Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

Institute of Scientific and Technical Information of China (English)

FANG，Yu; YIN，Yi－Qing; 等

2002-01-01

The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques.It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes.The aggregates are not solvolyzed in acetone,and do not take part n any chemical reactions either.It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone.The aggregation is reversible,and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

Monitoring the Aggregation of Dansyl Chloride in Acetone through Fluorescence Measurements

Institute of Scientific and Technical Information of China (English)

FANG,Yu(房喻); YIN,Yi-Qing(尹艺青); HU,Dao-Dao(胡道道); GAO,Gai-Ling(高改玲)

2002-01-01

The aggregation of dansyl chloride (DNS-Cl) in acetone has been studied in detail by steady-state fluorescence techniques. It has been demonstrated that DNS-Cl is stable in acetone during purification and aggregation study processes. The aggregates are not solvolyzed in acetone, and do not take part in any chemical reactions either. It has been found that DNS-Cl tends to aggregate even when its concentration is much lower than its solubility in acetone. The aggregation is reversible, and both the aggregation and the deaggregation are very slow processes.Introduction of SDS has a positive effect upon the formation and stabilization of the aggregates.

Bromate Formation Characteristics of UV Irradiation, Hydrogen Peroxide Addition, Ozonation, and Their Combination Processes

Directory of Open Access Journals (Sweden)

Naoyuki Kishimoto

2012-01-01

Full Text Available Bromate formation characteristics of six-physicochemical oxidation processes, UV irradiation, single addition of hydrogen peroxide, ozonation, UV irradiation with hydrogen peroxide addition (UV/H2O2, ozonation with hydrogen peroxide addition (O3/H2O2, and ozonation with UV irradiation (O3/UV were investigated using 1.88 μM of potassium bromide solution with or without 6.4 μM of 4-chlorobenzoic acid. Bromate was not detected during UV irradiation, single addition of H2O2, and UV/H2O2, whereas ozone-based treatments produced . Hydroxyl radicals played more important role in bromate formation than molecular ozone. Acidification and addition of radical scavengers such as 4-chlorobenzoic acid were effective in inhibiting bromate formation during the ozone-based treatments because of inhibition of hydroxyl radical generation and consumption of hydroxyl radicals, respectively. The H2O2 addition was unable to decompose 4-chlorobenzoic acid, though O3/UV and O3/H2O2 showed the rapid degradation, and UV irradiation and UV/H2O2 showed the slow degradation. Consequently, if the concentration of organic contaminants is low, the UV irradiation and/or UV/H2O2 are applicable to organic contaminants removal without bromate formation. However, if the concentration of organic contaminants is high, O3/H2O2 and O3/UV should be discussed as advanced oxidation processes because of their high organic removal efficiency and low bromate formation potential at the optimum condition.

Acetone poisoning

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002480.htm Acetone poisoning To use the sharing features on this page, please enable JavaScript. Acetone is a chemical used in many household products. ...

Laser-induced fluorescence imaging of acetone inside evaporating and burning fuel droplets

Science.gov (United States)

Shringi, D. S.; Shaw, B. D.; Dwyer, H. A.

2009-01-01

Laser-induced fluorescence was used to visualize acetone fields inside individual droplets of pure acetone as well as droplets composed of methanol or 1-propanol initially mixed with acetone. Droplets were supported on a horizontal wire and two vaporization conditions were investigated: (1) slow evaporation in room air and (2) droplet combustion, which leads to substantially faster droplet surface regression rates. Acetone was preferentially gasified, causing its concentration in droplets to drop in time with resultant decreases in acetone fluorescence intensities. Slowly vaporizing droplets did not exhibit large spatial variations of fluorescence within droplets, indicating that these droplets were relatively well mixed. Ignition of droplets led to significant variations in fluorescence intensities within droplets, indicating that these droplets were not well mixed. Ignited droplets composed of mixtures of 1-propanol and acetone showed large time-varying changes in shapes for higher acetone concentrations, suggesting that bubble formation was occurring in these droplets.

Evidence for CO formation in irradiated methanol and acetone: contribution of low-energy electron-energy-loss spectroscopy to γ-radiolysis

International Nuclear Information System (INIS)

Jay-Gerin, J.-P.; Fraser, M.-J.; Michaud, M.; Sanche, L.; Swiderek, P.; Ferradini, C.

1997-01-01

Energy-loss spectra for low-energy electrons incident on acetone condensed on a multilayer film of argon, and on a methanol film deposited on a metallic substrate, are reported. In both cases, the formation of carbon monoxide has been detected. These results are directly related to those obtained in the liquid-phase γ-radiolysis of the two compounds. (author)

Characterisation of cellulose films regenerated from acetone/water coagulants.

Science.gov (United States)

Geng, Hongjuan; Yuan, Zaiwu; Fan, Qingrui; Dai, Xiaonan; Zhao, Yue; Wang, Zhaojiang; Qin, Menghua

2014-02-15

A precooled aqueous solution of 7 wt% NaOH/12 wt% urea was used to dissolve cellulose up to a concentration of 2 wt%, which was then coagulated in an acetone/water mixture to regenerate cellulose film. The volume ratio of acetone to water (φ) had a dominant influence on film dimensional stability, film-forming ability, micromorphology, and mechanical strength. The film regenerated at φ=2.0 showed excellent performance in both dimensional stability and film-forming ability. Compared to that from pure acetone, the cellulose film from the acetone/water mixture with φ=2.0 was more densely interwoven, since the cellulosic fibrils formed during regeneration had pores with smaller average diameter. The alkali capsulated in the film during film formation could be released at quite a slow rate into the surrounding aqueous solution. The regenerated cellulose film with adjustable structure and properties may have potential applications in drug release and ultra filtration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Peroxide organometallic compounds and their transformations

International Nuclear Information System (INIS)

Razuvaev, G.A.; Brilkina, T.G.

1976-01-01

A survey is given experimental works on synthesis and reactions of peroxide organometallic compounds. Reactions have been considered of organometallic compounds with oxygen and organic peroxides which result in formation of both peroxide and non-peroxide products. Possible routes and mechanisms of chemical transformations of peroxide organometallic compounds have been discussed. Reactions of organometallic compounds with oxygen and peroxides have been considered

Formation of Hydrogen Peroxide by Electrochemical Reduction of Molecular Oxygen using Luminol Chemiluminescence

International Nuclear Information System (INIS)

Rana, Sohail

2005-01-01

Formation of hydrogen peroxide by electrochemical reduction of molecular oxygen was examined by measuring luminol chemiluminescence and absorption spectrum using flow-injection method. Ferryl porphyrin is widely accepted as responsible species to stimulate the emission in hydrogen peroxide/ iron porphyrin/ luminol system. Emission was observed under cathodic potentials (0.05V at pH2.0 and -0.3V at pH11.0) by the electrochemical reduction of aerated electrolytes solution but emission was observed at anodic potentials. Iron porphyrin solution was added at down stream of the working electrode and was essential for the emission. Removal of the dissolved molecular oxygen resulted in the decrease of emission intensity by more than 70%. In order to examine the life time of reduced active species, delay tubes were introduced between working electrode Fe TMPyP inlet. Experimental results suggested the active species were stable for quite a long period. The emission was quenched considerably (>90%) when hydroperoxy was added at the down stream of working electrode whereas the Superoxide dismutase (SOD) had little effect and mannitol had no effect. The spectra at reduction potential under aerated condition were shifted to the longer wavelength (>430nm) compared to the original spectrum of Fe TMPyP (422nm), indicating that the ferryl species were mixed to some extent. These observations lead to the conclusion that hydrogen peroxide was produced first by electrochemical reduction of molecular oxygen which then converted Fe TMPyP into O=FeTMPyP to activate luminol. Comparing emission intensities with the reference experiments, the current efficiencies for the formation of hydrogen peroxide were estimated as about 30-65% in all over the pH range used. (author)

Production of acetone and conversion of acetone to acetate in the perfused rat liver

International Nuclear Information System (INIS)

Gavino, V.C.; Somma, J.; Philbert, L.; David, F.; Garneau, M.; Belair, J.; Brunengraber, H.

1987-01-01

The utilization of millimolar concentrations of [2- 14 C]acetone and the production of acetone from acetoacetate were studied in perfused livers from 48-h starved rats. We devised a procedure for determining, in a perfused liver system, the first-order rate constant for the decarboxylation of acetoacetate (0.29 +/- 0.09 h-1, S.E., n = 8). After perfusion of livers with [2- 14 C]acetone, labeled acetate was isolated from the perfusion medium and characterized as [1- 14 C]acetate. No radioactivity was found in lactate or 3-hydroxybutyrate. After 90 min of perfusion with [2- 14 C]acetone, the specific activity of acetate was 30 +/- 4% (n = 13) of the initial specific activity of acetone. We conclude that, in perfused livers from 2-day starved rats, acetone metabolism occurs for the most part via free acetate

Synthesis of complex compounds in the system [ReOG5]2--thiosemicarbazone acetone-Hg-acetone

International Nuclear Information System (INIS)

Amindzhanov, A.A.; Kurbanov, N.M.

1993-01-01

Present article is devoted to synthesis of complex compounds in the system [ReOG 5 ] 2- -thiosemicarbazone acetone-Hg-acetone. The literature data on complex compounds of various metals with thiosemicarbazone was summarized. The synthesis of complex compounds in the system [ReOG 5 ] 2- -thiosemicarbazone acetone-Hg-acetone was conducted. The complex compounds of rhenium with methyl ident thiosemicarbazone were synthesized.

Regeneration of granular activated carbon saturated with acetone and isopropyl alcohol via a recirculation process under H2O2/UV oxidation.

Science.gov (United States)

Horng, Richard S; Tseng, I-Chin

2008-06-15

This study examines a water-based system, coupling an adsorber and a photoreactor, for regeneration of granular activated carbon (GAC) saturated with acetone and isopropyl alcohol (IPA). Through water recirculation the regeneration reaction was operated in both intermittent and continuous ultraviolet illumination modes. With a periodic dosage of hydrogen peroxide not only was regeneration efficient but it was also catalyzed by GAC in the adsorber. The concentrations of acetone, solution chemical oxygen demand (COD), pH and organic residues on GAC surfaces were measured during regenerations. Both pH and solution COD were found to correlate with regeneration completion as measured by organic residue on GAC surfaces in four regeneration cycles with acetone. Solution pH decreased to the acidic values and then returned to near its original value when organic residues were 0.085-0.255 mg/g GAC, that is, destruction efficiency of adsorbed acetone on the GAC surface was more than 99%. Likewise, solution COD became low (properties in each of eight cycles: adsorptive capacities were 95+/-7 mg acetone/g GAC and 87+/-3 mg IPA/g GAC, and breakthrough time was 0.86+/-0.05 for acetone and 0.78+/-0.03 h for IPA. An economic assessment of the system showed that the operating cost was about 0.04 USD for treating every gram of acetone in the air.

Application of lipid peroxidation and protein oxidation biomarkers for oxidative damage in mammalian cells. A comparison with two fluorescent probes

NARCIS (Netherlands)

Orhan, H.; Gurer-Orhan, H.; Vriese, E.; Vermeulen, N.P.E.; Meerman, J.H.N.

2006-01-01

We recently developed two biomarker sets for oxidative damage: one for determination of lipid peroxidation (LPO) degradation products; acetaldehyde, propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, malondialdehyde and acetone, by a gas chromatography-electron capture detection

Acetone production with metabolically engineered strains of Acetobacterium woodii.

Science.gov (United States)

Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

2016-07-01

Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Singlet oxygen-mediated formation of protein peroxides within cells

International Nuclear Information System (INIS)

Wright, A.; Policarpio, V.

2003-01-01

Full text: Singlet oxygen is generated by a number of cellular, enzymatic and chemical reactions as well as by exposure to UV, or visible light in the presence of a sensitizer; as a consequence this oxidant has been proposed as a damaging agent in a number of pathologies including photo-aging and skin cancer. Proteins are major targets for singlet oxygen as a result of their abundance and high rate constants for reaction. In this study it is shown that illumination of viable, sensitizer-loaded, THP-1 (human monocyte-like) cells with visible light gives rise to intra-cellular protein-derived peroxides. The peroxide yield increases with illumination time, requires the presence of the sensitizer, is enhanced in D 2 O, and decreased by azide; these data are consistent with the mediation of singlet oxygen. The concentration of peroxides detected, which is not affected by glucose or ascorbate loading of the cells, corresponds to ca. 1.5 nmoles peroxide per 10 6 cells using rose bengal as sensitizer, or 10 nmoles per mg cell protein and account for up to ca. 15% of the O 2 consumed by the cells. Similar peroxides have been detected on isolated cellular proteins exposed to light in the presence of rose bengal and oxygen. After cessation of illumination, the cellular protein peroxide levels decreases with t 1/2 ca. 4 hrs at 37 deg C, and this is associated with increased cell lysis. Decomposition of protein peroxides formed within cells, or on isolated cellular proteins, by metal ions, gives rise to radicals as detected by EPR spin trapping. These protein peroxides, and radicals derived from them, can inactivate key cellular enzymes (including caspases, GAPDH and glutathione reductase) and induce DNA base oxidation, strand breaks and DNA-protein cross-links. These studies demonstrate that exposure of intact cells to visible light in the presence of a sensitizer gives rise to novel long-lived, but reactive, intra-cellular protein peroxides via singlet oxygen

BaFe{sub 12}O{sub 19} powder with high magnetization prepared by acetone-aided coprecipitation

Energy Technology Data Exchange (ETDEWEB)

Yu, Hsuan-Fu, E-mail: hfyu@mail.tku.edu.tw

2013-09-15

BaFe{sub 12}O{sub 19} particles with high magnetization were produced using an acetone-aided coprecipitation process. An aqueous solution of iron and barium nitrates, in an Fe{sup 3+}/Ba{sup 2+} molar ratio of 12, was added in a stirred precipitation liquid medium composed of H{sub 2}O, CH{sub 3}(CO)CH{sub 3} and NH{sub 4}OH. After reacting metallic ions with ammonia, the precipitates were formed, centrifugally filtered, freeze dried and calcined. Effects of amount of the acetone in the precipitation liquid medium on the formation of crystalline BaFe{sub 12}O{sub 19} were investigated. The presence of acetone in the precipitation liquid medium can greatly promote formation of the crystalline BaFe{sub 12}O{sub 19} at temperature as low as 650 °C and can enhance magnetization of the derived particles. On the other hand, raising the calcination temperature can effectively accelerate development of crystallite morphology and magnetic characters of the barium hexaferrites. While the barium hexaferrite powder obtained without acetone additions and calcined at 1000 °C had magnetization (measured at 50 kOe; M(50 kOe)) of 63.5 emu/g, remanence magnetization (Mr) of 31.3 emu/g and coercivity (Hc) of 4.7 kOe, the single magnetic domain size BaFe{sub 12}O{sub 19} powder with M(50 kOe) of 70.6 emu/g, Mr of 34.4 emu/g and Hc of 3.7 kOe was produced at 1000 °C, using a precipitation liquid medium of 64 vol% acetone. - Highlights: • BaFe{sub 12}O{sub 19} with high magnetic characters was produced by an acetone-aided coprecipitation. • The effects of acetone addition in the precipitation on the formation of BaFe{sub 12}O{sub 19} were studied. • Acetone presence in the precipitation liquid medium promoted BaFe{sub 12}O{sub 19} formation at ≥650 °C. • BaFe{sub 12}O{sub 19} with M(50 kOe) of 70.6 emu/g, Mr of 34.4 emu/g and Hc of 3.7 kOe was obtained.

Is breath acetone a biomarker of diabetes? A historical review on breath acetone measurements.

Science.gov (United States)

Wang, Zhennan; Wang, Chuji

2013-09-01

Since the ancient discovery of the 'sweet odor' in human breath gas, pursuits of the breath analysis-based disease diagnostics have never stopped. Actually, the 'smell' of the breath, as one of three key disease diagnostic techniques, has been used in Eastern-Medicine for more than three thousand years. With advancement of measuring technologies in sensitivity and selectivity, more specific breath gas species have been identified and established as a biomarker of a particular disease. Acetone is one of the breath gases and its concentration in exhaled breath can now be determined with high accuracy using various techniques and methods. With the worldwide prevalence of diabetes that is typically diagnosed through blood testing, human desire to achieve non-blood based diabetic diagnostics and monitoring has never been quenched. Questions, such as is breath acetone a biomarker of diabetes and how is the breath acetone related to the blood glucose (BG) level (the golden criterion currently used in clinic for diabetes diagnostic, monitoring, and management), remain to be answered. A majority of current research efforts in breath acetone measurements and its technology developments focus on addressing the first question. The effort to tackle the second question has begun recently. The earliest breath acetone measurement in clearly defined diabetic patients was reported more than 60 years ago. For more than a half-century, as reviewed in this paper, there have been more than 41 independent studies of breath acetone using various techniques and methods, and more than 3211 human subjects, including 1581 healthy people, 242 Type 1 diabetic patients, 384 Type 2 diabetic patients, 174 unspecified diabetic patients, and 830 non-diabetic patients or healthy subjects who are under various physiological conditions, have been used in the studies. The results of the breath acetone measurements collected in this review support that many conditions might cause changes to breath

Recycling of acetone by distillation

International Nuclear Information System (INIS)

Brennan, D.L.; Campbell, B.A.; Phelan, J.E.; Harper, M.

1992-09-01

The Resource Conservation Recovery Act (RCRA) identifies spent acetone solvent as a listed hazardous waste. At Fernald, acetone has been spent that has been contaminated with radionuclides and therefore is identified as a mixed hazardous waste. At the time of this publication there is no available approved method of recycling or disposal of radioactively contaminated spent acetone solvent. The Consent Decree with the Ohio EPA and the Consent Agreement with the United States EPA was agreed upon for the long-term compliant storage of hazardous waste materials. The purpose of this project was to demonstrate the feasibility for safely decontaminating spent acetone to background levels of radioactivity for reuse. It was postulated that through heat distillation, radionuclides could be isolated from the spent acetone

21 CFR 173.210 - Acetone.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetone. 173.210 Section 173.210 Food and Drugs..., Lubricants, Release Agents and Related Substances § 173.210 Acetone. A tolerance of 30 parts per million is established for acetone in spice oleoresins when present therein as a residue from the extraction of spice. ...

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

Energy Technology Data Exchange (ETDEWEB)

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.

Viscosities and refractive indices of binary systems acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol

Directory of Open Access Journals (Sweden)

Živković Emila M.

2014-01-01

Full Text Available Viscosities and refractive indices of three binary systems, acetone+1-propanol, acetone+1,2-propanediol and acetone+1,3-propanediol, were measured at eight temperatures (288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15K and at atmospheric pressure. From these data viscosity deviations and deviations in refractive index were calculated and fitted to the Redlich-Kister equation. The viscosity modelling was done by two types of models: predictive UNIFAC-VISCO and ASOG VISCO and correlative Teja-Rice and McAlister equations. The refractive indices of binary mixtures were predicted by various mixing rules and compared with experimental data. [Projekat Ministarstva nauke Republike Srbije, br. 172063

Determination of breath acetone in 149 type 2 diabetic patients using a ringdown breath-acetone analyzer.

Science.gov (United States)

Sun, Meixiu; Chen, Zhuying; Gong, Zhiyong; Zhao, Xiaomeng; Jiang, Chenyu; Yuan, Yuan; Wang, Zhennang; Li, Yingxin; Wang, Chuji

2015-02-01

Over 90% of diabetic patients have Type 2 diabetes. Although an elevated mean breath acetone concentration has been found to exist in Type 1 diabetes (T1D), information on breath acetone in Type 2 diabetes (T2D) has yet to be obtained. In this study, we first used gas chromatography-mass spectrometry (GC-MS) to validate a ringdown breath-acetone analyzer based on the cavity-ringdown-spectroscopy technique, through comparing breath acetone concentrations in the range 0.5-2.5 ppm measured using both methods. The linear fitting of R = 0.99 suggests that the acetone concentrations obtained using both methods are consistent with a largest standard deviation of ±0.4 ppm in the lowest concentration of the range. Next, 620 breath samples from 149 T2D patients and 42 healthy subjects were collected and tested using the breath analyzer. Four breath samples were taken from each subject under each of four different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner. Simultaneous blood glucose levels were also measured using a standard diabetic-management blood-glucose meter. For the 149 T2D subjects, their exhaled breath acetone concentrations ranged from 0.1 to 19.8 ppm; four different ranges of breath acetone concentration, 0.1-19.8, 0.1-7.1, 0.1-6.3, and 0.1-9.5 ppm, were obtained for the subjects under the four different conditions, respectively. For the 42 healthy subjects, their breath acetone concentration ranged from 0.1 to 2.6 ppm; four different ranges of breath acetone concentration, 0.3-2.6, 0.1-2.6, 0.1-1.7, and 0.3-1.6 ppm, were obtained for the four different conditions. The mean breath acetone concentration of the 149 T2D subjects was determined to be 1.5 ± 1.5 ppm, which was 1.5 times that of 1.0 ± 0.6 ppm for the 42 healthy subjects. No correlation was found between the breath acetone concentration and the blood glucose level of the T2D subjects and the healthy volunteers. This study using a relatively large number of

Toluene metabolism in isolated rat hepatocytes: effects of in vivo pretreatment with acetone and phenobarbital

Energy Technology Data Exchange (ETDEWEB)

Smith-Kielland, A.; Ripel, A. (National Inst. of Forensic Toxicology, Oslo (Norway))

1993-02-01

Hepatocytes isolated from control, acetone- and phenobarbital-pretreated rats were used to study the metabolic conversion of toluene to benzyl alcohol, benzaldehyde, benzoic acid and hippuric acid at low (<100 [mu]M) and high (100-500 [mu]M) toluene concentrations. The baseline formation rates of toluene metabolites (benzyl alcohol, benzoic acid and hippuric acid) were 2.9[+-]1.7 and 10.0[+-]2.3 nmol/mg cell protein/60 min at low and high toluene concentrations, respectively. In vivo pretreatment of rats with acetone and phenobarbital increased the formation of metabolites: at low toluene concentrations 3- and 5-fold, respectively; at high toluene concentrations no significant increase (acetone) and 8-fold increase (phenobarbital). Apparent inhibition by ethanol, 7 and 60 mM, was most prominent at low toluene concentrations: 63% and 69%, respectively, in control cells; 84% and 91% in acetone-pretreated cells, and 32% (not significant) and 51% in phenobarbital-pretreated cells. Ethanol also caused accumulation of benzyl alcohol. The apparent inhibition by isoniazid was similar to that of ethanol at low toluene concentrations. Control and acetone-pretreated cells were apparently resistant towards metyrapone; the decrease was 49% and 64% in phenobarbital-pretreated cells at low and high toluene concentrations, respectively. In these cells, the decrease in presence of combined ethanol and metyrapone was 95% (low toluene concentrations). 4-Methylpyrazole decreased metabolite formation extensively in all groups. Benzaldehyde was only found in the presence of an aldehyde dehydrogenase inhibitor. Increased ratio benzoic/hippuric acid was observed at high toluene concentrations. These results demonstrate that toluene oxidation may be studied by product formation in isolated hepatocytes. However, the influence of various enzymes in the overall metabolism could not be ascertained due to lack of inhibitor specificity. (orig.).

Chemical reactions in the nitrogen-acetone ice induced by cosmic ray analogues: relevance for the Solar system

Science.gov (United States)

de Barros, A. L. F.; Andrade, D. P. P.; da Silveira, E. F.; Alcantara, K. F.; Boduch, P.; Rothard, H.

2018-02-01

The radiolysis of 10:1 nitrogen:acetone mixture, condensed at 11 K, by 40 MeV 58Ni11 + ions is studied. These results are representative of studies concerning Solar system objects, such as transneptunian objects, exposed to cosmic rays. Bombardment by cosmic rays triggers chemical reactions leading to synthesis of larger molecules. In this work, destruction cross-sections of acetone and nitrogen molecules in solid phase are determined and compared with those for pure acetone. The N2 column density decreases very fast indicating that, under irradiation, nitrogen leaves quickly a porous sample. The most abundant molecular species formed in the radiolysis are C3H6, C2H6, N3, CO, CH4 and CO2. Some N-bearing species are also formed, but with low production yield. Dissolving acetone in nitrogen decreases the formation cross-sections of CH4, CO2 and H2CO, while increases those for CO and C2H6 species. This fact may explain the presence of C2H6 in Pluto's surface where CH4 is not pure, but diluted in an N2 matrix. The formation of more complex molecules, such as HNCO and, possibly, glycine is observed, suggesting the formation of small prebiotic species in objects beyond Neptune from acetone diluted in a N2 matrix irradiated by cosmic rays.

Mobility and molecular ions of dimethyl methyl phosphonate, methyl salicylate and acetone

Science.gov (United States)

Nowak, D. M.

1983-06-01

The mobilities of positive and negative reactant ions are reported for (H2O)nH(+); (H2O)2O2 and (H2O)2CO3(-) ion clusters. The formation of positive DMMP monomer and dimer is reported, and equilbria molecular reactions are reported. Acetone is reported as forming a dimer at 81 ppb with a reduced mobility (K sub o) of 1.82, Methyl salicylate is shown to form a protonated and hydrated positive monomer. Mixtures of DMMP and methyl salicylate with acetone showed a substantial change in DMMP ion clustering and little or no change in the methyl salicylate mobility spectra. Negative ions were not observed for DMMP, methyl salicylate, acetone and the mixtures under the conditions reported.

Measurements of acetone yields from the OH-initiated oxidation of terpenes by proton-transfer-reaction mass spectrometry

International Nuclear Information System (INIS)

Wisthaler, A.; Lindinger, W.; Jensen, N.R.; Winterhalter, R.; Hjorth, J.

2002-01-01

Biogenic VOCs (Volatile Organic Compounds) are known to be emitted in large quantities from vegetation exceeding largely global emissions of anthropogenic VOCs. Monoterpenes (C 10 H 16 ) are important constituents of biogenic VOC emissions. The atmospheric oxidation of Monoterpenes appears to be a potentially relevant source of acetone in the atmosphere. Acetone is present as a significant trace gas in the whole troposphere and influences in particular the atmospheric chemistry in the upper troposphere by substantially contributing to the formation of HO x radicals and peroxyacetyl nitrate (PAN). Acetone is formed promptly, following attack by the OH-radical on the terpene, via a series of highly unstable radical intermediates, but it is also formed slowly via the degradation of stable non-radical intermediates such as pinonaldehyde and nopinone. In order to investigate the relative importance of these processes, the OH-initiated oxidation of α-pinene and β-pinene was investigated in a chamber study, where the concentrations of monoterpenes, acetone, pinonaldehyde and nopinone were monitored by proton-transfer-reaction mass spectrometry (PTR-MS). It was found that significant amounts of acetone are formed directly, whenα-pinene and β-pinene are oxidized by the OH radical, but also secondary chemistry (degradation of primary reaction products) gives a significant contribution to the formation of acetone from monoterpenes. It can be concluded that atmospheric oxidation of monoterpenes contributes a significant fraction to the global acetone source strength. (nevyjel)

Mechanism of the Formation of Organic Derivatives of gamma-Zirconium Phosphate by Topotactic Reactions with Phosphonic Acids in Water and Water-Acetone Media.

Science.gov (United States)

Alberti, G.; Giontella, E.; Murcia-Mascarós, S.

1997-06-18

The rates of the topotactic reactions between gamma-zirconium phosphate and phenylphosphonic acid in water and water-acetone mixtures at various temperatures were investigated. The slow rates of the process in aqueous medium or in water-acetone mixtures at temperatures lower than 50 degrees C were attributed to a slow interdiffusion of O(2)P(OH)(2)(-) and O(2)P(OH)(C(6)H(5))(-) groups in the interlayer region of gamma-ZrP. Similar to ion-exchange processes, the replacement begins in the external part of the interlayer region and progresses toward the central region with the formation of an advancing phase boundary. In water-acetone mixtures at temperatures higher than 60 degrees C an exfoliation of gamma-ZrP was found. Thus, the initial process is very fast since the substitution can take place directly on the surface of the exfoliated gamma-lamellae. However, after a certain degree of substitution, a flocculation of the colloidal dispersion, which slows down the rate of the further topotactic substitution, was observed. Some considerations on the topotactic substitution occurring on the surface of the exfoliated lamellae and on the mechanism of the diffusion of the exchanging species in the interlayer region are also reported.

Radiation-induced heterogeneous polymerization of acrylamide in acetone and acetone--water mixtures

International Nuclear Information System (INIS)

Wada, T.; Sekiya, H.; Machi, S.

1975-01-01

The effects of temperature, dose rate, and monomer concentration on the heterogeneous polymerization of acrylamide in acetone--water mixtures have been studied. Heterogeneous polymerization takes place in mixtures containing less than 60 vol-percent water. The polymerization is steady in acetone and nonsteady in mixtures containing 10 to 50 vol-percent water. The average rate of polymerization is highest in mixtures with about 20 vol-percent water. Polymer molecular weight increases with the increasing water content in the range 0 to 10 vol-percent and does not change in the range of 30 to 70 vol-percent water. For the polymerization in acetone and an acetone-water 60/40 mixture, the activation energies are 2.3 and -1.8 kcal/mole, the dose rate exponents of rate are 0.78 and 0.52, and the monomer concentration exponents of rate are 0.5 and 1.6, respectively. The polymer molecular weight increases with decreasing dose rate, decreasing temperature, and increasing monomer concentration. These results are discussed in connection with the mechanism of heterogeneous polymerization and the solvent effect

Rubrene endoperoxide acetone monosolvate

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Kiyoaki Shinashi

2012-04-01

Full Text Available The title acetone solvate, C42H28O2·C3H6O [systematic name: 1,3,10,12-tetraphenyl-19,20-dioxapentacyclo[10.6.2.02,11.04,9.013,18]icosa-2(11,3,5,7,9,13,15,17-octaene acetone monosolvate], is a photooxygenation product of rubrene (systematic name: 5,6,11,12-tetraphenyltetracene. The molecule bends at the bridgehead atoms, which are linked by the O—O transannular bond, with a dihedral angle of 49.21 (6° between the benzene ring and the naphthalene ring system of the tetracene unit. In the crystal, the rubrene molecules are linked by C—H...O hydrogen bonds into a column along the c axis. The acetone solvent molecules form a dimer around a crystallographic inversion centre through a carbonyl–carbonyl dipolar interaction. A C—H...O hydrogen bond between the rubrene and acetone molecules is also observed.

Enzymology of acetone-butanol-isopropanol formation. Final technical report, June 1, 1985--July 31, 1997

Energy Technology Data Exchange (ETDEWEB)

Chen, Jiann-Shin

1998-03-01

Several species of anaerobic bacteria within the genus Clostridium produce acetone, n-butanol, and isopropanol (solvents), which are important industrial chemicals and fuel additives. Commercial production of solvents by the clostridia is a classical example of largescale chemical production by bacterial fermentation. Although the fermentation has been in use for decades, it still faces problems that include strain degeneration, a relatively low final product concentration due to butanol toxicity, and a need to fine-tune the growth conditions to achieve a high yield. The long-term goal of this project was to understand the fundamental properties of bacterial solvent production for the purpose of achieving a positive control on the metabolic switch leading to solvent production and on the proportion of useful products formed as well as of developing strategies for preventing the degeneration of producing strains. The objectives for the project included those approved in 1985 for the initial project period and those approved in 1988, 1991, and 1994 when the project was renewed. The objectives for the entire project period may be summarized as (1) To purify and characterize the enzymes that are specifically required for the formation of acetone, butanol, and isopropanol by the clostridia, (2) To clone and characterize the genes that encode enzymes or regulatory proteins for the production of solvents, and the emphasis was to determine the control mechanism for the transcription of the solvent-production genes, (3) To characterize the onset of solvent production and the intra- and extra-cellular parameters surrounding the metabolic switch to solvent production, and (4) To determine the genetic identity of the strains of solvent-producing clostridia that are currently in use by investigators around the world.

Y-Doped ZnO Nanorods by Hydrothermal Method and Their Acetone Gas Sensitivity

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Peng Yu

2013-01-01

Full Text Available Pure and yttrium- (Y- doped (1 at%, 3 at%, and 7 at% ZnO nanorods were synthesized using a hydrothermal process. The crystallography and microstructure of the synthesized samples were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and energy dispersive X-ray spectroscopy (EDX. Comparing with pure ZnO nanorods, Y-doped ZnO exhibited improved acetone sensing properties. The response of 1 at% Y-doped ZnO nanorods to 100 ppm acetone is larger than that of pure ZnO nanorods. The response and recovery times of 1 at% Y-doped ZnO nanorods to 100 ppm acetone are about 30 s and 90 s, respectively. The gas sensor based on Y-doped ZnO nanorods showed good selectivity to acetone in the interfere gases of ammonia, benzene, formaldehyde, toluene, and methanol. The formation mechanism of the ZnO nanorods was briefly analyzed.

Acetone-based cellulose solvent.

Science.gov (United States)

Kostag, Marc; Liebert, Tim; Heinze, Thomas

2014-08-01

Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Off-line breath acetone analysis in critical illness.

Science.gov (United States)

Sturney, S C; Storer, M K; Shaw, G M; Shaw, D E; Epton, M J

2013-09-01

Analysis of breath acetone could be useful in the Intensive Care Unit (ICU) setting to monitor evidence of starvation and metabolic stress. The aims of this study were to examine the relationship between acetone concentrations in breath and blood in critical illness, to explore any changes in breath acetone concentration over time and correlate these with clinical features. Consecutive patients, ventilated on controlled modes in a mixed ICU, with stress hyperglycaemia requiring insulin therapy and/or new pulmonary infiltrates on chest radiograph were recruited. Once daily, triplicate end-tidal breath samples were collected and analysed off-line by selected ion flow tube mass spectrometry (SIFT-MS). Thirty-two patients were recruited (20 males), median age 61.5 years (range 26-85 years). The median breath acetone concentration of all samples was 853 ppb (range 162-11 375 ppb) collected over a median of 3 days (range 1-8). There was a trend towards a reduction in breath acetone concentration over time. Relationships were seen between breath acetone and arterial acetone (rs = 0.64, p acetone concentration over time corresponded to changes in arterial acetone concentration. Some patients remained ketotic despite insulin therapy and normal arterial glucose concentrations. This is the first study to look at breath acetone concentration in ICU patients for up to 8 days. Breath acetone concentration may be used as a surrogate for arterial acetone concentration, which may in future have a role in the modulation of insulin and feeding in critical illness.

Hole localization, migration, and the formation of peroxide anion in perovskite SrTiO3

Science.gov (United States)

Chen, Hungru; Umezawa, Naoto

2014-07-01

Hybrid density functional calculations are carried out to investigate the behavior of holes in SrTiO3. As in many other oxides, it is shown that a hole tend to localize on one oxygen forming an O- anion with a concomitant lattice distortion; therefore a hole polaron. The calculated emission energy from the recombination of the localized hole and a conduction-band electron is about 2.5 eV, in good agreement with experiments. Therefore the localization of the hole or self-trapping is likely to be responsible for the green photoluminescence at low temperature, which was previously attributed to an unknown defect state. Compared to an electron, the calculated hole polaron mobility is three orders of magnitude lower at room temperature. In addition, two O- anions can bind strongly to form an O22- peroxide anion. No electronic states associated with the O22- peroxide anion are located inside the band gap or close to the band edges, indicating that it is electronically inactive. We suggest that in addition to the oxygen vacancy, the formation of the O22- peroxide anion can be an alternative to compensate acceptor doping in SrTiO3.

In-cloud multiphase behaviour of acetone in the troposphere: gas uptake, Henry's law equilibrium and aqueous phase photooxidation.

Science.gov (United States)

Poulain, Laurent; Katrib, Yasmine; Isikli, Estelle; Liu, Yao; Wortham, Henri; Mirabel, Philippe; Le Calvé, Stéphane; Monod, Anne

2010-09-01

Acetone is ubiquitous in the troposphere. Several papers have focused in the past on its gas phase reactivity and its impact on tropospheric chemistry. However, acetone is also present in atmospheric water droplets where its behaviour is still relatively unknown. In this work, we present its gas/aqueous phase transfer and its aqueous phase photooxidation. The uptake coefficient of acetone on water droplets was measured between 268 and 281K (γ=0.7 x 10(-2)-1.4 x 10(-2)), using the droplet train technique coupled to a mass spectrometer. The mass accommodation coefficient α (derived from γ) was found in the range (1.0-3.0±0.25) x 10(-2). Henry's law constant of acetone was directly measured between 283 and 298K using a dynamic equilibrium system (H((298K))=(29±5)Matm(-1)), with the Van't Hoff expression lnH(T)=(5100±1100)/T-(13.4±3.9). A recommended value of H was suggested according to comparison with literature. The OH-oxidation of acetone in the aqueous phase was carried out at 298K, under two different pH conditions: at pH=2, and under unbuffered conditions. In both cases, the formation of methylglyoxal, formaldehyde, hydroxyacetone, acetic acid/acetate and formic acid/formate was observed. The formation of small amounts of four hydroperoxides was also detected, and one of them was identified as peroxyacetic acid. A drastic effect of pH was observed on the yields of formaldehyde, one hydroperoxide, and, (to a lesser extent) acetic acid/acetate. Based on the experimental observations, a chemical mechanism of OH-oxidation of acetone in the aqueous phase was proposed and discussed. Atmospheric implications of these findings were finally discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Oxidative Stress Induced Lipid Peroxidation And DNA Adduct Formation In The Pathogenesis Of Multiple Myeloma And Lymphoma

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Tandon, Ravi

2013-02-01

Full Text Available Objective: To access the oxidative stress status by quantification of byproducts generated during lipid peroxidation and DNA breakdown products generated during DNA damage in the blood serum of multiple myeloma and lymphoma patients.Material & Methods: Case control study comprised of 40 patients of multiple myeloma and 20 patients of lymphoma along with 20 age and sex-matched healthy subjects as controls. Levels of Malondialdehyde and 8-hydroxy-2-deoxy-Guanosine were measured to study the oxidative stress status in the study subjects.Results: The level of markers of DNA damage and lipid peroxidation were found to be raised significantly in the study subjects in comparison to healthy controls. The results indicate oxidative stress and DNA damage activity increase progressively with the progression of disease.Conclusion: Oxidative stress causes DNA damage and Lipid peroxidation which results in the formation of DNA adducts leading to mutations thereby indicate the role of oxidative stress in the pathogenesis of multiple myeloma and lymphoma.

Effect of Gold Dispersion on the Photocatalytic Activity of Mesoporous Titania for the Vapor-Phase Oxidation of Acetone

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S. V. Awate

2008-01-01

Full Text Available Mesostructured titanium dioxide photocatalyst, having uniform crystallite size (6–12 nm and average pore diameter of ∼4.2 nm, was synthesized by using a low-temperature nonsurfactant hydrothermal route, employing tartaric acid as a templating agent. Gold additions from 0.5 to 2 wt% were incorporated, either during the hydrothermal process or by postsynthesis wet impregnation. Compared to the impregnation-prepared samples, the samples synthesized hydrothermally contained smaller-size (≤1 nm gold clusters occluded in the pores of the host matrix. Whereas CO2 and H2O were the main reaction products in UV-assisted vapor-phase oxidation of acetone using these catalysts, C2H6 and HCO2CH3 were also produced for higher acetone concentrations in air. The conversion of acetone was found to increase with decrease in the size of both TiO2 and gold particles. In situ IR spectroscopy revealed that titania and gold particles serve as independent adsorption and reaction sites for acetone and oxygen molecules. Acetone molecules adsorb exclusively at TiO2 surface, giving rise to a strongly adsorbed (condensed state as well as to the formation of formate- and methyl formate-type surface species. Hydroxyl groups at titania surface participate directly in these adsorption steps. Nanosize gold particles, on the other hand, were primarily responsible for the adsorption and activation of oxygen molecules. Mechanistic aspects of the photochemical processes are discussed on the basis of these observations.

Photo-oxidation of histidine peptides yields high concentrations of unstable peroxides

International Nuclear Information System (INIS)

Policarpio, V.V.; Hawkins, C.L.; Davies, M.J.

2003-01-01

Oxidation of proteins by UV, and visible light in the presence of sensitizers, results in side chain modification as well as aggregation and fragmentation. In particular, singlet oxygen has been reported to oxidize Met, Trp, Tyr, Cys and His side chains in a selective manner. In this study the oxidation of histidine and its derivatives, and His-containing peptides is examined using a range of sensitizers, to determine whether peroxides are major intermediates, and the mechanism of formation of these species. Visible light-sensitised oxidation of Gly-His-Gly in the presence of oxygen and rose bengal gives unstable substrate-derived peroxides with the peroxide yield increasing with increasing photolysis time. Similar behaviour was detected with other photosensitizers, though the peroxide yields varied with the sensitizer at identical concentrations with rose bengal > aluminium phthalocyanine > hematoporphyrin IX > zinc phthalocyanine > tetrakisporphine. The peroxide yield was decreased in the presence of azide and enhanced when deuterium oxide was employed as the solvent, consistent with peroxide formation being singlet oxygen mediated. Experiments using anoxic conditions gave low yields of peroxides confirming the oxygen-dependence of these reactions. HPLC analysis showed rapid loss of the parent peptide, with subsequent formation of both stable and unstable products; these are currently being characterized by MS and NMR. Similar behavior has been observed with other His derivatives. The yield of singlet oxygen formed in these reactions has been estimated using a bleaching assay (N, N-dimethyl-4-nitrosoaniline). Quantification of singlet oxygen formation and Gly-His-Gly derived peroxide during rose bengal-mediated photooxidation indicated a conversion efficiency of the initial singlet oxygen into substrate-derived peroxides of ca. 75% indicating that peroxide formation is a highly efficient and major reaction pathway

Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature

International Nuclear Information System (INIS)

Abbatt, J P D; Bartels-Rausch, T; Ullerstam, M; Ye, T J

2008-01-01

The interactions of gas-phase acetone, ethanol and benzene with smooth ice films and artificial snow have been studied. In one technique, the snow is packed into a cylindrical column and inserted into a low-pressure flow reactor coupled to a chemical-ionization mass spectrometer for gas-phase analysis. At 214 and 228 K, it is found for acetone and ethanol that the adsorbed amounts per surface area match those for adsorption to thin films of ice formed by freezing liquid water, when the specific surface area of the snow (as determined from Kr adsorption at 77 K) and the geometric surface area of the ice films are used. This indicates that freezing thin films of water leads to surfaces that are smooth at the molecular level. Experiments performed to test the effect of film growth on ethanol uptake indicate that uptake is independent of ice growth rate, up to 2.4 μm min -1 . In addition, traditional Brunauer-Emmett-Teller (BET) experiments were performed with these gases on artificial snow from 238 to 266.5 K. A transition from a BET type I isotherm indicative of monolayer formation to a BET type II isotherm indicative of multilayer uptake is observed for acetone at T≥263 K and ethanol at T≥255 K, arising from solution formation on the ice. When multilayer formation does not occur, as was the case for benzene at T≤263 K and for acetone at T≤255 K, the saturated surface coverage increased with increasing temperature, consistent with the quasi-liquid layer affecting adsorption prior to full dissolution/multilayer formation.

Enhancing acetone biosynthesis and acetone-butanol-ethanol fermentation performance by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae integrated with exogenous acetate addition.

Science.gov (United States)

Luo, Hongzhen; Ge, Laibing; Zhang, Jingshu; Ding, Jian; Chen, Rui; Shi, Zhongping

2016-01-01

Acetone is the major by-product in ABE fermentations, most researches focused on increasing butanol/acetone ratio by decreasing acetone biosynthesis. However, economics of ABE fermentation industry strongly relies on evaluating acetone as a valuable platform chemical. Therefore, a novel ABE fermentation strategy focusing on bio-acetone production by co-culturing Clostridium acetobutylicum/Saccharomyces cerevisiae with exogenous acetate addition was proposed. Experimental and theoretical analysis revealed the strategy could, enhance C. acetobutylicum survival oriented amino acids assimilation in the cells; control NADH regeneration rate at moderately lower level to enhance acetone synthesis but without sacrificing butanol production; enhance the utilization ability of C. acetobutylicum on glucose and direct most of extra consumed glucose into acetone/butanol synthesis routes. By implementing the strategy using synthetic or acetate fermentative supernatant, acetone concentrations increased to 8.27-8.55g/L from 5.86g/L of the control, while butanol concentrations also elevated to the higher levels of 13.91-14.23g/L from 11.63g/L simultaneously. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrogen peroxide kinetics in water radiolysis

Science.gov (United States)

Iwamatsu, Kazuhiro; Sundin, Sara; LaVerne, Jay A.

2018-04-01

The kinetics of the formation and reaction of hydrogen peroxide in the long time γ- radiolysis of water is examined using a combination of experiment with model calculations. Escape yields of hydrogen peroxide on the microsecond time scale are easily measured with added radical scavengers even with substantial amounts of initial added hydrogen peroxide. The γ-radiolysis of aqueous hydrogen peroxide solutions without added radical scavengers reach a steady state limiting concentration of hydrogen peroxide with increasing dose, and that limit is directly proportional to the initial concentration of added hydrogen peroxide. The dose necessary to reach that limiting hydrogen peroxide concentration is also proportional to the initial concentration, but dose rate has a very small effect. The addition of molecular hydrogen to aqueous solutions of hydrogen peroxide leads to a decrease in the high dose limiting hydrogen peroxide concentration that is linear with the initial hydrogen concentration, but the amount of decrease is not stoichiometric. Proton irradiations of solutions with added hydrogen peroxide and hydrogen are more difficult to predict because of the decreased yields of radicals; however, with a substantial increase in dose rate there is a sufficient decrease in radical yields that hydrogen addition has little effect on hydrogen peroxide decay.

Subthreshold UV radiation-induced peroxide formation in cultured corneal epithelial cells: the protective effects of lactoferrin

International Nuclear Information System (INIS)

Shimmura, Shigeto; Suematsu, Makoto; Shimoyama, Masaru; Oguchi, Yoshihisa; Ishimura, Yuzuru

1996-01-01

Acute exposure to suprathreshold ultraviolet B radiation (UV-B) is known to cause photokeratitis resulting from the necrosis and shedding of corneal epithelial cells. However, the corneal effects of low dose UV-B in the environmental range is less clear. In this study, subthreshold UV-B was demonstrated to cause non-necrotic peroxide formation in cultured corneal epithelial cells, which was attenuated by the major tear protein lactoferrin. Intracellular oxidative insults and cell viability of rabbit corneal epithelial cells (RCEC) were assessed by dual-color digital microfluorography using carboxydichlorofluorescin (CDCFH) diacetate bis (acetoxymethyl) ester, a hydroperoxide-sensitive fluoroprobe, and propidium iodode (PI) respectively. The magnitude of UV-induced oxidative insults was calibrated by concentrations of exogenously applied H 2 O 2 which evoke compatible levels of CDCFH oxidation. Exposure of RCEC to low-dose UV-B (2.0 mJ cm -2 at 313 nm, 10.0 mJ cm -2 total UV-B) caused intracellular oxidative changes which were equivalent to those elicited by 240 μM hydrogen peroxide under the conditions of the study. The changes were dose dependent, non-necrotic, and were partially inhibited by lactoferrin ( 1 mg ml -1 ) but not by iron-saturated lactoferrin. Pretreatment with deferoxamine (2 mΜ) or catalase (100 U ml -1 ) also attenuated the UV-induced oxidative stress. The results indicate that UV-B comparable to solar irradiation levels causes significant intracellular peroxide formation in corneal epithelial cells, and that lactoferrin in tears may have a physiological role in protecting the corneal epithelium from solar UV irradiation. (Author)

Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins.

Science.gov (United States)

Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

2014-07-11

The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. In this study, a draft genome sequence of D. biacutus was established. Sequencing, assembly and annotation resulted in 159 contigs with 5,242,029 base pairs and 4773 predicted genes; 4708 were predicted protein-encoding genes, and 3520 of these had a functional prediction. Proteins and genes were identified that are specifically induced during growth with acetone. A thiamine diphosphate-requiring enzyme appeared to be highly induced during growth with acetone and is probably involved in the activation reaction. Moreover, a coenzyme B12- dependent enzyme and proteins that are involved in redox reactions were also induced during growth with acetone. We present for the first time the genome of a sulfate reducer that is able to grow with acetone. The genome information of this organism represents an important tool for the elucidation of a novel reaction mechanism that is employed by a sulfate reducer in acetone activation.

Portable method of measuring gaseous acetone concentrations.

Science.gov (United States)

Worrall, Adam D; Bernstein, Jonathan A; Angelopoulos, Anastasios P

2013-08-15

Measurement of acetone in human breath samples has been previously shown to provide significant non-invasive diagnostic insight into the control of a patient's diabetic condition. In patients with diabetes mellitus, the body produces excess amounts of ketones such as acetone, which are then exhaled during respiration. Using various breath analysis methods has allowed for the accurate determination of acetone concentrations in exhaled breath. However, many of these methods require instrumentation and pre-concentration steps not suitable for point-of-care use. We have found that by immobilizing resorcinol reagent into a perfluorosulfonic acid polymer membrane, a controlled organic synthesis reaction occurs with acetone in a dry carrier gas. The immobilized, highly selective product of this reaction (a flavan) is found to produce a visible spectrum color change which could measure acetone concentrations to less than ppm. We here demonstrate how this approach can be used to produce a portable optical sensing device for real-time, non-invasive acetone analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

Phage inactivation by triplet acetone

International Nuclear Information System (INIS)

Gomes, R.A.

1985-01-01

The exposure of lambda phage to triplet acetone is studied. The triplet acetone is obtained from aerobic oxidation of isobutanal catalysed by peroxidase. A decrease of lambda phage ability to infect Escherichia coli is reported, perhaps, partially due to the possible production of lesions in the phage genome. (M.A.C.) [pt

Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS).

Science.gov (United States)

Quirk, Emma; Doggett, Adrian; Bretnall, Alison

2014-08-05

Spray Dried Dispersions (SDD) are uniform mixtures of a specific ratio of amorphous active pharmaceutical ingredient (API) and polymer prepared via a spray drying process. Volatile solvents are employed during spray drying to facilitate the formation of the SDD material. Following manufacture, analytical methodology is required to determine residual levels of the spray drying solvent and its associated impurities. Due to the high level of polymer in the SDD samples, direct liquid injection with Gas Chromatography (GC) is not a viable option for analysis. This work describes the development and validation of an analytical approach to determine residual levels of acetone and acetone related impurities, mesityl oxide (MO) and diacetone alcohol (DAA), in drug product intermediates prepared as SDDs using GC with headspace (HS) autosampling. The method development for these analytes presented a number of analytical challenges which had to be overcome before the levels of the volatiles of interest could be accurately quantified. GCHS could be used after two critical factors were implemented; (1) calculation and application of conversion factors to 'correct' for the reactions occurring between acetone, MO and DAA during generation of the headspace volume for analysis, and the addition of an equivalent amount of polymer into all reference solutions used for quantitation to ensure comparability between the headspace volumes generated for both samples and external standards. This work describes the method development and optimisation of the standard preparation, the headspace autosampler operating parameters and the chromatographic conditions, together with a summary of the validation of the methodology. The approach has been demonstrated to be robust and suitable to accurately determine levels of acetone, MO and DAA in SDD materials over the linear concentration range 0.008-0.4μL/mL, with minimum quantitation limits of 20ppm for acetone and MO, and 80ppm for DAA. Copyright

Nitrate-Dependent Degradation of Acetone by Alicycliphilus and Paracoccus Strains and Comparison of Acetone Carboxylase Enzymes ▿

Science.gov (United States)

Dullius, Carlos Henrique; Chen, Ching-Yuan; Schink, Bernhard

2011-01-01

A novel acetone-degrading, nitrate-reducing bacterium, strain KN Bun08, was isolated from an enrichment culture with butanone and nitrate as the sole sources of carbon and energy. The cells were motile short rods, 0.5 to 1 by 1 to 2 μm in size, which gave Gram-positive staining results in the exponential growth phase and Gram-negative staining results in the stationary-growth phase. Based on 16S rRNA gene sequence analysis, the isolate was assigned to the genus Alicycliphilus. Besides butanone and acetone, the strain used numerous fatty acids as substrates. An ATP-dependent acetone-carboxylating enzyme was enriched from cell extracts of this bacterium and of Alicycliphilus denitrificans K601T by two subsequent DEAE Sepharose column procedures. For comparison, acetone carboxylases were enriched from two additional nitrate-reducing bacterial species, Paracoccus denitrificans and P. pantotrophus. The products of the carboxylase reaction were acetoacetate and AMP rather than ADP. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of cell extracts and of the various enzyme preparations revealed bands corresponding to molecular masses of 85, 78, and 20 kDa, suggesting similarities to the acetone carboxylase enzymes described in detail for the aerobic bacterium Xanthobacter autotrophicus strain Py2 (85.3, 78.3, and 19.6 kDa) and the phototrophic bacterium Rhodobacter capsulatus. Protein bands were excised and compared by mass spectrometry with those of acetone carboxylases of aerobic bacteria. The results document the finding that the nitrate-reducing bacteria studied here use acetone-carboxylating enzymes similar to those of aerobic and phototrophic bacteria. PMID:21841031

Problem of the lithium peroxide thermal stability

International Nuclear Information System (INIS)

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. (paper)

Fate of acetone in water

Science.gov (United States)

Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.

1982-01-01

The physical, chemical, and biological processes that might affect the concentration of acetone in water were investigated in laboratory studies. Processes considered included volatilization, adsorption by sediments, photodecomposition, bacterial degradation, and absorption by algae and molds. It was concluded that volatilization and bacterial degradation were the dominant processes determining the fate of acetone in streams and rivers. ?? 1982.

Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

Directory of Open Access Journals (Sweden)

Esin Akgul Kalkan

2016-01-01

Full Text Available Using high-performance liquid chromatography (HPLC and 2,4-dinitrophenylhydrazine (2,4-DNPH as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365 nm using an ultraviolet-visible (UV-Vis diode array detector (DAD. For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15 cm × 4.6 mm × 3 μm at retention time (tR 12.10 min and flowrate of 1 mL min−1 using a (methanol/acetonitrile water elution gradient. The methodology is simple, rapid, sensitive, and of low cost, exhibits good reproducibility, and allows the analysis of acetone in biological fluids. A calibration curve was obtained for acetone using its standard solutions in acetonitrile. Quantitative analysis of acetone in human blood was successfully carried out using this calibration graph. The applied method was validated in parameters of linearity, limit of detection and quantification, accuracy, and precision. We also present acetone as a useful tool for the HPLC-based metabolomic investigation of endogenous metabolism and quantitative clinical diagnostic analysis.

Interaction of silico-12-molybdic acid with acetone

International Nuclear Information System (INIS)

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

1984-01-01

Methods of thermal analysis, mass-spectrometry, IR, PMR, ESR spectroscopy are used to investigate interaction processes of silico-12-molybdic acid H 4 SiMo 12 O 40 with acetone. Reactions in solution and with participation of solid heteropolyacid are studied. Organic products of catalytic and oxidation-reduction reactions are identified. The effect of conditions on the formation of different condensation and oxidation products and the sequence of appropriate reactions is discussed. Transformations of silico-12-molybolic acid are considered

Methanogenic degradation of acetone by an enrichment culture

OpenAIRE

Platen, Harald; Schink, Bernhard

1987-01-01

An anaerobic enrichment culture degraded 1 mol of acetone to 2 tool of methane and 1 tool of carbon dioxide. Two microorganisms were involved in this process, a filament-forming rod similar to Methanothrix sp. and an unknown rod with round to slightly pointed ends. Both organisms formed aggregates up to 300 gm in diameter. No fluorescing bacteria were observed indicating that hydrogen or formate-utilizing methanogens are not involved in this process. Acetate was utilized in this culture by th...

Effects of Bronsted acidity in the mechanism of selective oxidation of propane to acetone on CaY zeolite at room temperature.

NARCIS (Netherlands)

Xu, J.; Mojet, Barbara; van Ommen, J.G.; Lefferts, Leonardus

2005-01-01

The importance of Brønsted acid sites for partial oxidation of propane to acetone in CaY was investigated by in situ FTIR spectroscopy. With an increasing number of protons in Ca-Y, Volcano plots were observed for (1) amount of adsorbed propane; (2) initial acetone formation rate; (3) total amount

Investigation of toxic effects of imidazolium ionic liquids, [bmim][BF4] and [omim][BF4], on marine mussel Mytilus galloprovincialis with or without the presence of conventional solvents, such as acetone.

Science.gov (United States)

Tsarpali, Vasiliki; Belavgeni, Alexia; Dailianis, Stefanos

2015-07-01

This study investigated the cytotoxic, oxidative and genotoxic effects of two commonly used imidazolium ionic liquids (ILs), [bmim][BF4] (1-butyl-3-methylimidazolium) and [omim][BF4] (1-methyl-3-octylimidazolium tetrafluoroborate), on the marine mussel Mytilus galloprovincialis, as well as whether acetone could mediate their toxic profile. In this context, mussels were firstly exposed to different concentrations of [bmim][BF4] or [omim][BF4], with or without the presence of acetone (at a final concentration of 0.06% v/v), for a period of 96h, in order to determine the concentration that causes 50% mussel mortality (LC50 values) in each case. Thereafter, mussels were exposed to sub- and non-lethal concentrations of ILs for investigating their ability to cause lysosomal membrane impairment (with the use of neutral red retention assay/NRRT), superoxide anion and lipid peroxidation byproduct (malondialdehyde/MDA) formation, as well as DNA damage and formation of nuclear abnormalities in hemocytes. The results showed that [omim][BF4] was more toxic than [bmim][BF4] in all cases, while the presence of acetone resulted in a slight attenuation of its toxicity. The different toxic behavior of ILs was further revealed by the significantly lower levels of NRRT values observed in [omim][BF4]-treated mussels, compared to those occurring in [bmim][BF4] in all cases. Similarly, [bmim][BF4]-mediated oxidative and genotoxic effects were observed only in the highest concentration tested (10mgL(-1)), while [omim][BF4]-mediated effects were enhanced at lower concentrations (0.01-0.05mgL(-1)). Overall, the present study showed that [bmim][BF4] and [omim][BF4] could induce not only lethal but also nonlethal effects on mussel M. galloprovincialis. The extent of [bmim][BF4] and/or [omim][BF4]-mediated effects could be ascribed to the length of each IL alkyl chain, as well as to their lipophilicity. Moreover, the role of acetone on the obtained toxic effects of the specific ILs was

Marine Vibrio Species Produce the Volatile Organic Compound Acetone

OpenAIRE

Nemecek-Marshall, M.; Wojciechowski, C.; Kuzma, J.; Silver, G. M.; Fall, R.

1995-01-01

While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

Acid phosphatase and lipid peroxidation in human cataractous lens epithelium

Directory of Open Access Journals (Sweden)

Vasavada Abhay

1993-01-01

Full Text Available The anterior lens epithelial cells undergo a variety of degenerative and proliferative changes during cataract formation. Acid phosphatase is primarily responsible for tissue regeneration and tissue repair. The lipid hydroperoxides that are obtained by lipid peroxidation of polysaturated or unsaturated fatty acids bring about deterioration of biological membranes at cellular and tissue levels. Acid phosphatase and lipid peroxidation activities were studied on the lens epithelial cells of nuclear cataract, posterior subcapsular cataract, mature cataract, and mixed cataract. Of these, mature cataractous lens epithelium showed maximum activity for acid phosphatase (516.83 moles of p-nitrophenol released/g lens epithelium and maximum levels of lipid peroxidation (86.29 O.D./min/g lens epithelium. In contrast, mixed cataractous lens epithelium showed minimum activity of acid phosphatase (222.61 moles of p-nitrophenol released/g lens epithelium and minimum levels of lipid peroxidation (54.23 O.D./min/g lens epithelium. From our study, we correlated the maximum activity of acid phosphatase in mature cataractous lens epithelium with the increased areas of superimposed cells associated with the formation of mature cataract. Likewise, the maximum levels of lipid peroxidation in mature cataractous lens epithelium was correlated with increased permeability of the plasma membrane. Conversely, the minimum levels of lipid peroxidation in mixed cataractous lens epithelium makes us presume that factors other than lipid peroxidation may also account for the formation of mixed type of cataract.

The relative importance of competing pathways for the formation of high-molecular-weight peroxides in the ozonolysis of organic aerosol particles

Directory of Open Access Journals (Sweden)

M. Mochida

2006-01-01

Full Text Available High-molecular-weight (HMW organic compounds are an important component of atmospheric particles, although their origins, possibly including in situ formation pathways, remain incompletely understood. This study investigates the formation of HMW organic peroxides through reactions involving stabilized Criegee intermediates (SCI's. The model system is methyl oleate (MO mixed with dioctyl adipate (DOA and myristic acid (MA in submicron aerosol particles, and Criegee intermediates are formed by the ozonolysis of the double bond in methyl oleate. An aerosol flow tube coupled to a quadrupole aerosol mass spectrometer (AMS is employed to determine the relative importance of different HMW organic peroxides following the ozonolysis of different mixing mole fractions of MO in DOA and MA. Possible peroxide products include secondary ozonides (SOZ's, α-acyloxyalkyl hydroperoxides and α-acyloxyalkyl alkyl peroxides (αAAHP-type compounds, diperoxides, and monoperoxide oligomers. Of these, the AMS data identify two SOZ's as major HMW products in the ozonolysis of pure methyl oleate as well as in an inert matrix of DOA to as low as 0.04 mole fraction MO. In comparison, in mixed particles of MO and MA, αAAHP-type compounds form in high yields for MO mole fractions of 0.5 or less, suggesting that SCI's efficiently attack the carboxylic acid group of myristic acid. The reactions of SCI's with carboxylic acid groups to form αAAHP-type compounds therefore compete with those of SCI's with aldehydes to form SOZ's, provided that both types of functionalities are present at significant concentrations. The results therefore suggest that SCI's in atmospheric particles contribute to the transformation of carboxylic acids and other protic groups into HMW organic peroxides.

Measuring breath acetone for monitoring fat loss: Review.

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Anderson, Joseph C

2015-12-01

Endogenous acetone production is a by-product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters. BrAce can range from 1 ppm in healthy non-dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement. When biologic factors are controlled, BrAce measurement provides a non-invasive tool for monitoring the rate of fat loss in healthy subjects. © 2015 The Authors Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

Comparison studies of surface cleaning methods for PAN-based carbon fibers with acetone, supercritical acetone and subcritical alkali aqueous solutions

International Nuclear Information System (INIS)

Meng Linghui; Fan Dapeng; Huang Yudong; Jiang Zaixing; Zhang Chunhua

2012-01-01

Highlights: ► Cleaning with supercritical acetone is appropriate to wipe off the oxygenated contaminants. ► Cleaning with supercritical acetone causes smaller damage to bulk strength of carbon fibers. ► Cleaning with subcritical alkali aqueous solution can thoroughly remove silicious contaminants. - Abstract: Four kinds of polyacrylonitrile-based carbon fibers were cleaned by three methods and were characterized by X-ray photoelectron spectroscopy, monofilament tensile strength test and atomic force microscopy (AFM). Experimental results of these tests reveal that the method using supercritical acetone or subcritical potassium hydroxide aqueous solution act as the processing medium shows a better cleaning effect compared to the traditional method, Soxhlet extraction with acetone. The method using supercritical acetone is more appropriate to wipe off the oxygenated contaminants on carbon fibers’ surfaces and causes a relatively smaller damage to the bulk strength of each carbon fiber. As far as treating method using the subcritical alkali aqueous solution, it can thoroughly remove silicious contaminants on the surfaces of treated fibers.

Surface tension anomalies in room temperature ionic liquids-acetone solutions

Science.gov (United States)

Abe, Hiroshi; Murata, Keisuke; Kiyokawa, Shota; Yoshimura, Yukihiro

2018-05-01

Surface tension anomalies were observed in room temperature ionic liquid (RTIL)-acetone solutions. The RTILs are 1-alkyl-3-methylimidazorium iodide with [Cnmim][I] in a [Cnmim][I]-x mol% acetone. The maximum value of the surface tension appeared at 40 mol% acetone, although density decreased monotonically with an increase in acetone concentration. A small alkyl chain length effect of the Cnmim+ cations was observed in the surface tension. By the Gibbs adsorption isotherm, it was found that I- anion-mediated surface structure became dominant above 40 mol%. In the different [Cnmim][TFSI]-acetone mixtures, normal decay of the surface tension was observed on the acetone concentration scale, where TFSI- is bis(trifluoromethanesulfonyl)imide.

Electron spectra and mechanism of complexing of uranyl nitrate in water-acetone solutions

International Nuclear Information System (INIS)

Zazhogin, A.A.; Zazhogin, A.P.; Komyak, A.I.; Serafimovich, A.I.

2003-01-01

Based on the analysis of the luminescence and electronic absorption spectra, the processes of complexing in an aqueous solution of UO 2 (NO 3 ) 2 ·6H 2 O with small additions of acetone have been studied. In a pure aqueous solution, uranyl exists as the complex UO 2 ·5H 2 O. It is shown that the addition of acetone to the solution leads to the displacement of some water molecules out of the first coordination sphere of uranyl and the formation of the uranyl nitrate dihydrate complexes UO 2 (NO 3 ) 2 ·2H 2 O. It has been established that the stability of these complexes is determined by the decrease in the water activity and in the degree of hydration of uranyl and nitrate, which is the result of the local increase in the concentration of acetone molecules (due to their hydrophobicity) in the regions of the solution where uranyl and nitrate ions are found. The experimental facts supported the mechanism proposed are presented. (authors)

Acetone utilization by sulfate-reducing bacteria: draft genome sequence of Desulfococcus biacutus and a proteomic survey of acetone-inducible proteins

OpenAIRE

Gutiérrez Acosta, Olga B; Schleheck, David; Schink, Bernhard

2014-01-01

Background The sulfate-reducing bacterium Desulfococcus biacutus is able to utilize acetone for growth by an inducible degradation pathway that involves a novel activation reaction for acetone with CO as a co-substrate. The mechanism, enzyme(s) and gene(s) involved in this acetone activation reaction are of great interest because they represent a novel and yet undefined type of activation reaction under strictly anoxic conditions. Results In this study, a draft genome sequence of D. biacutus ...

46 CFR 153.1035 - Acetone cyanohydrin or lactonitrile solutions.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Acetone cyanohydrin or lactonitrile solutions. 153.1035... Special Cargo Procedures § 153.1035 Acetone cyanohydrin or lactonitrile solutions. No person may operate a tankship carrying a cargo of acetone cyanohydrin or lactonitrile solutions, unless that cargo is stabilized...

In situ characterization of Ti-peroxy gel during formation on titanium surfaces in hydrogen peroxide containing solutions

International Nuclear Information System (INIS)

Muyco, Julie J.; Gray, Jeremy J.; Ratto, Timothy V.; Orme, Christine A.; McKittrick, Joanna; Frangos, John

2006-01-01

Three possible functions of Ti-peroxy gel are: reduction of the inflammatory response through the reduction of hydrogen peroxide and other reactive oxygen species; creation of a favorable surface for calcium phosphate nucleation; and as a transitional layer between the compliant surrounding tissue and the stiff titanium. Traditional surface characterization techniques operate in high vacuum environments that alter the actual sample-solution interface. Our studies used techniques that allowed samples to remain in solution and be observed over time. Atomic force microscopy (AFM) force-distance curves, electrochemical impedance spectroscopy (EIS), and Raman spectroscopy were each used in situ to define kinetic and mechanical properties of Ti-peroxy gel as it formed over time on titanium during exposure to hydrogen peroxide. Our studies enabled us to monitor real-time changes in the native oxide layer on titanium in hydrogen peroxide containing solution, including the formation of a Ti-peroxy gel layer above the native oxide. Peaks attributed to Ti-peroxy gel were seen to emerge over the course of several hours using in situ Raman spectroscopy. Force-distance curves suggest a layer that thickens with time on the titanium sample surface. EIS data showed that changes in the surface layers could be monitored in solution over time

Acetone n-radical cation internal rotation spectrum: The torsional potential surface

International Nuclear Information System (INIS)

Shea, Dana A.; Goodman, Lionel; White, Michael G.

2000-01-01

The one color REMPI and two color ZEKE-PFI spectra of acetone-d 3 have been recorded. The 3p x Rydberg state of acetone-d 3 lies at 59 362.3 cm-1 and both of the torsional modes are visible in this spectrum. The antigearing Rydberg (a 2 ) mode, v 12 * , has a frequency of 62.5 cm-1, while the previously unobserved gearing (b 1 ) mode, v 17 * , is found at 119.1 cm-1. An ionization potential of 78 299.6 cm-1 for acetone-d 3 has been measured. In acetone-d 3 n-radical cation ground state, the fundamentals of both of the torsional modes have been observed, v 12 + at 51.0 cm-1 and v 17 + at 110.4 cm-1, while the first overtone of v 12 + has been measured at 122.4 cm-1. Deuterium shifts show that v 12 + behaves like a local C 3v rotor, but that v 17 + is canonical. Combining this data with that for acetone-d 0 and aacetone-d 6 has allowed us to fit the observed frequencies to a torsional potential energy surface based on an ab initio C 2v cation ground state geometry. This potential energy surface allows for prediction of the v 17 vibration in acetone-d 0 and acetone-d 6 . The barrier to synchronous rotation is higher in the cation ground state than in the neutral ground state, but significantly lower than in the 3s Rydberg state. The 3p x Rydberg and cation ground state potential energy surfaces are found to be very similar to each other, strongly supporting the contention that the 3p x Rydberg state has C 2v geometry and is a good model for the ion core. The altered 3s Rydberg state potential surface suggests this state has significant valence character. (c) 2000 American Institute of Physics

Thermal and Ablative Properties of Ipns and Composites of High Ortho Resole Resin and Difurfurylidene Acetone

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Tariq S. NAJIM

2008-12-01

Full Text Available High ortho resole resin was prepared by condensation of phenol with excess of formaldehyde in the presence of magnesium oxide as catalyst. Reaction of furfuraldehyde with acetone in basic medium led to difurfurylidene acetone (DFA. Their interpenetrating polymer network (IPNS were obtained by the reaction of predetermined quantities of difurfurylidene acetone and high ortho resole using p-toluene sulphonic acid (PTSA as curing agent. The thermal behavior of the resins was studied using thermogravimetry (TG under ambient and nitrogen atmospheres over a temperature range of (25-1000 Cº. It was observed that the IPN of 20% DFA – 80% resole has higher thermal stability than that of resole alone and the decomposition temperature was higher by 80 Cº. This behavior was attributed to highly cross linked structure and thermally stable backbone of ploy difurfurylidene acetone due to formation of ladder structure.Impregnation of chopped fiber glass type (E with the polymeric solutions was used to prepare their composites, and the ablative properties were investigated according to ASTM E-285 –80. It was observed that the IPN of (DFA- resol perform better than the resole composite alone.

Toward Portable Breath Acetone Analysis for Diabetes Detection

Science.gov (United States)

Righettoni, Marco; Tricoli, Antonio

2013-01-01

Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Acetone is a selective breath marker for diabetes that may contribute to the monitoring of related metabolic disorder and thus simplify the management of this illness. Here, the overall performance of Si-doped WO3 nanoparticles made by flame spray pyrolysis as portable acetone detectors is critically reviewed focusing on the requirements for medical diagnostic. The effect of flow rate, chamber volume and acetone dissociation within the measuring chamber are discussed with respect to the calibration of the sensor response. The challenges for the fabrication of portable breath acetone sensors based on chemo-resistive detectors are underlined indicating possible solutions and novel research directions. PMID:21828897

Influence of concentration of sucrose on the acetone-butanol fermentation by different strains of Clostridium

Energy Technology Data Exchange (ETDEWEB)

Bahadue, K; Saroj, K K

1959-01-01

To culture media containing (NH/sub 4/)/sub 2/SO/sub 4/ (0.34 g) and MgSO/sub 4/ (0.16 g), were added 5, 10, and 20% sucrose, respectively; the pH was adjusted to 6.4 with KH/sub 2/PO/sub 4/-NaOH buffer; the volume of each medium was made up to 200 ml. The media were sterilized. After cooling, the media at the 5, 10, 20% sucrose levels were inoculated separately with C. butyricum, C. butyricum 6084, C. acetobutylicum NRRL B-527, C. pasteurianum NRRL B-598, C. butylicus NRRL B-592, and C. pasteurianum ATCC 6013. The cultures were incubated for 20 days at 35 degrees. For maximum butanol yield the 5% sucrose level was optimum for all the strains tested. At the 10% sucrose level great increase in sugar consumption occurred with C. butyricum Frolund, C. pasteurianum ATCC-6013, and C. butylicus IAL 15-152. Twice as much sucrose was consumed with C. acetobutylicum ATCC 6013, and NRRL B-572, and C. pasteurianum NRRL B-598. The increased sucrose consumption did not result in increased production of butanol or acetone. No acetone or butanol was formed with C. butyricum Frolund when the sucrose concentration was increased from 5 to 10%. With the increase in sucrose concentration, the formation of butanol and acetone decreased; acid formation was also inhibited.

Solubility and Standard Gibb's energies of transfer of alkali metal perchlorates, tetramethyl- and tetraethylammonium from water to aqua-acetone solvents

International Nuclear Information System (INIS)

Kireev, A.A.; Pak, T.G.; Bezuglyj, V.D.

1996-01-01

Solubilities of KClO 4 , RbClO 4 , CsClO 4 , (CH 3 ) 4 NClO 4 , (C 2 M 5 ) 4 NClO 4 in water and water-acetone mixtures are determined by the method of isothermal saturation at 298.15 K. Dissociation constants of alkali metal perchlorates are found by conductometric method. Solubility products and standard Gibbs energies of transfer of corresponding electrolytes from water into water-acetone solvents are calculated. The character of transfer Gibbs energy dependence on solvent composition is explained by preferred solvation of cations by acetone molecules and anions-by water molecules. Features of tetraalkyl ammonium ions are explained by large changes in energy of cavity formation for these ions

Working-up sugar-beet molasses in the acetone-butyl alcohol plants in Poland

Energy Technology Data Exchange (ETDEWEB)

Logotkin, I S; Zaritskii, I M

1959-01-01

The basic setup common to all Polish acetone and butanol plants is the addition of rye or wheat meal to the fermentation. A culture of Clostridium acetobutylicum, after spore formation, is mixed in a special apparatus with the meal, where it is kept for 18 hours at 37/sup 0/ and then treated with molasses; a culture is prepared which is used later in the fermentor. Independently a mixture of meal and molasses is mixed in an autoclave with H/sub 2/O, sterilized, and cooled. The resulting mash is mixed in the fermentor with the culture mentioned, where the fermentation liberates CO/sub 2/ and hydrogen which are recovered. The mixture is then heated, distilled, and rectified, where, in addition to slops, the desired products are obtained. The Polish plants figure that for each long ton of sugar contained in the molasses they recover butyl alcohol 178.0, acetone 83.7, and ethanol 7.3kg, and they use in addition to the molasses and bacilli cultures 58.4 tons of steam and 16 kg of NaOH long ton of the acetone-butyl alcohol mixture recovered.

Breath acetone as a potential marker in clinical practice.

Science.gov (United States)

Ruzsányi, Veronika; Péter Kalapos, Miklós

2017-06-01

In recent decades, two facts have changed the opinion of researchers about the function of acetone in humans. Firstly, it has turned out that acetone cannot be regarded as simply a waste product of metabolism, because there are several pathways in which acetone is produced or broken down. Secondly, methods have emerged making possible its detection in exhaled breath, thereby offering an attractive alternative to investigation of blood and urine samples. From a clinical point of view the measurement of breath acetone levels is important, but there are limitations to its wide application. These limitations can be divided into two classes, technical and biological limits. The technical limits include the storage of samples, detection threshold, standardization of clinical settings, and the price of instruments. When considering the biological ranges of acetone, personal factors such as race, age, gender, weight, food consumption, medication, illicit drugs, and even profession/class have to be taken into account to use concentration information for disorders. In some diseases such as diabetes mellitus and lung cancer, as well as in nutrition-related behavior such as starvation and ketogenic diet, breath acetone has been extensively examined. At the same time, there is a lack of investigations in other cases in which ketosis is also evident, such as in alcoholism or an inborn error of metabolism. In summary, the detection of acetone in exhaled breath is a useful and promising tool for diagnosis and it can be used as a marker to follow the effectiveness of treatments in some disorders. However, further endeavors are needed for clarification of the exact distribution of acetone in different body compartments and evaluation of its complex role in humans, especially in those cases in which a ketotic state also occurs.

Maximizing recovery of water-soluble proteins through acetone precipitation.

Science.gov (United States)

Crowell, Andrew M J; Wall, Mark J; Doucette, Alan A

2013-09-24

Solvent precipitation is commonly used to purify protein samples, as seen with the removal of sodium dodecyl sulfate through acetone precipitation. However, in its current practice, protein loss is believed to be an inevitable consequence of acetone precipitation. We herein provide an in depth characterization of protein recovery through acetone precipitation. In 80% acetone, the precipitation efficiency for six of 10 protein standards was poor (ca. ≤15%). Poor recovery was also observed for proteome extracts, including bacterial and mammalian cells. As shown in this work, increasing the ionic strength of the solution dramatically improves the precipitation efficiency of individual proteins, and proteome mixtures (ca. 80-100% yield). This is obtained by including 1-30 mM NaCl, together with acetone (50-80%) which maximizes protein precipitation efficiency. The amount of salt required to restore the recovery correlates with the amount of protein in the sample, as well as the intrinsic protein charge, and the dielectric strength of the solution. This synergistic approach to protein precipitation in acetone with salt is consistent with a model of ion pairing in organic solvent, and establishes an improved method to recover proteins and proteome mixtures in high yield. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of humus on acetone-butanol fermentations

Energy Technology Data Exchange (ETDEWEB)

Kovats, J

1963-01-01

Adding 6 to 8 g humus-rich soil dried at 80/sup 0/ to 100 cc sterilized molasses, containing 3.8 sucrose and 0.1% (NH/sub 4/)/sub 2/HPO/sub 4/, inoculated with acetone-butanol fermentative bacteria, increased acetone, butanol, and ethanol yields by 30, 50, and 40%, respectively. The acetone-to-butanol ratio increased from 1.85 to 2.1-2.3 in low and 2.6-2.8 in high sucrose-molasses concentrations. Yields of total organic solvents increased from 25 to 36-8% of the sucrose present. Inorganic salts from ashed humus soils were only 10 to 20% less effective in enhancing fermentation than the whole soil. It is postulated that the fermentation is enhanced by trace elements present in the soil.

Breath acetone concentration; biological variability and the influence of diet

International Nuclear Information System (INIS)

Španěl, Patrik; Dryahina, Kseniya; Rejšková, Alžběta; Chippendale, Thomas W E; Smith, David

2011-01-01

Previous measurements of acetone concentrations in the exhaled breath of healthy individuals and the small amount of comparable data for individuals suffering from diabetes are briefly reviewed as a prelude to the presentation of new data on the sporadic and wide variations of breath acetone that occur in ostensibly healthy individuals. Data are also presented which show that following a ketogenic diet taken by eight healthy individuals their breath acetone concentrations increased up to five times over the subsequent 6 h. Similarly, the breath acetone increased six and nine times when a low carbohydrate diet was taken by two volunteers and remained high for the several days for which the diet was continued. These new data, together with the previous data, clearly indicate that diet and natural intra-individual biological and diurnal variability result in wide variations in breath acetone concentration. This places an uncertainty in the use of breath acetone alone to monitor blood glucose and glycaemic control, except and unless the individual acts as their own control and is cognizant of the need for dietary control. (note)

Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

Science.gov (United States)

Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

2016-01-01

Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions. © 2016 S. Karger AG, Basel.

The effects of inhaled acetone on place conditioning in adolescent rats.

Science.gov (United States)

Lee, Dianne E; Pai, Jennifer; Mullapudui, Uma; Alexoff, David L; Ferrieri, Richard; Dewey, Stephen L

2008-03-01

Acetone is an ubiquitous ingredient in many household products (e.g., glue solvents, air fresheners, adhesives, nail polish, and paint) that is putatively abused; however, there is little empirical evidence to suggest that acetone alone has any abuse liability. Therefore, we systematically investigated the conditioned response to inhaled acetone in a place conditioning apparatus. Three groups of male, Sprague-Dawley rats were exposed to acetone concentrations of 5000, 10,000 or 20,000 ppm for 1 h in a conditioned place preference apparatus alternating with air for 6 pairing sessions. A place preference test ensued in an acetone-free environment. To test the preference of acetone as a function of pairings sessions, the 10,000 ppm group received an additional 6 pairings and an additional group received 3 pairings. The control group received air in both compartments. Locomotor activity was recorded by infrared photocells during each pairing session. We noted a dose response relationship to acetone at levels 5000-20,000 ppm. However, there was no correlation of place preference as a function of pairing sessions at the 10,000 ppm level. Locomotor activity was markedly decreased in animals on acetone-paired days as compared to air-paired days. The acetone concentrations we tested for these experiments produced a markedly decreased locomotor activity profile that resemble CNS depressants. Furthermore, a dose response relationship was observed at these pharmacologically active concentrations, however, animals did not exhibit a positive place preference.

The effects of inhaled acetone on place conditioning in adolescent rats

Science.gov (United States)

Lee, Dianne E.; Pai, Jennifer; Mullapudui, Uma; Alexoff, David L.; Ferrieri, Richard; Dewey, Stephen L.

2009-01-01

Introduction Acetone is a ubiquitous ingredient in many household products (e.g., glue solvents, air fresheners, adhesives, nail polish, and paint) that is putatively abused; however, there is little empirical evidence to suggest that acetone alone has any abuse liability. Therefore, we systematically investigated the conditioned response to inhaled acetone in a place conditioning apparatus. Method Three groups of male, Sprague-Dawley rats were exposed to acetone concentrations of 5,000, 10,000 or 20,000 ppm for 1 hour in a conditioned place preference apparatus alternating with air for 6 pairing sessions. A place preference test ensued in an acetone-free environment. To test the preference of acetone as a function of pairings sessions, the 10,000 ppm group received an additional 6 pairings and an additional group received 3 pairings. The control group received air in both compartments. Locomotor activity was recorded by infrared photocells during each pairing session. Results We noted a dose response relationship to acetone at levels 5,000-20,000 ppm. However, there was no correlation of place preference as a function of pairing sessions at the 10,000 ppm level. Locomotor activity was markedly decreased in animals on acetone-paired days as compared to air-paired days. Conclusion The acetone concentrations we tested for these experiments produced a markedly decreased locomotor activity profile that resemble CNS depressants. Furthermore, a dose response relationship was observed at these pharmacologically active concentrations, however, animals did not exhibit a positive place preference. PMID:18096214

Influence of concentration of sucrose on the acetone-butanol fermentation by different strains of Clostridium

Energy Technology Data Exchange (ETDEWEB)

Bahadur, K; Saroj, K K

1959-01-01

To culture media containing (NH/sub 4/)/sub 2/SO/sub 4/ (0.34 g) and MgSO/sub 4/ (0.16 g), were added 5, 10, and 20% sucrose, respectively; the pH was adjusted to 6.4 with KH/sub 2/PO/sub 4/-NaOH buffer; the volume of each medium was made up to 200 ml. The media were sterilized. After cooling, the media at the 5, 10, 20% sucrose levels were inoculated separately with C. butyricum, C. butyricum 6084, C. acetobutylicum NRRL B-527, C. pasteurianum NRRL B-598, C. butylicus NRRL B-592, nd C. pasteurianum ATCC 6013. The cultures were incubated for 20 days at 35/sup 0/. For maximum BuOH yield the 5% sucrose level was optimum for all the strains tested. At the 10% sucrose level great increase in sugar consumption occurred with C. butyricum Frolund, C. pasteurianum ATCC-6013, and C. butylicus IAL 15-152. Twice as much sucrose was consumed with C. acetobutylicum ATCC 10132, and NRRL B-572, and C. pasteurianum NRRL B-598. The increased sucrose consumption did not result in increased production of BuOH or acetone. No acetone or BuOH was formed with C. butyricum Frolund when the sucrose concentration was increased from 5 to 10%. With the increase in sucrose concentration, the formation of BuH and acetone decreased; acid formation was also inhibited.

Acetone improves the topographical homogeneity of liquid phase exfoliated few-layer black phosphorus flakes.

Science.gov (United States)

Gomez Perez, Juan; Konya, Zoltan; Kukovecz, Akos

2018-06-12

Liquid phase exfoliation of 2D materials has issues related to the sorption of the solvent, the oxidation of the sample during storage, and the topographical inhomogeneity of the exfoliated material. N-methyl-2-pyrrolidone (NMP), a common solvent for black phosphorus (BP) exfoliation, has additional drawbacks like the formation of by-products during sonication and poor solvent volatility. Here we demonstrate an improvement in the topographical homogeneity (i.e. thickness and lateral dimensions) of NMP-exfoliated BP flakes after resuspension in acetone. The typical size of monolayers and bilayers stabilised in acetone was 99.8±27.4 nm and 159.1±57 nm, respectively. These standard deviations represent a threefold improvement over those of the NMP-exfoliated originals. Phosphorene can also be exfoliated directly in acetone by very long ultrasonication. The product suspension enjoys the same dimensional homogeneity benefits, which confirms that this effect is an intrinsic property of the acetone-BP system. The quality and stability of the exfoliated flakes was checked by XRD, TEM, electron diffraction and Raman spectroscopy. Thermal expansion coefficients of the A1g, B2g and A2g Raman modes were calculated for drop-casted samples as -0.01828 cm-1/K, -0.03056 cm-1/K and -0.03219 cm-1/K, respectively. The flakes withstand 20 minutes in O2 flow at 373 K without lattice distortion. . © 2018 IOP Publishing Ltd.

[Adsorption characteristics of acetone and butanone onto honeycomb ZSM-5 molecular sieve].

Science.gov (United States)

Du, Juan; Luan, Zhi-Qiang; Xie, Qiang; Ye, Ping-Wei; Li, Kai; Wang, Xi-Qin

2013-12-01

Adsorption capacity of acetone and acetone-butanone mixture onto honeycomb ZSM-5 molecular sieve was measured in this paper, and the influences of relative humidity, initial adsorbate concentration and airflow velocity on the adsorption process were investigated. Besides, adsorption performance parameters were calculated by Wheeler's equation. The results showed that relative humidity had no obvious influence on the acetone adsorption performance, which suggests that this material has good hydrophobic ability; in the low concentration range, the dynamic saturated adsorption capacity of acetone increased with the increase of initial concentration, but in the occasion of high concentration of acetone gas (more than 9 mg x L(-1)), the dynamic saturated adsorption capacity maintained at a certain level and did not vary with the increase of initial concentration; the increase of air flow velocity resulted in significant increase of acetone adsorption rate constant, at the same time the critical layer thickness of the adsorbent bed also increased significantly. In the cases of acetone-butanone mixture, the adsorption capacity of butanone onto ZSM-5 was clearly higher than that of acetone.

Acetone in theGlobal Troposphere: Its Possible Role as a Global Source of PAN

Science.gov (United States)

Singh, H. B.; Kanakidou, M.

1994-01-01

Oxygenated hydrocarbons are thought to be important components of the atmosphere but, with the exception of formaldehyde, very little about their distribution and fate is known. Aircraft measurements of acetone (CH3COCH3), PAN (CH3CO3NO2) and other organic species (e. g. acetaldehyde, methanol and ethanol) have been performed over the Pacific, the southern Atlantic, and the subarctic atmospheres. Sampled areas extended from 0 to 12 km altitude over latitudes of 70 deg N to 40 deg S. All measurements are based on real time in-situ analysis of cryogenically preconcentrated air samples. Substantial concentrations of these oxygenated species (10-2000 ppt) have been observed at all altitudes and geographical locations in the troposphere. Important sources include, emissions from biomass burning, plant and vegetation, secondary oxidation of primary non-methane hydrocarbons, and man-made emissions. Direct measurements within smoke plumes have been used to estimate the biomass burning source. Photochemistry studies are used to suggest that acetone could provide a major source of peroxyacetyl radicals in the atmosphere and play an important role in sequestering reactive nitrogen. Model calculations show that acetone photolysis contributes significantly to PAN formation in the middle and upper troposphere.

Purification and characterization of acetone carboxylase from Xanthobacter strain Py2

OpenAIRE

Sluis, Miriam K.; Ensign, Scott A.

1997-01-01

Acetone metabolism in the aerobic bacterium Xanthobacter strain Py2 proceeds by a carboxylation reaction forming acetoacetate as the first detectable product. In this study, acetone carboxylase, the enzyme catalyzing this reaction, has been purified to homogeneity and characterized. Acetone carboxylase was comprised of three polypeptides with molecular weights of 85,300, 78,300, and 19,600 arranged in an α2β2γ2 quaternary structure. The carboxylation of acetone was coupled to the hydrolysis o...

trans-Carbonylchloridobis(tri-p-tolylphosphinerhodium(I acetone solvate

Directory of Open Access Journals (Sweden)

Brian R. James

2008-03-01

Full Text Available The title compound, [RhCl(C21H21P2(CO]·C3H6O, was precipitated in trace yield from a reaction of RhCl(cod(THP with P(p-tol3 in a 1:1 acetone-d6/CD3OD solution under a hydrogen atmosphere [p-tol = p-tolyl, THP = tris(hydroxymethylphosphine, P(CH2OH3, and cod = 1,5-cyclooctadiene]. The complex displays a square-planar geometry around the RhI atom. The complex molecules and the acetone molecules are linked into a chain along the a axis by intermolecular C—H...Cl and C—H...O hydrogen bonds.

Acetone and Water on TiO(110): H/D Exchange

International Nuclear Information System (INIS)

Henderson, Michael A.

2005-01-01

Isotopic H/D exchange between coadsorbed acetone and water on the TiO(110) surface was examined using temperature programmed desorption (TPD) as a function of coverage and two surface pretreatments (oxidation and reduction). Coadsorbed acetone and water interact repulsively on reduced TiO(110) based on results from the companion paper to this study, with water exerting a greater influence in destabilizing acetone and acetone having only a nominal influence on water. Despite the repulsive interaction between these coadsorbates, about 0.02 ML of a 1 ML d6-acetone on the reduced surface exhibits H/D exchange with coadsorbed water, with the exchange occurring exclusively in the high temperature region of the d?-acetone TPD spectrum at ∼340 K. The effect was confirmed with combinations of d?-acetone and D?O. The extent of exchange decreased on the reduced surface with water coverages above ∼0.3 ML due to the ability of water to displace coadsorbed acetone from first layer sites to the multilayer. In contrast, the extent of exchange increased by a factor of 3 when the surface was pre-oxidized prior to coadsorption. In this case, there was no evidence for the negative influence of high water coverages on the extent of H/D exchange. Comparison of the TPD spectra from the exchange products (either d?- or d?-acetone depending on the coadsorption pairing) suggests that, in addition to the 340 K exchange process seen on the reduced surface, a second exchange process was observed on the oxidized surface at ∼390 K. In both cases (oxidized and reduced), desorption of the H/D exchange products appeared to be reaction limited and to involve the influence of OH/OD groups (or water formed during recombinative desorption of OH/OD groups) instead of molecularly adsorbed water. The 340 K exchange process is assigned to reaction at step sites and the 390 K exchange process is attributed to the influence of oxygen adatoms deposited during surface oxidation. The H/D exchange

Impacts of heterogeneous reactions to atmospheric peroxides: Observations and budget analysis study

Science.gov (United States)

Qin, Mengru; Chen, Zhongming; Shen, Hengqing; Li, Huan; Wu, Huihui; Wang, Yin

2018-06-01

Atmospheric peroxides play important roles in atmospheric chemistry, acting as reactive oxidants and reservoirs of HOX and ROX radicals. Field measurements of atmospheric peroxides were conducted over urban Beijing from 2015 to 2016, including dust storm days, haze days and different seasons. We employed a box model based on RACM2 mechanism to conduct concentration simulation and budget analysis of hydrogen peroxide (H2O2) and peroxyacetic acid (PAA). In this study, heterogeneous reaction is found to be a significant sink for atmospheric H2O2 and PAA in urban Beijing. Here, we recommend a suitable uptake coefficient formula considering the water effect for model research of peroxides. It is found that H2O2 and PAA unexpectedly maintained considerable concentrations on haze days, even higher than that on non-haze days. This phenomenon is mainly ascribed to relatively high levels of volatile organic compounds and ozone on haze days. In addition, high levels of water vapor in pollution episode can promote not only the heterogeneous uptake to aerosol phase but also the production of H2O2. Atmospheric PAA formation is suggested to be sensitive to alkenes and NOX in urban Beijing. In particular, with the help of peroxides, sulfate formation rate from heterogeneous uptake could increase by ∼4 times on haze days, indicating the potential effect of peroxides on enhancement of aerosol oxidative property and secondary sulfate formation.

Apparatus and method for monitoring breath acetone and diabetic diagnostics

Science.gov (United States)

Duan, Yixiang [Los Alamos, NM; Cao, Wenqing [Los Alamos, NM

2008-08-26

An apparatus and method for monitoring diabetes through breath acetone detection and quantitation employs a microplasma source in combination with a spectrometer. The microplasma source provides sufficient energy to produce excited acetone fragments from the breath gas that emit light. The emitted light is sent to the spectrometer, which generates an emission spectrum that is used to detect and quantify acetone in the breath gas.

An engineered non-oxidative glycolysis pathway for acetone production in Escherichia coli.

Science.gov (United States)

Yang, Xiaoyan; Yuan, Qianqian; Zheng, Yangyang; Ma, Hongwu; Chen, Tao; Zhao, Xueming

2016-08-01

To find new metabolic engineering strategies to improve the yield of acetone in Escherichia coli. Results of flux balance analysis from a modified Escherichia coli genome-scale metabolic network suggested that the introduction of a non-oxidative glycolysis (NOG) pathway would improve the theoretical acetone yield from 1 to 1.5 mol acetone/mol glucose. By inserting the fxpk gene encoding phosphoketolase from Bifidobacterium adolescentis into the genome, we constructed a NOG pathway in E.coli. The resulting strain produced 47 mM acetone from glucose under aerobic conditions in shake-flasks. The yield of acetone was improved from 0.38 to 0.47 mol acetone/mol glucose which is a significant over the parent strain. Guided by computational analysis of metabolic networks, we introduced a NOG pathway into E. coli and increased the yield of acetone, which demonstrates the importance of modeling analysis for the novel metabolic engineering strategies.

Investigation of hybrid plasma-catalytic removal of acetone over CuO/γ-Al2O3 catalysts using response surface method.

Science.gov (United States)

Zhu, Xinbo; Tu, Xin; Mei, Danhua; Zheng, Chenghang; Zhou, Jinsong; Gao, Xiang; Luo, Zhongyang; Ni, Mingjiang; Cen, Kefa

2016-07-01

In this work, plasma-catalytic removal of low concentrations of acetone over CuO/γ-Al2O3 catalysts was carried out in a cylindrical dielectric barrier discharge (DBD) reactor. The combination of plasma and the CuO/γ-Al2O3 catalysts significantly enhanced the removal efficiency of acetone compared to the plasma process using the pure γ-Al2O3 support, with the 5.0 wt% CuO/γ-Al2O3 catalyst exhibiting the best acetone removal efficiency of 67.9%. Catalyst characterization was carried out to understand the effect the catalyst properties had on the activity of the CuO/γ-Al2O3 catalysts in the plasma-catalytic reaction. The results indicated that the formation of surface oxygen species on the surface of the catalysts was crucial for the oxidation of acetone in the plasma-catalytic reaction. The effects that various operating parameters (discharge power, flow rate and initial concentration of acetone) and the interactions between these parameters had on the performance of the plasma-catalytic removal of acetone over the 5.0 wt% CuO/γ-Al2O3 catalyst were investigated using central composite design (CCD). The significance of the independent variables and their interactions were evaluated by means of the Analysis of Variance (ANOVA). The results showed that the gas flow rate was the most significant factor affecting the removal efficiency of acetone, whilst the initial concentration of acetone played the most important role in determining the energy efficiency of the plasma-catalytic process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Breath acetone monitoring by portable Si:WO3 gas sensors

International Nuclear Information System (INIS)

Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E.

2012-01-01

Highlights: ► Portable sensors were developed and tested for monitoring acetone in the human breath. ► Acetone concentrations down to 20 ppb were measured with short response times ( 3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (∼20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques.

Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

OpenAIRE

Akgul Kalkan, Esin; Sahiner, Mehtap; Ulker Cakir, Dilek; Alpaslan, Duygu; Yilmaz, Selehattin

2016-01-01

Using high-performance liquid chromatography (HPLC) and 2,4-dinitrophenylhydrazine (2,4-DNPH) as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365?nm using an ultraviolet-visible (UV-Vis) diode array detector (DAD). For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15?cm ? 4.6?mm ? 3??m) at retention time (t R) ...

Synthesis of Covalently Cross-Linked Colloidosomes from Peroxidized Pickering Emulsions

Directory of Open Access Journals (Sweden)

Nadiya Popadyuk

2016-10-01

Full Text Available A new approach to the formation of cross-linked colloidosomes was developed on the basis of Pickering emulsions that were stabilized exclusively by peroxidized colloidal particles. Free radical polymerization and a soft template technique were used to convert droplets of a Pickering emulsion into colloidosomes. The peroxidized latex particles were synthesized in the emulsion polymerization process using amphiphilic polyperoxide copolymers poly(2-tert-butylperoxy-2-methyl-5-hexen-3-ine-co-maleic acid (PM-1-MAc or poly[N-(tert-butylperoxymethylacrylamide]-co-maleic acid (PM-2-MAc, which were applied as both initiators and surfactants (inisurfs. The polymerization in the presence of the inisurfs results in latexes with a controllable amount of peroxide and carboxyl groups at the particle surface. Peroxidized polystyrene latex particles with a covalently grafted layer of inisurf PM-1-MAc or PM-2-MAc were used as Pickering stabilizers to form Pickering emulsions. A mixture of styrene and/or butyl acrylate with divinylbenzene and hexadecane was applied as a template for the synthesis of colloidosomes. Peroxidized latex particles located at the interface are involved in the radical reactions of colloidosomes formation. As a result, covalently cross-linked colloidosomes were obtained. It was demonstrated that the structure of the synthesized (using peroxidized latex particles colloidosomes depends on the amount of functional groups and pH during the synthesis. Therefore, the size and morphology of colloidosomes can be controlled by latex particle surface properties.

Membrane lipid peroxidation by UV-A: Mechanism and implications

International Nuclear Information System (INIS)

Bose, B.; Agarwal, S.; Chatterjee, S.N.

1990-01-01

UV-A produced a dose-dependent linear increase of lipid peroxidation in liposomal membrane, as detected by the assay of (i) conjugated dienes, (ii) lipid hydroperoxides, (iii) malondialdehydes (MDA), and (iv) the fluorescent adducts formed by the reaction of MDA with glycine and also a linear dose-dependent increase of [ 14 C]glucose efflux from the liposomes. UV-A-induced MDA production could not be inhibited by any significant degree by sodium formate, dimethyl sulfoxide, EDTA, or superoxide dismutase but was very significantly inhibited by butylated hydroxytoluene, alpha-tocopherol, sodium azide, L-histidine, dimethylfuran, and beta-carotene. MDA formation increased with an increase in the D 2 O content in water, leading to a maximal amount of nearly 50% enhancement of lipid peroxidation in 100% D 2 O vis-a-vis water used as dispersion medium. The experimental findings indicate the involvement of singlet oxygen as the initiator of the UV-A-induced lipid peroxidation

A cross-sectional study of breath acetone based on diabetic metabolic disorders.

Science.gov (United States)

Li, Wenwen; Liu, Yong; Lu, Xiaoyong; Huang, Yanping; Liu, Yu; Cheng, Shouquan; Duan, Yixiang

2015-02-26

Breath acetone is a known biomarker for diabetes mellitus in breath analysis. In this work, a cross-sectional study of breath acetone based on clinical metabolic disorders of type 2 diabetes mellitus (T2DM) was carried out. Breath acetone concentrations of 113 T2DM patients and 56 apparently healthy individuals were measured at a single time point. Concentrations varied from 0.22 to 9.41 ppmv (mean 1.75 ppmv) for T2DM, which were significantly higher than those for normal controls (ranged from 0.32 to 1.96 ppmv, mean 0.72 ppmv, p = 0.008). Observations in our work revealed that breath acetone concentrations elevated to different degrees, along with the abnormality of blood glucose, glycated hemoglobin (HbA1c), triglyceride and cholesterol. Breath acetone showed obviously positive correlations with blood ketone and urine ketone. Possible metabolic relations between breath acetone and diabetic disorders were also discussed. This work aimed at giving an overall assessment of breath acetone from the perspective of clinical parameters for type 2 diabetes.

Removal of fermentation inhibitors from alkaline peroxide pretreated and enzymatically hydrolyzed wheat straw: Production of butanol from hydrolysate using Clostridium beijerinckii in batch reactors

International Nuclear Information System (INIS)

Qureshi, Nasib; Saha, Badal C.; Hector, Ronald E.; Cotta, Michael A.

2008-01-01

In these studies, alkaline peroxide pretreatment of wheat straw was investigated. Pretreated wheat straw was hydrolyzed using cellulolytic and xylanolytic enzymes, and the hydrolysate was used to produce butanol using Clostridium beijerinckii P260. The culture produced less than 2.59 g L -1 acetone-butanol-ethanol (ABE) from alkaline peroxide wheat straw hydrolysate (APWSH) that had not been treated to reduce salt concentration (a neutralization product). However, fermentation was successful after inhibitors (salts) were removed from the hydrolysate by electrodialysis. A control glucose fermentation resulted in the production of 21.37 g L -1 ABE, while salt removed APWSH resulted in the production of 22.17 g L -1 ABE. In the two fermentations, reactor productivities were 0.30 and 0.55 g L -1 h -1 , respectively. A comparison of use of different substrates (corn fiber, wheat straw) and different pretreatment techniques (dilute sulfuric acid, alkaline peroxide) suggests that generation of inhibitors is substrate and pretreatment specific

A Highly Sensitive Chemiluminometric Assay for Real-Time Detection of Biological Hydrogen Peroxide Formation.

Science.gov (United States)

Zhu, Hong; Jia, Zhenquan; Trush, Michael A; Li, Y Robert

2016-05-01

Hydrogen peroxide (H 2 O 2 ) is a major reactive oxygen species (ROS) produced by various cellular sources, especially mitochondria. At high levels, H 2 O 2 causes oxidative stress, leading to cell injury, whereas at low concentrations, this ROS acts as an important second messenger to participate in cellular redox signaling. Detection and measurement of the levels or rates of production of cellular H 2 O 2 are instrumental in studying the biological effects of this major ROS. While a number of assays have been developed over the past decades for detecting and/or quantifying biological H 2 O 2 formation, none has been shown to be perfect. Perhaps there is no perfect assay for sensitively and accurately quantifying H 2 O 2 as well as other ROS in cells, wherein numerous potential reactants are present to interfere with the reliable measurement of the specific ROS. In this context, each assay has its own advantages and intrinsic limitations. This article describes a highly sensitive assay for real-time detection of H 2 O 2 formation in cultured cells and isolated mitochondria. This assay is based on the luminol/horseradish peroxidase-dependent chemiluminescence that is inhibitable by catalase. The article discusses the usefulness and shortcomings of this chemiluminometric assay in detecting biological H 2 O 2 formation induced by beta-lapachone redox cycling with both cells and isolated mitochondria.

Proteomic analysis of nitrate-dependent acetone degradation by Alicycliphilus denitrificans strain BC

NARCIS (Netherlands)

Oosterkamp, M.J.; Boeren, S.; Atashgahi, S.; Plugge, C.M.; Schaap, P.J.; Stams, A.J.M.

2015-01-01

Alicycliphilus denitrificans strain BC grows anaerobically on acetone with nitrate as electron acceptor. Comparative proteomics of cultures of A. denitrificans strain BC grown on either acetone or acetate with nitrate was performed to study the enzymes involved in the acetone degradation pathway. In

Catalytic function of the mycobacterial binuclear iron monooxygenase in acetone metabolism.

Science.gov (United States)

Furuya, Toshiki; Nakao, Tomomi; Kino, Kuniki

2015-10-01

Mycobacteria such as Mycobacterium smegmatis strain mc(2)155 and Mycobacterium goodii strain 12523 are able to grow on acetone and use it as a source of carbon and energy. We previously demonstrated by gene deletion analysis that the mimABCD gene cluster, which encodes a binuclear iron monooxygenase, plays an essential role in acetone metabolism in these mycobacteria. In the present study, we determined the catalytic function of MimABCD in acetone metabolism. Whole-cell assays were performed using Escherichia coli cells expressing the MimABCD complex. When the recombinant E. coli cells were incubated with acetone, a product was detected by gas chromatography (GC) analysis. Based on the retention time and the gas chromatography-mass spectrometry (GC-MS) spectrum, the reaction product was identified as acetol (hydroxyacetone). The recombinant E. coli cells produced 1.02 mM of acetol from acetone within 24 h. Furthermore, we demonstrated that MimABCD also was able to convert methylethylketone (2-butanone) to 1-hydroxy-2-butanone. Although it has long been known that microorganisms such as mycobacteria metabolize acetone via acetol, this study provides the first biochemical evidence for the existence of a microbial enzyme that catalyses the conversion of acetone to acetol. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Adsorption and Reaction of Acetone over CeOX(111) Thin Films

International Nuclear Information System (INIS)

Mullins, David R.; Senanayake, Sanjaya D.; Gordon, Wesley O.; Overbury, Steven H.

2009-01-01

This study reports the interaction of acetone (CH3COCH3), the simplest ketone, with well ordered CeO2(111) thin film surfaces. The fully oxidized CeO2(111) surface shows a weak interaction with acetone with the sole desorption product (TPD) being acetone at 210 K. The chemisorbed molecule binds to the surface as the ?1-acetone species rather than through a bridge-bonded dioxy-configuration. Exposure of a CeO2(111) surface to acetone at 600K removes oxygen as CO and results in the conversion of Ce4+ to Ce3+. Acetone chemisorbs strongly on reduced CeO2-x(111) with molecular acetone desorbing near 500 K. Decomposition also occurs with H2 desorbing between 450 and 600 K and C reacting with O in the ceria to desorb above 650 K. A stable species exists from 200 to 500 K on the reduced surface that has three unique types of C. High resolution C 1s XPS spectra indicate these are Ce-CH2, C-CH3 and C-O species. C k-edge NEXAFS indicates the presence of C(double b ond)C and C(double b ond)O bonds. It is postulated that the intermediate is a carbanion bonded through both O and C atoms to Ce cations.

Delayed fluorescence of meso-tetraphenylporphyrin in acetone and in dimethylsulphoxide

International Nuclear Information System (INIS)

Korinek, M.; Klinger, P.; Dedic, R.; Psencik, J.; Svoboda, A.; Hala, J.

2007-01-01

Photodynamic therapy is based on photosensitisation of singlet oxygen by porphyrin-like molecules. We have performed a systematic study of delayed fluorescence of tetraphenylporphyrin in acetone (used as a spectroscopic standard) and in dimethylsulphoxide (clinically used solvent) to obtain spectra, kinetics, and quantum yields, including their dependencies on tetraphenylporphyrin concentration. In dimethylsulphoxide the repopulation of excited singlets and subsequent delayed fluorescence is caused by triplet-triplet quenching with rate constant of (2.2±1.0)x10 9 l mol -1 s -1 . However, repopulation of excited singlets in acetone is also caused by singlet oxygen reaction with triplet tetraphenylporphyrin causing monoexponential delayed fluorescence decay with the lifetime 0.3 μs. Due to much lower viscosity of acetone compared to dimethylsulphoxide, triplet-triplet quenching constant in acetone is much higher (1.7±0.7)x10 10 l mol -1 s -1 . The rate constant for the reaction of singlet oxygen with triplet of tetraphenylporphyrin is (2.0±0.8)x10 10 l mol -1 s -1 in acetone

Investigation of toxic effects of imidazolium ionic liquids, [bmim][BF{sub 4}] and [omim][BF{sub 4}], on marine mussel Mytilus galloprovincialis with or without the presence of conventional solvents, such as acetone

Energy Technology Data Exchange (ETDEWEB)

Tsarpali, Vasiliki; Belavgeni, Alexia; Dailianis, Stefanos, E-mail: sdailianis@upatras.gr

2015-07-15

Highlights: • The toxic effects of [bmim][BF{sub 4}] and [omim][BF{sub 4}] on mussels were investigated. • Both ILs could induce lethal and nonlethal effects on Mytilus galloprovincialis. • Different extent of IL-mediated adverse effects was observed in mussel hemocytes. • The alkyl chain length and lipophilicity of ILs are crucial for their toxicity. • Acetone influences the oxidative and genotoxic effects of [omim][BF{sub 4}]. - Abstract: This study investigated the cytotoxic, oxidative and genotoxic effects of two commonly used imidazolium ionic liquids (ILs), [bmim][BF{sub 4}] (1-butyl-3-methylimidazolium) and [omim][BF{sub 4}] (1-methyl-3-octylimidazolium tetrafluoroborate), on the marine mussel Mytilus galloprovincialis, as well as whether acetone could mediate their toxic profile. In this context, mussels were firstly exposed to different concentrations of [bmim][BF{sub 4}] or [omim][BF{sub 4}], with or without the presence of acetone (at a final concentration of 0.06% v/v), for a period of 96 h, in order to determine the concentration that causes 50% mussel mortality (LC{sub 50} values) in each case. Thereafter, mussels were exposed to sub- and non-lethal concentrations of ILs for investigating their ability to cause lysosomal membrane impairment (with the use of neutral red retention assay/NRRT), superoxide anion and lipid peroxidation byproduct (malondialdehyde/MDA) formation, as well as DNA damage and formation of nuclear abnormalities in hemocytes. The results showed that [omim][BF{sub 4}] was more toxic than [bmim][BF{sub 4}] in all cases, while the presence of acetone resulted in a slight attenuation of its toxicity. The different toxic behavior of ILs was further revealed by the significantly lower levels of NRRT values observed in [omim][BF{sub 4}]-treated mussels, compared to those occurring in [bmim][BF{sub 4}] in all cases. Similarly, [bmim][BF{sub 4}]-mediated oxidative and genotoxic effects were observed only in the highest

Five Decades with Polyunsaturated Fatty Acids: Chemical Synthesis, Enzymatic Formation, Lipid Peroxidation and Its Biological Effects

Directory of Open Access Journals (Sweden)

Angel Catalá

2013-01-01

Full Text Available I have been involved in research on polyunsaturated fatty acids since 1964 and this review is intended to cover some of the most important aspects of this work. Polyunsaturated fatty acids have followed me during my whole scientific career and I have published a number of studies concerned with different aspects of them such as chemical synthesis, enzymatic formation, metabolism, transport, physical, chemical, and catalytic properties of a reconstructed desaturase system in liposomes, lipid peroxidation, and their effects. The first project I became involved in was the organic synthesis of [1-14C] eicosa-11,14-dienoic acid, with the aim of demonstrating the participation of that compound as a possible intermediary in the biosynthesis of arachidonic acid “in vivo.” From 1966 to 1982, I was involved in several projects that study the metabolism of polyunsaturated fatty acids. In the eighties, we studied fatty acid binding protein. From 1990 up to now, our laboratory has been interested in the lipid peroxidation of biological membranes from various tissues and different species as well as liposomes prepared with phospholipids rich in PUFAs. We tested the effect of many antioxidants such as alpha tocopherol, vitamin A, melatonin and its structural analogues, and conjugated linoleic acid, among others.

The effect of ionizing radiation on the fatty acid composition of natural fats and on lipid peroxide formation

International Nuclear Information System (INIS)

Hammer, C.T.; Wills, E.D.

1979-01-01

The effects of irradiation doses of 200 to 1000 krad on the fatty acid composition of saturated and unsaturated natural food fats have been studied. Lard, coconut oil, corn oil, methyl linoleate and herring oil have been analysed before and after irradiation for lipid peroxide content and fatty acid composition. The effects of storage under varied conditions after irradiation have also been investigated. Irradiation doses of 200 to 1000 krad had little effect on the fatty acid compositions of saturated fats (lard and coconut oil) or of fats with a high antioxidant content (corn oil) but caused destruction of 98 per cent of the highly unsaturated acids (18:4, 20:5, 22:6) and 46 per cent of the diene acids (18:2) in herring oil. The destruction of the polyunsaturated fatty acids increased with increasing storage temperature and storage time. The destruction of polyunsaturated fatty acids was accompanied by an increase in lipid peroxide formation. It is considered that changes in fatty acid composition in natural foods after irradiation are important in consideration of the use of irradiation of food preservation. (author)

Novel Acetone Metabolism in a Propane-Utilizing Bacterium, Gordonia sp. Strain TY-5▿

Science.gov (United States)

Kotani, Tetsuya; Yurimoto, Hiroya; Kato, Nobuo; Sakai, Yasuyoshi

2007-01-01

In the propane-utilizing bacterium Gordonia sp. strain TY-5, propane was shown to be oxidized to 2-propanol and then further oxidized to acetone. In this study, the subsequent metabolism of acetone was studied. Acetone-induced proteins were found in extracts of cells induced by acetone, and a gene cluster designated acmAB was cloned on the basis of the N-terminal amino acid sequences of acetone-induced proteins. The acmA and acmB genes encode a Baeyer-Villiger monooxygenase (BVMO) and esterase, respectively. The BVMO encoded by acmA was purified from acetone-induced cells of Gordonia sp. strain TY-5 and characterized. The BVMO exhibited NADPH-dependent oxidation activity for linear ketones (C3 to C10) and cyclic ketones (C4 to C8). Escherichia coli expressing the acmA gene oxidized acetone to methyl acetate, and E. coli expressing the acmB gene hydrolyzed methyl acetate. Northern blot analyses revealed that polycistronic transcription of the acmAB gene cluster was induced by propane, 2-propanol, and acetone. These results indicate that the acmAB gene products play an important role in the metabolism of acetone derived from propane oxidation and clarify the propane metabolism pathway of strain TY-5 (propane → 2-propanol → acetone → methyl acetate → acetic acid + methanol). This paper provides the first evidence for BVMO-dependent acetone metabolism. PMID:17071761

Protein precipitation of diluted samples in SDS-containing buffer with acetone leads to higher protein recovery and reproducibility in comparison with TCA/acetone approach.

Science.gov (United States)

Santa, Cátia; Anjo, Sandra I; Manadas, Bruno

2016-07-01

Proteomic approaches are extremely valuable in many fields of research, where mass spectrometry methods have gained an increasing interest, especially because of the ability to perform quantitative analysis. Nonetheless, sample preparation prior to mass spectrometry analysis is of the utmost importance. In this work, two protein precipitation approaches, widely used for cleaning and concentrating protein samples, were tested and compared in very diluted samples solubilized in a strong buffer (containing SDS). The amount of protein recovered after acetone and TCA/acetone precipitation was assessed, as well as the protein identification and relative quantification by SWATH-MS yields were compared with the results from the same sample without precipitation. From this study, it was possible to conclude that in the case of diluted samples in denaturing buffers, the use of cold acetone as precipitation protocol is more favourable than the use of TCA/acetone in terms of reproducibility in protein recovery and number of identified and quantified proteins. Furthermore, the reproducibility in relative quantification of the proteins is even higher in samples precipitated with acetone compared with the original sample. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

O⁶-carboxymethylguanine DNA adduct formation and lipid peroxidation upon in vitro gastrointestinal digestion of haem-rich meat.

Science.gov (United States)

Vanden Bussche, Julie; Hemeryck, Lieselot Y; Van Hecke, Thomas; Kuhnle, Gunter G C; Pasmans, Frank; Moore, Sharon A; Van de Wiele, Tom; De Smet, Stefaan; Vanhaecke, Lynn

2014-09-01

Epidemiological and clinical studies have demonstrated that the consumption of red haem-rich meat may contribute to the risk of colorectal cancer. Two hypotheses have been put forward to explain this causal relationship, i.e. N-nitroso compound (NOC) formation and lipid peroxidation (LPO). In this study, the NOC-derived DNA adduct O(6)-carboxymethylguanine (O(6)-CMG) and the LPO product malondialdehyde (MDA) were measured in individual in vitro gastrointestinal digestions of meat types varying in haem content (beef, pork, chicken). While MDA formation peaked during the in vitro small intestinal digestion, alkylation and concomitant DNA adduct formation was observed in seven (out of 15) individual colonic digestions using separate faecal inocula. From those, two haem-rich meat digestions demonstrated a significantly higher O(6)-CMG formation (p meat. The addition of myoglobin, a haem-containing protein, to the digestive simulation showed a dose-response association with O(6)-CMG (p = 0.004) and MDA (p = 0.008) formation. The results suggest the haem-iron involvement for both the LPO and NOC pathway during meat digestion. Moreover, results unambiguously demonstrate that DNA adduct formation is very prone to inter-individual variation, suggesting a person-dependent susceptibility to colorectal cancer development following haem-rich meat consumption. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antibacterial Activities and Mechanism of Action of Acetone Extracts from Rabdosia rubescens

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Li Ping Cheng

2014-12-01

Full Text Available The antibacterial activities and mechanism of action of acetone extracts from R. rubescens were reported in this paper. The results showed that 80% acetone extracts had both the highest contents of total phenolics and flavonoids. Acetone extracts showed better antibacterial activities against Gram-positive bacterial strains and there were no inhibitory effects found on tested Gram-negative bacteria. In addition, 80% acetone extracts from R. rubescens had relatively higher antibacterial activities with the lowest values of MIC and MBC at 2.5 mg/mL and 5 mg/mL against B. subtilis. The antibacterial mechanism of 80% acetone extracts against Bacillus subtilis might be described as disrupting cell wall, increasing cell membrane permeability, and finally leading to the leakage of cell constituents

Sensor gas analyzer for acetone determination in expired air

Science.gov (United States)

Baranov, Vitaly V.

2001-05-01

Diseases and changes in the way of life change the concentration and composition of the expired air. Our adaptable gas analyzer is intended for the selective analysis of expired air and can be adapted for the solution of current diagnostic and analytical tasks by the user (a physician or a patient). Having analyzed the existing trends in the development of noninvasive diagnostics we have chosen the method of noninvasive acetone detection in expired air, where the acetone concentration correlates with blood and urine glucose concentrations. The appearance of acetone in expired air is indicative of disorders that may be caused not only by diabetes but also be wrong diet, incorrect sportsmen training etc. To control the disorders one should know the acetone concentration in the human body. This knowledge allows one to judge upon the state of the patient, choose a correct diet that will not cause damage to the patient's health, determine sportsmen training efficiency and results and solve the artificial pancreas problem. Our device provide highly accurate analysis, rapid diagnostics and authentic acetone quantification in the patient's body at any time aimed at prediction of the patient's state and assessing the efficiency of the therapy used. Clinical implementation of the device will improve the health and save lives of many thousands of diabetes sufferers.

IR spectra and properties of solid acetone, an interstellar and cometary molecule

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Hudson, Reggie L.; Gerakines, Perry A.; Ferrante, Robert F.

2018-03-01

Mid-infrared spectra of amorphous and crystalline acetone are presented along with measurements of the refractive index and density for both forms of the compound. Infrared band strengths are reported for the first time for amorphous and crystalline acetone, along with IR optical constants. Vapor pressures and a sublimation enthalpy for crystalline acetone also are reported. Positions of 13C-labeled acetone are measured. Band strengths are compared to gas-phase values and to the results of a density-functional calculation. A 73% error in previous work is identified and corrected.

Effects of ozone and ozone/peroxide on trace organic contaminants and NDMA in drinking water and water reuse applications.

Science.gov (United States)

Pisarenko, Aleksey N; Stanford, Benjamin D; Yan, Dongxu; Gerrity, Daniel; Snyder, Shane A

2012-02-01

An ozone and ozone/peroxide oxidation process was evaluated at pilot scale for trace organic contaminant (TOrC) mitigation and NDMA formation in both drinking water and water reuse applications. A reverse osmosis (RO) pilot was also evaluated as part of the water reuse treatment train. Ozone/peroxide showed lower electrical energy per order of removal (EEO) values for TOrCs in surface water treatment, but the addition of hydrogen peroxide increased EEO values during wastewater treatment. TOrC oxidation was correlated to changes in UV(254) absorbance and fluorescence offering a surrogate model for predicting contaminant removal. A decrease in N-nitrosodimethylamine (NDMA) formation potential (after chloramination) was observed after treatment with ozone and ozone/peroxide. However, during spiking experiments with surface water, ozone/peroxide achieved limited destruction of NDMA, while in wastewaters net direct formation of NDMA of 6-33 ng/L was observed after either ozone or ozone/peroxide treatment. Once formed during ozonation, NDMA passed through the subsequent RO membranes, which highlights the significance of the potential for direct NDMA formation during oxidation in reuse applications. Copyright © 2011 Elsevier Ltd. All rights reserved.

Heat transfer performance of a pulsating heat pipe charged with acetone-based mixtures

Science.gov (United States)

Wang, Wenqing; Cui, Xiaoyu; Zhu, Yue

2017-06-01

Pulsating heat pipes (PHPs) are used as high efficiency heat exchangers, and the selection of working fluids in PHPs has a great impact on the heat transfer performance. This study investigates the thermal resistance characteristics of the PHP charged with acetone-based binary mixtures, where deionized water, methanol and ethanol were added to and mixed with acetone, respectively. The volume mixing ratios were 2:1, 4:1 and 7:1, and the heating power ranged from 10 to 100 W with filling ratios of 45, 55, 62 and 70%. At a low filling ratio (45%), the zeotropic characteristics of the binary mixtures have an influence on the heat transfer performance of the PHP. Adding water, which has a substantially different boiling point compared with that of acetone, can significantly improve the anti-dry-out ability inside the PHP. At a medium filling ratio (55%), the heat transfer performance of the PHP is affected by both phase transition characteristics and physical properties of working fluids. At high heating power, the thermal resistance of the PHP with acetone-water mixture is between that with pure acetone and pure water, whereas the thermal resistance of the PHP with acetone-methanol and acetone-ethanol mixtures at mixing ratios of 2:1 and 4:1 is less than that with the corresponding pure fluids. At high filling ratios (62 and 70%), the heat transfer performance of the PHP is mainly determined by the properties of working fluids that affects the flow resistance. Thus, the PHP with acetone-methanol and acetone-ethanol mixtures that have a lower flow resistance shows better heat transfer performance than that with acetone-water mixture.

Pathological effects of acetone cyanohydrin in swiss rats

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Marcos Natal Rufino

Full Text Available ABSTRACT Cassava has been widely used for animal and human nutrition. It has also been demonstrated to have antineoplastic and anthelmintic properties. Toxicity due to cassava consumption has been reported in ruminants and laboratory animals; therefore, this study aimed to investigate the toxic effects of acetone cyanohydrin, a metabolite of linamarin that is present in cassava, in Wistar rats. Six groups of five animals each were used to evaluate the toxic effects of acetone cyanohydrin administered at 25 (G1, 50 (G2, 75 (G3, 100 (G4 and 125 (G5 µmol/kg as a single oral dose. The control group received acidified water (pH 3.5. The animals were monitored after administration of acetone cyanohydrin, and clinical symptoms were recorded. Serum enzyme levels were measured to assess the kidney and liver function. During necropsy, tissue samples were collected for histopathological examination. After administration, some animals in the G2, G4, and G5 groups presented neurological symptoms such as convulsions, involuntary muscle contraction, staggering gait, motor coordination disability, prostration, and mydriasis. All of the animals in the G5 and four animals in the G4 group died seven minutes after the administration of acetone cyanohydrin. Animals in the other groups, particularly in G2, recovered from the acute phase. Biochemical analysis revealed hepatic lesions and liver dysfunction. Histopathology revealed severe lesions in both the liver and brain. In conclusion, acetone cyanohydrin has toxic effects in the liver, lung, and central nervous system in rats; however, at concentrations up to 25 µmol/kg, the animals could survive the acute phase.

Sex-related differences in NADPH-dependent lipid peroxidation induced by cadmium

Energy Technology Data Exchange (ETDEWEB)

Sato, Masao; Nagai, Yasushi

1986-10-01

Male and female rats were dosed once a day for 2 days with injections of 1.5 mg Cd/kg. Formation of thiobarbituric acid reactive substances (TBA-RS) was significantly increased in male rat liver but not in the females. NADPH-dependent lipid peroxidation in vitro in microsomes derived from untreated rat liver was greater in males than in females. Furthermore, addition of cadmium (Cd) to microsomes isolated from male rat liver produced a dose-dependent potentiation of NADPH-dependent lipid peroxidation from low concentrations of CD. In microsomes derived from females a significant increase in lipid peroxidation was observed only at high Cd concentrations. NADPH-dependent lipid peroxidation enhanced by Cd was greater in the males than in the females. These data suggest that a sex-related difference in the ability of Cd to induce lipid peroxidation in vivo in rat liver appears to be mediated partly through differences in hepatic microsomal NADPH-dependent lipid peroxidation.

Evidence for an Inducible Nucleotide-Dependent Acetone Carboxylase in Rhodococcus rhodochrous B276

OpenAIRE

Clark, Daniel D.; Ensign, Scott A.

1999-01-01

The metabolism of acetone was investigated in the actinomycete Rhodococcus rhodochrous (formerly Nocardia corallina) B276. Suspensions of acetone- and isopropanol-grown R. rhodochrous readily metabolized acetone. In contrast, R. rhodochrous cells cultured with glucose as the carbon source lacked the ability to metabolize acetone at the onset of the assay but gained the ability to do so in a time-dependent fashion. Chloramphenicol and rifampin prevented the time-dependent increase in this acti...

Phase transitions of amorphous solid acetone in confined geometry investigated by reflection absorption infrared spectroscopy.

Science.gov (United States)

Shin, Sunghwan; Kang, Hani; Kim, Jun Soo; Kang, Heon

2014-11-26

We investigated the phase transformations of amorphous solid acetone under confined geometry by preparing acetone films trapped in amorphous solid water (ASW) or CCl4. Reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD) were used to monitor the phase changes of the acetone sample with increasing temperature. An acetone film trapped in ASW shows an abrupt change in the RAIRS features of the acetone vibrational bands during heating from 80 to 100 K, which indicates the transformation of amorphous solid acetone to a molecularly aligned crystalline phase. Further heating of the sample to 140 K produces an isotropic solid phase, and eventually a fluid phase near 157 K, at which the acetone sample is probably trapped in a pressurized, superheated condition inside the ASW matrix. Inside a CCl4 matrix, amorphous solid acetone crystallizes into a different, isotropic structure at ca. 90 K. We propose that the molecularly aligned crystalline phase formed in ASW is created by heterogeneous nucleation at the acetone-water interface, with resultant crystal growth, whereas the isotropic crystalline phase in CCl4 is formed by homogeneous crystal growth starting from the bulk region of the acetone sample.

(RS-Efonidipine acetone hemisolvate

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Yu-Heng Liu

2016-09-01

Full Text Available The asymmetric unit of the title compound, C34H38N3O7P·0.5C3H6O {systematic name: (RS-2-[phenyl(phenylmethylamino]ethyl 5-(5,5-dimethyl-2-oxo-1,3-dioxa-2λ5-phosphacyclohex-2-yl-2,6-dimethyl-4-(3-nitrophenyl-1,4-dihydropyridine-3-carboxylate acetone hemisolvate}, contains one R-efonidipine molecule, one S-efonidipine molecule and half of a solvate acetone molecule. In both efonidipine molecules, the six-membered rings of the dioxaphosphinanyl moieties display a chair conformation and the dihydropyridine rings display a flattened boat conformation. In the crystal, N—H...O, C—H...O hydrogen bonds and weak C—H...π interactions link the molecules into a three-dimensional supramolecular structure. A solvent-accessible void of 199 Å3 is found in the structure; the contribution of the heavily disordered solvate molecule was suppressed by use of the SQUEEZE routine in PLATON [Spek (2015. Acta Cryst. C71, 9–18].

Mass Spectrometry of Intact Proteins Reveals +98 u Chemical Artifacts Following Precipitation in Acetone.

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Güray, Melda Z; Zheng, Shi; Doucette, Alan A

2017-02-03

Protein precipitation in acetone is frequently employed ahead of mass spectrometry for sample preconcentration and purification. Unfortunately, acetone is not chemically inert; mass artifacts have previously been observed on glycine-containing peptides when exposed to acetone under acidic conditions. We herein report a distinct chemical modification occurring at the level of intact proteins when incubated in acetone. This artifact manifests as one or more satellite peaks in the MS spectrum of intact protein, spaced 98 u above the mass of the unmodified protein. Other artifacts (+84, +112 u) also appear upon incubation of proteins or peptides in acetone. The reaction is pH-sensitive, being suppressed when proteins are exposed to acetone under acidic conditions. The +98 u artifact is speculated to originate through an intermediate product of aldol condensation of acetone to form diacetone alcohol and mesityl oxide. A +98 u product could originate from nucleophilic attack on mesityl oxide or through condensation with diacetone alcohol. Given the extent of modification possible upon exposure of proteins to acetone, particularly following overnight solvent exposure or incubation at room temperature, an awareness of the variables influencing this novel modification is valued by proteomics researchers who employ acetone precipitation for protein purification.

Solvent (acetone-butanol: ab) production

Science.gov (United States)

This article describes production of butanol [acetone-butanol-ethanol, (also called AB or ABE or solvent)] by fermentation using both traditional and current technologies. AB production from agricultural commodities, such as corn and molasses, was an important historical fermentation. Unfortunately,...

Human sensory response to acetone/air mixtures.

Science.gov (United States)

Salthammer, T; Schulz, N; Stolte, R; Uhde, E

2016-10-01

The release of organic compounds from building products may influence the perceived air quality in the indoor environment. Consequently, building products are assessed for chemical emissions and for the acceptability of emitted odors. A procedure for odor evaluations in test chambers is described by the standard ISO 16000-28. A panel of eight or more trained subjects directly determines the perceived intensity Π (unit pi) of an air sample via diffusers. For the training of the panelists, a comparative Π-scale is applied. The panelists can use acetone/air mixtures in a concentration range between 20 mg/m(3) (0 pi) and 320 mg/m(3) (15 pi) as reference. However, the training and calibration procedure itself can substantially contribute to the method uncertainty. This concerns the assumed odor threshold of acetone, the variability of panelist responses, and the analytical determination of acetone concentrations in air with online methods as well as the influence of the diffuser geometry and the airflow profile. © 2015 The Authors. Indoor Air published by John Wiley & Sons Ltd.

Electrochemical peroxidation of PCBs and VOCs in superfund site water and sediments

Energy Technology Data Exchange (ETDEWEB)

Scrudato, R.J.; Chiarenzelli, J.R. [SUNY, Oswego, NY (United States)

1996-12-31

An electrochemical peroxidation (ECP) process has been developed and used to degrade polychlorinated biphenyls (PCB) and volatile organic compounds (VOC)-contaminated water, sludge, and sediments at a New York State Federal and State Superfund Site. The process involves passing an oscillating low-amperage (<10 amps) current through steel electrodes immersed in an acidified water or sediment slurry into which hydrogen peroxide (<1,000 ppm) is added. The generated free radicals attack organic compounds, including organo-metallic complexes and refractory compounds including PCBs. PCB degradation ranged from about 30% to 80% in experiments involving Federal Superfund Site sediments; total PCBs were reduced by {approximately}97% to 68%, respectively, in water and slurry collected from a State Superfund subsurface storage tank. VOC bench-scale experiments involved chloroethane, 1,1-dichloroethane, dichloromethane, 1,1,1-trichloroethane, and acetone and after a 3-min ECP treatment, degradation ranged from >94% to about 99.9%. Results indicate the ECP is a viable process to degrade organic contaminants in water and sediment suspensions. Because the treated water suspensions are acidified, select trace metal sorbed to the particulates is solubilized and therefore can be segregated from the particulates, offering a process that simultaneously degrades organic contaminants and separates trace metals. 19 refs., 1 fig., 4 tabs.

On the adsorption/reaction of acetone on pure and sulfate-modified zirconias.

Science.gov (United States)

Crocellà, Valentina; Cerrato, Giuseppina; Morterra, Claudio

2013-08-28

In situ FTIR spectroscopy was employed to investigate some aspects of the ambient temperature (actually, IR-beam temperature) adsorption of acetone on various pure and sulfate-doped zirconia specimens. Acetone uptake yields, on all examined systems and to a variable extent, different types of specific molecular adsorption, depending on the kind/population of available surface sites: relatively weak H-bonding interaction(s) with surface hydroxyls, medium-strong coordinative interaction with Lewis acidic sites, and strong H-bonding interaction with Brønsted acidic centres. Moreover acetone, readily and abundantly adsorbed in molecular form, is able to undergo the aldol condensation reaction (yielding, as the main reaction product, adsorbed mesityl oxide) only if the adsorbing material possesses some specific surface features. The occurrence/non-occurrence of the acetone self-condensation reaction is discussed, and leads to conclusions concerning the sites that catalyze the condensation reaction that do not agree with either of two conflicting interpretations present in the literature of acetone uptake/reaction on, mainly, zeolitic systems. In particular, what turns out to be actually necessary for the acetone aldol condensation reaction to occur on the examined zirconia systems is the presence of coordinatively unsaturated O(2-) surface sites of basicity sufficient to lead to the extraction of a proton from one of the CH3 groups of adsorbed acetone.

Breath acetone monitoring by portable Si:WO3 gas sensors

Science.gov (United States)

Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E.

2013-01-01

Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (~20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. PMID:22790702

Home-made Detection Device for a Mixture of Ethanol and Acetone

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Sukon Phanichphant

2007-02-01

Full Text Available A device for the detection and determination of ethanol and acetone wasconstructed, consisting of a packed column, a chamber with a sensor head, 2 dc powersupplies, a multimeter and a computer. A commercially available TGS 822 detector head(Figaro Company Limited was used as the sensor head. The TGS 822 detector consists of aSnO2 thick film deposited on the surface of an alumina ceramic tube which contains aheating element inside. An analytical column was coupled with the setup to enhance theseparation of ethanol and acetone before they reached the sensor head. Optimum systemconditions for detection of ethanol and acetone were achieved by varying the flow rate of thecarrier gas, voltage of the heating coil (VH, voltage of the circuit sensor (VC, loadresistance of the circuit sensor (RL and the injector port temperature. The flow of the carriergas was 15 mL/min; the circuit conditions were VH = 5.5 V, VC = 20 V, RL = 68 k ; and theinjection port temperature was 150°C. Under these conditions the retention times (tR forethanol and acetone were 1.95 and 0.57 minutes, respectively. Calibration graphs wereobtained for ethanol and acetone over the concentration range of 10 to 160 mg/L. The limitsof detection (LOD for ethanol and acetone were 9.25 mg/L and 4.41 mg/L respectively.

Carbonylation as a key reaction in anaerobic acetone activation by Desulfococcus biacutus.

Science.gov (United States)

Gutiérrez Acosta, Olga B; Hardt, Norman; Schink, Bernhard

2013-10-01

Acetone is activated by aerobic and nitrate-reducing bacteria via an ATP-dependent carboxylation reaction to form acetoacetate as the first reaction product. In the activation of acetone by sulfate-reducing bacteria, acetoacetate has not been found to be an intermediate. Here, we present evidence of a carbonylation reaction as the initial step in the activation of acetone by the strictly anaerobic sulfate reducer Desulfococcus biacutus. In cell suspension experiments, CO was found to be a far better cosubstrate for acetone activation than CO2. The hypothetical reaction product, acetoacetaldehyde, is extremely reactive and could not be identified as a free intermediate. However, acetoacetaldehyde dinitrophenylhydrazone was detected by mass spectrometry in cell extract experiments as a reaction product of acetone, CO, and dinitrophenylhydrazine. In a similar assay, 2-amino-4-methylpyrimidine was formed as the product of a reaction between acetoacetaldehyde and guanidine. The reaction depended on ATP as a cosubstrate. Moreover, the specific activity of aldehyde dehydrogenase (coenzyme A [CoA] acylating) tested with the putative physiological substrate was found to be 153 ± 36 mU mg(-1) protein, and its activity was specifically induced in extracts of acetone-grown cells. Moreover, acetoacetyl-CoA was detected (by mass spectrometry) after the carbonylation reaction as the subsequent intermediate after acetoacetaldehyde was formed. These results together provide evidence that acetoacetaldehyde is an intermediate in the activation of acetone by sulfate-reducing bacteria.

High acetone-butanol-ethanol production in pH-stat co-feeding of acetate and glucose.

Science.gov (United States)

Gao, Ming; Tashiro, Yukihiro; Wang, Qunhui; Sakai, Kenji; Sonomoto, Kenji

2016-08-01

We previously reported the metabolic analysis of butanol and acetone production from exogenous acetate by (13)C tracer experiments (Gao et al., RSC Adv., 5, 8486-8495, 2015). To clarify the influence of acetate on acetone-butanol-ethanol (ABE) production, we first performed an enzyme assay in Clostridium saccharoperbutylacetonicum N1-4. Acetate addition was found to drastically increase the activities of key enzymes involved in the acetate uptake (phosphate acetyltransferase and CoA transferase), acetone formation (acetoacetate decarboxylase), and butanol formation (butanol dehydrogenase) pathways. Subsequently, supplementation of acetate during acidogenesis and early solventogenesis resulted in a significant increase in ABE production. To establish an efficient ABE production system using acetate as a co-substrate, several shot strategies were investigated in batch culture. Batch cultures with two substrate shots without pH control produced 14.20 g/L butanol and 23.27 g/L ABE with a maximum specific butanol production rate of 0.26 g/(g h). Furthermore, pH-controlled (at pH 5.5) batch cultures with two substrate shots resulted in not only improved acetate consumption but also a further increase in ABE production. Finally, we obtained 15.13 g/L butanol and 24.37 g/L ABE at the high specific butanol production rate of 0.34 g/(g h) using pH-stat co-feeding method. Thus, in this study, we established a high ABE production system using glucose and acetate as co-substrates in a pH-stat co-feeding system with C. saccharoperbutylacetonicum N1-4. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Derivatization reaction-based surface-enhanced Raman scattering (SERS) for detection of trace acetone.

Science.gov (United States)

Zheng, Ying; Chen, Zhuo; Zheng, Chengbin; Lee, Yong-Ill; Hou, Xiandeng; Wu, Li; Tian, Yunfei

2016-08-01

A facile method was developed for determination of trace volatile acetone by coupling a derivatization reaction to surface-enhanced Raman scattering (SERS). With iodide modified Ag nanoparticles (Ag IMNPs) as the SERS substrate, acetone without obvious Raman signal could be converted to SERS-sensitive species via a chemical derivatization reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH). In addition, acetone can be effectively separated from liquid phase with a purge-sampling device and then any serious interference from sample matrices can be significantly reduced. The optimal conditions for the derivatization reaction and the SERS analysis were investigated in detail, and the selectivity and reproducibility of this method were also evaluated. Under the optimal conditions, the limit of detection (LOD) for acetone was 5mgL(-1) or 0.09mM (3σ). The relative standard deviation (RSD) for 80mgL(-1) acetone (n=9) was 1.7%. This method was successfully used for the determination of acetone in artificial urine and human urine samples with spiked recoveries ranging from 92% to 110%. The present method is convenient, sensitive, selective, reliable and suitable for analysis of trace acetone, and it could have a promising clinical application in early diabetes diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultraviolet- and sunlight-induced lipid peroxidation in liposomal membrane

International Nuclear Information System (INIS)

Mandal, T.K.; Chatterjee, S.N.

1980-01-01

Ultraviolet radiation and sunlight caused lipid peroxidation in the liposomal membrane (as detected by measurement of the oxidation index, A 233 /A 215 , and the amount of malondialdehyde formed) and made the membrane leaky (as revealed by the release of the trapped chromate anions). The oxidation index and the formation of malondialdehyde increased linearly with increasing dose of radiation and depended significantly on the dose rate. The effects were smaller in liposomes derived from Vibrio cholerae phospholipid than in those derived from egg lecithin. The effects of the radiation dose and dose rate on hemolysis and peroxidation (MDA formation) of the erythrocyte membrane followed a similar pattern. A direct correlation between the percentage leakage of chromate (Y) and the oxidation index (X) of the liposomal system was obtained as Y = 236.5 x X

Evaluation of acetone vapors toxicity on Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae) eggs.

Science.gov (United States)

Pourmirza, Ali Asghr; Nasab, Fershteh Sadeghi; Zadeh, Abas Hossein

2007-08-01

The efficacy of acetone vapors against carefully aged eggs of Plodia interpunctella (Hubner) at 17+/-1 and 27+/-1 degrees C at different dosage levels of acetone over various exposure times was determined. Acetone was found to be toxic to Indian meal moth eggs. Considerable variation in the susceptibility of different age groups of eggs was apparent in the fiducial limits of the LD50 values. An inverse relationship between LD50 values and exposure times was observed in age groups of tested eggs. At 27+/-1 degrees C and 24 h exposure period, eggs aged 1-2 day-old were more tolerant to acetone than other age groups, followed by 0-1 day-old, 2-3 day-old and 3-4 day-old eggs. A similar pattern of susceptibility of eggs was observed at 72 h exposure. In all bioassays, eggs exposed to higher dosages of acetone developed at smaller rate. This was significant for the eggs, which were exposed to the highest dosage for 24 h. Increasing the temperature from 17+/-1 to 27+/-1 degrees C greatly increased the efficacy of acetone. At 27+/-1 degrees C eggs of P. interpunctella were killed by less than one-third of the dosage required for control at 17+/-1 degrees C. Acetone achieved 50% mortality with a dosage of 82.76 mg L(-1) in 1-2 day-old eggs at 27+/-1 degrees C. At this temperature hatching was retarded and greatly diminished when eggs aged 1-2 day-old were exposed to 80 mg L(-1) of acetone for the 24 h exposure period. There was no evidence of a hatch delay longer than the time spent under vapors for eggs exposed at 17+/-1 or 27+/-1 degrees C, indicating that some development must have occurred under fumigation.

Weak carbonyl-methyl intermolecular interactions in acetone clusters explored by IR plus VUV spectroscopy

International Nuclear Information System (INIS)

Guan, Jiwen; Hu, Yongjun; Xie, Min; Bernstein, Elliot R.

2012-01-01

Highlights: ► The carbonyl overtone of acetone clusters is observed by IR-VUV spectroscopy. ► Acetone molecules in the dimer are stacked with an antiparallel way. ► The structure of the acetone trimer and the tetramer are the cyclic structures. ► The carbonyl groups would interact with the methyl groups in acetone clusters. ► These weak interactions are further confirmed by H/D substitution experiment. -- Abstract: Size-selected IR–VUV spectroscopy is employed to detect vibrational characteristics in the region 2850 ∼ 3550 cm −1 of neutral acetone and its clusters (CH 3 COCH 3 ) n (n = 1–4). Features around 3440 cm −1 in the spectra of acetone monomer and its clusters are assigned to the carbonyl stretch (CO) overtone. These features red-shift from 3455 to 3433 cm −1 as the size of the clusters increases from the monomer to the tetramer. Based on calculations, the experimental IR spectra in the C=O overtone region suggest that the dominant structures for the acetone trimer and tetramer should be cyclic in the supersonic expansion sample. This study also suggests that the carbonyl groups interact with the methyl groups in the acetone clusters. These weak interactions are further confirmed by the use of deuterium substitution.

Solvents (butanol, acetone, and ethanol)

Energy Technology Data Exchange (ETDEWEB)

Yarovenko, V L; Nakhmanovich, B M

1963-07-17

The method involves use of carbohydrate containing plant raw-material, e.g., hydrolyzates of corn cob and pulp. The material is subjected to fermentation with acetone-butanol bacteria with addition of starch-industry wastes as source of proteins (gluten and gluten-containing water) and nutrient salts.

Iron release from ferritin and lipid peroxidation by radiolytically generated reducing radicals

International Nuclear Information System (INIS)

Reif, D.W.; Schubert, J.; Aust, S.D.

1988-01-01

Iron is involved in the formation of oxidants capable of damaging membranes, protein, and DNA. Using 137 Cs gamma radiation, we investigated the release of iron from ferritin and concomitant lipid peroxidation by radiolytically generated reducing radicals, superoxide and the carbon dioxide anion radical. Both radicals released iron from ferritin with similar efficiencies and iron mobilization from ferritin required an iron chelator. Radiolytically generated superoxide anion resulted in peroxidation of phospholipid liposomes as measured by malondialdehyde formation only when ferritin was included as an iron source and the released iron was found to be chelated by the phospholipid liposomes

Fermentation and genomic analysis of acetone-uncoupled butanol production by Clostridium tetanomorphum.

Science.gov (United States)

Gong, Fuyu; Bao, Guanhui; Zhao, Chunhua; Zhang, Yanping; Li, Yin; Dong, Hongjun

2016-02-01

In typical acetone-butanol-ethanol (ABE) fermentation, acetone is the main by-product (50 % of butanol mass) of butanol production, resulting in a low yield of butanol. It is known that some Clostridium tetanomorphum strains are able to produce butanol without acetone in nature. Here, we described that C. tetanomorphum strain DSM665 can produce 4.16 g/L butanol and 4.98 g/L ethanol at pH 6.0, and 9.81 g/L butanol and 1.01 g/L ethanol when adding 1 mM methyl viologen. Butyrate and acetate could be reassimilated and no acetone was produced. Further analysis indicated that the activity of the acetate/butyrate:acetoacetyl-CoA transferase responsible for acetone production is lost in C. tetanomorphum DSM665. The genome of C. tetanomorphum DSM665 was sequenced and deposited in DDBJ, EMBL, and GenBank under the accession no. APJS00000000. Sequence analysis indicated that there are no typical genes (ctfA/B and adc) that are typically parts of an acetone synthesis pathway in C. tetanomorphum DSM665. This work provides new insights in the mechanism of clostridial butanol production and should prove useful for the design of a high-butanol-producing strain.

An isotope dependent study of acetone in its lowest excited triplet state

International Nuclear Information System (INIS)

Gehrtz, M.; Brauchle, C.; Voitlaender, J.

1984-01-01

The lowest excited triplet state T 1 of acetone-h 6 and acetone-d 6 was investigated with a pulsed dye laser equipped ODMR spectrometer. Acetone is found to be bent in T 1 and the out-of-plane distortion angle is estimated to be approx.= 38 0 . The observed zero-field splitting (ZFS) is surprisingly small. Both the spin-spin and the spin-orbit (SO) contribution to the ZFS are evaluated. The SO tensor contribution is calculated from a correlation between the deuterium effects on the ZFS parameters and the population rates. The sub-level selective kinetics of the acetone T 1 is largely determined by the mixing of the x- and z-level characteristics owing to magnetic axis rotation caused by the excited state out-of-plane distortion. Considerable deuterium effects are observed on the kinetic data and on the microwave transition frequencies. In all cases the spin-specific isotope effects (due to the promoting modes) and the global effects (due to the Franck-Condon factors) are specified. For the population rates and the SO contribution to ZFS, the inverse global isotope effects (deuterium factor > 1) was found for the first time. Based on the isotope dependence of the rates, the mechanisms of (vibrationally induced) SO coupling in acetone are discussed. It is concluded that non-adiabatic contributions have to be taken into account for the smallest population rate only, but that otherwise the adiabatic SO coupling mechanisms by far dominates in the acetone photophysics. (author)

Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

Science.gov (United States)

Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

1988-01-01

The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

Performance of Cr-doped ZnO for acetone sensing

Energy Technology Data Exchange (ETDEWEB)

Al-Hardan, N.H., E-mail: naif_imen@ukm.my [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Abdullah, M.J.; Aziz, A. Abdul [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

2013-04-01

Zinc oxide (ZnO) doped with chromium (Cr) was synthesized by reactive co-sputtering for gas sensing applications. The effect of varying the contents of Cr (from 1 to 4 at%) on the ZnO gas sensor response was studied. X-ray diffraction analysis reveals the high orientation of c-axis of the prepared films. The optimum operating temperature of the undoped ZnO was 400 °C and shifted to 300 °C for the Cr-doped ZnO under the acetone vapour. The 1% Cr doping ZnO gas sensor was most sensitive for the acetone vapour. The ability of the 1% Cr-doped ZnO to produce repeatable results under different acetone vapour concentrations was tested. The timing properties of the doped Cr ZnO gas sensor were 70 and 95 s for the rise and recovery time respectively.

Flow injection determination of hydrogen peroxide using catalytic effect of cobalt(II) ion on a dye formation reaction.

Science.gov (United States)

Kurihara, Makoto; Muramatsu, Miyuki; Yamada, Mari; Kitamura, Naoya

2012-07-15

A novel flow injection photometric method was developed for the determination of hydrogen peroxide in rainwater. This method is based on a cobalt(II)-catalyzed oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone (MBTH) with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline (DAOS) as a modified Trinder's reagent to produce intensely colored dye (λ(max)=530nm) in the presence of hydrogen peroxide at pH 8.4. In this method, 1,2-dihydroxy-3,5-benzenedisulfonic acid (Tiron) acted as an activator for the cobalt(II)-catalyzed reaction and effectively increased the peak height for hydrogen peroxide. The linear calibration graphs were obtained in the hydrogen peroxide concentration range 5×10(-8) to 2.2×10(-6)mol dm(-3) at a sampling rate of 20h(-1). The relative standard deviations for ten determinations of 2.2×10(-6) and 2×10(-7)mol dm(-3) hydrogen peroxide were 1.1% and 3.7%, respectively. The proposed method was successfully applied to the determination of hydrogen peroxide in rainwater samples and the analytical results agreed fairly well with the results obtained by different two reference methods; peroxidase method and hydrogen peroxide electrode method. Copyright © 2012 Elsevier B.V. All rights reserved.

Selective bio-oxidation of propane to acetone using methane-oxidizing Methylomonas sp. DH-1.

Science.gov (United States)

Hur, Dong Hoon; Nguyen, Thu Thi; Kim, Donghyuk; Lee, Eun Yeol

2017-07-01

Propane is the major component of liquefied petroleum gas (LPG). Nowadays, the use of LPG is decreasing, and thus utilization of propane as a chemical feedstock is in need of development. An efficient biological conversion of propane to acetone using a methanotrophic whole cell as the biocatalyst was proposed and investigated. A bio-oxidation pathway of propane to acetone in Methylomonas sp. DH-1 was analyzed by gene expression profiling via RNA sequencing. Propane was oxidized to 2-propanol by particulate methane monooxygenase and subsequently to acetone by methanol dehydrogenases. Methylomonas sp. DH-1 was deficient in acetone-converting enzymes and thus accumulated acetone in the absence of any enzyme inhibition. The maximum accumulation, average productivity and specific productivity of acetone were 16.62 mM, 0.678 mM/h and 0.141 mmol/g cell/h, respectively, under the optimized conditions. Our study demonstrates a novel method for the bioconversion of propane to acetone using methanotrophs under mild reaction condition.

Multiphoton ionization and fragmentation study of acetone using 308 nm laser radiation

Science.gov (United States)

Liu Houxiang, Li Shutao, Han Jingcheng, Zhu Rong, Guan Yifu, Wu Cunkai

1988-10-01

Multiphoton ionization and fragmentation (MPI-F) of acetone molecules using 308 nm laser radiation was studied by using a molecular beam and quadrupole mass spectrometer. The ion peaks of acetone molecule appear at m/e=15 and 43, corresponding to the two fragments CH3+ and CH3CO+. It is considered that these two ions are, respectively, formed by direct (2+1) and 2-photon ionization of methyl and acetyl radicals, generated by photodissociation of acetone molecule.

Spray deposited gallium doped tin oxide thinfilm for acetone sensor application

Science.gov (United States)

Preethi, M. S.; Bharath, S. P.; Bangera, Kasturi V.

2018-04-01

Undoped and gallium doped (1 at.%, 2 at.% and 3 at.%) tin oxide thin films were prepared using spray pyrolysis technique by optimising the deposition conditions such as precursor concentration, substrate temperature and spraying rate. X-ray diffraction analysis revealed formation of tetragonally structured polycrystalline films. The SEM micrographs of Ga doped films showed microstructures. The electrical resistivity of the doped films was found to be more than that of the undoped films. The Ga-doped tin oxide thin films were characterised for gas sensors. 1 at.% Ga doped thin films were found to be better acetone gas sensor, showed 68% sensitivity at 350°C temperature.

Efficient acetone-butanol-ethanol production by Clostridium beijerinckii from sugar beet pulp.

Science.gov (United States)

Bellido, Carolina; Infante, Celia; Coca, Mónica; González-Benito, Gerardo; Lucas, Susana; García-Cubero, María Teresa

2015-08-01

Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

An analysis of human response to the irritancy of acetone vapors

NARCIS (Netherlands)

Arts, J.H.E.; Mojet, J.; Gemert, L.J. van; Emmen, H.H.; Lammers, J.H.C.M.; Marquart, J.; Woutersen, R.A.; Feron, V.J.

2002-01-01

Studies on the irritative effects of acetone vapor in humans and experimental animals have revealed large differences in the lowest acetone concentration found to be irritative to the respiratory tract and eyes. This has brought on much confusion in the process of setting occupational exposure

[Removal of high-abundance proteins in plasma of the obese by improved TCA/acetone precipitation method].

Science.gov (United States)

Wang, Jun; Feng, Liru; Yu, Wei; Xu, Jian; Yang, Hui; Liu, Xiaoli

2013-09-01

To develop an improved trichloroacetic acid (TCA)/acetone precipitation method for removal of high-abundance proteins in plasma of the obese. Volumes of TCA/acetone solution (1, 3, 4, 5, 6, 8, 10 and 20 times of the sample) and concentrations of TCA (10%, 30%, 50%, 60%, 70% TCA/acetone solution) have been investigated to optimize the conditions of sample preparation. SDS-PAGE were used to separate and tested proteins in the supernatant and sediment. The best concentration of the TCA/acetone solution was first determined by SDS-PAGE. The protein in precipitation from 10% TCA/acetone solution processing and the new determined concentration TCA/acetone solution processing were verified by 2-D-SDS-PAGE. And then the digested products of the protein in precipitation and supernatant by trypsin were analyzed by nano HPLC-Chip-MS/MS to verify which is the best concentration to process the plasma. The best volume of TCA/acetone is four times to sample, which less or more TCA/acetone would reduce the removal efficiency of high-abundance proteins. The concentration of TCA in acetone solution should be 60%, which may remove more high-abundance proteins in plasma than 10%, 30%, 50% TCA in acetone solution. If the TCA concentration is more than 60%, the reproducibility will be much poorer due to fast precipitation of proteins. The results of mass identification showed that human plasma prepared with 60% TCA/acetone (4 times sample volume) could be verified more low-abundance proteins than 10%. The most desirable conditions for removal of high-abundance proteins in plasma is 60% TCA/acetone (4 times sample volume), especially for the plasma of obesity.

Measurement of natural carbon isotopic composition of acetone in human urine.

Science.gov (United States)

Yamada, Keita; Ohishi, Kazuki; Gilbert, Alexis; Akasaka, Mai; Yoshida, Naohiro; Yoshimura, Ryoko

2016-02-01

The natural carbon isotopic composition of acetone in urine was measured in healthy subjects using gas chromatography-combustion-isotope ratio mass spectrometry combined with headspace solid-phase microextraction (HS-SPME-GC-C-IRMS). Before applying the technique to a urine sample, we optimized the measurement conditions of HS-SPME-GC-C-IRMS using aqueous solutions of commercial acetone reagents. The optimization enabled us to determine the carbon isotopic compositions within ±0.2 ‰ of precision and ±0.3‰ of error using 0.05 or 0.2 mL of aqueous solutions with acetone concentrations of 0.3-121 mg/L. For several days, we monitored the carbon isotopic compositions and concentrations of acetone in urine from three subjects who lived a daily life with no restrictions. We also monitored one subject for 3 days including a fasting period of 24 h. These results suggest that changes in the availability of glucose in the liver are reflected in changes in the carbon isotopic compositions of urine acetone. Results demonstrate that carbon isotopic measurement of metabolites in human biological samples at natural abundance levels has great potential as a tool for detecting metabolic changes caused by changes in physiological states and disease.

A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management.

Science.gov (United States)

Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

2016-07-30

Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no "best-practice method" for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T2D subjects, and healthy subjects. The results

Experimental results of acetone hydrogenation on a heat exchanger type reactor for solar chemical heat pump; Solar chemical heat pump ni okeru acetone suisoka hanno netsu kaishu jikken

Energy Technology Data Exchange (ETDEWEB)

Takashima, T; Doi, T; Tanaka, T; Ando, Y [Electrotechnical Laboratory, Tsukuba (Japan); Miyahara, R; Kamoshida, J [Shibaura Institute of Technology, Tokyo (Japan)

1996-10-27

With the purpose of converting solar heat energy to industrial heat energy, an experiment of acetone hydrogenation was carried out using a heat exchanger type reactor that recovers heat generated by acetone hydrogenation, an exothermic reaction, and supplies it to an outside load. In the experiment, a pellet-like activated carbon-supported ruthenium catalyst was used for the acetone hydrogenation with hydrogen and acetone supplied to the catalyst layer at a space velocity of 400-1,200 or so. In the external pipe of the double-pipe type reactor, a heating medium oil was circulated in parallel with the flow of the reactant, with the heat of reaction recovered that was generated from the acetone hydrogenation. In this experiment, an 1wt%Ru/C catalyst and a 5wt%Ru/C catalyst were used so as to examine the effects of variation in the space velocity. As a result, from the viewpoint of recovering the heat of reaction, it was found desirable to increase the reaction speed by raising catalytic density and also to supply the reactant downstream inside the reaction pipe by increasing the space velocity. 1 ref., 6 figs., 1 tab.

Chemo-enzymatic epoxidation of olefins by carboxylic acid esters and hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Ruesch gen. Klaas, M.; Warwel, S. [Inst. for Biochemistry and Technology of Lipids, H.P. Kaufmanm-Inst., Federal Centre for Cereal, Potato and Lipid Research, Muenster (Germany)

1998-12-31

Ethylen and, recently, butadiene can be epoxidized directly with oxygen and for the epoxidation of propylene, the use of heterogeneous transition metals and organic peroxides (Halcon-Process) is the major player. But, beside from those notable exceptions, all other epoxidations, including large ones like the epoxidation of plant oils as PVC-stabilizers (about 200.000 t/year), are carried out with peroxy acids. Because mcpba is far to expensive for most applications, short chain peracids like peracetic acid are used. Being much less stable than mcpba and thus risky handled in large amounts and high concentrations, these peroxy acids were preferably prepared in-situ. However, conventional in-situ formation of peracids has the serious drawback, that a strong acid is necessary to catalyze peroxy acid formation from the carboxylic acid and hydrogen peroxide. The presence of a strong acid in the reaction mixture often results in decreased selectivity because of the formation of undesired by-products by opening of the oxirane ring. Therefore, we propose a new method for epoxidation based on the in-situ preparation of percarboxylic acids from carboxylic acid esters and hydrogen peroxide catalyzed by a commercial, immobilized lipase. (orig.)

Diagnosis by acetone for deterioration of breathing transformers containing an adsorbent in the insulating oil; Acetone ni yoru kyuchakuzai iri kaihogata hen`atsuki no keinen rekkado shindan

Energy Technology Data Exchange (ETDEWEB)

Awata, M.; Mizuno, K.; Ueda, T. [Chubu Electric Power Co. Ltd., Nagoya (Japan); Ota, N.; Ishii, T.; Tsukioka, H.

1997-04-20

The high-precision diagnosis for deterioration of a breathing transformer containing an adsorbent was investigated. An adsorbent (activated alumina) may be contained in oil to eliminate the deterioration product in insulating oil or the moisture. In this case, the deterioration component furfural in insulating paper is adsorbed. The concentration in furfural oil cannot be thus used for deterioration diagnosis. Acetone and furan with good relation between the adsorption characteristics for activated alumina and the insulating paper deterioration in an accelerated deterioration test can be effectively used as a new deterioration index component of insulating paper. The disassembly survey showed that acetone is valid as the index component of deterioration diagnosis. Furan is not detected in a breathing transformer, but effective in diaphragm-type and nitrogen-sealed transformers. The adsorption of acetone by activated alumina requires no correction for the change in oil temperature at about 10{degree}C. The solubility of acetone for insulating oil is 60 times at 20{degree}C as high as CO2, and the discharge rate from a breather is little (1/25). Therefore, acetone is much more excellent than CO2 as the precision of a deterioration index. 21 refs., 15 figs., 4 tabs.

Ligands Exchange Process on Gold Nanoparticles in Acetone Solution

Science.gov (United States)

Hu, C. L.; Mu, Y. Y.; Bian, Z. C.; Luo, Z. H.; Luo, K.; Huang, A. Z.

2018-05-01

The ligands exchange process on gold nanoparticles (GNPs) was proceeded by using hydrophobic group (PPh3) and hydrophilic group (THPO) in acetone solution. The FTIR and XPS results demonstrated that part of THPO was replaced by PPh3 which was dissolved in polar solution (acetone); the results were in accordance with the electrochemical analysis where the differential capacity decreased with increasing exchange time. After 12 h, the exchange process terminated and the final ratio of PPh3 and THPO was about 1.4: 1. This ratio remained unchanged although the PPh3 and THPO modified GNPs re-dispersed in the PPh3 acetone solution demonstrating the stable adsorption of both ligands after exchanging for 12 h. The TEM images showed that the gold nanoparticles were self-assembled from scattered to arranged morphology due to the existence of hydrophilic and hydrophobic ligands and led to Janus gold nanoparticles.

Acetaminophen and acetone sensing capabilities of nickel ferrite nanostructures

Science.gov (United States)

Mondal, Shrabani; Kumari, Manisha; Madhuri, Rashmi; Sharma, Prashant K.

2017-07-01

Present work elucidates the gas sensing and electrochemical sensing capabilities of sol-gel-derived nickel ferrite (NF) nanostructures based on the electrical and electrochemical properties. In current work, the choices of target species (acetone and acetaminophen) are strictly governed by their practical utility and concerning the safety measures. Acetone, the target analyte for gas sensing measurement is a common chemical used in varieties of application as well as provides an indirect way to monitor diabetes. The gas sensing experiments were performed within a homemade sensing chamber designed by our group. Acetone gas sensor (NF pellet sensor) response was monitored by tracking the change in resistance both in the presence and absence of acetone. At optimum operating temperature 300 °C, NF pellet sensor exhibits selective response for acetone in the presence of other common interfering gases like ethanol, benzene, and toluene. The electrochemical sensor fabricated to determine acetaminophen is prepared by coating NF onto the surface of pre-treated/cleaned pencil graphite electrode (NF-PGE). The common name of target analyte acetaminophen is paracetamol (PC), which is widespread worldwide as a well-known pain killer. Overdose of PC can cause renal failure even fatal diseases in children and demand accurate monitoring. Under optimal conditions NF-PGE shows a detection limit as low as 0.106 μM with selective detection ability towards acetaminophen in the presence of ascorbic acid (AA), which co-exists in our body. Use of cheap and abundant PGE instead of other electrodes (gold/Pt/glassy carbon electrode) can effectively reduce the cost barrier of such sensors. The obtained results elucidate an ample appeal of NF-sensors in real analytical applications viz. in environmental monitoring, pharmaceutical industry, drug detection, and health monitoring.

An acetone bio-sniffer (gas phase biosensor) enabling assessment of lipid metabolism from exhaled breath.

Science.gov (United States)

Ye, Ming; Chien, Po-Jen; Toma, Koji; Arakawa, Takahiro; Mitsubayashi, Kohji

2015-11-15

Several volatile organic compounds (VOCs) are released from human breath or skin. Like chemical substances in blood or urine, some of these vapors can provide valuable information regarding the state of the human body. A highly sensitive acetone biochemical gas sensor (bio-sniffer) was developed and used to measure exhaled breath acetone concentration, and assess lipid metabolism based on breath acetone analysis. A fiber-optic biochemical gas sensing system was constructed by attaching a flow-cell with nicotinamide adenine dinucleotide (NADH)-dependent secondary alcohol dehydrogenase (S-ADH) immobilized membrane onto a fiber-optic NADH measurement system. The NADH measurement system utilizes an ultraviolet-light emitting diode with peak emission of 335 nm as an excitation light source. NADH is consumed by the enzymatic reaction of S-ADH, and the consumption is proportional to the concentration of acetone vapor. Phosphate buffer which contained NADH was circulated into the flow-cell to rinse products and the excessive substrates from the optode. The change of fluorescent emitted from NADH is analyzed by the PMT. Hence, fluorescence intensity decreased as the acetone concentration increased. The relationship between fluorescence intensity and acetone concentration was identified from 20 ppb to 5300 ppb. This interval included the concentration of acetone vapor in the breath of healthy people and those suffering from disorders of carbohydrate metabolism. Finally, the acetone bio-sniffer was used to measure breath acetone during an exercise stress test on an ergometer after a period of fasting. The concentration of acetone in breath was shown to significantly increase after exercise. This biosensor allows rapid, highly sensitive and selective measurement of lipid metabolism. Copyright © 2015 Elsevier B.V. All rights reserved.

Functional analysis of a novel hydrogen peroxide resistance gene in Lactobacillus casei strain Shirota.

Science.gov (United States)

Serata, Masaki; Kiwaki, Mayumi; Iino, Tohru

2016-11-01

Lactic acid bacteria have a variety of mechanisms for tolerance to oxygen and reactive oxygen species, and these mechanisms differ among species. Lactobacillus casei strain Shirota grows well under aerobic conditions, indicating that the various systems involved in oxidative stress resistance function in this strain. To elucidate the mechanism of oxidative stress resistance in L. casei strain Shirota, we examined the transcriptome response to oxygen or hydrogen peroxide exposure. We then focused on an uncharacterized gene that was found to be up-regulated by both oxygen and hydrogen peroxide stress; we named the gene hprA1 (hydrogen peroxide resistance gene). This gene is widely distributed among lactobacilli. We investigated the involvement of this gene in oxidative stress resistance, as well as the mechanism of tolerance to hydrogen peroxide. Growth of L. casei MS105, an hprA1-disrupted mutant, was not affected by oxygen stress, whereas the survival rate of MS105 after hydrogen peroxide treatment was markedly reduced compared to that of the wild-type. However, the activity of MS105 in eliminating hydrogen peroxide was similar to that of the wild-type. We cloned hprA1 from L. caseiShirota and purified recombinant HprA1 protein from Escherichia coli. We demonstrated that the recombinant HprA1 protein bound to iron and prevented the formation of a hydroxyl radical in vitro. Thus, HprA1 protein probably contributes to hydrogen peroxide tolerance in L. casei strain Shirota by binding to iron in the cells and preventing the formation of a hydroxyl radical.

Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach

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Ateeq Rahman

2011-01-01

Full Text Available The catalytic hydrogenation of acetone is an important area of catalytic process to produce fine chemicals. Hydrogenation of acetone has important applications for heat pumps, fuel cells or in fulfilling the sizeable demand for the production of 2-propanol. Catalytic vapour phase hydrogenation of acetone has gained attention over the decades with variety of homogeneous catalysts notably Iridium, Rh, Ru complexes and heterogeneous catalysts comprising of Raney Nickel, Raney Sponge, Ni/Al2O3, Ni/SiO2, or Co-Al2O3, Pd, Rh, Ru, Re, or Fe/Al2O3 supported on SiO2 or MgO and even CoMgAl, NiMg Al layered double hydroxide, Cu metal, CuO, Cu2O. Nano catalysts are developed for actone reduction Ni maleate, cobalt oxide prepared in organic solvents. Author present a review on acetone hydrogenation under different conditions with various homogeneous and heterogeneous catalysts studied so far in literature and new strategies to develop economic and environmentally benign approach. ©2010 BCREC UNDIP. All rights reserved(Received: 16th June 2010, Revised: 18th October 2010; Accepted: 25th October 2010[How to Cite:Ateeq Rahman. (2010. Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 113-126. doi:10.9767/bcrec.5.2.798.113-126][DOI: http://dx.doi.org/10.9767/bcrec.5.2.798.113-126 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/798

the effects of vitamin e supplementation on serum lipid peroxidation ...

African Journals Online (AJOL)

DR. C.O.NWAIGWE

The effects of dietary supplementation of vitamin E on feed intake and serum lipid peroxidation formation were ... belongs to the family Birnaviridae and of the genus Birnavirus ... diseases, Alzheimer's disease and increased resistance to ...

Breath acetone to monitor life style interventions in field conditions: an exploratory study.

Science.gov (United States)

Samudrala, Devasena; Lammers, Gerwen; Mandon, Julien; Blanchet, Lionel; Schreuder, Tim H A; Hopman, Maria T; Harren, Frans J M; Tappy, Luc; Cristescu, Simona M

2014-04-01

To assess whether breath acetone concentration can be used to monitor the effects of a prolonged physical activity on whole body lipolysis and hepatic ketogenesis in field conditions. Twenty-three non-diabetic, 11 type 1 diabetic, and 17 type 2 diabetic subjects provided breath and blood samples for this study. Samples were collected during the International Four Days Marches, in the Netherlands. For each participant, breath acetone concentration was measured using proton transfer reaction ion trap mass spectrometry, before and after a 30-50 km walk on four consecutive days. Blood non-esterified free fatty acid (NEFA), beta-hydroxybutyrate (BOHB), and glucose concentrations were measured after walking. Breath acetone concentration was significantly higher after than before walking, and was positively correlated with blood NEFA and BOHB concentrations. The effect of walking on breath acetone concentration was repeatedly observed on all four consecutive days. Breath acetone concentrations were higher in type 1 diabetic subjects and lower in type 2 diabetic subjects than in control subjects. Breath acetone can be used to monitor hepatic ketogenesis during walking under field conditions. It may, therefore, provide real-time information on fat burning, which may be of use for monitoring the lifestyle interventions. Copyright © 2014 The Obesity Society.

Self-Diffusion and Heteroassociation in an Acetone-Chloroform Mixture at 298 K

Science.gov (United States)

Golubev, V. A.; Gurina, D. L.; Kumeev, R. S.

2018-01-01

The self-diffusion coefficients of acetone and chloroform in a binary acetone-chloroform mixture at 298 K are determined via pulsed field gradient NMR spectroscopy. It is estimated that the hydrodynamic radii of the mixture's components, calculated using the Stokes-Einstein equation, grow as the concentrations of the components fall. It is shown that such behavior of hydrodynamic radii is due to acetone-chloroform heteroassociation. The hydrodynamic radii of monomers and heteroassociates in a 1: 1 ratio are determined along with the constant of heteroassociation, using the proposed model of an associated solution.

The effect of lipid peroxidation products on reactive oxygen species formation and nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages.

Science.gov (United States)

Ambrozova, Gabriela; Pekarova, Michaela; Lojek, Antonin

2011-02-01

Lipid peroxidation induced by oxidants leads to the formation of highly reactive metabolites. These can affect various immune functions, including reactive oxygen species (ROS) and nitric oxide (NO) production. The aim of the present study was to investigate the effects of lipid peroxidation products (LPPs) - acrolein, 4-hydroxynonenal, and malondialdehyde - on ROS and NO production in RAW 264.7 macrophages and to compare these effects with the cytotoxic properties of LPPs. Macrophages were stimulated with lipopolysaccharide (0.1 μg/ml) and treated with selected LPPs (concentration range: 0.1-100 μM). ATP test, luminol-enhanced chemiluminescence, Griess reaction, Western blotting analysis, amperometric and total peroxyl radical-trapping antioxidant parameter assay were used for determining the LPPs cytotoxicity, ROS and NO production, inducible nitric oxide synthase expression, NO scavenging, and antioxidant properties of LPPs, respectively. Our study shows that the cytotoxic action of acrolein and 4-hydroxynonenal works in a dose- and time-dependent manner. Further, our results imply that acrolein, 4-hydroxynonenal, and malondialdehyde can inhibit, to a different degree, ROS and NO production in stimulated macrophages, partially independently of their toxic effect. Also, changes in enzymatic pathways (especially NADPH-oxidase and nitric oxide synthase inhibition) and NO scavenging properties are included in the downregulation of reactive species formation. Copyright © 2010 Elsevier Ltd. All rights reserved.

Sodium tripolyphosphate cross-linked chitosan based sensor for enhacing sensing properties towards acetone

Science.gov (United States)

Nasution, T. I.; Asrosa, R.; Nainggolan, I.; Balyan, M.; Indah, R.; Wahyudi, A.

2018-02-01

In this report, sensing properties of sodium tripolyphosphate (TPP) cross-linked chitosan based sensor has been successfully enhanced towards acetone. Chitosan solutions were cross-linked with sodium TPP in variation of 0.1%, 0.5%, 1% and 1.5% w/v, respectively. The sensors were fabricated in film form using an electrochemical deposition method. The sensing properties of the sensors were observed by exposing the pure chitosan and sodium TPP cross-linked chitosan sensors towards acetone concentrations of 5, 10, 50, 100 and 200 ppm. The measurement results revealed that the maximum response in output voltage value of pure chitosan sensor was 0.35 V while sodium TPP crosslinked chitosan sensors were above 0.35 V towards 5 ppm acetone concentration. When the sensors were exposed towards acetone concentration of 200 ppm, the maximum response of pure chitosan was 0.45 V while sodium TPP crosslinked chitosan sensors were above 0.45 V. Amongst the variation of sodium TPP, the maximum response of 1% sodium TPP was the highest since the maximum response was 0.4 V and 0.6 V towards 5 ppm and 200 ppm acetone concentration, respectively. While the maximum responses of other sodium TPP concentrations were under 0.4 V and 0.6 V towards 5 ppm and 200 ppm acetone concentration. Moreover, 1% sodium TPP cross-linked chitosan based sensor showed good reproducibility and outstanding lifetime. Therefore, 1% sodium TPP cross-linked chitosan based sensor has exhibited remarkable sensing properties as a novel acetone sensor.

Lipid peroxidation in liver homogenates. Effects of membrane lipid composition and irradiation

International Nuclear Information System (INIS)

Vaca, C.; Ringdahl, M.H.

1984-01-01

The rate of lipid peroxidation has been followed in whole liver homogenates from mice using the TBA-method. Liver homogenates with different membrane fatty acid composition were obtained from mice fed diets containing different sources of fat i.e. sunflower seed oil (S), coconut oil (C) and hydrogenated lard (L). The yields of the TBA-chromophore (TBA-c) were 4 times higher in the liver homogenates S compared to C and L after 4 hour incubation at 37 0 C. Irradiation of the liver homogenates before incubation inhibited the formation of lipid peroxidation products in a dose dependent way. The catalytic capacity of the homogenates was investigated, followed as the autooxidation of cysteamine or modified by addition of the metal chelator EDTA. The rate of autooxidation of cysteamine, which is dependent on the presence of metal ions (Fe/sup 2+/ or Cu/sup 2+/), was decreased with increasing dose, thus indicating an alteration in the availability of metal catalysts in the system. The addition of Fe/sup 2+/ to the system restored the lipid peroxidation yields in the irradiated systems and the presence of EDTA inhibited the formation of lipid peroxidation products in all three dietary groups. It is suggested that irradiation alters the catalytic activity needed in the autooxidation processes of polyunsaturated fatty acids

Interactions of ionic liquids and acetone: thermodynamic properties, quantum-chemical calculations, and NMR analysis.

Science.gov (United States)

Ruiz, Elia; Ferro, Victor R; Palomar, Jose; Ortega, Juan; Rodriguez, Juan Jose

2013-06-20

The interactions between ionic liquids (ILs) and acetone have been studied to obtain a further understanding of the behavior of their mixtures, which generally give place to an exothermic process, mutual miscibility, and negative deviation of Raoult's law. COSMO-RS was used as a suitable computational method to systematically analyze the excess enthalpy of IL-acetone systems (>300), in terms of the intermolecular interactions contributing to the mixture behavior. Spectroscopic and COSMO-RS results indicated that acetone, as a polar compound with strong hydrogen bond acceptor character, in most cases, establishes favorable hydrogen bonding with ILs. This interaction is strengthened by the presence of an acidic cation and an anion with dispersed charge and non-HB acceptor character in the IL. COSMO-RS predictions indicated that gas-liquid and vapor-liquid equilibrium data for IL-acetone systems can be finely tuned by the IL selection, that is, acting on the intermolecular interactions between the molecular and ionic species in the liquid phase. NMR measurements for IL-acetone mixtures at different concentrations were also carried out. Quantum-chemical calculations by using molecular clusters of acetone and IL species were finally performed. These results provided additional evidence of the main role played by hydrogen bonding in the behavior of systems containing ILs and HB acceptor compounds, such as acetone.

Anion exchange behavior of Ti, Zr, Hf, Nb and Ta as homologues of Rf and Db in mixed HF-acetone solutions

International Nuclear Information System (INIS)

Aksenov, N.V.; Bozhikov, G.A.; Starodub, G.Ya.; Dmitriev, S.N.; Filosofov, D.V.; Jon Sun Jin; Radchenko, V.I.; Lebedev, N.A.; Novgorodov, A.F.

2009-01-01

We studied in detail the sorption behavior of Ti, Zr, Hf, Nb and Ta on AG 1 anion exchange resin in HF-acetone mixed solutions as a function of organic cosolvent and acid concentrations. Anion exchange behavior was found to be strongly acetone concentration dependent. The distribution coefficients of Ti, Zr, Hf and Nb increased and those of Ta decreased with increasing content of acetone in HF solutions. With increasing HF concentration, anion exchange equilibrium analysis indicated the formation of fluoride complexes of group-4 elements with charge -3 and Ta with charge -2. For Nb the slope of -2 increased up to -5. Optimal conditions for separation of the elements using AIX chromatography were found. Group-4 elements formed MF 7 3- (M = Ti, Zr, Hf) complexes whose sorption decreased Ti > Hf > Zr in reverse order of complex stability. This fact is of particular interest for studying ion exchange behavior of Rf compared to Ti. The advantages of studying chemical properties of Rf and Db in aqueous HF solutions mixed with organic solvents are briefly discussed

Critical assessment of the formation of hydrogen peroxide in dough by fermenting yeast cells.

Science.gov (United States)

Rezaei, Mohammad N; Dornez, Emmie; Verstrepen, Kevin J; Courtin, Christophe M

2015-02-01

Fermentation of bread dough leads to strengthening of the dough matrix. This effect has previously been ascribed to the action of hydrogen peroxide (H2O2) produced by yeast in dough. In this study, we re-evaluate the production of H2O2 by yeast in dough and aqueous fermentation broth. Results show that the previously reported high levels of H2O2 in fermenting dough were most probably due to the lack of specificity of the potassium dichromate/acetic acid-based method used. Using the chemiluminescent HyPerBlu assay, no yeast H2O2 production could be detected in fermented dough or broth. Even though the formation of low levels of H2O2 cannot be ruled out due to the presence of catalase in flour and the fast reaction of H2O2 with gluten proteins, our results suggest that the changes in dough matrix rheological properties upon fermentation are not due to production of H2O2 by yeast. Copyright © 2014 Elsevier Ltd. All rights reserved.

Self-Associating Behavior of Acetone in Liquid Krypton.

Science.gov (United States)

De Beuckeleer, Liene I; Herrebout, Wouter A

2016-02-18

Acetone molecules are inclined to self-associate through dipole-dipole interactions because of their large dipole moment. Infrared spectroscopy of compounds dissolved in liquid noble gases supported by high level ab initio calculations allows investigating the self-associating behavior and determining the thermodynamical properties. In this study, infrared spectra of various concentrations of acetone dissolved in liquid krypton are recorded at constant temperature. Overlapping monomer and dimer spectra are separated by analyzing the obtained data sets with numerical methods based on least-squares fitting. Although acetone is known to self-associate, only a few spectral features have been presented in literature before. In this study, the application of new numerical approaches succeeds in resolving overlapping spectra and allows observing isolated acetone dimer absorption bands for the complete mid infrared spectrum. By use of data sets of spectra recorded at temperatures between 134 and 142 K, the experimental standard dimerization enthalpy was determined to be -10.8 kJ mol(-1). MP2/aug-cc-pVDZ calculations predicted a stacked and planar dimer geometry of which the stacked geometry is more stable. Combining MP2 energies and single point corrections involving CCSD(T) calculations and complete basis set extrapolations based on the MP2/aug-cc-pVDZ equilibrium geometry lead to complexation energy of -28.4 kJ mol(-1) for the stacked geometry and -15.1 kJ mol(-1) for the planar geometry. The corresponding values for the complexation enthalpies in solution, obtained by combining these values with corrections for thermal and solvent influences are -13.7 and -5.8 kJ mol(-1).

Production of uranium peroxide

International Nuclear Information System (INIS)

Caropreso, F.E.; Kreuz, D.F.

1977-01-01

A process is claimed of recovering uranium values as uranium peroxide from an aqueous uranyl solution containing dissolved vanadium and sodium impurities by treating the uranyl solution with hydrogen peroxide in an amount sufficient to have an excess of at least 0.5 parts H 2 O 2 per part of vanadium (V 2 O 5 ) above the stoichiometric amount required to form the uranium peroxide, the hydrogen peroxide treatment is carried out in three sequential phases consisting of I, a precipitation phase in which the hydrogen peroxide is added to the uranyl solution to precipitate the uranium peroxide and the pH of the reaction medium maintained in the range of 2.5 to 5.5 for a period of from about 1 to 60 minutes after the hydrogen peroxide addition; II, a digestion phase in which the pH of the reaction medium is maintained in the range of 3.0 to 7.0 for a period of about 5 to 180 minutes and III, a final phase in which the pH of the reaction medium is maintained in the range of 4.0 to 7.0 for a period of about 1 to 60 minutes during which time the uranium peroxide is separated from the reaction solution containing the dissolved vanadium and sodium impurities. The excess hydrogen peroxide is maintained during the entire treatment up until the uranium peroxide is separated from the reaction medium

Conditioned Place Preference to Acetone Inhalation and the Effects on Locomotor Behavior and 18FDG Uptake

Energy Technology Data Exchange (ETDEWEB)

Pai, J.C.; Dewey, S.L.; Schiffer, W.; Lee, D.

2006-01-01

Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [18F]2-fluorodeoxy-D-glucose (18FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with 18FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p<0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of 18FDG uptake following

Purification and Characterization of the Acetone Carboxylase of Cupriavidus metallidurans Strain CH34

Science.gov (United States)

Rosier, Caroline; Leys, Natalie; Henoumont, Céline; Mergeay, Max

2012-01-01

Acetone carboxylase (Acx) is a key enzyme involved in the biodegradation of acetone by bacteria. Except for the Helicobacteraceae family, genome analyses revealed that bacteria that possess an Acx, such as Cupriavidus metallidurans strain CH34, are associated with soil. The Acx of CH34 forms the heterohexameric complex α2β2γ2 and can carboxylate only acetone and 2-butanone in an ATP-dependent reaction to acetoacetate and 3-keto-2-methylbutyrate, respectively. PMID:22492439

[The effect of monensin, tiamulin and the simultaneous administration of both substances on the microsomal mixed function oxidases and on the peroxide formation in broilers].

Science.gov (United States)

Laczay, P; Simon, F; Lehel, J

1990-09-01

The influence of Monensin, Tiamulin and the simultaneous administration of the two substances on the microsomal, mixed function oxidases was studied on cockerels. Monensin was seen to cause a slight depression in the amount of cytochrome P-450 and cytochrome b5 as well as in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and p-nitroanisole-O-demethylase. Tiamulin induced a moderate increase in the amount of cytochrome P-450 and in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and aminopyrine-N-demethylase. The combined administration of monensin and tiamulin resulted in marked induction of the microsomal enzymes; the amount of cytochrome P-450 reduced by metyrapone or carbon monoxide increased 2.5 or 2-times, respectively, and the activities of the tested microsomal hydroxylases and demethylases showed also an expressed increase. At the same time the formation of lipid peroxides also markedly increased and the GSH concentration was reduced. In conclusion, the results of the investigations indicate that the simultaneous application of monensin and tiamulin cause a marked induction of the drug-metabolizing microsomal enzymes and a significant increase in the lipid peroxide formation.

A fully integrated standalone portable cavity ringdown breath acetone analyzer

Science.gov (United States)

Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

2015-09-01

Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

A fully integrated standalone portable cavity ringdown breath acetone analyzer.

Science.gov (United States)

Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

2015-09-01

Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

Change of Exhaled Acetone Concentration in a Diabetic Patient with Acute Decompensated Heart Failure.

Science.gov (United States)

Yokokawa, Tetsuro; Ichijo, Yasuhiro; Houtsuki, Yu; Matsumoto, Yoshiyuki; Oikawa, Masayoshi; Yoshihisa, Akiomi; Sugimoto, Koichi; Nakazato, Kazuhiko; Suzuki, Hitoshi; Saitoh, Shu-Ichi; Shimouchi, Akito; Takeishi, Yasuchika

2017-10-21

In heart failure patients, exhaled acetone concentration, a noninvasive biomarker, is increased according to heart failure severity. Moreover, exhaled acetone concentration is also known to be affected by diabetes mellitus. However, there have been no reports on exhaled acetone concentration in heart failure patients with diabetes mellitus. A 77-year old man was admitted to our hospital with acute decompensated heart failure and atrioventricular block. He had controlled diabetes mellitus under insulin treatment with hemoglobin A1c of 6.5%. He underwent treatment of diuretics and permanent pacemaker implantation. His condition improved and he was discharged at Day 12. Due to the heart failure improvement, his levels of exhaled acetone concentration decreased from 1.623 ppm at admission to 0.664 ppm at discharge. This is the first report to reveal a change of exhaled acetone concentration in a diabetic patient with acute decompensated heart failure.

Hydrogen peroxide safety issues

International Nuclear Information System (INIS)

Conner, W.V.

1993-01-01

A literature survey was conducted to review the safety issues involved in handling hydrogen peroxide solutions. Most of the information found in the literature is not directly applicable to conditions at the Rocky Flats Plant, but one report describes experimental work conducted previously at Rocky Flats to determine decomposition reaction-rate constants for hydrogen peroxide solutions. Data from this report were used to calculate decomposition half-life times for hydrogen peroxide in solutions containing several decomposition catalysts. The information developed from this survey indicates that hydrogen peroxide will undergo both homogeneous and heterogeneous decomposition. The rate of decomposition is affected by temperature and the presence of catalytic agents. Decomposition of hydrogen peroxide is catalyzed by alkalies, strong acids, platinum group and transition metals, and dissolved salts of transition metals. Depending upon conditions, the consequence of a hydrogen peroxide decomposition can range from slow evolution of oxygen gas to a vapor, phase detonation of hydrogen peroxide vapors

Cross-linking of LDPE/wax blends by using dicumyl peroxide

African Journals Online (AJOL)

Igor Krupa

They are not soluble in many solvents due to their high crystallinity, but they ... macroradical formation via thermal decomposition of organic peroxides.6,7,8 A ... as potential applications of LDPE/wax blends are concerned, lower viscosity of ...

Sensing behavior of acetone vapors on TiO_2 nanostructures — application of density functional theory

Directory of Open Access Journals (Sweden)

V. Nagarajan

2017-12-01

Full Text Available The electronic properties of TiO_2 nanostructure are explored using density functional theory. The adsorption properties of acetone on TiO_2 nanostructure are studied in terms of adsorption energy, average energy gap variation and Mulliken charge transfer. The density of states spectrum and the band structure clearly reveals the adsorption of acetone on TiO_2 nanostructures. The variation in the energy gap and changes in the density of charge are observed upon adsorption of acetone on n-type TiO_2 base material. The results of DOS spectrum reveal that the transfer of electrons takes place between acetone vapor and TiO_2 base material. The findings show that the adsorption property of acetone is more favorable on TiO_2 nanostructure. Suitable adsorption sites of acetone on TiO_2 nanostructure are identified at atomistic level. From the results, it is confirmed that TiO_2 nanostructure can be efficiently utilized as a sensing element for the detection of acetone vapor in a mixed environment.

(Ternary liquid + liquid) equilibria for (water + acetone + α-pinene, or β-pinene, or limonene) mixtures

International Nuclear Information System (INIS)

Li Xiaoli; Tamura, Kazuhiro

2010-01-01

(Ternary liquid + liquid) equilibria (tie-lines) of (water + acetone + α-pinene) at T = (288.15, 298.15, and 308.15) K and (water + acetone + β-pinene, or limonene) at T = 298.15 K have been measured. The experimental (ternary liquid + liquid) equilibrium data have been correlated successfully by the original UNIQUAC and modified UNIQUAC models. The modified UNIQUAC model reproduced accurately the experimental results for the (water + acetone + α-pinene) system at all the temperatures but fairly agreed with the experimental data for the (water + acetone + β-pinene, or limonene) systems.

Sol – Gel synthesis and characterization of magnesium peroxide nanoparticles

International Nuclear Information System (INIS)

Jaison, J; Chan, Y S; Ashok raja, C; Balakumar, S

2015-01-01

Magnesium peroxide is an excellent source of oxygen in agriculture applications, for instance it is used in waste management as a material for soil bioremediation to remove contaminants from polluted underground water, biological wastes treatment to break down hydrocarbon, etc. In the present study, sol-gel synthesis of magnesium peroxide (MgO 2 ) nanoparticles is reported. Magnesium peroxide is odourless; fine peroxide which releases oxygen when reacts with water. During the sol-gel synthesis, the magnesium malonate intermediate is formed which was then calcinated to obtain MgO 2 nanoparticles. The synthesized nanoparticles were characterized using Thermo gravimetric -Differential Thermal Analysis (TG- DTA), X-Ray Diffraction studies (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Our study provides a clear insight that the formation of magnesium malonate during the synthesis was due to the reaction between magnesium acetate, oxalic acid and ethanol. In our study, we can conclude that the calcination temperature has a strong influence on particle size, morphology, monodispersity and the chemistry of the particles. (paper)

A two-stage combined trickle bed reactor/biofilter for treatment of styrene/acetone vapor mixtures.

Science.gov (United States)

Vanek, Tomas; Halecky, Martin; Paca, Jan; Zapotocky, Lubos; Gelbicova, Tereza; Vadkertiova, Renata; Kozliak, Evguenii; Jones, Kim

2015-01-01

Performance of a two-stage biofiltration system was investigated for removal of styrene-acetone mixtures. High steady-state acetone loadings (above C(in)(Ac) = 0.5 g.m(-3) corresponding to the loadings > 34.5 g.m(-3).h(-1)) resulted in a significant inhibition of the system's performance in both acetone and styrene removal. This inhibition was shown to result from the acetone accumulation within the upstream trickle-bed bioreactor (TBR) circulating mineral medium, which was observed by direct chromatographic measurements. Placing a biofilter (BF) downstream to this TBR overcomes the inhibition as long as the biofilter has a sufficient bed height. A different kind of inhibition of styrene biodegradation was observed within the biofilter at very high acetone loadings (above C(in)(Ac) = 1.1 g.m(-3) or 76 g.m(-3).h(-1) loading). In addition to steady-state measurements, dynamic tests confirmed that the reactor overloading can be readily overcome, once the accumulated acetone in the TBR fluids is degraded. No sizable metabolite accumulation in the medium was observed for either TBR or BF. Analyses of the biodegradation activities of microbial isolates from the biofilm corroborated the trends observed for the two-stage biofiltration system, particularly the occurrence of an inhibition threshold by excess acetone.

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

Energy Technology Data Exchange (ETDEWEB)

Wilbraham, Richard J., E-mail: r.wilbraham@lancaster.ac.uk [The Lloyd’s Register Foundation Centre for Nuclear Engineering, Engineering Department, Lancaster University, Bailrigg, Lancashire LA1 4YR (United Kingdom); Boxall, Colin, E-mail: c.boxall@lancaster.ac.uk [The Lloyd’s Register Foundation Centre for Nuclear Engineering, Engineering Department, Lancaster University, Bailrigg, Lancashire LA1 4YR (United Kingdom); Goddard, David T., E-mail: dave.t.goddard@nnl.co.uk [National Nuclear Laboratory, Preston Laboratory, Springfields, Preston, Lancashire PR4 0XJ (United Kingdom); Taylor, Robin J., E-mail: robin.j.taylor@nnl.co.uk [National Nuclear Laboratory, Central Laboratory, Seascale, Cumbria CA20 1PG (United Kingdom); Woodbury, Simon E., E-mail: simon.woodbury@nnl.co.uk [National Nuclear Laboratory, Central Laboratory, Seascale, Cumbria CA20 1PG (United Kingdom)

2015-09-15

Highlights: • The first report of the presence of both UO{sub 2} and polymeric UO{sub 2}{sup 2+} in the same electrodeposited U oxide sample. • The action of H{sub 2}O{sub 2} on electrodeposited U oxides is described using corrosion based concepts. • Electrodeposited U oxide freely dissolves at hydrogen peroxide concentrations <100 μmol dm{sup −3}. • At [H{sub 2}O{sub 2}] > 0.1 mmol dm{sup −3} dissolution is inhibited by formation of a studtite passivation layer. • At [H{sub 2}O{sub 2}] ⩾ 1 mol dm{sup −3} studtite formation competes with uranyl–peroxide complex formation. - Abstract: 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 H{sub 2}O{sub 2}-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 [H{sub 2}O{sub 2}] ⩽ 100 μmol dm{sup −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 H{sub 2}O{sub 2} concentrations between 1 mmol dm{sup −3} and 0.1 mol dm{sup −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 [H{sub 2}O{sub 2}] > 0.1 mol dm{sup −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 UO{sub 2} films has not hitherto been observed or explored, either in terms

Formation of water-soluble soybean polysaccharides from spent flakes by hydrogen peroxide treatment

DEFF Research Database (Denmark)

Pierce, Brian; Wichmann, Jesper; Tran, Tam H.

2016-01-01

70% of the original insoluble material as high molar mass soluble polysaccharides. A design of experiment was used to quantify the effects of pH, reaction time, and hydrogen peroxide concentration on the reaction yield, average molar mass, and free monosaccharides generated. The resulting product......In this paper we propose a novel chemical process for the generation of water-soluble polysaccharides from soy spent flake, a by-product of the soy food industry. This process entails treatment of spent flake with hydrogen peroxide at an elevated temperature, resulting in the release of more than...... is low in protein, fat, and minerals and contains predominantly water-soluble polysaccharides of high molar mass, including arabinan, type I arabinogalactan, homogalacturonan, xyloglucan, rhamnogalacturonan, and (glucurono)arabinoxylan. This treatment provides a straightforward approach for generation...

Algerian mint species：high performance thin layer chromatography quantitative determination of rosmarinic acid and in vitro inhibitory effects on linoleic acid peroxidation

Institute of Scientific and Technical Information of China (English)

Brahmi Fatiha; Madani Khodir; Stvigny Caroline; Chibane Mohamed; Duez Pierre

2014-01-01

Objective: To determine the quantitative paremeters of rosmarinic acid in Algerian mints,Mentha spicata L. (M. spicata), Mentha pulegium L. and Mentha rotundifolia (L.) Huds by high performance thin layer chromatography (HPTLC)-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation.Methods:The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform:acetone: formic acid (75:16.5:8.5, v/v) as the mobile phase. Rosmarinic acid was determined in UV at 365 nm and fluorescence at λexc 325 nm with a 550 nm filter, respectively. The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method.Results:Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1000 ng/spot. M. spicata was found to contain significantly higher concentrations of rosmarinic acid. The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision (total precision for Mentha spp extracts, 5.1% and 5.8% for UV and fluorescence detection, respectively). The HPTLC data, allied to assays of linoleic acid peroxidation prevention, suggested the potential of M. spicata (52% Trolox®equivalents) as a natural source for inhibitors of lipid peroxidation.Conclusions:Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species.

Algerian mint species: high performance thin layer chromatography quantitative determination of rosmarinic acid and in vitro inhibitory effects on linoleic acid peroxidation

Directory of Open Access Journals (Sweden)

Brahmi Fatiha

2014-12-01

Full Text Available Objective: To determine the quantitative paremeters of rosmarinic acid in Algerian mints, Mentha spicata L. (M. spicata, Mentha pulegium L. and Mentha rotundifolia (L. Huds by high performance thin layer chromatography (HPTLC-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation. Methods: The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform: acetone: formic acid (75:16.5:8.5, v/v as the mobile phase. Rosmarinic acid was determined in UV at 365 nm and fluorescence at λexc 325 nm with a 550 nm filter, respectively. The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method. Results: Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1 000 ng/spot. M. spicata was found to contain significantly higher concentrations of rosmarinic acid. The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision (total precision for Mentha spp extracts, 5.1% and 5.8% for UV and fluorescence detection, respectively. The HPTLC data, allied to assays of linoleic acid peroxidation prevention, suggested the potential of M. spicata (52% Trolox® equivalents as a natural source for inhibitors of lipid peroxidation. Conclusions: Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species.

Reactivity of lignin and lignin models towards UV-assisted peroxide

International Nuclear Information System (INIS)

Sun, Y.P.; Wallis, A.F.A.; Nguyen, K.L.

1997-01-01

The comparative reactivities of a series of guaiacyl and syringyl lignin model compounds and their methylated analogues towards alkaline peroxide and UV-alkaline peroxide were investigated. The overall reaction was followed by monitoring the reduction of the substrate as a function of time, and in every case, the reaction showed pseudo-first-order kinetics. The reaction rates of most lignin models having identical sidechains with alkaline peroxide and with UV-alkaline peroxide were in the order syringyl guaiacyl 3,4,5-trimethoxyphenyl veratryl. Thus phenols react faster than their methyl ethers, and an extra ortho methoxyl group promotes the reaction. Lignin models possessing electron-donating sidechains had generally higher reaction rates than those with electron-withdrawing sidechains. The reaction rates of the series of benzoic acids were 2-4 times higher at pH 11 than at pH 5. UV-peroxide degradation of a eucalypt kraft lignin was faster than that of a pine kraft lignin, and degradation was 1.4-1.6 times faster at pH 11 than at pH 5. The data are consistent with the formation of higher amounts of reactive radicals under alkaline conditions, and aromatic rings with greater electronegativities promoting reactions with the radicals

Aluminum induces lipid peroxidation and aggregation of human blood platelets

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T.J.C. Neiva

1997-05-01

Full Text Available Aluminum (Al3+ intoxication is thought to play a major role in the development of Alzheimer's disease and in certain pathologic manifestations arising from long-term hemodialysis. Although the metal does not present redox capacity, it can stimulate tissue lipid peroxidation in animal models. Furthermore, in vitro studies have revealed that the fluoroaluminate complex induces diacylglycerol formation, 43-kDa protein phosphorylation and aggregation. Based on these observations, we postulated that Al3+-induced blood platelet aggregation was mediated by lipid peroxidation. Using chemiluminescence (CL of luminol as an index of total lipid peroxidation capacity, we established a correlation between lipid peroxidation capacity and platelet aggregation. Al3+ (20-100 µM stimulated CL production by human blood platelets as well as their aggregation. Incubation of the platelets with the antioxidants nor-dihydroguaiaretic acid (NDGA (100 µM and n-propyl gallate (NPG (100 µM, inhibitors of the lipoxygenase pathway, completely prevented CL and platelet aggregation. Acetyl salicylic acid (ASA (100 µM, an inhibitor of the cyclooxygenase pathway, was a weaker inhibitor of both events. These findings suggest that Al3+ stimulates lipid peroxidation and the lipoxygenase pathway in human blood platelets thereby causing their aggregation

The results of the lipids peroxidation products on the DNA bases as biological markers of the oxidative stress

International Nuclear Information System (INIS)

Falletti, O.

2007-10-01

Different ways of DNA damages have been studied, among these ones the direct way of DNA damages formation by the reactive oxygen species (R.O.S.). This way leads to the formation of oxidative DNA damages. In 1990, works have suggested an indirect way of DNA damages formation, the lipids peroxidation. Instead of oxidizing directly DNA, the R.O.S. oxide the lipids present in the cells and their membranes; The products coming from this degradation are able to provoke DNA damages. This way has not been studied very much. The work of this thesis is axed on this DNA theme and lipids peroxidation. In the first chapter, we begin by presenting DNA and the direct way of oxidative damages formation by the R.O.S.Then, we speak about the cell lipids suffering oxidation reactions and the different ways of lipids oxidation. Then, we present how the lipid peroxidation is a source of damages for DNA. (N.C.)

Skin barrier disruption by acetone: observations in a hairless mouse skin model

NARCIS (Netherlands)

Rissmann, R.; Oudshoorn, M.H.M.; Hennink, W.E.; Ponec, M.; Bouwstra, J.A.

2009-01-01

To disrupt the barrier function of the skin, different in vivo methods have been established, e.g., by acetone wiping or tape-stripping. In this study, the acetone-induced barrier disruption of hairless mice was investigated in order to establish a reliable model to study beneficial, long-term

Dual role of beta-carotene in combination with cigarette smoke aqueous extract on the formation of mutagenic lipid peroxidation products in lung membranes: dependence on pO2.

Science.gov (United States)

Palozza, P; Serini, S; Trombino, S; Lauriola, L; Ranelletti, F O; Calviello, G

2006-12-01

Results from some intervention trials indicated that supplemental beta-carotene enhanced lung cancer incidence and mortality in chronic smokers. The aim of this study was to verify the hypothesis that high concentrations of the carotenoid, under the pO2 present in lung (100-150 mmHg), may exert deleterious effects through a prooxidant mechanism. To test this hypothesis, we examined the interactions of beta-carotene and cigarette smoke condensate (tar) on the formation of lipid peroxidation products in rat lung microsomal membranes enriched in vitro with varying beta-carotene concentrations (from 1 to 10 nmol/mg prot) and then incubated with tar (6-25 microg/ml) under different pO2. As markers of lipid peroxidation, we evaluated the levels of conjugated dienes and malondialdehyde, possessing mutagenic and pro-carcinogenic activity. The exposure of microsomal membranes to tar induced a dose-dependent enhancement of lipid peroxidation, which progressively increased as a function of pO2. Under a low pO2 (15 mmHg), beta-carotene acted clearly as an antioxidant, inhibiting tar-induced lipid peroxidation. However, the carotenoid progressively lost its antioxidant efficiency by increasing pO2 (50-100 mmHg) and acted as a prooxidant at pO2 ranging from 100 to 760 mmHg in a dose-dependent manner. Consistent with this finding, the addition of alpha-tocopherol (25 microM) prevented the prooxidant effects of the carotenoid. beta-Carotene auto-oxidation, measured as formation of 5,6-epoxy-beta,beta-carotene, was faster at high than at low pO2 and the carotenoid was more rapidly consumed in the presence of tar. These data point out that the carotenoid may enhance cigarette smoke-induced oxidative stress and exert potential deleterious effects at the pO2 normally present in lung tissue.

Effect of acetone accumulation on structure and dynamics of lipid membranes studied by molecular dynamics simulations.

Science.gov (United States)

Posokhov, Yevgen O; Kyrychenko, Alexander

2013-10-01

The modulation of the properties and function of cell membranes by small volatile substances is important for many biomedical applications. Despite available experimental results, molecular mechanisms of action of inhalants and organic solvents, such as acetone, on lipid membranes remain not well understood. To gain a better understanding of how acetone interacts with membranes, we have performed a series of molecular dynamics (MD) simulations of a POPC bilayer in aqueous solution in the presence of acetone, whose concentration was varied from 2.8 to 11.2 mol%. The MD simulations of passive distribution of acetone between a bulk water phase and a lipid bilayer show that acetone favors partitioning into the water-free region of the bilayer, located near the carbonyl groups of the phospholipids and at the beginning of the hydrocarbon core of the lipid membrane. Using MD umbrella sampling, we found that the permeability barrier of ~0.5 kcal/mol exists for acetone partitioning into the membrane. In addition, a Gibbs free energy profile of the acetone penetration across a bilayer demonstrates a favorable potential energy well of -3.6 kcal/mol, located at 15-16Å from the bilayer center. The analysis of the structural and dynamics properties of the model membrane revealed that the POPC bilayer can tolerate the presence of acetone in the concentration range of 2.8-5.6 mol%. The accumulation of the higher acetone concentration of 11.2 mol% results, however, in drastic disordering of phospholipid packing and the increase in the membrane fluidity. The acetone molecules push the lipid heads apart and, hence, act as spacers in the headgroup region. This effect leads to the increase in the average headgroup area per molecule. In addition, the acyl tail region of the membrane also becomes less dense. We suggest, therefore, that the molecular mechanism of acetone action on the phospholipid bilayer has many common features with the effects of short chain alcohols, DMSO, and

The Influence of PEG400 and Acetone on Polysulfone Membrane Morphology and Fouling Behaviour

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P.T.P. Aryanti

2016-05-01

Full Text Available Modification of polysulfone ultrafiltration membrane was conducted by blending polysulfone with PEG400 and acetone as additives. The influence of each additive on the resulted membrane morphology and fouling characteristics were investigated. The experimental results showed that the hydrophilicity of the polysulfone membrane was improved by the increase of PEG400 in the polysulfone membrane. The water contact angle of the membrane was decreased from 76.1° to 38.31° when 35 %wt of PEG400 was added into the polysulfone solution, while the water content of the membrane was increased by around 38%. The high concentration of PEG400 in the polysulfone solution led to the formation of longer finger-like cavities in the membrane structure and resulted in a thicker membrane skin layer. The high concentration of PEG400 also contributed to the increase in hydraulic resistance of the membrane due to organic matter fouling. This problem could be minimized by the addition of acetone into the polysulfone solution, which resulted in a lower fouling resistance of organic matter during up to five hours of peat water filtration.

Gadolinium-, Calcium-, copper- and zirc complexes with riboflavin in acetone and acetonitrile

International Nuclear Information System (INIS)

Lugina, L.N.; Romanenko, V.I.; Davidenko, N.K.

1983-01-01

Using the methods of solubility and spectrophotometry, stability copstants Of complexes RFMSSUp(n+) (RF=riboflavin, Mnsup(n+)=Cdsup(3+), Ca 2+ , Cu 2+ and Zn 2+ ) in acetone and acetonitrile against the background of 1 mol/l LiClO 4 x3H 2 O have been determined. It was found that stability of copper and zinc complexes with riboflavin in acetone is higher than in acetonitrile, whereas the stability of gadolinium and calcium complexes, on the contrary, is higher in acetonitrile than in acetone. It is shown that the character of the absorption spectrum change of riboflavin in complexing with metal ions depends on the nature of coordinating cation

N,N,N′,N′,N′′-Pentamethyl-N′′-[2-(trimethylazaniumylethyl]guanidinium bis(tetraphenylborate acetone monosolvate

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Ioannis Tiritiris

2016-02-01

Full Text Available The asymmetric unit of the title solvated salt, C11H28N42+·2C24H20B−·C3H6O, comprises two cations, four tetraphenylborate anions and two acetone molecules. One cation shows an orientational disorder at the CN3 moiety and two sets of N-atom positions were found related by a 60° rotation, with a refined occupancy ratio of 0.935 (1:0.065 (1. The respective nitrogen-bonded –CH2 and –CH3 groups are included in the disorder model. The C—N bond lengths in the central CN3 units of both guanidinium ions range between 1.3329 (17 and 1.364 (16 Å, indicating a degree of double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal–planar geometry and one positive charge is delocalized in the CN3 plane. The C—N bond lengths in the terminal trimethylammonium groups have values close to a typical single bond, and the second positive charge is localized there. In the crystal, the guanidinium ions are connected by C—H...O hydrogen bonds with the acetone molecules. C—H...π interactions are present between the guanidinium and acetone hydrogen atoms and the phenyl rings of the tetraphenylborate ions, leading to the formation of a two-dimensional supramolecular pattern along the bc plane.

Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

Science.gov (United States)

Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

2016-09-30

A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well. Copyright © 2016 Elsevier B.V. All rights reserved.

STUDY OF AZOSPIRILLUM LECTINS INFLUENCE ON HYDROGEN PEROXIDE PRODUCTION IN WHEAT-ROOTS

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Alen’kina S.A.

2009-12-01

Full Text Available It was found that two cell-surface lectins isolated from the nitrogen-fixing soil bacterium Azospirillum brasilense Sp7 and from its mutant defective in lectin activity, A. brasilense Sp7.2.3 can stimulate rapid formation of hydrogen peroxide, associated with an increase in the activities of oxalate oxidase and peroxidase in the roots of wheat seedlings. The most advantageous and most rapidly induced pathway of hydrogen peroxide formation was the oxidation of oxalic acid by oxalate oxidase because in this case, a 10-min treatment of the roots with the lectins at 10 µg ml-1 was sufficient. The data from this study attest that the Azospirillum lectins can act as inducers of adaptation processes in the roots of wheat seedlings.

Interaction of red pepper (Capsicum annum, Tepin) polyphenols with Fe(II)-induced lipid peroxidation in brain and liver

International Nuclear Information System (INIS)

Oboh, G.; Rocha, J.B.T.

2006-03-01

Polyphenols exhibit a wide range of biological effects because of their antioxidant properties. Several types of polyphenols (phenolic acids, hydrolyzable tannins, and flavonoids) show anticarcinogenic and antimutagenic effects. Comparative studies were carried on the protective ability of free and bound polyphenol extracts of red Capsicum annuum Tepin (CAT) on brain and liver - In vitro. Free polyphenols of red Capsicum annuum Tepin (CAT) were extracted with 80% acetone, while the bound polyphenols were extracted with ethyl acetate from acid and alkaline hydrolysis of the pepper residue from free polyphenols extract. The phenol content, Fe (II) chelating ability, OH radical scavenging ability and protective ability of the extract against Fe (II)-induced lipid peroxidation in brain and liver was subsequently determined. The results of the study revealed that the free polyphenols (218.2mg/100g) content of the pepper were significantly higher than the bound polyphenols (42.5mg/100g). Furthermore, the free polyphenol extract had a significantly higher ( 2+ induced lipid peroxidation, and this is probably due to the higher Fe (II) chelating ability and OH radical scavenging ability of the free polyphenols from the pepper. (author)

Oscillatory bromate-oxalic acid-Ce-acetone-sulfuric acid reaction, in CSTR

International Nuclear Information System (INIS)

Pereira, Janaina A.M.; Faria, Roberto B.

2004-01-01

Periodic oscillations were observed for the first time, in a CSTR, in the system bromate-oxalic acid-Ce(IV)-acetone-sulfuric acid, in a CSTR. A reaction between Ce(IV) and acetone, until now not described in the literature and occurring before the addition of the reagents to the reactor, was identified as a decisive factor for the appearing of the regular oscillations. (author)

Kinetic features of cadmium electrodeposition in iodide water-acetone electrolytes

International Nuclear Information System (INIS)

Kuznetsov, V.V.; Skibina, L.M.; Khalikov, R.R.

2006-01-01

Based on the data of chronopotentiometric, galvanostatic, potentiodynamic, and impedance measurements, the composition of aqueous acetone electrolyte is studied for its effect on the rate of cadmium(II) electroreduction in iodide media. The adsorption of I - ions on the cadmium cathode surface is shown to depend on the interaction mechanism between the components of water-acetone mixtures. During a competitive adsorption of anions and organic solvent molecules, this affects the mechanism and the rate of electrodeposition and also the coating quality [ru

Application of linear Raman spectroscopy for the determination of acetone decomposition.

Science.gov (United States)

Eichmann, Simone Christine; Trost, Johannes; Seeger, Thomas; Zigan, Lars; Leipertz, Alfred

2011-06-06

Acetone (CH3)2CO is a common tracer for laser-induced fluorescence (LIF) to investigate mixture formation processes and temperature fields in combustion applications. Since the fluorescence signal is a function of temperature and pressure, calibration measurements in high pressure and high temperature cells are necessary. However, there is a lack of reliable data of tracer stability at these harsh conditions for technical application. A new method based on the effect of spontaneous Raman scattering is proposed to analyze the thermal stability of the tracer directly in the LIF calibration cell. This is done by analyzing the gas composition regarding educts and products of the reaction. First measurements at IC engine relevant conditions up to 750 K and 30 bar are presented.

Determination of amino acid and protein peroxides by the xylenol orange-Fe(III) complex

International Nuclear Information System (INIS)

Collins, J.; Craig, G.; Gebicki, J.

1996-01-01

Oxidative stress imposed on living organisms is believed to lead to the depletion of their antioxidant defences, followed by chemical changes in the cell constituents. These may ultimately develop into pathological conditions such as cancer or cardiovascular disease. An assay of peroxides which could be applied to tissues or simple tissue extracts would prove extremely useful in the studies of the phenomenon of oxidative stress. With this purpose, the authors have tested the ability of two peroxide assay techniques to measure the formation of amino acid and protein peroxides in aqueous solutions irradiated with gamma rays, using a modification of the method based on the oxidation of Fe(II)) by peroxides and complexing of the Fe(III) produced by xylenol orange. The molar extinction coefficients of the peroxides tested were determined by comparison with the well-tested iodometric assay. This work was extended to the detection of all organic peroxides in human blood plasma or serum subjected to oxidative stress, where the iodometric assay proved difficult to apply and unreliable because of the binding of iodine to the blood components. Preliminary results suggest that exposure of serum to gamma radiation leads to immediate peroxidation of the proteins, with a delay before generation of lipid peroxides

An unprecedented process of peroxide ion formation and its localization in the crystal structure of strontium peroxy-hydroxyapatite Sr_1_0(PO_4)_6(O_2)_x(OH)_2_-_2_x

International Nuclear Information System (INIS)

Kazin, Pavel E.; Zykin, Mikhail A.; Dinnebier, Robert E.; Magdysyuk, Oxana V.; Jansen, Martin; Tretyakov, Yury D.

2012-01-01

Formation of strontium peroxy-hydroxyapatite solid solution Sr_1_0(PO_4)_6(O_2)_x(OH)_2_-_2_x was studied on annealing the hydroxyapatite in the temperature range 900-1350 C in oxygen, air, and argon atmosphere. The redox process was found to display unprecedented features: (i) the peroxide content increased with raising temperature, (ii) the peroxide content remained substantial even at a low oxygen pressure of 1.013 Pa, (iii) the peroxide content was extremely persistent, and even at a temperature of 1350 C in oxygen atmosphere the peroxide groups substituted more than two-third of the original hydroxide groups. Chemical processes consistent with these features are suggested. In the UV/Vis spectrum, an absorption peak at 300 nm was recorded, which was attributed to an electronic transition in the peroxide ion, since its intensity depended linearly on the peroxide content. In the Raman spectra, a weak band at 765-770 cm"-"1 was ascribed to symmetric stretching vibrations of O_2"2"-. The structures of the compounds were refined from powder X-ray diffraction data using the Rietveld method supported by a maximum entropy method (MEM) electron density calculation. The peroxide ions are localized in the center of the hexagonal channel. At high concentration they tend to order with the associated vacancies along the channels. As a consequence, the width of the channel sections varies, the PO_4 tetrahedra tilt, and the remote strontium atoms are displaced leading to changes in their coordination. Generally, the peroxide for hydroxide substitution manifests itself in the reduction of the overall channel diameter (and its volume), while the volume occupied by out-of-channel ions remains the same. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A vacuum ultraviolet photoionization mass spectrometric study of acetone.

Science.gov (United States)

Wei, Lixia; Yang, Bin; Yang, Rui; Huang, Chaoqun; Wang, Jing; Shan, Xiaobin; Sheng, Liusi; Zhang, Yunwu; Qi, Fei; Lam, Chow-Shing; Li, Wai-Kee

2005-05-19

The photoionization and dissociative photoionization of acetone have been studied at the photon energy range of 8-20 eV. Photoionization efficiency spectra for ions CH3COCH3+, CH3+, C2H3+, C3H3+, C3H5+, CH(2-)CO+, CH3CO+, C3H4O+, and CH3COCH2+ have been measured. In addition, the energetics of the dissociative photoionization has been examined by ab initio Gaussian-3 (G3) calculations. The computational results are useful in establishing the dissociation channels near the ionization thresholds. With the help of G3 results, the dissociation channels for the formation of the fragment ions CH3CO+, CH2CO+, CH3+, C3H3+, and CH3COCH2+ have been established. The G3 results are in fair to excellent agreement with the experimental data.

Thermodynamic analysis of acetone sensing in Pd/AlGaN/GaN heterostructure Schottky diodes at low temperatures

International Nuclear Information System (INIS)

Das, Subhashis; Majumdar, Shubhankar; Kumar, Rahul; Ghosh, Saptarsi; Biswas, Dhrubes

2016-01-01

An AlGaN/GaN heterostructure based metal–semiconductor–metal symmetrically bi-directional Schottky diode sensor structure has been employed to investigate acetone sensing and to analyze thermodynamics of acetone adsorption at low temperatures. The AlGaN/GaN heterostructure has been grown by plasma-assisted molecular beam epitaxy on Si (111). Schottky diode parameters at different temperatures and acetone concentrations have been extracted from I–V characteristics. Sensitivity and change in Schottky barrier height have been studied. Optimum operating temperature has been established. Coverage of acetone adsorption sites at the AlGaN surface and the effective equilibrium rate constant of acetone adsorption have been explored to determine the endothermic nature of acetone adsorption enthalpy.

(Liquid + liquid) equilibria for (water + 1-propanol or acetone + β-citronellol) at different temperatures

International Nuclear Information System (INIS)

Li, Hengde; Han, Yongtao; Huang, Cheng; Yang, Chufen

2015-01-01

Graphical abstract: (Liquid + liquid) equilibrium data for systems composed of β-citronellol and aqueous 1-propanol or acetone are presented. Distribution ratios of 1-propanol and acetone in the mixtures are examined. The effect of the temperature on the ternary (liquid + liquid) equilibria is evaluated and discussed. - Highlights: • Ternary (liquid + liquid) equilibria containing β-citronellol are presented. • Distribution ratios of 1-propanol and acetone in the mixtures are examined. • The effect on the temperature of the systems is evaluated and discussed. - Abstract: On this paper, experimental (liquid + liquid) equilibrium (LLE) results are presented for systems composed of β-citronellol and aqueous 1-propanol or acetone. To evaluate the phase separation properties of β-citronellol in aqueous mixtures, LLE values for the ternary systems (water + 1-propanol + β-citronellol) and (water + acetone + β-citronellol) were determined with a tie-line method at T = (283.15, 298.15, and 313.15 ± 0.02) K and atmospheric pressure. The reliability of the experimental tie-lines was verified by the Hand and Bachman equations. Ternary phase diagrams, distribution ratios of 1-propanol and acetone in the mixtures are shown. The effect of the temperature on the ternary (liquid + liquid) equilibria was examined and discussed. The experimental LLE values were satisfactorily correlated by extended UNIQUAC and modified UNIQUAC models

Photodissociation of the acetone cation at 355 nm using the velocity imaging technique

Science.gov (United States)

Jackson, William M.; Xu, Dadong

2000-09-01

Photodissociation of acetone cations, CH3COCH3+, at 355 nm has been studied by means of the ion velocity imaging technique. Acetone cations are produced via direct photoionization of a supersonic beam of acetone at 118 nm generated by frequency tripling the 355 nm laser. Only the acetyl cation, CH3CO+, could be detected as a dissociation product in the time-of-flight mass spectrometer. The acetyl ion signal depends upon the fifth power of the 355 nm laser energy, while the acetone ion signal depends upon the third power. This suggests that the fragment ion is produced via two-photon absorption of 355 nm photons by the acetone cation. The total translational energy distribution and angular distribution of acetyl cation were derived from the 2D images of CH3CO+ for the reaction CH3COCH3++2hν355nm→CH3CO++CH3*. The translational energy distribution suggests that methyl radicals are produced in two electronically excited states, the Rydberg 3s 1 2A1' and the valence 1 2A″ states. The anisotropy parameter β shows that the Rydberg state is formed via a perpendicular excitation and the valence state via a parallel transition.

Poly aniline Nano fiber as Modified Cladding for Optical Fiber Sensor to Detect Acetone Vapor

International Nuclear Information System (INIS)

Akhiruddin maddu; Ahmad aminuddin; Setyanto Tri Wahyudi; Hamdani Zain

2008-01-01

In this research, we used poly aniline nano fiber as modified cladding material for a fiber optic sensor system to detect the acetone vapor. The sensor was designed based on variation of evanescent field absorption on the core-modified cladding interface when exposed with varied acetone vapor. Poly aniline nano fiber synthesized by interfacial polymerization was coated onto the un-cladded core and acts as sensing element. Response of the fiber optic sensor was investigated by measuring the transmission light intensity via fiber optic sensor system while exposed with acetone vapor. Based on the sensor response curve, it is obtained a very fast response time of 30 s and recovery time of 10 s. The fiber optic sensor also exhibits a good reversibility and repeatability. Sensitivity of the sensor to variation of acetone vapor pressure was obtained 1.25 %/mmHg, that means the transmission intensity of the sensor changes 1.25 % for acetone vapor change of 1 mmHg. (author)

Upper Bound for Neutron Emission from Sonoluminescing Bubbles in Deuterated Acetone

International Nuclear Information System (INIS)

Camara, C. G.; Putterman, S. J.; Hopkins, S. D.; Suslick, K. S.

2007-01-01

An experimental search for nuclear fusion inside imploding bubbles of degassed deuterated acetone at 0 degree sign C driven by a 15 atm sound field and seeded with a neutron generator reveals an upper bound that is a factor of 10 000 less than the signal reported by Taleyarkhan et al. The strength of our upper bound is limited by the weakness of sonoluminescence, which we ascribe to the relatively high vapor pressure of acetone

Damages induced in lambda phage DNA by enzyme-generated triplet acetone

International Nuclear Information System (INIS)

Menck, C.F.; Cabral Neto, J.B.; Gomes, R.A.; Faljoni-Alario, A.

1985-01-01

Exposure of lambda phage to triplet acetone, generated during the aerobic oxidation of isobutanal by peroxidase, leads to genome lesions. The majority of these lesions are detected as DNA single-strand breaks only in alkaline conditions, so true breaks were not observed. Also, no sites sensitive to UV-endonuclease from Micrococcus luteus were found in DNA from treated phage. The participation of triplet acetone in the generation of such DNA damage is discussed. (Author) [pt

Catalyst-free activation of peroxides under visible LED light irradiation through photoexcitation pathway

Energy Technology Data Exchange (ETDEWEB)

Gao, Yaowen [Department of Environmental Engineering, Wuhan University, Wuhan, 430079 (China); Shenzhen Research Institute of Wuhan University, Shenzhen, 518057 (China); Li, Yixi; Yao, Linyu; Li, Simiao; Liu, Jin [Department of Environmental Engineering, Wuhan University, Wuhan, 430079 (China); Zhang, Hui, E-mail: eeng@whu.edu.cn [Department of Environmental Engineering, Wuhan University, Wuhan, 430079 (China); Shenzhen Research Institute of Wuhan University, Shenzhen, 518057 (China)

2017-05-05

Highlights: • Persulfate could decolorize Rhodamine B (RhB) directly via non-radical reactions. • LED lamps emitting white light were utilized as the visible light source. • Dyes could activate peroxides through photoexcitation pathway. • Decolorization of dyes and production of radicals were achieved simultaneously. • The catalyst-free peroxide/dye/Vis process was effective in a broad pH range. - Abstract: Catalysts are known to activate peroxides to generate active radicals (i.e., hydroxyl radical (·OH) and sulfate radical (SO{sub 4}·{sup −})) under certain conditions, but the activation of peroxides in the absence of catalysts under visible light irradiation has been rarely reported. This work demonstrates a catalyst-free activation of peroxides for the generation of ·OH and/or SO{sub 4}·{sup −} through photoexcited electron transfer from organic dyes to peroxides under visible LED light irradiation, where Rhodamine B (RhB) and Eosin Y (EY) were selected as model dyes. The formation of ·OH and/or SO{sub 4}·{sup −} in the reactions and the electron transfer from the excited dyes to peroxides were validated via electron paramagnetic resonance (EPR), photoluminescence (PL) spectra and cyclic voltammetry (CV). The performance of the peroxide/dye/Vis process was demonstrated to be altered depending on the target substrate. Meanwhile, the peroxide/dye/Vis process was effective for simultaneous decolorization of dyes and production of active radicals under neutral even or basic conditions. The findings of this study clarified a novel photoexcitation pathway for catalyst-free activation of peroxides under visible light irradiation, which could avoid the secondary metal ion (dissolved or leached) pollution from the metal-based catalysts and expand the application range of the peroxide-based catalytic process.

Pyrolysis and liquefaction of acetone and mixed acetone/ tetralin swelled Mukah Balingian Malaysian sub-bituminous coal-The effect on coal conversion and oil yield

International Nuclear Information System (INIS)

Mohd Pauzi Abdullah; Mohd Azlan Mohd Ishak; Khudzir Ismail

2008-01-01

The effect of swelling on Mukah Balingian (MB) Malaysian sub-bituminous coal macrostructure was observed by pyrolysing the swelled coal via thermogravimetry under nitrogen at ambient pressure. The DTG curves of the pyrolyzed swelled coal samples show the presence of evolution peaks at temperature ranging from 235 - 295 degree Celsius that are due to releasing of light molecular weight hydrocarbons. These peaks, however, were not present in the untreated coal, indicating some changes in the coal macrostructure has occurred in the swelled coal samples. The global pyrolysis kinetics for coal that follows the first-order decomposition reaction was used to evaluate the activation energy of the pyrolyzed untreated and swelled coal samples. The results thus far have shown that the activation energy for the acetone and mixed acetone/ tetralin-swelled coal samples exhibit lower values than untreated coal, indicating less energy is required during the pyrolysis process due to the weakening of the coal-coal macromolecular interaction network. Moreover, liquefaction on the swelled coal samples that was carried out at temperatures ranging from 360 to 450 degree Celsius at 4 MPa of nitrogen pressure showed the enhancement of the coal conversion and oil yield at temperature of 420 degree Celsius, with retrogressive reaction started to dominate at higher temperature as indicated by decreased and increased in oil yield and high molecular weight pre-asphaltene, respectively. These observations suggest that the solvent swelling pre-treatment using acetone and mixed acetone/ tetralin can improve the coal conversion and oil yields at less severe liquefaction condition. (author)

Formation of three-dimensional nano-porous silver films and application toward electrochemical detection of hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Fan, Junpeng [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Bian, Xiufang, E-mail: xfbian@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Niu, Yuchao [Department of Materials Science and Engineering, Shandong Jianzhu University, Fengming Road, Lingang Development Zone, Jinan 250101 (China); Bai, Yanwen; Xiao, Xinxin; Yang, Chuncheng; Yang, Jianfei; Yang, Jinyue [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)

2013-11-15

By using the chemically dealloying method, three-dimensional nano-porous silver films (3-D NPSFs) are fabricated into a novel sensor for detecting hydrogen peroxide. The precursor films are prepared by high vacuum magnetron co-sputtering. High-resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) are taken to investigate the structure and the micro morphology of the precursor films and nano-porous films. We find that the precursor films are composed of glassy matrix and nanocrystallines. After dealloying, the films exhibit a combination of homogenously distributed pores and silver filaments, and exhibit an open, three dimensional bicontinuous interpenetrating ligament–channel structure. Thickness and morphology of the films can be easily controlled by the sputtering time and alloy composition of the precursor films, respectively. In addition, NPSFs show a good linear responding for the concentration of hydrogen peroxide in phosphate buffered solutions, which indicates NPSFs could be a promising electrochemical material for hydrogen peroxide detection.

The thermodynamic characteristics of the reaction between vanadium(5) and hydrogen peroxide in concentrated solutions of perchloric acid

International Nuclear Information System (INIS)

Vorob'ev, P.N.; Dmitrieva, N.G.; Poteshonkova, T.A.

2001-01-01

Stability constants of vanadium(5) complex with hydrogen peroxide and enthalpy of vanadium(5) complexing with hydrogen peroxide are determined at acidity of solution c(H + ) = 5.00 mol/l, temperature T = 298.15 K and values of ionic force: I = 5, 6 and 7. Standard thermodynamic characteristics of vanadium(5) peroxide complex formation were calculated. At zeroth ionic force the value of complexing enthalpy Δ r H 298.15 deg is equal to -48.59 ± 0.33 kJ/mol, standard enthalpy of peroxide vanadium(5) complex formation Δ f H 298.15 deg is equal to -895.49 ± 1.51 kJ/mol; Δ r G 298.15 deg = -36.51 kJ/mol, Δ r S 298.15 deg -40.51 J/(mol K). As it is shown by calculations, standard change in entropy of the reaction has a minus sign, that is unique to complexation with neutral ligand [ru

Ultratrace Measurement of Acetone from Skin Using Zeolite: Toward Development of a Wearable Monitor of Fat Metabolism.

Science.gov (United States)

Yamada, Yuki; Hiyama, Satoshi; Toyooka, Tsuguyoshi; Takeuchi, Shoji; Itabashi, Keiji; Okubo, Tatsuya; Tabata, Hitoshi

2015-08-04

Analysis of gases emitted from human skin and contained in human breath has received increasing attention in recent years for noninvasive clinical diagnoses and health checkups. Acetone emitted from human skin (skin acetone) should be a good indicator of fat metabolism, which is associated with diet and exercise. However, skin acetone is an analytically challenging target because it is emitted in very low concentrations. In the present study, zeolite was investigated for concentrating skin acetone for subsequent semiconductor-based analysis. The adsorption and desorption characteristics of five zeolites with different structures and those hydrophobicities were compared. A hydrophobic zeolite with relatively large pores (approximately 1.6 times larger than the acetone molecule diameter) was the best concentrator of skin acetone among the zeolites tested. The concentrator developed using zeolite was applied in a semiconductor-based gas sensor in a simulated mobile environment where the closed space was frequently collapsed to reflect the twisting and elastic movement of skin that would be encountered in a wearable device. These results could be used to develop a wearable analyzer for skin acetone, which would be a powerful tool for preventing and alleviating lifestyle-related diseases.

The Acetone Extract of Sclerocarya birrea (Anacardiaceae) Possesses Antiproliferative and Apoptotic Potential against Human Breast Cancer Cell Lines (MCF-7)

Science.gov (United States)

Tanih, Nicoline Fri; Ndip, Roland Ndip

2013-01-01

Interesting antimicrobial data from the stem bark of Sclerocarya birrea, which support its use in traditional medicine for the treatment of many diseases, have been delineated. The current study was aimed to further study some pharmacological and toxicological properties of the plant to scientifically justify its use. Anticancer activity of water and acetone extracts of S. birrea was evaluated on three different cell lines, HT-29, HeLa, and MCF-7 using the cell titre blue viability assay in 96-well plates. Apoptosis was evaluated using the acridine orange and propidium iodide staining method, while morphological structure of treated cells was examined using SEM. The acetone extract exhibited remarkable antiproliferative activities on MCF-7 cell lines at dose- and time-dependent manners (24 h and 48 h of incubation). The extract also exerted apoptotic programmed cell death in MCF-7 cells with significant effect on the DNA. Morphological examination also displayed apoptotic characteristics in the treated cells, including clumping, condensation, and culminating to budding of the cells to produce membrane-bound fragmentation, as well as formation of apoptotic bodies. The acetone extract of S. birrea possesses antiproliferative and apoptotic potential against MCF-7-treated cells and could be further exploited as a potential lead in anticancer therapy. PMID:23576913

Biofiltration of mixtures of gas-phase styrene and acetone with the fungus Sporothrix variecibatus

International Nuclear Information System (INIS)

Rene, Eldon R.; Spackova, Radka; Veiga, Maria C.; Kennes, Christian

2010-01-01

The biodegradation performance of a biofilter, inoculated with the fungus Sporothrix variecibatus, to treat gas-phase styrene and acetone mixtures under steady-state and transient conditions was evaluated. Experiments were carried out by varying the gas-flow rates (0.05-0.4 m 3 h -1 ), leading to empty bed residence times as low as 17.1 s, and by changing the concentrations of gas-phase styrene (0.01-6.3 g m -3 ) and acetone (0.01-8.9 g m -3 ). The total elimination capacities were as high as 360 g m -3 h -1 , with nearly 97.5% removal of styrene and 75.6% for acetone. The biodegradation of acetone was inhibited by the presence of styrene, while styrene removal was affected only slightly by the presence of acetone. During transient-state experiments, increasing the overall pollutant load by almost 3-fold, i.e., from 220 to 600 g m -3 h -1 , resulted in a sudden drop of removal efficiency (>90-70%), but still high elimination capacities were maintained. Periodic microscopic observations revealed that the originally inoculated Sporothrix sp. remained present in the reactor and actively dominant in the biofilm.

Study of the exhaled acetone in type 1 diabetes using quantum cascade laser spectroscopy.

Science.gov (United States)

Reyes-Reyes, Adonis; Horsten, Roland C; Urbach, H Paul; Bhattacharya, Nandini

2015-01-06

The acetone concentration exhaled in the breath of three type 1 diabetes patients (two minors and one adult) and one healthy volunteer is studied using a quantum cascade laser-based spectroscopic system. Using the acetone signature between 1150 and 1250 cm(-1) and a multiline fitting method, the concentration variations on the order of parts per billion by volume were measured. Blood glucose and ketone concentrations in blood measurements were performed simultaneously to study their relation with acetone in exhaled breath. We focus on personalized studies to better understand the role of acetone in diabetes. For each volunteer, we performed a series of measurements over a period of time, including overnight fastings of 11 ± 1 h and during ketosis-hyperglycemia events for the minors. Our results highlight the importance of performing personalized studies because the response of the minors to the presence of ketosis was consistent but unique for each individual. Also, our results emphasize the need for performing more studies with T1D minors, because the acetone concentration in the breath of the minors differs, with respect to those reported in the literature, which are based on adults.

Solvents (butanol, acetone, and ethanol). [USSR Patent

Energy Technology Data Exchange (ETDEWEB)

Yarovenko, V L; Nakhmanovich, B M

1963-07-17

The method involves use of carbohydrate-containing plant raw-material, e.g. hydrolyzates of corn cob and pulp. The material is subjected to fermentation with acetone-butanol bacteria with addition of starch-industry wastes as source of proteins (gluten and gluten-containing water) and nutrient salts.

Profiling and relative quantification of phosphatidylethanolamine based on acetone stable isotope derivatization

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiang [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Wei, Fang, E-mail: willasa@163.com [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Xu, Ji-qu; Lv, Xin; Dong, Xu-yan [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Han, Xianlin [Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL 32827 (United States); College of Basic Medical Sciences, Zhejiang Chinese Medical University, 548 Bingwen Road, Hangzhou, Zhejiang 310053 (China); Quek, Siew-young [School of Chemical Science, The University of Auckland, Auckland 1142 (New Zealand); Huang, Feng-hong [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China); Chen, Hong, E-mail: chenhong@oilcrops.cn [Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture (China); Hubei Key Laboratory of Lipid Chemistry and Nutrition (China)

2016-01-01

Phosphatidylethanolamine (PE) is considered to be one of the pivotal lipids for normal cellular function as well as disease initiation and progression. In this study, a simple, efficient, reliable, and inexpensive method for the qualitative analysis and relative quantification of PE, based on acetone stable isotope derivatization combined with double neutral loss scan-shotgun electrospray ionization tandem-quadrupole mass spectrometry analysis (ASID-DNLS-Shotgun ESI-MS/MS), was developed. The ASID method led to alkylation of the primary amino groups of PE with an isopropyl moiety. The use of acetone (d{sub 0}-acetone) and deuterium-labeled acetone (d{sub 6}-acetone) introduced a 6 Da mass shift that was ideally suited for relative quantitative analysis, and enhanced sensitivity for mass analysis. The DNLS model was introduced to simultaneously analyze the differential derivatized PEs by shotgun ESI-MS/MS with high selectivity and accuracy. The reaction specificity, labeling efficiency, and linearity of the ASID method were thoroughly evaluated in this study. Its excellent applicability was validated by qualitative and relative quantitative analysis of PE species presented in liver samples from rats fed different diets. Using the ASID-DNLS-Shotgun ESI-MS/MS method, 45 PE species from rat livers have been identified and quantified in an efficient manner. The level of total PEs tended to decrease in the livers of rats on high fat diets compared with controls. The levels of PE 32:1, 34:3, 34:2, 36:3, 36:2, 42:10, plasmalogen PE 36:1 and lyso PE 22:6 were significantly reduced, while levels of PE 36:1 and lyso PE 16:0 increased. - Highlights: • A novel isotope reagent acetone was explored for the derivatization of PEs. • The labeling reaction was carried out under mild conditions with high specificity. • Enhanced detection sensitivity of PEs was achieved after derivatization. • The ASID-DNLS-Shotgun MS/MS method was used to relative quantification of PEs.

Free energy of mixing of acetone and methanol: a computer simulation investigation.

Science.gov (United States)

Idrissi, Abdenacer; Polok, Kamil; Barj, Mohammed; Marekha, Bogdan; Kiselev, Mikhail; Jedlovszky, Pál

2013-12-19

The change of the Helmholtz free energy, internal energy, and entropy accompanying the mixing of acetone and methanol is calculated in the entire composition range by the method of thermodynamic integration using three different potential model combinations of the two compounds. In the first system, both molecules are described by the OPLS, and in the second system, both molecules are described by the original TraPPE force field, whereas in the third system a modified version of the TraPPE potential is used for acetone in combination with the original TraPPE model of methanol. The results reveal that, in contrast with the acetone-water system, all of these three model combinations are able to reproduce the full miscibility of acetone and methanol, although the thermodynamic driving force of this mixing is very small. It is also seen, in accordance with the finding of former structural analyses, that the mixing of the two components is driven by the entropy term corresponding to the ideal mixing, which is large enough to overcompensate the effect of the energy increase and entropy loss due to the interaction of the unlike components in the mixtures. Among the three model combinations, the use of the original TraPPE model of methanol and modified TraPPE model of acetone turns out to be clearly the best in this respect, as it is able to reproduce the experimental free energy, internal energy, and entropy of mixing values within 0.15 kJ/mol, 0.2 kJ/mol, and 1 J/(mol K), respectively, in the entire composition range. The success of this model combination originates from the fact that the use of the modified TraPPE model of acetone instead of the original one in these mixtures improves the reproduction of the entropy of mixing, while it retains the ability of the original model of excellently reproducing the internal energy of mixing.

Brief Communication: Comparison of formol-acetone concentration ...

African Journals Online (AJOL)

Background: Formol-ether concentration technique is taken as a gold standard method to detect most intestinal parasites; however, because of its low safety and hazardous impact a need for better technique has a paramount importance. Objective: To evaluate a formol- acetone concentration method in comparison with the ...

Dielectric barrier discharge micro-plasma emission spectrometry for the detection of acetone in exhaled breath.

Science.gov (United States)

Yang, Ting; Gao, Dong-Xue; Yu, Yong-Liang; Chen, Ming-Li; Wang, Jian-Hua

2016-01-01

Acetone is a predominant volatile organic compound (VOC) in the exhaled breath and a promising biomarker for diabetes and ketoacidosis. A non-thermal micro-plasma generated in a planar dielectric barrier discharge (DBD) is used as a radiation source for the excitation of gaseous acetone followed by its quantification with optical emission spectrometry (OES). Gaseous acetone can be directly sampled, while liquid acetone is evaporated by heated tungsten coil and then introduced into the DBD micro-plasma by a helium carrier flow for performing optical emission and detection at a 519 nm emission line. In the present study, the exhaled breath is collected and transferred into aqueous medium for sampling. With a sampling volume of 7 μL in a micro-drop, a linear range of 40-1600 mg L(-1) is obtained along with a detection limit of 44 ng and a precision of 5.7% RSD. The present system is successfully applied to the determination of breath acetone for both diabetic patients and healthy volunteers. Copyright © 2015 Elsevier B.V. All rights reserved.

Oxidation of cumene hydroperoxide on glassy carbon electrodes in aqueous solution and its interaction with ascorbic and gallic acids

International Nuclear Information System (INIS)

Estévez, Rafael; Mellado, José Miguel Rodríguez; Mayén, Manuel

2015-01-01

The cumene hydroperoxide oxidation on glassy carbon electrodes involves an irreversible one-electron transfer to peroxide and phenoxy radicals, being the main end products hydroquinone and acetone. The overall oxidation mechanism occurs in two steps: formation of acetone and a phenoxy radical, and the reaction of this phenoxy radical with water, getting stability by oxidizing into p-benzoquinone The interaction of such radicals with ascorbic and gallic acids decreases the oxidation signal of cumene hydroperoxide in differential pulse voltammetry. This decrease, due to the scavenging of the radicals formed after the electron transfer, is related to the antioxidant activities. So, it is possible to substitute the mercury as a probe for the electrochemical determination of antioxidant activity.

Involvement of an ATP-dependent carboxylase in a CO2-dependent pathway of acetone metabolism by Xanthobacter strain Py2.

OpenAIRE

Sluis, M K; Small, F J; Allen, J R; Ensign, S A

1996-01-01

The metabolism of acetone by the aerobic bacterium Xanthobacter strain Py2 was investigated. Cell suspensions of Xanthobacter strain Py2 grown with propylene or glucose as carbon sources were unable to metabolize acetone. The addition of acetone to cultures grown with propylene or glucose resulted in a time-dependent increase in acetone-degrading activity. The degradation of acetone by these cultures was prevented by the addition of rifampin and chloramphenicol, demonstrating that new protein...

Poly-MVA attenuates 7,12- dimethylbenz[a]anthracene initiated and croton oil promoted skin papilloma formation on mice skin.

Science.gov (United States)

Veena, Ravindran K; Ajith, Thekkuttuparambil A; Janardhanan, Kainoor K; Antonawich, Francis

2017-09-01

Chemopreventive agents which exhibit activities such as anti-inflammation, inhibition of carcinogen induced mutagenesis and scavenging of free radical might play a decisive role in the inhibition of chemical carcinogenesis either at the initiation or promotion stage. Many synthesized palladium (Pd) complexes tested experimentally for antitumor activity are found effective. Poly-MVA is a liquid blend preparation containing B complex vitamins, ruthenium with Pd complexed with alpha lipoic acid as the major ingredients. The antitumor effect of Poly-MVA was evaluated against 7,12-dimethylbenz[a] anthracene-initiated croton oil-promoted papilloma formation on mice skin. Skin tumor was initiated with a single application of 390 nmol of DMBA in 20 µl acetone. The effect of Poly-MVA against croton oil- induced inflammation and lipid peroxidation on the mice skin was also evaluated. Topical application of Poly-MVA (100 µl, twice weekly for 18 weeks) 30 minutes prior to each croton oil application, significantly decreased the tumor incidence (11%) and the average number of tumor per animals. Application of Poly-MVA (100 µl) before croton oil significantly (p < 0.05) protected the mouse skin from inflammation (36%) and lipid peroxidation (14%) when compared to the croton oil alone treated group. Experimental results indicate that Poly-MVA attenuate the tumor promoting effects of croton oil and the effect may probably be due to its anti-inflammatory and antioxidant activity.

Acetone production using silicon nanoparticles and catalyst compositions

KAUST Repository

Chaieb, Saharoui; Demellawi, Jehad El; Al-Talla, Zeyad

2015-01-01

Embodiments of the present disclosure provide for a catalytic reaction to produce acetone, a catalyst that include a mixture of silicon particles (e.g., about 1 to 20 nm in diameter) and a solvent, and the like.

Acetone production using silicon nanoparticles and catalyst compositions

KAUST Repository

Chaieb, Sahraoui

2015-12-10

Embodiments of the present disclosure provide for a catalytic reaction to produce acetone, a catalyst that include a mixture of silicon particles (e.g., about 1 to 20 nm in diameter) and a solvent, and the like.

Catalase induction in normal and tumorigenic mice using x-rays, clofibrate, ethanol, or hydrogen peroxide

International Nuclear Information System (INIS)

Alexander, L.; Oberley, L.

1985-01-01

The authors studied catalase induction in normal male Swiss mice as well as in male mice harboring H-6 hepatomas. The induction patterns many suggest reasons why tumor cells have lower catalase activity than normal cells. X-rays, hydrogen peroxide, ethanol, and clofibrate were used as inducing agents. X-rays interact with tissue and cause free radical formation. This results in an increase in hydrogen peroxide concentration, which ought to induce catalase. Oral administration of hydrogen peroxide should induce catalase similarly. Ethanol can be a substrate for catalase, forming acetalehyde; and as such may induce catalase. Ethanol can also restore inactive catalase compound II to useful catalase. Clofibrate is a hypolipidemic agent which induces catalase, most likely because of its ability to accelerate lipid breakdown, which raises peroxide concentration

Relationship of O2 Photodesorption in Photooxidation of Acetone on TiO2

International Nuclear Information System (INIS)

Henderson, Michael A.

2008-01-01

Organic photooxidation on TiO2 invariably involves the coexistence of organic species with oxygen on the surface at the same time. In the case of acetone and oxygen, both species exhibit their own interesting photochemistry on TiO2, but interdependences between the two are not understood. In this study, a rutile TiO2(110) surface possessing 7% surface oxygen vacancy sites is used as a model surface to probe the relationship between O2 photodesorption and acetone photodecomposition. Temperature programmed desorption (TPD) and photon stimulated desorption (PSD) measurements indicate that coadsorbed oxygen is essential to acetone photodecomposition on this surface, however the form of oxygen (molecular and dissociative) is not known. The first steps in acetone photodecomposition on TiO2(110) involve thermal activation with oxygen to form an acetone diolate ((CH3)2COO) species followed by photochemical decomposition to adsorbed acetate (CH3COO) and an ejected CH3 radical that is detected in PSD. Depending on the surface conditions, O2 PSD is also observed during the latter process. However, the time scales for the two PSD events (CH3 and O2) are quite different, with the former occurring at ∼10 times faster than the latter. By varying the preheating conditions or performing pre-irradiation on an O2 exposed surface, it becomes clear that the two PSD events are uncorrelated. That is, the O2 species responsible for O2 PSD is not a significant participant in the photochemistry of acetone on TiO2(110) and likely originates from a minority form of O2 on the surface. The CH3 and O2 PSD events do not appear to be in competition with each other suggesting either that ample charge carriers exist under the experimental conditions employed or that different charge carriers or excitation mechanisms are involved

Processing of beet-sugar molasses in the acetone-butyl alcohol industry

Energy Technology Data Exchange (ETDEWEB)

Zalesskaya, M I; Logotkin, I S; Marfina, A M; Gus' kova, N P; Chekasina, E V

1958-01-01

Possibility of partial replacement of flour by beet-sugar molasses (I) in acetone-BuOH fermentation was investigated on a commercial scale. Detailed regimes of experiments carried out in two trials were given. Yields of fermentation (kg/1000 kg starch of mash) were: 125.3, 214.4, and 31.5 of acetone, BuOH and EtOH, respectively, for pure flour-mash; 123.3, 215.3, and 28.7 of acetone, BuOH, and EtOH, respectively, at 10% flour replaced by I; 127.8, 205.9, and 51.8, respectively, at 50% flour replaced by I; and 120.17, 216.48, and 42.3, respectively, at 62% flour replaced by I. Inoculum, grown in the seed-mash containing flour only, was not mixed with fermentor-mash until the stage of acid production by the inoculum was reached. During the fermentation of mashes in which 62% flour was replaced by I, a slight foaming was observed.

Acetone-Linked Peptides: A Convergent Approach for Peptide Macrocyclization and Labeling.

Science.gov (United States)

Assem, Naila; Ferreira, David J; Wolan, Dennis W; Dawson, Philip E

2015-07-20

Macrocyclization is a broadly applied approach for overcoming the intrinsically disordered nature of linear peptides. Herein, it is shown that dichloroacetone (DCA) enhances helical secondary structures when introduced between peptide nucleophiles, such as thiols, to yield an acetone-linked bridge (ACE). Aside from stabilizing helical structures, the ketone moiety embedded in the linker can be modified with diverse molecular tags by oxime ligation. Insights into the structure of the tether were obtained through co-crystallization of a constrained S-peptide in complex with RNAse S. The scope of the acetone-linked peptides was further explored through the generation of N-terminus to side chain macrocycles and a new approach for generating fused macrocycles (bicycles). Together, these studies suggest that acetone linking is generally applicable to peptide macrocycles with a specific utility in the synthesis of stabilized helices that incorporate functional tags. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Marangoni convection induced by acetone desorption from the falling soap film

Science.gov (United States)

Sha, Yong; Li, Zhangyun; Wang, Yongyi; Huang, Jiali

2012-05-01

By means of the falling soap film tunnel and the Schlieren optical method, the Marangoni convection were observed directly in the immediate interfacial neighborhood during the desorption process of acetone from the falling soap film. Moreover, the hydraulic characteristics of the falling soap film tunnel, the acetone concentration, the surface tension of the soap liquid and the mass transfer has been investigated in details through the experimental or theoretical method.

Biofiltration of mixtures of gas-phase styrene and acetone with the fungus Sporothrix variecibatus

Energy Technology Data Exchange (ETDEWEB)

Rene, Eldon R.; Spackova, Radka; Veiga, Maria C. [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain); Kennes, Christian, E-mail: kennes@udc.es [University of La Coruna, Dpt. of Chemical Engineering, Campus da Zapateira, Rua da Fraga, 10, 15008 La Coruna (Spain)

2010-12-15

The biodegradation performance of a biofilter, inoculated with the fungus Sporothrix variecibatus, to treat gas-phase styrene and acetone mixtures under steady-state and transient conditions was evaluated. Experiments were carried out by varying the gas-flow rates (0.05-0.4 m{sup 3} h{sup -1}), leading to empty bed residence times as low as 17.1 s, and by changing the concentrations of gas-phase styrene (0.01-6.3 g m{sup -3}) and acetone (0.01-8.9 g m{sup -3}). The total elimination capacities were as high as 360 g m{sup -3} h{sup -1}, with nearly 97.5% removal of styrene and 75.6% for acetone. The biodegradation of acetone was inhibited by the presence of styrene, while styrene removal was affected only slightly by the presence of acetone. During transient-state experiments, increasing the overall pollutant load by almost 3-fold, i.e., from 220 to 600 g m{sup -3} h{sup -1}, resulted in a sudden drop of removal efficiency (>90-70%), but still high elimination capacities were maintained. Periodic microscopic observations revealed that the originally inoculated Sporothrix sp. remained present in the reactor and actively dominant in the biofilm.

Silver-palladium catalysts for the direct synthesis of hydrogen peroxide

Science.gov (United States)

Khan, Zainab; Dummer, Nicholas F.; Edwards, Jennifer K.

2017-11-01

A series of bimetallic silver-palladium catalysts supported on titania were prepared by wet impregnation and assessed for the direct synthesis of hydrogen peroxide, and its subsequent side reactions. The addition of silver to a palladium catalyst was found to significantly decrease hydrogen peroxide productivity and hydrogenation, but crucially increase the rate of decomposition. The decomposition product, which is predominantly hydroxyl radicals, can be used to decrease bacterial colonies. The interaction between silver and palladium was characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The results of the TPR and XPS indicated the formation of a silver-palladium alloy. The optimal 1% Ag-4% Pd/TiO2 bimetallic catalyst was able to produce approximately 200 ppm of H2O2 in 30 min. The findings demonstrate that AgPd/TiO2 catalysts are active for the synthesis of hydrogen peroxide and its subsequent decomposition to reactive oxygen species. The catalysts are promising for use in wastewater treatment as they combine the disinfectant properties of silver, hydrogen peroxide production and subsequent decomposition. This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

Role of lipid peroxidation and oxidative stress in 3-methylindole pneumotoxicity

International Nuclear Information System (INIS)

Cary, M.G.

1985-01-01

The cytochrome P-450-catalyzed metabolism of 3-methylindole (3-MI) results in acute lung injury in ruminants and horses. Experiments were conducted to determine the role of lipid peroxidation and oxidative stress in 3-MI pneumotoxicity in goats. Goats were given methylethylketone peroxide (MEKP), a potent peroxidant, 3-MI, indole, or cremophor-EL vehicle. The levels of shortchain hydrocarbons in expired air were measured for 6 hours post-dosing by gas chromatography. Exhaled hydrocarbons increased 20 to 30 fold within 1 hour in goats given MEKP. No significant changes were seen in goats given 3-Mi, indole or cremophor-EL. Levels of thiobarbituric acid-reactive substances, an indicator of lipid peroxidation, were significantly increased in lung tissue from goats given MEKP. In goats given 3-MI, indole or cremophor-EL, the levels were not significantly different from each other. Goats were killed at 6 hours post-dosing and examined post mortem. Bronchiolar epithelial necrosis was seen in goats given 3-MI but there were not lung lesions in other groups. The role of oxygen radicals in 3-MI pneumotoxicity was examined in a goat lung explant system using 51 Cr release as an indicator of cytotoxicity. The results of these studies provide no evidence to support the view that 3-MI pneumotoxicity involves lipid peroxidation or oxidative stress as a result of formation of oxygen or xenobiotic radicals

Decryptification of Acid Phosphatase in Arthrospores of Geotrichum Species Treated with Dimethyl Sulfoxide and Acetone

Science.gov (United States)

Cotter, David A.; Martel, Anita J.; MacDonald, Paul

1975-01-01

Decryptification of acid phosphatase in Geotrichum sp. arthrospores was accomplished using acetone or dimethyl sulfoxide treatment. Both dimethyl sulfoxide and acetone irreversibly destroyed the integrity of the spore membranes without solubilizing acid phosphatase. PMID:1167386

Profiling and relative quantification of phosphatidylethanolamine based on acetone stable isotope derivatization.

Science.gov (United States)

Wang, Xiang; Wei, Fang; Xu, Ji-Qu; Lv, Xin; Dong, Xu-Yan; Han, Xianlin; Quek, Siew-Young; Huang, Feng-Hong; Chen, Hong

2016-01-01

Phosphatidylethanolamine (PE) is considered to be one of the pivotal lipids for normal cellular function as well as disease initiation and progression. In this study, a simple, efficient, reliable, and inexpensive method for the qualitative analysis and relative quantification of PE, based on acetone stable isotope derivatization combined with double neutral loss scan-shotgun electrospray ionization tandem-quadrupole mass spectrometry analysis (ASID-DNLS-Shotgun ESI-MS/MS), was developed. The ASID method led to alkylation of the primary amino groups of PE with an isopropyl moiety. The use of acetone (d0-acetone) and deuterium-labeled acetone (d6-acetone) introduced a 6 Da mass shift that was ideally suited for relative quantitative analysis, and enhanced sensitivity for mass analysis. The DNLS model was introduced to simultaneously analyze the differential derivatized PEs by shotgun ESI-MS/MS with high selectivity and accuracy. The reaction specificity, labeling efficiency, and linearity of the ASID method were thoroughly evaluated in this study. Its excellent applicability was validated by qualitative and relative quantitative analysis of PE species presented in liver samples from rats fed different diets. Using the ASID-DNLS-Shotgun ESI-MS/MS method, 45 PE species from rat livers have been identified and quantified in an efficient manner. The level of total PEs tended to decrease in the livers of rats on high fat diets compared with controls. The levels of PE 32:1, 34:3, 34:2, 36:3, 36:2, 42:10, plasmalogen PE 36:1 and lyso PE 22:6 were significantly reduced, while levels of PE 36:1 and lyso PE 16:0 increased. Copyright © 2015 Elsevier B.V. All rights reserved.

Improvement of the cold flow characteristics of biodiesel containing dissolved polymer wastes using acetone

Directory of Open Access Journals (Sweden)

Pouya Mohammadi

2014-03-01

Full Text Available Due to the fast fossil fuel depletion and at the same time global warming phenomenon anticipated for the next coming years, the necessity of developing alternative fuels e.g. biofuels (i.e. bioethanol, biodiesel, biogas and etc. has turned into an important concern. Recently, the application of the bio-solvency properties of biodiesel for recycling waste polymers has been highlighted. However, the impact of polymer dissolution on cold flow characteristics of biodiesel was never investigated. The present study was set to explore the impact of different solvents in stabilizing biodiesel-polymer solution. Among them, acetone was proved to be the best fuel stabilizer. Subsequently, cold flow characteristic i.e. cloud point, of the biodiesel-polymer-acetone fuel was found to have improved (decreased due to the inclusion of acetone. Finally, flash point analysis of the fuel blends containing acetone was done to ensured high safety of the fuel blend by dramatically increasing the flash point values of biodiesel-polymer fuel blends.

Lidar/DIAL detection of acetone at 3.3 μm by a tunable OPO laser system

Science.gov (United States)

Puiu, A.; Fiorani, L.; Rosa, O.; Borelli, R.; Pistilli, M.; Palucci, A.

2014-08-01

In this paper we report, for the first time to our knowledge, on lidar/DIAL detection of acetone vapors at 3.3 μm by means of an optical parametric tunable laser system. After a preliminary spectroscopic study in an absorption cell, the feasibility of a differential absorption (DIAL) lidar for the detection of acetone vapors has been investigated in the laboratory, simulating the experimental conditions of a field campaign. Having in mind measurements in a real scenario, a study of possible atmospheric intereferents has been performed, looking for all known compounds that share acetone IR absorption in the spectral band selected for its detection. Possible interfering species from urban and industrial atmospheres were investigated and limits of acetone detection in both environments were identified. This study confirmed that a lidar system can detect a low concentration of acetone at considerable distances.

Hydrogen Peroxide and Ozone Formation in Hybrid Gas-Liquid Electrical Discharge Reactors

Czech Academy of Sciences Publication Activity Database

Lukeš, Petr; Appleton, A. T.; Locke, B. R.

2004-01-01

Roč. 40, č. 1 (2004), s. 60-67 ISSN 0093-9994. [IEEE Industry Applications Society Annual Meeting 2002/37th./. Pittsburgh, Pennsylvania , 13.10.2002-18.10.2002] R&D Projects: GA ČR GA202/02/1026; GA MŠk ME 472 Grant - others:NSF(US) INT0086351 Keywords : hydrogen peroxide, ozone, corona discharge, water treatment, hybrid reactor Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.987, year: 2004

Application of Raman Spectroscopy for the Detection of Acetone Dissolved in Transformer Oil

Science.gov (United States)

Gu, Z.; Chen, W.; Du, L.; Shi, H.; Wan, F.

2018-05-01

The CLRS detection characteristics of acetone dissolved in transformer oil were analyzed. Raman spectral peak at 780 cm-1 was used as the characteristic spectral peak for qualitative and quantitative analyses. The effect of the detection depth and the temperature was investigated in order to obtain good Raman signals. The optimal detection depth and temperature were set as 3 mm and room temperature. A quantitative model relation between concentration and the Raman peak intensity ratio I 780/I 893 was constructed via the least-squares method. The results demonstrated that CLRS can quantitatively detect the concentration of acetone in transformer oil and CLRS has potential as a useful alternative for accelerating the in-situ analysis of the concentration of acetone in transformer oil.

Application of Raman Spectroscopy for the Detection of Acetone Dissolved in Transformer Oil

Science.gov (United States)

Gu, Z.; Chen, W.; Du, L.; Shi, H.; Wan, F.

2018-05-01

The CLRS detection characteristics of acetone dissolved in transformer oil were analyzed. Raman spectral peak at 780 cm-1 was used as the characteristic spectral peak for qualitative and quantitative analyses. The effect of the detection depth and the temperature was investigated in order to obtain good Raman signals. The optimal detection depth and temperature were set as 3 mm and room temperature. A quantitative model relation between concentration and the Raman peak intensity ratio I 780/ I 893 was constructed via the least-squares method. The results demonstrated that CLRS can quantitatively detect the concentration of acetone in transformer oil and CLRS has potential as a useful alternative for accelerating the in-situ analysis of the concentration of acetone in transformer oil.

Hydrogen peroxide as a sustainable energy carrier: Electrocatalytic production of hydrogen peroxide and the fuel cell

International Nuclear Information System (INIS)

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 O 2 -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 O 2 , 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.

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

Science.gov (United States)

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

2012-11-01

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 O 2 -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 O 2 , 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.

Acetone and acetaldehyde determination in tomato juice by isotopic dilution

International Nuclear Information System (INIS)

Piva, M.-T.; Crouzet, J.

1977-01-01

Acetone and acetaldehyde content of tomato juice were determined by isotope dilution techniques. The juice is added to 14 C labelled compounds, carried along by nitrogen at low pressure. The mixture of 2.4 dinitrophenylhydrazones obtained from volatile compounds is separated by thin layer chromatography on silica gel and then on alumina. A determination of radioactivity and concentration of acetone and acetaldehyde 2,4 dinitrophenylhydrazones obtained after separation and elution allow to calculate the content of these two compounds in the initial product with the same sample. This technique could be used for determination of methanol and ethanol after transformation in 3,5 dinitrobenzoates [fr

Inactivation of Cronobacter malonaticus cells and inhibition of its biofilm formation exposed to hydrogen peroxide stress.

Science.gov (United States)

Ye, Yingwang; Zhang, Maofeng; Jiao, Rui; Ling, Na; Zhang, Xiyan; Tong, Liaowang; Zeng, Haiyang; Zhang, Jumei; Wu, Qingping

2018-01-01

Presence of Cronobacter malonaticus in powdered infant formula (PIF) poses a high risk to infant and public health. Cronobacter malonaticus has been widely distributed in food and food processing environments, and the true origin of C. malonaticus in PIF is poorly understood. Control and prevention of C. malonaticus is necessary for achieving microbial safety of PIF. However, little information about decontamination of C. malonaticus is available. In this study, effects of hydrogen peroxide on inactivation and morphological changes of C. malonaticus cells were determined. Furthermore, inhibitory effects of H 2 O 2 on biofilm formation in C. malonaticus were also performed. Results indicated that H 2 O 2 could completely inactivate C. malonaticus in sterile water with 0.06% H 2 O 2 for 25 min, 0.08% H 2 O 2 for 15 min, and 0.10% for 10 min, respectively, whereas the survival rates of C. malonaticus in tryptic soy broth medium significantly increased with the same treatment time and concentration of H 2 O 2 . In addition, morphological changes of C. malonaticus cells, including cell shrinkage, disruption of cells, cell intercession, and leakage of intercellular material in sterile water after H 2 O 2 treatment, were more predominant than those in tryptic soy broth. Finally, significant reduction in biofilm formation by H 2 O 2 was found using crystal violet staining, scanning electron microscopy, and confocal laser scanning microscopy detection compared with control samples. This is the first report to determine the effects of H 2 O 2 on C. malonaticus cells and biofilm formation. The findings provided valuable information for practical application of H 2 O 2 for decontamination of C. malonaticus in dairy processing. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Optical acetone vapor sensors based on chiral nematic liquid crystals and reactive chiral dopants

NARCIS (Netherlands)

Cachelin, P.; Green, J.P.; Peijs, T.; Heeney, M.; Bastiaansen, C.W.M.

2016-01-01

Accurate monitoring of exposure to organic vapors, such as acetone, is an important part of maintaining a safe working environment and adhering to long- and short-term exposure limits. Here, a novel acetone vapor detection system is described based on the use of a reactive chiral dopant in a nematic

Protective effects of Opuntia ficus-indica extract on ram sperm quality, lipid peroxidation and DNA fragmentation during liquid storage.

Science.gov (United States)

Allai, Larbi; Druart, Xavier; Öztürk, Mehmet; BenMoula, Anass; Nasser, Boubker; El Amiri, Bouchra

2016-12-01

The present study aimed to assess the phenolic composition of the acetone extract from Opuntia ficus indica cladodes (ACTEX) and its effects on ram semen variables, lipid peroxidation and DNA fragmentation during liquid storage at 5°C for up to 72h in skim milk and Tris egg yolk extenders. Semen samples from five rams were pooled extended with Tris-egg yolk (TEY) or skim milk (SM) extenders containing ACTEX (0%, 1%, 2%, 4% and 8%) at a final concentration of 0.8×10 9 sperm/ml and stored for up to 72h at 5°C. The sperm variables were evaluated at different time periods (8, 24, 48 and 72h). Sperm total motility and viability were superior in TEY than in SM whereas the progressive motility, membrane integrity, abnormality and spontaneous lipid peroxidation were greater in SM compared to TEY (P<0.05). The results also indicated that the inclusion of 1% ACTEX in the SM or TEY extender increased the sperm motility, viability, membrane integrity, and decreased the abnormality, lipids peroxidation up to 72h in storage compared to control group. Similarly, even at 72h of storage, 1% ACTEX can efficiently decrease the negative effects of liquid storage on sperm DNA fragmentation (P<0.05). In conclusion, SM and TEY supplemented with 1% of ACTEX can improve the quality of ram semen. Further studies are required to identify the active components in ACTEX involved in its effect on ram sperm preservation. Copyright © 2016 Elsevier B.V. All rights reserved.

Biodegradation of airborne acetone/styrene mixtures in a bubble column reactor.

Science.gov (United States)

Vanek, T; Silva, A; Halecky, M; Paca, J; Ruzickova, I; Kozliak, E; Jones, K

2017-07-29

The ability of a bubble column reactor (BCR) to biodegrade a mixture of styrene and acetone vapors was evaluated to determine the factors limiting the process efficiency, with a particular emphasis on the presence of degradation intermediates and oxygen levels. The results obtained under varied loadings and ratios were matched with the dissolved oxygen levels and kinetics of oxygen mass transfer, which was assessed by determination of k L a coefficients. A 1.5-L laboratory-scale BCR was operated under a constant air flow of 1.0 L.min -1 , using a defined mixed microbial population as a biocatalyst. Maximum values of elimination capacities/maximum overall specific degradation rates of 75.5 gC.m -3 .h -1 /0.197 gC.gdw -1 .h -1 , 66.0 gC.m -3 .h -1 /0.059 gC.gdw -1 .h -1 , and 45.8 gC.m -3 .h -1 /0.027 gC.gdw -1 .h -1 were observed for styrene/acetone 2:1, styrene-rich and acetone-rich mixtures, respectively, indicating significant substrate interactions and rate limitation by biological factors. The BCR removed both acetone and styrene near-quantitatively up to a relatively high organic load of 50 g.m -3 .h -1 . From this point, the removal efficiencies declined under increasing loading rates, accompanied by a significant drop in the dissolved oxygen concentration, showing a process transition to oxygen-limited conditions. However, the relatively efficient pollutant removal from air continued, due to significant oxygen mass transfer, up to a threshold loading rate when the accumulation of acetone and degradation intermediates in the aqueous medium became significant. These observations demonstrate that oxygen availability is the limiting factor for efficient pollutant degradation and that accumulation of intermediates may serve as an indicator of oxygen limitation. Microbial (activated sludge) analyses revealed the presence of amoebae and active nematodes that were not affected by variations in operational conditions.

Potential for free radical-induced lipid peroxidation as a cause of endothelial cell injury in Rocky Mountain spotted fever.

Science.gov (United States)

Silverman, D J; Santucci, L A

1988-01-01

Cells infected by Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, display unusual intracellular morphological changes characterized by dilatation of the membranes of the endoplasmic reticulum and outer nuclear envelope. These changes are consistent with those that might be expected to occur following peroxidation of membrane lipids initiated by oxygen radical species, such as the hydroxyl radical or a variety of organic radicals. Using a fluorescent probe, we have found significantly increased levels of peroxides in human endothelial cells infected by R. rickettsii. Studies with desferrioxamine, an iron chelator effective in preventing formation of the hydroxyl radical from hydrogen peroxide and the superoxide free radical, reduced peroxide levels in infected cells to those found in uninfected cells. This observation suggests that the increased peroxides in infected cells may be lipid peroxides, degradation products of free radical attack on polyenoic fatty acids. The potential for lipid peroxidation as an important mechanism in endothelial cell injury caused by R. rickettsii is discussed. Images PMID:3141280

Investigation of efficiency of air cleaning from acetone using a segmental construction biofilter

Directory of Open Access Journals (Sweden)

Denas Bacevičius

2015-10-01

Full Text Available Volatile organic compounds, e. g. acetone, have a direct impact on climate change, decrease of ozone in the air, and on the growth of greenhouse effect. One of the most popular air purifying methods from VOC is a biological air cleaning. Experimental investigations were conducted to determine the efficiency of the new structure of biofilter with polypropylene plates segments. During the investigations the efficiency of segmental construction biofilter of air purification at different initial concentrations of pollutants was determined. Different concentrations of pollutants were estimated during the acetone dilution with water. During the tests the efficiency of biofilter air purification from acetone vapor and its change under different concentrations of vapors was set. Based on test results, the maximum efficiency of biofilter air purification was up to 93%. Studies have shown that increasing the allowable pollutant concentration, the efficiency of air purification unit decreases. Increasing the concentration of supplied acetone vapor into the biofilter from 232 to 701 mg/m3, cleaning efficiency decreased from 92.8 to 82.3%. Since microorganisms fail to oxidize organic compounds, the filter works better at lower initial concentrations of pollutants.

[Formation of the Pseudomonas aeruginosa PAO1 biofilms in the presence of hydrogen peroxide; the effect of the AiiA gene].

Science.gov (United States)

Pliuta, V A; Andreenko, Iu V; Kuznetsov, A E; Khmel', I A

2013-01-01

In the natural ecosystems, most bacteria exist as specifically organized biofilms attached to various surfaces; the biofilms have a complex architecture and are surrounded by an exopolymeric matrix. The bacteria in the biofilms are extremely resistant to antibacterial agents. The ability of the pathogenic bacteria to produce biofilms causes serious problems in medicine. Therefore, the study of the action of different compounds with antibacterial activity is of great interest. In this work, we studied the effect of the hydrogen peroxide (H2O2) on the formation of biofilms by Pseudomonas aeruginosa PAO1. It was shown that H2O2 in concentrations that do not suppress bacterial growth (or suppress it only weakly) stimulates the formation of the biofilms. At higher concentrations, H2O2 inhibits the formation of the biofilms. In order to determine if the stimulation of the biofilm formation depends on Quorum Sensing (QS) regulation, the plasmid pME6863 containing the heterologous gene aiiA encoding the N-acyl-homoserine lactonase AiiA was introduced into P. aeruginosa PAO1. The synthesis by cells of this enzyme degrading N-acyl-homoserine lactones (AHL), signaling molecules of the QS systems, led to the absence of the stimulation of the biofilm formation by the action of H2O2. This fact indicates that the stimulation of the biofilm formation in the presence of H2O2 depends on the functioning of the QS systems of the gene expression regulation of P. aeruginosa PAO1.

Co-production of acetone and ethanol with molar ratio control enables production of improved gasoline or jet fuel blends.

Science.gov (United States)

Baer, Zachary C; Bormann, Sebastian; Sreekumar, Sanil; Grippo, Adam; Toste, F Dean; Blanch, Harvey W; Clark, Douglas S

2016-10-01

The fermentation of simple sugars to ethanol has been the most successful biofuel process to displace fossil fuel consumption worldwide thus far. However, the physical properties of ethanol and automotive components limit its application in most cases to 10-15 vol% blends with conventional gasoline. Fermentative co-production of ethanol and acetone coupled with a catalytic alkylation reaction could enable the production of gasoline blendstocks enriched in higher-chain oxygenates. Here we demonstrate a synthetic pathway for the production of acetone through the mevalonate precursor hydroxymethylglutaryl-CoA. Expression of this pathway in various strains of Escherichia coli resulted in the co-production of acetone and ethanol. Metabolic engineering and control of the environmental conditions for microbial growth resulted in controllable acetone and ethanol production with ethanol:acetone molar ratios ranging from 0.7:1 to 10.0:1. Specifically, use of gluconic acid as a substrate increased production of acetone and balanced the redox state of the system, predictively reducing the molar ethanol:acetone ratio. Increases in ethanol production and the molar ethanol:acetone ratio were achieved by co-expression of the aldehyde/alcohol dehydrogenase (AdhE) from E. coli MG1655 and by co-expression of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) from Z. mobilis. Controlling the fermentation aeration rate and pH in a bioreactor raised the acetone titer to 5.1 g L(-1) , similar to that obtained with wild-type Clostridium acetobutylicum. Optimizing the metabolic pathway, the selection of host strain, and the physiological conditions employed for host growth together improved acetone titers over 35-fold (0.14-5.1 g/L). Finally, chemical catalysis was used to upgrade the co-produced ethanol and acetone at both low and high molar ratios to higher-chain oxygenates for gasoline and jet fuel applications. Biotechnol. Bioeng. 2016;113: 2079-2087. © 2016 Wiley

Peroxide accumulation and cell death in filamentous fungi induced by contact with a contestant.

Science.gov (United States)

Silar, Philippe

2005-02-01

Podospora anserina and Coprinopsis cinerea (syn. Coprinus cinereus) are endowed with a defence system able to differentiate self vs. non-self and involving the generation of peroxide. Indeed, they produce peroxide when confronted with a filamentous fungus, only in non-self confrontations. Both species are not able to recognize yeasts and show a differential response to bacteria. The accumulation of peroxides in the ascomycete Podospora anserina requires an NADPH oxidase and a MAP kinase cascade, previously shown to be involved in fruit body formation, cell differentiation and cell degeneration. Confrontation is accompanied by the death of the contestant hyphae only in specific combinations of species. As in animals and plants, data suggest that peroxide is likely involved in signalling rather than playing a direct toxic role. Fungi display more complex behaviours than generally acknowledged, i.e. they are able to recognize potential contestants and built up defence reactions involving evolutionary conserved enzymes.

N,N,N′,N′-Tetramethyl-N′′-[2-(trimethylazaniumylethyl]guanidinium bis(tetraphenylborate acetone disolvate

Directory of Open Access Journals (Sweden)

Ioannis Tiritiris

2016-02-01

Full Text Available The asymmetric unit of the title solvated salt, C10H26N42+·2C24H20B−·2C3H6O, comprises one cation, two tetraphenylborate ions and two acetone solvent molecules. The N and methyl C atoms of the terminal trimethylammonium group are disordered over two sets of sites, with a refined occupancy ratio of 0.846 (3:0.154 (3. The C—N bond lengths in the central C3N unit of the guanidinium ion range between 1.3308 (16 and 1.3508 (16 Å, indicating a degree of double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal–planar geometry and the positive charge is delocalized in the CN3 plane. The C—N bond lengths in the terminal trimethylammonium group have values close to that of a typical single bond, and the second positive charge is localized there. In the crystal, the guanidinium ion is connected by N—H...O and C—H...O hydrogen bonds with the acetone molecules. C—H...π interactions are present between the guanidinium H atoms and the phenyl rings of the tetraphenylborate ions, leading to the formation of a two-dimensional supramolecular pattern along the bc plane.

Radical Scavenging by Acetone: A New Perspective to Understand Laccase/ABTS Inactivation and to Recover Redox Mediator.

Science.gov (United States)

Liu, Hao; Zhou, Pandeng; Wu, Xing; Sun, Jianliang; Chen, Shicheng

2015-11-04

The biosynthetic utilization of laccase/mediator system is problematic because the use of organic cosolvent causes significant inhibition of laccase activity. This work explored how the organic cosolvent impacts on the laccase catalytic capacity towards 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in aqueous solution. Effects of acetone on the kinetic constants of laccase were determined and the results showed Km and Vmax varied exponentially with increasing acetone content. Acetone as well as some other cosolvents could transform ABTS radicals into its reductive form. The content of acetone in media significantly affected the radical scavenging rates. Up to 95% of the oxidized ABTS was successfully recovered in 80% (v/v) acetone in 60 min. This allows ABTS recycles at least six times with 70%-75% of active radicals recovered after each cycle. This solvent-based recovery strategy may help improve the economic feasibility of laccase/ABTS system in biosynthesis.

Solute-solvent complex switching dynamics of chloroform between acetone and dimethylsulfoxide-two-dimensional IR chemical exchange spectroscopy.

Science.gov (United States)

Kwak, Kyungwon; Rosenfeld, Daniel E; Chung, Jean K; Fayer, Michael D

2008-11-06

Hydrogen bonds formed between C-H and various hydrogen bond acceptors play important roles in the structure of proteins and organic crystals, and the mechanisms of C-H bond cleavage reactions. Chloroform, a C-H hydrogen bond donor, can form weak hydrogen-bonded complexes with acetone and with dimethylsulfoxide (DMSO). When chloroform is dissolved in a mixed solvent consisting of acetone and DMSO, both types of hydrogen-bonded complexes exist. The two complexes, chloroform-acetone and chloroform-DMSO, are in equilibrium, and they rapidly interconvert by chloroform exchanging hydrogen bond acceptors. This fast hydrogen bond acceptor substitution reaction is probed using ultrafast two-dimensional infrared (2D-IR) vibrational echo chemical exchange spectroscopy. Deuterated chloroform is used in the experiments, and the 2D-IR spectrum of the C-D stretching mode is measured. The chemical exchange of the chloroform hydrogen bonding partners is tracked by observing the time-dependent growth of off-diagonal peaks in the 2D-IR spectra. The measured substitution rate is 1/30 ps for an acetone molecule to replace a DMSO molecule in a chloroform-DMSO complex and 1/45 ps for a DMSO molecule to replace an acetone molecule in a chloroform-acetone complex. Free chloroform exists in the mixed solvent, and it acts as a reactive intermediate in the substitution reaction, analogous to a SN1 type reaction. From the measured rates and the equilibrium concentrations of acetone and DMSO, the dissociation rates for the chloroform-DMSO and chloroform-acetone complexes are found to be 1/24 ps and 1/5.5 ps, respectively. The difference between the measured rate for the complete substitution reaction and the rate for complex dissociation corresponds to the diffusion limited rate. The estimated diffusion limited rate agrees well with the result from a Smoluchowski treatment of diffusive reactions.

The use of acetone to enhance the infiltration of HA nanoparticles into a demineralized dentin collagen matrix.

Science.gov (United States)

Besinis, Alexandros; van Noort, Richard; Martin, Nicolas

2016-03-01

This study investigates the role of acetone, as a carrier for nano-hydroxyapatite (nano-HA) in solution, to enhance the infiltration of fully demineralized dentin with HA nanoparticles (NPs). Dentin specimens were fully demineralized and subsequently infiltrated with two types of water-based nano-HA solutions (one containing acetone and one without). Characterization of the dentin surfaces and nano-HA particles was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface wettability and infiltration capacity of the nano-HA solutions were quantified by means of contact angle measurements and energy dispersive X-ray spectroscopy (EDS), respectively. Contact angle measurements were taken at baseline and repeated at regular intervals to assess the effect of acetone. The P and Ca levels of infiltrated dentin specimens were measured and compared to sound dentin and non-infiltrated controls. The presence of acetone resulted in an eight-fold decrease in the contact angles of the nano-HA solutions recorded on the surface of demineralized dentin compared to nano-HA solutions without acetone (one-way ANOVA, pacetone. Infiltration of demineralized dentin with the nano-HA solution containing acetone restored the lost mineral content by 50%, whereas the mean mineralization values for P and Ca in dentin treated with the acetone-free nano-HA solution were less than 6%. Acetone was shown to act as a vehicle to enhance the capacity to infiltrate demineralized dentin with HA NPs. The successful infiltration of dentin collagen with HA NPs provides a suitable scaffold, whereby the infiltrated HA NPs have the potential to act as seeds that may initiate heterogenous mineral growth when exposed to an appropriate mineral-rich environment. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Polypyrrole nanoparticles fabricated via Triton X-100 micelles template approach and their acetone gas sensing property

Energy Technology Data Exchange (ETDEWEB)

Li, Fake; Li, Hang [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Jiang, Hongmin [26th Research Institute, Chinese Electronics Scientific and Technical Group Company, Chongqing 400060 (China); Zhang, Kejun; Chang, Kai; Jia, Shuangrong; Jiang, Wenbin; Shang, Ya; Lu, Weiping [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Deng, Shaoli, E-mail: dengsl072@yahoo.com.cn [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China); Chen, Ming, E-mail: chenming1971@yahoo.com [Department of Clinical Laboratory Medcine, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042 (China)

2013-09-01

Nano-scaled polypyrrole (PPy) particles have been successfully synthesized with the help of Triton X-100 micelles via soft template approach. The polypyrrole nanoparticles have been spin-coated on surface acoustic wave (SAW) transducers to demonstrate their sensing capability toward acetone gas exposure. Field Emission Scanning Electron Microscopes (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy have been utilized to characterize these PPy nanoparticles. The PPy nanoparticles have an average diameter of 95 nm. The responses of the sensors are linearly associated with the acetone concentrations in the range from 5.5 ppm to 80 ppm. In response to 5.5 ppm acetone exposure, the response and recovery time are 9 s and 8.3 s, respectively. SAW sensors coated with PPy nanoparticles were potentially useful to detect acetone.

Polypyrrole nanoparticles fabricated via Triton X-100 micelles template approach and their acetone gas sensing property

International Nuclear Information System (INIS)

Li, Fake; Li, Hang; Jiang, Hongmin; Zhang, Kejun; Chang, Kai; Jia, Shuangrong; Jiang, Wenbin; Shang, Ya; Lu, Weiping; Deng, Shaoli; Chen, Ming

2013-01-01

Nano-scaled polypyrrole (PPy) particles have been successfully synthesized with the help of Triton X-100 micelles via soft template approach. The polypyrrole nanoparticles have been spin-coated on surface acoustic wave (SAW) transducers to demonstrate their sensing capability toward acetone gas exposure. Field Emission Scanning Electron Microscopes (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy have been utilized to characterize these PPy nanoparticles. The PPy nanoparticles have an average diameter of 95 nm. The responses of the sensors are linearly associated with the acetone concentrations in the range from 5.5 ppm to 80 ppm. In response to 5.5 ppm acetone exposure, the response and recovery time are 9 s and 8.3 s, respectively. SAW sensors coated with PPy nanoparticles were potentially useful to detect acetone.

NASOPHARYNGEAL CONCENTRATIONS IN THE HUMAN VOLUNTEER BREATHING ACETONE

Science.gov (United States)

In an effort to examine the absorption of a common chemical into the nasopharyngeal region in humans, a 57 year old male volunteer inhaled uniformly labeled 13C-acetone at 1.4 ppm for 30 min while performing different breathing maneuvers; nose inhale, nose exhale (NINE); mouth ...

Thermometric sensing of peroxide in organic media. Application to monitor the stability of RBP-retinol-HRP complex.

Science.gov (United States)

Ramanathan, K; Jönsson, B R; Danielsson, B

2000-08-01

The stability of horseradish peroxidase (HRP) in aqueous and organic solvents is applied to develop a simple thermometric procedure to detect the binding of retinoic acid-HRP conjugate to retinol binding protein (RBP). Butanone peroxide (BP) in organic phase and hydrogen peroxide in aqueous phase is detected thermometrically on a HRP column, immobilized by cross-linking with glutaraldehyde on controlled pore glass (CPG). Acetone, acetonitrile, methanol, and 2-butanol are used for detection of BP, in the flow injection analysis (FIA) mode. A linear range between 1 and 50 mM BP is obtained in all the organic solvents with a precision of 5-7% (CV%). The magnitude and nature of the thermometric response is significantly different in each organic solvent. The stability of HRP in the organic phase is used to study the stability of a retinoic acid-HRP conjugate bound to immobilized RBP. The response of HRP (to 20 mM BP) in the retinoic acid-HRP conjugate is used as an indicator of the stability of the RBP-retinoic acid-HRP complex, after challenges with various organic/aqueous solvents. Both immobilized HRP and RBP are stable at least for 6 months. The effect of o-phenylene diamine on the thermometric response of HRP is also investigated. A scheme for the design of a thermometric retinol (vitamin A) biosensor is proposed.

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

Science.gov (United States)

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.

An acetone microsensor with a ring oscillator circuit fabricated using the commercial 0.18 μm CMOS process.

Science.gov (United States)

Yang, Ming-Zhi; Dai, Ching-Liang; Shih, Po-Jen

2014-07-17

This study investigates the fabrication and characterization of an acetone microsensor with a ring oscillator circuit using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The acetone microsensor contains a sensitive material, interdigitated electrodes and a polysilicon heater. The sensitive material is α-Fe2O3 synthesized by the hydrothermal method. The sensor requires a post-process to remove the sacrificial oxide layer between the interdigitated electrodes and to coat the α-Fe2O3 on the electrodes. When the sensitive material adsorbs acetone vapor, the sensor produces a change in capacitance. The ring oscillator circuit converts the capacitance of the sensor into the oscillation frequency output. The experimental results show that the output frequency of the acetone sensor changes from 128 to 100 MHz as the acetone concentration increases 1 to 70 ppm.

Gallium-67 citrate used as a tracer of acetone production routes

International Nuclear Information System (INIS)

Mesquita, Carlos Henrique de; Calvo, Wilson A.P.; Aoki, Pedro E.; Silva, Valdir Cosmos da; Haraguchi, Marcio I.; Velo, Alexandre F.; Alvarez, Alexandre G.; Paixão, Leticia B.; Hamada, Margarida M.

2017-01-01

In this work the pathway of the chemical product and the kinetics parameters were evaluated in a laboratory plant settled, using 40 GBq of 67 Ga citrate as radiotracer and 18 NaI(Tl) radiation detectors. The AnaComp program was used to estimate the kinetic parameters of the acetone production. The yield of the acetone production was estimated by the percentage ratio between the areas under the curve (AUC) of the curve profiles of the final product compartment divided by the concentration found inside the chemical reactor whose result was 87% yield during the first 30 minutes of reaction. (author)

Gallium-67 citrate used as a tracer of acetone production routes

Energy Technology Data Exchange (ETDEWEB)

Mesquita, Carlos Henrique de; Calvo, Wilson A.P.; Aoki, Pedro E.; Silva, Valdir Cosmos da; Haraguchi, Marcio I.; Velo, Alexandre F.; Alvarez, Alexandre G.; Paixão, Leticia B.; Hamada, Margarida M., E-mail: chmesqui@usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

In this work the pathway of the chemical product and the kinetics parameters were evaluated in a laboratory plant settled, using 40 GBq of {sup 67}Ga citrate as radiotracer and 18 NaI(Tl) radiation detectors. The AnaComp program was used to estimate the kinetic parameters of the acetone production. The yield of the acetone production was estimated by the percentage ratio between the areas under the curve (AUC) of the curve profiles of the final product compartment divided by the concentration found inside the chemical reactor whose result was 87% yield during the first 30 minutes of reaction. (author)

Detection of hydrogen peroxide with graphyne

Science.gov (United States)

Majidi, R.; Karami, A. R.

2013-12-01

The effect of hydrogen peroxide on the electronic properties of graphyne has been investigated to explore the possibility of using graphyne based biosensor. We have used density functional theory to study the electronic properties of γ-graphyne in the presence of different number of hydrogen peroxide. The optimal adsorption position, orientation, and distance of hydrogen peroxide adsorbed on the graphyne sheet have been determined by calculating adsorption energy. It is found that γ-graphyne which is an intrinsic semiconductor becomes an n-type semiconductor due to the presence of hydrogen peroxide. The energy band gap of γ-graphyne is decreased by increasing the number of hydrogen peroxide. The results demonstrate that γ-graphyne is a promising candidate for biosensor application because of its electrical sensitivity to hydrogen peroxide.

Acetone gas-sensing properties of multiple-networked Pd-decorated Bi_2O_3 nanorod sensors

International Nuclear Information System (INIS)

Park, Sung Hoon; Kim, Soo Hyun; Lee, Sang Min; Lee, Chong Mu

2015-01-01

This study examined the sensing properties of Bi_2O_3 nanorods decorated with Pd nanoparticles. Pd-decorated β-Bi_2O_3 nanorods were prepared by immersing the Bi_2O_3 nanorods in ethanol/(50 mM)PdCl_2 solution followed by UV irradiation and annealing. The Bi_2O_3 nanorods decorated with Pd nanoparticles showed faster and stronger response to acetone gas than the pristine Bi_2O_3 nanorods. Interestingly, the difference in response time between the Pd-decorated Bi_2O_3 nanorod sensor and pristine Bi_2O_3 nanorod sensor increased with increasing the acetone gas concentration. In contrast, the difference in recovery time between the two nanorod sensors decreased with increasing the acetone gas concentration. This difference can be explained using the chemical mechanism. The underlying mechanism for the enhanced response of the Bi_2O_3 nanorods decorated with Pd nanoparticles to acetone gas is also discussed

Lipid Peroxidation and Antioxidant Status in Preeclampsia

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Rokeya Begum

2011-07-01

Full Text Available Background: Preeclampsia is the most common and major medical complication of pregnancy with a high incidence of maternal and foetal morbidity and mortality. During pregnancy abnormally increased lipid peroxidation and free radical formation as well as significantly decreased antioxidants production in maternal blood may lead to pathogenesis of preeclampsia. So, we designed this study as little information is known about lipid peroxidation and antioxidant level in preeclampsia. Objectives: To assess the serum malondialdehyde (MDA level as a lipid peroxidation product and vitamin E (antioxidant level in women with preeclampsia as well as in normal pregnancy and to compare the values. Materials and Methods: The study was conducted on 60 women aged from 25 to 35 years in the department of Biochemistry, Budi Kemuliaan Maternity Hospital (BKMH in Jakarta during the period April to July 2004. Twenty were normal pregnant women and 20 were preeclamptic patients. For comparison age matched 20 apparently healthy nonpregnant women were included in the study. The study subjects were selected from outpatient department (OPD of Obstetrics and Gynaecology of BKMH in Jakarta. Serum MDA (lipid peroxidation product level was measured by thiobarbituric acid reactive substances assay (TBRAS method and vitamin E was estimated spectroflurometrically. Data were analyzed by unpaired Student’s t test between the groups by using SPSS version 12. Results: The mean serum MDA levels were significantly higher in normal pregnancy and also in preeclampsia than that of nonpregnant control group women (p<0.001. Again the serum MDA levels were significantly higher in preeclampsia than that of normal pregnant women (p<0.001. The serum vitamin E levels were significantly lower in preeclampsia and also in normal pregnancy than that of nonpregnant control women (p<0.001. Moreover, the serum vitamin E levels were significantly lower in preeclampsia compared to that of normal

Thermal stabilities of various rubber vulcanization cured by sulfur, peroxide and gamma radiation

International Nuclear Information System (INIS)

Basfar, A.A.; Shamshad Ahmed; Abdel Aziz, M.M.

1999-01-01

Sulfur and peroxide-cured rubber vulcanizates of NR and EPDM were obtained by blending the elastomers with fillers, antioxidants and appropriate accelerators, followed by vulcanization at 150 - 160 degree C. Blends of the same elastomers with appropriate co-agents and additives were also cured by gamma radiation at 150 and 200 kGy. A comparison of the thermal stabilities of these vulcanizates prepared by different curing techniques has been made by thermogravimetric analysis (TGA), assessed on the basis of comparison of DTG peak maxima, temperature for loss of 50% mass and actual thermal curves. The comparison reveals that the sulfur-cured vulcanizates are less thermally stable than their peroxide-cured counterparts. This may be attributed to the presence of a stronger C-C bond in case of peroxide-cured vulcanizates compared to weaker C-S sub x-C bond in case of sulfur-cured vulcanizates. However, compared to peroxide-cured vulcanizates, radiation-cured formulations demonstrated much improved thermal stability. This may originate from the existence of more uniformly distributed crosslinks and the enhanced rate of crosslink formation in the radiation process as compared to peroxide curing. In all the formulations whether sulfur, peroxide or radiation-cured, the natural rubber vulcanizates were found to be thermally much inferior to the synthetic contender, EPDM. Influence of variation of the amount of co-agent and other additives on the thermal stabilities of formulations of radiation cured NR and EPDM vulcanizates was also investigated

Lidar/DIAL detection of acetone at 3.3 μm by a tunable OPO laser system

International Nuclear Information System (INIS)

Puiu, A; Fiorani, L; Borelli, R; Pistilli, M; Palucci, A; Rosa, O

2014-01-01

In this paper we report, for the first time to our knowledge, on lidar/DIAL detection of acetone vapors at 3.3 μm by means of an optical parametric tunable laser system. After a preliminary spectroscopic study in an absorption cell, the feasibility of a differential absorption (DIAL) lidar for the detection of acetone vapors has been investigated in the laboratory, simulating the experimental conditions of a field campaign. Having in mind measurements in a real scenario, a study of possible atmospheric intereferents has been performed, looking for all known compounds that share acetone IR absorption in the spectral band selected for its detection. Possible interfering species from urban and industrial atmospheres were investigated and limits of acetone detection in both environments were identified. This study confirmed that a lidar system can detect a low concentration of acetone at considerable distances. (paper)

an oxalate-peroxide complex used in the preparation of doped barium titanate

NARCIS (Netherlands)

van der Gijp, S.; Winnubst, Aloysius J.A.; Verweij, H.

1998-01-01

A method is described for the preparation of homogeneously doped barium titanate, which can be applied in non-linear dielectric elements. Ba and Ti salts are dissolved, mixed with hydrogen peroxide and added to a solution of ammonium oxalate, resulting in the formation of an insoluble peroxo-oxalate

Synthesis and phototoxicity of isomeric 7,9-diglutathione pyrrole adducts: Formation of reactive oxygen species and induction of lipid peroxidation

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Liang Ma

2015-09-01

Full Text Available Pyrrolizidine alkaloids (PAs are hepatotoxic, genotoxic, and carcinogenic in experimental animals. Because of their widespread distribution in the world, PA-containing plants are probably the most common poisonous plants affecting livestock, wildlife, and humans. Upon metabolism, PAs generate reactive dehydro-PAs and other pyrrolic metabolites that lead to toxicity. Dehydro-PAs are known to react with glutathione (GSH to form 7-GSH-(+/−-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (7-GS-DHP in vivo and in vitro and 7,9-diGS-DHP in vitro. To date, the phototoxicity of GS-DHP adducts has not been well studied. In this study, we synthesized 7-GS-DHP, a tentatively assigned 9-GS-DHP, and two enantiomeric 7,9-diGS-DHP adducts by reaction of dehydromonocrotaline with GSH. The two 7,9-diGS-DHPs were separated by high performance liquid chromatography (HPLC and their structures were characterized by 1H nuclear magnetic resonance (NMR and 1H–1H correlation spectroscopy (COSY NMR spectral analysis. Photoirradiation of 7-GS-DHP, 9-GS-DHP, and the two 7,9-diGS-DHPs as well as dehydromonocrotaline, dehydroheliotrine, and the 7-R enantiomer of DHP (DHR, by UVA light at 0 J/cm2, 14 J/cm2, and 35 J/cm2 in the presence of a lipid, methyl linoleate, all resulted in lipid peroxidation in a light dose-responsive manner. The levels of lipid peroxidation induced by the two isomeric 7,9-diGS-DHPs were significantly higher than that by 7-GS-DHP and 9-GS-DHP. When 7,9-diGS-DHP was irradiated in the presence of sodium azide (NaN3, the level of lipid peroxidation decreased; lipid peroxidation was enhanced when methanol was replaced by deuterated methanol. These results suggest that singlet oxygen is a product induced by the irradiation of 7,9-diGS-DHP. When irradiated in the presence of superoxide dismutase (SOD, the level of lipid peroxidation decreased, indicating that lipid peroxidation is also mediated by superoxide. These results indicate that lipid

An acetone breath analyzer using cavity ringdown spectroscopy: an initial test with human subjects under various situations

International Nuclear Information System (INIS)

Wang, Chuji; Surampudi, Anand B

2008-01-01

We have developed a portable breath acetone analyzer using cavity ringdown spectroscopy (CRDS). The instrument was initially tested by measuring the absorbance of breath gases at a single wavelength (266 nm) from 32 human subjects under various conditions. A background subtraction method, implemented to obtain absorbance differences, from which an upper limit of breath acetone concentration was obtained, is described. The upper limits of breath acetone concentration in the four Type 1 diabetes (T1D) subjects, tested after a 14 h overnight fast, range from 0.80 to 3.97 parts per million by volume (ppmv), higher than the mean acetone concentration (0.49 ppmv) in non-diabetic healthy breath reported in the literature. The preliminary results show that the instrument can tell distinctive differences between the breath from individuals who are healthy and those with T1D. On-line monitoring of breath gases in healthy people post-exercise, post-meals and post-alcohol-consumption was also conducted. This exploratory study demonstrates the first CRDS-based acetone breath analyzer and its potential application for point-of-care, non-invasive, diabetic monitoring

Development of biological and nonbiological explanations for the Viking label release data. [hydrogen peroxide theory

Science.gov (United States)

1980-01-01

The plausibility that hydrogen peroxide, widely distributed within the Mars surface material, was responsible for the evocative response obtained by the Viking Labeled Release (LR) experiment on Mars was investigated. Although a mixture of gamma Fe2O3 and silica sand stimulated the LR nutrient reaction with hydrogen peroxide and reduced the rate of hydrogen decomposition under various storage conditions, the Mars analog soil prepared by the Viking Inorganic Analysis Team to match the Mars analytical data does not cause such effects. Nor is adequate resistance to UV irradiation shown. On the basis of the results and consideration presented while the hydrogen peroxide theory remains the most, if not only, attractive chemical explanation of the LR data, it remains unconvincing on critical points. Until problems concerning the formation and stabilization of hydrogen peroxide on the surface of Mars can be overcome, adhere to the scientific evidence requires serious consideration of the biological theory.

An unprecedented process of peroxide ion formation and its localization in the crystal structure of strontium peroxy-hydroxyapatite Sr{sub 10}(PO{sub 4}){sub 6}(O{sub 2}){sub x}(OH){sub 2-2x}

Energy Technology Data Exchange (ETDEWEB)

Kazin, Pavel E. [Department of Chemistry, Moscow State University (Russian Federation); Zykin, Mikhail A. [Department of Materials Science, Moscow State University (Russian Federation); Dinnebier, Robert E.; Magdysyuk, Oxana V.; Jansen, Martin [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Tretyakov, Yury D. [Department of Chemistry, Moscow State University (Russian Federation); Department of Materials Science, Moscow State University (Russian Federation)

2012-05-15

Formation of strontium peroxy-hydroxyapatite solid solution Sr{sub 10}(PO{sub 4}){sub 6}(O{sub 2}){sub x}(OH){sub 2-2x} was studied on annealing the hydroxyapatite in the temperature range 900-1350 C in oxygen, air, and argon atmosphere. The redox process was found to display unprecedented features: (i) the peroxide content increased with raising temperature, (ii) the peroxide content remained substantial even at a low oxygen pressure of 1.013 Pa, (iii) the peroxide content was extremely persistent, and even at a temperature of 1350 C in oxygen atmosphere the peroxide groups substituted more than two-third of the original hydroxide groups. Chemical processes consistent with these features are suggested. In the UV/Vis spectrum, an absorption peak at 300 nm was recorded, which was attributed to an electronic transition in the peroxide ion, since its intensity depended linearly on the peroxide content. In the Raman spectra, a weak band at 765-770 cm{sup -1} was ascribed to symmetric stretching vibrations of O{sub 2}{sup 2-}. The structures of the compounds were refined from powder X-ray diffraction data using the Rietveld method supported by a maximum entropy method (MEM) electron density calculation. The peroxide ions are localized in the center of the hexagonal channel. At high concentration they tend to order with the associated vacancies along the channels. As a consequence, the width of the channel sections varies, the PO{sub 4} tetrahedra tilt, and the remote strontium atoms are displaced leading to changes in their coordination. Generally, the peroxide for hydroxide substitution manifests itself in the reduction of the overall channel diameter (and its volume), while the volume occupied by out-of-channel ions remains the same. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Acetone photophysics at 282 nm excitation at elevated pressure and temperature. II: Fluorescence modeling

Science.gov (United States)

Hartwig, Jason; Raju, Mandhapati; Sung, Chih-Jen

2017-07-01

This is the second in a series of two papers that presents an updated fluorescence model and compares with the new experimental data reported in the first paper, as well as the available literature data, to extend the range of acetone photophysics to elevated pressure and temperature conditions. This work elucidates the complete acetone photophysical model in terms of each and every competing radiative and non-radiative rate. The acetone fluorescence model is then thoroughly examined and optimized based on disparity with recently conducted elevated pressure and temperature photophysical calibration experiments. The current work offers insight into the competition between non-radiative and vibrational energy decay rates at elevated temperature and pressure and proposes a global optimization of model parameters from the photophysical model developed by Thurber (Acetone Laser-Induced Fluorescence for Temperature and Multiparameter Imaging in Gaseous Flows. PhD thesis, Stanford University Mechanical Engineering Department, 1999). The collisional constants of proportionality, which govern vibrational relaxation, are shown to be temperature dependent at elevated pressures. A new oxygen quenching rate is proposed which takes into account collisions with oxygen as well as the oxygen-assisted intersystem crossing component. Additionally, global trends in ketone photophysics are presented and discussed.

Dehalogenation, degradation and mineralization of diuron by peroxone (peroxide/ozone) treatment.

Science.gov (United States)

Catalkaya, Ebru Cokay; Kargi, Fikret

2009-05-01

Removal of diuron from aqueous solution by peroxone (hydrogen peroxide/ozone) oxidation was investigated using Box-Behnken statistical experiment design and the response surface methodology (RSM). Effects of diuron, H(2)O(2) concentrations and initial pH on the extent of diuron, total organic carbon (TOC) and adsorbable organic halogen (AOX) removals were investigated. Ozone dose was kept constant at 45 mg min(-1). Optimum reagent doses yielding the highest diuron, TOC and AOX removals were also determined. Hydrogen peroxide dose and pH were the most effective parameters for pesticide removal while hydrogen peroxide dose had the most significant effect on AOX removal (dehalogenation). All parameters affected mineralization (TOC removal) of diuron. Nearly complete removal of diuron was achieved within 5 minutes, while complete mineralization and dehalogenation were not achieved even within 60 minutes at high diuron doses indicating formation of some intermediate products. The optimal H(2)O(2)/pH/diuron ratio resulting in the maximum pesticide (100%), TOC (82%) and AOX (95%) removal was found to be 340/8/10.

Rapid and selective detection of acetone using hierarchical ZnO gas sensor for hazardous odor markers application

International Nuclear Information System (INIS)

Jia, Qianqian; Ji, Huiming; Zhang, Ying; Chen, Yalu; Sun, Xiaohong; Jin, Zhengguo

2014-01-01

Highlights: • ZnO spheres fabricated via solvothermal method are with (0 0 2) polar facet exposed. • Response time of ZnO sensor for detecting 100 ppm acetone is as short as 3 s. • R a /R g toward 100 ppm acetone is 33 when operated at 230 °C. • ZnO sensor exhibits good selectivity against other toxic gases and water vapor. • Porous structure and exposure of polar facet contribute to good sensing properties. - Abstract: Hierarchical nanostructured ZnO dandelion-like spheres were synthesized via solvothermal reaction at 200 °C for 4 h. The products were pure hexagonal ZnO with large exposure of (0 0 2) polar facet. Side-heating gas sensor based on hierarchical ZnO spheres was prepared to evaluate the acetone gas sensing properties. The detection limit to acetone for the ZnO sensor is 0.25 ppm. The response (R a /R g ) toward 100 ppm acetone was 33 operated at 230 °C and the response time was as short as 3 s. The sensor exhibited remarkable acetone selectivity with negligible response toward other hazardous gases and water vapor. The high proportion of electron depletion region and oxygen vacancies contributed to high gas response sensitivity. The hollow and porous structure of dandelion-like ZnO spheres facilitated the diffusion of gas molecules, leading to a rapid response speed. The largely exposed (0 0 2) polar facets could adsorb acetone gas molecules easily and efficiently, resulting in a rapid response speed and good selectivity of hierarchical ZnO spheres gas sensor at low operating temperature

First discovery of acetone extract from cottonseed oil sludge as a novel antiviral agent against plant viruses.

Science.gov (United States)

Zhao, Lei; Feng, Chaohong; Hou, Caiting; Hu, Lingyun; Wang, Qiaochun; Wu, Yunfeng

2015-01-01

A novel acetone extract from cottonseed oil sludge was firstly discovered against plant viruses including Tobacco mosaic virus (TMV), Rice stripe virus (RSV) and Southern rice black streaked dwarf virus (SRBSDV). Gossypol and β-sitosterol separated from the acetone extract were tested for their effects on anti-TMV and analysed by nuclear magnetic resonance (NMR) assay. In vivo and field trials in different geographic distributions and different host varieties declared that this extract mixture was more efficient than the commercial agent Ningnanmycin with a broad spectrum of anti-plant-viruses activity. No phytotoxic activity was observed in the treated plants and environmental toxicology showed that this new acetone extract was environmentally friendly, indicating that this acetone extract has potential application in the control of plant virus in the future.

[Modification of the pattern of fatty acids of erythrocytes’ membranes due to the acetone intoxication].

Science.gov (United States)

Momot, T V; Kushnerova, N F; Rakhmanin, Yu A

Results of the study of the impact of acetone intoxication on the fatty acids pattern of the general lipids of erythrocytes’ membranes in rats are presented. The inhalation exposure of acetone was carried out in the inoculation chamber with the volume of 100 liters. The chamber was designed for the type of B.A. Kurlyandsky with self-contained system of purification and air regeneration and specified parameters of temperature (20-22С) and air humidity. The flow rate of the air and aerosolized acetone passed through the chamber accounted of 10 liters/min. Concentration of acetone in the chamber was sustained at the level of 206 ± 3,9 mg/m that corresponds to maximum permissible concentration for acetone vapor in the air of a working area. The time of exposure was 6 hours per day for 3 weeks in a monotonous mode, excluding weekend, and was based upon specific parameters of environment simulation in industry. The acetone impact was shown to be accompanied by the gain in the quantity of all kinds of saturated fatty acids and the fall of unsaturated fatty acids in general lipids of erythrocytes ’ membranes in rats and in the structure ofphospholipid fractions. In the content of phosphatydilcholine and phosphatydilethanolamine, as a basic structural phospholipids of biological membranes, there was noted the increase in palmitic and stearic acids. In the range offatty acids of the n-6 family the amount of linoleic and arachidonic acids decreased. In the array of fatty acids of the n-3 family the content of linolenic, eicosapentaenoic and docosahexaenoic acids (n-3 family) declined. Redistribution of fatty acids in the erythrocytes membrane towards to such alteration in quantity as the increasing of saturation and decreasing of the unsaturated fatty acids supposes the change of its physical and chemical properties, permeability, lability and complexity of passing erythrocyte via microcircular channels.

Some problems of local production of acetone and butanol

Energy Technology Data Exchange (ETDEWEB)

Fang, C; Chang, Y P

1959-01-01

Conditions of laboratory and plant cultivation of acetone-butanol fermentation bacteria are considered (effects of pH of the medium, temperature, and starch content in raw material on yield of fermentation products) and also the conditions of isolation of the final products produced.

In vitro antimycobacterial activity of acetone extract of Glycyrrhiza glabra

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Swapna S. Nair

2015-08-01

Full Text Available Context: Glycyrrhiza glabra (licorice has been used since ages as expectorant, antitussive and demulcent. G. glabra has been indicated in Ayurveda as an antimicrobial agent for the treatment of respiratory infections and tuberculosis. Aims: To evaluate the antimycobacterial activity of acetone extract of G. glabra by in vitro techniques. Methods: The anti-tubercular activity of acetone extract of G. glabra, obtained by Soxhlet extraction, was evaluated against Mycobacterium tuberculosis H37Rv (ATCC 27294. The in vitro anti-tubercular activity was determined by Resazurin Microtiter Plate Assay (REMA and colony count method. Further, the anti-tubercular activity of acetone extract of G. glabra was determined in human macrophage U937 cell lines and was compared against that of the standard drugs isoniazid, rifampicin and ethambutol. Results: G. glabra extract showed significant activity against Mycobacterium tuberculosis, when evaluated by REMA/colony count methods and in U937 human macrophage cell lines infected with Mycobacterium tuberculosis H37Rv. The activity of the extract was comparable to those of standard drugs. It was observed that the extract showed time and concentration dependent antimycobacterial activity. Conclusions: The present study reveals that G. glabra extract has promising anti-tubercular activity by preliminary in vitro techniques and in U937 macrophage cell line. Therefore, it has the definite potential to be developed as an affordable, cost-effective drug against tuberculosis.

Self-organization of nickel nanoparticles dispersed in acetone: From separate nanoparticles to three-dimensional superstructures

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I. Hernández-Pérez

2017-02-01

Full Text Available Sonochemical synthesis of monodisperse nickel nanoparticles (Ni-NPs by reduction of Ni acetylacetonate in the presence of polyvinylpyrrolidone stabilizer is reported. The Ni-NPs size is readily controlled to 5 nanometer diameter with a standard deviation of less than 5%. The as-prepared Ni-NPs sample was dispersed in acetone, for 4 weeks. For structural analysis was not applied to a magnetic field or heat treatment as key methods to direct the assembly. The transition from separate Ni-NPs into self-organization of three dimensions (3D superstructures was studied by electron microscopy. Experimental analysis suggests that the translation and rotation movement of the Ni-NPs are governed by magnetic frustration which promotes the formation of different geometric arrangements in two dimensions (2D. The formation of 3D superstructures is confirmed from scanning electron microscopy revealing a layered domain that consists of staking of several monolayers having multiple well-defined supercrystalline domains, enabling their use for optical, electronic and sensor applications.

Hydrate phase equilibria of furan, acetone, 1,4-dioxane, TBAC and TBAF

International Nuclear Information System (INIS)

Kamran-Pirzaman, Arash; Pahlavanzadeh, Hassan; Mohammadi, Amir H.

2013-01-01

Highlights: • Experimental hydrate dissociation conditions are reported for CO 2 /methane + some water soluble/insoluble hydrate formers. • An isochoric pressure-search method was used to generate the experimental data. • The data are compared with the corresponding literature data in the presence of pure water. • The hydrate promotion effects of acetone, 1,4-dioxane, furan, TBAC and TBAF are discussed. -- Abstract: In this communication, we first report experimental hydrate dissociation pressures for the methane/carbon dioxide + furan/acetone/1,4-dioxane + water and the methane + tetra n-butyl ammonium chloride (TBAC) + water as well as the carbon dioxide + tetra n-butyl ammonium floride (TBAF) + water systems in the temperature ranges of (269.9 to 303.3) K. An isochoric pressure-search method was used to generate the experimental data. The hydrate dissociation data are compared with the corresponding literature data, if exists, and the literature data in the presence of pure water and acceptable agreement is observed. A discussion is made on hydrate promotion effects of acetone, 1,4-dioxane, furan, TBAC and TBAF

Spectroscopic studies of europium-tetracyclines complexes and their applications in detection of hydrogen peroxide and urea peroxide

International Nuclear Information System (INIS)

Grasso, Andrea Nastri

2010-01-01

In this work were studied the spectroscopic properties of trivalent europium ion complexed with components of tetracycline family, chlorotetracycline, oxytetracycline and metacycline, in the presence of hydrogen peroxide and urea peroxide. Optical parameters were obtained such as absorption, emission, lifetime and calibration curves were constructed for luminescence spectra. Experiments were carried out with both inorganic compounds and europium-tetracyclines complexes in order to verify possible interferences. Studies for glucose determination were also described using europium-tetracyclines complexes as biosensors. Results show that europium tetracyclines complexes emit a narrow band in the visible region and, in the presence of hydrogen peroxide or urea peroxide there is a greater enhancement in their luminescence and lifetime. Thus, europium-tetracyclines complexes studied can be used as biosensors for hydrogen and urea peroxides determination as a low cost and room temperature method. An indirect method for glucose determination was studied by adding glucose oxidase enzyme in europium-tetracyclines complex in the presence of glucose promoting as product hydrogen peroxide. (author)

21 CFR 529.1150 - Hydrogen peroxide.

Science.gov (United States)

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 peroxide...

Observation of atmospheric peroxides during Wangdu Campaign 2014 at a rural site in the North China Plain

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Y. Wang

2016-09-01

Full Text Available Measurements of atmospheric peroxides were made during Wangdu Campaign 2014 at Wangdu, a rural site in the North China Plain (NCP in summer 2014. The predominant peroxides were detected to be hydrogen peroxide (H2O2, methyl hydroperoxide (MHP and peroxyacetic acid (PAA. The observed H2O2 reached up to 11.3 ppbv, which was the highest value compared with previous observations in China at summer time. A box model simulation based on the Master Chemical Mechanism and constrained by the simultaneous observations of physical parameters and chemical species was performed to explore the chemical budget of atmospheric peroxides. Photochemical oxidation of alkenes was found to be the major secondary formation pathway of atmospheric peroxides, while contributions from alkanes and aromatics were of minor importance. The comparison of modeled and measured peroxide concentrations revealed an underestimation during biomass burning events and an overestimation on haze days, which were ascribed to the direct production of peroxides from biomass burning and the heterogeneous uptake of peroxides by aerosols, respectively. The strengths of the primary emissions from biomass burning were on the same order of the known secondary production rates of atmospheric peroxides during the biomass burning events. The heterogeneous process on aerosol particles was suggested to be the predominant sink for atmospheric peroxides. The atmospheric lifetime of peroxides on haze days in summer in the NCP was about 2–3 h, which is in good agreement with the laboratory studies. Further comprehensive investigations are necessary to better understand the impact of biomass burning and heterogeneous uptake on the concentration of peroxides in the atmosphere.

A photoelectron and TPEPICO investigation of the acetone radical cation.

Science.gov (United States)

Rennie, Emma E; Boulanger, Anne-Marie; Mayer, Paul M; Holland, David M P; Shaw, David A; Cooper, Louise; Shpinkova, Larisa G

2006-07-20

The valence shell photoelectron spectrum, threshold photoelectron spectrum, and threshold photoelectron photoion coincidence (TPEPICO) mass spectra of acetone have been measured using synchrotron radiation. New vibrational progressions have been observed and assigned in the X 2B2 state photoelectron bands of acetone-h6 and acetone-d6, and the influence of resonant autoionization on the threshold electron yield has been investigated. The dissociation thresholds for fragment ions up to 31 eV have been measured and compared to previous values. In addition, kinetic modeling of the threshold region for CH3* and CH4 loss leads to new values of 78 +/- 2 kJ mol(-1) and 75 +/- 2 kJ mol(-1), respectively, for the 0 K activation energies for these two processes. The result for the methyl loss channel is in reasonable agreement with, but slightly lower than, that of 83 +/- 1 kJ mol(-1) derived in a recent TPEPICO study by Fogleman et al. The modeling accounts for both low-energy dissociation channels at two different ion residence times in the mass spectrometer. Moreover, the effects of the ro-vibrational population distribution, the electron transmission efficiency, and the monochromator band-pass are included. The present activation energies yield a Delta(f)H298 for CH3CO+ of 655 +/- 3 kJ mol(-1), which is 4 kJ mol(-1) lower than that reported by Fogleman et al. The present Delta(f)H298 for CH3CO+ can be combined with the Delta(f)H298 for CH2CO (-47.5 +/- 1.6 kJ mol(-1)) and H+ (1530 kJ mol(-1)) to yield a 298 K proton affinity for ketene of 828 +/- 4 kJ mol(-1), in good agreement with the value (825 kJ mol(-1)) calculated at the G2 level of theory. The measured activation energy for CH4 loss leads to a Delta(f)H298 (CH2CO+*) of 873 +/- 3 kJ mol(-1).

Studies on acetone sensing characteristics of ZnO thin film prepared by sol–gel dip coating

Energy Technology Data Exchange (ETDEWEB)

Muthukrishnan, Karthika; Vanaraja, Manoj [School of Electrical & Electronics Engineering, SASTRA University, Thanjavur, 613401 (India); Boomadevi, Shanmugam [Department of Physics, National Institute of Technology, Tiruchirappalli, 620015 (India); Karn, Rakesh Kumar [School of Electrical & Electronics Engineering, SASTRA University, Thanjavur, 613401 (India); Singh, Vijay [Department of Chemical Engineering, Konkuk University, Seoul, 143-701 (Korea, Republic of); Singh, Pramod K. [Solar Energy Institute, Ege University, Bornova, 35100, Izmir (Turkey); Material Research Laboratory, School of Basic Sciences and Research, Sharda University, Greater Noida, 201310, U. P. (India); Pandiyan, Krishnamoorthy, E-mail: krishpandiyan@ece.sastra.edu [School of Electrical & Electronics Engineering, SASTRA University, Thanjavur, 613401 (India)

2016-07-15

Acetone sensing characteristics of Zinc Oxide thin films prepared by dip coating method are discussed in this paper. The sol for dip coating was synthesized using Zinc nitrate hexahydrate (Zn (NO{sub 3}){sub 2}. 6H{sub 2}O) and organic polymer sodium carboxy methyl cellulose (Na-CMC) as a starting material. Crystallinity and crystallite size of the prepared thin film was characterised by X-ray diffraction (XRD). Morphology was studied using field emission scanning electron microscopy (FESEM). The gas sensing characteristics was studied using chemiresistive method, by exposing the film to various concentrations of acetone at room temperature. Further, for comparative study ethanol and acetaldehyde has also been tested. Gas sensing parameters such us response, selectivity, lowest detection limit, response/recovery time of the thin film towards acetone were also reported. - Highlights: • ZnO has successfully synthesized using cheap and ease method. • Detail characterization have carried out and explained. • Sensing behaviour has been studied. • Acetone sensor has been fabricated.

A simple procedure for preparing chitin oligomers through acetone precipitation after hydrolysis in concentrated hydrochloric acid.

Science.gov (United States)

Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato

2015-11-05

Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inert Reassessment Document for Acetone - CAS No. 67-64-1

Science.gov (United States)

Acetone is a highly volatile chemical that is used as an inert ingredient, a solvent/co-solvent, in a variety of pesticide products (including outdoor yard, garden and turf products, and agricultural crop products).

Uranyl sulfate irradiations at the Van de Graaff: A means to combat uranyl peroxide precipitation

Energy Technology Data Exchange (ETDEWEB)

Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Kalensky, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin J. [Argonne National Lab. (ANL), Argonne, IL (United States); Brossard, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey D. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-05-01

As part of an effort to support SHINE Medical Technologies in developing a process to produce Mo-99 by neutron-induced fission, a series of irradiation experiments was performed with a 3 MeV Van de Graaff accelerator to generate high radiation doses in 0.5–2 mL uranyl sulfate solutions. The purpose was to determine what conditions result in uranyl peroxide precipitation and what can be done to prevent its formation. The effects of temperature, dose rate, uranium concentration, and the addition of known catalysts for the destruction of peroxide were determined.

Application of FTIR-ATR Spectroscopy to Determine the Extent of Lipid Peroxidation in Plasma during Haemodialysis

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Adam Oleszko

2015-01-01

Full Text Available During a haemodialysis (HD, because of the contact of blood with the surface of the dialyser, the immune system becomes activated and reactive oxygen species (ROS are released into plasma. Particularly exposed to the ROS are lipids and proteins contained in plasma, which undergo peroxidation. The main breakdown product of oxidized lipids is the malondialdehyde (MDA. A common method for measuring the concentration of MDA is a thiobarbituric acid reactive substances (TBARS method. Despite the formation of MDA in plasma during HD, its concentration decreases because it is removed from the blood in the dialyser. Therefore, this research proposes the Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR spectroscopy, which enables determination of primary peroxidation products. We examined the influence of the amount of hydrogen peroxide added to lipid suspension that was earlier extracted from plasma specimen on lipid peroxidation with use of TBARS and FTIR-ATR methods. Linear correlation between these methods was shown. The proposed method was effective during the evaluation of changes in the extent of lipid peroxidation in plasma during a haemodialysis in sheep. A measurement using the FTIR-ATR showed an increase in plasma lipid peroxidation after 15 and 240 minutes of treatment, while the TBARS concentration was respectively lower.

Acetone and Butanone Metabolism of the Denitrifying Bacterium “Aromatoleum aromaticum” Demonstrates Novel Biochemical Properties of an ATP-Dependent Aliphatic Ketone Carboxylase

Science.gov (United States)

Schühle, Karola

2012-01-01

The anaerobic and aerobic metabolism of acetone and butanone in the betaproteobacterium “Aromatoleum aromaticum” is initiated by their ATP-dependent carboxylation to acetoacetate and 3-oxopentanoic acid, respectively. Both reactions are catalyzed by the same enzyme, acetone carboxylase, which was purified and characterized. Acetone carboxylase is highly induced under growth on acetone or butanone and accounts for at least 5.5% of total cell protein. The enzyme consists of three subunits of 85, 75, and 20 kDa, respectively, in a (αβγ)2 composition and contains 1 Zn and 2 Fe per heterohexamer but no organic cofactors. Chromatographic analysis of the ATP hydrolysis products indicated that ATP was exclusively cleaved to AMP and 2 Pi. The stoichiometry was determined to be 2 ATP consumed per acetone carboxylated. Purified acetone carboxylase from A. aromaticum catalyzes the carboxylation of acetone and butanone as the only substrates. However, the enzyme shows induced (uncoupled) ATPase activity with many other substrates that were not carboxylated. Acetone carboxylase is a member of a protein family that also contains acetone carboxylases of various other organisms, acetophenone carboxylase of A. aromaticum, and ATP-dependent hydantoinases/oxoprolinases. While the members of this family share several characteristic features, they differ with respect to the products of ATP hydrolysis, subunit composition, and metal content. PMID:22020645

Fate of acetone in an outdoor model stream with a nitrate supplement, southern Mississippi, U.S.A.

Science.gov (United States)

Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

1991-01-01

The fate of acetone in an outdoor model stream to which nitrate was added as a nutrient supplement was determined. The stream, in southern Mississippi, U.S.A. was 234 m long. Water was supplied to the stream by an artesian well at about 1.21 s-1, resulting in a mean water velocity of about 0.5 m min-1. Acetone was injected continuously for 26 days resulting in concentrations of 20-40 mg l-1. A nitrate solution was injected for 21 days resulting in an instream concentration of about 1.7 mg l-1 at the upstream end of the stream. Rhodamine-WT dye was used to determine the travel time and dispersion characteristics of the stream, and t-butyl alcohol was used to determine the volatilization characteristics. Volatilization controlled the fate of acetone in the model stream. The lack of substantial bacterial degradation of acetone was contrary to expectations based on the results of laboratory degradation studies using model stream water enriched with nitrate. A possible explanation for the lack of significant degradation in the model stream may be the limited 6-h residence time of the acetone in the stream. ?? 1991.

Rapid and selective detection of acetone using hierarchical ZnO gas sensor for hazardous odor markers application.

Science.gov (United States)

Jia, Qianqian; Ji, Huiming; Zhang, Ying; Chen, Yalu; Sun, Xiaohong; Jin, Zhengguo

2014-07-15

Hierarchical nanostructured ZnO dandelion-like spheres were synthesized via solvothermal reaction at 200°C for 4h. The products were pure hexagonal ZnO with large exposure of (002) polar facet. Side-heating gas sensor based on hierarchical ZnO spheres was prepared to evaluate the acetone gas sensing properties. The detection limit to acetone for the ZnO sensor is 0.25ppm. The response (Ra/Rg) toward 100ppm acetone was 33 operated at 230°C and the response time was as short as 3s. The sensor exhibited remarkable acetone selectivity with negligible response toward other hazardous gases and water vapor. The high proportion of electron depletion region and oxygen vacancies contributed to high gas response sensitivity. The hollow and porous structure of dandelion-like ZnO spheres facilitated the diffusion of gas molecules, leading to a rapid response speed. The largely exposed (002) polar facets could adsorb acetone gas molecules easily and efficiently, resulting in a rapid response speed and good selectivity of hierarchical ZnO spheres gas sensor at low operating temperature. Copyright © 2014 Elsevier B.V. All rights reserved.

Metal-Exchanged β Zeolites as Catalysts for the Conversion of Acetone to Hydrocarbons

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Aurora J. Cruz-Cabeza

2012-01-01

Full Text Available Various metal-β zeolites have been synthesized under similar ion-exchange conditions. During the exchange process, the nature and acid strength of the used cations modified the composition and textural properties as well as the Brönsted and Lewis acidity of the final materials. Zeolites exchanged with divalent cations showed a clear decrease of their surface Brönsted acidity and an increase of their Lewis acidity. All materials were active as catalysts for the transformation of acetone into hydrocarbons. Although the protonic zeolite was the most active in the acetone conversion (96.8% conversion, the metal-exchanged zeolites showed varied selectivities towards different products of the reaction. In particular, we found the Cu-β to have a considerable selectivity towards the production of isobutene from acetone (over 31% yield compared to 7.5% of the protonic zeolite. We propose different reactions mechanisms in order to explain the final product distributions.

Shock-Tube Measurement of Acetone Dissociation Using Cavity-Enhanced Absorption Spectroscopy of CO.

Science.gov (United States)

Wang, Shengkai; Sun, Kai; Davidson, David F; Jeffries, Jay B; Hanson, Ronald K

2015-07-16

A direct measurement for the rate constant of the acetone dissociation reaction (CH3COCH3 = CH3CO + CH3) was conducted behind reflected shock wave, utilizing a sub-ppm sensitivity CO diagnostic achieved by cavity-enhanced absorption spectroscopy (CEAS). The current experiment eliminated the influence from secondary reactions and temperature change by investigating the clean pyrolysis of <20 ppm acetone in argon. For the first time, the acetone dissociation rate constant (k1) was directly measured over 5.5 orders of magnitude with a high degree of accuracy: k1 (1004-1494 K, 1.6 atm) = 4.39 × 10(55) T(-11.394) exp(-52 140K/T) ± 24% s(-1). This result was seen to agree with most previous studies and has bridged the gap between their temperature and pressure conditions. The current work also served as an example demonstration of the potential of using the CEAS technique in shock-tube kinetics studies.

Nitrogen-Containing Functional Groups-Facilitated Acetone Adsorption by ZIF-8-Derived Porous Carbon

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Liqing Li

2018-01-01

Full Text Available Nitrogen-doped porous carbon (ZC is prepared by modification with ammonia for increasing the specific surface area and surface polarity after carbonization of zeolite imidazole framework-8 (ZIF-8. The structure and properties of these ZCs were characterized by Transmission electron microscopy, X-ray diffraction, N2 sorption, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Through static adsorption tests of these carbons, the sample obtained at 600 °C was selected as an excellent adsorbent, which exhibited an excellent acetone capacity of 417.2 mg g−1 (25 °C with a very large surface area and high-level nitrogen doping (13.55%. The microporosity, surface area and N-containing groups of the materials, pyrrolic-N, pyridinic-N, and oxidized-N groups in particular, were found to be the determining factors for acetone adsorption by means of molecular simulation with density functional theory. These findings indicate that N-doped microporous carbon materials are potential promising adsorbents for acetone.

Problems induced by the use of acetone as a solvent to dose chlorpyrifos in a microecosystem

NARCIS (Netherlands)

Kersting, K.

1995-01-01

Recycling aquatic microecosystems consisting of three subsystems with a total volume of 7.5 L were used to study the effects of the insecticide chlorpyrifos. The poorly soluble chlorpyrifos was dosed dissolved in 0.5 ml of acetone. Acetone was found to be responsible for some of the observed

Interaction of red pepper (Capsicum annum, Tepin) polyphenols with Fe(II)-induced lipid peroxidation in brain and liver

Energy Technology Data Exchange (ETDEWEB)

Oboh, G [Biochemistry Department, Federal University of Technology, Akure, Ondo State (Nigeria); [Departamento de Quimica, Universidade Federal de Santa Maria (UFSM), Campus Universitario - Camobi, Santa Maria RS (Brazil); [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)]. E-mail: goboh2001@yahoo.com; Rocha, J B.T. [Campus Universitario - Camobi, Santa Maria RS (Brazil)

2006-03-15

Polyphenols exhibit a wide range of biological effects because of their antioxidant properties. Several types of polyphenols (phenolic acids, hydrolyzable tannins, and flavonoids) show anticarcinogenic and antimutagenic effects. Comparative studies were carried on the protective ability of free and bound polyphenol extracts of red Capsicum annuum Tepin (CAT) on brain and liver - In vitro. Free polyphenols of red Capsicum annuum Tepin (CAT) were extracted with 80% acetone, while the bound polyphenols were extracted with ethyl acetate from acid and alkaline hydrolysis of the pepper residue from free polyphenols extract. The phenol content, Fe (II) chelating ability, OH radical scavenging ability and protective ability of the extract against Fe (II)-induced lipid peroxidation in brain and liver was subsequently determined. The results of the study revealed that the free polyphenols (218.2mg/100g) content of the pepper were significantly higher than the bound polyphenols (42.5mg/100g). Furthermore, the free polyphenol extract had a significantly higher (<0.05) Fe (II) chelating ability, OH radical scavenging ability than the bound polyphenols. In addition, both extracts significantly inhibited (P<0.05) basal and 25{mu}M Fe (II)- induced lipid peroxidation in Rat's brain and liver in a dose dependent. However, the free polyphenols caused a significantly higher inhibition in the MDA (Malondialdehyde) production in the brain and liver homogenates than the bound phenols. Furthermore, the polyphenols protected the liver more than the brain. In conclusion, free polyphenols from Capsicum annuum protects both the liver and brain from Fe{sup 2+} induced lipid peroxidation, and this is probably due to the higher Fe (II) chelating ability and OH radical scavenging ability of the free polyphenols from the pepper. (author)

trans-Carbonylchloridobis[dicyclohexyl(4-isopropylphenylphosphane]rhodium(I acetone monosolvate

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Sizwe Makhoba

2011-09-01

Full Text Available The title rhodium Vaska-type complex, trans-[RhCl{P(C6H112(C6H4-4-C3H72}2(CO], crystallizes with an accompanying acetone solvent molecule. The metal atom shows a distorted square-planar coordination environment with selected important geometrical parameters of Rh—P = 2.3237 (6 and 2.3253 (6 Å, Rh—Cl = 2.3724 (6 Å, Rh—C = 1.802 (2 Å, P—Rh—P = 173.42 (2° and Cl—Rh—C = 179.13 (7°. Effective cone angles for the two P atoms are 165 and 161°, respectively. Both isopropyl groups and the acetone molecule are disordered with occupancy values of 0.523 (5:0.477 (5, 0.554 (8:0.446 (8 and 0.735 (4:0.265 (4, respectively. The crystal packing is stabilized by weak C—H...O and C—H...Cl contacts.

Measurement of formic acid, acetic acid and hydroxyacetaldehyde, hydrogen peroxide, and methyl peroxide in air by chemical ionization mass spectrometry: airborne method development

Science.gov (United States)

Treadaway, Victoria; Heikes, Brian G.; McNeill, Ashley S.; Silwal, Indira K. C.; O'Sullivan, Daniel W.

2018-04-01

A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described and optimized for quantitative gas-phase measurements of hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HCOOH), and the sum of acetic acid (CH3COOH) and hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation and methodology were designed for airborne in situ field measurements. The CIMS quantification of formic acid, acetic acid, and hydroxyacetaldehyde used I- cluster formation to produce and detect the ion clusters I-(HCOOH), I-(CH3COOH), and I-(HOCH2CHO), respectively. The CIMS also produced and detected I- clusters with hydrogen peroxide and methyl peroxide, I-(H2O2) and I-(CH3OOH), though the sensitivity was lower than with the O2- (CO2) and O2- ion clusters, respectively. For that reason, while the I- peroxide clusters are presented, the focus is on the organic acids. Acetic acid and hydroxyacetaldehyde were found to yield equivalent CIMS responses. They are exact isobaric compounds and indistinguishable in the CIMS used. Consequently, their combined signal is referred to as the acetic acid equivalent sum. Within the resolution of the quadrupole used in the CIMS (1 m/z), ethanol and 1- and 2-propanol were potential isobaric interferences to the measurement of formic acid and the acetic acid equivalent sum, respectively. The CIMS response to ethanol was 3.3 % that of formic acid and the response to either 1- or 2-propanol was 1 % of the acetic acid response; therefore, the alcohols were not considered to be significant interferences to formic acid or the acetic acid equivalent sum. The multi-reagent ion system was successfully deployed during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) in 2014. The combination of FRAPPÉ and laboratory calibrations allowed for the post-mission quantification of formic acid and the acetic acid equivalent sum observed during the Deep

Biological activities of Umbilicaria crustulosa (Ach. frey acetone extract

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Zlatanović Ivana

2017-01-01

Full Text Available This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC method. Additionally, the total phenolic compounds (TPC and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteria were determined. Acetone extract of U. crustulosa at concentration of 1 and 2 μg mL-1 decreased a frequency of micronuclei (MN by 10.8 and 16.8 %, respectively, acting more or slightly less than the synthetic protector amifostine (AMF, WR-2721, 11.4 %, at concentration of 1 μg mL-1. The tested extract did not inhibit cholinesterase activity nor did it exhibit activity toward the examined bacteria. The extract reduced the concentration of DPPH and ABTS radicals by 88.7 and 96.2 %, respectively. Values for total reducing power (TRP and cupric reducing capacity (CUPRAC were 0.6197±0.0166 μg ascorbic acid equivalents (AAE per mg of dry extract, and 19.7641±1.6546 μg trolox equivalents (TE per mg of dry extract, respectively. The total phenol content was 350.4188 ±14.587 μg gallic acid equivalents (GAE per mg of dry extract. The results of the present study showed that U. crustulosa acetone extract is a promising candidate for in vivo experiments considering its antioxidant activity and protective effect on human lymphocytes. [Projekat Ministarstva nauke Republike Srbije, br. 172047

Theoretical studies of mechanisms of cycloaddition reaction between difluoromethylene carbene and acetone

Science.gov (United States)

Lu, Xiu Hui; Yu, Hai Bin; Wu, Wei Rong; Xu, Yue Hua

Mechanisms of the cycloaddition reaction between singlet difluoromethylene carbene and acetone have been investigated with the second-order Møller-Plesset (MP2)/6-31G* method, including geometry optimization and vibrational analysis. Energies for the involved stationary points on the potential energy surface (PES) are corrected by zero-point energy (ZPE) and CCSD(T)/6-31G* single-point calculations. From the PES obtained with the CCSD(T)//MP2/6-31G* method for the cycloaddition reaction between singlet difluoromethylene carbene and acetone, it can be predicted that path B of reactions 2 and 3 should be two competitive leading channels of the cycloaddition reaction between difluoromethylene carbene and acetone. The former consists of two steps: (i) the two reactants first form a four-membered ring intermediate, INT2, which is a barrier-free exothermic reaction of 97.8 kJ/mol; (ii) the intermediate INT2 isomerizes to a four-membered product P2b via a transition state TS2b with an energy barrier of 24.9 kJ/mol, which results from the methyl group transfer. The latter proceeds in three steps: (i) the two reactants first form an intermediate, INT1c, through a barrier-free exothermic reaction of 199.4 kJ/mol; (ii) the intermediate INT1c further reacts with acetone to form a polycyclic intermediate, INT3, which is also a barrier-free exothermic reaction of 27.4 kJ/mol; and (iii) INT3 isomerizes to a polycyclic product P3 via a transition state TS3 with an energy barrier of 25.8 kJ/mol.

Hydrogen peroxide stabilization in one-dimensional flow columns

Science.gov (United States)

Schmidt, Jeremy T.; Ahmad, Mushtaque; Teel, Amy L.; Watts, Richard J.

2011-09-01

Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H 2O 2 propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25 mM citrate or phytate was applied to the columns and samples were collected at 8 ports spaced 13 cm apart. Citrate was not an effective stabilizer for hydrogen peroxide in iron-coated sand; however, phytate was highly effective, increasing hydrogen peroxide residuals two orders of magnitude over unstabilized hydrogen peroxide. Both citrate and phytate were effective stabilizers for manganese-coated sand, increasing hydrogen peroxide residuals by four-fold over unstabilized hydrogen peroxide. Phytate and citrate did not degrade and were not retarded in the sand columns; furthermore, the addition of the stabilizers increased column flow rates relative to unstabilized columns. These results demonstrate that citrate and phytate are effective stabilizers of hydrogen peroxide under the dynamic conditions of one-dimensional columns, and suggest that citrate and phytate can be added to hydrogen peroxide before injection to the subsurface as an effective means for increasing the radius of influence of CHP ISCO.

Pulse-radiolytic one-electron reduction of anthraquinone and chloro-anthraquinones in aqueous-isopropanol-acetone mixed solvent

International Nuclear Information System (INIS)

Rath, M.C.; Pal, H.; Mukherjee, T.

1996-01-01

One-electron reduction of 9,10-anthraquinone and some chloro-anthraquinones and the characteristics of the semiquinones thus formed have been investigated in aqueous-isipropanol-acetone mixed solvent using electron pulse radiolysis technique. Spectroscopic characteristics, kinetic parameters of formation and decay, and the acid/base behaviour of the semiquinones have been investigated. The one-electron reduction potential of the quinones have been measured following electron transfer equilibria with a reference redox system (methyl viologen) and the values thus obtained have been compared with those of some other anthrasemiquinone systems. An analysis of the characteristics of the semiquinones shows that α-chloro substituents adjacent to the C=O group act as electron withdrawing groups. (author)

Radial diffusive samplers for determination of 8-h concentration of BTEX, acetone, ethanol and ozone in ambient air during a sea breeze event

Science.gov (United States)

Roukos, Joelle; Locoge, Nadine; Sacco, Paolo; Plaisance, Hervé

2011-01-01

The radial diffusive sampler Radiello ® filled with Carbograph 4 was evaluated for monitoring BTEX, ethanol and acetone concentrations for 8-hour exposure time. The sampling rates were first evaluated in an exposure chamber under standard conditions. Benzene and toluene showed the highest sampling rates with satisfactory standard deviations. Ethylbenzene and xylenes showed medium sampling rates but higher standard deviations that can be attributed to a low affinity of these compounds with the adsorbent medium for short sampling time. Acetone has a fair result because of the increase of its partial pressure in the vicinity of the adsorbent surface in the course of sampling. The Carbograph 4 adsorbent does not seem to be suitable for sampling ethanol, likely because of its high volatility. The influences of three environmental factors (temperature (T), relative humidity (RH) and concentration level (C)) on the sampling rates were also evaluated, following a fractional factorial design at two factor levels (low and high). Results were only investigated on benzene, toluene and acetone. Temperature and relative humidity are found to be the most important factors leading to variability of the benzene and toluene sampling rates. The applicability of the sampler for 8-hour sampling was demonstrated by the results of a measurement campaign carried out during a sea breeze event. Mapping of benzene, toluene and acetone concentrations showed the highest concentrations in the industrial zone following the wind direction coming from the North. Nevertheless, the sea breeze tends to reduce the spread of the industrial plumes. On the contrary, the ozone map presents the lowest concentrations at the same industrial area indicating a net consumption of ozone. The highest ozone concentrations were found in the southeastern zone suggesting a local ozone formation.

Detection and sensing mechanism of acetone with modeling using Pd/TiO{sub 2}/Si structure

Energy Technology Data Exchange (ETDEWEB)

Yadava, Lallan, E-mail: nisaly06@rediffmail.com; Verma, Ritesh; Singh, Ravi S.

2012-01-31

A grided Pd/TiO{sub 2}/Si (Pdtisin) gas sensor is fabricated to detect hydrocarbons such as acetone, ethanol and trichloroethylene. The sensitivity measurements are carried out in various ambient (O{sub 2}, N{sub 2} and Ar) at room temperature which revealed that fabricated structure attains maximal response for acetone in contrast to other vapors examined. The study of ambient-effect on the device shows that it out-performs in oxygen ambient. A catalytic oxidation mechanism for detection of acetone with a model based upon Langmuir law of adsorption and Frenkel-Poole theory of electronic emission for the description of sensing behavior and vindication of experimental results have been proposed.

Graphene oxide foams and their excellent adsorption ability for acetone gas

International Nuclear Information System (INIS)

He, Yongqiang; Zhang, Nana; Wu, Fei; Xu, Fangqiang; Liu, Yu; Gao, Jianping

2013-01-01

Graphical abstract: - Highlights: • GO and RGO foams were prepared using a simple and green method, unidirectional freeze-drying. • The porous structure of the foams can be adjusted by changing GO concentrations. • GO and RGO foams show good adsorption efficiency for acetone gas. - Abstract: Graphene oxide (GO) and reduced graphene oxide (RGO) foams were prepared using a unidirectional freeze-drying method. These porous carbon materials were characterized by thermal gravimetric analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy and scanning electron microscopy. The adsorption behavior of the two kinds of foams for acetone was studied. The result showed that the saturated adsorption efficiency of the GO foams was over 100%, and was higher than that of RGO foams and other carbon materials

Determination of acetone in saliva by reversed-phase liquid chromatography with fluorescence detection and the monitoring of diabetes mellitus patients with ketoacidosis.

Science.gov (United States)

Fujii, Shinya; Maeda, Toshio; Noge, Ichiro; Kitagawa, Yutaka; Todoroki, Kenichiro; Inoue, Koichi; Min, Jun Zhe; Toyo'oka, Toshimasa

2014-03-20

In diabetes mellitus (DM) patients with ketoacidosis, ketone bodies, i.e., acetone, acetoacetic acid (AA) and β-hydroxybutyric acid (HA), are increased in the blood and urine. Acetone is also excreted by breathing due to the spontaneous decomposition of AA. Thus, the increase in acetone has been considered as one of the biomarkers for the diagnosis of DM. However, the determination of acetone in one's breath is not recommended because of the sample handling difficulty. We measured acetone in saliva by reversed-phase liquid chromatography (LC) with fluorescence (FL) detection. The proposed method was applied to the determination of acetone in the saliva of healthy volunteers and DM patients with and without ketoacidosis. 3-Pentanone (I.S.) and DBD-H in acetonitrile were added to freshly collected saliva and reacted at room temperature for 20 min in the presence of trifluoroacetic acid. After the reaction, the solution was centrifuged at 10,000 × g and 4 °C for 5 min. The supernatant was separated by reversed-phase LC and the FL detected at 550 nm (excitation at 460 nm). The concentrations of acetone in the DM patients with ketoacidosis were significantly higher than those of the normal subjects and DM patients without ketoacidosis. Furthermore, the total contents of the ketone bodies in the blood correlated with acetone in the saliva of the DM patients. The concentrations of acetone in the saliva of an emergency patient also correlated with the ketone bodies in the blood at each sampling time. The proposed method using LC-FL seems to be useful for the determination of acetone in the saliva of DM patients with ketoacidosis. The method offers a new option for the diagnosis and monitoring of DM patients with ketoacidosis. Copyright © 2014 Elsevier B.V. All rights reserved.

A Sub-ppm Acetone Gas Sensor for Diabetes Detection Using 10 nm Thick Ultrathin InN FETs

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Kao, Kun-Wei; Hsu, Ming-Che; Chang, Yuh-Hwa; Gwo, Shangjr; Yeh, J. Andrew

2012-01-01

An indium nitride (InN) gas sensor of 10 nm in thickness has achieved detection limit of 0.4 ppm acetone. The sensor has a size of 1 mm by 2.5 mm, while its sensing area is 0.25 mm by 2 mm. Detection of such a low acetone concentration in exhaled breath could enable early diagnosis of diabetes for portable physiological applications. The ultrathin InN epilayer extensively enhances sensing sensitivity due to its strong electron accumulation on roughly 5–10 nm deep layers from the surface. Platinum as catalyst can increase output current signals by 2.5-fold (94 vs. 37.5 μA) as well as reduce response time by 8.4-fold (150 vs. 1,260 s) in comparison with bare InN. More, the effect of 3% oxygen consumption due to breath inhalation and exhalation on 2.4 ppm acetone gas detection was investigated, indicating that such an acetone concentration can be analyzed in air. PMID:22969342

A Negative Correlation Between Blood Glucose and Acetone Measured in Healthy and Type 1 Diabetes Mellitus Patient Breath.

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Rydosz, Artur

2015-07-01

Exhaled acetone analysis has long been recognized as a supplementary tool for diagnosis and monitoring diabetes, especially type 1 diabetes. It is essential, therefore to determine the relationship between exhaled acetone concentration and glucose in blood. Usually, a direct linear correlation between this both compounds has been expected. However, in some cases we can observe a reverse correlation. When blood glucose was increasing, breath acetone declined. The breath analysis as a supplementary tool for diagnosing and monitoring diabetes makes sense only in case of utilization of portable analyzers. This need has created a market for gas sensors. However, commercially available acetone gas sensors are developed for measuring samples at several tens part per million. The exhaled acetone concentration was measured using commercial acetone gas sensor (TGS 822, 823 Figaro, Arlington Heights, IL, USA Inc) with micropreconcentrator in low temperature cofired ceramics. The reference analyzer-mass spectrometry (HPR-20 QIC, Hiden Analytical, Warrington, UK) was used. Twenty-two healthy volunteers with no history of any respiratory disease participated in the research, as did 31 patients diagnosed with type 1 diabetes. Respectively, 3 healthy volunteer and 5 type 1 diabetes mellitus subjects with reverse trend were selected. The linear fitting coefficient various from 0.1139 to 0.9573. Therefore, it is necessary to determine the correlation between blood glucose concentrations and under different conditions, for example, insulin levels, as well as correlate the results with clinical tests, for example, Hb1Ac. It is well known that the concentration of acetone is strongly influenced by diet, insulin treatment, and so on. Therefore, much more complex analysis with long-term measurements are required. Thus, presented results should be regarded as tentative, and validation studies with the analysis of clinical test and in a large number of patients, including control groups

Rearrangements of organic peroxides and related processes

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Ivan A. Yaremenko

2016-08-01

Full Text Available 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.

Sensitive and selective cataluminescence-based sensor system for acetone and diethyl ether determination.

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Wang, Qihui; Li, Bo; Wang, Yuhuai; Shou, Zhouxiang; Shi, Guolong

2015-05-01

A three-dimensional hierarchical CdO nanostructure with a novel bio-inspired morphology is reported. The field emission scanning electronic microscopy, transmission electron microscopy and X-ray diffractometer were employed to characterize the as-prepared samples. In gas-sensing measurements, acetone and diethyl ether were employed as target gases to investigate cataluminescence (CTL) sensing properties of the CdO nanostructure. The results show that the as-fabricated CdO nanostructure exhibited outstanding CTL properties such as stable intensity, high signal/noise values, short response and recovery time. The limit of detection of acetone and diethyl ether was ca. 6.5 ppm and 6.7 ppm, respectively, which was below the standard permitted concentrations. Additionally, a principal components analysis method was used to investigate the recognizable ability of the CTL sensor, and it was found that acetone and diethyl ether can be distinguished clearly. The performance of the bio-inspired CdO nanostructure-based sensor system suggested the promising application of the CdO nanostructure as a novel highly efficient CTL sensing material. Copyright © 2014 John Wiley & Sons, Ltd.

Protein oxidation and peroxidation

DEFF Research Database (Denmark)

Davies, Michael Jonathan

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...

Optical properties of Germanium nanoparticles synthesized by pulsed laser ablation in acetone

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Saikiran eVadavalli

2014-10-01

Full Text Available Germanium (Ge nanoparticles (NPs are synthesized by means of pulsed laser ablation of bulk germanium target immersed in acetone with ns laser pulses at different pulse energies. The fabricated NPs are characterized by employing different techniques such as UV-visible absorption spectroscopy, photoluminescence, micro-Raman spectroscopy, transmission electron microscopy (TEM and field emission scanning electron microscopy (FESEM. The mean size of the Ge NPs is found to vary from few nm to 40 nm with the increase in laser pulse energy. Shift in the position of the absorption spectra is observed and also the photoluminescence peak shift is observed due to quantum confinement effects. High resolution TEM combined with micro-Raman spectroscopy confirms the crystalline nature of the generated germanium nanoparticles. The formation of various sizes of germanium NPs at different laser pulse energies is evident from the asymmetry in the Raman spectra and the shift in its peak position towards the lower wavenumber side. The FESEM micrographs confirm the formation of germanium micro/nanostructures at the laser ablated position of the bulk germanium. In particular, the measured NP sizes from the micro-Raman phonon quantum confinement model are found in good agreement with TEM measurements of Ge NPs.

Extraction of Oxytetracycline Hydrochloride in Aqueous Two-phase System of Acetone and Ammonium Sulfate

International Nuclear Information System (INIS)

Han, J.

2013-01-01

Summary: Aqueous two-phase system (ATPS) is an efficient implement for separation of various substrates, and extracted by an aqueous two-phase system has been successful ly applied in the downstream processing of various biological compounds. In this research, the extraction of oxytetracycline hydrochloride (OTC-HCl) was carried out in an aqueous two-phase system containing acetone and ammonium sulfate solution, which partitioned the antibiotic to the upper phase. The effects of some parameters on the extraction efficiency of OTC-HCl were studied in detail, including temperature, the volume of acetone, the pH value of ammonium sulfate solution, the concentrations of (NH/sub 4/)/sub 2/ SO/sub 4/ and OTC-HCl. The results showed that the volume of acetone, the pH value of ammonium sulfate solution and the concentration of OTC-HCl in feed had significant effects on the extraction efficiency of OTC-HCl, but the effects of temperature on the extraction of OTC-HCl was not obvious. (author)

Extraction of Oxytetracycline Hydrochloride in Aqueous Two-phase System of Acetone and Ammonium Sulfate

Energy Technology Data Exchange (ETDEWEB)

Han, J. [Jiangsu Univ., Zhenjiang (China). Dept. of Food and Biological Engineering

2013-02-15

Summary: Aqueous two-phase system (ATPS) is an efficient implement for separation of various substrates, and extracted by an aqueous two-phase system has been successful ly applied in the downstream processing of various biological compounds. In this research, the extraction of oxytetracycline hydrochloride (OTC-HCl) was carried out in an aqueous two-phase system containing acetone and ammonium sulfate solution, which partitioned the antibiotic to the upper phase. The effects of some parameters on the extraction efficiency of OTC-HCl were studied in detail, including temperature, the volume of acetone, the pH value of ammonium sulfate solution, the concentrations of (NH/sub 4/)/sub 2/ SO/sub 4/ and OTC-HCl. The results showed that the volume of acetone, the pH value of ammonium sulfate solution and the concentration of OTC-HCl in feed had significant effects on the extraction efficiency of OTC-HCl, but the effects of temperature on the extraction of OTC-HCl was not obvious. (author)

Inhalation developmental toxicology studies: Teratology study of acetone in mice and rats: Final report

Energy Technology Data Exchange (ETDEWEB)

Mast, T.J.; Evanoff, J.J.; Rommereim, R.L.; Stoney, K.H.; Weigel, R.J.; Westerberg, R.B.

1988-11-01

Acetone, an aliphatic ketone, is a ubiquitous industrial solvent and chemical intermediate; consequently, the opportunity for human exposure is high. The potential for acetone to cause developmental toxicity was assessed in Sprague-Dawley rats exposed to 0, 440, 2200, or 11000 ppm, and in Swiss (CD-1) mice exposed to 0, 440, 2200, and 6600 ppm acetone vapors, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and approx.32 positively mated rats or mice. Positively mated mice were exposed on days 6-17 of gestation (dg), and rats on 6-19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. 46 refs., 6 figs., 27 tabs.

Oxidative polymerization of lignins by laccase in water-acetone mixture.

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Fiţigău, Ionița Firuța; Peter, Francisc; Boeriu, Carmen Gabriela

2013-01-01

The enzymatic oxidative polymerization of five technical lignins with different molecular properties, i.e. Soda Grass/Wheat straw Lignin, Organosolv Hardwood Lignin, Soda Wheat straw Lignin, Alkali pretreated Wheat straw Lignin, and Kraft Softwood was studied. All lignins were previously fractionated by acetone/water 50:50 (v/v) and the laccase-catalyzed polymerization of the low molecular weight fractions (Mw Reactivity of lignin substrates in laccase-catalyzed reactions was determined by monitoring the oxygen consumption. The oxidation reactions in 50% acetone in water mixture proceed with high rate for all tested lignins. Polymerization products were analyzed by size exclusion chromatography, FT-IR, and (31)P-NMR and evidence of important lignin modifications after incubation with laccase. Lignin polymers with higher molecular weight (Mw up to 17500 g/mol) were obtained. The obtained polymers have potential for applications in bioplastics, adhesives and as polymeric dispersants.

Synthesis and evaluation of inhaled [11C]butane and intravenously injected [11C]acetone as potential radiotracers for studying inhalant abuse

International Nuclear Information System (INIS)

Gerasimov, Madina R.; Ferrieri, Richard A.; Pareto, Deborah; Logan, Jean; Alexoff, David; Ding Yushin

2005-01-01

The phenomenon of inhalant abuse is a growing problem in the US and many countries around the world. Yet, relatively little is known about the pharmacokinetic properties of inhalants that underlie their abuse potential. While the synthesis of 11 C-labeled toluene, acetone and butane has been proposed in the literature, none of these compounds has been developed as radiotracers for PET studies. In the present report we extend our previous studies with [ 11 C]toluene to include [ 11 C]acetone and [ 11 C]butane with the goal of comparing the pharmacokinetic profiles of these three volatile abused substances. Both [ 11 C]toluene and [ 11 C]acetone were administered intravenously and [ 11 C]butane was administered via inhalation to anesthesized baboons. Rapid and efficient uptake of radiolabeled toluene and acetone into the brain was followed by fast clearance in the case of toluene and slower kinetics in the case of acetone. [ 11 C]Butane was detected in the blood and brain following inhalation, but the levels of radioactivity in both tissues dropped to half of the maximal values over the period of less than a minute. To our knowledge, this is the first reported study of the in vivo brain pharmacokinetics of labeled acetone and butane in nonhuman primates. These data provide insight into the pharmacokinetic features possibly associated with the abuse liability of toluene, acetone and butane

Simultaneous determination of methanol, acetaldehyde, acetone, and ethanol in human blood by gas chromatography with flame ionization detection.

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Schlatter, J; Chiadmi, F; Gandon, V; Chariot, P

2014-01-01

Methanol, acetaldehyde, acetone, and ethanol, which are commonly used as biomarkers of several diseases, in acute intoxications, and forensic settings, can be detected and quantified in biological fluids. Gas chromatography (GC)-mass spectrometry techniques are complex, require highly trained personnel and expensive materials. Gas chromatographic determinations of ethanol, methanol, and acetone have been reported in one study with suboptimal accuracy. Our objective was to improve the assessment of these compounds in human blood using GC with flame ionization detection. An amount of 50 µl of blood was diluted with 300 µl of sterile water, 40 µl of 10% sodium tungstate, and 20 µl of 1% sulphuric acid. After centrifugation, 1 µl of the supernatant was injected into the gas chromatograph. We used a dimethylpolysiloxane capillary column of 30 m × 0.25 mm × 0.25 µm. We observed linear correlations from 7.5 to 240 mg/l for methanol, acetaldehyde, and acetone and from 75 to 2400 mg/l for ethanol. Precision at concentrations 15, 60, and 120 mg/l for methanol, acetaldehyde, and acetone and 150, 600, and 1200 mg/ml for ethanol were 0.8-6.9%. Ranges of accuracy were 94.7-98.9% for methanol, 91.2-97.4% for acetaldehyde, 96.1-98.7% for acetone, and 105.5-111.6% for ethanol. Limits of detection were 0.80 mg/l for methanol, 0.61 mg/l for acetaldehyde, 0.58 mg/l for acetone, and 0.53 mg/l for ethanol. This method is suitable for routine clinical and forensic practices.

Changes of hydrogen peroxide and radical-scavenging activity of raspberry during osmotic, convective, and freeze-drying.

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Novaković, Miroslav M; Stevanović, Snežana M; Gorjanović, Stanislava Ž; Jovanovic, Predrag M; Tešević, Vele V; Janković, Miodrag A; Sužnjević, Desanka Ž

2011-05-01

This study was conducted to investigate the influence of different drying treatments on antioxidant (AO) activity and phenolic content of raspberry (Rubus idaeus), cultivar Willamette. Whole raspberry fruits were dried convectively (air-drying), osmotically, and freeze-dried. Acetone-water extracts of fresh and dried raspberries were assessed for total phenolic content by standard Folin-Ciocalteau method. Two AO assays were applied, a recently developed direct current (DC) polarographic assay based on decrease of anodic oxidation current of hydrogen peroxide and widely used radical scavenge against the 1,1-diphenyl-2-picrylhydrazyl (DPPH). Strong correlation has been obtained between both AO assays and total phenolic content. In addition, some individual phenolic compounds present in raspberry have been assessed using DPPH and DC polarographic assay. Comparison and evaluation of drying methods has been based on preservation of AO activity and total phenolic content. Obtained results confirmed superiority of freeze-drying; convective drying caused slight changes while osmotic dehydration showed a significant decrease of phenolic compounds and AO activity. © 2011 Institute of Food Technologists®

Kinetics of Platinum-Catalyzed Decomposition of Hydrogen Peroxide

Science.gov (United States)

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.

Ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate, an efficient solvent for extraction of acetone from aqueous solutions

International Nuclear Information System (INIS)

Saien, Javad; Badieh, Marjan Mohammadi Sarab; Norouzi, Mahdi; Salehzadeh, Sadegh

2015-01-01

Highlights: • The use of HMIMPF_6 as a green ionic was feasible in the extraction of acetone from water. • The binodal curves were determined by cloud point measurement method. • High level separation factor of acetone between the ionic liquid and water were achieved. • The thermodynamic properties of HMIMPF_6 were obtained by the Density Functional Theory calculations. • The NRTL and UNIQUAC models were applied satisfactorily to correlate the equilibrium data. - Abstract: (Liquid + liquid) equilibrium (LLE) of the chemical system of {water + acetone + 1-Hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF_6) ionic liquid} was studied at different temperatures of (293.2, 298.2 and 303.2) K and under atmospheric pressure of 81.5 kPa. The results show that HMIMPF_6 provides the acetone distribution coefficient and separation factor values within (0.8813 to 1.2351) and (3.0 to 54.4), respectively; indicating the high capability of the ionic liquid for extraction of acetone from aqueous solutions. In most cases, acetone solubility in the ionic liquid is higher than in water, especially at higher solute concentrations. Meanwhile, higher separation factor is relevant to the lower temperature due to lower (water + ionic liquid) miscibility. The consistency of tie line data, at each temperature, was examined with Othmer–Tobias correlation. The values were nicely reproduced with the well-known NRTL and UNIQUAC models. Accordingly, the required thermodynamic properties of HMIMPF_6 were obtained by the Density Functional Theory (DFT) calculations, carried out at the M06/6-311++G"∗"∗ level of theory. The root mean square deviations (RMSD) between experimental and model concentration values were 0.0192 and 0.0255, respectively; indicating close agreement of the both models.

Hydrogen Peroxide Probes Directed to Different Cellular Compartments

Science.gov (United States)

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

Hydrogen peroxide probes directed to different cellular compartments.

Directory of Open Access Journals (Sweden)

Mikalai Malinouski

2011-01-01

Full Text Available 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.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.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.

Effect of hydrodynamic cavitation on the rate of OH-radical formation in the presence of hydrogen peroxide

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Aseev, D. G.; Batoeva, A. A.

2014-01-01

It is shown experimentally that hydrogen peroxide is the source of OH-radicals at low-pressure hydrodynamic cavitation. Major preconditions for the intensification of oxidative destruction processes in organic pollutants with an added cavitation stimulus are determined.

Acetonic and Methanolic Extracts of Heterotheca inuloides, and Quercetin, Decrease CCl4-Oxidative Stress in Several Rat Tissues

Science.gov (United States)

Coballase-Urrutia, Elvia; Pedraza-Chaverri, José; Cárdenas-Rodríguez, Noemí; Huerta-Gertrudis, Bernardino; García-Cruz, Mercedes Edna; Montesinos-Correa, Hortencia; Sánchez-González, Dolores Javier; Camacho-Carranza, Rafael; Espinosa-Aguirre, Jesús Javier

2013-01-01

The present study was designed to test the hypothesis that the acetonic and methanolic extracts of H. inuloides prevent carbon tetrachloride-(CCl4) induced oxidative stress in vital tissues. Pretreatment with both H. inuloides extracts or quercetin attenuated the increase in serum activity of alkaline phosphatase (ALP), total bilirubin (BB), creatinine (CRE), and creatine kinase (CK), and impeded the decrease of γ-globulin (γ-GLOB) and albumin (ALB) observed in CCl4-induced tissue injury. The protective effect was confirmed by histological analysis with hematoxylin-eosin and periodic acid/Schiff's reagent. Level of lipid peroxidation was higher in the organs of rats exposed to CCl4 than in those of the animals treated with Heterohteca extracts or quercetin, and these showed levels similar to the untreated group. Pretreatment of animals with either of the extracts or quercetin also prevented the increase of 4-hydroxynonenal and 3-nitrotyrosine. Pretreatment with the plant extracts or quercetin attenuated CCl4 toxic effects on the activity of several antioxidant enzymes. The present results strongly suggest that the chemopreventive effect of the extracts used and quercetin, against CCl4 toxicity, is associated with their antioxidant properties and corroborated previous results obtained in liver tissue. PMID:23365610

Electrolytically exfoliated graphene-loaded flame-made Ni-doped SnO2 composite film for acetone sensing.

Science.gov (United States)

Singkammo, Suparat; Wisitsoraat, Anurat; Sriprachuabwong, Chakrit; Tuantranont, Adisorn; Phanichphant, Sukon; Liewhiran, Chaikarn

2015-02-11

In this work, flame-spray-made SnO2 nanoparticles are systematically studied by doping with 0.1-2 wt % nickel (Ni) and loading with 0.1-5 wt % electrolytically exfoliated graphene for acetone-sensing applications. The sensing films (∼12-18 μm in thickness) were prepared by a spin-coating technique on Au/Al2O3 substrates and evaluated for acetone-sensing performances at operating temperatures ranging from 150 to 350 °C in dry air. Characterizations by X-ray diffraction, transmission/scanning electron microscopy, Brunauer-Emmett-Teller analysis, X-ray photoelectron spectroscopy and Raman spectroscopy demonstrated that Ni-doped SnO2 nanostructures had a spheriodal morphology with a polycrystalline tetragonal SnO2 phase, and Ni was confirmed to form a solid solution with SnO2 lattice while graphene in the sensing film after annealing and testing still retained its high-quality nonoxidized form. Gas-sensing results showed that SnO2 sensing film with 0.1 wt % Ni-doping concentration exhibited an optimal response of 54.2 and a short response time of ∼13 s toward 200 ppm acetone at an optimal operating temperature of 350 °C. The additional loading of graphene at 5 wt % into 0.1 wt % Ni-doped SnO2 led to a drastic response enhancement to 169.7 with a very short response time of ∼5.4 s at 200 ppm acetone and 350 °C. The superior gas sensing performances of Ni-doped SnO2 nanoparticles loaded with graphene may be attributed to the large specific surface area of the composite structure, specifically the high interaction rate between acetone vapor and graphene-Ni-doped SnO2 nanoparticles interfaces and high electronic conductivity of graphene. Therefore, the 5 wt % graphene loaded 0.1 wt % Ni-doped SnO2 sensor is a promising candidate for fast, sensitive and selective detection of acetone.

Understanding the mechanism of DNA deactivation in ion therapy of cancer cells: hydrogen peroxide action*

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Piatnytskyi, Dmytro V.; Zdorevskyi, Oleksiy O.; Perepelytsya, Sergiy M.; Volkov, Sergey N.

2015-11-01

Changes in the medium of biological cells under ion beam irradiation has been considered as a possible cause of cell function disruption in the living body. The interaction of hydrogen peroxide, a long-lived molecular product of water radiolysis, with active sites of DNA macromolecule was studied, and the formation of stable DNA-peroxide complexes was considered. The phosphate groups of the macromolecule backbone were picked out among the atomic groups of DNA double helix as a probable target for interaction with hydrogen peroxide molecules. Complexes consisting of combinations including: the DNA phosphate group, H2O2 and H2O molecules, and Na+ counterion, were considered. The counterions have been taken into consideration insofar as under the natural conditions they neutralise DNA sugar-phosphate backbone. The energy of the complexes have been determined by considering the electrostatic and the Van der Waals interactions within the framework of atom-atom potential functions. As a result, the stability of various configurations of molecular complexes was estimated. It was shown that DNA phosphate groups and counterions can form stable complexes with hydrogen peroxide molecules, which are as stable as the complexes with water molecules. It has been demonstrated that the formation of stable complexes of H2O2-Na+-PO4- may be detected experimentally by observing specific vibrations in the low-frequency Raman spectra. The interaction of H2O2 molecule with phosphate group of the double helix backbone can disrupt DNA biological function and induce the deactivation of the cell genetic apparatus. Thus, the production of hydrogen peroxide molecules in the nucleus of living cells can be considered as an additional mechanism by which high-energy ion beams destroy tumour cells during ion beam therapy. Contribution to the Topical Issue "COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy", edited by Andrey Solov'yov, Nigel Mason, Gustavo García, Eugene

Determination of the two methyl group orientations at vapor/acetone interface with polarization null angle method in SFG vibrational spectroscopy

Science.gov (United States)

Chen, Hua; Gan, Wei; Wu, Bao-hua; Wu, Dan; Zhang, Zhen; Wang, Hong-fei

2005-06-01

We report a direct measurement of the orientation of the two CH 3 groups of acetone molecule at the vapor/acetone interface. The interfacial acetone molecule is found well-ordered, with one methyl group points away around 14.4° ± 1.9° and another into the bulk liquid around 102.8° ± 1.9° from the interface normal, and thus the C dbnd O group points into the bulk around 135.8° ± 1.9°. These results directly confirmed the highly ordered and even crystal like interfacial structure of the vapor/acetone interface from previous MD simulation. The general formulation and accurate determination of the orientational parameter D can be used to treat interfaces with complex molecular orientations.

Models construction for acetone-butanol-ethanol fermentations with acetate/butyrate consecutively feeding by graph theory.

Science.gov (United States)

Li, Zhigang; Shi, Zhongping; Li, Xin

2014-05-01

Several fermentations with consecutively feeding of acetate/butyrate were conducted in a 7 L fermentor and the results indicated that exogenous acetate/butyrate enhanced solvents productivities by 47.1% and 39.2% respectively, and changed butyrate/acetate ratios greatly. Then extracellular butyrate/acetate ratios were utilized for calculation of acids rates and the results revealed that acetate and butyrate formation pathways were almost blocked by corresponding acids feeding. In addition, models for acetate/butyrate feeding fermentations were constructed by graph theory based on calculation results and relevant reports. Solvents concentrations and butanol/acetone ratios of these fermentations were also calculated and the results of models calculation matched fermentation data accurately which demonstrated that models were constructed in a reasonable way. Copyright © 2014 Elsevier Ltd. All rights reserved.

Photochemistry of peroxoborates: borate inhibition of the photodecomposition of hydrogen peroxide.

Science.gov (United States)

Rey, Sébastien; Davies, D Martin

2006-12-13

The UV absorbance and photochemical decomposition kinetics of hydrogen peroxide in borate/boric acid buffers were investigated as a function of pH, total peroxide concentration, and total boron concentration. At higher pH borate/boric acid inhibits the photodecomposition of hydrogen peroxide (molar absorptivity and quantum yield of H(2)O(2) and HO(2) (-), (19.0+/-0.3) M(-1) cm(-1) and 1, and (237+/-7) M(-1) cm(-1) and 0.8+/-0.1, respectively). The results are consistent with the equilibrium formation of the anions monoperoxoborate, K(BOOH)=[H(+)][HOOB(OH)(3) (-)]/([B(OH)(3)][H(2)O(2)]), 2.0 x 10(-8), R. Pizer, C. Tihal, Inorg. Chem. 1987, 26, 3639-3642, and monoperoxodiborate, K(BOOB)=[BOOB(2-)]/([B(OH)(4) (-)][HOOB(OH)(3) (-)]), 1.0+/-0.3 or 4.3+/-0.9, depending upon the conditions, with molar absorptivity, (19+/-1) M(-1) cm(-1) and (86+/-15) M(-1) cm(-1), respectively, and respective quantum yields, 1.1+/-0.1 and 0.04+/-0.04. The low quantum yield of monoperoxodiborate is discussed in terms of the slower diffusion apart of incipient (.)OB(OH)(3) (-) radicals than may be possible for (.)OH radicals, or a possible oxygen-bridged cyclic structure of the monoperoxodiborate.

Hydrogen peroxide treatment of TCE contaminated soil

International Nuclear Information System (INIS)

Hurst, D.H.; Robinson, K.G.; Siegrist, R.L.

1993-01-01

Solvent contaminated soils are ubiquitous in the industrial world and represent a significant environmental hazard due to their persistence and potentially negative impacts on human health and the environment. Environmental regulations favor treatment of soils with options which reduce the volume and toxicity of contaminants in place. One such treatment option is the in-situ application of hydrogen peroxide to soils contaminated with chlorinated solvents such as trichloroethylene (TCE). This study investigated hydrogen peroxide mass loading rates on removal of TCE from soils of varying organic matter content. Batch experiments conducted on contaminated loam samples using GC headspace analysis showed up to 80% TCE removal upon peroxide treatment. Column experiments conducted on sandy loam soils with high organic matter content showed only 25% TCE removal, even at hydrogen peroxide additions of 25 g peroxide per kg soil

One electron reduction of 1,2 dihydroxy 9,10 anthraquinone and its transition metal complexes in aqueous-isopropanol-acetone mixed solvent: a steady state-state and pulse radiolysis study

International Nuclear Information System (INIS)

Das, Saurabh; Mandal, Parikshit C.; Rath, Madhab C.; Mukherjee, Tulsi

1998-01-01

One electron reduction of 1,2 dihydroxy 9,10 anthraquinone and its Cu(II) and Ni(II) and Fe(III) complexes have been studied in aqueous-isopropanol-acetone solvent. Results indicate that the reducing ketyl radical generated reacts with the ligand forming semiquinones which undergoes a disproportionation reaction. Formation and decay rates of semiquinones was calculated using pulse radiolysis. (author)

DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

Science.gov (United States)

Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

2016-07-01

The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

Histochemical detection of GM1 ganglioside using cholera toxin-B subunit. Evaluation of critical factors optimal for in situ detection with special emphasis to acetone pre-extraction

Science.gov (United States)

Petr, T.; Šmíd, V.; Šmídová, J.; Hůlková, H.; Jirkovská, M.; Elleder, M.; Muchová, L.; Vítek, L.; Šmíd, F.

2010-01-01

A comparison of histochemical detection of GM1 ganglioside in cryostat sections using cholera toxin B-subunit after fixation with 4% formaldehyde and dry acetone gave tissue-dependent results. In the liver no pre-treatment showed detectable differences related to GM1 reaction products, while studies in the brain showed the superiority of acetone pre-extraction (followed by formaldehyde), which yielded sharper images compared with the diffuse, blurred staining pattern associated with formaldehyde. Therefore, the aim of our study was to define the optimal conditions for the GM1 detection using cholera toxin B-subunit. Ganglioside extractability with acetone, the ever neglected topic, was tested comparing anhydrous acetone with acetone containing admixture of water. TLC analysis of acetone extractable GM1 ganglioside from liver sections did not exceed 2% of the total GM1 ganglioside content using anhydrous acetone at −20°C, and 4% at room temperature. The loss increased to 30.5% using 9:1 acetone/water. Similarly, photometric analysis of lipid sialic acid, extracted from dried liver homogenates with anhydrous acetone, showed the loss of gangliosides into acetone 3.0±0.3% only. The loss from dried brain homogenate was 9.5±1.1%. Thus, anhydrous conditions (dry tissue samples and anhydrous acetone) are crucial factors for optimal in situ ganglioside detection using acetone pre-treatment. This ensures effective physical fixation, especially in tissues rich in polar lipids (precipitation, prevention of in situ diffusion), and removal of cholesterol, which can act as a hydrophobic blocking barrier. PMID:20558344

Histochemical detection of GM1 ganglioside using cholera toxin-B subunit. Evaluation of critical factors optimal for in situ detection with special emphasis to acetone pre-extraction

Directory of Open Access Journals (Sweden)

T. Petr

2010-05-01

Full Text Available A comparison of histochemical detection of GM1 ganglioside in cryostat sections using cholera toxin B-subunit after fixation with 4% formaldehyde and dry acetone gave tissue-dependent results. In the liver no pre-treatment showed detectable differences related to GM1 reaction products, while studies in the brain showed the superiority of acetone pre-extraction (followed by formaldehyde, which yielded sharper images compared with the diffuse, blurred staining pattern associated with formaldehyde. Therefore, the aim of our study was to define the optimal conditions for the GM1 detection using cholera toxin B-subunit. Ganglioside extractability with acetone, the ever neglected topic, was tested comparing anhydrous acetone with acetone containing admixture of water. TLC analysis of acetone extractable GM1 ganglioside from liver sections did not exceed 2% of the total GM1 ganglioside content using anhydrous acetone at -20°C, and 4% at room temperature. The loss increased to 30.5% using 9:1 acetone/water. Similarly, photometric analysis of lipid sialic acid, extracted from dried liver homogenates with anhydrous acetone, showed the loss of gangliosides into acetone 3.0±0.3% only. The loss from dried brain homogenate was 9.5±1.1%. Thus, anhydrous conditions (dry tissue samples and anhydrous acetone are crucial factors for optimal in situ ganglioside detection using acetone pre-treatment. This ensures effective physical fixation, especially in tissues rich in polar lipids (precipitation, prevention of in situ diffusion, and removal of cholesterol, which can act as a hydrophobic blocking barrier.

Photocatalytic degradation of acetone and butane on mesoporous titania layers

Czech Academy of Sciences Publication Activity Database

Štengl, Václav; Houšková, Vendula; Bakardjieva, Snejana; Murafa, Nataliya

2010-01-01

Roč. 34, č. 9 (2010), s. 1999-2005 ISSN 1144-0546 R&D Projects: GA ČR GA203/08/0334 Institutional research plan: CEZ:AV0Z40320502 Keywords : thin-films * gaseous acetone * oxidation * TIO2 Subject RIV: CA - Inorganic Chemistry Impact factor: 2.631, year: 2010

Breath acetone concentration; biological variability and the influence of diet

Czech Academy of Sciences Publication Activity Database

Španěl, Patrik; Dryahina, Kseniya; Rejšková, A.; Chippendale, T. W. E.; Smith, D.

2011-01-01

Roč. 32, č. 8 (2011), N23-N31 ISSN 0967-3334 R&D Projects: GA ČR GP203/09/P172 Institutional research plan: CEZ:AV0Z40400503 Keywords : acetone * breath * ketogenic diet Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.677, year: 2011

Hydrous Ferric Oxides in Sediment Catalyze Formation of Reactive Oxygen Species during Sulfide Oxidation

Directory of Open Access Journals (Sweden)

Sarah A. Murphy

2016-11-01

Full Text Available Abstract: This article describes the formation of reactive oxygen species as a result of the oxidation of dissolved sulfide by Fe(III-containing sediments suspended in oxygenated seawater over the pH range 7.00 and 8.25. Sediment samples were obtained from across the coastal littoral zone in South Carolina, US, at locations from the beach edge to the forested edge of a Spartina dominated estuarine salt marsh and suspended in aerated seawater. Reactive oxygen species (superoxide and hydrogen peroxide production was initiated in sediment suspensions by the addition of sodium bisulfide. The subsequent loss of HS-, formation of Fe(II (as indicated by Ferrozine, and superoxide and hydrogen peroxide were monitored over time. The concentration of superoxide rose from the baseline and then persisted at an apparent steady state concentration of approximately 500 nanomolar at pH 8.25 and 200 nanomolar at pH 7.00 respectively until >97% hydrogen sulfide was consumed. Measured superoxide was used to predict hydrogen peroxide yield based on superoxide dismutation. Dismutation alone quantitatively predicted hydrogen peroxide formation at pH 8.25 but over predicted hydrogen peroxide formation at pH 7 by a factor of approximately 102. Experiments conducted with episodic spikes of added hydrogen peroxide indicated rapid hydrogen peroxide consumption could account for its apparent low instantaneous yield, presumably the result of its reaction with Fe(II species, polysulfides or bisulfite. All sediment samples were characterized for total Fe, Cu, Mn, Ni, Co and hydrous ferric oxide by acid extraction followed by mass spectrometric or spectroscopic characterization. Sediments with the highest loadings of hydrous ferric oxide were the only sediments that produced significant dissolved Fe(II species or ROS as a result of sulfide exposure.

Kinetic Model of Resin－Catalyzed Decomposition of Acetone Cyanohydrin in Organic Solvent

Institute of Scientific and Technical Information of China (English)

章亭洲; 杨立荣; 朱自强; 吴坚平

2003-01-01

Decomposition of acetone cyanohydrin is the first-step reaction for preparing (S)-α-cyano-3-phenoxybenzyl alcohol (CPBA) by the one-pot method in organic media. Considering the compatibility of biocatalysts with chemical catalysts and the successive operation in the bioreactor, anion exchange resin (D301) was used as catalyst for this reaction. External diffusion limitation was excluded by raising rotational speed to higher than 190r·min-1 in both solvents. Internal diffusion limitation was verified to be insignificant in this reaction system. The effect of acetone cyanohydrin concentration on the reaction was also investigated. An intrinsic kinetic model was proposed when the mass transfer limitation was excluded, and the average deviation of the model is 10.5%.

Toxicity study of di(2-ethylhexyl)phthalate (DEHP) in combination with acetone in rats

DEFF Research Database (Denmark)

Dalgaard, M.; Østergaard, G.; Lam, Henrik Rye

2000-01-01

In two separate studies with exposure duration 9 weeks or 4 weeks, male Wistar rats were dosed with di(2-ethylhexyl)phthalate (DEHP) by gavage and exposed to drinking water with or without acetone (0.5% wt/v in the 9-week study, 1.0% wt/v in the 4-week study). In the 9-week study the doses of DEHP...... were 0, 125, 250, 500 or 1000 mg/kg b.wt. In the 4-week study the doses of DEHP were increased to 1000, 5000 and 10,000 mg/kg b.wt. In the 9-week study, the relative liver weight was increased in the rats exposed to 500 and 1000 mg/kg b.wt. No interaction of DEHP and acetone was observed in any...... of the measured parameters. In the 4-week study DEHP, at the highest dose level, resulted in severe general toxicity. The group exposed to DEHP in combination with acetone was more affected. Male fertility was decreased. Body weight was decreased, and the relative weight of the liver, kidney, heart, brain...

Effect of antioxidants and silicates on peroxides in povidone.

Science.gov (United States)

Narang, Ajit S; Rao, Venkatramana M; Desai, Divyakant S

2012-01-01

Reactive peroxides in povidone often lead to degradation of oxidation-labile drugs. To reduce peroxide concentration in povidone, the roles of storage conditions, antioxidants, and silicates were investigated. Povidone alone and its physical mixtures with ascorbic acid, propyl gallate, sodium sulfite, butylated hydroxyanisole (BHA), or butylated hydroxytoluene (BHT) were stored at 25 °C and 40 °C, at 11%, 32%, and 50% relative humidity. In addition, povidone solution in methanol was equilibrated with silicates (silica gel and molecular sieves), followed by solvent evaporation to recover povidone powder. Peroxide concentrations in povidone were measured. The concentration of peroxides in povidone increased under very-low-humidity storage conditions. Among the antioxidants, ascorbic acid, propyl gallate, and sodium sulfite reduced the peroxide concentration in povidone, whereas BHA and BHT did not. Water solubility appeared to determine the effectiveness of antioxidants. Also, some silicates significantly reduced peroxide concentration in povidone without affecting its functionality as a tablet binder. Porosity of silicates was critical to their ability to reduce the peroxide concentration in povidone. A combination of these approaches can reduce the initial peroxide concentration in povidone and minimize peroxide growth under routine storage conditions. Copyright © 2011 Wiley-Liss, Inc.

α-chymotrypsin in water-acetone and water-dimethyl sulfoxide mixtures: Effect of preferential solvation and hydration.

Science.gov (United States)

Sirotkin, Vladimir A; Kuchierskaya, Alexandra A

2017-10-01

We investigated water/organic solvent sorption and residual enzyme activity to simultaneously monitor preferential solvation/hydration of protein macromolecules in the entire range of water content at 25°C. We applied this approach to estimate protein destabilization/stabilization due to the preferential interactions of bovine pancreatic α-chymotrypsin with water-acetone (moderate-strength H-bond acceptor) and water-DMSO (strong H-bond acceptor) mixtures. There are three concentration regimes for the dried α-chymotrypsin. α-Chymotrypsin is preferentially hydrated at high water content. The residual enzyme activity values are close to 100%. At intermediate water content, the dehydrated α-chymotrypsin has a higher affinity for acetone/DMSO than for water. Residual enzyme activity is minimal in this concentration range. The acetone/DMSO molecules are preferentially excluded from the protein surface at the lowest water content, resulting in preferential hydration. The residual catalytic activity in the water-poor acetone is ∼80%, compared with that observed after incubation in pure water. This effect is very small for the water-poor DMSO. Two different schemes are operative for the hydrated enzyme. At high and intermediate water content, α-chymotrypsin exhibits preferential hydration. However, at intermediate water content, in contrast to the dried enzyme, the initially hydrated α-chymotrypsin possesses increased preferential hydration parameters. At low water content, no residual enzyme activity was observed. Preferential binding of DMSO/acetone to α-chymotrypsin was detected. Our data clearly demonstrate that the hydrogen bond accepting ability of organic solvents and the protein hydration level constitute key factors in determining the stability of protein-water-organic solvent systems. © 2017 Wiley Periodicals, Inc.

Multi-shelled ZnCo2O4 yolk-shell spheres for high-performance acetone gas sensor

Science.gov (United States)

Xiong, Ya; Zhu, Zongye; Ding, Degong; Lu, Wenbo; Xue, Qingzhong

2018-06-01

In the present study, multi-shelled ZnCo2O4 yolk-shell spheres have been successfully prepared by using carbonaceous microspheres as templates. It is found that the multi-shelled ZnCo2O4 yolk-shell spheres based sensor shows optimal sensing performances (response value of 38.2, response/recovery time of 19 s/71 s) toward 500 ppm acetone at 200 °C. In addition, this sensor exhibits a low detection limit of 0.5 ppm acetone (response value of 1.36) and a good selectivity toward hydrogen, methane, ethanol, ammonia and carbon dioxide. Furthermore, it is demonstrated that acetone gas response of multi-shelled ZnCo2O4 yolk-shell spheres is significantly better than that of ZnCo2O4 nanotubes and ZnCo2O4 nanosheets. High acetone response of the multi-shelled ZnCo2O4 yolk-shell spheres is attributed to the enhanced gas accessibility of the multi-shell morphology caused by the small crystalline size and high specific surface area while the short response/recovery time is mainly related to the rapid gas diffusion determined by the highly porous structure. Our work puts forward an exciting opportunity in designing various yolk-shelled structures for multipurpose applications.

Thermodynamics and economic feasibility of acetone production from syngas using the thermophilic production host Moorella thermoacetica

DEFF Research Database (Denmark)

Redl, Stephanie Maria Anna; Sukumara, Sumesh; Ploeger, Tom

2017-01-01

-gas via condensation. Results: In this study we analyzed the production of acetone from syngas with the hypothetical production host derived from Moorella thermoacetica in a bubble column reactor at 60 degrees C with respect to thermodynamic and economic feasibility. We determined the cost of syngas...... production from basic oxygen furnace (BOF) process gas, from natural gas, and from corn stover and identified BOF gas as an economically interesting source for syngas. Taking gasliquid mass transfer limitations into account, we applied a thermodynamics approach to derive the CO to acetone conversion rate...... under the process conditions. We estimated variable costs of production of 389 $/t acetone for a representative production scenario from BOF gas with costs for syngas as the main contributor. In comparison, the variable costs of production from natural gas-and corn stover-derived syngas were determined...

Determination of hydrogen peroxide in water by chemiluminescence detection, (1). Flow injection type hydrogen peroxide detection system

International Nuclear Information System (INIS)

Yamashiro, Naoya; Uchida, Shunsuke; Satoh, Yoshiyuki; Morishima, Yusuke; Yokoyama, Hiroaki; Satoh, Tomonori; Sugama, Junichi; Yamada, Rie

2004-01-01

A flow injection type hydrogen peroxide detection system with a sub-ppb detection limit has been developed to determine hydrogen peroxide concentration in water sampled from a high temperature, high pressure hydrogen peroxide water loop. The hydrogen peroxide detector is based on luminol chemiluminescence spectroscopy. A small amount of sample water (20 μl) is mixed with a reagent mixture, an aqueous solution of luminol and Co 2+ catalyst, in a mixing cell which is installed just upstream from the detection cell. The optimum values for pH and the concentrations of luminol and Co 2+ ion have been determined to ensure a lower detectable limit and a higher reproducibility. The photocurrent detected by the detection system is expressed by a linear function of the hydrogen peroxide concentration in the region of lower concentration ([H 2 O 2 ] 2 O 2 ] in the region of higher concentration ([H 2 O 2 ] > 10 ppb). The luminous intensity of luminol chemiluminescence is the highest when pH of the reagent mixture is 11.0. Optimization of the major parameters gives the lowest detectable limit of 0.3 ppb. (author)

Analysis of O-Glycopeptides by Acetone Enrichment and Capillary Electrophoresis-Mass Spectrometry.

Science.gov (United States)

Mancera-Arteu, Montserrat; Giménez, Estela; Benavente, Fernando; Barbosa, José; Sanz-Nebot, Victòria

2017-11-03

Acetone precipitation was evaluated as a rapid, simple, low-cost, and efficient method for the selective purification of O-glycopeptides from enzymatic digests of glycoproteins. Ovalbumin (OVA), human and bovine α 1 -acid glycoprotein (hAGP and bAGP), human apolipoprotein C-III (APO-C3), and recombinant human erythropoietin (rhEPO) were used to obtain enzymatic digests with a broad and varied set of peptides, N-glycopeptides, and O-glycopeptides. After digestion and before capillary electrophoresis mass spectrometry (CE-MS) analysis, the amount of ice-cold acetone added to the digests was optimized to maximize recoveries of O-glycopeptides. Furthermore, the different behavior of peptides, N- and O-glycopeptides was explained by studying with multivariate data analysis methods the influence of several physicochemical parameters and properties related to their composition and structure. Principal component analysis (PCA) and, afterward, partial least-squares discriminant analysis (PLS-DA) were used to identify the most significant variables and their importance to differentiate between peptides, N-glycopeptides and O-glycopeptides, or within these classes. This information was useful to understand precipitation of these compounds after addition of acetone and for the selection of the optimal conditions for purification of specific O-glycopeptide biomarkers. Special attention was paid to O 126 -glycopeptide glycoforms of rhEPO because of their applicability in biopharmaceutical quality control and doping analysis.

Peculiar behavior of MWW materials in aldol condensation of furfural and acetone.

Science.gov (United States)

Kikhtyanin, Oleg; Chlubná, Pavla; Jindrová, Tereza; Kubička, David

2014-07-21

MWW family of different structural types (MCM-22, MCM-49, MCM-56 and MCM-36) was used as catalysts for aldol condensation of furfural and acetone studied in a batch reactor at 100 °C, autogenous pressure and a reaction time of 0-4 h. To establish a relation between physico-chemical and catalytic properties of microporous materials, the samples were characterized by XRD, SEM, N2 adsorption, FTIR and TGA. It was found that the acidic solids possessed appreciable activity in the reaction and resulted in the formation of products of aldehyde-ketone interaction. Surprisingly, MCM-22 and MCM-49, i.e. three-dimensional materials containing internal supercages, exhibited higher activity than two MCM-36 catalysts with two-dimensional character having larger accessible external surface area due to expansion of the interlayer space by swelling and pillaring treatments. Moreover, all MWW family catalysts gave higher conversion than the large-pore zeolite BEA. Nevertheless, furfural conversion decreased rapidly for all the studied materials due to coke formation. Unexpectedly, the deactivation was found to be more severe for MCM-36 catalysts than for MCM-22 and MCM-49, which was attributed to the reaction taking place also in supercages that are protected by 10-ring channels from severe coking. In contrast the cups located on the external surface were coked rapidly.

Butanol-acetone fermentation. Bibliographic synthesis and current trends

Energy Technology Data Exchange (ETDEWEB)

Marchal, R. (Institut Francais du Petrole, Rueil-Malmaison (France))

This article gives a synthesis of what is known about butyl-acetone fermentation from both the microbiological and technological standpoints. Different aspects of the metabolism of the microorganism used and of how it is regulated are considered. The performances of fermentation on traditional substrates (cornmeal or molasses) are compared with those recently obtained using Jerusalem artichokes at Institut Francais du Petrole as part of a new project on this fermentation for the purpose of producing substitute fuel.

Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

Science.gov (United States)

Locke, Bruce R.; Shih, Kai-Yuan

2011-06-01

This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 × 10-2 to 80 g kWh-1. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

Review of the methods to form hydrogen peroxide in electrical discharge plasma with liquid water

Energy Technology Data Exchange (ETDEWEB)

Locke, Bruce R; Shih, Kai-Yuan [Department of Chemical and Biomedical Engineering, Florida State University, Tallahassee, FL 32310 (United States)

2011-06-15

This paper presents a review of the literature dealing with the formation of hydrogen peroxide from plasma processes. Energy yields for hydrogen peroxide generation by plasma from water span approximately three orders of magnitude from 4 x 10{sup -2} to 80 g kWh{sup -1}. A wide range of plasma processes from rf to pulsed, ac, and dc discharges directly in the liquid phase have similar energy yields and may thus be limited by radical quenching processes at the plasma-liquid interface. Reactor modification using discharges in bubbles and discharges over the liquid phase can provide modest improvements in energy yield over direct discharge in the liquid, but the interpretation is complicated by additional chemical reactions of gas phase components such as ozone and nitrogen oxides. The highest efficiency plasma process utilizes liquid water droplets that may enhance efficiency by sequestering hydrogen peroxide in the liquid and by suppressing decomposition reactions by radicals from the gas and at the interface. Kinetic simulations of water vapor reported in the literature suggest that plasma generation of hydrogen peroxide should approach 45% of the thermodynamics limit, and this fact coupled with experimental studies demonstrating improvements with the presence of the condensed liquid phase suggest that further improvements in energy yield may be possible. Plasma generation of hydrogen peroxide directly from water compares favorably with a number of other methods including electron beam, ultrasound, electrochemical and photochemical methods, and other chemical processes.

Temperature Programmed Desorption of Quench-condensed Krypton and Acetone in Air; Selective Concentration of Ultra-trace Gas Components.

Science.gov (United States)

Suzuki, Taku T; Sakaguchi, Isao

2016-01-01

Selective concentration of ultra-trace components in air-like gases has an important application in analyzing volatile organic compounds in the gas. In the present study, we examined quench-condensation of the sample gas on a ZnO substrate below 50 K followed by temperature programmed desorption (TPD) (low temperature TPD) as a selective gas concentration technique. We studied two specific gases in the normal air; krypton as an inert gas and acetone as a reactive gas. We evaluated the relationship between the operating condition of low temperature TPD and the lowest detection limit. In the case of krypton, we observed the selective concentration by exposing at 6 K followed by thermal desorption at about 60 K. On the other hand, no selectivity appeared for acetone although trace acetone was successfully concentrated. This is likely due to the solvent effect by a major component in the air, which is suggested to be water. We suggest that pre-condensation to remove the water component may improve the selectivity in the trace acetone analysis by low temperature TPD.

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

Science.gov (United States)

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. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of acetone-soaking treatment on the performance of polymer solar cells based on P3HT/PCBM bulk heterojunction

International Nuclear Information System (INIS)

Liu Yu-Xuan; Lü Long-Feng; Ning Yu; Lu Yun-Zhang; Lu Qi-Peng; Zhang Chun-Mei; Fang Yi; Hu Yu-Feng; Lou Zhi-Dong; Teng Feng; Hou Yan-Bing; Tang Ai-Wei

2014-01-01

The improvement of the acetone-soaking treatment to the performance of polymer solar cells based on the P3HT/PCBM bulk heterojunction is reported. Undergoing acetone-soaking, the PCBM does not distribute uniformly in the vertical direction, a PCBM enrichment layer forms on the top of the active layer, which is beneficial to the collection of the carriers and blocking the inverting diffusion carriers. X-ray photoelectron spectroscopy (XPS) analysis reveals that the PCBM weight ratio on the top of the active layer increases by 20% after the acetone-soaking treatment. Due to the nonuniform distribution of PCBM, the short-circuit current density, the open-circuit voltage, and the fill factor are enhanced significantly. Finally, the power conversion efficiency of the acetone-soaking device increases by 31% compared with the control device. (interdisciplinary physics and related areas of science and technology)

Lithium isotope effects in cation exchange chromatography of lithium lactate in water-dimethyl sulfoxide and water-acetone mixed solvent media

International Nuclear Information System (INIS)

Oi, Takao; Kondoh, Akiko; Ohno, Etsuko; Hosoe, Morikazu

1993-01-01

Lithium isotope separation by ion exchange displacement chromatography of lithium lactate in water-dimethyl sulfoxide (DMSO) and water-acetone mixed solvent media at 25 C was explored. In both the water-DMSO and water-acetone system, the single stage isotope separation factor (S) was a convex function of the mixing ratio of the solvents in the external solution phase; S had its maximum value of 1.00254 at water: DMSO=25:75 v/v and 1.00182 at water: acetone=75:25 v/v. Strong correlations of S with solvent partitions between the solution and the exchanger phases were found in both systems, which was qualitatively explainable by considering the lithium isotope distributions between the two phases based on the fundamental lithium isotope effects and the relative affinities of water, DMSO and acetone towards the lithium ion. (orig.)

KINETIC STUDY OF SELECTIVE GAS-PHASE OXIDATION OF ISOPROPANOL TO ACETONE USING MONOCLINIC ZRO2 AS A CATALYST

Directory of Open Access Journals (Sweden)

Mohammad Sadiq

2015-08-01

Full Text Available Zirconia was prepared by a precipitation method and calcined at 723 K, 1023 K, and 1253 K in order to obtain monoclinic zirconia. The prepared zirconia was characterized by XRD, SEM, EDX, surface area and pore size analyzer, and particle size analyzer. Monoclinic ZrO2 as a catalyst was used for the gas-phase oxidation of isopropanol to acetone in a Pyrex-glass-flow-type reactor with a temperature range of 443 K - 473 K. It was found that monoclinic ZrO2 shows remarkable catalytic activity (68% and selectivity (100% for the oxidation of isopropanol to acetone. This kinetic study reveals that the oxidation of isopropanol to acetone follows the L-H mechanism.

Fermentation of molasses-flour mashes by acetone-butanol bacteria

Energy Technology Data Exchange (ETDEWEB)

Chekasina, E V

1962-01-01

With Clostridium acetobutylicum used in a continuous fermentation, where the mash passes through 5 to 12 fermenters, sufficient conversion of starch to mono- and disaccharides will occur; the number of fermenters were chosen and mash changed so that fresh mash remains for 34 hours in the cycle. After a 29 hour fermentation average yields were: acetone 4.5, ethanol 3.0, butanol 7.5%.

Radiation-induced peroxidation of egg lecithin liposomes

International Nuclear Information System (INIS)

Bisby, R.H.; Cundall, R.B.; Tomaszewski, K.E.; Coleman, M.H.; Gould, G.

1983-01-01

Peroxidation of multilamellar vesicles of egg lecithin was measured following γ-irradiation of oxygen saturated suspensions. The addition of hydroxyl radical scavengers and the enzymes superoxide dismutase and catalase was used to show that hydroxyl radicals were the major species initiating peroxidation. Superoxide radicals were found to be much less effective initiators of peroxidation. Trolox C, a water soluble analogue of vitamin E, was found to act as an efficient antioxidant in this system. (author)

Analysis of the origin and importance of acetone and isopropanol levels in the blood of the deceased for medico-legal testimony.

Science.gov (United States)

Borowska-Solonynko, A; Siwińska-Ziółkowska, A; Piotrkowicz, M; Wysmołek, M; Demkow, M

2014-01-01

The aim of the study was to analyze the incidence of acetone and isopropanol in the blood of the deceased, and to assess cases in which the compounds have been detected with a focus on their origin and usefulness for medico-legal testimony. The study material consisted of results of tests detecting ethyl alcohol and reports of autopsies performed at the Department of Forensic Medicine, Medical University of Warsaw, from January 2008 to April 2009 - a total of 2,475 cases. The test group proper (group B) comprised only those cases in which acetone was detected in blood, either with or without isopropanol [n = 202 (8.2%)]. The blood levels of isopropanol varied depending on the cause of death. The need for differentiating the origin of isopropanol in the case of its presence in the blood of the deceased was pointed out. The results of the present study show that the differentiation should be based on the isopropanol and acetone concentration ratio, as isopropanol concentration alone is not sufficient for preparing expert opinions. Even high concentrations of isopropanol, when accompanied by even higher concentrations of acetone, imply that isopropanol could have been formed as a result of acetone transformations. Isopropanol concentrations exceeding acetone levels strongly point to the exogenous origin of isopropanol, particularly when high levels of ethanol are concurrently detected.

7 CFR 58.431 - Hydrogen peroxide.

Science.gov (United States)

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 U.S...

Cross-Selectivity Enhancement of Poly(vinylidene fluoride-hexafluoropropylene-Based Sensor Arrays for Detecting Acetone and Ethanol

Directory of Open Access Journals (Sweden)

Ali Daneshkhah

2017-03-01

Full Text Available Two methods for cross-selectivity enhancement of porous poly(vinylidene fluoride-hexafluoropropylene (PVDF-HFP/carbon black (CB composite-based resistive sensors are provided. The sensors are tested with acetone and ethanol in the presence of humid air. Cross-selectivity is enhanced using two different methods to modify the basic response of the PVDF-HFP/CB sensing platform. In method I, the adsorption properties of PVDF-HFP/CB are altered by adding a polyethylene oxide (PEO layer or by treating with infrared (IR. In method II, the effects of the interaction of acetone and ethanol are enhanced by adding diethylene carbonate (DEC or PEO dispersed in DEC (PEO/DEC to the film. The results suggest the approaches used in method I alter the composite ability to adsorb acetone and ethanol, while in method II, they alter the transduction characteristics of the composite. Using these approaches, sensor relative response to acetone was increased by 89% compared with the PVDF-HFP/CB untreated film, whereas sensor relative response to ethanol could be decreased by 57% or increased by 197%. Not only do these results demonstrate facile methods for increasing sensitivity of PVDF-HFP/CB film, used in parallel they demonstrate a roadmap for enhancing system cross-selectivity that can be applied to separate units on an array. Fabrication methods, experimental procedures and results are presented and discussed.

PEROXIDE PROCESS FOR SEPARATION OF RADIOACTIVE MATERIALS

Science.gov (United States)

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.

Antioxidant effect of bisphosphonates and simvastatin on chondrocyte lipid peroxidation

International Nuclear Information System (INIS)

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.; De Clerck, L.S.

2006-01-01

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 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 2+ /EDTA complex to t-BHP or hydrogen peroxide (H 2 O 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 2+ /EDTA complex was added to t-BHP or H 2 O 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

Studies on the in vitro time kill assessment of crude acetone and ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... infection even after treating such wounds with H. pedunculatum leaf. Perhaps .... acetone extract was evaporated to dryness under reduced pressure at 40oC ... ml of Mueller Hinton broth and recovery medium containing 3%.

Comparison of formol-acetone concentration method with that of the ...

African Journals Online (AJOL)

Bernt Lindtjorn

which consists of ether as a fat solvent for detecting out parasites from intestinal debris and thus increases the positivity rates, is believed to be superior over the other ... and petrol can be a better substitute (5, 6, 7). However, among these solvents, acetone has been rated as “safe” in comparison to the ether effect on health ...

Evaluation of the Acetone and Aqueous Extracts of Mature Stem Bark of Sclerocarya birrea for Antioxidant and Antimicrobial Properties

Directory of Open Access Journals (Sweden)

Nicoline F. Tanih

2012-01-01

Full Text Available We assayed the antimicrobial activity of acetone and aqueous extracts of the stem bark of Sclerocarya birrea on some selected bacteria and fungi species including; Streptococcus pyogenes, Plesiomonas shigelloides, Aeromonas hydrophila, Salmonella typhimurium, Cryptococcus neoformans, Candida glabrata, Trichosporon mucoides, and Candida krusei using both agar well diffusion and minimum inhibitory concentration (MIC assays. Based on the levels of activity, the acetone extract was examined for total polyphenolic content, radical scavenging and antioxidant activities. Total phenols of the extract were determined spectrophotometrically. The antioxidant activity was determined by the DPPH, ABTS and reducing power. All the bacteria and fungi species were susceptible to the plant extracts. The acetone extract was the most active for the bacterial species with MIC (0.156–0.625 mg/mL while the aqueous extract was the most active for the fungi species with MIC (0.3125–1.25 mg/mL. The polyphenolic compounds were found as 27.2 mg/g tannic acid equivalent, 25.2 mg/g quercetin equivalent, 9.1 mg/g quercetin equivalent for phenols, flavonoid and flavonols respectively. The acetone extract exhibited a remarkable ability to scavenge radicals, strong reducing ability and a potential source of natural antioxidants. Both the acetone and aqueous extracts of S. birrea may provide a target for drug discovery.

Microsomal lipid peroxidation as a mechanism of cellular damage. [Dissertation

Energy Technology Data Exchange (ETDEWEB)

Kornbrust, D.J.

1979-01-01

The NADPH/iron-dependent peroxidation of lipids in rat liver microsomes was found to be dependent on the presence of free ferrous ion and maintains iron in the reduced Fe/sup 2 +/ state. Chelation of iron by EDTA inhibited peroxidation. Addition of iron, after preincubation of microsomes in the absence of iron, did not enhance the rate of peroxidation suggesting that iron acts by initiating peroxidative decomposition of membrane lipids rather than by catalyzing the breakdown of pre-formed hydroperoxides. Liposomes also underwent peroxidation in the presence of ferrous iron at a rate comparable to intact microsomes and was stimulated by ascorbate. Carbon tetrachloride initiated lipid peroxidation in the absence of free metal ions. Rates of in vitro lipid peroxidation of microsomes and homogenates were found to vary widely between different tissues and species. The effects of paraquat on lipid peroxidation was also studied. (DC)

Mechanisms of DNA damage by the tumor promoter and progressor benzoyl peroxide

International Nuclear Information System (INIS)

Swauger, J.E.; Dolan, P.M.; Zweier, J.L.; Kensler, T.W.

1990-01-01

Benzoyl peroxide (BzPO), a tumor promoter and progressor in mouse skin, produces strand breaks in DNA of exposed cells. Previously we have reported that the metabolism of BzPO in keratinocytes proceeds via the initial cleavage of the peroxide bond, yielding benzoyloxyl radicals which, in turn, can fragment to form phenyl radicals and carbon dioxide. Benzoic acid, the product of hydrogen abstraction by the benzoyloxyl radical, is the major stable metabolite of BzPO produced by keratinocytes. In the present study we have examined the capacity of BzPO to generate strand scissions in φX-174 plasmid DNA. DNA damage was dose-dependent over a concentration range of 10-1000 μM BzPO and was dependent on the presence of copper but not other transition state metals. By contrast, benzoic acid did not produce DNA damage in this system. The inclusion of spin trapping agents (PBN, DBNBS), radical scavenging agents (Nal, GSH), or the copper chelator o-phenanthroline in incubations was found to significantly reduce the extent of DNA damage. Electron paramagnetic resonance spectroscopy studies suggested that the primary radical trapped was the benzoyloxyl radical, implying a role for this radical in the generation of the observed DNA damage. Collectively these observations suggest BzPO may be activated to DNA damaging intermediates in keratinocytes via metal-catalyzed cleavage of the peroxide bond resulting in the formation of the benzoyloxyl radical. Covalent modification of DNA was not observed when [ 14 C]BzPO was incubated with calf thymus DNA in the presence of copper. Overall, these results suggest that BzPO induces DNA damage via benzoyloxyl radical mediated proton abstraction from the DNA strand and the adduct formation with DNA is unlikely to occur

Inorganic precursor peroxides for antifouling coatings

DEFF Research Database (Denmark)

Olsen, S.M.; Pedersen, L.T.; Hermann, M.H.

2009-01-01

Modern antifouling coatings are generally based on cuprous oxide (Cu2O) and organic biocides as active ingredients. Cu2O is prone to bioaccumulation, and should therefore be replaced by more environmentally benign compounds when technically possible. However, cuprous oxide does not only provide...... antifouling properties, it is also a vital ingredient for the antifouling coating to obtain its polishing and leaching mechanism. In this paper, peroxides of strontium, calcium, magnesium, and zinc are tested as pigments in antifouling coatings. The peroxides react with seawater to create hydrogen peroxide...... matrix provides antifouling properties exceeding those of a similar coating based entirely on zinc oxide....

Biological activities of Umbilicaria crustulosa (Ach.) frey acetone extract

OpenAIRE

Zlatanović Ivana; Stanković Miroslava; Stankov-Jovanović Vesna; Mitić Violeta; Zrnzević Ivana; Đorđević Aleksandra; Stojanović Gordana

2017-01-01

This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC) method. Additionally, the total phenolic compounds (TPC) and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteri...

EFFLUENT TREATMENT FACILITY PEROXIDE DESTRUCTION CATALYST TESTING

International Nuclear Information System (INIS)

HALGREN DL

2008-01-01

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

The Effect of Acetone Amount Ratio as Co-Solvent to Methanol in Transesterification Reaction of Waste Cooking Oil

Science.gov (United States)

Julianto, T. S.; Nurlestari, R.

2018-04-01

The production of biodiesel from waste cooking oil by transesterification reaction using acetone as co-solvent has been carried out. This research studied the optimal amount ratio of acetone as co-solvent to methanol in the transesterification process using homogeneous alkaline catalyst KOH 1% (w/w) of waste cooking oil at room temperature for 15 minutes of reaction time. Mole ratio of waste cooking oil to methanol is 1:12. Acetone was added as co-solvent in varied amount ratio to methanol are 1:4, 1:2, and 1:1, respectively. The results of fatty acid methyl esters (FAME) were analysed using GC-MS instrument. The results showed that the optimal ratio is 1:4 with 99.93% of FAME yield.

Atmospheric hydrogen peroxide and organic hydroperoxides during PRIDE-PRD'06, China: their concentration, formation mechanism and contribution to secondary aerosols

Science.gov (United States)

Hua, W.; Chen, Z. M.; Jie, C. Y.; Kondo, Y.; Hofzumahaus, A.; Takegawa, N.; Chang, C. C.; Lu, K. D.; Miyazaki, Y.; Kita, K.; Wang, H. L.; Zhang, Y. H.; Hu, M.

2008-11-01

Atmospheric hydrogen peroxide (H2O2) and organic hydroperoxides were measured from 18 to 30 July in 2006 during the PRIDE-PRD'06 campaign at Backgarden, a rural site located 48 km north of Guangzhou, a mega-city in southern China. A ground-based instrument was used as a scrubbing coil collector to sample ambient air, followed by on-site analysis by high-performance liquid chromatography (HPLC) coupled with post-column derivatization and fluorescence detection. The H2O2 mixing ratio over the 13 days ranged from below the detection limit to a maximum of 4.6 ppbv, with a mean (and standard deviation) of (1.26±1.24) ppbv during the daytime (08:00 20:00 LT). Methyl hydroperoxide (MHP), with a maximum of 0.8 ppbv and a mean (and standard deviation) of (0.28±0.10) ppbv during the daytime, was the dominant organic hydroperoxide. Other organic peroxides, including bis-hydroxymethyl hydroperoxide (BHMP), peroxyacetic acid (PAA), hydroxymethyl hydroperoxide (HMHP), 1-hydroxy-ethyl hydroperoxide (1-HEHP) and ethyl hydroperoxide (EHP), were detected occasionally. The concentration of H2O2 exhibited a pronounced diurnal variation on sunny days, with a peak mixing ratio in the afternoon (12:00 18:00 LT), but lacked an explicit diurnal cycle on cloudy days. Sometimes a second peak mixing ratio of H2O2 was observed during the evening, suggesting that H2O2 was produced by the ozonolysis of alkenes. The diurnal variation profile of MHP was, in general, consistent with that of H2O2. The estimation indicated that in the morning the H2O2 detected was formed mostly through local photochemical activity, with the rest probably attributable to vertical transport. It is notable that relatively high levels of H2O2 and MHP were found in polluted air. The unexpectedly high level of HO2 radicals detected in this region can account for the production of hydroperoxides, while the moderate level of NOx suppressed the formation of hydroperoxides. High concentrations of hydroperoxides were detected

Ionizing radiation and lipid peroxidation in human body

International Nuclear Information System (INIS)

Giubileo, Gianfranco

1997-07-01

Lipids are organic compounds constituting the living cells. Lipid molecules can be disassembled through peroxidative pathways and hydrocarbons can be bred as end-product of lipid peroxidation in vivo. Lipid peroxidation can be started by an indirect effect of ionizing radiation. So a radioinduced cellular damage in human body can be detected by monitoring the production of specific hydrocarbons

Structural effect of ferrocenecarboxymethylated polymers on their electrical behavior under the exposure to methanol and acetone vapors

International Nuclear Information System (INIS)

Hachawee, Kosin; Lerdwijitjarud, Wanchai; Sittattrakul, Amnard; Sirivat, Anuvat

2008-01-01

Functionalized ferrocenecarboxymethylated polymers, i.e. poly(vinylbenzyl ferrocenecarboxymethylate) (PVBFCC), poly(vinylbenzyl ferrocenecarboxymethylate-co-ethoxyethylmethacrylate) with the mole ratio between vinylbenzyl ferrocenecarboxymethylate and ethoxyethylmethacrylate of 75:25 (Co-PVBFCC 75/25) and 50:50 (Co-PVBFCC 50/50), and ferrocenecarboxymethylated polysulfone (BPSFCC) were investigated for their electrical behavior under the vapors of methanol and acetone and nitrogen gas. Electrical conductivity responses of the four ferrocenecarboxymethylated polymers in the presence of lithium perchlorate were measured when they were exposed to nitrogen gas, and methanol and acetone vapors. Main factors that affect the electrical conductivity and sensitivity of these electroactive ferrocene polymers originate from the polymer structure and the type of the passing gas or vapor. Ferrocenecarboxymethylated polymers with higher degrees of substitution of ferrocene units possess good electrical conductivity under the atmosphere of mixed N 2 /methanol vapor, while ferrocenecarboxymethylated polymers with more flexible chain and/or larger free volumes give higher electrical conductivity under the atmosphere of mixed N 2 /acetone vapor. The gas or vapor molecule with higher polarity and smaller size enhances the electrical conductivity of the ferrocene polymers. Our results clearly indicate that the synthesized ferrocenecarboxymethylated polymers have potential to be used as methanol or acetone sensor materials

Induction of antioxidant enzyme activity and lipid peroxidation level in ion-beam-bombarded rice seeds

Energy Technology Data Exchange (ETDEWEB)

Semsang, Nuananong, E-mail: nsemsang@gmail.com [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, LiangDeng [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

2013-07-15

Highlights: ► Ion beam bombarded rice seeds in vacuum. ► Studied seed survival from the ion bombardment. ► Determined various antioxidant enzyme activities and lipid peroxidation level. ► Discussed vacuum, ion species and ion energy effects. ► Attributed the changes to free radical formation due to ion bombardment. -- Abstract: Low-energy ion beam bombardment has been used to mutate a wide variety of plant species. To explore the indirect effects of low-energy ion beam on biological damage due to the free radical production in plant cells, the increase in antioxidant enzyme activities and lipid peroxidation level was investigated in ion-bombarded rice seeds. Local rice seeds were bombarded with nitrogen or argon ion beams at energies of 29–60 keV and ion fluences of 1 × 10{sup 16} ions cm{sup −2}. The activities of the antioxidant enzymes; superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST) and lipid peroxidation level were assayed in the germinated rice seeds after ion bombardment. The results showed most of the enzyme activities and lipid peroxidation levels in both the argon and nitrogen bombarded samples were higher than those in the natural control. N-ion bombardment could induce higher levels of antioxidant enzyme activities in the rice samples than the Ar-ion bombardment. Additional effects due to the vacuum condition were found to affect activities of some antioxidant enzymes and lipid peroxidation level. This study demonstrates that ion beam bombardment and vacuum condition could induce the antioxidant enzyme activity and lipid peroxidation level which might be due to free radical production in the bombarded rice seeds.

PROCESS OF ELIMINATING HYDROGEN PEROXIDE IN SOLUTIONS CONTAINING PLUTONIUM VALUES

Science.gov (United States)

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.

Direct electron transfer biosensor for hydrogen peroxide carrying nanocomplex composed of horseradish peroxidase and Au-nanoparticle – Characterization and application to bienzyme systems

Directory of Open Access Journals (Sweden)

Yusuke Okawa

2015-09-01

Full Text Available A reagentless electrochemical biosensor for hydrogen peroxide was fabricated. The sensor carries a monolayer of nanocomplex composed of horseradish peroxidase and Au-nanoparticle, and responds to hydrogen peroxide through the highly efficient direct electron transfer at a mild electrode potential without any soluble mediator. Formation of the nanocomplex was studied with visible spectroscopy and size exclusion chromatography. The sensor performance was analyzed based on a hydrodynamic electrochemical technique and enzyme kinetics. The sensor was applied to fabrication of sensors for glucose and uric acid through further modification of the nanocomplex-carrying electrode with the corresponding hydrogen peroxide-generating oxidases, glucose oxidase and urate oxidase, respectively.

Comparison of voiding function and nociceptive behavior in two rat models of cystitis induced by cyclophosphamide or acetone

Science.gov (United States)

Saitoh, Chikashi; Yokoyama, Hitoshi; Chancellor, Michael B.; de Groat, William C.; Yoshimura, Naoki

2009-01-01

Aims Nociceptive behavior and its relationship with bladder dysfunction were investigated in two cystitis models, which were induced by intraperitoneal (ip) injection of cyclophosphamide (CYP) or intravesical instillation of acetone, using freely moving, non-catheterized conscious rats. Methods Female Sprague-Dawley rats were used. Cystitis was induced by ip injection of CYP (100 and 200mg/kg) or intravesical instillation of acetone (10, 30 and 50%) via a polyethylene catheter temporarily inserted into the bladder through the urethra. Then the incidence of nociceptive behavior (immobility with decreased breathing rates) was scored. Voided urine was collected simultaneously and continuously to measure bladder capacity. The plasma extravasation in the bladder was quantified by an evans blue (EB) dye leakage technique. Results CYP (100mg/kg, ip) induced nociceptive behavior without affecting bladder capacity or EB concentration in the bladder. A higher dose of CYP (200mg/kg, ip) decreased bladder capacity and increased EB levels as well as nociceptive behavior. In contrast, intravesical instillation of acetone (30%) decreased bladder capacity and increased EB levels, but evoked nociceptive behavior less frequently compared with CYP-treated animals. In capsaicin pretreated rats, nociceptive behavior induced by CYP or acetone was reduced; however, the overall effects of CYP or acetone on bladder capacity and bladder EB levels were unaffected. Conclusions These results suggest that there is a difference in the induction process of nociceptive behavior and small bladder capacity after two different types of bladder irritation and that C-fiber sensitization is more directly involved in pain sensation than reduced bladder capacity. PMID:19618450

Comparative studies of citric acid, acetone-butanol, and alcohol fermentation processes in beet molasses from several sugar factories

Energy Technology Data Exchange (ETDEWEB)

Kovats, J; Zuckerind, Z

1963-01-01

Citric acid (I) fermentation is the most sensitive to volatile acids and coloring matter contents of molasses, and butanol fermentation, the least. Citric acid and alcohol production decrease as volatile acids and coloring matter increase, but this last factor has a favorable effect on the acetone-butanol fermentation. Molasses which are suitable for citric acid production are also suitable for alcohol but not always for acetone-butanol.

The human gastric pathogen Helicobacter pylori has a potential acetone carboxylase that enhances its ability to colonize mice

Directory of Open Access Journals (Sweden)

Weinberg Michael V

2008-01-01

Full Text Available Abstract Background Helicobacter pylori colonizes the human stomach and is the etiological agent of peptic ulcer disease. All three H. pylori strains that have been sequenced to date contain a potential operon whose products share homology with the subunits of acetone carboxylase (encoded by acxABC from Xanthobacter autotrophicus strain Py2 and Rhodobacter capsulatus strain B10. Acetone carboxylase catalyzes the conversion of acetone to acetoacetate. Genes upstream of the putative acxABC operon encode enzymes that convert acetoacetate to acetoacetyl-CoA, which is metabolized further to generate two molecules of acetyl-CoA. Results To determine if the H. pylori acxABC operon has a role in host colonization the acxB homolog in the mouse-adapted H. pylori SS1 strain was inactivated with a chloramphenicol-resistance (cat cassette. In mouse colonization studies the numbers of H. pylori recovered from mice inoculated with the acxB:cat mutant were generally one to two orders of magnitude lower than those recovered from mice inoculated with the parental strain. A statistical analysis of the data using a Wilcoxin Rank test indicated the differences in the numbers of H. pylori isolated from mice inoculated with the two strains were significant at the 99% confidence level. Levels of acetone associated with gastric tissue removed from uninfected mice were measured and found to range from 10–110 μmols per gram wet weight tissue. Conclusion The colonization defect of the acxB:cat mutant suggests a role for the acxABC operon in survival of the bacterium in the stomach. Products of the H. pylori acxABC operon may function primarily in acetone utilization or may catalyze a related reaction that is important for survival or growth in the host. H. pylori encounters significant levels of acetone in the stomach which it could use as a potential electron donor for microaerobic respiration.

Radiation effect on lipid peroxide content of spices

International Nuclear Information System (INIS)

Kaneko, Nobutada; Ito, Hitoshi; Ishigaki, Isao

1990-01-01

To evaluate the radiation-induced deterioration of lipid in spices, peroxide value, iodine value and acid value were measured after extraction by chloroform. Peroxide values of black pepper and white pepper were not increased by gamma-irradiation with doses below 30 kGy and gradually increased at higher dose up to 80 kGy in this study. On contrary, peroxide values of clove and rosemary increased rather quickly below 20 kGy of gamma-irradiation, and they became stationary at higher dose. Iodine values and acid values had relationship with peroxide values on each kind of spices. On the storage study of irradiated spices, peroxide values decreased quickly during 20 days storage as same as nonirradiated spices, and it became stationary after 20 to 50 days storage at 30degC. Enhancement of oxidized deterioration were not observed even higher irradiation doses up to 80 kGy in this study. (author)

Mechanism of ascorbic acid interference in biochemical tests that use peroxide and peroxidase to generate chromophore.

Science.gov (United States)

Martinello, Flávia; Luiz da Silva, Edson

2006-11-01

Ascorbic acid interferes negatively in peroxidase-based tests (Trinder method). However, the precise mechanism remains unclear for tests that use peroxide, a phenolic compound and 4-aminophenazone (4-AP). We determined the chemical mechanism of this interference, by examining the effects of ascorbic acid in the reaction kinetics of the production and reduction of the oxidized chromophore in urate, cholesterol, triglyceride and glucose tests. Reaction of ascorbic acid with the Trinder method constituents was also verified. Ascorbic acid interfered stoichiometrically with all tests studied. However, it had two distinct effects on the reaction rate. In the urate test, ascorbic acid decreased the chromophore formation with no change in its production kinetics. In contrast, in cholesterol, triglyceride and glucose tests, an increase in the lag phase of color development occurred. Of all the Trinder constituents, only peroxide reverted the interference. In addition, ascorbic acid did not interfere with oxidase activity nor reduce significantly the chromophore formed. Peroxide depletion was the predominant chemical mechanism of ascorbic acid interference in the Trinder method with phenolics and 4-AP. Distinctive effects of ascorbic acid on the reaction kinetics of urate, cholesterol, glucose and triglyceride might be due to the rate of peroxide production by oxidases.

Cathodic reduction of benzil in acetone and in dichloromethane

Energy Technology Data Exchange (ETDEWEB)

Quintanilla, Gloria [Departamento de Quimica Organica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)], E-mail: gloria.quintanilla@uah.es; Liebeck, Miriam; Bengtsson, Carina; Arnold, Lena; Barba, Fructuoso [Departamento de Quimica Organica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)

2008-02-15

The cathodic reduction of benzil has been carried out at a controlled potential on a mercury cathode in two different SSE (solvent-supporting-electrolyte) conditions: (a) acetone/lithium perchlorate in absence of electrophile where 2,3-diphenyl-5-methyl-furan and 1,2-diphenyl-2-hydroxy-1,4-pentanedione were obtained as main products and (b) dichloromethane/tetrabuthylammonium chloride with the addition of oxalyl chloride as electrophile, where a fast electron transfer took place.

On the Formation of Interstellar Water Ice: Constraints from a Search for Hydrogen Peroxide Ice in Molecular Clouds

Science.gov (United States)

Smith, R. G.; Charnely, S. B.; Pendleton, Y. J.; Wright, C. M.; Maldoni, M. M.; Robinson, G.

2011-01-01

Recent surface chemistry experiments have shown that the hydrogenation of molecular oxygen on interstellar dust grains is a plausible formation mechanism, via hydrogen peroxide (H2O2), for the production of water (H2O) ice mantles in the dense interstellar medium. Theoretical chemistry models also predict the formation of a significant abundance of H2O2 ice in grain mantles by this route. At their upper limits, the predicted and experimental abundances are sufficiently high that H2O2 should be detectable in molecular cloud ice spectra. To investigate this further, laboratory spectra have been obtained for H2O2/H2O ice films between 2.5 and 200 micron, from 10 to 180 K, containing 3%, 30%, and 97% H2O2 ice. Integrated absorbances for all the absorption features in low-temperature H2O2 ice have been derived from these spectra. For identifying H2O2 ice, the key results are the presence of unique features near 3.5, 7.0, and 11.3 micron. Comparing the laboratory spectra with the spectra of a group of 24 protostars and field stars, all of which have strong H2O ice absorption bands, no absorption features are found that can definitely be identified with H2O2 ice. In the absence of definite H2O2 features, the H2O2 abundance is constrained by its possible contribution to the weak absorption feature near 3.47 micron found on the long-wavelength wing of the 3 micron H2O ice band. This gives an average upper limit for H2O2, as a percentage of H2O, of 9% +/- 4%. This is a strong constraint on parameters for surface chemistry experiments and dense cloud chemistry models.

Green synthesis of nanosilver as a sensor for detection of hydrogen peroxide in water

International Nuclear Information System (INIS)

Shukla, Vineet K.; Yadav, Raghvendra S.; Yadav, Poonam; Pandey, Avinash C.

2012-01-01

Highlights: ► Present “green” synthesis is an efficient, easy-going, fast, renewable, inexpensive, eco-friendly and non-toxic approach. ► TEM shows average particle size of 8.25 ± 1.37 nm of synthesized nanosilver, giving UV–vis absorption at 410 nm. ► FTIR confirms Azadirachtin as reducing and stabilizing agent for nanosilver formation (stability up to three months). ► The nanosilver modified electrode (Ag/GC) exhibited an excellent electro-catalytic activity toward the reduction of hydrogen peroxide (H 2 O 2 ). ► The recovery percentage of H 2 O 2 in water is 92–105%, which is applicable for sensors and water/waste water plants. - Abstract: Present “green” synthesis is an efficient, easy-going, fast, renewable, inexpensive, eco-friendly and non-toxic approach for nanosilver formation, which offers numerous benefits over physiochemical approaches. The X-ray diffraction (XRD) pattern suggests the formation and crystallinity of nanosilver. The average particle size of silver nanoparticles was 8.25 ± 1.37 nm as confirmed by transmission electron microscopy (TEM). The UV–vis absorption spectrum shows a characteristic absorption peak of silver nanoparticles at 410 nm. FTIR confirms Azadirachtin as reducing and stabilizing agent for nanosilver formation. In addition, the nanosilver modified electrode (Ag/GC) exhibited an excellent electro-catalytic activity toward the reduction of hydrogen peroxide (H 2 O 2 ). The produced nanosilver is stable and comparable in size. These silver nanoparticles show potential applications in the field of sensors, catalysis, fuel cells and nanodevices.

Electron thermal capacity in plasma generated at cavitation bubble collapse in D-acetone

International Nuclear Information System (INIS)

Kostenko, B.F.; Pribis, J.

2004-01-01

The latest experimental data on nuclear reaction product registration at cavitation bubble collapse in deuterated acetone (C 3 D 6 O) still argue in favour of existence of a new possibility to realize the thermonuclear synthesis. Theoretical description based on numerical solution of simultaneous conservation equations for gaseous and liquid phases also confirms this possibility, although it requires further more precise definitions. In particular, description of electron degrees of freedom in dense nonequilibrium plasma generated at the final stage of bubble collapse need specification. Calculations of electron thermal capacity in the deuterated acetone multiple ionization region at electron temperatures T e ≅ 10 4 K and above and compression range ρ/ρ 0 ≅ 1 - 100 have been fulfilled on the basis of direct numerical solution of equation for chemical potential. (author)

Biodegradation of isopropanol and acetone under denitrifying conditions by Thauera sp. TK001 for nitrate-mediated microbially enhanced oil recovery.

Science.gov (United States)

Fida, Tekle Tafese; Gassara, Fatma; Voordouw, Gerrit

2017-07-15

Amendment of reservoir fluid with injected substrates can enhance the growth and activity of microbes. The present study used isopropyl alcohol (IPA) or acetone to enhance the indigenous anaerobic nitrate-reducing bacterium Thauera sp. TK001. The strain was able to grow on IPA or acetone and nitrate. To monitor effects of strain TK001 on oil recovery, sand-packed columns containing heavy oil were flooded with minimal medium at atmospheric or high (400psi) pressure. Bioreactors were then inoculated with 0.5 pore volume (PV) of minimal medium containing Thauera sp. TK001 with 25mM of acetone or 22.2mM of IPA with or without 80mM nitrate. Incubation without flow for two weeks and subsequent injection with minimal medium gave an additional 17.0±6.7% of residual oil in place (ROIP) from low-pressure bioreactors and an additional 18.3% of ROIP from the high-pressure bioreactors. These results indicate that acetone or IPA, which are commonly used organic solvents, are good substrates for nitrate-mediated microbial enhanced oil recovery (MEOR), comparable to glucose, acetate or molasses, tested previously. This technology may be used for coupling biodegradation of IPA and/or acetone in waste streams to MEOR where these waste streams are generated in close proximity to an oil field. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrogen peroxide probes directed to different cellular compartments.

OpenAIRE

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

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 ...

Synergistic effects of sodium 
ascorbate and acetone to restore compromised bond strength 
after enamel bleaching.

Science.gov (United States)

Boruziniat, Alireza; Manafi, Safa; Cehreli, Zafer C

To evaluate the effect of a new experimental solution containing sodium ascorbate (SA) and acetone on reversing compromised bonding to enamel immediately after bleaching. The buccal surface of intact, extracted human premolars (n = 60) was bleached. The teeth were then randomly assigned to 6  groups according to the type of pretreatment applied prior to adhesive procedures: 10% SA in acetone-water solution applied for 1 and 5 min (groups 1 and 2, respectively); aqueous solution of 10% SA applied for 10 min (group 3); 100% acetone applied for 10 min (group 4); no pretreatment (negative control; group 5). An additional group (positive control; group 6) comprised unbleached teeth (n = 12). Two composite microcylinders were bonded on each specimen for evaluation of microshear bond strength (MBS) and failure modes. Data were analyzed using the one-way ANOVA and Tukey's post-hoc and chi-square tests at P = 0.05. Groups 1 and 2 yielded similar MBS values to groups 4 and 6 (positive control). The mean MBS of groups 3 and 5 (negative control) were similar, and significantly lower than that of the positive control group. The application of 10% SA in an acetone-water solution prior to bonding procedures can restore compromised enamel bond strength to its unbleached state within a clinically acceptable time of 1 min.

Peculiar behavior of MWW materials in aldol condensation of furfural and acetone

Czech Academy of Sciences Publication Activity Database

Kikhtyanin, O.; Eliášová, Pavla; Jindrová, T.; Kubička, D.

2014-01-01

Roč. 43, č. 27 (2014), s. 10628-10641 ISSN 1477-9226 R&D Projects: GA ČR GBP106/12/G015 Institutional support: RVO:61388955 Keywords : acetone * aldehydes * batch reactors Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.197, year: 2014

Treatment of acetone waste gases using slurry-phase airlift embedded with polyacrylamide-entrapped cell beads.

Science.gov (United States)

Hwang, Sz-Chwun John; Lin, Yun-Huin; Huang, Ku Shu; Lyuu, Jyuhn-Yih; Hou, Cheng-Ting; Chen, Hsin-Hua; He, Sin-Yi

2009-10-01

Acetone is the most common chemical used in the Hsin-chu Science Park in Taiwan. The three-phase airlift bioreactor was designed to absorb acetone into the 39 L of medium solution and then degraded by 2-L polyacrylamide (PAA)-entrapped Thiosphaera pantotropha cell beads. The airlift medium was successfully regenerated and circulated for more than 5 months. The elimination capacity of 350-part per million (ppm) acetone at 10 L x min(-1) was 258.4 g x m(-3) hr(-1) (160.4 g-C x m(-3) hr(-1)) with 100% removal efficiency in Stage II, higher than previously reported biofiltration results. The maximum chemical oxygen demand:nitrogen ratio of 100:2.9 is achieved, and a balanced nutrient state was indicated by the change in redox potential. The pH of the system was maintained at neutral because of the strong buffer agent added to the medium (final buffer intensity, beta = 1.18 x 10(-2) M). The PAA-entrapped cell beads could also provide a good barrier for high salinity gradient environment and the inoculum source to maintain steady operation of the system.

The combustion chemistry of a fuel tracer: Measured flame speeds and ignition delays and a detailed chemical kinetic model for the oxidation of acetone

Energy Technology Data Exchange (ETDEWEB)

Pichon, S.; Black, G.; Simmie, J.M.; Curran, H.J. [Combustion Chemistry Centre, National University of Ireland, Galway (Ireland); Chaumeix, N.; Yahyaoui, M. [Institut de Combustion Aerothermique Reactivite et Environnement, CNRS, Orleans (France); Donohue, R. [Information Technology, National University of Ireland, Galway (Ireland)

2009-02-15

Acetone ignition delay and stretch-free laminar flame speed measurements have been carried out and a kinetic model has been developed to simulate these and literature data for acetone and for ketene, which was found to be an important intermediate in its oxidation. The mechanism has been based on one originally devised for dimethyl ether and modified through validation of the hydrogen, carbon monoxide and methane sub-mechanisms. Acetone oxidation in argon was studied behind reflected shock waves in the temperature range 1340-1930 K, at 1 atm and at equivalence ratios of 0.5, 1 and 2; it is also shown that the addition of up to 15% acetone to a stoichiometric n-heptane mixture has no effect on the measured ignition delay times. Flame speeds at 298 K and 1 atm of pure acetone in air were measured in a spherical bomb; a maximum flame speed of {proportional_to}35 cm s{sup -1} at {phi}=1.15 is indicated. (author)

Recent advances on conversion and co-production of acetone-butanol-ethanol into high value-added bioproducts.

Science.gov (United States)

Xin, Fengxue; Dong, Weiliang; Jiang, Yujia; Ma, Jiangfeng; Zhang, Wenming; Wu, Hao; Zhang, Min; Jiang, Min

2018-06-01

Butanol is an important bulk chemical and has been regarded as an advanced biofuel. Large-scale production of butanol has been applied for more than 100 years, but its production through acetone-butanol-ethanol (ABE) fermentation process by solventogenic Clostridium species is still not economically viable due to the low butanol titer and yield caused by the toxicity of butanol and a by-product, such as acetone. Renewed interest in biobutanol as a biofuel has spurred technological advances to strain modification and fermentation process design. Especially, with the development of interdisciplinary processes, the sole product or even the mixture of ABE produced through ABE fermentation process can be further used as platform chemicals for high value added product production through enzymatic or chemical catalysis. This review aims to comprehensively summarize the most recent advances on the conversion of acetone, butanol and ABE mixture into various products, such as isopropanol, butyl-butyrate and higher-molecular mass alkanes. Additionally, co-production of other value added products with ABE was also discussed.

Dissociative electron attachment studies on acetone

International Nuclear Information System (INIS)

Prabhudesai, Vaibhav S.; Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E.

2014-01-01

Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H − is found to be the most dominant fragment followed by O − and OH − with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H − and O − fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance

Cloning, functional expression and characterization of a bifunctional 3-hydroxybutanal dehydrogenase /reductase involved in acetone metabolism by Desulfococcus biacutus.

Science.gov (United States)

Frey, Jasmin; Rusche, Hendrik; Schink, Bernhard; Schleheck, David

2016-11-25

The strictly anaerobic, sulfate-reducing bacterium Desulfococcus biacutus can utilize acetone as sole carbon and energy source for growth. Whereas in aerobic and nitrate-reducing bacteria acetone is activated by carboxylation with CO 2 to acetoacetate, D. biacutus involves CO as a cosubstrate for acetone activation through a different, so far unknown pathway. Proteomic studies indicated that, among others, a predicted medium-chain dehydrogenase/reductase (MDR) superfamily, zinc-dependent alcohol dehydrogenase (locus tag DebiaDRAFT_04514) is specifically and highly produced during growth with acetone. The MDR gene DebiaDRAFT_04514 was cloned and overexpressed in E. coli. The purified recombinant protein required zinc as cofactor, and accepted NADH/NAD + but not NADPH/NADP + as electron donor/acceptor. The pH optimum was at pH 8, and the temperature optimum at 45 °C. Highest specific activities were observed for reduction of C 3 - C 5 -aldehydes with NADH, such as propanal to propanol (380 ± 15 mU mg -1 protein), butanal to butanol (300 ± 24 mU mg -1 ), and 3-hydroxybutanal to 1,3-butanediol (248 ± 60 mU mg -1 ), however, the enzyme also oxidized 3-hydroxybutanal with NAD + to acetoacetaldehyde (83 ± 18 mU mg -1 ). The enzyme might play a key role in acetone degradation by D. biacutus, for example as a bifunctional 3-hydroxybutanal dehydrogenase/reductase. Its recombinant production may represent an important step in the elucidation of the complete degradation pathway.

Achieving concentrated graphene dispersions in water/acetone mixtures by the strategy of tailoring Hansen solubility parameters

International Nuclear Information System (INIS)

Yi Min; Shen Zhigang; Zhang Xiaojing; Ma Shulin

2013-01-01

Although exfoliating graphite to give graphene paves a new way for graphene preparation, a general strategy of low-boiling-point solvents and high graphene concentration is still highly required. In this study, using the strategy of tailoring Hansen solubility parameters (HSP), a method based on exfoliation of graphite in water/acetone mixtures is demonstrated to achieve concentrated graphene dispersions. It is found that in the scope of blending two mediocre solvents, tailoring the HSP of water/acetone mixtures to approach the HSP of graphene could yield graphene dispersions at a high concentration of up to 0.21 mg ml -1 . The experimentally determined optimum composition of the mixtures occurs at an acetone mass fraction of ∼75%. The trend of concentration varying with mixture compositions could be well predicated by the model, which relates the concentration to the mixing enthalpy within the scope of HSP theory. The resultant dispersion is highly stabilized. Atomic force microscopic statistical analysis shows that up to ∼50% of the prepared nanosheets are less than 1 nm thick after 4 h sonication and 114g centrifugation. Analyses based on diverse characterizations indicate the graphene sheets to be largely free of basal plane defects and oxidation. The filtered films are also investigated in terms of their electrical and optical properties to show reasonable conductivity and transparency. The strategy of tailoring HSP, which can be easily extended to various solvent systems, and water/acetone mixtures here, extends the scope for large-scale production of graphene in low-boiling-point solutions.

Investigation of hydrolysis products in the acetone-butanol fermentation of vegetable agricultural waste materials

Energy Technology Data Exchange (ETDEWEB)

Nakhmanovich, B M

1960-01-01

Determinations of the fundamental chemical composition of corn stalk, sunflower husk, and hemp scutch by chromatography were reported, e.g. pentoses (1.98, 1.98, 2.01%), hexoses (1.59, 1.72, 2.01% respectively.) and various amino acids (arginine, asparagine, histidine, glutamine, glycine, lysine, proline, serine, tyrosine, threonine, cysteine, cystine, alanine, and aspartic and glutamic acids). The sterilized products from the hydrolysis (pentoses, hexoses) in a combined mixture with a meal mash were normally fermented at 37/sup 0/ in the presence of acetone-butanol bacteria for 40 to 48 hours, yielding 10.46 to 12.50% of acetone, 15.09 to 18.0% of butanol, 3.79 to 6.08% of ethanol (a total yielding being 30 to 42% of solvents).

Modulatory effect of Scoparia dulcis in oxidative stress-induced lipid peroxidation in streptozotocin diabetic rats.

Science.gov (United States)

Latha, M; Pari, L

2003-01-01

In light of evidence that diabetes mellitus is associated with oxidative stress and altered antioxidant status, we investigated the effect of Scoparia dulcis plant extracts (SPEt) (aqueous, ethanolic, and chloroform) in streptozotocin diabetic rats. Significant increases in the activities of insulin, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, reduced glutathione, vitamin C, and vitamin E were observed in liver, kidney, and brain on treatment with SPEt. In addition, the treated groups also showed significant decreases in blood glucose, thiobarbituric acid-reactive substances, and hydroperoxide formation in tissues, suggesting its role in protection against lipid peroxidation-induced membrane damage. Thus, the results of the present study indicate that extracts of S. dulcis, especially the aqueous extract, showed a modulatory effect by attenuating the above lipid peroxidation in streptozotocin diabetes.

Ergosterol Peroxide Isolated from Ganoderma lucidum Abolishes MicroRNA miR-378-Mediated Tumor Cells on Chemoresistance

Science.gov (United States)

Li, Xiang-Min; Yang, Weining; Jiao, Chun-Wei; Fang, Ling; Li, Sen-Zhu; Pan, Hong-Hui; Yee, Albert J.; Lee, Daniel Y.; Li, Chong; Zhang, Zhi; Guo, Jun; Yang, Burton B.

2012-01-01

Due to an altered expression of oncogenic factors and tumor suppressors, aggressive cancer cells have an intrinsic or acquired resistance to chemotherapeutic agents. This typically contributes to cancer recurrence after chemotherapy. microRNAs are short non-coding RNAs that are involved in both cell self-renewal and cancer development. Here we report that tumor cells transfected with miR-378 acquired properties of aggressive cancer cells. Overexpression of miR-378 enhanced both cell survival and colony formation, and contributed to multiple drug resistance. Higher concentrations of chemotherapeutic drugs were needed to induce death of miR-378-transfected cells than to induce death of control cells. We found that the biologically active component isolated from Ganoderma lucidum could overcome the drug-resistance conferred by miR-378. We purified and identified the biologically active component of Ganoderma lucidum as ergosterol peroxide. We demonstrated that ergosterol peroxide produced greater activity in inducing death of miR-378 cells than the GFP cells. Lower concentrations of ergosterol peroxide were needed to induce death of the miR-378-transfected cells than in the control cells. With further clinical development, ergosterol peroxide represents a promising new reagent that can overcome the drug-resistance of tumor cells. PMID:22952996

Photofragment spectrum of acetone

International Nuclear Information System (INIS)

Hancock, Graham; Wilson, K.R.

1974-01-01

The photodissociation of acetone at 266.2 nm has been investigated by photofragment spectroscopy. A molecular beam of CH 3 COCH 3 is crossed by pulses of polarized uv light from a powerful fourth harmonic neodymium laser system, and the recoiling CH 3 and CH 3 CO photofragments detected with a quadrupole mass spectrometer. Both the flight time distributions and the masses of the fragments are measured, leading to a determination of the energy partitioning in the photodissociation process; it is found that the methyl and acetyl fragments together carry 43% of the available energy in translation, with the remaining 57% in fragment internal excitation. The angular distribution of fragments with respect to the polarization direction of the laser beam was found to be isotropic. The long lifetime of the initially produced singlet state should give a smoothing of the angular distribution, and this tendency towards isotropy could be further increased by a non-planar mode of dissociation of the excited molecule. Both statistical and impulsive dissociation models can fit the observed average energy partitioning, with present data enable to distinguish between the two possibilities, which, however, could be differentiated with further crossed molecular and laser beam experiments

Electron Thermal Capacity in Plasma Generated at Cavitation Bubble Collapse in D-acetone

CERN Document Server

Kostenko, B F

2004-01-01

The latest experimental data on nuclear reaction product registration at cavitation bubble collapse in deuterated acetone (C$_3$D$_6$O) still argue in favour of existence of a new possibility to realize the thermonuclear synthesis. Theoretical description based on numerical solution of simultaneous conservation equations for gaseous and liquid phases also confirms this possibility, although it requires further more precise definitions. In particular, description of electron degrees of freedom in very dense nonequilibrium plasma generated at the final stage of bubble collapse needs specification. In the present paper, calculations of electron thermal capacity in the deuterated acetone multiple ionization region at electron temperatures $T_e \\simeq 10^4 $ K and above and compression range $\\rho/\\rho_0 \\simeq 1 \\div 100$ have been fulfilled on the basis of direct numerical solution of equation for chemical potential.

A chemiluminescent method for determination of lipid peroxidation

International Nuclear Information System (INIS)

Liang Xiaofeng; Hu Tianxi; Fan Xiaobing

2003-01-01

We established a chemiluminescent system for determination of lipid peroxidation and screening anti-oxidants. The lipid containing unsaturated fatly acids was injected into a galls tube. Luminol solution and the deionized water were added into it too. The glass tube was put into a preincubation box to incubate it for 0.5 h at 37 degree C. AAPH solution was injected into the tube for immediate measurement in a biochemiluminometer at 38-39 degree C. The pulses /6s(CP6s) were determined with T-2 program. Chemiluminescent dynamic and lipid peroxidation changes were observed continuously. Once the CL intensity of lipid peroxidation got peak, the antioxidant which has different concentration was added immediately in situ. A certain CL intensity (CP6s) was chosen as evaluation index to compare the activity of antioxidants. A luminol chemiluminescent system for determination of lipid peroxidation has been made. It was found that Vit. C, teapolyphenol, and glutathione have effects on scavenging lipid free radicals. The new method is quick, sensitive, and simple for determination of lipid peroxidation and screening antioxidants

Synthesis and thermal properties of strontium and calcium peroxides

Science.gov (United States)

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.

Determination of active oxygen content in rare earth peroxides

International Nuclear Information System (INIS)

Queiroz, Carlos A.S.; Abrao, Alcidio

1993-01-01

The content of active oxygen in rare earth peroxides have been determined after the dissolution of the samples with hydrocloridic acid in the presence of potassium iodide. The free generated iodine is titrated with sodium thiosulfate using starch as indicator. The oxidation of iodide to the free iodine indicates the presence of a higher valence state rare earth oxide, until now specifically recognized for the oxides of cerium (Ce O 2 ), praseodymium (Pr 6 O 1 1) and terbium (TB 4 O 7 ). recently the authors synthesized a new series of rare earth compounds, the peroxides. These new compounds were prepared by precipitating the rare earth elements complexed with carbonate ion by addition of hydrogen peroxide. the authors demonstrated that all rare earth elements, once solubilized by complexing with carbonate ion, are quantitatively precipitated as peroxide by addition of hydrogen peroxide. (author)

Determination and modeling of binary and ternary solid-liquid phase equilibrium for the systems formed by 3,5-dinitrobenzoic acid, m-nitrobenzoic acid and acetone

International Nuclear Information System (INIS)

Li, Xinbao; Du, Cunbin; Zhao, Hongkun

2017-01-01

Highlights: • The solubility of 3,5-dinitrobenzoic acid in acetone was determined. • Solubility of m-nitrobenzoic acid + 3,5-dinitrobenzoic acid + acetone was determined. • Three ternary phase diagrams were constructed for the ternary system. • The ternary phase diagrams were calculated by Wilson model and NRTL model. - Abstract: The solubility of 3,5-dinitrobenzoic acid in acetone at the temperatures ranging from (283.15 to 318.15) K and the mutual solubility of the ternary m-nitrobenzoic acid + 3,5-dinitrobenzoic acid + acetone system at (283.15, 298.15 and 313.15) K were determined experimentally by using the isothermal saturation method under atmosphere pressure (101.2 kPa). Three isothermal ternary phase diagrams were constructed according to the measured mutual solubility data. In each ternary phase diagram, there was one co-saturated point, two boundary curves, and three crystalline regions. The modified Apelblat equation, λh equation, NRTL model and Wilson model were used to correlate the solubility of 3,5-dinitrobenzoic acid in acetone; and the NRTL and Wilson models, the mutual solubility for the ternary m-nitrobenzoic acid + 3,5-dinitrobenzoic acid + acetone system. The value of root-mean-square deviation (RMSD) was 8.53 × 10 −4 for the binary system of 3,5-dinitrobenzoic acid + acetone; and the largest value of RMSD was 81.08 × 10 −4 for the ternary system.

The problem of peroxidation in radiolis logy

International Nuclear Information System (INIS)

Baraboj, V.A.; Chebotarev, E.E.

1986-01-01

A hypothesis is validated concerning the products of freeradical oxidation of lipids and the phenol compounds as a mediator of the stress-syndrome. The data are reviewed on activation of peroxidation under the effect of radiation, cytochemical agents, etc., secondarily stimulating the neurohumoral system function of homeostasis regulation. With the emotional-algesic and cold-stresses, the regulatory system stimulation is of primary, reflex, nature, but it secondarily promotes the peroxidation activation. The radiotoxins (of the quinoid and lipid nature) appearing in tissues under the effect of ionizing radiation, are smilar in structure and mechanism of action to peroxidation activation products formed under the effect of other stress-agents

Laminar burning velocities of acetone in air at room and elevated temperatures

NARCIS (Netherlands)

Nilsson, E.J.K.; Goey, de L.P.H.; Konnov, A.

2013-01-01

Laminar burning velocities of acetone + air mixtures at initial gas mixture temperatures of 298, 318, 338 and 358 K are reported. Non-stretched flames were stabilized on a perforated plate burner at 1 atm, and laminar burning velocities were determined using the heat flux method, at conditions where

Oxidative damage of U937 human leukemic cells caused by hydroxyl radical results in singlet oxygen formation.

Directory of Open Access Journals (Sweden)

Marek Rác

Full Text Available The exposure of human cells to oxidative stress leads to the oxidation of biomolecules such as lipids, proteins and nuclei acids. In this study, the oxidation of lipids, proteins and DNA was studied after the addition of hydrogen peroxide and Fenton reagent to cell suspension containing human leukemic monocyte lymphoma cell line U937. EPR spin-trapping data showed that the addition of hydrogen peroxide to the cell suspension formed hydroxyl radical via Fenton reaction mediated by endogenous metals. The malondialdehyde HPLC analysis showed no lipid peroxidation after the addition of hydrogen peroxide, whereas the Fenton reagent caused significant lipid peroxidation. The formation of protein carbonyls monitored by dot blot immunoassay and the DNA fragmentation measured by comet assay occurred after the addition of both hydrogen peroxide and Fenton reagent. Oxidative damage of biomolecules leads to the formation of singlet oxygen as conformed by EPR spin-trapping spectroscopy and the green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. It is proposed here that singlet oxygen is formed by the decomposition of high-energy intermediates such as dioxetane or tetroxide formed by oxidative damage of biomolecules.

Preparation and Characterization of Epoxy Resin Cross-Linked with High Wood Pyrolysis Bio-Oil Substitution by Acetone Pretreatment

Directory of Open Access Journals (Sweden)

Yi Liu

2017-03-01

Full Text Available The use of cost effective solvents may be necessary to store wood pyrolysis bio-oil in order to stabilize and control its viscosity, but this part of the production system has not been explored. Conversely, any rise in viscosity during storage, that would occur without a solvent, will add variance to the production system and render it cost ineffective. The purpose of this study was to modify bio-oil with a common solvent and then react the bio-oil with an epoxy for bonding of wood without any loss in properties. The acetone pretreatment of the bio-oil/epoxy mixture was found to improve the cross-linking potential and substitution rate based on its mechanical, chemical, and thermal properties. Specifically, the bio-oil was blended with epoxy resin at weight ratios ranging from 2:1 to 1:5 and were then cured. A higher bio-oil substitution rate was found to lower the shear bond strength of the bio-oil/epoxy resins. However, when an acetone pretreatment was used, it was possible to replace the bio-oil by as much as 50% while satisfying usage requirements. Extraction of the bio-oil/epoxy mixture with four different solvents demonstrated an improvement in cross-linking after acetone pretreatment. ATR-FTIR analysis confirmed that the polymer achieved a higher cross-linked structure. DSC and TGA curves showed improved thermal stability with the addition of the acetone pretreatment. UV-Vis characterization showed that some functional groups of the bio-oil to epoxy system were unreacted. Finally, when the resin mixture was utilized to bond wood, the acetone pretreatment coupled with precise tuning of the bio-oil:epoxy ratio was an effective method to control cross-linking while ensuring acceptable bond strength.

A path integral molecular dynamics study of the hyperfine coupling constants of the muoniated and hydrogenated acetone radicals

Energy Technology Data Exchange (ETDEWEB)

Oba, Yuki; Kawatsu, Tsutomu; Tachikawa, Masanori, E-mail: tachi@yokohama-cu.ac.jp [Quantum Chemistry Division, Yokohama City University, Seto 22-2, Kanazawa-ku, Yokohama 236-0027 (Japan)

2016-08-14

The on-the-fly ab initio density functional path integral molecular dynamics (PIMD) simulations, which can account for both the nuclear quantum effect and thermal effect, were carried out to evaluate the structures and “reduced” isotropic hyperfine coupling constants (HFCCs) for muoniated and hydrogenated acetone radicals (2-muoxy-2-propyl and 2-hydoxy-2-propyl) in vacuo. The reduced HFCC value from a simple geometry optimization calculation without both the nuclear quantum effect and thermal effect is −8.18 MHz, and that by standard ab initio molecular dynamics simulation with only the thermal effect and without the nuclear quantum effect is 0.33 MHz at 300 K, where these two methods cannot distinguish the difference between muoniated and hydrogenated acetone radicals. In contrast, the reduced HFCC value of the muoniated acetone radical by our PIMD simulation is 32.1 MHz, which is about 8 times larger than that for the hydrogenated radical of 3.97 MHz with the same level of calculation. We have found that the HFCC values are highly correlated with the local molecular structures; especially, the Mu—O bond length in the muoniated acetone radical is elongated due to the large nuclear quantum effect of the muon, which makes the expectation value of the HFCC larger. Although our PIMD result calculated in vacuo is about 4 times larger than the measured experimental value in aqueous solvent, the ratio of these HFCC values between muoniated and hydrogenated acetone radicals in vacuo is in reasonable agreement with the ratio of the experimental values in aqueous solvent (8.56 MHz and 0.9 MHz); the explicit presence of solvent molecules has a major effect on decreasing the reduced muon HFCC of in vacuo calculations for the quantitative reproduction.

A path integral molecular dynamics study of the hyperfine coupling constants of the muoniated and hydrogenated acetone radicals

International Nuclear Information System (INIS)

Oba, Yuki; Kawatsu, Tsutomu; Tachikawa, Masanori

2016-01-01

The on-the-fly ab initio density functional path integral molecular dynamics (PIMD) simulations, which can account for both the nuclear quantum effect and thermal effect, were carried out to evaluate the structures and “reduced” isotropic hyperfine coupling constants (HFCCs) for muoniated and hydrogenated acetone radicals (2-muoxy-2-propyl and 2-hydoxy-2-propyl) in vacuo. The reduced HFCC value from a simple geometry optimization calculation without both the nuclear quantum effect and thermal effect is −8.18 MHz, and that by standard ab initio molecular dynamics simulation with only the thermal effect and without the nuclear quantum effect is 0.33 MHz at 300 K, where these two methods cannot distinguish the difference between muoniated and hydrogenated acetone radicals. In contrast, the reduced HFCC value of the muoniated acetone radical by our PIMD simulation is 32.1 MHz, which is about 8 times larger than that for the hydrogenated radical of 3.97 MHz with the same level of calculation. We have found that the HFCC values are highly correlated with the local molecular structures; especially, the Mu—O bond length in the muoniated acetone radical is elongated due to the large nuclear quantum effect of the muon, which makes the expectation value of the HFCC larger. Although our PIMD result calculated in vacuo is about 4 times larger than the measured experimental value in aqueous solvent, the ratio of these HFCC values between muoniated and hydrogenated acetone radicals in vacuo is in reasonable agreement with the ratio of the experimental values in aqueous solvent (8.56 MHz and 0.9 MHz); the explicit presence of solvent molecules has a major effect on decreasing the reduced muon HFCC of in vacuo calculations for the quantitative reproduction.

Green synthesis of nanosilver as a sensor for detection of hydrogen peroxide in water

Energy Technology Data Exchange (ETDEWEB)

Shukla, Vineet K., E-mail: vineet2shukla@gmail.com [Nanotechnology Application Centre, Faculty of Science, University of Allahabad, Allahabad 211002 (India); Department of Physics, Faculty of Science, University of Allahabad, Allahabad 211002 (India); Yadav, Raghvendra S. [Nanotechnology Application Centre, Faculty of Science, University of Allahabad, Allahabad 211002 (India); Yadav, Poonam [National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Pandey, Avinash C. [Nanotechnology Application Centre, Faculty of Science, University of Allahabad, Allahabad 211002 (India)

2012-04-30

Highlights: Black-Right-Pointing-Pointer Present 'green' synthesis is an efficient, easy-going, fast, renewable, inexpensive, eco-friendly and non-toxic approach. Black-Right-Pointing-Pointer TEM shows average particle size of 8.25 {+-} 1.37 nm of synthesized nanosilver, giving UV-vis absorption at 410 nm. Black-Right-Pointing-Pointer FTIR confirms Azadirachtin as reducing and stabilizing agent for nanosilver formation (stability up to three months). Black-Right-Pointing-Pointer The nanosilver modified electrode (Ag/GC) exhibited an excellent electro-catalytic activity toward the reduction of hydrogen peroxide (H{sub 2}O{sub 2}). Black-Right-Pointing-Pointer The recovery percentage of H{sub 2}O{sub 2} in water is 92-105%, which is applicable for sensors and water/waste water plants. - Abstract: Present 'green' synthesis is an efficient, easy-going, fast, renewable, inexpensive, eco-friendly and non-toxic approach for nanosilver formation, which offers numerous benefits over physiochemical approaches. The X-ray diffraction (XRD) pattern suggests the formation and crystallinity of nanosilver. The average particle size of silver nanoparticles was 8.25 {+-} 1.37 nm as confirmed by transmission electron microscopy (TEM). The UV-vis absorption spectrum shows a characteristic absorption peak of silver nanoparticles at 410 nm. FTIR confirms Azadirachtin as reducing and stabilizing agent for nanosilver formation. In addition, the nanosilver modified electrode (Ag/GC) exhibited an excellent electro-catalytic activity toward the reduction of hydrogen peroxide (H{sub 2}O{sub 2}). The produced nanosilver is stable and comparable in size. These silver nanoparticles show potential applications in the field of sensors, catalysis, fuel cells and nanodevices.

Relationships between changes in Holstein cow’s body condition, acetone and urea content in milk and cervical mucus and sperm survival

Directory of Open Access Journals (Sweden)

Jan Beran

2012-01-01

Full Text Available The objectives of this study were to evaluate the relationship between changes in Holstein cow’s body condition score (BCS, acetone and urea content in the milk and cervical mucus (CM and sperm survival in CM. At insemination, samples of milk and CM were collected from 64 Holstein cows. Content of acetone and urea were determined. Sperm motility was assessed subjectively at the beginning and after 30, 60 and 90 minutes of the short-term heat test in CM. Data about evaluation of cow’s BCS were taken from farm evidence. The data set was analyzed using SAS/STAT software. Effect of change in cow’s BCS one month before insemination was significant only in relation to the acetone content in milk (P < 0.05. Higher values of acetone and urea content were found in the CM compared to milk. Higher levels of both metabolites were detected in primiparous cows and in cows on the third and subsequent lactation, resp. in cows inseminated 3 times and more. The highest values of both metabolites negatively affected sperm survival during the short-term heat test, especially after 90 minutes (P < 0.05–0.01. Significant decreases (P < 0.05–0.01 were detected in cows with the highest level of acetone and urea.

Electricity generation and removal performance of a microbial fuel cell using sulfonated poly (ether ether ketone) as proton exchange membrane to treat phenol/acetone wastewater.

Science.gov (United States)

Wu, Hao; Fu, Yu; Guo, Chunyu; Li, Yanbo; Jiang, Nanzhe; Yin, Chengri

2018-07-01

The microbial fuel cell (MFC) has emerged as a promising technology for wastewater treatment and energy recovery, but the expensive cost of proton exchange membranes (PEMs) is a problem that need to be solved. In this study, a two-chamber MFC based on our self-made PEM sulfonated poly (ether ether ketone) membrane was set up to treat phenol/acetone wastewater and synchronously generate power. The maximum output voltage was 240-250 mV. Using phenol and acetone as substrates, the power generation time in an operation cycle was 289 h. The MFC exhibited good removal performance, with no phenol or acetone detected, respectively, when the phenol concentration was lower than 50 mg/L and the acetone concentration was lower than 100 mg/L. This study provides a cheap and eco-friendly way to treat phenol/acetone wastewater and generate useful energy by MFC technology. Copyright © 2018 Elsevier Ltd. All rights reserved.

Lipid peroxidation, occupational stress and aging in workers of a prehospital emergency service.

Science.gov (United States)

Casado, Angela; De Lucas, Nieves; López-Fernández, Encarnación; Sánchez, Alberto; Jimenez, José-Antonio

2006-06-01

Stressful conditions lead to formation of excessive free radicals, and lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products. To determine the levels of malondialdehyde, an end product of lipid peroxidation, according to demographic and occupational variables in workers of a prehospital emergency service and to analyse the relationship between malondialdehyde levels and burnout. One hundred and eleven healthy workers of a prehospital emergency service and eighty aged-matched healthy individuals of both sexes as a control group were surveyed. Malondialdehyde levels were measured by the Bull and Marnett method. To measure burnout, the Maslach Burnout Inventory was used. Professional category is associated with lipid peroxidation and burnout levels (Malondialdehyde levels were: physicians 338.10+/-14.47, nurses 329.17+/-12.62 and technicians 296.74+/-14.28; burnout levels were: physicians 41.29+/-3.59, nurses 37.38+/-6.05 and technicians 35.33+/-5.87). Working at night and in the evening increased malondialdehyde and burnout levels. Malondialdehyde levels increase with age. No significant variations with respect to sex were detected. Significant variations in malondialdehyde levels were detected between singles (303.13+/-12.74) and married people (344.43+/-13.43) but not with respect to divorcees (326.44+/-11.74). Significant differences were detected in erythrocyte malondialdehyde levels between smokers (341.37+/-17.09) and nonsmokers (302.21+/-12.38), but not for alcohol consumption. These findings suggest a positive correlation between malondialdehyde, a biomarker of lipid peroxidation and occupational stress, as estimated by elements of the Maslach Burnout Inventory, and oxidative stress.

Determination and modeling of the solubility of (limonin in methanol or acetone + water) binary solvent mixtures at T = 283.2 K to 318.2 K

International Nuclear Information System (INIS)

Fan, Jie-Ping; Zheng, Bing; Liao, Dan-Dan; Yu, Jia-Xin; Cao, Ya-Hui; Zhang, Xue-Hong; Zhu, Jian-Hang

2016-01-01

Highlights: • The solubilities of limonin were measured in the binary solvent mixtures methanol + water and acetone + water. • The solubility data were correlated by nine models. • The solubility of limonin had a maximum point at 0.9 mol fraction of acetone in acetone + water mixtures. - Abstract: The solubility of limonin in the binary solvent mixtures (methanol + water) and (acetone + water) with various initial mole fractions of methanol or acetone was measured by high-performance liquid chromatography (HPLC) at different temperatures ranging from 283.2 K to 318.2 K. The solubility of limonin increased with increasing initial mole fraction of methanol in (methanol + water) mixtures, whereas it had a maximum point at 0.9 mol fraction of acetone in (acetone + water) mixtures. The solubility of limonin increased with increasing temperature in the two binary solvent mixtures. The solubility of limonin was correlated with temperature by the van’t Hoff model and the modified Apelblat model, and the fitting results showed that the modified Apelblat model had better correlation. The CNIBS/Redlich–Kister model and the simplified CNIBS/Redlich–Kister model were used to correlate the solubility data with the initial solvent composition, the results show that the CNIBS/Redlich–Kister model reveals better agreement with the experimental values. Furthermore, to illustrate the effects of both temperature and initial solvent composition on the changes in the solubility of limonin, the solubility values were fitted by the Jouyban–Acree, van’t Hoff–Jouyban–Acree, modified Apelblat–Jouyban–Acree, Ma and Sun models. Among the five models, the Jouyban–Acree model give the best correlation results for (methanol + water) binary solvent mixtures, while the experimental solubility in the (acetone + water) system was most accurately correlated by the van’t Hoff–Jouyban–Acree model.

High Resolution Multiphoton Ionization/Dissociation of Molecular Beam of Acetone from 582.60 to 585.80 nm

Science.gov (United States)

Mejia-Ospino, Enrique; Garcia, Gladis; Guerrero, Alfonso; Alvarez, Ignacio; Cisneros, Carmen

2003-05-01

Multiphoton ionization and dissociation of a jet supersonic of acetone at wavelength from 582.60 to 585.80 nm is studied using a Nd:YAG-OPO (optical parametric oscillator) system coupled to time-of-flight mass spectrometer. We present high-resolution (1.5 cm-1) three-photon resonance multiphoton spectra of the acetone 3s CH3CO+), (CH3+) and (COH+), being CH3COCH3+ ---> CH3CO+ + CH3 the more likely channel. The molecular and acetyl ions are observed practically in overall wavelength range.

Effect of hydrogen and propylene on the hydrogen peroxide decomposition over Pt, PtO and Au catalysts

NARCIS (Netherlands)

Kertalli, E.; Schouten, J.C.; Nijhuis, T.A.

2017-01-01

The decomposition of hydrogen peroxide (H2O2) on Pt, PtO and Au catalysts has been investigated in the presence of nitrogen, propylene and hydrogen. H2O2 formation on the catalyst is known to be a key intermediate step for the direct synthesis of propylene oxide (PO) from hydrogen, propylene and

Phosphate-Catalyzed Hydrogen Peroxide Formation from Agar, Gellan, and κ-Carrageenan and Recovery of Microbial Cultivability via Catalase and Pyruvate.

Science.gov (United States)

Kawasaki, Kosei; Kamagata, Yoichi

2017-11-01

Previously, we reported that when agar is autoclaved with phosphate buffer, hydrogen peroxide (H 2 O 2 ) is formed in the resulting medium (PT medium), and the colony count on the medium inoculated with environmental samples becomes much lower than that on a medium in which agar and phosphate are autoclaved separately (PS medium) (T. Tanaka et al., Appl Environ Microbiol 80:7659-7666, 2014, https://doi.org/10.1128/AEM.02741-14). However, the physicochemical mechanisms underlying this observation remain largely unknown. Here, we determined the factors affecting H 2 O 2 formation in agar. The H 2 O 2 formation was pH dependent: H 2 O 2 was formed at high concentrations in an alkaline or neutral phosphate buffer but not in an acidic buffer. Ammonium ions enhanced H 2 O 2 formation, implying the involvement of the Maillard reaction catalyzed by phosphate. We found that other gelling agents (e.g., gellan and κ-carrageenan) also produced H 2 O 2 after being autoclaved with phosphate. We then examined the cultivability of microorganisms from a fresh-water sample to test whether catalase and pyruvate, known as H 2 O 2 scavengers, are effective in yielding high colony counts. The colony count on PT medium was only 5.7% of that on PS medium. Catalase treatment effectively restored the colony count of PT medium (to 106% of that on PS medium). In contrast, pyruvate was not as effective as catalase: the colony count on sodium pyruvate-supplemented PT medium was 58% of that on PS medium. Given that both catalase and pyruvate can remove H 2 O 2 from PT medium, these observations indicate that although H 2 O 2 is the main cause of reduced colony count on PT medium, other unknown growth-inhibiting substances that cannot be removed by pyruvate (but can be by catalase) may also be involved. IMPORTANCE The majority of bacteria in natural environments are recalcitrant to laboratory culture techniques. Previously, we demonstrated that one reason for this is the formation of high H 2 O

Enhancement of Critical Current Density and Flux Pinning in Acetone and La2O3 Codoped MgB2 Tapes

International Nuclear Information System (INIS)

Gao Zhao-Shun; Ma Yan-Wei; Wang Dong-Liang; Zhang Xian-Ping; Awaji Satoshi; Watanabe Kazuo

2010-01-01

MgB 2 tape samples with simultaneous additions of acetone and La 2 O 3 were prepared by an in-situ processed powder-in-tube method. Compared to the pure and single doped tapes, both transport J c and fluxing pinning are greatly improved by acetone and La 2 O 3 codoping. Acetone supplies carbon into the MgB 2 crystal lattice and increases the upper critical field, while the La 2 O 3 reacts with B to form LaB 6 nanoparticles as effective flux pining centers. The improvement of the superconducting properties in codoped tapes can be attributed to the combined effects of improvement in H c2 and flux pinning. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Effect of cadmium chloride on hepatic lipid peroxidation in mice

DEFF Research Database (Denmark)

Andersen, H R; Andersen, O

1988-01-01

Intraperitoneal administration of cadmium chloride to 8-12 weeks old CBA-mice enhanced hepatic lipid peroxidation. A positive correlation between cadmium chloride dose and level of peroxidation was observed in both male and female mice. A sex-related difference in mortality was not observed...... but at a dose of 25 mumol CdCl2/kg the level of hepatic lipid peroxidation was higher in male mice than in female mice. The hepatic lipid peroxidation was not increased above the control level in 3 weeks old mice, while 6 weeks old mice responded with increased peroxidation as did 8-12 weeks old mice....... The mortality after an acute toxic dose of cadmium chloride was the same in the three age groups. Pretreatment of mice with several low intraperitoneal doses of cadmium chloride alleviated cadmium induced mortality and lipid peroxidation. The results demonstrate both age dependency and a protective effect...

PEROXIDE DESTRUCTION TESTING FOR THE 200 AREA EFFLUENT TREATMENT FACILITY

International Nuclear Information System (INIS)

Halgren, D.L.

2010-01-01

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 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.

Origin of Enhanced Reactivity of a Microsolvated Nucleophile in Ion Pair SN2 Reactions: The Cases of Sodium p-Nitrophenoxide with Halomethanes in Acetone.

Science.gov (United States)

Li, Qiang-Gen; Xu, Ke; Ren, Yi

2015-04-30

In a kinetic experiment on the SN2 reaction of sodium p-nitrophenoxide with iodomethane in acetone-water mixed solvent, Humeres et al. (J. Org. Chem. 2001, 66, 1163) found that the reaction depends strongly on the medium, and the fastest rate constant was observed in pure acetone. The present work tries to explore why acetone can enhance the reactivity of the title reactions. Accordingly, we make a mechanistic study on the reactions of sodium p-nitrophenoxide with halomethanes (CH3X, X = Cl, Br, I) in acetone by using a supramolecular/continuum model at the PCM-MP2/6-311+G(d,p)//B3LYP/6-311+G(d,p) level, in which the ion pair nucleophile is microsolvated by one to three acetone molecules. We compared the reactivity of the microsolvated ion pair nucleophiles with solvent-free ion pair and anionic ones. Our results clearly reveal that the microsolvated ion pair nucleophile is favorable for the SN2 reactions; meanwhile, the origin of the enhanced reactivity induced by microsolvation of the nucleophile is discussed in terms of the geometries of transition state (TS) structures and activation strain model, suggesting that lower deformation energies and stronger interaction energies between the deformed reactants in the TS lead to the lower overall reaction barriers for the SN2 reaction of microsolvated sodium p-nitrophenoxide toward halomethanes in acetone.

Study on mechanism of decreased lipid peroxide by low dose radiation

International Nuclear Information System (INIS)

Yamaoka, Kiyonori; Okazoe, Yoko; Akimaru, Kunihiro; Sato, E.F.; Utsumi, Kozo.

1991-01-01

We examined the effect of SOD on lipid peroxidation in biomembrane from V.E-deficient rats, in order to study the mechanism of increased SOD activities and decreased lipid peroxide by low dose irradiation. The following results were obtained. i. Active oxygen (O 2 - ) strongly enhances lipid peroxidations in biomembrane with the Fe 3+ as catalyst. ii. SOD evidently inhibits lipid peroxidations under above conditions. iii. We suggested that the effect of SOD enhanced by low dose irradiation results in inhibition of lipid peroxidation. (author)

Dissociative electron attachment studies on acetone

Energy Technology Data Exchange (ETDEWEB)

Prabhudesai, Vaibhav S., E-mail: vaibhav@tifr.res.in; Tadsare, Vishvesh; Ghosh, Sanat; Gope, Krishnendu; Davis, Daly; Krishnakumar, E. [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India)

2014-10-28

Dissociative electron attachment (DEA) to acetone is studied in terms of the absolute cross section for various fragment channels in the electron energy range of 0–20 eV. H{sup −} is found to be the most dominant fragment followed by O{sup −} and OH{sup −} with only one resonance peak between 8 and 9 eV. The DEA dynamics is studied by measuring the angular distribution and kinetic energy distribution of fragment anions using Velocity Slice Imaging technique. The kinetic energy and angular distribution of H{sup −} and O{sup −} fragments suggest a many body break-up for the lone resonance observed. The ab initio calculations show that electron is captured in the multi-centered anti-bonding molecular orbital which would lead to a many body break-up of the resonance.

Multi-species time-history measurements during high-temperature acetone and 2-butanone pyrolysis

KAUST Repository

Lam, Kingyiu

2013-01-01

High-temperature acetone and 2-butanone pyrolysis studies were conducted behind reflected shock waves using five species time-history measurements (ketone, CO, CH3, CH4 and C2H4). Experimental conditions covered temperatures of 1100-1600 Kat 1.6 atm, for mixtures of 0.25-1.5% ketone in argon. During acetone pyrolysis, the CO concentration time-history was found to be strongly sensitive to the acetone dissociation rate constant κ1 (CH3COCH3 → CH3 + CH3CO), and this could be directly determined from the CO time-histories, yielding κ1(1.6 atm) = 2.46 × 1014 exp(-69.3 [kcal/mol]/RT) s-1 with an uncertainty of ±25%. This rate constant is in good agreement with previous shock tube studies from Sato and Hidaka (2000) [3] and Saxena et al. (2009) [4] (within 30%) at temperatures above 1450 K, but is at least three times faster than the evaluation from Sato and Hidaka at temperatures below 1250 K. Using this revised κ1 value with the recent mechanism of Pichon et al. (2009) [5], the simulated profiles during acetone pyrolysis show excellent agreement with all five species time-history measurements. Similarly, the overall 2-butanone decomposition rate constant κtot was inferred from measured 2-butanone time-histories, yielding κ tot(1.5 atm) = 6.08 × 1013 exp(-63.1 [kcal/mol]/RT) s -1 with an uncertainty of ±35%. This rate constant is approximately 30% faster than that proposed by Serinyel et al. (2010) [11] at 1119 K, and approximately 100% faster at 1412 K. Using the measured 2-butanone and CO time-histories and an O-atom balance analysis, a missing removal pathway for methyl ketene was identified. The rate constant for the decomposition of methyl ketene was assumed to be the same as the value for the ketene decomposition reaction. Using the revised κtot value and adding the methyl ketene decomposition reaction to the Serinyel et al. mechanism, the simulated profiles during 2-butanone pyrolysis show good agreement with the measurements for all five species. �

A study of the relative importance of the peroxiredoxin-, catalase-, and glutathione-dependent systems in neural peroxide metabolism.

Science.gov (United States)

Mitozo, Péricles Arruda; de Souza, Luiz Felipe; Loch-Neckel, Gecioni; Flesch, Samira; Maris, Angelica Francesca; Figueiredo, Cláudia Pinto; Dos Santos, Adair Roberto Soares; Farina, Marcelo; Dafre, Alcir Luiz

2011-07-01

Cells are endowed with several overlapping peroxide-degrading systems whose relative importance is a matter of debate. In this study, three different sources of neural cells (rat hippocampal slices, rat C6 glioma cells, and mouse N2a neuroblastoma cells) were used as models to understand the relative contributions of individual peroxide-degrading systems. After a pretreatment (30 min) with specific inhibitors, each system was challenged with either H₂O₂ or cumene hydroperoxide (CuOOH), both at 100 μM. Hippocampal slices, C6 cells, and N2a cells showed a decrease in the H₂O₂ decomposition rate (23-28%) by a pretreatment with the catalase inhibitor aminotriazole. The inhibition of glutathione reductase (GR) by BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) significantly decreased H₂O₂ and CuOOH decomposition rates (31-77%). Inhibition of catalase was not as effective as BCNU at decreasing cell viability (MTT assay) and cell permeability or at increasing DNA damage (comet test). Impairing the thioredoxin (Trx)-dependent peroxiredoxin (Prx) recycling by thioredoxin reductase (TrxR) inhibition with auranofin neither potentiated peroxide toxicity nor decreased the peroxide-decomposition rate. The results indicate that neural peroxidatic systems depending on Trx/TrxR for recycling are not as important as those depending on GSH/GR. Dimer formation, which leads to Prx2 inactivation, was observed in hippocampal slices and N2a cells treated with H₂O₂, but not in C6 cells. However, Prx-SO₃ formation, another form of Prx inactivation, was observed in all neural cell types tested, indicating that redox-mediated signaling pathways can be modulated in neural cells. These differences in Prx2 dimerization suggest specific redox regulation mechanisms in glia-derived (C6) compared to neuron-derived (N2a) cells and hippocampal slices. Copyright © 2011 Elsevier Inc. All rights reserved.

Coumarins as turn on/off fluorescent probes for detection of residual acetone in cosmetics following headspace single-drop microextraction.

Science.gov (United States)

Cabaleiro, N; de la Calle, I; Bendicho, C; Lavilla, I

2014-11-01

In this work, a new method based on headspace-single drop microextraction for the determination of residual acetone in cosmetics by microfluorospectrometry is proposed. Acetone causes fluorescence changes in a 2.5 µL-ethanolic drop (40% v/v) containing 3.10(-4) mol L(-1) 7-hydroxy-4-methylcoumarin ('turn off') or 6.10(-6) mol L(-1) 7-diethylamino-4-methylcoumarin ('turn on'). Polarity and ability to form hydrogen bonds of short chain alcohols (polar protic solvents) were crucial in order to observe these changes in the presence of acetone (polar aprotic solvent). Parameters related with the HS-SDME procedure were studied, namely headspace volume, composition, volume and temperature of drop, microextraction time, stirring rate, mass and temperature of sample, as well as the effect of potential interferents (alcohols and fragrances). The high volatility of acetone allows its extraction from an untreated cosmetic sample within 3 min. A detection limit of 0.26 µg g(-1) and repeatability, expressed as relative standard deviation, around 5% were reached. Accuracy of the proposed methodology was evaluated by means of recovery studies. The method was successfully used to analyze different cosmetics. Simplicity and high sample throughput can be highlighted. Copyright © 2014 Elsevier B.V. All rights reserved.

Multi-species time-history measurements during high-temperature acetone and 2-butanone pyrolysis

KAUST Repository

Lam, Kingyiu; Ren, Wei; Pyun, Sunghyun; Farooq, Aamir; Davidson, David Frank; Hanson, Ronald Kenneth

2013-01-01

High-temperature acetone and 2-butanone pyrolysis studies were conducted behind reflected shock waves using five species time-history measurements (ketone, CO, CH3, CH4 and C2H4). Experimental conditions covered temperatures of 1100-1600 Kat 1.6 atm

Conversion of Aryl Iodides into Aryliodine(III Dichlorides by an Oxidative Halogenation Strategy Using 30% Aqueous Hydrogen Peroxide in Fluorinated Alcohol

Directory of Open Access Journals (Sweden)

Ajda Podgoršek

2010-04-01

Full Text Available Oxidative chlorination with HCl/H2O2 in 1,1,1-trifluoroethanol was used to transform aryl iodides into aryliodine(III dihalides. In this instance 1,1,1-trifluoroethanol is not only the reaction medium, but is also an activator of hydrogen peroxide for the oxidation of hydrochloric acid to molecular chlorine. Aryliodine(III dichlorides were formed in 72–91% isolated yields in the reaction of aryl iodides with 30% aqueous hydrogen peroxide and hydrochloric acid at ambient temperature. A study of the effect that substituents on the aromatic ring have on the formation and stability of aryliodine(III dichlorides shows that the transformation is easier to achieve in the presence of the electron-donating groups (i.e. methoxy, but in this case the products rapidly decompose under the reported reaction conditions to form chlorinated arenes. The results suggest that oxidation of hydrogen chloride with hydrogen peroxide is the initial reaction step, while direct oxidation of aryl iodide with hydrogen peroxide is less likely to occur.

Effect of using acetone and distilled water on the performance of open loop pulsating heat pipe (OLPHP) with different filling ratios

Science.gov (United States)

Rahman, Md. Lutfor; Afrose, Tonima; Tahmina, Halima Khatun; Rinky, Rumana Parvin; Ali, Mohammad

2016-07-01

Pulsating heat pipe (PHP) is a new innovation in the modern era of miniaturizes thermal management system for its higher heating and cooling capacity. The objective of this experiment is to observe the performance of open loop pulsating heat pipe using two fluids at different filling ratios. This OLPHP is a copper capillary tube of 2.5mm outer diameter and 2mm inner diameter. It consists of 8 loops where the evaporative section is 50mm, adiabatic section is 120mm and condensation section is 80mm. The experiment is conducted with distilled water and acetone at 40%, 50%, 60%, and 70% filling ratios where 0° (vertical) is considered as definite angle of inclination. Distilled water and acetone are selected as working fluids considering their different latent heat of vaporization and surface tension. It is found that acetone shows lower thermal resistance than water at all heat inputs. Best performance of acetone is attained at 70% filling ratio. Water displays better heat transfer capability at 50% filling ratio.

Technical and economic assessment of processes for the production of butanol and acetone

Science.gov (United States)

1982-01-01

This report represents a preliminary technical and economic evaluation of a process which produces mixed solvents (butaol/acetone/ethanol) via fermentation of sugars derived from renewable biomass resources. The objective is to assess the technology of producing butanol/acetone from biomass, and select a viable process capable of serving as a base case model for technical and economic analysis. It is anticipated that the base case process developed herein can then be used as the basis for subsequent studies concerning biomass conversion processes capable of producing a wide range of chemicals. The general criteria utilized in determining the design basis for the process are profit potential and non-renewable energy displacement potential. The feedstock chosen, aspen wood, was selected from a number of potential renewable biomass resources as the most readily available in the United States and for its relatively large potential for producing reducing sugars.

Acetone-water complexes at MRCI level using localized orbitals: n ->pi* and pi ->pi* electronic transitions

DEFF Research Database (Denmark)

Hoyau, S.; Ben Amor, N.; Borini, Stefano

2008-01-01

The n -> pi* and pi -> pi* vertical electronic transitions of acetone with two and four H2O which correspond to a first solvation shell are considered. By using localized orbitals, and thanks to the MRCI approach which permits to know the wave function, the role of the various solvent molecules...... is analysed in details. Distinguishing the solvent molecules allows one to consider them at different calculation levels. The methodology is to compare the spectra obtained with four H2O, with two H2O either in the acetone plane or in a perpendicular plane and when they are completely or partly frozen....

Measurement of endogenous acetone and isoprene in exhaled breath during sleep

International Nuclear Information System (INIS)

King, Julian; Kupferthaler, Alexander; Unterkofler, Karl; Amann, Anton; Frauscher, Birgit; Hackner, Heinz; Högl, Birgit; Teschl, Gerald; Hinterhuber, Hartmann

2012-01-01

This explorative study aims at characterizing the breath behavior of two prototypic volatile organic compounds, acetone and isoprene, during normal human sleep and to possibly relate changes in the respective concentration time courses to the underlying sleep architecture. For this purpose, six normal healthy volunteers (two females, four males, age 20–29 years) were monitored over two consecutive nights (the first one being an adaption night) by combining real-time proton-transfer-reaction mass spectrometry measurements from end-tidal exhalation segments with laboratory-based polysomnographic data. Breath acetone concentrations increased overnight in all measurements, with an average relative change by a factor of up to 4 (median 2.5). Nighttime concentration maxima were usually recorded 2–3 h before lights on. For breath isoprene, a nocturnal increase in baseline concentrations of about 74% was observed, with individual changes ranging from 36–110%. Isoprene profiles exhibited pronounced concentration peaks, which were highly specific for leg movements as scored by tibial electromyography. Furthermore, relative to a linear trend, baseline isoprene concentrations decreased during the transition from the NREM to the REM phase of a complete sleep cycle. (paper)

1-Butyl-3-Methylimidazolium Tetrafluoroborate Film as a Highly Selective Sensing Material for Non-Invasive Detection of Acetone Using a Quartz Crystal Microbalance.

Science.gov (United States)

Tao, Wenyan; Lin, Peng; Liu, Sili; Xie, Qingji; Ke, Shanming; Zeng, Xierong

2017-01-20

Breath acetone serves as a biomarker for diabetes. This article reports 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF₄]), a type of room temperature ionic liquid (RTIL), as a selective sensing material for acetone. The RTIL sensing layer was coated on a quartz crystal microbalance (QCM) for detection. The sensing mechanism is based on a decrease in viscosity and density of the [bmim][BF₄] film due to the solubilization of acetone leading to a positive frequency shift in the QCM. Acetone was detected with a linear range from 7.05 to 750 ppmv. Sensitivity and limit of detection were found to be 3.49 Hz/ppmv and 5.0 ppmv, respectively. The [bmim][BF₄]-modified QCM sensor demonstrated anti-interference ability to commonly found volatile organic compounds in breath, e.g., isoprene, 1,2-pentadiene, d -limonene, and dl -limonene. This technology is useful for applications in non-invasive early diabetic diagnosis.

Formation of hydrogen peroxide in cell culture media by apple polyphenols and its effect on antioxidant biomarkers in the colon cell line HT-29.

Science.gov (United States)

Bellion, Phillip; Olk, Melanie; Will, Frank; Dietrich, Helmut; Baum, Matthias; Eisenbrand, Gerhard; Janzowski, Christine

2009-10-01

Beneficial health effects of diets containing fruits have partly been attributed to polyphenols which display a spectrum of bioactive effects, including antioxidant activity. However, polyphenols can also exert prooxidative effects in vitro. In this study, polyphenol-mediated hydrogen peroxide (H(2)O(2)) formation was determined after incubation of apple juice extracts (AEs) and polyphenols in cell culture media. Effects of extracellular H(2)O(2 )on total glutathione (tGSH; =GSH + GSSG) and cellular reactive oxygen species (ROS) level of HT-29 cells were studied by coincubation +/- catalase (CAT). AEs ( > or =30 microg/mL) significantly generated H(2)O(2) in DMEM, depending on their composition. Similarly, H(2)O(2) was measured for individual apple polyphenols/degradation products (phenolic acids > epicatechin, flavonols > dihydrochalcones). Highest concentrations were generated by compounds bearing the o-catechol moiety. H(2)O(2) formation was found to be pH dependent; addition of CAT caused a complete decomposition of H(2)O(2) whereas superoxide dismutase was less/not effective. At incubation of HT-29 cells with quercetin (1-100 microM), generated H(2)O(2) slightly contributed to antioxidant cell protection by modulation of tGSH- and ROS-level. In conclusion, H(2)O(2) generation in vitro by polyphenols has to be taken into consideration when interpreting results of such cell culture experiments. Unphysiologically high polyphenol concentrations, favoring substantial H(2)O(2 )formation, are not expected to be met in vivo, even under conditions of high end nutritional uptake.

Synthesis of Cu/TiO{sub 2}/organo-attapulgite fiber nanocomposite and its photocatalytic activity for degradation of acetone in air

Energy Technology Data Exchange (ETDEWEB)

Zhang, Gaoke, E-mail: gkzhang@whut.edu.cn; Wang, He; Guo, Sheng; Wang, Junting; Liu, Jin

2016-01-30

Graphical abstract: - Highlights: • A novel Cu/TiO{sub 2}/organo-attapulgite fiber nanocomposite was synthesized successfully. • Micro-mesopore nanocomposite structure was in favor of the degradation of acetone. • CTAB modification improved the adsorption capability of the catalyst. • The photocatalytic degradation mechanism of the acetone by the catalyst was studied. - Abstract: The Cu/TiO{sub 2}/organo-attapulgite fiber (CTOA) nanocomposite was synthesized by a facile method and was used for photocatalytic degradation of acetone in air under UV light irradiation. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectrum (UV–vis DRS), inductively coupled plasma (ICP) spectrometry and N{sub 2} adsorption–desorption measurement. The results showed that the structure of organo-attapulgite (OAT) had no obvious change as compared to unmodified attapulgite (AT) and the attapulgite fibers in the OAT were well-dispersed. Both micropores and mesopores exist in the CTOA catalyst. The CTOA catalysts prepared at the Cu/TiO{sub 2} molar ratio of 0.003 shows an excellent photocatalytic activity for the degradation of acetone in air. The synergistic effect of Cu species and cetyltrimethylammonium bromide modification can be responsible for the enhanced photocatalytic activity of the CTOA catalyst. The mechanism of the photocatalytic degradation of acetone by the CTOA catalyst was discussed.

Butanol-acetone fermentation of sugar-cane juice

Energy Technology Data Exchange (ETDEWEB)

Perdomo, E V

1958-01-01

Sixteen new varieties of Clostridium acetobutylicum of varying activity were isolated from different sources. The most active one was obtained from sugar-cane roots. The effects of 86 additives were studied. The following formulation gave a 32% yield (with respect to sucrose) of solvent mixture (73% BuOH, 19 to 23% acetone, and 3 to 4% EtOH) sugar-cane juice (I) (20/sup 0/ Brix) 250 ml, ground Vicia sativa 1 g, KH/sub 2/PO/sub 4/ 2.5 g, CaCO/sub 3/ 4 g, H/sub 2/O 1000 ml; the pH of this solution was 5.6 to 6.0. Unclarified, it was inverted by invertase; the other components were added and the mixture was sterilized (20 minutes, 15 pounds).

Effect of adduct formation on valent state of cerium in its ν-diketonates

International Nuclear Information System (INIS)

Spitsyn, V.I.; Martynenko, L.I.; Pechurova, N.I.; Snezhko, N.I.; Murav'eva, I.A.; Anufrieva, S.I.

1982-01-01

Physicochemical investigation of the system cerium (III, IV)-ν-diketone-additional ligand shows that ν-diketonate ability to adduct formation decreases in the series tenoyltrifluoro-acetonate > acetylacetonate > dibenzoylmethanate > benzoylmethanate. Adduct formation of the cerium (III, IV) ν-diketonates stabilizes cerium in trivalent condition, while oxidation degree 4+ is stable in tetrakis-ν-diketonates. The additional ligands are arranged in the series: tributhylphosphate < trioctyl-phosphineoxide < triphenylphosphineoxide < α, α'-dipyridyl < o-phenanthroline by the effect on cerium (III) stabilization in its ν-diketonates

ON THE FORMATION OF INTERSTELLAR WATER ICE: CONSTRAINTS FROM A SEARCH FOR HYDROGEN PEROXIDE ICE IN MOLECULAR CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Smith, R. G.; Wright, C. M.; Robinson, G. [School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2600 (Australia); Charnley, S. B. [Astrochemistry Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Pendleton, Y. J. [NASA Lunar Science Institute, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Maldoni, M. M., E-mail: r.smith@adfa.edu.au, E-mail: c.wright@adfa.edu.au, E-mail: g.robinson@adfa.edu.au, E-mail: Steven.B.Charnley@nasa.gov, E-mail: yvonne.pendleton@nasa.gov [Geoscience Australia, Canberra, ACT 2601 (Australia)

2011-12-20

Recent surface chemistry experiments have shown that the hydrogenation of molecular oxygen on interstellar dust grains is a plausible formation mechanism, via hydrogen peroxide (H{sub 2}O{sub 2}), for the production of water (H{sub 2}O) ice mantles in the dense interstellar medium. Theoretical chemistry models also predict the formation of a significant abundance of H{sub 2}O{sub 2} ice in grain mantles by this route. At their upper limits, the predicted and experimental abundances are sufficiently high that H{sub 2}O{sub 2} should be detectable in molecular cloud ice spectra. To investigate this further, laboratory spectra have been obtained for H{sub 2}O{sub 2}/H{sub 2}O ice films between 2.5 and 200 {mu}m, from 10 to 180 K, containing 3%, 30%, and 97% H{sub 2}O{sub 2} ice. Integrated absorbances for all the absorption features in low-temperature H{sub 2}O{sub 2} ice have been derived from these spectra. For identifying H{sub 2}O{sub 2} ice, the key results are the presence of unique features near 3.5, 7.0, and 11.3 {mu}m. Comparing the laboratory spectra with the spectra of a group of 24 protostars and field stars, all of which have strong H{sub 2}O ice absorption bands, no absorption features are found that can definitely be identified with H{sub 2}O{sub 2} ice. In the absence of definite H{sub 2}O{sub 2} features, the H{sub 2}O{sub 2} abundance is constrained by its possible contribution to the weak absorption feature near 3.47 {mu}m found on the long-wavelength wing of the 3 {mu}m H{sub 2}O ice band. This gives an average upper limit for H{sub 2}O{sub 2}, as a percentage of H{sub 2}O, of 9% {+-} 4%. This is a strong constraint on parameters for surface chemistry experiments and dense cloud chemistry models.

Study of continuous acetone-butanol fermentation by Clostridium acetobutylicum

Energy Technology Data Exchange (ETDEWEB)

Yarovenko, V L; Nakhmanovich, B M; Shcheblykin, N P; Senkevich, V V

1960-01-01

Prophylactic sterilization of small scale equipment (2 fermenters, 3.5 cu. m. each) permitted continuous fermentation through 6 cycles (28 days), each with a new inoculum of C. acetobutylicum. Single cycles could be prolonged to 6 to 11 days without sterilization. Contamination, usually with lactic acid bacteria, sometimes preceded exhaustion of the culture. Input of flour mash at 0.6 to 1.2 cu. m./hr. and withdrawal of products were continuous; acetone yield 6.6 to 7.1 g./l.; residual sugars 0.63 to 0.79%.

The results of the lipids peroxidation products on the DNA bases as biological markers of the oxidative stress; Les adduits des produits de la peroxydation lipidique sur les bases de l'ADN comme biomarqueurs du stress oxydant

Energy Technology Data Exchange (ETDEWEB)

Falletti, O

2007-10-15

Different ways of DNA damages have been studied, among these ones the direct way of DNA damages formation by the reactive oxygen species (R.O.S.). This way leads to the formation of oxidative DNA damages. In 1990, works have suggested an indirect way of DNA damages formation, the lipids peroxidation. Instead of oxidizing directly DNA, the R.O.S. oxide the lipids present in the cells and their membranes; The products coming from this degradation are able to provoke DNA damages. This way has not been studied very much. The work of this thesis is axed on this DNA theme and lipids peroxidation. In the first chapter, we begin by presenting DNA and the direct way of oxidative damages formation by the R.O.S.Then, we speak about the cell lipids suffering oxidation reactions and the different ways of lipids oxidation. Then, we present how the lipid peroxidation is a source of damages for DNA. (N.C.)

Influence of hydrogen peroxide treatment on Au/n-ZnO contact

Energy Technology Data Exchange (ETDEWEB)

Chen, X.D.; Gu, Q.L.; Ling, C.C.; Djurisic, A.B. [Department of Physics, The University of Hong Kong, Pokfulam Road (China); Brauer, G.; Anwand, W.; Skorupa, W.; Reuther, H. [Institut fuer Ionenstrahlphysik und Materialforschung, Forschungszentrum Rossendorf, Postfach 510119, 01314 Dresden (Germany)

2007-07-01

The Au/n-ZnO contact behavior was investigated as a function of hydrogen peroxide pre-treatment of the ZnO sample by current-voltage (IV) measurement. The change from non-rectifying to rectifying performance upon etching was discussed in connection with sample characterization by positron annihilation spectroscopy (PAS), Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). It was concluded that the gain of the rectifying property was properly associated with the formation of a defective interfacial region at the Au/n-ZnO contact. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2D Sn-doped ZnO ultrathin nanosheet networks for enhanced acetone gas sensing application

KAUST Repository

Al-Hadeethi, Yas; Umar, Ahmad; Al-Heniti, Saleh. H.; Kumar, Rajesh; Kim, S.H.; Zhang, Xixiang; Raffah, Bahaaudin M.

2016-01-01

In this paper, we report the synthesis, characterizations and gas sensing application of 2D Sn-doped ZnO ultrathin nanosheet networks synthesized by a simple and facile hydrothermal process. The synthesized nanosheets were characterized using several techniques in terms of their morphological, structural, optical and compositional properties. The detailed characterizations confirmed that the nanosheets are pure, grown in high-density, possessing well-crystalline wurtzite hexagonal phase and exhibiting good optical properties. Further, the synthesized nanosheets were used as functional material to develop nanosensor device by coating it on the alumina substrate with suitable electrodes. The fabricated sensor device was tested towards acetone gas which exhibited a maximum sensitivity of 5.556 (Ra/Rg) for 200 ppm of acetone at 320 °C.

2D Sn-doped ZnO ultrathin nanosheet networks for enhanced acetone gas sensing application

KAUST Repository

Al-Hadeethi, Yas

2016-11-10

In this paper, we report the synthesis, characterizations and gas sensing application of 2D Sn-doped ZnO ultrathin nanosheet networks synthesized by a simple and facile hydrothermal process. The synthesized nanosheets were characterized using several techniques in terms of their morphological, structural, optical and compositional properties. The detailed characterizations confirmed that the nanosheets are pure, grown in high-density, possessing well-crystalline wurtzite hexagonal phase and exhibiting good optical properties. Further, the synthesized nanosheets were used as functional material to develop nanosensor device by coating it on the alumina substrate with suitable electrodes. The fabricated sensor device was tested towards acetone gas which exhibited a maximum sensitivity of 5.556 (Ra/Rg) for 200 ppm of acetone at 320 °C.

An Optimized Trichloroacetic Acid/Acetone Precipitation Method for Two-Dimensional Gel Electrophoresis Analysis of Qinchuan Cattle Longissimus Dorsi Muscle Containing High Proportion of Marbling.

Science.gov (United States)

Hao, Ruijie; Adoligbe, Camus; Jiang, Bijie; Zhao, Xianlin; Gui, Linsheng; Qu, Kaixing; Wu, Sen; Zan, Linsen

2015-01-01

Longissimus dorsi muscle (LD) proteomics provides a novel opportunity to reveal the molecular mechanism behind intramuscular fat deposition. Unfortunately, the vast amounts of lipids and nucleic acids in this tissue hampered LD proteomics analysis. Trichloroacetic acid (TCA)/acetone precipitation is a widely used method to remove contaminants from protein samples. However, the high speed centrifugation employed in this method produces hard precipitates, which restrict contaminant elimination and protein re-dissolution. To address the problem, the centrifugation precipitates were first grinded with a glass tissue grinder and then washed with 90% acetone (TCA/acetone-G-W) in the present study. According to our result, the treatment for solid precipitate facilitated non-protein contaminant removal and protein re-dissolution, ultimately improving two-dimensional gel electrophoresis (2-DE) analysis. Additionally, we also evaluated the effect of sample drying on 2-DE profile as well as protein yield. It was found that 30 min air-drying did not result in significant protein loss, but reduced horizontal streaking and smearing on 2-DE gel compared to 10 min. In summary, we developed an optimized TCA/acetone precipitation method for protein extraction of LD, in which the modifications improved the effectiveness of TCA/acetone method.

Ramalina capitata (Ach.) Nyl. acetone extract: HPLC analysis, genotoxicity, cholinesterase, antioxidant and antibacterial activity.

Science.gov (United States)

Zrnzevic, Ivana; Stankovic, Miroslava; Stankov Jovanovic, Vesna; Mitic, Violeta; Dordevic, Aleksandra; Zlatanovic, Ivana; Stojanovic, Gordana

2017-01-01

In the present investigation, effects of Ramalina capitata acetone extract on micronucleus distribution on human lymphocytes, on cholinesterase activity and antioxidant activity (by the CUPRAC method) were examined, for the first time as well as its HPLC profile. Additionally, total phenolic compounds (TPC), antioxidant properties (estimated via DPPH, ABTS and TRP assays) and antibacterial activity were determined. The predominant phenolic compounds in this extract were evernic, everninic and obtusatic acids. Acetone extract of R. capitata at concentration of 2 μg mL -1 decreased a frequency of micronuclei (MN) for 14.8 %. The extract reduces the concentration of DPPH and ABTS radicals for 21.2 and 36.1 % (respectively). Values for total reducing power (TRP) and cupric reducing capacity (CUPRAC) were 0.4624 ± 0.1064 μg ascorbic acid equivalents (AAE) per mg of dry extract, and 6.1176 ± 0.2964 μg Trolox equivalents (TE) per mg of dry extract, respectively. The total phenol content was 670.6376 ± 66.554 μg galic acid equivalents (GAE) per mg of dry extract. Tested extract at concentration of 2 mg mL -1 exhibited inhibition effect (5.2 %) on pooled human serum cholinesterase. The antimicrobial assay showed that acetone extract had inhibition effect towards Gram-positive strains. The results of manifested antioxidant activity, reducing the number of micronuclei in human lymphocytes, and antibacterial activity recommends R. capitata extract for further in vivo studies.

Direct synthesis of hydrogen peroxide in a microreactor

NARCIS (Netherlands)

Paunovic, V.; Schouten, J.C.; Nijhuis, T.A.

2014-01-01

The direct synthesis of hydrogen peroxide in a microreactor is a safe and efficient process. Conventionally, hydrogen peroxide is produced using the anthraquinone autooxidation process, which is rather complex and can only be performed cost-effectively on a large scale. As a result, hydrogen

Uranyl peroxide enhanced nuclear fuel corrosion in seawater.

Science.gov (United States)

Armstrong, Christopher R; Nyman, May; Shvareva, Tatiana; Sigmon, Ginger E; Burns, Peter C; Navrotsky, Alexandra

2012-02-07

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.

Raman study of pressure effects on frequencies and isotropic line shapes in liquid acetone

International Nuclear Information System (INIS)

Schindler, W.; Sharko, P.T.; Jonas, J.

1982-01-01

The Raman line shape of the symmetric C = O stretching band at 1710 cm -1 has been measured in liquid acetone as a function of pressure from 1 bar to 4 kbar over the temperature range from -25 to 50 0 C. The experimental data obtained show several unusual features. First, there is a frequency difference of about 7 cm -1 between the polarized and depolarized components. Sceond, the isotropic linewidth GAMMA/sub iso/ decreases with increasing density, in contrast to the opposite trend usually found in other liquids. Third, the second moment M 2 (V) of the isotropic band appears to decrease with increasing density. The consideration of the experimental linewidth and frequency data leads to a conclusion that intermolecular dipole--dipole coupling between polar acetone molecules are responsible for the observed unusual behavior of , GAMMA/sub iso/, and M 2

Physico Chemical Characteristic of Kappa Carrageenan Degraded Using Hydrogen Peroxide