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Sample records for alkaline peroxide ap

  1. Titanium corrosion in alkaline hydrogen peroxide environments

    NASA Astrophysics Data System (ADS)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  2. Alkaline peroxide pulping of oil palm empty fruit bunch by variation of chemical strength

    NASA Astrophysics Data System (ADS)

    Dermawan, Yunita Megasari; Ghazali, Arniza; Daud, Wan Rosli Wan; Lazin, Mohd Azli Khairil Mat

    2012-09-01

    Papers produced from oil palm empty fruit bunches (EFB) via Alkaline Peroxide Pulping (APP) was preceded by three main steps; dewaxing of EFB, alkaline peroxide (AP) impregnation into EFB and refining of biomass to generate pulp. The experiment was carried by varying chemical level and number of impregnation stages. For 2:2.5% AP level, two-stage impregnation improved hand sheets tear index by 45%, 164% boost in tensile index, 26% enhancement in zero span index and more than 5% in burst index. By applying 8:10% AP level, significant improvements were gained at the third and fourth stages of AP impregnation. Although there was no significant change in hand sheet strength with multiple impregnation for 4:5% AP level, improvement in brightness of hand sheets was apparent, analogous to the effect of increasing AP level. The found paper properties development show that alkaline peroxide pulping of EFB could be adapted to various targeted properties by adjustment of AP level and impregnation stages.

  3. Alkaline hydrogen peroxide pretreatment of softwood: hemicellulose degradation pathways.

    PubMed

    Alvarez-Vasco, Carlos; Zhang, Xiao

    2013-12-01

    This study investigated softwood hemicelluloses degradation pathways during alkaline hydrogen peroxide (AHP) pretreatment of Douglas fir. It was found that glucomannan is much more susceptible to alkaline pretreatment than xylan. Organic acids, including lactic, succinic, glycolic and formic acid are the predominant products from glucomannan degradation. At low treatment temperature (90°C), a small amount of formic acid is produced from glucomannan, whereas glucomannan degradation to lactic acid and succinic acid becomes the main reactions at 140°C and 180°C. The addition of H2O2 during alkaline pretreatment of D. fir led to a significant removal of lignin, which subsequently facilitated glucomannan solubilization. However, H2O2 has little direct effect on the glucomannan degradation reaction. The main degradation pathways involved in glucomannan conversion to organics acids are elucidated. The results from this study demonstrate the potential to optimize pretreatment conditions to maximize the value of biomass hemicellulose. PMID:24185034

  4. The electrochemistry of SIMFUEL in dilute alkaline hydrogen peroxide solutions

    NASA Astrophysics Data System (ADS)

    Goldik, Jon

    The work described in this thesis is a study of the electrochemistry of SIMFUEL (SIMulated nuclear FUEL) in dilute, alkaline hydrogen peroxide solutions. In the first set of experiments, the reaction of H2O 2 on SIMFUEL electrodes was studied electrochemically and under open circuit conditions in 0.1 mol L-1 NaCl solutions at pH 9.8. The composition of the oxidized UO2 surface was determined by X-ray photoelectron spectroscopy. Hydrogen peroxide reduction was found to be catalyzed by the formation of a mixed UIV/UV (UO 2+x) surface layer, but to be blocked by the accumulation of UVI species (UO3· yH2O or adsorbed (UO2)2+) on the electrode surface. The formation of this UVI layer blocks both H2O2 reduction and oxidation, thereby inhibiting the potentially rapid H2O2 decomposition reaction to H2O and O2. Decomposition is found to proceed at a rate controlled by the desorption of the adsorbed (UO2)2+ or reduction of adsorbed O2 species. Reduction of (O2) ads is coupled to the slow oxidative dissolution of UO2 and formation of a corrosion product deposit of UO3· yH2O. In the second series of experiments, the electrochemical reduction of hydrogen peroxide on SIMFUEL was studied using the steady-state polarization technique. Kinetic parameters for the reaction, such as Tafel slopes and reaction orders, were determined. The results were interpreted in terms of a chemical-electrochemical mechanism involving UIV/UV donor-acceptor reduction sites. The large values of the Tafel slopes and the fractional reaction orders with respect to H2O2 can be understood in terms of the potential-dependent surface coverage of active sites, similar to that observed in the reduction of hydrogen peroxide on oxidized copper surfaces. The effects of pH over the range 10-13 were also investigated. The H2O 2 reduction currents were nearly independent of pH in the range 10-11, but were slowed at more alkaline values. The change in pH dependence appears to be related to the acid-base properties

  5. Ozonation and alkaline-peroxide pretreatment of wheat straw for Cryptococcus curvatus fermentation

    NASA Technical Reports Server (NTRS)

    Greenwalt, C. J.; Hunter, J. B.; Lin, S.; McKenzie, S.; Denvir, A.

    2000-01-01

    Crop residues in an Advanced Life Support System (ALS) contain many valuable components that could be recovered and used. Wheat is 60% inedible, with approximately 90% of the total sugars in the residue cellulose and hemicellulose. To release these sugars requires pretreatment followed by enzymatic hydrolysis. Cryptococcus curvatus, an oleaginous yeast, uses the sugars in cellulose and hemicellulose for growth and production of storage triglycerides. In this investigation, alkaline-peroxide and ozonation pretreatment methods were compared for their efficiency to release glucose and xylose to be used in the cultivation of C. curvatus. Leaching the biomass with water at 65 degrees C for 4 h prior to pretreatment facilitated saccharification. Alkaline-peroxide and ozone pretreatment were almost 100% and 80% saccharification efficient, respectively. The sugars derived from the hydrolysis of alkaline-peroxide-treated wheat straw supported the growth of C. curvatus and the production of edible single-cell oil.

  6. Alkaline peroxide pretreatment of corn stover for enzymatic saccharification and ethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alkaline hydrogen peroxide (AHP) pretreatment and enzymatic saccharification were evaluated for conversion of corn stover cellulose and hemicellulose to fermentable sugars. Corn stover used in this study contained 37.0±0.2% cellulose, 26.8±0.2% hemicellulose and 18.0±0.1% lignin on dry basis. Unde...

  7. Pretreatment of cane bagasse with alkaline hydrogen peroxide for enzymatic hydrolysis of cellulose and ethanol fermentation

    SciTech Connect

    Azzam, A.M. )

    1989-01-01

    Pretreatment of the agrocellulosic waste, cane bagasse with alkaline hydrogen peroxide greatly enhances its susceptibility to enzymatic cellulolysis and thus the ethanol production from it. Various process conditions have been studied to optimize the enzymate effectiveness. These conditions include the contact time, the hydrogen peroxide concentration and the pretreatment temperature. Results obtained show, that about 50% of lignin and most of hemicellulose content of can bagasse was solubilized, by 2% alkaline hydrogen peroxide at 30{sup 0}C within 8 h. The cellulose content was consequently increased from 42% in the original cane bagasse to 75% in the oxidized pulp. Saccharification of this pulp residue with cellulase from Trichorderma viride at 45{sup 0}C for 24 h, yielded glucose with 95% efficiency. The efficiency of ethanol production from the insoluble fraction with S. cervisiae was 90% compared to about 50% for untreated cane bagasse.

  8. The corrosion of titanium in alkaline peroxide bleach liquors

    SciTech Connect

    Wyllie, W.E. II; Brown, B.E.; Duquette, D.J.

    1994-12-31

    An experimental program to determine the effects of hydrogen peroxide (H{sub 2}O{sub 2}) and of potential corrosion inhibitors on the corrosion behavior of titanium has been developed. Corrosion rates less than 0.25 mm/y were observed in laboratory bleach liquor at pH 12 to which 5 g/l of H{sub 2}O{sub 2} were added. At pH 13, with 10 g/l H{sub 2}O{sub 2}, the corrosion rates were unacceptably high in both sodium hydroxide (NaOH) and laboratory bleach liquor solutions (>8.38 mm/y). The preliminary results of inhibitor studies indicated that the addition of 3.7 g/l sodium silicate or 0.01 g/l calcium nitrate (Ca(NO{sub 3}){sub 2}) effectively inhibited the corrosion of titanium exposed to 5 g/l of H{sub 2}O{sub 2} in NaOH solutions of pH 12. It was also found that in simulated paper mill chemistries, i.e., basic solutions containing 3.7 g/l sodium silicate and 0.6 g/l EDTA (ethylenediaminetetraacetic acid), corrosion rates increased markedly with the addition of 5 g/l H{sub 2}O{sub 2}. However, subsequent additions of peroxide resulted in corrosion rates which were even lower than those found in NaOH. This is believed to be due to the formation of a black scale on the surface of the sample. The addition of magnesium sulfate (MgSO{sub 4}) in the 0.1--0.5 g/l range also was shown to inhibit corrosion in the NaOH solution, but only after prior exposure to H{sub 2}O{sub 2}.

  9. Alkaline peroxide treatment induces acquired unruly hair by apparently affecting distinct macrofibrils.

    PubMed

    Nawa, Teppei; Kawaguchi, Aiko; Kitano, Hiroki; Yamamoto, Toshihiko; Fujinami, So; Asao, Naoki; Nakajima, Ken

    2013-01-01

    Individual hairs can be inherently curly; however, bleach treatment can cause damaged hairs to acquire a curl, a phenomenon we term acquired unintentional unruly hair. Because there have been no reports concerning acquired unintentional unruly hair, the influence of bleach treatment with alkaline peroxide that produce this phenomenon was investigated. First, it was validated that the radius of curvature in many curly hairs is reduced upon bleach treatment. Next, the influence of bleach treatment on the mechanical properties of inner components was studied by the force curve method using atomic force microscopy. This measurement revealed four types of macrofibrils-on the orthocortex- or the paracortex-like structure, and on the concave or the convex side-have different mechanical properties. Macrofibrils on the orthocortex-like structure on the convex side were especially influenced by alkaline peroxide treatment, and may be particularly important to acquired unintentional unruly hair. PMID:23931089

  10. Effect of Lignin Removal by Alkaline Peroxide Pretreatment on the Susceptibility of Corn Stover to Purified Cellulolytic and Xylanolytic Enzymes

    SciTech Connect

    Selig, M. J.; Vinzant, T. B.; Himmel, M. E.; Decker, S. R.

    2009-01-01

    Pretreatment of corn stover with alkaline peroxide (AP) at pH 11.5 resulted in reduction of lignin content in the residual solids as a function of increasing batch temperature. Scanning electron microscopy of these materials revealed notably more textured surfaces on the plant cell walls as a result of the delignifying pretreatment. As expected, digestion of the delignified samples with commercial cellulase preparations showed an inverse relationship between the content of lignin present in the residual solids after pretreatment and the extent of both glucan and xylan conversion achievable. Digestions with purified enzymes revealed that decreased lignin content in the pretreated solids did not significantly impact the extent of glucan conversion achievable by cellulases alone. Not until purified xylanolytic activities were included with the cellulases were significant improvements in glucan conversion realized. In addition, an inverse relationship was observed between lignin content after pretreatment and the extent of xylan conversion achievable in a 24-h period with the xylanolytic enzymes in the absence of the cellulases. This observation, coupled with the direct relationship between enzymatic xylan and glucan conversion observed in a number of cases, suggests that the presence of lignins may not directly occlude cellulose present in lignocelluloses but rather impact cellulase action indirectly by its association with xylan.

  11. Characterisation of mechanical pulp fines from alkaline peroxide pulping of EFB

    NASA Astrophysics Data System (ADS)

    Kamaludin, Nurul Hasanah; Ghazali, Arniza; Daud, Wan Rosli Wan

    2012-09-01

    EFB (empty fruit bunch) was subjected to alkaline peroxide pulping for generation of fibrous mass as raw material for the making of pulp-based products. During refining, co-produced fines were collected by fractionation on square-mesh screens of 200-, 250-, 300- and 400- mesh sizes, placed at the refining discharge by order of increasing mesh. Each set of the produced paper was incorporated with 12% fines for microscopic analysis. It appears that sheared vessel elements and fibrils were predominant and they make up the mass rendering collapsibility of cell wall for good product formation. The study acknowledged the form of fines functioning as natural filler in pulp network and worthy of utilization for reduction of total suspended solid.

  12. Catalysis with Cu(II) (bpy) improves alkaline hydrogen peroxide pretreatment.

    PubMed

    Li, Zhenglun; Chen, Charles H; Liu, Tongjun; Mathrubootham, Vaidyanathan; Hegg, Eric L; Hodge, David B

    2013-04-01

    Copper(II) 2,2'-bipyridine (Cu(II) (bpy))-catalyzed alkaline hydrogen peroxide (AHP) pretreatment was performed on three biomass feedstocks including alkali pre-extracted switchgrass, silver birch, and a hybrid poplar cultivar. This catalytic approach was found to improve the subsequent enzymatic hydrolysis of plant cell wall polysaccharides to monosaccharides for all biomass types at alkaline pH relative to uncatalyzed pretreatment. The hybrid poplar exhibited the most significant improvement in enzymatic hydrolysis with monomeric sugar release and conversions more than doubling from 30% to 61% glucan conversion, while lignin solubilization was increased from 36.6% to 50.2% and hemicellulose solubilization was increased from 14.9% to 32.7%. It was found that Cu(II) (bpy)-catalyzed AHP pretreatment of cellulose resulted in significantly more depolymerization than uncatalyzed AHP pretreatment (78.4% vs. 49.4% decrease in estimated degree of polymerization) and that carboxyl content the cellulose was significantly increased as well (fivefold increase vs. twofold increase). Together, these results indicate that Cu(II) (bpy)-catalyzed AHP pretreatment represents a promising route to biomass deconstruction for bioenergy applications. PMID:23192283

  13. Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

    PubMed Central

    2012-01-01

    Background For cellulosic biofuels processes, suitable characterization of the lignin remaining within the cell wall and correlation of quantified properties of lignin to cell wall polysaccharide enzymatic deconstruction is underrepresented in the literature. This is particularly true for grasses which represent a number of promising bioenergy feedstocks where quantification of grass lignins is particularly problematic due to the high fraction of p-hydroxycinnamates. The main focus of this work is to use grasses with a diverse range of lignin properties, and applying multiple lignin characterization platforms, attempt to correlate the differences in these lignin properties to the susceptibility to alkaline hydrogen peroxide (AHP) pretreatment and subsequent enzymatic deconstruction. Results We were able to determine that the enzymatic hydrolysis of cellulose to to glucose (i.e. digestibility) of four grasses with relatively diverse lignin phenotypes could be correlated to total lignin content and the content of p-hydroxycinnamates, while S/G ratios did not appear to contribute to the enzymatic digestibility or delignification. The lignins of the brown midrib corn stovers tested were significantly more condensed than a typical commercial corn stover and a significant finding was that pretreatment with alkaline hydrogen peroxide increases the fraction of lignins involved in condensed linkages from 88–95% to ~99% for all the corn stovers tested, which is much more than has been reported in the literature for other pretreatments. This indicates significant scission of β-O-4 bonds by pretreatment and/or induction of lignin condensation reactions. The S/G ratios in grasses determined by analytical pyrolysis are significantly lower than values obtained using either thioacidolysis or 2DHSQC NMR due to presumed interference by ferulates. Conclusions It was found that grass cell wall polysaccharide hydrolysis by cellulolytic enzymes for grasses exhibiting a diversity of

  14. Effect of thermal, acid, alkaline and alkaline-peroxide pretreatments on the biochemical methane potential and kinetics of the anaerobic digestion of wheat straw and sugarcane bagasse.

    PubMed

    Bolado-Rodríguez, Silvia; Toquero, Cristina; Martín-Juárez, Judit; Travaini, Rodolfo; García-Encina, Pedro Antonio

    2016-02-01

    The effect of thermal, acid, alkaline and alkaline-peroxide pretreatments on the methane produced by the anaerobic digestion of wheat straw (WS) and sugarcane bagasse (SCB) was studied, using whole slurry and solid fraction. All the pretreatments released formic and acetic acids and phenolic compounds, while 5-hydroxymetilfurfural (HMF) and furfural were generated only by acid pretreatment. A remarkable inhibition was found in most of the whole slurry experiments, except in thermal pretreatment which improved methane production compared to the raw materials (29% for WS and 11% for SCB). The alkaline pretreatment increased biodegradability (around 30%) and methane production rate of the solid fraction of both pretreated substrates. Methane production results were fitted using first order or modified Gompertz equations, or a novel model combining both equations. The model parameters provided information about substrate availability, controlling step and inhibitory effect of compounds generated by each pretreatment. PMID:26642223

  15. The alkaline aluminium/hydrogen peroxide power source in the Hugin II unmanned underwater vehicle

    NASA Astrophysics Data System (ADS)

    Hasvold, Øistein; Johansen, Kjell Håvard; Mollestad, Ole; Forseth, Sissel; Størkersen, Nils

    In 1993, The Norwegian Defence Research Establishment (FFI) demonstrated AUV-Demo, an unmanned (untethered) underwater vehicle (UUV), powered by a magnesium/dissolved oxygen seawater battery (SWB). This technology showed that an underwater range of at least 1000 nautical miles at a speed of 4 knots was possible, but also that the maximum hotel load this battery system could support was very limited. Most applications for UUV technology need more power over a shorter period of time. Seabed mapping using a multibeam echo sounder mounted on an UUV was identified as a viable application and the Hugin project was started in 1995 in cooperation with Norwegian industry. For this application, an endurance of 36 h at 4 knots was required. Development of the UUV hull and electronics system resulted in the UUV Hugin I. It carries a Ni/Cd battery of 3 kW h, allowing up to 6 h under-water endurance. In parallel, we developed a battery based on a combination of alkaline Al/air and SWB technology, using a circulating alkaline electrolyte, aluminium anodes and maintaining the oxidant concentration in the electrolyte by continuously adding hydrogen peroxide (HP) to the electrolyte. This concept resulted in a safe battery, working at ambient pressure (balanced) and with sufficient power and energy density to allow the UUV Hugin II to make a number of successive dives, each of up to 36 h duration and with only 1 h deck time between dives for HP refill and electrolyte exchange. After 100 h, an exchange of anodes takes place. The power source consists of a four-cell Al/HP battery, a DC/DC converter delivering 600 W at 30 V, circulation and dosing pumps and a battery control unit. Hugin II is now in routine use by the Norwegian Underwater Intervention AS (NUI) which operates the UUV for high-precision seabed mapping down to a water depth of 600 m.

  16. ENZYMATIC SACCHARIFICATION AND FERMENTATION OF ALKALINE PEROXIDE PRETREATED RICE HULLS TO ETHANOL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice hulls used in this study contained 35.62 +/- 0.12% cellulose and 11.96 +/- 0.73% hemicellulose. Alkaline H2O2 pretreatment and enzymatic saccharification methods were evaluated for conversion of rice hull cellulose and hemicellulose to simple sugars. The yield of sugars from diluted alkaline ...

  17. Three-dimensional nanoporous gold-cobalt oxide electrode for high-performance electroreduction of hydrogen peroxide in alkaline medium

    NASA Astrophysics Data System (ADS)

    Li, Zhihao; He, Yanghua; Ke, Xi; Gan, Lin; Zhao, Jie; Cui, Guofeng; Wu, Gang

    2015-10-01

    Using a simple hydrothermal method combined with a post-annealing treatment, cobalt oxide (Co3O4) nanosheet arrays are grown on three-dimensional (3D) nanoporous gold (NPG) film supported on Ni foam substrates, in which NPG is fabricated by chemically dealloying electrodeposited Au-Sn alloy films. The morphology and structure of the Co3O4@NPG/Ni foam hybrids are characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical activity of the Co3O4@NPG/Ni foam electrode toward hydrogen peroxide electroreduction in alkaline medium is studied by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and chronoamperometry (CA). The results demonstrate that the Co3O4@NPG/Ni foam electrode possesses exceptionally high catalytic activity and excellent stability for the peroxide electroreduction, resulting mainly from the unique electrode architecture. The combined 3D hierarchical porous structures of NPG/Ni foam with the open and porous structures of Co3O4 nanosheet arrays facilitate the mass transport and charge transfer. Therefore, the metal oxides supported on 3D hierarchical porous NPG/Ni foam framework may hold great promise to be effective electrodes for electrocatalytic reduction of peroxide and other electrochemical reactions.

  18. Products of alkaline peroxide attack on wheat straw, oak, and keraf

    SciTech Connect

    Abbott, T.; Peterson, R.

    1985-07-01

    Wheat straw, oak, and kenaf were partially delignified by treatment with hydrogen peroxide at pH 11.0, and the water-soluble degradation products were characterized. Forty to sixty percent of the solubilized products were larger than 1000 molecular weight (MW), as determined by membrane ultrafiltration. Lignin degradation products in the low-molecular-weight fraction (is less than 1000) consisted primarily of aromatic and aliphatic carboxylic acids. 14 references.

  19. Effect of alkaline hydrogen peroxide treatment on cell wall composition and digestion kinetics of sugarcane residues and wheat straw.

    PubMed

    Amjed, M; Jung, H G; Donker, J D

    1992-09-01

    Our objective was to characterize changes in cell wall composition and digestibility of sugarcane bagasse, pith from bagasse, and wheat straw after treatment with alkaline hydrogen peroxide (AHP). The AHP treatment solution contained 1% H2O2 (wt/vol) maintained at pH 11.5 with NaOH. The H2O2 in solution amounted to 25% of the quantity of substrate treated. After treatment, residues were washed and dried. Detergent fiber composition, total fiber components (neutral sugars, uronic acids, Klason lignin, and noncore lignin phenolic acids), IVDMD, in vitro digestion kinetics of NDF, and monosaccharide digestibilities (24 and 120 h) were determined. Total fiber (TF) and NDF concentrations of all treatment residues were increased (P less than .05) over control substrates by AHP because of greater losses of cell solubles than of cell wall constituents. Hemicellulose:cellulose ratio in NDF of treatment residues was decreased (P less than .05) by AHP for all substrates, but the neutral sugar composition of TF did not agree with this preferential loss of hemicellulose components. Klason lignin, ADL, and esterified noncore lignin, especially ferulic acid, were reduced (P less than .05) by AHP, whereas etherified noncore lignin composition was unchanged. Treatment increased (P less than .05) IVDMD, extent of NDF digestion, and monosaccharide digestibilities of all crop residues. The rate of NDF digestion was increased (P less than .05) for the sugarcane residues but not for wheat straw. Alkaline hydrogen peroxide improved crop residue digestibility, probably as a result of the removal of core and noncore lignin fractions. PMID:1328129

  20. Structures and stabilities of alkaline earth metal peroxides XO2 (X=Ca, Be, Mg) studied by a genetic algorithm

    SciTech Connect

    Zhao, Xin; Nguyen, Manh Cuong; Wang, Cai-Zhuang; Ho, Kai-Ming

    2013-09-17

    The structures and stabilities of alkaline earth metal peroxides XO2 (X = Ca, Be, Mg) were studied using an adaptive genetic algorithm (GA) for global structure optimization in combination with first-principles calculations. From the adaptive GA search, we obtained an orthorhombic structure for CaO2 with 12 atoms in the unit cell, which is energetically more favorable than the previously proposed structures. Reaction energy of the decomposition CaO2 → CaO + 1/2O2 determined by density functional theory (DFT) calculation shows that this orthorhombic calcium peroxide structure is thermodynamically stable. The simulated X-ray diffraction (XRD) pattern using our predicted structure is in excellent agreement with experimental data. We also show that crystal phase BeO2 is unlikely to exist under normal conditions. MgO2 has a cubic pyrite structure, but it is not stable against decomposition: MgO2 → MgO + 1/2O2.

  1. Relation of fatty acid composition in lead-exposed mallards to fat mobilization, lipid peroxidation and alkaline phosphatase activity

    USGS Publications Warehouse

    Mateo, R.; Beyer, W.N.; Spann, J.W.; Hoffman, D.J.

    2003-01-01

    The increase of n-6 polyunsaturated fatty acids (PUFA) in animal tissues has been proposed as a mechanism of Pb poisoning through lipid peroxidation or altered eicosanoids metabolism. We have studied fatty acid (FA) composition in liver and brain of mallards (Anas platyrhynchos) feeding for three weeks on diets containing combinations of low or high levels of vitamin E (20 or 200 UI/kg) and Pb (0 or 2 g/kg). Saturated FA, n-6 PUFA and total concentrations of FA were higher in livers of Pb-exposed mallards, but not in their brains. The percentage of n-6 PUFA in liver and brain was slightly higher in Pb-exposed mallards. The increase of n-6 PUFA in liver was associated with increased triglycerides and cholesterol in plasma, thus could be in part attributed to feed refusal and fat mobilization. The hepatic ratios between adrenic acid (22:4 n-6) and arachidonic acid (20:4 n-6) or between adrenic acid and linoleic acid (18:2 n-6) were higher in Pb exposed birds, supporting the existing hypothesis of increased fatty acid elongation by Pb. Among the possible consequences of increased n-6 PUFA concentration in tissues, we found increased lipid peroxidation in liver without important histopathological changes, and decreased plasma alkaline phosphatase activity that may reflect altered bone metabolism in birds.

  2. A fuel-cell reactor for the direct synthesis of hydrogen peroxide alkaline solutions from H(2) and O(2).

    PubMed

    Yamanaka, Ichiro; Onisawa, Takeshi; Hashimoto, Toshikazu; Murayama, Toru

    2011-04-18

    The effects of the type of fuel-cell reactors (undivided or divided by cation- and anion-exchange membranes), alkaline electrolytes (LiOH, NaOH, KOH), vapor-grown carbon fiber (VGCF) cathode components (additives: none, activated carbon, Valcan XC72, Black Pearls 2000, Seast-6, and Ketjen Black), and the flow rates of anolyte (0, 1.5, 12 mL h(-1)) and catholyte (0, 12 mL h(-1)) on the formation of hydrogen peroxide were studied. A divided fuel-cell system, O(2) (g)|VGCF-XC72 cathode|2 M NaOH catholyte|cation-exchange membrane (Nafion-117)|Pt/XC72-VGCF anode|2 M NaOH anolyte at 12 mL h(-1) flow|H(2) (g), was effective for the selective formation of hydrogen peroxide, with 130 mA cm(-2) , a 2 M aqueous solution of H(2)O(2)/NaOH, and a current efficiency of 95 % at atmospheric pressure and 298 K. The current and formation rate gradually decreased over a long period of time. The cause of the slow decrease in electrocatalytic performance was revealed and the decrease was stopped by a flow of catholyte. Cyclic voltammetry studies at the VGCF-XC72 electrode indicated that fast diffusion of O(2) from the gas phase to the electrode, and quick desorption of hydrogen peroxide from the electrode to the electrolyte were essential for the efficient formation of solutions of H(2)O(2)/NaOH. PMID:21400665

  3. Removal of Fermentation Inhibitors from Alkaline Peroxide Pretreated and Enzymatically Hydrolyzed Wheat Straw: Production of Butanol from Hydrolysate Using Clostridium beijerinckii in Batch Reactors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In these studies, alkaline peroxide pretreatment of wheat straw was investigated. Pretreated wheat straw was hydrolyzed using celluloytic and xylanolytic enzymes, and the hydrolysate was used to produce butanol using Clostridium beijerinckii P260. The culture produced less than 2.59 gL**-1 acetone...

  4. Processing of LEU targets for {sup 99}Mo production: Dissolution of U{sub 3}Si{sub 2} targets by alkaline hydrogen peroxide

    SciTech Connect

    Buchholz, B.A.; Vandegrift, G.F.

    1995-09-01

    Low-enriched uranium silicide targets designed to recover fission product {sup 99}Mo were dissolved in alkaline hydrogen peroxide (H{sub 2}O{sub 2} plus NaOH) at about 90C. Sintering of matrix aluminum powder during irradiation and heat treatment retarded aluminum dissolution and prevented silicide particle dispersion. Gas evolved during dissolution is suspected to adhere to particles and block hydroxide ion contact with aluminum. Reduction of base concentrations from 5M to O.lM NaOH yielded similar silicide dissolution and peroxide destruction rates, simplifying later processing. Future work in particle dispersion enhancement, {sup 99}Mo separation, and waste disposal is also discussed.

  5. [Effect of Residual Hydrogen Peroxide on Hydrolysis Acidification of Sludge Pretreated by Microwave -H2O2-Alkaline Process].

    PubMed

    Jia, Rui-lai; Liu, Ji-bao; Wei, Yuan-song; Cai, Xing

    2015-10-01

    Previous studies have found that in the hydrolysis acidification process, sludge after microwave -H2O2-alkaline (MW-H2O2-OH, pH = 10) pretreatment had an acid production lag due to the residual hydrogen peroxide. In this study, effects of residual hydrogen peroxide after MW-H2O2-OH (pH = 10 or pH = 11) pretreatment on the sludge hydrolysis acidification were investigated through batch experiments. Our results showed that catalase had a higher catalytic efficiency than manganese dioxide for hydrogen peroxide, which could completely degraded hydrogen peroxide within 10 min. During the 8 d of hydrolysis acidification time, both SCOD concentrations and the total VFAs concentrations of four groups were firstly increased and then decreased. The optimized hydrolysis times were 0.5 d for four groups, and the optimized hydrolysis acidification times were 3 d for MW-H2O2-OH (pH = 10) group, MW-H2O2-OH (pH = 10) + catalase group and MW-H2O2-OH (pH = 11) + catalase group. The optimized hydrolysis acidification time for MW-H2O2-OH (pH = 11) group was 4 d. Residual hydrogen peroxide inhibited acid production for sludge after MW-H2O2-OH (pH = 10) pretreatment, resulting in a lag in acidification stage. Compared with MW-H2O2-OH ( pH = 10) pretreatment, MW-H2O2-OH (pH = 11 ) pretreatment released more SCOD by 19.29% and more organic matters, which resulted in the increase of total VFAs production significantly by 84.80% at 5 d of hydrolysis acidification time and MW-H2O2-OH (pH = 11) group could shorten the lag time slightly. Dosing catalase (100 mg x -L(-1)) after the MW-H2O2-OH (pH = 10 or pH = 11) pretreatment not only significantly shortened the lag time (0.5 d) in acidification stage, but also produced more total VFAs by 23.61% and 50.12% in the MW-H2O2-OH (pH = 10) + catalase group and MW-H2O2-OH (pH = 11) + catalase group, compared with MW-H2O2-OH (pH = 10) group at 3d of hydrolysis acidification time. For MW-H2O2-OH (pH = 10) group, MW-H2O2-OH (pH = 10) + catalase group and

  6. Saccharification of microalgae biomass obtained from wastewater treatment by enzymatic hydrolysis. Effect of alkaline-peroxide pretreatment.

    PubMed

    Martín Juárez, Judit; Lorenzo Hernando, Ana; Muñoz Torre, Raúl; Blanco Lanza, Saúl; Bolado Rodríguez, Silvia

    2016-10-01

    An enzymatic method for the carbohydrate hydrolysis of different microalgae biomass cultivated in domestic (DWB) and pig manure (PMWB) wastewaters, at different storage conditions (fresh, freeze-dried and reconstituted), was evaluated. The DWB provided sugars yields between 40 and 63%, although low xylose yields (< 23.5%). Approximately 2% of this biomass was converted to byproducts as succinic, acetic and formic acids. For PMWB, a high fraction of the sugars (up to 87%) was extracted, but mainly converted into acetic, butyric and formic acids, which was attributed to the bacterial action. In addition, the performance of an alkaline-peroxide pretreatment, conducted for 1h, 50°C and H2O2 concentrations from 1 to 7.5% (w/w), was essayed. The hydrolysis of pretreated microalgae supported a wide range of sugars extraction for DWB (55-90%), and 100% for PMWB. Nevertheless, a large fraction of these sugars (∼30% for DWB and 100% for PMWB) was transformed to byproducts. PMID:27372005

  7. QM/MM analysis suggests that Alkaline Phosphatase (AP) and Nucleotide pyrophosphatase/phosphodiesterase slightly tighten the transition state for phosphate diester hydrolysis relative to solution: implication for catalytic promiscuity in the AP superfamily

    PubMed Central

    Hou, Guanhua

    2011-01-01

    Several members of the Alkaline Phosphatase (AP) superfamily exhibit a high level of catalytic proficiency and promiscuity in structurally similar active sites. A thorough characterization of the nature of transition state for different substrates in these enzymes is crucial for understanding the molecular mechanisms that govern those remarkable catalytic properties. In this work, we study the hydrolysis of a phosphate diester, MpNPP−, in solution, two experimentally well-characterized variants of AP (R166S AP, R166S/E322Y AP) and wild type Nucleotide pyrophosphatase/phosphodiesterase (NPP) by QM/MM calculations in which the QM method is an approximate density functional theory previously parameterized for phosphate hydrolysis (SCC-DFTBPR). The general agreements found between these calculations and available experimental data for both solution and enzymes support the use of SCC-DFTBPR/MM for a semi-quantitative analysis of the catalytic mechanism and nature of transition state in AP and NPP. Although phosphate diesters are cognate substrates for NPP but promiscuous substrates for AP, the calculations suggest that their hydrolysis reactions catalyzed by AP and NPP feature similar synchronous transition states that are slightly tighter in nature compared to that in solution, due in part to the geometry of the bimetallic zinc motif. Therefore, this study provides the first direct computational support to the hypothesis that enzymes in the AP superfamily catalyze cognate and promiscuous substrates via similar transition states to those in solution. Our calculations do not support the finding of recent QM/MM studies by López-Canut and coworkers, who suggested that the same diester substrate goes through a much looser transition state in NPP/AP than in solution, a result likely biased by the large structural distortion of the bimetallic zinc site in their simulations. Finally, our calculations for different phosphate diester orientations and phosphorothioate diesters

  8. Harnessing Genetic Diversity in Saccharomyces cerevisiae for Fermentation of Xylose in Hydrolysates of Alkaline Hydrogen Peroxide-Pretreated Biomass

    PubMed Central

    Liu, Tongjun; Parreiras, Lucas S.; Williams, Daniel L.; Wohlbach, Dana J.; Bice, Benjamin D.; Ong, Irene M.; Breuer, Rebecca J.; Qin, Li; Busalacchi, Donald; Deshpande, Shweta; Daum, Chris; Gasch, Audrey P.

    2014-01-01

    The fermentation of lignocellulose-derived sugars, particularly xylose, into ethanol by the yeast Saccharomyces cerevisiae is known to be inhibited by compounds produced during feedstock pretreatment. We devised a strategy that combined chemical profiling of pretreated feedstocks, high-throughput phenotyping of genetically diverse S. cerevisiae strains isolated from a range of ecological niches, and directed engineering and evolution against identified inhibitors to produce strains with improved fermentation properties. We identified and quantified for the first time the major inhibitory compounds in alkaline hydrogen peroxide (AHP)-pretreated lignocellulosic hydrolysates, including Na+, acetate, and p-coumaric (pCA) and ferulic (FA) acids. By phenotyping these yeast strains for their abilities to grow in the presence of these AHP inhibitors, one heterozygous diploid strain tolerant to all four inhibitors was selected, engineered for xylose metabolism, and then allowed to evolve on xylose with increasing amounts of pCA and FA. After only 149 generations, one evolved isolate, GLBRCY87, exhibited faster xylose uptake rates in both laboratory media and AHP switchgrass hydrolysate than its ancestral GLBRCY73 strain and completely converted 115 g/liter of total sugars in undetoxified AHP hydrolysate into more than 40 g/liter ethanol. Strikingly, genome sequencing revealed that during the evolution from GLBRCY73, the GLBRCY87 strain acquired the conversion of heterozygous to homozygous alleles in chromosome VII and amplification of chromosome XIV. Our approach highlights that simultaneous selection on xylose and pCA or FA with a wild S. cerevisiae strain containing inherent tolerance to AHP pretreatment inhibitors has potential for rapid evolution of robust properties in lignocellulosic biofuel production. PMID:24212571

  9. Combined capillary electrophoresis and high performance liquid chromatography studies on the kinetics and mechanism of the hydrogen peroxide-thiocyanate reaction in a weakly alkaline solution.

    PubMed

    Hu, Ying; Song, Yanan; Horváth, Attila K; Cui, Yin; Ji, Chen; Zhao, Yuemin; Gao, Qingyu

    2014-03-01

    The hydrogen peroxide-thiocyanate reaction has been reinvestigated by means of capillary electrophoresis and high performance liquid chromatography under weakly alkaline conditions at 25.0±0.1 °C. Concentration-time series of thiocyanate, sulfate and cyanate have been followed by capillary electrophoresis as well as that of thiocyanate and hydrogen peroxide by HPLC. It has been clearly demonstrated that OxSCN(-) (where x=1, 2 and 3) cannot be accumulated in detectable amount in contrast to the results of Christy and Egeberg, hence these species can only be regarded as short-lived intermediates. It has been shown that the overall rate law is first-order with respect to both reactants, but no pH-dependence was observed within the pH range of 8.86-10.08. A simple kinetic model has been proposed to fit all the concentration-time curves simultaneously at five different pHs demonstrating the powerful combination of the experimental techniques CE and HPLC with simultaneous evaluation of kinetic curves. It is also enlightened that the quality of the buffer strongly affects the rate of the overall reaction that increases in the order of application of ammonia, phosphate, carbonate and borate, respectively at a constant ionic strength and pH. PMID:24468335

  10. Formulation of enzyme blends to maximize the hydrolysis of alkaline peroxide pretreated alfalfa hay and barley straw by rumen enzymes and commercial cellulases

    PubMed Central

    2014-01-01

    Background Efficient conversion of lignocellulosic biomass to fermentable sugars requires the synergistic action of multiple enzymes; consequently enzyme mixtures must be properly formulated for effective hydrolysis. The nature of an optimal enzyme blends depends on the type of pretreatment employed as well the characteristics of the substrate. In this study, statistical experimental design was used to develop mixtures of recombinant glycosyl hydrolases from thermophilic and anaerobic fungi that enhanced the digestion of alkaline peroxide treated alfalfa hay and barley straw by mixed rumen enzymes as well as commercial cellulases (Accelerase 1500, A1500; Accelerase XC, AXC). Results Combinations of feruloyl and acetyl xylan esterases (FAE1a; AXE16A_ASPNG), endoglucanase GH7 (EGL7A_THITE) and polygalacturonase (PGA28A_ASPNG) with rumen enzymes improved straw digestion. Inclusion of pectinase (PGA28A_ASPNG), endoxylanase (XYN11A_THITE), feruloyl esterase (FAE1a) and β-glucosidase (E-BGLUC) with A1500 or endoglucanase GH7 (EGL7A_THITE) and β-xylosidase (E-BXSRB) with AXC increased glucose release from alfalfa hay. Glucose yield from straw was improved when FAE1a and endoglucanase GH7 (EGL7A_THITE) were added to A1500, while FAE1a and AXE16A_ASPNG enhanced the activity of AXC on straw. Xylose release from alfalfa hay was augmented by supplementing A1500 with E-BGLUC, or AXC with EGL7A_THITE and XYN11A_THITE. Adding arabinofuranosidase (ABF54B_ASPNG) and esterases (AXE16A_ASPNG; AXE16B_ASPNG) to A1500, or FAE1a and AXE16A_ASPNG to AXC enhanced xylose release from barley straw, a response confirmed in a scaled up assay. Conclusion The efficacy of commercial enzyme mixtures as well as mixed enzymes from the rumen was improved through formulation with synergetic recombinant enzymes. This approach reliably identified supplemental enzymes that enhanced sugar release from alkaline pretreated alfalfa hay and barley straw. PMID:24766728

  11. Effects of alkaline hydrogen peroxide treatment on in vitro degradation of cellulosic substrates by mixed ruminal microorganisms and Bacteroides succinogenes S85.

    PubMed Central

    Lewis, S M; Montgomery, L; Garleb, K A; Berger, L L; Fahey, G C

    1988-01-01

    The effects of sodium hydroxide (NaOH) and alkaline hydrogen peroxide (AHP) treatments on wheat straw (WS) and various cellulosic substrates were determined by measuring susceptibility to degradation by mixed ruminal organisms or Bacteroides succinogenes S85. In vitro incubations were used to measure differences in fermentation resulting from each successive step in the AHP treatment process. In vitro incubations through 48 or 108 h were conducted to measure these differences. The AHP treatment of WS increased (P less than 0.05) dry matter, neutral detergent fiber, and acid detergent fiber degradation over control WS when these substrates were incubated with mixed ruminal microorganisms or B. succinogenes S85. Fermentations containing AHP-treated WS had greater (P less than 0.05) microbial purine (RNA) and volatile fatty acid concentrations by 12 h compared with those containing untreated or NaOH-treated WS. Xylose in AHP-treated WS was utilized more extensively (P less than 0.05) by 12 h compared with the xylose of untreated or NaOH-treated WS. Treatment with AHP removed 23% of the alkali-labile phenolic compounds from WS. When substrates with high levels of crystalline cellulose (raw cotton fiber, Solka floc, and Sigmacell-50) were treated with NaOH or AHP and incubated for 108 h with B. succinogenes S85, extent of acid detergent fiber degradation of cotton fiber and Sigmacell-50 was similar to that of their respective controls. Sodium hydroxide and AHP treatments were effective in increasing acid detergent fiber degradation of the Solka floc which contained, on average, 3.3 and 4.8 percentage units more acid detergent lignin and hemicellulose, respectively, than cotton fiber and Sigmacell-50.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3291761

  12. Activation of AP-1 and nuclear factor-kappaB transcription factors is involved in hydrogen peroxide-induced apoptotic cell death of oligodendrocytes.

    PubMed

    Vollgraf, U; Wegner, M; Richter-Landsberg, C

    1999-12-01

    H2O2-induced onset and execution of programmed cell death in mature rat brain oligodendrocytes in culture is accompanied by the induction and nuclear translocation of the transcription factors AP-1 and nuclear factor-kappaB (NF-kappaB), both of which have been discussed as regulators of cell death and survival. Supershift analysis of nuclear extracts indicated that the AP-1 complex consists of c-Jun, c-Fos, JunD, and possibly JunB proteins, and that the NF-kappaB complex contains p50, p65, and c-Rel proteins. The first signs of DNA fragmentation were seen already during the first hour after the treatment. DNA fragmentation could be prevented by the antioxidants pyrrolidine dithiocarbamate and vitamin E, by the nuclease inhibitor aurintricarboxylic acid, and by preincubation with the iron chelator deferoxamine (DFO). Additionally, DFO protected oligodendrocytes from H2O2-induced cytotoxic effects as assessed by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, and suppressed the formation of free radicals. DFO alone led to a slight increase and in combination with H2O2 synergistically induced DNA-binding activities of AP-1 and NF-kappaB in oligodendrocytes. Our data suggest that although low levels of H2O2 directly activate AP-1 and NF-kappaB and might contribute to signal transduction pathways promoting cell survival, the formation and action of hydroxyl radicals promote cell death mechanisms that can be attenuated by the iron chelator DFO. PMID:10582611

  13. Conversion of Saccharides into Formic Acid using Hydrogen Peroxide and a Recyclable Palladium(II) Catalyst in Aqueous Alkaline Media at Ambient Temperatures

    PubMed Central

    Zargari, N.; Kim, Y.; Jung, K. W.

    2015-01-01

    We have developed an effective method that converts a variety of mono- and disaccharides into formic acid predominantly. Our recyclable NHC-amidate palladium(II) catalyst facilitated oxidative degradation of carbohydrates without using excess oxidant. Stoichiometric amounts of hydrogen peroxide and sodium hydroxide were employed at ambient temperatures. PMID:26421000

  14. A photoelectrochemical sensor based on nickel hydroxyl-oxide modified n-silicon electrode for hydrogen peroxide detection in an alkaline solution.

    PubMed

    Li, Huaixiang; Hao, Wenlong; Hu, Jinchao; Wu, Hongyan

    2013-09-15

    A novel photoelectrochemical hydrogen peroxide (H2O2) sensor was constructed with platinum (Pt) and nickel hydroxyl-oxide (NiOOH) double layers modified n-silicon electrode (NiOOH/Pt/n-n(+)-Si). About 40nm Pt layer and about 100nm Ni layer were successively coated on the front surface of n-n(+)-Si (111) wafers by vacuum evaporating. A stable layer of NiOOH was formed through oxidation of the Ni layer on the coated silicon wafer by the electrochemical method. The surface of modified electrode was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The NiOOH/Pt/n-n(+)-Si electrode has been used for determination of H2O2 with a two-electrode cell in the absence of reference electrode by photocurrent measurement at a zero bias. The photoelectrochemical sensor showed a good linear response to H2O2 concentrations in a range from 1.0×10(-5) to 6×10(-5)M with a determination limit (S/N=3) of 2.2μM. The NiOOH/Pt/n-n(+)-Si electrode exhibited excellent reproducibility and stability. Particularly, the facile measurement requirements made this novel modified electrode promising for the development of outdoor H2O2 sensors. PMID:23584227

  15. High level extracellular production of a recombinant alkaline catalase in E. coli BL21 under ethanol stress and its application in hydrogen peroxide removal after cotton fabrics bleaching.

    PubMed

    Yu, Zhenxiao; Zheng, Hongchen; Zhao, Xingya; Li, Shufang; Xu, Jianyong; Song, Hui

    2016-08-01

    The effects of induction parameters, osmolytes and ethanol stress on the productivity of the recombinant alkaline catalase (KatA) in Escherichia coli BL21 (pET26b-KatA) were investigated. The yield of soluble KatA was significantly enhanced by 2% ethanol stress. And a certain amount of Triton X-100 supplementation could markedly improved extracellular ratio of KatA. A total soluble catalase activity of 78,762U/mL with the extracellular ratio of 92.5% was achieved by fed-batch fermentation in a 10L fermentor, which was the highest yield so far. The purified KatA showed high stability at 50°C and pH 6-10. Application of KatA for elimination of H2O2 after cotton fabrics bleaching led to less consumption of water, steam and electric power by 25%, 12% and 16.7% respectively without productivity and quality losing of cotton fabrics. Thus, the recombinant KatA is a promising candidate for industrial production and applications. PMID:27151682

  16. Acetaminophen Attenuates Lipid Peroxidation in Children Undergoing Cardiopulmonary Bypass

    PubMed Central

    Simpson, Scott A.; Zaccagni, Hayden; Bichell, David P.; Christian, Karla G.; Mettler, Bret A.; Donahue, Brian S.; Roberts, L. Jackson; Pretorius, Mias

    2014-01-01

    Objective Hemolysis, occurring during cardiopulmonary bypass (CPB), is associated with lipid peroxidation and postoperative acute kidney injury (AKI). Acetaminophen (ApAP) inhibits lipid peroxidation catalyzed by hemeproteins and in an animal model attenuated rhabdomyolysis-induced AKI. This pilot study tests the hypothesis that ApAP attenuates lipid peroxidation in children undergoing CPB. Design Single center prospective randomized double blinded study. Setting University-affiliated pediatric hospital. Patients Thirty children undergoing elective surgical correction of a congenital heart defect. Interventions Patients were randomized to ApAP (OFIRMEV® (acetaminophen) injection, Cadence Pharmaceuticals, San Diego, CA) or placebo every 6 hours for 4 doses starting before the onset of CPB. Measurement and Main Results Markers of hemolysis, lipid peroxidation (isofurans and F2-isoprostanes) and AKI were measured throughout the perioperative period. CPB was associated with a significant increase in free hemoglobin (from a pre-bypass level of 9.8±6.2 mg/dl to a peak of 201.5±42.6 mg/dl post-bypass). Plasma and urine isofuran and F2-isoprostane concentrations increased significantly during surgery. The magnitude of increase in plasma isofurans was greater than the magnitude in increase in plasma F2-isoprostanes. ApAP attenuated the increase in plasma isofurans compared to placebo (P=0.02 for effect of study drug). There was no significant effect of ApAP on plasma F2-isoprostanes or urinary makers of lipid peroxidation. ApAP did not affect postoperative creatinine, urinary neutrophil gelatinase-associated lipocalin or prevalence of AKI. Conclusion CPB in children is associated with hemolysis and lipid peroxidation. ApAP attenuated the increase in plasma isofuran concentrations. Future studies are needed to establish whether other therapies that attenuate or prevent the effects of free hemoglobin result in more effective inhibition of lipid peroxidation in patients

  17. Comparison of acid-detergent lignin, alkaline-peroxide lignin, and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibility by cattle offered bermudagrass hays of varying nutrient composition

    PubMed Central

    2014-01-01

    Background The potential for acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict fecal output (FO) and dry matter digestibility (DMD) by cattle offered bermudagrass [Cynodon dactylon (L.) Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 hay diets: low (L), medium low (ML), medium high (MH), and high (H) crude protein (CP) concentration (79, 111, 131, and 164 g CP/kg on a DM basis, respectively). Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake (DMI), DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results Forage DMI was affected by diet (P = 0.02), and DMI from MH and H was greater (P < 0.05) than from L. Apparent DMD tended (P = 0.08) to differ among diets while FO (P = 0.20) was not affected by diet treatments. Average ADL recovery (1.16) was greater (P < 0.05) than that of ADIA (1.03) and APL (1.06), but ADIA and APL did not differ (P = 0.42). Estimates of FO and DMD derived using APL and ADIA were not different (P ≥ 0.05) from total fecal collection while those using ADL differed (P < 0.05). There was no diet by marker interaction (P ≥ 0.22) for either FO or DMD. Conclusion Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improved equations to predict energy values of

  18. Electrochemical Hydrogen Peroxide Generator

    NASA Technical Reports Server (NTRS)

    Tennakoon, Charles L. K.; Singh, Waheguru; Anderson, Kelvin C.

    2010-01-01

    Two-electron reduction of oxygen to produce hydrogen peroxide is a much researched topic. Most of the work has been done in the production of hydrogen peroxide in basic media, in order to address the needs of the pulp and paper industry. However, peroxides under alkaline conditions show poor stabilities and are not useful in disinfection applications. There is a need to design electrocatalysts that are stable and provide good current and energy efficiencies to produce hydrogen peroxide under acidic conditions. The innovation focuses on the in situ generation of hydrogen peroxide using an electrochemical cell having a gas diffusion electrode as the cathode (electrode connected to the negative pole of the power supply) and a platinized titanium anode. The cathode and anode compartments are separated by a readily available cation-exchange membrane (Nafion 117). The anode compartment is fed with deionized water. Generation of oxygen is the anode reaction. Protons from the anode compartment are transferred across the cation-exchange membrane to the cathode compartment by electrostatic attraction towards the negatively charged electrode. The cathode compartment is fed with oxygen. Here, hydrogen peroxide is generated by the reduction of oxygen. Water may also be generated in the cathode. A small amount of water is also transported across the membrane along with hydrated protons transported across the membrane. Generally, each proton is hydrated with 3-5 molecules. The process is unique because hydrogen peroxide is formed as a high-purity aqueous solution. Since there are no hazardous chemicals or liquids used in the process, the disinfection product can be applied directly to water, before entering a water filtration unit to disinfect the incoming water and to prevent the build up of heterotrophic bacteria, for example, in carbon based filters. The competitive advantages of this process are: 1. No consumable chemicals are needed in the process. The only raw materials

  19. Hydrogen peroxide poisoning

    MedlinePlus

    ... peroxide is used in these products: Hydrogen peroxide Hair bleach Some contact lens cleaners Note: Household hydrogen peroxide ... it contains 97% water and 3% hydrogen peroxide. Hair bleaches are stronger. They usually have a concentration of ...

  20. Modulators of intestinal alkaline phosphatase.

    PubMed

    Bobkova, Ekaterina V; Kiffer-Moreira, Tina; Sergienko, Eduard A

    2013-01-01

    Small molecule modulators of phosphatases can lead to clinically useful drugs and serve as invaluable tools to study functional roles of various phosphatases in vivo. Here, we describe lead discovery strategies for identification of inhibitors and activators of intestinal alkaline phosphatases. To identify isozyme-selective inhibitors and activators of the human and mouse intestinal alkaline phosphatases, ultrahigh throughput chemiluminescent assays, utilizing CDP-Star as a substrate, were developed for murine intestinal alkaline phosphatase (mIAP), human intestinal alkaline phosphatase (hIAP), human placental alkaline phosphatase (PLAP), and human tissue-nonspecific alkaline phosphatase (TNAP) isozymes. Using these 1,536-well assays, concurrent HTS screens of the MLSMR library of 323,000 compounds were conducted for human and mouse IAP isozymes monitoring both inhibition and activation. This parallel screening approach led to identification of a novel inhibitory scaffold selective for murine intestinal alkaline phosphatase. SAR efforts based on parallel testing of analogs against different AP isozymes generated a potent inhibitor of the murine IAP with IC50 of 540 nM, at least 65-fold selectivity against human TNAP, and >185 selectivity against human PLAP. PMID:23860652

  1. A description of alkaline phosphatases from marine organisms

    NASA Astrophysics Data System (ADS)

    Tian, Jiyuan; Jia, Hongbing; Yu, Juan

    2015-12-01

    Alkaline phosphatases (APs) are non-specific phosphohydrolases, and they are widely used in clinical diagnostics and biological studies. APs are widespread in nature and exhibit different structural formulations. Based on the diversity of biogenetic sources, APs exhibit temperature-propensity traits, and they are classified as psychrophilic, mesophilic, and thermophilic. In this article, the characteristics of psychrophilic APs from marine organisms were described, accompanied by a simple description of APs from other organisms. This review will facilitate better utilization of marine APs in the biotechnology field.

  2. A description of alkaline phosphatases from marine organisms

    NASA Astrophysics Data System (ADS)

    Tian, Jiyuan; Jia, Hongbing; Yu, Juan

    2016-07-01

    Alkaline phosphatases (APs) are non-specific phosphohydrolases, and they are widely used in clinical diagnostics and biological studies. APs are widespread in nature and exhibit different structural formulations. Based on the diversity of biogenetic sources, APs exhibit temperature-propensity traits, and they are classified as psychrophilic, mesophilic, and thermophilic. In this article, the characteristics of psychrophilic APs from marine organisms were described, accompanied by a simple description of APs from other organisms. This review will facilitate better utilization of marine APs in the biotechnology field.

  3. Improving the hydrogen peroxide bleaching efficiency of aspen chemithermomechanical pulp by using chitosan.

    PubMed

    Li, Zongquan; Dou, Hongyan; Fu, Yingjuan; Qin, Menghua

    2015-11-01

    The presence of transition metals during the hydrogen peroxide bleaching of pulp results in the decomposition of hydrogen peroxide, which decreases the bleaching efficiency. In this study, chitosans were used as peroxide stabilizer in the alkaline hydrogen peroxide bleaching of aspen chemithermomechanical pulp (CTMP). The results showed that the brightness of the bleached CTMP increased 1.5% ISO by addition of 0.1% chitosan with 95% degree of deacetylation during peroxide bleaching. Transition metals in the form of ions or metal colloid particles, such as iron, copper and manganese, could be adsorbed by chitosans. Chitosans could inhibit the decomposition of hydrogen peroxide catalyzed by different transition metals under alkaline conditions. The ability of chitosans to inhibit peroxide decomposition depended on the type of transition metals, chitosan concentration and degree of deacetylation applied. The addition of chitosan slightly reduced the concentration of the hydroxyl radical formed during the hydrogen peroxide bleaching of aspen CTMP. PMID:26256367

  4. Hybrid Lanthanide-Actinide Peroxide Cage Clusters.

    PubMed

    Sigmon, Ginger E; Szymanowski, Jennifer E S; Carter, Korey P; Cahill, Christopher L; Burns, Peter C

    2016-03-21

    A cage cluster consisting of 31 uranyl and 9 Sm(3+) polyhedra self-assembles in an alkaline aqueous peroxide solution and crystallizes (U31Sm9). Trimers of Sm(3+) polyhedra are templated by μ3-η(2):η(2):η(2)-peroxide groups and link to oxo atoms of uranyl ions. Three such trimers link into a ring through uranyl hexagonal bipyramids, and these are attached through six polyhedra to a unit consisting of 21 uranyl hexagonal bipyramids to complete the cage. Luminescence spectra collected with an excitation wavelength of 420 nm reveal fine structure, which is not observed for a cluster containing only uranyl polyhedra. PMID:26923457

  5. Concentration of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2006-01-01

    Methods for concentrating hydrogen peroxide solutions have been described. The methods utilize a polymeric membrane separating a hydrogen peroxide solution from a sweep gas or permeate. The membrane is selective to the permeability of water over the permeability of hydrogen peroxide, thereby facilitating the concentration of the hydrogen peroxide solution through the transport of water through the membrane to the permeate. By utilizing methods in accordance with the invention, hydrogen peroxide solutions of up to 85% by volume or higher may be generated at a point of use without storing substantial quantities of the highly concentrated solutions and without requiring temperatures that would produce explosive mixtures of hydrogen peroxide vapors.

  6. Alkene anti-Dihydroxylation with Malonoyl Peroxides.

    PubMed

    Alamillo-Ferrer, Carla; Davidson, Stuart C; Rawling, Michael J; Theodoulou, Natalie H; Campbell, Matthew; Humphreys, Philip G; Kennedy, Alan R; Tomkinson, Nicholas C O

    2015-10-16

    Malonoyl peroxide 1, prepared in a single step from the commercially available diacid, is an effective reagent for the anti-dihydroxylation of alkenes. Reaction of 1 with an alkene in the presence of acetic acid at 40 °C followed by alkaline hydrolysis leads to the corresponding diol (35-92%) with up to 13:1 anti-selectivity. A mechanism consistent with experimental findings is proposed that accounts for the selectivity observed. PMID:26425839

  7. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  8. The corrosion resistance of thermoset composites in alkaline environments

    SciTech Connect

    Kelley, D.H.; Thompson, M.J.

    1998-12-31

    Corrosion engineers need guidelines for selecting thermoset resins for aggressive applications such as hot alkali and alkaline peroxide. The suitability of fiberglass-reinforced plastic (FRP) for alkaline service depends on factors such as the ester content of the resin, the unsaturated monomer composition, and the cure system. The purpose of the present paper is to show the effect of these factors on the alkaline corrosion resistance of FRP and provide corrosion engineers with the guidance needed for selecting the best epoxy vinyl ester resins for alkaline environments.

  9. Chemistry of peroxide compounds

    NASA Technical Reports Server (NTRS)

    Volnov, I. I.

    1981-01-01

    The history of Soviet research from 1866 to 1967 on peroxide compounds is reviewed. This research dealt mainly with peroxide kinetics, reactivity and characteristics, peroxide production processes, and more recently with superoxides and ozonides and emphasis on the higher oxides of group 1 and 2 elements. Solid state fluidized bed synthesis and production of high purity products based on the relative solubilities of the initial, intermediate, and final compounds and elements in liquid ammonia are discussed.

  10. On copper peroxide

    NASA Technical Reports Server (NTRS)

    Moser, L.

    1988-01-01

    The action of hydrogen superoxide on copper salts in alcoholic solutions is studied. The action of hydrogen peroxide on copper hydroxide in alcoholic suspensions, and the action of ethereal hydrogen peroxide on copper hydroxide are discussed. It is concluded that using the procedure proposed excludes almost entirely the harmful effect of hydrolysis.

  11. Benzoyl Peroxide Topical

    MedlinePlus

    Benzoyl peroxide comes in cleansing liquid or bar, lotion, cream, and gel for use on the skin. Benzoyl peroxide usually is used one or two ... the package or on your prescription label.The cleansing liquid and bar are used to wash the ...

  12. Hydrogen Peroxide Concentrator

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F.

    2007-01-01

    A relatively simple and economical process and apparatus for concentrating hydrogen peroxide from aqueous solution at the point of use have been invented. The heart of the apparatus is a vessel comprising an outer shell containing tubular membranes made of a polymer that is significantly more permeable by water than by hydrogen peroxide. The aqueous solution of hydrogen peroxide to be concentrated is fed through the interstitial spaces between the tubular membranes. An initially dry sweep gas is pumped through the interiors of the tubular membranes. Water diffuses through the membranes and is carried away as water vapor mixed into the sweep gas. Because of the removal of water, the hydrogen peroxide solution flowing from the vessel at the outlet end is more concentrated than that fed into the vessel at the inlet end. The sweep gas can be air, nitrogen, or any other gas that can be conveniently supplied in dry form and does not react chemically with hydrogen peroxide.

  13. Fuel ethanol production from alkaline peroxide pretreated corn stover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn stover (CS) has the potential to serve as an abundant low-cost feedstock for production of fuel ethanol. Due to heterogeneous complexity and recalcitrance of lignocellulosic feedstocks, pretreatment is required to break the lignin seal and/or disrupt the structure of crystalline cellulose to in...

  14. AP-Gate

    ERIC Educational Resources Information Center

    Whitman, Glenn

    2003-01-01

    In May 2001, students in the author's Advanced Placement (AP) United States History class were embroiled in a controversy surrounding the AP exam, in particular, having access to the exam's Document Based Question (DBQ) and free response portion prior to the test's administration. Prior to the exam, the College Board had provided a fifty-year time…

  15. Uranyl peroxide closed clusters containing topological squares

    SciTech Connect

    Unruh, Daniel K.; Burtner, Alicia; Pressprich, Laura; Sigmon, Ginger E.; Burns, Peter C

    2010-01-01

    Four self-assembling clusters of uranyl peroxide polyhedra have been formed in alkaline aqueous solutions and structurally characterized. These clusters consist of 28, 30, 36 and 44 uranyl polyhedra and exhibit complex new topologies. Each has a structure that contains topological squares, pentagons and hexagons. Analysis of possible topologies within boundary constraints indicates a tendency for adoption of higher symmetry topologies in these cases. Small angle X-ray scattering data demonstrated that crystals of one of these clusters can be dissolved in ultrapure water and that the clusters remain intact for at least several days.

  16. ALP (Alkaline Phosphatase) Test

    MedlinePlus

    ... known as: ALK PHOS; Alkp Formal name: Alkaline Phosphatase Related tests: AST ; ALT ; GGT ; Bilirubin ; Liver Panel ; Bone Markers ; Alkaline Phosphatase Isoenzymes; Bone Specific ALP All content on Lab ...

  17. APS Science 2006.

    SciTech Connect

    Gibson, J. M.; Fenner, R. B.; Long, G.; Borland, M.; Decker, G.

    2007-05-24

    In my five years as the Director of the Advanced Photon Source (APS), I have been fortunate to see major growth in the scientific impact from the APS. This year I am particularly enthusiastic about prospects for our longer-term future. Every scientific instrument must remain at the cutting edge to flourish. Our plans for the next generation of APS--an APS upgrade--got seriously in gear this year with strong encouragement from our users and sponsors. The most promising avenue that has emerged is the energy-recovery linac (ERL) (see article on page xx), for which we are beginning serious R&D. The ERL{at}APS would offer revolutionary performance, especially for x-ray imaging and ultrafast science, while not seriously disrupting the existing user base. I am very proud of our accelerator physics and engineering staff, who not only keep the current APS at the forefront, but were able to greatly impress our international Machine Advisory Committee with the quality of their work on the possible upgrade option (see page xx). As we prepare for long-term major upgrades, our plans to develop and optimize all the sectors at APS in the near future are advancing. Several new beamlines saw first light this year, including a dedicated powder diffraction beamline (11-BM), two instruments for inelastic x-ray scattering at sector 30, and the Center for Nanoscale Materials (CNM) Nanoprobe beamline at sector 26. Our partnership in the first x-ray free-electron laser (LCLS) to be built at Stanford contributes to revolutionary growth in ultrafast science (see page xx), and we are developing a pulse chirping scheme to get ps pulses at sector 7 of the APS within a year or so. In this report, you will find selected highlights of scientific research at the APS from calendar year 2006. The highlighted work covers diverse disciplines, from fundamental to applied science. In the article on page xx you can see the direct impact of APS research on technology. Several new products have emerged from

  18. Hydrogen peroxide poisoning.

    PubMed

    Watt, Barbara E; Proudfoot, Alex T; Vale, J Allister

    2004-01-01

    Hydrogen peroxide is an oxidising agent that is used in a number of household products, including general-purpose disinfectants, chlorine-free bleaches, fabric stain removers, contact lens disinfectants and hair dyes, and it is a component of some tooth whitening products. In industry, the principal use of hydrogen peroxide is as a bleaching agent in the manufacture of paper and pulp. Hydrogen peroxide has been employed medicinally for wound irrigation and for the sterilisation of ophthalmic and endoscopic instruments. Hydrogen peroxide causes toxicity via three main mechanisms: corrosive damage, oxygen gas formation and lipid peroxidation. Concentrated hydrogen peroxide is caustic and exposure may result in local tissue damage. Ingestion of concentrated (>35%) hydrogen peroxide can also result in the generation of substantial volumes of oxygen. Where the amount of oxygen evolved exceeds its maximum solubility in blood, venous or arterial gas embolism may occur. The mechanism of CNS damage is thought to be arterial gas embolisation with subsequent brain infarction. Rapid generation of oxygen in closed body cavities can also cause mechanical distension and there is potential for the rupture of the hollow viscus secondary to oxygen liberation. In addition, intravascular foaming following absorption can seriously impede right ventricular output and produce complete loss of cardiac output. Hydrogen peroxide can also exert a direct cytotoxic effect via lipid peroxidation. Ingestion of hydrogen peroxide may cause irritation of the gastrointestinal tract with nausea, vomiting, haematemesis and foaming at the mouth; the foam may obstruct the respiratory tract or result in pulmonary aspiration. Painful gastric distension and belching may be caused by the liberation of large volumes of oxygen in the stomach. Blistering of the mucosae and oropharyngeal burns are common following ingestion of concentrated solutions, and laryngospasm and haemorrhagic gastritis have been

  19. APS Science 2009.

    SciTech Connect

    Gibson, J. M; Mills, D. M.; Gerig, R.

    2010-05-01

    It is my pleasure to introduce the 2009 annual report of the Advanced Photon Source. This was a very good year for us. We operated with high reliability and availability, despite growing problems with obsolete systems, and our users produced a record output of publications. The number of user experiments increased by 14% from 2008 to more than 3600. We congratulate the recipients of the 2009 Nobel Prize in Chemistry-Venkatraman Ramakrishnan (Cambridge Institute for Medical Research), Thomas Steitz (Yale University), and Ada Yonath (Weizmann Institute) - who did a substantial amount of this work at APS beamlines. Thanks to the efforts of our users and staff, and the ongoing counsel of the APS Scientific Advisory Committee, we made major progress in advancing our planning for the upgrade of the APS (APS-U), producing a proposal that was positively reviewed. We hope to get formal approval in 2010 to begin the upgrade. With advocacy from our users and the support of our sponsor, the Office of Basic Energy Sciences in the Department of Energy (DOE) Office of Science, our operating budgets have grown to the level needed to more adequately staff our beamlines. We were also extremely fortunate to have received $7.9 M in American Recovery and Reinvestment Act ('stimulus') funding to acquire new detectors and improve several of our beamlines. The success of the new Linac Coherent Light Source at Stanford, the world's first x-ray free-electron laser, made us particularly proud since the undulators were designed and built by the APS. Among other highlights, we note that more than one-quarter of the 46 Energy Frontier Research Centers, funded competitively across the U.S. in 2009 by the DOE, included the Advanced Photon Source in their proposed work, which shows that synchrotron radiation, and the APS in particular, are central to energy research. While APS research covers everything from fundamental to applied science (reflected by the highlights in this report), the challenge

  20. The Peroxide Pathway

    NASA Technical Reports Server (NTRS)

    McNeal, Curtis I., Jr.; Anderson, William

    1999-01-01

    NASA's current focus on technology roadmaps as a tool for guiding investment decisions leads naturally to a discussion of NASA's roadmap for peroxide propulsion system development. NASA's new Second Generation Space Transportation System roadmap calls for an integrated Reusable Upper-Stage (RUS) engine technology demonstration in the FY03/FY04 time period. Preceding this integrated demonstration are several years of component developments and subsystem technology demonstrations. NASA and the Air Force took the first steps at developing focused upper stage technologies with the initiation of the Upper Stage Flight Experiment with Orbital Sciences in December 1997. A review of this program's peroxide propulsion development is a useful first step in establishing the peroxide propulsion pathway that could lead to a RUS demonstration in 2004.

  1. Destruction of peroxide explosives.

    PubMed

    Oxley, Jimmie C; Smith, James L; Huang, Jiaorong; Luo, Wei

    2009-09-01

    Chemicals containing multiple peroxide functionalities, such as triacetone triperoxide (TATP), diacetone diperoxide (DADP), or hexamethylene triperoxide diamine (HMTD), can be explosive. They are impractical and are not used by legitimate military groups because they are shock and heat sensitive compared to military explosives. They are attractive to terrorists because synthesis is straightforward, requiring only a few easily obtained ingredients. Physical removal of these synthesis products is highly hazardous. This paper discusses methods to degrade peroxide explosives chemically, at room temperature. A number of mixtures containing metals (e.g., zinc, copper) and metal salts (e.g., zinc sulfate, copper chloride) were found effective, some capable of destroying TATP solutions in a few hours. Strong acids proved useful against solid peroxide materials; however, on a 1 g scale, addition of concentrated sulfuric acid caused TATP to detonate. Thus, this technique should only be used to destroy small-laboratory quantities. PMID:19737243

  2. Photolysis of alkaline-earth nitrates

    NASA Astrophysics Data System (ADS)

    Kriger, L. D.; Miklin, M. B.; Dyagileva, E. P.; Anan'ev, V. A.

    2013-02-01

    Peroxynitrite and nitrite ions are the diamagnetic products of photolysis (with light at a wavelength of 253.7 nm) of alkaline-earth nitrates; the paramagnetic products and hydrogen peroxide were not found. The structural water in alkaline-earth nitrate crystals did not affect the qualitative composition of the photodecomposition products. The quantum yield of nitrite ions was 0.0012, 0.0038, 0.0078, and 0.0091 quanta-1 and that of peroxynitrite ions was 0.0070, 0.0107, 0.0286, and 0.0407 quanta-1 for Sr(NO3)2, Ba(NO3)2, Ca(NO3)2 · 4H2O, and Mg(NO3)2 · 6H2O, respectively.

  3. Hydrogen peroxide catalytic decomposition

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2010-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

  4. Advancing beyond AP Courses

    ERIC Educational Resources Information Center

    Hammond, Bruce G.

    2009-01-01

    A quiet revolution is picking up steam in the nation's private secondary schools, with broad implications for college admissions and for teaching and learning on both sides of the transition from high school to college. About 50 of the nation's leading college-preparatory schools have opted out of the College Board's Advanced Placement (AP)…

  5. APS power supply controls

    SciTech Connect

    Saunders, C.W.; Despe, O.D.

    1994-03-31

    The purpose of this document is to provide comprehensive coverage of the APS power supply control design. This includes application software, embedded controller software, networks, and hardware. The basic components will be introduced first, followed by the requirements driving the overall design. Subsequent sections will address each component of the design one by one. Latter sections will address specific applications.

  6. Alkaline "Permanent" Paper.

    ERIC Educational Resources Information Center

    Pacey, Antony

    1991-01-01

    Discussion of paper manufacturing processes and their effects on library materials focuses on the promotion of alkaline "permanent" paper, with less acid, by Canadian library preservation specialists. Standards for paper acidity are explained; advantages of alkaline paper are described, including decreased manufacturing costs; and recyclability is…

  7. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  8. Alkaline igneous rocks

    SciTech Connect

    Fitton, J.G.; Upton, B.G.J.

    1987-01-01

    In this volume, an international team of scientists provides an up-to-date overview of the nature, origin, and evolution of alkaline magmas. Particular attention is paid to carbonatites, lamprophyres, and lamproites which are rock suites of current interest not recently reviewed elsewhere. Recent work on the classical alkaline provinces of East Africa, South Greenland, and the Kola Peninsula is included together with reviews of other areas of alkaline magmatism in North and South America, East Greenland, Europe, West Africa, and the ocean basins. Other papers discuss the impact of experimental isotopic and geochemical studies of the petrogenesis of alkaline rocks. This book will be of interest to petrologists and geochemists studying alkaline igneous rocks, and to other earth scientists as a reference on the rapidly expanding field of igneous petrology.

  9. [Influences of uncommon isoenzymes on determination of alkaline phosphatase activity by dry-chemistry analyzers].

    PubMed

    Tozawa, T; Hashimoto, M

    2001-04-01

    Dry-chemistry(DC) analysis may be influenced by some matrix effects for measuring uncommon isoenzyme forms. Placental and intestinal alkaline phosphatase(AP) are overestimated by the VITROS DC, compared with results obtained with the wet-chemistry(WC) method of Bretaudiere, et al. using 2-amino-2-methyl-1-propanol (AMP) buffer, however, no such discrepancy between AP results in any DC method and that with a routine WC method recommended by Japanese Society of Clinical Chemistry in that 2-ethylaminoethanol(EAE) buffer is used, has been demonstrated. The type of buffer used affects differently the rates of AP isoenzymes activities. We therefore examined whether the presence of uncommon AP isoenzyme forms in serum caused aberrant DC results for AP in comparison with a routine WC method using EAE buffer. Here, serum samples with only liver AP and bone AP(n : 32); high-molecular-mass AP(n : 11); placental AP(n : 12); intestinal AP(n : 13) and immunoglobulin (Ig) bound AP(n : 12) were analyzed for total AP activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM 4410 and a WC analyzer: HITACHI 7350. Values obtained in all of the DCs for sera containing only liver/bone AP agreed with those with the WC method. For sera containing placental AP, the VITROS values were higher than those with the WC method, while the FUJIDRYCHEM values and the SPOTCHEM values were lower. The VITROS values and the FUJIDRYCHEM values for sera containing intestinal AP were lower than those with the WC method, while the SPOTCHEM values were higher. All of the DCs did not affect high-molecular-mass AP and Ig bound liver/bone AP types of macro AP, but underestimated Ig bound intestinal type. Ig bound intestinal AP may be sieved by DC multilayer elements. PMID:11391954

  10. Lithium peroxide primary element

    SciTech Connect

    Winsel, A.

    1982-05-04

    In a galvanic primary element of the system Li/H/sub 2/O/sub 2/, the aqueous cathode depolarizer H/sub 2/O/sub 2/ is fixated as a polyurethane gel. It can thereby be controlled and caused to react with the anode metal in accordance with the current drain requirements. This is accomplished using a ram to press the gel toward a conductor which covers the lithium anode, which may take the form of a metal grid and/or a gas diffusion electrode. The oxygen which forms in the working layer through catalytic decomposition of hydrogen peroxide creates a gas bubble when the current is interrupted or the ram is stopped, thereby interrupting the further supply of hydrogen peroxide to the catalyst.

  11. APS Science 2007.

    SciTech Connect

    Not Available

    2008-05-30

    This report provides research highlights from the Advanced Photon Source (APS). Although these highlights represent less than 10% of the published work from the APS in 2007, they give a flavor of the diversity and impact of user research at the facility. In the strategic planning the aim is to foster the growth of existing user communities and foresee new areas of research. This coming year finds the APS engaged in putting together, along with the users, a blueprint for the next five years, and making the case for a set of prioritized investments in beamlines, the accelerator, and infrastructure, each of which will be transformational in terms of scientific impact. As this is written plans are being formulated for an important user workshop on October 20-21, 2008, to prioritize strategic plans. The fruit from past investments can be seen in this report. Examples include the creation of a dedicated beamline for x-ray photon correlation spectroscopy at Sector 8, the evolution of dedicated high-energy x-ray scattering beamlines at sectors 1 and 11, a dedicated imaging beamline at Sector 32, and new beamlines for inelastic scattering and powder diffraction. A single-pulse facility has been built in collaboration with Sector 14 (BioCARS) and Phil Anfinrud at the National Institutes of Health, which will offer exceptionally high flux for single-pulse diffraction. The nanoprobe at Sector 26, built and operated jointly by the Argonne Center for Nanoscale Materials and the X-ray Operations and Research (XOR) section of the APS X-ray Science Division, has come on line to define the state of the art in nanoscience.

  12. Protein oxidation and peroxidation.

    PubMed

    Davies, Michael J

    2016-04-01

    Proteins are major targets for radicals and two-electron oxidants in biological systems due to their abundance and high rate constants for reaction. With highly reactive radicals damage occurs at multiple side-chain and backbone sites. Less reactive species show greater selectivity with regard to the residues targeted and their spatial location. Modification can result in increased side-chain hydrophilicity, side-chain and backbone fragmentation, aggregation via covalent cross-linking or hydrophobic interactions, protein unfolding and altered conformation, altered interactions with biological partners and modified turnover. In the presence of O2, high yields of peroxyl radicals and peroxides (protein peroxidation) are formed; the latter account for up to 70% of the initial oxidant flux. Protein peroxides can oxidize both proteins and other targets. One-electron reduction results in additional radicals and chain reactions with alcohols and carbonyls as major products; the latter are commonly used markers of protein damage. Direct oxidation of cysteine (and less commonly) methionine residues is a major reaction; this is typically faster than with H2O2, and results in altered protein activity and function. Unlike H2O2, which is rapidly removed by protective enzymes, protein peroxides are only slowly removed, and catabolism is a major fate. Although turnover of modified proteins by proteasomal and lysosomal enzymes, and other proteases (e.g. mitochondrial Lon), can be efficient, protein hydroperoxides inhibit these pathways and this may contribute to the accumulation of modified proteins in cells. Available evidence supports an association between protein oxidation and multiple human pathologies, but whether this link is causal remains to be established. PMID:27026395

  13. Protein oxidation and peroxidation

    PubMed Central

    Davies, Michael J.

    2016-01-01

    Proteins are major targets for radicals and two-electron oxidants in biological systems due to their abundance and high rate constants for reaction. With highly reactive radicals damage occurs at multiple side-chain and backbone sites. Less reactive species show greater selectivity with regard to the residues targeted and their spatial location. Modification can result in increased side-chain hydrophilicity, side-chain and backbone fragmentation, aggregation via covalent cross-linking or hydrophobic interactions, protein unfolding and altered conformation, altered interactions with biological partners and modified turnover. In the presence of O2, high yields of peroxyl radicals and peroxides (protein peroxidation) are formed; the latter account for up to 70% of the initial oxidant flux. Protein peroxides can oxidize both proteins and other targets. One-electron reduction results in additional radicals and chain reactions with alcohols and carbonyls as major products; the latter are commonly used markers of protein damage. Direct oxidation of cysteine (and less commonly) methionine residues is a major reaction; this is typically faster than with H2O2, and results in altered protein activity and function. Unlike H2O2, which is rapidly removed by protective enzymes, protein peroxides are only slowly removed, and catabolism is a major fate. Although turnover of modified proteins by proteasomal and lysosomal enzymes, and other proteases (e.g. mitochondrial Lon), can be efficient, protein hydroperoxides inhibit these pathways and this may contribute to the accumulation of modified proteins in cells. Available evidence supports an association between protein oxidation and multiple human pathologies, but whether this link is causal remains to be established. PMID:27026395

  14. Alkaline battery operational methodology

    DOEpatents

    Sholklapper, Tal; Gallaway, Joshua; Steingart, Daniel; Ingale, Nilesh; Nyce, Michael

    2016-08-16

    Methods of using specific operational charge and discharge parameters to extend the life of alkaline batteries are disclosed. The methods can be used with any commercial primary or secondary alkaline battery, as well as with newer alkaline battery designs, including batteries with flowing electrolyte. The methods include cycling batteries within a narrow operating voltage window, with minimum and maximum cut-off voltages that are set based on battery characteristics and environmental conditions. The narrow voltage window decreases available capacity but allows the batteries to be cycled for hundreds or thousands of times.

  15. Alkaline Phosphatase, Soluble Extracellular Adenine Nucleotides, and Adenosine Production after Infant Cardiopulmonary Bypass

    PubMed Central

    Davidson, Jesse A.; Urban, Tracy; Tong, Suhong; Twite, Mark; Woodruff, Alan

    2016-01-01

    -operative alkaline phosphatase activity leads to impaired capacity to clear adenosine monophosphate. AP supplementation improves serum clearance of adenosine monophosphate to adenosine. These findings represent a potential therapeutic mechanism for alkaline phosphatase infusion during cardiac surgery. New and Noteworthy We identify alkaline phosphatase (AP) as the primary soluble ectonucleotidase in infants undergoing cardiopulmonary bypass and show decreased capacity to clear AMP when AP activity decreases post-bypass. Supplementation of AP ex vivo improves this capacity and may represent the beneficial therapeutic mechanism of AP infusion seen in phase 2 studies. PMID:27384524

  16. Rapidly diverging evolution of an atypical alkaline phosphatase (PhoAaty) in marine phytoplankton: insights from dinoflagellate alkaline phosphatases

    PubMed Central

    Lin, Xin; Wang, Lu; Shi, Xinguo; Lin, Senjie

    2015-01-01

    Alkaline phosphatase (AP) is a key enzyme that enables marine phytoplankton to scavenge phosphorus (P) from dissolved organic phosphorus (DOP) when inorganic phosphate is scarce in the ocean. Yet how the AP gene has evolved in phytoplankton, particularly dinoflagellates, is poorly understood. We sequenced full-length AP genes and corresponding complementary DNA (cDNA) from 15 strains (10 species), representing four classes of the core dinoflagellate lineage, Gymnodiniales, Prorocentrales, Suessiales, and Gonyaulacales. Dinoflagellate AP gene sequences exhibited high variability, containing variable introns, pseudogenes, single nucleotide polymorphisms and consequent variations in amino acid sequence, indicative of gene duplication events and consistent with the “birth-and-death” model of gene evolution. Further sequence comparison showed that dinoflagellate APs likely belong to an atypical type AP (PhoAaty), which shares conserved motifs with counterparts in marine bacteria, cyanobacteria, green algae, haptophytes, and stramenopiles. Phylogenetic analysis suggested that PhoAaty probably originated from an ancestral gene in bacteria and evolved divergently in marine phytoplankton. Because variations in AP amino acid sequences may lead to differential subcellular localization and potentially different metal ion requirements, the multiple types of APs in algae may have resulted from selection for diversifying strategies to utilize DOP in the P variable marine environment. PMID:26379645

  17. Investigation on regeneration of basic hydrogen peroxide by electrochemical methods

    NASA Astrophysics Data System (ADS)

    Ke, Changchun; Chen, Wenwu; Xu, Xiaobo; Wang, Jinglong; Liu, Yushi; Jin, Yuqi; Sang, Fengting

    2015-02-01

    Two electrochemical methods for regeneration of Basic Hydrogen Peroxide (BHP) were investigated in this paper, which could be called one-step method and two-step method, respectively, distinguished by the number of steps during the regeneration process. The one-step method converts potassium chloride solution and oxygen directly to chlorine and BHP by a modified chlor-alkali cell with an oxygen cathode. For the one-step method, two reactors of different structure and corresponding regenerating process were designed. The experimental results showed that, for the continuous-type reactor, the highest peroxide concentration was 0.042 mol/L, while for batch-type reactor the highest peroxide concentration was 0.563 mol/L. The two-step method accomplishes the regeneration of BHP by a conventional chlor-alkali cell combined with a fuel cell reactor which could convert hydrogen and oxygen to peroxide in alkaline potassium hydroxide solution. A peroxide concentration of 2.450 mol/L was obtained for the two-step method.

  18. Structural and biochemical characterization of a halophilic archaeal alkaline phosphatase.

    PubMed

    Wende, Andy; Johansson, Patrik; Vollrath, Ronnald; Dyall-Smith, Mike; Oesterhelt, Dieter; Grininger, Martin

    2010-07-01

    Phosphate is an essential component of all cells that must be taken up from the environment. Prokaryotes commonly secrete alkaline phosphatases (APs) to recruit phosphate from organic compounds by hydrolysis. In this study, the AP from Halobacterium salinarum, an archaeon that lives in a saturated salt environment, has been functionally and structurally characterized. The core fold and the active-site architecture of the H. salinarum enzyme are similar to other AP structures. These generally form dimers composed of dominant beta-sheet structures sandwiched by alpha-helices and have well-accessible active sites. The surface of the enzyme is predicted to be highly negatively charged, like other proteins of extreme halophiles. In addition to the conserved core, most APs contain a crown domain that strongly varies within species. In the H. salinarum AP, the crown domain is made of an acyl-carrier-protein-like fold. Different from other APs, it is not involved in dimer formation. We compare the archaeal AP with its bacterial and eukaryotic counterparts, and we focus on the role of crown domains in enhancing protein stability, regulating enzyme function, and guiding phosphoesters into the active-site funnel. PMID:20438737

  19. Electrodeposited nanostructured MnO{sub 2} for non-enzymatic hydrogen peroxide sensing

    SciTech Connect

    Saha, B. Jana, S. K.; Banerjee, S.

    2015-06-24

    Electrodeposited MnO{sub 2} nanostructure was synthesized on indium tin oxide coated glass electrode by cyclic voltammetry. The as obtained samples were subsequently characterized by atomic force microscopy and their electro-catalytic response towards hydrogen peroxide in alkaline medium of 0.1M NaOH was studied using cyclic voltammetry and amperometry.

  20. Lipid peroxidation and tissue damage.

    PubMed

    Mylonas, C; Kouretas, D

    1999-01-01

    In recent years it has become apparent that the oxidation of lipids, or lipid peroxidation, is a crucial step in the pathogenesis of several disease states in adult and infant patients. Lipid peroxidation is a process generated naturally in small amounts in the body, mainly by the effect of several reactive oxygen species (hydroxyl radical, hydrogen peroxide etc.). It can also be generated by the action of several phagocytes. These reactive oxygen species readily attack the polyunsaturated fatty acids of the fatty acid membrane, initiating a self-propagating chain reaction. The destruction of membrane lipids and the end-products of such lipid peroxidation reactions are especially dangerous for the viability of cells, even tissues. Enzymatic (catalase, superoxide dismutasse) and nonenzymatic (vitamins A and E) natural antioxidant defence mechanisms exist; however, these mechanisms may be overcome, causing lipid peroxidation to take place. Since lipid peroxidation is a self-propagating chain-reaction, the initial oxidation of only a few lipid molecules can result in significant tissue damage. Despite extensive research in the field of lipid peroxidation it has not yet been precisely determined if it is the cause or an effect of several pathological conditions. Lipid peroxidation has been implicated in disease states such as atherosclerosis, IBD, ROP, BPD, asthma, Parkinson's disease, kidney damage, preeclampsia and others. PMID:10459507

  1. Alkaline flooding injection strategy

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1992-03-01

    The objective of this project is to improved alkali-surfactant flooding methods, and this includes determining the proper design of injection strategy. Several different injection strategies have been used or suggested for recovering heavy oils with surfactant-enhanced alkaline flooding methods. Oil recovery was compared for four different injection strategies: (1) surfactant followed by polymer, (2) surfactant followed by alkaline polymer, (3) alkaline surfactant followed by polymer, and (4) alkali, surfactant, and polymer mixed in a single formulation. The effect of alkaline preflush was also studied under two different conditions. All of the oil recovery experiments were conducted under optimal conditions with a viscous, non-acidic oil from Hepler (KS) oil field. The coreflood experiments were conducted with Berea sandstone cores since field core was not available in sufficient quantity for coreflood tests. The Tucker sand of Hepler field is a Class I fluvial dominated deltaic reservoir, as classified by the Department of Energy, which has been selected as the site of a DOE-sponsored field pilot test.

  2. Biodistribution and translational pharmacokinetic modeling of a human recombinant alkaline phosphatase.

    PubMed

    Peters, Esther; Stevens, Jasper; Arend, Jacques; Guan, Zheng; Raaben, Willem; Laverman, Peter; van Elsas, Andrea; Masereeuw, Rosalinde; Pickkers, Peter

    2015-11-10

    Clinical trials showed renal protective effects of bovine intestinal alkaline phosphatase (AP) in patients with sepsis-associated acute kidney injury (AKI). Subsequently, a human recombinant chimeric AP (recAP) was developed as a pharmaceutically acceptable alternative. Here, we investigated the biodistribution and pharmacokinetics (PK) of recAP and developed a translational population PK model. Biodistribution was studied during LPS-induced AKI in rats. Iodine-125-labeled recAP was primarily taken up by liver, spleen, adrenals, heart, lungs and kidneys followed by the gastro-intestinal tract and thyroid. Tissue distribution was not critically affected by endotoxemia. PK parameters were determined in rats and minipigs during IV bolus injections of recAP, administered once, or once daily during seven consecutive days. Plasma concentrations of recAP increased with increasing dose and disappeared in a biphasic manner. Exposure to recAP, estimated by AUC and Cmax, was similar on days 1 and 7. Subsequently, population approach nonlinear mixed effects modeling was performed with recAP rat and minipig and biAP phase I PK data. Concentration versus time data was accurately described in all species by a two-compartmental model with allometric scaling based on body weight. This model provides a solid foundation for determining the optimal dose and duration of first-in-man recAP studies. PMID:26325308

  3. Performance of direct formate-peroxide fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Yinshi; Wu, Hao; He, Yaling; Liu, Yue; Jin, Lei

    2015-08-01

    We report the high-performance direct formate-peroxide fuel cells (DFPFCs) that consist of a cation-exchange membrane sandwiched between an alkaline formate anode and an acid peroxide cathode. Much attention has been paid to investigate the effects of different composite parameters and operating parameters, including catalyst loadings at both anode and cathode electrodes, operating temperatures, as well as the concentrations of both formate and electrolyte solutions. It is demonstrated that the optimization of both the electrode composition (anode 2.0 mgPd cm-2, cathode 2.0 mgPt cm-2) and the solution concentration (1.0 M HCOONa-3.0 M NaOH) enables the DFPFC to yield a peak power density as high as 591 mW cm-2 at 60 °C, which is about one times higher than that of state-of-the-art anion-exchange membrane direct formate fuel cells.

  4. AP-42 REVISION: COKE OVENS

    EPA Science Inventory

    The document "Compilation of Air Pollutant Emission Factors" (AP-42) has been published by the U. S. Environmental Protection Agency (EPA) since 1972. Supplements to AP-42 have been routinely published to add new emission source categories and to update existing emission factor...

  5. Characterization and Oxidation of Chromium(III) by Sodium Hypochlorite in Alkaline Solutions

    SciTech Connect

    Jiang, Huijian; Rao, Linfeng; Zhang, Zhicheng; Rai, Dhanpat

    2006-07-01

    Chromium exists in nuclear waste sludges and is a problematic element in the vitrification process of high-level nuclear wastes. It is therefore necessary to treat the waste sludges to remove chromium prior to vitrification, by caustic leaching or oxidation of Cr(III) to Cr(VI). The objective of this study is to investigate the effect of oligomerization of Cr(III) on its oxidation by hypochlorite in alkaline solutions. Monomeric, dimeric and trimeric Cr(III) species in solution were separated by ion exchange. The kinetics of the oxidation of the separated species by hypochlorite in alkaline solutions was studied by UV/Vis absorption spectroscopy, and compared with the oxidation by hydrogen peroxide previously studied. Results indicate that hypochlorite can oxidize Cr(III) to Cr(VI) in alkaline solutions, but the rate of oxidation by hypochlorite is slower than that by hydrogen peroxide at the same alkalinity and concentrations of oxidants. The rate of oxidation of Cr(III) by both oxidants decreases as the concentration of sodium hydroxide is increased, but the oxidation by hypochlorite seems less affected by the degree of oligomerization of Cr(III) than that by peroxide. Compared with the oxidation by hydrogen peroxide where the major reaction pathway has an inverse order with respect to CNaOH, the oxidation by hypochlorite has a significant reaction pathway independent of [OH?].

  6. Tested Demonstrations. The Stepwise Reduction of Permanganate in Alkaline Conditions: A Lecture Demonstration.

    ERIC Educational Resources Information Center

    Ruoff, Peter; Riley, Megan

    1987-01-01

    Describes a chemistry experiment where an alkaline ice-cold permanganate solution is reduced by adding dropwise a cold diluted hydrogen peroxide solution. Outlines the course of the reduction through the various oxidation states of manganese with their characteristic colors. (TW)

  7. APS controls overview

    SciTech Connect

    1996-02-01

    The APS accelerator control system described in this report is a distributed system consisting of operator interfaces, a network, and interfaces to hardware. The operator interface is a UNIX-based workstation with an X-windows graphical user interface. The workstation may be located at any point on the facility network and maintain full functionality. The user has the ability to generate and alter control displays and to access the alarm handler, the archiver, interactive control programs, custom code, and other tools. The TCP/EP networking protocol has been selected as the underlying protocol for the control system network. TCP/EP is a commercial standard and readily available from network hardware vendors. Its implementation is independent of the particular network medium selected to implement the controls network. In the development environment copper Ethernet is the network medium; however, in the actual implementation a fiber-based system using hub technology will be utilized. The function of the network is to provide a generalized communication path between the host computers, operator workstations, input/output crates, and other hardware that comprise the control system.

  8. Final report for tank 241-AP-101, grab samples 1AP-95-1, 1AP-95-2, 1AP-95-3, 1AP-95-4, 1AP-95-5, and 1AP-95-6

    SciTech Connect

    Esch, R.A.

    1996-03-04

    Six supernate grab samples (1AP-95-1 through 6) and one field blank (1AP-95-7) were taken from tank 241-AP-101, on Nov. 10 and 13, 1995. Analyses were performed in support of the Safety Screening and the Waste Compatibility Safety programs. All analytical results were within the action limits stated in the TSAP.

  9. Dearomatization Reactions Using Phthaloyl Peroxide.

    PubMed

    Eliasen, Anders M; Christy, Mitchell; Claussen, Karin R; Besandre, Ronald; Thedford, Randal P; Siegel, Dionicio

    2015-09-18

    A new oxidative dearomatization reaction has been developed using phthaloyl peroxide to chemoselectively install two oxygen-carbon bonds into aromatic precursors. The oxidation reaction proceeds only once; addition of superstoichiometric equivalents of phthaloyl peroxide does not react further with the newly generated 1,3-cyclohexadiene. The reaction has been challenged by the addition of different functional groups and shown to maintain chemoselectivity. Due to the broad reactivity with 1,2-methylenedioxybenzene derivatives, linear free energy correlations were determined and support a mechanism proceeding through diradicals analogous to arene-hydroxylation reactions using phthaloyl peroxide. PMID:26333308

  10. The influence of complexing pharmaceutical compositions on alkaline phosphatase

    NASA Astrophysics Data System (ADS)

    Atyaksheva, L. F.; Chukhrai, E. S.; Stepina, N. D.; Novikova, N. N.; Yur'eva, E. A.

    2011-06-01

    It is established that the pharmaceutical compositions xydiphon, medifon, succimer, and EDTA, which are used as complexing agents for accelerating the excretion of heavy metals from human organism, at certain concentrations inhibit enzyme alkaline phosphatase (AP). It is concluded that xydiphon and EDTA have a noticeable effect on AP activity at concentrations over 0.01 mM; medifon and succimer, at concentrations of over 0.3-0.5 mM. The enzyme's inhibition constants and type of inhibition are determined. Xydiphon is found to manifest the highest affinity to AP ( K I = 0.35 mM). It is shown by kinetic analysis that dissociative chemoinactivation of the enzyme takes place under the action of complexing agents. The corresponding kinetic parameters are calculated.

  11. Net alkalinity and net acidity 2: Practical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A., III

    2005-01-01

    The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH < 6.3 after oxidation had positive Hot Acidity. Samples with similar pH values before oxidation had dissimilar Hot Acidities due to variations in their alkalinities and dissolved Fe, Mn, and Al concentrations. Hot Acidity was approximately equal to net acidity calculated based on initial pH and dissolved concentrations of Fe, Mn, and Al minus the

  12. Alkaline quinone flow battery.

    PubMed

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy. PMID:26404834

  13. Net alkalinity and net acidity 1: Theoretical considerations

    USGS Publications Warehouse

    Kirby, C.S.; Cravotta, C.A., III

    2005-01-01

    standard method "hot peroxide" acidity titration, provided that labs report negative values. The authors recommend the third approach; i.e., net alkalinity = -Hot Acidity. ?? 2005 Elsevier Ltd. All rights reserved.

  14. Stabilized aqueous hydrogen peroxide solution

    SciTech Connect

    Malin, M.J.; Sciafani, L.D.

    1988-05-17

    This patent describes a stabilized aqueous hydrogen peroxide solution having a pH below 7 and an amount of Ferric ion up to about 2 ppm comprising hydrogen peroxide, acetanilide having a concentration which ranges between 0.74 M Mol/L and 2.22 mMol/L, and o-benzene disulfonic acid or salt thereof at a concentration between about 0.86 mMol/L to about 1.62 mMol/L.

  15. Arene oxidation with malonoyl peroxides.

    PubMed

    Dragan, Andrei; Kubczyk, Tomasz M; Rowley, Julian H; Sproules, Stephen; Tomkinson, Nicholas C O

    2015-06-01

    Malonoyl peroxide 7, prepared in a single step from the commercially available diacid, is an effective reagent for the oxidation of aromatics. Reaction of an arene with peroxide 7 at room temperature leads to the corresponding protected phenol which can be unmasked by aminolysis. An ionic mechanism consistent with the experimental findings and supported by isotopic labeling, Hammett analysis, EPR investigations, and reactivity profile studies is proposed. PMID:25966313

  16. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  17. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  18. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  19. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... acetone peroxide, with minor proportions of higher polymers, manufactured by reaction of hydrogen peroxide... grams to 10 grams of hydrogen peroxide equivalent per 100 grams of the additive, plus carrier, for use in flour maturing and bleaching; or (2) approximately 0.75 gram of hydrogen peroxide equivalent...

  20. Structural characteristics of alkaline phosphatase from the moderately halophilic bacterium Halomonas sp. 593

    SciTech Connect

    Arai, Shigeki; Yonezawa, Yasushi; Ishibashi, Matsujiro; Matsumoto, Fumiko; Adachi, Motoyasu; Tamada, Taro; Tokunaga, Hiroko; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2014-03-01

    In order to clarify the structural basis of the halophilic characteristics of an alkaline phosphatase derived from the moderate halophile Halomonas sp. 593 (HaAP), the tertiary structure of HaAP was determined to 2.1 Å resolution by X-ray crystallography. The structural properties of surface negative charge and core hydrophobicity were shown to be intermediate between those characteristic of halophiles and non-halophiles, and may explain the unique functional adaptation to a wide range of salt concentrations. Alkaline phosphatase (AP) from the moderate halophilic bacterium Halomonas sp. 593 (HaAP) catalyzes the hydrolysis of phosphomonoesters over a wide salt-concentration range (1–4 M NaCl). In order to clarify the structural basis of its halophilic characteristics and its wide-range adaptation to salt concentration, the tertiary structure of HaAP was determined by X-ray crystallography to 2.1 Å resolution. The unit cell of HaAP contained one dimer unit corresponding to the biological unit. The monomer structure of HaAP contains a domain comprised of an 11-stranded β-sheet core with 19 surrounding α-helices similar to those of APs from other species, and a unique ‘crown’ domain containing an extended ‘arm’ structure that participates in formation of a hydrophobic cluster at the entrance to the substrate-binding site. The HaAP structure also displays a unique distribution of negatively charged residues and hydrophobic residues in comparison to other known AP structures. AP from Vibrio sp. G15-21 (VAP; a slight halophile) has the highest similarity in sequence (70.0% identity) and structure (C{sup α} r.m.s.d. of 0.82 Å for the monomer) to HaAP. The surface of the HaAP dimer is substantially more acidic than that of the VAP dimer (144 exposed Asp/Glu residues versus 114, respectively), and thus may enable the solubility of HaAP under high-salt conditions. Conversely, the monomer unit of HaAP formed a substantially larger hydrophobic interior

  1. Meet the APS Journal Editors

    NASA Astrophysics Data System (ADS)

    2016-05-01

    The Editors of the APS journals invite you to join them for conversation. The Editors will be available to answer questions, hear your ideas, and discuss any comments about the journals. All are welcome. Light refreshments will be served.

  2. Characterization of alkaline phosphatase activity in seminal plasma and in fresh and frozen-thawed stallion spermatozoa.

    PubMed

    Bucci, Diego; Giaretta, Elisa; Spinaci, Marcella; Rizzato, Giovanni; Isani, Gloria; Mislei, Beatrice; Mari, Gaetano; Tamanini, Carlo; Galeati, Giovanna

    2016-01-15

    Alkaline phosphatase (AP) has been studied in several situations to elucidate its role in reproductive biology of the male from different mammalian species; at present, its role in horse sperm physiology is not clear. The aim of the present work was to measure AP activity in seminal plasma and sperm extracts from freshly ejaculated as well as in frozen-thawed stallion spermatozoa and to verify whether relationship exists between AP activity and sperm quality parameters. Our data on 40 freshly ejaculated samples from 10 different stallions demonstrate that the main source of AP activity is seminal plasma, whereas sperm extracts contribution is very low. In addition, we found that AP activity at physiological pH (7.0) is significantly lower than that observed at pH 8.0, including the optimal AP pH (pH 10.0). Alkaline phosphatase did not exert any effect on sperm-oocyte interaction assessed by heterologous oocyte binding assay. Additionally, we observed a thermal stability of seminal plasma AP, concluding that it is similar to that of bone isoforms. Positive correlations were found between seminal plasma AP activity and sperm concentration, whereas a negative correlation was present between both spermatozoa extracts and seminal plasma AP activity and seminal plasma protein content. A significant decrease in sperm extract AP activity was found in frozen-thawed samples compared with freshly ejaculated ones (n = 21), concomitantly with the decrease in sperm quality parameters. The positive correlation between seminal plasma AP activity measured at pH 10 and viability of frozen-thawed spermatozoa suggests that seminal plasma AP activity could be used as an additional predictive parameter for stallion sperm freezability. In conclusion, we provide some insights into AP activity in both seminal plasma and sperm extracts and describe a decrease in AP after freezing and thawing. PMID:26433714

  3. SERUM VALUES OF ALKALINE PHOSPHATASE AND LACTATE DEHYDROGENASE IN OSTEOSARCOMA

    PubMed Central

    ZUMÁRRAGA, JUAN PABLO; BAPTISTA, ANDRÉ MATHIAS; ROSA, LUIS PABLO DE LA; CAIERO, MARCELO TADEU; CAMARGO, OLAVO PIRES DE

    2016-01-01

    ABSTRACT Objective: To study the relationship between the pre and post chemotherapy (CT) serum levels of alkaline phosphatase (AP) and lactate dehydrogenase (LDH), and the percentage of tumor necrosis (TN) found in specimens after the pre surgical CT in patients with osteosarcoma. Methods: Series of cases with retrospective evaluation of patients diagnosed with osteosarcoma. Participants were divided into two groups according to serum values of both enzymes. The values of AP and LDH were obtained before and after preoperative CT. The percentage of tumor necrosis (TN) of surgical specimens of each patient was also included. Results: One hundred and thirty seven medical records were included from 1990 to 2013. Both the AP as LDH decreased in the patients studied, being the higher in pre CT than post CT. The average LHD decrease was 795.12U/L and AP decrease was 437.40 U/L. The average TN was 34.10 %. There was no statistically significant correlation between the serums values and the percentage of tumoral necrosis. Conclusion: The serum levels values of AP and LDH are not good predictors for the chemotherapy-induced necrosis in patients with osteosarcoma. Level of Evidence IV, Case Series. PMID:27217815

  4. Alkaline Phosphatase in Stem Cells

    PubMed Central

    Štefková, Kateřina; Procházková, Jiřina; Pacherník, Jiří

    2015-01-01

    Alkaline phosphatase is an enzyme commonly expressed in almost all living organisms. In humans and other mammals, determinations of the expression and activity of alkaline phosphatase have frequently been used for cell determination in developmental studies and/or within clinical trials. Alkaline phosphatase also seems to be one of the key markers in the identification of pluripotent embryonic stem as well as related cells. However, alkaline phosphatases exist in some isoenzymes and isoforms, which have tissue specific expressions and functions. Here, the role of alkaline phosphatase as a stem cell marker is discussed in detail. First, we briefly summarize contemporary knowledge of mammalian alkaline phosphatases in general. Second, we focus on the known facts of its role in and potential significance for the identification of stem cells. PMID:25767512

  5. Alkaline fuel cells applications

    NASA Astrophysics Data System (ADS)

    Kordesch, Karl; Hacker, Viktor; Gsellmann, Josef; Cifrain, Martin; Faleschini, Gottfried; Enzinger, Peter; Fankhauser, Robert; Ortner, Markus; Muhr, Michael; Aronson, Robert R.

    On the world-wide automobile market technical developments are increasingly determined by the dramatic restriction on emissions as well as the regimentation of fuel consumption by legislation. Therefore there is an increasing chance of a completely new technology breakthrough if it offers new opportunities, meeting the requirements of resource preservation and emission restrictions. Fuel cell technology offers the possibility to excel in today's motive power techniques in terms of environmental compatibility, consumer's profit, costs of maintenance and efficiency. The key question is economy. This will be decided by the costs of fuel cell systems if they are to be used as power generators for future electric vehicles. The alkaline hydrogen-air fuel cell system with circulating KOH electrolyte and low-cost catalysed carbon electrodes could be a promising alternative. Based on the experiences of Kordesch [K. Kordesch, Brennstoffbatterien, Springer, Wien, 1984, ISBN 3-387-81819-7; K. Kordesch, City car with H 2-air fuel cell and lead-battery, SAE Paper No. 719015, 6th IECEC, 1971], who operated a city car hybrid vehicle on public roads for 3 years in the early 1970s, improved air electrodes plus new variations of the bipolar stack assembly developed in Graz are investigated. Primary fuel choice will be a major issue until such time as cost-effective, on-board hydrogen storage is developed. Ammonia is an interesting option. The whole system, ammonia dissociator plus alkaline fuel cell (AFC), is characterised by a simple design and high efficiency.

  6. Measurement of bone specific alkaline phosphatase in the horse: a comparison of two techniques.

    PubMed

    Jackson, B; Eastell, R; Russell, R G; Lanyon, L E; Price, J S

    1996-09-01

    For many years total alkaline phosphatase (AP) activity in serum has been used to monitor bone metabolism in different species. However, total AP lacks bone specificity because the total activity in serum is made up of several isoenzymes, of which the liver and bone isoforms predominate. The aim of the present study was to evaluate an immunoradiometric assay for measuring bone specific alkaline phosphatase (BAP) in horses. BAP, a specific marker of bone formation, was measured in sera from thoroughbred horses by using a previously characterised wheat germ lectin (WGL) precipitation assay and an immunoradiometric assay. The levels of immunoreactive BAP (iBAP) and WGL precipitated BAP (wBAP) were related to the serum levels of total AP and another marker of bone formation, the carboxy-terminal propeptide of type 1 collagen (PICP). In horses over one year old, iBAP correlated at least as strongly with total AP as with wBAP, which suggests that the immunoradiometric assay may partially cross-react with liver alkaline phosphatase in horse serum. This possibility was supported by the observation that there was a weaker correlation between iBAP and PICP than between wBAP and PICP. These data indicate that WGL precipitation is currently the most specific method for measuring bone specific alkaline phosphatase in horses. PMID:8880988

  7. CONTROL OF ALKALINE PHOSPHATASE ACTIVITY IN C3H10T1/2 CELLS: ROLE OF RETINOIC ACID AND CELL DENSITY

    EPA Science Inventory

    The enzyme alkaline phosphatase (AP) has been shown to be lost or inappropriately expressed during carcinogenesis in some tissues. ecause retinoic acid (RA) appears to play a role in the normal regulation of the enzyme (RA up-regulates AP in a variety of cell types) we have sugge...

  8. A critical reinvestigation of the TAED-activated peroxide system for low-temperature bleaching of cotton.

    PubMed

    Xu, Changhai; Long, Xiaoxia; Du, Jinmei; Fu, Shaohai

    2013-01-30

    There exists a misunderstanding on the TAED-activated peroxide system in the textile industry that H(2)O(2) used in excess of the stoichiometric amount could produce an addition effect on bleaching of cotton under alkaline conditions. In this study, a critical reinvestigation was carried out on the TAED-activated peroxide system for bleaching of cotton. It was found that the TAED-activated peroxide system achieved its best performance under near-neutral pH conditions. No addition effect was observed when an excessive amount of H(2)O(2) was used under alkaline conditions, which is probably due to the base-catalyzed bimolecular decomposition of peracetic acid and the nucleophilic attack by H(2)O(2) on peracetic acid. NaHCO(3) was shown to be a desired alkaline agent for maintaining near-neutral pH for the TAED-activated peroxide system. This study provides new insight into the application of the TAED-activated peroxide system for low-temperature bleaching of cotton under more environmentally benign conditions. PMID:23218291

  9. Dephosphorylation of endotoxin by alkaline phosphatase in vivo.

    PubMed Central

    Poelstra, K.; Bakker, W. W.; Klok, P. A.; Kamps, J. A.; Hardonk, M. J.; Meijer, D. K.

    1997-01-01

    Natural substrates for alkaline phosphatase (AP) are at present not identified despite extensive investigations. Difficulties in imagining a possible physiological function involve its extremely high pH optimum for the usual exogenous substrates and its localization as an ecto-enzyme. As endotoxin is a substance that contains phosphate groups and is usually present in the extracellular space, we studied whether AP is able to dephosphorylate this bacterial product at physiological pH levels. We tested this in intestinal cryostat sections using histochemical methods with endotoxin from Escherichia coli and Salmonella minnesota R595 as substrate. Results show that dephosphorylation of both preparations occurs at pH 7.5 by AP activity. As phosphate residues in the lipid A moiety determine the toxicity of the molecule, we examined the effect of the AP inhibitor levamisole in vivo using a septicemia model in the rat. The results show that inhibition of endogenous AP by levamisole significantly reduces survival of rats intraperitoneally injected with E. coli bacteria, whereas this drug does not influence survival of rats receiving a sublethal dose of the gram-positive bacteria Staphylococcus aureus. In view of the endotoxin-dephosphorylating properties of AP demonstrated in vitro, we propose a crucial role for this enzyme in host defense. The effects of levamisole during gram-negative bacterial infections and the localization of AP as an ecto-enzyme in most organs as well as the induction of enzyme activity during inflammatory reactions and cholestasis is in accordance with such a protective role. Images Figure 1 Figure 5 PMID:9327750

  10. APS Education and Diversity Efforts

    NASA Astrophysics Data System (ADS)

    Prestridge, Katherine; Hodapp, Theodore

    2015-11-01

    American Physical Society (APS) has a wide range of education and diversity programs and activities, including programs that improve physics education, increase diversity, provide outreach to the public, and impact public policy. We present the latest programs spearheaded by the Committee on the Status of Women in Physics (CSWP), with highlights from other diversity and education efforts. The CSWP is working to increase the fraction of women in physics, understand and implement solutions for gender-specific issues, enhance professional development opportunities for women in physics, and remedy issues that impact gender inequality in physics. The Conferences for Undergraduate Women in Physics, Professional Skills Development Workshops, and our new Professional Skills program for students and postdocs are all working towards meeting these goals. The CSWP also has site visit and conversation visit programs, where department chairs request that the APS assess the climate for women in their departments or facilitate climate discussions. APS also has two significant programs to increase participation by underrepresented minorities (URM). The newest program, the APS National Mentoring Community, is working to provide mentoring to URM undergraduates, and the APS Bridge Program is an established effort that is dramatically increasing the number of URM PhDs in physics.

  11. Progress toward hydrogen peroxide micropulsion

    SciTech Connect

    Whitehead, J C; Dittman, M D; Ledebuhr, A G

    1999-07-08

    A new self-pressurizing propulsion system has liquid thrusters and gas jet attitude control without heavy gas storage vessels. A pump boosts the pressure of a small fraction of the hydrogen peroxide, so that reacted propellant can controllably pressurize its own source tank. The warm decomposition gas also powers the pump and is supplied to the attitude control jets. The system has been incorporated into a prototype microsatellite for terrestrial maneuvering tests. Additional progress includes preliminary testing of a bipropellant thruster, and storage of unstabilized hydrogen peroxide in small sealed tanks.

  12. Comparative Study on Oxidative Treatments of NAPL Containing Chlorinated Ethanes and Ethenes using Hydrogen Peroxide and Persulfate in Soils

    EPA Science Inventory

    The goal of this study was to assess the oxidation of NAPL in soil, 30% of which were composed of chlorinated ethanes and ethenes, using catalyzed hydrogen peroxide (CHP), activated persulfate (AP), and H2O2–persulfate (HP) co-amendment systems. Citrate, a buffer and iron ligand,...

  13. AP Human Geography and Success on the AP Test

    ERIC Educational Resources Information Center

    Roncone, John; Newhalfen, Nate

    2013-01-01

    Classroom projects that explore culture and globalization enhance the curriculum and help students see how geography directly connects to their lives. These authors contend that a project-based approach can supplement the teaching of an AP Human Geography course, and visualize this course as an essential tool for students to truly understand how…

  14. Silica in alkaline brines

    USGS Publications Warehouse

    Jones, B.F.; Rettig, S.L.; Eugster, H.P.

    1967-01-01

    Analysis of sodium carbonate-bicarbonate brines from closed basins in volcanic terranes of Oregon and Kenya reveals silica contents of up to 2700 parts per million at pH's higher than 10. These high concentrations of SiO 2 can be attributed to reaction of waters with silicates, and subsequent evaporative concentration accompanied by a rise in pH. Supersaturation with respect to amorphous silica may occur and persist for brines that are out of contact with silicate muds and undersaturated with respect to trona; correlation of SiO2 with concentration of Na and total CO2 support this interpretation. Addition of moredilute waters to alkaline brines may lower the pH and cause inorganic precipitation of substantial amounts of silica.

  15. Bifunctional alkaline oxygen electrodes

    NASA Technical Reports Server (NTRS)

    Swette, L.; Kackley, N.; Mccatty, S. A.

    1991-01-01

    The authors describe the identification and testing of electrocatalysts and supports for the positive electrode of moderate-temperature, single-unit, rechargeable alkaline fuel cells. Recent work on Na(x)Pt3O4, a potential bifunctional catalyst, is described, as well as the application of novel approaches to the development of more efficient bifunctional electrode structures. The three dual-character electrodes considered here showed similar superior performance; the Pt/RhO2 and Rh/RhO2 electrodes showed slightly better performance than the Pt/IrO2 electrode. It is concluded that Na(x)Pt3O4 continues to be a promising bifunctional oxygen electrode catalyst but requires further investigation and development.

  16. AP Geography, Environmental Science Thrive

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2012-01-01

    Geography may not be particularly known as a hot topic among today's students--even some advocates suggest it suffers from an image problem--but by at least one measure, the subject is starting to come into its own. Across more than 30 topics covered in the Advanced Placement (AP) program, participation in geography is rising faster than any…

  17. Coaching in the AP Classroom

    ERIC Educational Resources Information Center

    Fornaciari, Jim

    2013-01-01

    Many parallels exist between quality coaches and quality classroom teachers--especially AP teachers, who often feel the pressure to produce positive test results. Having developed a series of techniques and strategies for building a team-oriented winning culture on the field, Jim Fornaciari writes about how he adapted those methods to work in the…

  18. Platinum-rare earth cathodes for direct borohydride-peroxide fuel cells

    NASA Astrophysics Data System (ADS)

    Cardoso, D. S. P.; Santos, D. M. F.; Šljukić, B.; Sequeira, C. A. C.; Macciò, D.; Saccone, A.

    2016-03-01

    Hydrogen peroxide (H2O2) is being actively investigated as an oxidant for direct borohydride fuel cells. Herein, platinum-rare earth (RE = Sm, Dy, Ho) alloys are prepared by arc melting and their activity for hydrogen peroxide reduction reaction (HPRR) is studied in alkaline media. Cyclic voltammetry and chronoamperometry measurements show that Pt-Sm electrode displays the highest catalytic activity for HPRR with the lowest activation energy, followed by Pt-Ho, while Pt-Dy alloys show practically no activity. Laboratory direct borohydride-peroxide fuel cells (DBPFCs) are assembled using these alloys. The DBPFC with Pt-Sm cathode gives the highest peak power density of 85 mW cm-2, which is more than double of that obtained in a DBPFC with Pt electrodes.

  19. Improved dual flow aluminum hydrogen peroxide battery

    NASA Astrophysics Data System (ADS)

    Marsh, Catherine; Licht, Stuart L.; Matthews, Donna

    1993-11-01

    A novel dual flow battery configuration is provided comprising an aqueous hydrogen peroxide catholyte, an aqueous anolyte, a porous solid electrocatalyst capable of reducing said hydrogen peroxide and separating said anolyte, and an aluminum anode positioned within said anolyte. Separation of catholyte and anolyte chambers prevents hydrogen peroxide poisoning of the aluminum anode.

  20. Inner-shell excitation spectroscopy of peroxides

    NASA Astrophysics Data System (ADS)

    Harding, K. L.; Kalirai, S.; Hayes, R.; Ju, V.; Cooper, G.; Hitchcock, A. P.; Thompson, M. R.

    2015-11-01

    O 1s inner-shell excitation spectra of a number of vapor phase molecules containing peroxide bonds - hydrogen peroxide (H2O2), di-t-butylperoxide (tBuOtBu), benzoyl peroxide, ((C6H5(CO)O)2), luperox-F [1,3(4)-bis(tertbutylperoxyisopropyl) benzene], and analogous, non-peroxide compounds - water, t-butanol and benzoic acid have been measured. C 1s spectra are also reported. O 1s spectra of solid benzoic acid, di-t-butylperoxide and luperox-F recorded using a scanning transmission X-ray microscope, are also reported, and compared to the corresponding gaseous spectra. Spectral interpretation was aided by comparing the spectra of the peroxide and non-peroxide counterparts and with ab initio calculations. A characteristic O 1s → σ∗O-O transition at 533.0(3) eV is identified in each peroxide species, which is absent in the corresponding non-peroxide counterpart species. The energy and intensity of the 533 eV peroxide feature is stable and thus useful for analysis of peroxides in mixtures, such as tracking residual peroxide initiators, or peroxides produced in fuel cells.

  1. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....C. 552(a) and 1 CFR part 51. You may obtain copies from the United States Pharmacopeial Convention... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may...

  2. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  3. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  4. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  5. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....C. 552(a) and 1 CFR part 51. You may obtain copies from the United States Pharmacopeial Convention... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may...

  6. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  7. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....C. 552(a) and 1 CFR part 51. You may obtain copies from the United States Pharmacopeial Convention... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... Specific Usage Additives § 173.356 Hydrogen peroxide. Hydrogen peroxide (CAS Reg. No. 7722-84-1) may...

  8. Safety Tips: Peroxides Can Be Treacherous.

    ERIC Educational Resources Information Center

    Nagel, Miriam C.

    1984-01-01

    Peroxides are unstable, shock-, thermal-, and friction-sensitive compounds whose sensitivity increases with concentration. In addition, peroxides can form in aging organic solvents and stored alkali metals. Cautions related to storage, use, and disposal of peroxides in the secondary school chemistry laboratory are discussed. (JN)

  9. 21 CFR 582.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrogen peroxide. 582.1366 Section 582.1366 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1366 Hydrogen peroxide. (a) Product. Hydrogen peroxide. (b) (c) Limitations,...

  10. Sampling Stoichiometry: The Decomposition of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Clift, Philip A.

    1992-01-01

    Describes a demonstration of the decomposition of hydrogen peroxide to provide an interesting, quantitative illustration of the stoichiometric relationship between the decomposition of hydrogen peroxide and the formation of oxygen gas. This 10-minute demonstration uses ordinary hydrogen peroxide and yeast that can be purchased in a supermarket.…

  11. Complete nucleotide sequence of the structural gene for alkaline proteinase from Pseudomonas aeruginosa IFO 3455.

    PubMed Central

    Okuda, K; Morihara, K; Atsumi, Y; Takeuchi, H; Kawamoto, S; Kawasaki, H; Suzuki, K; Fukushima, J

    1990-01-01

    The DNA-encoding alkaline proteinase (AP) of Pseudomonas aeruginosa IFO 3455 was cloned, and its complete nucleotide sequence was determined. When the cloned gene was ligated to pUC18, the Escherichia coli expression vector, the gene-incorporated bacteria expressed high levels of both AP activity and AP antigens. The amino acid sequence deduced from the nucleotide sequence revealed that the mature AP consists of 467 amino acids with a relative molecular weight of 49,507. The amino acid composition predicted from the DNA sequence was similar to the chemically determined composition of purified AP reported previously. The amino acid sequence analysis revealed that both the N-terminal side sequence of the purified AP and several internal lysyl peptide fragments were identical to the deduced amino acid sequences. The percent homology of amino acid sequences between AP and Serratia protease was about 55%. The zinc ligands and an active site of the AP were predicted by comparing the structure of the enzyme with of Serratia protease, thermolysin, Bacillus subtilis neutral protease, and Pseudomonas elastase. PMID:2123832

  12. Alkaline battery, separator therefore

    NASA Technical Reports Server (NTRS)

    Schmidt, George F. (Inventor)

    1980-01-01

    An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition. When the salt is formed, it expands the polymeric chains of the binder to provide a film coating substantially permeable to electrolyte ion transfer but relatively impermeable to electrode ion transfer during use.

  13. Evaluation of Alkaline Cleaner Materials

    NASA Technical Reports Server (NTRS)

    Partz, Earl

    1998-01-01

    Alkaline cleaners used to process aluminum substrates have contained chromium as the corrosion inhibitor. Chromium is a hazardous substance whose use and control are described by environmental laws. Replacement materials that have the characteristics of chromated alkaline cleaners need to be found that address both the cleaning requirements and environmental impacts. This report will review environmentally friendly candidates evaluated as non-chromium alkaline cleaner replacements and methods used to compare those candidates one versus another. The report will also list characteristics used to select candidates based on their declared contents. It will also describe and evaluate methods used to discriminate among the large number of prospective candidates.

  14. Improved Electrolytic Hydrogen Peroxide Generator

    NASA Technical Reports Server (NTRS)

    James, Patrick I.

    2005-01-01

    An improved apparatus for the electrolytic generation of hydrogen peroxide dissolved in water has been developed. The apparatus is a prototype of H2O2 generators for the safe and effective sterilization of water, sterilization of equipment in contact with water, and other applications in which there is need for hydrogen peroxide at low concentration as an oxidant. Potential applications for electrolytic H2O2 generators include purification of water for drinking and for use in industrial processes, sanitation for hospitals and biotechnological industries, inhibition and removal of biofouling in heat exchangers, cooling towers, filtration units, and the treatment of wastewater by use of advanced oxidation processes that are promoted by H2O2.

  15. A novel bifunctional hybrid with marine bacterium alkaline phosphatase and Far Eastern holothurian mannan-binding lectin activities.

    PubMed

    Balabanova, Larissa; Golotin, Vasily; Kovalchuk, Svetlana; Bulgakov, Alexander; Likhatskaya, Galina; Son, Oksana; Rasskazov, Valery

    2014-01-01

    A fusion between the genes encoding the marine bacterium Cobetia marina alkaline phosphatase (CmAP) and Far Eastern holothurian Apostichopus japonicus mannan-binding C-type lectin (MBL-AJ) was performed. Expression of the fusion gene in E. coli cells resulted in yield of soluble recombinant chimeric protein CmAP/MBL-AJ with the high alkaline phosphatase activity and specificity of the lectin MBL-AJ. The bifunctional hybrid CmAP/MBL-AJ was produced as a dimer with the molecular mass of 200 kDa. The CmAP/MBL-AJ dimer model showed the two-subunit lectin part that is associated with two molecules of alkaline phosphatase functioning independently from each other. The highly active CmAP label genetically linked to MBL-AJ has advantaged the lectin-binding assay in its sensitivity and time. The double substitution A156N/F159K in the lectin domain of CmAP/MBL-AJ has enhanced its lectin activity by 25 ± 5%. The bifunctional hybrid holothurian's lectin could be promising tool for developing non-invasive methods for biological markers assessment, particularly for improving the MBL-AJ-based method for early detection of a malignant condition in cervical specimens. PMID:25397876

  16. A Novel Bifunctional Hybrid with Marine Bacterium Alkaline Phosphatase and Far Eastern Holothurian Mannan-Binding Lectin Activities

    PubMed Central

    Balabanova, Larissa; Golotin, Vasily; Kovalchuk, Svetlana; Bulgakov, Alexander; Likhatskaya, Galina; Son, Oksana; Rasskazov, Valery

    2014-01-01

    A fusion between the genes encoding the marine bacterium Cobetia marina alkaline phosphatase (CmAP) and Far Eastern holothurian Apostichopus japonicus mannan-binding C-type lectin (MBL-AJ) was performed. Expression of the fusion gene in E. coli cells resulted in yield of soluble recombinant chimeric protein CmAP/MBL-AJ with the high alkaline phosphatase activity and specificity of the lectin MBL-AJ. The bifunctional hybrid CmAP/MBL-AJ was produced as a dimer with the molecular mass of 200 kDa. The CmAP/MBL-AJ dimer model showed the two-subunit lectin part that is associated with two molecules of alkaline phosphatase functioning independently from each other. The highly active CmAP label genetically linked to MBL-AJ has advantaged the lectin-binding assay in its sensitivity and time. The double substitution A156N/F159K in the lectin domain of CmAP/MBL-AJ has enhanced its lectin activity by 25±5%. The bifunctional hybrid holothurian's lectin could be promising tool for developing non-invasive methods for biological markers assessment, particularly for improving the MBL-AJ-based method for early detection of a malignant condition in cervical specimens. PMID:25397876

  17. NASA Hydrogen Peroxide Propulsion Perspective

    NASA Technical Reports Server (NTRS)

    Unger, Ronald; Lyles, Garry M. (Technical Monitor)

    2002-01-01

    This presentation is to provide the current status of NASA's efforts in the development of hydrogen peroxide in both mono-propellant and bi-propellant applications, consistent with the Space Launch Initiative goals of pursuing low toxicity and operationally simpler propellants for application in the architectures being considered for the 2nd Generation Reusable Launch Vehicle, also known as the Space Launch Initiative, or SLI.

  18. Wet peroxide degradation of atrazine.

    PubMed

    Rodríguez, Eva M; Alvarez, Pedro M; Rivas, F Javier; Beltrán, Fernando J

    2004-01-01

    The high temperature (150-200 degrees C), high pressure (3.0-6.0 MPa) degradation of atrazine in aqueous solution has been studied. Under these extreme conditions atrazine steadily hydrolyses in the absence of oxidising agents. Additionally, oxygen partial pressure has been shown not to affect atrazine degradation rates. In no case mineralisation of the parent compound was observed. The addition of the free radical generator hydrogen peroxide to the reaction media significantly enhanced the depletion rate of atrazine. Moreover, partial mineralisation of the organics was observed when hydrogen peroxide was used. Again, oxygen presence did not influence the efficiency of the promoted reaction. Consecutive injections of hydrogen peroxide throughout the reaction period brought the total carbon content conversion to a maximum of 65-70% after 40 min of treatment (suggesting the total conversion of atrazine to cyanuric acid). Toxicity of the effluent measured in a luminometer decreased from 93% up to 23% of inhibition percentage. The process has been simulated by means of a semi-empirical model. PMID:14559259

  19. [Space flight and peroxidative damage].

    PubMed

    Yang, Tang-bin; Zhong, Ping; Qu, Li-na; Yuan, Yan-hong

    2003-12-01

    Space flight is associated with an increase of peroxidative damage after returning to 1 g. The effect is more pronounced after long-duration space flight and can even last for several weeks after landing. In humans there is increased lipid peroxidation in erythrocyte membranes, reduced blood antioxidants, and increased urinary excretion of 8-iso-prostaglandin F2alpha, and 8-oxo-7, 8 dihydro-2 deoxyguanosine. Isoprostane 8-iso-prostaglandin F2alpha and 8-oxo-7, 8 dihydro-2 deoxyguanosine are markers for oxidative damage to lipids and DNA, respectively. The changes are attributed to a combination of energy deficiency that occurs during flight and substrate competition for amino acids occurring between repleted muscle and other tissues during the recovery phase. The observations in humans have been complemented by studies in rodents, which showed increased production of lipid peroxidation products and decreased antioxidant enzyme activity afterflight. The changes in rodents were attributed to the stress associated with re-entry into Earth's gravity. Reducing the imbalance between the production of endogenous oxidant defenses and oxidant production by increasing the supply antioxidants in diet may lessen the severity of the postflight increase in oxidative stress. PMID:15008196

  20. Studies on alkaline serine protease produced by Bacillus clausii GMBE 22.

    PubMed

    Kazan, Dilek; Bal, Hulya; Denizci, Aziz Akin; Ozturk, Nurcin Celik; Ozturk, Hasan Umit; Dilgimen, Aydan Salman; Ozturk, Dilek Coskuner; Erarslan, Altan

    2009-01-01

    An alkali tolerant Bacillus strain having extracellular serine alkaline protease activity was newly isolated from compost and identified as Bacillus clausii GMBE 22. An alkaline protease (AP22) was 4.66-fold purified in 51.5% yield from Bacillus clausii GMBE 22 by ethanol precipitation and DEAE-cellulose anion exchange chromatography. The purified enzyme was identified as serine protease by LC-ESI-MS analysis. Its complete inhibition by phenylmethanesulfonylfluoride (PMSF) also justified that it is a serine alkaline protease. The molecular weight of the enzyme is 25.4 kDa. Optimal temperature and pH values are 60 degrees C and 12.0, respectively. The enzyme showed highest specificity to N-Suc-Ala-Ala-Pro-Phe-pNA. The K(m) and k(cat) values for hydrolysis of this substrate are 0.347 mM and 1141 min(-1) respectively. The enzyme was affected by surface active agents to varying extents. The enzyme is stable for 2 h at 30 degrees C and pH 10.5. AP22 is also stable for 5 days over the pH range 9.0-11.0 at room temperature. AP22 has good pH stability compared with the alkaline proteases belonging to other strains of Bacillus clausii reported in the literature. PMID:19431045

  1. The APS control system network

    SciTech Connect

    Sidorowicz, K.V.; McDowell, W.P.

    1995-12-31

    The APS accelerator control system is a distributed system consisting of operator interfaces, a network, and computer-controlled interfaces to hardware. This implementation of a control system has come to be called the {open_quotes}Standard Model.{close_quotes} The operator interface is a UNDC-based workstation with an X-windows graphical user interface. The workstation may be located at any point on the facility network and maintain full functionality. The function of the network is to provide a generalized communication path between the host computers, operator workstations, input/output crates, and other hardware that comprise the control system. The crate or input/output controller (IOC) provides direct control and input/output interfaces for each accelerator subsystem. The network is an integral part of all modem control systems and network performance will determine many characteristics of a control system. This paper will describe the overall APS network and examine the APS control system network in detail. Metrics are provided on the performance of the system under various conditions.

  2. An AP Calculus Classroom Amusement Park

    ERIC Educational Resources Information Center

    Ferguson, Sarah

    2016-01-01

    Throughout the school year, AP Calculus teachers strive to teach course content comprehensively and swiftly in an effort to finish all required material before the AP Calculus exam. As early May approaches and the AP Calculus test looms, students and teachers nervously complete lessons, assignments, and assessments to ensure student preparation.…

  3. Preparing Students for the AP Psychology Exam

    ERIC Educational Resources Information Center

    Whitlock, Kristin

    2013-01-01

    The Advanced Placement Psychology exam is one of the fastest growing exams offered by the College Board. The average percent of change in the number of students taking this exam over the past five years is 12.4%. With 238,962 students taking the exam in 2013, the AP Psychology exam is the sixth largest exam, surpassing AP Biology and AP World…

  4. AP-1 activity during normal human keratinocyte differentiation: evidence for a cytosolic modulator of AP-1/DNA binding.

    PubMed

    Briata, P; D'Anna, F; Franzi, A T; Gherzi, R

    1993-01-01

    Increased levels of c-fos and c-jun expression have been observed in differentiating epithelial cells. However, no data are available on activator protein 1 (AP-1) activity during keratinocyte differentiation. In this work we investigated c-fos and c-jun gene expression and AP-1-(12-O-tetradecanoylphorbol-13-acetate)-responsive enhancer element (TRE) binding activity during keratinocyte differentiation utilizing both authentic and in culture-reconstituted human epidermis. We demonstrate that: (i) in reconstituted epidermis, non-differentiated and differentiated keratinocytes express equivalent levels of c-Jun, while in reconstituted epidermis permanently grafted onto athymic mice, as well as in authentic epidermis, c-Jun is predominantly expressed in the granular layer of the tissue. Equivalent levels of c-fos expression have been found in all the layers of both reconstituted and authentic epidermis. (ii) Nuclear extracts from cultures enriched in differentiated keratinocytes display an 80-90% reduction of AP-1 activity when compared to extracts from cultures enriched in nondifferentiated cells. (iii) Cytosolic extracts obtained from cultures enriched in differentiated cells reduce, in a concentration-dependent manner, the AP-1 activity present in nuclear extracts of both mammalian and Drosophila cells. (iv) The specific TRE binding activity of a recombinant c-Jun protein is significantly reduced by cytosolic extracts of differentiated keratinocytes, while the specific DNA binding of the purified recombinant human homeoprotein HOX4B is not. (v) The dephosphorylation, by alkaline phosphatase, of cytosolic extracts increases the inhibitory activity already present or makes evident a latent activity. PMID:8416791

  5. Elucidating self-assembly mechanisms of uranyl-peroxide capsules from monomers.

    PubMed

    Liao, Zuolei; Deb, Tapash; Nyman, May

    2014-10-01

    Self-assembly of uranyl peroxide polyoxometalates (POMs) in alkaline peroxide solutions has been known for almost a decade, but in these dynamic solutions that contain high concentrations of base and peroxide the reaction pathway could never be discerned, mixed species are obtained, and reproducibility is sometimes a challenge. Here we elucidate the reaction mechanisms utilizing self-assembly of the U24 cluster, [UO2(O2)(OH)]24(24-), from monomers as a model system. Using Raman as our main spectroscopic probe, we learned that the monomeric species is persistent in water at room temperature indefinitely. However, if a redox-active transition metal catalyst (copper (Cu(2+)) or cobalt (Co(2+))) is added, self-assembly is accelerated in a significant manner, forming U24 peroxide clusters in several hours, which is a good time scale for studying reaction mechanisms. From semiquantitative treatment of the spectroscopic data, we elucidate reaction mechanisms that are consistent with prior structural and computational studies that suggest uranyl peroxide rings templated by alkalis are the building units of clusters. By understanding aqueous speciation and processes, we are moving toward assuming control over cluster self-assembly that has been mastered for decades now in the analogous transition-metal POM systems. PMID:25238533

  6. Establishment of an activated peroxide system for low-temperature cotton bleaching using N-[4-(triethylammoniomethyl)benzoyl]butyrolactam chloride.

    PubMed

    Xu, Changhai; Hinks, David; Sun, Chang; Wei, Qufu

    2015-03-30

    Cotton bleaching is traditionally carried out in strongly alkaline solution of hydrogen peroxide (H2O2) at temperatures close to the boil. Such harsh processing conditions can result in extensive water and energy consumptions as well as severe chemical damage to textiles. In this study, an activated peroxide system was established for low-temperature cotton bleaching by incorporating a bleach activator, namely N-[4-(triethylammoniomethyl)benzoyl]butyrolactam chloride (TBBC) into an aqueous H2O2 solution. Experimental results showed that the TBBC-activated peroxide system exhibited the most effective bleaching performance in a pH range of 6-8 which could be approximated by adding sodium bicarbonate (NaHCO3). The TBBC/H2O2/NaHCO3 system led to rapid bleaching of cotton at a temperature as low as 50°C. In comparison with the hot alkaline peroxide bleaching system, the TBBC/H2O2/NaHCO3 system provided cotton fabric with an equivalent degree of whiteness, higher degree of polymerization, and slightly lower water absorbency. The new activated peroxide system may provide a more environmentally benign approach to cotton bleaching. PMID:25563946

  7. Genome-wide Analysis of AP-3–dependent Protein Transport in Yeast

    PubMed Central

    Anand, Vikram C.; Daboussi, Lydia; Lorenz, Todd C.

    2009-01-01

    The evolutionarily conserved adaptor protein-3 (AP-3) complex mediates cargo-selective transport to lysosomes and lysosome-related organelles. To identify proteins that function in AP-3–mediated transport, we performed a genome-wide screen in Saccharomyces cerevisiae for defects in the vacuolar maturation of alkaline phosphatase (ALP), a cargo of the AP-3 pathway. Forty-nine gene deletion strains were identified that accumulated precursor ALP, many with established defects in vacuolar protein transport. Maturation of a vacuolar membrane protein delivered via a separate, clathrin-dependent pathway, was affected in all strains except those with deletions of YCK3, encoding a vacuolar type I casein kinase; SVP26, encoding an endoplasmic reticulum (ER) export receptor for ALP; and AP-3 subunit genes. Subcellular fractionation and fluorescence microscopy revealed ALP transport defects in yck3Δ cells. Characterization of svp26Δ cells revealed a role for Svp26p in ER export of only a subset of type II membrane proteins. Finally, ALP maturation kinetics in vac8Δ and vac17Δ cells suggests that vacuole inheritance is important for rapid generation of proteolytically active vacuolar compartments in daughter cells. We propose that the cargo-selective nature of the AP-3 pathway in yeast is achieved by AP-3 and Yck3p functioning in concert with machinery shared by other vacuolar transport pathways. PMID:19116312

  8. The alkaline and alkaline-carbonatite magmatism from Southern Brazil

    NASA Astrophysics Data System (ADS)

    Ruberti, E.; Gomes, C. D. B.; Comin-Chiaramonti, P.

    2015-12-01

    Early to Late Cretaceous lasting to Paleocene alkaline magmatism from southern Brazil is found associated with major extensional structural features in and around the Paraná Basin and grouped into various provinces on the basis of several data. Magmatism is variable in size, mode of occurrence and composition. The alkaline rocks are dominantly potassic, a few occurrences showing sodic affinity. The more abundant silicate rocks are evolved undersaturated to saturated in silica syenites, displaying large variation in igneous forms. Less evolved types are restricted to subvolcanic environments and outcrops of effusive suites occur rarely. Cumulatic mafic and ultramafic rock types are very common, particularly in the alkali-carbonatitic complexes. Carbonatite bodies are represented by Ca-carbonatites and Mg-carbonatites and more scarcely by Fe-carbonatites. Available radiometric ages for the alkaline rocks fit on three main chronological groups: around 130 Ma, subcoveal with the Early Cretaceous flood tholeiites of the Paraná Basin, 100-110 Ma and 80-90 Ma (Late Cretaceous). The alkaline magmatism also extends into Paleocene times, as indicated by ages from some volcanic lavas. Geochemically, alkaline potassic and sodic rock types are distinguished by their negative and positive Nb-Ta anomalies, respectively. Negative spikes in Nb-Ta are also a feature common to the associated tholeiitic rocks. Sr-Nd-Pb systematics confirm the contribution of both HIMU and EMI mantle components in the formation of the alkaline rocks. Notably, Early and Late Cretaceous carbonatites have the same isotopic Sr-Nd initial ratios of the associated alkaline rocks. C-O isotopic Sr-Nd isotopic ratios indicate typical mantle signature for some carbonatites and the influence of post-magmatic processes in others. Immiscibility of liquids of phonolitic composition, derived from mafic alkaline parental magmas, has been responsible for the origin of the carbonatites. Close association of alkaline

  9. Alkaline Phosphatase Protects Lipopolysaccharide-Induced Early Pregnancy Defects in Mice

    PubMed Central

    Lei, Wei; Ni, Hua; Herington, Jennifer; Reese, Jeff; Paria, Bibhash C.

    2015-01-01

    Excessive cytokine inflammatory response due to chronic or superphysiological level of microbial infection during pregnancy leads to pregnancy complications such as early pregnancy defects/loss and preterm birth. Bacterial toxin lipopolysaccharide (LPS), long recognized as a potent proinflammatory mediator, has been identified as a risk factor for pregnancy complications. Alkaline phosphatase (AP) isozymes have been shown to detoxify LPS by dephosphorylation. In this study, we examined the role of alkaline phosphatase (AP) in mitigating LPS-induced early pregnancy complications in mice. We found that 1) the uterus prior to implantation and implantation sites following embryo implantation produce LPS recognition and dephosphorylation molecules TLR4 and tissue non-specific AP (TNAP) isozyme, respectively; 2) uterine TNAP isozyme dephosphorylates LPS at its sites of production; 3) while LPS administration following embryo implantation elicits proinflammatory cytokine mRNA levels at the embryo implantation sites (EISs) and causes early pregnancy loss, dephosphorylated LPS neither triggers proinflammatory cytokine mRNA levels at the EISs nor induces pregnancy complications; 4) AP isozyme supplementation to accelerate LPS detoxification attenuates LPS-induced pregnancy complications following embryo implantation. These findings suggest that a LPS dephosphorylation strategy using AP isozyme may have a unique therapeutic potential to mitigate LPS- or Gram-negative bacteria-induced pregnancy complications in at-risk women. PMID:25910276

  10. Alkaline phosphatase in osteoblasts is down-regulated by pulsatile fluid flow

    NASA Technical Reports Server (NTRS)

    Hillsley, M. V.; Frangos, J. A.

    1997-01-01

    It is our hypothesis that interstitial fluid flow plays a role in the bone remodeling response to mechanical loading. The fluid flow-induced expression of three proteins (collagen, osteopontin, and alkaline phosphatase) involved in bone remodeling was investigated. Rat calvarial osteoblasts subjected to pulsatile fluid flow at an average shear stress of 5 dyne/cm2 showed decreased alkaline phosphatase (AP) mRNA expression after only 1 hour of flow. After 3 hours of flow, AP mRNA levels had decreased to 30% of stationary control levels and remained at this level for an additional 5 hours of flow. Steady flow (4 dyne/cm2 fluid shear stress), in contrast, resulted in a delayed and less dramatic decrease in AP mRNA expression to 63% of control levels after 8 hours of flow. The reduced AP mRNA expression under pulsatile flow conditions was followed by reduced AP enzyme activity after 24 hours. No changes in collagen or osteopontin mRNA expression were detected over 8 hours of pulsatile flow. This is the first time fluid flow has been shown to affect gene expression in osteoblasts.

  11. Tungstate as a Transition State Analog for Catalysis by Alkaline Phosphatase.

    PubMed

    Peck, Ariana; Sunden, Fanny; Andrews, Logan D; Pande, Vijay S; Herschlag, Daniel

    2016-07-01

    The catalytic mechanisms underlying Escherichia coli alkaline phosphatase's (AP) remarkable rate enhancement have been probed extensively. Past work indicated that whereas the serine nucleophile (Ser102) electrostatically repels the product phosphate, another oxyanion, tungstate, binds more strongly in the presence of Ser102. These results predict a covalent bond between the serine nucleophile and tungstate, a model that we test herein. The crystal structure of tungstate-bound alkaline phosphatase provides evidence for a covalent adduct model and further shows that the ligand adopts trigonal bipyramidal geometry, which is infrequently observed for tungstate in small molecules and other active sites but mirrors the geometry of the presumed phosphoryl transfer transition state. The AP active site is known to stabilize another oxyanion, vanadate, in trigonal bipyramidal geometry, but the extent to which binding of either ligand reproduces the energetics of the transition state cannot be deduced from structural inspection alone. To test for transition state analog behavior, we determined the relationship between catalytic activity and affinity for tungstate and vanadate for a series of 20 AP variants. Affinity and activity were highly correlated for tungstate (r(2) = 0.89) but not vanadate (r(2) = 0.23), indicating that the tungstate•AP complex may better mimic this enzyme's transition state properties. The results herein suggest that tungstate will be a valuable tool for further dissecting AP catalysis and may prove helpful in mechanistic studies of other phosphoryl transfer enzymes. PMID:27189921

  12. AP reclamation and reuse in RSRM propellant

    NASA Technical Reports Server (NTRS)

    Miks, Kathryn F.; Harris, Stacey A.

    1995-01-01

    A solid propellant ingredient reclamation pilot plant has been evaluated at the Strategic Operations of Thiokol Corporation, located in Brigham City, Utah. The plant produces AP wet cake (95 percent AP, 5 percent water) for recycling at AP vendors. AP has been obtained from two standard propellant binder systems (PBAN and HTPB). Analytical work conducted at Thiokol indicates that the vendor-recrystallized AP meets Space Shuttle propellant specification requirements. Thiokol has processed 1-, 5-, and 600-gallon propellant mixes with the recrystallized AP. Processing, cast, cure, ballistic, mechanical, and safety properties have been evaluated. Phillips Laboratory static-test-fired 70-pound and 800-pound BATES motors. The data indicate that propellant processed with reclaimed AP has nominal properties.

  13. Structural characteristics of alkaline phosphatase from the moderately halophilic bacterium Halomonas sp. 593

    PubMed Central

    Arai, Shigeki; Yonezawa, Yasushi; Ishibashi, Matsujiro; Matsumoto, Fumiko; Adachi, Motoyasu; Tamada, Taro; Tokunaga, Hiroko; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2014-01-01

    Alkaline phosphatase (AP) from the moderate halophilic bacterium Halomonas sp. 593 (HaAP) catalyzes the hydrolysis of phosphomonoesters over a wide salt-concentration range (1–4 M NaCl). In order to clarify the structural basis of its halophilic characteristics and its wide-range adaptation to salt concentration, the tertiary structure of HaAP was determined by X-ray crystallography to 2.1 Å resolution. The unit cell of HaAP contained one dimer unit corresponding to the biological unit. The monomer structure of HaAP contains a domain comprised of an 11-stranded β-sheet core with 19 surrounding α-helices similar to those of APs from other species, and a unique ‘crown’ domain containing an extended ‘arm’ structure that participates in formation of a hydrophobic cluster at the entrance to the substrate-binding site. The HaAP structure also displays a unique distribution of negatively charged residues and hydrophobic residues in comparison to other known AP structures. AP from Vibrio sp. G15-21 (VAP; a slight halophile) has the highest similarity in sequence (70.0% identity) and structure (Cα r.m.s.d. of 0.82 Å for the monomer) to HaAP. The surface of the HaAP dimer is substantially more acidic than that of the VAP dimer (144 exposed Asp/Glu residues versus 114, respectively), and thus may enable the solubility of HaAP under high-salt conditions. Conversely, the monomer unit of HaAP formed a substantially larger hydrophobic interior comprising 329 C atoms from completely buried residues, whereas that of VAP comprised 264 C atoms, which may maintain the stability of HaAP under low-salt conditions. These characteristics of HaAP may be responsible for its unique functional adaptation permitting activity over a wide range of salt concentrations. PMID:24598750

  14. Tempol inhibits neutrophil and hydrogen peroxide-mediated DNA damage.

    PubMed

    Hahn, S M; Mitchell, J B; Shacter, E

    1997-01-01

    Inflammatory conditions characterized by neutrophil activation are associated with a variety of chronic diseases. Reactive oxygen species are produced by activated neutrophils and produce DNA damage which may lead to tissue damage. Previous studies have shown that activated murine neutrophils induce DNA strand breaks in a target plasmacytoma cell, RIMPC 2394. We studied the effect of a water soluble nitroxide anti-oxidant, Tempol, on murine neutrophil induction of DNA strand breaks in this system. Murine neutrophils were isolated from the peritoneal cavity of BALB/cAn mice after an i.p. injection of pristane oil. Neutrophils were activated by the phorbol ester PMA and co-incubated with RIMPC 2394 cells. Control alkaline elution studies revealed progressive DNA strand breaks in RIMPC cells with time. The addition of Tempol to the incubation mixture prevented DNA damage in a dose dependent fashion. Five mM Tempol provided complete protection. Tempol protection against DNA strand breaks was similar for both stimulated neutrophils and exogenously added hydrogen peroxide. Measurement of hydrogen peroxide produced by stimulated neutrophils demonstrated that Tempol did not decrease hydrogen peroxide concentration. Oxidation of reduced metals, thereby interfering with the production of hydroxyl radical, is the most likely mechanism of nitroxide protection, although superoxide dismutase (SOD) like activity and scavenging of carbon-based free radicals may also account for a portion of the observed protection. The anti-oxidant activity of Tempol inhibited DNA damage by activated neutrophils. The nitroxides as a class of compounds may have a role in the investigation and modification of inflammatory conditions. PMID:9378367

  15. Coating for components requiring hydrogen peroxide compatibility

    NASA Technical Reports Server (NTRS)

    Yousefiani, Ali (Inventor)

    2010-01-01

    The present invention provides a heretofore-unknown use for zirconium nitride as a hydrogen peroxide compatible protective coating that was discovered to be useful to protect components that catalyze the decomposition of hydrogen peroxide or corrode when exposed to hydrogen peroxide. A zirconium nitride coating of the invention may be applied to a variety of substrates (e.g., metals) using art-recognized techniques, such as plasma vapor deposition. The present invention further provides components and articles of manufacture having hydrogen peroxide compatibility, particularly components for use in aerospace and industrial manufacturing applications. The zirconium nitride barrier coating of the invention provides protection from corrosion by reaction with hydrogen peroxide, as well as prevention of hydrogen peroxide decomposition.

  16. Lipid Peroxidation in Higher Plants 1

    PubMed Central

    Schmidt, Arno; Kunert, Karl Josef

    1986-01-01

    To study the role of glutathione reductase in lipid peroxidation, bean leaves (Phaseolus vulgaris) cv Fori were treated with the herbicide acifluorfen-sodium (sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid). Acifluorfen is a potent inducer of lipid peroxidation. In beans, decrease of acid-soluble SH-compounds and lipid peroxidation, measured as ethane evolution, were the toxic events after treatment of leaves with acifluorfen. As a primary response to peroxidation, increased production of antioxidants, such as vitamin C and glutathione, was found. This was followed by elevation of glutathione reductase activity. Enhanced activity of the enzyme prevented both further decline of acid-soluble SH-compounds and lipid peroxidation. Increased production of antioxidants and elevated activity of antioxidative enzymes, like glutathione reductase, seem to be a general strategy to limit toxic peroxidation in plants. PMID:16665095

  17. EQCM analysis of titanium corrosion in peroxide- or fluoride-containing solutions.

    PubMed

    Hattori, Masayuki; Oda, Yutaka

    2013-01-01

    Although offering superior resistance to corrosion, titanium is unable to withstand discoloration with exposure to peroxide or fluoride. The mechanism of this discoloration, however, remains to be clarified. The purpose of this study was to investigate the mechanism underlying discoloration of titanium with immersion in peroxide- or fluoride-containing solutions based on electrochemical quartz crystal microbalance (EQCM) analysis. A 9-MHz titanium-deposited quartz crystal was used as for the electrodes. Four test solutions were prepared for immersion of the electrodes: 154 mM (0.9%) NaCl; 150 mM H2O2+154 mM NaCl (pH=4 by addition of lactic acid); 150 mM H2O2+154 mM NaCl (pH=8 by addition of sodium hydroxide solution); and 48 mM (0.2%) NaF+154 mM NaCl (pH=5.0 by addition of lactic acid). A WinEchem electrochemistry software-controlled quartz crystal analyzer (QCA922) and the Potentiostat/Galvanostat (Princeton Applied Research) on Windows XP were used to measure concurrently the resonance frequency and potential of the electrodes. The EQCM data differed among solutions. In the acidulated fluoride-containing solution, the electrode showed lower open circuit potential and a gradual increase in electrode frequency, indicating a loss of mass by titanium dissolution. In the peroxide-containing solution, although open circuit potential showed no marked difference, electrode frequency showed a gentle decrease in acidic solution, indicating a gain in mass by oxidation; but an increase in alkaline solution, indicating a loss of mass by dissolution. These results confirmed that exposure to acidulated fluoride- or alkaline peroxide-containing solutions causes dissolution-induced discoloration, while that to acidulated peroxide-containing solutions resulted in the formation of an oxide film together with discoloration. PMID:24334626

  18. Hydrogen peroxide, from Wieland to Sies.

    PubMed

    Koppenol, Willem H

    2016-04-01

    A history of the formation of hydrogen peroxide in vivo is presented, starting with the discovery of catalase. The first hypothesis was formulated by Heinrich Wieland, who assumed that dioxygen reacted directly with organic molecules. This view was strongly criticised by Otto Warburg, Helmut Sies' academic grandfather. The involvement of hydrogen peroxide in physiological processes was investigated by Theodor Bücher, the "Doktorvater" of Helmut. Helmut's research made it possible to quantitate hydrogen peroxide in tissues. PMID:27095207

  19. Hydrogen peroxide on the surface of Europa

    USGS Publications Warehouse

    Carlson, R.W.; Anderson, M.S.; Johnson, R.E.; Smythe, W.D.; Hendrix, A.R.; Barth, C.A.; Soderblom, L.A.; Hansen, G.B.; McCord, T.B.; Dalton, J.B.; Clark, R.N.; Shirley, J.H.; Ocampo, A.C.; Matson, D.L.

    1999-01-01

    Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.

  20. High Temperature Decomposition of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydropemxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  1. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2005-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  2. PEROXIDE PROCESS FOR SEPARATION OF RADIOACTIVE MATERIALS

    DOEpatents

    Seaborg, G.T.; Perlman, I.

    1958-09-16

    reduced state, from hexavalent uranium. It consists in treating an aqueous solution containing such uranium and plutonium ions with sulfate ions in order to form a soluble uranium sulfate complex and then treating the solution with a soluble thorium compound and a soluble peroxide compound in order to ferm a thorium peroxide carrier precipitate which carries down with it the plutonium peroxide present. During this treatment the pH of the solution must be maintained between 2 and 3.

  3. Hydrogen peroxide on the surface of Europa.

    PubMed

    Carlson, R W; Anderson, M S; Johnson, R E; Smythe, W D; Hendrix, A R; Barth, C A; Soderblom, L A; Hansen, G B; McCord, T B; Dalton, J B; Clark, R N; Shirley, J H; Ocampo, A C; Matson, D L

    1999-03-26

    Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis. PMID:10092224

  4. Detection of endogenous alkaline phosphatase activity in intact cells by flow cytometry using the fluorogenic ELF-97 phosphatase substrate

    NASA Technical Reports Server (NTRS)

    Telford, W. G.; Cox, W. G.; Stiner, D.; Singer, V. L.; Doty, S. B.

    1999-01-01

    BACKGROUND: The alkaline phosphatase (AP) substrate 2-(5'-chloro-2'-phosphoryloxyphenyl)-6-chloro-4-(3H)-quinazolinone (ELF((R))-97 for enzyme-labeled fluorescence) has been found useful for the histochemical detection of endogenous AP activity and AP-tagged proteins and oligonucleotide probes. In this study, we evaluated its effectiveness at detecting endogenous AP activity by flow cytometry. METHODS: The ELF-97 phosphatase substrate was used to detect endogenous AP activity in UMR-106 rat osteosarcoma cells and primary cultures of chick chondrocytes. Cells were labeled with the ELF-97 reagent and analyzed by flow cytometry using an argon ultraviolet (UV) laser. For comparison purposes, cells were also assayed for AP using a Fast Red Violet LB azo dye assay previously described for use in detecting AP activity by flow cytometry. RESULTS: The ELF-97 phosphatase substrate effectively detected endogenous AP activity in UMR-106 cells, with over 95% of the resulting fluorescent signal resulting from AP-specific activity (as determined by levamisole inhibition of AP activity). In contrast, less than 70% of the fluorescent signal from the Fast Red Violet LB (FRV) assay was AP-dependent, reflecting the high intrinsic fluorescence of the unreacted components. The ELF-97 phosphatase assay was also able to detect very low AP activity in chick chondrocytes that was undetectable by the azo dye method. CONCLUSIONS: The ELF-97 phosphatase assay was able to detect endogenous AP activity in fixed mammalian and avian cells by flow cytometry with superior sensitivity to previously described assays. This work also shows the applicability of ELF-97 to flow cytometry, supplementing its previously demonstrated histochemical applications. Copyright 1999 Wiley-Liss, Inc.

  5. High Sequence Variability, Diverse Subcellular Localizations, and Ecological Implications of Alkaline Phosphatase in Dinoflagellates and Other Eukaryotic Phytoplankton

    PubMed Central

    Lin, Xin; Zhang, Huan; Cui, Yudong; Lin, Senjie

    2012-01-01

    Alkaline phosphatase (AP) is a key enzyme for phytoplankton to utilize dissolved organic phosphorus (DOP) when dissolved inorganic phosphorus is limited. While three major types of AP and their correspondingly diverse subcellular localization have been recognized in bacteria, little is known about AP in eukaryotic phytoplankton such as dinoflagellates. Here, we isolated a full-length AP cDNA from a latest-diverging dinoflagellate genus Alexandrium, and conducted comparative analyses with homologs from a relatively basal (Amphidinium carterae) and late-diverging (Karenia brevis) lineage of dinoflagellates as well as other eukaryotic algae. New data and previous studies indicate that AP is common in dinoflagellates and most other major eukaryotic groups of phytoplankton. AP sequences are more variable than many other genes studied in dinoflagellates, and are divergent among different eukaryotic phytoplankton lineages. Sequence comparison to the other characterized APs suggests that dinoflagellates and some other eukaryotic phytoplankton possess the putative AP as phoA type, but some other eukaryotic phytoplankton seem to have other types. Phylogenetic analyses based on AP amino acid sequences indicated that the “red-type” eukaryotic lineages formed a monophyletic group, suggesting a common origin of their APs. As different amino acid sequences have been found to predictably determine different spatial distribution in the cells, which may facilitate access to different pools of DOP, existing computational models were adopted to predict the subcellular localizations of putative AP in the three dinoflagellates and other eukaryotic phytoplankton. Results showed different subcellular localizations of APs in different dinoflagellates and other lineages. The linkage between AP sequence divergence, subcellular localization, and ecological niche differentiation requires rigorous experimental verification, and this study now provides a framework for such a future effort

  6. Oxidative cleavage of cycloalkanones by hydrogen peroxide

    SciTech Connect

    Starostin, E.K.; Aleksandrov, A.V.; Nikishin, G.I.

    1986-07-10

    The authors have studied the reaction of cyclopentanone, cyclohexanone, cycloheptanone, and cyclododecanone with aqueous hydrogen peroxide over the temperature range 110-150/sup 0/C. The effects of temperature, hydrogen peroxide concentration, and the molar proportions of the reagents on the composition and yields of the products have been examined in the case of cyclohexanone. Oxidation of cyclohexanone by aqueous hydrogen peroxide at 110-150/sup 0/C gives 1,10-decanedicarboxylic acid and hexanoic acid as the principal products. Cyclopentanone and cycloheptanone react with hydrogen peroxide similarly to cyclohexanone, giving sebacic and pentanoic acids, and 1,12-dodecanedicarboxylic acids, respectively.

  7. Pyridine and pyrimidine analogs of acetaminophen as inhibitors of lipid peroxidation and cyclooxygenase and lipoxygenase catalysis†

    PubMed Central

    Nam, Tae-gyu; Nara, Susheel J.; Zagol-Ikapitte, Irène; Cooper, Thomas; Valgimigli, Luca; Oates, John A.; Porter, Ned A.; Boutaud, Olivier; Pratt, Derek A.

    2010-01-01

    Herein we report an investigation of the efficacy of pyridine and pyrimidine analogs of acetaminophen (ApAP) as peroxyl radical-trapping antioxidants and inhibitors of enzyme-catalyzed lipid peroxidation by cyclooxygenases (COX) and lipoxygenases (LOX). In inhibited autoxidations we find that ApAP, the common analgesic and antipyretic agent, is a very good antioxidant with a rate constant for reaction with peroxyl radicals (kinh = 5 × 105 M−1 s−1) that is higher than many widely-used phenolic antioxidants, such as the ubiquitous butylated hydroxytoluene (BHT). This reactivity is reduced substantially upon incorporation of nitrogen into the phenolic ring, owing to an increase in the O–H bond dissociation enthalpy of pyridinols and pyrimidinols with respect to phenols. Incorporation of nitrogen into the phenolic ring of ApAP was also found to decrease its efficacy as an inhibitor of prostaglandin biosynthesis by ovine COX-1 (oCOX-1). This is explained on the basis of an increase in its oxidation potential and its reduced reactivity as a reducing co-substrate of the peroxidase protoporphyrin. In contrast, the efficacy of ApAP as an inhibitor of lipid hydroperoxide biosynthesis by soybean LOX-1 (sLOX-1) increased upon incorporation of nitrogen into the ring, suggesting a different mechanism of inhibition dependent on the acidity of the phenolic O–H which may involve chelation of the catalytic non-heme iron atom. The greater stability of the 3-pyridinols and 5-pyrimidinols to air oxidation as compared to phenols allowed us to evaluate some electron-rich pyridinols and pyrimidinols as inhibitors of oCOX-1 and sLOX-1. While the pyridinols had the best combination of activities as antioxidants and inhibitors of oCOX-1 and sLOX-1, they were found to be more toxic than ApAP in preliminary assays in human hepatocellular carcinoma (HepG2) cell culture. The pyrimidinols, however, were up to 17-fold more reactive to peroxyl radicals and up to 25-fold better inhibitors

  8. APS high heat load monochromator

    SciTech Connect

    Lee, W.K.; Mills, D.

    1993-02-01

    This document contains the design specifications of the APS high heat load (HHL) monochromator and associated accessories as of February 1993. It should be noted that work is continuing on many parts of the monochromator including the mechanical design, crystal cooling designs, etc. Where appropriate, we have tried to add supporting documentation, references to published papers, and calculations from which we based our decisions. The underlying philosophy behind performance specifications of this monochromator was to fabricate a device that would be useful to as many APS users as possible, that is, the design should be as generic as possible. In other words, we believe that this design will be capable of operating on both bending magnet and ID beamlines (with the appropriate changes to the cooling and crystals) with both flat and inclined crystal geometries and with a variety of coolants. It was strongly felt that this monochromator should have good energy scanning capabilities over the classical energy range of about 4 to 20 keywith Si (111) crystals. For this reason, a design incorporating one rotation stage to drive both the first and second crystals was considered most promising. Separate rotary stages for the first and second crystals can sometimes provide more flexibility in their capacities to carry heavy loads (for heavily cooled first crystals or sagittal benders of second crystals), but their tuning capabilities were considered inferior to the single axis approach.

  9. Diarylsulfonamides and their bioisosteres as dual inhibitors of alkaline phosphatase and carbonic anhydrase: Structure activity relationship and molecular modelling studies.

    PubMed

    Al-Rashida, Mariya; Ejaz, Syeda Abida; Ali, Sharafat; Shaukat, Aisha; Hamayoun, Mehwish; Ahmed, Maqsood; Iqbal, Jamshed

    2015-05-15

    The effect of bioisosteric replacement of carboxamide linking group with sulfonamide linking group, on alkaline phosphatase (AP) and carbonic anhydrase (CA) inhibition activity of aromatic benzenesulfonamides was investigated. A series of carboxamide linked aromatic benzenesulfonamides 1a-1c, 2a-2d and their sulfonamide linked bioisosteres 3a-3d, 4a-4d was synthesized and evaluated for inhibitory activity against bovine tissue non-specific alkaline phosphatase (TNAP), intestinal alkaline phosphatase (IAP) and bCA II. A significant increase in CA inhibition activity was observed upon bioisosteric replacement of carboxamide linking group with a sulfonamide group. Some of these compounds were identified as highly potent and selective AP inhibitors. Compounds 1b, 2b, 3d, 4d 5b and 5c were found to be selective bTNAP inhibitors, whereas compounds 1a, 1c, 2a, 2c, 2d, 3a, 3c, 4a, 4b, 4c, 5a were found to be selective bIAP inhibitors. For most active AP inhibitor 3b, detailed kinetic studies indicated a competitive mode of inhibition against tissue non-specific alkaline phosphatase (TNAP) and non-competitive mode of inhibition against intestinal alkaline phosphatase (IAP). Molecular docking studies were carried out to rationalize important binding site interactions. PMID:25865133

  10. Alkaline Phosphatase-Positive Immortal Mouse Embryo Fibroblasts Are Cells in a Transitional Reprogramming State Induced to Face Environmental Stresses

    PubMed Central

    Evangelista, Monica; Baroudi, Mariama El; Rizzo, Milena; Tuccoli, Andrea; Poliseno, Laura; Pellegrini, Marco; Rainaldi, Giuseppe

    2015-01-01

    In this study, we report that immortal mouse embryonic fibroblasts (I-MEFs) have a baseline level of cells positive for alkaline phosphatase (AP+) staining. Environmental stresses, including long-lasting growth in the absence of expansion and treatment with drugs, enhance the frequency of AP+ I-MEFs. By adapting fast red AP staining to the sorting procedure, we separated AP+ and AP− I-MEFs and demonstrated that the differentially expressed genes are consistent with a reprogrammed phenotype. In particular, we found that sestrin 1 is upregulated in AP+ I-MEFs. We focused on this gene and demonstrated that increased sestrin 1 expression is accompanied by the growth of I-MEFs in the absence of expansion and occurs before the formation of AP+ I-MEFs. Together with sestrin 1 upregulation, we found that AP+ I-MEFs accumulated in the G1 phase of the cell cycle, suggesting that the two events are causally related. Accordingly, we found that silencing sestrin 1 expression reduced the frequency and G1 accumulation of AP+ I-MEFs. Taken together, our data suggested that I-MEFs stressed by environmental changes acquire the AP+ phenotype and achieve a quiescent state characterized by a new transcriptional network. PMID:26740745

  11. Tank 241-AP-106, Grab samples, 6AP-98-1, 6AP-98-2 and 6AP-98-3 Analytical results for the final report

    SciTech Connect

    FULLER, R.K.

    1999-02-23

    This document is the final report for tank 241-AP-106 grab samples. Three grab samples 6AP-98-1, 6AP-98-2 and 6AP-98-3 were taken from riser 1 of tank 241-AP-106 on May 28, 1998 and received by the 222-S Laboratory on May 28, 1998. Analyses were performed in accordance with the ''Compatability Grab Sampling and Analysis Plan'' (TSAP) (Sasaki, 1998) and the ''Data Quality Objectives for Tank Farms Waste Compatability Program (DQO). The analytical results are presented in the data summary report. No notification limits were exceeded. The request for sample analysis received for AP-106 indicated that the samples were polychlorinated biphenyl (PCB) suspects. The results of this analysis indicated that no PCBs were present at the Toxic Substance Control Act (TSCA) regulated limit of 50 ppm. The results and raw data for the PCB analysis are included in this document.

  12. Purification and characterisation of an alkaline protease used in tannery industry from Bacillus licheniformis.

    PubMed

    Tang, Xue-Ming; Lakay, F M; Shen, Wei; Shao, Wei-Lan; Fang, Hui-Ying; Prior, B A; Wang, Zheng-Xiang; Zhuge, Jian

    2004-09-01

    An extracellular alkaline protease produced by Bacillus licheniformis AP-1 was purified 76-fold, yielding a single 28 kDa band on SDS-PAGE. It was optimally active at pH 11 and at 60 degrees C (assayed over 10 min). The protease was completely inhibited by phenylmethylsulfonyl fluoride and diodopropyl fluorophosphate, with little increase upon Ca2+ and Mg2+ addition. PMID:15604774

  13. Hydrogen peroxide as a greenhouse soil amendment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are anecdotal reports that hydrogen peroxide provides growth benefits beyond controlling plant infection and plant stress. The objective of this research was to determine the effect of soil applications of hydrogen peroxide solutions on plant growth and flowering. Nasturtium (Tropaeolum maju...

  14. Fundamentals of ISCO Using Hydrogen Peroxide

    EPA Science Inventory

    Hydrogen peroxide is a common oxidant that has been applied extensively with in situ chemical oxidation (ISCO). Because of its widespread use in this and other fields, it has been extensively researched. This research has revealed that hydrogen peroxide has very complex chemistry...

  15. 21 CFR 172.802 - Acetone peroxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... proportions of higher polymers, manufactured by reaction of hydrogen peroxide and acetone. (b) The additive may be mixed with an edible carrier to give a concentration of: (1) 3 grams to 10 grams of hydrogen...; or (2) approximately 0.75 gram of hydrogen peroxide equivalent per 100 grams of the additive,...

  16. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  17. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1150 Hydrogen peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen...

  18. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  19. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1150 Hydrogen peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen...

  20. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1150 Hydrogen peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen...

  1. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  2. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  3. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1150 Hydrogen peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen...

  4. [Advances in peroxide-based decontaminating technologies].

    PubMed

    Xi, Hai-ling; Zhao, San-ping; Zhou, Wen

    2013-05-01

    With the boosting demand for eco-friendly decontaminants, great achievements in peroxide-based decontaminating technologies have been made in recent years. These technologies have been applied in countering chemical/biological terrorist attacks, dealing with chemical/biological disasters and destructing environmental pollutants. Recent research advances in alpha-nucleophilic/oxidative reaction mechanisms of peroxide-based decontamination against chemical warfare agents were reviewed, and some classical peroxide-based decontaminants such as aqueous decontaminating solution, decontaminating foam, decontaminating emulsions, decontaminating gels, decontaminating vapors, and some newly developed decontaminating media (e.g., peroxide-based self-decontaminating materials and heterogeneous nano-catalytic decontamination systems) were introduced. However, currently available peroxide-based decontaminants still have some deficiencies. For example, their decontamination efficiencies are not as high as those of chlorine-containing decontaminants, and some peroxide-based decontaminants show relatively poor effect against certain agents. More study on the mechanisms of peroxide-based decontaminants and the interfacial interactions in heterogeneous decontamination media is suggested. New catalysts, multifunctional surfactants, self-decontaminating materials and corrosion preventing technologies should be developed before peroxide-based decontaminants really become true "green" decontaminants. PMID:23914512

  5. Molecular Association and Structure of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Giguere, Paul A.

    1983-01-01

    The statement is sometimes made in textbooks that liquid hydrogen peroxide is more strongly associated than water, evidenced by its higher boiling point and greater heat of vaporization. Discusses these and an additional factor (the nearly double molecular mass of the peroxide), focusing on hydrogen bonds and structure of the molecule. (JN)

  6. 21 CFR 529.1150 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrogen peroxide. 529.1150 Section 529.1150 Food... DRUGS, FEEDS, AND RELATED PRODUCTS CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS § 529.1150 Hydrogen peroxide. (a) Specifications. Each milliliter of solution contains 396.1 milligrams (mg) hydrogen...

  7. 7 CFR 58.431 - Hydrogen peroxide.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hydrogen peroxide. 58.431 Section 58.431 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.431 Hydrogen peroxide. The solution shall comply with the specification of the...

  8. Problem of the lithium peroxide thermal stability

    NASA Astrophysics Data System (ADS)

    Nefedov, R. A.; Ferapontov, Yu A.; Kozlova, N. P.

    2016-01-01

    The behavior of lithium peroxide and lithium peroxide monohydrate samples under heating in atmospheric air was studied by the method of thermogravimetric analysis (TGA) and differential thermal analysis (DTA). It was found that in the temperature range of 32°C to 82°C the interaction of lithium peroxides and steam with the formation of lithium peroxide monohydrate occurs, which was confirmed chemically and by X-ray Single-qualitative analysis. It was experimentally found that lithium peroxide starts to decompose into the lithium oxide and oxygen in the temperature range of 340 ÷ 348°C. It was established that the resulting thermal decomposition of lithium oxide, lithium peroxide at the temperature of 422°C melts with lithium carbonate eutecticly. The manifestation of polymorphism was not marked(seen or noticed) under the heating of studied samples of lithium peroxide and lithium peroxide monohydrate in the temperature range of 25°C ÷ 34°C.

  9. Simple, field portable colorimetric detection device for organic peroxides and hydrogen peroxide

    DOEpatents

    Pagoria, Philip F.; Mitchell, Alexander R.; Whipple, Richard E.; Carman, M. Leslie; Reynolds, John G.; Nunes, Peter; Shields, Sharon J.

    2010-11-09

    A simple and effective system for the colorimetric determination of organic peroxides and hydrogen peroxide. A peroxide pen utilizing a swipe material attached to a polyethylene tube contains two crushable vials. The two crushable vials contain a colorimetric reagent separated into dry ingredients and liquid ingredients. After swiping a suspected substance or surface the vials are broken, the reagent is mixed thoroughly and the reagent is allowed to wick into the swipe material. The presence of organic peroxides or hydrogen peroxide is confirmed by a deep blue color.

  10. RECLAMATION OF ALKALINE ASH PILES

    EPA Science Inventory

    The objective of the study was to develop methods for reclaiming ash disposal piles for the ultimate use as agricultural or forest lands. The ashes studied were strongly alkaline and contained considerable amounts of salts and toxic boron. The ashes were produced from burning bit...

  11. Chemiluminescence behavior of CdTe-hydrogen peroxide enhanced by sodium hypochlorite and sensitized sensing of estrogens

    NASA Astrophysics Data System (ADS)

    Ling, Bo; Bi, Jianhong; Pi, Zongxin; Dong, Huaze; Dong, Ling

    2014-05-01

    It has been found that sodium hypochlorite enhanced the chemiluminescence (CL) of the CdTe nanocrystal (NC)-hydrogen peroxide system and that estrogens inhibited these CL signals in alkaline solution. CL spectra were used to investigate the mechanism of the CL enhancement. On the basis of the inhibition, a flow-injection CL method has been established for determination of three natural estrogens.

  12. Transient removal of alkaline zones after excitation of Chara cells is associated with inactivation of high conductance in the plasmalemma

    PubMed Central

    2009-01-01

    The action potential (AP) of excitable plant cells is a multifunctional physiological signal. Its generation in characean algae suppresses the pH banding for 15–30 min and enhances the heterogeneity of spatial distribution of photosynthetic activity. This suppression is largely due to the cessation of H+ influx (OH− efflux) in the alkaline cell regions. Measurements of local pH and membrane conductance in individual space-clamped alkaline zones (small cell areas bathed in an isolated pool of external medium) showed that the AP generation is followed by the transient disappearance of alkaline zone in parallel with a large decrease in membrane conductance. These changes, specific to alkaline zones, were only observed under continuous illumination following a relaxation period of at least 15 min after previous excitation. The excitation of dark-adapted cells produced no conductance changes in the post-excitation period. The results indicate that the origin of alkaline zones in characean cells is not due to operation of electroneutral H+/HCO3− symport or OH−/HCO3− antiport. It is concluded that the membrane excitation is associated with inactivation of plasmalemma high conductance in the alkaline cell regions. PMID:19820298

  13. Rearrangements of organic peroxides and related processes

    PubMed Central

    Yaremenko, Ivan A; Vil’, Vera A; Demchuk, Dmitry V

    2016-01-01

    Summary This review is the first to collate and summarize main data on named and unnamed rearrangement reactions of peroxides. It should be noted, that in the chemistry of peroxides two types of processes are considered under the term rearrangements. These are conventional rearrangements occurring with the retention of the molecular weight and transformations of one of the peroxide moieties after O–O-bond cleavage. Detailed information about the Baeyer−Villiger, Criegee, Hock, Kornblum−DeLaMare, Dakin, Elbs, Schenck, Smith, Wieland, and Story reactions is given. Unnamed rearrangements of organic peroxides and related processes are also analyzed. The rearrangements and related processes of important natural and synthetic peroxides are discussed separately. PMID:27559418

  14. Vapor Hydrogen Peroxide Sterilization Certification

    NASA Astrophysics Data System (ADS)

    Chen, Fei; Chung, Shirley; Barengoltz, Jack

    For interplanetary missions landing on a planet of potential biological interest, United States NASA planetary protection currently requires that the flight system must be assembled, tested and ultimately launched with the intent of minimizing the bioload taken to and deposited on the planet. Currently the only NASA approved microbial reduction method is dry heat sterilization process. However, with utilization of such elements as highly sophisticated electronics and sensors in modern spacecraft, this process presents significant materials challenges and is thus an undesirable bioburden reduction method to design engineers. The objective of this work is to introduce vapor hydrogen peroxide (VHP) as an alternative to dry heat microbial reduction to meet planetary protection requirements. The VHP sterilization technology is widely used by the medical industry, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal of our study is determine the minimum VHP process conditions for PP acceptable microbial reduction levels. A series of experiments were conducted using Geobacillus stearothermophilus to determine VHP process parameters that provided significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters -hydrogen peroxide concentration, number of pulses, and exposure duration -the investigation also considered the possible effect of environmental pa-rameters. Temperature, relative humidity, and material substrate effects on lethality were also studied. Based on the results, a most conservative D value was recommended. This recom-mended D value was also validated using VHP "hardy" strains that were isolated from clean-rooms and environmental populations collected from spacecraft relevant areas. The efficiency of VHP at ambient condition as well as VHP material compatibility will also be

  15. Alkaline Phosphatase Activity in San Francisco and Monterey Bays

    NASA Astrophysics Data System (ADS)

    Nicholson, D. P.

    2002-12-01

    Phosphorus (P) is an essential nutrient utilized by all living organisms, and has been recognized as a limiting nutrient in some oceanic systems (Cotner et al., 1997; Karl et al., 1995; Michaels et al., 1996; Wu et al., 2000). However, relatively little is known about the extent of P limitation in natural environments, how P limitation varies spatially and temporally, and what determines how and when P becomes limiting (Benitez-Nelson, 2000). A more direct estimate of the degree of P limitation in a variety of oceanic systems is needed to better understand P cycling and dynamics within the ocean and how these have and will change in response to global climate and environmental perturbation. Accordingly, the objective this study is to assess the P-status of marine planktonic communities in Monterey and San Francisco Bays using the activity of alkaline phosphatase in the water column. Alkaline phosphatase (AP) is the most widely used enzyme that marine organisms use to hydrolize organic P compounds to biologically available orthophosphate. Accordingly it is expected that in areas where P is a limiting nutrient organisms will produce and release more AP to seawater so they can utilize the dissolved and particulate organic P compounds. Indeed it has been suggested that the AP activity is a reliable indicator of P-availability to planktonic communities (Ammerman and Azam, 1985; Cotner and Wetzel, 1991; Hong et al., 1998). High enzyme activities indicate low dissolved inorganic phosphate (DIP) availability while low levels suggest that DIP supply satisfies the community P-demand. This study examines AP activity in San Francisco and Monterey Bays over a 12 month period, from November, 2001 through November, 2002 using two enzyme assays. The study encompasses data from a three-station transect in Monterey Bay, at depths ranging from 0-60 meters. The stations range from coastal waters to open ocean depths of several thousand meters. In San Francisco Bay, surface water from

  16. Coupling alkaline pre-extraction with alkaline-oxidative post-treatment of corn stover to enhance enzymatic hydrolysis and fermentability

    PubMed Central

    2014-01-01

    Background A two-stage chemical pretreatment of corn stover is investigated comprising an NaOH pre-extraction followed by an alkaline hydrogen peroxide (AHP) post-treatment. We propose that conventional one-stage AHP pretreatment can be improved using alkaline pre-extraction, which requires significantly less H2O2 and NaOH. To better understand the potential of this approach, this study investigates several components of this process including alkaline pre-extraction, alkaline and alkaline-oxidative post-treatment, fermentation, and the composition of alkali extracts. Results Mild NaOH pre-extraction of corn stover uses less than 0.1 g NaOH per g corn stover at 80°C. The resulting substrates were highly digestible by cellulolytic enzymes at relatively low enzyme loadings and had a strong susceptibility to drying-induced hydrolysis yield losses. Alkaline pre-extraction was highly selective for lignin removal over xylan removal; xylan removal was relatively minimal (~20%). During alkaline pre-extraction, up to 0.10 g of alkali was consumed per g of corn stover. AHP post-treatment at low oxidant loading (25 mg H2O2 per g pre-extracted biomass) increased glucose hydrolysis yields by 5%, which approached near-theoretical yields. ELISA screening of alkali pre-extraction liquors and the AHP post-treatment liquors demonstrated that xyloglucan and β-glucans likely remained tightly bound in the biomass whereas the majority of the soluble polymeric xylans were glucurono (arabino) xylans and potentially homoxylans. Pectic polysaccharides were depleted in the AHP post-treatment liquor relative to the alkaline pre-extraction liquor. Because the already-low inhibitor content was further decreased in the alkaline pre-extraction, the hydrolysates generated by this two-stage pretreatment were highly fermentable by Saccharomyces cerevisiae strains that were metabolically engineered and evolved for xylose fermentation. Conclusions This work demonstrates that this two

  17. Isolation of alkaline mutagens from complex mixtures

    SciTech Connect

    Ho, C.H.; Guerin, M.R.; Clark, B.R.; Rao, T.K.; Epler, J.L.

    1981-05-01

    A method for the preparative-scale enrichment of alkaline mutagens from complex natural and anthropogenic mixtures is described. Mutagenic alkaline fractions were isolated from cigarette smoke, crude petroleum, and petroleum substitutes derived from coal and shale.

  18. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, David B.; Lao, Guifang

    1998-01-01

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium.

  19. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, D.B.; Lao, G.

    1998-01-06

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium. 3 figs.

  20. ELECTROCHEMICAL CORROSION TESTING OF TANKS 241-AN-102 & 241-AP-107 & 241-AP-108 IN SUPPORT OF ULTRASONIC TESTING

    SciTech Connect

    WYRWAS RB; DUNCAN JB

    2008-11-20

    This report presents the results of the corrosion rates that were measured using electrochemical methods for tanks 241-AN-102 (AN-102), 241-AP-107 (AP 107), and 241-AP-108 (AP-108) performed under test plant RPP-PLAN-38215. The steel used as materials of construction for AN and AP tank farms was A537 Class 1. Test coupons of A537 Class 1 carbon steel were used for corrosion testing in the AN-107, AP-107, and AP-108 tank waste. Supernate will be tested from AN-102, AP-107, and Ap-108. Saltcake testing was performed on AP-108 only.

  1. Coaching Strategies for AP: Building a Successful AP European History Program

    ERIC Educational Resources Information Center

    Fornaciari, Jim

    2014-01-01

    The October 2013 special issue of "Social Education" dealt with almost all AP social studies subjects, but omitted AP European History. This is one of the most fascinating AP subjects for students and teachers alike. In this article, the author shares his experiences since hewas given the responsibility of building his school's…

  2. AP Music Theory in Your School.

    ERIC Educational Resources Information Center

    Lucia, Raymond

    1993-01-01

    Asserts that an Advanced Placement (AP) course in music theory offers student musicians opportunities to gain new insight into melody, harmony, and structure. Describes content and teaching methods used in an AP music theory program. Discusses necessary teacher characteristics and maintains that both students and teachers benefit from the course.…

  3. Toward lattice QCD simulation on AP1000

    NASA Astrophysics Data System (ADS)

    Ohta, Shigemi

    AP1000 is Fujitsu Laboratory's experimental parallel computer consisting of up to 1024 microcomputers called cells. It is found that each AP1000 cell can sustain two to three megaflops computational speed for full QCD lattice numerical simulations in IEEE 64-bit floating point format

  4. AP-42 ADDITIONS AND REVISIONS - WILDLAND FIRES

    EPA Science Inventory

    This project is aimed at consolidating, selecting, and disseminating the most appropriate data and methods for estimating air emissions from wildfires and prescribed burns. The product will replace a current section of AP-42, but may not take the precise form of an AP-42 secti...

  5. Advanced APS impacts on vehicle payloads

    NASA Astrophysics Data System (ADS)

    Schneider, Steven J.; Reed, Brian D.

    1989-04-01

    Advanced auxiliary propulsion system (APS) technology has the potential to both, increase the payload capability of earth-to-orbit (ETO) vehicles by reducing APS propellant mass, and simplify ground operations and logistics by reducing the number of fluids on the vehicle and eliminating toxic, corrosive propellants. The impact of integrated cryogenic APS on vehicle payloads is addressed. In this system, launch propulsion system residuals are scavenged from integral launch propulsion tanks for use in the APS. Sufficient propellant is preloaded into the APS to return to earth with margin and noncomplete scavenging assumed. No propellant conditioning is required by the APS, but ambient heat soak is accommodated. High temperature rocket materials enable the use of the unconditioned hydrogen/oxygen in the APS and are estimated to give APS rockets specific impulse of up to about 444 sec. The payload benefits are quantified and compared with an uprated monomethylhydrazine/nitrogen tetroxide system in a conservative fashion, by assuming a 25.5 percent weight growth for the hydrogen/oxygen system and a 0 percent weight growth for the uprated system. The combination of scavenging and high performance gives payload impacts which are highly mission specific. A payload benefit of 861 kg (1898 lbm) was estimated for a Space Station Freedom rendezvous mission and 2099 kg (4626 lbm) for a sortie mission, with payload impacts varying with the amount of launch propulsion residual propellants. Missions without liquid propellant scavenging were estimated to have payload penalties, however, operational benefits were still possible.

  6. AP Courses Get Audited for Quality

    ERIC Educational Resources Information Center

    Ashford, Ellie

    2007-01-01

    As the college admissions process has gotten much more competitive, the number of high school students taking Advanced Placement (AP) courses has soared. At the same time, policymakers and education leaders seek to get more minorities and students not on the college track to sign up for AP and other rigorous classes. But as high schools have…

  7. Advanced APS Impacts on Vehicle Payloads

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Reed, Brian D.

    1989-01-01

    Advanced auxiliary propulsion system (APS) technology has the potential to both, increase the payload capability of earth-to-orbit (ETO) vehicles by reducing APS propellant mass, and simplify ground operations and logistics by reducing the number of fluids on the vehicle and eliminating toxic, corrosive propellants. The impact of integrated cryogenic APS on vehicle payloads is addressed. In this system, launch propulsion system residuals are scavenged from integral launch propulsion tanks for use in the APS. Sufficient propellant is preloaded into the APS to return to earth with margin and noncomplete scavenging assumed. No propellant conditioning is required by the APS, but ambient heat soak is accommodated. High temperature rocket materials enable the use of the unconditioned hydrogen/oxygen in the APS and are estimated to give APS rockets specific impulse of up to about 444 sec. The payload benefits are quantified and compared with an uprated monomethyl hydrazine/nitrogen tetroxide system in a conservative fashion, by assuming a 25.5 percent weight growth for the hydrogen/oxygen system and a 0 percent weight growth for the uprated system. The combination and scavenging and high performance gives payload impacts which are highly mission specific. A payload benefit of 861 kg (1898 lbm) was estimated for a Space Station Freedom rendezvous mission and 2099 kg (4626 lbm) for a sortie mission, with payload impacts varying with the amount of launch propulsion residual propellants. Missions without liquid propellant scavenging were estimated to have payload penalties, however, operational benefits were still possible.

  8. Advanced APS impacts on vehicle payloads

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Reed, Brian D.

    1989-01-01

    Advanced auxiliary propulsion system (APS) technology has the potential to both, increase the payload capability of earth-to-orbit (ETO) vehicles by reducing APS propellant mass, and simplify ground operations and logistics by reducing the number of fluids on the vehicle and eliminating toxic, corrosive propellants. The impact of integrated cryogenic APS on vehicle payloads is addressed. In this system, launch propulsion system residuals are scavenged from integral launch propulsion tanks for use in the APS. Sufficient propellant is preloaded into the APS to return to earth with margin and noncomplete scavenging assumed. No propellant conditioning is required by the APS, but ambient heat soak is accommodated. High temperature rocket materials enable the use of the unconditioned hydrogen/oxygen in the APS and are estimated to give APS rockets specific impulse of up to about 444 sec. The payload benefits are quantified and compared with an uprated monomethylhydrazine/nitrogen tetroxide system in a conservative fashion, by assuming a 25.5 percent weight growth for the hydrogen/oxygen system and a 0 percent weight growth for the uprated system. The combination of scavenging and high performance gives payload impacts which are highly mission specific. A payload benefit of 861 kg (1898 lbm) was estimated for a Space Station Freedom rendezvous mission and 2099 kg (4626 lbm) for a sortie mission, with payload impacts varying with the amount of launch propulsion residual propellants. Missions without liquid propellant scavenging were estimated to have payload penalties, however, operational benefits were still possible.

  9. The status of APS, BESSRC, and NEET.

    SciTech Connect

    Ahmad, I.; Dunford, R. W.; Esbensen, H.; Gemmell, D. S.; Kanter, E. P.; Kraessig, B.; Rutt, U.; Southworth, S. H.

    1999-03-10

    We present a brief summary of the current status of the Advanced Photon Source (APS) at Argonne National Laboratory and of the facilities at two of the APS sectors operated by the Basic Energy Sciences Synchrotrons Radiation Center (BESSRC). This is followed by a report on recent measurements at BESSRC on the phenomenon of Nuclear Excitation by Electronic Transition (NEET).

  10. Microcalorimetric Measurements of Hydrogen Peroxide Stability

    NASA Technical Reports Server (NTRS)

    Davis, Dennis D.; Hornung, Steven D.; Baker, Dave L.

    1999-01-01

    Recent interest in propellants with nontoxic reaction products has led to a resurgence of interest in hydrogen peroxide for various propellant applications. Because hydrogen peroxide is sensitive to contaminants and materials interactions, stability and shelf life are issues. A relatively new, ultrasensitive heat measurement technique, isothermal microcalorimetry, is being used at the White Sands Test Facility to monitor the decomposition of hydrogen peroxide at near ambient temperatures. Isothermal microcalorimetry measures the beat flow from a reaction vessel into a surrounding heat sink. In these applications, microcalorimetry is approximately 1,000 times more sensitive than accelerating rate calorimetry or differential scanning calorimetry for measuring thermal events. Experimental procedures have been developed for the microcalorimetric measurement of the ultra-small beat effects caused by incompatible interactions of hydrogen peroxide. The decomposition rates of hydrogen peroxide at the picomole/sec/gram level have been measured showing the effects of stabilizers and peroxide concentration. Typical measurements are carried out at 40 C over a 24-hour period, This paper describes a method for the conversion of the heat flow measurements to chemical reaction rates based on thermochemical considerations. The reaction rates are used in a study of the effects of stabilizer levels on the decomposition of propellant grade hydrogen peroxide.

  11. Combustion Response of AP Composite Propellants

    NASA Technical Reports Server (NTRS)

    Shusser, Michael; Cohen, Norman S.; Culick, E. C.

    2000-01-01

    The Cohen & Strand model for AP composite propellants is applied as boundary conditions, one for AP and one for binder, in solving the heat conduction equation in each to compute linear and non-linear combustion response properties for each and for the aggregate propellant. Iterations couple AP and binder through the quasi-steady flame processes. Illustrative results for linear response functions (pressure-coupled and velocity-coupled) are presented for a monomodal AP propellant varying AP size, pressure and crossflow speed, and examples of non-linear responses to arbitrary waveforms are shown. A quantitative comparison with response function data is limited to one well-characterized research formulation. Mechanistic implications are discussed, including recommendations for future modeling work.

  12. APS undulator radiation: First results

    SciTech Connect

    Cai, Z.; Dejus, R.J.; Hartog, P.D.

    1995-12-31

    The first undulator radiation has been extracted from the Advanced Photon Source (APS). The results from the characterization of this radiation are very satisfactory. With the undulator set at a gap of 15.8 mm (K=1.61), harmonics as high as the 17th were observed using a crystal spectrometer. The angular distribution of the third-harmonic radiation was measured, and the source was imaged using a zone plate to determine the particle beam emittance. The horizontal beam emittance was found to be 6.9 {plus_minus} 1.0 nm-rad, and the vertical emittance coupling was found to be less than 3%. The absolute spectral flux was measured over a wide range of photon energies, and it agrees remarkably well with the theoretical calculations based on the measured undulator magnetic field profile and the measured beam emittance. These results indicate that both the emittance of the electron beam and the undulator magnetic field quality exceed the original specifications.

  13. Modulation of Symbiont Lipid A Signaling by Host Alkaline Phosphatases in the Squid-Vibrio Symbiosis

    PubMed Central

    Rader, Bethany A.; Kremer, Natacha; Apicella, Michael A.; Goldman, William E.; McFall-Ngai, Margaret J.

    2012-01-01

    ABSTRACT The synergistic activity of Vibrio fischeri lipid A and the peptidoglycan monomer (tracheal cytotoxin [TCT]) induces apoptosis in the superficial cells of the juvenile Euprymna scolopes light organ during the onset of the squid-vibrio symbiosis. Once the association is established in the epithelium-lined crypts of the light organ, the host degrades the symbiont’s constitutively produced TCT by the amidase activity of a peptidoglycan recognition protein (E. scolopes peptidoglycan recognition protein 2 [EsPGRP2]). In the present study, we explored the role of alkaline phosphatases in transforming the lipid A of the symbiont into a form that changes its signaling properties to host tissues. We obtained full-length open reading frames for two E. scolopes alkaline phosphatase (EsAP) mRNAs (esap1 and esap2); transcript levels suggested that the dominant light organ isoform is EsAP1. Levels of total EsAP activity increased with symbiosis, but only after the lipid A-dependent morphogenetic induction at 12 h, and were regulated over the day-night cycle. Inhibition of total EsAP activity impaired normal colonization and persistence by the symbiont. EsAP activity localized to the internal regions of the symbiotic juvenile light organ, including the lumina of the crypt spaces where the symbiont resides. These data provide evidence that EsAPs work in concert with EsPGRPs to change the signaling properties of bacterial products and thereby promote persistent colonization by the mutualistic symbiont. PMID:22550038

  14. Development of alkaline fuel cells.

    SciTech Connect

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassov's research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herring's group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  15. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2011-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  16. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  17. Effective alkaline metal-catalyzed oxidative delignification of hybrid poplar

    DOE PAGESBeta

    Bhalla, Aditya; Bansal, Namita; Stoklosa, Ryan J.; Fountain, Mackenzie; Ralph, John; Hodge, David B.; Hegg, Eric L.

    2016-02-09

    Background: Strategies to improve copper-catalyzed alkaline hydrogen peroxide (Cu-AHP) pretreatment of hybrid poplar were investigated. These improvements included a combination of increasing hydrolysis yields, while simultaneously decreasing process inputs through (i) more efficient utilization of H2O2 and (ii) the addition of an alkaline extraction step prior to the metal-catalyzed AHP pretreatment. We hypothesized that utilizing this improved process could substantially lower the chemical inputs needed during pretreatment. Results: Hybrid poplar was pretreated utilizing a modified process in which an alkaline extraction step was incorporated prior to the Cu-AHP treatment step and H2O2 was added batch-wise over the course of 10more » h. Our results revealed that the alkaline pre-extraction step improved both lignin and xylan solubilization, which ultimately led to improved glucose (86 %) and xylose (95 %) yields following enzymatic hydrolysis. An increase in the lignin solubilization was also observed with fed-batch H2O2 addition relative to batch-only addition, which again resulted in increased glucose and xylose yields (77 and 93 % versus 63 and 74 %, respectively). Importantly, combining these strategies led to significantly improved sugar yields (96 % glucose and 94 % xylose) following enzymatic hydrolysis. In addition, we found that we could substantially lower the chemical inputs (enzyme, H2O2, and catalyst), while still maintaining high product yields utilizing the improved Cu-AHP process. This pretreatment also provided a relatively pure lignin stream consisting of ≥90 % Klason lignin and only 3 % xylan and 2 % ash following precipitation. Two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR and size-exclusion chromatography demonstrated that the solubilized lignin was high molecular weight (Mw ≈ 22,000 Da) and only slightly oxidized relative to lignin from untreated poplar. In conclusion: This study demonstrated that the fed

  18. Isothermal Decomposition of Hydrogen Peroxide Dihydrate

    NASA Technical Reports Server (NTRS)

    Loeffler, M. J.; Baragiola, R. A.

    2011-01-01

    We present a new method of growing pure solid hydrogen peroxide in an ultra high vacuum environment and apply it to determine thermal stability of the dihydrate compound that forms when water and hydrogen peroxide are mixed at low temperatures. Using infrared spectroscopy and thermogravimetric analysis, we quantified the isothermal decomposition of the metastable dihydrate at 151.6 K. This decomposition occurs by fractional distillation through the preferential sublimation of water, which leads to the formation of pure hydrogen peroxide. The results imply that in an astronomical environment where condensed mixtures of H2O2 and H2O are shielded from radiolytic decomposition and warmed to temperatures where sublimation is significant, highly concentrated or even pure hydrogen peroxide may form.

  19. 21 CFR 184.1366 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... vinegar Amount sufficient for the purpose Remove sulfur dioxide from wine prior to fermentation to produce vinegar. Emulsifiers containing fatty acid esters 1.25 Bleaching agent. (d) Residual hydrogen peroxide...

  20. NASA Hydrogen Peroxide Propellant Hazards Technical Manual

    NASA Technical Reports Server (NTRS)

    Baker, David L.; Greene, Ben; Frazier, Wayne

    2005-01-01

    The Fire, Explosion, Compatibility and Safety Hazards of Hydrogen Peroxide NASA technical manual was developed at the NASA Johnson Space Center White Sands Test Facility. NASA Technical Memorandum TM-2004-213151 covers topics concerning high concentration hydrogen peroxide including fire and explosion hazards, material and fluid reactivity, materials selection information, personnel and environmental hazards, physical and chemical properties, analytical spectroscopy, specifications, analytical methods, and material compatibility data. A summary of hydrogen peroxide-related accidents, incidents, dose calls, mishaps and lessons learned is included. The manual draws from art extensive literature base and includes recent applicable regulatory compliance documentation. The manual may be obtained by United States government agencies from NASA Johnson Space Center and used as a reference source for hazards and safe handling of hydrogen peroxide.

  1. Development of the AP Technology Through Time

    NASA Astrophysics Data System (ADS)

    Charmier, F.; Martin, O.; Gariepy, R.

    2015-02-01

    This article presents the historical development of the AP Technology (Aluval, Voreppe, France) pot series starting with the AP13 in the 1960s, followed by the AP18 and the AP30 in the 1980s and 1990s. For most of the modern-era technology, from the late 1970s on, development has been based on a three-stage pattern, the first one being the pot modeling, followed by the pot prototype stage, and then the industrial stage, which fully validated the technology. This development pattern has proven to be successful since it has led to the very robust AP Technology pot design generation and a large number of greenfield smelters built in the 1990-2010 selected the AP Technology design. AP60 is the latest of this series: The development at the prototype level was initiated in the 1990s and is presented in the article. It is now followed by the first industrial realization at Jonquière with the startup in late 2013 and the full validation of the technology in mid-2014. The development of APXe, which aims at very low energy consumption, uses many common elements pertaining to the AP60 design and is presented in the article. AP Technology has also addressed the need for continuous and fast improvement of pot performances adapted to each existing client or site specifics; for this purpose, a new development methodology has recently emerged thanks to the very high modeling capabilities. This methodology, based on the validation of "technology bricks" and their integration in the final design following a strict process, is presented in the last section of this article.

  2. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  3. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell

    PubMed Central

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D.

    2012-01-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells. PMID:23457415

  4. Lipid Peroxidation by Human Blood Phagocytes

    PubMed Central

    Stossel, Thomas P.; Mason, Robert J.; Smith, Arnold L.

    1974-01-01

    Cell suspensions enriched in human blood monocytes, obtained from normal peripheral blood by sedimentation on sodium diatrizoate-Ficoll gradients or from the blood of patients with neutropenia and monocytosis, accumulated malonyldialdehyde, a labile catabolite of lipid peroxidation, during incubations with polystyrene beads or heat-killed Staphylococcus epidermidis. Mixed blood leukocytes principally composed of granulocytes or granulocytes purified by density gradient sedimentation did not accumulate malonyldialdehyde during incubations with these particles, but did when ingesting particles containing linolenate. The phospholipid fatty acid composition of monocyte-enriched and purified granulocyte preparations from the same donors were compared. The molar fraction of arachidonate (20:4) in phospholipids from monocyte-rich preparations was 62% greater than that of purified granulocytes. The findings indicate that human monocytes, possibly because of a greater content of polyunsaturated fatty acids in their membranes, peroxidize a greater quantity of endogenous lipids than granulocytes during endocytosis. Normal human granulocytes have the capacity to peroxidize ingested lipids. However, mixed leukocytes from two patients with chronic granulomatous disease produced little malonyldialdehyde when engulfing linolenate-containing particles. Therefore the capacity to peroxidize lipid is related to cellular oxygen metabolism, a function in which chronic granulomatous disease granulocytes are dificient. Malonyldialdehyde chemically prepared by hydrolysis of tetramethoxypropane, by extraction from peroxidized linolenic acid, or purified from extracts of phagocytizing rabbit alveolar macrophages had bactericidal activity against Escherichia coli and S. epidermidis. Therefore, toxic catabolites of lipid hydroperoxides may potentiate the bactericidal activity of hydrogen peroxide in mononuclear phagocytes. PMID:4853010

  5. EFFLUENT TREATMENT FACILITY PEROXIDE DESTRUCTION CATALYST TESTING

    SciTech Connect

    HALGREN DL

    2008-07-30

    The 200 Area Effluent Treatment Facility (ETF) main treatment train includes the peroxide destruction module (PDM) where the hydrogen peroxide residual from the upstream ultraviolet light/hydrogen peroxide oxidation unit is destroyed. Removal of the residual peroxide is necessary to protect downstream membranes from the strong oxidizer. The main component of the PDM is two reaction vessels utilizing granular activated carbon (GAC) as the reaction media. The PDM experienced a number of operability problems, including frequent plugging, and has not been utilized since the ETF changed to groundwater as the predominant feed. The unit seemed to be underperforming in regards to peroxide removal during the early periods of operation as well. It is anticipated that a functional PDM will be required for wastewater from the vitrification plant and other future streams. An alternate media or methodology needs to be identified to replace the GAC in the PDMs. This series of bench scale tests is to develop information to support an engineering study on the options for replacement of the existing GAC method for peroxide destruction at the ETF. A number of different catalysts will be compared as well as other potential methods such as strong reducing agents. The testing should lead to general conclusions on the viability of different catalysts and identify candidates for further study and evaluation.

  6. Astragalus Polysaccharide Inhibits Autophagy and Apoptosis from Peroxide-Induced Injury in C2C12 Myoblasts.

    PubMed

    Yin, Yi; Lu, Lu; Wang, Dongtao; Shi, Ying; Wang, Ming; Huang, Yanfeng; Chen, Dexiu; Deng, Cong; Chen, Jiebin; Lv, Peijia; Wang, Yanjing; Li, Chengjie; Wei, Lian-Bo

    2015-11-01

    The aim is to study the effects and underlying mechanisms of astragalus polysaccharide (APS) on the peroxide-induced injury in C2C12 myoblasts in vitro. Cell viability in the presence or absence of APS was detected by the methyl thiazolyl tetrazolium colorimetric assay. The autophagosomes were observed by electron microscopy to examine the influence of APS on autophagy caused by H2O2 in C2C12 cells, and the percentage of apoptosis cells was measured by flow cytometry. To further confirm the effect of H2O2 on C2C12 cells, the protein expression of LC3 and RARP, which are the markers of autophagy and apoptosis, respectively, was analyzed by Western blot, as well as the expression levels of p-p70S6K, p70S6K, Bcl-2, Bax, cyto-C, and Caspase-3, to reveal the underlying mechanisms. We observed multiple effects of APS on C2C12 functionality. APS treatment of C2C12 cells at 1 mg/mL reduced cell viability to less than 70 %, and analysis by electron microscopy revealed that APS also reduced the number of H2O2-induced autophagosome formation. Similarly, APS abated the H2O2-mediated increase in cell apoptosis, which was accompanied by the inhibition of LC3 II and RARP that are normally upregulated by H2O2. The expression of p-p70S6K and p70S6K, however, remained unchanged in C2C12 cells in the Control, H2O2 and H2O2 + APS groups. In addition, APS promoted the expression of protein Bcl-2 in H2O2-treated C2C12 cells, but did not change Bax, thus reducing the Bax/Bcl-2 ratio that in turn prevented the release of cytochrome c and the activation of caspase-3. APS inhibits the autophagy and apoptosis induced by peroxide injury in C2C12 myoblasts through two independent signaling pathways: the mTOR-independent pathway for the inhibition of autophagy, and the caspase-3-dependent pathway for the suppression of apoptosis. PMID:27352334

  7. APS Activities with Other Professional Societies

    NASA Astrophysics Data System (ADS)

    Slakey, Francis

    2006-03-01

    In 1981, the APS Council issued a statement that opposed ``equal time'' presentation in public school science classes of creationism and evolution. The statement clarified that ``Scientific inquiry and religious beliefs are two distinct elements of the human experience. Attempts to present them in the same context can only lead to misunderstandings of both.'' The APS Council revisited the issue in 1999 when a school board in Kansas attempted to eliminate the Big Bang, among other issues, from the science curriculum. Since that time, the APS has been more directly involved in confronting efforts that would dilute the teaching of science in public school science classes. This talk will review the APS activities and describe a developing multi-science society activity.

  8. Anode conductor for alkaline cells

    SciTech Connect

    Schrenk, D.J.; Murphy, P.E.

    1988-12-13

    This patent describes an electrochemical cell comprised of an anode comprised of zinc; a cathode; and alkaline electrolyte; and a current collector comprised of a silicon bronze alloy that is comprised of 85-98% by weight copper and 1-5% by weight silicon with the remainder being comprised of at least one of manganese, iron, zinc, aluminum, tin, lead, or mixtures thereof; and a strip of metal tab stock welded to the current collector, the tab stock being a metal other than silicon bronze alloy.

  9. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more than two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  10. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  11. PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES

    DOEpatents

    Barrick, J.G.; Fries, B.A.

    1960-09-27

    A procedure is given for peroxide precipitation processes for separating and recovering plutonium values contained in an aqueous solution. When plutonium peroxide is precipitated from an aqueous solution, the supernatant contains appreciable quantities of plutonium and peroxide. It is desirable to process this solution further to recover plutonium contained therein, but the presence of the peroxide introduces difficulties; residual hydrogen peroxide contained in the supernatant solution is eliminated by adding a nitrite or a sulfite to this solution.

  12. Recombinant production and characterization of a highly active alkaline phosphatase from marine bacterium Cobetia marina.

    PubMed

    Golotin, Vasily; Balabanova, Larissa; Likhatskaya, Galina; Rasskazov, Valery

    2015-04-01

    The psychrophilic marine bacterium, Cobetia marina, recovered from the mantle tissue of the marine mussel, Crenomytilus grayanus, which contained a gene encoding alkaline phosphatase (AP) with apparent biotechnology advantages. The enzyme was found to be more efficient than its counterparts and showed k cat value 10- to 100-fold higher than those of all known commercial APs. The enzyme did not require the presence of exogenous divalent cations and dimeric state of its molecule for activity. The recombinant enzyme (CmAP) production and purification were optimized with a final recovery of 2 mg of the homogenous protein from 1 L of the transgenic Escherichia coli Rosetta(DE3)/Pho40 cells culture. CmAP displayed a half-life of 16 min at 45 °C and 27 min at 40 °C in the presence of 2 mM EDTA, thus suggesting its relative thermostability in comparison with the known cold-adapted analogues. A high concentration of EDTA in the incubation mixture did not appreciably inhibit CmAP. The enzyme was stable in a wide range of pH (6.0-11.0). CmAP exhibited its highest activity at the reaction temperature of 40-50 °C and pH 9.5-10.3. The structural features of CmAP could be the reason for the increase in its stability and catalytic turnover. We have modeled the CmAP 3D structure on the base of the high-quality experimental structure of the close homologue Vibrio sp. AP (VAP) and mutated essential residues predicted to break Mg(2+) bonds in CmAP. It seems probable that the intrinsically tight binding of catalytic and structural metal ions together with the flexibility of intermolecular and intramolecular links in CmAP could be attributed to the adapted mutualistic lifestyle in oceanic waters. PMID:25260971

  13. (Very) Slow Rotation of Magnetic Ap Stars

    NASA Astrophysics Data System (ADS)

    Mathys, G.

    2015-04-01

    To this date, 33 magnetic Ap stars that have periods of variation longer than 30 days are known. They represent a considerable fraction of the total number of Ap stars whose period has been reliably determined. All the available evidence unambiguously indicates that the observed variations of those long-period Ap stars result from the changing aspect of their visible hemisphere as they rotate, thus that the oblique rotator model is applicable throughout the whole range of periods of variation of the Ap stars. We show that the periods of the most slowly rotating Ap stars must be of the order of 300 years, and that some may even be longer, possibly up to 1000 years. The 5 to 6 orders of magnitude spanned by the rotation periods of the Ap stars present a major challenge for the understanding of their origin and their evolution. To guide the theoretical developments, observational hints may be found in possible differences between the magnetic properties of stars that have rotation periods in different ranges. Such differences are starting to emerge from the existing data. To increase their significance level, study of the longest-period stars must be continued over their full rotation cycle. Failure to secure observations now may leave critical data missing for several decades, or even centuries.

  14. Catalyst Development for Hydrogen Peroxide Rocket Engines

    NASA Technical Reports Server (NTRS)

    Morlan, P. W.; Wu, P.-K.; Ruttle, D. W.; Fuller, R. P.; Nejad, A. S.; Anderson, W. E.

    1999-01-01

    The development of various catalysts of hydrogen peroxide was conducted for the applications of liquid rocket engines. The catalyst development includes silver screen technology, solid catalyst technology, and homogeneous catalyst technology. The silver screen technology development was performed with 85% (by weight) hydrogen peroxide. The results of this investigation were used as the basis for the catalyst design of a pressure-fed liquid-fueled upper stage engine. Both silver-plated nickel 200 screens and pure silver screens were used as the active metal catalyst during the investigation, The data indicate that a high decomposition efficiency (greater than 90%) of 85% hydrogen peroxide can be achieved at a bed loading of 0.5 lbm/sq in/sec with both pure silver and silver plated screens. Samarium oxide coating, however, was found to retard the decomposition process and the catalyst bed was flooded at lower bed loading. A throughput of 200 lbm of hydrogen peroxide (1000 second run time) was tested to evaluate the catalyst aging issue and performance degradation was observed starting at approximately 400 seconds. Catalyst beds of 3.5 inch in diameter was fabricated using the same configuration for a 1,000-lbf rocket engine. High decomposition efficiency was obtained with a low pressure drop across the bed. Solid catalyst using precious metal was also developed for the decomposition of hydrogen peroxide from 85% to 98% by weight. Preliminary results show that the catalyst has a strong reactivity even after 15 minutes of peroxide decomposition. The development effort also includes the homogeneous catalyst technology. Various non-toxic catalysts were evaluated with 98% peroxide and hydrocarbon fuels. The results of open cup drop tests indicate an ignition delay around 11 ms.

  15. Antioxidant and Physicochemical Properties of Hydrogen Peroxide-Treated Sugar Beet Dietary Fibre.

    PubMed

    Mišan, Aleksandra; Sakač, Marijana; Medić, Đorđe; Tadić, Vanja; Marković, Goran; Gyura, Julliana; Pagano, Ester; Izzo, Angelo A; Borrelli, Francesca; Šarić, Bojana; Milovanović, Ivan; Milić, Nataša

    2016-05-01

    The aim of the present work was to examine if hydrogen peroxide treatment of sugar beet fibre that aimed at improving its physicochemical properties would impair its antioxidant potential. Three different sugar beet fibres were obtained from sugar beet - non-treated fibre (NTF) from sugar beet cossettes extracted with sulphurous acid, treated fibre (TF) from NTF treated with hydrogen peroxide in alkaline solution and commercially available Fibrex(®) . The antioxidant activity of extractable and non-extractable fibre fractions in ethanol/water mixture (80:20, v/v) of three fibre samples was estimated. Non-extractable fractions obtained after alkaline treatment of investigated fibres were much higher in phenolic compounds and possessed higher antioxidant potential than extractable fractions. Ferulic acid was proven to be the dominant phenolic acid. Regarding both extractable and non-extractable fractions, Fibrex(®) had the highest antioxidant activity in chemical tests, while NTF was superior in comparison with TF. Based on the results of Caco-2 cells-based test, all non-extractable fractions possessed potential for reactive oxygen species inhibition. Regarding the extractable fractions, only the TF manifested this effect.Copyright © 2016 John Wiley & Sons, Ltd. PMID:26929014

  16. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  17. Grace DAKASEP alkaline battery separator

    NASA Technical Reports Server (NTRS)

    Giovannoni, R. T.; Lundquist, J. T.; Choi, W. M.

    1987-01-01

    The Grace DAKASEP separator was originally developed as a wicking layer for nickel-zinc alkaline batteries. The DAKASEP is a filled non-woven separator which is flexible and heat sealable. Through modification of formulation and processing variables, products with a variety of properties can be produced. Variations of DAKASEP were tested in Ni-H2, Ni-Zn, Ni-Cd, and primary alkaline batteries with good results. The properties of DAKASEP which are optimized for Hg-Zn primary batteries are shown in tabular form. This separator has high tensile strength, 12 micron average pore size, relatively low porosity at 46-48 percent, and consequently moderately high resistivity. Versions were produced with greater than 70 percent porosity and resistivities in 33 wt percent KOH as low as 3 ohm cm. Performance data for Hg-Zn E-1 size cells containing DAKASEP with the properties shown in tabular form, are more reproducible than data obtained with a competitive polypropylene non-woven separator. In addition, utilization of active material is in general considerably improved.

  18. Safe handling of potential peroxide forming compounds and their corresponding peroxide yielded derivatives.

    SciTech Connect

    Sears, Jeremiah Matthew; Boyle, Timothy J.; Dean, Christopher J.

    2013-06-01

    This report addresses recent developments concerning the identification and handling of potential peroxide forming (PPF) and peroxide yielded derivative (PYD) chemicals. PPF chemicals are described in terms of labeling, shelf lives, and safe handling requirements as required at SNL. The general peroxide chemistry concerning formation, prevention, and identification is cursorily presented to give some perspective to the generation of peroxides. The procedure for determining peroxide concentrations and the proper disposal methods established by the Hazardous Waste Handling Facility are also provided. Techniques such as neutralization and dilution are provided for the safe handling of any PYD chemicals to allow for safe handling. The appendices are a collection of all available SNL documentation pertaining to PPF/PYD chemicals to serve as a single reference.

  19. Effects of vasectomy on seminal plasma alkaline phosphatase in male alpacas (Vicugña pacos).

    PubMed

    Pearson, L K; Campbell, A J; Sandoval, S; Tibary, A

    2013-12-01

    Azoospermia is a common finding in male alpacas which present for infertility. The challenge is to differentiate azoospermia of testicular origin from non-testicular origin. In several species, alkaline phosphatase (AP) concentrations in seminal plasma have been used as a diagnostic marker of contributions of the testis and epididymis to the ejaculate. The purpose of this study was to determine whether AP assay could differentiate testicular from non-testicular azoospermia in male alpacas. An experimental model of bilateral outflow obstruction (pre-scrotal vasectomy) was used in 22 male alpacas, aged 2-9 years. No reproductive history was available. Animals were submitted for electroejaculation (EE) under general anaesthesia and vasectomy performed. Five weeks later, animals were submitted for EE. Vasectomy was not successful in one animal, which was removed from analysis. AP levels were compared in seminal plasma in the pre- and post-vasectomy samples. The mean ± SEM concentration of AP in pre-vasectomy seminal plasma was 504.29 ± 166.45 U/l (range 10-2910); the post-vasectomy levels were 252.48 ± 81.77 U/l (range 0-1640; p = 0.06). In 71.4% of animals, AP levels decreased, varying from 18% to 100% reduction. Results of this study suggest that AP is not produced exclusively by the testis and epididymis in alpacas and that AP assay is not a valid diagnostic test for determination of origin of azoospermia; the gold standard for diagnosis of origin of azoospermia remains testicular biopsy. PMID:23790090

  20. Phytic Acid Inhibits Lipid Peroxidation In Vitro

    PubMed Central

    Węglarz, Ludmiła; Dzierżewicz, Zofia

    2013-01-01

    Phytic acid (PA) has been recognized as a potent antioxidant and inhibitor of iron-catalyzed hydroxyl radical formation under in vitro and in vivo conditions. Therefore, the aim of the present study was to investigate, with the use of HPLC/MS/MS, whether PA is capable of inhibiting linoleic acid autoxidation and Fe(II)/ascorbate-induced peroxidation, as well as Fe(II)/ascorbate-induced lipid peroxidation in human colonic epithelial cells. PA at 100 μM and 500 μM effectively inhibited the decay of linoleic acid, both in the absence and presence of Fe(II)/ascorbate. The observed inhibitory effect of PA on Fe(II)/ascorbate-induced lipid peroxidation was lower (10–20%) compared to that of autoxidation. PA did not change linoleic acid hydroperoxides concentration levels after 24 hours of Fe(II)/ascorbate-induced peroxidation. In the absence of Fe(II)/ascorbate, PA at 100 μM and 500 μM significantly suppressed decomposition of linoleic acid hydroperoxides. Moreover, PA at the tested nontoxic concentrations (100 μM and 500 μM) significantly decreased 4-hydroxyalkenal levels in Caco-2 cells which structurally and functionally resemble the small intestinal epithelium. It is concluded that PA inhibits linoleic acid oxidation and reduces the formation of 4-hydroxyalkenals. Acting as an antioxidant it may help to prevent intestinal diseases induced by oxygen radicals and lipid peroxidation products. PMID:24260736

  1. [Hydrogen peroxide in artificial photosynthesizing systems].

    PubMed

    Lobanov, A V; Komissarov, G G

    2014-01-01

    From the point of view of the concepts of hydrogen peroxide as a source of photosynthetic oxygen (hydrogen) coordination and photochemical properties of chlorophyll and its aggregates towards hydrogen peroxide were considered. The binding energy of H2O and H2O2 with chlorophyll and chlorophyllide depending on their form (monomers, dimers and trimers) was estimated by quantum chemical calculations. It is shown that at an increase of the degree of the pigment aggregation binding energy of H2O2 was more than the energy of H2O. Analysis of experimental results of the photochemical decomposition of hydrogen peroxide using chlorophyll was carried out. Estimates of the thermodynamic parameters (deltaG degrees and deltaH degrees) of the formation of organic compounds from CO2 with water and hydrogen peroxide were compared. The interaction of CO2 with H2O2 requires much less energy consumption than with water for all considered cases. The formation of organic products (formaldehyde, alcohols, carboxylic and carbonylic compounds) and simultaneous production of O2 under the influence of visible light in the systems of inorganic carbon--hydrogen peroxide--chlorophyll (phthalocyanine) is detected by GC/MS method, FTIR spectroscopy, and chemical analysis. PMID:25702472

  2. Alkaline and alkaline earth metal phosphate halides and phosphors

    SciTech Connect

    Lyons, Robert Joseph; Setlur, Anant Achyut; Cleaver, Robert John

    2012-11-13

    Compounds, phosphor materials and apparatus related to nacaphite family of materials are presented. Potassium and rubidium based nacaphite family compounds and phosphors designed by doping divalent rare earth elements in the sites of alkaline earth metals in the nacaphite material families are descried. An apparatus comprising the phosphors based on the nacaphite family materials are presented herein. The compounds presented is of formula A.sub.2B.sub.1-yR.sub.yPO.sub.4X where the elements A, B, R, X and suffix y are defined such that A is potassium, rubidium, or a combination of potassium and rubidium and B is calcium, strontium, barium, or a combination of any of calcium, strontium and barium. X is fluorine, chlorine, or a combination of fluorine and chlorine, R is europium, samarium, ytterbium, or a combination of any of europium, samarium, and ytterbium, and y ranges from 0 to about 0.1.

  3. Lipid peroxide formation in microsomes. Relationship of hydroxylation to lipid peroxide formation

    PubMed Central

    Wills, E. D.

    1969-01-01

    1. Aminopyrine strongly inhibits NADPH-induced lipid peroxide formation in rat liver microsomes, but ascorbate-induced peroxidation is inhibited to a smaller extent. 2. Aminopyrine oxidation is stimulated by Mg2+ but inhibited by Ca2+. Concentrated solutions (10mm) of iron-chelating agents inhibit aminopyrine oxidation, but the more dilute solutions (0·5mm) of chelators that block lipid peroxide formation do not inhibit aminopyrine oxidation. Microsomes prepared from sucrose–EDTA homogenates rapidly oxidize aminopyrine, but do not form lipid peroxide when incubated with ascorbate or NADPH. 3. Aminopyrine oxidation is strongly inhibited by p-chloromercuribenzoate, less by iodoacetamide and weakly by N-ethylmaleimide. The site of action of these compounds is considered to be a ferredoxin-type protein. GSH and cysteine also inhibit. 4. Other drugs oxidized by microsomes such as caffeine, phenobarbitone and hexobarbitone had either no or little effect on lipid peroxide formation, but codeine inhibited. 5. Most aliphatic hydrocarbons, alcohols, ketones and aldehydes did not affect lipid peroxide formation, but chloroform and carbon tetrachloride inhibited. 6. Many aromatic compounds inhibited lipid peroxide formation. Only aromatic acids were without any effect and phenols and amines were very strong inhibitors. 7. Induction of lipid peroxide formation in microsomes by incubation with ascorbate or NADPH or by treatment with ionizing radiation leads to a sharp decline in the ability of microsomes to oxidize aminopyrine or hydroxylate aniline. 8. It is considered that the two processes of hydroxylation and lipid peroxide formation are closely linked in microsomes. They probably depend on the same electron-transport chain, and peroxide formation, which involves membrane disintegration, may be part of the normal membrane remodelling process. PMID:4390103

  4. High-resolution analysis of Zn2+ coordination in the alkaline phosphatase superfamily by EXAFS and x-ray crystallography

    PubMed Central

    Bobyr, Elena; Lassila, Jonathan K.; Wiersma-Koch, Helen I.; Fenn, Timothy D.; Lee, Jason J.; Nikolic-Hughes, Ivana; Hodgson, Keith O.; Rees, Douglas C.; Hedman, Britt; Herschlag, Daniel

    2011-01-01

    Comparisons among evolutionarily related enzymes offer opportunities to reveal how structural differences produce different catalytic activities. Two structurally-related enzymes, E. coli alkaline phosphatase (AP) and X. axonopodis nucleotide pyrophosphatase/phosphodiesterase (NPP) have nearly identical binuclear Zn2+ catalytic centers, but show tremendous differential specificity for hydrolysis of phosphate monoesters or phosphate diesters. To determine if there are differences in Zn2+ coordination in the two enzymes that might contribute to catalytic specificity, we analyzed both x-ray absorption spectroscopic and x-ray crystallographic data. We report a 1.29 Å crystal structure of alkaline phosphatase with bound phosphate, allowing evaluation of interactions at the AP metal site with high resolution. To make systematic comparisons between AP and NPP, we measured zinc extended x-ray absorption fine structure (EXAFS) for AP and NPP in the free enzyme forms, with AMP and inorganic phosphate ground-state analogs, and with vanadate transition state analogs. These studies yielded average zinc-ligand distances in AP and NPP free-enzyme forms and ground-state analog forms that were identical within error, suggesting little difference in metal ion coordination among these forms. Upon binding of vanadate to both enzymes, small increases in average metal-ligand distances were observed, consistent with an increased coordination number. Slightly longer increases were observed in NPP relative to AP, which could arise from subtle rearrangements of the active site or differences in the geometry of the bound vanadyl species. Overall, the results suggest that the binuclear Zn2+ catalytic site remains very similar between AP and NPP during the course of a reaction cycle. PMID:22056344

  5. Antioxidant Potential of Plumieride against CCl4-Induced Peroxidative Damage in Rats

    PubMed Central

    Singh, Dharmendra; Arya, Priya Vrat; Sharma, Ashutosh; Aggarwal, Ved Prakash; Dobhal, Mahabeer Prasad; Gupta, Radhey Shyam

    2014-01-01

    In search of a new potent as an antioxidant from natural sources, plumieride—an iridoid isolated from the methanol extract of the bark of Plumeria bicolor (family Apocynaceae) was evaluated for its antioxidant potential against CCl4-induced peroxidative damage in liver of rats. The antioxidant potential was evaluated by using hepatic tissue for SOD (superoxide dismutase), CAT (catalase), GSH (reduced glutathione), GPx (glutathione peroxidase), GR (glutathione reductase) and LPO (lipid peroxidation) alongwith the concomitant blood serum for AST & ALT (aspartate and alanine transaminases), GGT (gamma glutamyl transpeptidase), ALP (alkaline phosphatase), total bilirubin and total protein contents. All the biochemical parameters were significantly (p ≤ 0.001) altered by CCl4 (0.3 mL/kg body weight/twice a week, intra-peritoneally for 30 days). Simultaneously, oral treatment with plumieride (5, 10 and 20 mg/kg body weight/day for 30 days), restored all the parameters towards a normal level, remarkably. The histological findings of liver sections further corroborated the antioxidant potential of plumieride compared with standard drug-silymarin. In conclusion, plumieride consists of sugar molecules, which have alcoholic groups. Therefore, the alcoholic groups of sugar increase its antioxidant potential through intermolecular hydrogen bonding along with the thiol(SH) group of non-protein thiols and enzymes resulting in the restoration of the antioxidant system. Therefore, it might be considered a natural antioxidant against peroxidative damage in rats. PMID:26785241

  6. Effect of Hypericum perforatum Aqueous Extracts on Serum Lipids, Aminotransferases, and Lipid Peroxidation in Hyperlipidemic Rats

    PubMed Central

    Ghosian Moghaddam, Mohammad Hassan; Roghani, Mehrdad; Maleki, Maryam

    2016-01-01

    Background: Patients with high levels of total cholesterol (TCH), low-density lipoprotein cholesterol (LDL-CH), and triglyceride (TG) are at increased risk of coronary heart disease. Studies have shown that flavonoids and antioxidant compounds have beneficial effects on hyperlipidemia. Objectives: The aim of the present study was to evaluate the effects of extract of Hypericum perforatum (EHP) on the serum lipid profile (TCH, TG, and LDL-CH), aminotransferase, alkaline phosphatase, and lipid peroxidation in hyperlipidemic rats. Materials and Methods: Thirty-two male rats weighting 200 ± 10 g were randomly divided into four experimental groups: 1) control, 2) control + EHP, 3) hyperlipidemia, and 4) hyperlipidemia + EHP. The rats in the hyperlipidemic groups were fed a high-fat diet for 60 days, and EHP (300 mg/kg) was injected intraperitoneally for 2 weeks in the rats in the second and fourth groups. At the end of the experimental period, blood samples from each group were analyzed. Results: There was a significant reduction in LDL-CH in the control + EHP group and the hyperlipidemia + EHP group (P < 0.05). TCH was significantly reduced in the control + EHP group (P < 0.05). There were no significant changes in the levels of TG and HDL-CH. Malondialdehyde, aspartate aminotransferase, and alanine aminotransferase were significantly reduced in the hyperlipidemia + EHP group (P < 0.05), with no significant change in alkaline phosphatase. Conclusions: EHP was able to both reduce LDL-CH and to significantly decrease markers of oxidative stress and lipid peroxidation induced by hyperlipidemia. Therefore, this herb, as a new pharmacological component, could be used to reduce certain blood lipids, lipid peroxidation, and aminotransferase markers. PMID:26949689

  7. Hydrogen Peroxide - Material Compatibility Studied by Microcalorimetry

    NASA Technical Reports Server (NTRS)

    Homung, Steven D.; Davis, Dennis D.; Baker, David; Popp, Christopher G.

    2003-01-01

    Environmental and toxicity concerns with current hypergolic propellants have led to a renewed interest in propellant grade hydrogen peroxide (HP) for propellant applications. Storability and stability has always been an issue with HP. Contamination or contact of HP with metallic surfaces may cause decomposition, which can result in the evolution of heat and gas leading to increased pressure or thermal hazards. The NASA Johnson Space Center White Sands Test Facility has developed a technique to monitor the decompositions of hydrogen peroxide at temperatures ranging from 25 to 60 C. Using isothermal microcalorimetry we have measured decomposition rates at the picomole/s/g level showing the catalytic effects of materials of construction. In this paper we will present the results of testing with Class 1 and 2 materials in 90 percent hydrogen peroxide.

  8. Simplified SBLOCA Analysis of AP1000

    SciTech Connect

    Brown, William L.

    2004-07-01

    The AP1000 is a 1000 MWe advanced nuclear power plant design that uses passive safety features such as a multi-stage, automatic depressurization system (ADS) and gravity-driven, safety injection from core make-up tanks (CMTs) and an in-containment refueling water storage tank (IRWST) to mitigate SBLOCA events. The period of most safety significance for AP1000 during a SBLOCA event is typically associated with the actuation of the fourth stage of the ADS and subsequent transition from CMT to IRWST safety injection. As this period of a SBLOCA is generally of a quasi-steady nature, the integral performance of the AP1000 can be understood and evaluated with a simplified model of the reactor vessel, ADS, and safety injection from the CMTs and IRWST. The simplified model of the AP1000 consists of a series of steady state simulations that uses drift flux in the core region and homogeneous treatment of the core exit region including the ADS flow paths to generate a family of core flow demand curves as a function of system pressure (i.e. mass flow required to satisfy core cooling). These core flow demand curves are plotted against passive safety system supply curves from the CMTs and IRWST to demonstrate the adequacy of the integral performance of the AP1000 during the most important phase of a SBLOCA. (author)

  9. Tank 241-AP-107, grab samples 7AP-97-1, 7AP-97-2 and 7AP-97-3 analytical results for the final report

    SciTech Connect

    Steen, F.H.

    1997-12-22

    This document is the final report for tank 241-AP-107 grab samples. Three grab samples were collected from riser 1 on September 11, 1997. Analyses were performed on samples 7AP-97-1, 7AP-97-2 and 7AP-97-3 in accordance with the Compatibility Grab Sampling and Analysis Plan (TSAP) (Sasaki, 1997) and the Data Quality Objectives for Tank Farms Waste Compatibility Program (DQO) (Rev. 1: Fowler, 1995; Rev. 2: Mulkey and Nuier, 1997). The analytical results are presented in the data summary report (Table 1). A notification was made to East Tank Farms Operations concerning low hydroxide in the tank and a hydroxide (caustic) demand analysis was requested. The request for sample analysis (RSA) (Attachment 2) received for AP-107 indicated that the samples were polychlorinated biphenyl (PCB) suspects. Therefore, prior to performing the requested analyses, aliquots were made to perform PCB analysis in accordance with the 222-S Laboratory administrative procedure, LAP-101-100. The results of this analysis indicated that no PCBs were present at 50 ppm and analysis proceeded as non-PCB samples. The results and raw data for the PCB analysis will be included in a revision to this document. The sample breakdown diagrams (Attachment 1) are provided as a cross-reference for relating the tank farm customer identification numbers with the 222-S Laboratory sample numbers and the portion of sample analyzed.

  10. Automated Plasma Spray (APS) process feasibility study

    NASA Technical Reports Server (NTRS)

    Fetheroff, C. W.; Derkacs, T.; Matay, I. M.

    1981-01-01

    An automated plasma spray (APS) process was developed to apply two layer (NiCrAlY and ZrO2-12Y2O3) thermal barrier coatings to aircraft and stationary gas turbine engine blade airfoils. The APS process hardware consists of four subsystems: a mechanical positioning subsystem incorporating two interlaced six degree of freedom assemblies (one for coating deposition and one for coating thickness monitoring); a noncoherent optical metrology subsystem (for in process gaging of the coating thickness buildup at specified points on the specimen); a microprocessor based adaptive system controller (to achieve the desired overall thickness profile on the specimen); and commerical plasma spray equipment. Over fifty JT9D first stage aircraft turbine blade specimens, ten W501B utility turbine blade specimens and dozens of cylindrical specimens were coated with the APS process in preliminary checkout and evaluation studies. The best of the preliminary turbine blade specimens achieved an overall coating thickness uniformity of 53 micrometers (2.1 mils), much better than is achievable manually. Comparative evaluations of coating thickness uniformity for manually sprayed and APS coated specimens were performed. One of the preliminary turbine blade evaluation specimens was subjected to a torch test and metallographic evaluation. Some cylindrical specimens coated with the APS process survived up to 2000 cycles in subsequent burner rig testing.

  11. Building an AP Social Studies Program with Non-Traditional AP Students

    ERIC Educational Resources Information Center

    Ashmead, Amanda; Blanchette, Sue

    2013-01-01

    Equal access to education, that is to a high quality education, has increasingly come to mean access to an Advanced Placement program. In recent years, there has been steady attention paid to opening access to AP programs. The 9th annual College Board report (2013) stated "students who succeed on an AP Exam during high school typically…

  12. Laa1p, a Conserved AP-1 Accessory Protein Important for AP-1 Localization in Yeast

    PubMed Central

    Fernández, G. Esteban

    2006-01-01

    AP-1 and Gga adaptors participate in clathrin-mediated protein transport between the trans-Golgi network and endosomes. Both adaptors contain homologous domains that act to recruit accessory proteins involved in clathrin-coated vesicle formation, but the spectrum of known adaptor-binding partners is limited. This study describes an evolutionarily conserved protein of Saccharomyces cerevisiae, Laa1p (Yjl207cp), that interacts and functions specifically with AP-1. Deletion of LAA1, when combined with a conditional mutation in clathrin heavy chain or deletion of GGA genes, accentuated growth defects and increased disruption of clathrin-dependent α-factor maturation and transport of carboxypeptidase Y to the vacuole. In contrast, such genetic interactions were not observed between deletions of LAA1 and AP-1 subunit genes. Laa1p preferentially interacted with AP-1 compared with Gga proteins by glutathione S-transferase-fusion affinity binding and coimmunoprecipitations. Localization of AP-1 and Laa1p, but not Gga proteins, was highly sensitive to brefeldin A, an inhibitor of ADP-ribosylation factor (Arf) activation. Importantly, deletion of LAA1 caused mislocalization of AP-1, especially in cells at high density (postdiauxic shift), but it did not affect Gga protein distribution. Our results identify Laa1p as a new determinant of AP-1 localization, suggesting a model in which Laa1p and Arf cooperate to direct stable association of AP-1 with appropriate intracellular membranes. PMID:16687571

  13. Ectopic expression of FaesAP3, a Fagopyrum esculentum (Polygonaceae) AP3 orthologous gene rescues stamen development in an Arabidopsis ap3 mutant.

    PubMed

    Fang, Zheng-wu; Qi, Rui; Li, Xiao-fang; Liu, Zhi-xiong

    2014-10-25

    Arabidopsis thaliana APETALA3 (AP3) and Antirrhinum majus DEFICIENS (DEF) MADS box genes are required to specify petal and stamen identity. AP3 and DEF are members of the euAP3 lineage, which arose by gene duplication coincident with radiation of the core eudicots. In order to investigate the molecular mechanisms underlying organ development in early diverging clades of core eudicots, we isolated and identified an AP3 homolog, FaesAP3, from Fagopyrum esculentum (buckwheat, Polygonaceae), a multi-food-use pseudocereal with healing benefits. Protein sequence alignment and phylogenetic analyses revealed that FaesAP3 grouped into the euAP3 lineage. Expression analysis showed that FaesAP3 was transcribed only in developing stamens, and differed from AP3 and DEF, which expressed in developing petals and stamens. Moreover, ectopic expression of FaesAP3 rescued stamen development without complementation of petal development in an Arabidopsis ap3 mutant. Our results suggest that FaesAP3 is involved in the development of stamens in buckwheat. These results also suggest that FaesAP3 holds some potential for biotechnical engineering to create a male sterile line of F. esculentum. PMID:25149019

  14. Streptolysin-O induces release of glycosylphosphatidylinositol-anchored alkaline phosphatase from ROS cells by vesiculation independently of phospholipase action.

    PubMed Central

    Xie, M; Low, M G

    1995-01-01

    Streptolysin-O (SLO), a cholesterol-binding agent, was used for studies on the release of glycosylphosphatidylinositol (GPI)-anchored alkaline phosphatase (AP) from ROS cells. Treatment of cells with SLO resulted in a time- and concentration-dependent release of AP into the extracellular medium. This release was potentiated by Ca2+ and bovine serum, but not by GPI-specific phospholipase D (GPI-PLD) purified from bovine serum. The released AP distributed to the detergent phase after Triton X-114 phase separation. This result suggested that the released AP contained an intact GPI anchor, and thus both proteolysis and anchor degradation by anchor-specific hydrolases, including GPI-PLD, as the potential mechanisms for SLO-mediated AP release were ruled out. The released AP sedimented at 100,000 g. A substantial amount of lipids was detected in the 100,000 g pellet. Cholesterol and sphingomyelin were enriched in SLO-released material, compared with intact cells. These results were consistent with vesiculation as the mechanism for SLO induction of AP release. Two other cholesterol-binding agents, saponin and digitonin, were also able to release AP, possibly by a similar vesiculation mechanism, whereas others, including nystatin, filipin and beta-escin, failed to elicit any AP release. Eight GPI-anchored proteins were identified in ROS cells, and all were substantially enriched in the vesicles released by SLO. Taken together, these results do not provide any support for the hypothesis that the clustering of GPI-anchored proteins in the plasma membrane is responsible for their resistance to GPI-PLD cleavage. Images Figure 5 Figure 6 PMID:7832771

  15. Joint effect of phosphorus limitation and temperature on alkaline phosphatase activity and somatic growth in Daphnia magna.

    PubMed

    Wojewodzic, Marcin W; Kyle, Marcia; Elser, James J; Hessen, Dag O; Andersen, Tom

    2011-04-01

    Alkaline phosphatase (AP) is a potential biomarker for phosphorus (P) limitation in zooplankton. However, knowledge about regulation of AP in this group is limited. In a laboratory acclimation experiment, we investigated changes in body AP concentration for Daphnia magna kept for 6 days at 10, 15, 20 and 25 °C and fed algae with 10 different molar C:P ratios (95-660). In the same experiment, we also assessed somatic growth of the animals since phosphorus acquisition is linked to growth processes. Overall, non-linear but significant relationships of AP activity with C:P ratio were observed, but there was a stronger impact of temperature on AP activity than of P limitation. Animals from the lowest temperature treatment had higher normalized AP activity, which suggests the operation of biochemical temperature compensation mechanisms. Body AP activity increased by a factor of 1.67 for every 10 °C decrease in temperature. These results demonstrate that temperature strongly influences AP expression. Therefore, using AP as a P limitation marker in zooplankton needs to consider possible confounding effects of temperature. Both temperature and diet affected somatic growth. The temperature effect on somatic growth, expressed as the Q (10) value, responded non-linearly with C:P, with Q(10) ranging between 1.9 for lowest food C:P ratio and 1.4 for the most P-deficient food. The significant interaction between those two variables highlights the importance of studying temperature-dependent changes of growth responses to food quality. PMID:21153741

  16. Comparative study on oxidative treatments of NAPL containing chlorinated ethanes and ethenes using hydrogen peroxide and persulfate in soils.

    PubMed

    Ko, Saebom; Crimi, Michelle; Marvin, Bruce K; Holmes, Victor; Huling, Scott G

    2012-10-15

    The goal of this study was to assess the oxidation of NAPL in soil, 30% of which were composed of chlorinated ethanes and ethenes, using catalyzed hydrogen peroxide (CHP), activated persulfate (AP), and H(2)O(2)-persulfate (HP) co-amendment systems. Citrate, a buffer and iron ligand, was amended to the treatment system to enhance oxidative treatment. Four activation/catalysis methods were employed: (1) oxidant only, (2) oxidant-citrate, (3) oxidant-iron(II), and (4) oxidant-citrate-iron(II). The NAPL treatment effectiveness was the greatest in the CHP reactions, the second in HP, and the third in AP. The effective activation and catalysis methods depended on the oxidant types; oxidant only for CHP and HP and oxidant-citrate-iron for AP. The treatability trend of chlorinated ethanes and ethenes in the soil mixture was as follows: trichloroethene > tetrachloroethene > dichloroethane > trichloroethane > tetrachloroethane. A significant fraction of persulfate remained in the oxidation systems after the 2-day reaction period, especially in the citrate-iron(II) AP. In general, oxidation systems that included citrate maintained a post-treatment pH in the range of 7-9. A final pH of AP oxidation systems was acidic (pH 2-3), where a molar ratio of citrate-iron(II) was less than 1.8 and where no citrate was amended. PMID:22658989

  17. Plyler Prize and APS Fellow Introductions

    NASA Astrophysics Data System (ADS)

    Nathanson, Gilbert

    2014-03-01

    The Division of Chemical Physics is delighted to announce the 2013 APS Fellows sponsored by DCP and to honor the 2014 Earl K. Plyler Prize Award winner. The new APS Fellows are: Ilan Benjamin, Hua Guo, Manos Mavrikakis, Josef Paldus, Joern Siepmann, Hans-Peter Steinrueck, Douglas Tobias, Angela Wilson, and Yijing Yan. The citations for each awardee will be read out loud. I will also introduce Prof. Lai-Sheng Wang of the Department of Chemistry at Brown University, who was awarded the 2014 Plyler Prize for Molecular Spectroscopy and Dynamics. Please come learn about these extraordinary scientists during this prize session. Prof. Wang's Plyler Prize talk will follow immediately after this introduction. For more information, see http://www.aps.org/units/dcp/.

  18. Self-Assembly of Uranyl-Peroxide Nanocapsules in Basic Peroxidic Environments.

    PubMed

    Miró, Pere; Vlaisavljevich, Bess; Gil, Adria; Burns, Peter C; Nyman, May; Bo, Carles

    2016-06-13

    A wide range of uranyl-peroxide nanocapsules have been synthesized using very simple reactants in basic media; however, little is known about the process to form these species. We have performed a density functional theory study of the speciation of the uranyl ions under different experimental conditions and explored the formation of dimeric species via a ligand exchange mechanism. We shed some light onto the importance of the excess of peroxide and alkali counterions as a thermodynamic driving force towards the formation of larger uranyl-peroxide species. PMID:27165671

  19. Process for extracting technetium from alkaline solutions

    SciTech Connect

    Moyer, B.A.; Sachleben, R.A.; Bonnesen, P.V.

    1994-12-31

    This invention relates generally to a process for extracting technetium from nuclear wastes and more particularly to a process for extracting technetium from alkaline waste solutions containing technetium and high concentrations of alkali metal nitrates. A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate comprises the steps of: contacting the aqueous alkaline solution with a solvent consisting of a crown ether in a diluent, the diluent being a water-immiscible organic liquid in which the crown ether is soluble, for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution into the solvent; separating the solvent containing the technetium values from the aqueous alkaline solution; and stripping the technetium values from the solvent by contacting the solvent with water.

  20. On the periodic variations of geomagnetic activity indices Ap and ap

    NASA Astrophysics Data System (ADS)

    Schreiber, H.

    1998-05-01

    Yearly averages of geomagnetic activity indices Ap for the years 1967-1984 are compared to the respective averages of 2·Bs, where v is the solar wind velocity and Bs is the southward interplanetary magnetic field (IMF) component. The correlation of both quantities is known to be rather good. Comparing the averages of Ap with 2 and Bs separately we find that, during the declining phase of the solar cycle, 2 and during the ascending phase Bs have more influence on Ap. According to this observation (using Fourier spectral analysis) the semiannual and 27 days, Ap variations for the years 1932-1993 were analysed separately for years before and after sunspot minima. Only those time-intervals before sunspot minima with a significant 27-day recurrent period of the IMF sector structure and those intervals after sunspot minima with a significant 28-28.5-day recurrent period of the sector structure were used. The averaged spectra of the two Ap data sets clearly show a period of 27 days before and a period of 28-29 days after sunspot minimum. Moreover, the phase of the average semiannual wave of Ap is significantly different for the two groups of data: the Ap variation maximizes near the equinoxes during the declining phase of the sunspot cycle and near the beginning of April and October during the ascending phase of the sunspot cycle, as predicted by the Russell-McPherron (R-M) mechanism. Analysing the daily variation of ap in an analogue manner, the same equinoctial and R-M mechanisms are seen, suggesting that during phases of the solar cycle, when ap depends more on the IMF-Bs component, the R-M mechanism is predominant, whereas during phases when ap increases as v increases the equinoctial mechanism is more likely to be effective.

  1. Singlet-Oxygen Generation in Alkaline Periodate Solution.

    PubMed

    Bokare, Alok D; Choi, Wonyong

    2015-12-15

    A nonphotochemical generation of singlet oxygen ((1)O2) using potassium periodate (KIO4) in alkaline condition (pH > 8) was investigated for selective oxidation of aqueous organic pollutants. The generation of (1)O2 was initiated by the spontaneous reaction between IO4(-) and hydroxyl ions, along with a stoichiometric conversion of IO4(-) to iodate (IO3(-)). The reactivity of in-situ-generated (1)O2 was monitored by using furfuryl alcohol (FFA) as a model substrate. The formation of (1)O2 in the KIO4/KOH system was experimentally confirmed using electron spin resonance (ESR) measurements in corroboration with quenching studies using azide as a selective (1)O2 scavenger. The reaction in the KIO4/KOH solution in both oxic and anoxic conditions initiated the generation of superoxide ion as a precursor of the singlet oxygen (confirmed by using superoxide scavengers), and the presence of molecular oxygen was not required as a precursor of (1)O2. Although hydrogen peroxide had no direct influence on the FFA oxidation process, the presence of natural organic matter, such as humic and fulvic acids, enhanced the oxidation efficiency. Using the oxidation of simple organic diols as model compounds, the enhanced (1)O2 formation is attributed to periodate-mediated oxidation of vicinal hydroxyl groups present in humic and fulvic constituent moieties. The efficient and simple generation of (1)O2 using the KIO4/KOH system without any light irradiation can be employed for the selective oxidation of aqueous organic compounds under neutral and near-alkaline conditions. PMID:26594871

  2. Alkaline-resistance model of subtilisin ALP I, a novel alkaline subtilisin.

    PubMed

    Maeda, H; Mizutani, O; Yamagata, Y; Ichishima, E; Nakajima, T

    2001-05-01

    The alkaline-resistance mechanism of the alkaline-stable enzymes is not yet known. To clarify the mechanism of alkaline-resistance of alkaline subtilisin, structural changes of two typical subtilisins, subtilisin ALP I (ALP I) and subtilisin Sendai (Sendai), were studied by means of physicochemical methods. Subtilisin NAT (NAT), which exhibits no alkaline resistance, was examined as a control. ALP I gradually lost its activity, accompanied by protein degradation, but, on the contrary, Sendai was stable under alkaline conditions. CD spectral measurements at neutral and alkaline pH indicated no apparent differences between ALP I and Sendai. A significant difference was observed on measurement of fluorescence emission spectra of the tryptophan residues of ALP I that were exposed on the enzyme surface. The fluorescence intensity of ALP I was greatly reduced under alkaline conditions; moreover, the reduction was reversed when alkaline-treated ALP I was neutralized. The fluorescence spectrum of Sendai remained unchanged. The enzymatic and optical activities of NAT were lost at high pH, indicating a lack of functional and structural stability in an alkaline environment. Judging from these results, the alkaline resistance is closely related to the surface structure of the enzyme molecule. PMID:11328588

  3. ap-9-(meta-tert-butylphenyl)fluorene.

    PubMed

    Robinson, Paul D; McLean, Aaron W; Meyers, Cal Y

    2003-10-01

    The title compound, C(23)H(22), (I), crystallizes in an ap conformationThe designations sp (synperiplanar) and ap (antiperiplanar) for these fluorene rotamers are in accordance with Rule E-6.6, IUPAC Tentative Rules, Section E, Fundamental Stereochemistry [J. Org. Chem. (1970), 35, 2861]. and its melt readily recrystallizes on cooling, in contrast to the corresponding 9-fluorenol compound, (II), which is sp and which melts without decomposition and fails to recrystallize over a long period. Both of these differences are ascribed to the intermolecular hydrogen bonding in (II), which is absent in (I) and which leads to distinctly different molecular packing in the two compounds. PMID:14532663

  4. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, R.; Randhava, S.S.; Tsai, S.P.

    1997-09-02

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H{sub 2}O{sub 2} laden permeate. 1 fig.

  5. 21 CFR 173.356 - Hydrogen peroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogen peroxide. 173.356 Section 173.356 Food... DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Specific Usage Additives § 173.356...

  6. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, Rathin; Randhava, Sarabjit S.; Tsai, Shih-Perng

    1997-01-01

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H.sub.2 O.sub.2 laden permeate.

  7. Coordination sphere of the third metal site is essential to the activity and metal selectivity of alkaline phosphatases.

    PubMed

    Koutsioulis, Dimitris; Lyskowski, Andrzej; Mäki, Seija; Guthrie, Ellen; Feller, Georges; Bouriotis, Vassilis; Heikinheimo, Pirkko

    2010-01-01

    Alkaline phosphatases (APs) are commercially applied enzymes that catalyze the hydrolysis of phosphate monoesters by a reaction involving three active site metal ions. We have previously identified H135 as the key residue for controlling activity of the psychrophilic TAB5 AP (TAP). In this article, we describe three X-ray crystallographic structures on TAP variants H135E and H135D in complex with a variety of metal ions. The structural analysis is supported by thermodynamic and kinetic data. The AP catalysis essentially requires octahedral coordination in the M3 site, but stability is adjusted with the conformational freedom of the metal ion. Comparison with the mesophilic Escherichia coli, AP shows differences in the charge transfer network in providing the chemically optimal metal combination for catalysis. Our results provide explanation why the TAB5 and E. coli APs respond in an opposite way to mutagenesis in their active sites. They provide a lesson on chemical fine tuning and the importance of the second coordination sphere in defining metal specificity in enzymes. Understanding the framework of AP catalysis is essential in the efforts to design even more powerful tools for modern biotechnology. PMID:19916164

  8. The effect of hydrogen peroxide on uranium oxide films on 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Wilbraham, Richard J.; Boxall, Colin; Goddard, David T.; Taylor, Robin J.; Woodbury, Simon E.

    2015-09-01

    For the first time the effect of hydrogen peroxide on the dissolution of electrodeposited uranium oxide films on 316L stainless steel planchets (acting as simulant uranium-contaminated metal surfaces) has been studied. Analysis of the H2O2-mediated film dissolution processes via open circuit potentiometry, alpha counting and SEM/EDX imaging has shown that in near-neutral solutions of pH 6.1 and at [H2O2] ⩽ 100 μmol dm-3 the electrodeposited uranium oxide layer is freely dissolving, the associated rate of film dissolution being significantly increased over leaching of similar films in pH 6.1 peroxide-free water. At H2O2 concentrations between 1 mmol dm-3 and 0.1 mol dm-3, formation of an insoluble studtite product layer occurs at the surface of the uranium oxide film. In analogy to corrosion processes on common metal substrates such as steel, the studtite layer effectively passivates the underlying uranium oxide layer against subsequent dissolution. Finally, at [H2O2] > 0.1 mol dm-3 the uranium oxide film, again in analogy to common corrosion processes, behaves as if in a transpassive state and begins to dissolve. This transition from passive to transpassive behaviour in the effect of peroxide concentration on UO2 films has not hitherto been observed or explored, either in terms of corrosion processes or otherwise. Through consideration of thermodynamic solubility product and complex formation constant data, we attribute the transition to the formation of soluble uranyl-peroxide complexes under mildly alkaline, high [H2O2] conditions - a conclusion that has implications for the design of both acid minimal, metal ion oxidant-free decontamination strategies with low secondary waste arisings, and single step processes for spent nuclear fuel dissolution such as the Carbonate-based Oxidative Leaching (COL) process.

  9. Crocidolite-induced lipid peroxidation. II. Role of antioxidants

    SciTech Connect

    Gulumian, M.; Kilroe-Smith, T.A.

    1987-12-01

    Asbestos fibers in vitro produce lipid peroxidation in rat lung microsomes. Butylated hydroxytoluene prevented this peroxidation. Ascorbate in low concentrations enhanced peroxidation of lipids but inhibited it at concentrations above 4 mmole/liter so that it partially protected membrane lipids from peroxidation produced by asbestos fibers. Reduced glutathione added to microsomes gave increased peroxidation at increased concentrations up to 20 mmol/liter. At 40 mmol/liter peroxidation was prevented. Glutathione had no obvious effect on the level of peroxidation produced by asbestos fibers. The 105,000g supernatant cell fraction added either with or without glutathione gave a decrease in the amount of lipid peroxidation produced by asbestos fibers. The protective action of these reducing agents suggests a possible use as prophylactic agents against the harmful effects of inhaled asbestos.

  10. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the ORGANIC... background on the ORGANIC PEROXIDE placard must be red in the top half and yellow in the lower half. The...

  11. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the ORGANIC... background on the ORGANIC PEROXIDE placard must be red in the top half and yellow in the lower half. The...

  12. Systems and methods for generation of hydrogen peroxide vapor

    DOEpatents

    Love, Adam H; Eckels, Joel Del; Vu, Alexander K; Alcaraz, Armando; Reynolds, John G

    2014-12-02

    A system according to one embodiment includes a moisture trap for drying air; at least one of a first container and a second container; and a mechanism for at least one of: bubbling dried air from the moisture trap through a hydrogen peroxide solution in the first container for producing a hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above a hydrogen peroxide solution in the second container for producing a hydrogen peroxide vapor. A method according one embodiment includes at least one of bubbling dried air through a hydrogen peroxide solution in a container for producing a first hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above the hydrogen peroxide solution in a container for producing a second hydrogen peroxide vapor. Additional systems and methods are also presented.

  13. Structural diversity and chemical synthesis of peroxide and peroxide-derived polyketide metabolites from marine sponges.

    PubMed

    Norris, Matthew D; Perkins, Michael V

    2016-07-28

    Covering: up to early 2016Marine sponges are widely known as a rich source of natural products, especially of polyketide origin, with a wealth of chemical diversity. Within this vast collection, peroxide and peroxide-derived secondary metabolites have attracted significant interest in the fields of natural product isolation and chemical synthesis for their structural distinction and promising in vitro antimicrobial and anticancer properties. In this review, peroxide and peroxide-derived polyketide metabolites isolated from marine sponges in the past 35 years are summarised. Efforts toward their synthesis are detailed with a focus on methods that utilise or attempt to elucidate the complex biosynthetic interrelationships of these compounds beyond enzymatic polyketide synthesis. Recent isolations, advances in synthetic methodology and theories of biogenesis are highlighted and critically evaluated. PMID:27163115

  14. The Relationship Between Reticulated Platelets, Intestinal Alkaline Phosphatase, and Necrotizing Enterocolitis

    PubMed Central

    Kampanatkosol, Richard; Thomson, Tricia; Habeeb, Omar; Glynn, Loretto; DeChristopher, Phillip J; Yong, Sherri; Jeske, Walter; Maheshwari, Akhil; Muraskas, Jonathan

    2015-01-01

    Background Necrotizing enterocolitis (NEC) affects up to 10% of extremely-low-birthweight infants, with a 30% mortality rate. Currently, no biomarker reliably facilitates early diagnosis/prevention. Since thrombocytopenia and bowel ischemia are consistent findings in advanced NEC, we prospectively investigated the impact of two potential biomarkers: reticulated platelets (RP) and intestinal alkaline phosphatase (iAP). Methods Infants born ≤32 weeks and/or ≤1500g were prospectively enrolled from 2009–2012. Starting within 72 hours of birth, 5 weekly whole blood specimens were collected to measure RP and serum iAP. Additional specimens were obtained at NEC onset (Bell stage II or III) and 24 hours later. Dichotomous cut-points for both biomarkers sought to maximize sensitivity. The Mann-Whitney U test highlighted differences in median biomarker levels between NEC and non-NEC infants. Chi-square or Fisher’s exact test highlighted categorical differences. The Kaplan-Meier method and Logrank test estimated the probability of developing NEC. The Cox proportional hazards model estimated hazard ratios. Results Of 177 infants, 8.5% developed NEC. Of these, 40% required surgery, 20% expired before discharge, 93% had “low” RP (≤2.3%), and 60% had high iAP (>0 U/L). Infants with “low” RP were significantly more likely to develop NEC [HR=11.0 (1.4–83); p=0.02], while those with “high” iAP showed a similar trend [HR=5.2 (0.7–42); p=0.12]. Median iAP levels were significantly higher at week 4 (p=0.02), preceding the average time to NEC onset by one week (35.7 ± 17.3 days). Conclusion Decreased RP serves as a sensitive marker for NEC onset, thereby enabling early preventative strategies. iAP overexpression may signal NEC development. PMID:24528965

  15. Synthesis and asymmetric resolution of α-azido-peroxides.

    PubMed

    Pramanik, Suman; Ghorai, Prasanta

    2013-08-01

    An unprecedented synthesis of α-azido-peroxides has been developed using an FeCl3-catalyst starting from carbonyl, TMS-azide, and hydroperoxide. Further, a base promoted decomposition of synthesized secondary α-azido-peroxides to provide the corresponding tert-butyl esters has been disclosed. Finally, an asymmetric kinetic resolution of such α-azido-peroxides has also been developed to provide chiral α-azido-peroxides in excellent enantiopurity. PMID:23855809

  16. Neodymium uranyl peroxide synthesis by ion exchange on ammonium uranyl peroxide nanoclusters.

    PubMed

    Blanchard, F; Ellart, M; Rivenet, M; Vigier, N; Hablot, I; Morel, B; Grandjean, S; Abraham, F

    2016-03-11

    This study demonstrates the ability of ammonium uranyl peroxide nanoclusters U32R-NH4 to undergo exchange in between NH4(+) and trivalent (Nd(3+)) or tetravalent (Th(4+)) cations in the solid state. It paves the way for new promising routes for the synthesis of mixed uranyl peroxides. The exchange ability may also be considered for solution decontamination and synthesis of new mixed actinide-oxide precursors. Both of these applications could be used in the nuclear industry. PMID:26879486

  17. Expanding the crystal chemistry of uranyl peroxides: four hybrid uranyl-peroxide structures containing EDTA.

    PubMed

    Qiu, Jie; Ling, Jie; Sieradzki, Claire; Nguyen, Kevin; Wylie, Ernest M; Szymanowski, Jennifer E S; Burns, Peter C

    2014-11-17

    The first four uranyl peroxide compounds containing ethylenediaminetetra-acetate (EDTA) were synthesized and characterized from aqueous uranyl peroxide nitrate solutions with a pH range of 5-7. Raman spectra demonstrated that reaction solutions that crystallized [NaK15[(UO2)8(O2)8(C10H12O10N2)2(C2O4)4]·(H2O)14] (1) and [Li4K6[(UO2)8(O2)6(C10H12O10N2)2(NO3)6]·(H2O)26] (2) contained excess peroxide, and their structures contained oxidized ethylenediaminetetraacetate, EDTAO2(4-). The solutions from which [K4[(UO2)4(O2)2(C10H13O8N2)2(IO3)2]·(H2O)16] (3) and LiK3[(UO2)4(O2)2(C10H12O8N2)2(H2O)2]·(H2O)18 (4) crystallized contained no free peroxide, and the structures incorporated intact EDTA(4-). In contrast to the large family of uranyl peroxide cage clusters, coordination of uranyl peroxide units in 1-4 by EDTA(4-) or EDTAO2(4-) results in isolated tetramers or dimers of uranyl ions that are bridged by bidentate peroxide groups. Two tetramers are bridged by EDTAO2(4-) to form octamers in 1 and 2, and dimers of uranyl polyhedra are linked through iodate groups in 3 and EDTA(4-) in 4, forming chains in both cases. In each structure the U-O2-U dihedral angle is strongly bent, at ∼140°, consistent with the configuration of this linkage in cage clusters and other recently reported uranyl peroxides. PMID:25350361

  18. Comparative Enzymology in the Alkaline Phosphatase Superfamily to Determine the Catalytic Role of an Active Site Metal Ion

    PubMed Central

    Zalatan, Jesse G.; Fenn, Timothy D.; Herschlag, Daniel

    2009-01-01

    Mechanistic models for biochemical systems are frequently proposed from structural data. Site-directed mutagenesis can be used to test the importance of proposed functional sites, but these data do not necessarily indicate how these sites contribute to function. Herein we apply an alternative approach to the catalytic mechanism of alkaline phosphatase (AP), a widely-studied, prototypical bimetallo enzyme. A third metal ion site in AP has been suggested to provide general base catalysis, but comparison with an evolutionarily-related enzyme casts doubt on this model. Removal of this metal site from AP has large differential effects on reactions of cognate and promiscuous substrates, and the results are inconsistent with general base catalysis. Instead, these and additional results suggest that the third metal ion stabilizes the transferred phosphoryl group in the transition state. These results establish a new mechanistic model for this prototypical bimetallo enzyme and demonstrate the power of a comparative approach for probing biochemical function. PMID:18851975

  19. Structuring the AP Art History Course

    ERIC Educational Resources Information Center

    Herscher, Walter R.

    2013-01-01

    While AP (Advanced Placement) Art History may be taught within the art department in many schools, social studies teachers are equally capable of teaching the course well. They have the historical background to discuss the reasons for changes in art styles. A teacher's preparation is similar to teaching a course stressing political history,…

  20. APS deposition facility upgrades and future plans

    NASA Astrophysics Data System (ADS)

    Conley, Ray; Shi, Bing; Erdmann, Mark; Izzo, Scott; Assoufid, Lahsen; Goetze, Kurt; Mooney, Tim; Lauer, Kenneth

    2014-09-01

    The Advanced Photon Source (APS) has recently invested resources to upgrade or replace aging deposition systems with modern equipment. Of the three existing deposition systems, one will receive an upgrade, while two are being replaced. A design which adds a three-substrate planetary for the APS rotary deposition system is almost complete. The replacement for the APS large deposition system, dubbed the "Modular Deposition System", has been conceptually designed and is in the procurement process. Eight cathodes will sputter horizontally on mirrors up to 1.5 meters in length. This new instrument is designed to interface with ion-milling instruments and various metrology equipment for ion-beam figuring. A third linear machine, called the APS Profile Coating System, has two cathodes and is designed to accept substrates up to 200mm in length. While this machine is primarily intended for fabrication of figured KB mirrors using the profile-coating technique, it has also been used to produce multilayer monochromators for beamline use.

  1. The AP Descriptive Chemistry Question: Student Errors

    ERIC Educational Resources Information Center

    Crippen, Kent; Brooks, David W.

    2005-01-01

    For over a decade, the authors have been involved in a design theory experiment providing software for high school students preparing for the descriptive question on the Advanced Placement (AP) chemistry examination. Since 1997, the software has been available as a Web site offering repeatable practice. This study describes a 4-year project during…

  2. The Promise of AP World History

    ERIC Educational Resources Information Center

    Saldaña, Cristóbal T.

    2013-01-01

    AP World History is the ideal history course. It introduces students to 10,000 years of world history, and demands critical reading, critical writing, and critical thinking skills on the part of both the teacher and the students. It requires students to build their expertise in reading their textbook, and places demands on the teacher to assign…

  3. Gapminder: An AP Human Geography Lab Assignment

    ERIC Educational Resources Information Center

    Keller, Kenneth H.

    2012-01-01

    This lesson is designed as a lab assignment for Advanced Placement (AP) Human Geography students wherein they use the popular Gapminder web site to compare levels of development in countries from different world regions. For this lesson, it is important for the teacher to practice with Gapminder before giving the assignment to students. (Contains…

  4. Boosting Black Academic Achievement and AP Enrollments

    ERIC Educational Resources Information Center

    Saunders, Terrie; Maloney, Kathy

    2005-01-01

    Minority students were about 25% of the student population at Central High School in Omaha, Nebraska, in 1995. But the composition of its honors and challenge classes did not reflect this diversity: Few minority students were taking challenge classes as underclassmen and even fewer were taking Advanced Placement (AP) courses as seniors. This paper…

  5. College Board Readies Plans for AP Audits

    ERIC Educational Resources Information Center

    Klein, Alyson

    2006-01-01

    This article describes the educators mixed reviews regarding the audit system planned by the College Board to scrutinize high school Advanced Placement courses. Teachers of AP courses are required to submit materials to the College Board proving that their course syllabuses meet the program's curricular requirements. It is the most extensive…

  6. Two Successful Approaches to Teaching AP Government

    ERIC Educational Resources Information Center

    Ladd, Brian; Stepp, Heidi

    2013-01-01

    Amador Valley High School, in Pleasanton, California, uses two unique approaches to teaching Advanced Placement Government and Politics. AP Government consists of six units: Constitutional Underpinnings; Political Behavior and Political Beliefs; Mass Media, Interest Groups, and Political Parties; Institutions of Government; Civil Liberties and…

  7. The Demographic Wave: Rethinking Hispanic AP Trends

    ERIC Educational Resources Information Center

    Edwards, Kelcey; Sawtell, Ellen

    2013-01-01

    Presented at the Advanced Placement Annual Conference (APAC) in Las Vegas, NV in July 2013. This presentation reviews new research examining the AP® experience of Hispanic graduates over the past decade. Topics include an in-depth look at the AP Spanish Language and Culture gateway hypothesis and trends in family characteristics such as parent…

  8. The separation of platinum, palladium and gold from silicate rocks by the anion exchange separation of chloro complexes after a sodium peroxide fusion: an investigation of low recoveries.

    PubMed

    Enzweiler, J; Potts, P J

    1995-10-01

    A series of experiments was undertaken to measure the recovery efficiency of platinum, palladium and gold from silicate rocks using a sodium peroxide fusion followed by anion exchange separation of the analytes as chloro complexes. Results obtained by graphite furnace atomic absorption spectrometric analysis of standard solutions prepared in dilute HCl or HCl-acidified sodium peroxide solution showed that recoveries were near quantitative. However, when standard solutions were added to an alkaline sodium peroxide solution, which was then acidified, low results were obtained for platinum and gold (46% and 76% respectively). Low and variable results were also obtained when standard solutions were added to a peridotite sample that had been dissolved by the state procedure, and in the analysis of the South African Bureau of Standards certified reference material, SARM 7. Various experiments were undertaken to investigate these low recoveries, but the reason proposed here is the formation of hydroxychloro compounds in alkaline solution which are not, on acidification with HCl, converted quantitatively to the chloro complex necessary for quantitative anion exchange separation. It is concluded that a sodium peroxide fusion followed by an anion-exchange separation does not appear to form the basis of a successful technique for the determination of platinum, palladium and gold in silicate rocks. PMID:18966370

  9. Impact of hydrogen peroxide as a soil amendment on nasturtiums

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrogen peroxide, H2O2, is a highly reactive oxidizing agent naturally occurring in plants and animals. Plants produce hydrogen peroxide to destroy either their infected plant cells or the pathogens within their cells. Hydrogen peroxide also acts as a stress signal to plants. It is approved for c...

  10. 49 CFR 172.427 - ORGANIC PEROXIDE label.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false ORGANIC PEROXIDE label. 172.427 Section 172.427... SECURITY PLANS Labeling § 172.427 ORGANIC PEROXIDE label. (a) Except for size and color, the ORGANIC... on the ORGANIC PEROXIDE label must be red in the top half and yellow in the lower half....

  11. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  12. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  13. 21 CFR 178.1005 - Hydrogen peroxide solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogen peroxide solution. 178.1005 Section 178... SANITIZERS Substances Utilized To Control the Growth of Microorganisms § 178.1005 Hydrogen peroxide solution. Hydrogen peroxide solution identified in this section may be safely used to sterilize polymeric...

  14. MEASUREMENT AND MODELING OF THE DRY DEPOSITION OF PEROXIDES

    EPA Science Inventory

    Measurements of the dry deposition velocity (Vd) of hydrogen peroxide (H2O2) and total organic peroxides (ROOH) were made during four experiments at three forested sites. Details and uncertainties associated with the measurement of peroxide...

  15. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false ORGANIC PEROXIDE placard. 172.552 Section 172.552... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the ORGANIC... background on the ORGANIC PEROXIDE placard must be red in the top half and yellow in the lower half. The...

  16. 49 CFR 172.427 - ORGANIC PEROXIDE label.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false ORGANIC PEROXIDE label. 172.427 Section 172.427... SECURITY PLANS Labeling § 172.427 ORGANIC PEROXIDE label. (a) Except for size and color, the ORGANIC... on the ORGANIC PEROXIDE label must be red in the top half and yellow in the lower half....

  17. Functional description of APS beamline front ends

    SciTech Connect

    Kuzay, T.

    1993-02-01

    Traditional synchrotron sources were designed to produce bending magnet radiation and have proven to be an essential scientific tool. Currently, a new generation of synchrotron sources is being built that will be able to accommodate a large number of insertion device (ID) and high quality bending magnet (BM) sources. One example is the 7-GeV Advanced Photon Source (APS) now under construction at Argonne National Laboratory. The research and development effort at the APS is designed to fully develop the potential of this new generation of synchrotron sources. Of the 40 straight sections in the APS storage ring, 34 will be available for IDs. The remaining six sections are reserved for the storage ring hardware and diagnostics. Although the ring incorporates 80 BMs, only 40 of them can be used to extract radiation. The accelerator hardware shadows five of these 40 bending magnets, so the maximum number of BM sources on the lattice is 35. Generally, a photon beamline consists of four functional sections. The first section is the ID or the BM, which provides the radiation source. The second section, which is immediately outside the storage ring but inside a concrete shielding tunnel, is the front end, which is designed to control, define, and/or confine the x-ray beam. In the case of the APS, the front ends are designed to confine the photon beam. The third section, just outside the concrete shielding tunnel and on the experimental floor, is the first optics enclosure, which contains optics to filter and monochromatize the photon beam. The fourth section of a beamline consists of beam transports, additional optics, and experiment stations to do the scientific investigations. This document describes only the front ends of the APS beamlines.

  18. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  19. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  20. Inorganic-organic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (Inventor)

    1978-01-01

    A flexible separator is reported for use between the electrodes of Ni-Cd and Ni-Zn batteries using alkaline electrolytes. The separator was made by coating a porous substrate with a battery separator composition. The coating material included a rubber-based resin copolymer, a plasticizer and inorganic and organic fillers which comprised 55% by volume or less of the coating as finally dried. One or more of the filler materials, whether organic or inorganic, is preferably active with the alkaline electrolyte to produce pores in the separator coating. The plasticizer was an organic material which is hydrolyzed by the alkaline electrolyte to improve conductivity of the separator coating.

  1. Process for extracting technetium from alkaline solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.

    1995-01-01

    A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

  2. Tank 241-AP-106, grab samples, 6AP-96-1 through 6AP-96-3 analytical results for the final report

    SciTech Connect

    Esch, R.A., Westinghouse Hanford

    1996-12-11

    This document is the final report for tank 241-AP-106 grab samples. This document presents the analytical results for three samples (6AP-96-1, 6AP-96-2 and 6AP-96-3) taken from riser 1 @ 150{degrees} of tank 241-AP-1 06 on September 12, 1996. Analyses were performed in accordance with the Compatibility Grab Sampling and Analysis Plan (TSAP) (Sasaki, 1996) and the Data Quality Objectives for Tank Farms Waste Compatibility Program (DQO) (Fowler, 1995).

  3. A high-performance direct formate-peroxide fuel cell with palladium-gold alloy coated foam electrodes

    NASA Astrophysics Data System (ADS)

    Li, Yinshi; He, Yaling; Yang, Weiwei

    2015-03-01

    We herein report a new type of direct formate fuel cell (DFFC) coupling an alkaline formate anode with an acid peroxide cathode (DFPFC), and its theoretical cell voltage reaches as high as 2.83 V. A proof-of-concept experimental study indicates that when using the as-proposed spontaneous-deposited PdAu foam electrodes, the DFPFC can yield an open-circuit voltage of 1.51 V and a peak power density of 331 mW cm-2 at 60 °C, which are higher than the state-of-the-art anion-exchange membrane DFFC.

  4. High-resolution analysis of Zn(2+) coordination in the alkaline phosphatase superfamily by EXAFS and x-ray crystallography.

    PubMed

    Bobyr, Elena; Lassila, Jonathan K; Wiersma-Koch, Helen I; Fenn, Timothy D; Lee, Jason J; Nikolic-Hughes, Ivana; Hodgson, Keith O; Rees, Douglas C; Hedman, Britt; Herschlag, Daniel

    2012-01-01

    Comparisons among evolutionarily related enzymes offer opportunities to reveal how structural differences produce different catalytic activities. Two structurally related enzymes, Escherichia coli alkaline phosphatase (AP) and Xanthomonas axonopodis nucleotide pyrophosphatase/phosphodiesterase (NPP), have nearly identical binuclear Zn(2+) catalytic centers but show tremendous differential specificity for hydrolysis of phosphate monoesters or phosphate diesters. To determine if there are differences in Zn(2+) coordination in the two enzymes that might contribute to catalytic specificity, we analyzed both x-ray absorption spectroscopic and x-ray crystallographic data. We report a 1.29-Å crystal structure of AP with bound phosphate, allowing evaluation of interactions at the AP metal site with high resolution. To make systematic comparisons between AP and NPP, we measured zinc extended x-ray absorption fine structure for AP and NPP in the free-enzyme forms, with AMP and inorganic phosphate ground-state analogs and with vanadate transition-state analogs. These studies yielded average zinc-ligand distances in AP and NPP free-enzyme forms and ground-state analog forms that were identical within error, suggesting little difference in metal ion coordination among these forms. Upon binding of vanadate to both enzymes, small increases in average metal-ligand distances were observed, consistent with an increased coordination number. Slightly longer increases were observed in NPP relative to AP, which could arise from subtle rearrangements of the active site or differences in the geometry of the bound vanadyl species. Overall, the results suggest that the binuclear Zn(2+) catalytic site remains very similar between AP and NPP during the course of a reaction cycle. PMID:22056344

  5. Composite seal reduces alkaline battery leakage

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Plitt, K. F.

    1965-01-01

    Composite seal consisting of rubber or plastic washers and a metal washer reduces alkaline battery leakage. Adhesive is applied to each washer interface, and the washers are held together mechanically.

  6. Technetium recovery from high alkaline solution

    DOEpatents

    Nash, Charles A.

    2016-07-12

    Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

  7. Alkaline tolerant dextranase from streptomyces anulatus

    DOEpatents

    Decker, Stephen R.; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.

    2003-01-01

    A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

  8. Evaluation of the alkaline electrolysis of zinc

    SciTech Connect

    Meisenhelder, J.H.; Brown, A.P.; Loutfy, R.O.; Yao, N.P.

    1981-05-01

    The alkaline leach and electrolysis process for zinc production is compared to the conventional acid-sulfate process in terms of both energy saving and technical merit. In addition, the potential for industrial application of the alkaline process is discussed on the basis of present market conditions, possible future zinc market scenarios, and the probability of increased secondary zinc recovery. In primary zinc production, the energy-saving potential for the alkaline process was estimated to be greater than 10%, even when significantly larger electrolysis current densities than those required for the sulfate process are used. The principal technical advantages of the alkaline process are that it can handle low-grade, high-iron-content or oxidized ores (like most of those found in the US) in a more cost- and energy-efficient manner than can the sulfate process. Additionally, in the electrowinning operation, the alkaline process should be technically superior because a dendritic or sponge deposit is formed that is amenable to automated collection without interruption of the electrolysis. Also, use of the higher current densities would result in significant capital cost reductions. Alkaline-based electrolytic recovery processes were considered for the recycling of zinc from smelter baghouse dusts and from the potential source of nickel/zinc electric-vehicle batteries. In all comparisons, an alkaline process was shown to be technically superior and, particularly for the baghouse dusts, energetically and economically superior to alternatively proposed recovery methods based on sulfate electrolysis. It is concluded that the alkaline zinc method is an important alternative technology to the conventional acid zinc process. (WHK)

  9. Stability of peroxide-containing uranyl minerals.

    PubMed

    Kubatko, Karrie-Ann Hughes; Helean, Katheryn B; Navrotsky, Alexandra; Burns, Peter C

    2003-11-14

    Minerals containing peroxide are limited to studtite, (UO2)O2(H2O)4, and metastudtite, (UO2)O2(H2O)2. High-temperature oxide-melt solution calorimetry and solubility measurements for studtite (standard enthalpy of formation at 298 kelvin is -2344.7 +/- 4.0 kilojoules per mole from the elements) establishes that these phases are stable in peroxide-bearing environments, even at low H2O2 concentrations. Natural radioactivity in a uranium deposit, or the radioactivity of nuclear waste, can create sufficient H2O2 by alpha radiolysis of water for studtite formation. Studtite and metastudtite may be important alteration phases of nuclear waste in a geological repository and of spent fuel under any long-term storage, possibly at the expense of the commonly expected uranyl oxide hydrates and uranyl silicates. PMID:14615533

  10. Materials Compatibility in High Test Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Gostowski, Rudy

    1999-01-01

    Previous ratings of the compatibility of high test hydrogen peroxide (HTP) with materials are not adequate for current needs. The goal of this work was to develop a new scheme of evaluation of compatibility of HTP with various materials. Procedures were developed to enrich commercially available hydrogen peroxide to 90% concentration and to assay the product. Reactivity testing, accelerated aging of materials and calorimetry studies were done on HTP with representative metallic and non-metallic materials. It was found that accelerated aging followed by concentration determination using refractive index effectively discriminated between different Class 2 metallic materials. Preliminary experiments using Differential Scanning Calorimetry (DSC) suggest that a calorimetry experiment is the most sensitive means to assay the compatibility of HTP with materials.

  11. An upper limit for stratospheric hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Traub, W. A.

    1984-01-01

    It has been postulated that hydrogen peroxide is important in stratospheric chemistry as a reservoir and sink for odd hydrogen species, and for its ability to interconvert them. The present investigation is concerned with an altitude dependent upper limit curve for stratospheric hydrogen peroxide, taking into account an altitude range from 21.5 to 38.0 km for January 23, 1983. The data employed are from balloon flight No. 1316-P, launched from the National Scientific Balloon Facility (NSBF) in Palestine, Texas. The obtained upper limit curve lies substantially below the data reported by Waters et al. (1981), even though the results are from the same latitude and are both wintertime measurements.

  12. Alkaline Water and Longevity: A Murine Study

    PubMed Central

    Magro, Massimiliano; Corain, Livio; Ferro, Silvia; Baratella, Davide; Bonaiuto, Emanuela; Terzo, Milo; Corraducci, Vittorino; Salmaso, Luigi; Vianello, Fabio

    2016-01-01

    The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of “deceleration aging factor” as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models. PMID:27340414

  13. Performed surfactant-optimized aqueous alkaline flood

    SciTech Connect

    Thigpen, D.R.; Lawson, J.B.; Nelson, R.C.

    1991-11-26

    This paper describes improvement in a process for recovering oil from an acidic oil reservoir by injecting an aqueous alkaline solution comprising water, sodium chloride, and alkaline material for reacting with the reservoir oil forming a petroleum acid soap to form an in-situ surfactant system. The improvement comprises: selecting a preformed cosurfactant which is soluble in both the aqueous solution and the reservoir oil and has a solubility ratio which is grater than the solubility ratio of the petroleum acid soap where the solubility ratio is the ratio of solubility in the aqueous alkaline solution to the solubility in the reservoir oil; combining with the alkaline solution an amount of the preformed cosurfactant which will result in the in-situ surfacant system having a salinity about equal to a salinity which results in minimal interfacial tension between the oil in the reservoir and the in-situ surfactant system at reservoir temperature, wherein the amount of the preformed cosurfactant is about 0.3 percent by weight in the aqueous alkaline solution; and injecting the cosurfactant-aqueous alkaline solution mixture into the reservoir to displace oil toward a fluid production location.

  14. Experimental investigation of hydrogen peroxide RF plasmas

    NASA Astrophysics Data System (ADS)

    Barni, R.; Decina, A.; Zanini, S.; D'Orazio, A.; Riccardi, C.

    2016-04-01

    This work reports a detailed experimental study of the plasma properties in low pressure RF discharges in hydrogen peroxide and a comparison with argon under the same operating conditions. H2O2 plasmas have been proposed for sterilization purposes. Electrical properties of the discharge were shown to be similar, as for the RF and DC voltages of the driving electrode. Bulk plasma volume remains stable, concentrated in an almost cylindrical region between the two facing electrodes. It was found that the electron temperature is almost uniform across the plasma and independent of the power level. This is higher than in argon discharges: T e  =  4.6  ±  0.9 eV versus T e  =  3.3  ±  1.1 eV. The plasma density increases almost linearly with the power level and a substantial negative ion component has been ruled out in hydrogen peroxide. Dissociation in the plasma gas phase was revealed by atomic hydrogen and hydroxyl radical emission in the discharge spectra. Emission from hydroxyl and atomic oxygen demonstrates that oxidizing radicals are produced by hydrogen peroxide discharges, revealing its usefulness for plasma processing other than sterilization, for instance to increase polymer film surface energy. On the other hand, argon could be considered as a candidate for the sterilization purposes due to the intense production of UV radiation.

  15. Vaporized hydrogen peroxide sterilization of freeze dryers.

    PubMed

    Johnson, J W; Arnold, J F; Nail, S L; Renzi, E

    1992-01-01

    The feasibility of using vapor hydrogen peroxide (VHP) as an alternative to steam sterilization has been examined using a pilot plant freeze dryer equipped with a prototype vapor generator. Specific objectives of the study discussed in this presentation were to: 1. Identify critical process variables affecting the lethality of VHP to Bacillus stearothermophilus spores, particularly within dead legs in the system. 2. Measure the efficacy of system degassing after sterilization. 3. Determine the effect of repeated sterilization cycles on the integrity of elastomeric components of the freeze dryer. Penetration of adequate concentrations of hydrogen peroxide vapor into small diameter piping, such as tubing connected to pressure gauges, is the most challenging aspect of VHP sterilization of freeze dryers. Prior to equipment modifications, spore strips placed within such dead legs remained positive irrespective of the number of gas/degas pulses and system pressure. Equipment modifications necessary to effect complete kill of biological indicators placed in system dead legs is discussed. Results of this study support the conclusion that vaporized hydrogen peroxide shows promise as an alternative sterilization method for freeze dryers. PMID:1474433

  16. Improvement of the skeletal and dental hypophosphatasia phenotype in Alpl-/- mice by administration of soluble (non-targeted) chimeric alkaline phosphatase.

    PubMed

    Gasque, Kellen C S; Foster, Brian L; Kuss, Pia; Yadav, Manisha C; Liu, Jin; Kiffer-Moreira, Tina; van Elsas, Andrea; Hatch, Nan; Somerman, Martha J; Millán, José Luis

    2015-03-01

    Hypophosphatasia (HPP) results from ALPL gene mutations, which lead to a deficiency of tissue-nonspecific alkaline phosphatase (TNAP), and accumulation of inorganic pyrophosphate, a potent inhibitor of mineralization that is also a natural substrate of TNAP, in the extracellular space. HPP causes mineralization disorders including soft bones (rickets or osteomalacia) and defects in teeth and periodontal tissues. Enzyme replacement therapy using mineral-targeting recombinant TNAP has proven effective in preventing skeletal and dental defects in TNAP knockout (Alpl(-/-)) mice, a model for life-threatening HPP. Here, we show that the administration of a soluble, intestinal-like chimeric alkaline phosphatase (ChimAP) improves the manifestations of HPP in Alpl(-/-) mice. Mice received daily subcutaneous injections of ChimAP at doses of 1, 8 or 16 mg/kg, from birth for up to 53 days. Lifespan and body weight of Alpl(-/-) mice were normalized, and vitamin B6-associated seizures were absent with 16 mg/kg/day of ChimAP. Radiographs, μCT and histological analyses documented improved mineralization in cortical and trabecular bone and secondary ossification centers in long bones of ChimAP16-treated mice. There was no evidence of craniosynostosis in the ChimAP16-treated mice and we did not detect ectopic calcification by radiography and histology in the aortas, stomachs, kidneys or lungs in any of the treatment groups. Molar tooth development and function improved with the highest ChimAP dose, including enamel, dentin, and tooth morphology. Cementum remained deficient and alveolar bone mineralization was reduced compared to controls, though ChimAP-treated Alpl(-/-) mice featured periodontal attachment and retained teeth. This study provides the first evidence for the pharmacological efficacy of ChimAP for use in the treatment of skeletal and dental manifestations of HPP. PMID:25433339

  17. Improvement of the skeletal and dental hypophosphatasia phenotype in Alpl−/− mice by administration of soluble (non-targeted) chimeric alkaline phosphatase

    PubMed Central

    Gasque, Kellen; Foster, Brian L.; Kuss, Pia; Yadav, Manisha C.; Liu, Jin; Kiffer-Moreira, Tina; van Elsas, Andrea; Hatch, Nan; Somerman, Martha J.; Millán, JoséLuis

    2014-01-01

    Hypophosphatasia (HPP) results from ALPL gene mutations, which lead to a deficiency of tissue-nonspecific alkaline phosphatase (TNAP), and accumulation of inorganic pyrophosphate, a potent inhibitor of mineralization that is also a natural substrate of TNAP, in the extracellular space. HPP causes mineralization disorders including soft bones (rickets or osteomalacia) and defects in teeth and periodontal tissues. Enzyme replacement therapy using mineral-targeting recombinant TNAP has proven effective in preventing skeletal and dental defects in TNAP knockout (Alpl−/−) mice, a model for life-threatening HPP. Here, we show that the administration of a soluble, intestinal-like chimeric alkaline phosphatase (ChimAP) improves the manifestations of HPP in Alpl−/− mice. Mice received daily subcutaneous injections of ChimAP at doses of 1, 8 or 16 mg/kg, from birth for up to 53 days. Lifespan and body weight of Alpl−/− mice were normalized, and vitamin B6-associated seizures were absent with 16 mg/kg/day of ChimAP. Radiographs, μCT and histological analyses documented improved mineralization in cortical and trabecular bone and secondary ossification centers in long bones of ChimAP16-treated mice. There was no evidence of craniosynostosis in the ChimAP16-treated mice and we did not detect ectopic calcification by radiography and histology in the aortas, stomachs, kidneys or lungs in any of the treatment groups. Molar tooth development and function improved with the highest ChimAP dose, including enamel, dentin, and tooth morphology. Cementum remained deficient and alveolar bone mineralization was reduced compared to controls, though ChimAP-treated Alpl−/− mice featured periodontal attachment and retained teeth. This study provides the first evidence for the pharmacological efficacy of ChimAP for use in the treatment of skeletal and dental manifestations of HPP. PMID:25433339

  18. Cultural Diversity in AP Art History

    ERIC Educational Resources Information Center

    Bolte, Frances R.

    2006-01-01

    Teaching AP Art History is like running on a treadmill that is moving faster than a teacher can run. Many teachers are out of breath before the end of the term and wonder how in the world they can cover every chapter. Because time is short and art from pre-history through to the present, including the non-European traditions, must be covered, this…

  19. An Updated AP2 Beamline TURTLE Model

    SciTech Connect

    Gormley, M.; O'Day, S.

    1991-08-23

    This note describes a TURTLE model of the AP2 beamline. This model was created by D. Johnson and improved by J. Hangst. The authors of this note have made additional improvements which reflect recent element and magnet setting changes. The magnet characteristics measurements and survey data compiled to update the model will be presented. A printout of the actual TURTLE deck may be found in appendix A.

  20. Beryllium window for an APS diagnostics beamline

    SciTech Connect

    Sheng, I.C.; Yang, B.X.; Sharma, Y.S.

    1997-09-01

    A beryllium (Be) window for an Advanced Photon Source (APS) diagnostics beamline has been designed and built. The window, which has a double concave axisymmetrical profile with a thickness of 0.5 mm at the center, receives 160 W/mm{sup 2} (7 GeV/100 mA stored beam) from an undulator beam. The window design as well as thermal and thermomechanical analyses, including thermal buckling of the Be window, are presented.

  1. APS storage ring vacuum system performance

    SciTech Connect

    Noonan, J.R.; Gagliano, J.; Goeppner, G.A.

    1997-06-01

    The Advanced Photon Source (APS) storage ring was designed to operated with 7-GeV, 100-mA positron beam with lifetimes > 20 hours. The lifetime is limited by residual gas scattering and Touschek scattering at this time. Photon-stimulated desorption and microwave power in the rf cavities are the main gas loads. Comparison of actual system gas loads and design calculations will be given. In addition, several special features of the storage ring vacuum system will be presented.

  2. Final report for tank 241-AP-108, grab samples 8AP-96-1, 8AP-96-2 and 8AP-96-FB

    SciTech Connect

    Esch, R.A.

    1996-04-19

    This document is the final report deliverable for the tank 241-AP-108 grab samples. The samples were subsampled and analyzed in accordance with the TSAP. Included in this report are the results for the Waste Compatibility analyses, with the exception of DSC and thermogravimetric analysis (TGA) results which were presented in the 45 Day report (Part 2 of this document). The raw data for all analyses, with the exception of DSC and TGA, are also included in this report.

  3. AP-42 ADDITIONS AND REVISIONS - RESIDENTIAL WOOD COMBUSTION

    EPA Science Inventory

    This project develops emission factors, etc., for residential fireplaces and woodstoves which are incorporated into AP-42. AP42 is a massive collection of material which describes processes which generate air emissions and presents emission factors and control effectiveness infor...

  4. Small Molecule Inhibitors Targeting Activator Protein 1 (AP-1)

    PubMed Central

    2015-01-01

    Activator protein 1 (AP-1) is a pivotal transcription factor that regulates a wide range of cellular processes including proliferation, apoptosis, differentiation, survival, cell migration, and transformation. Accumulating evidence supports that AP-1 plays an important role in several severe disorders including cancer, fibrosis, and organ injury, as well as inflammatory disorders such as asthma, psoriasis, and rheumatoid arthritis. AP-1 has emerged as an actively pursued drug discovery target over the past decade. Excitingly, a selective AP-1 inhibitor T-5224 (51) has been investigated in phase II human clinical trials. Nevertheless, no effective AP-1 inhibitors have yet been approved for clinical use. Despite significant advances achieved in understanding AP-1 biology and function, as well as the identification of small molecules modulating AP-1 associated signaling pathways, medicinal chemistry efforts remain an urgent need to yield selective and efficacious AP-1 inhibitors as a viable therapeutic strategy for human diseases. PMID:24831826

  5. 21 CFR 864.7660 - Leukocyte alkaline phosphatase test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Leukocyte alkaline phosphatase test. 864.7660... Leukocyte alkaline phosphatase test. (a) Identification. A leukocyte alkaline phosphatase test is a device used to identify the enzyme leukocyte alkaline phosphatase in neutrophilic granulocytes...

  6. 21 CFR 864.7660 - Leukocyte alkaline phosphatase test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Leukocyte alkaline phosphatase test. 864.7660... Leukocyte alkaline phosphatase test. (a) Identification. A leukocyte alkaline phosphatase test is a device used to identify the enzyme leukocyte alkaline phosphatase in neutrophilic granulocytes...

  7. Alkaline phosphatases contribute to uterine receptivity, implantation, decidualization and defense against bacterial endotoxin in hamsters

    PubMed Central

    Lei, Wei; Nguyen, Heidi; Brown, Naoko; Ni, Hua; Kiffer-Moreira, Tina; Reese, Jeff; Millán, José Luis; Paria, Bibhash C.

    2013-01-01

    Alkaline phosphatase (AP) activity has been demonstrated in the uterus of several species, but its importance in the uterus, in general and during pregnancy, is yet to be revealed. In this study, we focused on identifying AP isozyme types, and their hormonal regulation, cell-type and event-specific expression and possible functions in the hamster uterus during the cycle and early pregnancy. Our RT-PCR and in situ hybridization studies demonstrated that among the known Akp2, Akp3, Akp5 and Akp6 murine AP isozyme genes, hamster uteri express only Akp2 and Akp6; and both genes are co-expressed in luminal epithelial cells. Studies in cyclic and ovariectomized hamsters established that while progesterone is the major uterine Akp2 inducer, both progesterone and estrogen are strong Akp6 regulators. Studies in preimplantation uteri showed induction of both genes and the activity of their encoded isozymes in luminal epithelial cells during uterine receptivity. However, at the beginning of implantation, Akp2 showed reduced expression in luminal epithelial cells surrounding the implanted embryo. In contrast, expression of Akp6 and its isozyme was maintained in luminal epithelial cells adjacent to, but not away from, the implanted embryo. Following implantation, stromal transformation to decidua was associated with induced expressions of only Akp2 and its isozyme. We next demonstrated that uterine APs dephosphorylate and detoxify endotoxin lipopolysaccharide at their sites of production and activity. Taken together, our findings suggest that uterine APs contribute to uterine receptivity, implantation, and decidualization in addition to their role in protection of the uterus and pregnancy against bacterial infection. PMID:23929901

  8. Hydrogen peroxide excretion by oral streptococci and effect of lactoperoxidase-thiocyanate-hydrogen peroxide.

    PubMed Central

    Carlsson, J; Iwami, Y; Yamada, T

    1983-01-01

    Approved type strains of Streptococcus sanguis, S. mitis, S. mutans, and S. salivarius were grown under aerobic and anaerobic conditions. The rate of hydrogen peroxide excretion, oxygen uptake, and acid production from glucose by washed-cell suspensions of these strains were studied, and the levels of enzymes in cell-free extracts which reduced oxygen, hydrogen peroxide, or hypothiocyanite (OSCN-) in the presence of NADH or NADPH were assayed. The effects of lactoperoxidase-thiocyanate-hydrogen peroxide on the rate of acid production and oxygen uptake by intact cells, the activity of glycolytic enzymes in cell-free extracts, and the levels of intracellular glycolytic intermediates were also studied. All strains consumed oxygen in the presence of glucose. S. sanguis, S. mitis, and anaerobically grown S. mutans excreted hydrogen peroxide. There was higher NADH oxidase and NADH peroxidase activity in aerobically grown cells than in anaerobically grown cells. NADPH oxidase activity was low in all species. Acid production, oxygen uptake, and, consequently, hydrogen peroxide excretion were inhibited in all the strains by lactoperoxidase-thiocyanate-hydrogen peroxide. S. sanguis and S. mitis had a higher capacity than S. mutans and S. salivarius to recover from this inhibition. Higher activity in the former strains of an NADH-OSCN oxidoreductase, which converted OSCN- into thiocyanate, explained this difference. The change in levels of intracellular glycolytic intermediates after inhibition of glycolysis by OSCN- and the actual activity of glycolytic enzymes in cell-free extracts in the presence of OSCN- indicated that the primary target of OSCN- in the glycolytic pathway was glyceraldehyde 3-phosphate dehydrogenase. PMID:6832837

  9. Chemical equilibria in the binary and ternary uranyl(VI)-hydroxide-peroxide systems.

    PubMed

    Zanonato, Pier Luigi; Di Bernardo, Plinio; Grenthe, Ingmar

    2012-03-28

    The composition and equilibrium constants of the complexes formed in the binary U(VI)-hydroxide and the ternary U(VI)-hydroxide-peroxide systems have been studied using potentiometric and spectrophotometric data at 25 °C in a 0.100 M tetramethylammonium nitrate medium. The data for the binary U(VI) hydroxide complexes were in good agreement with previous studies. In the ternary system two complexes were identified, [UO(2)(OH)(O(2))](-) and [(UO(2))(2)(OH)(O(2))(2)](-). Under our experimental conditions the former is predominant over a broad p[H(+)] region from 9.5 to 11.5, while the second is found in significant amounts at p[H(+)] < 10.5. The formation of the ternary peroxide complexes results in a strong increase in the molar absorptivity of the test solutions. The absorption spectrum for [(UO(2))(2)(OH)(O(2))(2)](-) was resolved into two components with peaks at 353 and 308 nm with molar absorptivity of 16200 and 20300 M(-1) cm(-1), respectively, suggesting that the electronic transitions are dipole allowed. The molar absorptivity of [(UO(2))(OH)(O(2))](-) at the same wave lengths are significantly lower, but still about one to two orders of magnitude larger than the values for UO(2)(2+)(aq) and the binary uranyl(VI) hydroxide complexes. It is of interest to note that [(UO(2))(OH)(O(2))](-) might be the building block in cluster compounds such as [UO(2)(OH)(O(2))](60)(60-) studied by Burns et al. (P. C. Burns, K. A. Kubatko, G. Sigmon, B. J. Fryer, J. E. Gagnon, M. R. Antonio and L. Soderholm, Angew. Chem. 2005, 117, 2173-2177). Speciation calculations using the known equilibrium constants for the U(vi) hydroxide and peroxide complexes show that the latter are important in alkaline solutions even at very low total concentrations of peroxide, suggesting that they may be involved when the uranium minerals Studtite and meta-Studtite are formed by α-radiolysis of water. Radiolysis will be much larger in repositories for spent nuclear fuel where hydrogen peroxide

  10. Intercomparison of Chemically Independent Peroxide Observations During INTEX-NA

    NASA Astrophysics Data System (ADS)

    O'Sullivan, D. W.; Shen, H.; Heikes, B. G.; Crounse, J. D.; Kwan, A. J.; Wennberg, P. O.; Pippin, M. R.; Crawford, J. H.

    2005-12-01

    Gas phase peroxide measurements were preformed with two analytical techniques during the INTEX-NA field project. In the first method peroxides were partitioned into an aqueous phase in cyclone separators, the aqueous collection solution was injected on to an HPLC to separate hydrogen peroxide and organic peroxides. Separated peroxides were quantified by a post column derivatization reaction with p-hydroxyphenyl acetic acid and horse radish peroxidase forming a fluorescent dimer. This method is capable of identification and quantification of C1 and C2 organic peroxides. With the dual HPLC system a 30 sec integrated sample was analyzed every 90 sec. The second method employed chemical ionization mass spectrometry to quantify the peroxides via a direct gas phase ion-molecule reaction between the peroxide and a CFO3- ion. The Caltech CIMS technique makes a 0.5 sec measurement every 5 sec. Comparison of the observations of hydrogen peroxide by both techniques on the same time base results in nearly a 90% correspondence between the techniques. Both systems also quantified peroxyacetic acid (PAA) with a 72% correspondence between observations. The majority of discrepancies between the techniques occur for observations approaching the respective detection limits. The PAA observations are the first measurements for this compound in the troposphere. The specificity of the enzyme catalyzed technique for the peroxide moiety and the characteristic retention time, coupled to the unique mass number identification using CIMS lends confidence to the correct identification and quantification of PAA.

  11. 77 FR 24480 - Application for New Awards; Advanced Placement (AP) Test Fee Program-Reopening the AP Test Fee...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-24

    .... ACTION: Notice reopening the AP Test Fee fiscal year 2012 competition. Catalog of Federal Domestic Assistance (CFDA) Number: 84.330B. SUMMARY: On February 15, 2012, we published in the Federal Register (77 FR... Application for New Awards; Advanced Placement (AP) Test Fee Program--Reopening the AP Test Fee Fiscal...

  12. A kinetic and theoretical study of the borate catalysed reactions of hydrogen peroxide: the role of dioxaborirane as the catalytic intermediate for a wide range of substrates.

    PubMed

    Deary, Michael E; Durrant, Marcus C; Davies, D Martin

    2013-01-14

    Our recent work has provided new insights into the equilibria and species that exist in aqueous solution at different pHs for the boric acid - hydrogen peroxide system, and the role of these species in oxidation reactions. Most recently, (M. C. Durrant, D. M. Davies and M. E. Deary, Org. Biomol. Chem., 2011, 9, 7249-7254), we have produced strong theoretical and experimental evidence for the existence of a previously unreported monocyclic three membered peroxide species, dioxaborirane, that is the likely catalytic species in borate mediated electrophilic reactions of hydrogen peroxide in alkaline solution. In the present paper, we extend our study of the borate-peroxide system to look at a wide range of substrates that include substituted dimethyl anilines, methyl-p-tolyl sulfoxide, halides, hydrogen sulfide anion, thiosulfate, thiocyanate, and hydrazine. The unusual selectivity-reactivity pattern of borate catalysed reactions compared with hydrogen peroxide and inorganic or organic peracids previously observed for the organic sulfides (D. M. Davies, M. E. Deary, K. Quill and R. A. Smith, Chem.-Eur. J., 2005, 11, 3552-3558) is also seen with substituted dimethyl aniline nucleophiles. This provides evidence that the pattern is not due to any latent electrophilic tendency of the organic sulfides and further supports dioxaborirane being the likely reactive intermediate, thus broadening the applicability of this catalytic system. Moreover, density functional theory calculations on our proposed mechanism involving dioxaborirane are consistent with the experimental results for these substrates. Results obtained at high concentrations of both borate and hydrogen peroxide require the inclusion the diperoxodiborate dianion in the kinetic analysis. A scheme detailing our current understanding of the borate-peroxide system is presented. PMID:23188177

  13. WO3/Pt nanoparticles promote light-induced lipid peroxidation and lysosomal instability within tumor cells

    NASA Astrophysics Data System (ADS)

    Clark, Andrea J.; Petty, Howard R.

    2016-02-01

    Although metal-metal oxide nanoparticles have attracted considerable interest as catalysts, they have attracted little interest in nanomedicine. This is likely due to the fact that metal oxide semiconductors generally require biologically harmful ultraviolet excitation. In contrast, this study focuses upon WO3/Pt nanoparticles, which can be excited by visible light. To optimize the nanoparticles’ catalytic performance, platinization was performed at alkaline pH. These nanoparticles destroyed organic dyes, consumed dissolved oxygen and produced hydroxyl radicals. 4T1 breast cancer cells internalized WO3/Pt nanoparticles within the membrane-bound endo-lysosomal compartment as shown by electron and fluorescence microscopy. During visible light exposure, but not in darkness, WO3/Pt nanoparticles manufacture reactive oxygen species, promote lipid peroxidation, and trigger lysosomal membrane disruption. As cells of the immune system degrade organic molecules, produce reactive oxygen species, and activate the lipid peroxidation pathway within target cells, these nanoparticles mimic the chemical attributes of immune effector cells. These biomimetic nanoparticles should become useful in managing certain cancers, especially ocular cancer.

  14. WO3/Pt nanoparticles promote light-induced lipid peroxidation and lysosomal instability within tumor cells.

    PubMed

    Clark, Andrea J; Petty, Howard R

    2016-02-19

    Although metal-metal oxide nanoparticles have attracted considerable interest as catalysts, they have attracted little interest in nanomedicine. This is likely due to the fact that metal oxide semiconductors generally require biologically harmful ultraviolet excitation. In contrast, this study focuses upon WO3/Pt nanoparticles, which can be excited by visible light. To optimize the nanoparticles' catalytic performance, platinization was performed at alkaline pH. These nanoparticles destroyed organic dyes, consumed dissolved oxygen and produced hydroxyl radicals. 4T1 breast cancer cells internalized WO3/Pt nanoparticles within the membrane-bound endo-lysosomal compartment as shown by electron and fluorescence microscopy. During visible light exposure, but not in darkness, WO3/Pt nanoparticles manufacture reactive oxygen species, promote lipid peroxidation, and trigger lysosomal membrane disruption. As cells of the immune system degrade organic molecules, produce reactive oxygen species, and activate the lipid peroxidation pathway within target cells, these nanoparticles mimic the chemical attributes of immune effector cells. These biomimetic nanoparticles should become useful in managing certain cancers, especially ocular cancer. PMID:26788907

  15. Production and characterization of a single-chain variable fragment linked alkaline phosphatase fusion protein for detection of O,O-diethyl organophosphorus pesticides in a one-step enzyme-linked immunosorbent assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A single-chain variable fragment (scFv) and alkaline phosphatase (AP) fusion protein for detection of O, O-diethyl organophosphorus pesticides (OPs) was produced and characterized. The scFv gene was prepared by cloning VL and VH genes from a hybridoma cell secreting monoclonal antibody with broad-s...

  16. One-step Immunoassay for Tetrabromobisphenol A Using a Camelid Single Domain Antibody-Alkaline Phosphatase Fusion Protein

    PubMed Central

    Wang, Jia; Majkova, Zuzana; Bever, Candace R. S.; Yang, Jun; Gee, Shirley J.; Li, Ji; Xu, Ting; Hammock, Bruce D.

    2015-01-01

    Tetrabromobisphenol A (TBBPA) is a ubiquitous brominated flame retardant, showing widespread environment and human exposures. A variable domain of the heavy chain antibody (VHH), naturally occurring in camelids, approaches the lower size limit of functional antigen-binding entities. Ease of genetic manipulation makes such VHHs a superior choice to use as an immunoreagent. In this study, a highly selective anti-TBBPA VHH T3-15 fused with alkaline phosphatase (AP) from E. coli was expressed, showing both an integrated TBBPA-binding capacity and enzymatic activity. A one-step immunoassay based on the fusion protein T3-15-AP was developed for TBBPA in 5% dimethyl sulfoxide (DMSO)/phosphate buffered saline (PBS, pH 7.4), with a half-maximum signal inhibition concentration (IC50) of 0.20 ng mL−1. Compared to the parental VHH T3-15, T3-15-AP was able to bind to a wider variety of coating antigens and the assay sensitivity was slightly improved. Cross-reactivity of T3-15-AP with a set of important brominated analogs was negligible (<0.1%). Although T3-15-AP was susceptible to extreme heat (90 °C), much higher binding stability at ambient temperature was observed in the T3-15-AP based assay for at least 70 days. A simple pretreatment method of diluting urine samples with DMSO was developed for a one-step assay. The recoveries of TBBPA from urine samples by this one-step assay ranged from 96.7–109.9% and correlated well with an HPLC-MS/MS method. It is expected that the dimerized fusion protein, VHH-AP, will show promising applications in human exposure and environmental monitoring. PMID:25849972

  17. Hazard Assessment of Personal Protective Clothing for Hydrogen Peroxide Service

    NASA Technical Reports Server (NTRS)

    Greene, Ben; McClure, Mark B.; Johnson, Harry T.

    2004-01-01

    Selection of personal protective equipment (PPE) for hydrogen peroxide service is an important part of the hazard assessment process. But because drip testing of chemical protective clothing for hydrogen peroxide service has not been reported for about 40 years, it is of great interest to test new protective clothing materials with new, high-concentration hydrogen peroxide following similar procedures. The suitability of PPE for hydrogen peroxide service is in part determined by observations made when hydrogen peroxide is dripped onto swatches of protective clothing material. Protective clothing material was tested as received, in soiled condition, and in grossly soiled condition. Materials were soiled by pretreating the material with potassium permanganate (KMnO4) solution then drying to promote a reaction. Materials were grossly soiled with solid KMnO4 to greatly promote reaction. Observations of results including visual changes to the hydrogen peroxide and materials, times to ignition, and self-extinguishing characteristics of the materials are reported.

  18. AP600 containment purge radiological analysis

    SciTech Connect

    O`Connor, M.; Schulz, J.; Tan, C.

    1995-02-01

    The AP600 Project is a passive pressurized water reactor power plant which is part of the Design Certification and First-of-a-Kind Engineering effort under the Advanced Light Water Reactor program. Included in this process is the design of the containment air filtration system which will be the subject of this paper. We will compare the practice used by previous plants with the AP600 approach to meet the goals of industry standards in sizing the containment air filtration system. The radiological aspects of design are of primary significance and will be the focus of this paper. The AP600 Project optimized the design to combine the functions of the high volumetric flow rate, low volumetric flow rate, and containment cleanup and other filtration systems into one multi-functional system. This achieves a more simplified, standardized, and lower cost design. Studies were performed to determine the possible concentrations of radioactive material in the containment atmosphere and the effectiveness of the purge system to keep concentrations within 10CFR20 limits and within offsite dose objectives. The concentrations were determined for various reactor coolant system leakage rates and containment purge modes of operation. The resultant concentrations were used to determine the containment accessibility during various stages of normal plant operation including refueling. The results of the parametric studies indicate that a dual train purge system with a capacity of 4,000 cfm per train is more than adequate to control the airborne radioactivity levels inside containment during normal plant operation and refueling, and satisfies the goals of ANSI/ANS-56.6-1986 and limits the amount of radioactive material released to the environment per ANSI/ANS 59.2-1985 to provide a safe environment for plant personnel and offsite residents.

  19. Intermediate range order in alkaline borate glasses

    NASA Astrophysics Data System (ADS)

    Crupi, C.; Carini, G.; Ruello, G.; D'Angelo, G.

    2016-03-01

    We describe the neutron diffraction patterns of a series of alkaline borate glasses at different metal oxide content. Strong differences are observed in the intermediate range order as a function of the specific alkaline ion and of its concentration. On these results, we propose that the first sharp diffraction peak arises from correlations of atoms of voids and show that the compositional variation of this peak intensity in alkaline borate glasses is due to changes in the distribution of void sizes within the three-dimensional network. We argue that our interpretation in terms of interstitial (empty and/or filled) voids, having different sizes, provides a general explanation for all anomalous behaviours revealed for the first sharp diffraction peak.

  20. Ozone mitigation tests at the APS

    SciTech Connect

    Kuzay, T.M.; Collins, J.T.; Pisharody, M.; Job, P.K.; Wang Zhibi

    1996-09-01

    Ozone is generated in the APS experimental stations whenever the x-ray beam has a chance to interact with air. Ozone concentrations in an experimental station have to be below a certain defined limit (current OSHA regulations specify 0.08 ppm as the maximum limit) before an experimenter can reenter the hutch. This limit is said to be currently under study for a downward adjustment. One method of depleting the ozone generated in an experimental station is mitigation through either adsorption or direct destruction. In recent tests, both methods were tried using commercially available units. Test results and some analytical predictions are presented.

  1. Lipid peroxidation, calcium, iron, and TCDD toxicity in rats

    SciTech Connect

    Al-Bayati, Z.A.F.

    1986-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been studied as a prototype of halogenated aromatic hydrocarbons. Previous studies have shown that TCDD enhances hepatic lipid peroxidation. This study on TCDD administration to rats was conducted to: measure induction of lipid peroxidation in hepatic and extrahepatic tissues; compare lipid peroxidation between sexes; determine the contributions of H/sub 2/O/sub 2/ and other reactive oxygen species and associated enzymes on hepatic lipid peroxidation: determine the role of iron in TCDD-induced lipid peroxidation; and investigate the relationship between TCDD-induced alterations in lipid peroxidation, calcium homeostasis, reduced glutathione content (GSH) and selenium-dependent glutathione peroxidase activity (GSH-Px). The results demonstrated that TCDD induces changes in microsomal lipid peroxidation in hepatic and extrahepatic tissues. The rates of microsomal lipid peroxidation in male rats were less than in microsomes from female rats. TCDD treatment produced a significant increase in lipid peroxidation which preceded an increase in whole homogenate and mitochondrial calcium content, but paralleled an increase in microsomal calcium content. TCDD treatment produced dose and time dependent decreases in hepatic GSH content and GSH-Px activity in female rats. H/sub 2/O/sub 2/ and possibly hydroxyl radical and singlet oxygen are involved in TCDD-induced hepatic microsomal lipid peroxidation. The results support the hypothesis that the toxicity of TCDD and its lack of tissue selectivity in male and female rats may be due in part to lipid peroxidation. Lipid peroxidation may alter membrane permeability to calcium and lead to sequestration of calcium.

  2. Alkaline Band Formation in Chara corallina

    PubMed Central

    Lucas, William J.

    1979-01-01

    The nature of the transport system responsible for the establishment of alkaline bands on cells of Chara corallina was investigated. The transport process was found to be insensitive to external pH, provided the value was above a certain threshold. At this threshold (pH 5.1 to 4.8) the transport process was inactivated. Transport function could be recovered by raising the pH value of the external solution. The fastest rate of recovery was always obtained in the presence of exogenous HCO3−. Experiments in which plasmalemma integrity was modified using 10 millimolar K+ treatment were also performed. Alkaline band transport was significantly reduced in the presence of 10 millimolar K+, but the system did not recover, following return to 0.2 millimolar K+ solutions, until the transport site was reexposed to exogenous HCO3−. The influence of presence and absence of various cations on both alkaline band transport and total H14CO3− assimilation was examined. No specific cation requirement (mono- or divalent) was found for either process, except the previously established role of Ca2+ at the HCO3− transport site. The alkaline band transport process exhibited a general requirement for cations. This transport system could be partially or completely stalled in low cation solutions, or glass-distilled water, respectively. The results indicate that no cationic flux occurs across the plasmalemma in direct association with either the alkaline band or HCO3− transport systems. It is felt that the present results offer support for the hypothesis that an OH− efflux transport system (rather than a H+ influx system) is responsible for alkaline band development in C. corallina. The results support the hypothesis that OH− efflux is an electrogenic process. This OH− transport system also appears to contain two allosteric effector sites, involving an acidic group and a HCO3− ion. PMID:16660706

  3. Schistosoma mansoni: molecular characterization of Alkaline Phosphatase and expression patterns across life cycle stages.

    PubMed

    Araujo-Montoya, B O; Rofatto, H K; Tararam, C A; Farias, L P; Oliveira, K C; Verjovski-Almeida, S; Wilson, R A; Leite, L C C

    2011-11-01

    Here we describe the cloning and characterization of the Schistosoma mansoni Alkaline Phosphatase (SmAP), previously identified in the tegument of adult worms. SmAP encodes a complete sequence composed of 536 amino acids containing an N-terminal signal peptide, five N-glycosylation sites, and a GPI anchor signal, similar to that described for mammalian orthologs. Real-time RT-PCR and Western blot experiments suggest a rapid translation as soon as cercariae are transformed into schistosomula. Immunolocalization analysis shows that the protein is widely distributed in the worm tissues, with increased concentration in the vitelline glands of female parasites. Furthermore, the surface localization of this enzyme was quantitatively supported by its enzymatic activity in live ex vivo or cultured parasites throughout the life cycle stages. The fact that cercariae accumulate large amounts of SmAP mRNA, which rapidly translates into protein upon schistosomula transformation, indicates it may have an important role in host invasion. PMID:21784070

  4. Quantification of peroxide ion passage in dentin, enamel, and cementum after internal bleaching with hydrogen peroxide.

    PubMed

    Palo, R M; Bonetti-Filho, I; Valera, M C; Camargo, C H R; Camargo, Sea; Moura-Netto, C; Pameijer, C

    2012-01-01

    The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the

  5. Degradation of halogenated carbons in alkaline alcohol

    NASA Astrophysics Data System (ADS)

    Nakagawa, Seiko; Shimokawa, Toshinari

    2002-02-01

    1,1,2-Trichloro-trifluoroethane, 1,2-dibromo-tetrafluoroethane, 2,3,4,6-tetrachlorophenol, 1,2,4-trichlorobenzene, and 2,4,6-trichloroanisole were dissolved in alkaline isopropyl alcohol and irradiated with 60Co gamma rays after purged with pure nitrogen gas. The concentration of the hydroxide ions and the parent molecules decreased with the dose, while that of the halide ions and the organic products, with less halogen atoms than the parent, increased. Chain degradation will occur in alkaline isopropyl alcohol.

  6. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    DOEpatents

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  7. Laser direct write of planar alkaline microbatteries

    NASA Astrophysics Data System (ADS)

    Arnold, C. B.; Kim, H.; Piqué, A.

    We are developing a laser engineering approach to fabricate and optimize alkaline microbatteries in planar geometries. The laser direct-write technique enables multicapability for adding, removing and processing material and provides the ability to pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cells under ambient conditions. The microbattery cells exhibit 1.55-V open-circuit potentials, as expected for the battery chemistry, and show a flat discharge behavior under constant-current loads. High capacities of over 450 μAhcm-2 are obtained for 5-mm2 microbatteries.

  8. Alkaline Capacitors Based on Nitride Nanoparticles

    NASA Technical Reports Server (NTRS)

    Aldissi, Matt

    2003-01-01

    High-energy-density alkaline electrochemical capacitors based on electrodes made of transition-metal nitride nanoparticles are undergoing development. Transition- metal nitrides (in particular, Fe3N and TiN) offer a desirable combination of high electrical conductivity and electrochemical stability in aqueous alkaline electrolytes like KOH. The high energy densities of these capacitors are attributable mainly to their high capacitance densities, which, in turn, are attributable mainly to the large specific surface areas of the electrode nanoparticles. Capacitors of this type could be useful as energy-storage components in such diverse equipment as digital communication systems, implanted medical devices, computers, portable consumer electronic devices, and electric vehicles.

  9. Antioxidant effect of bisphosphonates and simvastatin on chondrocyte lipid peroxidation

    SciTech Connect

    Dombrecht, E.J.; De Tollenaere, C.B.; Aerts, K.; Cos, P.; Schuerwegh, A.J.; Bridts, C.H.; Van Offel, J.F.; Ebo, D.G.; Stevens, W.J. . E-mail: immuno@ua.ac.be; De Clerck, L.S.

    2006-09-22

    The objective of this study was to evaluate the effect of bisphosphonates (BPs) and simvastatin on chondrocyte lipid peroxidation. For this purpose, a flow cytometrical method using C11-BODIPY{sup 581/591} was developed to detect hydroperoxide-induced lipid peroxidation in chondrocytes. Tertiary butylhydroperoxide (t-BHP) induced a time and concentration dependent increase in chondrocyte lipid peroxidation. Addition of a Fe{sup 2+}/EDTA complex to t-BHP or hydrogen peroxide (H{sub 2}O{sub 2}) clearly enhanced lipid peroxidation. The lipophilic simvastatin demonstrated a small inhibition in the chondrocyte lipid peroxidation. None of three tested BPs (clodronate, pamidronate, and risedronate) had an effect on chondrocyte lipid peroxidation induced by t-BHP. However, when Fe{sup 2+}/EDTA complex was added to t-BHP or H{sub 2}O{sub 2}, BPs inhibited the lipid peroxidation process varying from 25% to 58%. This study demonstrates that BPs have antioxidant properties as iron chelators, thereby inhibiting the chondrocyte lipid peroxidation. These findings add evidence to the therapeutic potential of bisphosphonates and statins in rheumatoid arthritis.

  10. Use of Hydrogen Peroxide to Disinfect Hydroponic Plant Growth Systems

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Henderson, Keith

    2000-01-01

    Hydrogen peroxide was studied as an alternative to conventional bleach and rinsing methods to disinfect hydroponic plant growth systems. A concentration of 0.5% hydrogen peroxide was found to be effective. Residual hydrogen peroxide can be removed from the system by repeated rinsing or by flowing the solution through a platinum on aluminum catalyst. Microbial populations were reduced to near zero immediately after treatment but returned to pre-disinfection levels 2 days after treatment. Treating nutrient solution with hydrogen peroxide and planting directly into trays being watered with the nutrient solution without replenishment, was found to be detrimental to lettuce germination and growth.

  11. Detection of Hydrogen Peroxide by DAB Staining in Arabidopsis Leaves

    PubMed Central

    Daudi, Arsalan; O’Brien, Jose A.

    2016-01-01

    In this protocol, the in situ detection of hydrogen peroxide (one of several reactive oxygen species) is described in mature Arabidopsis rosette leaves by staining with 3,3′-diaminobenzidine (DAB) using an adaptation of previous methods (Thordal-Christensen et al., 1997; Bindschedler et al., 2006; Daudi et al., 2012). DAB is oxidized by hydrogen peroxide in the presence of some haem-containing proteins, such as peroxidases, to generate a dark brown precipitate. This precipitate is exploited as a stain to detect the presence and distribution of hydrogen peroxide in plant cells. The protocol can be modified slightly to detect hydrogen peroxide in different types of plant tissue.

  12. Synthesis and thermal properties of strontium and calcium peroxides

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H.; Kraft, Patricia A.

    1989-01-01

    A practical synthesis and a discussion of some chemical properties of pure strontium peroxide and calcium peroxide are presented. The general synthesis of these peroxides involves precipitation of their octahydrates by addition of H2O2 to aqueous ammoniacal Sr(NO3)2 or CaCl2. The octahydrates are converted to the anhydrous peroxides by various dehydration techniques. A new x-ray diffraction powder pattern for CaO2 x 8H2O is given from which lattice parameters a=6.212830 and c=11.0090 were calculated on the basis of the tetragonal crystal system.

  13. Hydrogen Peroxide Probes Directed to Different Cellular Compartments

    PubMed Central

    Malinouski, Mikalai; Zhou, You; Belousov, Vsevolod V.; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2011-01-01

    Background Controlled generation and removal of hydrogen peroxide play important roles in cellular redox homeostasis and signaling. We used a hydrogen peroxide biosensor HyPer, targeted to different compartments, to examine these processes in mammalian cells. Principal Findings Reversible responses were observed to various redox perturbations and signaling events. HyPer expressed in HEK 293 cells was found to sense low micromolar levels of hydrogen peroxide. When targeted to various cellular compartments, HyPer occurred in the reduced state in the nucleus, cytosol, peroxisomes, mitochondrial intermembrane space and mitochondrial matrix, but low levels of the oxidized form of the biosensor were also observed in each of these compartments, consistent with a low peroxide tone in mammalian cells. In contrast, HyPer was mostly oxidized in the endoplasmic reticulum. Using this system, we characterized control of hydrogen peroxide in various cell systems, such as cells deficient in thioredoxin reductase, sulfhydryl oxidases or subjected to selenium deficiency. Generation of hydrogen peroxide could also be monitored in various compartments following signaling events. Conclusions We found that HyPer can be used as a valuable tool to monitor hydrogen peroxide generated in different cellular compartments. The data also show that hydrogen peroxide generated in one compartment could translocate to other compartments. Our data provide information on compartmentalization, dynamics and homeostatic control of hydrogen peroxide in mammalian cells. PMID:21283738

  14. Monolithic Hydrogen Peroxide Catalyst Bed Development

    NASA Technical Reports Server (NTRS)

    Ponzo, J. B.

    2003-01-01

    With recent increased industry and government interest in rocket grade hydrogen peroxide as a viable propellant, significant effort has been expended to improve on earlier developments. This effort has been predominately centered in improving heterogeneous. typically catalyst beds; and homogeneous catalysts, which are typically solutions of catalytic substances. Heterogeneous catalyst beds have traditionally consisted of compressed wire screens plated with a catalytic substance, usually silver, and were used m many RCS applications (X-1, Mercury, and Centaur for example). Aerojet has devised a heterogeneous catalyst design that is monolithic (single piece), extremely compact, and has pressure drops equal to or less than traditional screen beds. The design consists of a bonded stack of very thin, photoetched metal plates, silver coated. This design leads to a high surface area per unit volume and precise flow area, resulting in high, stable, and repeatable performance. Very high throughputs have been demonstrated with 90% hydrogen peroxide. (0.60 lbm/s/sq in at 1775-175 psia) with no flooding of the catalyst bed. Bed life of over 900 seconds has also been demonstrated at throughputs of 0.60 lbm/s/sq in across varying chamber pressures. The monolithic design also exhibits good starting performance, short break-in periods, and will easily scale to various sizes.

  15. PROPULSE 980: A Hydrogen Peroxide Enrichment System

    NASA Technical Reports Server (NTRS)

    Boxwell, Robert; Bromley, G.; Wanger, Robert; Pauls, Dan; Maynard, Bryon; McNeal, Curtis; Dumbacher, D. L. (Technical Monitor)

    2000-01-01

    The PROPULSE 980 unit is a transportable processing plant that enriches aerospace grade hydrogen peroxide from 90% to 98% final concentration. The unit was developed by Degussa-H Is, in cooperation with Orbital, NASA Marshall Space Center, and NASA Stennis Space Center. The system is a self-contained unit that houses all of the process equipment, instrumentation and controls to perform the concentration operation nearly autonomously. It is designed to produce non-bulk quantities of 98% hydrogen peroxide. The enrichment unit design also maintains system, personnel and environmental safety during all aspects of the enrichment process and final product storage. As part of the Propulse 980 checkout and final buyoff, it will be disassembled at the Degussa-H Is Corporation plant in Theodore, AL, transported to the Stennis Space Center, reassembled and subjected to a series of checkout tests to verify design objectives have been met. This paper will summarize the basic project elements and provide an update on the present status of the project.

  16. Correction magnet power supplies for APS machine

    SciTech Connect

    Kang, Y.G.

    1991-04-01

    A number of correction magnets are required for the advanced photon source (APS) machine to correct the beam. There are five kinds of correction magnets for the storage ring, two for the injector synchrotron, and two for the positron accumulator ring (PAR). Table I shoes a summary of the correction magnet power supplies for the APS machine. For the storage ring, the displacement of the quadrupole magnets due to the low frequency vibration below 25 Hz has the most significant effect on the stability of the positron closed orbit. The primary external source of the low frequency vibration is the ground motion of approximately 20 {mu}m amplitude, with frequency components concentrated below 10 Hz. These low frequency vibrations can be corrected by using the correction magnets, whose field strengths are controlled individually through the feedback loop comprising the beam position monitoring system. The correction field require could be either positive or negative. Thus for all the correction magnets, bipolar power supplies (BPSs) are required to produce both polarities of correction fields. Three different types of BPS are used for all the correction magnets. Type I BPSs cover all the correction magnets for the storage ring, except for the trim dipoles. The maximum output current of the Type I BPS is 140 Adc. A Type II BPS powers a trim dipole, and its maximum output current is 60 Adc. The injector synchrotron and PAR correction magnets are powered form Type III BPSs, whose maximum output current is 25 Adc.

  17. The APS control system network upgrade.

    SciTech Connect

    Sidorowicz, K. v.; Leibfritz, D.; McDowell, W. P.

    1999-10-22

    When it was installed,the Advanced Photon Source (APS) control system network was at the state-of-the-art. Different aspects of the system have been reported at previous meetings [1,2]. As loads on the controls network have increased due to newer and faster workstations and front-end computers, we have found performance of the system declining and have implemented an upgraded network. There have been dramatic advances in networking hardware in the last several years. The upgraded APS controls network replaces the original FDDI backbone and shared Ethernet hubs with redundant gigabit uplinks and fully switched 10/100 Ethernet switches with backplane fabrics in excess of 20 Gbits/s (Gbps). The central collapsed backbone FDDI concentrator has been replaced with a Gigabit Ethernet switch with greater than 30 Gbps backplane fabric. Full redundancy of the system has been maintained. This paper will discuss this upgrade and include performance data and performance comparisons with the original network.

  18. Electrogeneration of hydroperoxide ion using an alkaline fuel cell

    SciTech Connect

    Alcaide, F.; Brillas, E.; Cabot, P.L.; Casado, J.

    1998-10-01

    Hydrogen peroxide is a pollution-control chemical commonly used as a bleaching agent, as a disinfectant, and as a nonselective oxidant for water purification and in different industrial processes. This paper describes a novel electrochemical method for the generation of HO{sub 2}{sup {minus}} using an alkaline fuel cell (AFC). The system is formed by an undivided cell containing a H{sub 2}-diffusion anode, an O{sub 2}-diffusion cathode, and a KOH solution as electrolyte. It can work in batch or in continuous mode, cogenerating electricity and HO{sub 2}{sup {minus}}, which is formed from the two-electron reduction of O{sub 2} at the cathode. The evolution of cell voltage, current density, HO{sub 2}{sup {minus}} production, and current efficiency with time have been determined when the electrolyte remains quiescent, recirculates through the cell, or is continuously injected to it. This last device yields the best operative parameters, allowing current densities of 130 mA/cm{sup 2} and current efficiencies close to 100% using 1 mol/dm{sup 3} KOH at 20 C. The effect of HO{sub 2}{sup {minus}} upon the anodic and cathodic reactions has been studied by linear sweep voltammetry. Adsorption of this species on the cathode can explain the loss of performance of the AFC with working time using a quiescent electrolyte or under recirculation conditions. The O{sub 2}-diffusion cathode and the AFC showed good reversibility when the cell contained a fresh KOH solution with HO{sub 2}{sup {minus}}.

  19. EPA’s AP-42 development methodology: Converting or rerating current AP-42 datasets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In August 2013, the U.S. Environmental Protection Agency’s (EPA) published their new methodology for updating the Compilation of Air Pollution Emission Factors (AP-42). The “Recommended Procedures for Development of Emissions Factors and Use of the WebFIRE Database” instructs that the ratings of the...

  20. Evaluating EPA’s AP-42 development methodology to convert or rerate current AP-42 datasets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In August 2013, the U.S. Environmental Protection Agency’s (EPA) published their new methodology for updating the Compilation of Air Pollution Emission Factors (AP-42). The “Recommended Procedures for Development of Emissions Factors and Use of the WebFIRE Database” instructs that the ratings of the...

  1. The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

    PubMed Central

    Schwalfenberg, Gerry K.

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine. PMID:22013455

  2. MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

    EPA Science Inventory

    The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

  3. Negative Electrode For An Alkaline Cell

    DOEpatents

    Coco, Isabelle; Cocciantelli, Jean-Michel; Villenave, Jean-Jacques

    1998-07-14

    The present invention concerns a negative electrode for an alkaline cell, comprising a current collector supporting a paste containing an electrochemically active material and a binder, characterized in that said binder is a polymer containing hydrophilic and hydrophobic groups, said polymer being selected from an acrylic homopolymer, copolymer and terpolymer, an unsaturated organic acid copolymer and an unsaturated acid anhydride copolymer.

  4. Kinetics of the alkaline hydrolysis of nitrocellulose.

    PubMed

    Christodoulatos, C; Su, T L; Koutsospyros, A

    2001-01-01

    Cellulose nitrate (nitrocellulose) is an explosive solid substance used in large quantities in various formulations of rocket and gun propellants. Safe destruction of nitrocellulose can be achieved by alkaline hydrolysis, which converts it to biodegradable products that can then be treated by conventional biological processes. The kinetics of the alkaline hydrolysis of munitions-grade nitrocellulose in sodium hydroxide solutions were investigated in completely mixed batch reactors. Experiments were conducted using solutions of alkaline strength ranging from 0.1 to 15% by mass and temperatures in the range of 30 to 90 degrees C. Regression analysis of the kinetic data revealed that alkaline hydrolysis of nitrocellulose is of the order 1.0 and 1.5 with respect to nitrocellulose and hydroxide concentration, respectively. The activation energy of the hydrolysis reaction was found to be 100.9 kJ/mol with a preexponential Arrhenius constant of 4.73 x 10(13). Nitrite and nitrate, in a 3:1 ratio, were the primary nitrogen species present in the posthydrolysis solution. The kinetic information is pertinent to the development and optimization of nitrocellulose chemical-biological treatment systems. PMID:11563378

  5. Use Alkalinity Monitoring to Optimize Bioreactor Performance.

    PubMed

    Jones, Christopher S; Kult, Keegan J

    2016-05-01

    In recent years, the agricultural community has reduced flow of nitrogen from farmed landscapes to stream networks through the use of woodchip denitrification bioreactors. Although deployment of this practice is becoming more common to treat high-nitrate water from agricultural drainage pipes, information about bioreactor management strategies is sparse. This study focuses on the use of water monitoring, and especially the use of alkalinity monitoring, in five Iowa woodchip bioreactors to provide insights into and to help manage bioreactor chemistry in ways that will produce desirable outcomes. Results reported here for the five bioreactors show average annual nitrate load reductions between 50 and 80%, which is acceptable according to established practice standards. Alkalinity data, however, imply that nitrous oxide formation may have regularly occurred in at least three of the bioreactors that are considered to be closed systems. Nitrous oxide measurements of influent and effluent water provide evidence that alkalinity may be an important indicator of bioreactor performance. Bioreactor chemistry can be managed by manipulation of water throughput in ways that produce adequate nitrate removal while preventing undesirable side effects. We conclude that (i) water should be retained for longer periods of time in bioreactors where nitrous oxide formation is indicated, (ii) measuring only nitrate and sulfate concentrations is insufficient for proper bioreactor operation, and (iii) alkalinity monitoring should be implemented into protocols for bioreactor management. PMID:27136151

  6. ISSUES WITH ALKALINE TREATMENT OF SLUDGE

    EPA Science Inventory

    This presentation begins with a discussion of the use of lime and other alkaline materials from the very earliest times to the present for killing bacteria, viruses and parasites and for controlling odors in wastewaters and sludge. It answers the question "How did EPA arrive at i...

  7. Alkaline electrochemical cells and method of making

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    Equilibrated cellulose ether membranes of increased electrolytic conductivity for use as separators in concentrated alkaline electrochemical cells are investigated. The method of making such membranes by equilibration to the degree desired in an aqueous alkali solution mantained at a temperature below about 10 C is described.

  8. Hydrogen peroxide mediates higher order chromatin degradation.

    PubMed

    Bai, H; Konat, G W

    2003-01-01

    Although a large body of evidence supports a causative link between oxidative stress and neurodegeneration, the mechanisms are still elusive. We have recently demonstrated that hydrogen peroxide (H(2)O(2)), the major mediator of oxidative stress triggers higher order chromatin degradation (HOCD), i.e. excision of chromatin loops at the matrix attachment regions (MARs). The present study was designed to determine the specificity of H(2)O(2) in respect to HOCD induction. Rat glioma C6 cells were exposed to H(2)O(2) and other oxidants, and the fragmentation of genomic DNA was assessed by field inversion gel electrophoresis (FIGE). S1 digestion before FIGE was used to detect single strand fragmentation. The exposure of C6 cells to H(2)O(2) induced a rapid and extensive HOCD. Thus, within 30 min, total chromatin was single strandedly digested into 50 kb fragments. Evident HOCD was elicited by H(2)O(2) at concentrations as low as 5 micro M. HOCD was mostly reversible during 4-8h following the removal of H(2)O(2) from the medium indicating an efficient relegation of the chromatin fragments. No HOCD was induced by H(2)O(2) in isolated nuclei indicating that HOCD-endonuclease is activated indirectly by cytoplasmic signal pathways triggered by H(2)O(2). The exposure of cells to a synthetic peroxide, i.e. tert-butyrylhydroperoxide (tBH) also induced HOCD, but to a lesser extent than H(2)O(2). Contrary to the peroxides, the exposure of cells to equitoxic concentration of hypochlorite and spermine NONOate, a nitric oxide generator, failed to induce rapid HOCD. These results indicate that rapid HOCD is not a result of oxidative stress per se, but is rather triggered by signaling cascades initiated specifically by H(2)O(2). Furthermore, the rapid and extensive HOCD was observed in several rat and human cell lines challenged with H(2)O(2), indicating that the process is not restricted to glial cells, but rather represents a general response of cells to H(2)O(2). PMID:12421592

  9. A single β adaptin contributes to AP1 and AP2 complexes and clathrin function in Dictyostelium.

    PubMed

    Sosa, R Thomas; Weber, Michelle M; Wen, Yujia; O'Halloran, Theresa J

    2012-02-01

    The assembly of clathrin-coated vesicles is important for numerous cellular processes, including nutrient uptake and membrane organization. Important contributors to clathrin assembly are four tetrameric assembly proteins, also called adaptor proteins (APs), each of which contains a β subunit. We identified a single β subunit, named β1/2, that contributes to both the AP1 and AP2 complexes of Dictyostelium. Disruption of the gene encoding β1/2 resulted in severe defects in growth, cytokinesis and development. Additionally, cells lacking β1/2 displayed profound osmoregulatory defects including the absence of contractile vacuoles and mislocalization of contractile vacuole markers. The phenotypes of β1/2 null cells were most similar to previously described phenotypes of clathrin and AP1 mutants, supporting a particularly important contribution of AP1 to clathrin pathways in Dictyostelium cells. The absence of β1/2 in cells led to significant reductions in the protein amounts of the medium-sized subunits of the AP1 and AP2 complexes, establishing a role for the β subunit in the stability of the medium subunits. Dictyostelium β1/2 could resemble a common ancestor of the more specialized β1 and β2 subunits of the vertebrate AP complexes. Our results support the essential contribution of a single β subunit to the stability and function of AP1 and AP2 in a simple eukaryote. PMID:22050483

  10. Radiation characteristics of scintillator coupled CMOS APS for radiography conditions

    NASA Astrophysics Data System (ADS)

    Kim, Kwang Hyun; Kim, Soongpyung; Kang, Dong-Won; Kim, Dong-Kie

    2006-11-01

    Under industrial radiography conditions, we analyzed short-term radiation characteristics of scintillator coupled CMOS APS (hereinafter SC CMOS APS). By means of experimentation, the contribution of the transmitted X-ray through the scintillator to the properties of the CMOS APS and the afterimage, generated in the acquired image even at low dose condition, were investigated. To see the transmitted X-ray effects on the CMOS APS, Fein focus™ X-ray machine, two scintillators of Lanex™ Fine and Regular, and two CMOS APS array of RadEye™ were used under the conditions of 50 kV p/1 mAs and 100 kV p/1 mAs. By measuring the transmitted X-ray on signal and Noise Power Spectrum, we analytically examined the generation mechanism of the afterimage, based on dark signal or dark current increase in the sensor, and explained the afterimage in the SC CMOS APS.

  11. Improved synthesis of ceramic superconductors with alkaline earth peroxides - Synthesis and processing of Ba2YCu3O(7-x)

    NASA Technical Reports Server (NTRS)

    Hepp, A. F.; Gaier, J. R.; Philipp, W. H.; Warner, J. D.; Aron, P. R.; Pouch, J. J.

    1988-01-01

    Synthesis processes for the preparation of ceramic conductors Ba2YCu3O(7-x) from BaO2 or BaCO3 in flowing O2 or N2 are described, and the characteristics of the materials produced in these processes are compared. Results of EDAX, XRD, SEM, and dc resistivity analyses demonstrated that superconducting materials made from BaO2 were more homogeneous, denser, and more metallic than materials produced from BaCO3, because of the higher reactivity of BaO2. Potential applications of this processes are discussed.

  12. Hydrogen peroxide sensing, signaling and regulation of transcription factors

    PubMed Central

    Marinho, H. Susana; Real, Carla; Cyrne, Luísa; Soares, Helena; Antunes, Fernando

    2014-01-01

    The regulatory mechanisms by which hydrogen peroxide (H2O2) modulates the activity of transcription factors in bacteria (OxyR and PerR), lower eukaryotes (Yap1, Maf1, Hsf1 and Msn2/4) and mammalian cells (AP-1, NRF2, CREB, HSF1, HIF-1, TP53, NF-κB, NOTCH, SP1 and SCREB-1) are reviewed. The complexity of regulatory networks increases throughout the phylogenetic tree, reaching a high level of complexity in mammalians. Multiple H2O2 sensors and pathways are triggered converging in the regulation of transcription factors at several levels: (1) synthesis of the transcription factor by upregulating transcription or increasing both mRNA stability and translation; (ii) stability of the transcription factor by decreasing its association with the ubiquitin E3 ligase complex or by inhibiting this complex; (iii) cytoplasm–nuclear traffic by exposing/masking nuclear localization signals, or by releasing the transcription factor from partners or from membrane anchors; and (iv) DNA binding and nuclear transactivation by modulating transcription factor affinity towards DNA, co-activators or repressors, and by targeting specific regions of chromatin to activate individual genes. We also discuss how H2O2 biological specificity results from diverse thiol protein sensors, with different reactivity of their sulfhydryl groups towards H2O2, being activated by different concentrations and times of exposure to H2O2. The specific regulation of local H2O2 concentrations is also crucial and results from H2O2 localized production and removal controlled by signals. Finally, we formulate equations to extract from typical experiments quantitative data concerning H2O2 reactivity with sensor molecules. Rate constants of 140 M−1 s−1 and ≥1.3 × 103 M−1 s−1 were estimated, respectively, for the reaction of H2O2 with KEAP1 and with an unknown target that mediates NRF2 protein synthesis. In conclusion, the multitude of H2O2 targets and mechanisms provides an opportunity for highly

  13. A Three-Step Synthesis of Benzoyl Peroxide

    ERIC Educational Resources Information Center

    Her, Brenda; Jones, Alexandra; Wollack, James W.

    2014-01-01

    Benzoyl peroxide is used as a bleaching agent for flour and whey processing, a polymerization initiator in the synthesis of plastics, and the active component of acne medication. Because of its simplicity and wide application, benzoyl peroxide is a target molecule of interest. It can be affordably synthesized in three steps from bromobenzene using…

  14. Differentiation among peroxide explosives with an optoelectronic nose.

    PubMed

    Li, Zheng; Bassett, Will P; Askim, Jon R; Suslick, Kenneth S

    2015-10-25

    Forensic identification of batches of homemade explosives (HME) poses a difficult analytical challenge. Differentiation among peroxide explosives is reported herein using a colorimetric sensor array and handheld scanner with a field-appropriate sampling protocol. Clear discrimination was demonstrated among twelve peroxide samples prepared from different reagents, with a classification accuracy >98%. PMID:26340082

  15. Demonstration of the Catalytic Decomposition of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Conklin, Alfred R. Jr.; Kessinger, Angela

    1996-01-01

    Describes a demonstration known as Elephant's Toothpaste in which the decomposition of hydrogen peroxide is catalyzed by iodide. Oxygen is released and soap bubbles are produced. The foam produced is measured, and results show a good relationship between the amount of foam and the concentration of the hydrogen peroxide. (DDR)

  16. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am - the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting ...

  17. A method for making an alkaline battery electrode plate

    NASA Technical Reports Server (NTRS)

    Chida, K.; Ezaki, T.

    1983-01-01

    A method is described for making an alkaline battery electrode plate where the desired active substances are filled into a nickel foam substrate. In this substrate an electrolytic oxidation reduction occurs in an alkaline solution containing lithium hydroxide.

  18. Control units for APS power supplies

    SciTech Connect

    Despe, O.D.; Saunders, C.; McGhee, D.G.

    1993-07-01

    The Advanced Photon Source (APS) accelerator facility is made up of five major subsystems in addition to the linac: the positron accumulator ring (PAR), low energy transport (LET), booster synchrotron (SYNCH), high energy transport (HET), the storage ring (SR). Each subsystem has multiple magnet power supply combinations, some requiring multiple of operation. These magnet and power supply combinations computer controlled and monitored. The power supply control unit (PSCU) is the first layer of hardware and software above the power supply itself and is described in this paper. The description includes the basic philosophy for each of operation and how it influences the topology and of implementing control. The design of the analog reference blocks (ARBs) influenced the design of other custom functions well as the feedback controls for vibration and other dynamic corrections. The command set supported by the PSCU is discussed.

  19. Energy Efficient Catalytic Activation of Hydrogen peroxide for Green Chemical Processes: Final Report

    SciTech Connect

    Collins, Terrence J.; Horwitz, Colin

    2004-11-12

    A new, highly energy efficient approach for using catalytic oxidation chemistry in multiple fields of technology has been pursued. The new catalysts, called TAML® activators, catalyze the reactions of hydrogen peroxide and other oxidants for the exceptionally rapid decontamination of noninfectious simulants (B. atrophaeus) of anthrax spores, for the energy efficient decontamination of thiophosphate pesticides, for the facile, low temperature removal of color and organochlorines from pulp and paper mill effluent, for the bleaching of dyes from textile mill effluents, and for the removal of recalcitrant dibenzothiophene compounds from diesel and gasoline fuels. Highlights include the following: 1) A 7-log kill of Bacillus atrophaeus spores has been achieved unambiguously in water under ambient conditions within 15 minutes. 2) The rapid total degradation under ambient conditions of four thiophosphate pesticides and phosphonate degradation intermediates has been achieved on treatment with TAML/peroxide, opening up potential applications of the decontamination system for phosphonate structured chemical warfare agents, for inexpensive, easy to perform degradation of stored and aged pesticide stocks (especially in Africa and Asia), for remediation of polluted sites and water bodies, and for the destruction of chemical warfare agent stockpiles. 3) A mill trial conducted in a Pennsylvanian bleached kraft pulp mill has established that TAML catalyst injected into an alkaline peroxide bleach tower can significantly lower color from the effluent stream promising a new, more cost effective, energy-saving approach for color remediation adding further evidence of the value and diverse engineering capacity of the approach to other field trials conducted on effluent streams as they exit the bleach plant. 4) Dibenzothiophenes (DBTs), including 4,6-dimethyldibenzothiophene, the most recalcitrant sulfur compounds in diesel and gasoline, can be completely removed from model gasoline

  20. Hydrogen Peroxide Storage in Small Sealed Tanks

    SciTech Connect

    Whitehead, J.

    1999-10-20

    Unstabilized hydrogen peroxide of 85% concentration has been prepared in laboratory quantities for testing material compatibility and long term storage on a small scale. Vessels made of candidate tank and liner materials ranged in volume from 1 cc to 2540 cc. Numerous metals and plastics were tried at the smallest scales, while promising ones were used to fabricate larger vessels and liners. An aluminum alloy (6061-T6) performed poorly, including increasing homogeneous decay due to alloying elements entering solution. The decay rate in this high strength aluminum was greatly reduced by anodizing. Better results were obtained with polymers, particularly polyvinylidene fluoride. Data reported herein include ullage pressures as a function of time with changing decay rates, and contamination analysis results.

  1. Hydrogen peroxide biosensor based on titanium oxide

    NASA Astrophysics Data System (ADS)

    Halim, Nur Hamidah Abdul; Heng, Lee Yook; Hashim, Uda

    2015-09-01

    In this work, a biosensor utilizing modified titania, TiO2 particles using aminopropyl-triethoxy-silane, (APTS) for developing hydrogen peroxide biosensor is presented. The surface of Ti-APTS particles is used as a support for hemoglobin immobilization via covalent bonding. The performance of the biosensor is determined by differential pulse voltammetry. The linear response was observed at the reduction current of redox mediator probe [FeCN6]3-/4- at potential between 0.22 V to 0.24 V. The preliminary result for electrochemistry study on this modified electrode is reported. The preliminary linear range is obtained from 1×10-2 M to 1×10-8 M.

  2. Hydrogen Peroxide (HP) Potential for Space Applications

    NASA Astrophysics Data System (ADS)

    Grafwallner, F.

    2004-10-01

    Low toxicity or "green" propellants are now under study by organizations around the world. Especially ultra high concentrated hydrogen peroxide (HP) may be a significant step toward less toxic, storable und safer operation of upper stages and spacecrafts. HP can be used as a monopropellant, when catalytically decomposed or as a bipropellant constituting the propellant combination`s oxidizer. Serving as a monopropellant, catalytic decomposition will result in exhaust of superheated steam and oxygen which can be used to drive gas turbines and feed life support systems or provide thrust as a monopropellant, provide the oxidizer, or function as an igniter for bipropellant engines. HP can be used in fuel cells to produce electrical power, heat and water.

  3. Aromatic hydroxylations in peroxidations by haemoglobin systems.

    PubMed

    Esclade, L; Guillochon, D; Thomas, D

    1986-07-01

    The catalytic activity of haemoglobin on aromatic substrates was studied in three systems: NADH-methylene blue-haemoglobin, ascorbic acid-haemoglobin, and red blood cells. Aniline and phenol but not acetanilide or p-toluidine are hydroxylated by haemoglobin. Dealkylations are not observed. Hydroxylations are postulated to be intermediate reactions in peroxidations catalysed by haemoglobin. The lifetime of the products depends on the presence of electron donors, such as NADH or ascorbic acid, in the medium. In the red blood cells where endogenous electron donors are recycled, levels of the products are higher and their lifetime is longer. This could have implications on drug metabolism by haemoglobin, as haemoglobin is present in large quantities in the organism. PMID:3751116

  4. Lipid peroxidation in ethanol poisoning: a critical reconsideration.

    PubMed

    Dianzani, M U

    1985-01-01

    Evidence for the existence of increased lipid peroxidation in the liver after ethanol administration to rats is discussed. A criticism of the methods used to measure lipid peroxidation is also given. Most authors who are in favour of the presence of lipid peroxidation after ethanol have used the detection of thiobarbituric acid (TBA)-reacting substances as a measure of lipid peroxidation. This test is not entirely satisfactory, because: (1) it is not specific; (2) it mostly measures malonaldehyde, a substance of low toxicity, following a 1-2 hr incubation time; (3) several aldehydes produced during lipid peroxidation do not react with TBA. However, it is now clear that the aldehydes produced during lipid peroxidation are actively metabolized by homogenates, so differences in catabolism may influence the result of a TBA test. Measurement of the diene conjugation band, the other test usually used to detect lipid peroxidation, produces information only on the presence of dienes at a given moment, but does not give any information on the production or decomposition rates of such dienes. Thus differences in production or decomposition kinetics may mask the results. Notwithstanding these criticisms, most of the evidence at present is in favour of some involvement of lipid peroxidation in ethanol intoxication. One hypothesis is that of the direct impact of ethanol-derived free radicals. Another is that ethanol provokes the formation of oxygen free radical species, which can start lipid peroxidation either directly, or by exhausting anti-oxidant substances in the cell so as to change the balance in favour of increased peroxidation. Finally, a third hypothesis is that acetaldehyde, the main product of ethanol oxidation, is able to stimulate lipid peroxidation, possibly through the formation of free radicals, or depletion of levels of antioxidant substances. Experiments consisting of measuring total glutathione (GSH and GSSG) during lipid peroxidation stimulated by ethanol

  5. Stabilization of Different Types of Transition States in a Single Enzyme Active Site: QM/MM Analysis of Enzymes in the Alkaline Phosphatase Superfamily

    PubMed Central

    Hou, Guanhua; Cui, Qiang

    2013-01-01

    The first step for the hydrolysis of a phosphate monoester (pNPP2−) in enzymes of the alkaline phosphatase (AP) superfamily, R166S AP and wild type NPP, is studied using QM/MM simulations based on an approximate density functional theory (SCC-DFTBPR) and a recently introduced QM/MM interaction Hamiltonian. The calculations suggest that similar loose transition states are involved in both enzymes, despite the fact that phosphate monoesters are the cognate substrates for AP but promiscuous substrates for NPP. The computed loose transition states are clearly different from the more synchronous ones previously calculated for diester reactions in the same AP enzymes. Therefore, our results explicitly support the proposal that AP enzymes are able to recognize and stabilize different types of transition states in a single active site. Analysis of the structural features of computed transition states indicates that the plastic nature of the bi-metallic site plays a minor role in accommodating multiple types of transition states, and that the high degree of solvent accessibility of the AP active site also contributes to its ability to stabilize diverse transition state structures without the need of causing large structural distortions of the bimetallic motif. The binding mode of the leaving group in the transition state highlights that vanadate may not always be an ideal transition state analog for loose phosphoryl transfer transition states. PMID:23786365

  6. Bactericidal effect of hydrogen peroxide on spacecraft isolates

    NASA Technical Reports Server (NTRS)

    Wardle, M. D.; Renninger, G. M.

    1975-01-01

    Results are presented for an experimental study designed to assess the effect of hydrogen peroxide on both sporeforming and nonsporeforming spacecraft isolates as an initial step in determining its suitability for microbiological decontamination of certain United States spacecraft. Survivor data were obtained for eight bacterial isolates (six sporeformers and two nonsporeformers) recovered before launch Mariner 9 and exposed to concentrations of 3, 10, and 15% hydrogen peroxide. The effects of various concentrations of hydrogen peroxide on the spores are presented in tabular form, along with the percentage of survival of nonsporeformers exposed to hydrogen peroxide. No viable vegetative cells were recovered after a 10-min exposure time to any of the three concentration of hydrogen peroxide.

  7. Low Earth orbit assessment of proton anisotropy using AP8 and AP9 trapped proton models

    NASA Astrophysics Data System (ADS)

    Badavi, Francis F.; Walker, Steven A.; Santos Koos, Lindsey M.

    2015-04-01

    The completion of the International Space Station (ISS) in 2011 has provided the space research community with an ideal evaluation and testing facility for future long duration human activities in space. Ionized and secondary neutral particles radiation measurements inside ISS form the ideal tool for validation of radiation environmental models, nuclear reaction cross sections and transport codes. Studies using thermo-luminescent detectors (TLD), tissue equivalent proportional counter (TPEC), and computer aided design (CAD) models of early ISS configurations confirmed that, as input, computational dosimetry at low Earth orbit (LEO) requires an environmental model with directional (anisotropic) capability to properly describe the exposure of trapped protons within ISS. At LEO, ISS encounters exposure from trapped electrons, protons and geomagnetically attenuated galactic cosmic rays (GCR). For short duration studies at LEO, one can ignore trapped electrons and ever present GCR exposure contributions during quiet times. However, within the trapped proton field, a challenge arises from properly estimating the amount of proton exposure acquired. There exist a number of models to define the intensity of trapped particles. Among the established trapped models are the historic AE8/AP8, dating back to the 1980s and the recently released AE9/AP9/SPM. Since at LEO electrons have minimal exposure contribution to ISS, this work ignores the AE8 and AE9 components of the models and couples a measurement derived anisotropic trapped proton formalism to omnidirectional output from the AP8 and AP9 models, allowing the assessment of the differences between the two proton models. The assessment is done at a target point within the ISS-11A configuration (circa 2003) crew quarter (CQ) of Russian Zvezda service module (SM), during its ascending and descending nodes passes through the south Atlantic anomaly (SAA). The anisotropic formalism incorporates the contributions of proton narrow

  8. Low Earth orbit assessment of proton anisotropy using AP8 and AP9 trapped proton models.

    PubMed

    Badavi, Francis F; Walker, Steven A; Santos Koos, Lindsey M

    2015-04-01

    The completion of the International Space Station (ISS) in 2011 has provided the space research community with an ideal evaluation and testing facility for future long duration human activities in space. Ionized and secondary neutral particles radiation measurements inside ISS form the ideal tool for validation of radiation environmental models, nuclear reaction cross sections and transport codes. Studies using thermo-luminescent detectors (TLD), tissue equivalent proportional counter (TPEC), and computer aided design (CAD) models of early ISS configurations confirmed that, as input, computational dosimetry at low Earth orbit (LEO) requires an environmental model with directional (anisotropic) capability to properly describe the exposure of trapped protons within ISS. At LEO, ISS encounters exposure from trapped electrons, protons and geomagnetically attenuated galactic cosmic rays (GCR). For short duration studies at LEO, one can ignore trapped electrons and ever present GCR exposure contributions during quiet times. However, within the trapped proton field, a challenge arises from properly estimating the amount of proton exposure acquired. There exist a number of models to define the intensity of trapped particles. Among the established trapped models are the historic AE8/AP8, dating back to the 1980s and the recently released AE9/AP9/SPM. Since at LEO electrons have minimal exposure contribution to ISS, this work ignores the AE8 and AE9 components of the models and couples a measurement derived anisotropic trapped proton formalism to omnidirectional output from the AP8 and AP9 models, allowing the assessment of the differences between the two proton models. The assessment is done at a target point within the ISS-11A configuration (circa 2003) crew quarter (CQ) of Russian Zvezda service module (SM), during its ascending and descending nodes passes through the south Atlantic anomaly (SAA). The anisotropic formalism incorporates the contributions of proton narrow

  9. Coupling technique of self-ordered ring and phosphorimetry for the determination of alkaline phosphatase and diseases prediction

    NASA Astrophysics Data System (ADS)

    Zhang, Li Hong; Zheng, Zhi Yong; Jiang, Shu-Lian; Cui, Ma-Lin; Jiao, Li; Lin, Xuan; Cai, Wen-Lian; Lin, Shao-Qin; liu, Jia-Ming

    2012-11-01

    Rhodamine S could emit strong and stable room temperature phosphorescence (RTP) on polyamide membrane (PAM) in the presence of heavy atom perturber Pb2+. When Rhodamine S-piperidine solution was dropped on PAM, the red (Rhod.S)n-P-SOR (Rhod.S, (Rhod.S)n, P and SOR refer to alizarin red S, multiple Rhod.S molecules, piperidine and self-ordered ring, respectively) formed on PAM, leading to the enhancement of room temperature phosphorimetry (RTP) intensity (Ip, 117.2) of (Rhod.S)n-P-SOR system, which was 2.4 times higher than that without SOR (Ip, 48.1). Wheat germ agglutinin (WGA) was labelled with (Rhod.S)n-P-SOR by the -NH- of Rhod.S reacting with the -COOH of WGA to form WGA-(Rhod.S)n-P-SOR. The formation of WGA-AP-WGA-(Rhod.S)n-P-SOR in the affinity adsorption (AA) reaction carried out between the -COOH of WGA in WGA-(Rhod.S)n-P-SOR and the -NH2 of alkaline phosphatase (AP) caused the RTP intensity (ΔIp) of the WGA-AP-WGA-(Rhod.S)n-P-SOR system 7.8 times larger than that without (Rhod.S)n-P-SOR. Therefore, the coupling technique of SOR and solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace AP has been established. This method possessed good selectivity, high sensitivity (Detection limit (L.D) was 3.4 × 10-16 g mL-1) and accuracy, and it has been applied to the determination of trace AP in human serum and the forecast of human diseases, and the results agreed well with those obtained by enzyme-linked immunoassay (ELISA). Besides, the mechanism of the coupling technique for the determination of AP was discussed.

  10. Studies of a granular aluminum anode in an alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Popovich, Neil A.; Govind, Rakesh

    A granular aluminum anode was investigated for use in an alkaline aluminum/hydrogen peroxide fuel cell. The fuel cell utilizes granules of aluminum (8-12 mm in diameter) as an anode, potassium hydroxide (KOH) as an anolyte and hydrogen peroxide as a catholyte. Granular anodes have a significantly higher surface area than planar surfaces, thereby resulting in higher utilization of the anode material. Polarization experiments were performed as well as closed circuit power production experiments. KOH concentrations were varied in the experiments. Polarization experiments achieved a current density of 10.02 mA/cm 2 using 2 M KOH and granular aluminum with a surface area of 205.6 cm 2. Power production experiments sustained a current density of 0.05 mA/cm 2 using 1.5 M KOH and granular aluminum with a surface area of 59.8 cm 2. Results indicate that granular metal anodes have potential for use in high energy density fuel cells.

  11. PEROXIDE DESTRUCTION TESTING FOR THE 200 AREA EFFLUENT TREATMENT FACILITY

    SciTech Connect

    HALGREN DL

    2010-03-12

    The hydrogen peroxide decomposer columns at the 200 Area Effluent Treatment Facility (ETF) have been taken out of service due to ongoing problems with particulate fines and poor destruction performance from the granular activated carbon (GAC) used in the columns. An alternative search was initiated and led to bench scale testing and then pilot scale testing. Based on the bench scale testing three manganese dioxide based catalysts were evaluated in the peroxide destruction pilot column installed at the 300 Area Treated Effluent Disposal Facility. The ten inch diameter, nine foot tall, clear polyvinyl chloride (PVC) column allowed for the same six foot catalyst bed depth as is in the existing ETF system. The flow rate to the column was controlled to evaluate the performance at the same superficial velocity (gpm/ft{sup 2}) as the full scale design flow and normal process flow. Each catalyst was evaluated on peroxide destruction performance and particulate fines capacity and carryover. Peroxide destruction was measured by hydrogen peroxide concentration analysis of samples taken before and after the column. The presence of fines in the column headspace and the discharge from carryover was generally assessed by visual observation. All three catalysts met the peroxide destruction criteria by achieving hydrogen peroxide discharge concentrations of less than 0.5 mg/L at the design flow with inlet peroxide concentrations greater than 100 mg/L. The Sud-Chemie T-2525 catalyst was markedly better in the minimization of fines and particle carryover. It is anticipated the T-2525 can be installed as a direct replacement for the GAC in the peroxide decomposer columns. Based on the results of the peroxide method development work the recommendation is to purchase the T-2525 catalyst and initially load one of the ETF decomposer columns for full scale testing.

  12. Project W-211, initial tank retrieval systems, description of operations for 241-AP-102 and 241-AP-104

    SciTech Connect

    RIECK, C.A.

    1999-02-25

    The primary purpose of the Initial Tank Retrieval Systems (ITRS) is to provide systems for retrieval of radioactive wastes stored in underground double-shell tanks (DSTS) for transfer to alternate storage, evaporation, pretreatment or treatment, while concurrently reducing risks associated with safety watch list and other DSTs. This Description of Operations (DOO) defines the control philosophy for the waste retrieval system for tanks 241-AP-102 (AP-102) and 241-AP-104 (AP-104). This DOO will provide a basis for the detailed design of the Retrieval Control System (RCS) for AP-102 and AP-104 and establishes test criteria for the RCS. The test criteria will be used during qualification testing and acceptance testing to verify operability.

  13. At-home vital bleaching: a comparison of hydrogen peroxide and carbamide peroxide treatments.

    PubMed

    Berga-Caballero, Amparo; Forner-Navarro, Leopoldo; Amengual-Lorenzo, José

    2006-01-01

    Tray bleaching of vital teeth performed at home by the patient under the dentist s supervision, whether alone or in combination with any of the in-office techniques, provides an interesting alternative to other methods employed in this type of dental treatment. This bleaching procedure applies low-concentration peroxides to the enamel by means of a custom-made mouth tray specifically designed for this purpose. The aim of this study is to examine and compare two commercially-available bleaching products, at equivalent concentrations, for use in this technique: VivaStyle (Vivadent) and FKD (Kin); the former is a 10% carbamide peroxide and the latter a 3.5% hydrogen peroxide formulation. It examines the parameters that must be monitored during the application of this type of procedure and presents 6 cases (3 treated with one of the above-mentioned products and the other 3 with the other), establishing the bleaching power of the products and the appearance and intensity of post-operatory hypersensitivity. The results obtained show that both products are effective for the purpose for which they were designed. In general, dental hypersensitivity was minimal. PMID:16388304

  14. FINAL REPORT. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Investigation of behavior of actinides in alkaline media containing Al(III) showed that no aluminate complexes of actinides in oxidation states (III-VII) were formed in alkaline solutions. At alkaline precipitation (pH 10-14) of actinides in presence of Al(III) formation of alumi...

  15. Modeling catalytic promiscuity in the alkaline phosphatase superfamily

    PubMed Central

    Duarte, Fernanda; Amrein, Beat Anton

    2013-01-01

    In recent years, it has become increasingly clear that promiscuity plays a key role in the evolution of new enzyme function. This finding has helped to elucidate fundamental aspects of molecular evolution. While there has been extensive experimental work on enzyme promiscuity, computational modeling of the chemical details of such promiscuity has traditionally fallen behind the advances in experimental studies, not least due to the nearly prohibitive computational cost involved in examining multiple substrates with multiple potential mechanisms and binding modes in atomic detail with a reasonable degree of accuracy. However, recent advances in both computational methodologies and power have allowed us to reach a stage in the field where we can start to overcome this problem, and molecular simulations can now provide accurate and efficient descriptions of complex biological systems with substantially less computational cost. This has led to significant advances in our understanding of enzyme function and evolution in a broader sense. Here, we will discuss currently available computational approaches that can allow us to probe the underlying molecular basis for enzyme specificity and selectivity, discussing the inherent strengths and weaknesses of each approach. As a case study, we will discuss recent computational work on different members of the alkaline phosphatase superfamily (AP) using a range of different approaches, showing the complementary insights they have provided. We have selected this particular superfamily, as it poses a number of significant challenges for theory, ranging from the complexity of the actual reaction mechanisms involved to the reliable modeling of the catalytic metal centers, as well as the very large system sizes. We will demonstrate that, through current advances in methodologies, computational tools can provide significant insight into the molecular basis for catalytic promiscuity, and, therefore, in turn, the mechanisms of protein

  16. An in vitro study of alkaline phosphatase sensitivity to mixture of aflatoxin B1 and fumonisin B1 in the hepatopancreas of coastal lagoon wild and farmed shrimp Litopenaeus vannamei.

    PubMed

    Pérez-Acosta, Jesús A; Burgos-Hernandez, Armando; Velázquez-Contreras, Carlos A; Márquez-Ríos, Enrique; Torres-Arreola, Wilfrido; Arvizu-Flores, Aldo A; Ezquerra-Brauer, J Marina

    2016-08-01

    This study aimed to establish the combined effect of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) on wild Litopenaeus vannamei hepatopancreas alkaline phosphatase (AP) activity compared with that of farmed shrimp. AP activity in hepatopancreas extract was confirmed by several specific inhibitor assays. AP activity of wild shrimp was higher than that of farmed shrimp (p < 0.05). However, AP activity from both wild and farmed shrimp was inhibited when incubated with AFB1 and FB1. The greatest inhibition occurred when AP was incubated with a mixture of AFB1 and FB1. The IC50 for AFB1 on AP activity of wild and farmed shrimp hepatopancreases was 0.790 and 0.398 μg/mL, respectively. The IC50 of FB1 was 0.87 μg/mL for wild shrimp and 0.69 μg/mL for farmed shrimp. These results suggest that, at the mycotoxins concentrations used in the study, AP from farmed L. vannamei was sensitive to the presence of both mycotoxins; however, AP is more sensitive to the combination of AFB1 + FB1 suggesting a possible synergistic or potentiating inhibitory effect. PMID:27040818

  17. A protocol to generate phthaloyl peroxide in flow for the hydroxylation of arenes.

    PubMed

    Eliasen, Anders M; Thedford, Randal P; Claussen, Karin R; Yuan, Changxia; Siegel, Dionicio

    2014-07-18

    A flow protocol for the generation of phthaloyl peroxide has been developed. This process directly yields phthaloyl peroxide in high purity (>95%) and can be used to bypass the need to isolate and recrystallize phthaloyl peroxide, improving upon earlier batch procedures. The flow protocol for the formation of phthaloyl peroxide can be combined with arene hydroxylation reactions and provides a method for the consumption of peroxide as it is generated to minimize the accumulation of large quantities of peroxide. PMID:24988535

  18. Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products.

    PubMed

    Terent'ev, Alexander O; Borisov, Dmitry A; Vil', Vera A; Dembitsky, Valery M

    2014-01-01

    The present review describes the current status of synthetic five and six-membered cyclic peroxides such as 1,2-dioxolanes, 1,2,4-trioxolanes (ozonides), 1,2-dioxanes, 1,2-dioxenes, 1,2,4-trioxanes, and 1,2,4,5-tetraoxanes. The literature from 2000 onwards is surveyed to provide an update on synthesis of cyclic peroxides. The indicated period of time is, on the whole, characterized by the development of new efficient and scale-up methods for the preparation of these cyclic compounds. It was shown that cyclic peroxides remain unchanged throughout the course of a wide range of fundamental organic reactions. Due to these properties, the molecular structures can be greatly modified to give peroxide ring-retaining products. The chemistry of cyclic peroxides has attracted considerable attention, because these compounds are used in medicine for the design of antimalarial, antihelminthic, and antitumor agents. PMID:24454562

  19. Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

    PubMed Central

    Borisov, Dmitry A; Vil’, Vera A; Dembitsky, Valery M

    2014-01-01

    Summary The present review describes the current status of synthetic five and six-membered cyclic peroxides such as 1,2-dioxolanes, 1,2,4-trioxolanes (ozonides), 1,2-dioxanes, 1,2-dioxenes, 1,2,4-trioxanes, and 1,2,4,5-tetraoxanes. The literature from 2000 onwards is surveyed to provide an update on synthesis of cyclic peroxides. The indicated period of time is, on the whole, characterized by the development of new efficient and scale-up methods for the preparation of these cyclic compounds. It was shown that cyclic peroxides remain unchanged throughout the course of a wide range of fundamental organic reactions. Due to these properties, the molecular structures can be greatly modified to give peroxide ring-retaining products. The chemistry of cyclic peroxides has attracted considerable attention, because these compounds are used in medicine for the design of antimalarial, antihelminthic, and antitumor agents. PMID:24454562

  20. Degradation of the ethyl glucuronide content in hair by hydrogen peroxide and a non-destructive assay for oxidative hair treatment using infra-red spectroscopy.

    PubMed

    Ammann, Dominic; Becker, Roland; Kohl, Anka; Hänisch, Jessica; Nehls, Irene

    2014-11-01

    The assessment of quantification results of the alcohol abuse marker ethyl glucuronide (EtG) in hair in comparison to the cut-off values for the drinking behavior may be complicated by cosmetic hair bleaching. Thus, the impact of increasing exposure to hydrogen peroxide on the EtG content of hair was investigated. Simultaneously, the change of absorbance in the range of 1000-1100 cm(-1) indicative for the oxidation of cystine was investigated non-destructively by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) using pulverized portions of the respective hair samples. Hair samples treated with hydrogen peroxide consistently displayed a significantly increased absorbance at 1040 cm(-1) associated with the formation of cysteic acid. The EtG content decreased significantly if the hair was treated with alkaline hydrogen peroxide as during cosmetic bleaching. It could be shown that ATR-FTIR is capable of detecting an exposure to hydrogen peroxide when still no brightening was visible and already before the EtG content deteriorated significantly. Thus, hair samples suspected of having been exposed to oxidative treatment may be checked non-destructively by a readily available technique. This assay is also possible retrospectively after EtG extraction and using archived samples. PMID:25180828

  1. The AP2-like gene NsAP2 from water lily is involved in floral organogenesis and plant height.

    PubMed

    Luo, Huolin; Chen, Sumei; Jiang, Jiafu; Teng, Nianjun; Chen, Yu; Chen, Fadi

    2012-07-01

    APETALA2 (AP2) genes are ancient and widely distributed among the seed plants, and play an important role during the plant life cycle, acting as key regulators of many developmental processes. In this study, an AP2 homologue, NsAP2, was characterized from water lily (Nymphaea sp. cv. 'Yellow Prince') and is believed to be rather primitive in the evolution of the angiosperms. In situ RNA hybridization showed that NsAP2 transcript was present in all regions of the floral primordium, but had the highest level in the emerging floral organ primordium. After the differentiation of floral organs, NsAP2 was strongly expressed in sepals and petals, while low levels were found in stamens and carpels. The NsAP2 protein was suggested to be localized in the cell nucleus by onion transient expression experiment. Overexpression of NsAP2 in Arabidopsis led to more petal numbers, and Arabidopsis plants expressing NsAP2 exhibited higher plant height, which may be a result of down-regulated expression of GA2ox2 and GA2ox7. Our results indicated that the NsAP2 protein may function in flower organogenesis in water lily, and it is a promising gene for plant height improvement. PMID:22591856

  2. Genome-Wide Identification of the Target Genes of AP2-O, a Plasmodium AP2-Family Transcription Factor.

    PubMed

    Kaneko, Izumi; Iwanaga, Shiroh; Kato, Tomomi; Kobayashi, Issei; Yuda, Masao

    2015-05-01

    Stage-specific transcription is a fundamental biological process in the life cycle of the Plasmodium parasite. Proteins containing the AP2 DNA-binding domain are responsible for stage-specific transcriptional regulation and belong to the only known family of transcription factors in Plasmodium parasites. Comprehensive identification of their target genes will advance our understanding of the molecular basis of stage-specific transcriptional regulation and stage-specific parasite development. AP2-O is an AP2 family transcription factor that is expressed in the mosquito midgut-invading stage, called the ookinete, and is essential for normal morphogenesis of this stage. In this study, we identified the genome-wide target genes of AP2-O by chromatin immunoprecipitation-sequencing and elucidate how this AP2 family transcription factor contributes to the formation of this motile stage. The analysis revealed that AP2-O binds specifically to the upstream genomic regions of more than 500 genes, suggesting that approximately 10% of the parasite genome is directly regulated by AP2-O. These genes are involved in distinct biological processes such as morphogenesis, locomotion, midgut penetration, protection against mosquito immunity and preparation for subsequent oocyst development. This direct and global regulation by AP2-O provides a model for gene regulation in Plasmodium parasites and may explain how these parasites manage to control their complex life cycle using a small number of sequence-specific AP2 transcription factors. PMID:26018192

  3. Genome-Wide Identification of the Target Genes of AP2-O, a Plasmodium AP2-Family Transcription Factor

    PubMed Central

    Kaneko, Izumi; Iwanaga, Shiroh; Kato, Tomomi; Kobayashi, Issei; Yuda, Masao

    2015-01-01

    Stage-specific transcription is a fundamental biological process in the life cycle of the Plasmodium parasite. Proteins containing the AP2 DNA-binding domain are responsible for stage-specific transcriptional regulation and belong to the only known family of transcription factors in Plasmodium parasites. Comprehensive identification of their target genes will advance our understanding of the molecular basis of stage-specific transcriptional regulation and stage-specific parasite development. AP2-O is an AP2 family transcription factor that is expressed in the mosquito midgut-invading stage, called the ookinete, and is essential for normal morphogenesis of this stage. In this study, we identified the genome-wide target genes of AP2-O by chromatin immunoprecipitation-sequencing and elucidate how this AP2 family transcription factor contributes to the formation of this motile stage. The analysis revealed that AP2-O binds specifically to the upstream genomic regions of more than 500 genes, suggesting that approximately 10% of the parasite genome is directly regulated by AP2-O. These genes are involved in distinct biological processes such as morphogenesis, locomotion, midgut penetration, protection against mosquito immunity and preparation for subsequent oocyst development. This direct and global regulation by AP2-O provides a model for gene regulation in Plasmodium parasites and may explain how these parasites manage to control their complex life cycle using a small number of sequence-specific AP2 transcription factors. PMID:26018192

  4. Metallized solid rocket propellants based on AN/AP and PSAN/AP for access to space

    NASA Astrophysics Data System (ADS)

    Levi, S.; Signoriello, D.; Gabardi, A.; Molinari, M.; Galfetti, L.; Deluca, L. T.; Cianfanelli, S.; Klyakin, G. F.

    2009-09-01

    Solid rocket propellants based on dual mixes of inorganic crystalline oxidizers (ammonium nitrate (AN) and ammonium perchlorate (AP)) with binder and a mixture of micrometric-nanometric aluminum were investigated. Ammonium nitrate is a low-cost oxidizer, producing environment friendly combustion products but with lower specific impulse compared to AP. The better performance obtained with AP and the low quantity of toxic emissions obtained by using AN have suggested an interesting compromise based on a dual mixture of the two oxidizers. To improve the thermal response of raw AN, different types of phase stabilized AN (PSAN) and AN/AP co-crystals were investigated.

  5. Optimization of Alkaline Extraction and Bioactivities of Polysaccharides from Rhizome of Polygonatum odoratum

    PubMed Central

    Chen, Yong; Yin, Luoyi; Zhang, Xuejiao; Wang, Yan; Chen, Qiuzhi; Jin, Chenzhong; Wang, Jihua

    2014-01-01

    The present study is to explore the optimal extraction parameters, antioxidant activity, and antimicrobial activity of alkaline soluble polysaccharides from rhizome of Polygonatum odoratum. The optimal extraction parameters were determined as the following: NaOH concentration (A) 0.3 M, temperature (B) 80°C, ratio of NaOH to solid (C) 10-fold, and extraction time (D) 4 h, in which ratio of NaOH to solid was a key factor. The order of the factors was ratio of NaOH to solid (fold, C) > extraction temperature (°C, B) > NaOH concentration (M, A) > extraction time (h, D). The monosaccharide compositions of polysaccharides from P. odoratum were rhamnose, mannose, xylose, and arabinose with the molecular ratio of 31.78, 31.89, 11.11, and 1.00, respectively. The reducing power, the 1, 1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging rate, the hydroxyl radicals scavenging rate, and the inhibition rate to polyunsaturated fatty acid (PUFA) peroxidation of the alkaline soluble polysaccharides from P. odoratum at 1 mg/mL were 9.81%, 52.84%, 19.22%, and 19.42% of ascorbic acid at the same concentration, respectively. They also showed antimicrobial activity against pathogenic bacteria Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli. PMID:25093173

  6. Alkaline earth cation extraction from acid solution

    DOEpatents

    Dietz, Mark; Horwitz, E. Philip

    2003-01-01

    An extractant medium for extracting alkaline earth cations from an aqueous acidic sample solution is described as are a method and apparatus for using the same. The separation medium is free of diluent, free-flowing and particulate, and comprises a Crown ether that is a 4,4'(5')[C.sub.4 -C.sub.8 -alkylcyclohexano]18-Crown-6 dispersed on an inert substrate material.

  7. The alkaline earth intercalates of molybdenum disulfide

    NASA Technical Reports Server (NTRS)

    Somoano, R. B.; Hadek, V.; Rembaum, A.; Samson, S.; Woollam, J. A.

    1975-01-01

    Molybdenum disulfide has been intercalated with calcium and strontium by means of the liquid ammonia technique. Chemical, X-ray, and superconductivity data are presented. The X-ray data reveal a lowering of crystal symmetry and increase of complexity of the structure upon intercalation with the alkaline earth metals. The Ca and Sr intercalates start to superconduct at 4 and 5.6 K, respectively, and show considerable anisotropy regarding the critical magnetic field.

  8. Surfactant-enhanced alkaline flooding field project

    SciTech Connect

    French, T.R.

    1991-10-01

    The Tucker sand of Helper (KS) field is a candidate for surfactant-enhanced alkaline flooding. The geology of the Helper site is typical of many DOE Class I reservoirs. The Tucker sand of Helper field was deposited in a fluvial dominated deltaic environment. Helper oil can be mobilized with either chemical system 2 or chemical system 3, as described in this report. Oil fields in the Gulf Coast region are also good candidates for surfactant-enhanced alkaline flooding. The results from laboratory tests conducted in Berea sandstone cores with oil brine from Helper (KS) field are encouraging. The crude oil is viscous and non-acidic and, yet, was mobilized by the chemical formulations described in this report. Significant amounts of the oil were mobilized under simulated reservoir conditions. The results in Berea sandstone cores were encouraging and should be verified by tests with field core. Consumption of alkali, measured with field core, was very low. Surfactant loss appeared to be acceptable. Despite the good potential for mobilization of Helper oil, certain reservoir characteristics such as low permeability, compartmentalization, and shallow depth place constraints on applications of any chemical system in the Tucker sand. These constraints are typical of many DOE Class I reservoirs. Although Hepler field is not a perfect reservoir in which to apply surfactant- enhanced alkaline flooding, Hepler oil is particularly amenable to mobilization by surfactant-enhanced alkaline systems. A field test is recommended, dependent upon final evaluation of well logs and cores from the proposed pilot area. 14 refs., 21 figs., 10 tabs.

  9. Alkaline injection for enhanced oil recovery: a status report

    SciTech Connect

    Mayer, E.H.; Berg, R.L.; Carmichael, J.D.; Weinbrandt, R.M.

    1983-01-01

    In the past several years, there has been renewed interest in enhanced oil recovery (EOR) by alkaline injection. Alkaline solutions also are being used as preflushes in micellar/polymer projects. Several major field tests of alkaline flooding are planned, are in progress, or recently have been completed. Considerable basic research on alkaline injection has been published recently, and more is in progress. This paper summarizes known field tests and, where available, the amount of alkali injected and the performance results. Recent laboratory work, much sponsored by the U.S. DOE, and the findings are described. Alkaline flood field test plans for new projects are summarized.

  10. Alkaline flooding for enhanced oil recovery

    SciTech Connect

    Gittler, W.E.

    1983-09-01

    There are over 12 active projects of varying size using one of 3 major types of alkaline agents. These include sodium silicate, caustic soda, and soda ash. Among the largest pilots currently is the THUMS project in the Wilmington field, California. Plans called for the injection of a 4% weight concentration of sodium orthosilicate over a 60% PV. Through the first 3 yr, over 27 million bbl of chemicals have been injected. Gulf Oil is operating several alkaline floods, one of which is located off shore in the Quarantine Bay field, Louisiana. In this pilot, sodium hydroxide in a weight concentration of 5 to 12% is being injected. Belco Petroleum Corp. has reported that their pilot operating in the Isenhour Unit in Wyoming is using a .5% weight concentration of soda ash in conjunction with a polymer. Other uses for alkaline agents in chemical flooding include the use of silicate as a preflush or sacrificial agent in micellar/polymer and surfactant recovery systems. In addition, caustic has been tested in the surface-mixed caustic emulsion process while orthosilicate has been tested in a recovery method known as mobility-controlled caustic floods.

  11. Residual radiation studies at AP0

    SciTech Connect

    Alexander J Elwyn et al.

    2002-06-19

    The radiation environment at the NuMI experiment has received a lot of attention in the last few years in preparation for project construction. One important issue is the induced radioactivation of the components in the beam line and the shielding materials. This arises from irradiation by hadrons that are generated in the target. Since the level of the residual activity has to be considered when determining access procedures for maintenance during NuMI operation, an understanding of the properties of the remnant radiation is important. To this end, experimental studies were performed in the target vault at AP0 which is similar in design to the NuMI target area. Here 120 GeV protons bombard a target, generating the hadrons that produce the induced radioactivity. Two sets of samples each consisting of three small cylindrical or rectangular solids of iron and steel, one sample of aluminum, and one of concrete were irradiated. One set was hung just below the bottom of a module near the lithium lens (in-vault), and the other was placed on top of the modules downstream of this location (above-vault), just beneath the movable concrete roof of the vault at AP0. Further, four thin activation foils of Au, Au+Cd, In, and Al (along with small disks of the same iron, aluminum, and concrete samples discussed above) were mounted on four 10.2 cm diameter Al disks, one placed on the in-vault module and three at above-vault downstream locations as well. The radioactivity of all these materials on the 10.2 cm Al disks was determined at the Radioisotope Analysis Facility in an attempt to characterize the radionuclides produced during irradiation. The activities of the thin foils were employed in an effort to unfold a spectrum of the neutrons produced during the hadronic cascades in the target. The MARS Monte Carlo code (MO95, MO00) was used to predict and analyze the residual radiation produced during the beam irradiation. New subroutines have been developed for the MARS14 version

  12. Paraquat and NADPH-dependent lipid peroxidation in lung microsomes

    SciTech Connect

    Misra, H.P.; Gorsky, L.D.

    1981-10-10

    Since there exists some controversy in the literature as to whether paraquat augments microsomal lipid peroxidation via superoxide anion (O/sub 2//sup -/), the role of paraquat and active oxygen species in NADPH-dependent lung microsomal lipid peroxidation was investigated. Incubation of buffered aerobic mixture of bovine lung microsome and NADPH, in the presence or absence of exogenously added iron, resulted in a progressive formation of lipid peroxides whose accumulation could be followed at 535 nm as malondialdehyde. Paraquat strongly inhibited this lipid peroxidation, Thus, malondialydehyde formation was 50% inhibited by 4 X 10/sup -5/ M paraquat in the reaction mixture. The malondialdehyde color development by lipid peroxides was not affected by this concentration of paraquat. Lipid peroxidation was also strongly inhibited by singlet oxygen scavengers, e.g. dimethylfuran and diphenylfuran, and by catalase. Hydroxyl radical scavengers, e.g. mannitol, benzoate, and ethanol, had little effect in malondialydehyde production. Superoxide dismutase, which removes O/sub 2//sup -/ efficiently, did not inhibit malondialdehyde production by lung microsomes and rather enhanced its formation. A scheme in which paraquat and active O/sub 2/ species may be involved with microsomal lipid peroxidation is presented.

  13. Resistance to lipid peroxidation by cultured neoplastic cells

    SciTech Connect

    Arneson, R.M.; Wander, J.D.; Cabot, M.C.; Tan, E.L.; Schenley, R.L.; Hsie, A.W.

    1982-01-01

    The membranes of murine neuroblastoma cells (C1300) and human leukemia cells (HL-60) exhibit markedly increased resistance to peroxidation and undifferentiated Friend erythroleukemia cells were highly resistant to peroxidation. These findings suggest that high resistance to peroxidation and changes in the level of resistance occur commonly in cultured cells. Both cytosolic and membrane-associated factors that can prevent the onset of lipid peroxidation are present in differentiating neuroblastoma cells. A highly sensitive, single-phase assay for antioxidant activity failed to detect the presence of an antioxidant that could be associated with increased resistance to peroxidation in neuroblastoma cells. Likewise, lipid analyses of neuroblastoma cells revealed no parameter that could be related to this increase; however, this resistance phenomenon is abolished by adding arachidonic acid to the culture medium at levels that do not affect cell growth or viability. Protective factors exist in the cytosolic fraction of rat liver homogenate, which are able to neutralize the toxic products of lipid peroxidation rather than prevent the initiation of peroxidation. These protective factors were detected, and could possibly be isolated, by a cytotoxicity assay employing Chinese hamster ovary cells. In the course of this work, we discovered an antioxidant artifact that is widely distributed in commercial tissue culture media. A simple procedure has been developed to detect this antioxidant in lots of culture media.

  14. Kinetics of Platinum-Catalyzed Decomposition of Hydrogen Peroxide

    NASA Astrophysics Data System (ADS)

    Vetter, Tiffany A.; Colombo, D. Philip, Jr.

    2003-07-01

    CIBA Vision Corporation markets a contact lens cleaning system that consists of an AOSEPT disinfectant solution and an AOSEPT lens cup. The disinfectant is a buffered 3.0% m/v hydrogen peroxide solution and the cup includes a platinum-coated AOSEPT disc. The hydrogen peroxide disinfects by killing bacteria, fungi, and viruses found on the contact lenses. Because the concentration of hydrogen peroxide needed to disinfect is irritating to eyes, the hydrogen peroxide needs to be neutralized, or decomposed, before the contact lenses can be used again. A general chemistry experiment is described where the kinetics of the catalyzed decomposition of the hydrogen peroxide are studied by measuring the amount of oxygen generated as a function of time. The order of the reaction with respect to the hydrogen peroxide, the rate constant, and the energy of activation are determined. The integrated rate law is used to determine the time required to decompose the hydrogen peroxide to a concentration that is safe for eyes.

  15. Oxygen Mass Flow Rate Generated for Monitoring Hydrogen Peroxide Stability

    NASA Technical Reports Server (NTRS)

    Ross, H. Richard

    2002-01-01

    Recent interest in propellants with non-toxic reaction products has led to a resurgence of interest in hydrogen peroxide for various propellant applications. Because peroxide is sensitive to contaminants, material interactions, stability and storage issues, monitoring decomposition rates is important. Stennis Space Center (SSC) uses thermocouples to monitor bulk fluid temperature (heat evolution) to determine reaction rates. Unfortunately, large temperature rises are required to offset the heat lost into the surrounding fluid. Also, tank penetration to accomodate a thermocouple can entail modification of a tank or line and act as a source of contamination. The paper evaluates a method for monitoring oxygen evolution as a means to determine peroxide stability. Oxygen generation is not only directly related to peroxide decomposition, but occurs immediately. Measuring peroxide temperature to monitor peroxide stability has significant limitations. The bulk decomposition of 1% / week in a large volume tank can produce in excess of 30 cc / min. This oxygen flow rate corresponds to an equivalent temperature rise of approximately 14 millidegrees C, which is difficult to measure reliably. Thus, if heat transfer were included, there would be no temperature rise. Temperature changes from the surrounding environment and heat lost to the peroxide will also mask potential problems. The use of oxygen flow measurements provides an ultra sensitive technique for monitoring reaction events and will provide an earlier indication of an abnormal decomposition when compared to measuring temperature rise.

  16. AP-102/104 Retrieval control system qualification test procedure

    SciTech Connect

    RIECK, C.A.

    1999-05-18

    This Qualification Test Procedure documents the results of the qualification testing that was performed on the Project W-211, ''Initial Tank Retrieval Systems,'' retrieval control system (RCS) for tanks 241-AP-102 and 241-AP-104. The results confirm that the RCS has been programmed correctly and that the two related hardware enclosures have been assembled in accordance with the design documents.

  17. Is the Shine off the A.P. Apple?

    ERIC Educational Resources Information Center

    Hurwitz, Nina; Hurwitz, Sol

    2003-01-01

    Describes challenges facing College Board's efforts to expand Advanced Placement (A.P.) courses to provide equal access to previously underserved low-performing urban and rural school students while maintaining the program's high academic standards. Includes list of strategies school boards can use to achieve greater access to A.P. courses while…

  18. AP233: An Information Model for Systems Engineering

    NASA Technical Reports Server (NTRS)

    Siebes, Georg

    2009-01-01

    In today's world, information is abundant. We have no problems generating it. But we are challenged to find, organize, and exchange information. center dot A standardized model of information can help. Such a model nearly completed its development for Systems Engineering. It is referred to as AP233 (AP = Application Protocol).

  19. Status of the Advanced Photon Source (APS) linear accelerator

    SciTech Connect

    White, M.; Berg, W.; Fuja, R.; Grelick, A.; Mavrogenes, G.; Nassiri, A.; Russell, T.; Wesolowski, W.

    1993-08-01

    A 2856-MHz S-band, 450-MeV electron/positron linear accelerator is the first part of the injector for the Advanced Photon Source (APS) 7-GeV storage ring. Construction of the APS linac is currently nearing completion, and commissioning will begin in July 1993. The linac and its current status are discussed in this paper.

  20. Raising Rigor, Getting Results: Lessons Learned from AP Expansion

    ERIC Educational Resources Information Center

    Wakelyn, David

    2009-01-01

    Advanced Placement (AP), which enables high school students to take introductory college-level courses, is the nation's oldest example of a rigorous, common curriculum. Students who score well on AP exams are more likely to persist in college and earn a degree. The Advanced Placement Expansion project of the National Governors Association Center…

  1. The APS SASE FEL : modeling and code comparison.

    SciTech Connect

    Biedron, S. G.

    1999-04-20

    A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

  2. AP-42 ADDITIONS AND REVISIONS - RUBBER PRODUCTS MANUFACTURING

    EPA Science Inventory

    This project develops emission factors, etc., for the rubber products industry which are appended to AP-42. AP42 is a massive collection of material which describes processes which generate air emissions and presents emission factors and control effectiveness information. As res...

  3. A Closer Examination of the Academic Benefits of AP

    ERIC Educational Resources Information Center

    McKillip, Mary E. M.; Rawls, Anita

    2013-01-01

    The authors sought to better understand the relationship between students participating in the Advanced Placement (AP) program and subsequent performance on the Scholastic Aptitude Test (SAT). Focusing on students graduating from U.S. public high schools in 2010, the authors used propensity scores to match junior year AP examinees in 3 subjects to…

  4. AP-42 ADDITIONS AND REVISIONS - LANDFILLS (COMBUSTION CONTROLS)

    EPA Science Inventory

    This project develops emission factors, etc., for landfills, in particular for combustion devices fed by landfill gas, for incorporation into AP-42. AP-42 is a massive collection of information concerning processes which generate air emissions and presents emission factors and co...

  5. Performance of Project Advance Students on the AP Biology Examination.

    ERIC Educational Resources Information Center

    Mercurio, Joseph; And Others

    1984-01-01

    Compared performance of Project Advance biology students (N=60) with Advanced Placement (AP) candidates (N=15,947) nationally on College Entrance Examination Board AP biology test. The research, conducted to determine comparability of the program as valid measures of academic achievement, determined that Project Advance students scored above the…

  6. Data-Based Decision Making: The Road to AP Equity

    ERIC Educational Resources Information Center

    Edwards, Kelcey; Duggan, Odette

    2012-01-01

    Presented at the Advanced Placement Annual Conference (APAC) in Lake Buena Vista, FL in July 2012. This presentation reviews concepts central to achieving equitable AP access and success for all willing and academically prepared students. We analyze trends in participation and performance by race/ethnicity from the AP Report to the Nation and…

  7. The fate of added alkalinity in model scenarios of ocean alkalinization

    NASA Astrophysics Data System (ADS)

    Ferrer González, Miriam; Ilyina, Tatiana

    2014-05-01

    The deliberate large-scale manipulation of the Earth's climate (geo-engineering) has been proposed to mitigate climate change and ocean acidification. Whilst the mitigation potential of these technologies could sound promising, they may also pose many environmental risks. Our research aims at exploring the ocean-based carbon dioxide removal method of alkalinity enhancement. Its mitigation potential to reduce atmospheric CO2 and counteract the consequences of ocean acidification, risks and unintended consequences are studied. In order to tackle these questions, different scenarios are implemented in the state-of-the-art Earth system model of the Max Planck Institute for Meteorology. The model configuration is based on the 5th phase of the coupled model intercomparison project following a high CO2 future climate change scenario RCP8.5 (in which radiative forcing rises to 8.5 W/m² in 2100). Two different scenarios are performed where the alkalinity is artificially added globally uniformly in the upper ocean. In the first scenario, alkalinity is increased as a pulse by doubling natural values of the first 12 meters. In the second scenario we add alkalinity into the same ocean layer such that the atmospheric CO2 concentration is reduced from RCP8.5 to RCP4.5 levels (with the radiative forcing of 4.5 W/m² in 2100). We investigate the fate of the added alkalinity in these two scenarios and compare the differences in alkalinity budgets. In order to increase oceanic CO2 uptake from the atmosphere, enhanced alkalinity has to stay in the upper ocean. Once the alkalinity is added, it will become part of the biogeochemical cycles and it will be distributed with the ocean currents. Therefore, we are particularly interested in the residence time of the added alkalinity at the surface. Variations in CO2 partial pressure, seawater pH and saturation state of carbonate minerals produced in the implemented scenarios will be presented. Collateral changes in ocean biogeochemistry and

  8. Purification and concentration of alkaline phosphatase by selective permeabilization of Escherichia coli using reverse micellar solutions.

    PubMed

    Bansal-Mutalik, Ritu; Gaikar, Vilas G

    2003-01-01

    Recovery of alkaline phosphatase (AP) from the periplasm of Escherichia coli using reverse micellar solutions (RMSs) of sodium dioctyl sulfosuccinate (AOT) in aliphatic hydrocarbons has been attempted. A variety of surface-active agents, solvents, and reverse micellar conditions were screened, and an excellent recovery of the enzyme in a concentrated form, with a high purification factor, was obtained in a single-step process. The permeabilization process strongly depended on the water content of the RMS as well as on the amount of water coating the microbial cell surface. The product was almost free from nucleic acids. In addition, because of the low affinity of AOT and the organic solvent for the aqueous phase, contamination by the permeabilizing agents would also be negligible. PMID:14656146

  9. GPI-AP release in cellular, developmental, and reproductive biology.

    PubMed

    Fujihara, Yoshitaka; Ikawa, Masahito

    2016-04-01

    Glycosylphosphatidylinositol-anchored proteins (GPI-APs) contain a covalently linked GPI anchor located on outer cell membranes. GPI-APs are ubiquitously conserved from protozoa to vertebrates and are critical for physiological events such as development, immunity, and neurogenesis in vertebrates. Both membrane-anchored and soluble GPI-APs play a role in regulating their protein conformation and functional properties. Several pathways mediate the release of GPI-APs from the plasma membrane by vesiculation or cleavage. Phospholipases and putative substrate-specific GPI-AP-releasing enzymes, such as NOTUM, glycerophosphodiesterase 2, and angiotensin-converting enzyme, have been characterized in mammals. Here, the protein modifications resulting from the cleavage of the GPI anchor are discussed in the context of its physiological functions. PMID:26593072

  10. The AP Exam: Is This How People Learn?

    NASA Astrophysics Data System (ADS)

    Eisenkraft, Arthur

    2001-04-01

    The AP Physics course is often the most rigorous experience a student will have in high school. The culminating AP exam tests problem solving skills using traditional questions that are found in most freshmen books. The nature of the test imparts a specific focus on the course, which in turn shapes the students' impression of physics. Over the past decade, we have been discovering a great deal about how people learn in general. We have also learned specifically about the inadequacies of traditional physics instruction. Has the AP exam kept pace with this new knowledge? Can the AP exam be altered in order to require a different type of instruction that is informed by cognitive research? What would the new exam look like? Samples of exam questions from AP Exams will be viewed through the lens of cognitive research. Alternative physics challenges will be presented and the difficulties in grading these questions noted.

  11. Evolutionary period changes in the rapidly oscillating Ap stars

    NASA Technical Reports Server (NTRS)

    Heller, Clayton H.; Kawaler, Steven D.

    1988-01-01

    Preliminary computations of the asymptotic p-mode frequency spacings, and their time derivatives, are presented for a grid of evolutionary models of the rapidly oscillating Ap ('roAp') stars. It is shown how the frequency spacings depend on stellar mass, metallicity, and evolutionary stage. The frequency spacings observed in two of the roAp stars indicate that they either are main-sequence objects or have evolved off of the main sequence, depending on how the pulsation spectrum is interpreted. A way to remove this ambiguity is suggested: secular evolutionary changes in the pulsation frequencies may be measurable if the roAp stars have evolved off of the main sequence. In principle, this determination may be made for the roAp star HR 1217 with existing data.

  12. Intraoral chemical burn from use of 3% hydrogen peroxide.

    PubMed

    Rostami, Arash M; Brooks, John K

    2011-01-01

    Injudicious use of over-the-counter 3% hydrogen peroxide, a relatively potent oxidative agent, can result in a chemical burn to the oral mucosa. This article describes a patient who rinsed with 3% hydrogen peroxide for periods of more than two minutes as a self-prescribed remedy for oral discomfort following seafood ingestion. Subsequently, the patient experienced pain and extensive chemical burns of the sublingual and buccal mucosa and gingiva. In addition, the buccal mucosa underwent necrosis. Prolonged oral mucosal contact with 3% hydrogen peroxide is ill-advised. PMID:22313923

  13. Simulated afterburner performance with hydrogen peroxide injection for thrust augmentation

    NASA Technical Reports Server (NTRS)

    Metzler, Allen J; Grobman, Jack S

    1956-01-01

    Combustion performance of three afterburner configurations was evaluated at simulated altitude flight conditions with liquid augmentation to the primary combustor. Afterburner combustion efficiency and stability were better with injection of high-strength hydrogen peroxide than with no injection or with water injection. Improvements were observed in afterburner configurations with and without flameholders and in a short-length afterburner. At a peroxide-air ratio of 0.3, combustion was stable and 85 to 90 percent efficient in all configurations tested. Calculated augmented net-thrust ratios for peroxide injection with afterburning were approximately 60 percent greater than those for water injection.

  14. Lipocarbazole, an efficient lipid peroxidation inhibitor anchored in the membrane.

    PubMed

    Fabre, Gabin; Hänchen, Anne; Calliste, Claude-Alain; Berka, Karel; Banala, Srinivas; Otyepka, Michal; Süssmuth, Roderich D; Trouillas, Patrick

    2015-08-01

    Lipid peroxidation is a major deleterious effect caused by oxidative stress. It is involved in various diseases such as atherosclerosis, rheumatoid arthritis and neurodegenerative diseases. In order to inhibit lipid peroxidation, antioxidants must efficiently scavenge free radicals and penetrate inside biological membranes. Lipocarbazole has recently been shown to be a powerful antioxidant in solution. Here, we show its powerful capacity as lipid peroxidation inhibitor. Its mechanism of action is rationalized based on molecular dynamics simulations on a biomembrane model, quantum calculations and experimental evaluation. The role of the lipocarbazole side chain is particularly highlighted as a critical chemical feature responsible for its antioxidant activity. PMID:26068016

  15. Uranyl peroxide enhanced nuclear fuel corrosion in seawater

    PubMed Central

    Armstrong, Christopher R.; Nyman, May; Shvareva, Tatiana; Sigmon, Ginger E.; Burns, Peter C.; Navrotsky, Alexandra

    2012-01-01

    The Fukushima-Daiichi nuclear accident brought together compromised irradiated fuel and large amounts of seawater in a high radiation field. Based on newly acquired thermochemical data for a series of uranyl peroxide compounds containing charge-balancing alkali cations, here we show that nanoscale cage clusters containing as many as 60 uranyl ions, bonded through peroxide and hydroxide bridges, are likely to form in solution or as precipitates under such conditions. These species will enhance the corrosion of the damaged fuel and, being thermodynamically stable and kinetically persistent in the absence of peroxide, they can potentially transport uranium over long distances. PMID:22308442

  16. Replacement of hydrogen peroxide cleaning with oxygen plasma

    NASA Astrophysics Data System (ADS)

    Adams, B. E.

    1992-03-01

    Comparison between the standard peroxide cleaning method and an oxygen plasma modified version was run on thin film bond monitors. The plasma modified version substituted oxygen plasma for the peroxide cleaning step in the process and reduced the DI rinse water temperature from 75 C to 25 C. A direct surface cleanliness comparison was made between the two cleaning methods using Auger spectroscopy. A beam lead and ribbon bonding experiment was also run on plasma-cleaned networks. Results of both experiments indicate that plasma cleaning is superior to peroxide cleaning and that reliable bonding can be done on plasma-cleaned thin film networks.

  17. Top-up operation experience at APS.

    SciTech Connect

    Emery, L.

    1999-03-31

    The Advanced Photon Source (APS) is a 7-OeV, third-generation synchrotrons radiation source. To provide more stable beam for users, in September 1998 we began commissioning a new operating mode called ''top-up.'' In this mode, the beam current does not decay but is maintained at a high level using frequent injection, while photon shutters are open and photon beams are delivered to users. The hardware, software, and safety requirements for top-up will be reported. Safety issues related to injection with open photon shutters are covered in companion papers in this conference. Recent operational experience includes testing aspects of top-up injection and delivering beam to X-ray users for a few hours with fractional current stability of 10{sup {minus}3}. We expect to run several top-up operation shifts in Spring 1999. Issues of importance are orbit and emittance transients during the injection and scheduling of injection pulses for the convenience of users.

  18. High Pressure Reverse Flow APS Engine

    NASA Technical Reports Server (NTRS)

    Senneff, J. M.

    1972-01-01

    A design and test demonstration effort was undertaken to evaluate the concept of the reverse flow engine for the APS engine application. The 1500 lb (6672 N) thrust engine was designed to operate on gaseous hydrogen and gaseous oxygen propellants at a mixture ratio of 4 and to achieve the objective performance of 435 sec (4266 Nsec/kg) specific impulse. Superimposed durability requirements called for a million-cycle capability with 50 hours duration. The program was undertaken as a series of tasks including the initial preliminary design, design of critical test components and finally, the design and demonstration of an altitude engine which could be used interchangeably to examine operating parameters as well as to demonstrate the capability of the concept. The program results are reported with data to indicate that all of the program objectives were met or exceeded within the course of testing on the program. The analysis effort undertaken is also reported in detail and supplemented with test data in some cases where prior definitions could not be made. The results are contained of these analyses as well as the test results conducted throughout the course of the program. Finally, the test data and analytical results were combined to allow recommendations for a flight weight design. This preliminary design effort is also detailed.

  19. Tissue Non-specific Alkaline Phosphatase (TNAP) in Vessels of the Brain.

    PubMed

    Deracinois, Barbara; Lenfant, Anne-Marie; Dehouck, Marie-Pierre; Flahaut, Christophe

    2015-01-01

    The microvessels of the brain represent around 3-4 % of the brain compartment but constitute the most important length (400 miles) and surface of exchange (20 m(2)) between the blood and the parenchyma of brain. Under influence of surrounding tissues, the brain microvessel endothelium expresses a specific phenotype that regulates and restricts the entry of compounds and cells from blood to brain, and defined the so-called blood-brain barrier (BBB). Evidences that alkaline phosphatase (AP) is a characteristic feature of the BBB phenotype that allows differentiating capillary endothelial cells from brain to those of the periphery have rapidly emerge. Thenceforth, AP has been rapidly used as a biomarker of the blood-brain barrier phenotype. In fact, brain capillary endothelial cells (BCECs) express exclusively tissue non-specific alkaline phosphatase (TNAP). There are several lines of evidence in favour of an important role for TNAP in brain function. TNAP is thought to be responsible for the control of transport of some compounds across the plasma membrane of the BCECs. Here, we report that levamisole-mediated inhibition of TNAP provokes an increase of the permeability to Lucifer Yellow of the endothelial monolayer. Moreover, we illustrate the disruption of the cytoskeleton organization. Interestingly, all observed effects were reversible 24 h after levamisole removal and correlated with the return of a full activity of the TNAP. This reversible effect remains to be studied in details to evaluate the potentiality of a levamisole treatment to enhance the entry of drugs in the brain parenchyma. PMID:26219710

  20. Stable magnesium peroxide at high pressure.

    PubMed

    Lobanov, Sergey S; Zhu, Qiang; Holtgrewe, Nicholas; Prescher, Clemens; Prakapenka, Vitali B; Oganov, Artem R; Goncharov, Alexander F

    2015-01-01

    Rocky planets are thought to comprise compounds of Mg and O as these are among the most abundant elements, but knowledge of their stable phases may be incomplete. MgO is known to be remarkably stable to very high pressure and chemically inert under reduced condition of the Earth's lower mantle. However, in exoplanets oxygen may be a more abundant constituent. Here, using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we show that MgO and oxygen react at pressures above 96 GPa and T = 2150 K with the formation of I4/mcm MgO2. Raman spectroscopy detects the presence of a peroxide ion (O2(2-)) in the synthesized material as well as in the recovered specimen. Likewise, energy-dispersive x-ray spectroscopy confirms that the recovered sample has higher oxygen content than pure MgO. Our finding suggests that MgO2 may be present together or instead of MgO in rocky mantles and rocky planetary cores under highly oxidized conditions. PMID:26323635

  1. Inactivation of rabies virus by hydrogen peroxide.

    PubMed

    Abd-Elghaffar, Asmaa A; Ali, Amal E; Boseila, Abeer A; Amin, Magdy A

    2016-02-01

    Development of safe and protective vaccines against infectious pathogens remains a challenge. Inactivation of rabies virus is a critical step in the production of vaccines and other research reagents. Beta-propiolactone (βPL); the currently used inactivating agent for rabies virus is expensive and proved to be carcinogenic in animals. This study aimed to investigate the ability of hydrogen peroxide (H2O2) to irreversibly inactivate rabies virus without affecting its antigenicity and immunogenicity in pursuit of finding safe, effective and inexpensive alternative inactivating agents. H2O2 3% rapidly inactivated a Vero cell adapted fixed rabies virus strain designated as FRV/K within 2h of exposure without affecting its antigenicity or immunogenicity. No residual infectious virus was detected and the H2O2-inactivated vaccine proved to be safe and effective when compared with the same virus harvest inactivated with the classical inactivating agent βPL. Mice immunized with H2O2-inactivated rabies virus produced sufficient level of antibodies and were protected when challenged with lethal CVS virus. These findings reinforce the idea that H2O2 can replace βPL as inactivating agent for rabies virus to reduce time and cost of inactivation process. PMID:26731189

  2. Materials Compatibility Testing in Concentrated Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Boxwell, R.; Bromley, G.; Mason, D.; Crockett, D.; Martinez, L.; McNeal, C.; Lyles, G. (Technical Monitor)

    2000-01-01

    Materials test methods from the 1960's have been used as a starting point in evaluating materials for today's space launch vehicles. These established test methods have been modified to incorporate today's analytical laboratory equipment. The Orbital test objective was to test a wide range of materials to incorporate the revolution in polymer and composite materials that has occurred since the 1960's. Testing is accomplished in 3 stages from rough screening to detailed analytical tests. Several interesting test observations have been made during this testing and are included in the paper. A summary of the set-up, test and evaluation of long-term storage sub-scale tanks is also included. This sub-scale tank test lasted for a 7-month duration prior to being stopped due to a polar boss material breakdown. Chemical evaluations of the hydrogen peroxide and residue left on the polar boss surface identify the material breakdown quite clearly. The paper concludes with recommendations for future testing and a specific effort underway within the industry to standardize the test methods used in evaluating materials.

  3. Locating bomb factories by detecting hydrogen peroxide.

    PubMed

    Romolo, Francesco Saverio; Connell, Samantha; Ferrari, Carlotta; Suarez, Guillaume; Sauvain, Jean-Jacques; Hopf, Nancy B

    2016-11-01

    The analytical capability to detect hydrogen peroxide vapour can play a key role in localizing a site where a H2O2 based Improvised Explosive (IE) is manufactured. In security activities it is very important to obtain information in a short time. For this reason, an analytical method to be used in security activity needs portable devices. The authors have developed the first analytical method based on a portable luminometer, specifically designed and validated to locate IE manufacturing sites using quantitative on-site vapour analysis for H2O2. The method was tested both indoor and outdoor. The results demonstrate that the detection of H2O2 vapours could allow police forces to locate the site, while terrorists are preparing an attack. The collected data are also very important in developing new sensors, able to give an early alarm if located at a proper distance from a site where an H2O2 based IE is prepared. PMID:27591582

  4. Vibrationally mediated photodissociation of hydrogen peroxide

    SciTech Connect

    Ticich, T.M.; Likar, M.D.; Duebal, H.; Butler, L.J.; Crim, F.F.

    1987-11-15

    Vibrationally mediated photodissociation is a means of studying the spectroscopy of bound vibrational overtone states and of probing the electronic photodissociation dynamics of highly vibrationally excited molecules. In these experiments, a highly vibrationally excited hydrogen peroxide molecule prepared by initial excitation in the region of the third (4..nu../sub OH/) or fourth (5..nu../sub OH/) overtone of the OH stretching vibration absorbs an additional photon to dissociate to OH fragments whose individual quantum state populations are measured by laser induced fluorescence. This technique is a means of obtaining excitation spectra for bound highly vibrationally excited states and confirms the accuracy of a model that incorporates the role of the torsional vibration in the vibrational overtone spectroscopy. The photodissociation dynamics of highly vibrationally excited molecules are substantially different from those observed for dissociation by single photons of comparable or greater energy. Approximately 11% of the OH fragments formed in the vibrationally mediated photodissociation through 4..nu../sub OH/ are vibrationally excited as compared to an unobservable amount (less than or equal to2%) in the single photon ultraviolet dissociation.

  5. Molecular evolution of hydrogen peroxide degrading enzymes.

    PubMed

    Zámocký, Marcel; Gasselhuber, Bernhard; Furtmüller, Paul G; Obinger, Christian

    2012-09-15

    For efficient removal of intra- and/or extracellular hydrogen peroxide by dismutation to harmless dioxygen and water (2H(2)O(2) → O(2) + 2H(2)O), nature designed three metalloenzyme families that differ in oligomeric organization, monomer architecture as well as active site geometry and catalytic residues. Here we report on the updated reconstruction of the molecular phylogeny of these three gene families. Ubiquitous typical (monofunctional) heme catalases are found in all domains of life showing a high structural conservation. Their evolution was directed from large subunit towards small subunit proteins and further to fused proteins where the catalase fold was retained but lost its original functionality. Bifunctional catalase-peroxidases were at the origin of one of the two main heme peroxidase superfamilies (i.e. peroxidase-catalase superfamily) and constitute a protein family predominantly present among eubacteria and archaea, but two evolutionary branches are also found in the eukaryotic world. Non-heme manganese catalases are a relatively small protein family with very old roots only present among bacteria and archaea. Phylogenetic analyses of the three protein families reveal features typical (i) for the evolution of whole genomes as well as (ii) for specific evolutionary events including horizontal gene transfer, paralog formation and gene fusion. As catalases have reached a striking diversity among prokaryotic and eukaryotic pathogens, understanding their phylogenetic and molecular relationship and function will contribute to drug design for prevention of diseases of humans, animals and plants. PMID:22330759

  6. Stable magnesium peroxide at high pressure

    PubMed Central

    Lobanov, Sergey S.; Zhu, Qiang; Holtgrewe, Nicholas; Prescher, Clemens; Prakapenka, Vitali B.; Oganov, Artem R.; Goncharov, Alexander F.

    2015-01-01

    Rocky planets are thought to comprise compounds of Mg and O as these are among the most abundant elements, but knowledge of their stable phases may be incomplete. MgO is known to be remarkably stable to very high pressure and chemically inert under reduced condition of the Earth’s lower mantle. However, in exoplanets oxygen may be a more abundant constituent. Here, using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we show that MgO and oxygen react at pressures above 96 GPa and T = 2150 K with the formation of I4/mcm MgO2. Raman spectroscopy detects the presence of a peroxide ion (O22−) in the synthesized material as well as in the recovered specimen. Likewise, energy-dispersive x-ray spectroscopy confirms that the recovered sample has higher oxygen content than pure MgO. Our finding suggests that MgO2 may be present together or instead of MgO in rocky mantles and rocky planetary cores under highly oxidized conditions. PMID:26323635

  7. Predictive Validity Study of the APS Writing and Reading Tests [and] Validating Placement Rules for the APS Writing Test.

    ERIC Educational Resources Information Center

    College of the Canyons, Valencia, CA. Office of Institutional Development.

    California's College of the Canyons has used the College Board Assessment and Placement Services (APS) test to assess students' abilities in basic and college English since spring 1993. These two reports summarize data from a May 1994 study of the predictive validity of the APS writing and reading tests and a June 1994 effort to validate the cut…

  8. Thermal Decomposition Characteristics of Orthorhombic Ammonium Perchlorate (o-AP) and an 0-AP/HTPB-Based Propellant

    SciTech Connect

    BEHRENS JR.,RICHARD; MINIER,LEANNA M.G.

    1999-10-25

    A study to characterize the low-temperature reactive processes for o-AP and an AP/HTPB-based propellant (class 1.3) is being conducted in the laboratory using the techniques of simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) and scanning electron microscopy (SEM). The results presented in this paper are a follow up of the previous work that showed the overall decomposition to be complex and controlled by both physical and chemical processes. The decomposition is characterized by the occurrence of one major event that consumes up to {approx}35% of the AP, depending upon particle size, and leaves behind a porous agglomerate of AP. The major gaseous products released during this event include H{sub 2}O, O{sub 2}, Cl{sub 2}, N{sub 2}O and HCl. The recent efforts provide further insight into the decomposition processes for o-AP. The temporal behaviors of the gas formation rates (GFRs) for the products indicate that the major decomposition event consists of three chemical channels. The first and third channels are affected by the pressure in the reaction cell and occur at the surface or in the gas phase above the surface of the AP particles. The second channel is not affected by pressure and accounts for the solid-phase reactions characteristic of o-AP. The third channel involves the interactions of the decomposition products with the surface of the AP. SEM images of partially decomposed o-AP provide insight to how the morphology changes as the decomposition progresses. A conceptual model has been developed, based upon the STMBMS and SEM results, that provides a basic description of the processes. The thermal decomposition characteristics of the propellant are evaluated from the identities of the products and the temporal behaviors of their GFRs. First, the volatile components in the propellant evolve from the propellant as it is heated. Second, the hot AP (and HClO{sub 4}) at the AP-binder interface oxidize the binder through reactions that

  9. Baicalein Attenuates Oxidative Stress-Induced Expression of Matrix Metalloproteinase-1 by Regulating the ERK/JNK/AP-1 Pathway in Human Keratinocytes

    PubMed Central

    Kim, Ki Cheon; Kang, Sam Sik; Lee, Jongsung; Park, Deokhoon; Hyun, Jin Won

    2012-01-01

    The matrix metalloproteinase (MMP) family is involved in the breakdown of the extracellular matrix during normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as pathological aging, arthritis, and metastasis. Oxidative conditions generate reactive oxygen species (ROS) (e.g., hydrogen peroxide [H2O2]) in cells, which subsequently induce the synthesis of matrix metalloproteinase-1 (MMP-1). MMP-1, an interstitial collagenase, in turn stimulates an aging phenomenon. In this study, baicalein (5,6,7-trihydroxyflavone) was investigated for its in vitro activity against H2O2-induced damage using a human skin keratinocyte model. Baicalein pretreatment significantly inhibited H2O2-induced up-regulation of MMP-1 mRNA, MMP-1 protein expression and MMP-1 activity in cultured HaCaT keratinocytes. In addition, baicalein decreased the transcriptional activity of activator protein-1 (AP-1) and the expression of c-Fos and c-Jun, both components of the heterodimeric AP-1 transcription factor. Furthermore, baicalein reduced phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK), which are upstream of the AP-1 transcription factor. The results of this study suggest that baicalein is involved in the inhibition of oxidative stress-induced expression of MMP-1 via inactivation of the ERK/JNK/AP-1 signaling pathway. PMID:24116275

  10. Catalytic hydroxylation of benzoic acid by hydrogen peroxide

    SciTech Connect

    Pulippurasseril, C.R.; Filippova, T.Yu.; Dedov, A.G.

    1992-12-31

    An effective catalytic system based on Fe(III) and surfactants is proposed for the hydroxylation of benozic acid by hydrogen peroxide in an aqueous medium at a temperature of 30-80{degrees}C. 8 refs., 1 tab.

  11. Artifact peroxides produced during cryogenic sampling of ambient air

    NASA Astrophysics Data System (ADS)

    Staffelbach, Thomas; Neftel, Albrecht; Dasgupta, Purnendu K.

    Peroxides were found to be produced as artifacts during cryogenic sampling with Horibe traps. Cryogenic trap sampling was compared to collection with a wet effluent diffusion denuder and a Nafion membrane diffusion denuder. Hydrogen peroxide and hydroxymethyl hydroperoxide measured in the cryogenic trap samples were significantly higher. In comparison, no evidence of artifact methyl hydroperoxide production was found. The amount of artifact H2O2 and HMHP produced increased with decreasing trap temperature. Spiking ambient air with ethene or isoprene showed that these hydrocarbons, in the presence of ozone, can be responsible for the artifact production of peroxides. Our results clearly suggest that the peroxide data obtained by cryogenic sampling and reported in the literature should be interpreted with caution.

  12. Volatilization of iodine from nitric acid using peroxide

    DOEpatents

    Cathers, G.I.; Shipman, C.J.

    1975-10-21

    A method for removing radioactive iodine from nitric acid solution by adding hydrogen peroxide to the solution while concurrently holding the solution at the boiling point and distilling hydrogen iodide from the solution is reported.

  13. Atmospheric hydrogen peroxide and methyl hydroperoxide in Yanbian, China

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Ji, B.; Lee, M.; Kim, K.; Lee, G.

    2003-04-01

    Hydrogen peroxide and organic peroxides are photochemical byproducts. They are referred as the indicator of oxidizing capacity of the atmosphere. Further, they are related with the production and removal of ozone in photochemistry. To better understand the photochemical processes in the troposphere, it is essential to know the correct concentration of hydroperoxides. Hydrogen peroxide and methyl Hydroperoxide were measured from 24 Aug to 3 Sep in Yanbian, China. Measurements were made for continuously during the whole course of the experiments. After collected in aqueous solution using continuous scrubbing coil, hydroperoxides were separated by HPLC, and then quantified by fluorescence produced using postcolumn enzyme derivatization. Collection and analysis were done automatically Average concentration of hydrogen peroxide and methyl hydroperoxide were 0.9ppbc and 1.6 ppb, respectively. In general, hydroperoxides showed typical diurnal variations with the maximum concentration during day. It was the first study of air pollution conducted in Yanbian, China. Detailed results will be presented in the meeting.

  14. 49 CFR 172.552 - ORGANIC PEROXIDE placard.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., division number and inner border must be black; the symbol may be either black or white. (c) For... SECURITY PLANS Placarding § 172.552 ORGANIC PEROXIDE placard. (a) Except for size and color, the...

  15. Microbiologic evaluation of a hydrogen peroxide sterilization system.

    PubMed

    Wilkins, D L; Chung, P Y; Tsuchiya, P Y; Wessels, I F; Zuccarelli, A J

    1994-01-01

    The reliability of chemical sterilizers (acetone and/or 30-percent hydrogen peroxide at 25 degrees C and at 60 degrees C) was tested against Bacillus subtilis inoculated onto glass slides, commercial biological indicator discs (Bacillus stearothermophilus and B. subtilis), and B. subtilis spore survival. Acetone alone was not sporicidal. Hydrogen-peroxide-sterilized glass slides were sterile after 5 minutes. The indicator discs required 25 minutes at 25 degrees C, and less than 3 minutes at 60 degrees C (P < .0001). The D value of B. subtilis in 27-percent hydrogen peroxide at 25 degrees C is 2 minutes, with z values of 22 degrees C and 26 degrees C at 25 degrees C and 40 degrees C, respectively. For delicate instruments, a 30-percent peroxide solution followed by an acetone rinse provides an effective alternative to classic heat sterilization. PMID:7898862

  16. Dissolution of Spent Nuclear Fuel in Carbonate-Peroxide Solution

    SciTech Connect

    Soderquist, Chuck Z.; Hanson, Brady D.

    2010-01-31

    This study shows that spent UO2 fuel can be completely dissolved in a carbonate-peroxide solution apparently without attacking the metallic Mo-Tc-Ru-Rh-Pd fission product phase. Samples of spent nuclear fuel were pulverized and sieved to a uniform size, then duplicate aliquots were weighed into beakers for analysis. One set was dissolved in near-boiling 10M nitric acid, and the other set was dissolved in a solution of ammonium carbonate and hydrogen peroxide at room temperature. All the resulting fuel solutions were then analyzed for Sr-90, Tc-99, Cs-137, plutonium, and Am-241. For all the samples, the concentrations of Cs-137, Sr-90, plutonium, and Am-241 were the same for both the nitric acid dissolution and the ammonium carbonate-hydrogen peroxide dissolution, but the technetium concentration of the ammonium carbonate-hydrogen peroxide fuel solution was only about 25% of the same fuels dissolved in hot nitric acid.

  17. Semiempirical calculation of the peroxide bridge in glassy silicon dioxide

    SciTech Connect

    Sokolov, V.O.; Sulimov, V.B.

    1987-10-01

    The characteristics of a peroxide bridge are studied by the quantum-mechanical semiempirical method MPNDO/3 in the model of a molecular cluster. The geometry of the cluster was optimized for different distances between silicon atoms. The coordinates of the two oxygen atoms forming the peroxide bridge were employed as the optimization parameters. The minimum total energy of the cluster was sought. The scheme of single-electron levels was found. The effect of the peroxide bridge on the electronic structure of v-SiO/sub 2/ reduces to splitting of shallow levels from the edges of allowed bands, corresponding to strongly localized states. The energy of formation of a cluster in the presence of a peroxide bridge is close to the energy of formation of a cluster without defects.

  18. New cytotoxic cyclic peroxide acids from Plakortis sp. marine sponge

    PubMed Central

    Hoye, Thomas R.; Alarif, Walied M.; Basaif, Salim S.; Abo-Elkarm, Mohamed; Hamann, Mark T.; Wahba, Amir E.; Ayyad, Seif-Eldin N.

    2016-01-01

    Bioassay-guided fractionation of the extract of Jamaican marine sponge Plakortis sp. followed by preparative TLC and HPLC yielded several known methyl ester cyclic peroxides (1a, 2a, 3a, 4, 5), known plakortides (6,7), known bicyclic lactone (8) and new cyclic peroxide acids (1b, 2b, 3b). The chemical structures were elucidated by extensive interpretation of their spectroscopic data. These natural products showed remarkable in vitro cytotoxicity against several cancer cell lines. PMID:26835518

  19. Prediction and assignment of the FIR spectrum of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Helminger, P.; Messer, J. K.; De Lucia, F. C.; Bowman, W. C.

    1984-01-01

    Millimeter and submillimeter microwave studies are used to predict and assign the FIR rotational-torsional spectrum of hydrogen peroxide. Special attention is given to the strong Q-branch features that have recently been used by Traub and Chance to place an upper limit on the atmospheric abundance of hydrogen peroxide. In addition, 67 new transitions are reported in the 400-1000 GHz region.

  20. Therapies targeting lipid peroxidation in traumatic brain injury.

    PubMed

    Anthonymuthu, Tamil Selvan; Kenny, Elizabeth Megan; Bayır, Hülya

    2016-06-01

    Lipid peroxidation can be broadly defined as the process of inserting a hydroperoxy group into a lipid. Polyunsaturated fatty acids present in the phospholipids are often the targets for peroxidation. Phospholipids are indispensable for normal structure of membranes. The other important function of phospholipids stems from their role as a source of lipid mediators - oxygenated free fatty acids that are derived from lipid peroxidation. In the CNS, excessive accumulation of either oxidized phospholipids or oxygenated free fatty acids may be associated with damage occurring during acute brain injury and subsequent inflammatory responses. There is a growing body of evidence that lipid peroxidation occurs after severe traumatic brain injury in humans and correlates with the injury severity and mortality. Identification of the products and sources of lipid peroxidation and its enzymatic or non-enzymatic nature is essential for the design of mechanism-based therapies. Recent progress in mass spectrometry-based lipidomics/oxidative lipidomics offers remarkable opportunities for quantitative characterization of lipid peroxidation products, providing guidance for targeted development of specific therapeutic modalities. In this review, we critically evaluate previous attempts to use non-specific antioxidants as neuroprotectors and emphasize new approaches based on recent breakthroughs in understanding of enzymatic mechanisms of lipid peroxidation associated with specific death pathways, particularly apoptosis. We also emphasize the role of different phospholipases (calcium-dependent and -independent) in hydrolysis of peroxidized phospholipids and generation of pro- and anti-inflammatory lipid mediators. This article is part of a Special Issue entitled SI:Brain injury and recovery. PMID:26872597

  1. Sodium Borohydride/Hydrogen Peroxide Fuel Cells For Space Application

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Deelo, M. E.; Narayanan, S. R.

    2006-01-01

    This viewgraph presentation examines Sodium Borohydride and Hydrogen Peroxide Fuel Cells as they are applied to space applications. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Sodium Borohydride Fuel Cell Test Stands; 4) Fuel Cell Comparisons; 5) MEA Performance; 6) Anode Polarization; and 7) Electrode Analysis. The benefits of hydrogen peroxide as an oxidant and benefits of sodium borohydride as a fuel are also addressed.

  2. Microbial population index and community structure in saline-alkaline soil using gene targeted metagenomics.

    PubMed

    Keshri, Jitendra; Mishra, Avinash; Jha, Bhavanath

    2013-03-30

    Population indices of bacteria and archaea were investigated from saline-alkaline soil and a possible microbe-environment pattern was established using gene targeted metagenomics. Clone libraries were constructed using 16S rRNA and functional gene(s) involved in carbon fixation (cbbL), nitrogen fixation (nifH), ammonia oxidation (amoA) and sulfur metabolism (apsA). Molecular phylogeny revealed the dominance of Actinobacteria, Firmicutes and Proteobacteria along with archaeal members of Halobacteraceae. The library consisted of novel bacterial (20%) and archaeal (38%) genera showing ≤95% similarity to previously retrieved sequences. Phylogenetic analysis indicated ability of inhabitant to survive in stress condition. The 16S rRNA gene libraries contained novel gene sequences and were distantly homologous with cultured bacteria. Functional gene libraries were found unique and most of the clones were distantly related to Proteobacteria, while clones of nifH gene library also showed homology with Cyanobacteria and Firmicutes. Quantitative real-time PCR exhibited that bacterial abundance was two orders of magnitude higher than archaeal. The gene(s) quantification indicated the size of the functional guilds harboring relevant key genes. The study provides insights on microbial ecology and different metabolic interactions occurring in saline-alkaline soil, possessing phylogenetically diverse groups of bacteria and archaea, which may be explored further for gene cataloging and metabolic profiling. PMID:23083746

  3. Raising the acceptance of the AP2-line

    SciTech Connect

    Trbojevic, D.

    1989-04-05

    The 120 GeV Main Ring proton beam collides with the target at the end of the AP-1 line and creates antiprotons and other secondary particles. The AP-2 line transfers the negative particles from the target to the Debuncher. To provide a bigger antiproton stack size in the Accumulator, both the Debuncher as well as the AP-2 line acceptance have to be raised. This is a proposal for the improvement of the AP-2 line acceptance. The first part of the memo presents an acceptance examination of the existing AP-2 line by computer simulation, while the second presents a short proposal for aperture corrections. The computer program TURTLE was used to trace antiprotons through the AP-2 line without taking into account other negative charged particles. Betatron functions were obtained from the output of the SYNCH computer program. The SYNCH program was also used to check the dispersion match between the AP-2 line and the Debuncher. 3 refs., 6 figs., 5 tabs.

  4. Substrate and Transition State Binding in Alkaline Phosphatase Analyzed by Computation of Oxygen Isotope Effects.

    PubMed

    Roston, Daniel; Cui, Qiang

    2016-09-14

    Enzymes are powerful catalysts, and a thorough understanding of the sources of their catalytic power will facilitate many medical and industrial applications. Here we have studied the catalytic mechanism of alkaline phosphatase (AP), which is one of the most catalytically proficient enzymes known. We have used quantum mechanics calculations and hybrid quantum mechanics/molecular mechanics (QM/MM) simulations to model a variety of isotope effects relevant to the reaction of AP. We have calculated equilibrium isotope effects (EIEs), binding isotope effects (BIEs), and kinetic isotope effects (KIEs) for a range of phosphate mono- and diester substrates. The results agree well with experimental values, but the model for the reaction's transition state (TS) differs from the original interpretation of those experiments. Our model indicates that isotope effects on binding make important contributions to measured KIEs on V/K, which complicated interpretation of the measured values. Our results provide a detailed interpretation of the measured isotope effects and make predictions that can test the proposed model. The model indicates that the substrate is deformed in the ground state (GS) of the reaction and partially resembles the TS. The highly preorganized active site preferentially binds conformations that resemble the TS and not the GS, which induces the substrate to adapt to the enzyme, rather than the other way around-as with classic "induced fit" models. The preferential stabilization of the TS over the GS is what lowers the barrier to the chemical step. PMID:27541005

  5. Peroxide test strips detect added hydrogen peroxide in raw milk at levels affecting bacterial load.

    PubMed

    Martin, Nicole H; Friedlander, Adam; Mok, Allen; Kent, David; Wiedmann, Martin; Boor, Kathryn J

    2014-10-01

    Hydrogen peroxide (H2O2) has a long-established history of use as a preservative in milk worldwide. The use of H2O2 to activate the inherent lactoperoxidase enzyme system has dramatically improved the quality of raw dairy products in areas in which cooling is not widely available. In the United States, however, where refrigeration is widely available, the addition of H2O2 to milk is not permitted, with the exception of certain applications prior to cheesemaking and during the preparation of modified whey. Due to the relatively quick deterioration of H2O2 in fluid milk, the detection of raw milk adulterated with the compound can be challenging. In this study we evaluated (i) total aerobic bacterial counts and (ii) ability of peroxide test strips to detect H2O2 in raw milk with various concentrations (0, 100, 300, 500, 700, and 900 ppm) of added H2O2, incubated at both 6 and 21°C for 0, 24, and 48 h. Results showed that at both 6 and 21°C the H2O2 concentration and time had a significant effect on bacterial loads in raw milk. Additionally, commercially available test strips were able to detect H2O2 in raw milk, with predicted probability of >90%, immediately after addition and after 24 and 48 h for the higher concentrations used, offering a viable method for detecting raw milk adulteration with H2O2. PMID:25285503

  6. Effects of 10-Year Management Regimes on the Soil Seed Bank in Saline-Alkaline Grassland

    PubMed Central

    Ma, Hongyuan; Yang, Haoyu; Liang, Zhengwei; Ooi, Mark K. J.

    2015-01-01

    Background Management regimes for vegetation restoration of degraded grasslands can significantly affect the process of ecological succession. However, few studies have focused on variation in the soil seed bank during vegetation restoration under different management regimes, especially in saline-alkaline grassland habitats. Our aim was to provide insights into the ecological effects of grassland management regimes on soil seed bank composition and vegetation establishment in mown, fenced, transplanted and natural grassland sites, all dominated by the perennial rhizomatous grass Leymus chinensis. Methodology We studied species composition and diversity in both the soil seed bank and aboveground vegetation in differently managed grasslands in Northeast China. An NMDS (nonmetric multidimensional scaling) was used to evaluate the relationship between species composition, soil seed banks, aboveground vegetation and soil properties. Principal Findings Fenced and mown grassland sites had high density and species richness in both the soil seed bank and aboveground vegetation. The Transplanted treatment exhibited the highest vegetation growth and seed production of the target species L. chinensis. Seeds of L. chinensis in the soil occurred only in transplanted and natural grassland. Based on the NMDS analysis, the number of species in both the soil seed bank and aboveground vegetation were significantly related to soil Na+, Cl-, RSC (residual sodium carbonate), alkalinity, ESP (exchangeable sodium percentage) and AP (available phosphorus). Conclusions Soil seed bank composition and diversity in the saline-alkaline grassland were significantly affected by the management regimes implemented, and were also significantly related to the aboveground vegetation and several soil properties. Based on vegetative growth, reproductive output and maintenance of soil seed bank, the transplanting was identified as the most effective method for relatively rapid restoration of the target

  7. Atmospheric hydrogen peroxide and Eoarchean iron formations.

    PubMed

    Pecoits, E; Smith, M L; Catling, D C; Philippot, P; Kappler, A; Konhauser, K O

    2015-01-01

    It is widely accepted that photosynthetic bacteria played a crucial role in Fe(II) oxidation and the precipitation of iron formations (IF) during the Late Archean-Early Paleoproterozoic (2.7-2.4 Ga). It is less clear whether microbes similarly caused the deposition of the oldest IF at ca. 3.8 Ga, which would imply photosynthesis having already evolved by that time. Abiological alternatives, such as the direct oxidation of dissolved Fe(II) by ultraviolet radiation may have occurred, but its importance has been discounted in environments where the injection of high concentrations of dissolved iron directly into the photic zone led to chemical precipitation reactions that overwhelmed photooxidation rates. However, an outstanding possibility remains with respect to photochemical reactions occurring in the atmosphere that might generate hydrogen peroxide (H2 O2 ), a recognized strong oxidant for ferrous iron. Here, we modeled the amount of H2 O2 that could be produced in an Eoarchean atmosphere using updated solar fluxes and plausible CO2 , O2 , and CH4 mixing ratios. Irrespective of the atmospheric simulations, the upper limit of H2 O2 rainout was calculated to be <10(6) molecules cm(-2) s(-1) . Using conservative Fe(III) sedimentation rates predicted for submarine hydrothermal settings in the Eoarchean, we demonstrate that the flux of H2 O2 was insufficient by several orders of magnitude to account for IF deposition (requiring ~10(11) H2 O2 molecules cm(-2) s(-1) ). This finding further constrains the plausible Fe(II) oxidation mechanisms in Eoarchean seawater, leaving, in our opinion, anoxygenic phototrophic Fe(II)-oxidizing micro-organisms the most likely mechanism responsible for Earth's oldest IF. PMID:25324177

  8. Recent Development in Hydrogen Peroxide Pumped Propulsion

    SciTech Connect

    Ledebuhr, A G; Antelman, D R; Dobie, D W; Gorman, T S; Jones, M S; Kordas, J F; McMahon, D H; Ng, L C; Nielsen, D P; Ormsby, A E; Pittenger, L C; Robinson, J A; Skulina, K M; Taylor, W G; Urone, D A; Wilson, B A

    2004-03-22

    This paper describes the development of a lightweight high performance pump-fed divert and attitude control system (DACS). Increased kinetic Kill Vehicles (KV) capabilities (higher .v and acceleration capability) will especially be needed for boost phase engagements where a lower mass KV DACS enables smaller overall interceptors. To increase KV performance while reducing the total DACS dry mass (<10 kg), requires a design approach that more closely emulates those found in large launch vehicles, where pump-fed propulsion enables high propellant-mass-fraction systems. Miniaturized reciprocating pumps, on a scale compatible with KV applications, offer the potential of a lightweight DACS with both high {Delta}v and acceleration capability, while still enabling the rapid pulsing of the divert thrusters needed in the end-game fly-in. Pumped propulsion uses lightweight low-pressure propellant tanks, as the main vehicle structure and eliminates the need for high-pressure gas bottles, reducing mass and increasing the relative propellant load. Prior work used hydrazine and demonstrated a propellant mass fraction >0.8 and a vehicle propulsion dry mass of {approx}3 kg. Our current approach uses the non-toxic propellants 90% hydrogen peroxide and kerosene. This approach enables faster development at lower costs due to the ease of handling. In operational systems these non-toxic propellants can simplify the logistics for manned environments including shipboard applications. This DACS design configuration is expected to achieve sufficient mass flows to support divert thrusters in the 1200 N to 1330 N (270 lbf to 300 lbf) range. The DACS design incorporates two pairs of reciprocating differential piston pumps (oxidizer and fuel), a warm-gas drive system, compatible bi-propellant thrusters, lightweight valves, and lightweight low-pressure propellant tanks. This paper summarizes the current development status and plans.

  9. Hydrogen Peroxide in Groundwater at Rifle, Colorado

    NASA Astrophysics Data System (ADS)

    Yuan, X.; Nico, P. S.; Williams, K. H.; Hobson, C.; Davis, J. A.

    2015-12-01

    Hydrogen peroxide (H2O2), as a reactive transient presenting ubiquitously in natural surface waters, can react with a large suite of biologically important and redox-sensitive trace elements. The dominant source of H2O2 in natural waters has long been thought to be photo-oxidation of chromophoric dissolved organic matter by molecular oxygen to produce superoxide radical, which then proceeds via dismutation to generate H2O2. However, recent studies have indicated that dark production of H2O2 in deep seawater, principally by biological production, is potentially on par with photochemical generation. Here, we present evidence for abiotic dark generation of H2O2 in groundwater in an alluvial aquifer adjacent to the Colorado River near Rifle, CO. Background H2O2 concentrations were determined in situ using a sensitive chemiluminescence-based method. Our results suggest H2O2 concentrations ranged from lower than the detection limit (1 nM) to 54 nM in different monitoring wells at the site, and the concentrations exhibited close correlations with profiles of dissolved oxygen and iron concentrations in the wells, indicating a possible metal redox cycling mechanism. In addition, dissolved natural organic matter, which could potentially coordinate the interconversion of ferric and ferrous species, might also play an important role in H2O2 formation. While biologically mediated activities have been recognized as the major sink of H2O2, the detected H2O2 pattern in groundwater suggests the existence of a balance between H2O2 source and decay, which potentially involves a cascade of biogeochemically significant processes, including the interconversion of ferrous/ferric species, the generation of more reactive oxygen species, such as hydroxyl radical, the depletion of dissolved oxygen and further transformation of natural organic matter and other chemical pollutants.

  10. Localised hydrogen peroxide sensing for reproductive health

    NASA Astrophysics Data System (ADS)

    Purdey, Malcolm S.; Schartner, Erik P.; Sutton-McDowall, Melanie L.; Ritter, Lesley J.; Thompson, Jeremy G.; Monro, Tanya M.; Abell, Andrew D.

    2015-05-01

    The production of reactive oxygen species (ROS) is known to affect the developmental competence of embryos. Hydrogen peroxide (H2O2) an important reactive oxygen species, is also known to causes DNA damage and defective sperm function. Current techniques require incubating a developing embryo with an organic fluorophore which is potentially hazardous for the embryo. What we need is a localised ROS sensor which does not require fluorophores in solution and hence will allow continuous monitoring of H2O2 production without adversely affect the development of the embryo. Here we report studies on such a fibre-based sensor for the detection of H2O2 that uses a surface-bound aryl boronate fluorophore carboxyperoxyfluor-1(CPF1). Optical fibres present a unique platform due to desirable characteristics as dip sensors in biological solutions. Attempts to functionalise the fibre tips using polyelectrolyte layers and (3-aminopropyl)triethoxysilane (APTES) coatings resulted in a limited signal and poor fluorescent response to H2O2 due to a low tip surface density of the fluorophore. To increase the surface density, CPF1 was integrated into a polymer matrix formed on the fibre tip by a UV-catalysed polymerisation process of acrylamide onto a methacrylate silane layer. The polyacrylamide containing CPF1 gave a much higher surface density than previous surface attachment methods and the sensor was found to effectively detect H2O2. Using this method, biologically relevant concentrations of H2O2 were detected, enabling remote sensing studies into ROS releases from embryos throughout early development.

  11. Single domain antibody-alkaline phosphatase fusion proteins for antigen detection--analysis of affinity and thermal stability of single domain antibody.

    PubMed

    Liu, Jinny L; Zabetakis, Dan; Lee, Audrey Brozozog; Goldman, Ellen R; Anderson, George P

    2013-07-31

    Single domain antibody (sdAb)-alkaline phosphatase (AP) fusion proteins have been demonstrated to be useful immunodiagnostic reagents for bio-threat agent detection. The bivalent nature of sdAb-AP fusion proteins significantly increases effective affinity and thus the sensitivity of detection, but the thermal stability of the fusion protein had not been explored. This property is critical for the development of immunoassays for use in austere environments. In this study four sdAbs with specificity for MS2 phage coat protein (CP) were expressed as fusions with AP in order to evaluate the thermal stability and affinity of the resulting constructs. The melting temperature (Tm) of the sdAb and sdAb-AP fusion proteins was measured by a combination of Circular Dichroism (CD), differential scanning calorimetry (DSC) and Fluorescence-based Thermal Shift assay. Binding kinetics were assessed using surface plasmon resonance (SPR). Our results indicated that the AP fusion protein did not increase the Tm or enhance thermal stability of the sdAb, but did provide the expected increase in binding affinity as compared to the original sdAb. PMID:23570946

  12. Development of a nanobody-alkaline phosphatase fusion protein and its application in a highly sensitive direct competitive fluorescence enzyme immunoassay for detection of ochratoxin A in cereal

    PubMed Central

    Liu, Xing; Xu, Yang; Wan, De-bin; Xiong, Yong-hua; He, Zhen-yun; Wang, Xian-xian; Gee, Shirley J.; Ryu, Dojin; Hammock, Bruce D.

    2015-01-01

    A rapid and sensitive direct competitive fluorescence enzyme immunoassay (dc-FEIA) for ochratoxin A (OTA) based on a nanobody (Nb)-alkaline phosphatase (AP) fusion protein was developed. The VHH gene of Nb28 was subcloned into the expression vector pecan45 containing the AP double mutant gene. The Nb28-AP construct was transformed into E. coli BL21(DE3)plysS and soluble expression in bacteria was confirmed by SDS-PAGE and Western blot. Both the Nb properties and AP enzymatic activity were validated by colorimetric and fluorometric analysis. The 50% inhibitory concentration and the detection limit of the dc-FEIA were 0.13 ng/mL and 0.04 ng/mL, respectively, with a linear range of 0.06–0.43 ng/mL. This assay was compared with LC-MS/MS, and the results indicated the reliability of Nb-AP fusion protein-based dc-FEIA for monitoring OTA contamination in cereal. PMID:25531426

  13. Development of Emergency Response Guidelines (ERGs) for AP1000

    SciTech Connect

    Yuichi Hayashi; Saiu, Gianfranco; Wright, Richard F.

    2006-07-01

    The AP1000 is two-loop 1100 MWe advanced pressurized water reactor (PWR) that uses passive safety features to enhance plant safety and to provide significant and measurable improvements in plant simplification, reliability, investment protection and plant costs. The AP1000 uses proven technology, which builds on over 30 years of operating PWR experience. The AP1000 final design certification has been approved by the NRC in December, 2005. The Emergency Response Guidelines (ERGs) have been developed for the AP1000. The generic ERGs for the low pressure reference PWR plant were used as the basic documents to develop the AP1000 ERGs. The AP1000 design differences from the reference plant were reviewed and reflected in the process of developing operational steps in each ERG. The AP1000 used PRA in both design and licensing. The provisions of the AP1000 PRA were also reviewed and incorporated into the ERGs Although the AP1000 design does not require operator actions for the first 72 hours after accidents, the operator actions with both safety-related and non-safety-related equipment have an important role to mitigate the consequence of accidents. In the event of a LOCA, the AP1000 safety-related passive core cooling system (PXS) provides sources of core makeup water along with an automatic depressurization system (ADS) consisting of several sets of redundant flow paths which are sequentially opened in stages to reduce the reactor coolant system (RCS) pressure in a controlled manner. The final stage of this system, ADS-4, consists of four large valves that open off the hot legs, reducing the pressure to allow gravity injection from the in-containment refueling water storage tank (IRWST) and eventually the containment sump recirculation. The AP1000 has non-safety-related normal residual heat removal system (RNS) pumps which can be used to provide low pressure pumped injection of cask loading pit and/or IRWST water and recirculation of containment water. These pumps are

  14. A new gap separation mechanism for APS insertion devices.

    SciTech Connect

    Trakhtenberg, E. M.; Tcheskidov, V.; Den Hartog, P. K.; Deriy, B.; Erdmann, M.; Makarov, O.; Moog, E. R.

    1999-10-25

    A new gap separation mechanism for use with the standard Advanced Photon Source (APS) 3.3-cm-period undulator magnetic structures has been designed and built and the first system has been installed in the APS storage ring. The system allows a minimum magnetic gap of 10 mm for use with the APS 8-mm insertion device vacuum chambers. The mechanism is a bolted steel frame structure with a simple 4-motor mechanical drive train. The control system uses servomotors with incremental rotary encoders and virtual absolute linear encoders.

  15. AP600 design certification thermal hydraulics testing and analysis

    SciTech Connect

    Hochreiter, L.E.; Piplica, E.J.

    1995-09-01

    Westinghouse Electric Corporation, in conjunction with the Department of Energy and the Electric Power Research Institute, have been developing an advanced light water reactor design; the AP600. The AP600 is a 1940 Mwt, 600Mwe unit which is similar to a Westinghouse two-loop Pressurized Water Reactor. The accumulated knowledge on reactor design to reduce the capital costs, construction time, and the operational and maintenance cost of the unit once it begins to generate electrical power. The AP600 design goal is to maintain an overall cost advantage over fossil generated electrical power.

  16. Human Immunodeficiency Virus Type 2 (HIV-2) Gag Is Trafficked in an AP-3 and AP-5 Dependent Manner

    PubMed Central

    Alford, Justine E.; Marongiu, Michela; Watkins, Gemma L.

    2016-01-01

    Although human immunodeficiency virus (HIV) types 1 and 2 are closely related lentiviruses with similar replication cycles, HIV-2 infection is associated with slower progression to AIDS, a higher proportion of long term non-progressors, and lower rates of transmission than HIV-1, likely as a consequence of a lower viral load during HIV-2 infection. A mechanistic explanation for the differential viral load remains unclear but knowledge of differences in particle production between HIV-1 and HIV-2 may help to shed light on this issue. In contrast to HIV-1, little is known about the assembly of HIV-2 particles, and the trafficking of HIV-2 Gag, the structural component of the virus, within cells. We have established that HIV-2 Gag accumulates in intracellular CD63 positive compartments, from which it may be delivered or recycled to the cell surface, or degraded. HIV-2 particle release was dependent on the adaptor protein complex AP-3 and the newly identified AP-5 complex, but much less so on AP-1. In contrast, HIV-1 particle release required AP-1 and AP-3, but not AP-5. AP-2, an essential component of clathrin-mediated endocytosis, which was previously shown to be inhibitory to HIV-1 particle release, had no effect on HIV-2. The differential requirement for adaptor protein complexes confirmed that HIV-1 and HIV-2 Gag have distinct cellular trafficking pathways, and that HIV-2 particles may be more susceptible to degradation prior to release. PMID:27392064

  17. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    SciTech Connect

    Delegard, C.H.; Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K.

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes.

  18. Differential recognition of a dileucine-based sorting signal by AP-1 and AP-3 reveals a requirement for both BLOC-1 and AP-3 in delivery of OCA2 to melanosomes

    PubMed Central

    Sitaram, Anand; Dennis, Megan K.; Chaudhuri, Rittik; De Jesus-Rojas, Wilfredo; Tenza, Danièle; Setty, Subba Rao Gangi; Wood, Christopher S.; Sviderskaya, Elena V.; Bennett, Dorothy C.; Raposo, Graça; Bonifacino, Juan S.; Marks, Michael S.

    2012-01-01

    Cell types that generate unique lysosome-related organelles (LROs), such as melanosomes in melanocytes, populate nascent LROs with cargoes that are diverted from endosomes. Cargo sorting toward melanosomes correlates with binding via cytoplasmically exposed sorting signals to either heterotetrameric adaptor AP-1 or AP-3. Some cargoes bind both adaptors, but the relative contribution of each adaptor to cargo recognition and their functional interactions with other effectors during transport to melanosomes are not clear. Here we exploit targeted mutagenesis of the acidic dileucine–based sorting signal in the pigment cell–specific protein OCA2 to dissect the relative roles of AP-1 and AP-3 in transport to melanosomes. We show that binding to AP-1 or AP-3 depends on the primary sequence of the signal and not its position within the cytoplasmic domain. Mutants that preferentially bound either AP-1 or AP-3 each trafficked toward melanosomes and functionally complemented OCA2 deficiency, but AP-3 binding was necessary for steady-state melanosome localization. Unlike tyrosinase, which also engages AP-3 for optimal melanosomal delivery, both AP-1– and AP-3–favoring OCA2 variants required BLOC-1 for melanosomal transport. These data provide evidence for distinct roles of AP-1 and AP-3 in OCA2 transport to melanosomes and indicate that BLOC-1 can cooperate with either adaptor during cargo sorting to LROs. PMID:22718909

  19. Preparation of Ag nanoparticle-decorated poly(m-phenylenediamine) microparticles and their application for hydrogen peroxide detection.

    PubMed

    Tian, Jingqi; Li, Hailong; Lu, Wenbo; Luo, Yonglan; Wang, Lei; Sun, Xuping

    2011-05-01

    The chemical oxidation polymerization of m-phenylenediamine (MPD) by ammonium persulfate (APS) at room temperature results in the formation of poly(m-phenylenediamine) (PMPD) microparticles. The subsequent treatment of such microparticles with an aqueous AgNO(3) solution produces Ag nanoparticle (AgNP)-decorated PMPD microparticles. It was found that as-formed AgNPs exhibited remarkable catalytic performance toward the reduction of hydrogen peroxide (H(2)O(2)). The enzymeless H(2)O(2) sensor constructed with such composites showed a fast amperometric response time of less than 5 s, and the corresponding linear range and detection limit were estimated to be from 0.1 to 30 mM and 4.7 µM, respectively, at a signal-to-noise ratio of 3. PMID:21387026

  20. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    SciTech Connect

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  1. Autonomous in situ measurements of seawater alkalinity.

    PubMed

    Spaulding, Reggie S; DeGrandpre, Michael D; Beck, James C; Hart, Robert D; Peterson, Brittany; De Carlo, Eric H; Drupp, Patrick S; Hammar, Terry R

    2014-08-19

    Total alkalinity (AT) is an important parameter for describing the marine inorganic carbon system and understanding the effects of atmospheric CO2 on the oceans. Measurements of AT are limited, however, because of the laborious process of collecting and analyzing samples. In this work we evaluate the performance of an autonomous instrument for high temporal resolution measurements of seawater AT. The Submersible Autonomous Moored Instrument for alkalinity (SAMI-alk) uses a novel tracer monitored titration method where a colorimetric pH indicator quantifies both pH and relative volumes of sample and titrant, circumventing the need for gravimetric or volumetric measurements. The SAMI-alk performance was validated in the laboratory and in situ during two field studies. Overall in situ accuracy was -2.2 ± 13.1 μmol kg(-1) (n = 86), on the basis of comparison to discrete samples. Precision on duplicate analyses of a carbonate standard was ±4.7 μmol kg(-1) (n = 22). This prototype instrument can measure in situ AT hourly for one month, limited by consumption of reagent and standard solutions. PMID:25051401

  2. Solubility of uranium in alkaline salt solutions

    SciTech Connect

    Hobbs, D.T.; Edwards, T.B.

    1994-03-29

    The solubility of uranium in alkaline salt solutions was investigated to screen for significant factors and interactions among the major salt components and temperature. The components included in the study were the sodium salts of hydroxide, nitrate, nitrite, aluminate, sulfate, and carbonate. General findings from the study included: (1) uranium solubilities are very low (1-20 mg/L) for all solution compositions at hydroxide concentrations from 0.1 to 17 molar (2) carbonate, sulfate, and aluminate are not effective complexants for uranium at high hydroxide concentration, (3) uranium solubility decreases with increasing temperature for most alkaline salt solutions, and (4) uranium solubility increases with changes in solution chemistry that reflect aging of high level waste (increase in nitrite and carbonate concentrations, decrease in nitrate and hydroxide concentrations). A predictive model for the concentration of uranium as a function of component concentrations and temperature was fitted to the data. All of the solution components and temperature were found to be significant. There is a significant lack of fit for the model, which suggests that the dependence on the uranium solubility over the wide range of solution compositions is non-linear and/or that there are other uncontrolled parameters which are important to the uranium solubility.

  3. Molecular modeling of human alkaline sphingomyelinase.

    PubMed

    Suresh, Panneer Selvam; Olubiyi, Olujide; Thirunavukkarasu, Chinnasamy; Strodel, Birgit; Kumar, Muthuvel Suresh

    2011-01-01

    Alkaline sphingomyelinase, which is expressed in the human intestine and hydrolyses sphingomyelin, is a component of the plasma and the lysosomal membranes. Hydrolase of sphingomyelin generates ceramide, sphingosine, and sphingosine 1-phosphate that have regulatory effects on vital cellular functions such as proliferation, differentiation, and apoptosis. The enzyme belongs to the Nucleotide Pyrophosphatase/Phosphodiesterase family and it differs in structural similarity with acidic and neutral sphingomyelinase. In the present study we modeled alkaline sphingomyelinase using homology modeling based on the structure of Nucleotide Pyrophosphatase/Phosphodiesterase from Xanthomonas axonopodis with which it shares 34% identity. Homology modeling was performed using Modeller9v7. We found that Cys78 and Cys394 form a disulphide bond. Further analysis shows that Ser76 may be important for the function of this enzyme, which is supported by the findings of Wu et al. (2005), that S76F abolishes the activity completely. We found that the residues bound to Zn(2+) are conserved and geometrically similar with the template. Molecular Dynamics simulations were carried out for the modeled protein to observe the effect of Zinc metal ions. It was observed that the metal ion has little effect with regard to the stability but induces increased fluctuations in the protein. These analyses showed that Zinc ions play an important role in stabilizing the secondary structure and in maintaining the compactness of the active site. PMID:21544170

  4. Bone alkaline phosphatase in rheumatic diseases.

    PubMed

    Beyeler, C; Banks, R E; Thompson, D; Forbes, M A; Cooper, E H; Bird, H

    1995-07-01

    A double monoclonal immunoradiometric assay specific for bone alkaline phosphatase (BAP) was used to determine whether the raised total alkaline phosphatase (TAP) often found in patients with active rheumatoid arthritis (RA) and ankylosing spondylitis (AS) is derived from bone or liver. Fifty-eight patients with RA were compared to 14 with AS and 14 with non-inflammatory rheumatic diseases (NI). None had clinical liver disease and only one had a slightly elevated aspartate transaminase activity. Elevated BAP concentrations were found in seven patients (5 RA, 1 AS, 1 NI), only two of whom also had abnormal TAP. Abnormal TAP activities were found in only three patients (all RA). BAP did not correlate with disease activity in RA or AS. In contrast, TAP correlated with disease activity (assessed by plasma viscosity) in RA (P < 0.002) and gamma-glutamyl transferase (GGT) also correlated with plasma viscosity in RA (P < 0.01). Both TAP and BAP were significantly correlated with GGT in RA (P < 0.001 and P < 0.02, respectively). These findings are discussed, together with possible reasons for the conflicting nature of some of the observations. PMID:7486797

  5. Advanced inorganic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (Inventor)

    1982-01-01

    A flexible, porous battery separator comprising a coating applied to a porous, flexible substrate is described. The coating comprises: (1) a thermoplastic rubber-based resin which is insoluble and unreactive in the alkaline electrolyte; (2) a polar organic plasticizer which is reactive with the alkaline electrolyte to produce a reaction product which contains a hydroxyl group and/or a carboxylic acid group; and (3) a mixture of polar particulate filler materials which are unreactive with the electrolyte, the mixture comprising at least one first filler material having a surface area of greater than 25 meters sq/gram, at least one second filler material having a surface area of 10 to 25 sq meters/gram, wherein the volume of the mixture of filler materials is less than 45% of the total volume of the fillers and the binder, the filler surface area per gram of binder is about 20 to 60 sq meters/gram, and the amount of plasticizer is sufficient to coat each filler particle. A method of forming the battery separator is also described.

  6. SELECTIVE SEPARATION OF URANIUM FROM THORIUM, PROTACTINIUM AND FISSION PRODUCTS BY PEROXIDE DISSOLUTION METHOD

    DOEpatents

    Seaborg, G.T.; Gofman, J.W.; Stoughton, R.W.

    1959-08-18

    A method is described for separating U/sup 233/ from thorium and fission products. The separation is effected by forming a thorium-nitric acid solution of about 3 pH, adding hydrogen peroxide to precipitate uranium and thorium peroxide, treating the peroxides with sodium hydroxide to selectively precipitate the uranium peroxide, and reacting the separated solution with nitric acid to re- precipitate the uranium peroxide.

  7. QCD on the Massively Parallel Computer AP1000

    NASA Astrophysics Data System (ADS)

    Akemi, K.; Fujisaki, M.; Okuda, M.; Tago, Y.; Hashimoto, T.; Hioki, S.; Miyamura, O.; Takaishi, T.; Nakamura, A.; de Forcrand, Ph.; Hege, C.; Stamatescu, I. O.

    We present the QCD-TARO program of calculations which uses the parallel computer AP1000 of Fujitsu. We discuss the results on scaling, correlation times and hadronic spectrum, some aspects of the implementation and the future prospects.

  8. Engaging Cuban Physicists Through the APS/CPS Partnership

    NASA Astrophysics Data System (ADS)

    Lerch, Irving A.; Lerch, Irving A.

    In his reflections on Cuban physics, Marcelo Alonso urges APS to take steps to promote interactions between Cuban and US physicists. As an introduction to Marcello's essay, this note will summarize past and current activities.

  9. An improved model for the combustion of AP composite propellants

    NASA Technical Reports Server (NTRS)

    Cohen, N. S.; Strand, L. D.

    1981-01-01

    This paper presents several improvements to the BDP model of steady-state burning of AP composite solid propellants. The Price-Boggs-Derr model of AP monopropellant burning is incorporated to represent the AP. A separate energy equation is written for the binder to permit a different surface temperature from the AP; this includes an analysis of the sharing of primary diffusion flame energy, and correction of a BDP model inconsistency in treating the binder regression rate. A method for assembling component contributions to calculate the burning rates of multimodal propellants is also presented. Results are shown in the form of representative burning rate curves, comparisons with data, and calculated internal details of interest. Ideas for future work are discussed in an Appendix.

  10. A hot-spare injector for the APS linac.

    SciTech Connect

    Lewellen, J. W.

    1999-04-13

    Last year a second-generation SSRL-type thermionic cathode rf gun was installed in the Advanced Photon Source (APS) linac. This gun (referred to as ''gun2'') has been successfully commissioned and now serves as the main injector for the APS linac, essentially replacing the Koontz-type DC gun. To help ensure injector availability, particularly with the advent of top-up mode operation at the APS, a second thermionic-cathode rf gun will be installed in the APS linac to act as a hot-spare beam source. The hot-spare installation includes several unique design features, including a deep-orbit Panofsky-style alpha magnet. Details of the hot-spare beamline design and projected performance are presented, along with some plans for future performance upgrades.

  11. Rechargeable Zn-MnO sub 2 alkaline batteries

    SciTech Connect

    Wruck, W.J.; Reichman, B.; Bullock, K.R.; Kao, W.H. )

    1991-12-01

    In this paper progress in the development of rechargeable alkaline zinc-manganese dioxide cells is described. The advantages and limitations of the system are evaluated. Laboratory tests run on commercial primary alkaline cells as well as model simulations of a bipolar MnO{sub 2} electrode show that the rechargeable alkaline battery may be able to compete with lead-acid, nickel-cadmium, and secondary lithium cells for low- to moderate-rate applications. However, because of this poor performance at high rates and low temperatures, the alkaline MnO{sub 2} battery is not suitable for present automotive starting applications.

  12. The AP-3 adaptor complex mediates sorting of yeast and mammalian PQ-loop-family basic amino acid transporters to the vacuolar/lysosomal membrane

    PubMed Central

    Llinares, Elisa; Barry, Abdoulaye Oury; André, Bruno

    2015-01-01

    The limiting membrane of lysosomes in animal cells and that of the vacuole in yeast include a wide variety of transporters, but little is known about how these proteins reach their destination membrane. The mammalian PQLC2 protein catalyzes efflux of basic amino acids from the lysosome, and the similar Ypq1, −2, and −3 proteins of yeast perform an equivalent function at the vacuole. We here show that the Ypq proteins are delivered to the vacuolar membrane via the alkaline phosphatase (ALP) trafficking pathway, which requires the AP-3 adaptor complex. When traffic via this pathway is deficient, the Ypq proteins pass through endosomes from where Ypq1 and Ypq2 properly reach the vacuolar membrane whereas Ypq3 is missorted to the vacuolar lumen via the multivesicular body pathway. When produced in yeast, PQLC2 also reaches the vacuolar membrane via the ALP pathway, but tends to sort to the vacuolar lumen if AP-3 is defective. Finally, in HeLa cells, inhibiting the synthesis of an AP-3 subunit also impairs sorting of PQLC2 to lysosomes. Our results suggest the existence of a conserved AP-3-dependent trafficking pathway for proper delivery of basic amino acid exporters to the yeast vacuole and to lysosomes of human cells. PMID:26577948

  13. Divisions Iv-V / Working Group ap & Related Stars

    NASA Astrophysics Data System (ADS)

    Mathys, Gautier; Cunha, Margarida; Dworetsky, Michael; Kochukhov, Oleg; Kupka, Friedrich; LeBlanc, Francis; Monier, Richard; Paunzen, Ernst; Pintado, Olga; Piskunov, Nikolai; Ziznovsky, Jozef

    2012-04-01

    The purpose of the Working Group on Ap and Related Stars (ApWG) is to promote and facilitate research about stars in the spectral type range from B to early F that exhibit surface chemical peculiarities and related phenomena. This is a very active field of research, in which a wide variety of new developments have taken place since 2009, as illustrated by the following selected highlights.

  14. In vitro and in vivo evaluation of SLA titanium surfaces with further alkali or hydrogen peroxide and heat treatment.

    PubMed

    Zhang, E W; Wang, Y B; Shuai, K G; Gao, F; Bai, Y J; Cheng, Y; Xiong, X L; Zheng, Y F; Wei, S C

    2011-04-01

    The present study aimed to evaluate the bioactivity of titanium surfaces sandblasted with large-grit corundum and acid etched (SLA) plus further alkali or hydrogen peroxide and heat treatment for dental implant application. Pure titanium disks were mechanically polished as control surface (Ti-control) and then sandblasted with large-grit corundum and acid etched (SLA). Further chemical modifications were conducted using alkali and heat treatment (ASLA) and hydrogen peroxide and heat treatment (HSLA) alternatively. The surface properties were characterized by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and contact angle and roughness measurements. Further evaluation of surface bioactivity was conducted by MC3T3-E1 cell attachment, proliferation, morphology, alkaline phosphatase (ALP) activity and calcium deposition on the sample surfaces. After insertion in the beagle's mandibula for a specific period, cylindrical implant samples underwent micro-CT examination and then histological examination. It was found that ASLA and HSLA surfaces significantly increased the surface wettability and MC3T3-E1 cell attachment percentage, ALP activity and the quality of calcium deposition in comparison with simple SLA and Ti-control surfaces. Animal studies showed good osseointegration of ASLA and HSLA surfaces with host bone. In conclusion, ASLA and HSLA surfaces enhanced the bioactivity of the traditional SLA surface by integrating the advantages of surface topography, composition and wettability. PMID:21293055

  15. Protective effects of ginger toward cadmium-induced testes and kidney lipid peroxidation and hematological impairment in albino rats.

    PubMed

    Onwuka, Frank C; Erhabor, Osaro; Eteng, M U; Umoh, I B

    2011-01-01

    This study was carried out to investigate the effect of oral dietary supplementation with ginger on cadmium-induced toxic effects on biochemical, hematological, and pathophysiological indices of albino rats. The effect of cadmium and cadmium/ginger treatment on lipid peroxidation was measured by malondialdehyde (MDA) levels in testes and kidney; serum activities of alkaline phosphatase (ALP), acid phosphatase (ACP), and prostatic acid phosphatase (PAP) enzyme were investigated alongside hematological indices. The results showed that cadmium induces a significant increase in both testicular and kidney MDA, whereas cadmium/ginger treatment produced a significant reversal of the effect of lipid peroxidation (P=.004). Cadmium treatment induced 75%, 78%, and 22% increases in activities of ACP, PAP, and ALP, respectively, whereas the cadmium/ginger-treated group reversed these values for enzyme activities (P=.001). Results of organ weight and hematological indices analysis in the cadmium-treated rats showed a decrease in organ weight and distortion of the hemopoietic features, whereas the cadmium/ginger-treated rats showed an improvement in organ weight and hematological indices (P=.04 and .001, respectively). The reversal of the toxic effects of cadmium in the cadmium/ginger-treated albino rats heralds the antioxidant potency of ginger toward cadmium toxicity-associated oxidative stress. PMID:21476888

  16. Different Modes of Hydrogen Peroxide Action During Seed Germination

    PubMed Central

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging. PMID:26870076

  17. The Amoebicidal Effect of Ergosterol Peroxide Isolated from Pleurotus ostreatus.

    PubMed

    Meza-Menchaca, Thuluz; Suárez-Medellín, Jorge; Del Ángel-Piña, Christian; Trigos, Ángel

    2015-12-01

    Dysentery is an inflammation of the intestine caused by the protozoan parasite Entamoeba histolytica and is a recurrent health problem affecting millions of people worldwide. Because of the magnitude of this disease, finding novel strategies for treatment that does not affect human cells is necessary. Ergosterol peroxide is a sterol particularly known as a major cytotoxic agent with a wide spectrum of biological activities produced by edible and medicinal mushrooms. The aim of this report is to evaluate the amoebicidal activity of ergosterol peroxide (5α, 8α-epidioxy-22E-ergosta-6,22-dien-3β-ol isolated from 5α, 8α-epidioxy-22E-ergosta-6,22-dien-3β-ol) (Jacq.) P. Kumm. f. sp. Florida. Our results show that ergosterol peroxide produced a strong cytotoxic effect against amoebic growth. The inhibitory concentration IC50 of ergosterol peroxide was evaluated. The interaction between E. histolytica and ergosterol peroxide in vitro resulted in strong amoebicidal activity (IC50  = 4.23 nM) that may be due to the oxidatory effect on the parasitic membrane. We also tested selective toxicity of ergosterol peroxide using a cell line CCL-241, a human epithelial cell line isolated from normal human fetal intestinal tissue. To the best of our knowledge, this is the first report on the cytotoxicity of ergosterol peroxide against E. histolytica, which uncovers a new biological property of the lipidic compound isolated from Pleurotus ostreatus (Jacq.) P. Kumm. f. sp. Florida. PMID:26392373

  18. Effect of alkaline addition on anaerobic sludge digestion with combined pretreatment of alkaline and high pressure homogenization.

    PubMed

    Fang, Wei; Zhang, Panyue; Zhang, Guangming; Jin, Shuguang; Li, Dongyi; Zhang, Meixia; Xu, Xiangzhe

    2014-09-01

    To improve anaerobic digestion efficiency, combination pretreatment of alkaline and high pressure homogenization was applied to pretreat sewage sludge. Effect of alkaline dosage on anaerobic sludge digestion was investigated in detail. SCOD of sludge supernatant significantly increased with the alkaline dosage increase after the combined pretreatment because of sludge disintegration. Organics were significantly degraded after the anaerobic digestion, and the maximal SCOD, TCOD and VS removal was 73.5%, 61.3% and 43.5%, respectively. Cumulative biogas production, methane content in biogas and biogas production rate obviously increased with the alkaline dosage increase. Considering both the biogas production and alkaline dosage, the optimal alkaline dosage was selected as 0.04 mol/L. Relationships between biogas production and sludge disintegration showed that the accumulative biogas was mainly enhanced by the sludge disintegration. The methane yield linearly increased with the DDCOD increase as Methane yield (ml/gVS)=4.66 DDCOD-9.69. PMID:24703958

  19. The (Very) Slow Rotation of Magnetic Ap Stars

    NASA Astrophysics Data System (ADS)

    Mathys, Gautier

    2015-08-01

    To this date, 34 magnetic Ap stars that have periods of variation longer than 30 days are known. They represent a considerable fraction of the total number of Ap stars whose period has been reliably determined. All the available evidence unambiguously indicates that the observed variations of those long-period Ap stars result from the changing aspect of their visible hemisphere as they rotate, thus that the oblique rotator model is applicable throughout the whole range of periods of variation of the Ap stars. We show that the periods of the most slowly rotating Ap stars must be of the order of 300 years, and that some may even be longer, possibly up to 1000 years. The 5 to 6 orders of magnitude spanned by the rotation periods of the Ap stars present a major challenge for the understanding of their origin and their evolution. To guide the theo- retical developments, observational hints may be found in possible differences between the magnetic properties of stars that have rotation periods in different ranges. Such differences are starting to emerge from the existing data. To increase their significance level, study of the longest-period stars must be continued over their full rotation cycle. Failure to secure observations now may leave critical data missing for several decades, or even centuries.

  20. Thermal Decomposition Characteristics of Orthorhombic Ammonium Perchlorate (o-AP)

    SciTech Connect

    Behrens, R.; Minier, L.

    1999-03-01

    Preliminary STMBMS and SEM results of the thermal decomposition of AP in the orthorhombic phase are presented. The overall decomposition is shown to be complex and controlled by both physical and chemical processes. The data show that the physical and chemical processes can be probed and characterized utilizing SEM and STMBMS. The overall decomposition is characterized by three distinguishing features: an induction period, and accelerator period and a deceleratory period. The major decomposition event occurs in the subsurface of the AP particles and propagates towards the center of the particle with time. The amount of total decomposition is dependent upon particle size and increases from 23% for {approximately}50{micro}m-diameter AP to 33% for {approximately}200{micro}m-diameter AP. A conceptual model of the physical processes is presented. Insight into the chemical processes is provided by the gas formation rates that are measured for the gaseous products. To our knowledge, this is the first presentation of data showing that the chemical and physical decomposition processes can be identified from one another, probed and characterized at the level that is required to better understand the thermal decomposition behavior of AP. Future work is planned with the goal of obtaining data that can be used to develop a mathematical description for the thermal decomposition of o-AP.