua; Ma, Ting; Shui, Wenqing; Li, Guoqiang; Li, Xin

    2013-01-01

    Dibenzothiophene (DBT) and its derivatives are typical sulfur compounds found in fossil fuels. These compounds show resistance to the hydrodesulfuriz­ation treatment that is commonly used in industry. Dibenzothiophene monooxygenase (DszC) is responsible for the oxidation of DBT, which is the first and the rate-limiting step in the DBT enzymatic desulfurization 4S pathway. In this study, the crystal structure of DszC from Rhodococcus erythropolis DS-3 is reported. The crystal of native DszC belonged to space group P1, with unit-cell parameters a = 96.16, b = 96.27, c = 98.56 Å, α = 81.03, β = 67.57, γ = 85.84°. To determine the phase, SAD X-ray diffraction data were collected from a SeMet-derivative DszC crystal, which also belonged to space group P1, with unit-cell parameters a = 95.379, b = 95.167, c = 94.891 Å, α = 87.046, β = 70.536, γ = 79.738°. Further structural analysis of DszC is in progress. PMID:23722833

  5. Hydrodesulfurization of dibenzothiophene over Mo-based dispersed catalysts

    SciTech Connect

    Song, C.; Cooke, W.S.; Eckhardt, S.

    1995-12-31

    The hydrodesulfurization (HDS) and hydrocracking (HC) activity and selectivity of several Mo-based catalyst precursors have been examined in model compound reactions of dibenzothiophene (DBT). Reactions were carried out at 400{degrees}C with 6.9 MN of H{sub 2} for 30 min. A metal loading of 0.5 mol% (based on DBT) in tridecane as solvent resulted in a low conversion rate and only hydrogenation products. Even the addition of sulfur to the catalyst in a 4:1 molar ratio only led to a minor increase in conversion and HDS. However, a change in the molar ratio of solvent to model compound from 1:1 to 19:1 and a metal loading of 33.16 mol% lead to a dramatic increase in conversion, HDS, and HC. Furthermore, the use of higher boiling point solvents such as hexadecane and octadecane had a beneficial effect on both HDS and HC. The addition of sulfur in a 6:1 ratio of S:metal to the higher-metal-loaded runs had varying effects that were dependent upon the catalyst used.

  6. Transition Metal Complexes of Cr, Mo, W and Mn Containing {eta}{sup 1}(S)-2,5-Dimethylthiophene, Benzothiophene and Dibenzothiophene Ligands

    SciTech Connect

    Reynolds, M.

    2000-09-21

    The UV photolysis of hexanes solutions containing the complexes M(CO){sub 6} (M=Cr, Mo, W) or CpMn(CO){sub 3} (Cp={eta}{sup 5}-C{sub 5}H{sub 5}) and excess thiophene (T{sup *}) (T{sup *}=2,5-dimethylthiophene (2,5-Me{sub 2}T), benzothiophene (BT), and dibenzothiophene (DBT)) produces the {eta}{sup 1}(S)-T{sup *} complexes (CO){sub 5}M({eta}{sup 1}(S)-T{sup *}) 1-8 or Cp(CO){sub 2}Mn({eta}{sup 1}(S)-T{sup *})9-11, respectively. However, when T{sup *}=DBT, and M=Mo, a mixture of two products result which includes the {eta}{sup 1}(S)-DBT complex (CO){sub 5}Mo({eta}{sup 1}(S)-DBT) 4a and the unexpected {pi}-complex (CO){sub 3}Mo({eta}{sup 6}-DBT) 4b as detected by {sup 1}H NMR. The liability of the {eta}{sup 1}(S)-T{sup *} ligands is illustrated by the rapid displacement of DBT in the complex (CO){sub 5}W({eta}{sup 1}(S)-DBT) (1) by THF, and also in the complexes (CO){sub 5}Cr({eta}{sup 1}(S)-DBT) (5) and CpMn(CO){sub 2}({eta}{sup 1}(S)-DBT) (9) by CO (1 atm) at room temperature. Complexes 1-11 have been characterized spectroscopically ({sup 1}H NMR, IR) and when possible isolated as analytically pure solids (elemental analysis, EIMS). Single crystal, X-ray structural determinations are reported for (CO){sub 5}W({eta}{sup 1}(S)-DBT) and Cp(CO){sub 2}Mn({eta}{sup 1}(S)-DBT).

  7. Bacterial Transformations of 1,2,3,4-Tetrahydrodibenzothiophene and Dibenzothiophene

    PubMed Central

    Kropp, K. G.; Andersson, J. T.; Fedorak, P. M.

    1997-01-01

    The transformations of 1,2,3,4-tetrahydrodibenzothiophene (THDBT) were investigated with pure cultures of hydrocarbon-degrading bacteria. Metabolites were extracted from cultures with dichloromethane (DCM) and analyzed by gas chromatography (GC) with flame photometric, mass, and Fourier transform infrared detectors. Three 1-methylnaphthalene (1-MN)-utilizing Pseudomonas strains oxidized the sulfur atom of THDBT to give the sulfoxide and sulfone. They also degraded the benzene ring to yield 3-hydroxy-2-formyl-4,5,6,7-tetrahydrobenzothiophene. A cell suspension of a cyclohexane-degrading bacterium oxidized the alicyclic ring to give a hydroxy-substituted THDBT and a ketone, and it oxidized the aromatic ring to give a phenol, but no ring cleavage products were detected. GC analyses with an atomic emission detector, using the sulfur-selective mode, were used to quantify the transformation products from THDBT and dibenzothiophene (DBT). The cyclohexane degrader oxidized 19% of the THDBT to three metabolites. The cometabolism of THDBT and DBT by the three 1-MN-grown Pseudomonas strains resulted in a much greater depletion of the condensed thiophenes than could be accounted for in the metabolites detected by GC analysis, but there was no evidence of sulfate release from DBT. These 1-MN-grown strains transiently accumulated 3-hydroxy-2-formylbenzothiophene (HFBT) from DBT, but it was subsequently degraded. On the other hand, Pseudomonas strain BT1d, which was maintained on DBT as a sole carbon source, accumulated 52% of the sulfur from DBT as HFBT over 7 days, and, in total, 82% of the sulfur from DBT was accounted for by the GC method used. Lyophilization of cultures grown on 1-MN with DBT and methyl esterification of the residues gave improved recoveries of total sulfur over that obtained by DCM extraction and GC analysis. This suggested that the further degradation of HFBT by these cultures leads to the formation of organosulfur compounds that are too polar to be

  8. Identification of disulfides from the biodegradation of dibenzothiophene.

    PubMed

    Bressler, D C; Fedorak, P M

    2001-11-01

    Several investigations have identified benzothiophene-2,3-dione in the organic solvent extracts of acidified cultures degrading dibenzothiophene via the Kodama pathway. In solution at neutral pH, the 2,3-dione exists as 2-mercaptophenylglyoxylate, which cyclizes upon acidification and is extracted as the 2,3-dione. The fate of these compounds in microbial cultures has never been determined. This study investigated the abiotic reactions of 2-mercaptophenylglyoxylate incubated aerobically in mineral salts medium at neutral pH. Oxidation led to the formation of 2-oxo-2-(2-thiophenyl)ethanoic acid disulfide, formed from two molecules of 2-mercaptophenylglyoxylate. Two sequential abiotic, net losses of both a carbon and an oxygen atom produced two additional disulfides, 2-oxo-2-(2-thiophenyl)ethanoic acid 2-benzoic acid disulfide and 2,2'-dithiosalicylic acid. The methods developed to extract and detect these three disulfides were then used for the analysis of a culture of Pseudomonas sp. strain BT1d grown on dibenzothiophene as its sole carbon and energy source. All three of the disulfides were detected, indicating that 2-mercaptophenylglyoxylate is an important, short-lived intermediate in the breakdown of dibenzothiophene via the Kodama pathway. The disulfides eluded previous investigations because of (i) their high polarity, being dicarboxylic acids; (ii) the need to lower the pH of the aqueous medium to <1 to extract them into an organic solvent such as dichloromethane; (iii) their poor solubility in organic solvents, (iv) their removal from organic extracts of cultures during filtration through the commonly used drying agent anhydrous sodium sulfate; and (v) their high molecular masses (362, 334, and 306 Da) compared to that of dibenzothiophene (184 Da). PMID:11679330

  9. SULFUR REDUCTION IN GASOLINE AND DIESEL FUELS BY EXTRACTION/ADSORPTION OF REFRACTORY DIBENZOTHIOPHENES

    SciTech Connect

    Scott G. McKinley; Celedonio M. Alvarez

    2003-03-01

    The purpose of this study was to remove thiophene, benzothiophene and dibenzothiophene from a simulated gasoline feedstock. We found that Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+} reacts with a variety of thiophenes (Th*), affording Ru(NH{sub 3}){sub 5}(Th*){sup 2+}. We used this reactivity to design a biphasic extraction process that removes more than 50% of the dibenzothiophene in the simulated feedstock. This extraction system consists of a hydrocarbon phase (simulated petroleum feedstock) and extractant Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+} in an aqueous phase (70% dimethylformamide, 30% H{sub 2}O). The DBT is removed in situ from the newly formed Ru(NH{sub 3}){sub 5}(DBT){sup 2+} by either an oxidation process or addition of H{sub 2}O, to regenerate Ru(NH{sub 3}){sub 5}(H{sub 2}O){sup 2+}.

  10. Transition metal complexes of chromium, molybdenum, tungsten, and manganese containing {eta}{sup 1}(S)-2,5-dimethylthiophene, benzothiophene, and dibenzothiophene ligands

    SciTech Connect

    Reynolds, M.A.; Guzei, I.A.; Logsdon, B.C.; Thomas, L.M.; Jacobson, R.A.; Angelici, R.J.

    1999-09-27

    Ultraviolet photolysis of hexanes solutions containing the complexes M(CO){sub 6} (M = Cr, Mo, W) or CpMn(CO){sub 3}(Cp = {eta}{sup 5}{minus}C{sub 5}H{sub 5}) and excess thiophene (T*)(T* = 2,5-dimethylthiophene (2,5-Me{sub 2}T), benzothiophene (BT), or dibenzothiophene (DBT)) produces the {eta}{sup 1}(S)=T* complexes (CO){sub 5}M({eta}{sup 1}(S)-T*) 1--8 or Cp(CO){sub 2}Mn({eta}{sup 1}(S)-T*) 9--11, respectively. However, when T* = DBT and M = Mo, a mixture of two products results, which includes (CO){sub 5}Mo({eta}{sup 1}(S)-DBT), 4a, and the {pi}-complex (CO){sub 3}Mo({eta}{sup 6}-DBT), 4b, as detected by {sup 1}H NMR spectroscopy. Only the complexes (CO){sub 5}W({eta}{sup 1}(S)-DBT) (1), (CO){sub 5}Cr({eta}{sup 1}(S)-DBT) (5), and Cp(CO){sub 2}Mn({eta}{sup 1}(S)-DBT) (9) were sufficiently stable (several days) to be isolated and characterized by elemental analyses. Rates of DBT ligand displacement by co (1 atm) at room temperature decreased in the order 5 > 1 > 9. Single-crystal, X-ray structural determinations are reported for 1, 5, and 9. The tilt angle ({phi}) of the DBT ligand in these and related complexes is discussed in terms of {pi}-back-bonding to the DBT ligand.

  11. Rate-limiting step analysis of the microbial desulfurization of dibenzothiophene in a model oil system.

    PubMed

    Abin-Fuentes, Andres; Leung, James C; Mohamed, Magdy El-Said; Wang, Daniel I C; Prather, Kristala L J

    2014-05-01

    A mechanistic analysis of the various mass transport and kinetic steps in the microbial desulfurization of dibenzothiophene (DBT) by Rhodococcus erythropolis IGTS8 in a model biphasic (oil-water), small-scale system was performed. The biocatalyst was distributed into three populations, free cells in the aqueous phase, cell aggregates and oil-adhered cells, and the fraction of cells in each population was measured. The power input per volume (P/V) and the impeller tip speed (vtip ) were identified as key operating parameters in determining whether the system is mass transport controlled or kinetically controlled. Oil-water DBT mass transport was found to not be limiting under the conditions tested. Experimental results at both the 100 mL and 4 L (bioreactor) scales suggest that agitation leading to P/V greater than 10,000 W/ m(3) and/or vtip greater than 0.67 m/s is sufficient to overcome the major mass transport limitation in the system, which was the diffusion of DBT within the biocatalyst aggregates. PMID:24284557

  12. Rate-limiting step analysis of the microbial desulfurization of dibenzothiophene in a model oil system

    PubMed Central

    Abin-Fuentes, Andres; Leung, James C.; Mohamed, Magdy El-Said; Wang, Daniel IC; Prather, Kristala LJ

    2014-01-01

    A mechanistic analysis of the various mass transport and kinetic steps in the microbial desulfurization of dibenzothiophene (DBT) by Rhodococcus erythropolis IGTS8 in a model biphasic (oil-water), small-scale system was performed. The biocatalyst was distributed into three populations, free cells in the aqueous phase, cell aggregates and oil-adhered cells, and the fraction of cells in each population was measured. The power input per volume (P/V) and the impeller tip speed (vtip) were identified as key operating parameters in determining whether the system is mass transport controlled or kinetically controlled. Oil-water DBT mass transport was found to not be limiting under the conditions tested. Experimental results at both the 100 mL and 4L (bioreactor) scales suggest that agitation leading to P/V greater than 10,000 W/ m3 and/or vtip greater than 0.67 m/s is sufficient to overcome the major mass transport limitation in the system, which was the diffusion of DBT within the biocatalyst aggregates. PMID:24284557

  13. Synthesis and Lanthanide Coordination Chemistry of Phosphine Oxide Decorated Dibenzothiophene and Dibenzothiophene Sulfone Platforms

    SciTech Connect

    Rosario-Amorin, Daniel; Ouizem, Sabrina; Dickie, D. A.; Paine, Robert T.; Cramer, Roger E.; Hay, Benjamin; Podair, Julien; Delmau, Laetitia Helene

    2014-01-01

    Syntheses for new ligands based upon dibenzothiophene and dibenzothiophene sulfone platforms, decorated with phosphine oxide and methylphosphine oxide donor groups, are described. Coordination chem. of 4, 6- bis(diphenylphosphinoylmethyl) dibenzothiophene (8) , 4, 6- bis(diphenylphosphinoylmethyl) dibenzothiophene- 5, 5- dioxide (9) and 4, 6- bis(diphenylphosphinoyl) dibenzothiophene- 5, 5- dioxide (10) with lanthanide nitrates, Ln(NO3) 3 (H2O) n is outlined, and crystal structure detns. reveal a range of chelation interactions on Ln(III) ions. The HNO3 dependence of the solvent extn. performance of 9 and 10 in 1, 2- dichloroethane for Eu(III) and Am(III) is described and compared against the extn. behavior of related dibenzofuran ligands (2, 3; R = Ph) and n- octyl(phenyl) - N, N- diisobutylcarbamoylmethyl phosphine oxide (4) measured under identical conditions.

  14. A novel metabolite (1,3-benzenediol, 5-hexyl) production by Exophiala spinifera strain FM through dibenzothiophene desulfurization.

    PubMed

    Elmi, Fatemeh; Etemadifar, Zahra; Emtiazi, Giti

    2015-05-01

    Sulfur dioxide which is released from petroleum oil combustion causes pollution over the atmosphere and the soil. Biodesulfurization can be used as a complementary method of hydrodesulfurization, the common method of petroleum desulfurization in refineries. Many studies have been carried out to develop biological desulfurization of dibenzothiophene (DBT) with bacterial biocatalysts. However, fungi are capable to metabolize a wide range of aromatic hydrocarbons through cytochrome P450 and their extracellular enzymes. The aim of the present work was isolation and identification of fungi biocatalysts capable for DBT utilization as sulfur source and production of novel metabolites. DBT consumption and the related produced metabolites were analyzed by HPLC and GC-MS respectively. One of the isolated fungi that could utilize DBT as sole sulfur source was identified by both traditional and molecular experiments and registered in NCBI as Exophiala spinifera FM strain (accession no. KC952672). This strain could desulfurize 99 % of DBT (0.3 mM) as sulfur source by co-metabolism reaction with other carbon sources through the same pathway as 4S and produced 2-hydroxy biphenyl (2-HBP) during 7 days of incubation at 30 °C and 180 rpm shaking. However, the isolate was able to transform 2-HBP to 1,3-benzenediol, 5-hexyl. While biphenyl compounds are toxic to leaving cells, biotransformation of them can reduce their toxicity and the fungi will be more tolerant to the final product. These data are the first report about the desulfurization of DBT comparable to 4S-pathway and production of innovative metabolite by E. spinifera FM strain. PMID:25752234

  15. Therapists' Use of DBT: A Survey Study of Clinical Practice

    ERIC Educational Resources Information Center

    DiGiorgio, Kimberly E.; Glass, Carol R.; Arnkoff, Diane B.

    2010-01-01

    The purpose of this study was to examine how therapists conduct Dialectical Behavior Therapy (DBT) individual psychotherapy with clients, focusing on clinical factors that could account for decisions regarding modifications of DBT (e.g., client diagnosis, therapist theoretical orientation, and intensity of DBT training). Additionally, the study…

  16. Oxidation of dibenzothiophene catalyzed by hemoglobin and other hemoproteins in various aqueous-organic media

    SciTech Connect

    Klyachko, N.L. Klibanov, A.M. )

    1992-10-01

    Biocatalytic oxidation of dibenzothiophene (a model of organic sulfur in coal) with hydrogen peroxide was investigated. It was found that various hemoproteins, both enzymic (e.g., horseradish peroxidase) and nonenzymic (e.g., bovine blood hemoglobin), readily oxidized dibensothiophene to its S-oxide and, to a minor extent, further to its S-dioxide (sulfone). This process catalyzed by hemoglobin was competent as an oxidation catalyst even in nearly dry organic solvents (with protic, acidic solvents being optimal), the highest conversions were observed in predominantly aqueous media. The hemoglobin-catalyzed oxidation of dibenzothiophene at low concentrations of the protein stopped long before all the substrate was oxidized. This phenomenon was caused by inactivation of hemoglobin by hydrogen peroxide that destroyed the heme moiety. The maximal degree of the hemoglobin-catalyzed dibenzothiophene oxidation was predicted, and found, to be strongly dependent on the reaction medium composition. 24 refs., 7 figs., 3 tabs.

  17. Visible photooxidation of dibenzothiophenes sensitized by 2-(4-methoxyphenyl)-4, 6-diphenylpyrylium: an electron transfer mechanism without involvement of superoxide.

    PubMed

    Che, Yanke; Ma, Wanhong; Ji, Hongwei; Zhao, Jincai; Zang, Ling

    2006-02-16

    We report here on a new electron-transfer mechanism for visible-light photooxidation of sulfides in which no superoxide ion is involved. Visible-light irradiation of 2-(4-methoxyphenyl)-4, 6-diphenylpyrylium tetrafluoroborate (MOPDPP(+)BF(4)(-)) in an O(2)-saturated acetonitrile solution containing dibenzothiophene (DBT) results in nearly 100% conversion to oxygenated products, DBT sulfoxide and sulfone. The photooxidation of DBT is initiated by a photoinduced electron-transfer process, where the excited MOPDPP(+) traps an electron from the ground-state DBT to form MOPDPP(*) and DBT radical cation. Such a mechanism is consistent with the studies of laser flash photolysis, electron spin resonance, and fluorescence quenching of the irradiated system. The photogenerated DBT radical cation undergoes a coupling reaction with O(2) to produce the intermediate responsible for the formation of the oxygenated products. The presence of O(2) has no effect on the decay kinetics of the transient absorption of MOPDPP(*), indicating that no redox reaction occurs between MOPDPP(*) and O(2), and thus no superoxide ion (O(2)(*-)) is formed. Moreover, the ESR signal of MOPDPP(*) was significantly enhanced in the presence of O(2), consistent with the assumption that the photogenerated DBT radical cation couples with O(2) to form the oxygen-adduct, which is subject to further reactions (Scheme 3) leading to the final oxygenated products. Similar results have been obtained when using 10-methylacridine hexafluorophosphate (AcrH(+)PF(6)(-), which has similar reduction potential in the ground state as MOPDPP(+)) as the sensitizer. This finding provides a possibility for the photooxidation of sulfides with dioxygen utilizing visible light (solar energy) and is also of significance in clarification of the reaction mechanism. PMID:16471905

  18. Identification of a new operon involved in desulfurization of dibenzothiophenes using a metagenomic study and cloning and functional analysis of the genes.

    PubMed

    Abbasian, Firouz; Lockington, Robin; Megharaj, Mallavarapu; Naidu, Ravi

    2016-06-01

    The presence of sulphur-substituted hydrocarbons in fossil fuels are one of main reasons for the release of sulfur oxides into the environment. Dibenzothiophenes (DBT) are organic sulfur-containing molecules in crude oil, which have the potential for biological oxidation, with the sulphur being removed through an enzymatic cleavage of the CS bonds. Therefore, finding new strains that can desulfurize this compound has recently become a point of interest. In this study, three new genes involved in the bacterial desulfurization of Dibenzothiophene, which were sequenced in the course of a metagenomic study, were isolated by PCR amplification in the laboratory. The activities of these genes were then analysed following insertion into an expression vector and cloning in Escherichia coli DH5α cells. Based on the results, all three genes were actively expressed and their products could act on their corresponding substrates. PMID:27178791

  19. Biodesulfurization of dibenzothiophene and crude oil using electro-spray reactors

    SciTech Connect

    Kaufman, E.N.; Harkins, J.B.; Rodriguez, M.; Tsouris, C.; Selvaraj, P.T.

    1996-10-01

    Biological removal of organic sulfur from petroleum feedstocks offers an attractive alternative to conventional thermochemical treatment due to the mild operating conditions afforded by the biocatalyst. In order for biodesulfurization to realize commercial success, reactors must be designed which allow for sufficient liquid / liquid and gas / liquid mass transfer while simultaneously reducing operating costs. In this study, the use of electric field contactors for the biodesulfurization of the model compound dibenzothiophene (DBT) as well as actual crude oil is investigated. The emulsion phase contactor (EPC) creates an emulsion of aqueous biocatalyst in the organic phase by concentrating forces at the liquid / liquid interface rather than imparting energy to the bulk solution as is done in impeller-based reactors. Characterization of emulsion quality and determination of rates of DBT oxidation to 2- hydroxybiphenyl (2-HBP) were performed for both batch stirred reactors (BSR) and the EPC. The EPC was capable of producing aqueous droplets of about 5 {micro}m in diameter using 3 W/L whereas the impeller-based reactor formed droplets between 100 and 200 {micro}m with comparable power consumption. The presence of electric fields was not found to adversely affect biocatalytic activity. Despite the greater surface area for reaction afforded by the EPC, rates of DBT oxidation in both reactors were similar, demonstrating that the biocatalyst used (Rhodococcus sp. IGTS8) was not active enough to be mass transport limited. The EPC is expected to have tremendous impact upon reactor operating costs and biocatalyst utilization once advances biocatalyst development provide systems that are mass transport limited.

  20. Selective cleavage of the two CS bonds in asymmetrically alkylated dibenzothiophenes by Rhodococcus erythropolis KA2-5-1.

    PubMed

    Onaka, T; Kobayashi, M; Ishii, Y; Konishi, J; Maruhashi, K

    2001-01-01

    The Rhodococcus erythropolis strain KA2-5-1 was characterized by its ability to cleave carbon-sulfur bonds in the dibenzothiophene (DBT) ring by asymmetrically alkyl substitution, such as C2-DBTs (e.g., dimethyl and ethyl DBTs) and C3-DBTs (e.g., trimethyl and propyl DBTs), which are known to remain in hydrodesulfurization-treated diesel fuels. After treatment by solid-phase extraction (SPE) of solvents from microbial reactions of alkylated DBTs (Cx-DBTs), we used gas chromatography (GC), GC-atomic emission detection, GC-mass spectrometry and 1H nuclear magnetic resonance spectroscopy to identify and quantitatively evaluate the Cx-DBT metabolites. Molar ratios of metabolic isomers of the desulfurization products suggested that resting-cell reactions of KA2-5-1 against these Cx-DBTs occurrs through specific carbon-sulfur-bond-targeted cleavages, yielding alkylated hydroxybiphenyls, and that the manner of the attack on the DBT skeleton is affected not only by the position but also by the number and length of the alkyl substituents. PMID:16233063

  1. Analysis of Bacterial Community Structure in Sulfurous-Oil-Containing Soils and Detection of Species Carrying Dibenzothiophene Desulfurization (dsz) Genes

    PubMed Central

    Duarte, Gabriela Frois; Rosado, Alexandre Soares; Seldin, Lucy; de Araujo, Welington; van Elsas, Jan Dirk

    2001-01-01

    The selective effects of sulfur-containing hydrocarbons, with respect to changes in bacterial community structure and selection of desulfurizing organisms and genes, were studied in soil. Samples taken from a polluted field soil (A) along a concentration gradient of sulfurous oil and from soil microcosms treated with dibenzothiophene (DBT)-containing petroleum (FSL soil) were analyzed. Analyses included plate counts of total bacteria and of DBT utilizers, molecular community profiling via soil DNA-based PCR-denaturing gradient gel electrophoresis (PCR-DGGE), and detection of genes that encode enzymes involved in the desulfurization of hydrocarbons, i.e., dszA, dszB, and dszC.Data obtained from the A soil showed no discriminating effects of oil levels on the culturable bacterial numbers on either medium used. Generally, counts of DBT degraders were 10- to 100-fold lower than the total culturable counts. However, PCR-DGGE showed that the numbers of bands detected in the molecular community profiles decreased with increasing oil content of the soil. Analysis of the sequences of three prominent bands of the profiles generated with the highly polluted soil samples suggested that the underlying organisms were related to Actinomyces sp., Arthrobacter sp., and a bacterium of uncertain affiliation. dszA, dszB, and dszC genes were present in all A soil samples, whereas a range of unpolluted soils gave negative results in this analysis. Results from the study of FSL soil revealed minor effects of the petroleum-DBT treatment on culturable bacterial numbers and clear effects on the DBT-utilizing communities. The molecular community profiles were largely stable over time in the untreated soil, whereas they showed a progressive change over time following treatment with DBT-containing petroleum. Direct PCR assessment revealed the presence of dszB-related signals in the untreated FSL soil and the apparent selection of dszA- and dszC-related sequences by the petroleum-DBT treatment

  2. Transdiagnostic Applications of DBT for Adolescents and Adults.

    PubMed

    Ritschel, Lorie A; Lim, Noriel E; Stewart, Lindsay M

    2015-01-01

    Dialectical behavior therapy (DBT) is an empirically supported treatment that was originally developed for chronically suicidal adults. Since the publication of the original treatment manual, DBT has been reconceptualized as a treatment that is broadly applicable for individuals who have difficulties regulating emotion. As such, the treatment can be applied transdiagnostically. Based on the flexibility and adaptability of the treatment, several adaptations have been made to the original protocol. Considerable empirical evidence now supports the use of DBT adapted for eating disorders, substance use disorders, and posttraumatic stress disorder. Moreover, developmentally appropriate adaptations have made the treatment applicable to youth samples. The current paper is geared toward practitioners and describes the various ways in which DBT has been modified for use with various populations and age ranges. PMID:26160618

  3. Influence of DBT reconstruction algorithm on power law spectrum coefficient

    NASA Astrophysics Data System (ADS)

    Vancamberg, Laurence; Carton, Ann-Katherine; Abderrahmane, Ilyes H.; Palma, Giovanni; Milioni de Carvalho, Pablo; Iordache, Rǎzvan; Muller, Serge

    2015-03-01

    In breast X-ray images, texture has been characterized by a noise power spectrum (NPS) that has an inverse power-law shape described by its slope β in the log-log domain. It has been suggested that the magnitude of the power-law spectrum coefficient β is related to mass lesion detection performance. We assessed β in reconstructed digital breast tomosynthesis (DBT) images to evaluate its sensitivity to different typical reconstruction algorithms including simple back projection (SBP), filtered back projection (FBP) and a simultaneous iterative reconstruction algorithm (SIRT 30 iterations). Results were further compared to the β coefficient estimated from 2D central DBT projections. The calculations were performed on 31 unilateral clinical DBT data sets and simulated DBT images from 31 anthropomorphic software breast phantoms. Our results show that β highly depends on the reconstruction algorithm; the highest β values were found for SBP, followed by reconstruction with FBP, while the lowest β values were found for SIRT. In contrast to previous studies, we found that β is not always lower in reconstructed DBT slices, compared to 2D projections and this depends on the reconstruction algorithm. All β values estimated in DBT slices reconstructed with SBP were larger than β values from 2D central projections. Our study also shows that the reconstruction algorithm affects the symmetry of the breast texture NPS; the NPS of clinical cases reconstructed with SBP exhibit the highest symmetry, while the NPS of cases reconstructed with SIRT exhibit the highest asymmetry.

  4. PFO-DBT:MEH-PPV:PC71BM Ternary Blend Assisted Platform as a Photodetector

    PubMed Central

    Zafar, Qayyum; Ahmad, Zubair; Sulaiman, Khaulah

    2015-01-01

    We present a ternary blend-based bulk heterojunction ITO/PEDOT:PSS/PFO-DBT:MEH-PPV:PC71BM/LiF/Al photodetector. Enhanced optical absorption range of the active film has been achieved by blending two donor components viz. poly[2,7-(9,9-di-octyl-fluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PFO-DBT) and poly(2-methoxy-5(2′-ethylhexyloxy) phenylenevinylene (MEH-PPV) along with an acceptor component, i.e., (6,6)-phenyl-C71 hexnoic acid methyl ester. The dependency of the generation rate of free charge carriers in the organic photodetector (OPD) on varied incident optical power density was investigated as a function of different reverse biasing voltages. The photocurrent showed significant enhancement as the intensity of light impinging on active area of OPD is increased. The ratio of Ilight to Idark of fabricated device at −3 V was ∼3.5 × 104. The dynamic behaviour of the OPD under on/off switching irradiation revealed that sensor exhibits quick response and recovery time of <800 ms and 500 ms, respectively. Besides reliability and repeatability in the photoresponse characteristics, the cost-effective and eco-friendly fabrication is the added benefit of the fabricated OPD. PMID:25574936

  5. Selectivity of molybdenum catalyst in hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation: effect of additives on dibenzothiophene hydrodesulfurization

    SciTech Connect

    Nagai, M.; Kabe, T.

    1983-06-01

    Kinetic studies of the hydrodesulfurization of dibenzothiophene on a presulfided molybdena-alumina catalyst were carried out in a high-pressure-flow microreactor. The mechanism discussed is based on selective poisoning studies, using various nitrogen, polyaromatic, sulfur, and oxygen compounds. The nitrogen compounds inhibited the hydrogenation of dibenzothiophene because they adsorbed more strongly than did dibenzothiophene at lower temperatures. At higher temperatures, the nitrogen compounds also hinder the desulfurization together with the hydrogenation of dibenzothiophene. The sulfur and the oxygen compounds retarded all reactions of the desulfurization of dibenzothiophene. The reactions of the desulfurization, the denitrogenation, and the deoxygenation proceed on one type of site and the hydrogenation reactions on another site. 10 figures.

  6. ICMR-DBT Guidelines for Evaluation of Probiotics in Food

    PubMed Central

    Ganguly, N.K.; Bhattacharya, S.K.; Sesikeran, B.; Nair, G.B; Ramakrishna, B.S.; Sachdev, H.P.S.; Batish, V.K.; Kanagasabapathy, A.S.; Muthuswamy, Vasantha; Kathuria, S.C; Katoch, V.M.; Satyanarayana, K.; Toteja, G.S; Rahi, Manju; Rao, Spriha; Bhan, M.K; Kapur, Rajesh; Hemalatha, R

    2011-01-01

    There has been an increased influx of probiotic products in the Indian market during the last decade. However, there has been no systematic approach for evaluation of probiotics in food to ensure their safety and efficacy. An initiative was, therefore, taken by the Indian Council of Medical Research (ICMR) along with the Department of Biotechnology (DBT) to formulate guidelines for regulation of probiotic products in the country. These guidelines define a set of parameters required for a product/strain to be termed as ‘probiotic’. These include identification of the strain, in vitro screening for probiotic characteristics, animal studies to establish safety and in vivo animal and human studies to establish efficacy. The guidelines also include requirements for labeling of the probiotic products with strain specification, viable numbers at the end of shelf life, storage conditions, etc., which would be helpful to the consumers to safeguard their own interest. PMID:21808130

  7. Piloting a Dialectical Behavioral Therapy (DBT) Infused Skills Group in a Disciplinary Alternative Education Program (DAEP)

    ERIC Educational Resources Information Center

    Ricard, Richard J.; Lerma, Eunice; Heard, Courtney C. C.

    2013-01-01

    This study explored the impact of a 4-week skills group intervention based on the principles of Dialectical Behavior Therapy (DBT) with a sample of adolescents attending a Disciplinary Alternative Education Program. This article provides a session-by-session overview of activities adapted from DBT-specified training modules of mindfulness,…

  8. DBT-Enhanced Cognitive Behavioral Therapy for Adolescent Trichotillomania: An Adolescent Case Study

    ERIC Educational Resources Information Center

    Welch, Stacy Shaw; Kim, Junny

    2012-01-01

    Results and a case study for a DBT-enhanced habit reversal treatment (HRT) for adult trichotillomania (TTM) (Keuthen & Sprich, 2012) is adapted for use with adolescents. Trichotillomania in adolescence is a very important but understudied problem. Onset often occurs in adolescence, and yet very little treatment research exists. DBT-enhanced habit…

  9. Comparison of computerized mass detection in digital breast tomosynthesis (DBT) mammograms and conventional mammograms

    NASA Astrophysics Data System (ADS)

    Chan, Heang-Ping; Wei, Jun; Sahiner, Berkman; Hadjiiski, Lubomir; Helvie, Mark A.

    2009-02-01

    We are developing a CAD system for mass detection on digital breast tomosynthesis (DBT) mammograms. In this study, we compared the detection accuracy on DBT and conventional screen-film mammograms (SFMs). DBT mammograms were acquired with a GE prototype system at the University of Michigan. 47 cases containing the CC- and MLO-view DBT mammograms of the breast with a biopsy-proven mass and the corresponding two-view SFMs of the same breast were collected. Subjective judgment showed that the masses were much more conspicuous on DBT slices than on SFMs. The CAD system for DBT includes two parallel processes, one performs mass detection in the reconstructed DBT volume, and the other in the projection view (PV) images. The mass likelihood scores estimated for each mass candidate in the two processes are merged to differentiate masses and false positives (FPs). For detection on SFMs, we previously developed a dual system approach by fusing two single CAD systems optimized for detection of average and subtle masses, respectively. A trained neural network is used to merge the mass likelihood scores of the two single systems to reduce FPs. At the case-based sensitivities of 80% and 85%, mass detection in the DBT volume resulted in an average of 0.72 and 1.06 FPs/view, and detection in the SFMs yielded 0.94 and 1.67 FPs/view, respectively. The difference fell short of statistical significance (p=0.07) by JAFROC analysis. Study is underway to collect a larger data set and to further improve the DBT CAD system.

  10. Digital breast tomosynthesis (DBT): a review of the evidence for use as a screening tool.

    PubMed

    Gilbert, Fiona J; Tucker, Lorraine; Young, Ken C

    2016-02-01

    Breast screening with full-field digital mammography (FFDM) fails to detect 15-30% of cancers. This figure is higher for women with dense breasts. A new tomographic technique in mammography has been developed--digital breast tomosynthesis (DBT)--which allows images to be viewed in sections through the breast and has the potential to improve cancer detection rates. Results from retrospective reading studies comparing DBT with FFDM have been largely favourable with improvement in sensitivity and specificity. Increases in diagnostic accuracy have been reported as being independent of breast density; however there are mixed reports regarding the detection of microcalcification. Prospective screening studies using DBT with FFDM have demonstrated increased rates in cancer detection compared with FFDM alone. A reduction in false-positive recall rates has also been shown. Screening with the addition of DBT would approximately double radiation dose; however a simulated FFDM image can be generated from a DBT scan. The combination of simulated FFDM images and DBT is being evaluated within several studies and some positive results have been published. Interval cancer rates for the UK National Health Service Breast Screening Programme (NHSBSP) demonstrate the limited sensitivity of FFDM in cancer detection. DBT has the potential to increase sensitivity and decrease false-positive recall rates. It has approval for screening and diagnostics in several countries; however, there are issues with DBT as a screening tool including additional reading time, IT storage and connectivity, over-diagnosis, and cost effectiveness. Feasibility and cost-effectiveness trials are needed before the implementation of DBT in NHSBSP can be considered. PMID:26707815

  11. Mechanism of hydrodesulfurization of dibenzothiophene on Co-Mo/Al[sub 2]O[sub 3] and Co/Al[sub 2]O[sub 3] catalyst by the use of radioisotope [sup 35]S tracer

    SciTech Connect

    Kabe, T.; Qian, W.; Ogawa, S.; Ishihara, A. )

    1993-09-01

    In order to estimate the behavior of sulfur on hydrodesulfurization catalyst, the [sup 35]S-labelled dibenzothiophene ([sup 35]S-DBT) was hydrodesulfurized on sulfided Co-Mo/Al[sub 2]O[sub 3] and Co/Al[sub 2]O[sub 3] in a fixed-bed pressurized flow reactor. During the reaction, the radioactivities of unreacted [sup 35]S-DBT and formed [sup 35]S-H[sub 2]S were monitored. The rate of the release of sulfur on the catalyst was estimated from the rates of an increase and a decrease of the radioactivity in formed [sup 35]S-H[sub 2]S. The activation energies of the release of sulfur were 3.7 and 9.9 kcal/mol for sulfided Co-Mo/Al[sub 2]O[sub 3] and Co/Al[sub 2]O[sub 3], respectively. The amount of labile sulfur (S[sub 0]), which could be calculated from the maximum amount of [sup 35]S accomodated on the catalyst, increased with increasing temperature. When it was assumed that sulfur in sulfided Co-Mo/Al[sub 2]O[sub 3] existed in the form of Co[sub 9]S[sub 8]-MoS[sub 2]/Al[sub 2]O[sub 3], the ratio of labile sulfur to total sulfur did not exceed 50%, even under conditions where the rate of DBT HDS is relatively high. On the contrary, the ratio of labile sulfur to total sulfur for Co/Al[sub 2]O[sub 3] exceeded 80%. 34 refs., 7 figs., 2 tabs.

  12. Investigation of the potential of Sulfolobus acidocaldarius to transform dibenzothiophene: Final report

    SciTech Connect

    Krawiec, S.; Montenecourt, B.S.

    1986-12-31

    Archaebacteria including S. acidocaldarius appear genetically unstable and while some cultures of S. acidocaldarius may have the capacity to transform DBT the results remain unclear. A legitimate interpretation from the observations presented in this Report is that the phenotypic character of S. acidocaldarius changed during the course of the project. Because the environment in which the organism was subcultured was constant, the differences in phenotype would appear to be genetic. Culturing in the presence of 2% pristane plus DBT may be a sufficiently powerful form of selection to account for the apparent shift from DBT-sensitivity to DBT-adaptation and then from DBT-adaptation to DBT-resistance. However, any genetic change might be enhanced by an astonishing hypervariability which may possess uniquely archaebacterial features. The evidence for hypermutability comes largely from the Halobacteria. Any desulfurization process involving an Archaebacterium should include explicit means of maintaining and demonstrating the phenotypic stability of the organism which mediates the desired process. The possibility that S. acidocaldarius can degrade DBT remains tentative. 24 refs., 22 figs., 5 tabs.

  13. High dynamic range CMOS-based mammography detector for FFDM and DBT

    NASA Astrophysics Data System (ADS)

    Peters, Inge M.; Smit, Chiel; Miller, James J.; Lomako, Andrey

    2016-03-01

    Digital Breast Tomosynthesis (DBT) requires excellent image quality in a dynamic mode at very low dose levels while Full Field Digital Mammography (FFDM) is a static imaging modality that requires high saturation dose levels. These opposing requirements can only be met by a dynamic detector with a high dynamic range. This paper will discuss a wafer-scale CMOS-based mammography detector with 49.5 μm pixels and a CsI scintillator. Excellent image quality is obtained for FFDM as well as DBT applications, comparing favorably with a-Se detectors that dominate the X-ray mammography market today. The typical dynamic range of a mammography detector is not high enough to accommodate both the low noise and the high saturation dose requirements for DBT and FFDM applications, respectively. An approach based on gain switching does not provide the signal-to-noise benefits in the low-dose DBT conditions. The solution to this is to add frame summing functionality to the detector. In one X-ray pulse several image frames will be acquired and summed. The requirements to implement this into a detector are low noise levels, high frame rates and low lag performance, all of which are unique characteristics of CMOS detectors. Results are presented to prove that excellent image quality is achieved, using a single detector for both DBT as well as FFDM dose conditions. This method of frame summing gave the opportunity to optimize the detector noise and saturation level for DBT applications, to achieve high DQE level at low dose, without compromising the FFDM performance.

  14. Confirmation of iPTF13dbt as a Classical Nova in M31

    NASA Astrophysics Data System (ADS)

    Tang, S.; Cao, Y.; Kasliwal, M. M.; Waszczak, A.; Johansson, J.; O'Sullivan, D.; Ben-Ami, S.

    2013-09-01

    iPTF13dbt (00:44:01.52, +41:32:01.3) is a nova in M31 recently discovered by iPTF (ATel #5341; see also ATel #5349, #5350 for ASAS-SN detections). We obtained a spectrum of iPTF13dbt with the Double Spectrograph on the Palomar 200-inch Telescope on Sep 4, 2013, 06:48 UT. It shows strong emission lines, including Balmer series, O I 7773, O I 8446, O I 9264, He I 6678, and Fe II bands between 4900A and 5500A.

  15. What must you know and do to get good outcomes with DBT?

    PubMed

    Koerner, Kelly

    2013-12-01

    Because little research has been conducted on which therapist-client interactions lead to intermediate and end-point improvements in Dialectical Behavior Therapy (DBT), we have a small evidence-base from which to specify what therapists must know and do in order to obtain good outcomes using DBT. As with other evidence-based practices, dissemination of DBT has defaulted to assumptions and methods from the "psychotherapy technology model," which emphasizes transfer of the validated treatment package from the research clinic to routine settings with high fidelity (Morgenstern & McKay, 2007). However, serious limitations of the psychotherapy technology model require pursuit of alternative complementary models to guide dissemination. One complementary approach is to use well-designed practice-based training research. In this approach, therapists learn modular competencies linked to a highly structured yet flexible clinical decision-making framework. Modular training of therapist competencies emphasizes the continuity of the component therapist strategies across evidence-based protocols rather than emphasizing the packages or manuals as separate and distinct. Key hypotheses about the change processes responsible for client change and the associated treatment strategies used to influence these change processes should be specified and measured at the level of client, therapist, and service delivery setting. Adopting this approach may offer advantages that apply to the dissemination and implementation of DBT and other evidence-based practices (EBPs). PMID:24094782

  16. Dialectical Behavior Therapy (DBT) Applied to College Students: A Randomized Clinical Trial

    ERIC Educational Resources Information Center

    Pistorello, Jacqueline; Fruzzetti, Alan E.; MacLane, Chelsea; Gallop, Robert; Iverson, Katherine M.

    2012-01-01

    Objective: College counseling centers (CCCs) are increasingly being called upon to treat highly distressed students with complex clinical presentations. This study compared the effectiveness of Dialectical Behavior Therapy (DBT) for suicidal college students with an optimized control condition and analyzed baseline global functioning as a…

  17. A DBT Skills Training Group for Family Caregivers of Persons with Dementia

    ERIC Educational Resources Information Center

    Drossel, Claudia; Fisher, Jane E.; Mercer, Victoria

    2011-01-01

    A Dialectical Behavior Therapy Skills training manual (DBT Skills) was adapted for use with caregivers of individuals with dementia. Implementation occurred in a community clinic with a heterogeneous caregiver group at risk for elder abuse. Sixteen caregivers completed the 9-week group. The results point to improved psychosocial adjustment,…

  18. Meta-Analysis and Systematic Review Assessing the Efficacy of Dialectical Behavior Therapy (DBT)

    ERIC Educational Resources Information Center

    Panos, Patrick T.; Jackson, John W.; Hasan, Omar; Panos, Angelea

    2014-01-01

    Objective: The objective was to quantitatively and qualitatively examine the efficacy of DBT (e.g., decreasing life-threatening suicidal and parasuicidal acts, attrition, and depression) explicitly with borderline personality disorder (BPD) and using conservative assumptions and criteria, across treatment providers and settings. Method: Five…

  19. Utilizing DBT Skills to Augment Traditional CBT for Trichotillomania: An Adult Case Study

    ERIC Educational Resources Information Center

    Keuthen, Nancy J.; Sprich, Susan E.

    2012-01-01

    Traditional cognitive-behavioral interventions for trichotillomania have had modest acute treatment outcomes and poor maintenance of gains over time. Techniques adopted from dialectical behavior therapy (DBT) can potentially enhance treatment outcomes by specifically addressing issues of impulsivity, emotion regulation, and distress tolerance. In…

  20. Image reconstruction for digital breast tomosynthesis (DBT) by using projection-angle-dependent filter functions

    NASA Astrophysics Data System (ADS)

    Park, Yeonok; Park, Chulkyu; Cho, Hyosung; Je, Uikyu; Hong, Daeki; Lee, Minsik; Cho, Heemoon; Choi, Sungil; Koo, Yangseo

    2014-09-01

    Digital breast tomosynthesis (DBT) is considered in clinics as a standard three-dimensional imaging modality, allowing the earlier detection of cancer. It typically acquires only 10-30 projections over a limited angle range of 15-60° with a stationary detector and typically uses a computationally-efficient filtered-backprojection (FBP) algorithm for image reconstruction. However, a common FBP algorithm yields poor image quality resulting from the loss of average image value and the presence of severe image artifacts due to the elimination of the dc component of the image by the ramp filter and to the incomplete data, respectively. As an alternative, iterative reconstruction methods are often used in DBT to overcome these difficulties, even though they are still computationally expensive. In this study, as a compromise, we considered a projection-angle-dependent filtering method in which one-dimensional geometry-adapted filter kernels are computed with the aid of a conjugate-gradient method and are incorporated into the standard FBP framework. We implemented the proposed algorithm and performed systematic simulation works to investigate the imaging characteristics. Our results indicate that the proposed method is superior to a conventional FBP method for DBT imaging and has a comparable computational cost, while preserving good image homogeneity and edge sharpening with no serious image artifacts.

  1. Psychotherapy of Borderline Personality Disorder: Can the Supply Meet the Demand? A German Nationwide Survey in DBT Inpatient and Day Clinic Treatment Facilities.

    PubMed

    Richter, Christoph; Steinacher, Bruno; zum Eschenhoff, Anna; Bermpohl, Felix

    2016-02-01

    The present study aimed to assess (1) the amount of inpatient and day clinic DBT treatment places for patients with borderline personality disorder and (2) the relationship between supply and demand in a given study region. Survey of inpatient and day clinic facilities in the German DBT network. 42 inpatient units and day clinics responded, representing 75 % of the DBT network members contacted. These institutions offer 527 DBT treatment places and treat about 2310 patients per year. The mean waiting period prior to treatment was 14.3 weeks. 700 DBT inpatient or day clinic places exist in Germany in 2011. 3000 patients receive DBT inpatient or day clinic treatment per year. This approximates a ratio of 820 borderline patients for one existing DBT inpatient or day clinic place in Germany. The long waiting time reflects the great demand for this treatment and could be interpreted as an imbalance between supply and demand. PMID:26323785

  2. Effects of projection-view distributions on image quality of calcifications in digital breast tomosynthesis (DBT) reconstruction

    NASA Astrophysics Data System (ADS)

    Lu, Yao; Chan, Heang-Ping; Goodsitt, Mitch; Wei, Jun; Hadjiiski, Lubomir; Schmitz, Andrea; Eberhard, Jeffrey W.; Claus, Bernhard E. H.

    2010-04-01

    We are investigating factors affecting the detection of microcalcifications in digital breast tomography (DBT). In this study, we analyzed the effects of projection-view (PV) distribution on spatial blurring of calcifications on the tomosynthesized slices (X-Y plane) and along the depth (Z) direction. DBT scans of a breast phantom with simulated microcalcifications were acquired with a GE prototype system at 21 angles in 3° increments over a +/-30° range. Six subsets of 11 PVs were selected from the full set to simulate DBT of different angular ranges and angular increments. SART was applied to each subset to reconstruct the DBT slices. The FWHMs of the line profiles of calcifications within their in-focus DBT slices and FWHMs of the inter-plane artifact spread function (ASF) in the Z-direction for the different PV distributions were compared. The results indicate that DBT acquired with a large angular range or a reasonable number of PVs at large angles yield superior ASF with smaller FWHM in the Z-direction. PV distributions with a narrow angular range have stronger inter-plane artifacts. In the X-Y focal planes, the effect of PV distributions on spatial blurring depends on the directions. The normalized line profiles of the calcifications reconstructed with the different PV distributions are similar in the X-direction. The differences in the FWHMs between the different PV distributions are less than half a pixel. In the Y-(x-ray tube motion) direction, the normalized line profiles of the calcifications reconstructed with DBT acquired with a narrow angular range or a reasonable number of PVs at small angles have less blurring in terms of smaller FWHMs of the line profiles. PV distributions with a wide angular range have stronger in-plane artifacts in the Y-direction. Further study is underway to compare different reconstruction techniques and parameters. The information will be useful for optimization of DBT for detection of microcalcifications.

  3. Study of hydrosulfurization of dibenzothiophene on Ni-Mo/Al{sub 2}O{sub 3}, Mo/Al{sub 2}O{sub 3}, and Ni/Al{sub 2}O{sub 3} catalysts by the use of radioisotope {sup 35}S tracer

    SciTech Connect

    Kabe, Toshiaki; Qian, Weihua; Ishihara, Atsushi

    1994-09-01

    The radioisotope tracer method has been used to quantify the behavior of sulfur on sulfided Ni-Mo/Al{sub 2}O{sub 3}, Mo/Al{sub 2}O{sub 3}, and Ni/Al{sub 2}O{sub 3}. The apparent activation energies of HDS reaction for DBT for the three catalysts were 20{+-}1 kcal/mol. The formation rate constants of {sup 35}S-H{sub 2}S were determined and the amount of labile sulfur on the sulfided catalysts were estimated by tracing the changes in radioactivities of the unreacted {sup 35}S-DBT and the formed {sup 35}S-H{sub 2}S during the HDS reaction of {sup 35}S-labeled dibenzothiophene ({sup 35}S-DBT). It was deduced that ca. 75% of sulfur in the sulfided Mo/Al{sub 2}O{sub 3} was related to HDS reaction at infinite rate of HDS. Compared with the amounts of labile sulfur in the sulfided Ni-Mo/Al{sub 2}O{sub 3}, Mo/Al{sub 2}O{sub 3}, and Ni/Al{sub 2}O{sub 3}, it was determined that the amounts of labile sulfur were 1.6, 9.8, and 18.4 mg sulfur/g catalyst at 280{degrees}C for the three catalysts, respectively. It was suggested that the sulfur in the form of NiS on the sulfided Ni-Mo/Al{sub 2}O{sub 3} was not labile and that the sulfur attached to both Mo and Ni atom were more labile and related to HDS. The promotion of Ni for Mo-based catalysts was attributed to the sulfur bonded to both Mo and Ni in the MoS{sub 2} phase being more labile. 35 refs., 12 figs., 2 tabs.

  4. Benzo[b]naphthothiophenes and alkyl dibenzothiophenes: molecular tracers for oil migration distances

    USGS Publications Warehouse

    Li, Meijun; Wang, T.-G.; Shi, Shengbao; Liu, Keyu; Ellis, Geoffrey S.

    2014-01-01

    The secondary migration of petroleum is one of the most critical geological processes responsible for the accumulation of hydrocarbons in a sedimentary basin. Pyrrolic nitrogen compounds such as carbazoles and benzocarbazoles are thought to be practical molecular indicators for estimating relative migration distances of oil. In light oils or condensates, however, considerable analytical errors are usually caused by low concentrations of NSO-compounds. Here we show that polycyclic sulfur aromatic hydrocarbons such as dibenzothiophene, C1∼C3 alkylated dibenzothiophenes and benzo[b]naphthothiophenes, which are present in relatively higher concentrations than the pyrrolic nitrogen compounds, exhibit changes in both absolute and relative concentrations that correlate with migration distances. The polycyclic sulfur aromatic hydrocarbons related parameters — benzo[b]naphtho[2,1-d]thiophene/{benzo[b]naphtho[2,1-d]thiophene + benzo[b]naphtho[1,2-d]thiophene} (abbreviated as [2,1]BNT/([2,1]BNT+[1,2]BNT) and the concentration of total dibenzothiophenes plus benzo[b]naphthothiophenes — are proposed by this paper to trace the oil migration distances.

  5. Comparison of model and human observer performance in FFDM, DBT, and synthetic mammography

    NASA Astrophysics Data System (ADS)

    Ikejimba, Lynda; Glick, Stephen J.; Samei, Ehsan; Lo, Joseph Y.

    2016-03-01

    Reader studies are important in assessing breast imaging systems. The purpose of this work was to assess task-based performance of full field digital mammography (FFDM), digital breast tomosynthesis (DBT), and synthetic mammography (SM) using different phantom types, and to determine an accurate observer model for human readers. Images were acquired on a Hologic Selenia Dimensions system with a uniform and anthropomorphic phantom. A contrast detail insert of small, low-contrast disks was created using an inkjet printer with iodine-doped ink and inserted in the phantoms. The disks varied in diameter from 210 to 630 μm, and in contrast from 1.1% contrast to 2.2% in regular increments. Human and model observers performed a 4-alternative forced choice experiment. The models were a non-prewhitening matched filter with eye model (NPWE) and a channelized Hotelling observer with either Gabor channels (Gabor-CHO) or Laguerre-Gauss channels (LG-CHO). With the given phantoms, reader scores were higher in FFDM and DBT than SM. The structure in the phantom background had a bigger impact on outcome for DBT than for FFDM or SM. All three model observers showed good correlation with humans in the uniform background, with ρ between 0.89 and 0.93. However, in the structured background, only the CHOs had high correlation, with ρ=0.92 for Gabor-CHO, 0.90 for LG-CHO, and 0.77 for NPWE. Because results of any analysis can depend on the phantom structure, conclusions of modality performance may need to be taken in the context of an appropriate model observer and a realistic phantom.

  6. Compatibility tests between Jarytherm DBT synthetic oil and solid materials from wastes

    NASA Astrophysics Data System (ADS)

    Fasquelle, Thomas; Falcoz, Quentin; Neveu, Pierre; Flamant, Gilles; Walker, Jérémie

    2016-05-01

    Direct thermocline thermal energy storage is the cheapest sensible thermal energy storage configuration. Indeed, a thermocline tank consists in one tank instead of two and reduces costs. Thermocline thermal energy storages are often filled with cheap solid materials which could react with the heat transfer fluid in the case of incompatibility. PROMES laboratory is building a pilot-scale parabolic trough solar loop including a direct thermocline thermal energy storage system. The working fluid will be a synthetic oil, the Jarytherm® DBT, and the thermal energy storage tank will be filled with stabilized solid materials elaborated from vitrified wastes. Compatibility tests have been conducted in order to check on one hand if the thermo-mechanical properties and life time of the energy storage medium are not affected by the contact with oil and, on the other hand, if the thermal oil performances are not degraded by the solid filler. These experiments consisted in putting in contact the oil and the solid materials in small tanks. In order to discriminate the solid materials tested in the shortest time, accelerating aging conditions at 330 °C for 500 hours were used. The measurements consisted in X-Ray Diffraction and Scanning Electron Microscopy for the solids, and thermo-physical and chemical properties measurements for the oil. Regarding the solid samples, their crystalline structure did not change during the test, but it is difficult to conclude about their elementary composition and they seem to absorb oil. While thermal properties still makes Jarytherm® DBT a good heat transfer fluid after the accelerated aging tests, this study results in differentiating most compatible materials. Thus according to our study, Jarytherm® DBT can be used in direct thermocline thermal energy storage applications when compatibility of the solid material has been demonstrated.

  7. Refractory depression: mechanisms and evaluation of radically open dialectical behaviour therapy (RO-DBT) [REFRAMED]: protocol for randomised trial

    PubMed Central

    Lynch, T R; Whalley, B; Hempel, R J; Byford, S; Clarke, P; Clarke, S; Kingdon, D; O'Mahen, H; Russell, I T; Shearer, J; Stanton, M; Swales, M; Watkins, A; Remington, B

    2015-01-01

    Introduction Only 30–40% of depressed patients treated with medication achieve full remission. Studies that change medication or augment it by psychotherapy achieve only limited benefits, in part because current treatments are not designed for chronic and complex patients. Previous trials have excluded high-risk patients and those with comorbid personality disorder. Radically Open Dialectical Behaviour Therapy (RO-DBT) is a novel, transdiagnostic treatment for disorders of emotional over-control. The REFRAMED trial aims to evaluate the effectiveness and cost-effectiveness of RO-DBT for patients with treatment-resistant depression. Methods and analysis REFRAMED is a multicentre randomised controlled trial, comparing 7 months of individual and group RO-DBT treatment with treatment as usual (TAU). Our primary outcome measure is depressive symptoms 12 months after randomisation. We shall estimate the cost-effectiveness of RO-DBT by cost per quality-adjusted life year. Causal analyses will explore the mechanisms by which RO-DBT is effective. Ethics and dissemination The National Research Ethics Service (NRES) Committee South Central – Southampton A first granted ethical approval on 20 June 2011, reference number 11/SC/0146. Trial registration number ISRCTN85784627. PMID:26187121

  8. Computer-aided detection of microcalcifications in digital breast tomosynthesis (DBT): a multichannel signal detection approach on projection views

    NASA Astrophysics Data System (ADS)

    Wei, Jun; Chan, Heang-Ping; Hadjiiski, Lubomir; Helvie, Mark A.; Zhou, Chuan; Lu, Yao

    2012-03-01

    DBT is one of the promising imaging modalities that may improve the sensitivity and specificity for breast cancer detection. We are developing a computer-aided detection (CADe) system for clustered microcalcifications (MC) in DBT. A data set of two-view DBTs from 42 breasts was collected with a GE prototype system. We investigated a 2D approach to MC detection using projection view (PV) images rather than reconstructed 3D DBT volume. Our 2D approach consisted of two major stages: 1) detecting individual MC candidates on each PV, and 2) correlating the MC candidates from the different PVs and detecting clusters in the breast volume. With the MC candidates detected by prescreening on PVs, a trained multi-channel (MCH) filter bank was used to extract signal response from each MC candidate. A ray-tracing process was performed to fuse the MCH responses and localize the MC candidates in 3D using the geometrical information of the DBT system. Potential MC clusters were then identified by dynamic clustering of the MCs in 3D. A two-fold cross-validation method was used to train and test the CADe system. The detection performance of clustered MCs was assessed by free receiver operating characteristic (FROC) analysis. It was found that the CADe system achieved a case-based sensitivity of 90% at an average false positive rate of 2.1 clusters per DBT volume. Our study demonstrated that the CADe system using 2D MCH filter bank is promising for detection of clustered MCs in DBT.

  9. Impact of a Dialectic Behavior Therapy - Corrections Modified (DBT-CM) Upon Behaviorally Challenged Incarcerated Male Adolescents

    PubMed Central

    Shelton, Deborah; Kesten, Karen; Zhang, Wanli; Trestman, Robert

    2011-01-01

    Purpose This article reports the findings of a Dialectical Behavioral Therapy- Corrections Modified (DBT-CM) intervention upon difficult to manage, impulsive and/or aggressive incarcerated male adolescents. Methods A secondary analysis of a sub-sample of 38 male adolescents who participated in the study was conducted. A one-group pretest-posttest design was used; descriptive statistics and t-tests were conducted. Results Significant changes were found in physical aggression, distancing coping methods and number of disciplinary tickets for behavior. Conclusion The study supports the value of DBT-CM for management of incarcerated male adolescents with difficult to manage aggressive behaviors. PMID:21501287

  10. A Pilot Study of the DBT Coach: An Interactive Mobile Phone Application for Individuals with Borderline Personality Disorder and Substance Use Disorder

    ERIC Educational Resources Information Center

    Rizvi, Shireen L.; Dimeff, Linda A.; Skutch, Julie; Carroll, David; Linehan, Marsha M.

    2011-01-01

    Dialectical behavior therapy (DBT) has received strong empirical support and is practiced widely as a treatment for borderline personality disorder (BPD) and BPD with comorbid substance use disorders (BPD-SUD). Therapeutic success in DBT requires that individuals generalize newly acquired skills to their natural environment. However, there have…

  11. DBT Telephone Skills Coaching with Eating Disordered Clients: Who Calls, for What Reasons, and for How Long?

    ERIC Educational Resources Information Center

    Limbrunner, Heidi M.; Ben-Porath, Denise D.; Wisniewski, Lucene

    2011-01-01

    The goal of this paper is to report on the typology, frequency, and duration of intersession calls placed by outpatient eating disorder clients to their therapists. Participants were 17 women, offered DBT after-hours telephone coaching adapted for individuals with eating disorders. Results indicated that clients used telephone coaching primarily…

  12. Mechanistic aspects of the gas-phase coupling of thioanisole and chlorobenzene to dibenzothiophene catalyzed by atomic Ho(+).

    PubMed

    Zhou, Shaodong; Schlangen, Maria; Schwarz, Helmut

    2015-04-14

    Mechanistic aspects of the novel gas-phase generation of dibenzothiophene via coupling of thioanisole and chlorobenzene, employing atomic Ho(+) as a catalyst, have been investigated using Fourier-transform ion cyclotron resonance mass spectrometry in conjunction with density functional theory (DFT) calculations. PMID:25765339

  13. Synthesis of C60-Fused Tetrahydrocarbazole/Dibenzothiophene/Benzothiophene and Dibenzofuran Derivatives via Metal-Free Oxidative Dehydrogenative Carboannulation.

    PubMed

    Liu, Tong-Xin; Ma, Jinliang; Chao, Di; Zhang, Pengling; Ma, Nana; Liu, Qingfeng; Shi, Lei; Zhang, Zhiguo; Zhang, Guisheng

    2016-08-19

    A transition-metal-free oxidative dehydrogenative coupling reaction has been developed for the direct construction of novel C60-fused tetrahydrocarbazoles, dibenzothiophenes, benzothiophenes, and dibenzofurans. This new carboannulation reaction features high atom economy, operational simplicity, broad substrate scope, and excellent functional-group tolerance and provides a convenient access to a scarce class of fullerene derivatives. PMID:27487008

  14. A pilot study of the DBT coach: an interactive mobile phone application for individuals with borderline personality disorder and substance use disorder.

    PubMed

    Rizvi, Shireen L; Dimeff, Linda A; Skutch, Julie; Carroll, David; Linehan, Marsha M

    2011-12-01

    Dialectical behavior therapy (DBT) has received strong empirical support and is practiced widely as a treatment for borderline personality disorder (BPD) and BPD with comorbid substance use disorders (BPD-SUD). Therapeutic success in DBT requires that individuals generalize newly acquired skills to their natural environment. However, there have been only a limited number of options available to achieve this end. The primary goal of this research was to develop and test the feasibility of the DBT Coach, a software application for a smartphone, designed specifically to enhance generalization of a specific DBT skill (opposite action) among individuals with BPD-SUD. We conducted a quasiexperimental study in which 22 individuals who were enrolled in DBT treatment programs received a smartphone with the DBT Coach for 10 to 14 days and were instructed to use it as needed. Participants used the DBT Coach an average of nearly 15 times and gave high ratings of helpfulness and usability. Results indicate that both emotion intensity and urges to use substances significantly decreased within each coaching session. Furthermore, over the trial period, participants reported a decrease in depression and general distress. Mobile technology offering in vivo skills coaching may be a useful tool for reducing urges to use substances and engage in other maladaptive behavior by directly teaching and coaching in alternative, adaptive coping behavior. PMID:22035988

  15. Development and application of a channelized Hotelling observer for DBT optimization on structured background test images with mass simulating targets

    NASA Astrophysics Data System (ADS)

    Petrov, Dimitar; Michielsen, Koen; Cockmartin, Lesley; Zhang, Gouzhi; Young, Kenneth; Marshall, Nicholas; Bosmans, Hilde

    2016-03-01

    Digital breast tomosynthesis (DBT) is a 3D mammography technique that promises better visualization of low contrast lesions than conventional 2D mammography. A wide range of parameters influence the diagnostic information in DBT images and a systematic means of DBT system optimization is needed. The gold standard for image quality assessment is to perform a human observer experiment with experienced readers. Using human observers for optimization is time consuming and not feasible for the large parameter space of DBT. Our goal was to develop a model observer (MO) that can predict human reading performance for standard detection tasks of target objects within a structured phantom and subsequently apply it in a first comparative study. The phantom consists of an acrylic semi-cylindrical container with acrylic spheres of different sizes and the remaining space filled with water. Three types of lesions were included: 3D printed spiculated and non-spiculated mass lesions along with calcification groups. The images of the two mass lesion types were reconstructed with 3 different reconstruction methods (FBP, FBP with SRSAR, MLTRpr) and read by human readers. A Channelized Hotelling model observer was created for the non-spiculated lesion detection task using five Laguerre-Gauss channels, tuned for better performance. For the non-spiculated mass lesions a linear relation between the MO and human observer results was found, with correlation coefficients of 0.956 for standard FBP, 0.998 for FBP with SRSAR and 0.940 for MLTRpr. Both the MO and human observer percentage correct results for the spiculated masses were close to 100%, and showed no difference from each other for every reconstruction algorithm.

  16. [Inpatient Dialectical Behavioral Therapy for Adolescents (DBT-A) - 10 years of experience on the psychiatric inpatient unit "wellenreiter"].

    PubMed

    von Auer, Anne Kristin; Kleindienst, Nikolaus; Ludewig, Sonia; Soyka, Oliver; Bohus, Martin; Ludäscher, Petra

    2015-09-01

    In April 2004 the inpatient unit "Wellenreiter" at the Vorwerker Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy in Lubeck (Germany) opened its doors. Despite reservations by the therapeutic community, we implemented a specialized treatment for female adolescents with symptoms of borderline personality disorder - the I;>ialectical Behavior Therapy for Adolescents (DBT-A). In this article we present the concept, our experiences, and data from the past 10 years of clinical work in this specialized unit. PMID:26373383

  17. Treatment Acceptability Study of Walking The Middle Path, a New DBT Skills Module for Adolescents and their Families.

    PubMed

    Rathus, Jill; Campbell, Bevin; Miller, Alec; Smith, Heather

    2015-01-01

    In light of dialectic behavioral therapy's effectiveness in treating suicidal adults, the treatment has been adapted for use in diverse clinical populations, including adolescents who are suicidal and have multiple problem. Walking the Middle Path is a new skill- training module that addresses specific problems and skill deficits of adolescents and their families. The present study evaluated the acceptability of Walking the Middle Path, in order to establish a basis for further assessment of the module's effectiveness. Fifty participants receiving DBT for adolescent were administered a Treatment Acceptability Scale, a skills-rating scale and an open-ended, qualitative assessment. Results indicated high ratings of acceptability. Middle Path skills ranked highly among the DBT skills perceived as most helpful, with validation rated the most beneficial aspect of skills training. The study provides preliminary support for inclusion of Middle Path in the skills training component of DBT with adolescents and their caregivers. Clinical implications of responses and the role of validation in improving family functioning are discussed. PMID:26160621

  18. Templated growth of PFO-DBT nanorod bundles by spin coating: effect of spin coating rate on the morphological, structural, and optical properties

    PubMed Central

    2014-01-01

    In this study, the spin coating of template-assisted method is used to synthesize poly[2,7-(9,9-dioctylfluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PFO-DBT) nanorod bundles. The morphological, structural, and optical properties of PFO-DBT nanorod bundles are enhanced by varying the spin coating rate (100, 500, and 1,000 rpm) of the common spin coater. The denser morphological distributions of PFO-DBT nanorod bundles are favorably yielded at the low spin coating rate of 100 rpm, while at high spin coating rate, it is shown otherwise. The auspicious morphologies of highly dense PFO-DBT nanorod bundles are supported by the augmented absorption and photoluminescence. PMID:24872806

  19. Eleven novel mutations of the BCKDHA, BCKDHB and DBT genes associated with maple syrup urine disease in the Chinese population: Report on eight cases.

    PubMed

    Li, Xiyuan; Ding, Yuan; Liu, Yupeng; Ma, Yanyan; Song, Jinqing; Wang, Qiao; Li, Mengqiu; Qin, Yaping; Yang, Yanling

    2015-11-01

    Maple syrup urine disease (MSUD) is a rare autosomal recessive disorder that affects the degradation of branched chain amino acids (BCAAs). Only a few cases of MSUD have been documented in Mainland China, and prenatal diagnosis has not been performed so far. In this report, 8 patients (4 girls and 4 boys) with MSUD from 8 unrelated Chinese families were diagnosed at the age of 9 days to 1 year and 8 months. The diagnosis was confirmed by serum BCAAs and genetic analyses. Among the 8 patients, only one was detected by newborn screening. The remaining 7 patients were admitted because of neurological disorders and underwent selective screening. Significantly elevated BCAAs were observed in 7 patients. One patient was diagnosed by post-mortem study. 12 mutations were found in the BCKDHA, BCKDHB and DBT genes. 11 of these mutations were novel: c.178G > T, c.491T > C, c.740A > G, c.1214_1219dupCCAACC and IVS6+1delG in BCKDHA; c.482T > G, c.508C > T, c.767A > G, c.768C > G and IVS4,-2A > C in BCKDHB; and c.1A > G in DBT. Only one mutation, c.659C > T in the BCKDHA gene, had been previously reported. 7 patients were treated by dietary intervention and symptomatic therapy. 6 of them showed clinical improvement. The mother of one patient who died from MSUD underwent amniocentesis during her second pregnancy. The BCAAs level in her amniotic fluid was normal. Only one heterozygous mutation, IVS4,-2A > C in the BCKDHB gene, was detected in the cultured amniocytes. The results revealed that the fetus was not affected by MSUD. Normal development and the blood BCAAs profile confirmed the prenatal diagnosis after birth. Thus, we identified eleven novel mutations associated with MSUD in the Chinese population. Prenatal diagnosis of MSUD was successfully performed on one fetus by genetic analysis of the cultured amniocytes. PMID:26453840

  20. Optical and electroluminescent properties of a number of new derivatives of divinyl dibenzothiophene sulfone

    NASA Astrophysics Data System (ADS)

    Kukhto, A. V.; Kopylova, T. N.; Gadirov, R. M.; Degtyarenko, K. N.; Nikonova, E. N.; Solodova, T. A.; Kukhto, I. N.

    2016-02-01

    Photoluminescent and electroluminescent properties of four new bipolar linear derivatives of divinyl dibenzothiophene sulfone are studied. It is found that amorphous films of solutions, as well as films of the compounds under study in the poly(N-vinylcarbazole) matrix, have a rather high quantum yield of photoluminescence in the blue and blue-green spectrum regions. Bright blue electroluminescence is obtained in the samples with a structure of ITO/PEDOT:PSS/TPD/OC/LiF/Al using vacuum deposition of the compounds under study and in the single-layer ITO/PEDOT:PSS/PVK:OC/LiF/Al structure when applied from the solution with a threshold voltage of 2.5-3.5 V. The influence of a molecule structure on the spectra and quantum yield of fluorescence as well as on the electroluminescent properties of the compounds is shown. Results of quantum-chemical calculations in the context of the density functional theory of the structure and characteristics of main molecular orbitals are presented.

  1. Production and characterization of a novel yeast extracellular invertase activity towards improved dibenzothiophene biodesulfurization.

    PubMed

    Arez, Bruno F; Alves, Luís; Paixão, Susana M

    2014-11-01

    The main goal of this work was the production and characterization of a novel invertase activity from Zygosaccharomyces bailii strain Talf1 for further application to biodesulfurization (BDS) in order to expand the exploitable alternative carbon sources to renewable sucrose-rich feedstock. The maximum invertase activity (163 U ml(-1)) was achieved after 7 days of Z. bailii strain Talf1 cultivation at pH 5.5-6.0, 25 °C, and 150 rpm in Yeast Malt Broth with 25 % Jerusalem artichoke pulp as inducer substrate. The optimum pH and temperature for the crude enzyme activity were 5.5 and 50 °C, respectively, and moreover, high stability was observed at 30 °C for pH 5.5-6.5. The application of Talf1 crude invertase extract (1 %) to a BDS process by Gordonia alkanivorans strain 1B at 30 °C and pH 7.5 was carried out through a simultaneous saccharification and fermentation (SSF) approach in which 10 g l(-1) sucrose and 250 μM dibenzothiophene were used as sole carbon and sulfur sources, respectively. Growth and desulfurization profiles were evaluated and compared with those of BDS without invertase addition. Despite its lower stability at pH 7.5 (loss of activity within 24 h), Talf1 invertase was able to catalyze the full hydrolysis of 10 g l(-1) sucrose in culture medium into invert sugar, contributing to a faster uptake of the monosaccharides by strain 1B during BDS. In SSF approach, the desulfurizing bacterium increased its μmax from 0.035 to 0.070 h(-1) and attained a 2-hydroxybiphenyl productivity of 5.80 μM/h in about 3 days instead of 7 days, corresponding to an improvement of 2.6-fold in relation to the productivity obtained in BDS process without invertase addition. PMID:25163885

  2. Compressed-sensing (CS)-based digital breast tomosynthesis (DBT) reconstruction for low-dose, accurate 3D breast X-ray imaging

    NASA Astrophysics Data System (ADS)

    Park, Yeonok; Cho, Hyosung; Je, Uikyu; Hong, Daeki; Lee, Minsik; Park, Chulkyu; Cho, Heemoon; Choi, Sungil; Koo, Yangseo

    2014-08-01

    In practical applications of three-dimensional (3D) tomographic techniques, such as digital breast tomosynthesis (DBT), computed tomography (CT), etc., there are often challenges for accurate image reconstruction from incomplete data. In DBT, in particular, the limited-angle and few-view projection data are theoretically insufficient for exact reconstruction; thus, the use of common filtered-backprojection (FBP) algorithms leads to severe image artifacts, such as the loss of the average image value and edge sharpening. One possible approach to alleviate these artifacts may employ iterative statistical methods because they potentially yield reconstructed images that are in better accordance with the measured projection data. In this work, as another promising approach, we investigated potential applications to low-dose, accurate DBT imaging with a state-of-the-art reconstruction scheme based on compressed-sensing (CS) theory. We implemented an efficient CS-based DBT algorithm and performed systematic simulation works to investigate the imaging characteristics. We successfully obtained DBT images of substantially very high accuracy by using the algorithm and expect it to be applicable to developing the next-generation 3D breast X-ray imaging system.

  3. Detection of dibenzothiophene in mussel, Mytilus edulis, as a marker of pollution by organosulfur compounds in a marine environment

    SciTech Connect

    Kira, S.; Izumi, T.; Ogata, M.

    1983-11-01

    Organosulfur compounds are minor components of crude oil and of some fuel oils. Although the quantity of these compounds depends on the source of production, generally it ranges from 0.002 to nearly 30% in crude oil, found as sulfur containing hydrocarbons. Mussels are a well-known biological monitor of marine pollutants which scientists call ''the mussel watch''. But few reports have been published on organosulfur compound contamination in field mussel samples. In the present study, the authors identified several organosulfur compound contamination in field mussel samples. In the present study, the authors identified several organosulfur compounds through GC-MS, and measured the levels of DBT through GC-flame photometric detector (GC-FPD), in both mussels and in water of the environment. The calculated concentration ratio of DBT in mussels to that in water ranged up to 500 in the field sample and 800 or higher after and experimental exposure. The estimated biological half-life or DBT from field mussel samples was about 9 days in clean sea water.

  4. Regio- and stereospecific oxidation of fluorene, dibenzofuran, and dibenzothiophene by naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.

    PubMed Central

    Resnick, S M; Gibson, D T

    1996-01-01

    The regio- and stereospecific oxidation of fluorene, dibenzofuran, and dibenzothiophene was examined with mutant and recombinant strains expressing naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4. The initial oxidation products were isolated and identified by gas chromatography-mass spectrometry and nuclear magnetic resonance spectrometry. Salicylate-induced cells of Pseudomonas sp. strain 9816/11 and isopropyl-beta-D-thiogalactopyranoside-induced cells of Escherichia coli JM109(DE3)(pDTG141) oxidized fluorene to (+)-(3S,4R)-cis-3,4-dihydroxy-3,4-dihydrofluorene (80 to 90% relative yield; > 95% enantiomeric excess [ee]) and 9-fluorenol (< 10% yield). The same cells oxidized dibenzofuran to (1R,2S)-cis-1,2-dihydroxy-1, 2-dihydrodibenzofuran (60 to 70% yield; > 95% ee) and (3S,4R)-cis-3, 4-dihydroxy-3,4-dihydrodibenzofuran (30 to 40% yield; > 95% ee). Induced cells of both strains, as well as the purified dioxygenase, also oxidized dibenzothiophene to (+)-(1R,2S)-cis-1,2-dihydroxy-1, 2-dihydrodibenzothiophene (84 to 87% yield; > 95% ee) and dibenzothiophene sulfoxide (< 15% yield). The major reaction catalyzed by naphthalene dioxygenase with each substrate was stereospecific dihydroxylation in which the cis-dihydrodiols were of identical regiochemistry and of R configuration at the benzylic center adjacent to the bridgehead carbon atom. The regiospecific oxidation of dibenzofuran differed from that of the other substrates in that a significant amount of the minor cis-3,4-dihydrodiol regioisomer was formed. The results indicate that although the absolute stereochemistry of the cis-diene diols was the same, the nature of the bridging atom or heteroatom influenced the regiospecificity of the reactions catalyzed by naphthalene dioxygenase. PMID:8899998

  5. Reactive carbon microspheres prepared by surface-grafting 4-(chloromethyl)phenyltrimethoxysilane for preparing molecularly imprinted polymer

    NASA Astrophysics Data System (ADS)

    Liu, Weifeng; Zhao, Huijun; Yang, Yongzhen; Liu, Xuguang; Xu, Bingshe

    2013-07-01

    Carbon microspheres (CMSs) were oxidized by a mixture of concentrated sulfuric and nitric acids, and modified by 4-(chloromethyl)phenyltrimethoxysilane to give reactive surface. Then, by adopting the surface molecular imprinting technique, dibenzothiophene (DBT) molecule-imprinted material MIP-DBT/CMSs was prepared with methacrylic acid as functional monomer and ethylene glycol dimethacrylate as crosslinking agent. The binding character of MIP-DBT/CMSs toward DBT was investigated with static method by gas chromatography, using fluorene and biphenyl as the reference substances which are similar to DBT in chemical structure to a certain extent. The effects of reaction time, temperature, and coupling agent concentration during silanization were investigated. The results show that the optimized conditions of silanization were 0.3 g oxidized-CMSs, 5% of CMTMS, 80 °C and 4 h. On the basis of silanized-CMSs, MIP-DBT/CMSs was synthesized. The adsorption results show that MIP-DBT/CMSs possessed strong adsorption ability for DBT. The maximal adsorption amount reached up 88.83 mg/g, in comparison with 44.51 mg/g of the non-imprinted polymer. In addition, MIP-DBT/CMSs exhibited a good selective adsorption capacity for DBT than fluorene (19.86 mg/g) and biphenyl (15.33 mg/g). The adsorption behavior followed the pseudo second order kinetic model. And the Freundlich isotherm was found to describe well the equilibrium adsorption data.

  6. The ratios of dibenzothiophene to phenanthrene and pristane to phytane as indicators of depositional environment and lithology of petroleum source rocks

    NASA Astrophysics Data System (ADS)

    Hughes, William B.; Holba, Albert G.; Dzou, Leon I. P.

    1995-09-01

    The ratio of dibenzothiophene to phenanthrene and the ratio of pristane to phytane, when coupled together, provide a novel and convenient way to infer crude oil source rock depositional environments and lithologies. Such knowledge can significantly assist in identifying the source formation(s) in a basin thereby providing valuable guidance for further exploration. The ability to infer this information from analysis of a crude oil is especially valuable as frequently the earliest samples in a new area may be shows and/or drill stem test samples from exploratory wells which are characteristically drilled on structural highs stratigraphically remote from the source formation(s). A cross-plot of dibenzothiophene/phenanthrene versus the pristane/phytane ratios measured on seventy-five crude oils from forty-one known source rocks ranging in age from Ordovician to Miocene consistently classified the oils into the following environment/ lithology groups: marine carbonate; marine carbonate/ mixed and lacustrine sulfate-rich; lacustrine sulfate-poor; marine and lacustrine shale; and fluvial/deltaic carbonaceous shale and coal. The dibenzothiophene/phenanthrene ratio alone is an excellent indicator of source rock lithology with carbonates having ratios > 1 and shales having ratios < 1. The dibenzothiophene to phenanthrene and the pristane to phytane ratios can also be used to classify source rock paleodepositional environments. The classification scheme is based on the premise that these ratios reflect the different Eh-pH regimes resulting from the significant microbiological and chemical processes occurring during deposition and early diagenesis of sediments. The dibenzothiophene/phenanthrene ratio assesses the availability of reduced sulfur for incorporation into organic matter and the pristane/phytane ratio assesses the redox conditions within the depositional environment. Interpretation of these ratios has been aided by quantitative biomarker analysis and by carbon

  7. Luminescent properties, internal hydrogen bonds and π-π interactions of Cd(II), Zn(II), Co(II) complexes based on 2,8-di(pyridin-4-yl)dibenzothiophene and dicarboxylate ligands

    NASA Astrophysics Data System (ADS)

    Huang, Cheng-Yan; Wang, Jie; Ding, Zhi-Yuan; Cui, Kai

    2015-04-01

    Based on a V-shaped N-containing ligand [2,8-di(pyridin-4-yl)dibenzothiophene, DPDBT], three new coordination polymers with different dimensionality, namely, {[Cd2(DPDBT)2(DCPS)2(H2O)](H2O)}n (1), {[Zn(DPDBT)2(5-OH-bdc)]}n (2) and {[Co(DPDBT)2(H2O)4](hfipbb)}n (3), [H2DCPS = 4,4‧-dicarboxydiphenyl sulfone, 5-OH-H2bdc = 5-hydroxyisophthalic acid, H2hfipbb = 4,4‧-(Hexafluoroisopropylidene)bis(benzoic acid)], have been synthesized under solvothermal conditions. Complex 1 exhibits a 2D structure with two different kinds of binuclear cadmium cluster units. The formation from 0D, 1D, 2D → 3D structures with hydrogen bonds and π-π interactions in 1-3 were investigated in details. In addition, luminescent properties of 1, 2 and related free ligands in the solid state have also been studied.

  8. Dibenzothiophene-Substituted Fullerene Derivative as Electron Acceptor for Polymer Solar Cells.

    PubMed

    Kim, Hee Un; Park, Jong Baek; Hwang, Do-Hoon

    2016-05-01

    A new fullerene derivative, [6,6]-dibenzo[b,d]thiophene-C61-butyric acid methyl ester (DBTC61BM) was synthesized from C60 using tosylhydrazone, and used as an electron-acceptor material for poly(3-hexylthiophene) (P3HT)-based organic photovoltaic cells. The synthesized DBTC61BM was used to modify the basic structure of [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) by replacing the aromatic part with dibenzo[b,d]thiophene. The solubilities of DBTC61BM and PC61BM are similar; they have good solubilities in common organic solvents such as dichloromethane, chloroform, toluene, and 1,2-dichlorobenzene. The Stern-Volmer quenching constant (K(sv)) of DBTC61BM was 7.14 x 10(3) M(-1), and was correlated with the binding affinity between the fluorophore and a quencher. The lowest unoccupied molecular orbital energy level of DBTC61BM was -3.71 eV. The charge-carrier mobility of a P3HT:DBTC61BM blend film was determined using the space-charge-limited current method; the electron mobility value obtained for the P3HT:DBTC61BM blend film was 2.13 x 10(-4) cm2 V(-1) s(-1). Photovoltaic devices were fabricated using P3HT as the electron donor and DBTC61BM as the electron acceptor. Among the fabricated devices, photovoltaic cells with the structure ITO/PEDOT:PSS/P3HT:DBTC61BM/LiF/Al showed the highest power conversion efficiency, namely 3.23%, with an open-circuit voltage of 0.64 V, short-circuit-current density of 8.14 mA cm(-2), and fill factor of 0.59, under AM 1.5 G (100 mW cm(-2)) illumination. PMID:27483863

  9. Mechanistic analysis of ultrasound assisted enzymatic desulfurization of liquid fuels using horseradish peroxidase.

    PubMed

    Bhasarkar, Jaykumar; Borah, Arup Jyoti; Goswami, Pranab; Moholkar, Vijayanand S

    2015-11-01

    This study has attempted to gain physical insight into ultrasound-assisted enzymatic desulfurization using system comprising horseradish peroxidase enzyme and dibenzothiophene (DBT). Desulfurization pathway (comprising DBT-sulfoxide and DBT-sulfone as intermediates and 4-methoxy benzoic acid as final product) has been established with GC-MS analysis. Intrinsic fluorescence and circular dichroism spectra of ultrasound-treated enzyme reveal conformational changes in secondary structure (reduction in α-helix and β-conformations and increase in random coil content) leading to enhancement in activity. Concurrent analysis of desulfurization profiles, Arrhenius and thermodynamic parameters, and simulations of cavitation bubble dynamics reveal that strong micro-convection generated by sonication enhances enzyme activity and desulfurization kinetics. Parallel oxidation of DBT by radicals generated from transient cavitation gives further boost to desulfurization kinetics. However, random motion of enzyme molecules induced by shock waves reduces frequency factor and limits the ultrasonic enhancement of enzymatic desulfurization. PMID:26231128

  10. Evaluation of the image quality in digital breast tomosynthesis (DBT) employed with a compressed-sensing (CS)-based reconstruction algorithm by using the mammographic accreditation phantom

    NASA Astrophysics Data System (ADS)

    Park, Yeonok; Cho, Heemoon; Je, Uikyu; Cho, Hyosung; Park, Chulkyu; Lim, Hyunwoo; Kim, Kyuseok; Kim, Guna; Park, Soyoung; Woo, Taeho; Choi, Sungil

    2015-12-01

    In this work, we have developed a prototype digital breast tomosynthesis (DBT) system which mainly consists of an x-ray generator (28 kVp, 7 mA s), a CMOS-type flat-panel detector (70-μm pixel size, 230.5×339 mm2 active area), and a rotational arm to move the x-ray generator in an arc. We employed a compressed-sensing (CS)-based reconstruction algorithm, rather than a common filtered-backprojection (FBP) one, for more accurate DBT reconstruction. Here the CS is a state-of-the-art mathematical theory for solving the inverse problems, which exploits the sparsity of the image with substantially high accuracy. We evaluated the reconstruction quality in terms of the detectability, the contrast-to-noise ratio (CNR), and the slice-sensitive profile (SSP) by using the mammographic accreditation phantom (Model 015, CIRS Inc.) and compared it to the FBP-based quality. The CS-based algorithm yielded much better image quality, preserving superior image homogeneity, edge sharpening, and cross-plane resolution, compared to the FBP-based one.

  11. Improving mass detection using combined feature representations from projection views and reconstructed volume of DBT and boosting based classification with feature selection

    NASA Astrophysics Data System (ADS)

    Kim, Dae Hoe; Kim, Seong Tae; Ro, Yong Man

    2015-11-01

    In digital breast tomosynthesis (DBT), image characteristics of projection views and reconstructed volume are different and both have the advantage of detecting breast masses, e.g. reconstructed volume mitigates a tissue overlap, while projection views have less reconstruction blur artifacts. In this paper, an improved mass detection is proposed by using combined feature representations from projection views and reconstructed volume in the DBT. To take advantage of complementary effects on different image characteristics of both data, combined feature representations are extracted from both projection views and reconstructed volume concurrently. An indirect region-of-interest segmentation in projection views, which projects volume-of-interest in reconstructed volume into the corresponding projection views, is proposed to extract combined feature representations. In addition, a boosting based classification with feature selection has been employed for selecting effective feature representations among a large number of combined feature representations, and for reducing false positives. Experiments have been conducted on a clinical data set that contains malignant masses. Experimental results demonstrate that the proposed mass detection can achieve high sensitivity with a small number of false positives. In addition, the experimental results demonstrate that the selected feature representations for classifying masses complementarily come from both projection views and reconstructed volume.

  12. Improving mass detection using combined feature representations from projection views and reconstructed volume of DBT and boosting based classification with feature selection.

    PubMed

    Kim, Dae Hoe; Kim, Seong Tae; Ro, Yong Man

    2015-11-21

    In digital breast tomosynthesis (DBT), image characteristics of projection views and reconstructed volume are different and both have the advantage of detecting breast masses, e.g. reconstructed volume mitigates a tissue overlap, while projection views have less reconstruction blur artifacts. In this paper, an improved mass detection is proposed by using combined feature representations from projection views and reconstructed volume in the DBT. To take advantage of complementary effects on different image characteristics of both data, combined feature representations are extracted from both projection views and reconstructed volume concurrently. An indirect region-of-interest segmentation in projection views, which projects volume-of-interest in reconstructed volume into the corresponding projection views, is proposed to extract combined feature representations. In addition, a boosting based classification with feature selection has been employed for selecting effective feature representations among a large number of combined feature representations, and for reducing false positives. Experiments have been conducted on a clinical data set that contains malignant masses. Experimental results demonstrate that the proposed mass detection can achieve high sensitivity with a small number of false positives. In addition, the experimental results demonstrate that the selected feature representations for classifying masses complementarily come from both projection views and reconstructed volume. PMID:26529080

  13. Ranking inconsistencies in the assessment of digital breast tomosynthesis (DBT) reconstruction algorithms using a location-known task and a search task

    NASA Astrophysics Data System (ADS)

    He, Xin; Zeng, Rongping; Samuelson, Frank; Sahiner, Berkman

    2016-03-01

    In this work, we validated a task-based performance figure-of-merit (FOM) by investigating ranking inconsistencies due to lurking variable/factors. We applied a falsifiable search assessment theory to assessing digital breast tomosynthesis (DBT) image quality using a scanning channelized Hotelling observer (CHO) on a simulated DBT dataset. We compared the performance of five reconstruction algorithms: filter back projection (FBP), maximum likelihood (ML), simultaneous algebraic reconstruction technique (SART), total-variation regularized least square estimator (TVLS) with strong and mild regularization settings. The results showed that the location-known-exactly (LKE) detection performance was almost identical for the five reconstruction algorithms. However the search characteristic as described by effective set size (M*) and search AUC value, ranked them differently. To falsify/corroborate our evaluations on search characteristic and performance, we conducted an image-size test. This test demonstrated an agreement between theoretical predictions and empirically measured observer performance in absolute performance levels, except for the ML algorithm. We concluded that evidence corroborated our evaluations, except that for the ML algorithm where our evaluation was wrong. Further investigation of the wrong evaluation in the ML case revealed a lurking variable that affected system performance ranking in search when AUC value was used as the FOM. This further confirmed that our evaluation in its current form for the ML algorithm was indeed wrong. We also noted that the ranking inconsistencies exist even when the AUC value was used as the FOM, and the falsifiable nature of M* allowed such inconsistencies to be identified.

  14. Annealing effect on donor-acceptor interface and its impact on the performance of organic photovoltaic devices based on PSiF-DBT copolymer and C{sub 60}

    SciTech Connect

    Marchiori, Cleber F. N.; Yamamoto, Natasha A. D.; Koehler, Marlus; Roman, Lucimara S.; Matos, Carolina F.; Zarbin, Aldo J. G.; Kujala, Jiri; Tuomisto, Filip; Macedo, Andréia G.

    2015-03-30

    In this work, poly[2,7-(9,9-bis(2-ethylhexyl)-dibenzosilole)-alt-4,7-bis(thiophen-2-yl) benzo-2,1,3-thiadiazole] (PSiF-DBT) was used as active layer in bilayer solar cell with C{sub 60} as electron acceptor. As cast devices already show reasonable power conversion efficiency (PCE) that increases to 4% upon annealing at 100 °C. Space charge limited measurements of the hole mobility (μ) in PSiF-DBT give μ ∼ 1.0 × 10{sup −4} cm{sup 2}/(V s) which does not depend on the temperature of the annealing treatment. Moreover, positron annihilation spectroscopy experiments revealed that PSiF-DBT films are well stacked even without the thermal treatment. The variations in the transport of holes upon annealing are then small. As a consequence, the PCE rise was mainly induced by the increase of the polymer surface roughness that leads to a more effective interface for exciton dissociation at the PSiF-DBT/fullerene heterojunction.

  15. Ultrasound-promoted chemical desulfurization of Illinois coals

    SciTech Connect

    Chao, S.S.; Mensinger, M.C.

    1991-01-01

    Ultrasound can increase the rates of chemical reactions by many orders of magnitude at conditions much less severe than if the process were conducted without ultrasound. IGT proposed this work to promote chemical reactions that remove organic sulfur from coal using ultrasound at relatively mild conditions. Two model compounds (dibenzyl sulfide (DBS) and dibenzothiophene (DBT)) impregnated on a carbon substrate, and two coals from the Illinois Basin Coal Sample Program were used for this study. A number of agents, oxidizing chemicals and hydroperoxide precursors, were employed to react with organically bound sulfur in a variety of media. Desulfurization tests were conducted in a low-intensity ultrasonic bath unit and a high-intensity bench-scale ultrasonic unit. Results showed that DBS can be partially decomposed under milder conditions than those required for DBT. Hydrogen peroxide (H{sub 2}O{sub 2}) and tert-butyl hydroperoxide (TBPO) in acetic acid solution were the most effective for oxidation of DBS and DBT. Mo(CO){sub 6} catalyst was effective for oxidative desulfurization of the C-DBS and C-DBT model coals. Ultrasonic irradiation appears to promote the oxidative reactions of DBS and DBT through its kinetic effect of transporting oxidants onto the DBS and DBT sites on the carbon substrate. Increasing the reactor pressure to 100 psig did not affect the overall DBT conversion. However, hydroperoxide precursors, such as tetralin and decalin (used neat) under 100 psig oxygen converted a small amount of DBT to DBT sulfoxide. A limited number of tests were conducted with IBC-101 coal using H{sub 2}O{sub 2} and TBPO in acetic acid. About 60% of the pyritic sulfur or 20% total sulfur was removed. 8 refs., 1 fig., 5 tabs.

  16. Oxidative desulfurization of model diesel via dual activation by a protic ionic liquid.

    PubMed

    Lü, Hongying; Wang, Shunan; Deng, Changliang; Ren, Wanzhong; Guo, Baocun

    2014-08-30

    A novel and green carboxylate-anion-based protic ionic liquid (PIL), [Hnmp]HCOO, was prepared through a simple and atom economic neutralization reaction between N-methyl-2-pyrrolidonium (NMP) and formic acids. Both FT-IR spectra and (1)H NMR confirmed its simple salt structure. [Hnmp]HCOO exhibited so high catalytic activity that the dibenzothiophene (DBT) removal reached 99% at 50°C in 3h under conditions of VPIL/Vmodel oil=1:10 and H2O2/DBT (O/S, molar ratio)=5. The catalytic oxidation reactivity of S-compounds was found to be in the order of DBT>4,6-dimethyldibenzothiophene (4,6-DMDBT)>benzothiophene (BT). The investigation on mechanism showed that oxidative desulfurization was realized through dual activation of PIL. Moreover, [Hnmp]HCOO can be recycled for five times with an unnoticeable decrease in desulfurization activity. PMID:25064259

  17. Second generation anthropomorphic physical phantom for mammography and DBT: Incorporating voxelized 3D printing and inkjet printing of iodinated lesion inserts

    NASA Astrophysics Data System (ADS)

    Sikaria, Dhiraj; Musinsky, Stephanie; Sturgeon, Gregory M.; Solomon, Justin; Diao, Andrew; Gehm, Michael E.; Samei, Ehsan; Glick, Stephen J.; Lo, Joseph Y.

    2016-03-01

    Physical phantoms are needed for the evaluation and optimization of new digital breast tomosynthesis (DBT) systems. Previously, we developed an anthropomorphic phantom based on human subject breast CT data and fabricated using commercial 3D printing. We now present three key advancements: voxelized 3D printing, photopolymer material doping, and 2D inkjet printing of lesion inserts. First, we bypassed the printer's control software in order to print in voxelized form instead of conventional STL surfaces, thus improving resolution and allowing dithering to mix the two photopolymer materials into arbitrary proportions. We demonstrated ability to print details as small as 150μm, and dithering to combine VeroWhitePlus and TangoPlus in 10% increments. Second, to address the limited attenuation difference among commercial photopolymers, we evaluated a beta sample from Stratasys with increased TiO2 doping concentration up to 2.5%, which corresponded to 98% breast density. By spanning 36% to 98% breast density, this doubles our previous contrast. Third, using inkjet printers modified to print with iopamidol, we created 2D lesion patterns on paper that can be sandwiched into the phantom. Inkjet printing has advantages of being inexpensive and easy, and more contrast can be delivered through overprinting. Printing resolution was maintained at 210 μm horizontally and 330 μm vertically even after 10 overprints. Contrast increased linearly with overprinting at 0.7% per overprint. Together, these three new features provide the basis for creating a new anthropomorphic physical breast phantom with improved resolution and contrast, as well as the ability to insert 2D lesions for task-based assessment of performance.

  18. Effect of omega-3 polyunsaturated fatty acid treatment over mechanical allodynia and depressive-like behavior associated with experimental diabetes.

    PubMed

    Redivo, Daiany D B; Schreiber, Anne K; Adami, Eliana R; Ribeiro, Deidiane E; Joca, Samia R L; Zanoveli, Janaína M; Cunha, Joice M

    2016-02-01

    Neuropathic pain and depression are very common comorbidities in diabetic patients. As the pathophysiological mechanisms are very complex and multifactorial, current treatments are only symptomatic and often worsen the glucose control. Thus, the search for more effective treatments are extremely urgent. In this way, we aimed to investigate the effect of chronic treatment with fish oil (FO), a source of omega-3 polyunsaturated fatty acid, over the mechanical allodynia and in depressive-like behaviors in streptozotocin-diabetic rats. It was observed that the diabetic (DBT) animals, when compared to normoglycemic (NGL) animals, developed a significant mechanical allodynia since the second week after diabetes induction, peaking at fourth week which is completely prevented by FO treatment (0.5, 1 or 3g/kg). Moreover, DBT animals showed an increase of immobility frequency and a decrease of swimming and climbing frequencies in modified forced swimming test (MFST) since the second week after diabetes injection, lasting up at the 4th week. FO treatment (only at a dose of 3g/kg) significantly decreased the immobility frequency and increased the swimming frequency, but did not induce significant changes in the climbing frequency in DBT rats. Moreover, it was observed that DBT animals had significantly lower levels of BDNF in both hippocampus and pre frontal cortex when compared to NGL rats, which is completely prevented by FO treatment. In conclusion, our study demonstrates that FO treatment was able to prevent the mechanical allodynia and the depressive-like behaviors in DBT rats, which seems to be related to its capacity of BDNF level restoration. PMID:26546881

  19. Applications of micellar enzymology to clean coal technology

    SciTech Connect

    Walsh, C.T.

    1990-01-20

    This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid Dibenzothiophene (DBT) and ehtylphenylsulfide (EPS)are serving as serving as models of organic sulfur-containing components of coal in initial studies.

  20. Applications of micellar enzymology to clean coal technology. First quarterly report

    SciTech Connect

    Walsh, C.T.

    1990-01-20

    This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid Dibenzothiophene (DBT) and ehtylphenylsulfide (EPS)are serving as serving as models of organic sulfur-containing components of coal in initial studies.

  1. Applications of micellar enzymology to clean coal technology

    SciTech Connect

    Walsh, C.T.

    1990-10-26

    This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid Dibenzothiophene (DBT) and ethlyphenylsulfide (EPS) are serving as models of organic sulfur-containing components of coal in initial studies. A goal of this project is to define a reverse micelle system that optimizes the catalytic activity of enzymes toward desulfurization of model compounds and ultimately coal samples. Among the variables which will be examined are the surfactant, the solvent, the water:surfactant ration and the pH and ionic strength of the aqueous phase. Studies were carried out with HRP, Type I RZ=1.2 and Type VI RZ=3.2 and laccase from Polyporus versicolor. Substrates for HRP assays included hydrogen peroxide, DBT, DBT sulfoxide, and DBT sulfone. Buffers included sodium phosphate. For formation of reverse micelle solutions the surfactant AOT, di(2-ethyl-hexyl)sodium sulphosuccinate, was obtained from Sigma Chemical Co. Isooctant was used as organic solvent. 12 refs., 5 figs., 3 tabs.

  2. Tributyltin and triphenyltin inhibit osteoclast differentiation through a retinoic acid receptor-dependent signaling pathway

    SciTech Connect

    Yonezawa, Takayuki; Hasegawa, Shin-ichi; Ahn, Jae-Yong; Cha, Byung-Yoon; Teruya, Toshiaki; Hagiwara, Hiromi; Nagai, Kazuo; Woo, Je-Tae; E-mail: jwoo@isc.chubu.ac.jp

    2007-03-30

    Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), have been widely used in agriculture and industry. Although these compounds are known to have many toxic effects, including endocrine-disrupting effects, their effects on bone resorption are unknown. In this study, we investigated the effects of organotin compounds, such as monobutyltin (MBT), dibutyltin (DBT), TBT, and TPT, on osteoclast differentiation using mouse monocytic RAW264.7 cells. MBT and DBT had no effects, whereas TBT and TPT dose-dependently inhibited osteoclast differentiation at concentrations of 3-30 nM. Treatment with a retinoic acid receptor (RAR)-specific antagonist, Ro41-5253, restored the inhibition of osteoclastogenesis by TBT and TPT. TBT and TPT reduced receptor activator of nuclear factor-{kappa}B ligand (RANKL) induced nuclear factor of activated T cells (NFAT) c1 expression, and the reduction in NFATc1 expression was recovered by Ro41-5253. Our results suggest that TBT and TPT suppress osteoclastogenesis by inhibiting RANKL-induced NFATc1 expression via an RAR-dependent signaling pathway.

  3. Acid-base accounting assessment of mine wastes using the chromium reducible sulfur method.

    PubMed

    Schumann, Russell; Stewart, Warwick; Miller, Stuart; Kawashima, Nobuyuki; Li, Jun; Smart, Roger

    2012-05-01

    The acid base account (ABA), commonly used in assessment of mine waste materials, relies in part on calculation of potential acidity from total sulfur measurements. However, potential acidity is overestimated where organic sulfur, sulfate sulfur and some sulfide compounds make up a substantial portion of the sulfur content. The chromium reducible sulfur (CRS) method has been widely applied to assess reduced inorganic sulfur forms in sediments and acid sulfate soils, but not in ABA assessment of mine wastes. This paper reports the application of the CRS method to measuring forms of sulfur commonly found in mine waste materials. A number of individual sulfur containing minerals and real waste materials were analyzed using both CRS and total S and the potential acidity estimates were compared with actual acidity measured from net acid generation tests and column leach tests. The results of the CRS analysis made on individual minerals demonstrate good assessment of sulfur from a range of sulfides. No sulfur was measured using the CRS method in a number of sulfate salts, including jarosite and melanterite typically found in weathered waste rocks, or from dibenzothiophene characteristic of organic sulfur compounds common to coal wastes. Comparison of ABA values for a number of coal waste samples demonstrated much better agreement of acidity predicted from CRS analysis than total S analysis with actual acidity. It also resulted in reclassification of most samples tested from PAF to NAF. Similar comparisons on base metal sulfide wastes generally resulted in overestimation of the acid potential by total S and underestimation of the acid potential by CRS in comparison to acidity measured during NAG tests, but did not generally result in reclassification. In all the cases examined, the best estimate of potential acidity included acidity calculated from both CRS and jarositic S. PMID:22444067

  4. Scandium-Triflate/Metal-Organic Frameworks: Remarkable Adsorbents for Desulfurization and Denitrogenation.

    PubMed

    Khan, Nazmul Abedin; Jhung, Sung Hwa

    2015-12-01

    Scandium-triflate (Sc(OTf)3) was introduced for the first time on metal-organic frameworks (MOFs), to utilize acidic Sc(OTf)3 for adsorptive desulfurization and denitrogenation of fuel containing benzothiophene (BT), dibenzothiophene (DBT), quinoline (QUI), and indole (IND). A remarkable improvement in the adsorption capacity (about 65% based on the weight of adsorbents; 90% based on the surface area of the adsorbents) was observed with the Sc(OTf)3/MOFs as compared to the virgin MOFs for the adsorption of BT from liquid fuel. The basic QUI was also adsorbed preferentially onto the acidic Sc(OTf)3/MOFs. However, nonsupported Sc(OTf)3 showed negligible adsorption capacities. The improved adsorptive performance for BT, DBT, and QUI might be derived from acid-base interactions between the acidic Sc(OTf)3 and basic adsorbates. On the other hand, the Sc(OTf)3, loaded on MOFs, reduced the adsorption capacity for neutral IND due to lack of interaction between the neutral adsorbate and acidic adsorbent and the reduced porosities of the modified adsorbents. The reusability of the adsorbents was found satisfactory up to the fourth run. On the basis of the result, it is suggested that metal-triflates, such as Sc(OTf)3, can be prospective materials for adsorptive desulfurization/denitrogenation of fuels when supported on porous materials such as MOFs. PMID:26575418

  5. Applications of micellar enzymology to clean coal technology. Ninth quarterly report

    SciTech Connect

    Walsh, C.T.

    1991-01-30

    This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid. Dibenzothiophene (DBT) and ethylphenylsulfide (EPS) are serving as models or organic sulfur-containing components of coal in initial studies. A goal of this project is to define a reverse micelle system that optimizes the catalytic activity of enzymes toward desulfurization of model compounds and ultimately coal samples. Among the variables which will be examined are the surfactant, the solvent, the water:surfactant ratio and the pH and ionic strength of the aqueous phase.

  6. Applications of micellar enzymology to clean coal technology

    SciTech Connect

    Walsh, C.T.

    1991-01-30

    This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid. Dibenzothiophene (DBT) and ethylphenylsulfide (EPS) are serving as models or organic sulfur-containing components of coal in initial studies. A goal of this project is to define a reverse micelle system that optimizes the catalytic activity of enzymes toward desulfurization of model compounds and ultimately coal samples. Among the variables which will be examined are the surfactant, the solvent, the water:surfactant ratio and the pH and ionic strength of the aqueous phase.

  7. Applications of micellar enzymology to clean coal technology

    SciTech Connect

    Walsh, C.T.

    1991-10-21

    This project is designed to develop methods for precombustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid (Figure 1). Dibenzothiophene (DBT) and ethylphenylsulfide (EPS) are serving as models of organic sulfur-containing components of coal in initial studies. A goal of this project is to define a reverse micelle system that optimizes the catalytic activity of enzymes toward desulfurization of model compounds and ultimately coal samples. 12 refs., 2 figs., 7 tabs.

  8. Applications of micellar enzymology to clean coal technology. Tenth quarterly report

    SciTech Connect

    Walsh, C.T.

    1992-04-29

    Full implementation of coal fuel sources will require more effective methods of providing ``clean coal`` as a fuel source. Methods must be developed to reduce the sulfur content of coal which significantly contributes to environmental pollution. This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid. Dibenzothiophene (DBT) and ethylphenylsulfide (EPS) are serving as models of organic sulfur-containing components of coal in initial studies.

  9. Deep Desulfurization of Extensively Hydrodesulfurized Middle Distillate Oil by Rhodococcus sp. Strain ECRD-1

    PubMed Central

    Grossman, M. J.; Lee, M. K.; Prince, R. C.; Minak-Bernero, V.; George, G. N.; Pickering, I. J.

    2001-01-01

    Dibenzothiophene (DBT), and in particular substituted DBTs, are resistant to hydrodesulfurization (HDS) and can persist in fuels even after aggressive HDS treatment. Treatment by Rhodococcus sp. strain ECRD-1 of a middle distillate oil whose sulfur content was virtually all substituted DBTs produced extensive desulfurization and a sulfur level of 56 ppm. PMID:11282654

  10. Deep desulfurization of extensively hydrodesulfurized middle distillate oil by Rhodococcus sp. strain ECRD-1.

    PubMed

    Grossman, M J; Lee, M K; Prince, R C; Minak-Bernero, V; George, G N; Pickering, I J

    2001-04-01

    Dibenzothiophene (DBT), and in particular substituted DBTs, are resistant to hydrodesulfurization (HDS) and can persist in fuels even after aggressive HDS treatment. Treatment by Rhodococcus sp. strain ECRD-1 of a middle distillate oil whose sulfur content was virtually all substituted DBTs produced extensive desulfurization and a sulfur level of 56 ppm. PMID:11282654

  11. Amino acids

    MedlinePlus

    Amino acids are organic compounds that combine to form proteins . Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids ...

  12. The sorption of humic acids to mineral surfaces and their roles in contaminant binding

    SciTech Connect

    Murphy, E.M.; Zachara, J.M.; Smith, S.C.; Phillips, J.L.

    1990-11-01

    Humic substances dissolved in groundwater may adsorb to certain mineral surfaces, rendering hydrophilic surfaces hydrophobic and making them sorbents for hydrophobic organic compounds (HOC). The sorption of humic and fulvic acids (International Humic Substance Society, IHSS, reference samples) on hematite and kaolinite was investigated to determine how natural organic coatings influence HOC sorption. The sorption behavior of the humic substances was consistent with a ligand-exchange mechanism, and the amount of sorption depended on the concentration of hydroxylated surface sites on the mineral and the properties of the humic substance. The sorption of the humic substances to two solids was proportional to their aromatic carbon content and inversely proportional to the O/C ratio. Increasing quantities of sorbed humic substances (f{sub oc}0.01 to 0. 5%) increased the sorption of carbazole, dibenzothiophene, and anthracene. Peat humic acid, the most aromatic coating, showed the greatest sorption enhancement of HOC when sorbed to hematite. In addition, HOC sorption was greater on organic coating formed at low ionic strength (I = 0.005) as compared to higher ionic strength (I = 0.1). We suggest that both the mineral surface and the ionic strength of the electrolyte affect the interfacial configuration of the sorbed humic substance, altering the size or accessibly of hydrophobic domains on the humic molecule to HOC. 30 refs., 5 figs.

  13. Molecular biological enhancement of coal desulfurization: Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae

    SciTech Connect

    Krawiec, S.

    1991-08-30

    The DbtS{sup +} phenotype is defined as the selective ability to oxidize the sulfur in dibenzothiophene (DBT) successively to dibenzothiophene-5-oxide, dibenzosulfone, and, finally, either o, o'-biphenol or monohydroxybiphenyl. By using a fluorescent assay, many Pseudomonas putida isolates having a DbtS{sup +} phenotype have been obtained. The ability of the isolates to generate o, o'-biphenol was confirmed with HPLC shortly after the time of isolation. The broad-host-range plasmid, R68.45, was introduced from P. putida PRS 2003 into many soil isolates. The plasmid was able to mobilize the determinants for the DbtS{sup +} phenotype. Accordingly, R68.45 and the determinants of the phenotype could be transferred simultaneously form soil isolates to P. aeruginosa 27853. The DbtS{sup +} phenotype in the isolates and in P. aeruginosa 27853 has proven to be unstable. Whether the instability is genetic, physiological, some combination of these two, or is founded on some other phenomenon is not known. Fresh Gram-positive isolates with the DbtS{sup +} phenotype have been isolated using the sulfur bioavailability assay. The DbtS{sup +} phenotype in these isolates appears to be stable. The product of desulfurization of DBT of dibenzosulfone is monohydroxybiphenyl. The nature of the endproduct has been confirmed by HPLC, colorimetry, GC/mass spectroscopy, and UV absorption. The kinetics of monohydroxybiphenyl production are being studied in batch and continuous culture. Study of the basis of cloning with R68.45 has continued. Data regarding in vivo cloning with R68.45 will be important when the genetic determinants for the DbtS{sup +} phenotype must be moved from one species to another by natural processes'' rather than through methods of genetic engineering. 8 refs., 3 figs.

  14. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  15. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  16. Aspartic acid

    MedlinePlus

    ... also called asparaginic acid. Aspartic acid helps every cell in the body work. It plays a role in: Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as ...

  17. Molecular biology of coal bio-desulfurization; Quarterly technical progress report, October 1--December 31, 1990

    SciTech Connect

    Young, K.D.; Gallagher, J.R.

    1991-01-25

    The aim of this project is to use the techniques of molecular genetics to identify, clone, sequence, and enhance the expression of proteins which remove sulfur covalently bound to coal. This includes the movement and expression of these proteins into bacterial species which may be more useful in the industrial application of a biological desulfurization process. This quarter we finalized the initial cloning and sequencing of the dibenzothiophene (DBT) metabolic (``dox``) genes from strain C18. In addition, we constructed several mutations in single dox genes and have begun to dissect the contribution of each gene product in the DBT degradation pathway. Using a probe derived from DNA adjacent to a transposon which inactivated DBT metabolism, the DBT active genes from A15 have been cloned and identified on cosmids. We have also electroporated Thiobacillus ferrooxidans with a plasmid containing a chloramphenicol resistant transposon. Colonies of T. ferrooxidans resistant to chloramphenicol were obtained.

  18. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  19. Amino acids

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  20. Mefenamic Acid

    MedlinePlus

    Mefenamic acid is used to relieve mild to moderate pain, including menstrual pain (pain that happens before or during a menstrual period). Mefenamic acid is in a class of medications called NSAIDs. ...

  1. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  2. Ascorbic Acid

    MedlinePlus

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  3. Acid mucopolysaccharides

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003368.htm Acid mucopolysaccharides To use the sharing features on this page, please enable JavaScript. Acid mucopolysaccharides is a test that measures the amount ...

  4. Ethacrynic Acid

    MedlinePlus

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  5. Valproic Acid

    MedlinePlus

    Valproic acid is used alone or with other medications to treat certain types of seizures. Valproic acid is also used to treat mania (episodes of ... to relieve headaches that have already begun. Valproic acid is in a class of medications called anticonvulsants. ...

  6. Fatty acids - trans fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The data supporting a negative effect of dietary trans fatty acids on cardiovascular disease risk is consistent. The primary dietary sources of trans fatty acids include partially hydrogenated fat and rudiment fat. The adverse effect of trans fatty acids on plasma lipoprotein profiles is consisten...

  7. Effect of photosensitizer and hydrogen peroxide on desulfurization of light oil by photochemical reaction and liquid-liquid extraction

    SciTech Connect

    Hirai, Takayuki; Shiraishi, Yasuhiro; Ogawa, Ken; Komasawa, Isao

    1997-03-01

    A desulfurization process for dibenzothiophene (DBT) by a combination of photochemical reaction and liquid-liquid extraction has been investigated. The DBT dissolved in tetradecane was photodecomposed by the use of a high-pressure mercury lamp and removed into the water phase at conditions of room temperature and atmospheric pressure. The addition of benzophenone (BZP), a triplet photosensitizer, enhanced the removal of DBT from tetradecane. This reaction, however, hardly proceeded in the presence of naphthalene (NP), probably because of triplet energy transfer from photoexcited DBT or BZP to ground-state NP. The addition of hydrogen peroxide enhanced the desulfurization of commercial light oil as well as the removal of DBT from tetradecane, since H{sub 2}O{sub 2} acted as a weak oxidizing agent for photoexcited DBT and interrupted the energy transfer from excited DBT to NP to some extent. In the case using a 30% H{sub 2}O{sub 2} solution, the desulfurization yield of commercial light oil was 75% following 24 h of photoirradiation and the sulfur content in the light oil was reduced from 0.2 wt % to less than 0.05 wt %.

  8. Biocatalytic desulfurization of thiophenic compounds and crude oil by newly isolated bacteria

    PubMed Central

    Mohamed, Magdy El-Said; Al-Yacoub, Zakariya H.; Vedakumar, John V.

    2015-01-01

    Microorganisms possess enormous highly specific metabolic activities, which enable them to utilize and transform nearly every known chemical class present in crude oil. In this context, one of the most studied biocatalytic processes is the biodesulfurization (BDS) of thiophenic sulfur-containing compounds such as benzothiophene (BT) and dibenzothiophene (DBT) in crude oils and refinery streams. Three newly isolated bacterial strains, which were affiliated as Rhodococcus sp. strain SA11, Stenotrophomonas sp. strain SA21, and Rhodococcus sp. strain SA31, were enriched from oil contaminated soil in the presence of DBT as the sole S source. GC-FID analysis of DBT-grown cultures showed consumption of DBT, transient formation of DBT sulfone (DBTO2) and accumulation of 2-hydroxybiphenyl (2-HBP). Molecular detection of the plasmid-borne dsz operon, which codes for the DBT desulfurization activity, revealed the presence of dszA, dszB, and dszC genes. These results point to the operation of the known 4S pathway in the BDS of DBT. The maximum consumption rate of DBT was 11 μmol/g dry cell weight (DCW)/h and the maximum formation rate of 2-HBP formation was 4 μmol/g DCW/h. Inhibition of both cell growth and DBT consumption by 2-HBP was observed for all isolates but SA11 isolate was the least affected. The isolated biocatalysts desulfurized other model DBT alkylated homologs. SA11 isolate was capable of desulfurizing BT as well. Resting cells of SA11 exhibited 10% reduction in total sulfur present in heavy crude oil and 18% reduction in total sulfur present in the hexane-soluble fraction of the heavy crude oil. The capabilities of the isolated bacteria to survive and desulfurize a wide range of S compounds present in crude oil are desirable traits for the development of a robust BDS biocatalyst to upgrade crude oils and refinery streams. PMID:25762990

  9. Enzymatic desulfurization of coal. Second quarterly report, October 1--December 15, 1988

    SciTech Connect

    Marquis, J.K.; Kitchell, J.P.

    1988-12-15

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  10. Enzymatic desulfurization of coal

    SciTech Connect

    Marquis, J.K. . School of Medicine); Kitchell, J.P. )

    1988-10-07

    Our current efforts to develop clean coal technology, emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  11. Enzymatic desulfurization of coal. Fourth quarterly report, March 16--June 15, 1989

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.; Marquis, J.K.

    1989-06-16

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes as well as commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  12. Enzymatic desulfurization of coal. First quarterly report, May 5--September 30, 1988

    SciTech Connect

    Marquis, J.K.; Kitchell, J.P.

    1988-10-07

    Our current efforts to develop clean coal technology, emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  13. Enzymatic desulfurization of coal

    SciTech Connect

    Marquis, J.K. . School of Medicine); Kitchell, J.P. )

    1988-12-15

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  14. Enzymatic desulfurization of coal

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V. ); Marquis, J.K. . School of Medicine)

    1989-06-16

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes as well as commercially available enzymes. Our work is focused on the treatment of model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  15. Acid Deposition

    EPA Science Inventory

    This indicator presents acid deposition trends in the contiguous U.S. from 1989 to 2007. Data are broken down by wet and dry deposition and deposition of nitrogen and sulfur compounds. Acid deposition is particularly damaging to lakes, streams, and forests and the plants and a...

  16. Acid rain

    SciTech Connect

    White, J.C. )

    1988-01-01

    This book presents the proceedings of the third annual conference sponsored by the Acid Rain Information Clearinghouse (ARIC). Topics covered include: Legal aspects of the source-receptor relationship: an energy perspective; Scientific uncertainty, agency inaction, and the courts; and Acid rain: the emerging legal framework.

  17. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  18. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  19. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657

  20. [Gastric Acid].

    PubMed

    Ruíz Chávez, R

    1996-01-01

    Gastric acid, a product of parietal cells secretion, full fills multiple biological roles which are absolutely necessary to keep corporal homeostasis. The production of the acid depends upon an effector cellular process represented in the first step by histamine, acetilcholine and gastrin, first messengers of the process. These interact with specific receptors than in sequence activate second messengers -cAMP and the calcium-calmodulin system- which afterwards activate a kinase. An specific protein is then phosphorilated by this enzyme, being the crucial factor that starts the production of acid. Finally, a proton bomb, extrudes the acid towards the gastric lumen. The secretion process mentioned above, is progressive lyactivated in three steps, two of which are stimulators -cephalic and gastric phases- and the other one inhibitor or intestinal phase. These stages are started by mental and neurological phenomena -thought, sight, smell or memory-; by food, drugs or other ingested substances; and by products of digestion. Changes in regulation of acid secretion, in the structure of gastro-duodenal mucosal barrier by a wide spectrum of factors and agents including food, drugs and H. pylori, are the basis of acid-peptic disease, entity in which gastric acid plays a fundamental role. From the therapeutic point of view, so at the theoretical as at the practical levels, t is possible to interfere with the secretion of acid by neutralization of some of the steps of the effector cellular process. An adequate knowledge of the basics related to gastric acid, allows to create strategies for the clinical handling of associated pathology, specifically in relation to peptic acid disease in all of the known clinical forms. PMID:12165790

  1. Acid fog

    SciTech Connect

    Hileman, B.

    1983-03-01

    Fog in areas of southern California previously thought to be pollution-free has been shown to have a pH as low as 1.69. It has been found to be most acidic after smoggy days, suggesting that it forms on the aerosol associated with the previously exiting smog. Studies on Whiteface Mountain in the Adirondacks show that fog water is often 10 times as acidic as rainwater. As a result of their studies, California plans to spend $4 million on acid deposition research in the coming year. (JMT)

  2. Folic acid

    MedlinePlus

    ... in the blood vessel to keep it open. Bipolar disorder. Taking folic acid does not appear to improve the antidepressant effects of lithium in people with bipolar disorder. However, taking folate with the medication valproate improves ...

  3. Mefenamic Acid

    MedlinePlus

    ... as mefenamic acid may cause ulcers, bleeding, or holes in the stomach or intestine. These problems may ... like coffee grounds, blood in the stool, or black and tarry stools.Keep all appointments with your ...

  4. ACID RAIN

    EPA Science Inventory

    Acid precipitation has become one of the major environmental problems of this decade. It is a challenge to scientists throughout the world. Researchers from such diverse disciplines as plant pathology, soil science, bacteriology, meteorology and engineering are investigating diff...

  5. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  6. Carnosic acid.

    PubMed

    Birtić, Simona; Dussort, Pierre; Pierre, François-Xavier; Bily, Antoine C; Roller, Marc

    2015-07-01

    Carnosic acid (salvin), which possesses antioxidative and antimicrobial properties, is increasingly exploited within the food, nutritional health and cosmetics industries. Since its first extraction from a Salvia species (∼70 years ago) and its identification (∼50 years ago), numerous articles and patents (∼400) have been published on specific food and medicinal applications of Rosmarinus and Salvia plant extracts abundant in carnosic acid. In contrast, relevant biochemical, physiological or molecular studies in planta have remained rare. In this overview, recent advances in understanding of carnosic acid distribution, biosynthesis, accumulation and role in planta, and its applications are summarised. We also discuss the deficiencies in our understanding of the relevant biochemical processes, and suggest the molecular targets of carnosic acid. Finally, future perspectives and studies related to its potential roles are highlighted. PMID:25639596

  7. Aminocaproic Acid

    MedlinePlus

    Amicar® Oral Solution ... Aminocaproic acid comes as a tablet and a solution (liquid) to take by mouth. It is usually ... it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away ...

  8. Tranexamic Acid

    MedlinePlus

    ... is used to treat heavy bleeding during the menstrual cycle (monthly periods) in women. Tranexamic acid is in ... tablets for more than 5 days in a menstrual cycle or take more than 6 tablets in a ...

  9. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  10. Bicarbonate-induced activation of H₂O₂ for metal-free oxidative desulfurization.

    PubMed

    Bokare, Alok D; Choi, Wonyong

    2016-03-01

    Efficient oxidative desulfurization (ODS) of model oil containing dibenzothiophene (DBT) and aromatic thiophenic derivatives has been achieved at room temperature using hydrogen peroxide activation by inorganic bicarbonate (HCO3(-)). Using in-situ formation of peroxymonocarbonate as oxidant, the transformation of main model substrate DBT to corresponding DBT-sulfone was easily accomplished in biphasic reaction conditions. In the presence of water-acetonitrile polar phase, increasing the water content upto 50% decreased the extraction capacity more than 3 times, but ∼ 90% DBT oxidation was still achieved. The oxidizing capacity of bicarbonate catalyst was maintained during repeated ODS cycles, but DBT removal efficiency was critically dependent on the extraction capacity of the polar phase. Under heterogeneous reaction conditions, bicarbonate-modified ion-exchange resin achieved similar ODS activity compared to the homogeneous catalytic system. Additionally, the efficient formation of peroxymonocarbonate using gaseous CO2 precursor in alkaline conditions was also utilized for DBT oxidation. The present study proposes the NaHCO3/H2O2 catalytic system as an efficient and cheap metal-free alternative for the oxidative removal of aromatic sulfur compounds from fuel oil. PMID:26561755

  11. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  12. Tailoring Silica-alumina Supported Pt-Pd As Poison Tolerant Catalyst For Aromatics Hydrogenation

    SciTech Connect

    Yu, Yanzhe; Gutierrez, Oliver Y.; Haller, Gary L.; Colby, Robert J.; Kabius, Bernd C.; Rob van Veen, J. A.; Jentys, Andreas; Lercher, Johannes A.

    2013-08-01

    The tailoring of the physicochemical and catalytic properties of mono- and bimetallic Pt-Pd catalysts supported on amorphous silica-alumina is studied. Electron energy loss spectroscopy and extended X-ray absorption fine structure analyses indicated that bimetallic Pt-Pd and relatively large monometallic Pd particles were formed, whereas the X-ray absorption near edge structure provided direct evidence for the electronic deficiency of the Pt atoms. The heterogeneous distribution of metal particles was also shown by high resolution transmission electron microscopy. The average structure of the bimetallic particles (Pt-rich core and Pd-rich shell) and the presence of Pd particles led to surface Pd enrichment, which was independently shown by IR spectra of adsorbed CO. The specific metal distribution, average size, and surface composition of the Pt-Pd particles depend to a large extent on the metal precursors. In the presence of NH3 ligands, Pt-Pd particles with a fairly homogeneous bulk and surface metal distribution were formed. Also high Lewis acid site concentration of the carrier leads to more homogeneous bimetallic particles. All catalysts were active for the hydrogenation of tetralin in the absence and presence of quinoline and dibenzothiophene (DBT). Monometallic Pt catalysts had the highest hydrogenation activity in poison-free and quinoline-containing feed. When DBT was present, bimetallic Pt-Pd catalysts with the most homogenous metal distribution showed the highest activity. The higher resistance of bimetallic catalysts towards sulfur poisoning compared to their monometallic Pt counterparts results from the weakened metal-sulfur bond on the electron deficient Pt atoms. Thus, increasing the fraction of electron deficient Pt on the surface of the bimetallic particles increases the efficiency of the catalyst in the presence of sulfur.

  13. Folic acid

    MedlinePlus

    ... disease called vitiligo, and an inherited disease called Fragile-X syndrome. It is also used for reducing harmful side ... to blood clots (ischemic stroke). Inherited disease called Fragile-X syndrome.Taking folic acid by mouth does not improve ...

  14. Acid rain

    SciTech Connect

    Not Available

    1984-06-01

    An overview is presented of acid rain and the problems it causes to the environment worldwide. The acidification of lakes and streams is having a dramatic effect on aquatic life. Aluminum, present in virtually all forest soils, leaches out readily under acid conditions and interferes with the gills of all fish, some more seriously than others. There is evidence of major damage to forests in European countries. In the US, the most severe forest damage appears to be in New England, New York's Adirondacks, and the central Appalachians. This small region is part of a larger area of the Northeast and Canada that appears to have more acid rainfall than the rest of the country. It is downwind from major coal burning states, which produce about one quarter of US SO/sub 2/ emissions and one sixth of nitrogen oxide emissions. Uncertainties exist over the causes of forest damage and more research is needed before advocating expensive programs to reduce rain acidity. The President's current budget seeks an expansion of research funds from the current $30 million per year to $120 million.

  15. Formic acid

    Integrated Risk Information System (IRIS)

    Formic acid ; CASRN 64 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  16. Selenious acid

    Integrated Risk Information System (IRIS)

    Selenious acid ; CASRN 7783 - 00 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  17. Benzoic acid

    Integrated Risk Information System (IRIS)

    Benzoic acid ; CASRN 65 - 85 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  18. Trichloroacetic acid

    Integrated Risk Information System (IRIS)

    Trichloroacetic acid ( TCA ) ; CASRN 76 - 03 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  19. Dichloroacetic acid

    Integrated Risk Information System (IRIS)

    Dichloroacetic acid ; CASRN 79 - 43 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  20. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 7 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  1. Cacodylic acid

    Integrated Risk Information System (IRIS)

    Cacodylic acid ; CASRN 75 - 60 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  2. Phosphoric acid

    Integrated Risk Information System (IRIS)

    Phosphoric acid ; CASRN 7664 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  3. Stearic Acid

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  4. Sulfur source-mediated transcriptional regulation of the rhlABC genes involved in biosurfactants production by Pseudomonas sp. strain AK6U

    PubMed Central

    Ismail, Wael; El Nayal, Ashraf M.; Ramadan, Ahmed R.; Abotalib, Nasser

    2014-01-01

    Despite the nutritional significance of sulfur, its influence on biosurfactants production has not been sufficiently studied. We investigated the expression of key biosurfactants production genes, rhlABC, in cultures of Pseudomonas sp. AK6U grown with inorganic or organic sulfur sources. AK6U grew with either inorganic sulfate (MgSO4), dibenzothiophene (DBT), or DBT-sulfone as a sole sulfur source in the presence of glucose as a carbon source. The AK6U cultures produced variable amounts of biosurfactants depending on the utilized sulfur source. Biosurfactants production profile of the DBT cultures was significantly different from that of the DBT-sulfone and inorganic sulfate cultures. The last two cultures were very similar in terms of biosurfactants productivity. Biosurfactants yield in the DBT cultures (1.3 g/L) was higher than that produced by the DBT-sulfone (0.5 g/L) and the inorganic sulfate (0.44 g/L) cultures. Moreover, the surface tension reduction in the DBT cultures (33 mN/m) was much stronger than that measured in the DBT-sulfone (58 mN/m) or inorganic sulfate (54 mN/m) cultures. RT-qPCR revealed variations in the expression levels of the rhlABC genes depending on the sulfur source. The DBT cultures had higher expression levels for the three genes as compared to the DBT-sulfone and inorganic sulfate cultures. There was no significant difference in the expression profiles between the DBT-sulfone and the MgSO4 cultures. The increased expression of rhlC in the DBT cultures is indicative for production of higher amounts of dirhamnolipids compared to the DBT-sulfone and inorganic sulfate cultures. The gene expression results were in good agreement with the biosurfactants production yields and surface tension measurements. The sulfur source mediates a fine-tuned mechanism of transcriptional regulation of biosurfactants production genes. Our findings can have an impact on industrial production of biosurfactants and other biotechnological processes like

  5. Determination of PASHs by various analytical techniques based on gas chromatography-mass spectrometry: application to a biodesulfurization process.

    PubMed

    Mezcua, Milagros; Fernández-Alba, Amadeo R; Boltes, Karina; Alonso Del Aguila, Raul; Leton, Pedro; Rodríguez, Antonio; García-Calvo, Eloy

    2008-06-15

    Polycyclic aromatic sulphur heterocyclic (PASH) compounds, such as dibenzothiophene (DBT) and alkylated derivatives are used as model compounds in biodesulfurization processes. The development of these processes is focused on the reduction of the concentration of sulphur in gasoline and gas-oil [D.J. Monticello, Curr. Opin. Biotechnol. 11 (2000) 540], in order to meet European Union and United States directives. The evaluation of biodesulfurization processes requires the development of adequate analytical techniques, allowing the identification of any transformation products generated. The identification of intermediates and final products permits the evaluation of the degradation process. In this work, seven sulfurated compounds and one non-sulfurated compound have been selected to develop an extraction method and to compare the sensitivity and identification capabilities of three different gas chromatography ionization modes. The selected compounds are: dibenzothiophene (DBT), 4-methyl-dibenzothiophene (4-m-DBT), 4,6-dimethyl-dibenzothiophene (4,6-dm-DBT) and 4,6 diethyl-dibenzothiophene (4,6 de-DBT), all of which can be used as model compounds in biodesulfurization processes; as well as dibenzothiophene sulfoxide (DBTO(2)), dibenzothiophene sulfone (DBTO) and 2-(2-hydroxybiphenyl)-benzenesulfinate (HBPS), which are intermediate products in biodesulfurization processes of DBT [ A. Alcon, V.E. Santos, A.B. Martín, P. Yustos, F. García-Ochoa, Biochem. Eng. J. 26 (2005) 168]. Furthermore, a non-sulfurated compound, 2-hydroxybiphenyl (2-HBP), has also been selected as it is the final product in the biodesulfurization process of DBT [A. Alcon, V.E. Santos, A.B. Martín, P. Yustos, F. García-Ochoa. Biochem. Eng. J. 26 (2005) 168]. Since, typically, biodesulfurization reactions take place in a biphasic medium, two extraction methods have been developed: a liquid-liquid extraction method for the watery phase and a solid phase extraction method for the organic phase

  6. Hydroxycarboxylic acids and salts

    DOEpatents

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  7. Protocols for the selective cleavage of carbon-sulfur bonds in coal. Technical report, March 1, 1992--May 30, 1992

    SciTech Connect

    Bausch, M.

    1992-10-01

    Chemical reactions that result in carbon-sulfur bond cleavage are an essential aspect of any protocol designed to remove organic sulfur from coal. Unfortunately, several classes of reactions that lead to carbon-sulfur bond cleavage are not well understood. Planned in ``Protocols for the Selective Cleavage of Carbon-Sulfur Bonds in Coal`` are reactions in which organic sulfur-containing coal model compounds are subjected to different conditions of temperature, solvent mixtures and radiation. Summarized in this quarterly report are results of our investigations of the following topics: (a) the reactions of coal model compounds, namely, benzyl phenyl sulfide (BPS), diphenyl sulfide (hereafter referred to as phenylsulfide, PS) and dibenzothiophene (DBT) with various reagents (Lewis acid catalysts, radical initiators, electron acceptors) using different solvents and temperature in an attempt to maximize the degree of carbon-sulfur (C-S) bond cleavage; and (b) the results of photooxidation of coal model compounds under controlled conditions. Quantitative product analyses are presented in this report.

  8. Applications of micellar enzymology to clean coal technology

    SciTech Connect

    Walsh, C.T.

    1993-03-09

    This project is designed to develop methods for precombustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid. Dibenzothiophene (DBT) and ethylphenylsulfide (EPS) are serving as models of organic sulfur-containing components of coal in initial studies. A goal of this project is to define a reverse micelle system that optimizes the catalytic activity of enzymes toward desulfurization of model compounds and ultimately coal samples. Studies by several groups (Martinek et al., 1981; Kabanov et al., 1988; Martinek, 1989; Verhaert et al., 1990) have shown that the surfactant AOT over a broad concentration range in organic solvents produces micelles, comparatively uniform in diameter, which incorporate hydrophilic enzymes. The activity (kcat) of certain enzymes in this system is higher than in aqueous solution. This surfactant is therefore being examined as a vehicle for enhancement of sulfoxidation reactions.

  9. Applications of micellar enzymology to clean coal technology. Twelfth quarterly report

    SciTech Connect

    Walsh, C.T.

    1993-03-09

    This project is designed to develop methods for precombustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid. Dibenzothiophene (DBT) and ethylphenylsulfide (EPS) are serving as models of organic sulfur-containing components of coal in initial studies. A goal of this project is to define a reverse micelle system that optimizes the catalytic activity of enzymes toward desulfurization of model compounds and ultimately coal samples. Studies by several groups (Martinek et al., 1981; Kabanov et al., 1988; Martinek, 1989; Verhaert et al., 1990) have shown that the surfactant AOT over a broad concentration range in organic solvents produces micelles, comparatively uniform in diameter, which incorporate hydrophilic enzymes. The activity (kcat) of certain enzymes in this system is higher than in aqueous solution. This surfactant is therefore being examined as a vehicle for enhancement of sulfoxidation reactions.

  10. Methylmalonic acid blood test

    MedlinePlus

    ... acid is a substance produced when proteins, called amino acids, in the body break down. The health care ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

  11. Folic acid - test

    MedlinePlus

    Folic acid is a type of B vitamin. This article discusses the test to measure the amount of folic acid in the blood. ... that may interfere with test results, including folic acid supplements. Drugs that can decrease folic acid measurements ...

  12. Uric acid urine test

    MedlinePlus

    The uric acid urine test measures the level of uric acid in urine. Uric acid level can also be checked using a blood ... help determine the cause of a high uric acid level in the blood. It may also be ...

  13. Methylmalonic acid blood test

    MedlinePlus

    The methylmalonic acid blood test measures the amount of methylmalonic acid in the blood. ... Methylmalonic acid is a substance produced when proteins, called amino acids, in the body break down. The health care ...

  14. Folic Acid and Pregnancy

    MedlinePlus

    ... 5 Things to Know About Zika & Pregnancy Folic Acid and Pregnancy KidsHealth > For Parents > Folic Acid and ... before conception and during early pregnancy . About Folic Acid Folic acid, sometimes called folate, is a B ...

  15. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  16. New bioactive fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to the new compounds, 7,10-dihydroxy-8(E)-octad...

  17. New Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecen...

  18. Biocatalytic Desulfurization Capabilities of a Mixed Culture during Non-Destructive Utilization of Recalcitrant Organosulfur Compounds.

    PubMed

    Ismail, Wael; El-Sayed, Wael S; Abdul Raheem, Abdul Salam; Mohamed, Magdy E; El Nayal, Ashraf M

    2016-01-01

    We investigated the biodesulfurization potential of a mixed culture AK6 enriched from petroleum hydrocarbons-polluted soil with dibenzothiophene (DBT) as a sulfur source. In addition to DBT, AK6 utilized the following compounds as sulfur sources: 4-methyldibenzothiophene (4-MDBT), benzothiophene (BT), and 4,6- dimethyldibenzothiophene (4,6-DM-DBT). None of these compounds supported the growth of AK6 as the sole carbon and sulfur source. AK6 could not grow on dibenzylsulfide (DBS) as a sulfur source. The AK6 community structure changed according to the provided sulfur source. The major DGGE bands represented members of the genera Sphingobacterium, Klebsiella, Pseudomonas, Stenotrophomonas, Arthrobacter, Mycobacterium, and Rhodococcus. Sphingobacterium sp. and Pseudomonas sp. were abundant across all cultures utilizing any of the tested thiophenic S-compounds. Mycobacterium/Rhodococcus spp. were restricted to the 4-MDBT culture. The 4-MDBT culture had the highest species richness and diversity. Biodesulfurization of DBT by resting cells of AK6 produced 2-hydroxybiphenyl (2-HBP) in addition to trace amounts of phenylacetate. AK6 transformed DBT to 2-hydroxybiphenyl with a specific activity of 9 ± 0.6 μM 2-HBP g dry cell weight(-1) h(-1). PCR confirmed the presence in the AK6 community of the sulfur-specific (4S) pathway genes dszB and dszC. Mixed cultures hold a better potential than axenic ones for the development of a biodesulfurization technology. PMID:26973637

  19. Biocatalytic Desulfurization Capabilities of a Mixed Culture during Non-Destructive Utilization of Recalcitrant Organosulfur Compounds

    PubMed Central

    Ismail, Wael; El-Sayed, Wael S.; Abdul Raheem, Abdul Salam; Mohamed, Magdy E.; El Nayal, Ashraf M.

    2016-01-01

    We investigated the biodesulfurization potential of a mixed culture AK6 enriched from petroleum hydrocarbons-polluted soil with dibenzothiophene (DBT) as a sulfur source. In addition to DBT, AK6 utilized the following compounds as sulfur sources: 4-methyldibenzothiophene (4-MDBT), benzothiophene (BT), and 4,6- dimethyldibenzothiophene (4,6-DM-DBT). None of these compounds supported the growth of AK6 as the sole carbon and sulfur source. AK6 could not grow on dibenzylsulfide (DBS) as a sulfur source. The AK6 community structure changed according to the provided sulfur source. The major DGGE bands represented members of the genera Sphingobacterium, Klebsiella, Pseudomonas, Stenotrophomonas, Arthrobacter, Mycobacterium, and Rhodococcus. Sphingobacterium sp. and Pseudomonas sp. were abundant across all cultures utilizing any of the tested thiophenic S-compounds. Mycobacterium/Rhodococcus spp. were restricted to the 4-MDBT culture. The 4-MDBT culture had the highest species richness and diversity. Biodesulfurization of DBT by resting cells of AK6 produced 2-hydroxybiphenyl (2-HBP) in addition to trace amounts of phenylacetate. AK6 transformed DBT to 2-hydroxybiphenyl with a specific activity of 9 ± 0.6 μM 2-HBP g dry cell weight−1 h−1. PCR confirmed the presence in the AK6 community of the sulfur-specific (4S) pathway genes dszB and dszC. Mixed cultures hold a better potential than axenic ones for the development of a biodesulfurization technology. PMID:26973637

  20. Molecular biology of coal bio-desulfurization

    SciTech Connect

    Young, K.D.; Gallagher, J.R.

    1991-07-18

    The aim of this project is to use the techniques of molecular genetics to identify, clone, sequence, and enhance the expression of proteins which remove sulfur covalently bound to coal. The cloned dox genes from strain C18 were more fully characterized. Another gene, doxG, is almost identical with the nahC gene, also involved in the naphthalene pathway. These results lead us to believe that dibenzothiophene (DBT) is degraded by the oxidative route along the naphthalene degradative pathway. At least one other gene, doxI, is implicated in the formation of the unidentified fluorescent product from DBT. The Rhodococcus rhodochrous isolate IGTS8 was mutated to produce a variant (strain UV1) that was negative for DBT utilization. This mutant was exposed to further rounds of UV mutagenesis and was used as the host for attempts to introduce various plasmid DNAs. Two plasmids could be introduced into UV1: pRF29 and pLAFR5. A cosmid library of IGTS8 DNA was constructed in pLAFR5 and was electroporated into UV1. Of over 2000 colonies tested three bulk batches, one flask of about 600 clones produced a fluorescent product from DBT. These are being screened to determine if one of these represents a clone that complements the DBT negative phenotype of the UV1 mutant. We obtained chloramphenicol resistant Thiobacillus ferrooxidans after electroporation but these transformants contained no plasmid or transposon sequences, so that insertion of DNA into T. ferrooxidans had not occurred.

  1. Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxygenated fatty acids are useful as specialty chemicals, plasticizers, and biomedicals. Microbial enzymes convert fatty acids to mono-, di-, and trihydroxy fatty acid products. Among them, Bacillus megaterium ALA2 converted n-6 and n-3 PUFAs to many new oxygenated fatty acids. Linoleic acid was ...

  2. Occurrence of a 2-bp (AT) deletion allele and a nonsense (G-to-T) mutant allele at the E2 (DBT) locus of six patients with maple syrup urine disease: Multiple-exon skipping as a secondary effect of the mutations

    SciTech Connect

    Fisher, C.W.; Fisher, C.R.; Chuang, J.L.; Lau, K.S.; Chuang, D.T.; Cox, R.P. )

    1993-02-01

    The authors have identified two novel mutant alleles in the transacylase (E2) gene of the human branched-chain [alpha]-keto acid dehydrogenase (BCKAD) complex in 6 of 38 patients with maple syrup urine disease (MSUD). One mutation, a 2-bp (AT) deletion in exon 2 of the E2 gene, causes a frameshift downstream of residue ([minus]26) in the mitochondrial targeting presequence. The second mutation, a G-to-T transversion in exon 6 of the E2 gene, produces a premature stop codon at Glu-163 (E163*). Transfection of constructs harboring the E163* mutation into an E2-deficient MSUD cell line produced a truncated E2 subunit. However, this mutant E2 chain is unable to assemble into a 24-mer cubic structure and is degraded in the cell. The 2-bp (AT) deletion and the E163* mutant alleles occur in either the homozygous or compound-heterozygous state in the 6 of 38 unrelated MSUD patients studied. Moreover, an array of precise single- and multiple-exon deletions were observed in many amplified E2 mutant cDNAs. The latter results appear to represent secondary effects on RNA processing that are associated with the MSUD mutations at the E2 locus. 30 refs., 8 figs.

  3. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  4. Amino Acid Metabolism Disorders

    MedlinePlus

    ... defects & other health conditions > Amino acid metabolism disorders Amino acid metabolism disorders E-mail to a friend Please ... baby’s newborn screening may include testing for certain amino acid metabolism disorders. These are rare health conditions that ...

  5. Plasma amino acids

    MedlinePlus

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  6. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... of the cells in the stomach to release acid. The stomach contents are then removed and analyzed. ... 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour in ...

  7. Azelaic Acid Topical

    MedlinePlus

    Azelaic acid gel is used to clear the bumps, lesions, and swelling caused by rosacea (a skin disease that ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat acne. Azelaic acid ...

  8. Facts about Folic Acid

    MedlinePlus

    ... Information For... Media Policy Makers Facts About Folic Acid Language: English Español (Spanish) Recommend on Facebook Tweet ... of the baby's brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  9. Acid Lipase Disease

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS NINDS Acid Lipase Disease Information Page Synonym(s): Cholesterol Ester Storage ... Trials Related NINDS Publications and Information What is Acid Lipase Disease ? Acid lipase disease or deficiency occurs ...

  10. Chemical and biological assessment of Angelica herbal decoction: comparison of different preparations during historical applications.

    PubMed

    Zhang, Wendy Li; Zheng, Ken Yu-Zhong; Zhu, Kevin Yue; Zhan, Janis Ya-Xian; Bi, Cathy Wen-Chuan; Chen, Jian-Ping; Du, Crystal Ying-Qing; Zhao, Kui-Jun; Lau, David Tai-Wai; Dong, Tina Ting-Xia; Tsim, Karl Wah-Keung

    2012-08-15

    The commonly used Angelica herbal decoction today is Danggui Buxue Tang (DBT), which is a dietary supplement in treating menopausal irregularity in women, i.e. to nourish "Qi" and to enrich "Blood". According to historical record, many herbal decoctions were also named DBT, but the most popular formulation of DBT was written in Jin dynasty (1247 AD) of China, which contained Astragali Radix (AR) and Angelicae Sinensis Radix (ASR) with a weight ratio of 5:1. However, at least two other Angelica herbal decoctions recorded as DBT were prescribed in Song (1155 AD) and Qing dynasties (1687 AD). Although AR and ASR are still the major components in the DBT herbal decoctions, they are slightly varied in the herb composition. In order to reveal the efficiency of different Angelica herbal decoctions, the chemical and biological properties of three DBT herbal extracts were compared. Significantly, the highest amounts of AR-derived astragaloside III, astragaloside IV, calycosin and formononetin and ASR-derived ferulic acid were found in DBT described in 1247 AD: this preparation showed stronger activities in osteogenic, estrogenic and erythropoetic effects than the other two DBT. The current results supported the difference of three DBT in chemical and biological properties, which could be a result of different herbal combinations. For the first time, this study supports the popularity of DBT described in 1247 AD. PMID:22902230

  11. Folic acid - test

    MedlinePlus

    ... folic acid measurements include: Alcohol Aminosalicylic acid Birth control pills Estrogens Tetracyclines Ampicillin Chloramphenicol Erythromycin Methotrexate Penicillin Aminopterin Phenobarbital Phenytoin Drugs to treat malaria

  12. Oxalic acid poisoning

    MedlinePlus

    Symptoms of oxalic acid poisoning include: Abdominal pain Burns and blisters where the acid contacted the skin Collapse Convulsions Mouth pain Shock Throat pain Tremors (unintentional trembling) Vomiting

  13. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  14. Microbial extraction of sulfur from model coal organosulfur compounds

    SciTech Connect

    Purdy, R.F.; Ward, B.; Lepo, J.E.

    1991-12-31

    Several hundred bacterial cultures isolated from a variety of natural sites were screened for their ability to desulfurize the model coal organosulfur compounds, dibenzothiophene (DBT) and DBT-sulfone. A sulfur-stress assay, in which DBT-sulfone was the only bioavailable source of sulfur, was used to screen and select for organisms that selectively desulfurized the organic-sulfur substrate. Only two new isolates, UMX9 and UMX3, and strain IGTS-8, a Rhodococcus rhodochrous provided by the Institute for Gas Technology (Chicago, USA.) as a reference culture, would grow on DBT or DBT-sulfone as a sole source of sulfur. Under sulfur-stress conditions, a desulfurized product identified as 2-hydroxybiphenyl (2-phenylphenol) was detected only for UMX9 and IGTS-8. Biodesulfurization activity for all three organisms occurred only for growing cultures, and was depressed by free sulfate, although more so for UMX3 and IGTS-8 than for UMX9. None of the three cultures exhibited good growth on DBT, DBT-sulfone, or 2-phenylphenol as sole sources of carbon. Taxonomic studies revealed UMX3 to be similar to IGTS-8, whereas UMX9 only exhibited Rhodococcus-like features. Comparative tests for carbohydrate utilization revealed that only UMX9 would grow on glucose, and that only IGTS-8 would grow on L-arabinose. Assays of biodesulfurization activity as a function of temperature or pH revealed further differences between UMX9 and UMX3/IGTS-8. Under optimized assay conditions for each organism, UMX9 exhibited up to 30% greater biodesulfurization activity than did IGTS-8 and UMX3, which were similar in activity.

  15. Acid tolerance in amphibians

    SciTech Connect

    Pierce, B.A.

    1985-04-01

    Studies of amphibian acid tolerance provide information about the potential effects of acid deposition on amphibian communities. Amphibians as a group appear to be relatively acid tolerant, with many species suffering increased mortality only below pH 4. However, amphibians exhibit much intraspecific variation in acid tolerance, and some species are sensitive to even low levels of acidity. Furthermore, nonlethal effects, including depression of growth rates and increases in developmental abnormalities, can occur at higher pH.

  16. Toxicity of adipic acid.

    PubMed

    Kennedy, Gerald L

    2002-05-01

    Adipic acid has very low acute toxicity in rats with an LD50 > 5000 mg/kg. Adipic acid produced mild to no skin irritation on intact guinea pig skin as a 50% concentration in propylene glycol; it was not a skin sensitizer. Adipic acid caused mild conjunctival irritation in washed rabbit eyes; in unwashed rabbit eyes, there was mild conjunctival irritation, minimal iritis, but no corneal effects. Adipic acid dust may irritate the mucous membranes of the lungs and nose. In a 2-year feeding study, rats fed adipic acid at concentrations up to 5% in the diet exhibited only weight loss. Adipic acid is not genetically active in a wide variety of assay systems. Adipic acid caused no developmental toxicity in mice, rats, rabbits, or hamsters when administered orally. Adipic acid is partially metabolized in humans; the balance is eliminated unchanged in the urine. Adipic acid is slightly to moderately toxic to fish, daphnia, and algae in acute tests. PMID:12024802

  17. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  18. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    This communication notes the actual magnitude of the acidity in acidic fog particles and suggests a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air.

  19. Proteomics and Metabolomics Analyses to Elucidate the Desulfurization Pathway of Chelatococcus sp.

    PubMed

    Bordoloi, Naba K; Bhagowati, Pabitra; Chaudhuri, Mihir K; Mukherjee, Ashis K

    2016-01-01

    Desulfurization of dibenzothiophene (DBT) and alkylated DBT derivatives present in transport fuel through specific cleavage of carbon-sulfur (C-S) bonds by a newly isolated bacterium Chelatococcus sp. is reported for the first time. Gas chromatography-mass spectrometry (GC-MS) analysis of the products of DBT degradation by Chelatococcus sp. showed the transient formation of 2-hydroxybiphenyl (2-HBP) which was subsequently converted to 2-methoxybiphenyl (2-MBP) by methylation at the hydroxyl group of 2-HBP. The relative ratio of 2-HBP and 2-MBP formed after 96 h of bacterial growth was determined at 4:1 suggesting partial conversion of 2-HBP or rapid degradation of 2-MBP. Nevertheless, the enzyme involved in this conversion process remains to be identified. This production of 2-MBP rather than 2-HBP from DBT desulfurization has a significant metabolic advantage for enhancing the growth and sulfur utilization from DBT by Chelatococcus sp. and it also reduces the environmental pollution by 2-HBP. Furthermore, desulfurization of DBT derivatives such as 4-M-DBT and 4, 6-DM-DBT by Chelatococcus sp. resulted in formation of 2-hydroxy-3-methyl-biphenyl and 2-hydroxy -3, 3/- dimethyl-biphenyl, respectively as end product. The GC and X-ray fluorescence studies revealed that Chelatococcus sp. after 24 h of treatment at 37°C reduced the total sulfur content of diesel fuel by 12% by per gram resting cells, without compromising the quality of fuel. The LC-MS/MS analysis of tryptic digested intracellular proteins of Chelatococcus sp. when grown in DBT demonstrated the biosynthesis of 4S pathway desulfurizing enzymes viz. monoxygenases (DszC, DszA), desulfinase (DszB), and an NADH-dependent flavin reductase (DszD). Besides, several other intracellular proteins of Chelatococcus sp. having diverse biological functions were also identified by LC-MS/MS analysis. Many of these enzymes are directly involved with desulfurization process whereas the other enzymes/proteins support growth

  20. Proteomics and Metabolomics Analyses to Elucidate the Desulfurization Pathway of Chelatococcus sp.

    PubMed Central

    Chaudhuri, Mihir K.

    2016-01-01

    Desulfurization of dibenzothiophene (DBT) and alkylated DBT derivatives present in transport fuel through specific cleavage of carbon-sulfur (C-S) bonds by a newly isolated bacterium Chelatococcus sp. is reported for the first time. Gas chromatography-mass spectrometry (GC-MS) analysis of the products of DBT degradation by Chelatococcus sp. showed the transient formation of 2-hydroxybiphenyl (2-HBP) which was subsequently converted to 2-methoxybiphenyl (2-MBP) by methylation at the hydroxyl group of 2-HBP. The relative ratio of 2-HBP and 2-MBP formed after 96 h of bacterial growth was determined at 4:1 suggesting partial conversion of 2-HBP or rapid degradation of 2-MBP. Nevertheless, the enzyme involved in this conversion process remains to be identified. This production of 2-MBP rather than 2-HBP from DBT desulfurization has a significant metabolic advantage for enhancing the growth and sulfur utilization from DBT by Chelatococcus sp. and it also reduces the environmental pollution by 2-HBP. Furthermore, desulfurization of DBT derivatives such as 4-M-DBT and 4, 6-DM-DBT by Chelatococcus sp. resulted in formation of 2-hydroxy-3-methyl-biphenyl and 2-hydroxy –3, 3/- dimethyl-biphenyl, respectively as end product. The GC and X-ray fluorescence studies revealed that Chelatococcus sp. after 24 h of treatment at 37°C reduced the total sulfur content of diesel fuel by 12% by per gram resting cells, without compromising the quality of fuel. The LC-MS/MS analysis of tryptic digested intracellular proteins of Chelatococcus sp. when grown in DBT demonstrated the biosynthesis of 4S pathway desulfurizing enzymes viz. monoxygenases (DszC, DszA), desulfinase (DszB), and an NADH-dependent flavin reductase (DszD). Besides, several other intracellular proteins of Chelatococcus sp. having diverse biological functions were also identified by LC-MS/MS analysis. Many of these enzymes are directly involved with desulfurization process whereas the other enzymes/proteins support

  1. [Amino acids in saliva].

    PubMed

    Klinger, G; Gruhn, K

    1984-01-01

    Total amino acids in saliva and free and peptide-bound amino acids from 21 saliva samples were determined. The contents of amino acids was 25 mmol/1; total nitrogen content was 78-80 mmol/1. Amino acids consist of Prolin in 25%. Some patients were examined before and after application of the depot estrogen ethinyl estradiosulfonat, which stimulates the assimilation of protein. After application, amino acids increased and the authors found a shift between the single amino acids. Estrogen medication induced an increase in proteins with the character of collagens. Clinical effects are discussed. (author's modified) PMID:6240853

  2. Enzymatic desulfurization of coal: Third quarterly report

    SciTech Connect

    Marquis, J.K.; Kitchell, J.P.

    1989-03-14

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ''model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix. In this quarter we obtained important results both with the development of our understanding of the enzyme reaction systems and also with the microbial work at Woods Hole. 12 figs., 11 tabs.

  3. Hydrochloric acid poisoning

    MedlinePlus

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, ... discusses poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  4. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount ... the blood in people with very high triglycerides. Omega-3 fatty acids are in a class of medications ...

  5. Omega-6 Fatty Acids

    MedlinePlus

    Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant seed, borage seed, ...

  6. Zoledronic Acid Injection

    MedlinePlus

    Zoledronic acid (Reclast) is used to prevent or treat osteoporosis (condition in which the bones become thin and weak ... of life,' end of regular menstrual periods). Zoledronic acid (Reclast) is also used to treat osteoporosis in ...

  7. Aminolevulinic Acid Topical

    MedlinePlus

    Aminolevulinic acid is used in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty ... skin cancer) of the face or scalp. Aminolevulinic acid is in a class of medications called photosensitizing ...

  8. Acid-fast stain

    MedlinePlus

    The acid-fast stain is a laboratory test that determines if a sample of tissue, blood, or other body ... dye. The slide is then washed with an acid solution and a different stain is applied. Bacteria ...

  9. Uric acid - blood

    MedlinePlus

    Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in some ... dried beans and peas, and beer. Most uric acid dissolves in blood and travels to the kidneys. ...

  10. Hydrochloric acid poisoning

    MedlinePlus

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, such ... poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  11. Omega-6 Fatty Acids

    MedlinePlus

    ... types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean ... from studying specific omega-6 fatty acids or plant oils containing omega-6 fatty acids. See the separate ...

  12. Uric Acid Test

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? Uric Acid Share this page: Was this page helpful? Also known as: Serum Urate; UA Formal name: Uric Acid Related tests: Synovial Fluid Analysis , Kidney Stone Analysis , ...

  13. Acid-fast stain

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003766.htm Acid-fast stain To use the sharing features on this page, please enable JavaScript. The acid-fast stain is a laboratory test that determines ...

  14. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  15. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  16. Methylmalonic Acid Test

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? Methylmalonic Acid Share this page: Was this page helpful? Also known as: MMA Formal name: Methylmalonic Acid Related tests: Vitamin B12 and Folate , Homocysteine , Intrinsic ...

  17. Fatty acid analogs

    DOEpatents

    Elmaleh, David R.; Livni, Eli

    1985-01-01

    In one aspect, a radioactively labeled analog of a fatty acid which is capable of being taken up by mammalian tissue and which exhibits an in vivo beta-oxidation rate below that with a corresponding radioactively labeled fatty acid.

  18. Boric acid poisoning

    MedlinePlus

    ... boric acid poisoning usually occurs when someone swallows powdered roach-killing products that contain the chemical. Chronic ... vein (IV) Medicines to treat symptoms Note: Activated charcoal does not effectively treat (absorb) boric acid. For ...

  19. Lactic acid test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003507.htm Lactic acid test To use the sharing features on this page, please enable JavaScript. Lactic acid is mainly produced in muscle cells and red ...

  20. Molecular biological enhancement of coal desulfurization: Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae

    SciTech Connect

    Krawiec, S.

    1991-11-09

    This department of energy-sponsored mission-oriented research project currently has three emphases. They are: (1) determining the kinetics of monohydroxybiphenyl (OH-BP) production in batch culture by N1-36, an unidentified soil isolate, when the organism is presented with dibenzothiophene (DBT) or dibenzosulfone (DBTO{sub 2}); (2) establishing reliable methods for physically characterizing R68.45, a broad host range plasmid; and (3) attempting to elicit a physiologically consistent and genetically stable ability of some gram negative soil isolates to convert DBT to o,o{prime}-biphenol. Eachh of these goals has subsidiary components. For example, in addition to establishing kinetics of formation of OH-BP by N1-36, analyses have been or will be performed to determine whether the catalytic activity can be achieved with irradiated cells, spheroplasts, and cell extracts. This report presents information on progress towards fulfilling both the principal goals listed above and some relevant ancillary activities.

  1. Molecular biological enhancement of coal desulfurization: Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae. Ninth quarterly report, [July--October 1991

    SciTech Connect

    Krawiec, S.

    1991-11-09

    This department of energy-sponsored mission-oriented research project currently has three emphases. They are: (1) determining the kinetics of monohydroxybiphenyl (OH-BP) production in batch culture by N1-36, an unidentified soil isolate, when the organism is presented with dibenzothiophene (DBT) or dibenzosulfone (DBTO{sub 2}); (2) establishing reliable methods for physically characterizing R68.45, a broad host range plasmid; and (3) attempting to elicit a physiologically consistent and genetically stable ability of some gram negative soil isolates to convert DBT to o,o{prime}-biphenol. Eachh of these goals has subsidiary components. For example, in addition to establishing kinetics of formation of OH-BP by N1-36, analyses have been or will be performed to determine whether the catalytic activity can be achieved with irradiated cells, spheroplasts, and cell extracts. This report presents information on progress towards fulfilling both the principal goals listed above and some relevant ancillary activities.

  2. Application of Two Cobalt-Based Metal-Organic Frameworks as Oxidative Desulfurization Catalysts.

    PubMed

    Masoomi, Mohammad Yaser; Bagheri, Minoo; Morsali, Ali

    2015-12-01

    Two new porous cobalt-based metal-organic frameworks, [Co6(oba)5(OH)2(H2O)2(DMF)4]n · 5DMF (TMU-10) and [Co3(oba)3(O) (Py)0.5] n · 4DMF · Py (TMU-12) have been synthesized by solvothermal method using a nonlinear dicarboxylate ligand. Under mild reaction conditions, these compounds exhibited good catalytic activity and reusability in oxidative desulfurization (ODS) reaction of model oil which was prepared by dissolving dibenzothiophene (DBT) in n-hexane. FT-IR and Mass analysis showed that the main product of DBT oxidation is its corresponding sulfone, which was adsorbed on the surfaces of catalysts. The activation energy was obtained as 13.4 kJ/mol. PMID:26571113

  3. Oxidative desulfurization of fuel oil by pyridinium-based ionic liquids.

    PubMed

    Zhao, Dishun; Wang, Yanan; Duan, Erhong

    2009-01-01

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF(4) was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF(4) has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H(2)O(2)) = 1:1:0.4, temperature 55 degrees C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration. PMID:19924069

  4. PRODUCTION OF TRIFLUOROACETIC ACID

    DOEpatents

    Haworth, W.N.; Stacey, M.

    1949-07-19

    A method is given for the production of improved yields of trifluoroacetic acid. The compound is prepared by oxidizing m-aminobenzotrifluoride with an alkali metal or alkaline earth metal permanganate at a temperature in the range of 80 deg C to 100 deg C while dissolved ln a mixture of water with glacial acetic acid and/or trifluoroacetic acid. Preferably a mixture of water and trifluoroacetic acid ls used as the solvent.

  5. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  6. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    The chemical composition of fog particles has become of considerable interest, because of both the possibility of interpreting atmospheric- chemistry processes in fog particles in terms of the principles of aqueous chemistry and the potential health effects of species present in fog particles. The acidity of fog particles has received wide attention. This communication noted the actual magnitude of the excess acidity in acidic fog particles and suggested a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air. (DP)

  7. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  8. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  9. Acid Rain Study Guide.

    ERIC Educational Resources Information Center

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  10. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…

  11. IMMUNE FUNCTION IN ADULT RATS EXPOSED TO DBT IN DRINKING WATER

    EPA Science Inventory

    Organotins are used commercially as agricultural pesticides, antifouling agents and stabilizers for polyvinyl chloride (PVC) pipe. Mono- and di-substituted methyl and butyltins, used in PVC pipe production, are of concern to the USEPA as they leach from supply pipes into drinking...

  12. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor L.; Brow, Mary Ann D.; Dahlberg, James E.

    2007-12-11

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  13. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  14. Editorial: Acid precipitation

    SciTech Connect

    1995-09-01

    This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.

  15. Cleavage of nucleic acids

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow; Mary Ann D.; Dahlberg, James E.

    2010-11-09

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  16. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    2000-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  17. Nucleic acid detection assays

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.

    2005-04-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  18. Nucleic acid detection compositions

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James L.

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  19. Acidic Ionic Liquids.

    PubMed

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition. PMID:27175515

  20. Nucleic acid detection kits

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  1. Demospongic Acids Revisited

    PubMed Central

    Kornprobst, Jean-Michel; Barnathan, Gilles

    2010-01-01

    The well-known fatty acids with a Δ5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16–C32) and from some terrestrial plants with short acyl chains (C18–C19). Finally, the Δ5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs). This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between Δ5,9 fatty acids and other NMI FAs. PMID:21116406

  2. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  3. Engineering synthetic bacterial consortia for enhanced desulfurization and revalorization of oil sulfur compounds.

    PubMed

    Martínez, Igor; Mohamed, Magdy El-Said; Rozas, Daniel; García, José Luis; Díaz, Eduardo

    2016-05-01

    The 4S pathway is the most studied bioprocess for the removal of the recalcitrant sulfur of aromatic heterocycles present in fuels. It consists of three sequential functional units, encoded by the dszABCD genes, through which the model compound dibenzothiophene (DBT) is transformed into the sulfur-free 2-hydroxybiphenyl (2HBP) molecule. In this work, a set of synthetic dsz cassettes were implanted in Pseudomonas putida KT2440, a model bacterial "chassis" for metabolic engineering studies. The complete dszB1A1C1-D1 cassette behaved as an attractive alternative - to the previously constructed recombinant dsz cassettes - for the conversion of DBT into 2HBP. Refactoring the 4S pathway by the use of synthetic dsz modules encoding individual 4S pathway reactions revealed unanticipated traits, e.g., the 4S intermediate 2HBP-sulfinate (HBPS) behaves as an inhibitor of the Dsz monooxygenases, and once secreted from the cells it cannot be further taken up. That issue should be addressed for the rational design of more efficient biocatalysts for DBT bioconversions. In this sense, the construction of synthetic bacterial consortia to compartmentalize the 4S pathway into different cell factories for individual optimization was shown to enhance the conversion of DBT into 2HBP, overcome the inhibition of the Dsz enzymes by the 4S intermediates, and enable efficient production of unattainable high added value intermediates, e.g., HBPS, that are difficult to obtain using the current monocultures. PMID:26802977

  4. Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae. Tenth quarterly report

    SciTech Connect

    Krawiec, S.

    1992-02-07

    The original conception of the work was that genetic determinants of the sulfoxide/sulfone/sulfonate/sulfate (``4S``) pathway in Pseudomonas spp. would be cloned in vivo and then transferred to Thiobacillus spp. This ambition remains an appealing prospect; however, fulfilling that ambition has been confounded by an instability observed in the DbtS{sup +} phenotype in Pseudomonas spp. But the persisting interest in the phenotype has lead to isolation of fresh strains which have a DbtS{sup +} phenotype. One strain in particular, N1-36, has been the focus of extensive characterizations in long-term cultures. During the present quarter, seven cultures maintained in a ``fermentor`` for a week or longer have been run to determine rate and extent of growth, extent of conversion of dibenzothiophene (DBT) or dibenzosulfone (DBTO{sub 2}) to monohydroxybiphenyl (OH-BP), effect of pH maintained at 6.0, and the effect of adding glucose to cultures in which the amount of glucose had been diminished by bacterial consumption. In addition, a study of the effectiveness of using R68.445 as a vehicle for in vivo cloning of genes was completed this semester, and introduction of DbtS{sup +} determinants into Thiobacillus spp. continues to be an important goal.

  5. Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae. [Pseudomonas, Thiobacillus, Rhodococcus

    SciTech Connect

    Krawiec, S.

    1992-02-07

    The original conception of the work was that genetic determinants of the sulfoxide/sulfone/sulfonate/sulfate ( 4S'') pathway in Pseudomonas spp. would be cloned in vivo and then transferred to Thiobacillus spp. This ambition remains an appealing prospect; however, fulfilling that ambition has been confounded by an instability observed in the DbtS{sup +} phenotype in Pseudomonas spp. But the persisting interest in the phenotype has lead to isolation of fresh strains which have a DbtS{sup +} phenotype. One strain in particular, N1-36, has been the focus of extensive characterizations in long-term cultures. During the present quarter, seven cultures maintained in a fermentor'' for a week or longer have been run to determine rate and extent of growth, extent of conversion of dibenzothiophene (DBT) or dibenzosulfone (DBTO{sub 2}) to monohydroxybiphenyl (OH-BP), effect of pH maintained at 6.0, and the effect of adding glucose to cultures in which the amount of glucose had been diminished by bacterial consumption. In addition, a study of the effectiveness of using R68.445 as a vehicle for in vivo cloning of genes was completed this semester, and introduction of DbtS{sup +} determinants into Thiobacillus spp. continues to be an important goal.

  6. Crystal structure of DszC from Rhodococcus sp. XP at 1.79 Å.

    PubMed

    Liu, Shiheng; Zhang, Conggang; Su, Tiantian; Wei, Tiandi; Zhu, Deyu; Wang, Kang; Huang, Yan; Dong, Yuhui; Yin, Kun; Xu, Sujuan; Xu, Ping; Gu, Lichuan

    2014-09-01

    The dibenzothiophene (DBT) monooxygenase DszC, which is the key initiating enzyme in "4S" metabolic pathway, catalyzes sequential sulphoxidation reaction of DBT to DBT sulfoxide (DBTO), then DBT sulfone (DBTO2). Here, we report the crystal structure of DszC from Rhodococcus sp. XP at 1.79 Å. Intriguingly, two distinct conformations occur in the flexible lid loops adjacent to the active site (residue 280-295, between α9 and α10). They are named "open"' and "closed" state respectively, and might show the status of the free and ligand-bound DszC. The molecular docking results suggest that the reduced FMN reacts with an oxygen molecule at C4a position of the isoalloxazine ring, producing the C4a-(hydro)peroxyflavin intermediate which is stabilized by H391 and S163. H391 may contribute to the formation of the C4a-(hydro)peroxyflavin by acting as a proton donor to the proximal peroxy oxygen, and it might also be involved in the protonation process of the C4a-(hydro)xyflavin. Site-directed mutagenesis study shows that mutations in the residues involved either in catalysis or in flavin or substrate-binding result in a complete loss of enzyme activity, suggesting that the accurate positions of flavin and substrate are crucial for the enzyme activity. PMID:24470304

  7. Microorganisms for producing organic acids

    SciTech Connect

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  8. Acid-Base Homeostasis

    PubMed Central

    Nakhoul, Nazih; Hering-Smith, Kathleen S.

    2015-01-01

    Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3− and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3− is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys. PMID:26597304

  9. Citric Acid Alternative to Nitric Acid Passivation

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  10. USGS Tracks Acid Rain

    USGS Publications Warehouse

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  11. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  12. Recovery of organic acids

    SciTech Connect

    Verser, Dan W.; Eggeman, Timothy J.

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  13. THIN-LAYER SEPARATION OF CITRIC ACID CYCLE INTERMEDIATES, LACTIC ACID, AND THE AMINO ACID TAURINE

    EPA Science Inventory

    This paper describes a two-dimensional mixed-layer method for separating citric acid cycle intermediates, lactic acid and the amino acid taurine. The method cleanly separates all citric acid cycle intermediates tested, excepting citric acid and isocitric acid. The solvents are in...

  14. Toxicology of Perfluoroalkyl acids

    EPA Science Inventory

    The Perfluoroalkyl acids(PFAAs) area a family of organic chemicals consisting of a perflurinated carbon backbone (4-12in length) and a acidic functional moiety (Carboxylate or sulfonate). These compounds have excellent surface-tension reducing properties and have numerous industr...

  15. Toxicology of Perfluoroalkyl Acids*

    EPA Science Inventory

    The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-12 in length) and an acidic functional moiety (carboxylate or sulfonate). These compounds are chemically stable, have excellent surface-tension reducing properties...

  16. Lead-acid cell

    SciTech Connect

    Hradcovsky, R.J.; Kozak, O.R.

    1980-12-09

    A lead-acid storage battery is described that has a lead negative electrode, a lead dioxide positive electrode and a sulfuric acid electrolyte having an organic catalyst dissolved therein which prevents dissolution of the electrodes into lead sulfate whereby in the course of discharge, the lead dioxide is reduced to lead oxide and the lead is oxidized.

  17. Proteins and Amino Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the most abundant substances in living organisms and cells. All proteins are constructed from the same twenty amino acids that are linked together by covalent bonds. Shorter chains of two or more amino acids can be linked by covalent bonds to form polypeptides. There are twenty amino...

  18. EFFECTS OF ACID PRECIPITATION

    EPA Science Inventory

    Recent reviews of available data indicate that precipitation in a large region of North America is highly acidic when its pH is compared with the expected pH value of 5.65 for pure rain water in equilibrium with CO2. A growing body of evidence suggests that acid rain is responsib...

  19. Bile acid transporters

    PubMed Central

    Dawson, Paul A.; Lan, Tian; Rao, Anuradha

    2009-01-01

    In liver and intestine, transporters play a critical role in maintaining the enterohepatic circulation and bile acid homeostasis. Over the past two decades, there has been significant progress toward identifying the individual membrane transporters and unraveling their complex regulation. In the liver, bile acids are efficiently transported across the sinusoidal membrane by the Na+ taurocholate cotransporting polypeptide with assistance by members of the organic anion transporting polypeptide family. The bile acids are then secreted in an ATP-dependent fashion across the canalicular membrane by the bile salt export pump. Following their movement with bile into the lumen of the small intestine, bile acids are almost quantitatively reclaimed in the ileum by the apical sodium-dependent bile acid transporter. The bile acids are shuttled across the enterocyte to the basolateral membrane and effluxed into the portal circulation by the recently indentified heteromeric organic solute transporter, OSTα-OSTβ. In addition to the hepatocyte and enterocyte, subgroups of these bile acid transporters are expressed by the biliary, renal, and colonic epithelium where they contribute to maintaining bile acid homeostasis and play important cytoprotective roles. This article will review our current understanding of the physiological role and regulation of these important carriers. PMID:19498215

  20. Fats and fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The absolute fat requirement of the human species is the amount of essential fatty acids needed to maintain optimal fatty acid composition of all tissues and normal eicosanoid synthesis. At most, this requirement is no more than about 5% of an adequate energy intake. However, fat accounts for appro...

  1. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  2. EXPOSURES TO ACIDIC AEROSOLS

    EPA Science Inventory

    Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...

  3. Mutant fatty acid desaturase

    DOEpatents

    Shanklin, John; Cahoon, Edgar B.

    2004-02-03

    The present invention relates to a method for producing mutants of a fatty acid desaturase having a substantially increased activity towards fatty acid substrates with chains containing fewer than 18 carbons relative to an unmutagenized precursor desaturase having an 18 carbon atom chain length substrate specificity. The method involves inducing one or more mutations in the nucleic acid sequence encoding the precursor desaturase, transforming the mutated sequence into an unsaturated fatty acid auxotroph cell such as MH13 E. coli, culturing the cells in the absence of supplemental unsaturated fatty acids, thereby selecting for recipient cells which have received and which express a mutant fatty acid desaturase with an elevated specificity for fatty acid substrates having chain lengths of less than 18 carbon atoms. A variety of mutants having 16 or fewer carbon atom chain length substrate specificities are produced by this method. Mutant desaturases produced by this method can be introduced via expression vectors into prokaryotic and eukaryotic cells and can also be used in the production of transgenic plants which may be used to produce specific fatty acid products.

  4. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat-like ... people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...

  5. Salicylic Acid Topical

    MedlinePlus

    Propa pH® Peel-Off Acne Mask ... pimples and skin blemishes in people who have acne. Topical salicylic acid is also used to treat ... medications called keratolytic agents. Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked ...

  6. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  7. Trans Fatty Acids

    NASA Astrophysics Data System (ADS)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  8. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  9. Strongly Acidic Auxin Indole-3-Methanesulfonic Acid

    PubMed Central

    Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

    1985-01-01

    A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles. PMID:16664007

  10. Understanding acid rain

    SciTech Connect

    Budiansky, S.

    1981-06-01

    The complexities of the phenomenon of acid rain are described. Many factors, including meteorology, geology, chemistry, and biology, all play parts. Varying weather, varying soils, the presence of other pollutants and species differences all act to blur the connections between industrial emissions, acid rain, and environmental damage. Some experts believe that the greatest pH shock to lakes occurs during snow melt and runoff in the spring; others believe that much of the plant damage ascribed to acid rain is actually due to the effects of ozone. Much work needs to be done in the area of sampling. Historical data are lacking and sampling methods are not sufficiently accurate. (JMT)

  11. Molecular biological enhancement of coal desulfurization. Final report

    SciTech Connect

    Krawiec, S.

    1994-12-31

    During the period from 1986 through 1993 the prospect of bacterial desulfurization of fossil fuel was transformed from a theoretically appealing concept to a demonstrable laboratory phenomenon. Results from several laboratories confirmed that there was not one but, rather, several metabolic bases of selectively removing sulfur from the carbon frame of sulfur-containing organic compounds characteristic of fossil fuels. Results in this report relate solely to the so-called ``4S`` pathway (named for the four sulfur-containing compounds in the sequence: (l) dibenzothiophene [DBT] {yields} (2) dibenzothiophene sulfoxide [DBTO] {yields} (3) dibenzosulfone [DBTO{sup 2}] {yields} (4) dibenzosulfonate {yields} monohydroxybiphenyl [OH-BP] + SO{sub 4}{sup =}. [An additional desulfurized product, biphenyl, has been hypothesized and another, o,o{prime}-biphenyl, observed.]) The following subjects are discussed: isolating bacteria with a DbtS{sup +} phenotype; confirming the production of a desulfurized product; determining the identity of the isolates; determining the growth characteristics of the isolates in batch and continuous cultures; determining the kinetics and yields of product in batch and continuous cultures.

  12. WASTE ACID DETOXIFICATION AND RECLAMATION

    EPA Science Inventory

    This Environmental Security Technology Certification Program (ESTCP) project demonstrated the Waste Acid Detoxification and Reclamation (WADR) systems ability to recover waste electropolish acid solutions generated during the manufacturing of gun-tubes, and reuse the clean acid. ...

  13. Disorders of Amino Acid Metabolism

    MedlinePlus

    ... Aspiration Syndrome Additional Content Medical News Disorders of Amino Acid Metabolism By Lee M. Sanders, MD, MPH NOTE: ... Metabolic Disorders Disorders of Carbohydrate Metabolism Disorders of Amino Acid Metabolism Disorders of Lipid Metabolism Amino acids are ...

  14. Acid soldering flux poisoning

    MedlinePlus

    The harmful substances in soldering fluxes are called hydrocarbons. They include: Ammonium chloride Rosin Hydrochloric acid Zinc ... Lee DC. Hydrocarbons. In: Marx JA, Hockberger RS, Walls RM, et ... Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ...

  15. Aminolevulinic Acid Topical

    MedlinePlus

    ... in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty or scaly ... photosensitizing agents. When aminolevulinic acid is activated by light, it damages the cells of actinic keratosis lesions.

  16. Difficult Decisions: Acid Rain.

    ERIC Educational Resources Information Center

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  17. Uric acid - urine

    MedlinePlus

    ... to filter fluids and waste normally (chronic glomerulonephritis ) Lead poisoning Long-term (chronic) alcohol use Risks There are ... Elsevier Saunders; 2011:chap 28. Read More Gout Lead poisoning Liver disease Polycythemia vera Uric acid - blood Update ...

  18. Amoxicillin and Clavulanic Acid

    MedlinePlus

    ... is used to treat certain infections caused by bacteria, including infections of the ears, lungs, sinus, skin, ... antibiotics. It works by stopping the growth of bacteria. Clavulanic acid is in a class of medications ...

  19. Hydrofluoric acid poisoning

    MedlinePlus

    Chemical Emergencies: Case Definition: Hydrofluoric Acid . Centers for Disease Control and Prevention, U.S. Dept of Health and Human Services; 2005. Goldfrank LR, ed. Goldfrank's Toxicologic Emergencies . 8th ed. New ...

  20. Lead/acid batteries

    NASA Astrophysics Data System (ADS)

    Bullock, Kathryn R.

    Lead/acid batteries are produced in sizes from less than 1 to 3000 Ah for a wide variety of portable, industrial and automotive applications. Designs include Planté, Fauré or pasted, and tubular electrodes. In addition to the traditional designs which are flooded with sulfuric acid, newer 'valve-regulated" designs have the acid immolibized in a silica gel or absorbed in a porous glass separator. Development is ongoing worldwide to increase the specific power, energy and deep discharge cycle life of this commercially successful system to meet the needs of new applications such as electric vehicles, load leveling, and solar energy storage. The operating principles, current status, technical challenges and commercial impact of the lead/acid battery are reviewed.

  1. Citric acid urine test

    MedlinePlus

    ... used to diagnose renal tubular acidosis and evaluate kidney stone disease. ... tubular acidosis and a tendency to form calcium kidney stones. The following may decrease urine citric acid levels: ...

  2. Pantothenic acid and biotin

    MedlinePlus

    ... JavaScript. Pantothenic acid and biotin are types of B vitamins. They are water-soluble, which means that the ... found in foods that are good sources of B vitamins, including the following: Animal proteins Avocado Broccoli, kale, ...

  3. (Acid rain workshop)

    SciTech Connect

    Turner, R.S.

    1990-12-05

    The traveler presented a paper entitled Susceptibility of Asian Ecosystems to Soil-Mediated Acid Rain Damage'' at the Second Workshop on Acid Rain in Asia. The workshop was organized by the Asian Institute of Technology (Bangkok, Thailand), Argonne National Laboratory (Argonne, Illinois), and Resource Management Associates (Madison, Wisconsin) and was sponsored by the US Department of Energy, the United Nations Environment Program, the United Nations Economic and Social Commission for Asia and the Pacific, and the World Bank. Papers presented on the first day discussed how the experience gained with acid rain in North America and Europe might be applied to the Asian situation. Papers describing energy use projections, sulfur emissions, and effects of acid rain in several Asian countries were presented on the second day. The remaining time was allotted to discussion, planning, and writing plans for a future research program.

  4. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... The test is done after you have not eaten for a while so fluid is all that remains in ... injected into your body. This is done to test the ability of the cells in the stomach ...

  5. Deoxycholic Acid Injection

    MedlinePlus

    ... severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a ... as a liquid to be injected subcutaneously (just under the skin) by a doctor. Your doctor will ...

  6. Amino Acids and Chirality

    NASA Technical Reports Server (NTRS)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  7. Valproic Acid and Pregnancy

    MedlinePlus

    ... in the treatment of epilepsy, and to treat bipolar disorder and migraines. I have been taking valproic acid ... that women with seizure disorders and women with bipolar disorder might have menstrual problems and difficulty getting pregnant. ...

  8. Amino Acid Metabolism Disorders

    MedlinePlus

    Metabolism is the process your body uses to make energy from the food you eat. Food is ... One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup ...

  9. Uric acid - blood

    MedlinePlus

    ... High levels of uric acid can sometimes cause gout or kidney disease. You may have this test ... Alcoholism Chemotherapy-related side effects Diabetes Excessive exercise Gout Hypoparathyroidism Lead poisoning Leukemia Medullary cystic kidney disease ...

  10. Citric acid urine test

    MedlinePlus

    ... The test is used to diagnose renal tubular acidosis and evaluate kidney stone disease. Normal Results The ... level of citric acid may mean renal tubular acidosis and a tendency to form calcium kidney stones. ...

  11. Folic Acid Quiz

    MedlinePlus

    ... more easily than natural food folate. Close × Answer: D CORRECT: Folic acid reduces the risk for spina ... g., orange juice and green vegetables). Close × Answer: D CORRECT: Spina bifida and anencephaly are neural tube ...

  12. Folic acid in diet

    MedlinePlus

    ... green leafy vegetables Dried beans and peas (legumes) Citrus fruits and juices Fortified means that vitamins have ... A.D.A.M. Editorial team. Related MedlinePlus Health Topics Folic Acid Browse the Encyclopedia A.D. ...

  13. Amoxicillin and Clavulanic Acid

    MedlinePlus

    ... Amoxicillin is in a class of medications called penicillin-like antibiotics. It works by stopping the growth ... allergic to amoxicillin (Amoxil, Trimox, Wymox), clavulanic acid, penicillin, cephalosporins, or any other medications.tell your doctor ...

  14. Boric Acid Poisoning

    PubMed Central

    Wong, L. C.; Heimbach, M. D.; Truscott, D. R.; Duncan, B. D.

    1964-01-01

    Boric acid poisoning in 11 infants, occurring in the newborn nursery as a result of the accidental and inadvertent use of 2.5% boric acid in the preparation of the formulae, is reported. Five of the infants died. All except two exhibited the classical symptomatology of acute boric acid poisoning, namely, diarrhea, vomiting, erythema, exfoliation, desquamation of the skin, and marked central nervous system irritation. Early manifestations of poisoning were nonspecific, and one patient died before skin manifestations were noted. Peritoneal dialysis, instituted in nine cases, was found to be the most effective method of treatment. It is recommended that boric acid, which is of doubtful therapeutic value, should be completely removed from hospitals, dispensaries and pharmacopoeias. ImagesFig. 1Fig. 2 PMID:14166459

  15. Polymers for acid thickening

    SciTech Connect

    Dixon, K.W.

    1980-09-30

    Acids, thickened with branched emulsion or suspension polymers of diallyldimethylammonium chloride are useful as oil well drilling and fracturing fluids for stimulating well production and in other applications, such as thickeners for cosmetics, paints, adhesives, textiles and printing inks.

  16. Acid-base chemistry

    SciTech Connect

    Hand, C.W.; Blewit, H.L.

    1985-01-01

    The book is not a research compendium and there are no references to the literature. It is a teaching text covering the entire range of undergraduate subject matter dealing with acid-base chemistry (some of it remotely) as taught in inorganic, analytical, and organic chemistry courses. The excellent chapters VII through IX deal in detail with the quantitative aspects of aqueous acid-base equilibria (salt hydrolysis and buffer, titrations, polyprotic and amphoteric substances).

  17. Utilization of acid tars

    SciTech Connect

    Frolov, A.F.; Denisova, T.L.; Aminov, A.N.

    1987-01-01

    Freshly produced acid tar (FPAT), obtained as refinery waste in treating petroleum oils with sulfuric acid and oleum, contains 80% or more sulfuric acid. Of such tars, pond acid tars, which contain up to 80% neutral petroleum products and sulfonated resins, are more stable, and have found applications in the production of binders for paving materials. In this article the authors are presenting results obtained in a study of the composition and reactivity of FPAT and its stability in storage in blends with asphalts obtained in deasphalting operations, and the possibility of using the FPAT in road construction has been examined. In this work, wastes were used which were obtained in treating the oils T-750, KhF-12, I-8A, and MS-14. Data on the change in group chemical composition of FPAT are shown, and the acidity, viscosity, needle penetration, and softening point of acid tars obtained from different grades of oils are plotted as functions of the storage time. It is also shown that the fresh and hardened FPATs differ in their solubilities in various solvents.

  18. Mammalian Fatty Acid Elongases

    PubMed Central

    Jump, Donald B.

    2009-01-01

    Summary Very long chain fatty acids confer functional diversity on cells by variations in their chain length and degree of unsaturation. Microsomal fatty acid elongation represents the major pathway for determining the chain length of saturated, monounsaturated, and polyunsaturated fatty acids in cellular lipids. The overall reaction for fatty acid elongation involves four enzymes and utilizes malonyl CoA, NADPH, and fatty acyl CoA as substrates. While the fundamental pathway and its requirements have been known for many years, recent advances have revealed a family of enzymes involved in the first step of the reaction, i.e., the condensation reaction. Seven fatty acid elongase subtypes (Elovl #1–7) have been identified in the mouse, rat, and human genomes. These enzymes determine the rate of overall fatty acid elongation. Moreover, these enzymes also display differential substrate specificity, tissue distribution, and regulation, making them important regulators of cellular lipid composition as well as specific cellular functions. Herein, methods are described to measure elongase activity, analyze elongation products, and alter cellular elongase expression. PMID:19763486

  19. Neutron Nucleic Acid Crystallography.

    PubMed

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination. PMID:26227050

  20. Autophagy on acid.

    PubMed

    Wojtkowiak, Jonathan W; Gillies, Robert J

    2012-11-01

    The microenvironment of solid tumors tends to be more acidic (6.5-7.0) than surrounding normal (7.2-7.4) tissue. Chaotic vasculature, oxygen limitation and major metabolic changes all contribute to the acidic microenvironment. We have previously proposed that low extracellular pH (pHe) plays a critical role in the development and progression of solid tumors. While extracellular acidosis is toxic to most normal cells, cancer cells can adapt and survive under this harsh condition. In this study, we focused on identifying survival strategies employed by cancer cells when challenged with an acidic pHe (6.6-6.7) either acutely or for many generations. While acutely acidic cells did not grow, those acclimated over many generations grew at the same rate as control cells. We observed that these cells induce autophagy in response to acidosis both acutely and chronically, and that this adaptation appears to be necessary for survival. Inhibition of autophagy in low pH cultured cells results in cell death. Histological analysis of tumor xenografts reveals a strong correlation of LC3 protein expression in regions projected to be acidic. Furthermore, in vivo buffering experiments using sodium bicarbonate, previously shown to raise extracellular tumor pH, decreases LC3 protein expression in tumor xenografts. These data imply that autophagy can be induced by extracellular acidosis and appears to be chronically employed as a survival adaptation to acidic microenvironments. PMID:22874557

  1. Method for isolating nucleic acids

    DOEpatents

    Hurt, Jr., Richard Ashley; Elias, Dwayne A.

    2015-09-29

    The current disclosure provides methods and kits for isolating nucleic acid from an environmental sample. The current methods and compositions further provide methods for isolating nucleic acids by reducing adsorption of nucleic acids by charged ions and particles within an environmental sample. The methods of the current disclosure provide methods for isolating nucleic acids by releasing adsorbed nucleic acids from charged particles during the nucleic acid isolation process. The current disclosure facilitates the isolation of nucleic acids of sufficient quality and quantity to enable one of ordinary skill in the art to utilize or analyze the isolated nucleic acids for a wide variety of applications including, sequencing or species population analysis.

  2. Acidification and Acid Rain

    NASA Astrophysics Data System (ADS)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw tremendous progress in the documentation of the chemistry of the atmosphere, precipitation, and the systems impacted by acid atmospheric deposition. Chronic acidification of ecosystems results in chemical changes to soil and to surface waters and groundwater as a result of reduction of base cation supply or an increase in acid (H+) supply, or both. The most fundamental changes during chronic acidification are an increase in exchangeable H+ or Al3+ (aluminum) in soils, an increase in H+ activity (˜concentration) in water in contact with soil, and a decrease in alkalinity in waters draining watersheds. Water draining from the soil is acidified and has a lower pH (=-log [H+]). As systems acidify, their biotic community changes.Acidic surface waters occur in many parts of the world as a consequence of natural processes and also due to atmospheric deposition of strong acid (e.g., Canada, Jeffries et al. (1986); the United Kingdom, Evans and Monteith (2001); Sweden, Swedish Environmental Protection Board (1986); Finland, Forsius et al. (1990); Norway, Henriksen et al. (1988a); and the United States (USA), Brakke et al. (1988)). Concern over acidification in the temperate regions of the northern hemisphere has been driven by the potential for accelerating natural acidification by pollution of the atmosphere with acidic or acidifying compounds. Atmospheric pollution ( Figure 1) has resulted in an increased flux of acid to and through ecosystems. Depending on the ability of an ecosystem to neutralize the increased flux of acidity, acidification may increase only imperceptibly or be accelerated at a rate that

  3. Discovery of essential fatty acids

    PubMed Central

    Spector, Arthur A.; Kim, Hee-Yong

    2015-01-01

    Dietary fat was recognized as a good source of energy and fat-soluble vitamins by the first part of the 20th century, but fatty acids were not considered to be essential nutrients because they could be synthesized from dietary carbohydrate. This well-established view was challenged in 1929 by George and Mildred Burr who reported that dietary fatty acid was required to prevent a deficiency disease that occurred in rats fed a fat-free diet. They concluded that fatty acids were essential nutrients and showed that linoleic acid prevented the disease and is an essential fatty acid. The Burrs surmised that other unsaturated fatty acids were essential and subsequently demonstrated that linolenic acid, the omega-3 fatty acid analog of linoleic acid, is also an essential fatty acid. The discovery of essential fatty acids was a paradigm-changing finding, and it is now considered to be one of the landmark discoveries in lipid research. PMID:25339684

  4. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  5. Nitric acid-formic acid compatibility in DWPF

    SciTech Connect

    Eibling, R.E.

    1992-10-20

    The addition of the Nitric Acid Flowsheet to the DWPF feed preparation process introduces nitric acid into a vessel which will subsequently receive a formic acid solution. The combination of these two acids suggests that a denitration reaction might occur. This memorandum reviews the conditions under which a denitration reaction is possible and compares these conditions to DWPF operating conditions.

  6. ADVANCED OXIDATION PROCESS

    SciTech Connect

    Dr. Colin P. Horwitz; Dr. Terrence J. Collins

    2003-11-04

    The removal of recalcitrant sulfur species, dibenzothiophene and its derivatives, from automotive fuels is an integral component in the development of cleaner burning and more efficient automobile engines. Oxidative desulfurization (ODS) wherein the dibenzothiophene derivative is converted to its corresponding sulfoxide and sulfone is an attractive approach to sulfur removal because the oxidized species are easily extracted or precipitated and filtered from the hydrocarbon phase. Fe-TAML{reg_sign} activators of hydrogen peroxide (TAML is Tetra-Amido-Macrocyclic-Ligand) catalytically convert dibenzothiophene and its derivatives rapidly and effectively at moderate temperatures (50-60 C) and ambient pressure to the corresponding sulfoxides and sulfones. The oxidation process can be performed in both aqueous systems containing alcohols such as methanol, ethanol, or t-butanol, and in a two-phase hydrocarbon/aqueous system containing tert-butanol or acetonitrile. In the biphasic system, essentially complete conversion of the DBT to its oxidized products can be achieved using slightly longer reaction times than in homogeneous solution. Among the key features of the technology are the mild reaction conditions, the very high selectivity where no over oxidation of the sulfur compounds occurs, the near stoichiometric use of hydrogen peroxide, the apparent lack of degradation of sensitive fuel components, and the ease of separation of oxidized products.

  7. Amino-acid contamination of aqueous hydrochloric acid.

    NASA Technical Reports Server (NTRS)

    Wolman, Y.; Miller, S. L.

    1971-01-01

    Considerable amino-acid contamination in commercially available analytical grade hydrochloric acid (37% HCl) was found. One bottle contained 8,300 nmol of amino-acids per liter. A bottle from another supplier contained 6,700 nmol per liter. The contaminants were mostly protein amino-acids and several unknowns. Data on the volatility of the amino-acids during HCl distillation were also obtained.

  8. ADVANCED OXIDATION PROCESS

    SciTech Connect

    Colin P. Horwitz; Terrence J. Collins

    2003-10-22

    The design of new, high efficiency and cleaner burning engines is strongly coupled with the removal of recalcitrant sulfur species, dibenzothiophene and its derivatives, from fuels. Oxidative desulfurization (ODS) wherein these dibenzothiophene derivatives are oxidized to their corresponding sulfoxides and sulfones is an approach that has gained significant attention. Fe-TAML{reg_sign} activators of hydrogen peroxide (TAML is Tetra-Amido-Macrocyclic-Ligand) convert in a catalytic process dibenzothiophene and its derivatives to the corresponding sulfoxides and sulfones rapidly at moderate temperatures (60 C) and ambient pressure. The reaction can be performed in both an aqueous system containing an alcohol (methanol, ethanol, or t-butanol) to solubilize the DBT and in a two-phase hydrocarbon/aqueous system where the alcohol is present in both phases and facilitates the oxidation. Under a consistent set of conditions using the FeBF{sub 2} TAML activator, the degree of conversion was found to be t-butanol > methanol > ethanol. In the cases of methanol and ethanol, both the sulfoxide and sulfone were observed while for t-butanol only the sulfone was detected. In the two-phase system, the alcohol may function as an inverse phase transfer agent. The oxidation was carried out using two different TAML activators. In homogeneous solution, approximately 90% oxidation of the DBT could be achieved using the prototype TAML activator, FeB*, by sonicating the solution at near room temperature. In bi-phasic systems conversions as high as 50% were achieved using the FeB* TAML activator and hydrogen peroxide at 100 C. The sonication method yielded only {approx}6% conversion but this may have been due to mixing.

  9. Novel bimetallic dispersed catalysts for temperature-programmed coal liquefaction. Technical progress report, October 1995--December 1995

    SciTech Connect

    Song, C.; Cooke, W.S.; Schmidt, E.; Schobert, H.H.

    1996-02-01

    Coal liquefaction involves cleavage of methylene, dimethylene and ether bridges connecting polycyclic aromatic units and the reactions of various oxygen functional groups. Here in this quarterly, we report on the catalytic effects of several molybdenum-, cobalt-, and iron-containing compounds in the reactions of dibenzothiophene (DBT) with hydrogen under conditions related to coal liquefaction. The catalytic effects of several molybdenum-, cobalt-, and iron-containing compounds have been examined in the hydrogenation and hydrodesulfurization reactions of dibenzothiophene (DBT) under conditions related to coal liquefaction. The metal compounds are candidate catalyst precursors for direct coal liquefaction. The reactions were carried out in batch microautoclave reactors at 400{degrees}C for 30 minutes with 6.9 MPa (cold) hydrogen pressure, and tridecane solvent. A metal loading of 0.5 mol% resulted in low conversion and only hydrogenation. Addition of sulfur in 4:1 molar ratio led only to a minor increase in conversion and hydrodesulfurization. The use of a higher boiling solvent (octadecane vs. tridecane) was beneficial in providing increased conversion, hydrodesulfurization, and hydrogenation. An increase in metal compound loading to 36.2 mol% led to a dramatic increase in conversion, hydrodesulfurization, and hydrocracking. Molybdenum hexacarbonyl at 36 mol% loading, with added sulfur at 6:1 ratio and octadecane solvent, gave 100% conversion of dibenzothiophene to other products with 100% hydrodesulfurization. Ammonium tetrathiomolybdate and molybdenum(III) chloride are less active under similar conditions. A cobalt-molybdenum thiocubane complex gave unexpectedly low conversions. Iron and cobalt carbonyls also provided very low conversions, even with added sulfur.

  10. Optical high acidity sensor

    DOEpatents

    Jorgensen, B.S.; Nekimken, H.L.; Carey, W.P.; O`Rourke, P.E.

    1997-07-22

    An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber. 10 figs.

  11. Domoic Acid Epileptic Disease

    PubMed Central

    Ramsdell, John S.; Gulland, Frances M.

    2014-01-01

    Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis. PMID:24663110

  12. Domoic acid epileptic disease.

    PubMed

    Ramsdell, John S; Gulland, Frances M

    2014-03-01

    Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis. PMID:24663110

  13. Optical high acidity sensor

    DOEpatents

    Jorgensen, Betty S.; Nekimken, Howard L.; Carey, W. Patrick; O'Rourke, Patrick E.

    1997-01-01

    An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and, a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber.

  14. A Demonstration of Acid Rain

    ERIC Educational Resources Information Center

    Fong, Man Wai

    2004-01-01

    A demonstration showing acid rain formation is described. Oxides of sulfur and nitrogen that result from the burning of fossil fuels are the major pollutants of acid rain. In this demonstration, SO[subscript 2] gas is produced by the burning of matches. An acid-base indicator will show that the dissolved gas turns an aqueous solution acidic.

  15. Partial oxidation of n-tetradecane over 1 wt % Pt/y-AlO3 and Co0.4Mo0.6Cx

    SciTech Connect

    Haynes, D.; Berry, D.; Shekhawat, D.; Xiao, T.; Green, M.; Spivey, J.

    2008-01-01

    Catalytic partial oxidation (CPOX) of liquid fuels is being widely studied as an option for producing a hydrogenrich gas stream for fuel cells. However, deactivation of catalysts by carbon deposition and sulfur poisoning in this process is a key technical challenge. Here, the deactivation of Co0.4Mo0.6Cx has been compared to that of 1 wt % Pt/γ-Al2O3 in a fixed-bed catalytic reactor, using mixtures of n-tetradecane and either 1-methylnaphthalene (1-MN) or dibenzothiophene (DBT) to simulate diesel fuel. The results show that Co0.4Mo0.6Cx is stable and active for the CPOX of n-tetradecane at 850 °C, 50000 scc/(gcat h), and an O/C ratio of 1.2. This catalyst produces slightly lower H2 and CO yields than Pt/γ-Al2O3, but still close to equilibrium values for 5 h. A low concentration of sulfur (50 ppmw as DBT) has little effect on either activity or selectivity for the carbide or Pt/γ-Al2O3 catalyst. However, the presence of 1-MN or a high sulfur concentration (1000 ppmw as DBT) deactivates both catalysts, resulting in reaction products that are typical of gas-phase reactions in a blank reactor. The addition of 1-MN or 1000 ppmw DBT to n-tetradecane produces qualitatively similar results on both catalysts: H2 production decreases continuously in the presence of either 1-MN or DBT, and CO drops to a stationary level. This drop in synthesis gas yields corresponds to an increase in steam, CO2, and olefin yields, suggesting that the contaminants deactivate sites that are active for steam and dry reforming reactions downstream of the reactor inlet, where rapid oxidation takes place. Once the contaminants are removed, initial activity returns more quickly for the carbide than for Pt/γ-Al2O3.

  16. Photocatalytic degradation of oil industry hydrocarbons models at laboratory and at pilot-plant scale

    SciTech Connect

    Vargas, Ronald; Nunez, Oswaldo

    2010-02-15

    Photodegradation/mineralization (TiO{sub 2}/UV Light) of the hydrocarbons: p-nitrophenol (PNP), naphthalene (NP) and dibenzothiophene (DBT) at three different reactors: batch bench reactor (BBR), tubular bench reactor (TBR) and tubular pilot-plant (TPP) were kinetically monitored at pH = 3, 6 and 10, and the results compared using normalized UV light exposition times. The results fit the Langmuir-Hinshelwood (LH) model; therefore, LH adsorption equilibrium constants (K) and apparent rate constants (k) are reported as well as the apparent pseudo-first-order rate constants, k{sub obs}{sup '} = kK/(1 + Kc{sub r}). The batch bench reactor is the most selective reactor toward compound and pH changes in which the reactivity order is: NP > DBT > PNP, however, the catalyst adsorption (K) order is: DBT > NP > PNP at the three pH used but NP has the highest k values. The tubular pilot-plant (TPP) is the most efficient of the three reactors tested. Compound and pH photodegradation/mineralization selectivity is partially lost at the pilot plant where DBT and NP reaches ca. 90% mineralization at the pH used, meanwhile, PNP reaches only 40%. The real time, in which these mineralization occur are: 180 min for PNP and 60 min for NP and DBT. The mineralization results at the TPP indicate that for the three compounds, the rate limiting step is the same as the degradation one. So that, there is not any stable intermediate that may accumulate during the photocatalytic treatment. (author)

  17. Oleanolic acid ethanol monosolvate

    PubMed Central

    Froelich, Anna; Gzella, Andrzej K.

    2010-01-01

    Crystals of the title compound (systematic name: 3β-hy­droxy­olean-12-en-28-oic acid ethanol monosolvate), C30H48O3·C2H5OH, were obtained from unsuccessful co-crystallization trials. The asymmetric unit contains two symmetry-independent oleanolic acid mol­ecules, as well as two ethanol solvent mol­ecules. Inter­molecular O—H⋯O hydrogen bonds stabilize the crystal packing. In the oleanolic acid mol­ecules, ring C has a slightly distorted envelope conformation, while rings A, B, D and E adopt chair conformations and rings D and E are cis-fused. Both independent ethanol mol­ecules are orientationally disordered [occupancy ratios of 0.742 (8):0.258 (8) and 0.632 (12):0.368 (12). PMID:21588987

  18. Amino acid analysis.

    PubMed

    Crabb, J W; West, K A; Dodson, W S; Hulmes, J D

    2001-05-01

    Amino acid analysis (AAA) is one of the best methods to quantify peptides and proteins. Two general approaches to quantitative AAA exist, namely, classical postcolumn derivatization following ion-exchange chromatography and precolumn derivatization followed by reversed-phase HPLC (RP-HPLC). Excellent instrumentation and several specific methodologies are available for both approaches, and both have advantages and disadvantages. This unit focuses on picomole-level AAA of peptides and proteins using the most popular precolumn-derivatization method, namely, phenylthiocarbamyl amino acid analysis (PTC-AAA). It is directed primarily toward those interested in establishing the technology with a modest budget. PTC derivatization and analysis conditions are described, and support and alternate protocols describe additional techniques necessary or useful for most any AAA method--e.g., sample preparation, hydrolysis, instrument calibration, data interpretation, and analysis of difficult or unusual residues such as cysteine, tryptophan, phosphoamino acids, and hydroxyproline. PMID:18429107

  19. Acid rain: Controllable?

    NASA Astrophysics Data System (ADS)

    Machta, Lester

    Acid rain is one of a growing number of environmental issues in which impacts are far removed from the source o f the irritants. Those who suffer may differ in geographical area from those who benefit from the activity which releases pollution to the atmosphere. Like the issue concerning the depletion of ozone by manufactured chemicals, the acid rain issue further emphasizes the need for continuing atmospheric chemistry research, a science whose history dates back but a few decades. Examination of the acid rain issue also calls for intimate collaboration of atmospheric scientists with ecologists, biologists, and other scientists, who must advise the geophysicists regarding what chemicals in the environment produce damage, their mode of entry into an ecosystem, and the need to understand acute or chronic impacts.

  20. Acid rain in Asia

    NASA Astrophysics Data System (ADS)

    Bhatti, Neeloo; Streets, David G.; Foell, Wesley K.

    1992-07-01

    Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world.

  1. NITRIC ACID PICKLING PROCESS

    DOEpatents

    Boller, E.R.; Eubank, L.D.

    1958-08-19

    An improved process is described for the treatment of metallic uranium surfaces preparatory to being given hot dip coatings. The process consists in first pickling the uraniunn surInce with aqueous 50% to 70% nitric acid, at 60 to 70 deg C, for about 5 minutes, rinsing the acid solution from the uranium article, promptly drying and then passing it through a molten alkali-metal halide flux consisting of 42% LiCl, 53% KCla and 5% NaCl into a molten metal bath consisting of 85 parts by weight of zinc and 15 parts by weight of aluminum

  2. [Nicotinic acid and nicotinamide].

    PubMed

    Kobayashi, M; Shimizu, S

    1999-10-01

    Nicotinic acid and nicotinamide are called niacin. They are the antipellagra vitamin essential to many animals for growth and health. In human being, niacin is believed necessary together with other vitamins for the prevention and cure of pellagra. Niacin is widely distributed in nature; appreciable amounts are found in liver, fish, yeast and cereal grains. Nicotinamide is a precursor of the coenzyme NAD and NADP. Some of the most understood metabolic processes that involve niacin are glycolysis, fatty acid synthesis and respiration. Niacin is also related to the following diseases: Hartnup disease; blue diaper syndrome; tryptophanuria; hydroxykynureninuria; xanthurenic aciduria; Huntington's disease. PMID:10540864

  3. Fatty Acids of Thiobacillus thiooxidans

    PubMed Central

    Levin, Richard A.

    1971-01-01

    Fatty acid spectra were made on Thiobacillus thiooxidans cultures both in the presence and absence of organic compounds. Small additions of glucose or acetate had no significant effect either on growth or fatty acid content. The addition of biotin had no stimulatory effect but did result in slight quantitative changes in the fatty acid spectrum. The predominant fatty acid was a C19 cyclopropane acid. PMID:4945206

  4. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  5. Comparison of Buffer Effect of Different Acids During Sandstone Acidizing

    NASA Astrophysics Data System (ADS)

    Umer Shafiq, Mian; Khaled Ben Mahmud, Hisham; Hamid, Mohamed Ali

    2015-04-01

    The most important concern of sandstone matrix acidizing is to increase the formation permeability by removing the silica particles. To accomplish this, the mud acid (HF: HCl) has been utilized successfully for many years to stimulate the sandstone formations, but still it has many complexities. This paper presents the results of laboratory investigations of different acid combinations (HF: HCl, HF: H3PO4 and HF: HCOOH). Hydrofluoric acid and fluoboric acid are used to dissolve clays and feldspar. Phosphoric and formic acids are added as a buffer to maintain the pH of the solution; also it allows the maximum penetration of acid into the core sample. Different tests have been performed on the core samples before and after the acidizing to do the comparative study on the buffer effect of these acids. The analysis consists of permeability, porosity, color change and pH value tests. There is more increase in permeability and porosity while less change in pH when phosphoric and formic acids were used compared to mud acid. From these results it has been found that the buffer effect of phosphoric acid and formic acid is better than hydrochloric acid.

  6. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  7. Docosahexaenoic acid and lactation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Docosahexaenoic acid (DHA) is an important component of membrane phospholipids in the retina, and brain, and accumulates rapidly in these tissues during early infancy. DHA is present in human milk, but the amount varies considerably and is largely dependent on maternal diet. This article reviews dat...

  8. ACID AEROSOL MEASUREMENT WORKSHOP

    EPA Science Inventory

    This report documents the discussion and results of the U.S. EPA Acid Aerosol Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...

  9. Acid Rain Classroom Projects.

    ERIC Educational Resources Information Center

    Demchik, Michael J.

    2000-01-01

    Describes a curriculum plan in which students learn about acid rain through instructional media, research and class presentations, lab activities, simulations, design, and design implementation. Describes the simulation activity in detail and includes materials, procedures, instructions, examples, results, and discussion sections. (SAH)

  10. Acid rain bibliography

    SciTech Connect

    Sayers, C.S.

    1983-09-01

    This bibliography identifies 900 citations on various aspects of Acid Rain, covering published bibliographies, books, reports, conference and symposium proceedings, audio visual materials, pamphlets and newsletters. It includes five sections: citations index (complete record of author, title, source, order number); KWIC index; title index; author index; and source index. 900 references.

  11. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Oates-Bockenstedt, Catherine

    1997-01-01

    Details an activity designed to motivate students by incorporating science-related issues into a classroom debate. Includes "The Acid Rain Bill" and "Position Guides" for student roles as committee members, consumers, governors, industry owners, tourism professionals, senators, and debate directors. (DKM)

  12. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Bybee, Rodger; And Others

    1984-01-01

    Describes an activity which provides opportunities for role-playing as industrialists, ecologists, and government officials. The activity involves forming an international commission on acid rain, taking testimony, and, based on the testimony, making recommendations to governments on specific ways to solve the problem. Includes suggestions for…

  13. The Acid Rain Game.

    ERIC Educational Resources Information Center

    Rakow, Steven J.; Glenn, Allen

    1982-01-01

    Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.…

  14. Acid Rain Investigations.

    ERIC Educational Resources Information Center

    Hugo, John C.

    1992-01-01

    Presents an activity in which students investigate the formation of solid ammonium chloride aerosol particles to help students better understand the concept of acid rain. Provides activity objectives, procedures, sample data, clean-up instructions, and questions and answers to help interpret the data. (MDH)

  15. Brain amino acid sensing.

    PubMed

    Tsurugizawa, T; Uneyama, H; Torii, K

    2014-09-01

    The 20 different amino acids, in blood as well as in the brain, are strictly maintained at the same levels throughout the day, regardless of food intake. Gastric vagal afferents only respond to free glutamate and sugars, providing recognition of food intake and initiating digestion. Metabolic control of amino acid homeostasis and diet-induced thermogenesis is triggered by this glutamate signalling in the stomach through the gut-brain axis. Rats chronically fed high-sugar and high-fat diets do not develop obesity when a 1% (w/v) monosodium glutamate (MSG) solution is available in a choice paradigm. Deficiency of the essential amino acid lysine (Lys) induced a plasticity in rats in response to Lys. This result shows how the body is able to identify deficient nutrients to maintain homeostasis. This plastic effect is induced by activin A activity in the brain, particularly in certain neurons in the lateral hypothalamic area (LHA) which is the centre for amino acid homeostasis and appetite. These neurons respond to glutamate signalling in the oral cavity by which umami taste is perceived. They play a quantitative role in regulating ingestion of deficient nutrients, thereby leading to a healthier life. After recovery from malnutrition, rats prefer MSG solutions, which serve as biomarkers for protein nutrition. PMID:25200295

  16. Targeting tumor acidity

    NASA Astrophysics Data System (ADS)

    Reshetnyak, Yana K.; Engelman, Donald M.; Andreev, Oleg A.

    2012-02-01

    One of the main features of solid tumors is extracellular acidity, which correlates with tumor aggressiveness and metastatic potential. We introduced novel approach in targeting of acidic tumors, and translocation of cell-impermeable cargo molecules across cellular membrane. Our approach is based on main principle of insertion and folding of a polypeptide in lipid bilayer of membrane. We have identified family of pH Low Insertion Peptides (pHLIPs), which are capable spontaneous insertion and folding in membrane at mild acidic conditions. The affinity of peptides of pHLIP family to membrane at low pH is several times higher than at neutral pH. The process of peptides folding occurs within milliseconds. The energy released in a result of folding (about 2 kcal/mol) could be used to move polar cargo across a membrane, which is a novel concept in drug delivery. pHLIP peptides could be considered as a pH-sensitive single peptide molecular transporters and conjugated with imaging probes for fluorescence, MR, PET and SPECT imaging, they represent a novel in vivo marker of acidity. The work is supported by NIH grants CA133890 and GM073857 to OAA, DME, YRK.

  17. Synthesis of (+)-Coronafacic Acid

    PubMed Central

    Taber, Douglass F.; Sheth, Ritesh B.; Tian, Weiwei

    2009-01-01

    An enantioselective synthesis of (+)-coronafacic acid has been achieved. Rhodium catalyzed cyclization of an α-diazoester provided the intermediate cyclopentanone in high enantiomeric purity. Subsequent Fe-mediated cyclocarbonylation of a derived alkenyl cyclopropane gave a bicyclic enone, that then was hydrogenated and carried on to the natural product. PMID:19231870

  18. Plant fatty acid hydroxylase

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    2000-01-01

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds.

  19. Spermatotoxicity of dichloroacetic acid

    EPA Science Inventory

    The testicular toxicity of dichloroacetic acid (DCA), a disinfection byproduct of drinking water, was evaluated in adult male rats given both single and multiple (up to 14 d) oral doses. Delayed spermiation and altered resorption of residual bodies were observed in rats given sin...

  20. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    SciTech Connect

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  1. Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters

    DOEpatents

    Moens, Luc

    2003-06-24

    A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a solvent selected from the group consisting of water, ethyl acetate, chloroform, acetone, ethanol, tetrahydrofuran and acetonitrile, to form a quaternary ammonium salt of the lower alkyl 5-bromolevulinate; and b) hydrolyzing the quaternary ammonium salt with an inorganic acid to form an acid addition salt of delta-aminolevulinic acid.

  2. Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations.

    PubMed

    Ahmad, I; Ali Sheraz, M; Ahmed, S; Shad, Z; Vaid, F H M

    2012-06-01

    This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH(2) ) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34-0.95 × 10(-3) min(-1) in light, 0.38-1.24 × 10(-2) day(-1) in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26-1.45 × 10(-2) M(-1) min(-1) in light, 3.75-8.50 × 10(-3) M(-1) day(-1) in dark) for the interaction of AH(2) and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH(2) both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH(2) in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH(2) -excited triplet state by CT and TA and by the inhibition of AH(2) degradation through complex formation with BA. AH(2) leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations. PMID:22296174

  3. Fatty acid-producing hosts

    SciTech Connect

    Pfleger, Brian F; Lennen, Rebecca M

    2013-12-31

    Described are hosts for overproducing a fatty acid product such as a fatty acid. The hosts include an exogenous nucleic acid encoding a thioesterase and, optionally, an exogenous nucleic acid encoding an acetyl-CoA carboxylase, wherein an acyl-CoA synthetase in the hosts are functionally delected. The hosts prefereably include the nucleic acid encoding the thioesterase at an intermediate copy number. The hosts are preferably recominantly stable and growth-competent at 37.degree. C. Methods of producing a fatty acid product comprising culturing such hosts at 37.degree. C. are also described.

  4. [Lipid synthesis by an acidic acid tolerant Rhodotorula glutinis].

    PubMed

    Lin, Zhangnan; Liu, Hongjuan; Zhang, Jian'an; Wang, Gehua

    2016-03-01

    Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis. PMID:27349116

  5. Circulating folic acid in plasma: relation to folic acid fortification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The implementation of folic acid fortification in the United States has resulted in unprecedented amounts of this synthetic form of folate in the American diet. Folic acid in circulation may be a useful measure of physiologic exposure to synthetic folic acid, and there is a potential for elevated co...

  6. College Chemistry Students' Mental Models of Acids and Acid Strength

    ERIC Educational Resources Information Center

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  7. NAPAP (National Acid Precipitation Assessment Program) results on acid rain

    SciTech Connect

    Not Available

    1990-06-01

    The National Acid Precipitation Assessment Program (NAPAP) was mandated by Congress in 1980 to study the effects of acid rain. The results of 10 years of research on the effect of acid deposition and ozone on forests, particularly high elevation spruce and fir, southern pines, eastern hardwoods and western conifers, will be published this year.

  8. Acid Earth--The Global Threat of Acid Pollution.

    ERIC Educational Resources Information Center

    McCormick, John

    Acid pollution is a major international problem, but the debate it has elicited has often clouded the distinction between myth and facts. This publication attempts to concerning the acid pollution situation. This publication attempts to identify available facts. It is the first global review of the problem of acid pollution and the first to…

  9. Industrial ecotoxicology "acid rain".

    PubMed

    Astolfi, E; Gotelli, C; Higa, J

    1986-01-01

    The acid rain phenomenon was studied in the province of Cordoba, Argentina. This study, based on a previously outlined framework, determined the anthropogenic origin of the low pH due to the presence of industrial hydrochloric acid wastage. This industrial ecotoxicological phenomenon seriously affected the forest wealth, causing a great defoliation of trees and shrubs, with a lower effect on crops. A survey on its effects on human beings has not been carried out, but considering the corrosion caused to different metals and its denouncing biocide effect on plants and animals, we should expect to find some kind of harm to the health of the workers involved or others engaged in farming, and even to those who are far away from the polluting agent. PMID:3758667

  10. [Progress in glucaric acid].

    PubMed

    Qiu, Yuying; Fang, Fang; Du, Guocheng; Chen, Jian

    2015-04-01

    Glucaric acid (GA) is derived from glucose and commonly used in chemical industry. It is also considered as one of the "Top value-added chemicals from biomass" as carbohydrate monomers to produce various synthetic polymers and bioenergy. The demand for GA in food manufacture is increasing. GA has also attracted public attentions due to its therapeutic uses such as regulating hormones, increasing the immune function and reducing the risks of cancers. Currently GA is produced by chemical oxidation. Research on production of GA via microbial synthesis is still at preliminary stage. We reviewed the advances of glucaric acid applications, preparation and quantification methods. The prospects on production of GA by microbial fermentation were also discussed. PMID:26380405

  11. Acid hydrolysis of cellulose

    SciTech Connect

    Salazar, H.

    1980-12-01

    One of the alternatives to increase world production of etha nol is by the hydrolysis of cellulose content of agricultural residues. Studies have been made on the types of hydrolysis: enzimatic and acid. Data obtained from the sulphuric acid hydrolysis of cellulose showed that this process proceed in two steps, with a yield of approximately 95% glucose. Because of increases in cost of alternatives resources, the high demand of the product and the more economic production of ethanol from cellulose materials, it is certain that this technology will be implemented in the future. At the same time further studies on the disposal and reuse of the by-products of this production must be undertaken.

  12. Eucomic acid methanol monosolvate

    PubMed Central

    Li, Guo-Qiang; Li, Yao-Lan; Wang, Guo-Cai; Liang, Zhi-Hong; Jiang, Ren-Wang

    2011-01-01

    In the crystal structure of the title compound [systematic name: 2-hy­droxy-2-(4-hy­droxy­benz­yl)butane­dioic acid methanol monosolvate], C11H12O6·CH3OH, the dihedral angles between the planes of the carboxyl groups and the benzene ring are 51.23 (9) and 87.97 (9)°. Inter­molecular O—H⋯O hydrogen-bonding inter­actions involving the hy­droxy and carb­oxy­lic acid groups and the methanol solvent mol­ecule give a three-dimensional structure. PMID:22091200

  13. (Radioiodinated free fatty acids)

    SciTech Connect

    Knapp, Jr., F. F.

    1987-12-11

    The traveler participated in the Second International Workshop on Radioiodinated Free Fatty Acids in Amsterdam, The Netherlands where he presented an invited paper describing the pioneering work at the Oak Ridge National Laboratory (ORNL) involving the design, development and testing of new radioiodinated methyl-branched fatty acids for evaluation of heart disease. He also chaired a technical session on the testing of new agents in various in vitro and in vivo systems. He also visited the Institute for Clinical and Experimental Nuclear Medicine in Bonn, West Germany, to review, discuss, plan and coordinate collaborative investigations with that institution. In addition, he visited the Cyclotron Research Center in Liege, Belgium, to discuss continuing collaborative studies with the Osmium-191/Iridium-191m radionuclide generator system, and to complete manuscripts and plan future studies.

  14. Tunnelling in carbonic acid.

    PubMed

    Wagner, J Philipp; Reisenauer, Hans Peter; Hirvonen, Viivi; Wu, Chia-Hua; Tyberg, Joseph L; Allen, Wesley D; Schreiner, Peter R

    2016-06-14

    The cis,trans-conformer of carbonic acid (H2CO3), generated by near-infrared radiation, undergoes an unreported quantum mechanical tunnelling rotamerization with half-lives in cryogenic matrices of 4-20 h, depending on temperature and host material. First-principles quantum chemistry at high levels of theory gives a tunnelling half-life of about 1 h, quite near those measured for the fastest rotamerizations. PMID:27248671

  15. Optimize acid gas removal

    SciTech Connect

    Nicholas, D.M.; Wilkins, J.T.

    1983-09-01

    Innovative design of physical solvent plants for acid gas removal can materially reduce both installation and operating costs. A review of the design considerations for one physical solvent process (Selexol) points to numerous arrangements for potential improvement. These are evaluated for a specific case in four combinations that identify an optimum for the case in question but, more importantly, illustrate the mechanism for use for such optimization elsewhere.

  16. Studies on terreic acid.

    PubMed

    Yamamoto, H; Moriyama, K; Jinnouchi, H; Yagishita, K

    1980-03-01

    It was found that Aspergillus sp. No. Y-8980 which was isolated from a soil sample collected at Yoron Island in Kagoshima Prefecture belonged to Aspergillus terreus group by morphological observation. The active substance produced by the strain was obtained with a high yield in sucrose-yeast extract medium and extracted by chloroform, ethyl acetate and n-butanol at pH 2.4 approximately 2.6 from the culture broth. The substance was crystallized from chloroform and ethyl acetate after charcoal treatment of the crude crystal. From various physico-chemical properties, it was found that the substance was identical to terreic acid. Terreic acid showed MICs of 25 approximately 100 mcg/ml, 12.5 mcg/ml and 50 mcg/ml against Gram-positive and Gram-negative bacteria, Xanthomonas oryzae and Xanthomonas citri, respectively, but it did not control Pseudomonas, fungi and yeast. The LD50 was 75 mg/kg i.p. and i.v. in mice. With regards to the anti-tumor effect, the morphological degeneration on HeLa cells (human carcinoma cells) was observed in the concentrations of more than 6.25 mcg/ml of terreic acid. An increase of body weight of mice caused by Ehrlich ascites carcinoma cells was not definitely observed by the daily administration of 150 mcg of terreic acid per mouse for 8 consecutive days. Above showed the enough survival effect in dd mice implanted with Ehrlich ascites carcinoma cells, and the effect also was demonstrated by anatomies of mice. PMID:7190624

  17. Perfluorooctanoic acid and environmental risks

    EPA Science Inventory

    Perfluorooctanoic acid (PFOA) is a member of the perfluoroalkyl acids (PFAA) family of chemicals, which consist of a carbon backbone typically four to fourteen carbons in length and a charged functional moiety.

  18. Folic Acid Questions and Answers

    MedlinePlus

    ... swallow large pills. How can I take a vitamin with folic acid? A : These days, multivitamins with folic acid come in chewable chocolate or fruit flavors, liquids, and large oval or smaller round ...

  19. Pantothenic acid (Vitamin B5)

    MedlinePlus

    Pantothenic acid is a vitamin, also known as vitamin B5. It is widely found in both plants and animals ... Vitamin B5 is commercially available as D-pantothenic acid, as well as dexpanthenol and calcium pantothenate, which ...

  20. Bile acid sequestrants for cholesterol

    MedlinePlus

    Bile acid sequestrants are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can ... block them. These medicines work by blocking bile acid in your stomach from being absorbed in your ...

  1. Omega-3 fatty acids (image)

    MedlinePlus

    Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. ...

  2. Pantothenic acid (Vitamin B5)

    MedlinePlus

    ... D-pantothenic acid, as well as dexpanthenol and calcium pantothenate, which are chemicals made in the lab from ... Early research suggests that pantothenic acid (given as calcium pantothenate) does not reduce symptoms of osteoarthritis. Recovery after ...

  3. Amino acid imbalance in cystinuria

    PubMed Central

    Asatoor, A. M.; Freedman, P. S.; Gabriel, J. R. T.; Milne, M. D.; Prosser, D. I.; Roberts, J. T.; Willoughby, C. P.

    1974-01-01

    After oral ingestion of a free amino acid mixture by three cystinuric patients, plasma increments of lysine and arginine were lower and those of many other amino acids were significantly higher than those found in control subjects. Similar results were obtained in control subjects after amino acid imbalance had been artificially induced by the omission of cystine, lysine, and arginine from the amino acid mixture. Especially high increments of alanine and proline provided the best evidence of amino acid imbalance caused by a temporary lysine and, to a lesser extent, arginine and cystine deficit. No such amino acid imbalance was found to occur in the cystinuric patients after ingestion of whole protein, indicating that absorption of oligopeptides produced by protein digestion provided a balanced physiological serum amino acid increment. This is considered to explain the lack of any unequivocal nutritional deficit in cystinuric patients despite poor absorption of the essential free amino acid, lysine. PMID:4411931

  4. Immunomodulatory spherical nucleic acids

    PubMed Central

    Radovic-Moreno, Aleksandar F.; Chernyak, Natalia; Mader, Christopher C.; Nallagatla, Subbarao; Kang, Richard S.; Hao, Liangliang; Walker, David A.; Halo, Tiffany L.; Merkel, Timothy J.; Rische, Clayton H.; Anantatmula, Sagar; Burkhart, Merideth; Mirkin, Chad A.; Gryaznov, Sergei M.

    2015-01-01

    Immunomodulatory nucleic acids have extraordinary promise for treating disease, yet clinical progress has been limited by a lack of tools to safely increase activity in patients. Immunomodulatory nucleic acids act by agonizing or antagonizing endosomal toll-like receptors (TLR3, TLR7/8, and TLR9), proteins involved in innate immune signaling. Immunomodulatory spherical nucleic acids (SNAs) that stimulate (immunostimulatory, IS-SNA) or regulate (immunoregulatory, IR-SNA) immunity by engaging TLRs have been designed, synthesized, and characterized. Compared with free oligonucleotides, IS-SNAs exhibit up to 80-fold increases in potency, 700-fold higher antibody titers, 400-fold higher cellular responses to a model antigen, and improved treatment of mice with lymphomas. IR-SNAs exhibit up to eightfold increases in potency and 30% greater reduction in fibrosis score in mice with nonalcoholic steatohepatitis (NASH). Given the clinical potential of SNAs due to their potency, defined chemical nature, and good tolerability, SNAs are attractive new modalities for developing immunotherapies. PMID:25775582

  5. Cannabinoid acids analysis.

    PubMed

    Lercker, G; Bocci, F; Frega, N; Bortolomeazzi, R

    1992-03-01

    The cannabinoid pattern of vegetable preparations from Cannabis sativa (hashish, marijuana) allows to recognize the phenotype of the plants, to be used as drug or for fiber. Cannabinoid determination by analytical point of view has represented some problems caused by the complex composition of the hexane extract. Capillary gas chromatography of the hexane extracts of vegetable samples, shows the presence of rather polar constituents that eluted, with noticeable interactions, only on polar phase. The compounds can be methylated by diazomethane and silanized (TMS) by silylating reagents. The methyl and methyl-TMS derivatives are analyzed by high resolution gas chromatography (HRGC) and by gas chromatography-mass spectrometry (GC-MS). The identification of the compounds shows their nature of cannabinoid acids, which the main by quantitative point of view results the cannabidiolic acid (CBDA). It is known that the cannabinoid acids are thermally unstable and are transformed in the corresponding cannabinoids by decarboxilation. This is of interest in forensic analysis with the aim to establish the total amount of THC in the Cannabis preparations, as the active component. PMID:1503600

  6. Hydrodesulfurization Properties of Rhodium Phosphide: Comparison with Rhodium Metal and Sulfide Catalysts

    SciTech Connect

    Hayes, John R.; Bowker, Richard H.; Gaudette, Amy F.; Smith, Mica C.; Moak, Cameron E.; Nam, Charles Y.; Pratum, Thomas K.; Bussell, Mark E.

    2010-12-15

    Silica-supported rhodium phosphide (Rh2P/SiO2) catalysts were prepared and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), 31P solid-state NMR spectroscopy, X-ray photoelectron spectroscopy (XPS), and chemisorption measurements. XRD and TEM analysis of a 5 wt.% Rh2P/SiO2 catalyst confirmed the presence of well-dispersed Rh2P crystallites on the silica support having an average crystallite size of 10 nm. NMR spectroscopy showed unsupported and silica-supported Rh2P to be metallic and XPS spectroscopy yielded a surface composition of Rh1.94P1.00 that is similar to that expected from the bulk stoichiometry. The 5 wt.% Rh2P/SiO2 catalyst exhibited a higher dibenzothiophene (DBT) hydrodesulfurization (HDS) activity than did Rh/SiO2 and sulfided Rh/SiO2 catalysts having a similar Rh loading and was also more active than a commercial NiAMo/Al2O3 catalyst. The Rh2P/SiO2 catalyst showed excellent stability over a 100 h DBT HDS activity measurement and was more S tolerant than the Rh/SiO2 catalyst. The Rh2P/SiO2 catalyst strongly favored the hydrogenation pathway for DBT HDS, while the Rh/SiO2 and sulfided Rh/SiO2 catalysts favored the direct desulfurization pathway.

  7. Adsorptive desulphurization study of liquid fuels using Tin (Sn) impregnated activated charcoal.

    PubMed

    Shah, Syed Sikandar; Ahmad, Imtiaz; Ahmad, Waqas

    2016-03-01

    Keeping in view the growing concern regarding desulphurization of petroleum products, the present study was under taken to investigate the efficiency of tin impregnated activated charcoal (Sn-AC) as a potential adsorbent for the desulphurization of model and real commercial straight run kerosene and diesel oil samples. The adsorbent Sn-AC was prepared by wet impregnation process in the laboratory and characterized by SEM, EDX and surface area analysis. Initial experiments were carried out using model oil, which was prepared by dissolving dibenzothiophene (DBT) in cyclohexane, the optimum conditions for desulfurization were found to be, 60°C temperature, 1h contact time and adsorbent dosage of 0.8g, under which about 99.4% of DBT removal was attained. Under optimized conditions the desulfurization of real oil i.e., kerosene and diesel oil was also investigated. Kinetic studies revealed that DBT adsorption followed pseudo second order kinetics and the data best fits in the Langmuir adsorption isotherm as compared to Freundlich adsorption isotherm model. The adsorbent could be easily regenerated simply by washing with toluene for a multiple cycles and reused without losing its efficiency. PMID:26551224

  8. Acid rain: Reign of controversy

    SciTech Connect

    Kahan, A.M.

    1986-01-01

    Acid Rain is a primer on the science and politics of acid rain. Several introductory chapters describe in simple terms the relevant principles of water chemistry, soil chemistry, and plant physiology and discuss the demonstrated or postulated effects of acid rain on fresh waters and forests as well as on statuary and other exposed objects. There follow discussions on the economic and social implications of acid rain (for example, possible health effects) and on the sources, transport, and distribution of air pollutants.

  9. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C. Judson; Poole, Loree J.

    1995-01-01

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine.

  10. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C.J.; Poole, L.J.

    1995-05-02

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine. 10 figs.

  11. An Umbrella for Acid Rain.

    ERIC Educational Resources Information Center

    Randal, Judith

    1979-01-01

    The Environmental Protection Agency has awarded several grants to study effects of and possible solutions to the problem of "acid rain"; pollution from atmospheric nitric and sulfuric acids. The research program is administered through North Carolina State University at Raleigh and will focus on biological effects of acid rain. (JMF)

  12. BACTERIAL OXIDATION OF DIPICOLINIC ACID

    PubMed Central

    Kobayashi, Yasuo; Arima, Kei

    1962-01-01

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

  13. Pantothenic acid biosynthesis in zymomonas

    SciTech Connect

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  14. Scientists Puzzle Over Acid Rain

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1975

    1975-01-01

    Reports on a growing concern over increased acidity in atmospheric percipitation. Explores possible causes of the increased acidity, identifies chemical components of precipitation in various parts of the world, and presents environmental changes that might be attributed to the acidity. (GS)

  15. Serum Uric Acid in Smokers

    PubMed Central

    Hanna, Bassam E.; Hamed, Jamal M.; Touhala, Luma M.

    2008-01-01

    Objectives To demonstrate the possible effect of smoking on serum uric acid. Methods Subjects enrolled in study were divided into two groups; nonsmokers and smokers, each with 60 male volunteers of the same social class and dietary habit without history of alcohol consumption, diabetes mellitus, hyperuricemia and gout, renal, joint, lung or heart diseases. Fasting blood and random urine samples were obtained from both groups for measurement of uric acid and creatinine. Calculation of both urine uric acid/urine creatinine ratio and fraction excretion of uric acid were done. The results were statistically evaluated by standard statistical methods. Results No significant differences in the age, serum creatinine, spot urine uric acid/urine creatinine ratio and fraction excretion of uric acid between the two groups, serum uric acid was significantly lower in smokers. In smokers there was significant negative correlation of smoking status (average number of cigarette smoked/day, duration of smoking and cumulative amount of smoking) with serum uric acid. Conclusion After exclusion of other factors affecting uric acid level, the significant low serum uric acid level in smokers was attributed to reduce endogenous production as a result of chronic exposure to cigarette smoke that is a significant source of oxidative stress. As this reduction is proportionate with smoking status and predisposes to cardiovascular disease, it is, therefore, recommended for smokers to stop or reduce smoking and introduce serum uric acid estimation as routine test since its cheap and simple to reflect their antioxidant level. Keywords Smokers; Uric acid; CVD. PMID:22334840

  16. Experimental study of the hydrothermal reactivity of organic acids and acid anions: II. Acetic acid, acetate, and valeric acid

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.; Seewald, Jeffrey S.

    2003-10-01

    Organic acids and acid anions occur in substantial concentrations in many aqueous geologic fluids and are thought to take part in a variety of geochemical processes ranging from the transport of metals in ore-forming fluids to the formation of natural gas to serving as a metabolic energy source for microbes in subsurface habitats. The widespread occurrence of organic acids and their potential role in diverse geologic processes has led to numerous experimental studies of their thermal stability, yet there remain substantial gaps in our knowledge of the factors that control the rates and reaction pathways for the decomposition of these compounds under geologic conditions. In order to address some of these uncertainties, a series of laboratory experiments were conducted to examine the behavior of organic acids and acid anions under hydrothermal conditions in the presence of minerals. Reported here are results of experiments where aqueous solutions of acetic acid, sodium acetate, or valeric acid ( n-pentanoic acid) were heated at 325°C, 350 bars in the presence of the mineral assemblages hematite + magnetite + pyrite, pyrite + pyrrhotite + magnetite, and hematite + magnetite. The results indicate that aqueous acetic acid and acetate decompose by a combination of two reaction pathways: decarboxylation and oxidation. Both reactions are promoted by minerals, with hematite catalyzing the oxidation reaction while magnetite catalyzes decarboxylation. The oxidation reaction is much faster, so that oxidation dominates the decomposition of acetic acid and acetate when hematite is present. In contrast to previous reports that acetate decomposed more slowly than acetic acid, we found that acetate decomposed at slightly faster rates than the acid in the presence of minerals. Although longer-chain monocarboxylic acids are generally thought to decompose by decarboxylation, valeric acid appeared to decompose primarily by "deformylation" to 1-butene plus formic acid. Subsequent

  17. Role of acid diffusion in matrix acidizing of carbonates

    SciTech Connect

    Hoefner, M.L.; Fogler, H.S.; Stenius, P.; Sjoblom, J.

    1987-02-01

    To increase the efficiency of matrix treatments in carbonates, a new type of retarded acid-in-oil microemulsion system has ben developed. The microemulsion is of low viscosity but can exhibit acid diffusion rates two orders of magnitude lower than aqueous HCl. Decreased acid diffusion delays spending and allows live acid to penetrate the rock matrix more uniformly and to greater distances. Coreflood results show that the microemulsion can stimulate cores in fewer PV's and under conditions of low injection rates where aqueous HCl fails completely. The microemulsion could also conceivably increase acid penetration along any natural fractures and fissures that may be present, thus increasing acidizing efficiency in this type of treatment. The relationship between the acid diffusion rate and the ability of the fluid to matrix-stimulate limestone is investigated.

  18. Composition for nucleic acid sequencing

    DOEpatents

    Korlach, Jonas; Webb, Watt W.; Levene, Michael; Turner, Stephen; Craighead, Harold G.; Foquet, Mathieu

    2008-08-26

    The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is followed in real time. The sequence is deduced by identifying which base is being incorporated into the growing complementary strand of the target nucleic acid by the catalytic activity of the nucleic acid polymerizing enzyme at each step in the sequence of base additions. A polymerase on the target nucleic acid molecule complex is provided in a position suitable to move along the target nucleic acid molecule and extend the oligonucleotide primer at an active site. A plurality of labelled types of nucleotide analogs are provided proximate to the active site, with each distinguishable type of nucleotide analog being complementary to a different nucleotide in the target nucleic acid sequence. The growing nucleic acid strand is extended by using the polymerase to add a nucleotide analog to the nucleic acid strand at the active site, where the nucleotide analog being added is complementary to the nucleotide of the target nucleic acid at the active site. The nucleotide analog added to the oligonucleotide primer as a result of the polymerizing step is identified. The steps of providing labelled nucleotide analogs, polymerizing the growing nucleic acid strand, and identifying the added nucleotide analog are repeated so that the nucleic acid strand is further extended and the sequence of the target nucleic acid is determined.

  19. Evolution of rosmarinic acid biosynthesis.

    PubMed

    Petersen, Maike; Abdullah, Yana; Benner, Johannes; Eberle, David; Gehlen, Katja; Hücherig, Stephanie; Janiak, Verena; Kim, Kyung Hee; Sander, Marion; Weitzel, Corinna; Wolters, Stefan

    2009-01-01

    Rosmarinic acid and chlorogenic acid are caffeic acid esters widely found in the plant kingdom and presumably accumulated as defense compounds. In a survey, more than 240 plant species have been screened for the presence of rosmarinic and chlorogenic acids. Several rosmarinic acid-containing species have been detected. The rosmarinic acid accumulation in species of the Marantaceae has not been known before. Rosmarinic acid is found in hornworts, in the fern family Blechnaceae and in species of several orders of mono- and dicotyledonous angiosperms. The biosyntheses of caffeoylshikimate, chlorogenic acid and rosmarinic acid use 4-coumaroyl-CoA from the general phenylpropanoid pathway as hydroxycinnamoyl donor. The hydroxycinnamoyl acceptor substrate comes from the shikimate pathway: shikimic acid, quinic acid and hydroxyphenyllactic acid derived from l-tyrosine. Similar steps are involved in the biosyntheses of rosmarinic, chlorogenic and caffeoylshikimic acids: the transfer of the 4-coumaroyl moiety to an acceptor molecule by a hydroxycinnamoyltransferase from the BAHD acyltransferase family and the meta-hydroxylation of the 4-coumaroyl moiety in the ester by a cytochrome P450 monooxygenase from the CYP98A family. The hydroxycinnamoyltransferases as well as the meta-hydroxylases show high sequence similarities and thus seem to be closely related. The hydroxycinnamoyltransferase and CYP98A14 from Coleus blumei (Lamiaceae) are nevertheless specific for substrates involved in RA biosynthesis showing an evolutionary diversification in phenolic ester metabolism. Our current view is that only a few enzymes had to be "invented" for rosmarinic acid biosynthesis probably on the basis of genes needed for the formation of chlorogenic and caffeoylshikimic acid while further biosynthetic steps might have been recruited from phenylpropanoid metabolism, tocopherol/plastoquinone biosynthesis and photorespiration. PMID:19560175

  20. The politics of acid rain

    SciTech Connect

    Wilcher, M.E. )

    1989-01-01

    This work examines and compares the acid rain policies through the different political systems of Canada, Great Britain and the United States. Because the flow of acid rain can transcend national boundaries, acid rain has become a crucial international problem. According to the author, because of differences in governmental institutions and structure, the extent of governmental intervention in the industrial economy, the degree of reliance on coal for power generation, and the extent of acid rain damage, national responses to the acid rain problem have varied.

  1. Invasive cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    1999-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  2. Invasive cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    2002-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  3. Tested Demonstrations: Color Oscillations in the Formic Acid-Nitric Acid-Sulfuric Acid System.

    ERIC Educational Resources Information Center

    Raw, C. J. G.; And Others

    1983-01-01

    Presented are procedures for demonstrating the production of color oscillations when nitric acid is added to a formic acid/concentrated sulfuric acid mixture. Because of safety considerations, "Super-8" home movie of the color changes was found to be satisfactory for demonstration purposes. (JN)

  4. Amino acids in Arctic aerosols

    NASA Astrophysics Data System (ADS)

    Scalabrin, E.; Zangrando, R.; Barbaro, E.; Kehrwald, N. M.; Gabrieli, J.; Barbante, C.; Gambaro, A.

    2012-11-01

    Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids and quantify compounds at fmol m-3 levels. Mean total FAA concentration was 1070 fmol m-3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45-60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m-3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (< 0.49 μm) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanic emissions.

  5. Amino acids in Arctic aerosols

    NASA Astrophysics Data System (ADS)

    Scalabrin, E.; Zangrando, R.; Barbaro, E.; Kehrwald, N. M.; Gabrieli, J.; Barbante, C.; Gambaro, A.

    2012-07-01

    Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids to quantify compounds at fmol m-3 levels. Mean total FAA concentration was 1070 fmol m-3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45-60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m-3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (<0.49 μm) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanics.

  6. Twinning of dodecanedicarboxylic acid

    NASA Technical Reports Server (NTRS)

    Sen, R.; Wilcox, W. R.

    1986-01-01

    Twinning of 1,10-dodecanedicarboxyl acid (DDA) was observed in 0.1 mm thick films with a polarizing microscope. Twins originated from polycrystalline regions which tended to nucleate on twin faces, and terminated by intersection gone another. Twinning increased dramatically with addition of organic compounds with a similar molecular size and shape. Increasing the freezing rate, increasing the temperature gradient, and addition of silica particles increased twinning. It is proposed that twins nucleate with polycrystals and sometimes anneal out before they become observable. The impurities may enhance twinning either by lowering the twin energy or by adsorbing on growing faces.

  7. Synthesis of amino acids

    DOEpatents

    Davis, J.W. Jr.

    1979-09-21

    A method is described for synthesizing amino acids preceding through novel intermediates of the formulas: R/sub 1/R/sub 2/C(OSOC1)CN, R/sub 1/R/sub 2/C(C1)CN and (R/sub 1/R/sub 2/C(CN)O)/sub 2/SO wherein R/sub 1/ and R/sub 2/ are each selected from hydrogen and monovalent hydrocarbon radicals of 1 to 10 carbon atoms. The use of these intermediates allows the synthesis steps to be exothermic and results in an overall synthesis method which is faster than the synthesis methods of the prior art.

  8. Controlling acid rain

    SciTech Connect

    Cannon, J.S.

    1987-01-01

    This book examines recent transfer of electric power among 48 states and present evidence of significant transfers of electric power from so-called ''perpetrator'' to ''victim'' states. The book compares the efforts of several midwestern and northeastern states during the 1970's to control the sulfur dioxide (SO/sub 2/) emissions causing acid rain. The report includes utility and government data on electricity production and sales, on purchase of out-of-state electricity, and on coal use and sulfur dioxide emissions, state by state, for 48 states.

  9. Cryoprotection from lipoteichoic acid

    NASA Astrophysics Data System (ADS)

    Rice, Charles V.; Middaugh, Amy; Wickham, Jason R.; Friedline, Anthony; Thomas, Kieth J.; Johnson, Karen; Zachariah, Malcolm; Garimella, Ravindranth

    2012-10-01

    Numerous chemical additives lower the freezing point of water, but life at sub-zero temperatures is sustained by a limited number of biological cryoprotectants. Antifreeze proteins in fish, plants, and insects provide protection to a few degrees below freezing. Microbes have been found to survive at even lower temperatures, and with a few exceptions, antifreeze proteins are missing. Survival has been attributed to external factors, such as the high salt concentration of brine veins and adhesion to particulates or ice crystal defects. We have discovered an endogenous cryoprotectant in the cell wall of bacteria, lipoteichoic acid biopolymers. Adding 1% LTA to bacteria cultures immediately prior to freezing provides 50% survival rate, similar to the results obtained with 1% glycerol. In the absence of an additive, bacterial survival is negligible as measured with the resazurin cell viability assay. The mode of action for LTA cryoprotection is unknown. With a molecular weight of 3-5 kDa, it is unlikely to enter the cell cytoplasm. Our observations suggest that teichoic acids could provide a shell of liquid water around biofilms and planktonic bacteria, removing the need for brine veins to prevent bacterial freezing.

  10. Nucleic acid detection methods

    DOEpatents

    Smith, C.L.; Yaar, R.; Szafranski, P.; Cantor, C.R.

    1998-05-19

    The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3{prime}-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated. 18 figs.

  11. Nucleic Acid Detection Methods

    DOEpatents

    Smith, Cassandra L.; Yaar, Ron; Szafranski, Przemyslaw; Cantor, Charles R.

    1998-05-19

    The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3'-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated.

  12. Ribonucleic acid purification.

    PubMed

    Martins, R; Queiroz, J A; Sousa, F

    2014-08-15

    Research on RNA has led to many important biological discoveries and improvement of therapeutic technologies. From basic to applied research, many procedures employ pure and intact RNA molecules; however their isolation and purification are critical steps because of the easy degradability of RNA, which can impair chemical stability and biological functionality. The current techniques to isolate and purify RNA molecules still have several limitations and the requirement for new methods able to improve RNA quality to meet regulatory demands is growing. In fact, as basic research improves the understanding of biological roles of RNAs, the biopharmaceutical industry starts to focus on them as a biotherapeutic tools. Chromatographic bioseparation is a high selective unit operation and is the major option in the purification of biological compounds, requiring high purity degree. In addition, its application in biopharmaceutical manufacturing is well established. This paper discusses the importance and the progress of RNA isolation and purification, considering RNA applicability both in research and clinical fields. In particular and in view of the high specificity, affinity chromatography has been recently applied to RNA purification processes. Accordingly, recent chromatographic investigations based on biorecognition phenomena occurring between RNA and amino acids are focused. Histidine and arginine have been used as amino acid ligands, and their ability to isolate different RNA species demonstrated a multipurpose applicability in molecular biology analysis and RNA therapeutics preparation, highlighting the potential contribution of these methods to overcome the challenges of RNA purification. PMID:24951289

  13. Growth of nitric acid hydrates on thin sulfuric acid films

    NASA Technical Reports Server (NTRS)

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-01-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  14. Growth of nitric acid hydrates on thin sulfuric acid films

    NASA Astrophysics Data System (ADS)

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-05-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1 - 3 × 10-4 Torr H2O and 1 - 2.5 × 10-6 Torr HNO3) and subjected to cooling and heating cycles. FTIR spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  15. Interaction of silicic acid with sulfurous acid scale inhibitor

    SciTech Connect

    Gallup, D.L.

    1997-12-31

    The solubility of amorphous silica and the inhibition of silica polymerization in the presence of sulfurous acid and sulfite salts has been investigated to 260{degrees}C. Investigations of inhibition of silica scaling from geothermal brines by sulfurous acid have produced unusual results. Bisulfite/sulfite increases amorphous silica solubility by {open_quotes}salting in{close_quotes} effects resulting from apparent complexation. Silica-sulfite complexes are postulated to form via hydrogen bonding, and appear to be much stronger than silica-sulfate complexes. Treatment of brines with sulfurous acid inhibits silica scaling by (1) retarding the kinetics of silicic acid polymerization, and (2) forming soluble sulfito-silicate complexes. Sulfurous acid offers several advantages over sulfuric acid in controlling scale deposition-reduced corrosion potential, reduced by-product scale formation potential, oxygen scavenging and inhibition of certain metal silicate scales.

  16. Determination of benzoic acid, chlorobenzoic acids and chlorendic acid in water

    SciTech Connect

    Dietz, E.A.; Cortellucci, N.J.; Singley, K.F. )

    1993-01-01

    To characterize and conduct treatment studies of a landfill leachate an analysis procedure was required to determine concentrations of benzoic acid, the three isomers of chlorobenzoic acid and chlorendic acid. The title compounds were isolated from acidified (pH 1) water by extraction with methyl t-butyl ether. Analytes were concentrated by back-extracting the ether with 0.1 N sodium hydroxide which was separated and acidified. This solution was analyzed by C[sub 18] reversed-phase HPLC with water/acetonitrile/acetic acid eluent and UV detection at 222 nm. The method has detection limits of 200 [mu]g/L for chlorendic acid and 100 [mu]g/L for benzoic acid and each isomer of chlorobenzoic acid. Validation studies with water which was fortified with the analytes at concentrations ranging from one to ten times detection limits resulted in average recoveries of >95%.

  17. Acid rain: Rhetoric and reality

    SciTech Connect

    Park, C.C.

    1987-01-01

    Acid rain is now one of the most serious environmental problems in developed countries. Emissions and fallout were previously extremely localized, but since the introduction of tall stacks policies in both Britain and the US - pardoxically to disperse particulate pollutants and hence reduce local damage - emissions are now lifted into the upper air currents and carried long distances downwind. The acid rain debate now embraces many western countries - including Canada, the US, England, Scotland, Wales, Sweden, Norway, Denmark, West Germany, the Netherlands, Austria, Switzerland - and a growing number of eastern countries - including the Soviet Union, Poland, East Germany, and Czechoslovakia. The problem of acid rain arises, strictly speaking, not so much from the rainfall itself as from its effects on the environment. Runoff affects surface water and groundwater, as well as soils and vegetation. Consequently changes in rainfall acidity can trigger off a range of impacts on the chemistry and ecology of lakes and rivers, soil chemistry and processes, the health and productivity of plants, and building materials, and metallic structures. The most suitable solutions to the problems of acid rain require prevention rather than cure, and there is broad agreement in both the political scientific communities on the need to reduce emissions of sulfur and nitrogen oxides to the atmosphere. Book divisions discuss: the problem of acid rain, the science of acid rain, the technology of acid rain, and the politics of acid rain, in an effort to evaluate this growing global problem of acid rain.

  18. Increased formation of ursodeoxycholic acid in patients treated with chenodeoxycholic acid.

    PubMed Central

    Salen, G; Tint, G S; Eliav, B; Deering, N; Mosbach, E H

    1974-01-01

    The formation of ursodeoxycholic acid, the 7 beta-hydroxy epimer of chenodeoxycholic acid, was investigated in three subjects with cerebrotendinous xanthomatosis and in four subjects with gallstones. Total biliary bile acid composition was analyzed by gas-liquid chromatography before and after 4 months of treatment with 0.75 g/day of chenodeoxycholic acid. Individual bile acids were identified by mass spectrometry. Before treatment, bile from cerebrotendinous xanthomatosis (CTX) subjects contained cholic acid, 85%; chenodeoxycholic acid, 7%; deoxycholic acid, 3%; allocholic acid, 3%; and unidentified steroids, 2%; while bile from gallstone subjects contained cholic acid, 45%; chenodeoxycholic acid, 43%; deoxycholic acid, 11%, and lithocholic acid, 1%. In all subjects, 4 months of chenodeoxycholic acid therapy increased the proportion of this bile acid to approximately 80% and decreased cholic acid to 3% of the total biliary bile acids, the remaining 17% of bile acids were identified as ursodeoxycholic acid. After the intravenous injection of [3H]chenodeoxycholic acid, the specific activity of biliary ursodeoxycholic acid exceeded the specific activity of chenodeoxycholic acid, and the resulting specific activity decay curves suggested precursor-product relationships. When [3H]7-ketolithocholic acid was administrated to another patient treated with chenodeoxycholic acid, radioactivity was detected in both the ursodeoxycholic acid and chenodeoxycholic acid fractions. These results indicate that substantial amounts of ursodeoxycholic acid are formed in patients treated with chenodeoxycholic acid. The ursodeoxycholic acid was synthesized from chenodeoxycholic acid presumably via 7-ketolithocholic acid. Images PMID:11344576

  19. Interactions of amino acids, carboxylic acids, and mineral acids with different quinoline derivatives

    NASA Astrophysics Data System (ADS)

    Kalita, Dipjyoti; Deka, Himangshu; Samanta, Shyam Sundar; Guchait, Subrata; Baruah, Jubaraj B.

    2011-03-01

    A series of quinoline containing receptors having amide and ester bonds are synthesized and characterised. The relative binding abilities of these receptors with various amino acids, carboxylic acids and mineral acids are determined by monitoring the changes in fluorescence intensity. Among the receptors bis(2-(quinolin-8-yloxy)ethyl) isophthalate shows fluorescence enhancement on addition of amino acids whereas the other receptors shows fluorescence quenching on addition of amino acids. The receptor N-(quinolin-8-yl)-2-(quinolin-8-yloxy) propanamide has higher binding affinity for amino acids. However, the receptor N-(quinolin-8-yl)-2-(quinolin-8-yloxy)acetamide having similar structure do not bind to amino acids. This is attributed to the concave structure of the former which is favoured due to the presence of methyl substituent. The receptor bis(2-(quinolin-8-yloxy)ethyl) isophthalate do not bind to hydroxy carboxylic acids, but is a good receptor for dicarboxylic acids. The crystal structure of bromide and perchlorate salts of receptor 2-bromo-N-(quinolin-8-yl)-propanamide are determined. In both the cases the amide groups are not in the plane of quinoline ring. The structure of N-(quinolin-8-yl)-2-(quinolin-8-yloxy)acetamide, N-(2-methoxyphenethyl)-2-(quinolin-8-yloxy)acetamide and their salts with maleic acid as well as fumaric acid are determined. It is observed that the solid state structures are governed by the double bond geometry of these two acid. Maleic acid forms salt in both the cases, whereas fumaric acid forms either salt or co-crystals.

  20. Acidity of Strong Acids in Water and Dimethyl Sulfoxide.

    PubMed

    Trummal, Aleksander; Lipping, Lauri; Kaljurand, Ivari; Koppel, Ilmar A; Leito, Ivo

    2016-05-26

    Careful analysis and comparison of the available acidity data of HCl, HBr, HI, HClO4, and CF3SO3H in water, dimethyl sulfoxide (DMSO), and gas-phase has been carried out. The data include experimental and computational pKa and gas-phase acidity data from the literature, as well as high-level computations using different approaches (including the W1 theory) carried out in this work. As a result of the analysis, for every acid in every medium, a recommended acidity value is presented. In some cases, the currently accepted pKa values were revised by more than 10 orders of magnitude. PMID:27115918

  1. 49 CFR 173.158 - Nitric acid.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as... sulfuric acid or hydrochloric acid as impurities, when offered for transportation or transported by rail... 49 Transportation 2 2014-10-01 2014-10-01 false Nitric acid. 173.158 Section...

  2. 49 CFR 173.158 - Nitric acid.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as... sulfuric acid or hydrochloric acid as impurities, when offered for transportation or transported by rail... 49 Transportation 2 2011-10-01 2011-10-01 false Nitric acid. 173.158 Section...

  3. 49 CFR 173.158 - Nitric acid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as... sulfuric acid or hydrochloric acid as impurities, when offered for transportation or transported by rail... 49 Transportation 2 2010-10-01 2010-10-01 false Nitric acid. 173.158 Section...

  4. 49 CFR 173.158 - Nitric acid.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as... sulfuric acid or hydrochloric acid as impurities, when offered for transportation or transported by rail... 49 Transportation 2 2013-10-01 2013-10-01 false Nitric acid. 173.158 Section...

  5. Shaping up nucleic acid computation

    PubMed Central

    Chen, Xi

    2010-01-01

    Summary of recent advances (abstract) Nucleic acid-based nanotechnology has always been perceived as novel, but has begun to move from theoretical demonstrations to practical applications. In particular, the large address spaces available to nucleic acids can be exploited to encode algorithms and/or act as circuits, and thereby process molecular information. In this review we revisit several milestones in the field of nucleic acid-based computation, but also highlight how the prospects for nucleic acid computation go beyond just a large address space. Functional nucleic acid elements (aptamers, ribozymes, and deoxyribozymes) can serve as inputs and outputs to the environment, and can act as logical elements. Into the future, the chemical dynamics of nucleic acids may prove as useful as hybridization for computation. PMID:20538451

  6. Clinical use of acid steatocrit.

    PubMed

    Van den Neucker, A; Pestel, N; Tran, T M; Forget, P P; Veeze, H J; Bouquet, J; Sinaasappel, M

    1997-05-01

    Malabsorption of fat is an important gastrointestinal cause of malnutrition and growth retardation in childhood. The gold standard for the evaluation of fat malabsorption is the faecal fat balance method. The acid steatocrit method has recently been introduced as a simple method to evaluate faecal fat. The present study was aimed at evaluating the acid steatocrit in clinical practice. Faecal fat excretion and acid steatocrit results were determined in 42 children, half with and half without fat malabsorption. Acid steatocrit results correlated significantly with both faecal fat excretion (p < 0.01) and faecal fat concentration (p < 0.001). Sensitivity and specificity of the acid steatocrit for the diagnosis of malabsorption were 90% and 100%, respectively. We consider the acid steatocrit method useful for the screening and monitoring of patients with steatorrhoea. PMID:9183483

  7. Acid rain degradation of nylon

    SciTech Connect

    Kyllo, K.E.

    1984-01-01

    Acid rain, precipitation with a pH less than 5.6, is known to damage lakes, vegetation and buildings. Degradation of outdoor textiles by acid rain is strongly suspected but not well documented. This study reports the effects of sunlight, aqueous acid, heat and humidity (acid rain conditions) on spun delustered nylon 6,6 fabric. Untreated nylon and nylon treated with sulfuric acid of pH 2.0, 3.0, and 4.4 were exposed to light in an Atlas Xenon-arc fadeometer at 63/sup 0/C and 65% R.H. for up to 640 AATCC Fading Units. The untreated and acid treated nylon fabrics were also exposed to similar temperature and humidity condition without light. Nylon degradation was determined by changes in breaking strength, elongation, molecular weight, color, amino end group concentration (NH/sub 2/) and /sup 13/C NMR spectra. Physical damage was assessed using SEM.

  8. A Simpler Nucleic Acid

    NASA Technical Reports Server (NTRS)

    Orgel, Leslie

    2000-01-01

    It has been supposed that for a nucleic acid analog to pair with RNA it must, like RNA, have a backbone with at least a sixatom repeat; a shorter backbone presumably would not stretch far enough to bind RNA properly. The Eschenmoser group has shown, however, that this first impression is incorrect.As they report in their new paper, Eschenmoser and co-workers ( I ) have now synthesized a substantial number of these polymers, which are called (L)-a-threofuranosyl oligonucleotides or TNAs. They are composed of bases linked to a threose sugar-phosphate backbone, with phosphodiester bonds connecting the nucleotides. The investigators discovered that pairs of complementary TNAs do indeed form stable Watson-Crick double helices and, perhaps more importantly, that TNAs form stable double helices with complementary RNAs and DNAs.

  9. Ghrelin and gastric acid secretion

    PubMed Central

    Yakabi, Koji; Kawashima, Junichi; Kato, Shingo

    2008-01-01

    Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-induced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric acid secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion. PMID:19009648

  10. Organic Acids by Ion Chromatography

    NASA Astrophysics Data System (ADS)

    Rich, William E.; Johnson, Edward; Lois, Louis; Stafford, Brian E.; Kabra, Pokar M.; Marton, Laurence J.

    The presence of increased levels of various organic acids in physiological fluids such as serum, plasma, and urine has been correlated with a variety of diseases (1). Although some are rare, others such as lactic acidosis and hyperoxaluria are more widespread (2, 3). The estimation of organic acids in biological fluids has long been an analytical problem owing to the nature of the samples and the hydrophilic behavior of the various acids.

  11. All-trans retinoic acid regulates hepatic bile acid homeostasis

    PubMed Central

    Yang, Fan; He, Yuqi; Liu, Hui-Xin; Tsuei, Jessica; Jiang, Xiaoyue; Yang, Li; Wang, Zheng-Tao; Wan, Yu-Jui Yvonne

    2014-01-01

    Retinoic acid (RA) and bile acids share common roles in regulating lipid homeostasis and insulin sensitivity. In addition, the receptor for RA (retinoid x receptor) is a permissive partner of the receptor for bile acids, farnesoid x receptor (FXR/NR1H4). Thus, RA can activate the FXR-mediated pathway as well. The current study was designed to understand the effect of all-trans RA on bile acid homeostasis. Mice were fed an all-trans RA-supplemented diet and the expression of 46 genes that participate in regulating bile acid homeostasis was studied. The data showed that all-trans RA has a profound effect in regulating genes involved in synthesis and transport of bile acids. All-trans RA treatment reduced the gene expression levels of Cyp7a1, Cyp8b1, and Akr1d1, which are involved in bile acid synthesis. All-trans RA also decreased the hepatic mRNA levels of Lrh-1 (Nr5a2) and Hnf4α (Nr2a1), which positively regulate the gene expression of Cyp7a1 and Cyp8b1. Moreover, all-trans RA induced the gene expression levels of negative regulators of bile acid synthesis including hepatic Fgfr4, Fxr, and Shp (Nr0b2) as well as ileal Fgf15. All-trans RA also decreased the expression of Abcb11 and Slc51b, which have a role in bile acid transport. Consistently, all-trans RA reduced hepatic bile acid levels and the ratio of CA/CDCA, as demonstrated by liquid chromatography-mass spectrometry. The data suggest that all-trans RA-induced SHP may contribute to the inhibition of CYP7A1 and CYP8B1, which in turn reduces bile acid synthesis and affects lipid absorption in the gastrointestinal tract. PMID:25175738

  12. Preparation and characterization Al3+-bentonite Turen Malang for esterification fatty acid (palmitic acid, oleic acid and linoleic acid)

    NASA Astrophysics Data System (ADS)

    Abdulloh, Abdulloh; Aminah, Nanik Siti; Triyono, Mudasir, Trisunaryanti, Wega

    2016-03-01

    Catalyst preparation and characterization of Al3+-bentonite for esterification of palmitic acid, oleic acid and linoleic acid has been done. Al3+-bentonite catalyst was prepared from natural bentonite of Turen Malang through cation exchange reaction using AlCl3 solution. The catalysts obtained were characterized by XRD, XRF, pyridine-FTIR and surface area analyser using the BET method. Catalyst activity test of Al3+-bentonite for esterification reaction was done at 65°C using molar ratio of metanol-fatty acid of 30:1 and 0.25 g of Al3+-bentonite catalyst for the period of ½, 1, 2, 3, 4 and 5 hours. Based on the characterization results, the Al3+-bentonite Turen Malang catalyst has a d-spacing of 15.63 Ǻ, acid sites of Brönsted and Lewis respectively of 230.79 µmol/g and 99.39 µmol/g, surface area of 507.3 m2/g and the average of radius pore of 20.09 Å. GC-MS analysis results of the oil phase after esterification reaction showed the formation of biodiesel (FAME: Fatty acid methyl ester), namely methyl palmitate, methyl oleate and methyl linoleate. The number of conversions resulted in esterification reaction using Al3+-bentonite Turen Malang catalyst was 74.61%, 37.75%, and 20, 93% for the esterification of palmitic acid, oleic acid and linoleic acid respectively.

  13. Acidity of frozen electrolyte solutions.

    PubMed

    Robinson, Carmen; Boxe, C S; Guzman, M I; Colussi, A J; Hoffmann, M R

    2006-04-20

    Ice is selectively intolerant to impurities. A preponderance of implanted anions or cations generates electrical imbalances in ice grown from electrolyte solutions. Since the excess charges are ultimately neutralized via interfacial (H(+)/HO(-)) transport, the acidity of the unfrozen portion can change significantly and permanently. This insufficiently recognized phenomenon should critically affect rates and equilibria in frozen media. Here we report the effective (19)F NMR chemical shift of 3-fluorobenzoic acid as in situ probe of the acidity of extensively frozen electrolyte solutions. The sign and magnitude of the acidity changes associated with freezing are largely determined by specific ion combinations, but depend also on solute concentration and/or the extent of supercooling. NaCl solutions become more basic, those of (NH(4))(2)SO(4) or Na(2)SO(4) become more acidic, while solutions of the 2-(N-morpholino)ethanesulfonic acid zwitterion barely change their acidity upon freezing. We discuss how acidity scales based on solid-state NMR measurements could be used to assess the degree of ionization of weak acids and bases in frozen media. PMID:16610849

  14. Acidic gas capture by diamines

    DOEpatents

    Rochelle, Gary; Hilliard, Marcus

    2011-05-10

    Compositions and methods related to the removal of acidic gas. In particular, the present disclosure relates to a composition and method for the removal of acidic gas from a gas mixture using a solvent comprising a diamine (e.g., piperazine) and carbon dioxide. One example of a method may involve a method for removing acidic gas comprising contacting a gas mixture having an acidic gas with a solvent, wherein the solvent comprises piperazine in an amount of from about 4 to about 20 moles/kg of water, and carbon dioxide in an amount of from about 0.3 to about 0.9 moles per mole of piperazine.

  15. MedlinePlus: Folic Acid

    MedlinePlus

    ... and Tests Homocysteine Test (American Association for Clinical Chemistry) Vitamin B12 and Folate Test (American Association for Clinical Chemistry) Related Issues Folic Acid Supplements: Can They Slow ...

  16. Noncanonical FK506-binding Protein BDBT Binds DBT to Enhance its Circadian Function and Forms Foci at Night

    PubMed Central

    Fan, Jin-Yuan; Agyekum, Boadi; Venkatesan, Anandakrishnan; Hall, David R.; Keightley, Andrew; Bjes, Edward S.; Bouyain, Samuel; Price, Jeffrey L.

    2013-01-01

    SUMMARY The kinase DOUBLETIME is a master regulator of the Drosophila circadian clock, yet the mechanisms regulating its activity remain unclear. A proteomic analysis of DOUBLETIME interactors led to the identification of an unstudied protein designated CG17282. RNAi-mediated knock-down of CG17282 produced behavioral arrhythmicity and long periods, high levels of hypophosphorylated nuclear PERIOD and phosphorylated DOUBLETIME. Overexpression of DOUBLETIME in flies suppresses these phenotypes and overexpression of CG17282 in S2 cells enhances DOUBLETIME-dependent PERIOD degradation, indicating that CG17282 stimulates DOUBLETIME’s circadian function. In photoreceptors, CG17282 accumulates rhythmically in PERIOD- and DOUBLETIME-dependent cytosolic foci. Finally, structural analyses demonstrated CG17282 is a noncanonical FK506-binding protein with an inactive peptide prolyl-isomerase domain that binds DOUBLETIME and tetratricopeptide repeats that may promote assembly of larger protein complexes. We have named CG17282 Bride of Doubletime and established it as a mediator of DOUBLETIME’s effects on PERIOD, most likely in cytosolic foci that regulate PERIOD nuclear accumulation. PMID:24210908

  17. Optimal angular dose distribution to acquire 3D and extra 2D images for digital breast tomosynthesis (DBT)

    NASA Astrophysics Data System (ADS)

    Park, Hye-Suk; Kim, Ye-Seul; Lee, Haeng-Hwa; Gang, Won-Suk; Kim, Hee-Joung; Choi, Young-Wook; Choi, JaeGu

    2015-08-01

    The purpose of this study is to determine the optimal non-uniform angular dose distribution to improve the quality of the 3D reconstructed images and to acquire extra 2D projection images. In this analysis, 7 acquisition sets were generated by using four different values for the number of projections (11, 15, 21, and 29) and total angular range (±14°, ±17.5°, ±21°, and ±24.5° ). For all acquisition sets, the zero-degree projection was used as the 2D image that was close to that of standard conventional mammography (CM). Exposures used were 50, 100, 150, and 200 mR for the zero-degree projection, and the remaining dose was distributed over the remaining projection angles. To quantitatively evaluate image quality, we computed the CNR (contrast-to-noise ratio) and the ASF (artifact spread function) for the same radiation dose. The results indicate that, for microcalcifications, acquisition sets with approximately 4 times higher exposure on the zero-degree projection than the average exposure for the remaining projection angles yielded higher CNR values and were 3% higher than the uniform distribution. However, very high dose concentrations toward the zero-degree projection may reduce the quality of the reconstructed images due to increasing noise in the peripheral views. The zero-degree projection of the non-uniform dose distribution offers a 2D image similar to that of standard CM, but with a significantly lower radiation dose. Therefore, we need to evaluate the diagnostic potential of extra 2D projection image when diagnose breast cancer by using 3D images with non-uniform angular dose distributions.

  18. Bacterial Decarboxylation of o-Phthalic Acids

    PubMed Central

    Taylor, Barrie F.; Ribbons, Douglas W.

    1983-01-01

    The decarboxylation of phthalic acids was studied with Bacillus sp. strain FO, a marine mixed culture ON-7, and Pseudomonas testosteroni. The mixed culture ON-7, when grown anaerobically on phthalate but incubated aerobically with chloramphenicol, quantitatively converted phthalic acid to benzoic acid. Substituted phthalic acids were also decarboxylated: 4,5-dihydroxyphthalic acid to protocatechuic acid; 4-hydroxyphthalic and 4-chlorophthalic acids to 3-hydroxybenzoic and 3-chlorobenzoic acids, respectively; and 3-fluorophthalic acid to 2-and 3-fluorobenzoic acids. Bacillus sp. strain FO gave similar results except that 4,5-dihydroxyphthalic acid was not metabolized, and both 3- and 4-hydroxybenzoic acids were produced from 4-hydroxyphthalic acid. P. testosteroni decarboxylated 4-hydroxyphthalate (to 3-hydroxybenzoate) and 4,5-dihydroxyphthalate but not phthalic acid and halogenated phthalates. Thus, P. testosteroni and the mixed culture ON-7 possessed 4,5-dihydroxyphthalic acid decarboxylase, previously described in P. testosteroni, that metabolized 4,5-dihydroxyphthalic acid and specifically decarboxylated 4-hydroxyphthalic acid to 3-hydroxybenzoic acid. The mixed culture ON-7 and Bacillus sp. strain FO also possessed a novel decarboxylase that metabolized phthalic acid and halogenated phthalates, but not 4,5-dihydroxyphthalate, and randomly decarboxylated 4-hydroxyphthalic acid. The decarboxylation of phthalic acid is suggested to involve an initial reduction to 1,2-dihydrophthalic acid followed by oxidative decarboxylation to benzoic acid. PMID:16346440

  19. Fatty acid-amino acid conjugates diversification in Lepidopteran caterpillars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid amino acid conjugates (FACs) have been found in Noctuid as well as Sphingid caterpillar oral secretions and especially volicitin [N-(17-hydroxylinolenoyl)-L-Glutamine] and its biochemical precursor, N-linolenoyl-L-glutamine, are known elicitors of induced volatile emissions in corn plants...

  20. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances.

    PubMed

    Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung

    2016-01-01

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism. PMID:26742061

  1. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    PubMed Central

    Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung

    2016-01-01

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism. PMID:26742061

  2. A comparison of chromic acid and sulfuric acid anodizing

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1992-01-01

    Because of federal and state mandates restricting the use of hexavalent chromium, it was deemed worthwhile to compare the corrosion protection afforded 2219-T87 aluminum alloy by both Type I chromic acid and Type II sulfuric acid anodizing per MIL-A-8625. Corrosion measurements were made on large, flat 2219-T87 aluminum alloy sheet material with an area of 1 cm(exp 2) exposed to a corrosive medium of 3.5-percent sodium chloride at pH 5.5. Both ac electrochemical impedance spectroscopy and the dc polarization resistance techniques were employed. The results clearly indicate that the corrosion protection obtained by Type II sulfuric acid anodizing is superior, and no problems should result by substituting Type II sulfuric acid anodizing for Type I chromic acid anodizing.

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

    PubMed

    Glasgow, A M; Chase, H P

    1976-07-01

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

  4. Microbial desulfonation of substituted naphthalenesulfonic acids and benzenesulfonic acids.

    PubMed Central

    Zürrer, D; Cook, A M; Leisinger, T

    1987-01-01

    Sulfur-limited batch enrichment cultures containing one of nine multisubstituted naphthalenesulfonates and an inoculum from sewage yielded several taxa of bacteria which could quantitatively utilize 19 sulfonated aromatic compounds as the sole sulfur source for growth. Growth yields were about 4 kg of protein per mol of sulfur. Specific degradation rates were about 4 to 14 mu kat/kg of protein. A Pseudomonas sp., an Arthrobacter sp., and an unidentified bacterium were examined. Each desulfonated at least 16 aromatic compounds, none of which served as a carbon source. Pseudomonas sp. strain S-313 converted 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, benzenesulfonic acid, and 3-aminobenzenesulfonic acid to 1-naphthol, 2-naphthol, 5-amino-1-naphthol, phenol, and 3-aminophenol, respectively. Experiments with 18O2 showed that the hydroxyl group was derived from molecular oxygen. PMID:3662502

  5. Carbonic Acid Retreatment of Biomass

    SciTech Connect

    Baylor university

    2003-06-01

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for

  6. Carbonic Acid Pretreatment of Biomass

    SciTech Connect

    G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

    2003-05-31

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic

  7. Anacardic Acid, Salicylic Acid, and Oleic Acid Differentially Alter Cellular Bioenergetic Function in Breast Cancer Cells.

    PubMed

    Radde, Brandie N; Alizadeh-Rad, Negin; Price, Stephanie M; Schultz, David J; Klinge, Carolyn M

    2016-11-01

    Anacardic acid is a dietary and medicinal phytochemical that inhibits breast cancer cell proliferation and uncouples oxidative phosphorylation (OXPHOS) in isolated rat liver mitochondria. Since mitochondrial-targeted anticancer therapy (mitocans) may be useful in breast cancer, we examined the effect of anacardic acid on cellular bioenergetics and OXPHOS pathway proteins in breast cancer cells modeling progression to endocrine-independence: MCF-7 estrogen receptor α (ERα)+ endocrine-sensitive; LCC9 and LY2 ERα+, endocrine-resistant, and MDA-MB-231 triple negative breast cancer (TNBC) cells. At concentrations similar to cell proliferation IC50 s, anacardic acid reduced ATP-linked oxygen consumption rate (OCR), mitochondrial reserve capacity, and coupling efficiency while increasing proton leak, reflecting mitochondrial toxicity which was greater in MCF-7 compared to endocrine-resistant and TNBC cells. These results suggest tolerance in endocrine-resistant and TNBC cells to mitochondrial stress induced by anacardic acid. Since anacardic acid is an alkylated 2-hydroxybenzoic acid, the effects of salicylic acid (SA, 2-hydroxybenzoic acid moiety) and oleic acid (OA, monounsaturated alkyl moiety) were tested. SA inhibited whereas OA stimulated cell viability. In contrast to stimulation of basal OCR by anacardic acid (uncoupling effect), neither SA nor OA altered basal OCR- except OA inhibited basal and ATP-linked OCR, and increased ECAR, in MDA-MB-231 cells. Changes in OXPHOS proteins correlated with changes in OCR. Overall, neither the 2-hydroxybenzoic acid moiety nor the monounsaturated alky moiety of anacardic acid is solely responsible for the observed mitochondria-targeted anticancer activity in breast cancer cells and hence both moieties are required in the same molecule for the observed effects. J. Cell. Biochem. 117: 2521-2532, 2016. © 2016 Wiley Periodicals, Inc. PMID:26990649

  8. Production of Succinic Acid from Citric Acid and Related Acids by Lactobacillus Strains

    PubMed Central

    Kaneuchi, Choji; Seki, Masako; Komagata, Kazuo

    1988-01-01

    A number of Lactobacillus strains produced succinic acid in de Man-Rogosa-Sharpe broth to various extents. Among 86 fresh isolates from fermented cane molasses in Thailand, 30 strains (35%) produced succinic acid; namely, 23 of 39 Lactobacillus reuteri strains, 6 of 18 L. cellobiosus strains, and 1 of 6 unidentified strains. All of 10 L. casei subsp. casei strains, 5 L. casei subsp. rhamnosus strains, 6 L. mali strains, and 2 L. buchneri strains did not produce succinic acid. Among 58 known strains including 48 type strains of different Lactobacillus species, the strains of L. acidophilus, L. crispatus, L. jensenii, and L. parvus produced succinic acid to the same extent as the most active fresh isolates, and those of L. alimentarius, L. collinoides, L. farciminis, L. fructivorans (1 of 2 strains tested), L. malefermentans, and L. reuteri were also positive, to lesser extents. Diammonium citrate in de Man-Rogosa-Sharpe broth was determined as a precursor of the succinic acid produced. Production rates were about 70% on a molar basis with two fresh strains tested. Succinic acid was also produced from fumaric and malic acids but not from dl-isocitric, α-ketoglutaric, and pyruvic acids. The present study is considered to provide the first evidence on the production of succinic acid, an important flavoring substance in dairy products and fermented beverages, from citrate by lactobacilli. PMID:16347795

  9. Acid rain: effects on fish and wildlife

    SciTech Connect

    Mayer, K.S.; Multer, E.P.; Schreiber, R.K.

    1984-01-01

    The following questions concerning acid rain are discussed: what is acid rain; what causes acid rain; where do sulfur and nitrogen oxides originate; what areas in the U.S. are susceptible to acid rain; are there early warning signals of acidification to aquatic resources; how does acid rain affect fishery resources; does acid rain affect wildlife; and how can effects of acid rain be reduced.

  10. Synthesis of (+) and (-)-phaselic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    (2S)-Phaselic acid (2S-O-caffeoylmalate) is a common plant metabolite belonging to the o-diphenol subclass of phenolic secondary metabolites. Our interest in this metabolite stems from previous studies showing that the presence of (2S)-phaselic acid in red clover is crucial to the preservation of ut...

  11. Synthesis of (+)- and (-)-phaselic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    (2S)-Phaselic acid (2S-O-caffeoylmalate) is a common plant metabolite belonging to the o-diphenol subclass of phenolic secondary metabolites. Our interest in this metabolite stems from previous studies showing that the presence of (2S)-phaselic acid in red clover is crucial to the preservation of ut...

  12. BOTANICAL ASPECTS OF ACIDIC PRECIPITATION

    EPA Science Inventory

    Acidic precipitation can be characterized as wet or frozen atmospheric deposition with a hydrogen ion concentration greater than 2.5 microequivalents liter-1. Acidic precipitation is perceived as a significant air pollution problem derived chiefly from combustion of fossil fuels,...

  13. SOIL REACTION AND ACIDIC DEPOSITION

    EPA Science Inventory

    This chapter discusses the major chemical processes by which acidic deposition interacts with soils. he focus is on forest soils, as the effects of acidic deposition on soils used for production of food and fiber are generally small compared to effects of agricultural practices s...

  14. Acid Rain: The Scientific Challenge.

    ERIC Educational Resources Information Center

    Godfrey, Paul J.

    1991-01-01

    Documents the workings and findings of the Massachusetts Acid Rain Monitoring Project, which has pooled the volunteer efforts of more than 1,000 amateur and professional scientists since 1983. Reports on the origins of air pollution, the prediction of acid rain, and its effects on both water life and land resources. (JJK)

  15. Acid Rain: An Educational Opportunity?

    ERIC Educational Resources Information Center

    Marion, James I.

    1984-01-01

    Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

  16. Acid Rain: What's the Forecast?

    ERIC Educational Resources Information Center

    Bybee, Rodger

    1984-01-01

    Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)

  17. Acid rain & electric utilities II

    SciTech Connect

    1997-12-31

    This document presents reports which were presented at the Acid Rain and Electric Utilities Conference. Topics include environmental issues and electric utilities; acid rain program overview; global climate change and carbon dioxide; emissions data management; compliance; emissions control; allowance and trading; nitrogen oxides; and assessment. Individual reports have been processed separately for the United States Department of Energy databases.

  18. Acid Precipitation: Causes and Consequences.

    ERIC Educational Resources Information Center

    Babich, Harvey; And Others

    1980-01-01

    This article is the first of three articles in a series on the acid rain problem in recent years. Discussed are the causes of acid precipitation and its consequences for the abiotic and biotic components of the terrestrial and aquatic ecosystems, and for man-made materials. (Author/SA)

  19. TRANS ACIDS IN SPECIALTY LIPIDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The role of trans acids in human health and nutrition is highly controversial and a search of the Internet reveals the interest in the subject. Trans acids are perceived as "killer fats" at one end of the spectrum to having no adverse effects at the other. In addition, saturated fats are perceived...

  20. Acid precipitation in historical perspective

    SciTech Connect

    Cowling, E.B.

    1982-02-01

    The history of acid precipitation is traced from the first awareness of the problem in the mid-17th century to the present. An outline of the National Acid Precipitation Assessment program is also given, and the author makes recommendations for future research. (JMT)

  1. SIMULATED ACID RAIN ON CROPS

    EPA Science Inventory

    In 1981, simulated H2SO4 acid rain was applied to alfalfa and tall fescue and a 2:1 ratio of H2SO4:HNO3 acid rain was applied to alfalfa, tall fescue, barley, wheat, potato, tomato, radish, and corn crops growing in the open field at Corvallis, Oregon. Careful attention was given...

  2. Acid rain: a background report

    SciTech Connect

    Glustrom, L.; Stolzenberg, J.

    1982-07-08

    This Staff Brief was prepared for the Wisconsin Legislative Council's Special Committee on Acid Rain to provide an introduction to the issue of acid rain. It is divided into four parts. Part I provides an overview on the controversies surrounding the measurement, formation and effects of acid rain. As described in Part I, the term acid rain is used to describe the deposition of acidic components through both wet deposition (e.g., rain or snow) and dry deposition (e.g., direct contact between atmospheric constituents and the land, water or vegetation of the earth). Part II presents background information on state agency activities relating to acid rain in Wisconsin, describes what is known about the occurrence of, susceptibility to and effects of acid rain in Wisconsin, and provides information related to man-made sources of sulfur and nitrogen oxides in Wisconsin. Part III describes major policies and regulations relating to acid rain which have been or are being developed jointly by the United States and Canadian governments, by the United States government and by the State of Wisconsin. Part IV briefly discusses possible areas for Committee action.

  3. Getting Back to Basics (& Acidics)

    ERIC Educational Resources Information Center

    Rhodes, Sam

    2006-01-01

    This article describes a few novel acid-base experiments intended to introduce students to the basic concepts of acid-base chemistry and provide practical examples that apply directly to the study of biology and the human body. Important concepts such as the reaction between carbon dioxide and water, buffers and protein denaturation, are covered.…

  4. ACID DEPOSITION AND FOREST DECLINE

    EPA Science Inventory

    The location, topography and other characteristics of the high-elevation forests of eastern North America cause them to be receptors of high levels of acid deposition and airborn trace metals. No other major forested areas in the U.S. are subjected to such intensely acid cloud mo...

  5. Acid Tests and Basic Fun.

    ERIC Educational Resources Information Center

    McBride, John W.

    1995-01-01

    Explores acids and bases using different indicators, such as turmeric, purple grape juice, and lichens. Because some of these indicators are not as sensitive as cabbage juice or litmus paper, determining to which acids and bases each indicator is sensitive presents an enjoyable, problem-solving challenge for students. Presents directions for…

  6. Synthesis of pyromellitic acid esters

    NASA Technical Reports Server (NTRS)

    Fedorova, V. A.; Donchak, V. A.; Martynyuk-Lototskaya, A. N.

    1985-01-01

    The ester acids necessary for studyng the thermochemical properties of pyromellitic acid (PMK)-based peroxides were investigated. Obtaining a tetramethyl ester of a PMK was described. The mechanism of an esterification reaction is discussed, as is the complete esterification of PMK with primary alcohol.

  7. Research on Identification and Screen of Microbial Desulfurization Strains for Petroleum

    NASA Astrophysics Data System (ADS)

    Xiaojuan, Tian; Lingtian, Tang; Li'e, Peng; Xinghong, Li

    The oil-contaminated soil sample was acquired from Shengli Oilfield and Jidong Oilfield and cultured with enrichment technology. Then 21 desulfurization strains were separated from the sample, from which a high efficiency desulfurization strain TV9704 was selected. The strain could neither grow with n-dodecane, n-hexadecane, liquid paraffin, naphthalene or diesel as a carbon source and energy source, nor obviously reduce oil combustion value. It could use thiophene or dibenzothiophene (DBT) as the sole sulfur source. In the experiment, the concentrations of thiophene and DBT were measured by UV spectrophotometer. After being cultured in the culture medium with an initial concentration of 63.2 mmol/L respectively for 48 h and 144 h, the degradation rates of the strain TV9704 on thiophene were 39.0% and 63.8%; the DBT with an initial concentration of 2.7 mmol/L was degraded by 1.46 mmol/L after cultured for 72 h. When sodium acetate and glycerol were chosen as carbon source, the ethanol could enhance the degradation rate of TV9704 on DBT significantly. Strain TV9704 was identified by China Industrial Culture Collection Center (CICC) as a Bacillus sp., Gram-positive, obligate aerobic, which forms a circular orange colony on the nutrition gravy plate. The 16SrDNA gene sequencing test and analysis was carried out on strain TV9704, finding that its homologies with the most similar species Bacillus aquimaris and Bacillus marisflavi were 99.2% and 98.2% respectively, but a larger difference existed between their cell morphological characteristics and physiological and biochemical characteristics, therefore strain TV9704 may be a new species because it was impossible to be categorized to any population.

  8. Fischer-Tropsch synthesis in slurry reactor systems. Quarterly report, November 1, 1983-January 31, 1984

    SciTech Connect

    Satterfield, C.N.; Bartos, T.; Hanlon, R.; Matsumoto, D.; Stenger, H.

    1984-01-01

    We have now completed and partially analyzed a series of studies on the effects of the nature of the liquid present on activity and seletivity of the Fischer-Tropsch synthesis, and the effects of partial poisoning of the catalyst by H/sub 2/S or dibenzothiophene (DBT). We discovered that the presence of a small amount of DBT (97.8 mg S per g of Fe in the catalyst) cut methane formation nearly in half under a set of reaction conditions of commercial importance (263/sup 0/C, 1.48 MPa, H/sub 2//CO feed ratio = 0.69). The selectivity remained constant for at least 200 hours. This is a very important finding since reduction of methane formation is highly desirable. The catalyst activity simultaneously dropped ten-fold but it should be possible to compensate for this in other ways at least in part such as by operation at higher pressure and/or temperature. Alternately, it may develop that lesser levels of catalyst poisoning may be nearly as effective with less loss of activity. These effects are not observed with H/sub 2/S. As far as we know the effects caused by DBT are brand new and have not been observed before. We plan to exploit this lead in several ways, including optimization of DBT level and reaction conditions; study of other heterocyclic sulfur compounds, effects of activation procedures and correlation of methane selectivity with catalyst carbiding as determined by Mossbauer spectroscopy. Also of some importance was the observation that operation in the presence of an aromatic liquid (phenanthrene) increased the rate of reaction by a factor of 1.5 to 1.8, everything else being held constant.

  9. Changes in biomarker abundances and sulfur isotopes of pyrite across the Permian Triassic (P/Tr) Schuchert Dal section (East Greenland)

    NASA Astrophysics Data System (ADS)

    Fenton, Stephen; Grice, Kliti; Twitchett, Richard J.; Böttcher, Michael E.; Looy, Cindy V.; Nabbefeld, Birgit

    2007-10-01

    In this study, we report on biomarker abundances through parts of the Permian/Triassic boundary (PTB) of Schuchert Dal (East Greenland) that contains rich marine faunal records and excellent terrestrial palynological records. Biomarker abundances and sulfur isotopes are used to correlate the series of events (including changes in element cycling and associated redox conditions of the ocean) surrounding the collapse of the marine and terrestrial ecosystems through this record of a major crisis of life on Earth during a mass extinction episode. The Upper Schuchert Dal Formation contains a low diversity palynological assemblage, ascribed to arborescent cordiaite-conifer-pteridosperm vegetation. Samples from this pre-collapse interval are characterised by high abundances of dibenzofuran (DBF), dibenzothiophene (DBT) and biphenyl. Since these compounds have similar base structures, and show comparable abundance curves, it is plausible that they probably derive from a common source. We propose that phenolic compounds of lignin of the woody plants present during this period could be the source for DBF, DBT and biphenyl. The redox conditions during this period of time also support the formation of DBF and DBT. Just above the extinction interval, there is a dramatic decrease in the abundances of DBF and DBT which occurs at the same time as a sudden change in the stable sulfur isotopic composition ( δ34S) of pyrite, indicating a change in redox conditions from oxic to anoxic/euxinic conditions. δ34S values leading up to the extinction are highly depleted in the heavy sulfur isotope (about - 40‰ vs. VCDT), whilst shortly after the extinction interval much more positive isotope values are observed (about - 25‰). An inferred change in the biogeochemical sulfur cycle is supported by facies evidence from similar neighbouring sections. It is suggested that two processes are operating closely here; 1) Changes in redox conditions and 2) extinction and/or transgression

  10. Modification of C/TiO2@MCM-41 with nickel nanoparticles for photocatalytic desulfurization enhancement of a diesel fuel model under visible light.

    PubMed

    Zarrabi, M; Entezari, M H

    2015-11-01

    Ni metal nanoparticles were attached on the C/TiO2@MCM-41 (CTM-41) via facile and fast method based on dispersing of C/TiO2@MCM-41 in aqueous solution containing nickel ions by ultrasonic bath. Then, for the first time, the Ni ions were converted to Ni nanoparticles under UV light (photo-assisted deposition, PAD method), without using reducing agents and hydrogen gas. This process was carried out under the relatively mild conditions. The results showed that Ni (II) was reduced to Ni metallic nanoparticle in the size of about 2.7 nm on the surface of CTM-41 (Ni/CTM-41) with specific surface area of 754.37 m(2) g(-1). The photocatalytic ultra-deep desulfurization of a fuel-like n-octane containing dibenzothiophene (DBT) was conducted over the Ni/CTM-41 nanophotocatalyst. Using this method, the total sulfur content efficiently decreased under mild conditions in one phase and without using an oxidant. The synthesized Ni/CTM-41 (3% Ni) exhibited the maximum photocatalytic desulfurization of DBT for all different ratios of Si/Ti. In contrast, the synthesized CTM-41 (without Ni) exhibited the maximum photocatalytic desulfurization of DBT only for minimum ratio of Si/Ti. The Ni/CTM-41 was characterized by several techniques including N2 adsorption-desorption isotherms, XRD, TEM, and atomic absorption spectroscopy techniques. The results confirmed that Ni was highly dispersed on the support phase. The GC-MS analysis confirmed the photocatalytic removal of DBT. Based on the experimental results, it is proposed that the hydroxyl radical and hole have key role in the photocatalytic desulfurization process. PMID:26196719

  11. Lead-acid battery

    SciTech Connect

    Rowlette, J.J.

    1983-09-20

    A light weight lead-acid battery is disclosed having a positive terminal and a negative terminal and including one or more cells or grid stacks having a plurality of vertically stacked conductive monoplates with positive active material and negative active material deposited on alternating plates in the cell or grid stack. Electrolyte layers positioned between each monoplate are included to provide a battery cell having four sides which is capable of being electrically charged and discharged. Two vertical positive bus bars are provided on opposite sides of the battery cell for connecting the monoplates with positive active material together in parallel current conducting relation. In addition, two negative bus bars on opposite sides of the battery cell each being adjacent the positive bus bars are provided for connecting the monoplates with negative active material together in parallel current conducting relation. The positive and negative bus bars not only provide a low resistance method for connecting the plurality of conductive monoplates of their respective battery terminals but also provides support and structural strength to the battery cell structure. In addition, horizontal orientation of monoplates is provided in a vertical stacking arrangement to reduce electrolyte stratification and short circuiting due to flaking of positive and negative active materials from the monoplates.

  12. Lead-acid battery

    NASA Technical Reports Server (NTRS)

    Rowlette, John J. (Inventor)

    1983-01-01

    A light weight lead-acid battery (30) having a positive terminal (36) and a negative terminal (34) and including one or more cells or grid stacks having a plurality of vertically stacked conductive monoplates (10, 20) with positive active material and negative active material deposited on alternating plates in the cell or grid stack. Electrolyte layers (26, 28) positioned between each monoplate are included to provide a battery cell having four sides which is capable of being electrically charged and discharged. Two vertical positive bus bars (42, 43) are provided on opposite sides of the battery cell for connecting the monoplates (10) with positive active material together in parallel current conducting relation. In addition, two negative bus bars (38, 39) on opposite sides of the battery cell each being adjacent the positive bus bars are provided for connecting the monoplates (20) with negative active material together in parallel current conducting relation. The positive (42, 43) and negative (38, 39) bus bars not only provide a low resistance method for connecting the plurality of conductive monoplates of their respective battery terminals (36, 34) but also provides support and structural strength to the battery cell structure. In addition, horizontal orientation of monoplates (10, 20) is provided in a vertical stacking arrangement to reduce electrolyte stratification and short circuiting due to flaking of positive and negative active materials from the monoplates.

  13. Atmospheric dust and acid rain

    SciTech Connect

    Hedin, L.O.; Likens, G.E.

    1996-12-01

    Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid rain and atmospheric dust? Suggestions range from the improbable to the feasible. One reasonable suggestion is to reduce emissions of acidic pollutants to levels that can be buffered by natural quantities of basic compounds in the atmosphere; such a goal would mean continued reductions in sulfur dioxide and nitrogen oxides, perhaps even greater than those prescribed in the 1990 Amendments to the Clean Air Act in the U.S. 5 figs.

  14. Microfluidics in amino acid analysis.

    PubMed

    Pumera, Martin

    2007-07-01

    Microfluidic devices have been widely used to derivatize, separate, and detect amino acids employing many different strategies. Virtually zero-dead volume interconnections and fast mass transfer in small volume microchannels enable dramatic increases in on-chip derivatization reaction speed, while only minute amounts of sample and reagent are needed. Due to short channel path, fast subsecond separations can be carried out. With sophisticated miniaturized detectors, the whole analytical process can be integrated on one platform. This article reviews developments of lab-on-chip technology in amino acid analysis, it shows important design features such as sample preconcentration, precolumn and postcolumn amino acid derivatization, and unlabeled and labeled amino acid detection with focus on advanced designs. The review also describes important biomedical and space exploration applications of amino acid analysis on microfluidic devices. PMID:17542043

  15. Synthesis of higher monocarboxylic acids

    SciTech Connect

    Taikov, B.F.; Novakovskii, E.M.; Zhelkovskaya, V.P.; Shadrova, V.N.; Shcherbik, P.K.

    1981-01-01

    Brown-coal and peat waxes contain higher monocarboxylic acids, alcohols and esters of them as their main components. In view of this, considerable interest is presented by the preparation of individual compounds among those mentioned above, which is particularly important in the study of the composition and development of the optimum variants of the chemical processing of the waxes. In laboratory practice, to obtain higher monocarboxylic acids use is generally made of electrosynthesis according to Kolbe which permits unbranched higher aliphatic acids with given lengths of the hydrocarbon chain to be obtained. The aim of the present work was to synthesize higher monocarboxylic acids: arachidic, behenic, lignoceric, pentacosanoic, erotic, heptacosanoic, montanic, nonacosanoic, melissic, dotriacontanoic and tetratriacontanoic, which are present in waxes. Characteristics of synthesized acids are tabulated. 20 refs.

  16. Fumaric acid production by fermentation

    PubMed Central

    Roa Engel, Carol A.; Zijlmans, Tiemen W.; van Gulik, Walter M.; van der Wielen, Luuk A. M.

    2008-01-01

    The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical process yields 112% w/w fumaric acid from maleic anhydride and the fermentation process yields only 85% w/w from glucose, the latter raw material is three times cheaper. Besides, the fermentation fixes CO2. Production of fumaric acid by Rhizopus species and the involved metabolic pathways are reviewed. Submerged fermentation systems coupled with product recovery techniques seem to have achieved economically attractive yields and productivities. Future prospects for improvement of fumaric acid production include metabolic engineering approaches to achieve low pH fermentations. PMID:18214471

  17. Sialic acids and autoimmune disease.

    PubMed

    Mahajan, Vinay S; Pillai, Shiv

    2016-01-01

    An important underlying mechanism that contributes to autoimmunity is the loss of inhibitory signaling in the immune system. Sialic acid-recognizing Ig superfamily lectins or Siglecs are a family of cell surface proteins largely expressed in hematopoietic cells. The majority of Siglecs are inhibitory receptors expressed in immune cells that bind to sialic acid-containing ligands and recruit SH2-domain-containing tyrosine phosphatases to their cytoplasmic tails. They deliver inhibitory signals that can contribute to the constraining of immune cells, and thus protect the host from autoimmunity. The inhibitory functions of CD22/Siglec-2 and Siglec-G and their contributions to tolerance and autoimmunity, primarily in the B lymphocyte context, are considered in some detail in this review. The relevance to autoimmunity and unregulated inflammation of modified sialic acids, enzymes that modify sialic acid, and other sialic acid-binding proteins are also reviewed. PMID:26683151

  18. Nucleic acid based molecular devices.

    PubMed

    Krishnan, Yamuna; Simmel, Friedrich C

    2011-03-28

    In biology, nucleic acids are carriers of molecular information: DNA's base sequence stores and imparts genetic instructions, while RNA's sequence plays the role of a messenger and a regulator of gene expression. As biopolymers, nucleic acids also have exciting physicochemical properties, which can be rationally influenced by the base sequence in myriad ways. Consequently, in recent years nucleic acids have also become important building blocks for bottom-up nanotechnology: as molecules for the self-assembly of molecular nanostructures and also as a material for building machinelike nanodevices. In this Review we will cover the most important developments in this growing field of nucleic acid nanodevices. We also provide an overview of the biochemical and biophysical background of this field and the major "historical" influences that shaped its development. Particular emphasis is laid on DNA molecular motors, molecular robotics, molecular information processing, and applications of nucleic acid nanodevices in biology. PMID:21432950

  19. Molten fatty acid based microemulsions.

    PubMed

    Noirjean, Cecile; Testard, Fabienne; Dejugnat, Christophe; Jestin, Jacques; Carriere, David

    2016-06-21

    We show that ternary mixtures of water (polar phase), myristic acid (MA, apolar phase) and cetyltrimethylammonium bromide (CTAB, cationic surfactant) studied above the melting point of myristic acid allow the preparation of microemulsions without adding a salt or a co-surfactant. The combination of SANS, SAXS/WAXS, DSC, and phase diagram determination allows a complete characterization of the structures and interactions between components in the molten fatty acid based microemulsions. For the different structures characterized (microemulsion, lamellar or hexagonal phases), a similar thermal behaviour is observed for all ternary MA/CTAB/water monophasic samples and for binary MA/CTAB mixtures without water: crystalline myristic acid melts at 52 °C, and a thermal transition at 70 °C is assigned to the breaking of hydrogen bounds inside the mixed myristic acid/CTAB complex (being the surfactant film in the ternary system). Water determines the film curvature, hence the structures observed at high temperature, but does not influence the thermal behaviour of the ternary system. Myristic acid is partitioned in two "species" that behave independently: pure myristic acid and myristic acid associated with CTAB to form an equimolar complex that plays the role of the surfactant film. We therefore show that myristic acid plays the role of a solvent (oil) and a co-surfactant allowing the fine tuning of the structure of oil and water mixtures. This solvosurfactant behaviour of long chain fatty acid opens the way for new formulations with a complex structure without the addition of any extra compound. PMID:27241163

  20. Acid soil and acid rain, 2nd edition

    SciTech Connect

    Kennedy, I.R.

    1992-01-01

    This book examines the basic chemical processes involved in acidification in order to better assess their long-term effects on the status of soils, the health of plants and other living species that depend on them. It also discusses acidity, pH and protons their significance in bioenergetics and the consequent role of autotrophic organisms in acidifying ecosystems. This edition incorporates and integrates recent findings that render more explanations of the causes of the environmental impacts of acidity, especially in forests and lakes. Also explores current research into acid rain and soil in order to devise appropriate measures for their amelioration.

  1. Functional nucleic acid probes and uses thereof

    DOEpatents

    Nilsen-Hamilton, Marit

    2006-10-03

    The present invention provides functional nucleic acid probes, and methods of using functional nucleic acid probes, for binding a target to carry out a desired function. The probes have at least one functional nucleic acid, at least one regulating nucleic acid, and at least one attenuator. The functional nucleic acid is maintained in an inactive state by the attenuator and activated by the regulating nucleic acid only in the presence of a regulating nucleic acid target. In its activated state the functional nucleic acid can bind to its target to carry out a desired function, such as generating a signal, cleaving a nucleic acid, or catalyzing a reaction.

  2. Polyglycolic acid induced inflammation

    PubMed Central

    Ceonzo, Kathleen; Gaynor, Anne; Shaffer, Lisa; Kojima, Koji; Vacanti, Charles A.; Stahl, Gregory L.

    2005-01-01

    Tissue and organ replacement have quickly outpaced available supply. Tissue bioengineering holds the promise for additional tissue availability. Various scaffolds are currently used, whereas polyglycolic acid (PGA), which is currently used in absorbable sutures and orthopedic pins, provides an excellent support for tissue development. Unfortunately, PGA can induce a local inflammatory response following implantation, so we investigated the molecular mechanism of inflammation in vitro and in vivo. Degraded PGA induced an acute peritonitis, characterized by neutrophil (PMN) infiltration following intraperitoneal injection in mice. Similar observations were observed using the metabolite of PGA, glycolide. Dissolved PGA or glycolide, but not native PGA, activated the classical complement pathway in human sera, as determined by classical complement pathway hemolytic assays, C3a and C5a production, C3 and immunoglobulin deposition. To investigate whether these in vitro observations translated to in vivo findings, we used genetically engineered mice. Intraperitoneal administration of glycolide or dissolved PGA in mice deficient in C1q, factor D, C1q and factor D or C2 and factor B demonstrated significantly reduced PMN infiltration compared to congenic controls (WT). Mice deficient in C6 also demonstrated acute peritonitis. However, treatment of WT or C6 deficient mice with a monoclonal antibody against C5 prevented the inflammatory response. These data suggest that the hydrolysis of PGA to glycolide activates the classical complement pathway. Further, complement is amplified via the alternative pathway and inflammation is induced by C5a generation. Inhibition of C5a may provide a potential therapeutic approach to limit the inflammation associated with PGA derived materials following implantation. PMID:16548688

  3. 21 CFR 189.155 - Monochloroacetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Monochloroacetic acid. 189.155 Section 189.155... Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid... in alcoholic and nonalcoholic beverages. Monochloroacetic acid is permitted in food package...

  4. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Benzoic acid. 184.1021 Section 184.1021 Food and... Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7H6O2), occurring in nature in free and combined forms. Among the foods in which benzoic acid...

  5. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food and....1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7H6O2), occurring in nature in free and combined forms. Among the foods in which benzoic acid occurs naturally are...

  6. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food and... Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7H6O2), occurring in nature in free and combined forms. Among the foods in which benzoic acid...

  7. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food and... Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7H6O2), occurring in nature in free and combined forms. Among the foods in which benzoic acid...

  8. 21 CFR 184.1021 - Benzoic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food and... Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7H6O2), occurring in nature in free and combined forms. Among the foods in which benzoic acid...

  9. Cycloadditions for Studying Nucleic Acids.

    PubMed

    Kath-Schorr, Stephanie

    2016-02-01

    Cycloaddition reactions for site-specific or global modification of nucleic acids have enabled the preparation of a plethora of previously inaccessible DNA and RNA constructs for structural and functional studies on naturally occurring nucleic acids, the assembly of nucleic acid nanostructures, therapeutic applications, and recently, the development of novel aptamers. In this chapter, recent progress in nucleic acid functionalization via a range of different cycloaddition (click) chemistries is presented. At first, cycloaddition/click chemistries already used for modifying nucleic acids are summarized, ranging from the well-established copper(I)-catalyzed alkyne-azide cycloaddition reaction to copper free methods, such as the strain-promoted azide-alkyne cycloaddition, tetrazole-based photoclick chemistry and the inverse electron demand Diels-Alder cycloaddition reaction between strained alkenes and tetrazine derivatives. The subsequent sections contain selected applications of nucleic acid functionalization via click chemistry; in particular, site-specific enzymatic labeling in vitro, either via DNA and RNA recognizing enzymes or by introducing unnatural base pairs modified for click reactions. Further sections report recent progress in metabolic labeling and fluorescent detection of DNA and RNA synthesis in vivo, click nucleic acid ligation, click chemistry in nanostructure assembly and click-SELEX as a novel method for the selection of aptamers. PMID:27572987

  10. Phytic acid in green leaves.

    PubMed

    Hadi Alkarawi, H; Zotz, G

    2014-07-01

    Phytic acid or phytate, the free-acid form of myo-inositolhexakiphosphate, is abundant in many seeds and fruits, where it represents the major storage form of phosphorus. Although also known from other plant tissues, available reports on the occurrence of phytic acid, e.g. in leaves, have never been compiled, nor have they been critically reviewed. We found 45 published studies with information on phytic acid content in leaves. Phytic acid was almost always detected when studies specifically tried to detect it, and accounted for up to 98% of total P. However, we argue that such extreme values, which rival findings from storage organs, are dubious and probably result from measurement errors. Excluding these high values from further quantitative analysis, foliar phytic acid-P averaged 2.3 mg·g(-1) , and represented, on average, 7.6% of total P. Remarkably, the ratio of phytic acid-P to total P did not increase with total P, we even detected a negative correlation of the two variables within one species, Manihot esculenta. This enigmatic finding warrants further attention. PMID:24341824

  11. Diabetes and Alpha Lipoic Acid

    PubMed Central

    Golbidi, Saeid; Badran, Mohammad; Laher, Ismail

    2011-01-01

    Diabetes mellitus is a multi-faceted metabolic disorder where there is increased oxidative stress that contributes to the pathogenesis of this debilitating disease. This has prompted several investigations into the use of antioxidants as a complementary therapeutic approach. Alpha lipoic acid, a naturally occurring dithiol compound which plays an essential role in mitochondrial bioenergetic reactions, has gained considerable attention as an antioxidant for use in managing diabetic complications. Lipoic acid quenches reactive oxygen species, chelates metal ions, and reduces the oxidized forms of other antioxidants such as vitamin C, vitamin E, and glutathione. It also boosts antioxidant defense system through Nrf-2-mediated antioxidant gene expression and by modulation of peroxisome proliferator activated receptors-regulated genes. ALA inhibits nuclear factor kappa B and activates AMPK in skeletal muscles, which in turn have a plethora of metabolic consequences. These diverse actions suggest that lipoic acid acts by multiple mechanisms, many of which have only been uncovered recently. In this review we briefly summarize the known biochemical properties of lipoic acid and then discussed the oxidative mechanisms implicated in diabetic complications and the mechanisms by which lipoic acid may ameliorate these reactions. The findings of some of the clinical trials in which lipoic acid administration has been tested in diabetic patients during the last 10 years are summarized. It appears that the clearest benefit of lipoic acid supplementation is in patients with diabetic neuropathy. PMID:22125537

  12. Terahertz spectrum of gallic acid

    NASA Astrophysics Data System (ADS)

    Wu, Meng; Zhao, Guozhong; Wang, Haiyan; Liang, Chengshen

    2009-11-01

    Gallic acid is natural polyphenol compound found in many green plants. More and more experiments have demonstrated that the gallic acid has comprehensive applications. In the field of medicine, the gallic acid plays an important role in antianaphylaxis, antineoplastic, antimycotic, anti-inflammatory, antivirotic, antiasthmatic and inhibiting the degradation of insulin. It also has a lot of applications in chemical industry, food industry and light industry. So it is important to study the terahertz time-domain spectroscopy of gallic acid. Terahertz time-domain spectroscopy (THz-TDS) is a new coherent spectral technology based on the femtosecond laser. In this work, the spectral characteristics of gallic acid in the range of 0.4 THz to 2.6 THz have been measured by THz-TDS. We obtained its absorption and refraction spectra at room temperature. The vibration absorption spectrum of the single molecule between 0.4 THz and 2.6 THz is simulated based on the Density Functional Theory (DFT). It is found that the gallic acid has the spectral response to THz wave in this frequency range. The results show the abnormal dispersion at 1.51 THz and 2.05 THz. These results can be used in the qualitative analysis of gallic acid and the medicine and food inspection.

  13. Pyroligneous acid-the smoky acidic liquid from plant biomass.

    PubMed

    Mathew, Sindhu; Zakaria, Zainul Akmar

    2015-01-01

    Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food. PMID:25467926

  14. Drilling fluids containing amps, acrylic acid, itaconic acid polymer

    SciTech Connect

    Bardoliwalla, D.F.

    1987-10-13

    This patent describes an aqueous drilling fluid having present in an amount sufficient to reduce fluid loss of the drilling fluid, at least one polymer of (1) from about 5% to about 50% by weight of 2-acrylamido-2-methylpropane sulfonic acid and (2) from about 95% to about 50% by weight of a second component, there being from 100% to about 80% by weight of acrylic acid and from 0% by weight to about 20% by weight of itaconic acid in the second component. The polymer has a weight average molecular weight of between about 50,000 to about 1,000,000 being in its free acid or partially or completely neutralized form and being at least water dispersible. A method is described of drilling a well into a subterranean formation in which an aqueous drilling fluid is circulated into the well. The step of circulating the drilling fluid contains in an amount sufficient to reduce fluid loss of the drilling fluid, at least one polymer of (1) from about 5% to about 50% by weight of 2-acrylamido-2-methylpropane sulfonic acid and (2) from about 95% to about 50% by weight of a second component. There is from 100% to about 80% by weight of acrylic acid and from 0% by weight to about 20% by weight of itaconic acid in the second component. The polymer has weight average molecular weight of between about 50,000 to about 1,000,000 in its free acid or partially or completely neutralized form and is at least water dispersible.

  15. PRODUCTION OF TRIFLUOROACETIC ACID COMPOUNDS

    DOEpatents

    Haworth, W.N.; Stacey, M.

    1949-08-30

    A process is described for the preparation of trifluoroacetic acid. Acetone vapor diluted wlth nitrogen and fluorine also diluted with nltrogen are fed separately at a temperature of about 210 deg C into a reaction vessel containing a catalyst mass selected from-the group consisting of silver and gold. The temperature in the reaction vessel is maintained in the range of 200 deg to 250 deg C. The reaction product, trifluoroacetyl fluoride, is absorbed in aqueous alkali solution. Trifluoroacetic acid is recovered from the solution by acidification wlth an acid such as sulfuric followed by steam distillation.

  16. Chemiluminescent measurement of atmospheric acid

    NASA Technical Reports Server (NTRS)

    Stedman, D. H.; Kok, G. L.

    1974-01-01

    The design and construction of a gas phase acid sensitive analyzer are reported. These studies showed that the chemical system was a practical analytical method. A complete instrument was developed and prepared for field testing. A Titan 3-C rocket was scheduled for launching on February 11, 1974. Through preparations made by NASA Langley the instrument was set up to monitor the acid concentration in the rocket exhaust. Due to adverse wind conditions no acid was detected. This entire trip is described in detail.

  17. PHARMACOLOGICAL ACTIVITIES OF PROTOCATECHUIC ACID.

    PubMed

    Khan, Abida Kalsoom; Rashid, Rehana; Fatima, Nighat; Mahmood, Sadaf; Mir, Sadullah; Khan, Sara; Jabeen, Nyla; Murtaza, Ghulam

    2015-01-01

    Protocatechuic acid (3,4-dihydroxybenzoic acid, PCA) is a simple phenolic acid. It is found in a large variety of edible plants and possesses various pharmacological activities. This article aims to review the modern trends in phytochemical isolation and extraction of PCA from plants and other natural resources. Moreover, this article also encompasses pharmacological and biological activities of PCA. It is well known to have anti-inflammatory, antioxidant, anti-hyperglycemia, antibacterial, anticancer, anti-ageing, anti-athro- genic, anti-tumoral, anti-asthma, antiulcer, antispasmodic and neurological properties. PMID:26647619

  18. Can crops tolerate acid rain

    SciTech Connect

    Kaplan, J.K.

    1989-11-01

    This brief article describes work by scientists at the ARS Air Quality-Plant Growth and Development Laboratory in Raleigh, North Carolina, that indicates little damage to crops as a result of acid rain. In studies with simulated acid rain and 216 exposed varieties of 18 crops, there were no significant injuries nor was there reduced growth in most species. Results of chronic and acute exposures were correlated in sensitive tomato and soybean plants and in tolerant winter wheat and lettuce plants. These results suggest that 1-hour exposures could be used in the future to screen varieties for sensitivity to acid rain.

  19. Amino Acids from a Comet

    NASA Technical Reports Server (NTRS)

    Cook, Jamie Elisla

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary- vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a coetary amino acid.

  20. Be an acid rain detective

    SciTech Connect

    Atwill, L.

    1982-07-01

    Acid rain is discussed in a question and answer format. The article is aimed at educating sport fishermen on the subject, and also to encourage them to write their congressmen, senators, and the President about the acid rain problem. The article also announces the availability of an acid rain test kit available through the magazine, ''Sports Afield.'' The kit consists of pH-test paper that turns different shades of pink and blue according to the pH of the water tested. The color of the test paper is then compared to a color chart furnished in the kit and an approximate pH can be determined.

  1. Abscission: Role of Abscisic Acid

    PubMed Central

    Cracker, L. E.; Abeles, F. B.

    1969-01-01

    The effect of abscisic acid on cotton (Gossypium hirsutum L. cv. Acala 4-42) and bean (Phaseolus vulgaris L. cv. Red Kidney) explants was 2-fold. It increased ethylene production from the explants, which was found to account for some of its ability to accelerate abscission. Absci is acid also increased the activity of cellulase. Increased synthesis of cellulase was not du to an increase in aging of the explants but rather was an effect of abscisic acid on the processes that lead to cellulase synthesis or activity. PMID:16657181

  2. 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 ...

  3. Genetics Home Reference: sialic acid storage disease

    MedlinePlus

    ... Home Health Conditions sialic acid storage disease sialic acid storage disease Enable Javascript to view the expand/ ... Download PDF Open All Close All Description Sialic acid storage disease is an inherited disorder that primarily ...

  4. 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 ...

  5. Molar extinction coefficients of some fatty acids

    NASA Astrophysics Data System (ADS)

    Sandhu, G. K.; Singh, Kulwant; Lark, B. S.; Gerward, L.

    2002-10-01

    The attenuation of gamma rays in some fatty acids, viz. formic acid (CH 2O 2), acetic acid (C 2H 4O 2), propionic acid (C 3H 6O 2), butyric acid (C 4H 8O 2), n-hexanoic acid (C 6H 12O 2), n-caprylic acid (C 8H 16O 2), lauric acid (C 12H 24O 2), myristic acid (C 14H 28O 2), palmitic acid (C 16H 32O 2), oleic acid (C 18H 34O 2) and stearic acid (C 18H 36O 2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement between experiment and theory.

  6. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1995-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  7. Microbial production of lactic acid.

    PubMed

    Eiteman, Mark A; Ramalingam, Subramanian

    2015-05-01

    Lactic acid is an important commodity chemical having a wide range of applications. Microbial production effectively competes with chemical synthesis methods because biochemical synthesis permits the generation of either one of the two enantiomers with high optical purity at high yield and titer, a result which is particularly beneficial for the production of poly(lactic acid) polymers having specific properties. The commercial viability of microbial lactic acid production relies on utilization of inexpensive carbon substrates derived from agricultural or waste resources. Therefore, optimal lactic acid formation requires an understanding and engineering of both the competing pathways involved in carbohydrate metabolism, as well as pathways leading to potential by-products which both affect product yield. Recent research leverages those biochemical pathways, while researchers also continue to seek strains with improved tolerance and ability to perform under desirable industrial conditions, for example, of pH and temperature. PMID:25604523

  8. Low acid producing solid propellants

    NASA Technical Reports Server (NTRS)

    Bennett, Robert R.

    1995-01-01

    The potential environmental effects of the exhaust products of conventional rocket propellants have been assessed by various groups. Areas of concern have included stratospheric ozone, acid rain, toxicity, air quality and global warming. Some of the studies which have been performed on this subject have concluded that while the impacts of rocket use are extremely small, there are propellant development options which have the potential to reduce those impacts even further. This paper discusses the various solid propellant options which have been proposed as being more environmentally benign than current systems by reducing HCI emissions. These options include acid neutralized, acid scavenged, and nonchlorine propellants. An assessment of the acid reducing potential and the viability of each of these options is made, based on current information. Such an assessment is needed in order to judge whether the potential improvements justify the expenditures of developing the new propellant systems.

  9. Abiotic synthesis of fatty acids

    NASA Technical Reports Server (NTRS)

    Leach, W. W.; Nooner, D. W.; Oro, J.

    1978-01-01

    The formation of fatty acids by Fischer-Tropsch-type synthesis was investigated with ferric oxide, ammonium carbonate, potassium carbonate, powdered Pueblito de Allende carbonaceous chondrite, and filings from the Canyon Diablo meteorite used as catalysts. Products were separated and identified by gas chromatography and mass spectrometry. Iron oxide, Pueblito de Allende chondrite, and Canyon Diablo filings in an oxidized catalyst form yielded no fatty acids. Canyon Diablo filings heated overnight at 500 C while undergoing slow purging by deuterium produced fatty acids only when potassium carbonate was admixed; potassium carbonate alone also produced these compounds. The active catalytic combinations gave relatively high yields of aliphatic and aromatic hydrocarbons; substantial amounts of n-alkenes were almost invariably observed when fatty acids were produced; the latter were in the range C6 to C18, with maximum yield in C9 or 10.

  10. Bile acid sequestrants for cholesterol

    MedlinePlus

    ... ency/patientinstructions/000787.htm Bile acid sequestrants for cholesterol To use the sharing features on this page, ... are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can stick ...

  11. Biopreservation by lactic acid bacteria.

    PubMed

    Stiles, M E

    1996-10-01

    Biopreservation refers to extended storage life and enhanced safety of foods using the natural microflora and (or) their antibacterial products. Lactic acid bacteria have a major potential for use in biopreservation because they are safe to consume and during storage they naturally dominate the microflora of many foods. In milk, brined vegetables, many cereal products and meats with added carbohydrate, the growth of lactic acid bacteria produces a new food product. In raw meats and fish that are chill stored under vacuum or in an environment with elevated carbon dioxide concentration, the lactic acid bacteria become the dominant population and preserve the meat with a "hidden' fermentation. The same applies to processed meats provided that the lactic acid bacteria survive the heat treatment or they are inoculated onto the product after heat treatment. This paper reviews the current status and potential for controlled biopreservation of foods. PMID:8879414

  12. Antibiofilm Properties of Acetic Acid

    PubMed Central

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup; Nielsen, Anne K.; Johansen, Helle Krogh; Homøe, Preben; Høiby, Niels; Givskov, Michael; Kirketerp-Møller, Klaus

    2015-01-01

    Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms. PMID:26155378

  13. Biotechnological production of citric acid

    PubMed Central

    Max, Belén; Salgado, José Manuel; Rodríguez, Noelia; Cortés, Sandra; Converti, Attilio; Domínguez, José Manuel

    2010-01-01

    This work provides a review about the biotechnological production of citric acid starting from the physicochemical properties and industrial applications, mainly in the food and pharmaceutical sectors. Several factors affecting citric acid fermentation are discussed, including carbon source, nitrogen and phosphate limitations, pH of culture medium, aeration, trace elements and morphology of the fungus. Special attention is paid to the fundamentals of biochemistry and accumulation of citric acid. Technologies employed at industrial scale such as surface or submerged cultures, mainly employing Aspergillus niger, and processes carried out with Yarrowia lipolytica, as well as the technology for recovering the product are also described. Finally, this review summarizes the use of orange peels and other by-products as feedstocks for the bioproduction of citric acid. PMID:24031566

  14. Simulated acid rain on crops

    SciTech Connect

    Plocher, M.D.; Perrigan, S.C.; Hevel, R.J.; Cooper, R.M.; Moss, D.N.

    1985-10-01

    In 1981, simulated H/sub 2/SO/sub 4/ acid rain was applied to alfalfa and tall fescue and a 2:1 ratio of H/sub 2/SO/sub 4/:HNO/sub 3/ acid rain was applied to alfalfa, tall fescue, barley, wheat, potato, tomato, radish, and corn crops growing in the open field at Corvallis, Oregon. Careful attention was given to effects of the acid rain on the appearance of the foliage, and the effects on yield were measured. Because the effect of pH 4.0 rain on corn yield was the only significant effect noted in the 1981 studies, in 1982, more-extensive studies of the effect of simulated H/sub 2/SO/sub 4//HNO/sub 3/ rain on corn were conducted. No significant effects of acid rain were found on foliage appearance, or on yield of grain or stover in the 1982 studies.

  15. [Treatment of hydrofluoric acid burns].

    PubMed

    Thiele, B; Winter, U J; Mahrle, G; Steigleder, G K

    1986-01-31

    A chemical-plant worker sustained hydrofluoric acid burns during cleaning procedures. Intra-arterial perfusion and intralesional injections of calcium gluconate solution prevented progression of the burns into deeper tissue layers. PMID:3943470

  16. Making cents of acid recovery

    SciTech Connect

    Ondrey, G.; Shanley, A.

    1993-04-01

    Acid recovery may be expensive, but rising transportation and landfill costs may soon make it the only alternative. Traditionally, acids used in processes from titanium dioxide production to gasoline alkylation and metal pickling were neutralized and discharged into waterways or injected into deep wells. Today, however, discharge permits are being phased out in many countries, and deep well injection is coming under closer scrutiny. An even cheaper option was selling spent acid to fertilizer producers, who used it to dissolve phosphate ores. Health concerns, a depressed fertilizer market and tightening disposal regulations for gypsum byproduct have dried up this option. The paper discusses the processes and costs involved in spent acid regeneration, gypsum-free gas treatments, and problems with explosive contaminants.

  17. EXPOSURE MODELING OF ACID AEROSOLS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) is conducting an intensive characterization and human exposure monitoring program of acid species and related air pollutants in an urban environment. he EPA's Atmospheric Research and Exposure Assessment Laboratory (AREAL) in coopera...

  18. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1995-09-12

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  19. Glucaric acids from Leonurus japonicus.

    PubMed

    Jiang, Jianshuang; Li, Yixiu; Feng, Ziming; Yang, Yanan; Zhang, Peicheng

    2015-12-01

    Three new glucaric acids, namely 2-feruloyl-4-syringoyl or 5-feruloyl-3-syringoyl glucaric acid (1), 2-syringoyl-4-feruloyl or 5-syringoyl-3-feruloyl glucaric acid (2), and 3-feruloyl-4-syringoyl or 4-feruloyl-3-syringoyl glucaric acid (3), were isolated from Leonurus japonicus Houtt. Their structures were elucidated by detailed spectroscopic means including UV, IR, HR-ESI-MS, 1D and 2D NMR data spectra. The bioactive assays of compounds 1-3 against hepatoprotection activity were determined. The result suggested that compound 2 exhibited a moderate hepatoprotection activity and the cell survival rate was 74% (10(-5)mol/L), using bicyclol (survival rate: 66%, 10(-5)mol/L) as a positive control. Furthermore, compounds 1-3 were evaluated cytotoxic activities in vitro using HCT-8, Bel-7402, BGC-823, A-549, and A2780 model and the results exhibited no obvious cytotoxicity activity. PMID:26526024

  20. Acid diffusion through polymer films

    NASA Astrophysics Data System (ADS)

    Zhang, P. Linda; Eckert, Andrew R.; Willson, C. Grant; Webber, Stephen E.; Byers, Jeffrey D.

    1997-07-01

    In order to perform 0.2 micrometer processes, one needs to study the diffusion of photoacid generators within the photoresist system, since diffusion during post exposure bake time has an influence on the critical dimension (CD). We have developed a new method to study the diffusion of photoacid generators within a polymer film. This new method is based on monitoring the change of the fluorescence intensity of a pH- sensitive fluorescent dye caused by the reaction with photoacid. A simplified version of this experiment has been conducted by introducing acid vapor to quench the fluorescence intensity of this pH sensor. A thin polymer film is spin cast onto the sensor to create a barrier to the acid diffusion process. During the acid diffusion process, the fluorescence intensity of this pH sensor is measured in situ, using excitation and emission wavelengths at 466 nm and 516 nm, respectively. Fluoresceinamine, the pH sensitive fluorescent dye, is covalently bonded onto the treated quartz substrate to form a single dye layer. Poly(hydroxystyrene) (Mn equals 13k, Tg equals 180 degrees Celsius) in PGMEA (5% - 18% by weight) is spin cast onto this quartz substrate to form films with varying thickness. The soft bake time is 60 seconds at 90 degrees Celsius and a typical film has a thickness of 1.4 micrometers. Trifluoroacetic acid is introduced into a small chamber while the fluorescence from this quartz window is observed. Our study focuses on finding the diffusion constant of the vaporized acid (trifluoroacetic acid) in the poly(hydroxystyrene) polymer film. By applying the Fick's second law, (It - Io)/(I(infinity ) - Io) equals erfc [L/(Dt)1/2] is obtained. The change of fluorescence intensity with respect to the diffusion time is monitored. The above equation is used for the data analysis, where L represents the film thickness and t represents the average time for the acid to diffuse through the film. The diffusion constant is calculated to be at the order of 10